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D Ackermann

Publications and source records attributed to D Ackermann.

At least 55 records · Page 3Linked to original sources
PubMed1990

Rapid method of measuring the inhibition of calcium-oxalate monohydrate growth in urine.

In order to have a rapid method of measuring the inhibition of calcium-oxalate monohydrate growth in freshly voided whole urine, a test system by Meyer and Smith that has originally been developed for diluted urine was modified. The crystallization processes were monitored by an ion-selective calcium electrode, which allowed determination of the half-life value of the decrease in calcium within 25 min. Even given the high inhibitory activity of whole urine, the test gave reliable results when a high seed concentration was used. Inhibition was expressed as the ratio between the half-lives of the calcium decrease obtained in the presence and in the absence of inhibitors. This approach allowed kinetic studies of individual inhibitors in model solutions. Furthermore, the measurements of inhibitors in urine could be performed before the chemical composition was determined.

Calcium Oxalate↗
PubMed1990

Prophylaxis in idiopathic calcium urolithiasis.

The most important measure in the prophylaxis of idiopathic calcium urolithiasis is dietary advice. Patients should be kept to a high-fluid intake, increasing their diuresis by at least 0.51. The mineral content of drinking water seems to be of minor importance, but the liquid should be low in carbohydrates and oxalate. The intake of animal proteins should be reduced to no more than five meals with meat, fish or poultry per week. Excesses of oxalate-rich food must be avoided. The daily intake of calcium in dairy products should be in the range of 800-1200 mg. Sodium and refined carbohydrates should be moderately restricted. Medical treatment is indicated only in cases of recurrence under the appropriate diet. Selective treatment according to urinary chemical composition is favoured; alkali citrate, thiazides, allopurinol, and pyridoxine are of major interest.

Calcium↗
PubMed1990

Enlargement of regional lymph nodes in renal cell carcinoma is often not due to metastases.

Preoperative axial computerized tomography scans in 163 patients with renal cell carcinoma were reviewed to assess the predictive value for the diagnosis of regional lymph node metastases. Computerized tomography was falsely negative in 5 patients: 2 had metastatic lymph nodes in the renal hilus adjacent to the primary tumor measuring 2 and 2.5 cm., and 3 had micrometastases in nodes of less than 1 cm. In 43 patients enlarged lymph nodes with a diameter of 1 to 2.2 cm. (median 1.4 cm.) were diagnosed on the preoperative scan and this was confirmed at nephrectomy and pathologically. In 18 of these 43 patients (42%) histological study showed metastases of the renal cell carcinoma in the enlarged lymph nodes. In the other 25 patients (58%) the enlarged nodes showed only inflammatory changes and/or follicular hyperplasia. This finding was significantly more frequent in patients with tumor involvement of the renal vein and tumor necrosis (p = 0.0044). We conclude that the sensitivity of preoperative computerized tomography is good for the detection of enlarged lymph nodes in patients with renal cell cancer (95%). However, significant lymph node enlargement frequently may be caused by inflammatory changes, especially in the presence of tumor necrosis. This radiological finding should not be misinterpreted as metastatic disease, unless it has been proved cytologically by fine needle aspiration.

Carcinoma, Renal Cell↗
PubMed1989

[Clinical experiences with extracorporeal shockwave lithotripsy].

Clinical experience with 2738 patients treated by extracorporeal shock wave lithotripsy between March 1985 and December 1988 is reported. All treatments were performed with the Dornier HM-3 lithotriptor. 34% of the patients needed auxiliary measures, consisting primarily of urological manipulation to improve urinary drainage or for better localization and/or focussing of the stones. Severe complications were rare; urosepticemia occurred in 0.3%, 2 patients had to undergo nephrectomy because of abscessing pyelonephritis, and there was one death due to recurrent pulmonary embolism in a patient with polycythemia vera. ESWL was used for stones in the entire upper urinary tract. The stone free rate for pelvic calculi smaller than 2 cm was 79% three months after treatment; a further 16% showed desintegrated material smaller than 5 mm, augmenting the success rate to 95%. The success rate dropped to 74% for very large renal stones of more than 4 cm. A stone free rate of 84-96% was ascertained for ureteral calculi 3 months after ESWL. Absolute contraindications for ESWL are acute pyelonephritis, coagulation disorders and pregnancy. The patients must tolerate anesthesia, as most treatments with this lithotriptor must be carried out under peridural or general anesthesia and only in a few exceptional cases is treatment in sedoanalgesia possible. ESWL is now generally accepted in view of its negligible invasiveness, low morbidity and the high success rate. Modern treatment of urinary calculi is inconceivable without considering ESWL.

Adolescent↗
PubMed1989

The influence of hydroxyapatite and pyrophosphate on the formation product of calcium oxalate at different pHs.

