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Biomedical subjects

T Toyota

Publications and source records attributed to T Toyota.

At least 271 records · Page 15Linked to original sources
PubMed1991

[Point mutation of c-k-ras oncogene at codon 12 in mucin-producing cystic tumor of the pancreas].

The point mutation of c-K-ras oncogene at codon 12 was investigated in 15 cases of mucin-producing cystic tumor of the pancreas by a modified polymerase chain reaction (PCR) method. Three percent formalin-fixed and paraffin embedded materials were employed for the present investigation. These fifteen cases were histopathologically classified into five categories (from group I to V) according to Kozuka's classification which was based on cell atypia of the tumor cells; 5 cases were judged as group V, 4 cases as group IV, and 6 cases as group III. The frequency of point mutation was 5/5 in group V, 3/4 in group IV, and 2/6 in group III. The frequency of point mutation was correlated with morphologically determined cell atypia. Among group III, the point mutation was noticed in the cases with larger tumor size. From genetical point of view, the results indicated more malignant biological feature of mucin-producing cystic tumor of the pancreas than has generally been accepted.

Aged↗
PubMed1991

[Salivary epidermal growth factor in patients with peptic ulcer].

Recent animal studies suggest salivary epidermal growth factor (EGF) has a cytoprotective effect in the upper GI tract and is one of the important factors to promote the healing of experimental ulcer. The present study was undertaken to clarify the role of salivary EGF in peptic ulcer patients. Saliva samples were collected from 129 endoscopically normal subjects and 232 peptic ulcer patients. Salivary EGF concentration was measured by RIA. Salivary EGF output in normal subjects was 5.26 +/- 0.26 (ng/5 min) (mean +/- SE). Those in patients with gastric ulcer (GU), duodenal ulcer (DU) and gastroduodenal ulcer (GDU) were 10.74 +/- 0.15, 8.13 +/- 0.83 and 9.79 +/- 0.91. EGF output in GU and GDU patients were higher than that in normal subjects respectively. Tractable GU patients (healed within 3 months with regular regimen) had higher EGF output than intractable GU patients. Among tractable GU patients, those who had healing within 8 weeks had higher output. EGF output in patients with recurrent GU was lower than that in non-recurrent GU patients. In 10 GU patients, EGF output became higher in healing stage than in active stage. Salivary EGF may promote the healing and prevent the recurrence of human gastric ulcer.

Adult↗
PubMed1991

[A cytoprotective role of extracellular superoxide dismutase in experimental stress ulcer models].

In an experimental stress ulcer models, we examined a pathophysiological role of EC-SOD in an extracellular fluid in guinea pig. Heparin has a releasing potency of EC-SOD into extracellular fluid from endothelial cell. In this study, we divided animals into four groups; 1) control animals, 2) animals injected with heparin (1,000 IU/kg), 3) animals injected with heparin and DDC (1 g/kg), 4) animals injected with DDC treatment. In these four groups, we measured ulcer index (UI) and lipid peroxides (LPO) of the gastric mucosa, before and serially after stress. Water-immersion, ethanol and burn were used as experimental stress. Animals injected with heparin inhibited the increase of UI and LPO of gastric mucosa induced by stress. This cytoprotective effect was abolished by DDC treatment. These results suggest that EC-SOD may be a cytoprotective factor in an extracellular fluid.

Animals↗
PubMed1990

Inhibition of type 1 diabetes in BB rats with recombinant human tumor necrosis factor-alpha.

We previously reported that streptococcal preparation (OK-432), which is a TNF inducer, inhibits insulitis and development of autoimmune diabetes in nonobese diabetic (NOD) mice and Bio-Breeding (BB) rats, as animal models of insulin-dependent diabetes mellitus. We have recently shown that recombinant human (h)TNF-alpha also suppresses development of diabetes in NOD mice. In this study we have extended our observation on TNF to BB rats in order to see whether TNF generally inhibits autoimmune diabetes. A total of 5 x 10(4) U of rhTNF-alpha was administered i.p., twice a week to male and female BB rats from 4 to 27 wk of age. The cumulative incidence of diabetes by 27 wk of age in nontreated rats was 36.4% (8/22), whereas that in hTNF-alpha-treated rats was 0% (0/21) (p less than 0.001). The hTNF-alpha-treated rats did not lose body weight and maintained normal blood glucose concentrations. Immunologic and histologic examinations were performed at the end of the experiment. Spleen cell cytotoxicities for NK-sensitive YAC-1 and rat insulinoma (RINm5F) cells in hTNF-alpha-treated rats significantly decreased in comparison with nontreated and nondiabetic BB rats. Intensity of insulitis was also inhibited in hTNF-alpha-treated rats. Interestingly, a huge hepatomegaly and splenomegaly was found in two of the 21 hTNF-alpha-treated rats. The latter consisted of W3/13dull+ and W3/25dull+ cells, which did not exhibit cytotoxicity for either YAC-1 or RINm5F cells. These results indicate that the chronic and systemic administration of TNF has a regulatory role in autoimmune diabetes in BB rats as well as in NOD mice, and that these animals may have a defect in TNF-mediated immunoregulation.

