Annals of clinical and laboratory science
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Ann. Clin. Lab. Sci. · Jan 1995
Comparative StudyInfectious disease markers in various groups of donors.
A number of studies have commented on the inadvisability of transfusing unused blood given by autologous and directed donors to patients other than those for whom the blood was originally given (crossing over). It has been stated that these bloods are dangerous and should not be used for allogeneic transfusion. ⋯ Therefore, the "dangerous" donor is actually more likely a first time donor. Following this reasoning, the use of all blood from first time donors should be suspect.
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Ann. Clin. Lab. Sci. · Jan 1993
Alterations in von Willebrand factor antigen in premature infants with respiratory distress syndrome and chronic lung disease.
Elevated levels of von Willebrand Factor Antigen (vWF:Ag) may occur in the presence of endothelial injury, a component in the pathology of acute pulmonary insufficiency. The vWF:Ag levels were examined in 13 well infants (controls) and 20 infants with respiratory distress syndrome (RDS), nine of whom developed bronchopulmonary dysplasia (BPD). All infants were very low birth weight (730 to 1500 g) and premature (25 to 34 weeks estimated gestational age). ⋯ Visual examination of vWF multimer patterns revealed absence of unusually large vWF multimers and triplet patterns suggestive of increased proteolytic degradation of von Willebrand factor. However, densitometer scanning revealed that samples with higher vWF:Ag levels (> 200 percent) had increased amounts of moderate to smaller sized multimers, regardless of presence or absence of BPD. It is our conclusion that von Willebrand factor antigen levels are nonspecifically elevated in premature infants and that chronic lung disease is associated with even higher plasma values, possibly owing to pulmonary endothelial injury.
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Ann. Clin. Lab. Sci. · Jan 1992
Angiotensin-1-converting enzyme activity as index of pulmonary damage in thermal injury with or without smoke inhalation.
Serum angiotensin-converting enzyme (ACE) activity, plasma renin activity (PRA), and serum aldosterone levels were measured up to four weeks in a population of adults exposed to thermal injury, with or without concomitant exposure to smoke inhalation. In 10 patients, plasma levels of angiotensin-2 and ACE activity in bronchial lavage were also evaluated. Patients with severe burn injury had a significant decline of serum ACE activity while the concentrations of aldosterone and PRA were markedly elevated. ⋯ In conclusion, serum ACE activity decreases in burn patients according to the severity of the cutaneous burn; smoke inhalation influences serum levels of the enzyme with concentration values opposite to the low ones present in cutaneous burn. Finally, the enzyme activity has an independent pattern from that of the other components of the renin angiotensin aldosterone system. The evaluation of ACE activity may be a marker of pulmonary damage in smoke inhalation.
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Ann. Clin. Lab. Sci. · Sep 1991
A study of aspirin induced changes in bleeding time, platelet aggregation, and Sonoclot coagulation analysis in humans.
The purpose of this study was to determine whether or not a newer test of platelet function, Sonoclot coagulation analysis, can identify the patients who develop significant prolongation of bleeding time after aspirin ingestion. Template bleeding time, platelet aggregation in response to arachidonic acid, collagen, epinephrine, adenosine diphosphate, and ristocetin, and Sonoclot coagulation analysis were performed before and after ingestion of aspirin in 22 adult volunteers. Mean bleeding time increased from 5.32 +/- 2.16 min to 7.34 +/- 2.1 min, but remained within normal range (2.5 to 9 min). ⋯ Five patients with known platelet function disorders and prolonged bleeding times (mean = 18.5 min, range 14 to 22) without any other coagulation abnormalities were also studied. In four of these patients who had normal platelet count, Sonoclot graphs were morphologically similar to those in the volunteers with normal bleeding times, but in one patient with thrombocytopenia, morphology was altered. It is our conclusion that Sonoclot coagulation analysis is unlikely to identify patients with prolonged bleeding time in whom platelet count and other coagulation factors are normal.
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Ann. Clin. Lab. Sci. · May 1989
ReviewVon Willebrand factor and von Willebrand's disease: a complex protein and a complex disease.
Von Willebrand factor is a complex protein which is important in several ways for normal hemostasis. Von Willebrand's disease results when there is either a quantitative or qualitative disorder of von Willebrand factor. In this review, the structure and function of von Willebrand factor are discussed. Additionally, the current laboratory and clinical classification of von Willebrand's disease and closely related variants are outlined.