<Emphasis Type="Italic">Pichia stipitis</Emphasis> xylose reductase helps detoxifying lignocellulosic hydrolysate by reducing 5-hydroxymethyl-furfural (HMF)

Background  

Pichia stipitis xylose reductase (Ps-XR) has been used to design Saccharomyces cerevisiae strains that are able to ferment xylose. One example is the industrial S. cerevisiae xylose-consuming strain TMB3400, which was constructed by expression of P. stipitis xylose reductase and xylitol dehydrogenase and overexpression of endogenous xylulose kinase in the industrial S. cerevisiae strain USM21.     

Surface structure changes of rat adipocytes during lypolysis stimulated by various lypolysis stimulated by various lypolytic agents

A qualitative and quantitative electron microscopic study was performed on rat adipocytes during stimulation of lipolysis by various agents. Scanning electron microscopy of control cells revealed a spherical cell with a textured glycocalyx surface exhibiting small irregular projections. Globular surface evaginations or protrusions measuring 8-18 μM in diameter were seen on cell hemispheres, and there was an average of one protrusion for every two hemispheres examined. Distribution analysis showed that 60 percent of the hemispheres had no protrusions, and 25, 10, and 5 percent of the hemispheres had one, two or three protrusions, respectively. Thin-section and freeze- fracture electron microscopy of the protrusions showed a small triglyceride droplet surrounded by a thin cytoplasmic rim that was continuous with the main cytoplasmic matrix. The glycocalyx coating and plasma membrane extended from the cell surface onto, and over, the protrusion. Scanning microscopy of cells stimulated by lipolytic agents, including epinephrine, adrenocorticotropic hormone, theophylline, and dibutyryl cyclic AMP, revealed a dose-dependent increase in the number of protrusions per cell hemisphere. Maximal concentrations of lipolytic hormones cuase an average 2.5-fold increase in the number of protrusions per hemisphere without changing the average size of the protrusions. Only 40 percent of the stimulated cell hemispheres exhibited no protrusions; over 15 percent of the cells contained three or more; and a number of the protrusions were multilobulate. Insulin prevented the increase in the number of protrusions and the change in distribution caused by the lipolytic hormones but did not prevent the increase caused by theophylline and dibutryl cyclic AMP. The data suggest that the protrusions are a structural feature of the cell and may be related to the lypolytic pathway. These observations may help explain some of the discrepant biochemical data relating to hormonal stimulation of lipolysis.     

Evolution of eutherian cytochrome c oxidase subunit II: heterogeneous rates of protein evolution and altered interaction with cytochrome c

Cytochrome c oxidase subunit II (COII), encoded by the mitochondrial genome, exhibits one of the most heterogeneous rates of amino acid replacement among placental mammals. Moreover, it has been demonstrated that cytochrome c oxidase has undergone a structural change in higher primates which has altered its physical interaction with cytochrome c. We collected a large data set of COII sequences from several orders of mammals with emphasis on primates, rodents, and artiodactyls. Using phylogenetic hypotheses based on data independent of the COII gene, we demonstrated that an increased number of amino acid replacements are concentrated among higher primates. Incorporating approximate divergence dates derived from the fossil record, we find that most of the change occurred independently along the New World monkey lineage and in a rapid burst before apes and Old World monkeys diverged. There is some evidence that Old World monkeys have undergone a faster rate of nonsynonymous substitution than have apes. Rates of substitution at four-fold degenerate sites in primates are relatively homogeneous, indicating that the rate heterogeneity is restricted to nondegenerate sites. Excluding the rate acceleration mentioned above, primates, rodents, and artiodactyls have remarkably similar nonsynonymous replacement rates. A different pattern is observed for transversions at four-fold degenerate sites, for which rodents exhibit a higher rate of replacement than do primates and artiodactyls. Finally, we hypothesize specific amino acid replacements which may account for much of the structural difference in cytochrome c oxidase between higher primates and other mammals.      

