Smoking and Type 1 Versus Type 2 Myocardial Infarction Among People With HIV in the United States.

ABSTRACT: Smoking is a myocardial infarction (MI) risk factor among people with HIV (PWH). Questions persist regarding the role of smoking behaviors and measurements (e.g., intensity, duration) on MI risk. We used Cox proportional hazards regression to compare the association of smoking parameterization with incidents of type 1 and type 2 MI and whether smoking intensity or duration improves MI risk prediction among PWH. Among 11,637 PWH, 37% reported currently smoking, and there were 346 MIs. Current smoking was associated with type 1 (84% increased risk) but not type 2 MI in adjusted analyses. The type 1 MI model with pack years had the best goodness of fit compared with other smoking parameterizations. Ever or never parameterization and smoking diagnosis data had significantly poorer model fit. These results highlight the importance of differentiating MI types and performing patient-based smoking assessments to improve HIV care and research rather than relying on smoking status from diagnoses.

Behavioral and Health Outcome Differences by Heroin or Methamphetamine Preference Among People in Rural US Communities Who Use Both Substances.

Background: The United States' (US) opioid overdose epidemic has evolved into a combined stimulant/opioid epidemic, a pattern driven in part by mitigating opioid overdose risk, variable substance availability, and personal preferences. This study aimed to investigate the association between self-reported substance preference (heroin or methamphetamine) and behavioral/health outcomes among individuals who used both heroin and methamphetamine in the rural US. Methods: The Rural Opioid Initiative is a consortium of 8 research cohorts from 10 states and 65 rural counties that recruited individuals reporting past 30-day injection of any substance or opioid substance use by any route from 1/2018 to 3/2020. Analyses were restricted to participants ⩾18 years, who self-reported either heroin or methamphetamine as their preferred substance and past 30-day use of both heroin and methamphetamine. We examined cross-sectional associations between preferred substance (heroin versus methamphetamine) and behavioral and health outcomes using random effects meta-analysis with adjusted regression models. Results: Among 1239 participants, 61% (n = 752) reported heroin as their preferred substance. Adjusting for age, sex, and race/ethnicity, methamphetamine preference was associated with lower prevalence ratios for current naloxone possession (adjusted prevalence ratio [aPR] = 0.68; 95% Confidence Interval [95% CI] = 0.59-0.78; P-value ⩽ .001), of ever being told they had the hepatitis C virus (HCV; aPR = 0.72; 95% CI: 0.61-0.85; P-value ⩽ .001) and a personal history of overdose (aPR = 0.81; 95% CI = 0.73-0.90; P-value ⩽ .001). Conclusion: In our study analyzing associations between preferred substance and various behavioral and health outcomes amongst people who use both heroin and methamphetamine, a majority of participants preferred heroin. Methamphetamine preference was associated with lower prevalence of naloxone possession, ever being told they had HCV, and prior history of an overdose. This study underscores the need for targeted harm reduction services for people who prefer methamphetamine in rural areas.

Barriers to retention in inpatient and residential drug treatment among persons who use opioids and/or injection drugs living in the rural U.S.

AIM: Barriers to retention in inpatient and residential care for persons who use drugs are understudied in the rural context. We sought to better understand barriers to retention in inpatient and residential drug treatment in a large, multi-site, geographically diverse sample of persons who use opioids and/or injection drugs in the rural U.S. METHODS: We conducted semi-structured individual interviews with persons currently using opioids and/or injection drugs in 9 U.S. states, including Illinois, Kentucky, Massachusetts, North Carolina, New Hampshire, Ohio, Oregon, Vermont, and Wisconsin. Content areas included substance use history and experiences with all modalities of drug treatment. We performed initial structural coding followed by an iterative "open-coding" process of itemizing and categorizing content within each code, and a multi-coder memoing process to summarize themes. We identified themes using three levels of the Social-Ecological Model (SEM): individual, interpersonal, and facility-level (organizational) barriers. RESULTS: Among 304 interviewed, over half (n = 166, 54 %) reported having experienced inpatient and residential treatment. Lack of treatment retention was driven by interrelated factors at all levels of the SEM. Person-level factors inhibiting retention included lack of readiness to stop using, which was particularly true for court-ordered treatment, and dislike of "freedom limitations". The sole interpersonal-level factor was the influence of other patients on re-initiation of drug use. Facility-level barriers included unaddressed withdrawal symptoms and lack of access to MOUD, staff relatability, inadequate staff training, and, particularly in residential treatment, lack of structure and supervision. Lack of preparation for coping with real-world triggers was seen as a barrier to engagement in ongoing treatment. CONCLUSION: Barriers to retention in inpatient and residential substance use treatment were present at three levels of the SEM. Interviews suggest much room for improvement in inpatient and residential drug treatment programs with respect to improving access to MOUD, tailoring content to better address social challenges in the rural context, and improving quality control measures with respect to staff and resident supervision.

