Provider barriers to the uptake of isoniazid preventive therapy among people living with HIV in Ethiopia.

SETTING: Sixty-seven government health facilities providing tuberculosis (TB) and human immunodeficiency virus (HIV) services across Ethiopia. OBJECTIVE: To examine clinician barriers to implementing isoniazid preventive therapy (IPT) among people living with HIV. DESIGN: A cross-sectional study to evaluate the provider-related factors associated with high IPT coverage at the facility level. RESULTS: On bivariate analysis, the odds of high IPT implementation were lower when clinicians felt patients were negatively affected by the side effects of IPT (OR 0.18, 95%CI 0.04-0.81) and perceived that IPT increased multidrug-resistant TB (MDR-TB) rates (OR 0.66, 95%CI 0.44-0.98). The presence of IPT guidelines on site (OR 2.93, 95%CI 1.10-7.77) and TB-HIV training (OR 3.08, 95%CI 1.11-8.53) had a positive relationship with high IPT uptake. In the multivariate model, clinician's perception that active TB was difficult to rule out had a negative association with a high IPT rate (OR 0.93; 95%CI 0.90-0.95). CONCLUSIONS: Clinician impression that ruling out active TB among HIV patients is difficult was found to be a significant barrier to IPT uptake. Continued advancement of IPT relies greatly on improving the ability of providers to determine IPT eligibility and more confidently care for patients on IPT. Improved clinician support and training as well as development of new TB diagnostic technologies could impact IPT utilization among providers.

Factors promoting and inhibiting sustained impact of a mental health task-shifting program for HIV providers in Ethiopia.

BACKGROUND: Task-shifting mental health into general medical care requires more than brief provider training. Generalists need long-term support to master new skills and changes to work context are required to sustain change in the face of competing priorities. We examined program and context factors promoting sustainability of a mental health task-shifting training for hospital-based HIV providers in Ethiopia. METHODS: Convergent mixed-methods quasi-experimental study. Sustained impact was measured by trained/not-trained provider differences in case detection and management 16 months following the end of formal support. Factors related to sustainability were examined through interviews with trained providers. RESULTS: Extent of sustained impact: Trained providers demonstrated modest but better agreement with standardized screeners (greater sensitivity with similar specificity). They were more likely to request that patients with mental health problems return to see them v. making a referral. Factors promoting sustainability (reported in semi-structured interviews): provider belief that the treatments they had learned were effective. New interactions with on-site mental health staff were a source of ongoing learning and encouragement. Factors diminishing sustainability: providers feelings of isolation when mental health partners left for work elsewhere, failure to incorporate mental health indicators into administrative data, to re-stock staff education materials, and to build formal mechanisms for generalist-mental health staff interaction. CONCLUSIONS: An intervention seen as feasible and effective, and promotion of relationships across professional lines, helped generalists sustain new skills. Failure to address key system context issues made use of the skills unsustainable as external supports ended.

Primary α and secondary ß relaxation dynamics of meta-toluidine in the liquid state investigated by broadband dielectric spectroscopy.

We report a broadband dielectric spectroscopic (BDS) study on the clustering fragile glass-former meta-toluidine (m-TOL) from 187 K up to 289 K over a wide frequency range of 10-3-109 Hz with focus on the primary α relaxation and the secondary ß relaxation above the glass temperature Tg. The broadband dielectric spectra were fitted by using the Havriliak-Negami (HN) and Cole-Cole (CC) models. The ß process disappearing at Tß,disap = 1.12Tg exhibits non-Arrhenius dependence fitted by the Vogel-Fulcher-Tamman-Hesse equation with T0ßVFTH in accord with the characteristic differential scanning calorimetry (DSC) limiting temperature of the glassy state. The essential feature of the α process consists in the distinct changes of its spectral shape parameter ßHN marked by the characteristic BDS temperatures TB1ßHN and TB2ßHN. The primary α relaxation times were fitted over the entire temperature and frequency range by several current three-parameter up to six-parameter dynamic models. This analysis reveals that the crossover temperatures of the idealized mode coupling theory model (TcMCT), the extended free volume model (T0EFV), and the two-order parameter (TOP) model (Tmc) are close to TB1ßHN, which provides a consistent physical rationalization for the first change of the shape parameter. In addition, the other two characteristic TOP temperatures T0TOP and TA are coinciding with the thermodynamic Kauzmann temperature TK and the second change of the shape parameter at around TB2ßHN, respectively. These can be related to the onset of the liquid-like domains in the glassy state or the disappearance of the solid-like domains in the normal liquid state.

