Biomedical subjects

A Ochiai

Publications and source records attributed to A Ochiai.

At least 145 records · Page 8Linked to original sources

PubMed1994

Analysis of regional differences of p53 mutation in advanced gastric carcinoma: relation to heterogeneous differentiation and invasiveness.

In order to examine the correlation of p53 mutation with heterogeneous histological differentiation and invasiveness of gastric carcinoma, we analyzed 46 areas (three to six per case) that were different histologically and anatomically in 12 advanced gastric carcinomas, shown previously to be positive for p53 mutation, using immunohistochemical, polymerase chain reaction-single strand conformation polymorphism, and direct DNA sequencing analyses. DNA derived from different sites in nine cases had the same pattern of p53 mutation, even in cases manifesting heterogeneous histology within a single tumor. Site difference of the p53 mutation was found in three cases: two showed no mutation in superficial tumor areas but presence of mutation in deep-infiltrating areas. In contrast, one case contained a mutation in the superficial area but not in the deep-infiltrating area. These results suggest that in most cases, tumor cells forming a single advanced gastric carcinoma, even though they may present a heterogeneous histology and deep invasion, seem to be derived from the same cellular clone.

Base Sequence↗

PubMed1994

Morphometric analysis of colorectal dysplasia with image processing.

Nuclear and structural abnormalities on the histological specimens of colorectal dysplasias were quantified by using 10 parameters. From the measured values, the following histological findings were obtained: progression from mild to severe dysplasia was associated with an increase in nuclear size, and nuclear arrangement became more irregular. There was, however, no difference between the nuclear size and arrangement in severe dysplasia and those in carcinoma. The nuclei were spindle shaped in mild and moderate dysplasia. On the other hand, they were relatively round in severe dysplasia and carcinoma. Structural abnormalities tended to increase with the histological abnormalities. These results correspond well with the histological abnormalities by which the pathologists grade dysplasia and diagnose carcinoma subjectively. Therefore, these 10 parameters might be useful for quantifying histological characteristics of colorectal dysplasias.

Cell Nucleus↗

PubMed1994

Alterations of the cadherin-catenin cell adhesion system in cancers.

The E-cadherin-mediated cell adhesion system acts as an "invasion suppressor" system, which is widely considered to be inactivated when the expression of E-cadherin is reduced and/or heterogeneous. To further investigate the molecular mechanisms responsible for dysfunction of this system in cancers, we examined human carcinoma cell lines lacking tight cell-cell adhesion. In KATO-III, established from stomach cancer, a point mutation of the E-cadherin gene resulted in a mRNA splicing error and markedly reduced E-cadherin expression. In another stomach cancer cell line, MKN 45, an 18-bp deletion of the E-cadherin gene caused a mRNA splicing error and a 4-amino-acid deletion, which was considered to alter the conformation around the key Ca(2+)-binding motif. In these two cell lines, the wild-type allele of the E-cadherin locus, which was assigned to chromosome 16q, was lost. Also in vivo, we found mutation of E-cadherin in breast cancers, where allele loss on chromosome 16 has frequently been reported. Thus, dysfunction of E-cadherin could be caused by a combination of the loss of one allele and a mutation in the remaining allele. Homologous deletion of part of the alpha-catenin gene, resulting in markedly reduced expression, was observed in a human lung cancer cell line, PC9. Recently, we also found mutations of beta-catenin in human carcinoma cell lines. These findings indicate the possible involvement of genetic abnormalities of various components in inactivation of the E-cadherin-mediated "invasion suppressor system" in cancers.

Binding Sites↗

PubMed1993

Cervical, mediastinal, and abdominal lymph node dissection (three-field dissection) for superficial carcinoma of the thoracic esophagus.

