Biomedical subjects

Y Fukabori

Publications and source records attributed to Y Fukabori.

52 records · Page 3Linked to original sources

PubMed1992

Expression and transforming activity of a variant of the heparin-binding fibroblast growth factor receptor (flg) gene resulting from splicing of the alpha exon at an alternate 3'-acceptor site.

Splicing at an alternate 3'-acceptor site results in deletion of a CCCAG in the 5'-sequence of the exon coding for the NH2-terminal immunoglobulin-like disulfide loop of the heparin-binding fibroblast growth factor receptor (flg) alpha isoform. The result is an in-frame stop codon 138 base pairs after the first flg consensus translational initiation site. The next more favorable site predicts the same two loop intracellular receptor isoform, gamma, which was predicted from two different human cDNAs that arise by alternate use of two exons at the same site. Although expressed in normal tissue, the gamma mRNA is increased in rat prostate tumors and confers ability of anchorage-dependent cells expressing non-secreted heparin-binding fibroblast growth factors to grow in soft agar.

Amino Acid Sequence↗

PubMed1992

Inhibition of 3 alpha-hydroxysteroid oxidoreductase and 5 alpha-reductase activity by antiandrogens and indomethacin in the rat prostate.

We studied the effects of antiandrogens in vitro on inhibition of 3 alpha-hydroxysteroid oxidoreductase (3 alpha-HSOR) and 5 alpha-reductase activities in the rat prostate. Kinetic and inhibition experiments were analyzed by thin layer chromatography. Cyproterone acetate (CA), chlormadinone acetate (CMA), and TZP-4238 (TZP), which is more potent than other antiandrogens, were used as inhibitors and were compared with indomethacin IND, which is a recognized 3 alpha-HSOR inhibitor. The IC50S of CA, CMA, IND, and TZP for 3 alpha-HSOR reductase in cytosol were about 5, 10, 10, and 100 microM, respectively, and inhibition was competitive. The IC50 of IND for 3 alpha-HSOR reductase in microsomes was 20 microM. The IC50S of other inhibitors were > 100 microM, and inhibition was noncompetitive. The IC50S of CA, CMA, IND, and TZP for 3 alpha-HSOR oxidase in cytosol were > 100 microM, and inhibition was competitive or noncompetitive. Inhibition of 3 alpha-HSOR oxidation was not observed in microsomes. The difference between these inhibition patterns suggests that there may be 4 isoenzymes in rat prostatic tissue. The IC50S of MK-906, CMA, and TZP for 5 alpha-reductase in prostate homogenate were about 0.01, 200, and 200 microM, respectively.

3-Hydroxysteroid Dehydrogenases↗

PubMed1992

Effects of the new steroidal antiandrogen TZP-4238 on hormone-induced canine prostatic hyperplasia.

The effects of the new steroidal antiandrogen TZP-4238 on hormone-induced canine prostatic hyperplasia (BPH) were studied in comparison with those of chlormadinone acetate (CMA), a steroidal antiandrogen used in Japan. One- to 2-year-old beagle dogs were castrated and administered 75 mg/week of androstanediol (A-diol) plus 0.75 mg/week of estradiol (E2) for 25 weeks. These dogs were treated orally with placebo, 0.5 mg/kg/day of TZP-4238, 0.1 mg/kg/day of TZP-4238, and 2.5 mg/kg/day of CMA, respectively, for 21 weeks after 4 weeks treatment with A-diol plus E2. Treatment with 0.5 mg/kg/day of TZP-4238 or 2.5 mg/kg/day of CMA suppressed prostatic growth, and treatment with 0.1 mg/kg/day of TZP-4238 suppressed prostatic growth slightly. Treatment with 0.5 mg/kg/day of TZP-4238 decreased 5 alpha-reductase activity, DHT content, and nuclear androgen receptor (AR) content in the prostate, and treatment with 0.1 mg/kg/day of TZP-4238 or 2.5 mg/kg/day of CMA also decreased or tended to decrease these parameters. In conclusion, TZP-4238 and CMA were effective in inhibiting the growth of hormone-induced canine BPH, and TZP-4238 was at least 5 times more potent than CMA. TZP-4238 inhibited prostatic growth by decreasing prostatic androgen content and the androgen-AR complex. TZP-4238 decreased 5 alpha-reductase activity by prevention of the androgen action described above.

