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Biomedical subjects

Y Hara

Publications and source records attributed to Y Hara.

At least 505 records · Page 28Linked to original sources
PubMed1991

Effect of endocrine therapy on a brain metastatic lesion of prostatic carcinoma.

We describe a 62-year-old male with brain metastasis from prostatic carcinoma, which regressed with medical and surgical endocrine therapies. The patient's presenting complaints were left periocular and deep ocular pain and a defect of the left visual field. During treatment of the above symptoms, macrohematuria, dysuria and pollakiuria occurred. Pathological examination of a transrectal needle biopsy disclosed moderately differentiated adenocarcinoma of the prostate. Computerized tomographic scan (CT) and magnetic resonance imaging demonstrated a brain tumor at the frontal skull base and the region of the frontal lobe suspected to be a metastasis of the prostatic carcinoma. One week after a period of daily administration of estramustine phosphate sodium, the prostate was observed to be softened and slightly decreased in size. The visual field defect and disturbance of urination gradually improved. The prostate decreased to normal size and no tumor mass could be detected on the brain CT after 3 months of treatment.

Adenocarcinoma↗
PubMed1991

A rare case of infective aneurysm involving all three sinuses of Valsalva complicated by left single coronary artery.

Infective aneurysm showing dilatation of all three coronary sinuses of Valsalva due to infective endocarditis is extremely rare. We present the first report of such a case complicated by left single coronary artery. The patient was a 55-year-old man with a past history of untreated diabetes mellitus, cerebral infarction, aortic regurgitation and high-grade fever. He was admitted with a complaint of easy fatigability. In a treadmill exercise test, asymptomatic ischemic depression of the ST segment was observed. Two-dimensional echocardiography revealed marked dilatation of all three sinuses of Valsalva, and a mural thrombus within the dilated right sinus of Valsalva. On magnetic resonance imaging, an abnormal signal in the markedly dilated right sinus of Valsalva was revealed. Coronary arteriography showed left single coronary artery (L1 type by Sharbaugh's classification). The histopathological features of the affected aorta were thought to represent the healing stage of infective endocarditis. With regard to the myocardial ischemia in this patient, it was thought to have arisen mainly through aortic regurgitation and coronary atherosclerosis due to single coronary artery, and partly influenced by untreated diabetes mellitus.

Aneurysm, Infected↗
PubMed1991

GABAA and GABAB-receptor agonists evoked vagal nerve efferent transmission in the rat.

The effect of GABA agonists on vagal efferent activity was studied in anesthetized rats. PCPGABA, a GABAB agonist (4 and 8 mg/kg, s.c.), markedly activated the neural efferent discharge of the vagus. Muscimol, a GABAA agonist (0.1 and 0.3 mg/kg, i.v.), also facilitated vagal activity. Both agonists caused significant gastric acid hyperacidity. Bicuculline (0.25 mg/kg, i.v.) or picrotoxin (0.5 mg/kg, i.v.) given 10 min prior to each agonist had no effect on the frequency of vagal nerve firing elicited by PCPGABA (4 mg/kg, s.c.) or muscimol (0.3 mg/kg, i.v.). Pretreatment with scopolamine (0.25 mg/kg, i.v.) abolished PCPGABA stimulated vagal activity and gastric acid secretion. Methscopolamine (0.25 mg/kg, i.v.) inhibited only the hyperacidity evoked by PCPGABA, but not vagal activation. These results suggest that PCPGABA and muscimol may cause gastric acid secretion through central cholinergic descending mechanisms that are resistant to GABAA and GABAB antagonists.

Acetylcholine↗
PubMed1991

The inhibitory effect of tiamulin on high K(+)-induced contraction in guinea pig intestinal smooth muscle.

