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Biomedical subjects

R L Evans

Publications and source records attributed to R L Evans.

At least 73 records · Page 4Linked to original sources
PubMed1991

Characteristics of hospital patients receiving medical rehabilitation: an exploratory outcome comparison.

This study classified consecutive hospital admissions to acute medical and surgical wards (n = 3,170) into clinical subgroups based on diagnostic, prognostic, and functional criteria. The groups were (1) independent, (2) terminal, (3) medical, (4) dementia, and (5) rehabilitation candidate. Medical record data from hospital admission, discharge, and nine-month follow-up were collected. The groups had unique patterns of survival, residence, and use of health care services during follow-up. Rehabilitation participants were compared with a group similar in age, major diagnostic category, and functional ability, who did not receive rehabilitation. Only 21% of persons meeting the study criteria for rehabilitation actually received rehabilitation services. At follow-up, participants in rehabilitation had lower mortality, spent less time in skilled nursing care, and were less frequently hospitalized. Although exploratory in nature, this study supports previously observed benefits of rehabilitation. In combination with clinical assessment, the process of identifying patient subgroups may be useful in planning interventions more uniformly and in developing measures to reduce selection bias in rehabilitation admission decisions.

Aged↗
PubMed1991

Factors predicting satisfactory home care after stroke.

This study prospectively investigated factors predicting optimal poststroke home care. One hundred and thirty-five first occurrence stroke patients and their primary support persons were evaluated during the initial hospitalization after stroke and again one year poststroke. Discriminant function analysis was used to identify two groups from the baseline data: home care situations which were rated optimal and those which were not. Group membership was predicted and validated with 72.6% accuracy. Patients at risk for less than optimal home care had caregivers who were (1) more likely to be depressed, (2) less likely to be married to the patient, (3) below average in knowledge about stroke care, and (4) reporting more family dysfunction. Our findings suggest that caregiver-related problems can have a collective effect on rehabilitation outcome and that treatment should reduce caregiver depression, minimize family dysfunction, and increase the family's knowledge about stroke care.

Aged↗
PubMed1990

Monoclonal antibody to the interferon-inducible protein Leu-13 triggers aggregation and inhibits proliferation of leukemic B cells.

Interferon (IFN)-alpha inhibits DNA synthesis stimulated by low molecular weight B-cell growth factor (BCGF) in hairy cells in vitro, suggesting that the therapeutic efficacy of IFN-alpha in hairy cell leukemia (HCL) involves growth inhibition of malignant B cells. Evidence that the 16-Kd cell surface protein Leu-13 mediates an antiproliferative signal in T lymphocytes and is IFN-inducible in endothelial cells prompted us to examine the expression and functional role of this molecule in leukemic B cells. Leu-13 density, determined by flow cytometry, was upregulated in vitro and in vivo by IFN-alpha on malignant B cells from patients with HCL, chronic lymphocytic leukemia, and prolymphocytic leukemia. Monoclonal anti-Leu-13 triggered homotypic aggregation of leukemic B cells via an adhesion pathway that was not inhibited by antibodies to leukocyte function associated antigen-1 (LFA-1) or intercellular adhesion molecule-1 (ICAM-1). Moreover, anti-Leu-13 potentiated the inhibitory effects of IFN-alpha on BCGF-stimulated DNA synthesis, assessed by [3H]-thymidine and [3H]-deoxyadenosine incorporation into DNA. These results indicate that Leu-13 is part of a novel IFN-inducible signaling pathway which may modify the growth and adhesive properties of leukemic B cells under physiologic or therapeutic conditions.

Antibodies, Monoclonal↗
PubMed1990

The effect of age on digoxin pharmacokinetics in Fischer-344 rats.

Digoxin protein binding and pharmacokinetics were studied in 4-, 14-, and 25-month-old male Fischer-344 rats to determine if there were age-dependent changes in digoxin disposition. Serum protein binding did not differ among age groups. The average percentage unbound digoxin for all animals was 61.3 +/- 5.3% (means +/- SD, n = 15). For pharmacokinetic studies, [3H]digoxin and 1 mg/kg unlabeled digoxin were administered as an intravenous bolus dose to animals from each age group. The [3H]digoxin terminal elimination half-life was 2.0, 2.3, and 2.5 hr, respectively. The steady-state volume of distribution in the three age groups was 1.51, 1.49, and 1.27 liters/kg, respectively. Total body clearance for the three age groups was 14.2, 12.1, and 7.5 ml/min/kg, respectively. Analysis of variance of these data followed by Duncan's multiple range test indicated a significant decrease in clearance in the aged rats (25-month-old, p less than 0.05). This age-dependent decrease in clearance suggested that digoxin pharmacokinetics could be a significant factor in age-related alterations in digoxin cardiotoxicity in the rat, as it is in humans, and that the Fischer-344 rat could be a useful model for studies of digoxin pharmacokinetic changes with age.

Aging↗
PubMed1990

Effects of prospective payment financing on rehabilitation outcome.

