Sexual Networks and HIV Risk among Black Men Who Have Sex with Men in 6 U.S. Cities

BACKGROUND

Sexual networks may place U.S. Black men who have sex with men (MSM) at increased HIV risk.

METHODS

Self-reported egocentric sexual network data from the prior six months were collected from 1,349 community-recruited Black MSM in HPTN 061, a multi-component HIV prevention intervention feasibility study. Sexual network composition, size, and density (extent to which members are having sex with one another) were compared by self-reported HIV serostatus and age of the men. GEE models assessed network and other factors associated with having a Black sex partner, having a partner with at least two age category difference (age difference between participant and partner of at least two age group categories), and having serodiscordant/serostatus unknown unprotected anal/vaginal intercourse (SDUI) in the last six months.

RESULTS

Over half had exclusively Black partners in the last six months, 46% had a partner of at least two age category difference, 87% had ≤5 partners. Nearly 90% had sex partners who were also part of their social networks. Among HIV-negative men, not having anonymous/exchange/ trade partners and lower density were associated with having a Black partner; larger sexual network size and having non-primary partners were associated with having a partner with at least two age category difference; and having anonymous/exchange/ trade partners was associated with SDUI. Among HIV-positive men, not having non-primary partners was associated with having a Black partner; no sexual network characteristics were associated with having a partner with at least two age category difference and SDUI.

CONCLUSIONS

Black MSM sexual networks were relatively small and often overlapped with the social networks. Sexual risk was associated with having non-primary partners and larger network size. Network interventions that engage the social networks of Black MSM, such as interventions utilizing peer influence, should be developed to address stable partnerships, number of partners, and serostatus disclosure.

Hoop stress and the conical connection

Dental implant-abutment connection design has developed into the use of a conical, shank and socket connection between the implant abutment and fixture. The connection between these two elements is, in effect, a conical wedge that may exert lateral forces under load that may result in fracture of the coronal implant socket fixture walls. This study evaluated the axial loading on a conical connection and found that axial loads were well tolerated but off-axial loads were not. Fracture of the implant coronal socket fixture wall occurred under off-axial loading.

β-Arrestin-2 knockout prevents development of cellular μ-opioid receptor tolerance but does not affect opioid-withdrawal-related adaptations in single PAG neurons

BACKGROUND AND PURPOSE

Tolerance to the behavioural effects of morphine is blunted in β-arrestin-2 knockout mice, but opioid withdrawal is largely unaffected. The cellular mechanisms of tolerance have been studied in some neurons from β-arrestin-2 knockouts, but tolerance and withdrawal mechanisms have not been examined at the cellular level in periaqueductal grey (PAG) neurons, which are crucial for central tolerance and withdrawal phenomena.

EXPERIMENTAL APPROACH

μ-Opioid receptor (MOPr) inhibition of voltage-gated calcium channel currents (ICa ) was examined by patch-clamp recordings from acutely dissociated PAG neurons from wild-type and β-arrestin-2 knockout mice treated chronically with morphine (CMT) or vehicle. Opioid withdrawal-induced activation of GABA transporter type 1 (GAT-1) currents was determined using perforated patch recordings from PAG neurons in brain slices.

KEY RESULTS

MOPr inhibition of ICa in PAG neurons was unaffected by β-arrestin-2 deletion. CMT impaired coupling of MOPrs to ICa in PAG neurons from wild-type mice, but this cellular tolerance was not observed in neurons from CMT β-arrestin-2 knockouts. However, β-arrestin-2 knockouts displayed similar opioid-withdrawal-induced activation of GAT-1 currents as wild-type PAG neurons.

CONCLUSIONS AND IMPLICATIONS

In β-arrestin-2 knockout mice, the central neurons involved in the anti-nociceptive actions of opioids also fail to develop cellular tolerance to opioids following chronic morphine. The results also provide the first cellular physiological evidence that opioid withdrawal is not disrupted by β-arrestin-2 deletion. However, the unaffected basal sensitivity to opioids in PAG neurons provides further evidence that changes in basal MOPr sensitivity cannot account for the enhanced acute nociceptive response to morphine reported in β-arrestin-2 knockouts.

