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Biomedical subjects

V Müller

Publications and source records attributed to V Müller.

At least 127 records · Page 7Linked to original sources
PubMed1991

Pharmacokinetics of ampicillin and sulbactam in patients undergoing heart surgery.

The pharmacokinetics of ampicillin and sulbactam, a new beta-lactamase inhibitor, were investigated in 16 patients undergoing prosthetic cardiac valve insertion. The combination of 2 g of ampicillin and 1 g of sulbactam was administered as perioperative prophylaxis intravenously over 3 to 6 days. Several serum pharmacokinetic parameters were similar for the two drugs after three intravenous doses were given to patients following surgery. The half-lives of elimination of ampicillin and sulbactam were 79 +/- 4.9 and 88 +/- 5.9 min, the volumes of distribution were 15.6 +/- 1.4 and 17.7 +/- 1.2 liters/70 kg, and the total plasma clearances were 144.4 +/- 14.5 and 147.2 +/- 14.5 ml/min, respectively. The peak concentrations of ampicillin and sulbactam in serum were calculated to be 134.3 +/- 1.3 and 58.3 +/- 1.2 micrograms/ml, respectively. Ampicillin and sulbactam rapidly penetrated from the blood into various tissues collected during heart surgery, such as sternum, pericardium, myocardium, and endocardium. The concentrations of ampicillin in tissue ranged from 17.8 +/- 9.9 to 50 +/- 29.5 micrograms/g, and those of sulbactam in tissue ranged from 8.8 +/- 6.2 to 19.6 +/- 10.1 micrograms/g. The concentrations of ampicillin and sulbactam in serum and tissue also apparently exceeded the MICs against most beta-lactamase-producing bacteria usually involved in postoperative wound infections and prosthetic valve endocarditis. The ratio of the two compounds was approximately 2:1 in serum and in the various tissues affected by the operation. The pharmacokinetics of ampicillin and sulbactam in serum and investigated tissues suggest that the combination of the two beta-lactams will be effective in the perioperative prophylaxis of patients undergoing heart surgery.

Aged↗
PubMed1989

[THe effect of pregnancy on the long-term course of chronic glomerulonephritis].

During a long-term study in 34 out of 154 women with bioptically ascertained glomerulonephritis 38 pregnancies were observed. The clinical manifestation took place three times during and thirteen times immediately after the end of the pregnancy. Apart from membranoproliferative glomerulonephritides all morphological forms of glomerulonephritis were present. A nephrotic syndrome was existing in 14 women (41.2%). The patients with pregnancy after on an average 11.3 years observation time showed a stabile renal function in 85.3% in contrast to 71.9% of the other female patients (not significant). The pregnancy, including a nephrotic syndrome, does not deteriorate the long-term prognosis of the glomerulonephritis.

Biopsy↗
PubMed1989

Sodium dependence of acetate formation by the acetogenic bacterium Acetobacterium woodii.

Growth of Acetobacterium woodii on fructose was stimulated by Na+; this stimulation was paralleled by a shift of the acetate-fructose ratio from 2.1 to 2.7. Growth on H2-CO2 or on methanol plus CO2 was strictly dependent on the presence of sodium ions in the medium. Acetate formation from formaldehyde plus H2-CO by resting cells required Na+, but from methanol plus H2-CO did not. This is analogous to H2-CO2 reduction to methane by Methanosarcina barkeri, which involves a sodium pump (V. Müller, C. Winner, and G. Gottschalk, Eur. J. Biochem. 178:519-525, 1988). This suggests that the reduction of methylenetetrahydrofolate to methyltetrahydrofolate is the Na+-requiring reaction. A sodium gradient (Na+ out/Na+ in = 32, delta pNa = -91 mV) was built up when resting cells of A. woodii were incubated under H2-CO2. Acetogenesis was inhibited when the delta pNa was dissipated by monensin.

Acetates↗
PubMed1989

[Differentiation of hematuria by phase contrast microscopy studies of urine erythrocytes].

The results of phase-contrast microscopic investigations of urinary erythrocytes in 300 patients (120 patients with bioptical verified glomerulonephritis, 54 patients suffering from interstitial nephritis, 56 patients with urinary tract diseases and 70 healthy probands) are discussed. The portion of glomerular erythrocytes is dependent on diuresis, renal function and activity of glomerulonephritis. This non-invasive procedure is quick and easy practicable and its results are reliable (sensitivity and specifity of more than 90%). The proof of mainly glomerular erythrocytes save from instrumental and invasive diagnostic procedures in nephrological diseases, whereas non-glomerular erythrocytes may have an urological or hematological origin.

Adolescent↗
PubMed1988

Electron-transport-driven sodium extrusion during methanogenesis from formaldehyde and molecular hydrogen by Methanosarcina barkeri.

