Its A Bugs Life, Chapter One

Course of Antibiotics May Prevent Second Heart Attack

Treating heart attack patients with a three-month course of antibiotics could dramatically reduce their risk of having a second heart attack, recent study results suggest.

Results of the study of 148 patients who had had a heart attack or a bout of severe chest pain revealed that those who were given a 3-month course of the antibiotic clarithromycin were 41% less likely to have another heart attack or other cardiovascular event within the following 18-months.

The researchers believe that the antibiotic reduces heart attack risk by eliminating bacteria such as Chlamydia pneumoniae, which are known to inflame blood vessels. Furthermore, clarithromycin itself has anti-inflammatory properties which could also have contributed to the beneficial effect of the drug.

Lead author of the study Dr. Juha Sinisalo, said: "Antibiotics seem to be a beneficial option [for patients with coronary heart disease]." Although, he recommends that if antibiotics were to be used to treat people after heart attack it would be wise to stick with one group of antibiotics as widespread use of many different types of the drugs could worsen the problem of antibiotic resistance.

_{SOURCE/ REFERENCE: Circulation 2002: Published online before print March 11, 2002, 10.1161/01.CIR.0000012544.07696.1F}

Aspirin May Combat Viruses

New research suggests that anti-inflammatory drugs like aspirin could be used to tackle viruses. Researchers from New Jersey Medical School discovered that aspirin can stop a virus called cytomegalovirus (CMV) from reproducing itself. Experiments on CMV suggest that the virus needs body chemicals called prostaglandins in order to replicate. Anti-inflammatory drugs such as aspirin stop the body from producing these inflammatory chemicals, and tests on CMV-infected human tissue showed that anti-inflammatory drugs "significantly reduced" viral replication. Many people are infected with CMV, and there is evidence showing that heart transplant patients infected with the virus are significantly more likely to develop atherosclerosis. It is also thought that dormant CMV may increase the risk of atherosclerosis, and therefore heart disease, in the general population.

_{SOURCE/REFERENCE: Reported by www.bbc.co.uk on the 26th February 2002}

New Test Identifies Patients with High Heart Attack Risk

A team of UK scientists have developed a blood test that can identify patients who are at high risk of having a heart attack. The test, which is currently being tested on 2,500 patients, works be detecting blood levels of a protein called C-reactive protein that is associated with chronic inflammation and chronic infection. According to researchers, the test will identify patients who are three to five times more likely to have a heart attack. Thus, allowing doctors to give priority treatment to those at the greatest risk.

_{SOURCE/REFERENCE: Reported by www.bbc.co.uk on the 9th January 2002}

Childhood Vaccinations May Lower Alzheimer's Risk

A recent study by scientists from a Canadian university has found no evidence to support claims that childhood vaccinations for polio, tetanus, and diphtheria increase a person's risk of developing Alzheimer's disease. Previous research has suggested that immune system changes caused by certain vaccinations could increase the risk of developing age-related conditions like Alzheimer's, however instead of supporting this theory the new study actually found that people who receive one or all of the vaccines may be less likely to develop the neurodegenerative disease. Study results showed that people who were given the tetanus or diphtheria vaccine were 60% less likely to develop Alzheimer's, and those who had the polio vaccine were 40% less likely to develop the disease.

_{SOURCE/REFERENCE: Canadian Medical Association Journal 2001; 165:1495-1498}

Hip Replacement Ups Risk of Certain Cancers

People who have been given a replacement hip joint are significantly more likely to develop certain cancers, suggest results of a recent study. Researchers found that artificial hip recipients were 16% more likely to develop prostate cancer, 15% more likely to develop melanoma, and a massive 86% more likely to develop multiple myeloma - a type of blood cancer. However, results showed that a patient's overall risk of cancer is the same as that of people without artificial joints. The study also showed that stomach cancer rates were 17% lower in people who had undergone hip replacement therapy. The researchers believe that this may be due to antibiotics given to patients' as they will destroy the bacterium Helicobacter pylori, which has been linked to stomach cancer. The study authors stress that their findings may not represent an actual cause and effect relationship between hip replacement and cancer risk. However, several materials commonly used in artificial hips, for example chromium, lead, cobalt, and acrylic, are known, or thought to be carcinogens.

