Biomedical subjects

S C Müller

Publications and source records attributed to S C Müller.

At least 19 recordsLinked to original sources

PubMed1992

Conservative surgery of renal cell tumors in 140 patients: 21 years of experience.

Operative method, course and complications were analyzed retrospectively in 140 patients who underwent a conservative operation for renal tumor between June 1969 and December 1990. In 53 patients (20 women and 33 men, mean age 61.2 years, range 38 to 77 years, with 49 renal cell carcinomas and 4 benign renal tumors) there was an imperative indication for an organ preserving operation because nephrectomy would have made dialysis obligatory. In 87 patients (29 women and 58 men, mean age 53.7 years, range 27 to 74 years, with 72 renal cell carcinomas and 15 benign renal tumors) the tumor was conservatively resected in the presence of a normal contralateral unit (elective indication) and 68 of these patients (78%) were symptom-free. In the imperative group 32 of 49 patients (65.3%) with renal cell carcinoma had no evidence of disease after a mean followup of 4.6 years. Known metastases were present in 4 of 7 patients who died of the tumors in this group. In 3 patients with an imperative indication for conservative surgery a second tumor occurred in the kidney: 2 were treated with further parenchyma sparing operations, while in 1 with poor physical condition no further measures were possible. Of 72 patients with renal cell carcinoma who underwent an elective operation 68 (94.4%) had no signs of tumor progression after a mean followup of 3.3 years. One patient died of tumor metastases, and 2 (2.7%) had tumor recurrence in the kidney requiring nephrectomy and enucleation, respectively. The 5-year cause-specific survival rates for the imperative and elective groups were 84% and 96%, respectively. Patients with a local stage T3 tumor were characterized by a significantly worse survival curve than those with a stage T1 or T2 tumor but no significant difference was noted among the various grades of differentiation.

Adult↗

PubMed1992

The buccal mucosal graft for urethral reconstruction: a preliminary report.

Autologous buccal mucosa as a substitute for urethral epithelium was studied in 2 dogs and used in 6 patients with difficult urethral reconstruction problems. The indications for an operation in these patients were failed hypospadias repairs with limited skin in 3, severe structure disease after hypospadias repair in 1, a short urethra in 1 and epispadias in 1. Three urethral fistulas and 1 meatal stenosis occurred in 3 patients. No urethral stricture or diverticulum was noted, and the final outcome was good functionally and cosmetically in all patients. This technique is useful for urethral reconstruction when local skin is not available.

Adolescent↗

PubMed1992

The appendix as a continence mechanism.

Although we have progressed very well in creating large capacity, low pressure reservoirs, the construction of a simple and reliable continent outlet still remains a problem. The appendix vermiformis serves well as a continence mechanism for either the bladder or intestinal reservoirs for urine. The different surgical techniques described in the literature are reviewed and discussed in this context. Moreover, we report on our clinical and experimental results of using the appendix during the Mainz pouch procedure for continent urinary diversion.

Adolescent↗

PubMed1991

Hypertension and impotence.

In a group of 472 impotent patients who were evaluated with pharmacologic duplex sonography, 117 patient (24.8%) had a history of hypertension, 26 of them (22.2%) for more than 10 years. Objective data about the changes in pulsation, diameter and blood flow velocity of the penile arteries after papaverine injection and the resulting erectile response allowed indirect assessment of the penile venous function. Varying degrees of impaired arterial function were diagnosed in 85% of the patients. The duration of hypertension had less deteriorating effects on the penile arterial system than second risk factors such as diabetes mellitus (n = 31) or smoking (n = 26). Patients on antihypertensive medication (n = 88, 75.2%) demonstrated a worse arterial response to papaverine than those without medication (n = 29, 24.8%). The best vascular response to papaverine injection was found in patients taking a combination of beta-blockers and vasodilators (n = 6), whereas thiazides either taken alone or in combination (n = 51, 60%) seem to have a deteriorating effect on arterial function. However, the arterial response did not correlate with the ability to achieve 'full erection' after intracavernous papaverine injection. Clinical experience confirms that certain antihypertensive drugs affect not only the blood pressure, but also compliance of the erectile tissue resulting in a functional venous leak. This may impair erectile function as much as arteriosclerotic changes of the vascular system secondary to hypertension.

Antihypertensive Agents↗

PubMed1991

Percutaneous transpenile and retrograde venous occlusion for the treatment of venous leak impotence.

In 17 patients percutaneous transpenile venous occlusion was performed for the treatment of so-called venous leak impotence. Because of primary failure, the procedure was repeated in 5 patients. On four occasions, it was combined with a retrograde venous occlusion via the internal iliac vein. Within a rather short follow-up period of 23 months maximum, the overall success rate is 65%. Six patients are able to have intercourse and 5 others need additional intracavernous injections. Complications of the procedure were not observed.

