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Biomedical subjects

B H Petersen

Publications and source records attributed to B H Petersen.

At least 19 recordsLinked to original sources
PubMed1995

Detection of human growth hormone receptors on IM-9 cells and peripheral blood mononuclear cell subsets by flow cytometry: correlation with growth hormone-binding protein levels.

We have developed a method using flow cytometry to identify fluorescein-conjugated GH receptors (GHR) on IM-9 lymphocytes and circulating peripheral blood mononuclear cell subsets. Binding to IM-9 cells and peripheral blood mononuclear cells was concentration dependent and could be competitively blocked by the addition of unlabeled human GH, but not by the addition of rat or bovine GH or human insulin or PRL. Using two-color flow cytometric analysis, fluorescein-conjugated human GHR were readily detected on more than 90% of B lymphocytes and monocytes, but only variably on T lymphocytes. B Lymphocytes and monocytes had approximately 6000 GHR/cell. Using two-color flow cytometry, we identified GHR on circulating B lymphocytes in subjects with GH deficiency (n = 9), precocious puberty (n = 6), and Turner syndrome (n = 5) and in seven subjects with miscellaneous disorders, including familial short stature, bone dysplasia, Crohn disease, congenital adrenal hyperplasia, and acromegaly. The percentage of B lymphocytes expressing GHR in subjects with GH deficiency (mean +/- SD, 95 +/- 9%), precocious puberty (91 +/- 15%), and Turner syndrome (84 +/- 15%) was not different from that in normal volunteers (90 +/- 12%; n = 14). In 10 subjects, serum GH-binding protein levels were assayed simultaneously with B lymphocyte GHR. GH-binding protein was normal in all (mean, 1255 pmol/L; range, 773-1809). There was a good correlation between GHR expression on B lymphocytes and GH-binding protein levels (r = 0.75; P = 0.01). We postulate that GHR found on circulating B lymphocytes may contribute to the pool of receptors identified in serum as GH-binding proteins. Two-color flow cytometry appears to be an effective method for the detection of GHR on circulating peripheral blood mononuclear cell subsets. The evaluation of GHR on circulating B lymphocytes may prove to be a useful means of evaluating GH-GHR interactions in subjects with growth disorders.

Adult↗
PubMed1992

Quantitation of human anti-mouse antibody in serum by flow cytometry.

Clinical investigations utilizing murine monoclonal antibodies require techniques for the detection of the human anti-mouse antibody (HAMA) response in patient serum. We report here a flow cytometric assay for the quantitation of HAMA. Commercially available beads conjugated with goat anti-mouse antibody provide a solid phase matrix for a triple bridge immunoassay. The measurement of fluorescein labeled antibodies by flow cytometry allows accurate quantitation of the HAMA. The assay will detect antibody levels of approximately 1.0 ng/ml. Antibody recovery in serum samples with known amounts of antibody added was greater than 90% at levels greater than or equal to 10 micrograms/ml. Serum samples obtained from 41 patients prior to and after single or multidose infusions of KS1/4-Desacetyl-vinblastine were analyzed. These results were compared with HAMA titers previously determined by ELISA. With few exceptions, patients with low titers as determined by ELISA demonstrated low HAMA potencies by flow cytometry and those with highest titers the highest potencies. Patients with no detectable HAMA by ELISA were also negative by flow analysis. The results of our studies demonstrate that HAMA levels can be accurately and quantitatively determined by flow cytometry.

Animals↗
PubMed1991

The human immune response to KS1/4-desacetylvinblastine (LY256787) and KS1/4-desacetylvinblastine hydrazide (LY203728) in single and multiple dose clinical studies.

