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Biomedical subjects

K Takeuchi

Publications and source records attributed to K Takeuchi.

At least 361 records · Page 20Linked to original sources
PubMed1999

Exercise four hour redistribution thallium-201 single photon emission computed tomography and exercise induced ST segment elevation in detecting the viable myocardium in patients with acute myocardial infarction.

OBJECTIVE: To investigate the specificity and sensitivity of the combination of redistribution in exercise thallium-201 single photon emission computed tomography (SPECT) and exercise induced ST elevation for detecting the viable myocardium in patients with acute myocardial infarction. DESIGN: 37 patients were studied within seven weeks of onset of Q wave myocardial infarction (anterior in 22, inferior in 15). All patients underwent exercise four hour redistribution thallium-201 SPECT and positron emission tomography using fluorine-18-fluorodeoxyglucose (FDG) and nitrogen-13 ammonia under fasting conditions. RESULTS: Sixteen patients showed exercise induced ST elevation >/= 1.5 mm, and 15 of these had increased FDG uptake in the infarct region. Eleven of 16 patients (10 of 11 patients with anterior infarctions) with irreversible thallium-201 defects and increased FDG uptake showed exercise induced ST elevation. The sensitivity, specificity, and predictive accuracy of redistribution, exercise induced ST segment elevation, or both for detecting increased FDG uptake were 82%, 75%, and 67% (94%, 75%, and 91% for anterior infarctions), respectively. CONCLUSIONS: In patients with acute Q wave myocardial infarction, the combination of redistribution in exercise thallium-201 SPECT and exercise induced ST elevation can detect the viable myocardium in the infarct region with high sensitivity and specificity, especially in patients with anterior infarctions.

Adult↗
PubMed1999

Tumor-associated macrophage infiltration in pulmonary adenocarcinoma: association with angiogenesis and poor prognosis.

The relation between tumor-associated macrophage (TAM) density and the density of microvessels was investigated in specimens from 113 patients with pulmonary adenocarcinoma, as was the influence of TAM density on prognosis. The rank correlation test revealed a significant relation between TAM density and microvessel density (y = 14.418 + 0.863x, r = 0.454, p > 0.0001). A significant difference in patient survival rate was detected between tumors with a TAM density defined as high and those with a TAM density defined as low (p < 0.01). Multivariate analysis also showed that TAM density was significantly related to survival (p < 0.05). These data indicate that TAM infiltration may contribute to tumor angiogenesis, and that TAM density is a useful prognostic marker in pulmonary adenocarcinoma.

Adenocarcinoma↗
PubMed1999

Idiopathic clitoral hypertrophy.

We report a case of clitoral hypertrophy of unknown origin. A 3-year-old girl showed clitoral hypertrophy at birth. Biochemical analysis of peripheral blood and endocrinological examinations were normal. Other virilizing symptoms were not recognized. Clitoroplasty was carried out, and the clitoris has not enlarged 20 months after the operation. Her mother was administered cefotiam and terbutaline (beta-stimulant) during pregnancy because of threatened abortion. No virilizing agents such as progesterone were used during pregnancy.

Abortion, Threatened↗
PubMed1999

Effects of candesartan and cilazapril on rats with myocardial infarction assessed by echocardiography.

The purpose of this study was to compare the angiotensin II type 1 receptor antagonist candesartan cilexitil (candesartan) and the angiotensin-converting enzyme inhibitor cilazapril on cardiac function, assessed by Doppler echocardiography and cardiac gene expression associated with cardiac remodeling, in rats with myocardial infarction. Candesartan or cilazapril was administered after myocardial infarction. At 1 and 4 weeks after myocardial infarction, cardiac function and mRNA expression in noninfarcted myocardium were analyzed. Candesartan and cilazapril equally prevented increases in hypertrophy in noninfarcted myocardium, left ventricular dilatation, and ejection fraction at 4 weeks. The E-wave/A-wave velocity ratio and the rate of E-wave deceleration, measures of diastolic function, increased to 9.2+/-0.6 and 26.3+/-2. 6 m/s2 at 1 week after myocardial infarction. Candesartan and cilazapril, administered at a dose of 1 mg/kg per day, prevented increases in E-wave/A-wave velocity ratio and E-wave deceleration at 1 and 4 weeks. Candesartan and cilazapril significantly suppressed increased mRNA expression of beta-myosin heavy chain, alpha-skeletal actin, and atrial natriuretic peptide in noninfarcted ventricle at 1 and 4 weeks and expression of collagen I and III at 4 weeks to a similar extent. When given at a dose of 10 mg/kg per day, both candesartan and cilazapril prevented cardiac dysfunction and gene expression to the same extent as when given at 1 mg/kg per day. In conclusion, Doppler echocardiography showed that candesartan and cilazapril equally improved systolic and diastolic function and that ventricular remodeling accompanied modulation of cardiac gene expression.

