Search PubMed⌕ Search

Biomedical subjects

H Tada

Publications and source records attributed to H Tada.

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

Immunoliposome-mediated gene transfer into cultured myotubes.

We encapsulated marker genes, pRSV-lacZ or pRSV-luc, in immunoliposomes conjugated with antibody targeting laminin B2 in the basal lamina of myotubes. The immunoliposomes were incubated with matured non-proliferating myotubes differentiated from C2C12 myoblasts. We then evaluated the efficiency of gene transfection by measuring luciferase activity and beta-galactosidase staining. The immunoliposomes conjugated with the antibody specific for myotubes were three times as efficient as control immunoliposomes conjugeted with an antibody not specific for myotubes. However, the efficiency was no more than that by the cationic liposomes without the antibody. These results suggest that laminin B2 is not effective in enhancing the efficiency of gene transfection for non-proliferating myotubes. A specific antibody for surface antigen other than laminin B2 should be chosen in further studies.

Animals↗
PubMed2000

Enzyme immunoassay for autoantibodies to human liver-type arginase and its clinical application.

BACKGROUND: Arginase is an enzyme of the urea cycle, and one of the two isoenzymes is the liver-type enzyme. We examined serum autoantibodies to this liver-type enzyme in patients with hepatitis. METHODS: Antibodies to recombinant human liver-type arginase were measured by ELISA in 95 patients and 55 healthy controls. RESULTS: The mean absorbance values in the ELISA assays of patients with definite autoimmune hepatitis (n = 11; P <0.0001), probable autoimmune hepatitis (n = 31; P <0.0001), and hepatitis C (HCV; n = 20; P <0.01) were significantly different from those of healthy controls, but the values in patients with hepatitis B (HBV; n = 23) and other autoimmune diseases (n = 10) were not significantly different from those of healthy controls. When the cutoff was fixed at the upper 95th percentile of the absorbance value in healthy controls, positive reactions were found in 18.2%, 32.3%, 20.0%, 13. 0%, and 10.0% of patients with definite autoimmune hepatitis, probable autoimmune hepatitis, HCV hepatitis, HBV hepatitis, and other autoimmune diseases, respectively. All of these positive reactions were abolished by inhibition of serum with recombinant antigen. The specificity and sensitivity of this ELISA were 96% and 29%, respectively. The intraassay and interassay coefficients of variation were 2.3-7.5% and 9.8-11%, respectively. There was no relationship between these antibodies and anti-nuclear, anti-smooth muscle, or anti-cytochrome P450IID6 antibodies. CONCLUSIONS: The ELISA for anti-liver-type arginase autoantibody improved the detectability of autoimmune hepatitis when compared with established assays for liver-specific autoantibodies.

Arginase↗
PubMed2000

Serum dehydroepiandrosterone, dehydroepiandrosterone sulfate, and pregnenolone sulfate concentrations in patients with hyperthyroidism and hypothyroidism.

BACKGROUND: Dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEA-S) have been suggested to have protective effects against cardiovascular disease, cancer, immune-modulated diseases, and aging. We examined serum concentrations of DHEA, DHEA-S, and pregnenolone sulfate (PREG-S) in patients with thyroid dysfunction. METHODS: Steroids extracted with methanol from serum sample were separated into an unconjugated fraction (DHEA) and a monosulfate fraction (DHEA-S and PREG-S), using a solid-phase extraction and an ion-exchange column. After separation of unconjugated steroids by HPLC, the DHEA concentration was measured by enzyme immunoassay. The monosulfate fraction was treated with arylsulfatase, and the freed steroids were separated by HPLC. The DHEA and PREG fractions were determined by gas chromatography-mass spectrometry, and the concentrations were converted into those of DHEA-S and PREG-S. RESULTS: Serum concentrations of DHEA, DHEA-S, and PREG-S were all significantly lower in patients with hypothyroidism (n = 24) than in age- and sex-matched healthy controls (n = 43). By contrast, in patients with hyperthyroidism (n = 22), serum DHEA-S and PREG-S concentrations were significantly higher, but the serum DHEA concentration was within the reference interval. Serum concentrations of these three steroids correlated with serum concentrations of thyroid hormones in these patients. Serum albumin and sex hormone-binding globulin concentrations were not related to these changes in the concentration of steroids. CONCLUSIONS: Serum concentrations of DHEA, DHEA-S, and PREG-S were decreased in hypothyroidism, whereas serum DHEA-S and PREG-S concentrations were increased but DHEA was normal in hyperthyroidism. Thyroid hormone may stimulate the synthesis of these steroids, and DHEA sulfotransferase might be increased in hyperthyroidism.

