Biomedical subjects

H Ota

Publications and source records attributed to H Ota.

At least 19 recordsLinked to original sources

PubMed2006

Co-localization of TFF2 with gland mucous cell mucin in gastric mucous cells and in extracellular mucous gel adherent to normal and damaged gastric mucosa.

Trefoil factor 2 (TFF2) is mucin associated peptide that has a mucosal barrier function in addition to participating in repair and healing. We examined the localization of TFF2 and gastric mucins in gastric mucous cells, the surface mucous gel layer (SMGL) adherent to normal gastric mucosa, and in the mucoid cap covering gastric erosions. Carnoy's solution, or formalin/picric acid-fixed paraffin embedded materials from resected stomachs and formalin-fixed paraffin embedded gastric biopsy materials were used. Sections were immunostained for the TFF2 and histochemically stained for gastric mucins. In addition, thick sectioned gastric mucosa fixed in Carnoy's solution were stained with FITC-labeled GSA-II lectin specific for gland mucous cell mucin and examined for three-dimensional images of the SMGL using a confocal laser scanning microscope. The TFF2 and gland mucous cell mucin were found intermixed together in the gastric gland mucous cells, in the SMGL in laminated layers, and in the mucoid cap. A laminated arrangement of continuous sheets of gland mucous cell mucin in the SMGL was demonstrated in the three-dimensional images. Co-localization of the TFF2 with gland mucous cell mucin suggests a physical interaction between the TFF2 and gland mucous cell mucin. The TFF2 trapped in the adherent mucins may be responsible for mucosal defense, healing, and repair.

Biopsy↗

PubMed2006

BRAF mutations and phosphorylation status of mitogen-activated protein kinases in the development of flat and depressed-type colorectal neoplasias.

Although some molecular differences between flat-depressed neoplasias (FDNs) and protruding neoplasias (PNs) have been reported, it is uncertain if the BRAF mutations or the status of phosphorylated mitogen-activated protein kinase (p-MAPK) are different between theses two groups. We evaluated the incidence of BRAF and KRAS mutations, high-frequency microsatellite instability (MSI-H), and the immunohistochemical status of p-MAPK in the nonserrated neoplasias (46 FDNs and 57 PNs). BRAF mutations were detected in four FDNs (9%) and none of PNs (P=0.0369 by Fisher's exact test). KRAS mutations were observed in none of FDNs and in 14 PNs (25%; P=0.0002 by Fisher's exact test). MSI-H was detected in seven out of 44 FDNs (16%) and in one out of 52 of PNs (2%) (P=0.022 by Fisher's exact test). Type B and C immunostaining for p-MAPK was observed in 34 out of 46 FDNs (72%), compared with 24 out of 55 PNs (44%; P=0.0022 by chi(2) test). There was no significant difference in the type B and C immunostaining of p-MAPK between FDNs with and without BRAF mutations. BRAF and KRAS mutations are mutually exclusive in the morphological characteristics of colorectal nonserrated neoplasia. Abnormal accumulation of p-MAPK protein is more likely to be implicated in the tumorigenesis of FDNs than of PNs. However, this abnormality in FDNs might occur via the genetic alteration other than BRAF or KRAS mutation.

Adenocarcinoma↗

PubMed2006

Sirt1 inhibitor, Sirtinol, induces senescence-like growth arrest with attenuated Ras-MAPK signaling in human cancer cells.

The induction of senescence-like growth arrest has emerged as a putative contributor to the anticancer effects of chemotherapeutic agents. Clinical trials are underway to evaluate the efficacy of inhibitors for class I and II histone deacetylases to treat malignancies. However, a potential antiproliferative effect of inhibitor for Sirt1, which is an NAD(+)-dependent deacetylase and belongs to class III histone deacetylases, has not yet been explored. Here, we show that Sirt1 inhibitor, Sirtinol, induced senescence-like growth arrest characterized by induction of senescence-associated beta-galactosidase activity and increased expression of plasminogen activator inhibitor 1 in human breast cancer MCF-7 cells and lung cancer H1299 cells. Sirtinol-induced senescence-like growth arrest was accompanied by impaired activation of mitogen-activated protein kinase (MAPK) pathways, namely, extracellular-regulated protein kinase, c-jun N-terminal kinase and p38 MAPK, in response to epidermal growth factor (EGF) and insulin-like growth factor-I (IGF-I). Active Ras was reduced in Sirtinol-treated senescent cells compared with untreated cells. However, tyrosine phosphorylation of the receptors for EGF and IGF-I and Akt/PKB activation were unaltered by Sirtinol treatment. These results suggest that inhibitors for Sirt1 may have anticancer potential, and that impaired activation of Ras-MAPK pathway might take part in a senescence-like growth arrest program induced by Sirtinol.

