Search PubMed⌕ Search

Biomedical subjects

J Ruedy

Publications and source records attributed to J Ruedy.

At least 37 records · Page 2Linked to original sources
PubMed1990

Validity and reproducibility of a screening examination for neurological abnormality in persons exposed to methylmercury.

The validity and reliability of methods of screening for neurologic abnormality were assessed as part of an investigation of an outbreak of methylmercury exposure in two northern Canadian communities. Four hundred and forty-five Cree Indians were examined by one of five neurologists in a complete neurologic examination and by a trained paramedical observer in a short screening examination which included a selection of tests from the complete examination. The screening examinations were recorded on videotape and those for 176 men were reviewed by the five neurologists and the paramedical observer 1 year after the field studies. The prevalence of abnormality assessed in the field screening examination was greater than that assessed during the complete neurologic examination, for neurologic features included in both examinations. However, agreement between examinations in identifying individuals with abnormality was poor with the sensitivity of the screening examination falling under 50% for half of the neurologic features examined. In contrast, specificity was over 80% for 14 of 18 features. Review of the videotapes revealed marked interobserver variation in the assessment of the prevalence of neurologic abnormality and poor agreement with the neurologic examinations in the identification of abnormality in individuals, with kappa less than 0.2 for most neurologic features. The levels of agreement between the neurologic examinations and the screening examinations conducted in the field and by videotape review suggest that neither screening examination provides equivalent information in the identification of the presence of abnormality to that obtained in the neurologic examination.

Female↗
PubMed1990

Pathologic dependence of oxygen consumption on oxygen delivery in acute respiratory failure secondary to AIDS-related Pneumocystis carinii pneumonia.

Oxygen consumption is pathologically dependent on oxygen delivery in ARDS and sepsis. We asked whether oxygen consumption is dependent on oxygen delivery in severe acute respiratory failure secondary to AIDS-related PCP. In five patients who had AIDS-related PCP, diffuse bilateral pulmonary infiltrates, no evidence of bacterial infection, and acute respiratory failure requiring mechanical ventilation with arterial oxygen tensions less than 75 mm Hg while breathing at least 50 percent oxygen, and PEEP greater than 10 cm H2O, we determined oxygen delivery and consumption by calculation from thermodilution cardiac output and arterial and mixed venous oxygen contents. Oxygen delivery was increased using transfusion of two units of packed red blood cells over one hour. Oxygen delivery increased 22 percent (638 +/- 204 to 778 +/- 201 ml/min.m2, p less than or equal to 0.006). Oxygen consumption increased 11 percent (134 +/- 34 to 149 +/- 29 ml/min.m2, p less than or equal to 0.02). The oxygen extraction ratio did not change. We conclude that similar to ARDS and sepsis, oxygen consumption may be pathologically dependent on oxygen delivery in patients who have severe acute respiratory failure secondary to AIDS-related PCP.

Acquired Immunodeficiency Syndrome↗
PubMed1990

The effect of zidovudine on platelet count in HIV-infected individuals.

Seventy-four HIV-infected homosexual males belonging to CDC groups IIB, III, and IVC2 were treated with increasing doses of zidovudine within the Multicentre Canadian AZT Trial. Following a 3 week observation period, consenting volunteers received 600 mg/day for 18 weeks, 900 mg/day for 9 weeks, and 1,200 mg/day for 9 weeks. This was followed by a 6 week washout period after which zidovudine was restarted at 1,200 mg/day for 18 weeks. Patients were followed for a total of 63 weeks. Every 3 weeks they underwent a full clinical and laboratory assessment. For the purpose of this analysis, subjects were divided according to the mean initial platelet value (greater than or equal to 150,000 or less than 150,000/L) into normals (n = 57) and thrombocytopenics (n = 12), respectively. Analysis of variance was used to compare the mean platelet values at each zidovudine dose. All comparisons were made against baseline values. Zidovudine increased platelet counts in normal and thrombocytopenic subjects. The magnitude of this effect varied depending on the baseline platelet count. Among normals, the platelet count increased from 241,000 +/- 45,000/L at baseline to 261,000 +/- 51,000/L (p less than 0.01). while receiving 600 mg/day of zidovudine. This effect was self-limited, reaching a peak by week 3. The platelet count decreased to baseline values despite increasing the dose of zidovudine to 900 or 1,200 mg/day. The platelet count further decreased to 218,000 +/- 43,000/L during the washout phase (washout vs. 1,200 mg, p less than 0.01).2+ not found to be dose related. The platelet count decreased to 101,000 +/- 34,000/L during the washout phase (washout vs. 1,200 mg/day, p less than 0.07).(ABSTRACT TRUNCATED AT 250 WORDS)

