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J Braun

Publications and source records attributed to J Braun.

At least 307 records · Page 17Linked to original sources
PubMed1997

Evaluation of lymphopenia among workers with low-level benzene exposure and the utility of routine data collection.

Whether low-level benzene exposure produces health effects is controversial. We used routinely collected data from our medical/industrial hygiene system to study 387 workers with daily 8-hour time-weighted exposures averaging 0.55 ppm. The cross-sectional repeated survey design included 553 unexposed workers. Lymphopenia is considered to be the earliest and most sensitive indicator of benzene toxicity. We found no increase in the prevalence of lymphopenia among benzene-exposed workers (odds ratio, 0.6; 95% confidence interval, 0.2 to 1.8), taking into account smoking, age, and sex. There also was no increase in risk among workers exposed 5 or more years (odds ratio, 0.6; 95% confidence interval, 0.2 to 1.9). Examination of other measures of hematotoxicity, including mean corpuscular volume and counts of total white blood cells, red blood cells, hemoglobin, and platelets, produced similar results. We conclude that risk of lymphopenia and other early indicators of hematotoxicity are not increased among workers in this study who were exposed to low levels of benzene.

Adolescent↗
PubMed1997

Highly polymorphic promoter regions of HLA DQA1 and DQB1 genes do not help to further define disease susceptibility in insulin-dependent diabetes mellitus.

HLA DQA1, HLA DQB1 genes confer susceptibility to insulin-dependent (type 1) diabetes mellitus (IDDM). Since variants of their upstream regulatory regions are linked to the exons, we investigated their promoter polymorphisms (QAP and QBP) by a combination of PCR-based typing protocols in 136 IDDM patients, 167 controls and 6 families with an IDDM proband to identify possible additional susceptibility markers. Of major interest for IDDM susceptibility are the promoter "splits" of HLA DQA1*0301 (QAP3.1 and QAP3.2) and HLA DQB1*0302 (QBP3.2 and QBP3.3). QAP 3.1 (96% in patients vs 98% in controls) and QBP3.2 (100% vs 99%) were found to be the most frequent promoter variants for HLA DQA1*0301 and DQB1*0302, respectively, whereas QAP3.2 and QBP3.3 were very rare. Furthermore the promoter "splits" were equally distributed on the respective exon alleles in all groups and cosegregated in families as expected. In conclusion, HLA DQ-mediated susceptibility and protection in IDDM is not restricted to the exon but extends to the promoter region without further defining the genetic risk.

Diabetes Mellitus, Type 1↗
PubMed1997

Usage of the coreceptors CCR-5, CCR-3, and CXCR-4 by primary and cell line-adapted human immunodeficiency virus type 2.

The chemokine receptors CCR-5 and CXCR-4, and possibly CCR-3, are the principal human immunodeficiency virus type 1 (HIV-1) coreceptors, apparently interacting with HIV-1 envelope, in association with CD4. Cell lines coexpressing CD4 and these chemokine receptors were infected with a panel of seven primary HIV-2 isolates passaged in peripheral blood mononuclear cells (PBMC) and three laboratory HIV-2 strains passaged in T-cell lines. The CCR-5, CCR-3, and CXCR-4 coreceptors could all be used by HIV-2. The ability to use CXCR-4 represents a major difference between HIV-2 and the closely related simian immunodeficiency viruses. Most HIV-2 strains using CCR-5 could also use CCR-3, sometimes with similar efficiencies. As observed for HIV-1, the usage of CCR-5 or CCR-3 was observed principally for HIV-2 strains derived from asymptomatic individuals, while HIV-2 strains derived from AIDS patients used CXCR-4. However, there were several exceptions, and the patterns of coreceptor usage seemed more complex for HIV-2 than for HIV-1. The two T-tropic HIV-2 strains tested used CXCR-4 and not CCR-5, while T-tropic HIV-1 can generally use both. Moreover, among five primary HIV-2 strains all unable to use CXCR-4, three could replicate in CCR-5-negative PBMC, which has not been reported for HIV-1. These observations suggest that the CCR-5 coreceptor is less important for HIV-2 than for HIV-1 and indicate that HIV-2 can use other cell entry pathways and probably other coreceptors. One HIV-2 isolate replicating in normal or CCR-5-negative PBMC failed to infect CXCR-4+ cells or the U87MG-CD4 and sMAGI cell lines, which are permissive to infection by HIV-2 but not by HIV-1. This suggests the existence of several HIV-2-specific coreceptors, which are differentially expressed in cell lines and PBMC.

