Temperature dependence of dielectric permittivity of perovskite-type artificial superlattices.

Perovskite-type BaTiO(3)/SrTiO(3) (BTO/STO) artificial superlattices were fabricated by the molecular beam epitaxy method. The X-Ray diffraction (XRD) profiles and reflection, high-energy, electron diffraction (RHEED) oscillations during the growth of superlattices indicated that crystalline orientation toward [001] direction and two-dimensional layer-by-layer growth were achieved. The capacitance, dielectric loss tangent, and complex admittance were measured up to 145 degrees C and up to the frequency of 100 MHz with the microplaner interdigital electrodes. Dielectric permittivity of superlattices was evaluated from the complex admittance with an electromagnetic field analysis as a function of temperature. The [BTO(10)/STO(10)](4) superlattice showed the enormous relative permittivity of 19,000 at room temperature and the dielectric relaxation was observed. The linear relations in the charge versus voltage curves were observed in these superlattices, and the shape of Q-V curves were not changed as a function of temperature. Temperature dependence of dielectric properties of the BTO/STO superlattices was evaluated. It was found that the BTO/STO superlattices did not show a peak in the dielectric permittivity versus temperature curve, which was different from the behavior of BTO-STO bulk ceramics and normal thin films. These results strongly supported that the high permittivity of the superlattices was caused by temperature-stable anisotropic strains induced in the superlattices.

[Urinary diversion--the key to reducing surgical complications--ileal conduit].

The ileal conduit, first described by Bricker in 1950, continues to be the most common form of incontinent urinary diversion. We have evaluated the surgical methods, pre- and post-operative management, complications and quality of life in the patients treated with ileal conduit urinary diversion. Between January, 1980 and December, 2004, ileal conduit was performed in 97 cases (82 male, 15 female) and median follow-up was 37.7 months (11 to 121 months). Early complications occurred in 38 patients (39%); however, none of them resulted in post-operative death within one month. Late complications were noticed in 60 patients (62%). The most frequent complications include stoma related complications (34 cases, 35%). Renal dysfunction was seen in only 7 cases (7.2%). A questionnaire survey on 13 patients with ileal conduit revealed that 93% of them were satisfied with the current conditions. The ileal conduit is considered an appropriate method of continent urinary diversion because of the simplicity of surgical method, few complications and high satisfaction in the quality of life.

[Two cases of renal cell carcinoma arising in the native kidney following renal transplantation--clinical study and review of 26 cases reported in Japan].

Renal transplant recipients have an increased risk of developing malignancies due to long-term immunosuppression. Two cases of renal cell carcinoma arising from the native kidney following renal transplantation are reported. Case 1; A 60-year-old man underwent cadaveric renal transplantation on July 31, 1995. He had resumed hemodialysis because of graft failure on June 5, 2000. He was referred to our hospital with macroscopic hematuria on March, 2002. Computed tomography (CT) demonstrated a right renal mass of about 3.0 cm in diameter with bilateral acquired cystic disease of the kidney (ACDK). The radical nephrectomy was performed. Case 2; A 55-year-old man underwent cadaveric renal transplantation on November 15, 1996. He had resumed hemodialysis because of graft failure on June 5, 1996. A left renal mass measuring 3.0 cm in diameter as well as bilateral ACDK were found by CT on July, 2002. Left radical nephrectomy was performed. The histological diagnosis of both renal tumors was renal cell carcinoma, clear cell type, G2, pT1a. Fifty-six renal transplantations (48 were renal allografts from cadavers, while 8 were from living donors) were performed in our hospital from 1980 to 2002. Two patients (3.6%) developed renal cell carcinoma after transplantations. We also discuss a clinical study and review of 26 cases reported in Japan. Since the incidence of malignant neoplasia is high, CT and ultrasonography should be performed routinely on the patients with renal transplantation.

Percutaneous radiofrequency ablation with transarterial embolization is useful for treatment of stage 1 renal cell carcinoma with surgical risk: results at 2-year mean follow up.

