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Biomedical subjects

M Otsuki

Publications and source records attributed to M Otsuki.

At least 19 recordsLinked to original sources

Role of beta1 integrins in adhesion and invasion of hepatocellular carcinoma cells.

To investigate the role of integrins in hepatocellular carcinoma (HCC) invasion, we analyzed the relationship between the expression and activity of beta1 integrins and the invasive ability of multiple HCC cell lines. Human HCC cell lines, PLC/PRF/5, Hep3B, HepG2, HLE, HuH7, and C3A cells, had high expression of beta1 and alpha6 subunits, and various levels of alpha1, alpha2, alpha3, and alpha5 expression as determined by cell surface flow cytometry. Activity of beta1 integrins was evaluated by cell adhesion to collagen, fibronectin, and laminin in the presence or absence of the stimulatory anti-beta1 monoclonal antibody (mAb) TS2/16. Different types of HCC cells showed various levels of constitutive activity of beta1 integrins as assessed by the TS2/16 requirement in cell adhesion. TS2/16 rapidly stimulated constitutively inactive or partially active beta1 integrins to fully active states, and as the result, the levels of cell adhesion to each ligand correlated with the expression levels of corresponding beta1 integrins. Thus, in the presence of TS2/16 stimulation, the levels of cell adhesion to collagen, fibronectin, and laminin correlated predominantly with the expression levels of alpha2, alpha5, and alpha6, respectively. Remarkably, as a result of in vitro chemoinvasion assay, the levels of constitutive activity of beta1 integrins correlated with the invasive ability of HCC cells. The inhibitory anti-beta1 mAb 13 almost completely blocked the invasion of PLC/PRF/5 and Hep3B cells that are the most invasive HCC cell lines. Alternatively, the stimulatory anti-beta1 mAb TS2/16 strongly inhibited the invasion. These results not only show an essential role of beta1 integrins in invasion of HCC cells but also suggest subtle regulatory mechanisms of cell invasion.

Antibodies, Monoclonal

Metabolic abnormalities in the genetically obese and diabetic Otsuka Long-Evans Tokushima Fatty rat can be prevented and reversed by alpha-glucosidase inhibitor.

The recently developed Otsuka Long-Evans Tokushima Fatty (OLETF) rat is known to develop insulinopenic diabetes after a prolonged period in a condition resembling non-insulin-dependent diabetes mellitus (NIDDM). We examined the effect of pharmacological intervention with a potent intestinal alpha-glucosidase inhibitor, acarbose, on the metabolic and histopathologic changes in this rat model. The first two groups of rats received an acarbose-rich diet (150 mg/100 g normal chow) from 12 weeks of age (ie, before the onset of diabetes) or from 28 weeks of age (ie, after the onset of diabetes), while a third group received the acarbose-rich diet for the initial 16 weeks only (from 12 to 28 weeks of age). A control group received standard rat chow. Acarbose-fed rats gained less weight or lost weight despite increased food intake when switched to the acarbose-rich diet. Acarbose also reduced visceral adipose depots and fasting triglyceride (TG), glucose, and insulin levels. At the end of the study at 72 weeks, the pancreatic wet weight and insulin content were significantly higher in the treated groups versus control rats. The morphological changes observed in control rats, such as atrophy of the pancreas and reduced number and size of islets, were not present in acarbose-treated rats. Rats fed acarbose from 12 to 28 weeks of age gradually gained weight after switching to standard chow, and hyperinsulinemia, hyperglycemia, and hyperlipidemia appeared (in that order). The pancreatic insulin content in these rats was significantly higher and the visceral adipose depot was significantly smaller than in control rats. Our study demonstrates that acarbose prevented and reversed the metabolic derangement and histopathological changes in genetically diabetic rats. Moreover, treatment with acarbose even for a short period produced a marked delay in the development of insulin insensitivity and frank diabetes.

