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Biomedical subjects

P Müller

Publications and source records attributed to P Müller.

At least 253 records · Page 14Linked to original sources
PubMed1993

[Ultrasound velocity measurement in the diagnosis of postmenopausal osteoporosis].

We evaluated ultrasound transmission velocity as an indicator for osteoporosis at the os calcis of both feet and at the proximal phalanges of DII and DIII of both hands in 74 female subjects (22 premenopausal, 29 postmenopausal non-osteoporotic and 23 postmenopausal osteoporotic). In addition dual x-ray absorptiometry (DXA) of the lumbar spine was performed in 30 women and a combined cortical thickness index (CCT-index) of os metacarpale II was calculated from hand radiographs in 29 women. Ultrasound velocity at all sites slightly decreased in premenopausal women with age and declined significantly after menopause. At the hand postmenopausal osteoporotic women had significantly lower velocities than normal postmenopausal or premenopausal women while no difference could be seen at os calcis. An only poor or moderate correlation between ultrasound velocity at all sites and DXA of the lumbar spine and a good correlation between the CCT-index and velocity at the fingers indicate that ultrasound velocity is not only affected by bone density but even more by structural properties.

Absorptiometry, Photon↗
PubMed1993

Synergism and antagonism between N-methyl-N'-nitro-N-nitroso-guanidine and 9-aminoacridine in mutation induction in Escherichia coli K12.

When bacteria were treated simultaneously with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and low concentrations of 9-aminoacridine (9AA), the yield of frameshift mutations was much greater than that expected on the basis of independent action of both mutagens. In combination with a high concentration of 9AA, however, MNNG had an antagonistic effect upon the induction of frameshift mutations. There was no synergistic interaction between the two mutagens in bacteria in which the adaptive response to methylating agents had been induced. 9AA not only induced frameshift mutations, but also caused a small increase in reversions of a nonsense (ochre) mutation and, in combination with low MNNG concentrations, it had a small synergistic effect.

Aminacrine↗
PubMed1993

Influence of age and hemodynamics on myocardial blood flow and flow reserve.

BACKGROUND: Aging is associated with changes of the systolic blood pressure that may increase cardiac work and myocardial blood flow at rest and reduce the myocardial flow reserve. This might be misinterpreted as age-related impairment of the coronary vasodilator capacity. METHODS AND RESULTS: Myocardial blood flow was quantified at rest and after administration of intravenous dipyridamole in 40 healthy volunteers (12 women and 28 men) with 13N-ammonia and positron emission tomography. Eighteen of the normal subjects were less than and 22 were older than 50 years (31 +/- 9 versus 64 +/- 9 years). The resting rate-pressure product was lower in the younger than in the older subjects (6895 +/- 1070 versus 8634 +/- 1890; P < 0.01). Myocardial blood flow at rest averaged 0.76 +/- 0.17 mL.min-1.g-1 in the younger volunteers and 0.92 +/- 0.25 mL.min-1.g-1 in the older volunteers (P < 0.05). Hyperemic blood flows did not differ between younger and older subjects (3.0 +/- 0.8 versus 2.7 +/- 0.6 mL.min-1.g-1; P = NS); however, minimal coronary resistance was higher in the older subjects. Corrected for indexes of coronary driving pressure, hyperemic flow was lower in older than in younger normal subjects. The higher resting blood flows combined with similar hyperemic flows resulted in a lower myocardial flow reserve in the older than in the younger normal subjects (4.1 +/- 0.9 versus 3.0 +/- 0.70; P < 0.0001). The flow reserve was more closely correlated with resting than with hyperemic blood flows. CONCLUSIONS: Aging does not alter significantly dipyridamole-induced hyperemic flows; although coronary vascular resistance after dipyridamole was somewhat increased in older subjects. The gradual decline of the myocardial blood flow reserve correlates with an age-related increase of baseline myocardial work and blood flow. These findings suggest that the reduced flow reserve with age is primarily due to increased cardiac work and blood flow at rest rather than to an abnormal vasodilator capacity.

Adult↗
PubMed1993

Early neuroleptic intervention in schizophrenia: are prodromal symptoms valid predictors of relapse?

All recently completed controlled two-year studies on intermittent, early neuroleptic intervention treatment have failed to compare favourably with studies on maintenance treatment concerning relapse prevention. The reason for this failure is still unclear. Therefore the implicit, but as yet unproven, hypothesis that a relapse can be predicted from prodromal symptoms was tested from the perspective of our German multicentre study. Results demonstrate that this is not the case. Possible reasons for and clinical implications of this negative finding are discussed.

Adult↗
PubMed1993

[Nizatidine in therapy and prevention of non-steroidal anti-rheumatic drug-induced ulcers in rheumatic patients].

