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Biomedical subjects

C F Bryan

Publications and source records attributed to C F Bryan.

46 records · Page 3Linked to original sources
PubMed1984

Serum inhibitor in systemic lupus erythematosus associated with aplastic anemia.

Hematologic complications of systemic lupus erythematosus (SLE) usually involve peripheral destruction of blood elements. We report a case of SLE-associated aplastic anemia in which an IgG complement-dependent antibody, obtained from the patient's disease-phase serum but not remission-phase serum, suppressed growth of granulocyte-macrophage progenitor cells from bone marrow of normal donors in vitro. Therapy with plasmapheresis and immunosuppression resulted in lasting remission.

Adolescent↗
PubMed1983

Genetic studies in multiple myeloma. 1. Association with HLA-Cw5.

Human leukocyte antigens (HLA) were identified in 22 black Americans with multiple myeloma. No significant association was observed between antigens at either the A or the B locus. At the C locus, in contrast, HLA-Cw5 was more prevalent in the patient group, four of 22 having it, compared with the control group, in which two of 138 individuals possessed it. All four patients with HLA-Cw5 were males. Those results suggest that genetic factors, perhaps in conjunction with an environmental change, may be responsible for the recent increase in incidence in myeloma in black Americans, especially in males.

Adult↗
PubMed1983

The immunoregulatory nature of iron. I. Lymphocyte proliferation.

An increasing body of evidence suggests that iron may regulate certain immune functions in vitro. Its effects on proliferative responses of human peripheral blood mononuclear lymphocytes (PBM) to various mitogens was therefore investigated. The results showed that it enhanced such responses to pokeweed mitogen (PWM) but suppressed those to phytohemagglutinin (PHA) and to concanavalin A (Con A). Furthermore, the enhancement was mediated by T rather than B cells. In conclusion, those results provide further evidence for the hypothesis that iron has certain immunoregulatory properties in vitro.

Adult↗
PubMed1983

Thermostable erythrocyte rosettes in chronic renal failure and allograft rejection.

Rejection of an allograft usually is preceded by activation of T lymphocytes, in which state such cells may be identified by their ability to form thermostable rosettes with sheep erythrocytes (TE-R). The objective of the present work, therefore, was to determine whether or not enumeration of TE-R in the peripheral blood was of any value in the diagnosis of rejection. The results showed no significant differences between TE-R (mean +/- SEM) in normal subjects (9.9 +/- 1.3; n = 25), renal allograft recipients without rejections (13.5 +/- 1.7; n = 5) and in patients who suffered from acute tubular necrosis in the posttransplant period (12.4 +/- 2.5; n = 8). In contrast, recipients who had rejection episodes showed a marked rise in TE-R levels (43.0 +/- 4.0; n = 11) about two to seven days prior to the diagnosis of rejection by clinical and chemical criteria. Furthermore, TE-R remained high if the rejection episodes turned out to be irreversible after therapy (42.2 +/- 3.7) but fell if the episodes were reversible (19.9 +/- 3.2). TE-R values were elevated in patients with chronic renal failure on maintenance hemodialysis (45.7 +/- 4.9; n = 23). Neither acute dialytic runs or acute infections altered TE-R values. In conclusion, those results show that enumeration of TE-R may be helpful in the early diagnosis of allograft rejection, before clinical and chemical stigmata are apparent.

Erythrocytes↗
PubMed1982

Cyclomunine: a potent inhibitor of rat and canine lymphocytes.

In the present study we examined the effect of a recently isolated hexacyclodepsipeptide, Cyclomunine (Servier, France), on certain parameters which assess cellular and humoral immunity in the rat and dog. Our data establish Cyclomunine as a potent in vitro inhibitor of 3H-thymidine incorporation by lymphocytes. The concentrations of Cyclomunine required to abrogate mitogen or allogeneic lymphocyte stimulated 3H-thymidine incorporation was greater in the dog than in the rat, 15 micrograms/ml versus 10 micrograms/ml, respectively, to achieve greater than 99% inhibition. Little cytotoxicity was noted at concentrations below 25 micrograms/ml. Oral administration of Cyclomunine to rats (50 mg/kg dissolved in corn oil) did not significantly alter white blood cell count, lymphocyte-polymorphonuclear cell differential, body weight, or histological architecture of the liver, spleen, lymph node or kidney. Our results show that in vitro, Cyclomunine is highly effective in suppressing lymphocyte proliferation. In vivo, Cyclomunine appears to have little myelosuppressive effect a property shared with Cyclosporin A. Cyclomunine may hold promise as a clinically useful immunosuppressive agent.

