Patient perspectives on home-spirometry in interstitial lung disease: a qualitative co-designed study.

BACKGROUND: Opportunities for home-monitoring are increasing exponentially. Home- spirometry is reproducible and reliable in interstitial lung disease (ILD), yet patients' experiences are not reported. Given the morbidity and mortality associated with ILDs, maintaining health-related quality-of-life is vital. We report our findings from a codesigned, qualitative study capturing the perspectives and experiences of patients using home-spirometry in a UK regional ILD National Health Service England (NHSE) commissioned service. METHODS: Patients eligible for home-spirometry as routine clinical care, able to give consent and able to access a smart phone were invited to participate. In-depth, semistructured interviews were conducted at serial time points (baseline, 1, 3 and 6 months), recorded, transcribed and analysed thematically. RESULTS: We report on the experiences of 10 recruited patients (8 males; median age 66 years, range 50-82 years; 7 diagnosed with idiopathic pulmonary fibrosis, 3 other ILDs) who generally found spirometry convenient and easy to use, but their relationships with forced vital capacity results were complex. Main themes emerging were: (1) anticipated benefits-to identify change, trigger action and aid understanding of condition; (2) needs-clinical oversight and feedback, understanding of results, ownership, need for data and a need 'to know'; (3) emotional impact-worry, reassurance, ambivalence/conflicting feelings, reminder of health issues, indifference; (4) ease of home-spirometry-simplicity, convenience and (5) difficulties with home-spirometry-technical issues, technique, physical effort. CONCLUSION: Home-spirometry has many benefits, but in view of the potential risks to psychological well-being, must be considered on an individual basis. Informed consent and decision-making are essential and should be ongoing, acknowledging potential limitations as well as benefits. Healthcare support is vital.

Treatment of multiple synchronous canine mast cell tumours using intratumoural tigilanol tiglate.

Mast cell tumours (MCTs) are common canine skin neoplasia. While they generally occur as single tumours, multiple synchronous MCTs (msMCTs) of de novo/non-metastatic origin are reported in a proportion of the patient population. Where there is no evidence of metastasis or lymphatic spread, MCTs are effectively controlled by surgery and other local therapies. However, treatment of de novo msMCTs can be more challenging, especially when they occur in surgically difficult locations. Here, we report the use of tigilanol tiglate, a novel small molecule registered as a veterinary pharmaceutical for the local treatment of non-metastatic MCTs, in the treatment of patients with msMCTs presenting at three Australian specialist referral centres. We also present a meta-analysis of the literature to provide a better understanding of the prevalence of canine msMCTs. Notably, nine patients with a total of 32 MCTs were treated during the study. A complete response was recorded in 26 (81%) of the individual MCTs on Day 28 after a single tigilanol tiglate injection. Of the 6 initially non-responsive MCTs, one achieved a complete response after a further tigilanol tiglate treatment. A complete response was reported at 6 months in all 22 of the tumours that were evaluable and that had recorded a complete response at Day 84. For the literature meta-analysis, 22 studies were found with prevalence estimates of msMCTs ranging from 3 to 40%; when combined, these studies yielded 3,745 patients with a prevalence of 13% (95% CI 10; 16). Overall, the results demonstrate the utility of intratumoural tigilanol tiglate as an option for the treatment of multiple MCTs where multiple surgical resections would have been required.

Intratumoural Treatment of 18 Cytologically Diagnosed Canine High-Grade Mast Cell Tumours With Tigilanol Tiglate.