Correlates of Intimate Partner Violence, Including Psychological Partner Violence, in a Multisite U.S. Cohort of People in HIV Care.

We examined past-year intimate partner violence (IPV), including psychological violence without physical/sexual violence, and health outcomes among people with HIV (PWH) in care in a multi-site U.S. cohort. Between 2016 and 2022, PWH reported 12-month psychological, physical, and sexual IPV in a routine assessment. We used linear and logistic regression models adjusted for age, race/ethnicity, and site to examine relationships with health outcomes. Among 9748 PWH (median age 50 years, 81% cisgender male/16% cisgender female/1% transgender female; 44% non-Hispanic white/36% non-Hispanic Black/15% Hispanic), 9.3% (n = 905) reported any IPV in the past 12 months; half reported psychological IPV without physical/sexual IPV (n = 453). PWH reporting any type of IPV were on average younger than those who did not experience IPV. In adjusted models, any IPV was associated with increased likelihood of unstable housing, HIV viral load detection (HIV viral load ≥ 75 copies/mL), moderate-to-severe depressive symptoms, anxiety with panic symptoms, substance use (methamphetamines, cocaine/crack, illicit opioids, marijuana, heavy episodic/hazardous drinking), and concern about exposure to sexually transmitted infection. PWH reporting any IPV in the past 12 months had 4.2% lower adherence to antiretroviral therapy, 2.4 more HIV-related symptoms, a 1.9 point higher HIV stigma score, and a 9.5% lower quality of life score than those without IPV. We found similar associations among PWH reporting only psychological IPV, without physical/sexual IPV. IPV was common among PWH. Half reporting IPV reported only psychological IPV and had similarly poor outcomes as those reporting physical/sexual IPV, demonstrating the need to assess psychological as well as physical and sexual IPV.

RESUMEN: Examinamos la violencia de la pareja íntima (intimate partner violence, IPV) del año anterior, incluida la violencia psicológica sin violencia física y sexual, así como los resultados sanitarios entre las personas con VIH (people with HIV, PWH) que reciben atención en una cohorte multicéntrica de los Estados Unidos. Entre 2016 y 2022, las PWH informaron situaciones de IPV psicológica, física y sexual durante los 12 meses en una evaluación de rutina. Se utilizaron modelos de regresión lineal y logística ajustados por edad, raza/etnia y centro para examinar las relaciones con los resultados sanitarios. Entre 9748 PWH (mediana de edad de 50 años, 81% de hombres cisgénero/16% de mujeres cisgénero/1% de mujeres transgénero; 44% de blancos no hispanos/36% de negros no hispanos/15% de hispanos), el 9,3% (n = 905) informaron haber sufrido algún tipo de IPV en los últimos 12 meses; la mitad informó situaciones de IPV psicológica sin IPV física y sexual (n = 453). Las PWH que informaron de cualquier tipo de IPV fueron, en promedio, más jóvenes que las que no sufrieron IPV. En los modelos ajustados, cualquier IPV se asoció con una mayor probabilidad de vivienda inestable, detección de carga viral del VIH (carga viral del VIH ≥ 75 copias/ml), síntomas depresivos de moderados a graves, ansiedad con síntomas de pánico, consumo de sustancias (metanfetaminas, cocaína/crack, opioides ilícitos, marihuana, consumo excesivo episódico/peligroso de alcohol) y preocupación por la exposición a infecciones de transmisión sexual. Las PWH que informaron alguna situación de IPV en los últimos 12 meses tuvieron un 4,2% menos de cumplimiento de la terapia antirretrovírica, un 2,4% más de síntomas relacionados con el VIH, una puntuación de estigma del VIH 1,9 puntos más alta y una puntuación de calidad de vida un 9,5% más baja que las que no sufrieron IPV. Se encontraron asociaciones similares entre las PWH que informaron solo IPV psicológica, sin IPV física y sexual. La IPV fue común entre las PWH. La mitad de las personas que informaron IPV solo informaron IPV psicológica y tuvieron resultados igualmente deficientes que los que informaron IPV física y sexual, lo que demuestra la necesidad de evaluar la IPV psicológica, al igual que la IPV física y sexual.

