Inhibition of Candida albicans secreted aspartic protease by a novel series of peptidomimetics,also active on the HIV-1 protease

Nineteen reduced amide, monohydroxy- or dihydroxyethylene-based transition-state peptidomimetics, known to be good inhibitors of the aspartic protease of HIV-1, were tested against a secreted aspartic protease (Sap2), purified from the culture medium of a virulent strain of Candida albicans. Ten of these compounds exhibited IC(50)s against Sap2 lower than 15 microM; the best inhibitor, Kyn-Val-Phe-Psi[OH-OH]-Phe-Val-Kyn, when added to the C. albicans culture, repressed the hydrolysis of bovine serum albumin (BSA), contained in the culture medium, and inhibited the growth of the fungus.     

Diastereo- and enantioselective synthesis of 1'-C-branched N,O-nucleosides

A synthetic approach towards 1'-C-branched N,O-nucleosides is reported, based on 1,3-dipolar cycloaddition of ethoxycarbonylnitrone. The asymmetric version of the process exploits the presence of a chiral auxiliary at the carbon atom of nitrone and leads to beta-D and beta-L nucleosides in good yields.     

Disruption of a Global Regulatory Gene to Enhance Central Carbon Flux into Phenylalanine Biosynthesis in Escherichia coli

Genetic engineering of microbes for commercial metabolite production traditionally has sought to alter the levels and/or intrinsic activities of key enzymes in relevant biosynthetic pathway(s). Microorganisms exploit similar strategies for flux control, but also coordinate flux through sets of related pathways by using global regulatory circuits. We have engineered a global regulatory system of Escherichia coli, Csr (carbon storage regulator), to increase precursor for aromatic amino acid biosynthesis. Disruption of csrA increases gluconeogenesis, decreases glycolysis, and thus elevates phosphoenolpyruvate, a limiting precursor of aromatics. A strain in which the aromatic (shikimate) pathway had been optimized produced twofold more phenylalanine when csrA was disrupted. Overexpression of tktA (transketolase) to increase the other precursor, erythrose-4-phosphate, yielded ∼1.4-fold enhancement, while both changes were additive. These effects of csrA were not mediated by increasing the regulatory enzymes of phenylalanine biosynthesis. This study introduces the concept of “global metabolic engineering” for second-generation strain improvement. Received: 25 October 2000 / Accepted: 8 December 2000     

RET rearrangements in papillary thyroid carcinomas and adenomas detected by interphase FISH

Activation of the RET protooncogene through somatic rearrangements represents the most common genetic alteration in papillary thyroid carcinoma (PTC). Three main rearranged forms of RET have been described: RET/PTC1 and RET/PTC3, which arise from a paracentric inversion of the long arm of chromosome 10, and RET/PTC2, which originates from a 10;17 translocation. We have developed a dual-color FISH approach to detect RET/PTC rearrangements in interphase nuclei of thyroid lesions. By using a pool of three cosmids encompassing the RET chromosome region and a chromosome 10 centromeric probe, we could discriminate between the presence of an inversion (RET/PTC1 and RET/PTC3) or a translocation (RET/PTC2). We have investigated a series of thyroid tissue samples from Italian and French patients corresponding to a total of 69 PTCs and 22 benign lesions. Among PTCs, 13 (18.8%) showed a RET rearrangement, and 11 (15.9%) of these carried an inversion (RET/PTC1 or RET/PTC3) in more than 10% of the nuclei examined. Activated forms of RET were also observed in three adenomas. RT-PCR analysis on the same samples confirmed the presence and the type of rearrangement predicted using FISH analysis. An interesting difference in the frequency and type of RET rearrangements was detected between the Italian and the French patients. Furthermore, we identified a putative novel type of rearrangement in at least one PTC sample. Several PTCs carried a significant number of cells characterized by a trisomy or a tetrasomy of chromosome 10. Overall, the FISH approach in interphase nuclei represents a powerful tool for detecting, at the single cell level, RET/PTC rearrangements and other anomalies involving the RET chromosome region.     

