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Biomedical subjects

H L Abrams

Publications and source records attributed to H L Abrams.

At least 55 records · Page 3Linked to original sources
PubMed1981

A prospective study of computed tomography, ultrasound, and gallium imaging in patients with fever.

Computed tomography, ultrasound, and 67Ga-citrate imaging were analyzed prospectively in patients thought to have a focal source of sepsis. They were divided into three groups: (a) postoperative, fever greater than or equal to 38.3 degrees C; (b) fever greater than or equal to 38.3 degrees C for less than four weeks, unrelated to surgery; and (c) any fever present for more than four weeks. ROC curves showed no significant difference in the ability of the three modalities to differentiate focal from nonfocal sources of sepsis. If any two examinations were used and either study was abnormal, the sensitivity increased from about 60% to nearly 90% while the false-positive rate increased from about 15% to 25%. When focal disease was diagnosed only if two examinations were abnormal, the false-positive ratio dropped to nearly zero but the sensitivity fell to below 40%. The authors concluded tha all three modalities have a similar ability to detect sepsis and that sensitivity can be increased by using any two of them.

Fever↗
PubMed1980

Renal venography: anatomy, technique, applications, analysis of 132 venograms, and a review of the literature.

Selective renal venography is a simple but important diagnostic procedure which has few complications. A thorough knowledge of renal venous anatomy is essential for its proper performance and clinical application. This is particularly true because renal venous variations are frequent and may interfere with the successful appraoch to retroperitoneal surgery. The method is widely accepted for the evaluation of the renal venous bed in patients with suspected renal vein thrombosis or hematuria of unknown etiology. It depicts the extent of renal venous involvement in renal carcinoma and clarifies the diagnosis in some patients with avascular tumors, renal pelvic carcinoma, and retroperitoneal tumors. It may also be useful in defining the morphologic abnormality when the kidney fails to visualize on urography, in delineating the extent and nature of renal parenchymal disease, and in enhancing the precision of renal vein renin collection.

Adolescent↗
PubMed1980

Classification of the radiological morphology of the mitral valve. Differentiation between true and pseudoprolapse.

The morphology of the mitral valve apparatus was assessed on 100 normal left ventriculograms. Four distinct types of mitral valve were identified according to the position of the mitral fulcrum (the point of attachment of the leaflets to the annulus) and the configuration of the adjacent left ventricular wall (left ventricular fornix) during diastole. Types I and II closely simulated prolapse of the mitral valve (pseudoprolapse) in the right anterior oblique projection during the ejection period. Measurements showed that contraction of the ventricle failed to reduce the diameter of the mitral valve annulus in 26 per cent of normal left ventricles.

Angiocardiography↗
PubMed1980

The changing role of pancreatic arteriography in the era of computed tomography.

Computed tomography (CT) in the assessment of suspected pancreatic disease, although an excellent screening procedure, has certain shortcomings, such as a significant percentage of inaccurate studies, a low predictive value of the finding of a pancreatic mass, failure to detect small lesions, and inability to differentiate localized masses caused by pancreatitis from those caused by adenocarcinoma. Arteriography provides important additional information in patients with clinically suspected pancreatic lesions and positive findings on CT or other noninvasive screening studies in whom surgical resection is contemplated. This procedure helps determine the presence and resectability of adenocarcinoma and can also demonstrate lesions which may resemble pancreatic adenocarcinoma on CT but which, in reality, are nonmalignant or nonpancreatic or both. Arteriography should no longer be used as a screening procedure but should be performed whenever a potentially resectable pancreatic mass, either cystic or solid is suggested by CT.

Aneurysm↗
PubMed1980

Experimental myocardial ischemia. IV. Shape and volume changes during "isolvolumetric relaxation" in normal and ischemic ventricles.

Shape and volume changes were studied in mongrel dogs between end-systole and mitral valve opening (MVO). Biplane left ventricular cineangiograms were performed at 200 frames/sec. The dogs were studied during the control state and during regional myocardial ischemia produced by balloon occlusion of the left anterior descending coronary artery. Outward wall motion, called pre-inflow relaxation (PIR), occurred in all 10 dogs in the control state, most frequently in the apical (seven of 10) and equatorial planes (seven of 10). PIR was seen less frequently during ischemia (13 of 40 measurements vs 19 of 40 measurements during control state), usually in the basal plane (five of 10). The ventricular volume between end-systole and MVO increased in all 10 dogs during the control state (mean increment 4.4 +/- 0.7 ml). Volume increased in eight of 10 dogs during ischemia (mean increment 3.0 +/+ 1.1 ml). The characteristic patterns of wall motion occurring between end-systole and MVO are altered by regional myocardial ischemia. During ischemia PIR occurs in segments of the myocardium with normal perfusion, but usually not in ischemic segments. Biplane ventricular volume between end-systole and MVO increased in 18 of 20 measurements (mean increment 3.6 +/- 0.9 ml).

Animals↗
PubMed1979

Simplifying radiological examinations. The urogram as a model.

