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A Müller

Publications and source records attributed to A Müller.

At least 469 records · Page 26Linked to original sources
PubMed1990

Improved method for estimating Ca uptake in vascular smooth muscle using compartmental analysis.

A comparative study on the modeling aspects of Ca uptake in vascular smooth muscle is presented with particular emphasis on determination of the influx rate and its standard error for one- and two-compartment models. Experimental data from our laboratory of 45Ca uptake by dog carotid arteries were optimally fitted to a one-compartment model and were used to compare different estimation methods and experiment designs. Reparameterization of the model equation yielded an expression that allows direct estimation of the influx rate and its standard error. Experiment design with replicated sampling at three to four times were found to provide the highest estimation precision and successful comparisons of influx rates under treatment and control conditions. Two-compartment model data reported in the literature for Ca uptake by cells were reprocessed, yielding standard errors for the rate constant of the fast component an order of magnitude larger than the mean estimate. For this case, a three-parameter variant of the one-compartment model was developed that described the data with acceptable standard errors. Overall we found that the choice of the model that fitted Ca uptake data best required consideration of parameter estimate precision comparisons in addition to F tests of significance between alternate models.

Animals↗
PubMed1990

[Emergency and early portasystemic shunt: indications and results].

The definitive hemostasis is the key to successful therapy of variceal bleeding. There is a difference between the emergency operation for persistent bleeding in spite of initial sclerosing therapy and the planned early operation for primary massive bleeding, early recurrence of bleeding and bleeding of fundus varicosis. The lethality is about 50% for the emergency operation, about 12% for the early operation (Berlin). For the emergency situation the portacaval end-to-side anastomosis is favoured. The result of this therapeutical concept in Bonn (1989-1990) for 47 patients admitted for bleeding was a hospital lethality of 23%.

Aged↗
PubMed1990

Influence of membranes on generation of beta 2 M and release of leukocyte lysosomal enzymes.

Normal leukocyte functional capacity was investigated by evaluation of phagocytosis of opsonised yeast cells in a radiometric test system. After incubation with dialysis membranes (different cellulosic membranes, polysulfon membrane (PS), polymethylmetacrylate membrane (PMMN), the phagocytosis index, expressed as percent decrease with respect to initial values without membrane, decreased by 10%-25%. The most pronounced effect was observed with PS, cuprophane, modified cellulose and PMMA. The results are not related to differences in the viability of PMN during the test procedure; dead PMN amounted to about 4-6.5%. A significant increase in beta-NAG and beta-Gluc activities was released in the supernatants of the phagocytosis suspensions. This increase activity can be explained by the phagocytosis of PMN but it was not influenced by membrane contact. There was no influence of membrane contact or phagocytosis activity of PMN on the beta 2 M concentration in the supernatant demonstrating that no in vitro generation during incubation with either membrane exists.

Acetylglucosaminidase↗
PubMed1990

[Hydroxyproline excretion in psoriasis and psoriatic arthritis].

In the morning urine of 24 patients with psoriasis and that of 24 patients with psoriatic arthritis, we determined the excretion of hydroxyproline (mg HP/mumol crea), after preceding diet low in collagen. Surprisingly, psoriatic patients without articular involvement showed a significantly higher excretion of HP than those with psoriatic arthritis. Further differentiation revealed that there were no clear-cut correlations between the amount of HP excretion and the activity of the articular process; we proved, however, that the amount of HP excretion was definitely related to the activity of the skin eruptions in both groups of patients. We discuss whether an osteopathy pathogenetically associated with the skin disease (irrespective of synovitis in psoriatic arthritis) may possibly be responsible for these results.

Adult↗
PubMed1990

[Legal requirement of medical-psychological examination of drunk driving offenders: should other than blood alcohol concentration and "particular circumstances" of the individual case be considered?].

According to a footnote of the directions for driver selection tests ("Eignungsrichtlinien") of December 1, 1982, a medical and psychological examination can be disposed also with first drunkenness offenders. Against the design, partially realised in practice, to use not only the blood alcohol level as a screening criterion but also special circumstances of the case, objections are brought forward.

Accidents, Traffic↗
PubMed1989

[Psoriatic osteopathy].

In order to make evident an up to now only postulated generalized osteopathy in psoriatics in 24 patients with psoriasis and 24 patients with psoriatic arthritis the serum-calcium levels, the alkaline phosphatase in the serum and the excretion of hydroxyprolin in the urine were determined. Moreover, the bone bioptates of 25 patients with psoriatic arthritis and 10 patients with psoriasis were histologically examined and morphometrically measured, respectively. The examinations give evidence for the presence of a generalized "latent" osteopathy in the sense of an increased bone turnover rate without loss of bone volume (high turnover remodeling) in patients with psoriatic arthritis as well as in those with psoriasis without arthritis. As a common pathogenetically significant factor for dermatosis and osteopathy a latent vitamin D deficiency and a D-hormone resistance is discussed.