BACKGROUND: The recent increase in the number of esophageal carcinomas detected at an early stage has prompted debate about the most suitable treatment for them. METHODS: Forty-three patients with superficial esophageal carcinoma (SEC) underwent esophagectomy with cervical, mediastinal, and abdominal lymph node dissection (three-field dissection). On the basis of the pathologic data and results of surgery, the adequacy of treatment was discussed. RESULTS: Three patients with pTis tumor had no positive lymph nodes. Twenty patients (46.5%) had positive nodes in the resected specimen. Nineteen lesions (57.6% of submucosal cancers) with lymph node metastasis had invasion to the submucosa. Five patients with submucosal cancer (15.2% of submucosal cancers) had positive nodes in the neck. The lymph nodes along the right recurrent nerve and the right paracardiac nodes were the most frequent site of metastasis (16.3%), whereas the right paratracheal, infracarinal, infra-aortic arch, common hepatic, and celiac nodes had no metastasis. The operative mortality rate was 2.3%. Recurrent disease occurred in three patients with submucosal cancer. The 5-year survival rate after surgery was 73.2% for all 43 patients and 68.6% for patients with positive nodes. CONCLUSIONS: Esophagectomy with three-field lymph node dissection is recommended for patients with lesions diagnosed as submucosal cancer. Endoscopic mucosectomy is applicable as a first-choice treatment for patients with esophageal carcinoma at Tis.

Abdomen↗

PubMed1993

Germ-line p53 mutation is uncommon in patients with triple primary cancers.

We examined five patients with multiple primary cancers who had a history of three different types of primary cancers for germ-line p53 mutations. The germ-line p53 mutation was detected in a patient who conformed to the Li-Fraumeni syndrome, but not in the other four patients. The diagnosis of these four patients did not fall in the category of Li-Fraumeni syndrome. This result indicates that germ-line p53 mutations are uncommon even in patients with triple primary cancers.

Female↗

PubMed1993

p53 mutation in gastric cancer: a genetic model for carcinogenesis is common to gastric and colorectal cancer.

Mutation of the p53 tumour-suppressor gene in exons 5 through 8 was examined in 118 cases of gastric cancer (59 early gastric cancers and 59 advanced gastric cancers) using PCR-SSCP (polymerase-chain-reaction-single-strand-conformation polymorphism) analysis and direct sequencing. In early gastric cancer, mutations were found in 15 of 41 (37%) cases of the cohesive type, i.e., papillary adenocarcinoma, well to moderately differentiated tubular adenocarcinoma, and poorly differentiated adenocarcinoma with solid nests or focal tubular structures, but were not detected in 18 cases of the non-cohesive type, i.e., signet-ring-cell carcinoma and poorly differentiated adenocarcinoma growing in a scattered manner. In advanced gastric cancer, 25 of 59 (42%) cases of the cohesive type had p53 mutation. No significant association was found between p53 mutation and other histopathological parameters such as macroscopic classification, lymph-node involvement and depth of tumour invasion. Fifteen of 25 (60%) mutations in the advanced gastric-cancer group were accompanied by allele loss at the p53 gene locus. Eighty-three percent of mutations in early gastric cancer and 52% of mutations in advanced gastric cancer showed G:C-to-A:T transition, almost exclusively at CpG dinucleotide mutational hot spots, indicating that the spectrum of p53 mutation was similar to that of colorectal cancer. These data suggest that the p53 mutation occurs selectively in gastric cancer of the cohesive type from the intramucosal cancer stage.

Adenocarcinoma↗

PubMed1993

Synthesis and mitogenic activity of chiral lipopeptide WS1279 and its derivatives.

Optically active lipopeptide derivatives have been synthesized by the use of chiral glycerol derivatives. Lipopeptide WS1279 derivatives with (R)-glycerol moieties showed a higher mitogenic activity than those with the (S)-configuration. Various N-protected lipopeptide and N-deprotected derivatives showed increased mitogenic activity.

Amino Acid Sequence↗

PubMed1992

A monoclonal antibody capable of detecting new differentiation antigen of the stomach.