The diagnostic yield of one and three film urograms was compared with that of complete examinations to determine whether a moderately complex examination could be simplified without loss of important diagnostic information. Although sensitivity was high (88-93%) and was not altered by increasing the complexity of the examination, the definitive disease diagnoses were more accurate with the three film rather than the one film studies. Specificity increased from 69% to 77-80% with the more complex examinations. A strategy based on terminating the examination if the single film urogram is normal with a three-film examination in positive cases might effect considerable savings, both economic and in terms of gonadal radiation dose, without serious diagnostic loss.

Cost-Benefit Analysis↗
PubMed1979

Complications of coronary arteriography: a follow-up report.

A nationwide survey of complications due to coronary arteriography during 1973--74 yielded responses from 176 hospitals (89,079 coronary arteriograms). The overall mortality rate was 0.14% (brachial, 0.12%; femoral, 0.16%). In the brachial group, the mortality rate was three times as high for non-heparinized as for heparinized patients. In institutions performing fewer than 100 examinations per year, the combined incidence of death, myocardial infarction, and cerebral embolism was five times higher than in institutions performing more than 400 examinations per year. Left main coronary artery or three-vessel disease was present in most patients who died of the procedure. Compared to a previous survey of 1970--71, there was a profound decrease in significant complications (including death, myocardial infarction, and cerebral embolism) and entry site complications such as thrombosis. A reduction in mortality with the femoral technique since 1971 was not accounted for by heparinization and may reflect increasing experience with the method and shorter angiographic times.

Aneurysm↗
PubMed1979

The selection of patients for excretory urography.

Symptoms, signs, and laboratory findings that indicated excretory urography in 1,622 patients, were compared with the radiographs. The chance that an indication would be associated with demonstrable disease was calculated. No "low-likelihood" indications could be identified. Elimination of the urograms obtained for any of the indications would not have been possible without simultaneously precluding detection of many diseased patients. The monetary cost of case-finding was low, and the efficacy of patient referral high.

Boston↗
PubMed1979

The barium enema; evidence for proper utilization.

A group of 1,041 patients was studied in an attempt to identify symptoms, signs, or laboratory findings (disease indicators) associated with either a high or low yield of abnormal barium enemas. A specific search was undertaken for subgroups with one or more statistically significant indicators of large bowel disease. If enemas were performed only for statistically significant indicators (fever, positive stool benzidine, rectal or abdominal mass, low hematocrit) or indicators of clinical importance (weight loss, constipation, diarrhea, etc.) only 13% of examinations would be eliminated. At the same time, however, 10% of patients with gastrointestinal disease would be missed.

Adult↗
PubMed1979

Time course of increased collateral arterial and venous endothelial cell turnover after renal artery stenosis in the rat.

We induced left renal artery stenosis in rats and studied collateral arterial formation by angiography, histology, and radioautography with tritiated thymidine. Endothelial cell turnover was estimated by radioautography with tritiated thymidine in the periureteric blood supply of 10 normal and 38 collateral-forming kidneys 1 to 100 days after stenosis. Periureteric arterial endothelial cell labeling showed a highly significant (P less than 0.005) increase, apparent within 1 day and gradually falling as the vessels grew, until a baseline was reached in 35 days. A smaller but statistically significant increase in the labeling index also was found in endothelial cells of the renal vein during the first week (P less than 0.01), and had a similar time course. A marked increase in epithelial cell labeling in the ureters draining the stenotic kidneys also was evident (P less than 0.005). Thus, collateral vessel development is characterized by active DNA synthesis in the cellular elements which is maximal during the first week. A humoral factor is implicated in the vascular response by the parallel proliferation of venous and uretic cellular elements that are unlikely to experience the biophysical forces, such as increased blood flow or tangential wall force, which might stimulate proliferation in ther arterial vessels.

Animals↗
PubMed1979

Circumaortic venous ring: incidence and significance.

A left circumaortic renal vein was found in 11% of 74 left renal venograms, an incidence similar to that at autopsy. Cavography proved to be an unsatisfactory method of demonstrating the renal veins. Prior knowledge of a venous ring is important when blood samples from the adrenal or renal veins are to be collected. When caval interruption is planned, a circumaortic venous ring may provide a fully developed collateral pathway immediately after surgery if the procedure is planned without awareness of its presence.

Abnormalities, Multiple↗
PubMed1979

Resting host and tumor perfusion as determinants of tumor vascular responses to norepinephrine.

Blood flow determinations and arteriograms were obtained in rat (Walker carcinoma) and rabbit (V2 carcinoma) liver tumors at rest and after norepinephrine administration. Resting tumor blood flow exceeded resting hepatic flow in both models, and both tumors responded with vasoconstriction and reduced blood flow. In tumors and the surrounding normal host tissue, the greater the perfusion prior to drug administration, the greater is the response (decrease in perfusion) to the vasoconstrictor. Although tumor perfusion decreased after vasoconstrictor, post-norepinephrine angiograms revealed an improved diagnostic image because of the enlarged but unresponsive tumor feeder vessels, persistent tumor blush, and simultaneous vasoconstriction in the normal liver. In these models, improved tumor visualization resulted even though a decrease in tumor blood flow had occurred. The angiographic image is related therefore to the lack of vasoconstriction in the tumor feeder vessel, which has, however, a decreased blood flow and the correspondingly greater volume of normally constricting hepatic arteries which results in a marked decrease in the background of vessels upon which the tumor image is superimposed.

Animals↗