Effects of gonadal steroids during pubertal development on androgen and estrogen receptor-alpha immunoreactivity in the hypothalamus and amygdala

Perinatal development is often viewed as the major window of time for organization of steroid-sensitive neural circuits by steroid hormones. Behavioral and neuroendocrine responses to steroids are dramatically different before and after puberty, suggesting that puberty is another window of time during which gonadal steroids affect neural development. In the present study, we investigated whether the presence of gonadal hormones during pubertal development affects the number of androgen receptor and estrogen receptor alpha-immunoreactive (AR-ir and ER alpha-ir, respectively) cells in limbic regions. Male Syrian hamsters were castrated either before or after pubertal development, and 4 weeks later they received a single injection of testosterone or oil vehicle 4 h prior to tissue collection. Immunocytochemistry for AR and ER alpha was performed on brain sections from testosterone-treated and oil-treated males, respectively. Adult males that had been castrated before puberty had a greater number of AR-ir cells in the medial preoptic nucleus than adult males that had been castrated after puberty. There were no significant differences in ER alpha-ir cell number in any of the brain regions examined. The demonstration that exposure to gonadal hormones during pubertal development is associated with reduced AR-ir in the medial preoptic nucleus indicates that puberty is a period of neural development during which hormones shape steroid-sensitive neural circuits.     

The PNPLA3 Ile148Met interacts with overweight and dietary intakes on fasting triglyceride levels

The Ile148Met (rs738409, G-allele) in the patatin-like phospholipase domain-containing protein 3 gene (PNPLA3) associates with liver fat content and may lead to loss-of-function (hydrolysis) or gain-of-function (CoA-dependent lysophosphatidic acid acyltransferase) defects. PNPLA3 is up-regulated by dietary carbohydrates, and interactions between rs738409 and carbohydrates, and sugar and ω6:ω3-polyunsaturated fatty acid (PUFA) ratio on hepatic fat accumulation have been reported. We examined interaction between rs738409 and overweight, and between rs738409 and dietary intakes (carbohydrates, sucrose and ω6:ω3-PUFA ratio), on fasting triglyceride levels. From the Malmo Diet and Cancer Study-Cardiovascular Cohort, 4,827 individuals without diabetes aged 58 ± 6 years, 2,346 with BMI ≤ 25 kg/m² and 2,478 with BMI > 25 kg/m², were included in cross-sectional analyses. Dietary data were collected by a modified diet history method. Overweight modified the association between rs738409 and fasting triglyceride levels (P_interaction = 0.003). G-allele associated with lower triglycerides only among overweight individuals (P = 0.01). Nominally, significant interaction on triglyceride levels was observed between rs738409 and sucrose among normal-weight individuals (P_interaction = 0.03). G-allele associated with lower triglycerides among overweight individuals in the lowest tertiles of carbohydrate and ω6:ω3-PUFA ratio (P = 0.04 and P = 0.001) and with higher triglycerides among normal-weight individuals in the highest tertile of sucrose (P = 0.001). We conclude that overweight and dietary sucrose may modify the association between rs738409 and fasting triglyceride levels.

Electronic supplementary material

The online version of this article (doi:10.1007/s12263-014-0388-4) contains supplementary material, which is available to authorized users.     

Age and growth of pearly razorfish,Xyrichtys novacula (Linnaeus 1758), in the central Mediterranean Sea

Age and growth of pearly razorfish Xyrichtys novacula (Labridae) were determined in specimens caught on sandy bottoms by surrounding nets and lines (depth range 5–30 m) between January 2000 and December 2002. The study location was in the central Mediterranean Sea. For this purpose the annual growth increments (annuli) in sagittae were analysed. A total of 470 individuals of X. novacula, ranging from 49 to 200 mm TL (total length), were examined. Conversion between total length and standard length was calculated and represented by the relationship: . Edge analysis on otoliths was carried out to validate seasonality deposition. Seven age‐classes were determined from 0+ to 6+. The linear relationship between maximum otolith length (OL) and TL was summarized in the equation . The estimated parameters of the von Bertalanffy growth function were L = 175.05 mm, k = 0.80 year^?1, t₀ =?0.73 years and the growth performance index calculated as (Φ = 2.39). The length–weight relationship W = 0.0139 TL^2.9326 described an isometric growth for the species in this area.