Biomedical subjects

K Miyazaki

Publications and source records attributed to K Miyazaki.

At least 145 records · Page 8Linked to original sources

PubMed2000

Methacarn fixation: a novel tool for analysis of gene expressions in paraffin-embedded tissue specimens.

To establish a quantitative method for analysis of gene expressions in small areas of tissue after paraffin embedding, preliminary validation experiments with RT-PCR and Western blotting were performed using methacarn-fixed rodent tissues and a cultured PC12 cell line. A total RNA yield of 52 +/- 15 ng/mm2, sufficient for a quantitative RT-PCR of many genes, could be extracted from a deparaffinized 10-microm-thick rat-liver section by a simple, single-step extraction method. The low concentration of contaminating genomic DNA and the resolution of ribosomal RNAs in RNA gel proved the purity and integrity of the extracted RNA samples, allowing PCR amplification of a long mRNA sequence and mRNA species expressing low copy numbers. PCR amplification of mRNA-derived target gene fragments could be achieved by optimizing the amount of total RNA for reverse transcription and the number of subsequent PCR cycles for each gene. By this validation, organ- and sex-specific mRNA expression could be detected in methacarn-fixed paraffin-embedded tissues without additional DNase treatment of RNA samples. RT-PCR analysis could also be performed with total RNA extracted from deparaffinized tissue dissected with a laser capture microdissection system. In addition, extraction of protein yielded 4.9 +/- 2.1 microg/mm2 from a 10-microm-thick rat-liver section, allowing a quantitative expression analysis of protein by Western blotting. Thus, in addition to its advantages for immunohistochemistry, methacarn-fixed paraffin-embedded tissue has benefits for analysis of both RNAs and proteins in the cells of histologically defined areas.

Acetic Acid↗

PubMed2000

Cytokeratin profile relates to histological subtypes and intrahepatic location of intrahepatic cholangiocarcinoma and primary sites of metastatic adenocarcinoma of liver.

AIMS: We evaluated the cytokeratin profile of intrahepatic cholangiocarcinoma with respect to its histological classification and intrahepatic location (peripheral vs. hilar), and compared its profile with that of a variety of metastatic adenocarcinomas in liver. METHODS AND RESULTS: Expression of cytokeratins 7, 8, 18, 19 and 20 was immunohistochemically examined in intrahepatic cholangiocarcinoma (n = 77) and metastatic adenocarcinoma in liver (21 colorectal, 14 gastric, three gallbladder and three pancreatic cancers). Materials were autopsy or surgical specimens. Cytokeratins 7, 8, 18 and 19 were expressed in 75 (97%), 75 (97%), 59 (77%) and 71 (92%) cases of intrahepatic cholangiocarcinoma, respectively. Moderate and extensive expression of cytokeratin 18 was more frequent in the peripheral than in the hilar type. Moderate and extensive expression of cytokeratin 19 was seen in almost all cases of well-differentiated intrahepatic cholangiocarcinomas, while expression was decreased relatively in the moderately and decreased more in the poorly differentiated cases. While cytokeratin 20 was not found in non-neoplastic biliary epithelia or in well-differentiated intrahepatic cholangiocarcinomas, this cytokeratin was occasionally detectable in moderately and poorly differentiated intrahepatic cholangiocarcinomas and its expression was more frequent in the hilar type. Cytokeratin 20 expression was observed in 17 (81%) of metastatic adenocarcinomas in liver from colorectal regions, to a lesser degree in those from gastric regions, and was rare in those from gallbladder and pancreatic regions; cytokeratin 7 showed a reverse expression pattern in these metastatic adenocarcinomas in liver. The profile of cytokeratins 7 and 20 of metastatic colorectal and gastric carcinomas differed from that for intrahepatic cholangiocarcinomas, while that of metastatic gallbladder and pancreatic carcinoma was similar to that for intrahepatic cholangiocarcinomas. Moreover, cytokeratin 18 and 19 expression was significantly infrequent in metastatic gastric carcinomas than in intrahepatic cholangiocarcinomas and metastatic colorectal carcinomas. CONCLUSION: The combined immunostaining of cytokeratins 7, 18, 19 and 20 is useful for the characterization of intrahepatic cholangiocarcinomas with respect to histological subtypes and intrahepatic location. It helps to differentiate intrahepatic cholangiocarcinoma from metastatic adenocarcinomas in liver and from colorectal and gastric regions; it also indicates the primary focus metastatic adenocarcinomas in livers.