Benzamides↗

PubMed2006

The relationships of proteinuria, serum creatinine, glomerular filtration rate with cardiovascular disease mortality in Japanese general population.

Proteinuria, high serum creatinine, and reduced glomerular filtration rate (GFR) have been associated with increased mortality from cardiovascular disease (CVD) and all causes. However, the combined effect of proteinuria with serum creatinine and GFR on CVD or all-cause mortality has not been well investigated. We conducted a 10-year prospective cohort study of 30,764 men and 60,668 women aged 40-79 years who participated in annual health checkups in 1993. The Cox proportional hazards model was used to estimate the relative risk (RR) after adjusting for age, smoking, and other cardiovascular risk factors. The multivariable RR (95% confidence interval (CI)) of CVD death for positive vs negative proteinuria was 1.38 (1.05-1.79) among men and 2.15 (1.64-2.81) among women. The respective RR for the highest vs lowest creatinine groups (> or = 1.3 vs < or = 0.8 mg/dl for men and > or = 1.1 vs < or = 0.6 mg/dl for women) was 1.56 (1.19-2.04) among men and 2.15 (1.58-2.93) among women. The respective RR for GFR < 60 vs > r = 100 ml/min/1.73 m2 was 1.65 (1.25-2.18) among men and 1.81 (1.39-2.36) among women. For individuals with proteinuria combined by hypercreatininemia or reduced GFR, the risk of CVD death was two-fold higher in men and 4-6-fold higher in women compared to those without proteinuria and with normal creatinine level or GFR. Similar associations were observed for stroke, coronary heart disease, and all-cause mortality. Proteinuria, and hypercreatininemia or reduced GFR and their combination were significant predictors of CVD and all-cause mortality.

Antihypertensive Agents↗

PubMed2005

Treatment of hepatocellular carcinoma with major portal vein thrombosis by combined therapy with subcutaneous interferon-alpha and intra-arterial 5-fluorouracil; role of type 1 interferon receptor expression.

We previously reported the beneficial effects of combination therapy of interferon (IFN)-alpha/5-fluorouracil (FU) for advanced hepatocellular carcinoma (HCC) with tumour thrombi in the major portal branches. This report describes the results of longer follow-up and includes more than double the number of patients relative to the original report, and evaluates the role of IFN-alpha/type 2 interferon receptor (IFNAR2) expression on the response to the combination therapy. The study subjects were 55 patients with advanced HCC and tumour thrombi in the major branches of the portal vein (Vp3 or 4). They were treated with at least two courses of IFN-alpha/5-FU without major complication. In the 55 patients, 24 (43.6%) showed objective response (eight (14.5%) showed complete response, 16 (29.1%) partial response), four (7.3%) showed no response, and 27 (49.1%) showed progressive disease. Immunohistochemically, IFNAR2 expression was detected in nine out of 13 (69.2%) patients. There was significant difference in the time-to-progression survival (P = 0.0002) and the overall survival (P < 0.0001) between IFNAR2-positive and -negative cases. There was a significant correlation between IFNAR2 expression and response to IFN-alpha/5-FU combination therapy in univariate analysis (P = 0.0070). IFN-alpha/5-FU combination therapy is a promising modality for advanced HCC with tumour thrombi in the major portal branches and could significantly depend on IFNAR2 expression.

Adult↗

PubMed2005

Synthetic biodegradable polymers as drug delivery systems for bone morphogenetic proteins.

