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Biomedical subjects

R Yoshiyuki Osamura

Publications and source records attributed to R Yoshiyuki Osamura.

At least 19 recordsLinked to original sources
PubMed2006

Quantification of neutral cysteine protease bleomycin hydrolase and its localization in rat tissues.

A neutral cysteine protease, bleomycin hydrolase (BH), was found to be present in the range 3.7-131.1 ng per mg of rat tissues by enzyme-lined immunosorbent assay (ELISA). Newborn rat skin contained the highest amount of BH, and relatively high levels of BH were detected in the kidney and liver of 6-week-old male rats. The tissue distribution of BH in female rats was similar to that in male rats. Moreover, BH was detected in the extracts of erythrocytes and leukocyte-rich cells as well as in those of rat hemo-lymphocytic lineage cell lines by Western blotting. The BH level was increased at 6 weeks after birth and then slightly decreased. By immunohistochemistry, BH was localized as granular staining in the distal and proximal tubular cells of the kidney, and it was also detected in hepatocytes of the liver, in the red pulpy region of the spleen and in neurons of the brain. An immunoelectron microscopic study showed that BH-immunoreactivity was essentially located in the cytoplasm and at the outer membrane of the rough endoplasmic reticulum of epithelial cells of the kidney, as well as in that of hepatocytes of the liver. These results suggest that BH may play ubiquitous and unique roles in rat tissues.

Aging↗
PubMed2006

Phosphorylation of cAMP response element binding protein (CREB) as a marker of hypoxia in pituitary adenoma.

Hypoxia appears to be causatively related to pituitary adenoma. Currently, no biomarkers are available for the postoperative assessment of hypoxia in patient samples. Since the cAMP response element binding protein (CREB) is phosphorylated under hypoxic conditions, we examined whether CREB phosphorylation levels may be exploited as a novel biomarker for hypoxia in pituitary adenoma tissues. HP-75 human pituitary adenoma cells were incubated in 21% or 1% oxygen (normoxia and hypoxia, respectively), and Western blotting was employed to compare the levels of CREB and phosphorylated CREB (p-CREB). Our results show that p-CREB levels are significantly elevated under 1% oxygen, whereas the total CREB concentration remains unchanged. We further tested whether this phosphorylation is applicable as a marker of hypoxia in pituitary adenoma tissues removed by transsphenoidal surgery from 45 patients (32 females and 13 males, 22-78 years old). Fluorescence double immunohistochemistry data revealed that p-CREB in adenoma tissues is significantly elevated, and displays a positive correlation with Knosp grading (Spearman rank correlation; P = 0.0483, r = 0.3412), but no significant association with tumor subtype (Kruskal-Wallis analysis, CREB, P = 0.1072; p-CREB, P = 0.1888; phosphorylation ratio, P = 0.4916). Our findings collectively suggest that CREB phosphorylation may be employed as an in situ marker for hypoxia. Moreover, hypoxia and/or phosphorylation of CREB are associated with the cell invasiveness of pituitary adenomas.

Adenoma↗
PubMed2006

Ovarian nongestational choriocarcinoma mixed with various epithelial malignancies in association with endometriosis.

BACKGROUND: Ovarian choriocarcinoma (CC) is rarely encountered as compared to uterine CC. Furthermore, ovarian CC coexisting with surface epithelial tumor is very rare. CASE: A 50-year-old postmenopausal woman, gravida 0, was admitted to our hospital with abdominal pain and distention due to a complex ovarian tumor. The laboratory data showed high serum level of CA125, neuron specific enolase (NSE), and hCG beta-subunit C-terminal peptide (hCG-beta-CTP). Total abdominal hysterectomy, right salpingoophorectomy, and lymph node dissection were performed. The right ovary revealed a cystic tumor with two solid parts: larger part, endometrioid adenocarcinoma and small cell carcinoma; smaller part, predominantly CC and focally clear cell adenocarcinoma. CA125 was rapidly decreased after first operation, but hCG-beta-CTP levels repeated distinctive fluctuations and NSE abruptly increased during the last few months before death. The patient died 10 months after the first operation. CONCLUSION: Only four cases of ovarian nongestational CC coexisting with surface epithelial tumor have been reported. This is the first reported case of admixture of CC with three epithelial malignancies. We assume that endometrioid and clear cell adenocarcinomas arose at different sites as tumorigenic factors in association with endometriosis, and the former may have been dedifferentiated into small cell carcinoma and the latter to CC. Coexistence of CC with small cell carcinoma is considered to be responsible for relative chemoresistance leading to poor prognosis.