Acarbose

Pharmacologic profile of TS-941, a new benzodiazepine derivative cholecystokinin-receptor antagonist, in in vitro isolated rat pancreatic acini.

We investigated the pharmacologic characteristics of a newly developed benzodiazepine derivative (S)-(-)-N-[2,3-dihydro-2-oxo-5-phenyl-1-[(1H-tetrazol-5-yl)methyl] -1H-1,4-benzodiazepine-3-yl]-2-indolecarboxamide (TS-941), a cholecystokinin type A (CCK-A)-receptor antagonist, in the isolated rat pancreatic acini and compared with those of well-known CCK-A-receptor antagonists, devazepide and loxiglumide. TS-941 inhibited CCK-8-stimulated amylase release concentration dependently, as did devazepide and loxiglumide, with a half-maximal inhibition (IC50) at 78.6 +/- 10.3 nM. TS-941 was approximately 23 times less potent than devazepide (IC50, 3.4 +/- 0.3 nM), but was 50 times more potent than loxiglumide (IC50, 3,966 +/- 544 nM) in inhibiting 100 pM CCK-8-stimulated amylase release from rat pancreatic acini. TS-941 had a fivefold lower selectivity than devazepide for pancreatic CCK (CCK-A) over brain CCK (CCK-B) receptors but fourfold greater than loxiglumide when IC50 values for inhibition of [125I]CCK-8 binding in isolated acini and cerebral cortex were compared. The antagonism produced by TS-941 was specific for CCK in that the effects of other receptor secretagogues or agents bypassing receptors were not altered. TS-941 caused a parallel rightward shift of the entire dose-response curve for CCK-8-stimulated amylase release without altering the maximal increase, as did devazepide and loxiglumide. TS-941, whether added at the beginning or 20 min after the CCK-8 stimulation, inhibited amylase release. TS-941 caused a concentration-dependent residual inhibition of the action of CCK-8. The acini, once incubated with a high concentration of TS-941 (10 microM; 127 times IC50) for 30 min, was 10-fold less sensitive to CCK-8 than the acini preincubated without TS-941, whereas the sensitivity and the responsiveness to CCK-8 stimulation of those incubated with a low concentration of TS-941 (1.0 microM) were similar to the control acini. These results indicate that TS-941 is a potent, competitive, and selective CCK-A receptor antagonist for the pancreas.

Amylases

Genotypes of alcohol-metabolizing enzymes in relation to alcoholic chronic pancreatitis in Japan.

Long-term consumption of large amounts of alcohol is the main cause of chronic pancreatitis. All heavy drinkers, however, do not contract chronic pancreatitis. Although genetic predisposition to alcoholism and alcoholic liver disease has been reported, genetic susceptibility to alcoholic pancreatitis is still a matter of debate. To determine the relation between genotypes of alcohol-metabolizing enzymes and chronic alcoholic pancreatitis, we examined genotype patterns of aldehyde dehydrogenase 2 (ALDH 2), alcohol dehydrogenase 2 (ADH 2) and cytochrome P-4502E1 (CYP2E1) in 54 patients with chronic alcoholic pancreatitis who were diagnosed in general hospitals in all over Japan and compared with those in 30 patients with chronic nonalcoholic pancreatitis or in 46 alcoholics with normal pancreatic function. There were no significant differences in the distribution of genotypes of ALDH 2 and CYP2E1 among those three groups. As for the ADH 2 genotype, distribution of 2(1)/2(1), 2(1)/2(2), and 2(2)/2(2) was 35%, 30%, and 35% in alcoholics with normal pancreatic function; 4%, 39%, and 57% in the chronic alcoholic pancreatitis group; and 0%, 50%, and 50% in the chronic nonalcoholic pancreatitis group, respectively. The frequency of ADH 2(2) allele was significantly higher in the chronic alcoholic pancreatitis group, compared with alcoholics with normal pancreatic function; but, it was not significantly different from that in the chronic nonalcoholic pancreatitis group. We also examined the relation between pancreatic fibrosis or pancreatitis histologically diagnosed and genotypes of alcohol-metabolizing enzymes in alcoholic autopsy cases. Twenty of 31 cases showed moderate or severe pancreatic fibrosis and showed intralobular + interlobular fibrosis, which is characteristic in alcoholic pancreatitis or intralobular fibrosis. ADH 2(2) allele tended to show a high frequency in the intralobular + interlobular fibrosis group, compared with that in the intralobular fibrosis group (75.0% vs. 41.7%, p < 0.1). The chronic pancreatitis group had a significantly higher frequency of the ADH 2(2) allele than that in cases without such findings (87.5% vs. 58.7%, p < 0.05). However, the ALDH 2 and CYP2E1 genotypes showed no significant relation to the findings of pancreatic fibrosis or histological pancreatitis. These data suggest that the risk of chronic alcoholic pancreatitis diagnosed clinically and pathologically seems to be associated with the ADH 2(2) allele in the genotypes of alcohol-metabolizing enzymes.

