A novel zinc bis(thiosemicarbazone) complex for live cell imaging

Fluorescent zinc complexes have recently attracted a lot of interest owing to their vast applications in cellular imaging. We report the synthesis as well as physical, chemical and biological studies of a novel zinc glyoxalbis(4-methyl-4-phenyl-3-thiosemicarbazone), [Zn(GTSC)]₃, complex. As compared with the well-studied zinc biacetylbis(4-methyl-3-thiosemicarbazone), Zn(ATSM), complex, which was used as a reference, [Zn(GTSC)]₃ had 2.5-fold higher fluorescence. When cellular fluorescence was measured using flow cytometry, we observed that [Zn(GTSC)]₃ had 3.4-fold to 12-fold higher fluorescence than Zn(ATSM) in various cell lines (n = 9) of different tissue origin. Confocal fluorescence microscopy results showed that [Zn(GTSC)]₃ appeared to have a nuclear localization within 30 min of addition to MCF7 cells. Moreover, [Zn(GTSC)]₃ showed minimal cytotoxicity compared with Zn(ATSM), suggesting that [Zn(GTSC)]₃ may be less deleterious to cells when used as an imaging agent. Our data suggest that the novel [Zn(GTSC)]₃ complex can potentially serve as a biocompatible fluorescent imaging agent for live cells.     

Spatiotemporal patterns of macrophage migration inhibitory factor (Mif) expression in the mouse placenta

Background  

Macrophage migration inhibitory factor (MIF) has special pro-inflammatory roles, affecting the functions of macrophages and lymphocytes and counter-regulating the effects of glucocorticoids on the immune response. The conspicuous expression of MIF during human implantation and early embryonic development also suggests this factor acts in reproductive functions. The overall goal of this study was to evaluate Mif expression by trophoblast and embryo placental cells during mouse pregnancy.     

Disulfiram and Its Copper Chelate Attenuate Cisplatin-Induced Acute Nephrotoxicity in Rats Via Reduction of Oxidative Stress and Inflammation

Biological Trace Element Research - The use of cisplatin (CP) in chemotherapy of resistant cancers is limited due to its dose-dependent nephrotoxicity. Disulfiram (DSF), the aversion therapy for...     

Corneal morphogenesis in the Indian garden lizard,Calotes versicolor (agamidae)

The present study traces corneal morphogenesis in a reptile, the lizard Calotes versicolor, from the lens placode stage (stage 24) until hatching (stage 42), and in the adult. The corneal epithelium separates from the lens placode as a double layer of peridermal and basal cells and remains bilayered throughout development and in the adult. Between stages 32– and 33+, the corneal epithelium is apposed to the lens, and limbic mesodermal cells migrate between the basement membrane of the epithelium and the lens capsule to form a monolayered corneal endothelium. Soon thereafter a matrix of amorphous ground substance and fine collagen fibrils, the presumptive stroma, is seen between the epithelium and the endothelium. Just before stage 34 a new set of limbic mesodermal cells, the keratocytes, migrate into the presumptive stroma. Migrating limbic mesodermal cells, both endothelial cells and keratocytes, use the basement membrane of the epithelium as substratum. Keratocytes may form up to six cell layers at stage 37, but in the adult stroma they form only one or two cell layers. The keratocytes sysnthesize collagen, which aggregates as fibrils and fibers organized in lamellae. The lamellae become condensed as dense collagen layers subepithelially or become compactly organized into a feltwork structure in the rest of the stroma. The basement membrane of the endothelium is always thin. Thickness of the entire cornea increases up to stage 38 and decreases thereafter until stage 41. In the adult the cornea is again nearly as thick as at stage 38.     

Efficiency of HCl- and H2SO4- acidulated rock phosphates for rice (Oryza Sativa L.) on acid soils

Summary Rock phosphates from Udaipur (India), North Carolina, Florida, Tennessee and Missouri (USA) were acidulated with HCl or H₂SO₄, to the extent of 25, 50, 75 or 100 per cent of the requirement for complete conversion into single superphosphate. Partial acidulation resulted in the formation of a mixture of water- and citrate-soluble and -insoluble phosphates, the proportion of the first two increasing with increasing degree of acidulation, at the expense of the insoluble phosphate. For a given degree of acidulation, the P compounds formed with HCl or H₂SO₄ were of comparable composition, except that the HCl-acidulated products were hygroscopic. Pot experiments with acid P-deficient soils showed that the behaviour of the HCl- or H₂SO₄- acidulated products in respect of P availability in soil, grain yield response and P uptake by rice was more or less similar. Partially acidulated rock phosphate to the extent of 50 per cent with either of the acids was found to be suitable for growing rice under flooded soil conditions. There is thus scope for the use of HCl- acidulated rock phosphate as a substitute for the H₂SO₄- acidulated product, for growing rice in acid soils. The scope for use of lower degree HCl-acidulated product in an upland crop — rice rotation in acid soils is also discussed.     

Characterization of a temperature-sensitive mutant of a ubiquitin-conjugating enzyme and its use as a heat-inducible degradation signal.

The ubiquitin/proteasome pathway is a highly conserved mechanism of proteolysis in all eukaryotes. Ubiquitin (Ub) is conjugated to proteolytic substrates through the sequential action of ubiquitin-activating (E1/Uba) and ubiquitin-conjugating (E2/Ubc) enzymes. The mechanism of substrate recognition and ubiquitination is an area of active investigation, and we have begun a site-directed mutagenesis approach to define the biochemical and biophysical properties of ubiquitin-conjugating enzymes. We have characterized a specific mutation in Ubc4 (Ubc4(P62S)) which was previously shown to cause a temperature-sensitive growth defect in several other Ubc's. Ubc4(P62S) was rapidly degraded in vivo, contributing to the loss of function. However, reconstitution experiments revealed that the catalytic activity of Ubc4(P62S) was reversibly inactivated at 37 degrees C, demonstrating that the primary defect of Ubc4(P62S) is its inability to form a ubiquitin thioester bond at high temperature. The in vivo defect is compounded by increased susceptibility of Ubc4(P62S) to degradation by the ubiquitin/proteasome pathway. We have exploited the temperature-dependent degradation of the P62S mutant to destabilize an otherwise stable test protein (glutathione S-transferase). The use of this mutant may provide a useful cis-acting temperature-inducible degradation signal.     

Studies on biological decomposition of wheat straw

Summary The screening of micro-organisms decomposing wheat straw was done under laboratory conditions on the basis of the amount of carbon mineralized from wheat straw during a period of four months. In general, inoculation of wheat straw with different micro-organisms had favorable effect on the amount of carbon mineralized. Among the bacterial and fungus cultures isolated from baited wheat straw an Aspergillus sp. (Isolate No. 18) proved to be the most rapid wheat straw decomposer under laboratory conditions. re]19751008