Adenocarcinoma, Clear Cell↗
PubMed2006

PTTG overexpression is correlated with angiogenesis in human pituitary adenomas.

Human pituitary tumor transforming gene (hPTTG1) was recently identified as a protooncogene, which is a regulator of the cell cycle, as a homolog of yeast securin and a transcriptional activator of several angiogenic factors. Here we examined the relationships of hPTTG1 expression with cell proliferation, expression of the angiogenic factor, VEGF (vascular endothelial growth factor), and numbers of the blood vessels in the normal and/or adenomatous pituitary. With the exception of TSHoma, the expression of hPTTG1 was significantly higher in pituitary adenomas than in the normal pituitary gland. The cell proliferation activity was higher in pituitary adenomas than in the normal pituitary. Pituitary cell proliferation was significantly correlated with the level of hPTTG1 expression in the normal pituitary tissue, but there was no such correlation in the adenomas. The significant correlation of hPTTG1 with the VEGF expression and the numbers of the blood vessels was elucidated in pituitary adenomas. It is particularly noteworthy that immunohistochemical double staining indicated co-localization of VEGF in many hPTTG1-positive tumor cells. In conclusion, higher levels of hPTTG1 expression contribute to the pathobiology of pituitary adenomas by promoting angiogenesis rather than by activating cell proliferation, whereas hPTTG1 expression is related to mitotic activity in the normal pituitary gland.

Adenoma↗
PubMed2005

Impaired regulation of gonadotropins leads to the atrophy of the female reproductive system in klotho-deficient mice.

klotho-Deficient mice exhibit a syndrome resembling human premature ageing, with multiple pathological phenotypes in tissues including reproductive organs. It was proposed that Klotho might possess the hormonal effects on many organs. In this study, the female reproductive system of klotho mice was examined to reveal the mechanism that brought the female sterility by histological and molecular approaches. We observed cessation of ovarian follicular maturation at the preantral stage and the presence of numerous atretic ovarian follicles and atrophic uteri. In situ hybridization analysis revealed that LH receptor and aromatase P450 were not expressed in the ovaries. These results suggest the impairment of gonadal development during the antral transition process. We next addressed the responsible organs for the failure of antral transition. Transplantation of klotho ovaries to wild-type mice resulted in the ability to bear offspring. Administration of FSH or GnRH induced advanced maturation of ovaries and uteri in klotho mice. These results indicate that the female reproductive organs in klotho mice are potentially functional and that klotho gene deficiency leads to the atrophy of reproductive organs via impairment of the hypothalamic-pituitary axis. Absence of the estrus cycle and constant low trends of both FSH and LH levels were found in female klotho mice. Immunohistochemical analysis revealed that the production of both FSH and LH were decreased in pituitary gland. Taken together, our findings suggest the involvement of klotho in the regulatory control of pituitary hormones.

Animals↗
PubMed2005

Establishment of stable GH3 cell line expressing enhanced yellow fluorescein protein-growth hormone fusion protein.

To investigate, in real time, the transport and secretion of pituitary hormone, we have developed an experimental pituitary cell line, GH3 cell, which has secretory granules of growth hormone (GH) linked to enhanced yellow fluorescein protein (EYFP). This stable GH3 cell secretes secretory granules of GH linked to EYFP on stimulation by Ca2+ influx or Ca2 release from storage. This GH3 cell will be useful for the real-time visualization of the intracellular transport and secretion of GH.

Animals↗
PubMed2005

Dietary soybean enhances Pit-1 dependent pituitary hormone production in iodine deficient rats.

Reports have shown that soybeans are goitrogenic. In the present study, we investigated the effects of a high soybean diet in rats that were fed normal or iodine-deficient chow on the regulation of anterior pituitary hormone production. Iodine deficiency alone resulted in thyroid hyperplasia, reduced serum thyroxine levels, and a tendency towards an increase in serum thyroid stimulating hormone (TSH). The combination of a high soybean and low iodine diet (ID + DS) acted synergistically to induce thyroid hypertrophy, reduce serum thyroxine and tri-iodothyronine, and markedly increase serum TSH. Immunohistochemical analysis revealed that rats fed the ID + DS diet exhibited a marked increase in their number of pituitary TSH, prolactin (PRL), and growth hormone (GH) producing cells. Pituitary transcription factor-1 (Pit-1) which is involved in the expression of the TSH, PRL, and GH genes was also increased in ID + DS fed rats. These results suggest that a diet high in soybean products modulates anterior pituitary hormone production by regulating Pit-1 induction, in iodine-deficient animals.

Animals↗
PubMed2005

Case of uterine cervical carcinosarcoma.

