Posted on 6/24/2010 03:20:00 PM
Medical Doctors often prescribe Paracetamol whenever their patients have fever. I often avoid reducing my body temperature if it is below 38.0 Degree Celsius. Honestly speaking, whenever we are sick, it is better to have fever. Does it sound like a myth to you? Am I kidding you? Are you surprise about what I had just said?
Pathogens (bacterias, viruses) and normal body temperature are usually optimized at 37.0 Degree Celsius. Similarly, if you are incubating a chicken egg, the temperature is also 37.0 Degree Celsius. If you are culturing an agar plate with e-coli bacterias, the required temperature is also 37.0 Degree Celsius. After looking at all these figures, I can conclude that most mammal live best at 37.0 Degree Celsius. This can also indirectly means that bacterias and viruses grow rapidly at 37 Degree Celsius. Taking Paracetamol reduces your body temperature to 37 Degree Celsius, thus enhancing the growth of bacterias and flu viruses.
When we have fever, our body temperature rises. The brain act as a thermostat to regulate the temperature according to how severe our condition is. The purpose of this evaluated body temperature is caused by the production of pyrogen to kill the pathogens. High fever slow down the enzyme in the bacteria, thus killing them. Viruses become inactive as our body temperature rises. Evaluated body temperature also speed up the body defense by enhancing the interaction of white blood cells with the pathogens.
By taking fever medicines, you are actually giving your body a slower chance to recover. When Paracetamol breaks down to its metabolite in the liver, preparing to be excreted from the body, this metabolite is toxic to our cells. You are only required to eat Paracetamol when your fever is above 38 Degree Celsius. This is because temperature from 39 Degree Celsius onward can cause brain damage due to the inability of the brain enzyme to work.
Doctors often advise us to eat 2 tablets (1000mg) of Paracetamol once every 6 hours. According to my own research and study, you only eat 1000mg of Paracetamol when you have high fever. If you have low to medium grade of fever, I would advise you to consume 1 tablet (500mg) of Paracetamol once every 4 hours. Firstly, the half life of the medicine and the conservative of drugs are more efficient. As you can see that the frequency of consuming the same quantity of drug is once every 6 hours (if you eat 2 tablets, 6 hourly) as compared to 8 hours (if you eat 2 tablets, 4 hourly). Secondly, your liver will have lesser stress to excrete the toxic metabolite of Paracetamol.
If you don't trust me that fever is beneficial rather than harmful, go ahead for a Google search. For your information, all the temperatures shown above are accurate only when you measure your temperature under the tongue.
Pls link:
http://www.ngweide.net/
Posted on 2/07/2010 10:46:00 AM
This is my (21.5 years old guy) ear frequency curve which you can use to compare with your hearing curve. x-axis represents decibel while y-axis represent frequency in log. Test your ear frequency now to check the quality of your hearing.
Download this
Excel file and this
sound frequency to do a test on your ear. Use a high quality ear piece which has a broad range of sound frequency so that you will not get a false result.
Firstly, open 3500Hz audio file and play it, adjust your ear piece until you can hear the 18th tone but not the 19th one, this is also known as calibration since different ear piece has different sound amplitude.
Secondly, open the Excel file. Play 40Hz and note which cut off level that you last heard and record the level in cell C3. Repeat this procedure for all others frequency audio files. Your frequency sensitivity curve will be generated on the right hand side graph, the lower the decibel, the better it is because it means your ear is sensitive to that frequency of sound.
How to read the log number? 10, 100, 1000 and 10000 are shown. Each minor axis from 10 to 100 represent 10 increment. Each minor axis from 100 to 1000 represent 1000 increment. Each minor axis from 1000 to 10000 represent 1000 increment.
Posted on 2/02/2010 06:29:00 AM
Many teenagers especially girls are very concerned about aging. As a result, this post is especially important for you. The purpose is to educate youngster some basic knowledge of maintaining their young and youthful appearance, longevity of life and staying with a healthy lifestyle. I will try to put this post as elucidating as possible so everybody who read can at least grab more than 50% of what I write; although some scientific terms seem to be hard to understand, I will try to explain each and every of the definition as much as possible. Let's start with some of the easy one.
Ionizing radiation - When we are talking about ionizing radiation in regards to staying young, we are talking about the ultraviolet radiation (UV ray) emitted from the sun which destroy our skin cells. Although X-ray is also an ionizing radiation, we are not talking about that since just one X-ray scan doesn't do you as much harm as the daily exposure to UV ray from the sun. Despite providing us with Vitamin D (a coenzyme important for the correct formation of our born and absorption of calcium), UV ray can also damage our cells DNA (causing cancer or sunburn), killing our cells (damaging factor), reducing the collagen in our face (more crevice formation that make us look older), causing free radical on our cells (free radical are high energy electron or ions that damage our cells such as destroying the DNA and this may cause benign or malignant tumors whereas malignant tumor is definitely a cancer). To stay young, it is advisable for you to put on sunscreen or lotion with zinc and antioxidant ingredient when you are exposing to the afternoon sunlight. Take note that UV ray can pass through some umbrella, the purpose of umbrellas are to shed visible light but not UV ray so do not assume that you are protected if you have an umbrella.
Antioxidant - As mention in the previous paragraph, what is antioxidant? Free radials are generated from your body during metabolism or when you are exposed to ionizing radiation. Free radials cause damages to the cell, sometime it can be so serious such that the cell becomes cancerous. The purpose of antioxidant is to neutralize the free radical so that there are lesser free radical in our body, thus lesser harms and therefore slower aging. To stay young, eat antioxidant such as lipoic acid, Vitamin C and E TOGETHER with many types of fruits and vegetables. You cannot totally depend on supplement as there are over 100 types of chemicals in fruits that work together to scavenge free radicals from your body.
Carbohydrate - Eating less carbohydrate can lead to longevity since glucose restriction means slower metabolism in our cells. When our cell metabolism slow down, lesser free radials are produced, thus, we will age slowly since there are lesser damages on our body. For some girls who are on high carbohydrate and fats restriction, because you are afraid that you may become fat even though you are underweight, you may have Anexoria nervosa. I have seen some of my teen friends who look normal weight as they restrict diet but have gastric problem after doing this for long term and they are still restricting carbohydrate. This is not the right way of doing since they will not get enough nutrient from food, thus slowing their growth rate during their puberty time. The right solution is to eat moderately, not too much such that it can gain you much fats or too little that can cause you gastric pain. Your existing health is your first priority but not spoiling one system for the purpose of losing weight. Strictly do not eat medical pills to slim down other than vitamins and minerals. Medical pills are harmful/cannot be trust, they can damage your livers and kidney for long term consumption. If half of your liver or kidneys are damaged, you wouldn't know since no symptoms will appear until 90% of it is damaged so you need to be careful.
Having enough sleep - Sleeping (not resting) is very important. While we are sleeping, our cell metabolism slow down, lesser free radials are produced. Therefore, people who sleep enough will look younger. When we are sleeping, our body undergoes a few cycle of random eyes movement, it is where our body becomes active, idle, active, idle, many repeating cycle for every few hours. This is the lay man term, in scientific terms, it is more than this but idle body does not happen when you are resting, except that when you are sleeping. Not only sleeping for a long time, a person must sleep at the right time; it means you sleep when you are sleepy but not sleeping too lately as it can affect your body clock. When your body is producing melatonin preparing for you to sleep, you force high production of Epinephrine while your body is producing melatonin at the same time. Does that make you feel actively drowsy; confused?
Posted on 12/24/2008 08:08:00 PM
Chew Chor Meng was diagnose with Kennedy's disease and I think most people know about this news. This disease causes muscle wasting and it means that he is going to have problem with motoring skills, weak muscle, muscle cramp and might lead to extreme disability. Kennedy's disease usually affect the boys but not the girls but girls are mostly the carrier.
Many people know that it is a disease but where does this disease come from? Why no cure? Our DNA is a blueprint of codes. In lay man terms, it is similar to computer operating system such as Window XP and Window Vista. However, human codes are more complicated, it is a book that tell our body how to produce protein, enzyme and antibodies or simply everything in the cells. DNA is made up of A, T, C and G, computer is made up of 0 and 1 while English is made up of A to Z.
From generation to generation, human genes will make error and when this error is passed down to another generation, they also get the error genes too. Gene errors are known as mutation and nobody can ever treat a mutated gene easily. There is a way but far to research; by planting a modified virus that is able to perform lysogenic cycle inside human body, it is able to remove the mutated gene with a new gene containing the right code. However, our body might recognise a good virus as a parasite so our immune system produces more antibodies to block the active site and thus grant it inactive. Therefore we have to find a way to inhibit these antibodies when undergoing this treatment.
Whether it is HIV, Cancer or Genes mutation, it can definitely be cured. HIV cannot be cured because people have not found out how to solve the complicated problem due to frequent mutation of the HIV genes. When HIV virus grow into its daughter virus, the daughter virus is somewhat different from the parent virus and this make it hard to specify one type of vaccine or antibody for the virus.
Chemotherapy and radiation therapy are often used to treat cancer but they have a lot of side effects. Scientist are now finding out on the antibodies that can recognise cancer cell and destroy it. HIV virus perhaps can be cured using molecular imprinting which is still at research by scientist. One virus that is particularly dangerous is Polio and this virus has been executed a few years back, it does not exist anymore.
Cancer can be prevented by reducing exposure to radiation, eat antioxidant such as Lipoic acid. Also eat more fruit as it contains many type of vitamins and anti-oxidant. At old age, human cells tend to have lesser efficiency repairing DNA, thus mutation is likely to be high.
