Standardization and monitoring of laboratory performance and quality assurance by use of the less-sensitive HIV incidence assay: seven years of results.

Background: The Performance Evaluation Program for HIV-1 incidence tests provided quality assurance services to laboratories conducting the serological testing algorithm for recent HIV seroconversion by use of a modified less-sensitive version of the Vironostika HIV-1 MicroElisa System assay. We report on the performance of the assay using proficiency testing and quality control materials tested from 2001 to 2008.

Methods: Two sets of 5 blinded serum panels using common calibration and quality control materials were tested.

HIV-1 RNA rectal shedding is reduced in men with low plasma HIV-1 RNA viral loads and is not enhanced by sexually transmitted bacterial infections of the rectum.

Background: Among human immunodeficiency virus (HIV)-infected men who have sex with men (MSM) taking combination antiretroviral therapy (cART), the impact of rectal sexually transmitted infections (STIs) on rectal HIV-1 shedding is unknown.

Methods: Human immunodeficiency virus type 1 (HIV-1) RNA was quantified from rectal swabs collected for Neisseria gonorrhoeae (GC) and Chlamydia trachomatis (CT) screening of HIV-1-infected MSM. Correlations of STIs with rectal viral load were explored using multinomial regression modeling.

The molecular kink paradigm for rubber elasticity: numerical simulations of explicit polyisoprene networks at low to moderate tensile strains.

Based on recent molecular dynamics and ab initio simulations of small isoprene molecules, we propose a new ansatz for rubber elasticity. We envision a network chain as a series of independent molecular kinks, each comprised of a small number of backbone units, and the strain as being imposed along the contour of the chain. We treat chain extension in three distinct force regimes: (Ia) near zero strain, where we assume that the chain is extended within a well defined tube, with all of the kinks participating simultaneously as entropic elastic springs, (II) when the chain becomes sensibly straight, giving rise to a purely enthalpic stretching force (until bond rupture occurs) and, (Ib) a linear entropic regime, between regimes Ia and II, in which a force limit is imposed by tube deformation.

Infantile choriocarcinoma in a neonate with massive liver involvement cured with chemotherapy and liver transplant.

A 6-week-old boy presented with fever, pallor, and hepatomegaly. Ultrasound showed a huge midline abdominal mass. β-human chorionic gonadotropin was markedly elevated, suggesting a diagnosis of infantile choriocarcinoma of the liver.

Exome sequencing identifies CCDC8 mutations in 3-M syndrome, suggesting that CCDC8 contributes in a pathway with CUL7 and OBSL1 to control human growth.

3-M syndrome, a primordial growth disorder, is associated with mutations in CUL7 and OBSL1. Exome sequencing now identifies mutations in CCDC8 as a cause of 3-M syndrome. CCDC8 is a widely expressed gene that is transcriptionally associated to CUL7 and OBSL1, and coimmunoprecipitation indicates a physical interaction between CCDC8 and OBSL1 but not CUL7.

DNA aptamer beacon assay for C-telopeptide and handheld fluorometer to monitor bone resorption.

A novel DNA aptamer beacon is described for quantification of a 26-amino acid C-telopeptide (CTx) of human type I bone collagen. One aptamer sequence and its reverse complement dominated the aptamer pool (31.6% of sequenced clones).

Delayed maturation of antibody avidity but not seroconversion in rhesus macaques infected with simian HIV during oral pre-exposure prophylaxis.

Background: Pre-exposure prophylaxis (PrEP) is a novel intervention strategy for the prevention HIV transmission. Because several clinical trials are at various stages of completion, it is important to understand the impact of PrEP treatment on the development of the immune response to HIV, particularly in individuals who exhibit breakthrough infections despite PrEP.

Methods: A model of HIV infection, using rhesus macaques and the simian/human immunodeficiency virus (SHIV), was used to evaluate the effects of PrEP on the evolution of the humoral immune response.

Protection against rectal transmission of an emtricitabine-resistant simian/human immunodeficiency virus SHIV162p3M184V mutant by intermittent prophylaxis with Truvada.

