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Biomedical subjects

J Prazák

Publications and source records attributed to J Prazák.

At least 19 recordsLinked to original sources
PubMed1991

Duffy locus linkage and HLA antigens in hereditary motor-sensory neuropathy.

The Duffy system, Fya, Fyb, and HLA antigens were studied in 86 members, 39 affected, 47 healthy subjects, of 17 families with HMSN types I, II and III. The incidence of autosomal dominant as well as recessive, or sporadic forms was registered. In the autosomal dominant form of HMSN type I a close linkage was found between the genes coding the disease under study and the determinants Fya and Fyb. Recombination was found in only 9.1% of the cases. A study of HLA antigens revealed a major decrease in antigen B27 in the patients under scrutiny. An identical haplotype of most of the parents was a conspicuous feature in families with the autosomal dominant form of HMSN type I.

Adolescent↗
PubMed1990

[The significance of the thrombocyte crossmatching test].

The authors investigated the dependence of the results of the crossover test with thrombocytes and lymphocytes of the donor and serum of the recipient on the rise of thrombocytes 1 and 24 hours following administration of a thrombocyte concentrate. The clinical condition of the patient at the time of thrombocyte administration was taken into account. The donor of thrombocytes isolated in a blood element separator was selected from a panel of cca 800 subjects with previously assessed HLA antigens. A total of 36 administered concentrates was evaluated. From the assembled findings it may be concluded that the result of thromboconcentrate transfusion is significantly influenced by adverse clinical factors in the patient such as splenomegaly, haemorrhage, febrile conditions. A positive crossover lymphocytotoxic test can predict reliably the ineffectiveness of thrombocyte administration. A positive crossover test with the donor's thrombocytes does not affect significantly the success of the transfusion. It seems thus that for the fate of administered thrombocytes the presence of HLA antibodies is decisive and not the presence of specific thrombocytic antibodies.

Antibodies↗
PubMed1990

[Use of flow cytometry in the determination of HLA antigens].

The authors compare the classical method of typing of HLA antigens by the microlymphocytotoxic test (CTX) and the results obtained by flow cytometry (FCTX). They investigated agreement of results as regards estimation of 14 HLA antigens, loci A and B. in 42 sera. They compared possibilities of flow cytometry using microquantities of material and investigated changes of results obtained by cytotoxic reactions after 24 hours. The results evaluated by linear regression analysis proved the comparability of flow cytometry and the classical microlymphocytotoxic test.

Cell Separation↗
PubMed1990

[Therapeutic effectiveness of thrombocyte concentrates in relation to the results of the lymphocytotoxicity test].

The authors analyze the effect of transfusions of 211 thrombocyte concentrates to polytransfused patients in relation to the results of the crossover test between donor and recipient, using the lymphocytotoxic test (LCT). In negative LCT tests the adequate and inadequate effect was 50%. After elimination of non-immune influences (splenomegaly, febrile temperature) the percentage of adequate effects rose to 70%. In LCT positive results the effect of administration of thrombocyte concentrates declined to 30%. The authors discuss practical possibilities and ways to select suitable donors to achieve an optimal therapeutic effect of substitution therapy.

Blood Transfusion↗
PubMed1990

Histocompatibility locus antigens (HLA) in the epidermoid type of lung carcinoma.

HLA-A and B antigens were determined in a study of 162 patients (93 epidermoid type, 20 adenocarcinoma, 26 small-cell carcinoma and 23 undifferentiated types) with lung cancer. Differences between antigen frequencies in cancer and control populations were studied by chi 2Y analysis or Fisher's exact test. Survival data were analyzed using Cox's model for censored data. Cancer patients had a decreased frequency of the antigen HLA-B40 (chi 2Y = 14.15, P = 0.00018, Pc = 0.003, relative risk = 0.21). Patients with HLA-A10, A 11 and B27 had a shortened mean survival time. Patients with HLA-B12 had a prolonged survival time.

Adenocarcinoma↗
PubMed1990

[Immunologic monitoring of bone marrow transplantation. Experience with 16 cases].

