Interprofessional Curriculum Delivery: Experience of a Primary Care Education Program

Few post-graduate training programs offer a comprehensive curriculum that includes structured clinical experiences to teach interprofessional care. To address this need, the United States Department of Veterans Affairs, Office of Academic Affiliations funded the Centers of Excellence in Primary Care Education (CoEPCE) from 2011-2019 to provide interprofessional curricula for health profession trainees (HPTs), including physician residents, nurse practitioner residents, pharmacy residents, and psychology residents. We examined changes over time in curricular domains, system impacts, and program practices based on HPT survey data and the qualitative evaluation of narrative feedback. An annual survey was administered to participants. Indirect standardized ratios were calculated for interprofessional professional education (IPE) program domains, system impacts, and program practices. Qualitative responses were coded based on curricular domains and key program components. The study cohort included 369 HPTs. Site and profession standardized indirect ratios across all professions indicated improvements in curricular domains, system impacts, and program practices, with significant differences observed for associated health HPTs as compared to other HPTs for performance improvement. Qualitative data indicated that profession was associated with differences in perceptions of the curriculum. Although improvements occurred over time, our findings support the need for the thoughtful consideration of profession-specific identity characteristics when designing interprofessional curricula.

Interprofessional transformation of clinical education: The first six years of the Veterans Affairs Centers of Excellence in Primary Care Education

This paper describes the Centers of Excellence in Primary Care Education (CoEPCE), a seven-site collaborative project funded by the Office of Academic Affiliations (OAA) within the Veterans Health Administration of the United States Department of Veterans Affairs (VA). The CoEPCE was established to fulfill OAA's vision of large-scale transformation of the clinical learning environment within VA primary care settings. This was accomplished by funding new Centers within VA facilities to develop models of interprofessional education (IPE) to teach health professions trainees to deliver high quality interprofessional team-based primary care to Veterans. Using reports and data collected and maintained by the National Coordinating Center over the first six years of the project, we describe program inputs, the multicomponent intervention, activities undertaken to develop the intervention, and short-term outcomes. The findings have implications for lessons learned that can be considered by others seeking large-scale transformation of education within the clinical workplace and the development of interprofessional clinical learning environments. Within the VA, the CoEPCE has laid the foundation for IPE and collaborative practice, but much work remains to disseminate this work throughout the national VA system.

Impact of clinical training on recruiting graduating health professionals

OBJECTIVES

Recruiting professional staff is an important business reason for hospitals allowing health trainees to engage in supervised patient care. Whereas prior studies have focused on educational institutions, this study focuses on teaching hospitals and whether trainees' clinical experiences affect their willingness to work (ie, recruitability) for the type of healthcare center where they trained.

STUDY DESIGN

A pre-post, observational study based on Learners' Perceptions Survey data in which respondents served as their own controls.

METHODS

Convenience sample of 15,207 physician, 11,844 nursing, and 13,012 associated health trainees who rotated through 1 of 169 US Department of Veterans Affairs (VA) medical centers between July 1, 2014, and June 30, 2017. Generalized estimating equations computed how clinical, learning, working, and cultural experiences influenced pre-post differences in willingness to consider VA for future employment.

RESULTS

VA recruitability increased dramatically from 55% pretraining to 75% post training (adjusted odds ratio [OR], 2.1; 95% CI, 2.0-2.1; P <.001) in all 3 cohorts: physician (from 39% to 59%; OR, 1.6; 95% CI, 1.5-1.6; P <.001), nursing (from 61% to 84%; OR, 2.5; 95% CI, 2.4-2.6; P <.001), and associated health trainees (from 68% to 87%; OR, 2.7; 95% CI, 2.6-2.9; P <.001). For all trainees, changes in recruitability (P <.001) were associated with how trainees rated their clinical learning environment, personal experiences, and culture of psychological safety. Satisfaction ratings with faculty and preceptors (P <.001) were associated with positive changes in recruitability among nursing and associated health students but not physician residents, whereas nursing students who gave higher ratings for interprofessional team culture became less recruitable.

CONCLUSIONS

Academic medical centers can attract their health trainees for future employment if they provide positive clinical, working, learning, and cultural experiences.

Developing Interprofessional Primary Care Teams: Alumni Evaluation of the Department of Veterans Affairs Centers of Excellence in Primary Care Education Program

PURPOSE

The Centers of Excellence in Primary Care Education (CoEPCE) is an interprofessional graduate training program within the Department of Veterans Affairs (VA). In this project, we describe career paths of CoEPCE graduates, their perceptions of CoEPCE program value, their overall satisfaction with the training, and suggestions for program improvement to enhance interprofessional education and workforce development.

METHODS

The Graduate Participant Survey was developed and administered in 2018 to CoEPCE graduates from 2012 to 2017. Quantitative data from closed-ended questions were analyzed through descriptive and non-parametric statistics to test for significant differences by profession. Qualitative data from the single open-ended question were analyzed using content analysis with inductive and deductive approaches.

RESULTS

The survey was completed by 180 graduates. Greater proportions of pharmacists and psychologists than nurse practitioners and physicians were employed in VA, and greater proportions of nurse practitioners and pharmacists than physicians and psychologists were employed in primary care. Although smaller proportions of physicians were currently employed in primary care (P < .0001), a greater proportion completed advanced training programs (P < .0001). Overall, graduates perceived that their CoEPCE training was highly valued by advanced training programs and employers and improved their chances of finding a job. They reported high levels of satisfaction (mean = 4.3 ± 0.9 out of 5 total) with the training program, continued to use skills they learned during training, and believe their CoEPCE experiences made them better health care providers.

CONCLUSIONS

Ninety-four percent of the CoEPCE graduates were employed at the VA and/or primary care at the completion of their training, although there were significant differences by profession. Graduates continued to practice interprofessional skills learned during their training and were highly satisfied with the program. Taken together, the findings indicate that continued enhancements to the interprofessional clinical learning environment are warranted.

Has Interprofessional Education Changed Learning Preferences? A National Perspective

OBJECTIVE

To assess how changes in curriculum, accreditation standards, and certification and licensure competencies impacted how medical students and physician residents value interprofessional team and patient-centered care.

PRIMARY DATA SOURCE

The Department of Veterans Affairs Learners' Perceptions Survey (2003-2013). The nationally administered survey asked a representative sample of 56,569 U.S. medical students and physician residents, with a comparison group of 78,038 nonphysician trainees, to rate satisfaction with 28 elements, in two overall domains, describing their clinical learning experiences at VA medical centers.

STUDY DESIGN

Value preferences were scored as independent adjusted associations between an element (interprofessional team, patient-centered preceptor) and the respective overall domain (clinical learning environment, faculty, and preceptors) relative to a referent element (quality of clinical care, quality of preceptor).