Alcohol Dehydrogenase

Recurrent subcutaneous abscess of the sternal region in ulcerative colitis.

An 18-yr-old female patient with extensive ulcerative colitis suffered from several episodes of recurrent aseptic subcutaneous abscesses of the sternal region with a course paralleling that of her colitis. The abscess seemed to occur secondarily to osteomyelitis of the sternum, which is a manifestation of the synovitis, acne, pustulosis, hyperostosis, and osteomyelitis (SAPHO) syndrome.

Abscess

Pure apraxic agraphia with abnormal writing stroke sequences: report of a Japanese patient with a left superior parietal haemorrhage.

A 67 year old Japanese male patient had pure agraphia after a haemorrhage in the left superior parietal lobule. He developed difficulty in letter formation but showed no linguistic errors, consistent with the criteria of apraxic agraphia. He manifested a selective disorder of sequencing writing strokes, although he was able to orally state the correct sequences. The patient's complete recovery after 1 month, without new learning, showed that he had manifested a selective disorder of writing stroke sequences. These findings indicate that the final stage of the execution of writing according to acquired sequential memory shown as a stroke sequence can be selectively disturbed, and should be considered to be distinct from the ability of character imagery and the knowledge of the writing stroke sequence itself. This case also indicates that the left superior parietal lobule plays an important part in the execution of writing.

Aged

Stimulatory effects of vanadate on amylase release from isolated rat pancreatic acini.

The effects of vanadate on exocrine pancreatic function were examined in isolated rat pancreatic acini. Vanadate caused a concentration-dependent stimulation of amylase release above a concentration of 1 mM. Co-incubation of vanadate with vasoactive intestinal polypeptide, 8-bromoadenosine 3':5'-cyclic monophosphate, and the Ca2+ ionophore A23187 produced a synergistic pattern of amylase release, whereas co-incubation with cholecystokinin octapeptide (CCK-8), carbamylcholine, and 12-O-tetradecanoylphorbol 13-acetate produced an additive effect. Vanadate alone had no influence on acinar cyclic AMP content, Ca2+ efflux, or intracellular Ca2+ concentration. However, preincubation with vanadate prevented the plateau phase of CCK-8-induced Ca2+ transient increase from returning to baseline. Moreover, depletion of the intracellular Ca2+ pool by pretreatment of acini with CCK-8 in Ca2+-free medium (plus ethyleneglycol bis[beta-aminoethylether]-N,N'-tetraacetic acid) had no effect on subsequent stimulation by vanadate, although it abolished the response to both CCK-8 and carbamylcholine stimulation. The protein kinase C (PKC) inhibitors staurosporine and calphostin C significantly inhibited vanadate-stimulated amylase release, whereas the protein tyrosine kinase inhibitor genistein had no inhibitory effect. Moreover, vanadate caused a significant translocation of PKC from cytosol to membrane fraction in pancreatic acinar cells. This translocation was inhibited significantly by staurosporine and calphostin C but not by genistein. These results suggest that vanadate acts directly on pancreatic acini and stimulates amylase release by activating PKC without an effect on Ca2+ mobilization, cyclic AMP, or protein tyrosine kinase.