269 patients with various rheumatic disorders who had been treated with non-steroidal anti-inflammatory drugs (NSAID) for at least three weeks, were enrolled in this randomised double-blind multicenter trial. Entry criteria were both the presence of an ulcer in gastric and/or duodenal mucosa (> 3 mm and < 20 mm in diameter) as well as dyspeptic symptoms. The patients had been treated with 150 mg nizatidine nocte (n = 86), 2 x 150 mg/d (n = 93) and 2 x 300 mg/d (n = 90) nizatidine. All patients continued to take their original NSAID-medication. The three nizatidine-groups had been well matched with respect to important patient characteristics. After 8 weeks of treatment more than 90% of gastric and duodenal ulcers had been healed under all three nizatidine-dosages. There was a tendency for higher healing rates in case of gastric ulcers after 4 weeks following the higher dose of nizatidine. Erosions in stomach and duodenum as well as esophagitis had been improved to a similar degree with all nizatidine doses. The same holds with respect to improvement of clinical symptoms such as epigastric pain, heartburn etc. Consumption of additional antacids was similar in all three groups. In the subsequent prophylactic trial 237/221 patients had been followed for 3/6 months. 116/107 received in addition to their continued antirheumatic medication nizatidine 150 mg nocte and 121/114 patients 2 x 150 mg nizatidine daily. The cumulative relapse rates within 6 months averaged 5.5% in the low and 1.8% in the high dose group (n.s.).(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1993

[Circadian dependency of ibuprofen gastropathy and the protective effect of ranitidine. An endoscopic, controlled double-blind pilot study].

Circadian Dependency of Ibuprofen Gastropathy and Protective Effect of Ranitidine/An endoscopic, controlled double-blind pilot study. In a randomized parallel double-blind study, the gastric and duodenal effects of 600 mg S(+)-ibuprofen (CAS 15687-27-1) daily in the presence and absence of 300 mg ranitidine (CAS 66357-35-5) was evaluated in 20 healthy volunteers undergoing upper GI-endoscopy. Drugs were taken over a period of 7 days either at 8 a.m. (n = 10) or at 8 p.m. (n = 10). Endoscopic controls were performed at entry and repeated after 7 days of treatment. A damage score according to Lanza et al. was used. At entry both groups showed comparable mucosal damages. 8 a.m.-group: ibuprofen/placebo (stomach) 0.9 +/- 0.1 and 0.0 +/- 0.0 (duodenum); ibuprofen/ranitidine 0.8 +/- 0.1 (stomach) and 0.1 +/- 0.1 (duodenum). 8 p.m.-group: ibuprofen/placebo 0.9 +/- 0.1 (stomach) and 0.2 +/- 0.1 (duodenum); ibuprofen/ranitidine 0.9 +/- 0.1 (stomach) and 0.1 +/- 0.1 (duodenum). After 7 days of treatment the lesion score increased in the ibuprofen/placebo-group in the 8 a.m.-group to 3.2 +/- 1.2 (stomach) and to 0.7 +/- 0.5 (duodenum), and in the 8 p.m.-group to 8.4 +/- 1.9 (stomach) and to 2.9 +/- 1.2 (duodenum). The corresponding values in the ibuprofen/ranitidine-group were 1.8 +/- 0.8 (stomach) and 0.1 +/- 0.1 (duodenum) (8 a.m.-group) as well as 5.1 +/- 1.4 (stomach) and 0.1 +/- 0.1 (duodenum) (8 p.m.-group). The difference between the morning and the evening dose of ibuprofen as well as ranitidine protection reached statistical significance when the corresponding data were pooled (p < 0.05). Our data suggest that the gastrolesive effects of S(+)-ibuprofen are dependent of the time of drug ingestion; protection by ranitidine, however, was time-independent.

Adult↗
PubMed1993

[Selective reduction of multiple pregnancy in the 1st trimester: results and experience in 10 cases].

Ten patients with multiple gestations, all resulting from in vitro fertilization, underwent multifoetal pregnancy reduction. In four cases transvaginal puncture was performed, six patients underwent transabdominal pregnancy reduction. Seven women delivered, all three pregnancy losses occurred in the transvaginal punction group--there was one early loss after the procedure and two abortions in the late second trimester. There were 5 sets of twins and two singletons were delivered. Multifoetal pregnancy reduction represents an important addition to the management of unplanned multifoetal pregnancy resulting from infertility treatment. The procedure is not without risks and these must be weighted against expected benefits.

Abortion, Therapeutic↗
PubMed1993

[Cryopreservation of embryos in the in vitro fertilization/embryo transfer program].

