Search PubMed⌕ Search

Biomedical subjects

L Hertle

Publications and source records attributed to L Hertle.

At least 91 records · Page 5Linked to original sources
PubMed1994

[Diagnosis of urethral diverticulum in women].

Urethral diverticula have proved to be a common cause of recurrent urinary tract infections in female subjects. Positive-pressure urethrography, mostly performed by means of double-balloon catheters, has hitherto been regarded as the method of choice for their detection. Unfortunately, the few existing commercial catheter devices have certain disadvantages, which have led to a lack of acceptance of this important technique and restricted its use. We therefore present an improved tool for positive-pressure urethrography and a synopsis of diagnostic visualization procedures for urethral diverticula in women.

Diverticulum↗
PubMed1993

Bladder substitutes, bile acids and the risk of colorectal cancer: an experimental study.

There is a large body of evidence relating the causation of colon cancer to bile acids. Using an animal model, we attempted to address the question, i.e., the incidences of carcinogenesis in the colon as consequences of resection of different bowel segments, predominantly employed in the construction of various forms of intestinal bladder substitutes. 60 male Wistar rats were operated. Group 1 served as control, in group 2, 20 cm of terminal ileum was resected, and rats in group 3 underwent resection of the distal 10 cm of the ileum and 7 cm of the proximal colon. All rats were killed 6 months after surgery and the colon was removed. After examination under 40-fold magnification, in the absence of tumors, 3 biopsies were performed at predetermined positions and underwent histological processing. Even if no tumor was found it would be incorrect to conclude that these results would have an appeasing relevance. The complex and highly different fecal bile acid profiles of the rat compared to man makes it impossible in this context to draw analogies between the rat model and human colonic carcinogenesis. Furthermore, 6 months of observation in the rat might be too short for 'spontaneous' colonic carcinogenesis. Nevertheless, there exists evidence from epidemiological studies to implicate bile acids as an etiological factor in the development and growth of colorectal cancer. Therefore, the importance of colorectal cancer in urologic surgery patients must be kept in perspective. In this direction, further studies are required besides the application of known appropriate preventive measures.

Animals↗
PubMed1992

Composition of fluids obtained from human epididymal cysts.

The fluid composition of five epididymal spermatocoeles, one epididymal cyst and a hydrocoele was examined. The fluid obtained from the spermatocoeles was a dilute suspension of mainly immotile spermatozoa. The sperm-free fluid contained less protein, phosphate, glucose, triglyceride and cholesterol than serum but more testosterone and chloride than peripheral blood. It contained no epididymal secretion products. Proteins in the fluid differed from those in serum. From the fluid composition these cysts appeared to be continuous with the rete testis, either dilatations of efferent ducts or Haller's superior aberrant duct (vas aberrans of the rete testis). Fluid from an epididymal cyst containing no spermatozoa was mainly of similar composition. In contrast, hydrocoele fluid resembles blood serum.

Adult↗
PubMed1992

Appearance and endocytic activity of epithelial cells from human efferent ducts in primary monolayer culture.

The culture of epithelial cells lining human efferent ducts, obtained from prostatic carcinoma patients, is described. Ciliated cells were observed to beat for at least one month on plastic. On previous filters low cuboidal cells characterized the monolayers. Cells comprising monolayers over the filter were 5 to 9 microns in height whereas taller cells were found over the original fragments (14 microns). Some non-ciliated cells contained dark and light vacuoles, others were found to lack them. Both non-ciliated and ciliated cells maintained tight junctional complexes restricting the paracellular movement of horseradish peroxidase. Both types of cultured cells exhibited fluid-phase and adsorptive endocytosis from both apical and basal surfaces. It is reported for the first time that the monolayers form high resistance barriers (150 omega.cm2) that prevent the apical medium from draining to the basal compartment over 24 h.

Cell Polarity↗
PubMed1990

Effects of papaverine on human isolated bladder muscle.