Carcinosarcoma (CS) is a rare neoplasm that is called a mixed epithelial and mesenchymal malignancy. CS of the uterine cervix is much less common than its counterparts in the uterine corpus. A 61-year-old, gravida 2, para 2 woman, who had undergone menopause 16 years prior to the presentation, was diagnosed with CS of the uterine cervix. A semiradical hysterectomy was carried out on the diagnosis of stage Ib1 cervical cancer. The patient underwent whole pelvic 45 Gy radiation as a postoperative additional treatment, but she died from multiple organ failure by metastasis 17 months after the operation. The tumor protruded from the cervix to the vagina and measured 4.5 x 3.0 cm. Histologically, the tumor was characterized as a squamous cell carcinoma and mesenchymal malignancy, represented by osteosarcomatous components. The stroma was largely composed of atypical spindle-shaped cells, which were immunohistochemically demonstrated to be of epithelial origin. Uterine cervical CS is one of the aggressive malignancies, and squamous cell carcinomas are common epithelial counterparts of cervical CS as well as adenocarcinomas.

Carcinosarcoma↗
PubMed2005

Three-dimensional imaging of the intracellular localization of growth hormone and prolactin and their mRNA using nanocrystal (Quantum dot) and confocal laser scanning microscopy techniques.

Semiconductor nanocrystals (Quantum dots, Qdots) have recently been used in biological research, because they do not fade on exposure to light, and they enable us to obtain multicolor imaging because of a narrow emission peak that can be excited via a single wavelength of light. There have been no reports of simultaneous localization of mRNA and protein using Qdots. We successfully applied these advantages of Qdot and confocal laser scanning microscopy (CLSM) to three-dimensional images of the intracellular localization of growth hormone and prolactin and to their mRNA. In situ hybridization and immunohistochemistry using Qdots combined with CLSM can optimally illustrate the relationship between protein and mRNA simultaneously in three dimensions. Such an approach enables us to visualize functional images of proteins in relation with mRNA synthesis and localization.

Animals↗
PubMed2005

Olfactory neuroblastoma causing ectopic ACTH syndrome.

A 39-year-old woman who presented with typical Cushingoid appearance (moon facies, central obesity, purpura) was admitted to our hospital because of pulmonary infection. She was found to have hypertension, severe hypokalemia, and metabolic alkalosis. Endocrine data revealed elevated plasma levels of ACTH and cortisol with lack of circadian rhythm, non-suppressibility to high-dose dexamethasone, and hyperresponsiveness to CRH stimulation. Although no pituitary mass was detected by MRI of the brain, inferior petrosal sinus sampling showed a step-up of central to peripheral ACTH levels; these data are consistent with the diagnosis of Cushing's disease. She was successfully treated with metyrapone to control hypercortisolemia. Ten months later, a mass was detected in the ethmoid sinus, which was surgically removed. After resection of the ethmoid sinus tumor, her Cushingoid features and hypercortisolemia disappeared, but recurred after enlargement of a second mass in the maxillary sinus. After resection of the maxillary sinus tumor, her hypercortisolemia subsided. Histologically, the tumor tissues from both the ethmoid and maxillary sinus were identical and consistent with the diagnosis of olfactory neuroblastoma. Immunohistochemically, the immunoreactivities of ACTH and POMC were positive in the cytoplasm of tumor cells, and immunoreactive ACTH was demonstrated in both tumor tissues. Thus, this is the second rare case with ectopic ACTH syndrome caused by olfactory neuroblastoma thus far reported.

ACTH Syndrome, Ectopic↗
PubMed2005

Malignant gastric carcinoid causing ectopic ACTH syndrome: discrepancy of plasma ACTH levels measured by different immunoradiometric assays.

Discrepancy of plasma ACTH levels measured by different immunoradiometric assays (IRMA) in a case with malignant gastric carcinoid causing ectopic ACTH syndrome was examined by gel chromatography and immunohistochemical analysis. A 49-year-old male was found to have a large gastric tumor, with muscle wasting, hypertension, diabetes and hypokalemia caused by hypercortisolemia. His plasma ACTH levels, although initially elevated, were found to be almost in normal ranges. The discrepancy of plasma ACTH levels was proven to be due to different IRMA kits used; the initial assay was performed by a kit that could recognize high-molecular weight (HMW) form as well as ACTH(1-39), but the later assay by another kit that could recognize only ACTH(1-39). Pathological examination of the gastric tumor was consistent with the diagnosis of malignant carcinoid. Immunohistochemical study revealed that immunoreactivity of proopiomelanocortin (POMC) was positive within the tumor cells, whereas those of ACTH and prohormone convertase 1/3 were negative. Molecular sieving analysis of patient's plasma by gel chromatography coupled with ACTH radioimmunoassay which could recognize HMW form and ACTH(1-39) and two different IRMAs revealed that the predominant form of ACTH was HMW form with a minor peak of ACTH(1-39). This is a rare case of ectopic ACTH syndrome caused by malignant gastric carcinoid with preferential production of HMW form of ACTH, possibly due to unprocessed POMC.

