Pooled Pharyngeal, Rectal, and Urine Specimens for the Point-of-Care Detection of Chlamydia trachomatis and Neisseria gonorrhoeae by Lay Providers in Key Population-Led Health Services in Thailand

Routine testing for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) in people with heightened risk is lacking in Thailand. This study aimed to assess the performance of the Cepheid Xpert CT/NG assay, conducted by key population (KP) lay providers, for CT and NG detection on single-site and pooled specimens from the pharynx, rectum, and urine. Between August and October 2019, 188 men who have sex with men and 11 transgender women were enrolled. Participants collected urine specimens while trained KP lay providers obtained pharyngeal and rectal swabs. Compared to single-site testing with the Abbott RealTime CT/NG assay by medical technologists, the Xpert assay missed one pharyngeal NG infection out of 199 single-site specimens, giving a 93.3% sensitivity for pharyngeal NG and one missed pharyngeal NG infection out of fifty pooled specimens, giving an 88.9% sensitivity for pharyngeal NG. There was no discrepancy between the two assays for CT detection. The Cohen's Kappa coefficient of pooled specimen testing by the Xpert was 0.93 for NG and 1 for CT when compared to single-site testing by Abbott. Implementing pooled specimen testing by KP lay providers can be a cost-saving strategy to enhance the uptake of CT/NG services for populations facing increased risk.

Differentiated service delivery for HIV treatment models in Thailand: a cross-sectional assessment of real-world implementation and uptake

OBJECTIVES

First, to describe the antiretroviral therapy (ART) delivery models available in Thailand to understand differentiated service delivery (DSD) for further service system optimization and expansion of best practices; second, to determine the client characteristics associated with model uptake.

METHODS

Cross-sectional assessment using secondary data to describe ART models implemented as routine services at 4 public hospitals in 3 major provinces with a high HIV burden in Thailand. From April to October 2020, ART clients were screened consecutively according to the inclusion criteria: Thai, aged ≥18 years, and on ART for ≥6 months. HIV treatment models were categorized based on the service type, location, provider, and frequency. Logistic regression was used to identify the associated factors.

RESULTS

Seven individual ART delivery models were identified: 4 were facility-based and 3 were out-of-facility. No group models were identified. Of 3,366 records of ART clients reviewed, 3,213 (95.5%) met the study criteria and received ART through the following models: conventional (32.6%), nurse-led clinical consultation (10.0%), fast-track refill (29.0%), after-hours clinic (10.6%), pharmacist-led pickup center (3.6%), key population-led community-based organization (2.7%), and mailing (11.5%). Age, population, duration on ART, and VL were associated with the uptake of certain alternative service models when compared to the conventional model.

CONCLUSIONS

Among the variety of ART delivery approaches available in Thailand, facility-based models remain the most prevalent. Future work should investigate the role of client preference and choice in choosing service models and service utilization patterns over time, and assess the acceptability and effectiveness of these models.

The epidemiological impact and cost-effectiveness of key population-led PrEP delivery to prevent HIV among men who have sex with men in Thailand: A modelling study

Background

Although key populations (KPs), such as men-who-have-sex-with-men (MSM) are disproportionately affected by HIV, many prevention and treatment services are not easily accessible for KP members. To address the needs of KPs, Thailand established pre-exposure prophylaxis (PrEP) service delivery together with and led by KP members. This study determines the epidemiological impact and cost-effectiveness of key population-led (KP-led) PrEP.

Methods

We calibrated a compartmental deterministic HIV transmission model to the HIV epidemic among Thai MSM. Besides KP-led PrEP, we included other Thai service delivery models of PrEP (fee-based PrEP, the government PrEP program).Data on consistent PrEP use (5 years daily use, 95% effectiveness for preventing HIV) came from Thai PrEP delivery models. For the period 2015-2032, we ranged the number of PrEP starters (40,000-120,000), effectiveness of PrEP (45%-95%), and proportion of consistent users (10%-50%). The analysis started in 2015 when PrEP was introduced. A cost-effectiveness ratio of <160,000 Baht per quality-adjusted life year (QALY) over 40 years was cost-effective.

Findings

Without PrEP, 53,800 (interquartile range 48,700-59,700) new HIV infections are expected in 2015-2032. KP-led PrEP was found to have the strongest epidemiological impact of all delivery models averting 58% of infections compared to without PrEP. The epidemiological impact depends on the number of PrEP starters and proportion of consistent use. Although all PrEP service delivery models are cost-effective, KP-led PrEP is most cost-effective with incremental cost-effectiveness ratios of 28,000-37,300 Thai Baht per QALY.

Interpretation

Our model projects KP-led PrEP having the greatest epidemiological impact and being the most cost-effective service delivery model of PrEP in Thailand.

Funding

This study was supported by the US Agency for International Development and U.S. President's Emergency Plan for AIDS Relief through the Linkages Across the Continuum of HIV Services for Key Populations cooperative agreement (AID-OAA-A-14- 0045) managed by FHI 360.

Estradiol and Testosterone Concentrations Among Thai Transgender Women in a Transgender-Led, Integrated Gender-Affirming Care and Sexual Health Clinic: A Real-World Analysis

Purpose

Feminizing hormone therapy (FHT) is used by many transgender women as a pharmacological method to mitigate gender dysphoria. However, information on hormone concentrations among those who use FHT is lacking. We aimed to determine the proportion of Thai transgender women who were using FHT who had hormone concentrations within target ranges in a real-world clinic setting.

