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P Entzian

Publications and source records attributed to P Entzian.

At least 19 recordsLinked to original sources
PubMed2001

Reduced T-cell receptor CD3zeta-chain protein and sustained CD3epsilon expression at the site of mycobacterial infection.

Control of mycobacterial infection by the cellular immune system relies both on antigen-presenting cells and on T lymphocytes. The quality of an effective cellular immune response is dependent on functional signal transduction residing in the cytoplasmic tails of the T-cell receptor CD3 components. In order to investigate potential effects of mycobacteria on T-cell receptor signalling, we examined the protein expression of T-cell signal transduction molecules (CD3zeta, ZAP-70, p59fyn, p56lck). In Western blots of peripheral blood mononuclear cells of Mycobacterium tuberculosis infected patients, only the CD3zeta-chain showed a marked reduction in protein expression. To investigate the situation in situ, immunoenzymatic and immunofluorescence stainings for CD3epsilon and CD3zeta expression were performed on sections of normal lymphoid tissue, M. leprae infected and sarcoid tissue. CD3epsilon and CD3zeta expression were similar with respect to intensity, localization and the number of cells stained in normal lymphoid tissue and in sarcoid granulomas. In contrast, the granulomas of M. leprae infected tissues showed a significantly reduced expression of CD3zeta compared to CD3epsilon. Using double immunofluorescence analysis, virtually no CD3zeta expression could be detected in comparison to the CD3epsilon expression in the lesions. Apparently, mycobacteria are capable of significantly reducing CD3zeta-chain expression, which may be restored by cytokines. IL-2-enhanced zeta-chain expression and T-cell effector functions, defined by interferon-gamma release, in M. tuberculosis-specific and human leucocyte antigen-DR restricted CD4+ T cells isolated from granuloma lesions from patients with pulmonary tuberculosis. Because CD3zeta is essential for CD3 signalling and for eliciting T-cell effector functions, reduced CD3zeta protein expression could result in altered signal transduction and inefficient T-cell effector functions. Alternatively, reduced CD3zeta-chain expression may protect T cells from repetitive TCR stimulation associated with anergy or apoptosis.

CD3 Complex↗
PubMed2001

Interleukin-12 as successful adjuvant in tuberculosis treatment.

Interleukin-12 (IL-12) proved to be an effective and successful adjuvant to a standard antituberculotic medication in a patient suffering from progressive clinical tuberculosis (TB). IL-12 is a potent enhancer of interferon-gamma production which is necessary for killing intracellular bacteria like mycobacteria. This patient's TB was progressive, although sensitivity to first-line antituberculotics was proven and medication was given as directly observed therapy over more than 8 months. The 3-month adjuvant therapy with IL-12 significantly and convincingly improved results. It is believed that this case, the first in the literature to describe adjuvant interleukin-12 therapy in tuberculosis, strongly encourages the study of adjuvant interleukin-12 therapy on a more systematic basis.

AIDS-Related Opportunistic Infections↗
PubMed1998

Comparative study on effects of pentoxifylline, prednisolone and colchicine in experimental alveolitis.

Neutrophil alveolitis is a hallmark of cryptogenic fibrosing alveolitis (CFA), known for its poor prognosis. Corticosteroids, as the remedy of choice, are ineffective in a majority of patients. More and more evidence indicates that pentoxifylline (POF) could be an effective therapeutic alternative. Furthermore, colchicine has been proposed for therapy of CFA for many years now. We conducted an experimental study comparing the efficacy of these drugs in preventing neutrophil alveolitis in vivo. Alveolitis was induced in male rats by intratracheal instillation of bleomycin. Treatment consisted of daily injections of POF i.p., colchicine i.p., or prednisolone i.m. After 8 days the animals were sacrificed and body weights, cell differentials in BAL, amount of proliferating interstitial cells as determined by KI-67 staining of lung tissue, and collagen concentrations in lungs were determined. Bleomycin instillation was followed by a significant weight loss in the animals, a neutrophil alveolitis in BAL and an increased amount of proliferating cells in lung interstitium. POF significantly inhibited any of the parameters named, whereas prednisolone and colchicine had little effect. Data cannot be applied directly in human disease. There are however many similarities between CFA and bleomycin-induced lung injury and alveolitis. We conclude that POF is an effective inhibitor of neutrophil alveolitis, whereas neither colchicine nor prednisolone exerted significant influence in our model. We suggest POF effects should be further investigated regarding anti-inflammatory and anti-fibrotic properties.

