Contraceptive Provision to Women With Intellectual and Developmental Disabilities Enrolled in Medicaid

OBJECTIVE

To compare contraceptive provision to women with and without intellectual and developmental disabilities enrolled in North Carolina Medicaid.

METHODS

Our retrospective cohort study used 2019 North Carolina Medicaid claims to identify women aged 15-44 years with and without intellectual and developmental disabilities at risk for pregnancy who were continuously enrolled during 2019 or had Family Planning Medicaid with at least one claim. We calculated the proportion in each cohort who received 1) most or moderately effective contraception, 2) long-acting reversible contraception, 3) short-acting contraception, and 4) individual methods. We classified contraceptive receipt by procedure type and disaggregated across sociodemographic characteristics. Adjusting for age, race, ethnicity, and urban or rural setting, we constructed logistic regression models to estimate most or moderately effective contraceptive provision odds by intellectual and developmental disability status and by level or type of intellectual and developmental disability. We performed subanalyses to estimate co-occurrence of provision and menstrual disorders.

RESULTS

Among 9,508 women with intellectual and developmental disabilities and 299,978 without, a significantly smaller proportion with intellectual and developmental disabilities received most or moderately effective contraception (30.1% vs 36.3%, P <.001). With the exception of injectable contraception, this trend was consistent across all measures and remained statistically significant after controlling for race, ethnicity, age, and urban or rural status (adjusted odds ratio 0.75, 95% CI 0.72-0.79; P <.001). Among those who received most or moderately effective contraception, a significantly greater proportion of women with intellectual and developmental disabilities had co-occurring menstrual disorders (31.3% vs 24.3%, P <.001).

CONCLUSION

These findings suggest disparities in contraceptive provision and potential differences in clinical indication by intellectual and developmental disability status. Future studies should investigate reasons for and barriers to contraceptive use among women with intellectual and developmental disabilities.

Comparing fears about paediatric HIV disclosure to the lived experiences of parents and guardians: a prospective cohort study

OBJECTIVE

We aimed to: (1) follow parents and guardians through the process of paediatric HIV disclosure to understand how often pre-disclosure worries are realised; and (2) estimate the effects of disclosure on child, caregiver, and family well-being.

DESIGN

We conducted a 12-month prospective cohort study in Zimbabwe with 123 primary caregivers of children ages 9 to 15 years who were HIV positive but did not know their serostatus at baseline. By the end of the study period 65 caregivers reported that their child learned his or her HIV-positive status.

MAIN OUTCOME MEASURES

We used three waves of data to compare caregivers' pre-disclosure worries to post-disclosure reports and to characterise associations between disclosure and well-being of the child (Strengths and Difficulties Questionnaire), caregiver (Patient Health Questionnaire-9), and family (Family Relationship Quality) over time.

RESULTS

Caregivers' pre-disclosure worries and fears about how their child would react to disclosure of their HIV status largely went unrealised. Furthermore, we did not find strong evidence of clinically-important increases in problems on average following disclosure.

CONCLUSION

Findings support the call to identify supportive intervention strategies that address caregiver fears at the beginning of the disclosure process.

Prevalence and risk factors of suicide and suicidal ideation in veterans who served in the British Armed Forces: a systematic review

INTRODUCTION

Research into the factors resulting in suicide in the military veteran population has yet to reach a consensus. Available research is concentrated on a small number of countries, and there is a lack of consistency with contradictory conclusions. The USA has produced a significant amount of research in a country where suicide is identified as a national health crisis, but in the UK, there is little research regarding veterans from the British Armed Forces.

METHODS

This systematic review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Corresponding literature searches were conducted in PsychINFO, MEDLINE and CINAHL. Articles that discussed suicide, suicidal ideation, prevalence or risk factors among British Armed Forces veterans were eligible for review. A total of 10 articles met the inclusion criteria and were analysed.

RESULTS

Veterans' suicide rates were found to be comparable to those of the general UK population. The method of suicide used was most commonly found to be hanging and strangulation. Firearms was recorded in 2% of suicide cases. Demographic risk factors were often contradictory with some research stating that there was risk in older veterans and some in younger. However, female veterans were found to be at higher risk than female civilians. Those who had deployed on combat operations were at lower risk of suicide, with research finding that veterans who took longer to seek help for mental health (MH) difficulties reported more suicidal ideation.

CONCLUSIONS

Peer-reviewed research publications have revealed that UK veteran suicide prevalence is broadly comparable to the general population while highlighting differences across international armed forces. Veteran demographics, service history, transition and MH have all been identified as potential risk factors of suicide and suicidal ideation. Research has also indicated that female veterans are at higher risk than that of their civilian counterparts due to veterans being predominantly male; this could skew results and requires investigation. Current research is limited and further exploration of suicide prevalence and risk factors in the UK veteran population is required.

Toward an Integrated Framework in Health and Human Rights Education: Transformative Pedagogies in Social Medicine, Collective Health, and Structural Competency

Global health equity is at a historically tenuous nexus complicated by economic inequality, climate change, mass migration, racialized violence, and global pandemics. Social medicine, collective health, and structural competency are interdisciplinary fields with their own histories and fragmentary implementation in health equity movements situated both locally and globally. In this paper, we review these three fields' historical backgrounds, theoretical underpinnings, and contemporary contributions to global health equity. We believe that intentional dialogue between these fields could promote a generative discourse rooted in a shared understanding of their historical antecedents and theoretical frameworks. We also propose pedagogical tools grounded within our own critical and transformative pedagogies that offer the prospect of bringing these traditions into greater dialogue for the purpose of actualizing the human right to health.

Parenting in a conflict-affected setting: Discipline practices, parent-child interactions, and parenting stress in Liberia

Children in conflict-affected settings are at increased risk for exposure to violence, placing particular importance on caregiving environments. This study first describes parenting in urban Liberia by evaluating parent-child interactions, the use and acceptance of harsh and nonharsh discipline, discipline preferences, and the co-occurrence of positive interactions and harsh discipline. The relationship between parenting stress and harsh discipline attitudes and behaviors is then tested. Participants included 813 parents with a child aged 3 or 4 years old. A quantitative survey battery assessed parent-child interactions; discipline practices, preferences, and attitudes; and parenting stress. Parents reported frequent use and high acceptance of nonharsh discipline, as well as frequent positive interactions with their child. Though parents reported less frequent use and low acceptance of harsh discipline, preference for harsh discipline-based on hypothetical situations rather than self-report-was common. There was co-occurrence of frequent positive interactions and frequent harsh discipline, with one third reporting high frequency of both. Regression analysis revealed greater parenting stress (β = .15, t = 4.49, p < .001) and stronger acceptance of harsh discipline (β = .47, t = 15.49, p < .001) were associated with more frequent harsh discipline. Acceptance of harsh discipline interacted with parenting stress to predict the use of harsh discipline (β = -.09, t = -3.09, p < .01). Among parents with lowest average acceptance of harsh practices, stress predicted more frequent harsh discipline, but acceptance did not moderate the association for those who are most accepting of harsh practices. Building on existing parenting strengths and addressing parenting stress could promote nurturing caregiving in conflict-affected settings. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The Health Innovation Impact Checklist: a tool to improve the development and reporting of impact models for global health innovations

