Junker: An Intergenic Explorer for Bacterial Genomes

In the past few decades, scientists from all over the world have taken a keen interest in novel functional units such as small regulatory RNAs, small open reading frames, pseudogenes, transposons, integrase binding attB/attP sites, repeat elements within the bacterial intergenic regions (IGRs) and in the analysis of those junk regions for ge- nomic complexity. Here we have developed a web server, named Junker, to facilitate the in-depth analysis of IGRs for examining their length distribution, four-quadrant...     

大剂量HBsAg 对HBV 转基因小鼠T 细胞免疫调节的研究

目的:研究大剂量HBsAg对HBV转基因小鼠其T细胞免疫效果的影响。方法:用大剂量血源性HBsAg免疫HBV转基因小鼠,采用ELISA方法观察转基因小鼠所诱生的HBsAg特异性Th1类细胞因子的水平,ELISPOT方法检测不同免疫方案对小鼠HBsAg特异性分泌IFN-γT细胞数量的影响,同时检测对小鼠淋巴细胞增殖的影响。结果:HBsAg组免疫后脾细胞产生的Th1类细胞因子(IFN-γ、IL-2)、HBsAg特异性分泌IFN-γT细胞及T细胞增殖水平较对照组显著增加(P<0.05)。结论:大剂量的HBs-Ag可以诱导乙肝转基因小鼠产生高水平Th1类细胞因子并打破免疫耐受。     

Phytophthora gemini sp. nov., a new species isolated from the halophilic plant Zostera marina in the Netherlands

Eight strains belonging to the Oomycete genus Phytophthora were isolated from Zostera marina (seagrass) in The Netherlands over the past 25 y. Based on morphology, isozymes, temperature-growth relationships and ITS sequences, these strains were found to belong to two different Phytophthora species. Five strains, four of them isolated from rotting seeds and one isolated from decaying plants, could not be assigned to a known species and hence belong to a new species for which we propose the name Phytophthora gemini sp. nov. Three strains were isolated from decaying plants and were identified as Phytophthora inundata, thereby expanding the known habitat range of this species from fresh to brackish-saline areas. The possible role of both Phytophthora species in the decline of Z. marina in The Netherlands and the evolutionary significance of the presence of Phytophthora species in marine environments are discussed.     

Adverse events of interferon beta-1a: a prospective multi-centre international ICH-GCP-based CRO-supported external validation study in daily practice

Background

Due to methodological shortcomings the available post-registration data on the adverse events (AEs) occurring in interferon beta-1a (INFb-1a)-treated patients fail to adequately validate phase III data and only partially inform on safety in daily practice. We assessed AEs in relapsing remitting multiple sclerosis (RRMS) patients treated with intramuscular (IM) INFb-1a in daily practice using data quality assurance measures similar to those in phase III trials.

Methods

A prospective, International Conference on Harmonization (ICH) - Good Clinical Practice (GCP)-based, clinical research organization (CRO)-supported study in 36 practices in the Netherlands, Belgium, the United Kingdom and Luxembourg. During 24 months after start of IM INFb-1a treatment 275 RRMS patients were assessed for AEs'' severity (mild, moderate, severe) and relationship to treatment (not, unlikely, likely, definite). Data were compared with those reported in the pivotal phase III trial.

Findings

75.3% of the patients experienced one or more AEs that were likely or definitely related to INFb-1a. Of all AEs 40.5% were likely or definitely treatment-related; 68.5% of these were mild, and 3% severe. 6.6% of the patients discontinued treatment because of an AE. Compared to the pivotal phase III trial, we found statistically significantly lower incidences for most of the common AEs: headache, muscle ache, fatigue, fever, chills, nausea. One patient died following two cerebral vascular events in study month 22, both AEs were assessed as not related to INFb-1a.

Conclusion

Three out of four RRMS patients treated with IM INFb-1a in daily practice experience treatment-related AEs, most of these being mild. Our data externally validate the favorable phase III safety profile of IM INFb-1a and suggest that the real-life incidence of treatment-related AEs is less than reported in the pivotal phase III trial. Larger studies are needed to detect rare, potentially hazardous AEs of IM INFb-1a.     

Morphogenesis in Isolated Microspore Cultures of <Emphasis Type="Italic">Brassica juncea</Emphasis>

Androgenesis is a phenomenon in which microspores are made to bypass the sexual pathway and follow the sporophytic mode of development to generate new plants without the intervention of fertilization under specialized in vitro conditions. Microspore culture provides an ideal system, with a large, relatively uniform population of haploid cells, for use in mutant selection, genetic transformation and in studies on the molecular mechanism of induction of androgenesis and embryogenesis. This paper involves a study on establishing a reproducible and efficient protocol for microspore embryogenesis in various varieties of Brassica juncea. The genotype had a pronounced effect on androgenic response in microspore cultures. The cultivar Rajat exhibited the most response, producing around 3500 embryos/100 buds. The microspores of B. juncea cv. PR-45 from ed plants maintained at a day/night temperature of 10 °C/5 °C form embryos with suspensors with varied morphology. The microspore embryos germinated to produce plants with frequencies. These plants exhibited 52% survival and 74% fertility.     

