Mechanism of incorporation of newly synthesized myosin alkali light chain into myofibril

The present work was designed to study the incorporation of newly synthesized myosin alkali light chain [MLC] molecules into myofibris. cDNA of fast skeletal muscle type of MLC tagged with green fluorescence protein [LC3f-GFP] was transfected into cultured chicken cardiomyocytes, and the assembly of expressed LC3f-GFP was observed in living cells under a fluorescence microscope equipped with a cooled CCD camera. At 14-16 hours after transfection, LC3f-GFP was diffusely distributed in the cytoplasm of cardiomyocytes. In some cells, however, intense fluorescence spots of LC3f-GFP were found along myofibrils with a periodically of 1.2 micro m. Confocal microscopy of such cells, stained with rhodamine-labeled phalloidin, revealed the fluorescence spots of LC3f-GFP localized at both ends of A-bond. When these cells were further incubated, LC3f-GFP came to be localized at all levels of the A-bands by 26 hours after transfection. These results indicate that myosin filaments are not replaced with newly synthesized myosin molecules at once along their length, but molecules in filaments are replaced individually from their ends

Hypospermatogenesis and spermatozoa maturation arrest in rats induced by mobile phone radiation

To determine the morphological changes induced by mobile phone radiation in the testis of Wistar albino rats. Cohort study. Department of Physiology, College of Medicine, King Saud University, Riyadh, Saudi Arabia, from April 2007 to June 2008. Forty male Wistar albino rats were divided in three groups. First group of eight served as the control. The second group [group B, n=16] was exposed to mobile phone radiation for 30 minutes/ day and the third group [group C, n=16] was exposed to mobile phone radiation for 60 minutes/day for a total period of 3 months. Morphological changes in the testes induced by mobile phone radiation for 60 minutes/day caused 18.75% hypospermatogenesis and 18.75% maturation arrest in the testis of albino rats compared to matched controls. However, no abnormal findings were observed in albino rats that were exposed to mobile phone radiation for 30 minutes/day for a total period of 3 months. Long-term exposure to mobile phone radiation can cause hypospermatogenesis and maturation arrest in the spermatozoa in the testis of Wistar albino rats

Sternalis: a clinically important variation

Sternalis muscle is an anatomical variation that is considered as a dilemma for surgeons and radiologists whereas a matter of interest for anatomists. It is found occasionally in the human on the anterior aspect of the thorax, superficial to the pectoralis major muscle. During routine cadaveric dissection for undergraduate medical students, presence of sternalis muscle was detected in a 60 years old mate cadaver. This rare anomaly has puzzled radiologists and surgeons in confirming diagnosis, missing it completely or mistaking it for a tumor on mammography or CT scan as it may mimic a malignant mass lesion on the medial aspect of craniocaudal mammograms. A detailed description of this important variation is needed in the text books for radiologists and surgeons