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Biomedical subjects

P Weber

Publications and source records attributed to P Weber.

At least 235 records · Page 13Linked to original sources
PubMed1989

Catalase activity in human spermatozoa and seminal plasma.

Catalase activity was determined in human semen by measuring the oxygen burst with a Clark electrode, after H2O2 addition. Significant catalase activities (mean +/- SD) were found in migrated, motile spermatozoa (44 +/- 17 nmoles O2/min/10(8) cells) and in seminal plasma of normozoospermic men (129 +/- 59 nmoles O2/min/ml). It has been demonstrated that seminal catalase originated from prostate; however, its activity was not correlated with the usual prostatic markers (such as citric acid and zinc). Our data suggest a multiglandular function secreted by this organ. The catalase activities measured in seminal samples from asthenozoospermic, infertile men were found lower than those from normozoospermic subjects. The understanding of the relative contribution of the different enzyme systems against O2 toxicity (superoxide dismutase, catalase, glutathione peroxidase) seem to be a priority area of research to understand disturbances of sperm function.

Biomarkers↗
PubMed1989

Investigation by NMR spectroscopy of the interaction between synthetic soluble (-)-dopa melanin and drugs.

In order to understand the molecular interactions of drugs with melanin, synthetic soluble (-)-dopa-melanin was prepared in deuterium buffer. The spectra of various drug moieties with the pigment at 30 degrees C were studied employing the line width measurements obtained with a pulse NMR (AF270) instrument. As compared to drug effects in fresh melanins (48 h), the aged melanins (greater than or equal to 168 h) gave consistent spectral measurements, even in dilute solutions of pigment. NMR signals of aromatic and N-methyl protons of drugs were relatively easy to quantify and, in the presence of melanin, line broadening of various drug moieties occurred. The line widths of the N-methyl groups of acetylcholine (3.02 ppm), the N-methyl group of atropine (2.52 ppm), N-isopropyl of isoprenaline bitartrate (1.14 ppm) and N-ter-butyl of timolol maleate (1.22 ppm) in the presence of the pigment were increased. Line widths associated with acetate, bitartrate, maleate or tropic acid, however, were not altered by the melanin. This indicates the specificity of the interaction between drug moieties and the site(s) of melanin. Based on the line width measurements of N-methyl protons of ephedrine, two dissociation constants were obtained (Kd1 2.08 mM and Kd2 greater than 20 mM). The constants for atropine melanin complex were Kd1 0.79 mM and Kd2 greater than 6 mM. Furthermore, based on N-methyl resonances, it appears that atropine and ephedrine compete for at least one common interacting site of the melanin polymer.

Acetylcholine↗
PubMed1989

Serum bactericidal activity against Enterobacteriaceae producing broad-spectrum beta-lactamases in volunteers administered ofloxacin and cefotaxime, alone or combined.

The activity of ofloxacin and cefotaxime, alone or combined, against four strains of Enterobacteriaceae was evaluated both in vitro and in sera from volunteers given a single infusion over 30 min of 200 mg ofloxacin or 1 g cefotaxime. The strains showed resistance or decreased susceptibility to third-generation cephalosporins. The combination was not found to be synergistic in vitro. Analysis of the bactericidal titres and killing kinetics of sera taken at the time of the peak concentration and 6 h after the infusion, respectively, confirmed the absence of synergy between the drugs against these strains.

Cefotaxime↗
PubMed1989

Automated analysis of 2,3-diamino-2,3-dideoxy-D-glucuronic acid by cation exchange chromatography with fluorometric postcolumn derivatization.

2,3-Diamino-2,3-dideoxy-D-glucuronic acid (diaminoglucuronic acid) occurs as its di-N-acetyl derivative as a unique constituent of some bacterial cell walls. A sensitive chromatographic method for its determination is described. Diaminoglucuronic acid was well separated from glucosamine and galactosamine in about 80 min on a Dionex DC-6A cation exchange column (0.9 x 18 cm, 50 degrees C) with a sodium citrate buffer (pH 5.28) containing boric acid (0.2 M). The amino sugars in the eluate were monitored fluorometrically by postcolumn derivatization with orthophthalaldehyde detection reagent. This method allowed the automated determination of 50-100 pmol of glucosamine, galactosamine, and diaminoglucuronic acid and was applied successfully to the analysis of diaminoglucuronic acid in Propionibacterium acnes cells.

