Evaluation of the medicinal potentials of the methanol extracts of the leaves and stems of Halleria lucida

The medicinal potentials of the methanol extracts of the leaves and stems of Halleria lucida (Scrophulariaceae) were evaluated by assessing their antibacterial and antioxidant properties in vitro using standard procedures. The antioxidant activities of methanol extract of the leaves as determined by the ABTS, DPPH, proanthocyanidins and total flavonoids were higher than that of the stem. On the other hand, the total phenols, the flavonoids and the FRAP contents of the stem were higher than that of the leaves. The extracts however showed poor activity against both Gram-positive and Gram-negative bacteria. The methanol extract of the stem showed activities against Bacillus cereus and Staphylococcus epidermidis at MIC of 1.0 mg/ml. The methanol extract of the leaves did not show activity against any of the organisms used in this study. This study has to some extent validated the medicinal potential of the leaves and stems of H. lucida.     

Electrophilic alpha-thiocyanation of chiral and achiral N-acyl imides. A convenient route to 5-substituted and 5,5-disubstituted 2,4-thiazolidinediones

Electrophilic alpha-thiocyanation of N-acyl carboximides using N-thiocyanatosuccinimide and hydrolytic cyclization of the adducts affords 5-substituted and 5,5-disubstituted 2,4-thiazolidinediones in good overall yields. Alpha-thiocyanation of chiral N-acyl carboximides proceeds with excellent diastereoselectivity, although partial racemization occurs during subsequent cyclization.     

三氧化二砷对食管癌细胞增殖和热休克蛋白70表达的影响

目的：研究三氧化二砷（As2O3）对食管癌细胞增殖和热休克蛋白70（HSP70）表达的影响。方法：通过相差显微镜、流式细胞术、免疫细胞化学染色和免疫印迹分析等方法观察As2O3对人食管癌细胞株EC1的作用效果和作用机制。结果：与对照组相比,经2μmol/L和5μmol/Las2O3作用的细胞出现明显的生长抑制,G2/M期细胞比例增加;2μmol/Las2O3作用48h后经Ecl细胞HSP70（heat shock protein70）及HSC70(heat shock cognate protein70)表达均增加。结论：As2O3诱导食管癌细胞G2/M期阻滞抑制细胞增殖和生长;HSP70的升高是细胞对As2O3作用后出现的应激反应,并与细胞周期阻滞相关。     

The heterotrophic eubacterial and archaeal co-inhabitants of the halophilic Dunaliella salina in solar salterns fed by Bay of Bengal along south eastern coast of India

Halophilic microbes are studied to understand the metabolic pathways adopted by organisms in such extreme environment and for their biotechnological exploitation. In thallosohaline environments worldwide, the autotrophic alga Dunaliella salina Teodoresco is omnipresent, but it is being recently realised that the heterotrophic components vary in different regions. The unexplored eastern coastline of India abutted by Bay of Bengal was investigated for the heterotrophic halophilic microbes in this region. The waters in the salterns – replicas of natural hyper-saline water bodies of that region, were collected at four sites along 650 km of the coastal belt. In cultures set up from these waters, green and pink colonies were observed. The green colonies were found to be those of D. salina while the pink colonies were of heterotrophs. To identify the heterotrophic microbes, light microscopy, 16S rRNA typing and pigment profiling through spectrophotometry and HPLC were done. The cells in pink colonies were rod shaped. 16S rRNA typing of cells in these colonies detected the presence of Halomonas sp. – a eubacterium. The pigment profile of cells in pink cultures matched that of the archaea – Halobacterium; bacterioruberin derivatives were found. Thus, it was concluded that Halomonas and Halobacterium spp. are among the co-inhabitant heterotrophs of D. salina. Cultures of D. salina established from these salterns showed the typical three colours seen in the ponds of different sub-plots of salterns. They were green until 30 days, turning dark orange by 60 days and pink when 90 day old. In the 90 day old cultures, innumerable rod shaped cells were found. These cells were similar to the cells of the waters from the ponds of pink sub-plots of salterns and the pink colonies established from saltern waters in the laboratory. In the old (90 days) laboratory cultures of D. salina, the glycerol and proteins released from degenerating cells and the increase in salt concentration to super saturation levels due to evaporation of water in the medium led to the gregarious appearance of the heterotrophs – the co-inhabitants in natural environment.     

Heterologous expression of Brassica juncea microsomal ω-3 desaturase gene (BjFad3) improves the nutritionally desirable ω-6:ω-3 fatty acid ratio in rice bran oil

Rice bran oil (RBO), being naturally rich in antioxidants, is currently regarded as one of the health-beneficial edible oils. However, the RBO has essential linoleic acid (ω-6, C18:2) and α-linolenic acid (ω-3, C18:3) in nutritionally disproportionate level (~25:1), contrary to the WHO/FAO’s recommendation of ~5:1. Among few naturally occurring C18:3 enriched oil-seeds, Brassica juncea (Indian mustard) has almost equal proportion of ω-6 and ω-3 fatty acids in its oil due to the activity of microsomal ω-3 desaturase (Fad3), which converts C18:2–C18:3. Therefore, the full length Fad3 coding DNA sequence (CDS) was isolated from the developing seeds of B. juncea, functionally characterized and heterologously expressed for the nutritional enhancement of RBO. Sequence analysis revealed that the 1,134 bp long BjFad3 CDS corresponds to a polypeptide of 377 amino acids, which is highly (85–95 %) homologous to other known Fad3 enzymes of plant kingdom. The BjFad3 gene was initially characterized in transgenic tobacco to establish its linoleate desaturase activity. Thereafter, rice bran-specific expression of the BjFad3 was carried out to alter the fatty acid profile of RBO. Several independent transgenic lines of tobacco and rice plants were developed by Agrobacterium-mediated transformation. Standard molecular biological techniques were used to confirm the transgene integration in the respective genomes and subsequent in planta expression. The BjFad3 transgene expression correlated to the significant increase in C18:3 fatty acid content (up to tenfold) in both tobacco seed oil and RBO, and thereby improving the nutritionally desirable ω-6:ω-3 ratio (~2:1) in one of the transgenic rice lines.     

