RESUMO
The ability of noncytolytic Lyt-1+,2- T cells immune to FBL-3 leukemia to effect eradication of disseminated FBL-3 was studied. Adult thymectomized, irradiated, and T-depleted bone marrow-reconstituted (ATXBM) B6 hosts were cured of disseminated FBL-3 by treatment with 180 mg/kg cyclophosphamide (CY) and adoptively transferred Lyt-1+,2- T cells obtained from congenic B6/Thy-1.1 donors immune to FBL-3. Analysis of the T cell compartment of ATXBM hosts treated and rendered tumor-free by this therapy revealed that the only T cells present in the mice were donor-derived Lyt-1+,2- T cells. In vitro stimulation of these T cells with FBL-3 tumor cells, which express class I but no class II major histocompatibility complex antigens, induced lymphokine secretion, but did not result in the generation of cytotoxic T lymphocytes (CTL). Thus, in a setting in which mice lack Lyt-2+ T cells, and in which no CTL of either host or donor origin could be detected, immune Lyt-1+,2- T cells, in conjunction with CY, mediated eradication of a disseminated leukemia. The results suggest that delayed-type hypersensitivity responses induced by immune T cells represent a potentially useful effector mechanism for in vivo elimination of disseminated tumor cells.
Assuntos
Ciclofosfamida/uso terapêutico , Rejeição de Enxerto , Imunização Passiva/métodos , Leucemia Experimental/terapia , Linfócitos T/transplante , Animais , Antígenos Ly/genética , Antígenos de Histocompatibilidade Classe II/análise , Interferon gama/farmacologia , Leucemia Experimental/tratamento farmacológico , Leucemia Experimental/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Fenótipo , Quimera por Radiação , Baço/citologia , Linfócitos T/classificação , Linfócitos T/imunologia , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/transplanteRESUMO
Immunization of C57BL/6 (B6) mice with FBL, a Friend murine leukemia virus (F-MuLV), induces both tumor-specific cytolytic CD8+ (CTL) and lymphokine-producing CD4+ Th that are effective in adoptive therapy of B6 mice bearing disseminated FBL leukemia. The current study evaluated the F-MuLV antigenic determinants expressed on FBL that are recognized by FBL-reactive CD8+ and CD4+ T cells. To identify the specificity of the FBL-reactive CD8+ CTL, Fisher rat embryo fibroblast (FRE) cells transfected with plasmids encoding F-MuLV gag or envelope (env) gene products plus the class I-restricting element Db were utilized. FBL-reactive CTL recognized FRE target cells transfected with the F-MuLV gag-encoded gene products, but failed to recognize targets expressing F-MuLV env. Attempts to generate env-specific CD8+ CTL by immunization with a recombinant vaccinia virus containing an inserted F-MuLV env gene were unsuccessful, despite the generation of a cytolytic response to vaccinia epitopes, implying that B6 mice fail to generate CD8+ CTL to env determinants. By contrast, CD4+ Th clones recognized FRE target cells transfected with env and not gag genes, and immunization with the recombinant vaccinia virus induced an env-specific CD4+ T cell response. These data show that in a Friend retrovirus-induced tumor model in which tumor rejection can be mediated by either CTL or Th, antigens derived from discrete retroviral proteins are predominantly responsible for activation of each T cell subset.
Assuntos
Antígenos Virais/imunologia , Linfócitos T CD4-Positivos/imunologia , Vírus da Leucemia Murina de Friend/imunologia , Linfócitos T Citotóxicos/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Animais , Antígenos Virais/genética , Clonagem Molecular , Citotoxicidade Imunológica , Produtos do Gene gag , Antígenos de Histocompatibilidade Classe II/imunologia , Técnicas In Vitro , Ativação Linfocitária , Camundongos , Proteínas dos Retroviridae/genética , Proteínas dos Retroviridae/imunologia , Transfecção , Proteínas do Envelope Viral/imunologiaRESUMO
Tumors may contain immunogenic antigens that are only recognizable in the context of class I, and not of class II, MHC molecules. Therefore, methods were developed to analyze the capacity of Lyt-2+ T-cells to respond to a syngeneic tumor in the absence of a contribution by L3T4+ T-cells. Conditions were defined in which purified Lyt-2+ T-cell populations, as well as L3T4+ T-cell populations, isolated from immune B6 spleen cells, could be induced to proliferate specifically in response to FBL, a retrovirally induced syngeneic tumor, without the addition of exogenous lymphokines. The purity of the subset responses was documented functionally by selective inhibition of the proliferative response of only the appropriate subset following addition of anti-Kb/Db or anti-I-Ab. The antigen and accessory cell (AC) requirements for triggering immune Lyt-2+ and L3T4+ T-cell populations were examined. The response of L3T4+ populations was predominantly specific for retrovirus envelope gp70, whereas Lyt-2+ populations predominantly recognized tumor antigens other than gp70, consistent with the hypothesis that some tumor antigens may be preferentially recognized by only class I- or class II-restricted T-cells. The FBL-stimulated proliferative response of each T-cell subset was dependent upon the presence of syngeneic AC. However, exogenous interleukin 1 was able to replace AC during the response of Lyt-2+ populations, whereas L3T4+ populations required AC also to biochemically process tumor-derived antigen and present it in the context of class II MHC molecules. The results suggest that under some conditions only the presence of AC or interleukin 1 may be limiting for the induction of antitumor responses by Lyt-2+ populations. These studies analyzed the ability to trigger purified Lyt-2+ T-cells in vitro following in vivo priming to tumor, and it remained possible that L3T4+ T-cells made an essential contribution during in vivo priming. Therefore, L3T4(+)-deficient mice were primed with FBL in vivo, and the Lyt-2+ T-cell response was assessed. Although priming was clearly less efficient in the absence of L3T4+ T-cells, Lyt-2+ T-cells from L3T4(+)-deficient mice proliferated and became cytolytically active following stimulation with FBL. Thus, under appropriate conditions, Lyt-2+ T-cells can generate an effective antitumor response in the absence of L3T4+ T-cells or exogenous lymphokines.
