Biomedical subjects
Publications and source records attributed to W Barthlen.
Renal insufficiency developed in a newborn with huge bilateral renal cysts and posterior urethral valves. Definitive therapy consisted of laser coagulation of the valves and transient percutaneous drainage of the cysts.
Laser resection (LR) of posterior urethral valves during infancy as early as possible after diagnosis appears to represent a safe and reliable method. In contrast to other procedures, LR allows valve ablation with thin cystoscopes and carries little risk, even in premature and newborn infants. Its application in seven children in the course of 2 years principally confirmed its suitability for use: it could be applied in all cases without any problems and led to extensive resection of the valve tissue and removal of the obstruction in all patients. The encouraging clinical findings were confirmed by control cystoscopies and micturating cystourethrograms. Complications arising from the method were not observed.
Sepsis is a state of high turnover of bone-marrow cells. Nitric oxide (NO) is reported to be involved in cell proliferation and demise. Murine bone-marrow cells were incubated with lipopolysaccharide together with tumor necrosis factor alpha, interferon gamma and interleukin-1 beta for 48 h. The basal proliferation rate of the cells remained unchanged, but granulocyte-macrophage colony stimulating factor-induced proliferation was suppressed and the percentage of apoptotic cells significantly raised. Levels of nitrite in the culture supernatants were inversely correlated with the suppression of proliferation, but directly correlated with apoptosis. The NO synthesis inhibitor N-methyl-arginine inhibited the suppression of proliferation as well as the induction of apoptosis and NO synthesis. Our results indicate that NO is a negative feedback regulator of cell turnover in sepsis, which limits growth-factor-induced proliferation and induces apoptosis of bone marrow cells.
BACKGROUND/PURPOSE: Spontaneous tumor regression is a well-known characteristic in neuroblastomas. Because preliminary reports have shown that regression may be caused by apoptosis (a lethal cascade mediated by the CD95 (APO-1/Fas)-receptor), we analyzed the expression of CD95-receptors in 5 human neuroblastoma cell lines. Ceramides (known stimuli of apoptosis downstream from the CD95-receptor complex) also were used to test whether apoptosis would be induced in neuroblastoma cell cultures resistant to CD95-mediated programmed cell death. METHODS: The expression of the CD95-receptor was assessed by flow cytometry after incubation with either fluorisothiocyanate-conjugated (FITC) anti-CD95-antibody (UB2) or CD95-ligand for 16 hours. Apoptotic cell death was detected via microscopy, cell viability testing (MTT, 3-[4,5 dimehylthiazole-2-yl]-2,5 diphenyltetrazoliumbromide), and flow cytometric analysis after propidium iodide staining of the DNA. RESULTS: CD95-receptor expression was found on all neuroblastoma cell lines. Stimulation of the CD95-receptor of the malignant glioblastoma cell line LN229 (positive control) with either anti-CD95-antibody or CD95-ligand induced apoptosis. Apoptosis was not seen, however, in any of the neuroblastoma cell lines when the CD95-receptor was stimulated with anti-CD95-antibody or the CD95-ligand. Significant apoptosis was detected in all neuroblastoma cell lines after the addition of 25 micromol/L C2- and C6-ceramide. CONCLUSIONS: CD95-receptors are present on neuroblastoma cell lines, and these cells are resistant to apoptosis stimulated by anti-CD95-antibody or CD95-ligand. Apoptosis is induced, however, when these cells are treated with ceramide. A signal blockage downstream from the CD95-receptor complex and upstream of ceramide may account for this finding, and the "cellular FLICE inhibitory protein" (cFLIP) may be primarily responsible.