Bone morphogenetic proteins (BMP) induce bone formation in vivo, and clinical application in repair of bone fractures and defects is expected. However, appropriate systems to deliver BMP for clinical use need to be developed. We synthesized a new synthetic biodegradable polymer, poly-D,L-lactic acid-para-dioxanone-polyethylene glycol block copolymer (PLA-DX-PEG), to serve as a biocompatible, biodegradable polymer for recombinant human (rh) BMP-2 delivery systems. In animal experiments, new bone was efficiently formed and a large bone defect was repaired using PLA-DX-PEG/rhBMP-2 composites. In addition, this new polymer could be used as an injectable delivery system for rhBMP-2. The rhBMP-2/PLA-DX-PEG composites also could be combined with other materials such as hydroxyapatite or titanium. This new synthetic polymer might be used for rhBMP-2 delivery in various clinical situations involving repair of bone, leading to great changes in orthopedic treatment.

Animals↗

PubMed2005

Roles of virD4 and cagG genes in the cag pathogenicity island of Helicobacter pylori using a Mongolian gerbil model.

BACKGROUND AND AIMS: The roles of the virD4 and the cagG genes in the cag pathogenicity island of Helicobacter pylori for gastroduodenal pathogenesis are unclear and their roles in vivo have not been examined. METHODS: Seven week old male Mongolian gerbils were inoculated with the wild type H pylori TN2GF4, its isogenic virD4, or cagG mutants. Animals were sacrificed at 4, 12, and 24 weeks after inoculation. Gastric inflammation and H pylori density were evaluated by histology, inflammatory response (as measured by interleukin (IL)-1beta mRNA levels), proliferative activity (as assessed by 5'-bromo-2'deoxyuridine labelling indices), and host systemic reaction (as measured by anti-H pylori IgG antibody). RESULTS: Degree of gastric inflammation, proliferative activity, and mucosal IL-1beta mRNA levels remained low throughout the first 12 weeks in gerbils infected with the virD4 mutants. Degree of gastric inflammation and proliferative activity increased at 24 weeks with the virD4 mutants reaching levels comparative with those seen at four weeks with the wild-type strains. Mucosal IL-1beta mRNA levels were also increased at 24 weeks with the virD4 mutants and levels at 24 weeks were similar between the wild-type and virD4 mutants. In contrast, gerbils infected with the cagG mutants had reduced ability to colonise gerbils, and no or little gastric inflammation or proliferative activity was observed. CONCLUSIONS: Loss of the virD4 gene temporally retarded but did not abrogate gastric inflammation. Loss of the cagG gene abolished gastric inflammation partially via reduced ability to colonise gerbils. Unknown factors related to the type IV secretion system other than CagA may influence gastric inflammation.

Animals↗

PubMed2004

Does action make the link between number and space representation? Visuo-manual adaptation improves number bisection in unilateral neglect.

If the visual world is artificially shifted by only 10 degrees, people initially experience difficulty in directing their actions toward visual goals, but then rapidly compensate the visual distortion. The consequence of such adaptation can be measured as visual and proprioceptive aftereffects, as well as by performance on pointing tasks without visual feedback. Recent work has shown that more cognitive deficits can be improved following prism adaptation in patients with unilateral neglect. Here we show that a short visuo-manual adaptation to prisms improves performance on a mental number-bisection task recently shown to be impaired in unilateral neglect. The association previously found between space and number representation (the mental number line) may thus be grounded in common action principles. Our results suggest that visuo-motor plasticity functionally links parietal areas involved in space and number representation.

Brain Ischemia↗

PubMed2003

No major tumorigenic role for beta-catenin in serrated as opposed to conventional colorectal adenomas.