HLA-A, B antigens and the ABO group were examined in 184 patients with aplasia of bone marrow and leukaemia and in 373 of their relatives, mostly siblings. A HLA-A, B donor, identical or compatible, was found for 35.87% patients, a HLA-DR identical for 84.21% of 38 patients who had a HLA-A, B identical relative. Bone marrow was transplanted to 16 patients (10 with bone marrow aplasia, 6 with acute or chronic leukaemia), with one exception bone marrow from a sibling. The bone marrow was accepted in all patients but two where the transplantation was made despite MLC positivity. From the results ensues that it is essential for successful transplantation of bone marrow to ensure maximal identity between donor and recipient as regards the ABO group, HLA antigens and negativity of the MLC reaction. The negativity of the MLC reaction is more important than HLA-DR identity; when assessing only one HLA-DR antigen in a donor identical with the patient, it cannot be ruled out that on the lymphocytes of the donor there exists another one which was not detected. The authors discuss the causes of different results of the MLC reaction and HLA-A, B, DR typing.

ABO Blood-Group System↗
PubMed1990

[The HLA crossmatching test before thrombocyte transfusion. Comparison of 3 methods].

Weak accessory HLA antibodies in HLA sera were assessed by three test--the microlymphocytotoxic, antiglobulin cytotoxic and fluorescent cytotoxic test. Most frequently they were detected by the antiglobulin cytotoxic test (69.64%), followed by the fluorescent cytotoxic test (55.73%) and least frequently by the microlymphocytotoxic test (45.77%). From the results ensues that the antiglobulin cytotoxic test is a suitable method of crossmatch before thrombocyte transfusions to patients who developed reactions after transfusions or where therapy failed although the crossmatch was performed by the microlymphocytotoxic test between the donor's lymphocytes and the patient's serum and the test was negative.

Blood Transfusion↗
PubMed1990

[Use of monoclonal antibodies in HLA immunology].

The author gives an account of the classification and use of HLA monoclonal antibodies. In experimental work the author demonstrates the contribution of investigations of the expressivity of histocompatible antigens class I and II and their changes in sound and tumourous tissues. In clinical practice they are important in particular in transplantology--cleaning of bone marrow, follow up of the GvH reaction, monitoring of patients. HLA monoclonal antibodies serve to reveal the polymorphism in the HLA sphere and the follow up of general biological laws.

Antibodies, Monoclonal↗
PubMed1990

[Immunologic profile in patients with acute anterior uveitis].

The authors investigated 52 patients (22 men and 30 women) with acute anterior uveitis where they ruled out systemic autoimmune disease, metabolic disease and focal or chronic infection. At the time of the infection the patients had not been treated for several months by any immunosuppressive treatment. The authors investigated in these patients serum concentrations of immunoglobulins G, A and M, the concentration of the C3 component of complement and the concentration of circulating immune complexes. Before the onset of therapy they investigated the response to antigens of the Immunoskin test. They assessed also the ratio of transplantation antigens class I by the microlymphocytotoxic test. They compared furthermore immunological indicators in subjects with a first attack and relapse of the disease and in groups, classified by the severity of the inflammatory symptoms. The authors detected significantly more frequently (p = 0.0005) the incidence of HLA-B27 antigen. Those where it was present were more frequently affected with a severe inflammation, as compared with subjects who did not have this phenotype (p less than 0.04). The relapse of the disease was more frequent in women (p = 0.1). The immunological laboratory findings did not differ in the first attacks and relapses of the disease, differences were, however, found in groups which differed as to the severity of inflammatory symptoms. In these groups the response rate to tests of skin sensitivity differed also. Based on these findings the authors assume that the ratio of immune processes in the development of acute idiopathic anterior uveitis cannot be ruled out.

Acute Disease↗
PubMed1989

[Changes in the expression of class I HLA antigens in patients with blood disorders].

In 146 patients with haematological diseases changes in the assessment of HLA antigens after repeated examinations were investigated. In 68.49% of the specimens all HLA antigens were assessed correctly, 8.9% had antigen losses and 22.6% responded by a polyreactive reaction. Changes of the HLA expressivity in the sense of loss or polyreactivity during repeated examinations were followed up and possible causes of changes of HLA expression are discussed.

Histocompatibility Antigens Class I↗
PubMed1989

[Is the fluorescence cytotoxicity test for the determination of HLA-DR antigens more sensitive than the classical microcytotoxicity test?].

