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Biomedical subjects

H Shida

Publications and source records attributed to H Shida.

At least 109 records · Page 6Linked to original sources
PubMed1982

Ultrastructural and biochemical identification of Con A receptors in the desmosome.

Correlated ultrastructural and biochemical methods were used to identify and localize Concanavalin A (Con A) receptors in the desmosomes of bovine epidermis. Specific carbohydrate residues were labeled with ferritin-Con A in thin sections of tissue embedded in a hydrophilic resin. Quantitative mapping of ferritin distribution in labeled desmosomes revealed that Con A receptors are localized in the intercellular zone and concentrated along the desmosomal midline or central dense stratum. Labeling was almost entirely absent when sections were treated with ferritin-Con A in the presence of 0.1 M alpha-methyl mannoside, a hapten-inhibitor of Con A. "Whole" desmosomes and desmosomal intercellular regions (desmosomal "cores") were purified from bovine muzzle epidermis. Sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis reveals a limited number of major desmosomal protein constituents. Certain of these are glycoproteins and are greatly enriched in the core fraction. Almost all the desmosomal glycoproteins are intensely labeled when electrophoretic gels of whole desmosome or core fractions are exposed to fluorescent Concanavalin A.

Animals↗
PubMed1982

Electron microscopic localization of specific carbohydrate groups in thin sections of tissues embedded in a hydrophilic resin: concanavalin A receptors in mouse spleen.

An improved postembedding method for electron microscopic localization of concanavalin A (Con A) receptors in ultrathin sections is reported. Materials are embedded in a hydrophilic resin, glycol methacrylate copolymerized with glutaraldehyde and urea, using a precisely controlled polymerization schedule that preserves ultrastructural integrity. Ferritin-Con A binds specifically in ultrathin sections of mouse spleen tissue and of Sephadex beads embedded in this resin. Quantitative investigations of procedures for decreasing nonspecific labeling demonstrate that preincubation of sections with bovine serum albumin reduces background to a very low level. This high-resolution method allows macromolecular affinity probes access to receptors in all cellular locations, while maintaining good morphological preservation.

Animals↗
PubMed1981

Somatic and psychomotor development of children after hypothermic open-heart surgery.

One hundred and seven patients with ventricular septal defect who survived one and a half to thirteen years after hypothermic open-heart surgery were reviewed with respect to somatic, intellectual, and psychomotor development. There were no negative effects associated with deep hypothermic arrest in any of these areas. Abnormal electroencephalograms were seen in one-half the number of patients examined, but there was no close relation between the circulatory arrest period and electroencephalographic findings. CT scanning of the brain indicated that the abnormality decreased with the lapse of the time after hypothermic open-heart surgery. It would appear that hypothermic open-heart surgery with limited circulatory arrest is a useful method, providing that the circulatory arrest is not allowed to exceed a limited period. However electroencephalographic assessment suggests that postoperative cerebral abnormalities may occur more frequently than previously suspected, despite the lack of preoperative abnormalities on the electroencephalograms.

Body Height↗
PubMed1981

Inhibitory mechanisms of insulin secretion associated with hypothermic open-heart surgery.

In order to clarify the inhibitory mechanism of insulin secretion associated with open-heart surgery, the influence of insulin antagonistic hormones on insulin secretion was studied in 20 patients with congenital heart diseases undergoing open-heart surgery, under simple deep hypothermia. Despite a hyperglycemia, plasma immunoreactive insulin and C-peptide showed no change during the cooling period, while with the exception of plasma human growth hormone, dopamine-beta-hydroxylase, immunoreactive glucagon, cortisol and cyclic AMP in plasma, either showed no change, or a decrease during the cooling period. It is assumed that catecholamine, glucocorticoid and glucagon do not play an important role in the inhibitory mechanism of insulin secretion during hypothermic open-heart surgery, and a transient hypofunction of the pancreas as well as the liver and the adrenal gland is probably involved.

Blood Glucose↗
PubMed1981

Changes of kallikrein and serotonin in plasma during and after open-heart surgery.

