Does sexuality matter? A cross-sectional study of drug use, social injecting, and access to injection-specific care among men who inject drugs in Melbourne, Australia.

BACKGROUND: Gay, bisexual and other men who have sex with men (GBMSM) are overrepresented in cohorts of people who inject drugs. GBMSM's substance use is usually explored in the context of its contribution to sexual risk. We examined drug use practices, connectedness to other people who inject drugs, peer-to-peer injecting, and access to care among men who inject drugs in Melbourne, Australia. We aim to describe similarities and differences in these parameters for GBMSM and other men. METHODS: Data were drawn from a prospective cohort study of people who inject drugs conducted in Melbourne, Australia, since 2009. This cross-sectional study used data collected between 2016 and 2021. Descriptive statistics were used to assess differences between GBMSM and other men. RESULTS: Of 525 men who injected drugs over the study period, 48 (9%) identified as gay or bisexual, or reported sex with other men in the past 12 months. GBMSM and other men reported similar socio-demographics, drug practices (age of injecting initiation, most injected drug, peer-to-peer injecting, receptive syringe sharing) and access to injecting-specific care (drug treatment, source of needle-syringes). A significantly greater percentage of GBMSM reported past 12-month hepatitis C testing (69% vs. 52%, p = 0.028) and preferring methamphetamine (31% vs. 16%, p = 0.022). A higher percentage of GBMSM reported knowing > 50 other people who inject drugs (46% vs. 37%), but this difference was not statistically significant. Both groups primarily obtained injecting equipment from needle-syringe programs; a minority had accessed injecting-specific primary care. CONCLUSION: Men who injected drugs in this cohort and those who identified as GBMSM reported similar drug and health-seeking practices. The higher prevalence of methamphetamine injecting among GBMSM may warrant different harm reduction support for this group. Health promotion should utilise opportunities to connect men who inject drugs in Melbourne to injecting-specific primary health care.

Maternal systemic or cord blood inflammation is associated with birth anthropometry in a Tanzanian prospective cohort.

OBJECTIVES: HIV infection is associated with chronic systemic inflammation, with or without antiretroviral therapy. Consequences for foetal growth are not understood, particularly in settings where multiple maternal infections and malnutrition are common. The study was designed to examine maternal systemic circulating and umbilical cord blood cytokine concentrations in relation to birth anthropometry in a Tanzanian prospective cohort. METHODS: A 9-plex panel of maternal plasma cytokines in HIV-positive (n = 44) and HIV-negative (n = 70) mothers and the same cytokines in umbilical cord blood collected at delivery was assayed. Linear regression modelled associations between maternal or cord blood cytokines and birth anthropometry. RESULTS: Health indicators (haemoglobin, mid-upper-arm circumference, body mass index) in HIV-positive mothers without considerable immunosuppression did not differ from HIV-negative women. Despite this, HIV-exposed infants had lower birthweight and length. Subgroup analyses indicated that HIV management using HAART was associated with lower plasma TNF-α, as were longer durations of any antiretroviral therapy (≥2 months). Greater maternal plasma TNF-α was associated with earlier delivery (-1.7 weeks, P = 0.039) and lower birthweights (-287 g; P = 0.020), while greater umbilical cord TNF-α (-1.43 cm; P = 0.036) and IL-12p70 (-2.4 cm; P = 0.008) were associated with shorter birth length. Birthweight was inversely associated with cord IL-12p70 (-723 g; P = 0.001) and IFN-γ (-482 g, P = 0.007). Maternal cytokines during pregnancy did not correlate with umbilical cord cytokines at delivery. CONCLUSIONS: Systemic inflammation identified in maternal plasma or umbilical cord blood was associated with poorer birth anthropometrics in HIV-exposed and HIV-unexposed infants. Controlling maternal and/or foetal systemic inflammation may improve birth anthropometry.

Aldehyde reactivity with 2-thiobarbituric acid and TBARS in freeze-dried beef during accelerated storage.

When lipid oxidation is evaluated in freeze-dried beef, a yellow 450-nm-absorbing pigment develops during the 2-thiobarbituric acid (TBA) assay. TBA analysis and high performance liquid chromatography (HPLC) were applied to measure oxidative changes in salted freeze-dried beef patties (15% fat) initially during storage at 49°C. The TBA pink pigment (λ(max)=532 nm) was most pronounced in unstored salted freeze-dried beef, and yellow pigment (λ(max)=450 nm) predominated in stored samples. An in vitro study of TBA reactivity of different aldehydes, known to be secondary lipid oxidation products, showed that alkanals and alk-2-enals favored TBARS(450) formation, while alka-2,4-dienals favored TBARS(532). Values of TBARS(450) from 95°C TBA incubation were lower than those from 25°C incubation (P<0.05), indicating that the yellow chromophore from the aldehyde-TBA complex was less thermally stable than the pink pigment. 5-Hydroxymethyl-2-furfural, an aldehyde produced from Maillard reaction, also produced strong TBARS(450). Propional, butanal and 5-hydroxymethyl-2-furfural (HMF), were tentatively identified in freeze-dried beef during accelerated storage at 49°C, and have the potential to yield TBARS @450.