Biomedical subjects

M Matsuda

Publications and source records attributed to M Matsuda.

At least 1,153 records · Page 64Linked to original sources

PubMed1985

Effects of intraocular irrigating solutions on the corneal endothelium after in vivo anterior chamber irrigation.

We used wide-field specular microscopy and corneal pachymetry to evaluate the effect of anterior chamber irrigation with BSS and BSS Plus on the corneal endothelium of cats. Endothelial changes were quantitated by computerized morphometric analysis of individual cells. After short-term (15 and 30 minutes) and long-term (one and two hours) irrigation, endothelial cell density remained unchanged. Corneal thickness increased significantly in the BSS group after one hour of irrigation. BSS Plus caused minimal changes in endothelial morphologic characteristics regardless of the irrigation time. By comparison, BSS caused a significant increase in the coefficient of variation of cell area (polymegethism) and a decrease in the percentage of hexagonal cells (pleomorphism). These changes were more prominent after prolonged irrigation. The morphologic changes caused by BSS irrigation are indicative of a stressed endothelial monolayer that may be more susceptible to additional surgical trauma.

Acetates↗

PubMed1985

Fibrinogen Kawaguchi: an abnormal fibrinogen characterized by defective release of fibrinopeptide A.

A congenital dysfibrinogenemia was found in a 32-year-old asymptomatic female and her immediate family. The propositus, apparently a heterozygote for the abnormality, characteristically showed defective release of fibrinopeptide A from half of her fibrinogen molecules. No fibrinopeptide A was cleaved off from the isolated abnormal molecule by thrombin or snake venoms (Reptilase and Ancrod) as evidenced by radioimmunoassay, high performance liquid chromatography and determination of the NH2-terminal amino acids. The abnormal fibrinogen formed a solid gel solely by the release of fibrinopeptide B upon incubation with thrombin. We provisionally designate this abnormal fibrinogen as "Fibrinogen Kawaguchi", although possible identity with other abnormal fibrinogens is not excluded.

Adult↗

PubMed1985

Comparison of the corneal endothelium in an American and a Japanese population.

We compared the corneal endothelial morphology between an age-matched population of American and Japanese persons. Endothelial specular photographs were subjected to a computer-assisted morphometry of the area and shape of individual cells. The endothelium in the Japanese population showed a significantly higher cell density when compared with an age-matched American population. However, there was no difference in the degree of variations in cell area and cell shape between the two populations. The results suggest that higher endothelial cell density in the Japanese population could be related to the lower incidence of aphakic bullous keratopathy in the Japanese population.

Adolescent↗

PubMed1985

Long-term morphologic changes in the endothelium of transplanted corneas.

In a group of 17 patients, we studied the endothelial morphology and thickness of the central cornea yearly for five years after penetrating keratoplasty. The endothelial photographs were analyzed with a computerized digitizer to determine the area and shape of individual cells. The endothelial cell density decreased rapidly during the first two years postoperatively (59.4%), after which cell loss occurred at a considerably slower rate (3.5% of the preoperative cell count per year). During the observation period, the coefficient of variation in cell area stayed relatively constant (30%), implying that individual cells enlarge proportionally to their areas when spreading. The percentage of hexagonal cells and figure coefficient for the donor corneas were 60.5% and 0.8774, respectively. When the corneal thickness returned to normal two months after surgery, the endothelium showed a significant decrease in both measurements (48.2% and 0.8708, respectively), indicating a definite disruption of the normal hexagonal pattern. Between two months and two years postoperatively, both measurements gradually returned to normal. These results suggest that termination of endothelial cell loss from the central graft might be closely associated with the reestablishment of the normal hexagonal cellular pattern.

Adult↗

PubMed1985

Corneal endothelial morphology after anterior chamber lens implantation.

