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Biomedical subjects

A Sigel

Publications and source records attributed to A Sigel.

At least 55 records · Page 3Linked to original sources
PubMed1982

[Congenital megaureter and its implications].

Divided into 9 sections, the difficult subject of megaureters is discussed. The classification comprises the primary and the secondary megaureter as well as the less well defined megacystis-megaureter syndrome. An embryopathy of the Wolffian duct and the ureteric buds is the underlying cause. Their main characteristics are obstruction and dysplasia. The primary megaureter develops supravesically. The secondary megaureter, as far as its cause is concerned, starts infravesically and is to be divided into two subgroups, depending on the time the embryopathy is developing. The megaureter, originating in the early embryonal phase is characterized by dysplasia and obstruction. The megaureter, originating in the late embryonal phase, presents obstruction only. The corresponding nephropathy shows obstructive, refluxive and dysplastic features. The causative distal obstruction ascends, its urodynamic reaction, however, descends in accordance with the rules of the pathophysiology of the smooth muscles of cavitary organs. Dilatation of the vesical bladder and the ureter are both prerequisite and symptom of muscular decompensation. The megacystis-megaureter syndrome is felt to be an extreme type of a simple reflux. The infravesical desobstruction is the most important step of the therapeutic strategy, followed by an antireflux ureterocystoneostomy with modellage. The indications are presented. Special types (the ectopic megaureter of a superior renal anlage, the prune-belly syndrome and the megaureter of the neurogenic bladder) are attributed to the classification as described above.

Adult↗
PubMed1982

[Vascular supply preserving repair of megaureter with tailoring in two layers].

Since 1976 we have tapered extremely wide obstructive or refluxive megaureters with partial fibrosis by this new technique, sometimes over 2/3 of length with ureterolysis above. In these cases preserving of the mesoureteric vascular supply is important additional to the regular intramural nutrition. The mesoureteric arteries and veins spread into the adventitia and turn around in curves like a network. An exactly linear resection would damage this. Therefore we remove the adventitia from the lateral side, resect beneath the abundant strip of muscularis with mucosa trimming the megaureter downwards to a diameter of 7 to 4 mm, close the inner layer with running and interlocking 5-0 chromic suture over a splint and then readapt the adventitia. The advantages are: better arterial vascular supply, minimal thrombosis, no necrosis and no urinary leakage, less scarring and therefore good peristalsis.

Child, Preschool↗
PubMed1982

[Sarcoma of the urogenital tract in children].

Motivated by necessity and supported by a review of the literature of the past 8 years and two cases of bladder-prostate sarcoma in our own clinic, the natural history of juvenile urogenital rhabdomyosarcoma is systematically presented, including the changes in therapy in recent years. The paper is organized under the headings etiology, organ distribution, morbidity, morphology, approach to therapy and complications. Pre- and postoperative cytostatic therapy has not only increased the cure rate, but probably also permits, within certain limits and with reservations, organ preserving operations rather than destructive evisceration.

Adolescent↗
PubMed1981

Effects of a cation exchange resin on intestinal calcium absorption and urinary calcium in calcium stone formers.

The effect on the urinary excretion of calcium of an oral cation exchange resin without phosphorus was studied in healthy control subjects and patients with recurrent calcium lithiasis under out-patient conditions. An immediate reduction of intestinal calcium absorption and urinary calcium excretion was found in five control subjects and in one patient after ingestion of resin, whereas calcium excretion remained unchanged in all other patients during long-term treatment. In addition, signs of mild transitory hyperparathyroidism together with an increase in intestinal calcium transport were observed during treatment. It is suggested that intraluminal binding of calcium ions to the resin leads to substantial changes in calcium metabolism with the result that urinary calcium excretion returns to pre-treatment values.

Adult↗
PubMed1981

[Increased quality of the donor kidney due to en bloc binephrectomy (author's transl)].

