Biomedical subjects

V Wahn

Publications and source records attributed to V Wahn.

At least 91 records · Page 5Linked to original sources

PubMed1991

Control of proven pulmonary and suspected CNS aspergillus infection with itraconazole in a patient with chronic granulomatous disease.

An 11-year-old boy with chronic granulomatous disease caused by cytochrome b deficiency developed right upper lung lobe aspergillosis. Intracerebral lesions developed on maximum doses of flucytosine and amphotericin B. Treatment with 16 mg/kg oral itraconazole was followed by a dramatic clinical improvement and almost complete disappearance of the intracerebral lesions. Plasma itraconazole levels were between 40 and 3440 ng/ml depending on concomitant medication. Toxicity was restricted to transient elevation of alkaline phosphatase and gamma glutamyl transferase. We conclude that further trials with itraconazole are justified in high risk patients in whom conventional therapy has failed.

Antifungal Agents↗

PubMed1991

Defective activation of the alternative pathway of complement in patients with homozygous C2 deficiency: studies in two unrelated families.

Selective homozygous deficiency of the second component of complement, C2, with increased susceptibility to infection was detected in five children of two unrelated families. Because the haemolytic activity of the alternative complement pathway (AP) was in the low normal range, we evaluated the AP activation pattern. Serum levels of factor B measured immunochemically and the haemolytic function of factor B were low normal. Levels of C3d were not increased. Activation products of factor B were undetectable indicating the absence of in vivo activation of AP. Activation of C3 in vitro by activators of the AP (zymosan A and lipopolysaccharide) was profoundly deficient in homozygous C2 deficiency while heterozygous carriers exhibited intermediate values. There was no correlation between serum levels of factor B and in vitro C3 activation. We conclude that defective AP activation may contribute to increased susceptibility to bacterial infections in some patients with homozygous C2 deficiency.

Child↗

PubMed1991

Granulocyte and granulocyte-macrophage colony-stimulating factors for treatment of neutropenia in glycogen storage disease type Ib.

Two children with glycogen storage disease type Ib associated with numerous recurrent bacterial infections as a result of neutropenia and neutrophil dysfunction were treated with recombinant human granulocyte colony-stimulating factor (G-CSF). One of the two patients was previously treated with recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF); therapy had to be discontinued because of severe local side effects. Both colony-stimulating factors at dosages of 3 and 8 micrograms/kg/per day, respectively, increased the average neutrophil counts from less than 300 cells/microliters to more than 1200 cells/microliters. Two subpopulations of neutrophils could be identified by their capacity to produce H2O2: one subpopulation generated H2O2 normally and a second was defective in H2O2 production. The doses of G-CSF effectively enhanced and maintained that subpopulation of neutrophils which produced normal amounts of H2O2. Moreover, these colony-stimulating factor-induced neutrophils demonstrated effective phagocytosis of zymosan particles and killing of staphylococci. Chemotaxis was decreased and could not be normalized by treatment with G-CSF. We conclude that maintenance treatment with G-CSF improved the quality of life in both patients: The number and severity of bacterial infections decreased markedly during treatment. Long-term treatment with G-CSF (12 and 10 months, respectively) was well tolerated, and no adverse clinical events were observed.

Adolescent↗

PubMed1991

Binding of cloned S-fimbriated E. coli to human buccal epithelial cells--different inhibition of binding by neonatal saliva and adult saliva.

Investigations were carried out on the adhesion of cloned S-fimbriated E. coli, labelled with fluoresceinisothiocyanate (FITC) to human buccal epithelial cells. Fluorescence microscopic analysis revealed binding of bacteria to 75-95% of epithelial cells. Inhibition experiments with fetuin, alpha 1-acid glycoprotein and N-acetyl neuraminic acid confirmed the specificity of bacterial binding to sialoglycoproteins. Further studies using saliva as an inhibitor resulted in a 4-5 times stronger binding inhibition by newborn saliva in comparison to adult saliva coinciding with a 4-5 times higher content of total N-acetyl neuraminic acid in samples of newborn saliva. In Western blot analysis sialoglycoprotein bands with a molecular weight greater than 200 kD reacting with wheat germ agglutinin (WGA), were only identified in samples of newborn saliva. These bands are classified as mucins on account of molecular weight and staining. These data suggest that saliva mucins could represent a major defense mechanism against bacterial infections at a stage of ontogeny where the secretory IgA-system is not yet developed.

