Biomedical subjects

S Oguchi

Publications and source records attributed to S Oguchi.

At least 55 records · Page 3Linked to original sources

PubMed1994

In situ localization of transforming growth factor-beta 1 mRNA in the rat kidney with Masugi nephritis.

Masugi nephritis was induced in rats by the administration of nephrotoxic duck serum and, in their kidneys, the distributions of transforming growth factor-beta 1 (TGF-beta 1) mRNA, TGF-beta 1, and macrophage antigenic marker were investigated. Kidney specimens were obtained at 3, 7, and 14 days after the injection. By in situ hybridization, TGF-beta 1 mRNA was found to be localized in the cells of mesangial region from the early stage of nephritis. By the immunohistochemical stainings, TGF-beta 1 was found to be localized in the cells of distal convoluted tubulus throughout the experiments and the macrophage antigenic marker was found to be localized in the occasional cells which were different from that contained TGF-beta 1 mRNA. Our data indicate that TGF-beta 1 mRNA is expressed by the resident glomerular cells and not by the migrating macrophages in rat kidney with Masugi nephritis.

Animals↗

PubMed1994

Helicobacter pylori colonization in children with gastritis and peptic ulcer. I. The colonization rate and effects of colonization on mucin content and mucosal inflammation in the antrum.

The incidence of Helicobacter pylori infection and effects of H. pylori colonization on mucin content and mucosal inflammation of the antral mucosa were studied quantitatively in 55 Japanese children with suspected gastritis and peptic ulcers (aged 6-16 years, mean 12.3 years). H. pylori was detected, using Warthin-Starry stain, in nine of the 22 cases (41%) with antral histological gastritis, but in none of the 33 histologically normal cases. Five out of seven duodenal ulcer cases showed histological gastritis, and all five cases were H. pylori positive. Severity of gastritis, evaluated by means of gastritis score, was significantly higher in H. pylori positive gastritis cases than in H. pylori negative gastritis cases (5.4 +/- 1.0 vs 3.1 +/- 0.3, P < 0.001). A PAS-AB index, a proportion of the periodic acid Schiff-alcian blue (PAS-AB) positive mucin area to the total epithelial area, was significantly lower in H. pylori positive cases than in H. pylori negative cases, irrespective of the existence of histological gastritis (23.5 +/- 7.6% vs 40.4 +/- 5.5%, 43.5 +/- 4.2%, P < 0.001). The decreased mucin content of gastric mucosa is likely to lead to weakening of an important defensive factor of gastric mucosa. These findings suggest that H. pylori plays an important role in gastritis and peptic ulcers in children, especially in cases with duodenal ulcer.

Adolescent↗

PubMed1994

Helicobacter pylori colonization in children with gastritis and peptic ulcer. II. Ultrastructural change of the gastric mucosa.

To evaluate the role of Helicobacter pylori in the pathogenesis of gastritis and peptic ulcer in children, ultrastructural changes of the gastric mucosa with H. pylori colonization were studied in two pediatric patients with duodenal ulcers. The study demonstrated that H. pylori: (i) colonized the mucous layer covering normal gastric epithelium; (ii) lay atop short, irregular microvilli and at the intercellular junctions of damaged cells; and (iii) adhered firmly by specific junction zone (firm connection) and loosely by filamentous appendages to the epithelial surfaces of cells which lacked evidence of a protective mucous layer. The ultrastructural changes, which become progressively worse from patterns (i) to (iii) mentioned above, suggest that these patterns represent distinct and successive stages of the infection. These findings, therefore, lend support to the notion that H. pylori infection is quite common and may relate to the pathogenesis of gastritis and peptic ulcer in children as well as in adults.

Child↗

PubMed1994

Profile of IGF-binding proteins secreted by intestinal epithelial cells changes with differentiation.

