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Biomedical subjects

N Konno

Publications and source records attributed to N Konno.

At least 19 recordsLinked to original sources
PubMed2004

Effect of glucocorticosteroids on tumour necrosis factor-alpha-induced intercellular adhesion molecule-1 expression in cultured primary human nasal epithelial cells.

OBJECTIVE: In order to confirm the direct effect of glucocorticosteroids on epithelial intercellular adhesion molecule-1 (ICAM-1) expression, we examined ICAM-1 expression on primary cultured human nasal epithelial cells (HNECs) at both protein and mRNA levels. MATERIAL AND METHODS: HNECs were stimulated with recombinant human TNF-alpha (20 pg/mL-20 ng/mL) for specified time periods (0, 12, 24, and 48 h) and ICAM-1 mRNA and the soluble ICAM-1 (sICAM-1) concentrations were measured by quantitative RT-PCR and ELISA, respectively. We also evaluated surface expression of ICAM-1 by flow cytometry 48 h after stimulation and determined the effect of dexamethasone (DEX) on TNF-alpha-induced ICAM-1 expression. RESULTS: Significant increases in ICAM-1 gene expression in HNECs were initially detected at 24 h, peaking at 48 h after the stimulation. The TNF-mediated-ICAM-1 mRNA and ICAM-1 surface expression at 48 h was significantly inhibited by co-incubation with human recombinant soluble TNF receptor I. Similarly, TNF-alpha-induced release sICAM-1 occurred in a time- and concentration-dependent manner. DEX 10(-6) M attenuated the TNF-alpha-induced ICAM-1 expression at mRNA and protein levels. CONCLUSIONS: Our finding suggests a potential role for topical steroids in allergic rhinitis in suppressing inflammatory reactions in the nasal mucosa by regulating ICAM-1 expression on nasal epithelium.

Adult↗
PubMed2003

Congestive heart failure is associated with the rate of bone loss.

AIMS: To characterize relationships between mineral homeostasis, bone turnover, bone mass, and congestive heart failure (CHF), we evaluated 75 women with mild to moderate CHF. METHODS AND RESULTS: We examined the association in annual rate of change in spinal bone mineral density (BMD) with polymorphism of the vitamin D receptor (VDR) gene. Compared with the control group, the CHF group had reduced left ventricular ejection fraction (LVEF: 68.2 +/- 7.5% vs. 60.2 +/- 12.9%; P = 0.0249), human atrial natriuretic peptide (hANP) was elevated (hANP: 10.7 +/- 4.7 pmol L-1 vs. 25.8 +/- 24.2 pmol L-1; P = 0.001) and had lower peak VO2 (22.3 +/- 7.5 mL kg-1 min-1 vs. 15.8 +/- 7.4 mL kg-1 min-1; P = 0.0429). The CHF patients with the VDR FF genotype had a significantly high annual rate of decrease in BMD. In the CHF patients with the VDR FF genotype, urinary calcium excretion (FECa) was elevated (1.40 +/- 0.91% vs. 2.39 +/- 1.40%; P = 0.028), and serum bone-type alkaline phosphatase (B-ALP) was reduced (62.6 +/- 13.7 IU L-1 vs. 47.0 +/- 18.6 IU L-1; P = 0.0123). Also, FECa was correlated positively with furosemide dose (R = 0.881; P = 0.0087) and hANP concentrations (R = 0.635; P = 0.0147) and negatively with DeltaBMD (R = 0.72; P = 0.044) in the CHF patients with the VDR FF genotype. CONCLUSION: The CHF patients with the VDR FF genotype have higher rates of bone loss. These patients may need to increase their calcium intake and BMD may need to be followed more carefully over time.

Absorptiometry, Photon↗
PubMed2002

Autoimmune thyroid disease accompanied by recurring episodes of painful thyroid ameliorated by thyroidectomy.