Adult↗

PubMed1990

Detection of HIV RNA by in situ hybridization in peripheral blood mononuclear cells of seronegative children born to HIV-infected mothers.

Of 44 children born to human immunodeficiency virus (type 1) (HIV)-infected mothers, 11 have become seronegative. After the loss of maternal antibodies all children were analysed for several immunological functions and virological parameters in order to determine their HIV status. All children to date are clinically healthy and have normal immune functions. HIV-1 was detected by p24 antigen in one child, by in situ hybridization in nine children while viral cultures were all negative. These data suggest that the rate of vertical transmission of HIV-1 may be underestimated if seronegative children are considered to be not infected. They also suggest that molecular biological techniques are more sensitive than HIV antigen assay or viral cultures.

AIDS Serodiagnosis↗

PubMed1990

Identification of the heterozygotes for deficiency of the beta-subunit of the eighth component of complement by reduced levels of C8 beta and increased amounts of free C8 alpha-gamma.

Sera from obligate heterozygotes for deficiency of the C8 beta subunit of the eighth component of human complement (C8) were analyzed for the molecular composition of C8. The C8 alpha-gamma and C8 beta subunits were separated by SDS-PAGE, visualized by immunoblotting, and the resulting bands were quantitated by laser densitometry. The laser densitometric absorption data were set to 100 arbitrary units (AU) for both subunits of pooled normal human sera. The AU values of individual normal sera ranged from 45 to 150 AU for C8 alpha-gamma (median 99 AU) and from 45 to 140 AU for C8 beta (median 101), whereas the C8 alpha-gamma/C8 beta-ratio varied from 0.7 to 1.4. Sera from C8 beta-deficient heterozygotes differed, as expected, from the normal sera for the markedly reduced levels of C8 beta (20 to 90 AU, median 55 AU) and for the higher C8 alpha-gamma/C8 beta-ratio (1.3 to 3.5). High voltage agarose gel electrophoresis was used to separate free and C8 beta-bound C8 alpha-gamma. The migration of free and C8 beta-bound C8 alpha-gamma subunit was checked by hemolytic overlay gels and by second dimension SDS-PAGE and immunoblotting. Immunochemical evaluation of C8 alpha-gamma using this system revealed about 5-14% free C8 alpha-gamma in sera with normal C8 and higher levels, from 33-71%, in the C8 beta D heterozygous sera. Functional analysis confirmed the substantial increase of free C8 alpha-gamma in the heterozygous group. We conclude that the C8 in C8 beta D heterozygous sera is characterized by increased amounts of free C8 alpha-gamma due to reduced concentrations of the C8 beta subunit. This finding may help to identify individuals heterozygous for C8 beta deficiency.

Complement C8↗

PubMed1990

[Multicenter study of long-term management of HIV exposed and HIV infected children. Study organization and aims].

In order ot improve and standardize medical and psychosocial care for infants born to HIV-positive mothers, a prospective multicenter study has been initiated at 6 university hospitals in West-Germany in 1987. Aims of the study are: 1) determination of the rate of vertical HIV-transmission, relevant maternal risk factors and the clinical symptomatology of pre-or perinatally acquired HIV-infections, 2) identification of immunological and virological laboratory markers important for the verification and staging of HIV-infections in infants, 3) elaboration of an interdisciplinary approach to the care of HIV-infected children and their families, integrating medical care, social and psychological attendance.

AIDS Serodiagnosis↗

PubMed1990

[Allergic reactions in treatment with L-asparaginase. Significance of specific IgE antibodies].

The formation of specific IgE antibodies to L-Asp was studied in 27 children with ALL. Increased titers of specific IgE antibodies were significantly more frequent (p less than 0.001) prior to L-Asp infusions followed by allergic reactions than in those without reactions. After passive sensitization of basophile granulocytes of a healthy volunteer using patient's serum with the highest titers of specific IgE antibodies to L-Asp a significant release of histamine was observed after exposure of cells to L-Asp. In 1 of 8 patients with allergic reactions titers of specific IgE antibodies were elevated, while there was not detectable activation of the complement system. In conclusion, elevated titers of specific IgE antibodies to L-Asp are frequently detectable prior to L-Asp infusions which are associated with allergic reactions. In addition to activation of the classical complement pathway specific IgE antibodies and mediator release from mast cells may contribute to clinical symptoms. In a small number of patients this mechanism alone may be responsible for the allergic reaction.

