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Biomedical subjects

M Matsuda

Publications and source records attributed to M Matsuda.

At least 1,171 records · Page 65Linked to original sources

Regional specular microscopy of endothelial cell loss after intracapsular cataract extraction: a preliminary report.

In a group of 10 patients (12 eyes) undergoing intracapsular cataract extraction, corneal endothelial cell loss was serially investigated by means of regional specular microscopy. Prevoperatively there were no significant regional differences in the endothelial cell density. Two weeks after surgery, the superior endothelium alone showed a significant cell loss (15.6%). Whereas, a definite endothelial cell loss occurred in each region of the cornea one month after surgery. The cell loss was greater in the superior (22.8%) and lower in the inferior (4.7%), respectively, when compared to that seen in the central cornea (9.6%). In each region, cell loss continued 3 months postsoperatively, but no significant cell loss occurred thereafter. These results suggest that the entire endothelial cell population may participate in the healing of the damage associated with intracapsular cataract extraction and that regional specular microscopy can be of help for detailed evaluation of such a damage.

Aged↗

Inhibitory effect of cephalosporins on gamma-aminobutyric acid receptor binding in rat synaptic membranes.

Cephalosporins inhibited gamma-aminobutyric acid receptor binding in a concentration-dependent manner in vitro. Scatchard analysis revealed that cefazolin decreased the binding capacity but did not change the affinity of the receptor. It is suggested that this inhibition of gamma-aminobutyric acid receptor binding may be involved in the induction of convulsions by cephalosporins.

Animals↗

Rapid, simplified method for production and purification of tetanus toxin.

A rapid, simplified method for production and purification of tetanus toxin from bacterial extracts was described. The extracts were prepared by stirring young cells (ca. 45-h culture) of Clostridium tetani in 1 M NaCl-0.1 M sodium citrate, pH 7.5, overnight at 0 to 4 degrees C. The toxin was purified by a combination of (i) ammonium sulfate fractionation (0 to 40% saturation), (ii) ultracentrifugation for removal of particulate materials, and (iii) gel filtration by high-pressure liquid chromatography on a TSK G3000 SW-type column. This method required 6 days as follows: (i) overnight incubation of the seed culture, (ii) 2 days for growing the bacteria for toxin production, (iii) overnight extraction of the toxin from the bacteria, (iv) overnight precipitation of the toxin with ammonium sulfate, (v) 2 h for ultracentrifugation of the ammonium sulfate concentrate of the bacterial extract, and (vi) 1 h for high-pressure liquid chromatography. The minimum lethal dose of the purified toxin preparations for mice was 1.4 X 10(7) to 1.5 X 10(7) per mg of protein and they showed 360 to 390 Lf (flocculating activity) per mg protein and a 280/260 nm absorbance ratio of 2.0 to 2.1. The final recovery of the toxin from bacterial extracts was 90 to 93%. The purified preparations gave a single band of toxin protein with a molecular weight of 150,000 +/- 5,000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. On crossed immunoelectrophoresis, the purified toxin preparations gave a single precipitation arc against anti-crude toxin serum.

Ammonium Sulfate↗

Light and agonist alter vasoactive intestinal peptide binding and intracellular accumulation of adenosine 3',5'-monophosphate in the rat pineal gland.

We examined the effects of environmental light and prior treatment with an agonist on vasoactive intestinal polypeptide (VIP) binding and VIP stimulation of cAMP accumulation in the rat pineal gland. VIP binding to pinealocytes and cAMP accumulation in response to VIP were significantly increased in animals kept exposed to constant light compared to those in animals experiencing a dark night before the experiments. Scatchard analysis of [125I]VIP binding indicated the presence of two classes of binding sites: high affinity, low capacity sites and low affinity, high capacity sites. The increased VIP binding to pinealocytes in rats maintained in constant light was attributed to an increase in the number of available VIP receptors at both high and low affinity sites. The affinity of VIP binding to cells was not affected by exposure of the animals to light. VIP stimulation of cAMP accumulation was not inhibited by d,l-propranolol. Prior treatment of pinealocytes with VIP decreased [125I]VIP binding by reducing the number of receptors and significantly inhibited subsequent VIP stimulation of cAMP accumulation. Prior treatment with norepinephrine did not alter the number of VIP receptors. Our results strongly suggest that VIP is a neuromodulator of pineal function.

Animals↗

Rupture of previously unruptured giant carotid aneurysm after superficial temporal-middle cerebral artery bypass and internal carotid occlusion.

A 51-year-old woman with an unruptured giant aneurysm of the internal carotid artery was treated by gradual occlusion of the internal carotid artery in the neck combined with a superficial temporal artery to middle cerebral artery bypass graft. Visual field defects improved after the operation, and thrombosis of the aneurysm was confirmed by angiography and computed tomography. Nevertheless, a fatal hemorrhage occurred 34 days after the final turn of the Selverstone clamp. The possible mechanism of rupture of the apparently thrombosed aneurysm is discussed. There is a risk of rupture of the aneurysm as long as the aneurysmal lumen remains after proximal ligation, no matter how small it may be.

Carotid Artery Diseases↗

Usefulness of intraoperative coronary angioplasty in aorto-coronary bypass surgery.