LINKED ARTICLES

This article is part of a themed section on Opioids: New Pathways to Functional Selectivity. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-2.

Trigeminal ganglion neuron subtype-specific alterations of Ca(V)2.1 calcium current and excitability in a Cacna1a mouse model of migraine

Familial hemiplegic migraine type-1 (FHM1), a monogenic subtype of migraine with aura, is caused by gain-of-function mutations in Ca(V)2.1 (P/Q-type) calcium channels. The consequences of FHM1 mutations on the trigeminovascular pathway that generates migraine headache remain largely unexplored. Here we studied the calcium currents and excitability properties of two subpopulations of small-diameter trigeminal ganglion (TG) neurons from adult wild-type (WT) and R192Q FHM1 knockin (KI) mice: capsaicin-sensitive neurons without T-type calcium currents (CS) and capsaicin-insensitive neurons characterized by the expression of T-type calcium currents (CI-T). Small TG neurons retrogradely labelled from the dura are mostly CS neurons, while CI-T neurons were not present in the labelled population. CS and CI-T neurons express Ca(V)2.1 channels with different activation properties, and the Ca(V)2.1 channels are differently affected by the FHM1 mutation in the two TG neuron subtypes. In CI-T neurons from FHM1 KI mice there was a larger P/Q-type current density following mild depolarizations, a larger action potential (AP)-evoked calcium current and a longer AP duration when compared to CI-T neurons from WT mice. In striking contrast, the P/Q-type current density, voltage dependence and kinetics were not altered by the FHM1 mutation in CS neurons. The excitability properties of mutant CS neurons were also unaltered. Congruently, the FHM1 mutation did not alter depolarization-evoked CGRP release from the dura mater, while CGRP release from the trigeminal ganglion was larger in KI compared to WT mice. Our findings suggest that the facilitation of peripheral mechanisms of CGRP action, such as dural vasodilatation and nociceptor sensitization at the meninges, does not contribute to the generation of headache in FHM1.

Subcutaneous anthrax in three intravenous drug users: a new clinical diagnosis

Anthrax is extremely rare in the western world but is endemic to areas of south and central Asia. In early 2010 an outbreak was identified in heroin-injecting intravenous drug users in the United Kingdom and Europe. Afghanistan is currently the principal source of heroin which reaches the United Kingdom. When anthrax occurs, cutaneous disease accounts for over 95% of cases. At least 47 cases with 13 deaths have been confirmed so far. We present three cases presenting during this time with marked swelling, one resulting in compartment syndrome but all with an absence of the expected cutaneous appearances. We suggest that rather than cutaneous anthrax, these patients represent a new subcutaneous presentation of anthrax.

Lessons from eleven primary health care nursing innovations in New Zealand

INTRODUCTION

In New Zealand in 2003, 11 primary health care (PHC) nursing innovation projects and an evaluation of the initiative were funded by the Ministry of Health to develop and explore the ways new models of nursing practice could help address health inequalities and contribute to PHC.

DESIGN AND METHODS

A research-and-development approach was used in the evaluation. Data were gathered from interviews with national stakeholders, workshops with personnel from all projects, visits to each project site and case studies of four projects. Analysis involved assessing each project individually as well as the projects as a whole.

CONTEXT

The initiative was one of many international and local PHC developments in this period designed to reduce health inequalities and improve patient care and health outcomes.

FINDINGS

Each project was developed from a different starting point; was located in different parts of the health system; and had different levels of funding. Some were principally focused on leading nursing development; others focused on developing nursing practice. Each involved influencing or providing nursing services, nurse education, leadership and service integration. Most projects progressed well, but some had limited success.

LESSONS

Lessons are on many levels, and include those related to: developing successful innovation; the importance of nursing leadership; developing the nursing workforce; and advancing nursing practice.

CONCLUSION

The funding of the innovative projects enabled nurses to pioneer developments. Such funding is important, as it paves the way for change and provides an opportunity for reflection and new learnings.