Animals↗
PubMed1998

Differences in the anti-inflammatory effects of theophylline and pentoxifylline: important for the development of asthma therapy?

Antiasthma drugs are now being re-evaluated for their anti-inflammatory effects. Theophylline is an immunomodulator; however, weak effects and the narrow therapeutic window make it a controversial drug. We compared the immunomodulatory potencies of theophylline with those of the xanthines pentoxifylline (POF) and A802715. Using a whole-blood, cell-culture system, we studied the effects on the release of tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), and interleukin-6 (IL-6) in six healthy subjects, and, in granulocyte suspensions, the effects on the release of reactive oxygen species (ROS). We also studied the influence of a 14-day treatment with theophylline or POF on the release of the cytokines named above in 14 asthmatics. We found that equimolar concentrations of A802715 most effectively inhibit ROS generation, followed by POF; the effects of theophylline were weakest. A802715-inhibited release of TNF-alpha was four times as potent as that of theophylline, and POF two times as potent. Inhibition of IFN-gamma by A802715 was three times as potent, and by POF two times. Neither drug influenced IL-6 release. After a 14-day treatment of asthmatics, POF proved to inhibit TNF-alpha release more effectively (by 44.3%) than theophylline (7.5%). It is concluded that study of xanthine derivatives in asthmatics might help the development of asthma therapy. POF seems to be an especially promising candidate.

Adult↗
PubMed1998

[Limits of beryllium detection with laser microprobe mass spectrometry (LAMMS)].

Search for beryllium (Be) in tissues or urine in suspected beryllium disease is often disappointing due to inferior sensitivity of the methods employed. We evaluated the clinical use of laser microprobe mass spectrometry (LAMMS) for measurement of Be and detected the metal to a minimum concentration of 1 microM. We then investigated the biological relevance of this concentration. We looked at the alveolar macrophages in 7 patients subsequent to an incubation period of 24 h as well as peripheral blood mononuclear cells (PBMNC) and various cell lines with and without addition of beryllium sulfate (BeSO4). We also investigated skin biopsies of two patients 28 days after intracutaneous injections of BeSO4 (beryllium skin testing) and alveolar macrophages of A/J mice at various time intervals after a beryllium sensitisation protocol and a single intratracheal injection of BeSO4 (maximum interval: 15 weeks). Be was not defectable in native patient alveolar macrophages (AM), but in 6 of 7 cases after coincubation with BeSO4. There was no significant Be signal in any analysed PBMNC sample or cell line--even after coincubation with Be--or in the skin probes. Murine AM, however, had incorporated significant amounts of Be, which were detectable until the end of the experiments 15 weeks later. We conclude that concentrations of Be in acute disease (here, inoculation of Be in mice) exceed 1 microM and are thus detectable by LAMMS. On the other hand, concentrations in chronic processes (in this cosar, skin testing) are below the detection limits of LAMMS. Further results suggest compartmentalisation of the immune processes induced by Be because the alveolar macrophages were able to incorporate Be while PBMNC were not and because AM--at least in the animal experiments--seem to store Be intracellularly.

Adult↗
PubMed1997

Antiinflammatory and antifibrotic properties of colchicine: implications for idiopathic pulmonary fibrosis.

The ancient drug colchicine has repeatedly been proposed as a novel drug for therapy of pulmonary fibrosis. The present study was undertaken to add to the knowledge on colchicine's antiinflammatory and antifibrotic properties and thus help determine its actual rank in the treatment of pulmonary fibrosis. In vitro cell culture experiments with stimulated and unstimulated normal donor peripheral blood mononuclear cells (PMNC) and a human lung fibroblast cell line (WI-38) were used to determine the effects of colchicine on PMNC cytokine release (interleukin-6 and tumor necrosis factor-alpha) as well as on fibroblast proliferation and collagen synthesis rates. Reverse transcriptase polymerase chain amplifications of alpha 1 (III) collagen were done to detect collagen messenger ribonucleic acid (mRNA) expression. Colchicine did not significantly modulate tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) release of PMNC. Colchicine inhibited fibroblast proliferation and total collagen synthesis significantly at concentrations obtainable in serum in vivo. Transcription of the alpha 1 (III) collagen gene into mRNA continued under colchicine. We conclude that colchicine is a potent in vitro inhibitor of fibroblast functions in terms of proliferation and collagen synthesis. The mechanism of collagen inhibition is more likely an inhibition of cellular collagen secretion than a switch off of collagen mRNA transcription. On the other hand, although colchicine is known to inhibit many leukocyte functions, it is a poor inhibitor of cytokines known to be important for fibrogenesis (e.g. IL-6, TNF-alpha, IL-1, platelet-derived growth factor, and transforming growth factor-beta). This makes colchicine, at least from a theoretical standpoint and as concluded from in vitro studies, a preferable candidate for a combined therapeutic strategy.