Cancers are your cells that kill you. Bacteria infection is foreign living things that infect your body while virus is only a shell containing DNA, it is not a living thing yet it is able to kill you because it knows how to hack your cells.
Posted on 12/24/2008 10:43:00 AM
Many people are confused and do not know the difference between Antigens, Antibiotics and Antibodies. Antigens are foreign substances such as pollen grain that cause allergy or illness to human.
To block agains those antigens, the body produces antibodies to bind against the site of the antigens or a virus active site and therefore inactivate it. This virus is then brought down to the vacuoles which is digested or break down into waste.
Antibiotics have much simple molecule. It is used to kill the bacteria cells that infect us by inhibiting the bacteria from producing proteins such as enzyme. Some of the antibiotics even kill the cell membrane.
Molecular imprinting is something that can recognise a virus active site and bind onto it. A method that is particularly useful in removing the virus is through the use of filtration. This can lead to further study on how to cure HIV using this method.
The killer diseases are cancer and viruses. Until now, cancer still cannot be cured through a method with lesser side effects but virus still can be cured by the antibodies produced by our body. There is one method that is particularly useful in research field. This method uses an antibodies produced by mammalian cells which is able to recognise cancer cell. Once it capture the cancer cells, it is able to kill it and therefore all cancerous cells are killed. Research are still ongoing and one day scientist should find a cure for cancer.
HIV is harder to cure because it mutates very rapidly. People have found HIV inhibitors but it only allows HIV patients to live longer. It mitigates but does not cure. Therefore, scientist are finding other possible methods to cure HIV patients. For instance, molecular imprinting or maybe some antibodies that are able to recognise every type of mutated HIV viruses.
Posted on 11/22/2008 11:25:00 AM
Under most conditions, bacteria die without an intact cell wall. Since human cells completely lack a cell wall, this is an important target for antibiotics. To understand how these antibiotics work, though, it's necessary to understand how bacteria make cell walls. There are several steps in the process. Initially the "building blocks" (N-acetyl glucosamine and N-acetyl muramic acid) of the cell wall are made in the cytoplasm (the fluid that fills cells). These building blocks are then transported across the cell membrane using a carrier molecule, where they are next joined to an existing long chain of building blocks (in a process called transglycosylation) and are crosslinked to another long chain (in a process called transpeptidation). Bacteria make new cell wall material only when they are growing. Therefore, antibiotics that disrupt this process are typically only effective on growing cells.
Different antibiotics target different steps in cell-wall synthesis; for example, penicillin inhibits transpeptidation. Vancomycin inhibits transglycosylation and transpeptidation. Bacitracin inhibits the regeneration of the carrier required for moving the building blocks of the cell wall across the membrane.
Living and growing cells require a constant supply of new proteins. Without new proteins, a cell will either stop growing, or it may even die. In both bacterial and human cells, new proteins are manufactured on ribosomes, in a process called translation. However, bacterial ribosomes differ enough from human ribosomes that antibiotics can effectively target them.
Ribosomes require messenger RNA (mRNA), transfer RNA (tRNA), and amino acids (the building blocks of proteins) in order to make proteins. During translation, the ribosome slides along the mRNA in three-nucleotide steps; tRNAs bring in the appropriate amino acids to allow the protein to be made.
Streptomycin is an example of an antibiotic that targets the ribosome. This antibiotic binds to a ribosomal protein and interferes with the movement of the ribosome along the mRNA. As a consequence, streptomycin makes protein synthesis less accurate. Erythromycin is another example of an antibiotic that binds to ribosomal RNA. Erythromycin terminates protein synthesis prematurely, meaning that few, if any, functional proteins are produced by the cell. Tetracycline binds to the ribosome and interferes with a new tRNA (containing an amino acid) coming into the ribosome.
In order for a cell to divide, it must copy its DNA. An antibiotic that prevents DNA synthesis will therefore keep a bacterial population from growing, and may kill affected cells. Copying DNA in a cell is a complex process. The DNA synthesis machinery includes enzymes called DNA gyrase and topoisomerase, which help twist and untwist DNA during replication. These enzymes accomplish this feat by cutting the DNA, then "gluing" the cut ends back together. A similar process occurs in human cells, but the bacterial and human enzymes involved are different enough that some antibiotics can target the bacterial enzymes without affecting the human enzymes.
Ciprofloxacin and related antibiotics work by allowing topoisomerases to cut DNA but not "glue" the ends back together. The result is that the bacterium can no longer replicate its DNA, keeping the bacterial population in check. In addition, in some bacteria, this DNA damage may also activate a process that leads to the death of the bacterial cell.
Bacteria must continuously make RNA in order to survive. RNA plays many roles in the cell, including acting as a messenger between the information coded in the DNA and the protein-making ribosomes. RNA synthesis requires an enzyme called RNA polymerase, and this enzyme is critical in all types of cells. RNA polymerases differ enough between bacteria and human cells that the bacterial version can be targeted by some antibiotics. The antibiotic rifampin, for example, binds to bacterial RNA polymerase and prevents it from making RNA. Consequently, this leads to a loss of new protein synthesis. Since a continuous supply of new proteins is typically required for cellular survival, these antibiotics cause the death of the bacterial cell.
Folic acid is an essential vitamin that is required for many chemical reactions inside cells. Humans get folic acid from our diet; bacteria make their own from scratch. This difference helps explain why another group of antibiotics, the sulfonamides, are able to selectively kill bacteria. Sulfonamides work by mimicking the compound used by bacteria to make folic acid (para-amino benzoic acid or PABA). The sulfa drugs bind to an enzyme that is required to convert PABA to tetrahydrofolic acid and disable the enzyme so it can no longer function.
Sulfonamides are often given together with another antibiotic, trimethoprim, which inhibits a different stage of folic acid synthesis. In this case, the enzymes are found in both bacteria and humans, but the enzymes are different enough that trimethoprim binds to the bacterial enzyme with 60,000 times higher affinity (preference) for the bacterial versus human enzyme.6 The use of these two antibiotics provides double the assurance that the pathway will be disabled and reduces the likelihood of resistance developing.
A more restricted class of antibiotics, which work only on Mycobacterium tuberculosis and closely related bacteria, interfere with synthesis of components of the mycobacterial cell wall. One of these drugs, isoniazid, is an inactive chemical until it enters the bacterial cell. M. tuberculosis contains an enzyme that activates the antibiotic, which then goes on to damage enzymes that would otherwise assist in synthesizing the mycobacterial cell wall. Another drug, ethambutanol, inhibits the synthesis of a different component of the mycobacterial cell wall.
The presence of an intact membrane is critical for cellulars survival. The cell membrane acts as a barrier between the organism and the environment, preventing the loss of essential chemicals. Therefore, antibiotics that destroy membrane integrity should be very effective. Unfortunately, the membranes surrounding bacterial and human cells are quite similar, which is why antibiotics that target bacterial membranes also tend to harm human cells. Consequently, such antibiotics are typically restricted to use on the skin, the outer layer of which consists of dead cells that are unaffected by these antibiotics. Polymixin is an example of an antibiotic that disrupts cell membranes.
Posted on 11/22/2008 08:45:00 AM
Normal body cells divide and multiply a certain amount of time before the hormones and other body chemicals stop the division. Cancer is the name given to disease caused by abnormal cells multiplying out of control in the body as a result of mutation of the genes.
Cancer cells typically form a small lump of tissue, a tumour, which grow larger and larger uncontrollably. The cancer cell does not integrate well to the normal cells, as a result it can travel to other part of the body and continue to multiply, forming new tumours.
A growing tumour may press against various part of the body such as nerves and blood vessels or it may eat into them causing serious damage and consequently death. The most common type of caner in adults are lung cancer, prostate cancer, bowel cancer and breast cancer.
People in the middle or old age are most vulnerable to cancer. Two thirds of cancer cases occur in people who are over 65 years of age but children and young people sometimes also develop certain rare types of cancer.
Some cancers such as bowel cancer grow relatively slowly and do spread quickly. So there is a good chance that bowel cancer will not have spread if it is spotted early. By removing the tumour, the patient will be completely cure. Lung cancers grow rapidly and they are seldom caught at an early stage.
If you have a lump, gently move it to see if it stick together with the skin. If the characteristic of the lump is the same as our normal fresh, it should be a cancer cell. If you feel something hard or sharp inside, it is definitely not cancer.
Doctor usually test for cancer cell by telling a patient to drink a cup of water containing radioactive substance. The radioactive substance will travel to the cancerous cell, X-ray can detect it.
Brest cancer is most often detected as a small lump in the breast. Frequently it is found by woman herself but it may be picked up on an X-ray during mammography. Breast cancer is the most common form of cancer in women other than skin cancer. It is a devasting diagnosis for a woman but better treatment and earlier detection has lead to an improvement in the survival rate of women with breast cancer over the last 20 years.
Leukaemia is the most common cancer in childen but it also occurs in adults. It is a cancer of the white blood cells, which are made in the bone marrow in the centre of the bones. White blood cells are important for defending the body against infections but people with leukaemia have abnormally large numbers of white blood cells in their blood. They may be so many of them that they do not leave sufficient space for the red blood cells.
Treatment of leukaemia in children is generally very successful. About 75% of children now survive five or more years after the illness began. Treatment varies according to the type of leukaemia. Drugs are given to kill as many cancer cells as possible and induce a remission. After a short rest to give the patient time to recover, more drugs are given to rid the body of the last few cells. This may be followed by radiotherapy to kill Cancer cells that remain in the bone marrow. This treatment is sufficient to cure many patients. If the disease returns again, a bone marrow transplant may be possible if a suitable donor can be found.