The morphologic features of the corneal endothelium were investigated by means of regional wide-field specular microscopy and computer-assisted morphometry in 13 eyes of nine patients who had undergone intracapsular cataract extraction with anterior chamber lens implantation more than one year previously. The endothelial cells in these patients demonstrated a significant increase in cellular elongation and the coefficient of variation in mean cell area and a significant decrease in the percentage of hexagonal endothelial cells when compared with age-matched controls (ten eyes of ten patients). The clinical implications of these long-term morphologic changes are unknown, but the changes may be indicative of an unstable endothelium or may be an early sign of continuing cell loss.

Aged↗

PubMed1985

Mitral valve prolapse syndrome with coronary artery spasm: a possible cause of recurrent ventricular tachyarrhythmia.

A 54-year-old man with mitral valve prolapse syndrome diagnosed by echocardiography complained of anginal pain associated with ventricular tachyarrhythmia. One day he suddenly lost consciousness, and ECG at that time revealed ventricular fibrillation. Thereafter, he developed ST elevation, sporadic premature ventricular contractions, and R on T phenomenon leading to ventricular fibrillation during the attack of anginal pain. His coronary arteriogram was normal. This case implies that coronary artery spasm may be one of the causes of chest pain and ventricular tachyarrhythmias in patients with mitral valve prolapse syndrome.

Coronary Vasospasm↗

PubMed1985

Gene expression at each stage of the life cycle of spore-forming bacteria: different sensitivity of transcription to antibiotics which act on DNA gyrase.

Effects of antibiotics acting on DNA gyrase, novobiocin and nalidixic acid on RNA synthesis during germination, vegetative growth and sporulation of Bacillus subtilis were examined. These drugs were relatively ineffective in inhibiting RNA synthesis of phase Gm 1 (5-15 min) during germination but effective in those of Gm 2 (15-40 min) and Gm 3 (40-60 min) during germination (Matsuda and Kameyama 1980). No distinguishable inhibitory effects of RNA synthesis in B. subtilis NOVr1TT mutant could be detected by novobiocin. RNA synthesis of Gm 2 and Gm 3 of this mutant was inhibited by nalidixic acid. When novobiocin was added to exponential vegetative cell or sporulating cell culture at T0 and T1 stage, the rate of RNA synthesis was inhibited by 80% for 5 min following addition of the drug. However, RNA synthesis after T2 of sporulation became resistant toward novobiocin, as was the case at an early stage of germination. RNA profiles from transcripts synthesized on administration of NOV suggested that the suppression of the synthesis of 23S and 16S rRNA is relatively greater than 4 to 5S RNA at the middle stage of germination and at vegetative growth stage in the presence of NOV. Our present data suggest that DNA gyrase is involved in the regulation of gene transcription during middle and late phases of germination, vegetative growth and T0 and T1 of sporulation. The transcription during early phase of germination and sporulation after T2 may proceed independently of this enzyme.

Nalidixic Acid↗

PubMed1985

Purification by high performance liquid chromatography of Clostridium perfringens type A enterotoxin prepared from high toxin producers selected by a toxin-antitoxin halo.

High enterotoxin-producing substrains of Clostridium perfringens type A were selected reproducibly as colonies having toxin-antitoxin haloes on agar plates of Duncan-Strong medium containing antitoxin serum. Enterotoxin from these substrains was subjected to rapid purification by high performance liquid chromatography (HPLC). For this, the toxin was extracted by sonication from sporulating bacteria grown in Duncan-Strong sporulation medium, fractionated by ammonium sulfate (40% saturation) precipitation and differential solubilization and then purified by HPLC: gel permeation chromatography through a G2000SW column and ion-exchange chromatography on a Mono Q column. Purified toxin preparations had a similar specific activity (4.2 X 10(2) mouse MLD/mg protein) and homogeneity on polyacrylamide gel-electrophoresis to preparations obtained by conventional gel permeation through a Sephadex-G200 column. By further HPLC on a Mono Q column, minor nontoxin proteins were separated from the toxin without loss of the toxicity on a protein basis. The final yield of the purified toxin was about 15% of that in the bacterial extract. The two HPLC procedures each took only one hour.

