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Biomedical subjects

R K Smiley

Publications and source records attributed to R K Smiley.

18 recordsLinked to original sources
PubMed1991

Unrelated bone marrow transplantation in Canada, the national experience.

The Canadian Unrelated Bone Marrow Donor Registry (UBMDR) of the Canadian Red Cross Society (CRCS) Blood Transfusion Service (BTS) was officially funded as of April 1, 1989 for an initial three year period with a mandate to recruit 50,000 unrelated bone marrow donors and conduct the search activities for unrelated bone marrow donors worldwide on behalf of Canadian patients (1). All provinces of Canada agreed to fund the Registry and it was unanimously adopted to locate the Canadian National Coordinating Centre (CNCC) of the Registry in Vancouver. Since February of 1988, 64 unrelated bone marrow transplants have been carried out in Canada. Over half of the unrelated donors have come from other countries. Canada has established working relationships with the United States, the United Kingdom and France. Recruitment of unrelated bone marrow donors is now established in twelve Canadian cities with more to follow. It is anticipated that the size of the registries world wide will continue to increase, that their ethnic makeup will become diversified and that the indications for unrelated bone marrow transplantation will broaden in the years to come.

Bone Marrow Transplantation↗
PubMed1989

Studies on the prolonged bleeding time in von Willebrand's disease.

Ten studies of the effect of cryoprecipitate infusion in four patients with von Willebrand's Disease (vWD) are reported. The doses studied (4, 8 and in one case 10 bags of cryoprecipitate) were based on previous reports of correction of the bleeding time (BT) with such doses. A modest shortening of the BT was observed in only 2 studies and complete correction of the BT at 1 and 4 hours was observed in only one study. This latter result could not be reproduced in a subsequent study of the same patient. In all cases, the von Willebrand factor antigen (vWF:Ag) multimer patterns were normal in the infused cryoprecipitate and in the recipients' plasma post infusion with the presence of high molecular weight multimers demonstrated in all samples. These results contradict earlier reports of the effect on the BT of similar doses of cryoprecipitate and suggest that the presence of the high molecular weight forms of vWF:Ag does not necessarily correlate with the presence of the factor which corrects the bleeding time.

Adult↗
PubMed1989

Epinephrine and dDAVP administration in patients with congenital nephrogenic diabetes insipidus. Evidence for a pre-cyclic AMP V2 receptor defective mechanism.

We recently showed that the administration of the antidiuretic V2 specific agonist, 1-desamino[8-D-arginine]vasopressin (dDAVP), to seven male patients with congenital nephrogenic diabetes insipidus (CNDI) did not cause a decrease in blood pressure nor an increase in plasma renin activity or factor VIIIc or von Willebrand factor release. In normal subjects, plasma renin activity, coagulation factors and plasma cyclic AMP are stimulated not only by dDAVP but also by the administration of epinephrine. In the present study, we measured tissue plasminogen activator (activity and antigenicity), von Willebrand factor multimers, plasma and urinary cyclic AMP concentrations following dDAVP or epinephrine administration. We infused epinephrine into three male patients with CNDI. Factor VIIIc and tissue plasminogen activator augmented by 75 to 100% and von Willebrand Factor multimers were increased; plasma renin activity and plasma cyclic AMP concentration increased by 200%. None of these values changed when the same subjects as well as eleven other male patients with CNDI received dDAVP. Furthermore, dDAVP administration increased plasma cyclic AMP concentrations in normal subjects, but not in 14 male patients with CNDI. These results demonstrate the specificity of the extrarenal V2 receptor defect expressed in our patients. The lack of a plasma cyclic AMP response to the administration of dDAVP would suggest an altered pre-cyclic AMP stimulation mechanism.

Adult↗
PubMed1988

An antibody to platelet membrane antigen associated with thrombotic events in essential thrombocythemia.

A 71-year-old man with essential thrombocythemia presented with acute onset of thrombosis in his fingers. The platelet count at presentation was 752 x 10(9)/liter, and his PTT was within the normal range. Platelet aggregation was normal in response to ADP, decreased to epinephrine, and absent to collagen, with the patient receiving 1.2 g aspirin/day. Plasma vWF:Ag was 158 U/dl, VIII:C was 150 U/dl, and the vWF:Ag multimer pattern was normal. HLA antibodies were not detected in his serum, and the platelet-associated IgG was normal at 3.9 fg/platelet. Incubation of normal, unactivated platelets with the patient's plasma did not result in agglutination of the platelets. However, a serum antibody reacting against a platelet antigen with an apparent molecular weight of 45,000 could be demonstrated by Western blotting. This antibody also reacted with endothelial cells. The reactive pattern was similar to that of commercially obtained actin; the serum antibody could be removed by preincubation with actin. Platelet-plasmapheresis was carried out daily for 10 days, after which the serum still reacted weakly with the platelet antigen. By day 20, the band could still be identified on the electroblot, but 2 weeks later no band could be seen. Similar assay of sera from six other patients with myeloproliferative disorders and comparable thrombocytosis but without thrombotic manifestations did not show any such reactions. The data suggest a correlation between the presence of an antibody possibly directed against platelet and/or endothelial cell actin and the vascular events in this patient with essential thrombocythemia.