PRINCIPAL FINDINGS

Physician trainees valued interprofessional (14 percent vs. 37 percent, p < .001) and patient-centered learning (21 percent vs. 36 percent, p < .001) less than their nonphysician counterparts. Physician preferences for interprofessional learning showed modest increases over time (2.5 percent/year, p < .001), driven mostly by internal medicine and surgery residents. Preferences did not increase with trainees' academic progress.

CONCLUSIONS

Despite changes in medical education, physician trainees continue to lag behind their nonphysician counterparts in valuing experience with interprofessional team and patient-centered care.

Connecting the dots: interprofessional health education and delivery system redesign at the Veterans Health Administration

Health systems around the United States are embracing new models of primary care using interprofessional team-based approaches in pursuit of better patient outcomes, higher levels of satisfaction among patients and providers, and improved overall value. Less often discussed are the implications of new models of care for health professions education, including education for physicians, nurse practitioners, physician assistants, and other professions engaged in primary care. Described here is the interaction between care transformation and redesign of health professions education at the largest integrated delivery system in the United States: the Veterans Health Administration (VA). Challenges and lessons learned are discussed in the context of a demonstration initiative, the VA Centers of Excellence in Primary Care Education. Five sites, involving VA medical centers and their academic affiliates in Boise, Cleveland, San Francisco, Seattle, and West Haven, introduced interprofessional primary care curricula for resident physicians and nurse practitioner students beginning in 2011. Implementation struggles largely revolved around the operational logistics and cultural disruption of integrating educational redesign for medicine and nursing and facilitating the interface between educational and clinical activities. To realize new models for interprofessional teaching, faculty, staff, and trainees must understand the histories, traditions, and program requirements across professions and experiment with new approaches to achieving a common goal. Key recommendations for redesign of health professions education revolve around strengthening the union between interprofessional learning, team-based practice, and high-value care.

Health systems engineering fellowship: curriculum and program development

Industrial engineering and related disciplines have been used widely in improvement efforts in many industries. These approaches have been less commonly attempted in health care. One factor limiting application is the limited workforce resulting from a lack of specific education and professional development in health systems engineering (HSE). The authors describe the development of an HSE fellowship within the United States Department of Veterans Affairs, Veterans Health Administration (VA). This fellowship includes a novel curriculum based on specifically established competencies for HSE. A 1-year HSE curriculum was developed and delivered to fellows at several VA engineering resource centers over several years. On graduation, a majority of the fellows accepted positions in the health care field. Challenges faced in developing the fellowship are discussed. Advanced educational opportunities in applied HSE have the potential to develop the workforce capacity needed to improve the quality of health care.

The learners' perceptions survey-primary care: assessing resident perceptions of internal medicine continuity clinics and patient-centered care

BACKGROUND

In 2010, the Department of Veterans Affairs (VA) implemented a national patient-centered care initiative that organized primary care into interdisciplinary teams of health care professionals to provide patient-centered, continuous, and coordinated care.

OBJECTIVE

We assessed the discriminate validity of the Learners' Perceptions Survey-Primary Care (LPS-PC), a tool designed to measure residents' perceptions about their primary and patient-centered care experiences.

METHODS

Between October 2010 and June 2011, the LPS-PC was administered to Loma Linda University Medical Center internal medicine residents assigned to continuity clinics at the VA Loma Linda Healthcare System (VALLHCS), a university setting, or the county hospital. Adjusted differences in satisfaction ratings across settings and over domains (patient- and family-centered care, faculty and preceptors, learning, clinical, work and physical environments, and personal experience) were computed using a generalized linear model.

RESULTS

Our response rate was 86% (77 of 90). Residents were more satisfied with patient- and family-centered care at the VALLHCS than at either the university or county (P < .001). However, faculty and preceptors (odds ratio [OR]  =  1.53), physical (OR  =  1.29), and learning (OR  =  1.28) environments had more impact on overall resident satisfaction than patient- and family-centered care (OR  =  1.08).

CONCLUSIONS

The LPS-PC demonstrated discriminate validity to assess residents' perceptions of their patient-centered clinical training experience across outpatient primary care settings at an internal medicine residency program. The largest difference in scores was the patient- and family-centered care domain, in which residents rated the VALLHCS much higher than the university or county sites.

Veteran Affairs Centers of Excellence in Primary Care Education: transforming nurse practitioner education

To integrate health care professional learners into patient-centered primary care delivery models, the Department of Veterans Affairs has funded five Centers of Excellence in Primary Care Education (CoEPCEs). The main goal of the CoEPCEs is to develop and test innovative structural and curricular models that foster transformation of health care training from profession-specific "silos" to interprofessional, team-based educational and care delivery models in patient-centered primary care settings. CoEPCE implementation emphasizes four core curricular domains: shared decision making, sustained relationships, interprofessional collaboration, and performance improvement. The structural models allow interprofessional learners to have longitudinal learning experiences and sustained and continuous relationships with patients, faculty mentors, and peer learners. This article presents an overview of the innovative curricular models developed at each site, focusing on nurse practitioner (NP) education. Insights on transforming NP education in the practice setting and its impact on traditional NP educational models are offered. Preliminary outcomes and sustainment examples are also provided.

Training satisfaction for subspecialty fellows in internal medicine: findings from the Veterans Affairs (VA) Learners' Perceptions Survey

BACKGROUND

Learner satisfaction assessment is critical in the design and improvement of training programs. However, little is known about what influences satisfaction and whether trainee specialty is correlated. A national comparison of satisfaction among internal medicine subspecialty fellows in the Department of Veterans Affairs (VA) provides a unique opportunity to examine educational factors associated with learner satisfaction. We compared satisfaction across internal medicine fellows by subspecialty and compared factors associated with satisfaction between procedural versus non-procedural subspecialty fellows, using data from the Learners' Perceptions Survey (LPS), a validated survey tool.

METHODS

We surveyed 2,221 internal medicine subspecialty fellows rotating through VA between 2001 and 2008. Learners rated their overall training satisfaction on a 100-point scale, and on a five-point Likert scale ranked satisfaction with items within six educational domains: learning, clinical, working and physical environments; personal experience; and clinical faculty/preceptor.

RESULTS

Procedural and non-procedural fellows reported similar overall satisfaction scores (81.2 and 81.6). Non-procedural fellows reported higher satisfaction with 79 of 81 items within the 6 domains and with the domain of physical environment (4.06 vs. 3.85, p <0.001). Satisfaction with clinical faculty/preceptor and personal experience had the strongest impact on overall satisfaction for both. Procedural fellows reported lower satisfaction with physical environment.

CONCLUSIONS

Internal medicine fellows are highly satisfied with their VA training. Nonprocedural fellows reported higher satisfaction with most items. For both procedural and non-procedural fellows, clinical faculty/preceptor and personal experience have the strongest impact on overall satisfaction.