The nucleating effect of hydroxyapatite (HAP) and the inhibitory effect of pyrophosphate (PPi) on calcium oxalate crystallization have been studied at different pH's in solution metastabely supersaturated with respect to calcium oxalate but saturated with respect to HAP. Crystallization was monitored by a decrease of calcium in the supernatant and formation products were calculated. At a pH above 6.0 already minimal HAP concentrations proved to be a suitable substrate for heterogeneous nucleation and growth of calcium oxalate. PPi showed a pronounced inhibitory effect on spontaneous as well as on HAP induced crystallization of calcium oxalate, this effect being highly pH dependent. HAP was found to neutralize the inhibitory effect of PPi in a molar ratio of 10:1.

Calcium Oxalate↗
PubMed1989

Overview of surgical treatment of urolithiasis with special reference to lithotripsy.

In the early 1980s, 2 elegant innovations were added to open surgery in the management of stones: endourology and extracorporeal shock wave lithotripsy. The decision strategy for treating stones is not yet codified and it depends on several factors, such as equipment, type and size of stones, needs of the patient and skills of the surgeon. After open stone surgery convalescence lasts approximately 4 to 6 weeks and repeated surgery is more difficult. With endourology convalescence can be reduced to a few days in an uncomplicated case, the risk of complication is approximately 10 per cent and retreatment is not more complicated. Convalescence with extracorporeal shock wave lithotripsy often is negligible and some extracorporeal shock wave lithotripsy units are run on an outpatient basis. However, as with all stone surgeries, extracorporeal shock wave lithotripsy causes renal bleeding of varying degrees. There are reports of diastolic hypertension after extracorporeal shock wave lithotripsy in up to 8 per cent of the patients. Retreatment is easy but the late consequences of retreatment are unknown. Extracorporeal shock wave lithotripsy is the dominant means of surgical management for stones in the western world; 87 per cent of our patients are treated with extracorporeal shock wave lithotripsy and 4 per cent with open surgery.

Humans↗
PubMed1989

Three years' experience with an ileal low pressure bladder substitute.

At the beginning of this century it was realised that peristalsis would cause incontinence if bowel was used for augmentation or substitution of the bladder. Trans-section of the antimesenteric border and cross-folding of the intestinal segments (Goodwin's cup-patch technique) is an efficient means of solving this problem and has been successfully used in the Kock pouch. We anastomosed the ileal low pressure reservoir to the membranous urethra in 22 male patients following radical cystoprostatectomy for bladder cancer. The mean observation time was 16 months (range 3-36). The capacity of the bladder substitute increased with time, the average being 450 ml after 6 months. In the first 4 patients with a short (2-5 cm) intestinal segment between the pouch and the urethra, micturition was prolonged, residual urine varied from 50 to 300 ml and bacteriuria was found. Occasional expulsions of several ml of urine were caused by peristalsis within this short tubular segment. In the following 18 patients, the low pressure reservoir was anastomosed directly to the membranous urethra. Micturition was good, with no notable residual urine, no bacteriuria and no paroxysmal urinary incontinence. However, a safety pad is used by half of the patients because once or twice a week, mainly at night, a few ml of urine may be lost. No significant changes in serum electrolytes, bicarbonate or creatinine were noted. With the three different antireflux techniques used, no obstructive or inflammatory changes in the upper urinary tracts were found, although no long-term antibiotic prophylaxis was given.

Aged↗
PubMed1989

Use of the computer program EQUIL to estimate pH in model solutions and human urine.

The computer program EQUIL was designed to calculate relative supersaturations of solute components of common urinary stones. In an extended software version, quantitative consideration of charge balance for a priori or a posteriori pH estimation was added. The reliability of this computation was tested with hydrogen ion titration of buffer solutions containing HEPES [N-(2-hydroxyethyl)piperaizine-N'-ethanesulfonic acid] as well as samples of normal human urine. In the model solutions with HEPES, the difference between calculated pH values and the measured pH was smaller than 1.2% for any titration step within the buffer zone (pH 8.5-6.8). The pH values calculated for whole urine differed from the measured pH by 7% to 53%, and the calculated charge inbalance ranged from 2.6 to 9.6 mM. This net cation inbalance indicates that there is a need to account for other anionic components, including hippurate, amino acids, and isocitrate. In experimental solutions, charge balance calculations with EQUIL can be of great utility because they permit a priori estimation of pH or computation of the composition at a desired pH.

Buffers↗
PubMed1989

[Treatment of carcinoma in situ of the urinary bladder with BCG].

In a prospective study 55 patients with primary or secondary carcinoma in situ of the bladder were treated with BCG. With an overall response rate of 85%, results reported by other authors can be confirmed. In relationship with the effectiveness of the treatment, the side-effects can be considered as acceptable. Therapy failure suggests extravesical or invasive carcinoma.

Administration, Intravesical↗
PubMed1988

Treatment of superficial bladder tumors with intravesical recombinant interferon alpha-2a.

