Project CHARIOT: study protocol for a hybrid type 1 effectiveness-implementation study of comprehensive tele-harm reduction for engagement of people who inject drugs in HIV prevention services

BACKGROUND

People who inject drugs (PWID) remain a high priority population under the federal Ending the HIV Epidemic initiative with 11% of new HIV infections attributable to injection drug use. There is a critical need for innovative, efficacious, scalable, and community-driven models of healthcare in non-stigmatizing settings for PWID. We seek to test a Comprehensive-TeleHarm Reduction (C-THR) intervention for HIV prevention services delivered via a syringe services program (SSP).

METHODS

The CHARIOT trial is a hybrid type I effectiveness-implementation study using a parallel two-arm randomized controlled trial design. Participants (i.e., PWID; n = 350) will be recruited from a syringe services program (SSP) in Miami, Florida. Participants will be randomized to receive either C-THR or non-SSP clinic referral and patient navigation. The objectives are: (1) to determine if the C-THR intervention increases engagement in HIV prevention (i.e., HIV pre-exposure prophylaxis; PrEP or medications for opioid use disorder; MOUD) compared to non-SSP clinic referral and patient navigation, (2) to examine the long-term effectiveness and cost-effectiveness of the C-THR intervention, and (3) to assess the barriers and facilitators to implementation and sustainment of the C-THR intervention. The co-primary outcomes are PrEP or MOUD engagement across follow-up at 3, 6, 9 and 12 months. For PrEP, engagement is confirmed by tenofovir on dried blood spot or cabotegravir injection within the previous 8 weeks. For MOUD, engagement is defined as screening positive for norbuprenorphine or methadone on urine drug screen; or naltrexone or buprenorphine injection within the previous 4 weeks. Secondary outcomes include PrEP adherence, engagement in HCV treatment and sustained virologic response, and treatment of sexually transmitted infections. The short and long term cost-effectiveness analyses and mixed-methods implementation evaluation will provide compelling data on the sustainability and possible impact of C-THR on comprehensive HIV prevention delivered via SSPs.

DISCUSSION

The CHARIOT trial will be the first to our knowledge to test the efficacy of an innovative, peer-led telehealth intervention with PWID at risk for HIV delivered via an SSP. This innovative healthcare model seeks to transform the way PWID access care by bypassing the traditional healthcare system, reducing multi-level barriers to care, and meeting PWID where they are.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05897099. Trial registry name: Comprehensive HIV and Harm Prevention Via Telehealth (CHARIOT). Registration date: 06/12/2023.

Improving access to HIV care among people who inject drugs through tele-harm reduction: a qualitative analysis of perceived discrimination and stigma

BACKGROUND

Tele-harm reduction (THR) is a telehealth-enhanced, peer-led, harm reduction intervention delivered within a trusted syringe services program (SSP) venue. The primary goal of THR is to facilitate linkage to care and rapid, enduring virologic suppression among people who inject drugs (PWID) with HIV. An SSP in Miami, Florida, developed THR to circumvent pervasive stigma within the traditional healthcare system.

METHODS

During intervention development, we conducted in-depth interviews with PWID with HIV (n = 25) to identify barriers and facilitators to care via THR. We employed a general inductive approach to transcripts guided by iterative readings of the raw data to derive the concepts, themes, and interpretations of the THR intervention.

RESULTS

Of the 25 PWID interviewed, 15 were in HIV care and adherent to medication; 4 were in HIV care but non-adherent; and 6 were not in care. Themes that emerged from the qualitative analysis included the trust and confidence PWID have with SSP clinicians as opposed to professionals within the traditional healthcare system. Several barriers to treatment were reported among PWID, including perceived and actual discrimination by friends and family, negative internalized behaviors, denial of HIV status, and fear of engaging in care. Facilitators to HIV care included empathy and respect by SSP staff, flexibility of telehealth location, and an overall destigmatizing approach.

CONCLUSION

PWID identified barriers and facilitators to receipt of HIV care through the THR intervention. Interviews helped inform THR intervention development, centered on PWID in the destigmatizing environment of an SSP.

Transcranial static magnetic stimulation reduces seizures in a mouse model of Dravet syndrome

Dravet syndrome is a rare form of severe genetic epilepsy characterized by recurrent and long-lasting seizures. It appears around the first year of life, with a quick evolution toward an increase in the frequency of the seizures, accompanied by a delay in motor and cognitive development, and does not respond well to antiepileptic medication. Most patients carry a mutation in the gene SCN1A encoding the α subunit of the voltage-gated sodium channel Nav1.1, resulting in hyperexcitability of neural circuits and seizure onset. In this work, we applied transcranial static magnetic stimulation (tSMS), a non-invasive, safe, easy-to-use and affordable neuromodulatory tool that reduces neural excitability in a mouse model of Dravet syndrome. We demonstrate that tSMS dramatically reduced the number of crises. Furthermore, crises recorded in the presence of the tSMS were shorter and less intense than in the sham condition. Since tSMS has demonstrated its efficacy at reducing cortical excitability in humans without showing unwanted side effects, in an attempt to anticipate a possible use of tSMS for Dravet Syndrome patients, we performed a numerical simulation in which the magnetic field generated by the magnet was modeled to estimate the magnetic field intensity reached in the cerebral cortex, which could help to design stimulation strategies in these patients. Our results provide a proof of concept for nonpharmacological treatment of Dravet syndrome, which opens the door to the design of new protocols for treatment.

Prevalence of xylazine among people who inject drugs seeking medical care at a syringe services program clinic: Miami, Florida, 2023

Background

We aimed to report the preliminary xylazine prevalence among people who inject drugs (PWID) treated at a student-run free clinic in Miami, FL, USA and to identify characteristics associated with screening positive for xylazine.

