Biomedical subjects

E Miyazaki

Publications and source records attributed to E Miyazaki.

At least 19 recordsLinked to original sources

PubMed2002

Denatured H-ferritin subunit is a major constituent of haemosiderin in the liver of patients with iron overload.

BACKGROUND AND AIMS: Iron is stored in hepatocytes in the form of ferritin and haemosiderin. There is a marked increase in iron rich haemosiderin in iron overloaded livers, and ferric iron in amounts exceeding the ferritin and haemosiderin binding capacity may promote free radical generation, causing cellular damage. The aim of this study was to characterise hepatic haemosiderin using four antibodies specific for either native or denatured H/L-ferritin subunits. METHODS: Ferritin and haemosiderin were prepared from the livers of three patients with post-transfusional iron overload. The assembled ferritin molecules were analysed by non-denaturing polyacrylamide gel electrophoresis (PAGE)-immunoblotting. Ferritin subunits in the haemosiderin fraction were assessed by denaturing sodium dodecyl sulphate (SDS)-PAGE-immunoblotting. Distribution of native and denatured ferritin subunits in hepatocytes was examined by immunogold electron microscopy. RESULTS: Non-denaturing PAGE-immunoblot analyses showed that the assembled liver ferritins were recognised by the antibodies for native ferritins and not by those for the denatured subunits. Both SDS-PAGE-immunoblot and immunogold electron microscopic analyses disclosed that haemosiderin of iron overloaded liver reacted predominantly to the monoclonal antibody for the denatured H-ferritin subunit, to a lesser degree to that for denatured L-ferritin, and very weakly, if any, with antibodies for native H-ferritin or L-ferritin. CONCLUSIONS: These results suggest that in iron overloaded liver, haemosiderin consists predominantly of denatured H-ferritin subunits.

Adult↗

PubMed2002

Alpha smooth muscle actin positive stromal cells in gastric carcinoma.

AIMS: To investigate the distribution and roles of alpha smooth muscle actin (ASMA) positive stromal cells (ASMA+ cells), which belong to the myofibroblast group, within gastric carcinomas, with reference to three histological types (diffuse type, intestinal type, and solid type). METHODS: In total, 74 surgically resected gastric carcinomas (24 diffuse type, 43 intestinal type, and seven solid type) were examined. ASMA positive and high molecular weight caldesmon (HCD) negative stromal cells were regarded as ASMA+ cells. The distribution of CD34 positive stromal cells (CD34+ cells) was also analysed immunohistochemically. RESULTS: In the 24 diffuse-type gastric carcinomas, six of the 13 carcinomas invading the subserosa had ASMA+ cells in the tumour stroma, whereas all six diffuse-type gastric carcinomas confined to the submucosa and all five invading the muscularis propria had no ASMA+ cells in the tumour stroma. In the 43 intestinal-type gastric carcinomas, only five of the 21 carcinomas confined to the submucosa had ASMA+ cells in the tumour stroma, whereas 21 of the 22 intestinal-type gastric carcinomas invading the muscularis propria and the subserosa had ASMA+ cell bundles in the tumour stroma. The distribution of CD34+ cells in diffuse-type and intestinal-type gastric carcinomas was similar to that seen in a previously published series. All seven solid-type gastric carcinomas examined had ASMA+ cells but not CD34+ cells in the tumour stroma. No stromal cells double positive for ASMA and CD34 were detected within the diffuse-type tumours examined. CONCLUSIONS: These results suggest that ASMA expression in stromal cells is associated with tumour stroma formation of diffuse-type gastric carcinomas invading the subserosa, intestinal-type gastric carcinomas invading the muscularis propria and subserosa, and solid-type gastric carcinomas.

Actins↗

PubMed2002

Lack of CD34 positive stromal cells within angiomyomas (vascular leiomyomas).

AIMS: To investigate the role of CD34 positive stromal cells in the morphogenesis and tumour growth regulation of angiomyomas (vascular leiomyomas). METHODS: Histochemical analysis using monoclonal antibodies to CD34 and CD31 was performed in 10 angiomyomas and their adjacent soft tissue. RESULTS: CD34 positive stromal cells were not seen within the tumour tissue; the thick walled vessels within the tumours lacked CD34 positive stromal cells. In contrast, bundles of CD34 positive stromal cells were detected at the tumour border of all of the angiomyomas and in the adventitial tissue of the surrounding normal vessels. CONCLUSIONS: The lack of CD34 positive stromal cells within an angiomyoma is associated with the characteristic morphology of an angiomyoma.

