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Biomedical subjects

J C Beck

Publications and source records attributed to J C Beck.

At least 19 recordsLinked to original sources
PubMed1992

Inappropriate medication prescribing in skilled-nursing facilities.

OBJECTIVE: To quantify the appropriateness of medication prescriptions in nursing home residents. DESIGN: Prospective, cohort study. SETTING: Twelve nursing homes in the greater Los Angeles area. PARTICIPANTS: A total of 1106 nursing home residents. MAIN OUTCOME MEASURES: The appropriateness of medication prescriptions was evaluated using explicit criteria developed through consensus by 13 experts from the United States and Canada. These experts identified 19 drugs that should generally be avoided and 11 doses, frequencies, or durations of use of specific drugs that generally should not be exceeded. RESULTS: Based on the consensus criteria, 40% of residents received at least one inappropriate medication order, and 10% received two or more inappropriate medication orders concurrently; 7% of all prescriptions were inappropriate. Physicians prescribed a greater number of inappropriate medications for female residents. Regression analysis, corrected for clustering effects within facilities, showed that a greater number of inappropriate medication prescriptions were ordered in larger nursing homes. Inappropriate prescriptions were not related to the proportion of Medicaid (Medi-Cal) residents or the number of physicians practicing in the homes. CONCLUSIONS: Inappropriate medication prescribing in nursing homes is common. Female residents and residents of large nursing homes are at the greatest risk for receiving an inappropriate prescription.

Aged↗
PubMed1992

The use of targeting criteria in hospitalized HMO patients: results from the demonstration phase of the Hospitalized Older Persons Evaluation (HOPE) Study.

OBJECTIVE: To determine the yield of standardized targeting criteria for identifying hospitalized HMO patients who are at high risk for mortality and nursing home placement and, therefore, may be appropriate for comprehensive geriatric assessment. DESIGN: Prospective cohort study. SETTING: Four HMO (Southern California Kaiser-Permanente) hospitals. SUBJECTS: 3,697 patients 65 years of age or older admitted to any inpatient service from July 1 through September 30, 1990. MAIN OUTCOME MEASURES: Screening measures for standardized targeting criteria, administered 24-48 hours after admission. RESULTS: Overall, 35.1% of patients screened met at least one inclusionary criterion, which is considerably higher than other published reports. The most commonly met criteria were incontinence, impairment in performing activities of daily living, malnutrition, and immobility. The percentage of patients meeting at least one criterion and meeting each criterion varied considerably among hospitals. The vast majority of patients (83%) who were judged appropriate for assessment met at least three criteria. CONCLUSIONS: The yield of standardized criteria differs when applied to patients in different health care systems and to patients at different hospitals within a health care system, which may reflect differences in the populations being served and the practice styles of physicians and the delivery system. Because no single criterion identified more than approximately half of patients who were judged appropriate for assessment, it is likely that a battery of criteria will be necessary to identify these patients.

Activities of Daily Living↗
PubMed1992

Multidimensional risk assessment versus age as criterion for retirement of airline pilots.

OBJECTIVE: To determine whether airline pilots over the age of 60 pose a hazard to aviation safety and whether risk assessment could replace age-based retirement. DATA SOURCES: A computer-assisted literature search (MEDLINE), expert consultation, and government reports. STUDY SELECTION: Original studies on flight performance and pilot age; sudden incapacitation, neuropsychological testing, and/or medication use in pilots; and/or non-invasive testing for predicting sudden death or stroke in asymptomatic subjects. DATA EXTRACTION: Pertinent results and methods data were abstracted from the 49 included studies. DATA SYNTHESIS: No study on aircraft accidents or pilot performance has shown an increased accident risk for over-60-year-old pilots. Normal age-related cognitive changes probably have minimal impact on aviation safety up to age 70, given above average health, education, and experience in airline pilots. Cognitive tests have not been validated for predicting flight performance safety, but they can detect early stages of cognitive disease. Cardiovascular incapacitation risk increases with age, but risk factor profiles and non-invasive tests could identify pilots with non-acceptable risk. CONCLUSIONS: An improved medical certification test could identify those pathologic conditions that might occur more frequently in older subjects. If pilots also underwent adequate performance testing, a gradual increase of the retirement age to approximately age 70 would seem justified. In the future, a longitudinal database should be established to validate medical tests for their ability to predict a pilot's accident risk. Using individual pilots as their own controls might be more sensitive than using population-based norm values. Progress in this field would advance medical assessment for other groups such as air traffic controllers or automobile drivers.

