Coronavirus induced demyelinating encephalomyelitis in rats: immunopathological aspects of viral persistency.
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Biomedical subjects
Publications and source records attributed to J Winter.
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Benign oesophageal stenosis can be treated by different methods. Besides surgical procedures and established conservative treatment (e.g. dilatation), more invasive endoscopic techniques such as cryosurgery and laser therapy have recently been developed. Intubation, which has been used to treat malignant strictures, can also be used in benign oesophageal strictures. Between 1977 and 1989 a total of 43 tubes were implanted in 26 patients (mean age 62.3 years). The mean duration of intubation was 149 days. We report our experience in patients intubated for (1) acid burns, (2) actinic strictures, (3) peptic strictures, (4) postoperative stenosis, (5) postoperative complications and (6) tracheo-oesophageal fistulae. We also discuss the complications (dislocation, disintegration, bleeding, perforation, operative removal) and long-term results. Because of the prolonged survival of patients with benign oesophageal stenosis, follow-up and late complications are of particular importance in this report. Despite drawbacks, intubation is an option in the management of patients with benign oesophageal stenosis.
Heyde's syndrome is characterized by gastrointestinal bleeding due to angiodysplasias of the gut associated with calcific aortic stenosis. This association does not seem to be a patho-etiological entity but an occasional coincidence in the elderly. Aortic valve replacement (preferably with a bioprothesis) has been postulated to be the treatment of choice for the cure of the bleeding. Two cases of this syndrome are reported on. In one of the cases implantation of a bioprosthesis was accompanied by almost immediate cessation of bleeding, but with reoccurrence after one year necessitating local therapy. In the other case postoperative bleeding following aortic and mitral valve replacement with mechanical prostheses and tricuspid annuloplasty was the reason for coloscopic examination, which showed areas of angiodysplasia in the ascending colon. However, apart from a pause in anticoagulation medication no additional therapy was required since the hemorrhage ceased.
Desulfovibrio vulgaris Marburg, "Desulfovibrio simplex" XVI, and Desulfovibrio sp. strain MP47 used benzaldehydes such as vanillin, 3,4,5-trimethoxybenzaldehyde, protocatechualdehyde, syringaldehyde, p-anisaldehyde, p-hydroxybenzaldehyde, and 2-methoxybenzaldehyde as electron donors for sulfate reduction and carbon dioxide and/or components of yeast extract as carbon sources for cell synthesis. The aldehydes were oxidized to their corresponding benzoic acids. The three sulfate reducers oxidized up to 7 mM vanillin and up to 4 mM p-anisaldehyde. Higher concentrations of vanillin or p-anisaldehyde were toxic. In addition, pyridoxal hydrochloride and o-vanillin served as electron donors for sulfate reduction. Salicylaldehyde, pyridine-2-aldehyde, pyridine-4-aldehyde, and 4-hydroxy-3-methoxybenzylalcohol were not oxidized. No molecular hydrogen was detected in the gas phase. The oxidized aldehydes were not further degraded.
Enhanced synthesis and deposition of extracellular matrix components, including collagen, contribute significantly to arteriosclerotic changes in the arterial vessel wall. We localized cells actively synthesizing collagen by hybridizing 35S-labeled RNA probes complementary to type I and III collagen mRNA with cytoplasmic mRNA in frozen sections of surgically removed aortic coarctations. These were chosen as a model for comparing mRNA levels in areas of high blood pressure-induced wall thickening and in unaffected post-stenotic areas. In situ hybridization revealed increased expression of type I and III collagen mRNA in intimal cells and in cells adjacent to the medial-adventitial border in the pre-stenotic part of the coarctation. In contrast, cells of the post-stenotic area showed only a very low signal. No immunohistologically detectable macrophages were seen in the pre-stenotic subendothelial areas where mRNA levels were enhanced. Higher collagen mRNA levels therefore occur in particular regions of high blood pressure-induced arterial wall thickening in the absence of macrophages. The results suggest that in situ hybridization is suitable for detection of locally occurring transcriptional activation of cells for collagens in the vessel wall.
