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Biomedical subjects

Y Ozeki

Publications and source records attributed to Y Ozeki.

At least 109 records · Page 6Linked to original sources
PubMed1995

Effects of nitrofurazone on spermatogenesis and reproductive toxicity in male rats--part of a collaborative work to determine optimal administration period and endpoints.

To determine an appropriate administration period and sensitive end-points for the evaluation of effects on male fertility, male Sprague-Dawley rats were orally given nitrofurazone, a model compound, at doses of 12.5, 25, or 50 mg/kg/day for 4 weeks, or at doses of 12.5 or 25 mg/kg/day for 9 weeks before mating with untreated females. Copulation and fertility indices were decreased, and pregnancy did not result at doses of 25 mg/kg/day and over with both dosing periods. An increase in preimplantation loss, and decreases in implants and live fetuses were observed with 12.5 mg/kg/day after 9-weeks dosing. However, no reproductive endpoints were affected by the same dose level for 4-weeks. Sperm head count was reduced at doses of 25 mg/kg/day and over with both dosing periods. Histopathology revealed tubular degeneration and interstitial cell hyperplasia at doses of 25 mg/kg/day and over after both periods of dosing. Moreover, failure of spermiation in tubular epithelia was also detected in the 12.5 mg/kg groups. These results suggest that 4-weeks premating exposure is sufficient for evaluation of the effects of nitrofurazone on mate fertility, and the most sensitive endpoint in this 4-week premating-dose study is a histopathological change.

Animals↗
PubMed1994

C-type galactoside-binding lectin from Bothrops jararaca venom: comparison of its structure and function with those of botrocetin.

A Ca(2+)-dependent type (C-type) galactoside-binding lectin was purified from venom of the snake Bothrops jararaca by thiodigalactoside-Sepharose affinity column chromatography. B. jararaca lectin is a disulfide-linked homodimer composed of 14-kDa subunits. The N-terminal 55-residue amino acid sequence was determined and appeared to belong to the animal C-type lectin family. This 55-residue sequence showed 37% identity with botrocetin, an exogenous von Willebrand factor modulator purified from the same venom, and 85% identity with a lectin from rattlesnake (Crotalus atrox) venom. B. jararaca lectin showed Ca(2+)-dependent hemagglutination activity but did not induce platelet aggregation in the presence or absence of Ca2+ and von Willebrand factor and did not inhibit platelet aggregation induced by botrocetin and von Willebrand factor. On the other hand, botrocetin, which also contains a C-type lectin motif in the N-terminal sequence, did not show hemagglutinating activity toward rabbit and human erythrocytes, nor binding activity toward immobilized glycoproteins. These results indicate that at least two structurally similar but functionally distinct proteins, both belonging to the C-type lectin family, are present in the venom of B. jararaca.

Amino Acid Sequence↗
PubMed1994

Abdominal wall desmoid mimicking intra-abdominal mass: MR features.

A case of abdominal wall desmoid which enlarged toward the liver and mimicked an intra-abdominal tumor is presented. T*2-weighted MR images clearly demonstrated the tumor's continuity with the rectus abdominis muscle. The case presented suggests MRI may provide more valuable information concerning the origin of a right-upper-quadrant mass than CT does. However, the nature of the signals and attachment which this case showed were so unusual for desmoids that this case has not been diagnosed accurately.

Abdominal Muscles↗
PubMed1994

Transcription of the faoAB operon which encodes the HDT multienzyme complex involved in fatty acid beta-oxidation in Pseudomonas fragi B-0771.

Transcription of the two clustered genes, faoA and faoB, for the multienzyme complex for fatty acid beta-oxidation (HDT) from the Gram-negative bacterium, Pseudomonas fragi, was investigated. Northern blot hybridization and primer extension analysis indicated that these genes comprised an operon, giving a 3.6 kb mRNA. Transcription of the 3.6 kb faoAB mRNA was induced by palmitic acid. Using the lacZ gene as a reporter gene for a promoter activity search, the essential region for induction of the faoAB gene transcription by palmitic acid was mapped at the 331 bp region just upstream of the transcription initiation site. Deletion of the 136 bp SalI-NheI fragment just downstream of the transcription initiation site caused the constitutive expression of the faoA-lacZ fusion protein in P. fragi, suggesting that there is a regulatory element interacting with the transcription repressor.

Base Sequence↗
PubMed1994

Purification and characterization of two Ca(2+)-dependent lectins from coelomic plasma of sea cucumber, Stichopus japonicus.

