The microflora of ulzerous zone mucosa in patients with duodenal ulcer

Bacteriological study of the biopsies taken from gastric and duodenal mucosa of 10 healthy volunteers and 74 patients with duodenal ulcer, was carried out. In the gastroduodenal zone of healthy subjects microorganisms of 6 genera (Streptococcus, Candida, Staphylococcus, Bacillus, Helicobacter and Lactobacillus) were detected. H. pylori was isolated in 20% of cases only in biopsy specimens taken from the antral section of the stomach of healthy as monoculture or in combination with C. albicans. In patients with duodenal ulcer activation of opportunistic microflora was observed in the periulcerous zone. More often H. pylori occurred in associations with fungi of the genus Candida, streptococci, staphylococci, enterobacteria, Pseudomonas and other microorganisms (of more than 30 genera). Quantitatively the dominating microorganisms (3.8-5.7 lg CFU/g) were H. pylori, fungi of the genus Candida, bacteria of the genera Streptococcus, Peptostreptococcus, Bacteroides, Gemella, Prevotella, Veillonella, Peptococcus, Bacillus, different species of opportunistic enterobacteria, as well as bacteria of the genera Staphylococcus, Micrococcus, Corynebacterium, Neisseria, Pseudomonas, etc. Opportunistic bacteria detected in the ulcerous zone, as a rule, expressed hemolytic, lecithinase, RNAase, caseinolytic, catalase and urease activity. Sonicated filtrates of such cultures produced a cytotoxic effect on cells HEp-2. Ulcer is an infected wound that needs sanitation.     

Expression of a fragment of the env gene, coding for the GP46 surface glycoprotein of the human T-cell leukemia virus, in Escherichia coli cells

Designing of recombinant plasmids pSB2 and pSB3 with the 932 bp HTLV-II env gene inserts encoding the full-length surface membrane glycoprotein gp46 is described. Vectors pGOmpF and pET32a expressing genes cloned under control of the late bacteriophage T7 promoter were used. Western blot analysis of cellular proteins derived from E. coli B834/pSB2 and E. coli B834/pSB3 revealed that 34 kD and 31 kD polypeptides corresponding to the full-length gp46 and its processed form without signal peptide were synthesized under control of these recombinant plasmids. Cytotoxic activity of the recombinant proteins towards bacterial cells was demonstrated. Both polypeptides specifically reacted to sera from humans infected with HTLV-II. High antigenic specificity of P34-HTLV-II proteins makes a promising candidate for diagnostic confirmation tests.     

Model of "standing water" of Baikalian phytoplankton interannual dynamics

A "standing waves" model is presented which is based on the idea that an energy impulse accumulated from the spring bloom outburst of phytoplankton moves along a food chains. When its "echo" comes back, it generates a new bloom outburst, and a next cycle occurs. It is supposed that the resonance of self-supporting oscillations in populations with periodic solar influences led to standing waves, which provide for biosystem stability and cyclic recurrence of phytoplankton bloom. To test the model, an analysis of the interannual dynamics (from 1941 to 1998) of the pelagic phytoplankton in the southern basin of the lake Baikal was carried out. The discovered 11-year cycles with 3 2/3-year cycles within them conform well to the model, which made it possible to explain not only the cyclic recurrence but also a number of other obscure aspects of phytoplankton life in the lake Baikal. The next bloom burst is predicted to take place in 2001.     

Phosphorylation by cyclin-dependent protein kinase 5 of the regulatory subunit of retinal cGMP phosphodiesterase. I. Identification of the kinase and its role in the turnoff of phosphodiesterase in vitro

Cyclic GMP phosphodiesterase (PDE) is an essential component in retinal phototransduction. PDE is regulated by Pgamma, the regulatory subunit of PDE, and GTP/Talpha, the GTP-bound alpha subunit of transducin. In previous studies (Tsuboi, S., Matsumoto, H. , Jackson, K. W., Tsujimoto, K., Williamas, T., and Yamazaki, A. (1994) J. Biol. Chem. 269, 15016-15023; Tsuboi, S., Matsumoto, H., and Yamazaki, A. (1994) J. Biol. Chem. 269, 15024-15029), we showed that Pgamma is phosphorylated by a previously unknown kinase (Pgamma kinase) in a GTP-dependent manner in photoreceptor outer segment membranes. We also showed that phosphorylated Pgamma loses its ability to interact with GTP/Talpha, but gains a 10-15 times higher ability to inhibit GTP/Talpha-activated PDE than that of nonphosphorylated Pgamma. Thus, we propose that the Pgamma phosphorylation is probably involved in the recovery phase of phototransduction through shut off of GTP/Talpha-activated PDE. Here we demonstrate that all known Pgammas preserve a consensus motif for cyclin-dependent protein kinase 5 (Cdk5), a protein kinase believed to be involved in neuronal cell development, and that Pgamma kinase is Cdk5 complexed with p35, a neuronal Cdk5 activator. Mutational analysis of Pgamma indicates that all known Pgammas contain a P-X-T-P-R sequence and that this sequence is required for the Pgamma phosphorylation by Pgamma kinase. In three different column chromatographies of a cytosolic fraction of frog photoreceptor outer segments, the Pgamma kinase activity exactly coelutes with Cdk5 and p35. The Pgamma kinase activity ( approximately 85%) is also immunoprecipitated by a Cdk5-specific antibody, and the immunoprecipitate phosphorylates Pgamma. Finally, recombinant Cdk5/p35, which were expressed using clones from a bovine retina cDNA library, phosphorylates Pgamma in frog outer segment membranes in a GTP-dependent manner. These observations suggest that Cdk5 is probably involved in the recovery phase of phototransduction through phosphorylation of Pgamma complexed with GTP/Talpha in mature vertebrate retinal photoreceptors.     

