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Biomedical subjects

F Satoh

Publications and source records attributed to F Satoh.

At least 19 recordsLinked to original sources
PubMed2002

Fishing for bioactive substances from scorpionfish and some sea urchins.

Venom proteins from the dorsal spine of two scorpionfish, Hypodytes rubripinnis and Synanceia verrucosa were assayed for mitogenicity and cytotoxicity. The two venoms had both mitogenic and cytotoxic activity on murine splenocytes and murine P388 leukemic cells. In H. rubripinnis, the second gel chromatographic fraction showed cytotoxic activity on P388 leukemic cells. On native PAGE, the glycoprotein isolated by concavalin A sepharose chromatography appeared to have a molecular mass of 110 kDa. In addition, two D-galactose-binding lectins (SUL-I and SUL-II) and a heparin-binding lectin (TGL-I) were purified from the globiferous pedicellariae of the toxopneustid sea urchins, Toxopneustes pileolus and Tripneustes gratilla, respectively. SUL-I (Nakagawa et al., 1999a) had mitogenic activity and cytotoxic activity but SUL-II and TGL-I did not. SUL-I did not show sequence homology to SUL-II. A hemolytic lectin with a molecular mass of 29 kDa was isolated from the coelomic fluid of T. gratilla. The hemolytic activity of the lectin was dependent on Ca2+ concentration and inhibited by lactose. The present results suggest that some species of scorpionfish and sea urchins may be novel sources for biologically active substances such as anti-tumor compounds or new lectins.

Agglutination↗
PubMed2001

Effects of surface soil removal on dynamics of dissolved inorganic nitrogen in a snow-dominated forest.

To clarify the effect of vegetation and surface soil removal on dissolved inorganic nitrogen (N) dynamics in a snow-dominated forest soil in northern Japan, the seasonal fluctuation of N concentrations in soil solution and the annual flux of N in soil were investigated at a treated site (in which surface soil, including understory vegetation and organic and A horizons, was removed) and control sites from July 1998 to June 2000. Nitrate (NO3-) concentration in soil solution at the treated site was significantly higher than that of the control in the no-snow period, and it was decreased by dilution from melting snow. The annual net outputs of NO3- from soil at the treated site and control sites were 257 and -12 mmol m(-2) year(-1), and about 57% of the net output at the treated site occurred during the snowmelt period. NO3- was transported from the upper level to the lower level of soil via water movement during late autumn and winter, and it was retained in soil and leached by melt water in early spring. Removing vegetation and surface soil resulted in an increase in NO3- concentration of soil solution, and snowmelt strongly affected the NO3- leaching from treated soil and the NO3- restoration process in a snow-dominated region.

Ammonia↗
PubMed2001

Role of urotensin II in patients on dialysis.

Urotensin II is a potent vasoconstrictor, which also has some vasodilatory properties. We investigated its expression in various tissues and in the plasma of patients with renal dysfunction. Plasma concentrations of urotensin II-like immunoreactivity were 2-fold higher in patients not on dialysis and 3-fold higher in those on haemodialysis thanin healthy individuals. Messenger RNA encoding theurotensin II precursor and the urotensin II receptor precursor were expressed in various human tissues. The peptidemight act as an important regulator in the cardiovascularand renal systems. Urotensin II antagonists could, therefore, be useful in the treatment of diseases affecting theseorgans.

Adult↗
PubMed2001

Immunoreactive orexin-A in human plasma.

Orexin-A and orexin-B are newly discovered neuropeptides which are implicated in feeding behavior and arousal state. We studied immunoreactive(IR)-orexin-A concentrations in human plasma by radioimmunoassay. IR-orexin-A concentrations in plasma obtained from 17 healthy subjects in the morning were 1.94 +/- 0.24 pmol/liter (mean +/- SEM). IR-orexin-A levels in the plasma obtained at night were not significantly different from those obtained in the morning in 9 female subjects. The HPLC analysis of the plasma extract showed two immunoreactive peaks; one peak eluting in an identical position to synthetic orexin-A, and one eluting earlier. This study has shown for the first time the presence of orexin-A in human plasma.

