Cancer inhibitor

A TopoisomeraseIB protein (green) is hindered in unwinding DNA loops by the cancer purchase cialis topotecan (red). The DNA polymerase protein (grey), a protein which duplicates DNA, is hindered by the DNA loops.

Credit: Delft University of Technology / Tremani


Researchers in Delft University of Technology's Kavli Institute of Nanoscience in The Netherlands have cast new light on the workings of the important cancer cialis topotecan. Little had been known about the underlying molecular mechanism, but the Delft scientists can now view the effects of the medicine live at the levelin of a single DNA molecule.

The medicine investigated, topotecan, interacts with an important protein (TopoIB), causing a (cancer) cell to malfunction. The TopoIB protein is responsible for the removal of loops from DNA, which arise amongst other things during cell division. The TopoIB protein binds to the DNA molecule, clamps around it and cuts one of the two DNA strands, after which it allows it to unwind and finally joins the broken ends together.

Until now it has been supposed that topotecan only causes the TopoIB protein to reside longer than normal on the DNA molecule, disturbing the cell division and damaging the (cancer) cell. But the Delft researchers have now discovered to their surprise that adding topotecan also dramatically impedes the unwinding and that DNA loops accumulate as a result. The accumulation of these DNA loops forms the basis for an alternative mechanism, and could help in the development of better cancer medicine.

PhD candidate Daniel Koster, Master's student Elisa Bot and researcher Nynke Dekker of the Molecular Biophysics group of the Kavli Institute of Nanoscience Delft have managed to unravel this mechanism in an extremely direct manner. In the laboratory they fixed a single DNA molecule between a glass plate and a magnetic sphere. With the help of two magnets they could both pull and twist the DNA molecule.

When they added TopoIB to a twisted piece of DNA, they saw that the loops were slowly removed. What is exceptional is that the action of one TopoIB enzyme on one DNA molecule could be observed live. In collaboration with St. Jude Children's Research Hospital Memphis (USA) the mechanism could also be observed in living yeast cells.

The research was published in the journal Nature (June 24). The lead author of the article, Daniel Koster, will receive his PhD at TU Delft partly on the results described in the article. The research is supported by the Foundation for Fundamental Research on Matter and the Netherlands Organisation for Scientific Research.

TU DElft - Delft Research Centres
_______________________________________________________
_______________________________________________________

Obesity Erectile Dysfunction - How to Stop it Today!

There are a lot of known causes of male erectile purchase cialis. Illnesses like diabetes and high blood pressure can cause this condition as does obesity. Obesity is a condition that is brought about by an unhealthy lifestyle characterized by overeating of fatty foods and an extreme lack of activity. A person who is obese is overweight and plump with body fat unevenly distributed throughout his body. It is not seldom that a person who is obese would also suffer from psychological distress brought about by feelings of confusion, depression, and anxiety. Obesity is a condition does not only bring about obesity erectile cialis, but also other chronic illnesses such as myocardial infraction, atherosclerosis, and kidney problems.

Obesity erectile dysfunction is caused primarily by lack of blood circulation in the penile area. This is usually brought about by excessive fat that builds up and blocks the blood vessels causing a decreased flow of blood through the veins in the penis. The lack of blood circulation also starves the organ of the necessary nourishment, hormones, and oxygen to stimulate erection. All these result from the excess fat that is not burned out by the body clogging the blood vessels and can be remedied by substantially limiting fat intake if not altogether banishing it from the diet temporarily or permanently.

Another cause for obesity erectile dysfunction is the inability of obese people to release nitric oxide due to epithelium damage. Nitric oxide is a necessary chemical that causes the penile muscles to relax and allow blood flow to enter and achieve erection. In people suffering from obesity erectile dysfunction, the epithelial layer of the heart that stimulates erection is unable to release nitric oxide because of excessive damage resulting from excessive insulin production for metabolizing bad cholesterol. This too can be stopped by controlling cholesterol intake and consequently insulin production of the body.

Treating obesity erectile dysfunction is best done through treating the root cause of the condition which is obesity. Diet and exercise are simple enough solutions to this condition. But much effort has to be exerted by one who is obese in sticking to a strict diet and exercise regimen to bring results. Eating food rich in vitamins and minerals necessary for stress-reduction and enhanced blood circulation can help put a stop to erectile dysfunction due to obesity. Vitamins C, E and B complex and zinc are essential minerals for cholesterol reduction, blood circulation stimulation, and energy and protein metabolism. Herbal medicines are also found to be effective in providing cure for erectile dysfunction. Gingko biloba and ginseng are among those herbal cures recommended for treatment of the condition. These natural ways of improving erectile dysfunction are recognized as the best way to deal with the condition as they have no side effects and are widely available.

Stopping the occurrence of obesity erectile dysfunction is something that is not difficult to do with right amounts of determination. Obesity erectile dysfunction, in fact, is the least of the health problems an obese person would have to find solutions for. Living healthy and eating healthy can result in a healthy sex life in the shortest time possible.