Adolescent↗

PubMed1990

[A trial with high-dose gamma globulin therapy in 3 children with hyperbilirubinemia in rhesus incompatibility].

The influence of high-dose intravenous gammaglobulin (HDivGG) on the course of hyperbilirubinemia was investigated in three newborn infants with rhesus hemolytic disease. In addition to phototherapy and appropriate hydration all children received gammaglobulin (Polyglobulin N, Tropon-Cutter, Cologne, FRG) at a dose of 500 mg/kg body weight intravenously. All three infants showed a marked decrease in bilirubin levels after HDivGG. In two cases exchange transfusion could be avoided. In the third an elevated bilirubin level after blood exchange dropped following HDivGG, and a further exchange transfusion became unnecessary. The suspected effect of HDivGG in Rhesus incompatibility may be due to a blockade of Fc-receptors of the reticuloendothelial system, which prevents further hemolysis and bilirubin production. We propose, that the efficacy of this new mode of treatment should be evaluated in a controlled study.

Bilirubin↗

PubMed1989

[Recurrent meningitis in a familial defect of the beta-subunit of the 8th complement component].

Bacterial meningitides occurred in two members of a Yugoslavian family. In one case meningitis remained a singular event, Neisseria meningitidis being identified in the CSF. The second patient developed five episodes of recurrent purulent meningitis associated with petechiae and in one instance also with arthritis of the left knee but no causative germ was found. In both patients the Western blot technique revealed a defect of the beta-subunit of the eighth component of complement that was completely eliminated by purified C8. This proved that the C8 defect was isolated and that no other component was deficient.

Adolescent↗

PubMed1989

Familial deficiency of the seventh component of complement associated with recurrent meningococcal infections.

We describe an 11-year-old girl suffering from recurrent meningitis with a complete absence of the seventh component of complement (C7). Diagnosis was established by haemolytic titration and western blotting. The patient's serum lacked the 85 kDa C7 chain. Haemolytic activity of serum was reconstituted with either pooled normal human serum or with purified C7. The relatives (parents and one sister) had half-normal levels of both immunochemically and functionally determined C7, indicating a heterozygous state for C7 deficiency.

Blotting, Western↗

PubMed1989

Chemical and immunological characteristics of four different L-asparaginase preparations.

We studied the differences in protein composition and immunologic reactivity of two E. coli-derived L-asparaginase (l-Asp) preparations (I and II), Erwinia-Asp (III) and PEG-modified E. coli l-Asp (IV). On gel filtration, each of preparations I-III showed three major peaks at 100, 270 and 460 KD, all with enzyme activity, whereas PEG-Asp showed peaks at 35 and 220 KD. On SDS-PAGE one major subunit could be identified at 32 KD (I and II) or 40 KD (III), whereas PEG-modified l-Asp could only be detected by lowering the polyacrylamide concentration and gave a single band above 200 KD. Using a polyclonal rabbit antibody generated against preparation I, only the E. coli l-Asp preparations (I and II) formed precipitin lines on Ouchterlony double diffusion. After freezing and thawing, preparation IV also reacted with this antibody. In sera from patients treated with preparation I, antibodies (detected by ELISA) reacted with preparations I and II but not with preparations III and IV. These results indicate that Erwinia-Asp (III) and PEG-Asp (IV) are distinct from E. coli preparations (I and II) by molecular weight and immunological behavior. They also provide an experimental rationale for the use of Erwinia-Asp as well as PEG-Asp in E. coli Asp-sensitized patients.

Asparaginase↗

PubMed1989

[Lymphokine-induced suppression of erythropoiesis by normal T lymphocytes and retrovirus-associated lymphoproliferative disease].