Motivation and context of concurrent stimulant and opioid use among persons who use drugs in the rural United States: a multi-site qualitative inquiry.

BACKGROUND: In recent years, stimulant use has increased among persons who use opioids in the rural U.S., leading to high rates of overdose and death. We sought to understand motivations and contexts for stimulant use among persons who use opioids in a large, geographically diverse sample of persons who use drugs (PWUD) in the rural settings. METHODS: We conducted semi-structured individual interviews with PWUD at 8 U.S. sites spanning 10 states and 65 counties. Content areas included general substance use, injection drug use, changes in drug use, and harm reduction practices. We used an iterative open-coding process to comprehensively itemize and categorize content shared by participants related to concurrent use. RESULTS: We interviewed 349 PWUD (64% male, mean age 36). Of those discussing current use of stimulants in the context of opioid use (n = 137, 39%), the stimulant most used was methamphetamine (78%) followed by cocaine/crack (26%). Motivations for co-use included: 1) change in drug markets and cost considerations; 2) recreational goals, e.g., seeking stronger effects after heightened opioid tolerance; 3) practical goals, such as a desire to balance or alleviate the effects of the other drug, including the use of stimulants to avoid/reverse opioid overdose, and/or control symptoms of opioid withdrawal; and 4) functional goals, such as being simultaneously energized and pain-free in order to remain productive for employment. CONCLUSION: In a rural U.S. cohort of PWUD, use of both stimulants and opioids was highly prevalent. Reasons for dual use found in the rural context compared to urban studies included changes in drug availability, functional/productivity goals, and the use of methamphetamine to offset opioid overdose. Education efforts and harm reduction services and treatment, such as access to naloxone, fentanyl test strips, and accessible drug treatment for combined opioid and stimulant use, are urgently needed in the rural U.S. to reduce overdose and other adverse outcomes.

Barriers to opioid use disorder treatment among people who use drugs in the rural United States: A qualitative, multi-site study.

BACKGROUND: In 2020, 2.8 million people required substance use disorder (SUD) treatment in nonmetropolitan or 'rural' areas in the U.S. Among this population, only 10% received SUD treatment from a specialty facility, and 1 in 500 received medication for opioid use disorder (MOUD). We explored the context surrounding barriers to SUD treatment in the rural United States. METHODS: We conducted semi-structured, in-depth interviews from 2018 to 2019 to assess barriers to SUD treatment among people who use drugs (PWUD) across seven rural U.S. study sites. Using the social-ecological model (SEM), we examined individual, interpersonal, organizational, community, and policy factors contributing to perceived barriers to SUD treatment. We employed deductive and inductive coding and analytical approaches to identify themes. We also calculated descriptive statistics for participant characteristics and salient themes. RESULTS: Among 304 participants (55% male, mean age 36 years), we identified barriers to SUD treatment in rural areas across SEM levels. At the individual/interpersonal level, relevant themes included: fear of withdrawal, the need to "get things in order" before entering treatment, close-knit communities and limited confidentiality, networks and settings that perpetuated drug use, and stigma. Organizational-level barriers included: strict facility rules, treatment programs managed like corrections facilities, lack of gender-specific treatment programs, and concerns about jeopardizing employment. Community-level barriers included: limited availability of treatment in local rural communities, long distances and limited transportation, waitlists, and a lack of information about treatment options. Policy-level themes included insurance challenges and system-imposed barriers such as arrest and incarceration. CONCLUSION: Our findings highlight multi-level barriers to SUD treatment in rural U.S. communities. Salient barriers included the need to travel long distances to treatment, challenges to confidentiality due to small, close-knit communities where people are highly familiar with one another, and high-threshold treatment program practices. Our findings point to the need to facilitate the elimination of treatment barriers at each level of the SEM in rural America.