Dielectric properties of complex magnetic field induced states in PbCuSO4(OH)2.

Spin spirals, which coexist with collinear spin order in linarite PbCuSO4(OH)2, indicate electrical polarisation textures of spin-multipolar phases. We derive experimental evidence by a detailed investigation of the magnetic-field dependent dielectric and electric polarization properties at low temperatures. Linarite exhibits a quasi-one-dimensional frustrated S = ½ spin chain, which forms 3D spin-spiral order in zero magnetic field for T < 2.85 K. Recently, due to the monoclinic lattice of linarite with CuO2 ribbon chains, complex magnetic field induced states were found. These spin-multipolar phases, which compete with spin-density waves at low magnetic fields, exist in close vicinity to the transition from the spin spiral into field induced spin polarized state. Via antisymmetric Dzyaloshinskii-Moriya interaction spin-driven ferroelectricity develops in the spin-spirals state. Via electric polarization measurements this allows to prove the transitions into complex magnetic field induced phases. Thorough analyses of the temperature and magnetic field dependent dielectric properties of a naturally grown single crystalline sample provide a detailed (T,H) phase diagrams for the three different crystallographic directions.

Tuberculosis along the continuum of HIV care in a cohort of adolescents living with HIV in Ethiopia.

SETTING: Eight health facilities in Ethiopia. OBJECTIVE: To determine tuberculosis (TB) incidence rates and associated factors among adolescents living with the human immunodeficiency virus (ALHIV). DESIGN: This was a retrospective cohort study. Adolescents enrolled in HIV care between January 2005 and 31 December 2013 constituted the study population. The main outcome variable was TB diagnosis during follow-up. Baseline World Health Organization (WHO) clinical stage, CD4 count, previous history of TB and use of isoniazid preventive therapy (IPT) were the main independent variables. We estimated TB incidence rates as incident cases per 100 person-years of observation (PYO). Cox regression analysis was used to control for confounders. RESULTS: Of the 1221 adolescents screened, 1072 were studied; 60.1% were girls. TB incidence rate was 16.32 per 100 PYO during pre-antiretroviral therapy (pre-ART) follow-up but declined to 2.25 per 100 PYO after initiation of ART. Advanced WHO clinical stage (adjusted hazard ratio [aHR] 2.71, 95%CI 1.69-4.33) and CD4 count <350 cells/µl (aHR 2.28, 95%CI 1.10-4.81) predicted TB incidence in the pre-ART cohort. IPT use was associated with a significant reduction in TB incidence in the ART cohort, but not in the pre-ART group. CONCLUSION: Although TB was a significant problem in ALHIV, timely administration of ART and IPT had a significant protective effect.

A whole cell biocatalyst for double oxidation of cyclooctane.

A novel whole cell cascade for double oxidation of cyclooctane to cyclooctanone was developed. The one-pot oxidation cascade requires only a minimum of reaction components: resting E. coli cells in aqueous buffered medium (=catalyst), the target substrate and oxygen as environmental friendly oxidant. Conversion of cyclooctane was catalysed with high efficiency (50% yield) and excellent selectivity (>94%) to cyclooctanone. The reported oxidation cascade represents a novel whole cell system for double oxidation of non-activated alkanes including an integrated cofactor regeneration. Notably, two alcohol dehydrogenases from Lactobacillus brevis and from Rhodococcus erythropolis with opposite cofactor selectivities and one monooxygenase P450 BM3 were produced in a coexpression system in one single host. The system represents the most efficient route with a TTN of up to 24363 being a promising process in terms of sustainability as well.