An ultra-rapid method for cryopreservation of human embryos, using 1,2-propane-diol, was developed. 280 spare embryos obtained in the IVF program were frozen by this method. 91 embryos were thawed and 68 of them (74.7%) survived the procedure with more than half the blastomeres intact. 65 embryos were transferred in 28 cycles. Two pregnancies developed (7.1%), one of which ended by the birth of a healthy girl (the first birth after transfer of a frozen/thawed embryo in the Czech Republic). The other pregnancy is ongoing.

Cryopreservation↗
PubMed1992

Pharmacokinetics and bioavailability of spiramycin in pigs.

The pharmacokinetics of spiramycin in pigs were investigated after intravenous and oral administration. The potential therapeutically effective blood level was established after a single administration and examined in a subsidiary five day study. The rapid intravenous injection of 25 mg spiramycin/kg bodyweight produced marked salivation in all the test animals. The elimination half-life (2.3 +/- 1.2 hours) was relatively short, in accordance with the total body clearance rate (27.3 +/- 10.1 ml/minute/kg). The high volume of distribution (5.2 +/- 2.2 litres/kg) was due to the accumulation of the drug in the body tissues. The maximum plasma concentration (4.1 +/- 1.7 micrograms/ml) after oral administration of 85 to 100 mg spiramycin/kg bodyweight was reached after 3.7 +/- 0.8 hours and the half-life of the elimination phase was 6.0 +/- 2.4 hours. The oral bioavailability was 45.4 +/- 23.4 per cent. Ad libitum feeding of a diet containing 2550 mg spiramycin/kg produced a steady state concentration of 0.96 +/- 0.27 micrograms/ml. This plasma concentration would provide a potentially therapeutically effective blood concentration against Mycoplasma species, Streptococcus species and Staphylococcus species.

Administration, Oral↗
PubMed1992

The role of phospholipid asymmetry in calcium-phosphate-induced fusion of human erythrocytes.

To elucidate the role of phospholipid asymmetry in calcium-phosphate-induced fusion of human erythrocytes, we examined the interaction of erythrocyte membranes with asymmetric and symmetric bilayer distributions of phospholipids. Fusion of human erythrocytes was monitored by light microscopy as well as spectrophotometrically by the octadecylrhodamine dequenching assay. Phospholipid translocation and distribution between the inner and the outer leaflet of intact red blood cells were determined with spin-labeled phosphatidylserine (PS), phosphatidylethanolamine (PE), and phosphatidylcholine (PC). Significant fusion of lipid-asymmetric red blood cells where PS and PE are predominantly oriented to the inner leaflet was only observed at Ca2+ concentrations greater than or equal to 10 mM (in the presence of 10 mM phosphate buffer) while fusion of lipid-symmetric erythrocyte membranes was established at greater than or equal to 1.5 mM Ca2+. The Ca2+ threshold of fusion of lipid-asymmetric red blood cells was significantly reduced (i) after exposure of PS to the outer layer but not after redistribution of PE alone, and (ii) upon incorporation of spin-labeled PS into the outer leaflet of red blood cells. Spin-labeled PE or PC did not affect fusion, suggesting that the serine headgroup is an important factor in calcium-phosphate-induced fusion.

Calcimycin↗
PubMed1992

Effect of ATG prophylaxis in sensitized and non-sensitized kidney graft recipients.

In our effort to find an optimum immunosuppressive protocol for kidney transplantation we introduced two forms of ATG prophylaxis: 1. high-dose single-bolus prophylaxis (9 mg/kg) in non-sensitized patients (PRA < 5%); and 2. low-dose 8-day prophylaxis (1.5-3.0 mg/kg) in sensitized patients (PRA > 5%). A total of 204 kidney graft recipients were included in this study and treated with a triple-drug therapy (TDT). In comparison with TDT-treated controls, in sensitized patients the 8-day ATG prophylaxis resulted in a reduced rate of rejection episodes (25.5% vs 47%), an improved 1-year graft survival (82% vs 71%) and patient survival (94% vs 90%). In non-sensitized patients the high-dose single-bolus ATG prophylaxis induced a T-cell lymphopenia lasting 4 to 5 days and, in comparison with the corresponding controls, resulted in a shortened hospital stay (31.2 days vs 36.7 days), a reduced rate of rejection episodes (25.5% vs 53%), an improved 1-year graft survival (92% vs 86%) and patient survival (100% vs 94%).

Antilymphocyte Serum↗
PubMed1992

The influence of age on the pharmacokinetics of aditoprim in pigs after intravenous and oral administration.