Canine high-grade mast cell tumours (HGMCT) are associated with a poor prognosis, are inherently more invasive, and have higher rates of local recurrence. The primary aim of this retrospective study was to assess the efficacy of intratumoural tigilanol tiglate (TT) as a local treatment option. Eighteen dogs with mast cell tumours (MCT) cytologically diagnosed by veterinary pathologists as either high-grade or suspected high-grade MCT were treated with TT. The TT dose was based on tumour volume (0.5 mg TT/cm3 tumour volume) and delivered intratumourally using a Luer lock syringe and a fanning technique to maximise distribution throughout the tumour mass. Efficacy was assessed on the presence/absence of a complete response (CR) to therapy at days 28 and 84 using response evaluation criteria in solid tumours (RECIST). For dogs not achieving a CR after 28 days, the protocol was repeated with a second intratumoural TT injection. Ten out of 18 dogs (56%) in this study achieved and maintained a CR to at least 84 days after their first or second treatment. Six patients were alive and available for evaluation at 2 years, three of those were recurrence free, and a further three patients were recurrence free following a second treatment cycle. Tigilanol tiglate shows efficacy for local treatment of HGMCT, with higher efficacy noted with a second injection if a CR was not achieved following the first treatment. In the event of treatment site recurrence (TSR), the tumour may be controlled with additional treatment cycles. Tigilanol tiglate provides an alternative local treatment approach to dogs with HGMCT that would either pose an unacceptable anaesthetic risk or the tumour location provides a challenge when attempting surgical excision.

Wound formation, wound size, and progression of wound healing after intratumoral treatment of mast cell tumors in dogs with tigilanol tiglate.

BACKGROUND: Tigilanol tiglate (TT) is a novel small molecule for intratumoral treatment of nonmetastatic mast cell tumors (MCTs) in dogs. In a randomized controlled clinical study, 75% of dogs that received a single TT treatment achieved complete resolution of the MCT by 28 days, with no recurrence in 93% of dogs at 84 days. Critical to TT's efficacy was the area of the wound (tissue deficit) after slough of the necrotic tumor relative to pretreatment tumor volume. OBJECTIVES: To analyze data collected during the previous study to (a) describe wounds after slough of treated MCTs and (b) identify determinants of wound area and speed of wound healing. METHODS: Wound presence, condition, and area were determined from clinical records of 117 dogs over 84 days after a single intratumoral TT treatment. RESULTS: Tumor slough occurred 3 to 14 days after treatment, exposing granulation tissue in the wound bed. Wound area after tumor slough in general was related to pretreatment tumor volume, with maximal recorded wound area fully evident in 89% of dogs by day 7. In dogs achieving complete tumor resolution, all wounds were left to heal by secondary intention. Bandaging and other wound management interventions only were required in 5 dogs. Time to healing (ie, full re-epithelialization of treatment site) depended on wound area and location on the body, with most wounds being fully healed between 28 and 42 days after treatment. CONCLUSIONS: Wound area and healing after slough of TT-treated tumors follow a consistent clinical pattern for most dogs.

Tigilanol Tiglate-Mediated Margins: A Comparison With Surgical Margins in Successful Treatment of Canine Mast Cell Tumours.

Tigilanol tiglate (TT) is a novel small molecule registered as a veterinary pharmaceutical for intratumoural treatment of canine mast cell tumours (MCTs). The drug has a multifactorial mode of action resulting in rapid destruction of the treated tumour by haemorrhagic necrosis and subsequent slough of the necrotic tumour to reveal a tissue deficit that is left to heal by second intention with minimal to no veterinary intervention. Here we introduce the concept of TT-mediated margins, the calculated margin of tissue loss analogous to surgically applied margins to help clinicians conceptualise tissue deficits formed following tumour destruction by TT relative to surgical excision. We used data from 51 dogs that were recurrence-free 12 months after a single administered TT dose into a single target MCT <10 cm3 in volume in a randomised, controlled clinical trial in the USA. We calculated TT-mediated margins based on length of the longest axis of (i) the tumour prior to treatment and (ii) the maximum tissue deficit formed 7-14 days after TT treatment. We compared these TT-mediated margins for each tumour to two surgical approaches to MCT excision in general practise: modified proportional margins (with 2 cm upper limit) and 3 cm fixed margins. For most dogs, TT-mediated margins were less than half the length of the margins calculated for the two surgical approaches in removing the same tumour. There was a trend for TT-mediated margins to increase with increasing tumour volume. Nonetheless, even for the larger tumours in this study (>2 cm3 volume), 50% of TT-mediated margins were less than half the length of the two surgical margins. Eighteen cases were lower limb MCTs, sites often surgically challenging in veterinary practise. On these lower limbs, TT-mediated margins were less than half the length of the corresponding proportional margins in 56% of cases and larger than proportional margins in only two cases. This study suggests that, in many cases, smaller and more targeted margins could be expected when treating MCTs <10 cm3 volume with TT compared with surgical excision. TT-mediated margins are a novel approach to conceptualise tissue deficits after intratumoural TT treatment.

