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Biomedical subjects

Y Sultan

Publications and source records attributed to Y Sultan.

At least 145 records · Page 8Linked to original sources
PubMed1979

Predisposing factors to thrombosis in systemic lupus erythematosus: possible relation to endothelial cell damage.

We studied 28 patients with SLE, five of whom had had thrombotic episodes. Platelet function and coagulation and fibrinolytic studies were performed to determine whether any of these factors may predispose to thrombosis in SLE. An inhibitor of blood coagulation was detected in 12 patients, and von Willebrand's syndrome was observed in two others. The most striking findings which could be correlated with thromboembolic phenomena were the increase in VII R:WF and the absence of plasminogen activator release after venous occlusion. Both proteins are synthesized by the endothelial cell, and the abnormalities observed are possibly related to damage of the vascular endothelium by immune complexes observed in SLE.

Blood Platelets↗
PubMed1978

Platelet factor VIII-related antigen: studies in vivo after transfusion in patients with von Willebrand disease.

Four unrelated patients with a severe form of von Willebrand disease showed no detectable factor VIII-related antigen (VIIIR:AG) in either their plasma or their platelets. They received cryoprecipitate infusions, three patients in a single injection each and one every day for 9 days before and after surgery. Platelet VIIIR:Ag was studied at different times during and after transfusion using electroimmunoassay of platelet extracts and electron microscopy of the platelets incubated with anti-VIIIR:Ag antibodies coupled to peroxidase. No VIIIR-Ag was detected in or around the patients' platelets, although this antigen was detected in the circulating blood. These results that there was no VIIIR:Ag uptake from the plasma by the platelets and that platelet VIIIR:Ag came from megakaryocytes.

Adult↗
PubMed1978

[Disseminated intravascular coagulation (D.I.C.) and fibrinolysis in patients with acute leukemia (author's transl)].

Biological symptoms of D.I.C. were investigated in 43 patients with acute leukemia. Ten of them were found to be positive either at the onset or at the relapse of the disease and in some cases D.I.C. was triggered by chemotherapy. Among the ten positive cases 3 patients had an acute promyelocytic leukemia, 4 had an acute lymphoblastic leukemia, 2 a myeloblastic and 1 a monoblastic leukemia. D.I.C. was found either in patients with an hypercellular form of the disease or in patients with a normal or low white cell count. Symptoms of D.I.C. in acute leukemia must be systematically sought at the onset and during treatment by chemotherapy and treated with heparin and platelet transfusions as it is now admitted for acute promyelocytic leukemia.

Acute Disease↗
PubMed1977

Von Willebrand's disease: combined qualitative and quantitative abnormalities.

Studies of von Willebrand's disease typically show either a quantitative or a qualitative abnormality of the factor VIII/von Willebrand factor protein. In studies of five patients we found a combination of quantitative and qualitative defects. Quantitative abnormalities included decreased levels of procoagulant, antigen and von Willebrand factor activities in the plasma and in the column fractions of cryopercipitate from gel chromatography. Qualitative abnormalities included annormal migration or shape of the crossed antigen-antibody arcs, disproportionate reduction of von Willebrand factor in relation to antigen, altered gel elution patterns of procoagulant, and von Willebrand factor activities the negative carbohydrate stain of the VIII protein on polyacryl-amide-gel electrophoresis and, in two patients, a decreased sialic acid content of factor VIII protein. Our studies indicate that von Willebrand's disease comprises both quantitative and qualitative defects.

Blood Coagulation Factors↗
PubMed1977

Modifications of factor VIII related antigen in hemophiliacs with acute hepatitis and sub-clinical liver disease.

Modifications of Factor VIII related antigen (F, VIII R. A.) were investigated in three hemophilic patients during the course of post transfusion hepatitis. F. VIII R. A. was found to be elevated and correlated with the increase of the S.G.P.T. During the acute phase of the disease the Factor VIII related protein was tested for its ristocetin cofactor activity, its electrophoretic mobility on crossed antigen-antibody electrophoresis and its elution pattern on Sepharose 4B columns; all these properties proved to be abnormal. Liver function tests and F. VIII R. A. were measured in 36 multitransfused hemophiliacs. There was a significant increase of the F. VIII R. A. in the plasma of patients with abnormal liver function tests. Only a few of the multitransfused hemophiliacs had clinical symptoms of hepatitis, although 72% had elevated transaminase levels.

Acute Disease↗
PubMed1977

Modification of factor VIII complex properties in patients with liver disease.