Methods

Transgender women who attended Tangerine Clinic in Bangkok, Thailand, reported current use of FHT at clinic entry, and tested for both blood estradiol (E2) and total testosterone (TT) concentrations were included in the analysis. Hormone target concentrations were defined as 100-200 pg/mL for E2 and <50 ng/dL for TT.

Results

Of 1534 transgender women included, 2.5% had undergone orchiectomy, and 524 (34.2%) had any hormones within target concentrations. Median (interquartile range) E2 and TT concentrations at baseline were 29 (14.3-45.3) pg/mL and 298.5 (22-646) ng/dL, respectively. Among those who had any hormones within target concentrations, 28 (1.8%), 11 (0.7%), and 485 (31.6%) had both hormones, only E2, and only TT within target concentrations, respectively. Among 1010 (65.8%) transgender women who had neither hormone within target concentrations, 989 (64.5%) and 21 (1.4%) had suboptimal and supraphysiological E2 concentrations, respectively. Among those who came to at least one follow-up visit (n=302), 165 (54.6%) transgender women managed to achieve or maintain either hormone within target concentrations.

Conclusion

One-third of Thai transgender women who were using FHT had any hormones within target concentrations at baseline in this real-world setting study. Most transgender women who had neither hormone within target concentrations had suboptimal rather than supraphysiological E2 concentrations. More than half managed to achieve or maintain at least one hormone concentration within target concentrations at follow-up visits, suggesting a positive effect from attending a trans-led, integrated gender-affirming care and sexual health service.

HIV prevalence and incidence among men who have sex with men and transgender women in Bangkok, 2014-2018: Outcomes of a consensus development initiative

To reach its goal of ending AIDS by 2030, Thailand has adopted antiretroviral treatment as prevention and HIV pre-exposure prophylaxis for men who have sex with men (MSM) and transgender women (TGW) as its core HIV control strategy. However, in the absence of reliable epidemiologic indicators, the impact of these policies on the course of the HIV epidemic in these groups remains unknown. To help answer this question, we formulated an HIV epidemic consensus initiative for Bangkok, Thailand, to analyze epidemiologic and program data and reach agreement between experts and stakeholders on the evolving state of the HIV epidemic among MSM and TGW. A customized Delphi process was used to consult and consolidate viewpoints of experts and stakeholders. Experts presented and discussed HIV prevalence and incidence data from recent and ongoing studies among MSM and TGW in Bangkok (2014 to 2018) during a meeting with stakeholders representing government, donors, and civil society. Agreement about the course of the HIV epidemic among MSM and TGW was attained by voting consensus. Based on presented data, meeting participants agreed that HIV prevalence and incidence had decreased among Bangkok MSM from 2014 to 2018. Despite these declines, HIV prevalence and incidence were found to remain high. This was particularly the case among younger MSM. Participants agreed that there was no evidence for a decrease in HIV prevalence and incidence among Bangkok TGW. Introduction of antiretroviral treatment as prevention and HIV pre-exposure prophylaxis may have contributed to these declines. However, HIV prevalence and incidence remained high, and no signs of a decrease were reported among Bangkok TGW. At the current rate of new HIV infections in MSM and TGW, Thailand will not reach its goal of ending AIDS by 2030. This HIV consensus initiative may serve as a model for building agreement and advocacy on epidemiologic and program data and their implications for a large metropolitan city.

Prevalence and the associated factors of hepatitis B and hepatitis C viral infections among HIV-positive individuals in same-day antiretroviral therapy initiation program in Bangkok, Thailand

Background

Viral hepatitis is highly prevalent among people with HIV (PWH) and can lead to chronic liver complications. Thailand started universal hepatitis B vaccination at birth in 1992 and achieved over 95% coverage in 1999. We explored the prevalence of hepatitis B and C viral infections and the associated factors among PWH from same-day antiretroviral therapy (SDART) service at the Thai Red Cross Anonymous Clinic, Bangkok, Thailand.

Methods

We collected baseline characteristics from PWH enrolled in the SDART service between July 2017 and November 2019. Multivariable logistic regression was performed to determine factors associated with positive hepatitis B surface antigen (HBsAg) and hepatitis C antibody (anti-HCV).

Results

A total of 4011 newly diagnosed PWH who had HBsAg or anti-HCV results at baseline: 2941 men who have sex with men (MSM; 73.3%), 851 heterosexuals (21.2%), 215 transgender women (TGW; 5.4%), and 4 transgender men (0.1%). Median age was 27 years. Overall seroprevalence of HBsAg and anti-HCV were 6.0 and 4.1%, respectively. Subgroup prevalence were 6.2 and 4.7% among MSM, 4.6 and 2.4% among heterosexuals, and 9.3 and 3.7% among TGW, respectively. Factors associated with HBsAg positivity were being MSM, TGW, born before 1992, CD4 count < 200 cells/mm³, and alanine aminotransferase ≥ 62.5 U/L. Factors associated with anti-HCV positivity were being MSM, age > 30 years, alanine aminotransferase ≥ 62.5 U/L, creatinine clearance < 60 ml/min, and syphilis infection.

Conclusions

Around 5–10% of newly diagnosed PWH in Bangkok had hepatitis B viral infection after 25 years of universal vaccination. Anti-HCV positivity was found in 4–5% of PWH who were MSM and TGW. As World Health Organization and Thailand national guidelines already support routine screening of hepatitis B and C viral infections in PWH and populations at increased risk of HIV including MSM and TGW, healthcare providers should reinforce this strategy and provide linkage to appropriate prevention and treatment interventions. Catch-up hepatitis B vaccination should be made available under national health coverage.

