Exposure of soil microbial communities to chromium and arsenic alters their diversity and structure

Extensive use of chromium (Cr) and arsenic (As) based preservatives from the leather tanning industry in Pakistan has had a deleterious effect on the soils surrounding production facilities. Bacteria have been shown to be an active component in the geochemical cycling of both Cr and As, but it is unknown how these compounds affect microbial community composition or the prevalence and form of metal resistance. Therefore, we sought to understand the effects that long-term exposure to As and Cr had on the diversity and structure of soil microbial communities. Soils from three spatially isolated tanning facilities in the Punjab province of Pakistan were analyzed. The structure, diversity and abundance of microbial 16S rRNA genes were highly influenced by the concentration and presence of hexavalent chromium (Cr (VI)) and arsenic. When compared to control soils, contaminated soils were dominated by Proteobacteria while Actinobacteria and Acidobacteria (which are generally abundant in pristine soils) were minor components of the bacterial community. Shifts in community composition were significant and revealed that Cr (VI)-containing soils were more similar to each other than to As contaminated soils lacking Cr (VI). Diversity of the arsenic resistance genes, arsB and ACR3 were also determined. Results showed that ACR3 becomes less diverse as arsenic concentrations increase with a single OTU dominating at the highest concentration. Chronic exposure to either Cr or As not only alters the composition of the soil bacterial community in general, but affects the arsenic resistant individuals in different ways.     

Sulphur application improves the growth, seed yield and oil quality of canola

Sulphur (S) nutrition is very important for harvesting potential seed and oil yield of rapeseed. This study evaluated response of foliage applied thiourea on the performance of two canola cultivars Shiralee and Dunkeld. Sulphur was applied to soil (40 kg ha^?1) or foliage (500 and 1,000 mg L^?1) at rosette, bud initiation and flowering stages using elemental S or thiourea as source, respectively; no S application was taken as control. Among all the treatments, soil application of S improved the crop growth, yield and oil quality in both cultivars and was followed by foliar application of thiourea at 1,000 mg L^?1 compared with no application. Soil applied S and foliar thiourea (1,000 mg L^?1) delayed the flowering and maturity. Soil and foliar applied S significantly improved leaf area index, crop growth rate, net assimilation rate and chlorophyll contents. Plant height, number of branches, siliqua per plant, seed number per siliqua, 1,000-seed weight, biological and seed yield were also increased by soil applied S and foliage applied thiourea (1,000 mg L^?1). Nonetheless, improvement in harvest index, seed oil, protein and glucosinolate contents was only observed from foliage applied thiourea (1,000 mg L^?1). Response of cv. Shiralee to sulphur application was better than cv. Dunkeld. In conclusion, foliar applied thiourea (1,000 mg L^?1) can have potential to improve growth, yield and oil quality in canola and can be economically viable and attractive alternative source.     

The effect of alkaline phosphatase on the activation of glucocorticoid-receptor complexes in rat liver cytosol

Calf intestinal alkaline phosphatase was found to stimulate the rate of in vitro activation of rat liver glucocorticoid-receptor complexes. This effect was registered both at 0 and 25 degrees C and could be prevented by sodium molybdate. The resulting change in sedimentation behaviour (shift of sedimentation coefficient from 9.6 S to 4.8 S for molybdate-stabilized and alkaline phosphatase-treated complexes, respectively) was similar to that observed after heat activation.     

