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Biomedical subjects

S C Müller

Publications and source records attributed to S C Müller.

At least 73 records · Page 4Linked to original sources
PubMed1999

Molecular genetic diagnosis of de novo and recurrent bladder cancer.

Bladder cancer, the second most common urological tumor, is usually diagnosed by endoscopy and biopsy of the lower urinary tract. However, this procedure is expensive, can cause discomfort to the patient and is a source of infection. Commercially available diagnostic systems measure protein byproducts of bladder carcinoma in voided urine; their sensitivity is only between 60-80%. Polymerase chain reaction (PCR)-based microsatellite analysis of the urine sediment (MAUS) is a noninvasive, inexpensive and easily performed analytical method which was introduced in the de novo diagnosis and follow-up of bladder cancer. By utilizing the PCR with 20 polymorphic microsatellite markers on different chromosomes and separating PCR products by electrophoresis on 7% denaturing polyacrylamide-formamide-urea slab gels, a 91% diagnostic sensitivity could be achieved. In order to minimize costs and analysis time, the separation and detection of PCR products was carried out by capillary array electrophoresis and two-color fluorescent primer labeling/laser beam detection in another study. The accuracy of both methods was the same. In either detection system, MAUS is an accurate and promising tool in the noninvasive diagnosis of bladder cancer.

Carcinoma, Transitional Cell↗
PubMed1999

How to improve lithotripsy and chemolitholysis of brushite-stones: an in vitro study.

Because of their resistance to fragmentation, treatment of brushite stones is a big problem. This study was performed to look for an improvement in therapeutic strategies by using artificial stones made of brushite (Bon(n)-stones), which are comparable to their natural counterparts. Using an ultrasound transmission technique, longitudinal wave propagation speeds were measured at different time intervals during treatment with hemiacidrin. From these and density measurements, transverse wave speed, wave impedance and dynamic mechanical properties of the artificial stones were calculated. Moreover, the microhardness of artificial stones was measured and investigations on shock wave lithotripsy (SWL) combined with initial chemolytic treatment of the stones were performed. The suggestion was confirmed that stone fragility and thus SWL can be improved by varying the physical properties of brushite stones through treatment with hemiacidrin. Additionally, we demonstrated the efficacy of Suby G in dissolving artificial brushite stones using an experimental arrangement simulating the physiological conditions in the upper urinary tract. Moreover, the efficacy of four different intracorporeal lithotripsy devices (electrohydraulic, pneumatic, laser and ultrasound) was tested and it was shown that electrohydraulic lithotripsy seems to be the best system for comminution of brushite stones.

Calcium Phosphates↗
PubMed1999

Clinical course and histopathologic risk factor assessment in patients with bilateral testicular germ cell tumors.

OBJECTIVES: To determine whether the clinical course or the histopathologic risk factor assessment of the secondary tumor justifies early detection of the premalignant testis, since only 5% of contralateral testicular biopsies in the case of a testicular tumor reveal a testicular intraepithelial neoplasia (TIN). METHODS: From 1975 to 1997, 30 patients with bilateral germ cell tumors were treated; histologic and clinical data were available in all patients. In 12 patients, histopathologic re-evaluation and immunohistochemical staining of both tumors was performed for risk factor analysis. RESULTS: At the time the primary tumor was diagnosed, the mean patient age was 28 years. The metachronous secondary tumors were detected after a mean of 5.6 years. Seminoma was the predominant histologic finding in primary (53%) and secondary (56%) tumors. Eighty-three percent of patients had clinical Stage I (Lugano classification) disease at the diagnosis of the secondary tumor and 17% Stage II. Only 3 of 12 secondary tumors showed vascular invasion. The proliferation analysis (MIB-I score) showed a mean proliferation rate of only 34% within the primary and 26% within the secondary tumors. CONCLUSIONS: The results of our study show that the low clinical stage and good outcome associated with a histologic low-risk score of the secondary tumor does not mandate contralateral biopsy to detect TIN at the time of diagnosis of the first tumor.

Adult↗
PubMed1999

Sacral anterior root stimulation and cryotechnique: A new option for selective urethral sphincter block and reversible deafferentation in the future?

