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Biomedical subjects

J I Spector

Publications and source records attributed to J I Spector.

26 records · Page 2Linked to original sources
PubMed1975

Coagulation changes in baboons during acute experimental hemoglobinemia and dextran infusion.

Evidence of disseminated intravascular coagulation (DIC) was dought in normal baboons infused with autologous hemolyzed whole blood, preceded or followed by infusion of dextran (molecular weight, 70,000). Mean peak plasma hemoglobin following a rapid single injection was 370 mg/100 ml in 2 animals and 1,236 mg/100 ml in 1 animal, while levels during continuous 5 hour infusion in 2 animals averaged 326 and 474 mg/100 ml, respectively. Dextran infusion immediately preceded hemoglobin injection in 2 baboons and followed hemoglobin injection by 1 1/2 and 2 1/2 hours, respectively, in 2 baboons. Coagulation studies showed a moderate although significant fall in platelet count with prolongation of the partial thromboplastin time following hemoglobin infusion, and shortening of the thrombin time after dextran. Fibrin degradation products developed in four of five experiments after hemolysate injection. The induction of acute experimental hemoglobinemia results, therefore, in the development of coagulation changes consistent with milk DIC. Preliminary infusion of dextran (molecular weight, 70,000) may facilitate this response by either initiating the development or impeding the clearance of fibrin degradation products.

Acute Disease↗
PubMed1974

Coagulation studies and correlative histology during experimental hemoglobinemia in rabbits.

Evidence of disseminated intravascular coagulation (DIC) was sought in New Zealand white rabbits infused with autologous, hemolyzed whole blood. Hemoglobinemia was induced in 17 rabbits by rapid intravenous injection of frozenthawed whole blood. Three dose regimens yielded mean peak plasma hemoglobin concentrations of 325, 615 and 860 mg/100 ml respectively (range 260 to 1050 mg/100 ml). Eleven control animals were infused with autologous, nonhemolyzed whole blood in similar doses. Rabbits were killed at either 15, 60, 120 or 180 minutes following infusion and multiple organ biopsies obtained immediately post-mortem. Coagulation studies demonstrated no significant alterations in prothrombin time, partial thromboplastin time, thrombin time or fibrinogen. Fibrin degradation products were not found. Histologic examination of lung, heart, liver, spleen and kidney revealed no fibrin deposition, thrombus formation or other abnormalities. We conclude from our study that induction of brief, experimental hemoglobinemia in New Zealand white rabbits, utilizing moderately large doses of autologous, hemolyzed whole blood, does not result in the development of DIC.

Animals↗
PubMedDate not supplied

Viability and function of platelets frozen at 2 to 3 C per minute with 4 or 5 per cent DMSO and stored at -80 C for 8 months.

Each of 15 healthy male volunteers was treated with 650 mg of aspirin 24 hours before the autologous transfusion of one unit of freeze-preserved platelets. Freeze-thaw-wash recovery values in vitro, viability and function in vivo, and the bleeding time and platelet aggregation response were measured. The platelets were frozen with 4 or 5 per cent dimethylsulfoxide (DMSO) at an overall rate of 2 to 3 C per minute and were stored at -80 C in a mechanical freezer for up to eight months. They were washed by dilution/centrifugation. The mean recovery in vitro of platelets frozen with 4 per cent DMSO was 76+/-16%; the value was 64+/-16% for platelets frozen with 5% DMSO. The mean in vivo 51Cr recovery of autologous platelets frozen with 4% DMSO was 34+/-6%, and for platelets frozen with 5% DMSO it was 33+/-7%. In both groups the platelet lifespan was normal. There was a significant reduction in bleeding time after the transfusion of a single unit of autologous platelets preserved with either 4 or 5% DMSO, but no improvement in the aspirin-induced platelet aggregation pattern.

Aspirin↗
PubMedDate not supplied

Oxygen consumption, platelet aggregation and release reactions in platelets freeze-preserved with dimethylsulfoxide.

Platelets were frozen with 4% or 5% DMSO at an overall rate of 2 to 3 C per minute and were stored at -80 C for as long as 10 months. They were washed with DMSO-plasma and acid-citrate-dextrose (ACD) solutions and were stored in 30 ml of autologous plasma at room temperature for about three hours before transfusion. Measurements were made of oxygen consumption, platelet aggregation and release reaction, platelet factor-3 and-4 activities, and platelet response to hypotonic stress. Platelet basal and latex stimulated oxygen consumption were found to be significantly impaired; platelet aggregation response to ADP, epinephrine, and collagen were decreased; platelet ATP and ADP content and release reactions were decreased; platelet antiheparin activity (platelet factor-4 level) was decreased; and the platelet response to hypotonic stress was impaired. What the results of these in vitro tests mean in relation to in vivo survival and hemostatic function of preserved platelets was not established.

Adenosine Diphosphate↗
PubMedDate not supplied

Ultrastructural alterations and phagocytic function of cryopreserved platelets.

Fresh human platelets and platelets cryopreserved in 4% dimethylsulfoxide were examined ultrastructurally before and after incubation in a suspension of latex particles. Cryopreserved platelets had fewer discoid forms than fresh platelets. The cryopreserved platelets had many sphered platelets containing an increased number of vacuoles; the sphered platelets were more electron-lucent margination and pallor of organelles. Phagocytosis of latex into vacuoles was markedly impaired in the cryopreserved platelets. The morphologic alterations suggested that the freezing, thawing, and washing procedures reduced the functional activity of platelets.

Blood Platelets↗
PubMedDate not supplied

Therapeutic transfusions of previously frozen washed human platelets.

The platelets used in this study were collected by serial centrifugation, and within four hours of collection were frozen with 5% dimethylsulfoxide (DMSO) at an overall rate of 2 to 3 C per minute by storage in a mechanical refrigerator at -80 C. The frozen platelets were stored for four to ten weeks before thawing and washing. After washing, the units were kept at room temperature for six to eight hours before transfusion. The units were pooled, and an average of eight units was given to each of four patients, with a range of three to 14 units per transfusion. In vitro recovery after washing was about 65 per cent and in vivo recovery of the 51chromium labeled (51Cr) platelets was about 35 per cent. The infusion of these previously frozen washed platelets corrected prolonged bleeding times in patients. The homologous platelets were transfused along with other blood products to treat patients with hematologic disorders. The circulation and function of the donor platelets were influenced by compatibility of the platelets, the quality of platelet preservation and the patient's disease state.

ABO Blood-Group System↗