Angiotensin Receptor Antagonists↗
PubMed1999

Effect of biochemical components on rheologic properties of nasal mucus in chronic sinusitis.

The effect of biochemical components on the viscoelasticity of nasal mucus from 24 patients with chronic sinusitis (CS) was investigated by multiple stepwise regression analysis. The dynamic viscosity (eta') and the elastic modulus (G') of nasal mucus were determined with an oscillating sphere magnetic rheometer at oscillatory frequencies of 1 and 10 Hz. The eta' and G' values of mucus determined at 1 Hz were 1.6 +/- 1.5 Pa/s and 31.8 +/- 31.0 Pa, respectively, and these values were much higher than optimal viscoelasticity for mucociliary transport. The concentrations of fucose, N-acetyl neuraminic acid, albumin, IgG, secretory-IgA, and lysozyme were measured in the same mucus samples. The multiple regression analysis showed that the concentration of fucose, a marker of mucous glycoproteins, was the most important determinant of eta' and G'. The analysis also revealed that the level of IgG was the next important determinant. The coefficients of multiple determination for fucose and IgG were 0.732 and 0.733 when the response variables were eta' and G', respectively. The results indicate that locally produced mucous glycoproteins may largely contribute to the high viscoelasticity of nasal mucus in CS.

Adolescent↗
PubMed1999

Effect of dextran derivatives on arginine amidase activities released from isolated rabbit arteries.

In the present research we examined the levels and types of arginine amidase activities that were released from isolated rabbit arteries treated with heparin or chondroitin sulfate. Heparin accelerated the release of arginine amidase activity from the isolated rabbit ear artery, the induction was not significant; a slight increase in activity was observed in the level of arginine amidase released from isolated rabbit aorta, but no significant difference was observed. On the other hand, it was revealed that the addition of chondroitin sulfate, accelerated this release from isolated rabbit ear artery with 5% significant differences. After the addition of chondroitin sulfate, the arginine amidase activity released from isolated rabbit arteries was analyzed using various affinity adsorption methods. This analysis confirmed the presence of two types of fibrinolytic enzymes: plasminogen/plasmin activity and plasminogen activators, but no thrombin was detected.

Animals↗
PubMed1999

[Characterization of the facilitatory modulation of adrenergic neurotransmission via prejunctional purinoceptors in rabbit ear artery].

The purinergic modulation of the release of norepinephrine (NE) from sympathetic nerves in the rabbit ear artery was investigated. Methoxamine, an alpha 1-adrenoceptor agonist, enhanced the NE-release by electrical stimulation (ES) and released large amounts of adenyl purines (ATP, ADP, AMP and adenosine) from the endothelium. Both actions of methoxamine were blocked by prazosin. In addition, the enhancement of the NE-release by methoxamine was abolished by 8-sulfophenyl theophylline (8SPT), a P1-Purinoceptor antagonist. These findings indicated that the endogenous purines and purinoceptors participate in the facilitation of NE-release by alpha 1-adrenoceptor stimulation. P1-Purinoceptor agonists, such as adenosine and 2-chloroadenosine, and P2-purinoceptor agonists, such as ATP and beta,gamma-methylene ATP (beta gamma-mATP), enhanced the ES-evoked NE-release. This enhancement was antagonized not only by the P1-purinoceptor antagonist, 8SPT, but also by the P2-purinoceptor desensitizing agent, alpha,beta-methylene ATP. A phosphodiesterase inhibitor, Ro20-1724 potentiates the enhancement of NE-release by beta gamma-mATP. On the other hand, an adenylate cyclase inhibitor, SQ22536, inhibited the enhancement of NE-release by beta gamma-mATP. These findings suggested that prejunctional facilitatory purinoceptors exist on the adrenergic nerves of the rabbit ear artery. This receptor may be coupled to adenylate cyclase and is different from well-known P1 and P2 purinoceptors. In the rabbit ear artery, adrenergic neurotransmission may be regulated by endogenous ATP and its metabolites via prejunctional facilitatory purinoceptors, which were initiated by alpha 1-adrenoceptor stimulation; i.e. transsynaptic regulation of neurotransmission.

