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T Oshima

Publications and source records attributed to T Oshima.

At least 217 records · Page 12Linked to original sources
PubMed1997

Inhibitory effect of macrolides on interleukin-8 secretion from cultured human nasal epithelial cells.

The mechanism of macrolide therapy in chronic sinusitis patients is unclear. The authors studied the effect of macrolides on interleukin (IL)-8 secretion from cultured human nasal epithelial cells. Epithelial cells harvested from the nasal polyps of patients with chronic sinusitis were primary-cultured, and secreted IL-8 in culture media was measured by enzyme immunoassay. The cells secreted considerable amounts of IL-8 constitutively and in response to lipopolysaccharide. The secretion was significantly inhibited by 10(-5) M of erythromycin, clarithromycin, roxithromycin, and josamycin. 10(-6) M erythromycin still showed the inhibitory effect, whereas the same concentration of josamycin did not. These results indicate that macrolide antibiotics may act as an immunomodulator to reduce IL-8 in inflammatory sites and, at least partially, account for the clinically discrepant effects between 14- and 16-membered ring macrolides in long-term low-dose therapy for chronic sinusitis.

Adult↗
PubMed1997

A new Thermus-Escherichia coli shuttle integration vector system.

We established a Thermus thermophilus strain in which the pyrE gene (coding for orotate phosphoribosyltransferase of the pyrimidine biosynthetic pathway) was totally deleted. We also constructed an integration vector, which consisted of the Escherichia coli plasmid vector pBluescript and a 2.1-kb segment of the T. thermophilus leu operon sequence, for the integration of a foreign gene into a chromosome of the thermophile. pyrE and leuB genes were used as probes to test the integration vector. The integration vector pINV, bearing the pyrE gene, transformed the delta pyrE strain at a frequency of 6 x 10(-5) through a single crossover event. The leuB gene could also be used as another marker of the integration vector system. The vector could be integrated at the expected site. By digesting the chromosomal DNA of the T. thermophilus transformants with a unique restriction enzyme, the vector could be recovered into E. coli after the recircularization in vitro. The kanamycin nucleotidyltransferase gene could be successfully expressed in the thermophile by using pINV.

3-Isopropylmalate Dehydrogenase↗
PubMed1997

Molecular and phylogenetic characterization of isopropylmalate dehydrogenase of a thermoacidophilic archaeon, Sulfolobus sp. strain 7.

The archaeal leuB gene encoding isopropylmalate dehydrogenase of Sulfolobus sp. strain 7 was cloned, sequenced, and expressed in Escherichia coli. The recombinant Sulfolobus sp. enzyme was extremely stable to heat. The substrate and coenzyme specificities of the archaeal enzyme resembled those of the bacterial counterparts. Sedimentation equilibrium analysis supported an earlier proposal that the archaeal enzyme is homotetrameric, although the corresponding enzymes studied so far have been reported to be dimeric. Phylogenetic analyses suggested that the archaeal enzyme is homologous to mitochondrial NAD-dependent isocitrate dehydrogenases (which are tetrameric or octameric) as well as to isopropylmalate dehydrogenases from other sources. These results suggested that the present enzyme is the most primitive among isopropylmalate dehydrogenases belonging in the decarboxylating dehydrogenase family.

3-Isopropylmalate Dehydrogenase↗
PubMed1997

Effects of extracellular ATP on ion transport and [Ca2+]i in Mongolian gerbil middle ear epithelium.

The present study investigates the effects of ATP on ion transport and Ca2+ mobilization in primary cultures of gerbil middle ear epithelium. Extracellular ATP and other nucleotides elicited a transient increase in short-circuit current (I(sc)) in a dose-dependent manner. The rank order of potency in I(sc) responses corresponded with the sequence of the P(2u) purinergic receptor when applied to the mucosal or the basolateral side. Extracellular ATP induced a rise in the intracellular Ca2+ concentration ([Ca2+]i) in a dose-dependent manner. A similar rank order of potency in the ATP-induced increases in [Ca2+]i was observed. The time courses of the [Ca2+]i responses induced by ATP closely paralleled those of the I(sc) responses. 1,2-Bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester greatly reduced the increase in the I(sc) and [Ca2+]i responses to ATP. Diphenylamine-2-carboxylate, 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid, quinidine, and Ba2+ significantly blocked the ATP-stimulated I(sc). Glibenclamide had no effect on the ATP-stimulated I(sc). These results are consistent with the hypothesis that extracellular ATP and other nucleotides induce Cl- secretion across the apical membrane in cultured gerbil middle ear epithelium by activation of the apical Cl- channels via multiple modes of regulation.

Adenosine Triphosphate↗
PubMed1997

Rhinovirus infection of primary cultures of human tracheal epithelium: role of ICAM-1 and IL-1beta.

