Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
2.
J Surg Res ; 107(1): 145-53, 2002 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12384078

RESUMEN

Enteral nutrition with eicosapentaenoic acid (EPA; 20:5 n-3) and gamma-linolenic acid (GLA; 18:3 n-6) decreased pulmonary inflammation by reducing neutrophil counts and chemotactic factors in bronchoalveolar lavage fluid during acute respiratory distress syndrome (ARDS). We hypothesize that the anti-inflammatory effects of EPA and GLA may be due, in part, to induction of neutrophil apoptosis. The purpose of this study was to determine whether EPA and GLA, alone or in combination, trigger apoptotic cell death in the human promyelocytic leukemia HL-60 cell line. HL-60 cells were incubated with 10, 20, 50, and 100 micromol/L EPA, GLA, or various combinations of EPA and GLA for 2, 4, 8, 12, and 24 hs. Oleic acid (18:1 n-9) was used as a fatty acid control. Flow cytometry using dual staining with propidium iodide and annexin V-FITC assessed apoptosis, necrosis, and viability. Apoptosis was verified by DNA fragmentation as assessed by agarose gel electrophoresis. EPA, GLA, and various combinations of EPA and GLA significantly induced apoptosis and reduced cell viability in HL-60 cells. Viability was significantly reduced to the same extent with the combination of 50 micromol/L EPA\20 micromol/L GLA compared with 100 micromol/L EPA. These data indicate that EPA and GLA, alone or in combination, reduce cell survival by induction of apoptosis. Thus, induction of apoptosis by select dietary n-3 (EPA) and n-6 (GLA) polyunsaturated fatty acids may be the mechanism of the resolution of pulmonary inflammation in ARDS.


Asunto(s)
Apoptosis/efectos de los fármacos , Ácido Eicosapentaenoico/farmacología , Células HL-60/efectos de los fármacos , Células HL-60/fisiología , Ácido gammalinolénico/farmacología , Supervivencia Celular/efectos de los fármacos , Fragmentación del ADN/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Combinación de Medicamentos , Ácido Eicosapentaenoico/administración & dosificación , Citometría de Flujo , Humanos , Ácido gammalinolénico/administración & dosificación
3.
Am Surg ; 67(11): 1017-21, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11730216

RESUMEN

The frequency of computed tomography (CT) ordered by emergency department physicians at our facility was noted to sharply increase in early 1998 after a New England Journal of Medicine (NEJM) article recommending routine CT in patients with suspected appendicitis. Numerous studies have proven the accuracy of CT for detecting acute appendicitis; however, the most appropriate use of CT continues to evolve. We sought to evaluate the effect of increased CT use on negative appendectomy rate and perforation rate at our institution and to better delineate in whom CT is most beneficial. CT use was retrospectively evaluated and found to sharply increase in April 1998. The authors then reviewed the medical records of 291 consecutive patients undergoing appendectomy 18 months before and after the NEJM article. Patients with interval appendectomies and those 12 years of age or younger were excluded. The remaining 226 patients constitute the study cohort. The study cohort was then divided into the two groups. The "Discriminate Group" consists of patients from the 18 months before the NEJM article impact and a period of selective CT use. The "Indiscriminate Group" comprises patients from the subsequent 18 months in which CT use was substantially higher and routinely obtained before surgical evaluation. After chart review an objective clinical score (Alvarado score) was assigned to each patient. Comparison was then made between the two groups on perforation rate, negative appendectomy rate, time delay to operating room, and Alvarado score. Additionally patients undergoing preoperative CT were compared with those without CT. These groups were also evaluated on the basis of negative appendectomy rate, perforation rate, and delay to the operating room. CT in patients with abdominal symptoms associated with appendicitis increased from 188 in the Discriminate Group to 1035 in the Indiscriminate Group. In the Discriminate Group the negative appendectomy rate was 15.1 per cent. After the indiscriminate use of CT the negative appendectomy rate decreased to 13.3 per cent, but this was not significant. Males experienced a decrease in the negative appendectomy rate from 10.1 to 6.9 per cent, whereas the rate for females increased slightly from 21.3 to 22.9 per cent. Again we found no statistical significance in these changes. The overall perforation rate of 17.9 per cent in the first 18 months decreased to 13.3 per cent in the following 18 months but again was not statistically significant. The Alvarado scores between the Discriminate and Indiscriminate groups were 6.7 and 7.3, respectively (P = 0.02). Patients with preoperative CT averaged 11.9 hours to the operating room compared with 6.5 hours for those without CT (P = 0.03). Use of CT did not decrease perforation rate but did globally reduce negative exploration (P = 0.05). This reduction in negative exploration however was not discriminated by sex. CT use in suspected acute appendicitis has greatly increased over the past several years. The dramatic increase in CT use at our institution has not resulted in dramatic decreases in negative appendectomy rate or statistically significant changes in perforation rate. The optimal use of CT in evaluating patients with suspected appendicitis has yet to be determined. Surgical consultation should be obtained early to avoid indiscriminate tests.


