Preparation and characterization of monoclonal antibodies to enteric adenovirus types 40 and 41

Summary We have prepared monoclonal antibodies to each of the enteric adenoviruses types 40 and 41. Three different hybridoma cell lines were selected which produced antibody found to react by radioimmunoprecipitation with adenovirus (Ad) hexon antigens. One was specific for Ad 40, another for Ad 41, and a third one reacted with both types. When tested in an enzyme immunoassay against all 41 known human Ad types, the type-specific monoclonal antibody against Ad 40 reacted homotypically, as did the monoclonal antibody against Ad 41. In addition, these monoclonal antibodies neutralized the homologous enteric Ad type. The monoclonal antibody which reacted with both enteric Ad types also showed lower levels of reactivity with the group C adenoviruses types 2, 5, and 6. The monoclonal antibodies produced will provide a definitive means for rapid identification of specific Ad types, and will be useful in defining the relationship of enteric adenoviruses to other types.     

Weight loss in patients with hematological neoplasias is associated with immune system stimulation

Summary Weight loss is the main symptom of so-called tumor cachexia. The pathogenetic mechanisms underlying cachexia are poorly understood; however, it appears that enhanced formation of cytokines such as interferon- and tumor necrosis factor- are involved. In 94 patients suffering from hematological neoplasias we compared body weight changes with serum neopterin, tryptophan, and kynurenine. Biochemical changes, the formation of neopterin, the degradation of tryptophan are closely related to interferon- activity. The majority of our patients had increased neopterin and decreased tryptophan concentrations. Weight loss was seen particularly in patients with higher neopterin and lower tryptophan values. An association between higher neopterin levels and greater weight loss was apparent at study entry and during the follow-up of patients. Our data support the concept that weight loss is closely linked to endogenous interferon- activity.Abbreviations NHL non-Hodgkin's lymphoma - HD Hodgkin's disease - MM multiple myeloma - MGUS monoclonal gammopathy of unknown significance - IFN- interferon- - TNF- tumor necrosis factor-     

Dominant-negative soluble PDGF-beta receptor inhibits hepatic stellate cell activation and attenuates liver fibrosis

Hepatic fibrogenesis is a consequence of hepatic stellate cells that become activated and transdifferentiate into a myofibroblastic phenotype with the ability to proliferate and synthesize large quantities of extracellular matrix components. In this process, platelet-derived growth factor (PDGF) is the most potent stimulus for hepatic stellate cell proliferation and migration, and is overexpressed during active hepatic fibrogenesis. This cytokine binds to the PDGF receptor type beta, activates Ras and sequentially propagates the stimulatory signal sequentially via phosphorylation of Raf-1, MEK and the extracellular-signal regulated kinases ERK1/ERK2. Hepatic injury is associated with both increased autocrine PDGF signaling and upregulation of PDGF receptor. In this study, we report that a dominant-negative soluble PDGF-beta receptor consisting of a chimeric IgG containing the extracellular portion of the PDGF receptor type beta blocks HSC activation and attenuates fibrogenesis induced by ligation of the common bile duct in rats. In culture-activated hepatic stellate cells, the soluble receptor blocks phosphorylation of endogenous PDGF receptor, phosphorylation of the ERK1/EKR2 signal and reduces proliferative activities of HSC. In vivo, both the delivery of the purified soluble PDGF antagonist and the administration of adenoviruses expressing the artificial transgene were able to reduce significantly the expression of collagen and alpha-smooth muscle actin. Our results demonstrate that PDGF plays a critical role in the progression and initiation of experimental liver fibrogenesis, and suggest that early anti-PDGF intervention should have a therapeutical impact on the treatment of liver fibrogenesis.     

CD14 and tolerance to lipopolysaccharide: biochemical and functional analysis.