Cells, Cultured↗
PubMed1997

Pentoxifylline in treatment of sarcoidosis.

The optimal therapy for sarcoidosis remains unclear. Most patients show a short-term response to corticosteroid therapy, but they have to face the risk of significant side effects. Because tumor necrosis factor alpha (TNF) plays a critical role in granuloma formation and sustenance as well as in the progression of sarcoidosis, we investigated pentoxifylline (POF), which exerts TNF-inhibitory activity, as a therapeutic agent in active pulmonary sarcoidosis. Twenty-three previously untreated patients with documented disease progression during the preceding 3 mo were treated with POF (25 mg/kg daily) and followed for 6 mo of therapy. Two patients were lost to follow-up, and three patients discontinued POF therapy because of gastrointestinal side effects; 18 patients were thus evaluated. Eleven patients improved, seven remained stable and, most importantly, none deteriorated. Lung function tests-DL(CO), Pa(O2) and Pa(O2)[exercise]-were significantly improved in the patient group as a whole and increased in a highly significant manner in those who improved. Three patients with corticosteroid-resistant disease progression were additionally treated with a combination of corticosteroids with POF. In all three patients the combination therapy resulted in an immediate complete decrease of disease activity, even after tapering prednisone to 7.5 mg daily or tapering off corticosteroids. These promising results suggest that POF may improve therapeutic regimens in pulmonary sarcoidosis either by sparing or replacing corticosteroids.

Adult↗
PubMed1997

[Pentoxifylline inhibits experimental bleomycin-induced fibrosing alveolitis].

Therapy of idiopathic pulmonary fibrosis (IPF) is directed at 1) inhibition of alveolitis and tissue damage, and 2) inhibition of matrix deposition. We and others have identified pentoxifylline (POF) as a promising drug in achieving these aims. For further clarification, we established a model of bleomycin-induced fibrosing alveolitis. Fisher 344 rats (n = 7 per group) were given bleomycin intratracheally once (0.7 U/100 g bw) and treated with POF (1.5 or 3 mg/kg bw per day i.p.), prednisolone (15 mg/kg bw i.m. per day), or sodium chloride solution (NaCL). The extent of inflammatory reactions was determined after 8 days by differentiation of cells of broncho-alveolar lavage (BAL) and by quantification of proliferating cells in lung interstitium subsequent to staining of the Ki-67 antigen. POF inhibited neutrophil alveolitis in BAL and reduced the amount of proliferating cells in the lungs significantly while prednisolone and NaCL did not. Both POF and prednisolone exerted a positive influence on postoperative weight loss as well as on lung weight increase subsequent to bleomycin instillation. The postoperative body weight loss and the lung weight increase after bleomycin instillation are most likely due to an inflammatory reaction subsequent to operation and bleomycin deposition. Tumor necrosis factor alpha (TNF-alpha) has been shown to be a key cytokine in bleomycin-induced fibrosing alveolitis as well as in IPF; it also exerts catabolizing effects. Since both POF and prednisolone are known to effectively inhibit proinflammatory cytokines and, among those, TNF-alpha, nonspecific antiinflammatory effects probably explain the benefits. Additionally, however, this study proved POF to be more effective in inhibition of BAL neutrophils and number of proliferating cells in lung interstitium. Further, it has been shown that POF, but not prednisolone, inhibits activation of neutrophil granulocytes and formation of reactive oxygen species. Thus we believe that the mechanism of action of xanthines might contribute to therapy of IPF. For further clarification, a prospective clinical study of POF in IPF therapy has been initiated.

Animals↗
PubMed1996

Obstructive sleep apnea syndrome and circadian rhythms of hormones and cytokines.

