Galactocerebroside mediates Ca2+ signaling in cultured glioma cells.

Expression of galactocerebroside (GalC) was detected in human glioma cell line (U-87 MG). Exposure of cells to antibody against GalC and fluoresceinated second antibody showed intense fluorescence on the plasma membrane. Possible involvement of GalC in receptor-mediated transmembrane signaling was explored in this cell line. Antibodies raised against GalC were used as ligands. Binding of anti-GalC to these cells caused a transient increase in intracellular free calcium ([Ca2+]i). The response was observed both in the presence and absence of extracellular calcium demonstrating that the rise in [Ca2+]i induced by anti-GalC was due to an influx of Ca2+ through plasma membrane as well as the release of Ca2+ from intracellular pools. Ca2+ influx was blocked by verapamil, indicating that influx is mediated by voltage-sensitive channels. Our results suggest that GalC can play a role in transmembrane signaling by modulation of voltage-sensitive Ca2+ channels.     

Drug compliance among self-motivated leprosy patients

Regularity of DDS intake among 366 leprosy patients attending our out patient department voluntarily was assessed by urine spot test. It was found that only 54.6% of them had taken their last dose of drug within the previous three days. Those who kept their appointment showed better compliance than those who did not. Urinary DDS positivity was found to be unrelated to sex, occupation or the type of the disease. In the younger age group the compliance was low, as also among the patients coming from nearby places as compared to those who were residing in far off districts.     

Cytogenetics in head and neck cancer

Cytogenetics or the study of chromosomes has been an important tool in oncology. It localizes the abnormality on a particular chromosome segment as such but, the molecular analysis on the other hand focuses the exact gene of interest. Hence both are complimentary. Classical cytogenetics in combination with recent molecular techniques has given rise to various molecular cytogenetic analytical techniques such as florescent in-situ hybridization (FISH), spectral karyotyping (SKY) and comparative genomic hybridization (CGH). The role of telomeres and its concerned enzyme telomerase is important in carcinogenesis. This article summarizes the various cytogenetic techniques and presents an overall view of the importance of cytogenetcs in head and neck cancer.     

Angiomyxoma diagnosed in a man presenting for abdominal lipectomy

Aggressive angiomyxoma is a rare tumour that is locally infiltrative but nonmetastasizing. It occurs nearly exclusively in adult women of childbearing age and almost always arises in the perineum and pelvic area. A case of angiomyxoma occurring in a middle-aged, morbidly obese man is reported. The clinical presentation was one of progressing scrotal edema and enlargement with subsequent development of scrotal abscesses, requiring several incisions and drainages as well as oral and intravenous antibiotics. His symptoms and body habitus left him in a significantly debilitated state, prompting him to seek treatment for his conditions. He initially presented for abdominal lipectomy. However, due to the chronic scrotal infections and enlargement, scrotectomy was recommended before any other surgical procedures. A scrotectomy was performed by the urology service. Pathological diagnosis of the excised tumour was an aggressive angiomyxoma. Given the rarity of this tumour, especially in males, the proper diagnosis and treatment of angiomyxoma is still being investigated. With this in mind, the physical signs and symptoms that characterize this condition are presented and treatment options are reviewed.     

Selective sensitivity of synaptosomal membrane function to cerebral cortical hypoxia in newborn piglets

The effect of hypoxia on the structure and function of the synaptosomal membranes and myelin fraction (glial cells, neuronal cell bodies and axonal membranes) was investigated by measuring Na⁺,K⁺-ATPase activity and levels of lipid peroxidation products in cerebral cortical synaptosomal membranes and myelin fractions obtained from newborn piglets. Hypoxic hypoxia was induced and cerebral hypoxia was documented as a decrease in the ratio of phosphocreatine to inorganic phosphate (PCr/Oi) using³¹P-NMR spectroscopy. PCr/Pi decreased from baseline of2.93 ± 0.76to0.61 ± 0.36 during hypoxia. The synaptosomal membrane Na⁺,K⁺-ATPase activity decreased from a control value of56.6 ± 3.7to40.4 ± 6.0 μgmol Pi/mg protein/h during hypoxia. The level of conjugated dienes increased from zero (reference value) to4.5 ± 2.7 nmol/mg lipid and the level of fluorescent compounds increased from23.5 ± 2.2to92.6 ± 46.4 ng quinine sulfate/mg lipid in the synaptosomal membranes during hypoxia. No change in myelin fraction Na⁺,K⁺-ATPase activity or levels of lipid peroxidation products were noted. These data indicate that sunaptosomal membranes, rich in polyunsaturated fatty acids, are more susceptible to oxygen free radical mediated lipid peroxidative damage during hypoxia.     

Glucosamine-resistant mutations in yeast affecting the glucose repression sensitivity of electron transport enzymes

Summary We have isolated two mutant strains, GSA^r-4 and GSA^r-5, which are able to grow on lactate in the presence of D-glucosamine. The glucosamine-resistant phenotype results from the cooperative effects of mutations in three loci, GAR1, GAR2 and GAR3. Both glucosamine resistant mutant strains were doubly mutant at gar1 gar2 (GSA^r-4) or gar1 gar3 (GSA^r-5). The mutants were also shown to exhibit glucose repression insensitive synthesis of NADH-cytochrome c reductase and cytochrome c oxidase. Glucose-repressible synthesis of the following enzymes was seen: succinic dehydrogenase, succinic: cytochrome c reductase, maltase (PNPGase), galactokinase, -galactokinase. The glucose-repression insensitivity segregates in association with the glucosamine resistance.     

Sertoli-Leydig cell tumor of ovary with heterologous element: a case report

Sertoli-Leydig cell tumors are uncommon tumors of ovary accounting for about 1% of sex cord stromal tumors. They constitute between 0.1% to 0.5% of all the primary ovarian neoplasms. The majority of reported cases are moderately or poorly differentiated combined Sertoli-Leydig cell tumors. A rare case of Sertoli-Leydig cell tumor with heterologous element in a 14 year girl is described. The heterologous component comprised smooth muscle, an uncommon element, that was seen in 60 to 70% of the tumor area. The epithelial element of the tumor consisted of solid, tubular and foci of retiform pattern. Both these features imply a poor prognosis.