A monoclonal antibody (MAb) was raised against a gastric adenocarcinoma cell line TMK-1 that shows parietal cell differentiation. This MAb, an IgMK, named 20DII, reacted immunohistochemically with the intracytoplasmic secretory canalicular membranes of normal parietal cells of the stomach. In the fetal stomach at 4 months of gestation, the luminal surface of fundic epithelia and developing parietal cells had MAb20DII immunoreactivity, but at 6 months of gestation only parietal cells showed immunoreaction. Out of 133 gastric carcinomas, 98 (74%) had MAb20DII immunoreactivity. In the well-differentiated type, immunoreactivity was localized at the luminal surface of tumor cells and, in the poorly differentiated type, in the intracytoplasmic tubulovesicles of tumor cells. In Western-blot analysis, the antigenic molecule had a molecular weight exceeding 300 kDa in the tumor tissues, but only a 62-kDa immunoblot band was seen in the corresponding non-cancerous gastric mucosa. However, there was no correlation between the expression of high-molecular-weight antigens and the histological types of gastric carcinoma. These results suggest that 20DII antigen may be involved in differentiation of parietal cells in the fetal stomach and in stomach cancer.

Adenocarcinoma↗

PubMed1992

Differentiation of Clara cell (distal type) antigen in human fetal bronchial epithelial cell line (HFBE).

A human fetal bronchial cell line (HFBE) grew in an undifferentiated pattern under conventional culture conditions. Despite a somewhat fibroblastic shape, however, they still maintained an immuno-reactivity to cytokeratin, carcinoembryonic antigen (CEA) and epithelial membrane antigen (EMA). When grown on a collagen gel in a growth hormone-supplemented medium, their spindle shape became more conspicuous. With the additional supplement of 6 micrograms/ml vitamin A, most of the cells underwent differentiation by producing many bright inclusion bodies which proved to be strongly positive to periodic acid Schiff (PAS) and barely positive to alcian-blue (AB) staining. Electron microscopy revealed well-developed rough endoplasmic reticulum (rER), enlarged Golgi apparatus and many highly electron-dense secretory granules resembling those of Clara cells. Biochemical analysis demonstrated that HFBE cells cultured on collagen gel with vitamin A secreted products containing glycoconjugates of two different molecular weights. The higher molecular weight-product was identified as hyaluronic acid and the lower molecular weight-product as a mixture of neutral glycoproteins containing mainly N-linked glycoproteins whose glycans were of a complex type. While the secretion of hyaluronic acid was inhibited by vitamin A in a dose-dependent manner, that of the neutral glycoproteins was most enhanced by vitamin A in the range from the physiological concentration of 600 ng/ml to 6 micrograms/ml. A monoclonal antibody (SEC-41) generated against the secretory products with the lower molecular weight detected a glycoprotein of approximately 52 kd in the spent culture medium of differentiated HFBE cells. This antibody also reacted with the intra-cytoplasmic secretory granules in these cells. When tested on freeze-sectioned lung tissue, immunohistochemical reactivity of SEC-41 antibody was confined to Clara cells, some type II pneumocytes in the adult lung and respiratory epithelial cells of the fetal lung tissue. Moreover, this antibody could detect the secretory glycoproteins in the broncho-alveolar lavages (BAL) of two human cases. This paper has clearly demonstrated that cells derived from human fetal bronchial epithelium can be cultivated in an undifferentiated precursor state and under appropriate culture conditions they can be stimulated to undergo differentiation into a Clara cell type.

Cell Differentiation↗

PubMed1992

Relation between the biologic activities and chemical structures of synthetic microbial lipopeptide analogs in mice.

