Researchers have made a new breakthrough that could help explain why we feel hungry.

In this new paper, first authors Michael Krashes, PhD, and Bhavik Shah, PhD, postdoctoral fellows in the lab of Bradford Lowell , MD, PhD, Beth Israel Deaconess Medical Center (BIDMC) neuroendocrinologist, employed rabies circuit mapping, a technology in which a modified version of the rabies virus is engineered to "infect" just one type of neuron - in this case, the AgRP neurons that drive hunger.

The virus moves upstream one synapse and identifies all neurons that are providing input to AgRP starter neurons. Then, using a host of different neuron-specific cre-recombinase expressing mice (a group of genetically engineered animals originally developed in the Lowell lab) the investigators were able to map inputs to just these nerve cells, and then manipulate these upstream neurons so that they could be targeted

With this new information, the investigators now had a model to pursue.

Their results revealed that subsets of neurons expressing thyrotropin-releasing hormone (TRH) and pituitary adenylate cylcase-activating polypeptide (PACAP) were in on the neuronal chatter.

Finally, through a chemogenetic technique known as DREADDs - Designer Receptor Exclusively Activated by Designer Drug - the authors used chemicals to specifically and selectively stimulate or inhibit these upstream neurons in the animal models.

The fed mice, which had already consumed their daily meal and otherwise had no interest in food, proceeded to search out and voraciously eat after DREADD stimulation. Conversely, the fasting mice - which should have been hungry after a period of no food - ate very little when these upstream neurons were turned off.

The study has been published online in the journal Nature.

A new research has revealed that greater adherence to Mediterranean-style diet was associated with lower risk factors for cardiovascular disease (CVD).

The study led by researchers from Harvard School of Public Health (HSPH) and Cambridge Health Alliance (CHA) is the first to assess the effects of Mediterranean-style diet among a group of young, working US adults.

"Our study adds more evidence showing the health benefits of a Mediterranean diet, even after adjusting for exercise and body weight," Stefanos Kales, associate professor in the Department of Environmental Health at HSPH and chief of occupational and environmental medicine at CHA, said.

US firefighters are known to have a high prevalence of obesity and risk factors for CVD. A Mediterranean diet, rich in fish, nuts, vegetables, and fruits, has been shown in previous studies to lower risk of CVD.

The researchers analyzed medical and lifestyle data, including dietary habits, from an existing cohort of 780 male firefighters in the Midwest.

The firefighter group with greatest adherence to Mediterranean-style diet showed a 35 percent decreased risk in metabolic syndrome, a condition with risk factors that include a large waistline, high triglyceride level, low HDL ("good") cholesterol level, high blood pressure, and high blood sugar.

The group with the highest mMDS also had a 43 percent lower risk of weight gain compared with the lowest mMDS group. Additionally, greater adherence to a Mediterranean-style diet was significantly associated with higher HDL cholesterol and lower LDL ("bad") cholesterol.

The study was published in the journal PLOS ONE.

A team of researchers has discovered a genetic function that helps one of the most important "tumour suppressor" genes to do its job and prevent cancer.

According to scientists from OSU and Oregon Health and Science University, finding ways to maintain or increase the effectiveness of this gene - called Grp1-associated scaffold protein, or Grasp - could offer an important new avenue for human cancer therapies.

The Grasp gene was studied in the skin of mice in this research, but is actually expressed at the highest levels in the brain, heart and lung, studies have shown. It appears to play a fundamental role in the operation of the p53 tumour suppressor gene, which is a focus of much modern cancer research.

The new study has found that the Grasp gene is significantly involved in maintaining the proper function of p53. When "Grasp" is not being adequately expressed, the p53 protein that has entered the cell nucleus to either repair or destroy the cell comes back out of the nucleus before its work is finished.

"It appears that a primary function of Grasp is to form sort of a halo around the nucleus of a damaged skin cell, and act as kind of a plug to keep the p53 cell inside the nucleus until its work is done," one of the lead authors of this study Mark Leid said.

"A drug that could enhance Grasp function might also help enhance the p53 function, and give us a different way to keep this important tumour suppressor working the way that it is supposed to," the researcher added.

