Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 79
Filtrar
1.
BMC Health Serv Res ; 19(1): 877, 2019 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-31752866

RESUMEN

BACKGROUND: In the move toward value-based care, bundled payments are believed to reduce waste and improve coordination. Some commercial insurers have addressed this through the use of bundled payment, the provision of one fee for all care associated with a given index procedure. This system was pioneered by Medicare, using a population generally over 65 years of age, and despite its adoption by mainstream insurers, little is known of bundled payments' ability to reduce variation or cost in a working-age population. This study uses a universally-insured, nationally-representative population of adults aged 18-65 to examine the effect of bundled payments for five high-cost surgical procedures which are known to vary widely in Medicare reimbursement: hip replacement, knee replacement, coronary artery bypass grafting (CABG), lumbar spinal fusion, and colectomy. METHODS: Five procedures conducted on adults aged 18-65 were identified from the TRICARE database from 2011 to 2014. A 90-day period from index procedure was used to determine episodes of associated post-acute care. Data was sorted by Zip code into hospital referral regions (HRR). Payments were determined from TRICARE reimbursement records, they were subsequently price standardized and adjusted for patient and surgical characteristics. Variation was assessed by stratifying the HRR into quintiles by spending for each index procedure. RESULTS: After adjusting for case mix, significant inter-quintile variation was observed for all procedures, with knee replacement showing the greatest variation in both index surgery (107%) and total cost of care (75%). Readmission was a driver of variation for colectomy and CABG, with absolute cost variation of $17,257 and $13,289 respectively. Other post-acute care spending was low overall (≤$1606, for CABG). CONCLUSIONS: This study demonstrates significant regional variation in total spending for these procedures, but much lower spending for post-acute care than previously demonstrated by similar procedures in Medicare. Targeting post-acute care spending, a common approach taken by providers in bundled payment arrangements with Medicare, may be less fruitful in working aged populations.


Asunto(s)
Gastos en Salud/estadística & datos numéricos , Programas Controlados de Atención en Salud/economía , Mecanismo de Reembolso , Procedimientos Quirúrgicos Operativos/economía , Adolescente , Adulto , Anciano , Artroplastia de Reemplazo de Cadera/economía , Artroplastia de Reemplazo de Rodilla/economía , Colectomía/economía , Puente de Arteria Coronaria/economía , Grupos Diagnósticos Relacionados , Femenino , Reforma de la Atención de Salud/legislación & jurisprudencia , Humanos , Masculino , Persona de Mediana Edad , Personal Militar , Fusión Vertebral/economía , Atención Subaguda/economía , Estados Unidos , Veteranos , Adulto Joven
2.
Br J Surg ; 104(10): 1372-1381, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28632890

RESUMEN

BACKGROUND: A critical appraisal of the benefits of minimally invasive surgery (MIS) is needed, but is lacking. This study examined the associations between MIS and 30-day postoperative outcomes including complications graded according to the Clavien-Dindo classification, unplanned readmissions, hospital stay and mortality for five common surgical procedures. METHODS: Patients undergoing appendicectomy, colectomy, inguinal hernia repair, hysterectomy and prostatectomy were identified in the American College of Surgeons National Surgical Quality Improvement Program database. Non-parsimonious propensity score methods were used to construct procedure-specific matched-pair cohorts that reduced baseline differences between patients who underwent MIS and those who did not. Bonferroni correction for multiple comparisons was applied and P < 0·006 was considered significant. RESULTS: Of the 532 287 patients identified, 53·8 per cent underwent MIS. Propensity score matching yielded an overall sample of 327 736 patients (appendicectomy 46 688, colectomy 152 114, inguinal hernia repair 59 066, hysterectomy 59 066, prostatectomy 10 802). Within the procedure-specific matched pairs, MIS was associated with significantly lower odds of Clavien-Dindo grade I-II, III and IV complications (P ≤ 0·004), unplanned readmissions (P < 0·001) and reduced hospital stay (P < 0·001) in four of the five procedures studied, with the exception of inguinal hernia repair. The odds of death were lower in patients undergoing MIS colectomy (P < 0·001), hysterectomy (P = 0·002) and appendicectomy (P = 0·002). CONCLUSION: MIS was associated with significantly fewer 30-day postoperative complications, unplanned readmissions and deaths, as well as shorter hospital stay, in patients undergoing colectomy, prostatectomy, hysterectomy or appendicectomy. No benefits were noted for inguinal hernia repair.