Callus induction and <Emphasis Type="Italic">de novo</Emphasis> regeneration from callus in Guar (<Emphasis Type="Italic">Cyamopsis tetragonoloba</Emphasis>)

Guar (Cyamopsis tetragonoloba L. Taub) is a drought tolerant and multipurpose grain legume cash crop grown primarily under rainfed conditions in several countries. The effect of various growth regulators and their combinations on a variety of explants, namely the embryo, cotyledons, cotyledonary nodes, shoot tip and hypocotyle, has been studied and an efficient system for callus induction and regeneration from callus has been developed. It was established that Murashige and Skoogs culture medium containing 2,4-dichlorophenoxyacetic acid (10.0M) in combination with 6-benzylaminopurine (5.0M) with embryo or cotyledon explants is most suitable for induction of green and friable morphogenic callus, with a range of 82.5–95% of cultured explants responding to callus induction. Efficient de novo shoot regeneration was achieved by culturing the callus obtained on this medium on Murashige and Skoogs medium containing 1-naphthlenacetic acid (13.0M) in combination with 6-benzylaminopurine (5.0M) with a range of 82.1–88.4% of callus clumps producing 20–25 shoots. In vitro rooting of cultured shoots was obtained on half-salt concentration of Murashige and Skoogs culture medium supplied with indole-3-butyric acid (5.0M) on which 82–90% of cultured shoots produced healthy roots. The in vitro regenerated plants were grown to pod setting and subsequent maturity under greenhouse conditions.     

Drought Induces Oxidative Stress and Enhances the Activities of Antioxidant Enzymes in Growing Rice Seedlings

When rice seedlings grown for 10 and 20 days were subjected to in vitro drought stress of −0.5 and −2.0 MPa for 24 h, an increase in the concentration of superoxide anion (O₂^.−), increased level of lipid peroxidation and a decrease in the concentration of total soluble protein and thiols was observed in stressed seedlings compared to controls. The concentration of H₂O₂ as well as ascorbic acid declined with imposition of drought stress, however glutathione (GSH) concentration declined only under severe drought stress. The activities of total superoxide dismutases (SODs) as well as ascorbate peroxidase (APX) showed consistent increases with increasing levels of drought stress, however catalase activity declined. Mild drought stressed plants had higher guaiacol peroxidase (GPX) and chloroplastic ascorbate peroxidase (c-APX) activity than control grown plants but the activity declined at the higher level of drought stress. The activities of enzymes involved in regeneration of ascorbate i.e. monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR) and glutathione reductase (GR) were higher in drought stressed plants compared to controls. Results suggest that drought stress induces oxidative stress in rice plants and that besides SOD, the enzymes of ascorbate-glutathione cycle, which have not been studied in detail earlier under stressful conditions, appear to function as important component of antioxidative defense system under drought stress.     

An inter-laboratory collaborative study by the Non-Genotoxic Carcinogen Study Group in Japan, on a cell transformation assay for tumour promoters using Bhas 42 cells

The Bhas promotion assay is a cell culture transformation assay designed as a sensitive and economical method for detecting the tumour-promoting activities of chemicals. In order to validate the transferability and applicability of this assay, an inter-laboratory collaborative study was conducted with the participation of 14 laboratories. After confirmation that these laboratories could obtain positive results with two tumour promoters, 12-O-tetradecanoylphorbol-13-acetate (TPA) and lithocholic acid (LCA), 12 coded chemicals were assayed. Each chemical was tested in four laboratories. For eight chemicals, all four laboratories obtained consistent results, and for two of the other four chemicals, only one of the four laboratories showed inconsistent results. Thus, the rate of consistency was high. During the study, several issues were raised, each of which were analysed step-by-step, leading to revision of the protocol of the original assay. Among these issues were the importance of careful maintenance of mother cultures and the adoption of test concentrations for toxic chemicals. In addition, it is suggested that three different types of chemicals show positive promoting activity in the assay. Those designated as T-type induced extreme growth enhancement, and included TPA, mezerein, PDD and insulin. LCA and okadaic acid belonged to the L-type category, in which transformed foci were induced at concentrations showing growth-inhibition. In contrast, M-type chemicals, progesterone, catechol and sodium saccharin, induced foci at concentrations with little or slight growth inhibition. The fact that different types of chemicals similarly induce transformed foci in the Bhas promotion assay may provide clues for elucidating mechanisms of tumour promotion.     

Cerebrospinal Fluid Catecholamine Levels in Japanese Encephalitis Patients with Movement Disorders

Norepinephrine and dopamine have important role in movement disorders but their role in movement disorders associated with Japanese encephalitis (JE) has not been evaluated. Therefore, in the present study, cerebrospinal fluid (CSF) catecholamine levels and its metabolites in JE patients with movement disorders were compared with those without JE. CSF was collected by lumbar puncture and analyzed by HPLC-ED. Norepinephrine, dopamine and homovanillic acid concentrations were significantly (P<0.005) lower in JE patients compared to control groups. Low levels of catecholamines in JE associated movement disorders compared to idiopathic Parkinson’s disease and other extrapyramidal symptoms may be due to severe structural damage to thalamus, basal ganglia and brainstem in JE patients as revealed by MRI findings.