COVID-19 Vaccine Uptake and Its Impacts in a Cohort of Gay and Bisexual Men in Australia.

Successful use of biomedical forms of HIV risk-reduction may have predisposed many gay and bisexual men (GBM) to vaccination against COVID-19, which may, in turn, affect their sexual behavior. A total of 622 Australian GBM provided weekly data on COVID-19 vaccination history and sexual behaviour between 17 January 2021 and 22 June 2021. We identify factors associated with COVID-19 vaccination, and compare sexual behavior before and since vaccination. Mean age was 47.3 years (SD 14.0). At least one-dose vaccination coverage had reached 57.2%, and 61.3% reported that the majority of their friends intended to be vaccinated. Vaccinated men reported a mean of 1.11 (SD 2.10) weekly non-relationship sex partners before vaccination and 1.62 (SD 3.42) partners following vaccination. GBM demonstrated high confidence in COVID-19 vaccines. Their sexual activity increased following vaccination suggesting that greater sexual freedom may be a specific motivation for vaccine uptake among some men.

Habitual condom use across partner type and sexual position among younger gay and bisexual men: findings from New Zealand HIV behavioural surveillance 2006-2011.

OBJECTIVES: Our objectives were to investigate demographic and behavioural factors associated with condom use and to examine how habitual condom use was across partner types and sexual positions among younger men who have sex with men (YMSM), aged 16-29, surveyed in New Zealand. METHODS: We analysed the 2006-2011 national HIV behavioural surveillance data from YMSM who reported anal intercourse in four scenarios of partner type and sexual position: casual insertive, casual receptive, regular insertive and regular receptive. For each, respondents' condom use was classified as frequent (always/almost always) or otherwise, with associated factors identified with multivariate mixed-effect logistic regression. Habitual condom use across scenarios was examined using a latent variable technique that estimated the intraclass correlation coefficient (ICC). RESULTS: Frequent condom use was reported for 63.6% of 5153 scenarios reported from 2412 YMSM. Frequent use increased from boyfriend to fuckbuddy to casual partners. Infrequent use was associated with online recruitment, Pacific ethnicity, less education, HIV positivity, sex with women, having ≥20 sexual partners versus 1 and reporting insertive and receptive sexual positions. Frequent condom use was associated with having two to five sexual partners versus one and shorter regular partnerships. The ICC=0.865 indicated highly habitual patterns of use; habitual infrequent condom use was most prevalent with regular partners (53.3%) and habitual frequent condom use was most prevalent with casual partners (70.2%) and for either sexual position (50.5% and 49.1%). CONCLUSIONS: Habitual condom use among YMSM highlights the value of early, engaging and sustained condom promotion. Public health should provide better and more compelling condom education, training and promotion for YMSM.

HIV prevalence among men who have sex with men in New Zealand 1985-2009: 25 years of public health monitoring.

Annual population-based estimates of the number of men who have sex with men (MSM) with diagnosed HIV infection (HIV prevalence pool), and the proportion of all MSM this represents (HIV prevalence), have been insufficiently described over the long term. We investigated the dynamic effects of ongoing HIV diagnoses, lower mortality due to treatment and growth in the MSM population over time on these two epidemic indicators using national HIV/AIDS surveillance data in New Zealand, 1985-2009. The diagnosed HIV prevalence pool rose 79% between 1989 and 1999, and 137% between 1999 and 2009. Estimates of diagnosed HIV prevalence as a proportion of MSM were 0.2% of MSM in 1985, and were between 1.5% and 5.0% of MSM by 2009. New Zealand continues to have a relatively low-prevalence HIV epidemic among MSM; however, the number of MSM living with diagnosed infection is growing rapidly 25 years after HIV testing was introduced.

A pharmacokinetic evaluation of HIV protease inhibitors, cyclic ureas, in rats and dogs.

The pharmacokinetics of a series of novel cyclic, non-peptide inhibitors of HIV protease were studied in rats or dogs after intravenous and oral administration. Six symmetrically substituted cyclic urea compounds (XK234, XM311, XM320, XM321, XM323, and XM412), which effectively inhibited HIV virus replication, with IC90 values of 0.03-1.0 microM (0.017-0.76 microgram mL-1), were evaluated. Plasma concentrations were measured in rats and dogs using specific and sensitive HPLC methods. In rats, the maximum plasma concentrations of 0.21-1.88 micrograms mL-1 were detected within 1 h of oral administration of 10 mg kg-1 of the compounds. The elimination half-lives ranged from 1.25 to 3.3 h in rats and the absolute oral bioavailability ranged from 18 to 100%. In dogs, the maximum plasma concentration and absolute oral bioavailability were 4.37 micrograms mL-1 and 48%, 1.07 micrograms mL-1 and 16%, and 1.48 mg ML-1 and 38% for XK234, XM311, and XM323, respectively. The data demonstrated that the maximum plasma concentrations of these cyclic ureas were several times higher than the IC90 for inhibition of viral replication after single doses of 10 mg kg-1 in rats and dogs. With this combination of high potency against virus replication and good oral bioavailability, these cyclic ureas represent a new class of compounds that are suitable for development as therapeutic agents for the treatment of HIV-associated diseases.

Pharmacokinetics of HIV protease inhibitor DMP 323 in rats and dogs.