Cells, Cultured↗
PubMed1997

Different BALF protein composition in normal children and adults.

UNLABELLED: Quantification of proteins in bronchoalveolar lavage fluid (BALF) is being performed increasingly, because of their potency in elucidating pathophysiological processes and their possible clinical relevance. STUDY POPULATION: 37 normal children (12 female, 25 male, mean age +/- SD 7.9 +/- 3.5 years, range 3-16 years) undergoing elective surgery for nonpulmonary illnesses and 16 healthy adults (all male, mean age +/- SD 24.7 +/- 2.6 years, range 20-28 years, 8 smokers, 8 nonsmokers) have been studied after approval by the ethics committees of both institutions. METHODS: BAL was performed with normal saline in the right middle lobe or one of its segments. Lavage volume was 15 x 20 ml in adults and 3 x 1 ml/kg in children. In adults the first aliquot was processed separately, 2 aliquots of the following were pooled (resulting in 8 different fractions) so that different lavage protocols could be calculated. The concentrations of the plasma-proteins alpha 1-proteinase inhibitor (alpha-1PI), alpha 2-macroglobulin (alpha 2PI), albumin (Alb) and of the locally released proteins myeloperoxidase (MPO), lactoferrin (Lf), elastase (Ela) and fibronectin (Fib) were determined in BALF using chemiluminescence immunoassays. RESULTS: The BALF concentrations of the plasma proteins were higher in children compared to adults. In contrast, concentrations of the locally released proteins were similar in both groups. Protein concentrations in the first recovered aliquot were different from the following in healthy adults with higher values of MPO, Lf and Ela and lower concentrations of alpha 1PI, alpha 2PI and Alb. Subsequent aliquots did not show a progressive dilution of these proteins with increasing lavage volumes. In smokers, BALF concentrations of albumin, alpha 1PI and MPO were higher compared to nonsmokers. CONCLUSION: BALF protein concentrations are different in normal children and adults. These results underscore the necessity to establish independent reference values for children, as could be demonstrated earlier with regard to BAL cell composition.

Adult↗
PubMed1997

CTLA4 alanine-17 confers genetic susceptibility to Graves' disease and to type 1 diabetes mellitus.

The genetic susceptibility to Graves' disease and type 1 (insulin-dependent) diabetes mellitus is conferred by genes in the human leukocyte antigen region on the short arm of chromosome 6, but several other genes are presumed to determine disease susceptibility. Among those candidate genes is the cytotoxic T lymphocyte antigen 4 (CTLA4) located on chromosome 2q33 in man. We investigated the distribution of the CTLA4 exon 1 polymorphism (49 A/G) in Graves' disease and IDDM. This dimorphism at codon 17 results in an amino acid exchange (Thr/Ala) in the leader peptide of the expressed protein and was analyzed by PCR, single strand conformation polymorphism, and restriction fragment length polymorphism analysis in 305 patients with Graves' disease, 293 patients with IDDM, and 325 controls. Patients with Graves' disease had significantly more Ala alleles than controls, both as homozygotes (21% vs. 13%) and as heterozygotes (53% vs. 46%), and less Thr as homozygotes (26% vs. 42%; P < 2 x 10(-4). The phenotypic frequency of Ala-positive patients (73%) was significantly higher than of controls (58%; P = 10(-4); relative risk = 2). Patients with IDDM also had significantly more Ala alleles as homozygotes (19%) or heterozygotes (50%; P = 0.01). In conclusion, an alanine at codon 17 of CTLA4 is associated with genetic susceptibility to Graves' disease as well as to IDDM.