The Impact of VA's geriatric research, education and clinical centers on academic affiliates

The education mission of the Department of Veterans Affairs (VA) is to train health professionals to benefit VA and the United States. One approach for achieving that mission, along with VA's research and clinical missions, was the establishment of Geriatric Research, Education and Clinical Centers (GRECCs) in 1975. These were developed at VA hospital sites that had existing strong partnerships with schools of medicine already engaged in research on aging. GRECCs were funded to enhance those research enterprises, to expand health professions education in geriatrics, to expand interest in geriatrics among medical faculty and to support them to become more expert in geriatrics, to develop new approaches to care of the aging, and to disseminate the lessons learned within VA and beyond. Using 2001 and 2008 data from two surveys of U.S. medical schools' geriatrics programs, this article explores the impact of GRECCs on geriatric programs at their affiliated schools of medicine. It demonstrates how VA's academic mission through GRECCs has benefited VA and its affiliates and how it has benefited the nation through the growth of geriatric medicine as an academic enterprise and a legitimate clinical specialty.

Measuring progressive independence with the resident supervision index: theoretical approach

BACKGROUND

Graduate medical education is based on an on-the-job training model in which residents provide clinical care under supervision. The traditional method is to offer residents graduated levels of responsibility that will prepare them for independent practice. However, if progressive independence from supervision exceeds residents' progressive professional development, patient outcomes may be at risk. Leaders in graduate medical education have called for "optimal" supervision, yet few studies have conceptually defined what optimal supervision means and whether optimal care is theoretically compatible with progressive independence, nor have they developed a test for progressive independence.

OBJECTIVE

This research develops theory and analytic models as part of the Resident Supervision Index to quantify the intensity of supervision.

METHODS

We introduce an explicit set of assumptions for an ideal patient-centered theory of optimal supervision of resident-provided care. A critical assumption is that informed attending staff will use available resources to optimize patient outcomes first and foremost, with residents gaining clinical competencies by contributing to optimal care. Next, we derive mathematically the consequences of these assumptions as theoretical results.

RESULTS

Under optimal supervision, (1) patient outcome is expected to be no worse than if residents were not involved, (2) supervisors will avoid undersupervising residents (when patients are at increased risk for poor outcomes) or oversupervising residents (when residents miss clinical opportunities to practice care), (3) optimal patient outcomes will be compatible with progressive independence, (4) progressive development can be inferred from progressive independence whenever residents contribute to patient care, and (5) analytic models that test for progressive independence will emphasize adjusting the association between length of graduate medical education training and supervision for case complexity and clinic workload, but not patient health outcomes.

CONCLUSION

An explicit theoretical framework is critical to measure scientifically progressive independence from supervision using graduate medical education data.

Measuring progressive independence with the resident supervision index: empirical approach

BACKGROUND

A Resident Supervision Index (RSI) developed by our research team quantifies the intensity of resident supervision in graduate medical education, with the goal of testing for progressive independence. The 4-part RSI method includes a survey instrument for staff and residents (RSI Inventory), a strategy to score survey responses, a theoretical framework (patient centered optimal supervision), and a statistical model that accounts for the presence or absence of supervision and the intensity of patient care.

METHODS

The RSI Inventory data came from 140 outpatient encounters involving 57 residents and 37 attending physicians during a 3-month period at a Department of Veterans Affairs outpatient clinic. Responses are scored to quantitatively measure the intensity of resident supervision across 10 levels of patient services (staff is absent, is present, participated, or provided care with or without a resident), case discussion (resident-staff interaction), and oversight (staff reviewed case, reviewed medical chart, consulted with staff, or assessed patient). Scores are analyzed by level and for patient care using a 2-part model (supervision initiated [yes or no] versus intensity once supervision was initiated).

RESULTS

All resident encounters had patient care supervision, resident oversight, or both. Consistent with the progressive independence hypothesis, residents were 1.72 (P  =  .019) times more likely to be fully responsible for patient care with each additional postgraduate year. Decreasing case complexity, increasing clinic workload, and advanced nonmedical degrees among attending staff were negatively associated with supervision intensity, although associations varied by supervision level.

CONCLUSIONS

These data are consistent with the progressive independence hypothesis in graduate medical education and offer empirical support for the 4-part RSI method to quantify the intensity of resident supervision for research, program evaluation, and resident assessment purposes. Before informing policy, however, more scientific research in actual teaching settings is needed to better understand the relationships among patient outcomes, clinic workload, case complexity, and graduate medical education experience in resident supervision and professional development.

The Department of Veterans Affairs National Quality Scholars Fellowship Program: experience from 10 years of training quality scholars

The Department of Veterans Affairs (VA) National Quality Scholars Fellowship Program (VAQS) was established in 1998 as a postgraduate medical education fellowship to train physicians in new methods of improving the quality and safety of health care for veterans and the nation. The VAQS curriculum is based on adult learning theory, with a national core curriculum of face-to-face components, technologically mediated distance learning components, and a unique local curriculum that draws from the strengths of regional resources. VAQS has established strong ties with other VA programs. Fellows' research and quality improvement projects are integrated with local and regional VA leaders' priorities, enhancing the relevance and visibility of the fellows' efforts and promoting recruitment of fellows to VA positions. VAQS has enrolled 98 fellows since 1999; 75 have completed the program and 24 are currently enrolled. Fellowship graduates have pursued a variety of career paths: 17% are continuing training (most in VA), 31% hold a VA faculty/staff position, 66% are academic faculty, and 80% conduct clinical or research work related to health care improvement. Graduates have held leadership positions in VA, Department of Defense, academic medicine, and public health agencies. Combining knowledge about the improvement of health care with adult learning strategies, distance learning technologies, face-to-face meetings, local mentorship, and experiential projects has been successful in improving care in VA and preparing physicians to participate in, study, and lead the improvement of health care quality and safety.

Teaching systems-based practice to primary care physicians to foster routine implementation of evidence-based depression care

Although health care organizations seeking to improve quality often must change the system for delivering care, there is little available evidence on how to educate staff and providers about this change. As part of a 2002-2003 Veterans Health Administration multisite project using collaborative care to improve the management of depression, the authors implemented the Translating Initiatives for Depression into Effective Solutions (TIDES) program. Five steps were followed for teaching systems-based practice: (1) determine providers' educational needs (through administrative data, expert opinion, and provider discussion), (2) develop educational materials (based on needs assessed), (3) help each of seven sites develop an educational intervention, (4) implement the intervention, and (5) monitor the intervention's effectiveness. Sites relied primarily on passive educational strategies. There was variable implementation of the different components (e.g., lecture, educational outreach). No site chose to write up its education plan, as was suggested. The authors thus suggest that the educational model was successful at identifying providers' needs and creating appropriate materials, because the program was not advertised in other ways and because almost all providers referred patients to the program. However, the educational model was only partially successful at getting sites to develop and implement an educational plan, although provider behavior did change. Overall, the program was somewhat effective at teaching systems-based practice. The authors believe the best way to enhance effectiveness is to build education into the system rather than rely on a separate system for education.

