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Biomedical subjects

M Ueda

Publications and source records attributed to M Ueda.

At least 1,477 records · Page 82Linked to original sources
PubMed1978

An unusual case of portasystemic encephalopathy caused by splenic vein occlusion following gastrectomy.

A patient with recurrent episodes of consciousness disturbance following partial gastrectomy is presented. Angiographic examination revealed a great portasystemic shunt, which probably developed following the postoperative splenic vein thrombosis. This is suspected a rare cause of the condition. In chronic liver disease, recurrent encephalopathy which is caused by portasystemic shunt is well known as one of the most frequent complications. It is very uncommon in adults, however, when the liver is not concerned in the shunt formation. In the present paper the authors report an unusual case of recurrent consciousness confusion which is due to the great portasystemic shunt probably caused by postgastrectomy splenic vein thrombosis.

Cognition Disorders↗
PubMed1978

D-Glucose anomeric preference of hexokinases in higher animals.

The D-glucose anomeric preference of hexokinases isolated from rat liver, brain, and skeletal muscle, and bovine retina was studied using the glucose-6-phosphate dehydrogenase-NADP system. The ratios of maximum phosphorylation rates of beta-D-glucose to those of alpha-D-glucose were 1.33, 1.46, and 1.54 for hexokinase types I, II, and III from rat liver, 1.45 and 1.63 for type I from rat brain and bovine retina, 1.53 for type II from rat skeletal muscle, and 0.55 (when determined at 5 mM) for type IV (glucokinase) from rat liver, respectively.

Animals↗
PubMed1978

Cell-mediated and humoral immunity to chick type II collagen and its cyanogen bromide peptides in guinea-pigs.

Cell-mediated immunity (CMI) to chick type II collagen and its cyanogen bromide (CB) peptides was studied in guinea-pigs using cutaneous delayed hypersensitivity reactions. Responses were largely independent of molecular conformation in animals immunized with either native or denatured collagen, and reactions obtained with CB peptides 8, 9, 10 and 12 suggested that sites in the central regions of collagen chains were recognized in CMI. Antibodies to collagen were detected by haemagglutination and immunofluorescence only in animals immunized with native molecule and not in animals immunized with denatured or CB-digested material. Humoral and CMI responses were similar in that neither recognized the pepsin-labile non-helical regions of the molecule. The responses differed in that humoral reactions were conformation-dependent and type-specific and CMI reactions were not.

Animals↗
PubMed1977

Spreading depression elicited by thermal effects of ultrasonic irradiation of cerebral cortex in rats.

Cortical spreading depression (CSD) was elicited by focused ultrasonic irradiation (800 kHz) of exposed cerebral cortex in anesthetized rats. With the acoustic output of 0.64 W at the probe-tissue contact (3 mm in diameter), CSD was elicited after 28-sec irradiation in normothermic rats. Reduction of cortical temperature to 31 degrees C increased the threshold irradiation time to 82 sec on the average. Ten- to thirty-sec heating of cerebral cortex with a thermode elicited CSD when surface temperature exceeded 47 degrees C. Histological examination of the cortical areas exposed to threshold irradiation revealed a central coagulation lesion surrounded by edema. It is concluded that the ultrasonic irradiation elicits CSD by dissipated heat. Differences in threshold duration of irradiation in hypothermic and normothermic rats were used to compute the threshold temperature which had to be exceeded in the critical volume of cortex in order to start CSD.

Animals↗
PubMed1977

Differential effects of cortical speading depression on epileptic foci induced by various convulsants.

Interaction between epileptic foci and spreading depression (SD) was studied in the cerebral cortex of rats anesthetized with Nembutal. At comparable discharge rates, picrotoxin and penicillin caused complete and partial SD blockade respectively, strychnine and Metrazol were ineffective and Aldactone facilitated SD. Conversely, the duration of SD-induced blockade of epileptic activity was maximal for Aldactone and minimal for picrotoxin. Treatment of the picrotoxin focus with tetrodotoxin (10(-4)M) reduced the discharge rate and reinstated SD propagation into the focus. [K+]e measured with ion-selective K+ electrodes 1 mm below the cortical surface increased to 8 mM in penicillin foci blocking SD and remained below 5 mM in Aldactone foci. It is concluded that the differential effect of various convulsants on SD propagation depends on the potassium concentration in the depth of the focus rather than on the discharge rate or on the mechanism of the the epileptogenic effect.

