Biomedical subjects

J Nakashima

Publications and source records attributed to J Nakashima.

At least 19 recordsLinked to original sources

PubMed2005

Inhibition of Wnt signaling downregulates Akt activity and induces chemosensitivity in PTEN-mutated prostate cancer cells.

BACKGROUND: The cross-talk between Wnt signaling and the Akt pathway in prostate cancer (Pca) is still unclear. In the present study, we found that WIF-1 downregulates the Akt pathway and also enhances chemosensitivity in PTEN-null Pca cells. METHODS: Wnt inhibitory factor-1 (WIF-1), an inhibitor of Wnt proteins, was transfected into PC-3 and DU145 Pca cells. RESULTS: Akt was phosphorylated in PTEN-null PC-3 cells but underphosphorylated in PTEN-expressed DU145 cells. The levels of phosphorylated Akt in WIF-1 overexpressing PC-3 cells were lower than those in native or control vector-transfected PC-3 cells. However, WIF-1 showed no additional inhibition of already reduced Akt activity in DU145 cells. Overexpression of WIF-1 resulted in sensitizing PC-3 cells for paclitaxel to induce apoptosis. DU145 cells were more sensitive to paclitaxel but were not affected by WIF-1 transfection. The PI3K inhibitor LY294002 seemed to restore the chemosensitivity of native PC-3 cells like WIF-1 did. CONCLUSIONS: Our results show that Wnt signaling is involved in Akt activation in Pca cells. Our data also indicate the possibility that Wnt and its signaling pathway can be therapeutic targets for PTEN-mutated advanced Pca.

Adaptor Proteins, Signal Transducing↗

PubMed2001

Characterization of a newly established cell line derived from human adrenocortical carcinoma.

BACKGROUND: ACT-1, a new cell line of human adrenocortical carcinoma, has been established and successfully maintained in culture. This study examined the biological characteristics of the cells. METHODS: The tumor cells were isolated from a surgical specimen of the tumor thrombus and cultured in monolayer. RESULTS: Histologically, the primary tumor was composed of a solid proliferation of large polygonal cells. A part of the atrophic adrenal cortex remained at the periphery of the tumor. The cultured ACT-1 cells were spindle-shaped in morphology and grew exponentially with an approximate population doubling time of 24 h. A chromosomal analysis revealed a modal number of 61 with consistent structural abnormalities of add(3)(q11), add(9)(p11), and add(16)(ql1). The expression of 3beta-hydroxysteroid dehydrogenase was observed in the ACT-1 cells as well as in normal human adrenal glands. CONCLUSIONS: The ACT-1 cell line provides a reproducible model system which gives good insight into the oncogenesis of adrenocortical carcinoma.

Adrenal Cortex Neoplasms↗

PubMed2001

Age-related prevalence of erectile dysfunction in Japan: assessment by the International Index of Erectile Function.

BACKGROUND: The effects of age and concomitant chronic illness on male sexual function were investigated to obtain insight into the prevention of erectile dysfunction (ED). METHODS: A questionnaire from the International Index of Erectile Function (IIEF) was given to 2311 non-institutionalized men aged 23-79 years along with a survey of health status. The study sample consisted of 1517 men who provided complete responses to the questionnaire. For statistical analysis, ANOVA was conducted to evaluate the effect of aging on the sexual functions and a logistic regression model was used to identify significant independent risk factors for ED. RESULTS: There was a significant correlation between age and the scores for erectile function, orgasmic function, sexual desire and intercourse satisfaction. The prevalence of moderate and severe cases of ED were 1.8% and 0% for ages 23-29; 2.6% and 0% for ages 30-39; 7.6% and 1.0% for ages 40-49; 14.0% and 6.0% for ages 50-59; 25.9% and 15.9% for ages 60-69; and 27.9% and 36.4% for ages 70-79 years, respectively. Hypertension, diabetes mellitus, heart disease, chronic hepatitis, disc herniation and cerebral infarction under treatment with anticoagulants were significant independent risk factors for ED. CONCLUSIONS: The results obtained indicated a significant association between aging and chronic diseases and erectile function. Further epidemiologic research and analysis of individual risk factors are required to allow more effective future strategies for the treatment and prevention of ED.

Adult↗

PubMed2001

Establishment of a testicular carcinoma cell line producing alpha-fetoprotein.

