Investigative urology最新文献

We determined quantitative nucleation and growth kinetics of calcium oxalate in the presence of various combinations of urine constituents, using a continuous mixed suspension mixed product removal crystallizer and a Coulter counter. Nucleation rates of calcium oxalate from the pure component system were approximately an order of magnitude higher than those from an artificial urine. The presence of citrate inhibited nucleation rates under high conditions. The ions Na+, K+, NH4+, Cl-, and SO42- did not affect the overall kinetics in the synthetic urine. Di- and tri-hydrate products were formed, except when crystallizing from pure components, when only the thermodynamically stable monohydrate was observed.

Histologic preparations of the urethras of 3 and 30-month-old virgin female C57 mice were stereologically analyzed with a light microscope with an eyepiece grid. Serial sections of entire urethras were stained and divided into ten representative regions; the component tissues of each region were analyzed. There was no significant change with age in the total muscle component in each region. The muscle, however, was divided into two types: muscle with and muscle without the infiltration of collagen fibers. The amount of muscle with collagen infiltration was significantly increased in some regions of the urethra in the 30-month-old group. There was no age-associated significant difference in the vascular or connective tissue components of the urethra. A difference in the glandular component was recorded in one region only, because of change in the ducts of the clitoral glands. We noted differences in the lumen and its epithelium that were attributable to the more open urethral lumen in the young group in certain regions.

The treatment of castrate beagles with a combination of estradiol an dihydrotestosterone (DHT) results in the synergistic enhancement of prostatic growth and the experimental induction of benign prostatic hyperplasia. This estradiol synergism can be shown as a greater than 3 fold increase in both prostatic wet weight and total DNA content in castrate dogs treated with both steroids, as compared to those animals treated with DHT alone. In direct contrast to the situation in the dog, there was no evidence of estradiol synergism on prostatic growth when castrate rats were treated with combinations of estradiol and DHT, even if both the ratio and absolute amount of both steroids were experimentally varied over a wide range of values. Regardless of the ratio or absolute dose, estradiol was completely unable to synergize the DHT induced growth of the prostate as well as other sex accessory tissues of the castrate rat. This indicates a fundamental difference between the rat and dog in regard to prostatic growth response to combinations of estradiol and DHT treatment.

Physiologic studies were carried out on 51 anesthetized cats. We monitored contraction and relaxation with force displacement transducers, recording individually from bladder, longitudinal, and circular urethral smooth muscle layers; and intravesical pressure with a pressure transducer. During constant slow vesical filling with warm saline the urethral muscle tone, without increased motility, was capable of maintaining continence. At the prevoiding stage, the circular urethral muscle contracted and the longitudinal relaxed for 1 to 2 sec, which tightened the bladder neck and resulted in the creation of isovolumetric bladder pressure stage. The voiding was accomplished by bladder pressure augmentation, bladder muscle contraction, and synergic contraction of longitudinal and relaxation of circular urethral muscles. A transient urethral pressure drop preceded the urethral pressure rise of the isovolumetric stage of voiding. The smooth urethral muscle motility pattern during voiding was reproduced without fluid flow per urethrum by the inflation of a balloon in the bladder.

Cytosolic and nuclear androgen receptor levels were determined in dog prostates after castration and after treatment with steroids. The cytosolic androgen receptor levels 1, 5, and 13 days after castration were reduced to 32, 47, and 34 per cent of intact dog levels. We also initiated steroid treatments immediately after castration. The administration three times weekly of either dihydrotestosterone, 5 alpha-androstane-2 alpha, 17 beta-diol (3 alpha-diol), or of a combination of 3 alpha-diol and estradiol resulted after 13 days in a 2 fold increase of cytosolic androgen receptors relative to intact untreated dogs. Androgen receptor levels in 0.5 M KCl nuclear extracts were significantly (P less than 0.01) increased in spontaneously hyperplastic prostates relative to normal prostates. They were also significantly (P less than 0.05) increased in dogs treated with either dihydrotestosterone, 3 alpha-diol, or with a combination of 3 alpha-diol and estradiol but were highly depressed after castration. These results suggest that experimental prostatic hyperplasia produced by the injection of androgens probably occurs via increased androgen receptor levels.

Employing technetium labeled dimercaptosuccinic acid, we predicted the inulin and p-aminohippuric acid (PAH) clearances after recovery of an obstructed kidney before relief of the obstruction. Sixteen rabbits had one renal unit obstructed for varying period of time. The animals were scanned immediately before relief of the obstruction. After 4 to 6 months recovery, inulin and PAH clearances were measured in all animals. The scans were mathematically analyzed, and accurately predicted the inulin and PAH clearances obtained after complete recovery (P less than 0.001 and P less than 0.001, respectively). Six rabbits were scanned at the time of the clearance measurements. By a different mathematical analysis, inulin and PAH clearance measured concurrently correlated with the scan (P less than 0.001 and P less than 0.01 respectively).

We evaluated the effect of treatment of patients with prostatic cancer with estramustine phosphate or the combination diethylstilbestrol-polyestradiol phosphate on the natural killer cell activity in peripheral blood. Although estramustine phosphate did not affect natural killer cell activity, diethylstilbestrol-polyestradiol phosphate substantially reduced natural killing after a treatment period of 1 week. The activity was only slightly further lowered after 4 weeks of treatment. Possible clinical implications of the difference in susceptibility of natural killer cells to these agents are discussed.

The standardization of a stretching technique for bladder strips was carried out as a step towards its clinical use. Six variables were studied on specimens of prefrozen bladders taken from human cadavers. Repeated elongations change the nature of the muscle. Viscoelastic coefficients of mucosa are markedly higher than those of muscle. It is necessary to study specimens that have essentially the same direction of fibers and that are located in the same portion of the bladder. The thickness of the specimen does not affect coefficients significantly. The percentage of muscular elongation, in relationship to specimen length, should not exceed 20 per cent in order to have linear reproducible results.

We studied calcium oxalate stone formation in rats in which calculogenesis was induced by a diet deficient in pyridoxine (vitamin B6). We studied the sequence of stone formation using both a gross specimen transillumination technique, which is described, and histologic methods. A characteristic regional distribution of calculi is described and illustrated. Histologic studies reveal the interstitial site of calcium oxalate microlith formation. The progressive movement of these crystals through the tubular wall into the tubular lumen is described and illustrated. The formation of Randall's plaques is described and illustrated, as is a characteristic "geode" formation in the calyceal fornix. The significance of these findings is discussed and a new concept of stone formation proposed.