Differences in internalized HIV stigma across subpopulations of people with HIV in care across the United States.

BACKGROUND: Few studies have examined which subgroups of people with HIV (PWH) carry the greatest burden of internalized HIV stigma (IHS), which may be important to care provision and interventions. METHODS: PWH in the CFAR Network of Integrated Clinical Systems (CNICS) longitudinal, US-based, multisite, clinical care cohort completed tablet-based assessments during clinic visits including a four-item, Likert scale (low 1-5 high), IHS instrument. Associations between sociodemographic characteristics and IHS scores were assessed in adjusted linear regression models. RESULTS: Twelve thousand six hundred and fifty-six PWH completed the IHS assessment at least once from February 2016 to November 2022, providing 28 559 IHS assessments. At baseline IHS assessment, the mean age was 49 years, 41% reported White, 38% Black/African American, and 16% Latine race/ethnicity, and 80% were cisgender men. The mean IHS score was 2.04, with all subgroups represented among those endorsing IHS. In regression analyses, younger PWH and those in care fewer years had higher IHS scores. In addition, cisgender women vs. cisgender men, PWH residing in the West vs. the Southeast, and those with sexual identities other than gay/lesbian had higher IHS scores. Compared with White-identifying PWH, those who identified with Black/African American or Latine race/ethnicity had lower IHS scores. Age stratification revealed patterns related to age category, including specific age-related differences by gender, geographic region and race/ethnicity. DISCUSSION: IHS is prevalent among PWH, with differential burden by subgroups of PWH. These findings highlight the benefits of routine screening for IHS and suggest the need for targeting/tailoring interventions to reduce IHS among PWH.

Weight loss associated with semaglutide treatment among people with HIV.

OBJECTIVE: There is limited real-world evidence about the effectiveness of semaglutide for weight loss among people with HIV (PWH). We aimed to investigate weight change in a US cohort of PWH who initiated semaglutide treatment. DESIGN: Observational study using the Centers for AIDS Research Network of Integrated Clinical Systems (CNICS) cohort. METHODS: We identified adult PWH who initiated semaglutide between 2018 and 2022 and with at least two weight measurements. The primary outcome was within-person bodyweight change in kilograms at 1 year. The secondary outcome was within-person Hemoglobin A1c percentage (HbA1c) change. Both outcomes were estimated using multivariable linear mixed model. RESULTS: In total, 222 new users of semaglutide met inclusion criteria. Mean follow-up was 1.1 years. Approximately 75% of new semaglutide users were men, and at baseline, mean age was 53 years [standard deviation (SD): 10], average weight was 108 kg (SD: 23), mean BMI was 35.5 kg/m 2 , mean HbA1c was 7.7% and 77% had clinically recognized diabetes. At baseline, 97% were on ART and 89% were virally suppressed (viral load < 50 copies/ml). In the adjusted mixed model analysis, treatment with semaglutide was associated with an average weight loss of 6.47 kg at 1 year (95% CI -7.67 to -5.18) and with a reduction in HbA1c of 1.07% at 1 year (95% CI -1.64 to -0.50) among the 157 PWH with a postindex HbA1c value. CONCLUSION: Semaglutide was associated with significant weight loss and HbA1c reduction among PWH, comparable to results of previous studies from the general population.

Venous Thromboembolism Among People With HIV: Design, Implementation, and Findings of a Centralized Adjudication System in Clinical Care Sites Across the United States.