Asunto(s)
Procedimientos Quirúrgicos Mínimamente Invasivos/efectos adversos , Readmisión del Paciente , Complicaciones Posoperatorias/mortalidad , Apendicectomía/efectos adversos , Apendicectomía/economía , Colectomía/efectos adversos , Colectomía/economía , Gastos en Salud , Herniorrafia/efectos adversos , Herniorrafia/economía , Humanos , Histerectomía/efectos adversos , Histerectomía/economía , Procedimientos Quirúrgicos Mínimamente Invasivos/economía , Readmisión del Paciente/economía , Complicaciones Posoperatorias/economía , Puntaje de Propensión , Prostatectomía/efectos adversos , Prostatectomía/economía , Resultado del Tratamiento , Estados Unidos
3.
J Med Ethics ; 35(3): 183-8, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19251971

RESUMEN

OBJECTIVES: To report the attitudes and opinions of subjects in US clinical trials about whether or not, and why, they should receive post-trial access (PTA) to the trial drug, care and information. DESIGN: Focus groups, short self-administered questionnaires. SETTING: Boston, Dallas, Detroit, Oklahoma City. PARTICIPANTS: Current and recent subjects in clinical trials, primarily for chronic diseases. RESULTS: 93 individuals participated in 10 focus groups. Many thought researchers, sponsors, health insurers and others share obligations to facilitate PTA to the trial drug, if it benefited the subject, or to a therapeutic equivalent. Some thought PTA obligations include providing transition care (referrals to non-trial physicians or other trials, limited follow-up, short-term drug supply) or care for long-term adverse events. Others held, in contrast, that there are no PTA obligations regarding drugs or care. However, there was agreement that former subjects should receive information (drug name, dosage received, market approval date, long-term adverse effects, trial results). Participants frequently appealed to health need, cost, relationships, reciprocity, free choice and sponsor self-interest to support their views. Many of their reasons overlapped with those commonly discussed by bioethicists. CONCLUSION: Many participants in US trials for chronic conditions thought there are obligations to facilitate PTA to the trial drug at a "fair" price; these views were less demanding than those of non-US subjects in other studies. However, our participants' views about informational obligations were broader than those of other subjects and many bioethicists. Our results suggest that the PTA debate should expand beyond the trial drug and aggregate results.


Asunto(s)
Ensayos Clínicos como Asunto/ética , Continuidad de la Atención al Paciente/ética , Accesibilidad a los Servicios de Salud/ética , Obligaciones Morales , Sujetos de Investigación/psicología , Adulto , Anciano , Ensayos Clínicos como Asunto/psicología , Femenino , Grupos Focales , Humanos , Masculino , Persona de Mediana Edad , Preparaciones Farmacéuticas/provisión & distribución , Encuestas y Cuestionarios , Estados Unidos , Adulto Joven
4.
Methods ; 40(4): 344-52, 2006 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17101447

RESUMEN

The use of the budding yeast Saccharomyces cerevisiae as a simple eukaryotic model system for the study of chromatin assembly and regulation has allowed rapid discovery of genes that influence this complex process. The functions of many of the proteins encoded by these genes have not yet been fully characterized. Here, we describe a high-throughput methodology that can be used to illuminate gene function and discuss its application to a set of genes involved in the creation, maintenance and remodeling of chromatin structure. Our technique, termed E-MAPs, involves the generation of quantitative genetic interaction maps that reveal the function and organization of cellular proteins and networks.