A possible application of cryotechnique might be a selective block of nerve fiber activity during sacral anterior root stimulation to achieve selective block of urethral sphincter and reversible deafferentation. In 13 foxhounds, electrical stimulation of sacral anterior roots S2 was performed while the accompanying spinal nerves were simultaneously cooled down from +25 degrees C in a stepwise fashion until a block of urethral sphincter activity was observed. The effects of cold block on the urethral sphincter and bladder were monitored by urodynamic investigation. In 2 additional dogs sacral posterior roots S2 were cooled down to +3 degrees C while accompanying anterior and posterior roots were stimulated distal to the cryothermode. Compound action potentials (APs) were registered proximal to the cryothermode before, during and after cooling and recovery time of cold blocked nerves was evaluated. Complete cold block of the urethral sphincter during spinal nerve cooling was achieved in all cases. Block temperature averaged +12 degrees C. Detrusor pressure was a mean 5,2 cm water. Recovery time was on average 5 min. The cold block was always reversible. In both dogs of the second series the compound action potentials disappeared nearly completely at +3 degrees C. Three min after the end of the cooling period the appearance of the compound action potentials was back to normal. In this study, cryotechnique proved to be effective for selective and reversible block of nerve fibers during sacral anterior root stimulation. In functional electrical stimulation this technique may lead to an improvement of quality of life in para- or tetraplegic patients resulting in optimization of voiding, standing, walking and grasping and does so without the necessity of surgical dorsal root rhizotomy.

Action Potentials↗
PubMed1999

Hydronephrosis after aorto bifemoral graft surgery: a marker for late graft complications.

Ureteral obstructions are serious late complications after aortoiliac reconstructive vascular surgery, which lead to loss of kidney function if they remain untreated. One case report serves to describe the incidence, aetiology, clinical presentation and treatment options of an obstructive uropathy following graft surgery. Hydronephrosis due to a ureteral obstruction is considered as a "marker" of graft complication. Therefore, ultrasound examination and close follow-up beyond 1 year are recommended in all patients who undergo aortoiliac surgery.

Aorta, Abdominal↗
PubMed1999

Electric-field-induced front deformation of Belousov-Zhabotinsky waves.

Experimental evidence is given of deformations in the vertical profiles of ferroin-catalyzed Belousov-Zhabotinsky waves propagating in thin horizontal cuvettes under an imposed dc electric field. While no deformations are seen in a zero field, for low negative field, or for any positive field, a pronounced S-shaped deformation does occur when a wave is exposed to a negative field above some critical magnitude. The observed phenomena are discussed on the basis of the convective flows that are assumed to increase in the negative field resulting from changes in the longitudinal profile of the wave.

Journal Article↗
PubMed1999

Squamous cell carcinoma of the penis.

Squamous cell carcinoma of the penis is a rare disease in Western countries. In geographical locations where infantile circumcision is not routinely practised and genital hygiene is poor, penile cancer may comprise 10-20% of all malignancies. Superficial tumours (Ta-Tl) should be treated with organ-preserving therapy. Partial of total penectomy is recommended for invasive penile carcinoma (stage T2 or higher). Currently, management of the ilioinguinal lymph nodes is controversial. The value of radiation therapy and chemotherapy is still uncertain; these treatments are only palliative therapy modalities.

Carcinoma, Squamous Cell↗
PubMed1998

Traveling waves in yeast extract and in cultures of Dictyostelium discoideum.

Biological self-organization was investigated in a biochemical and a cellular system: yeast extract and cultures of the slime mold Dictyostelium discoideum. In both systems traveling reaction-diffusion waves occur in response to oscillatory reactions. Glycolytic degradation of sugar in a yeast extract leads to the spontaneous formation of NADH and proton waves. Manipulation of the adenine nucleotide pool by addition of purified plasma membrane ATPase favors the formation of both reaction-diffusion waves and phase waves. The results indicate that the energy charge has an important impact for the dynamics of glycolytic patterns. When affecting the lower part of glycolysis by pyruvate addition the frequency of wave generation was increased with concomitant formation of rotating NADH and proton spirals. During morphogenesis of the cellular system Dictyostelium discoideum, circular and spiral shaped aggregation patterns of motile amoeboid cells form in response to traveling cAMP waves. Velocity analysis of the cell movements reveals that the cAMP waves guide the cells towards the site of wave initiation along optimized trajectories. The minimization of aggregation paths is based on a mechanism exploiting general properties of excitation waves. The resulting aggregation territories are reminiscent of Voronoi diagrams.