Recurrence-free interval 12 months after local treatment of mast cell tumors in dogs using intratumoral injection of tigilanol tiglate.

BACKGROUND: Tigilanol tiglate (TT) is a novel small molecule approved by the European Medicines Agency for intratumoral treatment of mast cell tumors (MCTs) in dogs. In a randomized controlled clinical efficacy and safety study in the United States, 85 of 116 dogs that received a single TT injection achieved complete response (CR) of the treated MCT by day 28. OBJECTIVE: To evaluate the durability of the TT treatment response achieved at day 28 in the U.S. study by assessing MCT recurrence at the treatment site 6 and 12 months after TT administration. ANIMALS: Eighty-five dogs previously treated with TT. METHODS: Dogs that achieved CR at day 28 were assessed retrospectively for the presence or absence of MCT at the treatment site using records from clinical visits and telephone interviews with owners. Dogs unavailable at an assessment time were considered lost-to-follow-up and data for their last assessment used in the final analysis. RESULTS: By 12 months after TT treatment, 64 dogs remained evaluable, with 21 unavailable. Of evaluable patients, 57 (89%) remained tumor free at the treatment site and 7 (11%) had developed recurrence. All recurrences occurred within the first 6 months, predominantly (5/7, 71%) within the first 12 weeks. CONCLUSIONS AND CLINICAL IMPORTANCE: Tigilanol tiglate provided a durable long-term local response for the treatment of MCT in dogs.

High levels of engagement with testing for HIV and sexually transmissible infection among gay Asian men in Sydney and Melbourne: an observational study.

Background Gay and other men who have sex with men of Asian background (GAM) have been identified as a key population in efforts to eradicate HIV in New South Wales. The aims of the present study were to evaluate current levels of engagement with HIV and sexually transmissible infection (STI) testing services, assess knowledge of pre- and post-exposure prophylaxis and to identify factors associated with service engagement in this group. METHODS: A survey of 604 GAM residing in Sydney and Melbourne was undertaken. RESULTS: The data identified that a significant proportion of non-HIV-positive men (i.e. HIV-negative men and men whose HIV status was unknown) surveyed (n = 567; 93.9%) had engaged in frequent HIV testing and comprehensive STI testing in the 12 months prior to the survey (n = 180; 31.7%). There were significant differences (P < 0.05) in sexual practices at the bivariate level between those who reported frequent and comprehensive HIV/STI testing and those who did not. Those who tested regularly were substantially more sexually active, were more likely to have multiple partners (P = 0.001) and were more likely to engage in condomless anal intercourse with both casual (P < 0.001) and regular (P = 0.002) partners. Those who engaged with testing initiatives were more likely to discuss HIV status with both regular (P = 0.008) and casual (P < 0.001) partners, and identified more reasons to test than their counterparts (P < 0.001). The data also highlighted key service venues, with gay men most likely to have used public sexual health clinics (46.9%) as their most recent testing venue. CONCLUSIONS: The data demonstrate an association between high levels of male-to-male sexual activity and engagement in frequent and comprehensive HIV and STI testing. This likely derives from both self-perceived notions of risk and current reliance on established gay community organisations to convey information around testing. Increasing engagement with testing initiatives beyond GAM who self-identify as being at high HIV and STI risk will require the use of novel routes by which to disseminate this information.

Image-Based Artefact Removal in Laser Scanning Microscopy.

