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Biomedical subjects

S Greenfield

Publications and source records attributed to S Greenfield.

At least 127 records · Page 7Linked to original sources
PubMed1983

Reverse consultations: the profiles of patients referred from subspecialists to generalists.

To determine the characteristics of patients referred by subspecialists to generalists, we compared 67 patients referred by three medical subspecialty clinics to the general internal medicine clinic to 162 randomly chosen patients who were retained by those clinics, with respect to the patients' need for a broad array of services. A trained abstractor reviewed the records for the prior year for patient characteristics indicating a need for broad-based care. The mean referred patient age was 53.7 yr compared to 46.2 yr in the retained group (p = 0.001); 33% of referred patients, as compared to 20% of those retained, had references to psychosocial problems in the physician notes (p = 0.03). Referred patients had 2.34 diagnoses outside of the subspecialty, compared to 1.27 for retained patients (p = 0.001). Referred patients had more recorded complaints outside of the subspecialty, 1.18 vs 0.71, (p = 0.02). Referred patients also had significantly more total clinic visits and visited twice as many different types of clinics in the past year (p = 0.001). There were no differences in payment method or insurance status. These findings suggest that university based subspecialists prefer to refer medically and psychosocially complex patients. If it is desirable that subspecialists value such patients more highly, changes in subspecialty training programs might be needed. If not, more generalists may be needed to care for such patients.

Adult↗
PubMed1983

Activity of a kidney epithelial cell growth inhibitor on lung and mammary cells.

A kidney epithelial cell growth inhibitor, isolated from BSC-1 cell-conditioned medium, has been found to be active on certain lung and mammary gland cell lines in culture. The most responsive cell observed thus far is the CCL64 mink lung cell line. With CCL64 cells, 60% inhibition of [3H]thymidine incorporation is observed at a 0.1 nanogram/ml concentration of the growth inhibitor, and approximately 95% inhibition at 1 nanogram/ml. A human mammary tumor cell line, Hs578T, shows 75% inhibition of [3H]thymidine incorporation, in cell culture. Preliminary studies indicate that injection of the kidney epithelial cell growth inhibitor in vivo into human mammary carcinomas growing in nude mice inhibits [3H]thymidine incorporation in the tumors.

Animals↗
PubMed1983

Clinical trial of an emergency resuscitation algorithm.

Clinical trials of a resuscitation algorithm for patients entering the Surgical Emergency Department (ED) with acute hypotension were conducted for a 30-month period. The intent was not to compare good management with bad, but rather university-run county hospital services with and without an algorithm. The study group was comprised of 603 hypotensive patients out of 6833 consecutive admissions. The effects of the policy of using a resuscitation algorithm were evaluated by the outcomes of the patients who were treated by residents given the algorithm (protocol group) versus those treated by residents not given the algorithm (control group). The efficacy of the algorithm, per se, was evaluated by outcomes of patients whose management was in satisfactory compliance with the algorithm as compared with those whose management deviated from the algorithm. The patients were also evaluated by the primary cause of their hypotension and the presence of severe associated illnesses. Outcomes of patients treated by residents given the algorithm were as good and in a number of respects better than those of patients treated by residents without the algorithm. The mean resuscitation time of the protocol group was markedly and significantly less than that of the control group indicating that the policy of using the algorithm facilitated resuscitation even though it was not always properly followed. Patients with trauma, hemorrhage, and sepsis, whose care was in satisfactory compliance with the algorithm had shorter resuscitation times, lower MAP-time deficits, and less shock-related complications. The algorithm which is primarily directed toward fluid resuscitation did not appear to be efficacious for patients whose trauma was primarily head injury, where fluid restriction may be the therapy of choice.

Adolescent↗
PubMed1983

Protein composition of PNS myelin: developmental comparison of control and quaking mice.