BACKGROUND: The effects of abdominal sepsis on the regulation of cell turnover in bone marrow and on the function of hematopoietic stem cells were investigated. METHODS: In a new mouse model of abdominal sepsis (colon ascendens stent peritonitis [CASP]) the proliferation, apoptosis, and colony-forming capacity of bone marrow cells were determined. RESULTS: Both experimental peritonitis and sham surgery increased proliferation of bone marrow cells significantly (P < .01). Incubation with granulocyte-macrophage colony-stimulating factor but not granulocyte colony-stimulating factor further augmented proliferation of bone marrow cells from septic mice. In contrast to cell proliferation, bone marrow cell apoptosis was significantly (P < .001) increased in response to CASP but not to sham surgery. CASP surgery and treatment of normal bone marrow cells with lipopolysaccharide, tumor necrosis factor-alpha, interleukin 1 beta, and interferon gamma increased the number of apoptotic cells to a similar extent. Stem cell assays revealed that during the late phase of peritonitis the colony formation by granulocytic-monocytic precursors was increased, whereas mature erythroid colony-forming cells were suppressed. Incubation of normal bone marrow cells with lipopolysaccharide and cytokines showed similar effects. CONCLUSIONS: These results reveal differential effects of experimental peritonitis on various hematopoietic lineages and suggest a potential role of inflammatory mediators for the dysregulation of bone marrow cell function during abdominal sepsis.
Phagocyte functions such as respiratory burst or phagocytic activity allow the determination of septic courses. Already in case of surgical stress a reduced constitutive generation of reactive oxygen metabolites could be shown, which is assumed to influence the outcome of following septic courses. The results of septic patients suggest that in spite of a functioning uptake of particles and germs (phagocytosis) a defect of intracellular killing (respiratory burst) exists.
The aim of this study was to compare and improve standard methods to determine nitrite (NO2-), nitrate (NO3-) and S-nitrosothiol (RSNO) levels in cell culture supernatants, sera, and urine. We modified the conventional Griess reaction by replacing sulfanilamide with dapsone (4,4'-diamino-diphenylsulfone) and compared the NO2- levels in our study samples with a commercially available NO2- assay kit. Our modification, along with ultrafiltration of the samples, resulted in an enhanced sensitivity to measure NO2- down to 0.2 microM. The detection limit was further improved to 0.02 microM when NO2- was identified by the fluorochrome 2,3-diaminonaphthalene (DAN). To measure the stable end product NO3- by the Griess reaction or the DAN method, this anion must be reduced to NO2-. We compared the capacity of bacterial nitrate reductase with the reducing metal cadmium to convert NO3- to NO2-. After reduction, NO2- levels were determined either by the DAN method or by our modified Griess reaction. We found that there was a high correlation (r2 = 0.998) in total NO2- concentrations in the study samples using both methods for reducing NO3- to NO2-. The simultaneous determination of NO2- and NO3- was achieved by using anion-exchange chromatography (HPLC; Polyspher IC AN-1 column). The detection limit of this assay for each anion is 0.5 microM, and it can be applied equally well to sera, urine, and culture media. We also adapted the DAN method to determine RSNO levels in our study samples. Using this approach, we were able to measure RSNO levels down to 0.15 microM. As result we discovered that RSNO levels were markedly increased in urine from septic patients and in supernatants from cytokine-stimulated human tumor cell lines. L-Citrulline, a coproduct of NO biosynthesis, was measured using a colorimetric assay with a sensitivity limit of 3.0 microM. Increased L-citrulline levels in media from cultured cells, but not in sera or urine, correlated with increased NO production. Although all methods studied were suitable for quantifying end products of NO in biological fluids and media, the use of bacterial reductase and the modified Griess reaction proved successful to provide the greatest sensitivity and linear range for routine measurements of NO2- and NO3-.
Altered host defense mechanisms after major surgery or trauma are considered important for the development of infectious complications and sepsis. In the present study, we demonstrate that major surgery results in a severe defect of T-lymphocyte proliferation and cytokine secretion in response to coligation of the antigen receptor complex and CD28. During the early postoperative course, reduced cytokine secretion was observed for interleukin-2 (IL-2), gamma interferon, and tumor necrosis factor alpha, which are associated with the Th1 phenotype of helper T lymphocytes, and for IL-4, the index cytokine of Th2 cells. During the late postoperative course, T-cell cytokine secretion increased to normal levels. Production of the anti-inflammatory cytokine IL-10 was altered, with different kinetics being selectively elevated during the late postoperative course. In contrast, the capacity of peripheral blood monocytes to present bacterial superantigens and to stimulate T-cell proliferation was normal or enhanced after surgery despite a significant loss of cell surface HLA-DR molecules. Thus, the level of major histocompatibility complex class II protein expression does not appear to predict the antigen-presenting capacity of monocytes obtained from surgical patients with uneventful postoperative recovery. Secretion of IL-1beta and IL-10 by endotoxin-stimulated peripheral blood monocytes was increased at different time points after surgery. Major surgery therefore results in a distinct pattern of immune defects with a predominant defect in the T-cell response to T-cell receptor- and CD28 coreceptor-mediated signals rather than an impaired monocyte antigen-presenting capacity. Suppression of T-cell effector functions during the early phase of the postoperative course may define a state of impaired defense against pathogens and increased susceptibility to infection and septic complications.
