A "ubiquitous" chemical widely used in the manufacture of non-stick frying pans is linked to thyroid disease, researchers say.

A study involving almost 4,000 people in the United States found people that those with the highest levels of man-made perfluorooctanoic acid - also known as PFOA - in their blood were twice as likely to be diagnosed with thyroid disease or taking medication compared with those with the lowest levels.

PFOA is widely used in industry because it excels at repelling heat, water, grease and stains, and traces of the chemical are found in water, air and soil throughout the world.

But the researchers from the University of Exeter, who carried out the latest study, stressed that further research was needed to establish whether the chemical was a direct cause of illness in humans.

Previous studies in animals have suggested that high exposure to the chemical can affect the action of the thyroid gland, located in the neck, which is responsible for controlling the body's rate of metabolism through the release of hormones.

Tamara Galloway, Professor of Ecotoxicology at Exeter, said that it was likely that the chemical could be ingested or inhaled from the air or as a component of household dust, and might stay in the bloodstream for about five days.

Her team analysed an American database of 3,966 adults aged 20 and older, because no figures for blood levels of PFOA is available in Britain. Of these, 163 women and 46 men reported having current thyroid disease and were taking medication.

But a total of 16 per cent of women with the highest blood levels of the chemical (above 5.7ng/ml) reported having thyroid disease or were taking related medication, compared to 8 per cent of those with the lowest levels. the trend was similar in men, but not said to be statistically significant because of the low numbers of individuals involved.

"Our results highlight a real need for further research into the human health effects of low-level exposures to environmental chemicals like PFOA that are ubiquitous in the environment and in people's homes. We need to know what they are doing," Professor Galloway said.

But Diane Benford, Head of Toxicology of Food, Food Standards Agency, commented: "This type of study investigates associations and cannot establish causality. It is important to look at the consistency of the data with the results of other studies, and with what is known about the toxicity of PFOA and PFOS, which differ.

"Studies of workers with higher exposure to these compounds have not shown consistent evidence of increased risk of thyroid disease, which would be expected if effects are occurring in the general population. More research is needed to establish whether this association is causal."

Ashley Grossman, Professor of Neuroendocrinology, at Queen Mary, University of London, said that it was also unknown how PFOA might affect the thyroid gland.

"Thyroid disease is often caused by the body's own immune system attacking the thyroid gland so perhaps this chemical is having some effect on the immune system, rather than directly on the thyroid," he said.

"We'd need to do a lot more research to verify this link and to understand how the two are linked. In the meantime, it's important to remember that thyroid disease can be successfully treated."

Breast cancer screening may not be appropriate for all women, warned the experts from the University of Michigan. A genetic mutation that plays a significant role in increasing a woman's risk of developing breast cancer and ovarian cancer has been discovered.

Breast cancer, estimated to increase by 3 percent per annum up to 2015 in India, result from genetic abnormalities. However, only five to ten percent of the cases are due to inherited genetic factors, mostly due to abnormalities in two genes, BRCA1 and BRCA2. These two genes may be inherited from either of the parents and may pose a higher lifetime risk of developing breast and ovarian cancer, more likely to develop at an earlier stage.

Lifetime risk of breast cancer in these women jumps from 12.5 percent in the general population to approximately 60 percent in women with BRCA mutations. It should also be kept in mind that occurance of most of breast and ovarian cancers are random and may not be due to BRCA gene inheritence.

According to Dr Sofia Merajver, director of the Breast and Ovarian Risk Evaluation Program at the University of Michigan Comprehensive Cancer Centre, it is important that the right women seek out genetic testing for breast and ovarian cancer.

Though it is a simple blood test, the interpretation of the results may be complicated. Doctors recommend genetic testing for those with family history of cancer cases and diagnoses through several generations, older family members (above 50) diagnosed with cancer, family member with cases of multiple cancers like breast and ovarian and also male breast cancer, or other cancers like colon, stomach or prostrate cancers.

Undergoing genetic tests can help assess the risk factor of the person diagnosed with cancer.

A new technique to remove uterine fibroids without surgery will soon be available in the city. Jaslok Hospital in south Mumbai is set to launch Magnetic Resonance (MR)-focused ultrasound system to remove them. The non-invasive procedure uses high intensity ultrasound waves to ablate tissue in combination with Magnetic Resonance Imaging (MRI) that guides, monitors and controls the treatment.

Uterine fibroids are non-cancerous tumours found in women aged between 30 and 40. "Submucosal fibroids develop just under the lining of the uterine cavity and causes heavy bleeding, infertility and even miscarriages. They need to be removed without harming other organs," said Dr Rishma Pai, obstetrician, gynaecologist and infertility specialist at Jaslok Hospital.

"This procedure will stop the fibroid to recur again in the same region and increases the chances of fertility."

"Ultrasound is a form of energy that can pass through skin, muscle, fat and other soft tissues. High intensity ultrasound waves focused on a small target raises the temperature and destroys the tissue. This procedure is called thermal ablation," said Dr W M Gedroye, consultant radiologist at St Mary's Hospital in London. Dr Gedroye has treated over 500 patients using this technology. "Success rate is about 80 per cent," he said.

Studies show that this procedure can even remove liver tumours. "Studies are under way in Japan to establish this procedure can successfully treat breast and prostrate cancer also," said Dr Gedroye.

New research at the University of Michigan suggests that every 1.1 pounds of birth weight reduces the possibility of developing tuberculosis later in life by almost 46percent in identical twins.

According to Eduardo Villamor, study author and associate professor at the U-M School of Public Health, tuberculosis risk came down by 87percent for each pound in males, whereas it was only about 16 percent for every 1.1 pounds of birth weight in girls.

Villamor, who worked with a team at the Karolinska Institute in Sweden and began the research at Harvard, also pointed out that low birth weight of babies is widespread problem in developing countries, but prevalent elsewhere too.

Although Villamor said it is too early to conclude that insufficient prenatal growth leads to clinical tuberculosis, it may be the case.

He added: "Prenatal exposure to environmental insults, including maternal malnutrition, could program what happens later on in terms of our immune responses to infection, possibly through programming of the immune system. This study is an example of that."

The study, "Evidence for an effect of fetal growth on the risk of tuberculosis," will be published in the Feb. 1 edition of the Journal Infectious Disease. (ANI)

A new study has shed light on the role of stem cells in medulloblastomas, the most common type of children's brain tumor.

Researchers at Queen Mary, University of London, studied equivalent cells taken from mouse brains. Principal investigator Silvia Marino, Professor of Neuropathology at Queen Mary, University of London, and her team showed that medulloblastomas can grow from a type of brain stem cell and that these cancers are a distinct form of the disease which may require a completely different approach to treatment.

She said "This type of brain tumour can pose a great challenge to doctors. In some children, treatment works well but in others the cancer is aggressive and far harder to treat. As scientists we have been trying to understand how these cancers which look the same can behave so differently. This study is a major advance for us because it shows for the first time that some of these tumours develop from endogenous stem cells."

She added " This is important for two reasons. First, it could help us to tell which cancers will respond well to treatment and which will need a more aggressive therapy. Second, this new understanding could help us to find much-needed new drugs for the disease."