PubMed Health⌕ Search

Biomedical subjects

S T Wu

Publications and source records attributed to S T Wu.

59 records · Page 4Linked to original sources
PubMedDate not supplied

Glycolysis in heart failure: a 31P-NMR and surface fluorometry study.

Glycolysis is slow in the heart, especially in the cardiomyopathic heart. Glycolysis is partially rate-limited by phosphofructokinase (PFK), an enzyme which is inhibited by calcium (Ca2+)i and hydrogen ions (H+)i and activated by cAMP. (H+)i and (Ca2+)i are augmented in cardiomyopathy. With glucose as the only substrate (NADH)/(NAD) the phosphorylation potential and developed pressure were significantly lower, and concentrations of phosphomonoester sugars and hydrogen ions (H+)i were significantly higher in isolated cardiomyopathic hearts as compared to healthy hamster hearts. Pyruvate lowered diastolic (Ca2+)i in cardiomyopathic hamster hearts. With pyruvate as the substrate (NADH)/(NAD), the phosphorylation potential and developed pressure increased significantly and concentrations of phosphomonoester sugars (PME), (H+)i and diastolic (Ca2+)i decreased significantly in myopathic hamster hearts. The results suggest that late heart failure in the myopathic hamster is associated with calcium and/or hydrogen ion-induced inhibition of glycolysis.

Animals↗
PubMedDate not supplied

Influence of ischemia on [Ca2+]i transients following drug therapy in hearts from aortic constricted rats.

Intracellular calcium transients were studied prior, during and after 30 min of global ischemia in control and aortic constricted rat hearts, with and without acute treatment with verapamil. Calcium transients [Ca2+]i continued to occur in verapamil treated animals for 18-20 min following the onset of global ischemia, whereas untreated hearts demonstrated calcium transients for only 3-8 min following global ischemia. Following the onset of global ischemia calcium transients continued to occur even though there was no measurable developed pressure. When calcium transients occurred for shorter periods of time during global ischemia the rise in diastolic calcium was greater and recovery was less. Addition of bradykinin to the perfusate showed that an increase in diastolic [Ca2+]i was related to a decrease in amplitude of developed [Ca2+]i transients and a decrease in developed pressure, but not to a change in coronary flow.

Animals↗
PubMedDate not supplied

Aggressive angiomyxoma of the scrotum.

Aggressive angiomyxoma is a rare and nonmetastasizing soft tissue tumor of the pelvis and perineum and occurs almost exclusively in adult females. It infiltrates locally and has a high risk of local recurrence. Recommended treatment of the symptomatic patient is wide excision with tumor-free margins and close postoperative monitoring. Herein, a case of aggressive angiomyxoma in an adult male is described, which arose in the scrotum over 12 months. The tumor showed an intermediate signal on T1-weighted MRI images. Contrast-enhanced T1-weighted images showed good enhancement. Wide excision of the tumor was performed. The surgical specimen measured 7 x 5 x 5 cm in size and weighed 80 g. The tumor's surface was smooth and had a gelatinous cut surface. Grossly, it was encapsulated with a pleura-like membrane and had a finger-like projection. Microscopically, sections showed many walled vessels of various sizes, collagen fibrils, a loose myxoid background. and spindle stroma cells. MRI and CT showed the angiomatous and myxomatous nature of the tumor wall. To the authors' knowledge, this is the first report to describe MRI findings in scrotal angiomyxoma.

Adult↗
PubMedDate not supplied

Ultrastructure of infection, development and gametocyst formation of Ascogregarina taiwanensis (Apicomplexa: Lecudinidae) in its mosquito host, Aedes albopictus (Diptera: Culicidae).

The life history of the protozoan parasite Ascogregarina taiwanensis in mosquito larvae (Aedes albopictus, collected in southern Taiwan) was shown to consist of two consecutive stages--intracellular and extracellular. Light microscopy showed that most trophozoites moved into the Malpighian tubules and developed into giant trophozoites during the first day pupa. The locomotion may be associated with bristle-like ridges of the trophozoite. The stage for sexual reproduction, i.e., the gamete, was then formed by segmentation of the giant trophozoite and twisting off the anucleate extremities of the body. Sexual reproduction occurred via fertilization by fusion of two resulting gametes, presumably two opposed sexes. The fused gametes finally generate the formation of the gametocyst, within which oocysts develop by budding from the cytoplasmic mass. This type of sexual reproduction has not been reported previously in any gregarine protozoa. We here proposed it as a new hypothesis for further elucidation of the protozoan reproduction.

Aedes↗