Methods

A retrospective chart review of 59 patients presenting to a syringe services program (SSP) clinic in was conducted between April 27th and August 17th, 2023. We measured presence of xylazine with rapid visual immunoassay strips on patient urine samples.

Results

Xylazine was present in 55.9 % (33/59) of urine samples including 2 without detected opioids. Xylazine presence was significantly associated with unsheltered homelessness (p = 0.018), presence of wound(s) (p = 0.008), and testing positive for hepatitis C antibody (p = 0.014), fentanyl (p = 0.005) and MDMA (p = 0.002).

Conclusions

A high prevalence of xylazine in the Southeastern United States furthers evidence of the geographical spread of xylazine and rapidly evolving illicit drug supply. Widespread xylazine screening is urgently needed to inform people who inject drugs and to studyinterventions to minimize harms associated with xylazine.

Adaptation of the Tele-Harm Reduction intervention to promote initiation and retention in buprenorphine treatment among people who inject drugs: a retrospective cohort study

Background: At the start of the pandemic, relaxation of buprenorphine prescribing regulations created an opportunity to create new models of medications for opioid use disorder (MOUD) delivery and care. To expand and improve access to MOUD, we adapted and implemented the Tele-Harm Reduction (THR) intervention; a multicomponent, telehealth-based and peer-driven intervention to promote HIV viral suppression among people who inject drugs (PWID) accessing a syringe services program (SSP). This study examined buprenorphine initiation and retention among PWID with opioid use disorder who received the adapted THR intervention at the IDEA Miami SSP.Methods: A retrospective chart review of participants who received the THR intervention for MOUD was performed to examine the impact of telehealth on buprenorphine retention. Our primary outcome was three-month retention, defined as three consecutive months of buprenorphine dispensed from the pharmacy.Results: A total of 109 participants received the adapted THR intervention. Three-month retention rate on buprenorphine was 58.7%. Seeing a provider via telehealth at baseline or any follow up visit (aOR = 7.53, 95% CI: [2.36, 23.98]) and participants who had received an escalating dose of buprenorphine after baseline visit (aOR = 8.09, 95% CI: [1.83, 35.87]) had a higher adjusted odds of retention at three months. Participants who self-reported or tested positive for a stimulant (methamphetamine, amphetamine, or cocaine) at baseline had a lower adjusted odds of retention on buprenorphine at three months (aOR = 0.29, 95% CI: [0.09, 0.93]).Conclusions: Harm reduction settings can adapt dynamically to the needs of PWID in provision of critical lifesaving buprenorphine in a truly destigmatising approach. Our pilot suggests that an SSP may be an acceptable and feasible venue for delivery of THR to increase uptake of buprenorphine by PWID and promote retention in care.KEY MESSAGESThe Tele-Harm Reduction intervention can be adapted for initiating and retaining people who inject drugs with opioid use disorder on buprenorphine within a syringe services program settingUsing telehealth was associated with increased three-month buprenorphine retentionBaseline stimulant use was negatively associated with three-month buprenorphine retention.

Project T-SHARP: study protocol for a multi-site randomized controlled trial of tele-harm reduction for people with HIV who inject drugs

BACKGROUND

The resurgence of HIV outbreaks and rising prevalence among people who inject drugs (PWID) remain exigent obstacles to Ending the HIV Epidemic in the USA. Adapting a low threshold, comprehensive treatment model for PWID with HIV can leverage syringe services programs (SSPs) to increase availability and accessibility of antiretrovirals (ART), medications for opioid use disorder (MOUD), and hepatitis C cure. We developed Tele-Harm Reduction, a telehealth-enhanced, harm reduction intervention delivered within an SSP venue.

METHODS

The T-SHARP trial is an open-label, multi-site, randomized controlled superiority trial with two parallel treatment arms. Participants (n=240) recruited from SSPs in Miami, Ft. Lauderdale, and Tampa, Florida, who are PWID with uncontrolled HIV (i.e., HIV RNA>200) will be randomized to Tele-Harm Reduction or off-site linkage to HIV care. The primary objective is to compare the efficacy of Tele-Harm Reduction for initiation of ART at SSPs vs. off-site linkage to an HIV clinic with respect to viral suppression across follow-up (suppression at 3, 6, and 12 months post randomization). Participants with HIV RNA<200 copies/ml will be considered virally suppressed. The primary trial outcome is time-averaged HIV viral suppression (HIV RNA <200 copies/ml) over 3-, 6-, and 12-month follow-up. Secondary outcomes include initiation of MOUD measured by urine drug screen and HCV cure, defined as achieving 12-week sustained virologic response (negative HCV RNA at 12 weeks post treatment completion). A cost-effectiveness analysis will be performed.

DISCUSSION

The T-SHARP Trial will be the first to our knowledge to test the efficacy of an innovative telehealth intervention with PWID with uncontrolled HIV delivered via an SSP to support HIV viral suppression. Tele-Harm Reduction is further facilitated by a peer to support adherence and bridge the digital divide. This innovative, flipped healthcare model sets aside the traditional healthcare system, reduces multi-level barriers to care, and meets PWID where they are. The T-SHARP trial is a pragmatic clinical trial that seeks to transform the way that PWID access HIV care and improve HIV clinical outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05208697. Trial registry name: Tele-Harm Reduction. Registration date: January 26, 2022.

Integrated Infectious Disease and Substance Use Disorder Care for the Treatment of Injection Drug Use-Associated Infections: A Prospective Cohort Study With Historical Control

Background

To address the infectious disease (ID) and substance use disorder (SUD) syndemic, we developed an integrated ID/SUD clinical team rooted in harm reduction at a county hospital in Miami, Florida. The Severe Injection-Related Infection (SIRI) team treats people who inject drugs (PWID) and provides medical care, SUD treatment, and patient navigation during hospitalization and after hospital discharge. We assessed the impact of the SIRI team on ID and SUD treatment and healthcare utilization outcomes.