Abatacept↗
PubMed1997

Codon 17 polymorphism of the cytotoxic T lymphocyte antigen 4 gene in Hashimoto's thyroiditis and Addison's disease.

Endocrine autoimmune disorders share susceptibility and resistance factors of the human leukocyte antigen system on the short arm of chromosome 6, but other gene loci also contribute to predisposition and protection. Because the cytotoxic T lymphocyte antigen 4 (CTLA4) alanine-17 encoded by the CTLA4 gene on chromosome 2q33 confers susceptibility to Graves' disease, as well as to type 1 (insulin-dependent) diabetes mellitus, we investigated this dimorphism in the other endocrine autoimmune disorders: Hashimoto's thyroiditis and Addison's disease. We analyzed the CTLA4 exon 1 polymorphism (49 A/G) in 73 patients with Hashimoto's thyroiditis, 76 with Addison's disease, and 466 healthy controls. This dimorphism corresponds to an aminoacid exchange (Thr/Ala) in the leader peptide of the expressed protein. CTLA4 alleles were defined by PCR, single-strand conformational polymorphism analysis, and restriction fragment length polymorphism analysis using BbvI. Patients with Hashimoto's thyroiditis had significantly more Ala alleles than controls, both as homozygotes (22% vs. 15%) and heterozygotes (53% vs. 46%), and less Thr than controls as homozygotes (25% vs. 39%), P < 0.04. The phenotypic frequency for Ala was significantly higher in patients (75%), compared with controls (61%), P < 0.03. Patients with Addison's disease did not differ significantly from controls, but those carrying the suceptibility marker, human leukocyte antigen DQA1*0501, were significantly more CTLA4 Ala17 positive than controls with the same DQA1 allele (P < 0.05). In conclusion, an alanine at codon 17 of CTLA4 confers genetic susceptibility to Hashimoto's thyroiditis, whereas this applies only to the subgroup of DQA1*0501+ patients with Addison's disease.

Abatacept↗
PubMed1997

HIV-1 gp120: a novel viral B cell superantigen.

The envelope glycoprotein of the human immunodeficiency virus (HIV-1), gp120, has recently been characterized as a novel immunoglobulin superantigen (Ig-SAg) [1,2]. Analogous to the interaction of SAgs with T cells, gp120 binds to an unusually large proportion of immunoglobulins (lgs) from HIV-uninfected individuals; most, if not all of these Igs are members of the VH3 family [3]. Functionally, gp120 preferentially stimulates VH3 B cells in vitro. This stimulation correlates with an in vivo VH3 activation during HIV infection. Curiously, this initial activation is followed by a subsequent depletion of VH3-expressing B cells as individuals progress to AIDS. In this article we will review our current understanding of the superantigenic properties of HIV gp120. Specifically we will focus on structural aspects of the binding interaction. on the ontological development of these superantigen-binding antibodies, and on potential roles that this unconventional Ig-pathogen interaction might play in the pathogenesis of HIV-induced disease.

B-Lymphocytes↗
PubMed1997

Nested polymerase chain reaction strategy simultaneously targeting DNA sequences of multiple bacterial species in inflammatory joint diseases. I. Screening of synovial fluid samples of patients with spondyloarthropathies and other arthritides.

