Friday, 2 August 2013

Researchers Found a switch to turn off cancer of testis and ovary

Malignant Germ Cell Tumors (GCT) are malignant tumors that are formed by immature cells that begin in the reproductive cells of the testes or ovaries. These germ cells travel into the pelvis as ovarian cells or into the scrotal sac as testicular cells. These cells metastasize to other parts of the body and most commonly spread to the lungs, liver, lymph nodes, and central nervous system. Adult germ cell tumors are usually in the testes or ovaries.

Although many patients do well after treatment, current chemotherapy treatments can have severe long-term side effects, including hearing loss and damage to the kidneys, lungs and bone marrow. For some patients, outcomes remain poor and testicular cancer continues to be a leading cause of death in young men.

Researchers from Cambridge have discovered a molecular "switch" that can turn off a highly virulent cancer of the testis and the ovary.

The scientists found that all malignant germ cell tumors contain large amounts of a protein called LIN28. This results in too little of a family of tiny regulator molecules called let-7. In turn, low levels of let-7 cause too much of numerous cancer-promoting proteins in cells.

Importantly, the cancer-promoting proteins include LIN28 itself, so there is a vicious cycle that acts as an `on` switch to promote malignancy.

The researchers have likened these changes to a `cascade effect`, extending down from the large amounts of LIN28 to affect many properties of the cancer cells.

The researchers also discovered that by reducing amounts of the protein LIN28, or by directly increasing amounts of let-7, it is possible to reverse the vicious cycle.

Both ways reduced levels of the cancer-promoting proteins and inhibited cell growth. Because the level of LIN28 itself goes down, the effects are reinforced and act as an `off` switch to reduce cancerous behaviour.

The switch effect is present in all malignant germ cell tumours, whether they occur in males or females, young or old. Such a fundamental abnormality makes an excellent new target for treating these tumours.

Thursday, 1 August 2013

A Glass of Milk After Eating Sugary Cereals May Prevent Cavities

Tooth decay is the process that results in a cavity (dental caries). It occurs when bacteria in your mouth make acids that eat away at a tooth. If not treated, tooth decay can cause pain, infection, and tooth loss.

It is known that, to avoid cavities eating high sugar and/or high acid foods (cookies, candy, soda) between meals should be avoided. According to a new research at the University of Illinois at Chicago College of Dentistry, a glass of milk after eating sugary meal may reduces plaque acid levels and may prevent damage to tooth enamel that leads to cavities.

For their study reseachers, involved 20 adults eating 20 grams of dry Froot Loops cereal, then drinking different beverages -- whole milk, 100 percent apple juice, or tap water.

They measured plaque pH or acidity with a touch microelectrode between the premolar teeth before eating, two and five minutes after eating and then two to 30 minutes after drinking a liquid.

They found that pH in plaque dropped rapidly after consuming cereal alone, and remained acidic at pH 5.83 at 30 minutes.Participants who drank milk after eating sugary cereal showed the highest pH rise, from 5.75 to 6.48 at 30 minutes. Those who drank apple juice remained at pH 5.84 at 30 minutes, while water raised the pH to 6.02.

Milk, with a pH ranging from 6.4 to 6.7, is considered to be a functional food that fights cavities because it promotes tooth remineralization and inhibits the growth of plaque.

Most consumers think that since milk is considered to be cavity-fighting, acid production by plaque bacteria can be minimized by mixing it with cereal. However, in an unpublished study in the lab, it was discovered that the combination of Froot Loops and milk became syrupy. Eating cereal combined with milk lowered plaque pH to levels similar to that obtained after rinsing with a 10 percent sugar solution.

The research is published in the July issue of the Journal of the American Dental Association.

Wednesday, 31 July 2013

Stem cells in urine easy to isolate, have potential for numerous therapies

In mammals, there are two broad types of stem cells: embryonic stem cell, which are isolated from the inner cell mass of blastocyst, and adult stem cell, which are found in various tissues. Now researchers at Wake Forest Baptist Medical Center’s Institute for Regenerative Medicine and colleagues have identified stem cells in urine that can be directed to become multiple cell types.

These cells can be obtained through a simple, non-invasive low-cost approach that avoids surgical procedures. It can be obtained just by collecting urine sample.

