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Biomedical subjects

H Ono

Publications and source records attributed to H Ono.

828 records · Page 46Linked to original sources
PubMedDate not supplied

Cerebral thrombosis and microcirculation of the rat during the oestrous cycle and after ovariectomy.

1. The effects of oestrogen on thrombogenesis and the cerebral microcirculation of the female rat were studied during the oestrous cycle and after ovariectomy. 2. Serum levels of oestradiol (E2) and plasma concentrations of nitric oxide (NO) metabolites were significantly greater at pro-oestrus than at dioestrus. Blood vessel diameter, mean red cell velocity, wall shear rate and blood flow at pro-oestrus were significantly higher than at dioestrus. Thrombotic tendency, assessed using a He-Ne laser-induced thrombosis model, was significantly decreased at pro-oestrus compared with dioestrus. 3. The long-term deprivation of oestrogen by ovariectomy significantly depressed serum levels of E2 and plasma concentrations of NO metabolites. Thrombotic tendency was significantly increased 4 weeks after ovariectomy. Vessel diameter, mean red cell velocity, wall shear rate and blood flow in pial arterioles were significantly reduced after ovariectomy. 4. Exogenous administration of oestrogen (17 beta-oestradiol) after surgery reversed the increased thrombotic tendency mediated by ovariectomy. 5. These results strongly indicate that oestrogen mediates beneficial effects on the cerebral microcirculation and moderates cerebral thrombotic mechanisms in the female rat.

Animals↗
PubMedDate not supplied

Distribution of trace metals in nuclei and nucleoli of normal and regenerating rat liver with special reference to the different behavior of nickel and chromium.

The distribution of some metals in nuclei and nucleoli of normal and regenerating rat liver was determined. The contents of Ca, Zn, Cu, and Mn in nuclei were less than 3% of those in whole cells. Cr and Ni, which are known carcinogens, were present in cells in much smaller amounts than the metals above, but their contents in nuclei were more than 20% of those in cells. All of these metals were retained in nucleoli; the contents in nucleoli, per milligram of protein, were 3 (Zn) to 18 (Ni) times those in nuclei. Binding of Cr and Ni to nucleoli was more resistant than that of the other metals to treatment with nucleases. The concentrations of Ca, Zn, Cu, and Mn in nuclei and nucleoli changed synchronously with changes in the amounts of nucleic acids and protein in the corresponding fraction of the regenerating liver after partial hepatectomy. The Cr concentration showed no such synchronization.

Animals↗
PubMedDate not supplied

Comparison of the effects of amlodipine and losartan on 24-hour ambulatory blood pressure in hypertensive patients.

Effects of amlodipine (AML), a long-acting calcium antagonist, and losartan (LOS), an angiotensin II receptor antagonist, on 24-hr blood pressure profile were compared in 15 patients with essential hypertension. After 4 weeks of placebo period, the patients were treated with AML or LOS in a random crossover design for 12-16 weeks each. Either drug was given once daily at 0800 and the doses were titrated so that the office blood pressure was reduced lower than 140/90mmHg. At the end of each period, 24-hr blood pressure was monitored. Average office blood pressure was lowered from 158 +/- 2/ 98 +/- 2 mmHg to 134 +/- 1/87 +/- 1 mmHg by AML and 134 +/- 2/88 +/- 1 mmHg by LOS. Average 24-hr blood pressure was also reduced from 144 +/- 3/ 92 +/- 2 mmHg to 131 +/- 2/84 +/- 2 mmHg by AML and 135 +/- 3/85 +/- 2 mmHg by LOS. The averaged 24-hr systolic blood pressure was significantly lower in AML than in LOS (p < 0.05). Then, the 24-hr blood pressure was analyzed for four segments; morning (0530-0900 h), daytime (0930-1800 h), evening (1830-2300 h) and night (2330-0500 h). Although the daytime blood pressure was comparable between AML and LOS, systolic blood pressure in the evening and morning hours were lower in AML than in LOS (133 +/- 2 vs. 138 +/- 3mmHg,p<0.01; 129 +/- 3 vs. 134 +/- 4,p<0.05). Troughtopeakratio of antihypertensive effect on systolic blood pressure was significantly greater in AML than in LOS (62 +/- 5% vs. 55 +/- 4%, p < 0.05). Either drug did not cause reflective increase in pulse rate over 24 hours. These results suggest that both AML and LOS are equally effective in lowering daytime blood pressure without eliciting reflex tachycardia, however, the antihypertensive effect of AML lasts longer than that of LOS. Such information seems important to achieve 24-hr blood pressure control using these drugs.

