Biomedical subjects

Y Uchida

Publications and source records attributed to Y Uchida.

At least 307 records · Page 17Linked to original sources

PubMed1995

The induction of cell differentiation and polarity of tracheal epithelium cultured on the amniotic membrane.

We have developed a culture system of guinea pig tracheal epithelial cells using the epithelium-denuded human amnion as a source of basement membrane. Culture medium fluid over the epithelial cells was replaced by air after 7-day immersion culture and thereafter maintained for 2 weeks. Electron microscopical observations revealed that the height of epithelial cells and the ratio of ciliated epithelial cells looked like that of normal guinea pigs epithelium growth in 2 weeks after the air interface, but that no goblet cells could be found. In order to study cell polarity, we measured endothelin-1 levels in the media of apical and basal sides of the epithelial cell monolayer by means of the enzyme-linked immunosorbent assay. The endothelin-1 content of the submucosal side was over 30 times higher than that of the apical side. These findings suggest that ET-1 would be mainly released from airway epithelial cells toward the submucosal side.

Amnion↗

PubMed1995

Developmental changes in response to endothelins and receptor subtypes of isolated rat duodenum.

The response of isolated duodenum to endothelin-1, -3 and IRL 1620 (Suc-[Glu9,Ala11,15]endothelin-1 (8-21)), a selective endothelin ETB receptor agonist, was studied in both neonatal (1-week-old) and adult rats by recording mechanical activity isotonically. Endothelin-1, -3 and IRL 1620 (1-100 nM) elicited sustained contraction of neonatal duodenum, in a concentration-dependent manner, with a potency order of endothelin-1 = endothelin-3 > IRL 1620. The response to endothelin-1 and -3 (10-1000 nM) of adult duodenum was biphasic, i.e., transient relaxation followed by contraction, with a potency order of endothelin-1 > endothelin-3. The contractile response to endothelin-1 of adult but not neonatal duodenum was significantly antagonized by pretreatment with FR139317 (1 microM), an endothelin ETA receptor antagonist. An endothelin ETB receptor antagonist, RES-701-1 (3 microM), weakly antagonized the IRL 1620-induced contraction of neonatal duodenum. However, RES-701-1 (10 microM) did not affect the response to endothelin-1 of either adult or neonatal duodenum. These results indicate that the duodenal response to endothelins changes from a sustained contraction in neonates to a biphasic response in adults. The contractile response to endothelins of neonatal duodenum is suggested to be mediated through endothelin ETB receptors or possibly RES-701-1-resistant ETB receptor subtypes and contraction of adult duodenum through endothelin ETA receptors. The mechanism of the endothelin-induced response of duodenum was also studied.

Aging↗

PubMed1995

The N-terminal portion of growth inhibitory factor is sufficient for biological activity.

To determine its active site, growth inhibitory factor (GIF), a central nervous system-specific metallothionein-like protein, was digested with trypsin followed by Staphylococcus aureus protease V8 digestion. Of 5 peptide fragments separated from trypsin-digested GIF by reverse-phase high pressure liquid chromatography and gel filtration, only GIF1-26 or longer peptides showed growth inhibitory activity on cortical neurons in culture. A shorter peptide, GIF5-23, which was obtained by further digestion of GIF1-26 with V8 protease, also showed growth inhibitory activity. However, a synthetic peptide corresponding to GIF5-23 did not show growth inhibitory activity. Metal-free GIF1-26 prepared by acid treatment showed a similar level of growth inhibitory activity to that of metal-containing GIF1-26, indicating that metal in the peptide does not affect the activity. Treatment of metal-free GIF1-26 with beta-mercaptoethanol resulted in the loss of activity. The CD spectrum of beta-mercaptoethanol-treated metal-free GIF1-26 was different from that of nontreated metal-free GIF1-26. These results indicate that the N-terminal portion of GIF is required for growth inhibitory activity and that folding of the peptide via S-metal bonding is critical for biological activity.

Amino Acid Sequence↗

PubMed1995

Polypoid growth and K-ras codon 12 mutation in colorectal cancer.