To evaluate the role of the high-affinity monocyte receptor for lipopolysaccharide (LPS), CD14, in the process of tolerance to LPS, the human monocytic cell line Mono-Mac-6 was cultured in the absence or presence of different amounts of LPS. The kinetics of CD14 modulation in these cells showed an initial 4-day period characterized by increased cell-surface expression, rate of biosynthesis (peaking at 48 hr) and release of its soluble forms (sCD14) which correlated with the amount of LPS in the culture. At this time, tolerance to LPS was already established, as measured by tumour necrosis factor-alpha (TNF-alpha) induction, it was LPS dose dependent and persisted up to 15 days. LPS also reduced the cell proliferation rate in a dose-dependent manner. After 8 days and up to 15 days, the CD14 biosynthesis, cell-surface expression and release of sCD14 inversely correlated with the level of LPS in the culture. The 48-hr LPS-pretreated cells showed a slightly decreased CD14 affinity for LPS, a relative high number of CD14 molecules per cells, and desensitization also to a phorbol 12-myristate 13-acetate (PMA) challenge. An anti-CD14 monoclonal antibody (mAb) protected the cells from tolerization when added at the beginning of culture, as revealed by challenge with LPS and PMA. The data indicate that in this model tolerization to LPS (1) precedes CD14 down-modulation, (2) operates by alteration of the receptor affinity for LPS and by a mechanism which affects a protein kinase C (PKC)-dependent signalling pathway, and (3) that CD14 plays a critical role in the establishment of tolerance to LPS. In addition, analysis of the data suggests the existence of a PKC-independent signalling pathway for LPS tolerization and a CD14-independent mechanism for establishing tolerance.     

The importance of autopsy for quality assurance in medical care

For all persons who died in the city of Dresden and 7 surrounding counties from 1967 to 1978, documents relating to the clinical and pathologic diagnosis were examined and findings compared. The study covered nearly two thirds of all deaths which occurred in the district of Dresden during this time period. The autopsy rate overall was found to be 22.8%. In 57.3% the clinical diagnoses were found to have been correct, in 19.7% they corresponded in part, but in 23% there was no concordance whatsoever between the clinical and autopsy diagnoses. The influence of age, place of death and disease group on the agreement between clinical and underlying pathoanatomic diagnosis was also examined. The analysis highlighted the degree to which death statistics based on the death certificate are misleading. In up to 28.8% of cases there were formal errors in the underlying disease diagnosis listed by the certifying physician on the death certificate. The value of regular comparison between the diagnoses, and its usefulness for training and continuing medical education are emphasized. The results of the study underline the importance of making available more prospectors in the district of Dresden to meet the expanding tasks of the clinically active pathologist in autopsy and biopsy diagnostic efforts.     

ANF-Konzentrationen und Drücke im kleinen Kreislauf unter Belastung vor und nach Koronardilatation

Summary According to several reports of close correlations between pulmonary artery pressure and ANF plasma levels it would be convenient to replace invasive pressure monitoring by ANF determination.Mean pulmonary artery and right atrial pressures and pulmonary artery as well as peripheral venous ANF plasma concentrations were measured in 24 patients before and after coronary angioplasty (PTCA) continuously at rest and during exercise: At rest, both pressure and ANF-values remained unchanged before and after PTCA. At exercise, there was a decrease of mean pulmonary artery pressure (from 41.3±8.6 to 31.5±7.4 mmHg,p<0.001), mean right atrial pressure (from 11.9±3.0 to 9.0±2.3 mmHg,p< 0.001), pulmonary artery (282.5±191.0 to 207.3±157.2 pg/ml,p<0.05) and peripheral venous (112.7±48.0 to 97.1±53.2 pg/ml, n.s.) ANF concentration after PTCA. We found no correlation between PTCA-induced changes of right arterial pressures and ANF concentrations, while changes of pulmonary artery pressures were significantly correlated to changes of peripheral venous (r=0.79,p<0.001) as well as pulmonary artery (r=0.59,p<0.01) ANF concentrations at exercise. In 6 of the 24 patients, however there was an inverse relationship between changes of pulmonary artery pressures and ANF concentrations. — Our data demonstrate a significant correlation between changes of ANF plasma level and pulmonary artery pressure values at exercise after PTCA. In the individual case however invasive pressure monitoring cannot be replaced by determination of ANF plasma levels.