Animals↗

PubMed1985

Morphological alterations and changes in cellular cations induced by Clostridium perfringens type A enterotoxin in tissue culture cells.

The morphological alterations (bleb-balloon formation) induced by Clostridium perfringens type A enterotoxin in HeLa and Vero cells were studied under defined extracellular conditions. The action of enterotoxin was found to depend on the temperature but not on energy metabolism. The morphological alterations by the enterotoxin occurred in phosphate buffered saline containing Ca2+ and Mg2+. Of the constituents of the buffered saline, Ca2+ was essential for the morphological alterations and other ions were interchangeable. The morphological alterations by the enterotoxin occurred also in 10 mM Hepes-Na buffer, pH 7.2 containing NaCl, KCl or choline chloride at a concentration of over ca. 50 mM and in 10 mM Hepes-Ca buffer, pH 7.2 containing CaCl2 at a concentration of over ca. 50 mM. Addition of sucrose to the medium prevented induction of the morphological alterations. The amount of sucrose necessary to protect the cells increased with increase in NaCl, KCl or CaCl2 concentration in the medium. A calcium ionophore A23187 mimicked the action of enterotoxin. Examination of the cation contents of the cells by atomic absorption spectrophotometry showed early and rapid increase of Ca2+ during intoxication with concomitant changes in Na+, K+ and Mg2+ that reduced the ion concentration gradients between inside and outside of the cell present before toxin treatment. The mechanism of action of C. perfringens type A enterotoxin is discussed on the basis of these findings.

Animals↗

PubMed1985

Hemodynamic studies and response to a combined therapy of nitroglycerin ointment and dopamine in patients with acute myocarditis.

Left ventricular performance was assessed in ten patients with acute myocarditis during the acute stage (within the first 3 days after the onset of cardiac symptoms) and during the convalescent phase (3-5 weeks later). In nine, the diagnosis was confirmed by endomyocardial biopsy during the acute stage, when left ventricular function was markedly reduced, i.e., cardiac index 1.53 +/- 0.33 l/min/m2 (mean +/- SD), left ventricular stroke work index 14.1 +/- 3.9 g/beat/m2, pulmonary capillary pressure 25.9 +/- 4.3 mm Hg, and systemic vascular resistance 27.9 +/- 9.4 R units. During convalescence, seven patients improved clinically with normal cardiac function and in three it remained impaired. Cardiovascular response to nitroglycerin ointment in three patients and a combination of dopamine and nitroglycerin ointment in five were compared. Nitroglycerin ointment reduced pulmonary capillary pressure by an average of 28.5% (P less than 0.05) and systemic vascular resistance by 26.8%, while the cardiac index increased by 34.1% (P less than 0.05) and left ventricular stroke work index by 30.3% (P less than 0.01). The combined therapy was more effective, with a reduction of pulmonary capillary pressure by 30.4% (P less than 0.05) and systemic vascular resistance by 27.5% (P less than 0.05), accompanying an increase in cardiac index by 53.5% (P less than 0.005) and left ventricular stroke work index by 63.5% (P less than 0.01), with little change in the double products. This study suggests that serial hemodynamic monitoring accurately evaluates cardiac function, selection of appropriate therapy, and the hemodynamic effects of treatment in patients with acute myocarditis.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

PubMed1985

Transient appearance of collaterals during vasospastic occlusion in patients without obstructive coronary atherosclerosis.