A 71-yr-old female initially presented with clinical and biochemical hyperthyroidism with high TSH binding inhibitory immunoglobulin (TBII) and anti-thyroid peroxidase antibody (TPOAb) titers. Histological findings of the thyroid revealed hyperplasia with a focal germinal center, indicating Graves' disease and mild focal chronic thyroiditis. Four episodes of painful and tender thyroid occurred over the next 2 yr accompanied by acute inflammatory reactions. The first episode that developed while the patient was in a hyperthyroid state was soon followed by hypothyroidism associated with further increases in anti-thyroglobulin antibody (TGAb) and TPOAb titers. The subsequent 3 episodes occurred during the hypothyroid state, when the TGAb titer progressively increased with each episode. We performed subtotal thyroidectomy to prevent further episodes. Specimens obtained at thyroidectomy showed that extreme fibrosis had replaced the thyroid parenchyma with collapsed follicles and moderate lymphocyte infiltration. No further episodes occurred after thyroidectomy, and during a 3-yr follow-up period, TBII and thyroid-stimulating antibody (TSAb) disappeared and TGAb and TPOAb titers decreased. This case report provides further evidence supporting the notion that thyroid epithelial destruction progresses during relatively short periods of recurrent painful thyroid and that thyroidectomy helps patients affected by this condition that are unresponsive to other treatment strategies.

Aged↗
PubMed2001

Effect of tributyltin on the N-methyl-D-aspartate (NMDA) receptors in the mouse brain.

The purpose of this study was to determine the effect of tributyltin chloride (TBTCI) on the NMDA receptor by in vitro and in vivo experiments. In the first in vitro experiment, the binding of [3H]MK-801 and of [3H]-CGP39653 were studied in membrane preparations from the cerebral cortex of intact mice to obtain control values. Saturation experiments for [3H]MK-801 and [3H]CGP39653 revealed single binding sites with Kd values of 10.27 and 37.8 nM, and receptor densities of 1.75 and 2.20 pmol/mg of protein, respectively. In the second in vitro experiment, displacement studies were carried out with TBTCI over a concentration range of 0.1 microM to 2 mM. TBTCI inhibited [3H]MK-801 binding but did not affect [3H]CGP39653 binding. In the in vivo experiments, the mice received 1-125 ppm TBTCI in the diet ad libitum for 30 days. Ligand binding to cortical membrane preparations from each mouse was measured by a one-concentration point (2 nM) binding assay. [3H]MK-801 binding was significantly lowered (P < 0.05) in the 5 and 125 ppm TBTCl-exposed animals compared with the controls. [3H]CGP39653 binding was also significantly lowered (P<0.05) in the 1 and 125 ppm TBTCI-exposed animals compared with the controls. These results suggest that the NMDA receptors in the mouse brain are sensitive to relatively low level exposure to TBTCl.

2-Amino-5-phosphonovalerate↗
PubMed2000

Treatment of hypoglossia-hypodactyly syndrome without extremeity anomalies.

Three cases of hypoglossia-hypodactyly syndrome without limb deformities are reported. All exhibited different degrees of tongue hypoplasia, micrognathia, retrognathia with a very narrow space between the left and right halves of the mandible, constricted isthmus, and only one lower incisor. Bone lengthening for the midline mandibular hypoplasia and orthodontic treatment were performed in the three cases with satisfactory results.

Bone Lengthening↗
PubMed2000

The depressor function of biceps on the head of the humerus in shoulders with tears of the rotator cuff.

We investigated the function of biceps in 18 patients (19 shoulders) with lesions of the rotator cuff. Their mean age was 59 years. Another series of 18 patients (19 shoulders) with normal rotator cuffs as seen on MRI acted as a control group. Their mean age was 55 years. A brace was used to maintain contraction of biceps during elevation. Anteroposterior radiographs were obtained with the arm elevated at 0 degrees , 45 degrees and 90 degrees with and without contraction of biceps. The distance between the centre of the head of the humerus and the glenoid was compared in the two groups. We found that in the group with tears there was significantly greater proximal migration of the head of the humerus at 0 degrees and 45 degrees of elevation without contraction of biceps but depression of the head of the humerus at 0 degrees, 45 degrees and 90 degrees when biceps was functioning. We conclude that biceps is an active depressor of the head of the humerus in shoulders with lesions of the rotator cuff.

Adult↗
PubMed1999

Contractile responses to alpha1-adrenoceptor agonists in isolated human male and female urethra.