OBJECTIVE: To characterize a newly established human testicular carcinoma cell line that continuously produces alpha-fetoprotein (AFP), and to investigate the effects of retinoic acid on AFP production. MATERIALS AND METHODS: A 24-year-old man underwent a radical orchidectomy for a right testicular tumour and was found to have two separate metastatic lesions in the lungs, both of which were removed surgically. The cancer cells were isolated from one of the tumours, which was composed of undifferentiated germ cells and produced AFP; the cells were cultured in a monolayer. This cell line was designated as KU-MT. RESULTS: The cell line was successfully maintained both in athymic nude mice and in culture. Histological examination showed that the xenografted tumours were composed of cells in the reticular, solid and glandular patterns of a yolk sac tumour, and of embryonal carcinoma cells. These cells immunostained positively for AFP. On electron microscopy, the extracellular deposition of a basement lamina-like substance, a typical feature of yolk sac tumour, was detected. The AFP production in mice correlated well with the tumour weight of the xenograft. The cultured KU-MT cells were oval to polygonal in morphology and grew exponentially, with a population doubling time of approximately 2 days. Chromosomal analysis showed a modal number of 57 with consistent structural abnormalities of +add(1)(p13), del(1)(q32), del(2)(q31), add(6) (q21), +add(9)(p22), add(11)(p15), and add(14)(p11). Reverse-transcription polymerase chain reaction analysis showed that the retinoic acid receptors (RAR)-alpha, RAR-gamma, and retinoid X receptor-alpha were present in the cells. The expression of AFP mRNA was up-regulated in response to all-trans-retinoic acid; treatment with this agent caused morphological changes and induced apoptosis in the cells. CONCLUSIONS: This newly established cell line provides a reproducible model system that should offer a good insight into the differentiation of testicular carcinoma.

Adult↗

PubMed2001

Expression of estrogen receptor (ER-alpha and ER-beta) mRNA in human prostate cancer.

OBJECTIVE: The distribution of the two estrogen receptors (ER-alpha, ER-beta) in human prostate tissue have not been fully clarified, so the present study investigated the mRNA expression of the receptors to explain the broad spectrum of estrogen activity in prostate cancer. MATERIALS AND METHODS: Four human prostate cancer cell lines (LNCap, JCA-1, DU-145 and PC-3) and 24 pairs of untreated prostate cancer tissue and noncancerous tissue from resected prostate glands were subjected to RT-PCR testing. RESULTS: Both LNCap and JCA-1 expressed the mRNA of both receptors, but DU-145 and PC-3 only expressed ER-beta mRNA. In the human prostate tissue samples, 20 of the 24 prostate cancer tissues expressed ER-alpha, and 23 of the 24 expressed ER-beta. Of the 24 noncancer tissues, 14 expressed ER-alpha mRNA and 17 expressed ER-beta mRNA. The incidence of ER-beta mRNA expression between the paired cancer and noncancer tissues was statistically significantly different (p<0.05). CONCLUSIONS: A higher incidence of ER-beta mRNA expression in untreated prostate cancer tissues was observed. Furthermore, the absence of ER-alpha mRNA and the presence of ER-beta mRNA expression in hormone-independent and/or untreated prostate cancer cells leads to a tentative speculation of the mechanism of the hormone refractory feature of prostate cancer.

Estrogen Receptor alpha↗

PubMed2001

[Clinical efficacy of leuprolide acetate and combined treatment with estramustine for advanced prostate cancer].

