Search PubMed⌕ Search

Biomedical subjects

K Miyazaki

Publications and source records attributed to K Miyazaki.

At least 73 records · Page 4Linked to original sources
PubMed2001

Uterine adenomatoid tumors confirmed by immunohistochemical staining.

We present a 39-year-old nulliparous woman who consulted our clinic for an 8-year history of infertility with no notable symptoms. There apparent uterine leiomyomas were found incidentally on clinical examination and imaging. The surgically enucleated specimens were white in color with variable consistency poorly defined margins. The tissues stained positive for cytokeratin but were negative for CD34 antibodies, indicating a mesothelial origin. Staining for vimentin and HBME1 was also strongly positive, supporting a mesothelial origin of the tumors. The patient became pregnant 6 months after surgery. A healthy male infant was delivered at term. Immunohistochemical staining establish the diagnosis of benign adenomatoid tumors derived from mesothelial tissue.

Adenomatoid Tumor↗
PubMed2001

The role of E-cadherin in the differentiation of gallbladder cancer cells.

Cell adhesion molecules are essential for development and maintenance of epithelial architecture. To clarify the role of these molecules in the morphology of gallbladder cancers, four human gallbladder cancer cell lines (GB-d1, KMG-C, GBK-1, and G-415) were examined in vitro. They showed noticeably different morphologies in our standard gel cultures (SC). GB-dl and KMG-C formed cystic and spheroid structures, respectively, which seemed to represent well-differentiated and moderately differentiated cancers, respectively. GBK-1 and G-415 showed branching and "pseudoglandular" structures, respectively, both of which seemed to indicate original dedifferentiated cancers. In floating gel culture (FC), only GB-d1 showed a highly increased tendency toward cyst formation. Expression of E-cadherin and alpha-catenin in the gallbladder cancer cell lines was investigated by Western-blotting analysis. Expression was detected in GB-d1 and KMG-C, but not in GBK-1 and G-415 cells. Furthermore, E-cadherin expression in GB-dl was 1.82 times greater in FC than in SC, while E-cadherin expression levels of KMG-C did not change. Neither GB-d1 nor KMG-C showed any difference in a-catenin expression between SC and FC. Immunostaining of GB-d1 revealed that these proteins were localized to the cell membrane. In contrast, heterogeneous localization of these proteins was detected in the spheroid structures of KMG-C, in both SC and FC. Electronmicroscopic examination revealed that reestablishment of the junctional complex occurred only in GB-d1 cells cultured in FC. The formation of cystic structures in GB-d1 was completely inhibited by an antibody against human E-cadherin. Both expression of E-cadherin and its membranous localization are required for well-differentiated-type morphogenesis in gallbladder cancer cells.

Antibodies, Monoclonal↗
PubMed2001

Comparison of Bassini repair and mesh-plug repair for primary inguinal hernia: a retrospective study.

The purpose of this study was to compare the mesh-plug repair with the Bassini repair for the treatment of primary unilateral inguinal hernias. Patients with primary unilateral inguinal hernias who underwent a Bassini repair (n = 118) between January 1992 and May 1996 and a mesh-plug repair (n = 113) between July 1996 and April 1998 were retrospectively reviewed. We recorded information regarding the types of hernia according to Nyhus classification, operation time, complications, postoperative recovery, and recurrence after surgery. The two groups were comparable regarding age, sex, side of hernia, types of hernia, and the follow-up interval. The operation time was 55 +/- 20min for Bassini repair and 54 +/- 18min for mesh-plug repair. There was no incidence of mesh infection in the mesh-plug repair cases. The amount of diclofenac sodium (suppository) was 307 +/- 222mg in the Bassini repair group and 132 +/- 182mg in the mesh-plug repair group (P < 0.0001). The length of hospital stay was 8.2 +/- 2.0 days in the Bassini repair group and 4.3 +/- 2.7 days in the mesh-plug repair group (P < 0.01). Nine patients (7.6%) in the Bassini repair group had recurrence, compared with one patient (0.9%) in the mesh-plug repair group. The recurrence-free survival in the mesh-plug repair group was significantly longer than that in the Bassini repair group (P = 0.03). In conclusion, patients with primary unilateral inguinal hernias who undergo a mesh-plug repair recover more rapidly and have less recurrence in comparison with those who undergo a Bassini repair.

