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M Segall

Publications and source records attributed to M Segall.

13 recordsLinked to original sources
PubMed1991

Serology, restriction fragment length polymorphism, and sequence analysis of a unique HLA class II antigen, DR5x6.

We analyzed a new class II HLA haplotype, which we have designated DR5x6, by serology, restriction fragment length polymorphism (RFLP), and sequence analysis. As the name DR5x6 implies, the antigen is serologically closely related to both DR5 and DRw6. RFLP analysis of this haplotype suggests a close similarity with DRw11 haplotypes. The DNA sequences encoded by the second exon of its DRB1, DRB3, and DQB1 genes were also determined. Comparison of these sequences with those of alleles at these loci in other haplotypes suggests that this haplotype could have evolved from a DRw11 ancestor haplotype (DRw11-DRw52b (Dw25)-DQw7) by means of: (a) a gene conversion at the DRB1 locus involving DRw8 (Dw8.3) as the sequence donor, plus a point mutation or a gene conversion involving DR4-Dw4; and (b) a recombination event by which this haplotype would have acquired the DRw5a (Dw24) allele at the DRB3 locus.

Base Sequence↗
PubMed1979

Increased frequencies of aberrant sperm as indicators of mutagenic damage in mice.

We have tested the effects of TEM in 3 strains of mice using the sperm morphology assay. In addition, we have made an attempt to evaluate this test system with respect to experimental design, statistical problems and possible interlaboratory differences. Treatment with TEM results in significant increases in the percent of abnormally shaped sperm. These increases are readily detectable in sperm treated as spermatocytes and spermatogonial stages. Our data indicate possible problems associated with inter-laboratory variation in slide analysis. We have found that despite the introduction of such sources of variation, our data were consistent with respect to the effects of TEM. Another area of concern in the sperm morphology test is the presence of "outlier" animals. In our study, such animals comprised 4% of the total number of animals considered. Statistical analysis of the slides from these animals have shown that this problem can be dealt with and that when recognized as such, "outliers" do not effect the outcome of the sperm morphology assay.

Animals↗
PubMed1977

Mixed leukocyte culture incompatibility index for donor-recipient selection in kidney transplantation.

The mixed leukocyte culture test has been applied to selection of histocompatibility non-identical donor-recipient pairs for renal transplantation. The clinical course of transplant recipients who have histocompatibility mismatches but low mixed leukocyte culture stimulation is similar to that of mixed leukocyte culture and histocompatibility identical recipients. Living donor-recipient pairs with high mixed leukocyte culture stimulation had no better graft survival than cadaver recipients. An incompatibility index derived from mixed leukocyte culture may aid in the selection of satisfactory non-identical living related donors and may help avoid use of immunologically unsatisfactory living donors.

Cadaver↗
PubMed1976

Pooled stimulating cells as a "standard stimulator" in mixed lymphocyte culture.

Lymphocytes from normal unrelated donors were pooled and used as stimulating cells in mixed lymphocyte culture (MLC). Different pools, each consisting of cells from 20 or 30 different donors, stimulated approximately the same amount of 3H-thymidine incorporation by a given responder, and this "plateau level" of incorporation was different for different responders. Stimulation by pools of 20 cells was highly correlated with the general "responsiveness" of responding cells as measured by their mean response to a large panel of stimulating cells. Such pools may be useful as "standard stimulators" in quantitating MLC stimulation, and perhaps also in evaluating lymphocyte responsiveness of patients.

Bromodeoxyuridine↗
PubMed1975

Genetic and cellular control of in vitro models of allograft reactivity.

In each species sufficently studied, a single genetic region, the major histocompatibility complex (MHC), controls the strong transplantation antigens. Recent evidence suggests that the genetic control of differences important in allograft phenomenon is more complex than previously realized. In addition to the two loci, alleles of which control serologically defined (SD) antigens, there are other loci the phenotypic products of which lead to T-lymphocyte activation in mixed leukocyte culture. These latter loci have been referred to as LD (or lymphocyte defined). There appears to be a physiologic interaction between these two loci in that the LD differences seem to be important in the initial recognitive phases of the allograft reaction; the SD differences (or products of genes very closely linked to those determining the SD antigens) are important as a target for cytotoxicity as studied by the cell-mediated lympholysis test.

Animals↗