Adenocarcinoma↗

PubMed2000

Abnormal distribution of collagen type IV in extrahepatic bile duct carcinoma.

The present study investigated the pathogenesis of desmoplastic stroma formation, which is characteristic of most bile duct carcinomas and other scirrhous carcinomas. Using immunohistochemical analysis, the expression of collagen types I and IV, laminin and TGF-beta1 was examined in human extrahepatic bile duct carcinoma and compared with gastric and colon carcinoma. In addition to delineating the basement membranes of carcinoma nests and blood vessels, collagen type IV was present along the thick bundles of collagenous fibers in the stroma of extrahepatic bile duct carcinoma and scirrhous gastric carcinoma. The immunoreactivity of collagen type IV was strong in the adjacent or surrounding interstitium of tumor cell nests, but was absent or weak in older, more central portions of the tumor that contained sclerotic collagen. In situ hybridization demonstrated active expression of collagen alpha1(IV) mRNA in extrahepatic bile duct carcinoma and scirrhous gastric carcinoma cells. These results suggest that, although collagen type IV is typically a component of the basement membrane, it is expressed in the interstitial stroma of extrahepatic bile duct carcinoma and scirrhous gastric carcinoma where it may play a role in desmoplastic stroma formation.

Adenocarcinoma↗

PubMed2000

Up-regulation of fas ligand at early stages and down-regulation of Fas at progressed stages of intrahepatic cholangiocarcinoma reflect evasion from immune surveillance.

We examined immunohistochemically the possible participation of the Fas/Fas ligand (FasL) system in intrahepatic cholangiocarcinoma (ICC) during the escape from immune surveillance, using 68 cases of ICC, 29 cases of normal intrahepatic large bile ducts, and 18 cases of biliary dysplasia. Apoptosis of tumor-infiltrating lymphocytes (TIL) was examined by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL). Fas was weakly expressed in normal intrahepatic bile ducts. Almost all biliary dysplasia and well-differentiated ICCs showed moderate to marked expression of Fas, while Fas expression was variable in moderately and poorly differentiated ICCs. Down-regulation of Fas expression was significantly correlated with histologic de-differentiation, vascular invasion, the size of ICCs, and short survival of ICC patients. By in situ hybridization, FasL mRNA were frequently and strongly expressed in biliary dysplasia compared with non-neoplastic intrahepatic bile duct. In well-differentiated ICCs, FasL mRNA expression was frequent and intense. But, the expression gradually decreased in moderately and poorly differentiated ICCs. Down-regulation of FasL mRNA expression in ICCs was correlated with perineural invasion and tumor size (over 4 cm) (P <.05). Apoptotic TIL were more frequent in ICC foci than in non-neoplastic foci remote from ICC foci. These findings suggest that a tumor evasion mechanism involving Fas/FasL exists in ICC; frequent and intense expression of FasL mRNA in well-differentiated ICCs enable them to escape immune surveillance by counterattacking Fas-bearing TIL. This counterattack becomes insensitive in poorly differentiated ICCs, in which the down-regulation of Fas gives them a resistance against the FasL-expressing TIL. These mechanisms may be involved in the tumor progression.

Adult↗

PubMed2000

Detection of thioredoxin in gastric cancer: association with histological type.

Thioredoxin (TRX) is a redox-active protein with multiple intra- and extracellular functions. This protein exists ubiquitously in all life forms, from primitive living cells, such as Escherichia coli and yeast, to higher mammals. Recently, augmentation of the expression and transcription level of TRX has been reported in tumors of various organs. In this study, we examined the expression of TRX in gastric cancer with respect to its histological type and depth of invasion. The association with cell proliferation was also studied. Results of histochemical analysis of surgical specimens as well as cytochemical analysis and Northern blot analysis of gastric cancer cell lines indicated that TRX is predominantly expressed in undifferentiated type gastric cancer rather than in the differentiated type. Neither the depth of tumor invasion nor cell proliferation significantly determined the staining intensity for TRX.