After a transplant of the bone marrow, it takes at least 2 weeks for white blood cells to begin to be active again and much longer for the patients resistance to infection to return to normal. There is also a risk that the transplanted cells will fail to grow because they are rejected by the body. Therefore, it is important to select a person with best matching bone marrow before transplanting.
Posted on 11/15/2008 09:25:00 AM
Before we start, you got to understand all the vocabulary. DNA stands for Deoxyribonucleic acid. "Deoxyribo" refers to Deoxyribose which mean an oxygen is lost on the Ribose molecule so that the phosphate group can combine with Deoxyribose like a lego brick to form a long DNA. "Nucleic" refers to Nucleotides mainly the 4 bases (Adenosine, Thymine, Cytosine and Guanine). Adensosine (A), Thymine (T), Cytosine (C), Guanine (G) can be called ATCG in short.
DNA is a book while gene is the recipe in the book. DNA determine if you are a banana, human, monkey, rat or plant. Any modification to our DNA can change us from human to animals.
Computer language uses 0 and 1 to function. Human use A to Z to understand what people write. Javascript uses complicated scripts to enable it to function. While human DNA uses A, T, C and G as a language to build our body. In this world, if there is no languages, there will be no interaction.
Do you know that 98.5% of our DNA matches Chimpanzee? Chimpanzee was thought to be the closest species with us. Rhesus monkey has 93% of its DNA similar to human while between you and me, we are only 99.5% difference in our DNA. Yet, with such a good match, we look so differently. If I am 99.0% difference from you, I could be another species between Chimpanzee and human or a species which look entirely different.
Our body contains 50 trillion tiny cells and almost every one of them contains the complete set of instructions to make you. These instructions are encoded in your DNA and pack into the chromosome. Human have 23 pairs of chromosomes while Chimpanzee has 24 chromosomes.
Cells come in a dizzy array of types; there are brain cells and blood cells, skin cells and liver cells and bone cells. But every cells contains the same instructions in the form of DNA. So how do cells know whether to make an eye or a foot? The answer lies in intricate systems of genetic switches. Master genes turn other genes on and off, making sure that the right proteins are made at the right time in the right cells.To make new cells, an existing cell divides into two but before that, it has to copy its DNA so the new cells will each have a complete set of genetic instructions. Sometime, the cell can make mistakes during the copying process and this lead to diseases such as sickle blood cell.DNA is passed from parent to child. Main passed down its chromosome to his son while female passed down her mitochondria to her son and daughter.
Posted on 11/12/2008 09:10:00 PM
Human have 23 pair of chromosomes. Why are human chromosomes in pair? Chromosomes that pair one another are known as homologous. Homologous means that the chromosomes have the same length and their centromeres are in the same position, they show the same pattern of light and dark bands when stained, and they carry genes for the same inherited characteristics, line up on the chromosome in the same order.
Out of 23 pair of chromosomes, only male sex chromosomes are heterogeneous because they have chromosome XY while female has a matching pair which is XX. It is the Y chromosome that is of major interest to the genealogist because, as it is handed from father to son, virtually unchanged, it becomes a signature or fingerprint for the surname which is passed down in the same way in many cultures.
Now, you have learned something about human chromosomes but chromosome is not only the pieces that contain DNA. Now we are going to talk about Mitochondria which also contain DNA important for cell growth.
Mitochondria are extremely small, ranging from 0.002 to 0.008 millimeters in length whose details can only be seen with the electron microscope. Mitochondria are the power plant in our cell to generate energy for reaction and metabolism to take place. I give you an instance involving the job of Mitochondria in human cell. When you eat carbohydrate, it is broken down and finally converted to glucose. Mitochondria release the energy from glucose to power our cell.
Mitochondria contains small amount of DNA which is used to direct the manufacture of thirteen of the proteins needed for its activities. Mutations in the protein coding part of mitochondrial DNA can cause some human diseases, typically involving either neuromuscular dysfunction or some forms of diabetes.
Of interest to the genealogist (among others) is the fact that all of an individual’s mitochondria are derived from his/her mother. Although the sperm cell tail is packed with mitochondria to power its long journey to the egg cell, the tail and mitochondria drop off of the sperm at fertilization and never enter the egg cell. Consequently, all of the mitochondria in the fertilized egg come from an individual’s mother.
Each cell contains thousands of copies of mitochondrial DNA but only one paired set of chromosomal DNA.
Posted on 11/11/2008 07:22:00 AM
Polymerase Chain Reaction (PCR) is also known as Molecular Photocopying is used to make many copies of a small segments of DNA. It is a relatively inexpensive and fast method. Sometime, the quantity of DNA requires is not enough for doing a test, therefore it is necessary to duplicate more DNA to increase the accuracy and reliability of the result.
A particularly useful feature of PCR is that it allows the amplification process to be limited to specifically targeted segments of the DNA mixture such as the Y chromosome markers used in genealogical testing.
Your DNA can be simply taken from the cheek cells and send to the laboratory for testing. They will use detergent to cause the cells to burst open and release the DNA before washing it with a phosphate containing buffer solution to dilute cellular debris. The sample is now ready for the PCR to amplify.
PCR works because of DNA polymerase enzyme that can synthesize a complementary strand to a targeted segment of DNA in a test tube mixture of the 4 DNA bases. The mixture must also contain 2 DNA fragments, each about 20 bases long, called the primers. You will need to know the DNA sequence around the region you want to amplify before doing PCR. The primers can be purchased from commercial suppliers or can be constructed in the lab.
The mixture is first heated to denature or separate the sides of the double stranged DNA and then cooled to allow the primers to find and bind to their complementary sequences on the separated strands and the polymerase to extend the primers into new complementary strands. Repeated heating and cooling cycles multiply the target DNA exponentially, since each new double strand separates to become 2 templates for further synthesis. In about an hour, 20 PCR cycles can amplify the target by a million fold. In 32 cycles at 100% efficiency, 1.07 billion copies of targeted DNA region are created.
The entire cycle can be completed in just an hour with the use of thermocycler, programmed to change the temperature of the mixture every minutes so that the double strand will be denature and synthesis continously.
PCR is able to detect bacteria and virus DNA. Viruses such as HIV in very small quantity can be amplify in large quantity to read the DNA.
Posted on 11/02/2008 08:29:00 AM
A Mass Spectrometry is an equipment to help us identify the Mr of the compound and to identify the fingerprint of individual compounds. Each compound has different fingerprint. If you are to give a solution containing an unknown compound, I am able to find out what is the compound by using Mass Spectrometer. Look at the subsequent paragraph to understand what is parent and daughter ions. For your information, the post contains this word "Riboflavin". It is actually Vitamin B2.The parent ion is the precursor or the original compound that is ionized. The daughter is the product or the way that ions tend to fragment. Look at Figure 1, it shows Riboflavin molecule*, this is the parent ion or MS-1.
After the parent ion enters the collision chamber, it fragments into its daughter ion (MS-2) shown at Figure 2. If the ion fragments on the Nitrogen side, it will always fragment at the same point for the same molecule, this advantage gives the molecule an identity or a fingerprint.
If a compound has a molecular mass similar to Riboflavin, we cannot safely assume that it is Riboflavin. Thus we do MS-2 to collide the parent ion into daughter ions. Since different structures collide differently even though their molecular masses are the same, MS-2 will be able to show different fingerprint for two different compounds. We can further fragment the daughter ion (MS-2) into other daughter ions (MS-3) which could give a higher accuracy result.
*In the actual fact, it was an ion, for better illustration and ease of understanding, I used a non-ionized molecule instead.
While testing the standards, some compounds can produce more types of daughter ions. This is good because we can have more fingerprints. For instance, Riboflavin can produce many daughter ions and was able to continue fragmenting till MS-4. Compounds such as Linoleic acid could only produce a few daughter ions and limited to MS-2.
This was the difficulty when we were unable to get a reliable result for some compounds. However, by using the negative mode, it solved the problem and produced a better result.
Posted on 10/31/2008 06:18:00 AM
Fungi, animals and plants as well as unicellular organisums are Eukayotes. Eukayotic cells are 10 times larger than prokayotic cell and its volume can be 1000 times more than prokayotic cells.
Organelles are independent, distinct, memebrance-bounded structures within an eukaryotic cell which perform specific tasks for the overall success and well being of the cell. The physical features of the cell affect the specific functions of organelles. For instance, specialized digestive organelles called lysosomes perform the digestive functions in many Eukayotes. The absence of organelles greatly inhibited the prokayote's ability to evolve into more complex cells.
Within the cell, the nucleus is the most important blueprint. Much like a human brains, the nucleus represents the controller for the cell and includes 95% if urs DNA. Eukayotic cells require more complex DNA compared to prokayotic cells; it contains a great deal more DNA than prokayotes which usually contain only one circular molecule of DNA. Eukayotes' genome is structured into a number of linear chromosomes.
The endoplasmic reticulum extends away from the nuclear envelope through a network of tabules. This organelle performs complex tasks involved with synthesis of RNA into proteins, which are eventually extricated from the cell entirely or are distributed to specific places within the cell. Golgi apparatus which reside near the nucleus and endoplasmic reticulum. The golgi apparatus interfaces with a network of vesicles to transport contents to and from the golgi apparatus. As the contents pass through the organelle, any appropriate chemical alternations are performed. The contents may then be transported inside or outside the cell, as deemed necessary.
Mitochondria and chloroplasts make possible the energy transduction of their respective cells. Mitochondria metabolizes carbohydrates, fatty acids, and amino acidsinto oxidative energy required to sustain the eukaryotic cell. Chloroplasts use light energy to convert carbon dioxide and water into carbohydrates through a process known as photosynthesis. Chloroplasts are found primarily in algae and plants.