Asunto(s)
Cromatina/metabolismo , Epistasis Genética , Mapeo de Interacción de Proteínas , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/genética , Cromatina/genética , Ensamble y Desensamble de Cromatina , Biología Computacional , Análisis de Secuencia por Matrices de Oligonucleótidos , Saccharomyces cerevisiae/metabolismo
5.
Acad Med ; 76(11): 1119-26, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11704515

RESUMEN

PURPOSE: To understand the effect of market competition on patient-oriented research at U.S. medical schools and teaching hospitals. METHOD: From a multi-stage stratified, random sample, the authors surveyed 3,804 research faculty at 117 U.S. medical schools. The questionnaire assessed five variables, the type of research conducted by the respondent, changes in patient-oriented and non-clinical research in the preceding three years, amount of time spent on patient care, market stage of the respondent's institution, and research productivity. RESULTS: Of the 2,336 faculty who responded (62%), 84% of those conducting patient-oriented research and 80% of those engaged in non-clinical research reported conducting the same amount of research or more in 1996-1997 than in the preceding three years. However, both patient-oriented and non-clinical researchers in the most competitive health care markets and those with high levels of patient care duties were most likely to report decreases in the amounts of such research conducted in the previous three years. Further, researchers reporting such decreases had been as productive in recent years and over their careers as had those who did not report a decrease. CONCLUSIONS: This study provides additional evidence of the negative relationships that exist between high levels of market competition and patient care services on the patient-oriented and non-clinical research missions of teaching hospitals.


Asunto(s)
Competencia Económica , Docentes Médicos/organización & administración , Hospitales de Enseñanza/organización & administración , Experimentación Humana/economía , Comercialización de los Servicios de Salud , Investigación/organización & administración , Facultades de Medicina/organización & administración , Recolección de Datos , Femenino , Humanos , Masculino , Atención al Paciente/economía , Estados Unidos , Carga de Trabajo
6.
Annu Rev Genet ; 35: 149-91, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11700281

RESUMEN

The endoplasmic reticulum (ER) serves as a way-station during the biogenesis of nearly all secreted proteins, and associated with or housed within the ER are factors required to catalyze their import into the ER and facilitate their folding. To ensure that only properly folded proteins are secreted and to temper the effects of cellular stress, the ER can target aberrant proteins for degradation and/or adapt to the accumulation of misfolded proteins. Molecular chaperones play critical roles in each of these phenomena.


Asunto(s)
Chaperonas Moleculares/metabolismo , Proteínas/metabolismo , Animales , Transporte Biológico , Retículo Endoplásmico/metabolismo , Humanos , Proteínas de la Membrana/metabolismo , Chaperonas Moleculares/inmunología , Pliegue de Proteína , Control de Calidad
7.
Mol Cell ; 8(4): 730-2, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11684006

RESUMEN

Two papers recently published in Cell investigate the role of protein encapsulation by GroEL in assisting folding. The first shows how encapsulation can "smooth" the folding landscape, accelerating folding of some proteins. The second defines a confinement-independent pathway, which allows GroEL to assist folding of substrates too large to be encapsulated.


Asunto(s)
Chaperonina 60/metabolismo , Pliegue de Proteína , Adenosina Trifosfato/metabolismo , Dominio Catalítico , Chaperonina 10/metabolismo , Chaperonina 60/química , Escherichia coli/enzimología , Escherichia coli/metabolismo , Ligandos , Modelos Biológicos , Conformación Proteica , Ribulosa-Bifosfato Carboxilasa
8.
Ann Intern Med ; 135(5): 328-37, 2001 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-11529696