BACKGROUND: To clarify genetic changes in colorectal tumorigenesis, K-ras codon 12 point mutations were examined in 101 ordinary colorectal carcinomas and 6 that complicated ulcerative colitis (UC) with special attention to growth patterns. METHODS: The depths of invasion of ordinary carcinoma were submucosa (SMCa) in 39 cases, muscularis propria (PMCa) in 33, and far-advanced in 29. Growth patterns of SMCa and PMCa were classified into three types: polypoid-growth type without central depression (Type 1), polypoid-growth type with central depression (Type 2), and nonpolypoid-growth type. DNA samples were extracted from formalin fixed paraffin embedded sections, and K-ras codon 12 mutations were examined by two-step polymerase chain reaction-restriction fragment length polymorphism. RESULTS: K-ras mutation frequency was higher in Type 1 SMCa than in nonpolypoid SMCa, 56% (9/16) versus 6% (1/17), respectively, and in PMCa, 78% (7/9) versus 23% (3/13), respectively. In 6 UC carcinomas, a K-ras mutation was detected in only one polypoid carcinoma and none were detected in five nonpolypoid carcinomas. CONCLUSIONS: These results and the authors' previous study suggest that nonpolypoid carcinomas may be derived from flat adenomas, whose K-ras mutation incidence also was low, and this pathway is different from a genetic model based on the ordinary adenoma-carcinoma sequence through polypoid adenomas.

Adenoma↗

PubMed1995

Role of eicosanoids but not nitric oxide in the platelet-activating factor-induced increase in vascular permeability in mouse skin.

We investigated the role of endogenous eicosanoids and nitric oxide (NO) in the platelet-activating factor (PAF)-induced increase in vascular permeability in mouse skin. Subcutaneous injection of PAF (45-180 pmol/site) induced a dose-related increase in vascular permeability at the injection site. The vascular permeability induced by PAF (180 pmol/site) was significantly inhibited by pretreatment with an intraperitoneal injection of 1-O-hexadecyl-2-acetyl-sn-glycero-3-phospho (N,N,N-trimethyl) hexanolamine (PAF receptor antagonist) (5 and 25 mg/kg) and indomethacin (cyclooxygenase inhibitor) (10 mg/kg), whereas it was not affected by concurrent intravenous administration of NO synthase inhibitors NG-nitro-L-arginine methyl ester (10 mg/kg) or methylene blue (100 micrograms/kg) nor by topical injection of NG-nitro-L-arginine methyl ester. The inhibitory effect of indomethacin was partially reversed by topical administration of prostaglandin E2. These results suggest that PAF increases venular permeability by activating PAF receptors and that plasma extravasation is potentiated by the release of prostanoids which cause arteriolar dilatation. However, NO is not involved in the effect of PAF in mouse skin.

Amino Acid Oxidoreductases↗

PubMed1995

The effect of body position on a free-floating ball thrombus as observed by transesophageal echocardiography.

Two cases of free-floating left atrial ball thrombi (FLABT) in association with mitral stenosis were observed by transesophageal echocardiography (TEE). Our report describes the relation between body position and thrombi kinetics. Both cases demonstrated similar kinetics. In the supine and right lateral decubitus positions, the thrombi recoiled from and sometimes became entrapped within the mitral valve. In the sitting and left lateral decubitus positions, the thrombi appeared to be nearly fixed and did not contact with the mitral valve. Our results indicate that the latter two positions prevent thrombi disintegration and incarceration into the mitral valve. Finally, TEE is an extremely useful tool for assessing the safest position for individuals with FLABT.

Aged↗

PubMed1995

The kinetics of copper-zinc superoxide dismutase in experimentally induced ischemia-reperfusion injury of the canine jejunum.

In this study, the kinetics of copper-zinc superoxide dismutase (CuZn-SOD) in experimentally induced ischemia-reperfusion injury of the canine jejunum were examined using immunohistochemical procedures, and evaluated as an index for the viability of transplants. A pedicled jejunal graft was subjected to arterial reperfusion after clamping the supplying blood vessels for 30 min. Under nonischemic conditions, some of the goblets in the goblet cells and the mucin covering the surface of the villi were stained positively with luxol fast blue, von Kossa, and immunohistochemistry for CuZn-SOD. Between 5 and 30 min after reperfusion, the appearance of goblets with positive immunoreaction for CuZn-SOD in the intestinal glands and the disappearance of these goblets in the villi were observed in the grafts of animals that received arterial reperfusion after 30 min of clamping of the arteries and veins at room temperature. Thereafter, the former disappeared gradually and the latter returned toward the nonischemic condition. The administration of allopurinol led to a decrease in tissue damage and a significantly higher number of goblets with positive immunoreaction for CuZn-SOD than in untreated animals. Furthermore, the goblets in the intestinal glands showed a negative reaction for CuZn-SOD 5 to 30 min after reperfusion. Preservation at 4 degrees C during ischemia revealed similar results to those observed in the animals given allopurinol. Thus, the distribution and intensity of CuZn-SOD positive goblets seems to be a useful indicator for the evaluation of tissue damage induced by free radicals mediating ischemia-reperfusion injury.