The cytoskeleton consists of a web or mesh of protein fibers that pervade throughout the cell forming the cell shape and support, managing intracellular traffic, and cell locomotion. The cell materials flow within paths defined by membrane walls and tabules, and traffic from one organelle to another is highly regulated. The three types of protein filaments found in the cytoskeleton include the actin filaments, microtubules, and intermediate filaments, all of which perform a variety of specific cell processes and functions.
The oldest known eukaryotic fossil is 1.5 billion years old, and evolution of prokaryotic cells preceded that of eukaryotic cells by 2 billion years. Eukaryotes reproduce on the basis of sexual reproduction as opposed to asexual, meaning genetic variations can be transferred to the cell's offspring. Since more genetic combinations were possible after the primitive Eukaryotes evolved, the evolution of multi-cellular animals became more plausible.
Posted on 10/28/2008 10:40:00 PM
Scientist have grown genetically engineered purple tomatoes in an unusual endeavour to promote healthy food. The tomatoes have two genes taken from the snapdragon flower to enable them to express a compound called anthocyanin (the chemical that I used to make pH indicator), the purple pigment found in high levels in fruit such as black berries and cranberries.
Previous research has found that anthocyanins offer protection against certain cancers, cardiovascular and degenerative diseases and may also hinder inflammation, obesity and diabetes. The study published online on Sunday by Nature Biotechnology, a journal of the London-Based Nature Publishing Group.
Researcher Cathie Martin from the John Innes Centre, a biotechnology institute in Norwich, eastern England, said the point behind the purple tomatoes was to boost the healthiness of diets. Most people do not eat five portions of fruit and vegetables a day, but they can get more benefit from those that they do eat if common fruit and vegetables that are higher in bioactive compounds can be developed.
After creating the purple tomatoes in the lab, the team tested the products on mice that they had engineered to be susceptible to cancer. Mice fed with the high anthocyanin tomatoes showed a significant extension of life span.
Posted on 7/31/2008 04:28:00 PM
What exactly does pH mean? pH is the short form for potential hydrogen. The pH of any solution is the measure of its hydrogen-ion concentration. The higher the pH reading, the more alkaline and oxygen rich the fluid is. The lower the pH reading, the more acidic and oxygen deprived the fluid is. The pH ranges from 0 to 14, with 7.0 being neutral. Indicator above 7.0 is alkaline and below 7.0 is considered acidic.
Our blood pH has a very narrow range of around 7.35 to 7.45. If our body's pH deviates from this range, we will be sick or have symptoms of falling sick. If our blood pH falls below 6.8 or above 7.8, our body cells will stop functioning and death will occur.
A normal healthy body will have an almost equal blood pH of acidity and alkalinity. The most ideal pH balance is 7.4 , which means that it is slightly more alkaline than acid. Only when the pH level is balance that our bodies can then effectively assimilate vitamins, minerals and food supplements. As such, our body pH's determines everything.
An acid pH body is more prone to illness. In an acidic environment, red blood cells cannot repel and stick together like a stack of coins, forming what is called rouleau formation. This formation limits the amount of oxygen carrying capacity because red blood cells sandwiched between the two ends are compressed against each other and therefore unable to carry oxygen. Reduced oxygen leads fatigue, lack of energy, and weakness, just to mention a few symptoms. Furthermore, cancer cells strives in an oxygen deprived environment (anaerobic) much better than in an oxygen rich environment.
The importance of maintaining optimum pH is therefore a critical factor in balancing proper internal terrain to deter cancer, infection, and a host of inflammatory disease. The majority of these conditions worsen in an acidic environment. They do not do well in an acidic environment.
What then happens when the body is too acidic? An acidic balance will:
1. Decrease the body's ability to absorb minerals and other nutrients
2. Decrease energy production in the cells
3. Decrease the body's ability to repair damaged cells
4. Decrease the body's ability to detoxify heavy metals
5. Enable tumor cells to thrive
6. Make the body more susceptible to fatigue and illness.
Some people who have high acidity levels tend to exhibit these symptoms such as: anxiety, diarrhea, dilated pupils, extroverted behavior, fatigue in early morning, headaches, hyperactivity, hyper sexuality, insomnia, nervousness, rapid heartbeat, restless legs, shortness of breath, strong appetite, high blood pressure, warm dry hands and feet.
Most of the time, the body becomes acidic due to a diet rich in acids, emotional stress, toxic overload, and/or immune reactions or any process that deprives the cells of oxygen and other nutrients. When this happens, the body will try to compensate for acidic pH by using alkaline minerals such as calcium. As a result, calcium is removed from the bones, causing osteoporosis.
Acidosis, which is an extended time in the acid pH state, can result in rheumatoid arthritis, diabetes, lupus, tuberculosis, osteoporosis, high blood pressure and most cancers.
Two main factors leading to cancer are an acidic pH and a lack of oxygen. As such, are we able to manipulate these two factors so as to prevent and control cancer?
Everyone knows that cancer needs an acidic and low oxygen environment to survive and flourish. Research has proven that terminal cancer patients have an acidity level of 1,000 times more than normal healthy people. The vast majority of terminal cancer patients have a very acidic pH. Why is this so?
The reason is simple. Without oxygen, glucose undergoing fermentation becomes lactic acid. This causes the pH of the cell to drop to 7.0. In more advance cancer cases, the pH level falls further to 6.5. Sometimes, the level can even fall to 6.0 and 5.7 or lower. The basic truth is that our bodies simply cannot fight diseases if our pH is not properly balanced.
The normal human cell is slightly alkaline and has an abundance of molecular oxygen. The cancer cell is acidic and cannot survive in an oxygen rich environment. As such, we can conclude that pH balance is very important to one's health, especially for the cancer patient.
The pH indicators are an exponent number of 10. A small difference in pH will translate to a big difference in the number of oxygen or OH-ions. A difference of 1 in a pH value means ten times the difference in the number of OH-ions. A difference of 2 means one hundred times the difference in the number of OH-ions. In other words, a blood with a pH value of 7.45 contains 64.9% more oxygen than blood with a pH value of 7.30.
1. Salivary pH Test
Just wet a piece of litmus paper with your saliva 2 hours after a meal and this will give you a reflection of your state of health.
Although saliva is generally more acidic than blood, it is a fairly good indicator of health. It tells you what your body retains. Salivary pH is a fair indicator of health for extracellular fluids and their alkaline mineral reserves.
The optimal pH for saliva is between 6.4 to 6.8. A reading lower than 6.4 means that there is not enough alkaline reserves. After meals, the saliva pH should rise to 7.8 or higher. If there is no increase, it will imply that the body has a deficiency in alkaline minerals especially calcium and magnesium. Food will not be absorbed and assimilated well. To deviate from an ideal salivary pH for an extended time will lead to illnesses.
If the salivary pH level remains too low, we should take more fruits, vegetables and mineral water and avoid strong acidifiers such as sodas, whole wheat and red meat to maintain its balance.
2. Urinary pH Test
The pH of the urine is an indication as to how well the body is working to maintain a proper pH of the blood. It reflects the efforts of the body via the kidneys, adrenals, lungs and gonads through the buffer salts and hormones. The urine also shows the alkaline building (anabolic) and acid tearing down (catabolic) cycles. By taking urine samples, we can have assess to a fairly accurate picture of our body chemistry as our kidneys filter out the buffer salts of pH regulation and provide values based on what the body is eliminating. The urine pH can vary from around 4.5 to 9.0, but the ideal range is still 5.8 to 6.8.
To increase the alkalinity in our blood, we can consume these foods: almonds, aloe vera, apples, apricots, bee pollen, buckwheat, cabbage, cantaloupe, celery, carrots, cucumbers, dairy products except hard cheese, dates, pulse, poached eggs, figs, grapefruit, honey, lettuce, millet, parsley, raisins, peaches, fresh red potatoes, pineapple, soy products, sprouted seeds, cooked spinach, turnip tops, wakame miso soup, azuki beans, rice and mineral water.
In conclusion, balancing your pH is a major step towards optimal well-being and better health. Acidosis is the main cause of calcium deficiency disease. After many studies, scientists can safely conclude that healthy people have body fluids that are alkaline (high pH) whereas sick people have body fluids that are acidic (low pH).
Posted on 7/31/2008 02:59:00 PM
This is the experiment I have tried today and it was quite successful. These are the chemical I can found in my kitchen --> Sodium Bicarbonate, Sodium Chloride, Acetic Acid.
I want to make Hypochlorous Acid but this acid is very difficult to get a pure state so I made impure. Firstly, take a pail of water and add as much Sodium Chloride as possible until it can no longer dissolve so you can get a faster result. Then connect the positive of the car battery to a Carbon rod and the negative to another Carbon rod. We use Carbon (Graphite) because it does not decompose in electrolysis. (IMPORTANT: Make sure that the 2 Carbon rods are not connected together as this short circuit can be hazardous, the car battery is capable of producing 30 Ampere of current if you don't realise how powerful it is).
Now, add a membranes (paper) at the middle of this 2 electrode. Make sure that the water from the left side does not drift to the right side if not the experiment will be a real failure. After this step, put in the electrode and the electrolysis start. If you put more salt, you will have to do the electrolysis longer to eliminate the Sodium Chloride.
After the experiment, scoop an equal amount of liquid from the right hand side of the membrane and the left hand side membrane without causing any disturbance to the water. Pour the right hand side solution into the right hand side container and left hand side solution to the left hand side container. At the positive electrode, it absorb oxygen and chlorine gas. Chlorine react with water to form Hydrochloride Acid and Hypochlorous Acid (Weak Acid Bleach). Great, you have done with making a mixture of Hypochlorous Acid Solution.
