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Biomedical subjects

H A Perkins

Publications and source records attributed to H A Perkins.

At least 55 records · Page 3Linked to original sources
PubMed1980

Problems in paternity testing. Subtypes of AB.

Paternity test results demonstrated that a child of type A1 has a mother who types as an A2B; the putative father is type O. According to the recent AMA-ABA joint report, these results prove nonpaternity. All other erythrocytic and HLA typing indicated a high probability that the putative father was the biologic father. Since the expression of the A1 gene may be weakened on the erythrocytes of a type AB person, the possibility that the mother carried an A1 gene was considered. Review of published data reveals that in black persons there appears to be an excess of type A2B and a deficiency of type A1B compared with the numbers expected from gene frequencies. It is possible that as many as one of five black persons with A1 and B genes has an A2B phenotype.

ABO Blood-Group System↗
PubMed1980

Possible gonadal mosaicism in a family with hemoglobin Köln.

A brother and sister were the first members of a family to possess hemoglobin Köln (alpha 2 beta 2(98) Val leads to Met). Studies of these siblings and their parents strongly indicated that the anomaly had arisen by spontaneous mutation. Gonadal mosaicism of one of the parents offers the best explanation for the appearance of a spontaneous mutation in multiple members of a sibship.

Adult↗
PubMed1979

A simple enzyme-immunoassay (EIA) test for factor VIII-related antigen (VIIIAGN).

An enzyme immunoassay (EIA) system has been developed to measure factor VIII-related antigen (VIIIAGN). This assay gives similar results to the commonly used Laurell electroimmunodiffusion (EID) assay for VIIIAGN as shown by comparison of both techniques with samples from healthy controls, patients with hemophilia A, and patients with von Willebrand's disease. The assay also has a greater precision than the EID technique as demonstrated by multiple assays of aliquots of a single sample. The use of this EIA test for VIIIAGN is simple and employs inexpensive reagents and equipment. The use of expensive antisera is minimized. EIA for VIIIAGN has the advantage of increased sensitivity compared to Laurell EIA.

Animals↗
PubMed1979

Cryoprecipitate as a reliable source of fibrinogen replacement.

The recent withdrawal of commercial fibrinogen from the market makes alternate sources most important. Although it has been previously reported that single-donor cryoprecipitate contains appreciable amounts of fibrinogen, most clinicians need to be reminded of the reliability of cryoprecipitate for replacement of both fibrinogen and factor VIII. We assayed fibrinogen from 88 bags of cryoprecipitate prepared by five different blood banks in California and Oregon; we found that the average bag of cryoprecipitate contains at least 250 mg of fibrinogen depending on the volume of plasma processed. Cryoprecipitate was found to be a poor source of factors II, V, IX, X, XI, and XII.

Afibrinogenemia↗
PubMed1979

Re-evaluation of plasmas from patients previously diagnosed as having von Willebrand's disease with the factor VIII-related antigen and ristocetin cofactor assay.

Diagnosis of deficiencies of coagulation factor VIII can be difficult to establish in some cases. The use of the factor VIII-related antigen and the use of the ristocetin cofactor assays have increased the reliability of diagnosis of factor VIII deficiency in patients with hemophilia A or von Willebrand's disease, and in carriers of hemophilia A. The authors re-evaluated samples, from frozen storage, of blood from patients previously diagnosed as having von Willebrand's disease. This diagnosis was based on clinical history, family history, bleeding time, factor VIII procoagulant activity, and response to ristocetin in platelet-aggregation studies. Eleven cases were studied by the review of previously obtained data and the addition of the factor VIII-related antigen and ristocetin-cofactor assays. In two of eleven cases, the diagnosis was changed to possible hemophilia A carrier state.

Adolescent↗
PubMed1979

Bovine plasma as a reference standard for the factor VIII assay.

