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Biomedical subjects

K Sugano

Publications and source records attributed to K Sugano.

At least 181 records · Page 10Linked to original sources
PubMed1993

Western blot analysis of glycoproteins bearing Lewis(a) and sialyl-Lewis(a) antigens in human colorectal mucosa.

Glycoproteins (GPs) bearing Lewis(a) and sialyl-Lewis(a) antigens (Le(a), sialyl-Le(a)) derived from human colorectal carcinomas and their surrounding non-neoplastic mucosa (normal mucosa) were analyzed using Western blotting. GPs bearing Le(a) were detected mainly as segmental bands of M(r) 310, 220, 160, and 80 kDa in 80% of the normal mucosa, but these GPs were detected predominantly as broad bands ranging from high to low molecular weight (MW) in 71% of the carcinoma tissues. GPs bearing sialyl-Le(a) were detected only in 23% of the normal mucosa and limited on huge MW bands, i.e., more than 400 kDa, whereas these GPs were detected predominantly as broad bands in 49% of the carcinoma tissues. In the cases with lymph node metastasis, the MW of GPs bearing sialyl-Le(a) varied over a wide range and were detected as broad bands, compared with the cases without metastasis. In conclusion, the MW of GPs bearing Le(a) and sialyl-Le(a) in normal colorectal mucosa was different from that in colorectal carcinomas. That is, the MWs of GPs bearing Le(a) varied more in carcinoma tissues, and the GPs bearing sialyl-Le(a) from carcinoma tissues had lower MWs than those from normal mucosa. It was, furthermore, suggested that the increased expression of lower MW GPs bearing sialyl-Le(a) are associated with an increased metastatic potential of the tumor cells.

Blotting, Western↗
PubMed1993

Helicobacter pylori, dietary factors, and atrophic gastritis in five Japanese populations with different gastric cancer mortality.

In a cross-sectional study of 634 men aged 40 to 49 years, randomly selected from five areas of Japan with different rates of gastric cancer mortality, 121 men of 624 evaluated were diagnosed as having atrophic gastritis through serum pepsinogen I < 70 ng/ml and the pepsinogen I (PGI)/pepsinogen II (PGII) ratio < 3.0. We examined the relation of Helicobacter pylori (H. pylori) antibodies and dietary factors, including plasma level of antioxidant micronutrients, to the presence of atrophic gastritis. Presence of H. pylori IgG antibodies was associated with increased risk of atrophic gastritis (odds ratio [OR] = 1.9, 95 percent confidence interval [CI] = 1.1-3.3). As the level of plasma beta-carotene increased, we found a steady decrease in the risk of atrophic gastritis (OR for second quartile = 0.7, third quartile = 0.6, fourth quartile = 0.4, with CI = 0.2-0.8). Frequent intake of yellow vegetables also was associated with lower risk, while frequent intake of soybean products was related to increased risk. Although H. pylori antibodies, beta-carotene level, and intake of soybean products were all significant in the multivariate analysis, these factors did not explain the differences in atrophic gastritis prevalence among the five regions. The analysis of these risk factors in relation to each pepsinogen marker showed that although both H. pylori infection and low plasma beta-carotene were associated with the decreased level of serum PGI/II ratio, the former was derived from the increase of PGII, which is common in early stage of atrophic gastritis, and the latter from the decrease of PGI, which is specific to severe atrophic gastritis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Systematic analysis of glycosphingolipids in the human gastrointestinal tract: enrichment of sulfatides with hydroxylated longer-chain fatty acids in the gastric and duodenal mucosa.

The composition of the glycosphingolipids of the human gastrointestinal tract was studied. The major neutral glycosphingolipids were ceramide monohexosides (e.g., GalCer, GlcCer), LacCer, Gb3Cer, Gb4Cer and more polar ones with more than four sugars, whereas neither Gg3Cer nor Gg4Cer were present. The acidic glycosphingolipids consisted of sulfatides and gangliosides such as GM3, GM1, GD3 and GD1a. Also a large amount of sulfatides was found in the gastric mucosa and duodenum. The concentrations of sulfatides in the fundic mucosa, antral mucosa and duodenum amounted to 416.0, 933.8 and 682.9 nmol/g of dry weight, respectively, exceeding those in the gastric mucosa and kidney of other mammals. The major molecular species of the sulfatides were identified as I3SO3-GalCer with hydroxylated longer-chain fatty acids based on the analyses by gas-liquid chromatography and negative ion fast-atom bombardment mass spectrometry. In contrast, gangliosides in these regions showed a tendency to be lower than sulfatides, and the molar ratios of sulfatides to gangliosides were about 2.0, whereas those in other parts were less than 0.5. A high content of sulfatides in the gastric and duodenal mucosa, where mucosa is easily insulted by acid, pepsin and bile salts, may be closely related to their roles in mucosal protection.

