Search PubMed⌕ Search

Biomedical subjects

J Roth

Publications and source records attributed to J Roth.

At least 307 records · Page 17Linked to original sources
PubMed1993

Role of hypothalamic interleukin-6 and tumor necrosis factor-alpha in LPS fever in rat.

The purpose of this study was to determine, using push-pull perfusion, the levels of interleukin (IL)-1-like, IL-6-like, and tumor necrosis factor-alpha (TNF)-like activity in the anterior hypothalamus during lipopolysaccharide (LPS)-induced fever in rats. Additionally, slow anterior hypothalamic infusions of human recombinant IL-6 (hrIL-6) or TNF (hrTNF) for several hours were performed to determine possible febrile effects of these two cytokines. Artificial cerebrospinal fluid (aCSF) was infused as a control. Samples of cerebrospinal fluid were collected 60 min before and 60, 180, 300, and 420 min after the intraperitoneal injection of LPS. A control group was injected intraperitoneally with saline. The core temperature (measured by biotelemetry) of LPS-injected rats was significantly higher (P < 0.05) than the temperature of the rats injected with saline at 180, 300, and 420 min after the injection. The average postinjection IL-6 levels were significantly higher (P < 0.05) in the LPS-injected group. TNF was significantly higher (P < 0.05) than the baseline only at 180 min. There were no changes in levels of IL-1-like activity. Infusion of hrIL-6 at a level similar to the peak IL-6 level measured during LPS-induced fever resulted in a slowly developing and long-lasting increase in core temperature. Infusion of hrTNF at a level corresponding to the peak TNF level measured during LPS-induced fever did not induce a significant increase in core temperature. These results support the hypothesis that elevated hypothalamic concentrations of IL-6 are involved in the induction of fever elicited by peripheral (intraperitoneal) injection of LPS.

Animals↗
PubMed1993

Kinetics of systemic and intrahypothalamic IL-6 and tumor necrosis factor during endotoxin fever in guinea pigs.

The time course of activity of interleukin-6 (IL-6) and tumor necrosis factor (TNF) was measured in blood plasma and hypothalamic push-pull perfusates during the febrile response to intramuscular injection of bacterial endotoxin (Escherichia coli, 20 micrograms/kg) in 24 guinea pigs. Injection of endotoxin caused a dramatic increase of IL-6 activity in plasma. The logarithmic values of plasma IL-6 activities showed a linear correlation to the febrile change in body temperature (r = 0.898) during the whole time course of fever. IL-6 activity in hypothalamic perfusates increased 12-fold in the first hour after pyrogen application and declined slowly despite the further increase in body temperature. Hypothalamic IL-6 activity did not correlate with the febrile increase in body temperature (r = -0.048). TNF activity in plasma, not detectable before pyrogen application, had its peak in the first hour after endotoxin injection and rapidly declined to 15-20% of the peak activity within the next 2 h and to an undetectable value 5 h after injection. In the hypothalamus TNF was not detectable before endotoxin injection, but it could be monitored in most animals after pyrogen application without a clear correlation to the fever response. These results taken together indicate that endotoxin fever represents a physiological situation in which production and release of cytokines in the peripheral immune system and in the hypothalamus are regulated and stimulated in independent patterns.

Animals↗
PubMed1993

Neurobiological concepts of fever generation and suppression.

Fever is induced by interactions of bacterial pyrogens with cells from the immune system, which subsequently release a cascade of cytokines. After intramuscular injection of lipopolysaccharide (LPS) from E. coli, increased amounts of tumor necrosis factor (TNF) and interleukin-6 (IL-6) can be measured in blood plasma and in perfusates of the anterior hypothalamus, where body temperature is regulated. These substances are therefore candidates to be involved in the modification of thermoregulatory structures leading to the febrile rise in body temperature. This increase of body temperature is limited and sometimes even prevented by the actions of endogenous antipyretic neuropeptides like arginine vasopressin (AVP), adrenocorticotropin (ACTH) and melanocyte-stimulating hormones (MSHs) liberated within the brain or systemically during fever. For AVP, most experimental evidence confirms antipyretic pathways from the hypothalamic paraventricular nucleus to the septal area of the limbic system, which are activated during fever and by several stressful stimuli. Fever and endogenous antipyresis are interconnected and result from interactions between the immune system and the central nervous system.