8-Bromo Cyclic Adenosine Monophosphate

Relationship between circulating vascular cell adhesion molecule-1 and microvascular complications in type 2 diabetes mellitus.

The soluble form of the vascular cell adhesion molecule-1 (VCAM-1) is detectable in human sera and is elevated in diabetic patients, with unknown clinical significance. In the present study, the relationship between serum soluble VCAM-1 and diabetic microvascular complications (retinopathy, nephropathy, and neuropathy) was evaluated in 95 Japanese patients with Type 2 diabetes mellitus (DM). Serum soluble VCAM-1 concentration was higher in patients with more advanced stages of retinopathy as well as nephropathy. There was a significant correlation between soluble VCAM-1 and log10 (urinary albumin excretion) in 69 patients with normal serum creatinine levels (r = 0.51, p < 0.0001) and a significant correlation between soluble VCAM-1 and log10 (serum creatinine) in all the patients (r = 0.83, p < 0.0001). Soluble VCAM-1 concentration was also elevated in patients with neuropathy. There was a significant correlation between soluble VCAM-1 concentration and the number of microvascular complications (r = 0.59, p < 0.0001). However, multivariate regression analysis revealed that only diabetic nephropathy, was associated with the soluble VCAM-1 concentration. The elevation of circulating VCAM-1 level in diabetic nephropathy may result from underlying systemic endothelial dysfunction, increased VCAM-1 production in damaged renal tubular or glomerular epithelial cells and/or decreased renal clearance of this molecule, depending on the stage of nephropathy.

Analysis of Variance

Transcortical sensory aphasia following left frontal infarction.

Two right-handed patients who exhibited language disability after left frontal infarction are described. The patients spoke fluently and exhibited excellent repetition ability from the onset of infarction without exhibiting any oral apraxia, but had deficits in auditory comprehension, naming, reading and writing. In both patients, brain magnetic resonance imaging (MRI) revealed infarction in the left inferior frontal gyrus, the middle frontal gyrus and the anterior part of the lower precentral gyrus. Single photon emission computed tomography (SPECT) revealed decreased blood flow in the same regions as those shown to be infarcted by MRI. The MRI and SPECT findings and the symptoms of these patients suggest that left frontal lesions that encompass Broca's area produce fluent aphasia if the posterior part of the left precentral gyrus or motor cortex remains intact and that lesions anterior to Broca's area and the middle frontal gyrus produce a deficit in auditory comprehension of single words as well as sentences.

Aphasia, Wernicke

Defects of cholecystokinin (CCK)-A receptor gene expression and CCK-A receptor-mediated biological functions in Otsuka Long-Evans Tokushima Fatty (OLETF) rats.

Recent studies in genetically obese and diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats suggest defects of cholecystokinin (CCK)-A receptor gene expression and CCK-A receptor-mediated biological functions such as pancreatic juice, protein, and gastric acid secretion. The present studies were undertaken to further examine CCK-A receptor gene expression and CCK-A receptor-mediated biological functions in the pancreas, stomach, and brain of OLETF rats. Expression of the CCK-A receptor gene could not be detected in the stomach, pancreas and brain by the reverse-transcription polymerase chain reaction (RT-PCR) method and Southern blotting of the PCR products. Southern blot analysis of genomic DNA from OLETF and control Long-Evans Tokushima Otsuka (LETO) rats with CCK-A receptor fragment as a probe revealed different restriction bands. Expression of the CCK-B receptor gene was observed in the stomach, pancreas, and brain in both OLETF and LETO rats by the RT-PCR method, with expression of the CCK-B receptor gene markedly enhanced in OLETF rats compared with that in LETO rats. Consistent with the defect of CCK-A receptor gene expression, CCK-A receptor-mediated biological functions were not observed in these organs. Perfused exocrine and endocrine pancreas of OLETF rats were insensitive to CCK stimulation but not to carbamylcholine stimulation. Basal gastric acid and pepsinogen secretions in OLETF rats were higher than in LETO rats. OLETF rats showed a significantly higher average daily food intake, gained body weight faster, and were heavier than LETO rats. The present study confirmed that OLETF rats have CCK-A receptor gene anomalies and demonstrated deficient CCK-A receptor-mediated biological function in the pancreas, stomach, and brain.

