Publications by authors named "Holtz T"

Body fossils set limits on feasible reconstructions of functional capacity and behavior in theropod dinosaurs, but do not document in-life behaviors. In contrast, trace fossils such as footprints preserve in-life behaviors that can potentially test and enhance existing reconstructions. Here, we demonstrate how theropod trackways can be used as indirect evidence of pre-avian aerial behavior, expanding the approaches available to study vertebrate flight origins.

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Recent years have seen increasing scientific interest in whether neuron counts can act as correlates of diverse biological phenomena. Lately, Herculano-Houzel (2023) argued that fossil endocasts and comparative neurological data from extant sauropsids allow to reconstruct telencephalic neuron counts in Mesozoic dinosaurs and pterosaurs, which might act as proxies for behaviors and life history traits in these animals. According to this analysis, large theropods such as Tyrannosaurus rex were long-lived, exceptionally intelligent animals equipped with "macaque- or baboon-like cognition", whereas sauropods and most ornithischian dinosaurs would have displayed significantly smaller brains and an ectothermic physiology.

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Human leukocyte antigen (HLA) alleles have been linked to HIV disease progression and attributed to differences in cytotoxic T lymphocyte (CTL) epitope representation. These findings are largely based on treatment-naive individuals of European and African ancestry. We assessed HLA associations with HIV-1 outcomes in 1,318 individuals from Thailand and found HLA-B∗46:01 (B∗46) associated with accelerated disease in three independent cohorts.

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In 2019, approximately 1.2 M persons were living with HIV and an estimated 34,800 new HIV infections occurred in the United States (U.S.

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Purpose: To examine how recent sex work is identified and the HIV risk factors and service needs among Thai cisgender men who have sex with men (MSM) and transgender women (TGW) who exchange sex.

Methods: MSM and TGW in Bangkok and Pattaya who exchanged sex in the last year (n = 890) were recruited through social media, outreach, and word-of-mouth. Recent sex exchange was based on the primary question, "In the last 30 days, have you sold or traded sex"; secondary questions (regarding income source and client encounters) were also investigated.

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In trials of oral HIV pre-exposure prophylaxis (PrEP), multiple approaches have been used to measure adherence, including self-report, pill counts, electronic dose monitoring devices, and biological measures such as drug levels in plasma, peripheral blood mononuclear cells, hair, and/or dried blood spots. No one of these measures is ideal and each has strengths and weaknesses. However, accurate estimates of adherence to oral PrEP are important as drug efficacy is closely tied to adherence, and secondary analyses of trial data within identified adherent/non-adherent subgroups may yield important insights into real-world drug effectiveness.

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Background: Safe and effective long-acting injectable agents for preexposure prophylaxis (PrEP) for human immunodeficiency virus (HIV) infection are needed to increase the options for preventing HIV infection.

Methods: We conducted a randomized, double-blind, double-dummy, noninferiority trial to compare long-acting injectable cabotegravir (CAB-LA, an integrase strand-transfer inhibitor [INSTI]) at a dose of 600 mg, given intramuscularly every 8 weeks, with daily oral tenofovir disoproxil fumarate-emtricitabine (TDF-FTC) for the prevention of HIV infection in at-risk cisgender men who have sex with men (MSM) and in at-risk transgender women who have sex with men. Participants were randomly assigned (1:1) to receive one of the two regimens and were followed for 153 weeks.

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Introduction: Data on HIV antiretroviral therapy (ART) initiation among key-affected populations will support reaching the UNAIDS goal to end AIDS by 2030.

Methods: We assessed ART initiation among HIV-positive participants of the Bangkok Men Who Have Sex with Men (MSM) Cohort Study, which enrolled sexually experienced MSM aged ≥ 18 years and included visits every four months for a period of 3-5 years, from 2006-2016. At each visit, participants had HIV testing and completed computer-assisted self-interviewing on demographics and HIV risk behaviors.

