Identification of vascular endothelial cells in murine omentum using the lectin, Dolichos biflorus agglutinin: possible applications in the study of angiogenesis

Summary The purpose of this study was to determine whether the plant lectin,Dolichos biflorus agglutinin (DBA), can be used to recognize capillary endothelial cells and their processes during angiogenesis. By means of a peroxidase conjugate of DBA, blood vessels were visualized in whole mounts and ultrathin sections of mouse omentum. A part of this mesentery normally comprises an avascular membrane that is approximately 30 µm in thickness. Changes in the vascular plexus bordering this membrane were induced by intraperitoneal injection of irradiated Landschutz cells. Vascular endothelial cells were precisely and intensely stained, and vasculogenic processes were reliably distinguished from those of other cells. This technique permitted observation of the structure and distribution of capillary sprouts, and their relationship to each other and to pre-existing blood vessels. It was discovered that filiform projections extend from sprout apices. These projections may fuse allowing adjacent sprouts to form a new capillary loop.     

A 13C comparative nuclear magnetic resonance study of organic solute production and excretion by the yeasts Hansenula anomala and Saccharomyces cerevisiae in saline media

Glycerol, arabitol and trehalose were the principle solutes detected in cellular extracts of Hansenula anomala, using natural-abundance 13C nuclear magnetic resonance spectroscopy. Only the two polyols accumulated in response to increased salinity, glycerol increase being far greater. Arabitol content also increased with culture age, independently of the presence or absence of salt and in line with the evolution of trehalose content. Glycerol retention potential was 15 times greater for Hansenula than for Saccharomyces cerevisiae. The former displayed the specific property of increasing this capacity in high salt concentrations. Under such conditions its growth was associated with a limited increase in glucose consumption per unit biomass, relative to S. cerevisiae, the salt-sensitive reference yeast. In addition, a polysaccharide, the chemical nature of which was not further characterized, was detected exclusively in the external medium of Hansenula growing in the presence of salt.     

Glutathione Peroxidase 4 is associated with Neuromelanin in Substantia Nigra and Dystrophic Axons in Putamen of Parkinson's brain

Fibrillar amyloid β (fAβ) peptide is the major component of Aβ plaques in the brains of Alzheimer's disease (AD) patients. Inflammatory mediators have previously been proposed to be drivers of Aβ pathology in AD patients by increasing amyloidogenic processing of APP and promoting Aβ accumulation, but recent data have shown that expression of various inflammatory cytokines attenuates Aβ pathology in mouse models. In an effort to further study the role of different inflammatory cytokines on Aβ pathology in vivo, we explored the effect of murine Tumor Necrosis Factor α (mTNFα) in regulating Aβ accumulation. Recombinant adeno-associated virus serotype 1 (AAV2/1) mediated expression of mTNFα in the hippocampus of 4 month old APP transgenic TgCRND8 mice resulted in significant reduction in hippocampal Aβ burden. No changes in APP levels or APP processing were observed in either mTNFα expressing APP transgenic mice or in non-transgenic littermates. Analysis of Aβ plaque burden in mTNFα expressing mice showed that even after substantial reduction compared to EGFP expressing age-matched controls, the Aβ plaque burden levels of the former do not decrease to the levels of 4 month old unmanipulated mice. Taken together, our data suggests that proinflammatory cytokine expression induced robust glial activation can attenuate plaque deposition. Whether such an enhanced microglial response actually clears preexisting deposits without causing bystander neurotoxicity remains an open question.     

Virulence determinants, drug resistance and mobile genetic elements of Laribacter hongkongensis: a genome-wide analysis

Background

Laribacter hongkongensis is associated with community-acquired gastroenteritis and traveler's diarrhea. In this study, we performed an in-depth annotation of the genes in its genome related to the various steps in the infective process, drug resistance and mobile genetic elements.

Results

For acid and bile resistance, L. hongkongensis possessed a urease gene cassette, two arc gene clusters and bile salt efflux systems. For intestinal colonization, it possessed a putative adhesin of the autotransporter family homologous to those of diffusely adherent Escherichia coli (E. coli) and enterotoxigenic E. coli. To evade from host defense, it possessed superoxide dismutase and catalases. For lipopolysaccharide biosynthesis, it possessed the same set of genes that encode enzymes for synthesizing lipid A, two Kdo units and heptose units as E. coli, but different genes for its symmetrical acylation pattern, and nine genes for polysaccharide side chains biosynthesis. It contained a number of CDSs that encode putative cell surface acting (RTX toxin and hemolysins) and intracellular cytotoxins (patatin-like proteins) and enzymes for invasion (outer membrane phospholipase A). It contained a broad variety of antibiotic resistance-related genes, including genes related to β-lactam (n = 10) and multidrug efflux (n = 54). It also contained eight prophages, 17 other phage-related CDSs and 26 CDSs for transposases.

Conclusions

The L. hongkongensis genome possessed genes for acid and bile resistance, intestinal mucosa colonization, evasion of host defense and cytotoxicity and invasion. A broad variety of antibiotic resistance or multidrug resistance genes, a high number of prophages, other phage-related CDSs and CDSs for transposases, were also identified.     

Synthesis and evaluation of in vitro antioxidant capacities of some benzimidazole derivatives

New, except 1d, melatonin analogue benzimidazole derivatives were synthesized and characterized in the present study. The potential role of melatonin as an antioxidant by scavenging and detoxifying ROS raised the possibility that compounds that are analogous to melatonin can also be used for their antioxidant properties. Therefore the antioxidant effects of the newly synthesized compounds were investigated in vitro by means of their inhibitory effect on hydrogen peroxide-induced erythrocyte membrane lipid peroxidation (EMLP) and on various erythrocyte antioxidant enzymes viz. superoxide dismutase (SOD), catalase (CAT) and glucose-6-phosphate dehydrogenase (G6PD). The synthesized benzimidazole derivatives showed remarkable antioxidant activity in vitro in the H₂O₂-induced EMLP system. Furthermore their effects on various antioxidant enzymes are discussed and evaluated from the perspective of structure- activity relationships.     

Notes On The Occurrence Of Clathrus Cancellatus,Tournf., In Argyllshire

Background: Estuaries are characterised by salinity gradients and regular flooding events. These environmental factors form stress gradients, along which species composition changes.

Aims: Analyse and compare patterns of plant species diversity along the estuarine salinity and flooding gradients of the Elbe and Connecticut Rivers.

Methods: Vegetation was sampled at three elevations (low, mid, high) in five sites of each marsh type (fresh, brackish, salt) in both estuaries. Patterns of species density (SD) and evenness (E) along the gradients were analysed and compared between the two estuaries with three-factor ANOVAs.

Results: The regional species pool was 33% higher for the Connecticut than for the Elbe. SD of fresh marshes (19 ± 2.2) was more than twice in the Connecticut than in the Elbe. We found an overall increase in SD from low to high elevation and from salt to freshwater marshes in both estuaries. However, SD and E were strongly depressed at intermediate elevations in the Elbe fresh and brackish marshes.

Conclusions: Although diversity patterns in the two estuaries show overall similarities, patterns of SD and E differ, when particular elevational zones and marsh types are compared. We hypothesise this to be due to evolutionary and historical influences on the regional species pools, shaping the impact of local biotic and abiotic processes.