Cajal-like cells in the human upper urinary tract

PURPOSE: Interstitial cells of Cajal (ICCs) have an important role in the regulation of gut motility as they are responsible for the slow wave activity of smooth muscle. It is still unknown if ICCs also occur in the human upper urinary tract. Since these cells express and are marked by the c-kit receptor CD117, we investigated its occurrence and distribution along the human upper urinary tract. MATERIALS AND METHODS: Tissues from 56 human ureters, spanning proximal, middle and distal ureter segments, were analyzed by indirect immunohistochemistry using the alkaline phosphatase-anti-alkaline phosphatase method and double labeling immunofluorescence on consecutive tissue sections. Several monoclonal and polyclonal antibodies to c-kit receptor were used in combination with various cell markers for histiocytic, mast cell, endothelial, epithelial, neuronal, smooth muscle and stem cell differentiation. RESULTS: The c-kit receptor was found in 3 cell types of the ureter and in round or spindle-shaped cells. Due to their antigenic profile the first one was revealed as mast cells occurring in all layers of the ureteral wall except the urothelium. In contrast, the population of spindle-shaped cells was only marked by c-kit receptor, thus, resembling ICCs. These ICC-like cells were found among the inner and outer smooth muscle layers, and in the lamina propria. They showed a slight decrease from proximal to distal ureteral segments. However, unlike intestinal ICCs their cytomorphology differed and some cells, representing the third group of c-kit receptor positive cells, were found within the urothelium. CONCLUSIONS: Our data demonstrate the presence of ICC-like cells and their ubiquitous distribution in the human ureter. The physiological importance and pathological significance of these findings must be evaluated by functional studies and investigations of certain pathological with urinary outflow disturbance conditions.     

Duplication of the upper urinary tract.

The possibility of ureteric duplication should always be considered in children presenting with urinary infection. A high degree of suspicion should be present during X-ray investigation. Surgery is nearly always required to cure the problem, vesicoureteric reflux requiring reimplantation and a ureterocoele involving both uncapping and reimplantation techniques. Heminephroureterectomy is rarely required except in cases of bizarre ectopic opening in which incontinence is the presenting feature and the associated renal segment is dysplastic. Ureteropyelostomy is required for the rare situation of saddle reflux in the bifid ureter of incomplete duplication. It is occasionally employed for complete duplication, but it must be stressed that the primary defect is always at the lower end of the ureter and such bypass surgery must be combined with a ureterectomy and, when necessary, reimplantation of the remaining ureters.     

Cholesteatoma of the upper urinary tract

We report the case of a 57-year old patient with complex cystic image in right kidney. Following radical nephrectomy, the pathological study established the diagnosis of renal cholesteatoma. We discuss the frequency, pathogenesis, clinical presentation, propedeutics, histological findings and proposes for intervention observed in the literature.     

Endoscopic management of upper urinary tract stones.

In a two year period from March 1983, 157 patients with upper urinary tract stones were managed primarily by endoscopy. Of 90 patients with renal stones, extraction was achieved in 91% of patients with complete extraction in 76%. Of the remaining patients with ureteric stones, successful extraction was achieved in 75%. Ten patients required open surgery which was for failed extraction in 9. Morbidity is low with a mean hospital stay of 4.7 days for patients with kidney stones, and of 3.7 days for patients undergoing extraction of ureteric stones.     

Obstruction of the upper and lower urinary tract

Obstruction of the urinary tract can occur at any point from the calyces to the external urethral meatus. Obstruction within the urinary tract is best divided into upper tract and lower tract obstruction. Obstruction can be acute or chronic. Acute upper tract obstruction is most commonly due to a calculus and acute lower tract obstruction in men is often due to benign prostatic enlargement. Chronic upper tract obstruction in the Western world is most commonly due to calculi or pelvi-ureteric junction obstruction. Chronic lower tract obstruction in men will again be due to benign prostatic enlargement in a majority of cases.     

Dynamics of the ureterovesical junction: its resistance to upper urinary tract outflow in pigs

In pigs, upper urinary tract outflow resistance at the ureterovesical junction (UVJ) has been investigated before and after changes of capacity and compliance of the bladder with ureterovesical perfusion pressure (UV-PP) measurements and cystometry (PB). Changes of UV-PP approximately paralleled changes of PB during volume changes and compression of the bladder, and during detrusor activity. Exceptions were: detrusor activity in all bladders, being nondistended, during which UV-PP always increased more than PB; and low and high compliant, and small capacity bladders in which UV-PP may change more than PB under all conditions once these bladders are so far filled that they are distended. From these findings and UVJ anatomy it is concluded that, besides intravesical pressure, anatomical factors and forces in the bladder wall also may determine upper urinary tract outflow resistance. The clinical implications are discussed.     

Obstruction of the upper and lower urinary tract

Obstruction of the urinary tract in the adult can occur at any point from the calyces to the external urethral meatus. Obstruction within the urinary tract is best divided into upper tract and lower tract obstruction and obstruction can be acute or chronic. Acute upper tract obstruction is most commonly due to a calculus and acute lower tract obstruction in men is often due to benign prostatic enlargement. Chronic upper tract obstruction in the Western world is most commonly due to calculi or pelvi-ureteric junction obstruction. Chronic lower tract obstruction in men will again be due to benign prostatic enlargement in a majority of cases.