If you want to make Hydrochloride Acid, put the Hypochlorous mixture under strong sunlight and now the Hydrochloride Acid is produced with some oxygen gas but exit to the environment.
The other side of the electrode produce Sodium Hydroxide which can be used in many chemical reaction or react it with acid to form Sodium Chloride.
What happen if there is no membrane in your electrolysis. You will obtain NaOCl (Alkaline Bleach) or NaOCl3 if temperature is more than 40 Degree Celsius. Using a Cabbage pH indicator, we can prove all this chemical are correctly produced.
We can also make Sodium Carbonate by heating Sodium Bicarbonate. Further heating to about 1000 Degree Celsius will get us Sodium Oxide. We can also make Sodium Acetate or in IUPAC it is called Sodium Ethanoate.
Posted on 7/31/2008 10:38:00 AM
Just like how people damage their skin in the sun, products can also get nasty burns. That's why farmers are increasing applying sunscreen to their crops to prevent skin blistering, heat stress and blemishes.
Sunspots on a Granny Smitch apple can mean the difference between the lowest pricefor juice or the more lucractive fresh fruit market.
As for nuts, buyers last year paid on average 3 cents per 500g more for sunscreen protected nuts than untreated one. With yields topping more than 900kg per 4000 square metres, it add ups.
Climate change and drought in Australia and California's Central valley have meant challenging growing conditions for farmers that are affecting the quality, yields and price of the product.
Sunscreens alleviate at least one worry for farmers who lose money for each druit or vegatble that develps sun damage. Plants react to sun stress like humans. They perspire, a process called transpiration which means the more temperatures rise, the more water they need.
As drought grips several of the world's key growing regions, scientists are looking at ways to conserve by helping plants use less.
Liquuified clay has been used for many years but a California company is finding positive results with an SPF 45 product made of multi-crystaline Calcium Carbonate crystals that are engineered to specifically deflect ultraviolet and infrared light from the plants and trees on which it is sprayed.
The product keeps out the bad light, but lets in the good photosynthesis rays that air ripening. It has been tested in Australia and Chile, where UV rays affect production, and is in the second year of field tests in California.
Tests show that its immediate impact is increasing yields by diminishing stress and heat related defects. It also can play a role in water and energy conservation by increasing a plant's water efficiency.
Posted on 7/31/2008 07:41:00 AM
This few days, I was thinking of the experiments that can be done during this Saturday Mentoring Club session. It has took me quite a long time, many experiments could be possible but just without the appropriate equipment or just one of it, the experiment could not be implemented.
Yesterday, I was exploring how to make a liquid chromatography using the 6 colours in M&M and my column is about 15cm but just that I was unable to select an appropriate stationary and mobile phase. My stationary phase was plastic powder that is very fine but the problem is that I could not compress the powder to a higher bulk density to allow more interaction between the stationary phrase and the sample. I also fail to select the correct mobile phrase. Paper chromatography also fail to work so I gave up on trying, maybe should try that after I have the appropriate equipment and a good understanding in its theory.
The next thing I tried was to make pH indicator and this trial was successful. What type of plants change its colour when the pH of the soil change? Some plants such as cherries. red cabbage, some flowers such as rose, blueberries and beet root can be used to make pH indicators. I use red cabbage because it is cheap, have higher resolution and easier to extract its pigment. Firstly, I pour 100 Centigrade of water into the red cabbages before I blend it inside the mixture to cut it into juice and pour into a container, add some salt and you are done with it. Salt to preserve the pH indicator.
The left side is Blench, then the second right is Sodium Hydrogen Carbonate, The second left is pure water and the right hand side is Acetic Acid (Vinegar). I am going to buy Vitamin C (Absorbic acid) later to see how is the result.
Posted on 7/29/2008 10:42:00 PM
There are many types of Biosafety Cabinet. Class I, Class IIA, Class IIB1, Class IIB2, Class IIB3 and Class III.
Class I BSC allow air to pass into the cabinet without passing it through HEPA filter and this tell us that it does not provide protection against the product. The exhaust is equipped with a HEPA filter so that the air will be free from contaminant before it is allowed to exit into the environment. Thus, it has a good protection to the laboratory personnel and the environment. The air flow rate of Class I BSC is about 75fpm. It is often used to enclosed equipment such as fermenter or any process that produce a lot of aerosol.
Class IIA biosafety cabinet has a front and back grille. The air is drawn into the HEPA filter from the front grille and 70% of the filtered air is introduced from the top of the BSC and the remaining 30% is goes to the exhaust. This provide protection to the product, personel and the environment. The air flow rate is 75fpm.
Class IIB1 biosafety cabinet has an air flow of 100fpm and there are front and back grilles. About 70% of the air is drawn from the back grille and 30% from the front grille so when you want to work with chemical that is cacinogens, it is recommended for you to do at the rear grille due to the high air change at that particular area. This system has a 30% air circulated into the cabinet while 70% exit to the exhaust.
Class IIB2 biosafety cabinet has a 100% air exhausted. The air will first enter the HEPA filter before it is introduced into the cabinet so it protect the products. The air is also filtered after it has been passed the cabinet so that it protects the environment. The front grille suck the air inward so it protects against the laborartory personnel.
Class IIB3 is the same as Class IIB2 but it has a negative pressure that protect the cabinet so that if there is any leaks, there will be no chance for it to enter the environment. The negative pressure front grille make sure that the air enter the BSC but not exit into the environment. It has a positive pressure contaminated plenums within the cabinet are surrounded by a negative air pressure planum so leakage in a contaminated plenumwill be into the cabinet and not into the environment.
Class III is the glove box and it is a closed system to be used in BSL-4 virus. It has a very good protection and have 100fpm air velocity. The outlet is equipped with 2 layers of HEPA filter for better air filtration. It is a gas tight contruction with non opening view window. It provides a maximum protection to personnel and the environment.
Posted on 7/29/2008 10:30:00 PM
There are 4 biosafety level. Biosafty Level 1 to 4. Biosafety level 1 is suitable for works involving chracterized agents which does not cause any human diseases and minimal hazard to the laboratory personnel and environment.
Biosafety level 2 is suitable for works involving moderate agent which cause moderate hazard to the laboratory personnel and environment.
Biosafety level 3 is suitable for works involving dangerous agent whcih has potential hazard that can be easily spread by air and can cause high risk to laboratory personnel and environment.
Biosafety level 4 is suitable for works involving exotic and dangerous agent that pose high individual risk when exposed to the aerosol and this it causes life threatening diseases and infection is potentially hazard. An example is Ebola Zaire, once infected with it, 90% of the infected patient will be killed in 7 days and the high mortality rate plus the easy of spreading from individual to individual increase the risk level.
Posted on 7/29/2008 10:27:00 AM
Nobody has ever realized what make you fat or skinny. People often say when you eat more, you will gain but the fact is not 100% true, there is an optimization point. Many things contribute and decide your weight and body mass index.
Why some peoples are fatter? Often people say "eating more means fat" but the fact is that eat lesser will get fatter. The word "less" means that you eat lunch and dinner but skip breakfast, tea break, supper and as a result, your digestive enzymes are enough to completely digest the food you eat, thus resulting in 95% absorption.
If you eat a lot of meal but a little at a time, you will also get fatter and the same theory lies in that your digestive enzyme is enough and now it becomes 90% nutrient absorption into your blood stream. If you overeat, you will have moderate weight and will never get fat as the enzyme in your stomach is not enough to digest your food and sometime it is slow enough such that your next meal is here but the food in your stomach is still not yet digested, this tell us why skinny people who eat a lot doesn't get fat.
If you are skinny and wish to gain weight and when you eat a lot and does not find a significant changes in gaining weight, you must not overeat but to eat more meals per day. After you had your lunch or dinner, eat a tablet of digestive enzyme purchase from GNC or a slice of pineapple to help your body digest well. A good digestion will ensure no wastage and a good absorption of food.
For female especially who want to loss weight, it is not all about eating more that will cause you to gain weight, I guess this should only contribute 30% of not getting fatter. Exercise more, eat more, stress more, sleep 8 hours but not 12 hours a day, at least have a bit of muscle as it is the thing that consume the most energy in your body. Whenever you eat, EAT MOST but not eat more and do you know that your stomach consume 80% of your body working wattage when your stomach digest food? So eat more but it does not means eating unhealthy and oily food. The word "eating more" means eating in a healthy way by following the quantity in the food pyramid.
When a person get older, their metabolism rate decreases, they start to think slowly, walk slowly or becoming more lazy and this group of people must keep themselves active because it will directly affect their weight.
Some people say that exercising does not slim them down but if you know how your body work, you will get what you want. Do you know that if you jog for 10 minutes or exercise for 1 hour, it is not going to loss you much energy and this is equal to waking up 2 hours earlier every morning. If you want to slim down, you have to keep yourselves active from morning to night such as doing housework, thinking a lot, walking for 2 hours, writing blog instead of watching television and make sure you don't fall asleep on the day.
Let's take an example so you will get what I mean. Doing nothing will waste 200 watt of energy from you body. Jogging will use 500 watt of energy and if you jog for 10 minutes, it will eat up 300kJ of energy. If you keep yourselves active for the day, you will use up 300 watt of energy in average rather than 200 watt so usually a day is 16 hours and you will use up 5760kJ of energy more. It means by staying active for 16 hours is equal to jogging for 3 hours a day. Consequently, exercise is not a good thing to lose weight.
Posted on 7/27/2008 10:44:00 PM
Now I have $39.21, do you think I can earn $10.79 from Nuffnang this week if I have an average of 50 visitors per day from the Samsung advertisement display above from 27 July to 2 July?If not how many unique visitors do I need before I earn $10.79 this week for cash out?