OBJECTIVE: To investigate the contractile responses mediated through alpha1-adrenoceptors in human urethra and to evaluate the effectiveness of NS-49 [(R)-(-)-3'-(2-amino-1-hydroxyethyl)-4'-fluoromethanesulphonanilide++ + hydrochloride], a novel alpha1-adrenoceptor agonist, against contraction of the human urethra. MATERIALS AND METHODS: The contractile responses were assessed in 10 male prostatic urethrae and six female urethrae. Antagonism was evaluated in the urethra using phenylephrine, a nonselective alpha1-adrenoceptor agonist, cumulatively applied > 20 min after applying 0.1 micromol/L prazosin or 0.1 micromol/L 5-methylurapidil, a selective alpha1A-adrenoceptor antagonist. Agonism was determined in both male and female urethrae to obtain the concentration-response curve for the agonist. RESULTS: Phenylephrine caused both male and female urethrae to contract, and showed high potency and efficacy. Prazosin antagonized these contractions with low affinity (apparent pKB of 8.30 in male urethrae). 5-Methylurapidil, also antagonized the contractions with low affinity (apparent pKB of 7.88 in male urethrae). Noradrenaline and phenylephrine caused both male and female urethrae to contract, with high potency and efficacy. A novel and selective alpha1A-and alpha1L-adrenoceptor agonist, NS-49, induced contractile responses with high potency and moderate efficacy, whereas methoxamine induced contractions with low potency and moderate efficacy. Norephedrine was a very weak contractile agonist. CONCLUSION: In the human urethra, phenylephrine-induced contractions were mediated through alpha1L-adrenoceptors and not through alpha1A-adrenoceptors. Contractions of the human urethra induced by NS-49 were also mediated mainly through alpha1L-adrenoceptors, with high potency and moderate efficacy. NS-49 may therefore be useful for the treatment of urinary stress incontinence, with minimal side-effects because it has subtype selectivity.

Adrenergic alpha-Agonists↗
PubMed1999

Generation of free radicals and the damage done to the sarcoplasmic reticulum during reperfusion injury following brief ischemia in the canine heart.

Free radical generation was studied by the electron spin resonance (ESR) technique using alpha-phenyl N tert butyl nitrone (PBN) in a brief ischemia-reperfusion model of the canine heart, and correlated with biochemical changes of the sarcoplasmic reticulum (SR). ESR spectra (aH=0.3-0.4mT, aN=1.43-1.58mT) were observed as PBN spin adducts, which peaked at levels 5-fold above the control levels at 5 min after reperfusion. The simulated coupling constants of PBN spin adducts suggested that the sample should contain at least 2 carbon-centered radicals at 5 min after reperfusion (radical A: aH=0.350mT, aN=1.485mT; radical B: aH=0.370mT, aN=1.615 mT). At this time point, a significant reduction in Ca-ATPase activity of the SR was found without degradation of the major ATPase protein. Superoxide dismutase (SOD) significantly reduced the intensity of the PBN spin adduct signals and preserved the Ca-ATPase activity of the SR to 80% of the control level. Reperfusion injury after brief ischemia may be the result of inactivation of intracellular Ca-ATPase by free radicals generated during reperfusion, and SOD contributes to the protective effect by scavenging the radicals.

Animals↗
PubMed1998

Humeral attachment of the supraspinatus and infraspinatus tendons: an anatomic study.

We investigated the anatomic relationship of the supraspinatus (SSP) and infraspinatus (ISP) tendons to the three facets of the greater tuberosity. After removing the superficial layer of the cuff to expose the tendon fibers in 10 embalmed shoulders, the cuff tendon attachment to the facets was examined, and the location of attachment was measured in reference to (1) the anterior margin of the greater tuberosity and (2) the superior margin of the sulcus (anatomic neck without cartilage). The SSP tendon attached to the superior facet and the superior half of the middle facet. The ISP tendon attached to the entire middle facet, covering a portion of the SSP tendon. Thus, the anterior half of the superior cuff tendon (12.6 +/- 1.1 mm) was composed of only the SSP tendon, whereas the posterior half (9.8 +/- 3.2 mm) was composed of both the SSP and ISP tendons. The sulcus was located not at the SSP-ISP interval but slightly posterior to the posterior margin of the SSP tendon (4.3 +/- 2.4 mm). We conclude that (1) there is an overlap between the SSP and ISP tendons identifiable by the facets or the distance from the anterior greater tuberosity and (2) the sulcus is located slightly posterior to the posterior margin of the SSP tendon.

Aged↗
PubMed1998

Cystic changes of the humeral head on MR imaging. Relation to age and cuff-tears.

We obtained MR images of 140 painful shoulders in 134 patients to determine the relationship between cystic changes of the humeral head and integrity of the rotator cuff. Cystic changes were observed in 49 shoulders (35%) and the commonest site was in the bare bone area of the anatomical neck, and the second commonest site was at the attachment of the supraspinatus tendon. Cystic changes in the bare bone area were observed equally often in shoulders with or without rotator cuff tears (27% and 18%, respectively) and were more frequently observed in the elderly. Cystic changes at the attachment of the supraspinatus and subscapularis tendons were specific to rotator cuff tears: they were observed in 28% of rotator cuff tears, but in none of those with an intact cuff. We conclude that there are two distinct types of cystic changes: one at the attachment of the supraspinatus and subscapularis tendons, which is closely related to tears of these tendons, and the other in the bare bone area of the anatomical neck, which is related to aging.

