Biomedical subjects

M Bolten

Publications and source records attributed to M Bolten.

4 recordsLinked to original sources

PubMed2005

[Cryopreserved human sperm deposits: usability after decades of storage].

To determine the effect of long-term storage on cryopreserved human sperm, 238 individual samples from 34 cryopreserved sperm deposits that had been collected between 1976 and 1989 were evaluated at regular intervals. The material was from 34 patients, 18 of whom suffered from underlying malignant disease. Every 3 years a sample from each deposit was thawed for microscopic analysis. During the course of the storage period limited to a maximum of 21 years, all ejaculate parameters had deteriorated in comparison to fresh semen. Quantitative motility was the most sensitive parameter with a decrease of ca. 80%. Sperm density decreased hardly at all. The parameters of the criteria investigated did not decrease linearly or proportionally with the storage duration, but rather more directly after the freezing process or within the first 3 years. These changes became increasingly smaller as the storage time lengthened. Almost all of the deposits exhibited adequate quality at all times during storage. Consequently, 21-year permanent frozen storage in liquid nitrogen is safe regarding aspects of spermatology.

Cryopreservation↗

PubMed2004

[Retrocaval ureter].

A 13-year-old boy presented to our clinic with a newly found hydronephrosis, which was caused by a retrocaval ureter. Besides this we noticed a glandular hypospadia. After we made sure that the right kidney had a normal function in the ING, we removed the stenosed ureter segment and performed an end-to-end anastomosis. The DJ stent was removed without any complications 5 weeks after the operation.

Adolescent↗

PubMed1999

Structural analysis of G-DNA in solution: A combination of polarized and depolarized dynamic light scattering with hydrodynamic model calculations.

Specific intra- and intermolecular quadruplex conformations of model G-DNA oligonucleotides have been identified from their translational and rotational diffusion coefficients in aqueous solution. The transport properties were determined by polarized and depolarized dynamic light scattering. A comparison with hydrodynamic model calculations provides detailed information about the size and shape of the molecules and allows one to distinguish between alternative intra- and intermolecular association. The potential of this combination of methods to elucidate biomolecular structures in solution, to characterize conformational changes, and follow intermolecular interaction processes due to a response to external stimuli has been discussed.

DNA↗

PubMed1991

Effect of chronic theophylline administration on amphotericin B nephrotoxicity in rats.

The effect of chronic theophylline administration on amphotericin B nephrotoxicity was investigated in rats. A 7-day treatment of amphotericin B (5 mg/kg/day i.p.) significantly reduced the glomerular filtration rate (GFR) measured as inuline clearance and creatinine clearance (0.74 +/- 0.29 and 0.16 +/- 0.04 ml/min, respectively) in comparison to vehicle-treated rats (2.04 +/- 0.23 and 1.29 +/- 0.19 ml/min, respectively). The reduced GFR led to evaluations in serum creatinine and BUN concentrations (0.94 +/- 0.09 and 78 +/- 11 mg/dl) in comparison to their own values before treatment (0.45 +/- 0.11 and 19 +/- 3 mg/dl). In addition amphotericin B induced an increase in sodium and a decrease in potassium excretion, the fractional sodium excretion was elevated 50-fold. The methylxanthine, theophylline, had a beneficial effect on the outcome of amphotericin-B-induced renal failure. The inuline clearance was 1.17 +/- 0.04 ml/min, the creatinine clearance 0.43 +/- 0.03 ml/min, the serum creatinine concentration 0.76 +/- 0.05 mg/dl and the BUN concentration 40 +/- 6 mg/dl. Theophylline had no effect on total sodium excretion and potassium excretion. The fractional sodium excretion, however, improved significantly. Theophylline as well as sodium deoxycholate, the detergent of amphotericin B, given alone had no effect on renal hemodynamics measured after 7 days.

Acute Kidney Injury↗