Animals

Effects of branched-chain-enriched amino acid solution on insulin and glucagon secretion and blood glucose level in liver cirrhosis.

BACKGROUND: The aim of this study was to determine whether therapeutically used branched-chain amino acids (BCAAs) solution influences glucose metabolism in liver cirrhosis (LC). METHODS: BCAAs solution (200 ml) was infused in LC patients at different stages, and plasma concentrations of glucose and pancreatic hormones were determined. RESULTS: In patients with mild LC, BCAAs caused a significant increase in glucose level (maximal increment, 12.5+/-2.5 mg/dl) with a great increase in insulin (maximal increment, 39.5+/-8.3 microU/ml) and a small increase in glucagon secretion (maximal increment, 101.0+/-16.0 pg/ml). In patients with advanced LC, BCAAs caused a great increase in glucagon secretion (220.5+/-19.4 pg/ml) with only a slight increase in glucose levels (5.8+/-2.2 mg/dl). CONCLUSION: BCAAs solution causes hyperglycemia in mild LC due to insulin resistance, whereas it causes only a slight increase in severe LC due to hepatic glucagon resistance. Thus, there is a possibility that BCAAs solution may lead to hypoglycemia in advanced LC with hepatic glycogen depletion.

Adult

In-vitro and in-vivo antibacterial activities of CS-834, a new oral carbapenem.

We evaluated the in-vitro and in-vivo antibacterial activities of R-95867 and CS-834, a new oral carbapenem which is an ester-type prodrug of R-95867. Against Gram-positive bacteria, R-95867 was as active or two to 256 times more active than cefpodoxime, cefdinir, cefditoren and ofloxacin, while its activity was similar to or two to eight times lower than that of imipenem. Against most Gram-negative bacteria it was as active or two to 1024 times more active than the other compounds tested. Against Helicobacter pylori it was two to 64 times more active than orally active anti-H. pylori agents, i.e. amoxycillin, clarithromycin and lansoprazole. It also showed potent bactericidal activity against Staphylococcus aureus and Escherichia coli. R-95867 induced a spherical form in E. coli and showed high affinity for PBP 2 in E. coli. Against systemic infections in mice caused by various bacteria, CS-834 showed an excellent protective effect and its in-vivo efficacy correlated well with the in-vitro activity of R-95867. These results suggest that CS-834 may be effective in the therapy of various bacterial infections.

Administration, Oral

CCK administration after CCK receptor blockade accelerates recovery from cerulein-induced acute pancreatitis in rats.

