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Introduction

A decreased frequency of unprotected sex during episodes of concurrent relationships may dramatically reduce the role of concurrency in accelerating the spread of HIV. Such a decrease could be the result of coital dilution – the reduction in per-partner coital frequency from additional partners – and/or increased condom use during concurrency. To study the effect of concurrency on the frequency of unprotected sex, we examined sexual behaviour data from three communities with high HIV prevalence around Cape Town, South Africa.

Methods

We conducted a cross-sectional survey from June 2011 to February 2012 using audio computer-assisted self-interviewing to reconstruct one-year sexual histories, with a focus on coital frequency and condom use. Participants were randomly sampled from a previous TB and HIV prevalence survey. Mixed effects logistic and Poisson regression models were fitted to data from 527 sexually active adults reporting on 1210 relationship episodes to evaluate the effect of concurrency status on consistent condom use and coital frequency.

Results

The median of the per-partner weekly average coital frequency was 2 (IQR: 1–3), and consistent condom use was reported for 36% of the relationship episodes. Neither per-partner coital frequency nor consistent condom use changed significantly during episodes of concurrency (aIRR=1.05; 95% confidence interval (CI): 0.99–1.24 and aOR=1.01; 95% CI: 0.38–2.68, respectively). Being male, coloured, having a tertiary education, and having a relationship between 2 weeks and 9 months were associated with higher coital frequencies. Being coloured, and having a relationship lasting for more than 9 months, was associated with inconsistent condom use.

Conclusions

We found no evidence for coital dilution or for increased condom use during concurrent relationship episodes in three communities around Cape Town with high HIV prevalence. Given the low levels of self-reported consistent condom use, our findings suggest that if the frequency of unprotected sex with each of the sexual partners is sustained during concurrent relationships, HIV-positive individuals with concurrent partners may disproportionately contribute to onward HIV transmission.  相似文献   
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High Na+ intake has been proposed to induce a rise in the activity of a circulating inhibitor of the Na+, K+-pump. The effects on male Wistar rats of a high sodium diet (8 per cent NaCl) on the activity of such a plasma Na+, K+-ATPase inhibitor were investigated. Systolic blood pressure, body weight, urinary Na+ excretion, haematocrit, intraerythrocytic Na+ content and the activity of a Na+ dependent transport system, i.e. the uptake of 5-HT by blood platelets were measured in parallel. After one week, neither systolic blood pressure nor intraerythrocytic Na+ content were modified, but the ability of the plasma extracts to inhibit renal Na+, K+-ATPase increased (70.9 +/- 1.7 vs 76.3 +/- 2.1 mumol Pi/mg/h; p = 0.05). After two weeks, the plasma inhibitory activity, the systolic blood pressure and the intraerythrocytic Na+ content were higher than that of control animals (65.5 +/- 1.6 vs 79.1 +/- 2.8 mumol Pi/mg/h, p less than 0.001; 132 +/- 2 vs 114 +/- 4 mmHg, p. +/- 0.001 and 4.95 +/- 0.32 vs 3.81 +/- 0.36 mmol/l.cells, p less than 0.05). After three months, the ability of plasma extracts to inhibit the Na+ pump and the systolic blood pressure were still elevated (57.8 +/- 1.8 vs 72.9 +/- 1.8 mumol Pi/mg/h, p less than 0.001; 145 +/- 4 vs 118 +/- 2 mmHg, p less than 0.001) whereas intraerythrocytic Na+ content had returned to control levels and 5-HT uptake was not modified.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
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BackgroundWith the rapid growth in online education programs in nursing, quality of education through this modality is becoming of greater importance.PurposeThis paper aims to explore current recommendations and standards for quality in online nursing education offered by nursing regulatory, accrediting, and licensing organizations.MethodIndividual interviews were conducted with the leaders from four accrediting, licensing and certifying organizations in nursing about their perspectives on quality standards for online education.FindingsThe following themes emerged from the qualitative interviews: Theme 1- Standards are not specific to online education; Theme 2-This is not up to us - Professional organizations can offer recommendations but not responsible for regulations; and Theme 3- Each institution has responsibility to provide support and evaluate the quality of online education.DiscussionSchools of nursing should continue to incorporate current standards for quality in online education as the methods of delivery continue to evolve in this highly technologically-oriented world.  相似文献   
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Southern Africa, home to about 20 % of the global burden of infection continues to experience high rates of new HIV infection despite substantial programmatic scale-up of treatment and prevention interventions. While several countries in the region have had substantial reductions in HIV infection, almost half a million new infections occurred in this region in 2012. Sexual transmission remains the dominant mode of transmission. A recent national household survey in Swaziland revealed an HIV prevalence of 14.3 % among 18–19 year old girls, compared to 0.8 % among their male peers. Expanded ART programmes in Southern Africa have resulted in dramatically decreased HIV incidence and HIV mortality rates. In South Africa alone, it is estimated that more than 2.1 million of the 6.1 million HIV-positive people were receiving ART by the end of 2012, and that this resulted in more than 2.7 million life-years saved, and hundreds of thousands of HIV infections averted. Biological, behavioural and structural factors all contribute to the ongoing high rates of new HIV infection; however, as the epidemic matures and mortality is reduced from increased ART coverage, epidemiological trends become hard to quantify. What is clear is that a key driver of the Southern African epidemic is the high incidence rate of infection in young women, a vulnerable population with limited prevention options. Moreover, whilst ongoing trials of combination prevention, microbicides and behavioural economics hold promise for further epidemic control, an AIDS-free generation will not be realised unless incident infections in key populations are reduced.  相似文献   
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Background