Protein compositions were determined for sciatic nerve myelin isolated from young and adult control and quaking (Qk) mice. Age-related changes in the relative amounts of large (Pl) and small (Pr) basic proteins were found. In control animals, the ratio Pr/Pl increased with age, a change similar to that observed for the large (Bl) and small (Bs) CNS myelin basic proteins of adult mice. Pr/Pl also increased with age in the Qk mouse sciatic nerve, but only to the point that the value in the adult Qk mouse was similar to that observed for young control animals, a situation reminiscent of the effect of the Qk mutation on CNS basic proteins. Thus, our data suggest that the Qk mutation has a similar effect on peripheral nervous system (PNS) and CNS basic proteins. Our findings are consistent with recent electrophoretic and immunochemical data showing that PNS and CNS myelin basic proteins in rodents are analogous, and they suggest that the genetic program controlling basic protein expression is common to oligodendroglia and Schwann cells.

Aging↗
PubMed1983

Studies on subcellular fractions which are involved in myelin assembly: labeling of myelin proteins by a double radioisotope approach indicates developmental relationships.

The question of developmental relationships amongst myelin-related membranes in subfractions of myelinating mouse brain (15 days) was investigated by a time-staggered double isotope protocol using [3H]leucine and [14C]leucine. Preliminary results are interpreted and discussed in the context of a mathematical conceptualization of pulse-labeling kinetic analyses of myelin proteins in subcellular membrane compartments. Differences in ratio of the two leucine labels among proteins of myelin-containing subfractions are interpreted as confirming metabolic differences relating to various stages of development rather than precursor-product relationships. The incorporation into myelin of 14K, 17K, and 18.5K basic proteins (MBPs) occurs with relatively short delay times, following their synthesis (less than 5 min), and seems to occur simultaneously into all compartments. The 21.5K MBP and the proteolipid protein, on the other hand, require 10-14 min and 14-20 min, respectively. A scheme is presented to illustrate the probable assignment of subfractions to various myelin "compartments" during myelination, and to serve as a working hypothesis for studies on precursor-product relationships.

Animals↗
PubMed1983

The survival benefit of bystander cardiopulmonary resuscitation in a paramedic served metropolitan area.

We investigated the survival benefit bystander cardiopulmonary resuscitation (CPR) for out-of-hospital emergencies in a paramedic served area of metropolitan Los Angeles. Clinical information for all events occurring between January 1 and December 31, 1978 was obtained from paramedic report forms and hospital medical records. Bystander CPR was performed for 93 cases and, of these, 20 (22 per cent) survived to hospital discharge, as compared to 7 (5 per cent) of the 150 patients not receiving bystander CPR (p less than 0.001). Twelve (27 per cent) of the 45 patients in ventricular fibrillation (VF) who had bystander CPR survived, as compared to 4 (6 per cent) of 70 VF patients without bystander CPR (p less than 0.01). We conclude that bystander CPR, initiated prior to arrival of paramedics, produced a fourfold improvement in survival. Overall there was a 10 per cent survival rate at hospital discharge. Survival rates reported from Seattle may not necessarily be generalized to larger cities.

Aged↗
PubMed1983

Biases in the laboratory diagnosis of depression in medical practice.

Several studies, conducted in psychiatric settings, have reported that the dexamethasone suppression test (ST) is useful in the diagnosis of endogenous depression. To determine whether the test has clinical utility in internal medicine practice, data were reviewed and reanalyzed from all studies that evaluated the dexamethasone ST in the diagnosis of depression. In these 11 studies, the mean positive predictive value reported for the test was 84%, reflecting high prevalence of disease (50%), sensitivity (43%), and specificity (92%) in those specialized populations studied. When estimates of the prevalence and severity of conditions associated with depressed mood seen in internal medicine were used, the sensitivity dropped to 30%, and the specificity to 85%. Assuming a prevalence of 20%, a figure based on available epidemiologic data, the predictive value for a positive test would be 33%, too low to have value in most clinical settings. Data from studies currently available do not support the use of dexamethasone ST in internal medicine practice. More generally, before any test is adopted in a general medical setting, it should be studied in that setting, or available data should be reanalyzed to correct for biases affecting prevalence, sensitivity, and specificity that may inflate the test's value.

