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H Ota

Publications and source records attributed to H Ota.

At least 19 recordsLinked to original sources
PubMed1999

Injection of mitomycin-C-treated spleen cells induces donor-specific unresponsiveness to cardiac allografts in rats.

BACKGROUND: In this study, preoperative mitomycin-C- (MMC) treated donor-specific transfusion (DST) was examined for its ability to induce unresponsiveness to cardiac allografts in rats. METHODS: DA (RT1a) rats were used as donors, BUF (RT1b) or WS (RT1k) rats as recipients, and Lew (RT1l) rats as third party donors. BUF or WS rats were given i.v. injection of DA spleen cells (SPCs) suspension (5x10(7)/l ml) with or without MMC treatment 10 days before cardiac transplantation. Delayed-type hypersensitivity and complement-dependent cytotoxicity assays were carried out in these animals separately to examine in vivo immunosuppressive effect. Suppressor assay was also examined to determine in vitro immunosuppressive effects in allogeneic mixed leukocyte culture. RESULTS: In the full allogeneic DA-to-BUF rat strain combination, preoperative i.v. administration of MMC-treated donor SPCs led to a significant prolongation of graft survival over the control (110+/-66 versus 7.2+/-0.8 days: P<0.01), although administration of nontreated donor SPCs did not (9.3+/-1.0 days). This beneficial effect of MMC treatment was also seen in the DA-to-WS rat combination (31+/-16 days versus donor-specific transfusion alone; 11+/-1.5 days or untreated control; 12+/-1.5 days; P<0.05). However, injection of third party DA SPCs in the Lew-to-BUF combination induced no significant prolongation of cardiac allograft survival compared with the untreated control (11+/-0.6 versus 11+/-2.0 days; NS), indicating that this prolongation effect was induced in an antigen-specific manner. The immunosuppressive effect was also secured for both delayed-type hypersensitivity response and anti-donor cytotoxic antibody production. Moreover, addition of MMC-treated SPCs to mixed lymphocyte culture led to antigen-specific suppression. CONCLUSIONS: Preoperative i.v. injection of MMC-treated donor SPCs is promising for inducing unresponsiveness in rat cardiac allograft model.

Adoptive Transfer↗
PubMed1999

Microchimerism in thymus is associated with up-regulated T helper type 1 cytokine transcription during cardiac allograft rejection in rats.

BACKGROUND: Intrathymic microchimerism (MC) is thought to be responsible for inducing allograft tolerance. However, the role of MC in the thymus gland after transplantation, particularly in the rejection response, is unknown. We investigated serial changes in intrathymic cytokine production associated with MC and allograft rejection. METHODS: Donor-specific cell injection (DSI) and heterotopic heart transplantation (HTx) were performed in the fully allogeneic combination using DA rats (RT1a) as donors and WS rats (RT1k)as recipients. MC was checked by polymerase chain reaction (PCR) using a donor RT1.Bbeta domain 1 region sequence-specific primers. Reverse transcription (RT)-PCR analysis of cytokine (interleukin [IL]-2, interferon-gamma, IL-4, and IL-10) profiles of the thymus was performed in animals given DSI, HTx, or DSI/HTx. RESULTS: DSI alone resulted in an immediate development of MC, detected by PCR, in various organs including the thymus, spleen, liver, and blood, of most rats, lasting for over 2 months. However, DSI-induced MC selectively disappeared in the thymus on day 7 after grafting, several days before the rejection of cardiac allograft. RT-PCR analysis of cytokine profiles showed that the levels of Th1 (IL-2 and interferon-gamma) cytokines transcribed in the thymus were higher than in the spleen. MC reappeared in the thymus on day 21 after grafting, but was not associated with elevation of Th1 cytokine transcription when allograft was replaced by fibrosis. CONCLUSIONS: Intrathymic MC does not always confer unresponsiveness to alloantigen, but can be eliminated after anti-donor response.

Animals↗
PubMed1999

Helicobacter pylori-induced chronic active gastritis, intestinal metaplasia, and gastric ulcer in Mongolian gerbils.