RESUMEN

BACKGROUND: Coronary artery bypass graft (CABG) surgery and percutaneous transluminal coronary angioplasty (PTCA) are well-established treatments for symptomatic coronary artery disease. Previous studies have documented racial differences in rates of use of these cardiac revascularization procedures. Other studies suggest that these procedures are overused: that is, they are done for patients with clinically inappropriate indications. OBJECTIVE: To test the hypothesis that the higher rate of cardiac revascularization among white patients is associated with a higher prevalence of overuse (revascularization for clinically inappropriate indications) among white patients than among African-American patients. DESIGN: Observational cohort study using Medicare claims and medical record review. SETTING: 173 hospitals in five U.S. states. PARTICIPANTS: A stratified, weighted, random sample of 3960 Medicare beneficiaries who underwent coronary angiography during 1991 and 1992; 1692 of these patients underwent 1711 revascularization procedures within 90 days. MEASUREMENTS: The proportion of CABG and PTCA procedures rated appropriate, uncertain, and inappropriate according to RAND criteria, and the multivariate odds of undergoing inappropriate revascularization among African-American patients and white patients. RESULTS: After angiography, rates of PTCA (23% vs. 19%) and CABG surgery (29% vs. 17%) were significantly higher among white patients than among African-American patients. The respective rates of inappropriate PTCA and CABG surgery were 14% and 10%. Among the study states, rates of inappropriate use ranged from 4% to 24% for PTCA and 0% to 14% for CABG surgery. White patients were more likely than African-American patients to receive inappropriate PTCA (15% vs. 9%; difference, 6 percentage points [95% CI, -0.4 to 12.7 percentage points]), and difference by race was statistically significant among men (20% vs. 8%; difference, 12 percentage points [CI, 1.2 to 21.7 percentage points]). Rates of inappropriate CABG surgery did not differ by race (10% in both groups). CONCLUSIONS: Among a large and diverse sample of Medicare beneficiaries in five U.S. states, overuse of PTCA was greater among white men than among other groups, but this difference did not fully account for racial disparities in revascularization. Overuse of cardiac revascularization varied significantly by geographic region.


Asunto(s)
Angioplastia Coronaria con Balón/estadística & datos numéricos , Población Negra , Puente de Arteria Coronaria/estadística & datos numéricos , Enfermedad Coronaria/etnología , Enfermedad Coronaria/terapia , Mal Uso de los Servicios de Salud/estadística & datos numéricos , Población Blanca , Anciano , Estudios de Cohortes , Femenino , Humanos , Renta , Masculino , Medicare , Oportunidad Relativa , Factores Sexuales , Estados Unidos
10.
J Urban Health ; 78(3): 535-49, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11564855

RESUMEN

Access to care by low-income persons and residents of rural and poor inner-city areas is a persistent problem, yet physicians tend to be maldistributed relative to need. The objectives were to describe preferences of resident physicians to locate in underserved areas and to assess their preparedness to provide service to low-income populations. A national survey was made of residents completing their training in eight specialties at 162 US academic health center hospitals in 1998, with 2,626 residents responding. (Of 4,832 sampled, 813 had invalid addresses or were no longer in the residency program. Among the valid sample of 4,019, the response rate was 65%.) The percentage of residents ranking public hospitals, rural areas, and poor inner-city areas as desirable employment locations and the percentage feeling prepared to provide specified services associated with indigent populations were ascertained. Logistic regressions were used to calculate adjusted percentages, controlling for sex, race/ethnicity, international medical graduate (IMG) status, plans to subspecialize, ownership of hospital, specialty, and exposure to underserved patients during residency. Only one third of residents rated public hospitals as desirable settings, although there were large variations by specialty. Desirability was not associated with having trained in a public hospital or having greater exposure to underserved populations. Only about one quarter of respondents ranked rural (26%) or poor inner-city (25%) areas as desirable. Men (29%, P <.01) and noncitizen IMGs (43%, P <.01) were more likely than others to prefer rural settings. Residents who were more likely to rate poor inner-city settings as desirable included women (28%, P =.03), noncitizen IMGs (35%, P =.01), and especially underrepresented minorities (52%, P <.01). Whereas about 90% or more of residents felt prepared to treat common clinical conditions, only 67% of residents in four primary care specialties felt prepared to counsel patients about domestic violence or to care for human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) or substance abuse patients (all 67%). Women were more likely than men to feel prepared to counsel patients about domestic violence (70% vs. 63%, P =.002) and depression (83% vs. 75%, P <.01). Underrepresented minority residents were more likely than other residents to feel prepared to counsel patients about domestic violence (P <.01) and compliance with care (P =.04). Residents with greater exposure to underserved groups were more prepared to counsel patients about domestic violence (P =.01), substance abuse (P =.01), and to treat patients with HIV/AIDS (P =.01) or with substance abuse problems (P <.01). This study demonstrates the need to expose graduate trainees to underserved populations and suggests a continuing role of minorities, women, and noncitizen physicians in caring for low-income populations.