Two structurally distinct lectins were purified from the coelomic plasma of holothurian, Stichopus japonicus, by affinity chromatography on a porcine stomach mucin-conjugated agarose column, gel filtration on a Superose 6 column, and ion-exchange chromatography on a HiTrap Q-FPLC. The two lectins showed apparent molecular masses of about 400 kDa (SPL-1) and 60 kDa (SPL-2) on gel filtration, but about 17 kDa on SDS-PAGE under reducing conditions. Both lectins showed hemagglutination activity toward rabbit erythrocytes in the presence of Ca2+ ions. The N-terminal amino acid sequences were highly homologous to but distinct from those of a Ca(2+)-dependent (C-type) lectin named SJL-I purified from the same species. In addition to porcine stomach mucin, the hemagglutination activity of SPL-1 was strongly inhibited by uronic acids such as galacturonic acid, and glucuronic acid, while the activity of SPL-2 was inhibited by GalNAc and galactosides. Both lectins were adsorbed on clotted coelomocytes in the presence of Ca2+ but not in the presence of inhibitory sugars or EGTA, suggesting the presence of an endogenous carbohydrate ligand(s) for plasma C-type lectins in the clot. However, coelomocyte clotting occurred normally even in the presence of inhibitory sugars, but was strongly inhibited by synthetic GRGDSP peptide or EGTA, suggesting the participation of integrin but not the lectin-carbohydrate interaction in the clotting events.

Animals↗
PubMed1994

Expression of the multidrug resistance gene (MDR1) in non-small cell lung cancer.

To ezamine the clinical relevance of P-glycoprotein, encoded by the human multidrug resistance gene (MDR1), to multidrug resistance in lung cancer, we examined the expression of MDR1 in 107 non-small cell lung cancer (NSCLC) specimens and 20 corresponding specimens of normal lung tissues. We also evaluated the relationship between MDR1 expression and the histopathology and pathological staging of NSCLC. The tumors consisted of 60 adenocarcinomas, 38 squamous cell carcinomas, 8 large cell carcinomas, and 1 adenosquamous carcinoma. MDR1 expression was semi-quantified by use of the reverse transcriptase-polymerase chain reaction method. We subclassified the NSCLC into 3 grades according to the MDR1 expression level (-, +, ++). Sixty-one of the 107 tumor specimens (57%) and 18 of the normal lung tissue specimens (90%) expressed various levels of the MDR1 gene. Only one tumor specimen showed higher MDR1 expression than the corresponding normal lung tissue. The relationship between pathological stage and MDR1 expression levels was not significant. These results suggest that the level of MDR1 expression in lung cells is decreased as cells progress from the normal to the transformed state.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1994

Immunohistochemical analysis of nm23/NDP kinase expression in human lung adenocarcinoma: association with tumor progression in Clara cell type.

Levels of nm23-H1/nucleoside diphosphate kinase (NDP kinase) expression have been reported to correlate inversely with metastatic potential in some tumors but not in others. Whether or not nm23 gene product is associated with metastatic potential in lung cancer is not clear as yet. We therefore immunohistochemically examined the expression of nm23 gene products in primary lung adenocarcinomas according to cytologic subtypes in order to clarify the association of its expression with the clinical features of the disease. Seventy-two (64.9%) of the 111 lung adenocarcinomas were positive for nm23 protein. In lung adenocarcinoma of Clara cell type, high levels of nm23 expression were associated with advanced pathologic stage, positive lymph node status, and poorer prognosis (P < 0.05). However, no correlation with clinical outcome was observed in other cell types. Our data suggest that higher levels of nm23 expression are associated with tumor progression in lung adenocarcinoma of Clara cell type.

Adenocarcinoma↗
PubMed1993

Expression of carbohydrate antigens in human pulmonary adenocarcinoma.

BACKGROUND: The altered and anomalous expression of carbohydrate antigens (CA) occur in patients with lung carcinomas. METHODS: To investigate the relationship between prognosis and immunohistochemical findings of CA in serum and pulmonary adenocarcinomas (PA), PA specimens surgically resected from 102 patients were studied with the use of A, B, H, Lewis(Le)a, Le(b), Le(x), Le(y), sialyl Le(a) (FH-7), sialyl Le(x-i) (SLX) (FH-6), sialosyl Tn (TKH-2), and CA 19-9. The Lewis blood group types were determined by the dot blotting method on patients' serum using monoclonal anti-Le(a), Le(b), Le(x), and Le(y). Formalin-fixed paraffin-embedded PA sections were stained using the avidin-biotin-peroxidase complex methods. RESULTS: There was no correlation between the patients' postoperative survival and tissue expression of CA, although survival correlated with the clinical stages, histologic differentiation of PA, and serum SLX in Stage 4. The higher the positive rate of both Le(b) and Le(y), the better their differentiation in PA specimens. Regardless of blood group type, PA showed high positive reactions for FH-6 (88%) and Le(y) (87%). The serum concentration of CA 19-9 correlated with immunohistochemical reactions of tumors (Spearman correlation coefficient = 0.33, P = 0.02). The expression of Le(a) in Lewis (a-b+) phenotype patients and Type 2 CA, such as Le(y) and FH-6, is characteristic in PA. CONCLUSIONS: The findings suggest that CA tissue expression may not reflect postoperative survival length of patients with PA, but biological aberrant fucosylation or sialylation as well as morphologic alteration may occur in neoplastic cells.