Mitogenicity, lethal toxicity, and antitumor activity against Meth A fibrosarcoma of chemically synthesized lipopeptide analogs, S-[2,3-bis(palmitoyloxy)-2R-propyl]-N-[(2,2,2)-tri- chloroethoxycarbonyl: Troc group]-cysteinyl-seryl-seryl-asparaginyl-alanine (compound KAB-2), which contain the amino acid sequence of lipopeptide in Escherichia coli, S-[2,3-bis(palmitoyloxy)- 2R-propyl]-N-(Troc- or amino-group)-cysteinyl-asparaginyl-seryl-glycyl-glycine (compound KAB-14 or -20), which is found in the amino acid sequence of lipopeptide in Streptomyces, and the compounds binding one to six amino acids, were examined. The analogs showed the mitogenic activity toward splenocytes of C3H/He mice. Low concentrations (0.4 and 2.0 micrograms/ml) of compounds KAB-20 and -21, which have five and six amino acids, respectively, increased the incorporation of [3H]thymidine better than a high concentration (50 micrograms/ml), suggesting that KAB compounds carrying amino groups exert better mitogenicity than KAB compounds carrying Troc group. The decrease of amino acid number in lipopeptide analogs appears to result in a lowering of mitogenicity at low concentrations. KAB-14 and KAB-2 did not exhibit the lethality at a high dose of 50 micrograms/mouse in galactosamine-loaded C57BL/6 mice. By twice intravenous injections of 50 micrograms against Meth A fibrosarcoma in BALB/c mice, KAB-2 showed a higher inhibitory effect than KAB-14. Based on these results, we concluded that the difference of amino acid sequence in the synthetic lipopeptides affects the potency of biologic activities.

Amino Acid Sequence↗

PubMed1991

Flow cytometric analysis of the expression of 9A3 antigen, E-cadherin and EGF receptor in TMK-1 stomach cancer cells.

We have previously produced a monoclonal antibody (MAb) against TMK-1 cells, a poorly differentiated stomach-cancer cell line, and designated the antigen as 9A3. Immunohistochemical analysis of various tumor tissues revealed that the expression of 9A3 antigen is specific for human adenocarcinoma. In the present study, we analyzed the expression patterns of 9A3 antigen on TMK-1 cells and compared them with the expression patterns of E-cadherin and epidermal-growth-factor (EGF) receptors, using immunofluorescent microscopy and flow cytometry. The flow cytometric analysis revealed that the TMK-1 cell population consists of 9A3-positive cells and 9A3-negative cells. The isolated 9A3-negative cell population generates 9A3-positive cells as they divide, whereas the isolated 9A3-positive cell population does not generate 9A3-negative cells. The 9A3-positive cells grow as tight colonies, whereas the 9A3-negative cell form loose colonies in soft agar culture. E-cadherin was expressed only in the 9A3-positive TMK-1 cells and not in the 9A3-negative cells. In contrast, EGF receptor was expressed in both cell populations. The 9A3 antigen was localized mainly at the cell-cell adhesion sites where E-cadherin was apparently condensed.

Adenocarcinoma↗

PubMed1991

Secretory differentiation and cell type identification of a human fetal bronchial epithelial cell line (HFBE).

A human fetal bronchial epithelial cell line (HFBE) grew in an undifferentiated pattern under conventional culture conditions. Despite a somewhat fibroblastic shape the cells maintained immunoreactivity to cytokeratin, carcinoembryonic antigen and epithelial membrane antigen. When grown on a collagen gel in a growth-hormone-supplemented medium, their spindle shape became more conspicuous. With an additional supplement of vitamin A (6 micrograms/ml), most of the cells underwent differentiation by producing many bright inclusion bodies which proved to be strongly positive with periodic acid-Schiff and weakly positive with alcian blue staining. Electron microscopy revealed a well-developed rough endoplasmic reticulum, an enlarged Golgi apparatus and many highly electron-dense secretory granules resembling those of Clara cells. Biochemical analysis demonstrated that HFBE cells cultured on collagen gel with vitamin A secreted hyaluronic acid and neutral glycoproteins containing mainly N-linked glycoproteins whose glycans were of a complex type. A monoclonal antibody (SEC-41) generated against the neutral glycoproteins detected a glycoprotein of approximately 52 kDa in the spent culture medium of differentiated HFBE cells. This antibody also reacted with the intracytoplasmic secretory granules in these cells. When tested on frozen sections of lung tissue, the immunohistochemical reactivity of the SEC-41 antibody was confined to Clara cells, some type II pneumocytes in the adult lung, and respiratory epithelial cells in the fetal lung. Moreover, this antibody could detect secretory glycoprotein in broncho-alveolar lavages from two patients. This paper clearly demonstrates that cells derived from human fetal bronchial epithelium can be cultivated in an undifferentiated precursor state and, under appropriate culture conditions, can be stimulated to undergo differentiation into a Clara cell type.