Coronary angiography of both right and left coronary arteries, using the Sones technique, was performed during the attack of total spastic obstruction in 11 patients with clinically documented history of variant angina. None of the patients had more than 70% stenosis of organic atherosclerosis in any coronary artery and none had a history of myocardial infarction. Total spastic obstruction occurred spontaneously in 3 of 11 patients, and was provoked by ergonovine maleate in eight patients. Six patients had total spastic obstruction in the left anterior descending coronary artery, four patients had total obstruction in the right coronary artery, and one patient had total obstruction in the left anterior descending and right coronary arteries. In 7 of 11 patients, the coronary artery distal to the total spastic obstruction received collaterals from the nonspastic artery. The collaterals disappeared promptly when the spastic coronary artery was patent. These patients had ST segment elevation in the ECG during the attacks. In the remaining four patients, the spastic artery did not receive any collaterals from the nonspastic artery, associated with ST segment elevation during the attacks. These findings suggest that the brief, repetitive total occlusion of the coronary artery may stimulate the enlargement of collaterals. These collaterals may not always function to prevent the ischemia of the myocardium on the ECG.

Adult↗

PubMed1985

The development of mechanical strength of surgically anastomosed arteries sutured with Dexon.

The strength of surgically anastomosed arteries of the rat sutured with Dexon thread is studied. The abdominal aortas and the carotid arteries were severed, sutured and then the wounds were closed and the animal healed. After a specific period of time up to 13 months, the vessels were taken out and tested in uniaxial loading condition. The stress-strain relationship of the vessels was measured, and then the vessels were pulled to failure. It was found that the strength of the anastomosis was the lowest in about 4 months. In the first day, the force at failure was about the same as that of the control. Then the strength decreased with time, until a minimum was reached in 4-6 months. The tensile force to failure was about 25% of the control for the carotid artery and 49% of the control for the abdominal aorta. The corresponding values of the tensile stress at failure were 17 and 11%, respectively. The different percentages of forces and stresses were caused by the thickening of the vessel wall in the neighborhood of the suture line in the healing process. After 4-6 months, the strength gained again. At 13 months, the strength of the anastomosis was about the same as that of the control. The stretch ratio at failure was approximately constant through all periods.

Animals↗

PubMed1985

Long-dormant invasive mole associated with multiple malignancies.

A 65-year-old previously healthy housewife, gravida 3, para 3, was first diagnosed as Stage Ib carcinoma of the uterine cervix (poorly differentiated squamous cell carcinoma) and admitted. The external radiation of 5400 rad by telecobalt source was performed. No intracavitary radiation was added. After about 7 1/2 years the patient noticed a tumor of fist size on her buttocks, but she did not present in our clinic regularly. Because of enlarging tumor and general malaise she was readmitted a year later. On the fifth hospital day she died with ileus. Autopsy revealed osteosarcoma of buttocks in the radiation field, stomach cancer (tubular adenocarcinoma) with perforated peritonitis, and invasive mole of the uterine corpus. The patient's last pregnancy terminated as a full-term delivery at 26 years of age and she was 43 years at her menopause. The dormant period of invasive mole was 47 years after her last pregnancy, 30 years after her menopause, and at least 8 years after pelvic radiation.

Adenocarcinoma↗

PubMed1985

Significance of ST-segment and T wave changes in the resting electrocardiograms of patients with exertional angina, studied by exercise radionuclide angiocardiograms.

In order to investigate the clinical significance of ST-T changes in resting ECG in angina pectoris, symptom-limited ergometer exercise radionuclide angiocardiography with ECG was performed in 60 patients with exertional angina. In those with normal ECG at rest (Group N), left ventricular ejection fraction (EF) did not change during exercise (71 +/- 5% to 71 +/- 6%). In those with only ST change at rest (Group ST) and those with only T change at rest (Group T), EF decreased significantly during exercise (68 +/- 5% to 63 +/- 7%, p less than 0.01; 68 +/- 6% to 61 +/- 7%, p less than 0.001). In those with ST and T changes at rest (Group ST + T), EF was low at rest (58 +/- 11%) and decreased further at exercise (52 +/- 8%, p less than 0.001). In those whose negative or flat T wave became more negative during exercise, EF was low both at rest and at exercise. In conclusion, ST and T changes at rest in patients with exertional angina might suggest a depressed reserve of myocardial function for exercise.