Allopurinol↗

PubMed1995

Alteration in gastric nerve fibers containing gastrin-releasing peptide in relation to the gastrin-producing cell population after truncal vagotomy in a rat model.

The fine structural alteration in the gastric nerve fibers containing gastrin-releasing peptide (GRP) was studied in relation to the dynamics of gastrin-producing cells (G-cells) after truncal vagotomy in a rat model. The circulating gastrin levels were markedly elevated from the 1st day after vagotomy and the number of G-cells with positive immunoreaction for G17 and G34(1-15) was significantly increased in the vagotomized group. On the 3rd day after vagotomy, the G-cells showed conspicuous ultrastructural changes characterized by hypertrophy of the Golgi complexes and increased numbers of secretory granules. The GRP-positive nerve fibers formed a fine network in the gastric wall and were densely distributed in the oxyntic mucosa close to the blood vessels and showing varicosities composed of either small clear or GRP-positive large vesicles containing an electron-dense core. In the oxyntic mucosa of the vagotomized rats, axonal swelling of the nerves occurred on the 3rd day, and a depletion of GRP immunoreactivity was evidenced by a markedly decreased number of large-cored vesicles on the 7th day, when the serum GRP levels were also found to be markedly elevated. These findings indicate that the alteration in gastric nerve fibers containing GRP after truncal vagotomy may be related to hypergastrinemia and antral G-cell hyperplasia in the rat gastric mucosa.

Animals↗

PubMed1995

Subtle increase in leukocyte counts in association with drinking and smoking habits.

Peripheral leukocyte counts were examined in venous blood of more than 800 male workers exposed to toluene, xylenes, a combination of the two, or neither. Information on the social habits of smoking and drinking was obtained in an occupational health interview. The analysis showed that smoking (15 cigarettes/day on average) induced a significant increase (by 7%) in leukocyte counts, and that an additional increase was induced when the drinking habit was coupled with smoking. Drinking alone tended to increase the leukocyte counts but the effect was statistically nonsignificant, possibly because the number of nondrinking smokers was limited. The study stresses the importance of paying attention to smoking and drinking habits when evaluating hematological parameters such as peripheral leukocyte counts in solvent-exposed workers.

Adolescent↗

PubMed1995

Expression rate of cytokine mRNA in the liver of chronic hepatitis C: comparison with chronic hepatitis B.

This study was carried out to test the hypothesis that, in chronic hepatitis (CH), inflammatory processes, including viral replication, host immune response, and hepatocyte destruction, are regulated by a cytokine network in the liver. Expression of the mRNA of the cytokines IL1-beta, IL2, IL4, IL5, IL6, TNF-alpha, and IFN-gamma, the lymphocyte markers CD4 and CD8, and the HLA class I molecule, beta 2-microglobulin (B2MG) in the liver tissue of 20 CH(C) cases and 9 CH(B) patients was investigated by the reverse transcription polymerase chain reaction (RT-PCR) method. TNF-alpha, CD4, and B2MG mRNA were detected in 100% of cases of in both CH(B) and CH(C). The expression rates of IL1-beta, IL2, IL4, IFN-gamma, and CD8 mRNA were 80%, 40%, 25%, 40%, and 80% in CH(C) and 88.9%, 44.5%, 30%, 55.6%, and 100% in CH(B). IL6 mRNA was detected only in CH(B), in 22.2% of cases, IL5 mRNA was not detected in either CH(B) or CH(C). IL2, IL4, and IFN-gamma mRNA were expressed significantly more frequently in patients who had high serum ALT and a high histological activity index (HAI) score. There was no difference in cytokine expression between CH(B) and CH(C), except in IL6, suggesting the existence of a common immunopathogenesis for CH(B) and CH(C). In chronic viral hepatitis, IL1-beta and TNF-alpha appear to play a major role in immune responses and IL2, IL4, and IFN-gamma seem to be associated with increased cytotoxic T cell response.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

Rheological significance of tandem lesions of the coronary artery.

