World Health Day on April 7:

Use antibiotics rationally

By Nilma DOLE

It has become an uncontrolled tendency for patients to misuse antibiotics instead of heeding a doctor's advice. More often than not, some even decide for themselves what course of drugs they should take and what medicines they require to buy over-the-counter. "It has become a kind of phenomena where patients decide for themselves what antibiotics to take and what adds to the problem is the fact that unprofessional pharmacists actually give these patients the drugs without a prescription," said Prof. Gita Fernando, Professor of Pharmacology at the Medical Sciences faculty, Sri Jayawardenapura University. She was speaking at a health seminar at the Health Education Bureau held in lieu of World Health Day that falls on April 7.

According to her, antimicrobial medicines are drugs used to destroy or prevent the growth of microbes whereas antibiotics are medicines which kill bacteria and/or prevent their growth later.

Benefits

"Antibiotics have to be efficient in working to cure a patient, it needs to be safe for the patient to use with minimum side effects, it has to be of good quality and has to be cost effective so that the patient can afford it," she said. Overall, the benefits should outweigh the risks when it comes to administering antibiotics to a patient.

Antibiotics: benefits should outweigh risks

"The rational use of antibiotics is selecting an appropriate antibiotic based in definitive or probable diagnoses pertaining to bacterial infection. The correct use of dosage should be properly told to the patient because if they misunderstand the doctor or don't adhere the doctor's advice, they won't be cured quickly.

"No matter how much we train professionals in pharmacology and qualified pharmacists, patients still continue to take medication without adhering doctor's advice because if they don't take the drugs as prescribed, they will not heal soon. Hence, it should be made compulsory even by law that unless a patient takes a course of drugs the proper way, they can't blame it on the doctor and go for a second opinion immediately," said Prof. Fernando.

The professor said that the 'second opinion syndrome' is rampant among patients today.

"When someone becomes sick with a common cold or a 'flu, they want a quick fix so they don't heed their doctor's advice to drink fluids, take rest and eat well. Instead they go for a second opinion until a doctor gives some antibiotics to give a 'quick fix' so that they can go back to work," she said. A patient needs rest and not resting would lead to much bigger problems which will have bad consequences.

Prof. Fernando said, "It is necessary to use antibiotics only if there is a bacterial infection such as meningitis, urinary tract infection or pneumonia but when it comes to a virus infection such as the common cold or diarrhoea then antibiotics are not required."

More often than not, Prof.Fernando said that she advises patients to take simple traditional cures when it comes to reducing a viral infection such as drinking crushed cumin seeds to stop diarrhoea.

Doses

"Administration of a drug depends on optimal doses, frequency, and selecting the appropriate route. The patient has to continue the treatment until they are cured and the doctor should check a test for the cure which would be ideally microbial,"she said. There are several problems from use of antibiotics and the professor said that 24 percent of antibiotics are taken which are not intended for the particular patient and more often than not, old prescriptions are used. "Take antibiotics that are prescribed, ask your doctor about the drug, especially about storage and usage. Do not ever use antibiotics of old prescriptions, old tablets or from another patient's prescription," said the professor. She said that a patient should avoid self-medication and report to a doctor about side effects instead of deciding that they won't use the antibiotics without telling the doctor. "In my years of experience, no matter how much I tell the patient to be patient in getting cured, there have been several cases where patients have demanded antibiotics from me for no reason at all.

My advice would be that you shouldn't do this because it is the doctor who knows what's best for you."

The most commonly used antibiotics are pencilliin, erythromycin, ciprofloxcin and gentamicin which are available in pharmacies but patients should never buy them over-the-counter without heeding doctors warnings because it might have serious complications. "Talk to a doctor before taking medicines because every individual is different and unique. So a certain medication might work for one person but it won't work for another," she said.

Damaging

What patients don't know is that antibiotics can cause damaging problems if they are not taken in the proper manner. "Patients who regularly use antibiotics sometimes won't be cured completely because certain dangerous microbes in the body can develop resistance to the drugs," said Prof.Fernando.

"In Sri Lanka, since the health industry is a big field and people are serious about it, patients should be knowledgeable in knowing what they put into their bodies.

"Before you buy medicine with a prescription from a doctor, do some background study or check for information of the drug so that you know what you're taking.

It is important to get patients the right information because it would be a matter of life and death," said the Professor.

According to the World Health Organisation's (WHO) theme on 'Use Antibiotics Rationally' as the theme for World Health day this year, "Antimicrobial resistance is not a new problem but one that is becoming more dangerous; urgent and consolidated efforts are needed to avoid regressing to the pre-antibiotic era.

On World Health Day 2011, WHO will introduce a six-point policy package to combat the spread of antimicrobial resistance."