The authors compare the sensitivity of the testing methods for determining HLA-DR antigens on B-lymphocytes and monocytes (classical eosin technique) with the fluorescence cytotoxic tests (FCT). The assessment of results of DR specificity determination in blood donors and patients with blood disease showed comparability of the tests. The rate of concordance ranged from 88-89%. The paper discusses the advantages and disadvantages of each method.

Cytotoxicity Tests, Immunologic↗
PubMed1989

[HLA-A, B-antigens and hypertrophic cardiomyopathy].

21 HLA-A, B-antigens were typed in 82 patients with hypertrophic cardiomyopathy and their 17 diseased relatives in 15 families, and their frequency was statistically compared with 300 healthy persons. A statistically significant lower frequency of the HLA-antigen B35 could bei stated (3.66% in contrast to 19.33%). An insignificant occurrence of HLA-B40 and a more frequent occurrence of HLA-Bw22 were statistically significant only before the p-correction. A statistic evaluation was done also in the groups of patients who were subdivided according to the age, the breadth of the ventricular septum and the presence of the obstruction. The importance of the results for the pathogenesis and prognosis of the disease was discussed.

Adult↗
PubMed1989

[Cooperation between the volunteer bone marrow donor section at the Institute of Hematology and Blood Transfusion, Prague, and the Caitlin Raymond Registry of Bone Marrow Donor Banks. 1 year experience].

The authors report on their one-year experience of co-operation with the Caitlin Raymond Registry of Bone Marrow Donor Banks in the selection of suitable bone marrow donors. Out of the 280 requirements received a total of seven donors were singled out - identical in HLA-AB antigens though unsuitable in the DR system.

Bone Marrow Transplantation↗
PubMed1989

[Rabbit anti-thymocyte globulin, the cause of false-positive results in the microlymphocytotoxicity test?].

The authors describe a positive crossover reaction between serum of a female patient treated with rabbit antithymocytic globulin and donor lymphocytes. In the serum of the patient with inhibition of the bone marrow HLA cytotoxins, thrombolysins, granulocytotoxins and granuloagglutinins were detected. Complete and incomplete thromboagglutinins were not detected. Two days after the positive tests no type of antibodies was detected in the patient's serum. The authors discuss the reasons for the development of the crossover reaction.

Adult↗
PubMed1989

Fluorescence crossmatch testing.

This paper is a short evaluation of the crossmatch testing performed with the fluorescence cytotoxic test to detect HLA compatibility of the platelet concentrates administered. From a total of 1,500 reactions between HLA incompatible donors and recipients mutual agreement was achieved in 96% of the reactions. HLA compatibility between donors and recipients was achieved in 97.31%. Advantages of the fluorescence method were stressed out.

Anemia, Aplastic↗
PubMed1989

[Duffy blood groups and HLA antigens in hereditary motor-sensory neuropathy].

The Duffa system (Fya Fyb) and HLA antigens were examined in 86 subjects (39 affected, 47 healthy) in 17 families with HMSN type I, II and III. They recorded the incidence of autosomal dominant as well as recessive (possibly sporadic) forms. In the autosomal dominant form of HMSN type I a close relationship was detected between genes coding the investigated disease and blood cell signs Fya and Fyb. Recombination was found only in 9.1% of the cases. Investigation HLA antigens revealed marked reduction of the B27 antigen in the investigated patients. A striking sign in families with the autosomal dominant form of HMSN type I was an identical haplotype of the majority of parents.

Blood Group Antigens↗
PubMed1989

Study of HLA antigens in patients with Hodgkin's disease.

This paper studies relations of 21 HLA antigens of the A and B loci to selected characteristics in a group of patients with Hodgkin's disease. The investigated characteristics are age, sex, histological patterns, clinical stage and symptomatology. The considered group consists of 68 patients, 37 males and 31 females aged from 19 to 66 years and from 26 to 63 yr, respectively. A comparison between antigen frequencies for patients and controls (301 unrelated blood donors) is carried out. The results confirm that there is no relation between HLA antigens and Hodgkin's disease. A significant increase of A11 is found for females under 40 yr. Certain HLA antigens show significant correlation neither with the patient age nor with clinical or histological stages. A significant increase of B5 is observed for 16 relapsed patients. For them, significant test characteristics are found in the presence of cross-reacting HLA-B5, B35.

Adult↗