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Biomedical subjects

J Johnson

Publications and source records attributed to J Johnson.

At least 271 records · Page 15Linked to original sources
PubMed1995

A database of cardiac arrhythmias.

OBJECTIVE: To describe a database of cardiac arrhythmia recordings, useful for the development and testing of ECG rhythm processing or monitoring algorithms and devices. METHODS: The raw data were acquired within the Wisconsin-Dane County emergency medical technician-defibrillation program and contained emergency rhythm recordings of an average length of 30 minutes. The raw data were integrated into a software platform designed for the annotation and visualization of the recordings. RESULTS: Currently the database contains the following arrhythmia episodes: ventricular fibrillation (56), asystole (65), electromechanical dissociation (31), and other arrhythmias (42). The software, resident on personal computers, also can transmit any of the database recordings, through a digital-to-analog converter board, to a device under test. CONCLUSIONS: The database technique described will provide a useful means of objectively assessing electronic devices for their ability to detect arrhythmias. The database is unique in that it contains lengthy episodes of arrhythmias. The database will be extended to include additional cases.

Arrhythmias, Cardiac↗
PubMed1995

Hepatic ultrasonic changes in workers exposed to perchloroethylene.

OBJECTIVE: To determine if subclinical hepatotoxicity is associated with exposure to perchloroethylene at concentrations commonly experienced in the workplace, and whether surveillance with serum hepatic transaminase activity underestimates such effects. METHODS: Hepatic parenchymal echogenicity on ultrasonography and serum hepatic transaminase activity were compared in 29 community based dry cleaning operators exposed to perchloroethylene, and a control group of 29 non-exposed laundry workers. Perchloroethylene exposure was assessed by work history and air monitoring. RESULTS: Mean hepatic transaminase activities were minimally increased in dry cleaners compared with laundry workers. Increased alanine aminotransferase activities, between 1.0 and 1.5 times the normal limits, were found in five of 27 (19%) dry cleaners compared with one of 26 (4%) laundry workers. In contrast, diffuse parenchymal changes in echogenicity, as determined by hepatic ultrasonography, were increased nearly twofold in dry cleaners, occurring in 18 of 27 (67%) dry cleaners compared with 10 of 26 (39%) laundry workers (P < 0.05), and were most strongly associated with increased perchloroethylene exposure in older dry to dry or wet transfer operations (odds ratio 4.2, 95% confidence interval 1.1-15.3). Mean eight hour time weighted average perchloroethylene exposure for dry cleaners was 16 ppm, which is less than the permissible exposure limit of 100 ppm in the United States. CONCLUSIONS: It was concluded that mild to moderate hepatic parenchymal changes occur more frequently in workers exposed to perchloroethylene than in populations not exposed to chemical solvents, and that these effects are underestimated by serum hepatic transaminase activity.

Adult↗
PubMed1995

A survey of new long-stay hospital patients in an Irish health board area.

OBJECTIVES: The aims of this study were to determine the number and rate of accumulation of new long-stay hospital patients in one of Ireland's eight health board areas, to describe their demographic and clinical features, and to assess their needs in relation to possible community placement. METHODS: Demographic and clinical information was obtained on all patients over age 17 who had been continuously hospitalized in area hospitals for more than one year and less than six years on the census day of March 1, 1992. The Community Placement Questionnaire was used to rate the patients' social functioning, problem behavior, physical disability, social contact, and needs for accommodation and day care. RESULTS: The survey identified 175 new long-stay patients, mainly middle aged to elderly. Schizophrenia was the most common psychiatric diagnosis. The bed occupancy rate for these patients was 14 per 100,000 population, and the annual accumulation rate was 2.3 per 100,000 population. CONCLUSIONS: New long-stay patients were chronically ill with significant psychiatric and social disabilities. Involuntary patients were overrepresented in the group. Two-thirds could be placed in the community if facilities were available and had sufficiently high staffing levels.

Activities of Daily Living↗
PubMed1995

The Functional Independence Measure: a comparative validity and reliability study.

The majority of measurement scales used to evaluate outcome in rehabilitation are ordinal in nature and consequently statistically valid assessments of change are difficult to make. The Functional Independence Measure (FIM) can be weighted to possess interval properties, potentially allowing more accurate analysis of change. In this study the FIM was compared to the Barthel Index (BI) to determine its validity, reliability and ease of use in two groups of 25 patients undergoing neurorehabilitation. The FIM was considered to be more valid than the BI, and equally reliable in the assessment of disability. When the two disability scores were compared using subjective and objective assessment the agreement between them was comparable, although neither was high.

Activities of Daily Living↗
PubMed1995

Rural hospital networks: implications for rural health reform.

This article summarizes the perspectives gained in the course of evaluating a 4-year demonstration program that supported rural hospital networks as mechanisms for improving rural health care delivery. Findings include: (1) joining a network is a popular, low-cost strategic response for rural hospitals in an uncertain environment; (2) rural hospital network survival is enhanced by the mutual resource dependence of members and the presence of a formalized management structure; (3) rural hospitals join networks primarily to improve cost efficiency but, on average, hospitals do not appear to realize short-term economic benefit from network membership; and (4) some of the benefits of these networks may be realized outside of the communities in which rural hospitals are located.