Carbohydrates↗
PubMed1993

Negative feedback regulation of acid secretion: linkage of acid secretion and mucosal defense.

To regulate inappropriate or excessive acid secretion that may be harmful not only to surrounding mucosal cells but also parietal cells themselves, versatile mechanisms operate to control acid secretion. In this article elaborate mechanisms that participate in the control of acid secretion are described with our data and a review of relevant findings in the literature concerning the action or secretion of key regulatory molecules. The analysis of the regulatory mechanisms revealed that appropriate secretory control can be achieved by multiple feedback regulations, which are closely coordinated with mucosal defense. In the feedback circuits, the regulatory factors cannot be simply categorized into either aggressive or defensive factors. Therefore we propose that the mucosal integrity and tissue homeostasis would be better understood by a feedback loop model rather than by a dualistic balance model.

Animals↗
PubMed1993

ErbB-2 protein levels in nipple discharge: role in diagnosis of early breast cancer.

The levels of c-erbB-2 oncoprotein (ErbB-2 protein) in nipple discharge were evaluated together with those of carcinoembryonic antigen (CEA) in 9 patients with breast cancer, 2 patients with borderline lesions, 8 patients with intraductal papilloma, and 19 patients with fibrocystic change. When the tentative cutoff value was set at 40 ng/ml in the nipple discharge, elevated ErbB-2 protein levels were found in all 3 patients with palpable breast cancer and 3 of the 6 patients with nonpalpable cancer. Two of the 8 patients with intraductal papilloma had high ErbB-2 protein levels. A combination test with CEA resulted in positive detection in all cancer patients. Two patients with borderline lesions, 2 with intraductal papilloma and 2 with fibrocystic change were positive in a combination test. In addition, elevated ErbB-2 protein levels in nipple discharge correlated well with the overexpression of ErbB-2 protein in the tumor. All the patients with ErbB-2 protein levels over 100 ng/ml in their nipple discharge had comedo or solid intraductal carcinomas. Thus, measurement of ErbB-2 protein levels in nipple discharge can assist in the diagnosis of intraductal carcinoma and also in detecting tumors with a high proliferation rate and an overexpression of ErbB-2 protein: usually comedo or solid carcinomas.

Adult↗
PubMed1993

[Sensitive detection of K-ras oncogene codon 12 mutations by nested PCR using mismatched primers and selective digestion of non-mutated PCR fragments with restriction enzyme].

Sensitive detection of K-ras oncogene mutation at codon 12 using nested polymerase chain reactions (PCR) with mismatched primers combined with selective digestion of nonmutated DNA fragments after the first PCR amplification was reported by Levi S, et al. (Cancer Res 51:3497-3502, 1991). We examined the usefulness of this novel technique in cell lines carrying various K-ras codon 12 mutations and clinical samples such as colon carcinoma tissue, corresponding normal colonic mucosa and pancreatic juice obtained from the patients with pancreatic carcinoma undergoing endoscopic retrograde pancreatography (ERP). In analysis of tumor cell lines carrying mutated K-ras at codon 12, the fragment length of the amplified DNA was 135 bp after digestion using restriction enzyme BstN1, whereas those of nonmutated cell lines were 106 bp. This method was highly sensitive to detect mutant DNA diluted at a ratio of 2048 fold with normal DNA samples obtained from peripheral blood lymphocytes. In analysis of clinical samples, 4 out of 10 colorectal carcinoma tissues were positive for K-ras gene mutation at codon 12, however, no mutations were detected in corresponding normal colonic mucosa. In analysis of pancreatic juice taken from the patients with pancreatic carcinoma, 1 out of 3 samples were positive for K-ras mutation at codon 12. Thus, this novel approach was thought to be useful for detection of minimum number of cancer cells from compound samples containing larger amounts of normal cells.