Nitric oxide (NO) has been implicated as the principal mediator of the catecholamine resistant vasodilation in septic shock. In this pilot study, we wanted to know if the serum values of nitrite/nitrate (NO2/NO3), the stable endproducts of NO biosynthesis, are elevated in patients with septic shock. Furthermore, we investigated whether there is a correlation between NO2/NO3 serum levels and tumor necrosis factor alpha or interleukin 6. NO2/NO3 serum values were significantly elevated in septic patients compared to controls (72.1 +/- 6.1 vs. 35.7 +/- 9.2 microM, p < .001). There was a significant positive correlation between serum values of NO2/NO3 and tumor necrosis factor alpha (rs = 0.59, p < .001). In contrast, no correlation between NO2/NO3 and interleukin 6 was found. With the exception of body core temperature, which showed a negative correlation with NO2/NO3 levels, no clinical variable turned out to be significantly related to NO biosynthesis. These data indicate a potential role for NO in the clinical course of abdominal sepsis, but points out that more specific data has to be evaluated by prospective clinical studies in order to understand the complex pathophysiologic role of this novel mediator.
Causes of septic multiple organ failure are endotoxin induced mechanisms, exotoxin induced mechanisms and sepsis associated immunosuppression. Pharmacological intervention is limited. Therapy is restricted to aggressive surgical treatment in terms of eradication of the source of infection combined with supportive intensive care medicine. The prevention of systemic infections is mandatory. Approaches to new therapeutical concepts are outlined.
A total of 1325 patients with bronchogenic carcinoma who were treated at the surgical clinic of the Technical University of Munich between 1981 and 1991 were enrolled in a prospective follow-up study. The 5-year actuarial survival rate of 605 patients with squamous cell carcinoma was 28.2%, of 288 patients with adenocarcinoma 38.0%, of 219 patients with small cell carcinoma 15.4%, of 74 patients with giant cell carcinoma 19.0%, and of 139 patients with other histologic findings 27.8%. In all, 680 patients (51.4%) underwent surgery. Diagnostic thoracotomy without resection was performed in 6.2% of cases. Lethality within 30 days was 1% for lobectomy, 7.3% for bilobectomy, and 7.7% for pneumonectomy including extended resections. The 5-year survival rates among the operated patients were 64.8% for T1N0M0 tumours, 49.4% for T2N0M0, 46.1% for T1N1M0, 43.4% for T2N1M0, 23.8% for T3 and 11.7% for T4. T1N0M0 adenocarcinoma was associated with a better prognosis than squamous cell carcinoma of the same early stage, with a 5-year survival rate of 82.2% vs 55.9%. The prognosis of patients with T3N2 was worse than that of patients with a T3-4 primary tumour but only N0-1 lymph node involvement (5-year survival rate 18.1% vs 31.7%). Stepwise logistic regression analysis identified tumour stage, therapy, and histologic result as the factors with the greatest impact on the prognosis. Adjuvant radiation after resection in patients with T2-3 adenocarcinoma or squamous cell carcinoma improved the prognosis by one tumour stage compared with patients who only underwent surgery. In conclusion, surgical therapy of bronchogenic carcinoma offers favourable survival rates with acceptable risk.(ABSTRACT TRUNCATED AT 250 WORDS)
In order to evaluate their prognostic relevance for survival 46 variables were submitted to univariate as well as multivariate analysis in a group of 184 patients with diffuse peritonitis. In the univariate analysis a significant correlation with the outcome was found for the following parameters: age greater than or equal to 70 years, preexisting hepatic or cardiac disease, no eradication of the primary source of infection at first laparotomy for peritonitis, cardiovascular instability, respiratory failure, hyperbilirubinemia, thrombocytopenia, elevated serum creatinine and diminished creatinine clearance at the beginning and proof of pseudomonas aeruginosa in the peritoneal exsudate and of candida albicans in the blood culture during the course of the peritonitis. In the multivariate analysis the surgical eradication of the primary source of infection at the first laparotomy for peritonitis, serum creatinine at the beginning of peritonitis, age greater than or equal to 70 years and a preexisting hepatic disease proved to be the independent variables with significant prognostic relevance for survival of the patients.
