Biomedical subjects

H Sasano

Publications and source records attributed to H Sasano.

At least 181 records · Page 10Linked to original sources

PubMed1997

Aromatase in hyperplasia and carcinoma of the human prostate.

The expression and activity of aromatase was evaluated in 19 individuals with benign prostatic hyperplasia (BPH) and 26 prostatic carcinoma (PC) patients to elucidate the possible biological significance of in situ estrogen production in the development of human prostatic disorders. Marked aromatase immunoreactivity was observed in proliferative stromal cells, especially those around hyperplastic glands in 18 (95%) BPH patients and in stromal cells surrounding carcinomatous glands in 18 (69%) PC patient specimens. The percentage of aromatase-positive stromal cells did not differ between BPH and PC. No significant correlation was apparent between the percentage of aromatase-positive cells and either the extent of carcinoma differentiation or surgical stage in the PC patients. Quantitation of aromatase activity by the [3H] water assay yielded values of 27.23 +/- 6.87 and 26.52 +/- 9.12 fmol/hr/mg of protein for BPH (nine patients) and PC (nine patients), respectively. Reverse transcriptase and polymerase chain reaction analysis revealed that the mean aromatase mRNA content was 1.671 +/- 0.82 and 1.11 +/- 0.51 attomole/ng of total RNA (tRNA) for BPH (seven patients) and PC (four patients), respectively. There were no significant differences in aromatase activity or aromatase mRNA concentration between PC and BPH. The alternative use of multiple exons 1 of the aromatase gene was also examined. Predominant aromatase gene transcripts contained exon 1b in three of four of PC specimens and two of three BPH specimens examined, in contrast to the use of exon 1d previously described in normal prostate. Unlike breast and endometrium, therefore, aromatase expression in human prostate was not associated with malignancy. However, overexpression of aromatase, possibly attributable to abnormal gene regulation, may result in estrogen production in situ and play a role in the induction or development of human prostatic disorders.

Aged↗

PubMed1997

A novel arachidonate-preferring acyl-CoA synthetase is present in steroidogenic cells of the rat adrenal, ovary, and testis.

We report herein the cDNA cloning of a novel rat acyl-CoA synthetase (ACS) that preferentially uses arachidonate and eicosapentaenoate. This newly identified ACS (designated ACS4) contains 670 amino acids and is 68% identical to rat ACS3, a previously characterized ACS that is highly expressed in brain. ACS4 was overproduced in Escherichia coli and the resulting enzyme was purified to homogeneity. The purified enzyme utilizes arachidonate and eicosapentaenoate most preferentially among C8-C22 saturated fatty acids and C14-C22 unsaturated fatty acids. Kinetic analyses revealed that the enzyme has a high affinity for arachidonate and eicosapentaenoate and low affinity for palmitate. ACS4 transcripts are detectable in a wide range of tissues, with the highest level in adrenal gland. Immunoreactivity to ACS4 was detected in the zona fasciculata and reticularis of adrenal gland, in the corpus luteum and stromal luteinized cells in ovary, and in the Leydig cells of testis.

Adrenal Glands↗

PubMed1997

Ultrastructural and confocal laser scanning microscopic examination of TUNEL-positive cells.

TdT-mediated dUTP-biotin nick end labelling (TUNEL) has been widely used for detecting cells with DNA fragmentation or apoptotic cells. However, since the concept of apoptosis is based on cellular ultrastructure, it is important to identify the morphological features of TUNEL-positive cells. In this study, we performed TUNEL and electron microscopic observation on serial semithin and ultrathin sections of pancreas from bilaterally adrenalectomized rats with caerulein-induced pancreatitis. TUNEL-positive cells were identified with two different ultrastructural patterns. One was characteristic of apoptosis, with condensed nuclei, intact mitochondria, and zymogen granules. The other pattern was one of marked cellular degeneration, possibly representing the end stage of cell death. Cells which did not demonstrate these ultrastructural patterns were not labelled by the TUNEL method. The three-dimensional structure of TUNEL-positive cells was also investigated by confocal laser scanning microscopy (CLSM), which showed the apoptotic nuclei exhibited various three-dimensional structures. These results confirm the utility of the TUNEL method in detecting apoptosis; application of the technique reported in this study will contribute to the further characterization of individual TUNEL-positive cells.