Methanogenesis from formaldehyde or formaldehyde + H2, as carried out by Methanosarcina barkeri, was strictly dependent on sodium ions whereas methane formation from methanol + H2 or methanol + formaldehyde was Na+-independent. This indicates that the reduction of formaldehyde to the formal redox level of methanol exhibits a Na+ requirement. During methanogenesis from formaldehyde, a delta pNa in the range of -62 mV to -80 mV was generated by means of a primary, electron-transport-driven sodium pump. This could be concluded from the following results obtained on cell suspensions of M. barkeri. 1. The addition of proton conductors or inhibitors of the Na+/H+ antiporter had no effect on sodium extrusion. 2. During methanogenesis from formaldehyde + H2 a delta psi of -60 mV to -70 mV was generated even in the presence of proton conductors. 3. ATPase inhibitors, applied in the presence of proton conductors, had no effect on primary sodium extrusion or generation of a delta psi. Evidence for a Na+-translocating ATPase could not be obtained.

Adenosine Triphosphate↗
PubMed1988

The transmembrane electrochemical gradient of Na+ as driving force for methanol oxidation in Methanosarcina barkeri.

A sodium ion gradient (inside low) across the cytoplasmic membrane of Methanosarcina barkeri was required for methanogenesis from methanol. This could be concluded from the following results. (a) Inhibition of the Na+/H+ antiporter by K+ or amiloride led to an inhibition of methanogenesis from methanol. (b) Upon addition of the sodium ionophore monensin the Na+ gradient was abolished and at the same time methanogenesis from methanol was inhibited. (c) Methanogenesis was impaired when the Na+ gradient had the opposite orientation (inside high). All these inhibitory effects were not observed when H2 was present in addition to methanol indicating that the oxidation of methanol to CO2 was driven by a sodium-motive force. In accordance with this, a methanol-dependent influx of Na+ and a corresponding decrease of the membrane potential could be observed, when the Na+/H+ antiporter was inhibited by amiloride. This influx was indicative of the presence of a Na+ transport system which was functional when the oxidation of methanol had to be driven, but was not functional when H2 was present for reduction of methanol to methane.

Amiloride↗
PubMed1988

[Hair disease or the effect of heat (fire)?].

We found alterations in the ends of a man's hair, changes that were suspected of being incendiary. The hair ends were dull, but there were no typical macroscopic signs of alteration by heat; yet the microscopic findings were clear. Spindle-shaped changes in the hair were interpreted at first as heat damage but could be explained as the results of hair-setting lotion.

Diagnosis, Differential↗
PubMed1988

Bioenergetics of methanogenesis from acetate by Methanosarcina barkeri.

Methane formation from acetate by resting cells of Methanosarcina barkeri was accompanied by an increase in the intracellular ATP content from 0.9 to 4.0 nmol/mg of protein. Correspondingly, the proton motive force increased to a steady-state level of -120 mV. The transmembrane pH gradient however, was reversed under these conditions and amounted to +20 mV. The addition of the protonophore 3,5,3',4'-tetrachlorosalicylanilide led to a drastic decrease in the proton motive force and in the intracellular ATP content and to an inhibition of methane formation. The ATPase inhibitor N,N'-dicyclohexylcarbodiimide stopped methanogenesis, and the intracellular ATP content decreased. The proton motive force decreased also under these conditions, indicating that the proton motive force could not be generated from acetate without ATP. The overall process of methane formation from acetate was dependent on the presence of sodium ions; upon addition of acetate to cell suspensions of M. barkeri, a transmembrane Na+ gradient in the range of 4:1 (Na+ out/Na+ in) was established. Possible sites of involvement of the Na+ gradient in the conversion of acetate to methane and carbon dioxide are discussed. Na+ is not involved in the CO dehydrogenase reaction.

Acetates↗
PubMed1988

[Glomerulonephritis in sarcoidosis].

The renal involvement in sarcoidosis can be demonstrated as nephrocalcinosis, nephrolithiasis, granulomatous nephritis, and glomerulonephritis. The clinical signs of a renal manifestation are inferior than the morphological findings, so that the reported frequency of 9-25% is an approximate value. In the literature the glomerular changes are rare. In the case of glomerulonephritis the membranous form is dominating; an extracapillar-proliferative glomerulonephritis is described in only 3 cases in the literature. The course of a 16-year-old male patient with an extracapillar-proliferative glomerulonephritis and M. Boeck is described in detail. After a prednisolone therapy for 2 years, which was introduced by methylprednisolone at 1000 mg for 3 days, the renal function was improved continuously.

Adolescent↗
PubMed1987

Generation of a transmembrane gradient of Na+ in Methanosarcina barkeri.

A transmembrane Na+ gradient was generated by Methanosarcina barkeri during methanogenesis. The intracellular Na+ concentration amounted to approximately one fifth of the extracellular one. A secondary Na+/H+ antiport system was shown to be responsible for Na+ extrusion. This system could be inhibited by amiloride. In the presence of amiloride the delta pH across the cytoplasmic membrane increased and a transmembrane Na+ gradient could neither be generated nor maintained. The possible role of Na+ in the oxidation of methanol to the level of formaldehyde is discussed.

Amiloride↗
PubMed1987

[Macro- and microscopic findings of cord marks in 2 cases of delayed death by hanging].

Two cases of delayed death after suicidal or accidental hanging are reported. Despite equally long survival times (33 and 27 days, respectively) and macroscopically very similar cord furrows, segmental granulation tissue was present histologically in one case (suicide) below the cord furrow, and in the other case there was a normal corium. The main cause for the divergent ultrastructural findings consists in the variable degree of strangulation.

Accidents, Home↗