Recent developments in laser scanning microscopy have greatly extended its applicability in cancer imaging beyond the visualization of complex biology, and opened up the possibility of quantitative analysis of inherently dynamic biological processes. However, the physics of image acquisition intrinsically means that image quality is subject to a tradeoff between a number of imaging parameters, including resolution, signal-to-noise ratio, and acquisition speed. We address the problem of geometric distortion, in particular, jaggedness artefacts that are caused by the variable motion of the microscope laser, by using a combination of image processing techniques. Image restoration methods have already shown great potential for post-acquisition image analysis. The performance of our proposed image restoration technique was first quantitatively evaluated using phantom data with different textures, and then qualitatively assessed using in vivo biological imaging data. In both cases, the presented method, comprising a combination of image registration and filtering, is demonstrated to have substantial improvement over state-of-the-art microscopy acquisition methods.

Study Protocol: 6th National Survey of Australian Secondary Students and Adolescent Sexual Health, 2018.

Introduction: Since 1992 the Australian Government has funded a periodic national survey of HIV and Sexually Transmissible Infection (STI) knowledge and sexual risk behavior among secondary school students. Adolescents continue to be a priority population in public health efforts to reduce rates of STIs in Australia. The purpose of the survey is to inform progress on national strategic sexual health priorities. The results are used by federal and state/territory government agencies, youth-serving community organizations and health educators to improve knowledge, promote healthy sexual behaviors and target educational efforts aimed at communicating public health messages to young people. Materials and Equipment: The 6th survey entitled the "National Survey of Secondary Students and Adolescent Sexual Health" was conducted online in 2018 among 14-18 year olds living in Australia. The anonymous self-complete survey contained up to 286 items assessing three primary domains of knowledge, behaviors and education experiences. Factual knowledge measures covered HIV transmission and STI knowledge around transmission and prevention covering gonorrhea, Chlamydia, syphilis, hepatitis, herpes, and HPV. Behavioral measures examined perceived susceptibility, peer norms, protective behaviors, age of onset for various behaviors, reasons for not being sexually active yet, and/or sexual histories with additional detail on most recent sexual event. The 6th survey was completed by 8,400 Australian adolescents a represents a broad cross-section by age, gender, year in school, type of school (e.g., government, Catholic), and state/territory which closely matched census data on these strata. The one-of-a-kind survey instrument, grounded in public health theories, may prove valuable for public health researchers. Expected Impact of the Study on Public Health: Findings from the 6th National Survey of Secondary Students and Adolescent Sexual Health will contribute important insights into current knowledge, behaviors and educational experiences of young people. Results, similar to previous iterations of the survey, will inform public health practitioners, policymakers, educators, and advocates for the sexual health and well-being of young Australians. Results may assist sexual health services to align with broader public health goals articulated in the national HIV and STI strategies aimed to reduce the burden of disease and improve the quality of sexual lives of young Australians.

Segmentation of Vasculature From Fluorescently Labeled Endothelial Cells in Multi-Photon Microscopy Images.

Vasculature is known to be of key biological significance, especially in the study of tumors. As such, considerable effort has been focused on the automated segmentation of vasculature in medical and pre-clinical images. The majority of vascular segmentation methods focus on bloodpool labeling methods; however, particularly, in the study of tumors, it is of particular interest to be able to visualize both the perfused and the non-perfused vasculature. Imaging vasculature by highlighting the endothelium provides a way to separate the morphology of vasculature from the potentially confounding factor of perfusion. Here, we present a method for the segmentation of tumor vasculature in 3D fluorescence microscopic images using signals from the endothelial and surrounding cells. We show that our method can provide complete and semantically meaningful segmentations of complex vasculature using a supervoxel-Markov random field approach. We show that in terms of extracting meaningful segmentations of the vasculature, our method outperforms both state-of-the-art method, specific to these data, as well as more classical vasculature segmentation methods.

Perceptions of HIV cure research among people living with HIV in Australia.

Participation in HIV cure-related clinical trials that involve antiretroviral treatment (ART) interruption may pose substantial individual risks for people living with HIV (PLHIV) without any therapeutic benefit. As such, it is important that the views of PLHIV are considered in the design of HIV cure research trials. Examining the lived experience of PLHIV provides unique and valuable perspectives on the risks and benefits of HIV cure research. In this study, we interviewed 20 PLHIV in Australia about their knowledge and attitudes toward clinical HIV cure research and explored their views regarding participation in HIV cure clinical trials, including those that involve ART interruption. Data were analysed thematically, using both inductive and deductive coding techniques, to identity themes related to perceptions of HIV cure research and PLHIV's assessment of the possible risks and benefits of trial participation. Study findings revealed interviewees were willing to consider participation in HIV cure research for social reasons, most notably the opportunity to help others. Concerns raised about ART interruption related to the social and emotional impact of viral rebound, including fear of onward HIV transmission and anxiety about losing control. These findings reveal the ways in which PLHIV perspectives deepen our understanding of HIV cure research, moving beyond a purely clinical assessment of risks and benefits in order to consider the social context.

