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Biomedical subjects

Y Komuro

Publications and source records attributed to Y Komuro.

At least 55 records · Page 3Linked to original sources
PubMed1995

Effects of lansoprazole on gastric ulcer healing and mucin content.

The effect of lansoprazole, a new benzimidazole proton pump inhibitor, on the relationship between ulcer healing and changes in mucin content was studied in gastric ulcer patients. Twenty-one outpatients with active gastric ulcers received lansoprazole 30 mg once daily given in the morning for 8 weeks. The gastric mucin content was examined by HPLC analysis of hexosamines in gastric biopsy specimens obtained from the lesser curvature of the pylorus and the greater curvature of the upper body. The ulcer healing rate for lansoprazole was 85.7% at 8 weeks. The mucin content of both mucosal regions significantly decreased to approximately 70% (pylorus 70.9%; upper body 74.7%) of the value before drug treatment. The results of this study demonstrate that 30 mg lansoprazole once daily is remarkably effective in healing gastric ulcers because of its potent acid suppression. It appears that acid inhibition is the primary factor in initial treatment. However, maintaining an altered gastric mucosal defense mechanism may have implications for the long-term treatment of gastric ulcers.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1994

Effects of the new histamine H2 receptor antagonist, FRG-8813, on gastric mucin in rats with or without acidified ethanol-induced gastric damage.

It is not presently well understood whether the histamine H2 receptor antagonist has a function other than the inhibition of gastric acid secretion, such as the effect on the gastric mucosal defence mechanism. In this paper, we report the effect of FRG-8813 (N-[4-[4-(piperidinylmethyl)pyridyl-2-oxy]-(Z)-2-butenyl]-2- (furfurylsulfinyl) acetamide), a new histamine H2 receptor antagonist, on the rat gastric mucin content with or without 0.15N HCl-ethanol (60 %)-induced gastric damage. The prior administration of FRG-8813 significantly inhibited the occurrence of macroscopically observable hemorrhagic lesions induced by the acidified ethanol treatment. Using a newly developed biochemical method, the mucin content of the deep corpus and antral mucosa of the acidified ethanol-treated animals was significantly reduced to 50% and 32% of the control, respectively. These reductions were inhibited by the pretreatment with FRG-8813. Total mucin content in the entire stomach recovered to about 80% of the control value after pretreatment with FRG-8813. A single oral administration of FRG-8813 (30 mg/kg) caused no significant change in the total mucin content, but mucin in the adherent mucus gel layer selectively and significantly increased to 250% of the control. These results suggest that FRG-8813 not only inhibits acid secretion but may also affect the gastric mucosal defensive mechanism as well.

Acetamides↗
PubMed1994

Correction of the cleft nasal deformity with an L-shaped iliac bone graft.

We describe our technique for correcting a cleft lip nasal deformity using L-shaped iliac bone grafts to achieve additional structural support and the desired nasal projection and profile. Augmenting the nasal bridge creates the illusion of a narrower nose. Further, the columellar portion of the L-shaped graft provides stabilization, eliminating the "see-saw" effect of the bridge graft on the fulcrum of the bony bridge, which can lead to a depressed tip and loss of the root indentation. Clinical and radiographic observation has revealed that this method of correction has consistently produced satisfactory results.

Adolescent↗
PubMed1994

The histologic analysis of distraction osteogenesis of the mandible in rabbits.

The process of bone formation in mandibular lengthening by distraction was studied in 30 rabbits. The mandible was subjected to a corticotomy, held in a neutral position for 2 weeks, and then lengthened at 0.18 mm per 12 hours for 24 days using a unilateral external fixation device (Orthofix M-100). On completion of the distraction, x-ray analysis showed that the distracted gap was filled with callus organized into three zones, namely, two sclerotic zones with a central radiolucent zone. These zones became indistinguishable from the adjacent preexisting mandible at 10 weeks after distraction. Histologically, new bone, which was formed by both intramembranous and endochondral ossification, underwent remodeling and resulted in cortical bone by 8 to 10 weeks after completion of distraction.

Animals↗
PubMed1994

Effect on gastric mucus of the proton pump inhibitor leminoprazole and its cytoprotective action against ethanol-induced gastric injury in rats.