Adenosine Triphosphate↗
PubMed1999

A case of diffuse pulmonary arteriovenous fistula.

A 30-year-old Japanese woman was admitted to hospital for dyspnea. She had a history of corrective surgery for a large atrial septal defect and partial anomalous pulmonary venous drainage, which had produced cyanosis in her infancy. However, her cyanosis continued postoperatively. Angiography revealed a double inferior vena cava (IVC), with the left IVC connected with the hemiazygos vein and the right IVC with the left atrium through a very small orifice. Most of the blood from the 2 IVCs flowed into the superior vena cava via the distended azygos and hemiazygos veins. Pulmonary arteriography revealed no abnormal structures. Pulmonary arterial pressure was normal. There was marked pulmonary venous oxygen desaturation. Perfusion lung scintigraphy revealed multiple segmental perfusion defects. These findings suggested the presence of diffuse microscopic pulmonary arteriovenous fistulas bilaterally in the lungs. The patient appears to be the first reported adult case of microscopic and diffuse arteriovenous fistulas. Neither resection of the arteriovenous fistulas nor corrective surgery for the diversion was indicated, and heart-lung transplantation might be the only treatment able to relieve her dyspnea.

Adult↗
PubMed1999

Detection of a biphasic response of hibernating myocardium by dobutamine-stress electrocardiography-gated technetium-99m-tetrofosmin single photon emission computed tomography--a case report.

A woman with coronary artery disease underwent a new imaging technique: dobutamine-stress electrocardiography (ECG)-gated tetrofosmin-single photon emission computed tomography (SPECT). Dobutamine-stress ECG-gated tetrofosmin-SPECT with automatic left ventricular function analysis software programs detected improvement and a biphasic response of dysfunctional myocardium during dobutamine infusion, which suggested viable but hibernating myocardium. Dobutamine-stress ECG-gated tetrofosmin-SPECT with automatic left ventricular function analysis software programs has the potential to detect viable but dysfunctional myocardium with contractile reserve.

Aged↗
PubMed1999

Protective effect of Irsogladine on monochloramine induced gastric mucosal lesions in rats:a comparative study with rebamipide.

AIM:To examine the effect of irsogladine, a novel antiulcer drug, on the mucosal ulcerogenic response to monochloramine (NH(2)Cl) in rat stomach, in comparison with rebamipide, another antiulcer drug with cytoprotective a ctivity.METHODS AND RESULTS:Oral administration of NH(2)Cl-(120mM) produced severe hemorrhagic lesions in unanesthetized rat stomachs.Both irsogladine (1mg/kg-10mg/ kg,po) and rebamipide (30mg/kg-100mg/kg, po) dose dependently prevented the development of these lesions in response to NH(2)Cl, the effect of irsogladine was significant at 3mg/kg or greater, and that of rebamipide only at 100mg/kg. The protective effect of irsogladine on NH(2)Cl induced gastric lesions was significantly reduced by N( G) nitro L arginine methyl ester (L-NAME) but not by indomethacin, while that of rebamipide was significantly mitigated by indomethacin but not by L-NAME. Topical application of NH(2)Cl-(20mM)caused a marked reduction of potential difference (PD) in exvivo stomachs. This PD reduction was not affected by mucosal application of irso-gladine, but significantly prevented by rebamipide. The mucosal exposure to NH(4)OH (120mM) also caused a marked PD reduction in the ischemic stomach (bleeding from the carotid artery), resulting in gastric lesions. These ulcerogenic and PD responses caused by NH(4)OH plus ischemia were also significantly mitigated by rebamipide, in an indomethacin sensitive manner, while irsogladine potently prevented such lesions without affecting the PD response, in a L-NAME sensitive manner.CONCLUSION:These results suggest that (1)NH(2)Cl gen-erated either exogenously or endogenously damages the gastric mucosa, (2)both irsogladine and rebamipide protect the stomach against injury caused by NH(2)Cl,and (3)the mechanism underlying the protective action of irsogladine is partly mediated by endogenous nitric oxide, while that of rebamipide is in part mediated by endogenous prostaglandins.