The need for specialty curricula based on core competencies: a white paper of the Conjoint Committee on Continuing Medical Education

At present there is no curriculum to guide physician lifelong learning in a prescribed, deliberate manner. The Conjoint Committee on Continuing Medical Education, a group representing 16 major stakeholder organizations in continuing medical education, recommends that each specialty society and corresponding board reach consensus on the competencies expected of physicians in that specialty. Experts in a specialty will define content-based core competencies in the areas of patient care, medical knowledge, practice-based learning and improvement, interpersonal and communication skills, professionalism, and systems-based practice. These competencies, when cross-referenced with expertise, comprise a framework for specialty curricula and board maintenance of certification programs. The American Academy of Ophthalmology and the American Board of Ophthalmology already have implemented this recommendation. Their work is reported as a model for further development. A competency-based curriculum framework offers a foundation for continuing medical education in diverse practice settings and provider organizations.

Using Baldrige criteria to meet or exceed Accreditation Council for Continuing Medical Education Standards

Continuing medical education providers accredited by the Accreditation Council for Continuing Medical Education (ACCME) may apply organizational assessment strategies beyond the ACCME Essential Areas, Elements, and Criteria. The Malcolm Baldrige National Quality Program offers an organizational assessment strategy commonly used in business, health care, and education settings. An analysis of both standards pointed out useful associations between the ACCME Essential Areas and the Baldrige National Quality Program Education Criteria (2003). Including leadership, governance, and social responsibility, the Baldrige Education Criteria provide a more comprehensive organizational assessment and stronger emphasis on a wider variety of results. The present analysis suggests that a continuing medical education provider could meet, and possibly exceed, the ACCME standards by applying the Baldrige Education Criteria in a "self-study" process to define, measure, monitor, and document fundamental organizational responsibilities and performance.

Domains-based outcomes assessment of continuing medical education: the VA's model

Demonstrating outcomes of continuing medical education (CME) efforts has become increasingly important to CME providers, accrediting organizations, and licensing bodies. Many CME providers have difficulty defining the nature of the outcomes, much less documenting the outcomes for which they are responsible. The vague nature of the terms "outcome," "impact," or "result" in the complexity of health care and medical education environments is a particular obstacle to many education providers. To overcome these barriers, the VA's Employee Education System (EES), a large CME provider, created a model identifying five major domains of possible outcomes for CME interventions; these are the domains of individual participants, employee teams, the larger organization, patients, and the community. These domains are useful in either assessing a single CME activity's outcomes or comprehensively assessing a CME provider's outcomes-assessment strategy. The use of such a domains-based outcomes-management strategy links organizational mission, needs assessment, specific activity assessment, and assessment of the overall education program. This approach may be useful to CME providers, accrediting and licensing bodies, or others interested in the relationship of CME outcomes to the activities of CME providers.

Media richness and social information processing: rationale for multifocal continuing medical education activities

Academic business communication has studied the results of media selection in organizations. Little of this work has been discussed in the context of continuing medical education (CME); however, it may apply to improving the design of educational activities. This article reviews literature on media richness and social information processing theories. The concept of media richness suggests that media choice results from a match between the objective characteristics of the medium and the content requirements of a message. In this context, media include face-to-face conversation and print and electronic media. Social information processing theory suggests that media selection is also based on participants' social norms for how information is communicated in their environment and the participants' familiarity with specific media types. Appraisal of CME with respect to these theories suggests that the complex relationship of CME content and CME participant environments invites the most effective strategies of multiple media experienced over time in what might be called multifocal continuing medical education.

Cutaneous injection of human subjects with macrophage inflammatory protein-1 alpha induces significant recruitment of neutrophils and monocytes

Macrophage inflammatory protein (MIP-1 alpha), a member of the CC chemokine subfamily, has been shown to attract T cells and monocytes in vitro and to be expressed at sites of inflammation. Although the in vitro activities of MIP-1 alpha have been well documented, the in vivo biological activities of MIP-1 alpha in humans have not been studied. To address this, we challenged human subjects by intradermal injection with up to 1000 pmol of MIP-1 alpha and performed biopsies 2, 10, and 24 h later. Although no acute cutaneous or systemic reactions were noted, endothelial cell activation, as indicated by the expression of E-selectin, was observed. In agreement with its in vitro activity, monocyte, lymphocyte, and, to a lesser degree, eosinophil infiltration was observed, peaking at 10-24 h. Surprisingly, in contrast to its reported lack of in vitro neutrophil-stimulating activity, a rapid infiltration of neutrophils was observed in vivo. This neutrophil infiltration occurred as early as 2 h, preceding the appearance of other cells, and peaked at 10 h. Interestingly, we found that neutrophils in whole blood, but not after isolation, expressed CCR1 on their cell surface. This CCR1 was thought to be functional as assessed by neutrophil CD11b up-regulation following whole-blood MIP-1 alpha stimulation. These studies substantiate the biological effects of MIP-1 alpha on monocytes and lymphocytes and uncover the previously unrecognized activity of MIP-1 alpha to induce neutrophil infiltration and endothelial cell activation, underscoring the need to evaluate chemokines in vivo in humans.

Antagonizing leukotriene B4 receptors delays cardiac allograft rejection in mice

BACKGROUND

Allograft rejection is a cellular immunological/inflammatory response that is, in part, directed by potent proinflammatory mediators. This study was designed to test the hypothesis that leukotriene B4 (LTB4) may have a role in graft rejection and that LTB4 receptor antagonists may be clinically useful in the treatment of allograft rejection.

METHODS

We evaluated the potent and selective LTB4 receptor antagonist CP-105696 in a murine heterotopic cardiac allograft model with oral dosing daily for 28 days or in an induction protocol (day -1 to day 3).

RESULTS

At a dose of 50 mg/kg/day (28 days), B10.BR (H2k) allografts transplanted into C57Bl/6 (H2b) recipients were significantly protected, as reflected by the mean survival time versus control grafts (27+/-20 days [n=10] vs. 12+/-6 days [n=14]; P=0.0146). Using an induction protocol (day -1 to day 3), CP-105696 at 100 mg/kg/day significantly prolonged allograft survival (33+/-23 days [n=9]; P=0.0026), but CP-105696 at 10 mg/kg/day did not (18+/-16 days [n=8]; P=0.1433). Syngeneic grafts survived indefinitely (n=11). Immunohistological evaluation of allografts at rejection revealed a mononuclear cell infiltrate composed primarily of CD3+ and CD11b+ (Mac-1+) cells, which were infrequent in syngeneic grafts. Allografts from mice treated with CP-105696 at 50 or 100 mg/kg/day demonstrated a selective reduction in beta2-integrin (Mac-1) expression on monocytes/macrophages, as demonstrated by CD11b staining density compared with allograft controls.