Asunto(s)
Fuerza Laboral en Salud , Hospitales Públicos , Hospitales Rurales , Internado y Residencia , Área sin Atención Médica , Especialización , Centros Médicos Académicos/estadística & datos numéricos , Selección de Profesión , Competencia Clínica , Educación Médica , Educación de Postgrado en Medicina/estadística & datos numéricos , Etnicidad , Femenino , Encuestas de Atención de la Salud , Humanos , Masculino , Pobreza , Ubicación de la Práctica Profesional , Distribución por Sexo , Factores Socioeconómicos , Estados Unidos
11.
JAMA ; 286(9): 1027-34, 2001 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-11559286

RESUMEN

CONTEXT: Medical educators are seeking improved measures to assess the clinical competency of residents as they complete their graduate medical education. OBJECTIVE: To assess residents' perceptions of their preparedness to provide common clinical services during their last year of graduate medical education. DESIGN, SETTING, AND PARTICIPANTS: A 1998 national survey of residents completing their training in 8 specialties (internal medicine, pediatrics, family practice, obstetrics/gynecology, general surgery, orthopedic surgery, psychiatry, and anesthesiology) at academic health centers in the United States. A total of 2626 residents responded (response rate, 65%). MAIN OUTCOME MEASURES: Residents' reports of their preparedness to perform clinical and nonclinical tasks relevant to their specialties. RESULTS: Residents in all specialties rated themselves as prepared to manage most of the common conditions they would encounter in their clinical career. However, more than 10% of residents in each specialty reported that they felt unprepared to undertake 1 or more tasks relevant to their disciplines, such as caring for patients with human immunodeficiency virus/acquired immunodeficiency syndrome or substance abuse (family practice) or nursing home patients (internal medicine); performance of spinal surgery (orthopedic surgery) or abdominal aortic aneurysm repair (general surgery); and management of chronic pain (anesthesiology). CONCLUSIONS: Overall, residents in their last year of training at academic health centers rate their clinical preparedness as high. However, opportunities for improvement exist in preparing residents for clinical practice.


Asunto(s)
Competencia Clínica , Internado y Residencia , Centros Médicos Académicos , Recolección de Datos , Femenino , Humanos , Masculino , Medicina , Especialización , Estados Unidos
12.
Cell ; 106(2): 183-94, 2001 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-11511346

RESUMEN

The yeast prion [PSI(+)] results from self-propagating aggregates of Sup35p. De novo formation of [PSI(+)] requires an additional non-Mendelian trait, thought to result from a prion form of one or more unknown proteins. We find that the Gln/Asn-rich prion domains of two proteins, New1p and Rnq1p, can control susceptibility to [PSI(+)] induction as well as enhance aggregation of a human glutamine expansion disease protein. [PSI(+)] inducibility results from gain-of-function properties of New1p and Rnq1p aggregates rather than from inactivation of the normal proteins. These studies suggest a molecular basis for the epigenetic control of [PSI(+)] inducibility and may reveal a broader role for this phenomenon in the physiology of protein aggregation.