Some pharmacokinetic parameters of aditoprim were determined in 3- and 6-month-old pigs. After intravenous administration of 5 mg/kg body weight, the mean total body clearance of the older pigs was smaller than that of the younger pigs. This difference was not reflected in the elimination half-life. After oral administration of 5 mg/kg body weight, the mean absorption rate constant was smaller and the mean absorption half-life was longer in the older pigs. The age-related changes in the pharmacokinetics of aditoprim were not sufficiently pronounced to suggest the necessity of modifying the oral dosage regimen in pigs of this age range. The favourable pharmacokinetics of aditoprim in pigs (large apparent volume of distribution, long elimination half-life and high bioavailability) may permit introduction of this drug into swine practice, after safety and residue depletion studies.

Administration, Oral↗
PubMed1992

Depressive syndromes in schizophrenic patients under neuroleptic therapy. ANI Study Group Berlin, Düsseldorf, Göttingen, Munich, Federal Republic of Germany.

Schizophrenic outpatients (= 364) were assigned at random to three different treatment strategies: (1) continuous medication with neuroleptic drugs, (2) intermittent medication with crisis intervention and (3) intermittent medication with early intervention. Depressive syndromes were rated according to three different scales for depressive syndromes (Brief Psychiatric Rating Scale anxious depression factor, Arbeitsgemeinschaft für Methodik und Dokumentation in der Psychiatrie/depression, and the self-rating Paranoid Depression Scale) after 1 and 2 years of treatment. No differences in depression scores were found between the three treatment strategies. Comparisons between patients treated with neuroleptic drugs at the time and patients without neuroleptics revealed significantly higher depression scores in the neuroleptics group in most comparisons. No differences were found between patients treated with low versus high potency neuroleptics and between oral versus depot neuroleptics. However, depression correlated with extrapyramidal symptoms.

Administration, Oral↗
PubMed1992

Inhibition of estrogen biosynthesis and its consequences on gonadotrophin secretion in the male.

Of the gonadal steroids in the male, testosterone is the most important regulator of gonadotrophin secretion. However, whether testosterone affects gonadotrophin secretion directly or whether it must first be aromatized to estrogens is controversial. We have reported extensively on the endocrine and anti-tumor effects of the non-steroidal aromatase inhibitors CGS 16949A and CGS 20267 in adult female rats. In these animals, both inhibitors potently and selectively inhibit estrogen biosynthesis. Thus these agents can be effectively used in studying estrogen-dependent processes. CGS 16949A was administered for 14 days to adult male rats, over a dose range which in females suppresses estradiol and elevates LH. In male rats a suppression of estradiol was seen, however, there was no significant effect on either serum LH or on the weights of androgen-dependent organs. CGS 16949A, when administered to healthy men at a dose of 1 mg b.i.d. for 10 days, causes a significant fall in plasma estradiol and significant elevations of plasma FSH and testosterone. Dose-dependent suppression of serum estradiol and an increase in serum testosterone and LH are seen after administration of single oral doses of CGS 20267. These results indicate that in the male rat, inhibition of aromatization of testosterone to estrogens does not influence gonadotrophin secretion whereas in men the negative feedback exerted by testosterone on gonadotrophin secretion is dependent on the aromatization of testosterone to estrogens.

Animals↗
PubMed1992

[Ultrasonic velocity measurements at weight-bearing and non-weight-bearing sites of the peripheral skeleton. The effect of physical activity in soccer players].

Ultrasound transmission velocity at the appendicular skeleton is determined by elastic properties of the bone as mass density. We evaluated ultrasound transmission velocity at the os calcis of both feet and at the proximal phalanges of DII and DIII of both hands in 51 male subjects. 28 of them were professional soccer players of the 1st German division, 11 subjects performed non-professional exercise in various athletic organisations regularly and 12 did not exercise at all. A significant difference in the speed of sound could be seen at os calcis, where the soccer players had higher velocities than the other groups. The differences between the groups at the upper and lower extremities suggest that changes in ultrasound transmission velocity are not only affected by structural changes in the aging skeleton, as it might be suggested by age differences, but by exercise. Physical exercise can change the properties (structure and/or density) of weightbearing bone and this can be detected by measuring ultrasound velocity.

Adolescent↗
PubMed1992

Evaluation of reflex cold provocation by laser Doppler flowmetry in clinically healthy subjects with a history of cold hands.

The aim of the present study was to investigate capillary blood flow and the reaction to cold provocation by means of laser Doppler flowmetry (LDF) and measurement of skin temperature at the fingertip of 39 healthy subjects who had a history of cold hands and feet but were free of any clinically significant vasospastic symptoms. A group of 39 sex- and age-matched healthy subjects without such complaints served as the control. The anamnestic complaints about cold hands and feet could be substantiated by the presence of a lower baseline skin perfusion and temperature. However, the maintenance of the normal range of reagibility to a reflex contractile stimulus with an unaltered potential to recover distinctly separates these subjects from patients with Raynaud's disease.

Adult↗