Clinical Laboratory Techniques↗
PubMed1982

Patient suffering and patient satisfaction among the chronically ill.

In a patient population with serious, debilitating chronic disease, the present study tested the hypothesis that a significant amount of variance in patient satisfaction ratings of provider behavior would be explained by patients' current assessment of their health and their social circumstances. More favorable patient ratings of the art, technical quality and efficacy of their care givers were found to be significantly associated with more positive general health perceptions, fewer days spent in bed due to health problems and lower scores on a widely used depression scale, as well as with age and ethnic background. These data provide evidence indicating that patient satisfaction measures are sensitive to and confounded by patients' perceived health, view of life and social circumstances. It is suggested that if patient satisfaction ratings are to be used as indicators of the quality of health care delivery, there is a need to account for the variance attributable to measurable psychological, social and demographic factors.

California↗
PubMed1982

Basic proteins of rodent peripheral nerve myelin: immunochemical identification of the 21.5K, 18.5K, 17K, 14K, and P2 proteins.

Proteins in peripheral nervous system and central nervous system myelin and homogenates of sciatic nerve and brain from young and adult mice and rats were characterized with affinity-purified anti-P2 and anti-myelin basic protein sera after electrophoretic transfer from sodium dodecyl sulfate-polyacrylamide gels to nitrocellulose sheets. Using this method we have identified a component of rodent peripheral nervous system myelin as P2 protein. Peripheral nervous system myelin also showed the presence of four basic proteins in addition to P2 protein. These were found to be analogous to the 14, 17, 18.5, and 21.5K species found in the central nervous system myelin. A number of high-molecular-weight proteins were also detected with anti-myelin basic protein serum in peripheral nervous system, as well as central nervous system myelin. In addition, we report the presence of a high-molecular-weight P2 cross-reactive protein in rodent brain stem homogenates, but not in central nervous system myelin. Key Words: Basic proteins--PNS myelin--CNS myelin--Immunocharacterization. Greenfield S. et al. Basic proteins of rodent peripheral nerve myelin: Immunochemical identification of the 21.5K, 18.5K, 17K, 14K, and P2 proteins.

Animals↗
PubMed1982

The use of an ROC curve to express quality of care results.

When a quality of care method which results in a continuous score is viewed as a screening device, it is possible to evaluate the efficiency and effectiveness of the score using assessment techniques usually applied to screening tests for disease. Using an independent standard (such as patient outcome) for determining which records truly represent inadequate medical care, for any quality score cutoff we can calculate the sensitivity and the specificity of the screening device for identifying inadequate care. An ROC curve allows the user of a screening test to select a threshold that takes into account both the estimated prevalence of inadequate care at the site and the relative importance placed on false positive and false negative errors. We used an ROC curve to examine the performance of criteria mapping, a chart review system. The criteria map method was employed to evaluate the disposition decision for 421 patients who came to 2 emergency departments with complaints of chest pain. The shape of the ROC curve generated from these data allows the user to evaluate the effect of choosing various cutpoints, acknowledging explicitly the tradeoffs between failure to review cases of inappropriate disposition and needless review of appropriate disposition.

Emergency Service, Hospital↗
PubMed1981

An immunological characterization of the basic proteins of rodent sciatic nerve myelin.

Radioimmunoassays (RIA) for the myelin basic protein (MBP) and P2 protein together with sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) were used to establish the identities of and relationships between the basic proteins (BP) of rodent peripheral nervous system (PNS) myelin. The PNS myelin proteins studied, in order of increasing mobility of SDS-PAGE, are P1, PR (R = rodent) and PB (B = breakdown). The majority of the acid extractable proteins of rodent PNS myelin are MBP related as shown by MBP-RIA. When tested individually, rodents P1, PR and PB were each found to cross-react in the RIA for MBP but not that for P2. The acid extracts of rodent PNS myelin were found to contain P2, although in minute quantities. P2 accounts for approximately 0.05-1.0% of the acid extractable protein in rodent PNS myelin.