Asunto(s)
Asparagina/metabolismo , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Glutamina/metabolismo , Priones/química , Priones/metabolismo , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Secuencia de Aminoácidos , Asparagina/química , Asparagina/genética , Ataxina-3 , Proteínas Fúngicas/genética , Expresión Génica , Genes Fúngicos/genética , Glutamina/química , Glutamina/genética , Humanos , Enfermedad de Machado-Joseph/metabolismo , Microscopía Fluorescente , Chaperonas Moleculares/química , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Datos de Secuencia Molecular , Proteínas del Tejido Nervioso/química , Proteínas del Tejido Nervioso/metabolismo , Proteínas Nucleares , Factores de Terminación de Péptidos , Péptidos/química , Péptidos/genética , Péptidos/metabolismo , Fenotipo , Priones/genética , Unión Proteica , Estructura Terciaria de Proteína , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/metabolismo , Proteínas Represoras , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/citología , Saccharomyces cerevisiae/genética
13.
JAMA ; 286(7): 800-6, 2001 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-11497533

RESUMEN

CONTEXT: The changing state of the health care system in the United States may be adversely affecting clinical research conducted in academic health centers (AHCs). Few formal data have been gathered about the nature and extent of the problems facing clinical research or the effects of remedies undertaken by AHCs. OBJECTIVES: To assess the perceived quality and health of the clinical research enterprise and to determine challenges and adaptations to current environmental pressures. DESIGN, SETTING, AND PARTICIPANTS: Mailed survey conducted between December 1998 and March 1999 of a subsample of department chairs and senior research administrators (SRAs) in all US medical schools. Of the 712 potential respondents, 478 completed a questionnaire, yielding an overall response rate of 67.1% (64.8% for SRAs and 67.8% for department chairs). MAIN OUTCOME MEASURES: Ratings of overall health/robustness of clinical research, quality of research in 5 domains, extent of challenges to performing research, and sense of urgency in responding to research challenges; formal strategies for research-related tasks and their effects. RESULTS: Slightly more than half (52%) of all respondents rated the health of the clinical research enterprise as good or excellent compared with 63% for nonclinical research (P<.001). Respondents were most likely to rate nonclinical research as high in quality (79%) compared with 70% for phase 3 clinical trials, 67% for translational research, 65% for phase 1 and 2 trials, and 57% for health services research (for all comparisons with nonclinical research, P<.001). Pressure on clinical faculty to see patients was perceived as a moderate-to-large problem for clinical research by the largest percentage of respondents (93%), followed by insufficient clinical revenues (89%), recruiting trained researchers (75%), lack of external support for clinical research (72%), competition from contract research organizations (48%), problems introduced by the institutional review board process (38%), and finding research participants (37%). In total, 81% of respondents considered the challenges facing clinical research in AHCs to be urgent or extremely urgent. CONCLUSIONS: Academic leaders perceive clinical research activities in AHCs to be less healthy, of poorer quality, and facing greater challenges than nonclinical research activities. Many AHCs do not have policies or mechanisms to address challenges facing the clinical research mission. Even among those with such policies, more than half do not believe these policies have had large positive effects. Our findings support the view that the clinical research workforce and infrastructure may need to be expanded and strengthened to keep pace with advances in basic research.


Asunto(s)
Centros Médicos Académicos/tendencias , Garantía de la Calidad de Atención de Salud , Investigación/tendencias , Centros Médicos Académicos/organización & administración , Centros Médicos Académicos/normas , Humanos , Investigación/organización & administración , Investigación/normas , Estados Unidos
15.
Nature ; 410(6825): 223-7, 2001 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-11242084

RESUMEN

A perplexing feature of prion-based inheritance is that prions composed of the same polypeptide can evoke different phenotypes (such as distribution of brain lesions), even when propagated in genetically identical hosts. The molecular basis of this strain diversity and the relationship between strains and barriers limiting transmission between species remain unclear. We have used the yeast prion phenomenon [PSI+]4 to investigate these issues and examine the role that conformational differences may have in prion strains. We have made a chimaeric fusion between the prion domains of two species (Saccharomyces cerevisae and Candida albicans) of Sup35, the protein responsible for [PSI+]. Here we report that this chimaera forms alternate prion strains in vivo when initiated by transient overexpression of different Sup35 species. Similarly, in vitro the purified chimaera, when seeded with different species of Sup35 fibres, establishes and propagates distinct amyloid conformations. These fibre conformations dictate amyloid seeding specificity: a chimaera seeded by S. cerevisiae fibres efficiently catalyses conversion of S. cerevisiae Sup35 but not of C. albicans Sup35, and vice versa. These and other considerations argue that heritable prion strains result from self-propagating conformational differences within the prion protein itself. Moreover, these conformational differences seem to act in concert with the primary structure to determine a prion's propensity for transmission across a species barrier.


