Exogenous Hydrogen Sulfide Protects SH-SY5Y Cells from OGD/RInduced Injury

BACKGROUND

Cerebral ischemia reperfusion (CIR) injury is the main pathological mechanism of ischemia stroke, and oxidative stress (OS) plays a vital role during the process of CIR. Recent studies have found that OS can activate MAPK pathway, which mainly functions as a mediator of cellular stresses. It revealed that H2S may exhibit multiple biological functions as a neuroprotector through protecting against OS-induced neuronal injury. But how H2S can attenuate ischemia/reoxygenation injury through MAPK signaling is not clear. The protective mechanism of exogenous hydrogen sulfide (H2S) on oxygen glucose deprivation/reoxygenation (OGD/R) at physiological doses in SH-SY5Y cells were investigated in this study.

METHODS

DCFH- DA probe is used to measure intracellular ROS, Real-time PCR and Western blot are used to detect the levels of p38 MAPK, ERK3 and Nrf2. CCK-8 is used to detect cell viability.

RESULTS

Comparing with the normal control group, the expressions of ERK3, p38MAPK and Nrf2 mRNA in other three groups were downregulated at the beginning of 24h. After 24h, the expressions of ERK3, p38MAPK and Nrf2 were upregulated significantly compared with the normal control group. When the cells were pretreated with 200μM NaHS at the beginning of 24h, the expressions of ERK3, p38MAPK and Nrf2 were decreased much more significantly than OGD/R and NaHS groups.

CONCLUSION

The present study demonstrated that exogenous H2S exerts a protective effect against OGD/R-induced injury by enhancing the activation of the ERK3, p38MAPK and Nrf2 mRNA.

"Even if you're HIV-positive there's life after if you take your medication": experiences of people on long-term ART in South Africa: a short report

South Africa's national antiretroviral treatment (ART) programme, initiated in 2004, is the largest HIV treatment programme in the world with an estimated 4.2 million people on ART. Today, an HIV diagnosis is no longer associated with certain death, but is rather a manageable chronic disease, with all HIV-positive patients now eligible to receive treatment. In this study, we explore patient experiences at the onset of the ART programme, including facilitators and barriers around decision-making along the HIV care cascade (HIV testing, ART initiation, retention, and adherence). We conducted twenty-four in-depth interviews among adults (≥18 years old) who initiated ART between April 2004 and March 2005 and were alive, on treatment at enrolment (October 2015-March 2016) at a large public-sector clinic in Johannesburg, South Africa. Data were analysed using a thematic analysis approach. Patients cited physical wellbeing, responsibility for raising children, supportive clinic staff and noticeable improvements in health on ART as key facilitators to continued care. In contrast, changing clinic conditions, fear of side-effects and stigma were mentioned as barriers. This study provides a unique lens through which to evaluate factors associated with long-term retention and adherence to ART at a crucial time in ART programming when more people will be initiating life-long treatment. We must continue to focus on supportive and empathetic clinic environments, more convenient ways to access medication for patients, and developing tools or interventions that continue to address the issues of stigma and discrimination and build the support networks for all those on treatment.

Altering the linker in processive GH5 endoglucanase 1 modulates lignin binding and catalytic properties

BACKGROUND

The non-productive adsorption of cellulases onto lignin in biomass is a key issue for the biofuel process economy. It would be helpful to reduce the inhibitory effect of lignin on enzymatic hydrolysis by engineering weak lignin-binding cellulases. Cellulase linkers are highly divergent in their lengths, compositions, and glycosylations. Numerous studies have revealed that linkers can facilitate optimal interactions between structured domains. Recently, efforts have focused on the contributions and mechanisms of carbohydrate-binding modules and catalytic domains that affect lignin affinity and processivity of cellulases, but our understanding of the effects of the linker regions on lignin adsorption and processivity of GH5 processive endoglucanases is still limited.

RESULTS

Eight GH5 endoglucanase 1 variants of varying length, flexibility, and sequence in the linker region were constructed. Their characteristics were then compared to the wild-type enzyme (EG1). Remarkably, significant differences in the lignin adsorption profiles and processivities were observed for EG1 and other variants. Our studies suggest that either the length or the specific amino acid composition of the linker has a prominent influence on the lignin-binding affinity of the enzymes. Comparatively, the processivity may depend primarily on the length of the linker and less so on the specific amino acid composition. EG1-ApCel5A, a variant with better performance in enzymatic hydrolysis in the presence of lignin, was obtained by replacing a longer, flexible linker. In total, up to between 28.2 and 30.1% more reducing sugars were generated from filter paper by EG1-ApCel5A in the presence of lignin compared to EG1.

CONCLUSIONS

Our results highlight the relevance of the linker region in the lignin adsorption and processivity of a processive endoglucanase. Our findings suggest that the linker region may be used as a target for the design of more active and weaker lignin-binding cellulases.