Tetrapod phylogeny inferred from 18S and 28S ribosomal RNA sequences and a review of the evidence for amniote relationships [published erratum appears in Mol Biol Evol 1991 May;8(3):398]

The 18S ribosomal RNAs of 21 tetrapods were sequenced and aligned with five published tetrapod sequences. When the coelacanth was used as an outgroup, Lissamphibia (living amphibians) and Amniota (amniotes) were found to be statistically significant monophyletic groups. Although little resolution was obtained among the lissamphibian taxa, the amniote sequences support a sister-group relationship between birds and mammals. Portions of the 28S ribosomal RNA (rRNA) molecule in 11 tetrapods also were sequenced, although the phylogenetic results were inconclusive. In contrast to previous studies, deletion or down- weighting of base-paired sites were found to have little effect on phylogenetic relationships. Molecular evidence for amniote relationships is reviewed, showing that three genes (beta-hemoglobin, myoglobin, and 18S rRNA) unambiguously support a bird-mammal relationship, compared with one gene (histone H2B) that favors a bird- crocodilian clade. Separate analyses of four other genes (alpha- crystallin A, alpha-hemoglobin, insulin, and 28S rRNA) and a combined analysis of all sequence data are inconclusive, in that different groups are defined in different analyses and none are strongly supported. It is suggested that until sequences become available from a broader array of taxa, the molecular evidence is best evaluated at the level of individual genes, with emphasis placed on those studies with the greatest number of taxa and sites. When this is done, a bird-mammal relationship is most strongly supported. When regarded in combination with the morphological evidence for this association, it must be considered at least as plausible as a bird-crocodilian relationship.      

Anther development and the orientation of the interchange quadrivalent in pearl millet

The effects of developmental stage of the anther, ageing of the plant, inbreeding and season on meiotic segregation of an interchange chain quadrivalent were studied in pearl millet, Pennisetum americanum (L.) Leeke. The frequency of adjacent orientation (and segregation) increased with developmental stage of the anther, independent of other factors. Plant age and degree of inbreeding had no demonstrable effects, but there was an indication that high temperature favoured adjacent orientation. Chromosome contraction as measured by change in chromosome length appeared to be negligible during metaphase-anaphase. Therefore, increased adjacent orientation cannot readily be explained by metaphase reorientation resulting from the straightening of chromosomes caused by an increase in their rigidity. It is probable that the unoriented or mal-oriented quadrivalents observed regularly at early metaphase I continue to straighten out prior to their delayed orientation. When they finally orientate late in metaphase, their orientation will more likely be adjacent than alternate.     

Infectious salmon anaemia virus (ISAV) isolated from the ISA disease outbreaks in Chile diverged from ISAV isolates from Norway around 1996 and was disseminated around 2005, based on surface glycoprotein gene sequences

Background

All viruses in the family Bunyaviridae possess a tripartite genome, consisting of a small, a medium, and a large RNA segment. Bunyaviruses therefore possess considerable evolutionary potential, attributable to both intramolecular changes and to genome segment reassortment. Hantaviruses (family Bunyaviridae, genus Hantavirus) are known to cause human hemorrhagic fever with renal syndrome or hantavirus pulmonary syndrome. The primary reservoir host of Sin Nombre virus is the deer mouse (Peromyscus maniculatus), which is widely distributed in North America. We investigated the prevalence of intramolecular changes and of genomic reassortment among Sin Nombre viruses detected in deer mice in three western states.

Methods

Portions of the Sin Nombre virus small (S) and medium (M) RNA segments were amplified by RT-PCR from kidney, lung, liver and spleen of seropositive peromyscine rodents, principally deer mice, collected in Colorado, New Mexico and Montana from 1995 to 2007. Both a 142 nucleotide (nt) amplicon of the M segment, encoding a portion of the G2 transmembrane glycoprotein, and a 751 nt amplicon of the S segment, encoding part of the nucleocapsid protein, were cloned and sequenced from 19 deer mice and from one brush mouse (P. boylii), S RNA but not M RNA from one deer mouse, and M RNA but not S RNA from another deer mouse.

Results

Two of 20 viruses were found to be reassortants. Within virus sequences from different rodents, the average rate of synonymous substitutions among all pair-wise comparisons (π_s) was 0.378 in the M segment and 0.312 in the S segment sequences. The replacement substitution rate (π_a) was 7.0 × 10^-4 in the M segment and 17.3 × 10^-4 in the S segment sequences. The low π_a relative to π_s suggests strong purifying selection and this was confirmed by a Fu and Li analysis. The absolute rate of molecular evolution of the M segment was 6.76 × 10^-3 substitutions/site/year. The absolute age of the M segment tree was estimated to be 37 years. In the S segment the rate of molecular evolution was 1.93 × 10^-3 substitutions/site/year and the absolute age of the tree was 106 years. Assuming that mice were infected with a single Sin Nombre virus genotype, phylogenetic analyses revealed that 10% (2/20) of viruses were reassortants, similar to the 14% (6/43) found in a previous report.

Conclusion

Age estimates from both segments suggest that Sin Nombre virus has evolved within the past 37–106 years. The rates of evolutionary changes reported here suggest that Sin Nombre virus M and S segment reassortment occurs frequently in nature.