CONCLUSIONS

The results suggest that LTB4 or other potential ligands for LTB4 receptors may be important mediators of allograft rejection and support the clinical evaluation of LTB4 receptor antagonists in human organ transplantation.

Diffusion of laparoscopic cholecystectomy in the Veterans Affairs health care system, 1991-1995

CONTEXT

Laparoscopic cholecystectomy has become the most widely used treatment for gallbladder disease. In HMO, Medicare, and fee-for-service settings, cholecystectomy rates increased 28% to 59% after introduction of laparoscopic cholecystectomy.

OBJECTIVE

To investigate the impact of the introduction of laparoscopic cholecystectomy on cholecystectomy rates and the operative mortality rate in Veterans Affairs (VA) hospitals.

DESIGN

Sequential cross-sectional study.

PATIENTS

All patients who underwent cholecystectomy from 1991 (before introduction of laparoscopic cholecystectomy) to 1995.

SETTING

133 VA hospitals.

OUTCOME MEASURES

Cholecystectomy rates, use of laparoscopic or open cholecystectomy, and operative mortality rate.

RESULTS

The annual number of cholecystectomies in the VA system increased by 10% from 1991 to 1995; the laparoscopic procedure accounted for 25% of the caseload in 1992 and 52% in 1995. Compared with patients having laparoscopic cholecystectomy, those having open cholecystectomy were more likely to be older, be male, and have acute cholecystitis or comorbid illnesses (P < 0.001). The operative mortality rate of open cholecystectomy increased by 46% during this 4-year period (from 2.4% to 3.4%) and was constant for laparoscopic cholecystectomy (about 0.5%). Given the increasing use of the laparoscopic procedure, however, the overall mortality rate of cholecystectomy during surgery decreased by 22% (from 2.4% to 1.8%). Despite increased use of the surgery, the absolute number of deaths decreased by 9%.

CONCLUSIONS

The introduction of laparoscopic cholecystectomy in the VA system was not accompanied by a large increase in cholecystectomy rates, as it was in fee-for-service, Medicare, and HMO systems. Because the rate of operations has changed only slightly, the total number of cholecystectomy-related deaths has decreased.

Predictors of resource utilization for hospitalized patients with Pneumocystis carinii pneumonia (PCP): a summary of effects from the multi-city study of quality of PCP care

To determine whether patient and hospital characteristics were significantly associated with variations in Pneumocystis carinii (PCP) care and outcomes, we analyzed the use of diagnostic tests, intensive care units (ICUs), anti-PCP medications for persons hospitalized with human immunodeficiency virus (HIV)-related PCP, and hospital discharge status. We conducted retrospective chart reviews of a cohort of 2,174 patients with PCP hospitalized in 1987-1990. Outcomes included process of care for PCP and in-hospital mortality rates. Persons with PCP who were more severely ill at admission were more likely to have early medical care, to receive care in an intensive care unit, and to die in hospital. After we adjusted for differences in this severity of illness, we noted that Medicaid patients, injection drug users (IDUs), and patients treated at VA or county hospitals were significantly less likely than others to have diagnostic bronchoscopies and that persons covered by Medicaid, with a previous diagnosis of acquired immunodeficiency syndrome (AIDS), who did not receive prior zidovudine (AZT) or who received care in a VA hospital had the highest chances of in-hospital death. Insurance and risk group characteristics, severity of illness, and hospital characteristics appear to be the most important determinants of the intensity and timing of medical care and outcomes among patients hospitalized with PCP.

Tool use and team success in continuous quality improvement: are all tools created equal?

This article describes a study that used data from the Department of Veterans Affairs Health Services' Western Region TQI Registry to compare the relationship between theory tools, data tools, and perceived quality improvement. No significant bivariate relationship between the use of theory tools and perceived improvement was found, but there was a positive and significant relationship between the use of data tools and perceived improvement. The use of data management tools by all teams in the study was much lower than expected.

Relationship between procedures and health insurance for critically ill patients with Pneumocystis carinii pneumonia

The objective of the present study was to assess the association between type of health insurance coverage and use of diagnostic tests and therapies among patients with AIDS-related Pneumocystis carinii pneumonia (PCP). Fifty-six private, public, and community hospitals in Chicago, Los Angeles, and Miami were selected for the study, and the charts of 890 patients with empirically treated or cytologically confirmed PCP, hospitalized during 1987 to 1990 were retrospectively reviewed. Patients were classified by insurance status: self-pay (n = 56), Medicaid (n = 254), or private insurance, including health maintenance organizations and Medicare (n = 580). Primary outcomes were the use and timing of bronchoscopy, the type and timing of PCP therapy, and in-hospital mortality. The results indicate that Medicaid patients were less likely than privately insured patients to undergo bronchoscopy (relative odds = 0.61; 95% CI = 0.40, 0.93; p = 0.02) or to have their diagnosis of PCP confirmed (relative odds = 0.51; 95% CI = 0.33, 0.77), after adjusting for patient, severity of illness, and hospital characteristics. Medicaid patients were approximately three-fourths more likely than privately insured patients (relative odds = 1.73; 95% CI = 1.01, 2.96; p = 0.04) to die in-hospital, after adjusting for patient, severity of illness, and hospital characteristics. However, with further adjustment for confirmation of PCP, Medicaid patients no longer had a significantly higher likelihood of dying in-hospital. We conclude that Medicaid patients are less likely to receive diagnostic bronchoscopy than privately insured or self-insured patients, more likely to be empirically treated for PCP, and more likely to die in-hospital.(ABSTRACT TRUNCATED AT 250 WORDS)

Empirically treated Pneumocystis carinii pneumonia in Los Angeles, Chicago, and Miami: 1987-1990

Many patients infected with the human immunodeficiency virus (HIV) with symptoms suggestive of pneumonia are treated empirically for Pneumocystis carinii pneumonia (PCP), although other bacterial infections (e.g., tuberculosis) and pulmonary Kaposi's sarcoma may cause identical symptoms. Empiric treatment for PCP may result in misdiagnosis and mistreatment. When the outcomes of cytologically confirmed versus empirically treated PCP cases were evaluated, the most important predictors of in-hospital mortality were severity of illness and use of bronchoscopy. Persons who did not undergo bronchoscopy had higher mortality rates than patients negative by bronchoscopy or cytologically confirmed as positive for PCP (22% vs. 11% vs. 14%, P < .01), although severity of illness and timing of anti-PCP medications did not differ significantly. Compared with cytologically confirmed cases, persons who did not have bronchoscopy were more likely to die than were bronchoscopy-negative patients (P < .05), after adjusting for severity of illness. Bronchoscopy use may have contributed to better outcomes for persons treated for HIV-related PCP.