Quartered rat adrenal glands transformed labelled 21-deoxyaldosterone into aldosterone in vitro. 21-deoxyaldosterone was released from the quartered rat adrenals in vitro in amounts 10 times lower than those of aldosterone and 18-hydroxycorticosterone. The production of all three steroids was qualitatively dependent on the same regulatory elements (electrolytes, ACTH, exogenous precursors, zonal specificity). However, quantitative differences could be observed. The results support a role for 21-deoxyaldosterone as a facultative precursor of aldosterone and indicate that the regulation of its production shows similarities to that of aldosterone.
The hypothesis that dietary calcium alters the incidence of colorectal neoplasms was examined in an established model of carcinogenesis. Male Fischer 344 rats (28 days old) were quarantined for 2 weeks. All animals were fed the basal diet (AIN-76) supplemented with cholic acid (0.2%) and/or calcium (1.6%, corresponding to a 3-fold increase above that of the basal diet). N-Methyl-N-nitrosourea (MNU) (2 mg/dose) or saline (control) was given intrarectally to all animals on days 1 and 4 of the experiment. Groups 1-8 were fed the experimental diets concurrently with the first dose of MNU, while groups 9 and 10 were fed the diets 2 weeks prior to MNU (or saline). All animals were sacrificed after 28 weeks. No tumors were observed in the groups given saline (groups 1, 3, 5, 7, and 9). In groups receiving MNU, the addition of cholic acid to the diet (group 4) caused a significant increase in tumors (80% versus 55%), tumors/animal ratio (2.24 versus 0.75), and tumors/tumor-bearing animal ratio (2.80 versus 1.36), group 4 versus group 2, respectively. Increased dietary calcium did not inhibit tumor formation; 68% of animals in groups 6 and 10 had tumors. The combination of dietary cholic acid and calcium (group 8) gave a tumor incidence similar to cholic acid (group 4) alone (72% versus 80%, 2.00 versus 2.24 tumors/animal; 2.77 versus 2.80 tumors/tumor-bearing animal). Most tumors were adenomatous polyps but carcinomas in situ and invasive carcinomas were also present; dietary calcium reduced the number of invasive carcinomas (group 6 versus group 2, P less than 0.04).
Two new methanogenic bacteria, Methanocorpusculum sinense spec. nov. strain DSM 4274 from a pilot plant for treatment of distillery wastewater in Chengdu (Province Sichuan, China), and Methanocorpusculum bavaricum spec. nov. strain DSM 4179, from a wastewater pond of the sugar factory in Regensburg (Bavaria, FRG) are described. Methanocorpusculum strains are weakly motile and form irregularly coccoid cells, about 1 micron in diameter. The cell envelope consists of a cytoplasmic membrane and a S-layer, composed of hexagonally arranged glycoprotein subunits with molecular weights of 90,000 (Methanocorpusculum parvum), 92,000 (M. sinense), and 94,000 (M. bavaricum). The center-to-center spacings are 14.3 nm, 15.8 nm and 16.0 nm, respectively. Optimal growth of strains is obtained in the mesophilic temperature range and at a pH around 7. Methane is produced from H2/CO2, formate, 2-propanol/CO2 and 2-butanol/CO2 by M. parvum and M. bavaricum, whereas M. sinense can only utilize H2/CO2 and formate. Growth of M. sinense and M. bavaricum is dependent on the presence of clarified rumen fluid. The G + C content of the DNA of the three strains is ranging from 47.7-53.6 mol% as determined by different methods. A similar, but distinct polar lipid pattern indicates a close relationship between the three Methanocorpusculum species. The polyamine patterns of M. parvum, M. sinense and M. bavaricum are similar, but distinct from those of other methanogens and are characterized by a high concentration of the otherwise rare 1,3-diaminopropane. Quantitative comparison of the antigenic fingerprint of members of Methanocorpusculum revealed no antigenic relationship with any one of the reference methanogens tested. On the basis of the distant phylogenetic position of M. parvum and the data presented in this paper a new family, the Methanocorpusculaceae fam. nov., is defined.