OBJECTIVE: Bacteria play a crucial pathogenetic role in Lyme arthritis (LA), reactive arthritis (ReA), other forms of spondyloarthropathy (SpA), and possibly in undifferentiated oligoarthritis (uOligo). Polymerase chain reaction (PCR) technology has been applied to detect bacterial DNA of individual microbes in synovial fluid (SF) of patients with arthritides. We screened for DNA sequences of 8 bacterial species simultaneously in SF of patients with inflammatory joint disease. METHODS: We examined 104 SF samples of 96 patients with ReA (n = 13), undifferentiated SpA (uSpA, n = 10), uOligo (n = 50), juvenile chronic arthritis (JCA, n = 13), and rheumatoid arthritis (RA, n = 10). A nested PCR approach was developed to detect DNA sequences of 8 bacteria: Chlamydia trachomatis, C. pneumoniae, Yersinia enterocolitica, Salmonella enteritidis, Campylobacter jejuni, Shigella flexneri, Klebsiella pneumoniae, and Borrelia burgdorferi. The detection limit was determined at 10 bacterial/sample. Serology and lymphocyte proliferation assay were done in parallel in most patients. RESULTS: In 12 cases bacterial DNA of B. burgdorferi (n = 7), C. trachomatis (n = 2), C. jejuni (n = 2), and C. pneumoniae (n = 1) was detected in patients with uOligo (n = 9) and JCA (n = 3), while no evidence of bacterial DNA was found in patients with ReA, uSpA, and RA. Shigella flexneri DNA was detected in 4 cases, but the significance of this finding remains uncertain due to the high sequence homology of this species with Escherichia coli. DNA of Y. enterocolitica, S. enteritidis, or K. pneumoniae was not found. A positive serologic response was found in 7/9 PCR positive patients. In 11/96 cases antibodies to 2 or more bacteria were found in parallel (11.5%). Antigen specific lymphocyte proliferation was observed in 5/9 PCR positive patients. CONCLUSION: Bacterial DNA was detected in peripheral joint of patients with uOligo and JCA, but not in ReA, uSpA, or RA in this study. The detection of bacterial DNA in synovial material by PCR technology gives useful diagnostic information, especially when antibodies against several microbes are present or antibodies are not detectable. Failure to detect bacterial DNA in patients with ReA and uSpA with longstanding disease suggests that in later stages autoimmune mechanisms may operate.

Adolescent↗
PubMed1997

Nested polymerase chain reaction strategy simultaneously targeting DNA sequences of multiple bacterial species in inflammatory joint diseases. II. Examination of sacroiliac and knee joint biopsies of patients with spondyloarthropathies and other arthritides.

OBJECTIVE: Bacteria play a crucial pathogenetic role in reactive arthritis (ReA) and other forms of spondyloarthropathy (SpA) and in Lyme arthritis. Although there is evidence of local persistence of bacterial antigens no definitive method revealing microbes in peripheral joints has been established. We detected DNA of individual bacteria in synovial material by PCR. Applying molecular technology we screened simultaneously for 8 bacterial genomes in arthritis and sacroiliitis. METHODS: Sacroiliac (SI) biopsy specimens taken from the SI joint of 8 patients with ankylosing spondylitis (AS, n = 5) and undifferentiated SpA (uSpA, n = 3) by computed tomography guided biopsy were investigated for presence of bacterial DNA. Similarly, synovial membrane samples obtained by office arthroscopy from 15 patients with ReA (n = 5), uSpA (n = 3), undifferentiated oligoarthritis (uOligo, n = 3), and rheumatoid arthritis (RA, n = 4) were screened. Nested PCR was performed for DNA of the following bacteria: Chlamydia trachomatis, C. pneumoniae, Yersinia enterocolitica, Salmonella enteritidis, Campylobacter jejuni, Shigella flexneri, Klebsiella pneumoniae, and Borrelia burgdorferi. RESULTS: No bacterial DNA was found in the SI biopsies of patients with uSpA and AS. DNA of B. burgdorferi (n = 2) and C. trachomatis (n = 1) was detected in 3 patients with uOligo, but not in patients with ReA or RA. DNA of other microbes including K. pneumoniae was not found. Patients' mean disease duration was 5.3 years (2 mo-8.4 yrs). CONCLUSION: We found bacterial DNA in peripheral joints of patients with uOligo, while in patients with ReA, AS, and uSpA no bacterial DNA was detected in peripheral or SI joints. The failure to detect bacterial DNA in patients with SpA suggests autoimmune mechanisms operate in later stages of disease.