Androstane-3,17-diol↗

PubMed1992

Potential role of HBGF (FGF) and TGF-beta on prostate growth.

We review in this paper the role of heparin-binding growth factor (HBGF*) or fibroblast growth factor (FGF*), rat prostate cancer cells produce TGF-beta, IGF-II* and OGF*. Of these growth factors, TGF-beta and unknown labile factor with 19 kDa are the most probable candidates responsible for osteoblastic bony metastasis of prostate cancer. In vitro experiments suggest that TGF-beta modulates cell detachment of prostate cancer cells together with nutritional factors. HBGF-dependent growth of the prostate tumor epithelial cells is free from inhibition by TGF-beta, whereas normal prostate epithelial cells are sensitive to TGF-beta inhibition. Transfection experiments suggest that HBGF-2 (basic FGF) might be closely related to the malignant growth of prostate cancer, in addition to tumor angiogenesis.

Animals↗

PubMed1992

Heparin-binding keratinocyte growth factor is a candidate stromal-to-epithelial-cell andromedin.

The growth of isolated epithelial and stromal cells from both androgen-dependent normal rat prostate and an androgen-responsive model rat prostate tumor is androgen-independent. When added to co-cultures of epithelial and stromal cells separated by a semipermeable membrane, androgen stimulated epithelial cell growth without an effect on stromal cell growth. Northern blot and nuclease protection analysis of mRNA revealed that stromal cells specifically expressed an androgen-sensitive secreted member of the heparin-binding fibroblast growth factor family [keratinocyte growth factor (KGF)/fibroblast growth factor-7]. KGF was mitogenic for epithelial cells, but not for stromal cells. Epithelial cells expressed specifically a splice variant of the bek receptor gene that specifically binds KGF. Expression of the bek receptor gene in stromal cells was undetectable by Northern blot and nuclease protection analyses. The results suggest that stromal cell-derived KGF has the properties of an andromedin, which mediates the indirect control of epithelial cell proliferation by androgen through a directional stromal-to-epithelial cell paracrine mechanism.

Animals↗

PubMed1992

[Endocrine environment of benign prostatic hyperplasia--relationships of sex steroid hormone levels with age and the size of the prostate].

To determine the influence of endocrine factors on benign prostatic hyperplasia (BHP), the levels of three sex steroid hormones i.e., total testosterone (Total-T), free testosterone (Free-T) and estradiol (E2), were measured in serum of healthy 154 men. Their ages ranged from 18 to 91 years old. In 59 men, prostatic size was estimated by digital examination and was subdivided into three groups: smaller than or equal to walnut size, small hen's egg size and equal to or larger than hen's egg size. Firstly, relationships of sex hormone levels with age were studied. There was a slight decrease in Total-T over 60 years old, a significant decrease in Free-T, and no change in E2 with age. Thus, E2/Total-T and E2/Free-T ratio increased significantly after middle-age. Secondly, relationships of hormone levels with prostatic size were studied. In the larger prostate group, a significantly lower level of Total-T and significantly higher level of E2 were detected. But there was no difference in Free-T. Thus, the prostatic size was correlated positively with E2 level, E2/Total-T and E2/Free-T ratio. These suggest that the endocrine environment tended to be estrogens-dominant with age, in particular, after middle-age, and that patients with large prostates have more estrogens-dominant environments. We conclude that estrogens are key hormones for the induction and the development of BPH.

Adolescent↗

PubMed1991

[Estrogen formation in the central nervous system and characteristics of aromatase of rat hypothalamus].