DMP 323 is a symmetrically substituted cyclic urea compound with demonstrated activity against human immunodeficiency virus (HIV) in vitro. DMP 323 has been measured in rat and dog plasma via liquid-liquid extraction and HPLC. The limit of quantitation is 10 ng/ml using 0.5 ml plasma. Following an intravenous dose of 5 mg/kg to rats, DMP 323 exhibited an apparent volume of distribution at steady-state of 6.36 liters/kg and clearance of 7.12 liters/hr/kg. The same dose administered intravenously to dogs resulted in apparent volume of distribution at steady-state and clearance values of 2.28 liters/kg and 1.48 liters/hr/kg, respectively. Elimination half-lives were 0.95 hr in rats and 1.80 hr in dogs. DMP 323 was rapidly absorbed from oral solution doses in rats (3, 5, and 10 mg/kg) and dogs (5 and 10 mg/kg), achieving maximum plasma concentrations in 1 hr or less in both species. Absolute bioavailability of DMP 323 from oral doses ranged from 15 to 27% in rats and from 37 to 38% in dogs. Pharmacokinetics were unchanged in rats and dogs over 8-day t.i.d. and 5-day b.i.d. multiple oral dose regimens, respectively. Oral doses administered to fed animals resulted in lower plasma concentrations of DMP 323 than the same doses administered to fasted animals. Because of its in vitro high potency and acceptable pharmacokinetics, DMP 323 seems to be a worthy candidate for further study in the effort to develop an inhibitor of HIV protease for use in the therapy of AIDS.

Determination of a novel sigma receptor antagonist, DuP 734, in rat plasma by reversed-phase high-performance liquid chromatography with ultraviolet detection.

A selective high-performance liquid chromatographic (HPLC) assay for a sigma receptor antagonist, DuP 734 (I), in rat plasma has been developed. Compound I and internal standard, XC031 (I.S.), were first extracted from plasma into an ethyl acetate-toluene mixture (3:7, v/v) and then back-extracted into freshly prepared phosphoric acid (0.03 M). Separation of I and I.S. with no interference from endogenous substances was achieved on a reversed-phase octyl column and detection was by UV at 229 nm. The mobile phase consisted of acetonitrile-glacial acetic acid-triethylamine-0.05 M ammonium acetate (670:4:2:2000, v/v). Using 0.5 ml of rat plasma for extraction, the limit of quantitation was 43 ng/ml and the assay was linear from 43 to 8536 ng/ml. The intra- and inter-day coefficients of variation ranged from 0.7 to 3.0%, and from 1.4 to 14.5%, respectively, over the entire concentration range. The accuracy was within 16.1% of the spiked concentrations. I was stable in frozen plasma at -20 degrees C for at least 68 days.

Visual evoked potentials to light flash in cats: is a frontal sinus reference electrode truly indifferent?

In flaxedilized cats, visual cortex evoked potentials (VEPs) to an intensity series of brief light flashes were recorded differentially using either a screw over frontal sinus or an insect pin in neck muscle as the reference electrode. At the same time EPs from the cornea (the ERG) and frontal sinus were recorded differentially against the neck muscle electrode. The EP recorded from the frontal sinus screw was a miniature of the ERG recorded from the cornea, with the same latencies and shape as the ERG but only 10-30% of its amplitude. At a fast presentation rate (1/sec) the amplitude of the ERG, and consequently the frontal sinus potential, decreased with increasing intensity of light flash, whereas at a slow presentation rate (1/3 or 1/5 sec) the ERG and frontal sinus potential increased in response to all but the highest intensities. The location of the reference electrode and the rate of light flash presentation had the following effects on visual cortex EP amplitudes. A frontal sinus reference increased the amplitudes of early components (less than 100 msec) of the VEP. Also, VEP amplitudes as a function of flash intensity yielded slopes which tended to be positive at a slow presentation rate and negative at a fast presentation rate. This effect is in accord with the rate dependent slopes of the frontal sinus potential.

Leishmaniasis in The Gambia. 2. A study of possible vectors and animal reservoirs, with the first report of a case of canine leishmaniasis in The Gambia.

Following the detection of two cases of leishmaniasis in The Gambia, the possible vectors and animal reservoirs were studied. A total of 5, 158 phlebotomine sandflies, in 20 species and subspecies were captured, including 98 males and 61 females of Phlebotomus duboscqi. This species is a vector of cutaneous leishmaniasis in Senegal and must be suspected as a vector in The Gambia; it was captured close to the dwellings of both patients and from rodent burrows, including those of Mastomys erythroleucus, a known reservoir of cutaneous leishmaniasis in Senegal. We report the first finding in The Gambia of visceral leishmaniasis in a dog captured near the house of the patient with visceral leishmaniasis. This strongly suggests that dogs could be a reservoir of this infection in this area. The vector was not determined.

Simulation analysis of platelet production and inventory management.

To maximize the availability of platelet concentrates (PC) and minimize their outdate, competing criteria, a computer simulation model of platelet production and distribution was developed. Based on 2 years of actual platelet orders placed with a regional blood center, the simulation program generated daily platelet orders, and also calculated mean demand and standard deviation of demand for each day of the week. The number of PC to be produced on a given day was calculated from: PC to be produced = (mean demand for that day of the week) + Tx (standard deviation of demand for that day of the week)-(PC in inventory on the given day), where T is a selected multiple of the standard deviation. As T increases, availability is maximized, but outdating is expected to increase. Conversely, lower T is associated with less availability, but lower outdate. At the simulated platelet demand level (about 735 PC per week), with 3-day platelet storage life, 99% availability is associated with 1% outdate and distribution of PC of less than 1 day average age. 100% availability, with no outdate is predicted for a 5-day storage life, with no further improvement in logistics with 7-day storage life, at this level of demand. Although logistics of platelet production and distribution vary from center to center, the simulation analysis is generally applicable, and a formal plan has the great advantage of predictive, rather than reactive, platelet production.

Post-soldering of nonprecious alloys.

A repeatable post-soldering technique for a nonprecious alloy has been described. With proper metal design, nonprecious alloy crowns can be soldered in a standard vacuum porcelain furnace. Scanning electron micrographs and EDXA confirm that a good union has taken place between the gold solder and nickel alloy.