Search PubMed⌕ Search

Biomedical subjects

M Matsuda

Publications and source records attributed to M Matsuda.

At least 757 records · Page 42Linked to original sources

Sulfonylurea enhances insulin-induced acetyl coenzyme A carboxylase activity in rat adipocytes.

The effect of sulfonylurea on the activity of acetyl-coenzyme A carboxylase, a rate limiting enzyme of lipogenesis, was investigated using isolated rat adipocytes. Insulin significantly increased the enzyme activity by 170% of the control level, while glucagon and epinephrine decreased the activity of the enzyme by 53% and 64% of the control, respectively. In the presence of tolbutamide (10(-3) M) or glibenclamide (10(-6) M), a significant potentiation of insulin action was found in adipocytes. In addition, sulfonylurea restored the activity of acetyl-CoA carboxylase reduced by glucagon or epinephrine to the control level. Sulfonylurea enhancement of the acetyl-CoA carboxylase activity may offer one possible explanation for a mechanism of antilipolytic action of the drug in adipocytes.

Acetyl-CoA Carboxylase↗

Effects of digoxin, propranolol, and verapamil on exercise in patients with chronic isolated atrial fibrillation.

STUDY OBJECTIVE: The aim was to evaluate the effects of digoxin, propranolol, and verapamil on exercise in patients with chronic isolated atrial fibrillation. DESIGN: Patients with chronic isolated atrial fibrillation underwent maximal exercise testing before and after the administration of digoxin, propranolol, or verapamil. Heart rate, oxygen uptake and oxygen pulse were observed at rest, at gas exchange anaerobic threshold, and at peak exercise. SUBJECTS: The subjects were 10 patients (aged 48-78 years, mean age 60, SD 9, years) with chronic isolated atrial fibrillation. MEASUREMENTS AND MAIN RESULTS: During exercise without medication, the heart rate was 85 (SD 8) beats.min-1 at rest, 127(19) at the level of anaerobic threshold, and 175(17) at peak exercise. With digoxin, heart rate was reduced to 75(9) beats.min-1 at rest (control v digoxin, p less than 0.01). However, reduction of heart rate was not seen at anaerobic threshold or at peak exercise. With propranolol, heart rate was 63(7) beats.min-1 at rest, 99(16) at anaerobic threshold, and 138(28) at peak exercise (control v propranolol, all p less than 0.01). Heart rate with verapamil was 70(13) beats.min-1 at rest, 107(30) at anaerobic threshold, and 138(28) at peak exercise (control v verapamil, p less than 0.05 at rest and at anaerobic threshold, p less than 0.01 at peak exercise. Neither digoxin, nor propranolol, nor verapamil changed the oxygen uptake during exercise. Without medication, oxygen pulse was 6.5(2.0) ml.beat-1 at anaerobic threshold and 7.7(2.1) ml.beat-1 at peak exercise. With digoxin, the change of oxygen pulse, versus without medication, was not significant at rest or at anaerobic threshold but was increased at peak exercise, at 8.3(2.1) v 7.7(2.1) ml.beat-1, p less than 0.05. With propranolol, oxygen pulse was increased to 8.2(1.9) ml.beat-1 at anaerobic threshold and 9.2(2.3) ml.beat-1 at peak exercise (control v propranolol, both p less than 0.01). With verapamil, oxygen pulse was increased to 8.7(1.8) ml.beat-1 at anaerobic threshold and 10.0(2.1) ml.beat-1 at peak exercise (control v verapamil, both p less than 0.01). CONCLUSIONS: Digoxin was effective in reducing heart rate at rest, but failed to reduce it during exercise. Propranolol and verapamil reduced heart rate at all levels of exercise as well as at rest. Oxygen uptake during exercise (total exercise capacity) was not reduced with propranolol or verapamil; this was thought to have been accomplished by an increased oxygen pulse.

Aged↗

Synthesis of protein C in human umbilical vein endothelial cells.