Animals↗
PubMed1998

[Indications for nuclear medicine therapy in advanced prostate carcinoma].

For patients with advanced prostate cancer efficient therapy of painful bony lesions is the primary goal of interdisciplinary treatment strategies. Preservation of quality of life appears to be the main aim rather than prolongation of life. Apart from oral pain relief and local irradiation systemic treatment with radionuclides offers low-risk radiotherapeutic strategies for the palliation of painful, multifocal osteoplastic bone metastases. Depending on the radiopharmaceutical substance chosen response and reduction of pain are described in 65-80%. The duration of pain relief lasts between 6-12 weeks. During this time the morphine based medication can be reduced and in some cases withdrawn which positively effects quality of life. After improvement of myelosuppression treatment with radionuclides can be repeated. Patients have to be hospitalized for two days because of protection from radiation procedures.

Bone Neoplasms↗
PubMed1998

[Testicular tumors. Mortality and recurrence after inadequate therapy].

From 1983 to 1994, 293 patients with testicular germ cell tumors were treated at the Department of Urology, Bonn University, Germany. 252 patients (86%) were available for follow-up studies. 17/252 (6.8%) of patients died of disease, 41/252 (16%) had a tumor recurrence after complete remission. 20/41 (49%) patients with recurrence, who mainly had been referred for further treatment, had been treated inadequately. Inadequate treatment consisted of surgical failures after orchiectomy, incomplete retroperitoneal lymph node dissection after chemotherapy, delay of treatment, and inadequate chemotherapy. 80% of recurrences were found within the first two years after treatment, late relapses were found in 3.6%. Early recurrences were mainly pulmonary, late recurrences mostly occurred in the retroperitoneum or atypical. 20% of all recurrences were local recurrences.

Adult↗
PubMed1998

Idiopathic anterior urethritis in prepubertal and pubertal boys: pathology and clues to etiology.

OBJECTIVES: Records were reviewed to examine the common features of boys with noninfectious anterior urethritis, and to describe the underlying pathology. METHODS: Five cases of anterior urethritis with features typical of this syndrome are reviewed. RESULTS: These cases demonstrate the typical appearance and in 1 case the pathologic diagnosis of squamous metaplasia of the bulbar urethra. CONCLUSIONS: Prepubertal urethrorrhagia is associated with squamous metaplasia of the urethra. The tendency to stricture formation may precede instrumentation of the urinary tract.

Adolescent↗
PubMed1998

Efficacy and safety of transurethral alprostadil therapy in men with erectile dysfunction. MUSE Study Group.

OBJECTIVE: To examine the safety and efficacy of transurethral pharmacotherapy for erectile dysfunction, involving the use of a novel therapeutic system to administer alprostadil (prostaglandin E1) to the urethral mucosa in a double-blind, randomized, parallel, placebo-controlled study conducted in five countries in Europe. PATIENTS AND METHODS: In an outpatient setting, patients with primarily organic erectile dysfunction of at least 3 months' duration were treated with transurethral alprostadil, in an open-label, dose-escalating study. Testing stopped when the dose provided an erection sufficient for intercourse, as assessed by the patient and the investigator. Patients who achieved a sufficient response were then randomized to either active medication at the selected dose or to placebo for use at home for 3 months. After each home administration, patients recorded in diaries whether or not sexual intercourse occurred and any adverse reactions to the drug. RESULTS: A total of 249 patients were treated in an outpatient setting; of these patients, 159 (64%) achieved an erection sufficient for intercourse and were randomized (1:1) to either active medication or placebo for home treatment. Of the patients randomized to alprostadil for home treatment, 69% reported intercourse at least once, compared with 11% of patients randomized to placebo (P < 0.001). The most common adverse reaction, urethral pain/burning, was reported by 7% of patients in the clinic. Most patients (83%) graded transurethral alprostadil as causing minimal or no discomfort in the clinic. No patient reported priapism or developed penile fibrosis. CONCLUSION: Alprostadil delivered transurethrally by this system was well tolerated and effective in treating erectile dysfunction.