Donor financing is increasingly relying on performance-based measures that demonstrate impact. As new technologies and interventions enter the innovation space to address global health challenges, innovators often need to model their potential impact prior to obtaining solid effectiveness data. Diverse stakeholders rely on impact modeling data to make key funding and scaling decisions. With a lack of standardized methodology to model impact and various stakeholders using different modeling strategies, we propose that a universal innovation impact checklist be used to aid in transparent and aligned modeling efforts. This article describes a new Health Innovation Impact Checklist (HIIC) – a tool developed while evaluating the impact of health innovations funded under the Saving Lives at Birth (SL@B) program. SL@B, a global health Grand Challenge initiative, funded 116 unique maternal and newborn health innovations, four of which were selected for cost-effectiveness analyses (CEAs) within our evaluation. A key data source needed to complete a CEA was the lives saved estimate. HIIC was developed to help validate draft impact models from the SL@B donors and our own team’s additional modeling efforts, to ensure the inclusion of standardized elements and to pressure test assumptions for modeling impact. This article describes the core components of HIIC including its strengths and limitations. It also serves as an open call for further reviewing and tailoring of this checklist for applicability across global efforts to model the impact of health innovations.

Deploying machine learning with messy, real world data in low- and middle-income countries: Developing a global health use case

The rapid emergence of machine learning in the form of large-scale computational statistics and accumulation of data offers global health implementing partners an opportunity to adopt, adapt, and apply these techniques and technologies to low- and middle-income country (LMIC) contexts where we work. These benefits reside just out of the reach of many implementing partners because they lack the experience and specific skills to use them. Yet the growth of available analytical systems and exponential growth of data require the global digital health community to become conversant in this technology to continue to make contributions to help fulfill our missions. In this community case study, we describe the approach we took at IntraHealth International to inform the use case for machine learning in global health and development. We found that the data needed to take advantage of machine learning were plentiful and that an international, interdisciplinary team can be formed to collect, clean, and analyze the data at hand using cloud-based (e.g., Dropbox, Google Drive) and open source tools (e.g., R). We organized our work as a “sprint” lasting roughly 10 weeks in length so that we could rapidly prototype these approaches in order to achieve institutional buy in. Our initial sprint resulted in two requests in subsequent workplans for analytics using the data we compiled and directly impacted program implementation.

Applying WHO COVID-19 workforce estimate tools remotely in an African context: a case report from Mali and Kenya

BACKGROUND

The COVID-19 pandemic has increased the burden on health systems, particularly in low- and middle-income countries, where health systems already struggle. To meet health workforce planning needs during the pandemic, IntraHealth International used two tools created by the World Health Organization (WHO) Regional Office for Europe. The Health Workforce Estimator (HWFE) allows the estimation of the quantity of health workers needed to treat patients during a surge, and the Adaptt Surge Planning Support Tool helps to predict the timing of a surge in cases and the number of health workers and beds needed for predicted caseload. These tools were adapted to fit the African context in a rapid implementation over 5 weeks in one region in Mali and one region in Kenya with the objective to test the feasibility of adapting these tools, which use a Workload Indicators of Staffing Need (WISN)-inspired human resources management methodology, to obtain daily and surge projections of COVID-19 human resources for health needs.

CASE PRESENTATION

Using a remote team in the US and in-country teams in Mali and Kenya, IntraHealth enacted a phased plan to gather stakeholder support, collect data related to health systems and COVID-19 cases, populate data into the tools, verify modeled results with results on the ground, enact policy measures to meet projected needs, and conduct national training workshops for the ministries of health.

CONCLUSIONS

This phased implementation in Mali and Kenya demonstrated that the WISN approach applied to the Health Workforce Estimator and Adaptt tools can be readily adapted to the local context for African countries to rapidly estimate the number of health workers and beds needed to respond to the predicted COVID-19 pandemic caseload. The results may also be used to give a proxy estimate for needed health supplies-e.g., oxygen, medications, and ventilators. Challenges included accurate and timely data collection and updating data. The success of the pilot can be attributed to the adapted WHO tools, the team composition in both countries, access to human resources data, and early support of the ministries of health, with the expectation that this methodology can be applied to other country contexts.

Translated search strategies may require truncated subject headings for efficient public health retrieval

BACKGROUND

Small databases, such as Health Management Information Consortium (HMIC) and Social Policy and Practice (SPP), can add value to systematic searches. Search strategies designed for large databases may not be appropriate in small sources. A different approach to translating strategies could ensure that small databases are searched efficiently.

OBJECTIVES

To establish the contribution HMIC and SPP made to public health guidelines (PHGs); and to recommend an efficient method of translating search strategies.

METHODS

Eight PHGs were analysed to establish how many included publications were retrieved from HMIC and SPP. Six options for translating strategies from MEDLINE, using variations of free text and subject terms, were compared.

RESULTS

Health Management Information Consortium contributed 15 and SPP eight of the 483 publications cited in the PHGs. The free-text only search was the one option to miss an included publication. The heading word (with truncation) option was more precise than applying subject headings.

DISCUSSION

There is a risk of missing relevant publications in free-text only searches and it is preferable to include subject terms efficiently.

CONCLUSION

The heading word (with truncation) option did not miss the evidence included in the PHGs and was the most efficient method for translating MEDLINE to HMIC and SPP.

Improving global maternal and newborn survival via innovation: Stakeholder perspectives on the Saving Lives at Birth Grand Challenge

The Saving Lives at Birth (SL@B) funding partners joined in 2011 to source, support, and scale maternal and newborn health (MNH) innovations to improve maternal and newborn survival by focusing on the 24 hours around the time of birth. A multi-methods, retrospective portfolio evaluation was conducted to determine SL@B's impact. Forty semi-structured, key informant interviews (KIIs) were conducted with experts in global MNH based in low- and middle-income and in high-income countries to assess the SL@B program. KIIs were conducted with global MNH technical experts, innovators, government officials in low- and middle-income countries, donors, private investors, and implementing partners to include the full spectrum of voices involved in identifying and scaling innovations. Data were analyzed using thematic analysis. Stakeholders believe the SL@B program has been successful in changing the way maternal and newborn health programs are delivered with a focus on doing things differently through innovation. The open approach to sourcing innovation was seen as positive to the extent that it brought more interdisciplinary stakeholders to think about the problem of maternal and newborn survival. However, a demand-driven approach that aims to source innovations that address MNH priority needs and takes into account the needs of end users (e.g. individuals and governments) was suggested as a strategy for ensuring that more innovations go to scale.

Veteran help-seeking behaviour for mental health issues: a systematic review

INTRODUCTION

Serving military personnel and veterans have been identified to have a high prevalence of mental health disorders. Despite this, only a significantly small number seek mental healthcare. With the UK beginning to invest further support to the armed forces community, identification of barriers and facilitators of help-seeking behaviour is needed.

METHODS

Corresponding literature search was conducted in PsycINFO, PsycArticles, Medline, Web of Science and EBSCO. Articles which discussed barriers and facilitators of seeking help for mental health concerns in the veteran population were included. Those which discussed serving personnel or physical problems were not included within this review. A total of 26 papers were analysed.