It is not known whether the individual lesions that constitute tandem lesions of the coronary artery are developmentally or rheologically related. Luminal changes and their rheological significance were examined by percutaneous angioscopy in 44 tandem lesions of 21 patients with ischemic heart disease. Angioscopically, individual narrowing of angiographically documented tandem lesions appeared only as a tangentially expressed prominent portion of an atherosclerotic spiral fold. The directions of the fold were counterclockwise in the proximal to middle segments and clockwise in the distal segment of the right coronary artery, clockwise in the proximal to middle segments and counterclockwise in the distal segment of the left anterior descending artery, and counterclockwise in the proximal to middle segments of the left circumflex artery. The bloodstream always ran along the spiral folds in the tandem lesions. The results suggest that angiographically documented tandem coronary lesions are merely a tangential expression of atherosclerotic spiral folds and that they may act to prevent blood turbulence by generating a spiral laminal flow.

Adult↗

PubMed1995

Management of early invasive colorectal cancer. Risk of recurrence and clinical guidelines.

PURPOSE: The purpose of this study was the evaluation of various factors in the formulation of guidelines for treatment of early invasive colorectal cancer, in which malignant cells extend through the muscularis mucosa into the submucosa but do not deeply invade the muscularis propria. METHOD: A total of 182 patients were followed for at least five years or until death, with early invasive cancer diagnosed between 1982 and 1989. Patients were grouped according to the level of invasion, as follows: 64 patients with slight carcinoma invasion of the muscularis mucosa (200-300 microns; sm1), 82 with intermediate invasion (sm2), and 36 with carcinoma invasion extending to the inner surface of the muscularis propria (sm3). RESULT: The configuration, diameter, and histologic grade of adenocarcinoma and lymphovascular invasion were correlated with level of invasion. After endoscopic polypectomy or local resection, 4 patients showed local recurrence and 13 patients showed lymph node metastasis. None of these 17 patients had sm1 disease. The level of invasion, configuration, and location were significant risk factors for development of lymph node metastasis or local recurrence (P < 0.05), but lymphovascular invasion, histologic grade, and diameter were not risk factors. CONCLUSIONS: Preoperative assessment of the level of invasion using this classification, in which the submucosa is divided into three depths, may decrease the incidence of unnecessary surgery for sessile polyps. Assessment according to the level of invasion is useful in the formulation of appropriate guidelines for the treatment of early invasive cancer.

Adenocarcinoma↗

PubMed1995

Angioscopic detection of residual pulmonary thrombi in the differential diagnosis of pulmonary embolism.

Definite diagnosis of pulmonary embolism (PE) by conventional methods such as angiography is frequently difficult. If residual thromboemboli incorporated into the pulmonary arterial wall or in the distal small segments are visible, differential diagnosis of PE versus primary pulmonary hypertension (PPH) can be made without open-chest pulmonary biopsy. Six patients suspected of having acute PE, 6 suspected of having chronic PE, and 4 with PPH diagnosed by pulmonary biopsy underwent percutaneous pulmonary angioscopy. In patients suspected of having PE, globular and mural thromboemboli were detected by both angioscopy and angiography in 4 and 1 patients, respectively. By angioscopy, emboli incorporated into the arterial wall were detected in 7 and microemboli obstructing the distal small segments were detected in 6. However, these emboli were detected by angiography in none. In patients with PPH, no embolus was detected by angioscopy and angiography. Angioscopically, however, stenoses were observed in the distal small segments in all patients. The results indicate that residual pulmonary thromboemboli in PE and stenoses of distal pulmonary arteries in PPH are detectable by percutaneous angioscopy, and therefore this method is feasible for differential diagnosis of PE.

Acute Disease↗

PubMed1995

Angiogenic therapy of acute myocardial infarction by intrapericardial injection of basic fibroblast growth factor and heparin sulfate: an experimental study.

To examine whether angiogenesis and myocardial salvage occur, 30 micrograms basic fibroblast growth factor (bFGF) and 3 mg heparin sulfate (HS) were injected through the right atrium into the pericardial cavity by a thin needle-tipped catheter in a canine model of acute myocardial infarction. One month later infarcted weight/left ventricle weight was 24% +/- 5.2%, 25% +/- 4.0%, 18% +/- 2.4%, and 10% +/- 1.8% (mean + SE) in saline solution, HS, bFGF alone, and bFGF plus HS groups, respectively. Vascular number in the infarcted area of the outer layer was 13 +/- 3.3, 20 +/- 2.2, 47 +/- 8.3, and 136 +/- 26.3/200 x 200 microns2 in saline solution, HS, bFGF alone, and bFGF plus HS groups, respectively. Thus the vascular number was the largest in the bFGF plus HS group. The vascular number was larger in the subepicardial than in the subendocardial infarcted areas. Vessels directed from the epicardium toward the subepicardial infarcted area were also observed. The transcatheter intrapericardial injection of bFGF plus HS caused angiogenesis and myocardial salvage. This method might bring about a selective therapeutic and preventive modality of myocardial infarction irrespective of coronary anatomy and contraindications for coronary interventions and surgery.