Compliance in the measurement of CURB-65 in patients with community acquired pneumonia and potential implications for early discharge

The CURB-65 community-acquired pneumonia (CAP) severity score is a convenient 5-variable disease-specific tool validated to predict mortality and the decision to admit. This prospective study seeks to determine (a) the accuracy CAP diagnosis; (b) the degree to which the CURB-65 score was being documented; and (c) the degree to which CURB-65 was being utilised as an admission and early discharge tool in the A&E Department in the evaluation of patients presenting with CAP. Of 45 patients referred with an admitting diagnosis of CAP, 28 were subsequently found to satisfy the criteria of CAP, an over diagnosis of 38%. Documentation of CURB-65 was 7%; recording of core variables was 81% i.e. 4 out of 5 variables and confusion was the variable least likely to be documented. On re-scoring, 50% of patients had a score of 0 or 1 and a further 28% had a score of 2. We conclude that CAP is significantly overdiagnosed; that the CURB-65 severity score is not being utilised and that between 50 and 78% of patients with CAP may be admitted unnecessarily. This study raises important issues in the current management of CAP in the Irish Healthcare system.

Towards a receptor for nocistatin?

Nocistatin is a peptide derived from the pronociceptin precursor, the source of nociceptin, the endogenous ligand for the nociceptin (NOP or ORL1). Despite nocistatin showing activity in a wide range of assays for nociception and other CNS activities, there is a dearth of information regarding the cellular actions of this peptide in the brain, and no receptor for nocistatin has been identified. In a study published in this issue of the British Journal of Pharmacology, Fantin and colleagues demonstrate that nocistatin inhibits 5-HT release from cortical synaptosomes in a concentration-dependent and Pertussis toxin-sensitive manner. The actions of nocistatin are independent of activity at NOP receptors. This study represents the first unambiguous demonstration of nocistatin agonist actions in brain and, taken together with previous work in the spinal cord, provides strong evidence that there is an as yet unidentified G protein-coupled receptor for nocistatin.

The South African stroke risk in general practice study

BACKGROUND

Incidence of stroke is increasing in sub-Saharan Africa and stroke prevention is an essential component of successful stroke management. General practitioners (GPs) are well placed to manage stroke risk factors. To design appropriate strategies for risk factor reduction we need to know the risk factor prevalence in each of the population groups attending GPs. The aim of this study was to establish the prevalence of stroke risk factors in the South African general practice population.

METHOD

We conducted a multicentre, observational study of patients attending general practice in South Africa. Two hundred general practices were randomly selected from lists provided by pharmaceutical representatives. Each GP approached 50 consecutive patients aged 30 years and older. Patients completed an information sheet and the GP documented the patient's risk factors. The resulting sample is relevant if not necessarily representative in a statistical sense.

RESULTS

A total of 9 731 questionnaires were returned out of a possible 10,000. The mean age of particpants was 50.7 years. Seventy-six per cent had 1 or more risk factors and 40% had 2 or more risk factors. Hypertension was the commonest risk factor in all population groups (55%) but was highest in black patients (59%). Dyslipidaemia was commonest in whites (37%) and least common in blacks (5%). Diabetes was commonest in Asians (24%) but least common in whites (8%). Risk factors other than smoking increased with age.

CONCLUSION

This study provides unique data on the prevalence of stroke risk factors in a South African general practice population. Risk factors are common in all population groups, but differ in distribution among the groups. There is considerable opportunity to reduce the burden of stroke in South Africa through GP screening for and treatment of risk factors.