Canada↗
PubMed1989

Acute respiratory failure secondary to Pneumocystis carinii pneumonia in the acquired immunodeficiency syndrome. A potential role for systemic corticosteroids.

Pneumocystis carinii pneumonia (PCP) remains the most frequent life-threatening complication of HIV infection. A retrospective study was undertaken in an attempt to establish the incidence of acute respiratory failure (ARF) in AIDS-related PCP, its mortality, and the impact of adjuvant systemic corticosteroids on its outcome. Of 127 AIDS-related PCP episodes diagnosed at St. Paul's Hospital between Jan 1, 1981, and March 31, 1987, 27 developed ARF (21 percent), and the 24 who consented to ICU admission for ventilatory support were reviewed. All were given IV pentamidine or trimethoprim-sulfamethoxazole or both sequentially. Overall mortality of ARF secondary to AIDS-related PCP was 50 percent. The use of adjuvant systemic corticosteroids was associated with a decreased mortality. Of the 18 patients treated with IV hydrocortisone (400 to 1,000 mg/day in divided doses for the duration of ARF followed by a tapering regimen over 10 to 15 days), seven (39 percent) died, while five of six (84 percent) treated without corticosteroids died (p = 0.05). Survivors received ventilation for 5 +/- 2 (mean +/- SD) days and all were discharged from hospital after 20 +/- 4 days. Survivors were also younger (34 +/- 8 vs 43 +/- 10 years, p = 0.034) and presented earlier (14 +/- 3 vs 34 +/- 7 days after onset of symptoms p = 0.017). Known AIDS, previous PCP episodes, and arterial blood gas values at the onset of ARF did not correlate with outcome. We conclude that ARF secondary to AIDS-related PCP merits aggressive management. In particular, younger patients presenting early after the onset of respiratory symptoms appear to have a better prognosis. The decreased mortality associated with the use of adjunctive corticosteroids supports the need for prospective controlled evaluation of this therapeutic modality.

Acquired Immunodeficiency Syndrome↗
PubMed1989

A profile of academic physicians in British Columbia.

To determine the extent of involvement of British Columbia's physician community in the operation of the province's only medical school, the authors sent questionnaires to all physicians who had any affiliation with the University of British Columbia (UBC). About 20 percent of the province's physicians were involved in some capacity with the UBC Faculty of Medicine, which accepts about 120 students into the first year annually. Most faculty held "clinical" appointments, meaning that they pursued largely non-academic careers. Full-time academic appointees worked more than 20 percent more hours annually than did their "clinical" counterparts, and average hours for men exceeded those for women. As many as two-thirds of the full-time faculty were also engaged in sufficient clinical practice activity to be classified as full-time practicing physicians by a definition adopted by a provincial Joint Medical Manpower Committee.

Adult↗
PubMed1988

Clinical skills of medical residents: a review of physical examination.

