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Biomedical subjects

R B Stewart

Publications and source records attributed to R B Stewart.

At least 19 recordsLinked to original sources
PubMed1992

Differences in the hypothermic response to ethanol in rats selectively bred for oral ethanol preference and nonpreference.

The duration of retention of tolerance to ethanol was tested in the alcohol-preferring (P) and alcohol-nonpreferring (NP) rats lines, using ethanol-induced hypothermia as a measure of tolerance. Rats received two injections of ethanol (3.5 g/kg) body wt, IP) and the time between the injections was 1, 2, or 3 days. When one day separated the two injections, tolerance to the hypothermic effect of a second "test" injection was found in both lines. When 2 or 3 days separated the two injections, the P line showed a loss of tolerance and the NP line showed sensitization to ethanol. Sensitization in the NP line grew stronger when the interval between injections was increased from 2 to 3 days. The duration of retention of tolerance to ethanol-induced hypothermia in the P line was shorter than has previously been reported for motor impairment in this line. It appears that the duration of tolerance retention in the P line depends on the test used to measure tolerance. Sensitization to ethanol in the NP line may be associated with low oral ethanol intake.

Alcohol Drinking↗
PubMed1992

Fatigue strength of cantilevered metal frameworks for tissue-integrated prostheses.

The design of the metal alloy framework in cantilevered sections of fixed tissue-integrated prostheses, is critical. Several cross-sectional designs have been advocated, including the popular L-shaped beam, which permits the economical use of space for tooth placement. The fatigue strengths of 15 L-shaped cantilevered framework sections of the same metal alloy were tested. The castings were divided into three groups of five according to vertical wall heights of 4, 5, and 6 mm. Fatigue durability of each sample was determined by counting the number of cycles of vertical forces required to induce catastrophic failure. Statistical analysis revealed significant differences between all three groups in the cycles counted at failure (p less than 0.0019). Fatigue strengths improved significantly with increasing vertical wall height of the L-shaped cantilevered frameworks. In addition, beam flexure was shown to be indirectly proportional to fatigue strength. Theoretical beam deflection was calculated and shown to correlate with the actual beam deflection during the testing. Theoretical calculations in static bending specific for a cross-sectional design may aid in the predictability of fatigue strength.

Dental Alloys↗
PubMed1992

Arterial laser welding with a 1.9 micrometer Raman-shifted laser.

A new 1.9 micron Raman-shifted neodymium:yttrium aluminum garnet (Nd:YAG) laser was used for small vessel welding. Bursting pressures and stresses of sutured and laser-welded arteriotomies created in the rat femoral artery and aorta were measured. Sutured arteriotomies had a significantly higher burst stress than laser-welded arteriotomies. Although there were no significant differences in burst stress at the various laser powers tested, an optimal power was identified. The laser was also used to weld transected rat aortas. The average power delivered was 200 mW for 30 seconds per anastomosis. The average time for completing an anastomosis was 6 minutes compared with 18 minutes when sutures were used. In relation to proximal aortic diameter, there was a 7.9% decrease at the anastomosis immediately (n = 4), and a 6.6% and 4.9% increase occurred at 24 hours (n = 4) and 10 weeks (n = 5), respectively. Acute anastomotic compliance, and compliance at 24 hours and 10 weeks were decreased by 47.2%, 39.5%, and 47.8%, respectively, and were similar to sutured anastomoses. Histology showed little thermal denaturation of the aorta within 0.6 mm of the anastomosis, approximately 1 mm of medial cell death, and nearly normal elastic fiber alignment. One focal false aneurysm was noted at 10 weeks. Although the sutured and laser-welded anastomoses share similar compliance changes, the laser-welded anastomoses are more isodiametric. This preliminary experience with the 1.9 micron laser shows the distinct advantages of a handheld fiber, no requirement for cooling irrigation, speed, and no difference in compliance from sutured anastomoses.

Analysis of Variance↗
PubMed1992

Nocturia: a risk factor for falls in the elderly.

OBJECTIVE: To determine if nocturia is a risk factor for reported falls and bone fractures in older persons. DESIGN: Cross-sectional study comparing falls in men and women with and without nocturia. SETTING: Longitudinal health screening program of ambulatory elderly participants. PARTICIPANTS: Participants included 988 (65.5%) women and 520 (34.5%) men who had completed their tenth annual visit to the program. MAIN OUTCOME MEASURES: Reported falls in the past year and reported bone fractures in the past 5 years. RESULTS: Participants who reported nocturia at least twice during the night were at significantly greater risk to report falls (Odds Ratio = 1.84; 95% CI = 1.05-3.22), and the risk increased in subjects reporting more than three nocturia events (Odds Ratio = 2.15; 95% CI = 1.04-4.44). The significant increase in falls reported by nocturia participants did not result in an increase in reported bone fractures in the past 5 years (P < 0.4360). CONCLUSIONS: Nocturia is an important risk factor for falls in ambulatory elderly persons. Preventive measures should be taken to decrease nocturia events and to decrease the risk of falling during these nocturia events.

