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Biomedical subjects

N Ito

Publications and source records attributed to N Ito.

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

[Surgical management for an unruptured cerebral aneurysm accompanied by anti-phospholipid antibody syndrome: a case report].

Anti-phospholipid antibody syndrome(APS) is characterized by the presence of antibodies to phospholipids and various symptoms including those derived from thrombosis. APS has been shown to be frequently accompanied by multiple and recurrent cerebral ischemic lesions, suggesting that APS may play a critical role in developing cerebral ischemia of unknown etiology. Here, we present a case with an unruptured cerebral aneurysm accompanied by a severe stenosis of the middle cerebral artery as a manifestation of APS. The aneurysm was successfully treated surgically employing the following precaution to prevent potential damage on the fragile ischemic brain: preoperative administration of anticonvulsant, intermittent brain retraction, intraoperative SEP monitoring, and postoperative administration of anticoagulant. Our experience suggests that unruptured cerebral aneurysms accompanied by APS could be safely treated by strict paraoperative management.

Aged↗
PubMed2001

[Malignant lymphoma of the prostate: a case report].

A case of a primary malignant lymphoma of the prostate is presented. An 82-year-old man visited our hospital complaining of anal pain. Digital rectal examination revealed an enlarged prostate gland, which caused a rectal stricture. A computed tomographic scan and magnetic resonance imaging (MRI) showed a large mass arising from the prostate and protruding to the rectum. According to the Working Formulation, he was diagnosed with non-Hodgkin's lymphoma of B-cell origin, diffuse, mixed, small and large cell. The results of bone marrow puncture and imaging studies led to the diagnosis of primary malignant lymphoma of the prostate. Because of poor performance status deriving from severe anal pain, radiation therapy was performed to control the pain. After improvement of his performance status, he received combination chemotherapy consisting of cyclophosphamide, adriamycin, vincristine and predonisone (CHOP regimen). His prostate markedly diminished in size, but pneumonia developed. His respiratory condition rapidly deteriorated, and he died of respiratory failure about two and a half months after the onset of his illness. Malignant lymphoma involving the prostate, whether primary or secondary, is very rare. In our understanding, this case is thought to be the 28th clinical case of a malignant lymphoma of the prostate in Japan.

Aged↗
PubMed2000

Enhancing effects of Thai edible plants on 2-amino-3, 8-dimethylimidazo(4,5-f)quinoxaline-hepatocarcinogenesis in a rat medium-term bioassay.

Boesenbergia pandurata (Zingiberaceae), Languas galanga (Zingiberaceae) and Citrus hystrix (Rutaceae) are edible plants that are commonly used as flavors or condiments in various Thai food dishes. They are known to exert strong anti-promoting activity in a test of tumor promoter-induced Epstein-Barr virus (EBV) activation. In the present study their effects on hepatocarcinogenesis were investigated in a medium-term bioassay using F344 male rats. C. hystrix significantly enhanced 2-amino-3,8-dimethylimidazo(4, 5-f)quinoxaline-associated preneoplastic liver cell focus development while B. pandurata and L. galanga had borderline effects. The results suggest that C. hystrix as well as B. pandurata and L. galanga may contain agents augmenting the hepatocarcinogenicity of 2-amino-3,8-dimethylimidazo(4,5-f)quinoxaline.

Animals↗
PubMed2000

Molecular cloning and expression of a novel chondroitin 6-O-sulfotransferase.

A novel human chondroitin 6-O-sulfotransferase, designated C6ST-2, was identified by BLAST analysis of expressed sequence tag using the sequence of a previously described human chondroitin 6-O-sulfotransferase (C6ST-1) as a probe. The new cDNA sequence revealed an open reading frame coding for a protein of 486 amino acids with a type II transmembrane protein topology. The amino acid sequence displayed 24% identity to the human C6ST-1, and the highest sequence identity was found in the COOH-terminal catalytic domain. The expression of a soluble recombinant form of the protein in COS-1 cells produced an active sulfotransferase with marked specificity for polymer chondroitin. In contrast, keratan sulfate and oligosaccharides containing the Galbeta1-4GlcNAc sequence, which are good acceptor substrates for the C6ST-1, hardly served as acceptors. The identification of the reaction product indicated that the enzyme is a novel chondroitin 6-O-sulfotransferase (C6ST-2) that mainly transfers sulfate to N-acetylgalactosamine. The coding region of C6ST-2 was contained in a single exon and localized to chromosome Xp11. Northern blot analysis of human brain poly(A)(+) RNA revealed a single transcript of 2.4 kilobase pairs. Reverse transcription-polymerase chain reaction analysis showed that C6ST-2 is developmentally regulated in various tissues with expression persisting through adulthood in the spleen. Thus, we demonstrated the redundancy in chondroitin 6-O-sulfotransferases capable of forming chondroitin 6-sulfate, which is important for understanding the mechanisms leading to specific changes in the sulfation profile of chondroitin sulfate chains in various tissues during development and malignant transformation.