Factor VIII procoagulant activity (VIII:C), factor VIII related antigen (VIIIR:AG), and the von Willebrand factor (VIII:WF) were measured in 19 patients with liver disease (8 cases of alcoholic cirrhosis and 11 with acute viral hepatitis). In both groups of patients the levels of VIII:C, VIIIR:AG, and VIIIR:WF were above normal or normal with mean values well above the normal range. VIIR:AG was also measured in the same patients by two-dimensional electrophoresis, and its biological properties were measured after purification by chromatography. By both methods the VIIIR: AG in the patients with liver disease differed from normal VIIIR:AG. In five of the patients with acute viral hepatitis, who were tested after they had recovered, the previously elevated levels of VIII:C, VIIIR:AG, and VIIIR:WF had dropped to normal limits and the qualitative abnormalities had disappeared.

Antigens↗
PubMed1976

Bleeding in renal failure: a possible cause.

Increased concentrations of factor VIII-related antigen (VIIIRA), factor VIII-procoagulant activity (VIIC), and decreased factor VII-von Willebrand activity (VIIIVWF) were found in the plasma of patients with chronic renal failure (CRF). This functional abnormality of the factor VII protein may partly explain the prolonged bleeding time commonly found in CRF. It was not improved by dialysis, but it was no longer found in patients with normally functioning grafted kidneys after the sixth month after transplantation. VIIIVWF levels remained decreased when compared with VIIIRA or VIIIC in transplanted patients undergoing acute reversible rejection soon after transplantation. Yet, not only VIIIC and VIIIRA but also VIIIVWF were greatly increased in patients with hyperacute irreversible rejection. Possibly a high VIIIVWF level in these patients is a thrombogenic factor.

Antigens↗
PubMed1976

[Reduction of Willebrand activity in patients with chronic kidney failure].

Decreased factor VIII von Willebrand activity in contrast with increased factor VIII procoagulant activity and increased concentrations of factor VIII related antigen, were found in the plasma of patients with chronic renal failure. This functional abnormality of the factor VIII protein is not improved by haemodialysis, but it is no longer found in patients with normally functioning grafted kidneys. It may at least partly explain the prolonged bleeding time commonly found in chronic renal failure.

Blood Coagulation Disorders↗
PubMed1976

Carbohydrate deficiency of the factor VIII/von Willebrand factor Protein in von Willebrand's disease variants.

Study of the normal human factor VIII/von Willebrand factor reveals a macromolecular glycoprotein composed of apparently identical subunits. This purified glycoprotein has procoagulant, antigen, and von Willebrand factor activities. In three patients with a variant of the von Willebrand's disease syndrome, their factor VIII/von Willebrand factor protein was present in normal amounts and had normal procoagulant and antigen activities; however, this protein was deficient in both carbohydrate and von Willebrand factor activity. The carbohydrate portion of the factor VIII/von Willebrand factor glycoprotein is of major importance in its interactions with platelets or the blood vessel wall, or both.

Antigens↗
PubMed1976

Immunologic studies in von Willebrand's disease: alteration of factor VIII/von Willebrand protein after transfusion with plasma concentrates in patients with von Willebrand's disease.

Two patients with a severe von Willebrand's disease characterized by no detectable factor VIII related antigen in their plasma received transfusions of cryoprecipitate. The bleeding time was corrected for a short period of time and returned to its pretransfusional value although the other parameters of the disease were still corrected. Electrophoretic and immunologic properties of factor VIII related antigen infused were determined serially after transfusion. Modifications of these properties occurred progressively after transfusion. The half disappearance time of F. VIII R.A. was determined and found to be considerably shorter than in hemophilic recipients. This study suggests an alteration in vivo of F. VIII R.A. infused into von Willebrand recipients.

Adult↗
PubMed1976

Electrophoretic heterogeneity of normal factor VIII/Von Willebrand protein, and abnormal electrophoretic mobility in patients with Von Willebrand's disease.

Crossed antigen-antibody electrophoresis was used to determine the electrophoretic properties of factor VIII/Von Willebrand (F. VIII/VW) protein in normal plasma using a specific rabbit antiserum against purified human factor VIII. The electrohoretic patterns in seven patients with severe Von Willebrand's disease in two different families were studied. In these patients the prolonged bleeding time was related to a functionally abnormal F. VIII/VW protein which was unable to induce platelet aggregation in presence of ristocetin. F. VIII/VW protein had an increased electrophoretic mobility in all the patients. The electrophoretic pattern was similar in different members of the same family but differed from one family to the other. Plasma samples collected after transfusion of normal cryoprecipitate to one member of the first family showed an increasing amount of F. VIII/VW protein, but even one hour after transfusion only one peak migration in an abnormal position was found. However, when mixed in vitro with normal plasma, the plasmas of the same patient showed two peaks, one in position of normal F. VIII/VW protein and one with increased electrophoretic mobility. These results suggest that normal F. VIII/VW protein transfused to recipients with Von Willebrand's disease synthesizing a functionally deficient factor undergoes a rapid alteration.

Antigen-Antibody Reactions↗