Angiomyoma↗

PubMed2001

NHE6 protein possesses a signal peptide destined for endoplasmic reticulum membrane and localizes in secretory organelles of the cell.

The NHE6 protein is a unique Na(+)/H(+) exchanger isoform believed to localize in mitochondria. It possesses a hydrophilic N-terminal portion that is rich in positively charged residues and many hydrophobic segments. In the present study, signal sequences in the NHE6 molecule were examined for organelle localization and membrane topogenesis. When the full-length protein was expressed in COS7 cells, it localized in the endoplasmic reticulum and on the cell surface. Furthermore, the protein was fully N-glycosylated. When green fluorescent protein was fused after the second (H2) or third (H3) hydrophobic segment, the fusion proteins were targeted to the endoplasmic reticulum (ER) membrane. The localization pattern was the same as that of fusion proteins in which green fluorescent protein was fused after H2 of NHE1. In an in vitro system, H1 behaved as a signal peptide that directs the translocation of the following polypeptide chain and is then processed off. The next hydrophobic segment (H2) halted translocation and eventually became a transmembrane segment. The N-terminal hydrophobic segment (H1) of NHE1 also behaved as a signal peptide. Cell fractionation studies using antibodies against the 15 C-terminal residues indicated that NHE6 protein localized in the microsomal membranes of rat liver cells. All of the NHE6 molecules in liver tissue possess an endoglycosidase H-resistant sugar chain. These findings indicate that NHE6 protein is targeted to the ER membrane via the N-terminal signal peptide and is sorted to organelle membranes derived from the ER membrane.

Amino Acid Sequence↗

PubMed2001

Elevated expression of interleukin-18 in the granulomatous lesions of muscular sarcoidosis.

In an attempt to understand the role of interleukin-18 (IL-18) in the pathogenesis of sarcoidosis, we examined the expression of IL-18 in normal muscle and in muscle biopsies from six patients with muscular sarcoidosis. Western blot analysis demonstrated that IL-18 was identified only in homogenates of granulomatous muscle tissues, but not in normal muscle tissue homogenates. By immunohistochemistry, strongly IL-18-positive cells were distributed predominantly at the boundary zone of the granulomas. They were recognized as activated macrophages by double staining with anti-CD68. Epithelioid cells showed only faint reactivity. Serum IL-18 levels of patients with sarcoidosis were significantly increased compared to those of healthy volunteers. Unlike protein expression, IL-18 mRNA expression was detected even in normal muscles. Our results coupled with those of previous investigations demonstrating activity of IL-18 in inducing interferon-gamma production suggest a significant role of IL-18 in the pathogenesis of sarcoidosis.

Adult↗

PubMed2001

Multiple gastrointestinal atresias result from disturbed morphogenesis.

Multiple gastrointestinal atresias (MGA) have been reported to account for 6% to 32% of all intestinal atresias. Controversy exists regarding the pathogenesis. Many investigators believe MGA to be the result of multiple ischemic infarctions of the intestinal tract. However, some have suggested that MGA results from a malformative process early in fetal life. Prenatal exposure to adriamycin in a rat model has been reported to lead to a spectrum of tracheoesophageal and associated malformations of the gastrointestinal tract, including intestinal atresias, identical to these observed in humans. The aim of this study was to determine the incidence and histopathologic findings of MGA in order to understand the pathogenesis. Timed-pregnant Sprague-Dawley rats were injected with adriamycin (1.75 mg/kg) in nine different gestational-day protocols. MGA was only seen in those rats who received adriamycin on gestational days 7, 8, and 9. The litters were recovered on day 21 by cesarean section. The digestive tracts (DT) of the fetuses were harvested for macroscopic and microscopic examination. Ten rats who received adriamycin on gestational days 7, 8, and 9 produced 87 newborns; 1 was damaged during dissection. DT anomalies occurred in 80 (93%) of the 86 newborns; 94% of these demonstrated MGA. There was a very high incidence of associated anomalies in newborns with MGA. Histologically, the blind-ending atresias showed different degrees of villous hyperplasia with or without intraluminal material. This is the first report demonstrating a high rate of occurrence of MGA in the adriamycin rat model. The injection of adriamycin early in gestation, the high incidence of associated malformations, and the anatomic and histologic findings in MGA indicate that MGA is a result of a malformative rather than an ischemic process.