Adult↗
PubMed2000

Delay of DNA-adduct repair and severe toxicity in xeroderma pigmentosum group A gene (XPA) deficient mice treated with 2-amino-1-methyl-6-phenyl-imidazo [4,5-b] pyridine (PhIP).

Group-A xeroderma pigmentosum (XPA) gene-deficient mice are defective in nucleotide-excision repair and highly susceptible to ultraviolet-B-, and 9,10-dimethyl-1,2-benz[a]anthracene (DMBA)-induced skin carcinogenesis. In this study, changes of 2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine (PhIP)-DNA adduct formations in the liver, colon and lung, as assessed by the 32P-postlabeling method and immunohistochemical analysis, and carcinogenic and/or toxic susceptibility of both sexes of XPA-deficient mice (XPA-/-) to PhIP, which is a carcinogenic heterocyclic amine, was examined. Levels of PhIP-DNA adduct formations in the liver, colon and lung, were almost twice as high in XPA-/- as in wild type mice (XPA+/+) mice, 7 days after a single i.g. administration of PhIP, and their delay in recovery was observed in XPA-/- mice. For the long-term experiment, XPA-/- and XPA+/+ type mice were treated with 80 ppm PhIP in the diet for the first 4 weeks followed by 40 ppm after a 2-week recovery period (long-term experiment I), or 40 ppm PhIP throughout the experiment (long-term experiment II). Severe toxicity, as evidenced by body weight retardation and poor survival, was observed in the PhIP treated XPA-/- mice of both sexes, but not in the XPA+/+. At week 40 the experiments were terminated and histopathological examinations were performed after complete autopsy. Only lymphomas/leukemias were observed as neoplastic lesions, but no significant differences were observed between the groups. As non-neoplastic lesions, degenerating changes, for example in the pancreatic acinar cells, were observed with XPA-/- mice tending to be more sensitive than XPA+/+ mice. The present study demonstrated that PhIP-DNA adduct formations in the liver, colon and lung of XPA-/- mice were demonstrated and their recovery rate was more delayed than XPA+/+ mice, and furthermore, more severe toxicity to PhIP in XPA-deficient mice was observed, but they were not susceptible to PhIP carcinogenicity under the conditions of the experiment.

Animals↗
PubMed2000

Lack of frameshift mutations at coding mononucleotide repeats in hepatocellular carcinoma in Japanese patients.

BACKGROUND: Microsatellite instability occurs frequently in hereditary nonpolyposis colorectal carcinoma, in sporadic gastrointestinal carcinoma, and in other tumors. In these tumors, slippage-related frameshift mutations have been detected at coding mononucleotide repeats in genes such as those for transforming growth factor-beta receptor type II (TGFbetaRII), mannose 6-phosphate/insulinlike growth factor II receptor (M6P/IGFIIR), hMSH3, hMSH6, and Bcl-2-associated X protein (BAX). Because these genes regulate cell growth or repair DNA mismatches, loss of their function is thought to promote tumor development. The authors screened for these frameshift mutations and investigated the incidence of microsatellite instability (MI) in hepatocellular carcinoma (HCC) in Japan. METHODS: Fifty HCC samples were analyzed in this study. The authors used polymerase chain reactions to screen for frameshift mutation at the TGFbetaRII (A)(10) tract, the M6P/IGFIIR (G)(8) tract, the hMSH3 (A)(8) tract, the hMSH6 (C)(8) tract, and the BAX (G)(8) tract. For MI analysis, matched tumor and nontumor liver DNA were investigated with respect to 10 microsatellite loci. RESULTS: No frameshift mutation was detected in any case, and only 4% of these cancers exhibited MI in comparisons between tumor and nontumor liver specimens. CONCLUSIONS: This study suggests that frameshift mutation at coding mononucleotide repeats within TGFbetaRII, M6P/IGFIIR, hMSH3, hMSH6, and BAX genes did not seem to be involved in hepatocarcinogenesis in the Japanese population studied.

Adult↗
PubMed2000

Long-term changes of hydroxyapatite-coated dental implants.

