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Biomedical subjects

O Maeda

Publications and source records attributed to O Maeda.

At least 19 recordsLinked to original sources
PubMed2000

Clinical significance of nonpalpable prostate cancer with favorable biopsy features in Japanese men.

OBJECTIVE: To assess the clinical significance of nonpalpable localized prostate cancers with relatively favorable six sextant biopsy features in Japanese men. PATIENTS AND METHODS: 136 nonpalpable prostate cancers of which biopsy features confined to (1) a Gleason score of 6 or less, (2) one or two positive cores per six sextant cores, and (3) 50% or less involvement of any positive core were collected. The Gleason score, tumor extension, and cancer volume were compared with preoperative serum PSA and PSA density for the patients who underwent radical prostatectomy. PSA doubling time was measured for the patients who were treated expectantly. RESULTS: Treatments chosen for 136 patients with favorable biopsy features were radical prostatectomy alone for 48 and with preoperative androgen deprivation for 30, radiation to the prostate for 12, androgen deprivation therapy for 21, and watchful waiting for 25. Of 48 patients who underwent radical prostatectomy without androgen deprivation therapy, 25% had nonorgan-confined cancers. Seven cancers (14.6%) were Gleason score of 7, but no cancers were 8 or greater. Among 42 prostatectomy specimens for which cancer volume was measured, 22 (52.4%) had cancer volume >0.5 cm(3). Pretreatment serum PSA levels were correlated neither with the Gleason score, tumor extension nor cancer volume. There was only one nonorgan-confined cancer in the 23 cancers for which PSA density was <0.2 ng/ml/g. The ability of PSA density to predict cancer volume <0. 5 cm(3) was 0.61 using a cut-off of 0.2 ng/ml/g. Of the 25 patients treated expectantly, the PSA doubling time was less than 2 years for 3 patients, while it was stable or fluctuated for 13. CONCLUSIONS: Tumor extension can be predicted based on PSA density in nonpalpable prostate cancer with favorable biopsy features, but predictability of cancer volume based on PSA or PSA density is not satisfactorily high. New parameters or biomarkers that complement needle biopsy findings are needed to predict clinical significance of T1c prostate cancer with favorable biopsy features.

Aged↗
PubMed2000

Scirrhous cancer of the stomach which survived for more than five years after neoadjuvant chemotherapy with UFT (uracil and tegafur) and cisplatin.

A 68-year-old man was diagnosed as having a scirrhous cancer of the stomach. Carcinomatous peritonitis was suspected on abdominal CT examination. Three courses of uracil and tegafur (UFT)/cisplatin (CDDP) chemotherapy were administered. The primary foci were reduced in size, then total gastrectomy was performed. Histological findings revealed a poorly differentiated adenocarcinoma with scirrhous invasion into the subserosa. Histological efficacy of the chemotherapy was judged to be grade 2. The patient has been alive without disease for more than five years after total gastrectomy. Neoadjuvant chemotherapy with UFT and CDDP may have contributed to the favorable clinical outcome in this patient.

Adenocarcinoma, Scirrhous↗
PubMed1999

Incidence rate of satellite tumors in renal cell carcinoma.

BACKGROUND: Nephron-sparing surgery for incidentally detected small renal tumors has been performed. The main objection to such surgery concerns the incidence rate of satellite renal tumors. In this study, the authors analyzed the rate of incidence and proliferative potential of satellite renal tumors. METHODS: The tumors of 124 renal cell carcinoma patients with a clinically identified unilateral and single tumor measuring </=90 mm who were examined between November 1991 and May 1997 were analyzed prospectively. The authors determined whether these specimens obtained by radical nephrectomy had satellite tumors, and whether the satellite tumors were reactive with a monoclonal antibody (MoAb), MIB-1, to assess their proliferative potential. RESULTS: Satellite renal cell carcinomas were detected in 8 of the 124 patients (6.5%). None of the pathologic variables examined (tumor grade, tumor stage, main tumor size, cell pattern, and vascular invasion) were found to be predictive of the presence of satellite tumors. Of these eight tumors, two main tumor specimens and three satellite tumor specimens reacted with the MIB-1 MoAb. The reactivity of MIB-1 correlated with the tumor grade. The satellite tumors were observed to have a proliferative potential compared with the main tumors. Among 86 kidney specimens from patients with urothelial tumors after total nephroureterectomy, 2 (2.3%) contained small renal cell carcinoma but did not show positive staining with the MoAb MIB-1. CONCLUSIONS: The incidence rate of satellite tumors among 124 renal cell carcinoma patients was 6.5% and the presence of satellite tumors was not predictable. Some of these satellite tumors showed positive staining with the MIB-1 MoAb, but small renal tumors detected in kidney specimens with urothelial tumors did not.