By monitoring the activation of protein C and the regulation of factor Xa-catalyzed thrombin formation by the activated protein C (APC) on the surface of human umbilical vein endothelial cells (HUVEC), we found that functional protein C was synthesized in cultured HUVEC and expressed thereon in the presence of vitamin K. Furthermore, without exogenously added protein S, time-dependent and saturable accumulation of APC (20 fmol APC/10(5) cells) on the surface of HUVEC was observed. During prothrombin activation by the complex of membrane-bound factor Xa and endogenous factor Va formed on the surface of HUVEC, APC was generated, and the rate of thrombin formation decreased. Treatment of HUVEC with an antibody that inhibits the APC-catalyzed inactivation of endogenous factor Va clearly quenched the activity of surface-associated APC. Immunostaining of HUVEC with a horseradish peroxidase (HRP)-conjugated antibody that solely recognizes human protein C confirmed the presence of protein C on the surface of HUVEC. Northern blot analysis revealed that an about 1.8 kb mRNA species derived from HUVEC was hybridized with 32P-labeled protein C cDNA, as in the case of those from HepG2, which are known to synthesize normal protein C. The increase in the amount of protein C mRNA in HUVEC in parallel with cell growth provided supporting evidence for the synthesis of protein C during the culture of HUVEC. These results indicate that blood coagulation is regulated by endogenously generated and activated protein C, together with or without protein S, through inactivation of factor Va on the surface of endothelial cells.

Antibodies, Monoclonal↗

Radionuclide ventriculographic quantitation of left ventricular dimensions. Comparison to echocardiography.

Left ventricular internal cavity dimensions (LVID) were determined from radionuclide ventriculographic (RNVG) studies using a spatial calibration algorithm and visually defined edges and were compared to the results from two-dimensional echocardiography. Routine clinical cases were used with no additional views and no attenuation or scatter correction. In an initial set of 21 patients, mean RNVG LVID was 5.7 +/- 1.1 (mean +/- 1 S.D.) cm compared to 5.3 +/- 1.0 cm for echocardiography. In a prospective validation of the regression equations derived in the initial set of patients, regression-corrected RNVG results were within 5 mm of those determined echocardiographically in 18/22 patients and the mean LVID values were the same. Quantitative estimation of LVID by RNVG is simple, rapid, and reproducible. Systematic overestimation of dimensions compared to echocardiography can be corrected using a regression equation.

Algorithms↗

Plasma concentrations of endothelin-1 and endothelin-3 are altered differently in various pathophysiological conditions in humans.

Several studies have indicated that endothelin-1 (ET-1) and endothelin-3 (ET-3) are produced by different cells. Although ET-1 is produced by vascular endothelial cells, these cells do not produce ET-3. In the present study, we measured plasma concentrations of both ET-1 and ET-3 by sandwich-enzyme immunoassays which we developed recently in patients on chronic hemodialysis, age-matched normal subjects, patients with acute myocardial infarction, patients undergoing surgery, and healthy subjects before and after strenuous endurance exercise. Plasma levels of ET-1 and ET-3 were demonstrated to be altered differently in the above conditions in humans. Although the exact origin of circulating endothelins has yet to be elucidated, the different alterations of plasma levels suggest that both ET-1 and ET-3 may play different roles in physiological and/or pathophysiological responses to various conditions in humans.

Adult↗

Sensitivity and specificity of lung cancer screening in Osaka, Japan.

Sensitivity and specificity were evaluated for lung cancer screening conducted at 8 municipalities in Osaka Prefecture during 1981-1985. As a screening policy, all attendants were examined by miniature chest X-ray, and the high-risk group, defined as those who smoked cigarettes or had bloody sputum, were also examined by 3-day pooled sputum cytology. A total of 33,599 screening tests for 19,028 people who were 40 years old or more at the time of screening were conducted, resulting in 33,490 miniature chest X-ray examinations for 18,992 people and 11,420 sputum cytologies for 7,070 people. As a result, 43 lung cancer cases were detected. All test-negatives were followed by means of record linkage with the files of the Osaka Cancer Registry up to the end of 1986. There were 24 cases who were diagnosed as having lung cancer without having given a positive screening result in 1981-1986. Assuming the preclinical detectable phase of lung cancer to be one year uniformly, the sensitivity and specificity for the lung cancer screening were estimated to be 71.6% and 95.3%, respectively. The feasibility of increasing the sensitivity is discussed.

Adult↗

Lung cancer risk among exsmokers.

Lung cancer risk among exsmokers according to years since cessation of smoking was assessed by means of a case-control study. The case series consisted of 1,052 lung cancer patients who were newly diagnosed and admitted to eight hospitals in Osaka in 1986-88. Smoking histories were compared with those of 1,111 controls admitted to the same hospitals during the same period without any diagnosis of smoking-related disease. The odds ratio of lung cancer for exsmokers compared to current smokers was estimated to be 0.90, 0.50, 0.51, 0.59, 0.48 and 0.29, for 1-4, 5-9, 10-14, 15-19, 20-24 and greater than or equal to 25 years after cessation of smoking, respectively. Risk reduction appeared to be greater for those who smoked less than the 1200 cigarette index, compared to those who smoked more. In classification according to histologic type, small cell and large cell carcinoma showed a rapid decrease compared to adenocarcinoma, while squamous cell carcinoma showed an intermediate pattern. Quantitative estimates for reduction of lung cancer risk among exsmokers can be used for projecting lung cancer incidence in the future, by assuming future trends of smoking prevalence, as well as for health education among individual smokers.