Adenocarcinoma↗

PubMed2000

Safety and efficacy of oestriol for symptoms of natural or surgically induced menopause.

To assess the safety and efficacy of oestriol in relieving post-menopausal symptoms 53 post-menopausal Japanese women with climacteric symptoms, 27 with natural menopause (group I) and 26 with surgically induced menopause (group II), received oral oestriol, 2 mg daily for 12 months. Clinical parameters including Kupperman index (KI) and the degree of satisfaction with symptomatic relief; serum concentrations of oestradiol, FSH and LH; serum lipids; blood pressure; bone mineral density, serum calcium (Ca), alkaline phosphatase (ALP), and urinary Ca were compared between the two groups. Oestriol improved KI in groups I and II by 49 and 80% respectively. Satisfaction with treatment was 85% in group I and 93% in group II. For both parameters, values were significantly different between groups I and II (P < 0.05 for both). Serum concentrations of oestradiol, FSH and LH changed in group I versus group II 6 months after initiation. A significant decrease in serum ALP and Ca/Cr was observed in group I at 6 months. Except for serum triglycerides, oestriol had no significant effect on lipids. Systolic and diastolic blood pressures were significantly decreased in group I at 3 months versus baseline. Slight vaginal bleeding occurred in 14.3% of group I. Histological evaluation of the endometrium in all women of group I and ultrasound assessment of the breasts following 12 months of oestriol treatment found normal results in all women. Therefore, oestriol appeared to be safe and effective in relieving symptoms of menopausal women. The beneficial biochemical effects of oestriol were marked in the natural menopause. Overall, oestriol may serve as a good choice for hormone replacement therapy to protect against other climacteric symptoms in post-menopausal women who do not need medication for osteoporosis or coronary artery disease.

Adult↗

PubMed2000

Expression of the adrenomedullin gene in epithelial ovarian cancer.

Adrenomedullin (AM) gene expression was analysed in 60 cases of epithelial ovarian cancer, (29 serous, 14 mucinous, 13 endometrioid, three clear cell, and one undifferentiated) using reverse transcription-polymerase chain reaction (RT-PCR); 10 of the cases were of low malignant potential; 25 were stage I; three were stage II; 27 were stage III; and five were stage IV. The level of AM gene expression was described in terms of the relative yield of the AM gene to the beta2-microglobulin gene. AM gene expression ranged from 0.04 to 1.57 (median 0.36). The association between histological grade and AM gene expression was significant (P: = 0.027), however, the association with other clinico-pathological features, i.e. patients' age at diagnosis, stage of disease, residual tumour mass after initial surgery, and histological subtype were not significant. Survival data were available for all patients and univariate Cox regression analysis showed that the AM gene expression was significantly associated with a poor prognosis (P: = 0.019). Immunohistochemical studies showed that AM was localized in the outer cell membrane or the cytoplasm of the carcinoma cells and in the endothelial cells of the tumour stroma. The AM gene expression level may play a key role in the biology of epithelial ovarian cancer and may define a more aggressive tumour phenotype.

Adrenomedullin↗

PubMed2000

Expression of TP and TIE2 genes in normal ovary with corpus luteum and in ovarian cancer: correlation with ultrasound-derived peak systolic velocity.

