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Biomedical subjects

K Ohmori

Publications and source records attributed to K Ohmori.

At least 109 records · Page 6Linked to original sources
PubMed2000

Effects of zaldaride maleate, an antidiarrheal compound, on intracellular Ca2+-mediated short-circuit current response in the rat colonic mucosa.

The effect of zaldaride maleate (ZAL) on intracellular Ca2+-mediated short-circuit current (Isc) response in rat colonic mucosa was investigated. The Isc response to acetylcholine was partially reduced by the neuronal blocker tetrodotoxin. The tetrodotoxin-sensitive Isc response to acetylcholine was inhibited by ZAL. The tetrodotoxin-insensitive effect, which indicates direct stimulation of acetylcholine in colonic mucosa, was not affected by ZAL. The Isc response to the Ca2+ ionophore A23187 was reduced by ZAL in the presence of tetrodotoxin. These results suggest that ZAL reduces colonic ion secretion by inhibiting a tetrodotoxin-sensitive neuronal pathway and an intracellular Ca2+ pathway in epithelium.

Acetylcholine↗
PubMed2000

Effects of valsartan on angiotensin II-induced migration of human coronary artery smooth muscle cells.

The migration as well as proliferation of coronary artery medial smooth muscle cells (SMC) into the intima is proposed to be an important process of intimal thickening in coronary atherosclerosis. In the current study, we examined the effects of the angiotensin type 1 receptor antagonist valsartan on angiotensin II (Ang II)-induced migration of cultured human coronary artery SMC using Boyden's chamber methods. Ang II significantly stimulated human coronary artery SMC migration in a concentration-dependent manner between 10(-6) and 10(-8) mol/l when cells of passage 4 to 6 were used. However, the migration response to Ang II was moderately decreased in cells of passage 10 to 12, and was markedly decreased in cells of passage 15 to 17, compared to that of passage 4 to 6. Ang II-induced migration was blocked by the Ang II type 1 (AT1) receptor antagonist valsartan in a concentration-dependent manner. By contrast, the Ang II type 2 (AT2) receptor antagonist PD 123319 did not affect Ang II-induced migration. Ang II modestly increased the cell number of human coronary artery SMC after a 24-h incubation. This increase in cell numbers was also clearly blocked by valsartan, but not by PD 123319. These results indicate that Ang II stimulates migration as well as proliferation via AT1 receptors in human coronary artery SMC when cells of passage 4 to 6 are used. Valsartan may prevent the progression of coronary atherosclerosis through an inhibition of Ang II-induced migration and proliferation in these cells, although in vivo evidence is lacking.

Angiotensin II↗
PubMed2000

Crouzon syndrome with acanthosis nigricans: case report and mutational analysis.

OBJECTIVE: To describe the 22nd case of Crouzan syndrome with acanthosis nigricans, a hyperkeratotic skin disorder with hyperpigmentation. METHODS: DNA analysis and sequencing of the FGFR3 gene were performed. RESULTS: The 13-year-old Japanese boy described here also had dyspnea, facial palsy, sensorineural hearing loss, and skeletal and mental retardation. Examination of a skin biopsy specimen revealed the typical findings of acanthosis nigricans. Genetic analysis revealed the Ala391Glu mutation in one FGFR3 gene. CONCLUSIONS: Crouzon syndrome with acanthosis nigricans is a distinct clinical entity different from classic Crouzon syndrome.

Acanthosis Nigricans↗
PubMed2000

Significance of serum type IV collagenolytic activities and gelatinase levels for detection of metastasis in murine RCT sarcoma.