Animals↗

PubMed2001

Eosinophil-induced liver injury: an experimental model using IL-5 transgenic mice.

BACKGROUND/AIMS: In certain liver diseases, activated eosinophils are considered to be important effector cells in addition to T-cell-mediated cytotoxicity. No experimental model, however, has been developed for in vivo analysis of the cytotoxic mechanisms. METHODS: Interleukin-5 (IL-5) transgenic mice (C3H/HeN-TgN(IL-5)Imeg), which exhibit marked eosinophilia without liver injury, were injected once with 25 microg of lipopolysaccharide (LPS) intraperitoneally. The mice were sacrificed weekly and eosinophilic injuries were assessed microscopically. To clarify the role of Kupffer cells and tumor necrosis factor-alpha (TNF-alpha) in the liver injury, gadolinium chloride (GdCl3) and anti-TNF-alpha neutralizing antibody were administrated before the LPS injection. RESULTS: Two weeks after injection, transgenic mice exhibited marked infiltration of eosinophils and extensive lobular necrosis. Transmigration of eosinophils through vascular endothelium and degranulation of eosinophil cytotoxic granules in inflamed areas were observed. These eosinophilic injuries were transient, but liver-specific. Pre-administration of GdCl3 and anti-TNF-alpha markedly reduced the hepatic inflammation, suggesting that LPS-activated Kupffer cells play a key role in producing the cytotoxicity of eosinophils by releasing TNF-alpha. CONCLUSIONS: We have established an experimental model of eosinophil-induced liver injury using IL-5 transgenic mice. Since this model is simple and highly reproducible, it will be useful for analysis of in vivo cytotoxic mechanisms of eosinophils.

Animals↗

PubMed2001

Goblet cell carcinoid of the appendix: Investigation of the expression of beta-catenin and E-cadherin.

Goblet cell carcinoids are rare neoplasms that predominantly occur in the appendix. In this report we present a case of goblet cell carcinoid of the appendix. A 58-year-old male patient complaining of pain in the right lower quadrant was diagnosed with acute appendicitis and underwent an appendectomy. Histological examination of the resected appendix revealed goblet cell carcinoid. Infiltration of tumor cells beyond the appendix was observed and the surgically resected margin was positive for tumor cells. Carcinoembryonic antigen (CEA) was diffusely detected by immunohistochemistry, and cytokeratin 20, neuron-specific enolase (NSE), chromogranin A and serotonin were focally observed in the tumor cells. The expression of beta-catenin and E-cadherin was investigated to compare with that of typical rectal carcinoids (n = 3) and colon adenocarcinomas (n = 3). In normal colonic and rectal mucosae, beta-catenin and E-cadherin stained positive on the plasma membrane. In the case reported here, beta-catenin showed a preserved expression on the plasma membrane of goblet cell carcinoid; a pattern similar to typical carcinoids rather than to adenocarcinomas. However, E-cadherin demonstrated a reduced expression on the plasma membrane of the tumor cells. This staining pattern was identical to those both of carcinoids and of adenocarcinomas. These findings suggest the possibility that, in some cases, the adherens junctions of goblet cell carcinoids are similar to those of typical carcinoids rather than to those of adenocarcinomas.

Appendix↗

PubMed2001

Adult-onset herpes simplex virus hepatitis with diffuse myofibroblastic transformation of hepatic stellate cells (Ito cells) in non-necrotic areas.

The myofibroblastic transformation of hepatic stellate cells (HSC; also known as Ito cells) usually occurs following necrosis of adjacent liver cells. No report has previously found that such a transformation occurs in herpes simplex virus (HSV) hepatitis. We present an autopsy case of HSV hepatitis with myofibroblastic transformation of HSC that is different from the usual transformation of HSC. The patient was a 66-year-old woman who had received various therapies for cutaneous T-cell lymphoma. An autopsy revealed submassive hepatic necrosis with hemorrhage due to HSV hepatitis. HSV infection was confirmed by DNA in situ hybridization in liver tissue. Immunohistochemical staining for alpha-smooth muscle actin (ASMA) showed a strong positive reaction in almost all of the HSC in non-necrotic areas. However, in necrotic areas, the HSC were completely negative for ASMA. These findings indicate that not only liver cells but also HSC can become necrotic in HSV hepatitis. In contrast, in non-necrotic areas, almost all of the HSC showed active transformation to myofibroblasts.