Transvaginal colour and pulsed Doppler ultrasonography analyses of blood flow velocity have indicated that intra-tumoral peak systolic velocity (PSV) is a good indicator of ovarian malignancy. Therefore, we examined whether there was an association between the expression of angiogenic genes, e.g. thymidine phosphorylase (TP) and TIE2 and the PSV of blood flow in normal and cancerous ovaries. Initially, 40 patients were examined by transvaginal ultrasonography and 23 ovaries were surgically removed; 14 were normal with corpora lutea (CL) and nine showed ovarian cancer. The ovarian tissue was dissected according to areas of high blood velocity and gene expression was examined using the reverse transcriptase-polymerase chain reaction (RT-PCR). No significant differences were found between PSV in the normal ovary with CL and ovarian cancer (P = 0.95). TP gene expression was significantly higher in ovarian cancer than in normal ovary with CL (P = 0.02), while TIE2 gene expression was not significantly different (P = 0.186). There was a significant correlation between TIE2 gene expression and PSV in the normal ovary with CL (r = 0.633, P = 0.015), while TP expression was significantly correlated with the PSV in ovarian cancer (r = 0.757, P = 0.018). These results indicate that there is a biological difference between physiological and pathological angiogenesis, TIE2 having a physiological role and TP being involved in pathological angiogenesis.

Adult↗

PubMed2000

Involvement of p38 mitogen-activated protein kinase activation in bromocriptine-induced apoptosis in rat pituitary GH3 cells.

Bromocriptine, a dopamine D(2) receptor agonist, is a therapeutic agent for patients with prolactinoma and hyperprolactinemia. In this study we demonstrated that bromocriptine induced activation of p38 mitogen-activated protein (MAP) kinase, with concomitant induction of apoptosis in rat pituitary adenoma cell line GH3 cells. Treatment of GH3 cells for 48 h with bromocriptine increased the p38 MAP kinase activity up to 3- to 5-fold and simultaneously increased the number of apoptotic cells. Inclusion in the medium of SB212090 or SB203580, specific p38 MAP kinase inhibitors, completely abolished the bromocriptine-induced activation of p38 MAP kinase and significantly reduced the number of apoptotic cells. The bromocriptine-induced p38 MAP kinase activation was not prevented by S(-)-eticropride hydrochloride, a specific D(2) receptor antagonist. Treatment with either epidermal growth factor (EGF) or thyrotropin-releasing hormone (TRH), which stimulates p44/42 MAP kinase, rescued cells from the bromocriptine-induced apoptosis, with concomitant inhibition of the bromocriptine-induced p38 MAP kinase activation. These results suggest that bromocriptine induces apoptosis in association with p38 MAP kinase activation, and that the p44/42 MAP kinase signaling through EGF and TRH receptors has an opposing effect on p38 MAP kinase activation as well as on apoptosis induced with bromocriptine in GH3 cells.

Animals↗

PubMed2000

Expression of cyclooxygenase 2 by prostaglandin E(2) in human endometrial adenocarcinoma cell line HEC-1B.

The regulation of expression of cyclooxygenase 2 (COX-2) was investigated by treatment with PGE(2) in human endometrial adenocarcinoma cell line HEC-1B. One microM PGE(2) could stimulate the expression of COX-2 approximately twofold in this cell line. The same concentration of PGE(2) also stimulated activation of mitogen-activated protein kinase (MAP kinase) and protein kinase B (PKB). PGE(2)-induced MAP kinase activation was sensitive to a MAP kinase kinase (MEK) inhibitor, PD098059, and a protein kinase A inhibitor, H-89. PD098059 and H-89 also partially inhibited the expression of COX-2 stimulated by PGE(2). PGE(2) could stimulate the activation of PKB, which was sensitive to phosphatidylinositol-3-OH kinase (PI3K) inhibitor, wortmannin. Whereas wortmannin alone partially inhibited the expression of COX-2, a combination of wortmannin and PD098059 totally inhibited PGE(2)-mediated COX-2 expression. These results suggest that MAP kinase and PI3K pathways are stimulated with PGE(2), and that both of these pathways are involved in the expression of COX-2. In addition, they also suggest that protein kinase A remains upstream of PGE(2)-induced activation of MAP kinase in HEC-1B cells.

Adenocarcinoma↗

PubMed2000

Thymidylate synthase expression in epithelial ovarian cancer: relationship with thymidine phosphorylase expression and prognosis.

