Repair and mutagenesis of plasmid DNA modified by ultraviolet irradiation or N-acetoxy-N-2-acetylaminofluorene.

Plasmid DNA was modified in vitro to various extents with N-acetoxy-N-2-acetylaminofluorene or UV irradiation. The modified plasmid DNAs were then used to transform Escherichia coli strains having different repair capabilities. Both survival and mutagenesis frequencies of the plasmid were measured as a function of the number of lesions per plasmid molecule. The majority of N-2-acetylaminofluorene (AAF) adducts, like thymine dimers, were repaired by the excision (uvrA+-dependent) pathway. In rec+ strains, dose-dependent mutagenesis occurred in either AAF- or UV-modified plasmid DNA. This is in contrast with results obtained in recA- strains, in which only AAF adducts gave rise to a lower, but dose-dependent, mutagenesis frequency. In these recA- strains there was no UV mutagenesis. Unlike what is observed with phages, induction of the "SOS" functions by UV irradiation of the bacteria prior to transformation did not increase the survival or the mutagenesis of the plasmid.     

Mikrochirurgie lumbaler Bandscheibenvorfälle Üerlegene Ergebnisse der Mikrochirurgie im Vergleich zu Standard- und perkutanen Verfahren (Literaturübersicht)

In a meta-analysis of 69 prospective and retrospective studies, we investigated the value of various surgical techniques in the treatment of lumbar disk herniations. This analysis includes standard diskectomy (5080 patients from nine series), microdiskectomy (5354/23), and comparison of both techniques (2494/10) and furthermore chemonucleolysis (2729/16), laser therapy (881/3), percutaneous nucleotomy (3506/18), comparisons of percutaneous techniques (942/5) with microdiskectomies (561/5) and standard diskectomies (1020/6). Outcomes were rated according to Macnab's criteria: I "excellent", II "good", III "improved", IV "same as before", V "worse", I/II "markedly improved", III "partially improved", IV/V "not improved", I-III "successful", and IV/V "unsuccessful". Results after microdiskectomy were "successful" more often (90% vs. 95%), "good/excellent" more often (82% vs. 73%), and patients left the hospital sooner than with standard diskectomy. Recurrence rates were comparable (4%). Results of both open techniques were clearly superior to those from any type of percutaneous treatment: chemonucleolysis und laser therapy were "successful" in 69% and 70% of cases respectively, with recurrence rates of 17% and 18%, endoscopic nucleotomy was "successful" in 84% of cases, and recurrence rate was 14%. Please ask the author for the reference database.     

Endourologische Operationstechniken bei interstitieller Zystitis

Endourological surgical procedures (transurethral resection and fulguration, Nd-YAG-laser application) for the treatment of interstitial cystitis (IC) have been evaluated only in a few studies. Theoretically, they could be the next step in a therapeutic concept after conservative measures have failed and before open surgery is performed as an ultima ratio. However, our review of the literature suggests that to date there is no scientific evidence to support endourological techniques in the treatment of IC.     

Sildenafil in the treatment of sexual dysfunction in spinal cord-injured male patients