Adult↗
PubMed1997

[Disturbed neutrophil activation in pneumonia during medicinal immunosuppression].

BACKGROUND: In medically immunosuppressed patients with pneumonia, the BAL cell differential and neutrophils secretion products were determined and compared to patients with pneumonia without defined immunodeficiency in order to define a possibly deficient neutrophil function. PATIENTS AND METHODS: Forty-eight medically immunosuppressed patients were studied: 24 pts. after renal transplantation receiving threefold immunosuppression (cyclosporine, azathioprine, prednisolone), 14 pts. with non-Hodgkin-lymphoma receiving polychemotherapy and 10 pts. with rheumatologic disorders (rheumatoid arthritis n = 3, M. Wegener n = 5 und SLE n = 2) receiving cyclophosphamide or methotrexate. For comparison, 116 patients without defined immunodeficiency and pneumonia and 16 healthy adults were studied. In addition to the cell differential the BALF concentrations of the neutrophil degranulation products myeloperoxidase (MPO) and lactoferrin were determined using immunoluminometric assays. For identification of microorganisms semiquantitative cultures were used. RESULTS: Neutrophilia > 5% in BAL was present in only 36% of the immunosuppressed pts. in contrast to 91.3% of the immunocompetent pts. (p < 0.01). The same pathogen was found in 14 pts. of each group, so that a pathogen matched comparison was possible. The neutrophil percentage and the BALF concentration of lactoferrin was significantly lower in the immunosuppressed group. In blood there was no difference with regard to the neutrophil count between the groups. CONCLUSIONS: BAL characteristics of immunosuppressed pts. are different from those of immunocompetent pts. with pneumonia. The pathogen-matched comparison proved that this is not due to different pathogens. Medically immunosuppressed patients with pneumonia exhibit a disturbed neutrophil recruitment. A neutrophil percentage < 5% in BAL of medically immunosuppressed patients does not preclude a bacterial infection.

Adult↗
PubMed1996

[Hypertension caused by licorice consumption].

In a 38-year-old woman who was hospitalized because of hypertension and hypokalaemic alkalosis, the intake of liquorice (200 g per day) was proven to be the cause. A liquorice provocation test produced all the expected clinical and biochemical abnormalities. Some kinds of liquorice contain glycyrrhetic acid which inhibits the enzyme 11-beta-hydroxysteroid dehydrogenase (e.g. in the kidney) leading to decreased transformation of cortisol into cortisone. The mineralocorticoid action of cortisol causes a drop in serum potassium and an increase in serum sodium concentration, together with a metabolic alkalosis, which in the patient described led to retention of water resulting in weight increase and hypertension.

11-beta-Hydroxysteroid Dehydrogenases↗
PubMed1996

Productive and persistent infection of human thymic epithelial cells in vitro with HIV-1.

Infection with HIV-1 results in a disruption of the thymic microenvironment and the presence of HIV-1 in thymic epithelial cells has been demonstrated in vivo. In the present study, we examined the susceptibility of a highly enriched culture of thymic epithelial cells (TEC) to infection in vitro by HIV-1 laboratory strains and primary isolates. Replication in TEC is shown to depend on the virus and on the expression of CD4 molecules that are found to be expressed at a low density on the plasma membrane. Our results are consistent with infection of TEC controlled by the efficiency of the interactions between the envelope glycoprotein of the virus and the cell surface molecules. As a consequence, certain HIV-1 viruses induce a productive and persistent infection in TEC without damaging the cells. Altogether these results support the idea that TEC may act as a reservoir for HIV-1 in the thymus but are probably destroyed by an indirect mechanism involving infection of thymocytes.

Cells, Cultured↗
PubMed1996

Human immunodeficiency virus-1 (HIV-1) gp120 superantigen-binding serum antibodies. A host factor in homosexual HIV-1 transmission.