Two-spinon and orbital excitations of the spin-Peierls system TiOCl.

We combine high-resolution resonant inelastic x-ray scattering with cluster calculations utilizing a recently derived effective magnetic scattering operator to analyze the polarization, excitation energy, and momentum-dependent excitation spectrum of the low-dimensional quantum magnet TiOCl in the range expected for orbital and magnetic excitations (0-2.5 eV). Ti 3d orbital excitations yield complete information on the temperature-dependent crystal-field splitting. In the spin-Peierls phase we observe a dispersive two-spinon excitation and estimate the inter- and intradimer magnetic exchange coupling from a comparison to cluster calculations.

Tribromophenol and pentachlorophenol uptake from sawdust to horticultural products.

This paper presents a study of the uptake of 2,4,6-tribromophenol (TBP), pentachlorophenol (PCP), and its metabolite pentachloroanisole (PCA) from contaminated sawdust from the forest industry in horticultural products such as apples, raspberries, and fodder maize for cattle feed. The samples were obtained from Bio-Bio Province in South Chile between 2002 and 2006. The analytical parameters of the methodology applied to the different matrices are presented and discussed. The chromatographic method was applied to determine the residues in 413 horticultural product samples. Eleven per cent of fodder maize samples showed detectable or quantifiable levels of PCP, TBP or PCA, 3% of samples presented quantifiable levels, although the concentrations surpassed the maximum allowed concentrations for vegetables (>10 microg kg(-1)) in only two samples. Traces of TBP were detected in eight samples, PCA was detected in 15, and PCP in 14 samples. Based on these results, a risk analysis was performed, indicating a low probability, 0.4% for PCA, 1.6% for TBP and 1.9% for PCP, to find concentrations higher than the allowed maximum. For apples and raspberries, no residues of these compounds were detected. These results indicate that those cultivars directly exposed to sawdust, like fodder maize, could contain detectable residues in several samples. To confirm this observation, a field assay was performed on fodder maize cultivated in the presence of sawdust artificially contaminated with 30 mg of TBP and/or PCP under controlled conditions. The results showed that under the experimental conditions used in the study, TBP can be transferred from sawdust to the plant, with an uptake rate of 0.04% from the TBP applied initially with sawdust but not to the corn ear. Also, the degradation of PCP to PCA was observed in the soil.

Profiling the interface electron gas of LaAlO3/SrTiO3 heterostructures with hard x-ray photoelectron spectroscopy.

The conducting interface of LaAlO3/SrTiO3 heterostructures has been studied by hard x-ray photoelectron spectroscopy. From the Ti 2p signal and its angle dependence we derive that the thickness of the electron gas is much smaller than the probing depth of 4 nm and that the carrier densities vary with increasing number of LaAlO3 overlayers. Our results point to an electronic reconstruction in the LaAlO3 overlayer as the driving mechanism for the conducting interface and corroborate the recent interpretation of the superconducting ground state as being of the Berezinskii-Kosterlitz-Thouless type.

TCDD deregulates contact inhibition in rat liver oval cells via Ah receptor, JunD and cyclin A.

The aryl hydrocarbon receptor (AhR) is a transcription factor involved in physiological processes, but also mediates most, if not all, toxic responses to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Activation of the AhR by TCDD leads to its dimerization with aryl hydrocarbon nuclear translocator (ARNT) and transcriptional activation of several phase I and II metabolizing enzymes. However, this classical signalling pathway so far failed to explain the pleiotropic hazardous effects of TCDD, such as developmental toxicity and tumour promotion. Thus, there is an urgent need to define genetic programmes orchestrated by AhR to unravel its role in physiology and toxicology. Here we show that TCDD treatment of rat liver oval cells leads to induction of the transcription factor JunD, resulting in transcriptional upregulation of the proto-oncogene cyclin A which finally triggers a release from contact inhibition. Ectopic expression of cyclin A in confluent cultures overcomes G(1) arrest, indicating that increased cyclin A levels are indeed sufficient to bypass contact inhibition. Functional interference with AhR-, but not with ARNT, abolished TCDD-induced increase in JunD and cyclin A and prevented loss of contact inhibition. In summary, we have discovered a novel AhR-dependent and probably ARNT-independent signalling pathway involving JunD and cyclin A, which mediates TCDD-induced deregulation of cell cycle control.