Selective inhibition of inducible NO-synthase by nonselective inhibitor

The study has shown that Nw-nitro-L-arginine, a nonselective nitric oxide (NO) inhibitor, in low non-vasoactive doses (10 mg/kg) exerted a protective effect in heat shock as demonstrated by a decrease in the mortality rate and prevention of acute hypotension in rats. The L-NNA in the same dose inhibited the basal NO production but left unaffected a carbachol-activated NO production. The findings suggest a possibility in principle of preferential inhibition of inducible NO-synthase in pathological conditions related to the NO overproduction using non-vasoactive doses of L-NNA the nonselective NO-synthase inhibitor.     

Phosphodiesterase 4D (<Emphasis Type="Italic">PDE4D</Emphasis>) gene polymorphism in patients with acute stroke from Moscow

Two PDE4D gene polymorphisms [SNP41 (rs152312 and SNP87 (rs2910829)] were studied in patients with acute stroke (n = 577) and in control sample (n = 270). Significant differences in the genotype and allele frequency distribution were found between these samples for polymorphism SNP41. We showed that the AA and AG genotypes of SNP41 polymorphism were associated with higher risk of acute stroke development in the Moscow population (OR = 1.6). No association of SNP87 polymorphism with the disease was observed.     

Molecular and morphological characterization of somatic hybrids between <Emphasis Type="Italic">Solanum tuberosum</Emphasis> L. and <Emphasis Type="Italic">S. etuberosum</Emphasis> Lindl.

Interspecific potato somatic hybrids between Solanum tuberosum L. (di)haploid C-13 and 1 endosperm balance number non-tuberous wild species S. etuberosum Lindl. were produced by protoplasts electrofusion. The objective was to transfer virus resistance from this wild species into the cultivated potatoes. Post-fusion products were cultured in VKM medium followed by regeneration of calli in MS₁₃ K medium at 20°C under a 16-h photoperiod, and regenerants were multiplied on MS medium. Twenty-one somatic hybrids were confirmed by RAPD, SSR and cytoplasm (chloroplast/mitochondria) type analysis possessing species-specific diagnostic bands of corresponding parents. Tetraploid nature of these somatic hybrids was determined through flow cytometry analysis. Somatic hybrids showed intermediate phenotypes (plant, leaves and floral morphology) to their parents in glass-house grown plants. All the somatic hybrids were male-fertile. ELISA assay of somatic hybrids after artificial inoculation of Potato virus Y (PVY) infection reveals high PVY resistance.     

Passive immunization against the MHC class I molecule Mamu-AG disrupts rhesus placental development and endometrial responses

The unique MHC phenotype of the human and nonhuman primate placenta has suggested a potential role in maternal-fetal immune tolerance, pregnancy success, and maternal as well as fetal well-being. In the rhesus monkey (Macaca mulatta) a nonclassical MHC class I molecule, Mamu-AG, is a putative homologue of HLA-G and is hypothesized to play a role in maternal-fetal immune interactions during pregnancy. Rhesus monkeys were passively immunized during the second week after implantation with a mAb against Mamu-AG. Passive immunization altered the growth and vascularization of the fetal placenta, the placental modification of maternal endometrial vessels, the maternal leukocyte response to implantation, and the differentiation of epithelial and stromal cells in the endometrium. These data are the first to demonstrate in vivo the importance of MHC class I molecules expressed on primate trophoblasts in establishing an important environment for pregnancy success through coordinated interactions between endometrial and fetal tissues.     

Oxidation of methionine residues in recombinant human interleukin-1 receptor antagonist: implications of conformational stability on protein oxidation kinetics

Oxidation of methionine residues is involved in several biochemical processes and in degradation of therapeutic proteins. The relationship between conformational stability and methionine oxidation in recombinant human interleukin-1 receptor antagonist (rhIL-1ra) was investigated to document how thermodynamics of unfolding affect methionine oxidation in proteins. Conformational stability of rhIL-1ra was monitored by equilibrium urea denaturation, and thermodynamic parameters of unfolding (DeltaGH2O, m, and Cm) were estimated at different temperatures. Methionine oxidation induced by hydrogen peroxide at varying temperatures was monitored during "coincubation" of rhIL-1ra with peptides mimicking specific regions of the reactive methionine residues in the protein. The coincubation study allowed estimation of oxidation rates in protein and peptide at each temperature from which normalized oxidation rate constants and activation energies were calculated. The rate constants for buried Met-11 in the protein were lower than for methionine in the peptide with an associated increase in activation energy. The rate constants and activation energy of solvent exposed methionines in protein and peptide were similar. The results showed that conformational stability, monitored using the Cm value, has an effect on oxidation rates of buried methionines. The rate constant of buried Met-11 correlated well with the Cm value but not DeltaGH2O. No correlation was observed for the oxidation rates of solvent-exposed methionines with any thermodynamic parameters of unfolding. The findings presented have implications in protein engineering, in design of accelerated stability studies for protein formulation development, and in understanding disease conditions involving protein oxidation.