Posted on 7/15/2008 10:36:00 AM
Vitamin A is a fat-soluble vitamin with four major functions in the body: It helps cells reproduce normally—a process called differentiation (cells that have not properly differentiated are more likely to undergo pre-cancerous changes). It is required for vision; vitamin A maintains healthy cells in various structures of the eye and is required for the transduction of light into nerve signals in the retina. It is required for normal growth and development of the embryo and fetus, influencing genes that determine the sequential development of organs in embryonic development. It may be required for normal reproductive function, with influences on the function and development of sperm, ovaries and placenta.
Liver, dairy products, and cod liver oil are good sources of vitamin A. Vitamin A is also available in supplement form.
People who limit their consumption of liver, dairy foods, and beta-carotene-containing vegetables can develop a vitamin A deficiency. Extremely low birth weight babies (2.2 pounds or less) are at high risk of being born with a deficiency, and vitamin A shots given to these infants have been reported in double-blind research to reduce the risk of lung disease. The earliest deficiency sign is poor night vision. Deficiency symptoms can also include dry skin, increased risk of infections, and metaplasia (a precancerous condition). Severe deficiencies causing blindness are extremely rare in Western societies.
Less severe deficiencies are more likely to occur with a variety of conditions causing malabsorption. A high incidence of vitamin A deficiency in people infected with HIV has also been reported. People with hypothyroidism have an impaired ability to convert beta-carotene to vitamin A. For this reason, some doctors suggest taking supplemental vitamin A (perhaps 5,000–10,000 IU per day) if they are not consuming adequate amounts in their diet.
Very old people with type 2 diabetes have shown a significant age-related decline in blood levels of vitamin A, irrespective of their dietary intake.
For most people, up to 25,000 IU (7,500 mcg) of vitamin A per day is considered safe. However, people over age 65 and those with liver disease should probably not supplement with more than 15,000 IU per day, unless supervised by a doctor. In women who could become pregnant, the maximum safe intake is being re-evaluated. However, less than 10,000 IU (3,000 mcg) per day is generally accepted as safe. There is concern that larger intakes could cause birth defects. Whether the average person would benefit from vitamin A supplementation remains unclear.
Since a 1995 report from the New England Journal of Medicine, women who are or could become pregnant have been told by doctors to take less than 10,000 IU (3,000 mcg) per day of vitamin A to avoid the risk of birth defect. A recent report studied several hundred women exposed to 10,000–300,000 IU (median exposure of 50,000 IU) per day. Three major malformations occurred in this study, but all could have happened in the absence of vitamin A supplementation. Surprisingly, no congenital malformations happened in any of the 120 infants exposed to maternal intakes of vitamin A that exceeded 50,000 IU per day. In fact, the high-exposure group had a 50% decreased risk for malformations compared with infants not exposed to vitamin A. The authors noted that some previous studies found no link between vitamin A and birth defects, and argued the studies that did find such a link suffered from various weaknesses. A closer look at the recent study reveals a 32% higher than expected risk of birth defects in infants exposed to 10,000–40,000 IU of vitamin A per day, but paradoxically a 37% decreased risk for those exposed to even higher levels. This suggests that both “higher” and “lower” risks may have been due to chance.
Excessive dietary intake of vitamin A has been associated with birth defects in humans in fewer than 20 reported cases over the past 30 years. Presently, the level at which vitamin A supplementation may cause birth defects is not known, though combined human and animal data suggest that 30,000 IU per day should be considered safe. Women who are or who could become pregnant should consult with a doctor before supplementing with more than 10,000 IU per day.
Vitamin A supplements can both help and hurt children. Many people have heard that vitamin A supplements support immune function and prevent infections. This is true under some circumstances. However, vitamin A can also increase the risk of infections, according to the findings of a double-blind trial. In a study of African children between six months and five years old, a 44% reduction in the risk of severe diarrhea was seen in those children given four 100,000–200,000 IU applications of vitamin A (the lower amount for those less than a year old) during an eight-month period. On further investigation, the researchers discovered that the reduction in diarrhea occurred only in children who were very malnourished. For children who were not starving, vitamin A supplementation actually increased the risk of diarrhea compared with the placebo group. The vitamin A-supplemented children also had a 67% increased risk of coughing and rapid breathing, signs of further lung infection, although this problem did not appear in children infected with AIDS. These findings should be of concern to American parents, whose children are not usually infected with AIDS or severely malnourished. Such relatively healthy children fared poorly in the African trial in terms of both the risk of diarrhea and the risk of continued lung problems. Vitamin A provided no benefit to the well-nourished kids.
Therefore, it makes sense to not give vitamin A supplements to children unless there is a special reason to do so, such as the presence of a condition causing malabsorption (e.g., celiac disease).
In a study of people with retinitis pigmentosa (a degenerative condition of the eye), participants received 15,000 IU of vitamin A per day for 12 years with no signs of adverse effects or toxicity. For other adults, intake above 25,000 IU (7,500 mcg) per day can—in rare cases—cause headaches, dry skin, hair loss, fatigue, bone problems, and liver damage. At higher levels (for example 100,000 IU per day) these problems become more common.
A controlled clinical trial showed that people who took 25,000 IU of vitamin A per day for a median of 3.8 years had an 11% increase in triglycerides, a 3% increase in total cholesterol and a 1% decrease in HDL cholesterol compared to those who did not take vitamin A. Although the significance of these findings is not clear, people at risk for cardiovascular disease should use caution when considering long-term vitamin A supplementation.
One study found that increasing the intake of vitamin A in the diet was associated with bone loss and risk of hip fracture, possibly due to a vitamin A-induced stimulation of cells that break down bone. In this study, a vitamin A intake greater than 5,000 IU per day, when compared to a lower intake, was associated with a reduction in bone mineral density that approximately doubles the risk of hip fracture. Beta-carotene (which can be used by the body to make vitamin A) has not been linked to reduced bone mass. Until more is known, people concerned about osteoporosis may consider taking beta-carotene supplements rather than supplementing with vitamin A.
Data from test tube, animal, and human studies show that excessive vitamin A intake can accelerate bone loss and inhibit formation of new bone, increasing the risk of osteoporosis. In humans, small studies have found these effects at about 85,000–125,000 IU per day.
Taking vitamin A and iron together helps overcome iron deficiency more effectively than iron supplementation alone. Supplementation with zinc, iron, or the combination has been found to improve vitamin A status among children at high risk for deficiency of the three nutrients.
Posted on 7/06/2008 11:47:00 AM
Forming in the fermenter is usually caused by the usage of protein such as corn steep liquor. Foaming can cause removal of cells by autolysis and further realease of microbial cell proteins will probably increase stability of form.
Problems with foaming -> Reduction in working volume fermenter due to oxygen exhuausted gas bubbles circulating in system. Low mass and heat transfer rate. Invalid process data due to interference at sensing electrodes and incorrect monitoring and control. Biological problems include deposition of cells in upper parts of the fermenter. Problems of sterlise operation with air exit filters of fermenters become wet.
An ideal anti-forming method must be used so as to increase the yield and to make sure that the cell consume the food in the tank but not the anti-forming agent. Ideal antiform should disperse readily and have fast action on existing form, should be active at low concentration, should be long acting in preventing new form formation, should not be metabolized by the microorganism, should not be toxic to microorganism, human, animals, birds and the environment, should not cause any problems in product extraction and purification, should not cause any handling hazards, should be cheap and readily available, should have no effect on oxygen transfer, should be heat sterilisable.
Examples of antiforming agents are alcohols, esters, fatty acids and derivatives, silicones, sulphonates and polypropylene glycol.
Posted on 7/06/2008 11:43:00 AM
Before we start a large scale batch fermentation, we usually build our size from a small shaking flask before we transfer the cell into the large fermenter.
Here is the inoculum requirements -> It must be healthy, active and this tell a short lag phase in the fermentation process. It must be available in large and sufficient amount to provide inoculum of optimium size. It must be in a suitable morphological form. It must be free from contamination. It must retain its product formaing capabilities.
Posted on 6/05/2008 06:09:00 PM
Clean In Place is often use in chemical plant to clean vessel and is usually use to clean the without the need to do manual cleaning.
Posted on 5/19/2008 09:37:00 AM
Theodor Escherich first described E. coli in 1885, as Bacterium coli commune, which he isolated from the feces of newborns. It was later renamed Escherichia coli, and for many years the bacterium was simply considered to be a commensal organism of the large intestine. It was not until 1935 that a strain of E. coli was shown to be the cause of an outbreak of diarrhea among infants.
E. coli and its relatives are known to microbiologists as "enteric bacteria", because they live in the intestinal tract of humans and other animals. The best known other enteric bacteria are Salmonella, which includes the agent of typhoid fever, and Shigella, which is the bacterial cause of dysentery.
E. coli is in the bacterial family Enterobacteriaceae, which is made up of Gram-negative, nonsporeforming, rod-shaped bacteria that are often motile by means of flagella. The majority of strains grow well on the usual laboratory media in both the presence and absence of oxygen, and metabolism can be either by respiration or fermentation.
For most of the 20th century, E. coli has been used as the principal indicator of fecal pollution in both tropical and temperate countries. E. coli comprises about 1% of the total fecal bacterial flora of humans and most warm-blooded animals. Sewage is always likely to contain E. coli in relatively large numbers. In addition, E. coli, being a typical member enteric bacterium is presumed to have survival characteristics very similar to those of the well-known pathogens such as Salmonella and Shigella. Thus, E. coli has been used world-wide as an indicator of fecal microbiological contamination. As such an indicator organism, its value is significantly enhanced by the ease with which it can be detected. and cultured.