Students are introduced to techniques of physical examination at medical school. However, their skills are deficient at the time of graduation, and with the increasing shift of clinical teaching away from the bedside and into the conference room it is expected that these skills will weaken in succeeding generations of physicians. A practical and satisfactory method of addressing this problem during internship and residency training has not been forthcoming because of the lack of a regular forum for the teaching of clinical skills in busy tertiary referral hospitals and the shortage of teachers with the necessary skills and commitment to teaching a large number of house staff. We describe a program whose unique hierarchical approach has permitted a detailed ongoing review of physical examination. One clinician was able to teach 24 residents by instructing a small group of senior residents, who in turn, after practising with clinical clerks, taught groups of junior residents.

Clinical Clerkship↗
PubMed1987

Intraoperative cyanosis: a case of dapsone-induced methaemoglobinaemia.

Intraoperative cyanosis is most commonly caused by hypoxaemia. The anaesthetist is required to perform a rapid series of diagnostic manoeuvres and take remedial action. Occasionally methaemoglobin, sulfhaemoglobin, or haemoglobin M, undetected preoperatively, is the cause of the cyanosis. We report a case of methaemoglobinaemia secondary to dapsone ingestion that was diagnosed intraoperatively. Dapsone, a sulfone, is used therapeutically to treat leprosy and dermatitis herpetiformis. The differential diagnosis of cyanosis, and the origin and fate of methaemoglobin are discussed. In addition the diagnostic steps and the laboratory investigations required to make the diagnosis are listed.

Adolescent↗
PubMed1987

Therapeutic implications of sodium abnormalities in hypertension.

Abnormalities in cellular sodium transport have been demonstrated in leukocytes and erythrocytes of some patients with essential hypertension. Some patients with essential hypertension retain more sodium on a high-salt diet, despite an accompanying increase in pressure. Some epidemiological studies suggest a relationship between dietary sodium intake and essential hypertension. The biological significance of these findings remains uncertain. There is too little evidence to support dietary sodium restriction as a primary preventive measure in essential hypertension. Restriction of dietary intake of sodium to 80 mmol/day results in a reduction in blood pressure in a minority of patients with essential hypertension.

Aging↗
PubMed1985

Treatment of Pseudomonas and Serratia infections with ceftazidime.

The effectiveness and safety of parenterally administered ceftazidime were assessed in 20 patients with infections caused by Pseudomonas aeruginosa or Serratia marcescens. There were six infections involving the urinary tract, six wound infections, one respiratory tract infection, three septicaemias, one empyema, one mastoiditis and two infections of the epididymis. Sixteen of the isolates were resistant to at least one aminoglycoside antibiotic. Fifteen patients were clinically and bacteriologically cured, two patients improved, but had relapses and three patients showed no response. The lack of clinical response was due to the development of resistance by P. aeruginosa in two patients with osteomyelitis, one of whom also had diabetes mellitus. The third patient who had chronic lymphocytic leukaemia developed post-operative osteomyelitis and septicaemia with serratia. She did not respond to treatment. Side effects consisted of a positive direct Coomb's test without evidence of haemolysis in two patients and a mild maculopapular rash in one patient.

Adult↗
PubMed1984

Penicillamine and other remittive agents in rheumatoid arthritis: comparisons and interaction.

Penicillamine treatment of rheumatoid arthritis was compared with gold and other remittive agents by reviewing the literature and studying the patients in our penicillamine clinic with respect to their previous responses to chrysotherapy. Penicillamine compares well with other remittive agents with respect to efficacy and toxicity. Prior chrysotherapy does not determine or predict the subsequent efficacy of penicillamine . Patients who reacted adversely to gold tended to react adversely to penicillamine; proteinuria and rash tended to recur.

Anti-Inflammatory Agents↗
PubMed1983

Methyl mercury exposure in northern Quebec. I. Neurologic findings in adults.