RESULTS

A number of barriers and facilitators of help-seeking for a mental health issue within the veteran population were identified. Barriers included stigma, military culture of stoicism and self-reliance, as well as deployment characteristics of combat exposure and different warzone deployments. Health service difficulties such as access and lack of understanding by civilian staff were also identified. Facilitators to help combat these barriers included a campaign to dispel the stigma, including involvement of veterans and training of military personnel, as well as more accessibility and understanding from healthcare staff.

CONCLUSIONS

While some barriers and facilitators have been identified, much of this research has been conducted within the USA and on male veterans and lacks longitudinal evidence. Further research is needed within the context of other nations and female veterans and to further indicate the facilitators of help-seeking among veterans.

Critical analysis of the Armed Forces Covenant Fund Trust Aged Veterans Fund

BACKGROUND

Relatively little research is available regarding the specific needs of older military veterans and the services introduced to support them. In 2016, the Armed Forces Covenant Fund Trust launched the Aged Veterans Fund (AVF), to understand the impact that military service may have on ageing, and to support initiatives targeting their health and well-being. This fund was financed for 5 years and included 19 UK portfolio projects.

METHOD

The paper presents a retrospective evaluation on the processes and impact of the AVF, with the intent of informing policy, educational services, service providers and stakeholders of the lessons learnt. The inclusion criteria was veterans and their families aged 65 years of age or over. In 2019, data were drawn from documentary evidence related to the programmes. Qualitative analysis were performed on 78 eligible sources and 10 themes were identified.

RESULTS

Programmes were rolled out via collaborative partnerships referrals, focusing on person-centred or skill-exchange approaches. Challenges were encountered, such as capacity and timelines issues. A limited amount of associated cost-savings was observed, even if examples of sustainability and high satisfaction were reported. Evidence was found of programmes boosting health and well-being outcomes, in raising awareness, and in positively impacting on clinical practice, such as re-admission rates.

CONCLUSION

The AVF programmes were successful in their intent to provide support to older veterans and their families. The findings provide indicators of the next steps required for the support of ageing veterans. Further investigation of the cost-effectiveness of age-friendly veterans' services is needed.

Caregiver self-efficacy to talk about sex predicts conversations about HIV transmission risk with perinatally infected young people in Zimbabwe

Given advances in care and treatment for HIV, perinatally infected young people are surviving into adolescence. These young people are making decisions about engaging in sexual relationships and it is critical to ensure they have the information they need to engage responsibly in sexual activity, particularly in an era where adherence to treatment could make their virus undetectable. The main objective of this analysis was to examine whether an HIV-positive young person's knowledge about forward transmission is associated with caregiver self-efficacy to talk about sex and general caregiver communication. Using data from a 12-month prospective cohort of caregivers of HIV-positive children aged 9-15 on ART and pre-ART in rural Zimbabwe, we found that caregiver self-efficacy to talk about sex predicted whether conversations about HIV transmission would occur between caregiver and the young person. However, by the end of 12-months, nearly two-thirds of caregivers of HIV-positive teenagers in our sample had still not explained how their adolescents could spread the virus to others despite these caregivers saying their adolescent should know this information at baseline. We discuss the implications for designing sexual and reproductive health (SRH) programs among populations of young people perinatally infected with HIV to ensure that this breakthrough generation receives the SRH support they need.

The NICE UK geographic search filters for MEDLINE and Embase (Ovid): Post-development study to further evaluate precision and number-needed-to-read when retrieving UK evidence

BACKGROUND

The National Institute for Health and Care Excellence's (NICE) United Kingdom (UK) geographic search filters for MEDLINE and Embase (OVID) retrieve evidence in literature searches for UK-focused research topics with high recall. Their precision and number-needed-to-read (NNR) was examined previously in case studies using a single review. This paper details a larger post-development study that was conducted to test the NICE UK filters' precision and NNR more extensively.

METHODS

The filters' recall of included UK references from 100 reviews was calculated. As reproducible search strategies were not available for every review, the MEDLINE filter's precision and NNR were calculated using strategies from 25 reviews. Strategies from nine reviews were used for the Embase filter.

RESULTS

The MEDLINE filter achieved an average of 96.4% recall for the included UK references from the 100 reviews and the Embase filter achieved an average of 97.4% recall. Compared to not using a filter, the MEDLINE filter achieved an average of 98.9% recall for the 25 reviews. Precision was increased by an average of 7.8 times, reducing the NNR from 357 to 46. The Embase filter achieved an average of 97.1% recall for the nine reviews. Precision was increased by an average of 5.1 times, reducing the NNR from 746 to 146.

CONCLUSION

There is more evidence to demonstrate that the NICE UK filters retrieve the majority of UK evidence from MEDLINE and Embase while increasing precision and reducing NNR. The filters can save time spent on selecting evidence for UK-focused research topics.

Effects of a sister's death in childbirth on reproductive behaviors: Difference-in-difference analyses using sisterhood mortality data from Indonesia

RATIONALE

Risk of maternal mortality increases rapidly during the intrapartum period making skilled care at delivery an effective intervention to reduce the risk of maternal death. Demand generation for skilled care typically focuses on institutional channels; however, much less attention has been paid to whether what women may learn through their social networks can potentially influence their choice of delivery care.

OBJECTIVE

The objective of this study was to analyze whether a sister's death in childbirth has the potential to improve delivery care choices for women who experience this event.

METHODS

This study uses retrospective reports of sister deaths - either in childbirth or from some other cause - reported in the sisterhood moratlity module from five waves of the Indonesia Demographic and Health Surveys (IDHS) spanning 1989 to 2012. A cross-sectional, difference-in-difference strategy compares delivery care behavior of women before and after losing a sister in childbirth to women before and after losing a sister of reproductive age from some other cause in an intent-to-treat framework.

RESULTS

Women are less likely to give birth at home after losing a sister in childbirth relative to women who lose a sister from some other cause. Losing a sister in childbirth may trigger behaviors that help usher women of lower socioeconomic status into formal delivery care.

CONCLUSION

This study extends the literature on health behavior change through social networks to improve delivery care. Public health campaigns should consider social networks when designing messages around maternal mortality in order to help women at risk of maternal mortality make decisions that reduce their risk of and ultimately avoid maternal death.

Using a Chord Diagram to Visualize Dynamics in Contraceptive Use: Bringing Data into Practice

We applied a novel approach to visualizing contraceptive histories from the Demographic and Health Surveys (DHS) contraceptive calendar to elucidate patterns of contraceptive switching and discontinuation (e.g., "churn" in contraceptive use across 2 points in time). Taking the contraceptive calendar from the 2014 Kenya DHS, we used R, an open source statistical programming platform, and the chorddiag package to create interactive chord diagrams to visualize contraceptive use trajectories, including switching and discontinuation, for all contraceptive types queried in the DHS. We present screenshots from the interactive version. We also tested the usefulness of our chord diagram with potential users, including family planning researchers and advocates. Chord diagrams are visually appealing and provide users with the ability to investigate unique patterns in contraceptive discontinuation using publicly available data from the DHS. After receiving a brief orientation to a chord diagram, users found the chord diagram easy to understand and manipulate. The chord diagram is a potentially powerful way for family planning researchers, advocates, and program managers to visualize women's contraceptive trajectories and provides insights into the churn in contraceptive use between 2 discrete time periods.

