the University of Pennsylvania
Scientists have found a new wrinkle in the developmental biology dogma that cell differentiation occurs irreversibly as stem cells give rise to increasingly specialized types of offspring cells. The researchers have shown that certain mouse cells retain an ability to oscillate between very distinct blood cell types ? B-cells and macrophages ? long after what has been commonly regarded as the point of no return.
While type 1 Neurofibromatosis (NF1) is primarily known to cause tumors of the nervous system, scientists were puzzled as to why patients with NF1 are also prone to cardiovascular problems such as hypertension and congenital heart disease. Researchers from the University of Pennsylvania School of Medicine have solved this particular part of the puzzle by showing how the Nf1 gene - which is mutated in those suffering from Neurofibromatosis - is also essential in endothelial cells, the cells that make up blood vessels.
Rearrangements of the mixed lineage leukemia gene, MLL, are associated with aggressive leukemias in both children and adults. Researchers at the University of Pennsylvania School of Medicine have found that one portion of the MLL protein is an enzyme that "edits" the so-called histone code, a series of modifications to proteins associated with DNA that influence how and when certain genes are turned on and off. Their findings are presented in the November issue of Molecular Cell.
Scientists have successfully restored sperm production in once-infertile mice by transplanting specialized cells that are critical to sperm development. The research, reported on the Web site of the journal Biology of Reproduction, may give scientists a better understanding of how Sertoli cells ? which surround spermatogenic stem cells ? nourish sperm production and the survival of stem cells.
As is people with schizophrenia didn't have enough to worry about a new study finds that schizophrenic patients who take antipsychotic drugs are more likely to have experienced cardiac arrest or ventricular arrhythmia than non-schizophrenic patients. While previous research has linked several of these drugs to irregular electrocardiogram results, the researchers used billing data to uncover a link between the drugs and cardiac arrest.
A team of researchers from Pennsylvania say an electronic nose - a relatively new version of a sensor previously used in the food, wine and perfume industries - can quickly and accurately diagnose pneumonia in critically ill, mechanically ventilated patients.
Smokers with a specific genetic variant may be more vulnerable to cigarette cravings and relapse when trying to quit smoking, a study has found. This study also shows that the anti-depressant drug bupropion may lessen these effects, especially among females.