The establishment of persisting Helicobacter pylori infection in laboratory animals has been difficult, but in 1996 Hirayama reported the development of a successful Mongolian gerbil model. The present study was undertaken with two aims: to better characterize the normal histological structure and histochemical properties of the gastric mucosa of the Mongolian gerbil; and to evaluate the progression of the histopathological features of H. pylori-induced gastritis in this animal model for one year after the experimental infection. Seventy-five Mongolian gerbils were used. Mongolian gerbils were sacrificed at 2, 4, 8, 12, 26, 38, and 52 weeks after H. pylori inoculation. Sections prepared from stomachs immediately fixed in Carnoy's solution were stained with hematoxylin and eosin and Alcian blue at pH 2.5/periodic acid-Schiff, a dual staining consisting of the galactose oxidase-cold thionin Schiff reaction and paradoxical Concanavalin A staining, and with immunostaining for H. pylori and BrdU. H. pylori infection induced in the Mongolian gerbil a chronic active gastritis, in which a marked mucosal infiltration of neutrophils on a background of chronic inflammation became detectable 4 weeks after inoculation and continued up to 52 weeks. Intestinal metaplasia and gastric ulcers appeared after 26 weeks in some of the animals, whereas others developed multiple hyperplastic polyps. The Mongolian gerbil represents a novel and useful model for the study of H. pylori-induced chronic active gastritis and may lend itself to the investigation of the epithelial alterations that lead to intestinal metaplasia and gastric neoplasia.

Animals↗
PubMed1999

Direct evidence of transformation of dinophysistoxin-1 to 7-O-acyl-dinophysistoxin-1 (dinophysistoxin-3) in the scallop Patinopecten yessoensis.

Non-toxic scallops Patinopecten yessoensis were reared for 5 days with the toxic dinoflagellate Dinophysis fortii sampled from the sea. The total cell number ingested by five scallops during the feeding experiment was approximately 682 x 10(3). Okadaic acid (OA), dinophysistoxin-1 (DTX1) and esterified toxins of OA and DTX1 in D. fortii and scallop extracts were determined by liquid chromatography fluorescence detection (LC-FLD) as their 9-anthryldiazomethane (ADAM) derivatives. Only DTX1 was detected in D. fortii extracts used for the feeding experiment. The content of esterified DTXI in scallops fed on D. fortii was significantly higher than that of DTX1. Identification of esterified DTX1, 7-O-palmitoyl DTX1 (7-O-16:0 DTX1), in D. fortii and scallop extracts was carried out by LC equipped with an atmospheric pressure electrospray ionization-mass spectrometry (ESI-MS). Only extracts of scallops fed on D. fortii yielded a mass spectrum exhibiting abundant [M-H]- at m/z 1055 corresponding to 7-O-16:0 DTX1. These findings are the first direct evidence of the transformation of DTX1 to 7-O-acyl DTX1 in scallop tissues.

Animals↗
PubMed1998

A new histological procedure for re-evaluation of the serological test for Helicobacter pylori.

To re-evaluate the accuracy of the serological test for Helicobacter pylori, fixation of biopsy specimens with Carnoy's solution (preserving the mucous layer in tissue preparations) followed by immunohistochemical staining (a new histological procedure) was used as the reference histological method instead of 10% formalin fixation followed by hematoxylin-eosin staining (the conventional histological procedure). Biopsy specimens (antrum and body) from 114 patients with gastritis (including non-ulcer dyspepsia) or gastric and/or duodenal ulcers were obtained by endoscopy and used for both bacteriological culture and histological examination. Serum samples were taken from all patients at the time of endoscopy. The serum levels of specific IgG and IgA antibodies for Helicobacter pylori were measured by commercial enzyme immunoassay kits. The reliability of the IgG and IgA measurements was evaluated by analyzing receiver operating characteristic curves obtained using the two histological procedures. With the conventional histological procedure as the reference, the sensitivity and specificity levels of the serological test were 87.2% and 82.1%, respectively. With the new histological procedure as reference, sensitivity and specificity were 94% and 96.7%, respectively. The insufficient accuracy reported for the serological test could be due to false-positive or false-negative results obtained when the conventional histological procedure is used as the reference. The new histological procedure used here revealed that the serological test for Helicobacter pylori is more reliable than previously thought.

Antibodies, Bacterial↗
PubMed1998

Protection of islet allografts transplanted together with Fas ligand expressing testicular allografts.