Alkaline Phosphatase↗
PubMed1989

[Microalbuminuria screening in diabetics].

Nocturnal albumin excretion rate was measured in 133 diabetics and the results were compared with those in first morning urine and urine spontaneously voided later in the morning. Albumin concentrations greater than 20 mg/l in the first morning urine indicated a raised albumin excretion rate of 20-200 micrograms/min (sensitivity 86%, specificity 98%). Simultaneous creatinine measurement and calculation of the albumin/creatinine ratio did not increase sensitivity or specificity. An albumin concentration greater than 20 mg/l in spontaneously voided day urine pointed to a raised albumin excretion rate (sensitivity 90%, specificity 60%). These results suggest that determining the albumin concentration in the first voided morning urine is suitable as screening test for microalbuminuria.

Adult↗
PubMed1989

A novel L-glutamate oxidase from Streptomyces endus. Purification and properties.

A new flavoenzyme using molecular oxygen to oxidize L-glutamic acid has been purified to homogeneity, as judged by polyacrylamide gel electrophoresis, from the culture medium of Streptomyces endus. Hydrogen peroxide, 2-oxoglutaric acid and ammonia are formed as products. Among 25 amino acids tested including D-glutamic acid, L-glutamine and L-aspartic acid, only L-glutamic acid is converted. The molecular mass of the enzyme was estimated to be about 90 kDa by gel chromatography and 50 kDa by SDS/PAGE. The subunit contains 1 molecule noncovalently bound FAD. The absorption spectrum shows maxima at 273, 355 and 457 nm and the isoelectric point is at pH 6.2. The Km value for L-glutamic acid in air-saturated phosphate pH 7.0 was estimated to be 1.1 mM, the Km for oxygen was calculated to be 1.86 mM at saturating concentration of L-glutamic acid. The enzymic reaction is inhibited by Ag+ and Hg2+ ions. The enzyme described here distinctly differs from two microbial L-glutamate oxidases purified hitherto, with regard to extremely high substrate specificity and to the subunit structure.

Amino Acid Oxidoreductases↗
PubMed1989

[The familial carcinoma burden and indications for subcutaneous mastectomy].

Histological examination of the surgical specimen was undertaken in 182 women (aged between 20 and 58 years, mean 44 years) after a subcutaneous mastectomy, which had been performed largely because the diagnosis of the breast lesion had been problematic. Among 46 patients, operated on exclusively because of either palpatory or radiological diagnostic problems, histological examination revealed occult carcinoma or precancerous lesion in two, while among 58 patients with combined palpatory and radiological diagnostic problems there were twelve with invasive or noninvasive carcinoma, and among seven with at least four preoperative biopsies there was none. Four of 41 patients who had previously had a modified radical mastectomy of the other breast for invasive breast cancer had invasive or noninvasive carcinoma, as well as 18 of 30 patients with biopsy-confirmed proliferative breast lesion. There was a statistically significant correlation between the incidence of occult carcinoma and familial incidence. The results indicate that subcutaneous mastectomy is justified in case of diagnostic problems only if (1) in the presence of an increased genetic risk neither palpatory nor radiological diagnosis is clearcut, (2) there is known contralateral carcinoma, or (3) preoperative examination demonstrates proliferative lesions with atypical epithelium.

Adult↗
PubMed1989

The membrane-bound hydrogenase from Paracoccus denitrificans. Purification and molecular characterization.

The membrane-bound hydrogenase from Paracoccus denitrificans was purified 68-fold with a yield of 14.6%. The final preparation had a specific activity of 161.9 mumol H2 min-1 (mg protein)-1 (methylene blue reduction). Purification involved solubilization by Triton X-114, phase separation, chromatography on DEAE-Sephacel, ammonium-sulfate precipitation and chromatography on Procion-red HE-3B-Sepharose. Gel electrophoresis under denaturing conditions revealed two non-identical subunits with molecular masses of 64 kDa and 34 kDa. The molecular mass of the native enzyme was 100 kDa, as estimated by FPLC gel filtration in the presence of Chaps, a zwitterionic detergent. The isoelectric point of the Paracoccus hydrogenase was 4.3. Metal analysis of the purified enzyme indicated a content of 0.6 nickel and 7.3 iron atoms/molecule. ESR spectra of the reduced enzyme exhibited a close similarity to the membrane-bound hydrogenase from Alcaligenes eutrophus H16 with g values of 1.86, 1.92 and 1.98. The half-life for inactivation under air at 20 degrees C was 8 h. The Paracoccus hydrogenase reduced several electron acceptors, namely methylene blue, benzyl viologen, methyl viologen, menadione, cytochrome c, FMN, 2,6-dichloroindophenol, ferricyanide and phenazine methosulfate. The highest activity was measured with methylene blue (V = 161.9 U/mg; Km = 0.04 mM), whereas benzyl and methyl viologen were reduced at distinctly lower rates (16.5 U/mg and 12.1 U/mg, respectively). The native hydrogenase from P. denitrificans cross-reacted with purified antibodies raised against the membrane-bound hydrogenase from A. eutrophus H16. The corresponding subunits from both enzymes also showed immunological relationship. All reactions were of partial identity.