Intracellular redistribution of beta-catenin through mutation of the adenomatous polyposis coli (APC) gene has been proposed as an early tumorigenic event in most colorectal tumours. In serrated adenoma (SA), a newly recognised subtype of colorectal adenoma, APC mutations are uncommon, and the contribution of beta-catenin to tumorigenesis remains unclear. We compared intracellular localisation of beta-catenin and presence of mutations in exon 3 of beta-catenin between 45 SAs, with 71 conventional adenomas (CADs), and eight carcinomas invading the submucosa (SCAs). Widespread or focal nuclear beta-catenin expression was demonstrated in 7% of SAs (three out of 45), 61% of CADs (43 out of 71), and 88% of SCAs (seven out of eight). Cytoplasmic immunostaining for beta-catenin was demonstrated in 16% of SAs (seven out of 45), 77% of CADs (55 out of 71), and 88% of SCAs (seven out of eight). No mutation in exon 3 of beta-catenin was found in SAs or SCAs, while 7% of CADs (five out of 71) had beta-catenin mutations. No nuclear or cytoplasmic expression of beta-catenin was observed in the hyperplastic or conventionally adenomatous epithelium of mixed-type SAs. These findings suggest that beta-catenin mutation is unlikely to contribute to the tumorigenesis in SA, and that intracellular localisation of beta-catenin may not be associated with an early event of the tumour progression in most SAs.

Adenoma↗

PubMed2003

Different spatial processing for stimulus-centered and body-centered representations.

The authors describe a patient who experienced two successive strokes in the right hemisphere. After the first stroke, she showed stimulus-centered left neglect confined to right space on a circle discrimination task, which resolved. After the second stroke, she showed body-centered left neglect on the same task. These observations of two types of left neglect in the same patient suggest there are at least two distinct spatial attentional systems in the brain: global and focal attentional systems.

Aged↗

PubMed2003

Local bone formation by injection of recombinant human bone morphogenetic protein-2 contained in polymer carriers.

The regenerating potential of human bone is limited. The repair of large bone defects often associated with bone tumor resections is not observed, and nonunion or delayed union of bone is a serious problem for fracture treatment. In these cases, autogeneic or allogeneic bone grafting has been routinely indicated, but these approaches require invasive surgical procedures. An alternative approach described in this paper involves the injection of bone morphogenetic proteins (BMPs) in a polymeric delivery system. We demonstrate that synthetic biodegradable polymers, poly-D,L-lactic acid-polyethylene glycol (PLA-PEG) block copolymers, which exhibit an exquisite temperature-dependent liquid-semisolid transition, work well as an injectable delivery system for recombinant human (rh) BMP-2. The thermosensitive property of the PLA-PEG/rhBMP-2 composite is permissive to percutaneous injection when heated. The fluidity of this composite decreases as it cools down to body temperature and the resultant semisolid form provides a scaffold for bone formation through the gradual local release of the rhBMP-2. This new type of injectable osteoinductive material will enable a less invasive approach to surgeries involving the restoration or repair of bone tissues.

Animals↗

PubMed2003

Contrasting patterns of genetic variation in the two sympatric geckos Gekko tawaensis and G. japonicus (Reptilia: Squamata) from western Japan, as revealed by allozyme analyses.

Allozyme variation in two congeneric sympatric geckos, Gekko tawaensis and G. japonicus, from western Japan was examined. These species show similar densities and spatial arrangements of populations in this region, and their genetic structures are thus expected to have been formed under the influences of comparable geohistorical, environmental, and demographic factors. Results of the analyses, however, revealed strikingly different genetic patterns in the two species. Populations of G. tawaensis invariably showed a remarkably lowered heterozygosity (0-0.017) compared to G. japonicus (0.089-0.124). On the other hand, the genetic heterogeneity among populations is much greater in G. tawaensis (F(ST)=0.726) than in G. japonicus (F(ST)=0.101). The Mantel test failed to detect any significant correlations between log (estimated migration rate) and log (geographic distance) in either species, or between matrices of interpopulation pairwise F(ST) for the two species. These results suggest that, in each species, formation of the current genetic structure in western Japan has been chiefly influenced by stochastic factors, rather than the geohistorical architecture of this region. The high F(ST) and low heterozygosity in G. tawaensis suggest the effects of severe local fragmentation. On the other hand, the relatively low F(ST) and high heterozygosity in G. japonicus imply extensive gene flow among populations. Absence of significant correlations between the estimated migration rate and geographic distance in G. japonicus may suggest that such gene flow is promoted by human-mediated transport of this primarily house-dwelling lizard.