Accidents, Aviation↗
PubMed1992

Hormonal regulation of rat renal proximal tubule brush-border membrane ionic permeability.

The effects on ionic permeability of toxins and hormones that activate or deactivate the guanine nucleotide regulatory (G) proteins that govern adenylate cyclase activity were examined in rat renal proximal tubule cell brush-border membranes. These studies demonstrate that activation of stimulatory G (Gs) proteins by cholera toxin or parathyroid hormone and deactivation of inhibitory (G (Gi) proteins by pertussis toxin result in a selective increase in Cl- permeability relative to that of K+ as determined with the potential-sensitive fluorescent probe 3,3'-dipropylthiadicarbocyanine iodide [diS-C3-(5)]. In contrast, activation of Gi by angiotensin II significantly decreases relative Cl- permeability. The selective increase in relative Cl- permeability induced by parathyroid hormone results in an inside-negative potential in membrane vesicles exposed to an inward NaCl gradient that is of sufficient magnitude to stimulate electrogenic, Na(+)-dependent glucose transport. These data suggest that the relative ionic permeabilities of brush-border membranes are tonically regulated by the opposing effects of hormones that act via Gs or Gi proteins. Changes in membrane potential resulting from this regulation may play an important role in modifying transport in the proximal tubule.

Adenylate Cyclase Toxin↗
PubMed1992

Incompetence, treatment refusal, and hospitalization.

Psychiatrists have proposed broadened commitment statues based on need for care and treatment, and under which judges have no role in deciding cases of treatment refusal. The mental health bar has consistently opposed these proposals on constitutional and common law grounds. The authors propose new commitment criteria based on incompetency to decide about hospitalization, and inability to live safely in freedom. The proposed standards would meet the Constitutional requirements, and would permit hospitalization and/or treatment for many persons who are in need but who now go without. The authors recognize that new commitment law without adequate clinical resources will not greatly improve patient care.

Commitment of Persons with Psychiatric Disorders↗
PubMed1991

Ontogeny of Na/H antiporter activity in rabbit renal brush border membrane vesicles.

The development of the Na/H antiporter was studied in renal brush border membrane vesicles (BBMV) from fetal and adult rabbits using isotopic and fluorescent techniques. The kinetics of the antiporter studied by 22Na+ uptake revealed that the Vmax was only 25% of that in the adult; however, the Km's for Na+ were not significantly different. These data were confirmed by a fluorescent assay using the pH-sensitive probe, acridine orange: the Vmax was significantly lower in the fetal BBMV. Conductive Na+ movement was estimated from amiloride-insensitive 22Na+ uptake and the rate of alkalinization induced by K+, an ion whose relative conductance was found to be similar to that of Na+. Although relative Na+ conductance was significantly greater in fetal BBMV, the lower Vmax in fetal vesicles could not be ascribed to this factor. Maternal administration of betamethasone (50 micrograms/kg intramuscularly) for 2 d before delivery significantly increased the Vmax of the antiporter to levels observed in the adult; Km was unaffected. Na/K ATPase activity increased fourfold after betamethasone, but the specific activities of four brush border marker enzymes and the kinetics of Na(+)-glucose cotransport were unchanged. These data indicate that there is a developmental increase in brush border Na/H exchange which is the result of an increase in the number and/or the turnover number of the carriers. Further, these data suggest that the postnatal increase in antiporter activity may be related to the surge in glucocorticoid concentration that occurs perinatally.

Acridine Orange↗
PubMed1991

Emergency psychiatric assessment of violence.

OBJECTIVE: The purpose of the study was to 1) ascertain whether there are clinical and demographic characteristics that distinguish dangerous from nondangerous patients evaluated in a psychiatric emergency service and 2) identify variables that distinguish dangerous patients who are hospitalized form those who are not. METHOD: The authors conducted a case comparison study of 99 psychiatric emergency patients whom staff identified as dangerous to others, that is, violent or potentially violent. Clinical staff were interviewed and records reviewed. These data were contrasted with record review data for 95 nondangerous patients. RESULTS: Log linear analysis showed that 1) variables relating to violence in community samples--age, sex, and past history of violence--related minimally or not at all to violence in this sample and 2) disposition to hospital versus community was associated with psychotic mental status and restraint in the psychiatric emergency service. Patients requiring restraint were more likely to have recently committed assault or battery and to have been brought in by the police. CONCLUSIONS: Enduring personal characteristics of patients relate neither to psychiatric emergency service assessments of current dangerousness nor to the decision to hospitalize. These determinations appear to be related to assessments of current patient state and immediate past behavior.