Evaluation of the integration of telehealth into the same-day antiretroviral therapy initiation service in Bangkok, Thailand in response to COVID-19: a mixed-method analysis of real-world data

Introduction

Same‐day antiretroviral therapy (SDART) initiation has been implemented at the Thai Red Cross Anonymous Clinic (TRCAC) in Bangkok, Thailand, since 2017. HIV‐positive, antiretroviral therapy (ART)‐naïve clients who are willing and clinically eligible start ART on the day of HIV diagnosis. In response to the first wave of the coronavirus disease 2019 (COVID‐19) outbreak in March 2020, telehealth follow‐up was established to comply with COVID‐19 preventive measures and allow service continuation. Here, we evaluate its implementation.

Methods

Pre‐COVID‐19 (until February 2020) clients who initiated SDART received a 2‐week ART supply and returned to the clinic for evaluation before being referred to long‐term ART maintenance facilities. If no adverse events (AEs) occurred, another 8‐week ART supply was provided while referral was arranged. During the first wave of COVID‐19 (March–May 2020), clients received a 4‐week ART supply and the option of conducting follow‐up consultation and physical examination via video call. Clients with severe AEs were required to return to TRCAC; those without received another 6‐week ART supply by courier to bridge transition to long‐term facilities. This adaptation continued post‐first wave (May–August 2020). Routine service data were analysed using data from March to August 2019 for the pre‐COVID‐19 period. Interviews and thematic analysis were conducted to understand experiences of clients and providers, and gain feedback for service improvement.

Results

Of 922, 183 and 321 eligible clients from the three periods, SDART reach [89.9%, 96.2% and 92.2% (p = 0.018)] and ART initiation rates [88.1%, 90.9% and 94.9% (p<0.001)] were high. ART uptake, time to ART initiation and rates of follow‐up completion improved over time. After the integration, 35.3% received the telehealth follow‐up. The rates of successful referral to a long‐term facility (91.8% vs. 95.3%, p = 0.535) and retention in care at months 3 (97.5% vs. 98.0%, p = 0.963) and 6 (94.1% vs. 98.4%, p = 0.148) were comparable for those receiving in‐person and telehealth follow‐up. Six clients and nine providers were interviewed; six themes on service experience and feedback were identified.

Conclusions

Telehealth follow‐up with ART delivery for SDART clients is a feasible option to differentiate ART initiation services at TRCAC, which led to its incorporation into routine service.

Acceptability and satisfaction towards self-collection for chlamydia and gonorrhoea testing among transgender women in Tangerine Clinic, Thailand: shifting towards the new normal

Introduction

Provider‐collected swabs are an unappealing procedure for many transgender women and may have led to suboptimal rates of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) testing. Self‐collection for CT/NG testing is recommended for men who have sex with men. However, the information on acceptability and clinical performance to support a recommendation for transgender women is lacking. We aimed to determine the acceptability and satisfaction towards self‐collection for CT/NG testing among Thai transgender women.

Methods

Thai transgender women who attended Tangerine Clinic (a transgender‐led, integrated, gender‐affirming care and sexual health services clinic in Bangkok, Thailand) between May and July 2020 and had condomless sexual intercourse within the past six months were offered to collect urine and perform self‐swabs of pharyngeal, rectal, and if applicable, neovaginal compartments for pooled nucleic acid amplification testing for CT/NG infections. Participants received a diagram, video and oral instructions about how to perform self‐collection procedure. Those who accepted self‐collection were also offered to receive provider collection to evaluate the performance between the two methods. Self‐administered questionnaires were used to assess satisfaction.

Results

Among 216 transgender women enrolled, 142 (65.7%) accepted self‐collection. All who accepted had pharyngeal, rectal and urine samples collected. Of 31 transgender women who had undergone genital surgery, 28 (90.3%) accepted neovaginal self‐swab. The acceptance rate increased from 46.2% in May to 84.5% in July 2020. One participant had an invalid result. All transgender women who accepted self‐collection could perform it without assistance, and 82.8% were highly satisfied with the method. None reported dissatisfaction. Due to the COVID‐19 pandemic, provider collection services were discontinued early, and only eight transgender women were able to perform both methods for performance evaluation. The performance agreement was 100%.

Conclusions

Thai transgender women had high acceptability and satisfaction towards self‐collection for CT/NG testing. The performance was promising compared to provider collection. Our results support the implementation of self‐collection to the sexually transmitted infection services, particularly during the COVID‐19 pandemic where physical distancing is the new normal. A larger study is warranted to determine the performance of self‐collection for CT/NG testing in each anatomical compartment and confirm the performance between self‐collection and provider collection.

Uptake of oral fluid-based HIV self-testing among men who have sex with men and transgender women in Thailand

Background

Suboptimal uptake of HIV testing remains a primary bottleneck to HIV prevention and treatment for men who have sex with men (MSM) and transgender women (TGW) in Thailand. The World Health Organization has recommended HIV self-testing (HIVST) as an additional strategic HIV service. However, HIVST has not been fully endorsed and implemented in many countries in Southeast Asia. The aim of this study was to assess the uptake of oral fluid-based HIVST in MSM and TGW populations in Thailand.

Methods

During 2017 and 2018, we conducted a cross-sectional study using convenience sampling to enroll 2,524 participants from three major urban areas. Participants were recruited during outreach and online activities and were offered unassisted or assisted HIVST, or referral to HIV testing services. A descriptive analysis was performed for summarizing data.