Aged↗
PubMed2001

Molecular cloning, tissue expression, and chromosomal assignment of a novel gene encoding a subunit of the human signal-recognition particle.

Human cancers derived from breast, esophageal, or ovarian tissues frequently show allelic losses on chromosome band 17q25. Moreover, a locus responsible for hereditary focal nonepidermolytic palmoplantar keratoderma, a condition associated with esophageal cancer (TOC; tylosis with oesophageal cancer), has been mapped to the same band. During efforts to sequence, by shotgun methods, a 1-Mb target region that we had defined as the DNA segment harboring the putative tumor suppressor gene(s) involved in these events, we identified a novel cDNA. The full-length cDNA is 2495bp long and is expressed predominantly in skeletal muscle, heart, kidney, and placenta. The predicted product, a 627-amino-acid protein, exhibited significant sequence homology to the canine 68-kd subunit of the signal recognition particle that has been implicated in the transport of secreted and membrane proteins to the endoplasmic reticulum for proper processing. We confirmed the location of this gene at chromosome 17q25.1 by radiation-hybrid mapping and by fluorescence in situ hybridization.

Amino Acid Sequence↗
PubMed2001

Expression and prognostic significance of O6-methylguanine-DNA methyltransferase in hepatocellular, gastric, and breast cancers.

BACKGROUND: O6-Methylguanine-DNA methyltransferase (MGMT) is an enzyme that repairs O6-methylguanine, a promutagenic DNA base damaged by endogenous and environmental alkylating agents. There are few reports that describe whether or not abnormal MGMT expression correlates with the prognosis in human solid cancers. METHODS: The expression of MGMT was immunohistochemically evaluated in 60, 62, 105, and 46 paraffin-embedded samples from patients with curatively resected hepatocellular, gastric, colorectal, and breast cancers, respectively. RESULTS: The expression of MGMT was a positive predictive factor for overall survival in hepatocellular (P = .005) and gastric cancers (P < .001) and for relapse-free survival in breast cancers (P < .001). MGMT-positive gastric tumors (n = 42) were correlated with the absence of serosal invasion (P = .045), lymph node metastasis (P = .006), intestinal type (P = .018), and low pathological tumor, node, metastasis stage (P < .001). All breast tumors that recurred locally after operation were MGMT negative (P = .004). The clinicopathologic characteristics of colorectal cancers with respect to MGMT expression did not significantly differ. CONCLUSIONS: The expression of MGMT is a predictive prognostic marker in patients with hepatocellular, gastric, and breast cancers. These findings may help to establish therapeutic strategies for patients with these types of solid cancer.

Aged↗
PubMed2001

Effect of primers containing N-methylolacrylamide or N-methylolmethacrylamide on dentin bond durability of a resin composite after 5 years.

