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P Zabel

Publications and source records attributed to P Zabel.

At least 91 records · Page 5Linked to original sources
PubMed1990

Circadian rhythm of interleukin-1 production of monocytes and the influence of endogenous and exogenous glucocorticoids in man.

We found a dose-dependent inhibition of spontaneous and LPS-induced IL-1 production of isolated human monocytes by methylprednisolone (MP) in vitro. Kinetic studies of spontaneous and LPS-induced IL-1 production of isolated monocytes of 10 normal individuals showed a synchronous circadian rhythm, with its maximum at 4:00 p.m. and its minimum at 4:00 a.m., which is most probably independent of the physiological circadian rhythm of cortisol levels because the IL-1 production was of the same value at the times of maximum and minimum cortisol levels. In contrast, in a patient with hypercortisolism and a preserved circadian rhythm of cortisol levels, we found the minimum of IL-1 production at 4:00 p.m., 8 hours after the maximum cortisol level was reached. Furthermore, in 7 patients with sarcoidosis both spontaneous and LPS-induced IL-1 production of isolated monocytes were significantly decreased 8 hours after the first injection of MP (1 mg/kg bw i.v.) compared to the values before MP administration. Our findings suggest a physiological circadian rhythm of spontaneous and LPS-induced IL-1 production of monocytes, independent of physiological cortisol levels, whereas unphysiological amounts of endogenous and exogenous glucocorticoids cause a substantial inhibition of IL-1 production with a latency time of 8 hours.

Adult↗
PubMed1990

Magnetic resonance imaging increases the blood-brain barrier permeability to 153-gadolinium diethylenetriaminepentaacetic acid in rats.

In a qualitative electron microscopy study we initially reported that exposure of rats to a standard clinical magnetic resonance imaging (MRI) procedure temporarily increased the blood-brain barrier (BBB) permeability to horseradish peroxidase. In this study, we quantitatively support our initial finding. Rats were injected intracardially with radio-labelled diethylenetriaminepentaacetic acid [( 153Gd]DTPA) in the middle of two sequential 23.2 min MRI exposures. Exposed rats (n = 21) showed significantly greater (29%, P = 0.006) retention of [153 Gd]DTPA than sham-exposed rats (n = 22) 1 h after the end of the last 23.2 min exposure. These findings suggest that magnetic fields may alter BBB permeability.

Animals↗
PubMed1990

Restriction fragment length polymorphism analysis of somatic hybrids between Lycopersicon esculentum and irradiated L. peruvianum: evidence for limited donor genome elimination and extensive chromosome rearrangements.

The genome composition of asymmetric somatic hybrids, obtained by fusion of leaf protoplasts from Lycopersicon esculentum and gamma-irradiated leaf protoplasts from L. peruvianum, was characterised by Southern blot analysis using 29 restriction fragment length polymorphism markers. Eight "low dose hybrids" and seven "high dose hybrids" (irradiation dose 50 Gray and 300 Gray, respectively) were analysed. By densitometric scanning of the autoradiographs, the number of alleles for each locus of the component species was established. In general, elimination of alleles from the irradiated L. peruvianum donor genome was limited and ranged from 17%-69%. Three L. peruvianum loci, located on chromosomes 2, 4 and 7, were present in all asymmetric hybrids, suggesting linkage to the regeneration capacity trait which was used in selecting them. The loss of donor genome was dose-dependent. Low dose hybrids contained more alleles, loci and complete chromosomes from L. peruvianum than high dose hybrids, whereas the high dose hybrids contained more incomplete chromosomes. In most hybrids some L. esculentum alleles were lost. The possible implications of these results for the use of asymmetric hybrids in plant breeding are discussed.

Alleles↗
PubMed1990

[Initial results of a controlled study of small cell and squamous epithelial bronchial cancer: polychemotherapy and interferons].