Assuntos
Leucemia Experimental/imunologia , Ativação Linfocitária/imunologia , Macrófagos/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Animais , Células Apresentadoras de Antígenos/imunologia , Feminino , Vírus da Leucemia Murina de Friend/imunologia , Imunidade Celular , Interleucina-1/imunologia , Interleucina-2/imunologia , Isoanticorpos/imunologia , Macrófagos/citologia , Complexo Principal de Histocompatibilidade/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos CBA , Fenótipo , Proteínas Oncogênicas de Retroviridae/imunologia , Linfócitos T Auxiliares-Indutores/citologia , Proteínas do Envelope Viral/imunologiaRESUMO
Systemic interleukin 2 (IL-2) and IL-2-activated lymphocytes have induced tumor regression in some cancer patients. The IL-2-activated cells have usually been generated by obtaining peripheral blood mononuclear cells (PBMC) from cancer patients shortly after systemic IL-2 therapy and culturing them with IL-2 in vitro. In an effort to augment the ex vivo generation of such cells preactivated in vivo, we examined the proliferative responses of PBMC from IL-2-treated cancer patients to several proliferative signals including IL-2, interleukin 4 (IL-4), and mitogenic antibodies to CD3 and CD28. Although much is known about the response of normal PBMC to these signals, the possibility was considered that the response of lymphocytes preactivated by IL-2 in vivo might differ from that of normal PBMC. Accordingly, PBMC obtained from ten normal, healthy controls and from 17 patients with advanced cancer 1 to 3 days after systemic IL-2 therapy were cultured for 4 days with IL-4 (1000 units/ml) and/or IL-2 (10 units/ml or 1000 units/ml) or with combinations of IL-4 and anti-CD3 +/- anti-CD28, and they were then tested for proliferation by [3H]thymidine incorporation. IL-4 failed to induce proliferation of normal PBMC and inhibited IL-2-induced proliferation, whereas IL-4 alone induced proliferation in PBMC from five of 11 IL-2-treated patients and did not inhibit but augmented the proliferation induced by IL-2 (10 units/ml and 1000 units/ml) in PBMC from six of nine patients and five of 11 patients, respectively. Anti-CD3 induced proliferation in PBMC from eight of nine patients, and the proliferation was consistently augmented by coculture with anti-CD28. Finally, IL-4 significantly augmented the proliferative responses of PBMC from IL-2-treated patients to anti-CD3, as well as to the combination of anti-CD3 and anti-CD28. Thus, in PBMC from IL-2-treated cancer patients, IL-4 enhanced the in vitro proliferation induced by IL-2 or by anti-CD3 +/- anti-CD28. The results suggest that IL-4 and/or mitogenic antibodies may be useful in augmenting the ex vivo generation of lymphocytes for clinical adoptive immunotherapy.