A stable latent reservoir for HIV-1 in resting CD4(+) T lymphocytes in infected children.

HIV-1 persists in a latent state in resting CD4(+) T lymphocytes of infected adults despite prolonged highly active antiretroviral therapy (HAART). To determine whether a latent reservoir for HIV-1 exists in infected children, we performed a quantitative viral culture assay on highly purified resting CD4(+) T cells from 21 children with perinatally acquired infection. Replication-competent HIV-1 was recovered from all 18 children from whom sufficient cells were obtained. The frequency of latently infected resting CD4(+) T cells directly correlated with plasma virus levels, suggesting that in children with ongoing viral replication, most latently infected cells are in the labile preintegration state of latency. However, in each of 7 children who had suppression of viral replication to undetectable levels for 1-3 years on HAART, latent replication-competent HIV-1 persisted with little decay, owing to a stable reservoir of infected cells in the postintegration stage of latency. Drug-resistance mutations generated by previous nonsuppressive regimens persisted in this compartment despite more than 1 year of fully suppressive HAART, rendering untenable the idea of recycling drugs that were part of failed regimens. Thus the latent reservoir for HIV-1 in resting CD4(+) T cells will be a major obstacle to HIV-1 eradication in children.

Short-term effects of large-dose vitamin A supplementation on viral load and immune response in HIV-infected women.

Vitamin A supplementation has been suggested for treatment and prevention of HIV infection. However, some in vitro data indicate that vitamin A may activate HIV. Randomly, 40 HIV-seropositive women of reproductive age were allocated to receive a single oral dose of 9900 micromol (300,000 IU) vitamin A or placebo. Plasma HIV-1 RNA concentration, total lymphocytes, selected lymphocyte subsets and activation markers, and in vitro lymphocyte proliferation to phytohemagglutinin (PHA) and Candida were measured before dosing and at various time points over an 8-week follow-up period. No differences were found between treatment groups in the frequency of signs or symptoms of acute vitamin A toxicity, nor were differences evident in any lymphocyte subset or activation marker at any time during follow-up. Mean and median viral load concentration at each time point and change in viral load from baseline to each follow-up point did not differ between treatment groups. No difference was measured between treatment groups in the proportion of women who responded to PHA or Candida. This study provides no evidence that high dose vitamin A supplementation of HIV-infected women is associated with significant clinical or immunologic adverse effects.

Induction of stress-activated protein kinases/c-Jun N-terminal kinases by the p55 tumour necrosis factor receptor does not require sphingomyelinases.

Ceramide has been implicated in the activation of stress-activated protein kinases/c-Jun N-terminal kinases (SAPK/JNK). Binding of tumour necrosis factor (TNF) to its 55 kDa receptor (TR55) leads to the generation of ceramide through activation of either acid or neutral sphingomyelinase (A/N-SMase) as well as to potent activation of SAPK/JNK. We have examined a putative role of both N- and A-SMase in the TR55-dependent activation of SAPK/JNK. The analysis of TR55 deletion mutants expressed in 70Z/3 pre-B cells revealed that activation of SAPK/JNK occurs independently of N-SMase. Although both SAPK/JNK and A-SMase are activated by the death domain of TR55, pharmacological prevention of the TR55-dependent activation of A-SMase, or proteolytic degradation of A-SMase in 70Z/3 cells, did not impair SAPK/JNK activation, indicating that SAPK/JNK are not secondary to A-SMase. In addition, proteolytic degradation of A-SMase also did not affect SAPK/JNK activation by ultraviolet (UV-C) irradiation, arguing against a general role of A-SMase in stress-mediated responses. Furthermore, fibroblasts from Niemann-Pick A patients deficient in A-SMase did not show altered activation of SAPK/JNK in response to either TNF or UV-C. These results suggest that TR55 can activate SAPK/JNK without direct participation of sphingomyelinases or ceramide.