Adult↗

PubMed1985

Cytotoxic activity of peripheral blood lymphocytes grown with interleukin 2 against autologous cultured tumor cells in patients with renal cell carcinoma: preliminary report.

To examine the use of interleukin 2 as a therapeutic agent for human renal cell carcinoma the peripheral blood lymphocytes derived from patients with renal cell carcinoma were grown in interleukin 2 and tested in a 4-hour 51chromium release cytotoxicity assay against autologous cultured tumor cells. Peripheral blood lymphocytes, which were cultured separately in medium alone, mitomycin C-treated tumor cells, 20 per cent interleukin 2 and tumor cells plus interleukin 2, were used as effector cells. In all patients neither peripheral blood lymphocytes in medium alone nor in mitomycin C-treated tumor cells could lyse their own tumor cells. However, in 5 of 7 patients peripheral blood lymphocytes grown in interleukin 2 regardless of the presence of mitomycin C-treated tumor cells were capable of causing 5.7, 9.4, 12.7, 36.1 and 52.5 per cent lysis at effector/target cell ratios of 25, 50, 50, 50 and 25, respectively. However, more significant cytotoxicity was not obtained by peripheral blood lymphocytes cultured with tumor cells and interleukin 2. These results suggest that interleukin 2 might become a useful agent for patients with renal cell carcinoma.

Adult↗

PubMed1985

Pump function of the human corneal endothelium. Effects of age and cornea guttata.

The specific binding of tritiated ouabain to endothelial Na/K ATPase was used to quantitate the density of pump sites in the human corneal endothelium. Donor eyes, unsuitable for use in keratoplasty, were obtained from the Wisconsin Lions Eye Bank. The endothelium of each donor eye was examined using wide-field specular microscopy, and the specular micrographs were traced and digitized for the determination of cell density. Ouabain binding was measured in matched pairs of isolated endothelial sheets. A total of 26 pairs of donor eyes, ranging in age from 11 through 91 years, were studied. Twenty pairs, determined to have normal endothelia, were found to have a constant pump site density which was independent of donor age. Six donor pairs had moderate guttata; in this group pump site density was significantly increased. These results indicate that, although pump site density is normally constant in the human corneal endothelium, conditions which increase endothelial permeability, such as guttata, can cause a compensatory increase in pump site density and presumably pump function.

Adolescent↗

PubMed1985

Long-term survival of cryopreserved corneal endothelium.

Corneas of five patients who received cryopreserved penetrating grafts 15 years previously were evaluated by regional specular microscopy and computer-assisted morphometric analysis. This technique quantitates changes in cell size and shape as well as cell number. Comparisons were made with five eyes in four patients 15 years after penetrating keratoplasty utilizing fresh grafts. In three patients, fresh and frozen tissue were transplanted in the same host. These examinations showed no difference in structure or function comparing cryopreserved tissue with fresh donor tissue.

Cornea↗

PubMed1985

Sulfonylurea stimulates liver fructose-2,6-bisphosphate formation in proportion to its hypoglycemic action.

The effects of 5 sulfonylureas on fructose-2,6-bisphosphate (F-2,6-P2) formation using isolated perfused rat liver were examined. All sulfonylureas examined stimulated dose-dependent formation of the activator in a limited range of the concentration. A maximum effect on F-2,6-P2 formation was observed at the concentration of 10(-3) M of tolbutamide or chlorpropamide, at 10(-4) M of gliclazide or acetohexamide and at 10(-6) M of glibenclamide. These concentrations of sulfonylurea correspond with those in blood when therapeutical doses of the drug are administered orally. Sulfonamide and biguanide did not show any stimulatory effect on F-2,6-P2 level. The results demonstrate that stimulation of liver F-2,6-P2 formation is a common characteristic of sulfonylureas and suggest strongly that one of the extrapancreatic actions of sulfonylurea is stimulation of F-2,6-P2 formation followed by enhancement of glycolysis and inhibition of gluconeogenesis in the liver.

Acetohexamide↗