Previous reports have shown that gastrointestinal epithelial cells produce insulin-like growth factor-binding proteins (IGF-BP), which modulate the actions of IGF. This study aims to examine the relationship between differentiation and IGF-BP secretion by human intestinal epithelial cells and the effect of growth factors on their production. Caco-2 cells were cultured in serum-free media. IGF-BP secretion into the incubation media was analyzed by Western ligand blotting and immunoblotting. Caco-2 cells produced IGF-BP-2, IGF-BP-3, and IGF-BP-4. Secretion of IGF-BP-2 and IGF-BP-3 increased with differentiation, but IGF-BP-4 secretion diminished. The effect of exogenous growth factors on IGF-BP secretion was maximal at earlier stages of differentiation. IGF-I stimulated mainly IGF-BP-3 production, but epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) stimulated predominantly IGF-BP-4 secretion. Adding an anti-EGF receptor antibody to block autocrine TGF-alpha activity inhibited IGF-BP-4 production but stimulated IGF-BP-2 and IGF-BP-3. In conclusion, the profile of IGF-BP secretion changes with differentiation. IGF-I and EGF (or TGF-alpha) stimulate different types of IGF-BP, with autocrine TGF-alpha activity being a factor affecting IGF-BP production during differentiation.

Antibodies↗

PubMed1993

Insulin-like growth factor binding protein profile secreted by human intestinal epithelial cells varies with polarity.

The actions of insulin-like growth factors (IGFs) are modulated by interaction with a family of secreted binding proteins (IGFBPs). We have now demonstrated in intestinal epithelial cells (Caco-2) that the secretion of different members of this family depends on the cell surface secreting them. Polarized monolayers of cells secreted IGFBP-3 mainly into the medium adjacent to the apical surface, while IGFBP-2 was secreted predominantly through the basolateral surface. The secretion of IGFBP-1 and -4 was equivalent from both surfaces. However, administration of epidermal growth factor (EGF) induced polarized secretion of IGFBP-4 by increasing secretion from the apical surface more than from the basolateral aspect. It did not affect the polarity of the other IGFBPs. We believe that this is the first evidence that epithelial cells can interact with extrinsic agents in a polarized fashion at sites other than the membrane surface.

Adenocarcinoma↗

PubMed1993

Molecular cloning of a cDNA encoding an inducible calmodulin-dependent nitric-oxide synthase from rat liver and its expression in COS 1 cells.

Calmodulin-dependent nitric-oxide synthase, with an apparent molecular mass of 125 kDa, was induced in the liver of rats treated with Propionibacterium acnes and Escherichia coli lipopolysaccharide. Clones were isolated from a cDNA library obtained from induced rat liver using oligonucleotide probes which were synthesized based on the amino acid sequences of peptides of the purified enzyme. Four overlapping cDNA clones for a 3.8-kbp region were isolated and the nucleotide sequences were determined. These clones encompassed an open-reading frame of 3441 bases encoding 1147 amino acids. The deduced amino acid sequence of the cDNA suggested that the protein contains binding sites for NADPH, FAD and FMN. The structure of the possible calmodulin-binding site, consisting of a strongly hydrophobic region surrounded by basic amino acids, is present. The full-length cDNA was expressed in COS 1 cells under the control of a cytomegalovirus promoter and the expressed enzyme was found to be a calmodulin-dependent nitric-oxide synthase. A structural comparison suggested that the liver nitric-oxide synthase is the same as the macrophage enzyme. Northern-blot analysis showed that the mRNA in the liver is approximately 4.2 kb long and is induced transcriptionally by treatment with P. acnes and lipopolysaccharide.

Amino Acid Oxidoreductases↗

PubMed1993

How great is the incidence of truly congenital common bile duct dilatation?

In an attempt to investigate the causes of common bile duct dilatation (CBDD), activity of the pancreatic enzymes in bile aspirated from the dilated duct during laparotomy was measured in 24 children with CBDD. The reasoning behind this is the fact that the existence of activated pancreatic enzymes, namely raised activity of all enzymes accompanied by trypsin activation, can be regarded as an acquired result of an anomalous choledochopancreaticoductal junction (ACP-DJ). All of the pancreatic enzymes measured were activated in 14 cases (58.3%) but no evidence of activation of enzymes, such as trypsin or others except for amylase and lipase, was observed in the remaining 10 cases (41.7%), whether an ACPDJ was present or absent. Eight of the 10 patients with no enzyme activation (33.3% of the total) were less than 2 months old. The findings in these eight infants, which included cystic dilation or hypoplasia of the intrahepatic duct, provide strong suggestive evidence of the congenital nature of these cases. These results suggest that at least one third of CBDD cases are congenital and the remaining cases are either acquired or a combination of congenital and acquired, or both.