Relationships among msx gene structure and function in zebrafish and other vertebrates

The zebrafish genome contains at least five msx homeobox genes, msxA, msxB, msxC, msxD, and the newly isolated msxE. Although these genes share structural features common to all Msx genes, phylogenetic analyses of protein sequences indicate that the msx genes from zebrafish are not orthologous to the Msx1 and Msx2 genes of mammals, birds, and amphibians. The zebrafish msxB and msxC are more closely related to each other and to the mouse Msx3. Similarly, although the combinatorial expression of the zebrafish msx genes in the embryonic dorsal neuroectoderm, visceral arches, fins, and sensory organs suggests functional similarities with the Msx genes of other vertebrates, differences in the expression patterns preclude precise assignment of orthological relationships. Distinct duplication events may have given rise to the msx genes of modern fish and other vertebrate lineages whereas many aspects of msx gene functions during embryonic development have been preserved.      

Inhibition of Fungal Plant Pathogens by Synergistic Action of Chito-Oligosaccharides and Commercially Available Fungicides

Chitosan is a linear heteropolymer consisting of β 1,4-linked N-acetyl-D-glucosamine (GlcNAc) and D-glucosamine (GlcN). We have compared the antifungal activity of chitosan with DP_n (average degree of polymerization) 206 and F _A (fraction of acetylation) 0.15 and of enzymatically produced chito-oligosaccharides (CHOS) of different DP_n alone and in combination with commercially available synthetic fungicides, against Botrytis cinerea, the causative agent of gray mold in numerous fruit and vegetable crops. CHOS with DP_n in the range of 15–40 had the greatest anti-fungal activity. The combination of CHOS and low dosages of synthetic fungicides showed synergistic effects on antifungal activity in both in vitro and in vivo assays. Our study shows that CHOS enhance the activity of commercially available fungicides. Thus, addition of CHOS, available as a nontoxic byproduct of the shellfish industry, may reduce the amounts of fungicides that are needed to control plant diseases.     

Adding Content to Contacts: Measurement of High Quality Contacts for Maternal and Newborn Health in Ethiopia,North East Nigeria,and Uttar Pradesh,India

BackgroundFamilies in high mortality settings need regular contact with high quality services, but existing population-based measurements of contacts do not reflect quality. To address this, in 2012, we designed linked household and frontline worker surveys for Gombe State, Nigeria, Ethiopia, and Uttar Pradesh, India. Using reported frequency and content of contacts, we present a method for estimating the population level coverage of high quality contacts.ConclusionsMeasuring content of care to reflect the quality of contacts can reveal missed opportunities to deliver best possible health care.     

Phytochemistry and antiglycation activity of Aloe sinkatana Reynolds

A new anthraquinone along with 10 known compounds were isolated from the leaves of Aloe sinkatana Reynolds (Aloaceae), and their structures were elucidated as the new compound 2,8-dihydroxy-6-(hydroxymethyl)-1-methoxyanthracene-9,10-dione (1) and the known compounds Aloe-emodin (2), feralolide (3), 1-hydroxy-5-methoxy-3-methyl-9,10 dihydroanthracene 9,10-dione (4), β-sitosterol (5), β-sitosterol with glycosidic bond (6), microdontin (7), homoaloins A (8) and B (9) and aloins A (10) and B (11). Characterization of compounds 1–9 was based on spectral analyses and comparison with reported data, particularly the new compound 1 was identified by 1D- and 2D NMR, mass spectroscopic and X-ray crystallography analyses. Antiglycation activity of the extracts and isolated compounds were carried out using the hemoglobin-δ-gluconolactone and glucose–bovine serum albumin assays. The results obtained showed that MeOH and EtOAc extracts as well as compound 1 showed an inhibitory effect on early stage protein glycation. Compound 1 also showed significant inhibitory effects against glucose-induced advanced glycation end-products.     

Does service accessibility reduce socioeconomic differentials in maternity care seeking? Evidence from rural Bangladesh

Maternal mortality is a serious public health concern in Bangladesh. However, most deaths could be prevented through proper and timely care seeking and adequate management. Unfortunately, fewer than half of pregnant women in Bangladesh seek antenatal care, and only one in eight receive delivery care from medically trained providers. The specific objectives of this research are to examine the socioeconomic differentials of maternity care seeking, and to determine whether accessibility of health services reduces the socioeconomic differentials in maternity care seeking. A multi-level logistic regression method is employed to analyse longitudinal data collected from a sample of 1019 women from all over Bangladesh. The study finds significant socioeconomic disparities in both antenatal and delivery care seeking. Service accessibility, however, significantly reduces the socioeconomic differentials in delivery care seeking. Services need to be made accessible to reduce the inequality in maternity care seeking between rich and poor, empowered and non-empowered.