Directional screening and identification of potential cytotoxic components from Achnatherum inebrians by a combination of surface palsmon resonance and chromatography

Objective: To establish a method for directional screening of the cytotoxic components from the medicinal herb of Achnatherum inebrians by a combination of surface plasmon resonance (SPR) biosensor and chromatographic isolation technology. Methods: Under the guidance of bioactive assessment based on binding abilities between objects and the α-Mannosidase (α-Man) target, the active components from different solvents extracts, different polar extraction parts and fractions were screened orderly and directionally using SPR. Components with a high binding ability to α-Man can be precisely oriented in a narrower fractions range and are easy to isolate. Three human cancer cells were used to evaluate the cytotoxic activity of component with the highest affinity to α-Man. Results: Eight compounds were isolated and identificated from A. inebrians for the first time. Deoxyvasicinone possessed the highest affinity to α-Man among them. Moreover, deoxyvasicinone showed good effects on inhibited proliferation of human hepatoma cells HepG2 (IC50 = 5.7 μmol/L), human breast cancer cells MCF7 (IC50 = 7.21 μmol/L) and human lung cancer cells HCC827 (IC50 = 0.75 μmol/L), respectively. In particular, its inhibitory effect on HCC827 was stronger than the positive drug gefitinib (IC50 = 1.65 μmol/L). Conclusion: A comprehensive strategy of directional screening potential cytotoxic components from herb based on biomolecular interaction and chromatography was established. Deoxyvasicinone as an effective anti-cancer component was initially isolated from A. inebrians. It is expected that this screening strategy could provide new perspectives for rapid screening and identification of active components from natural plants with the complex matrix.     

The Relationship Between Social Support,HIV Serostatus,and Perceived Likelihood of Being HIV Positive Among Self-Settled Female,Foreign Migrants in Cape Town,South Africa

Female cross-border migrants experience elevated risks for HIV, and migrants in South Africa may face additional risks due to the country’s underlying HIV prevalence. These risks may be mitigated by the receipt of social support. A behavioral risk-factor survey was administered using respondent-driven sampling. Multivariable regression models assessed the relationships between social support and two HIV outcomes: HIV serostatus and perceived HIV status. Low social support was not significantly associated with HIV status (aOR?=?1.03, 95?% CI 0.43–2.46), but was significantly related to a perception of being HIV positive (aPR?=?1.36, 95?% CI 1.04–1.78). Age, marital status, and education level were significantly associated with HIV serostatus. Illegal border-crossing, length of time in South Africa, anal sex, and transactional sex were significantly associated with aperception of being HIV positive. Future research should investigate how HIV risks and the receipt of social support change throughout the migration process.     

Effectiveness of Respondent-Driven Sampling to Recruit High Risk Heterosexual Men Who Have Multiple Female Sexual Partners: Differences in HIV Prevalence and Sexual Risk Behaviours Measured at Two Time Points

Regular HIV bio-behavioural surveillance surveys (BBSS) among high risk heterosexual (HRH) men who have multiple female sexual partners is needed to monitor HIV prevalence and risk behaviour trends, and to improve the provision and assessment of HIV prevention strategies for this population. In 2006 and 2008 we used respondent-driven sampling to recruit HRH men and examine differences in HIV prevalence and risk behaviours between the two time points. In both surveys, the target population had little difficulty in recruiting others from their social networks that were able to sustain the chain-referral process. Key variables reached equilibrium within one to six recruitment waves and homophily indices showed neither tendencies to in-group nor out-group preferences. Between 2006 and 2008 there were significant differences in condom use with main sexual partners; numbers of sexual partners; and alcohol consumption. Further BBSS among this population are needed before more reliable trends can be inferred.     

Why do families still not receive the child support grant in South Africa? A longitudinal analysis of a cohort of families across South Africa

Background

Child cash transfers are increasingly recognised for their potential to reduce poverty and improve health outcomes. South Africa‘s child support grant (CSG) constitutes the largest cash transfer in the continent. No studies have been conducted to look at factors associated with successful receipt of the CSG. This paper reports findings on factors associated with CSG receipt in three settings in South Africa (Paarl in the Western Cape Province, and Umlazi and Rietvlei in KwaZulu-Natal).

Methods

This study used longitudinal data from a community-based cluster-randomized trial (PROMISE EBF) promoting exclusive breastfeeding by peer-counsellors in South Africa (ClinicalTrials.gov: NCT00397150). 1148 mother-infant pairs were enrolled in the study and data on the CSG were collected at infant age 6, 12, 24 weeks and 18–24 months. A stratified cox proportional hazards regression model was fitted to the data to investigate factors associated with CSG receipt.

Results

Uptake of the CSG amongst eligible children at a median age of 22 months was 62% in Paarl, 64% in Rietvlei and 60% in Umlazi. Possessing a birth certificate was found to be the strongest predictor of CSG receipt (HR 3.1, 95% CI: 2.4 -4.1). Other factors also found to be independently associated with CSG receipt were an HIV-positive mother (HR 1.2, 95% CI: 1.0-1.4) and a household income below R1100 (HR1.7, 95% CI: 1.1 -2.6).

Conclusion

Receipt of the CSG was sub optimal amongst eligible children showing administrative requirements such as possessing a birth certificate to be a serious barrier to access. In the spirit of promoting and protecting children’s rights, more efforts are needed to improve and ease access to this cash transfer program.