There are many controversies about the long-term prognosis of hydroxyapatite (HA)-coated implants. Failure may be related to compositional and structural changes of the coating occurring during implantation. Two retrieved and two unused HA-coated blade-type implants were examined by stereomicroscopy, secondary electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and electron probe microanalysis. The objective was to investigate the HA morphology, composition, and structure, and to characterize the changes that occurred in the retrieved implant coatings. Retrieved implants presented partial loss of the coating, especially at the apical and mesiodistal edges. Remaining HA was thick and flattened in the cervical and central areas and gradually thinner and rougher towards the apical and mesiodistal edges. Increase of Cl and Mg, decrease of OH, and X-ray diffraction peak broadening were found in the retrieved implant coatings, in comparison with the unused implants. Morphological changes of the retrieved implants seem to depend on stress values in the surrounding bone and on implant mobility. Compositional changes and increased amount of lattice imperfections appeared in the retrieved implant coatings, as a result of ion substitutions in the apatite lattice. However, the present study could not confirm the influence of these changes on implant failure.

Coated Materials, Biocompatible↗
PubMed2000

Mediastinal growing teratoma syndrome.

A 27-year-old man had undergone orchiectomy and chemotherapy for testicular cancer. Despite normalization of raised tumor marker levels after postoperative chemotherapy, computed tomographic scanning demonstrated multiple swellings of the para-aortic lymph nodes with extension from beneath the aortic arch to the bifurcation of the descending aorta. Open biopsies of the para-aortic lymph nodes disclosed mature teraroma without malignant cells. The patient presented the typical features of mediastinal and retroperitoneal growing teratoma syndrome. A two stage resection of the tumors was performed via laparotomy and left thoracotomy. Histological examination of the resected specimens revealed a mature teratoma component without malignant cells. Upon follow-up sixteen months later, the patient was well and without recurrence.

Adult↗
PubMed2000

Tumor-detecting capacity and clinical usefulness of SPIO-MRI in patients with hepatocellular carcinoma.

The tumor-detecting capacity and clinical usefulness of superparamagnetic iron oxide (SPIO) magnetic resonance imaging (MRI) were examined in patients with hepatocellular carcinoma. The tumor detection rate of SPIO-MRI (64.5%) was comparable to those of dynamic computed tomography (CT) and plain MRI, but lower than that for Gd dynamic MRI (93.5%; P < 0.01%). A combination of Gd dynamic MRI and SPIO-MRI improved the detection rate; further, the tumor stage with respect to tumor blood-flow pattern was predicted by combining plain MRI with SPIO-MRI. This combination procedure may also be useful for selecting therapeutic strategies.

Aged↗
PubMed2000

Cell surface expression of immature H glycoprotein in measles virus-infected cells.

Two forms of hemagglutinin (H) protein, one with an apparent molecular mass of 78 kDa (78K H protein) and the other with that of 74 kDa (74K H protein), are present in cells infected with measles virus (MV). We previously observed that only the mature 78K H protein, a completely glycosylated form of the 74K H protein, was expressed on the cell surface of the infected cells. In the present study, we detected transient expression of the 74K H protein on the cell surface of infected cells by pulse-chase studies, although the level of this expression was much lower than that of the 78K H protein. On the cell surface the 74K H protein was present as dimers and sensitive to endo-beta-N-acetylglucosaminidase H digestion. Treatment with brefeldin A, which blocks the transport of membrane and secretory proteins from the endoplasmic reticulum to the Golgi apparatus, inhibited the cell surface expression of the 78K H protein, but not that of the 74K H protein. These data suggest that a part of the MV 74K H proteins could be transported directly to the cell surface - probably via an alternative pathway - without processing to the complex form in the Golgi apparatus.

Animals↗
PubMed2000

Early detection of carcinogenic substances and modifiers in rats.

Over the past 20 years, we have been developing in vivo medium-term bioassay systems in rats for detecting carcinogenic and modifying effects of test compounds. The systems are based on the two-step hypothesis of carcinogenesis. In a liver model, male F344 rats are initially given a single dose of diethylnitrosamine (DEN, 200 mg/kg, i.p.) and starting 2 weeks later are treated with test compounds for 6 weeks and then killed, all rats being subjected to two-thirds partial hepatectomy at week 3. Carcinogenic potential is scored by comparing the numbers and areas per cm(2) of induced glutathione S-transferase placental form (GST-P) positive foci in the livers of groups of about 15 rats with those of corresponding control groups given DEN alone. A positive response is defined as a significant increase in the quantitative values of GST-P-positive foci, such a negative response as no change or a decrease. The results obtained have been compared with reported Salmonella/microsome and long-term carcinogenicity test findings for the same compounds. Of the liver carcinogens, 30 out of 31 (97%) mutagenic and 29 out of 33 (88%) non-mutagenic compounds gave positive results. Carcinogens other than hepatocarcinogens gave a lower proportion of positive results (9 out of 42, 21%). This bioassay also provides information concerning inhibitory potential. The practical utility and benefits of a multi-organ medium-term experimental protocol for early detection of carcinogenic agents and modifiers acting at sites other than the liver are also discussed.

Animals↗
PubMed2000

Mitogenic activity of gelatin to murine spleen cells.