Asunto(s)
Apendicectomía , Apendicitis/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Apendicitis/complicaciones , Femenino , Humanos , Perforación Intestinal/diagnóstico por imagen , Perforación Intestinal/etiología , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Retrospectivos
4.
Am Surg ; 67(11): 1110-2, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11730232

RESUMEN

We assessed the effect of blood alcohol concentration (BAC) on the evaluation, outcome, and hospital charges of our observation-status trauma patient population. We conducted a retrospective study over 18 months; any patient initially admitted with <24-hour observation status, Glasgow Coma Score of 15, and negative drug screen was eligible. Patients were divided on the basis of BAC (BAC+ = >80 mg/dL; BAC- = <80 mg/dL). Two hundred twenty-six patients were observed during the study (2765 admissions). For the 66 BAC+ patients (range 90-392 mg/dL) there was a strong male predominance. There was no difference in diagnostic evaluation schema, delayed diagnosis, complications, cost, or conversions to full admission between the groups. We conclude that evaluation, outcome, and charges of observation trauma patients are the same regardless of BAC. Intoxication did not mask injury; therefore BAC+ patients do not require observation on the sole basis of intoxication if their evaluation is otherwise negative.


Asunto(s)
Intoxicación Alcohólica , Servicio de Urgencia en Hospital , Evaluación de Resultado en la Atención de Salud , Heridas y Lesiones , Adulto , Intoxicación Alcohólica/complicaciones , Femenino , Humanos , Masculino , Observación , Estudios Retrospectivos , Tennessee , Heridas y Lesiones/diagnóstico , Heridas y Lesiones/terapia
5.
J Trauma ; 51(4): 648-51, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11586153

RESUMEN

BACKGROUND: The differentiation of duodenal perforation from duodenal hematoma is not always possible with computed tomography (CT). Our diagnostic guideline has included duodenography to investigate CT findings of periduodenal fluid or wall thickening. However, the utility of duodenography as a diagnostic study in blunt abdominal trauma is not defined. We evaluated duodenography as a diagnostic test in patients with suspected blunt duodenal injuries (BDIs). METHODS: During a 10-year period, 96 patients out of 25,608 trauma admissions had CT findings of possible BDI and underwent duodenography. Demographic and clinical data, diagnostic methods, and management were derived from prospectively collected data. CT and duodenography studies were reviewed and correlated with surgical findings and outcome. All CT scans were obtained with intravenous contrast; oral contrast was used in 32 patients. Duodenography was analyzed using the 2 x 2 method and Bayes theorem. RESULTS: Indications for duodenography included periduodenal fluid without extravasation (76%), abnormal duodenal wall thickening (16%), and retroperitoneal extraluminal gas (5%). Eighty-six duodenography studies were reported as normal, six were consistent with hematoma, one was indeterminate, and only three revealed extravasation. Two of these three patients with duodenal perforation had retroperitoneal extraluminal air. Only one patient underwent exploration on the basis of duodenography. No blunt duodenal perforation was diagnosed by CT. Overall, duodenography had sensitivity of 54% and specificity of 98%. For BDIs requiring repair, duodenography sensitivity was only 25%; the false-negative rate was also 25%. Retroperitoneal extraluminal air was a useful sign of duodenal perforation, occurring in two of three patients with BDI and only in one without BDI (p < 0.001). CONCLUSION: Duodenography has a low sensitivity in patients with suspected BDI by CT findings and is of minimal utility in diagnostic evaluation. Retroperitoneal extraluminal air seen on CT is an important sign of BDI requiring surgical repair.