Methods

We prospectively collected data on patients seen by the SIRI team. A diagnostic code algorithm confirmed by chart review was used to identify a historical control group of patients with SIRI hospitalizations in the year preceding implementation of the SIRI team. The primary outcome was death or readmission within 90 days post-hospital discharge. Secondary outcomes included initiation of medications for opioid use disorder (MOUD) and antibiotic course completion.

Results

There were 129 patients included in the study: 59 in the SIRI team intervention and 70 in the pre-SIRI team control group. SIRI team patients had a 45% risk reduction (aRR, 0.55 [95% confidence interval CI, .32-.95]; 24% vs 44%) of being readmitted in 90 days or dying compared to pre-SIRI historical controls. SIRI team patients were more likely to initiate MOUD in the hospital (93% vs 33%, P < .01), complete antibiotic treatment (90% vs 60%, P < .01), and less likely to have patient-directed discharge (17% vs 37%, P = .02).

Conclusions

An integrated ID/SUD team was associated with improvements in healthcare utilization, MOUD initiation, and antibiotic completion for PWID with infections.

1984. Implementation of an integrated infectious disease and substance use disorder team for the treatment of severe injection-related infections

Background

Hospitalizations for severe injection drug use-related infections (SIRIs) are characterized by high costs, frequent patient-directed discharge, and high readmission rates. Beyond the health system impacts, these admissions can be traumatizing to people who inject drugs (PWID), who often receive inadequate treatment for their substance use disorders (SUD). The Jackson SIRI team was developed as an integrated infectious disease/SUD treatment team for patients hospitalized at a public safety-net hospital in Miami, Florida in 2020. In order to facilitate implementation of this team, we conducted a qualitative study of patients and providers to identify barriers and facilitators to the team’s success.

Methods

Participants were patients with history of SIRIs (n=7) at the Jackson Memorial Hospital (JMH) and healthcare providers (HCPs) (n=8) at JMH. Semi-structured qualitative interviews were performed with a guide created using the Consolidated Framework for Implementation Science (CFIR). Interviews were transcribed and double coded by study team members using determinants adapted from the CFIR.

Results

Key barriers to SIRI team success included: 1) complexity of SIRI and SUD care requiring multidisciplinary teams and resources; 2) lack of resources for PWID experiencing homelessness, financial insecurity, and uninsured status; 3) stigma and lack of knowledge around addiction and medications for SUD; and 4) suspected understaffing and underfunding for the team. Facilitators of team success included: 1) holistic, integrated care being more efficient and effective than fragmented care; 2) the team’s advocacy for PWID as a means of institutional culture change; 3) provision of close post-hospital follow-up for an often-abandoned population; 4) non-judgmental, harm reduction-oriented approach; and 5) addressing diverse needs such as housing, insurance, and psychological wellbeing.

Conclusion

Integration of infectious disease and substance use disorder treatment is a promising approach to managing patients with SIRIs; however, success depends on institutional buy-in, holistic care beyond the medical domain, and an ethos rooted in harm reduction.

Disclosures

Susanne Doblecki-Lewis, MD, MSPH, Gilead Sciences: Grant/Research Support.

"We want everything in a one-stop shop": acceptability and feasibility of PrEP and buprenorphine implementation with mobile syringe services for Black people who inject drugs

INTRODUCTION

A recent surge in HIV outbreaks, driven by the opioid and stimulant use crises, has destabilized our progress toward targets set forth by Ending the HIV Epidemic: A Plan for America for the high-priority community of people who inject drugs (PWID), particularly Black PWID.

METHODS

In order to ascertain the acceptability and feasibility of using a mobile syringe services program (SSP) for comprehensive HIV prevention via PrEP and medications for opioid use disorder (MOUD), our mixed methods approach included a quantitative assessment and semi-structured qualitative interviews with Black PWID (n = 30) in Miami-Dade County who were actively engaged in mobile syringe services.

RESULTS

Participants felt that delivery of MOUD and PrEP at a mobile SSP would be both feasible and acceptable, helping to address transportation, cost, and stigma barriers common within traditional healthcare settings. Participants preferred staff who are compassionate and nonjudgmental and have lived experience.

CONCLUSIONS

A mobile harm reduction setting could be an effective venue for delivering comprehensive HIV prevention services to Black PWID, a community that experiences significant barriers to care via marginalization and racism in a fragmented healthcare system.

Harm reduction for the treatment of patients with severe injection-related infections: description of the Jackson SIRI Team

INTRODUCTION

Hospitalizations for severe injection-related infections (SIRI), such as endocarditis, osteomyelitis, and skin and soft tissue infections (SSTI) are increasingly common. People who inject drugs (PWID) experiencing SIRIs often receive inadequate substance use disorder (SUD) treatment and lack of access to harm reduction services. This translates into lengthy hospitalizations with high rates of patient-directed discharge, readmissions, and post-hospitalization mortality. The purpose of this study was to describe the development of an integrated "SIRI Team" and its initial barriers and facilitators to success.

MATERIALS AND METHODS

The Jackson SIRI Team was developed to improve both hospital and patient-level outcomes for individuals hospitalized with SIRIs at Jackson Memorial Hospital, a 1550-bed public hospital in Miami, Florida, United States. The SIRI Team provides integrated infectious disease and SUD treatment across the healthcare system starting from the inpatient setting and continuing for 90-days post-hospital discharge. The team uses a harm reduction approach, provides care coordination, focuses on access to medications for opioid use disorder (MOUD), and utilizes a variety of infection and addiction treatment modalities to suit each individual patient.

