Activation of brown adipose tissue in diet-induced thermogenesis is GC-C dependent.

Uroguanylin (UGN) is released from the intestine after a meal. When applied in brain ventricles, UGN increases expression of markers of thermogenesis in brown adipose tissue (BAT). Therefore, we determine the effects of its receptor, guanylate cyclase C (GC-C), on mouse interscapular BAT (iBAT) activity during diet-induced thermogenesis (DIT). The activation of iBAT after a meal is diminished in GC-C KO mice, decreased in female wild type (WT) mice, and abolished in old WT animals. The activation of iBAT after a meal is the highest in male WT animals which leads to an increase in GC-C expression in the hypothalamus, an increase in iBAT volume by aging, and induction of iBAT markers of thermogenesis. In contrast to iBAT activation after a meal, iBAT activation after a cold exposure could still exist in GC-C KO mice and it is significantly higher in female WT mice. The expression of GC-C in the proopiomelanocortin neurons of the arcuate nucleus of the hypothalamus but not in iBAT suggests central regulation of iBAT function. The iBAT activity during DIT has significantly reduced in old mice but an intranasal application of UGN leads to an increase in iBAT activity in a dose-dependent manner which is in strong negative correlation to glucose concentration in blood. This activation was not present in GC-C KO mice. Our results suggest the physiological role of GC-C on the BAT regulation and its importance in the regulation of glucose homeostasis and the development of new therapy for obesity and insulin resistance.

Detection of human papillomaviruses type 16, 18 and 33 in bronchial aspirates of lung carcinoma patients by polymerase chain reaction: a study of 84 cases in Croatia.

Besides its well-known role in cervical carcinoma, HPV is also suggested to be involved in lung cancer development. A number of authors have been investigating the presence of HPV in histological materials. We used routine bronchial aspirates from 84 patients with lung carcinoma for DNA extraction and then performed polymerase chain reaction for high-risk HPV types 16, 18 and 33. The results were compared to those obtained from buccal and eyelid mucosa. Only three patients were positive for HPV in bronchial aspirates: one for HPV 16 type, one for HPV 18 type, and one for HPV 33. Our data indicated the low prevalence of HPV in patients with lung carcinomas in Croatia, therefore it seems unlikely that HPV contributes to the development of lung carcinomas in this region.

PCR-quality DNA isolation from human bronchial aspirates and buccal and eyelid swabs by a simple procedure based on alkaline lysis.

There are only a few systematic reports about DNA extraction from routine diagnostic cytological specimens. An inevitable drawback of such techniques is increased spending of time and funds required for obligatory DNA purification. To implement a simple protocol for human DNA isolation from cytological specimens related to lung cancer, bronchial aspirates together with samples collected by swabbing of the inner cheek and eyelid were used. By combining alkaline and temperature lyses it was possible to isolate DNA solution ready for PCR in less than an hour. Testing the method used for amplification of sex chromatin gene fragments showed that it is highly efficient. The presented protocol preserves high-quality DNA that is suitable for PCR-based assays.