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OBJECTIVE. Diffuse excessive high signal intensity (DEHSI) is observed in the majority of preterm infants at term-equivalent age on conventional MRI, and diffusion-weighted imaging has shown that apparent diffusion coefficient values are elevated in the white matter (WM) in DEHSI. Our aim was to obtain diffusion tensor imaging on preterm infants at term-equivalent age and term control infants to test the hypothesis that radial diffusivity was significantly different in the WM in preterm infants with DEHSI compared with both preterm infants with normal-appearing WM on conventional MRI and term control infants. METHODS. Diffusion tensor imaging was obtained on 38 preterm infants at term-equivalent age and 8 term control infants. Values for axial ([[lambda].sub.1]) and radial [([[lambda].sub.2] + [[lambda].sub.3])/2] diffusivity were calculated in regions of interest positioned in the central WM at the level of the centrum semiovale, frontal WM, posterior periventricular WM, occipital WM, anterior and posterior portions of the posterior limb of the internal capsule, and the genu and splenium of the corpus callosum. RESULTS. Radial diffusivity was elevated significantly in the posterior portion of the posterior limb of the internal capsule and the splenium of the corpus callosum, and both axial and radial diffusivity were elevated significantly in the WM at the level of the centrum semiovale, the frontal WM, the periventricular WM, and the occipital WM in preterm infants with DEHSI compared with preterm infants with normal-appearing WM and term control infants. There was no significant difference between term control infants and preterm infants with normal-appearing WM in any region studied. CONCLUSIONS. These findings suggest that DEHSI represents an oligodendrocyte and/or axonal abnormality that is widespread throughout the cerebral WM. Key Words preterm, brain, diffusion tensor imaging, magnetic resonance imaging Abbreviations GA--gestational age DEHSI--diffuse excessive high signal intensity DWI--diffusion-weighted imaging ADC--apparent diffusion coefficient WM--white matter DTI--diffusion tensor imaging PLIC--posterior limb of the internal capsule PMA--postmenstrual age FOV--field of view ROI--region of interest, THE DEVELOPING BRAIN is vulnerable to injury from many causes, resulting in significant mortality and morbidity. At 30 months of age, impairment can be identified in one half of all [...]

A study is conducted to establish the importance of commercial sex in driving the HIV epidemic in the general population by determining risk factors for HIV infection among male mine and farm workers and estimating the fraction of prevalent HIV infection attributable to sexual contact with sex workers (SWs). The results indicate that a large proportion of HIV infection in men is attributed to sexual contact with SWs.

Three hundred sixty-three sex workers were recruited from five commercial farms and two mines in Marshonaland West, Zimbabwe and each participant had blood tested for antibody of HIV, herpes simplex virus 2 (HSV-2) and syphilis. The overall prevalence of antibody to HIV was found to be 55.7%.

Objective. The most common finding on magnetic resonance imaging (MRI) of the brain in preterm infants at term-equivalent age is diffuse excessive high signal intensity (DEHSI) in the white matter. It is unclear whether DEHSI represents a biological abnormality. This study used diffusion-weighted imaging (DWI) to compare apparent diffusion coefficient (ADC) values in DEHSI with infants with normal imaging and those with overt brain damage to determine whether DEHSI shows the diffusion characteristics of normal or abnormal tissue. Methods. MRI, using conventional and diffusion-weighted imaging (DWI), was performed in 50 preterm infants at term-equivalent age using a 1.5 Tesla MR scanner. The infants were divided into 3 groups on the basis of their MRI results: 1) normal white matter, 2) DEHSI, or 3) overt white matter pathology. ADC values were measured in the frontal, central, and posterior white matter at the level of the centrum semiovale. ADC values in the 3 groups of preterm infants were compared using a 1-way analysis of variance with a Bonferroni test for multiple comparisons. Results. ADC values were significantly higher in infants with DEHSI and infants with overt white matter pathology than in infants with normal white matter. There was no significant difference between ADC values in infants with DEHSI and those with overt white matter pathology. Conclusions. This study provides objective evidence that DEHSI represents diffuse white matter abnormality., ABBREVIATIONS. PVL, periventricular leukomalacia; PHI, periventricular hemorrhagic infarction; IVH, intraventricular hemorrhage; MRI, magnetic resonance imaging; DEHSI, diffuse excessive high signal intensity; DWI, diffusion-weighted imaging; ADC, apparent diffusion coefficient; GA, gestational [...]