OBJECTIVES: Despite laparoscopic partial nephrectomy and laparoscopic cryotherapy being performed lately, an even less invasive treatment would be desirable in high-risk patients. Under local anesthesia with i.v. sedation, we were able to perform percutaneous radiofrequency ablation (RFA) combined with renal arterial embolization for unresectable stage 1 (T1NoMo) renal cell carcinoma (RCC). We evaluated the feasibility, safety and therapeutic effects of this technique after a 2-year mean follow up. METHODS: Thirty-one patients who were not candidates for surgery underwent RFA for 36 stage 1 RCC. Twenty-eight tumors were percutaneously ablated 6 days after the tumor vessels were embolized. Dynamic contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) were performed to evaluate treatment at completion. RESULTS: Tumor enhancement was eliminated after two RFA sessions in all tumors. Thirty tumors remained free of enhancement during a mean follow-up period of 24.3 months. There were no major complications related to the procedures though one instance of pyonephrosis, two of subcapsular hematomas, one of retroperitoneal hemorrhage and one of nausea were seen after RFA. Two patients died of other diseases (i.e. colon cancer and cerebral bleeding) 20 and 26 months after RFA treatment. One patient had a local recurrence of tumor and underwent re-RFA. The recurrence rate of RCC after successful RFA was 2.8%. There was no recurrence in patients who had tumors of less than 4 cm after RFA at a mean follow-up period of 24.3 months. Local control was achieved in 100% of T1NoMo tumors including the recurrence case that underwent re-RFA. CONCLUSIONS: The result of the present study at 2-year mean follow up showed percutaneous RFA was a feasible, safe and promising therapy for the treatment of unresectable stage 1 RCC, especially those smaller than 4 cm.

Global update on defining and treating high-risk localized prostate cancer with leuprorelin: an Asian perspective.

Data from the Japanese Urological Society showed that, in Japan, almost half of patients with localized prostate cancer are treated with hormone therapy (HT), regardless of disease stage, and that radiation therapy (RT) is also widely used to treat high-risk patients. A retrospective study was undertaken in Japan to evaluate the potential benefits of using primary HT in locally advanced prostate cancer. Of 628 patients in the study, 63.5% were treated with combined androgen blockade (CAB; luteinizing hormone-releasing hormone agonists plus an antiandrogen) and 36.5% with medical or surgical castration. CAB treatment was significantly better than hormone monotherapy for disease-specific survival. The results also showed that, even if a patient is classified as 'high-risk', a good prognosis could normally be predicted based on certain variables: if their initial prostate-specific antigen (PSA) level was < or = 20 ng/mL, their Gleason score was < or = 6, and their nadir PSA decreased to < or = 0.2 ng/mL within 6 months of HT. In this subgroup of 'good responders', any treatment, be it prostatectomy, RT or CAB, is likely to be effective. However, in 'poor responders', combined therapies with CAB and high-dose rate brachytherapy are likely to be needed for a clinical response. While HT is effective, it might be associated with a reduction in the patient's quality of life (QoL) due to adverse effects, e.g. a reduction in sexual function. Results from the analysis of QoL questionnaires completed by men of different ages with prostate cancer found that only sexual function, and not other QoL variables, in men aged 50-59 years appeared to be reduced in men who had HT, compared to age-matched controls.

Radiofrequency ablation combined with renal arterial embolization for the treatment of unresectable renal cell carcinoma larger than 3.5 cm: initial experience.

The purpose of the study was to evaluate the feasibility, safety, and therapeutic effects of the combination of renal arterial embolization and radiofrequency (RF) ablation to reinforce the anticancer effect on renal cell carcinomas (RCCs) measuring 3.5 cm or larger. This study was undertaken to evaluate this combined therapy on large RCCs-based tumor geometry. Eleven patients with 12 RCCs 3.5 cm or larger in diameter (3.5-9.0 cm) underwent combined therapy. Two were exophytic tumors, and the remaining 10 tumors had components extending into the renal sinus fat. Tumor vessels were selectively embolized in nine patients and the renal artery was completely embolized in two patients with polyvinyl alcohol or ethanol mixed with iodized oil. RF ablation was percutaneously done under the computed tomographic (CT)-fluoroscopic guidance. Response to treatment was evaluated by dynamic contrast-enhanced CT and magnetic resonance (MR) imaging. Tumor enhancement was eliminated after a single RF session in nine tumors (75%), after two sessions in two tumors (17%), and after four sessions in one tumor (8%). Both exophytic tumors (100%) and 7 of 10 tumors having components in the renal sinus fat (70%) were completely ablated with a single RF session. All tumors remained controlled during a mean follow-up period of 13 months and showed significant reduction in tumor sizes (5.2 +/- 1.7 cm to 3.6 +/- 1.4 cm, p < 0.001). A delayed abscess developed in the ablated lesion in a patient, which was percutaneously drainaged. Combined therapy as described in this report is a feasible, relatively safe, and promising treatment method for large RCCs regardless of tumor geometry.