The Embase UK filter: validation of a geographic search filter to retrieve research about the UK from OVID Embase

BACKGROUND

The authors developed a validated geographic search filter to retrieve research about the United Kingdom (UK) from OVID Embase. It was created to be used alongside their previously published OVID MEDLINE UK filter in systematic literature searches for context-sensitive topics.

OBJECTIVES

To develop a validated geographic search filter to retrieve research about the UK from OVID Embase.

METHODS

The Embase UK filter was translated from the MEDLINE UK filter. A gold standard set of references was generated using the relative recall method. The set contained references to publications about the UK that had informed National Institute for Health and Care Excellence (NICE) guidance and it was used to validate the filter. Recall, precision and number-needed-to-read (NNR) were calculated using a case study.

RESULTS

The validated Embase UK filter demonstrated 99.8% recall against the references with UK identifiers in the gold standard set. In the case study, the Embase UK filter demonstrated 98.5% recall, 7.6% precision and a NNR of 13.

CONCLUSION

The Embase UK filter can be used alongside the MEDLINE UK filter. The filters have the potential to save time and associated resource costs when they are used for context-sensitive topics that require research about UK settings.

The medline UK filter: development and validation of a geographic search filter to retrieve research about the UK from OVID medline

BACKGROUND

A validated geographic search filter for the retrieval of research about the United Kingdom (UK) from bibliographic databases had not previously been published.

OBJECTIVES

To develop and validate a geographic search filter to retrieve research about the UK from OVID medline with high recall and precision.

METHODS

Three gold standard sets of references were generated using the relative recall method. The sets contained references to studies about the UK which had informed National Institute for Health and Care Excellence (NICE) guidance. The first and second sets were used to develop and refine the medline UK filter. The third set was used to validate the filter. Recall, precision and number-needed-to-read (NNR) were calculated using a case study.

RESULTS

The validated medline UK filter demonstrated 87.6% relative recall against the third gold standard set. In the case study, the medline UK filter demonstrated 100% recall, 11.4% precision and a NNR of nine.

CONCLUSION

A validated geographic search filter to retrieve research about the UK with high recall and precision has been developed. The medline UK filter can be applied to systematic literature searches in OVID medline for topics with a UK focus.

Use of social media by new library professionals: Outcomes from a UK survey

This research explores the connection between social media and independent continuing professional development, focusing on new professionals within the UK and Ireland who graduated between 2010 and 2015, based on Ruddock’s definition (see Appendix 1). Two online surveys were conducted to ascertain why continuing professional development networks have been created and why new professionals use them. The first survey was completed by 100 new professionals; the second was completed by four continuing professional development network founders. This paper explores the relationship between the uptake of continuing professional development and social media usage by new professionals and highlights the reasons social media are used by new professionals for continuing professional development which include cost, variety of continuing professional development options, and removal of boundaries, e.g. geographical, hierarchical. The survey also found that network founders used social media to promote continuing professional development and engage with users.

The necessity of social medicine in medical education

Research and clinical experience reliably and repeatedly demonstrate that the determinants of health are most accurately conceptualized as biosocial phenomena, in which health and disease emerge through the interaction between biology and the social environment. Increased appreciation of biosocial approaches have already driven change in premedical education and focused attention on population health in current U.S. health care reform. Medical education, however, places primary emphasis on biomedicine and often fails to emphasize and educate students and trainees about the social forces that shape disease and illness patterns. The authors of this Commentary argue that medical education requires a comprehensive transformation to incorporate rigorous biosocial training to ensure that all future health professionals are equipped with the knowledge and skills necessary to practice social medicine. Three distinct models for accomplishing such transformation are presented: SocMed's monthlong, elective courses in Northern Uganda and Haiti; Harvard Medical School's semester-long, required social medicine course; and the Lebanese American University's curricular integration of social medicine throughout its entire four-year curriculum. Successful implementation of social medicine training requires the institutionalization of biosocial curricula; the utilization of innovative, engaging pedagogies; and the involvement of health professions students from broad demographic backgrounds and with all career interests. The achievement of such transformational and necessary change to medical education will prepare future health practitioners working in all settings to respond more proactively and comprehensively to the health needs of all populations.

A review of one year of British Armed Forces mental health hospital admissions

OBJECTIVES

The paper provides a review of one year of military Mental Health (MH) hospital admissions. This includes an exploration into demographic trends, differences in clinical opinion and how information gained is used to improve the service and ensure appropriate, cost effective care in the optimum environment.

METHODS

The sample group is entitled military MH hospital admissions from 1 April 2005 to 31 March 2006. Data was collected on questionnaires with SPSS used for the management and analysis of the quantitative data, with the information exposed to descriptive and inferential statistical analysis.

RESULTS

There were 344 admissions. The paper contains a detailed review of a number of variables. Depression was the most common diagnosis resulting in 112 (33%) hospital admissions and Post Traumatic Stress Disorder accounted for 23 (7%). There were statistically significant differences that may be attributable to gender with more women admitted with depression and more men with alcohol related disorders. The average length of stay was 21 days, with 48% of patients discharged within 3 weeks. 45% of all returns included significant events reporting that highlighted written evidence of good and poor practice.

CONCLUSION

This study is part of an extensive monitoring programme of military MH hospital admissions. Depression is the most common MH problem leading to hospital admission. The results indicate that Service-personnel have access to a highly responsive service that provides brief assessment and treatment within a safe therapeutic environment. 45% of returns included significant event information that resulted in policy changes, leading to improved patient care and a better interface with the NHS. Bench-marking, both internally between military Departments of Community Mental Health and externally have improved visibility and self awareness leading to better GP induction programmes, PHC educational seminars and the establishment of MH web-pages. The Armed Forces need an effective MH service that is accessible, readily available, non-stigmatised and which positively advocates a duty of care. The results highlight the importance of further studies regarding depression to ensure that the Armed Forces are in a better position to maximise the use of MH resources.

Disease-associated qualitative and quantitative trait loci in proteoglycan-induced arthritis and collagen-induced arthritis

Two autoimmune murine models--proteoglycan (aggrecan)-induced arthritis (PGIA) and collagen-induced arthritis (CIA)--were developed in parent strains, F1 and F2 hybrids of major histocompatibility complex (MHC)-matched (H-2) BALB/c x DBA/2 and MHC-unmatched (H-2/H-2) BALB/c x DBA/1 intercrosses. The major goal of this comparative study was to identify disease (model)-specific (PGIA or CIA) and shared clinical and immunologic loci in 2 types of genetic intercrosses. Qualitative (binary/susceptibility) and quantitative (severity and onset) clinical trait loci were separated and analyzed independently or together with various pathophysiologic/immunologic traits, such as antigen-specific T- and B-cell responses and cytokine production. The major quantitative trait locus (QTL) was the MHC on chromosome 17, which was especially dominant in CIA. In addition, chromosomes 3, 5, 10, and X contained shared clinical loci in both models, and a total of 8 QTLs (clinical traits together with immunologic traits) were colocalized in PGIA and CIA.