Results

A total of 2,502 participants (1,422 MSM and 1,082 TGW) were included in the analysis with about one-third (36.1%) of them being first-time testers. Among all participants enrolled in the study, a total of 2,486 participants (99.3%) selected HIVST versus referral to HIV testing services. Of those who selected HIVST, 2,095 (84.3%) opted for assisted HIVST while the rest opted for unassisted HIVST: 1,148 of 1,411 MSM (81.4%) and 947 of 1,075 TGW (88.1%) selected assisted HIVST. While no serious adverse events were reported during the study, we found that among 179 participants who needed a confirmatory test and were referred to HIV testing services, 108 (60.3.4%) accessed these later services.

Conclusions

This study demonstrated a high uptake of oral fluid-based HIVST among MSM and TGW populations in Thailand and that HIVST could be scaled up through the national epidemic control program. However, a better understanding of HIV testing-seeking behavior and innovative follow-up solutions are needed to improve and monitor linkages to services for people who undertake HIVST.

Evaluation of a pre-exposure prophylaxis programme for men who have sex with men and transgender women in Thailand: learning through the HIV prevention cascade lens

INTRODUCTION

Men who have sex with men (MSM) and transgender women (TGW) are two key populations (KPs) in Thailand at high risk for HIV. Uptake and scale-up of pre-exposure prophylaxis (PrEP) among them has been slow. We used data from Princess PrEP, Thailand's largest KP-led PrEP programme, to operationalize PrEP service cascades. We identified gaps and pointed out where additional data are needed to inform a larger HIV prevention cascade.

METHODS

Numbers of people tested for HIV, tested HIV negative, eligible for PrEP (defined as any of the following in the past three months: condomless sex with partners of unknown/uncertain HIV status or antiretroviral treatment or viral load status, multiple partners, engaging in sex work, sexually transmitted infections, injecting drugs, using amphetamine-type stimulants, or repeated use of post-exposure prophylaxis), offered PrEP and accepted PrEP during January to November 2019 were retrieved from Princess PrEP database to inform PrEP service cascades for MSM and TGW. Reasons for not accepting PrEP were documented.

RESULTS

Of 6287 MSM who received HIV testing in Princess PrEP, 92.3% were HIV negative and 70.2% of them were eligible for PrEP. PrEP was offered to 94.7% of those eligible and 48.0% of those offered accepted it. Among 900 TGW who had HIV testing, 95.3% tested HIV negative and 64.8% of them met PrEP eligibility criteria. Of these, 95.0% were offered PrEP and 43.9% of them accepted it. Among MSM and TGW who met PrEP eligibility criteria, no or low-HIV-risk perception was the most common reason provided (46.7% of 2007 MSM and 41.9% of 296 TGW) for not accepting PrEP.

CONCLUSIONS

PrEP service cascades from the Princess PrEP programme identified no or low-risk perception as key barrier to PrEP acceptance among MSM and TGW who met PrEP eligibility criteria. More implementation research studies are needed to explore PrEP motivation and access in larger communities outside of clinical services. This is to identify gaps and strategies to address them within motivation, access and effective use domains of the HIV prevention cascade.

Discordance between self-perceived and actual risk of HIV infection among men who have sex with men and transgender women in Thailand: a cross-sectional assessment

INTRODUCTION

Low uptake of HIV testing and services, including pre-exposure prophylaxis (PrEP), in Thai men who have sex with men (MSM) and transgender women (TGW) may be due to the inaccuracy in self-risk assessment. This study investigated the discordance between self-perceived HIV risk and actual risk.

METHODS

Data were obtained between May 2015 and October 2016 from MSM and TGW enrolled in key population-led Test and Treat study in six community health centres in Thailand. Eligible participants were at least 18 years old, Thai national, had sex with men, had unprotected sex with a man in the past six months or had at least three male sex partners in the past six months, and were not known to be HIV positive. Baseline demographic behavioural characteristics questionnaires, including self-perceived HIV risk, were self-administered. Participants received HIV/STI (syphilis/gonorrhoea/chlamydia) testing at baseline. Participants who self-perceived to have low risk, but engaged in HIV-susceptible practices were categorized as having risk discordance (RD). Regression was conducted to assess factors associated with RD among MSM and TGW separately.

RESULTS

Of the 882 MSM and 406 TGW participants who perceived themselves as having low HIV risk, over 80% reported at least one of the following: tested HIV positive, engaged in condomless sex, tested positive for a sexually transmitted infection sexually transmitted infection (STI; or used amphetamine-type stimulants. Logistic regression found that living with a male partner (p = 0.005), having never tested for HIV (p = 0.045), and living in Bangkok (p = 0.01) and Chiang Mai (p < 0.001) were associated with increased risk discordance among MSM. Living with a male partner (p = 0.002), being less than 17 years old at sexual debut (p = 0.001), and having a low knowledge score about HIV transmission (p < 0.001) were associated with increased risk discordance among TGW. However, for TGW, being a sex worker decreased the chance of risk discordance (p = 0.034).

CONCLUSIONS

Future HIV prevention messages need to fill in the gap between self-perceived risk and actual risk in order to help HIV-vulnerable populations understand their risk better and proactively seek HIV prevention services.