Definition of one unit of factor VIII procoagulant activity may be imprecise, for a number of reasons. Levels in individual normal plasmas differ sufficiently that small pools do not have equivalent activities. Large pools cannot be prepared without loss of activity because of the lability of factor VIII. Human factor VIII may not be stable at --20 C. Lyophilized standards may vary in activity because of difficulties in dissolving the materials. The authors have prepared standards that are stable at --20 C for years using beef plasma diluted in outdated human blood bank plasma. The level of activity of this working standard is verified by repeated assays of lyophilized national standards and of small pools of normal donor plasma. The standard is equally applicable to one- or two-stage assays for factor VIII.

Animals↗
PubMed1979

Tn polyagglutination preceding acute leukemia.

Tn polyagglutination (persistent mixed-field polyagglutination) was detected in the blood of a 66-yr-old male laborer at the time of a splenectomy for life-threatening thrombocytopenia. Confirmation that the polyagglutination was caused by Tn activation was established by the use of lectins, by failure of the patient's red cells to react with sera from other patients with Tn polyagglutination, by weak aggregation with polybrene, by low red cell sialic acid levels, and by the persistence of polyagglutination over several years of testing. Two years after the discovery of the Tn polyagglutination, the patient developed acute myelomonocytic leukemia. Vigorous chemotherapy regimens resulted in clinical remission of the leukemia and the Tn polyagglutination. This report describes the first known case of Tn polyagglutination preceding the development of acute myelogenous leukemia.

Aged↗
PubMed1978

Immunologic factors determining survival of cadaver-kidney transplants. The effect of HLA serotyping, cytotoxic antibodies and blood transfusions on graft survival.

We assessed immunologic factors determining graft survival in 510 recipients of primary cadaver allografts at one center. The degree of HLA match grade did not directly affect graft survival (54 per cent in no-antigen match, and 42 per cent in three-antigen match, at two years). There was no correlation between the HLA match grade and the degree of stimulation of the mixed lymphocyte culture. Patients receiving more than five blood transfusions had a significantly better graft survival than nontransfused recipients (52 versus 23 per cent, respectively, at two years, P less than 0.001). The beneficial effect of transfusions was noted whether or not lymphocytotoxic antibodies were produced, provided adequate screening was performed before transplantation. Transfusions did not alter the degree of stimulation in the mixed lymphocyte culture. More liberal use of transfusions and frequent screening for cytotoxic antibodies would probably result in more effective cadaver-kidney transplantation.

Blood Transfusion↗
PubMed1977

Transient LW-negative red blood cells and anti-LW in a patient with Hodgkin's disease.

LW-negative (LW4) red blood cells and anti-LW antibody were discovered in the blood of a 50-year-old white male with Hodgkin's disease and blood type O. Compatible red blood cells for transfusion could not be obtained because available LW-negative cells were either type A, LW4, or type O, LW3. Following cytotoxic therapy for his basic disease, the anti-LW disappeared and his red blood cells developed normal reactions with anti-LW sera.

Blood Group Incompatibility↗
PubMed1977

The influence of presensitization on graft survival rate.

Graft survival rate was evaluated in 61 recipients with greater than 50 percent frequency of performed antibodies to selected panel cells. This includes recipients of primary cadaver grafts, secondary cadaver grafts, and living related grafts. Graft survival rate also was evaluated in 199 recipients with pretransplant antibodies reacting with 10 to 50 percent of panel cells and in nonsensitized patients. The results show that good graft survival can be obtained in many hyperimmunized patients, particularly in recipients of primary renal allografts (66 percent cadaver graft survival rate at 2 years). However, sensitization following rejection of an allograft appears to confer a less favorable prognosis. The nature of recipient presensitization and the precise specificity of each reactivity cannot always be explained. This is exemplified in three patients in whom broadly reactive lymphocytotoxic antibodies were not directed against HL-A antigens. Since the number of sensitized patients who await renal transplantation is increasing, there should be no hesitation in proceeding with transplantation, particularly with primary grafts. Emphasis, however, must be placed on frequent prospective recipient serum sampling so that transient high levels of cytotoxins do not escape detection and therefore can be easily selected out for cross-matching against potential donors.

Antibodies↗