Search PubMed⌕ Search

Biomedical subjects

J McClelland

Publications and source records attributed to J McClelland.

32 records · Page 2Linked to original sources
PubMed1990

Circadian variation in ventricular electrical instability associated with coronary artery disease.

Although sudden cardiac deaths and ischemic cardiac events clearly occur in a circadian pattern, such a pattern has not been shown for primary arrhythmic events. Because primary arrhythmic events are thought to play an important role in sudden cardiac death, a large series of ventricular stimulation studies was analyzed to determine whether circadian variation in ventricular electrical instability exists. If such a circadian variation could be shown, it could have implications for the conduct and interpretation of electrophysiologic testing and the etiology of circadian variation in sudden cardiac death. Results of 2 drug-free ventricular stimulation studies performed 4 to 28 hours apart in each of 162 patients with coronary artery disease were analyzed. Rate and duration of induced arrhythmia, number of extrastimuli required to induce arrhythmia and changes in these factors between the 2 tests in each patient were analyzed. Comparisons were made by half-day, by hour and in a temporally continuous manner to eliminate errors associated with any single method. No significant circadian variation was found in any electrophysiologic measure of ventricular electrical instability despite adequate statistical power. These findings show that the time of day during which ventricular stimulation tests are performed does not affect test results, and therefore does not need to be controlled during electrophysiologic studies. If these findings are parallel to those in ambulatory patients with coronary artery disease, then circadian changes in ventricular electrical instability may not play as important a role in the circadian pattern of sudden cardiac death as had been previously thought.

Cardiac Pacing, Artificial↗
PubMed1990

Assessment of AIDS-related cognitive changes: recommendations of the NIMH Workshop on Neuropsychological Assessment Approaches.

This article presents an extended (7-9 hours) and a brief (1-2 hours) battery designed to evaluate early cognitive changes associated with seropositive, asymptomatic persons. The battery was recommended by an NIMH Workgroup which was guided by 10 principles in its development. The domains assessed by the battery are: (1) Indicators of Premorbid Intelligence; (2) Attention; (3) Speed of Processing; (4) Memory; (5) Abstraction; (6) Language; (7) Visuoperception; (8) Constructional Abilities; (9) Motor Abilities; and (10) Psychiatric Assessment. Although the battery assesses a wide range of psychological functioning, specific emphasis has been placed on divided and sustained attention as well as speed of processing and retrieval from working and long-term memory. Descriptions of both the traditional clinical tests and tasks used in cognitive psychology are provided. Although the Workgroup strongly recommends the use of the extended battery in order to ensure the most sensitivity, it recognizes that there may be situations in which this is not possible. In order to increase the likelihood that neuropsychological tests will identify neurologically affected CDC Stage II and III seropositive individuals, the Workshop recommends that each patient's protocol be rated by two trained neuropsychologists using the same clinical criteria. The Workgroup also recommends that a concerted effort be made to incorporate data from the extended and the brief batteries in some central data bank.

AIDS Dementia Complex↗
PubMed1989

Evaluation of the UNOS point system for kidney recipient selection.

1. The ultimate distribution of 479 consecutive cadaver donor kidneys in the Los Angeles area was examined to determine whether the distribution had been equitable. Half of the kidneys had been allocated by the UNOS point system (or slight modifications thereof) and half by the transplant centers according to their own criteria. 2. With respect to waiting time, the pool of 1,000 was composed of 14% patients who had waited more than 2 years. The UNOS point system forced the transplantation of more patients (27%) who had waited longer than 2 years than the nonpoint system (11%). 3. Although the waiting pool was composed of 28% waiting for retransplantation, the UNOS point system resulted in transplantation of 16% and the nonpoint system, 8%. 4. In the waiting pool, 16% of the patients had cytotoxic antibodies reactive to more than 80% of the panel, whereas 11% of the transplants by the UNOS point system were transplanted into highly sensitized patients and only 2% of the patients transplanted by the nonpoint system were highly sensitized. 5. In Los Angeles, where 11% of the population is Black, 10% of the kidneys transplanted were into Black patients. Since 18% of the waiting pool of patients were Black, some shortfall was noted. However, this can be attributed to the fact that only 7% of the donors were Black. The importance of increasing donation from the Black community is emphasized. 6. Because of the limited pool size of 1,000 patients only a small number of 0 B,DR transplants were achieved.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation Studies as Topic↗
PubMed1987

Erythrocyte sedimentation rate, plasma and serum viscosity as measures of disease activity in rheumatoid arthritis.

The activity of rheumatoid arthritis was assessed in 96 unselected out-patients by performing a number of clinical measurements and comparing them to ESR, plasma and serum viscosity. It was found that ESR correlated with clinical parameters better than did both plasma and serum viscosity. These tests were repeated 3 months later in 87 of the same patients and again change in ESR correlated with change in disease activity better than did change in plasma viscosity. Plasma viscosity was a consistently more reliable measure of disease activity than was serum viscosity.

Arthritis, Rheumatoid↗
PubMed1987

Kidney preservation.

1. Machine preservation yielded better early graft function than simple cold storage of cadaver donor kidneys with more than 24 hours of CIT. However, there was no difference in one-year graft survival rates comparing machine and cold storage preservation regardless of CIT. 2. The percentage of kidneys that functioned immediately posttransplant progressively decreased from 65% with up to 5 minutes WIT to 45% with more than 20 minutes WIT. One-year graft survival rates fell from 80% with zero WIT to 72% with more than 20 minutes WIT. There was no clear effect of WIT in regrafted patients. 3. Although CIT had no apparent effect on one-year graft survival, the rate of graft loss after the first year was nearly double for kidneys with more than 48 hours CIT. This long-term effect of CIT was evident whether all patients transplanted since 1976 were considered or only CsA-treated patients. The increase in late graft loss was evident in kidneys stored more than 36 hours if the recipient received CsA.

Cold Temperature↗
PubMed1977

Antigenic specificities detected on papainized human granulocytes by microgranulocytotoxicity.

A reliable and routine identification of human granulocyte antigens is possible with an improved microgranulocytotoxicity assay. Freshly isolated, papainized granulocytes, an extended incubation period, and alcohol to prevent the adherence of cells are important factors enhancing cellular reactivity. Absorption studies indicate an absence of B-lymphocyte alloantigens on granulocytes. Five tentative granulocyte specificities were defined with granulocytotoxic non-HLA alloantisera. Sib-pair studies suggest the independent chromosomal segregation of the granulocyte and HLA antigen systems.

B-Lymphocytes↗