Acute Disease↗

PubMed1997

Correlations between p21 expression and clinicopathological findings, p53 gene and protein alterations, and survival in patients with endometrial carcinoma.

The p21 protein inhibits cyclin-dependent kinases and mediates cell-cycle arrest and cell differentiation. It is induced by wild-type p53, but not by mutant p53. This study of 75 patients with endometrial carcinoma investigates the relationship between p21 expression and the functional status of p53, and the usefulness of p21 as a prognostic marker. Correlations were determined between p21 immunoreactivity, p53 overexpression as examined by immunohistochemistry, p53 DNA mutations as examined by polymerase chain reaction-single-stranded conformation polymorphism (PCR-SSCP) analysis, and clinicopathological features, including the clinical outcome. Immunoreactivity for p21 and p53 mutations were detected in 47 (62.7 per cent), 37 (49 per cent), and 23 (31 per cent) patients, respectively. There were no significant correlations between the presence or absence of p21 immunoreactivity and p53 overexpression and DNA mutations. Survival curves revealed that patients with p53 overexpression tended to have a poorer prognosis than those without p53 overexpression (P = 0.104), that patients with p53 mutations had a significantly worse prognosis than those without mutations (P = 0.035), and that patients with p21 expression tended to have a better prognosis than those without p21 expression (P = 0.074). Immunohistochemical analysis of p21 was not useful for evaluating the functional status of p53 in patients with endometrial carcinoma. Both p21 expression and p53 abnormalities were considered as prognostic indicators in patients with endometrioid endometrial carcinoma.

Biomarkers, Tumor↗

PubMed1997

Genotype analysis of prepro-vasopressin signal peptide in vasopressin-producing and -non-producing lung tumors.

A polymorphism in the nucleic acid sequence encoding the signal peptide of the human prepro-vasopressin (AVP) has been reported in an AVP producing small cell lung carcinoma (SCLC) cell line. The difference predicts expression in tumor cells of a variant signal peptide with Pro for Leu 11. To clarify whether this difference is required for AVP secretion from SCLC cells and/or reflects increased mutagenesis in malignant tumors, the exon encoding the signal peptide of prepro-AVP in two AVP producing SCLC and 9 non-producing lung tumors was amplified using polymerase chain reaction. The variant sequence was neither found by direct sequencing nor by restriction enzyme analysis. These results suggest that similar to the hypothalamus the normal signal peptide is functional in tumor cells and that the variant signal peptide is not a prerequisite for AVP secretion from SCLC cells.

Animals↗

PubMed1997

Expression of adrenomedullin mRNA in the human brain and pituitary.

We have recently reported the presence of immunoreactive (IR) adrenomedullin (ADM) in the human brain. In the present study, the expression of ADM mRNA was studied by Northern blot analysis in the human brain and pituitary, and the presence of IR-ADM in the human pituitary was studied by radioimmunoassay. ADM mRNA was clearly detected in every region of the brain examined and in the pituitary. High concentrations of IR-ADM were present in the whole pituitary (16.7 +/- 2.0 pmol/g wet weight, mean +/- SEM, n = 4). Reverse phase high performance liquid chromatography of the pituitary showed a peak eluting in the position of human ADM(1-52). These findings suggest that ADM acts as a neuromodulator or a neurotransmitter in the brain, and as an autocrine factor, a paracrine factor, or a neurohormone in the pituitary.

Adrenomedullin↗

PubMed1997

Specific adrenomedullin binding sites in the human brain.

Binding sites for adrenomedullin in human brain were investigated and characterized by radioligand binding. Specific binding sites for adrenomedullin were present in every region of human brain (cerebral cortex, cerebellum, thalamus, hypothalamus, pons and medulla oblongata) obtained at autopsy. Despite the homology with calcitonin gene-related peptide (CGRP), CGRP was a poor inhibitor of [125I]adrenomedullin binding (IC50 > 1 microM) compared with adrenomedullin(1-52) (IC50 = 1.2 +/- 0.5 nM, mean +/- SEM, n = 3). Three adrenomedullin fragments, adrenomedullin(1-12), adrenomedullin(22-52), and adrenomedullin(13-52), were also poor inhibitors of the binding (IC50 = 0.3 microM), suggesting that the whole molecule of adrenomedullin(1-52) is required for binding to the receptor. Scatchard plots of [125I]adrenomedullin binding in human brain (cerebral cortex) gave a dissociation constant of 0.17 +/- 0.03 nM and maximal binding of 99.3 +/- 1.9 fmol/mg protein (n = 5). These findings suggest that specific adrenomedullin binding sites that differ from the CGRP receptors exist in human brain. This indicates a possible novel neurotransmitter/neuromodulator role for adrenomedullin in human brain.