Journal Article↗
PubMed1999

Comparison of magnetic resonance imaging and ultrasonography in the early diagnosis of interstitial pregnancy.

OBJECTIVE: To investigate the usefulness of ultrasonography (USG) and magnetic resonance imaging (MRI) in the early diagnosis of interstitial pregnancy. STUDY DESIGN: Four cases of interstitial pregnancy that showed characteristic ultrasonographic and MRI findings were studied. All cases received cornual resection, and the presence of interstitial pregnancy was confirmed by pathologic examination. RESULTS: Three of four cases had a gestational sac in the uterine cornu or a protruding cornual mass and myometrium between the sac and uterine cavity on both USG and MRI. In the remaining case, preoperative diagnosis was inconclusive because no gestational sac was demonstrated by USG or MRI. Color flow mapping was conducted in three cases and revealed prominent peritrophoblastic blood flow. CONCLUSION: The findings suggest that USG combined with color flow mapping is the first choice in the early diagnosis of interstitial pregnancy. MRI, which is an extremely expensive imaging technology, should be used only if transvaginal USG with color flow mapping is inconclusive in ruling out the diagnosis of interstitial pregnancy.

Adult↗
PubMed1999

Nitric oxide, superoxide radicals and mast cells in pathogenesis of indomethacin-induced small intestinal lesions in rats.

We investigated the pathogenic mechanism of indomethacin-induced small intestinal lesions, in relation to nitric oxide (NO), superoxide radicals and mast cells. Rats received indomethacin (1-6 mg/kg) s.c. once daily for 3 days, and the small intestine was examined for lesions 24 hr after the final administration of indomethacin. Indomethacin caused hemorrhagic lesions in the small intestine, mostly in the jejunum and ileum, in dose- and time-dependent manners, with concomitant increase of mucosal microvascular permeability. This treatment also caused an increase of inducible NO synthase (iNOS) activity with the expression of its mRNA, myeloperoxidase (MPO) activity as well as thiobarbituric acid reactants (TRBAS) in the mucosa, and the changes in iNOS activity preceded those in MPO activity and TRBAS as well as lesion development. These lesions induced by indomethacin were prevented by aminoguanidine (a selective inhibitor of iNOS), dexamethasone (an inhibitor of iNOS mRNA transcription), allopurinol (a xanthine oxidase inhibitor), hydroxyurea (a neutrophil reducing agent) and FR167653 (an inhibitor of interleukin-1/tumor necrosis factor-alpha production) as well as 16,16-dimethyl prostaglandin E2ń. Likewise, the severity of these lesions was also reduced by mast cell stabilizers FPL-52694 and disodium cromoglycate and a lipoxygenase inhibitor TMK-688, but not affected by tripelennamine (a histamine H1-receptor antagonist) or methysergide (a serotonin receptor antagonist). These results suggest that: 1) the pathogenic mechanism of indomethacin-induced small intestinal lesions involves superoxide radicals as well as NO produced by iNOS, 2) the deleterious effect of NO may be accounted for by the cytotoxic action of peroxynitrite, produced from NO in the presence of superoxide radicals, and 3) the mast cells may also be involved in the process of small intestinal ulceration, although the mediator responsible remains undefined.

Animals↗
PubMed1999

[Assessment of beta-methyl lodophenyl pentadecanoic acid myocardial scintigraphy in patients with chronic pulmonary diseases].