OBJECTIVE: Thymidylate synthase (TS) and thymidine phosphorylase (TP) are important enzymes involved in the de novo DNA synthesis and the salvage pathways for pyrimidine, respectively. Our purpose was to determine whether the gene expression of TS together with TP correlate with prognosis in epithelial ovarian cancer. METHODS: TS gene expression was analyzed by reverse transcription-polymerase chain reaction in 20 samples from normal ovaries and 56 epithelial ovarian cancers previously studied regarding TP gene expression. TS and TP protein localization was examined by immunohistochemistry. RESULTS: TS gene expression was significantly higher in epithelial ovarian cancer than in normal ovaries (p = 0.001). In patients with epithelial ovarian cancer, TS gene expression did not correlate with patient age, clinical stage, histologic type, or histologic grade. High TS gene expression (> median) significantly correlated with a poorer survival (p = 0.02). No significant correlation between TS and TP gene expression and different immunoreactivity patterns were found. Combined analysis of TS and TP gene expression demonstrated that the relative risk of death for tumors with high TS and high TP expression was greater than that for either only high TS or high TP gene expression (p = 0.002). CONCLUSION: TS and TP combined may indicate a poor prognosis for patients with epithelial ovarian cancer.

Adult↗

PubMed2000

Reversible regulation of tissue factor-induced coagulation by glycosyl phosphatidylinositol-anchored tissue factor pathway inhibitor.

Endothelial and tumor cells synthesize tissue factor pathway inhibitor (TFPI-1), which regulates tissue factor (TF) function by TF. VIIa. Xa. TFPI-1 quaternary complex formation (where VIIa and Xa are coagulation factors) and by translocation of these complexes into glycosphingolipid-rich microdomains of the cell membrane. Recombinant TFPI-1 added exogenously to cells is targeted to a degradation pathway. This study analyzes whether quaternary complex formation with endogenous TFPI-1 results also in internalization and degradation. We demonstrate that endogenous TFPI-1 and recombinant TFPI-1 differ in their distribution on the cell surface. Recombinant TFPI-1 is found in phospholipid- and glycosphingolipid-rich membrane domains, whereas endogenous TFPI-1 preferentially localizes to glycosphingolipid-rich microdomains. On quaternary complex formation, endogenous TFPI-1 remains protease sensitive and accessible for antibodies on intact cells, demonstrating that it is not appreciably internalized. Rather, regulation of TF by TFPI-1 is restored within 12 hours, consistent with dissociation of quaternary complexes on the cell surface. Endogenous TFPI-1 can be released from the cell surface by phospholipase treatment, indicating that TFPI-1 either is a glycosyl phosphatidylinositol (GPI)-anchored protein or binds to a GPI-linked receptor. We demonstrate that expression of a recombinant GPI-anchored form of TFPI-1 targets TF. VIIa complexes to glycosphingolipid-rich membrane fractions. Thus, GPI anchoring of TFPI-1 is sufficient for regulation of TF. VIIa complex function by a pathway of reversible inhibition rather than internalization and degradation.

Animals↗

PubMed2000

A case of aortic dissection with transient ST-segment elevation due to functional left main coronary artery obstruction.

A 48-year-old man with a history of hypertension and diabetes mellitus was hospitalized with sudden onset of severe chest pain. He was in cardiogenic shock with a systolic pressure of 60 mm Hg. His electrocardiogram (ECG) showed ST-segment elevation in the precordial leads suggestive of acute anteroseptal myocardial infarction. The ST-segment returned to baseline after the systolic blood pressure rose to 100 mm Hg with the administration of sympathomimetic agents. Aortography and transesophageal echocardiography demonstrated type A aortic dissection and aortic regurgitation. Aortography and short-axis transesophageal echocardiography showed during diastole almost complete collapse of the true lumen of the ascending aorta caused by the intimal flap. The patient underwent surgical repair of the aortic dissection and implantation of Palmaz stents in the carotid arteries. Decreased blood pressure and the presence of aortic regurgitation accelerated the collapse of the true lumen during diastole in the ascending aorta, resulting in functional obstruction of the left main coronary artery, which may have been related to ST-segment changes in this case.

Aortic Dissection↗

PubMed2000

Complex systems in technology and policy: telemedicine and telecare in Japan.