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Tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC) are used for HIV treatment and prevention. Previously, we found that topical rectal tenofovir gel caused immunological changes in the mucosa. Here, we assess the effect of oral TDF/FTC in three HIV pre-exposure prophylaxis trials, two with gastrointestinal and one with cervicovaginal biopsies.

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Objectives: We assessed HIV-1 infection among men who have sex with men (MSM) attending Silom Community Clinic (SCC) in Bangkok, Thailand from 2005 to 2018. Since 2014, Thailand increased implementation of HIV prevention strategies including pre-exposure prophylaxis and Treatment as Prevention.

Methods: MSM attending SCC were tested for HIV using rapid tests.

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Spatiotemporal analyses can support Human Immuno-deficiency Virus (HIV) prevention programmes by identifying locations of at-risk populations in space and time, and their proximity to HIV testing and prevention services. We assessed residential proximity to HIV testing venues for Men who have Sex with Men (MSM) and Transgender Women (TGW) attending Voluntary Counselling and Testing (VCT) at a large urban MSM clinic in Bangkok, Thailand in the period 2005-2015. We mapped clientprovided spatial data and HIV testing venues, calculating distance from residence to venues for VCT clients between i) September 2005-December 2009; ii) January 2010-September 2013; and iii) October 2013-May 2015.

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Limb length, cursoriality and speed have long been areas of significant interest in theropod paleobiology, since locomotory capacity, especially running ability, is critical in the pursuit of prey and to avoid becoming prey. The impact of allometry on running ability, and the limiting effect of large body size, are aspects that are traditionally overlooked. Since several different non-avian theropod lineages have each independently evolved body sizes greater than any known terrestrial carnivorous mammal, ~1000kg or more, the effect that such large mass has on movement ability and energetics is an area with significant implications for Mesozoic paleoecology.

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Background: Pre-exposure prophylaxis (PrEP) is highly effective in the prevention of HIV acquisition, particularly for men who have sex with men (MSM). Questions remain on the benefits of PrEP and implementation strategies for those at occupational risk of HIV acquisition in sex work, as well as on methods to support adherence among young people who initiate PrEP.

Objective: The Combination Prevention Effectiveness study for young cisgender MSM and transgender women (TGW) aims to assess the effectiveness and cost-effectiveness of a combination intervention among HIV-uninfected young MSM and TGW engaged in sex work in Thailand.

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Persons with multidrug-resistant tuberculosis (MDR-TB) have a disease resulting from a strain of tuberculosis (TB) that does not respond to at least isoniazid and rifampicin, the two most effective anti-TB drugs. MDR-TB is always treated with multiple antimicrobial agents. Our data consist of individual patient data from 31 international observational studies with varying prescription practices, access to medications, and distributions of antibiotic resistance.

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Article Synopsis
  • The study examined the effectiveness of urine lipoarabinomannan (LAM) testing in hospitalized TB and HIV co-infected patients with low CD4 counts, focusing on those who are sputum smear-negative and often go untreated in TB endemic areas.
  • Out of 156 analyzed patients, LAM was found to be 55.6% sensitive, and higher rates of urine LAM positivity were linked to lower CD4 counts, suggesting its potential role in diagnosing TB quickly in severely ill patients.
  • The findings indicate that most LAM-positive patients received multiple antibiotics, highlighting an opportunity to reduce unnecessary antibiotic use through better TB diagnosis with LAM testing.
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Background: We identified correlates of sex-related pre-exposure prophylaxis (PrEP) adherence in HPTN067/ADAPT, a phase 2, open-label feasibility study of daily and nondaily regimens of emtricitabine/tenofovir disoproxil fumarate (FTC/TDF)-based PrEP, among Thai men who have sex with men (MSM), and transgender women (TGW), Bangkok.

Methods: Participants were randomly assigned to one of three self-administered dosing regimens for 24 weeks: daily, time-driven, or event-driven. Demographic and behavioral information was obtained at screening.