BACKGROUND/PURPOSE: Twenty-two institutes have organized Keio University Prostate Cancer Study Group to study clinical efficacy and safety of Leuprolide acetate (Leuplin) for the treatment of advanced prostate cancer (clinical stage D1 and D2). Cotreatment of Leuplin and Estramustine phosphate disodium (Estracyt) has been performed to investigate its clinical efficacy. MATERIALS AND METHODS: One hundred and two cases of advanced prostate cancer were treated either with Leuplin alone (group I), Leuplin and Estracyt (group II) or Estracyt alone (group III). After 12 weeks treatment, clinical effects against subjective symptoms (pain, voiding difficulty, performance status and body weight), serum testosterone level, tumor size and serum PSA level were examined to investigate short-term effect of each treatment. The treatment had been continued for 24 months and the treatment effects including progression free survival and overall survival were analyzed. RESULTS: Clinical efficacy after 12 weeks treatment were examined among 97 cases (group I; 35 cases, group II; 36 cases, group III; 26 cases). The background of those patients in each group was statistically equal. Treatment effects against subjective symptoms and serum testosterone level statistically revealed no significant difference among 3 groups. Treatment effects against primary tumor, bone metastatic lesion, lymphnode metastatic lesion and serum PSA level were investigated and anti-tumor effect was characterized by total efficacy rate (complete remission rate plus partial remission rate) of each treatment group. Treatment efficacy rates for each lesion and PSA demonstrated no statistical difference among 3 treatment groups. Total efficacy rate of group I, II and III were 88.2%, 84.0% and 78.3%, respectively, which statistically revealed no significant difference. Total efficacy rate of each group after completing 24 months treatment was; group I 80.0%, group II 55.6% and group III 83.3%, which statistically showed no significant difference among 3 treatment groups. The median day for progression free survival of group I, II and III were 661, 731 and 517, respectively. The overall survival rate of group I, II and III after completing 24 months treatment were 77.5%, 83.0% and 72.4%, respectively. Both progression free survival rates and overall survival rates revealed no significant difference among 3 groups. Side effects during 24 months treatment were seen in 8.6% of group I, 47.2% of group II and 26.9% of group III, and these occurrence rates were significantly different among the groups (p = 0.0013). CONCLUSION: Although number of the cases had not been able to continue the treatment for their side effects, the statistical characterization demonstrated that cotreatment of Leuplin and Estracyt had no greater treatment effect than monotreatment of each drug.

Aged↗

PubMed2000

Prognostic value of alkaline phosphatase flare in patients with metastatic prostate cancer treated with endocrine therapy.

OBJECTIVES: To assess the prognostic significance of alkaline phosphatase (ALP) flare in 114 patients with metastatic prostate cancer treated with endocrine therapy. METHODS: ALP flare was defined as a transient increase of the serum ALP level to 120% or more of the pretreatment value after the initiation of endocrine therapy, followed by a subsequent decrease. RESULTS: Univariate analysis demonstrated that patients with poorly differentiated adenocarcinoma, an extent of disease of 2 or greater, a serum ALP level above twice the upper limit of normal, a serum prostate-specific antigen level greater than 100 ng/mL, an ALP flare, and a hemoglobin level of 12 g/dL or less had a significantly lower survival rate than their respective counterparts. Multivariate Cox's proportional hazards model analysis demonstrated that tumor histologic features and ALP flare were significant prognostic indicators for survival. CONCLUSIONS: The results of the present study suggest that the tumor histologic features and the ALP flare are significant prognostic indicators for survival in patients with metastatic prostate cancer treated with endocrine therapy.

Adenocarcinoma↗

PubMed2000

Prostate specific antigen adjusted for transition zone volume: the most powerful method for detecting prostate carcinoma.

BACKGROUND: Several methods for the identification of patients with prostate carcinoma have been proposed to enhance the clinical usefulness of prostate specific antigen (PSA). However, it remains unclear which method is superior in practical use. The authors attempted prospectively to identify the most powerful method with which to detect prostate carcinoma, especially among patients with intermediate PSA levels. METHODS: Between October 1997 and August 1999, systematic sextant biopsies were performed on 281 patients, including 147 with PSA levels between 4.1 ng/mL and 10.0 ng/mL. The clinical values of PSA, the free PSA to total PSA ratio (free/total PSA ratio), alpha-1-antichymotrypsin-PSA complex (PSA-ACT), the calculated derivatives, PSA density (PSAD), and PSA density of the transition zone (PSATZD) for the detection of prostate carcinoma were compared by using receiver operating characteristic (ROC) curves and logistic regression analyses. RESULTS: According to ROC curve analysis, PSATZD had the greatest area under the curve in the overall patient population and in patients with intermediate PSA levels. In patients with intermediate PSA levels, at the sensitivity of 90%, PSATZD would have prevented unnecessary biopsies in 68 of 117 patients who were without prostate carcinoma, whereas PSA, free/total PSA ratio, and PSA-ACT would have prevented unnecessary biopsies in 25, 28, and 25 patients, respectively. Stepwise logistic regression analysis showed that PSATZD and findings on digital rectal examination were significant independent predictors. CONCLUSIONS: PSATZD had the most useful validity in the differentiation between prostate carcinoma and benign prostatic enlargement in the overall patient population and in patients with intermediate PSA levels.