BACKGROUND: People with HIV (PWH) are at increased risk for venous thromboembolism (VTE). We conducted this study to characterize VTE including provoking factors among PWH in the current treatment era. METHODS: We included PWH with VTE between 2010 and 2020 at 6 sites in the CFAR Network of Integrated Clinical Systems cohort. We ascertained for possible VTE using diagnosis, VTE-related imaging, and VTE-related procedure codes, followed by centralized adjudication of primary data by expert physician reviewers. We evaluated sensitivity and positive predictive value of VTE ascertainment approaches. VTEs were classified by type and anatomic location. Reviewers identified provoking factors such as hospitalizations, infections, and other potential predisposing factors such as smoking. RESULTS: We identified 557 PWH with adjudicated VTE: 239 (43%) had pulmonary embolism with or without deep venous thrombosis, and 318 (57%) had deep venous thrombosis alone. Ascertainment with clinical diagnoses alone missed 6% of VTEs identified with multiple ascertainment approaches. DVTs not associated with intravenous lines were most often in the proximal lower extremities. Among PWH with VTE, common provoking factors included recent hospitalization (n = 134, 42%), infection (n = 133, 42%), and immobilization/bed rest (n = 78, 25%). Only 57 (10%) PWH had no provoking factor identified. Smoking (46%), HIV viremia (27%), and injection drug use (22%) were also common. CONCLUSIONS: We conducted a robust adjudication process that demonstrated the benefits of multiple ascertainment approaches followed by adjudication. Provoked VTEs were more common than unprovoked events. Nontraditional and modifiable potential predisposing factors such as viremia and smoking were common.

Alcohol and drug use severity are independently associated with antiretroviral adherence in the current treatment era.

Substance use in people with HIV (PWH) negatively impacts antiretroviral therapy (ART) adherence. However, less is known about this in the current treatment era and the impact of specific substances or severity of substance use. We examined the associations of alcohol, marijuana, and illicit drug use (methamphetamine/crystal, cocaine/crack, illicit opioids/heroin) and their severity of use with adherence using multivariable linear regression in adult PWH in care between 2016 and 2020 at 8 sites across the US. PWH completed assessments of alcohol use severity (AUDIT-C), drug use severity (modified ASSIST), and ART adherence (visual analogue scale). Among 9400 PWH, 16% reported current hazardous alcohol use, 31% current marijuana use, and 15% current use of ≥1 illicit drugs. In multivariable analysis, current methamphetamine/crystal use, particularly common among men who had sex with men, was associated with 10.1% lower mean ART adherence (p < 0.001) and 2.6% lower adherence per 5-point higher severity of use (ASSIST score) (p < 0.001). Current and more severe use of alcohol, marijuana, and other illicit drugs were also associated with lower adherence in a dose-dependent manner. In the current HIV treatment era, individualized substance use treatment, especially for methamphetamine/crystal, and ART adherence should be prioritized.

Evaluating the Sick Quitting Hypothesis for Frailty Status and Reducing Alcohol Use Among People With HIV in a Longitudinal Clinical Cohort Study.

ABSTRACT: "Sick quitting," a phenomenon describing reductions in alcohol consumption following poor health, may explain observations that alcohol appears protective for frailty risk. We examined associations between frailty and reductions in drinking frequency among people with HIV (PWH). At six Centers for AIDS Research Network of Integrated Clinical Systems (CNICS) sites between January 2012 and August 2021, we assessed whether frailty, measured through validated modified frailty phenotype, precedes reductions in drinking frequency. We associated time-updated frailty with quitting and reducing frequency of any drinking and heavy episodic drinking (HED), adjusted for demographic and clinical characteristics in Cox models. Among 5,654 PWH reporting drinking, 60% reported >monthly drinking and 18% reported ≥monthly HED. Over an average of 5.4 years, frail PWH had greater probabilities of quitting (HR: 1.56, 95% confidence interval [95% CI] [1.13-2.15]) and reducing (HR: 1.35, 95% CI [1.13-1.62]) drinking frequency, as well as reducing HED frequency (HR: 1.58, 95% CI [1.20-2.09]) versus robust PWH. Sick quitting likely confounds the association between alcohol use and frailty risk, requiring investigation for control.

Methamphetamine use and utilization of medications for opioid use disorder among rural people who use drugs.

