Pre-exposure prophylaxis (PrEP) is traditionally prescribed by HIV specialist physicians. Given finite specialist resources, there is a need to scale up PrEP delivery by decentralizing services via ...other healthcare professionals. We aimed to assess the feasibility of delivering PrEP to men who have sex with men (MSM) through primary care physicians and sexual health clinic nurses. We piloted a multi-component, implementation and dissemination research program to increase provision of PrEP through primary care physicians and sexual health clinic nurses in Toronto, Canada. Community-based organizations (CBOs) provided prospective participants with information cards that contained links to an online module on engaging providers in a conversation about PrEP. In our patient-initiated continuing medical education (PICME) strategy, participants saw their family doctors and gave them the card, which also contained a link to a Continuing Medical Education module. In the nurse-led strategy, participants visited one of two participating clinics to obtain PrEP. We administered an optional online questionnaire to patients and providers at baseline and six months. CBOs distributed 3043 cards. At least 339 men accessed the online module and 196 completed baseline questionnaires. Most (55%) intended to visit nurses while 21% intended to consult their physicians. Among 45 men completing follow-up questionnaires at 6 months, 31% reported bringing cards to their physicians and obtaining PrEP through them; sexual health clinics delivered PrEP to 244 patients. Participants who went through the PICME approach reported no changes in relationships with their providers. Nurses showed fidelity to PrEP prescribing guidelines. Nurse-led PrEP and patient-initiated continuing medical education (PICME) for primary care physicians are feasible strategies to increase PrEP uptake. Nurse-led PrEP delivery was preferred by most patients.
Although HIV pre-exposure prophylaxis (PrEP) substantially diminishes the likelihood of HIV acquisition, poor adherence can decrease the HIV-protective benefits of PrEP. The present investigation ...sought to identify the extent to which alcohol consumption, substance use, and depression were linked to PrEP nonadherence among gay, bisexual, and other men-who-have-sex-with-men (gbMSM).
gbMSM (age ≥ 18, prescribed PrEP for ≥3 months) were recruited from two clinics in Toronto, Canada for an e-survey assessing demographics; PrEP nonadherence (4-day PrEP-focused ACTG assessment); hazardous and harmful alcohol use (AUDIT scores of 8-15 and 16+, respectively); moderate/high risk substance use (NIDA M-ASSIST scores > 4); depression (CESD-10 scores ≥10); and other PrEP-relevant factors. The primary outcome, PrEP nonadherence, entailed missing one or more PrEP doses over the past 4 days. A linear-by-linear test of association assessed whether increasing severity of alcohol use (i.e., based on AUDIT categories) was linked to a greater occurrence of PrEP nonadherence. Univariate logistic regression was employed to determine factors associated with PrEP nonadherence, and factors demonstrating univariate associations at the p < .10 significance level were included in a multivariate logistic regression model. Additive and interactive effects involving key significant factors were assessed through logistic regression to evaluate potential syndemic-focused associations.
A total of 141 gbMSM (Mean age = 37.9, white = 63.1%) completed the e-survey. Hazardous/harmful drinking (31.9%), moderate/high risk substance use (43.3%), and depression (23.7%) were common; and one in five participants (19.9%) reported PrEP nonadherence. Increasing alcohol use level was significantly associated with a greater likelihood of nonadherence (i.e., 15.6, 25.0, and 44.4% of low-risk, hazardous, and harmful drinkers reported nonadherence, respectively (χ
(1) = 4.79, p = .029)). Multivariate logistic regression demonstrated that harmful alcohol use (AOR = 6.72, 95%CI = 1.49-30.33, p = .013) and moderate/high risk cocaine use (AOR = 3.11, 95%CI = 1.01-9.59, p = .049) independently predicted nonadherence. Furthermore, an additive association emerged, wherein the likelihood of PrEP nonadherence was highest among those who were hazardous/harmful drinkers and moderate/high risk cocaine users (OR = 2.25, 95%CI = 1.19-4.25, p = .013). Depression was not associated with nonadherence.
Findings highlight the need to integrate alcohol- and substance-focused initiatives into PrEP care for gbMSM. Such initiatives, in turn, may help improve PrEP adherence and reduce the potential for HIV acquisition among this group.