Community Networks↗
PubMed1995

Enhancing peer review with communication skill building.

The purpose of this pilot was to improve the peer review process by enhancing the communication skills of staff nurses. Communication skill building was taught to staff members with practice time allotted. The paradigm shift occurred in teaching staff that communication is a learned skill built through practice and not solely a cognitive skill. The results of this pilot demonstrated improved verbal communication, increased comfort with peer review, improved ability to separate performance from individual style differences, and increased accuracy with which staff rate themselves on self evaluations. An indirect benefit has been improved teamwork from increased support among the staff.

Colorado↗
PubMed1994

Randomised trial of thiacetazone and rifampicin-containing regimens for pulmonary tuberculosis in HIV-infected Ugandans. The Makerere University-Case Western University Research Collaboration.

Among HIV-positive patients who received treatment for active tuberculosis, thiacetazone has been associated with cutaneous hypersensitivity and recurrent tuberculosis. No controlled trials have investigated the safety and efficacy of thiacetazone-containing regimens compared with alternative regimens among patients with HIV. In a randomised clinical trial of 191 HIV-positive patients with active pulmonary tuberculosis, we examined the safety and short-term efficacy of isoniazid, rifampicin, and pyrazinamide for two months followed by isoniazid and rifampicin for seven months (RHZ) compared with streptomycin, thiacetazone, and isoniazid for two months followed by thiacetazone and isoniazid for ten months (STH). Between May, 1990, and September, 1991, 191 HIV-positive adult Ugandan patients with acid-fast bacilli sputum smear-positive pulmonary tuberculosis (93% confirmed by culture) received either STH or RHZ. Subjects had a standard evaluation that included Mantoux skin test, complete blood count with differential white blood cell count, and chest radiography. After starting therapy, subjects were followed-up over one year for three outcomes: complications of anti-tuberculosis therapy, early sterilisation of cultures, and survival. Of 191 eligible subjects, 90 received STH and 101 received RHZ. The overall one-year survival was similar for STH and RHZ (65% vs 72%), but when controlled for baseline differences in Mantoux reaction size and absolute lymphocyte count, the relative risk of death for STH compared with RHZ was 1.57 (95% CI 1.0-2.48). Overall, 12 adverse drug reactions occurred in the STH arm (18.2 reactions per 100 person years [PYO]) compared with one in the RHZ arm (1.6 reactions per 100 PYO) for a relative risk of 11.7 (95% CI 1.52-90.0). 10 cutaneous reactions occurred in the STH arm (15.2 events per 100 PYO) compared with one event in the RHZ arm (1.6 events per 100 PYO) for a relative risk of 9.7 (95% CI: 1.24, 75.8). A greater proportion of RHZ patients compared with STH patients had sterilised their sputum within two months (74% vs 37%, p < 0.001). In developing countries, rifampicin-containing regimens should be given, when possible, to HIV-positive patients to reduce drug toxicity and to prolong survival.

AIDS-Related Opportunistic Infections↗
PubMed1994

Syntheses and anticholinesterase activity of tetrahydrobenzazepine carbamates.

The synthesis of a series of alkylcarbamates of 1,5-methano-2,3,4,5-tetrahydro-1H-2-benzazepin-7-ol is reported. Many of these compounds are potent acetylcholinesterase (AChE) inhibitors. The in vitro AChE inhibition, cholinergic effects, acute toxicity, and elevation of brain acetylcholine levels in vivo of this series of compounds are described. A representative compound, 1d (5.6 mg/kg, po), was able to reverse hemicolinium-3-induced amnesia in the mouse passive avoidance assay.

Administration, Oral↗
PubMed1994

Lewy bodies in the brain of two members of a family with the 717 (Val to Ile) mutation of the amyloid precursor protein gene.

A second member of the original family with the valine to isoleucine substitution at codon 717 of the amyloid precursor protein died after the clinical diagnosis of Alzheimer's disease had been made in life. Neuropathological examination of the brain revealed not only severe Alzheimer type pathology, with senile plaques and neurofibrillary tangles, but also Lewy bodies both in the cortex and brainstem. Lewy bodies also occurred in our first case, thus showing striking similarities in these two members of the same family. The possibility exists that the occurrence of Lewy bodies may not be coincidental, but could be genetically determined: the same genetic abnormality which determines the deposition of beta A4 protein, thus triggering of a chain of events leading to Alzheimer's disease, may result in, or predispose to Lewy body formation.

Alzheimer Disease↗
PubMed1994

Intraperitoneal therapy administered through a Groshong catheter.