A suspected benefit of paying hospitals per diagnostic related groups (DRGs), i.e. the prospective payment system (PPS), is that lengths of stay (LOS) and costs may be reduced. A potential adverse effect is that providers may discharge patients to reduce costs regardless of clinical consequence. The Veterans Administration (VA) is one of the first agencies to adopt PPS for rehabilitation. This study analyzed the effects of PPS on LOS, readmission rate, nursing home placement (NHP), and referral for Home Health Care (HHC) on a 22 bed rehabilitation unit. One hundred and eighty-seven patients discharged in 1987, prior to the program, were compared (using t-tests) with 215 discharges in 1988, after PPS was established. There were no significant differences in demographics, self-care ability, or in readmissions. Referrals for HHC decreased significantly. LOS decreased from 29.3 days (SD = 16.4) in 1987 to 26.4 days (SD = 14.1) in 1988 (t = 5.3, p less than 0.01). However, 24 more patients were discharged to nursing homes in 1988 (N = 54, 25%) than in 1987 (N = 30, 16%), which represents an increase of 64% (p less than 0.05). Findings suggest that PPS may defer home care in favor of placement. Clinicians need to assess whether reducing inpatient LOS justifies increased use of nursing homes. Further research on the effects of PPS is needed to determine: (a) impact on clinical aspects of rehabilitation; and (b) if other funding mechanisms are more appropriate.

Diagnosis-Related Groups↗
PubMed1990

Family satisfaction with medical care after traumatic brain injury.

Ratings during acute and follow-up care by 35 families having members with traumatic brain injury showed none of the medical facilities met families' needs though some aspects of patients' care were rated higher in hospitals. Findings suggest comprehensive surveys are needed.

Adolescent↗
PubMed1990

Prospective payment for rehabilitation: effects on hospital readmission, home care, and placement.

Suspected benefits of a prospective payment system (PPS) in which hospitals are paid by diagnosis-related groups (DRGs) are that hospital lengths of stay and costs may be reduced. The US Department of Veterans Affairs is one of the first agencies to adopt PPS funding for rehabilitation; this early adoption of PPS provides a unique opportunity to test for both beneficial and adverse outcomes. This study compared hospital stay, readmission rate, and incidence of nursing home placement before and after introduction of PPS on a 22-bed rehabilitation service. Hospital stay decreased from 29.3 days to 26.4 days, but 64% more patients were discharged to nursing homes. Findings suggest that PPS may overlook home care in favor of placement, which neutralizes the cost benefits of the proposed reimbursement system. Further research on the effects of PPS is needed to determine (1) impact on clinical aspects of rehabilitation and (2) whether other funding mechanisms are more appropriate.

Diagnosis-Related Groups↗
PubMed1990

Evaluation of the interaction of lithium and alprazolam.

A potential pharmacokinetic interaction between lithium and alprazolam was studied in 10 normal subjects. Pharmacokinetic parameters were determined from the following regimens: single-dose alprazolam, multiple-dose lithium, and multiple-dose alprazolam with lithium. Steady-state alprazolam clearance during multiple dosing with lithium was not different from that with the single dose of alprazolam. Lithium renal clearance decreased when it was coadministered with alprazolam (31.2 vs. 22.4 ml/minute, p less than 0.05). There was a small but significant increase in the steady-state area under the curve for lithium in the presence of alprazolam (10.3 vs. 11.1 mEq/hour/liter). The small increase in the serum lithium concentrations and decrease in lithium renal clearance was probably the result of lower urine flow rates (1.46 vs. 0.98 ml/minute, p less than 0.05) with the combination of the drugs. This is supported by a weak but significant linear relationship between urine flow rates and lithium renal clearance (N = 57, r = 0.353, p = 0.007). The percent of daily lithium dose recovered at steady-state from the 24-hour urine collection decreased significantly from 93.6% to 78.2% in the presence of alprazolam. This suggests that alprazolam may decrease lithium absorption. The results of this study do not support a definitive interaction of lithium and alprazolam and there is little clinical significance to the small rise in serum lithium concentrations.

Adult↗
PubMed1989

IFN-gamma and IFN-alpha induce the expression and synthesis of Leu 13 antigen by cultured human endothelial cells.

Leu 13 is a 16 kDa human lymphocyte surface Ag and monoclonal anti-Leu 13 induces T cell aggregation and alters T cell proliferation. In previous studies using anti-Leu 13, Leu 13 Ag has been detected on endothelial cells (EC) of arteries, capillaries, and veins in human tissue sections. In contrast, in this study using the same antibody, Leu 13 Ag could not be detected on unstimulated cultured human umbilical vein endothelial cells (HUVEC) by indirect immunofluorescence, immunoperoxidase staining, or immunoisolation of radiolabeled Ag from labeled endothelial cells. However, when HUVEC were cultured with IFN-gamma, Leu 13 Ag was demonstrable using all three detection techniques. Leu 13 Ag was detectable after 24 h of incubation with IFN-gamma (30 U/ml) and was maximally expressed after 72 h. After removal of IFN-gamma, Leu 13 Ag progressively declined back to basal levels by 4 days. Induction of Leu 13 Ag expression by IFN-gamma was suppressed by cycloheximide. Although Leu 13 Ag expression was also induced by IFN-alpha, PMA, and IL-1 were inactive. When HUVEC were incubated with IFN-gamma, surface-labeled with 125I, and then solubilized, anti-Leu 13 immunoisolated a 16-kDa radioactive band that comigrated with Leu 13 immunoisolated from T cells. Similar results were obtained using HUVEC that were metabolically labeled with 35S-methionine. These results demonstrate that HUVEC stimulated with IFN-gamma and IFN-alpha express Leu 13 Ag on their surface and suggest that exposure of EC to IFN may induce EC to develop new functional properties at sites of inflammatory and immune reactions.

