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Biomedical subjects

J Bartels

Publications and source records attributed to J Bartels.

At least 37 records · Page 2Linked to original sources
PubMed1996

Antileukoprotease inhibits stratum corneum chymotryptic enzyme. Evidence for a regulative function in desquamation.

The stratum corneum chymotryptic enzyme (SCCE) has been previously purified from human stratum corneum and resembles a chymotryptic serine endopeptidase involved in physiological detachment of corneocytes from human stratum corneum. From human stratum corneum two inhibitory activities of SCCE could be extracted. These were due to serine protease inhibitors already known to be present in human epidermis, antileukoprotease (secretory leukocyte protease inhibitor) and elafin (skin-derived antileukoprotease). The Inhibition of SCCE by antileukoprotease shows a hyperbolic, mixed type inhibition with an equilibrium dissociation constant of 63 n. Antileukoprotease also inhibits detachment of corneocytes from human plantar callus in vitro almost completely (>96%). In addition, elafin was shown to be a weak inhibitor for SCCE activity, and elafin significantly reduces the shedding of corneocytes. Thus, antileukoprotease, which is known to be produced by human keratinocytes, is likely to be the major physiological inhibitor of SCCE in the epidermis. It seems to be involved in the regulation of desquamation under physiological and pathophysiological conditions.

Aprotinin↗
PubMed1996

Human dermal fibroblasts express eotaxin: molecular cloning, mRNA expression, and identification of eotaxin sequence variants.

Recently we discovered and purified a novel beta-chemokine with eosinophil specific chemotactic activity from supernatants to long-term TNF-alpha stimulated dermal fibroblasts. Using degenerated specific oligonucleotides based on partial amino acid sequence data and a PCR protocol, we obtained different clones sharing high sequence homology with this novel chemokine and with human eotaxin cDNA. Semi-quantitative RT-PCR experiments using eotaxin-specific primers indicate low constitutive eotaxin mRNA expression in human dermal fibroblasts which is upregulated by IL-1 alpha and TNF-alpha within 6 hrs and modulated by IFN-gamma. While IL-1 alpha-induced eotaxin mRNA accumulation is transient, long-term stimulation with TNF-alpha resulted in a further increase of eotaxin mRNA.

Amino Acid Sequence↗
PubMed1996

Identification of an N-terminally truncated form of the chemokine RANTES and granulocyte-macrophage colony-stimulating factor as major eosinophil attractants released by cytokine-stimulated dermal fibroblasts.

Eosinophil (Eo) granule proteins and, rarely, intact Eos represent a characteristic histopathologic feature of the dermal part of affected tissue in atopic dermatitis and some allergic reactions. Dermal fibroblasts are a rich source of cytokines and inflammatory mediators; therefore, we have investigated whether these cells release Eo chemoattractants when stimulated with different stimuli. Eo-chemotactic activity was detected after stimulation of cells with TNF-alpha and IL-1, but not when phorbol ester, PHA, or medium alone was used. Biochemical characterization of Eo-chemotactic activity in supernatants of NF-alpha-stimulated cells revealed both heparin-binding and nonbinding activity. HPLC purification with subsequent N-terminal sequencing and mass spectrometric analysis showed that the heparin-binding Eo-chemotactic peak corresponded to the chemokine [Tyr-RANTES]66 that also contained [Ser-RANTES]68 as contaminant, whereas the nonheparin-binding activity was identified as granulocyte-macrophage CSF (GM-CSF) by the use of neutralizing Abs. [Tyr-RANTES]66 was found to show identical behavior in the chemotaxis assay system with respect to potency and efficacy as natural [Ser-RANTES]68. These findings support the hypothesis that dermal fibroblasts can play an important role in the recruitment of Eo by release of the chemokine RANTES together with GM-CSF.

Amino Acid Sequence↗
PubMed1996

Fibroblasts but not epithelial cells obtained from human nasal mucosa produce the chemokine RANTES.