OBJECTIVES: The aim of this study was to evaluate the efficacy and safety of sildenafil in the treatment of erectile dysfunction (ED) in spinal cord-injury (SCI) patients. Moreover, we looked for neurological conditions permitting therapeutic success and for the ideal dose needed to achieve sufficient erections. METHODS: 41 SCI patients were prospectively examined. Sexual dysfunction was assessed by means of anamnesis, the International Index of Erectile Function (IIEF) questionnaire, and neurological examination. Psychogenic erection capacity was tested by audiovisual stimulation and reflexive erection using a vibrator device. Neurophysiological recordings and cystomanometry were performed in parallel to clinical examinations. Neurophysiological recordings included sympathetic skin responses (SSR), pudendus somatosensory evoked potentials (pSSEP), and bulbocavernous reflex (BCR). Urodynamics aimed at classifying the neurogenic bladder dysfunction (upper motoneuron lesion versus lower motoneuron lesion). Intracavernous injection tests with PGE1 were performed in all patients to exclude major organic disease. 50 mg sildenafil was first given 3 times. Thereafter, the doses were adapted according to patients' reports. RESULTS: Clinically, 28 subjects preserved either reflexive erections (24) or psychogenic erections (4), 11 had both types and only 2 presented with a complete loss of erection. 38 patients (93%) had a positive response to sildenafil and reached a penile rigidity sufficient to permit sexual intercourse. 3 patients dropped out because of non-response despite having increased the dosis up to 100 mg. 22 patients (58%) showed functional erections 1 h after 50 mg sildenafil, whereas 14 (37%) required higher doses of 75-100 mg. By comparing the IIEF questionnaire scores before and after therapy, there was a significant improvement in erectile function and intercourse satisfaction from 9.2+/-4.4 SD) and 4.5 (+/-2.5 SD) to 25.5 (+/-4.2 SD) and 10.5 (+/-2.1 SD) points, respectively (p<0.05). Nearly 10% (4/41) suffered from side effects such as headache or dizziness. Two of them stopped therapy because of the side effects. At least 36 patients (88%) continue treatment with sildenafil. Absence of both psychogenic (nonsomesthetic supraspinally elicited) and reflexive (somesthetic spinally elicited) erections, confirmed by urodynamical and electrophysiological findings (SSR perineum, BCR and pSSEP), seems to exclude a successful treatment. In contrast, SCI male patients with preserved function of at least one component of the erection phenomenon (psychogenic/reflexive) responded well to sildenafil and the dose required to achieve erections sufficient for sexual intercourse did not differ between the two groups. CONCLUSIONS: Sildenafil proves to be a valuable and safe therapeutic management in ED of SCI patients. Therefore, patient acceptance and satisfaction are high. The most common dose required to achieve a satisfying erection is 50 mg. The efficacy of sildenafil depends on sparing of either sacral (S2-S4) or thoracolumbar (T10-L2) spinal segments which, in this study, have been shown to be of relevance in mediating psychogenic erections in male SCI patients. Complete disturbance of any neurogenic impulses excludes successful treatment.     

Vom Antigen zum Tumormarker Forschungsergebnisse zu PSA und ihre klinische Umsetzung

The determination of prostate-specific antigen is credited with dramatic advances in the early detection of men with prostatic carcinoma. This report summarizes the history of biochemical research and current status of prostate-specific antigen in tumor diagnostics.     

Five meters of H(2)O: the pressure at the urinary bladder neck during human ejaculation

BACKGROUND: There are no data in the literature on pressure changes in the prostatic urethra during ejaculation. In healthy men, it has always been postulated that there must be a pressure gradient in order to prevent retrograde ejaculation, but scientific proof for that is pending. METHODS: In five healthy male volunteers, the pressure profile in the prostatic urethra was registered during ejaculation, using a 10 French balloon catheter with 16 pressure channels. The channels were arranged in pairs at 5-mm intervals, beginning just below the balloon at the bladder neck and extending down to the external urethral sphincter. RESULTS: In the proximal part of the prostatic urethra, a pressure of up to 500 cm of H(2)O was measured in all subjects. Contrary to that, pressures did not exceed 400 cm of H(2)O distally to the verumontanum. CONCLUSIONS: A novel method to register the pressure profile in the lower urinary tract during ejaculation (ejaculomanometry) is presented. This study adds to the knowledge of the normal physiology of reproductive function and may be useful in the evaluation of male sexual and reproductive disorders.     