RESULTS

Over the initial 8-months of the SIRI Team, 21 patients were treated with 20 surviving until discharge. Infections included osteomyelitis, endocarditis, bacteraemia/fungemia, SSTIs, and septic arthritis. All patients had OUD and 95% used stimulants. All patients were discharged on MOUD and 95% completed their prescribed antibiotic course. At 90-days post-discharge, 25% had been readmitted and 70% reported taking MOUD.

CONCLUSIONS

A model of integrated infectious disease and SUD care for the treatment of SIRIs has the potential to improve infection and addiction outcomes. Providing attentive, patient-centered care, using a harm reduction approach can facilitate engagement of this marginalized population with the healthcare system.KEY MESSAGESIntegrated infectious disease and addiction treatment is a novel approach to treating severe injection-related infections.Harm reduction should be applied to treating patients with severe injection-related infections with a goal of facilitating antibiotic completion, remission from substance use disorder, and reducing hospital readmissions.

Recruitment into a Clinical Trial of People Living with Uncontrolled HIV Infection Who Inject Drugs: a Site Case Report from the CTN 67 CHOICES Study

CHOICES was an open-label, randomized, comparative effectiveness trial of office-based extended-release naltrexone versus treatment as usual in people with untreated opioid use disorder and HIV. This study explored facilitators to recruitment in Miami, a successful recruiting site in the national trial. The mixed-methods study included quantitative surveys of randomized participants, medical record abstraction, and qualitative interviews with study staff. Miami recruited 47 (40.5%) of 116 randomized participants in the six-site national trial. In-depth interviews of study staff (n = 6) revealed that Miami had a recruitment approach consisting of street level outreach and a close relationship with the local syringe services program (SSP). Partnership with a local SSP provided access to people living with HIV who inject drugs in Miami. SSPs' fundamental trust within the community of people who inject drugs can be leveraged in studies aiming to improve health outcomes in this underserved and high-priority population.

Rapid Identification and Investigation of an HIV Risk Network Among People Who Inject Drugs -Miami, FL, 2018

Prevention of HIV outbreaks among people who inject drugs remains a challenge to ending the HIV epidemic in the United States. The first legal syringe services program (SSP) in Florida implemented routine screening in 2018 leading to the identification of ten anonymous HIV seroconversions. The SSP collaborated with the Department of Health to conduct an epidemiologic investigation. All seven acute HIV seroconversions were linked to care (86% within 30 days) and achieved viral suppression (mean 70 days). Six of the seven individuals are epidemiologically and/or socially linked to at least two other seroconversions. Analysis of the HIV genotypes revealed that two individuals are connected molecularly at 0.5% genetic distance. We identified a risk network with complex transmission dynamics that could not be explained by epidemiological methods or molecular analyses alone. Providing wrap-around services through the SSP, including routine screening, intensive linkage and patient navigation, could be an effective model for achieving viral suppression for people who inject drugs.

Experimental display of the extended polarization coherence theorem

We report experimental results that show the interplay between visibility, distinguishability, and the degree of polarization, as ruled by a recent extension of the polarization coherence theorem (PCT). Theorems of this kind address duality in both quantum and classical scenarios. We particularly focus on the inherent vector nature of the polarization degree of freedom and display various effects that lie beyond the scope of the original PCT. Our results exhibit features that can be shared by quantum and classical phenomena, whenever these phenomena reflect some hidden or exposed coherence.

Project Kealahou: improving Hawai'i's system of care for at-risk girls and young women through gender-responsive, trauma-informed care

Project Kealahou (PK) is a six-year, federally-funded program aimed at improving services and outcomes for Hawai'i's female youth who are at risk for running away, truancy, abuse, suicide, arrest and incarceration. PK builds upon two decades of sustained cross-agency efforts among the state's mental health, juvenile justice, education, and child welfare systems to promote system-of-care (SOC) principles of community-based, individualized, culturally and linguistically competent, family driven, youth-guided, and evidence-based services. In addition, PK emphasizes trauma-informed and gender-responsive care in serving its target population of females ages 11-18 years who have experienced psychological trauma. Results from the first four years of the implementation of PK in the Department of Health's (DOH) Child and Adolescent Mental Health Division (CAMHD) highlight the serious familial, socioeconomic, functional, and interpersonal challenges faced by the young women who receive services in Hawai'i's SOC. Despite the challenges faced by PK youth and their families, preliminary results of the evaluation of PK show significant improvements across multiple clinical and functional domains of service recipients. A financial analysis indicates that these outcomes were obtained with a minimal overall increase in costs when compared to standard care alone. Overall, these results suggest that PK may offer a cost effective way to improve access, care, and outcomes for at-risk youth and their families in Hawai'i.

No time to lose--high throughput screening to assess nanomaterial safety

Nanomaterials hold great promise for medical, technological and economical benefits. Knowledge concerning the toxicological properties of these novel materials is typically lacking. At the same time, it is becoming evident that some nanomaterials could have a toxic potential in humans and the environment. Animal based systems lack the needed capacity to cope with the abundance of novel nanomaterials being produced, and thus we have to employ in vitro methods with high throughput to manage the rush logistically and use high content readouts wherever needed in order to gain more depth of information. Towards this end, high throughput screening (HTS) and high content screening (HCS) approaches can be used to speed up the safety analysis on a scale that commensurate with the rate of expansion of new materials and new properties. The insights gained from HTS/HCS should aid in our understanding of the tenets of nanomaterial hazard at biological level as well as assist the development of safe-by-design approaches. This review aims to provide a comprehensive introduction to the HTS/HCS methodology employed for safety assessment of engineered nanomaterials (ENMs), including data analysis and prediction of potentially hazardous material properties. Given the current pace of nanomaterial development, HTS/HCS is a potentially effective means of keeping up with the rapid progress in this field--we have literally no time to lose.