Asunto(s)
Duodeno/lesiones , Radiografía Abdominal , Tomografía Computarizada por Rayos X , Heridas no Penetrantes/diagnóstico por imagen , Adolescente , Adulto , Anciano , Teorema de Bayes , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad
6.
J Trauma ; 50(5): 835-42, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11371838

RESUMEN

BACKGROUND: For patients > 55 years, nonoperative management (NOM) of blunt splenic injury remains controversial. Conflicting reports of excessively high or acceptably low failure rates have discouraged widespread application of NOM in these older patients. However, the small number of patients in these studies limits the impact of their conclusions. METHODS: We manage splenic injury nonoperatively in all appropriate patients without regard to age. We present the largest series of patients > 55 years who have been managed nonsurgically, in a retrospective review of all patients with blunt splenic injury admitted to our trauma center between 1996 and 1999. RESULTS: In 4 years, 542 patients were admitted with blunt splenic injury. Eighty-three patients were > 55 years, and 61 of these patients underwent NOM. Seven older patients failed NOM and required delayed splenectomy, yielding a failure rate of 11.4%. This failure rate was statistically equivalent to the 7% failure rate of patients < 55 years. This study has a power of 80% to detect a failure rate change from 7% to 20%. By multivariate analysis, the only factor that significantly increased the risk of NOM failure was splenic injury grade. Patients > 55 years had a higher mortality than younger patients regardless of NOM/operative treatment. Splenic injury did not directly cause any of the deaths in patients > 55 years who had NOM or failure of NOM. High-grade splenic injuries fail NOM in those > 55 years. CONCLUSION: Nonoperative management of lower grade splenic injuries in patients > 55 years can be accomplished with an acceptably low failure rate. Only grade of splenic injury, not patient age, increases the risk of NOM failure.


Asunto(s)
Bazo/lesiones , Heridas no Penetrantes/terapia , Adulto , Anciano , Anciano de 80 o más Años , Humanos , Tiempo de Internación , Modelos Logísticos , Persona de Mediana Edad , Estudios Retrospectivos , Heridas no Penetrantes/mortalidad
7.
Holist Nurs Pract ; 16(1): 43-54, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-15559046

RESUMEN

In this study, a qualitative interpretivist perspective was used to analyze the following research question: How does clinical nursing practice facilitate learning? Forty nurses working in acute care, long-term care, and home care were interviewed about their clinical practice experiences and the learning that resulted. Data were analyzed using a constant comparative method. Study results indicate that clinical nursing practice facilitates both personal and professional development of nurses by fostering an examination of the concepts of self-respect, hope, control, vulnerability, acceptance, loss, and persistence. Implications for continuing educators and staff development instructors are drawn.


Asunto(s)
Competencia Clínica/normas , Educación Continua en Enfermería , Aprendizaje , Rol de la Enfermera , Personal de Enfermería/educación , Adulto , Anécdotas como Asunto , Educación Continua en Enfermería/métodos , Humanos , Satisfacción en el Trabajo , Persona de Mediana Edad , Investigación en Educación de Enfermería , Personal de Enfermería/psicología , Autonomía Profesional , Desarrollo de Personal/métodos , Factores de Tiempo
8.
J Trauma ; 48(4): 684-8, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10780602

RESUMEN

BACKGROUND: Efficacy of chest radiograph protocol after tube thoracostomy tube (CT) removal. METHODS: Retrospective review (July of 1995 to July of 1996) of 141 patients with CT followed throughout their hospitalization. Excluded patients died (23 patients) or had thoracotomy (13 patients) before CT removal. RESULTS: A total of 105 patients had 113 CT removed (mean age, 36.9 years; Injury Severity Score = 23.4; CT duration, 5.0 days). Protocol chest radiographs were performed on average at 7.9 and 22.1 hours. Recurrent pneumothorax (RHPTX = new interpleural air) occurring in 12 patients (11%) and persistent pneumothorax (PHPTX = same volume of interpleural air) occurring in 13 patients (12%) caused no clinical problems and were treated without tube replacement. Three patients had symptoms after removal; none had RHPTX. Two patients had clinical signs; one reaccumulated a hemothorax requiring CT replacement, the other improved without replacement. CONCLUSIONS: Clinically significant RHPTX/PHPTX after CT removal is infrequent. Signs not symptoms detect CT removal complications. At our institution, chest radiographs are obtained in a delayed manner from protocol and offer no benefit over clinical assessment.