We investigated a combination of polychemotherapy with beta- and gamma-interferon in patients with small cell and squamous cell bronchial carcinoma. Immunological monitoring was designed to detect systemic and local immunomodulatory effects of interferon therapy. Small cell carcinoma was treated every three weeks with adriamycin, cyclophosphamide and vincristine, squamous cell carcinoma was treated every three weeks with mitomycin, vindesine and ifosfamide. In one group of patients polychemotherapy was combined with beta- and gamma-interferon. In the event of no change or tumour progression cisplatin and etoposide were administered. In the case of PR and CR the initial schedule was continued. Treatment was stopped on achieving CR after 6 cycles, or in the case of no response. To date, 40 patients have been evaluated. Results indicate a slight increase in the response rate in patients with small cell carcinoma, extensive disease, in the interferon group, and an unchanged response rate in patients with squamous cell carcinoma. Besides the common "flu-like" symptoms there was considerable myelosuppression in patients under additional interferon therapy. In the interferon group we found measurable gamma-interferon serum levels, an increase in the spontaneous production of IL 2 by peripheral lymphocytes, and an increase in the spontaneous production of IL 1 and an in the phagocytic capacity of monocytes. In contrast, alveolar macrophages as part of local immunity show a decrease in the spontaneous and LPS-induced production of IL-1.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

[Immunoglobulin G subclass deficiency in patients with asthma and chronic obstructive bronchitis].

In 99 patients with asthma or chronic obstructive bronchitis immunoglobulins and immunoglobulin-G subclasses were measured to characterize the frequency of humoral immune deficiencies. 26 patients had decreased serum levels in one or two IgG subclasses. So IgG-subclass deficiency is a common finding in patients with asthma and obstructive bronchitis. Treatment with corticosteroids seems to promote low IgG-subclass levels, but cannot fully explain alterations of IgG subclasses. Today IgG-subclass deficiencies are regarded as an important factor in the susceptibility to recurrent infections. We think, variation in IgG subclasses may have further effects on the noninfectious inflammatory processes of asthma and obstructive bronchitis.

Asthma↗
PubMed1990

[Therapy with immunoglobulins].

Adequate IgG-replacement therapy as treatment of choice for patients with humoral immunodeficiencies has revolutionized the outcome of these disorders. The action of intravenous immunoglobulins (IVIG) in autoimmune diseases, especially in idiopathic thrombocytic purpura seems to be due to Fc-receptor blockade and immunomodifying qualities. Thus far, treatment for patients with subclass deficiencies is restricted to persons with recurrent infections.

Autoimmune Diseases↗
PubMed1990

[Detection of pulmonary hypertension in patients with local circumscribed scleroderma].

In three patients with local circumscribed sclerodermia (duration of the disorder 6 months to 3 years), a latent or manifest pulmonary hypertension of the precapillary type in the presence of otherwise unremarkable lung function, radiological and ergometric data, was observed. The pulmonary involvement in this disease would appear to have a relatively early onset.

Biopsy↗
PubMed1988

[Intragastric provocation and antigen-induced in vitro histamine liberation by the food additive E 102].

Adverse reactions to tartrazine have been known since 1958. The mechanism of this reaction, a not IgE-mediated, anaphylactoid reaction, is not fully understood. The demonstration of this adverse reaction by provocative challenge feeding may be problematic by a score of subjective symptoms because of the placebo effect. This report deals with the intragastral provocation under endoscopic control with tartrazine and tartrazine-induced histamine release in vitro from gastric mucosa and from blood. Two patients with anamnestically suspected adverse reactions to tartrazine were studied. Correspondence of in vivo and in vitro testing with tartrazine could be demonstrated.

Azo Compounds↗
PubMed1988

Comparison of the biodistribution of gadolinium-153 DTPA and technetium-99m DTPA in rats.

Twenty-three mature Sprague-Dawley male and female rats were simultaneously injected with trace quantities of [153Gd]DTPA and [99mTc]DTPA and 0.5 mmol/kg of nonradioactive gadolinium DTPA. Rats were killed at 1 min, 5 min, 10 min, 15 min, and 30 min after the intracardiac bolus injection. The heart, lungs, liver, brain, kidney, and blood were excised and counted in a well-counter to determine the amount of the injected material in each organ and blood. In order for the percent of total injected activity to be determined, a technique was developed which allowed discrimination of the 140 keV gamma-ray of 99mTc from sum peaks of 153Gd when the latter is counted in a well-counter with 4 pi geometry. Although the distribution of the two DTPA compounds was qualitatively similar, statistical analysis indicated that the amount of 99mTc deposited in the lungs was higher than 153Gd (p = 0.03), the amount of 99mTc deposited in the kidneys was lower than 153Gd (p = 0.0004) and the amount of 99mTc in the blood was higher than 153Gd (p = 0.0022). This may be due to the greater binding of [99mTc]DTPA or its minor impurities to plasma proteins.