Adolescent↗

PubMed1993

The ability of QRST isointegral maps to detect myocardial infarction in the presence of simulated left bundle branch block.

The clinical value of QRST isointegral maps (I-maps) for the detection of myocardial infarction (MI) in the presence of left bundle branch block (LBBB) was investigated. We recorded I-maps during sinus rhythm and right ventricular (RV) pacing, which simulated LBBB, in 62 patients with MI (42 patients had at least one akinetic segment and the remaining 20 patients had only hypokinesis or normal contraction) and 26 patients without MI. An abnormal decrease in the QRST value of the I-map was assessed by the difference map (D-map), which indicated a '-2SD area', where the QRST integral value was less than the lower limit of the normal range (mean -2SD) calculated from 608 normal individuals. The I-maps recorded during the two activation sequences were similar to each other in patients with and without MI (r = 0.87 and 0.92, respectively). The '-2SD area' was located over the left anterior chest in patients with an anterior MI and over the lower torso in patients with an inferior MI during each activation sequence. We were able to diagnose MI during simulated LBBB with a sensitivity of 84%, a specificity of 81% and a diagnostic accuracy of 83% when we used the criterion that MI is present if the sum of QRST integral values below the normal range (sigma DM) exceeds 100 mV.ms. We were able to diagnose an akinesis with a sensitivity of 81%, a specificity of 85% and a diagnostic accuracy of 83% when we used the criterion that akinesis is present if sigma DM exceeds 500 mV.ms during simulated LBBB.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1993

Possible tumor-initiating and -promoting activity of p-methylcatechol and methylhydroquinone in the pyloric mucosa of rat stomach.

The possible tumor-promoting and tumor-initiating activities of p-methylcatechol and methylhydroquinone in the pyloric mucosa of male F344 rats were studied. Ornithine decarboxylase (ODC) and replicative DNA synthesis (RDS) were used as markers of tumor promotion and DNA single strand scission and unscheduled DNA synthesis (UDS) as markers of tumor initiation. The compounds were administered by gastric intubation and results were compared with those after administration of catechol. p-Methylcatechol at doses of 60 to 180 mg/kg body weight dose-dependently induced up to 20-fold increase in ODC activity and 9-fold increase in RDS with maxima 24 h after its administration, but it did not induce significant DNA single strand scission or UDS. Methylhydroquinone at a dose of 200 mg/kg body weight induced up to 6-fold increase in ODC activity 24 h, and 5-fold increase in RDS 16 h after its administration, but the induction was not dose-dependent. At a dose of 200 mg/kg body weight it induced DNA single strand scission, but not UDS. These results and previous findings show that the possible tumor-promoting activities of catechol are several times higher than those of p-methylcatechol and 10 times higher than those of methylhydroquinone.

Adenocarcinoma↗

PubMed1993

Effects of right ventricular pacing on QRST isointegral maps in patients with and without myocardial infarction: body surface distribution of significant changes in QRST area compared to supraventricular complex.

To assess the effects of right ventricular (RV) pacing on body surface QRST distributions, we recorded QRST isointegral maps (I-maps) during sinus rhythm and RV pacing in 25 patients with anterior myocardial infarction (MI), 19 with inferior MI, and 14 without MI. The QRST values at each lead point recorded during sinus rhythm and RV pacing with an 87-lead system were analyzed with a paired t-test in each patient. An abnormal decrease in the QRST value of the I-map was assessed by the difference map, which indicated a "-2SD area," where the QRST integral value was less than the normal range (mean - 2SD) calculated from 608 normal individuals. The I-maps were similar during the two activation sequences in patients with and without MI. However, during RV pacing, QRST values significantly decreased over the upper right anterior chest and increased over the lower left anterior chest and back. The sigma DMs (sum of QRST integral values below the normal range) for both activation sequences were strongly correlated in patients with anterior MI and with inferior MI (r = 0.91 and r = 0.92, respectively; P < 0.001). Although small but significant changes in QRST values were detected, the distribution of the "-2SD area" and the sigma DM were similar during both activation sequences in patients with prior MI. Thus, these findings demonstrate that an altered activation sequence produces small but significant changes in QRST values but that I-maps still provide information that is useful for the diagnosis of MI during RV pacing.