Expression and characterization of a 9-cis-epoxycarotenoid dioxygenase from Serratia sp. ATCC 39006 capable of biotransforming isoeugenol and 4-vinylguaiacol to vanillin

A 9-cis-epoxycarotenoid dioxygenase gene from Serratia sp. ATCC 39,006 (SeNCED) was overexpressed in soluble form in E.coli. SeNCED showed the maximum activity at 30 °C and pH 8.0, and it was stable relatively at range of pH 5-10 and temperature of 20 °C to 30 °C. SeNCED effectively catalyzes the side chain double bond cleavage of isoeugenol and 4-vinylguaiacol to vanillin. The kinetic constant Km values toward isoeugenol and 4-vinylguaiacol were 18.92 mM and 6.31 mM and Vmax values were 50.73 IU/g and 4.77 IU/g, respectively. Moreover, the SeNCED exhibited an excellent organic solvent tolerance and the enzyme activity was substantially improved at presence of 10% of trichloromethane. The produced vanillin was achieved at an around 0.53 g/L (3.47 mM) and 0.33 g/L (2.17 mM) after 8 h reaction at 4 mM of isoeugenol and 4-vinylguaiacol, respectively, using transformed Escherichia coli cells harboring SeNCED in the presence of trichloromethane.

Incident tuberculosis in HIV-positive children, adolescents and adults on antiretroviral therapy in South Africa

OBJECTIVE

To evaluate the association between age and incident tuberculosis (TB) among human immunodeficiency virus (HIV) infected patients receiving antiretroviral treatment (ART) in South Africa.

DESIGN

Prospective cohort analysis among HIV-infected patients initiating ART between April 2004 and April 2012. Generalized estimating equations (GEE) were used with modified Poisson regression clustered by treatment site as a function of sex, age, nucleoside reverse transcriptase inhibitor, CD4 count, hemoglobin levels and year of ART initiation. Cumulative incidence functions stratified by age and controlling for death as a competing risk were used to graphically display incident TB.

RESULTS

Although non-significant, GEE models showed that patients aged <1 year had a 40% increase in risk of TB compared to those aged 30-39.9 years. Results also showed that male patients, those with low CD4, those with low hemoglobin and those who initiated ART before 2010 were at increased risk of TB.

CONCLUSIONS

Our results show that patients aged <1 year, males, patients with low CD4 and those with low hemoglobin at ART initiation are at increased risk of incident TB in the first 24 months of ART. Given the known transmission risk factors for children living in households with a TB contact, reducing TB incidence in HIV-positive adults could substantially impact the risk of TB in young children.

Evaluation of different agricultural wastes for the production of fruiting bodies and bioactive compounds by medicinal mushroom Cordyceps militaris

BACKGROUND

In commercial production of Cordyceps militaris (a famous Chinese medicine), cereal grains are usually utilized as cultivation substrates. This study aimed to evaluate the efficiency of agricultural wastes as substitute materials in the low-cost production of C. militaris. Cottonseed shells (CS), corn cob particles (CCP), Italian poplar sawdusts (IPS) and substrates spent by Flammulina velutipes (SS) were employed to cultivate C. militaris, using rice medium as control.

RESULTS

CS and CCP were suitable for fruit body formation of C. militaris, with yields of 22 and 20 g per bottle respectively. Fruit bodies grown on CCP showed the highest levels of cordycepin and adenosine, up to 9.45 and 5.86 mg g^-1 respectively. The content of d-mannitol in fruit bodies obtained on CS was 120 mg g^-1 (80% of the control group), followed by that on CCP, 100 mg g^-1 . Fruit bodies cultivated on CCP displayed a high crude polysaccharide level of 26.9 mg g^-1 , which was the closest to that of the control group (34.5 mg g^-1 ).

CONCLUSION

CS and CCP are effective substrates for the production of fruit bodies and bioactive compounds by C. militaris. This study provides a new approach to decreasing the cost of C. militaris cultivation and dealing with these agricultural wastes. © 2016 Society of Chemical Industry.

Thermotolerant hemicellulolytic and cellulolytic enzymes from Eupenicillium parvum 4-14 display high efficiency upon release of ferulic acid from wheat bran

AIMS

To characterize the hemicellulolytic and cellulolytic enzymes from novel fungi, and evaluate the potential of novel enzyme system in releasing ferulic acid (FA) from biomass resource.