Introduction: Of the two million new HIV infections in adults in 2014, 70% occurred in sub-Saharan Africa. Several African countries have already approved guidelines for pre-exposure prophylaxis (PrEP) for individuals at substantial risk of HIV as part of combination HIV prevention but key questions remain about how to identify and deliver PrEP to those at greatest need. Throughout the continent, individuals in sero-discordant relationships, and members of key populations (sex workers, men who have sex with men (MSM), transgender women and injection drug users) are likely to benefit from the availability of PrEP. In addition, adolescent girls and young women (AGYW) are at substantial risk in some parts of the continent. It has been estimated that at least three million individuals in Africa are likely to be eligible for PrEP according to WHO's criteria. Tens of demonstration projects are planned or underway across the continent among a range of countries, populations and delivery settings. Discussion: In each of the target populations, there are overarching issues related to (i) creating demand for PrEP, (ii) addressing supply-side issues and (iii) providing appropriate and tailored adherence support. Critical for creating demand for PrEP is the normalization of HIV prevention. Community-level interventions which engage opinion leaders as well as empowerment interventions for those at highest risk will be key. Critical to supply of PrEP is that services are accessible for all, including for stigmatized populations. Establishing accessible integrated services provides the opportunity to address other public health priorities including the unmet need for HIV testing, contraception and sexually transmitted infections treatment. National policies need to include minimum standards for training and quality assurance for PrEP implementation and to address supply chain issues. Adherence support needs to recognize that social and structural factors are likely to have an important influence. Combining interventions that build self-efficacy, empowerment and social cohesion, with evidence-based individualized adherence support for PrEP, are most likely to be effective. Conclusions: Efficacy of tenfovir-based PrEP is proven but many issues related to implementation remain unclear. Here, we have summarized some of the important implementation questions that need to be assessed as PrEP is rolled out across Africa. Keywords: empowerment; key populations; HIV/AIDS; pre-exposure prophylaxis; prevention; Africa; adherence; implementation., Introduction Of the two million new HIV infections in adults in 2014, 70% occurred in sub-Saharan Africa (SSA). With the scale-up of antiretroviral treatment (ART), the number of new infections [...]

An abnormal signal intensity on a magnetic resonance image (MRI) of the brain of newborns with hypoxic-ischemic encephalopathy (HIE) may predict a poor neurodevelopmental outcome. HIE can develop when infants do not get sufficient oxygen during the birthing process. Researchers evaluated MRIs of the posterior limb of the internal capsule (PLIC) of the brain in 73 newborns with HIE, and found that all infants with abnormal images in this brain region were neurologically impaired. Eighty-eight percent of infants with normal MRIs of the PLIC developed normally., Objective. The aim of this study was to establish whether abnormal signal intensity in the posterior limb of the internal capsule (PLIC) on magnetic resonance imaging is an accurate predictor of neurodevelopmental outcome at 1 year of age in infants with hypoxic-ischemic encephalopathy (HIE). Methods. We have examined 73 term neonates with HIE between 1 and 17 days after birth with cranial magnetic resonance imaging and related the magnetic resonance imaging findings to neurodevelopmental outcome at 1 year of age. Results. All infants with an abnormal signal intensity in the PLIC developed neurodevelopmental impairment although in 4 infants with very early scans the abnormal signal was not apparent until up to 4 days after birth. A normal signal intensity was associated with a normal outcome in all but 4 cases; 3 of these infants had minor impairments and all had persistent imaging changes within the white matter. The 4th infant with a normal signal intensity on day 2 died before a further image could be obtained. The absence of normal signal predicted abnormal outcome in term infants with HIE with a sensitivity of 0.90, a specificity of 1.0, a positive predictive value of 1.0, and a negative predictive value of 0.87. The test correctly predicted outcome in 93% of infants with grade II HIE, according to the Sarnat system. Applying a Bayesian approach, the predictive probability of the test (the probability that the test would predict an outcome correctly) was distributed with a mean of 0.94 and 95% confidence limits of 0.89 to 1.0. Conclusion. Abnormal signal intensity in the PLIC is an accurate predictor of neurodevelopmental outcome in term infants suffering HIE. Pediatrics 1998;102:323-328; hypoxic-ischemic encephalopathy, magnetic resonance imaging, internal capsule, neurodevelopmental outcome., ABBREVIATIONS. MRI, magnetic resonance imaging; HIE, hypoxic-ischemic encephalopathy; PLIC, posterior limb of the internal capsule; T1WSE, T1-weighted spin echo; T2WSE, T2-weighted spin echo; IR, inversion recovery; DQ, developmental quotient. Magnetic [...]