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Abkürzungsverzeichnis ANF Atrialer natriuretischer Faktor - PTCA Perkutane transluminale Koronarangioplastie - PPa mittlerer pulmonalarterieller Druck - PPc mittlerer pulmonalcapillärer Druck - PRA mittlerer rechtsatrialer Druck Herrn Prof. Dr. med F. Scheler zum 65. Geburtstag gewidmet     

Unwanted modification of the thyroid gland by drugs with special reference to nonsteroidal antirheumatic agents

In two retrospective clinical studies was investigated the influence of the modern non-steroidal antirheumatic drugs indometacin and diclofenac (Rewodina) on the thyroid gland and corresponding peripheral hormone parameters. Under longterm treatment with indometacin a moderate strumigenic effect could be observed, which could not clearly be proved under the diclofenac therapy. In all patients with rheumatoid arthritis, independent of the kind of pharmacotherapy, decreased T3-hormone levels were found in normal serum T4-values. The findings are discussed as "low-T3-syndrome" in rheumatoid arthritis, induced by the disease lasting for many years possibly in combination with the long-term therapy with antirheumatic drugs. In a second series of investigations in 75 out of 3,104 patients (2.4%) with a bland struma distinct references to a medicamentous evocation of the enlargement of the thyroid gland were found. Anticonvulsive drugs and the antidepressive drug lithium stood in the first place as inductors of such medicamentous struma. Of the non-steroidal antirheumatic drugs only some cases could be ascribed to phenylbutazone, whereas the more modern preparations indometacin and diclofenac in none of our patients could with certainty be made responsible for a development of struma.     

Prostaglandins: Antiproliferative effect of PGD 2 on cultured human glioma cells

Summary Five cultured human glioma cell lines were investigated for their reaction to prostaglandin (PG) D 2 and E 2. In all cases a suppressive effect on DNA synthesis as assessed by³H-thymidine incorporation was seen with all test substances as early as six hours after the addition of the compounds in doses of usually 10^–5 M. A dose response curve was generated in four cases and showed an estimated ED 50 of about 5 · 10^–6 M. The effect was most pronounced at 12 hours after which the cultures began to recover except those which had been incubated with PGD 2. In those cultures which had been exposed to PGD 2 virtually no thymidine incorporation was seen after 24 hours and as long as 72 hours.In another set of experiments, the effect of PGD 2, PGE 2, two synthetic PGD 2 analogues, with a chlorine substitution in position 9 (DACl) or with a fluoride substitution in position 9 (DAF) and a synthetic prostacyclin-analogue (Iloprost) was investigated after single and repeated addition of the compounds. A second administration after 12 hours of incubation did not result in a further decrease in³H-thymidine incorporation like that observed during that first incubation period. In general the cells recovered after 24 hours total incubation time except those which had received PGD 2 or repeated doses of PGE 2. Only in those cells which had been treated with PGD 2, an almost complete blockade of³H-thymidine incorporation was seen even after the single administration. Parallel evaluation of the cells by flow cytometry showed effects on cell cycle distribution at different times of the incubation. After 12 hours cells began to accumulate in G2/M at levels of approximately twice control, the effect being the least pronounced for PGD 2. For this compound we observed a threefold increase in cells in the S phase. After 24 hours the cell cycle distribution had normalized for all compounds except PGD 2 where the arrest of cells in G2/M persisted to be about 2–3-fold control level until the end of the experiment.Our data suggest, that also in cultured human glioma cells, prostaglandins are effective in suppressing cellular DNA synthesis.Although the effect of PGD 2 can be achieved to some extent by PGE 2 and the analogues which are more stable to dehydrogenases and the metabolic conversion into other biologically active homologues, PGD 2 appears to have a unique quality of action, becoming apparent 24 hours after administration.Abbreviations PG prostaglandin - DME Dulbecco's modified Eagle medium - STV trypsin in phosphate buffered saline EDTA (versene) - PBS phosphate buffered saline - ICP impulse cytophotometry - TCA trichloroacetic acid - DACl 9-chloro-15-cyclohexyl-11,15-dihydroxypentanor-5,13-prostadienoic acid- and DAF=9-Fluoro-15-cyclohexyl-11,15-dihydroxypentanor-5,13-prostadienoic acid Dedicated to Prof. Dr. Friedrich Loew on the occasion of his 65th birthday and the 25th anniversary of the Homburg Neurosurgical University Clinic, which has been founded and built up by him.