Investigative urology最新文献

Both dried and freshly extracted samples of whewellite stones were examined by light, scanning, and transmission electron microscopy to determine the spatial distribution of the organic (matrix) and inorganic (crystal) phases. The crystalline phase was determined to occur in oriented clusters within which the crystals were stacked with their broad faces parallel. Phase contrast TEM imaging revealed gaps of the order of 100 A between all crystals, and the result of dark field TEM imaging showed that these gaps contain the amorphous phase. Thus, the indications are that the matrix is sandwiched between the crystals and may, therefore, be responsible for cohesion in these stones.

The combination of cyclophosphamide, cis-platinum, and adriamycin has been evaluated in the Nb tumor model system. Triple drug therapy has resulted in marked reduction in tumor volume (P less than 0.01), as well as decreased number of metastases (P less than 0.01). Combination chemotherapy has reduced the metastatic rate, increased complete tumor regression, and reduced the final tumor volume. The androgen insensitive tumor of Nb Pr A.I.-II was evaluated with combinations of BCNU and adriamycin in three cycles. The final tumor volume when compared to controls was significant for all of the agents evaluated (P less than 0.01). A significant decrease in the number of metastases was observed in the triple drug therapy, administered for three cycles, BCNU only, and BCNU and adriamycin. The acid phosphatase content of the treatment group's tumors, when compared to controls was significant with BCNU treatment only.

Ultrastructural examination of the baboon prostate has revealed differences between the caudal and cranial lobes. The cranial epithelium is characterized by electron dense, tall columnar cells which contain numerous secretory vacuoles of homogenous appearance; the caudal epithelium is comparatively shorter in height and lighter in electron opacity. The caudal cells also contain numerous secretory granules which vary in their characteristics. After diethylstilbestrol (DES) treatment (5 mg per day for 3 weeks), the tall caudal cells were reduced to a cuboidal shape; the number of secretory granules in these cells was also markedly reduced. In the cranial lobe, cell height was only moderately reduced, but the secretory vacuoles were decreased both in size and number. In addition, the fibromuscular stroma of the cranial lobe was greatly expanded after DES treatment, with an increased distance between adjoining acini being clearly noted. The systemic effects of DES on the baboons were noted by significantly (P greater than 0.02) elevated levels of serum six hormone binding globulin and significantly reduced serum testosterone levels (P less than 0.01).

Rates of 3H-leucine incorporation into and release from the ventral prostate during castration induced involution were studied in adult male rats. We measured the rate of 3H-leucine incorporation by incubating the prostatic tissue in medium 199 containing 3H-leucine at 37 C for 1 hour. The rate of radioactivity incorporated into the protein fraction was expressed as cpm mg of protein. This rate reduced linearly from Day 0 to Day 6 post castration. Subcutaneous implantation of a silastic capsule containing crystalline testosterone to castrated rats restored the rate of incorporation to that of sham operated rats. To study the rate of 3H-leucine release, 3H-leucine prepared in 0.9 per cent Na C1 solution was injected intravenously into rats 1 day before castration. The amount of radioactivity remaining in the protein fraction of the prostate, expressed as cpm per prostate, was measured at different intervals after castration or after sham operation. Radioactivity disappeared at a significantly faster rate in the prostate of castrated rats than in sham operated controls. Testosterone replacement to castrated rats delayed the rate of loss of radioactivity to a degree similar to that of sham operated rats. These findings indicate that the rapid rate of protein loss in the regressing prostate is the result of a combined action of an accelerated rate of protein degradation and a rate of protein synthesis. Testosterone administration reversed these patterns of protein metabolism.

Oral sodium cellulose phosphate, an inhibitor of intestinal calcium absorption, may reduce urinary magnesium, increase urinary oxalate, and have a limited hypocalciuric action or cause negative calcium balance in the absence of increased calcium absorption or in the presence of renal calcium "leak". To overcome these potential complications, we have taken the following precautions: oral magnesium supplements were given, a moderate oxalate restriction was imposed, a modest dose of sodium cellulose phosphate was used (usually 10 g per day), and only patients with documented absorptive hypercalciuria were treated. During a cumulative treatment period of 42.8 years, 18 patients with recurrent calcium nephrolithiasis showed a sustained reduction in urinary calcium, without developing consistent or substantial reduction in urinary magnesium, hyperoxaluria, hyperparathyroidism, or reduced bone density, Urinary saturation (relative saturation ratio) of calcium oxalate and brushite typically decreased. Remission of stone disease was found in 78 per cent of patients. We conclude that sodium cellulose phosphate is a useful drug for absorptive hypercalciuria when used appropriately.

The intestinal absorption of calcium (Ca), indirectly measured from the calciuric response to oral Ca load (1g), was compared to the more directly obtained isotopic fractional absorption, alpha (from the fecal recovery of orally administered 47Ca). In 17 normal subjects and 30 patients with absorptive hypercalciuria (AH), there was a significant (P less than 0.001) correlation of alpha with the Ca load responses, (r = 0.81). However, this correlation was not observed in patients with renal hypercalciuria (RH), and those with AH receiving thiazide or orthophosphate. In RH, 38 per cent of patients had elevated Ca load responses, despite normal values for alpha. The point correlating the calciuric response and alpha in these patients was below the 95 per cent confidence limit of the line correlating alpha and the load response. Thus, Ca load response often overestimated intestinal Ca absorption, because of the high basal (fasting) urinary Ca. Thiazide therapy in RH improved the correlation between the two tests of Ca absorption. However, thiazide therapy in AH produced normal Ca load responses despite persistently high alpha in 60 per cent of patients. Similarly, 50 per cent of patients with AH receiving orthophosphate had normal Ca load response, although alpha remained elevated. Thus, Ca load response underestimated Ca absorption when patients with AH took thiazide or orthophosphate, probably because these drugs augment renal tubular reabsorption of Ca. These data support the Ca load test as a valid indirect measure of intestinal Ca absorption in normal subjects and patients with AH, in whom fasting urinary Ca is not elevated. In conditions of renal Ca, leak or with various drugs known to alter renal Ca handling, there seen to be large deviations of Ca load response from alpha. Care should be exercised before reaching conclusions regarding the intestinal Ca absorption in these situations.

The nucleation kinetics of calcium oxalate were studied in the presence and absence of sodium urate monohydrate crystalline material by three experimental measurements. These included analytical determinations of calcium and radiotracer analysis of oxalate in the metastable calcium oxalate solution phase and the independent detection of new crystal nuclei by solution turbidity measurements. None of the methods gave any evidence that sodium urate increases the induction time for nucleation of calcium oxalate, in contrast to previously published reports. These results are discussed in relation to the mechanisms advanced to explain the interdependency of hyperuricosuria and calcium oxalate urolithiasis.

Vasoactive intestinal polypeptide (VIP) has previously been shown in nerves of the male and female genitourinary tract, appearing to innervate vascular and nonvascular smooth and epithelial cells. In the present study the concentration of VIP in tissue extracts of different parts of the male genitourinary tract from cat and man was determined by radioimmunoassay. In addition, the effect of VIP on the contractility of the smooth muscle from the cat genitourinary tract was investigated in vitro. The tissue concentrations of VIP were generally higher in cat than in man. In both species high concentrations were found in the vas deferens, bladder, urethra and prostate, In concentration from 3 x 10(-8) to 6 x 10(-7) mol x 1-1, VIP inhibited in a concentration-dependent manner the muscle contractions in specimens from all regions examined, i.e., the vas deferens, ureter, corpus of the bladder, and urethra. The data indicate that VIP might play a physiologic role in the local nervous control of the smooth muscle activity in the male genitourinary tract.