Cultural feasibility studies in preparation for clinical trials to reduce maternal-infant HIV transmission in Haiti.

A cultural feasibility study is defined as one that investigates scientific as well as ethical, behavioral, and social issues in the design of clinical trials. The value of such a broadly defined assessment is illustrated through the presentation of two case studies conducted to prepare for clinical trials to reduce maternal-infant HIV transmission on Cité Soleil, Haiti. The first study addressed issues surrounding a trial of breast-feeding and exclusive bottle-feeding among HIV seropositive mothers. The second study focused on the implementation of a double-blind trial of HIV immune globulin and standard immune globulin to be administered to infants of seropositive mothers shortly after birth. Both cases used focus group interviews with mothers and in-depth interviews with key informants to investigate AIDS-related beliefs, acceptability of trial participation, risks to subjects, and community reactions and repercussions to the trial. Findings point to the difficulties posed by attempts to conduct trial involving complex research designs in socially disadvantaged populations. Recommendations highlight the need to consider the community-wide impact of a trial, and the need to undertake extensive educational preparation of participants to ensure informed consent and adherence to protocols.

PIP: Cultural feasibility studies use ethnographic methods to explore ethical, behavioral, and social issues inherent in the design of proposed clinical trials. This approach was applied in advance of clinical trials aimed at reducing maternal-infant HIV transmission in Cite Soleil, Haiti. The first focused on conditions that would be necessary to conduct a trial of breast feeding versus exclusive bottle feeding by HIV-positive mothers; the second investigated the feasibility of a double-blind trial of administration of a high- titer antibody preparation--HIV immune globulin (HIVIG)--to infants of seropositive mothers shortly after birth. Study methods included focus group discussions with mothers and in-depth interviews with key informants about AIDS-related beliefs, acceptability of trial participation, risks to subjects, and community repercussions. Concerns identified included the potential negative effect on breast feeding promotion efforts in Haiti, the scarcity of economic means to sustain safe bottle feeding, the risk of being labeled HIV-positive by virtue of study participation, the potential for the HIVIG trial to reinforce the misconception that a vaccine effective against AIDS exists, and problems explaining the concept of a double-blind study and accepting random assignment to treatment and control groups. As a result of these studies, it was decided to conduct the infant feeding study in a community with higher rates of exclusive bottle feeding and lower infant mortality than exist in Cite Soleil. The HIVIG trial could be conducted, but only after extensive community education to ensure informed consent. An objective assessment of subject comprehension was developed for this purpose.

The enhanced immune response to the HIV gp160/LAMP chimeric gene product targeted to the lysosome membrane protein trafficking pathway.

The lysosome-associated membrane proteins (LAMP), found in the outer membrane of lysosomes and also in a multilaminar compartment that contains major histocompatibility complex class II (MHC II) proteins, are directed to their localization by a cytoplasmic carboxyl-terminal sequence. Our studies of the immune response to LAMP-targeted proteins has led to the application of a HIV-1 gp160/LAMP chimeric gene as a novel means to enhance the MHC II presentation of gp160. Immunofluorescence microscopy confirmed that the gp160/LAMP protein had a cellular localization corresponding to that of lysosomes. Pulse-chase analysis confirmed that the rates of synthesis of gp160/LAMP and wild type gp160 were comparable and that both proteins were processed to gp120 at similar rates. However, the gp160/LAMP was degraded more rapidly than the wild type gp160. MHC II-mediated T cell proliferation assays performed with cloned human cell lines showed that gp160/LAMP stimulated greater responses than did the wild type gp160. Moreover, mice vaccinated with recombinant vaccinia expressing gp160/LAMP had greater gp160-specific lymphoproliferation responses and higher titers of anti-V3 loop antibodies than mice vaccinated with recombinant vaccinia expressing wild type gp160.