Animals↗
PubMed1981

Differential inhibition of the MLR by iron: association with HLA phenotype.

The effect of iron on the MLR was examined by pretreating peripheral blood mononuclear cells from 77 unrelated Caucasians with five concentrations of Ferric-citrate (10.0 mM, 1.0 mM, 0.1 mM, 0.01 mM and 0.005 mM). After incubation with the metal, the cells were washed and cultured in a one-way MLR with a pool of stimulator cells. Cell viability remained unchanged (greater than 90 percent) during the 6-day culture period. Citrate per se had no effect on either the responder or the stimulator population. Iron treatment influenced the MLR in the following ways: (1) a variable degree of inhibition was observed which related to the dose of Ferric-citrate used and to HLA phenotype, (2) the responder but not the stimulator cells were affected, (3) no statistically significant differences were seen between female and male donor cells and (4) the mean percent response of cells from HLA-A2 donors were significantly (0.005 less than P less than 0.01) less susceptible to iron exposure than those from non-HLA-A2 individuals. The present results indicate that iron can interact with lymphoid cells and influence some immunological functions in vitro. The possibility is discussed that similar interactions take place in vivo which could contribute to the prognosis of certain diseases associated with particular HLA phenotypes.

Adult↗
PubMed1977

Serologically detected lymphocyte antigens in Holstein cattle.

Lymphocytes from 103 Holstein cattle were tested with 11 antilymphocytotoxic sera. Four of these sera were produced by whole blood immunization; these generally yielded lymphocytotoxicity against a large number of animals in each test panel. The majority of the sera were collected from parous cows which had never been immunized. Observations about this latter group of sera are (1) lymphocyte antibodies, may occur by alloimmunization in foetal-maternal interaction, (2) normal sera from non-immunized parous cows generally had a narrower specificity of antibodies than from parous cows immunized with blood from unrelated animals and in some cases these antisera may be monospecific, and (3) these sera from parous cows are easy to obtain without the need for laborious immunizations. Analysis of these lymphocytotoxic sera indicate several reagents were obtained which possessed different antibodies; these were useful in detecting polymorphism of cattle lymphocyte antigens. Using these 11 sera, an analysis of the reactions patterns among 103 Holsteins, including parent-offspring data resulted in the postulation of several alleles. These data suggest that cattle lymphocyte antigens are very polymorphic and inherited.

Alleles↗
PubMedDate not supplied

Augmentation of the antibody response by hapten help. II. Determination by many genes outside the MHC.

The purpose of the present work was to characterize the immune response (Ir) genes that influence augmentation of the antibody response by help with the hapten azobenzene-arsonate (ABA). Hapten help was measured as the augmentation in the plaque-forming cell (PFC) response to bovine gamma globulin (BGG) after priming mice with ABA conjugated to ovalbumin (OVA) and challenging subsequently with ABA-BGG. The first approach involved inbred mouse strains that were matched for H-2 but differed in their non-H-2 genetic backgrounds. B10.D2 mice were low responders even though they shared the H-2d haplotype with BALB/c and DBA/2 mice, which were high responders. C57BL/10 mice were high responders even though they shared the H-2b haplotype with C57BL/6, C3H.SW, and A.BY mice, all of which were strains that were low responders. The second approach was to identify any segregation of H-2 with the gene(s) encoding susceptibility to hapten help in the backcross generation. (BALB/c X C57BL/6) F1 hybrids were backcrossed to C57BL/6. The results showed no association with the major histocompatibility complex (MHC).

Animals↗