Investigative urology最新文献

Ten kidney tumors conforming to nephroblastoma were encountered during a 10-year period in a closed colony of Nb hooded rats. Histologic examination of the primary neoplasms, and of a limited number of transplanted derivatives, indicates that spontaneous nephroblastoma in the rat is exclusively an epithelial neoplasm, consisting of dense aggregates of undifferentiated, basophilic blast cells set in a connective tissue stroma of benign character. This uniform entity should be clearly distinguished from renal mesenchymal tumor, a connective tissue neoplasm of heterogeneous form which is induced frequently in rats by certain chemical carcinogens.

We made corrosion casts of the testicular vessels in rats and humans and investigated their architecture by scanning electron microscopy. Two types of capillaries, intertubular and peritubular, were clearly demonstrated in the rat testis; the former formed a dense network with a polyhedral shape and the latter had a rope-ladder-like appearance. The architecture of the human testis was very complicated; the intertubular capillaries formed either no clear capillary network or a very loose one. The peritubular capillaries did not show a rope-ladder-like appearance.

Twenty-six patients with carcinoma of the prostate were allocated to treatment by subcapsular orchidectomy, estrogen administration, or cyproterone acetate administration. Tissue fibrinolytic activity in skin biopsy specimens was estimated by a histochemical method before treatment was initiated and 2 and 8 weeks later. Orchidectomy caused no significant changes in the fibrinolytic activity. During estrogen therapy the fibrinolytic activity in skin was significantly reduced at 8 weeks. In the group given cyproterone acetate the activity was significantly increased at 8 weeks. In the group given cyproterone acetate the activity was significantly increased at 8 weeks. The reduction in fibrinolytic activity in skin could contribute to the increased risk of thromboembolism during estrogen treatment of patients with cancer of the prostate.

Previous experimental investigations of embryonic kidney development with in vitro organ culture techniques have been limited by the short duration of explant viability. Utilization of chick chorioallantoic membranes for transplanting undifferentiated murine kidney rudiments has allowed vascularization of the grafts with advanced maturation and the appearance of early nephron units.

We examined epitactic relationships between hydroxyapatite (HAP) and the hydrates of calcium oxalate from a crystallographic point of view. We also examined the growth of HAP on the calcium oxalate surfaces at a constant supersaturation, we maintained by the controlled addition of solutions containing the lattice ions of the precipitating phase. Calcium oxalate trihydrate was the only salt that induced HAP overgrowth. The latter phase, however, was found to be a suitable substrate for the growth of calcium oxalate monohydrate.

The growth and aggregation of calcium oxalate seed crystals in a metastable solution of this salt were assessed separately by using the Coulter counter to measure the net increase in total crystal volume and the percentage change in total crystal number respectively. The value of assessing crystal growth and aggregation in these terms was shown by using these parameters to measure the inhibitory effect of a normal human urine. Independent assessment of growth and aggregation enabled a more accurate interpretation of experimental events than was possible by considering the two processes in combination. The method therefore has the potential of improving the discrimination between the inhibitory activities of different urines.

We used an in vitro model to investigate Escherichia coli attachment to transitional epithelial cells obtained from bladders of female rats. Adhesive abilities and sensitivity to mannose inhibition differed among the isolates for both epithelial cells and erythrocytes. Adherence of some strains could be modulated by bacterial washes and growth media. Variations in adhesiveness were related to bacterial piliation as determined by transmission electron microscopy. With two strains, mannose inhibition of adherence to epithelial cells was dose-related; however, with a maximal inhibitory dose, adherence was reduced by approximately 80 per cent even when the bacteria-to-epithelial cell ratio was varied. These studies show that adhesiveness and piliation of certain adhesive E. coli strains are either reduced or enhanced by environmental alterations. We conclude that E. coli strains adhere to epithelial cells by at least two distinct mechanisms and that a single isolate may utilize both mechanisms. The more efficient process is pili-mediated and inhibited by mannose whereas undetermined surface components mediate the less efficient but mannose-resistant mechanism.

Lewis rat recipients of Brown Norway (BN) and Dark Agouti (DA) kidneys were tested for enhanced survival after they were injected with various immunogens. Lewis recipients of BN kidneys injected with either BN whole blood, bone marrow cells, red blood cells, or DA whole blood had enhanced survival. Lewis recipients of BN kidneys injected with either BN plasma or BN thymocytes did not have enhanced survival. Lewis recipients of DN kidneys injected with DA blood had enhanced survival. Lymphocytotoxins were found infrequently in recipients with rejected renal allografts. Active enhancement of the rat renal graft may be produced by immunization with cells that express serum determined or cell determined antigens.

We used a simple theoretical model to stimulate the changes in particle size distribution that occur when crystals grow, or disaggregate to a defined extent. The change in total particle volume was used as an index of growth, whereas aggregation and disaggregation were expressed as the change in total particle number. Indices of inhibition of growth and of aggregation in hypothetical test cases were calculated in relation to a control and compared with the inhibition index derived by the standard method of comparing the distribution of particle volume around a given arbitrary diameter on the particle distribution curve. We concluded that the expression of particle growth and aggregation in terms of total volume and number respectively is a preferable alternative to the standard technique.

We investigated the effect of tissue and urine concentrations of ampicillin and mecillinam on bacterial bladder wall adherence in rats. Escherichia coli 02 labeled with 3H-1-leucine was inoculated into the bladder for 2 hr. With the ureters transected bilaterally, antibiotic was instilled into the bladder lumen or administered intravenously only. No bacteria survived after the presence of antibiotic in the bladder lumen for 1.5 hr. After intravenous administration of ampicillin, with no antibiotic in the bladder lumen, measured by viable counts, decreased significantly as compared to controls. Adherence, measured by radioactive counts, decreased significantly after intravenous administration of mecillinam, possibly indicating prevention of tissue invasion. This finding was explained by entrapment of bacterial debris in the bladder lumen and invasion of bacteria into the bladder wall. Our results support the importance of tissue concentrations in the treatment of urinary tract infections.