Aged↗

In vitro antibacterial activity of a new quinolone, NM394.

NM394 is a new 6-fluoroquinolone antibacterial agent with a tricyclic structure which has a bridge that connects the N-1 and C-2 positions of the quinolone. The antibacterial activity of NM394 against clinical isolates of staphylococci, streptococci, enterococci, members of the family Enterobacteriaceae, and Pseudomonas aeruginosa was equal to or one-half that of ciprofloxacin. NM394 was as active as ofloxacin against gram-positive bacteria and was two to eight times more active against gram-negative bacteria, including P. aeruginosa. NM394 was two to eight times more active than enoxacin against gram-positive and gram-negative bacteria. The MICs of NM394 against Escherichia coli and P. aeruginosa at pH 5.5 were reduced 4 to 16 times compared with those at pH 7.0. Ciprofloxacin, ofloxacin, and enoxacin were 2 to 32 times less active against these two bacteria and Staphylococcus aureus at an acidic pH than they were at pH 7.0. In the presence of 5 mM Mg2+, the MICs of all of these drugs increased 2 to 32 times, but they were only slightly affected by 5 mM Ca2+, type of medium, serum, or size of inoculum. NM394 showed potent bactericidal activity and inhibited the supercoiling activity of E. coli DNA gyrase. The in vitro antibacterial profile of NM394 is similar to that of other 6-fluoroquinolones.

Anti-Infective Agents↗

In vivo evaluation of NM441, a new thiazeto-quinoline derivative.

NM441 is a lipophilic prodrug of a new thiazeto-quinoline carboxylic acid derivative NM394, and when it is administered orally it is readily absorbed and hydrolyzed to its parent compound. After oral administration of NM441 at a dose of 20 mg/kg to dogs, the peak concentration of NM394 in plasma was 2.39 micrograms/ml, whereas it was 0.63 micrograms/ml for NM394 administered alone. The in vivo activity of NM441 was compared with those of ciprofloxacin, ofloxacin, and enoxacin in mouse protection studies. NM441 was as effective as ofloxacin and was twice as effective as ciprofloxacin against systemic infection with Staphylococcus aureus. Against infections with streptococci, NM441 was two to three times as effective as ofloxacin and five times as effective as ciprofloxacin. Against infection with Escherichia coli, NM441 was as effective as ciprofloxacin and ofloxacin, but against infections with Klebsiella pneumoniae, Serratia marcescens, and Pseudomonas aeruginosa, NM441 was two to four times as effective as ciprofloxacin and ofloxacin. NM441 was three to seven times as effective as enoxacin in systemic infections. Against urinary tract infections with E. coli, NM441 reduced the number of bacterial CFU per gram of kidney by 1 to 2 log10 more and, with P. aeruginosa, by 1 to 6 log10 more than did ciprofloxacin and ofloxacin. Against respiratory tract infections with K. pneumoniae, NM441 was as effective as ofloxacin and was twice as effective as ciprofloxacin.

Administration, Oral↗

Identification of domains of the v-crk oncogene product sufficient for association with phosphotyrosine-containing proteins.

The oncogene product of the avian sarcoma virus CT10, P47gag-crk, contains the SH2, SH2', and SH3 domains and binds proteins in a phosphotyrosine (ptyr)-dependent manner. In this study, we have determined the region of P47gag-crk essential for binding to ptyr-containing proteins. Mutant P47gag-crk proteins expressed in Escherichia coli that have the intact SH2 and SH2' regions retained the capacity to bind ptyr-containing proteins obtained from cells transformed by crk and src. The deletion of SH2 resulted in the loss of binding activity. Other mutants that have altered SH2 or SH2' bound few, if any, of the ptyr-containing proteins. Those mutants that bound ptyr-containing proteins associated with tyrosine kinase activity. We also found that polypeptides containing SH2, SH2', and SH3 of p60v-src and p60c-src associated with ptyr-containing proteins from crk-transformed cells. Thus, the SH2 and SH2' domains of P47gag-crk are responsible for their binding to ptyr-containing proteins.

Animals↗

Comparison of the effects of intraocular irrigating solutions on the corneal endothelium in intraocular lens implantation.

