Development of Methods for Cross-Sectional HIV Incidence Estimation in a Large,Community Randomized Trial

Background

Accurate methods of HIV incidence determination are critically needed to monitor the epidemic and determine the population level impact of prevention trials. One such trial, Project Accept, a Phase III, community-randomized trial, evaluated the impact of enhanced, community-based voluntary counseling and testing on population-level HIV incidence. The primary endpoint of the trial was based on a single, cross-sectional, post-intervention HIV incidence assessment.

Methods and Findings

Test performance of HIV incidence determination was evaluated for 403 multi-assay algorithms [MAAs] that included the BED capture immunoassay [BED-CEIA] alone, an avidity assay alone, and combinations of these assays at different cutoff values with and without CD4 and viral load testing on samples from seven African cohorts (5,325 samples from 3,436 individuals with known duration of HIV infection [1 month to >10 years]). The mean window period (average time individuals appear positive for a given algorithm) and performance in estimating an incidence estimate (in terms of bias and variance) of these MAAs were evaluated in three simulated epidemic scenarios (stable, emerging and waning). The power of different test methods to detect a 35% reduction in incidence in the matched communities of Project Accept was also assessed. A MAA was identified that included BED-CEIA, the avidity assay, CD4 cell count, and viral load that had a window period of 259 days, accurately estimated HIV incidence in all three epidemic settings and provided sufficient power to detect an intervention effect in Project Accept.

Conclusions

In a Southern African setting, HIV incidence estimates and intervention effects can be accurately estimated from cross-sectional surveys using a MAA. The improved accuracy in cross-sectional incidence testing that a MAA provides is a powerful tool for HIV surveillance and program evaluation.     

Movements and flight morphology in the endangered Large Blue butterflies

Movements and flight morphology of the endangered Large Blue butterflies Phengaris teleius and P. nausithous in southern Poland were studied with mark-release-recapture surveys and GIS analyses. Most individuals moved relatively small distances (<40 metres) within their habitat patches. Distances covered by both species were positively related to season progression and wing length, and negatively related to body mass. P. teleius movement distances slightly exceeded those of P. nausithous. In addition, females moved longer distances than males, although the difference was significant only in P. teleius. Morphological traits appeared to be good indicators of the inter-specific and inter-sexual differences in mobility. While P. teleius individuals were heavier than P. nausithous ones, they had considerably longer wings, which may explain longer movements in the former species. Similarly, females were heavier than males in both species, but they invested more in wing size, which is likely to compensate for the negative impact of body mass on movement distances. Our results indicate that combination of GIS analysis of movement distances recorded with mark-release-recapture methods and morphometric measurements taken in field during non-lethal handling of captured individuals proved useful for studying the mobility potential of the endangered insect species.     

Cerebral Developmental Abnormalities in a Mouse with Systemic Pyruvate Dehydrogenase Deficiency

Pyruvate dehydrogenase (PDH) complex (PDC) deficiency is an inborn error of pyruvate metabolism causing a variety of neurologic manifestations. Systematic analyses of development of affected brain structures and the cellular processes responsible for their impairment have not been performed due to the lack of an animal model for PDC deficiency. METHODS: In the present study we investigated a murine model of systemic PDC deficiency by interrupting the X-linked Pdha1 gene encoding the α subunit of PDH to study its role on brain development and behavioral studies. RESULTS: Male embryos died prenatally but heterozygous females were born. PDC activity was reduced in the brain and other tissues in female progeny compared to age-matched control females. Immunohistochemical analysis of several brain regions showed that approximately 40% of cells were PDH⁻. The oxidation of glucose to CO₂ and incorporation of glucose-carbon into fatty acids were reduced in brain slices from 15 day-old PDC-deficient females. Histological analyses showed alterations in several structures in white and gray matters in 35 day-old PDC-deficient females. Reduction in total cell number and reduced dendritic arbors in Purkinje neurons were observed in PDC-deficient females. Furthermore, cell proliferation, migration and differentiation into neurons by newly generated cells were reduced in the affected females during pre- and postnatal periods. PDC-deficient mice had normal locomotor activity in a novel environment but displayed decreased startle responses to loud noises and there was evidence of abnormal pre-pulse inhibition of the startle reflex. CONCLUSIONS: The results show that a reduction in glucose metabolism resulting in deficit in energy production and fatty acid biosynthesis impairs cellular differentiation and brain development in PDC-deficient mice.     