Animals↗
PubMed1993

Ontogeny, circadian rhythm pattern, and hormonal modulation of 5 alpha-dihydrotestosterone receptors in the rat pineal.

Some physiological parameters of pineal 5 alpha-dihydrotestosterone receptor in the rat such as ontogeny, circadian rhythm pattern, and its modulation by various neuropeptides and neurotransmitters which have profound influences on the pineal hormone melatonin were examined. Pineal 5 alpha-dihydrotestosterone receptors measured at different ages of the animal revealed that on day 10 both cytosolic receptor (CR) and nuclear receptor (NR) levels were high. With growth and development both groups of receptors declined and during puberty started again to rise. During adulthood both receptors were high; however, NR rose further with full maturation. Both groups of receptors showed circadian rhythmicity. While the CR was significantly higher at 6.00 h than at any time point through 24 h, the NR peaked at 18.00 h when the difference between both groups was maximum. Castration caused significant increment of NR. Treatment of castrated animals with a low dose of testosterone propionate (0.25 mg) significantly stimulated both receptor groups, while treatment with a high dose (2.5 mg) failed to do so. Treatment with various substances such as antiandrogen, opioids, neuropeptides, and neurotransmitters significantly modulated the pineal androgen receptor population: cyproterone acetate and monosodium glutamate suppressed CR; growth hormone releasing hormone increased NR; growth hormone release inhibiting hormone had no significant effects on either group of receptors; exogenous melatonin and norepinephrine increased NR; beta-endorphin increased only NR, but methionine enkephalin stimulated both, and epithalamine had no significant effects on either group of receptors, but thymosin alpha 1 increased NR.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

The contact allergens nickel chloride and cobalt chloride directly induce expression of endothelial adhesion molecules.

Activation of vascular endothelium is a key event in the initial phase of an inflammatory reaction e.g. to contact allergens. In the present study the effect of two common contact sensitizers, NiCl2 and CoCl2, on endothelial expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and endothelial leukocyte adhesion molecule-1 (ELAM-1, E-selectin) was studied. NiCl2 and CoCl2 were found to upregulate these adhesion molecules on human umbilical vein endothelial cells (HUVEC) in a dose- and time-dependent manner as could be demonstrated by flow cytometry and enzyme-linked immunosorbent assay. During organ culture of foreskin samples treatment with NiCl2 led to upregulation of ELAM-1 and ICAM-1 but not VCAM-1 on microvascular endothelium. Induction of adhesion molecules by NiCl2 was found to depend on de novo mRNA and protein synthesis and could be blocked by the protein kinase inhibitor H-7 in a dose-dependent manner but not by HA-1004 and staurosporine. An autocrine IL-1-dependent mechanism mediating NiCl2 effects could be excluded. Our data demonstrate that allergens as NiCl2 and CoCl2 are capable of directly activating endothelium which is an important step in evolving inflammatory reactions and may thus be of relevance for the pathogenesis of contact hypersensitivity.

Allergens↗
PubMed1993

Formation of autophagosomes during degradation of excess peroxisomes induced by di-(2-ethylhexyl)phthalate treatment. II. Immunocytochemical analysis of early and late autophagosomes.

We have investigated the autophagocytic process of excess peroxisomes and mitochondria induced by di-(2-ethylhexyl)phthalate (DEHP) treatment using immunocytochemical techniques. Rat liver peroxisomes were induced by 2 weeks treatment with DEHP. The animals were then injected with leupeptin (2 mg/100 g body weight), and their livers were fixed by perfusion at various intervals. The liver tissues were embedded in LR White or Epon. Semithin sections of the Epon-embedded tissue were stained for cathepsin D, B, and H, and lysosomal glycoprotein (LGP107) by the immunoenzyme technique after removal of epoxy resin. Thin sections of LR White-embedded tissue were stained for the same antigens by the immunogold technique. Some liver specimens were processed to ultracryotomy, and frozen-thawed thin sections were immunostained for carboxylesterase E1 and alpha-glucosidase II, endoplasmic reticulum (ER) markers. Twenty minutes after leupeptin injection, many peroxisomes and mitochondria were surrounded by a double-layered membrane (isolation membrane) continuous with the ER. These membranes were positive for carboxylesterase E1 and alpha-glucosidase, but not for LGP107 as well as cathepsins. Forty to 60 minutes after leupeptin injection many autophagic vacuoles showing various developing stages appeared and accumulated. The early autophagic vacuoles were surrounded by a double-layered membrane, whereas the late autophagic vacuoles had a single limiting membrane. The former was negative for cathepsins as well as LGP107, but positive for carboxylesterase E1 and alpha-glucosidase II. The results suggest strongly that the isolation membrane is derived from the ER membrane and converted later into the lysosomal membrane and support our previous morphological observations.