BACKGROUND: Methamphetamine use is common among persons with opioid use disorder. This study evaluated associations between methamphetamine use and treatment with agonist medications for opioid use disorder (MOUD, specifically buprenorphine, and/or methadone) in U.S. rural communities. METHODS: The Rural Opioid Initiative (ROI) is a consortium spanning 10 states and 65 rural counties that included persons who reported past 30-day use of opioids and/or injection drug use between 1/2018 and 3/2020. Analyses were restricted to participants who had ever used opioids and had data on past 30-day methamphetamine use. Multivariable models examined the relationship between methamphetamine use and utilization of agonist MOUD. RESULTS: Among 2899 participants, 2179 (75.2%) also reported recent methamphetamine use. Persons with methamphetamine use compared to those without were younger, more likely to have injected drugs, be unhoused, criminal justice involved, and less likely to have health insurance. Adjusted for age, sex, race, and study site, recent methamphetamine use was associated with lower relative odds of past 30-day methadone treatment (aOR=0.66; 95% CI: 0.45-0.99) and fewer methadone treatment days (aIRR=0.76; 0.57-0.99), but not past 30-day buprenorphine receipt (aOR=0.90; 0.67-1.20), buprenorphine treatment days in past 6 months: aIRR=0.88; 0.69-1.12) or perceived inability to access buprenorphine (aOR=1.12; 0.87-1.44) or methadone (aOR=1.06; 0.76-1.48). CONCLUSION: Methamphetamine use is common among persons who use opioids in rural U.S. areas and negatively associated with current treatment and retention on methadone but not buprenorphine. Future studies should examine reasons for this disparity and reduce barriers to methadone for persons who use opioids and methamphetamine.

Validity Properties of a Self-reported Modified Frailty Phenotype Among People With HIV in Clinical Care in the United States.

ABSTRACT: Modifications to Fried's frailty phenotype (FFP) are common. We evaluated a self-reported modified frailty phenotype (Mod-FP) used among people with HIV (PWH). Among 522 PWH engaged in two longitudinal studies, we assessed validity of the four-item Mod-FP compared with the five-item FFP. We compared the phenotypes via receiver operator characteristic curves, agreement in classifying frailty, and criterion validity via association with having experienced falls. Mod-FP classified 8% of PWH as frail, whereas FFP classified 9%. The area under the receiver operator characteristic curve for Mod-FP classifying frailty was 0.93 (95% CI = 0.91-0.96). We observed kappa ranging from 0.64 (unweighted) to 0.75 (weighted) for categorizing frailty status. Both definitions found frailty associated with a greater odds of experiencing a fall; FFP estimated a slightly greater magnitude (i.e., OR) for the association than Mod-FP. The Mod-FP has good performance in measuring frailty among PWH and is reasonable to use when the gold standards of observed assessments (i.e., weakness and slowness) are not feasible.

Short-term metabolic effects of prednisone administration in healthy subjects.

AIMS: Supraphysiologic glucocorticoid activity is well established to cause impaired glucose tolerance and insulin resistance, yet no study has evaluated dose-dependent effects of low-dose prednisone during short-term oral administration. METHODS: The objective of this study was to quantify the effects of daily 10 or 25 mg prednisone administration for one week on insulin sensitivity by employing a two-step hyperinsulinemic euglycemic glucose clamp (Step 1: insulin infusion = 20 mU/m²/min; Step 2: insulin infusion = 80 mU/m²/min) in healthy, lean males. The amount of glucose infused at steady-state to maintain stable blood glucose [90 mg/dl (4.95 mmol/l)] was used to calculate several indices of insulin sensitivity. RESULTS: During Step 1 of the clamp, whole body glucose disposal (M) was reduced by 35% (p = 0.003) and M/I was reduced by 29% (p = 0.025) for 25 mg prednisone compared to placebo. No appreciable effect of 10 mg prednisone was observed. During Step 2, M was reduced by 33% (p = 0.001) and 15% (p = 0.006) for 25 and 10 mg prednisone compared to placebo; and M/I ratio was reduced by 31% (p < 0.001) and 13% (p = 0.026), respectively. The insulin sensitivity index, Si, calculated as the quotient of augmentation of M/I between Step 1 and 2, was reduced by 35.3% (p < 0.01) and 23.5% (p < 0.05) for 25 and 10 mg prednisone, respectively. CONCLUSION: Administration of relatively low pharmacological doses of prednisone for one week impaired insulin sensitivity in a dose-dependent manner in healthy males. These observed changes in insulin sensitivity are likely to be clinically relevant, especially in individuals predisposed to develop glucose intolerance.

Cardiovascular monkey telemetry: sensitivity to detect QT interval prolongation.