Accidental Falls↗
PubMed1992

Acute confusional states in older adults and the role of polypharmacy.

Cognitive impairment resulting from drug therapy in older persons has been well documented for numerous classes of drugs. Unfortunately, the problem of ACS caused by polypharmacy is rarely reported in the medical literature, although we believe that it occurs frequently. Health professionals need more education concerning the risks of drug therapy in older persons and methods of reducing the use of multiple drug therapy. Finally, more research is needed to identify patient and drug factors that lead to drug-induced ACS and cognitive decline in the elderly.

Aged↗
PubMed1992

Lack of association of nonsteroidal anti-inflammatory drug use and cognitive decline in the elderly.

Folstein Mini-Mental State Examination (MMSE) scores obtained in an ambulatory elderly population were used to examine the effect of nonsteroidal anti-inflammatory drug (NSAID) use on cognitive performance. There were 1,310 participants who met the inclusion criteria for the study, of whom 873 (66.6%) were women and 437 (33.3%) were men. There were no differences in mean MMSE scores or in the five dimensions of cognitive function measured by the MMSE for subjects reporting NSAIDs or aspirin use.

Aged↗
PubMed1992

Polypharmacy in psychiatry: three case studies and methods for prevention.

OBJECTIVE: To illustrate problems of overprescribing in the elderly and to make practical suggestions for prevention of polypharmacy. DESIGN: Three cases of polypharmacy in psychiatric patients admitted to the hospital between January and March 1990 are described. Intervention to correct drug-related problems in these patients is described and methods of preventing polypharmacy are discussed. SETTING: Inpatient psychiatry service in a tertiary-care center. PATIENTS: Elderly psychiatry patients (n = 3) taking an excessive number of medications. This polypharmacy was believed to contribute to decreased cognitive and/or physical function. INTERVENTIONS: Medication regimens were reviewed by the physician and pharmacist. Those considered unnecessary or believed to be adversely affecting the patient were discontinued. RESULTS: All patients were discharged on a reduced number of medications, with improvement in cognitive and/or physical function. CONCLUSIONS: Polypharmacy contributes to an increased incidence of adverse reactions in the elderly. Implementation of practical methods for reducing polypharmacy can lead to a reduction in the number of drug-related adverse effects and improved care of the elderly patient.

Aged↗
PubMed1992

Correlates of constipation in an ambulatory elderly population.

Constipation is a common and often perplexing problem for elderly people. The prevalence of self-reported constipation and factors associated with constipation were investigated in 3,166 people over age 65. Twenty-six percent of women and 15.8% of men reported recurrent constipation (p less than 0.0001). There was a significant increase in reported constipation with increasing age (p less than 0.0001). Multiple factors were found to correlate with self-reported constipation. A logistic regression model revealed 13 factors of significance in predicting constipation. The most important factors were age, sex, total number of drugs taken, pain in the abdomen, and hemorrhoids (p less than 0.0001). Specific drugs do not appear to be important factors in constipation in the elderly. Elderly people who report the use of multiple drugs, pain in the abdomen, and hemorrhoids are at increased risk for constipation.

Age Factors↗
PubMed1979

Epidemiology of hyperuricemia in an ambulatory elderly population.

The relationship of serum uric acid concentration to age and sex was assessed in 1,701 participants in a geriatric multiphasic screening clinic. Included were 1,067 women and 634 men. The mean uric acid level for men was 6.35 mg/100 ml compared to 5.44 mg/100 ml for women. No statistically significant increases in serum uric acid between age groups were apparent, except for women over 84 years of age. The mean serum urate concentrations found in this geriatric study are higher than those reported for other population groups, suggesting a higher normal value for the elderly.

Age Factors↗
PubMed1979

Drug use in a geriatric population.

Drug usage was studied in a geriatric hypertension-screening program. A questionnaire was used to collect the required information from patients visiting the clinic during three successive years. The study included 1,711 patients, of whom 76.6 percent were regularly using a drug preparation. A consistent increase was noted in the average number of drug categories used with increasing age, from 1.6 in patients under 70 to 2.6 in patients over 84 years old. The most common drug categories involved were antihypertensive agents, cardiovascular drugs, vitamins, and internal analgesics.