Adult↗
PubMed1999

Impact of tumor size on the clinical outcomes of patients with Robson State I renal cell carcinoma.

BACKGROUND: In the TNM classification of renal cell carcinoma released in 1997, T1 tumors were defined as organ-confined tumors 7.0 cm or less in size, and T2 as those larger than 7.0 cm. The consideration of tumor size should be predicated on its prognostic value in predicting survival, because the goal of clinical staging is to separate patients into similar classes of survival based on the extent of disease at presentation. The authors examined the impact of tumor size on the clinical outcomes of patients with Robson Stage I disease to determine a size cutoff that would maximize the predictive value of the TNM staging system. METHODS: Between 1962 and 1995, 382 patients with renal cell carcinoma were treated at the Department of Urology at the Osaka Medical Center for Cancer and Cardiovascular Diseases in Osaka, Japan, and the TNM staging of 350 of those patients was recorded. Of 350 patients, 157 (45%) were at TNM Stage I, 47 (13%) at Stage II, 65 (19%) at Stage III, and 81 (23%) at Stage IV, according to the TNM stages defined in 1997. Robson Stage I includes TNM Stages I and II, and 204 patients in these stages were analyzed in this study. This study group included 146 men and 58 women with a mean age of 57.8 years (range, 26-84 years). The mean follow-up period was 5.4 years. RESULTS: The patient survival periods were not significantly different for those with TNM Stages I and II. This finding indicated that the tumor size cutoff of 7.0 cm was not useful in predicting the prognosis. The patients at TNM Stages I and II were then divided into two groups at each size cutoff, from 2.5 cm to 9.0 cm, at 0.5-cm intervals. The tumor size cutoff of 5.5 cm was most predictive of patient survival (P = 0.0121). None of other patient characteristics varied significantly between the two groups at this dichotomous point. Tumor size and microscopic intrarenal venous invasion, but not grade or infiltration pattern, were found in univariate and multivariate analyses to be significantly predictive of the survival of Robson Stage I patients after radical nephrectomy. CONCLUSIONS: The current data indicate that the tumor size cutoff of 5.5 cm was most significantly predictive of the survival of Robson Stage I patients after radical nephrectomy. The tumor size cutoff of 5.5 cm was also shown to be significant in univariate and multivariate analyses.

Adult↗
PubMed1999

[Renal oncocytoma with cystic degeneration: a case report].

A 45-year-old man was referred to our department because of a right renal mass which was incidentally found at a health screening. Ultrasound sonography, computerized tomography and magnetic resonance imaging showed a hypovascular tumor 3 cm in diameter with the fluid at the upper pole of the right kidney, implicating that the tumor was renal cell carcinoma originating from a renal cyst wall, or with central necrosis. A radical nephrectomy was therefore performed. The tumor was dark-brown and contained brown fluid. The histopathological findings showed renal oncocytoma with cystic degeneration.

Adenoma, Oxyphilic↗
PubMed1999

[Results of chemotherapy and salvage surgery for advanced testicular cancer].

Since 1980, 73 patients with advanced testicular cancer have been treated with chemotherapy and 43 patients received post-chemotherapy (salvage) surgery. The median age of all patients was 31 years old, ranging from 17 to 63 years. The histology of the primary testicular tumor was pure seminoma in 23 patients and non-seminoma in 50 patients. According to the Japan Urological Association classification, 38 patients were classified as stage II and 35 patients as stage III. As first-line chamotherapy, 52 patients were treated with PVB regimen (cisplatin, vinblastin, bleomycin), 16 patients with PEB (cisplatin, etoposide, bleomycin) and 5 patients with VAB-6 (vinblastine, actinomycin-D, bleomycin, cisplatin, cyclophosphamide). Thirty (41%) of the 73 patients achieved a complete response (CR) with chemotherapy alone and 63 (86%) achieved no evidence of disease (NED) with salvage treatment. As second-line chemotherapy, 16 patients were treated with PE (cisplatin, etoposide), or VIP (etoposide, ifosfamide, cisplatin) or VeIP (vinblastine, ifosfamide, cisplatin). One of the 16 patients achieved CR and 11 (69%) patients achieved NED. As salvage surgery, retroperitoneal lymphnode dissection (RPLND) was performed in 22 patients, RPLND with thoracotomy in 7 cases and thoracotomy alone in 4 cases. Necrosis was found in surgical specimens of 24 (56%) patients, mature teratoma in 6 (14%) and residual cancer in 13 (30%). Ninety-six percent and 100% of the patients with necrosis and mature teratoma survived with NED, respectively, but only 54% of the patients with residual carcinoma survived despite further treatment. Residual cancer was still found in 8 of the 32 (25%) marker normalized cases. Residual cancer could not reliably be predicted or discriminated from necrosis or mature teratoma by the prognostic criteria. Therefore, salvage surgery remains essential in the treatment of advanced testicular cancer.