The en bloc removal of both cadaver kidneys, approached transperitoneally, offers the following advantages in comparison with the separate bilateral technique: 1. Easy exposure of the renal artery and vein, even in the case of multiple renal vessels. -- 2. A venous and arterial patch of sufficient size is always available, facilitating the vascular anastomosis and reducing risk of vascular stenosis. -- 3. Damage due to ischemia is avoided or minimized by means of intraoperative perfusion. -- 4. Damage to the intima of the renal artery is avoided inasmuch the aorta instead of the renal artery is perfused. -- 5. Whenever a longterm perfusion by machine is considered, a rapidly constructed aortic conduit helps to avoid a potential damage to the intima of the renal artery by direct cannulation. -- 6. Separate mediocolonic removal of either kidney yields comparable results except the risk of damage to the intima. -- 7. A modification of the method is indicated, when both pancreas and kidneys are to be removed.

Cadaver↗
PubMed1981

[Urological relevance of pelvic fractures].

1. Apparently it is the anatomical difference of the paravesical structures which determines, whether a pelvic fracture will result in urological complications or not. The more the urogenital diaphragm is involved, the less is the risk of urological complications. The type of pelvic fracture and the magnitude of the trauma are of minor importance. 2. With respect to pathology and typology, one has to differentiate between incomplete and complete disruption of the urethra. The more pronounced the rupture is, the more the distal stump will retract back into the injured urogenital diaphragm. The longitudinal rupture splits the anterior wall of the urinary bladder and prostate; the rupture may extend into the membranaceous urethra. 3. Bleeding from the urethral meatus and the endogenous cystogram yield the most to the diagnosis of urological complications of a pelvic fracture. 4. The therapy is twofold. In the case of complete urethral disruption and dehiscence of the bony fragments, operative transvesical atraumatic splinting of the urethra by means of a Foley catheter is indicated. In the case of incomplete urethral rupture, transurethral insertion of a Foley catheter is usually sufficient and successful. 5. The results of the various therapeutical approaches equal the original extent of the urological complication. In addition to a certain degree of posttraumatic urethral stricturing, there are five further well defined sequelae of late urethral injuries.

Humans↗
PubMed1980

[Urolithiasis - a review of pathophysiology, diagnostic procedures and therapy (author's transl)].

The present state of knowledge of the pathophysiology of urolithiasis and the assignment to subgroups according to varying aetiology is outlined. In addition, a diagnostic programme is insight proposed which has proved of value in ambulatory patients attending specialist departments. It permits into the underlying disturbances and may be considered a prerequisite for effective treatment. It is suggested that this general scheme of clinical investigation is a reasonable basis to the medical care of patients with urinary calculi.

Anti-Bacterial Agents↗
PubMed1980

[Effective treatment of urolithiasis requires metabolic classification (author's transl)].

A diagnostic program for the metabolic classification of urolithiasis is proposed on the basis of pathophysiologic mechanisms. It allows categorization of patients in various subgroups, which is a prerequisite for the different regimens of non-surgical treatment. The characteristic clinical and biochemical features underlying this classification are outlined.

Calcium↗
PubMed1979

Composition of renal stones and their frequency in a stone clinic: relationship to parameters of mineral metabolism in serum and urine.