In contrast to developing sensory neurons, the survival of adult rat dorsal root ganglion neurons in pure neuronal culture is not dependent on specific neurotrophic factors such as nerve growth factor or brain-derived neurotrophic factor [Lindsay R. M. (1988) J. Neurosci. 8, 2394-2405]. In the present study we have examined possible modulatory effects of nerve growth factor on the neuropeptide content of sub-populations of adult rat dorsal root ganglion neurons in vitro. During the first 1-2 days in culture the neuropeptides substance P and calcitonin gene-related peptide could be detected by immunofluorescence staining in cultures grown in the presence or absence of nerve growth factor, but at longer times in nerve growth factor-deprived cultures there was loss of immunoreactive staining for both peptides. In the presence of nerve growth factor, however, the percentage of substance P- and calcitonin gene-related peptide-immunoreactive neurons remained relatively constant, for at least 14 days, at levels that were similar to the percentage of such peptide-containing neurons found in sections of adult rat dorsal root ganglia. Quantitation by radioimmunoassay of the levels of substance P and calcitonin gene-related peptide in cultures grown in the presence or absence of nerve growth factor agreed with the qualitative observations obtained by immunofluorescence: 10-15-fold higher levels of substance P and calcitonin gene-related peptide were found in cultures grown with nerve growth factor for 18 days, as compared to nerve growth factor-deprived cultures. In nerve growth factor-treated cultures increased levels of substance P and calcitonin gene-related peptide were observed within 3-6 days in vitro, and further steady increases in the levels of both peptides were found up to 18 days. A low basal level of both peptides could always be detected, even in the presence of an excess of antibodies to nerve growth factor. Up-regulation of the synthesis of substance P and calcitonin gene-related peptide did not depend on nerve growth factor being present at the initiation of the cultures, as elevated levels of both peptides could be induced in cultures even after up to 10 days' prior deprivation of nerve growth factor. Removal of nerve growth factor from the cultures resulted in reduced levels of peptide within 3 days.(ABSTRACT TRUNCATED AT 400 WORDS)
Temporary myocardial pacing leads are routinely used for diagnosis and treatment of postoperative arrhythmias following open-heart surgery. The intention of this study is to compare five different electrodes for reliability during the postoperative period. A standardised technique of implantation was used to place 147 ventricular and 81 atrial wire electrodes in 149 patients. During operation and then daily over the next ten days, the stimulation threshold, P- and R-wave sensing, and impedance were measured with a pacing system analyser to evaluate the reliability of the pacing and sensing function. Five measurements were taken at each time; the mean values were statistically analysed. The number of failures in pacing and sensing and the course of the tested parameters during the postoperative period were compared. As a result, bipolar pacing leads (Osypka TME 64a/66a) proved to be more reliable than unipolar wires (Ethicon HD 12S, Osypka TME 60/60a), particularly in atrial sensing. Also the Medtronic 6400/6500 showed good reliability for the ventricle, so that they can be recommended for VVI-mode pacing. In conclusion, for reliable function during the postoperative course up to 10 days a specially developed bipolar temporary pacemaker electrode can be recommended for both atrial and ventricular or sequential pacing.
Aberrant adrenal cortical tissue is often found in close contact to the urogenital system. In a prospective study covering 150 operations for inguinal hernia, and 110 operations for undescended testes, we looked for aberrant adrenal cortical tissue. In 5.2% of the inguinal hernias and 10.9% of the undescended testes, aberrant adrenal cortical tissue was found. The frequency was higher than reported in the literature. The aberrant adrenal cortical tissue is of clinical importance only in the very rare cases of development of malignant tumours in this tissue.
We have detected hsc70 gene expression (heat shock protein hsp70 cognate) during vegetative growth and reproductive development in tomato (Lycopersicon esculentum). Using RNA from a tomato hsc70 cDNA as a probe in in situ hybridizations, we have determined expression patterns of hsc70 in nonstressed tomato roots, stems, leaves, flowers, and developing fruits. We have localized high levels of hsc70 transcript to the vascular system of the ovary, dividing cells of the lateral root tips, and the inner integument of developing seeds. We also see expression in the transmitting tissue, in immature anthers, and in embryos. We cannot detect expression in mature pollen, xylem, or ovules. These data indicate that the expression of at least some tomato hsp70 family members is developmentally regulated.
Four hitherto undescribed Clostridium strains capable of cleaving the C ring of quercetin, kaempferol, and naringenin at C-3-C-4 were isolated from the fecal flora of humans. None of the strains cleaved catechin. C-ring fission occurred when the substrate was either in solution or in suspension. Mixed cultures of flavonoid-hydrolyzing bacteria, flavonoid-cleaving bacteria, and Escherichia coli, which was used to provide the anaerobic environment, rapidly metabolized rutin to 3,4-dihydroxyphenylacetic acid, indicating that the intestinal half-life of the biologically active aglycone is short. The cleaving strains shared many phenotypic characteristics, including their inability to ferment sugars, but they differed sufficiently to indicate that they represent different species.