Adult↗

PubMed1993

A patient with primary hyperparathyroidism associated with osteomalacia: markedly increased serum levels of intact PTH and 1,25-dihydroxyvitamin D with normo- and hypercalcemia.

A 65-year-old female patient was admitted with complaining chiefly of lower back pains and arthralgia in the bilateral knee joints of 10-years duration. The serum calcium concentration was normal or only slightly increased, whereas the serum intact PTH and 1,25-dihydroxyvitamin D concentrations were substantially increased. Serum phosphate and 25-hydroxyvitamin D concentrations were decreased. Renal function was normal. Serum alkaline phosphatase activity, the osteocalcin concentration and urinary hydroxyproline excretion were markedly increased. Bone X-ray examination showed severe osteopenia and bone biopsy revealed hyperosteoidosis without tetracycline deposition, consistent with osteomalacia. A parathyroid adenoma was demonstrated by echography and CT-scan. Surgical exploration of the neck revealed a chief cell adenoma behind the right upper pole of the thyroid gland. After parathyroidectomy, all the abnormal biochemical data gradually normalized and the patient has been doing well without any symptoms for the last 13 months. These clinical data suggest that osteomalacia of the patient was probably induced by hypophosphatemia of prolonged duration. When hypercalcemia is not evident in a patient with primary hyperparathyroidism, in whom serum alkaline phosphatase and intact PTH levels are inappropriately increased, osteomalacia should be taken into consideration.

Adenoma↗

PubMed1992

Identification of inducible calmodulin-dependent nitric oxide synthase in the liver of rats.

A calmodulin-dependent nitric oxide synthase was significantly induced in the liver of rats treated intravenously with heat-killed Propionibacterium acnes and 5 days later with Escherichia coli lipopolysaccharide. The apparent calmodulin-dependent and -independent isozymes were separated by Mono Q column chromatography after their partial purification by 2',5'-ADP-agarose affinity chromatography. Both enzymes had a molecular weight of 125,000 as determined by SDS-polyacrylamide gel electrophoresis and required NADPH, tetrahydrobiopterin, and dithiothreitol as cofactors. Their activities were completely inhibited by the specific nitric oxide synthase inhibitors NG-monomethyl-L-arginine and N omega-nitro-L-arginine at 80 and 800 microM, respectively. The peptide maps of these two isozymes with lysylendopeptidase and their reverse-phase column chromatographic profiles were indistinguishable. In the presence of bovine calmodulin, the purified calmodulin-dependent isozyme behaved as a calmodulin-independent isozyme on Mono Q column chromatography. The purified calmodulin-independent isozyme was converted to a calmodulin-dependent isozyme by EDTA and EGTA. Calmodulin blot analysis using 125I-calmodulin showed that the two isozymes bound calmodulin equally efficiently.

Amino Acid Oxidoreductases↗

PubMed1992

Polyclonal antibody against an inducible form of nitric oxide synthase purified from the liver of rats treated with Propionibacterium acnes and lipopolysaccharide.

A polyclonal antibody was raised in the rabbit against an inducible form of nitric oxide (NO) synthase (EC 1.14.23) purified from the liver of rats with acute liver necrosis induced by i.v. administration of Propionibacterium acnes and lipopolysaccharide. The antibody immunoprecipitated NO synthase activities in the soluble extract of the liver from treated rats. Western blot analysis showed that the cytosols of the liver, lung and spleen from the treated rats but not from non-treated rats, and that of murine macrophages cultured in the presence of lipopolysaccharide and interferon-gamma, contained immunoreactive protein with a molecular weight of 125 kDa. The antibody, however, does not cross-react with a 150 kDa constitutive form of NO synthase present in the brain of rats, indicating that the inducible and constitutive enzymes are immunologically distinguishable.