Stone analyses (kidney, upper urinary tract) of the department of Urology, University of Erlangen, from a four-year-period (1974-1977) have been recorded with emphasis to stone composition, sex and age of the pertinent stone forming patients. During this time period there were no substantial changes as regards the per cent frequency of the various stone types. The most frequent type was calcium oxalate (CaOx), followed by uric acid, calcium phosphate (CaP), struvite and cystine. Stone analyses were mostly requested for patients between 46 and 55 years of age. Stone incidence in our clinic is calculated to be 1.22 times higher in males than females, especially beyond 36 years of age. The frequency peaks are: pure (= 100 per cent) CaOx 36-45 years; CaOx with additional mineral phases (mostly CaP) 46-55 years; uric acid 56-65 years; CaP 26-35 years. From those patients who underwent further investigations in searching for metabolic abnormalities serum concentrations, urine mineral clearances in fasting urine samples, and activity products of stone forming mineral phases in sequentially collected specimens from 24 h and 2 h fasting urine had been measured and compared with values from healthy control subjects. In urolithiasis (idiopathic) there is a normal parathyroid hormone blood level, a generally lower serum inorganic phosphate and magnesium concentration. In pure (= 100 per cent) CaOx and uric acid lithiasis serum uric acid and creatinine are higher than in controls, urine pH and calcium clearance in some groups are different too. Clearances of magnesium, uric acid, phosphate, sodium are within normal limits in urolithiasis. When expressing the propensity to form stones in terms of activity products, then only uric acid lithiasis deviates substantially from normal. All other stone types differ only slightly or not at all from each other and controls respectively. It is concluded that 1) in our geographic region the various stone types prevail in different age periods; 2) there are distinct alterations of parameters of mineral metabolism in urolithiasis; 3) measuring urine clearances may lead to assume falsely normal mean urine excretion of stone forming constituents.

Adolescent↗
PubMed1979

[Desobstructive sodium and water diuresis: pathophysiologic and clinical aspects of bilateral obstructive nephropathy (author's transl)].

The measurement of sodium and water loss after relieve of the obstruction shows that the obstructive nephropathy originates in three pathogenetic mechanisms. (1) Acute complete bilateral ureteric obstruction causes tubular atrophy, prevents both resorption and glomerular filtration, reduces the renal blood flow and increases the extracellular space by retention of water and products subject to urinary excretion. (2) Relieve of obstruction results in excess polyuria as blood flow and glomerular filtration recover rapidly, the extracellular space gets rid of its osmotic load, and the tubular dysfunction of resorption continues for several days until the epithelium has recovered from its pressure atrophy. All this will result in a high loss of sodium and water which requires adequate substitution; otherwise, natriuretic shock will result. (3) The chronic (bilateral) obstruction behaves in a similar way, yet is less reversible. The tubular damage is the same. Moderate polyuria occurs already during the stage of obstruction. Hereby the extracellular space decreases. After relieve of the obstruction the polyuria increases significantly, yet less rapidly than after acute obstruction as the glomerular function does not recover completely. The renal blood flow remains diminished, the vascular calibers stay narrowed, and the kidney remains shrunken. Loss of sodium and water will endanger the patient with chronic obstruction. Furthermore, the patient will be at risk due to dehydration, acidosis, anemia and uremia. The infusion therapy of the desobstructive nephropathy syndrome is based upon the venous pressure and the serum electrolytes which are measured twice daily.

Adult↗
PubMed1979

Citrate in daily and fasting urine: results of controls, patients with recurrent idiopathic calcium urolithiasis, and primary hyperparathyroidism.

In three groups--patients with recurrent calcium urolithiasis (RCU), patients with primary hyperparathyroidism (pHPT), and healthy controls--citrate was measured enzymatically in 24 and in 2-hr urine after an overnight fast. Citrate excretion per 24 hr was significantly lower in RCU than in age and sex matched controls, whereas there was no significant difference in citrate excretion in urines from the 2-hr morning collection. In pHPT citrate was also lower than in controls and fell within the range of RCU of comparable age. Both categories of urines (24 and 2hr) have in common the characteristic that the actual citrate concentration is lower by 50 per cent in RCU and pHPT than in controls, mainly as a result of the higher urine volume. Correction of citrate for creatinine does not disclose further differences among the populations studied but conversely hampers exact interpretation of urinary citrate in the absence of strict separation of individuals according to sex and age. From these data we conclude that (i) a low excretion and concentration of urinary citrate is detectable in calcium lithiasis and may contribute to a deficiency in inhibitory activity against nucleating processes in stone-forming urine; and (ii) the differences in urinary citrate elicited in samples of 24 and 2-hr morning urine are of unknown origin and merit further investigations.

Adult↗
PubMed1978

[Transvenous perfusion, a new simple and effective technique of regional renal hypothermia. An experimental study (author's transl)].