Animals↗

PubMed2003

Proliferation of type II pneumocytes in the lung biopsy specimens reflecting alveolar damage.

Proliferation of type II pneumocytes may be the most sensitive pathological indicator of alveolitis, and the density of type II pneumocytes reflecting the severity of the recent alveolar damage. Twenty-nine patients were divided into three groups by the severity of ground-glass opacities on the CT scans; the severe (acute), the moderate (subacute) and the mild (chronic) groups. We compared the density of type II pneumocytes in the transbronchial lung biopsy specimens and cell analysis of bronchoalveolar lavage (BAL) fluid with the ground-glass opacities. Clinical and laboratory findings and BAL fluid analysis also corresponded well with this grouping. Type II pneumocytes were selectively stained with an antibody against Thomsen-Friedenreich and the density of the type II pneumocytes was expressed as the number per 1 mm alveolar septal length. The densities of the type II pneumocytes in the severe, the moderate, the mild, and the control groups were 21.2+/-1.1, 14.4+/-7.2, 11.0+/-3.3 and 7.5+/-0.9/mm, respectively. There were significant differences between the acute group and the other three groups, and between the control and chronic groups. The density of type II pneumocytes is a useful index for evaluating alveolar damage even in mild alveolitis.

Biopsy↗

PubMed2003

Duodenogastric reflux and Helicobacter pylori infection synergistically increase gastric mucosal cell proliferative activity in Mongolian gerbils.

BACKGROUND: Helicobacter pylori and duodenogastric reflux (DGR) are both recognized as aetiological factors in chronic gastritis and gastric carcinogenesis. In this study, a Mongolian gerbil (MG) model was used to investigate the histopathological changes in the gastric mucosa resulting from DGR and/or H. pylori infection. METHODS: One-hundred-and-eleven 7-week-old, specific-pathogen-free, male MGs were divided into four groups: normal controls, gerbils with surgically induced DGR, and H. pylori-infected gerbils with and without DGR. Gerbils were killed 4, 12 and 26 weeks after DGR surgery, their stomachs removed and sections prepared. Sections were fixed immediately in 20% phosphate-buffered formalin and subjected to haematoxylin and eosin staining, Alcian blue at pH 2.5/periodic acid-Schiff staining, and immunostaining for smooth muscle cells, H. pylori and 5'-bromo-2'-deoxyuridine (BrdU). RESULTS: The gastric mucosa of H. pylori-infected gerbils showed chronic active gastritis irrespective of DGR throughout the experimental period. The gastric mucosa of H. pylori-infected gerbils with DGR demonstrated higher BrdU labelling than in the other groups. CONCLUSIONS: In MGs, DGR and H. pylori infection synergistically increased gastric mucosal cell proliferative activity. DGR and H. pylori infection may be involved synergistically in gastric carcinogenesis by increasing cell proliferative activity.

Animals↗

PubMed2003

Argon plasma coagulation for successful treatment of early gastric cancer with intramucosal invasion.

BACKGROUND: In recent years, there has been an increasing number of cases of early gastric cancer (T1, NX) with intramucosal invasion, which are untreatable by surgical or endoscopic mucosal resection (EMR) because of their high risk. Currently, no adequate treatment is available for such patients. AIM: The main objective of this study was to evaluate whether argon plasma coagulation (APC) is an effective and safe modality for treating early gastric cancer untreatable by surgical resection or EMR. METHODS: The study group comprised 20 men and seven women diagnosed with gastric cancer with intramucosal invasion who were considered poor candidates for surgical resection or EMR due to risk factors such as severe cardiac failure or thrombocytopenia. Irradiation conditions for APC treatment were determined using swine gastric mucosa. We used an argon gas flow of 2 l/min at a power setting of 60 W and a maximum irradiation time of 15 s/cm(2). The follow up period of the 27 patients ranged from 18 to 49 months (median 30 months). RESULTS: All lesions were irradiated easily, including areas anatomically difficult for EMR such as the gastric cardia or the posterior wall of the upper gastric body. In 26 of 27 patients (96%) there was no evidence of recurrence during the follow up period (median 30 months). One patient showed recurrence six months after the treatment but was successfully retreated. No serious complications were found in any of the 27 patients but three patients (11%) experienced a feeling of abdominal fullness. INTERPRETATION: APC is a safe and effective modality for treatment of early gastric cancer with intramucosal invasion untreatable by surgical resection or EMR. However, further observations are necessary to determine the long term prognosis of patients undergoing this treatment.