RANTES is a chemokine that was already found in tissues obtained from nasal polyps of patients suffering from chronic polypous sinusitis. Its cellular origin is as yet unknown. The aim of this study was to investigate whether human nasal mucosa fibroblasts and epithelial cells are capable to produce RANTES. Fibroblasts and epithelial cells, obtained from healthy human nasal mucosa, were cultured. Expression of RANTES-mRNA and secretion of RANTES-protein in supernatants was investigated after stimulation with 50 ng/ml Tumour Necrosis Factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), interferon-g (IFN-gamma), lipopolysaccharide (LPS), phorbolymyristate acetate (PMA) and serum-free medium (SFM) for 24 h. Cultivated nasal fibroblasts either expressed RANTES-mRNA or secreted RANTES protein upon TNF-alpha, IL-1 beta and IFN-gamma stimulation. The amounts of RANTES-protein production ranged from 23 ng/ml (PMA) to 198 ng/ml (TNF-alpha). Nasal epithelial cells expressed RANTES-mRNA only after stimulation with PMA. Secretion of significant amounts of RANTES protein were not detected in the supernatants from nasal epithelial cells. We conclude that nasal fibroblasts but not epithelial cells could be a cellular source of RANTES in nasal mucosa or in secretions of patients suffering from diseases, where eosinophilic tissue infiltration represents a characteristic histopathological feature.

Cells, Cultured↗
PubMed1995

Antiprotease activity in urine of patients with inflammatory skin disorders.

Polymorphonuclear leukocytes contain well-defined proteolytic enzymes in their azurophilic granules that can be released into tissues during inflammation, producing a localized excess of proteases that causes a protease-antiprotease imbalance with subsequent tissue destruction. The antiproteolytic compounds of the epidermis, such as the protease inhibitors elafin and antileukoprotease, are thought to counteract the proteolytic tissue damage. We investigated the urine of patients suffering from inflammatory skin conditions (e.g., erysipelas, psoriasis) for the presence of urinary antiprotease activities. Purification of elastase-inhibitory activities from pooled urine samples by cation exchange high-performance liquid chromatography and preparative and analytical reverse-phase high-performance liquid chromatography yielded two different types of inhibitors. One was a cationic, acid-stable, and elastase-specific inhibitor of M(r) 6,000 by size-exclusion high-performance liquid chromatography. N-terminal amino acid sequence analysis of the first 28 residues showed identity with elafin, an elastase-specific inhibitor recently isolated from psoriatic scales. The second anti-protease activity was due to two forms of urinary bikunin, the inhibitory subunit of inter-alpha-inhibitor. Both bikunin fragments, with M(r) 4,000 and 16,000, were identified by N-terminal amino acid sequence analysis of the first 10 residues and were characterized by an antiproteolytic profile against human leukocyte elastase, cathepsin G, and trypsin. Urinary protease inhibitors may serve as diagnostic markers of inflammatory diseases.

Amino Acid Sequence↗
PubMed1995

Regulation of intracellular pH in the colonic epithelial cell line HT29 clone 19A.

Intracellular pH (pHi) of the colonic tumor cell line HT29 cl. 19A was studied by microspectrofluorometry using the pH-sensitive dye BCECF. Single cells within a confluent monolayer grown in a polarized manner on permeable supports were examined. An amiloride-sensitive Na(+)-H+ exchange and a stilbene-insensitive Cl(-)-HCO3- exchange mechanism have been identified in the basolateral membrane. This Na(+)-H+ exchange mechanism in the basolateral membrane is an acid extruder, whereas the Cl(-)-HCO3- exchanger is an acid loader. Both of these in the basolateral membrane located mechanisms are important for the maintenance of intracellular pH in HT29 cl. 19A cells.

Antiporters↗
PubMed1994

Tympanic membrane perforation in survivors of a SCUD missile explosion.

