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Biomedical subjects

Y Hara

Publications and source records attributed to Y Hara.

At least 649 records · Page 36Linked to original sources
PubMed1986

Electrophysiology of smooth muscle of the small intestine of some mammals.

Intracellular recordings were made from cells located in the longitudinal, inner and outer circular muscle layers of the dog, cat, rabbit, opossum and human small intestine. In whole-thickness preparations in all five species, longitudinal muscle cells generated slow waves and spikes. However, in isolated longitudinal muscle preparations, all cells tested were electrically silent. In whole-thickness and in isolated preparations, cells in the inner circular muscle layer generated spontaneous spikes superimposed on slow potentials. However, the occurrence of spikes and slow potentials was more regular in whole-thickness preparations. In whole-thickness preparations, cells in the outer circular muscle layer generated slow waves which were coupled with phasic contractions. However, in isolated outer circular muscle preparations, all cells tested were electrically silent and spontaneous phasic contractions were absent. In whole-thickness preparations, non-neural cells located on the serosal side of the outer circular muscle layer generated slow waves. The data suggest that spontaneous slow waves of the small intestine of the dog, cat, rabbit, opossum and human are generated in non-neural cells located between the longitudinal and outer circular muscle layer and by non-neural cells located between the outer and inner circular muscle layers.

Acetylcholine↗
PubMed1986

Effect of potassium and acetylcholine on canine intestinal smooth muscle.

Mechanical and intracellular electrical activity were recorded simultaneously from small intestinal smooth muscle of the dog. Tonic and phasic contractions due to exogenous acetylcholine and elevated external K+ concentration were spike-dependent in longitudinal and inner circular muscle layers and spike-independent in the outer circular muscle layer. Voltage-tension curves were generated by graded depolarization of the membrane. In spike-dependent longitudinal and inner circular muscle layers the threshold voltage for initiation of spikes and contraction was approximately --53 mV. In spike-independent outer circular muscle layer the voltage threshold for contraction was approximately -42 mV. The resting membrane potential in longitudinal and inner circular muscle layers was close to the voltage threshold for initiation of spikes and contraction. In contrast, in the outer circular muscle it was approximately 20 mV more negative to the voltage threshold for contraction. In the outer circular muscle layer of whole-thickness preparations an increase in the amplitude of phasic contractions caused by acetylcholine was associated with an increase in the amplitude of the slow waves. Tone was related to the resting membrane potential. In preparations of isolated outer circular muscle acetylcholine caused depolarization of the membrane potential, slow waves and phasic contractions; comparable depolarization by increases in external K+ concentration did not induce slow waves or phasic contractions. Comparison of the effect of acetylcholine on outer circular muscle with the voltage-tension curve for this muscle layer showed that the top of the slow wave was associated with just the contractile force predicted by the voltage-tension curve. This suggests that acetylcholine altered the force of phasic contraction of the outer circular muscle through a voltage-dependent mechanism. In non-neural cells located on the serosal side of the outer circular muscle layer of the dog, cat and rabbit, changes in external K+ concentration depolarized the membrane and abolished slow waves. There was no response to acetylcholine.

Acetylcholine↗
PubMed1986

[Cardiovascular effects of MY-5116 and MY-1250].

The effects of MY-5116, isoamyl 5,6-dihydro-7,8-dimethyl-4,5-dioxo-4H-pyrano [3,2-c]quinoline-2-carboxylate, an anti-allergic drug, and MY-1250, an active metabolite of MY-5116, on the cardiovascular system were studied in dogs, rats and guinea pigs. Orally administered MY-5116 (300 mg/kg) had no effect on the cardiovascular system in anesthetized dogs and conscious rats. In anesthetized dogs, MY-1250 and disodium cromoglycate (DSCG) caused hypotension, bradycardia and reduction of respiration rate from the doses of 3 and 10 micrograms/kg, i.v., respectively. Both drugs showed a tachyphylaxic phenomena which was crossed with each other. MY-1250-induced cardiovascular effects were abolished by bilateral vagotomy. MY-1250 (3-30 micrograms/kg, i.v.) caused a decrease of carotid blood flow, a transient decrease followed by a slight increase of renal blood flow, and a transient increase followed by a slight decrease of femoral blood flow in anesthetized dogs. MY-1250 had no effect on sympathetic ganglion, but increased the contractile force of isolated left atria from guinea pigs at 10(-5) g/ml and increased its rate at 10(-4) g/ml. These positive inotropic and chronotropic effects were not influenced by reserpinization. MY-1250 had no effect on the norepinephrine-induced dose-response curve in isolated rat aorta.

Animals↗
PubMed1986

Spontaneous autoimmune thyroiditis in Bio Breeding/Worcester (BB/W) rat.

We investigated the serial changes in the plasma levels of anti-thyroglobulin antibody (ATA) by solid-phase enzyme immunoassay, thyroid hormones and blood glucose, since spontaneous occurring lymphocytic thyroiditis (LT) has been found in spontaneously diabetic Bio Breeding/Worcester (BB/W) rat. We also observed the correlation between these levels and histological findings in the thyroid gland. The incidence of diabetes was 0% in 5 week old rats (group A), 70% in 11 week old rats (group B), and 86% in 20 week old rats (group C), while LT was observed in 0% in group A, 20% in group B and 48% in group C. Although the incidence of both increased with age, there was no link between LT and diabetes. Plasma ATA levels were 91.4 +/- 28.5 (OD492 X 1,000, mean +/- SEM) in the control (14 week old Wistar Furth) rats. 49.5 +/- 15.4 in group A, 197.8 +/- 41.5 in group B, and 376.7 +/- 48.7 in group C, again showing a clear increase with age. In group C, the plasma levels of ATA in rats with LT were significantly higher than those without LT. In addition, 6 out of 11 rats without LT had abnormaly high ATA levels. In group C, the plasma levels of free 3,5,3'-triiodothyronine (FT3) and total thyroxine (TT4), and also the FT3/TT4 ratio were significantly lower and the plasma levels of blood glucose were higher than in the other groups. There was no difference between the plasma thyroid hormone levels in rats with LT and those without LT. These studies suggest that LT may occur independently of insulitis, namely diabetes, ATA levels and the incidence of LT increase with age, the site of ATA production may not be confined to the thyroid gland, and the derangement of glucose metabolism may be one of the factors in the decrease in plasma thyroid hormone. The BB/W rat is not only a useful animal model to use in exploring the pathogenesis of human insulin-dependent diabetes mellitus, but also spontaneous autoimmune thyroiditis.