Fas ligand (FasL) is highly expressed in testicular tissues and thought to be responsible for protection from allograft rejection by inducing apoptosis of anti-graft activated T cells. FasL-expressing islets have been shown to induce a granulocyte-mediated inflammatory reaction. We investigated whether a graft can be protected from alloimmune responses by manipulating the Fas/FasL-system. We transplanted allogeneic islets under the kidney capsule of streptozotocin-induced diabetic mice together with testicular tissue. Significant prolongation of survival of C3H islet allograft was observed in C57BL/6 (B6) recipients transplanted with C3H testicular tissue, but not in those transplanted with C3H-gld testicular tissue expressing non-functional FasL. No significant prolongation was observed in B6-lpr recipients expressing non-functional Fas. Immunohistochemical staining of C3H testicular tissue in the composite graft showed a high expression of FasL, but not that of the C3H-gld testicular tissue. In situ terminal deoxynucleotidyl transferase-mediated dUDP-biotin catalysed DNA nick-end labelling (TUNEL) staining of a composite graft of C3H islet and testicular tissue in B6 recipients demonstrated extensive apoptosis of infiltrating mononuclear cells around the graft. The protective effect of C3H testicular tissue was abrogated when anti-FasL monoclonal antibody was administered i.p. postoperatively. Our results suggest that FasL-positive testicular allografts protect composite islet allografts and indicate that manipulation of Fas/FasL mediated apoptosis is a suitable strategy for controlling rejection of islet allografts.

Animals↗
PubMed1998

New monoclonal antibodies against gastric gland mucous cell-type mucins: a comparative immunohistochemical study.

The immunohistochemical reactivity of monoclonal antibodies raised against rat and pig gastric mucins (HIK1083, PGM36, and PGM37) was investigated in normal gastrointestinal tracts obtained from fish, amphibians, reptiles, birds, and mammals (including humans). These monoclonal antibodies exhibited highly selective reactivity with class III mucins, as identified by paradoxical concanavalin A stain, in the gastrointestinal tract of vertebrates. All three monoclonal antibodies reacted with the mucous neck cells and pyloric gland cells of amphibians, reptiles and mammals, the cardiac glands of reptiles and mammals, and Brunner's glands of mammls. The deep crypt secretory cells of the rat colon and certain goblet-type cells deep in crypts in the pig colon differed from the above pattern only in that they did not show immunoreactivity with monoclonal antibody PGM36. These data suggest that the development of class III mucin is a fundamental evolutionary characteristic of vertebrate gastric mucins. These monoclonal antibodies should prove useful for the investigation of cell differentiation among gastrointestinal mucous cells and for the biochemical analysis of gastrointestinal mucins in different species.

Animals↗
PubMed1998

Helicobacter pylori infection produces reversible glycosylation changes to gastric mucins.

The protective ability of gastric mucins may depend largely on their oligosaccharide chains. We evaluated the effects of H. pylori infection on the glycosylation of gastric mucins. Gastric biopsy specimens from 20 H. pylori-infected patients before and after cure of the H. pylori infection and 8 normal uninfected volunteers were examined by immunostaining for simple mucin-type glycoproteins and blood-group-related antigens bearing type 1 chain backbone. The immunoreactivity in different gastric compartments was evaluated. Simple mucin-type glycoproteins and blood-group-related antigens were expressed in surface mucous cells. Simple mucin-type glycoproteins showed antrum-predominant expression in normal volunteers and were found in significantly fewer surface mucous cells in infected patients than in normal volunteers; their expression was restored after eradication of H. pylori. Sialyl Lewis(a) and Lewis(b) were expressed in fewer surface mucous cells after than before eradication. The patterns of glycosylation of gastric mucins vary in different gastric compartments and are reversibly altered by H. pylori infection. These alterations may affect the protective functions of gastric mucins.

Adult↗
PubMed1998

Older drivers fail in intersections: speed discrepancies between older and younger male drivers.

A high percentage of older drivers' accidents occur in intersections when entering the traffic or crossing a main road. The problems may be in perception or attention, motor performance or inadequate interaction with other road users. Attempts to explain older drivers' problems have mostly focused on the properties and behaviour of the older drivers only, without considering the interaction between older and younger road users. The descriptions of older drivers' problems in intersections are usually based on accident data. This study aimed to describe the normal behaviour of older drivers, including driving habits, attention patterns and interaction with younger drivers. The driving behaviour of young, old and middle-aged male drivers was studied using video cameras and observers in three T-shaped intersections in Sendai, Japan. The results showed no differences in attention behaviour between the age groups as measured with head movements. The age groups had different acceleration habits and thus different turning time, which also varied depending on whether the vehicle on the main road came from the left or the right. Also the outcome of the turning manoeuvre was dependent on age. The time margins to the vehicles on the main road were shortest when an old driver was turning and a young driver approached on the main road. The time margin between the turning driver and the vehicle approaching on the main road was clearly shorter when the latter vehicle was a motorcycle than if it was a car. The results are discussed in relation to the literature on the risk behaviour of old drivers.