Adolescent↗
PubMed1998

Adjunctive value of cell proliferation but not of apoptosis to interpret pathologic effects on prostatic cancer after neoadjuvant endocrine therapy.

BACKGROUND: The current histological evaluation of the effects of endocrine therapy has difficulty in distinguishing pathologic degeneration caused by androgen ablation from residual poorly differentiated tumor. Therefore, we examined the changes in cell proliferation and apoptosis before and after endocrine therapy and analyzed whether they correlated with pathologic effects and histological differentiation. METHODS: Between January 1986 and December 1995, 52 patients with clinical stage B2 and C prostate cancer underwent radical prostatectomy after neoadjuvant endocrine therapy (median duration 3.8 months). Proliferative and apoptotic activities of pretreatment biopsy specimens and radical prostatectomy specimens were analyzed with MIB-1 monoclonal antibody and in situ end-labeling of fragmented DNA. RESULTS: The mean proliferative index (PI) of radical prostatectomy specimens was significantly lower than that of biopsy specimens (P = 0.000003) and the decrease in PI after endocrine therapy was significantly related to histological differentiation (P = 0.014). There was a weak relationship between the decrease in PI after endocrine therapy and pathologic effects (P = 0.054), while in pathologically effective cases (Grades 2 and 3), three out of 16 (19%) showed a < 50% decrease in PI after endocrine therapy, and may be regarded as having poorly differentiated tumors. The mean apoptotic index (AI) of prostatectomy specimens tended to be higher than that of biopsy specimens (P = 0.054). The increase in AI after endocrine therapy was not related to histological differentiation and pathologic effects. CONCLUSION: Pathologic effects caused by endocrine therapy may be in part misled by routine histopathologic staining and the change in PI may help in recognizing the pathologic effects of endocrine therapy and have adjunctive value for the interpretation of the effects of endocrine therapy.

Aged↗
PubMed1998

Effect of gadolinium chloride treatment on concanavalin A-induced cytokine mRNA expression in mouse liver.

The effect of Kupffer cell depression on concanavalin A (Con A)-induced cytokine mRNA expression in the liver was studied. Gadolinium chloride (GdCl3) is a commonly used Kupffer cell inhibitor. GdCl3 (40 mg/kg, i.p.) was injected into each mouse, and 24 hr later, Con A (0.2 mg/mouse) was administered. Plasma was obtained at 24 hr after Con A treatment for alanine aminotransferase (ALT) measurement. GdCl3 treatment inhibited Con A-induced elevation of ALT. However, it did not inhibit Con A-induced interleukin-2 or tumor necrosis factor-alpha mRNA expression. The present results suggest that Kupffer cells are not responsible for Con A-induced cytokine expression in the liver.

Alanine Transaminase↗
PubMed1998

[Clinical staging and management of prostate cancer].

Through the use of digital rectal examination, prostate-specific antigen and improved biopsy technique, it is possible to diagnose early stage prostate cancer. The management of this disease, however, has generated considerable controversy. The decision whether to treat actively or conservatively must be made on the basis of accurate staging and grading technique, a patient's life expectancy and performance status. This article will show the current staging and management of prostate cancer as practiced in Japan.

Humans↗
PubMed1998

[Application of radical prostatectomy for prostate cancer and its outcome].

The proportion of patients with localized prostate cancer treated by radical prostatectomy is increasing rapidly in Japan. As for the qualifications of patient candidates for radical surgery, various clinical and pathological findings to predict tumor extent and disease-free outcome must be considered carefully. There has been increased interest in the application of neoadjuvant or adjuvant therapy for locally advanced tumor group in order to improve disease-free survival and overall survival. The new anatomical approach to radical prostatectomy with its nerve sparing option assures preservation of erection. This procedure achieves excellent cancer control for patients with a definite organ-confined tumor preoperatively. Finally, more time is needed to obtain information on the long-term outcome after radical prostatectomy.