Adult↗
PubMed2000

[Arteriovenous fistula associated with Staphylococcus aureus sepsis in a patient with Rendu-Osler-Weber syndrome].

A 58-year-old man with a history of cerebral infarction and bleeding due to duodenal ulcer was admitted with fever and arthralgia. Methicillin-sensitive Staphylococcus aureus (MSSA) was isolated from his peripheral blood. Bacteremia with MSSA was diagnosed, and antibiotic therapy was started. However, chest X-ray films and computed tomographic scans disclosed mass shadows in both lungs accompanied by dilated vascular markings. Pulmonary arteriography and magnetic resonance angiography revealed the existence of arteriovenous fistulas in both lungs. Ga scintigraphy disclosed a hot spot in the left lower lobe, consistent with the location of one fistula. This indicated that the fistula might be the focus of MSSA sepsis. Because the patient also had telangiectasia in his gastric mucosa, oral cavity, and nasal cavity, he was given a diagnosis of Rendu-Osler-Weber syndrome.

Arteriovenous Fistula↗
PubMed2000

[Significance of exercise-induced ST segment depression in patients with myocardial infarction involving the left circumflex artery: evaluation by exercise thallium-201 myocardial single photon emission computed tomography].

The significance of exercise-induced ST segment depression in patients with left circumflex artery involvement was investigated by comparing exercise electrocardiography with exercise thallium-201 single photon emission computed tomography(Tl-SPECT) and the wall motion estimated by left ventriculography. Tl-SPECT and exercise electrocardiography were simultaneously performed in 51 patients with left circumflex artery involvement(angina pectoris 30, myocardial infarction 21). In patients with myocardial infarction, exercise-induced ST depression was frequently found in the V2, V3 and V4 leads. In patients with angina pectoris, ST depression was frequently found in the II, III, aVF, V5 and V6 leads. There was no obvious difference in the leads of ST depression in patients with myocardial infarction with ischemia and without ischemia on Tl-SPECT images. In patients with myocardial infarction, the lateral wall motion of the infarcted area evaluated by left ventriculography was more significantly impaired in the patients with ST depression than without ST depression(p < 0.01). Exercise-induced ST depression in the precordial leads possibly reflects wall motion abnormality rather than ischemia in the lateral infarcted myocardium.

Aged↗
PubMed2000

[Endocrine diseases and aging].

Age dependent perturbations to endocrine systems are overviewed and the interpretation of the results of endocrinological tests for clinical decision are discussed referring to thyroid diseases as an example. The endocrine functions that are essential to life, such as adrenal and thyroid functions, show minimal change by aging. Their basal levels alter little, although production and degradation of hormones decrease. Some part of elderly persons show lower levels of triiodothyronine, which may, however, reflect deterioration of their physical condition and should not be overlooked as an age dependent change. Some endocrine function, such as gonadal function and calcium metabolism obviously reveal age dependent physiological change and their reference ranges for elderly persons are set separately. Thus, reference levels and clinical decision for endocrinological tests should be dependent on the properties of individual endocrine system.

Adult↗
PubMed2000

Effect of epinephrine and combination treatment of epinephrine and heat on melanoma cell lines. Study of cytotoxicity and kinetics of 72-kD stress protein.

To elucidate the effect of epinephrine and the combination with heat on malignant cells, using two melanoma cell lines, HM6KO and G361, we have examined the cytotoxicity and induction of 72-kD stress protein (HSP72) after the treatments. After epinephrine treatment, in both cell lines, cell survival rates decreased gradually in a concentration-dependent manner. After the combination treatment, cell survival rates decreased more than those when two treatments were done separately. The cytotoxicity of epinephrine was more enhanced in G361 than in HM6KO by heat. After epinephrine treatment, in both cell lines, the level of HSP72 did not elevate. After combination treatment, in HM6KO, the level of HSP72 were higher than those of heat alone. In G361, the kinetics of HSP72 level was similar to that of heat alone. These results suggest that epinephrine has a cytotoxicity to melanoma cells and the cytotoxicity is enhanced by the combination. In addition, it is probable that epinephrine does not have HSP72 inducibility in HM6KO and G361, and the different kinetics of HSP72 between the cell lines in the combination treatment may play an important role to determine the degree of enhancement.

Adrenergic Agonists↗
PubMed2000

[Depression of serum pyridoxal levels in theophylline-related seizures].