Adult↗

PubMed1991

Long-term experience with conservative surgery of renal tumors. Surgical technique, complications, results, DNA-cytometry.

The surgical technique, course and complications were analysed in 123 patients in whom a kidney tumor had been enucleated. Fifty-seven enucleated tumors were available for image analysis DNA-cytometry. In 49 patients there was an imperative indication for an organ-preserving operation, because nephrectomy would have made dialysis obligatory. In 74 patients with a healthy contralateral kidney the tumor was enucleated by choice. Thirty-five of 49 patients with an imperative indication are without sign of tumor progression after a mean follow-up of 4.5 years. In two patients there was a recurrence after 4 and 5 years, respectively, requiring a second organ-preserving operation. In one further patient there is a suspicion of multiple small tumor lesions 2 years after the first operation. Known metastases were present in 3 of 6 patients who died of their tumors. Sixty-eight of 74 patients operated on electively are without signs of tumor progression after a mean follow-up period of 3.3 years. One patient died from tumor metastases. Two patients had tumor recurrence, requiring nephrectomy and enucleation, respectively.

Adult↗

PubMed1991

[Pathophysiology of erectile dysfunction--diagnostic and therapeutic consequences].

During the past decade innovative research results in a better understanding of the physiology of erection and the pathophysiology of impotence. The smooth muscle of the cavernous bodies of the penis plays a major role in regulating the hemodynamics of erection. Pharmacologically induced artificial erection brought a new era in the diagnosis and treatment of impotence. Combining these injection techniques with Duplex-ultrasound a more functional and objective evaluation of the penile vasculature is possible. Based on this "one step" diagnostic work-up an improved and widened spectrum of therapeutic modalities can be offered to the patient.

Animals↗

PubMed1991

[Erectile dysfunction: principles of radiologic clarification and therapy].

Diagnosis of erectile dysfunction is performed by means of Doppler sonography, cavernosography and cavernosometry, as well as by angiographic methods. Interventional radiological treatment methods are, arterially, vasodilatation or vasorecanalisation, and, as far as the venous approach is concerned, percutaneous venous occlusion. The article reviews the diagnostic and therapeutic radiological methods.

Catheterization↗

PubMed1990

The role of fructose 2,6-bisphosphate in glycolytic oscillations in extracts and cells of Saccharomyces cerevisiae.

Fructose 2,6-bisphosphate is physiologically one of the most potent activators of yeast 6-phosphofructo-1-kinase. The glycolytic oscillation observed in cell-free cytoplasmic extracts of the yeast Saccharomyces cerevisiae responds to the addition of fructose 2,6-bisphosphate in micromolar concentrations by showing a pronounced decrease of both the amplitude and the period. The oscillations can be suppressed completely by 10 microM and above of this activator but recovers almost fully (95%) to the unperturbed state after 3 h. Fructose 2,6-bisphosphate shifts the phases of the oscillations by a maximal +/- 60 degrees. Oscillations in concentration of endogenous fructose 2,6-bisphosphate in the extract were also observed. Fructose 2,6-bisphosphate alters the dynamic properties of 6-phosphofructo-1-kinase which are vital for its role as the 'oscillophore'. However, the minute amount (approximately 0.3 microM) of endogenous fructose 2,6-bisphosphate and the phase relationship of its oscillations compared with other metabolites indicate that this activator is not an essential component of the oscillatory mechanism. Further support for this conclusion is the observation of sustained oscillations in both the extracts and a population of intact cells of a mutant strain (YFA) of S. cerevisiae with no detectable fructose 2,6-bisphosphate (less than 5 nM).

Adenosine Monophosphate↗

PubMed1989

Spatial patterns from oscillating microtubules.

Microtubules are fibers of the cytoskeleton involved in the generation of cell shape and motility. They can be highly dynamic and are capable of temporal oscillations in their state of assembly. Solutions of tubulin (the subunit protein of microtubules) and guanosine triphosphate (GTP, the cofactor required for microtubule assembly and oscillations) can generate various dissipative structures. They include traveling waves of microtubule assembly and disassembly as well as polygonal networks. The results imply that cytoskeletal proteins can form dynamic spatial structures by themselves, even in the absence of cellular organizing centers. Thus the microtubule system could serve as a simple model for studying pattern formation by biomolecules in vitro.

Biopolymers↗

PubMed1989

[Transpenile venous occlusion in the treatment of erectile impotence].

In 15 of 18 patients, 2 of them with previous surgery, transpenile venoablation was performed for treatment of erectile dysfunction due to cavernous leakage. In 4 this was combined with retrograde venooclusion via the internal iliac vein. In 4 patients normal erectile status could be obtained. In 3 other patients erections became possible with use of intracavernous vasoactive agents. In two only mild amelioration, and in two others no change of erectile dysfunction were obtained. Follow-up studies are yet missing in 3 patients. Complications of the procedure were not observed.