Animals↗
PubMed1981

Comparison of a criteria map to a criteria list in quality-of-care assessment for patients with chest pain: the relation of each to outcome.

In a prospective study we compared the ability of two quality assessment methods--the standard criteria list and the criteria map--to predict the appropriateness of the disposition decision for 421 patients with chest pain who presented to two emergency departments. To evaluate the quality of this decision, each patient was followed at home or in the hospital to determine whether an acute condition requiring hospital admission was present. Among the 169 discharged patients, the map scores of the eight with admissible disease were significantly higher than the score for those without admissible disease (p = 0.02). For the 252 admitted patients, a similar relationship between map score and the admissible disease outcome was observed (p = 0.0001). There was no significant relationship between list score and outcome among either the admitted or the discharged patients. Multivariate logistic analyses confirmed the importance of the map score as a predictor of admissible disease. The map score was superior to the list score and to demographic variables in its ability to correctly classify patients with and without admissible disease. The demonstrated relationship between map score and patient outcome enables the map to be used in a quality assurance system. An institution can ensure that physicians review an enriched sample of the inappropriate discharges and the unjustified admissions by selecting admitted patients with low map scores and discharged patients with high map scores.

Adult↗
PubMed1980

The baseline ECG in the evaluation of acute cardiac complaints.

One reason for performing the ECG routinely on asymptomatic persons is to assist the physician in determining the need for hospitalization should acute cardiac symptoms later develop. To establish how often baseline ECGs are actually useful in this situation, we reviewed the records of 236 patients presenting to two emergency departments with the complaint of chest pain. Of these patients, 195 (82.7%) had clinical or ECG findings sufficiently diagnostic that the baseline ECG could not have affected the decision to hospitalize or discharge. For 11 patients (4.7%) with equivocal clinical and ECG findings, a baseline ECG (if it was available) might have been useful in avoiding an unnecessary hospitalization. There was no patient for whom a baseline ECG would have aided in avoiding an inappropriate discharge. The routine ECG has little value as a baseline for emergency comparison when patients later experience acute cardiac symptoms. Routine ECGs as baselines for future comparison should be reconsidered.

Acute Disease↗
PubMed1980

Treatment of surgical emergencies with and without an algorithm.

A patient care algorithm was developed for resuscitation of patients entering the surgical emergency department with hypotension. The diagnostic workup, monitoring, and therapy were progressively excalated according to admission blood pressure and responses to therapeutic interventions. The branching-chain logic is ideally suited for rapid decision making in emergency conditions where the need is most urgent, the time constraints are most severe, and the potential improvements in terms of patient salvage are greatest. Preliminary results from these ongoing clinical trials indicate that (1) physicians can and will use an algorithm for emergency medical service resuscitation; (2) in a university hospital with a large emergency service and a commitment to emergency care, the physicians using the aigorithm performed as well as and in some instances better than those not using the algorithm; and (3) the use of the algorithm may prevent delays in resuscitation and lead to less morbidity and mortality. Thus, we conclude that the algorithm helps to organize emergency care, establish standards, and improve care.

Adult↗
PubMed1980

Factors associated with relief from chest pain following emergency care.

A preliminary study was conducted to explore a range of factors that may be associated with relief from chest pain. Nonhospitalized ambulatory patients (N = 150) were interviewed in their homes shortly after seeking care at one of two hospital emergency rooms. Bivariate and multivariate analyses identified four factors positively correlated with symptom relief: whether someone accompanied the patient to the emergency room; whether the patient feared a heart attack or heart problem; whether the patient believed that providers are able to help their patients; and whether the patient was told that he had not had a heart attack. A fifth factor, the number of history and examination items recorded in the medical record, was found to be inversely related to pain relief. It is suggested that in addition to sociodemographic characteristics of patients and measures of medical care process which are frequently studied, social and psychologic factors be considered as important explanatory variables in studies of health status outcomes.

Adult↗