Exacerbations of asthma are often associated with respiratory infection caused by rhinoviruses. To study the effects of rhinovirus infection on respiratory epithelium, a primary target for respiratory viruses, human rhinovirus (HRV)-2 and HRV-14 were infected to primary cultures of human tracheal epithelial cells. Viral infection was confirmed by showing that viral titers of supernatants and lysates from infected cells increased with time and by polymerase chain reaction. HRV-2 and HRV-14 infections upregulated the expression of intercellular adhesion molecule-1 (ICAM-1) mRNA, the major rhinovirus receptor, on epithelial cells, and they increased the production of interleukin (IL)-1beta, IL-6, IL-8, and tumor necrosis factor (TNF)-alpha in supernatants. Antibodies to ICAM-1 inhibited HRV-14 infection of epithelial cells and decreased the production of cytokines after HRV-14 infection, but they did not alter HRV-2 infection-induced production ofcytokines. IL-1beta upregulated ICAM-1 mRNA expression and increased susceptibility to HRV-14 infection, whereas other cytokines failed to alter ICAM-1 mRNA expression. Furthermore, a neutralizing antibody to IL-1beta significantly decreased viral titers of supernatants and ICAM-1 mRNA expression after HRV-14 infection, but a neutralizing antibody to TNF-alpha was without effect. Immunohistochemical studies revealed that both HRV-14 infection and IL-1beta increased ICAM-1 expression on cultured epithelial cells. These findings imply that HRV-14 infection upregulated ICAM-1 expression on epithelial cells through increased production of IL-1beta, thereby increasing susceptibility to infection. These events may be important for amplification of airway inflammation after viral infection in asthma.

Antibodies↗
PubMed1997

Differential effects of extracellular Mg2+ on thrombin-induced and capacitative Ca2+ entry in human coronary arterial endothelial cells.

Receptor-mediated and capacitative Ca2+ entry are the primary Ca2+ entry pathways in endothelial cells (ECs). The mechanisms for Ca2+ entry via these pathways have not been fully elucidated. In this study, the effect of low and high external Mg2+ concentrations on these Ca2+ entry pathways was examined in human coronary arterial ECs. External Mg2+ concentration did not affect cytosolic free Mg2+ concentration. After exposure to thrombin in Ca(2+)-free medium, addition of Ca2+ to the medium caused a rise in cytosolic free Ca2+ concentration ([Ca2+]i), indicating thrombin-induced Ca2+ influx. Thrombin-induced Ca2+ influx was inhibited by not only low but also high external Mg2+ concentrations. After depletion of endoplasmic Ca2+ stores by thapsigargin, addition of Ca2+ to the medium induced an increase in [Ca2+]i, indicating capacitative Ca2+ entry. Capacitative entry was found to be accelerated by low external Mg2+ and inhibited by high external Mg2+ concentration. Results suggest that receptor-mediated Ca2+ influx requires external Mg2+ but is inhibited by increased external Mg2+ concentrations and that capacitative Ca2+ entry is reduced by external Mg2+ in human coronary arterial ECs.

Calcium↗
PubMed1997

Relationship between insulin resistance and endothelium-dependent vascular relaxation in patients with essential hypertension.

The infusion of L-arginine induces the production of nitric oxide and stimulates the immediate secretion of insulin. To examine the relationship between insulin resistance and endothelium-dependent vascular relaxation in patients with essential hypertension, we evaluated the renal and insulin responses to L-arginine, 500 mg/kg infused intravenously over 30 minutes, in 23 patients with mild essential hypertension who were neither obese nor diabetic and in 20 normotensive control subjects. We found no difference between the two groups in blood glucose or insulin in the fasting condition. The renovascular relaxation induced by L-arginine was significantly less in patients with essential hypertension than in normotensive control subjects. The increase in plasma cyclic GMP in response to L-arginine was lower in hypertensive patients than in normotensive subjects. Although the serum concentrations of glucose in response to L-arginine were similar in the two groups, the serum insulin response of the essential hypertensives was significantly higher than that of the normotensive subjects. In all subjects, the peak cyclic GMP response to L-arginine was significantly correlated with the peak delta glucose/ delta insulin ratio response to L-arginine (r = .69, P < .001). Findings suggested that an impairment of endothelium-dependent renal vascular relaxation and a reduced sensitivity to insulin are present in patients with essential hypertension. A link may be present between the abnormality of the L-arginine/nitric oxide/cyclic GMP pathway and insulin resistance in patients with essential hypertension.

Arginine↗
PubMed1997

Nocturnal decline in blood pressure is attenuated by NaCl loading in salt-sensitive patients with essential hypertension: noninvasive 24-hour ambulatory blood pressure monitoring.

