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Biomedical subjects

M Lopez

Publications and source records attributed to M Lopez.

At least 469 records · Page 26Linked to original sources
PubMed1976

Hepatocyte population dynamics during hydrocortisone and thioacetamide treatment.

The orderly organization in a number of discrete classes of weight persists in the hepatocytes during acute and chronic poisoning with thioacetamide and during a prolonged treatment with hydrocortisone, though many striking cytological and structural changes occur in the liver. The number of hepatocyte classes decreases under hydrocortisone treatment and during acute and chronic thioacetamide poisoning, and increases during recovery after acute thioacetamide poisoning and during the late phases of chronic thioacetamide poisoning. This is due to decrements and increments in dry mass of the hepatocytes, which occur by steps, through repeated losses and additions of a constant amount of solids substantially corresponding to the class period. Such a mechanism is similar to that acting in the hepatocyte atrophy due to starvation and in the hepatocyte enlargement occurring during postnatal development. Therefore, the increment and the decrement in dry mass by defined steps takes place in the hepatocytes in both physiological and pathological conditions.

Acetamides↗
PubMed1976

An auto-anti-b in an a1b person. Serological studies.

The serum of a patient (Mr. Lat) with the regular blood group A1 B contains an anti-B reacting with all cells having a B antigen except Bx and cis AB. The anti-B reacts at 4 degrees C and occasionally at room temperature as shown by agglutination, absorption-eluction and by thermo-dynamic assays. The antibody is regarded as an irregular autoantibody belonging to the group of the so called "suppressed" or "latent" antibodies.

ABO Blood-Group System↗
PubMed1976

Allergenicity and immunogenicity of Basidiomycetes.

Species selected from six families of the class Basidiomycetes were evaluated for allergenicity in atopic and nonatopic individuals and for immunogenicity and antigenic cross-reactivity in experimental animals. Between 42% and 68% of atopic asthmatics demonstrated positive Type 1 wheal-and-flare skin reactivity to basidiomycete metabolic and somatic antigens. Sixty-four percent of skin test-positive atopic asthmatics exhibited positive RAST to as basidiomycete metabolic antigen and 50% were positive to somatic antigen. Negative RAST results were obtained in all nonatopic control sera. Only an occasional individual demonstrated positive serum antibasidiomycete precipitins by counterimmunoelectrophoresis. All basidiomycete species studied were highly immunogenic in the rabbit and most appeared to contain an electrophoretically heterogenous group of antigens with predominant anodal mobility. Ouchterlony double-diffusion analysis employing hyperimmune rabbit antisera indicated the presence of shared antigens among all basidiomycete species with the exception of Pleurotus. Rabbit antibasidiomycete sera did not cross-react with antigens of several common species of the Fungi imperfecti. Results indicate that many atopic asthmatics of the Gulf South area demonstrate IgE-medicated hypersensitivity to basidiomycete antigens as evidenced by positive wheal-and-flare skin reactivity and/or RAST. Basidiomycetes are also immunogenic in the rabbit and possess antigens that do not cross-react with those of certain Fungi imperfecti.

Adult↗
PubMed1976

[Cad antigen in the French population].

An investigation of Cad phenotypes in the French population had been carried out in 1973, in four Blood Transfusion Centers (Mulhouse, Nancy, Paris, Versailles), B and O red cells were tested with the Dolichos Biflorus lectin. Out of 78.528 donors, 56 were found to have the Cad antigen on their red cells. The mean frequency was 0,07%. Nevertheless, this frequency varied among the four above mentioned Blood Transfusion Centers: the observed differences were probably due to the preparation procedure of the Dolichos biflorus extract. The family investigation permitted the analysis of four families with at least three Cad individuals. The independence of the Cad system and of Auberger, Gc, Hp, C'3, PGM, Pac and ADA was demonstrated. A quantitative agglutination study on these Cad samples using the Dolichos biflorus lectin,and a selected AB serum showed a high variability of the erythrocyte Cad Strength, even within one family. Most Cad samples were found polyagglutinable when a sensitive technique and selected AB sera were used. All adult sera contained an anti-Cad1 antibody, except Cad1 individuals. Although strong Sda reactivity was always found in Cad red cells, the anti-Cad and anti Sda specificities were not identical: this was demonstrated by the absorption and inhibition tests of anti-Cad and anti-Sda reagents absorption and inhibition tests of anti-Cad and anti-Sda reagents with Sda material. From thf Cad red cells, there was no evidence of the existence of separable anti-A1 and anti-Cad agglutinins in the Dolichos biflorus lectin.