Tiamulin with an IC50 of 1.7 x 10(-6) M inhibited both the rapid and sustained contractions induced by hyperosmotically added 60 mM K+ (Hyper 60 K+) without changing the membrane potential in the intestinal muscle. Tiamulin inhibition (2 x 10(-6)-2 x 10(-5) M) of the Ca(2+)-induced contraction in depolarized muscle was competitively antagonized by raising external Ca2+. Tiamulin (2 x 10(-5) M) slightly affected the Hyper 60 K(+)-induced phasic contraction under hypoxia and the carbachol-induced phasic contraction. Moreover, tiamulin (2 x 10(-5) M) inhibited the Hyper 60 K(+)-induced contraction with decreasing [Ca2+]cyt level. Although the inhibitory effect of 10(-7)-10(-5) M monesin, an inhibitor of mitochondrial respiration, on the Hyper 60 K(+)-induced contraction was reduced under hypoxia, the effect of tiamulin (2 x 10(-7)-2 x 10(-4) M) was not modified. Tiamulin changed neither the intracellular Na+ and K+ content of the depolarized muscle nor the Ca(2+)-induced contraction in the chemically skinned preparations. These results suggest that the inhibitory action of tiamulin on the Hyper 60 K(+)-induced tonic contraction is possibly due to the competitive inhibition of Ca2+ entry through the voltage-dependent Ca2+ channel of the intestinal smooth muscle cell.

Animals↗
PubMed1991

Disturbance of thyroidal iodine metabolism in BB/W rat.

To investigate the thyroid function in Bio-Breeding Worcester (BB/W) rats, we have examined the iodine metabolism, serum TSH and thyroid hormone levels in 8- and 16-week-old BB/W and normal Wistar (W) rats. At 8 weeks of age, serum TSH levels were significantly higher in BB/W rats than in W rats, although there was no difference in the serum levels of free T3 and free T4. Furthermore, the thyroidal radioactive iodine incorporation at 48 h was significantly lower in BB/W rats, suggesting that they might have some defects in iodine organification. At 16 weeks of age, serum TSH levels were also significantly higher in BB/W rats than in W rats. Furthermore, serum TSH levels in 16-week-old BB/W rats were significantly higher than in 8-week-old BB/W rats. The thyroid weight was significantly greater in BB/W rats, probably due to the increased serum TSH. The thyroidal radioactive iodine uptake at 48 h and the iodine content in the thyroid homogenates were significantly lower in BB/W rats. These results suggest that BB/W rats have some defect in iodine metabolism resulting in impaired thyroid hormone synthesis.

Animals↗
PubMed1991

Prevention of cerebral stroke by arotinolol in salt-loaded SHRSP.

The preventive effects of long-term treatment with arotinolol on the development of cerebral stroke were examined in SHRSP fed a high salt diet. Arotinolol (4.87 mg/kg per day for 20 weeks) prevented cerebral lesions, reduced signs of stroke and delayed early mortality but did not alter blood pressure from control SHRSP, when the administration of the drug was started before the onset of hypertension. At dosage levels similar to arotinolol, both pindolol and labetalol were less effective in preventing cerebral lesions despite lower blood pressure. Propranolol produced no detectable effect on blood pressure or frequency of cerebral lesions. Furthermore, arotinolol (4.27 mg/kg per day) markedly inhibited the development of stroke without blood pressure reduction, when the administration was started after the onset of severe hypertension. These results suggest that arotinolol is more effective in preventing cerebral stroke than pindolol, labetalol and propranolol, and that factors other than blood pressure reduction may be involved in this preventive effect.

Adrenergic beta-Antagonists↗
PubMed1991

[Antifungal and fungicidal activities of tea extract and catechin against Trichophyton].

We examined tea extract, (-) epigallocatechin gallate (EGCg) and theaflavin digallate (TF3) for their antifungal and fungicidal activities against Trichophyton mentagrophytes, T. rubrum, Candida albicans and Cryptococcus neoformans. Tea extract (2.5%) inhibited completely the growth of both T. mentagrophytes and T. rubrum. EGCg at 2.5 mg/ml failed to inhibit their growth, whereas TF3 at 0.5 mg/ml inhibited the growth. EGCg (1mg/ml) showed no fungicidal activity against Trichophyton. TF3 (1mg/ml) killed Trichophyton by a long time contact (72-96 hrs). Tea extract showed a fungicidal activity against Trichophyton in a dose- and contact time-dependent manner. It did not inhibit the growth of C. albicans, but at a high concentration, inhibited slightly the growth of C. neoformans. It had no fungicidal activity against C. albicans or C. neoformans.

Antifungal Agents↗
PubMed1991

[Antibacterial and bactericidal activities of tea extracts and catechins against methicillin resistant Staphylococcus aureus].