Animals↗
PubMed1977

[Comparative study between dobutamine and other catecholamines in their effects on the cardiac contraction and rhythm (author's transl)].

Dobutamine (DOB) showed a dose dependent positive introphic effect on the right ventricular muscle of vagotomized Beagle dogs under pentobarbital anesthesia. Positve inotropic effects of other catecholamines (CA) decreased in the following order; isoproterenol (Iso, 115) greater than norepinephrine (NE, 15) greater than DOB (1) greater than dopamine (DA, 0.36). Brachiocephalic arterial flow was also increased by DOB with a positive inotropic effect in the right ventricular muscle. Though the positive inotropic effect of DOB was slightly decreased by pretreatment with phenoxybenzamine, such was almost completely antagonized by propranolol. Contractions of isolated cat papillary muscle driven by electrical stimulation (12 beats/min) were increased by CA in the following order; Iso (17) greater than NE (3) greater than epinephrine (2.5) greater than DOB (1) greater than DA (1 greater than). Activity of DOB to induce spontaneous contractions of papillary muscle was weakest among these CA. To determine the arrhythmogenic effect of these CA, coronary ligated Beagle dogs were employed, in which the anterior descending branch of the left coronary artery was ligated. Arrhythmogenic activity of DOB was weaker than other CA employed both in early stages and 48 hr after coronary ligation. DOB shows good potential for treating acute cardiac insufficiency and cardiogenic shock, as effects on heart rate and blood pressure are weaker.

Adrenergic alpha-Antagonists↗
PubMed1977

[Effects of dobutamine on the respiration, blood pressure, and several blood components in dogs (author's transl)].

In anesthetized Beagle dogs, intravenous bolus administration of dobutamine (DOB) caused an increase of systolic pressure and a decrease of diastolic pressure--increase of pulse pressure. These effects of DOB were not so pronounced as the marked depressor effect of isoproterenol (Iso) and pressor effects of epinephrine (Epi), norepinephrine(NE) and dopamine (DA). The degree of the positive chronotropic effect of DOB was the same as that of DA. Incidences of ventricular extrasystole observed at the maximal dosages of catecholamines, intravenous administration of 300 microgram/kg of DOB, 3 of Iso, 10 of Epi, 10 of NE, and 300 of DA, were 1/4, 1/4, 4/4, 4/4, and 2/4, respectively. With no evidence of ventricular extrasystoles, an increase of pulse pressure was also observed in conscious dogs given an intravenous infusion of DOB (10 or 30 microgram/kg/min for 20 min). Iso infusion resulted in an increase of serum free fatty acid, and a decrease of serum Na and K. Although DA infusion increased blood glucose and serum free fatty acid, DOB infusion produced no significant concentration change of blood components. These experimental results indicate that effects of DOB on the blood pressure, heart rate, and several blood components are weaker than other catecholamines.

Anesthesia↗
PubMed1977

Pituitary-gonadal function in male patients with myotonic dystrophy- serum luteinizing hormone, follicle stimulating hormone and testosterone levels and histological dmaage of the testis.

Variations in serum levels of LH and FSH after administration of synthetic LH-RH, and basal levels of serum testosterone were studied in 9 male patients with myotonic dystrophy. The degree of testicular damage, as determined histologically on biopsy specimens, was also studied. Results were as follows: 1) it was observed that both the basal and stimulated (maximal) levels of serum LH and FSH were significantly higher than levels found in 9 sex- and age-matched normal controls. 2) The basal level of serum testosterone was consistently lower in the patient group. One patient, however, showed a low normal level, which represented a statistically significant reciprocal relation to both LH and FSH levels as expressed on a logarithmic scale. 3) There was a significant trend which indicated that the higher the serum LH, FSH levels, or the lower the basal levels of serum testosterone, the more extensive was the damage to the seminiferous tubules. From these findings it was concluded that hypogonadism in patients with myotonic dystrophy, is characterized by the development of lesions in the seminiferous tubules.

Adolescent↗