In a prospective study, the toxicity and efficacy of an instillation therapy with recombinant interferon alpha-2a (rIFN-alpha-2a) were evaluated in 12 patients with superficial bladder tumors. Treatment consisted of 8 weekly instillations of 54 X 10(6) IU rIFN-alpha-2a in 50 ml saline. Two weeks after completion of the instillation therapy, the tumor status was assessed with cystoscopy, biopsy and bladder wash-out cytology. Two partial responses, 1 no change and 2 progressive disease were seen in the 5 patients with TA tumors. In the 4 patients with carcinoma in situ, 1 complete response, 1 partial response and 2 no change were observed. Three patients suffered from carcinoma in situ and superficial papillary tumors, 1 showed complete response of the carcinoma in situ but no change of the TA tumor, the other 2 patients showed progressive disease. Three patients with partial response received a follow-up combination therapy with interferon intravesically and etretinate orally (25 mg/day). These patients presented progressive disease or no change 10 weeks after starting the follow-up combination therapy. During the treatment period, no side effects of interferon or changes of the serum interferon levels were observed. The treatment results are considered unsatisfactory; nevertheless, some activity after intravesical administration of interferon (mainly in patients with carcinoma in situ) could be demonstrated. Since the cytotoxic and antiproliferative effects seem to be dose-dependent, further studies might be done using higher interferon dosages and shorter treatment intervals.

Administration, Intravesical↗
PubMed1988

Influence of calcium content in mineral water on chemistry and crystallization conditions in urine of calcium stone formers.

19 idiopathic recurrent calcium stone formers were examined on a constant diet supplemented with mineral water of high (386 mg/l) and low (10 mg/l) calcium content. The effects of calcium and oxalate loading were studied separately. Ingestion of mineral water with high calcium content lead to an increase of urinary calcium and a decrease of urinary oxalate compared to mineral water with low calcium content. On the calcium-rich mineral water, urinary saturation with Whewellite was lower and it hardly reached the critical level for calcium oxalate crystallization after oxalate loading, which was in contrast to the results on low calcium mineral water. Urinary Brushite saturation was generally low and showed no significant differences between the two mineral waters.

Adult↗
PubMed1988

Extracorporeal shock wave lithotripsy for large renal stones. To what size is extracorporeal shock wave lithotripsy alone feasible?

The complications after extracorporeal shock wave lithotripsy (ESWL) for large renal calculi could be reduced by insertion of ureteral stents. In a prospective study, the critical stone size for ESWL combined with ureteral stenting was looked for. Sixty consecutive patients entered the study, 17 patients suffered from renal calculi with a length of greater than 4 cm and a width of greater than 3 cm (group 1), and in 43 patients the calculi measured between 4 x 3 and 2.5 x 1.5 cm2 (group 2). ESWL was performed with the Dornier apparatus HM-3. A ureteral stent was placed immediately before ESWL. In group 1 with very large stones, significantly more obstructive problems were encountered. Three months after ESWL, only 6 of 14 (43%) were free of stones or with stone material likely to discharge spontaneously. In group 2, a success rate of 25 of 29 (86%) was noticed, which was considered satisfactory. For most stones greater than 4 x 3 cm2 the combination of percutaneous nephrolithotomy and ESWL seems to be the preferred treatment.

Adult↗
PubMed1987

[Extracorporeal shockwave lithotripsy: experience with 1000 treatments].

6 1/2 years after the first clinical trials in Munich, extracorporeal shockwave lithotripsy is a well established method for the treatment of urinary tract calculi. The number of open surgical interventions in urolithiasis has therefore markedly diminished. In hospitals with lithotriptors open surgical procedures are less than 1% today. In the first 16 months the Department of Urology at the University of Berne performed 1000 treatments with a kidney stone lithotriptor. The treatment was successful in 93.8%, a result comparable with those of other stone centres. During the last few months the indication for the treatment has been considerably enlarged. The new lithotriptors differ in several respects from the standard model by Dornier, though basically the principle of shockwaves remains unchanged.

Adolescent↗
PubMed1987

Chemical factors governing the state of saturation towards brushite and whewellite in urine of calcium stone formers.

Variations of urinary pH and concentrations of calcium, phosphate, oxalate, magnesium and citrate have been produced by 4 different diets given to 19 idiopathic calcium stone formers. The state of saturation towards whewellite and brushite was directly measured in the 76 urine samples by equilibration with the corresponding salts and was compared to chemical constituents by regression analyses. The state of saturation towards calcium oxalate monohydrate was significantly governed only by the urinary oxalate concentration, and a soluble oxalate fraction not contributing to calcium oxalate chelation was demonstrated. The state of saturation towards brushite was exclusively determined by urinary calcium and pH, the latter below 5.5 showing a high influence on brushite solubility.

Adolescent↗