HIV risk behaviour and HIV testing of psychiatric patients in Melbourne

OBJECTIVES: Patients with chronic mental illnesses constitute an important risk group for HIV infection overseas. This study aimed to determine the prevalence of risk behaviours associated with HIV transmission and factors associated with HIV testing in psychiatric patients in Melbourne. METHODS: Inpatients and outpatients completed an interviewer-administered questionnaire which covered demographics, psychiatric diagnosis, risk behaviour, and HIV education and testing. RESULTS: Of 145 participants, 60% were male and 55.2% had schizophrenia. Injecting drug use (IDU) was reported by 15.9%, a figure approximately 10 times that found in other population surveys. Most patients reported sex in the last decade and over 20% had multiple sexual partners in the last year. Of males, 12.6% reported sex with another male (9.2% anal sex); 19.0% of females reported sex with a bisexual male. Nearly half of the males reported sex with a prostitute, 2.5 times that in a population sample. Only 15.9% reported ever having someone talk to them specifically about HIV and its transmission, although one-third had been tested for HIV. In multivariate analysis, male-male sex, paying for sex, and IDU were associated with HIV testing, but those whose primary language was not English were less likely to be tested. Those who had received HIV education were more likely to have used a condom last time they had sex (OR 4.52, 95%CI 1.49-14.0). CONCLUSIONS: This study provides evidence that those with serious mental illness in Victoria have higher rates of participation in risk behaviour for HIV infection than those in the general community. Attention to HIV education and prevention in this group has been inappropriately scant; strategies to encourage safer behaviour are urgently needed.     

Overexpression of leukotriene C4 synthase in bronchial biopsies from patients with aspirin-intolerant asthma

Aspirin causes bronchoconstriction in aspirin-intolerant asthma (AIA) patients by triggering cysteinyl-leukotriene (cys-LT) production, probably by removing PGE2-dependent inhibition. To investigate why aspirin does not cause bronchoconstriction in all individuals, we immunostained enzymes of the leukotriene and prostanoid pathways in bronchial biopsies from AIA patients, aspirin-tolerant asthma (ATA) patients, and normal (N) subjects. Counts of cells expressing the terminal enzyme for cys-LT synthesis, LTC4 synthase, were fivefold higher in AIA biopsies (11.5+/-2.2 cells/mm2, n = 10) than in ATA biopsies (2.2+/-0.7, n = 10; P = 0. 0006) and 18-fold higher than in N biopsies (0.6+/-0.4, n = 9; P = 0. 0002). Immunostaining for 5-lipoxygenase, its activating protein (FLAP), LTA4 hydrolase, cyclooxygenase (COX)-1, and COX-2 did not differ. Enhanced baseline cys-LT levels in bronchoalveolar lavage (BAL) fluid of AIA patients correlated uniquely with bronchial counts of LTC4 synthase+ cells (rho = 0.83, P = 0.01). Lysine-aspirin challenge released additional cys-LTs into BAL fluid in AIA patients (200+/-120 pg/ml, n = 8) but not in ATA patients (0. 7+/-5.1, n = 5; P = 0.007). Bronchial responsiveness to lysine-aspirin correlated exclusively with LTC4 synthase+ cell counts (rho = -0.63, P = 0.049, n = 10). Aspirin may remove PGE2-dependent suppression in all subjects, but only in AIA patients does increased bronchial expression of LTC4 synthase allow marked overproduction of cys-LTs leading to bronchoconstriction.     

Frequency of ApoB and ApoE gene mutations as causes of hypobetalipoproteinemia in the framingham offspring population

Rearranged immunoglobulin variable genes are extensively mutated after stimulation of B lymphocytes by antigen. Mutations are likely generated by an error-prone DNA polymerase, and the mismatch repair pathway may process the mispairs. To examine the role of the MSH2 mismatch repair protein in hypermutation, Msh2-/- mice were immunized with oxazolone, and B cells were analyzed for mutation in their VkappaOx1 light chain genes. The frequency of mutation in the repair-deficient mice was similar to that in Msh2+/+ mice, showing that MSH2-dependent mismatch repair does not cause hypermutation. However, there was a striking bias for mutations to occur at germline G and C nucleotides. The results suggest that the hypermutation pathway frequently mutates G.C pairs, and a MSH2-dependent pathway preferentially corrects mismatches at G and C.     

Comparative analyses of seven technologies to facilitate the integration of fluctuating renewable energy sources

An analysis of seven different technologies is presented. The technologies integrate fluctuating renewable energy sources (RES) such as wind power production into the electricity supply, and the Danish energy system is used as a case. Comprehensive hour-by-hour energy system analyses are conducted of a complete system meeting electricity, heat and transport demands, and including RES, power plants, and combined heat and power production (CHP) for district heating and transport technologies. In conclusion, the most fuel-efficient and least-cost technologies are identified through energy system and feasibility analyses. Large-scale heat pumps prove to be especially promising as they efficiently reduce the production of excess electricity. Flexible electricity demand and electric boilers are low-cost solutions, but their improvement of fuel efficiency is rather limited. Battery electric vehicles constitute the most promising transport integration technology compared with hydrogen fuel cell vehicles (HFCVs). The costs of integrating RES with electrolysers for HFCVs, CHP and micro fuel cell CHP are reduced significantly with more than 50% of RES.     

The evolution and oxidation of carbides in an Alloy 601 exposed to long term high temperature corrosion conditions

Inconel 601 alloy has been studied after 2 years exposure in a commercial methanol plant. Carbon penetration leads to precipitation of nanometer-scale M₂₃C₆ and coarser M₇Cr₃, tens of microns below and within several microns of the alloy surface respectively, as predicted by thermodynamic calculations. Previously unreported M₃C_2−x precipitates form between the M₂₃C₆ and M₇C₃ in the C-concentration gradient and sometimes outcrop the surface. Carbides are Cr-rich, the smallest may contain Fe, orientated with respect to the matrix and oxidize when exposed to the corrosion product and synthesis gas. The Cr₂O₃ formed is not optimal for protection from carbon ingress.     

Microstructural studies of self-supported (1.5–10 μm) Pd/23 wt%Ag hydrogen separation membranes subjected to different heat treatments

The microstructure of self-supported 1.5–10-μm thick Pd/23 wt%Ag membranes grown by magnetron sputtering have been studied after heat treatment and hydrogen permeation tests using electron microscopy and synchrotron X-ray diffraction. After hydrogen flux stabilization and permeance measurements at 300 °C, the membranes were annealed in air at 300 °C or in N₂/Ar at 300/400/450 °C for 4 days and then tested for hydrogen permeation. The permeation results show that changes in permeability depend on the treatment atmosphere and temperature, as well as membrane thickness. Air treatment at ~300 °C generally induced a positive effect on permeation in the thickness range of 1.5–10 μm. Significant microstructural changes, including grain growth, strain relief, void formation, and growth of nodules occurred in the membranes. The changes in microstructure are more severe for the thinner membranes, and may be attributed mainly to the oxidation processes at or near the surface. For samples annealed in N₂/Ar, enhanced permeation was only obtained with treatment at ~450 °C for 5 and 10 μm. The changes in the microstructure generally increased with heat-treatment temperature, and decreased with membrane's thickness. The membrane with enhanced permeation was accompanied by significant grain growth, strain relief, and surface roughening. For all the membranes, the relative changes in the microstructure were substantially more prominent on the permeate surface than on the feed surface. Details of the analysis are presented and discussed.