Cells, Cultured↗
PubMed1993

[Adhesion of Helicobacter pylori--role of glycolipid adhesion receptors].

In the gastric mucosa, the composition of acidic glycolipids has unique feature of enrichment of sulfatides over gangliosides. Immunohistochemical staining using a monoclonal antibody demonstrated that the sulfated glycolipids specifically localized on surface epithelial cells. Moreover, cultured gastric mucosal cells actively synthesized sulfated glycolipids. We have also shown that it may be recognized as an adhesion receptor by Helicobacter pylori (HP). Since other investigators have proposed various other substances as adhesion receptors for HP, the mechanism of adhesion by HP might be more complex and involve several adhesion molecules. When given orally, sulfatides protected gastric mucosa from acid-ethanol induced damage. Specific localization and synthesis of sulfatides in the surface epithelial cells, along with their gastroprotective action, are reminiscent of the surface-active phospholipids which are advocated to play important roles in maintaining gastric mucosal hydrophobicity. Further studies are necessary to elucidate the physiological roles of this unique substance in the stomach.

Adhesins, Bacterial↗
PubMed1993

Methods in laboratory investigation. Rapid and simple detection of c-Ki-ras2 gene codon 12 mutations by nonradioisotopic single-strand conformation polymorphism analysis.

BACKGROUND: To achieve simple and rapid detection of codon 12 mutations of the c-Ki-ras2 gene, we developed a nonradioisotopic single-strand conformation polymorphism analysis using silver stain. EXPERIMENTAL DESIGN: After a conventional polymerase chain reaction, amplified DNA fragments were mixed with formamide, heated and subjected to electrophoresis for 1.5 hours using minigels of polyacrylamide. The gels were then silver stained and single-strand DNA fragments were visualized directly. RESULTS: Electrophoresis and subsequent silver staining were completed within 2.5 hours. Plasmids carrying various codon 12 mutations of the c-Ki-ras2 gene were used as controls of Nonradioisotopic single-strand confirmation polymorphism analysis, and all six mutations were successfully separated from the normal allele in a single electrophoretic run. In the analysis of tumor cell lines and tumor samples, the results were identical with those of conventional dot blot hybridization using 32P-labeled oligonucleotide probes. Of 10 colorectal carcinoma tissues examined, 4 tumors were shown to carry codon 12 mutations of the c-Ki-ras2 gene. CONCLUSIONS: We conclude that this novel technique is a rapid, simple and useful method that may replace conventional methods.

Alleles↗
PubMed1992

K-sam gene encodes secreted as well as transmembrane receptor tyrosine kinase.

K-sam was first identified as a gene amplified in the stomach cancer cell line KATO-III. The size of the major transcript of the K-sam gene was 3.5 kilobases in KATO-III cells, and we have previously shown that K-sam encodes a receptor tyrosine kinase that belongs to the heparin-binding growth factor receptor, or fibroblast growth factor receptor, gene family. The K-sam gene expresses multiple sizes of mRNAs in brain tissue, the immature teratoma cell line NCC-IT, and KATO-III. RNA blot analyses with a variety of K-sam probes indicate that there are at least four classes of K-sam mRNAs. Three types of K-sam cDNAs in addition to the previously reported type of K-sam cDNA were isolated, and their nucleotide sequences encode a full-length transmembrane receptor, a secreted receptor with a tyrosine kinase domain, and a secreted receptor without a tyrosine kinase domain.

Base Sequence↗
PubMed1992

Gas phase derivatization of ammonia with 4-fluoro-7-nitrobenzo-2-oxa-1,3-diazole and its application to urease assay.

An ammonia-specific and rapid fluorometric method for determination of ammonia and urease activity was developed. The method is designed to assay ammonia levels or urease activity for the rapid diagnosis of Helicobacter pylori infection. 4-Fluoro-7-nitrobenzo-2-oxa-1,3-diazole was used to derivatize ammonia and 4-amino-7-nitrobenzo-2-oxa-1,3-diazole was analysed by high performance liquid chromatography at an excitation wavelength of 455 nm and an emission wavelength of 520 nm. Derivatization was designed to react with ammonia gas produced in a strong alkaline pH sample. The fluorescent intensity was linear in the range of 0.1-10 mM ammonia per tube when the reaction was carried out for 15 min at 37 degrees C. Urease activity, judged as the amount of ammonia production from urea, could be measured at 25 ng per tube (S/N = 1.5) with Jack bean meal urease. Because of its rapidity, this assay is potentially superior to the current standard method in use in clinical settings.

