Mechanistic and kinetic evaluation of biosorption of reactive azo dyes by free,immobilized and chemically treated Citrus sinensis waste biomass

Sorption potential of Citrus sinensis biomass for reactive yellow 42 and reactive red 45 was investigated with variation of pH, biosorbent dose and dye concentration. Biosorbent was treated by organic and inorganic reagents of which acetic acid and acetonitrile enhanced the sorption capacities for reactive yellow 42 and reactive red 45, respectively. Sorption equilibrium was established within 60 min using free and chemically treated biosorbent, while prolonged to 120 min using immobilized biosorbent. Freundlich isotherm and pseudo-second-order rate law described best the sorption mechanism. FT-IR analysis of biosorbent revealed the presence of CO, CO, NH and OH groups on the surface of biosorbent. Desorption experiments were performed to regenerate the sorbent, making the process more economical and environment friendly.     

Methyl jasmonate alleviates arsenic-induced oxidative damage and modulates the ascorbate–glutathione cycle in oilseed rape roots

Methyl jasmonate (MJ) is an important plant growth regulator, involves in various physiological processes of plants. In the present study, role of MJ in tolerance to oilseed rape (Brassica napus L.) roots under arsenic (As) stress was investigated. The treatments were comprised of three MJ doses (0, 0.1, and 1 µM) and two levels of As (0 and 200 µM). Arsenic stress resulted in oxidative damage as evidenced by decreased root growth and enhanced reactive oxygen species and lipid peroxidation. However, plants treated with MJ decreased the H₂O₂ and O₂ ^·? contents in roots and have higher antioxidant activities. Importantly, results showed that MJ enhanced the redox states of AsA and GSH, and the related enzymes involved in the AsA–GSH cycle. Moreover, MJ also induced the secondary metabolites related enzymes (PAL and PPO) activities, under As stress. PAL and PPO expression was further increased by MJ application in the roots of B. napus under As stress. MJ also reduced the total As content compared with As alone treated plants. These findings suggest the role of MJ in mitigation of the As-induced oxidative damage by regulating AsA and GSH redox states and by reducing As uptake in both cultivars.     

High HIV Incidence among Persons Who Inject Drugs in Pakistan: Greater Risk with Needle Sharing and Injecting Frequently among the Homeless

Background

The incidence of HIV among persons who inject drugs (PWIDU) has fallen in many nations, likely due to successes of clean needle/syringe exchange and substance abuse treatment and service programs. However in Pakistan, prevalence rates for PWID have risen dramatically. In several cities, prevalence exceeded 20% by 2009 compared to a 2003 baseline of just 0.5%. However, no cohort study of PWID has ever been conducted.

Methods

We enrolled a cohort of 636 HIV seronegative PWID registered with three drop-in centers that focus on risk reduction and basic social services in Karachi. Recruitment began in 2009 (March to June) and PWID were followed for two years. We measured incidence rates and risk factors associated with HIV seroconversion.

Results

Incidence of HIV was 12.4 per 100 person-years (95% exact Poisson confidence interval [CI]: 10.3–14.9). We followed 474 of 636 HIV seronegative persons (74.5%) for two years, an annual loss to follow-up of <13 per 100 person years. In multivariable Cox regression analysis, HIV seroconversion was associated with non-Muslim religion (Adjusted risk ratio [ARR] = 1.7, 95%CI:1.4, 2.7, p = 0.03), sharing of syringes (ARR = 2.3, 95%CI:1.5, 3.3, p<0.0001), being homeless (ARR = 1.7, 95%CI:1.1, 2.5, p = 0.009), and daily injection of drugs (ARR = 1.1, 95%CI:1.0, 1.3, p = 0.04).

Conclusions

Even though all members of the cohort of PWID were attending risk reduction programs, the HIV incidence rate was very high in Karachi from 2009–2011. The project budget was low, yet we were able to retain three-quarters of the population over two years. Absence of opiate substitution therapy and incomplete needle/syringe exchange coverage undermines success in HIV risk reduction.     

