[A clinical study of renal pelvic and ureteral cancer: prognosis and frequency of subsequent bladder cancer following surgical treatment].

PURPOSE: A retrospective investigation of patients presenting with renal pelvic and ureteral cancer was performed. This study focused on the prognostic factors and frequency of subsequent bladder cancer following surgical treatment. MATERIALS AND METHODS: Forty-five patients presenting with transitional cell carcinoma, who had undergone nephroureterectomy at the Department of Urology, Okayama Central Hospital, from March 1990 to November 2000, were reviewed. Various factors were evaluated according to survival and non-bladder cancer occurrence rates. The Kaplan-Meier method was used in the analyses. RESULTS: Patients consisted of 33 males and 12 females (mean age was 71.7). Seventeen patients exhibited renal pelvic cancer, 25 cases displayed ureteral cancer and three subjects presented with multiple cancers. Eleven patients had received treatment for precedent or coexistent superficial bladder cancer by transurethral resection. The overall 5-year survival rate was 71.9%. Ten patients died as a result of the disease; in all cases, lymph node or distant metastasis had progressed. Pathological T factor, tumor grade and pN factor demonstrated a significant effect on survival; however, sex, age, tumor localization and incidence of subsequent bladder cancer had no influence on survival. The 5-year non-bladder cancer occurrence rate was 38.8%; additionally, all subsequent bladder cancer was disclosed within three years. Tumor multiplicity exclusively in the upper urinary tract significantly affected occurrence of bladder cancer. T factor and tumor grade revealed no correlation to occurrence. CONCLUSIONS: Adjuvant chemotherapy for prevention of clinical metastasis should be considered in cases involving pT3 or higher stage, grade 3, or in instances of pathologically confirmed lymph node metastasis. The significant occurrence of subsequent bladder cancer in the case of tumor multiplicity suggested that prophylactic therapy such as intravesical BCG instillation or chemotherapy might be beneficial.

Localization of dynamin 2 in rat seminiferous tubules during the spermatogenic cycle.

Dynamin is a protein essential to endocytosis. Dynamin 2, a dynamin isoform, is expressed most intensely in testicular tissue; however, precise localization has never been studied. Therefore, we investigated the expression of dynamin 2 in rat testicular tissue using immunohistochemical methods, and discuss here the physiological function of this protein. Testicular tissues were obtained from Wistar rats at 10, 21 and 63 days of age. Immunohistochemistrical examination and Western blot analysis were conducted using dynamin 2 specific antibody. Western blot analysis showed that expression in 21- and 63-day-old rats was more intense than that in 10-day-old rats. Dynamin 2 expression was observed using immunohistochemical method in the seminiferous tubules of all rats. In the 63-day-old rats, the expression was intense, especially in spermatids in the earlier maturation stages and in spermatocytes, and was observed in Sertoli cells. However, in spermatids, the expression gradually declined as spermatids matured to spermatozoa. In the 21-day-old rats, the expression was evident in spermatocytes and Sertoli cells, but that in the 10-day-old rats was weak. Intense expression of dynamin 2 during spermatogenesis suggests that this protein plays an important role in this process.

Distribution of dynamins in testis and their possible relation to spermatogenesis.

Dynamin 2 and dynamin 3 are highly expressed in testis. However, their functions in the tissue remain unclear. Considering that dynamin 1, neuron-specific isoform of dynamin, plays a pivotal role in endocytosis, functions of dynamin 2 and dynamin 3 in testis must be essential. Cellular expression and subcellular localization of dynamin 2 and dynamin 3 in testis were investigated. Dynamin 2 and dynamin 3 were highly expressed in germ cells and Sertoli cells, constituents of seminiferous tubules. By immunofluorescence it was revealed that dynamin 2 colocalizes with clathrin both at the plasmamembrane and at Golgi in a cell line of Sertoli cells. Immunoreactivity for dynamin 3, on the other hand, appeared as finer puncta, which did not colocalize with clathrin, suggesting that these two dynamins have distinct functions in Sertoli cells. In the klotho deficient mouse testis, which demonstrates disorder in spermatogenesis, expression of dynamin 2 and dynamin 3 was drastically reduced indicating possible association of these proteins with spermatogenesis.

Phosphatidylinositol 4,5-bisphosphate stimulates vesicle formation from liposomes by brain cytosol.

As a step toward the elucidation of mechanisms in vesicle budding, a cell-free assay that measures cytosol-induced vesicle generation from liposomes was established. This assay then was used to explore the role of phosphoinositides in vesicle formation. Liposomes incubated with brain cytosol in the presence of ATP and GTP massively generated small vesicles, as assessed both quantitatively and qualitatively by a dynamic light-scattering assay. Both ATP and GTP were required. Vesicle formation was inhibited greatly by the immunodepletion of dynamin 1 from the cytosol, indicating a major contribution of this GTPase in this reaction and suggesting that it mimics endocytic vesicle fission. Increasing the concentration of l-alpha-phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] but not of l-alpha-phosphatidylinositol 4-monophosphate or l-alpha-phosphatidylinositol in the lipid membranes enhanced vesicle formation. Lipid analysis revealed rapid degradation of PtdIns(4,5)P2 to l-alpha-phosphatidylinositol during the incubation with the reaction reaching a maximum within 5 sec, whereas vesicle formation proceeded with a longer time course. PtdIns(4,5)P2 degradation was independent of vesicle formation and occurred also in the presence of guanosine 5'-O-(thiotriphosphate), where few vesicle formations occurred. These results suggest that PtdIns(4,5)P2 plays a critical role in the early step of vesicle formation, possibly in the recruitment of coats and fission factors to membranes.