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J Kaplan

Publications and source records attributed to J Kaplan.

At least 415 records · Page 23Linked to original sources
PubMed1978

Expression of human T-lymphocyte antigens by natural killer cells.

Rabbit antisera against human T-lymphocyte and B-lymphocyte antigens (anti-HTLA and anti-HBLA, respectively) were used to characterize natural killer (NK) cells mediating spontaneous cell-mediated cytotoxicity for myelogenous leukemia cell line K562 as measured in a 51Cr-release assay. NK activity of lymphocyte suspensions was abrogated by incubation of the suspensions in anti-HTLA plus complement but not by incubation in anti-HBLA plus complement. The effect of anti-HTLA was due to removal of NK cells rather than antigen-antibody complex inhibition of NK cells inasmuch as lytic complement was necessary. The results indicated that NK cells were HTLA+-HBLA- and thus supported the concept that NK cells are T-cells.

Animals↗
PubMed1978

Cytotoxicity of human peripheral lymphocytes in cell-mediated lympholysis; antibody-dependent cell-mediated lympholysis and natural cytotoxicity assays after mixed lymphocyte culture.

Lymphocytes that have been purified by Ficoll-Hypaque centrifugation lose antibody-dependent and natural cytotoxic activities upon culture in tissue culture medium supplemented with human plasma. However, stimulation of peripheral lymphocytes in the mixed leukocyte culture (MLC) appears to enhance killer (K) and natural killer (NK) activities in addition to generating cytotoxic T ymphocytes. Enhancement of NK and antibody dependent activities appears to correlate with cell division as measured by 3H-thymidine uptake. However, elimination of dividing cells in the MLC by addition of 5-bromodeoxyuridine has no effect on NK and K cells activities. Since this treatment abolishes cell-mediated lympholysis mediated by cytotoxic T lymphocytes, it is a useful probe for determining the relative activities of NK, K, and cytotoxic T lymphocyte effector cells after lymphocyte stimulation.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1978

Expression of human T lymphocyte antigens by killer cells.

K cells, the effectors of antibody-dependent cell-mediated cytotoxicity, were found to express human T but not B lymphocyte antigens detected by rabbit anti-HTLA and anti-HBLA. Pretreatment of effector cells with anti-HTLA+C inhibited ADCC by specifically lysing K cells: no inhibition of ADCC by anti-HTLA occurred when deltaC was substituted for C. By contrast, pretreatment of effector cells with anti-HBLA nonspecifically inhibited ADCC, probably for forming antigen-antibody complexes with HBLA+ cells in effector suspensions: a) treatment with anti-HBLA deltaC was more inhibitory of ADCC than treatment with anti-HBLA+C, and b) the inhibitory effect of anti-HBLA on ADCC was either eliminated or markedly reduced if effector suspensions were first passed through a nylon fiber column, a procedure that removed most HBLA+ cells without affecting K cell activity. HTLA antigens expressed by K cells and NK cells are the same as HTLA antigens expressed by thymocytes since thymocytes completely absorb the anti-K cell and NK cell reactivity of anti-HTLA.

Animals↗
PubMed1978

Characterization of thymosin-responsive peripheral blood null cells.

Suspensions of human peripheral blood lymphocytes were enriched for E rosette-negative (E-) surface immunoglobulin-negative (SIg-) "null" cells expressing either human T or human B lymphocyte antigens. These enriched suspensions were then tested for responsiveness to activation of E rosette formation by thymosin. Thymosin activated some human T lymphocyte antigen-positive E-SIg- but not human B lymphocyte antigen-positive E-SIg- cells to form E rosettes. Therefore, thymosin-responsive peripheral blood null cells appear to be precommitted to the T- cell line of differentiation.

Adult↗
PubMed1977

Inhibitory effects of tunicamycin on procollagen biosynthesis and secretion.

Chick embryo cells were briefly exposed to the antibiotic, tunicamycin. Pre-exposed cells, compared to control cultures, showed a severe, progressive inhibition of the incorporation of glucosamine and mannose into total cellular macromolecules. Inhibition of the incorporation of glycine, leucine and proline was also progressive but not as marked as for the carbohydrates. Cellular secretion of all macromolecules was severely impaired. while comparison of the procollagens showed no difference in their subunit size or in their degree of glycosylation; the intracellular content of procollagen polypeptides was similar for both types of cells. In vitro studies showed that tunicamycin selectively inhibited glucosamine, but not mannose, incorporation into macromolecules. The composite results indicate that tunicamycin effectively inhibits protein synthesis, protein glycosylation and protein secretion in chick embryo cells.

