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Biomedical subjects

D Frommel

Publications and source records attributed to D Frommel.

13 recordsLinked to original sources
PubMed1979

Selective absence of large forms of factor VIII/von Willebrand factor in acquired von Willebrand's syndrome. Response to transfusion.

A previously healthy elderly man with mucocutaneous bleeding was found to have a benign monoclonal IgG gammapathy associated with criteria for severe von Willebrand disease (Factor VIII procoagulant activity, Factor-VIII-related antigen, and ristocetin cofactor activity, less than 10% of normal). Associated qualitative abnormalities of factor VIII/von Willebrand factor were demonstrated by radiocrossed immunoelectrophoresis and immunoradiometric assay. The late clinical onset and negative family history are in favor of an acquired form of vWD. The monoclonal gammapathy and abnormalities of factor VIII/von Willebrand factor have been stable over a 10-yr period. No inhibitor to Factor VIII procoagulant activity, ristocetin cofactor activity, or Factor-VIII-related antigen could be demonstrated. Following transfusion of cryoprecipitate (with a normal cross immunoelectrophoretic pattern), there was a rapid removal of the large forms of Factor.-VIII-related antigen, paralleled by a decay of ristocetin cofactor activity. The transfusion study of this patient with acquired von Willebrand disease type II (variant of von Willebrand disease) serves to emphasize the relationship between polydispersity of Factor VIII/von Willebrand Factor and functional heterogeneity.

Adult↗
PubMed1978

Preparation of single cell suspension from rat liver. A simple method designed for immunologic studies.

Single cell suspensions from rat liver were prepared by mean of a 10 min. in vivo liver perfusion with an isotonic solution. This solution was devoid of calcium but contained 27 mM of sodium citrate and 1% of bovine serum albumin. The liver cells were dissociated over chromium nickel screen in presence of 0.8 mM of calcium and 0.25 M of saccharose; they were further separated by gravity sedimentation for 10 min. The dissociated cells, when incubated in Waymouth's medium enriched with 15% of heat-inactivated horse serum and 1% of BSA, actively synthetized urea and proteins. They also incorporated [3H] thymidine. Isolated hepatocytes, obtained without resorting to extraneous enzymes, conform to the conditions required for the study of cell surface receptors involved in immunologic recognition mechanisms.

Animals↗
PubMed1976

Failure of immunosuppression in a severe haemophilia B patient with specific antibody.

Prevention of a secondary response to factor IX by cyclophosphamide was attempted in an 11 year old patient with severe Christmas disease. An antibody to factor IX had been present for 4 years before immunosuppressive therapy was tried. Despite profound lymphopenia, synthesis of factor IX antibody was not depressed. The difficulties of modifying the anamnestic response to factor IX by chemical immunosuppression may be as real as has been reported for factor VIII in classical haemophilia.

Antibodies↗
PubMed1976

Antibodies to factor VIII. V. Patterns of immune response to factor VIII in hemophilia A.

The natural history of factor VIII antibodies was studied in 20 severe, multitransfused hemophiliacs. Two patterns of humoral immune reactivity were observed. In one group of ten, who developed antibodies after an average of 22 cumulative exposure days to factor VIII, the antibody titers increased after each antigenic stimulation or persisted for years in the absence of transfusion. These patients were designated as high-responding hemophiliacs. In the second group of ten patients, the factor VIII neutralizing activity appeared after a longer exposure period (48 days). Antibody titers remained low, and there was no significant difference in individual titers before and 8--20 days following transfusion. Antibody affinity did not increase after renewed antigenic challenge. This pattern characterized low-responding hemophiliacs. The latter group of patients benefited from repeated placement therapy required by the clinical situation.

Antibodies↗
PubMed1975

Performances of an artificial reagent for the one-stage factor IX assay.

A mixture of adsorbed normal human plasma and chicken plasma was prepared as reagent for factor IX measurement using a one-stage method. The substrate was found to be specific for factor IX. Its performances tested on samples displaying factor IX activity ranging from less than 1%-2,000% compared favorably with those obtained when using the plasma of severe haemophilia B patients as substrate.

Animals↗
PubMed1975

Severe viral hepatitis type B in infancy;.

Fourteen infants aged from 2 to 5 months were admitted to hospital with acute viral hepatitis. Their clinical presentation ranged from severe disease to fulminant hepatitis. In all patients the prothrombin-time was 10% or less of normal and serum glutamic pyruvic transaminase and bilirubin were increased. In eight cases liver-biopsy specimens were obtained during liver failure and showed a widespread necrosis without inflammatory cells. Hepatitis-B-surface antigen (HBSAg) and antibody (HBSAb) were sought by several techniques, including passive haemagglutination and radioimmunoassay. Hepatitis was associated with hepatitis-B virus in eleven out of fourteen patients as judged by the detection of HBSAg and/or a secondary rise in HBSAb. In eight cases, the infants had received blood-derivatives in the neonatal period. The mothers of five of the remaining cases were found to be chronic carriers of HBSAg. Despite intensive supportive therapy, including repeated exchange transfusions and administration of anti-HBS gamma-globulins (six cases), eight patients died. These cases demonstrate that severe or fulminant type-B hepatitis can develop in infants, who are capable of completely eliminating the hepatitis-B virus. They also suggest that severe hepatitis can result from maternal contamination.

Alanine Transaminase↗
PubMed1975

Is the determination of AHF activity feasible for individual cryoprecipitates?

A method is described in which the factor VIII (AHF) activity of 40 individual cryoprecipitates can be determined within 4 h. The reagents employed do not require plasma congenitally deficient in factor VIII. The preparation of cryoprecipitates with known biological activity should result in a more rational use of this type of factor VIII concentrate.

Blood Banks↗
PubMedDate not supplied

Receptor for the Fc portion of IgG on the plasma membrane of the hepatocyte.

Applying the immune rosette assay to suspensions of isolated liver cells, 30 to 50 % of hepatocytes obtained from rabbit liver from rosettes with sheep erythrocytes sensitized with IgG. Rosette formation can be inhibited by preincubation of the hepatocytes with aggregated IgG. The interaction between hepatocytes and IgG is not species-specific. Pretreatment of hepatocytes with F(ab')2 fragments of antibody with anti-IgG activity does not interfer with rosette formation. No binding occurs with erythrocytes coated with F(ab')2 fragments, IgM or IgM + complement. These membrane receptors for Fc gamma share many properties with those recognized on macrophagic cells and B lymphocytes; it seems however that on liver cell surface their density and/or their affinity for IgG are inferior to those of mesodermderived cells.

Animals↗