METHODS AND RESULTS

A hemicellulolytic and cellulolytic enzyme-producing fungus 4-14 was isolated from soil by Congo red staining method, and identified as Eupenicillium parvum based on the morphologic and molecular phylogenetic analysis. The optimum temperature of fungal growth was 37°C. Hemicellulolytic and cellulolytic enzymes were produced by this fungus in solid-state fermentation (SSF), and their maximum activities were 554, 385, 218, 2·62 and 5·25 U g(-1) for CMCase, xylanase, β-glucosidase, FPase and FAE respectively. These enzymes displayed the best catalytic ability at low pH values (pH 4·5-5·0). The optimum temperatures were 70°C, 70°C, 75°C and 55°C for CMCase, β-glucosidase, xylanase and FAE respectively. CMCase, xylanase and FAE were stable at different pHs or high temperature (60°C). Enzymatic hydrolysis experiment indicated that the maximum (76·8 ± 4)% of total alkali-extractable FA was released from de-starched wheat bran by the fungal enzyme system.

CONCLUSIONS

High activities of thermotolerant CMCase, β-glucosidase, xylanase and FAE were produced by the newly isolated fungus E. parvum 4-14 in SSF. The fungal enzyme system displayed high efficiency at releasing FA from wheat bran.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provides a new fungal strain for researches of novel hemicellulolytic and cellulolytic enzymes and will improve the bioconversion and utilization of agricultural by-products.

Population and function analysis of cultivable bacteria associated with spores of arbuscular mycorrhizal fungus Gigaspora margarita

This study was aimed to investigate the diversity and function of bacterial population associated with Gigaspora margarita spores. The fungus was propagated in sterilized sand/soil pots using alfalfa (Medicago sativa), grain sorghum (Sorghum bicolor), or maize (Zea mays) as host plants, or in sterilized vermiculite pots using alfalfa as host plants, respectively. Bacteria were isolated from the new-formed spores using diluted plate method, and typical bacterial isolates were identified according to 16S rRNA gene phylogenetic analysis. Total 43 bacterial isolates affiliated to three phyla and 23 genera were obtained. The spore-associated bacterial communities were obviously different among the four source spores, suggesting that plant species or substrates could influence the bacterial population. Bacillus and Streptomyces were most frequently associated with the fungal spores. Function analysis of these bacteria by plate tests, it was found that about 30.2% isolates stimulated the spore germination, five out of seven tested isolates improved the hyphal growth, total 57.5% of the tested isolates solubilized phosphorus at different levels, 15% isolates degraded chitin, and a few isolates suppressed the growth of Escherichia coli or Staphylococcus aureus. In pot experiment, three bacterial isolates (belonging to Curtobacterium, Ensifer, or Bacillus, respectively) displayed improvement effect on alfalfa growth and/or the colonization of roots by G. margarita.

Non-neutralizing epitopes induce robust hepatitis C virus (HCV)-specific antibody-dependent CD56+ natural killer cell responses in chronic HCV-infected patients

Natural killer (NK) cell-mediated antibody-dependent cellular cytotoxicity (NK-ADCC) is of considerable interest in viral infection. However, little is known about NK-ADCC responses in chronic hepatitis C virus (HCV) infection. In this study, impaired non-specific antibody-dependent CD56⁺ NK cell responses were observed in chronic HCV infection, as shown by decreased degranulation (extracellular CD107a expression) and interferon (IFN)-γ production in response to antibody-bound P815 cells. A peptide pool composed of epitopes recognized by anti-HCV-E1/E2 antibodies could induce pronounced HCV-specific antibody-dependent NK cell responses in sera from approximately half the chronic HCV carriers. Additionally, HCV-specific epitopes with the capacity to induce robust NK-ADCC activity were identified. Five linear NK-ADCC epitopes (aa211-aa217, aa384-aa391, aa464-aa475, aa544-aa551 and aa648-aa659 of the HCV envelope) were identified and do not overlap with putative linear neutralizing epitopes. This study revealed the dysfunctional characteristics of antibody-dependent CD56⁺ NK cell responses in chronic HCV carriers. The key non-neutralizing NK-ADCC epitopes identified in this study may act as new targets for immunological intervention.

Effects of dietary octacosanol supplementation on laying performance, egg quality, serum hormone levels, and expression of genes related to the reproductive axis in laying hens