Impaired Fas signaling pathway is involved in defective T cell apoptosis in autoimmune murine arthritis

Proteoglycan (PG)-induced arthritis (PGIA) is a novel autoimmune murine model for rheumatoid arthritis induced by immunization with cartilage PG in susceptible BALB/c mice. In this model, hyperproliferation of peripheral CD4(+) T cells has been observed in vitro with Ag stimulation, suggesting the breakdown of peripheral tolerance. Activation-induced cell death (AICD) is a major mechanism for peripheral T cell tolerance. A defect in AICD may result in autoimmunity. We report in this study that although CD4(+) T cells from both BALB/c and B6 mice, identically immunized with human cartilage PG or OVA, express equally high levels of Fas at the cell surface, CD4(+) T cells from human cartilage PG-immunized BALB/c mice, which develop arthritis, fail to undergo AICD. This defect in AICD in PGIA may lead to the accumulation of autoreactive Th1 cells in the periphery. The impaired AICD in PGIA might be ascribed to an aberrant expression of Fas-like IL-1beta-converting enzyme-inhibitory protein, which precludes caspase-8 activation at the death-inducing signaling complex, and subsequently suppresses the caspase cascade initiated by Fas-Fas ligand interaction. Moreover, this aberrant expression of Fas-like IL-1beta-converting enzyme-inhibitory protein may also mediate TCR-induced hyperproliferation of CD4(+) T cells from arthritic BALB/c mice. Our data provide the first insight into the molecular mechanism(s) of defective AICD in autoimmune arthritis.

Variations in susceptibility to proteoglycan-induced arthritis and spondylitis among C3H substrains of mice: evidence of genetically acquired resistance to autoimmune disease

OBJECTIVE

To identify and screen the level of arthritis susceptibility in C3H murine strains known to be resistant to proteoglycan (aggrecan)-induced arthritis, and to measure and correlate various immunologic and inflammatory parameters with susceptibility to either arthritis or spondylitis in various C3H substrains.

METHODS

Mice of 10 C3H substrains (subcolonies) were immunized with cartilage proteoglycan (aggrecan) for induction of arthritis. Animals were assessed for clinical symptoms, and the peripheral joints and spine were studied by histologic methods. Proteoglycan-specific T cell responses (T cell proliferation and production of interleukin-2 [IL-2], interferon-y, and IL-4) and the B cell response to lipopolysaccharide (LPS) were measured in spleen cell cultures. Serum levels of heteroantibodies and autoantibodies as well as various cytokines (IL-6, IL-10, IL-12, and tumor necrosis factor alpha) and soluble CD44 were determined by enzyme-linked immunosorbent assay.

RESULTS

Immunization with cartilage proteoglycan induced severe arthritis in the C3H/HeJCr substrain (95-100% incidence), whereas the original parent mice of the C3H/HeJ colony were resistant to proteoglycan (aggrecan)-induced arthritis. Furthermore, the progressive polyarthritis that is characteristic in susceptible C3H/HeJCr mice was accompanied by progressive inflammation around the spine. In subsequent experiments, 10 different C3H colonies with largely identical genetic backgrounds (all originating from the National Institutes of Health or Jackson Laboratory) exhibited extreme differences in susceptibility. Although none of the laboratory findings, including LPS hyporesponsiveness, immunologic parameters, and inflammatory markers, showed a correlation with susceptibility or resistance in the C3H/HeJCr and C3H/HeJ substrains, respectively, significant differences were found when all arthritic C3H mice were compared with all nonarthritic animals, regardless of their substrain origin.

CONCLUSION

Because many of the C3H substrains lost arthritis susceptibility or acquired resistance, our results suggest that a preferred site for a mutation(s) in a gene(s) in a relatively upstream position of the inflammatory cascade is present. This is the first autoimmune model that exhibits extreme differences in arthritis susceptibility in the same murine strain, and is therefore a valuable tool for identification of arthritis-susceptible (or arthritis-suppressive) genes.

A genome scan using a novel genetic cross identifies new susceptibility loci and traits in a mouse model of rheumatoid arthritis

Proteoglycan-induced arthritis (PGIA) is a murine model for rheumatoid arthritis (RA) both in terms of its pathology and its genetics. PGIA can only be induced in susceptible mouse strains and their F(2) progeny. Using the F(2) hybrids resulting from an F(1) intercross of a newly identified susceptible (C3H/HeJCr) and an established resistant (C57BL/6) strain of mouse, our goals were to: 1) identify the strain-specific loci that confer PGIA susceptibility, 2) determine whether any pathophysiological parameters could be used as markers that distinguish between nonarthritic and arthritic mice, and 3) analyze the effect of the MHC haplotype on quantitative trait loci (QTL) detection. To identify QTLs, we performed a genome scan on the F(2) hybrids. For pathophysiological analyses, we measured pro- and antiinflammatory cytokines such as IL-1, IL-6, IFN-gamma, IL-4, IL-10, IL-12, Ag-specific T cell proliferation and IL-2 production, serum IgG1 and IgG2 levels of both auto- and heteroantibodies, and soluble CD44. We have identified four new PGIA-linked QTLs (Pgia13 through Pgia16) and confirmed two (Pgia5, Pgia10) from our previous study. All new MHC-independent QTLs were associated with either disease onset or severity. Comprehensive statistical analysis demonstrated that while soluble CD44, IL-6, and IgG1 vs. IgG2 heteroantibody levels differed significantly between the arthritic and nonarthritic groups, only Ab-related parameters colocalized with the QTLs. Importantly, the mixed haplotype (H-2(b) and H-2(k)) of the C3H x C57BL/6 F(2) intercross reduced the detection of several previously identified QTLs to suggestive levels, indicating a masking effect of unmatched MHCs.

Spontaneous thymocyte apoptosis is regulated by a mitochondrion-mediated signaling pathway

Most thymocytes that have not successfully rearranged their TCR genes or that express a receptor with subthreshold avidity for self-Ag/MHC enter a default apoptosis pathway, death by neglect. Spontaneous thymocyte apoptosis (STA), at least in part, may mimic this process in vitro. However, the molecular mechanism(s) by which thymocytes undergo this spontaneous apoptosis remains unknown. Here, we report that caspsase-1 and caspase-3 are activated during STA, but these caspases are dispensable for this apoptotic process. The inhibition of STA by a pan-caspase inhibitor, zVAD, suggests that multiple caspase pathways exist. Importantly, the early release of cytochrome c from mitochondria closely correlates with the degradation of Bcl-2 and Bcl-xL and a decrease in the ratios of Bcl-2 and Bcl-xL to Bax during STA. These findings suggest that the degradation of Bcl-2 and Bcl-xL may favor Bax to induce cytochrome c release from mitochondria, which subsequently activates downstream caspases in STA. Our data provide the first biochemical insight into the molecular mechanism of STA.