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Background: The HIV Prevention Trials Network (HPTN) 067/Alternative Dosing to Augment PrEP Pill Taking (ADAPT) Study evaluated the feasibility of daily and nondaily human immunodeficiency virus (HIV) preexposure prophylaxis (PrEP) regimens among high-risk populations, including men who have sex with men (MSM) and transgender women, in Bangkok, Thailand and Harlem, New York. We used a mathematical model to predict the efficacy and effectiveness of different dosing regimens.

Methods: An individual-based mathematical model was used to simulate annual HIV incidence among MSM cohorts.

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Background: The effectiveness of oral emtricitabine (FTC)/tenofovir (TFV) disoproxil fumarate-based HIV pre-exposure prophylaxis (PrEP) depends on adherence. Pharmacologic measures help interpret patterns and predictors of PrEP adherence.

Setting: We analyzed data from the subsample of men who have sex with men enrolled in HPTN 067/ADAPT in Bangkok, Thailand, and Harlem, NY, U.

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Background: As daily oral preexposure prophylaxis (PrEP) becomes standard for HIV prevention, routine use of PrEP is likely to increase within clinical trials of novel preventive agents. We describe the prevalence and characteristics of participants reporting nonstudy oral PrEP use within Microbicide Trials Network-017 (MTN-017), a phase 2 trial of a rectal microbicide.

Setting And Methods: One hundred ninety-five HIV-uninfected men who have sex with men and transgender women were enrolled and followed in MTN-017 across 8 sites in the United States, Thailand, South Africa, and Peru from 2013 to 2015.

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Since September 2015, the World Health Organization has recommended antiretroviral therapy (ART) for all persons with human immunodeficiency virus (HIV) infection, regardless of clinical stage or CD4 count (1). This Treat All policy was based on evidence that ART initiation early in HIV infection as opposed to waiting for the CD4 count to decline to certain levels (e.g.

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Objective: We evaluated the relationship between 2 types of social relationships, ie, (1) external support for use of HIV pre-exposure prophylaxis (PrEP) and related study supplies and (2) participants' disclosure of PrEP use and condom use and HIV PrEP adherence among daily-dosing regimen participants in HIV Prevention Trials Network (HPTN) 067, an open-label trial of oral tenofovir (TFV) disoproxil fumarate (TDF) 300 mg/emtricitabine (FTC) 200 mg.

Methods: Using HPTN 067 survey data, we developed scales examining (1) Low Perceived External Support for PrEP: low perceived support by others for PrEP use or perceived negative reactions to the pill case (scoring ranges from 0 to 2) and (2) Participant-Staff Disclosure Challenges Scale, which identifies challenges to sharing nonuse of PrEP or condoms to study staff (scoring ranges from 0 to 4); these scales are the primary independent variables. Adherence, the dependent variable, was determined using log-transformed plasma TFV concentrations.

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The HPTN 067/ADAPT Study evaluated the feasibility, acceptability, patterns of adherence and coverage for three randomly assigned oral FTC/TDF pre-exposure prophylaxis (PrEP) dosing regimens to prevent HIV infection. Using qualitative methods, we explored facilitators and barriers among a subset of men who have sex with men (MSM) participants in Bangkok, Thailand. Between August 2013 and March 2014, 32 HPTN 067/ADAPT participants joined in 6 focus group discussions, and 6 attended key informant interviews.

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Background: Human immunodeficiency virus (HIV)-infected persons are at a higher risk of severe influenza. Although we have shown that a standard-dose intradermal influenza vaccine versus a standard-dose intramuscular influenza vaccine does not result in differences in hemagglutination-inhibition titers in this population, a comprehensive examination of cell-mediated immune responses remains lacking.

Methods: Serological, antigen-specific B-cell, and interleukin 2-, interferon γ-, and tumor necrosis factor α-secreting T-cell responses were assessed in 79 HIV-infected men and 79 HIV-uninfected men.

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