Attitude and awareness of public towards genetic testing in Riyadh,Saudi Arabia

The current study was designed to evaluate the attitude of the Saudi general population towards knowledge, perception and awareness about genetic testing. Using a convenience sampling technique, an online survey was used to collect the data. The survey consisted of 16 questions that covered basic demographics and several scenarios that assess subjects’ perceptions regarding genetic testing. Answering all questions was required for completing the survey. Among 333 subjects, 53.5% were male, 18.9% were married, and 99.4% were muslims. Around 75% has/will have a bachelor degree. About 59% were students. About 87% would consider genetic testing before marriage and similar percentage would not consider conceiving a child if the genetic screening indicated that there is 100% chance the child will be born with genetic disorder. Neither marital status (Single = 87.04%, married = 87.30% (P = 0.955)) nor gender (male = 85.96, female = 88.39 (P = 0.509)) affected the aforementioned decision. When subjects were asked if they would choose abortion knowing that the embryo has a severe genetic disorder, 62.7% answered yes. In general, 80.4% were willing to be recruited into a genetics study, married subjects were more reluctant to be recruited compared to singles (30% and 17% (P = 0.018) respectively). There was no difference between males and females in the decision of joining a genetic study. Also 78.4% supported creation of genetic disease database and family maps. 69.7% of the participants supported government enforcement of the genetic testing, 56.2% supported government-run facilities for Saudi citizens to have genetic tests. We conclude that married people were in favor of genetic testing than the single counterparts, secondly, single status people supported the idea of having genetic tests before their marriage they were supportive of the idea of the government taking a leading role in enforcing the genetic testing and creation of the genetic banks.     

Hook selectivity and catch efficiency in two sport fishing sectors in the Strait of Istanbul,Turkey: Classic handline fishing and Light Rock Fishing (LRF)

In this study, the efficiency of two fishing methods (a) traditional handline commonly used in the Strait of Istanbul and (b) light rock fishing (LRF), which is beginning to spread in recent years, were investigated by monthly sampling between September 2014 and September 2015. One classic handline fishing tackle and one LRF fishing tackle were used in the test fishing exercise. In addition, the effects of the hook sizes (numbers 6, 8 and 10) used in the handline fishery on the size selectivity for horse mackerels were also studied. Catches using both types of fishing gear were mainly composed of Trachurus mediterraneus (89.60%), Scorpeana porcus (5.12%), Sardina pilchardus (1.98%), Atherina boyeri (0.99%), Liza aurata (0.66%), Scorpaena scrofa (0.50%), Pomatomus saltatrix (0.33%), Sprattus sprattus (0.33%) and a few other species. The frequency distributions of horse mackerel caught using handlines and LRF were slightly different and ranged between 6.1–19.0 cm and 9.0–16.0 cm, respectively. Of all the handlines, LRF yielded the highest catch per unit effort (CPUE), 1.295 kg/10 hooks/hour. The log normal model selectivity curve gave the best fit for the T. mediterraneus by using the SELECT method. The modal lengths of horse mackerel caught by handline hook sizes no.10 and no. 8 hook were calculated as 13.4 cm and 17.7 cm, respectively. In addition, the spread values were determined with 3.58 and 4.74, respectively.     

X-ray crystal structure of Vibrio alkaline phosphatase with the non-competitive inhibitor cyclohexylamine

BackgroundPara-nitrophenyl phosphate, the common substrate for alkaline phosphatase (AP), is available as a cyclohexylamine salt. Here, we report that cyclohexylamine is a non-competitive inhibitor of APs.MethodsCyclohexylamine inhibited four different APs. Co-crystallization with the cold-active Vibrio AP (VAP) was performed and the structure solved.ResultsInhibition of VAP fitted a non-competitive kinetic model (K_m unchanged, V_max reduced) with IC₅₀ 45.3 mM at the pH optimum 9.8, not sensitive to 0.5 M NaCl, and IC₅₀ 27.9 mM at pH 8.0, where the addition of 0.5 M NaCl altered the inhibition to the level observed at pH 9.8. APs from E. coli and calf intestines were less sensitive to cyclohexylamine, whereas an Antarctic bacterial AP was similar to VAP in this respect. X-ray crystallography at 2.3 Å showed two binding sites, one in the active site channel and another at the surface close to dimer interface. Antarctic bacterial AP and VAP have Trp274 in common in their active-sites, that takes part in binding cyclohexylamine. VAP variants W274A, W274K, and W274H gave IC₅₀ values of 179 mM, 188 mM and 187 mM, respectively, at pH 9.8.ConclusionsThe binding of cyclohexylamine in locations at the dimeric interface and/or in the active site of APs may delay product release or reduce the rate of catalytic step(s) involving conformational changes and intersubunit communications.General significanceCyclohexylamine is a common chemical in industries and used as a counterion in substrates for alkaline phosphatase, a clinically important and common enzyme in the biosphere.     