Aged↗
PubMed1998

[Clinical significance of prostate specific antigen (PSA) and PSA density in the detection of T1a and T1b prostate cancer].

The clinical significance of preoperative prostate specific antigen (PSA) and PSA density (PSAD) in distinguishing stage T1a and T1b prostate cancer from benign prostatic hyperplasia (BPH) was studied retrospectively in men who had undergone surgery for BPH. A total of 202 clinically BPH patients underwent transurethral resection of prostate (TURP) or retropubic prostatectomy, and histopathological findings were BPH in 179 patients, T1a cancer in 10 patients and T1b cancer in 13 patients. The T1a cancer group was similar to the BPH group in all parameters. The PSA and PSAD values in the T1b cancer group were significantly higher than those in the BPH group (P < 0.001). Prostate volume and amount of tissue resected in the T1b cancer group were significantly smaller than those in the BPH group (p < 0.001). The cut-off values of PSA and PSAD were examined with T1a and T1b cancer as a positive control and histologically proven BPH as a negative control. When 8.0 ng/ml was used as the PSA cut-off value, the sensitivity was 65% and specificity was 70%. When 0.25 ng/ml/ml was used as the PSAD cut-off value, the sensitivity and specificity were 65% and 75%, respectively. PSAD was useful for improving the specificity. Almost all the cases undetected by using both cut-off values were of T1a cancer. The receiver operating characteristics curve demonstrated that at any point, PSAD was a better detector for distinguishing T1a, T1b cancer from BPH, focusing especially in the range of PSA level between 6.0 and 10.0 ng/ml. These findings suggest that PSA and PSAD are useful parameters in distinguishing T1b cancer from BPH before surgery.

Aged↗
PubMed1998

[Bilateral synchronous adrenal myelolipomas: a case report].

A 70-year-old man, who was diagnosed by computed tomographic scan as having bilateral synchronous adrenal myelolipomas 6 years ago during the follow-up of fatty liver, underwent tumor resection at our Department because of growth of bilateral tumors without any subjective symptoms. Histopathological examination revealed mature adipose tissue cells without atypism and areas of hematopoietic tissue, including the myelotic, lymphotic, erythrocytic, and megakaryocytic cells. The diagnosis of myelolipoma was confirmed. The in vivo doubling time of bilateral tumors was 16.1 months and 31.3 months, respectively.

Adrenal Gland Neoplasms↗
PubMed1998

[Labial adhesion presenting as urinary incontinence and dysuria in a postmenopausal woman: a case report].

A 68-year-old woman admitted to our hospital complaining of urinary incontinence and dysuria. On examination, the labia were found to be fused extensively, with a pinhole opening at the midline. Under spinal anesthesia, the adhesion was clearly separated with the Hegar's dilator. There remains no recurrence in this patient following therapy. The labial adhesion was considered to be an acquired disease caused by infection, trauma in the genitalia, or sexless life, according to hypoestrogenism.

Aged↗
PubMed1997

Vitamin C inhibits the growth of a bacterial risk factor for gastric carcinoma: Helicobacter pylori.

BACKGROUND: Helicobacter pylori infection is a risk factor for gastric carcinogenesis. High dietary vitamin C intake appears to protect against gastric carcinoma. It has been suggested that vitamin C exerts the protective effect by scavenging free radicals that may be enhanced by H. pylori. However, vitamin C has not been investigated in relation to the direct action on H. pylori. In this study, the authors attempted to clarify this possibility both in vitro and in vivo. METHODS: Susceptibility testing of H. pylori (64 strains) was performed by the agar dilution method. Bactericidal actions were determined by a broth cultivation technique. The effect of vitamin C on in vivo H. pylori colonization was evaluated by using the Mongolian gerbil model. RESULTS: At concentrations of 2048, 512, and 128 microg/mL (minimum inhibitory concentrations [MICs]), vitamin C could inhibit the growth of 90% of the bacterial stains incubated at pH values of 7.4, 6.0, and 5.5, respectively. The broth cultures exposed to the MICs of vitamin C displayed a 1.57 approximately 2.5-log decrease in the number of viable bacteria, and the loss of viability was observed in 24 hours at concentrations 8-fold higher than the MICs. In an in vivo experiment, H. pylori colonies decreased significantly in animals treated with vitamin C after oral administration of vitamin C (10 mg/head/day) for 7 days. CONCLUSIONS: High doses of vitamin C inhibit the growth of H. pylori in vitro as well as in vivo.