Actins↗

PubMed2001

Malignant phyllodes tumor of the breast with expression of osteonectin and vinculin.

Phyllodes tumor is a very rare neoplasm which accounts for 2.5% of all fibroepithelial lesions of the breast. The mesenchymal component of a malignant phyllodes tumor frequently contains heterologous components. We report a case of malignant phyllodes tumor. The patient was a 40-year-old woman with a lump on the left breast. Histological examination revealed the lump to be a malignant phyllodes tumor with foci of liposarcomatous differentiation. The mesenchymal tumor cells, including those in the liposarcomatous components, were found to express vimentin, osteonectin and vinculin. However, they showed no immunoreaction to CAM 5.2, desmin, alpha-smooth muscle actin (ASMA), neuron-specific enolase (NSE) nor S-100. Ultrastructurally, the mesenchymal tumor cells were found to have abundant cytoplasmic organelles, but there was no evidence showing their differentiation to myofibroblasts. Further studies will be necessary to elucidate the significance of vinculin and osteonectin expression in malignant phyllodes tumor.

Adult↗

PubMed2001

Expression of CD9/motility-related protein 1 (MRP-1) in renal parenchymal neoplasms: consistent expression in papillary and chromophobe renal cell carcinomas.

CD9 is a glycoprotein that is abundant in hematopoietic cells. Recently, it has been reported that CD9 is also present in the human kidney. In this article, we investigated the expression of CD9 using an immunohistochemical technique. We also studied the expression of CD9 protein and messenger RNA (mRNA) in tissue samples of some renal tumors using immunoblotting and reverse-transcription polymerase chain reaction (RT-PCR) analysis. Immunohistochemically, all tumors of papillary and chromophobe renal cell carcinomas (RCCs) and oncocytomas expressed CD9. In addition, CD9 was expressed in 31 of 66 conventional RCCs and 1 of 4 collecting duct carcinomas. On immunoelectron microscopy, CD9 was identified on the plasma membrane of a conventional RCC. The presence of CD9 protein in normal kidneys and various renal tumors, except for a collecting duct carcinoma and an oncocytoma, was confirmed by immunoblotting. On RT-PCR analysis, the expression of CD9 mRNA was observed in 1 normal kidney, 2 conventional RCCs, and 1 oncocytoma. The frequency of immunohistochemical CD9 positivity was significantly higher in papillary and chromophobe RCCs than in collecting duct carcinomas and conventional RCCs, respectively. These results suggest that CD9 may be a beneficial marker in the differential diagnosis between papillary RCCs and collecting duct carcinomas and also between chromophobe and conventional RCCs.

Adult↗

PubMed2001

Characterization of the human Fc gamma RIIB gene promoter: human zinc-finger proteins (ZNF140 and ZNF91) that bind to different regions function as transcription repressors.

Expression of the human low-affinity Fc receptors for IgG (human Fc gamma RII) is differentially regulated. We report here the characterization of the promoter structure of the human Fc gamma RIIB gene and the isolation of the promoter region-binding proteins by a yeast one-hybrid assay. The minimal 154-bp region upstream from the transcription start site of the human Fc gamma RIIB gene was shown to possess promoter activity in a variety of cells. An electrophoretic mobility shift assay indicated that multiple nuclear factors in cell extracts bind to the two regions [F2-3 (-110 to -93) and F4-3 (-47 to -31)] of the human Fc gamma RIIB gene promoter. Mutation analysis indicated that GGGAGGAGC (-105 to -97) and AATTTGTTTGCC (-47 to -36) sequences are responsible for binding to nuclear factors respectively. By using GGGAGGAGC and AATTTGTTTGCC as bait sequences, we cloned two zinc-finger proteins (ZNF140 and ZNF91) that bind to the F2-3 and F4-3 regions within the promoter of the human Fc gamma RIIB gene respectively. When the ZNF140 and ZNF91 were transfected with reporter plasmid, both showed repressor activity with additive effects. Thus, these results indicate that these cloned ZNF140 and ZNF91 proteins function as repressors for the human Fc gamma RIIB transcription.

