Immunomodulating activities of water-soluble exopolysaccharides obtained from submerged culture of Lentinus lepideus

Immunomodulating activities of water-soluble exopolysaccharides (LL-EX) obtained from submerged mycelial culture of Lentinus lepideus were studied and their effectiveness was compared with lipopolysaccharide (LPS). The influence of the LL-EX on macrophage cellular lysosomal enzyme activity was to stimulate up to 267%, 392%, and 464% at the level of 10, 50, and 100 mug/ml, respectively. When the LL-EX was further fractionated into LL-Fr.I and Fr.II by Sepharose CL-6B gel chromatography, the cellular lysosomal enzyme activity of LL-Fr.II (2.1- fold) was higher than Fr.I (1.2-fold). Moreover, both LL-Fr.I and Fr.II stimulated the cytokines IL-1beta, TNF-alpha, and IL-6 in macrophages. In mixed lymphocyte reaction, LL-Fr.I and Fr.II enhanced the splenocyte proliferation up to 1.2-fold and 1.4-fold (50 mg/ml), respectively, stimulating only T lymphocytes. The fractions of LL-EX not show any direct toxicity against human gastric adenocarcinoma cell (AGS). The molecular masses of LL-Fr.I and Fr.II were estimated to be about 1,986 kDa and 21 kDa, respectively. The total sugar and protein contents of the two fractions were 84.97% and 69.88% and 15.03% and 30.12%, respectively. The sugar and amino acid compositions of the LL-Fr.I and Fr.II were also analyzed in detail.     

Variation of Cu and Zn Fractionation and Mobility in Mine Tailing Soil Due to Experimental Leaching

The aims of this paper were to assess the variation of heavy metal (Cu and Zn) fractions and mobility in abandoned metal mine soil due to batch experimental leaching. Four solutions with different pH levels were used in the experiments. The total and fractional concentrations of heavy metals in untreated and leached soils were determined. The Kruskal–Wallis test was applied to verify the differences in the Cu and Zn distribution in soils before and after leaching. In order to assess the mobility of heavy metals, mobility factors (MFs) were calculated. The research results showed that the original/untreated soil was mainly of a sandy texture and acidic in character. After batch leaching for 7 days, the distribution of heavy metals was dominant in the residual fraction (F5). Heavy metal fractions in F1, F2, F3, and F5 showed a decreasing trend, but an increasing trend in F4 was observed. Among the solutions applied having different pH values, HCl (pH 3) illustrated the strongest effect on decreasing heavy metals in short-term mobile fractions (F1 and F2). The MF of Zn decreased more than that of Cu after 7-day batch leaching.     

Conformational dynamics of the human propeller telomeric DNA quadruplex on a microsecond time scale

The human telomeric DNA sequence with four repeats can fold into a parallel-stranded propeller-type topology. NMR structures solved under molecular crowding experiments correlate with the crystal structures found with crystal-packing interactions that are effectively equivalent to molecular crowding. This topology has been used for rationalization of ligand design and occurs experimentally in a number of complexes with a diversity of ligands, at least in the crystalline state. Although G-quartet stems have been well characterized, the interactions of the TTA loop with the G-quartets are much less defined. To better understand the conformational variability and structural dynamics of the propeller-type topology, we performed molecular dynamics simulations in explicit solvent up to 1.5 μs. The analysis provides a detailed atomistic account of the dynamic nature of the TTA loops highlighting their interactions with the G-quartets including formation of an A:A base pair, triad, pentad and hexad. The results present a threshold in quadruplex simulations, with regards to understanding the flexible nature of the sugar-phosphate backbone in formation of unusual architecture within the topology. Furthermore, this study stresses the importance of simulation time in sampling conformational space for this topology.     

Indigenous Vibrio cholerae strains from a non-endemic region are pathogenic

Of the 200+ serogroups of Vibrio cholerae, only O1 or O139 strains are reported to cause cholera, and mostly in endemic regions. Cholera outbreaks elsewhere are considered to be via importation of pathogenic strains. Using established animal models, we show that diverse V. cholerae strains indigenous to a non-endemic environment (Sydney, Australia), including non-O1/O139 serogroup strains, are able to both colonize the intestine and result in fluid accumulation despite lacking virulence factors believed to be important. Most strains lacked the type three secretion system considered a mediator of diarrhoea in non-O1/O13 V. cholerae. Multi-locus sequence typing (MLST) showed that the Sydney isolates did not form a single clade and were distinct from O1/O139 toxigenic strains. There was no correlation between genetic relatedness and the profile of virulence-associated factors. Current analyses of diseases mediated by V. cholerae focus on endemic regions, with only those strains that possess particular virulence factors considered pathogenic. Our data suggest that factors other than those previously well described are of potential importance in influencing disease outbreaks.     