Papaverine is a non-specific smooth muscle relaxant and is thought to act at a site beyond the receptor sites on the cell membrane. In this study the relaxing properties of papaverine were tested in isolated muscle strips from the human bladder dome. In carbachol-induced contractions papaverine, even in high concentrations of 10(-4) mol/l had virtually no effects on peak tension generation, whereas the fading was accelerated and the steady state tension at 30 min. was reduced by about 54%. In contrast, high potassium-induced contractions were relaxed by papaverine in a concentration-dependent way; a concentration of papaverine of 10(-4) mol/l produced full relaxation. These findings might possibly be explained if it is assumed that papaverine blocks calcium ion channels in the cell membrane. However, the observation that rather high concentrations of papaverine were necessary to fully relax high potassium contractions and the fact, that papaverine affects cellular cAMP levels separate this drug from more selective calcium channel blockers. The calcium movements responsible for the peak tension generation in carbachol-induced contractions are obviously not affected by papaverine. Although papaverine had little effect on carbachol-induced contractions in vitro it cannot be excluded that the drug is effective in diseases were non-cholinergic mechanisms are involved.

Calcium Channel Blockers↗
PubMed1989

Stimulation of calcium uptake by norepinephrine or high external potassium in human calyces and renal pelvis.

The effects of stimulation with either 10 mumol/l norepinephrine or 85 mmol/l extracellular potassium concentration on calcium uptake were studied in muscle strips from human renal calyces and from the renal pelvis. The apparent uptake of calcium under control conditions was essentially complete after 30 min. Stimulation of the muscle strips with norepinephrine or high external potassium significantly (P less than 0.05) increased the calcium uptake over the control values at 30 and 100 min, whereas 45Ca efflux was virtually not affected. It is concluded that the mechanical responses of the muscle strips to norepinephrine or high external potassium correspond with an increased uptake of calcium suggesting that both types of activation are mediated by an increase of intracellular calcium concentration similar to that described in other smooth muscles.

Calcium↗
PubMed1989

Critical evaluation of treatment of staghorn calculi by percutaneous nephrolithotomy and extracorporeal shock wave lithotripsy.

The combined use of percutaneous nephrolithotomy and extracorporeal shock wave lithotripsy in patients with staghorn calculi has become an established treatment regimen. We evaluated the results of 90 staghorn calculi-bearing kidneys treated with such combination therapy after a mean follow-up of approximately 2 years. A total of 69 kidneys (76.7 per cent) became free of stones at some point after treatment. However, due to stone recurrence this number decreased to 55 kidneys (61.1 per cent) at the end of follow-up. Patients who had undergone a previous open operation on the stone-bearing kidney showed less favorable results than the over-all group. When our results were compared to reported data on open surgery or percutaneous nephrolithotomy alone even better results may have been obtained by such treatment modalities. However, our data indicate that percutaneous stone debulking combined with further destruction of residual stone fragments by shock wave lithotripsy certainly is less invasive than an open operation and provides an alternative to percutaneous treatment alone, which can yield comparable results.

Adult↗
PubMed1989

Stimulation of voltage-dependent contractions by calcium channel activator Bay K 8644 in the human upper urinary tract in vitro.

The effects of calcium agonist Bay K 8644 on mechanical activity were studied in isolated preparations of the human upper urinary tract. Bay K 8644 increased the amplitude of phasic-rhythmic contractions in calyceal segments in a concentration-dependent way. In inactive and unstimulated ureteral muscle strips, Bay K 8644 did not induce contractions. After depolarization of ureteral segments with an extracellular potassium concentration of 48 mmol./l., Bay K 8644 produced a concentration-dependent increase of contractile force and enhanced phasic-rhythmic activity. The EC50 of the drug was 7.23 X 10(8) mol./l. The potassium and calcium concentration-response-curves were shifted to the left and the maximum force development was increased. Tonic contractions induced by norepinephrine in calyceal and pelvic segments were not affected by Bay K 8644, but the tendency for phasic-rhythmic activity was increased. In contrast to calcium-antagonistic dihydropyridines like nifedipine, the dihydropyridine derivative Bay K 8644 displayed completely opposite effects, which are obviously limited to voltage-induced activation. These observations can be explained by assuming that these agents act at sites that are components or are associated with voltage-controlled calcium channels. Occupation of these sites may either increase (Bay K 8644) or decrease (nifedipine) the transmembrane calcium flux into the cell.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1989

[Percutaneous treatment of a renal pelvis-calyx cholesteatoma].