Adult↗

PubMed1989

Ureterosciatic hernia. A rare cause of pyonephrosis.

A female patient presented as an emergency case with pyonephrosis and septicemia as a result of ureterosciatic hernia. Septicemia was treated successfully by immediate percutaneous nephrostomy tubing. After complete disappearance of symptoms, the hernia was closed operatively. Topographic anatomy of ureterosciatic hernia is presented.

Aged↗

PubMed1988

Distal nephron carcinoma: a rare kidney tumor.

Bellini's duct carcinoma is a very rare tumor originating from the collecting tubules of the kidney. It should be part of differential diagnosis in cases with gross hematuria, failed diagnostic proof of a tumor within the collecting system and a centrally located hypovascular mass. Analysis of the cytoskeleton by means of cytokeratin patterns enables classification as a tumor of urothelial origin.

Carcinoma, Transitional Cell↗

PubMed1988

Castration and erection. An animal study.

Castrated dogs (n = 3) need a much higher threshold level of energy to induce erection by electrical stimulation of the cavernous nerve than noncastrated animals (n = 24). In addition the resulting quality of erection, measured as maximal intracavernous pressure (pCC) versus peak systolic blood pressure (BP), was weaker in castrated dogs (pCC = 57% of BP on average) than in noncastrated dogs (pCC = 80% of BP on average). A high venous outflow from the corpora cavernosa in castrated dogs can also explain the shorter duration of erection. This experimental model excludes the interference of subjective factors, such as erotic stimuli and libido on erection, and it seems that androgen deficiency has a direct effect on the neurophysiology of the erectile tissues resulting in a higher tonus of the detumescence factors, which can be explained by an incomplete relaxation of the sinusoidal smooth muscle.

Androgens↗

PubMed1987

On the recognition of order and disorder.

We compare several algorithms for the recognition of ordered and disordered images. As image sources we use waves of the Belousov-Zhabotinskii reaction coupled to convective motion in a petri dish. This device allows reversibly the generation of periodic (ordered) and aperiodic (disordered) patterns. The best match between the parametric description and the observations is obtained by an "autodifference function". This function is computed by summing up intensity differences over all pairs of picture elements having a given distance on the picture plane. Then, the minimum of this function is determined upon variation of the distance. This algorithm is not only efficient for the recognition of order and disorder in "machine vision", but also plausible in biological visual perception.

Form Perception↗

PubMed1987

[Extracorporeal shockwave lithotripsy of the ureteral calculus--clinical results with local shockwave lithotripsy].

Second generation local shockwave lithotripsy appliances (Lithostar) were used for the treatment of upper and lower ureteral stones in 199 patients, 145 of whom had upper ureteral stones. In 78 patients the calculi were pushed back and all but one disintegrated. In 33 patients a catheter was inserted past the stone, which resulted of primary disintegration in 66%. In 19 of 34 patients (56%) in whom the stones could not be moved, primary disintegration was achieved. Distal ureteral stones were present in 54 patients and these were treated successfully by ESWL alone in 83.3%. Auxiliary measures (total 10%) included ureteroscopy, percutaneous extraction and ureterolithotomy. The results are discussed under the aspects of 'in situ' versus 'push-and-smash' procedures.

Combined Modality Therapy↗

PubMed1986

Two-dimensional spectrophotometry and pseudo-color representation of chemical reaction patterns.

The formation of spatio-temporal patterns in layers of chemical and biochemical media is observed and quantified by a two-dimensional spectrophotometer based on a computerized video equipment with high spatial, temporal, and intensity resolution. Images are shown, to some extent, in pseudo-colors. The use of pseudo-colors and three-dimensional perspective representations enhances the perception of the information contained in an image and the inherent order of the spatial structures.

Chemical Phenomena↗

PubMed1986

Social stress increases [14C]2-deoxyglucose incorporation in three rostral forebrain areas of the young chick.

The 2-deoxyglucose method and EEG-recordings were used to compare forebrain activities between socially reared chicks, one remaining in the group the other being separated with preserved visual and auditory contact. During 30% of the test period, separated chicks produced distress calls and showed a typical EEG arousal pattern. The 9 Hz band of the EEG spectrum and the duration of distress calling were found to be significantly different from grouped chicks. Increased 2-deoxyglucose incorporation were found in 3 rostral forebrain areas of separated chicks, namely the hyperstriatum accessorium/hyperstriatum dorsale, the lateral neostriatum/hyperstriatum ventrale and the medial neostriatum/hyperstriatum ventrale. These same areas were previously reported to increase metabolic activity in imprinted Guinea fowl chicks, when they heared the imprinting stimulus during the 2-deoxyglucose experiment. It is argued that high metabolic activity in these areas reflects arousal and attention to relevant auditory or visual stimuli.

Animals↗