This experiment was conducted to evaluate the effects of dietary octacosanol supplementation on laying performance, egg quality, serum hormone levels, and gene expression related to reproductive axis in laying hens to confirm the reproduction-promoting function of octacosanol. In total, 360 Hy-Line Brown (67-wk-old) laying hens were randomly assigned to one of three treatments with 0, 5, and 10 mg octacosanol (extracted from rice bran, purity >92%)/kg feed. The feeding trial lasted for 10 weeks. The results showed that the dietary addition of 5 and 10 mg/kg octacosanol improved feed efficiency by 4.9% and 3.4% (P < 0.01), increased the albumen height by 20.5% and 13.3% (P < 0.01), the Haugh unit score by 12.9% and 8.7% (P < 0.01), and the eggshell strength by 39.5% and 24.5% (P < 0.01), respectively, compared with the control diet. Dietary octacosanol addition significantly affected serum triiodothyronine, estradiol, follicle-stimulating hormone levels (P < 0.05), and progesterone and luteinizing hormone level (P < 0.01). Compared with the control, dietary addition of octacosanol at 5 mg/kg promoted the follicle-stimulating hormone receptor (FSHR) mRNA expression in different-sized follicles, and significantly increased the FSHR mRNA expression of granulosa cells from the F2 and F3 follicles (P < 0.05). Dietary supplementation with both 5 and 10 mg/kg octacosanol promoted the mRNA expression of luteinizing hormone receptor and prolactin receptor in different-sized follicles, and significantly up-regulated the expression levels in F1 granulosa cells (P < 0.05). The ovarian weight was significantly increased with the dietary addition of 5 mg/kg octacosanol (P < 0.05). The numbers of small yellow follicles and large white follicles were increased with the addition of dietary 5 and 10 mg/kg octacosanol (P < 0.01). This study provides evidence that octacosanol has the capacity to improve reproductive performance, indicating that it is a potentially effective feed additive in egg production.

Changes in elevated cholesterol in the era of tenofovir in South Africa: risk factors, clinical management and outcomes

OBJECTIVES

Antiretroviral therapy (ART) has been associated with unfavourable lipid profile changes and increased risk of cardiovascular disease (CVD). With a growing population on ART in South Africa, there has been concern about the increase in noncommunicable diseases such as CVD. We determined risk factors associated with increased total cholesterol (TC) in a large cohort on ART and describe the clinical management thereof.

METHODS

We conducted an observational cohort study of ART-naïve adults initiating standard first-line ART in a large urban clinic in Johannesburg, South Africa. TC was measured annually for most patients. A proportional hazards regression model was used to determine risk factors associated with incident high TC (≥ 6 mmol/L).

RESULTS

Significant risk factors included initial regimen non-tenofovir vs. tenofovir [hazard ratio (HR) 1.54; 95% confidence interval (CI) 1.14-2.08], age ≥40 vs. <30 years (HR 3.22; 95% CI 2.07-4.99), body mass index (BMI) ≥ 30 kg/m² (HR 1.65; 95% CI 1.18-2.31) and BMI 25-29.9 kg/m² (HR 1.70; 95% CI 1.30-2.23) vs. 18-24.9 kg/m² , and baseline CD4 count < 50 cells/μL (HR 1.55; 95% CI 1.10-2.20) and 50-99 cells/μL (HR 1.40; 95% CI 1.00-1.97) vs. > 200 cells/μL. Two-thirds of patients with high TC were given cholesterol-lowering drugs, after repeat TC measurements about 12 months apart, while 31.8% were likely to have received dietary counselling only.

CONCLUSIONS

Older age, higher BMI, lower CD4 count and a non-tenofovir regimen were risk factors for incident elevated TC. Current guidelines do not indicate regular cholesterol testing at ART clinic visits, which are the main exposure to regular clinical monitoring for most HIV-positive individuals. If regular cholesterol monitoring is conducted, improvements can be made to identify and treat patients sooner.

Brief interventions to prevent sexually transmitted infections suitable for in-service use: A systematic review

BACKGROUND

Sexually transmitted infections (STIs) are more common in young people and men who have sex with men (MSM) and effective in-service interventions are needed.

METHODS

A systematic review of randomized controlled trials (RCTs) of waiting-room-delivered, self-delivered and brief healthcare-provider-delivered interventions designed to reduce STIs, increase use of home-based STI testing, or reduce STI-risk behavior was conducted. Six databases were searched between January 2000 and October 2014.

RESULTS

17,916 articles were screened. 23 RCTs of interventions for young people met our inclusion criteria. Significant STI reductions were found in four RCTs of interventions using brief one-to-one counselling (2 RCTs), video (1 RCT) and a STI home-testing kit (1 RCT). Increase in STI test uptake was found in five studies using video (1 RCT), one-to-one counselling (1 RCT), home test kit (2 RCTs) and a web-based intervention (1 RCT). Reduction in STI-risk behavior was found in seven RCTs of interventions using digital online (web-based) and offline (computer software) (3 RCTs), printed materials (1 RCT) and video (3 RCTs). Ten RCTs of interventions for MSM met our inclusion criteria. Three tested for STI reductions but none found significant differences between intervention and control groups. Increased STI test uptake was found in two studies using brief one-to-one counselling (1 RCT) and an online web-based intervention (1 RCT). Reduction in STI-risk behavior was found in six studies using digital online (web-based) interventions (4 RCTs) and brief one-to-one counselling (2 RCTs).

CONCLUSION

A small number of interventions which could be used, or adapted for use, in sexual health clinics were found to be effective in reducing STIs among young people and in promoting self-reported STI-risk behavior change in MSM.