The prevalence of radiographic vertebral fractures in Latin American countries: the Latin American Vertebral Osteoporosis Study (LAVOS)

In the first population-based study of vertebral fractures in Latin America, we found a 11.18 (95% CI 9.23-13.4) prevalence of radiographically ascertained vertebral fractures in a random sample of 1,922 women from cities within five different countries. These figures are similar to findings from studies in Beijing, China, some regions of Europe, and slightly lower than those found in the USA using the same standardized methodology.

INTRODUCTION

We report the first study of radiographic vertebral fractures in Latin America.

METHODS

An age-stratified random sample of 1,922 women aged 50 years and older from Argentina, Brazil, Colombia, Mexico, and Puerto Rico were included. In all cases a standardized questionnaire and lateral X-rays of the lumbar and thoracic spine were obtained after informed consent.

RESULTS

A standardized prevalence of 11.18 (95% CI 9.23-13.4) was found. The prevalence was similar in all five countries, increasing from 6.9% (95% CI 4.6-9.1) in women aged 50-59 years to 27.8% (95% CI 23.1-32.4) in those 80 years and older (p for trend < 0.001). Among different risk factors, self-reported height loss OR = 1.63 (95% CI: 1.18-2.25), and previous history of fracture OR = 1.52 (95% CI: 1.14-2.03) were significantly (p < 0.003 and p < 0.04 respectably) associated with the presence of radiographic vertebral fractures in the multivariate analysis. In the bivariate analyses HRT was associated with a 35% lower risk OR = 0.65 (95% CI: 0.46-0.93) and physical activity with a 27% lower risk of having a vertebral fracture OR = 0.73 (95% CI: 0.55-0.98), but were not statistically significant in multivariate analyses

CONCLUSION

We conclude that radiographically ascertained vertebral fractures are common in Latin America. Health authorities in the region should be aware and consider implementing measures to prevent vertebral fractures.

The relation among the diameter of the great saphenous vein, clinical state and haemodynamic pattern of the saphenofemoral junction in chronic superficial venous insufficiency

OBJECTIVE

To find out if there is a relation among the diameter of the great saphenous vein (GSV) when it is incompetent, the clinical gravity of the varicose syndrome and the type of insufficiency of the saphenofemoral junction (SFJ) in patients with chronic venous insufficiency (CVI) by means of duplex exploration.

METHODS

The sample included 145 extremities, 38 normal as a control group and 107 with incompetence of the GSV. According to the results of the Valsalva and Parana manoeuvres in the SFJ, they were distributed into four groups. The diameter of the GSV and the clinical state according to the clinical, aetiological, anatomical and pathological element classification were recorded for each group.

RESULTS

Statistically significant differences were obtained for the diameter and the clinical state in patients with positive manoeuvres with regard to other groups. The diameter was greater and the clinical state more severe (C4, C5 and C6) when two manoeuvres were positive.

CONCLUSIONS

The presence of both positive manoeuvres in the SFJ is related to severe clinical states and greater diameters of the GSV, allowing the establishment of a prognosis of the CVI and the most suitable surgical approach.

Time-dependent pharmacokinetics of cyclosporine (Neoral) in de novo renal transplant patients

PURPOSE

A model for the large scale temporal trend in the oral bioavailability of microemulsion cyclosporine (Neoral) (CsA) is established, with dependence on post-(renal) transplantation day (PTD).

METHODS

Twenty de novo adult renal transplant recipients were monitored for CsA administered orally q12 h. A model development group (11 patients, 315 blood concentration samples) was screened at 2 h (C(2); n = 92), 3 h (C(3); n = 56) and at predose troughs (C(min); n = 167) over periods of up to 75 days. The final model was tested in nine patients with C(min) (n = 580) monitored across 4-5 years. The doses varied between 100 and 538 mg with an apparent hyperbolic trend in C(2)/dose vs. PTD. A nonlinear mixed effects modelling (NONMEM) approach was used to obtain population and individual patient one-compartment pharmacokinetic (PK) parameters for oral CsA, which carry implicit the bioavailability (F).

RESULTS

In the final PK model (PK-f) the F was modelled via a simple function for the temporal (days) trend of the bioavailability after transplantation as, F(f) = 1-alpha * exp(-lambda * PTD) resulting in a 28% reduction in the unexplained intra-individual variability. The population PK-f parameters were, for apparent clearance [mean, 95% confidence interval (interindividual CV%)] Cl/F(f) = 17.0 (13.8-20.2) L/h (27%), apparent central compartment volume of distribution, V/F(f) = 134 L (108-160) (28%), and lambda = 0.037/day (0.005-0.069) (120%). The absorption rate k(a) and the parameter alpha were approximated iteratively as 4/h and 0.62 respectively. The PK-f was structurally superior to the base model in explaining part of the within subject (occasion) variability and predicting the exposure surrogates C(2) and C(3). Also, the PK-f was better than the base model with Bayesian fitting of individual profiles in that group.

CONCLUSION

The PTD-dependent relative bioavailability model provides a rational means of steering dose titration of CsA in de novo renal transplantation patients by removing the large scale PK adjustment signal, either through nomograms or as a Bayesian prior.