Adult↗
PubMedDate not supplied

Variation of repetitive DNA and its phylogenetic relation in Hynobiidae (Caudata).

Middle repetitive (MR) DNA comprising about 35% of the genomic DNA of Hynobius retardatus was isolated and used as mixed probes. A 1.3-kb Bam HI fragment, the major repeating unit of the extensively amplified sequences in H. retardatus, was cloned, sequenced, and used as a probe. Dot blot hybridization under the conditions of probe excess revealed that the MR DNA sequences were shared among the three salamander genera belonging to the family Hynobiidae. However, a large difference in the amount of common sequences was found between Hynobius and Salamandrella, and large differences in both amounts and sequence similarity were found between Hynobius and Onychodactylus. Even among species belonging to the genus Hynobius, relative contents of sequences common to the H. retardatus MR DNA were 20% to 50%. Partially related sequences to the 1.3-kb sequence seemed to be present in all the species of Hynobius and Salamandrella, but the extensive amplification was found only in H. retardatus. Based on the relative contents of the common MR DNA and previously reported chromosomal banding characteristics, species in the genus Hynobius are classified into at least three groups. An evolutionary aspect of the emergence of the amplified sequence in H. retardatus is discussed.

Animals↗
PubMedDate not supplied

Pulmonary vein and left atrial invasion by lung cancer: assessment by breath-hold gadolinium-enhanced three-dimensional MR angiography.

PURPOSE: The purpose of this work was to evaluate the ability of breath-hold gadolinium-enhanced three-dimensional (3D) MR angiography to assess the invasion of the pulmonary vein and the left atrium by lung cancer. METHOD: Gadolinium-enhanced 3D MR angiography was performed in 20 consecutive patients with lung cancer. RESULTS: At two sites with left atrial invasion shown by MR angiography, associated partial resection of the left atrium was performed. At five sites with invasion of the proximal pulmonary vein within 1.5 cm from the left atrium on MR, partial resection of the left atrium was performed at one site, and the pulmonary vein was resected at the intrapericardial portion at three sites. At two sites with invasion of the proximal pulmonary vein 1.5 cm more distal to the left atrium, the pulmonary vein was resected at the extrapericardial portion. CONCLUSION: Breath-hold gadolinium-enhanced 3D MR angiography is suitable for assessing invasion of the pulmonary vein and the left atrium by lung cancer.

Adult↗
PubMedDate not supplied

Vasodilating effects of perhexiline, glyceryl trinitrate, and verapamil on the coronary, femoral, renal, and mesenteric vasculature of the dog.

We compared the vasodilator effects of perhexiline on canine coronary, femoral, renal, and mesenteric arteries with those of glyceryl trinitrate and verapamil. Intravenous perhexiline produced vasodilation of all four vascular beds and decreased peripheral vascular resistance. High doses of perhexiline sometimes increased peripheral vascular resistance and reduced peripheral blood flow. This increase in resistance was abolished by hexamethonium. Intra-arterial perhexiline caused dose-dependent dilation in all four vascular beds without selectivity for the coronary circulation. Neither the autonomic nervous system nor inhibition of adenosine deaminase was involved in the vasodilator action of perhexiline. Perhexiline abolished renal blood flow autoregulation, an effect which was reversed by simultaneous administration of CaCl2. These results suggest that the vasodilator effect of perhexiline is mediated by its Ca2+-antagonistic activity. However, some differences in its effects from those of other Ca2+-antagonists remain to be clarified.

Animals↗
PubMedDate not supplied

Effect of perhexiline on atrioventricular nodal function of anesthetized dogs.

We investigated the effects of perhexiline, a calcium-antagonistic vasodilator, on atrioventricular (AV) conduction in anesthetized open-chest dogs and in isolated, blood-perfused AV node preparations of the dog. Perhexiline, 3 mg/kg, prolonged the AV conduction time from 103.0 +/- 4.4 to 115.3 +/- 4.0 msec (p less than 0.05) in dogs with intact cardiac nerves. In dogs on which vagotomy and stellectomy had been performed, basal AV conduction time was 119.0 +/- 5.0 msec; 3 mg/kg of perhexiline barely prolonged it (121.0 +/- 7.0 msec). Thus, the negative dromotropic effect of perhexiline was abolished by denervation. The functional refractory period of the AV node was also lengthened with 3 mg/kg of perhexiline in the nerve-intact dogs (from 246.0 +/- 15.7) to 270.0 +/- 15.5 msec), but was scarcely affected by perhexiline in the cardiac denervated dogs (from 296.7 +/- 15.7 to 303.2 +/- 13.6 msec). Verapamil, 0.1-0.3 mg/kg, exerted a negative dromotropic effect in both innervated and denervated hearts. A direct inhibitory effect of perhexiline on AV conduction was observed in isolated blood-perfused AV node preparations, but it was much weaker when compared with that of verapamil.