Assuntos
Anticorpos/farmacologia , Neoplasias do Colo/patologia , Interleucina-2/farmacologia , Interleucina-4/farmacologia , Neoplasias Renais/patologia , Leucócitos Mononucleares/patologia , Linfoma Difuso de Grandes Células B/patologia , Melanoma/patologia , Adulto , Idoso , Antígenos de Diferenciação de Linfócitos T/imunologia , Antígenos CD28 , Complexo CD3 , Divisão Celular/efeitos dos fármacos , Neoplasias do Colo/terapia , Avaliação de Medicamentos , Interações Medicamentosas , Humanos , Interleucina-2/uso terapêutico , Neoplasias Renais/terapia , Ativação Linfocitária/efeitos dos fármacos , Linfoma Difuso de Grandes Células B/terapia , Melanoma/terapia , Pessoa de Meia-Idade , Receptores de Antígenos de Linfócitos T/imunologia , Linfócitos T/citologiaRESUMO
In an attempt to augment the generation of human cytotoxic effector cells for potential cancer therapy with interleukin 2 (IL2) and lymphokine-activated killer (LAK) cells, the effect of interleukin 4 (IL4) on LAK cell induction was studied. In normal human peripheral blood lymphocytes (PBL), IL4 does not induce LAK activity and inhibits LAK induction by IL2. However, since lymphocyte activation, such as with antigen or mitogen, can render them responsive to IL4, the ability of IL4 to induce LAK activity in lymphocytes preactivated in vivo or in vitro with IL2 was investigated. PBL obtained from 12 patients with advanced cancer 1 to 3 days after IL2 therapy and from eight healthy control subjects were cultured 4 to 5 days with or without IL4 and/or IL2 and then tested for LAK activity as assessed by lysis of Daudi in a 4-h 51Cr release assay. In normal PBL, IL4 failed to induce LAK activity and consistently inhibited LAK induction by a suboptimal concentration of IL2 (10 units/ml). By contrast, IL4 induced LAK activity in PBL from seven of twelve IL2-treated patients and augmented LAK induction by the suboptimal IL2 in PBL from five of twelve IL2-treated patients. With an optimal LAK-inducing concentration of IL2 (1000 units/ml), IL4 less consistently inhibited LAK induction in normal PBL and had a variable effect upon LAK induction in PBL from IL2-treated patients. IL4 induced LAK activity in PBL obtained from a cancer patient after, but not before, systemic IL2 therapy. Similarly, IL4 induced LAK activity in normal PBL only after they had been preincubated with IL2. Thus, IL4 induces LAK activity in lymphocytes preactivated by IL2 in vivo or in vitro. Fluorescence-activated cell sorting revealed that the LAK activity, whether induced by IL4 or by IL2, was mediated largely by non-T (CD5-) natural killer-like (CD56+) cells. The results suggest a regulatory relationship between IL2 and IL4 in the induction and/or maintenance of LAK activity, which might be exploited to augment the generation of cytotoxic cells for lymphokine-mediated immunotherapy of human cancer.
Assuntos
Citotoxicidade Imunológica , Interleucina-2/farmacologia , Interleucina-4/farmacologia , Células Matadoras Ativadas por Linfocina/imunologia , Antígenos CD/análise , Antígenos de Diferenciação , Antígenos de Diferenciação de Linfócitos T , Antígenos CD5 , Antígeno CD56 , Humanos , Técnicas In Vitro , Ativação Linfocitária/efeitos dos fármacosRESUMO
BACKGROUND: Despite high prevalence, emotional distress among primary care patients often goes unrecognized during routine medical encounters. OBJECTIVE: To explore the effect of communication-skills training on the process and outcome of care associated with patients' emotional distress. METHODS: A randomized, controlled field trial was conducted with 69 primary care physicians and 648 of their patients. Physicians were randomized to a no-training control group or one of two communication-skills training courses designed to help physicians address patients' emotional distress. The two training courses addressed communication through problem-defining skills or emotion-handling skills. All office visits of study physicians were audiotaped until five emotionally distressed and five nondistressed patients were enrolled based on patient response to the General Health Questionnaire. Physicians were also audiotaped interviewing a simulated patient to evaluate clinical proficiency. Telephone monitoring of distressed patients for utilization of medical services and General Health Questionnaire scores was conducted 2 weeks, 3 months, and 6 months after their audiotaped office visits. RESULTS: Audiotape analysis of actual and simulated patients showed that trained physicians used significantly more problem-defining and emotion-handling skills than did untrained physicians, without increasing the length of the visit. Trained physicians also reported more psychosocial problems, engaged in more strategies for managing emotional problems with actual patients, and scored higher in clinical proficiency with simulated patients. Patients of trained physicians reported reduction in emotional distress for as long as 6 months. CONCLUSIONS: Important changes in physicians' communication skills were evident after an 8-hour program. The training improved the process and outcome of care without lengthening the visits.
Assuntos
Comunicação , Educação Médica Continuada , Emoções , Estresse Psicológico/diagnóstico , Estresse Psicológico/prevenção & controle , Adulto , Competência Clínica , Feminino , Humanos , Masculino , Atenção Primária à Saúde , Inquéritos e Questionários , Gravação em FitaRESUMO
In vivo administration of mitomycin C (MMC) to C57BL/6J mice induced a rapid, initial suppression (24 hours post injection) of in vitro mitogenesis. This was followed by of the mitogen concentration-response curves were found of the three mitogens, phytohemagglutinin and concanavalin A, but not for lipopolysaccharide. By 144 hours post injection, the dose-response curves and magnitude of the responses had returned to approximately control (untreated) levels. This approach provides a model system for the functional assessment of in vivo cellular damage by MMC.
