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Hiromitsu Mimata

Publications and source records attributed to Hiromitsu Mimata.

27 records · Page 2Linked to original sources

[Usefulness of lower ihfundibular length-to-diameter ratio as a predictor of lower pole stone clearance after extracorporeal shock wave lithotripsy; clinical research with two lithotriptors].

PURPOSE: Lower pole renal stones are well known to exhibit a poor stone clearance rate following extracorporeal shock wave lithotripsy (ESWL). In the present study, we analyzed several anatomical factors as predictors of lower pole stone clearance that may be used to indicate the usefulness and the universality of ESWL in such patients with two different lithotriptors. PATIENTS AND METHODS: 93 patients with a unilateral single lower pole stone of 2 cm. or less underwent ESWL using Piezolith 2500 or Medstone STS, were included in the study. An IVP was used to determine the lower infundibulopelvic angle, the caliceal pelvic height, the lower infundibular length, the lower infundibular diameter, the lower infundibular length-to-diameter ratio and the number of lower pole minor calyces. Stone-free status was assessed by a plain film with or without renal ultrasound. RESULTS: The stone clearance rate at the Piezolith 2500 group was 53.1% (34 of 64 patients), while was 51.7% (15 of 29 patients) at the Medstone STS group. In all cases, the overall stone clearance rate was 52.7% (49 of 93 patients). Age, laterality of the stone burden within the kidney and stone size were not different between the stone-free and residual stone groups. Multivariate logistic analysis revealed that length-to-diameter ratio was the most independent predictors of successful stone clearance at each group. The patients exhibited length-to-diameter ratio less than 7 achieved high stone clearance rates, greater than 72%. In contrast, the stone clearance rate was less than one third when length-to-diameter ratio was 7 or greater. Besides length-to-diameter ratio was strong prognostic factor in patients with stones 1 cm. or less and 1 to 2 cm at each group. CONCLUSION: From this study, it is apparent that successful ESWL is highly sensitive to the anatomy of the lower pole of the kidney. Especially, the lower infundibular length-to-diameter ratio is potentially useful and a universal predictor regardless of the kind of lithotriptors at least in patients with a lower pole radiopaque stone 2 cm. or less treated with ESWL.

Adolescent↗

Enhancement by cyclosporin A of taxol-induced apoptosis of human urinary bladder cancer cells.

Taxol is a microtubule-stabilizing agent which induces apoptosis in various cancer cells. In this study, we found that T24 cells derived from high grade human urinary bladder cancer were relatively resistant to taxol and that the IC50 value determined by a colorimetric WST-1 assay was 406.0 nM. Interestingly, cyclosporin A (CsA), an immunosuppressive drug, dramatically enhanced sensitivity to taxol, and the IC50 value was decreased to 47.5 nM in the presence of 1 microM CsA. KK47 cells derived from low grade human urinary bladder cancer showed high sensitivity to taxol with an IC50 value of 78.8 nM which decreased to 14.4 nM in the presence of 1 microM CsA. FK506, another immunosuppressive drug, also enhanced sensitivity to taxol. Furthermore, a concomitant loss of calcineurin activity was observed after the treatment of both cell lines with both CsA and FK506. Taxol induced apoptosis of the cells, as assessed by Hoechst 33258 staining and by the measurement of caspase 3 activity. Immunoblot analysis with an antibody against Bcl-2 phosphorylated at serine 70 demonstrated that taxol induced the phosphorylation of Bcl-2 with its enhancement in the presence of CsA. In addition, treatment of the cells with CsA significantly decreased the expression of Bcl-2 at both the protein and mRNA levels. These results suggest that the enhancement of taxol-induced apoptosis by immunosuppressive drugs is at least partly due to the inhibition of calcineurin activity and the loss of the antiapoptotic function of Bcl-2 via the enhancement of phosphorylation and the reduction of expression.

Antineoplastic Agents, Phytogenic↗

Predictors of lower pole renal stone clearance after extracorporeal shock wave lithotripsy.