We investigated the effect of NaCl on the circadian blood pressure rhythm in patients with essential hypertension classified according to the presence or absence of salt sensitivity. We obtained 24-hour noninvasive ambulatory blood pressure measurements in 64 Japanese patients with mild to moderate essential hypertension who ate a low NaCl diet (50 mmol/d) for 1 week, followed by a high NaCl diet (340 mmol/d) for 1 week. Twenty-six patients whose mean blood pressure was increased more than 10% by NaCl loading were classified as salt sensitive. The remaining 38 patients were classified as salt resistant. The nocturnal decline in mean blood pressure was significantly smaller in salt-sensitive patients (8.3+/-1.0%) than in salt-resistant patients (11.5+/-0.9%) (P<.05) during a high NaCl diet but was similar in both groups during a low NaCl diet. There was no significant difference in the prevalence of the non-dipper pattern between groups on a low NaCl diet, but the prevalence of the non-dipper pattern was significantly higher in salt-sensitive patients than in salt-resistant patients on a high NaCl diet (0.57 versus 0.26, chi2=6.4; P=.02; odds ratio, 3.82). These findings suggest that the NaCl loading blunted the nocturnal decline in blood pressure in salt-sensitive patients but not in salt-resistant patients.

Blood Pressure↗
PubMed1997

Aging and severity of hypertension attenuate endothelium-dependent renal vascular relaxation in humans.

Endothelial dysfunction may be related to cardiovascular risk factors, such as aging, hypertension, and atherosclerosis. We investigated whether aging and hypertension independently alter endothelial function in the renal circulation in humans in the absence of abnormalities in lipid and glucose metabolism. L-Arginine (500 mg/kg over 30 minutes) was intravenously administered to 33 patients with essential hypertension and 35 normotensive subjects. The L-arginine-induced increases in renal plasma flow (10.1+/-0.8% versus 15.8+/-0.9%, P<.05) and plasma cGMP (53+/-4% versus 82+/-5%, P<.05) were significantly smaller in patients with essential hypertension than in the normotensive subjects. Multivariate stepwise regression analysis showed that age (P<.0002) and the mean blood pressure (P<.0001) were independently and negatively correlated with the renal plasma flow response to L-arginine. Age (P<.002), mean blood pressure (P<.0001), and male sex (P<.05) were independently correlated with the L-arginine-induced increase in plasma cGMP. The peak change in plasma cGMP was significantly correlated with the L-arginine-induced increase in renal plasma flow (r=.63, P<.001). These findings suggest that aging and hypertension may independently impair endothelium-dependent renovascular dilation and that this effect may be caused at least in part by a decrease in nitric oxide production.

Adult↗
PubMed1997

Effects of long-term low-dose macrolide administration on neutrophil recruitment and IL-8 in the nasal discharge of chronic sinusitis patients.

Effects of long-term low-dose macrolide administration were studied in patients with chronic sinusitis. Twelve patients with non-allergic chronic sinusitis were orally given 150 mg roxithromycin once a day without other treatments. The patients underwent computed tomography before and after the treatment, and paranasal sinus aeration was analyzed quantitatively. The number of neutrophils in the nasal smear was semiquantitatively assessed on a grading scale, and the IL-8 concentration in the nasal discharge was measured by enzyme immunoassay. The aeration of all four sinuses significantly improved, and recruited neutrophils and the IL-8 level in the nasal discharge were simultaneously reduced after the treatment. These findings suggest that long-term low-dose roxithromycin administration inhibits the positive feedback mechanism of neutrophil recruitment and IL-8 production by the recruited neutrophils, which is considered to be an essential cause of the prolongation of sinusitis.

Administration, Oral↗
PubMed1997

A case of leiomyosarcoma of the sphenoid sinus.

A 43-year-old man with a primary leiomyosarcoma of the left sphenoid sinus is presented. To our knowledge, this is an unusual case of leiomyosarcoma, which has never been reported in the literature. Accurate and safe diagnosis was obtained by an endonasal endoscopic approach with minimal tissue invasion.

Adult↗
PubMed1997

A case report of salivary duct carcinoma.

We present a 65-year-old man with an enlarged mass in the right parotid gland. A fine-needle aspiration cytology suspected Warthin's tumor. The ill-defined margin of the tumor in diagnostic imaging and unexpected clinical course of the occurrence of facial nerve paralysis suggested malignant neoplasm. The patient was treated with surgical resection of the primary site and neck following radiation therapy. Pathologic diagnosis was a salivary duct carcinoma. Difficulty in early diagnosis of this tumor may result in local extension, early metastasis to regional lymph nodes and distant sites, and death.

Adenocarcinoma↗
PubMed1997

A press-through-pack in the larynx.

A case of a 96-year-old male with a foreign body in the larynx is reported. The foreign body was a press-through-pack (PTP), a plastic packing for medicine, 16 mm x 16 mm x 3 mm in size. The PTP was safely removed from the larynx under general anesthesia.