Animals↗

PubMed1995

Observation of atherosclerotic lesions by an intravascular microscope in patients with arteriosclerosis obliterans.

The magnification power of conventional fiberscopes for intravascular use is up to x30, and therefore they are not feasible for observation of fine structures of vascular changes. We devised a microscope that enables percutaneous transluminal observation of the vascular luminal changes of cellular order. Thus we examined its feasibility in patients. The microscope was 8F in diameter with a rod lens inside, and its magnification power was from x150 to x350. The microscope was introduced into the iliac or femoral artery for observation of vascular lesions during angioplasty in seven patients with arteriosclerosis obliterans. With the aid of vital staining individually damaged endothelial cells, fibrin threads, foam cells, collagen, elastic fibers, and structure of microthrombi were discriminated clearly. The results indicate that structures of human vascular lesions of cellular order can be observed percutaneously by the intravascular microscope.

Aged↗

PubMed1995

Prediction of acute coronary syndromes by percutaneous coronary angioscopy in patients with stable angina.

To pinpoint the link between plaque characteristics and acute coronary syndromes, we performed a 12-month prospective follow-up study in 157 patients with stable angina pectoris in whom regular coronary plaques were observed by percutaneous coronary angioscopy. Acute coronary syndromes occurred more frequently in patients with yellow plaque than in those with white plaques (11 of 39 vs 4 of 118; p = 0.00021). Moreover, the syndromes occurred more frequently in patients with glistening yellow plaques than in those with nonglistening yellow plaques (9 of 13 vs 2 of 26; p = 0.00026). Thrombus arising from the ruptured identical plaques was confirmed by angioscopy as the culprit lesion of the syndromes. The results indicate that acute coronary syndromes occur frequently and in a short time in patients with glistening yellow plaques and that angioscopy but not angiography is feasible for prediction of the syndromes.

Acute Disease↗

PubMed1995

Immunohistochemistry of gap junctions in normal and diseased gastric mucosa of humans.

BACKGROUND & AIMS: Intercellular communication through gap junctions has been proposed to be an important mechanism for the maintenance of tissue homeostasis. However, few studies have considered the role of gap junctions in gastric mucosa. The purpose of this study was to evaluate the distribution of gap junction-specific proteins in normal and diseased gastric mucosa of humans. METHODS: Biopsy specimens were obtained endoscopically. Immunohistochemical staining was performed by standard immunoperoxidase techniques using an anti-connexin 32 monoclonal antibody. RESULTS: In normal gastric mucosa, connexin 32 was present chiefly in the foveolar cells and in a decreasing staining gradient extending down to the necks of the glands. Connexin 32 also was observed in the epithelial cells of atrophic mucosa in a pattern similar to that observed in normal controls. Conversely, the majority of the foveolar cells adjacent to erosions had reduced or absent staining. Connexin 32 also was reduced significantly or absent from metaplastic epithelial cells. No malignant cells from patients with carcinoma contained detectable connexin 32. CONCLUSIONS: Intercellular communication likely is impaired in precancerous or paracancerous lesions of the stomach. Abnormal intercellular communication thus may play an important role in the progression from mucosal injury to intestinal metaplasia and/or gastric carcinoma.

Adult↗

PubMed1995

Myocardial microdialysis of salicylic acid to detect hydroxyl radical generation during ischemia.

We examined in vivo monitoring of hydroxyl radical (.OH) generation during myocardial ischemia for 30 min by occluding the left anterior descending (LAD) in dog heart using a microdialysis technique. The hydroxyl radical reacts with salicylate and generates 2,3- and 2,5-dihydroxybenzoic acids (DHBA) which can be measured electrochemically in picomole quantity by a high pressure liquid chromatography-electrochemical (HPLC-EC) procedure. When the premature ventricular contraction (PVC) occurred at almost 25 sec intervals, marked elevation of the levels of 2,3- and 2,5-DHBA was observed in the heart dialysate of 30-min ischemia. This study demonstrated the generation of .OH in the canine heart subjected to 30-min ischemic insult.

Animals↗