INTRODUCTION: Preclinical evaluation of delayed ventricular repolarization manifests electrocardiographically as QT interval prolongation and is routinely used as an indicator of potential risk for pro-arrhythmia (potential to cause Torsades de Pointes) of novel human pharmaceuticals. In accordance with ICH S7A and S7B guidelines we evaluated the sensitivity and validity of the monkey telemetry model as a preclinical predictor of QT interval prolongation in humans. METHODS: Cardiovascular monitoring was conducted for 2 h pre-dose and 24 h post-dosing with Moxifloxacin (MOX), with a toxicokinetic (TK) evaluation in a separate group of monkeys. In both studies, MOX was administered orally by gavage in 0.5% methylcellulose at 0, 10, 30, 100, 175 mg/kg. Each monkey received all 5 doses using a dose-escalation paradigm. Inherent variability of the model was assessed with administration of vehicle alone for 4 days in all 4 monkeys (0.5% methylcellulose in deionized water). RESULTS: MOX had no significant effect on mean arterial pressure, heart rate, PR or QRS intervals. MOX produced significant dose-related increases in QTc at doses of 30 (Cmax=5.5+/-0.6 microM), 100 (Cmax=16.5+/-1.6 microM), and 175 (Cmax=17.3+/-0.7 microM) mg/kg with peak increases of 22 (8%), 27 (10%), and 47 (18%) ms, respectively (p

Adaptation of the WHO guideline for residual DNA in parenteral vaccines produced on continuous cell lines to a limit for oral vaccines.

Although there is a WHO guidance for a limit on residual DNA for parenterally administered vaccines produced on continuous cell lines, there is no corresponding guidance for oral vaccines. To help determine an oral limit, we performed a study of Vero cell DNA uptake in rats, in which the relative uptake and persistence of Vero cell DNA administered orally was compared to its uptake when delivered intramuscularly (IM). The results of this study allowed the generation of an empirically derived IM versus oral factor (10(6)) representing the relative inefficiency of DNA uptake by oral administration. This factor was then applied to the WHO recommended parenteral limit of 10 ng/dose to determine a corresponding upper limit on the level of residual Vero cell DNA for an oral vaccine of 10 mg. As a conservative approach, this empirically determined limit was reduced 100-fold to 100 microg. Thus, the results of this animal study, together with additional evidence in the literature, support a residual DNA safety limit of 100 microg per dose for an oral vaccine produced on a continuous cell line.

In vitro activity of ertapenem against common clinical isolates in relation to human pharmacokinetics.

The in vitro activity of ertapenem against bacterial pathogens isolated from patients with moderate to severe complicated intra-abdominal, complicated skin/skin structure, acute pelvic, or complicated urinary tract infection or community acquired pneumonia was compared to ceftriaxone and piperacillin-tazobactam and related to known plasma concentrations of the three agents. Ertapenem was more potent against methicillin-susceptible Staphylococcus aureus (MSSA) than ceftriaxone and piperacillin-tazobactam and was more potent and more active than both of these agents against Enterobacteriaceae and anaerobes. Piperacillin-tazobactam was the most active agent against enterococci and Pseudomonas aeruginosa. All isolates of Enterobacteriaceae (n=1088), Streptococcus pyogenes (n=37), Streptococcus agalactiae (n=48), MSSA (n=187), Haemophilus influenzae (n=59), and Moraxella catarrhalis (n=9) were susceptible to ertapenem; < 1% of 1284 anaerobes and only 1 of 113 Streptococcus pneumoniae (a penicillin-resistant isolate) were resistant to ertapenem. The MIC value at which 90% of all Enterobacteriaceae, streptococci, MSSA, H. influenzae, M. catarrhalis, and anaerobes were inhibited (MIC90) was < or = 1 microg/ml and below the mean plasma concentration of total ertapenem following a 1 g intravenous infusion for at least 24 hours, i.e., the entire recommended dosing interval, and below the free drug concentration for at least 8 h.

P53+/- hemizygous knockout mouse: overview of available data.