Bronchi↗

PubMed1991

Induction and characterization of secretory differentiation in human fetal bronchial epithelial cell line (HFBE) cultured on collagen gel in growth hormone and vitamin A-supplemented medium.

A type of secretory differentiation was induced and characterized in a human fetal bronchial epithelial cell line (HFBE), which was grown on a collagen substratum in a basal differentiative medium (BDM) containing growth hormones and with supplementation of various concentrations of vitamin A (VA). HFBE cells grown on a collagen gel in BDM with or without VA assumed a spindle shape with thick cytoplasm arranged in strands running parallel to each other. Under a phase-contrast microscope, cells cultured in the absence of VA possessed a small number of bright inclusion bodies, which proved to be positive to PAS and almost negative to alcian-blue (AB) staining. Electron microscopy revealed well-developed rough endoplasmic reticulum (rER), enlarged Golgi apparatus and a small number of high-density granules resembling serous or Clara cell granules. HFBE cells treated with VA at levels higher than 6 mu/ml showed a remarkable increase of the secretory granules and contained amorphous material in the rER. Addition of a low concentration of VA (6 ng/ml) only stimulated the growth of HFBE cells. In contrast, higher concentrations of VA significantly inhibited the growth and 3H-thymidine incorporation into DNA in a dose-dependent manner. HFBE cells cultured on collagen gel with VA secreted products with 2 different molecular weights into the medium. A high molecular weight-product, consisting of void volume fractions from a Bio-gel A 15-m column, was identified as hyaluronic acid based on the results obtained from the DEAE-ion exchange chromatography and specific enzymatic digestion. A low molecular weight-product fractionated on the A 15-m was tentatively identified as mainly neutral glycoproteins containing N-linked glycans. While the secretion of hyaluronic acid was inhibited by VA in a dose-dependent manner, the secretion of the neural glycoproteins was most enhanced by VA in the range from the physiological concentration of 600 ng/ml to 6 micrograms/ml. These biochemical data on the secretory products, together with the morphological findings, demonstrate that the HFBE cell line serves as a new model for investigating the cellular differentiation of human lung epithelium.

Bronchi↗

PubMed1991

Monoclonal antibodies against merokeratin from sheep's wool.

Four monoclonal antibodies designated as AMK-6, AMK-10, AMK-16 and AMK-27, were raised against merokeratin prepared from sheep's wool, and their cross-reactivity to epithelial cytokeratins were examined using immunoblot analysis and immunohistochemistry. AMK-16 which was specific to merokeratin in immunoblot analysis, demonstrated specific immunohistochemical staining of wool fibers of the sheep's skin. The other 3 monoclonal antibodies (AMK-6, -10, and -27) showed cross-reactivity towards epithelial cytokeratins with several molecular weights when examined by immunoblot analysis. However, each immunohistochemical staining of the sheep's skin with these monoclonal antibodies appeared to be cell type-specific. These results indicate that merokeratin and certain epithelial cytokeratins share many antigenic epitopes in common, and these monoclonal antibodies against merokeratin from sheep wool will be useful for the analysis of wool-forming cell differentiation.

Animals↗

PubMed1990

New functional cell-culture approach to pulmonary carcinogenesis and toxicology.