Role of inflammatory mechanisms in pathogenesis of type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is characterized by progressive β‐cell dysfunctioning and insulin resistance. This article reviews recent literature with special focus on inflammatory mechanisms that provoke the pathogenesis of T2DM. We have focused on the recent advances in progression of T2DM including various inflammatory mechanisms that might induce inflammation, insulin resistance, decrease insulin secretion from pancreatic islets and dysfunctioning of β‐cells. Here we have also summarized the role of various pro‐inflammatory mediators involved in inflammatory mechanisms, which may further alter the normal structure of β‐cells by inducing pancreatic islet's apoptosis. In conclusion, it is suggested that the role of inflammation in pathogenesis of T2DM is crucial and cannot be neglected. Moreover, the insight of inflammatory responses in T2DM may provide a new gateway for the better treatment of diabetes mellitus. J. Cell. Biochem. 114: 525–531, 2013. © 2012 Wiley Periodicals, Inc.     

Coenzyme Q10-Loaded Fish Oil-Based Bigel System: Probing the Delivery Across Porcine Skin and Possible Interaction with Fish Oil Fatty Acids

Coenzyme Q10 (CoQ10) is a vitamin-like oil-soluble molecule that has anti-oxidant and anti-ageing effects. To determine the most optimal CoQ10 delivery vehicle, CoQ10 was solubilised in both water and fish oil, and formulated into hydrogel, oleogel and bigel. Permeability of CoQ10 from each formulation across porcine ear skin was then evaluated. Furthermore, the effects of the omega-3 fatty eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids from fish oil on skin permeation were investigated by means of nuclear magnetic resonance (NMR) and computerised molecular modelling docking experiments. The highest drug permeation was achieved with the bigel formulation that proved to be the most effective vehicle in delivering CoQ10 across the skin membrane due to a combination of its adhesive, viscous and lipophilic properties. Furthermore, the interactions between CoQ10 and fatty acids revealed by NMR and molecular modelling experiments likely accounted for skin permeability of CoQ10. NMR data showed dose-dependent changes in proton chemical shifts in EPA and DHA. Molecular modelling revealed complex formation and large binding energies between fatty acids and CoQ10. This study advances the knowledge about bigels as drug delivery vehicles and highlights the use of NMR and molecular docking studies for the prediction of the influence of drug–excipient relationships at the molecular level.     

Identification and evaluation of glutathione conjugate gamma-l-glutamyl-l-cysteine for improved drug delivery to the brain

Abstract

Glutathione (GU), an endogenous antioxidant tripeptide, is frequently transferred in the human brain through N-methyl-d-aspartate receptor (NMDAR), profusely expressed at the blood–brain barrier (BBB) junction. GU, also modifies the characteristics of tight junction proteins (occludin and claudin) at the site of BBB by depolarizing the enzyme, protein tyrosine phosphatase that manifests its usefulness for passive delivery of nanocarriers to the brain. GU, thus, represents itself as an ideal ligand for the surface decoration of nanocarriers to successfully administer them across the brain via receptor-mediated drug delivery pathway. Hence, we have employed here, in-silico approaches to identify the potential GU-like molecules, as appropriate ligand(s) for surface engineering of nanoconstruct with the purpose of attaining targeted drug delivery to the brain. Structure-based virtual screening methods was used to filter PubChem database for the identification of bioactive compounds with >95% structure similarity with GU. We have further screened the compounds against NMDAR using molecular docking approach. Top hits were selected based on their high binding affinities and selectivity towards NMDAR, and their binding pattern was analysed in detail. Finally, all atom molecular dynamics simulation for 100?ns was carried out on free NMDAR and in-presence of the selected GU-like compound, gamma-l-glutamyl-l-cysteine to evaluate complex stability and structural dynamics. In conclusion, gamma-l-glutamyl-l-cysteine may act as potential binding partner of NMDAR which can further be evaluated in drug delivery system to brain across the BBB.

Communicated by Ramaswamy H. Sarma