Comparing Australian gay and bisexual men with undiagnosed and recently diagnosed HIV infection to those in the National HIV Registry.

Background Gay and bisexual men (GBM) with recent HIV infection are a key population to inform HIV-prevention. The National HIV Registry (NHR) provides details about all individuals diagnosed with HIV, but it is unclear how. METHODS: Basic sociodemographic characteristics of GBM in the NHR who were diagnosed between 2010 and 2014 were compared with three samples of GBM: men with undiagnosed HIV infection from the Community-Based Study of Undiagnosed HIV and Testing (COUNT) study of HIV prevalence and undiagnosed infection that was conducted during 2013-14; men in the Australian Gay Community Periodic Surveys (GCPS) who were diagnosed with HIV between 2010 and 2014; and men in the HIV Seroconversion Study (SCS) who were also diagnosed in those years. RESULTS: The NHR identified 3629 men who reported male-to-male sex as the exposure risk for their diagnosis between 2010 and 2014. COUNT identified 19 (8.9% of all men who tested HIV positive) men as having undiagnosed HIV. In the GCPS sample, 185 (2.5%) reported being diagnosed with HIV in 2010-14. In total, 367 men in the SCS received their diagnosis during 2010-14. The mean age of men in the NHR (36.8 years) was similar to that in GCPS (36.3 years) and SCS (35.1 years), while undiagnosed men in COUNT were younger (32.6 years), with no other significant differences between the samples. CONCLUSIONS: The undiagnosed men were somewhat younger than diagnosed men. To achieve earlier diagnosis of new HIV infections, improved HIV testing frequency is needed among younger men.

Colorectal cancer liver metastases organoids retain characteristics of original tumor and acquire chemotherapy resistance.

BACKGROUND: Colorectal cancer (CRC) liver metastasis is highly unfavorable for patient outcome and is a leading cause of cancer-related death. Pre-clinical research of CRC liver metastasis predominately utilizes CRC cell lines grown in tissue culture. Here, we demonstrate that CRC liver metastases organoids derived from human specimens recapitulate some aspects of human disease. METHODS: Human CRC liver metastases pathological specimens were obtained following patient consent. Tumor disaggregates were plated and organoids were allowed to expand. CRC markers were identified by immunofluorescence. Stem cell genes were analysed by QPCR and flow cytometry. Response to drug therapy was quantified using time-lapse imaging and MATLAB analysis. RESULTS: Organoids showed global expression of the epithelial marker, EpCAM and the adenocarcinoma marker, CEA CAM1. Flow cytometry analysis demonstrated that organoids express the stem cell surface markers CD24 and CD44. Finally, we demonstrated that CRC liver metastases organoids acquire chemotherapy resistance and can be utilized as surrogates for drug testing. CONCLUSION: These data demonstrate that CRC liver metastases organoids recapitulate some aspects of human disease and may provide an invaluable resource for investigating novel drug therapies, chemotherapy resistance and mechanism of metastasis.

Acceptability and HIV Prevention Benefits of a Peer-Based Model of Rapid Point of Care HIV Testing for Australian Gay, Bisexual and Other Men Who Have Sex with Men.