OBJECTIVES: The effect of experimental dentin primers containing N-methylolacrylamide (MEAA) or N-methylolmethacrylamide (MEMA) on bond durability of a resin composite (Photo Clearfil A) with a bonding agent (Clearfil Photo Bond) to bovine dentin was investigated. METHODS: The etching agents were 10% maleic acid (10% MA), 10% phosphoric acid (10% PA) and 10% citric acid-3% ferric chloride (10-3 solution). Water solutions of 35% hydroxyethyl methacrylate (HEMA), 50% MEAA or 30% MEMA were used as dentin primers. The etched dentin was pre-treated with the dentin primers for 30s. The resin composite systems were applied in a Teflon tube positioned onto pre-treated dentin surfaces. After water immersion for 1 day and 5 years, the shear bond strengths were measured. The amounts of calcium dissolved with etching agents were measured using atomic absorption spectrometry. The thicknesses of hybrid layers at the dentin-resin interfaces treated with 6 mol/l HCl and 1% NaOCl were measured using scanning electron microscopy. RESULTS: The bond strengths of the specimens (Controls) without primers to dentin etched with 10% MA and 10-3 solution significantly decreased after immersion in water for 5 years (p<0.05) while other bond strengths did not decrease. The bond strengths of the composites to MEMA- and MEAA-primed dentin were significantly higher than that of the control after 1 day, regardless of the types of etching agents (p<0.05). The 5 year bond strengths of the composites to HEMA-, MEMA- and MEAA-primed dentin were significantly higher than that of the control, regardless of the types of etching agents (p<0.05). The 1 day and 5 year bond strengths of the composite to MEAA-primed dentin were significantly higher than those of the composites to HEMA-primed dentin, regardless of the types of etching agents (p<0.05). The highest amount (182.3+/-8.0 microg/cm(2)) of dissolved calcium was determined for the pre-treatment with 10% PA, followed by that (152.0+/-6.9 microg/cm(2)) with 10% MA and that (140.1+/-2.8 microg/cm(2)) with 10-3 solution (p<0.05). The hybrid layer thicknesses (approximately 1 microm) for 10-3 solution were thinner than those (approximately 2 microm) for others after HCl immersion. For the controls, the hybrid layers after NaOCl immersion become narrower or disappeared. The main fracture pattern of specimens was a mixture of resin-dentin interface failure and dentin cohesive fracture after the bond test. CONCLUSIONS: MEAA solution was more effective in improving the bond strength of the controls to etched dentin than was HEMA after 1 day and 5 years. Clearfil Photo Bond created good hybrid dentin layers which could resist NaOCl-attack and showed good dentin bond durability when dentin primers were used, regardless of the type of etching agent.

Acid Etching, Dental↗
PubMed2001

How enzymes adapt: lessons from directed evolution.

Enzymes that are adapted to widely different temperature niches are being used to investigate the molecular basis of protein stability and enzyme function. However, natural evolution is complex: random noise, historical accidents and ignorance of the selection pressures at work during adaptation all cloud comparative studies. Here, we review how adaptation in the laboratory by directed evolution can complement studies of natural enzymes in the effort to understand stability and function. Laboratory evolution experiments can attempt to mimic natural evolution and identify different adaptive mechanisms. However, laboratory evolution might make its biggest contribution in explorations of nonnatural functions, by allowing us to distinguish the properties nutured by evolution from those dictated by the laws of physical chemistry.

Algorithms↗
PubMed2001

Benign or malignant ovarian neoplasms and ovarian endometriomas.

STUDY OBJECTIVE: To investigate clinical features and biologic behavior of ovarian cancer that might be closely related to endometrioma and/or endometriosis. DESIGN: Retrospective study (Canadian Task Force classification II-2). SETTING: University hospital. PATIENTS: All 324 women who were operated for endometriomas and/or ovarian tumors 5 cm or greater in diameter between January 1988 and December 1997. INTERVENTION: One hundred twelve women underwent laparoscopic surgery and 212 had laparotomy. MEASUREMENTS AND MAIN RESULTS: All tissues were evaluated histologically. Clinical examinations including ultrasound and serum tumor makers were performed in all patients preoperatively. No malignancies were found at laparoscopic surgery (76 endometriomas, 36 ovarian tumors). The frequency of endometriosis in benign, borderline malignant, and malignant tumors was 9.7%, 12.5%, and 11.4%, respectively. Endometriosis was present most frequently (40%) in women with endometrioid adenocarcinoma. It was present in 81 patients with endometriomas and 25 with ovarian neoplasms. Of these, nine women (8.5%) had malignant tumors, including borderline malignancy. Among patients with malignant tumors, those without endometriosis were significantly older (mean +/- SD age 54.9 +/- 16.2 yrs) than those with endometriosis elsewhere in the pelvis (45.9 +/- 8.9 yrs). CONCLUSION: Endometriosis may be closely related to ovarian tumors such as endometrioid adenocarcinoma. Surgeons should be aware of this possibility, and candidates for laparoscopic surgery should be carefully selected based on preoperative evaluations.