Animals↗
PubMed1990

Mechanism of action of a streptococcal preparation (OK-432) in prevention of autoimmune diabetes in NOD mice. Suppression of generation of effector cells for pancreatic B cell destruction.

We have previously reported that treatment with a streptococcal preparation (OK-432), one of the biologic response modifiers, inhibits insulitis and development of autoimmune diabetes in nonobese diabetic (NOD) mice and Bio-Breeding rats used as animal models of insulin-dependent diabetes mellitus (IDDM). We studied the mechanism by which OK-432 inhibited development of IDDM in NOD mice. In female NOD mice diabetes spontaneously developed from 10 to 15 wk of age and the cumulative incidence of diabetes amounted to 74.7% at 30 wk of age. NOD mice, however, never developed diabetes over the observation period of up to 45 wk of age when they were i.p. injected with 0.1 mg of OK-432 weekly from 4 to 15 wk of age. OK-432 treatment in younger age had a stronger inhibitory effect on the development of diabetes. Diabetes was transferred to young, irradiated mice by spleen cells of nontreated, adult mice, but barely transferred by those of OK-432-treated mice. Furthermore, these spleen cells of OK-432-treated mice did not suppress transfer of diabetes by diabetic mice spleen cells. Treatment with cyclophosphamide promoted development of diabetes in nontreated NOD mice due to removal of suppressor cells. However, cyclophosphamide did not show the promotive effect in OK-432-treated mice. Taken together, these results indicate that OK-432 treatment prevented development of diabetes mainly by suppression in generation of the effector cells for pancreatic B cell destruction. The same OK-432 treatment did not suppress the immune response to exogenous AG such as xenogeneic SRBC and allogeneic tumor cells. The study suggests that BRM in the natural environment such as streptococci may suppress induction and progression of autoimmunity and be useful for the immunotherapy of human IDDM.

Animals↗
PubMed1990

Endoscopic treatment for submucosal tumors of the esophagus: studies in 25 patients.

Twenty-five patients with submucosal tumor of the esophagus were treated endoscopically. All patients underwent submucosography. The tumors were classified as intra-luminal or intra-mural types according to growth pattern. Twenty tumors were resected using electrocautery in single sessions. Another 5 lesions (more than 20 mm in diameter) were subjected to absolute ethanol injections in multiple sessions to necrotize the tissue, after the overlying mucosa was stripped off by electrocautery. These procedures were not accompanied with serious complications such as perforation or massive bleeding. Oozing bleeding occurred in 3 patients, which was easily stopped by topical injection of absolute ethanol with an endoscope. Esophageal stenosis did not occur. Local reccurence of a submucosal tumor was found in a patient after 14 months, and was retreated successfully. Although the wall of the esophagus is thinner than that of the stomach, endoscopic treatment for a submucosal tumor of the esophagus can be performed safely. Submucosography and endoscopic ultrasonography reveals the extent of the tumor in relation to the esophageal wall thickness. These examinations are helpful in preventing complications. Endoscopic treatment for submucosal tumors using electrocautery and topical injection of absolute ethanol were effective and safe.

Adult↗
PubMed1990

A new prostaglandin E1 analogue (TFC-612) improves the reduction in motor nerve conduction velocity in spontaneously diabetic GK (Goto-Kakizaki) rats.

A new prostaglandin E1 analogue, TFC-612, was given orally to 2 month-old spontaneously diabetic GK (Goto-Kakizaki) rats for 3 months to ascertain its effects on reduced motor nerve conduction velocity (MCV). A high dose of this compound (0.3 mg/kg body weight) significantly restored MCV after 2 and 3 months of administration, although the low dose (0.03 mg/kg body weight) did not. In addition, 1 month administration of TFC-612 significantly improved the reduced MCV in aged (5 month-old) GK rats only in the high dose group (0.3 mg/kg body weight), but not in the low dose group (0.03 mg/kg body weight). Although TFC-612 significantly suppressed sorbitol accumulation in the sciatic nerves of GK rats in a dose dependent manner after 3 months administration, this suppression was not observed after either 2 months administration to 2 month-old GK rats or after 1 month administration to 5 month-old GK rats. Fasting blood glucose levels of all GK rats remained high throughout the experiments, regardless of TFC-612 administration. TFC-612's improvement on reduced motor nerve conduction velocity was related partly to suppression of sorbitol accumulation, but other factors, including microcirculation, may contribute significantly to this effect. These results suggest that TFC-612 may be beneficial in the treatment of diabetic nerve impairment.

Aging↗
PubMed1990

Immunogenetics of early-onset insulin-dependent diabetes mellitus among the Japanese: HLA, Gm, BF, GLO, and organ-specific autoantibodies--the J.D.S. study.