PURPOSE: Lower pole renal stones are well known to show a poor stone clearance rate after extracorporeal shock wave lithotripsy (ESWL) (Dornier Medical Systems, Marietta, Georgia). In the current study we analyzed several anatomical factors as predictors of lower pole stone clearance that may be used to indicate the usefulness of ESWL in such patients. MATERIALS AND METHODS: Between January 1993 and October 2000, 63 patients with a unilateral single lower pole stone of 2 cm. or less were included in the study. Excretory urography was done to determine the lower infundibulopelvic angle, caliceal pelvic height, lower infundibular length and diameter, lower infundibular length-to-diameter ratio and number of lower pole minor calices. Stone-free status was assessed by x-ray. RESULTS: The overall stone clearance rate was 54% (34 of 63 patients). While caliceal pelvic height, lower infundibular diameter, length, length-to-diameter ratio and number of minor calices were different in the stone-free and residual stone groups on univariate analysis, multivariate logistic analysis revealed that the lower infundibular length-to-diameter ratio, diameter and number of minor calices were independent predictors of successful stone clearance. The 13 patients (20.6%) who showed all 3 favorable anatomical factors (lower infundibular length-to-diameter ratio less than 7, diameter greater than 4 mm. and a single minor calix) achieved an impressive 84.6% stone clearance rate. In patients with only 1 or 2 favorable factors the stone clearance rate was still greater than 60%. In contrast, the stone clearance rate was only 6.7% in the 15 patients who showed none of these factors. CONCLUSIONS: From this study it is apparent that successful ESWL is highly sensitive to the anatomy of the lower pole of the kidney. If a patient with a lower pole stone has at least 1 of the favorable factors identified in this study, ESWL may be advocated as first line therapy with a greater than 60% prospect of a successful outcome. Other treatment options should be considered in those without any of these predictive factors.

Adult↗

Involvement of adrenomedullin induced by hypoxia in angiogenesis in human renal cell carcinoma.

BACKGROUND: Adrenomedullin (AM) has pluripotent activities and is involved in the regulation of vasomotor tone, cell differentiation and embryogenesis. However, the expression and pathophysiological role of AM has not been determined in human renal cell carcinoma (RCC). METHODS: Twenty-six RCC specimens and three cultured human RCC cell lines (A498, SN12C and KPK-13) were analyzed. Expression of AM was determined by immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) analysis. The correlation between AM expression and microvessel count (MVC) in RCC specimens was examined to determine if AM plays a role in tumor angiogenesis. The correlation between the expression of AM and vascular endothelial growth factor (VEGF) was also investigated. Lastly, the effect of hypoxia upon the mRNA expression of AM, VEGF and hypoxia inducible factor-1 (HIF-1) by RCC cell lines was determined. RESULTS: Immunohistochemistry indicated that AM and VEGF were primarily localized in the cytosol of RCC cells. AM and VEGF mRNA were detected in all RCC specimens and cultured RCC cell lines analyzed by RT-PCR. There was a positive correlation between AM mRNA expression and MVC (r = 0.516, P = 0.0062), and between VEGF mRNA expression and MVC (r = 0.485, P = 0.0111). We also observed a positive correlation between AM mRNA expression and VEGF mRNA expression (r = 0.552, P = 0.0029). Hypoxia significantly induced AM and VEGF mRNA expression, although the increase of the AM mRNA level (10.6-26.7 fold) was markedly greater than that of the VEGF mRNA level (1.5-1.9 fold). CONCLUSION: These results suggest that hypoxia-induced AM plays a part in tumor angiogenesis in conjunction with VEGF and facilitates human RCC growth under hypoxic conditions.

Adrenomedullin↗

Clinical significance of thymidylate synthase expression in bladder cancer.

BACKGROUND: The purpose of the present paper was to investigate the clinical significance of thymidylate synthase (TS) expression in bladder cancer and its association with proliferation markers, such as p53, Ki-67, and proliferating cell nuclear antigen (PCNA). METHODS: Thymidylate synthase gene expression in 54 patients with bladder cancer was measured by the reverse transcription polymerase chain reaction (RT-PCR) method using glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as an internal standard. The TS expression was also examined immunohistochemically. Immunohistochemical studies of p53, Ki-67, and PCNA expression were carried out to examine the correlation between TS expression and the expression of proliferation markers in the tumors. Prognostic and clinical outcome factors such as vascular invasion and distant metastasis were also examined along with TS expression. RESULTS: Twenty-four patients with invasive bladder cancer had TS levels of 5.07 +/- 0.77 (mean +/- SE), while 30 patients with superficial bladder cancer had TS levels of 2.28 +/- 0.38. There was a significant difference in TS levels between invasive and superficial bladder cancer (P = 0.001). There was a positive correlation between TS expression and each proliferation marker of p53 (r = 0.686, P < 0.01), Ki-67 (r = 0.715, P < 0.0001) or PCNA expressions (r = 0.670, P < 0.0001) in these patients. Patients with high TS levels (TS > or = 2.63, the median value) had significantly higher rates of vascular invasion and distant metastasis. Kaplan-Meier analysis demonstrated that patients with high TS levels (TS > or = 2.63) had unfavorable prognosis compared to patients with low TS levels (TS < 2.63; P = 0.034). Furthermore, patients with high TS staining had a significantly poorer prognosis than those with low staining (P = 0.012). CONCLUSION: Determination of level of TS expression may help in the selection of an appropriate treatment for bladder cancer because TS expression influences the biological characteristic of bladder tumor.