Animals↗
PubMedDate not supplied

Effects of glucagon on pancreatic secretion in the dog.

1. The effects of glucagon on the secretion of pancreatic juice were investigated using blood-perfused canine pancreas preparations. 2. Intravenous administration of glucagon (3-30 mug/kg) to the donor dog elicited a dose-dependent increase in pancreatic secretion. Intra-arterial administration of glucagon (10-100 mug) into the perfused pancreas also elicited increased secretion. 3. There were slight increases in amylase concentration of the pancreatic juice with the largest doses of glucagon given by either route. 4. Glucagon-induced secretion was not modified by treatment with phentolamine, propranolol, atropine, guanethidine, tetradotoxin, haloperidol, prostaglandin F2alpha or calcitonin. 5. The results suggest that glucagon acts directly on the exocrine cells of the canine pancreas.

Amylases↗
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Verapamil-induced contracture in an excised, blood-perfused skeletal muscle preparation from the dog.

The ability of verapamil to induce a contractile response in skeletal muscle was investigated using the canine isolated, blood-perfused diaphragm preparation. Verapamil-induced contracture was characterized by a biphasic increase in muscle tension consisting of an initial phasic and subsequent tonic contracture. The second tonic component of the verapamil-induced contracture was inhibited by procaine, but procaine had no effect on the initial phasic contracture. Verapamil potentiated both KCl- and caffeine-induced contractures during the second tonic stage. This action might be explained by enhancement by the drug of availability, or by an increased sensitivity of the contractile machinery to calcium liberated by membrane depolarization or by the calcium-induced calcium release mechanism. The second tonic component of verapamil-induced contracture was much less than the initial phasic component. It seems, therefore, that the calcium release induced by the procaine-resistant process is the principal action of verapamil in inducing contracture in skeletal muscle.

Animals↗
PubMedDate not supplied

Clinical results of hearing aid with noise-level-controlled selective amplification.

We have developed a hearing aid which reduces the low-frequency energy of the input sound according to the input noise level and the spectrum of the environmental noise. The results of speech discrimination tests using speech in noise in 70 hearing-impaired subjects showed improvement in word discrimination scores in noise of over 15% for 50 of 53 subjects with sensorineural hearing loss. This group of hearing-impaired patients was subdivided into categories according to (a) audiogram type [flat, sloping (i.e. gradual high-frequency loss) and abruptly falling (steep high-frequency slope)]; (b) degree of hearing loss (less than or more than 50 dB average loss) and (c) etiology (familial deafness, presbyacusis). Results on 17 subjects with conductive or mixed hearing impairments showed no improvement, but expressed a preference for this system. The subject reported that the sound was more natural and quiet compared with the conventional AGC hearing aids.

Adolescent↗
PubMedDate not supplied

The origin of extragonadal teratoma: case report of an immature teratoma occurring in a prenatal brain.

We describe a massive congenital intracranial teratoma (MCIT), which had a normal chromosome banding pattern 46,XY karyotype and a normal diploid DNA histogram, and which produced a variety of carcinoembryonic antigens. The volume density of primitive neural components (primitive neural tubes, small undifferentiated neuroepithelial cells, immature glial fibers and pigment cell components without neurofibrillar differentiation) was estimated to be 45%. We discuss the histogenesis, pathobiology and cell cycle kinetics.

Adult↗
PubMedDate not supplied

Diagnostic capability and rational resectional surgery for early gallbladder cancer.

Gallbladder carcinoma limited to the mucosa (pT1a) or muscularis proper (pT1b) with no lymph node metastasis (stage I) is defined as early carcinoma of the gallbladder. Eleven patients with early carcinoma of the gallbladder, treated by either simple or extended cholecystectomy (cholecystectomy plus wedge resection of the gallbladder bed of the liver and lymphadenectomy), were reviewed to determine the diagnostic capability and to clarify the rational resectional procedure for this stage of the disease. A definitive pre-operative diagnosis was made in only 2 patients with pT1b tumors. Most of the remaining 9 patients were diagnosed incidentally after cholecystectomy for polyps or stones. Among 7 patients with pT1a tumors, 5 underwent simple cholecystectomy and 2 underwent extended cholecystectomy. All 7 patients survived with a recurrence-free condition for 5 years or more following the operation. Two patients with pT1b tumors, however, died of a local recurrence or bile duct carcinoma following simple cholecystectomy. Two patients with pT1b tumors who were correctly diagnosed before the operation and underwent extended cholecystectomy survived without recurrence. It is concluded that patients with pT1a tumors can be successfully treated by simple cholecystectomy, while patients with pT1b tumors require extended cholecystectomy.