Neuronal membranes from rat dorsal root ganglia provide a mitogenic signal to cultured Schwann cells and it has been suggested this is an important factor in regulating Schwann cell numbers during development. In this study, the influence of enteric neurons on the DNA synthesis of both Schwann cells and enteric glia has been investigated as well as the effect of axonal membrane fractions (axolemma) on enteric glia. The proliferation rate of rat Schwann cells and enteric glia was assessed in culture using [3H]thymidine uptake and autoradiography in combination with immunolabelling to identify cell types. When purified rat Schwann cells were co-cultured with guinea pig enteric neurons, their DNA synthesis rate was reduced compared with control cultures of pure Schwann cells or Schwann cells not close to neurites or neuronal cell bodies. Nevertheless, in accordance with previous findings that sensory neurons stimulate Schwann cell division, these Schwann cells increased their DNA synthesis rate when in contact with neurites from purified guinea pig or adult rat dorsal root ganglion neurons and on exposure to bovine axolemmal fractions. The enteric neurons also suppressed the DNA synthesis of enteric glia in co-cultures of purified enteric neurons and enteric glia, while bovine axolemma stimulated their DNA synthesis. These results indicate that a mitotic inhibitory signal is associated with enteric neurons and can exert its effect on both Schwann cells and enteric glia, and that enteric glia, like Schwann cells, are stimulated to divide by axolemmal fractions. It thus seems possible that during development glial cell numbers in the peripheral nervous system may be controlled by both positive and negative regulators of cell growth.
Elevated calcitonin (CT) levels after primary operation of the medullary thyroid carcinoma (MTC) are a reliable marker for persistence or recurrence of MTC, which first metastasizes in the neck or mediastinal region. The reliability of different localisation methods before reoperation in 28 patients with elevated CT levels was tested by comparing their diagnostic results with the actual finding at reoperation. The diagnostic procedures comprised ultrasonography of the neck, CAT-scan of the neck and mediastinum, selective venous catheterization with CT determinations, and fine needle biopsy. Due to the results of these tests 28 patients were reoperated 48 times. Histological evidence confirmed the presence of suspected tumor that had been diagnosed by: palpation 52%, ultrasonography 78%, CAT-scan 70%, selective venous catheterization 75%, fine needle biopsy 81%. Despite the fact that only 2 out of the 28 patients had normal CT levels postoperatively, the 5 year survival rate in reoperated patients (86%) improved compared to patients without reintervention (69%). For precise preoperative staging ultrasonography seems to be the most predictable and reliable method. The prognosis of MTC patients with elevated CT-levels in the follow-up period could be improved by frequent reoperations.
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Using tetrahydroaldosterone antibody a radioimmunoassay was developed to measure substance Kelly-M1 (K-M1) in human urine. The normal values were lower than observed by Kelly et al. who discovered the catabolite after giving large doses of exogenous aldosterone. While in essential hypertension the excretion of K-M1 was predominantly within the normal range, elevated values were found in most cases of 21-hydroxylase deficiency, both the simple virilizing and salt losing form, primary aldosteronism, renal hypertension and cystinosis. Our findings suggest that K-M1 may be formed from 21-deoxyaldosterone and/or by microbial intervention from aldosterone or its metabolites.
An overlap between subpopulations of nerve growth factor (NGF)-responsive and capsaicin-sensitive dorsal root ganglion (DRG) sensory neurons has been suggested from a number of in vivo studies. To examine this apparent link in more detail, we compared the effects of capsaicin on adult rat DRG neurons cultured in the presence or absence of NGF. Capsaicin sensitivity was assessed histochemically by a cobalt staining method, by measuring capsaicin-induced 45Ca2+ uptake, and by electrophysiological recording of capsaicin-evoked membrane currents. When cultured with NGF, approximately 50% of these adult DRG neurons were capsaicin-sensitive, whereas adult sympathetic neurons or ganglionic nonneuronal cells were insensitive. DRG cultures grown in the absence of NGF, however, were essentially unresponsive to capsaicin. Capsaicin sensitivity could be regained fully within 4-6 days of replacement of NGF. These results indicate that, at least in vitro, NGF can modify the capsaicin sensitivity of adult DRG neurons.