The effect of leminoprazole ((+-)-2-[[2-(isobutyl-methylamino)benzyl]sulfinyl]-1H-benzimidazol e, NC-1300-O-3, CAS 104340-86-5), a new compound being developed as an inhibitor of the gastric mucosal proton pump (H+,K(+)-ATPase), on gastric mucus secretion was studied by a biochemical method measuring the gastric mucin content in rats. Oral administration of leminoprazole (30 mg/kg) strongly inhibited the hemorrhagic lesions induced by 60% ethanol containing 0.15 mol/l HCl (acid-ethanol) administered 1 h later. Leminoprazole significantly inhibited the acid-ethanol-induced reduction of the mucin content in the surface mucosa including the mucus gel layer, but no significant effect could be obtained on the reduction of mucin present in the deep layer of the corpus and antral mucosa. Leminoprazole given to rats not treated with acid ethanol accelerated the secretion of deep mucosal mucus and increased significantly the content of soluble mucus which was recovered from the gastric luminal contents to about 200% of control, but failed to produce any significant change in the mucus content present in the surface mucosal and the mucus gel layers. The effect of leminoprazole on gastric mucus secretion might contribute to healing the peptic ulcer diseases and may be involved in the cytoprotective mechanism of this drug.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1993

Experimental study on growth of epiphysial plate: free graft in rabbits.

The growth potential of a free graft of an epiphysial plate was investigated in rabbits. Two epiphysial plate grafts were harvested from each iliac crest. One was grafted to the head (onto bone) and the other to the ear (onto cartilage). Both of the epiphysial plates enlarged to a maximum height of 1.4 cm and became similar to iliac crests. Enchondral ossification was observed up till approximately 28 weeks of age. We conclude that an epiphysial plate has growth potential after free heterotopic transplantation.

Animals↗
PubMed1993

Prefabricated venous flaps: an experimental study in rabbits.

Prefabrication is a method for creating donor flaps by implantation of a nourishing pedicle prior to harvesting the flap. Based on the concept that implantation of a "flow-through" vein results in sufficient vascularisation to support a skin flap, we used a rabbit model to investigate the viability of prefabricated total venous perfusion (TVP) flaps. Prefabrication of an abdominal wall donor site was performed using the left epigastric vein in 25 male New Zealand white rabbits. An 8 x 10 cm skin flap was elevated 1, 2, 3, 4, and 6 weeks after prefabrication (n = 5 per group). A silicone sheet was implanted under the skin flap. The mean survival rate of skin flaps was 24%, 52%, 87%, 83%, 84%, respectively. Results of this study show that reproducible survival of a prefabricated TVP flap can be obtained when the flap is elevated more than 3 weeks after prefabrication.

Abdominal Muscles↗
PubMed1993

Mandibular lengthening by gradual distraction: analysis using accurate skull replicas.

Bone lengthening in the upper and lower extremities by gradual distraction has become an accepted procedure. We have used an extraoral device to lengthen the mandible in four patients with unilateral mandibular hypoplasia. Using an accurate skull replica, the proposed corticotomy line, intended direction of lengthening, and appropriate position for the screws were determined. Following distraction, a significant increase in the dimensions of the affected mandible was obtained in each case. In this series, accurate skull replicas proved very useful for defining the anatomy, for surgical simulation and for pre- and postoperative evaluation.

Adolescent↗
PubMed1993

Experimental study of prefabricated flaps using vein grafts.

Prefabrication of a flap may represent a new alternative, not limited by natural vascular territories, for creating donor sites. Experimental procedures in which an A-V shunt results in sufficient flap neovascularization have been reported. This study was undertaken to investigate how neovascularization from the recipient bed affects survival of this type of flap. An 8-cm x 10-cm prefabricated skin flap, nourished by the left epigastric vein, was constructed in a rabbit abdomen. In half the models, a silicone sheet was placed under the flap, to impede neovascularization from the bed. The flaps of both experimental groups showed excellent viability, and no statistically significant difference in survival rate was recognized. This flap was found to be independent of the vascularity of the underlying bed.

Abdomen↗
PubMed1993

Experience with U-shaped gluteal thigh flap for reconstruction of radionecrosis in the sacral region.