4-Chloro-7-nitrobenzofurazan↗
PubMed1992

Multiple strictures of the small intestine after long-term nonsteroidal anti-inflammatory drug therapy.

A 60-yr-old female patient with rheumatoid arthritis presented with nonsteroidal anti-inflammatory drug (NSAID)-induced ileal ulcers which caused intestinal bleeding and multiple strictures. Results of investigations, including radiological, pathological, and bacteriological examinations, were not consistent with Crohn's disease or intestinal tuberculosis. Rather, the lesion was characteristic of "diaphragm disease" caused by NSAIDs. Discontinuance of NSAIDs in combination with administration of ornoprostil (prostaglandin E1-derivative), sucralfate, and sulfasalazine put an end to the intestinal bleeding. This is a rate case of a patient with multiple strictures of the small intestine caused by NSAIDs.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1991

Identification of glycolipid receptors for Helicobacter pylori by TLC-immunostaining.

Helicobacter pylori has been identified as a causative agent in active chronic gastritis. The receptor for this bacteria, however, is not known. It is likely that the receptor molecules may be glycosphingolipids as shown in the cases of other bacteria. We explored this possibility by a thin-layer chromatography (TLC)-immunostaining method. Among glycosphingolipids extracted from human gastric mucosa, intact Helicobacter pylori specifically bound to I3SO3-GalCer and II3NeuAc-LacCer, whereas no specific binding to neutral glycosphingolipids, which share the same ceramide moiety with I3SO3-GalCer or II3NeuAc-LacCer, was demonstrated. Sonicated bacteria could still bind to II3NeuAc-LacCer with comparable affinity. In contrast, the binding of bacteria to I3SO3-GalCer was greatly diminished upon sonication. These results suggest that each of the oligosaccharide moieties of II3NeuAc-LacCer and I3SO3-GalCer may be specifically recognized by different ligand molecules of Helicobacter pylori.

Bacterial Adhesion↗
PubMed1991

Multiple diffuse hemangiomas of the large intestine.

A 54-year-old male case with multiple, diffuse hemangiomas of the large intestine is described. Large diffuse hemangiomas were located at the rectosigmoid and the ascending colon. Some polypoid lesions were located on the transverse colon. Tiny calcifications representing phleboliths were detected in those lesions. No skin hemangiomas were present. Although he did not manifest systemic bleeding tendency, blood examinations demonstrated the presence of mild consumption coagulopathy.

Colonic Polyps↗
PubMed1991

Short- and long-term effects of ammonium chloride on RNA, DNA and protein concentrations in muscle and serum in the rainbow trout, Oncorhynchus mykiss.

1. Effects of ammonium-induced acidosis on white muscle RNA, DNA and protein concentrations were examined in the rainbow trout, Oncorhynchus mykiss. Serum protein concentrations were also determined. 2. A single administration of ammonium chloride at a dose of sublethal level caused no changes in these parameters after 3 and 6 hr. 3. Multiple administrations at a lesser dose caused significant decreases in RNA and serum protein concentrations 48 and 72 hr after the first administration. 4. DNA and muscle protein concentrations remained unchanged throughout the experimental period. 5. Significant decreases in RNA-DNA ratios and RNA-muscle protein ratios were primarily attributed to decreases in RNA concentrations.

Ammonium Chloride↗
PubMed1991

[Development of sandwich radioimmunometric assay for serum c-erbB-2 oncogene product and its significance in diagnosing breast carcinoma].

A sandwich radioimmunometric assay using monoclonal antibodies 6G10 and SV2-61 gamma directed to the extracellular domain of the c-erbB-2 oncogene product was developed and the antigen levels in sera from normal donors and patients with breast carcinoma were determined. The antigen levels in normal donors were uniformly low (9.52 +/- 0.91 ng/ml) and 3.0% (2/66 cases) slightly exceeded the cutoff value (11.4 ng/ml). In patients with breast carcinoma, serum c-erbB-2 protein levels increased and the positivity was as high as 45.7% (16/35 cases) in recurrent cases. Determination of c-erbB-2 protein may be a useful marker for serological diagnosis of breast carcinoma.

Biomarkers, Tumor↗