We reported previously that gelatin stimulates the growth of spleen cells in vitro. Tritium thymidine (3H-TdR) uptake into phytohemagglutinin (PHA)-stimulated spleen cells as well as intact spleen cells was augmented by gelatin. These findings suggest that gelatin serves as a mitogen for lymphoid cells. In this study, the target of action of gelatin was investigated. Tritium thymidine uptake into T cell-rich fraction was enhanced by incubation with 7.5 mg/ml of gelatin for 48 hours. The level of 3H-TdR uptake into B cell-rich fraction was not definitely increased by gelatin. Flow cytometric analysis confirmed these findings. Namely, it showed that treatment of spleen cells with 7.5 mg/ml gelatin increased a ratio of CD3-positive cells and decreased that of CD19-positive cells. Tritium thymidine uptake into natural killer cell-rich fraction was augmented by gelatin in a similar fashion to T cell-rich fraction. Tritium thymidine uptake into macrophages was very low and not affected by gelatin. Tritium thymidine uptake into macrophage-precursors was very low but was enhanced by gelatin. These findings suggest that gelatin could be used as an agent of cancer biotherapy.

Animals↗
PubMed2000

Mapping of epitopes and structural analysis of antigenic sites in the nucleoprotein of rabies virus.

Linear epitopes on the rabies virus nucleoprotein (N) recognized by six MAbs raised against antigenic sites I (MAbs 6-4, 12-2 and 13-27) and IV (MAbs 6-9, 7-12 and 8-1) were investigated. Based on our previous studies on sites I and IV, 24 consecutively overlapping octapeptides and N- and C-terminal-deleted mutant N proteins were prepared. Results showed that all three site I epitopes studied and two site IV epitopes (for MAbs 8-1 and 6-9) mapped to aa 358-367, and that the other site IV epitope of MAb 7-12 mapped to aa 375-383. Tests using chimeric and truncated proteins showed that MAb 8-1 also requires the N-terminal sequence of the N protein to recognize its binding region more efficiently. Immunofluorescence studies demonstrated that all three site I-specific MAbs and one site IV-specific MAb (7-12) stained the N antigen that was diffusely distributed in the whole cytoplasm; the other two site IV-specific MAbs (6-9 and 8-1) detected only the N antigen in the cytoplasmic inclusion bodies (CIB). An antigenic site II-specific MAb (6-17) also detected CIB-associated N antigen alone. Furthermore, the level of diffuse N antigens decreased after treatment of infected cells with cycloheximide. These results suggest that epitopes at site I are expressed on the immature form of the N protein, but epitope structures of site IV MAbs 6-9 and 8-1 are created and/or exposed only after maturation of the N protein.

Amino Acid Sequence↗
PubMed2000

[A comparative study on the clinical utility of cefozopran and cefpirome against complicated urinary tract infections].

Aiming at evaluating the utility of cefozopran (CZOP) against complicated urinary tract infections with the velocity of eradication of causal bacteria in early treatment and clinical efficacy by new criteria of UTIs, a comparative study was conducted using cefpirome (CPR) as the control drug. CZOP and CPR were administered by intravenous drip infusion at a dose of 1 g twice daily. The duration of treatment was for 5 days. The study method involved randomized assignment of the subjects to either group CZOP or group CPR. The results were as follows: 1. Of a total of 80 cases treated, 65 (CZOP group--32 cases, CPR group--33 cases) were evaluated for efficacy. 2. The overall clinical efficacy evaluation according to the criteria proposed by Japanese UTI Committee rated the CZOP group as 90.6% (29/32), and the CPR group as 90.9% (30/33), with no significant difference between the 2 groups. Clinical efficacy evaluated by attending physicians rated the CZOP group as 93.8% (30/32) and the CPR group as 90.9% (30/33). There was no significant difference between the 2 groups. 3. The efficacy rates to pyuria on day 2 were 26.7% and 0% for the CZOP group and the CPR group, respectively, indicating a higher efficacy rate for the former (p < 0.05). Those on after treatment were 59.4% and 54.5% for the CZOP group and the CPR group, respectively, with no significant difference between the 2 groups. 4. Regarding the bacteriological effect, the eradication rates of both groups were over 90% on day 1 and after treatment. There was no significant difference between the 2 groups. 5. Side effects occurred in 1 case (2.6%) out of 39 in the CZOP group and in 1 case (2.4%) out of 41 in the CPR group. Laboratory test value fluctuation was noted in 8 (20.5%) of 39 cases in the CZOP group and 11 (26.8%) of 41 cases in the CPR group. There was no significant difference between the 2 groups. The results indicate that CZOP achieves an early efficacy to pyuria, and is as useful as CPR against complicated urinary tract infections.

Adult↗