Water Vapor, Clouds, and Saturation in the Tropical Tropopause Layer

The goal of this investigation is to understand the mechanism behind the observed high relative humidity with respect to ice (RHi) in the tropical region between ~14 km (150 hPa) and the tropopause, often referred to as the tropical tropopause layer (TTL). As shown by satellite, aircraft and balloon observations, high (>80%) RHi regions are widespread within the TTL. Regions with the highest RHi are co-located with extensive cirrus. During boreal winter, the TTL RHi is highest over the Tropical Western Pacific (TWP) with a weaker maximum over South America and Africa. In the winter, TTL temperatures are coldest and upward motion is the greatest in the TWP. It is this upward motion, driving humid air into the colder upper troposphere that produces the persistent high RHi and cirrus formation. Back trajectory calculations show that comparable adiabatic and diabatic processes contribute to this upward motion. We construct a bulk model of TWP TTL water vapor transport that includes cloud nucleation and ice microphysics that quantifies how upward motion drives the persistent high RHi in the TTL region. We find that atmospheric waves triggering cloud formation regulate the RHi, and that convection dehydrates the TTL. Our forward domain-filling trajectory (FDF) model is used to more precisely simulate the TTL spatial and vertical distribution of RHi. The observed RHi distribution is reproduced by the model and we show that convection increases RHi below the base of the TTL with little impact on the RHi in the TTL region.

Correlates of nonadherence to key population-led HIV pre-exposure prophylaxis services among Thai men who have sex with men and transgender women

Background

Based on government estimates from the Asian Epidemic Model, new infections among men who have sex with men (MSM) and transgender women (TGW) in Thailand are forecast to proportionally increase over time. Daily oral Pre-exposure prophylaxis (PrEP) protects against HIV acquisition when used as prescribed. The “Princess PrEP” program is the first key population-led (PrEP) initiative under Thai royal patronage with an aim to scale up countrywide implementation of PrEP.

Methods

Retention in and adherence to key population-led HIV PrEP services among HIV-uninfected Thai MSM and TGW was examined in four provinces: Bangkok, Chonburi, Chiang Mai, and Songkhla. HIV, HBsAg, creatinine tests, and self-administered questionnaires were performed during baseline measures. Participants were followed up after month 1, at month 3, then every 3 months. Correlates of nonadherence and loss to follow up at 1 month were assessed using linear regression models.

Results

37.4% of the participants reported low adherence to services (≤ 3 pills/week or missed clinic schedule at month 1). Factors associated with low adherence included younger age (25 years and under) (adjusted odds ratio (aOR): 1.49, 95% confidence interval (95% CI: 1.01–2.21, p = 0.044), being a TGW (aOR: 2.2, 95% CI: 1.27–3.83, p = 0.005), and whether the participant had not previously accessed services at the clinic (aOR = 1.68, 95% CI: 1.03–2.76, p = 0.04). Additionally, participants in Chonburi (the only TGW site) showed significantly lower adherence than those in the other three provinces (aOR: 2.91, 95% CI: 1.55–5.45, p = 0.001).

Conclusion

Urgent, innovative interventions for early PrEP adherence support among vulnerable sub-populations such as younger users, TGW, and new clients are needed to maximize prevention strategy in Thailand.

Electronic supplementary material

The online version of this article (10.1186/s12889-019-6645-0) contains supplementary material, which is available to authorized users.

Pinning and depinning: From periodic to chaotic and random media

We study the propagation of dissipative structures in inhomogeneous media with a focus on pinning and depinning transitions. We model spatial complexity in the medium as generated by dynamical systems. We are thus able to capture transitions from periodic to quasiperiodic, to homoclinic and heteroclinic, and to chaotic media. Depinning bifurcations exhibit universal laws depending on extreme value statistics that are encoded in the dimension of ergodic measures, only. A key condition limiting this approach bounds spatial Lyapunov exponents in terms of interface localization, and we explore the breakdown of smoothness and universality when this condition is violated and fluctuations in the medium occur on length scales shorter than a typical interface width.

Water Production Activity of Nine Long-Period Comets from SOHO/SWAN Observations of Hydrogen Lyman-alpha: 2013-2016

Nine recently discovered long-period comets were observed by the Solar Wind Anisotropies (SWAN) Lyman-alpha all-sky camera on board the Solar and Heliosphere Observatory (SOHO) satellite during the period of 2013 to 2016. These were C/2012 K1 (PanSTARRS), C/2013 US10 (Catalina), C/2013 V5 (Oukaimeden), C/2013 R1 (Lovejoy), C/2014 E2 (Jacques), C/2014 Q2 (Lovejoy), C/2015 G2 (MASTER), C/2014 Q1 (PanSTARRS) and C/2013 X1 (PanSTARRS). Of these 9 comets 6 were long-period comets and 3 were possibly dynamically new. Water production rates were calculated from each of the 885 images using our standard time-resolved model that accounts for the whole water photodissociation chain, exothermic velocities and collisional escape of H atoms. For most of these comets there were enough observations over a broad enough range of heliocentric distances to calculate power-law fits to the variation of production rate with heliocentric distances for pre- and post-perihelion portions of the orbits. Comet C/2014 Q1 (PanSTARRS), with a perihelion distance of only ~0.3 AU, showed the most unusual variation of water production rate with heliocentric distance and the resulting active area variation, indicating that when the comet was within 0.7 AU its activity was dominated by the continuous release of icy grains and chunks, greatly increasing the active sublimation area by more than a factor of 10 beyond what it had at larger heliocentric distances. A possible interpretation suggests that a large fraction of the comet's mass was lost during the apparition.

