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Biomedical subjects

J D Olson

Publications and source records attributed to J D Olson.

100 records · Page 6Linked to original sources
PubMed1975

Evaluation of ristocetin-Willebrand factor assay and ristocetin-induced platelet aggregation.

Normal subjects, patients with various bleeding disorders, and patients with von Willebrand's disease were studied. All patients with von Willebrand's disease had decreased levels of ristocetin-Willebrand factor (range, 0 to 41%) as compared with all other subjects (range, 79 to 202%). Ristocetin-induced platelet aggregation of platelet-rich plasma was abnormal in all patients with von Willebrand's disease tested, and it was possible to correct this abnormal response by addition of normal platelet-poor plasma. Abnormal ristocetin-induced platelet aggregation was seen in patients with intrinsic platelet disorders or, on some occasions, in normal patients who had ingested aspirin. Ristocetin-induced platelet aggregation is not diagnostic, but it may be useful as a simple screening test for patients with possible von Willebrand's disease. In conjunction with other tests, the assay for ristocetin-Willebrand factor will be useful in diagnosis and evaluation of these patients.

Anticoagulants↗
PubMed1975

Liver lipid content of twenty varieties of laying hens from three confinement systems.

Average liver lipid values were determined for 20 varieties of 71-week old laying hens managed in 3 confinement systems of the 1972-73 North Carolina Random Sample Laying Test. There were highly significant differences in liver lipid atrributable to variety, to confinement system, and a significant variety X system interaction. Four varieties had consistently high and five had consistently low liver lipid values in all 3 confinement systems. Varietymeans ranged from 25.8 to 49.0% liver lipid on a dry weight basis. Hens confined 2/cage had slight but significantly higher liver lipid than hens 7/cage or in floor pens. Liver lipid was positively correlated with body weight in hens 2/cage and in floor pens. There were no significant correlations of liver lipid with egg production or mortality. A frequency distribution of individual liver lipid values revealed a continuous distribution from 15.4 to 65.4with a pronounced skew to the right of the mean of 38.2%. Neither a fatty liver syndrome nor liver hemorrhage syndrome was reported for any of the flocks during the laying year. The normal range of liver lipid values for hens 71 weeks of age appears to be between 25 and 49 g. of lipid per 100 g. of dry liver weight.

Animals↗
PubMedDate not supplied

Exclusion of atrial thrombus by transesophageal echocardiography.

To determine whether transesophageal echocardiography (TEE) is useful in ruling out the presence of atrial thrombus, we performed TEE in 20 patients immediately before valve replacement or valve repair and within 3 days of an autopsy in one patient. Mitral stenosis was the predominant lesion in three patients, mitral regurgitation was seen in 11 patients, five patients had mitral prosthesis malfunction, one patient had a tricuspid prosthesis malfunction, and one patient had aortic stenosis. Eight patients were in atrial fibrillation. Four patients demonstrated spontaneous contrast in the associated atria. Nine patients were receiving oral anticoagulation. Mean left atrial diameter was 5.3 +/- 1.3 mm. TEE revealed no evidence for atrial thrombus in 18 of the 21 patients; this finding was confirmed by careful inspection of the atria including the appendages. TEE demonstrated a left atrial thrombus in two patients and a right atrial thrombus in another (confirmed at the time of surgery or at autopsy). In all cases transthoracic echocardiography was negative. Our data suggest that TEE is useful in ruling out atrial thrombus, and therefore may be a useful test preceding interventions associated with an increased risk of embolism from the atria such as cardioversion, mitral valvuloplasty, or valve replacement.

Adult↗
PubMedDate not supplied

White cell fragmentation after therapeutic leukapheresis for acute leukemia.

A 70-year-old woman with newly diagnosed acute nonlymphocytic leukemia (FAB M5) underwent therapeutic leukapheresis because of a white cell count (WBC) of 144 X 10(9) per I and clinical evidence of leukostasis. A peripheral blood film taken immediately after leukapheresis showed numerous cytoplasmic and nuclear fragments. The patient's clinical course thereafter was significantly compromised by disseminated intravascular coagulation with a severe bleeding diathesis, renal failure, and respiratory failure that led to her death. This case illustrates that therapeutic leukapheresis for elevated WBC in patients with acute leukemia may result in leukocyte fragmentation and possible intravascular coagulation.

Acute Disease↗