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Biomedical subjects

M Roth

Publications and source records attributed to M Roth.

At least 145 records · Page 8Linked to original sources
PubMed1995

Focal white-matter lesions in brain of patients with inflammatory bowel disease.

Inflammatory bowel diseases are often associated with extra-intestinal manifestations, such as arthritis and iritis/uveitis. Using magnetic-resonance imaging we found hyperintense focal white-matter lesions in the brain in 20 of 48 (42%) patients with Crohn's disease, in 11 of 24 (46%) patients with ulcerative colitis, but in only 8 of 50 (16%) healthy age-matched controls (relative risk [95% CI] vs controls 2.6 [1.3-5.3] and 2.9 [1.3-6.2], respectively). These findings may represent another extra-intestinal manifestation of inflammatory bowel disease.

Adult↗
PubMed1995

Intracellular interleukin 6 mediates platelet-derived growth factor-induced proliferation of nontransformed cells.

The functional relevance of interleukin 6 (IL-6) in platelet-derived growth factor (PDGF)-induced cell growth was evaluated in cultures of human fibroblasts, vascular smooth muscle cells, and mesangial cells. The three isoforms of the PDGF--namely, PDGF-AA, -AB, and -BB--induced the expression of the IL-6 gene and proliferation of the nontransformed cells. PDGF-induced transcription, translation, and secretion of IL-6 were diminished in the presence of IL-6 antisense oligonucleotides. While neutralizing anti-IL-6 antibodies failed to affect the growth factor-dependent cell proliferation, IL-6 antisense oligonucleotides inhibited cell division. In addition, IL-6 antisense oligonucleotides abolished PDGF-induced transcription of the genes coding for the cell division cycle 2-related protein (CDC2) and proliferating cell nuclear antigen (PCNA), both of which are regulated in a cell cycle-dependent manner. It is concluded that PDGF-dependent proliferation of nontransformed cells involves the action of intracellular IL-6.

Base Sequence↗
PubMed1995

Parenteral nutrition alters monocyte TNF receptor activity.

The route of nutrient provision has been reported to influence some aspects of the host inflammatory response in both patient populations and normal subjects. The tumor necrosis factor receptor system is a complex regulatory mechanism that modulates the bioavailability of tumor necrosis factor (TNF). We sought to determine whether maintenance on total parenteral nutrition (TPN) can alter host response to endotoxin challenge, specifically as it relates to the TNF receptor system. Seventeen healthy men were randomized to receive either TPN (n = 8) or a defined formula enteral diet (ENT, n = 9) prior to intravenous infusion of endotoxin (Lot EC-5, 20 U/kg). The subjects that received 1 week of antecedent TPN exhibited an increased heart rate and temperature and decreased mean arterial pressure post-LPS compared to those subjects maintained on enteral nutritional support. The TPN subjects also exhibited comparatively higher TNF and interleukin-6 levels in response to endotoxin. Monocyte TNF receptor levels decreased in both groups post-LPS, but TPN subjects exhibited consistently greater expression of this functional membrane-associated TNF receptor. After LPS, soluble tumor necrosis factor receptor II (sTNFr II, p75) peaked three times higher in TPN subjects than in ENT subjects. Conversely, sTNFr I (p55) was higher in the enterally fed group. From these studies it appears that antecedent TPN not only influences clinical manifestations of endotoxin but also modulates the regulation of all associated TNF receptors and shedding of soluble receptors.

Adolescent↗
PubMed1995

Ca(2+)-channel blockers modulate the expression of interleukin-6 and interleukin-8 genes in human vascular smooth muscle cells.