Modern pulmonary toxicology (including lung carcinogenesis) has, to assist its rapid development, constantly incorporated the knowledge obtained through cell and tissue-culture studies. While this has been carried out in rather a passive manner until quite recently, the currently necessary multi-disciplinary approach increasingly requires more active involvement of cell/tissue-culture techniques in this area. Our understanding in this regard is that one of such requirements is to establish a cell-culture system consisting of a single population of possible target cells for certain classes of hazardous inhalants. In addition, such target cells in culture should be able to function in a manner as closely resembling the situation in vivo as possible. In view of the culture techniques presently available, this requirement is probably too ideal to be met immediately. Nevertheless, efforts have been made in the last decade to achieve functioning cultures of Clara cells, type II pneumocytes or small mucus granule cells (SMGC), using undifferentiated cells obtained from animal and human fetuses. This attempt forms a sharp contrast to the usual approach, in that while the latter tries to keep the functions of adult cells in an already differentiated state, the former aims at inducing functional differentiation in undifferentiated cells by manipulating culture conditions. In carrying out these efforts, we have shown clear evidence that the type II pneumocytes and Clara cells induced in vitro are closely cognate and share a common precursor cell in culture, and that SMGC are at a pre-stage of differentiation to Clara cells. We have also shown an induced capacity for xenobiotic activation and conjugation in SMGC in culture. Our next plan is to prove similar activity (of mixed-function oxidase) in Clara cells and type II pneumocytes induced to differentiate in culture.

Animals↗

PubMed1990

Secretory differentiation of human fetal bronchial epithelial cells in culture. A study by histochemistry and electron microscopy.

Human fetal bronchial epithelial (HFBE) cells at 6-8 passages were cultivated on a collagen gel for 10 days. A basal differentiative medium (BDM), consisting of RPMI 1640 supplemented with hormones and growth factors, was employed. Histochemistry, scanning electron microscopy and transmission electron microscopy revealed that HFBE cells developed secretory granules when cultivated on collagen gel in BDM. They were electron-dense and stained positive for PAS but negative for alcian blue. On additional treatment with 8 micrograms/ml vitamin A (VA), the number of secretory granules was increased. Moreover, the HFBE cells lost their surface microvilli, and dilation of rough endoplasmic reticulum was more marked than in culture without VA.

Bronchi↗

PubMed1989

Establishment and characterization of cell line SFCC from clear cell adenocarcinoma of the uterine cervix.

A human cervical clear cell adenocarcinoma cell line was established and named SFCC. The tumor cells were obtained from ascites of a 39-year-old woman who underwent a radical hysterectomy. She had no history of exposure to diethylstilbestrol (DES). The histologic feature of the tumor cells at autopsy showed abundant clear cytoplasm with diastase digested glycogen granule growing in solid nest and tubular pattern. SFCC cells were continuously propagated in vitro during the past 29 months and grown in a monolayered sheet with a doubling time of about 67 hours. SFCC cells resembled the structure of the original tumor and had abundant glycogen granules, lipid droplets in the cytoplasm, and numerous microvilli. Immunohistochemically, SFCC cells had carcinoembryonic antigen (CEA) immunoreactivity in some parts of the cell population. Moreover, they had a relatively high amount of progesterone receptor (20.0 fmol/mg protein; kd, 6.6 nM) but did not have either an estrogen receptor or EGF receptor. The SFCC cell line secreted a high content of tissue peptide antigen (TPA) into the medium, indicating that the SFCC cell line is useful for analyzing the progesterone receptor and TPA production in clear cell adenocarcinoma of uterine cervix.

Adenocarcinoma↗

PubMed1989

Fatal and non-fatal methomyl intoxication in an attempted double suicide.

A 79-year-old man and his 73-year-old wife attempted double suicide by ingesting methomyl powder. The woman died 19 h after ingestion in spite of intensive care. At autopsy a large number of miliary hemorrhages were found in both thalami of the brain. Her husband, however, recovered after 10 days of treatment. Methomyl (CAS No. 16752-77-5, Lannate) in the biological materials was analyzed by gas chromatography-mass spectrometry. The methomyl concentration was 44 micrograms/g in the wife's serum sample collected 1 h after ingestion, and 0.2 microgram/g in the blood sample collected at autopsy. The methomyl concentration in the husband's blood sample collected 28 h after ingestion was from 0.01 to 0.1 microgram/g. It is suggested that prompt and adequate intensive care including a direct hemoperfusion is necessary to effect the recovery of patients with lethal blood levels of methomyl. The miliary hemorrhages found in the thalami of the brain are suspected to have been caused by asphyxia induced by methomyl intoxication.

Aged↗