We have examined aspects of the development of telemedicine and telecare in Japan. Despite Japan's reputation as an integrated and technocratic country, the diffusion of telemedicine has fallen below expectations, notwithstanding the urgent need to solve the problems of an ageing society. There has been a fragmentation of objectives and perspectives within the corporate (manufacturing) sector and within the policy sector of central and local government. There has also been a broader fragmentation between manufacturers, government and users (doctors and hospitals). As a result, the success or failure of individual projects appears to depend not on the quality of the technology, and often not on the evident importance of the social need, but on the overall coherence of a complex socio-technical system.

Financing, Government↗

PubMed2000

Sex determination based on fecal DNA analysis of the amelogenin gene in sika deer (Cervus nippon).

A sex determination method using DNA extracted from feces has been developed for sika deer (Cervus nippon). We determined a partial sequence of the amelogenin gene of sika deer, which exists on both X and Y chromosomes with a deletion region on the Y chromosome. Based on the sexually dimorphic sequences, we designed a pair of primers which could amplify DNA fragments the lengths of which are different between males and females. PCR products were detected in 34 out of 37 fecal samples collected from captured deer and the sexes estimated by the present method were perfectly matched with the actual sexes.

Amelogenin↗

PubMed2000

Intercept-PCR, an improvement for elevating performance to find a new member of a certain gene family.

We have established a method by which the performance of reverse transcriptase coupled polymerase chain reaction (RT-PCR) for seeking a new gene is improved. The actual procedure is quite easy: it is only to add several specific oligonucleotides into the reaction mixture of the usual RT-PCR. To verify the effectiveness of this method is also easy: it is only to detect the PCR products in the preliminary experiment. The finding in the present study provides valuable information for gene cloning tactics.

Base Sequence↗

PubMed2000

Pituitary response to luteinizing hormone-releasing hormone in women with variant luteinizing hormone.

OBJECTIVE: To assess the LH response of the pituitary gland to GnRH stimulation in healthy women with a mutant beta-subunit (Trp8 to Arg8 and Ile15 to Thr15). DESIGN: Clinical study. PATIENTS: We studied 40 healthy non-pregnant Japanese women of known zygosity for the LH beta-subunit gene (3 homozygotes for the mutant gene, 17 heterozygotes, and 20 homozygotes for the wild type). All women had normal ovulatory cycles. MEASUREMENTS: Serum LH status was determined by comparing LH immunoassays results using a monoclonal antibody recognizing only wild-type LH with those from a polyclonal antibody assay recognizing both variant and wild-type LH. The ratio of monoclonal to polyclonal immunoassay results determined the serum LH status. LH secretion in response to a GnRH stimulation test was measured. RESULTS: All women with the wild-type LH showed a normal response of LH to GnRH according to both assays. Over the time course of the response, the ratios in women with wild-type LH showed no remarkable changes. The response curves in women heterozygous for the mutant peaked 15-30min after GnRH injection; their response patterns included a statistically significant decrease in the rates of response at 15min after injection. CONCLUSIONS: There are the differences in circulatory kinetics between the two LH forms and in regulation of the two types of LHbeta genes. The maximal response of the variant LH to pituitary stimulation with GnRH appears to be greater than that of wild-type LH.

Adult↗

PubMed2000

Japanese sisters associated with pseudohomozygous familial hypercholesterolemia and sitosterolemia.

Pseudohomozygous familial hypercholesterolemia is a rare condition of unknown etiology. Sitosterolemia is a rare autosomal recessively inherited disorder that is characterized by premature coronary artery disease, cutaneous xanthomas, and increased plasma plant sterols and 5alpha-stanols. Only a few cases of both sitosterolemia and pseudohomozygous familial hypercholesterolemia have been reported. In this study, we report two sisters with both conditions. With a low-cholesterol diet (< 250 mg/day), serum cholesterol concentration decreased rapidly to an almost normal level and cutaneous xanthomas gradually regressed and finally disappeared; however, plant sterol levels did not change during the period. Plant sterols should be measured in patients considered to have pseudohomozygous familial hypercholesterolemia. The two conditions in this family may have been the results of a single gene mutation. The findings also indicate that low cholesterol diet therapy is effective for the treatment of hypercholesterolemia but not of sitosterolemia in this family.

Child↗