Adenocarcinoma↗

PubMed2002

A case of primary low grade mucosa associated lymphoid tissue (MALT) lymphoma of the oesophagus.

We report a very rare case of primary low grade mucosa associated lymphoid tissue (MALT) lymphoma of the oesophagus. An 83 year old woman was referred to our hospital in June 1999 for further examination and treatment of oesophageal tumour. Although a physical examination and laboratory data showed no significant abnormalities, endoscopic observation revealed two slightly elevated submucosal tumour-like lesions of the oesophagus. Tissue specimens were obtained by endoscopic mucosal resection of the oesophagus using a cap fitted panendoscope. The lesions were composed of diffuse small atypical lymphoid cells--that is, centrocyte-like cells--which were stained with CD20, L26, BCL-2, and kappa, but not with CD3, CD5, CD10, or cyclin D1. Monoclonality was detected by polymerase chain reaction analysis using the primer for CDR-3 of immunoglobulin H and diagnosed as low grade MALT lymphoma of the oesophagus. The tumours were considered to be completely resected and therefore additional treatment was not administered. The patient is alive and well 22 months after treatment and diagnosis.

Aged↗

PubMed2001

Dissociation of body-centered and stimulus-centered representations in unilateral neglect.

BACKGROUND: Previous studies on unilateral neglect have shown that there are at least two types of neglect-i.e., body-centered and stimulus-centered neglect. These symptoms suggest that the human brain has at least two different reference frames for processing external space. It is unknown, however, whether these two frames are represented independently in the brain and if so, which areas (or networks) of the brain are responsible for each frame of reference. OBJECTIVE: To determine whether body-centered neglect and stimulus-centered neglect can be dissociated in patients with brain injury. METHODS: New figure discriminative cancellation tasks were designed to simultaneously assess body-centered neglect and stimulus-centered neglect. Two neglect patients with lesions located in different anatomic regions were required to circle every complete figure and to cross out every figure with a missing portion on a sheet of white (29.7 x 42 cm) paper. RESULTS: Patient 1 omitted leftward stimuli on the paper, but the stimuli he found were correctly circled or crossed out. On the other hand, Patient 2 marked stimuli across the paper although he mistakenly circled stimuli that were missing a portion of their left side. Neither patient manifested interaction between the two types of neglect. CONCLUSION: The results of this study clearly showed double dissociation between the two types of neglect. Furthermore, it not only provides evidence that there are two distinct systems of reference frame for external space in the human brain, but also adds new knowledge indicating that these two systems function independently, at least in part.

Aged↗

PubMed2001

Immunohistochemical localization of heparan sulfate proteoglycan in human gastrointestinal tract.

Heparan sulfate proteoglycans (HS-PGs) are associated with important cell functions, for example, cell motility, cell adhesion, and oncogenesis. We examined the localization of HS-PGs in normal and carcinoma tissues of the gastrointestinal tract to help elucidate their roles in these organs. Fresh surgical materials from 134 patients with carcinoma of the stomach or large intestine and 26 patients with various diseases of the small intestine were immunostained after fixation with 10E4 (an antibody against the HS of HS-PG) as a primary antibody. Immunoelectron microscopy (immunogold method) was also performed. The basolateral surfaces of normal tissues of the large and small intestines were strongly stained with antibody confirmed by electron microscopy. In the stomach, lesions with intestinal metaplasia showed the same staining as the intestines, although normal gastric tissue showed staining only in some parts of the basal layer of fundic and pyloric glands. Carcinoma tissues in all cases examined showed staining with antibody. Better results were obtained after fixation in acetic alcohol or zinc-containing solutions than in ordinary formalin. These characteristic localizations of HS-PG in intestines and stomachs suggest that this kind of HS-PG staining could be a hallmark characteristic of the intestine.

Adult↗