The gluteal thigh flap first reported by Hurwitz in 1980 can provide a large reliable flap for coverage of the sacrogluteal and perineal regions. This flap can be extended quite some way along its axial inferior gluteal vessels, but its width is limited to approximately 10 cm if direct approximation of the donor site defect is required. In this article, we report a U-shaped modification of the gluteal thigh flap for efficient use of the flap in covering a large defect in the sacrogluteal region.

Aged↗
PubMed1993

Effects of the muscarinic receptor agonist carbachol and/or antagonist pirenzepine on gastric mucus secretion in rats.

The effects of the muscarinic agonist carbachol on the secretion and accumulation of gastric mucus glycoprotein (mucin) were examined. Gastric mucin obtained from the soluble mucus, adherent mucus gel, and surface mucosal and deep mucosal layer was isolated and quantified. One hour after the subcutaneous administration of carbachol (0.08-80 micrograms/kg body weight) the deep corpus mucin content had decreased significantly (75% of control), corresponding to an increase (120% of control) in the soluble mucin content with 0.8 microgram/kg of carbachol treatment. These changes were counteracted by 10 mg/kg of pirenzepine (selective M1 antagonist) pretreatment. On a single administration of 10 mg/kg of pirenzepine, deep corpus mucin tended to increase, and soluble mucin decreased significantly (49% of the control). These two drugs failed to cause any significant change in the mucin content of the surface and antral deep mucosa or the adherent mucus gel. The muscarinic agonist and the M1 antagonist are thus shown to accelerate the secretion and accumulation, respectively, of mucin in the deep corpus mucosa. Thus intrinsic M1 receptor may possibly be involved in the secretion of mucin in the gastric deep corpus mucosa.

Animals↗
PubMed1992

Effects of tetragastrin on mucus glycoprotein in rat gastric mucosal protection.

The effects of tetragastrin on mucus glycoprotein (mucin) metabolism and mucosal protection in rat gastric mucosa were investigated. Rats were administered with various doses of tetragastrin (12, 120, or 400 micrograms/kg body weight; s.c.), followed by 50% ethanol-induced gastric injury. Tetragastrin caused a significant increase in mucin content in the corpus mucosa and prevented 50% ethanol-induced gastric mucosal damage in a dose-dependent manner. For assessment of the effects of tetragastrin on the metabolism of gastric mucin in detail, changes in mucin distribution in the three different layers of rat gastric mucosa were examined one hour after single administration of tetragastrin. A significant increase in the mucin content was noted in the mucus gel and surface mucosal layer. Mucin content in the deep mucosa corresponding mainly to the mucus neck cell mucin underwent virtually no change by this treatment. An increase in mucin in the mucus gel and surface mucosa would thus appear due to the administration of tetragastrin and may possibly be related to the protective action of the gastric mucosa against injury. The data demonstrate a possibility that gastrin may have potential for enhancing gastric mucosal protection associated with mucus secretion and/or mucus synthesis on the surface mucosa of rat gastric mucosa.

Animals↗
PubMed1992

A separating method for quantifying mucus glycoprotein localized in the different layer of rat gastric mucosa.

A method was devised for separating rat gastric mucosa into three layers each containing a different mucin species. The mucus gel (first layer) was removed by stirring the gastric mucosa in a solution of phosphate-buffered saline containing 2% N-acetylcysteine. The surface mucosa (second layer), rich in surface mucus cells, was then separated from the deep mucosa (third layer) containing mucus neck cells, by scraping with forceps. The effectiveness of this method was confirmed by light microscopical observation after GOCTS-PCS (dual staining by the galactose oxidase-cold thionin Schiff method and paradoxical concanavalin A method) and AB-PAS staining (dual staining with alcian blue and the periodic acid Schiff method). The fixed specimen of scraped mucus and cell debris was rich in AB-PAS and GOCTS positive mucus, but was hardly stained by PCS, indicating mucus derived from surface mucus cells to have been efficiently recovered from this preparation. The residual mucosa could be stained by PCS but hardly at all by AB-PAS or GOCTS. The lyophilized powder specimens obtained from the three different layers of rat gastric mucosa were used to extract and quantify mucus glycoprotein (mucin). This was done to examine changes in mucin content in the three layers of gastric mucosa one hour following the oral administration of 20% ethanol or 0.35 N hydrochloric acid, both mild irritants. Mucin content was noted to significantly increase in the first layer but hardly at all in the second layer. In the third layer, it decreased significantly by 0.35 N hydrochloric acid, but changed only slightly by 20% ethanol administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Effect of rebamipide on mucus secretion by endogenous prostaglandin-independent mechanism in rat gastric mucosa.