The learning curve for AIDS-related Pneumocystis carinii pneumonia: experience from 3,981 cases in Veterans Affairs Hospitals 1987-1991

Previous studies have found lower mortality rates for AIDS-related Pneumocystis carinii pneumonia (PCP) in hospitals with higher levels of experience with PCP. It is not known if patients are selectively referred to better hospitals or if there is a learning curve whereby outcomes improve as physicians gain experience in treating PCP. We assessed cases of PCP at 140 Veterans Administration (VA) Medical Centers in the United States. During 1987-1991, 3,981 patients were hospitalized with first-episode AIDS-related PCP. Mortality at 30 days after admission. For these 3,981 hospitalizations at the 140 study hospitals, the 30-day mortality was 19%. Logistic regression models indicate that older age, race, geographic area, earlier year of treatment, hospitalization in the previous 12 months, and lower levels of hospital experience with AIDS were significant predictors of mortality at 30 days after admission. Compared with hospitals that had treated three cases or fewer of first-episode PCP, the odds of mortality at 30 days at hospitals that treated > 50 cases of first-episode PCP were 0.73 (95% confidence interval 0.58-0.91), after controlling for differences in characteristics of the patients, year, and region. Mortality of patients with AIDS-related PCP decreases as VA hospitals gain experience. Longitudinal analyses over a 5-year period suggest that a learning curve best explains this finding.

A rapid preadmission method for predicting inpatient course of disease for patients with HIV-related Pneumocystis carinii pneumonia

Pneumocystis carinii pneumonia (PCP) has been the most common reason for hospitalization and the most common cause of death for persons with HIV infection. Hospital mortality rates for PCP range from 10 to 60%. Studies that evaluate differences in hospital mortality rates must control for differences in patient severity of illness. We developed a simple staging system for categorizing severity of illness in patients with PCP. We analyzed the relation between clinical factors and in-hospital mortality for 576 hospitalized patients with HIV-related PCP treated at 56 hospitals for the years 1987 to 1990. Four stages of PCP could be identified based on three routinely measured clinical variables: alveolar-arterial oxygen difference, total lymphocyte count, and body mass index. The mortality rate increased by stage: 1% for Stage 1, 8% for Stage 2, 23% for Stage 3, and 48% for Stage 4. The four-stage severity system compared well with previous models developed for AIDS and for PCP, and is easier to use in clinical practice. Our staging system identifies patients with a high and low risk of in-hospital death upon admission. Physicians may benefit from consideration of PCP stage in deciding on management strategies. In addition, researchers involved in clinical trials of new agents for PCP might consider stratification by PCP stage in order to define homogenous groups.

Free radicals enhance basal release of D-[3H]aspartate from cerebral cortical synaptosomes

Excessive generation of free radicals has been implicated in several pathological conditions. We demonstrated previously that peroxide-generated free radicals decrease calcium-dependent high K(+)-evoked L[3H]-glutamate release from synaptosomes while increasing calcium-independent basal release. The present study evaluates the nonvesicular release of excitatory amino acid neurotransmitters, using D-[3H]aspartate as an exogenous label of the cytoplasmic pool of L-glutamate and L-aspartate. Isolated presynaptic nerve terminals from the guinea pig cerebral cortex were used to examine the actions and interactions of peroxide, iron, and desferrioxamine. Pretreatment with peroxide, iron alone, or peroxide with iron significantly increased the calcium-independent basal release of D-[3H]aspartate. Pretreatment with desferrioxamine had little effect on its own but significantly limited the enhancement by peroxide. High K(+)-evoked release in the presence of Ca2+ was enhanced by peroxide but not by iron. These data suggest that peroxide increases nonvesicular basal release of excitatory amino acids through Fenton-generated hydroxyl radicals. This release could cause accumulation of extracellular excitatory amino acids and contribute to the excitotoxicity associated with some pathologies.

Modification of monoclonal antibody carbohydrates by oxidation, conjugation, or deoxymannojirimycin does not interfere with antibody effector functions

Site-specific attachment of metal chelators or cytotoxic agents to the carbohydrate region of monoclonal antibodies results in clinically useful immunoconjugates [Doerr et al. (1991) Ann Surg 214: 118, Wynant et al. (1991) Prostate 18: 229]. Since the capacity of monoclonal antibodies (mAb) to mediate tumor cell lysis via antibody-dependent cellular cytotoxicity (ADCC) or complement-dependent cytotoxicity (CDC) may accentuate the therapeutic effectiveness of immunoconjugates, we determined whether site-specific modification of mAb carbohydrates interfered with these functions. The chemical modifications examined consisted of periodate oxidation and subsequent conjugation to either a peptide linker/chelator (GYK-DTPA) or a cytotoxic drug (doxorubicin adipic dihydrazide). mAb-associated carbohydrates were also modified metabolically by incubating hybridoma cells in the presence of a glucosidase inhibitor deoxymannojirimycin to produce high-mannose antibody. All four forms (unaltered, oxidized, conjugated and high-mannose) of murine mAb OVB-3 mediated tumor cell lysis via CDC. Similarly, equivalent ADCC was observed with native and conjugated forms of mAb OVB-3 and EGFR.1. ADCC was achieved with different murine effector cells such as naive (NS), poly (I*C)- and lipopolysaccharide-stimulated (SS) spleen cells, or Corynebacterium-parvum-elicited peritoneal cells (PEC). All murine effector cell types mediated tumor cell lysis but differed in potency such that PEC > SS > NS. Excellent ADCC activity was also demonstrable by human peripheral blood mononuclear cells with OVB-3-GYK-DTPA and high-mannose OVB-3 mAb. ADCC activity was detectable in vivo: both native and conjugated OVB-3 inhibited growth of OVCAR-3 xenografts in nude mice primed with C. parvum. In conclusion, modification of mAb carbohydrates did not compromise their in vivo or in vitro biological functions. Therefore, combination therapy using immunomodulators to enhance the effector functions of site-specific immunoconjugates could be seriously contemplated.

Improved outcomes in intensive care units for AIDS-related Pneumocystis carinii pneumonia: 1987-1991

Respiratory failure due to Pneumocystis carinii pneumonia (PCP) is the most common complication requiring an intensive care unit (ICU) for persons with AIDS. In this study, we evaluated patterns of ICU use for ICU patients with first-episode PCP in 15 Veterans Administration Medical Centers from 1987 to 1991. Twelve percent of all patients with PCP received care in the ICU. The survival rates improved steadily during these years. Although there was little variation in the relative frequency of ICU use, the effectiveness of ICU use appeared to improve over time. In the more recent years, relatively more survivors and relatively fewer nonsurvivors received care in an ICU. Changes in medical practice such as adjunctive use of steroids for severe cases of PCP and more effective use of scarce resources may account for the improved survival rates for patients with PCP who are treated in an ICU.