Effects of Nicotine on Bone and Calciotropic Hormones in Growing Female Rats

Limited research in young adults and immature animals suggests a detrimental effect of tobacco on bone during growth. This study investigated the effects of nicotine, the major alkaloid component of tobacco, on calciotropic hormone concentrations and bone status in growing female rats. One-month-old animals received either saline (n = 10), nicotine at 3.0 mg/kg/day (n = 10), or nicotine at 4.5 mg/kg/day (n = 10) administered subcutaneously via osmotic minipumps for either 2 or 3 months. Sera, femora, tibiae, and lumbar vertebrae (3–5) were collected at necropsy. The concentrations of serum calcium, phosphorus, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, parathyroid hormone, calcitonin, and insulin-like growth factor-I were determined. Bone variables evaluated included mineral content and density (vertebrae and femora), cancellous and cortical histomorphometry (tibiae), and bone strength (vertebrae and femora). Statistically significant differences in serum mineral and hormone concentrations were not associated with nicotine dose or exposure time. No significant nicotine treatment effects were detected for bone mineral content and density, bone histomorphometry, or bone strength. We conclude that nicotine treatment for 2 or 3 months at serum concentrations in the upper range of those found in smokers has no detrimental effect on bone mass, volume, or strength in the growing rat. Received: 20 May 1999 / Accepted: 21 January 2000     

Pure primary choriocarcinoma of the urinary bladder with long-term survival

Choriocarcinoma was diagnosed in a 77-year-old woman with an acute massive, painless hematuria. One year after anterior pelvic exenteration and ileal conduit, the beta-human chorionic gonadotropin level increased to 934 mIU/mL without any sign of tumor progression. After six courses of chemotherapy (vincristine, actinomycin, and cyclophosphamide), the beta-human chorionic gonadotropin levels returned to normal. To our knowledge, this is the fourth case of pure choriocarcinoma in the bladder, with the longest survival time of 33 months so far.     

Die kongenitale Tibiapseudarthrose

Congenital pseudarthrosis of the tibia (CPT) is one of the most challenging conditions in paediatric orthopaedics. The history of CPT treatment is characterised by repeatedly ineffective surgical interventions with the inevitable outcome of severe disability. Most procedures failed to account for the complexity of the problem. The past two decades have witnessed more experience having been gained with the Ilizarov technique. This method provides a comprehensive approach to all aspects of CPT problem, allowing the surgeon to simultaneously address the problems of union as well as those of deformity, length discrepancy joint function, ankle valgus and weight bearing. It appears that the goal to achieve stable fusion before the child begins school is attainable. In the pre-pseudoarthrotic stage, bracing should be preferred to surgery until the patient is in an older age group. This study reports on the results of 19 patients: 15 have finished treatment, and 14 of them with a stable fusion at follow-up. The results were highly encouraging in reaching the ultimate goal of avoiding amputation and achieving a well-functioning limb.     

Mineralocorticoid receptor knockout mice: lessons on Na+ metabolism

The mineralocorticoid receptor (MR) binds aldosterone and glucocorticoids with equal affinity. In aldosterone target tissues, like the epithelial cells of the distal colon and the principal cells of the collecting ducts in the kidney, the MR is protected from glucocorticoids by the action of the enzyme 11beta-hydroxysteroid-dehydrogenase type 2 (11betaOHSD2), allowing aldosterone to specifically activate the receptor. However, in MR-expressing cells, which lack 11betaOHSD2, like the neurons of the limbic system in the brain, MR is mainly activated by glucocorticoids. MR knockout mice die in the second week after birth, showing at day 8 symptoms of pseudohypoaldosteronism with hyponatremia, hyperkalemia, high renal salt wasting, and a strongly activated renin-angiotensin-aldosterone system (RAAS). The activity of the amiloride-sensitive epithelial Na+ channel (ENaC) is strongly reduced in colon and kidney, but there is no down-regulation of the mRNA abundance of the three ENaC subunits. Daily subcutaneous injections of isotonic NaCl solution until weaning and continued oral NaCl supply lead to survival of the MR knockout mice. The NaCl-rescued MR knockout mice display a strongly enhanced fractional renal excretion of Na+, hyperkalemia, and a persistently strongly activated RAAS. There is almost no renal ENaC activity. The renal mRNA abundance of alphaENaC is reduced by 30%, whereas betaENaC and gammaENaC are not altered.