Adolescent↗
PubMed1998

Electromyographic activities of the biceps during arm elevation in shoulders with rotator cuff tears.

We investigated electromyographic activities of the biceps in 40 shoulders with full-thickness tears of the rotator cuff and 40 asymptomatic shoulders, with a normal rotator cuff on MRI, to determine the role of the biceps in cuff-deficient shoulders. Using surface electrodes, biceps activities were recorded during arm elevation in the scapular plane with and without a 1-kg load. The percentages of integrated electromyograms to the maximum voluntary contraction (%MVC) were obtained at 30 degrees, 60 degrees, 90 degrees, and 120 degrees of elevation. In the normal shoulders, %MVC of the biceps was always less than 10% through the arc of elevation both with and without load. Among 40 shoulders with rotator cuff tears, 14 showed increased activities of the biceps more than 10% in %MVC (p < 0.0001), whereas the remaining 26 shoulders had activities similar to the normal shoulders. The biceps activities in these 14 shoulders increased with load application and at higher angles of elevation. The muscle strength tended to be weaker in shoulders with increased biceps activities than in those without. Our findings suggest a potential supplemental function of the biceps in shoulders with rotator cuff tears.

Adult↗
PubMed1997

Changes in microsomal membrane phospholipids and fatty acids and in activities of membrane-bound enzyme in diabetic rat heart.

Diabetes mellitus is associated with alterations in lipid metabolism and cardiac dysfunction despite an absence of coronary arteriosclerotic changes. To investigate mechanisms of cardiac dysfunction in diabetic cardiomyopathy, we studied the relation between activities of membrane-bound enzymes and surrounding phospholipids in rats with diabetes induced with a single intravenous injection of streptozotocin (65 mg/kg). We found that total phospholipid content of sarcoplasmic reticulum membrane increased significantly 8 weeks after treatment with streptozotocin owing to increases in phosphatidylcholine and phosphatidylethanolamine, a decrease in arachidonic acid, and an increase in docosahexaenoic acid in the early stage of diabetes. Sarcolemmal Na+/K(+)-ATPase activity and the number of receptors decreased in isolated cardiomyocytes of diabetic rats 8 weeks after streptozotocin administration. The Ca2+ uptake of both sarcoplasmic reticulum and mitochondria decreased simultaneously in permeabilized, isolated cardiomyocytes from diabetic rats. The depression of membrane-bound enzyme activities was correlated with alterations in phospholipids, which are closely related to the microenvironment of membrane-bound enzymes and influence intracellular Ca2+ metabolism. Because these changes in phospholipids and fatty acids were reversible with insulin therapy, they are diabetes-specific and might be a cause of cardiac dysfunction in diabetes.

Animals↗
PubMed1997

Carcinosarcoma in the region of the female urethra.

A 61-year-old woman with acute urinary retention was found to have a carcinosarcoma in the region of the urethra. Evaluation of the computed tomogram suggested a urethral tumor, which was resected by a transperineal approach. She received local radiotherapy after surgery, and is alive at 1-year follow-up with a tumor metastasis to the pelvis.

Carcinosarcoma↗
PubMed1997

Protective effect of captopril on ischemic myocardium.

The protective effect and mechanism of action of the angiotensin-converting enzyme inhibitor (ACE-I) captopril was investigated in organelles from ischemic myocardial cells in a canine coronary ligation model. Sarcoplasmic reticulum (SR) and mitochondrial fractions were extracted from ischemic and nonischemic myocardial cells from captopril- and saline-treated (control) hearts. Heart rate, cardiac output, and right ventricular systolic blood pressure were similar in the captopril-treated and control groups. Left ventricular systolic blood pressure (LVPs) decreased gradually to 89% of the baseline value after captopril administration, and to 78% of the baseline value after ligation. Ca-ATPase activity in the SR, the respiratory control ratio (RCR) in the mitochondria, and dinitrophenol (DNP)-stimulated ATPase activity were significantly higher in ischemic myocardium from the captopril-treated group than from the saline-treated (control) group. The SH group content of both organelles was higher in the captopril-treated group. Our results suggest that, in addition to their hemodynamic effects, ACE-I agents containing SH groups protect the myocardium from ischemic damage by preventing enzyme oxidation.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1997

Reversal of early metabolic dysfunction in hypertensive rat left-ventricular myocytes by angiotensin-converting enzyme inhibition.