We examined tea extract, (-) epigallocatechin gallate (EGCg) and theaflavin digallate (TF3) for their antibacterial and bactericidal activities against methicillin resistant Staphylococcus aureus (MRSA) and food poisoning strains of S. aureus. Twenty percent tea extract (50 microliters), EGCg (63 micrograms) and TF3 (125 micrograms) added to one ml of culture medium each inhibited the growth of all strains of MRSA and food poisoning S. aureus tested. Tea extract showed also a bactericidal activity against MRSA even at the same concentration of as in ordinarily brewed tea. EGCg at a concentration of 250 micrograms/ml showed a bactericidal activity against MRSA but not against food poisoning S. aureus, but at 500 micrograms/ml reduced markedly the viable number within 48h. These results suggest that tea and catechin can be used as prophylactic agents against MRSA infection.

Biflavonoids↗
PubMed1991

Inhibition of rotavirus and enterovirus infections by tea extracts.

Epigallocatechin gallate from green tea and theaflavin digallate from black tea inhibited infections of cultured rhesus monkey kidney MA 104 cells with rotaviruses and enteroviruses. Their antiviral effects were maximally induced when directly added to virus, and their pre- and post-treatment of the cells produced much weak antiviral activity. Antiviral activity of the extracts therefore seems to be attributable to interference with virus adsorption.

Animals↗
PubMed1991

Effect of cholera toxin on serum levels of thyrotropin and thyroid autoantibodies in biobreeding/Tokyo (BB/TKY) rats.

The effect of cholera toxin (CT) on the thyroid-pituitary axis and the immune system was examined in Bio-Breeding/Tokyo (BB/TKY) rats, which spontaneously develop insulin-dependent diabetes mellitus (DM) and lymphocytic thyroiditis (LT). Intravenous administration of CT (5 micrograms/100 g body weight) every other week starting at 6 weeks of age resulted in a significant decrease in the serum thyrotropin (TSH) level at 12 and 14 weeks of age when compared with saline treated littermates. CT stimulated rat thyroid cells to proliferate in vitro. Furthermore, serum anti-thyroglobulin antibody (ATA) titers were also significantly decreased in 14-week-old rats treated with CT. In vitro ATA production by spleen cells from BB/TKY rats was inhibited by CT. Antibodies to thyroxine were detected in both CT-treated and control rats. It is of interest that the ratio of W3/25+ helper/inducer cells to OX8+ suppressor/cytotoxic cells was significantly decreased in CT-treated rats. However, there was no significant difference in the incidence of DM and LT between the two groups of rats. The present study showed that CT suppressed ATA production both in vivo and in vitro, and had a stimulatory effect on thyrocytes in BB/TKY rats.

Animals↗
PubMed1991

[Foreign body stone of the ureter as a complication of acupuncture: report of a case].

A 47-year-old female was admitted to our clinic with the suspicion of ureteral foreign body. She had undergone acupuncture for left lumbago twelve years earlier. Plain X-ray film revealed a linear shadow and calcified shadows laterally to left third lumber vertebra. Computed tomographic scan and pyelogram showed them located in the left ureter. Left ureterolithotomy was performed successfully. The removed stone was accompanied by an acupuncture needle. Including our case, twelve cases of foreign bodies as a complication of acupuncture in the upper urinary tract reported in the Japanese literature were reviewed.

Acupuncture Analgesia↗
PubMed1991

[One-stage operation in a patient with Marfan's syndrome, severe pectus excavatum and annulo-aortic ectasia].

A case of Marfan's syndrome complicated by annulo-aortic ectasia with pectus excavatum (Wada's 3rd grade classification) and aortic regurgitation (Seller's 1st grade) is reported in a 36-year-old man. We performed one-stage operation combining Bentall's procedure for the annulo-aortic ectasia and sternal elevation for the pectus excavatum. Few reports of one-stage operation for pectus excavatum and annulo-aortic ectasia in Marfan's syndrome have been published. If both diseases are present and surgical indications permit, one-stage operation can be performed to ensure protection of the heart and a satisfactory postoperative course. The best approach to the heart to obtain the most favorable operating field and the best chestplasty method that also assures closure of the median sternotomy are important considerations in one-stage operation. The most appropriate combination of these two operational variables must be assessed in each case.

Adult↗