We investigated the usefulness of serum type IV collagenolytic activities and gelatinase levels as diagnostic markers of metastasis in the animal model of spontaneous lung metastasis by FITC-labeled type IV collagen degradation assay and zymographic analyses. High-metastatic RCT(+) and low-metastatic RCT(-) clones were used in the present study. The mean serum type IV collagenolytic activity in the RCT(+) group started to increase from two weeks after hind limb amputation, and was 0.45 and 1.29 unit/ml at three and four weeks. These values were significantly higher than those in the control group (p < 0.01 at three weeks; p < 0.001 at four weeks). A correlation between the number of lung nodules and serum type IV collagenolytic activities in the RCT(+) group was found (r = 0.89, p < 0.001). Zymographic analyses indicated that 105-kD gelatinolytic activities of the RCT(+) group were higher than those of the RCT(-) group at three and four weeks. Thus, type IV collagenolytic activities and serum gelatinase levels might be valuable markers for the detection of metastasis.

Animals↗
PubMed2000

[Newly developed technology for intravenous contrast echocardiography].

Until now we have not been able to employ a contrast enhancer for ultrasonic echocardiography at the everyday clinical level because the agent itself, composed of microbubbles, was too easily dispersed or even destroyed by several factors. However, contrast echocardiography has made a great leap forward with major developments on two fronts; the application of some new intravenous contrast enhancers, and newly developed machine technology permitting second harmonic imaging, intermittent or triggered imaging, pulse inversion harmonic imaging, and so on. New contrast enhancing agents are proving durability enough to permit greatly enhanced imaging for more than several minutes after injection. Recent new echocontrast specific imaging allows real-time visualizing of myocardial perfusion and assessment of myocardial function.

Contrast Media↗
PubMed2000

Type 4 phosphodiesterase inhibitors attenuate respiratory syncytial virus-induced airway hyper-responsiveness and lung eosinophilia.

Viral respiratory infections are considered one of the triggers of exacerbations of asthma. In a model of virus-induced airway hyper-responsiveness (AHR), mice infected with human respiratory syncytial virus (RSV) were shown to develop AHR accompanied by lung eosinophilia. Inhibitors of cyclic nucleotide phosphodiesterase (PDE) have been shown to affect airway responsiveness and pulmonary allergic inflammation. In this study, we assessed the effects of type 4 PDE (PDE4) inhibitors on AHR following RSV infection and compared them with a PDE3 inhibitor. In mice infected by intranasal inoculation of RSV, treatment with the PDE4 inhibitor rolipram or Ro-20-1724 reduced both AHR and the eosinophil infiltration of the airways. In contrast, the PDE3 inhibitor, milrinone, did not influence airway responsiveness or eosinophilic inflammation. These results demonstrate that PDE4 inhibitors can modulate RSV-induced AHR and lung eosinophilia and indicate that they have a potential role in treating exacerbations of asthma triggered by viral infection.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed2000

[A case report of treatment for tracheal fistula after radical esophagectomy].

We report our experience of the treatment of a 60-year-old man with upper tracheal fistula which developed on the 11th day after radical surgery for esophageal cancer. Primary treatment to close the fistula was unsuccessful, resulting in the involvement of empyema due to infection. Controlled ventilation with T-tube and drainage through a chest tube for 2 months lead to depuration of the thoracic cavity. As a strategy for secondary closure of the fistula, fenestration was performed on the 87th day postoperatively. The patient's overall condition improved thereafter and closure was being considered. However, the patient died on the 116th day postoperatively due to supervenient aspiration pneumonia. Thus, long-term controlled ventilation with a T-tube was beneficial for the treatment of central airway injury.

Esophageal Neoplasms↗
PubMed2000

[Clinical evaluation of urinary basic fetoprotein and the BTA test for detection of bladder cancer].

We compared the results of urinary basic fetoprotein (BFP) and the BTA test with those of urinary cytology in patients with bladder cancer. We also analyzed the urinary BFP and the BTA test results in patients with benign diseases and postoperative bladder cancer with no evidence of recurrence. The cutoff value for urinary BFP was set at 10 ng/ml. Classes 4 and 5 according to urinary cytology were defined as positive. The sensitivity of urinary BFP for Ta, 1 bladder cancer was significantly higher than that of urinary cytology (p < 0.05). The urinary cytology positive rate for Ta, 1 bladder cancer improved when combined with urinary BFP and the BTA test. The urinary BFP positive rate for benign diseases was significantly higher in patients with pyuria than in patients without pyuria (p < 0.05). The BTA test positive rate for benign diseases was higher in patients with pyuria than in patients without pyuria. The urinary BFP and the BTA test positive rates for postoperative bladder cancer with no evidence of recurrence was significantly higher in patients with urinary diversion than in patients without urinary diversion (BFP: p < 0.01, BTA: p < 0.05).