Activation of genes for interleukin 2 (IL2) and its receptor by the tat gene product of the human retrovirus HTLV-I has been linked to the pathogenesis of adult T cell leukemia. In earlier studies we have demonstrated that IL2-induced inhibition of erythropoiesis is mediated by activated T-Lymphocytes expressing the IL2-receptor. We have now examined the role of activated T cells and interferon-gamma (IF gamma) in inhibition of normal erythropoiesis and in HTLV-I associated lymphoproliferative disease. T cells were activated by triggering of the antigen receptor complex with CD3 monoclonal antibody. Incubation with CD5 antibody recognizing a T cell epitope distinct from the antigen receptor served as a control. Supernatants derived from CD3 activated T cells generated in the presence of IL2 caused a dose-dependent suppression of erythropoiesis. Treatment of supernatant interferon-gamma neutralizing antibody caused a greater than 95% abrogation of inhibition. Next we investigated the mechanisms for acquired pure red cell aplasia in a patient with T gamma-lymphoproliferative disease (T gamma-LPD). Patient marrow erythroid progenitors were 17 +/- 9% of control and increased to 88-102% of control following marrow T cell depletion. Myeloid progenitors were normal. Patient suppressor T cells inhibited growth of autologous and allogeneic marrow erythroid but not myeloid progenitors and produced high titers of IF gamma. The inhibitory factor in patient T cell supernatant was acid labile and sensitive to trypsin, consistent with properties of IF gamma. Prior depletion of activated T cells abrogated the suppressive effect of patient T cell-derived supernatant.(ABSTRACT TRUNCATED AT 250 WORDS)

Anemia, Aplastic↗

PubMed1989

Elimination of l-asparaginase in children treated for acute lymphoblastic leukemia.

The elimination of l-asparaginase (l-Asp) was studied in 8 children treated for acute lymphoblastic leukemia according to the CoALL 82 protocol. The patients received four doses of l-Asp as a single agent during induction chemotherapy. We studied the elimination of l-Asp during the first infusion in 1 child, during the second in 3, during the third in 2 and during the forth in 2 children. Using Western blot technique and an experimental rabbit antibody to l-Asp, we were able to detect a single band at 32 kilodaltons (KD) in the serum of all patients between 4 and 36 h after infusion. The molecular weight remained unchanged and no other bands occurred during the time of observation. The detection limit of this method was calculated to 5 micrograms/ml using radial immunodiffusion. Incubation of l-Asp with pooled normal human serum caused no degradation of the enzyme during 48 h at 37 degrees C. Neither the total enzyme nor fragments were detectable in the urine of the patients collected during 8 h after l-Asp infusion. From these results we conclude that l-Asp is not cleaved by proteases in humans. The enzyme is most probably eliminated by the reticuloendothelial system.

Adolescent↗

PubMed1989

Successful HLA nonidentical bone marrow transplantation in three patients with the leukocyte adhesion deficiency.

Three consecutive patients with the severe phenotype of leukocyte adhesion deficiency characterized by a defective expression of LFA-1, Mac-1 (CR3), and p150.95 on leukocytes have received HLA partially incompatible bone marrow transplantation (BMT). The degree of HLA incompatibility between related donors and recipients was 2 HLA antigens in one and one full haplotype in the two others. Graft-v-host disease (GVHD) prophylaxis consisted in T-cell depletion of the bone marrow inoculum and a 60-day course of cyclosporin A. A first attempt led to autologous recovery in one patient. The second transplant in this patient and the first transplant in the two others led to stable partial engraftment of lymphocytes and phagocytic cells, as shown by expression of adhesion molecules (LFA-1, Mac-1) on leukocytes and by HLA typing and restriction fragment-length polymorphism studies using minisatellite probes. Although the level of mixed chimerism was lower in one patient (7% to 30% donor cells) and greater than 50% in the two others, recovery of lymphocyte and phagocytic cell functions was sufficient enough to allow the patient to lead a normal life, infection free in the three cases. These patients, now 57, 32, and 19 months post-transplant, are in good condition without any therapy. These results lead us to propose that the LFA-1 molecule plays a role in HLA-incompatible graft rejection, probably by mediating adhesion of cytotoxic T and non-T lymphocytes to their targets.