Adult↗
PubMed2001

Adrenomedullin and its receptor complexes in remnant kidneys of rats with renal mass ablation: decreased expression of calcitonin receptor-like receptor and receptor-activity modifying protein-3.

Adrenomedullin (AM) has vasodilator and diuretic actions, similarly to natriuretic peptides. AM receptor complexes are composed of calcitonin receptor-like receptor (CRLR) and receptor-activity modifying protein-2 (RAMP2), or CRLR and RAMP3. We aimed to know whether gene expression of AM and AM receptor complexes are regulated in kidneys under pathophysiological conditions. Expression of AM, RAMP2, RAMP3 and CRLR mRNA was studied in the remnant kidney of rats with renal mass ablation using competitive quantitative RT-PCR techniques. Partial cloning was performed to determine the rat RAMP3 nucleotide sequence. In normal rat kidneys, expression levels of RAMP2, RAMP3, CRLR and AM mRNAs were 26.5 +/- 1.9 mmol/mole of GAPDH, 7.7 +/- 0.9 mmol/mole of GAPDH, 3.6 +/- 0.2 mmol/mole of GAPDH and 0.57 +/- 0.03 mmol/mole of GAPDH (mean +/- SE, n = 6), respectively. RAMP3 mRNA levels decreased significantly to about 50% and about 70% of control (sham-operated rats) 4 days and 14 days after 5/6 nephrectomy, respectively. CRLR mRNA levels also decreased significantly to about 30% and about 43% of control. Sodium intake restriction had no significant effects on the RAMP3 and CRLR gene expression. On the other hand, RAMP2 mRNA expression in the kidney was suppressed by sodium intake restriction regardless of nephrectomy, while RAMP2 levels in the remnant kidney were not significantly changed by 5/6 nephrectomy. Neither 5/6 nephrectomy or sodium intake restriction had any significant effects on the AM gene expression in the kidney. The present study showed that expression of mRNAs encoding AM, RAMP2, RAMP3 and CRLR were differentially regulated in remnant kidneys of rats with renal mass ablation.

Adrenomedullin↗
PubMed2001

Autocrine expression of neurotrophins and their receptors in prostate cancer.

Previously, it has been demonstrated that the neurotrophins and their receptors are present in human prostate tissue, but neither their functional role nor localization is clearly understood. We studied the expression of neurotrophins and their receptors in prostate cancer. Between 1990 and 1999, 48 prostate cancer specimens were obtained from patients undergoing radical prostatectomy, of whom 25 received neoadjuvant hormonal therapy (NHT) and 23 were untreated. The specimens were analyzed immunohistochemically for neurotrophins (nerve growth factor, brain derived neurotrophic factor, neurotrophin 3, neurotrophin 4/5) and their receptors (TrkA, TrkB, TrkC, p75NTR). Immunohistochemical studies revealed that both benign and malignant prostate gland epithelial cells expressed the neurotrophins and their receptors to various degrees, but no obvious immunopositive reaction was observed in stromal cells. In benign epithelial cells, the neurotrophins were localized to secretory cells and the receptors were localized to basal cells. The neurotrophins, TrkA and TrkC were expressed to a similar extent in prostate cancer specimens obtained from patients both with and without NHT. In contrast, the expression of TrkB was down-regulated and the expression of p75NTR was up-regulated in prostate cancer after hormonal therapy. These findings suggest that neurotrophins are secreted by prostate cancer cells in an autocrine fashion. Neurotrophins may be involved, through their receptors, in the escape mechanism from cell death after androgen depletion found in prostate cancer.

Aged↗
PubMed2001

Expression of melanin-concentrating hormone receptor messenger ribonucleic acid in tumor tissues of pheochromocytoma, ganglioneuroblastoma, and neuroblastoma.