Adult↗
PubMed1999

Association between an aggrecan gene polymorphism and lumbar disc degeneration.

STUDY DESIGN: A case-control study using magnetic resonance imaging findings and a polymerase chain reaction assay to investigate the association between aggrecan gene polymorphism and lumbar disc degeneration. OBJECTIVE: To analyze whether the aggrecan gene polymorphism is related to lumbar disc disease in young women. SUMMARY OF BACKGROUND DATA: It has been suggested that a genetic factor or familial predisposition contributes to the development of lumbar disc herniation. However, the precise genetic component related to disc disease remains unclear. Recently, a polymorphism has been identified in the region of the human aggrecan gene. The expressed variable numbers of tandem repeat polymorphism occur in the highly conserved repeat region. METHODS: The participants were 64 young women with or without low back problems. Magnetic resonance imaging was used to evaluate the degeneration and herniation of the intervertebral disc. Genomic deoxyribonucleic acid was extracted from all participants. A polymerase chain reaction assay was carried out to detect the alleles of the aggrecan gene. The association of intervertebral disc degeneration and herniation with the distribution of the aggrecan gene alleles was analyzed. RESULTS: Findings showed an overrepresentation of alleles with small numbers of repeats in subjects with multilevel disc degeneration, thus indicating a significant distribution difference. There also was a significant difference between the distribution of alleles and the severity of disc degeneration. No significant association was found between any of the alleles either in number or type of disc herniation. CONCLUSIONS: The current study showed that multilevel and severe disc degeneration was present in the participants with shorter variable numbers of tandem repeat length of the aggrecan gene. This suggests that subjects with shorter variable numbers of tandem repeat length of the aggrecan gene have a risk of having multilevel disc degeneration develop at an early age.

Adult↗
PubMed1999

Quantitative evaluation of left ventricular regional wall motion using a real-time wall thickness curve system with two-dimensional echocardiography.

The real-time wall thickness curve system was newly developed for recording left ventricular (LV) wall thickening (WT) on a 2-dimensional echocardiogram recorded in an arbitrary direction because of the scarcity of quantitative data on wall motion change during dobutamine-induced ischemia. This study tested the feasibility of this system for quantitative evaluation of wall motion. In normal subjects, accuracy and reproducibility of measurements were evaluated by comparison with measurements on a conventional M-mode echocardiogram and examination of inter- and intraobserver variability. In 28 patients with coronary artery disease, percent systolic wall thickening (%WT) was measured during dobutamine infusion in incremental doses of 6 microg/kg/min, from 6 to 30 microg/kg/min. Percent change in %WT by dobutamine was compared with percent coronary stenosis derived from quantitative coronary angiography. Analysis of the mean difference and 95% confidence intervals demonstrated good accuracy and reproducibility: 0.0 mm and intervals of -0.5 to 0.5 mm in diastolic wall thickening of LV posterior wall (PW) between both methods, -1% and -4% to 2% in %WT of IVS and LVPW between both observers, and -1% and -3% to 2% in that between both measurements. During dobutamine infusion, the percent change in %WT was significantly correlated with percent stenosis (r = 0.75, p<0.0001). The WT curve system enabled us to assess regional wall function as %WT and was available for quantitative observation of wall motion change during pharmacologic intervention. This system may reduce the effects of heart movement and may be of great clinical benefit in evaluating regional wall function.

Aged↗
PubMed1999

Feasibility of right ventricular myocardial opacification by contrast echocardiography and comparison with left ventricular intensity.