Frequent HIV testing among gay, bisexual and other men who have sex with men (GBM) is a strategic priority for HIV prevention in Australia. To overcome barriers to testing in conventional clinical services, Australia recently introduced peer HIV rapid point of care (RPOC) testing services for GBM. This mixed methods evaluation describes client acceptability and HIV prevention benefits of a peer HIV testing model. Most aspects of the service model were overwhelmingly acceptable to clients. Two-thirds of survey participants reported preferring testing with peers rather than doctors or nurses and over half reported learning something new about reducing HIV risk. Focus group findings suggested peer-delivered HIV RPOC testing reduced stigma-related barriers to frequent testing and provided novel opportunities for GBM to openly discuss HIV prevention and sexual practices, enhancing their HIV risk-reduction knowledge. Analysis of survey data suggested knowledge transfer occurred particularly among younger and less gay community-attached GBM.

Extended outpatient chemoprophylaxis reduces venous thromboembolism after radical cystectomy.

PURPOSE: Venous thromboembolism (VTE), including deep venous thrombosis (DVT) and pulmonary embolism, is a common cause of morbidity and mortality after radical cystectomy. The purpose of our study was to evaluate the utility of extended outpatient chemoprophylaxis against VTE after radical cystectomy-with a focus on any reduction in the incidence of VTE, including DVT and pulmonary embolism. MATERIALS AND METHODS: Beginning in April 2013, we prospectively instituted a policy of extending inpatient VTE prophylaxis with subcutaneous heparin/enoxaparin for 30 days postoperatively. For this study, we reviewed the electronic medical records of all patients who underwent radical cystectomy at our institution from January 2012 through December 2015. The experimental group (n = 79) received extended outpatient chemoprophylaxis against VTE; the control group (n = 51) received no chemoprophylaxis after discharge. The primary outcome was the 90-day incidence of VTE. The secondary outcomes included the overall complication rate, the hemorrhagic complication rate, as well as the rate of readmission within 30 days of hospital discharge. RESULTS: The experimental group experienced a significantly lower rate of DVT (5.06%), assessed as of 90 days postoperatively, than the control group (17.6%): a relative risk reduction of 71.3% (P = 0.021). We found no significant differences in secondary outcomes between the 2 groups, including the overall complication rate (54.4% vs. 68.6%), the hemorrhagic complication rate (3.7% vs. 2.0%), and the readmission rate (21.5% vs. 29.4%). CONCLUSION: Extended outpatient chemoprophylaxis significantly reduced the incidence of VTE.

Perfused Three-dimensional Organotypic Culture of Human Cancer Cells for Therapeutic Evaluation.

Pharmaceutical research requires pre-clinical testing of new therapeutics using both in-vitro and in-vivo models. However, the species specificity of non-human in-vivo models and the inadequate recapitulation of physiological conditions in-vitro are intrinsic weaknesses. Here we show that perfusion is a vital factor for engineered human tissues to recapitulate key aspects of the tumour microenvironment. Organotypic culture and human tumour explants were allowed to grow long-term (14-35 days) and phenotypic features of perfused microtumours compared with those in the static culture. Differentiation status and therapeutic responses were significantly different under perfusion, indicating a distinct biological response of cultures grown under static conditions. Furthermore, heterogeneous co-culture of tumour and endothelial cells demonstrated selective cell-killing under therapeutic perfusion versus episodic delivery. We present a perfused 3D microtumour culture platform that sustains a more physiological tissue state and increased viability for long-term analyses. This system has the potential to tackle the disadvantages inherit of conventional pharmaceutical models and is suitable for precision medicine screening of tumour explants, particularly in hard-to-treat cancer types such as brain cancer which suffer from a lack of clinical samples.

CYP450 Enzymes Effect Oxygen-Dependent Reduction of Azide-Based Fluorogenic Dyes.

Azide-containing compounds have broad utility in organic synthesis and chemical biology. Their use as powerful tools for the labeling of biological systems in vitro has enabled insights into complex cellular functions. To date, fluorogenic azide-containing compounds have primarily been employed in the context of click chemistry and as sensitive functionalities for hydrogen sulfide detection. Here, we report an alternative use of this functionality: as fluorogenic probes for the detection of depleted oxygen levels (hypoxia). Oxygen is imperative to all life forms, and probes that enable quantification of oxygen tension are of high utility in many areas of biology. Here we demonstrate the ability of an azide-based dye to image hypoxia in a range of human cancer cell lines. We have found that cytochrome P450 enzymes are able to reduce these probes in an oxygen-dependent manner, while hydrogen sulfide does not play an important role in their reduction. These data indicate that the azide group is a new bioreductive functionality that can be employed in prodrugs and dyes. We have uncovered a novel mechanism for the cellular reduction of azides, which has implications for the use of click chemistry in hypoxia.