Aged↗
PubMed1987

Registry of unrelated bone marrow donors.

Reports of successful transplantation of bone marrow obtained from unrelated donors who were histocompatibility leukocyte antigen (HLA) identical prompted the Canadian Red Cross Blood Transfusion Service in Ottawa to assess the possibility of developing a bone marrow donor registry in Canada. We sent a pamphlet that explained the program to 1568 people who had undergone apheresis and asked them to reply, stating their interest. At the same time the pamphlets and a poster were placed in the blood donor clinic. We received 1232 replies (78.6%) from the apheresis donors, 838 (68.0%) of which indicated a willingness to attend information sessions. Of the 7158 people who gave blood during the 3-month study period, 225 (3.1%) were interested. At the time this paper was written 47 information sessions had been held, and 721 people had attended, 624 (86.5%) of whom had signed a consent form. This indicates a clear interest in a bone marrow donation program. We believe that the ethical issues are overcome by requesting the donation before identification of any patient. From our experience a national registry of unrelated donors seems feasible, and steps are being taken to implement such a program.

Blood Component Removal↗
PubMed1983

Analysis of contaminants in factor VIII preparations administered to patients with hemophilia.

Cryoprecipitate and the more purified factor VIII concentrates are all heterogeneous preparations that contain not only a high concentration of factor VIII but also various other materials, some of which might be injurious, causing liver damage after long-term exposure. The efficiency of three standard cryoprecipitate filters, two microaggregate filters and the appropriate factor VIII concentrate filters in reducing the amount of particulate matter delivered to the patient was assessed. Filtration of cryoprecipitate through the standard filters removed less than 20% of the contaminating microaggregates and very few of the large number of intact platelets, although the total dose of factor VIII was delivered. Microaggregate filters were no better in reducing the platelet contamination, although the total number of particles delivered was halved. However, 25% of the factor VIII was retained in the bed volume of the filter. The concentrate preparations also contained significant amounts of particulate matter that was unrelated to factor VIII and was not removed following filtration through the designated filter. These findings indicate that a new filter should be developed for administration of factor VIII concentrate that would remove the particulate matter while delivering all of the factor VIII to the patient.

Diethylhexyl Phthalate↗
PubMed1979

Student performance in internal medicine: the effect of previous clerkship experience.

To test the assumption that students who have completed other clerkships are likely to perform better in internal medicine, the authors undertook a prospective study of 160 senior students from two classes. Groups of students with little or no senior clerkship experience before their internal medicine clerkship were compared with groups of students who had extensive clerkship experience in disciplines other than medicine. Groups were compared with respect to ward-performance scores and scores on identical multiple-choice examinations. Neither ward-performance nor multiple-choice scores revealed differences attributable to previous clerkship experience. It is concluded that despite areas of instruction and experience which overlap between medicine and other disciplines, previous clerkship experience apparently does not have a beneficial effect on student performance in internal medicine, as measured by these two commonly used methods of evaluation.

Analysis of Variance↗
PubMed1977

HLA and hereditary spherocytosis.

The HLA types of two families with hereditary spherocytosis (HS) suggest that the HS gene(s) may be linked with the HLA locus. If sustantiated by further family studies, this linkage would place HS on chromosome 6.

Child, Preschool↗
PubMed1968

Anemia.

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Anemia↗
PubMed1967

Experience with the use of frozen blood.

The long-term preservation of blood by conventional methods, i.e. beyond five to six weeks, has not progressed significantly since World War I. In the past 10 years, freezing techniques have opened new avenues in this field; it is now possible to store blood for periods of five years or more. Several techniques have been developed, either using liquid nitrogen and the rapid-freezing principle or using "cryophylactic agents" such as glycerol, where the rate of freezing is unimportant and the blood is kept at -85 degrees C. The latter methods require washing of the blood before transfusion to remove the intracellular glycerol and thus avoid post-transfusion osmotic hemolysis. At the National Defence Medical Centre in Ottawa, the Huggins' technique of freeze-preservation of blood has been adopted. This novel method of deglycerolization is based on the "reversible agglomeration" of erythrocytes in electrolyte-free sugar solutions. The in vitro and in vivo studies have yielded satisfactory results, and certain applications of the method are discussed.

Adolescent↗