Assuntos
Troca Genética/efeitos dos fármacos , Mitomicinas/farmacologia , Troca de Cromátide Irmã/efeitos dos fármacos , Baço/citologia , Animais , Divisão Celular/efeitos dos fármacos , Concanavalina A/farmacologia , Relação Dose-Resposta a Droga , Lipopolissacarídeos/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Fito-Hemaglutininas/farmacologiaRESUMO
In vivo administration of mitomycin C (MMC) produces an increase in both the frequencies of sister chromatid exchange (SCE) as well as inhibition of in vitro mitogenic responses. At low concentrations of MMC (2 mg/kg) spleen cell suspensions from both young and old mice showed similar patterns of mitogen inhibition and increased SCE frequencies. At high MMC concentrations (5 mg/kg) significant differences between young and old responses were observed. Spleen cells from young animals displayed mitogen-inhibition curves which plateaued with increasing doses of MMC, while the cells from old animals displayed a continuing increase in mitogenic inhibition. MMC-induced SCE frequencies revealed a complementary pattern: increasing SCE frequencies as a function of MMC concentration in young spleen cells while SCE levels plateaued in old spleen cell populations. The results of these studies suggest (1) that an inverse relationship exists between sister chromatid exchange induction and mitogenic response, (2) that cells from older animals may have an increased sensitivity to high levels of DNA damage (5 mg/kg MMC), and (3) that this sensitivity may be expressed functionally by increased inhibition of in vitro mitogenic responses.
Assuntos
Envelhecimento , Troca Genética/efeitos dos fármacos , Mitomicinas/farmacologia , Troca de Cromátide Irmã/efeitos dos fármacos , Baço/citologia , Animais , Divisão Celular/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
OBJECTIVE: To determine the prognostic value of analyzing lymph node (LN) DNA from patients with mycosis fungoides for the presence of a monoclonal T-cell population. DESIGN: Inception cohort study. SETTING: A tertiary care referral center in Seattle, Wash. PATIENTS: Fifty-five uniformly staged patients with the diagnosis of mycosis fungoides and who had a lymph node biopsy, 21 with clinically abnormal nodes and 34 with normal nodes. MAIN OUTCOME MEASURES: Lymph nodes were evaluated by Southern blot analysis for T-cell receptor beta-chain (TCRB) gene rearrangement and by histopathologic examination for the LN classification using the National Cancer Institute system. Patients were observed clinically for a mean (+/- SD) of 4.7 +/- 3.4 years. RESULTS: Patients with detectable TCRB gene rearrangement in lymph node DNA had an increased likelihood of a poor clinical outcome and a decreased probability of survival (P < .001 for both) compared with patients with the TCRB germline. Although patients with clinically enlarged nodes were more likely to have the TCRB gene rearranged, those with normal nodes and the TCRB gene rearranged also had a poor clinical outcome and a decreased probability of survival. Similar to those with the TCRB gene rearranged, most patients with advanced histopathologic changes (LN3 and LN4) had a poor prognosis. The presence of a rearranged TCRB gene, however, correctly predicted some patients with intermediate LN scores (LN2) who had a poor clinical outcome. CONCLUSIONS: Detection of a monoclonal T-cell population, as demonstrated by a rearranged TCRB gene on Southern blot analysis, in LNs of patients with mycosis fungoides is predictive of a poor clinical outcome and a reduced probability of survival. Lymph node TCRB gene analysis provides additional prognostic information for patients with mycosis fungoides with intermediate LN histopathology.