Complex pattern of Th1 and Th2 activation with a preferential increase of autoreactive Th1 cells in BALB/c mice with proteoglycan (aggrecan)-induced arthritis

The central role of CD4+ T cells and the balance between T helper (Th) subpopulations in the pathogenesis of autoimmune diseases have been extensively studied. Proteoglycan (aggrecan)-induced arthritis (PGIA) is a murine model for rheumatoid arthritis (RA), which is characterized by a Th1 dominance at the onset of the disease. In addition to CD4+ T cells, antigen-presenting B cells and autoantibodies seem to play an important role in the development and regulation of PGIA. To identify proteoglycan-specific CD4+ T cell subsets and Th1- and Th2-supported antibody isotypes during the progression of PGIA, spleen cells of proteoglycan-immunized BALB/c mice were harvested at different times of immunization, and at different stages of the disease, and their cytokine production and antigen-specific antibody isotype profiles were determined by enzyme-linked immunospot (ELISPOT) assays. Both Th1 and Th2 cytokine-producing cells, with the predominance of IL-4/IL-5-secreting cells, were detected during the prearthritic stage, and a shift toward a Th1 dominance was observed at the time of onset of arthritis. Tissue homogenates of acutely inflamed joints contained significantly higher levels of interferon-gamma than IL-4. The prearthritic period and both the acute and chronic phases of joint inflammation were characterized by IgG1 dominance in the sera and this correlated with the number of IgG1-secreting B cells in the spleen. However, the ratio of autoreactive IgG1/IgG2a-secreting cells decreased in arthritic animals. These results indicate the activation and possible regulatory roles of both Th1 and Th2 subsets in the autoimmune process, with the necessity of a relative increase of autoreactive Th1 cells for the induction of joint inflammation.

Regulation of intercellular adhesion molecule-1 (CD54) gene expression

Intercellular adhesion molecule-1 (ICAM-1, CD54) is an inducible cell adhesion glycoprotein of the immunoglobulin supergene family expressed on the surface of a wide variety of cell types. ICAM-1 interactions with the beta2 integrins CD11a/CD18 (LFA-1) and CD11b/CD18 (MAC-1) on the surface of leukocytes are important for their transendothelial migration to sites of inflammation and their function as costimulatory molecules for T cell activation. ICAM-1 is constitutively expressed on the cell surface and is up-regulated in response to a variety of inflammatory mediators, including proinflammatory cytokines, hormones, cellular stresses, and virus infection. These stimuli increase ICAM-1 expression primarily through activation of ICAM-1 gene transcription. During the past decade much has been learned about the cell type- and stimulus-specific transcription of ICAM-1. The architecture of the ICAM-1 promoter is complex, containing a large number of binding sites for inducible transcription factors, the most important of which is nuclear factor-kappa B (NF-kappaB). NF-kappaB acts in concert with other transcription factors and co-activators via specific protein-protein interactions, which facilitate the assembly of distinct stereospecific transcription complexes on the ICAM-1 promoter. These transcription complexes presumably mediate the induction of ICAM-1 expression in different cell types and in response to different stimuli. In this review, we summarize our current understanding of ICAM-1 gene regulation with a particular emphasis on the transcription factors and signal transduction pathways critical for the cell type- and stimulus-specific activation of ICAM-1 gene transcription.

A mental health service after major trauma

Although 75-80% of people involved in a major trauma do not have any long-term psychological problems, many will experience significant psychological distress during the first four weeks. Most individuals will make a full recovery if provided with local, immediate and appropriate support. People who have experienced a major trauma should have access to support as soon as possible after the event until symptoms are resolved.

Proteoglycan (aggrecan)-induced arthritis in BALB/c mice is a Th1-type disease regulated by Th2 cytokines

In animal models of arthritis induced with Ags or infectious agents, disease severity correlates with a dominant Th1-type response characterized by a higher ratio of IFN-gamma to IL-4. Analysis of BALB/c mice revealed a genetic predisposition toward developing CD4+ Th2-type responses. The bias toward an IL-4-dominant response in BALB/c mice protects mice from severe Lyme-induced arthritis and spontaneous autoimmune disease. Since BALB/c mice immunized with proteoglycan develop severe arthritis, we were interested in testing whether arthritis is associated with a Th2-type response and thus is different from other arthritic models. BALB/c mice immunized with proteoglycan generated a higher ratio of IFN-gamma to IL-4 that peaks at the onset of arthritis. We investigated whether when Th1 cells were dominant, disease outcome could be modified with pharmacological amounts of Th2 cytokines. Treatment with IL-4 prevented disease and induced a switch from a Th1-type to a Th2-type response. Proinflammatory cytokine mRNA transcripts were reduced in joints of cytokine-treated mice. Th2 cytokine therapy at the time of maximum joint inflammation also suppressed symptoms of disease. Despite the predisposition of BALB/c mice to a Th2-type response, proteoglycan-induced arthritis is a Th1-type disease. The effectiveness of IL-4 treatment was particularly striking because in other models of arthritis, treatment in a similar manner with IL-4 was not sufficient to inhibit arthritis. The effective control of arthritis and the switch from a Th1 to Th2 response suggest that levels of endogenous IL-4 in BALB/c mice may increase their responsiveness to Th2 cytokine therapy.

Interleukin-10 enhances tumor necrosis factor-alpha activation of HIV-1 transcription in latently infected T cells

Interleukin-10 (IL-10) is elevated in HIV-1-infected individuals and has been implicated in disease progression. We previously reported that IL-10 cooperates with tumor necrosis factor-alpha (TNF-alpha) to activate HIV-1 expression synergistically in acutely infected monocyte-derived macrophages and the chronically infected U1 promonocytic cell line. To determine whether IL-10 also cooperates with TNF-alpha to activate latent HIV-I expression in lymphocytes, we examined the effects of IL-10 on proviral expression in the chronically infected T-cell line, ACH-2. Although IL-10 inhibited HIV-1 expression acting alone, in combination with suboptimal concentrations of TNF-alpha, IL-10 increased HIV-1 steady-state mRNA expression and p24 core antigen production in ACH-2 cells. Interestingly, IL-10 concentrations that synergistically induced virus also maximally stimulated endogenous TNF-alpha expression, suggesting that cell-derived TNF-alpha may contribute to cytokine synergy. Transfection studies in ACH-2 cells indicated that IL-10 combined with TNF-alpha to activate the HIV-1 long terminal repeat (LTR). IL-10 also cooperated with TNF-alpha to activate HIV-1 LTR in 1G5 cells, a Jurkat T-cell line stably transfected with an LTR-dependent luciferase reporter gene. Pyrrolidine dithiocarbamate, a potent transcriptional inhibitor of the viral LTR, abrogated the cytokine responses in both U1 and ACH-2 cells, suggesting a common TNF-alpha-mediated transcriptional mechanism in these cell types despite their different modes of provirus latency. Taken collectively, these data suggest that IL-10 enhances suboptimal TNF-alpha activation of HIV-1 transcription in chronically infected T-cells at least in part through induction of endogenous TNF-alpha expression.