Several cytokines exhibit a high degree of temporal regulation as well as somnogenic potency (e.g., interleukin-1 [IL-1], tumor necrosis factor-alpha [TNF-alpha]). Seeking the underlying cause of obstructive sleep apnea syndrome (OSAS), we investigated whether circadian rhythms of cytokine release were altered in 10 patients with OSAS. Ten healthy volunteers served as the control population. Seven of the 10 OSAS patients were reexamined after 3 mo of therapy with nasal continuous positive airway pressure (nCPAP) mask ventilation. Circadian cytokine release (IL-1, IL-6, gamma-interferon [gamma-IFN], TNF-alpha) was investigated ex vivo by short-term culture of blood samples. The circadian rhythm of TNF-alpha release was significantly disturbed in OSAS patients: nocturnal physiologic peaks in this cytokine had almost disappeared and an additional daytime peak had developed. Circadian variations in IL-1, IL-6, and gamma-IFN, and in the immunoregulatory hormones melatonin and cortisol, did not differ from those in the controls. Because TNF-alpha is a known modulator of sleep, and nCPAP therapy did not normalize TNF rhythms, we assume that TNF-alpha could well play a pathophysiologic role in OSAS. Further studies should be directed at whether a physiopathologic and/or pathogenic link exists between TNF-alpha and OSAS.

Adult↗
PubMed1995

Common CFTR mutations are not likely to predispose to chronic bronchitis in northern Germany.

The frequency of six common mutations in the cystic fibrosis transmembrane conductance regulator gene was studied in 100 patients hospitalized with chronic bronchitis. Only one patient with chronic bronchitis and diffuse bronchiectasis was heterozygous for the common delta F508 mutation. R553X, G542X, G551D, N1303K and 621 + 1G-->T were not detected. This result is not significantly different from the frequency of cystic fibrosis carriers in Northern Europe. Predisposition of heterozygotes for chronic bronchitis is therefore unlikely.

Aged↗
PubMed1995

Frequency of common cystic fibrosis gene mutations in chronic bronchitis patients.

It has been suggested that the delta F508 deletion, the most common mutation in the cystic fibrosis (CF) gene, might be linked to chronic bronchial hypersecretion. We investigated whether such an association could be found in chronic bronchitis, since chronic bronchial hypersecretion is an important and specific element of chronic bronchitis. We screened 100 patients hospitalized for chronic bronchitis with six of the most frequently occurring CF gene mutations: delta F508, R553X, G542X, G551D, N1303K, and 621-1G-->T. Only one patient affected by chronic bronchitis and diffuse bronchiectasis was heterozygous for the deletion delta F508; no other mutations were found. This is not significantly different from the expected frequency of CF carriers in northern Europe, which is 1 in 25. Thus, no association between the most commonly occurring cystic fibrosis genes and chronic bronchitis is likely to exist and routine screening of patients without further signs of cystic fibrosis would seem to be of no benefit in northern Europe.

Aged↗
PubMed1992

A microtitre assay system for glucocorticoid receptors: decreased receptor concentration in myocardial infarction.

A major difficulty in determination of glucocorticoid receptor sites is the very complicated assay procedure. Therefore, we describe a microtitre assay system for glucocorticoid receptors which is a whole-cell competitive binding radioassay using [3H]-dexamethasone as radioligand. This modification of a previously described protocol simplifies and reduces laboratory work and allows assay reproducibility to be controlled more reliably. Thus enabled to perform the test on multiple blood samples in parallel, we investigated cardiac infarction patients over a 12-day period to test if glucocorticoid receptor binding is altered in this 'stressful' disease. On the first day of the disease, glucocorticoid receptor capacity was significantly decreased without alteration of the receptor-ligand affinity, whereas on days 4 and 12 the number of receptor sites was normal again. This result fits well into the general observation of stress-induced down-regulation of immune responses.

Aged↗
PubMed1990

Determination of serum concentrations of type III procollagen peptide in mechanically ventilated patients. Pronounced augmented concentrations in the adult respiratory distress syndrome.

Type III procollagen peptide (PCP) is a byproduct of type III collagen synthesis and a potential marker of collagen secretion. In chronic diffuse interstitial lung diseases, elevated PCP concentrations have been found in serum as well as in bronchoalveolar lavage fluid. It has been proposed that PCP is a marker of early, active stages of fibrosis. As severe fibrosis is a frequent complication in adult respiratory distress syndrome (ARDS), we investigated PCP in patients with ARDS and compared the results with those from patients requiring mechanical ventilation because of heart failure and after neurosurgical and surgical interventions, and those from spontaneously breathing patients, including healthy volunteers and patients with pneumonia, liver cirrhosis, and renal failure. PCP concentrations in patients with ARDS were extremely elevated compared with those in control subjects (p less than 0.001) and correlated positively with FiO2 (r = 0.71, p less than 0.01). These results support the pathophysiologic concept of early fibrogenesis in ARDS. As preventing pulmonary fibrosis in ARDS is essential in improving survival rate, we believe PCP can be a valuable diagnostic tool in ARDS.

Adult↗