Assuntos
Rearranjo Gênico da Cadeia beta dos Receptores de Antígenos dos Linfócitos T/genética , Linfonodos/metabolismo , Micose Fungoide/genética , Neoplasias Cutâneas/genética , Antineoplásicos/uso terapêutico , Biópsia , Southern Blotting , Causas de Morte , Estudos de Coortes , Intervalos de Confiança , DNA de Neoplasias/análise , DNA de Neoplasias/genética , Progressão da Doença , Feminino , Seguimentos , Humanos , Linfonodos/patologia , Linfoma Cutâneo de Células T/patologia , Masculino , Pessoa de Meia-Idade , Micose Fungoide/patologia , Estadiamento de Neoplasias , Probabilidade , Prognóstico , Estudos Prospectivos , Indução de Remissão , Reprodutibilidade dos Testes , Neoplasias Cutâneas/patologia , Taxa de Sobrevida , Linfócitos T/metabolismo , Linfócitos T/patologia , Resultado do TratamentoRESUMO
PURPOSE: In 1983, 43% of internal medicine residency program directors had held their positions for less than three years. The purposes of this study were to determine the job turnover rate for internal medicine program directors, and the characteristics of program directors and residency programs that are associated with job turnover. METHOD: In October 1996, questionnaires were sent to all non-military internal medicine residency program directors in the continental United States listed by the Accreditation Council for Graduate Medical Education (ACGME). The questionnaire covered demographics, program characteristics, and job satisfaction. In October 1999, an updated ACGME list was used to contact programs to verify changes in program directors and determine the dates of change. RESULTS: A total of 262 usable responses were received. At the beginning of the study, 49% of the respondents had been on the job for three years or less, and 74 (29%) were no longer program directors three years later. Overall job satisfaction was highly associated (p <.01) with turnover. Multivariate Cox regression modeling yielded four variables independently associated with turnover: low satisfaction with colleague relationships (hazard ratio = 3.2, 95% CI = 1.6-6.4), a high percentage of administrative work time (HR = 2.9, 95% CI = 1.4-6.2), perceiving the job as a "stepping stone" (HR = 1.8, 95% CI = 1.0-3.2), and having had formal training to deal with problem residents (HR = 0.6, 95% CI = 0.4-1.1). Respondents with burnout, with the titles of program director and chair or department chief, and with less than two years on the job had nonsignificant trends toward job turnover. Variables not associated with turnover included gender, rank, salary, and program size. CONCLUSIONS: Yearly turnover for internal medicine residency program directors is substantial. The four independent predictors of turnover identified in this study should be of interest to institutions recruiting or retaining program directors and to aspiring program directors.
Assuntos
Medicina Interna/organização & administração , Medicina Interna/estatística & dados numéricos , Internato e Residência/organização & administração , Internato e Residência/estatística & dados numéricos , Reorganização de Recursos Humanos/estatística & dados numéricos , Diretores Médicos/organização & administração , Diretores Médicos/estatística & dados numéricos , Adulto , Estudos de Coortes , Feminino , Humanos , Satisfação no Emprego , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Modelos de Riscos Proporcionais , Análise de Regressão , Inquéritos e Questionários , Fatores de Tempo , Carga de Trabalho/estatística & dados numéricosRESUMO
PURPOSE: To develop a job-satisfaction measure that encompasses the multifaceted job of internal medicine residency program directors. METHOD: Questions were devised to measure program directors satisfaction with various facets of their jobs. In 1996, the authors surveyed all non-military internal medicine program directors in the United States. RESULTS: Of the program directors surveyed, 301 (78%) responded. More respondents than non-respondents held the title of department chairperson in addition to the title of program director (22% vs 7%). Factor analysis and correlation analysis yielded a multifaceted measure (termed PD-Sat) composed of 20 questions and six facets (work with residents, colleague relationships, resources, patient care, pay, and promotion) that made sense based on literature review and discussions with program directors (face validity). The PD-Sat had good internal reliability (Cronbach's alpha = .88), as had each of its six facets (Cronbach's alphas = .60-.90). The six facets correlated modestly with one another (Pearson's r2 = .12-.67), suggesting they were measuring different aspects of a common concept. The PD-Sat correlated significantly with an established four-question global job-satisfaction scale used in previous studies (Pearson's r2 = .33) demonstrating concurrent validity. Scores on the PD-Sat predicted whether program directors were considering, seeking, or making a job change (predictive validity). The PD-Sat performed comparably well in subsets of program directors who were and were not department chairs, suggesting that it might be applicable to different populations of program directors. CONCLUSION: The authors have developed a new facet-specific job-satisfaction measure that is reliable and valid for assessing the job satisfaction of internal medicine program directors. Because job descriptions for program directors in other specialties are similar, it may also be useful in these populations.
