A flat squared conformation of an ascidiacyclamide derivative caused by chiral modification of an oxazoline residue

We designed a deoxazoline-ascidiacyclamide (dASC), cyclo(-L-Ile-L-allo-Thr-D-Val-thiazole-)(2), diastereomer having 10S, 11R, 37R, and 38S configurations ([SR,RS]dASC) and a corresponding product having 10S, 11S, 37R, and 38R configurations ([SS,RR]ASC) with the aim of understanding better the relationship between conformational behaviour and chirality. X-ray diffraction analysis revealed that [SR,RS]dASC is folded in a manner similar to other dASC analogues. By contrast, [SS,RR]ASC is a novel, flat conformer that is larger than the major square and folded ASC conformers and contains a cavity created by the flat peptide ring. In addition, [SS,RR]ASC retains approximately 60% of the cytotoxicity of the parent molecule.     

Psychological stress increases bilirubin metabolites in human urine

Some authors have suggested that psychological stress induces the production of reactive oxygen species (ROS). Some studies have supported that bilirubin exerts anti-oxidative effects in vivo. However, it is not known whether ROS induced by psychological stress provoke bilirubin oxidation in vivo. We investigated if the concentration of bilirubin oxidative metabolite (BOM), a bilirubin oxidative metabolite, increased in urine from subjects exposed to psychological stress. Sixty healthy male volunteers working in a pharmaceutical company were divided into a Group I which did not attend a conference, a Group II which attended a conference but did not deliver a speech, and a Group III which attended a conference and delivered speeches in the presence of the company executives. Subjective stress was scored (self-rating score) after subjects in Group III delivered their speeches at the conference. Urine was collected on the next day. The BOM concentrations, as measured by enzyme-linked immunosorbent assay, were normalized to the urinary concentration of creatinine. The concentration of BOM in Group III was significantly higher compared to that in Groups I and II (p<0.01 and p<0.05, respectively). Furthermore, in Group III, the concentration of BOM correlated with the self-rating stress score (r=0.53, p<0.01). These findings suggest that emotional stimuli are associated with an increase in the oxidative metabolites of bilirubin in human urine, and that BOMs could be useful markers of psychological stress.     

Prespore cell inducing factor, ψ factor,controls both prestalk and prespore gene expression in Dictyostelium development

Prespore cell‐inducing (psi, ψ) factor (PsiA), encoded by the psiA gene of Dictyostelium, is a secreted signal glycoprotein that induces prespore cell differentiation when added to monolayer cultures. In situ hybridization during normal development showed that the psiA gene is highly expressed in scattered cells at the mound stage and in prespore cells at the onset of culmination. The conventional prespore‐cell marker genes, cotC and pspA, were expressed normally in psiA^? and psiA overexpressing strains. Expressions of rnrB and cudA are repressed in the prestalk cells of a wild type slug to render prespore specific pattern. However, a promoter‐reporter fusion gene, rnrB:lacZ, showed an ectopic expression in the prestalk cells of the psiA^? strain while cudA(psp):lacZ did so in those of the psiA overexpressing strain. Overexpression of psiA delayed expression of the prestalk specific gene, ecmB, during development, while knocking out psiA promoted its expression. In addition, overexpression inhibited DIF‐1‐induced stalk formation in monolayer cultures. Together with the known prespore inducing activity, the results indicate that PsiA regulates both prespore and prestalk/stalk cell differentiation. These results indicate that PsiA is also involved in prestalk cell differentiation.     

Distribution of Glutamate Transporter Subtypes During Human Brain Development

Abstract: In the mature brain, removal of glutamate from the synaptic cleft plays an important role in the maintenance of subtoxic levels of glutamate. This requirement is handled by a family of glutamate transporters, EAAT1, EAAT2, EAAT3, and EAAT4. Due to the involvement of glutamate also in neuronal development, it is believed that glutamate transport plays a role in developmental processes as well. Therefore, we have used immunohistochemical and immunoblot analysis to determine the distribution of the four glutamate transporters during human brain development using human pre- and postnatal brain tissue. Regional analysis showed that each transporter subtype has a unique distribution during development. EAAT2 was the most prominent glutamate transporter subtype and was highly enriched in cortex, basal ganglia, cerebellum, and thalamus in all ages examined. EAAT1 immunoreactivity was lower than that of EAAT2, with predominant localization in cortex, basal ganglia, hippocampus, and periventricular region. EAAT3 was located mainly in cortex, basal ganglia, and hippocampus, and EAAT4 was found only in cortex, hippocampus, and cerebellar cortex. The distinct regional distribution of various EAAT subtypes and also the transient expression of specific EAAT subtypes during development suggest multiple functional roles for glutamate transporters in the developing brain.     

Multi-factor decision-making strategy for better coronary plaque burden increase prediction: a patient-specific 3D FSI study using IVUS follow-up data

Biomechanics and Modeling in Mechanobiology - Plaque progression and vulnerability are influenced by many risk factors. Our goal is to find a simple method to combine multiple risk factors for...     

Fermentation,Isolation and Characterization of Isonitrile Antibiotics

A number of soil isolates belonging to the genus Trichoderma were found to produce isonitrins A, B, C and D and isonitrinic acids E and F, a new class of antibiotics characterized by the presence of isonitrile groups. Taxonomy of the producing organisms, fermentation, isolation and physicochemical and biological properties of isonitrins and isonitrinic acids are reported. Isonitrin A showed the highest in vitro antimicrobial activities against gram-positive and negative bacteria and fungi.     

Chromosomal Banding Patterns Produced by Methyl Green-Pyronin Staining After Trypsin Treatment

A method is described for producing banding pattern with methyl green-pyronin (MGP) stain in chromosomes of fibrosarcoma cells. 1) The stain was made by mixing equal volumes of 2% aqueous pyronin G, 2% aqueous methyl green, distilled water, and 0.1 M acetate Mer (pH 5.7). 2) Treatment with colcemide and hypotonic KCI (0.075 M) was performed u usual. 3) Metaphase chromosomes were prepared using the flame-drying technique and treated with 0.25% trypsin at 37 C for 45 to 90 seconda. Before staining, the slides were rid in PBS, in distilled water, and then were dipped in 0.05 M acetate buffer. 4) Chromosomes were stained for more than 20 minuta, rinsed in distilled water, and hot-air dried. satisfactory results were obtained in uncontracted metaphase chromosomes. MCP stain hm the advantage of permitting much longer trypsin treatment and staining time than the trypsin-Giemsa method while providing satisfactory banding pattern.