Daily preexposure prophylaxis (PrEP) with Truvada (emtricitabine [FTC] and tenofovir disoproxil fumarate [TDF]) is a novel HIV prevention strategy recently found to reduce HIV incidence among men who have sex with men. We used a macaque model of HIV transmission to investigate if Truvada maintains prophylactic efficacy against an FTC-resistant isolate containing the M184V mutation. Five macaques received a dose of Truvada 3 days before exposing them rectally to the simian/human immunodeficiency virus mutant SHIV162p3(M184V), followed by a second dose 2 h after exposure.

Rolled liverwort mats explain major Prototaxites features: Response to commentaries.

In volume 97(2) of the American Journal of Botany (pp. 268-275), we published an article entitled "Structural, physiological, and stable carbon isotopic evidence that the enigmatic Paleozoic fossil Prototaxites formed from rolled liverwort mats". Here, we respond to a letter and a commentary on our article in the present issue, welcoming this opportunity to continue the scientific dialogue about an issue that has long been stimulating and controversial.

The Arabidopsis thaliana aquaporin AtPIP1;2 is a physiologically relevant CO₂ transport facilitator.

Cellular exchange of carbon dioxide (CO₂) is of extraordinary importance for life. Despite this significance, its molecular mechanisms are still unclear and a matter of controversy. In contrast to other living organisms, plants are physiologically limited by the availability of CO₂.

Natural substrate concentrations can modulate the prophylactic efficacy of nucleotide HIV reverse transcriptase inhibitors.

Preexposure prophylaxis (PrEP) with antiretroviral drugs is a novel human immunodeficiency virus (HIV) prevention strategy. It is generally thought that high systemic and mucosal drug levels are sufficient for protection. We investigated whether GS7340, a next-generation tenofovir (TFV) prodrug that effectively delivers tenofovir diphosphate (TFV-DP) to lymphoid cells and tissues, could protect macaques against repeated weekly rectal simian-human immunodeficiency virus (SHIV) exposures.

The Perspectives of Fieldwork Educators Regarding Level II Fieldwork Students.

ABSTRACT Ten occupational therapists employed in pediatric and adult rehabilitation settings participated in focus groups to discuss their perceptions of the benefits and drawbacks in working with occupational therapy students. Participants identified professional values, opportunities for continued professional development, recruitment of future employees, and pride in learning experiences available as incentives for working with students. Fieldwork educators who had supervised students lacking foundational communication, problem-solving, and clinical skills were cautious about accepting future Level II students.

Cognitive-emotional dysfunction among noisy minds: predictions from individual differences in reaction time variability.

Mental noise can be defined as less reliable information processing. Individuals with high levels of mental noise are thought to be disadvantaged in cognitive, emotional, and behavioural realms. The present five studies (total N=298) investigated such potential disadvantages among normally functioning college undergraduates.

Incontinence and incontinence-associated dermatitis.

Incontinence is a prevalent problem and can lead to many complications. Both urinary and fecal incontinence can result in tissue breakdown, now commonly referred to as incontinence-associated dermatitis. This article addresses the types of incontinence, its etiology and pathophysiology, assessment, prevention and treatment, and the latest research.

The distributions of chain lengths in a crosslinked polyisoprene network.

A fundament of classical rubber elasticity theory is the Gaussian chain approximation formula, P(n,r) for the probability distribution of end-to-end distances of a polymer chain composed of n beads. It is considered to provide a realistic distribution of end-to-end distances, r, provided that the length of the polymer chain is much greater than its average end-to-end distance. By considering the number of beads (n) to be the independent variable, we can use P(n,r) to construct the probability distributions of network chain lengths, for fixed r.

Ehrlichia-induced hemophagocytic lymphohistiocytosis in two children.

Two children presented with a history of fever and rash. Lab values revealed pancytopenia, elevated ferritin, coagulopathy, and elevated triglycerides. Both children quickly developed respiratory distress and hypotension requiring admission to the ICU.