Princess PrEP program: the first key population-led model to deliver pre-exposure prophylaxis to key populations by key populations in Thailand

Background No data are available on the feasibility of pre-exposure prophylaxis (PrEP) delivered by trained key population (KP) community health workers. Herein we report data from the KP-led Princess PrEP program serving men who have sex with men (MSM) and transgender women (TGW) in Thailand. Methods: From January 2016 to December 2017, trained MSM and TGW community health workers delivered same-day PrEP service in community health centres, allowing clients to receive one PrEP bottle to start on the day of HIV-negative testing. Visits were scheduled at Months 1 and 3, and every 3 months thereafter. Uptake, retention and adherence to PrEP services and changes in risk behaviours over time are reported. Results: Of 1467 MSM and 230 TGW who started PrEP, 44.1% had had condomless sex in the past 3 months. At Months 1, 3, 6, 9 and 12, retention was 74.2%, 64.0%, 56.2%, 46.7% and 43.9% respectively (lower in TGW than MSM at all visits; P&lt;0.001), with adherence to at least four PrEP pills per week self-reported by 97.4%, 96.8%, 96.5%, 97.5% and 99.5% of respondents respectively (no difference between MSM and TGW). Logistic regression analysis identified age &gt;25 years, being MSM and having at least a Bachelors degree significantly increased retention. Condomless sex did not change over the 12-month period (from 47.2% to 45.2%; P=0.20). New syphilis was diagnosed in 4.9% and 3.0% of PrEP clients at Months 6 and 12 (cf. 7.0% at baseline; P=0.007). Among PrEP adherers and non-adherers, there were one and six HIV cases of seroconversion respectively, which resulted in corresponding HIV incidence rates (95% confidence interval) of 0.27 (0.04–1.90) and 1.36 (0.61–3.02) per 100 person-years. Conclusion: Our KP-led PrEP program successfully delivered PrEP to MSM and TGW. Innovative retention supports are needed, especially for TGW and those who are young or with lower education levels. To scale-up and sustain KP-led PrEP programs, strong endorsement from international and national guidelines is necessary.

Affected by HIV stigma: interpreting results from a population survey of an urban center in Guangxi, China

We aimed to identify factors related to HIV stigma in Liuzhou, Guangxi province, a city in southwest China with high HIV prevalence. We used a multi-stage cluster randomized sample of the general population to survey 852 adults. We conducted ordinal logistic regression analyses to test factors associated with punishment and isolation stigma. Eighteen percent of respondents agreed that people with HIV should be punished, and 40% agreed that people living with HIV (PLHIV) should be isolated. Punishment stigma was associated with age, having three or more sexual partners, and TV watching. Isolation stigma was associated with age, urban residence and a history of STI. HIV transmission knowledge was low, and having correct knowledge attenuated the association with punishment and isolation stigma. Despite programs in China to provide care and treatment for PLHIV, HIV stigma is common in this region. Targeted interventions need to focus on fears related to HIV and PLHIV.

Bringing smart pills to market: FDA regulation of ingestible drug/device combination products

Imagine a pill that, after you swallow it, can track its position in your body. Or imagine a pill that can transmit a message to a doctor to tell him that you have taken your bitter medicine. Pills like this already exist. These so-called smart pills are an emerging type of medical therapy. However, this nascent technology has yet to reach the market and developers of these novel therapies face significant regulatory challenges. This article predicts how the Food and Drug Administration will regulate smart pills and shows how the current regulatory regime is inadequate. The article then proposes modifying the current regulatory regime to encourage development of smart pills and other innovative combination products by: (1) regulating combination products based on their "novel mode of action" rather than their "primary mode of action," (2) creating a marketing approval pathway specifically for combination products, and (3) eliminating regulations that require sponsors to get marketing approval from multiple centers within FDA and providing regulatory guidance specifically for ingestible drug/device combination products.

Personalized medicine and rescuing "unsafe" drugs with pharmacogenomics: a regulatory perspective

The sequencing of the human genome and the revolution it has caused in biomedical science created hope for a new era in the prevention and treatment of serious illnesses. In the area of drug development, much of this hope is focused in the field of pharmacogenomics (PGx), which is the study of how individual genetic differences affect drug response. Many people expected advances in pharmacogenomics to lead to the rapid development of new "personalized medicines," where drugs and dosages could be tailored specifically to a patient's genotype. However, pharmacogenomics has largely failed to meet these expectations and the Food and Drug Administration has only approved a handful of drugs that rely on PGx data. This article evaluates how FDA regulates the use of pharmacogenomics and discusses how the current regulatory scheme fails to provide an adequate route for developing personalized medicine. The article then proposes modifying the current regulatory regime to encourage development of PGx-based drugs by either allowing PGx-based drugs to be approved with unvalidated biomarkers if the sponsor commits to Phase IV studies or using the Orphan Drug Act to provide economic incentives.

The in Vitro Plasma Distribution of a Novel Cholesteryl Ester Transfer Protein Inhibitor, Torcetrapib, Is Influenced by Differences in Plasma Lipid Concentrations

PURPOSE

To determine the lipoprotein distribution of Torcetrapib in normolipidemic or hyperlipidemic human plasma and assess any changes in distribution due to lipid profile.

METHODS

Torcetrapib was incubated with human plasma samples, and the distribution was measured across four fractions: triglyceride-rich lipoprotein (TRL), low-density lipoprotein, high-density lipoprotein, and lipoprotein-deficient plasma fraction. Two stocks of human plasma were used, one considered normolipidemic (total cholesterol concentration = 164 mg/dL, triglycerides concentration = 139 mg/dL, protein concentration = 912 mg/dL), the other hyperlipidemic (total cholesterol = 260 mg/dL, triglycerides = 775 mg/dL, protein = 917 mg/dL). The plasma samples were incubated with Torcetrapib at 37 degrees C, and the incubation was stopped with the addition of sodium bromide and cooling to 4 degrees C. The plasma samples were then separated by density gradient ultracentrifugation to their lipoprotein fractions. The resulting lipoprotein fractions and an aliquot of incubated plasma were analyzed by a validated gas chromatography/tandem mass spectrometry analytical method. The distribution of Torcetrapib was determined first with varying incubation times, then with several concentrations.

