Search PubMed⌕ Search

Biomedical subjects

Iu A Pytel'

Publications and source records attributed to Iu A Pytel'.

At least 91 records · Page 5Linked to original sources

[Role of electrochemical potential in urinary tract function].

Rhythmic changes produced by impulse waves, respiratory and other movements are able to convert mechanical energy of the urine in the pelvis to electric energy because urine is a high-concentration electrolyte. With filling and extension of the pelvic wall, when epithelial coating is transforming from multilayer to one-layer, its resistance to electric current lowers. Growing pelvic volume in the course of the pelvis filling is accompanied by increasing electrical potential in the pelvic wall in parallel with a decline in urothelial resistance. Accumulation of electrochemical potential in the submucous layer and interstitial intermuscular spaces is a powerful stimulator of the neuromuscular elements of the urinary tracts. Their rhythmic engagement is controlled by baroreceptor pelvic mechanisms and distal urinary tracts. Such a pace-maker is functional. It does not need special morphological structures, as its activity is determined by electrochemical potential accumulated rhythmically in the wall. This potential depends on composition and properties of the urine which are related to renal functions and homeostasis.

Action Potentials↗

[Mineral water Volzhanka from Undorovskĭ spring in combined therapy of patients with nephrolithiasis and chronic pyelonephritis].

Water loading is an essential component in therapy of nephrolithiasis, especially in the presence of small ureteral concrements or fragments after extracorporeal shock-wave lithotripsy. Saluretics, furosemide in particular, cause side effects. One of these is dyselectrolytemia due to potassium loss. Mineral waters have advantages in the treatment of nephrolithiasis and pyelonephritis as their drinking does not lead to electrolyte loss. Low mineral waters are highly diuretic, e.g. after drinking 1 liter of Volzhanka day-time diuresis increases by 300-400 ml. This relieves ureteral and calyceal-pelvic tonicity stimulating elimination of the concrements or their fragments after lithotripsy. Intake of Volzhanka proved effective in combined therapy of nephrolithiasis, calculous pyelonephritis, urate nephrolithiasis.

Chronic Disease↗

[The selection of the treatment method in stenosis of the pelviureteral segment in nephrolithiasis].

Ureteropelvic stenoses in nephrolithiasis are suggested to be considered reversible and irreversible depending on the lesions of the upper urinary tracts and the adjacent fat. To ascertain reversibility of the stenosis, use was made of the progesterone test in view of progesterone ability to dilate the ureter. No retention changes in the upper urinary tract in the reversible stenosis can serve an indication to impulse lithotripsy. Large stones and all cases of irreversible stenosis indicate validity of open surgery the scope of which is decided intraoperatively after isolation of the ureteropelvic segment from the periureteral fat and upon the indigo carmine test. In the absence of dysfunctional zone in the segment the patients may be subjected to ureterolysis and pyelolithotomy. If such zone is detected it is possible to make pelvic and proximal ureteral resection, pyeloureterostomy. The technique of the latter surgery in the intrarenal pelvis is detailed.

Constriction, Pathologic↗

[The muscle compressing the ureter and its role in the closure mechanism of the ureteral-bladder segment].

The authors indicate an important role of the locking mechanism of the vesicoureteral segment in the prevention of the retrograde regurgitation of urine into the upper urinary tracts, namely vesicoureteral reflux. They pay special attention to the fact that the knowledge of the structure of the terminal part of the ureter helps select certain appliances preventing the development of the reflux. However, the known data fail to satisfy the clinicians and explain the appearance of the reflux in some cases. Therefore, the authors have undertaken an original morphological investigation of the terminal part of the ureter, observing the vesicoureteral complexes of 32 human cadavers. Micropreparation of the vesicoureteral segments was performed with the use of a 2.5-4X binocular magnifier. The study revealed a muscle previously undepicted. Regarding it as the ureter-pressing one, the authors designated it as "musculus appressor ureteris". Formed by the muscular fibres of the detrusor and situated 1-2 cm more proximal than the ostium ureteris, it arches through the submucosal segment of the ureter and is connected with the musculature of the urinary bladder on the both sides of the ureter. Its width is about 6-8 mm and its thickness is 1.5-2 mm. The authors explain its function and role by the locking system of the vesicoureteral segment, which is proved by the development of the reflux in case the ureteral ostium and the above muscle are dissected. The authors emphasize the fact that it is necessary to extremely accurately cut the anterior wall of the terminal part of the ureter.

Humans↗