Antibody Formation↗

PubMed1988

Immunoblot analysis of the eighth component of human complement. Demonstration of subunits and detection of C8 alpha-gamma double and triple bands.

Using SDS-PAGE/immunoblot analysis of the eighth component of human complement, C8, we have been able to demonstrate an 85 kDa C8 alpha-gamma and a 62 kDa C8 beta subunit in normal human serum. Serum from an undiagnosed patient who presented undetectable hemolytic C8 activity possessed only the 85 kDa subunit, suggesting a defect in the C8 beta subunit. Serum of a patient with known C8 alpha-gamma deficiency possessed only the complementary 62 kDa subunit. Both sera used together were able to lyse antibody-sensitized sheep erythrocytes, whereas individual sera could not. Optimum conditions for C8 immunoblotting were determined using small amounts of serum or plasma, during low voltage electrophoresis and a sensitive staining technique (nitrobluetetrazolium/bromochloroindoxylphosphate). Using these conditions, the C8 alpha-gamma subunit was found to be composed of up to three bands, termed C8 alpha-gamma 1, -2 and -3. All three bands were found in pooled normal sera. Individual sera had at least the C8 alpha-gamma 2 and C8 alpha-gamma 3 bands. Two C8 beta-deficient sera from two unrelated patients exhibited only the C8 alpha-gamma 2 and C8 alpha-gamma 3 bands. We conclude that immunoblotting of C8 permits a detailed analysis of the molecular composition of this component and helps to establish a precise diagnosis in inherited C8 deficiencies.

Collodion↗

PubMed1988

Absence of complement receptor type 3 and lymphocyte function antigen 1 causing deficient phagocyte and lymphocyte functions.

We describe a patient with delayed umbilical cord detachment, recurrent bacterial infections, and inability to form pus, despite persistent leucocytosis. Immunofluorescence studies with specific monoclonal antibodies showed a severe deficiency in the expression of alpha-chains of the receptor for the C3bi fragment of C3, complement receptor type 3, and the lymphocyte function antigen 1 molecule, found on neutrophil, monocyte and lymphocyte membranes. These membrane antigen defects were responsible for abnormalities in adhesive cell functions. Polymorphonuclear leucocytes demonstrated a markedly reduced chemiluminescence response as well as an impaired nitroblue tetrazolium test and superoxide generation to a particulate stimulus (zymosan), while the responses to a soluble stimulus (phorbol myristate acetate) were normal. In addition, random migration und chemotactic response to zymosan-activated serum were impaired. The lymphocytes demonstrated abolished natural killer cell cytotoxicity as well as abnormal humoral immunity and a lack of antibody response to pertussis and tetanus antigens.

Antigens, Differentiation↗

PubMed1988

Beta-adrenoceptor density and resolution of high and low affinity state on B- and T-cells in asthmatic and non-asthmatic children.

Beta-adrenoceptor binding in lymphocytes of asthmatic and non-asthmatic children and healthy adult volunteers was investigated with the radioligand 125-iodocyanopindolol (ICYP). Binding studies were performed with 4 to 5 different concentrations of ICYP. Receptor density and affinity were calculated by Scatchard plots. Resolution of beta-adrenoceptors into those of high and low affinity state was obtained from inhibition curves with salbutamol using Hofstee plots. Receptor density in B-cell enriched fractions was two to three-fold higher than in T-cells for all patients and volunteers studied (P less than 0.025). No difference in beta-adrenoceptor density on B and T-cells occurred neither in age-matched asthmatic and non-asthmatic children nor in adult volunteers. The affinity of beta-adrenoceptors did not differ for B and T-cells nor for the patients or volunteers studied. However, when two distinct binding states for beta-adrenoceptor agonists were obtained using salbutamol displacement curves it appeared that beta-adrenoceptors on T-cells were at a higher affinity state compared to those on B-cells in asthmatic and non-asthmatic children, as well as in adults. Since the ability of an agonist to activate adenylate cyclase correlates closely with the amount of high affinity receptor state formed in the presence of the agonist, increased intrinsic activity of the beta-adrenoceptor agonist on T-cells may be postulated. In conclusion, age-related control groups and determination of the B/T ratio are necessary for interpretation of beta-adrenoceptor changes in bronchial asthma.

Adolescent↗