Ca(2+)-channel blockers at therapeutic concentrations were shown to modulate several processes underlying inflammation, such as growth factor-mediated activation of genes coding for the low density lipoprotein receptor and 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase in human vascular smooth muscle cells (VSMC) (Block et al., 1991), and for interleukins in human mesangial cells (Roth et al., 1992). Two Ca(2+)-channel blockers, Manidipine (Roth et al., 1992) and Verapamil (Walz et al., 1990) have been shown to induce the expression of the gene coding for interleukin-6 (IL-6). Here we demonstrate that the four Ca(2+)-channel blockers, Amlodipine, Felodipine, Isradipine and Manidipine, at nanomolar concentrations, activate the transcription of the genes encoding IL-6 and IL-8 in primary human VSMC and fibroblasts. Ca(2+)-channel blocker-induced transcription is subsequently followed by secretion of the two ILs into the growth medium of the cells. In addition, we compared the action of the Ca(2+)-channel blockers with that of propranolol, a beta-adrenoceptor antagonist, or with furosemide, a diuretic, all of which are known to lower blood pressure. However, in contrast to the dihydropyridines, the two latter drugs failed to affect the expression of the two IL genes.

Adrenergic beta-Antagonists↗
PubMed1995

Bone metabolism in spinal cord injured individuals and in others who have prolonged immobilisation. A review.

Immobilisation or disuse is a condition known to be associated with a decrease in bone mass, osteopenia and in some people leading to osteoporosis with an increased risk of fractures. In this condition, previous histomorphometric and biochemical reports have shown an uncoupling between bone formation and resorption, but the exact sequence of the events resulting in bone loss is still not fully understood. In spinal cord injury for instance, the main finding soon after the onset is decreased osteoblastic activity associated with a dramatic increase in bone degradation. The overall consequence of these metabolic events is the development of a rapid and severe osteoporosis only observed in the paralysed part of the body associated with the loss of biomechanical strength and the biosynthesis of a structurally modified matrix which is unable to sustain normal mechanical stress. This situation dramatically increases the risk of fractures. The same uncoupling phenomenon has been described in healthy individuals who have been submitted to long duration bedrest and also in astronauts during spaceflight; but the timing, intensity and the metabolic subset may be different as these people do recover after cessation of the disuse period, which does not occur in paralysed patients. As new accurate and sensitive non-invasive techniques have become available recently to assess bone and connective tissue metabolism, more information is now available regarding bone loss in paralysed and/or immobilised individuals. These techniques should be definitely helpful in orientating new therapeutic trials with drugs and/or procedures intended to correct the musculoskeletal deleterious effects of disuse. This paper is therefore aimed at a review of bone metabolism in those with a severe spinal cord injury, or with a long duration of bedrest, or with loss of biomechanical function, or with actual or simulated spaceflight, in all instances using non-invasive techniques.

Bed Rest↗
PubMed1995

Recombinant hirudin and front-loaded alteplase in acute myocardial infarction: final results of a pilot study. HIT-I (hirudin for the improvement of thrombolysis).

Recombinant hirudin, a specific thrombin inhibitor, has been shown to accelerate thrombolysis and reduce reocclusions in experimental models. In a pilot trial recombinant hirudin (HBW 023) was used as an adjunctive therapy to thrombolysis with front-loaded tissue plasminogen activator (t-PA) (100 mg.90 min-1) in 40 patients with acute myocardial infarction whose duration of symptoms was less than 6 h. Patients received a bolus of r-hirudin of 0.07 mg.kg-1 b.w. followed by an infusion of 0.05 mg.kg-1.h-1 over 48 h. Complete patency (TIMI grade 3) of the infarct-related artery at 30, 60 and 90 min after the start of thrombolytic therapy was seen in 38.5%, 64.1% and 71.0% of patients, respectively. After 24-48 h, 80% of patients had a complete patent infarct vessel. A very early, complete and sustained patency (TIMI grade 3 at 60 and 90 min and at 24-48 h) was observed in 55% of patients. Reocclusions during the hirudin therapy appeared in six (16.1%) patients, two of whom had a PTCA at 90 min. The only reinfarction was seen after 6 h; this was successfully treated with additional thrombolysis. Major bleedings, mostly related to the invasive procedure, were observed in three patients. Spontaneous organ bleedings and intracerebral haemorrhages did not occur. There was one in-hospital death due to a late retroperitoneal bleeding. In was concluded that, with regard to safety and efficacy, the general feasibility of r-hirudin as adjunctive therapy to thrombolysis with front-loaded t-PA, has been demonstrated.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Absence of abnormal hyperphosphorylation of tau in intracellular tangles in Alzheimer's disease.