The purpose of this study was to determine whether impaired fatty acid metabolism occurs in the right ventricle of patients with chronic pulmonary diseases (TB sequelae, TB seq.; 8, and chronic pulmonary emphysema. CPE; 14). 123I-BMIPP myocardial scintigraphy was performed on 22 subjects. The RV-BMIPP index (ratio of radioactivity in the right ventricle to that in the upper mediastinum), LV-BMIPP index (ratio of radioactivity in the left ventricle to that in the upper mediastinum), and RVc/LVc (ratio of radioactivity in the right ventricle to that in the left ventricle) were calculated to compare the distribution of radioactivity in the right and left ventricles. We also examined the correlations between these parameters and parameters of blood gas analysis and pulmonary hemodynamics. The RV-BMIPP index. LV-BMIPP index, and RVc/LVc were elevated in the TB seq. and CPE patient groups compared to the control group. The RV-BMIPP and LV-BMIPP indices demonstrated significant, negative correlations with PaO2; also a significant positive correlation was observed between the RV-BMIPP index and mean pulmonary arterial pressure. On the other hand, no significant correlation was found between the LV-BMIPP index and mean pulmonary arterial pressure. In the arm-stretching test under right heart catheterization, the RV-BMIPP and LV-BMIPP indices demonstrated significant, positive correlations with the cardiac index during exercise. These results suggest that hypoxemia accelerates fatty acid metabolism in the myocardium, and that local pressure overloading accelerates fatty acid metabolism in the right ventricle. Anomalies of fatty acid metabolism in the right ventricle may appear in patients with chronic pulmonary disease, and could be an adaptation to hypoxemia and overload, not an impairment.

Aged↗
PubMed1999

Factors influencing late survival after abdominal aortic aneurysm repair in Japanese patients.

BACKGROUND: To determine the factors influencing the prognosis of patients with abdominal aortic aneurysms (AAA), the clinical characteristics and long-term survival of 366 consecutive patients were examined and compared with those in previous Western studies. METHODS: During the period from January 1979 to December 1995, 376 patients with AAA were admitted to our hospital. Among these, 332 consecutive patients underwent elective reconstruction of infrarenal AAAs. The remaining 44 patients were not surgically treated. With use of the data from the patients who underwent AAA resection, the relationship of various risk factors, such as cardiac dysfunction, hypertension, renal dysfunction, pulmonary dysfunction, and age, to survival rate was investigated by univariate and multivariate analysis. RESULTS: The operative mortality rate was 0.6%. The survival of the patients who underwent the operation at 5 years was 71.0% and at 10 years 51.8%. The survival rate of the patients who were not surgically treated at 5 years was 26.0% and at 10 years 14.9%. There was a significant difference between the 2 groups. A univariate analysis was performed on each possible risk factor affecting survival rates. In relation to the survival rate of 5 and 10 years, there was no statistical significant difference between patients with or without heart disease or hypertension. By contrast, factors influencing long-term survival were associated with renal dysfunction, pulmonary dysfunction, and age at time of surgery. Multivariate analysis of risk factors affecting survival rates demonstrated that renal dysfunction, pulmonary dysfunction, and age at the time of operation were found to be significant, respectively. The main cause of the death for the long-term survival patients with AAA repair was malignancy, whereas that in the patients without repair was rupture. CONCLUSIONS: Risk factors influencing survival after AAA repair were renal dysfunction, pulmonary dysfunction, and advanced age in Japanese patients. In addition, the main cause of death after aneurysmal resection was malignancy. These results were different from outcomes in Western patients. We need to carefully watch out for malignancy during the follow-up period after AAA resection.

Aged↗
PubMed1999

[Accuracy, precision and clinically acceptable level of complete blood cell count by an automated multichannel hematology analyzer].