RESULTS

At concentrations of 250 and 500 ng/mL, Torcetrapib distributed evenly across the four fractions in normolipidemic plasma. At the same concentrations in hyperlipidemic plasma, approximately 84% of Torcetrapib was found in the TRL fraction, with the remaining 16% evenly partitioned between the low-density lipoprotein, high-density lipoprotein, and lipoprotein-deficient plasma fractions.

CONCLUSIONS

The results suggest that lipid profile affects the distribution of Torcetrapib in hyperlipidemic human plasma lipoprotein fractions. The preferential distribution of Torcetrapib into the TRL fraction in hyperlipidemic plasma needs to be investigated to see if it will affect the pharmacological effect of Torcetrapib in vivo.

Novel field sampling procedure for the determination of methiocarb residues in surface waters from rice fields

Methiocarb was extracted from surface water samples collected at experimental rice field sites in Louisiana and Texas. The sampling system consisted of a single-stage 90-mm Empore extraction disk unit equipped with a battery-powered vacuum pump. After extraction, the C-18 extraction disks were stored in an inert atmosphere at -10 degrees C and shipped overnight to the laboratory. The disks were extracted with methanol and the extracts analyzed by reversed-phase high-performance liquid chromatography with a methanol/water mobile phase. Methiocarb was detected by ultraviolet absorption at 223 nm and quantified with the use of calibration standards. Recoveries from control surface water samples fortified at 5.0, 10, 50, and 100 ng/mL methiocarb averaged 92 +/- 7%. A method limit of detection for methiocarb in rice field surface water was estimated to be 0.23 ng/mL at 223 nm.

Technology-enhanced distance education: from experimentation to concerted action

Despite the rush to embrace technology-enhanced learning (TEL), descriptions of how schools of nursing move toward systemwide implementation of this type of teaching are scarce. There is a wide gap between sporadic dabbling by individual instructors in specific courses and adoption and implementation of TEL throughout a program. This article describes the experiences of a group of nursing faculty who helped move one school of nursing from experimentation with TEL in distance education to concerted action toward a strategic schoolwide plan. J Prof Nurs 17:135-140, 2001.

Improving the selectivity of HAV-peptides in modulating E-cadherin-E-cadherin interactions in the intercellular junction of MDCK cell monolayers

PURPOSE

The objective of this work is to understand the sequence specificity of HAV peptides and to improve their selectivity in regulating E-cadherin-E-cadherin interactions in the intercellular junctions.

METHODS

Peptide 1 was modified using an alanine scanning method to give peptides 2-6. The ability of these peptides to modulate intercellular junctions was evaluated using Madin-Darby Canine Kidney (MDCK) cell monolayers on Transwell membranes from either the apical (AP) or the basolateral (BL) side. Modulation of the intercellular junctions was measured by the ability to lower the transepithelial electrical resistance (TEER) of MDCK monolayers and by the increase in mannitol flux. Molecular docking experiments were performed to model the binding properties of these peptides to the EC1 domain of E-cadherin.

RESULTS

Peptides 5 (Ac-SHAVAS-NH2) and 6 (Ac-SHAVSA-NH2) were found to be more effective than the parent peptide 1 in decreasing the resistance of the cell monolayer. Furthermore, comparative studies with the control and the weak inhibitor peptide 2 indicate that peptide 5 displayed a significant increase in mannitol flux. Molecular docking of peptides 1, 2 and 5 to the EC1 domain suggests that peptide 5 has the lowest binding energy.

CONCLUSIONS

HAV peptides have the ability to modulate E-cadherin-E-cadherin interactions in the intercellular junctions of the MDCK cell monolayer, thus indirectly increasing the permeability of the tight junctions. This observation indicates that residues flanking the HAV sequence are important in the binding selectivity of HAV peptides to E-cadherin. Molecular docking can further aid in the design of peptides with better selectivity to the EC1 domain of E-cadherin.

Functional expression of P-glycoprotein in primary cultures of human cytotrophoblasts and BeWo cells

The objective of this study was to investigate the functional expression of the efflux transporter, P-glycoprotein (P-gp), in primary cultures of human cytotrophoblasts and BeWo cell monolayers. Uptake studies with primary cultures of human cytotrophoblasts or BeWo cells were conducted with calcein-AM and vinblastine (P-gp markers) or fluorescein (MRP marker) in the presence of specific P-gp or MRP inhibitors. Results showed that the accumulation of P-gp substrates calcein-AM and vinblastine by BeWo cells or primary cultures of human cytotrophoblasts was significantly enhanced in the presence of a typical P-gp inhibitor, cyclosporin-A, or other inhibitors such as quinidine, verapamil, and dipyridamole. MRP inhibitors had no effect on the accumulation of calcein or fluorescein by BeWo cells. Western blots confirmed the presence of multidrug resistant gene product 1 (MDR1) in both primary cultures of human cytotrophoblasts and BeWo cells. This study demonstrates functional P-gp in term human trophoblasts and further supports the use of primary cultures of human cytotrophoblasts and BeWo cells as in vitro models of the trophoblast to investigate mechanisms regulating drug distribution across the placenta.