The performance of the p53-/- transgenic (knockout) mouse model was evaluated through review of the data from 31 short-term carcinogenicity studies with 21 compounds tested as part of the International Life Sciences Institute's (ILSI) Alternatives to Carcinogenicity Testing (ACT) project, together with data from other studies which used comparable protocols. As expected based on the hypothesis for the model, a significant number (12/16 or 75%) of the genotoxic human and/or rodent carcinogens tested were positive and the positive control, p-cresidine, gave reproducible responses across laboratories (18/19 studies positive in bladder). An immunosuppressive human carcinogen, cyclosporin A, was positive for lymphomas but produced a similar response in wild type mice. Two hormones that are human tumorigens, diethylstilbestrol and 17beta-estradiol, gave positive and equivocal results, respectively, in the pituitary with p53-deficient mice showing a greater incidence of proliferative lesions than wild type. None of the 22 nongenotoxic rodent carcinogens that have been tested produced a positive response but 2 compounds in this category, chloroform and diethylhexylphthalate, were judged equivocal based on effects in liver and kidney respectively. Four genotoxic noncarcinogens and 6 nongenotoxic, noncarcinogens were also negative. In total (excluding compounds with equivocal results), 42 of 48 compounds or 88% gave results that were concordant with expectations. The technical lessons learned from the ILSI ACT-sponsored testing in the p53+/- model are discussed.

In vitro activities of ertapenem (MK-0826) against recent clinical bacteria collected in Europe and Australia.

Ertapenem (MK-0826, L-749,345) is a 1-beta-methyl carbapenem with a long serum half-life. Its in vitro activity was determined by broth microdilution against 3,478 bacteria from 12 centers in Europe and Australia, with imipenem, cefepime, ceftriaxone, and piperacillin-tazobactam used as comparators. Ertapenem was the most active agent tested against members of the family Enterobacteriaceae, with MICs at which 90% of isolates are inhibited (MIC(90)s) of < or =1 microg/ml for all species. Ertapenem also was more active than imipenem against fastidious gram-negative bacteria and Moraxella spp.; on the other hand, ertapenem was slightly less active than imipenem against streptococci, methicillin-susceptible staphylococci, and anaerobes, but its MIC(90)s for these groups remained < or =0.5 microg/ml. Acinetobacter spp. and Pseudomonas aeruginosa were also much less susceptible to ertapenem than imipenem, and most Enterococcus faecalis strains were resistant. Ertapenem resistance, based on a provisional NCCLS MIC breakpoint of > or =16 microg/ml, was seen in only 3 of 1,611 strains of the family Enterobacteriaceae tested, all of them Enterobacter aerogenes. Resistance was also seen in 2 of 135 anaerobes, comprising 1 Bacteroides fragilis strain and 1 Clostridium difficile strain. Ertapenem breakpoints for streptococci have not been established, but an unofficial susceptibility breakpoint of < or =2 microg/ml was adopted for clinical trials to generate corresponding clinical response data for isolates for which MICs were as high as 2 microg/ml. Of 234 Streptococcus pneumoniae strains tested, 2 required ertapenem MICs of 2 microg/ml and one required an MIC of 4 microg/ml, among 67 non-Streptococcus pyogenes, non-Streptococcus pneumoniae streptococci, single isolates required ertapenem MICs of 2 and 16 microg/ml. These streptococci also had diminished susceptibilities to other beta-lactams, including imipenem as well as ertapenem. The Etest and disk diffusion gave susceptibility test results in good agreement with those of the broth microdilution method for ertapenem.

Mapping of hKCa3 to chromosome 1q21 and investigation of linkage of CAG repeat polymorphism to schizophrenia.

CAG trinucleotide polymorphisms in the neuronal small conductance calcium-activated potassium channel gene hKCa3 have been reported to be associated with schizophrenia. Attempts to confirm this finding have met with mixed results. We investigated hKCa3 CAG allele lengths in families from the National Institute of Mental Health (NIMH) Schizophrenia Genetics Initiative, by comparing transmission to discordant siblings and parental transmission to affected offspring. Overall, there was no convincing evidence that hKCa3 CAG lengths differ between schizophrenics and controls. We did, however, observe a trend (P = 0.063) toward over-representation of long (> or = 19) CAG repeats in the shorter of the two hKCa3 alleles in schizophrenics. There was no evidence of excessive parental transmission of long CAG repeat alleles to affected offspring. In addition, we re-mapped hKCa3 and found that it resides on chromosome 1q21, in a region which has been linked to familial hemiplegic migraine, but not to schizophrenia. These data provide no significant support for the association of hKCa3 with schizophrenia.