Expression of melanin-concentrating hormone (MCH) receptor messenger ribonucleic acid (mRNA) was studied by RT-PCR and Northern blot analysis in human brain; pituitary; adrenal glands; tumor tissues of adrenal tumors, ganglioneuroblastomas, and neuroblastomas; and various cultured tumor cell lines. RT-PCR analysis showed that MCH receptor mRNA was widely expressed in brain tissues, pituitary, normal portions of adrenal glands (cortex and medulla), tumor tissues of adrenocortical tumors (12 of 13 cases), pheochromocytoma (all 7 cases), ganglioneuroblastoma (1 case), neuroblastoma (all 5 cases), and various cultured tumor cell lines (6 of 7 cell lines), including 2 neuroblastoma cell lines. Northern blot analysis showed the expression of MCH receptor mRNA ( approximately 2.4 kb) only in the tumor tissues of 5 pheochromocytomas, 1 ganglioneuroblastoma, and 4 neuroblastomas, indicating that the expression levels of MCH receptor mRNA are much higher in these tumors than in the other tissues. These findings raised the possibility that MCH or MCH-like peptides may be related to the pathophysiology of these neural crest-derived tumors.

Adrenal Gland Neoplasms↗
PubMed2001

Neuroendocrine marker expression in thyroid epithelial tumors.

Tissue sections from 50 cases with thyroid tumors, composed of 11 follicular adenomas, 10 follicular carcinomas, 14 papillary carcinomas, 10 anaplastic carcinomas, and 5 medullary carcinomas, were immunohistochemically analyzed for representative neuroendocrine markers. Immunoexpression ratios of these neuroendocrine markers were as follows: Follicular adenomas, neuron-specific enolase (NSE)63.6%, synaptophysin (SynP) 45.5%, Leu7 27.3%, NCAM 45.5%, chromogranin A (CgA) 0%, SNAP25 0%; follicular carcinomas, NSE 90.0%, SynP 80.0%, Leu7 80.0%, NCAM 0%, CgA 0%, SNAP25 0%; papillary carcinomas, NSE 85.7%, SynP 78.6%, Leu7 100%, NCAM 7.0%, CgA 0%, SNAP25.0%; anaplastic carcinomas, NSE 10.0%, SynP 0%, Leu7 0%, NCAM 0%, CgA 0%, SNAP25 0%; medullary carcinomas, NSE 100%, SynP100%, Leu7 80.0%, NCAM 40.0%, CgA 100%, SNAP25 100%. The two follicular carcinomas, which were morphologically characterized by "insular" (or "alveolar") arrangements, showed distinct immunoexpression of NSE and SynP at the same time. By in situ hybridization (ISH), expression of mRNA for NSE was confirmed in cases with marked immunoexpression of NSE. Although no endocrine granules were found, our results suggested that a specific type of follicular carcinoma, i.e., insular variant, may be immaturely neuroendocrine-differentiated.

Adenocarcinoma↗
PubMed2000

Immunohistochemical analysis of GCDFP-15 and GCDFP-24 in mammary and non-mammary tissue.

BACKGROUND: Gross cystic disease fluid protein (GCDFP)-15, a major constituent protein in breast cysts, is known to be a marker of breast cancer, while the diagnostic value of GCDFP-24, a protein with a molecular weight of 24,000 daltons, has not been determined. The aim of this study was to elucidate the usefulness of GCDFP-24 for the differential diagnosis of breast cancer in combination with GCDFP-15 and to characterize the histologic features of GCDFP-24-positive breast cancer. METHODS: A total of 326 samples including non-neoplastic tissue and benign and malignant tumors from several anatomic sites were examined using commercially available monoclonal antibodies against GCDFP-15 and GCDFP-24. RESULTS: In non-mammary tissue, GCDFP-15 was detected in skin, salivary gland, bronchial gland, prostate and seminal vesicle, and GCDFP-24 was detected in apocrine glands and peripheral nerve. Thirty-seven (44.6%) and 22 (26.5%) samples of 83 breast cancers were positive for GCDFP-15 and -24, respectively. Combined assays of GCDFP-15 and -24 raised the positive rate to 50.6%. The markers were not detected in tumors originating from gastrointestinal tract, bronchopulmonary structures or the genitourinary system. Breast cancers positive for both GCDFP-15 and GCDFP-24 were of lower histologic grade according to Bloom & Richardson's scoring system (p < 0.05). CONCLUSION: Immunohistochemical analysis of GCDFP-24 in combination with GCDFP-15 expression was useful for definitive diagnosis of breast cancers, and the expression of these markers correlated with low grade breast cancer.