A theory of planned behavior-based structural model for breast-feeding

BACKGROUND

Breast-feeding is the recommended method of infant feeding because it is clearly associated with health benefits for infants and their mothers. Yet, many women who initiate breast-feeding fail to meet their own personal goals or recommended standards for duration of breast-feeding.

OBJECTIVE

To refine a Theory of Planned Behavior (TPB)-based structural model for explaining variability in breast-feeding intention and duration.

METHOD

The study design was prospective, multicorrelational, and longitudinal. Out of the total sample of 635 women, 602 mothers of healthy, full-term infants provided complete datasets over the entire course of their breast-feeding experience and these datasets were used in the modeling analyses. Simultaneous multisample analysis of covariance structures was used to develop the model.

RESULTS

The resulting TPB for Breast-Feeding (TPB-BrF) describes the rational, motivational processes of the original TPB, but reconfigures the relationships among them, for homemakers (TPB-BrF/H), women employed half-time or less (TPB-BrF/EL), and women employed more than half-time (TPB-BrF/EM). Mothers' early postpartum ratings of adequacy of milk supply and stimulus conditions of maternal education and breast-feeding knowledge were included in the TPB-BrF to better explain breast-feeding outcomes. Model complexity increased with employment effort.

CONCLUSION

The TPB-BrF is a comprehensive, theoretically based, empirically verified model that can serve as a useful heuristic for understanding the personal motivational components of breast-feeding behavior.

Factors associated with very early weaning among primiparas intending to breastfeed

OBJECTIVES

The major objective of this study was to identify predictor variables that accurately differentiated breastfeeding women who weaned during the first 4 weeks, those who weaned between 5 and 26 weeks, and those who weaned after 26 weeks. Predictors were demographic variables, Theory of Planned Behavior (TPB) variables, breastfeeding knowledge, and difficulties experienced during the first month.

METHODS

Primiparas who delivered healthy infants in an urban midwestern hospital provided initial data prior to discharge. Follow-up occurred at 1, 3, 6, 9, and 12 months. Following appropriate bivariate analyses, polychotomous logistic regression was used to determine predictors of weaning group. Linear multiple regression was used to predict intended duration.

RESULTS

Most of the 84 women who weaned very early had intended to breastfeed considerably longer. According to the multivariate analysis, women who weaned earlier were younger, had completed fewer years of education, had a more positive bottle-feeding attitude and a less positive breastfeeding attitude, intended to breastfeed less time, had lower knowledge scores, had higher perceived insufficient milk scores, and planned to work outside the home. Variables postulated by the TPB to be direct predictors of intention explained 36% of the variance in intended duration.

CONCLUSIONS

Women at risk for early weaning can be identified with reasonable accuracy using a TPB-based conceptual framework expanded to include breastfeeding specific variables. Casefinding using empirically derived screening methods and careful postpartum follow-up, along with professional intervention, should be used to avert unintended early weaning.

Permeability and metabolic properties of a trophoblast cell line (HRP-1) derived from normal rat placenta

The HRP-1 cell line is derived from normal rat placenta and appears morphologically similar to and retains characteristic expression of cellular markers of labyrinthine trophoblast cells. In this study, monolayers of HRP-1 cells grown on permeable supports were evaluated as a potential in vitro system to study trophoblast transport and metabolism. The cell line was shown to express and retain functional activity of the predominant placental cytochrome P450 isozyme, CYP1A1. Additionally, the HRP-1 cells retain functional activity of angiotensin I converting enzyme and carboxypeptidase N-like enzyme, peptidases characteristic of the trophoblast. The permeation of several hydrophilic, inert markers across the HRP-1 monolayers was observed to be dependent on effective molecular size and to be passive in nature. Functional asymmetry of the HRP-1 cells was illustrated by the predominant permeation of linoleic acid in the apical-to-basolateral direction across the monolayers. Transferrin passage across HRP-1 monolayers was concentration-dependent, was bidirectional, and could be inhibited by unlabeled transferrin, features typical of the trophoblast transport system for transferrin. Collectively, these properties suggest that the HRP-1 cell line may provide a useful tool for evaluating some of the permeability and metabolic properties of the trophoblast.

Sentinel lymph node metastasis in experimental melanoma: relationships among primary tumor size, lymphatic vessel diameter and 99mTc-labeled human serum albumin clearance

BACKGROUND

This study was designed to investigate the relationships among primary tumor size, lymphatic vessel diameters, the incidence of sentinel lymph node (SLN) metastasis and lymphatic clearance from murine footpad melanomas.

METHODS

Lymphatic clearance (LC) of [99mTc]HSA from the middle of the footpad of syngeneic C57BL/6 mice, with or without primary melanomas (sizes varying from 1 to 5 mm in anteroposterior diameter), was quantitated using a gamma scintillation detection system. Lymphatic vessel diameters (LD) were measured after injection of aniline blue dye into footpad tumors. The incidence of SLN, femoral lymph node (FLN), and lung metastases was recorded.

RESULTS

Metastasis to SLNs increased as tumor growth progressed (r = 0.976, p = 0.001), and there was a correlation between tumor size and both FLN (p = 0.041) and lung (p = 0.055) metastases. There was also a correlation between lymph node metastasis and LC (r = 0.83, p = 0.04) and LD (r = 0.84, p = 0.04).

CONCLUSIONS

These studies support the hypothesis that lymph flow and LD is increased in experimental murine melanomas and this relates to both primary tumor size and to lymphatic and hematogenous metastasis.