Adult↗

Clinical characteristics of alpha-blocker responders in men with benign prostatic hyperplasia.

BACKGROUND: Currently, alpha-blocker is becoming first-line drug therapy for benign prostatic hyperplasia (BPH). Although highly effective results are obtained with this therapy, a difference between the objective and subjective response rates is reported. To prevent unnecessary medical treatment and to predict the alpha-blocker response, we characterized the clinical features of alpha-blocker responders in men with BPH. METHODS: Twenty-two men were consecutively enrolled in this study and received tamsulosin 0.2 mg once daily for 4-6 weeks. The primary measures of efficacy were maximum urinary flow rate (Q(max)) determined from the flow measurements and international prostate symptom score (IPSS). Those with an increase in Q(max) of > or = 30% from baseline and a decrease in IPSS of > or = 25% from baseline were defined as Q(max) responders and IPSS responders, respectively. Clinical findings such as age, pretreatment IPSS and Q(max), serum prostate-specific antigen (PSA), total prostate volume, transition zone (TZ) volume, TZ index and T(2)-weighted magnetic resonance image (MRI) of the prostate TZ were compared between responders and non-responders for both criteria. RESULTS: In 17 of 22 (77.2%) patients IPSS improved by > or = 25%. In 9 of 22 (40.9%) patients Q(max) improved by > or = 30%. There were no differences in clinical findings between IPSS responders and non-responders. On the contrary, Q(max) responders showed smaller total prostate and TZ volumes, a smaller TZ index and a lower intensity of the TZ in MRI than Q(max) non-responders. CONCLUSIONS: Determination of the prostate volume and MRI findings of the inner prostate gland were useful in predicting Q(max) responders to the alpha-blocker in men with BPH. In contrast, there were no clinical characteristics of the IPSS responders. IPSS responders without a Q(max) response should be closely followed while continuing the alpha-blocker therapy for a long duration.

Adrenergic alpha-Antagonists↗

Cisplatin inhibits the expression of X-linked inhibitor of apoptosis protein in human LNCaP cells.

The purpose of the present study is to investigate the role of X-linked inhibitor of apoptosis protein (XIAP) in the regulation of apoptosis induced by cisplatin in human prostate cancer cell line (LNCaP). We examined the effects of cisplatin on cell growth and apoptosis in LNCaP by 2-(4-lodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt (WST-1), flow cytometric analyses, and caspase-3 activity assay. In addition, to clarify the roles of the XIAP, we established clonal cell lines that overexpressed XIAP. The effects of cisplatin on the XIAP expression in the induction of apoptosis in LNCaP were examined by RT-PCR and immunoblot analyses. Although the growth rates were reduced in a dose- and time-dependent manner by cisplatin in LNCaP sublines, the anti-proliferative effects of cisplatin were significantly decreased in XIAP stably overexpressing cell lines. In addition, we found that cisplatin-induced apoptosis following activation of caspase-3, and that the overexpression of XIAP inhibited apoptosis by attenuating caspase-3 activity. Interestingly, treatment of LNCaP cells with 10 and 100 muM cisplatin for 48 h significantly decreased the expression of XIAP at both the protein and mRNA levels in a dose-dependent manner. Furthermore, 10-muM cisplatin treatment of LNCaP decreased XIAP mRNA and protein in a time-dependent manner. These results suggest that cisplatin induces apoptosis by the inhibition of XIAP expression, and that XIAP plays an important role in the regulation of cisplatin-induced apoptosis in LNCaP cells. The ability of cisplatin to down-regulate XIAP may be an important mechanism in chemosensitivity.

Antineoplastic Agents↗