Apolipoproteins↗
PubMed2000

Orexin-A in the human brain and tumor tissues of ganglioneuroblastoma and neuroblastoma.

Regional distribution of orexin-A-like immunoreactivity in the human brain and pituitary, and the presence of orexin-A-like immunoreactivity in the tumor tissues of pheochromocytomas, ganglioneuroblastomas and neuroblastomas were studied by radioimmunoassay. Expression of orexin mRNA was studied by reverse transcriptase polymerase chain reaction (PCR) method. Orexin-A-like immunoreactivity was detected in every region of human brain, but not in the pituitary. The highest concentration of orexin-A-like immunoreactivity in the human brain was found in hypothalamus (17.8 +/- 4.3 pmol/g wet weight, mean +/- SEM, n = 7), followed by thalamus, medulla oblongata, and pons. Orexin-A-like immunoreactivity was detected in the tumor tissues of ganglioneuroblastoma and neuroblastoma, but not in the tumor tissues of pheochromocytoma. Reverse phase high performance liquid chromatographic analyses of the orexin-A-like immunoreactivity in the human brain extracts and neuroblastoma extracts showed a single immunoreactive peak, which was eluted in an identical position to synthetic human orexin-A. Orexin mRNA was expressed in the hypothalamus and in the tumor tissues of ganglioneuroblastoma and neuroblastoma. These findings suggest that orexin-A is produced in the hypothalamus and transported to various brain regions via axons. In addition, this study has shown for the first time the production of orexin-A by ganglioneuroblastomas and neuroblastomas.

Adrenal Gland Neoplasms↗
PubMed2000

Binding sites for melanin-concentrating hormone in the human brain.

Binding sites for melanin-concentrating hormone (MCH) in human brain were investigated and characterized by radioligand binding. Specific binding sites for MCH were present in every region of human brain (cerebral cortex, cerebellum, thalamus, hypothalamus, pons, and medulla oblongata) obtained at autopsy. alpha-Melanocyte stimulating hormone or ACTH was a poor inhibitor of (125)I-MCH binding (IC(50) 1 microM) compared with MCH (IC(50) = 0.3 +/- 0.07 nM, mean +/- SEM, n = 3). Scatchard plots of (125)I-MCH binding in human brain (thalamus) gave a dissociation constant of 0.2 +/- 0.06 nM and maximal binding of 5.8 +/- 0.3 fmol/mg protein (n = 3). These findings suggest that specific MCH binding sites that differ from the melanocortin receptors exist in human brain.

Adrenocorticotropic Hormone↗
PubMed2000

Characterization and distribution of prolactin releasing peptide (PrRP) binding sites in the rat--evidence for a novel binding site subtype in cardiac and skeletal muscle.

Prolactin releasing peptide (PrRP) was recently purified from bovine hypothalamus and binds to the orphan receptor, UHR-1. We examined the distribution and kinetics of (125)I-PrRP binding in rat tissues together with molecular characterization by chemical cross-linking and Northern blotting. In this study (125)I-PrRP binding showed specificity and rapid association and dissociation. Specific binding was found in membranes from rat tissues including brain (hypothalamus, medulla oblongata and cerebellum), pituitary, heart, soleus muscle, adipose tissue, kidney, adrenal gland, testis and small intestine. In hypothalamus, pituitary, heart and soleus competition analysis indicated only one class of binding site in each tissue. Binding affinity for PrRP (IC(50)) and binding site density (B(max)) respectively were 5.2+/-0.9 nM and 674+/-97 fmol mg protein(-1) in hypothalamus (n = 5), 1.4+/-0.6 nM and 541+/-126 fmol mg protein(-1) in pituitary (n = 3), 6.6+/-0.7 nM and 628+/-74 fmol mg protein(-1) in heart (n = 4) and 9.8+/-0.9 nM and 677+/-121 fmol mg protein(-1) in soleus muscle (n = 4). Analysis of (125)I-PrRP-binding site complexes by chemical cross-linking showed a binding site M(r) of 69,000 in hypothalamus and 41,000 in heart and soleus. Northern analysis of polyA(+) RNA from hypothalamus showed a 4.2 kb band as expected for UHR-1, but heart and soleus showed a 4.8 kb band. Taken together these results indicate that there may be different subtypes of PrRP binding sites in rat tissues which may differ from UHR-1.

