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Biomedical subjects

Y Ueba

Publications and source records attributed to Y Ueba.

At least 37 records · Page 2Linked to original sources
PubMed1982

Dupuytren's contracture: morphological and biochemical changes in palmar aponeurosis.

The palmar aponeurosis removed from ten patients with Dupuytren's contracture was studied using morphological and biochemical approaches. The histological characteristic of Dupuytren's contracture is the presence of numerous nodules among the lamellar structures of the collagen fibres. In the nodules, there are many active fibroblasts which are surrounded by immature fibres and metachromatic substances demonstrated by toluidine blue staining. Ultrastructurally, the active fibroblasts have the characteristics of myofibroblasts, as previously reported by Dr. Gabbiani. We found that some fibroblasts have intracellular collagen fibrils in the cytoplasm. When assayed by Siegel and Martin's method, lysyl oxidase activity of the palmar aponeurosis was significantly higher in Dupuytren's contracture than in normal hands. Biochemical studies such as electrophoretic analysis of mucopolysaccharides, determination of uronic acid and collagen contents were undertaken to compare the aponeurosis of Dupuytren's contracture with normal cases. The uronic acid contents were higher in Dupuytren's contracture than in the controls. However, no difference between the two groups was found in the collagen contents and in the composition of the mucopolysaccharides. These characteristic features; existence of myofibroblasts and intracellular collagen fibrils and increase in the activity of lysyl oxidase probably play a significant role in the establishment of flexion contracture of the fingers in Dupuytren's contracture.

Adolescent↗
PubMed1981

A new microvascular surgical clip system.

A new microvascular clip system has been designed that consists of 3 sets of different sized clips, an applicator, and an approximator. The basic clip is a one-piece design consisting of two blades extending from an annular base. Its construction is simple and durable. The blade closing force is predetermined for each size clip and is set at pressures that are non-traumatic to blood vessels. The tips of the applicator allow the clip to rotate through a wide arc. Two basic clips can be used with the approximator to form a double clip.

Humans↗
PubMed1981

Plastic surgery for the cleft hand.

A new procedure is described for cleft hands with absence of the middle finger associated with a palmar cleft. Three skin flaps are made within the cleft. The index ray is transferred ulnarward--not merely shifted ulnarly, but supinated--to prevent overlapping of the fingers when they flex. Length of the finger ray can be adjusted by shortening or lengthening the second metacarpal. The common extensor tendons to the index and ring fingers are interconnected with a free tendon graft to prevent the fingers from excessive spreading. The appearance is improved without disturbing the function of the hand.

Fingers↗
PubMed1980

An experimental study on traumatic changes in microvessels produced by pressure clamping.

Acute and chronic changes produced in microvessels by clamping with serial clips were investigated by macroscopic observation and by light and scanning electron microscopy. The degree of damage of the artery was well correlated with the clamping pressure. The results of the present study revealed that a pressure of 131 g or less did not produce damage to the endothelium, while a pressure of 250 g or more brought about complete fracture or disruption of the intima and necrosis of the media.

Animals↗
PubMed1980

The effects of large doses of dexamethasone on myocardial contractility and calcium metabolism in experimental myocardial infarction.

Metabolic effects of dexamethasone (DX) on the noninfarcted functioning myocardium were studied in rabbits with experimental coronary artery ligation to evaluate the usefulness of glucocorticoids in acute myocardial infarction. Maximum active tension of noninfarcted area of the isolated perfused hearts was markedly reduced 6 hr, 2 days, and 5 days after ligation, associated with significant decreases in norepinephrine (NE) and cAMP contents, but with no changes in adenylate cyclase (AC) and cAMP phosphodiesterase (PDE) activities. Calcium content of mitochondrial fraction was considerably increased in the peri- and noninfarcted area without any changes in microsomal CA2+ or myocardial total Ca2+. Ca2+ uptake rate and Ca2+-dependent ATPase activity of the sarcoplasmic reticulum fraction from the operated hearts were markedly reduced. Intramuscular administration of DX (3 mg/kg body wt/day) for 2 days after operation significantly improved these reductions in myocardial function and metabolism. In normal hearts from animals without infarction, DX caused 48% elevation in basal cAMP level, marked reductions in mitochondria and microsomal Ca2+, and 26% decrease in PDE activity, although no changes in myocardial total Ca2+ AC activity and myocardial contractility were observed. NE-induced inotropic effects were markedly enhanced in both control and operated groups with DX treatment. These results indicated that large doses of DX would improve the reduced myocardial function and metabolism in acute myocardial infarction by increasing basal cAMP level and by its influence on intracellular Ca2+ available for cellular activity.

Animals↗
PubMed1978

Changes in collagen cross-linking and lysyl oxidase by estrogen.

Dermal collagen solubility and lysyl oxidase activity of bones were measured in DDD mice of advancing age. Insoluble fractions of the dermal collagen increased more rapidly in females than in males after 5 weeks of age. Activity of the lysyl oxidase extracted from bones was higher in females than in males after 4 weeks of age. After sexual maturation, such sex differences were always observed in skin as well as in bone tissue. In other experimental animals, dermal collagen solubility was markedly decreased by estrogen treatment and lysyl oxidase was remarkably activated by estrogen in both skin and bone. Thus it is clear that estrogen stimulates the enzyme activity and accelerates the maturation of collagen and elastin in extracellular space.

Aging↗
PubMed1973

[Heart failure].

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Animals↗