Androgen deprivation therapy (ADT) plus docetaxel is the standard of care in fit men with metastatic castration-naive prostate cancer (mCNPC) following results from GETUG-AFU 15, CHAARTED, and STAMPEDE. No data are available on the efficacy of treatments used for metastatic castration-resistant prostate cancer (mCRPC) in men treated upfront with ADT plus docetaxel for mCNPC.

Objective

To investigate the efficacy and tolerance of subsequent treatments in patients treated upfront with chemo-hormonal therapy for mCNPC.

Design, setting, and participants

Retrospective data from the GETUG-AFU 15 phase 3 trial were collected for treatments received for mCRPC.

Outcome measurements and statistical analysis

For the first three lines of salvage treatment for mCRPC we investigated the biochemical progression-free survival, maximum prostate-specific antigen (PSA) decline, overall survival, and tolerance.

Results and limitations

Overall, 245 patients received at least one treatment for mCRPC. For docetaxel used in first-line, a PSA decline ≥50% was observed in 25/66 (38%) and in 4/20 patients (20%) who had received upfront ADT alone and ADT plus docetaxel (p = 0.14). The median biochemical progression-free survival was 6.0 mo (95% confidence interval: 3.6–7.7) and 4.1 mo (95% confidence interval: 1.3–4.9), respectively. For docetaxel used in first- or second-line, a PSA decline ≥50% was observed in 36/80 (45%) and in 4/29 patients (14%) who had received upfront ADT alone and ADT plus docetaxel (p = 0.07). PSA declines ≥50% were observed with bicalutamide in 12/28 (43%) and 4/23 patients (17%) who had received upfront ADT alone and ADT plus docetaxel. Among men treated upfront with ADT plus docetaxel who received abiraterone or enzalutamide for mCRPC, 10/19 patients (53%) achieved a PSA decline ≥50%. Few grade 3–4 events occurred. Study limitations include the observational design and retrospective characteristics of this analysis, without standardized therapeutic salvage protocols, and the limited number of patients in some of the treatment subgroups.

Conclusions

Docetaxel rechallenge following progression to mCRPC after upfront ADT plus docetaxel for mCNPC was active only in a limited number of patients. Available data on abiraterone and enzalutamide support maintained efficacy in this setting. The lack of standardized therapeutic protocols for men developing mCRPC limits the comparability between patients.

Patient summary

Rechallenging docetaxel at castration-resistance was active only in a limited number of patients treated upfront with chemo-hormonal therapy for metastatic castration-naive prostate cancer. Anticancer activity was suggested with abiraterone or enzalutamide in this setting.  相似文献   
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Introduction

Concurrent partnerships (CPs) have been suggested as a risk factor for transmitting HIV, but their impact on the epidemic depends upon how prevalent they are in populations, the average number of CPs an individual has and the length of time they overlap. However, estimates of prevalence of CPs in Southern Africa vary widely, and the duration of overlap in these relationships is poorly documented. We aim to characterize concurrency in a more accurate and complete manner, using data from three disadvantaged communities of Cape Town, South Africa.

Methods

We conducted a sexual behaviour survey (n=878) from June 2011 to February 2012 in Cape Town, using Audio Computer-Assisted Self-Interviewing to collect sexual relationship histories on partners in the past year. Using the beginning and end dates for the partnerships, we calculated the point prevalence, the cumulative prevalence and the incidence rate of CPs, as well as the duration of overlap for relationships begun in the previous year. Linear and binomial regression models were used to quantify race (black vs. coloured) and sex differences in the duration of overlap and relative risk of having CPs in the past year.

Results

The overall point prevalence of CPs six months before the survey was 8.4%: 13.4% for black men, 1.9% for coloured men, 7.8% black women and 5.6% for coloured women. The median duration of overlap in CPs was 7.5 weeks. Women had less risk of CPs in the previous year than men (RR 0.43; 95% CI: 0.32–0.57) and black participants were more at risk than coloured participants (RR 1.86; 95% CI: 1.17–2.97).

Conclusions

Our results indicate that in this population the prevalence of CPs is relatively high and is characterized by overlaps of long duration, implying there may be opportunities for HIV to be transmitted to concurrent partners.  相似文献   
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