Effect of oxidative stress on excitatory amino acid release by cerebral cortical synaptosomes

Previous studies in our laboratory have suggested that an oxidation reaction is responsible for the actions of free radicals to decrease synaptic potentials. Recently we observed that free radicals both decreased depolarization-induced vesicular release and enhanced basal, nonvesicular release of the excitatory amino acid, [3H]L-glutamate. In order to evaluate the contribution of oxidative reactions to this latter effect, we evaluated the actions of the oxidizing agent chloramine-T on synaptosomal release of excitatory amino acids, using [3H]D-aspartate as the exogenous label. Basal and depolarization evoked [3H]D-aspartate release were calcium-independent and nonvesicular. Chloramine-T pretreatment significantly increased basal release, while having no effect on high K(+)-evoked release. These data suggest that an oxidative process can mimic the free radical increase of basal release, as well as the decrease in synaptic potentials. On the other hand, the calcium-independent-evoked release may involve a different mechanism. Our results demonstrate that under basal, nondepolarizing conditions, oxidative stress exerts an adverse effect on the presynaptic nerve terminal, resulting in an increased release of potentially damaging excitatory amino acid neurotransmitters.

Use of traditional and modern health services by Laotian refugees

Although refugee health care emerged as a special interest in the United States following the influx of almost a million Southeast Asians since 1975, few studies have been done of the influence of refugee traditions on the use of Western medical services. The illness patterns, medical beliefs, and health care behavior of a Southeast Asian refugee group, the Mien from Laos are described in this study. A cohort of 119 Mien refugees living in Richmond, California, was observed for a 6-month period. In-home interviews were undertaken about all episodes of ill health, including treatment and health care decisions. This study shows that the Mien integrate traditional healing beliefs and practices with the use of American health services. Such findings are important because the increasing cultural diversity in the United States, particularly in Western states, necessitates that health care professionals understand the importance of cultural factors for access to and the use of health care by all patients including refugees and other immigrant groups.

Peroxide effects on [3H]l-glutamate release by synaptosomes isolated from the cerebral cortex

Basal (non-depolarized) and high K(+)-stimulated [3H]L-glutamate release in the presence and absence of Ca2+ were assessed using presynaptic nerve terminals (synaptosomes) isolated from the cerebral cortex of the guinea pig. Basal glutamate release was found to be Ca(2+)-independent and was significantly increased following treatment with hydrogen peroxide (H2O2). On the other hand, depolarization-induced release had both a Ca(2+)-dependent and Ca(2+)-independent component. Both components of stimulated release were suppressed by H2O2. In fact, Ca(2+)-dependent evoked release was virtually eliminated by H2O2 pretreatment. The data suggest that H2O2 exerts a differential effect on the neurochemical mechanisms involved in basal and stimulated glutamate release at the presynaptic nerve terminal.

Interaction studies of tilomisole, aspirin, and naproxen in acute and chronic inflammation with assessment of gastrointestinal irritancy in the rat

The effect of combination NSAID therapy of tilomisole with aspirin or naproxen was studied in rats with carrageenan-induced paw edema and established adjuvant arthritis. Inflamed paws were measured using mercury plethysmography and the arthritic paws were X-rayed to determine any bony/soft tissue changes. The gastrointestinal tract was also examined for bleeding and ulceration. Tilomisole had a less potent acute anti-inflammatory effect than aspirin or naproxen, but produced no significant gastrointestinal damage. A significant reduction in anti-inflammatory activity was observed with the tilomisole/aspirin combination in acute inflammation. Only additive interactions were observed with the naproxen inhibition. In the established arthritis assay, a significant synergistic anti-inflammatory response, i.e. both inhibition of paw edema and bone erosion, was also observed with the 80 and 93% tilomisole/naproxen combinations. The gastric ulcerogenic effect of the combination paralleled its increased activity. The synergism between tilomisole and naproxen in this chronic arthritic model may be due to enhanced cyclooxygenase inhibitory activity. These drug interaction studies suggest possible interactions in human clinical trials of rheumatoid arthritis.

Frequent anti-V-region immune response to mouse B72.3 monoclonal antibody

The immune response of 56 colorectal cancer patients to a single infusion of 1 mg of radiolabeled (111In) mouse B72.3-GYK-DTPA immunoconjugate was examined using a double-antigen radiometric assay system. The incidence of antibody response was 48% to polyclonal mouse IgG, 71% to mouse B72.3, and 62% to chimeric B72.3. Twelve patients (23%) had an antibody response to B72.3 V region in the absence of binding to polyclonal mouse IgG. An antiidiotype response was demonstrated in sera from 36% of 25 patients examined and correlated well with chimeric B72.3-GYK-DTPA immunoconjugate binding (r = 0.72, moderately well with mouse B72.3 binding (r = 0.56), and not at all with polyclonal mouse IgG binding (r = 0.28). The peak antibody response occurred most frequently 2 weeks postinfusion, although a "delayed" peak response to chimeric B72.2 occurred in 29% of patients. This study suggests that mouse B72.3 causes an immune response in the majority of patients and that antibody response to the V region is common. Understanding the physiological significance of these antibody responses will require correlation with the kinetics and tumor localization of repeat infusions of such immunoconjugates.

Immunohistochemical and pharmacokinetic characterization of site-specific immunoconjugate 15A8-glycyl-tyrosyl-(N-epsilon-diethylenetriamine pentaacetic acid)-lysine derived from anti-breast carcinoma monoclonal antibody 15A8