Aged↗
PubMed1997

[Bladder carcinoma presenting with hypercalcemia: a case report].

A 47-year old woman was referred to our hospital with nausea, vomiting and the loss of body weight. Pelvic computed tomography and magnetic resonance imaging revealed an invasive bladder tumor on the left lateral wall, accompanied with calcification. Laboratory examination revealed marked hypercalcemia (20.6 mg/dl) and elevated serum parathyroid hormone-related protein-intact (29.9 pmol/l), which was apparently produced by the tumor. Treatment with pamidronate and colloid infusion resulted in normocalcemia. Anterior pelvic exenteration was performed. Histopathological diagnosis was transitional cell carcinoma > adenocarcinoma, G3, pT4pN2M0, stage IV. She died of cancer 7 months postoperatively.

Carcinoma, Transitional Cell↗
PubMed1997

[Evaluation of angiotensin I converting enzyme gene polymorphism in patients with essential hypertension and coronary artery disease].

We investigated the role of the insertion (I)/deletion(D) polymorphism in the angiotensin I converting enzyme (ACE) gene in the cardiovascular diseases. First, we studied 520 patients who had undergone coronary angiography: including 220 patients with acute myocardial infarction, 98 patients with effort angina pectoris (> 75% stenosis), 83 patients with vasospastic angina and 119 controls with normal coronary artery. There was no difference in the frequency of ACE gene I/D allele or genotype II, ID and DD among the four groups. Second, we studied the correlation between ACE gene I/D polymorphism and the clinical characteristics in patients with essential hypertension. The distribution of I/D allele and genotype were similar in 140 essential hypertensives and 83 normal controls. In patients with DD genotype, age at onset of hypertension was lower and left ventricular mass index was greater than those in patients with ID and II, although blood pressure levels and the severity of damage to other organs-were similar in the three groups. Further, 66 patients with essential hypertension were classified into 35 salt-sensitive and 31 salt-resistant patients according to changes in mean blood pressure during a week of low salt diet followed by a week of high salt diet. The frequency of I allele was significantly higher in the salt-sensitive group than in the salt-resistant group. In conclusion, ACE gene I/D polymorphism is not associated with coronary artery diseases. In patients with essential hypertension, the D allele was associated with early onset and left ventricular hypertrophy, while I allele was associated with salt sensitivity.

Age of Onset↗
PubMed1997

[Clinical evaluation of 2-mg granisetron tablet for nausea and vomiting induced by anticancer drugs including cisplatin].

The antiemetic effects on nausea and vomiting induced by anticancer drugs and safety of a 2-mg granisetron tablet were studied in cancer patients, particularly in the field of gynecology, who had been treated with anticancer drugs including cisplatin (CDDP) at 50 mg/m2 or more. The 1-mg granisetron tablet is already commercially available and used widely in clinical practice by oral administration of two tablets per dosage. In this investigation, the clinical efficacy, safety and usefulness of a 2-mg tablet, which can be taken more easily, were studied. The 2-mg granisetron tablet was judged to be "remarkably effective" or "effective" for nausea and vomiting in 22 (66.7%) of 33 patients. For safety, neither adverse experiences nor abnormal laboratory values were judged to be of clinical significance. The 2-mg granisetron tablet was considered "extremely useful" or "useful" in 22 (66.7%) of 33 patients. The above results confirmed the excellent antiemetic effect on nausea and vomiting induced by anticancer drugs including CDDP and the high degree of safety of a 2-mg granisetron tablet.

Adult↗
PubMed1997

[Predictive factors for development of hemolytic uremic syndrome (HUS) and early intensive treatments for prevention of HUS enterohemorrhagic Escherichia coli infection].

Predictive factors for the development of hemolytic uremic syndrome (HUS) were evaluated in 88 inpatients who suffered from enterohemorrhagic E. coli infections in the outbreak in Sakai, 1996. All in- and outpatients received oral or intravenous fosfomycin within acute phase of hemorrhagic colitis, and HUS complicated 1.4% of them. Persistence of bloody stools and diarrhea were longer in HUS patients than in non-HUS patients, but persistence of abdominal pain was not different in either group. Leukocytosis with leukocyte counts over 15,000/microliters and/or elevated CRP level over 2.0 mg/dl at admission, and fever and/or vomiting in the course of hemorrhagic colitis were more frequent in HUS patients than in non-HUS patients. Early intensive treatments including gammaglobulin, urinastatin, aspirin, and dipyridamole were employed in 34 high risk patients for prevention of HUS. These patients were estimated to be at risk of developing HUS because of incomplete HUS, nephropathy, elevated LDH level, thrombocytopenia, or age younger than two years old. These treatments were clinically effective.

Abdominal Pain↗