The Japan Diabetes Society (JDS) conducted a multicenter study on the immunogenetics of early-onset insulin-dependent diabetes mellitus (IDDM) of the Japanese. Human leukocyte antigen (HLA), properdin factor B (BF), immunoglobulin heavy-chain complex (Gm), and glyoxalase of erythrocytes (GLO) were typed, and organ-specific autoantibodies, including islet cell antibody (ICA), were assayed in 159 Japanese IDDM patients and their family members and in 258 healthy Japanese controls. The HLA-DRw9 phenotype and HLA-Bw61/DRw9 haplotype were significantly increased among the patients with autoantibodies other than ICA but with no autoimmune diseases (RR = 5.84, cP less than 0.001; and RR = 7.45, P less than 0.001), whereas the HLA-DR4 phenotype and HLA-Bw54/DR4 haplotype were significantly increased in those without either the autoantibodies or autoimmune diseases (RR = 2.64, cP less than 0.001; and RR = 4.55, P less than 0.001). The HLA-DR4 phenotype was significantly increased in the patients with autoimmune thyroid diseases (RR = 6.21, cP less than 0.05). In all groups of patients, the HLA-DR2 phenotype was significantly decreased, and the relative risk of the HLA-DRw9/DR4 genotype was highest among all HLA-DR genotypes. No significant association was found between HLA type and the duration or incidence of ICA. Gm types of g and gft were significantly increased in the patients with the autoantibodies (RR = 2.11, P less than 0.05; and RR = 34.11, P less than 0.05), whereas the BF-F phenotype was significantly decreased in the patients either with or without autoantibodies (RR = 0.43, P less than 0.05; and RR = 0.46, P less than 0.05). There was no association between IDDM and GLO type. These data indicate that immunogenetic bases underlying IDDM of the Japanese are heterogeneous, as are those in Caucasians.

Autoantibodies↗
PubMed1990

[Diaphragmatic electromyography (DEMG) in achalasia patients].

LES pressure increase following diaphragmatic contraction as a pinch-cock action acts as one of the barrier mechanism for gastroesophageal reflux. In achalasia patients, incomplete LES relaxation following wet swallow is one of the characteristic manometric findings, along with loss of peristalsis. On the other hand, it has been reported that swallowing effort or esophageal distention have no effect on the increase of LES pressure induced by diaphragmatic contraction, which condition is similar to achalasia. Therefore, to evaluate that whether diaphragmatic contraction is involved in the cause of achalasia, we recorded diaphragmatic electromyography (DEMG) using bipolar electrodes in 12 achalasia patients and 4 normal subjects. The phasic DEMG amplitude was 80-90 microV in normal subjects and achalasia patients. LES pressure and DEMG amplitude increased during both straight leg raising (SLR) and abdominal distention (AD), both of the maneuver induce diaphragmatic contraction, in normal subjects and achalasia patients similarly. From the data obtained with this equipment, we conclude that diaphragmatic involvement is not likely as a pathogenesis of LES dysfunction in achalasia patients.

Adult↗
PubMed1990

[Effect of feeding on recording characteristics of electrogastrography (EGG) in normal subjects].

Cutaneous recording of electrogastrography reflects gastric mechanical activity. Epigastric leads are superior in recording characteristics than meso-gastric leads, in fasting state, 3.0 cpm waves dominate EGG recording in fasting state. In this study, we analyzed the EGG recording characteristic after feeding in 10 normal subjects. Though the physical changes of gastric shape and volume after feeding, EGG recording was dominated by 3.0 cpm waves. Epigastric leads are still superior in recording characteristics, amplitude of EGG waves and read-abilities, than meso-gastric leads, after feeding. Amplitude of EGG waves increased after feeding when compared to fasting state, suggesting increased mechanical activity of the stomach. We conclude that epigastric leads are suitable in recording of EGG in fasting and in fed state in normal subjects. This position could be most standard recording leads for EGG in clinical settings.

Action Potentials↗
PubMed1990

Production of tumor necrosis factor alpha and interleukin 1 beta by peripheral blood mononuclear cells from chronic hepatitis type C patients during interferon therapy.

To elucidate the role of tumor necrosis factor alpha (TNF-alpha) and interleukin 1 beta (IL-1 beta) in chronic hepatitis type C (CH(C], TNF alpha and IL-1 beta released from peripheral blood mononuclear cells were measured in 6 CH(C) patients before and during interferon therapy. During the therapy, TNF-alpha levels were significantly high in two patients whose serum ALT levels turned normal, while IL-1 beta levels did not show significant change. These results suggest that TNF-alpha takes part in improvement of CH(C).

Hepatitis C↗
PubMed1990

Production of monoclonal antibodies against recombinant HBcAg.

Three monoclonal antibodies against recombinant HBcAg were obtained from hybridomas fused between mouse myeloma line NS1 and splenocytes of immunized Balb/C mice. They specifically bound to recombinant HBcAg. Subtypes of these monoclonal antibodies were IgM and IgA.

Animals↗