Animals↗
PubMed1993

[Risk of development of colorectal carcinoma in patients with ulcerative colitis].

In patients with ulcerative colitis of prolonged duration and major extent there is according to the majority of investigations an increased risk of development of colorectal carcinoma; the magnitude of the risk which is of major importance for clinical practice, however, differs according to different authors. The present study comprises 189 patients with ulcerative colitis, 103 men and 86 women, perspectively followed up for a period of 12.5 years (8.0-24.5). In 60 patients the distal form was present, in 68 left-sided colitis and in 61 pancolitis. The patients were monitored systematically--clinically colonoscopically and endoscopically. The intervals between these check-ups were gradually shorter when the disease persisted for 10 or 12 years, i.e. the patients were checked once to twice a year. The endoscopic findings were focused in particular on evidence of dysplasia. The follow-up system was modified with regard to individual conditions. In the course of the follow-up colorectal carcinoma was detected in 9 patients (4.8%) with a persistence of the disease for 9-25 years (in one patient after 9 years, in 5 after 10-20 years and in 3 after longer periods). In three instances the left-sided form was involved, in 6 pancolitis. Dysplastic changes were mostly medium grade and were found at least once in all patients. The preoperative diagnosis of carcinoma was established for certain in three patients, there was major suspicion in four patients. In two patients the carcinoma was detected only on operation (in active forms of the disease). All carcinomas were resectable, 4 times DUKES A, 4 times B, once C. As to the remaining 180 patients, 32 were operated on account of colitis; in 28 at least once dysplasia was proved, with a rising trend as the disease had a prolonged duration. These results confirm the increased risk of carcinoma in ulcerative colitis with a long duration and with a major extent and justify systematic colonoscopic and endobioptic follow-up of these patients.

Adolescent↗
PubMed1993

Endocrine pancreatic tumors in MSV-SV40 large T transgenic mice.

Mice carrying a Moloney murine sarcoma virus-(MSV) simian virus 40 large T transgene develop heritable tumors including endocrine pancreatic tumors. We have established several independent transgenic mouse lines expressing this transgene. One of these lines, designated MSV125, is characterized by the development of congenital cataracts and either pancreatic or brain tumors. The development and histopathology of the pancreatic tumors were studied by light microscopy and immunocytochemistry for large T antigen, neuron-specific enolase, insulin, proinsulin, glucagon, somatostatin, pancreatic polypeptide, gastrin, and serotonin. The 23 tumors examined were similar to human endocrine pancreatic tumors with respect to their macroscopic and histological features. We classified 91% of the tumors as insulinomas based on the predominance of insulin immunoreactivity. In newborn and young transgenic animals, nesidioblastosis and islet cell proliferation, consisting mostly of insulin containing beta cells, was obvious and persisted into adulthood. In transgenic animals more than 2 months old, islet hyperplasia and dysplasia predominated from which single tumors developed. Hyperplastic and dysplastic islets were composed mostly of beta cells. Large T antigen was detectable not only in tumor cells, but also in cells of normal and hyperplastic islets and in islet anlagen of newborn transgenic mice, indicating expression of the transgene in the endocrine part of the pancreas. Large T antigen-immunoreactivity was restricted to the beta cells. Insulinomas of the MSV-simian virus 40 T antigen-derived MSV125 transgenic mouse line may represent a valuable model for the study of the development and biology of insulinoma.

Animals↗
PubMed1993

The Omnicarbon tilting-disc heart valve prosthesis. A clinical and Doppler echocardiographic follow-up.