Aged↗

PubMed2000

Intravesical and intravenous therapy of human bladder cancer by the herpes vector G207.

G207, a conditionally replicating herpes vector, efficiently kills human bladder cancer cells in vitro. To evaluate the therapeutic potential of G207, we have established three in vivo models similar to the clinical situation. In vivo, G207 was intraneoplastically, intravesically, or intravenously inoculated in nude mice. Intraneoplastic inoculation into subcutaneous tumor caused significant tumor growth inhibition. Intravesical inoculation of G207 also caused decreased tumor growth in an orthotopic human bladder cancer model. Furthermore, multiple intravenous inoculation markedly inhibited subcutaneous tumor growth. These results suggest that intravesical therapy with G207 is effective for localized bladder tumor, especially for carcinoma in situ (CIS), and intravenous therapy with G207 is promising for invasive or metastasized bladder tumor.

Animals↗

PubMed2000

Chiral discrimination with regioselectively substituted cellulose esters as chiral stationary phases

Four kinds of cellulose derivatives, including two regioselectively substituted cellulose esters (6-O-acetyl-2,3-di-O-benzoyl cellulose and 2,3-di-O-acetyl-6-O-benzoyl cellulose), were synthesized so that the effects of their functional group distribution on their chiral discrimination ability could be examined. The degree of substitution by functional groups appeared to have a critical effect on the separation in most cases, but the type of the functional group at the C-6 position also significantly influenced chiral discrimination when a series of neutral arylalcohol derivatives were used as racemates. Copyright 2000 Wiley-Liss, Inc.

Journal Article↗

PubMed2000

Autocrine growth promotion by multiple hematopoietic growth factors in the established renal cell carcinoma line KU-19-20.

Increasing evidence suggests that paraneoplastic syndrome may be mediated by tumor-related cytokine release, although the specific factors involved remain to be clearly defined. The cancer cells used in the present study were obtained from a 67-year-old man with metastatic renal cell carcinoma in the subcutaneous space who demonstrated marked leukocytosis (37,800/mm3). The primary tumor of the kidney was pathologically diagnosed as renal cell carcinoma consistent with the sarcomatoid type. On microscopic observation, the cultured cells exhibited an epithelial appearance with vacuole formation in their cytoplasm. Ultrastructural observations revealed relatively marked microvilli and a tight junction. Significant amounts of GM-CSF, G-CSF, IL-6, and IL-8 concentrations in the culture media were identified by an enzyme-linked immunosorbent assay. Reverse transcriptase polymerase chain reaction (RT-PCR) significantly exhibited marker protein m-RNA expression in cancer cells. In addition, GM-CSF receptor and IL-6 receptor mRNA expression was also demonstrated by RT-PCR. The administration of both IL-6 and GM-CSF induced cell-proliferation activities estimated by both [3H]-thymidine and bromodeoxyuridine labeling. Anti-IL-6 antibody and anti-GM-CSF antibody neutralized the enhanced proliferative activities generated by these cytokines. Our findings indicate that the established renal cancer cell line can be demonstrated by both the production of multiple cytokines and by their promotion of autocrine growth. These cells are thus considered to be useful as an effective model for multipotent differentiated renal cell carcinoma, as well as for studying the mechanisms of action of autocrine growth.

Aged↗

PubMed2000

Current management of incidentally discovered adrenal masses, with a review of Japanese literature.

It is becoming increasingly common to discover adrenal masses incidentally on radiologic imaging studies. We herein present our experience with 61 cases of incidentally discovered and surgically removed adrenal incidentalomas, including 11 pheochromocytomas. Only four were adrenocortical carcinomas. A review of the literature, including Japanese journals, for the prevalence of incidentantally discovered adrenal mass, their differential diagnosis and management are discussed.

Adenoma↗

PubMed2000

Urinary steroid profile in adrenocortical tumors.