Cree Indians of northern Quebec were exposed to methyl mercury through contamination of local fish. The relationship between measures of exposure and neurologic abnormalities was studied in two communities in 1978 by comparing the exposure of 41 "cases" with selected neurologic abnormalities with that of 179 normal "controls." In the community of Mistassini, a significant positive association was found between neurologic abnormalities and methyl mercury exposure; in Great Whale, the association, although also positive, was not statistically significant. However, although allowance was made for confounding variables, it remains possible that the effects are not entirely attributable to methyl mercury. Further, the data do not permit estimation of a threshold level of exposure above which excess neurologic abnormalities might occur, because recent levels of exposure do not reflect those of the past. Whether the abnormalities observed in this study will remain stable, regress, or progress can only be determined by continued surveillance.

Adult↗
PubMed1983

Methyl mercury exposure in northern Quebec. II. Neurologic findings in children.

The relationship between prenatal exposure to methyl mercury and neurologic and developmental abnormalities was ascertained among 234 Cree Indian children aged 12 to 30 months from four northern Quebec communities. A pediatric neurologist, "blinded" to the children's level of exposure, assessed neurologic, physical, mental, and psychosocial development. Methyl mercury exposure was estimated from maternal hair segments representing the period of pregnancy. Abnormality of the tendon reflexes, observed in 13 boys (11 per cent) and in 14 girls (12 per cent), was positively associated with methyl mercury exposure only in boys and there was no consistent dose-response relationship. Other neurologic disorders were less prevalent and none was positively associated with exposure; indeed, incoordination was negatively associated with exposure in girls. The mild, isolated neurologic abnormalities found after prenatal exposure to methyl mercury in northern Quebec were different from the effects of prenatal exposure described in other areas, and their clinical importance can be determined only by continued medical surveillance.

Adult↗
PubMed1983

Prevalence of neurological abnormality in Cree Indians exposed to methylmercury in northern Quebec.

The prevalence of neurological abnormality was determined among Cree Indians of northern Quebec who were exposed to methylmercury through contamination of local fish. A medical team examined each subject, without knowledge of the subjects' methylmercury exposure, and assessed nystagmus, co-ordination and gait, tremor, movements and reflexes, sensation, stereognosis, 2 point discrimination, visual fields and hearing. Tremor, incoordination and abnormal reflexes were the most prevalent neurological abnormalities, but other major manifestations of methylmercury toxicity (impairment of peripheral sensation, astereognosis and concentric constriction of visual fields) were seen infrequently. Abnormalities in Quebec were much less severe than in previous reported outbreaks of methylmercury poisoning. Since no single clinical syndrome is pathognomonic of methylmercury poisoning, the presence of neurological abnormality does not establish that it is causally related to methylmercury exposure.

Adult↗
PubMed1983

Penicillamine compared to previous chrysotherapy in rheumatoid arthritis.

Of 331 patients in our 3 penicillamine clinics, 312 had been taking chrysotherapy previously. In 232 patients, responses to both drugs could be determined: there was no difference in the response rate to penicillamine when patients in the largest clinic with good and those with poor responses to gold were compared. Adverse reactions to penicillamine were more frequent in patients who had reacted adversely to gold in 2 of the 3 clinics. Proteinuria tended to occur more frequently in patients who had had proteinuria when taking gold than in patients who had not had gold-induced proteinuria.

Adolescent↗
PubMed1981

Nutritional status of Quebec Indians.

The nutritional status of more than 80% of adult Indians in three bands in a remote area of Quebec was studied during the summer of 1978 and the findings were compared with the results of the 1970 and 1972 Nutrition Canada national and Indian surveys in which the Indian participation rate was 30%. In the present study, hematocrit, serum iron, transferrin saturation, serum vitamin E, serum folic acid, and urine thiamin excretion patterns showed only minor differences from Nutrition Canada's national and Indian survey. Serum total protein values were slightly higher in Indians than in the national sample, consistent with previous findings. A higher percentage of subjects had low serum concentrations of vitamin A and ascorbic acid than in the previous Indian survey, but not to such a marked degree.

Adult↗
PubMed1981

Verapamil.

Explore the source record for details and available documents.

Action Potentials↗