Adult↗
PubMed1991

Screening recommendations for the elderly.

BACKGROUND: Studies have documented the potential contributions of preventive health care programs. Yet little is known about which screening tests should be included in public health programs for older persons. This study offers recommendations regarding these tests. METHODS: The recommendations come from synthesizing the findings of the US Preventive Services Task Force, the literature, and the consensus of experts in geriatrics, gerontology, and health policy research. The literature was evaluated to identify methodologically sound studies of the prevalence of selected disorders and benefits and availability of screening procedures for those disorders. Experts from various fields specializing in the care of the elderly formed panels to assist in evaluating the literature and providing further information from gerontological and public health perspectives. RESULTS: We recommend vision testing for refractive error; inspection of the skin surface for fungal infection and skin cancer, drug eruptions, and xerosis; a history for symptoms of xerosis; audiometric testing for presbycusis; surveys for hearing loss; otoscopic inspection for cerumen impaction; dental examination for caries; measurement of blood pressure for hypertension; and breast examination and mammography for cancer. CONCLUSIONS: Our study suggests that these screening procedures are useful for public health screening programs. More information is needed on the effects of screening services on the health and functioning of older persons.

Aged↗
PubMed1991

Effects of ginkgolide B, a platelet-activating factor inhibitor on insulitis in the spontaneously diabetic BB rat.

The BB rat spontaneously develops insulin-dependent diabetes mellitus (IDDM) in association with marked insulitis in the islet of Langerhans. Since platelet-activating factor (PAF-acether) is involved in allergic and inflammatory reactions, we tested a PAF antagonist, Ginkgolide B (BN 52021) for potential effects on islet inflammation and diabetes. Diabetes prone BB/Wor rats were treated daily from weaning at 25 days until 105 days of age with either saline (n = 30, controls), 10 (n = 25, low dose) or 20 (n = 30, high dose) mg/kg body weight of BN 52021. The overall incidence of IDDM was unaffected by treatment. Quantitative analysis of insulin area showed a dose-dependent protection of beta cells by Ginkgolide B, reflected in a 6- (low dose) to 8-fold (high dose) (P less than 0.01-0.005) increase in the insulin/glucagon cell ratio compared to the saline treated rats. Ginkgolide B reduced severe insulitis from 84% in the saline rats developing IDDM to 59% (n.s.) in the low and to 33% (P less than 0.001) in the high dose group. These data suggest that PAF inhibitors may prove useful in immunomodulator therapy of IDDM since beta cells are preserved.

Animals↗
PubMed1991

Court based civil commitment of alcoholics and substance abusers.

UNLABELLED: Problem. To study court ordered substance abuse commitment (SAC) in one jurisdiction. We investigated who was evaluated, by whom, and with what outcome. Is SAC primarily a purely civil procedure as originally intended? Are men and women being treated equally? METHOD: Questionnaire survey of court clinicians to determine demographic and clinical status of persons evaluated, the process of evaluation, and the disposition. RESULTS: SAC is common and more frequent in criminal cases than in purely civil ones. SAC of women is clearly influenced by the restricted choices for disposition: either state prison or an unlocked facility. CONCLUSIONS: SAC is an important public health procedure, which courts are using in highly variable and at times unintended ways. SAC has emerged as an alternative to other dispositions in criminal cases involving substance-abusing defendants.

Adult↗
PubMed1991

Explicit criteria for determining inappropriate medication use in nursing home residents. UCLA Division of Geriatric Medicine.

Increasing attention is being paid to inappropriate medication use in nursing homes. However, criteria defining the appropriate or inappropriate use of medication in this setting are not readily available and are not uniform. We used a two-round survey, based on Delphi methods, with 13 nationally recognized experts to reach consensus on explicit criteria defining the inappropriate use of medications in a nursing home population. The criteria were designed to use pharmacy data with minimal additional clinical data so that they could be applied to chart review or computerized data sets. The 30 factors agreed on by this method identify inappropriate use of such commonly used categories of medications as sedative-hypnotics, antidepressants, antipsychotics, antihypertensives, nonsteroidal anti-inflammatory agents, oral hypoglycemics, analgesics, dementia treatments, platelet inhibitors, histamine2 blockers, antibiotics, decongestants, iron supplements, muscle relaxants, gastrointestinal antispasmodics, and antiemetics. These criteria may be useful for quality assurance review, health services research, and clinical practice guidelines. The method used to establish these criteria can be used to update and expand the guidelines in the future.

Aged↗
PubMed1990

A prospective, multicenter study of patients' refusal of antipsychotic medication.