We conducted a randomised prospective controlled study to determine the effects of a glucose glutathione bicarbonate solution (BSS Plus) and a citrate acetate bicarbonate solution (S-MA2) on the corneal endothelium in patients undergoing extracapsular cataract extraction with posterior chamber lens implantation. One eye of each patient was randomly assigned to receive BSS Plus, and the other eye to receive S-MA2. BSS Plus caused significantly less corneal swelling on the first postoperative day than did S-MA2. There was no difference between the two solutions in their effect on corneal thickness one week and one month postoperatively. Computer assisted morphometric analysis of wide-field specular microscopic photographs demonstrated minimal changes in endothelial morphological characteristics in the eyes irrigated with BSS Plus. By comparison S-MA2, caused a significant loss of endothelial cells and a marked reduction in the figure coefficient. These results indicated that BSS Plus has a clinical advantage over S-MA2 with respect to the corneal endothelium.

Aged↗

Orbital fractures: surface coil MR imaging.

Twenty-six patients with orbital fractures diagnosed with plain radiography and computed tomography were examined with surface coil magnetic resonance (MR) imaging. Fifteen patients had blow-out fractures, and 11 had maxillofacial complex fractures. In all patients with blow-out fractures, the location of the fracture was precisely indicated by the presence of prolapsed orbital fat. Incarceration of the extraocular muscle or orbital fat was correctly diagnosed with MR imaging, which was less sensitive in depicting maxillofacial fractures but was useful in assessment of soft-tissue involvement. Postoperative follow-up MR studies provided valuable information about the cause of motility impairment. While T1-weighted images are useful for the detection of the fracture site, both T1- and T2-weighted images are usually necessary for evaluating soft-tissue lesions. The results of this study indicate that surface coil MR imaging is an important adjunct procedure in the diagnosis and treatment of orbital fractures.

Adolescent↗

Neuropeptide-Y-immunoreactive chief cells in the carotid body of young rats.

The immunolight- and electron-microscopic study revealed neuropeptide Y (NPY) immunoreactivity in the chief cells and a few nerve fibers of the carotid body of young rats. NPY-immunoreactive chief cells were often seen as a single cell or a group of a few chief cells in the carotid body of young rats. The immunoreaction deposits were mainly seen in the dense-cored vesicles and diffusely in the cytoplasm of the chief cells. These findings suggest that NPY may be stored in the core of granules of the chief cells of the carotid body in young rats.

Animals↗

Comparison of lumbar flank approach and transperitoneal approach for radical nephrectomy.

A retrospective analysis based on Robson's tumor stage classification was performed on 56 patients with renal cell carcinoma who had undergone radical nephrectomy through a lumbar flank approach and 35 who had through a transperitoneal approach. The 5-year survival rates of patients with nephrectomy through the lumbar approach for Robson's stage 1, stage 2 and stage 3 were, respectively, 93.1, 70.4 and 60.0%. In comparison, the respective 5-year survival rates of patients with nephrectomy through the transperitoneal approach for Robson's stage 1, stage 2 and stage 3 were 90.5, 72.2 and 25.0%. As a result, there was no significant difference in survival rates between the two surgical procedures for any of the three Robson's stages. It is further suggested that the lumbar flank approach for radical nephrectomy does not result in poorer prognosis than does the transperitoneal approach, though transperitoneal and thoracoabdominal approaches have been generally recommended.

Adolescent↗

Effects of dietary konjac mannan on serum and liver cholesterol levels and biliary bile acid composition in hamsters.

We studied the effect of dietary konjac mannan on serum and liver cholesterol levels and biliary bile acid composition in hamsters. In hamsters fed a control diet supplemented with konjac mannan for 6 weeks, serum and liver cholesterol levels were decreased significantly compared to hamsters fed the control diet. Addition of konjac mannan to the cholesterol-enriched diet reduced the elevation of serum cholesterol caused by feeding cholesterol. However, the absorption of cholesterol from the intestine was not changed between the four groups. The increase in the proportion of chenodeoxycholic acid in biliary bile acids was significantly enhanced in the hamsters fed both cholesterol and konjac mannan compared to hamsters fed the control diet. The change of the bile acid composition may suggest that konjac mannan inhibits the intestinal absorption of bile acids.

Animals↗

Woodfordin D and oenothein A, trimeric hydrolyzable tannins of macro-ring structure with antitumor activity.

Two new antitumor trimeric hydrolyzable tannins, woodfordin D (5) and oenothein A (13), were isolated from the dried flowers of Woodfordia fruticosa, and their macrocyclic structures, which have a novel constituent unit (woodfordinoyl group) connecting the monomers, have been elucidated on the basis of spectral and chemical evidence. Oenothein A (13) was also isolated from the leaves of Oenothera biennis.

Antineoplastic Agents, Phytogenic↗