Adrenomedullin↗

PubMed1997

Analysis of the p53 gene mutations in patients with multiple primary cancers of the oesophagus.

We investigated genetic alterations of the p53 gene in two patients with multiple primary oesophageal squamous cell carcinomas (ESCs). We found that each primary tumour could be distinguished by mutation of p53. Moreover, mutations detected in the p53 gene in metastatic lymph nodes were the same as those detected in at least one of the primary tumours. Our results presented the possibility of: (1) discrimination of primary and metastatic legions in patients with multiple primary ESCs; (2) determination of metastatic pathway to regional lymph nodes; and (3) application for the development of a better clinical management of patients with multiple primary ESCs.

Aged↗

PubMed1997

Immunohistochemical studies on EGF family growth factors in normal and ulcerated human gastric mucosa.

Expression of members of the epidermal growth factor family, including epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha), amphiregulin (AR), and Cripto, as well as their putative receptor, epidermal growth factor receptor (EGFR), was studied immunohistochemically in human gastric mucosa to evaluate their possible roles in cell proliferation of normal and regenerative gastric mucosa. We also examined the correlation betwen cell proliferation and EGFR by double immunohistochemical staining for proliferating cell nuclear antigen (PCNA) and EGFR. In normal gastric mucosa, TGF-alpha, Cripto, and AR immunoreactivities were observed in the surface epithelial and parietal cells of gastric fundic glands, respectively. EGF immunoreactivity was not observed in any of normal mucosa examined. EGFR immunoreactivity was detected on foveolar cells in proliferative zones and in parietal cells. Double immunostaining revealed that EGFR immunoreactivity was distributed much more widely than PCNA immunoreactivity. PCNA positive epithelial cells adjacent to gastric ulcer margin expressed relatively intense EGFR but did not express any of the growth factors examined. On the other hand, relatively intense immunoreactivity of both TGF-alpha and Cripto was detected in PCNA-negative regenerative epithelium located distant from gastric ulcer margin. Relative immunoreactivity of AR in regenerative gastric epithelium associated with ulcer was not different from that in normal gastric mucosa. TGF-alpha, AR, and Cripto are considered to play important roles in normal gastric mucosal proliferation, and TGF-alpha and Cripto may be involved in ulcer healing, possibly via a paracrine mechanism.

Amphiregulin↗

PubMed1997

Double adenomas with different pathological and hormonal features in the left adrenal gland of a patient with Cushing's syndrome.

We report a 52-year-old women with Cushing's syndrome who presented with two adenomas in the left adrenal gland. One tumour appeared dark brown and the other appeared yellow on the cut surface. The non-neoplastic adrenal demonstrated marked cortical atrophy. Upon histological examination, the brown tumour was found to be composed of both compact and clear cells. In contrast, the yellow tumour was composed of clear cells associated with pseudoglandular formation and marked degeneration. Immunohistochemical studies demonstrated positive immunostaining of cytochrome P-450 specific for 17 alpha-hydroxylation (P-450c17) in the brown but not the yellow tumour. Other steroidogenic enzymes except for dehydroepiandrosterone sulphotransferase were detected in both tumours. The biochemical activities of 21-hydroxylase, 17-hydroxylase and 11 beta-hydroxylase in the brown tumour (6.10 nmol/mg protein/4 minutes, 1.87 nmol/mg protein/2 minutes and 5.71 mumol 11-OHCS formed/g protein/10 minutes, respectively) were much greater than those in the yellow tumour. Gel-supported three-dimensional native-state primary culture of the tumours demonstrated a much higher concentration of cortisol in the culture medium for the brown tumour (5750 nmol/l on 4th day). Vimentin expression was detected in both tumours but cytokeratin expression was detected only in the yellow tumour. The Ki67 labelling index in the brown tumour was greater than that in the yellow tumour. These results indicated that these two adenomas had different biological characteristics and the brown tumour was primarily involved in over-production of cortisol in this patient. When analysing unilateral multiple adrenocortical lesions, approaches using immunohistochemical studies for steroidogenic enzymes, enzyme activity assays and cell culture can help to define the steroidogenesis of individual adrenocortical lesions.