The study was published in the journal Photochemical and Photobiological Sciences.

In a worrying trend noted by oncologists, lung cancer is increasing rapidly among Indian women. The foremost reason, much against popular perception, is not smoking but environmental pollution.

India has just slipped 32 ranks in the global Environment Performance Index (EPI) to a low of 155, and capital Delhi has earned the dubious tag of being the world's most polluted city.

While the fact that pollution harms health is known, that environmental pollution is now the main reason behind increasing cases of lung cancer should make people, and especially the government, sit up and do something to put a cap on the smoke and other pollutants.

According to the National Cancer Registry of the Indian Council of Medical Research (ICMR), in 1998 in Delhi, the ratio of lung cancer cases in men was nine per 100,000 males and was negligible in women. In 2008 the figure for men was still nine per 100,000, while for women, it was three per 100,000.

"So, while in 1998, lung cancer was negligible in women and was not one of the top 10 cancers affecting females, in 2008 the ratio between men and women became 3:1. In our experience in the clinic too, we have seen a rise in the number of women affected by lung cancer. Most of these women are from metro cities and are non-smokers...they are not even passive smokers," A.K. Anand, chief, Radiation Oncology at Max Hospital, told IANS.

The incidence of lung cancer, Anand further said, is the highest among women in the 45-55 age group.

"If you see the numbers in rural areas, there has been no change in the incidence of such cases. Vehicular pollution and industrial pollution are, therefore, the foremost cause behind the rising number of lung cancer cases," he added.

While the Cancer Registry data may indicate that there has been no rise in similar cases among men, doctors say that there has been a proportionate rise in head and neck cancer among men during this time. "Maybe because there has also been a rise in throat cancer, tongue cancer during this time, incidence of lung cancer has not shown any change in men over that period," Anand said.

Preeti Jain, consultant Oncology surgeon at Columbia Asia Hospital, further said that harm by vehicular and environmental pollution starts early. "Pollution is definitely a big factor in the rising number of respiratory ailments and now in lung cancer cases. Fine particulate matter in the air that lodges itself in the lungs causes harm over time, and damage starts early," Jain told IANS. Smoking, even passive smoking, she added, are the next two factors.

The comparative study of 178 countries on nine environmental parameters by US-based Yale University shows that Delhi has the highest particulate matter (PM) reading at 2.5, beating Chinese capital Beijing. The high PM caused by high vehicle density and industrial emissions is the reason behind the dense fog engulfing the city in the winter over the past few years, wreaking havoc on one's health.

At a personal level, doctors say that using masks, especially while on the go, could offer some respite, especially to children and the elderly who are among the most vulnerable lot.

"But for actual change to take place, people must raise their voices against pollution and the government must take steps like asking industries to shift out of cities," Anand said. Encouragement of car pooling, especially while going to work, can also have an impact, reducing traffic congestion and vehicular pollution. So will the improvement of public transport do, not just in Delhi but across the country.

At the end, doctors yet again harp on the importance of awareness about cancer in order to manage it successfully. "One of the reasons why you hear so often about cancer cases is because people are becoming aware and are getting diagnosed early, and that is very important. We have better diagnostic techniques and chemotherapeutic drugs today; so screening and diagnosing early means we can conserve the organ and the person can lead a good quality of life. So awareness is very important," said oncologist Rajesh Majumdar.

Researchers have identified abnormal expression of genes, resulting from DNA relaxation, that can be detected in the brain and blood of Alzheimer's patients.

The protein tau is involved in a number of neurodegenerative disorders, including Alzheimer's disease.

Previous studies have implicated DNA damage as a cause of neuron, or cell, death in Alzheimer's patients.

Given that DNA damage can change the structure of DNA within cells, the researchers led by Bess Frost examined changes in DNA structure in tau-induced neurodegeneration.

They used transgenic flies and mice expressing human tau to show that DNA is more relaxed in tauopathy.

They then identified that the relaxation of tightly wound DNA and resulting abnormal gene expression are central events that cause neurons to die in Alzheimer's disease.

"Our work suggests that drugs that modify DNA structure may be beneficial for treating Alzheimer's Disease," they wrote.

The study is published in the journal Nature Neuroscience.