Animals↗
PubMed1977

Inbreeding in recessive diseases.

The consanguinity of parents (born in France) of individuals who have a recessive disease has been studied. The frequency of first cousin marriages is less than 0.2% in the general French population. Among the parents of affected individuals the following frequencies of first cousin matings were observed: cystic fibrosis: 1.4% cystinosis: 7.1% nephronophtisis: 5.6% spinal muscular atrophy: 4.5% albinism: 5.0% achromatopsia: 12.5% (Albinism and spinal muscular atrophy are heterogeneous conditions). The increase in the frequency of first cousin marriage relative to that of the general population is much greater, as expected, in cystinosis, which is a rare disease, than in cystic fibrosis, which is the most frequent recessive disorder in France. Inbreeding in cystinosis and cystic fibrosis was also studied by computing the distance between parental birth places. This distance is smaller in cystinosis than in cystic fibrosis.

Albinism↗
PubMed1977

[Genetic counselling (results of ten years experience). IV. Attitude of persons seeking counselling and reliability of the counsel (author's transl)].

The authors, from their personal experience arising from 766 consultations, show that the percentages of marriages or procreations in subjects themselves suffering from a disorder, or with affected relatives, are independent of the risk estimated for their offspring. The procreation rate in couples with affected children is lower in high risk cases and depends also on the family composition. It appears that this procreation is voluntary in the great majority of cases because there were very few terminations of pregnancy among the couples seen before procreation. The estimated risks correspond to the risks observed but the authors insist that there is a relatively high proportion (4.4 per cent) of children born with a disorder different from that which motivated the consultation.

Abortion, Eugenic↗
PubMed1977

T and B lymphocyte antigen-positive null cell leukemias.

To clarify the nature of null cell acute lymphoblastic leukemia (ALL) we tested null lymphoblasts and other leukemic cells for human T and B lymphocyte antigens detected by reciprocally absorbed rabbit antisera prepared against autologous T and B lymphoblast cell lines HSB-2 and SB. Blasts from 4 of 4 patients with T cell leukemia and from 2 of 10 patients with null cell leukemia expressed T cell but not B cell antigens. Blasts from 8 of 10 patients with null cell leukemia, one patient with B cell leukemia, and 3 of 3 patients with acute myelogenous leukemia expressed B cell but not T cell antigens. T lymphocyte antigen-positive null cell ALL appear to be a form of T cell ALL. B antigen-positive null cell leukemia could arise from either immature B cell precursors or from multipotential stem cells.

Adolescent↗
PubMed1977

[Genetic counselling (results of ten years experience). II. Requests (author's transl)].

The authors give a summing up of ten years of genetic counselling concerning 1271 requests and single out two equally important categories of consultants. The first might require premarital counselling (in cases of consanguineous unions, or when one of the partners or relatives are affected) but, in fact, come to consultation, four times out of ten, after marriage and even after procreation. The consultants of the second group need prenatal counselling either because a child suffers from a hereditary disorder, or because earlier pregnancies did not come to term. Whichever the type, one consultation out of seven concerned a pregnant woman. A classification by type disorder and by mode of transmission is given.

Abnormalities, Multiple↗
PubMed1977

[Genetic counselling (results of ten years experience). III. Evaluation of risk (author's transl)].

Among 924 consultations for definite or probable genetic disorders, two persons out of five seeking counselling run a high risk (10% or more) of having an affected child, one in five a risk varying between 1% and 9%, and two out of five a negligeable risk (less than 1%). In most cases (three out of four) individuals with affected relatives could be completely reassured, whilst one out of two affected persons seeking counselling ran a high risk of having a child who would suffer the same handicap. Among the normal parents with affected children, one out of three could be completely reassured, but on the other hand the same proportion ran a high risk of having another affected child. The calculated risks were compared in prenuptial, pre-pregnancy and prenatal counselling. The evaluation of the risk is only the first step in the counselling and certain special situations were chosen to demonstrate the factors which can modify the risk. The authors stress that genetic counselling, which is rarely simply indicative, should often be directive. In some cases, the prenatal diagnosis converts the theoretical risk into a certainty.

Genetic Counseling↗