Determination of mean recency period for estimation of HIV type 1 Incidence with the BED-capture EIA in persons infected with diverse subtypes.

The IgG capture BED enzyme immunoassay (BED-CEIA) was developed to detect recent HIV-1 infection for the estimation of HIV-1 incidence from cross-sectional specimens. The mean time interval between seroconversion and reaching a specified assay cutoff value [referred to here as the mean recency period (ω)], an important parameter for incidence estimation, is determined for some HIV-1 subtypes, but testing in more cohorts and new statistical methods suggest the need for a revised estimation of ω in different subtypes. A total of 2927 longitudinal specimens from 756 persons with incident HIV infections who had been enrolled in 17 cohort studies was tested by the BED-CEIA.

Shock compression of a fifth period element: liquid xenon to 840 GPa.

Current equation of state (EOS) models for xenon show substantial differences in the Hugoniot above 100 GPa, prompting the need for an improved understanding of xenon's behavior at extreme conditions. We performed shock compression experiments on liquid xenon to determine the Hugoniot up to 840 GPa, using these results to validate density functional theory (DFT) simulations. Despite the nearly fivefold compression, we find that the limiting Thomas-Fermi theory, exact in the high density limit, does not accurately describe the system.

Herpes zoster and meningitis due to reactivation of varicella vaccine virus in an immunocompetent child.

Neurologic complications from varicella zoster virus (VZV) reactivation are rare. In this article, we describe a previously immunized child who developed herpes zoster with meningitis. Vaccine strain of VZV was recovered from a skin swab and the cerebrospinal fluid.

Quantum chemistry and molecular dynamics studies of the entropic elasticity of localized molecular kinks in polyisoprene chains.

We investigate the thermodynamic consequences of the distribution of rotational conformations of polyisoprene on the elastic response of a network chain. In contrast to the classical theory of rubber elasticity, which associates the elastic force with the distribution of end-to-end distances, we find that the distribution of chain contour lengths provides a simple mechanism for an elastic force. Entropic force constants were determined for small contour length extensions of chains constructed as a series of localized kinks, with each kink containing between one and five cis-1,4-isoprene units.

Performance of the Aptima HIV-1 RNA qualitative assay with 16- and 32-member specimen pools.

The Aptima HIV-1 RNA qualitative assay tested with a WHO-approved HIV type 1 RNA standard in 16- and 32-member pools detected 100% of the pools (1,070 and 2,130 HIV-1 RNA copies/ml/pool, respectively), thus exceeding the FDA-required lower limit of detection. The Aptima test can be used to screen for acute-phase HIV infection.

Influence of diurnal variation in mesophyll conductance on modelled 13C discrimination: results from a field study.

Mesophyll conductance to CO(2) (g(m)) limits carbon assimilation and influences carbon isotope discrimination (Delta) under most environmental conditions. Current work is elucidating the environmental regulation of g(m), but the influence of g(m) on model predictions of Delta remains poorly understood. In this study, field measurements of Delta and g(m) were obtained using a tunable diode laser spectroscope coupled to portable photosynthesis systems.

Intermittent prophylaxis with oral truvada protects macaques from rectal SHIV infection.

HIV continues to spread globally, mainly through sexual contact. Despite advances in treatment and care, preventing transmission with vaccines or microbicides has proven difficult. A promising strategy to avoid transmission is prophylactic treatment with antiretroviral drugs before exposure to HIV.

Comparison of distress and pain in infants randomized to groups receiving standard versus multiple immunizations.

This randomized controlled trial compared distress and pain in healthy 4-month-old infants receiving three different immunizations either sequentially (control, n=50) or simultaneously, two at the same time, followed by the third (experimental, n=51). Although both groups demonstrated a significant increase in cortisol from baseline levels, the lack of significant difference on salivary cortisol between groups post-immunization suggests the study was underpowered. On NIPS scores, the experimental group demonstrated significantly less pain (Mann-Whitney U=1648.