From 1986 to 1990, 172 patients with a median age of 60.5 years (range 20 to 79 years) received 187 Omnicarbon valves (109 aortic valve replacements, 48 mitral valve replacements, and 15 double valve replacements). Patients were followed-up for a median observation period of 2.5 years (range 4 months to 5.2 years) by clinical and Doppler echocardiographic examination. Follow-up was complete in 98%. Operative mortality (death within 30 days) was 1.7%, and linearized late mortality was 2.6% per patient-year, corresponding to an actuarial survival rate for operative survivors of 89% after 4 years. The overall 4-year postoperative survival was 87% (93% for aortic valve replacement, 77% for mitral valve replacement). Compared with age- and sex-adjusted Swiss death rates, there was an excess mortality of 5% after 4 years. Percentages for freedom from valve-related complications at 4 years are as follows: thromboembolism, 98% (aortic valve replacement, 98%, and mitral valve replacement, 96%); anticoagulant-related hemorrhage, 95%; valve endocarditis, 96%; reoperation, 96%; and permanent valve-related impairment, 99%. The overall 4-year event-free survival was 76% (80% for aortic valve replacement and 69% for mitral valve replacement). New York Heart Association class improved in 88% of the patients by 1 to 3 grades, and only 3% remained in class III after operation. For the most commonly used aortic valve (23 mm), Doppler echocardiography revealed a peak pressure gradient of 29 +/- 10 mm Hg, a fractional shortening/peak pressure gradient ratio of 1.34 +/- 0.61, and a performance index of 0.35 +/- 0.08. In the most commonly used mitral valve (27 mm), the mean pressure gradient was 4.0 +/- 2.1 mm Hg. We conclude that excellent clinical and hemodynamic results can be obtained with the Omnicarbon prosthesis, in both the aortic and mitral positions.

Adult↗
PubMed1992

[Heart valve substitution: the effect of preoperative findings on long-term outcome].

BACKGROUND: In a retrospective analysis of 653 consecutive patients who underwent heart valve replacement by one single type of mechanical prosthesis (St. Jude Medical) at three Swiss university medical centers (Basel, Bern, Lausanne), the outcome was judged on the basis of preoperative variables. These variables should facilitate the timing of heart valve replacement. METHODS: Preoperative evaluation includes NYHA classification of symptoms, chest X-ray, ECG, and LVEF on angiography. Postoperative outcome was assessed clinically at yearly intervals by NYHA classification, documentation of complications and mortality. RESULTS: Five-year-survival rates were 96 and 88%, and complication-free rates were 82 and 76% respectively in patients after isolated aortic and mitral valve replacement. An unsatisfactory outcome with death or persistent severe symptoms was more frequent when preoperative symptoms at rest and atrial fibrillation were present. CONCLUSION: Heart valve replacement should not be postponed until severe symptoms and functional impairment occur. Clinical criteria are at least as important for the timing of operation as the findings of more complex investigations.

Adolescent↗
PubMed1992

Rapid effects of insulin on cyclic GMP location in an intact protozoan.

We studied rapid changes in location of cyclic GMP in Tetrahymena pyriformis. Insulin caused cGMP localization in cilia and near the plasma membrane (0.5-1 min). Later (1-5 min) cGMP localization was diffuse in cytoplasm with perinuclear accentuation. Inactive insulin analogs did not elicit these changes.

1-Methyl-3-isobutylxanthine↗
PubMed1992

Polysialic acid is associated with sodium channels and the neural cell adhesion molecule N-CAM in adult rat brain.

We have studied alpha 2,8-linked polysialic acid (polySia) and the neural cell adhesion molecule (N-CAM) in the adult rat brain by immunohistochemistry and Western blot analysis. Both molecules were widely distributed but not ubiquitous. Various brain regions showed colocalization of polySia and N-CAM. Strong immunoreactivity for polySia was seen in regions which were negative for N-CAM, such as the main and accessory olfactory bulbs. Immunohistochemical evidence for the heterogeneity of polySia expression in different brain regions was confirmed by immunoblotting. We present evidence that N-CAM is not the only polySia bearing protein in adult rat brain. Specifically, immunoprecipitation using the polySia-specific monoclonal antibody mAb 735 precipitated not only N-CAM isoforms carrying polySia, but also the sodium channel alpha subunit. Immunoblotting using sodium channel alpha subunit antibody (SP20) revealed a smear from 250 kDa upwards. PolySia removal using an endoneuraminidase specific for alpha 2,8-linked polysialic acid of 8 or more residues long, reduced this smear to a single band at 250 kDa. Thus both N-CAM and sodium channels carry homopolymers of alpha 2,8-linked polysialic acid in adult rat brain.