Seven patients underwent aorto-coronary bypass grafting combined with intraoperative transluminal coronary angioplasty (OTCA), because of multiple obliteration of the coronary arteries with poor distal run-off. The patients were all males with a mean age of 52.6 years. For OTCA, a SIMPSON-ROBERT vascular dilator system was used. Eight stenoses in seven patients, four in the left anterior descending artery (LAD) and three in the right coronary artery (RCA) were dilated by means of OTCA. In five patients the results were satisfactory but in two patients the procedures resulted in failure. Dilatation failed because of severe calcification of LAD in one case and, in the other, distal RCA was completely obstructed by a compressed atherosclerotic plaque at the bifurcation after the procedure. From these limited experiences we believe that OTCA might be a method of selection to treat the patients with coronary sclerosis with poor distal run-off.

Angioplasty, Balloon↗

Clinical experience of percutaneous transluminal coronary angioplasty--technique and results.

PTCA (percutaneous transluminal coronary angioplasty) was performed on 109 patients from April 1981 through March 1984, and successful dilatation was achieved in 82 patients (75.2%). The patients were followed for an average period of 15.6 +/- 10.6 months (range, 0.5-36 months). Twenty-one patients (24%) relapsed, and repeat PTCA resulted in successful dilatation in 13 of 24 patients. The present communication discusses important technical points of PTCA, results of follow-up, and findings in cases of recurrence. The prognosis was good in patients with an uneventful course during six months or more of follow-up. When the successful patients were divided into two groups of relapse and non-relapse, there was no statistically significant difference between the two groups regarding sex, age, history of angina pectoris, number of vessels involved, and which coronary artery was involved. It remains for further studies to find the cause of recurrent stenosis and establish an appropriate therapy to prevent it.

Adult↗

Changes in the normal corneal endothelial cellular pattern as a function of age.

Human endothelial morphologic changes were quantitated by specular microscopy and computer-assisted morphometry to establish normal baselines of various morphologic parameters. Cellular polymegethism and cellular pleomorphism increases with age, and normal baseline parameters are detailed. Furthermore, no significant difference in any morphologic parameters between the right and left eye and between central and peripheral endothelium was detected in the normal corneas examined. These normal morphologic baselines can possibly be utilized to detect early corneal endothelial pathology and/or cell loss nondetectable by cell density measurement.

Adolescent↗

Corneal endothelial changes in diabetic dogs.

The corneal endothelium of alloxan diabetic dogs was examined by wide-field specular microscopy and compared to that of age-matched non-diabetic dogs. Computer-assisted morphometry of individual cells showed that the diabetic dog endothelium had marked polymegethism and pleomorphism similar to that previously described in diabetic patients. There also appeared to be a positive correlation between the degree of these endothelial changes and the diabetic control as demonstrated by HbA1 concentration.

Alloxan↗

[Transformation of ovarian yolk sac tumor to immature teratoma following chemotherapy].

The patient, a 28-year-old woman, in her ninth week of pregnancy, was operated on for stage Ia, mixed germ cell tumor (grade 3 immature teratoma + yolk sac tumor) of AFP decreased to the normal level. Eight months later, an intrapelvic mass and raised AFP were found. The extirpated recurrent tumor in the pouch of Douglas was a grade 2 immature teratoma with no yolk sac element. FAM chemotherapy was given again, and the patient is alive and well after taking oral UFT. As in testicular germ cell tumors, ovarian germ cell tumors can be converted to a more differentiated tumor following chemotherapy.

Adult↗

Correlation of corneal endothelial pump site density, barrier function, and morphology in wound repair.

After transcorneal freezing, physiologic function (pump and barrier) of the regenerating rabbit corneal endothelium was evaluated and compared with the morphologic differentiation that occurs during wound healing. Endothelial pump function was investigated utilizing the specific binding of tritiated ouabain to endothelial Na+/K+ ATPase (pump sites); the permeabilities of isolated de-epithelialized corneas to labeled inulin and dextran were measured to determine endothelial barrier function. Endothelial recovery after transcorneal freezing can be described as a three-stage process. Stage one is characterized by the establishment of an initial coverage of the wound by pleomorphic spindle-shaped cells which form a functional but incomplete barrier and minimal pump site density. In stage two, the cells assume a flattened configuration consisting of irregular polygons and establish nearly normal pump capacity. In stage three, a significant remodeling of the monolayer continues despite the layer's early physiologic recovery.

Animals↗

[Clinical phase II study of 5'-DFUR for cancer of the digestive organs by a cooperative study group].

Phase II study of a new 5-fluorouracil derivative, 5'-deoxy-5-fluorouridine (5'-DFUR), was performed with oral administration. Forty-nine patients with advanced cancer of the digestive organs, lung and breast were entered, and 8 institutions in Hokkaido were involved. 5'-DFUR was administered three or four times a day at a daily dosage of 600 to 1200 mg. Partial response was observed in three gastric cancer cases and two breast cancer cases out of 39 evaluable cases, and minor response was observed in one colorectal cancer case. Overall response rate was 12.8%, 15.8% in gastric cancer and 66.7% in breast cancer. Side effects were observed in 15 cases out of 45 (33.3%), which mainly consisted of gastro-intestinal disturbances such as diarrhea.

Adenocarcinoma↗