Monoclonal antibody (MoAb) conjugates have been used to treat a variety of malignancies. The majority of the MoAbs which have been used therapeutically are from murine sources. The infusion of these foreign proteins into humans can be expected to elicit anti-murine antibodies and may be one of the major limitations to the clinical use of murine MoAbs. In these studies, we report on the nature and specificity of the human anti-murine antibody (HAMA) response in patients given single and multiple infusions of the two Vinca alkaloid conjugates of the MoAb KS1/4, which recognizes tumor-associated antigens in a variety of adenocarcinomas. A HAMA response was induced in a majority of the patients receiving infusions of KS1/4 conjugates, regardless of the specific conjugate used or the number of infusions. The magnitude of the response did not appear to be dose related. Antibodies directed to the drug moieties of these conjugates, anti-Vinca alkaloids, were also induced in patients with HAMA responses. The magnitude of the anti-Vinca response paralleled that of the HAMA.

Antibodies, Monoclonal↗
PubMed1990

Two distinct abnormalities in patients with C8 alpha-gamma deficiency. Low level of C8 beta chain and presence of dysfunctional C8 alpha-gamma subunit.

The sera from three C8 alpha-gamma deficient patients previously reported to have a selective C8 alpha-gamma defect were analyzed by SDS-PAGE and Western blot using two polyclonal antisera to C8 alpha-gamma and a monoclonal antibody to C8 alpha. All three sera exhibited C8 alpha-gamma bands that dissociated into alpha and gamma chains under reducing conditions. Quantitation of the alpha-gamma subunit in these sera by a sensitive ELISA revealed an amount approximately 1% of that found in normal human serum. A similar assay performed with a specific antiserum to C8 beta showed unexpectedly low levels of C8 beta in these sera, which were confirmed by hemolytic titration of C8 beta. The remarkable differences between C8 alpha-gamma and C8 beta in the C8 alpha-gamma deficient sera was that in spite of their comparable immunochemical levels, C8 beta still exhibited functional activity whereas C8 alpha-gamma was totally inactive. That the residual C8 alpha-gamma was inactive was also proved by its inability to show lytic bands in an overlay system after SDS-PAGE and subsequent removal of SDS. The implications of these findings for a novel concept of C8 deficiency are discussed.

Blotting, Western↗
PubMed1990

Effect of treatment with biosynthetic human growth hormone (GH) on peripheral blood lymphocyte populations and function in growth hormone-deficient children.

GH influences the immune response. The mechanism is not known; however, the presence of receptors for GH on human lymphocytes as well as its ability to influence and modulate immune responses in animals suggest an association between GH and immune function in man. We evaluated the effect of recombinantly derived natural sequence human GH (hGH) on lymphocyte surface antigen expression, response to mitogenic stimulation, expression of interleukin-1 receptors, and production of anti-hGH antibodies in GH-deficient children. The only observed changes were a decrease in the percentage of B-cells and a transient increased reactivity to phytohemagglutinin stimulation. It appears from the results of our studies that the administration of hGH has a selective effect on lymphocyte immune function; however, we cannot eliminate a role for hGH in the initiation or regulation of antigen-mediated immune responses.

Adolescent↗
PubMed1988

Experimental drug-induced immune thrombocytopenia in monkeys.

In these studies we report the induction, by 7,8-dimethoxy-1H-3-benzaepin-2-amine HCl, of immune thrombocytopenia in monkeys and its characterization by flow cytometry. Three of eight monkeys developed thrombocytopenia following administration of high doses (35 mg/kg) of the drug. The characteristics of the thrombocytopenia, including rapid induction on rechallenge with the drug, met the criteria indicative of drug-induced immune thrombocytopenia. Platelet surface-associated immunoglobulin could be detected by flow cytometry as early as 21 days before the onset of thrombocytopenia. A critical concentration of antibody on the platelet surface appeared to be necessary for elimination of the platelets from the blood. Evidence from experiments using the serum from an affected monkey suggested that drug interaction with the platelet surface produced a site for antibody binding, possibly a neoantigen, which required the continued presence of the drug.

Animals↗
PubMed1988

Detection of platelet-associated immunoglobulin in immune thrombocytopenia by flow cytometry.

The development of a flow-cytometry (FCM) technique for the direct detection of antiplatelet globulins bound to the surface of platelets (platelet-associated immunoglobulins, or PAIg) is described and utilized to evaluate patients with idiopathic thrombocytopenic purpura (ITP). Elevated levels of platelet-bound globulin were detected by FCM in the ITP patients studied. When plasma was analyzed by FCM for the presence of antiplatelet antibodies, only one patient demonstrated elevated levels. The use of FCM in the direct analysis of PAIg may result in earlier diagnosis and better management of immune thrombocytopenias.