Age Factors↗
PubMed1998

Endothelial nitric oxide synthase in the endometrium during the menstrual cycle in patients with endometriosis and adenomyosis.

OBJECTIVE: To determine the expression of endothelial nitric oxide synthase in the endometrium during the menstrual cycle in endometriosis and adenomyosis. DESIGN: Immunohistochemical identification of endothelial nitric oxide in endometrial tissues using the monoclonal antibody. SETTING: Department of obstetrics and gynecology in a university hospital. PATIENT(S): The subjects were divided into three groups: 35 patients with endometriosis, 33 patients with adenomyosis proven histologically, and 46 fertile controls. MAIN OUTCOME MEASURE(S): Semiquantitative immunostaining (evaluation nomogram) score in endometrial cells. RESULT(S): The analyses revealed phase-dependent changes in the expression of endothelial nitric oxide synthase in the surface and glandular epithelia during the menstrual cycle in the fertile controls. The expression was weakest in the early proliferative phase, gradually increased, was most marked in the midsecretory phase, and decreased thereafter. In contrast, stromal cells did not change throughout the cycle. Contrary to expectations, the expression of endothelial nitric oxide synthase in endometriosis and adenomyosis was persistently greater than the control levels throughout the menstrual cycle. CONCLUSION(S): This study has shown that endothelial nitric oxide synthase is changed in a phase-dependent manner during the menstrual cycle. The exaggerated expression of endothelial nitric oxide synthase in the endometrium throughout the cycle suggests some pathologic role in endometriosis and adenomyosis.

Adult↗
PubMed1998

Intestinal metaplasia with adherent Helicobacter pylori: a hybrid epithelium with both gastric and intestinal features.

Helicobacter pylori seem to avoid areas of intestinal metaplasia in the gastric mucosa, but attachment of these bacteria to epithelium with the appearance of incomplete intestinal metaplasia has been documented. To characterize the nature of the epithelium to which H pylori was attached, we carried out an immunohistochemical study using monoclonal antibodies against gastric surface mucous cell mucins (M1), blood group-related carbohydrates antigens (Le(a), sialyl Le(a), Le(b), type 1H, and type 2H) and sialyl Tn antigen. The results of this study suggest that these areas of H pylori attachment represent a hybrid epithelium whose cells share characteristics of both gastric surface mucous cells and intestinal metaplastic cells. Whether all areas of incomplete intestinal metaplasia represent an intermediate stage between the normal gastric epithelium and the fully developed complete type of metaplasia remains to be determined.

ABO Blood-Group System↗
PubMed1998

Comparison of four monoclonal antibodies reacting with gastric gland mucous cell-derived mucins of rat and frog.

Features of four monoclonal antibodies (MAbs), PGM36, PGM37, PGM38 and HIK1083, reacting with the mucin derived from rat gastric gland mucous cells were compared. By applying enzyme linked immunosorbent assay, all of these MAbs reacted not only with the mucins purified from both rat and frog stomach, but also with the oligosaccharides obtained from the antigenic mucins by alkaline borohydride treatment. These MAbs could be characterized as distinct MAbs due to the immunohistochemical observation of rat cecal mucosa and the reactivity to paranitrophenyl derivatives of monosaccharides. These MAbs might be useful tools to compare the gastric gland-type mucins in different species of vertebrates and to investigate the heterogeneity of the carbohydrate structure of the mucin molecules of various origins.

Animals↗
PubMed1998

Acquisition versus loss of Helicobacter pylori infection in Japan: results from an 8-year birth cohort study.

Studies of the pattern of change in the epidemiology of Helicobacter pylori infection are scarce. A longitudinal cohort study consisted of 644 children and adults, and two independent cross-sectional surveys were conducted in rural Japan between 1986 and 1994. The anti-H. pylori IgG seroconversion rates were 1.1% and 1% per year for children and adults, respectively. The seroreversion rate per year was 1.8% for children and 1.5% for adults. The cohort study was confirmed by the two cross-sectional studies. H. pylori prevalence fell in all age groups in both children (odds ratio [OR] = 0.5, 95% confidence interval [CI] = 0.2-1.0, P = .05) and adults (OR = 0.4, 95% CI = 0.3-0.6, P = .001). The rate of loss of H. pylori infection was greater than the acquisition. Data regarding acquisition and loss of H. pylori infection are critical to understanding the epidemiology of the infection and to developing treatment and vaccination strategies.