Amino Acid Oxidoreductases↗

PubMed1992

Induction of Ca2+/calmodulin-dependent NO synthase in various organs of rats by Propionibacterium acnes and lipopolysaccharide treatment.

Ca2+/calmodulin-dependent nitric oxide synthase was found to be induced during rat liver necrosis caused by administration of Propionibacterium acnes and E. coli lipopolysaccharide to rats. Examination of the specific induction of Ca2+/calmodulin-dependent NO synthase showed that the enzyme was induced in the lung, spleen and colon as well as the liver. Northern blot analysis revealed that the induction occurred at the transcriptional level.

Amino Acid Oxidoreductases↗

PubMed1992

Purification of nitric oxide synthase from bovine brain: immunological characterization and tissue distribution.

Nitric oxide (NO) synthase (EC 1.14.23) was purified to homogeneity from bovine cerebrum. The molecular weight of NO synthase was estimated to be 150 kDa by both SDS/PAGE and gel filtration at high salt concentration. For activity, the enzyme required NADPH, Ca2+, calmodulin and tetrahydrobiopterin as cofactors. Rabbit polyclonal antibody to bovine brain NO synthase reacted with 150 kDa NO synthase in various bovine and rat organs, including the brain, pituitary and adrenal glands, but not with that in stimulated macrophages, indicating that there are at least two immunologically distinct NO synthases.

Amino Acid Oxidoreductases↗

PubMed1991

[A case of pulmonary arteriovenous fistula accompanied with marked polycythaemia].

A 67-year-old male was admitted with cyanosis, digital clubbing and exertional dyspnea. Laboratory data revealed severe polycythaemia with 26 mg/dl hemoglobin, red blood cell; 866 x 10(-4)/mm3, hematocrit 72.8% and PaO2 44.6 mmHg. Selective pulmonary angiography demonstrated a large arteriovenous fistula involving the right middle lobe. After venesection of 1,200 ml of blood, the middle lobectomy was performed safely. In a case of pulmonary arteriovenous fistula with such severe polycythaemia, preoperative venesection is useful to decrease perioperative complications.

Aged↗

PubMed1989

Prostaglandins in the plasma and stool of children with rotavirus gastroenteritis.

To investigate whether prostaglandins (PGs) are involved in the mechanism of rotavirus diarrhea, PGE2 and PGF2 alpha concentrations in the plasma and stool of children (21 and 16, respectively) with rotavirus gastroenteritis were measured and compared with those of their respective controls. The effect of aspirin on the diarrhea was also studied in 14 patients with rotavirus gastroenteritis. The PGE2 and PGF2 alpha contents of both the plasma and the stool of patients with rotavirus gastroenteritis were significantly higher than in the plasma and stool of the control group. Furthermore, aspirin given by mouth caused the diarrhea to cease earlier. These results suggest that PGE2 and PGF2 alpha are involved as important mediators in the causative mechanism of rotavirus diarrhea.

Aspirin↗

PubMed1989

Possible biological growth factors in breast milk and postnatal development of the gastrointestinal tract.

To investigate as to whether or not biological growth factors known to be present in natural milks could influence postnatal development of gastrointestinal (GI) tract, tests were made to determine the enteric mucosal, protein and DNA contents, alkaline phosphatase and disaccharidase activities in mongrel puppies at birth and after four days of both mother-reared and artificial reared. Microvilli of the jejunal segment were also investigated histologically by electron microscopy. Similar increases in body weight over the first four days of life were obtained and mucosal protein and DNA contents in the small intestine were greater in the mother-reared animals than in the newborn animals but neither mucosal protein content nor DNA content of the artificially reared animals was different from that of the newborn animals. Alkaline phosphatase activity was greater in both the mother-reared and artificially reared animals than that of the newborn animals. The disaccharidase activities were not different among the three groups. The jejunal microvilli of the mother-reared animals were more elaborately grown in the structure than those of the artificially reared or newborn animals. Therefore, this study demonstrated that the mother rearing over the first four days of life resulted in acceleration of the enteric mucosal growth, and the result indicates that breast feeding plays an important role in the development of the GI tract during the neonatal period.

Alkaline Phosphatase↗