ACTH Syndrome, Ectopic↗
PubMed2005

Association of neuroendocrine differentiation with neoadjuvant hormone therapy effects in prostatic cancer.

Histological therapeutic effects of neoadjuvant hormone therapy (NHT) in prostatic cancer were examined, focusing on the association with neuroendocrine differentiation (NED), using 69 radical prostatectomy cases. The effects of NHT were classified into 3 grades based on the extent of tumor degeneration as observed with hematoxylin and eosin staining. NED cells in the cancer were semi-quantified into 4 grades (negative, 1+, 2+, and 3+) by immunohistochemical staining of chromogranin A (CgA). According to the therapeutic effects, the cases are divided as follows: good response in 26 patients, intermediate in 20, poor in 23. The histological therapeutic effects were significantly weaker in the CgA-positive group than the CgA-negative group (p=0.02). A close relationship between the extent of CgA expression and the histological response was also demonstrated (p=0.007). In the biopsy specimens before NHT, CgA was positive in 46% (32/69) and there was no significant difference in histological therapeutic effects between the positive and negative groups. However, the therapeutic effects were significantly weaker in 22 CgA-positive cases for both biopsy and prostatectomy specimens than in 18 CgA-negative cases for both specimens (p=0.001). In conclusion, although it seems difficult to predict the therapeutic effects of NHT using the biopsy specimens of prostatic cancer, we believe that NED is negatively associated with histological response of prostatic cancer to NHT.

Adenocarcinoma↗
PubMed2005

Estrogen receptor-negative and human epidermal growth factor receptor 2-negative breast cancer tissue have the highest Ki-67 labeling index and EGFR expression: gene amplification does not contribute to EGFR expression.

Estrogen receptor (ER) and human epidermal growth factor 2 (HER2) are well-investigated molecules and the focus of many breast cancer therapies. There is a group of breast cancers lacking ER and HER2, but it is not fully understood. Treatment for these patients is limited to cytotoxic chemotherapy. The purpose of present study is to examine ER(-)/HER2(-) breast cancers, with a particular focus on epidermal growth factor receptor (EGFR). EGFR is a target molecule for which novel medicines have been recently developed for other organ cancers, however biological significance in breast cancer is not yet well demonstrated. Breast cancer specimens (n=58) were categorized into four groups: i) ER(+)/HER2(-) (51.7%); ii) ER(+)/HER2(+) (8.6%); iii) ER(-)/HER2(+) (20.7%); and iv) ER(-)/HER2(-) (19.0%). They were immunohistochemically (IHC) examined using antibodies for EGFR, platelet derived growth factor receptor (PDGFR)alpha, PDGFRbeta, parathyroid hormone (PTH) receptor, Ki-67, cyclinD1, p53, and vimentin. The Ki-67 labeling index (LI) was highest in ER(-)/HER2(-) (36.5%), and decreased in order from ER(-)/HER2(+) (31.4%), ER(+)/HER2(+) (17.7%), to (ER(+)/HER2(-) (15.9%) (p=0.001). EGFR, p53 and vimentin were highly expressed in ER(-)/HER2(-) breast cancer cells (p<0.01). CyclinD1 was inversely expressed to Ki-67 LI (p<0.001). Gene amplification of EGFR was examined by two in situ hybridization techniques, fluorescence in situ hybridization (FISH) and chromogenic in situ hybridization (CISH) in serial sections to IHC. Only 1 of 14 EGFR-positive breast cancers showed gene amplification at low levels by CISH. Overall, the ER(-)/HER2(-) breast cancer showed the highest Ki-67 LI, the most frequent expression of EGFR, p53 and vimentin, as well as the lowest expression of cyclinD1. It is unlikely that gene amplification contributes to EGFR expression. ER(-)/HER2(-) breast cancers have potential in the development of novel therapeutics, including targeted medicines.

Biomarkers, Tumor↗
PubMed2005

Screening program of prostate cancer at Tokai University Hospital: characterization of prostate-specific antigen measurement.