The effect of rebamipide (2-(4-chlorobenzoylamino)-3-[2 (1H)-quinolinon-4-yl]-propionic acid, OPC-12759, CAS 11911-87-6), an anti-ulcer agent developed to enhance defensive factors in the gastric mucosa, on gastric mucus secretion was studied by a newly developed biochemical method to measure the gastric mucus glycoprotein content in rats. 1 h after intraperitoneal administration, rebamipide did not produce a significant change in the intramucosal mucus contents (surface mucosal layer and deep mucosal layers of corpus and antral regions) but significantly increased the content of soluble mucus, which recovered from the gastric contents, to about 160% of the control value. Since rebamipide has been shown to increase the biosynthesis of prostaglandins, indometacin was administered to the rats prior to rebamipide administration to examine whether the increase in prostaglandin biosynthesis contributes to the rebamipide-induced increase in gastric mucus secretion. The increase in the soluble mucus was not altered by the pretreatment with indometacin, thus indicating that rebamipide per se has a potential to increase the gastric mucus secretion by a mechanism that is not mediated by the endogenous prostaglandins. The effect of rebamipide on the gastric mucus secretion might contribute to heal and to prevent the recurrence of peptic ulcer diseases as well as to maintain the homeostasis of the gastric mucosa.

Alanine↗
PubMed1991

Effect of a selective PAF antagonist SM-10661 ((+/-)-cis-3,5-dimethyl-2-(3-pyridyl)thiazolidin-4-one HCl) on experimental disseminated intravascular coagulation (DIC).

Intravenous infusion of endotoxin (0.25 mg/kg/hr for 4 hr) was shown to induce disseminated intravascular coagulation (DIC) in rats, which resulted in hypofibrinogenemia, prolongation of prothrombin (PT) and partial thromboplastin time (PTT), thrombocytopenia, and elevated levels of fibrinogen/fibrin degradation products (FDP). Oral administration (100 mg/kg) of the selective PAF antagonist, SM-10661 ((+/-)-cis-3,5-dimethyl-2-(3-pyridyl)thiazolidin-4-one HCl), counteracted the changes caused by the endotoxin. Intravenous infusion of SM-10661 (6mg/kg bolus 2 min before endotoxin infusion + 6 mg/kg/hr for 4 hr infusion) also counteracted DIC. When suboptimal doses of gabexate mesilate, a synthetic protease inhibitor (3 mg/kg i.p.), and SM-10661 (2 mg/kg bolus + 2 mg/kg/hr for 4 hr infusion) were administered concomitantly, hematological parameters improved. The results suggest that PAF may play a role in the pathogenesis of DIC, and that together with the results already reported for other PAF antagonists, SM-10661 may be useful in the treatment of DIC.

Administration, Oral↗
PubMed1991

A new method of separation and quantitation of mucus glycoprotein in rat gastric mucus gel layer and its application to mucus secretion induced by 16,16-dimethyl PGE2.

A method was established for recovering the mucus gel layer of rat gastric mucosa without damage to underlying surface epithelium. The mucus gel was solubilized by stirring the gastric mucosa in a solution of N-acetylcysteine (NAC), a mucolytic agent. Optimal mucus gel solubilization was possible by treatment with 2% NAC for 5 minutes at room temperature. Mucus glycoprotein was quantitatively extracted and measured from the mucus gel sample obtained by the NAC treatment. This treatment caused no damage to surface epithelial cells, as observed by a light microscope. Besides NAC, pronase solution was also adequate for solubilizing the mucus gel layer without any damage to the surface epithelium. However, extraction and measurement of mucus glycoprotein from the pronase-treated mucus gel sample was not possible due to contamination by high molecular hexose-containing substances which were eluted along with the mucus glycoprotein from the column of Bio-Gel A-1.5m. This NAC method was used to examine changes in mucus glycoprotein content in the mucus gel at one hour following the oral administration of 16,16-dimethyl prostaglandin E2. A significant increase in mucus glycoprotein of the gel was brought about by the prostaglandin treatment. Thus, the present method was suitable for estimating the amount of mucus secreted in to the mucus gel layer.

Animals↗