CA-125 Antigen↗
PubMed2001

Expression of melanoma antigen-encoding gene-1 predicts lymph node involvement in early gastric carcinomas.

Our previous study suggested that melanoma antigen-encoding gene-1 may be activated in gastric carcinomas when the tumors develop or invade. In the present work we studied the gene as a preoperative indicator of lymph node involvement in early gastric carcinoma. We used a reverse transcription-polymerase chain reaction to analyze expression of the gene in 47 endoscopic biopsy specimens from early gastric carcinomas. Relationships between gene expression and histopathologic findings were analyzed statistically. Eight of 47 tumor samples (17.0%) expressed the gene. The gene was not expressed in adjacent nontumor samples from carcinoma patients or in tissues from patients with benign gastric diseases. Gene expression correlated with infiltrative tumor growth in contrast to tumors with expansive growth patterns (P = 0.018). Gene expression also correlated with expression of platelet-derived growth factor-A (P < 0.001). MAGE-1 gene expression in biopsy specimens was a preoperative indicator of nodal involvement (P = 0.013). In conclusion, melanoma antigen-encoding gene-1 expression in biopsy specimens from early gastric carcinoma may serve preoperatively as an indicator of lymph node involvement.

Aged↗
PubMed2001

Influence of midluteal serum prolactin on outcome of pregnancy after IVF-ET: a preliminary study.

PURPOSE: To investigate the relationship between serum prolactin levels in the midluteal phase and the prognosis of pregnancy after IVF-ET. METHODS DESIGN: Prospective study; SETTING: Shimane Medical University Hospital; PATIENTS: 29 patients completing their 34th IVF cycle; and MAIN OUTCOME MEASURES: Serum levels of prolactin, estradiol-17 beta, and progesterone in the midluteal phase. RESULTS: Midluteal prolactin levels were significantly lower in patients with early pregnancy loss than in the successful pregnancy group. The mean progesterone/prolactin ratio and the estradiol-17 beta/prolactin ratio were highest in patients with early pregnancy loss and were lowest in patients with successful pregnancies. CONCLUSIONS: Findings of this study suggest that measurement of the serum prolactin concentration in the midluteal phase is useful for predicting the outcome of IVF-ET.

Adult↗
PubMed2001

Expression of the hepatocyte growth factor/c-Met pathway is increased at the cancer front in breast carcinoma.

Expression of hepatocyte growth factor (HGF) and c-Met (HGF receptor) has been reported in many neoplasms. We investigated coexpression of HGF and c-Met to determine the role of the HGF/c-Met pathway in breast carcinoma, especially at the cancer front. Eighty-eight cases of carcinoma of the breast were studied by immunohistochemistry and by in situ hybridization for HGF and c-Met expression. The staining pattern was termed "front accentuation pattern" when it was most conspicuous at the cancer front. HGF and c-Met proteins were expressed in cancer and stromal cells, with autocrine and paracrine patterns. The front accentuation pattern of c-Met was observed in cancer cells, but not in stromal cells. The front accentuation pattern was not observed in HGF. Coexpression of HGF and c-Met at the cancer front was correlated with histologic grade, reduced patient survival and a high Ki-67 labeling index. Our findings suggest that the HGF/c-Met pathway acts primarily as a mitogen, especially at the cancer front, in a paracrine manner and affects some clinical factors, including patient survival.

Adult↗
PubMed2001

Composite glandular-endocrine cell carcinoma of the common bile duct.