The therapeutical concept of programmed relaparotomy was performed in 184 patients with diffuse peritonitis from 4/1984 to 4/1991. Clinical results were prospectively documented and a total of 46 variables (e.g. risk factors, clinical parameters, laboratory tests, microbiological screenings, score systems) both univariate and multivariate were tested for prognostic significance. Total lethality rate was 26% (48/184 patients). If complete eradication of the source of infection was surgically achieved (150 patients/82%) lethality rate was only 9%. In contrast, lethality rate was 100% in patients with unsuccessful surgical focus eradication. Eradication of the source of infection during the first operation (104 patients/56%) resulted in a lethality rate of 6%, compared to 17% for patients who needed two or even more operations (46 patients/25%). Eradication of the source of infection during the first laparotomy ("focus eradication on time") was the most important prognostic parameters. Of further prognostic significance but with declining importance where serum-creatinine at the beginning of the treatment, patient's age (greater than less than 70 years) and preexistent hepatic disease.
Two cases of bronchial carcinoma with oesophageal involvement are presented. Both were treated by simultaneous pneumonectomy and oesophagectomy. The postoperative course of each patient was complicated by secondary infection of the pneumonectomy space. One patient expired from a recurrent intratracheal tumour on the 83rd postoperative day and the other remains tumour free 3 years after treatment. As few therapeutic alternatives exist for non small cell bronchial carcinoma, primary radical surgical treatment should be considered, even in advanced cases where the tumour invades the oesophagus.
Surgery for the treatment of Zenker's diverticulum was performed at our institution in a total of 43 patients over 6 1/2 years. Cervical myotomy with diverticulectomy was performed in 32 of the patients and myotomy alone in 11. Mortality totaled 0%, with a reversible lesion of the recurrent nerve occurring in 7%. In 60% of the cases investigated preoperatively (N = 40), motility disorders of the upper esophageal sphincter (UES) could be demonstrated using manometry as well as with cineradiography in 92% of the patients. Follow-up studies in 39 of the cases 25 months (mean) postprocedure indicated 82% of the patients to be symptom-free, with the remaining 18% demonstrating a marked improvement. Postoperative manometry as well as cineradiography carried out in 12 patients revealed the presence of UES motility dyscoordination in 8% and 25%, respectively. There were, however, no signs of recurrence of the diverticulum. The high number of patients in our study group demonstrating motility disorders of the UES emphasizes the need for cervical myotomy as part of the surgical therapy for Zenker's diverticulum.
More than 100 different mediators are discussed as being responsible for the progression of the septic shock syndrome. A new concept is described to establish the causal role of a single mediator by using a decision tree which excludes different non-causal associations (different kinds of bias and chance). By definition of several criteria and methodological standards, the published studies on mediator release/formation could be analysed and evaluated (meta-analysis). Furthermore, the classical concept of one cause--one disease (Koch-Dale) is extended to a concept of multiple determining factors. The role of a single mediator can be assessed quantitatively by notation of conditional probabilities in the presence of other causal factors. A mediator can be classified as a necessary, sufficient or contributory determinant in septic shock. Improved therapeutic concepts can be expected from this approach.
The expression of the Fas/APO-1/CD95 receptor on the neuroblastoma cell lines IMR-32, Kelly, SK-N-SH, LS and SiMa was investigated. The induction of apoptosis was attempted by incubation with Fas antibody IgM and IgG, Fas ligand and with ceramide. All neuroblastoma cell lines proved to be positive for Fas/APO-1/CD95 receptor expression by FACS. However, propidium iodide staining in FACS showed that neither incubation with the Fas antibody nor with the Fas ligand resulted in convincing apoptosis of the neuroblastoma cells. On the other hand, incubation with ceramide rapidly led to all signs of apoptosis morphologically and in the FACS. Therefore, other pathways than Fas/Apo-1/CD95 ligation must be of significance for the apoptosis of these neuroblastoma cell lines.