Tests to identify isolates as E. coli have, of necessity, been simple tests designed predominantly to differentiate them from organisms normally associated with uncontaminated water. Since full biochemical analyses are not generally performed, the term "coliform" has been coined to describe E. coli-like organisms that satisfy these limited tests. As a result, regulations are promulgated throughout the world defining standards for water based on the so-called "coliform count." For example, in the U.S., according to a regulation published in the Federal Register (1986), there is a requirement that there be 0 coliforms/100 ml drinking water, as determined by any method for any sampling frequency.
Since not all organisms which meet the criteria of a coliform are associated with the intestinal tract (some may be free-living), a further distinction must be made between "fecal coliforms" (E. coli) and "nonfecal coliforms" (e.g. Klebsiella and Enterobacter). The nonfecal coliforms are regularly found in soil and water and in associations with plants, so that their occurence does not necessarily indicate fecal pollution.
In order to distinguish E. coli from related species likely to be found naturally in the environment, a battery of tests called the IMViC reactions was developed in order to differentiate fecal coliforms from nonfecal coliforms. IMViC is an acronym in which the capital letters stand for Indole, Methyl red, Voges-Proskauer, and Citrate.) The IMViC set of tests examines: the ability of an organism to (1) produce Indole; (2) produce sufficient acid to change the color of Methyl red indicator; (3) produce acetoin, an intermediate in the butanediol fermentation pathway (a positive result of the Voges-Proskauer test); and (4) the ability to grow on Citrate as the sole source of carbon. E. coli is positive in the first two tests and negative in the second two; nonfecal coliforms are the opposite - negative in the first two tests and positive for the second two.
If E. coli is detected in water, it is an indication of fecal pollution. Most-likely the strain of E. coli is a harmless non pathogen, but the indication is that other pathogenic intesdtinal microbes could also be present. The pathogenic fecal coliforms (e.g. Salmonella and Shigella ) can be readily distinguished from strains of E. coli on the basis of a lactose fermentation test. All strains of E. coli ferment the sugar lactose while those of Salmonella and Shigella do not.
The International Commission on Microbiological Specifications for Foods (ICMSF, 1978) has adopted a set of standard techniques for the enumeration of E. coli in food products, accepted by the International Standards Organization (ISO, 1984). This method employs the use of lauryl sulfate tryptose broth at 35 or 37°C as a mildly selective-enrichment medium. This is followed by growth in EC broth containing 0.15% bile salts at 45°C as a second selective step. The ability to produce indole from tryptophan (in tryptone broth) at 45°C defines the strains as E. coli. These tests miss some types of E. coli, such as those most closely related to the Shigella group, but it is the detection of possible fecal contamination that is important in these tests rather than the presence of specific types.
There is no method for the detection of E. coli in water that is accepted throughout the world. In the US, a standard method using membrane filter enumeration for both total and thermotolerant coliforms has been established (American Public Health Association (1986). Further IMViC tests on selected isolates can then be performed as described above.
In the UK, the definition of E. coli in water microbiology is also based on the ability to produce gas from lactose and produce indole from tryptophan at 44°C. A method for enumeration employs a standard multiple tube test with a modified glutamate synthetic medium at 37°C as a first selective step, followed by further cultivation in standard media at 44°C.
le large numbers of E. coli will be found in fecal specimens or specimens contaminated with feces or intestinal contents, most other clinical specimens are usually not contaminated with E. coli. The major exception is urine, which requires special attention in the clinical situation. From those specimens in which E. coli is likely to be present in large numbers, direct plating on media such as MacConkey agar or Eosin Methylene Blue (EMB) agar is sufficient. If the number of E. coli is likely to be very low or the amount of specimen is limited, enrichment in a rich nutrient medium such as brain heart infusion broth may be used. A number of different commercially available kits are generally used to identify the isolates as E. coli.
From specimens likely to contain only a few viable E. coli cells, such as blood from patients suspected of having E. coli bacteremia, various enrichment procedures are used. Identification follows standard bacteriological techniques.
A fluorogenic detection method has been developed based on the cleavage of methylumbelliferyl-D-glucuronide (MUG) to the free methylumbelliferyl moiety, which fluoresces a blue color after irradiation with long-wave ultraviolet radiation. Although strains of E. coli are generally positive in this test, some strains of Salmonella, Shigella, and Yersinia are also capable of splitting MUG; the latter two genera are usually not present in food. A disadvantage is that enterohemorhagic E. coli (EHEC) strains are generally negative in this test. MUG can be added to various selective media, so there is a great potential in its use for detecting E. coli.
Automated or semi-automated systems are also being used for the detection of E. coli as part of the detection methods for Enterobacteriaceae. Techniques involving impedance measurements have shown promise. Other techniques such as immunoassays and nucleic acid hybridization studies can also be used to enumerate E. coli, and DNA probes directed at a number of genes have also been developed.
Physiologically, E. coli is versatile and well-adapted to its characteristic habitats. In the laboratory it can grow in media with glucose as the sole organic constituent. Wild-type E. coli has no growth factor requirements, and metabolically it can transform glucose into all of the molecular components that make up the cell. The bacterium can grow in the presence or absence of O2. Under anaerobic conditions it will grow by means of fermentation, producing characteristic "mixed acids and gas" as end products. However, it can also grow by means of anaerobic respiration, since it is able to utilize NO3 or fumarate as final electron acceptors for respiratory electron transport processes. In part, this adapts E. coli to its intestinal (anaerobic) and its extraintestinal (aerobic or anaerobic) habitats.
In the ecological niches that E. coli occupies and its abilities to grow both aerobically and anaerobically are important. E. coli is well adapted to its intestinal environment as it is able to survive on a relatively limited number of low-molecular weight substances, which may only be available transiently and at relatively low concentrations. The generation time for E. coli in the intestine is thought to be about 12 hours. The type of nutrients available there to E. coli consist of mucus, desquamated cells, intestinal enzyme secretions, and incompletely digested food. Given the absorption capacity and efficiency of the intestine, there are probably only small amounts free carbohydrates or other easily absorbable forms of nutrients, and there is competition from hundreds of other types pf bacteria. A similar situation probably also applies to sources of nitrogen.
In its natural environment, as well as the laboratory, E. coli can respond to environmental signals such as chemicals, pH, temperature, osmolarity, etc., in a number of very remarkable ways considering it is a single-celled organism. For example, it can sense the presence or absence of chemicals and gases in its environment and swim towards or away from them. Or it can stop swimming and grow fimbriae that will specifically attach it to a cell or surface receptor. In response to changes in temperature and osmolarity, it can vary the pore diameter of its outer membrane porins to accommodate larger molecules (nutrients) or to exclude inhibitory substances (e.g. bile salts). With its complex mechanisms for regulation of metabolism the bacterium can survey the chemical content its environment in advance of synthesizing any enzymes necessary to use these compounds. It does not wastefully produce enzymes for degradation of carbon sources unless they are available, and it does not produce enzymes for synthesis of metabolites if they are available as nutrients or growth factors in the environment.
The commensal E. coli strains that inhabit the large intestine of all humans and warm-blooded animals comprise about 1% of the total bacterial biomass. This E. coli flora is in constant flux. One study on the distribution of different E. coli strains colonizing the large intestine of women during a one year period (in a hospital setting) showed that 52.1% yielded one serogroup, 34.9% yielded two, 4.4% yielded three, and 0.6% yielded four. The most likely source of new serotypes of E. coli is acquisition by the oral route. To study oral acquisition, the carriage rate of E. coli carrying antibiotic-resistance (R) plasmids was examined among vegetarians, babies, and nonvegetarians. It was assumed that nonvegetarians might carry more E. coli with R factors due to their presumed high incidence in animals treated with growth-promoting antimicrobial agents. However, omnivores had no higher an incidence of R-factor-containing E. coli than vegetarians, and babies had more resistant E. coli in their feces than nonvegetarians. No suitable explanation could be offered for these findings. Besides, investigation of the microbial flora of the uninhabited Krakatoa archipelago has shown the presence of antibiotic-resistant E. coli associated with plants.
Uropathogenic E. coli cause 90% of the urinary tract infections (UTI) in anatomically-normal, unobstructed urinary tracts. The bacteria colonize from the feces or perineal region and ascend the urinary tract to the bladder. Bladder infections are 14-times more common in females than males by virtue of the shortened urethra. The typical patient with uncomplicated cystitis is a sexually-active female who was first colonized in the intestine with a uropathogenic E. coli strain. The organisms are propelled into the bladder from the periurethral region during sexual intercourse. With the aid of specific fimbriae they are able to colonize the bladder.
The frequency of the distribution of the host cell receptor for the bacterial fimbriae plays a role in susceptibility and explains why certain individuals have repeated UTI caused by E. coli. Uncomplicated E. coli UTI virtually never occurs in individuals lacking the receptors.
Neonatal meningitis affects 1/2,000-4,000 infants. Eighty percent of E. coli strains involved synthesize K-1 capsular antigens (K-1 is only present 20-40% of the time in intestinal isolates).
E. coli strains invade the blood stream of infants from the nasopharynx or GI tract and are carried to the meninges.
Epidemiologic studies have shown that pregnancy is associated with increased rates of colonization by K-1 strains and that these strains become involved in the subsequent cases of meningitis in the newborn. Probably, the infant GI tract is the portal of entry into the bloodstream. Fortunately, although colonization is fairly common, invasion and the catastrophic sequelae are rare.
Neonatal meningitis requires antibiotic therapy that usually includes ampicillin and a third-generation cephalosporin.