We examined the effects of treatment with cholecystokinin (CCK) octapeptide (CCK-8) and the CCK receptor antagonist loxiglumide on the recovery of exocrine pancreas in post-acute pancreatitic rats. Acute pancreatitis was induced in rats by intravenous infusion of 20 microg/kg/h cerulein for 4 h. At 24 h after the start of cerulein infusion, rats were divided into nine treatment groups: oral administration of saline (control), or oral administration of 10 or 50 mg/kg body weight loxiglumide twice daily for the first 3 days, followed by saline administration (Loxi-1 and Loxi-2), 10 or 50 mg/kg body weight loxiglumide twice daily for 6 days (Loxi-3 and Loxi-4), oral administration of saline or 10 or 50 mg/kg body weight loxiglumide twice daily for the first 3 days, followed by subcutaneous injection of 2.5 microg/kg body weight CCK-8 twice daily for the next 3 days (CCK-1, CCK-2, and CCK-3), and subcutaneous injection of 2.5 microg/kg body weight CCK-8 twice daily for 6 days (CCK-4). Pancreatic wet weight and biochemical changes were evaluated on day 8 at 12 h after the last treatment. Treatment with loxiglumide (Loxi-3 and Loxi-4) or CCK-8 for 6 days (CCK-4) or with a high dose of loxiglumide for the first 3 days (Loxi-2) significantly suppressed the recovery of pancreatic weight and DNA content compared to saline treatment or to the untreated normal control rats. However, when loxiglumide treatment was followed by 3 days of CCK-8 injections (CCK-2 and CCK-3), pancreatic protein and DNA content recovered to levels comparable to or above the control levels. The most remarkable increase in enzyme content was obtained in postpancreatitic rats treated with high-dose loxiglumide for the first 3 days, followed by CCK-8 injection (CCK-3). On the other hand, 6 days of CCK-8 treatment (CCK-4) had no significant influences on pancreatic enzyme contents. These results suggest that the most favorable strategy for the treatment of acute pancreatitis is to give high-dose loxiglumide during the early stage for only a short period, followed by CCK-8 administration.

Acute Disease

Exocrine pancreatic physiology: overview.

Exocrine pancreatic physiology has been actively investigated in Japan during the past 30 years. We selected three areas and reviewed them for this article. The selected areas are perfusion of the isolated pancreas, cholecystokinin (CCK)-releasing factor from pancreatic juice (monitor peptide), and genetically diabetic rats. The aim of this article is to present a brief overview of the selected areas of exocrine pancreatic physiology in Japan so that future research can be productively directed.

Animals

Carcinoma of the stomach with hyperkeratosis palmaris et plantaris and acanthosis of the esophagus.

A 59-yr-old man with carcinoma of the stomach, concurrent acquired hyperkeratosis (tylosis) of the palms and soles, and acanthosis of the esophageal mucosa is reported. He presented the tylosis and esophageal lesions when the carcinoma was evident. Resection of the stomach resulted in diminution of the skin and esophageal lesions. The association of sporadic tylosis and carcinoma of the stomach is extremely rare. This is the first case report documenting the association of gastric cancer, tylosis, and acanthosis of the esophageal mucosa.

Adenocarcinoma

Effects of endoscopic variceal ligation on portal hypertensive gastropathy and gastric mucosal blood flow.

OBJECTIVE: Portal hypertensive gastropathy (PHG) has been recognized recently as a potential cause of upper gastrointestinal tract bleeding and is associated with a change in gastric hemodynamic indices in cirrhotic patients with portal hypertension. Endoscopic variceal ligation (EVL) is the treatment of choice for esophageal varices. We investigated the early effect of EVL on PHG and gastric mucosal blood flow (GMBF). METHODS: We examined 35 cirrhotic patients who were treated by EVL. PHG was evaluated endoscopically and GMBF was measured by laser Doppler flowmetry before and 1 or 2 wk after EVL. RESULTS: After EVL, only two patients (5.7%) developed severe PHG, 6 (17.1%) developed mild PHG, and 27 (77.1%) showed no change in endoscopic appearance of PHG. In those patients who developed PHG, EVL significantly decreased GMBF at the corpus (p < .05). However, no significant changes of GMBF at the corpus were noted after EVL in those patients who had no worsening of endoscopic features. EVL had no effect on GMBF at the antrum in any patients. CONCLUSIONS: Endoscopic variceal ligation is safe and does not lead, at least within 1-2 wk, to worsening of gastropathy in most cases. Our finding that gastropathy developed in the presence of reduced GMBF may suggest that PHG develops as a result of congestion caused by blockade of gastric blood drainage rather than by hyperemia.

Adult