Body

Cell cultures are homogeneous. Human tumors are not. A University of Colorado Cancer Center study recently published in the journal Breast Cancer Research and Treatment reports the development of human-derived estrogen-positive (ER+) breast cancer models that retain their heterogeneity, allowing researchers to more accurately test drugs for this disease.

Philadelphia, PA, August 6, 2012 – Individuals with mutations in BRCA1 and BRCA2 genes have a significantly higher risk of developing breast and ovarian cancers. Families at risk have been seeking genetic testing and counseling based on their mutation carrier status, but the standard method of direct sequencing is labor-intensive, costly, and it only targets a part of the BRCA1 and BRCA2 genes. A group of Canadian scientists has developed a new sequencing approach to provide a more effective method of BRCA1/2 mutational analysis.

There is a popular belief that sexual orientation can be revealed by pupil dilation to attractive people, yet until now there was no scientific evidence. For the first time, researchers at Cornell University used a specialized infrared lens to measure pupillary changes to participants watching erotic videos. Pupils were highly telling: they widened most to videos of people who participants found attractive, thereby revealing where they were on the sexual spectrum from heterosexual to homosexual.

Researchers at the University of California, San Diego School of Medicine say neutrophils, an abundant type of white blood cell typically tasked with attacking bacteria and other foreign invaders, also plays an unexpected role in mediating insulin resistance – the central characteristic of type 2 diabetes, which afflicts an estimated 26 million Americans.

It's a longstanding question in biology: How do cells know when to progress through the cell cycle?

In simple organisms such as yeast, cells divide once they reach a specific size. However, determining if this holds true for mammalian cells has been difficult, in part because there has been no good way to measure mammalian cell growth over time.

Genetic variability revealed in malaria genomes newly sequenced by two multi-national research teams points to new challenges in efforts to eradicate the parasite, but also offers a clearer and more detailed picture of its genetic composition, providing an initial roadmap in the development of pharmaceuticals and vaccines to combat malaria.

Developing resistance to chemotherapy is a nearly universal, ultimately lethal consequence for cancer patients with solid tumors – such as those of the breast, prostate, lung and colon – that have metastasized, or spread, throughout the body. A team of scientists led by Fred Hutchinson Cancer Research Center has discovered a key factor that drives this drug resistance – information that ultimately may be used to improve the effectiveness of therapy and buy precious time for patients with advanced cancer. They describe their findings online Aug.

Researchers have found that a bacterium that emerged centuries ago in Europe has now been spreading globally into countries undergoing rapid development and industrialization. Unlike other diarrheal diseases, this one is unlikely to be resolved by providing access to clean water.

Columbia University Medical Center (CUMC) researchers have identified a mechanism that can give energy-storing white fat some of the beneficial characteristics of energy-burning brown fat. The findings, based on studies of mice and of human fat tissue, could lead to new strategies for treating obesity and type 2 diabetes. The study was published today in the online edition of the journal Cell.

Scientists from the Florida campus of The Scripps Research Institute have identified a protein that impairs the development and maintenance of lymphoma (cancer of the lymph nodes), but is repressed during the initial stages of the disease, allowing for rapid tumor growth.

Genetics clearly plays a role in cancer development and progression, but the reason that a certain mutation leads to one cancer and not another is less clear. In addition, no links have been found between any cancer and a type of genetic change called copy-number variants, or CNVs. Now, a new study published in The American Journal of Human Genetics identifies CNVs associated with testicular cancer risk, but not with the risk of breast or colon cancer.

Stem cells are special. Nestled in muscle and skin, organ and bone, they bide their time over years or decades until called to replace damaged or lost tissue. One secret to their longevity is an enzyme called telomerase, which stills the relentless ticking of the molecular clock that limits the life span of other cells.

The composition of microbes in the gut changes dramatically during pregnancy, according to a study published in Cell. Although these changes are associated with metabolic disease under most circumstances, they could be beneficial in pregnant women.

Scientists are beginning to understand one of life's enduring mysteries - why women live, on average, longer than men.

Published today in Current Biology, research led by Monash University, describes how mutations to the DNA of the mitochondria can account for differences in the life expectancy of males and females. Mitochondria, which exist in almost all animal cells, are vital for life because they convert our food into the energy that powers the body.

One of the most invasive species on the planet is able to source food from the land as well as its usual food sources in the water, research from Queen Mary, University of London has found.

Scientists analysed the behaviour of red swamp crayfish in Kenya's Lake Naivasha and found that when the water level of the lake was low, the crayfish found additional food sources on land. The study was published in the journal PLoS ONE today (3 August 2012).