_{SOURCE/REFERENCE: Journal of the National Cancer Institute 2001; 93:1405-1410}

Stronger Immune System Means That Women Live Longer

New research has found evidence to suggest that the reason why women tend to outlive men is that they have stronger immune systems. UK researchers studying the thymus gland, which produces T-cells - a group of white blood cells that fight infection, found that women have significantly higher levels of these cells than man of the same age. This suggests that women have greater infection-fighting capabilities. In order to determine whether this was true, the researchers looked at figures showing the number of deaths caused by pneumonia and influenza in Britain over a five-year period. In line with their findings, they discovered that the diseases killed significantly more men than women. A person's ability to fight infection declines with age, thus the fact that women appear to be more capable of fighting infection could help to explain why they live longer than men.

_{SOURCE/REFERENCE: Reported by www.bbc.co.uk on the 12th September 2001}

Immune System Over-Activation Linked to Cancer

Chronic over-activation of the immune system may play a central role in the development of cancer say British researchers. Inflammation caused by the over-activation of the immune system has been implicated in the pathogenesis of many diseases, however results of a scientific review suggest that the role of inflammation in cancer development has been dramatically under-estimated. Chronic exposure to a carcinogen creates is thought to create an ideal environment for cancer cells by impairing the immune system's ability to fight disease by switching off certain immune cells, causing inflammation, which in turn produces highly reactive molecules that may cause cancer by damaging DNA, and stimulating the growth of blood vessels, thus providing nutrition for cancer cells. The findings suggest that existing anti-inflammatory drugs may be help to prevent and treat cancer by `dampening-down' the immune system.

_{SOURCE/REFERENCE: British Journal of Cancer 2001; 85: 473-483}

Girl Brings Hope of vCJD Cure

A British girl who is thought to be suffering from vCJD, the human form of mad cow disease, has made a remarkable improvement after being given a pioneering drug treatment developed by researchers in the US. Jane Forber, 20, who had been given just a year to live, was confined to a wheelchair and unable to recognise her parents. However, after just 19 days of drug treatment she was able to walk, talk, and successfully complete co-ordination tests. The treatment, developed by a team of scientists led by Nobel Prize Winner Professor Stanley Prusiner, uses the drugs quinacrine and chlorpromazine. Tests on mice cells revealed that the treatment appears to work by preventing healthy prion protein from turning into its disease-causing form.

_{SOURCE/REFERENCE: Reported by www.guardian.co.uk on the 14th August 2001}

Scientists Propose New Mad Cow Theory

A British researcher has unveiled a new theory concerning the cause of mad cow disease and its human equivalent variant Creutzfeld Jakob Disease (vCJD). The currently accepted theory is that the neurodegenerative fatal diseases are caused by a build-up of abnormal protein known as prions, however Dr Tony Gibson, a researcher at the European Molecular Biology Laboratory in Heidelberg, Germany, believes that the diseases are actually caused by genetic parasites that infect DNA. Analysis of the human genetic code has revealed that more than 50% of it consists of parasitic genes, which can in turn carry parasites of their own. The best known example of one of these parasites is the Alu repeat sequence which creates scraps of genetic code known as Alu Sine RNA's, Gibson hypothesises that the production of Alu Sine RNA's can trigger the build-up of protein deposits associated with the disease by blocking an enzyme that controls the manufacture of proteins. Dr Gibson's theory is proven correct it means that simple tests could be developed to determine whether or not a human is infected with the disease.

_{SOURCE/REFERENCE: Reported by www.telegraph.co.uk on the 6th July 2001}

Antibody Removes Alzheimer's Plaques

Experiments on mice have offered hope of a new form of treatment for Alzheimer's disease. Researchers conducting experiments on mice genetically altered to have an Alzheimer's-like illness have found that they can partially clear the animals' brains of beta-amyloid, the principle component of Alzheimer's plaques, by injecting an antibody called m266 into their bloodstream. Scientists throughout the world are currently striving to produce Alzheimer's vaccines, which `train' the immune system to develop antibodies against beta-amyloid protein. However, these findings suggest that the direct injection of an antibody may work just as well. Furthermore, doctors would be able to control a patient's antibody levels - something that would not be possible with the vaccine approach.

_{SOURCE/REFERENCE: Proc. Natl. Acad. Sci. USA, 2001; 10:1073}