Adult↗
PubMed1998

The effect of transurethral alprostadil on the quality of life of men with erectile dysfunction, and their partners. MUSE Study Group.

OBJECTIVE: To evaluate the impact of treatment for erectile dysfunction on the quality of life of men and their partners. PATIENTS AND METHODS: The study included 249 men with organic erectile dysfunction of more than 3 months' duration who self-administered transurethral alprostadil in an open-label, dose-escalating manner in an outpatient medical setting. Patients with a sufficient response (159) were randomly assigned in a double-blind protocol to either active medication or placebo for 3 months at home. Patients and partners each completed quality-of-life questionnaires before and after treatment. RESULTS: In the clinic 159 of the 249 men (64%) had an erection sufficient for intercourse when using transurethral alprostadil. At home, 46 of 67 men (69%) reported intercourse at least once on transurethral alprostadil, compared with eight of 73 (11%) on placebo (P < 0.001). Patients on alprostadil showed a 34% improvement in their 'relationship with partner', a 5% improvement in 'personal wellness', and a 71% improvement in 'quality of erection' domains, compared with a decline of 11%, 8% and 1%, respectively, in patients on placebo (P < 0.005 for each comparison). Partners of patients on alprostadil showed a 35% improvement in the 'relationship with partner' domain, compared with a 12% improvement in the placebo group (P = 0.028). There was a trend toward improvement in other partner domains. Urogenital pain was reported by 14% of patients during home treatment. CONCLUSION: The resumption of sexual intercourse with the use of transurethral alprostadil was accompanied by an improvement in several important quality-of-life domains in patients and their partners.

Adult↗
PubMed1998

[Urinary incontinence in neurogenic defects and urogenital anomalies in childhood].

Dysraphic defects may cause neurogenic incontinence in childhood. Constipation and encopresis are often associated. Depending on the involved segment of the spinal cord hyperreflexia or atonia of the detrusor is observed. Similar findings, without anatomic correlation, can be seen in occult-neurogenic voiding dysfunctions. Therapeutic means aim at preservation of kidney function and the best possible continence. If the symptoms cannot be treated by anticholinergic drugs in a low-capacity, hypertonic bladder, augmentation by bowel segments or continent urinary diversion (e.g. Mainz I pouch) is performed. In the last years modalities of clean intermittent self-catheterization in high-capacity, atonic bladders could be enhanced by the development of new atraumatic catheter systems. Urogenital malformation e.g. proximal epispadias and exstrophic bladder can cause incontinence as well. Recently, new therapeutic concepts were introduced. Ectopic ureter (extraurethral incontinence) in girls or posterior urethral valves in boys as a reason for incontinence must not be forgotten.

Child↗
PubMed1997

MIB-1 immunohistochemistry in clinical stage I nonseminomatous testicular germ cell tumors predicts patients at low risk for metastasis.

