Decolorization of triphenylmethane dyes by the bird's nest fungus Cyathus bulleri

Decolorization of three triphenylmethane dyes by three bird's nest fungi—Cyathus bulleri, C. stercoreus, and C. striatus—was studied. Cyathus bulleri was found to be the most efficient in decolorization as demonstrated by the disappearance of the dyes from cultures, monitored by decreases in absorbance. Growth of the Cyathus spp. was not affected by the presence of dyes in the cultures. Decolorization of dyes was also observed with extracellular culture filtrates, indicating exocellular activity. Laccase activity, tested in replicate cultures, was found to be maximum during the decolorization period. Nitrogen in the medium had no effect on decolorization.     

Studies on triacylglycerol ester hydrolase from bat adipose tissue

Triacylglycerol ester hydrolase was isolated from bat adipose tissue and characterized. The partially purified enzyme had pH optimum of 8.6 and a K_m value of 0.6 mM. The enzyme was denaturated upon freezing and thawing, which was prevented by 25% glycerol. The enzyme was activated by EDTA and NaCl, while it was inhibited by serum and bovine serum albumin. Heparin, sodium fluoride and diisopropyl fluorophosphate had no effect on triacylglycerol ester hydrolase activity. It hydrolyzed triglycerides partially. Triacylglycerol ester hydrolase lost its activity during delipidation but it was reactivated by endogenous lipids and phospholipids, viz. phosphatidyl ethanolamine, phosphatidyl choline and sphingomyelin. The enzyme shows kinetic properties altogether different from lipoprotein lipase and hormone sensitive lipase     

Mechanisms of acquired resistance in mouse typhoid

A polyvalent radiovaccine of Salmonella was shown to induce protective immunity in mice. The results revealed that the immunized mice progressively eliminated the challenged organisms and no Salmonella could be isolated after a period of 21 days. In contrast, Salmonella grew in the control mice and reached levels of 10(8) to 10(9) cfu/spleen resulting in the death of animals. Sera from both control and the immune mice were found to lack bactericidal activity. It was further observed that the vaccine induced delayed type of hypersensitivity and that antibody production as measured by bacterial agglutination and passive hemagglutination were low in response to the vaccine. However, the phagocytic activity of the reticuloendothelial system was considerably enhanced by the immunization. The results of experiments with immunosuppressed mice suggested the role of thymus derived (T) lymphocytes in the protection.     

Ion microscopic imaging of calcium during 1,25-dihydroxyvitamin D-mediated intestinal absorption

A combination of ion microscopic and conventional radionuclide techniques was employed to investigate the temporal-spatial dynamics of 1,25-dihydroxyvitamin D₃ [1,25(OH)₂D₃]-stimulated intestinal calcium (Ca) absorption. At varying times following the administration of a single intravenous dose of 1,25(OH)₂D₃, to vitamin D-deficient chicks, transepithelial transport and tissue retention of Ca were quantitated in vivo, using the ligated duodenal loop technique and⁴⁷Ca as the tracer. The localization of Ca in the intestinal tissue during absorption was monitored by ion microscopy, using the stable Ca isotope,⁴⁴Ca, as the absorbed species. There was little transepithelial absorption of Ca in the vitamin D-deficient animals despite a substantial tissue accumulation of luminally derived Ca, the latter localizing predominantly in the brush border region of the enterocyte, as shown by the⁴⁴Ca-ion microscopic images. The early (30 min-1 h) response to 1,25(OH)₂D₃ was an increased tissue uptake of luminal⁴⁷Ca, which also primarily associated with the brush border region, again as shown by ion microscopy. At 2–4 h after the 1,25(OH)₂)D₃ dose, there was a progressive redistribution of Ca from the brush border region throughout the cytoplasm and into the lamina propria. At 8–16 h,⁴⁷Ca absorption was maximal and⁴⁴Ca was sparsely distributed in the intestinal tissue.⁴⁷Ca absorption gradually declined and reached pre-dose levels by 72 h. At this time, tissue⁴⁴Ca was again largely limited to the brush border region. These results provide support for the multiple actions of 1,25(OH)₂D₃ on the intestinal Ca absorption