Sequencing approaches in cancer treatment

Use of sequencing approaches is an important aspect in the field of cancer genomics, where next‐generation sequencing has already been utilized for targeting oncogenes or tumour‐suppressor genes, that can be sequenced in a short time period. Alterations such as point mutations, insertions/deletions, copy number alterations, chromosomal rearrangements and epigenetic changes are encountered in cancer cell genomes, and application of various NGS technologies in cancer research will encounter such modifications. Rapid advancement in technology has led to exponential growth in the field of genomic analysis. The $1000 Genome Project (in which the goal is to sequence an entire human genome for $1000), and deep sequencing techniques (which have greater accuracy and provide a more complete analysis of the genome), are examples of rapid advancements in the field of cancer genomics. In this mini review, we explore sequencing techniques, correlating their importance in cancer therapy and treatment.     

Glucolipotoxicity Impairs Ceramide Flow from the Endoplasmic Reticulum to the Golgi Apparatus in INS-1 β-Cells

Accumulating evidence suggests that glucolipotoxicity, arising from the combined actions of elevated glucose and free fatty acid levels, acts as a key pathogenic component in type II diabetes, contributing to β-cell dysfunction and death. Endoplasmic reticulum (ER) stress is among the molecular pathways and regulators involved in these negative effects, and ceramide accumulation due to glucolipotoxicity can be associated with the induction of ER stress. Increased levels of ceramide in ER may be due to enhanced ceramide biosynthesis and/or decreased ceramide utilization. Here, we studied the effect of glucolipotoxic conditions on ceramide traffic in INS-1 cells in order to gain insights into the molecular mechanism(s) of glucolipotoxicity. We showed that glucolipotoxicity inhibited ceramide utilization for complex sphingolipid biosynthesis, thereby reducing the flow of ceramide from the ER to Golgi. Glucolipotoxicity impaired both vesicular- and CERT-mediated ceramide transport through (1) the decreasing of phospho-Akt levels which in turn possibly inhibits vesicular traffic, and (2) the reducing of the amount of active CERT mainly due to a lower protein levels and increased protein phosphorylation to prevent its localization to the Golgi. In conclusion, our findings provide evidence that glucolipotoxicity-induced ceramide overload in the ER, arising from a defect in ceramide trafficking may be a mechanism that contributes to dysfunction and/or death of β-cells exposed to glucolipotoxicity.     

Microencapsulation of live probiotic bacteria

Scientific research regarding the use of live bacterial cells for therapeutic purposes has been rapidly growing over the years and has generated considerable interest to scientists and health professionals. Probiotics are defined as essential live microorganisms which, when administered in adequate amounts, confer a health benefit on the host. Due to considerable beneficial health effects, these microorganisms are increasingly incorporated into the dairy products; however, many reports demonstrated their poor survival and stability. Their survival in the gastrointestinal (GI) tract is also questionable. To overcome these problems, microencapsulation techniques are currently receiving considerable attention. This review describes the importance of live probiotic bacterial microencapsulation using an alginate microparticulate system and presents the potentiality of various coating polymers such as chitosan and polylysine for improving the stability of this microencapsulation.     

Rural-urban migration and child survival in urban Bangladesh: are the urban migrants and poor disadvantaged?

This paper analyses the levels and trends of childhood mortality in urban Bangladesh, and examines whether children's survival chances are poorer among the urban migrants and urban poor. It also examines the determinants of child survival in urban Bangladesh. Data come from the 1999-2000 Bangladesh Demographic and Health Survey. The results indicate that, although the indices of infant and child mortality are consistently better in urban areas, the urban-rural differentials in childhood mortality have diminished in recent years. The study identifies two distinct child morality regimes in urban Bangladesh: one for urban natives and one for rural-urban migrants. Under-five mortality is higher among children born to urban migrants compared with children born to life-long urban natives (102 and 62 per 1000 live births, respectively). The migrant-native mortality differentials more-or-less correspond with the differences in socioeconomic status. Like childhood mortality rates, rural-urban migrants seem to be moderately disadvantaged by economic status compared with their urban native counterparts. Within the urban areas, the child survival status is even worse among the migrant poor than among the average urban poor, especially recent migrants. This poor-non-poor differential in childhood mortality is higher in urban areas than in rural areas. The study findings indicate that rapid growth of the urban population in recent years due to rural-to-urban migration, coupled with higher risk of mortality among migrant's children, may be considered as one of the major explanations for slower decline in under-five mortality in urban Bangladesh, thus diminishing urban-rural differentials in childhood mortality in Bangladesh. The study demonstrates that housing conditions and access to safe drinking water and hygienic toilet facilities are the most critical determinants of child survival in urban areas, even after controlling for migration status. The findings of the study may have important policy implications for urban planning, highlighting the need to target migrant groups and the urban poor within urban areas in the provision of health care services.     