HIV-1 gp120 is an immunoglobulin superantigen which can bind to preimmune serum Ig. We hypothesize that levels of such preimmune antibodies vary in the population and might affect host resistance or susceptibility to viral transmission. This study tests two predictions: (a) levels of preimmune anti-gpl20 Igs are a polymorphic trait; and, (b) these levels are correlated with resistance or susceptibility to HIV-1 transmission. The first prediction was confirmed in a longitudinal study of a low-risk seronegative population. In this group, levels of both endogenous anti-gpl20 IgM and IgG varied widely, but were characteristic and stable for each individual. The second prediction was addressed in a study of participants of the Multicenter AIDS Cohort Study, in which men "susceptible" and "resistant" to HIV infection were identified based on numbers of sexual partners and eventual seroconversion. Specimens consisted of archival sera obtained > 2 yr before seroconversion. Men in the susceptible population (low-risk seroconverters) were distinguished by low levels of anti-gpl20 IgG. We conclude that the level of preimmune anti-gpl20 IgG is a polymorphic population trait, and low levels are a potentially specific and significant factor in homosexual transmission of HIV infection.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Effect of sacral and iliac instrumentation on strains in the pelvis. A biomechanical study.

STUDY DESIGN: This study is a biomechanical study on human cadaver pelves using strain gauges to measure strains at different locations in response to different load states. OBJECTIVES: To examine the changes in strains, at different sites on the pelvis, and after instrumentation of the lumbosacral joint and the lumbosacroiliac joint. SUMMARY OF BACKGROUND DATA: Pelvic girdle pain after long instrumented fusions to the sacrum has been described and studied along with sacroiliac and pubic instability. Fractures of the pelvic rami or the iliac wing have been reported in patients after surgical fusions that incorporated the sacrum and sacroiliac joint. METHODS: Pelves with lumbar spine attached had three axis rosette strain gauges cemented to specific sites on the pelves (ilium [correction of ileum] and rami). Specimens were tested in different configurations involving lumbosacral and sacroiliac instrumentation. Iliac bone harvest was also tested. Strain values were computed and compared for each configuration. RESULTS: The "Galveston" and "sacral" instrumentation configurations caused significant stress shielding in pelves under all compression loads applied. Axial rotations on the instrumented specimens caused higher strains at all sites. Harvesting of bone from the ilium did not alter the strains seen at the different sites. CONCLUSIONS: This study suggests significant stress shielding provided by sacro and sacroiliac instrumentation systems, supporting the possibility of development of device-related osteopenia that may predispose patients to late, insufficiency-type fractures as their activity increases. The rigid instrumentation of the lumbosacral spine was found to increase the stress during torsion, which may lead to failure during activity.

Adult↗
PubMed1996

Phage display cloning and characterization of an immunogenetic marker (perinuclear anti-neutrophil cytoplasmic antibody) in ulcerative colitis.

Ulcerative colitis (UC) is genetically associated with a marker serum Ab (pANCA), identified by its reactivity with a neutrophil Ag. This study utilized phage display technology to clone and characterize pANCA, which has resisted conventional isolation strategies. Since spontaneous pANCA-secreting B cells are detectable in UC lamina propria lymphocytes, this cell source was used to construct a complete IgG1-kappa Ig library. Selection of phage by panning with fixed neutrophils yielded a 195-fold enrichment after five cycles of panning. BstN1 fingerprinting of the enriched library revealed two predominant clones, and DNA sequencing demonstrated highly homologous heavy and light chain variable region segments. Clones were reengineered to express soluble Fab, and neutrophil binding was verified by ELISA. Detailed studies with the two recombinant Fabs, NANUC-1 and -2, validated their identity with serum pANCAs by the criteria of immunofluorescence, confocal microscopy, and DNase I sensitivity. NANUC-1 and -2, like serum UC-pANCA, lack reactivity with previously characterized ANCA-reactive neutrophil proteins and thus detect a novel Ag(s). This study demonstrates the feasibility of selecting phage display Ab libraries on uncharacterized biologic substrates to isolate marker Abs of pathogenic importance.

Amino Acid Sequence↗