Animals↗
PubMed2000

Comparative immunohistochemical analysis of developing kidneys, nephroblastomas and related tumors: considerations on their histogenesis.

Immunoperoxidase analysis was performed to evaluate the phenotypic expression of eight renal differentiation antigens in five nephroblastomas, one clear cell sarcoma of the kidney (CCSK), one rhabdoid tumor of the kidney (RTK), and four related tumors. A total of 19 fetal and pediatric kidneys, including two 6th-week mesonephric tissues, were comparatively studied. All the specimens were fixed in formalin and embedded in paraffin. Neural cell adhesion molecule (NCAM), a marker of the nephrogenic zone of the developing kidney, was consistently expressed in the epithelial and blastematous components of nephroblastomas of the common type. The epithelial components also commonly expressed NK1 and Leu 7 (CD57), and the findings may reflect that both were positive in immature proximal tubules directly differentiating from the NCAM-positive immature fetal tubuloglomerular buds. In two cases, the epithelial component was immunoreactive for CD10 and WT1 gene product (WT1-GP). Leu M1, epithelial membrane antigen and CA15-3 were only focally expressed in nephroblastomas. Rhabdomyoblasts in the stroma were positive for WT1-GP. CCSK was featured by the expression of NCAM and CD10. In RTK, focal epithelial differentiation was discerned, with focal positivity of WT1-GP and negativity of NCAM. In congenital mesoblastic nephroma, the stromal spindle cells were strongly immunoreactive for WT1-GP, while WT1-GP was not expressed in solitary multilocular cyst of the kidney. Pancortical nephroblastomatosis was featured by the diffuse subcapsular reappearance of immature metanephric tissue. Nephroblastomas and related conditions thus offer an adequate model for studying human nephrogenesis.

Adolescent↗
PubMed2000

Sarcomatoid carcinoma of the renal pelvis: a case report.

A case of sarcomatoid carcinoma of the renal pelvis is reported. A 72-year-old male was admitted with a chief complaint of right flank pain. Clinical imaging studies revealed marked dilation of the right renal pelvis caused by a tumor at the pyeloureteric region. Right nephrectomy was performed in June 1999. The 8.4 x 6.5 cm tumor was grossly polypoid in appearance and protruded into the renal pelvis. Histologically, sarcomatoid spindle cells predominated over the carcinomatous component (mainly transitional cell carcinoma, partly associated with squamous cell and adenocarcinoma components). Osteoclast-like CD68-positive multinucleated giant cells were scattered. The sarcomatoid component was immunoreactive for both cytokeratin and vimentin. Sarcomatoid cells negative for cytokeratin were also noted. In both the sarcomatoid and carcinomatous components, nuclear overexpression of p53 oncoprotein was confirmed. The histogenesis of sarcomatoid carcinoma of the renal pelvis is discussed.

Adenocarcinoma↗
PubMed2000

Expression of endothelin-1 and endothelin receptors in cultured human glioblastoma cells.