On February 25, 1990, an Iraqi SCUD missile exploded inside a building housing United States military personnel in Dhahran, Kingdom of Saudi Arabia. One hundred seventy-two individuals who were near the impact site at the time of the blast were interviewed and examined to determine blast injury to the ear. Tympanic membrane (TM) perforation was used as the clinical marker for aural blast injury. Thirty-four personnel had unilateral TM perforation and 28 had bilateral TM perforation. Eighty-six sustained sufficient injury to be hospitalized. Fifty-nine of hospitalized personnel (70%) had TM perforation. Of a total of 90 TM perforations, 39% were estimated to be 25% or less of the tympanic membrane surface area, 36% were 26% to 50%, 16% were 51% to 75%, and 10% were greater than 75%. Morphology of the perforations and estimated proximity to the blast were documented. Personnel distant from the blast, in open doorways or wearing headphones, had relative protection from TM perforation. Historic nuclear blast data were used to estimate the SCUD blast waveform based on measurements of the SCUD impact crater. A mathematical model based on the estimated waveform was validated against the actual field data by comparing the proximity and incidence of TM perforations in the SCUD missile explosion.

Adolescent↗
PubMed1992

Characterization, specificity, and IgV gene usage of anti-lymphocyte monoclonal antibodies from perinatal mice.

Previous studies have shown that CD5+ B cells predominate during development of the immune system and frequently secrete self-reactive antibodies, some of which appear to influence the development of the adult B cell repertoire. In addition, we now show that a high frequency of perinatally derived antibodies react with lymphocytes. Hybridomas derived from perinatal liver and splenic B cells and from spleens of adult BALB/c and C57BL/6 mice were screened by immunofluorescence on thymocytes. Anti-lymphocyte antibodies, all of the IgM isotype, were detected at a high frequency from perinatal fusions, but none were obtained from adult mice. These anti-lymphocyte mAbs were heterogeneous because they stained different subsets of peripheral T and B lymphocytes. Although the antigens recognized by these mAbs were heterogeneous with respect to their sensitivity to a variety of enzymes, 13 of the 19 mAbs recognized epitopes which were modulated by phosphatidylinositol-phospholipase C treatment. Inhibition experiments suggested that six of these 13 mAbs shared the same molecular specificity, and that they recognized the same T cell subset (62% of CD4+ and 98% of CD8+ cells). Furthermore, three of these mAbs immunoprecipitated the same 100 kDa protein from thymocytes (70 kDa in reducing conditions). The related molecular specificity of some anti-lymphocyte mAbs was also reflected by their restricted V gene usage. Three of the five mAbs specific for the 100 kDa protein used very similar or identical germline SM7 VH genes. In addition to using the same germline D and JH genes, they also exhibited identical VH-D-JH joins, despite originating from distinct fusions. Analysis of light chains also showed some restriction by preferential use of germline V kappa 4 and J kappa 5 genes. Together, these results suggest that the restricted antibody repertoire characteristic of mouse fetal and neonatal B cells is also reflected in the production of anti-lymphocyte antibodies. These B cells appear consistently in early development, use germline V genes, and express a characteristic VH-D-JH join.

Amino Acid Sequence↗
PubMed1992

Development and function of the early B cell repertoire.

The early B cell repertoire is characterized by extensive interconnectivity, autoreactivity and multispecificity. Our preliminary sequence analysis of some of the idiotype specific antibodies is beginning to provide molecular clues to explain the observed multireactivity and the expression of shared idiotypic determinants on immunoglobulins of early B cells. The VH gene rearrangements analyzed are typical of the early pre-B cell and CD5 B cell repertoire. Some of these include shared or identical CDR3 regions resulting from the use of germline VH, D and JH gene segments in the absence of N region addition. As previously described, the most D proximal VH genes are also used most frequently. Collectively these genetic restrictions, together with the lack of somatic mutation, suggest that the characteristic self reactivity of the early B cell repertoire is related to the expression of germline gene segments and limited use of diversification mechanisms. It has also been possible for the first time to isolate hybridomas secreting functional IgM molecules which use the most D proximal VH gene, VH81X. These antibodies and another example from the VH7183 family have a broad multireactivity pattern possibly because of the presence of an unusually high number of charged amino acid groups present in the VH region. These findings are preliminary and more extensive studies are needed to establish if these groups are responsible for the highly cross-reactive nature of these antibodies. Nevertheless, these unusual characteristics signify a unique role for antibodies expressing this VH gene during B cell development. It is also clear that the observed anti-lymphocyte reactivity, another feature of the newborn repertoire, is the result of the prevalence of B cells using similar if not identical VHDJH genes and DJH joins. The development of these B cells appears to occur consistently in early ontogeny and, again, are not found in conventional splenic B cells obtained from the normal adult. Understanding the functional significance of the early appearance of these antibodies may help to clarify and understand their role during development as well as in autoimmunity. We propose that the unique self reactive nature of the early repertoire provides a pattern within which self-assertiveness develops and results in the establishment of the adult repertoire. In doing so, dominant clones are established which may or may not be within, but whose selection and differentiation is directed by the CD5 B cell subset.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1990