To demonstrate the feasibility and quantify the intensity of right ventricular (RV) myocardial opacification by myocardial contrast echocardiography (MCE), we analyzed MCE produced by intravenous injection of 0.15 ml/kg of QW7437 in 8 closed-chest dogs. MCE could produce visual opacification of the RV wall similar in time course to that of the left ventricular wall, and the data supported the potential role of MCE in evaluating RV hypertrophy, contraction, and perfusion abnormalities.

Animals↗
PubMed1999

Effect of batroxobin on spontaneous echo contrast and hemorheology in left atrial appendage in atrial fibrillation assessed by transesophageal echocardiograpy.

Controversy exists regarding the effect of defibrination on spontaneous echo contrast and flow dynamics in left atrial appendage (LAA) in atrial fibrillation. We aimed to investigate the effect of batroxobin, which decreases plasma fibrinogen level, on the echo intensity of spontaneous echo contrast in LAA. In 36 patients with atrial fibrillation (duration 7 +/- 4 years), transesophageal echocardiography was performed at baseline and 24 hours after batroxobin administration (0.2 U/kg). At the orifice of the LAA, integrated backscatter of echo contrast and peak velocity of LAA emptying flow were measured. Plasma fibrinogen and whole blood viscosity were also measured. Fibrinogen and viscosity were significantly lower after batroxobin administration (96 +/-38 mg/dl and 4.35 +/- 0.56 cp) than those at baseline (320 +/- 61 mg/dl and 4.71 +/- 0.61 cp, both p <0.001). A significant positive correlation between changes in plasma fibrinogen and whole blood viscosity (r = 0.49, p = 0.002) was shown. The integrated backscatter significantly decreased from 14 +/- 3 to 12 +/- 3 decibels after batroxobin (p <0.001), and the changes in integrated backscatter and plasma fibrinogen was significantly correlated. Therefore, batroxobin administration improved blood rheology and decreased blood cell aggregation, which are effective in preventing left atrial thrombus formation.

Aged↗
PubMed1999

Latent structures underlying schizophrenic symptoms: a five-dimensional model.

Latent structures of schizophrenic phenomenology were examined over the course of the illness in 100 newly-admitted patients. We compared the results of a confirmatory factor analysis (CFA) on ten competing models that had between zero and five dimensions using data assessed by the Positive and Negative Syndrome Scale (PANSS) at both the acute and chronic phases of the disease. The present findings did not support the two-dimensional construct of positive and negative symptoms in either the acute or the chronic phase of the illness. In the acute phase, a three- (positive, negative, and relational dimensions), four- (positive, negative, disorganization, and relational dimensions), and five-dimensional model (positive, negative, disorganization, excitement, and relational dimensions) fit the data relatively well. In contrast, in the chronic stable phase, only the five-dimensional model adequately fits the data. The present findings suggest that further investigation of the validity of the five-dimensional model over the course of the illness is necessary.

Acute Disease↗
PubMed1999

Quantitative analysis of myocardial response to dobutamine by measurement of left ventricular wall motion using omnidirectional M-mode echocardiography.