Assuntos
Medicina Interna/educação , Internato e Residência , Satisfação no Emprego , Diretores Médicos/psicologia , Adulto , Idoso , Escolha da Profissão , Mobilidade Ocupacional , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inventário de Personalidade/estatística & dados numéricos , Desenvolvimento de Programas , Psicometria , Reprodutibilidade dos Testes , Estados UnidosAssuntos
Interleucina-2/farmacologia , Ativação Linfocitária , Linfócitos T Citotóxicos/imunologia , Animais , Anticorpos Monoclonais/imunologia , Interleucina-2/imunologia , Interleucina-2/isolamento & purificação , Teste de Cultura Mista de Linfócitos , Linfoma/imunologia , Linfoma/metabolismo , Camundongos , Camundongos Nus , Receptores de Antígenos de Linfócitos TRESUMO
Knowledge of the prevalence (or pretest probability) of a disease is necessary for the interpretation of the results of a diagnostic test in a specific population of patients. This paper evaluates a formula for estimating the prevalence of a disease in a population, based on the proportion of patients with abnormal test results in that population and the known sensitivity and specificity of the test. The authors tested the formula by using it to estimate the prevalence of myocardial infarction in 215 patients with chest pain admitted to a coronary care unit, based on results of initial total creatine kinase determinations. The estimated prevalence was 30%. The true prevalence of myocardial infarction, based on established diagnostic criteria, was 25% (95% confidence interval 19.2%-30.8%). To further evaluate the formula, a sensitivity analysis was performed. Errors in estimated prevalence were inversely related to test sensitivity and specificity, positively related to the magnitude of the differences between presumed and true test sensitivity and specificity, and complexly related to the true prevalence of disease. This formula permits the estimation of prevalence of a disease in a population without resorting to the use of a "gold standard" test, which is often invasive or impractical. Situations are presented where the formula could be used to evaluate and improve the utilization of laboratory tests.
Assuntos
Teorema de Bayes , Valor Preditivo dos Testes , Prevalência , Probabilidade , Idoso , Creatina Quinase/sangue , Estudos de Avaliação como Assunto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/sangue , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/epidemiologia , Embolia Pulmonar/diagnóstico por imagem , Embolia Pulmonar/epidemiologia , Embolia Pulmonar/fisiopatologia , Radiografia , Relação Ventilação-PerfusãoRESUMO
The requirements for inducing Lyt-2+ T cell proliferation in response to concanavalin A (Con A) were examined. Purified Lyt-2+ or L3T4+ spleen cells of C57BL/6 origin were stimulated with Con A and syngeneic macrophages (MO) in the presence of monoclonal antibodies to T cell markers or to polymorphic determinants on major histocompatibility complex molecules, and assessed for the ability to proliferate and to produce interleukin (IL) 2. alpha I-Ab failed to inhibit the Con A response of Lyt-2+ cells at dilutions that significantly inhibited the response of L3T4+ cells. In contrast, alphaKb/Db or alpha Lyt-2.2 specifically inhibited the response of Lyt-2+ cells, but not L3T4+ cells. The ability of alpha Kb/Db and of alpha Lyt-2.2 to inhibit the response of Lyt-2+ cells was dependent upon the concentration of Con A. These data demonstrate that optimal triggering of T cell subsets to proliferate and to produce IL-2 in response to Con A requires interactions with the appropriate restricting major histocompatibility complex molecule. The role of accessory cells in Lyt-2+ Con A-induced proliferation and IL-2 production was also investigated. Purified Lyt-2+ cells and purified L3T4+ cells failed to respond to Con A in the absence of MO. IL-1 reconstituted the response when MO were limiting, but failed to restore the response of either Lyt-2+ or L3T4+ cells when T cells were rigorously purified to remove all MO. These results demonstrate that triggering Lyt-2+ T cells, like L3T4+ T cells, requires accessory cells, and that this does not merely reflect a requirement for IL-1 production. Thus, Con A-induced proliferation and IL-2 production by Lyt-2+ T cells requires intimate contact with accessory cells and interactions dependent upon the class I-restricting element.
Assuntos
Antígenos de Diferenciação de Linfócitos T/imunologia , Antígenos Ly/imunologia , Linfócitos T/imunologia , Animais , Reações Antígeno-Anticorpo , Células Apresentadoras de Antígenos/imunologia , Concanavalina A/farmacologia , Antígenos de Histocompatibilidade/imunologia , Interleucina-1/fisiologia , Interleucina-2/biossíntese , Isoanticorpos/imunologia , Ativação Linfocitária , Cooperação Linfocítica , Macrófagos/imunologia , Camundongos , Linfócitos T Citotóxicos/imunologia , Linfócitos T Auxiliares-Indutores/imunologiaRESUMO
This study was designed to measure the effect of altering three possible impediments to care provided patients with non-emergency problems in a large city hospital emergency department: inadequate patient education by physician, lack of continuity of care, and complex and impersonal clerical procedures. Patients with symptomatic urinary tract infections were randomly assigned to intervention and control groups. A senior physician spent extra time with patients in the intervention group to discuss the assessment and management of their problem, bypass the usual clerical procedures at discharge, and promise continuity of care. Patients in the control group were treated in the usual fashion by emergency department nurses and residents. The return rate to the emergency department three weeks after the initial visit was used to measure the effect of the altered care applied to patients in the intervention group. Our hypothesis was that patients in the intervention group would be more likely to return. Of 46 patients in the intervention group 26 returned. Of 43 patients in the control group, 14 returned (chi square 4.23 after Yate's correction, 0.025 less than P less than 0.05). The significance of this improvement is discussed.