Adolescent↗
PubMed1998

Mucinous bronchioloalveolar carcinoma with organoid differentiation simulating the pyloric mucosa of the stomach: clinicopathologic, histochemical, and immunohistochemical analysis.

Seven cases of mucus-producing bronchioloalveolar carcinoma, which showed organoid differentiation simulating the gastric pyloric mucosa, were found among 176 cases of lung cancer. This type of adenocarcinoma, which corresponds to bronchioloalveolar carcinoma with mucus-secreting cells in the World Health Organization classification, characteristically formed papillary structures composed of two types of mucus cells: tall columnar cells in the upper portion of the papillary structure and more cuboidal cells in the lower portion. The former contained gastric surface mucous cell-type mucins that stained with galactose oxidase-cold thionine Schiff, whereas the latter possessed gastric gland mucous cell-type mucins specifically stained by paradoxical concanavalin A and were also positive for lysozyme and pepsinogen II by immunostaining. Chromogranin A-reactive tumor cells were also scattered among these tumor cells. This pattern of mucus-secreting cells, therefore, simulated the normal pyloric mucosa of the stomach.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1998

Histochemical analysis of mucous cells of congenital adenomatoid malformation of the lung: insights into the carcinogenesis of pulmonary adenocarcinoma expressing gastric mucins.

Adenocarcinomas expressing gastric mucins often are accompanied by ectopic gastric mucosa or pyloric metaplasia. We have previously described mucinous bronchioloalveolar carcinoma (mucinous BAC) producing gastric mucins. In the lung tissue, mucous cells seemingly similar to gastric mucous cells are present in congenital adenomatoid malformation (CAM). We assessed 26 cases of CAM morphologically and histochemically. Mucous cells were detected in 12 of 26 cases. These mucous cells displayed papillary growth in cystic spaces and proliferated along alveolar walls. Mucous cells in the papillary, configuration stained with galactose oxidase cold thionine Schiff reaction, and those in indented portions stained with paradoxical concanavalin A stain in all 8 cases and with pepsinogen II in 5 of 8 cases, which were available for histochemical analysis. Pepsinogen I was negative. Mucous cells in CAM were identical to those of pyloric mucosa and could be considered candidates for the origin of mucinous BAC producing gastric mucins.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1998

The complete nucleotide sequence of a snake (Dinodon semicarinatus) mitochondrial genome with two identical control regions.

The 17,191-bp mitochondrial DNA (mtDNA) of a Japanese colubrid snake, akamata (Dinodon semicarinatus), was cloned and sequenced. The snake mtDNA has some peculiar features that were found in our previous study using polymerase chain reaction: duplicate control regions that have completely identical sequences over 1 kbp, translocation of tRNALeu(UUR) gene, shortened TpsiC arm for most tRNA genes, and a pseudogene for tRNAPro. Phylogenetic analysis of amino acid sequences of protein genes suggested an unusually high rate of molecular evolution in the snake compared to other vertebrates. Southern hybridization experiments using mtDNAs purified from multiple akamata individuals showed that the duplicate state of the control region is not a transient or unstable feature found in a particular individual, but that it stably occurs in mitochondrial genomes of the species. This may, therefore, be regarded as an unprecedented example of stable functional redundancy in animal mtDNA. However, some of the examined individuals contain a rather scanty proportion of heteroplasmic mtDNAs with an organization of genes distinct from that of the major mtDNA. The gene organization of the minor mtDNA is in agreement with one of models that we present to account for the concerted evolution of duplicate control regions.

Amino Acid Sequence↗
PubMed1998

Morphometric evaluation of stromal vascularization in the endometrium in adenomyosis.

A computerized morphometric investigation of stromal vascularization in the endometrium during adenomyosis was performed retrospectively. Using a polyclonal antibody and a peroxidase-antiperoxidase method, formalin-fixed paraffin sections of the tissue were stained for von Willebrand factor, a marker for endothelium. The subjects were divided into two groups: 42 patients with histologically proven adenomyosis and 29 fertile control subjects, 12 in the proliferative phase and 17 in the secretory phase. Objective quantitative colour image analysis was used to assess the staining intensity and hence the degree of vascularization. In the control group, stromal vascularization increased in the secretory phase. In adenomyosis, vascularization increased markedly, up to 11.6 times that of the controls, in terms of the in total surface area of capillaries per mm2 in the endometrium in the proliferative phase. These findings suggest clinical relevance to severe functional disturbances such as hypermenorrhoea or iron deficiency anaemia.

Adult↗