Amino Acids↗
PubMed1989

In-vitro activity of pristinamycin and its components against gram-negative anaerobic bacilli and Gardnerella vaginalis.

The comparative in-vitro activities of pristinamycin, its components pristinamycins I and IIA, erythromycin, clindamycin and metronidazole were studied against 174 clinical isolates of Gram-negative anaerobic bacilli and 24 strains of Gardnerella vaginalis. Susceptibilities were determined with an agar-dilution method. Against Bacteroides and Fusobacterium, pristinamycin was slightly less active than both clindamycin and metronidazole and more active than erythromycin. Against G. vaginalis, the activity of pristinamycin was similar to that of clindamycin and slightly inferior to that of erythromycin. Both pristinamycins I and IIA alone were generally inactive against the strains tested. Additionally, MICs for the B. fragilis group determined by a broth microdilution technique were one to two log2 lower than MICs obtained by agar-dilution. The bactericidal activity of pristinamycin and clindamycin was moderate and varied according to the strains tested. The chequerboard broth microdilution test against 20 strains of the B. fragilis group confirmed the synergy between pristinamycins I and IIA at every PI/PIIA ratio. Along with the activity against Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma and both aerobic and anaerobic Gram-positive bacteria, our results suggest that pristinamycin could be an effective drug in the treatment of gynaecological infections.

Anti-Bacterial Agents↗
PubMed1989

Diagnosis of fistulae and sinus tracts in patients with Crohn disease: value of MR imaging.

To investigate the potential of MR imaging in the evaluation of sinus tracts or fistulae associated with Crohn disease, 17 patients with pelvic or abdominal fistulae or sinus tracts underwent MR imaging with multislice spin-echo techniques, 500/15 and 1600/22,80 (TR/TE). The presence of fistulae and/or sinus tracts was confirmed by contrast-enhanced CT (n = 17) and/or sonography (n = 8), sinography (n = 6), or barium studies (n = 4). In all but three cases the fistulae and extramucosal inflammatory abnormalities were shown by MR. T1-weighted images provided excellent delineation of the extension of the fistulae relative to sphincters and adjacent hollow viscera and showed inflammatory changes in fat planes. T2-weighted images showed fluid collections within the fistulae, localized fluid collections in extraintestinal tissues, and inflammatory changes within muscles. The supralevator and infralevator compartments were well defined on coronal images. Thus, the perirectal spread of fistulae and sinus tracts with respect to the levator ani could be demonstrated in all cases. Our results suggest that MR imaging is useful for the demonstration and evaluation of pelvic and abdominal sinus tracts or fistulae associated with Crohn disease.

Abscess↗
PubMed1989

Pharmacokinetics of rioprostil in human plasma as assayed by combined capillary gas chromatography-negative ion chemical ionization mass spectrometry.

To investigate the pharmacokinetics of rioprostil in man an assay is developed to analyse levels of rioprostil in plasma. After extraction and purification by solid-phase cartridges rioprostil is measured by negative ion chemical ionization mass spectrometry using a deuterated internal standard. The method is validated by a recovery experiment. Levels of rioprostil in the plasma of four volunteers following a single oral dose of 600 micrograms rioprostil are found as always below 100 pg/ml. The data presented here suggest that rioprostil is transformed rapidly in man to its more polar metabolites.

Adult↗
PubMed1989

The fine structure of the body wall of adult Paragonimus uterobilateralis.

The body wall of adult Paragonimus uterobilateralis was investigated by electron microscopy. The syncytial tegument contains prominent spines, mitochondria and disc-shaped granules. The apical surface forms ridges and pits, the basal membrane forms a conspicuous labyrinth. A layer of interstitial material with muscle fibres separates the syncytium from the parenchyme. The muscle fibres are organized in a transverse and a longitudinal layer and single radial fibres. Thick and thin myofilaments do not show any regular pattern. Tegumental and muscle cell bodies lie in clusters below the interstitial material. Tegumental cells are characterized by abundant ribosomes and granules, muscle cells are stacked with mitochondria. Cytoplasmic connections link both cell types to their functional portions.

Animals↗
PubMed1989

[A case of cholestatic hepatitis caused by amiodarone].