Animals↗
PubMed1992

Occurrence of sialic acids in Drosophila melanogaster.

Sialylated oligosaccharides, which are cell type-specific and developmentally regulated, have been implicated in a variety of complex biological events. Their broad functional importance is reflected by their presence in a wide variety of phyla extending from Echinodermata through higher vertebrates. Here, sialic acids are detected throughout development in an insect, Drosophila. Homopolymers of alpha 2,8-linked sialic acid, polysialic acid, are developmentally regulated and only expressed during early Drosophila development.

Animals↗
PubMed1992

[Botulinum toxin in the treatment of blepharospasm. Initial experience].

The clinical effects of botulinum toxin A were evaluated in eight patients with idiopathic blepharospasm and hemifacial spasm. A substantial reduction or disappearance of muscle spasms were observed after the treatment. The action of botulinum toxin became noticeable 2 days after administration with a peak effect at 2 weeks. This effect diminished with muscle spasms returning about 12 weeks after administration. No serious adverse events were noted. The treatment with botulinum toxin has become method of choice in blepharospasm, it is proposed for the management of local muscle spasms of various origin.

Adult↗
PubMed1992

Subcellular distribution in rat liver of a novel broad-specificity (alpha 1----2, alpha 1----3 and alpha 1----6) mannosidase active on oligomannose glycans.

Recently, the purification to homogeneity was reported of a novel broad-specificity alpha-mannosidase from rat liver microsomal membranes [P. Bonay and R. C. Hughes (1991) Eur. J. Biochem. 197, 229-238]. The enzyme catalyzed the ordered removal of alpha 1----2-, alpha 1----3- and alpha 1----6-linked mannose residues from MannGlcNAc oligosaccharide substrates where n = 4-9. We now show by subcellular fractionation and immunocytochemistry that the novel mannosidase is present in the endoplasmic reticulum, Golgi apparatus and endosomes. Enzyme activity is enriched in a heavy Golgi membrane fraction and to lesser extent in an intermediate density Golgi membrane fraction containing GlcNAc transferase I activity and in a 'late' endosomal fraction. Low levels of enzyme activity were detectable in endoplasmic reticulum membranes and in 'early' endosomes but not in receptor-enriched and ligand-free endosomes. Assays of enzymic activity using Golgi membrane fractions in the absence and presence of Triton X-100 showed that the active site of the enzyme faces the lumen of the membrane vesicles. Antibodies directed against the purified mannosidase showed no immunological cross-reaction to known endoplasmic reticulum and Golgi mannosidases. Conversely, the purified mannosidase was not recognized by antibodies directed against endoplasmic reticulum mannosidase nor Golgi mannosidase IA.

Animals↗
PubMed1992

The calcium-binding proteins MRP8 and MRP14 form a membrane-associated heterodimer in a subset of monocytes/macrophages present in acute but absent in chronic inflammatory lesions.

Monocytes/macrophages expressing an epitope recognized by a monoclonal antibody 27E10 are present in acute but are absent in chronic inflammatory disorders. This report shows that the 27E10 antigen is formed by noncovalent association of the two Ca(2+)-binding proteins MRP8 and MRP14 which belong to the S100 protein family. Identification has been confirmed immunochemically, by matrix-assisted UV-laser desorption/ionization spectrometry and by partial amino acid sequencing. Surface expression of the MRP8/MRP14 complex on a subset of monocytes is reported for the first time and shown to be up-regulated in a Ca(2+)-dependent manner. The 27E10 surface-positive monocytes isolated by cell separation techniques release high amounts of tumor necrosis factor-alpha and interleukin-1 beta in contrast to their 27E10 surface-negative counterparts thus emphasizing their role in inflammation.

Acute Disease↗