ABO Blood-Group System↗
PubMed1993

Primary structure of two-chain botrocetin, a von Willebrand factor modulator purified from the venom of Bothrops jararaca.

The complete amino acid sequence and location of the disulfide bonds of two-chain botrocetin, which promotes platelet agglutination in the presence of von Willebrand factor, from venom of the snake Bothrops jararaca are presented. Sequences of the alpha and beta subunits were determined by analysis of peptides generated by digestion of the S-pyridylethylated protein with Achromobacter protease I or alpha-chymotrypsin and by chemical cleavage with cyanogen bromide or 2-(2'-nitrophenylsulfenyl)-3-methyl-3-bromoindolenine. Two-chain botrocetin is a heterodimer composed of the alpha subunit (consisting of 133 amino acid residues) and the beta subunit (consisting of 125 amino acid residues) held together by a disulfide bond. Seven disulfide bonds link half-cystine residues 2 to 13, 30 to 128, and 103 to 120 of the alpha subunit; 2 to 13, 30 to 121, and 98 to 113 of the beta subunit; and 80 of the alpha subunit to 75 of the beta subunit. In terms of amino acid sequence and disulfide bond location, two-chain botrocetin is homologous to echinoidin (a sea urchin lectin) and other C-type (Ca(2+)-dependent) lectins.

Amino Acid Sequence↗
PubMed1993

Comparative studies of asparagine-linked sugar chains of immunoglobulin G from eleven mammalian species.

1. Asparagine-linked sugar chains released by hydrazinolysis from IgGs of porcine, equine, bovine, goat, ovine, canine, rabbit, guinea-pig and rat were comparatively analyzed by microsequencing and lectin affinity chromatography. 2. Sugar chains of all IgGs basically consisted of biantennary complex-type oligosaccharides containing 0-2 sialic acid residue(s). More than 70% of the oligosaccharides were neutral, except for guinea-pig IgG, and fucosylated trimannosyl core structures were dominant except for rabbit IgG. Bisecting N-acetylglucosamine residue was absent in porcine and equine IgGs. 3. A large quantity of galactose-less oligosaccharides were present in IgGs of porcine, equine, canine and rat.

Animals↗
PubMed1993

Immunohistochemical analysis of cathepsin B expression in human lung adenocarcinoma: the role in cancer progression.

Production of cathepsin B by tumor cells has been linked to metastatic potential in several experimental models. Sections of 95 primary lung adenocarcinomas were examined for expression of cathepsin B using a standard avidin-biotin immunohistochemical technique. Staining for cathepsin B was observed in 22.1% of all cases and 28.0% of those of the Clara cell type. In Clara cell adenocarcinomas, cathepsin B expression correlated with positive lymph node status, presence of distant metastases, and poor prognosis (P < 0.05). However, no correlation with clinical outcome was observed in other cell types. Our data suggest that cathepsin B may be involved in invasion and metastasis in Clara cell lung adenocarcinoma.

Adenocarcinoma↗
PubMed1993

[Inflammatory tumor of the hepatic hilus mimicking bile duct cancer--report of a case].

A 73-year-old man was admitted to our hospital because of jaundice. Ultrasonography and computed tomography showed a tumor of the hepatic hilus causing obstructive jaundice. Angiography revealed a stenosis of the right hepatic artery. Under the diagnosis of carcinoma of the hepatic hilus, extended right hepatectomy with resection of the caudate lobe was performed. A tumor showing expophytic growth, 2.1 x 1.9 x 1.5cm in size, was seen in the hepatic hilus. Histologically, the tumor was proved to be a non-neoplastic fibrous tissue simulating the inflammatory pseudotumor.

Aged↗
PubMed1993

[A case of chest wall abscess due to Salmonella newport].

A 18-year-old female with a history of precordial pain was admitted. There was a mass (3.5 x 2.5 cm) in the right inframammary region which was suspected to be chest wall tumor on the basis of CT scan and Ga scintigraphy findings. Exploratory surgery, consisting of total resection of the tumor without removing the ribs, was performed and revealed an abscess. Culture of pus from the abscess grew Salmonella newport (0 antigen 8, H antigen eh; 1.2). Focal infection with Salmonellosis is discussed. Surgical treatment is necessary in addition to chemotherapy.

Abscess↗
PubMed1993

[Two cases of intrapulmonary teratoma].

We encountered two unusual cases of intrapulmonary teratoma, one in a 31-year-old female and the other in a 15-year-old female. The chief complaint of both patients was fever, and in both a consolidation was detected in the left upper lobe using routine radiography. We performed left upper lobectomy for the former patient and segmentectomy of the left lingual segment for the latter. Neither tumor communicated with the mediastinum. Histological examination revealed a pulmonary teratoma containing no thymic tissue in both. Intrapulmonary teratoma has been reported to be extremely rare, and only 27 cases including these two have been reported in the literature.

Adolescent↗