Determination of the urinary steroid profile has been proposed as a sensitive tool for diagnosing adrenocortical tumors. The urinary steroid profiles were determined for patients with adrenocortical tumors. Urinary steroids were extracted, derivatized to form methyloxime-trimethylsilyl ether and analyzed by gas chromatography/mass spectrometry. Patients with adrenal adenomas from primary hyperaldosteronism had increased metabolites of 18-hydroxycorticosterone and aldosterone, and those with Cushing's syndrome had elevated excretion of 11 -deoxycortisol, cortisol, 18-hydroxycortisol, and cortisone metabolites. In patients with adrenocortical carcinomas, increased levels of metabolites of 11-deoxycortisol or 33-hydroxy-5-ene steroids were observed. The urinary steroid profiles of adrenal adenomas and adrenocortical carcinomas were quite different, suggesting the diagnostic validity for discriminating malignant from benign diseases.

Adenoma↗

PubMed2000

Application of conditionally replicating herpes vector for gene therapy treatment of urologic neoplasms.

Herpes vector has been widely used for experimental gene therapy. We herein review the strategies of such therapy for the treatment of urologic neoplasms. Most experimental studies of genetically altered viruses have employed replication-incompetent vectors. However, such viruses are unable to infect additional cells subsequent to the initial infection event. Therefore, this strategy has relied heavily on the bystander effect because a large number of noninfected tumor cells remain. Conditionally replicating herpes vector G207 has been developed in order to overcome potential problems of safety and tumor specificity for human use. It has been used to treat malignant brain tumors because of its neural tropism. In the last few years, applications of G207 for non-neural tumors have been reported. Because G207 may be useful for the treatment of urologic malignant tumors, we evaluated the antitumor effect against several types of tumor cells both in vitro and in vivo. Our data suggest that G207 may be applicable for the treatment of urologic malignant tumors.

Animals↗

PubMed2000

Autolysis during in vitro tracheary element differentiation: formation and location of the perforation.

Tracheary elements differentiated from isolated Zinnia: mesophyll cells were observed at various times of culture under a scanning electron microscope. Perforation occurred on the primary wall at one of the longitudinal ends in single tracheary elements. In double tracheary elements, which both of two cells derived from a single cell differentiated into, the pore opened on the primary walls both at the junction of the two tracheary elements and at a longitudinal end of one of the two tracheary elements. These results suggest not only that a single tracheary element has its own program to form a perforation at one end without being affected by neighboring cells, but also that isolated cells indeed hold some traces of polarity and cell-cell communication.

Apoptosis↗

PubMed2000

Developing an ATOD prevention campaign for Asian and Pacific Islanders: some considerations.

This article provides an overview of the Asian and Pacific Islander (API) populations in the United States as it relates to developing targeted alcohol, tobacco, and other drug (ATOD) prevention media. Although APIs represent several ethnic subgroups, many API communities face the same risk factors including pressure on youth to achieve, immigration and acculturation stressors, shame and denial in addressing substance abuse, and racism and discrimination. The authors recommend that media prevention campaigns targeting API communities emphasize cultural and family strengths and the active involvement of parents. The article concludes with an introduction to eight API communities in the United States.

Asian↗

PubMed2000

Characteristics of alcohol consumption, correlates of alcohol misuse among Korean American adolescents.

There is scant research on alcohol and other drug use among Asians and Pacific Islanders living in the United States. In particular, there are no studies on alcohol consumption patterns among Korean American adolescents. This study provides new information on alcohol use for a population that has not been extensively studied. Descriptive analyses reveal that alcohol misuse does occur among Korean American adolescents. Results from logistic regression indicate that alcohol misuse among Korean American adolescents is influenced by the social variables found to affect use among other ethnic groups. For Whites, psychological variables (depression, self-esteem), perceived prejudice, and feeling safe where one lives explained variance beyond social influences. These findings support the contention that there are similarities in the social milieu of alcohol use among all adolescents in the United States. However, our data indicate that psychological forces provide additional influences on White alcohol misuse. Implications of our findings are discussed.

Adolescent↗

PubMed2000

[A case of metanephric adenoma treated with partial nephrectomy].

A 32-year-old female presented with a right renal mass detected by abdominal ultrasound examination at a routine medical check up. Computed tomography scans and magnetic resonance images revealed a solid tumor in the upper pole of the right kidney measuring 1.5 cm in diameter. Partial nephrectomy was performed on suspicion of the renal cell carcinoma. Histologically, the tumor is composed of small, uniform, epithelial cells with scant cytoplasm and hyperchromatic round nuclei that formed a tubular or glomerular-like structure. The histological diagnosis was metanephric adenoma.

Adenoma↗