Although dobutamine stress echocardiography is important for assessing cardiac ischemia and viability, analysis of wall motion is qualitatively performed. We quantitatively evaluated left ventricular wall motion using a newly developed omnidirectional M-mode echocardiography that can depict the M-mode at the site of region of interest on the 2-dimensional image in real time, and established its usefulness for analyzing the myocardial response to dobutamine infusion. Dobutamine stress echocardiography with omnidirectional M-mode was performed in 57 patients with coronary lesions. In 38 of these patients, exercise stress single-photon emission computed tomographic thallium scintigraphy (Tl-201 SPECT) was performed. Endocardial excursion of 103 regions was measured from omnidirectional M-mode at baseline, low-dose (6 microg/kg/min), and at peak dose (30 microg/kg/min) dobutamine. A decrease and increase in wall excursion was scored (from -3 to 3) for a changes of every 2 mm, and a quantitative wall motion score (QWMS) was calculated as a summation of the scores from baseline to low dose and from low to peak doses. Quantitative coronary stenosis score (QCSS) was calculated as a summation of stenotic and collateral scores. The stenosis scores were graded as: 1 = 0% to 50%, 2 = 50% to 75%, 3 = 75% to 90%, 4 = 90% to 95%, 5 = 95% to 100%; collateral scores were graded as: -1 = poor collateral, -2 = good collateral. Based on the QWMS at each dose of dobutamine, the serial changes in wall motion were divided into 4 groups: augmented, biphasic, no change, and worsening. The QCSS was clearly different among these groups. QWMS was significantly correlated with QCSS (r = 0.657, p <0.001). The incidence of redistribution in Tl-201 SPECT was high in the region with low score of QWMS. In conclusion, omnidirectional M-mode is useful for quantitatively determining the grade of cardiac ischemia by assessing the serial change of ventricular wall motion during dobutamine infusion.

Adrenergic beta-Agonists↗
PubMed1999

Mechanism of Ret activation by a mutation at aspartic acid 631 identified in sporadic pheochromocytoma.

Mutations at aspartic acid 631 in Ret were reported in sporadic pheochromocytoma and medullary thyroid carcinoma. We replaced this aspartic acid with four other amino acids including tyrosine, glycine, asparagine, and alanine and investigated the transforming activity of these mutant cDNAs. Among them, RET cDNA with a mutation of aspartic acid to tyrosine (D631Y) that was reported in sporadic pheochromocytoma showed high transforming activity. The D631Y mutation activated Ret by inducing its disulfide-linked dimerization in the transfectant as observed for multiple endocrine neoplasia (MEN) 2A mutations at cysteine 609, 611, 618, 620, 630, or 634. Further mutation analysis suggested that cysteine 630 or 634 could be involved in the disulfide-linked Ret dimerization induced by the D631Y mutation.

3T3 Cells↗
PubMed1999

Regulation of selectin binding activity by cyclization of sialic acid moiety of carbohydrate ligands on human leukocytes.

We provide here evidence that supports the occurrence of a biologically dormant form of selectin ligand carbohydrate, the sialyl 6-sulfo Lewis X containing modified sialic acid, in human leukocytes. The modification of sialic acid involves first de-N-acetylation of sialic acid moiety through ubiquitous de-N-acetylation/re-N-acetylation cycle, followed by the dehydrative cyclization of de-N-acetyl sialic acid to form "cyclic sialic acid." The enzyme involved in the dehydration of de-N-acetyl sialic acid is a calcium-dependent enzyme having neutral-alkaline pH optimum. De-N-acetyl sialyl 6-sulfo Lewis X retained selectin binding activity as well as parental sialyl 6-sulfo Lewis X, but cyclic sialyl 6-sulfo Lewis X was devoid of selectin binding activity. Sialyl 6-sulfo Lewis X carrying the cyclic sialic acid is specifically recognized by the newly generated mAb, G159. The determinant was distributed widely among normal human leukocytes, especially on monocytes and subsets of lymphocytes including NK cells, helper memory T cells, Tcr-gammadelta T cells, and a part of B cells. The determinant was detected also on several cultured lymphocytic leukemia cell lines and O-tetradecanoylphorbol 13-acetate-activated lymphoid cells. Cyclic sialyl 6-sulfo Lewis X is efficiently formed by the action of the partly membrane-bound calcium-dependent enzyme, tentatively called "sialic acid cyclase," and a possible physiological significance of this reaction could be a rapid inactivation of selectin binding activity at the cell surface. Conversely, the accumulated intracellular cyclic sialyl 6-sulfo Lewis X determinant may function as a dormant pool of selectin ligands, which, on appropriate stimulation, is hydrolyzed and becomes active in selectin-dependent cell adhesion.

Antigens, CD↗