Asunto(s)
Candida albicans/química , Proteínas Fúngicas/química , Priones/química , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/química , Secuencia de Aminoácidos , Amiloide/química , Catálisis , Proteínas Fúngicas/genética , Factores de Terminación de Péptidos , Priones/genética , Conformación Proteica , Proteínas Recombinantes de Fusión/química , Especificidad de la Especie , Relación Estructura-Actividad
16.
Acad Med ; 76(1): 51-9, 2001 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11154197

RESUMEN

PURPOSE: The increase in managed care has led to questions about the inadequacy of instruction undergraduate medical students receive in curricular areas related to managed care. This study examined (1) the percentages of graduating medical students who felt they had received inadequate instruction in six curricular content areas (CCAs): primary care, care of ambulatory patients, health promotion and disease prevention, medical care cost control, teamwork with other health professionals, and cost-effective medical practice; and (2) whether the market competitiveness of these students' medical schools affected their reports of inadequacy of instruction in these CCAs. METHOD: Data from the Association of American Medical Colleges' Graduation Questionnaires (GQs) from 1994 to 1997 were analyzed. The GQ asked graduating students to rate the adequacy of instruction they had received in the six CCAs. Students' ratings were collapsed into the dichotomous variables "inadequate" and "not inadequate." The market competitiveness of medical schools was determined using the four-stage Market Evolution Model developed by the University HealthSystem Consortium. Only responses from students graduating from medical schools that could be staged for all four years of the study were analyzed. Statistical analyses were performed to determine trends for each CCA by year, across the entire study period, by market stage, and by market stage across the entire study period. RESULTS: A total of 39,136 respondents from 86 medical schools were used in the study. The percentages of graduating medical students who reported inadequate instruction decreased over the study period for five of the six CCAs: primary care (27.6% in 1994 to 13.7% in 1997), ambulatory care (37.4% to 23. 9%), medical care cost control (62.9% to 52.9%) cost-effectiveness of medical practice (62.7% to 53.9%), and health promotion and disease prevention (44.4% to 23.7%); all at p <0.001. The responses for inadequacy of instruction for teamwork with other health professionals remained steady from 1994 to 1996 (10.2% to 10.6%), then increased 21.8% in 1997. Over the course of the study, students graduating from schools in more competitive markets (Stage 3 or Stage 4) were more likely to report inadequate instruction in three CCAs, primary care, ambulatory care, and health promotion and disease prevention, than were those graduating from schools in less competitive markets (Stage 1 and Stage 2). Conversely, students graduating from schools in the more competitive health care markets were less likely to report inadequate instruction in cost-effectiveness and cost control than were students from schools in less competitive markets. CONCLUSION: Graduating students' reports of inadequacy of instruction decreased over the study period for five of the six CCAs, increasing only for teamwork with other professionals. Findings were mixed with regard to the relationship of medical schools' market competitiveness and graduating students' reports of inadequacy of instruction. More research is needed to confirm graduating students' perceptions of the inadequacy of their instruction in CCAs related to managed care, particularly once they have gained experience treating patients in managed care environments.


Asunto(s)
Curriculum , Competencia Económica , Programas Controlados de Atención en Salud , Estudiantes de Medicina , Atención Ambulatoria , Control de Costos , Promoción de la Salud , Medicina Preventiva/educación , Atención Primaria de Salud , Encuestas y Cuestionarios , Estados Unidos
17.
19.
Science ; 290(5496): 1571-4, 2000 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-11090354

RESUMEN

The endoplasmic reticulum (ER) supports disulfide bond formation by a poorly understood mechanism requiring protein disulfide isomerase (PDI) and ERO1. In yeast, Ero1p-mediated oxidative folding was shown to depend on cellular flavin adenine dinucleotide (FAD) levels but not on ubiquinone or heme, and Ero1p was shown to be a FAD-binding protein. We reconstituted efficient oxidative folding in vitro using FAD, PDI, and Ero1p. Disulfide formation proceeded by direct delivery of oxidizing equivalents from Ero1p to folding substrates via PDI. This kinetic shuttling of oxidizing equivalents could allow the ER to support rapid disulfide formation while maintaining the ability to reduce and rearrange incorrect disulfide bonds.