Development of ARMS-PCR assay for genotyping of Pro12Ala SNP of PPARG gene: a cost effective way for case–control studies of type 2 diabetes in developing countries

Type 2 diabetes (T2D) is a prevalent metabolic disorder across the globe. Research is underway on various aspects including genetics to understand and control the global epidemic of diabetes. Recently, several SNPs in various genes have been associated with T2D. These association studies are mainly carried out in the developed countries through Genome Wide Association Scans, with follow-up replication/validation studies by high-throughput genotyping techniques (e.g. Taqman Technology). Although, similar studies could be conducted in developing countries, however, the limiting factors are the associated cost and expertise. These factors hamper research into the genetic association and replication studies from low-income countries to figure out the role of putatively associated SNPs in diabetes. Although, there are several SNP detection methods (e.g. Taqman assay, Dot-blot, PCR-RFLP, DGGE, SSCP) but these are either expensive or labor intensive or less sensitive. Hence, our aim was to develop a low-cost method for the validation of PPARG (Pro12Ala, CCA>GCA) SNP (rs1801282) for its association with T2D. Here, we developed a cost-effective and rapid amplification refractory mutation specific-PCR (ARMS-PCR) method for this SNP detection. We successfully genotyped PPARG SNPs (Pro12Ala) in human samples and the validity of this method was confirmed by DNA sequencing of a few representative samples for the three different genotypes. Furthermore, ARMS-PCR was applied to T2D patients and control samples for the screening of this SNP.     

Exogenous sodium nitroprusside and glutathione alleviate copper toxicity by reducing copper uptake and oxidative damage in rice (Oryza sativa L.) seedlings

Nitric oxide (NO) and glutathione (GSH) regulate a variety of physiological processes and stress responses; however, their involvement in mitigating Cu toxicity in plants has not been extensively studied. This study investigated the interactive effect of exogenous sodium nitroprusside (SNP) and GSH on Cu homeostasis and Cu-induced oxidative damage in rice seedlings. Hydroponically grown 12-day-old seedlings were subjected to 100 μM CuSO₄ alone and in combination with 200 μM SNP (an NO donor) and 200 μM GSH. Cu exposure for 48 h resulted in toxicity symptoms such as stunted growth, chlorosis, and rolling in leaves. Cu toxicity was also manifested by a sharp increase in lipoxygenase (LOX) activity, lipid peroxidation (MDA), hydrogen peroxide (H₂O₂), proline (Pro) content, and rapid reductions in biomass, chlorophyll (Chl), and relative water content (RWC). Cu-caused oxidative stress was evident by overaccumulation of reactive oxygen species (ROS; superoxide (O₂ ^?–) and H₂O₂). Ascorbate (AsA) content decreased while GSH and phytochelatin (PC) content increased significantly in Cu-stressed seedlings. Exogenous SNP, GSH, or SNP?+?GSH decreased toxicity symptoms and diminished a Cu-induced increase in LOX activity, O₂ ^?–, H₂O₂, MDA, and Pro content. They also counteracted a Cu-induced increase in superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR), monodehydroascorbate reductase (MDHAR), and glyoxalase I and glyoxalase II activities, which paralleled changes in ROS and MDA levels. These seedlings also showed a significant increase in catalase (CAT), glutathione peroxidase (GPX), dehydroascorbate reductase (DHAR), glutathione S-transferase (GST) activities, and AsA and PC content compared with the seedlings stressed with Cu alone. Cu analysis revealed that SNP and GSH restricted the accumulation of Cu in the roots and leaves of Cu-stressed seedlings. Our results suggest that Cu exposure provoked an oxidative burden while reduced Cu uptake and modulating the antioxidant defense and glyoxalase systems by adding SNP and GSH play an important role in alleviating Cu toxicity. Furthermore, the protective action of GSH and SNP?+?GSH was more efficient than SNP alone.