A 54-year-old women reported recurrent pain in one side. Radiological and ultrasonographic examination revealed a mass in the left renal pelvis and the lower calyx. With percutaneous calycopyeloscopy keratinous fragments of a cholesteatoma were found and extracted during the same procedure. Up to now, malignant degeneration of a cholesteatoma has never been reported in the literature. Therefore, a conservative surgical treatment is acceptable.

Cholesteatoma↗
PubMed1986

Combined treatment of branched calculi by percutaneous nephrolithotomy and extracorporeal shock wave lithotripsy.

Eighty-seven patients with branched renal calculi were treated by a combination of percutaneous nephrolithotomy and extracorporeal shock wave lithotripsy. Stone debulking was achieved by percutaneous nephrolithotomy and residual stone fragments were destroyed by shock wave lithotripsy. Of the patients 70 (80 per cent) required 2 to 3 treatments, 12 (14 per cent) required 4 treatments and 5 (6 per cent) required 5 to 6 treatments. Results after 3 months indicated that 58 patients were free of stones, 3 had recurrent stones and 12 had disintegrated stone particles (less than 3 mm.) in the collecting system, while 13 were lost to followup. One patient had undergone nephrectomy. This treatment plan minimized the disadvantages of either technique when used alone and made open operative intervention unnecessary. Procedural and fluoroscopy times were reduced drastically compared to reported data on percutaneous nephrolithotomy only. We believe that more than 90 per cent of all branched calculi can be treated with this combined technique.

Adolescent↗
PubMed1986

Giant hydroureteronephrosis. Case report and review of the literature.

A case of giant hydroureteronephrosis in a man is reported. Diagnostic evaluation included ultrasound, urethrocystoscopy and percutaneous puncture to assess the outline of the urinary tract and to locate a suspected ectopic ureteral orifice. Standard treatment usually consists of primary nephroureterectomy. A review of the literature with respect to etiology, diagnostic criteria and treatment modalities is presented.

Adult↗
PubMed1986

[Effects of drugs on the upper urinary tract of the human].

The effects and the possible mode of action of some drugs were studied in isolated preparations of the human upper urinary tract. Norepinephrine, histamine and serotonin had excitatory effects, whereas isoprenaline had inhibitory effects on smooth muscle activity. Norepinephrine induced different types of mechanical activity in different tissues of the human upper urinary tract suggesting different and separate coupling mechanism between the receptors involved and the calcium pools responsible for initiation of contraction. Acetylcholine had only little effects on smooth muscle activity even in high concentrations. Contractions which were triggered by action potentials or depolarizing extracellular potassium concentrations were highly sensitive to calcium channel blockers. Other drugs with relaxing properties such as papaverine, bencyclane, flavoxate or pitofenone seem to have effects on different calcium activation or calcium storing mechanisms.

Calcium↗
PubMed1985

Calcium channel blocker nisoldipine limits ischemic damage in rat kidney.