Asunto(s)
Retículo Endoplásmico/metabolismo , Flavina-Adenina Dinucleótido/metabolismo , Glicoproteínas/metabolismo , Proteína Disulfuro Isomerasas/metabolismo , Pliegue de Proteína , Proteínas de Saccharomyces cerevisiae , Sitios de Unión , Carboxipeptidasas/química , Carboxipeptidasas/metabolismo , Catepsina A , Fenómenos Químicos , Química Física , Disulfuros/química , Glutatión/metabolismo , Microsomas/metabolismo , Mutación , Oxidación-Reducción , Oxidorreductasas actuantes sobre Donantes de Grupos Sulfuro , Proteína Disulfuro Isomerasas/genética , Ribonucleasa Pancreática/química , Ribonucleasa Pancreática/metabolismo , Saccharomyces cerevisiae/metabolismo
20.
N Engl J Med ; 343(21): 1537-44, 2 p preceding 1537, 2000 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-11087884

RESUMEN

BACKGROUND: Despite abundant evidence of racial disparities in the use of surgical procedures, it is uncertain whether these disparities reflect racial differences in clinical appropriateness or overuse or underuse of inappropriate care. METHODS: We performed a literature review and used an expert panel to develop criteria for determining the appropriateness of renal transplantation for patients with end-stage renal disease. Using data from five states and the District of Columbia on patients who had started to undergo dialysis in 1996 or 1997, we selected a random sample of 1518 patients (age range, 18 to 54 years), stratified according to race and sex. We classified the appropriateness of patients as data on candidates for transplantation and analyzed rates of referral to a transplantation center for evaluation, placement on a waiting list, and receipt of a transplant according to race. RESULTS: Black patients were less likely than white patients to be rated as appropriate candidates for transplantation according to appropriateness criteria based on expert opinion (71 blacks [9.0 percent] vs. 152 whites [20.9 percent]) and were more likely to have had incomplete evaluations (368 [46.5 percent] vs. 282 [38.8 percent], P<0.001 for the overall chi-square). Among patients considered to be appropriate candidates for transplantation, blacks were less likely than whites to be referred for evaluation, according to the chart review (90.1 percent vs. 98.0 percent, P=0.008), to be placed on a waiting list (71.0 percent vs. 86.7 percent, P=0.007), or to undergo transplantation (16.9 percent vs. 52.0 percent, P<0.001). Among patients classified as inappropriate candidates, whites were more likely than blacks to be referred for evaluation (57.8 percent vs. 38.4 percent), to be placed on a waiting list (30.9 percent vs. 17.4 percent), and to undergo transplantation (10.3 percent vs. 2.2 percent, P<0.001 for all three comparisons). CONCLUSIONS: Racial disparities in rates of renal transplantation stem from differences in clinical characteristics that affect appropriateness as well as from underuse of transplantation among blacks and overuse among whites. Reducing racial disparities will require efforts to distinguish their specific causes and the development of interventions tailored to address them.


Asunto(s)
Negro o Afroamericano/estadística & datos numéricos , Accesibilidad a los Servicios de Salud/estadística & datos numéricos , Fallo Renal Crónico/etnología , Trasplante de Riñón/estadística & datos numéricos , Adulto , Población Negra , Femenino , Humanos , Fallo Renal Crónico/cirugía , Fallo Renal Crónico/terapia , Masculino , Selección de Paciente , Derivación y Consulta , Diálisis Renal , Factores Socioeconómicos , Estados Unidos , Población Blanca
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...