Plasma kallikrein activity and plasma serotonin were studied during and after open-heart surgery in 15 patients with extracorporeal circulation and in 15 patients with surface-induced deep hypothermia. Following results were obtained: 1) Plasma kallikrein activity which reflects the activation of the kinin system, showed no significant change during extracorporeal circulation, and significantly increased three hours after the termination of perfusion. However, there was no significant difference in plasma kallikrein activity between the patients with and without low cardiac output syndrome (LOS). In surface-induced deep hypothermia, plasma kallikrein activity showed no significant change during and after operation. 2) Plasma serotonin significantly decreased during both extracorporeal circulation and hypothermia. Moreover, there was no significant difference in plasma serotonin between the patients with and without postoperative LOS or pulmonary hypertension. It is assumed that plasma serotonin may not play an important role in regulating blood pressure during or after open-heart surgery with either extracorporeal circulation or surface-induced deep hypothermia.

Adolescent↗
PubMed1981

Effect of dilazep on myocardial contractility following acute ischemia and reperfusion in isolated blood-perfused canine left ventricular muscle.

Myocardial protection by dilazep HCl, an antianginal drug and a potent calcium antagonist, against myocardial damage following acute ischemia and reperfusion was studied with respect to myocardial contractility in isolated blood-perfused canine left ventricular muscle. Myocardial function was expressed by percent recovery rate of maximal net developed tension. 1) The coronary infusion of dilazep revealed significant myocardial protection during normothermic ischemic arrest of 45 min and reperfusion. 2) The intravenous administration of dilazep to the support dog and Young's infusion also showed significant myocardial protection during normothermic ischemic arrest of 45 min and reperfusion. Dilazep showed no persistent depression of myocardial contractility due to its calcium antagonistic effect during reperfusion. 3) The combination of intravenous administration of dilazep to the support dog, Young's infusion, and hypothermia showed significant myocardial protection during prolonged ischemia and reperfusion even in hypertrophied ventricle. These results demonstrate that dilazep provides effective myocardial protection during ischemic arrest and reperfusion by preventing abnormal calcium accumulation in myocardial cells during reperfusion. No persistent depression of myocardial contractility during reperfusion may support dilazep's clinical application as a myocardial protective agent in open-heart surgery.

Animals↗
PubMed1981

[Myocardial protection by dilazep in myocardial ischemia and reperfusion].

Myocardial protection of dilazep HCl, which is an antianginal drug and a potent calcium antagonist against myocardial damage following acute ischemia and reperfusion, was studied on myocardial contractility in isolated blood perfused canine left ventricular muscle. Myocardial function was expressed by percent recovery rate of maximum net developed tension. 1. The coronary infusion of dilazep revealed significant myocardial protection during normothermic ischemic arrest of 45 min and reperfusion. 2. The i.v. administration of dilazep to the donor dog and Young's infusion also showed significant myocardial protection during normothermic ischemic arrest of 45 min and reperfusion. 3. The combination of i.v. administration of dilazep to the donor dog, Young's infusion, and hypothermia showed significant myocardial protection during prolonged ischemia and reperfusion even in hypertrophied ventricle. 4. Dilazep prevents abnormal calcium accumulation in myocardial cells during reperfusion. These results demonstrate that dilazep provides effective myocardial protection during ischemic arrest and reperfusion, and they may support its clinical application as a myocardial protective agent for open-heart surgery.

Animals↗
PubMed1980

Effect of hypothermia during ischemia on myocardial contractility in nonhypertrophied and hypertrophied ventricles.

The effect of hypothermic ischemic arrest on myocardial contractility was investigated with use of isolated blood-perfused canine heart preparation in the hypertrophied left ventricle created by supravascular aortic stenosis and the non-hypertrophied ventricle. The following results were obtained: The percent recovery rate of net developed tension during reperfusion after an ischemic period of 150 minutes at the myocardial temperature of 17 degrees C was 90 +/- 9% in the non-hypertrophied muscle, that is, hypertrophied left ventricle was considered to be more vulnerable to ischemia as compared to nonhypertrophied left ventricle, suggesting the necessity of more intense myocardial protection in addition to cardiac hypothermia against ischemia in the hypertrophied heart.

Animals↗