Estrogen formation from androst-4-ene-3,17-dione and its kinetics were studied using microsomes from rat hypothalamus. [4-14C] androst-4-ene-3,17-dione and a homogenate of rat hypothalamus were incubated in the presence of NADPH at 37 degrees C for 3 hrs. The estrogen fraction was extracted from the incubation mixture with ethyl acetate, purified by column chromatography on Sephadex LH-20 and Bond Elut C18, and separated into estrone and estradiol fractions by HPLC. In analysis of the trimethylsilyl (TMS) derivatives of each fraction by gas chromatography-mass spectrometry (GC-MS), the molecular ion peak of the estrone fraction appeared at m/z 344, within 2 amu of that for the TMS derivative of natural estrone. The retention time of the estrone fraction derivative was 11.6 min, the same as that of natural estrone. 14C-estrone was thus concluded to be biosynthesized from [4-14C]-androst-4-ene-3,17-dione in rat hypothalamus. The kinetics of the aromatase of rat hypothalamic tissue was studied by measuring 3H2O released from [1 beta-3H]-androst-4-ene-3,17-dione and estrone as the estrogen product by measured gas chromatography selected ion monitoring (GC-SIM). High correlation was found between 3H2O release and estrone measured by GC-SIM (r = 0.97). Aromatase activity was linear with respect to incubation time and quantity of tissue. Km and Vmax were 30.3 nM and 7.98 fmol estrogen/h/mg of wet tissue, respectively. 4-hydroxyandrostenedione (4-OH-A) suppressed the activity of aromatase in both rat hypothalamic and human placental tissue in a concentration-dependent manner. Polyclonal IgG to human placental aromatase also suppressed aromatase activity of human placental tissue, but only slightly suppressed that of rat hypothalamus. The molecular structure of aromatase in rat hypothalamus was thus concluded to differ from that in human placenta.

Androstenedione↗

PubMed1990

[Multilocular cystic renal cell carcinoma: a report of 2 cases].

We report 2 cases of renal cell carcinoma which rarely occur as multilocular cystic masses. By means of echography, both cases were discovered as abnormal shadows occupying the middle portion of the left kidney. Using computerized tomography and selected renal arteriography, we tried to obtain an accurate diagnosis, but few specific malignant findings were gained. Finally, we made the histopathological diagnosis. In addition, we concluded by careful pathological examination that they were multilocular cystic growths. It was difficult to differentiate them preoperatively from multilocular cystic nephroma. Both patients are still alive without tumor recurrence.

Adult↗

PubMed1989

[Post-operative intra-arterial chemotherapy in patients with malignant bone and soft tissue tumors].

Fourteen patients with bone and soft tissue sarcoma were treated with post-operative intra-arterial chemotherapy. Three drugs (Adriamycin, vincristine, carboquone or THP-adriamycin, cisplatin, vindesine) or two drugs (cisplatin, vindesine) were used post-operatively for patients with local recurrence, patients with poor response of pre-operative intra-arterial chemotherapy or patients with intra-lesional or marginal surgical margin. Of the 14 patients treated with post-operative intra-arterial chemotherapy, 8 (57.1%) were continuously disease-free (7.1%) were disease-free after treatment of lung metastasis, 2 (14.3%) had a local recurrence and/or multiple distant metastasis, and 3 (21.4%) died with multiple distant metastases. The rate of local recurrence was 14.3%. The Kaplar-Meier disease free survival curves showed 59.6%). Evaluation of limb function were excellent or good in 9 (69.2%) of 13 patients treated with limb-saving procedures.

Adolescent↗

PubMed1988

[Determination of 5 alpha-androstane-3 alpha, 17 beta-diol in human serum by GC-SIM and influence of age-associated change].

5 alpha-Androstane-3 alpha, 17 beta-diol (A3 alpha diol) is a potent androgen, and is an end product of testosterone. Many authors measured A3 alpha diol levels in human plasma by various methods, but the levels of this steroid were very dissimilar. In order to validate such values, it was measured by gas chromatography-selected ion monitoring (GC-SIM) in this study. A3 alpha diol, 5 alpha-Androstane-3 beta, 17 beta-diol (A3 beta diol) and Testosterone (T) in human peripheral serum were measured by GC-SIM at the same time. The TFA-derivatives of these compounds were analyzed after purification of the serum extract by Sephadex LH-20 microcolumn chromatography. The sensitivity was good: (16.7 pg/ml: A3 alpha diol, 26.7 pg/ml: A3 beta diol). The precision (CV = 2.75%: A3 alpha diol, 3.11%: A3 beta diol) and the accuracy were better than ever reported. Serum A3 alpha diol was measured in 131 healthy men aged 15-81 years and 5 healthy women aged 25-60 years. There were remarkable differences between individuals in the serum levels of A3 alpha diol, but the levels in male serum (greater than 20y) showed a significant negative correlation with age (r = -0.560, p less than 0.01). When these healthy men were classified into three age groups of 20-39, 40-59 and 60-79 years, the values (mean +/- SD) for serum A3 alpha diol were 189.3 +/- 77.7 (n = 20), 127.9 +/- 59.5 (n = 28), and 94.9 +/- 52.9 (n = 73) pg/ml, respectively. There were significant differences between the levels of this steroid in all age groups (p less than 0.01). There was a weak but significant correlation between serum A3 alpha diol and T levels (r = 0.3235, p less than 0.01) in healthy men (25-77 years, n = 77). Determination of serum A3 alpha diol was influenced by age. The number of samples strongly influenced the decision of mean value of A3 alpha diol levels. These results suggested that these factors had to be made obvious when this steroid was studied.