5' Untranslated Regions↗

PubMed2001

Paxillin: application of immunohistochemistry to the diagnosis of chromophobe renal cell carcinoma and oncocytoma.

Paxillin is a cytoskeletal protein that was recently identified as a component of focal adhesions and links between F-actin and integrin. In this study, 91 renal tumors--65 conventional renal cell carcinomas (RCCs), 14 papillary RCCs, 6 chromophobe RCCs, 4 collecting duct carcinomas, 2 oncocytomas--were investigated for the immunohistochemical expression of paxillin. In a normal kidney, paxillin was predominantly expressed in the cytoplasm of distal tubules, loops of Henle, collecting ducts, and vascular smooth muscle cells. In all of the chromophobe RCCs and oncocytomas, strong expression of paxillin was observed in the tumor cytoplasm. In contrast to these tumors, conventional RCCs, papillary RCCs, and collecting duct carcinomas showed negative reactions for paxillin except for one case in each subgroup with weak reactivity. An immunoblot analysis confirmed the presence of paxillin in healthy kidney, chromophobe RCC, and oncocytoma. These data suggest that paxillin possibly plays a role in signal transductions as a focal adhesion intervening between tumor cells and the extracellular matrix in renal tumors with collecting duct phenotypes such as chromophobe RCCs and oncocytomas, but not in conventional RCCs. In addition, paxillin may be an available marker in distinguishing chromophobe RCCs from conventional or papillary RCCs.

Adenoma, Oxyphilic↗

PubMed2001

CD34 positive stromal cells in gastric adenocarcinomas.

AIMS: To investigate the role of CD34 positive stromal cells, namely dendritic interstitial cells, in gastric carcinomas, the distribution of CD34 positive stromal cells in gastric adenocarcinomas (GCs), with special reference to two histological types (diffuse (D-type) and intestinal (I-type)), was examined. METHODS: In total, 55 surgically resected GCs (15 D-type and 40 I-type) and their normal tissues were examined. To distinguish CD34 positive stromal cells from vascular endothelial cells and to recognise the tumour border, immunostaining for CD34, CD31, and low molecular weight cytokeratins was performed. RESULTS: In the 15 D-type GCs, eight of the nine D-type GCs invading the muscularis propria and subserosa had a large number of CD34 positive stromal cells in the tumour stroma, whereas all six D-type GCs confined to the submucosa had no CD34 positive stromal cells in the tumour stroma. All of the 40 I-type GCs had no CD34 positive stromal cells, regardless of tumour depth. CONCLUSIONS: These results suggest that CD34 expression in stromal cells is associated with progression of D-type GCs, and that absence of expression is also seen in I-type GCs that are progressing.

Adenocarcinoma↗

PubMed2001

[A case of chronic hypersensitivity pneumonitis due to wild pigeons].

A 61-year-old woman was admitted to the Oita Medical University Hospital because of a nonproductive cough and exertional dyspnea. Interstitial changes had been seen on her chest radiograph 5 years previously, but no respiratory symptoms were identified at that time. On admission, chest radiography revealed linear and ground-glass opacities in the middle and lower lung fields. Computed tomography provided evidence of bronchiectasis and micro-honeycombing of the lungs, while lymphocyte and neutrophil counts in the bronchoalveolar lavage fluid were increased. Transbronchial lung biopsy demonstrated alveolitis and Masson's bodies. The patient was not a pigeon breeder, but she could have been exposed to pigeons at her workplace. Indeed, she had specific antibodies against pigeon serum and droppings, and her peripheral lymphocytes showed proliferation in response to pigeon serum. A positive provocation test involving inhalation of pigeon serum confirmed that she had chronic hypersensitivity pneumonitis caused by allergy to pigeons. This is a rare case of chronic hypersensitivity pneumonitis associated with wild pigeons, that progressed to pulmonary fibrosis. Antigen provocation testing proved to be of great value.

Alveolitis, Extrinsic Allergic↗

PubMed2000

Transforming growth factor-beta 1 derived from biliary epithelial cells may attenuate alloantigen-specific immune responses.