Assuntos
Continuidade da Assistência ao Paciente , Serviço Hospitalar de Emergência , Cooperação do Paciente , Relações Médico-Paciente , Atenção Primária à Saúde , Ensaios Clínicos como Assunto , Hospitais Municipais , Humanos , Ohio , Distribuição AleatóriaRESUMO
The influence of the route and the frequency of IL 2 administration on the ability of IL 2 to induce the growth of activated T cells in vivo was evaluated. Initial pharmacokinetic studies confirmed that i.v. injection of IL 2 results in a relatively high peak serum concentration, but a short serum half-life. By contrast, i.p. or subcutaneous (s.c.) injection of IL 2 results in a lower peak concentration but a prolonged serum half-life. The bioavailability of IL 2 administered by these routes was assessed by measuring the in vivo growth of adoptively transferred T cells that had been previously cultured long-term with IL 2, because the growth of such cells in vivo has been shown to be proportional to the dose of IL 2 administered. The results demonstrated that i.p., s.c., or i.v. administration of IL 2 each resulted in marked donor T cell growth in vivo. Thus, IL 2 can function in vivo at sites distant to the sites of injection. In addition, the magnitude of T cell growth in vivo varied dependent on the route of IL 2 administration and correlated with the length of time IL 2 was detectable in serum, rather than the peak level achieved (i.e., IL 2 inoculated i.v. had the highest peak concentration but was least effective). As suggested by these findings, dividing the total dose of IL 2 into frequent low-dose injections was more effective in inducing T cell growth in vivo than was dividing the total dose of IL 2 into less frequent higher-dose injections. These studies confirm the great potential for IL 2 to induce the growth of activated of T cells in vivo and demonstrate that the rate of T cell growth reflects not only the dose but also the route and timing of IL 2 administration.
Assuntos
Interleucina-2/administração & dosagem , Ativação Linfocitária , Linfócitos T/citologia , Animais , Divisão Celular , Relação Dose-Resposta Imunológica , Esquema de Medicação , Injeções Intraperitoneais , Injeções Intravenosas , Injeções Subcutâneas , Interleucina-2/fisiologia , Cinética , Camundongos , Camundongos Endogâmicos C57BL , Linfócitos T/imunologiaRESUMO
The roles of Class II-restricted L3T4+ T cells and of accessory cells (AC) during the in vitro generation of Class I-restricted Lyt-2+ cytotoxic T cells (CTL) specific for a Class II-negative syngeneic tumor cell line, FBL, was examined. Treatment of responder FBL-immune spleen cells with alpha L3T4 plus complement before culture, as well as the direct addition of alpha L3T4 to cultures, diminished the generation of FBL-specific CTL. The contribution of L3T4+ cells could be completely replaced by the addition of exogenous cytokines. The data demonstrate that the optimal generation of FBL-specific Lyt-2+ CTL requires the presence of L3T4+ cells, presumably to provide necessary lymphokines. FBL-specific CTL could not be generated from purified FBL-immune T cells in the absence of AC. Syngeneic Ia+ macrophages (M phi), added at the initiation of culture, restored the response of purified T cells. Pretreatment of M phi with ammonium chloride or chloroquine, or the addition of monoclonal alpha I-Ab antibody at the initiation of culture, inhibited the ability of M phi to reconstitute the CTL response. Finally, the addition of exogenous helper factors could replace M phi and reconstitute the FBL-specific response of AC-depleted immune T cells. These results suggest that during the generation of Lyt-2+ CTL to a syngeneic tumor expressing only Class I MHC antigens, Ia+ AC are required to biochemically process antigen released from the tumor cells and present this modified antigen to Class II-restricted T helper cells.