Critical roles of glycosaminoglycan side chains of cartilage proteoglycan (aggrecan) in antigen recognition and presentation

Systemic immunization of BALB/c mice with proteoglycan (aggrecan) from fetal human cartilage induces progressive polyarthritis, an experimental disease similar to human rheumatoid arthritis. The development of the disease in this genetically susceptible murine strain is based on cross-reactive immune responses between the immunizing fetal human and mouse self-proteoglycans. One of the cross-reactive and arthritogenic T cell epitopes (92GR/QVRVNSA/IY) is localized in the G1 domain of human/murine proteoglycan. Susceptible BALB/c mice, however, develop arthritis only if both the chondroitin sulfate (CS) and keratan sulfate (KS) side chains of the arthritogenic human proteoglycans are removed. The function of these two glycosaminoglycan side chains is opposite. The presence of a KS side chain in adult proteoglycan inhibits the recognition of arthritogenic T cell epitopes, prevents the development of T cell response, and protects animals from autoimmune arthritis. In contrast, the depletion of the CS side chain generates clusters of CS stubs and provokes a strong B cell response. These carbohydrate-specific B cells are the most important proteoglycan APC. Taken together, proteoglycan-induced progressive polyarthritis is dictated by three major components: genetic background of the BALB/c strain, highly specific T cell response to epitope(s) masked by a KS chain in aging tissue, and the presence of proteoglycan (CS stub)-specific B cells required for sufficient Ag presentation.

Inhibition of JAK3 and STAT6 tyrosine phosphorylation by the immunosuppressive drug leflunomide leads to a block in IgG1 production

Leflunomide is an immunosuppressive drug capable of inhibiting T and B cell responses in vivo. A number of studies demonstrate that leflunomide functions both as a pyrimidine synthesis inhibitor and as a tyrosine kinase inhibitor. We previously reported that leflunomide inhibits LPS-stimulated B cell proliferation, cell cycle progression, and IgM secretion. This inhibition can be reversed by the addition of exogenous uridine, suggesting that leflunomide functions as a pyrimidine synthesis inhibitor in B cells. We report here that while the addition of uridine restored proliferation and IgM secretion to leflunomide-treated LPS-stimulated B cells, as determined by metabolic labeling and immunoprecipitation, it did not completely restore secretion of IgG Ab. We hypothesized that leflunomide inhibits LPS-induced IgG secretion by inhibiting tyrosine kinase activity required for isotype switch. We tested this hypothesis in a well-defined model of isotype switch, LPS plus IL-4 induction of IgG1. Leflunomide inhibited IgG1 secretion in this model in a dose-dependent manner. The signal transduction pathway utilized by IL-4 to induce IgG1 involves tyrosine phosphorylation of the IL-4 receptor, JAK1, JAK3, and STAT6 proteins induced by IL-4 binding to the IL-4R. Leflunomide diminished the tyrosine phosphorylation of JAK3 and STAT6 in the absence or presence of uridine. In gel mobility shift studies, STAT6 binding to the STAT6 DNA binding site in the IgG1 promoter decreased in the presence of leflunomide or leflunomide plus uridine. Taken together, these data suggest that leflunomide acts as a tyrosine kinase inhibitor to block IgG1 production.

In vitro and in vivo mechanisms of action of the antiproliferative and immunosuppressive agent, brequinar sodium

Intracellular pyrimidine nucleotides (PyN) can be synthesized de novo from glutamine, CO2, and ATP, or they can be salvaged from preformed pyrimidine nucleosides. The antiproliferative and immunosuppressive activities of brequinar sodium (BQR) are thought to be due to the inhibition of the activity of dihydroorotate dehydrogenase, which results in a suppression of de novo pyrimidine synthesis. Here we describe the effects of the pyrimidine nucleoSide, uridine, on the antiproliferative and immunosuppressive activities of BQR. In vitro reduction of PyN levels in Con A-stimulated T cells and inhibition of cell proliferation by low concentrations of BQR (< or =65 microM) are reversed by uridine. However, uridine is unable to reverse the effects of high concentrations of BQR (> or =65 microM). The ability of BQR to induce anemia in BALB/c mice is prevented by the coadministration of uridine. In contrast, the immunosuppressive activity of BQR is unaffected by similar doses of uridine. PyN levels in the bone marrow, but not in the spleen, are depressed in mice treated with BQR. These observations suggest that the induction of anemia by BQR is due to depletion of intracellular PyN in hemopoietic stem cells located in the bone marrow. They also suggest that the mechanism of immunosuppression by BQR may be only marginally dependent on depletion of intracellular PyN in lymphocytes located in the periphery. We report a novel activity of BQR: inhibition of tyrosine phosphorylation, and hypothesize that the immunosuppressive activity may be due, in part, to this unsuspected ability of BQR to inhibit tyrosine phosphorylation in lymphocytes.

In vivo mechanism by which leflunomide controls lymphoproliferative and autoimmune disease in MRL/MpJ-lpr/lpr mice

Two activities have been identified for the immunosuppressive metabolite of leflunomide, A77 1726: inhibition of dihydroorotate dehydrogenase (DHO-DHase), an enzyme involved in the biosynthesis of pyrimidine nucleotides (PyN); and inhibition of protein tyrosine kinases. The in vitro potency of A77 1726 as a DHO-DHase inhibitor is reported to be 10- to 500-fold greater than as a tyrosine kinase inhibitor. These observations suggested that the immunosuppressive efficacy of leflunomide in vivo is related to inhibition of DHO-DHase. However, observations that patients with disorders in the PyN synthetic pathway are not overtly immunodeficient militate against this hypothesis. We investigated the effects of leflunomide in vivo and report that amelioration of lymphoproliferative and autoimmune diseases in MRL/MpJ-lpr/lpr (lpr/lpr) mice by leflunomide is not accompanied by reduced PyN concentrations in lymph node cells. Our hypothesis that lymphocytes could salvage serum uridine to counter the effects of reduced PyN synthesis in vivo was supported by in vitro studies. Finally, we observed that amelioration of disease correlated with a reduction of tyrosine phosphorylated proteins in lymph node cells of lpr/lpr mice. These observations suggest that the primary mechanism by which leflunomide prevents autoimmune and lymphoproliferative diseases in lpr/lpr mice is not depletion of PyN, but correlates with reduced tyrosine phosphorylation concentrations in lymph node cells.

In vivo mechanism by which leflunomide controls lymphoproliferative and autoimmune disease in MRL/MpJ-lpr/lpr mice

Two activities have been identified for the immunosuppressive metabolite of leflunomide, A77 1726: inhibition of dihydroorotate dehydrogenase (DHO-DHase), an enzyme involved in the biosynthesis of pyrimidine nucleotides (PyN); and inhibition of protein tyrosine kinases. The in vitro potency of A77 1726 as a DHO-DHase inhibitor is reported to be 10- to 500-fold greater than as a tyrosine kinase inhibitor. These observations suggested that the immunosuppressive efficacy of leflunomide in vivo is related to inhibition of DHO-DHase. However, observations that patients with disorders in the PyN synthetic pathway are not overtly immunodeficient militate against this hypothesis. We investigated the effects of leflunomide in vivo and report that amelioration of lymphoproliferative and autoimmune diseases in MRL/MpJ-lpr/lpr (lpr/lpr) mice by leflunomide is not accompanied by reduced PyN concentrations in lymph node cells. Our hypothesis that lymphocytes could salvage serum uridine to counter the effects of reduced PyN synthesis in vivo was supported by in vitro studies. Finally, we observed that amelioration of disease correlated with a reduction of tyrosine phosphorylated proteins in lymph node cells of lpr/lpr mice. These observations suggest that the primary mechanism by which leflunomide prevents autoimmune and lymphoproliferative diseases in lpr/lpr mice is not depletion of PyN, but correlates with reduced tyrosine phosphorylation concentrations in lymph node cells.