In this study, the breast carcinoma-reactive monoclonal antibody 15A8 and a site-specific immunoconjugate of the antibody, 15A8-glycyl-tyrosyl-(N-epsilon-diethylenetriamine pentaacetic acid)-lysine (15A8-GYK-DTPA), were characterized by immunohistological methods for reactivity with normal and neoplastic human tissues and normal cynomolgus monkey tissues. In addition, 15A8-GYK-DTPA labeled with 111In was assessed by in vivo imaging and pharmacokinetic studies for localization to human tumor xenografts in nude mice. The native antibody and the site-specific immunoconjugate exhibited similar limited reactivity with normal human tissues. Specifically, epithelial structures, including normal breast epithelium, lung alveoli, bronchial epithelium and glands, liver bile ducts, pancreatic ducts, kidney distal and collecting tubules, epidermal and esophageal epithelium, endometrial glands, and thymic Hassall's corpuscles, were reactive. Normal monkey tissues stained with 15A8 exhibited a similar pattern of reactivities. Antibody 15A8 reacted broadly with epithelium-derived tumors; more than 60% of the cells in all of the breast, colon, non-small cell lung, ovarian, prostate, bladder, and renal carcinomas tested expressed the antigen. In contrast, a variety of nonepithelial neoplasms, including lymphomas, melanomas, sarcomas, and small cell lung carcinomas, were nonreactive. 15A8-GYK-DTPA-111In administered i.v. rapidly localized to and imaged both MX-1 and MCF-7 human breast carcinoma xenografts in nude mice, reaching maximal levels of about 20% of injected dose/g of tumor within 4 days. No unusual localization to any nontumor tissue or organ was seen; the level of radioactivity in the normal tissues and organs was at or below that seen in the blood. Furthermore, the immunoconjugate did not accumulate in xenografts of the antigen-negative breast carcinoma ZR-75-1, which indicates that tumor localization was antigen specific. Pharmacokinetic studies in cynomolgus monkeys suggested that significant amounts of 15A8-GYK-DTPA-111In did not localize to normal epithelia and demonstrated that the immunoconjugate was not toxic. These findings suggest that antibody 15A8 may be useful in the diagnosis and therapy of breast cancer and possibly other carcinomas.

Antitumor monoclonal antibodies generated by immunization with mucins

This report describes the development and characterization of monoclonal antibody EG2.3. Although produced from a fusion that used splenocytes from donor mice immune to bovine salivary mucin (BSM), EG2.3 bound selectively to a number of human tumor cell lines including colon adenocarcinoma LS174T. Therefore, EG2.3 was compared to B72.3, another mucin (TAG-72) binding monoclonal antibody that also binds to LS174T. Like B72.3, EG2.3 reacted with an epitope on TAG-72. However, these two MAbs differed in a number of ways. Treatment of mucin or TAG-72 with periodate did not reduce the binding of EG2.3 to either antigen. In contrast, B72.3 did not react with either periodate treated antigens. Removal of sialic acid from either BSM or TAG-72 compromised the reactivity of both EG2.3 and B72.3. It was concluded that the EG2.3 binding site was distinct from the carbohydrate structure detected by B72.3.

Interaction of Ca-channel blockers and high pressure at the crustacean neuromuscular junction

Exposure to high pressure causes a significant depression of synaptic transmission. We examined the effects of various Ca-channel blockers and their interaction with high pressure on excitatory neuromuscular junction currents (EJCs) of lobster abdominal muscles. Reduced [Ca2+]o to half of normal concentration or exposure to 40-60 microM CdCl2, 10-20 microM NiCl2 and 1 microM omega-conotoxin decreased EJCs by 50%. Nifedipine, Nitrendipine and Bay K-8644 were ineffective. Either Ca-blockers or reduced [Ca2+]o, enhanced EJC suppression exerted by high pressure. The data suggest that high pressure primarily affects Ca2+ inflow at the presynaptic terminals through N-type voltage-gated Ca-channel.

A 23187-stimulated calcium uptake and GABA release by cerebrocortical synaptosomes: effects of high pressure

Guinea pig cerebrocortical synaptosome preparations were used to study the effect of compression to 62 ATA on 45Ca2+ uptake and [3H]GABA release using a calcium ionophore A 23187, which bypasses the voltage-sensitive calcium channel. Pressure was found to exert a suppressive effect on the A 23187-induced release of [3H]GABA, while having no significant effect on A 23187-stimulated 45Ca2+ uptake. On the other hand, both depolarization-induced 45Ca2+ uptake and [3H]GABA release were inhibited by pressure exposure. These results suggest that pressure may suppress GABA release by affecting pre-synaptic events subsequent to calcium influx.

Immunohistochemical and pharmacokinetic characterization of the site-specific immunoconjugate CYT-356 derived from antiprostate monoclonal antibody 7E11-C5

In this study, a site-specific immunoconjugate, designated CYT-356, of the prostate-reactive monoclonal antibody 7E11-C5 was characterized by immunohistological methods for reactivity with normal and neoplastic human tissues. In addition, CYT-356 labeled with 111In was assessed by in vivo imaging and pharmacokinetic studies for localization to human tumor xenografts in nude mice. The native antibody and the site-specific immunoconjugate exhibited similar patterns of reactivity with normal human tissues. Although the majority of tissues tested were negative, weak reactivity with cardiac muscle, proximal kidney tubules, and sweat glands was observed. Positive staining of normal prostate epithelial cells and glandular lumina and strong reactivity with a subset of skeletal muscle cells were also observed. CYT-356 reacted with 100% of prostate tumors examined but was negative on a variety of other neoplasms. Following i.v. administration, CYT-356-111In rapidly localized to and imaged LNCaP human prostate adenocarcinoma xenografts in nude mice, reaching maximal levels of about 30% of injected dose/g of tumor within 3 days. No unusual localization was seen to any nontumor tissue or organ; the level of radioactivity in the normal tissues and organs was at or below that seen in the blood. The localization to xenografts was antigen specific and the accessible binding sites in 100-200-mg tumors appeared to be saturated at an antibody dose between 10 and 100 micrograms. These findings suggest that the CYT-356 immunoconjugate may be useful in the diagnosis and therapy of prostate cancer.

Characterization of interleukin 1 induced rabbit chondrocyte phospholipase A2

Stimulation of rabbit articular chondrocytes with interleukin 1 (IL-1) results in the activation of intracellular phospholipase A2 (PLA2) and the subsequent secretion of this enzyme into the extracellular milieu. Pretreatment of chondrocytes with actinomycin D or cycloheximide significantly inhibited IL-1 induced PLA2 activation and secretion, suggesting that the enzyme induction process is RNA and protein synthesis dependent. Chondrocyte PLA2 is highly calcium dependent with a 1 mM optimum CA++ concentration for hydrolytic activity; little or no hydrolysis is observed in the absence of calcium and the hydrolytic activity is abolished in the presence of 10 mM ethylenediamine tetraacetic acid. The enzyme is also pH sensitive with optimal PLA2 hydrolytic activity observed at pH 6.5-7. Further, chondrocyte PLA2 was sensitive to inhibition by mepacrine, a compound with PLA2 inhibitory activity. The IL-1 induced chondrocyte PLA2 has a molecular weight of approximately 10 kDa, as determined by molecular sieve G75 column chromatography. The apparent molecular weight and CA++, pH and drug sensitivity of the extracellular and intracellular forms of the IL-1 induced chondrocyte PLA2 are indistinguishable. Since this IL-1 induced enzyme has similar biochemical characteristics to PLA2 enzymes isolated from human rheumatoid and osteoarthritic synovial fluid, we suggest that the chondrocyte may be an important cellular source for this PLA2 enzymatic activity in inflamed joints.