Adolescent↗

PubMed1987

Plasmodium berghei: a study of globinolytic enzyme in erythrocytic parasite.

An acid protease of Plasmodium berghei (NK 65) was extracted from parasite lysate and purified by means of gel filtration followed by DEAE-sephadex column chromatography. The enzyme showed especially high activity to degrade hemoglobin. The pH optimum of the purified enzyme was 3.2, Km value was 0.012 mM. Molecular weight of the enzyme was estimated by gel chromatography as being 18,000-20,000. The enzyme activity was specifically inhibited by pepstatin, one of the peptide aldehyde protease inhibitors. These features of the enzyme were similar to those of acid protease taken from Dirofilaria immitis which also metabolizes hemoglobin as the major nutrient source.

Animals↗

PubMed1987

[Transrectal longitudinal ultrasonography of the prostate by electronic linear scanning (1)].

Transrectal longitudinal ultrasonography of the prostate was done for 20 patients with prostatic diseases, 12 with benign prostatic hypertrophy, 6 with bladder neck contracture, and 2 with chronic prostatitis. The intravesical protrusion of the prostate and the opening of the bladder neck, which can be easily recognized by this method, were discussed in relation to dysuria, using subjective symptoms, residual urine, and uroflowmetry (peak flow rate) as parameters. The former was slightly correlated to dysuria, and the latter was definitely correlated to dysuria.

Aged↗

PubMed1986

[The regulation system of brain aromatase activity; effects of androgens on hypothalamic aromatase in the male rat].

Recently, some studies have found the greatest aromatase activity in brain areas associated with sexual differention and sexual behavior, namely the hypothalamic and limbic structures. We studied the regulation of aromatase activity in the hypothalamic area of male rats, using a sensitive in vitro assay which measures the amount of 3H2O formed by tissue homogenates during the conversion of [1 beta-3H] androstenedione to estrogen. After castration, hypothalamic aromatase activity was significantly decreased (P less than 0.01), and seminal vesicle (SV) and prostate (PR) weights were also significantly decreased (P less than 0.01). Castrated male rats were given testosterone (T), 5 alpha-dihydrotestosterone (DHT), 5 alpha-androstane-3 alpha, 17 beta-diol (A3 alpha), 5 alpha-androstane-3 beta and 17 beta-diol(A3 beta) in various doses (200-1000 micrograms/day) for 10 days, and were given 600 micrograms/day T, DHT, A3 alpha and A3 beta for various durations (1-10 days). We found that T, DHT and A3 alpha but not A3 beta reversed the effects of castration on the hypothalamic aromatase activity. The order of this reversible effect of androgens was as follows: T greater than or equal to DHT greater than A3 alpha. T, DHT, A3 alpha and A3 beta increased SV and PR weights, and the order of this effect was as follows: DHT greater than T greater than A3 alpha much greater than A3 beta. We administered the antiandrogen (flutamide) to intact male rats (8 mg/day for 6 days). Flutamide decreased hypothalamic aromatase activity at the same level as that of castrated rats. Likewise, administration of both flutamide and T to castrated rats blocked the T-induced increase in hypothalamic aromatase activity and accessory sexual organ weight. From these results, we suggest that T, DHT and A3 alpha regulated hypothalamic aromatase activity, that T was the most effective of the androgens, and that was different from peripheral androgen target organs.