Age Factors↗
PubMed1986

Interference with thyrotropin receptor antibody determination by a spuriously occurring anti-bovine TSH antibody.

Abnormally negative values of thyrotropin binding inhibitor immunoglobulin (TBII) were found in the sera from a patient with Graves' disease. This was due to the presence of potent bovine TSH (bTSH) binding activity in the sera. This activity was demonstrated to be in immunoglobulin G (IgG) with a lambda light chain isotype, which was shown to have an affinity for bTSH with a Ka value of 3.5 X 10(10) M-1 and a maximum binding capacity of 1.1 X 10(-14) M/mg IgG. F(ab')2 fragments obtained through pepsin digestion from the patient's IgG retained bTSH binding activity. [125I] bTSH binding to this IgG was inhibited by the TSH receptor. The inhibition was not completely competitive, suggesting the presence of different binding sites for this IgG and the TSH receptor on the TSH molecule. This IgG, however, could not bind labelled human TSH (hTSH). Since neither TSH nor other pituitary derivatives had ever been given to the patient, this bTSH binding activity was considered to be due to a spuriously occurring anti-bTSH antibody.

Adult↗
PubMed1986

Decreased serum thyroglobulin levels in the late stage of pregnancy.

Serum thyroglobulin levels were serially measured in 25 normal pregnant women to evaluate thyroidal activity during normal pregnancy. Measurements included serum T3, T4, free T4, TBG, and TSH. Tg and FT4 levels were found to be decreased in the third trimester when compared with those of the first trimester and with those of normal non-pregnant individuals (P less than 0.01). TSH levels were higher than normal in pregnant women at all stages of pregnancy, with a significant rise at the third trimester. These findings suggest the presence of a subclinical hypothyroid state in the late stage of normal pregnancy.

Female↗
PubMed1986

Immunohistological study with peroxidase-antiperoxidase staining in a case of generalized prepubertal periodontitis.

A case of prepubertal periodontitis was observed and examined immunohistologically with peroxidase-antiperoxidase staining. The patient was an 11-year and 7-month-old Japanese girl, well-developed and well-nourished. Her parents were first cousins. Her chief complaint was the loosening and loss of the permanent teeth. There was a similar history of primary dentition. Her remaining permanent teeth were loosened with severe alveolar bone loss, but calculus deposit was minimal. Significantly, there was no palmar-plantar hyperkeratosis. General examination showed normal data except for the increase of the immunoglobulin concentrations. In neutrophil function tests chemotaxis was depressed, although phagocytosis, random migration and superoxide production were within normal limits. Histologically, neutrophils were seen in the gingival tissue and other findings were also similar to those of adult periodontitis. In immunohistological examination, IgG-bearing cells which mostly consisted of plasma cells predominated in the lesion. Considering the past history, the immunodeficiency and the absence of palmar-plantar hyperkeratosis, the case was diagnosed as prepubertal periodontitis.

Aggressive Periodontitis↗
PubMed1986

Effect of green tea catechins on plasma cholesterol level in cholesterol-fed rats.

Effects of tea catechins (tannins) on lipid metabolism were studied in male weanling rats fed a 25% casein diet containing 15% lard and 1% cholesterol for 28 days. Crude tea catechins prepared from green tea powder were supplemented at a 1% and 2% of the lard-cholesterol diet. The addition of 2% tea catechins slightly depressed growth but at the 1% level was without effect. Tea catechins decreased plasma total cholesterol, cholesterol ester, total cholesterol--HDL-cholesterol (VIDL-+LDL-cholesterol) and atherogenic index (VLDL-+LDL-cholesterol/HDL-cholesterol). Hematocrit and plasma glucose were not altered by the addition of tea catechins. The liver weight, liver total lipids and cholesterol concentrations in rats fed the lard-cholesterol diet increased more than in the control rats, but the addition of tea catechins to the lard-cholesterol diet decreased those parameters. Tea catechin supplementation increased fecal excretion of total lipids and cholesterol. The results demonstrate that tea catechins exert a hypocholesterolemic effect in cholesterol-fed rats.

Animals↗
PubMed1986

[Clinical evaluation of a new tumor marker, CA 15-3, in breast cancer; a comparative study with CEA].

Recently, a new RIA method has been developed by Centocor Co., utilizing the monoclonal antibody CA 15-3. We performed a clinical trial to evaluate its utility as a tumor marker for breast cancer in comparison with CEA. We set 15 U/ml as the cut-off value of serum CA 15-3 level from results acquired from controls; 10 volunteers and 17 patients with non-malignant diseases. The CA 15-3 positive rate among the cases of primary breast cancer was 13.3%, which was of poor diagnostic value. In the recurrent cases the positive rate of CA 15-3 was 72.0%, which was valuable compared with that of serum CEA, 52.0%. In the cases of primary cancers other than breast cancer, the positive rate of CA 15-3 was 6.9%.

Adult↗