Asunto(s)
Pruebas Diagnósticas de Rutina , Intubación , Radiografía Torácica , Traumatismos Torácicos/terapia , Toracostomía , Adolescente , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neumotórax/diagnóstico por imagen , Recurrencia , Estudios Retrospectivos , Índices de Gravedad del Trauma
9.
J Nurs Educ ; 38(1): 42-7, 1999 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9921788

RESUMEN

The purpose of this article is to describe a study that implemented concept maps as a methodology to teach and evaluate critical thinking. Students in six senior clinical groups were taught to use concept maps. Students created three concept maps over the course of the semester. Data analysis demonstrated a group mean score of 40.38 on the first concept map and 135.55 on the final concept map, for a difference of 98.16. The paired t value comparing the first concept map to the final concept map was -5.69. The data indicated a statistically significant difference between the first and final maps. This difference is indicative of the students' increase in conceptual and critical thinking.


Asunto(s)
Formación de Concepto , Investigación en Educación de Enfermería , Aprendizaje Basado en Problemas , Pensamiento , Logro , Curriculum , Bachillerato en Enfermería , Humanos , Estados Unidos
10.
J Gerontol Nurs ; 25(11): 19-25, 1999 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-10776158

RESUMEN

Dying is a central experience in the life of a family. Yet there are few studies of dying in long-term care and the role of a family. The dynamic relationships among families, staff, and residents in long-term care facilities related to the process of dying is an area where research is needed. As part of a larger study of death and dying in long-term care settings, 11 family members who recently had experienced the loss of a relative in the long-term care setting were interviewed. The purpose of this study was to describe family perspectives on death and dying in long-term care facilities and to discuss ways staff may be helpful to families in coping with the loss of a family member. Analyzing death and dying from the family perspective offers health care providers an opportunity to expand the understanding of the phenomenon of death in long-term care facilities and to incorporate care activities that families view as helpful. Major themes emerged from this study, including the caring behaviors of staff, participating in the dying process, and providing spiritual support. The themes and practice implications are discussed in this article.


Asunto(s)
Actitud Frente a la Muerte , Actitud Frente a la Salud , Familia/psicología , Cuidados a Largo Plazo/psicología , Cuidado Terminal/psicología , Adaptación Psicológica , Anciano , Empatía , Humanos , Investigación Metodológica en Enfermería , Cuidado Pastoral , Relaciones Profesional-Familia , Instituciones de Cuidados Especializados de Enfermería , Apoyo Social
11.
J Contin Educ Nurs ; 30(5): 213-8; quiz 238-9, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10808837

RESUMEN

The purpose of this article is to describe and analyze a reciprocal partnership developed among four university-based continuing education providers in Wisconsin. Members of this partnership collaborated in developing a statewide program to address the educational needs of nurses moving from acute or long-term care into community nursing. Components of the reciprocal partnership model were applied in developing this program. The partners identified that, despite the initial time investment, the collaborative approach was an advantage. The collaborative approach enhanced the quality of the program developed and reached a wider audience. Continuing nursing educators may want to consider partnership arrangements for program development and implementation.