Researchers successfully directed stem cells from urine to become bladder-type cells, such as smooth muscle and urothelial, the cells that line the bladder. But the urine-derived cells could also form bone, cartilage, fat, skeletal muscle, nerve, and endothelial cells, which line blood vessels. The multipotency of the cells suggests their use in a variety of therapies.

To use a patient's own stem cells for therapy is considered advantageous because they do not induce immune responses or rejection. However, because tissue-specific cells are a very small sub-population of cells, they can be difficult to isolate from organs and tissues.

The team first identified the cells, which are a small subset of the many cells found in urine, in 2006. The current research builds on earlier studies by confirming the multipotency of the cells. In addition, the research found that unlike iPS cells or embryonic stem cells, the urine derived-stem cells do not form tumors when implanted in the body, indicating they may be safe for use in patients.

For their research they collected urine samples from 17 healthy individuals ranging in age from 5 to 75 years. Isolating the cells from urine involves minimal processing, according to the authors. Next, they evaluated the cells' ability to become multiple cell types.

Importantly, the cells differentiated into the three tissue layers (endoderm, ectoderm and mesoderm) that are a hallmark of true stem cells and also differentiated into the specific cell types mentioned earlier.

Next, the researchers placed cells that had been differentiated into smooth muscle and urothelial cells onto scaffolds made of pig intestine. When implanted in mice for one month, the cells formed multi-layer, tissue-like structures.

The urine-derived stem cells have markers of mesenchymal cells, which are adult stem cells from connective tissue such as bone marrow. They also have markers for pericytes, a subset of mesenchymal cells found in small blood vessels.

Researchers suspect that the cells originate from the upper urinary tract, including the kidney. Female study participants who had received kidney transplants from male donors were found to have the y chromosome in their urine-derived stem cells, suggesting the kidney as the source of the cells.

The research is published online in the journal Stem Cells.

Monday, 29 July 2013

DNA mutation breakthrough could help treat TB, cancer

A DNA mutation is any change that occurs in the DNA. These changes can be beneficial to, have some effect on, or be seriously detrimental to an organism. Each cell depends on thousands of proteins to do their jobs in the right places at the right times. Sometimes, mutations prevent one or more of these proteins from working properly. By changing a gene’s instructions for making a protein, a mutation can cause the protein to malfunction or to be missing entirely. When a mutation alters a protein that plays a critical role in the body, it can disrupt normal development or cause a medical condition.

Researchers have developed a new method to that has the capability of looking at a specific segment of DNA and point out a single mutation, which could help diagnose and treat diseases like cancer and tuberculosis.These small changes can be the root of a disease or the reason some infectious diseases resist certain antibiotics.

For example, tuberculosis -- a disease that's known to have drug-resistant strains. Its resistance to antibiotics often is due to a small number of mutations in a specific gene. If a person with tuberculosis isn't responding to treatment, it's likely because there is a mutation.

The new method has improved on previous approaches because their solution doesn`t require any complicated reactions or added enzymes, it just uses DNA. Their method is robust to changes in temperature and other environmental variables, making it well-suited for diagnostic applications in low-resource settings.

Lead author Georg Seelig, a University of Washington assistant professor of electrical engineering and of computer science and engineering along with David Zhang of Rice University and Sherry Chen, a UW doctoral student in electrical engineering, designed probes that can pick out mutations in a single base pair in a target stretch of DNA.

The probes allow researchers to look in much more detail for variations in long sequences - up to 200 base pairs - while current methods can detect mutations in stretches of up to only 20 bp.

In this method, testing probes are designed to bind with a sequence of DNA that is suspected of having a mutation. The researchers do this by creating a complimentary sequence of DNA to the double-helix strand in question. Then, they allow molecules containing both sequences to mix in a test tube in salt water, where they naturally will match up to one another if the base pairs are intact. Unlike previous technologies, the probe molecule checks both strands of the target double helix for mutations rather than just one, which explains the increased specificity.

The probe is engineered to emit a fluorescent glow if there`s a perfect match between it and the target. If it doesn`t illuminate, that means the strands didn`t match and there was in fact a mutation in the target strand of DNA.

The findings have been published online in the journal Nature Chemistry.