Alcaligenes↗
PubMed1989

DNA index and cell cycle analysis of primary breast cancer and synchronous axillary lymph node metastases.

The DNA Index (DI) and the percentage of cells in S-phase (S-phase fraction, SPF) were measured by flow cytometry in 80 primary breast carcinomas and in 80 accompanying axillary lymph node metastases. The DI in primary tumors and metastases agreed in 61 cases (76%). Cases with diploid primary tumors revealed more constancy of the DI in comparison to the metastases than the cases with aneuploid primary tumors (91% and 70% respectively). The mean values of the SPF were in close agreement in the primary tumors and in the lymph node metastases (6.1% and 6.0% respectively). Differences between the SPF of the two groups could be detected only by the consideration of case-related data pairs. In 50 cases (62%), the percentage of SPF agreed approximately in primary tumors and in the correspondent metastases. The cases with diploid primary tumors revealed more agreement of the SPF in the primary site and the metastases than did cases with aneuploid primary tumors (78% and 56% respectively). In conclusion, diploid carcinomas and their metastases revealed more constancy of the DI and the percentage of SPF than aneuploid carcinomas. These findings agree well with a better prognosis of diploid mammary carcinomas, as reported in the literature. Comparisons between the DI and the SPF in primary tumors and the corresponding metastases could be a source of valuable information on the biological behaviour and the aggressiveness of mammary carcinomas.

Aneuploidy↗
PubMed1989

The potential of epicardial activation mapping in isolated hearts for the assessment of arrhythmogenic and antiarrhythmic drug activity.

In isolated rabbit hearts perfused according to the Langendorff technique, the pathway and time course of the epicardial activation process were studied by means of computer-assisted epicardial potential mapping, using a matrix of 256 unipolar AgCl electrodes (1 mm spatial and 0.25 msec temporal resolution). Activation time of each electrode was calculated (point of time of fastest negative intrinsic deflection). From the activation times of the surrounding electrodes, the direction and velocity of activation for each electrode were calculated, thereby allowing construction of an epicardial vector field. Furthermore, breakthrough points (BTPs) were determined as the earliest activated electrodes in a given region. Vector-field orientation and BTP localization were compared under different conditions during perfusion with Tyrode's solution or during drug treatment. Thereby, we determined the similarity of the vector fields (two vectors were considered to be identical if not differing by more than 5 degrees) and the percentage of BTPs with changed localization, referred to the total number of BTPs. For verification of the method we treated the hearts with ouabain (0.2 mumol/l) and observed progressive decline in vector-field similarity from 32% down to 14%, resulting in arrhythmia. Concomitantly, the percentage of BTPs with identical localization decreased from 81% to 50%. These changes could be reversed by additive treatment with 10 nmol/1 verapamil. From these results we conclude that arrhythmia is preceded by a state of deteriorated epicardial activation pattern (prearrhythmia), which can be quantitatively evaluated and used for detection of preventive antiarrhythmic drug action.

Animals↗
PubMed1989

[Side effects and complications in breast-saving therapy of breast cancer].

From 1975 to June 1987, a total of 664 women underwent breast-conserving therapy for invasive carcinoma at the University Hospital for Women, Heidelberg, FRG (562 patients: surgical procedure/radiotherapy, 102 patients: only radiotherapy). A subgroup of 203 nonselected patients was prospectively followed up for complications and side effects. The population examined was representative of the entire series with reference to age distribution, tumor stage and localisation. The mean follow-up period was 28.9 months after primary therapy. Complications of breast-conserving therapy (surgery, post-operative radiotherapy, adjuvant chemotherapy for node-positive patients) were assessed by one investigator including evaluation of a standardized patients' questionnaire. The most frequent and serious single complication was lymphedema (LE) of the arm. The incidence of severe LE (greater than or equal to 3 cm difference in circumference) was 6.4%. A total of 25.1% of all patients reported some degree of swelling of the arm. The overall LE-rate was 23.1% according to the newly introduced LE-score combining the degree of difference in circumference, individual handicap and need for physiotherapy. The LE-rate was significantly increased in patients with adjuvant chemotherapy (40.1%, p less than 0.01). General impairment of arm function was reported frequently (65.6%). Shoulder mobility was severely restricted (abduction of arm less than or equal to 90 degrees) in 3.6%. Further complaints were related to impairment of fine motor function (4.5%), shielding of the arm (15.4%), reduction in absolute force (22.1%) and/or rapid tiring of the arm (37.4%). Radiotherapy related toxicity accounted for cutaneous edema (50.3%) and fibrosis of the breast (slight: 33.8%, pronounced: 9.7%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