Synthesis and characterization of pyridine N-oxide complexes of manganese, copper and zinc

A series of metal carboxylates containing pyridine N-oxide are prepared via one pot synthesis and solid phase synthesis. The structural variations from metal to metal are observed. In the case of reactions of manganese(II) acetate with pyridine N-oxide in the presence of aromatic carboxylic acids, polymeric complexes with bridging aromatic carboxylate as well as bridging pyridine N-oxide are observed. Whereas, the reaction of copper(II) acetate with pyridine N-oxide in the presence of an aromatic carboxylic acid led to mononuclear or binuclear paddle wheel carboxylate complexes with monodentate pyridine N-oxide. Co-crystal of two neutral complexes having composition [Cu₂(OBz)₄(MeOH)₂][Cu₂(OBz)₄(pyO)₂] (where OBz = benzoate, pyO = pyridine N-oxide) each neutral parts have paddle wheel structure. Solid phase reaction of zinc chloride with sodium benzoate prepared in situ and pyridine N-oxide leads to a tetra-nuclear zinc complex.     

UDP-Gal: <Emphasis Type="Italic">N</Emphasis>-acetylglucosamine β 1–4 galactosyltransferase expressing live attenuated parasites as vaccine for visceral leishmaniasis

As compared to cutaneous leishmaniasis, vaccination against visceral leishmaniasis (VL) has received limited attention. In this study, we demonstrate for the first time that an UDP-Galactose: N-acetylglucosamine β 1–4 galactosyltransferase (GenBank Accession No. EF159943) expressing attenuated LD clonal population (A-LD) is able to confer protection against the experimental challenge with the virulent LD AG83 parasite. A-LD was also effective in established leishmania infection. The vaccinated animals showed both cell mediated (in vitro T-cell proliferation, and DTH response) and humoral responses (Th1 type). These results demonstrate the potential of the attenuated clones as an immunotherapeutic and immunoprophylactic agent against visceral leishmaniasis.     

Distribution and population variation of total number of palmar triradii among 20 Dhangar castes of Maharashtra,India

The paper deals with the bilateral palmar prints of 3000 males belonging to 20 Dhangar castes of Maharashtra which were analysed (1) to compare the pattern of variation of palmar triradii with respect to other traits, (2) to examine the degree of similarity between clusters based on dermatoglyphics anthropometry and genetic markers and (3) relating these similarities with their ethnographic and geographic proximities. The results of this study confirm the general presumptions, (a) that dermal traits, in general, and palmar characters, in particular, do help in understanding the biologic/ethnic affinities among different groups both at macro and micro levels and (b) the different types of traits, which are likely to be influenced by different genetic and/or environmental factors give rise to different clustering patterns.     

Purification and partial characterization of two azoreductases from Shigella dysenteriae Type 1

Two azoreductases (I and II) were purified to homogeneity from extracts of Shigella dysenteriae (type 1). Azoreductase I was a dimer of identical subunits of M(r) 28,000, whereas azoreductase II was a monomer of 11,000 M(r). Both were flavoproteins, each containing 1 mol of FMN per mol enzyme. Both NADH and NADPH functioned as electron donors for the azoreductases. Azoreductase I used Ponceau SX, Tartrazine, Amaranth and Orange II as substrates. Azoreductase II utilized all the dyes except Amaranth.     

Inhibition of red light-induced seed germination by indole-3-acetic acid inHygrophila auriculata

Seed germination inHygrophila auriculata (Schumach.) Haines was found to be under phytochrome control. Exogenous indole-3-acetic acid (IAA) application at concentrations greater than 1×10^–6 M inhibited germination in the dark, as well as in the light. Red light-induced radicle growth, prior to radicle protrusion through seed coverings and measured as an angle formed by the radicle with the seed axis, was found to be inhibited by IAA. Delay in application of IAA to red light-irradiated seeds resulted in a gradual increase in percent germination, which probably corresponded to the time-course of Pfr action. It is suggested that exogenously applied IAA probably reimposes dormancy in red light-induced seeds ofHygrophila auriculata.     