Infective endocarditis in intravenous drug users: a comparison of human immunodeficiency virus type 1-negative and -positive patients.

In a study of 34 human immunodeficiency virus (HIV)-seropositive and 12 HIV-seronegative intravenous drug users with 40 and 14 episodes, respectively, of infective endocarditis (IE), there were no differences between groups in the presentation of IE. Staphylococcus aureus was the infecting microorganism in 75% of the HIV-positive patients and 86% of the HIV-negative patients. Overall survival for the HIV-positive patients was 85% compared with 93% for the HIV-negative patients. Ninety percent of patients with asymptomatic HIV infection survived, whereas 60% of patients in CDC group IV survived (P = .052). In contrast to New Jersey seroprevalence surveys showing HIV antibody in 10%-50% of intravenous drug users, HIV antibody seroprevalence rate in this selected population was 75%. IE in the HIV-seropositive intravenous drug user is essentially the same as in the seronegative user. However, patients with symptomatic HIV infection may be more likely to die from their IE. Intravenous drug users with IE have a greater-than-expected seroprevalence of HIV; the reason remains to be determined.

Adult↗
PubMed1983

[Hearing and equilibrium disorders in patients with neurosyphilis].

83 patients with neurosyphilis and 12 patients with latent syphilis underwent a cochleovestibular examination. Pathological changes were present in 54% of the patients with neurosyphilis. In the group of patients with latent syphilis functional changes could only be found in 25% of the patients. The greatest number of hearing disturbances occurred in persons suffering from general paresis, 65% were affected. Usually damage occurred in both ears. Specific topical diagnosis was often not possible although the results of the stapedial reflex indicated that peripheral cochlear lesions were present. In particular damage in the level of the high frequencies seemed to be prevalent. Disturbances of the vestibular system occurred in 25% of neurosyphilis patients. Most frequently lesions occurred in patients with cerebrospinal syphilis (40%). The comparison of subjective and objective symptoms of the vestibular system were very similar in most groups. As for the results presented it is suggested that a serological treponemal test should be undertaken in patients with non-specific disturbances of the vestibulo-cochlear system.

Adult↗
PubMed1978

[Contents of glycogen, glycolytic activity and contents of metabolites in the atrioventricular system of bovine hearts (author's transl)].

In the atrioventricular system (AVS) consisting of the compact node, the penetrating bundle and the branching bundles of about 250 bovine hearts there were made several studies: 1. In quickly removed and fixed specimens (distal AV-node, penetrating bundle) determination of a metabolic state with respect to glycogen, glucose, lactate, ATP, ADP, AMP, creatinephosphate, total creatine, gluc-6-phosphate, fructose-6-phosphate, fructose-1,6-diphosphate, dihydroxyacetonphosphate and pyruvate. 2. Determination of glycogen contents and glygolytic activity in AVS and its parts for ischemic times up to three hours. 3. The determination of metabolic contents in samples of connective tissue in atrium and ventricle of bovine hearts. The AV-nodes are poor in glycogen comparable with glycogen content of central nervous system and other ganglia. Penetrating bundles of Hiss and branching bundle belong after liver to the glycogen richest parenchyma of animal tissues. Even after ischemia of 3 h only a part of glycogen was recovered as lactate. The greater part of glycogen must be considered as a structural element of Hiss bundle and branching bundles of the ventricles.

Adenosine Diphosphate↗