Thiolation can convert molybdate (MoO4) into a series of thiomolybdates (MoSxO4-x) in the rumen, terminating in tetrathiomolybdate (MoS4), a potent antagonist of copper absorption and, if absorbed, ...donor of reactive sulphide in tissues. Systemic exposure to MoS4 increases trichloroacetic acid-insoluble copper (TCAI Cu) concentrations in the plasma of ruminants and induction of TCAI Cu in rats given MoO4 in drinking water would support the hypothesis that rats, like ruminants, can thiolate MoO4. Data on TCAI Cu are presented from two experiments involving MoO4 supplementation that had broader objectives. In experiment 1, plasma Cu concentrations (P Cu) tripled in female rats infected with Nippostrongylus brasiliensis after only 5 days exposure to drinking water containing 70 mg Mo L−1, due largely to an increase in TCAI Cu; activities of erythrocyte superoxide dismutase and plasma caeruloplasmin oxidase (CpOA) were unaffected. Exposure for 45–51 days did not raise P Cu further but TCA-soluble (TCAS) Cu concentrations increased temporarily 5 days post infection (dpi) and weakened the linear relationship between CpOA and TCAS Cu. In experiment 2, infected rats were given less MoO4 (10 mg Mo L−1), with or without iron (Fe, 300 mg L−1), for 67 days and killed 7 or 9 dpi. P Cu was again tripled by MoO4 but co-supplementation with Fe reduced TCAI Cu from 65 ± 8.9 to 36 ± 3.8 μmol L–l. Alone, Fe and MoO4 each reduced TCAS Cu in females and males when values were higher (7 and 9 dpi, respectively). Thiolation probably occurred in the large intestine but was inhibited by precipitation of sulphide as ferrous sulphide. Fe alone may have inhibited caeruloplasmin synthesis during the acute phase response to infection, which impacts thiomolybdate metabolism.
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► Robust RNA interference (RNAi) of some genes occurs in
Haemonchus contortus. ► Site of gene expression influences silencing. ► Can identify essential gene function in vivo by RNAi. ...► RNAi of H11 aminopeptidase gene results in decreased egg output, worm burden and aminopeptidase activity.
Gene silencing by RNA interference (RNAi) has been applied very successfully to
Caenorhabditis
elegans to study gene function but has proven less effective in parasitic nematodes. In the sheep gastrointestinal nematode
Haemonchus
contortus, previous studies demonstrated reproducible silencing of β-tubulin but not of other genes targeted. Here we aimed to examine whether the level of target transcript or site of gene expression influence susceptibility to RNAi by soaking. Target genes represented by a high number of expressed sequence tags (ESTs) in the
H.
contortus L3 stage were not reproducibly silenced. In contrast, four out of six genes putatively expressed in the intestine, excretory cell or amphids were consistently silenced by RNAi. This suggests that genes expressed in sites accessible to the environment are more likely to be susceptible to RNAi by soaking. Silenced genes included those encoding the highly protective gut aminopeptidase H11, secretory protein Hc-ASP-1, β-tubulin and homologues of aquaporin and RNA helicase. To determine whether RNAi silencing of H11 could mimic H11 vaccination in reducing worm and egg counts, we examined the in vivo effects of
H11 RNAi. This is the first, to our knowledge, in vivo study of RNAi in an animal parasitic nematode. RNAi of the
H11 gene in infective larvae prior to infection resulted in a 57% reduction in faecal egg count (FEC), 40% reduction in worm burden and 64% decrease in aminopeptidase activity compared with pre-soaking in control dsRNA. Thus, in this study we have established that RNAi is a valid and feasible approach to identify essential gene function. However, using current methods, this may be limited to genes expressed in accessible sites.