Antibodies, Monoclonal↗
PubMed1989

Timing of social work intervention and medical patient's length of hospital stay.

Findings report that hospital inpatients who receive social work intervention present difficult problems and have longer-than-average lengths of stay and that the earlier in the hospitalization that intervention occurs, the shorter the stay will be. A total of 243 patients referred for social services at a 440-bed teaching hospital were evaluated. Paired t-tests indicated a significant difference in the mean length of stay based on normative data. Timing of the intervention accounted for a significant amount of variance (13 percent) in length of hospital stay. The major clinical implications of the study are that social work intervention has the potential to decrease length of hospitalization, and that this methodology may be used reliably to evaluate changes in discharge planning protocol.

Adult↗
PubMed1989

Caregiver assessment of personal adjustment after stroke in a Veterans Administration Medical Center outpatient cohort.

We evaluated 80 stroke patients to examine the contributions of caregiver anxiety, self-care ability, age, time since onset, marital and residential status, and need for health care services on personal adjustment as reported by caregivers. Mean age of the patients was 65.4 years, and the average time from stroke onset to evaluation was 415 days. Multiple regression analyses indicated that a significant amount of variance in patient adjustment was accounted for by caregiver anxiety (R2 = 0.28, p less than 0.05) and patient self-care ability (R2 = 0.13, p less than 0.05). Compared with community norms, stroke patients were reported to be more depressed, confused, and anxious and they demonstrated fewer household management skills. Stroke patients were not different from a normative sample on measures of interpersonal involvement or social activity. Caregivers had high levels of anxiety compared with norms. Our results may aid in developing methods for identifying stroke patients and caregivers at risk for suboptimal adjustment.

Academic Medical Centers↗
PubMed1988

Tentacle contraction in Heliophrya erhardi (Suctoria): the role of inositol phospholipid metabolites and cyclic nucleotides in stimulus-response coupling.

Extracellular stimulation of Heliophrya erhardi with 15 V, 100 ms induces tentacle contraction. The effects of a number of pharmacological agents on response latency (time from stimulus to start of contraction) and contraction time (time for tentacles to reach 20% of their original length) were recorded. Contraction was enhanced in the presence of phorbol ester TPA and R59022, both of which increase activation of diacylglycerol-dependent protein kinase C. Lithium ions, which are known to inhibit dephosphorylation of inositol 1-phosphate, also affected the response, causing a decrease in latency and increase in contraction time. These results strongly implicate products of inositol phospholipid metabolism in stimulus-contraction coupling. The latency of contraction was reduced in the presence of IBMX, a nonspecific inhibitor of cyclic nucleotide phosphodiesterases. Application of membrane-permeable cyclic nucleotide analogs led to an increase in latency and contraction time for cAMP analog, but a decrease in both parameters for cGMP. This suggests that the two cyclic nucleotides have opposing roles in modulating the response. The possible roles and interactions of membrane phospholipid metabolites and cyclic nucleotides in the control of tentacle contraction of H. erhardi are discussed.

1-Methyl-3-isobutylxanthine↗
PubMed1988

Effects of apomorphine on punished and unpunished responding in the rat.

Apomorphine has been reported to increase shock-suppressed drinking, which suggests that it might have antianxiety activity. Because some drugs that increase shock-suppressed drinking are not active in other punishment procedures, the effects of apomorphine on punished and unpunished responding maintained by a multiple fixed-interval, fixed-interval schedule of food presentation were studied in rats. At doses from 3.125 to 100 micrograms/kg, apomorphine failed to increase punished or unpunished responding. In contrast, pentobarbital produced large increases in punished responding maintained by a fixed-interval schedule of food presentation.

Acoustic Stimulation↗
PubMed1988

Identifying factors associated with health care use: a hospital-based risk screening index.

The purpose of the current study was to identify variables near hospital admission that could effectively discriminate patients at risk for nursing home placement, long hospital stay, or readmission. Risk factors reported in the literature were used to predict hospital outcome for 532 admissions. Factors that discriminated type of outcome included: two or more chronic medical conditions, living alone or being admitted from a nursing home, dependent ambulation, poor mental status, psychiatric comorbidity, prior admission, age over 75, and being unmarried. Using these criteria, an index was developed to determine risk for placement, readmission, or lengthy stay. Use of cumulative risk scores can result in accurate prediction of outcome and may be useful in targeting patients for intervention. Performance characteristics of the risk index are discussed.

Aged↗