A rare case of composite glandular-endocrine cell carcinoma of the common bile duct is presented. Histologically, this tumor consisted of adenocarcinoma and small-cell neuroendocrine carcinoma, with a transition between the two components. The two distinct areas of the tumor were immunohistochemically different, whereas the transitional zone exhibited characteristics of both areas. These features suggest that the tumor arose from a multipotential stem cell. Although it has been reported that the presence of neuroendocrine differentiation in carcinomas indicates a poor prognosis, the patient in the present case was well at the time of writing this report. This may be due to the fact that adenocarcinoma, which characteristically has a low proliferative activity, constituted the majority of the tumor.

Adenocarcinoma↗
PubMed2001

Expression of endogenous galectin-1 and galectin-3 in intrahepatic cholangiocarcinoma.

Galectins, a family of beta-galactoside-binding animal lectins, might be involved in tumor progression. In this study, the expression patterns of galectin-1 and -3 were examined immunohistochemically in intrahepatic cholangiocarcinoma (ICC), with emphasis on its development and progression as well as its histopathologic features, by use of samples of normal intrahepatic bile duct (n = 20), biliary epithelial dysplasia (n = 15), ICC (n = 40), and a cholangiocarcinoma cell line, CCKS1. In normal intrahepatic bile ducts, galectin-3 was constitutively but weakly expressed, whereas galectin-1 was not expressed. In hepatolithiasis, biliary epithelial dysplasia was strongly positive for galectin-3 but negative for galectin-1. Galectin-3 was frequently and strongly expressed in the cytoplasm of well-differentiated ICCs, and its expression was significantly decreased and less intense or even absent in poorly differentiated ICCs. Galectin-1 was expressed in carcinoma cells in ICC, and its incidence and extent were correlated with histologic dedifferentiation of ICC. Proliferative cell nuclear antigen (PCNA) labeling index (LI) was higher in ICC cases positive for galectin-1 than in those that were negative. Galectin-1 was strongly expressed in cancerous stroma of ICC, and this stromal expression was related to histologic dedifferentiation of ICC. In the carcinoma cell line CCKS1, galectin-1 and -3 were expressed in the cytoplasm of carcinoma cells, and galectin-1 was additionally detected in the culture medium. These results suggest that galectin-1 was newly expressed on carcinoma cells of ICC, and its overexpression seems to be associated with neoplastic progression and proliferative activities, and the expression of galectin-1 in cancerous stroma may also be related to the progression of ICC. Galectin-3 expression in epithelial cells is up-regulated in the preneoplastic and early neoplastic stages of ICC, although galectin-3 tends to disappear at later stages of ICC. HUM PATHOL 32:302-310.

Adult↗
PubMed2001

Critical role of type IV collagens in the growth of bile duct carcinoma. In vivo and in vitro studies.

Most extrahepatic bile duct carcinomas (EBDC) are characterized by a striking stromal response (desmoplasia). Our previous studies showed deposition of type IV collagen in the desmoplastic stroma beyond the basement membrane. Although type IV collagen is expressed in EBDC, little is known about the pattern of deposition in tumor stroma and how this matrix component influences the behavior of tumor cells. With the progression of desmoplasia in EBDC, different changes occurred in the quantity and localization of type IV collagen from that of type I collagen. Type I collagen was diffusely distributed in the stroma and appeared to be concentrated in the center of the tumors. In contrast, type IV collagen was deposited in the interstitium alongside carcinoma cells at the tumors' periphery. Weak or no type IV collagen deposition was detected in the more central portion of the tumors containing sclerotic collagens. To investigate the role of stromal type IV collagen in tumor cell proliferation, EBDC cell lines were cultured in a three-dimensional matrix containing varying compositions of type I collagen and type IV collagen. They were also assayed for cell adhesion and migration using in vitro models. Type IV collagen more extensively stimulated tumor cell proliferation, adhesion and migration in a dose-dependent manner than did type I collagen. All of these results suggest that modified tumor stroma with the presence of type IV collagen in EBDC provides a better environment for tumor growth and invasion.

Adenocarcinoma↗
PubMed2001

Value of magnetic resonance imaging in predicting efficacy of GnRH analogue treatment for uterine leiomyoma.