Microbial growth on carbon monoxide

The utilization of carbon monoxide as energy and/or carbon source by different physiological groups of bacteria is described and compared. Utilitarian CO oxidation which is coupled to the generation of energy for growth is achieved by aerobic and anaerobic eu- and archaebacteria. They belong to the physiological groups of aerobic carboxidotrophic, facultatively anaerobic phototrophic, and anaerobic acetogenic, methanogenic or sulfate-reducing bacteria. The key enzyme in CO oxidation is CO dehydrogenase which is a molybdo iron-sulfur flavoprotein in aerobic CO-oxidizing bacteria and a nickel-containing iron-sulfur protein in anaerobic ones. In carboxidotrophic and phototrophic bacteria, the CO-born CO₂ is fixed by ribulose bisphosphate carboxylase in the reductive pentose phosphate cycle. In acetogenic, methanogenic, and probably in sulfate-reducing bacteria, CODH/acetyl-CoA synthase directly incorporates CO into acetyl-CoA.In plasmid-harbouring carboxidotrophic bacteria, CO dehydrogenase as well as enzymes involved in CO₂ fixation or hydrogen utilization are plasmid-encoded. Structural genes encoding CO dehydrogenase were cloned from carboxidotrophic, acetogenic and methanogenic bacteria. Although they are clustered in each case, they are genetically distinct.Soil is a most important biological sink for CO in nature. While the physiological microbial groups capable of CO oxidation are well known, the type and nature of the microorganisms actually representing this sink are still enigmatic. We also tried to summarize the little information available on the nutritional and physicochemical requirements determining the sink strength. Because CO is highly toxic to respiring organisms even in low concentrations, the function of microbial activities in the global CO cycle is critical.     

Role of Ca2+ ion on Leishmania-macrophage attachment

Summary Leishmania donovani, the etiological agent for the disease visceral leishmaniasis, attach themselves to the macrophages for initiation of the disease. The attachment process has been found to be regulated by Ca²⁺ ions. Verapamil, a Ca²⁺-channel blocker inhibits Leishmania-macrophage attachment. The inhibitory effect is increased with time. Nifedipine, another Ca²⁺-channel blocker exhibits the same effect. The attachment process is stimulated by Ca²⁺-ionophore alone. The inhibitory effects of the calcium channel blockers are reversed by the ionophore.     

Structural analysis of a maize gene coding for glutathione-S-transferase involved in herbicide detoxification

Summary We have used the cDNA clone encoding maize glutathione-S-transferase (GST I) to isolate a genomic DNA clone containing the complete GST I gene. Nucleotide sequence analysis of the cDNA and genomic clones has yielded a complete amino acid sequence for maize GST I and provided the exon-intron map of its gene. The mRNA homologous sequences in the maize GST I gene consist of a 107 bp 5 untranslated region, a 642 bp coding region and 340 bp of the 3 untranslated region. They are divided into three exons by two introns which interrupt the coding region. The 5 untranslated spacer contains an unusual sequence of pentamer AGAGG repeated seven times. The inbred maize line (Missouri 17) contains a single gene for GST I, whereas the hybrid line (3780A) contains two genes. Nucleotide sequence analysis of the primer extended cDNA products reveals that the 5 untranslated regions of the two genes in the hybrid 3780A are identical except for a 6 bp internal deletion (or insertion). The amino acid sequence of maize GST I shares no apparent sequence homology with the published sequences of animal GST's and represents the first published sequence of a plant GST. re]19850813 ac]19851126     

Immunoblotting identifies and antigen recognized by anti gp63 in the immune complexes of Indian kala-azar patient sera

In SDS-PAGE the immune complexes (IC) of kala-azar patient sera showed intense bands at 55 kDa and 20 kDa corresponding to heavy and light chains of immunoglobulins. In immunoblot experiment, kala-azar and normal IC after treatment with patient sera showed multiple bands of which the band at 55 kDa was most prominent in kala-azar IC. It is known that in kala-azar sera antihuman IgG is present, so the heavy band at 55 kDa region may be due to higher amount of IgG and/or other antigen(s) present at that region. Immunoblot experiments of kala-azar IC with anti gp63 also developed a major band at 55 kDa. It suggests that the antigen (55 kDa) and gp63 have common antigenic epitope (s). Normal IC did not react with anti gp63 indicating absence of this antigen in normal IC. Antigenic similarity between the IC antigen (55 kDa) and gp63 indicated that the former antigen may have been processed from gp63. In summary, identification of a parasite antigen (55 kDa) in IC of kala-azar patients sera may be useful in developing a serodiagnostic assay for visceral leishmaniasis. (Mol Cell Biochem130: 11–17, 1994)Abbreviations IC Immune Complexes - PEG Polyethylene Glycol (Mol wt 8000) - PBS Phosphate Buffer Saline - VL Visceral Leishmaniasis - AVL American Visceral Leishmaniasis - IgG Immunoglobulin G - TBS Tris Buffer Saline - SDS-PAGE Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis - gp63 A leishmanial surface glycoprotein of molecular mass 63,000 - TEMED N,N,N,N-Tetramethylethylenediamine