The immunosuppressive metabolite of leflunomide, A77 1726, affects murine T cells through two biochemical mechanisms

The immunosuppressive metabolite of leflunomide, A77 1726, inhibits the enzymatic activity of protein tyrosine kinases and of dihydro-orotic acid dehydrogenase, an enzyme involved in pyrimidine biosynthesis. Here murine CTLL cell lines were studied to determine which of the biochemical targets of A77 1726 was responsible for the observed inhibition of proliferation and cytotoxic activity. At low concentrations of A77 1726, pyrimidine biosynthesis is the target, since inhibition of proliferation correlates with a reduction in pyrimidine NTP levels and is reversed by uridine. At higher concentrations of A77 1726, uridine no longer reverses the inhibition of proliferation even though pyrimidine NTP levels are restored. This second mechanism for inhibiting proliferation is probably inhibition of protein tyrosine kinases, since these higher concentrations of A77 1726 inhibit IL-2-induced tyrosine phosphorylation of Jak1 and Jak3, the protein tyrosine kinases initiating signaling by the IL-2R. Tyrosine phosphorylation of the beta-chain of the IL-2R, which is required for IL-2-driven proliferation, is also inhibited by A77 1726. Cytotoxicity of a CTLL line that overexpresses the Lck protein tyrosine kinase is inhibited by A77 1726; this inhibition is not affected by uridine, but does correlate with inhibition of an Lck in vitro kinase reaction. These studies establish that inhibition of pyrimidine biosynthesis and that of protein tyrosine kinase both contribute to the effects of A77 1726 on CTLL cell lines.

The immunosuppressive metabolite of leflunomide, A77 1726, affects murine T cells through two biochemical mechanisms

The immunosuppressive metabolite of leflunomide, A77 1726, inhibits the enzymatic activity of protein tyrosine kinases and of dihydro-orotic acid dehydrogenase, an enzyme involved in pyrimidine biosynthesis. Here murine CTLL cell lines were studied to determine which of the biochemical targets of A77 1726 was responsible for the observed inhibition of proliferation and cytotoxic activity. At low concentrations of A77 1726, pyrimidine biosynthesis is the target, since inhibition of proliferation correlates with a reduction in pyrimidine NTP levels and is reversed by uridine. At higher concentrations of A77 1726, uridine no longer reverses the inhibition of proliferation even though pyrimidine NTP levels are restored. This second mechanism for inhibiting proliferation is probably inhibition of protein tyrosine kinases, since these higher concentrations of A77 1726 inhibit IL-2-induced tyrosine phosphorylation of Jak1 and Jak3, the protein tyrosine kinases initiating signaling by the IL-2R. Tyrosine phosphorylation of the beta-chain of the IL-2R, which is required for IL-2-driven proliferation, is also inhibited by A77 1726. Cytotoxicity of a CTLL line that overexpresses the Lck protein tyrosine kinase is inhibited by A77 1726; this inhibition is not affected by uridine, but does correlate with inhibition of an Lck in vitro kinase reaction. These studies establish that inhibition of pyrimidine biosynthesis and that of protein tyrosine kinase both contribute to the effects of A77 1726 on CTLL cell lines.

Interleukin-10 inhibits interferon-gamma-induced intercellular adhesion molecule-1 gene transcription in human monocytes

Interleukin-10 (IL-10) is a potent monocyte regulatory cytokine that inhibits gene expression of proinflammatory mediators. In this study, we investigated the mechanism by which IL-10 downregulates expression of intercellular adhesion molecule-1 (ICAM-1) on the cell surface of normal human monocytes activated with interferon-gamma (IFN-gamma). IL-10 inhibition of IFN-gamma-induced ICAM-1 expression was apparent as early as 3 hours and was blocked by an anti-IL-10 antibody but not by an isotype-matched control antibody. Northern blot analysis showed that IL-10 reduced the accumulation of ICAM-1 mRNA in IFN-gamma-stimulated monocytes. IL-10 inhibition of ICAM-1 steady-state mRNA was detected at 3 hours and remained at 24 hours. Nuclear run-on transcription assays showed that IL-10 inhibited the rate of IFN-gamma-induced transcription of the ICAM-1 gene, and mRNA stability studies showed that IL-10 did not alter the half-life of IFN-gamma-induced ICAM-1 message. Thus, IL-10 inhibits IFN-gamma-induced ICAM-1 expression in monocytes primarily at the level of gene transcription. Activation of IFN-gamma-responsive genes requires tyrosine phosphorylation of the transcriptional factor STAT-1alpha (signal transducer and activator of transcription-1alpha). However, IL-10 did not affect IFN-gamma-induced tyrosine phosphorylation of STAT-1alpha or alter STAT-1alpha binding to the IFN-gamma response element (IRE) in the ICAM-1 promoter. Instead, IL-10 prevented IFN-gamma-induced binding activity at the NF-kappaB site of the tumor necrosis factor alpha (TNF-alpha)-responsive NF-kappaB/C-EBP composite element in the ICAM-1 promoter. These data indicate that IL-10 inhibits IFN-gamma-induced transcription of the ICAM-1 gene by a regulatory mechanism that may involve NF-kappaB.

The immunodominant region of Staphylococcal nuclease is represented by multiple peptide sequences

Several published reports have lead to the characterization of naturally processed peptides that are presented in association with either class I or class II MHC molecules. Most peptides isolated from class II molecules are heterogeneous in length and exhibit ragged amino and carboxy termini. An intriguing finding was that one region of a molecule was often represented by many distinct peptides, rather than by a single dominant peptide species. Each of the peptides representing this dominant region exhibited a common core of amino acids, suggesting that this core may play a significant role in the binding of the peptide to class II and the recognition by peptide-specific T cells. Work from our laboratory has focused on the mechanisms involved in the immunodominance of antigenic determinants using the bacterial antigen Staphylococcal nuclease (Nase) as a model. Using truncated synthetic peptides, we have identified the immunodominant determinant of Nase to be located within the region 81-100 with a minimal antigenic core of 91-100 as determined. Addition of five residues to the carboxy terminus of this peptide had a negative effect on T cell recognition of this region. The present studies were undertaken in an effort to determine the sequence of the naturally processed immunodominant Nase determinant(s) presented in association with I-Ek class II. Our results indicate that the dominant region of the Nase molecule is represented by at least four distinct peptide species that are predicted to lie between residues 86 and 106 with a common core sequence of 91-96. These results indicate that the negative effects of flanking regions are dependent upon length and amino acid composition, and thus the use of truncated peptides to study minimal antigenic determinants may be misleading.