Altered dose-to-effect of propofol due to pharmacokinetics in rats with experimental diabetes mellitus

Pathology related alterations in the pharmacokinetics or the pharmacodynamics of propofol could contribute to the observed large variability in the hypnotic dose. We have tested the influence of diabetes mellitus on the induction dose and the pharmacokinetics and pharmacodynamics of propofol in rats. Diabetes was induced in rats by administration of streptozotocin (60 mg kg(-1), i. p.) while control rats received vehicle intraperitoneally. All animals had glucose, cholesterol, triglycerides and albumin levels measured. In-vitro protein binding was determined by ultrafiltration. Rats were randomly split into set 1 (dose-concentration-effect study) with control and streptozotocin rats, and set 2 (pharmacokinetic study), with control and streptozotocin rats. Rats in the effect set received either a variable infusion of 6 mg kg(-1) min(-1) propofol until onset (induction dose) of the hypnotic effect (loss of the righting reflex), or a 15 mg kg(-1) bolus to assess offset time (recovery of the righting reflex). Blood (C(blood)) and brain (C(brain)) propofol concentrations at onset and offset were assayed by HPLC. In the pharmacokinetic study, propofol was administered intravenously at 6 mg kg(-1) min(-1) for 2 min. Arterial blood samples were collected between 0.5 and 540 min and assayed for propofol. A mixed effects compartmental pharmacokinetic modelling method (NONMEM) was used to analyse the observations and variabilities. The dose necessary for onset differed between streptozotocin and controls, and so did the pharmacokinetics with two- and three-compartment descriptions, respectively. C(blood) and C(brain) at onset and offset were similar, possibly rejecting changes in pharmacodynamics. The total and unbound volume of distribution was significantly lower in the streptozotocin group with no differences in clearance (CL) between streptozotocin and controls, (mean (inter-animal CV%)) CL = 0.026 (17%) and 0.025 (62%) L min(-1), respectively. Individual Bayes Vd(ss) (volume of distribution at steady state) were different, (mean (s. d.)) Vd(ss) = 7.7 (2.67) and 1.11 (0.09) L, respectively. The pharmacokinetic model was validated by comparison with the data from set 1. Simulations of total and unbound C(blood), for both groups, at the hypnotic dose for the controls, revealed differences throughout the time course of the pharmacokinetics. The difference observed in the induction dose of propofol to streptozotocin and control rats was due to alterations in the pharmacokinetics, secondary to the pathology.

Influence of formulation on propofol pharmacokinetics and pharmacodynamics in anesthetized patients

BACKGROUND

In anesthesia with propofol, variability persists besides sophisticated effect targeting. Drug formulation may be another factor. We have analyzed, retrospectively, the pharmacokinetics (PK) and pharmacodynamics (PD) in monitored surgery patients anesthetized with one each of five formulations of propofol.

METHODS

Propofol 1% ('form' 1: Diprivan(Zeneca Limited, Macclesfield, UK), 2: Recofol(Schering Espana, Madrid, Spain), 3: Ivofol(Juste, Madrid, Spain), 4: Propofol Abbott (Abbott Laboratories, Madrid, Spain), 5: Fresenius (Fresenius Kabi Espana, Barcelona, Spain)) was administered to 77 ASA I-II patients of age [mean (range) 44 (18-65) years]. Induction of anesthesia was with varying propofol doses up to endpoints of either 60 on the Bispectral Index system (BIS) in group I (n = 48, model development) or standard clinical signs in group II (n = 29, validation). Maintenance was with three 10-min infusions of 10, 8 and 6 mg kg(-1) h(-1). Three blood samples were obtained from each subject, immediately after induction, and at 15 and 30 min on maintenance, with BIS and hemodynamic variables recorded at these times also. Total and free blood concentrations (Cb) of propofol were determined with HPLC. Pharmacokinetic and PD models with link equilibration rate ke0, were studied with a mixed-effects procedure (NONMEM).

RESULTS

The induction dose (group I) showed large interindividual variability [mean (range) 163 (90-290 mg)] that correlated significantly with age, basal systolic blood pressure and formulation. The PK of propofol (basic model) was described by a one-compartment model with (typical value [interindividual coefficient of variation percent (CV%)]) CL=2.30 l min(-1) (27%) and V=8.40 l (80%). Weight (WT) and formulation, within NONMEM, were found to be significant covariates for CL and V, reducing their CV% to 25% and 74%, respectively. The final PK/PD model, which includes formulation, showed a 50% reduction in the CV% for both the ke0 and the residual error. This PK/PD model was validated in group II with 33% precision and no bias.

CONCLUSION

The PK and PD are not equal for all formulations, which contributes to an increase in variability of the observed effect.

Production of antigen-specific human monoclonal antibodies: comparison of mice carrying IgH/kappa or IgH/kappa/lambda transloci

Here we compare human monoclonal antibody (MAb) production from mouse strains that carry disruptions of their endogenous mouse IgH/IgK loci and harbor human IgM + Igkappa(BABkappa) or human IgM + Igkappa + IgA transloci (BABkappa,lambda). We found that whereas both strains proved effective for the isolation of antigen-specific IgM antibodies, many of the IgM MAbs elicited from BABkappa comprise human mu chains that are associated with mouse lambda chains. In contrast, BABkappa,lambda mice gave rise to fully functional, polymeric human IgM antibodies comprising both human IgH and human IgL chains. Therefore, the inclusion of a human Iglambda translocus (in addition to the human IgH + Igkappa transloci) not only diminishes problems of endogenous mouse Iglambda expression but also provides a strain of mice that yields fully human MAbs to a wide range of antigens, as witnessed by the isolation of MAbs to human blood cells, tumor cell lines, and an immunoglobulin idiotype.

Altered disposition and effect of lerisetron in rats with elevated alpha 1-acid glycoprotein levels

PURPOSE

To examine the effect of changes in plasma alpha1-acid glycoprotein (AAG) levels on the pharmacokinetics (PK) and pharmacodynamics (PD) of lerisetron, a novel serotonin 5-HT3 receptor antagonist, in the rat.