Geldanamycin-Induced Osteosarcoma Cell Death Is Associated with Hyperacetylation and Loss of Mitochondrial Pool of Heat Shock Protein 60 (Hsp60)

Osteosarcoma is one of the most malignant tumors of childhood and adolescence that is often resistant to standard chemo- and radio-therapy. Geldanamycin and geldanamycin analogs have been recently studied as potential anticancer agents for osteosarcoma treatment. Here, for the first time, we have presented novel anticancer mechanisms of geldanamycin biological activity. Moreover, we demonstrated an association between the effects of geldanamycin on the major heat shock proteins (HSPs) and the overall survival of highly metastatic human osteosarcoma 143B cells. We demonstrated that the treatment of 143B cells with geldanamycin caused a subsequent upregulation of cytoplasmic Hsp90 and Hsp70 whose activity is at least partly responsible for cancer development and drug resistance. On the other hand, geldanamycin induced upregulation of Hsp60 gene expression, and a simultaneous loss of hyperacetylated Hsp60 mitochondrial protein pool resulting in decreased viability and augmented cancer cell death. Hyperacetylation of Hsp60 seems to be associated with anticancer activity of geldanamycin. In light of the fact that mitochondrial dysfunction plays a critical role in the apoptotic signaling pathway, the presented data may support a hypothesis that Hsp60 can be another functional part of mitochondria-related acetylome being a potential target for developing novel anticancer strategies.     

Drivers of plant species composition in alder-dominated forests with contrasting connectivity

The effects of local and regional environmental variables as well as spatial gradients on the plant species composition of two types of alder-dominated forests (riparian forests and alder carrs) with contrasting connectivity were studied across the Western Carpathians from Hungary through Slovakia to Poland. We used large vegetation (240 sampling plots) and environmental (24 variables) datasets, which were accompanied by spatial variables represented by principal coordinates of neighbour matrices. Canonical correspondence analysis (CCA) of the two datasets revealed 13 and 29 variables with significant effects on variation in species composition of alder carrs and riparian alder forests, which jointly explained 41.2% and 36.4% of the variability, respectively. Altitude was the most important factor explaining 7.7% of the variability in the species composition of alder carrs and 8.2% in riparian alder forests. Variation partitioning in CCA revealed that local variables were crucial drivers for species composition patterns in alder carrs, while spatial processes unrelated to the measured environmental variables shaped the vegetation structure of riparian forests.

     

Expressions of <Emphasis Type="Italic">per1</Emphasis> Clock Gene and Genes of Signaling Peptides Vasopressin,Vasoactive Intestinal Peptide,and Oxytocin in the Suprachiasmatic and Paraventricular Nuclei of Hypertensive TGR[mREN2]27 Rats

Hypertensive rats with multiple extra copies of the renin gene (TGR) exert an inverted circadian blood pressure (BP) profile. We investigated whether circadian oscillations in the hypothalamic suprachiasmatic nucleus (SCN), a main circadian oscillator, and the paraventricular nucleus (PVN), involved in BP control, are influenced in TGR rats. The expression of the clock gene per1, a marker of circadian timing, was measured in the SCN and PVN. Moreover, the expression of genes encoding vasopressin (AVP), vasoactive intestinal peptide (VIP) in the SCN, and AVP and oxytocin (OXT) in the PVN were studied by in situ hybridization. Expression of the per1 gene showed a distinct circadian rhythm in both the SCN and PVN with no differences observed between the TGR and control Sprague–Dawley (SD) rats. The expression of avp in the SCN was rhythmic in both strains and moderately higher in TGR than in SD rats while no significant changes were found in the PVN. The expression of vip in the SCN and oxt in the PVN did not differ between both strains. Our results may indicate that changes occurring downstream to the SCN are responsible for the development of the inverted BP rhythm in TGR hypertensive rats.     

Role of FAT/CD36 in novel PKC isoform activation in heart of spontaneously hypertensive rats

Disruption to the sensitive balance of long-chain fatty acids and glucose in the heart could cause cardiovascular diseases. Searching for a possible role of novel protein kinase C (nPKC) in heart with disrupted energy balance, we compared the insulin-resistant spontaneously hypertensive rats (SHR), which carry a nonfunctional variant of the fatty acid transporter FAT/CD36, with the less insulin-resistant congenic strain SHR-4 that is genetically identical except for a segment on chromosome 4 including a wild-type gene for a functional FAT/CD36. We analyzed expression of the nPKC-δ and -ε isoforms plus triacylglycerols (TAG) content in the myocardium of both FAT/CD36 strains and after a high sucrose diet (HSD). Two weeks before killing, males of both strains were randomly divided into two groups and fed either a standard laboratory chow or an HSD. PKC was determined by Western blotting in particulate and cytosolic fractions from left ventricles. The SHR-4 rats exhibited lower serum levels of insulin and free fatty acids than did SHR rats and higher amounts of PKC-ε in the heart particulate fraction. HSD caused accumulation of heart TAG in SHR but not in SHR-4. HSD increased PKC-δ and decreased PKC-ε expression in particulate fraction from left ventricles of SHR-4 while having no effects in SHR. These results demonstrate that reduced insulin resistance in SHR-4 rats with wild-type FAT/CD36 is associated with the insulin signaling pathway involving nPKCs.