Assuntos
Células Apresentadoras de Antígenos/metabolismo , Antígenos de Neoplasias/análise , Antígenos H-2/genética , Antígenos de Histocompatibilidade Classe II/análise , Linfócitos T Citotóxicos/imunologia , Animais , Células Apresentadoras de Antígenos/imunologia , Antígenos de Diferenciação de Linfócitos T , Antígenos Ly/análise , Antígenos de Neoplasias/imunologia , Antígenos de Superfície/análise , Comunicação Celular , Epitopos/imunologia , Feminino , Antígenos H-2/análise , Antígenos de Histocompatibilidade Classe II/imunologia , Leucemia Eritroblástica Aguda/imunologia , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos AKR , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Camundongos Nus , Monocinas , Proteínas/farmacologia , Linfócitos T Citotóxicos/metabolismoRESUMO
OBJECTIVE: To evaluate the effectiveness of a process whereby a faculty-resident committee annually audits outpatient record keeping and preventive care practices and provides feedback to resident physicians. DESIGN: Pre- and postfeedback audits with interventions and observations repeated over six consecutive academic years. SETTING: The adult primary care practice of housestaff in a university-affiliated hospital. SUBJECTS: All 139 physicians in an internal medicine residency program from 1981-82 through 1986-87, of whom 37 were present for three consecutive years. INTERVENTION: Each year, residents were given individualized, detailed, typewritten feedback based on audits of their outpatient records. MEASUREMENTS AND MAIN RESULTS: Each resident physician had a minimum of four (mean 5.2) outpatient records per year audited against standards for record-keeping practices and the provision of preventive care. Overall performance scores for each resident audit improved from a mean of 39.7 +/- 12.3 (SD) in 1981-82 to a mean of 58.5 +/- 14.1 (SD) in 1986-87 (possible range 0 to 100, observed range 9.4 to 86.6). The overall performance scores of individual residents, who received two cycles of feedback, improved an average of 11.5 (95% confidence limits 7.6, 15.3), from a mean of 48.4 +/- 11.4 (SD) during their first year of residency to 59.8 +/- 13.9 (SD) during their third year. General (primary care) and traditional-track residents improved at similar rates, although mean performance scores were consistently higher for general than for traditional-track residents. Analysis of variance revealed that all changes and differences were statistically significant. CONCLUSIONS: An ongoing chart audit and feedback system can be associated with improvements both in the performance of individual residents and in the long-term performance of a residency program.
Assuntos
Competência Clínica/estatística & dados numéricos , Medicina Interna/educação , Internato e Residência/normas , Auditoria Médica , Baltimore , Retroalimentação , Hospitais com mais de 500 Leitos , Humanos , Prontuários Médicos , Ambulatório Hospitalar/normas , Fatores de TempoRESUMO
Macrophage activation factor (MAF) activity, assessed by the ability to activate macrophages (MO) to lyse RBL--a TNF-resistant, retrovirally transformed, tumor target--was detected in the PHA-stimulated supernatant (Sup) of LBRM, a murine T cell line. LBRM Sup provided a priming signal to MO, but required the subsequent addition of small amounts of LPS for the expression of tumor cytotoxicity. The identity of the lymphokine responsible for this MAF activity was investigated. IFN-gamma, the only previously characterized lymphokine capable of priming MO for tumor cytotoxicity, did have MAF activity in the assay, but IFN-gamma could not be detected by ELISA in LBRM Sup, and LBRM-derived mRNA lacked detectable message for IFN-gamma. Moreover, anti-IFN-gamma failed to inhibit the MAF activity of LBRM Sup, suggesting that the presence of small, undetectable amounts of IFN-gamma were neither responsible nor required for LBRM MAF activity. LBRM MAF activity appeared distinct from the other previously identified lymphokines produced by LBRM, since granulocyte-macrophage-CSF, IL-2, and IL-3 purified from LBRM Sup were unable to activate MO to lyse RBL. IL-4 and TNF, two lymphokines not known to be produced by LBRM but able to activate MO for cytotoxicity of some tumor targets, were also unable to activate MO for RBL cytotoxicity. LBRM MAF lacked antiviral activity in biologic assays, further distinguishing the lymphokine from IFN-gamma, and had an apparent Mr of 30,000 Da using gel filtration chromatography. Thus, the LBRM T cell line produces a previously undescribed lymphokine that primes MO for tumor cytotoxicity.
Assuntos
Citotoxicidade Imunológica , Linfocinas/isolamento & purificação , Linfoma/imunologia , Ativação de Macrófagos , Linfócitos T/metabolismo , Animais , Linhagem Celular , Sistema Livre de Células , Feminino , Células Matadoras Naturais/imunologia , Linfocinas/biossíntese , Linfocinas/fisiologia , Fatores Ativadores de Macrófagos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Peso Molecular , Linfócitos T/imunologia , Células Tumorais Cultivadas , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
Competent use of interviewing skills is important for the care of all patients but is especially critical, and frequently deficient, in meeting the needs of patients experiencing emotional distress. This study presents an evaluation of a curriculum in communication and psychosocial skills taught to first-year medical residents. A randomized experimental design compared trained and untrained residents' (n = 48) performances with a simulated patient presenting with atypical chest pain and psychosocial distress. Evaluation was based on analysis of videotapes, simulated patient report of residents' behaviors, and chart notation. Trained compared with untrained residents asked more open-ended questions and fewer leading questions, summarized main points more frequently, did more psychosocial counseling, and were rated as having better communication skills by the simulated patient. The use of more focused and psychosocially directed questions, and fewer leading and grab-bag questions, was associated with more accurate diagnoses and management recorded in the medical chart. However, no significant difference was found in the charting practices of trained versus untrained residents.