Low molybdate (MoO4) exposure via drinking water in mature rats infected with Nippostrongylus brasiliensis raised liver and plasma copper (Cu) concentrations. The possibility that anthelmintic ...effects were attributable to conversion of MoO4 to tetrathiomolybdate (MoS4) in a non-ruminant species was investigated by giving three groups of 18 immature rats drinking water containing 70 mg Mo l−1 as MoO4 (group A), 5 mg Mo l−1 as MoS4 (group B) or no supplement (group C), while receiving a commercial cubed diet. After 41 days, 12 rats from each group were inoculated subcutaneously with 2,000 L3-stage N. brasiliensis larvae. Subgroups were killed 7, 8 or 9 days post infection (dpi), when adult worms are normally expelled, and enzyme markers for the inflammatory response to infection were measured in plasma or liver. Male rats given MoS4 prior to infection grew more slowly than those given MoO4. Eight dpi, females given MoS4 had lost more bodyweight than those in group C, while those given MoO4 had gained weight. Mean worm counts at 7 dpi were 160, 65 and 250 ± 30.6 (SE), respectively, in groups C, A and B, and differed significantly from each other (P <0.05) but only rats given MoO4 remained infected 9 dpi (mean worm count 52 ± 16.4): Faecal egg counts followed a broadly similar pattern. Both Mo sources pre-empted increases in liver and duodenal superoxide dismutase activity, induced by infection 7 and 9 dpi, respectively, in group C and enlarged the femur: neither source prevented hypertrophy of the small intestine and a rise in serum mast cell protease concentration caused by infection. Since data for plasma Cu concentration and caeruloplasmin oxidase activity, reported separately, indicated MoO4 was thiolated in vivo, differences between Mo sources may be attributable to differences in the degree of thiolation, extent of thiomolybdate exposure and rates of thiomolybdate degradation at critical times in host or parasite development.
Adding a little molybdenum (Mo) as tetrathiomolybdate (MoS4; 5 mg Mo l−1) or more as molybdate (MoO4; 70 mg Mo l−1) to drinking water of immature rats, infected with Nippostrongylus brasiliensis, decreased liver superoxide dismutase activity (LSOD) 7 days after infection: both sources increased femur length (FL) but had opposite effects on worm count (WC). Cellular immunity may have been compromised by MoS4 but stimulated by MoO4 that had been partially thiolated by sulphide generated in the large intestine. Display omitted
Foxp3-expressing regulatory T (T reg) cells have been implicated in parasite-driven inhibition of host immunity during chronic infection. We addressed whether parasites can directly induce T reg ...cells. Foxp3 expression was stimulated in naive Foxp3⁻ T cells in mice infected with the intestinal helminth Heligmosomoides polygyrus. In vitro, parasite-secreted proteins (termed H. polygyrus excretory-secretory antigen HES) induced de novo Foxp3 expression in fluorescence-sorted Foxp3⁻ splenocytes from Foxp3-green fluorescent protein reporter mice. HES-induced T reg cells suppressed both in vitro effector cell proliferation and in vivo allergic airway inflammation. HES ligated the transforming growth factor (TGF) β receptor and promoted Smad2/3 phosphorylation. Foxp3 induction by HES was lost in dominant-negative TGF-βRII cells and was abolished by the TGF-β signaling inhibitor SB431542. This inhibitor also reduced worm burdens in H. polygyrus-infected mice. HES induced IL-17 in the presence of IL-6 but did not promote Th1 or Th2 development under any conditions. Importantly, antibody to mammalian TGF-β did not recognize HES, whereas antisera that inhibited HES did not affect TGF-β. Foxp3 was also induced by secreted products of Teladorsagia circumcincta, a related nematode which is widespread in ruminant animals. We have therefore identified a novel pathway through which helminth parasites may stimulate T reg cells, which is likely to be a key part of the parasite's immunological relationship with the host.
Based on the classic Radar Range-Performance Analysis from 1980, this practical volume extends that work to ensure applicability of radar equations to the design and analysis of modern radars. This ...unique book helps you identify what information on the radar and its environment is needed to predict detection range. Moreover, it provides equations and data to improve the accuracy of range calculations. You find detailed information on propagation effects, methods of range calculation in environments that include clutter, jamming and thermal noise, as well as loss factors that reduce radar performance. This invaluable book is supported with nearly 200 illustrations and over 430 equations.
Real‐time quaking‐induced conversion (RT‐QuIC) has been proposed as a sensitive diagnostic test for sporadic Creutzfeldt–Jakob disease; however, before this assay can be introduced into clinical ...practice, its reliability and reproducibility need to be demonstrated. Two international ring trials were undertaken in which a set of 25 cerebrospinal fluid samples were analyzed by a total of 11 different centers using a range of recombinant prion protein substrates and instrumentation. The results show almost complete concordance between the centers and demonstrate that RT‐QuIC is a suitably reliable and robust technique for clinical practice. Ann Neurol 2016;80:160–165
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