Animals↗
PubMed1985

[Recurrences of extracapillary glomerulonephritis in 2 kidney grafts in the same patient].

An IgA-IgM positive, rapidly progressive glomerulonephritis developed in two successive transplants in a 28-year-old patient. Both transplants failed. In the prevention and treatment of rejection corticoids and cortisone, antithymocyte globulin and cyclosporin A were administered but could not prevent the development of this form of glomerulonephritis. It remains to be shown whether it presents a contraindication to transplantation.

Adult↗
PubMed1984

Cowpea mosaic virus VPg: sequencing of radiochemically modified protein allows mapping of the gene on B RNA.

A partial amino acid sequence of cowpea mosaic virus (CPMV) VPg radiochemically modified by chloramine-T and Bolton-Hunter reagent has been determined. VPg covalently bound to viral RNA chains (VPg-RNA) was iodinated with chloramine-T and Bolton-Hunter reagent to label tyrosine and lysine residues, respectively. [I]VPg-RNA was digested with nuclease P1 and the resulting [I]VPg-pU was purified by SDS-polyacrylamide gel electrophoresis and subjected to automated Edman degradation. Control experiments with chemically synthesized poliovirus VPg showed the feasibility of radiochemical microsequence analysis of protein that had been radiochemically modified by chloramine-T and Bolton-Hunter reagent. Analysis of CPMV [I]VPg-pU revealed the presence of tyrosine residues at position 12 and 14, and of lysine residues at position 3 and 20, respectively. In combination with Edman degradation of unlabeled CPMV VPg, which showed serine and arginine residues to be present at position 1 and 2, respectively, the data obtained allow the precise positioning of VPg within the 200 000 dalton (200 K) polyprotein encoded by CPMV B RNA and the prediction of its entire amino acid sequence. VPg is located at the COOH terminus of its 60 K, membrane-bound,precursor and proximal to the amino terminus of the protease-polymerase domain of the polyprotein. A processing scheme for the 200 K polyprotein is discussed in which Gln-Ser amino acid pairs act as the major signal for proteolytic cleavage.

Journal Article↗
PubMed1984

Purification of cowpea mosaic virus RNA replication complex: Identification of a virus-encoded 110,000-dalton polypeptide responsible for RNA chain elongation.

An endogenous cowpea mosaic virus (CPMV) RNA-protein complex (CPMV replication complex) capable of elongating in vitro preexisting nascent chains to full-length viral RNAs has been solubilized from the membrane fraction of CPMV-infected cowpea leaves using Triton X-100 and purified by Sepharose 2B chromatography and glycerol gradient centrifugation in the presence of Triton X-100. Analysis of the polypeptide composition of the complex by NaDod-SO(4)/PAGE and silver staining revealed major polypeptides with molecular masses of 110, 68, and 57 kilodaltons (kDa), among which the 110-kDa polypeptide was consistently found to cosediment precisely with the RNA polymerase activity. Using antisera to specific viral proteins, we found the 110-kDa polypeptide to be the only known viral polypeptide associated with the RNA replication complex, the 68- and 57-kDa polypeptides being most probably host-specific. The host-encoded 130-kDa monomeric RNA-dependent RNA polymerase, which is known to be stimulated in CPMV-infected cowpea leaves, did not copurify with the virus-specific RNA polymerase complex. Our results dispute the hypothesis that plant viral RNA replication may be mediated by the RNA-dependent RNA polymerase of uninfected plants. We tentatively conclude that the 110-kDa polypeptide encoded by the bottom component RNA of CPMV constitutes the core of the CPMV RNA replication complex.

Journal Article↗