Blood Platelets↗
PubMed1986

Translocatable estrogen receptors in rat splenocytes.

Estradiol has previously been shown to suppress the response of the cellular immune system of the rat while enhancing the production of IgM antibodies. Analysis of the cytosol from rat splenocytes showed saturation of specific binding sites at concentrations of between 80 and 160 nM [3H]-estradiol with an approximate Kd of 12 nM. Competitive binding studies showed a dose-dependent decrease in the binding of [3H]-estradiol to the receptor in the presence of increasing concentrations of unlabeled estradiol. Dexamethasone, progesterone and R1881 (synthetic androgen) had no effect on the binding of [3H]-estradiol. The in vivo administration of estradiol resulted in increased nuclear binding of [3H]-estradiol as compared to vehicle treated controls. These results indicate that rat splenocytes possess specific, translocatable estrogen receptors which may be responsible for the observed modulation of the immune system.

Animals↗
PubMed1986

Estradiol-induced alteration in the immune system. II. Suppression of cellular immunity in the rat is not the result of direct estrogenic action.

Estradiol has been reported to suppress numerous cellular immune response. What is not known is how estradiol exerts this effect. In vivo administration of estradiol to male rats caused time-related immunomodulatory effects leading to enhancement of lymphocyte transformation while suppressing a mixed lymphocyte reaction (MLR) response. The suppression of the MLR response was not due to alterations in the ratio of helper and suppressor T cells, nor was it due to alterations in either cell viability or the number of cells in culture. Lymphocytes cultured in vitro with estradiol, however, fail to show any alteration in the responsiveness in either MLR or lymphocyte transformation assays. The suppressive effects of estradiol cannot be transferred from a primary MLR culture to a second MLR culture using the supernatants from the primary MLR culture. Lymphocytes from animals given estradiol in vivo show no alteration in the production of interleukin 2: added in vitro to primary MLR cultures, Interleukin 2 failed to restore full responsiveness to lymphocytes from animals treated in vivo with estradiol. These results suggest that estradiol acts indirectly to cause an alteration in the responsiveness of the regulatory cells of the cellular immune system.

Animals↗
PubMed1986

Beta adrenoceptor modulation of the generation of murine cytotoxic T lymphocytes in vitro.

The effects of stimulating beta adrenoceptors on lymphocytes during the generation of cell-mediated immunity were examined. In an in vitro system for the generation of murine cell-mediated cytotoxicity, addition of isoproterenol (10(-7) M), epinephrine (10(-6) M) or norepinephrine (10(-4) M) enhanced the number of lytic units generated compared to control cultures. This increase was blocked by dl-propranolol (5 X 10(-6) M). I-Propranolol (10(-11) to 10(-7) M) blocked the isoproterenol-induced increase in lytic units per culture, but d-propranolol (10(-11) to 10(-7) M) did not. Terbutaline (10(-5) M), a relatively selective beta-2 agonist, similarly augmented the generation of cell-mediated cytotoxicity, with the increase again blocked by propranolol. Butoxamine (5 X 10(-6) M), a beta-2 antagonist, but not atenolol (5 X 10(-6) M), a beta-1 antagonist, blocked the epinephrine-induced increase in cell-mediated cytotoxicity. Addition of phentolamine (5 X 10(-6) M) had no effect on the epinephrine-induced increase in lytic units per culture. However, in the presence of phentolamine, norepinephrine increased lytic units per culture to a greater degree than that seen with norepinephrine alone, suggesting a balance between positive beta effects and inhibitory alpha effects upon simultaneous alpha and beta stimulation. These data provide further evidence for an immunoenhancing role of beta receptor stimulation during the generation of immune responses.

Adrenergic alpha-Antagonists↗
PubMed1986

Human C81 (alpha-gamma) polymorphism: detection in the alpha-gamma subunit on SDS-PAGE, formal genetics and linkage relationship.