Adult human nerve cells contain tau protein, a phosphorylated microtubule-associated protein, that is hyperphosphorylated in the fetus and in patients with Alzheimer's disease. Hyperphosphorylation, which diminishes the microtubule-binding capacity of tau, destabilizes microtubules and may enhance the formation of paired helical filaments that constitute neurofibrillary tangles in Alzheimer's disease. Here, we use phosphorylation-dependent anti-tau antibodies to detect specific epitopes that characterize hyperphosphorylated tau. Our demonstration of intracellular tangles containing full-length tau that are not immunolabeled by these antibodies suggests that hyperphosphorylation of tau is not obligatory in the formation of neurofibrillary tangles in Alzheimer's disease.

Aged↗
PubMed1995

Long-term follow-up after a drug trial for panic disorder.

BACKGROUND: This study investigates the naturalistic course of panic disorder over four years and attempts to identify predictors for outcome. METHOD: 423 DSM-III-R panic disorder patients who had taken part in an international multicentre drug trial were selected for follow-up; we were able to re-interview 367 (87%). For panic attacks, phobic avoidance and disabilities the same rating scales were administered as had been used for the clinical trials. RESULTS: While 61% of all patients experienced at least occasional panic attacks at follow-up, few suffered from serious phobic avoidance (16.7%) or serious disabilities (work 7.9%); family 8.7%; social 13.9%). Panic attack frequency at baseline, original trial medication and continuous use of psychotropic medication during follow-up are not related to outcome, whereas longer duration of illness and more severe phobic avoidance at baseline are unfavourable. CONCLUSION: The course of panic disorder is not uniform. Since long duration of illness and severe phobic avoidance at baseline are predictors for an unfavourable outcome, more rigorous efforts should be undertaken to detect and treat panic disorder at an early stage.

Adolescent↗
PubMed1995

Advantages and disadvantages of three-dimensional computed tomography intraoperative localization for functional endoscopic sinus surgery.

Intraoperative three-dimensional computed tomography (3-D-CT) localization has been available for use during functional endoscopic sinus surgery (FESS) for several years, although relatively few otolaryngologists operate in conjunction with this technology. Proponents of intraoperative localization believe that operating with stereotaxis enhances surgical precision and reduces complications. A 1-year review was conducted at the University of Pennsylvania from January 1994 through January 1995. During this period 5% of sinus operations were performed in conjunction with intraoperative localization. The advantages and disadvantages of using intraoperative localization were evaluated for each case. Also examined were type and indication for surgery, anesthesia used, added time, and cost. Overall, intraoperative localization was found to be helpful when anatomy was distorted or obscured. However, selecting patients who may have benefited from localization was often not possible using preoperative data. Ideally, localization should be available for all FESS. Criteria are outlined which will need to be met prior to localization becoming a significant aspect of FESS.

Adult↗
PubMed1995

Treatment of active Crohn's ileocolitis with oral pH-modified budesonide. Germany Budesonide Study Group.

Budesonide is a topical steroid which after intestinal absorption is rapidly degraded into inactive metabolites in the liver. Its systemic bioavailability is only 10-15%. In the present open trial the efficiency and safety of oral pH-modified release budesonide were assessed in patients with active Crohn's ileocolitis. This report describes the results of the first 30 of 78 patients. After 6 weeks of treatment with 3 x 3 mg budesonide/day 67% of the patients were in clinical remission. Typical steroid-related side effects were observed in only one patient. Budesonide therefore seems to be suited as an alternative for classical steroids in patients with Crohn's ileocolitis. Its clinical efficacy is comparable with classical steroids but it's rate of steroid-related side effects is lower.

Administration, Oral↗
PubMed1994

Crystal structure of the ferredoxin I from Desulfovibrio africanus at 2.3 A resolution.