In an experimental study, involving ten dogs, the feasibility of transvenous perfusion cooling of the kidney is proven. The theoretical basis of this new method of regional renal hypothermia is presented. The technique is easy to perform and requires cannulation of the renal vein. The perfusate leaves the kidney either via the capsular veins which were divided during renal exposure or through the proposed nephrotomy. Renal vein thrombosis or venous disruption have not been observed. The only complication encountered in one instance was hemorrhage from the puncture site of the renal vein.

Animals↗
PubMed1978

[Evaluation of renal cyclic adenosine monophosphate, serum parathyroid hormone and phosphate reabsorption in recurrent calcium urolithiasis, healthy controls and hyperparathyroidism (author's transl)].

In three groups (n = 12 each) of male controls (22--43 years), patients with recurring calcium urolithiasis (21--36 years) and hyperparathyroidism (HPT; 17--71 years) proven by surgery renal cyclic adenosine monophosphate (RcAMP), fractional tubular phosphate reabsorption and serum parathyroid hormone (PTH) were measured during endogenous creatinine clearance. RcAMP (muMol/g creatinine) was: controls 1.48 +/- SEM 0.27; stone formers 2.037 +/- 0.343 (not significantly different); HPT 6.234 +/- 0.454 (p less than 0.001). There is no overlap between HPT and controls. Phosphate reabsorption is least in HPT (0.84 +/- 0.015), higher in controls (0.924 +/- 0.004) and stone formers (0.941 +/- 0.007). All differences are statistically significant. Under the conditions selected (moderate hydration of individuals) Serum PHT (pg-equiv/ml) is lowest in stome formers (less than 100--339), higher in controls (less than 100--933) and HPT (400--1150). there is no overlap in PHT between the former and the latter group but a marked one between controls and HPT. For clinical purposes the resulting diagnostic uncertainty in a given patient can be overcome by additional determinations of RcAMP and ionised serum calcium: when referring to serum PTH HPT patients fall outside, RCU patients within 2 standard deviations of either parameter in control subjects. This procedure presently appears superior to those proposed in the past (urinary cAMP etc.) but requires confirmation in larger patient populations. Moreover, since HPT prevails in middle and upper age decades, their RcAMP values and those of RCU patients should be related to a range seen in closely age- and sex-matched controls.

Adult↗
PubMed1978

Technique and results of the colonic conduit, continent by means of a new magnetic stoma seal an experimental study.

On the basis of satisfactory results with a new magnetic stoma seal in colostomy patients this seal, consisting of a magnetic ring and cap, was used in an experimental study to convert the colonic conduit into a continent reservoir. Complete continence was obtained in all of the 12 animals which survived the operation. All rings were well accepted by the tissue when the procedure was staged by implanting the ring transperitoneally several weeks prior to fashioning of the conduit. Residual urine was low, owing to an ideal energy-balance pattern. Coloureteric reflux was successfully prevented in all cases where a long-tunnel-modification of the Leadbetter-Clarke technique was used. Hyperchloraemic acidosis and deterioration in renal function were not observed. All conduits were infected.

Animals↗
PubMed1978

[The cancerologically correct operation for nephroblastoma (author's transl)].

The following methodology is suitable for increasing the radicality of and the safety of the vessels during a transperitoneal operation for nephroblastoma and simultaneously for sparing the necessity of postoperative radiation: 1. primary exposure of the renal vascular cross, the vena cava, and the aorta through incision of the plica duodeno jejunalis together with mobilization of the duodenum to the right, the mesocolon to the left; 2. primary ligature of the a. renalis in front of the v. renalis (no problems on either side); 3. systematic retroperitoneal en bloc lymphodissection from the a. mesenterica superior to the forking of the aorta, laterally to the diaphragm, probative at the adnexa; 4. subsequent lateral release of the left-sided tumorous kidney, medial release of the right-sided tumorous kidney after mobilization of the cecum.

Humans↗