Blood Group Antigens↗
PubMed1976

[Quantitative and qualitative study of ABH antigens of cis AB blood group].

Fourteen cis AB blood samples belonging to 6 families from Belgium, France, Japan and Germany were studied with quantitative agglutination and fixation assay. Results showed that ABH antigens of cis AB erythrocytes significantly differ from "trans" AB controls: the H amount is higher than in trans AB and similar to that of A2 controls; the A amount is similar to that of A2 cells; the number of A sites per cell as measured with a 125-I labelled IgG anti-A from a rabbit ranges from 170 000 to 580 000 in cis AB samples; the A1 reactivity seems to be related to the A antigen density of erythrocytes more than to a specific A1 antigen; the B reactivity is quite normal with immune anti-B sera but weak with naturally-occurring anti-B from A individuals. The reaction of B antigen of cis AB cells with a naturally-occurring anti-B from an A1O person exhibits a weaker enthalpy change than in trans AB cells. Most cis AB sera have anti-B activity, essentially at 4 degrees C. In saliva A and H substances are found in normal amounts but B substance is only evidenced by inhibition of autologous cells agglutination. Data obtained from this study do not favour any proposed hypothesis to explain the cis AB gene formation (crossing-over between A and B genes or A gene mutation).

ABO Blood-Group System↗
PubMed1976

An unusual Rh phenotype indicating heterogeneity of the Cw antigen.

A family is reported in which a new Cw antigen occurred in two generations. This was recognized by 17 anti-Cw sera, but by none of the 21 anti-C sera which were, however, shown to react strongly with common Cw+ cells. This unusual finding provides evidence that the Cw antigen is in fact heterogeneous. On the basis of data obtained from absorption-elution and coagglutination studies a tentative explanation is attempted: common Cw+ phenotypes are assumed to be Cw (+1+2) and the present phenotype Cw (+1-2). Anti-Cw sera should accordingly be anti-Cw1, whereas anti-C sera should only react with Cw2.

Antigens, Heterophile↗
PubMed1976

An immunological investigation of a family with chronic mucocutaneous candidiasis.

Chronic mucocutaneous candidiasis in two siblings of consanguineous parents suggested an autosomal recessive transmission of the disease. We evaluated the two affected persons and 21 members of their kindred for an inherited immunological defect. Six members of the kindred, including both patients, had negative skin-delayed hypersensitivity to Candida. The lymphocytes of both patients and three asymptomatic relatives had diminished in vitro blastogenic response when cultured with Candida albicans. Because the defect occurred in clinically unaffected relatives, we concluded that the lack of blastogenic response to C. albicans was not the only determinant for or may be unrelated to the clinical manifestations of the disease.

Antigens↗
PubMed1976

Polyagglutinability associated with the cad antigen.

Various anti-Cad and anti-Sda reagents were tested against a panel of Cad red cells in order to determine whether Cad and Sda antigens were identical. According to the results, although strong Sda reactivity was always found in Cad red cells, the two antigen specificities are not identical. The polyagglutinability of Cad red cells seems to be related to an anti-Cad present in all human sera but Cad, and not with anti-Sda antibody.

ABO Blood-Group System↗
PubMed1976

Jk(a-b-) phenotype in a French family. Quantitative evidence for the inheritance of a silent allele (Jk).

A Caucasian French family was investigated including two Jk(a-b-) sibs who had developed anti-JkaJkb. The parents were first cousins. Quantitative study of Kidd antigens using titration scoring and HD50 assay clearly showed the parents and a maternal aunt, phenotypically Jk(a+b-), to have a weak expression of Jka documenting thereby the transmission of the postulated silent gene Jk. Absorption, elution and coagglutination assays revealed the cross reactivity of the antibody developed by the two sibs. Leucocytes and platelets from these two individuals were not shown to absorb anti-JkaJkb.

Alleles↗
PubMed1976

Cis AB blood groups. Immunologic, thermodynamic and quantitative studies of ABH antigens.

Fifteen samples of cis AB bloods belonging to six unrelated families were tested by serological and thermodynamic assay techniques. The B and H antigens of cis AB bloods differ significantly from those of trans AB bloods. Differences were found among unrelated samples, but identical results were obtained within a given family : this could mean that there had been as many mutations as there were families.