This report describes a new device for delivery of intraperitoneal therapy. From October 1989 through March 1991, 27 externally accessed Groshong (Bard Access Systems, UT) catheters were placed transabdominally into 24 patients with presumed epithelial ovarian cancer at the conclusion of primary or second-look laparotomy. Total duration of catheter use was 81 months (range, 1-62 weeks). Fifty-seven cycles of intraperitoneal therapy were administered through 18 catheters (range, 1-11). Nine catheters were removed without being used after patients randomized off intraperitoneal treatment arms or were ineligible for intraperitoneal protocols. There were no complications associated with catheter placement or removal. None of the catheters became obstructed or dislodged while in place. There were no cases of infectious peritonitis, although one patient developed an exit-site skin infection. Surgery is not required to remove the Groshong catheter which fosters empiric placement of the device at the time of laparotomy in all patients potentially eligible for intraperitoneal therapy. The device-related infection rate of 4.2 per 100 patients is similar to that described using other implanted devices. Catheter maintenance is easy and patient acceptance is good. The Groshong catheter is a safe, reliable, and acceptable means of delivering intraperitoneal therapy.

Antineoplastic Agents↗
PubMed1994

Behavioral effects of an antiandrogen in adult male rhesus macaques (Macaca mulatta).

This study was designed to determine how to suppress behavioral effects of androgens with a pure non-steroidal antiandrogen, Hydroxyflutamide (OHF). The major dependent variable was yawning behavior of castrated adult male rhesus macaques. Injections of testosterone propionate (TP) increased yawning frequency and cessation of TP injections produced a decrease in yawning frequency. A similar decrease was observed with simultaneous injections of TP and OHF. It has been found that the dose of OHF injected subcutaneously should be 80 times that of TP to block the effects of either physiological or supraphysiological doses of TP.

Androgen Antagonists↗
PubMed1994

The relationship between traumatic exposure, family dysfunction, and post-traumatic stress symptoms in male juvenile offenders.

This study examined some chronic, stressful conditions and some acute, traumatic events which may place youths at risk for specific types of psychopathology. Ninety one delinquent adolescents with histories of serious and repeated crimes were assessed for their exposure to 11 different types of trauma. The subjects were also tested using measures which assess family functioning, and frequency and intensity of Post-Traumatic Stress Disorder (PTSD) symptoms. Results indicated that 24% of the subjects tested met full DSM III-R criteria for PTSD. Both exposure to violence and family dysfunction were significantly associated with PTSD symptomatology. These findings suggest that juvenile offenders may constitute a high risk group for exposure to multiple types of trauma and the development of post-traumatic stress symptoms related to such exposure. This study provides a rationale for future cross-trauma research both within the juvenile offender population and between it and other identified trauma groups.

Adolescent↗
PubMed1994

What are the public health implications of subclinical depressive symptoms?

Longitudinal data from a community study of 9900 adults in the United States show that persons with depressive symptoms, as compared to those without such symptoms, were 4.4 times more likely to develop a first onset major depression over one year. The attributable risk, a measure which reflects both the relative risk associated with depressive symptoms (4.4) and the prevalence of exposure to that risk (24%) and is a useful measure for documenting burden of a risk to the community, indicated that more than 50% of first onset major depressions are associated with prior depressive symptoms. Since depressive symptoms have a high prevalence in the community, but are often unrecognized and untreated in clinical practice, we conclude that their identification and the development of effective treatments could have public health implications for the prevention of associated social morbidity, service utilization and major depression.

Adolescent↗
PubMed1994

Regional blood flow and metabolism in ovine fetuses during severe cord occlusion.

OBJECTIVE: Our purpose was to compare the ovine fetal response to severe, damaging asphyxia resulting from umbilical cord occlusion with that seen in uterine artery occlusion. STUDY DESIGN: Six ovine fetuses were exposed to severe asphyxia produced by partial umbilical cord occlusion for 90 minutes. Fetal blood pressure and heart rate, blood gases, acid base status, electrocorticogram, and electromyogram were recorded. Regional blood flow (radioactive microspheres) measurements were performed at control and 30, 60, and 90 minutes of occlusion and 30 minutes after release. RESULTS: During the period of occlusion pH fell from 7.37 +/- 0.01 (mean +/- SEM) to 6.82 +/- 0.03 at 90 minutes, base excess from 5 +/- 1 to -22 +/- 2 mEq.L-1 and oxygen content from 3.3 +/- 0.4 mmol.L-1 to a nadir of 1.6 +/- 0.4 mmol.L-1 (p < 0.05). There was no significant long-term change in fetal heart rate or blood pressures. The fetal electrocorticogram was profoundly suppressed during asphyxia, and seizure activity was documented after release of occlusion in all surviving animals. Umbilical blood flow fell to 21% +/- 5% of control by 60 minutes of occlusion and remained depressed until release. Brain and adrenal blood flows increased during asphyxia. Heart and intestinal blood flows did not change significantly from control values. Combined ventricular output and spleen, kidney, and carcass blood flow fell during the insult. Oxygen uptake by the cerebral cortex remained stable during occlusion. Oxygen uptake by the lower carcass fell to 15% +/- 7% of control. CONCLUSION: Umbilical cord occlusion produces similar levels of asphyxia and evidence of encephalopathy (seizures), compared with previous experiments with uterine artery occlusion. The fetal response with respect to blood flow redistribution and organ oxygen uptake, however, differs. These differences may signify that with uterine artery occlusion the brain may be more vulnerable, whereas with umbilical cord occlusion the heart may be at greater risk.

Animals↗