The authors report the case of a 70 year old male patient, who was treated with amiodarone for 9 months (200 mg/d-5 days/7) for alcohol-induced hypokinetic cardiomyopathy, complicated by ventricular dysrhythmia and hospitalized for jaundice, pruritus, and deterioration of his general condition. Alkaline phosphatases were elevated significantly (7 times the upper limit for normal) with a moderate rise in serum transaminases twice the upper limit for normal). Ultrasound of the liver and biliary tract was normal. There were no serum markers for hepatitis B virus. No anti-tissue antibodies were found. A liver biopsy revealed portal and septal fibrosis, and polymorphous inflammatory infiltration with a majority of polymorphonuclear neutrophils and Mallory bodies. Intracellular and intralysosomal phospholipid inclusions were observed with electron microscopy. Clinical and laboratory test value outcome was favorable two weeks after cessation of administration of amiodarone.

Aged↗
PubMed1989

[Hyperinsulinemia in cirrhosis--increased secretion or impaired liver extraction?].

The authors applied the oral glucose tolerance test (oGTT) in 21 patients with bioptically confirmed cirrhosis without clinical or laboratory signs of manifest diabetes. At the same time they used the oGTT in 11 healthy controls. During the test they assessed the venous glycaemia, insulin and C-peptide and from these values they calculated relative indexes. In cirrhotic patients they recorded during the oGTT higher blood sugar levels, and higher insulin and C-peptide in the majority of time intervals [blood sugar during the 90th minute p greater than 0.01 and 120th minute p greater than 0.05; immunoreactive insulin (IRI) in the 90th minute p greater than 0.05 and in the 120th minute p greater than 0.01), i.e. typical hyperinsulinaemia with a retarded secretory maximum during the 90th minute. The calculation of the molar ratio C-peptide: IRI is considered useful by the authors. In cirrhotic patients it was markedly reduced on fasting, during the 60th, 90th and 120th minute (p greater than 0.01). In the discussion the authors analyze the problem of enhanced insular secretion, impaired hepatic extraction and insulin resistance in relation to disorders of glucose tolerance in cirrhosis.

Adult↗
PubMed1989

[Paroxysmal march hemoglobinuria--a 1-year duration in a young man].

The development of paroxysmal march hemoglobinuria in a young man is described. It first appeared when he was 31 years old and lasted for over one year. It was induced only by long walking (half an hour and more) on paved city streets and did not appear after any other physical exertion. Apart from the dark urine, the condition had a completely asymptomatic course and after one year it spontaneously disappeared. The practical implication of differentiating hemoglobinuria from other potential causes resulting in dark coloration of urine, such as hematuria, porphyrinuria and myoglobinuria, is being emphasized. The discussion presents a concise analysis of the problem of hemolysis developing as a result of mechanical damage to erythrocytes, particularly with regard to paroxysmal march hemoglobinuria. (Ref. 18.).

Adult↗
PubMed1989

[The somatotropic hormone and liver diseases].

The authors examined in 1980-1988 a total of 114 patients aged 18-87 years suffering from chronic liver disease. In all these patients they examined in addition to RIA assay of somatotropic hormone (STH) bilirubin and basic liver enzymes, using common methods. They recorded a significant increase of STH in patients with cirrhosis of the liver. In the other diagnostic groups the STH levels were within the reference zone or at its upper borderline. The authors analyzed also STH levels in relation to diabetes and drew attention to its frequent occurrence (type II) in patients with cirrhosis of the liver. The authors analyze also STH variations in the course of ageing.

Adolescent↗
PubMed1988

[Pericardial effusion during the therapy of Crohn's disease with 5-aminosalicylic acid].

A 22-year-old woman with Crohn's disease was treated with 5-aminosalicylic acid (Claversal), four times 500 mg daily, because of increased inflammatory activity. Retrosternal pain set in after two weeks; in another two weeks a moderately enlarged heart was noted on the chest X-ray and pericardial effusion diagnosed echocardiographically. After stopping the medication the pericardial effusion resolved without further treatment. Immunoserology failed to demonstrate autoantibodies, but a repeat lymphocyte stimulation test was positive. There is a possible causal relationship between 5-aminosalicylic acid medication and the pericardial effusion, although the pathogenetic mechanisms is not known.

Adult↗