Next-generation disease fighters: 'Bacterial Dirigibles'

Scientists have reported development of bacteria that serve as mobile pharmaceutical factories, both producing disease-fighting substances and delivering the potentially life-saving cargo to diseased areas of the body. They reported on this new candidate for treating diseases ranging from food poisoning to cancer - termed "bacterial dirigibles" - at the 241st National Meeting & Exposition of the American Chemical Society, being held here.

"We're building a platform that could allow bacterial dirigibles to be the next-generation disease fighters," said study leader William E.

Bentley, Ph.D. "The concept is unique."

Bentley explained that traditional genetic engineering reprograms bacteria so that they produce antibiotics, insulin, and other medicines and materials. The bacteria grow in nutrient solutions in enormous stainless steel vats in factories. They release antibiotics or insulin into vats, and technicians harvest the medicine for processing and eventual use in people.

The bacterial dirigible approach takes bioengineering a step further.

Scientists genetically modify bacteria to produce a medicine or another disease-fighting substance. Then, however, they give the bacteria a biochemical delivery address, which is the locale of the disease. Swallowed or injected into the body, the bacteria travel to the diseased tissue and start producing substances to fight the disease.

Bentley chose the term "bacterial dirigibles" because the modified bacteria actually have the fat-cigar look of blimps and zeppelins, those famous airships of yesteryear. In addition, the bacteria seem to float like a blimp as they make deliveries.

The prototype bacterial dirigible is a strain of E. coli that Bentley and colleagues developed at the University of Maryland in College Park, where he is Robert E. Fischell Distinguished Professor and Chair of the Fischell Department of Bioengineering.

"We have created a genetic circuit that endows E. coli with targeting, sensing and switching capabilities," Bentley explained. "The resultant cell is a bacterial dirigible - a cell that autonomously navigates and carries or deploys important 'cargo'."

The "targeting" molecule is attached to the outer surface of the bacteria. It gives the bacteria an ability to "hone in" on specific cells and attach to them - in this instance, the intestinal cells where other strains of E. coli cause food poisoning symptoms. Inside the bacteria is a gene segment that acts as "nanofactory." It uses the bacteria's natural cellular machinery to make drugs, such as those that can fight bacterial infections, viruses, and cancer.

The nanofactory also could produce signalling molecules that enable the dirigible to communicate with natural bacteria at the site of an infection. Some bacteria engage in a biochemical chit-chat, termed "quorum sensing," in which they coordinate the activities needed to establish an infection.

Bacteria dirigibles could produce their own signalling molecules that disrupt quorum sensing, preventing bacteria from starting an infection.The nanofactory also could produce chemical signals that trigger cells lining the stomach or other parts of body to synthesize natural disease-fighting substances, such as immunoglobulin.

Immunoglobulin are proteins used by the immune system to identify and destroy foreign objects, such as bacteria and viruses."The bacterial dirigibles can send out a strong signal to which disease-fighting cells of the body can respond," Bentley noted. "The chemical signals tell the cells to attack the body's foreign invaders, including the bacteria that cause food poisoning."

Bacterial dirigibles could be given to patients in the form of probiotics, live microorganisms that are beneficial to health like those found in certain kinds of yogurt, Bentley said. Doctors could also inject dirigibles into the bloodstream or directly into a diseased area, such as a tumour, he said.

(Source: Michael Bernstein Michael Woods American Chemical Society)

Are we eating plastic?

Plastics are inseparable from our food. Our food gets processed, packaged, transported, stored and even cooked and re-heated in plastic, in case we're using the microwave oven.

With our food always touching plastic, haven't you wondered if the aftertaste of this convenience could be harmful to our health? Recent discussions in this space indicate that you do have cause to worry.

Leaching of plastics

The process by which minute bits of plastic get into our food from containers is called "leaching". Almost any plastic container can be expected to leach trace amounts of plastics into food - a fact that the chemical industry acknowledges - though the amount of transfer is variable.

* Heating food in plastic seems to increase the amount that's transferred into food.

* Leaching also increases when plastics touch fatty, salty or acidic foods.

So, if plastic leaching into food is inevitable, how safe is the food we eat? Well, the little research that's gone into the ill-effects of plastics leaching into our bodies suggests that two class of chemicals are clearly guilty of potential health hazards:

Bisphenol A (BPA)

BPA is a common chemical used in hard, lightweight plastics called polycarbonates.

Effects on health

* BPA is an endocrine disrupter, which means it has the ability to disrupt the functions of hormones - especially oestrogen (female sex hormone), which may result in disruption of reproductive development and function.

* One study showed that people who had high levels of BPA in the urine had a higher rate of diabetes, heart disease, and liver toxicity.

* Obesity maybe increased as a function of BPA exposure.

* Perinatal exposure to low doses of BPA alters breast development and increases breast cancer risk.

* Research has found a connection between BPA and interference with brain cell connections vital to memory, learning and mood.

