Biomedical subjects

J L Floyd

Publications and source records attributed to J L Floyd.

5 recordsLinked to original sources

PubMed1992

Five years experience of predictive testing for myotonic dystrophy using linked DNA markers.

We report on a 5 year experience in providing presymptomatic and prenatal molecular diagnostic services for myotonic dystrophy, using closely linked markers, representing 235 completed results in 161 families. Only 10 analyses (4.3%) proved uninformative, but a further 5 requests (1.9%) could not be reported because of uncertainty in clinical status. Seven of 81 (8.6%) patients considered to be at low risk on clinical grounds were found to be at high risk of carrying the gene. The importance of interpreting molecular results in conjunction with clinical findings is emphasised by the illustrative examples provided. Careful clinical examination and appropriate investigation remain a cornerstone of diagnosis in myotonic dystrophy and are crucial if errors in assigning genotype status by molecular means are to be minimised.

Adolescent↗

PubMed1979

Exercise testing.

Explore the source record for details and available documents.

Coronary Disease↗

PubMed1979

Probe radiocardiography: validation of a technique to routinely determine left ventricular ejection fraction.

We investigated the probability of obtaining a valid radiocardiogram with the first commercially available cardiac probe and a peripheral injection of the radiopharmaceutical. Measurements of left ventricular ejection fraction (LVEF) were obtained in a series of 15 patients undergoing cardiac catheterization. Probe LVEF determinations using central, peripheral and rapid sequential injections correlated well with each other and with ventriculography (r = .88--.98). By documenting its accuracy and precision, this study confirms the validity of a new technique for measuring LVEF.

Cardiac Catheterization↗

PubMed1979

Single injection thallium-201 stress and redistribution myocardial perfusion imaging: comparison with stress electrocardiography and coronary arteriography.

The efficacy of single injection thallium-201 exercise stress and rest redistribution imaging in the evaluation of myocardiacl ischemia was compared with stress electrocardiography and coronary arteriography. Thallium-201 imaging was interpreted at two levels of sensitivity in order to define the circumstances under which it best serves as a screening modality for coronary arteriography. With the prevalence of coronary disease usually found in patients referred for coronary arteriography (75%), unprocessed thallium-201 imaging is as good as stress electrocardiography in identifying patients apt to show coronary artery abnormalities, but not much better than stress electrocardiography in delineating those patients unlikely to show coronary artery disease. In contrast, processed lesion enhanced images showing normal results virtually eliminate the possibility of significant arteriographic findings. With this screening technique, many patients may be spared unnecessary coronary arteriography.

Adult↗

PubMed1979

Serum myoglobin determination: laboratory and clinical evaluation.

Quality assurance examination of a commercially available radioimmunoassay kit for determination of serum myoglobin level conformed the measurement to be accurate, precise, and reproducible under all assay performance variables. Initial clinical evaluation in patients admitted to the Coronary Care Unit revealed comparable diagnostic parameters and earlier detection when compared with the present standard indicator of myocardial necrosis, creatine phosphokinase MB isoenzyme. Interpretation that an elevated myoglobin reflects acute myocardial infarction should be made only in the appropriate clinical context.

Creatine Kinase↗