Adenoma↗

PubMed1997

Adrenal adenoma with bilateral adrenocortical nodular change in a patient with Cushing's syndrome.

We report a 57-year-old male patient with adrenocorticotrophin (ACTH)-independent Cushing's syndrome and long-standing hypertension. Both abdominal computed tomographic scan and magnetic resonance imaging revealed bilateral adrenal enlargement with the presence of a tumour in the left adrenal. Marked uptake of 131I-6 beta-iodomethyl-19-norcholesterol was observed only in the left adrenal gland. Left adrenalectomy and biopsy of the right adrenal gland were subsequently performed. Histological examination revealed the presence of an adrenocortical adenoma in the left adrenal with multiple adrenocortical nodules in both left and right non-neoplastic adrenals. Peri- and intraadrenal arteries and arterioles demonstrated marked arteriosclerotic vascular changes. Immunoreactivity for several steroidogenic enzymes was present in the tumour and markedly diminished in the non-neoplastic adrenals. This patient with Cushing's adenoma is considered to have developed adrenocortical nodules in the nonneoplastic adrenal possibly as a result of localized compensatory overgrowth of adrenocortical cells in response to ischaemic changes due to arteriopathy. When examining patients with Cushing's syndrome and bilateral adrenal enlargement, the possibility of concomitant adenoma and adrenocortical nodule formation should also be considered in the differential diagnosis

3-Hydroxysteroid Dehydrogenases↗

PubMed1997

Localization of steroidogenesis and steroid receptors in human corpus luteum. Classification of human corpus luteum (CL) into estrogen-producing degenerating CL, and nonsteroid-producing degenerating CL.

In the analysis of the regulation of human corpus luteum, it is very important to localize the sites of specific steroid hormone production to obtain a better understanding of luteal function. We have examined expression of steroidogenic enzymes, steroid receptors, and adrenal 4 binding protein (Ad4BP), a transcription factor of steroidogenesis, in corpus luteum of normal cycling human ovary. Corpus luteum can be classified into four different stages from ovulation to complete regression or fibrosis based on these findings: (1) corpus luteum, (2) steroid-producing degenerating corpus luteum or SPDCL, (3) nonsteroid producing or NSPDCL, and (4) corpus albicans. Corpus luteum in the luteal phase is characterized as follows: (a) the expression of P450scc (cholesterol side chain cleavage), 3 beta HSD (hydroxysteroid dehydrogenase), and Ad4BP in almost all the luteinized granulosa and theca cells, consistent with active progesterone biosynthesis; (b) expression of estrogen-producing P450arom (aromatase) in luteinized granulosa cells, indicating active estrogen production and that of P450c17 (17 alpha hydroxylase) in luteinized theca cells, and (c) expression of progesterone receptor (PR) and androgen receptor (AR) in both luteinized granulosa and theca cells. SPDCL correspond to corpus luteum undergoing regression or degeneration in the following cycle and are characterized as follows: (a) absence of all the steroidogenic enzymes and Ad4BP in the luteinized granulosa cells, suggestive of hormonally inactive nature of these cells and (b) marked expression of P450scc, 3 beta HSD, P450c17 and Ad4BP in luteinized theca cells. NSPDCL is characterized as the absence of all the steroidogenic enzymes and sporadic expression of Ad4BP in luteinized theca cells. These findings indicate that luteal cells remain even after losing expression of steroidogenic enzymes, consistent with a prolonged process of degeneration or regression of human corpus luteum. In corpus albicans, all the cells were replaced by fibrosis and steroidogenic enzymes; steroid receptors and Ad4BP were not expressed at all. Localization of steroidogenesis in human corpus luteum has thus provided new insights into understanding of its biological features.

Corpus Luteum↗

PubMed1997

Macrophages in normal cycling human ovaries; immunohistochemical localization and characterization.