METHODS

After subcutaneous administration of turpentine oil, AAG was significantly elevated compared with controls. The PK of unchanged lerisetron (UL; high-performance liquid chromatography with radioactivity monitoring) and total lerisetron (TL; unchanged + changed, scintillation counting) was characterized post intravenous (i.v.) 14C lerisetron (50 microg/kg) in control and turpentine oil pretreated rats. The PK (0-180 min) was described by a two-compartmental model. Protein binding of lerisetron in vitro was measured using an ultrafiltration technique. The effect of lerisetron (5 microg/kg, i.v.) over 180 min was measured in anesthetized rats (control and pretreated) with the Bezold-Jarisch reflex (inhibition of bradycardia after 16 microg/kg serotonin i.v.) as the endpoint. PD parameters were estimated by sigmoid Emax models.

RESULTS

The unbound fraction was significantly diminished in pretreated rats (mean +/- SEM) (6.60 +/- 1.23% vs. control 14.4 +/- 1.40%, P < 0.05). Volume of distribution (V) and clearance for UL and TL were significantly decreased when compared to the controls (P < 0.0001 for UL and P < 0.05 for TL). Plasma clearance based on unbound concentration for UL did not differ between groups but the unbound V and steady-state unbound V remained decreased (P < 0.05 and P < 0.0001). Pretreated rats showed a significantly diminished drug effect: the area under the E-t curve over 180 min was (mean +/- SEM) 5,189 +/- 657.7 in control animals vs. 3,486 +/- 464.4 in the pretreated group (P < 0.05). The EC50 (concentration at half maximum effect) for UL and TL were increased in pretreated rats and were not compensated when the unbound concentration was used.

CONCLUSIONS

An increase in AAG causes alterations in the PK and PD of lerisetron, and because this is not compensated with the unbound concentration, we suggest that mechanisms not linked to protein binding may be involved.

Rhegmatogenous retinal detachment in myopic eyes after laser in situ keratomileusis

PURPOSE

To report the characteristics and frequency of rhegmatogenous retinal detachment (RRD) after laser in situ keratomileusis (LASIK) for the correction of myopia in a large case series.

SETTING

Private practices, Caracas, Venezuela.

METHODS

Five refractive surgeons and 31 739 myopic eyes that had surgical correction of a mean myopia of -6.01 diopters (D) (range -0.75 to -29.00 D) participated in this study. Laser in situ keratomileusis was performed in all eyes. Patients were followed for a mean of 36 months (range 6 to 48 months). The clinical charts of patients who developed RRD after LASIK were reviewed.

RESULTS

Twenty eyes (17 patients) developed RRD after LASIK. Rhegmatogenous retinal detachments occurred a mean of 13.9 months (range 1 to 36 months) after LASIK. The mean pre-LASIK myopia in eyes that developed an RRD was -7.02 D (range -1.50 to -16.00 D). Most RRDs and retinal breaks occurred in the temporal quadrants (71.4%). Rhegmatogenous retinal detachments were managed with vitrectomy, cryoretinopexy, scleral buckling, argon laser retinopexy, or pneumatic retinopexy techniques. The frequency of RRD after LASIK was 0.06%.

CONCLUSIONS

Rhegmatogenous retinal detachment after LASIK for the correction of myopia is infrequent. If managed promptly, RRD will result in good vision. Before LASIK is performed, patients should have a thorough dilated indirect fundoscopy with scleral depression and treatment of any retinal lesion predisposing to the development of an RRD.

Rhegmatogenous retinal detachment after laser-assisted in situ keratomileusis (LASIK) for the correction of myopia

PURPOSE

To report a case series of rhegmatogenous retinal detachment (RRD) after laser-assisted in situ keratomileusis (LASIK) and its incidence at a mean of 24 months.

METHODS

The clinical charts of patients who experienced RRD after LASIK were reviewed. Five refractive surgeons and 24,890 myopic eyes that underwent surgical correction of myopia ranging from -0.75 to -29.00 diopters (D) (mean, -6.19 D) participated in this study.

RESULTS

Thirteen eyes from 12 patients developed RRD after LASIK. Rhegmatogenous RD occurred between 1 and 36 months (mean, 12.6 months) after LASIK. Eyes that developed RRD had from -1.50 to -16.00 D of myopia (mean, -6.96 D) before LASIK. Rhegmatogenous RD were managed with vitrectomy, cryoretinopexy, scleral buckling, argon laser retinopexy, or pneumatic retinopexy techniques. The incidence of RRD at a mean of 24 months after LASIK in this study was 0.05%.

CONCLUSIONS

Rhegmatogenous RD after LASIK is infrequent. If managed promptly, good vision can result. No cause-effect relationship between LASIK and RD can be proved from this study, but the authors recommend that patients scheduled for refractive surgery undergo a thorough dilated indirect fundus examination with scleral depression and treatment of any retinal lesions predisposing them to the development of RRD before LASIK surgery is performed.

Antitubercular activity of triterpenoids from Lippia turbinata

Assay-guided fractionation of the antitubercular MeOH-CH(2)Cl(2) extract obtained from Lippia turbinata led to the isolation of four novel triterpenoids-3beta,25-epoxy-3alpha,21alpha-dihydroxy-22beta-(3-methylbut-2-en-1-oyloxy)olean-12-ene-28-oic acid (1); 3beta,25-epoxy-3alpha,21alpha-dihydroxy-22beta-angeloyloxyolean-12-ene-28-oic acid (2); 3beta,25-epoxy-3alpha,21alpha-dihydroxy-22beta-tigloyloxyolean-12-ene-28-oic acid (3); and 3beta,25-epoxy-3alpha-hydroxy-22beta-(2-methylbutan-1-oyloxy)olean-12-ene-28-oic acid (4)-together with the known triterpenoids lantanilic acid (5), camaric acid (6), lantanolic acid (7), and rehmannic acid (8). The MIC values of 1-8 for growth inhibition of Mycobacterium tuberculosis were determined in the radiorespirometric BACTEC system.