Asunto(s)
Enfermería en Salud Comunitaria/educación , Conducta Cooperativa , Educación Continua en Enfermería/organización & administración , Relaciones Interinstitucionales , Personal de Enfermería en Hospital/educación , Universidades/organización & administración , Humanos , Modelos Organizacionales , Evaluación de Necesidades , Técnicas de Planificación , Desarrollo de Programa , Wisconsin
12.
J Palliat Med ; 1(1): 21-34, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-15859869

RESUMEN

Death occurs among older adults in institutions more often than at home with family and friends. The older people are, the more likely they are to die in a nursing home. The purpose of this study was to describe staff and administrator's perspectives on death and dying in long-term care and to explore problems in providing humane care to dying residents that fosters gentle closure to life. Using focus group interviews as the primary data collection method, 22 focus group sessions were conducted in 11 nursing homes. Separate group sessions were held for staff and administrators in the nursing homes. The core variable identified in this study was the attachment of staff to residents in long term care. Attachment enhanced the quality of terminal care and fostered a gentle closure to life. Mediating forces influencing the process of attachment were identified as individual forces, as well as forces internal and external to the nursing home.

13.
J Contin Educ Nurs ; 28(3): 102-14, 1997.
Artículo en Inglés | MEDLINE | ID: mdl-9165789

RESUMEN

This qualitative interpretivist study analyzed the interrelationships between the knowledge gained through continuing nursing education programs and the context of nurses' clinical practice. The content of nursing continuing education programs offered 9-12 months previously was reviewed. Forty semi-structured, tape-recorded interviews were conducted with nurses from hospitals, nursing homes and home care agencies to determine their use of this new knowledge. Findings indicate that nurses used information from continuing education programs to construct a knowledge base and that this process was affected by the structural, human resources, political and symbolic frames of the context in which nurses practice.


Asunto(s)
Actitud del Personal de Salud , Competencia Clínica , Educación Continua en Enfermería/normas , Conocimiento , Personal de Enfermería/educación , Personal de Enfermería/psicología , Humanos , Modelos de Enfermería , Investigación en Educación de Enfermería , Investigación Metodológica en Enfermería , Proceso de Enfermería , Encuestas y Cuestionarios
14.
Chest ; 110(6): 1577-80, 1996 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8989080

RESUMEN

STUDY OBJECTIVE: Determine reintubation rate, identify its cause, and detail adverse outcomes from reintubation. DESIGN: Retrospective review of extubation failures in the trauma ICU. SETTING: University hospital and regional trauma center. PATIENTS: Four hundred five patients arriving intubated or requiring intubation during hospitalization after 2,516 traumatic injury admissions over 18 months. INTERVENTIONS: None. RESULTS: Reintubation incidence was 7% (27 times per 405 patients). Comparative mortality of the reintubated group (2/24 = 8%) is similar to overall trauma center mortality (224/2516 = 6.5%), but less than the cohort of patients admitted to the hospital intubated (63/405 = 16%). Reintubated patients had an increased frequency of stridor than reported previously (33%), and an increased tracheostomy rate (62% vs 30%). Stridor was not predictable from injury severity score, Glasgow coma score, age, sex, length of intubation, or place of intubation. Pulmonary complications (atelectasis, tracheobronchitis, pneumonia) developed in half of reintubated patients; stridorous patients did not have an increased rate of pulmonary complications. CONCLUSION: Reintubation in trauma ICU patients does not predict poor outcome.


Asunto(s)
Intubación Intratraqueal , Heridas y Lesiones/terapia , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Unidades de Cuidados Intensivos , Intubación Intratraqueal/efectos adversos , Masculino , Persona de Mediana Edad , Respiración Artificial/efectos adversos , Ruidos Respiratorios/etiología , Estudios Retrospectivos , Resultado del Tratamiento , Heridas y Lesiones/mortalidad
15.
J Contin Educ Nurs ; 27(5): 228-37, 1996.
Artículo en Inglés | MEDLINE | ID: mdl-9025412

RESUMEN

The purpose of this qualitative interpretivist study was to analyze and articulate the characteristics of nursing practice in the home health care context. Researchers sought to describe expert home health care nursing practice and how it developed. Twenty-one nurses, at various stages of practice development, were asked to write three clinical narratives describing their home health care practice. Data were analyzed to elicit themes and characteristics of nursing practice in the home health care context. Findings indicate that in the context of home health care, expert nursing practice develops along a continuum, until nurses can integrate physiological data with environmental and family data to provide seamless, intuitive, and highly complex nursing care. The results of this research can assist continuing education and staff development providers as they develop educational programs designed to facilitate professional development of new graduates and newly employed nurses in home health care.