Androgens↗

PubMed1986

[Studies on estramustine-binding protein in the human prostate].

In the present study, size exclusion HPLC was used to analyse the properties of Estramustine-binding protein (EMBP) in the cytosol of human benign prostatic hypertrophy (BPH). The typical size exclusion HPLC separation profile of 3H-Estramustine-labelled cytosol of BPH showed four radioactive peaks that corresponded to the V0, 250K, 68K and 45K protein regions. The specific binding protein for Estramustine is contained mainly in the 250K protein region and in part in the V0 region. In the presence of sodium molybdate, the specific Estramustine binding to a 250K protein was increased to a level which was about 2.5 times as much as the value in the absence of sodium molybdate. The specific Estramustine binding to a 250K protein under the condition of no DCC treatment and the addition of sodium molybdate was 600% of the value obtained under the condition of DCC treatment and no addition of sodium molybdate. These results suggested that sodium molybdate stabilized the specific Estramustine-binding activity to a 250K protein and that specific Estramustine binding to a 250K protein seemed to be weaker than the binding of androgen to androgen receptor.

Carrier Proteins↗

PubMed1984

[The metabolism of testosterone in the central nervous system (1). Analysis of testosterone metabolites in the anterior pituitary and hypothalamus using gas chromatography-mass spectrometry (GC-MS), and subcellular localization of testosterone converting enzyme].

The aim of this study was to identify accurately the structure of testosterone metabolites in the anterior pituitary and hypothalamus for the investigation of the mechanism of androgen action in the central nervous system. Tissue homogenate and cellular fraction of male rat anterior pituitary and hypothalamus were incubated with testosterone-4-14C and testosterone-19-CD3 (14C/D3 = 1) in the presence of NADH and NADPH. The incubation media were extracted, and they were separated using thin layer chromatography (TLC). Using autoradiogram of TLC, four main radioactive fractions were found on the TLC. The TFA or TMS derivatives of every fraction were analyzed using GC-MS. The main metabolites in the anterior pituitary were identified as 5 alpha-androstan-17-ol 3-one; androst-4-ene-3, 17-dione, 5 alpha-androstane-3 alpha, 17 beta-diol, 5 alpha-androstane-3 beta, 17 beta-diol, androst-4-ene-3 alpha, 17 beta-diol and androst-4-ene-3 beta, 17 beta-diol. The result in the hypothalamus was the same as that in the pituitary. The subcellular localization of metabolites in the anterior pituitary was as follows: 5 alpha-androstan-17-ol-3-one, 5 alpha-androstane-3 alpha, 17 beta-diol and 5 alpha-androstane-3 beta, 17 beta-diol were found in microsome; 5 alpha-androstane-3 alpha, 17 beta-diol and androst-4-ene-3 alpha, 17 beta-diol were found in soluble fraction. The result in the hypothalamus was the same as that in the pituitary.

Androstane-3,17-diol↗

PubMedDate not supplied

Gene expression profiles in human BPH: utilization of laser-capture microdissection and quantitative real-time PCR.

Human benign prostatic hyperplasia (BPH) nodules consist of epithelium and stroma that have different properties functionally as well as morphologically. To investigate the molecular profiles of the prostate gland, separate examination of these components are necessary. Laser-capture microdissection (LCM) is a newly-developed device which enables one to dissect interesting parts of tissues under the microscope. In the current work we studied the gene expression profiles of prostatic epithelium and stroma using LCM. Androgen receptor (AR), estrogen receptor alpha and beta (ER alpha and ER beta), progesterone receptor (PR) and 5-alpha reductase type I and type II (5alphaR I and 5alphaR II) gene expressions were studied by RT-PCR. All of these genes were expressed both in the epithelium and stroma. Furthermore, AR transcript was quantified by quantitative real-time PCR. AR transcript ranged from 302 to 1440 copies per 10(5) GAPDH copies and from 257 to 3223 copies per 10(5) GAPDH copies in the epithelium and stroma, respectively. Thus, LCM and quantitative real-time PCR are powerful tools for molecular analysis of heterogeneous tissues including prostate gland.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