We evaluated the effects of angiotensin-converting enzyme (ACE) inhibition on metabolic changes in myocardial organelles, myocardial hypertrophy, and interstitial fibrosis in the early stage of hypertension. An ACE inhibitor, imidapril (2.5 mg/kg per day), a calcium-channel blocker, diltiazem (30 mg/kg per day), or vehicle was given to spontaneously hypertensive rats (SHRs) from 10 to 18 weeks of age. Single myocytes were isolated enzymatically from the left ventricles of these SHRs and normotensive Wistar-Kyoto (WKY) controls at 18 weeks of age. In single ventricular myocytes, enzyme activities in the sarcoplasmic reticulum (SR) and the sarcolemma (SL) and the mitochondrial respiratory control ratio (RCR) were determined. In 18-week-old SHRs receiving vehicle, myocardial hypertrophy and interstitial fibrosis developed, and SR Ca2+ AT-Pase activity and the mitochondrial RCR were significantly lower and SL Na+, K(+)-ATPase activity was significantly higher than in age-matched WKYs. However, compared with diltiazem, imidapril was better able to prevent the development of myocardial hypertrophy and interstitial fibrosis, to improve SR Ca(2+)-ATPase activity and the mitochondrial RCR, and to increase SL Na+, K(+)-ATPase activity. These results suggest that ACE inhibition can prevent the development of morphologic changes associated with hypertension-induced left ventricular remodeling, such as myocardial hypertrophy and interstitial fibrosis, and can counteract ongoing dysfunction of organelle metabolism early in the development of hypertension.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1997

The effects of dopamine, dobutamine and amrinone on mitochondrial function in cardiogenic shock.

The impairment of mitochondrial in non-infarcted myocardium under cardiogenic shock complicated by acute myocardial infarction was studied. We induced acute myocardial infarction in dogs by ligating the circumflex branch of the left coronary artery (LCX). On basis of left ventricular systolic pressure (LVPs) after 60 minutes, we divided the dogs into two groups: a group in which LVPs fell to below 70% of the pre-LCX ligation level, and a Control group in which LVPs remained more than 90%. The former group was further divided into four subgroups, depending on infusion of dopamine, dobutamine, amrinone or saline after 90 minutes. Mitochondria were prepared and mitochondrial respiratory activity determined. In the Saline group, hemodynamics became reduced to less than 70% of the preligation level after 120 minutes, however, in the Dopamine and Dobutamine groups, hemodynamics became restored to the preligation level. In the Amrinone group, LVPs decreased slightly, while cardiac output, LV Max. dp/dt and myocardial blood flow increased. In the Saline group, mitochondria in the non-infarcted myocardium functioned at a lower level of activity than that of the Control group. However, in the Dopamine, Dobutamine, and Amrinone groups, the mitochondria functioned at a higher level. Electron microscopy revealed mitochondrial damage in the Saline group only. The results indicate that an energy production disorder in the non-infarcted myocardium may have pathogenetic implications in cardiogenic shock associated with acute myocardial infarction, while dopamine, dobutamine, and amrinone improve mitochondrial function, and ultimately improve cardiac function.

Adenosine Triphosphatases↗
PubMed1996

Long-term cadmium exposure induces anemia in rats through hypoinduction of erythropoietin in the kidneys.

Cadmium (Cd), a highly toxic heavy metal, is distributed widely in the general environment of today. The characteristic clinical manifestations of chronic Cd intoxication include renal proximal tubular dysfunction, general osteomalacia with severe pains, and anemia. We have recently reported that the serum level of erythropoietin (EPO) remained low despite the severe anemia in patients with Itai-itai disease, the most severe form of chronic Cd intoxication. In order to prove that the anemia observed in chronic Cd intoxication arises from low production of EPO in the kidneys following the renal injury, we administered Cd to rats for a long period and performed the analysis of EPO mRNA inducibility in the kidneys. The rats administered Cd for 6 and 9 months showed anemia with low levels of plasma EPO as well as biochemical and histological renal tubular damage, and also hypoinduction of EPO mRNA in the kidneys. The results indicate that chronic Cd intoxication causes anemia by disturbing the EPO-production capacity of renal cells.

Anemia↗