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Biomedical subjects

M Scheurlen

Publications and source records attributed to M Scheurlen.

65 records · Page 4Linked to original sources
PubMed1985

Oxprenolol absorption in man after single bolus dosing into two segments of the colon compared with that after oral dosing.

The systemic availability of oxprenolol after colonic and oral administration has been compared in a crossover study involving six healthy male volunteers. Drug administration into two regions of the colon (caecum and left flexure) was achieved by means of a colonoscopic technique. There were no obvious differences in plasma concentrations after drug administration to the caecum and left flexure, although in one subject it was necessary to repeat colonic administration because of unexpectedly high plasma drug levels on the first occasion. The possible reasons for this abnormal response are discussed. The mean systemic availability of oxprenolol was 82% after colonic compared with oral dosing, although marked differences were observed in individual plasma levels following drug administration by the two routes. The results of this study support the concept of extending the duration of oxprenolol release from a rate-controlled dosage form to permit once-daily administration with this short elimination half-life drug.

Administration, Oral↗
PubMed1984

Simple radioligand binding assay for the determination of urinary scopolamine.

A sensitive radioligand binding assay is described for the determination of scopolamine in human urine. As a measure for the drug concentration, the quantitative displacement of scopolamine of tritiated quinuclidinyl benzylate from rat brain receptors was used. The assay is sensitive to concentrations as low as 1.2 ng/mL, surpassed only by GC-MS techniques. It can be performed easily and quickly and does not include extraction procedures. Scopoline and scopine , possible metabolites of scopolamine, do not interfere with the assay. After transdermal administration of scopolamine, 34% of the drug is found in the urine. Of the total scopolamine excreted, 79% is conjugated to glucuronic and/or sulfuric acid and 21% is excreted in the unbound form.

Administration, Topical↗
PubMed1979

Low molecular weight RNAs as components of nuclear ribonucleoprotein particles containing heterogeneous nuclear RNA.

70-130 S polyparticles as well as 38 S monoparticles were isolated from rat liver nuclei and analyzed in respect to their RNA components by microgel polyacrylamide electrophoresis in formamide. In addition to the high molecular weight polydisperse hnRNA of polyparticles several low molecular weight RNAs (snRNA) were detected. There are at least six distinct snRNA species in polyparticles. Except for one species, which is missing, 38 S monoparticles showed a similar snRNA pattern. From densitometer tracings of microgels the snRNAs were estimated to represent about 11% of the total polyparticle RNA. The number of nucleotides for the various snRNAs were determined from a plot of relative electrophoretic mobility versus log number of nucleotides. The possibility that the snRNAs are degradation products of the hnRNA was excluded on the basis of the following findings. (1) The snRNA pattern was similar in mono- and polyparticles. (2) Whereas the hnRNA of polyparticles incubated at 37 degrees C was extensively degraded, the snRNA did not show a corresponding increase. (3) After a 30 min pulse with [3H]orotate the hn RNA was readily labeled; none of the snRNAs, however, incorporated radioactivity. The snRNAs were still found after treatment of polyparticles with 2 M NaCl excluding contamination by nucleoplasm.

Animals↗
PubMed1978

Studies on the preparation and properties of ribonucleoprotein particles from rat liver nuclei.

Ribonucleoprotein particles of 38 S were extracted from rat liver nuclei with isotonic salt buffer under concomitant sonication. The fate of the endogeneous nuclear RNAases assayed with poly(A), high molecular weight yeast RNA and rapidly labeled hnRNA was followed during the preparation of 38-S nuclear ribonucleoprotein (nRNP) particles. Essentially all the RNAase activity could be removed from the particle preparation. The effect of synthetic RNAase inhibitors on the nRNP particles was studied. Upon extraction of nuclei with 0.14 M NaCl, approximately 38% of the total nuclear radioactivity was found in the 38-S nRNP particles. By two successive extractions of the remaining chromatin with either isotonic or 0.22 and 0.3 M NaCl, an additional 25 and 9% of rapidly labeled hnRNA of 38 S particle were dissociated from chromatin, respectively. The chromatin components, DNA, nonhistone proteins, histones and RNA were determined after successive salt extractions. Particularly alterations in the nonhistone proteins and RNA were found. The protein patterns upon SDS-acrylamide gel electrophoresis of the salt-extracted chromatin preparations were compared with those of the 38-S nRNP particles. Particularly proteins in the molecular weight range of 32 000-43 000 were dissociated from chromatin after treatment with 0.22 or 0.3 M NaCl.

Animals↗
PubMedDate not supplied

Emotional state, coping styles, and somatic variables in patients with chronic hepatitis C.

The authors in a cross-sectional study examined 113 patients with chronic hepatitis C (CHC) without widely progressed or decompensated liver disease. The patients were investigated for emotional state (depression, anxiety, coping styles) and somatic/sociodemographic variables. A high percentage of patients had positive scores for depression (22.4%) and anxiety (15.2%). Mode of acquisition (e.g., former drug abuse) and histological grade of liver damage had no significant influence on emotional state or coping strategies. Older patients (> or = 50 years) were significantly more depressed (P = 0.024). Patients with a recently diagnosed CHC (> 4 weeks, < 6 months) had significantly lower scores for depression (P = 0.003) and anxiety (P = 0.001) than the subgroup with a time interval since initial diagnosis of more than 5 years. Recently diagnosed CHC patients also showed the highest levels of problem-solving behavior. Patients who were advised not to undergo an interferon therapy were significantly more depressed (P = 0.001) and anxious (P = 0.028). Older patients with CHC and patients with a long period since CHC diagnosis or who were advised not to undergo interferon therapy should be carefully and regularly assessed for depression, anxiety, and inappropriate coping styles.

Adaptation, Psychological↗