Saturday, 27 July 2013

Biosensor tattoo tells athletes when they're about to hit the wall

Hitting the wall is a term that athletes use to describe the condition where they physically run out of steam.This generally happens when sustained vigorous physical activity causes lactate to build up in the body. When lactate levels get too high, fatigue results. By monitoring those levels, however, athletes can ease back on the activity, allowing their lactate levels to drop before reaching that point of no return by regular blood test which is not practical during prolonged exercises.
But now a team led by the University of California, San Diego’s Prof. Joseph Wang created a flexible electrochemical biosensor tattoo that tell athelete's when they're about to hit the wall. It tells athletes when lactate levels in their body are rising, offering an early warning that the energy stores in their muscles are running low. It is applied to the skin, that temporary-transfer sensor continuously measures lactate levels in the athlete’s sweat. 

It contains an enzyme that oxidises lactate to release electrons. These electrons then generate a current through the sensor's thin and flexible electronics: the more lactate is oxidised, the larger the current. A small device attached to the tattoo measures the current to provide real-time information on lactate levels.

It was tested on 10 subjects who were working out on an exercise bike and it was able to accurately indicate the rise in their lactate levels.

In future, those readings could be transmitted by bluetooth to a cellphone, says Wang.

The technology could be used not only in the training and performance tracking of athletes, but also for soldiers and other people who are required to perform intense physical activity.

Friday, 26 July 2013

A Study Finds - Women's Height Linked to Cancer Risk

According to a new research taller postmenopausal woman have greater her risk for developing cancer. Researchers found height is linked to cancers of the breast, colon, endometrium, kidney, ovary, rectum, and thyroid, as well as to multiple myeloma and melanoma.

Furthermore, researchers were surprised at the number of cancer sites that were positively associated with height than were associated with numerous other factors linked to cancer, such as body mass index [BMI].

Senior study author Dr. Thomas Rohan, chair and professor of epidemiology and population health at Albert Einstein College of Medicine in New York City, told that, they didn't find much difference in heavy or lighter women, so it’s a pretty consistent association right across the spectrum.

They studied for 12 years on around 20,928 postmenopausal women. They found that for every 10-centimeter (3.94 inches) increase in height, there was a 13 percent increase in risk of developing any cancer, for example, a woman who was 5 feet 10 inches tall would have a 13 percent higher risk for cancer than a woman who was approximately 5 feet 6 inches tall. 

Some cancer were more strongly associated with height than other. Among specific cancers, there was a 13 percent to 17 percent increase in the risk of getting melanoma and cancers of the breast, ovary, endometrium, and colon. There was a 23 percent to 29 percent increase in the risk of developing cancers of the kidney, rectum, thyroid, and blood.

Of the 19 cancers studied, none showed a negative association with height.

Researchers said that some genetic variations associated with height are also linked to cancer risk. They also said that another potential explanation may be related to environmental factors, such as childhood nutrition. Increased energy intake during childhood is thought to influence adult height and may also impact certain systems in the body. Researchers need to better understand the link exists.

Researchers will continue to explore the link between height and cancer, as they search for some of the underlying biological mechanisms that may be responsible for the correlation.

The study was published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.

Thursday, 25 July 2013

Researchers Developed a Way That Makes You Invisible to Mosquitoes

Several methods are used to limit exposure to mosquitoes and protect from bites when mosquitoes are unavoidable. But now researchers, including an Indian-origin scientist, have developed the world's first lightweight patch that can make people 'invisible' to pesky mosquitoes and could prove key in the battle against mosquito borne diseases.

That patch is named as 'KiteTM Mosquito patch.' It is is a 2-by-2-inch adhesive square that makes people virtually undetectable by mosquitoes for up to 48 hours. 

The patch is designed on basis of the research of University of California, Riverside in 2011, which states that mosquitoes primary way to sniff out human prey is their ability to detect carbon dioxide.

The patch, sticks to clothing, using non-toxic compounds that block mosquitoes' ability to detect carbon dioxide. It can be used by people of all ages , including infants and pregnant mothers. 

The initial research was performed in the laboratory of Anandasankar Ray, an associate professor of entomology , and was featured in the journal Nature. 

Ray's lab identified volatile odour molecules that can impair, if not completely disrupt , mosquitoes' carbon dioxide detection machinery. 

Kite's technology is the culmination of years of development work on a class of odour molecules, all of which are non-toxic compounds approved for human consumption by the US Food and Drug Administration. "The Kite Mosquito Patch isn't just another mosquito product, but a powerful alternative to most products on the market, enabling people to live normal lives with a new level of protection against contracting mosquito-borne diseases," said Michelle Brown, the chief scientist and vice president of Olfactor Laboratories.