Oleanane triterpenes from Junellia tridens

Three novel triterpenes, 3,4-seco-olean-12-ene-3,28-dioic acid (4), 3alpha-hydroxyolean-11-en-28,13beta-olide (5), and 3alpha-hydroxyoleane-11:13(18)-dien-28-oic acid (6), were isolated from the aerial parts of the Argentinean shrub, Junellia tridens. Another five compounds-oleanolic (1), oleanonic (2), and epioleanolic acids (3), all biosynthetically related to the three new oleananes, and epibetulinic acid (7) and sitosterol (8)-were also isolated. Structures were elucidated primarily by 1D and 2D NMR and mass spectrometry, and all protons and carbons of the three novel compounds were fully assigned by NMR. We report the minimum inhibitory concentrations of these compounds against Mycobacterium tuberculosis and conclude that they are responsible for antitubercular activity originally observed in the crude plant extract. LC-MS data is provided on the occurrence of triterpenes 1-6 in six other species of Junellia.

Newborn screening for human immunodeficiency virus infection in the Bronx, NY, and evolving public health policy

New advances in the diagnosis and treatment of HIV infection continue to propel changes in public understanding of HIV infection and the administration of public health law. Over the past decade, New York State has moved from a policy of blind newborn screening for seroprevalence data to mandatory HIV testing as part of the statewide Newborn Screening (NBS) Program. A new statewide program of expedited HIV testing (48-hr turnaround results) of pregnant women and newborns (whose HIV status is unknown at the time of delivery) began in the summer of 1999. To better understand the impact this program might have on the patients who receive health care at Lincoln Medical and Mental Health Center (Lincoln Hospital), we evaluated our experience with the current NBS program prior to inauguration of the new expedited testing program. We evaluated the NBS program from February 1, 1997, to January 31, 1999, including total number of HIV-exposed/infected infants born, mother's HIV status (if known) at the time of delivery, amount of time between blood sampling and return of the test results to the Hospital, and medical follow-up of infants with positive newborn screening test results. This was a retrospective study of the NBS registry and the medical records of patients who receive primary health care from the Pediatric Immunology Service of the Department of Pediatrics at Lincoln Hospital. One hundred and four newborns were identified with positive-HIV antibody (HIV-Ab-positive), and 13 (12.5%) were confirmed to be HIV-infected by positive polymerase chain reaction (PCR) test of viral DNA. Sixty-five (62.5%) of the newborns with positive NBS screening test results were born to mothers who were known to be HIV-infected prior to delivery; 39 (37.5%) were unanticipated. Four (30%) of the 13 HIV-infected babies were born to mothers who were known to be HIV-infected prior to delivery, and 9 (70%) were born to mothers whose HIV status was unknown at the time of delivery. Eighty percent (80%) of HIV-Ab-positive infants continued to receive follow-up care at Lincoln Hospital. Relocation to other health-care facilities occurred as a result of parental choice or due to foster care placement. No babies were "lost" from the NBS program. The average time between sampling and receipt of results for all blood tests was 16 days (range 10 to 141). Nearly 40% of newborns who acquired HIV infection from their mothers were unanticipated because the mother's HIV status was unknown at the time of delivery. These unanticipated HIV-infected infants represent missed opportunities for prevention of maternal-to-child transmission of HIV infection and early therapeutic intervention for HIV-infected infants. The new expedited HIV-testing program for New York State will facilitate early diagnosis, prevention and treatment of the HIV-exposed/infected infant for whom maternal HIV status is unknown at the time of delivery.

Relating induced changes in EEG signals to orientation of visual stimuli using the ESI-256 machine

The focus of this study is to investigate the relations that exist between changes in the orientation of simple visual stimuli displayed to a subject and the induced changes in brain activity recorded as EEG signals. These signals are recorded using the Electric Source Imaging with 256 electrodes (ESI-256). The 256-channel EEG signals of four subjects were measured monopolarly. Each subject was stimulated visually for approximately 7.5 minutes. The stimuli consisted of a series of 300 images depicting four basic orientations of a simple graphical element: a white bar on a black background, with each one of the four orientations (horizontal, vertical, +45 degrees and -45 degrees) shown a total of 75 times in a random order. The notion of missing information under certain orientations is not addressed at this juncture. The EEG signals produced by each subject were recorded in a continuous mode using a sampling rate of 1 kHz. Pre-processing of the raw EEG data obtained consisted of epoching, exclusion of faulty electrodes, and reduction of electro-oculogram (EOG) noise due to eye blinks. Topographical maps displaying brain activities and their individual electrode recordings are used as two different means for assessing these changes. It is important to note that the simplicity of the visual stimuli was considered in view of the massive data collected for interpretation. Our goal is to observe and determine new measures that would allow for the quantification and interpretation of such EEG brain activities. Such findings might prove useful for the later use of more complex stimuli and the potential development of size and orientation independent algorithms in image processing.

Leptin and IGF-I levels in unconditioned male volunteers after short-term exercise

We have previously shown that serum gonadotropins, particularly LH, decline after acute exercise in male volunteers. The mechanism for this decline is unknown. Plasma leptin and IGF-I concentrations were measured in seven male volunteers after acute exercise to exhaustion using the Bruce protocol. Leptin concentrations declined following exercise reaching nadir values 30-120 min after exercise. As anticipated, plasma IGF-I concentrations showed a transient rise immediately after exercise falling thereafter to nadir levels 60-90 min after exercise before returning towards baseline levels. In view of the previously described decline in gonadotropin release after acute exercise, the decline in plasma leptin levels, perhaps related to the rise in IGF-I, may play a role in exercise-induced inhibition of gonadotropin release presumably by inhibition of GnRH secretion.