A total of 67,214 men participated in screening for prostate cancer (PC) using serum prostate-specific antigen (PSA) from April 1996 to March 2003 at Tokai University Hospital. In 3.5% (2330 / 67,214) of the men, an elevated PSA level (> 4.0 ng/ml) was found and 68.1% (1586/2330) of these subjects were examined at our Urological Outpatient Clinic. Re-testing of PSA showed that 8.4% (133/1586) had a normal level. Needle biopsy of the prostate was performed in 45.2% (633/1453) of the remaining men. As a result, 142 PCs were found and the detection rate was 0.2% (142 / 67,214). The age of the patients with PC was over 50 years. During this period, 135 individuals with voiding dysfunction were also diagnosed as having PC. Comparison of the patients detected by screening with those found at the outpatient clinic revealed significant differences of the age (64.8 vs. 71.9 years, p < 0.0001), serum PSA level (14.6 vs. 154.9 ng/ml, p < 0.0001), and clinical stage (p < 0.0001). In conclusion, a health screening program that includes serum PSA testing is useful for detection of PC at an earlier stage and in younger individuals. We recommend that all men aged 50 years or older undergo testing for PSA to detect PC at an early stage.

Aged↗
PubMed2004

Cocaine- and amphetamine-regulated transcript peptide in the rat anterior pituitary gland is localized in gonadotrophs and suppresses prolactin secretion.

Cocaine- and amphetamine-regulated transcript (CART) mRNA and CART peptide are abundant in the hypothalamic nuclei that control anterior pituitary function. CART peptide has also been localized in the anterior pituitary gland itself, although its role in pituitary function has not as yet been elucidated. In the present study, we investigated the localization and function of CART peptide in the anterior pituitary gland. Immunohistochemical observations revealed that CART peptide colocalized with FSH and LH in gonadotroph cells but that it was absent from the other hormone-producing cells. Immunoelectronmicroscopy suggested that CART peptide and gonadotropin were colocalized in the same secretory granules. CART peptide suppressed prolactin release from dispersed anterior pituitary cells 15 min after its addition into the media [basal production, 234.9 +/- 14.6 ng/ml vs. CART 55-102 peptide 100 nm, 125.0 +/- 18.2 ng/ml (P < 0.01, n = 5)]. Prolactin release was suppressed by CART in a dose-related manner; on the other hand, CART peptide did not affect the secretion of other anterior pituitary hormones. CART peptide synthesis by these cells was elevated 15 min after the addition of leptin to the media (100 nm), as determined by immunoblotting, but LHRH (10 nm) did not significantly affect CART peptide expression. These findings suggest that CART synthesis in the anterior pituitary may be stimulated by leptin and that CART peptide may play a role in the regulation of anterior pituitary hormone secretion in the rat.

Animals↗
PubMed2004

Utility of immunohistochemistry in breast cancer practice.

Immunohistochemistry (IHC) has been used to search for specific protein-products, to observe the unique characteristics of breast cancer, to differentiate breast cancer from cancers of other sites origin, to obtain information regarding genetic alterations, to investigate prognostic factors, and to provide predictive factors for efficient treatments. Technical developments make it possible to utilize IHC as a convenient diagnostic tool, and to use it in advanced protocols in combination with other histochemical techniques as well. In this review article, the development of IHC, IHC for differential diagnosis and IHC for providing information about hormone receptors and HER2 in breast cancer practice will be introduced. Standardization and quality control are critical issues to utilize IHC adequately in breast cancer practice.

Breast Neoplasms↗
PubMed2004

Quercetin-induced melanogenesis in a reconstituted three-dimensional human epidermal model.

Quercetin (3,5,7,3',4'-pentahydroxyflavone) is one of the most abundant natural flavonoids. It is present in various common vegetables and fruits. In this report, we examined the effect of quercetin on melanogenesis using a three-dimensional reconstituted human epidermal culture model, MelanoDerm, which is a new commercially-available cultured human epidermis containing functional melanocytes. Treatment with 10 microM quercetin induced an increase of tyrosinase activity in cultured epidermis after 3-5 days in time-dependent manner. In the quercetin-treated epidermis, furthermore, melanin content and tyrosinase expression were markedly increased, as shown by immunohistochemistry after a 7-day culture period. Ultrastructural studies clearly indicated an accumulation of mature melanosomes (stages III and IV) inside the basal layer of the cultured epidermis after the quercetin treatment. In addition, the dendrites of melanocytes extended further towards the adjacent keratinocytes after quercetin treatment. These results suggest that quercetin has an effect on maturation of melanosomes and that quercetin has the potential to induced melanogenesis in human epidermis.

Culture Techniques↗