Refusal of treatment with antipsychotic medication was studied prospectively in a sample of 1434 psychiatric patients admitted to four acute inpatient units in state-operated mental health facilities in Massachusetts during a 6-month period. Compared with a control group of patients who accepted prescribed antipsychotic treatment, the 103 patients who refused were older, of a higher social class, and less likely to have been prescribed antiparkinsonian medications. On admission, prior to refusal of medication, patients who refused were found to have significantly higher Brief Psychiatric Rating Scale scores than compliant patients and more negative attitudes regarding their hospitalization and past, present, and future treatment. Treatment refusal had negative effects on the hospital milieu and on the patient; refusers were more likely to require seclusion or restraint and had longer hospitalizations than treatment acceptors. Most refusal episodes ended with voluntary acceptance of treatment. In 23% of cases medications were discontinued. Only 18% of the sample reached formal, judicial review, and in every case that did, involuntary treatment was ordered. The policy implications of these findings are discussed.

Adult↗
PubMed1990

Determination of apical membrane polarity in mammary epithelial cell cultures: the role of cell-cell, cell-substratum, and membrane-cytoskeleton interactions.

The membrane glycoprotein, PAS-O, is a major differentiation antigen on mammary epithelial cells and is located exclusively in the apical domain of the plasma membrane. We have used 734B cultured human mammary carcinoma cells as a model system to study the role of tight junctions, cell-substratum contacts, and submembraneous cytoskeletal elements in restricting PAS-O to the apical membrane. Immunofluorescence and immunoelectronmicroscopy experiments demonstrated that while tight junctions demarcate PAS-O distribution in confluent cultures, apical polarity could be established at low culture densities when cells could not form tight junctions with neighboring cells. In such cultures the boundary between apical and basal domains was observed at the point of cell contact with the substratum. Immunocytochemical analysis of these cell-substratum contacts revealed the absence of a characteristic basement membrane containing laminin, collagen (IV), and heparan sulfate proteoglycan. However, serum-derived vitronectin was associated with the basal cell surface and the cells were shown to express the vitronectin receptor on their basolateral membranes. Additionally, treatment of cultures with antibodies against the vitronectin receptor caused cell detachment. We suggest, then, that interactions between vitronectin and its receptor, are responsible for establishment of membrane domains in the absence of tight junctions. The role of cytoskeletal elements in restricting PAS-O distribution was examined by treating cultures with cytochalasin D, colchicine, or acrylamide. Cytochalasin D led to a redistribution of PAS-O while colchicine and acrylamide did not. We hypothesize that PAS-O is restricted to the apical membrane by interactions with a microfilament network and that the cytoskeletal organization is dependent upon cell-cell and cell-substratum interactions.

Actin Cytoskeleton↗
PubMed1978

Membrane potential-sensitive fluorescence changes during Na+-dependent D-glucose transport in renal brush border membrane vesicles.

When D-glucose was added to a suspension of renal brush border membrane vesicles equilibrated in a Na+-containing medium, there was a rapid transient increase in the fluorescence of the probe, 3,3'-dipropyl thiodicarbocyanine iodide (DiS-C3-(5)). This sugar-induced response was stereospecific for the D isomer, dependent on Na+, inhibited by phlorizin, and blocked by ionophores, valinomycin plus nigericin, which dissipate ionic gradients. The enhancement in fluorescence suggests the entrance into the vesicle of Na+, cotransported with the sugar. This would lead to the interior of the membrane vesicle becoming more positive, resulting in depolarization of the membrane potential. That the sugar induced the transport of Na+ was confirmed by direct measurement of 22Na+ uptake. Thus, the Na+-sugar co-transport system provides a mechanism for D-glucose to stimulate the flux of Na+ as well as for the Na+ electrochemical gradient to enhance the transport of D-glucose.

Animals↗
PubMed1978

The sodium electrochemical potential-mediated uphill transport of D-glucose in renal brush border membrane vesicles.

The uphill transport of D-glucose in renal brush border membrane vesicles was correlated with the Na+ electrochemical gradient. Each component of the electrochemical potential, the membrane potential (outside positive) or the Na+ chemical gradient, when assayed independently, supported the concentrative uptake of the sugar. When the two components were combined, the rates of D-glucose uptake were additive. Accumulation of D-glucose as a function of various Na+ gradients, in the absence of a membrane potential, suggests a 1:1 stoichiometry between sugar and Na+ uptake. These findings are consistent with the role of ionic gradients in energizing uphill solute transport.

Animals↗