BACKGROUND: Estimating pharmacological efficacy is important when selecting conservative treatment of uterine leiomyoma. Hence, the ability of magnetic resonance (MR) imaging to predict gonadotrophin-releasing hormone (GnRH) analogue efficacy was investigated. METHODS: A total of 85 lesions was studied in 40 patients who were clinically diagnosed as having uterine leiomyoma and treated with GnRH analogue for 24 weeks. To evaluate changes in lesion size, T2-weighted and gadopentetate-dimeglumine (Gd-DTPA)-enhanced, T1-weighted MR images were obtained within 2 weeks before, and immediately after termination of, GnRH analogue treatment. RESULTS: An average 46.3% size reduction was observed in 45 lesions (52.9%); these were seen as low signal intensity on T2-weighted images and enhanced by Gd-DTPA. Also, an average 44.7% size reduction was observed in lesions enhanced by Gd-DTPA, irrespective of signal intensity findings on T2-weighted images. The average size reduction of unenhanced lesions was only 17.8%, and significantly different from enhanced lesions (P < 0.001). The prediction of efficacy was difficult in those lesions not enhanced. CONCLUSIONS: It is considered that evaluation of MR signal intensities, and the presence or absence of Gd-DTPA enhancement, would predict treatment efficacy before GnRH analogue administration.

Adult↗
PubMed2001

Caspase-independent cell death and mitochondrial disruptions observed in the Apaf1-deficient cells.

Apaf1 is a critical molecule in the mitochondria-dependent apoptotic pathway. Here we show that Apaf1-deficient embryonic fibroblasts died at a later phase of apoptotic induction, although these cells were resistant to various apoptotic stimulants at an early phase. Neither caspase 3 activation nor nuclear condensation was observed during this cell death of Apaf1-deficient cells. Electron microscopic examination revealed that death in response to apoptotic stimulation resembled necrosis in that nuclei were round and swollen with low electron density. Necrosis-like cell death was also observed in wild-type cells treated with z-VAD-fmk. Mitochondria were not only morphologically abnormal but functionally affected, since mitochondrial transmembrane potential (DeltaPsim) was lost even in cells with intact plasma membrane integrity. These mitochondrial alterations were also observed in the wild-type cells dying of apoptosis. Combined, these data suggest that cells without caspase activation, such as Apaf1-deficient cells or cells treated with caspase inhibitors, die of necrosis-like cell death with mitochondrial damage in response to "apoptotic stimulation."

Amino Acid Chloromethyl Ketones↗
PubMed2001

Effective fluconazole therapy for liver transplant recipients during continuous hemodiafiltration.

Fungal infections are still one of the main causes of death and complications after solid organ and bone marrow transplants. The authors evaluated the effect of continuous hemodiafiltration (CHDF) on the pharmacokinetics of fluconazole in liver transplant recipients. Six liver transplant patients (primary biliary cirrhosis, n = 2; fulminant hepatitis, n = 2; viral hepatitis, n = 2) were enrolled in this study. In one patient not receiving CHDF, the fluconazole levels increased with increasing dosages. In contrast, in patients undergoing CHDF, the dosage of fluconazole was increased from 100 mg/d to 200 mg/d, but fluconazole did not reach the targeted levels. It appears that the targeted trough level cannot be achieved by administration of fluconazole at a dosage of 100 to 200 mg/d during CHDF. A higher dosage (600-1000 mg/d) of fluconazole may be required to achieve the therapeutic drug level in patients undergoing CHDF. In patients undergoing CHDF, fluconazole was given at a dosage of 800 mg/d and reached the targeted levels. In addition, after CHDF, the dosage of fluconazole was decreased to 100 mg/d, and fluconazole reached the near-targeted trough level. These results demonstrate that CHDF removes fluconazole from the blood at an efficiently high rate, resulting in its ineffective blood level. To guarantee safe and effective fluconazole therapy, the trough levels should be monitored routinely during CHDF.

Adult↗