Production and secretion of endothelin-1 (ET-1) by a human glioblastoma cell line, T98G, were studied by radioimmunoassay and Northern blot analysis. Immunoreactive ET was detected in the culture medium of T98G (17.6 +/- 0.6 fmol/10(5) cells/24 h, mean +/- SEM, n = 5). Reverse-phase high-performance liquid chromatography (HPLC) of immunoreactive ET in the culture medium extract showed a single peak eluting in the position of ET-1. Northern blot analysis showed expression of ET-1 mRNA in T98G cells. Treatment with interferon-gamma decreased the expression of ET-1. Treatment with TNFalpha or interleukin-1beta (IL-1beta) increased the expression of ET-1. Furthermore, reverse transcriptase polymerase chain reaction (RT-PCR) showed expression of endothelin-A- and -B- (ET(A) and ET(B)) receptor mRNAs in T98G glioblastoma cells. These findings indicate that glioblastoma cells produce and secrete ET-1, and express ET receptor mRNAs. ET-1 secreted by glioblastoma cells may act locally on tumor cells, possibly as a growth modulator.

Endothelin-1↗
PubMed2000

Characterization of human and rat glucagon-like peptide-1 receptors in the neurointermediate lobe: lack of coupling to either stimulation or inhibition of adenylyl cyclase.

Glucagon-like peptide-1 (GLP-1) has been shown to bind to the posterior pituitary in the rat. We examined GLP-1 binding sites in human postmortem and rat pituitaries. Dense [125I]GLP-1 binding was seen in both human and rat posterior pituitary. In rat neurointermediate lobe membranes the binding site showed a Kd of 0.2 +/- 0.01 nM and a binding capacity of 600 +/- 33 fmol/mg protein (n = 3). In human pituitary membranes the binding site showed a Kd of 0.82 +/-0.05 nM and a binding capacity of 680 +/- 93 fmol/mg protein (n = 3). Chemical cross-linking showed a relative mol wt for the receptor-ligand complex of 73,100 +/- 1,400 (n = 3) in man and 59,300 +/- 900 (n = 3) in rat. GLP-1 (1 microM) failed to increase cAMP levels measured in rat neurointermediate lobes, whereas pituitary adenylate cyclase-activating polypeptide (100 nM) increased cAMP from a basal level of 14 +/-1 to 80 +/- 4 pmol/neurointermediate lobe 15 min (n = 5; P < 0.01). GLP-1 (up to 1 microM) did not affect the pituitary adenylate cyclase-activating polypeptide-stimulated cAMP levels. GLP-1 (up to 1 microM) also did not stimulate release of vasopressin or oxytocin from isolated rat neurointermediate lobes. The posterior pituitary shows the highest density of GLP-1-binding sites yet seen, but their function and signal transduction mechanism remain unknown.

Adenylyl Cyclase Inhibitors↗
PubMed1999

Prediction of alpha-blocker response in men with benign prostatic hyperplasia by magnetic resonance imaging.

OBJECTIVES: To assess the value of magnetic resonance imaging (MRI) for predicting the alpha-blocker response in men with symptomatic benign prostatic hyperplasia (BPH) and to examine the relationship between MRI and the area density of smooth muscle cells in BPH. METHODS: Twenty-eight men were consecutively enrolled in this study and received tamsulosin 0.2 mg once daily for 4 to 6 weeks. The efficacy of tamsulosin was determined by measuring improvements in the maximum urinary flow rate (Qmax) and International Prostate Symptom Score (IPSS). The patients underwent T2-weighted MRI and were separated into a high (H) or iso-low (IL) group according to the signal intensity of the inner gland of the prostate compared with that of bone marrow of the proximal femur head. The area density of smooth muscle cells was determined using immunostaining with antiactin antibody in 16 prostate specimens. RESULTS: IPSS significantly decreased after the administration of tamsulosin from 16 +/- 1 to 8 +/- 1 (n = 28, P <0.0001 ), and 76.7% of the patients had an improved IPSS of 25% or greater. Qmax was significantly increased in group IL (P = 0.03) but not in group H. Of the patients in group IL, 53.3% had a Qmax response (an increase of Qmax of 30% or more); 15.4% did so in group H (P = 0.04). The area density of smooth muscle cells was 48.1 +/- 3.7% in group IL (n = 9) and 36.7 +/- 3.2% in group H (n = 7, P = 0.04). CONCLUSIONS: MRI is useful in estimating the area density of smooth muscle cells in the prostate and in predicting Qmax response for alpha-blocker therapy in patients with symptomatic BPH.

Adrenergic alpha-Antagonists↗