Methodological challenges in collecting social and behavioural data regarding the HIV epidemic among gay and other men who have sex with men in Australia.

BACKGROUND: Behavioural surveillance and research among gay and other men who have sex with men (GMSM) commonly relies on non-random recruitment approaches. Methodological challenges limit their ability to accurately represent the population of adult GMSM. We compared the social and behavioural profiles of GMSM recruited via venue-based, online, and respondent-driven sampling (RDS) and discussed their utility for behavioural surveillance. METHODS: Data from four studies were selected to reflect each recruitment method. We compared demographic characteristics and the prevalence of key indicators including sexual and HIV testing practices obtained from samples recruited through different methods, and population estimates from respondent-driven sampling partition analysis. RESULTS: Overall, the socio-demographic profile of GMSM was similar across samples, with some differences observed in age and sexual identification. Men recruited through time-location sampling appeared more connected to the gay community, reported a greater number of sexual partners, but engaged in less unprotected anal intercourse with regular (UAIR) or casual partners (UAIC). The RDS sample overestimated the proportion of HIV-positive men and appeared to recruit men with an overall higher number of sexual partners. A single-website survey recruited a sample with characteristics which differed considerably from the population estimates with regards to age, ethnically diversity and behaviour. Data acquired through time-location sampling underestimated the rates of UAIR and UAIC, while RDS and online sampling both generated samples that underestimated UAIR. Simulated composite samples combining recruits from time-location and multi-website online sampling may produce characteristics more consistent with the population estimates, particularly with regards to sexual practices. CONCLUSION: Respondent-driven sampling produced the sample that was most consistent to population estimates, but this methodology is complex and logistically demanding. Time-location and online recruitment are more cost-effective and easier to implement; using these approaches in combination may offer the potential to recruit a more representative sample of GMSM.

Plasmodium falciparum malaria elicits inflammatory responses that dysregulate placental amino acid transport.

Placental malaria (PM) can lead to poor neonatal outcomes, including low birthweight due to fetal growth restriction (FGR), especially when associated with local inflammation (intervillositis or IV). The pathogenesis of PM-associated FGR is largely unknown, but in idiopathic FGR, impaired transplacental amino acid transport, especially through the system A group of amino acid transporters, has been implicated. We hypothesized that PM-associated FGR could result from impairment of transplacental amino acid transport triggered by IV. In a cohort of Malawian women and their infants, the expression and activity of system A (measured by Na⁺-dependent ¹4C-MeAIB uptake) were reduced in PM, especially when associated with IV, compared to uninfected placentas. In an in vitro model of PM with IV, placental cells exposed to monocyte/infected erythrocytes conditioned medium showed decreased system A activity. Amino acid concentrations analyzed by reversed phase ultra performance liquid chromatography in paired maternal and cord plasmas revealed specific alterations of amino acid transport by PM, especially with IV. Overall, our data suggest that the fetoplacental unit responds to PM by altering its placental amino acid transport to maintain adequate fetal growth. However, IV more profoundly compromises placental amino acid transport function, leading to FGR. Our study offers the first pathogenetic explanation for FGR in PM.

Monocytes and macrophages in malaria: protection or pathology?

Recruitment and activation of monocytes and macrophages are essential for clearance of malaria infection, but these have also been associated with adverse clinical outcomes. In this review we discuss recent discoveries on how distinct molecular interactions between monocytes, macrophages, and malaria parasites may alter the balance between protection and pathology in malaria-infected individuals. The immunopathology of severe malaria often originates from excessive immune activation by parasites. The involvement of monocytes and macrophages in these events is highlighted, and priorities for future research to clarify the roles of these cells in malaria are proposed. Knowledge of the factors influencing the balance between protection and pathology can assist in the design of therapeutics aimed at modulating monocyte and macrophage functions to improve outcomes.