Asunto(s)
Enfermería en Salud Comunitaria/educación , Enfermería en Salud Comunitaria/métodos , Educación Continua en Enfermería/organización & administración , Servicios de Atención de Salud a Domicilio , Perfil Laboral , Humanos , Investigación Metodológica en Enfermería , Escritura
16.
Sportverletz Sportschaden ; 10(2): 27-31, 1996 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-8795134

RESUMEN

The cruciate ligaments contain mechanoreceptors which putatively contribute to knee function and dysfunction. However, the interpretation of studies showing neural responses to traction loads applied to the cat cranial cruciate ligament (CCL analogous to the anterior cruciate ligament in humans) depends upon demonstrating that non-CCL periarticular receptors are not stimulated. We assessed the capability to rigidly fix the knee against traction loads applied to the feline CCL. The tibia and femur were fixed either with clamps or Steinmann pins. Motion of the bones was monitored with liquid metal strain gages (LMSG) and the activity of the posterior articular nerve (PAN) was recorded while traction loads of up to 20-30 N were applied to the CCL. Joint afferents recorded from the PAN were insensitive to the CCL loads in the rigidly fixed preparation. Motion of the proximal tibia and distal femur was less than 100 micrometers for both methods of fixation, with neither method demonstrating more rigid fixation. In contrast, we observed vigorous discharges with focused light pressure on the capsule and under conditions allowing 200-500 micrometers of tibial displacement on the femur. This suggests that clinically undetectable instability may give rise to aberrant mechanoreceptor activity contributing to dysfunction.


Asunto(s)
Ligamento Cruzado Anterior/inervación , Articulación de la Rodilla/inervación , Mecanorreceptores/fisiología , Propiocepción/fisiología , Rango del Movimiento Articular/fisiología , Vías Aferentes/fisiología , Animales , Fenómenos Biomecánicos , Gatos , Femenino , Masculino , Nervio Tibial/fisiología
17.
J Contin Educ Nurs ; 27(1): 17-27, 1996.
Artículo en Inglés | MEDLINE | ID: mdl-8576492

RESUMEN

The purpose of this article is to offer a different methodology for teaching and learning in continuing nursing education and staff development. This article describes a qualitative research study that analyzed how linkages are made between theoretical material and clinical nursing practice. Findings indicate that nursing students did not link the elements of nursing process together, that clinical preparation was not linked to theoretical material, that the meaning students made of the information was different than the instructors' and that concepts from the basic sciences were not incorporated into student meaning structures. Implications for the use of concept maps as an educational strategy in continuing nursing education are drawn.


Asunto(s)
Graduación en Auxiliar de Enfermería/métodos , Atención de Enfermería/métodos , Teoría de Enfermería , Adulto , Femenino , Humanos , Aprendizaje , Persona de Mediana Edad , Investigación en Educación de Enfermería , Investigación Metodológica en Enfermería , Estudiantes de Enfermería/psicología
18.
Iowa Orthop J ; 15: 168-73, 1995.
Artículo en Inglés | MEDLINE | ID: mdl-7634028

RESUMEN

The cruciate ligaments contain mechanoreceptors which putatively contribute to knee function and dysfunction. However, the interpretation of studies showing neural responses to traction loads applied to the cat cranial cruciate ligament (CCL-analogous to the anterior cruciate ligament in humans) depends upon demonstrating that non-CCL periarticular receptors are not stimulated. We assessed the capability to rigidly fix the knee against traction loads applied to the feline CCL. The tibia and femur were fixed either with clamps or Steinmann pins. Motion of the bones was monitored with liquid metal strain gauges (LMSG) and the activity of the posterior articular nerve (PAN) was recorded while traction loads of up to 20-30 N were applied to the CCL. Joint afferents recorded from the PAN were insensitive to the CCL loads in the rigidly fixed preparation. Motion of the proximal tibia and distal femur was less than 100 micrometers for both methods of fixation, with neither method demonstrating more rigid fixation. In contrast, we observed vigorous discharges with focused light pressure on the capsule and under conditions allowing 200-500 micrometers of tibial displacement on the femur. This suggests that clinically undetectable instability may give rise to aberrant mechanoreceptor activity contributing to dysfunction.