As a pathogen, E. coli, of course, is best known for its ability to cause intestinal diseases. Five classes (virotypes) of E. coli that cause diarrheal diseases are now recognized: enterotoxigenic E. coli (ETEC), enteroinvasive E. coli (EIEC), enterohemorrhagic E. coli (EHEC), enteropathogenic E. coli (EPEC), and enteroaggregative E. coli (EAggEC). Each class falls within a serological subgroup and manifests distinct features in pathogenesis.
Posted on 3/31/2008 04:44:00 PM
Definition
Essential to human health, omega-3 fatty acids are a form of polyunsaturated fats that are not made by the body and must be obtained from a person's food.
Purpose
Eating foods rich in omega-3 fatty acids is part of a healthy diet and helps people maintain their health.
Description
In recent years, a great deal of attention has been placed on the value of eating a low fat diet. In some cases, people have taken this advice to the extreme by adopting a diet that is far too low in fat or, worse yet, a diet that has no fat at all. But the truth is that not all fat is bad. Although it is true that trans and saturated fats, which are found in high amounts in red meat, butter, whole milk, and some prepackaged foods, have been shown to raise a person's total cholesterol, polyunsaturated fats can actually play a part in keeping cholesterol low. Two especially good fats are the omega-3 fatty acids and the omega-6 fatty acids, which are polyunsaturated.
Two types of omega-3 fatty acids are eicosapentaenoic acid (EPA) and docosahexanoic acid (DHA), which are found mainly in oily cold-water fish, such as tuna, salmon, trout, herring, sardines, bass, swordfish, and mackerel. With the exception of seaweed, most plants do not contain EPA or DHA. However, alpha-linolenic acid (ALA), which is another kind of omega-3 fatty acid, is found in dark green leafy vegetables, flaxseed oil, fish oil, and canola oil, as well as nuts and beans, such as walnuts and soybeans. Enzymes in a person's body can convert ALA to EPA and DHA, which are the two kinds of omega-3 fatty acids easily utilized by the body.
Many experts agree that it is important to maintain a healthy balance between omega-3 fatty acids and omega-6 fatty acids. As Dr. Penny Kris-Etherton and her colleagues reported in their article published in the American Journal of Nutrition an over consumption of omega-6 fatty acids has resulted in an unhealthy dietary shift in the Americandiet. The authors point out that what used to be a 1:1 ratio between omega-3 and omega-6 fatty acids is now estimated to be a 10:1 ratio. This poses a problem, researchers say, because consuming some of the beneficial effects gained from omega-3 fatty acidsare negated by an over consumption of omega-6 fatty acids. For example, omega-3 fatty acids have anti-inflammatory properties, whereas omega-6 fatty acids tend to promote inflammation. Cereals, whole grain bread, margarine, and vegetable oils, such as corn, peanut, and sunflower oil, are examples of omega-6 fatty acids. In addition, people consume a lot of omega-6 fatty acid simply by eating the meat of animals that were fed grain rich in omega-6. Some experts suggest that eating one to four times more omega-6 fatty acids than omega-3 fatty acids is a reasonable ratio. In other words, as dietitians often say, the key to a healthy diet is moderation and balance.
The Health Benefits of Omega-3 Fatty Acids
There is strong evidence that omega-3 fatty acids protect a person against atherosclerosis andtherefore against heart disease and stroke, as well as abnormal heart rhythms that cause sudden cardiac death, and possibly autoimmune disorders, such as lupus and rheumatoid arthritis. In fact, Drs. Dean Ornish and Mehmet Oz, renowned heart physicians, said in a 2002 article published in O Magazine that the benefits derived from consuming the proper daily dose of omega-3 fatty acids may help to reduce sudden cardiac death by as much as 50%. In fact, in an article published by American Family Physician, Dr. Maggie Covington, a clinical assistant professor at the University of Maryland, also emphasized the value of omega-3 fatty acids with regard tocardiovascular health and referred to one of the largest clinical trials to date, the GISSI-Prevenzione Trial, to illustrate her point. In the study, 11,324 patients with coronary heart disease were divided into four groups: one group received 300 mg of vitamin E, one group received 850 mg of omega-3 fatty acids, one group received the vitamin E and fatty acids, and one group served as the control group. After a little more than three years, "The group given omega-3 fatty acids only had a 45% reduction in sudden death and a 20% reduction in all-cause mortality," as stated by Dr. Covington.
According to the American Heart Association (AHA), the ways in which omega-3 fatty acids may reduce cardiovascular disease are still being studied. However, the AHA indicates that research as shown that omega-3 fatty acids:
* decrease the risk of arrthythmias, which can lead to sudden cardiac death
* decrease triglyceride levels
* decrease the growth rate of atherosclerotic plaque
* lower blood pressure slightly
In fact, numerous studies show that a diet rich in omega-3 fatty acids not only lowers bad cholesterol, known as LDL, but also lowers triglycerides, the fatty material that circulates in the blood. Interestingly, researchers have found that the cholesterol levels of Inuit Eskimos tend to be quite good, despite the fact that they have a high fat diet. The reason for this, research has found, is that their diet is high in fatty fish, which is loaded with omega-3 fatty acids. The same has often been said about the typical Mediterranean-style diet.
Said to reduce joint inflammation, omega-3 fatty acid supplements have been the focus of many studies attempting to validate its effectiveness in treating rheumatoid arthritis. According to a large body of research in the area, omega-3 fatty acid supplements are clearly effective in reducing the symptoms associated with rheumatoid arthritis, such as joint tenderness and stiffness. In some cases, a reduction in the amount of medication needed by rheumatoid arthritis patients has been noted.
More research needs to be done to substantiate the effectiveness of omega-3 fatty acids in treating eating disorders, attention deficit disorder, and depression. Some studies have indicated, for example, that children with behavioral problems and attention deficit disorder have lower than normal amounts of omega-3 fatty acids in their bodies. However, until there is more data in these very important areas of research, a conservative approach should be taken, specially when making changes to a child's diet. Parents should to talk to their child's pediatrician to ascertain if adding more omega-3 fatty acids to their child's diet is appropriate. In addition, parents should take special care to avoid feeding their children fish high in mercury. A food list containing items rich in omega-3 fatty acids can be obtained from a licensed dietitian.
Mercury Levels and Concerns About Safety
A great deal of media attention has been focused on the high mercury levels found in some types of fish. People concerned about fish consumption and mercury levels can review public releases on the subject issued by the U. S. Food and Drug Administration and the Environmental Protection Agency. Special precautions exist for children and pregnant or breastfeeding women. They are advised to avoid shark, mackerel, swordfish, and tilefish. However, both the U.S. Food and Drug Administration and the Environmental Protection Agency emphasis the importance of dietary fish. Fish, they caution, should not be eliminated from the diet. In fact, Robert Oh, M.D., stated in his 2005 article, which was published in The Journal of the American Board of Family Practice "With the potential health benefits of fish, women of childbearing age should be encouraged to eat 1 to 2 low-mercury fish meals per week."
Other concerns regarding fish safety have also been reported. In 2004, Hites and colleagues assessed organic contaminants n salmon in an article published in Science. Their conclusion that farmed salmon had higher concentrations of polychlorinated biphenyls than wild salmon prompted public concerns and a response from the American Cancer Society. Farmed fish in Europe was found to have higher levels of mercury than farmed salmon in North and South America; however, the American Cancer Society reminded the public that the "levels of toxins Hites and his colleagues found in the farmed salmon were still below what the U. S. Food and Drug Administration, which regulates food, considers hazardous." The American Cancer Society still continues to promote a healthy, varied diet, which includes fish as a food source.
Recommended Dosage
The AHA recommends that people eat two servings of fish, such as tuna or salmon, at least twice a week. A person with coronary heart disease, according to the AHA, should consume 1 gram of omega-3 fatty acids daily through food intake, most preferably through the consumption of fatty fish. The AHA also states that "people with elevated triglycerides may need 2 to 4 grams of EPA and DHA per day provided as a supplement," which is available in liquid orcapsule form. Ground or cracked flaxseed can easily be incorporated into a person's diet by sprinkling it over salads, soup, and cereal.
Sources differ, but here are some general examples:
* 3 ounces of pickled herring = 1.2 grams of omega-3 fatty acids
* 3 ounces of salmon = 1.3 grams of omega-3 fatty acids
* 3 ounces of halibut = 1.0 grams of omega-3 fatty acids
* 3 ounces of mackerel = 1.6 grams of omega-3 fatty acids
* 1 1/2 teaspoons of flaxseeds = 3 grams of omega-3 fatty acids
Precautions
In early 2004, the U.S. Food and Drug Administration, along with the the Environmental Protection Agency, issued a statement that women who are or may be pregnant, as well as breastfeeding mothers and children, should avoid eating some types of fish thought to contain high levels of mercury. Fish that typically contain high levels of mercury are shark, swordfish, and mackerel, whereas shrimp, canned light tuna, salmon, and catfish are generally thought to have low levels of mercury. Because many people engage in fishing as a hobby, women should be sure before they eat any fish caught by friends and family that the local stream or lake is considered low in mercury.
Conflicting information exists whether it is safe for patients with macular degeneration to take omega-3 fatty acids in supplement form. Until more data becomes available, it is better for people with macular degeneration to receive their omega-3 fatty acids from the food they eat.
Side Effects
Fish oil supplements can cause diarrhea and gas. Also, the fish oil capsules tend to have a fishy aftertaste.
Interactions
Although there are no significant drug interactions associated with eating foods containing omega-3 fatty acids, patients who are being treated with blood-thinning medications shouldn't take omega-3 fatty acid supplements without seeking the advice of their physicians. Excessive bleeding could result. For the same reason, some patients who plan to take more than 3 grams of omega-3 fatty acids in supplement form should first seek the approval of their physicians.