We evaluated the immunolocalization and characterization of macrophages in 28 normal cycling human ovaries. Two primary antibodies were used to detect the macrophages: PGM1, a general marker for macrophages, and 25F9 which is specific for phagocytosing macrophages. Spindle-shaped cells positive for PGM1 but negative for 25F9 were observed in the stroma (123.6 +/- 1.05 cells/10(-6) m2) and theca layer of the follicle (mean ranged from 22.61 to 53.79) and the number of these cells did not change throughout the cycle. After ovulation, PGM1 positive cells with ballooning bodies began to appear in the early corpus luteum (111.8 +/- 0.83). The number of these macrophages increased in the mid and late corpora lutea, and reached maximum in the early degenerating corpus luteum (1231.0 +/- 3.29). A lower number of PGM1 positive ballooning macrophages were observed in the atretic follicle (177.9 +/- 1.42). 25F9 positive cells were also observed among the PGM1 positive balloon-shaped cells. The number of cells double positive for 25F9 and PGM1 was observed in the mid corpus luteum (44.6 +/- 0.46), increased in the late corpus luteum and early degenerating corpus luteum, and reached plateau in the late degenerating corpus luteum (549.0 +/- 5.82). A lower number of these double positive macrophages were also observed in the atretic follicle (64.8 +/- 0.36). The ratio of 25F9 to PGM1 positive cells increased in parallel with ageing of the corpus luteum (0.19 in the mid corpus luteum, 0.39 in the late corpus luteum, and 0.37 in the early degenerating corpus luteum), and the great majority of PGM1 positive cells were also immunopositive for 25F9 in the late degenerating corpus luteum (0.81). These results suggest that in normal cycling human ovaries, macrophages are mainly involved in luteal regression as scavengers.

Antibodies, Monoclonal↗

PubMed1997

Molecular cloning and characterization of rat ST1B1 and human ST1B2 cDNAs, encoding thyroid hormone sulfotransferases.

Human and rat cDNAs encoding thyroid hormone sulfotransferases have been isolated from their liver cDNA libraries. The isolated sulfotransferases, termed rat ST1B1 and human ST1B2, share 77 and 74% homologies at nucleotide and deduced amino acid levels. These forms showed less than 36 and 56% homologies to hydroxysteroid and aryl sulfotransferases, indicating that they constitute a new gene subfamily of aryl sulfotransferase. Expression of ST1B1 and ST1B2 in COS-1 cells resulted in the appearance of 33.0 and 32.5 kDa proteins, respectively, whose mobilities were identical with proteins detected in rat and human livers in Western blots using antibodies raised against ST1B1 and ST1B2 produced in Escherichia coli. The recombinant forms catalyzed sulfation of p-nitrophenol, 3,3',5-triiodothyronine (T3) and dopamine, but not of beta-estradiol and dehydroepiandrosterone. ST1B1 and ST1B2 showed higher affinities for formation of T3 sulfate (apparent Km 40.2 and 63.5 microM, respectively) than did thermostable phenol sulfotransferase ST1A3 (apparent Km 413 microM) or thermolabile phenol sulfotransferase ST1A5 (apparent Km 180 microM). These data indicate that the newly characterized sulfotransferases constitute a distinct ST1 subfamily of enzymes catalyzing the sulfation of T3 as a typical endogenous substrate in rats and humans.

Amino Acid Sequence↗

PubMed1997

Expression of epidermal growth factor-related proteins and epidermal growth factor receptor in common epithelial ovarian tumors.

The biologic significance of epidermal growth factor (EGF)-related proteins and EGF receptor (EGFR) in the development and progression of human ovarian carcinoma was studied in 7 ovarian cystadenomas, 6 mucinous tumors of low malignant potential (LMP), and 25 invasive adenocarcinomas by immunohistochemistry. Results were correlated with clinicopathologic features. We also examined immunoreactivity in five serous adenocarcinomas both before and after cisplatin chemotherapy. Amphiregulin (AR) expression was observed only in mucinous tumors (4 of 8 cystadenomas, 2 of 6 tumors of LMP, and 6 of 10 cystadenocarcinomas), but was not detected in the serous tumors or clear cell adenocarcinomas. EGF, cripto, and EGFR expression was significantly higher in mucinous cystadenocarcinomas than in mucinous cystadenomas or mucinous tumors of LMP. Three of five specimens obtained at a second operation after chemotherapy had more intense or diffuse immunostaining for transforming growth factor alpha (TGF-alpha) than the initial specimens did. Coexpression of more than two of the EGF-related proteins or EGFR significantly correlated with increased surgical stage in serous and clear cell carcinoma. AR expression seems to correlate with mucinous differentiation rather than with advanced stages of ovarian tumors. Our results indicate that expression of some EGF-related proteins is greater in certain subtypes of ovarian carcinomas than in their benign counterparts and that coexpression of these proteins is associated with advanced stage in serous and clear cell carcinoma. Increased TGF-alpha expression may also be related to ovarian tumor resistance to cisplatin chemotherapy.