The effects of the calcium channel blocker nisoldipine on renal function after 60 min. normothermic ischemia and contralateral nephrectomy were studied in male Wistar rats. Nisoldipine (300 ppm) was given in a standard diet as well as one hour prior to ischemia (10 mg./kg. orally). Survival, serum urea, serum creatinine, urine volume and creatinine clearance were used to test the effectiveness of the drug. Nisoldipine treatment resulted in the survival of all animals (compared to 66.6 per cent in the untreated group) and improved immediate and long term (14 days) renal function. The drug given post ischemia only was not effective, suggesting that nisoldipine must be present in the kidney during ischemia. The beneficial effects of the drug in postischemic acute renal failure may be attributed in part to effects on postischemic renal hemodynamics. Additional direct effects on ischemic renal epithelial cells, presumably by inhibiting transmembrane calcium fluxes, cannot be excluded.

Animals↗
PubMed1985

In vitro studies on human primary obstructed megaureters.

We studied isolated muscle strips from the dilated segments of primary obstructed megaureters from 2 children and 2 adults. The preparations were obtained at ureteral reimplantation procedures and mechanical activity was compared with that of normal ureteral segments obtained at tumor nephrectomies. In contrast to normal ureters, all the preparations of the megaureters of the children showed stable spontaneous phasic activity over several hours. The adult megaureters were inactive. In both tissues a marked tonic, sustained contraction could be induced by norepinephrine. This type of response is found in calyceal and pelvic tissues only in normal upper tracts. Normal ureters responded to norepinephrine with an increase in the frequency of spontaneous phasic contractions. The qualitatively different responses of the megaureters (in comparison to normal ureteral tissue) to alpha-adrenoceptor stimulation may be due to abnormal subcellular distribution of activator calcium in these hypertrophied tissues. The observed in vitro findings may be related to the radiographic observations of impaired and uncoordinated peristalsis in primary obstructed megaureters.

Acetylcholine↗
PubMed1984

Calcium channel blockade in smooth muscle of the human upper urinary tract. I. Effects on depolarization-induced activation.

The effects of the calcium blockers nifedipine, verapamil, D600 and diltiazem on mechanical activity were studied in isolated preparations of the human upper urinary tract. Two types of activity were used: spontaneous phasic-rhythmic activity in calyceal segments and potassium-induced depolarization in ureteral muscle strips. Nifedipine (10(-6) mol./l.), verapamil, D600 and diltiazem (all 10(-5) mol./l.) completely suppressed spontaneous phasic-rhythmic activity. Elevation of extracellular potassium concentration induced contractions concentration-dependently. A log-linear relationship between the extracellular calcium concentration and the 85 mmol./l. potassium-induced activation was demonstrated. Concentration-response relationships of the compounds were found by activating the muscle strips with 85 mmol./l. potassium in the Tyrode solution. This activation model produced stable and reproducible contractures. The compounds antagonized depolarization-induced activations concentration-dependently, nifedipine being the drug with the lowest EC50 value; its relative potency with reference to papaverine was about 8,000 to 1. The order of potency of the other drugs was in the following sequence: D600 greater than verapamil greater than diltiazem. It is concluded that processes in the human upper urinary tract which are triggered by depolarization (action potential or high potassium concentrations) are highly sensitive to calcium channel blockers.

Action Potentials↗
PubMed1984

Calcium channel blockade in smooth muscle of the human upper urinary tract. II. Effects on norepinephrine-induced activation.

The effects of the calcium channel blockers verapamil and nifedipine on norepinephrine-induced activation were studied in different tissues of the human upper urinary tract. In usually inactive ureteral muscle strips, norepinephrine induced predominantly phasic contractions with only minimal effects on resting tension. In contrast, in isolated segments of the renal calyx and pelvis, irrespective of preexisting spontaneous phasic activity, the same agonist effected a long-lasting tonic contraction. These different types of mechanical activity induced by norepinephrine showed different sensitivities to calcium channel blockers, phasic contractions being potently suppressed while the tonic response was little affected by the drugs. This different pattern of response to norepinephrine and the different sensitivity of the responses to calcium channel blockers suggest different and separate coupling mechanisms between the receptors involved and the calcium pools responsible for initiation of contraction. The existence of different calcium pathways activating the contractile proteins in the human upper urinary tract is postulated.

Calcium↗