In order to study whether a theophylline-related seizure is caused by a decrease in serum vitamin B6, serum pyridoxal (PAL) levels were measured in children with bronchial asthma treated with theophylline. The serum PAL levels of asthmatic children (n = 31) treated with theophylline were significantly lower than those of control subjects (n = 21). Moreover, we evaluated PAL levels in four subjects within twenty-four hours after a seizure with or without fever. The level was low in three of the four. These results suggest that the decrease in PAL levels caused by theophylline may lower the seizure threshold.

Adolescent↗
PubMed2000

[Anatomical variations of Koch's triangle in patients with atrioventricular nodal reentrant tachycardia: usefulness of the left anterior oblique view].

OBJECTIVES: Several anatomical distances of Koch's triangle including the ablation site were measured and correlated with clinical features and slow pathway potentials in patients with atrioventricular nodal reentrant tachycardia to improve the avoidance of complete atrioventricular block. METHODS: Sixty consecutive patients (24 males and 36 females, mean age 47 +/- 12 years) with successfully eliminated atrioventricular nodal reentrat tachycardia were studied. The distances between the His-bundle area and the base of the coronary sinus ostium (Dis HBE-CS) and the distances between the successful ablation site and the base of the CS ostium (Dis SP-CS) were measured in both right anterior oblique and left anterior oblique views, and used to define the dimensions of Koch's triangle. The relationship between the slow pathway potentials at the successful ablation site and anatomical distances was estimated. RESULTS: The Dis HBE-CS in the right anterior oblique view was negatively correlated with patient age (r = -0.759, p < 0.001) and body mass index. In contrast, the Dis HBE-CS in the left anterior oblique view had only weak correlations with patient age and body mass index. The mechanism of the short Dis HBE-CS in the right anterior oblique view in elderly obese patients tended to change the shape of the tricuspid annulus from a circle to an ellipse, compressed by the ascending aorta and diaphragma. The Dis SP-CS in the right anterior oblique view associated with the low frequency potential (Haissaguerre's slow pathway potential) was longer than that associated with the high frequency potential (Jackman's slow pathway potential). CONCLUSIONS: Elderly obese patients had shorter distances between the proximal His-bundle area and the base of the coronary sinus ostium in the right anterior oblique view. In contrast, the Dis HBE-CS in the left anterior oblique view was not so narrow. Therefore, slow pathway ablation can be performed safely without complicated complete atrioventricular block, using both the slow pathway potential guided approach and the anatomical guided approach, especially in the left anterior oblique view.

Adolescent↗
PubMed2000

[Psoas abscess caused by nephrolithiasis with perirenal abscess complicated with pleural effusion].

Left pleural effusion was found in a 60-year-old woman in whom chest radiography performed during a physical check up revealed no abnormality. Abdominal CT scanning revealed an abscess in the left psoas muscle. The psoas abscess was eliminated temporarily by drainage under ultrasonographic guidance and by the administration of antibiotics, but recurred one month later. A stag-horn renal stone considered to have caused the psoas abscess by formation of a perirenal abscess was eliminated by left nephrectomy. It is suggested tentatively that the psoas abscess might have been the cause of the pleural effusion.

Abscess↗
PubMed2000

[Thoracoscopic pleural biopsy under local anesthesia using a 2 mm laparoscope].

Thoracoscopy is indicated in patients with undiagnosed effusion after conventional methods. It has been usually performed under general anesthesia or using a thoracoscope with a thoracoscope with a diameter over 5 mm. However, it is an invasive diagnostic technique. We evaluated the feasibility of thoracoscopic pleural biopsy under local anesthesia using a 2 mm laparoscope. Six patients with a pleural effusion of unknown etiology after conventional methods, underwent thoracoscopy under local anesthesia. A 2 mm laparoscope and biopsy forceps (2 mm Minisite, United States Surgical Corp., USA) was used in all patients. Pleural fluid was removed, and the thoracic cavity was inspected. Thoracoscopic intercostal blocks were performed with 1% lidocaine, and then a biopsy was performed. The biopsy specimen was sent for histopathology. Three patients were shown to have carcinomatous pleurisy, two of them with localized lesions less than 10 mm. In the remaining three patients, non-specific diagnoses were made, but long-term follow-up revealed no malignant pleural disease. Although the pictures obtained using a 2 mm laparoscope were inferior in quality, they were adequate for the detection of malignant lesions in the pleural cavity. There were no procedure-related complications. These findings suggest that thoracoscopy using a 2 mm laparoscope is (1) a useful diagnostic tool in cases of pleural malignancy; (2) a minimally invasive method with the advantage of being easily performed under local anesthesia. Thus, thoracoscopic pleural biopsy using a 2 mm laparoscope appears to be useful for undiagnosed pleural effusion.