The crystal structure of the ferredoxin I from the sulfate-reducing bacterium Desulfovibrio africanus (DaFdI) has been solved and refined by X-ray diffraction. The crystals are orthorhombic with a = 96.6 A, b = 58.1 A, and c = 20.7 A, space group P2(1)2(1)2, and two ferredoxin molecules per asymmetric unit. The initial electron density map has been obtained by combining phasing by molecular replacement methods, anomalous scattering, and noncrystallographic averaging. The final crystallographic R factor is 0.182 with 10-2.3 A resolution data. In parallel, the amino acid sequence was redetermined. This showed that DaFdI contains 64 residues (instead of 61) including one free cysteine, one histidine, and one tryptophan in the C-terminal part of the molecule. The current molecular model includes the two molecules of the asymmetric unit, 67 water molecules, and one sulfate ion. The DaFdI overall folding very closely resembles that of ferredoxins of known structure. Comparisons with the single cluster ferredoxins from Desulfovibrio gigas and Bacillus thermoproteolyticus show that the presence or the absence of a disulfide bridge does not significantly affect the folding of the other half of the molecule, including the characteristic alpha-helix of the single cluster ferreddoxins. Like other ferredoxins or analogs, the [4Fe-4S] iron--sulfur cluster presents, at 2.3 A resolution, a cubane-like geometry. By contrast, its immediate environment is different as it includes, besides the four cysteic sulfur ligands, the sulfur atom of the free cysteine. This sulfur atom, which is buried within the protein, is in van der Waals contact with one labile sulfur of the cluster and one liganded cysteic sulfur. The association of a [4Fe-4S] cluster with one free cysteic sulfur is similar to that previously found in both X-ray structures of Azotobacter vinelandii and Peptococcus aerogenes [Stout, C. D. (1989) J. Mol. Biol. 205, 545-555; Backes, G., et al. (1991) J. Am. Chem. Soc. 113, 2055-2064]. Chemical sequence analysis suggests that this characteristic [4Fe-4S] cluster sulfur environment is widely distributed among ferredoxins.

Amino Acid Sequence↗
PubMed1994

Presence of axonal paired helical filament-tau in Alzheimer's disease: submicroscopic localization.

While normal adult tau protein is found typically in axons, paired helical filament (PHF) tau has been shown immunohistochemically to be in the somatodendritic compartment in Alzheimer's disease (AD). The small amount of PHF-tau (8-11%) found in white matter with immunochemical methods is shown here by immunoelectron microscopy to be located in axons. It is localized to straight filament variants of PHFs. The small amount of PHF-tau in white matter, therefore, appears not to result from the contamination of immunochemical preparations but to be an integral constituent of affected axons in AD.

Alzheimer Disease↗
PubMed1994

DNA topoisomerases from Streptomyces noursei: influence of coumarins and quinolones on the enzymic activity.

DNA topoisomerases have been purified from Streptomyces noursei. DNA gyrase and topoisomerase I show a differential sensitivity against quinolones and coumarins compared to the E. coli enzymes. Streptomyces gyrase is resistant to much higher levels of various drugs than is the E. coli enzyme. The observed differences between the gyrases from streptomycetes and E. coli are discussed in the light of present literature data.

Coumarins↗
PubMed1994

A granulocyte inhibitory protein overexpressed in chronic renal disease regulates expression of interleukin 6 and interleukin 8.

Growing evidence suggests that cytokine expression is influenced by locally produced mediators, thus modifying the pluripotential effects of cytokines toward a tissue-specific inflammatory reaction. The granulocyte inhibitory protein (GIP), a 23-kDa protein found to be significantly overexpressed in patients with chronic renal failure, increases autocrine transcription and expression of interleukin (IL) 6 and IL-8 in human mesangial cells. Moreover, GIP alone induced the transcription of c-jun mRNA; however, in combination with IL-6, it stimulated de novo synthesis of DNA and the transcription of both c-jun and c-fos genes. The data suggest that the overall effect of GIP results in the modulation of the glomerular response to injury and contributes to the progression of glomerulosclerosis.

Cells, Cultured↗
PubMed1994

The vascular nervous skeleton: a disregarded factor of vascular pathology.

The nervous supply of the vascular wall in its organ entirety represents the felt-like 'nervous skeleton'. Its growth is more vulnerable than that of any other tissue component of the developing vessel wall. Selective growth impairment of the vascular nervous skeleton should result in developmental vascular stenosis. Escape of the epithelial or smooth muscle cells from the confines of the nervous skeleton should be taken into account as a possible common denominator of carcinogenesis and atherogenesis.

Arteriosclerosis↗