Preferential HIV Infection of CCR6+ Th17 Cells Is Associated with Higher Levels of Virus Receptor Expression and Lack of CCR5 Ligands

Th17 cells are enriched in the gut mucosa and play a critical role in maintenance of the mucosal barrier and host defense against extracellular bacteria and fungal infections. During chronic human immunodeficiency virus (HIV) infection, Th17 cells were more depleted compared to Th1 cells, even when the patients had low or undetectable viremia. To investigate the differential effects of HIV infection on Th17 and Th1 cells, a culture system was used in which CCR6⁺ CD4⁺ T cells were sorted from healthy human peripheral blood and activated in the presence of interleukin 1β (IL-1β) and IL-23 to drive expansion of Th17 cells while maintaining Th1 cells. HIV infection of these cultures had minimal effects on Th1 cells but caused depletion of Th17 cells. Th17 loss correlated with greater levels of virus-infected cells and cell death. In identifying cellular factors contributing to higher susceptibility of Th17 cells to HIV, we compared Th17-enriched CCR6⁺ and Th17-depleted CCR6⁻ CD4 T cell cultures and noted that Th17-enriched CCR6⁺ cells expressed higher levels of α4β7 and bound HIV envelope in an α4β7-dependent manner. The cells also had greater expression of CD4 and CXCR4, but not CCR5, than CCR6⁻ cells. Moreover, unlike Th1 cells, Th17 cells produced little CCR5 ligand, and transfection with one of the CCR5 ligands, MIP-1β (CCL4), increased their resistance against HIV. These results indicate that features unique to Th17 cells, including higher expression of HIV receptors and lack of autocrine CCR5 ligands, are associated with enhanced permissiveness of these cells to HIV.     

Corrigendum to “Synthesis,structure-activity relationship and molecular docking studies of 3-O-flavonol glycosides as cholinesterase inhibitors” [Bioorg. Med. Chem. 26 (12) (2018) 3696–3706]

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Hyperactivation and thermostabilization of <Emphasis Type="Italic">Phanerochaete chrysosporium</Emphasis> lignin peroxidase by immobilization in xerogels

This is a continuation of our previous paper on production of lignin peroxidase (LiP) by Phanerochaete chrysosporium in solid substrate fermentation (SSF) medium of corncobs. The enzyme was purified by ammonium sulphate precipitation and ion-exchange fast protein liquid chromatography. Maximum yield of LiP was 13.7 U/gds (units per gram dry substrate) after 5 days of SSF with 70% moisture and 20% (v/w) inoculum. The approximate molecular mass of purified LiP, estimated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis, was 38 kDa. The pH and temperature optima for the LiP were 4 and 40°C, respectively. Immobilization of LiP in hydrophobic xerogels caused hyperactivation of LiP and enhanced its thermostability properties. The K _M and V _max values for immobilized LiP were 10.56 mg/ml and 16.67 μmol/min (120.49 U/mg of protein) as compared to 13 mg/ml and 11.76 μmol/min (85 U/mg of protein), respectively, for free LiP using veratryl alcohol as substrate.     

Chromatin 3D interaction analysis of the STARD10 locus unveils FCHSD2 as a regulator of insulin secretion

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Individual Nuclei Differ in Their Sensitivity to the Cytoplasmic Inducers of DNA Synthesis: Implications for the Origin of Cell Cycle Variability

Nuclei of multinucleate cells generally initiate DNA synthesis simultaneously, suggesting that the timing of DNA synthesis depends upon the appearance of a cytoplasmic signal. In contrast, intact nuclei from quiescent mammalian cells initiate DNA synthesisasynchronouslyin cell-free extracts ofXenopuseggs, despite the common environment. Here we show that the two nuclei of permeabilized binucleate cells enter DNA synthesis coordinately in egg extracts, as they doin vivo,with different pairs of nuclei initiating replication at different times. This indicates that the two nuclei of a binucleate cell are identical in their sensitivity to the inducers of DNA synthesis in egg extracts; this sensitivity varies in general between the nuclei of unrelated cells. The asynchrony of DNA synthesis shown by unrelated nuclei in egg extracts is therefore not an artifact of the cell-free system but a reflection of genuine differences preexisting within the intact cell. Evidence that these differences between nuclei are responsible for a substantial fraction of G₁variability in living cells is presented.     

3-Methylthiopropylamine and (R)-3-methylsulphinylpropylamine in Iberis amara

3-Methylthiopropylamine and (R)-3-methylsulphinylpropylamine have been isolated from Iberis amara and identified by PC, high voltage electropho