Asunto(s)
Vías Aferentes/fisiología , Ligamento Cruzado Anterior/fisiología , Articulación de la Rodilla/fisiología , Mecanorreceptores , Animales , Fenómenos Biomecánicos , Gatos , Femenino , Masculino , Movimiento/fisiología , Rotación
19.
Nutrition ; 10(2): 128-31, 1994.
Artículo en Inglés | MEDLINE | ID: mdl-8025365

RESUMEN

A midarm muscle circumference (AMC) < 10th percentile indicates severe protein-energy malnutrition. We identified 20 consecutive patients receiving specialized nutritional therapy from the Nutrition Support Service of the New England Deaconess Hospital during a 3-mo period who had AMC < 10th percentile and 24-h urine and serum creatinine determinations performed. Mean weight was 96 +/- 25% of ideal body weight (IBW), with only 7 patients < 85% IBW, reaffirming that weight is often insensitive for the identification of lean tissue loss. Twenty-four-hour urine creatinine excretion confirmed most to be severely lean body mass depleted (creatinine-height index < 60% in 17 subjects) as predicted by AMC. Sixteen patients had normal kidney function as assessed by serum creatinine levels and hospital norms (0.3-1.2 mg/dl). However, abnormal creatinine clearances were found in 15 of 20 subjects (normal 80-100 ml/min), with a mean value (53 +/- 23 ml/min) also below normal. These results suggest that the usual normal range for serum creatinine, based on well-nourished patients, should be adjusted in severely malnourished patients. Considering the upper limit of normal serum creatinine in this population to be 0.7 mg/dl, to reflect the approximately 60% reduction in lean tissue indicated by an AMC < or = 10th percentile, would identify all but 1 patient with an abnormal creatinine clearance (sensitivity 93%, specificity 67%). Use of a predictive formula (the Cockcroft-Gault equation) also identified those with kidney dysfunction but overestimated actual function to a level not usually requiring drug dose adjustment and did not obviate the need for further testing.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Antropometría , Brazo , Creatinina/sangre , Riñón/fisiopatología , Músculos , Desnutrición Proteico-Calórica/fisiopatología , Adulto , Anciano , Anciano de 80 o más Años , Peso Corporal , Femenino , Humanos , Masculino , Tasa de Depuración Metabólica , Persona de Mediana Edad
20.
J Biomech Eng ; 115(2): 131-6, 1993 May.
Artículo en Inglés | MEDLINE | ID: mdl-8326718

RESUMEN

Six major mechanical design variables characterizing single-upright lateral prophylactic knee braces were studied experimentally, using a generic modular brace (GMB). Impulsive valgus loading tests were conducted with the GMB applied to a surrogate leg model. The surrogate involved anatomically realistic aluminum-reinforced acrylic components to model bone, and expendable polymeric blanks to mimic the major knee ligaments. Behavior of the surrogate system reasonably reproduced that of human cadaveric knees under similar loading conditions. Load at failure of the medial collateral ligament (MCL) analog, gross knee stiffness, and MCL relative strain relief were measured for each of twelve parametric brace design permutations. Compared to the unbraced condition, bracing provided statistically significant increases in valgus load uptake at failure and in MCL strain relief. Increasing the dimensions of individual brace components (hinge length and offset; upright length, breadth, and thickness; cuff area), relative to those of a GMB baseline configuration deemed representative of current commercial products, failed to achieve statistically significant improvements in brace performance. However, most below-baseline dimensioning of individual components did significantly compromise GMB performance. These surrogate test data indicate that geometric modifications of current single-upright lateral brace designs are unlikely to substantially improve upon the fairly modest valgus load protection afforded by this class of devices.


Asunto(s)
Tirantes/normas , Fútbol Americano/lesiones , Traumatismos de la Rodilla/prevención & control , Fenómenos Biomecánicos , Diseño de Equipo , Falla de Equipo , Humanos , Traumatismos de la Rodilla/etiología , Traumatismos de la Rodilla/fisiopatología , Ensayo de Materiales , Modelos Anatómicos , Rango del Movimiento Articular , Soporte de Peso
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA