Biomedical subjects
Publications and source records attributed to A D Johnson.
An abscess of the left thigh due to a fistula between a tuberculous 5th lumbar vertebra, the sigmoid colon and the muscles and subcutaneous tissues of the left thigh is described. This appears to be a unique occurrence and was only diagnosed at post-mortem. The treatment and diagnosis are discussed.
Twenty-four patients with severe congestive heart failure and cardiomegaly in whom the presence or absence of significant coronary disease could not be ascertained clinically underwent fluoroscopy for coronary artery calcification prior to cardiac catheterization. Ten of the patients were found to have significant coronary artery disease, and 14 had normal coronary arteriograms. Coronary artery calcification was found in all ten patients with significant coronary disease, and was absent in all of those patients with normal coronary arteriograms. We conclude that fluoroscopy for coronary artery calcification provides a reliable noninvasive method for differentiating ischemic from nonischemic cardiomyopathy.
Ventriculoatrial conduction complicating ventricular pacing in a patient with ischemic heart disease led to severe clinical disability and hemodynamic compromise. Data obtained at cardiac catheterization documented that ventriculoatrial conduction of the patients' paced beats led to inadequate left ventricular filling pressures, pulmonary congestion and depressed cardiac output. This complication of ventricular pacing can be suspected at bedside examination and emphasizes the importance of considering the possible hemodynamic effects of ventricular pacing when long-term pacemaker therapy is contemplated.
1. The patterns of 14CO2 evolution from specifically labeled glucose substrates by washed bull, ram, boar, rabbit, dog, rooster and turkey spermatozoa were similar and indicated the Embden-Meyerhof and Kreb's cycle pathways as the major route of energy metabolism. 2. Honey bee spermatozoa metabolized glucose-3,4-[14C], glucose-[U-14C] or fructose-[U-14C], but not glucose-1-[14C], glucose-2-[14C]or glucose-6-[14C], indicating the presence of the glycolytic pathway, but the absence of respiration via the Kreb's cycle. 3. The rate of glycolysis exceeded the rate of respiration in the spermatozoa of all the species studied. 4. A preferential utilization of glucose-1-[14C] over glucose-6-[14C] was evident in some sperm samples, but no consistent indication of pentose cycle metabolism was observed, due to considerable variability between samples within each group. 5. Fructose metabolism was greater than glucose metabolism in the rooster, less in the dog, boar and turkey, and similar in the spermatozoa from the other species examined. 6. Only ram and bull spermatozoa metabolized acetate-1-[14C] to any extent.
1. Disc electrophoresis was used to determine the esterase isoenzymes present in adults of the strigeoid trematode Alaria marcianae (La Rue, 1917). 2. Eight esterase bands were found with alpha-naphthyl acetate as the substrate and Fast Blue RR as the dye. 3. From results obtained with inhibitors, four different types of esterases were tentatively identified; cholinesterase (one band), ali-esterase or B-type (one band), arylesterase or A-type (2 bands) and acetylesterase or C-type (4 bands).
When a patient's coronary arteries are anatomically normal, variant angina probably results from transient spasm that narrows and occludes a coronary artery; medical treatment is usually advised. But this distinctive type of pain can also occur in conjunction with atherosclerotic disease, in which case bypass surgery may prove highly effective in relieving symptoms and averting the risk of myocardial infarction.
Primary cell cultures, a continuous cell line, and a diploid cell line were grown on an artificial capillary system. The cells were subsequently infected with Venezuelan equine encephalitis virus, and viral replication was studied. Extracellular fluids harvested from this system contained high titers of virus and were relatively free of cell debris.
The anatomy of the proximal left coronary artery in 33 adult patients with bicuspid aortic valves was compared with that in 33 adult patients with aortic valve disease of other aetiologies and with that in 50 adult control patients with no valve or congenital heart disease. Patients with bicuspid aortic valves had a higher incidence of immediate bifurcation of the left main coronary artery, of left main coronary length less than 10 mm, and of left coronary artery dominance. The mean length of the left main coronary artery was significantly less in the patients with bicuspid aortic valves. These variations from the usual coronary artery anatomy may be part of the developmental abnormalities responsible for bicuspid aortic valves, and require evaluation and consideration when considering angiography and valve replacement in patients with aortic stenosis.
False aneurysms of the left ventricle were observed in 14 patients. They were caused by obstructive coronary arterial disease with resultant myocardial infarction in 11, bacterial endocarditis in 1, a knife wound in 1, and disruption of a ventriculotomy in 1. Most of them extended posteriorly on the lateral radiograph, as opposed to the usual anterior position of true aneurysms. Enlargement was frequently observed on sequential studies. Angiography usually demonstrated involvement of the diaphragmatic or posterolateral segment due to occlusion of the right coronary artery; in contrast, true aneurysms are apical or anterolateral and are due to occlusion of the left anterior descending artery. The frequency of rupture of false aneurysms points up the importance of dinstinguishing them from true aneurysms.
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An unusual case of a single left pulmonary vein draining the left lung and joining the left atrium without venous obstruction is reported. This anomaly occurred in association with partial anomalous pulmonary venous return from the upper lobe of the right lung to the superior vena cava. A similar case has been previously reported from our laboratory. The diagnosis of a single left pulmonary vein can be made by routine chest roentgenography because of the characteristic radiologic appearance of this anomaly. It is important to distinguish this benign entity from more ominous pulmonary radiodensities.
High-frequency diastolic oscillation of the anterior mitral leaflet is a common echocardiographic feature in aortic regurgitation. We have studied a group of 56 patients with aortic regurgitation in whom oscillation of the anterior mitral leaflet was present. Thirty-one of these had similar diastolic oscillation of the posterior leaflet; occasional patients demonstrated oscillation of the interventricular septum or chordae tendineae. The presence of these diastolic oscillations did not correlate with the presence of the Austin-Flint murmur. We conclude that diastolic oscillation of left ventricular structures other than the anterior mitral leaflet can be recorded on echocardiograms of patients with aortic regurgiationmthe mechanism responsible for these oscillations is not known; several possibilities are discussed.
1. Seven major lipids of rat spermatozoa from the caput, corpus and cauda epididymidis were separated and quantitated by TLC. 2. Spermatozoa from the caput epididymidis had a significantly greater (P less than 0.05) content of phospholipid, cholesterol, cholesterol ester and free fatty acid than those from the cauda epididymidis. 3. Spermatozoa from the corpus epididymidis had a significantly greater (P less than 0.05) content of monoglyceride than those from the caput epididymidis and a greater content of phospholipid, cholesterol, free fatty acids and monoglyceride than those from the cauda epididymidis.
The authors describe a simple, inexpensive method of obtaining hemiaxial views of the proximal left coronary artery, using an inflated air wedge to support the patient at the appropriate angle.
Severe peripheral vasoconstriction of the legs due to hypersensitivity to small doses of ergotamine tartrate developed in a patient with migraine headaches. The vasospasm was successfully treated with continuous intra-arterial and intravenous infusion of sodium nitroprusside. The contribution of angiography in the diagnosis and treatment of ergotism is stressed.
A 24-year-old male student had three myocardial infarctions, one prior to and two following the angiographic documentation of normal coronary arteries. A spontaneous episode of variant angina prompted repeat coronary angiography, during which intravenous ergonovine caused spasm of the left anterior descending coronary artery, transient ST-segment elevation, and ischemic chest pain; the previously normal right coronary artery was found to be occluded proximally. This constellation of clinical and angiographic findings suggests that coronary spasm can cause acute myocardial infarction as well as variant angina.
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