Restorative impact of rabeprazole on gastric mucus and mucin production impairment during naproxen administration: its potential clinical significance

Rabeprazole augments gastric mucus and mucin production in humans. However, its potential restorative impact on gastric mucus and mucin production impairment, resulting from administration of naproxen, remained to be explored. Therefore, we measured the content of mucus and mucin in gastric juice (GJ) before and after administration of naproxen with rabeprazole or placebo. The study was approved by HSC at KUMC and conducted in 21 asymptomatic, H. pylori-negative volunteers in a double-blind, placebo-controlled, crossover design. The content of gastric mucus in GJ, after exhaustive dialysis and complete lyophilization, was assessed gravimetrically, whereas the content of mucin was measured after its purification with equilibrium density-gradient ultracentrifugation in CsC1. Gastric mucus secretion during administration of naproxen with placebo declined significantly both in basal (by 44%; P < 0.001) and in pentagastrin-stimulated (by 35%; P < 0.001) conditions. Coadministration of rabeprazole significantly restored the naproxen-induced impairment in mucus production in basal conditions (by 47%; P < 0.01) and by 22% during stimulation with pentagastrin. Gastric mucin secretion during naproxen/placebo administration also declined significantly in both basal (by 39%; P < 0.01) and stimulated (by 49%; P = 0.003) conditions. Rabeprazole also significantly restored the naproxen-induced decline of gastric mucin output during pentagastrin-stimulated conditions (by 67%; P = 0.003) and by 40% in basal conditions (P = 0.05). The restorative capacity of rabeprazole on the quantitative impairment of gastric mucus and mucin during administration of naproxen may translate into a clinical benefit of protection of the upper alimentary tract from NSAID-related mucosal injury.

Vitrectomy and gas for inferior break retinal detachments: are the results comparable to vitrectomy, gas, and scleral buckle?

AIMS

To compare the success rates of vitrectomy and gas with vitrectomy, gas, and buckle in the treatment of inferior break retinal detachments.

METHODS

A retrospective case note review of 86 patients who presented with inferior break retinal detachments was carried out. An inferior break was defined as a horseshoe tear present between 4 and 8 o'clock. Patients were analysed in two groups; group A consisted of 41 patients who underwent a vitrectomy and gas, group B consisted of 45 patients who underwent a vitrectomy, gas, and scleral buckle. The features of the retinal detachment, peroperative and postoperative complications, and outcomes of treatment were recorded for each patient.

RESULTS

The primary anatomical success rate at 3 months was 89% in group A versus 73% in group B (p = 0.11). There was no statistical difference in the complication rate between the two groups (p = 0.819). The most common cause of treatment failure was proliferative vitreoretinopathy, 20% (n = 9) in group B compared with 5% (n = 2) in group A and this reached statistical significance (p = 0.0159). There was a higher rate of epiretinal membrane development in group B (p = 0.0004). The final attachment rate was not statistically different between the two groups, 95% (39) in group A and 93% (42) in group B (p = 1.0).

CONCLUSION

Vitrectomy and gas without the application of a scleral buckle may be used to safely treat inferior break retinal detachments. It may be used as an alternative to vitrectomy, gas, and buckle which has an increased risk of choroidal haemorrhage, requires a longer operating time, and has all the associated complications of a scleral buckle.

The life course prospective design: an example of benefits and problems associated with study longevity

Although the life course prospective study design has many benefits, and information from such studies is in increasing demand for scientific and policy purposes, it has potential inherent design problems associated with its longevity. These are in particular the fixed sample structure and the data collected in early life, which are each determined by the scientific principles of another time and the risk over time of increased sample loss and distortion through loss. The example of a national birth cohort in Britain, studied from birth so far to age 53 years is used to address these questions. Although the response rate is high, avoidable loss, which was low in childhood, increased in adulthood, and was highest in those in adverse socio-economic circumstances and those with low scores on childhood cognitive measures. Recent permanent refusal rate rises may be the result of better tracing and/or a response to increased requests for biological measurement. Nevertheless, the responding sample continues in most respects to be representative of the national population of a similar age. Consistency of response over the study's 20 data collections has been high. The size of the sample responding in adulthood is adequate for the study of the major costly diseases, and for the study of functional ageing and its precursors. This study's continuation has depended not only on scientific value but also policy relevance. Although the problems inherent in the prospective design are unavoidable they are not, in the study described, a barrier to scientific and policy value. That seems also likely in Britain's two later born national birth cohort studies that have continued into adulthood.