The molecular basis of human C81 (alpha-gamma) polymorphism could be elucidated by immunoprecipitation of human C81 allotypes and separation of the alpha-gamma and beta subunits on sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE) under nonreducing conditions. If the C8 molecules were completely reduced, C81 polymorphism was no longer detectable on SDS-PAGE. It is concluded that C81 variation depends on charge rather than molecular weight differences. Four C81 allotypes, the common A and B and two rare allotypes provisionally named A2 and B1, could be distinguished. The rare allotype A1 as detected by isoelectric focusing with subsequent C8 (alpha-gamma)-dependent functional overlay could no longer be visualized on SDS-PAGE. This allotype may therefore be elicited only in the intact C8 molecule. The beta-chain polymorphism named C82, probably also reflecting charge variation of the C8 molecule, could not be detected yet on SDS-PAGE. The distributions of C81 phenotypes and their respective allele frequencies were in good agreement with previously reported data. In the study of 30 families with 100 offspring, no deviation from the rule of at least four codominant alleles at one genetic locus was found. Linkage between C81 gene(s) and PGM1a encoded on chromosome 1 could be confirmed. The following estimates were obtained: (formula; see text) with S theta being the standard error of the maximum likelihood estimate theta. The new technique for allotyping human C81 at the subunit may provide a new tool for the differentiation of qualitative and quantitative variation of the eighth component of human complement.

Alleles↗
PubMed1985

Estradiol induced alterations of the immune system--I. Enhancement of IgM production.

Estrogens have been postulated as natural modulators of the immune system. In this study we have evaluated the effect of estradiol on in vivo immunoglobulin production in male rats. Administration of either a 75 microgram/kg or 750 microgram/kg dose of estradiol resulted in a dose-related increase of anti-sheep red blood cell antibody titers during a primary antibody response. These same animals when dosed with estradiol during a secondary antibody response showed an earlier appearance of the peak antibody titer in estradiol-treated rats as compared to controls. Rats dosed with estradiol only during the secondary antibody response period also showed a dose-related increase in Ab titer over control values but no shift in the time of appearance of the peak titer. Treatment of sera with 2-mercaptoethanol to evaluate IgG titers showed that 2-mercaptoethanol treatment both reduced the titer to control values and eliminated the estradiol-induced shift in the appearance of the peak antibody titer in rats given estradiol during the primary and secondary antibody response periods. Sera from animals dosed with estradiol during the secondary antibody response period only also showed titers reduced to control levels after 2-mercaptoethanol treatment of the sera. Estradiol-treated rats also had an increase in antibody titers to polysaccharide from Type III pneumococci, a T-cell independent antigen. While total antibody responses were increased following estradiol, there were no differences in the number of antibody-producing cells between control and estradiol-treated animals. The results of these studies suggest that estradiol exerts a direct effect on B cells resulting in increased synthesis of IgM antibodies. We cannot rule out, however, some modulation through regulatory T-cells.

Animals↗
PubMed1984

Possible in vivo modulation of the immune system by the leukotriene, LTB4. I. Delayed suppression of cellular immunity.

Leukotriene B4 (LTB4) is a potent mediator of inflammation. Recently, reports have indicated that LTB4 may affect lymphocyte function in vitro. Therefore, we examined the effect of LTB4 following intrapleural injection to determine if LTB4, released at an inflammatory site, would affect rat mononuclear cell function. LTB4 appeared to have little effect on mitogen-induced lymphocyte transformation nor was any direct mitogenic effect observed at concentrations ranging from 10(-6)-10(-12) molar. However, a marked inhibition of a one-way mixed lymphocyte reaction was observed upon in vitro culturing of lymphocytes from animals examined 72-96 hr after a single intrapleural injection of LTB4. We conclude that LTB4 released at inflammatory sites may play a role in modulating immune function but it appears not to be a direct effect but rather, although the evidence is circumstantial, an indirect effect.

Animals↗
PubMed1983

Suppression of mitogen-induced lymphocyte transformation in cigarette smokers.