A novel cytoplasmic domain of the p55 tumor necrosis factor receptor initiates the neutral sphingomyelinase pathway.

The human p55 tumor necrosis factor (TNF) receptor (TR55) initiates at least two independent signaling cascades. The acidic sphingomyelinase (A-SMase) pathway involves a phosphatidylcholine-specific phospholipase C, an endosomal A-SMase, and controls expression of multiple TNF-responsive genes through induction of transcription factors such as NF-kappaB. The neutral sphingomyelinase (N-SMase) pathway comprises a membrane-bound N-SMase, proline-directed protein kinases, as well as phospholipase A2 and appears critical for the inflammatory responses induced by TNF. While the domain of TR55 that induces A-SMase is probably identical to the death domain, the exact location and extent of a putative N-SMase activation domain are still unknown. Structure-function analysis of TR55 deletion mutants revealed a novel region of 11 amino acids at position 309-319 that is both necessary and sufficient for activation of N-SMase. The N-SMase activation domain is distinct from the death domain and incapable of induction of A-SMase, NF-kappaB, and cytotoxicity. Taken together, our results suggest that a functionally independent region of TR55 is responsible for selectively initiating the N-SMase pathway that couples to an important inflammatory signaling cascade.

HIV-related knowledge and risk behaviors of street youth in Belo Horizonte, Brazil. The Street Youth Study Group.

Individual interviews were conducted with 379 youth who work and/or live on the streets of a large Brazilian city to assess HIV-related knowledge, sources of information, risk behaviors, and prevention beliefs and strategies. Respondents demonstrated high levels of factual knowledge about HIV transmission (84% correct) coupled with high levels of misconceptions about casual transmission (53% correct) and intermediate levels of knowledge about prevention (64% correct). Only 54% of the respondents had heard about AIDS recently, and 37.5% said they talked to someone about AIDS. The most common sources of information about HIV/AIDS were the mass-media and friends. Over half the sample reported taking precautions to reduce their risk of HIV infection; however, the proportion of youth taking effective precautions was low. Among the 247 youth (65% of the sample) who had initiated sexual activity, lifetime condom use was reported by 18%, and condom use at last intercourse by 10%. Youth with higher levels of knowledge were more likely to report behavior changes to avoid HIV infection. These findings underscore the urgent need for prevention programs tailored to street youth in developing countries.

Lysosome-associated membrane protein-1-mediated targeting of the HIV-1 envelope protein to an endosomal/lysosomal compartment enhances its presentation to MHC class II-restricted T cells.

A subset of endogenously synthesized Ags can be processed for class II-restricted presentation, probably through multiple mechanisms. Processing of exogenous Ags for class II-restricted presentation appears to occur in unique endosomal processing compartments with lysosomal characteristics including the presence of the lysosomal membrane protein LAMP-1. Therefore, we attempted to enhance the efficiency of class II-restricted presentation of an endogenous Ag, the HIV-1 envelope (env) protein, by specifically targeting the Ag to class II processing compartments through the pathway followed by LAMP-1. Because the env protein associates tightly with CD4 shortly after synthesis, we first targeted the env protein using a chimeric CD4 protein consisting of the extracellular domain of CD4 and the transmembrane and cytoplasmic domains of LAMP-1. When co-expressed with this chimeric protein, the env protein was efficiently localized to lysosome-like compartments. Enhanced stimulation of env-specific CD4+ T cell clones by APC expressing the env protein and the CD4-LAMP-1 chimera was readily demonstrated in both cytotoxicity assays and proliferation assays. We also targeted the env protein directly as a chimeric protein consisting of the extracellular domain of the env protein and the transmembrane and cytoplasmic domains of LAMP-1. The proliferative response of env-specific CD4+ T cell clones to the env-LAMP-1 chimera was greatly enhanced compared with wild-type env protein, especially when limiting numbers of stimulator cells were used. The enhanced stimulatory capacity of APC expressing LAMP-1-targeted Ags has important implications for vaccine design.