BACKGROUND: The clinical Stage I of nonseminomatous germ cell tumors (NSGCT) is inaccurate in 30% of patients. In previous studies on tumor biologic risk factors, low tumor proliferation rates predicted a group of patients at low risk for occult metastatic disease. The goal of this study was to confirm the immunohistochemical assessment of tumor proliferation using MIB-1 (Ki-67 receptor) in a different patient cohort with different investigators to prove the method's reliability. METHODS: Orchiectomy specimens of 78 patients with clinical Stage I NSGCT (50 patients with pathologic Stage I and 28 patients with pathologic Stage II disease, all patients underwent retroperitoneal lymph node dissection) were retrospectively analyzed by histopathologic reevaluation and MIB-1 immunostaining. RESULTS: Mean MIB-1 values between the two pathologic stages differed significantly (51.5% MIB-1 positive tumors cells in pathologic Stage I and 75.1% MIB-1 positive tumor cells in pathologic Stage II disease; P = 0.02). Using a 70% cutoff value, pathologic stages were correctly classified in 69% of cases (sensitivity of 86%, specificity of 60%, negative predictive value of 88%, and positive predictive value of 55%). Compared with traditional risk factors such as percentage of embryonal carcinoma and vascular invasion, in multivariate analysis, MIB-1 was the best predictor of patients at low risk for metastasis. CONCLUSIONS: This study in a different patient population with different investigators confirmed previous results of MIB-1 staining to predict a group of patients with clinical Stage I NSGCT who were at low risk for metastasis. The method is simple and reproducible to improve risk classification in low stage testicular carcinoma. Using this technique, a group of patients at very low risk for metastasis can be identified. [See editorial counterpoint on pages 1641-5 and reply to counterpoint on page 1646, this issue.]

Antibodies, Monoclonal↗
PubMed1997

Self-induced splitting of spiral-shaped spreading depression waves in chicken retina.

Spreading depression (SD) of electroencephalographic activity is a dynamic wave phenomenon in the central nervous system (CNS). The retina, especially the isolated chicken retina, is an excellent constituent of the CNS in which to observe the dynamic behavior of the SD wave fronts, because it changes its optical properties during a SD attack. The waves become visible as milky fronts on a black background. It is still controversial what the basic mechanistic steps of SD are, but certainly SD belongs to the self-organization phenomena occurring in neuronal tissue. In this work, spiral-shaped wave fronts are analyzed using digital video imaging techniques. We report how the inner end of the wave front, the spiral tip, breaks away repeatedly. This separation process is associated with a Z-shaped trajectory (extension approximately 1.2 mm) that is described by the tip over one spiral revolution (period 2.45+/-0.1 min). The Z-shaped trajectory does not remain fixed, but performs a complex motion across the retina with each period. This is the first time, to our knowledge, that established imaging methods have been applied to the study of the two-dimensional features of SD wave propagation and to obtaining quantitative data of their dynamics. Since these methods do not interfere with the tissue, it is possible to observe the intrinsic properties of the phenomenon without any external influence.

Animals↗
PubMed1997

[Treatment of benign prostatic hyperplasia with alpha 1-adrenoreceptor antagonists].

The International Consensus Committee recommends alpha-adrenoceptor antagonists for medical therapy benign prostatic hyperplasia (BPH). This review evaluates 52 randomized, placebo-controlled, double-blind studies, including 10399 patients and, moreover, 40 clinical studies including 33600 patients undergoing treatment with alpha-adrenoceptor antagonists because of BPH. The therapeutic efficacy of all alpha-adrenoceptor antagonists is more or less the same. There is an average improvement of symptom scores of about 35% and a mean increase in maximum flow rate of between 1.8 and 2.5 ml/s. Studies investigating long-term efficacy and quality of life tend to show a long-term benefit. The introduction of selective alpha 1-adrenoceptor antagonists led to a significant reduction of side effects. These side effects are primarily caused by the vasodilatatory qualities of alpha-blockers. The development of so-called uroselective alpha 1A-adrenoceptor antagonists in the treatment of BPH possibly leads to further reduction of side effects related to vasodilatation. Medical therapy by alpha 1-adrenoceptor antagonists seems to be superior to phytotherapy or treatment with 5 alpha-reductase inhibitors, as shown in a few studies. So far, it is not clear whether there is any advantage of combination therapy. The application of alpha 1-adrenoceptor antagonists is indicated in all cases of symptomatic BPH, excluding patients who need TUR-P (e.g., middle lobe) or prostatectomy. If patients are either willing or eligible to have surgical treatment, therapy by alpha 1-adrenoceptor antagonists is a rational choice. Comparative clinical trials have to be conducted to provide additional information and to clarify which alpha-blocker may be recommended as the first choice. Until then, those alpha 1-adrenoceptor antagonists should be used for which safety and efficacy are well documented and which can be prescribed at reasonable costs.

Adrenergic alpha-1 Receptor Antagonists↗