Immune response to liver allografts may be different from that to other organ transplants since immunological manipulation easily attenuates immune-response to liver allografts. Numerous studies on the alloantigen-specific immune response have been carried out, however, the precise mechanisms involved in this attenuation are not clear yet. Here we suggest the attenuation of alloantigen-specific immune response by TGF-beta 1 derived from biliary epithelial cells. The transforming growth factor-beta 1 (TGF-beta 1) expression in rat liver was examined immunohistologically. Rat biliary epithelial cells (BEC) were purified from the perfused liver and added to allogeneic mixed lymphocyte reaction (allo-MLR) to assess their attenuating potential on allo-MLR and alloantigen-specific cytotoxic T lymphocyte (allo-CTL) induction. Immunohistological investigation revealed the expression of TGF-beta 1 in biliary epithelial cells. Both purified biliary epithelial cells and TGF-beta 1 attenuated allo-MLR and allo-CTL induction in a dose-dependent manner, and anti-TGF-beta 1 antibody partially relieved this attenuation. This study reveals that biliary epithelial cells, the major target cells of allo-antigen specific immune response, contain TGF-beta 1 and that they have a capacity to attenuate allo-MLR and allo-CTL induction.

Animals↗

PubMed2000

Antenatal dexamethasone administration inhibits smooth-muscle-cell DNA synthesis in pulmonary-arterial media in nitrofen-induced congenital diaphragmatic hernia in rats.

The aim of this study was to investigate the effect of antenatal glucocorticoid therapy on smooth-muscle-cell (SMC) DNA synthesis in the pulmonary arteries (PA) in a nitrofen-induced congenital diaphragmatic hernia (CDH) rat model following nitrofen administration on day 9.5 of gestation. Antenatal dexamethasone (DEX) was given intraperitoneally on days 18.5 and 19.5 of gestation. Bromodeoxyuridine (BrdU) was injected via a jugular vein into the dam 1 h before the fetuses were killed by cesarean section at term. The fetuses were divided into three groups: group I (n = 10): normal controls; group II (n = 10): nitrofen-induced CDH; group III (n = 10): nitrofen-induced CDH with antenatal DEX treatment. Immunostaining of the lungs with anti-BrdU antibody was obtained by a standard avidin-biotin complex method. The number of immunopositive cells in the PA media and adventitia were counted using an image analyzer and analyzed statistically. The number of BrdU-immunopositive cells in the media was significantly increased in group II (16.83 +/- 3.01) compared to groups I (9.16 +/- 2.20) and III (6.83 +/- 1.70) (P < 0.01). There was no significant difference between groups I and III. The number of BrdU-immunopositive cells in the adventitia was not significantly different between the three groups. Antenatal DEX treatment inhibits SMC DNA synthesis in PA media in CDH lungs. This may be a possible mechanism by which antenatal DEX prevents structural PA changes in nitrofen-induced CDH in rats.

Animals↗

PubMed2000

Expression of UDP-GalNAc: polypeptide N-acetylgalactosaminyltransferase isozymes T1 and T2 in human colorectal cancer.

Uridine diphosphate (UDP)-GalNAc: polypeptide N-acetylgalactosaminyltransferase (GalNAc transferase) catalyzes the initial step in mucin type O-glycosylation, and its expression has been assumed to be altered between normal epithelial cells and cancer cells. We studied the alteration of GalNAc transferase expression during the carcinogenesis of human colorectal epithelial cells. We produced polyclonal antibodies against synthetic polypeptides with specific sequence to two GalNAc transferase isozymes, T1 and T2. Surgically resected specimens from 50 patients with colorectal cancer were immunohistochemically stained, and the staining grade (percentage of positively stained cells) was compared between cancer and its normal counterpart in the same specimen. Significant signals for both T1 and T2 expression were seen in the supranuclear region of normal and cancer cells, indicating the subcellular localization of the enzymes in the Golgi apparatus. The prevalence of positive staining for T1 and T2 expression in colorectal cancer was significantly higher than that in normal epithelium (P < 0.05). However, the difference in staining grades between cancer and normal tissues varied in each patient. These results indicate that there is variability in the expression patterns of GalNAc transferase isozymes in normal and cancerous cells colorectal among individuals.

Adenocarcinoma↗