     

Early cessation of breastfeeding amongst women in South Africa: an area needing urgent attention to improve child health

ABSTRACT: BACKGROUND: Breastfeeding is a critical component of interventions to reduce child mortality. Exclusive breastfeeding practice is extremely low in South Africa and there has been no improvement in this over the past ten years largely due to fears of HIV transmission. Early cessation of breastfeeding has been found to have negative effects on child morbidity and survival in several studies in Africa. This paper reports on determinants of early breastfeeding cessation among women in South Africa. METHODS: This is a sub group analysis of a community-based cluster-randomized trial (PROMISE EBF) promoting exclusive breastfeeding in three South African sites (Paarl in the Western Cape Province, and Umlazi and Rietvlei in KwaZulu-Natal) between 2006 and 2008 (ClinicalTrials.gov no: NCT00397150). Infant feeding recall of 22 food and fluid items was collected at 3, 6, 12 and 24?weeks postpartum. Women's experiences of breast health problems were also collected at the same time points. 999 women who ever breastfed were included in the analysis. Univariable and multivariable logistic regression analysis adjusting for site, arm and cluster, was performed to determine predictors of stopping breastfeeding by 12?weeks postpartum. RESULTS: By 12?weeks postpartum, 20% of HIV-negative women and 40% of HIV-positive women had stopped all breastfeeding. About a third of women introduced other fluids, most commonly formula milk, within the first 3?days after birth. Antenatal intention not to breastfeed and being undecided about how to feed were most strongly associated with stopping breastfeeding by 12?weeks (Adjusted odds ratio, AOR 5.6, 95% CI 3.4 - 9.5 and AOR 4.1, 95% CI 1.6 - 10.8, respectively). Also important was self-reported breast health problems associated with a 3-fold risk of stopping breastfeeding (AOR 3.1, 95%CI 1.7 - 5.7) and the mother having her own income doubled the risk of stopping breastfeeding (AOR 1.9, 95% CI 1.3 - 2.8). CONCLUSION: Early cessation of breastfeeding is common amongst both HIV-negative and positive women in South Africa. There is an urgent need to improve antenatal breastfeeding counselling taking into account the challenges faced by working women as well as early postnatal lactation support to prevent breast health problems.     

X-ray irradiation selectively kills thymocytes of different stages and impairs the maturation of donor-derived CD4~+CD8~+ thymocytes in recipient thymus

The aim of the present study was to determine whether the sensitivity of thymocytes to X-ray radiation depends on their proliferative states and whether radiation impairs the maturation of donor-derived thymocytes in recipient thymus.We assigned 8-week-old C57BL/6J mice into three treatment groups:1) untreated;2) X-ray radiation;3) X-ray radiation plus bone marrow transplantation with donor bone marrow cells from transgenic mice express-ing enhanced green fluorescent protein(GFP) on a universal promoter.After 4 weeks,the size of the thymus,the number and proliferation of thymocytes and ratios of different stage thymocytes were analyzed by immunohisto-chemistry and flow cytometry.The results showed that:1) CD4+CD8+ thymocytes were more sensitive to X-ray radiation-induced cell death than other thymocytes;2) the proliferative capacity of CD4+CD8+ thymocytes was higher than that of other thymocytes;3) the size of the thymus,the number of thymocytes and ratios of thymo-cytes of different stages in irradiated mice recovered to the normal level of untreated mice by bone marrow trans-plantation;4) the ratio of GFP-positive CD4+CD8+ thymocytes increased significantly,whereas the ratio of GFP-positive CD4+ or CD8+ thymocytes decreased significantly.These results indicate that the degree of sensitivity of thymocytes to X-ray radiation depends on their proliferative states and radiation impairs the maturation of donor-derived CD4+CD8+ thymocytes in recipient thymus.     

赤芍通过抗神经胶质增生及抗氧化保护局部短暂性脑缺血小鼠海马部位神经的研究

目的：卒中是全球第二大死亡原因。本研究探究赤芍（Paeoniae Radix Rubra， PRR）对缺血性脑卒中小鼠的神经保护作用。方法：使用小鼠大脑中动脉堵塞法构建局部脑缺血模型。将实验动物分为4组，假手术组（Sham 组）、假手术给药组（PRR-sham组）、手术组（Isch组）、手术给药组（PRR-Isch组）。采用TTC染色法测量各组小鼠脑梗死体积；免疫组织化学染色观察各组之间小鼠缺血侧大脑海马区神经元细胞的凋亡情况以及星形胶质细胞和小胶质细胞的活化程度；采用蛋白印迹法观察小鼠缺血侧海马超氧化物歧化酶1（SOD1）、超氧化物歧化酶2（SOD2）、过氧化氢酶抗体（Catalase）表达水平。结果：赤芍可以明显减少局部脑缺血小鼠的脑梗死体积，并能抑制海马CA1区星形胶质细胞和小胶质细胞的活化程度，同时可以改善由缺血再灌注损伤引起的SOD1、SOD2和Catalase的表达水平下降情况。结论：赤芍可以通过抗胶质增生以及抗氧化作用改善局部短暂性脑缺血小鼠的神经损伤情况。