Animals↗
PubMed1997

No. 302, a newly synthesized [pGlu4,Cyt6]AVP(4-9) analogue, prevents the disruption of avoidance behavior.

We investigated the effects of [pGlu4,Cyt6]AVP(4-9) fragments and its analogues on cycloheximide (CHX)-induced learning impairment in rats using the step-through-type passive avoidance test in rats. CHX (2.8 mg/kg, s.c.) significantly shortened the step-through latency in the retention trial. pGlu-Asn-Cys(Cys)-Pro-Arg-Gly-NH2 ([pGlu4, Cyt6]AVP(4-9); 10 ng/kg, s.c.), a major metabolite of arginine vasopressin, improved the CHX-induced learning impairment. Asn-Cys-Pro-Arg-OH ([Cys6]AVP(5-8); 1 ng/kg) corrected avoidance learning in the CHX-treated group, whereas neither Cys(Cys)-Pro-Arg-OH nor pGlu-Asn-Cys(Cys)-Pro-OH had any effect (1, 10 and 100 ng/kg, s.c.). pGlu-Asn-Ser-Pro-Arg-Gly-NH2 (No. 302), a newly synthesized [pGlu4,Cyt6]AVP(4-9) analogue, significantly prolonged the latency shortened by CHX at doses of 0.1, 1 and 10 ng/kg (s.c.). Asn-Ser-Pro-Arg-OH also improved the learning disruption induced by CHX, although the effective dose was 100 times higher than that of No. 302. The half-life of No. 302 in rat blood was about 5.5, 22 and 25 times longer than that of [pGlu4,Cyt6]AVP(4-9), [Cys6]AVP(5-8) and Asn-Ser-Pro-Arg-OH, respectively. These results suggest that [Cys6]AVP(5-8) is the minimal effective amino acid sequence in [pGlu4,Cyt6]AVP(4-9), and show that No. 302 is a potent, pharmacologically active peptide with high stability in the blood.

Animals↗
PubMed1997

Hyaluronidase activity in gynaecological cancer tissues with different metastatic forms.

We investigated hyaluronidase activity in gynaecological normal and malignant tissues. Hyaluronidase activity in culture medium of tissue specimens was detected by hyaluronic acid zymography and quantified by densitometry. Hyaluronidase activity was shown as one dominant band (molecular weight 65 kDa) at pH 3.5. Hyaluronidase activity was significantly higher in normal ovary (P < 0.05) and normal endometrium (P< 0.05) than in normal cervix. One dominant 65-kDa hyaluronidase was expressed in 100% (14 out of 14) of ovarian cancer tissues and in 91% (10 out of 11) of endometrial cancer tissues. However, hyaluronidase activity was not observed in cervical cancer tissues. Hyaluronidase activity was significantly higher in ovarian (P < 0.001) and endometrial (P < 0.01) cancer tissues than in cervical cancer tissue and was significantly higher in ovarian cancer tissue than in endometrial cancer tissue (P < 0.05). These facts suggest that the cancer cells make use of the original characteristic of the organ to invade and metastasize. Moreover, these results reflect the difference in metastatic forms and are suggestive of a strong relationship between hyaluronidase activity and invasion and metastasis of ovarian and endometrial cancers compared with cervical cancer.

Adult↗
PubMed1997

Antitumor effect of CPT-11, a camptothecin derivative, on human testicular tumor xenografts in nude mice.

OBJECTIVE: The antitumor effect of CPT-11, a camptothecin derivative, on two human testicular embryonal carcinomas (TTSC-2 and TTSC-3) heterotransplanted into-nude mice was studied. MATERIALS AND METHODS: Tumor-bearing nude mice were given daily intraperitoneal injections of the anticancer drugs in 0.1 ml saline 3 times at 3-day intervals. At the end of the experiments tumors were resected and subjected to light-microscopic observation. RESULTS: When 10, 30 and 50 mg/kg of CPT-11 was administered to tumor-bearing mice intraperitoneally, the antitumor effect of CPT-11 was observed dose-dependently in both TTSC-2 and TTSC-3. When 30 mg/kg of CPT-11 was administered in combination with CDDP, complete tumor regression was observed in both TTSC-2 and TTSC-3 tumors. Histological findings correlated well with the decrease in tumor volume of treated tumors. No mice died after treatment with CPT-11 in a single-agent and combination chemotherapy. CONCLUSION: Chemotherapy with CPT-11 was an effective and safe method against human testicular tumors heterotransplanted in nude mice.

Animals↗