ABO Blood-Group System↗
PubMed1975

[The Cis AB complex of the ABO system].

Members of six unrelated families from Japan, France, Belgium and Poland were studied in parallel. Major immunological features characteristic of the phenotype produced by the Cis AB complex are the following: 1) The red cell A reactivity is close to normal, is beyond the values of agglutination scores by Helix and by anti-A from B; likewise, with percent agglutination measurements, A reactive appears hiher than that of A2B cells; one sample only is slightly detected by anti-A from Dolichos. 2) The B reactivity, on the contrary, is lower than that of normal AB cells. A single sample is detected by anti-B from A1. All samples are well detected by anti-B from AW, Aend, Ax, Am but none is detected by anti-B from ABx, Cis AB, or by an auto-anti-B. Under standard conditions, percent aggutination is around 80, very close to that of normal AB cells, thus differentiating Cis AB from AB3 (some of which only reach this figure), and from ABx which are very far from this value. 3) An abnormally high reactivity to anti-H antibody is observed, higher than that of normal A2B, similar to that of A2 red cells. 4) Among secretors, A substance is found to be normal or in excess, H substance is in excess, while B substance is only detected by Cis AB red cells inhibition. 5)An anti-B antibody was identified in the samples studied; however, we recently received from Germany a Cis AB samples, the serum of which did not contain anti-B antibody. By these main characteristics, the studied samples seem to be identical; however, agglutination kinetics and thermodynamic methods show that they differ by their reaction with a same anti-B antibody in standard conditions. The reactive structures of the various samples are indeed different from one family to another. The main point is that identical values were observed in all samples within a same family. Thus, the various Cis AB can be considered as different families mutants.

ABO Blood-Group System↗
PubMed1975

[Cold agglutinin with anti-B specificity in an A1B subject].

A high titre cold autoagglutinin with anti-B specificity was found in the serum of an A1B group individual. It was associated with a low titre anti-I. This anti-B agglutinated most cells having a B antigen (normal B, A1B, A2B, from adult and cord bloods, B3), but failed to agglutinate Bx Cis-AB and Bh cells. Nevertheless, all these cells absorbed the anti-B SER at low temperatures. Fixation elution tests were also positive on the patient's cells and three consecutive absorptions on these cells completely removed the anti-B activity. The Coombs test was positive with anti-complement anti-globulin when the cells were sensitized by the serum at 4 degrees C. It was negative when the cells were sensitized at 37 degrees C. The patient did not show any sign of haemolysis. The anti-B was a IgM Kappa. Its reaction with normal B cells had an enthalpy change of - 36-000 cal./mole, i.e. very different from O ANd A individuals, but similar to that of the erythrocytic I antigen - anti-i antibody reaction. Quantitative measurements showed the erythrocyte B antigen similar to that of control A1B cells.

ABO Blood-Group System↗
PubMed1975

Incidence of serum anti-DNA precipitins in patients with systemic lupus erythematosus by counterimmunoelectrophoresis.

The technique of counterimmunoelectrophoresis (CIE) has been adapted for detection of serum precipitins to calf thymus (CT) DNA in patients with SLE, discoid LE, miscellaneous connective tissue and infectious diseases, and control populations. Of seventy-eight LE patients, 58% demonstrated anti-ss DNA precipitins, and 20% exhibited anti-ds DNA precipitins. Good correlation was noted between the presence of ss DNA precipitins and ss DNA binding values determined by the more sensitive ammonium sulphate precipitation assay. Depressed total serum haemolytic complement activity in CH50 mu/ml was noted in 64% of sera exhibiting ss DNA precipitins and 38% of those with negative ss DNA precipitins. There was a strong association, however, between ds DNA precipitins and depressed serum complement levels. Although less sensitive than primary binding assays, CIE can be used as a rapid and simple screening test for detection of circulating anti-native and denatured CT DNA precipitins. CT DNA serum precipitins are present in a significantly higher percentage of SLE patients when compared with other disease states and normal control populations.

Ammonium Sulfate↗
PubMed1975

Agglutination kinetics. A method for quantitative red cell antigen assays.

A simple, sensitive and highly reproducible method is described using a particle counting procedure for the study of agglutination percentage of red cells as a function of time. The method may advantageously be used for the current study of zygosity and other antigenic variations especially in family investigation.

Erythrocyte Count↗