Gene, lack of B vitamin linked to increased colon cancer risk in mice

Offering a likely insight into how such cancers develop in humans researchers report they have identified a gene that increases the risk for colon cancer in laboratory mice when the animals' diets are deficient in folate.

The new study, "Shmt1 Heterozygosity Impairs Folate-Dependent Thymidylate Synthesis Capacity and Modifies Risk of Apcmin-Mediated Intestinal Cancer Risk," published in the March issue of the peer-reviewed journal Cancer Research, provides evidence that a combination of folate deficiency and reduced expression of the SHMT1 gene, which is required for accurate DNA synthesis, boosts the risk of colon cancer in a mouse model. The study indicates that the SHMT1 gene may be a factor in itself, and also demonstrates how dietary folate, a B vitamin, may interact with an individual's genetic make-up to increase colon cancer risk.

"Nutrition and genetics work together to contribute to the creation of cancer cells and, based on the similarity of folate metabolism in mice and humans, it is likely that this gene is associated with human colon cancer," said Patrick Stover, professor in the Division of Nutritional Sciences and the senior author of the paper.Colorectal cancer is the second leading cause of cancer-related deaths in the United States, claiming more than 50,000 lives each year.

"Molecular antecedents that promote development of sporadic colon cancer include DNA damage. Lack of critical nutrients increases rates of DNA damage. Therefore, lack of folate has the potential to induce this damage that ultimately results in transforming normal cells to cancer cells," said Stover. Screening for colorectal cancer is recommended for all individuals over 50; however, close to 40 percent of the U.S. population in this age group does not take this precautionary method. Individuals who choose not to pursue colonoscopies may want to ensure their diets contain adequate amounts of folate, Stover said. The U.S. recommended daily allowance for folate is 400 micrograms per day. Foods that are rich in folate include many fruits and vegetables, grains, legumes, nuts and seeds.

Source: Cornell University

Scientists find candidate for new TB vaccine

Scientists have discovered a protein secreted by tuberculosis (TB) bacteria that could be a promising new vaccine candidate, they report today in Proceedings of the National Academy of Sciences. The protein could also be used to improve diagnosis of TB.

TB is caused by the bacterium Mycobacterium Tuberculosis (MTB), which infects the lungs and spreads through the air as a result of coughing.

There are 9 million new cases of TB each year, killing 4,700 people a day worldwide.

BCG is the only available vaccine but it is of limited effectiveness in protecting against TB. BCG derives from the Mycobacterium bovis bacterium, which infects cattle and is closely related to MTB.

Vaccines work by stimulating the immune system to retain a memory of particular molecules from a microbe that will trigger a rapid immune response if the microbe is encountered later. The best candidates for vaccines are those that trigger the strongest response from the immune system.

In the new study, scientists identified a protein, called EspC, that triggers a stronger immune response in people infected with the TB bacterium than any other known molecule. This protein is secreted by the TB bacterium but not by the BCG vaccine. As a result, the BCG vaccine does not induce an immune response to this protein, so deploying it as a new TB vaccine would provide additive immunity over and above that provided by BCG.

The protein could also be useful as a diagnostic tool, because an immune response to it is seen in TB-infected people, but not in non-infected people who have had a BCG vaccine. Detecting immune responses to it would distinguish BCG-vaccinated people from TB-infected people, which the currently-used tuberculin skin prick test (the Mantoux test) is unable to do.

The new protein could thus underpin the next-generation of immune cell-based blood tests for TB infection, known as interferon-gamma release assays (IGRAs). The researchers believe it could provide increased diagnostic sensitivity without compromising a test's ability to discriminate between BCG-vaccination and TB infection.

"Despite most of the world's population having had a BCG vaccination, there are still 9 million new cases of TB every year," said senior author Professor Ajit Lalvani, from the National Heart and Lung Institute at Imperial College London. "So we urgently need to develop a more effective vaccine for TB.

"We've shown that EspC, which is secreted by the bacterium, provokes a very strong immune response, and is also highly specific to MTB. This makes it an extremely promising candidate for a new TB vaccine that could stimulate broader and stronger immunity than BCG. Surprisingly, our results also show that this molecule could underpin next-generation diagnostic blood tests that can rapidly detect latent TB infection."

In the study published today, which was funded by the Wellcome Trust, Professor Lalvani and his colleagues looked at how the immune system responded to EspC in 45 people with active TB, 27 people with latent TB infection, and 27 uninfected BCG-vaccinated controls. They found that EspC elicited immune responses at least as strongly as other proteins known to be targeted by the immune system in people with active and latent TB infection. Only two out of 27 BCG-vaccinated controls responded to the antigen, demonstrating the specificity of the response. Further experiments revealed that this is because the TB vaccine lacks genes that are needed to secrete EspC.

(Sources: Imperial College London, AlphaGalileo Foundation)