Aged↗
PubMed1979

Efficacy of antiparkinson agents in preventing antipsychotic-induced extrapyramidal symptoms.

The types of extrapyramidal syndrome (EPS) reactions produced by antipsychotic agents and the prophylactic use of antiparkinson agents in preventing EPS are reviewed. EPS are classified as akathisias, dystonias, parkinson-like symptoms and tardive dyskinesia, and have a varied incidence reported to range from 10.6 to 100%. Incidence may vary with age, gender, drug and dosage. The prophylactic use of antiparkinson agents to prevent EPS is controversial. Many psychiatrists believe the effect of EPS on patients is more harmful than the side effects of anticholinergics, whereas others believe that because of side effects, increased cost, greater risk to tardive dyskinesia and improper use, the use of antiparkinson agents cannot be justified. Most studies of prophylactic use of antiparkinson agents have lacked adequate control groups, adequate blinding procedures for investigators rating EPS, uniform definitions of EPS, random sampling and careful reporting of group characteristics such as dosage and drugs received. There is a lack of definitive studies of the value of antiparkinson agents in preventing the occurrence of EPS in patients receiving antipsychotics. A large, multicenter study should be undertaken to resolve the issue.

Antiparkinson Agents↗
PubMed1979

ASHP Midyear Clinical Meeting papers: 1967--1978.

Trends in the types of topics of papers presented at the American Society of Hospital Pharmacists' Midyear Clinical Meetings from 1967 to 1978 are reviewed. A total of 1,210 abstracts of papers presented at the 12 meetings were reviewed. Twenty-three subject categories were identified. Papers were subdivided into four different study types--review, case report, report, and study. Topics such as general hospital pharmacy, management and administration, and drug distribution were emphasized more during the early years of the meeting. Papers on role evaluation, adverse drug reactions and drug use review were presented more frequently in the early 1970s. Therapeutics and general clinical pharmacy were topics consistently emphasized. Case reports increased from 0% in 1967, to 2% in 1972, to 6% in 1978. Review papers decreased from 72% in 1967, to 11% in 1972, to 3% in 1978. Studies increased from 4% in 1967, to 28% in 1972, to 43% in 1978. Concentration on increasing the number of studies presented at the meeting will advance hospital pharmacy and thus improve patient care.

Congresses as Topic↗
PubMed1978

The extent and character of drug consumption during pregnancy.

One hundred sixty-eight obstetrical patients' conditions were monitored prospectively throughout the prenatal, perinatal, and postpartum periods to obtain data on maternal drug consumption. In the prenatal period, all patients received at least two different drug products: 93.4% received five or more, while one patient reported taking 32 different products. The average number of drug products used in the prenatal period was 11.0. The mean perinatal exposure in patients undergoing vaginal delivery was 7.0. Analysis by therapeutic category was performed. Information gathered confirms the fact that pregnant women do take a large number of different types of medications, the consequences of which remain unknown.

Abnormalities, Drug-Induced↗
PubMed1978

Infection of inbred strains of mice with Sendai virus.

A comparative study of the consequences of Parainfluenza type 1 (Sendai) virus infection in inbred (C57B1/6J, C57Br, CBA, DBA) strains and a randomly bred (Swiss white) strain of mice showed significant mortality in the inbred strains but not in the randomly bred ones. This difference may be partly related to the high levels of virus growth obtained in the lungs of the inbred strains contrasted to little or no virus growth in the lungs of the Swiss white mice. A similar difference between these mice was found in the incidence of virus involvement of a variety of mouse tissues. These differences in mortality and in vivo growth of virus were not clearly mimicked in antiviral-antibody production in these different mouse populations.

Animals↗
PubMed1978

Survey of clinical pharmaceutical services in Florida hospitals.

A survey of clinical pharmaceutical services in Florida hospitals is described. Questionnaires were mailed to the pharmacy departments of 210 hospitals containing 50 or more beds; 172 (82%) responded. Data were collected concerning the extent and types of clinical services provided; the reasons for not implementing the services were also obtained. Twenty (12%) hospitals employed a full-time clinical pharmacist. Inservice drug education, formalized drug information, cardiopulmonary resuscitation and patient medication histories were provided by 78%, 47%, 19% and 6% of the hospitals, respectively. Hospitals with a total or partial unit dose drug distribution system seemed more likely to provide clinical services than those with other types of distribution systems. Hospitals employing a clinical pharmacist were engaged in a wider range of clinical services and provided these services to a larger portion of their patient population. The reason most frequently cited for not implementing clinical services was inadequate staff.

Florida↗