Anesthesia, Local↗
PubMed1999

Low-Temperature Synthesis of Nanometer-Sized Crystalline TiO2 Particles and Their Photoinduced Decomposition of Formic Acid.

Anatase TiO2 particles with an average size of 2.7 nm in an as-grown state were obtained below 373 K from an H2O-EtOH mixed solution of TiOSO4 by a facile liquid phase method. The volume ratio of H2O to EtOH was revealed to be the key for crystallinity of the particles. The as-grown particles prepared from the H2O-EtOH solution (H2O/EtOH (mL/mL) = 150/100) showed a high photoreactivity in the TiO2 photoinduced decarboxylation of HCOOH under a deaerated condition. In contrast, under an aerated condition, the rate of the reaction increased with an increase in calcining temperature (Tc) due to the improvement of anatase crystallinity, going through a maximum at Tc = 873 K. Copyright 1999 Academic Press.

Journal Article↗
PubMed1999

Processing and juxtacrine activity of membrane-anchored betacellulin.

Betacellulin (BTC) was originally isolated as a secreted growth factor from a mouse pancreatic beta-tumor cell line, whereas the cDNA sequence predicts that BTC is synthesized as a larger transmembrane protein. In the present study, we have characterized the membrane-anchored forms of BTC, using Chinese hamster ovary (CHO) cells, mouse fibroblast A9 cells, and a human breast cancer cell line MCF-7, all of which were stably transfected with human BTC cDNA. A9 and MCF-7 transfectants produced membrane-anchored BTC isoforms of 21, 25, 29, and 40 kDa on the cell surface, as well as a secreted BTC isoform. CHO transfectants secreted little BTC but accumulated the membrane-anchored isoforms. The cleavage of the membrane-anchored forms to release a secreted from of BTC was not enhanced by biological mediators such as a phorbol ester, which stimulates the cleavage of other membrane-anchored growth factors. The membrane-anchored forms of BTC expressed on the transfected cells induced the insulin production and/or promoted the growth in subclones of AR42J rat pancreatic cells. These results suggest that the membrane-anchored BTC can function as a juxtacrine factor in regulating the growth and differentiation of pancreatic endocrine cells.

3T3 Cells↗
PubMed1999

Augmentation of vessel squeezing at coronary-myocardial bridge by nitroglycerin: study by quantitative coronary angiography and intravascular ultrasound.

BACKGROUND: Nitroglycerin is known to augment vessel wall squeezing at the site with coronary-myocardial bridging (CMB). This study was designed to define the mechanism of nitroglycerin-induced augmentation of CMB in clinical settings. METHODS: We analyzed nitroglycerin reactivity at the site with CMB in 39 patients. Maximal and minimal diameters of CMB during a cardiac cycle were measured by quantitative angiography before and after intracoronary administration of 250 microgram nitroglycerin. In 15 patients, CMB sites were observed by intravascular ultrasound to determine the intimal thickness and the time-serial change in vessel area. RESULTS: Before nitroglycerin, CMB was demonstrated with angiography in 25 patients, and the remaining 14 patients showed CMB after nitroglycerin. The maximal diameter during diastole increased from 1. 4 +/- 0.4 mm to 1.9 +/- 0.4 mm after nitroglycerin, whereas the minimal diameter during systole decreased from 1.0 +/- 0.4 mm to 0.7 +/- 0.4 mm (P <.01). Thus nitroglycerin augmented the percent vessel narrowing during systole from 24% +/- 21% to 65% +/- 16% (P <.01). Under these conditions, intravascular ultrasound showed the reduction of the cross-sectional area of the sites with CMB by -38% +/- 16% (P <.01) during systole, and this phenomenon continued to early diastole (-30% +/- 16%). The intimal thickness was 0.32 +/- 0. 10 mm, which suggests the absence of atherosclerotic disease at CMB sites. CONCLUSIONS: These results indicate that nitroglycerin-induced augmentation of the percent narrowing of CMB can be derived from further systolic compression of the vessel lumen as well as diastolic expansion, probably because of the increase in vessel compliance after nitroglycerin. We suggest that the delayed dilation of coronary lumen during the early diastole may contribute to the occurrence of myocardial ischemia.

Adult↗