Measurement of complete blood cell count (CBC) is one of the essential laboratory tests. In this study, the accuracy of CBC was high, when measured by six different automated blood cell counters, including SE-9000/RAM-1, CELL-DYN 4000, ADVIA 120, VEGA RETIC-LC141 or GEN*S. The correlations of CBC counts among these instruments were also good. In contrast, the accuracy in abnormal samples depended on matching the instrument and type of clinical conditions. Internal quality control of automated multichannel hematology analyzers was recommended by the NCCLS H26-A in 1996. However, actual external quality control of the CBC count was poorly understood. We surveyed three samples from healthy volunteers for CBC values in 1997. Among six different instruments, the inter-assay of the red blood cell count (RBC), hemoglobin, hematocrit and MCV was fairly good, shown as < 4.2%, < 3.0%, < 4.4% and < 3.4%, respectively. In contrast, the inter-assay of the white blood cell count (WBC) and platelet (PLT) was not good, shown as < 11.4% and < 9.6%, respectively. The clinically acceptable levels for the blood cell count were reported to be 4% for RBC, 3% for hemoglobin, 4% for MCV, 5% for WBC and 7% for PLT, by JCCLS in 1994. The clinically acceptable CBC by hematologists at Keio University resembled those by councilors of The Japanese Society of Clinical Hematology, whereas, residents at Keio University and general physicians required more precise clinical CBC counts. These results indicate that a larger study is needed to clarify the accuracy, clinically acceptable level, and performance of different automated blood cell counters.

Blood Cell Count↗
PubMed1999

[Signal transduction systems of angiotensin II receptors].

Angiotensin (A) II is a potent constrictor as well as growth stimulant of vascular smooth muscle cell caused by activation of AT1 receptor signal transduction systems. There are two major signal systems of AT1 receptor: one leads to an increase in cytosolic free calcium levels causing smooth muscle contraction which may result in high blood pressure, and the other leads to smooth muscle proliferation and inflammation which may result in atherosclerosis. AT1 receptor activation induces phosphinositide hydrolysis by phospholipase C and creates an inositol phosphate, which release calcium from cytosolic calcium pools. Cytosolic calcium can also be elevated by activation of calcium channel via a link between AT1 receptor and a G protein. Protein phosphorylation triggered by AT1 receptor is important for cell growth, in which tyrosine kinase, serine/threonine kinase and protein kinase C are involved. Free radicals are generated by NADH/NADPH oxidase in response to AT1 receptor activation, causing expression of genes leading to atherosclerosis. On the other hand, activation of AT2 receptor is shown to play a role of lowering blood pressure. Some phosphatases and NO/cyclic GMP would be involved in the mechanism. In renal vasculature, endothelium dependent epoxygenase products are synthesized by AT2 receptor stimulation causing vasorelaxation. In summary, AT1 receptor signals are vasopressive and evoke atherosclerosis, whereas AT2 receptor signals may possibly be vasodilatory.

Animals↗
PubMed1999

[Histidine buffered cardioplegic solution (HBS) provides effective myocardial preservation with wider safety margin in patients with prolonged ischemia].

Increasingly complex techniques of cardiac surgery often require prolonged myocardial ischemia. We previously reported a better myocardial preservation with histidine containing cardioplegia (HBS) in human open heart surgery. To see a safety margin of this cardioplegia for prolonged myocardial preservation, this study was retrospectively done. One hundred twenty-six patients received either intermittent multidose (20-30 minute) cold blood cardioplegia (CBC) plus topical cooling (aotric cross clamp time (ACC) < 120 minutes, n = 63) or HBS (n = 63). HBS group was divided into two groups with either short ACC (< or = 120 minutes, HBS-S, n = 46) or long ACC (> 120 minutes, HBS-L, n = 17). Cardiac index (C.I.) and dopamin/dobutamine requirement were measured 3, 6, and 12 hours post-bypass. Incidence of homologous blood transfusion was also studied. There was two deaths due to LOS in HBS-S group; four patients in HBS group required 5 DC cardioversion, whereas six patients required a total of 12 DC cardioversion in CBC group. Functional recovery were significantly better with significantly lower inotropic requirements in HBS-S group than CBC group and HBS-L group. Although preoperative ejection fraction and C.I. were significantly lower in HBS-L group, post-operative cardiac function and inotropic requirements in HBS-L was comparable to that seen in CBC group. We conclude that the highly buffered histidine crystalloid cardioplegia solution provides effective myocardial preservation with a wider safety margin for prolonged myocardial preservation in open heart surgery.

Adult↗