Adenocarcinoma↗

PubMed1997

Ovarian endometrioid adenocarcinoma associated with steroidogenic foamy stromal cells.

A case of 69-year-old woman with endometrioid adenocarcinoma of the ovary with functioning stromal cells is presented. The patient complained of genital bleeding. Endometrial curettage revealed endometrial hyperplasia. Pre-operative levels of serum estradiol and progesterone were elevated, and serum gonadotropin levels were suppressed. The surgical specimen contained fist-sized, bilateral, solid, ovarian tumors and a mildly enlarged uterus. Histologically, the proliferating, atypical, columnar cancer cells resembled early secretory, endometrial epithelial cells with subnuclear vacuolation, and there were clusters of fat-laden foamy cells in the stroma. Immunohistochemically, the cancer cells were positive for cytokeratin and progesterone receptor but negative for estrogen receptor. The stromal foamy cells were immunoreactive for vimentin, progesterone receptor, P450 side chain-cleavage, 3 beta-hydroxysteroid dehydrogenase, and adrenal 4-binding protein. Immunoreactivities of P450c-17 alpha hydroxylase and aromatase were only focally observed. These findings indicated that the stromal cells were steroidogenic and mainly produced progesterone. The cancer cells that expressed progesterone receptors showed morphologic changes in response to hormonal stimulation.

3-Hydroxysteroid Dehydrogenases↗

PubMed1997

Low-grade adenosquamous carcinoma of the breast: a case report with cytologic findings and review of the literature.

The cytological and histopathological features of a case of low-grade adenosquamous carcinoma of the breast in a 47-year-old Japanese female was studied. The fine needle aspiration biopsy specimen of this case revealed proliferating ductal cells and atypical squamous cells in the same cell clusters. The resected left breast mass had a relatively well-circumscribed hard mass measuring 1.6 cm at its greatest dimension. Histologic examination demonstrated the co-existence of atypical squamous and ductal components in the same lesion, with transition between these two components. Desmoplastic stromal reaction was observed. The majority of ductal components had a two-layered composition, and sclerosing adenosis-like lesions were also observed at the periphery of the tumor. Based on these cytologic and histological findings, this tumor was diagnosed as low-grade adenosquamous carcinoma of the breast. This is the first report of the cytological findings of low-grade adenosquamous carcinoma of the breast, and it is important for pathologists to consider the possibility of low-grade adenosquamous carcinoma when the cytological findings described above are present in an aspiration cytology specimen of the breast.

Biopsy, Needle↗

PubMed1997

Juvenile granulosa cell tumor discovered during pregnancy: case report with immunohistochemical study of steroidogenesis.

A multilobular cystic juvenile granulosa cell tumor in a 33-year-old pregnant woman was examined. Pathological examination of the specimen at Cesarean section at 38 weeks of gestation revealed three different histological patterns; diffuse proliferation, trabecular or cord-like proliferation, and characteristic microfollicular patterns, as well as the presence of numerous luteinized stromal cells. These histological patterns were intermingled and transference among these patterns was detected. Immunoreactivity of steroidogenic enzymes including cholesterol side-chain cleavage, 3 beta-hydroxysteroid dehydrogenase and 17 alpha-hydroxylase was detected only in luteinized stromal cells. However, that of adrenal 4 binding protein, a transcription factor of steroidogenesis, was present in almost all the tumor cells as well as luteinized stromal cells, suggesting that tumor cells acquired the potential of metabolizing and synthesizing steroid hormones. The hormonal environment associated with pregnancy altered the histological and biological features of this juvenile granulosa cell factor.

Adult↗