Mitogen- and antigen-induced lymphocyte transformation was determined in peripheral blood lymphocytes from tobacco smokers and nonsmokers. Each group was evaluated by race, sex, and age subgroups. Male smokers as a group had depressed responses to phytohemagglutinin (PHA), concanavalin A, and pokeweed mitogen. The effect was most pronounced in all subjects on PHA stimulation. There was no apparent relationship to age or race. Antigenic stimulation of lymphocytes with mumps skin test antigen was not affected in any of the groups studied.

Adult↗
PubMed1983

Delayed hypersensitivity to mumps antigen in humans.

Sixty-one subjects, preselected for mumps sensitivity, were entered into a double-blind protocol to standardize Mumps Skin Test Antigen. Four lots of mumps antigen selected on the basis of in vitro potency tests were used. Four other antigens, Histoplasmin, Dermatophytin-O, Dermatophytin, and fluid tetanus toxoid were also tested; positive reactions for these four antigens occurred in 48, 68, 25, and 43% of individuals, respectively. The mumps lots exhibited delayed hypersensitivity with positivity ranging from 63 to 67% at 20 CFU/ml and 77 to 84% at 80 CFU/ml in the acceptable lots. Side effects were primarily local and minor in nature. Mumps Skin Test Antigen is a useful measure of the integrity of the immune system, but lacks complete specificity because of local dermal factors.

Adult↗
PubMed1983

Correlation of in vivo and in vitro expression of cell-mediated immunity to mumps skin test antigen.

The simplest functional assay of cell mediated immunity, skin testing, is not always possible to do in every patient. A variety of in vitro assays, including lymphocyte transformation (LT), have been developed as possible alternatives to skin testing. In this report studies were undertaken to determine whether LT induced by mumps skin test antigen (MSTA) correlated with skin test sensitivity. LT stimulated by MSTA was performed with cells obtained from 43 normal subjects. Each subject was subsequently skin-tested with up to four concentrations of MSTA. LT results correlated well with skin test reactions. Lymphocytes from all subjects were responsive in LT assays. A less pronounced correlation was observed between the concentration of MSTA used for skin testing and LT. The results of these experiments suggest that LT assays with MSTA provide an adequate substitute for MSTA skin tests.

Antigens, Viral↗
PubMed1983

Two types of dysfunctional eighth component of complement (C8) molecules in C8 deficiency in man. Reconstitution of normal C8 from the mixture of two abnormal C8 molecules.

Restoration of hemolytic activity was examined in sera from seven unrelated eighth component of complement (C8)-deficient subjects. The sera fell into two groups, depending on whether hemolytic activity was restored by the addition of the beta-chain (group 1) or the alpha-gamma-subunit (group 2) purified from normal human C8. Antigenic analysis of these sera by double-immunodiffusion using anti-human C8 confirmed previous findings of a dysfunctional C8 in the four sera of group 1 and established the presence of a different dysfunctional C8 in one of the sera of group 2 when tested at a high concentration. Further characterization of the dysfunctional C8 molecules in the two sera by sodium dodecyl sulfate-polyacrylamide gel electrophoresis demonstrated that group 1 sera were missing the beta-subunit and group 2 sera were missing the alpha-gamma-subunit of the C8 molecule. Sera from either of these two groups alone did not produce hemolysis in hemolytic plates containing sheep erythrocytes coated with antibody and complement components up to C7 (EAC1-7) and C9. When sera from the two groups were added to adjacent wells in the hemolytic plates, a zone of hemolysis developed between the wells. The contribution of C8 alpha-gamma from the sera of group 1 and of C8 beta from those of group 2 to the lysis of EAC1-7 in the presence of C9 was confirmed by the inhibitory effect of specific antibodies against the two C8 subunits. In experiments in which hemolytic activity was reconstituted by mixing sera from group 1 with sera from group 2, the serum source of C8 beta (group 2) was the limiting reagent. The dysfunctional C8 molecule in this serum was able to bind to EAC1-7. Chromatographic analysis demonstrated that the generation of hemolytic activity in the mixture of the two sera resulted from the reconstitution of the C8 molecule rather than the sequential action of the two C8 subunits.

Antibody Formation↗