Adult↗
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Elevation of glutathione in RAW 264.7 cells by low-dose gamma-ray irradiation and its responsibility for the appearance of radioresistance.

We examined the relationship between the induction of glutathione (GSH) level in macrophage-like RAW 264.7 cells by a low (adapting) dose gamma-rays and the cell damage caused by a lethal dose of gamma-rays at various intervals after the adapting dose. The reduced glutathione (GSH) level increased soon after exposure of the cells to 25 cGy of gamma-rays, peaked between 3 hr and 6 hr, and returned almost to the zero time (0 hr) level by 24 hr post-irradiation. Cell damage was assessed by measuring the 3H-thymidine (3H-TdR) incorporation into cellular DNA. gamma-Ray irradiation produced a dose-dependent cell damage in RAW cells, causing about 40% and 60% inhibition of 3H-TdR incorporation into DNA at 1.0 Gy and 2.0 Gy, respectively, as compared with non-irradiated cells. Treatment with the adapting dose of 25 cGy at 1 hr or 24 hr before the lethal irradiation was ineffective. However, pre-irradiation with 25 cGy at 3 hr or 6 hr prior to lethal irradiation inhibited the decrease of 3H-TdR incorporation into DNA, indicating a protective effect. GSH exogenously added to the medium also inhibited the cell damage induced by lethal doses of gamma-Rays in a dose-dependent manner. These results indicate that the induction of endogenous GSH in living cells immediately following low-dose gamma-Ray irradiation is at least partially responsible for the appearance of radioresistance to a subsequent lethal dose of radiation, and may make it possible to use higher doses of radiation in radiotherapy for tumor patients.

Animals↗
PubMedDate not supplied

Early gastric cancer: endoscopic mucosal resection.

In Japan, endoscopic mucosal resection (EMR) is now accepted as a treatment option for cases of early gastric cancer (EGC) with minimum probability of associated lymph node metastasis. In National Cancer Center Hospital (NCCH), EMR is currently applied to patients with early cancers up to 30 mm diameter that were of intestinal type, and were superficially elevated and/or depressed (Type I, IIa and IIc) but without ulceration or definite signs of submucosal invasion. Four hundred seventy nine lesions of EGC in 449 patients were treated by EMR from 1987 through 1998. Submucosal invasion was found on subsequent pathologic examination in 74 lesions, and surgery was recommended. Sixty nine percent of intramucosal cancer was resected with a clear margin, which was therefore judged to be a "complete resection". Local recurrence in the stomach occurred in 2% (5 lesions) with complete resection and in 17% (18 lesions) without complete resection treated conservatively or endoscopically, and all were subsequently treated with curative intent. There were no gastric cancer-related deaths for a median follow-up period of 38 months (3-120 months). Bleeding and perforation were two major complications in EMR, but there were no treatment-related deaths. We believe that EMR allows us to perform less-invasive treatment without sacrificing the possibility of cure. We hope to promote its use around the world.

Gastric Mucosa↗
PubMedDate not supplied

Reactivities of antiphospholipid antibodies to blood cells and their effects on platelet aggregations in vitro.

To clarify the pathogenesis of antiphospholipid antibody (aPL) syndrome, the reactivities of anticardiolipin antibodies (aCL) in sera of patients with systemic lupus erythematosus (SLE) or other diseases to fresh, activated or destroyed blood cells were examined by the inhibition assay using an enzyme-linked immunosorbent assay. In addition, the effects of lupus anticoagulants (LA) in the patients' plasma and of immune complexes formed between LA and PL antigens on platelet aggregations were also determined. The IgG-aCL activity of patients' sera was markedly inhibited by pre-incubation with freeze-thawed blood cells, including erythrocytes (RBC), mononuclear cells (MNC) and platelets, but not fresh platelets or RBC. The aCL activity was slightly inhibited by fresh MNC, and was definitely inhibited by thrombin-activated platelets and polymorphonuclear cells (PMN) stimulated with phorbol 12-myristate 13-acetate (PMA). However, the activity was not inhibited by platelets stimulated with adenosine 5'-diphosphate (ADP; 10 microM). Twenty-two LA positive plasma and 17 LA negative plasma from patients similarly enhanced the aggregation of platelets which were obtained from healthy adults and stimulated with low concentrations of ADP (1 or 2 microM). However, such enhancement of platelet aggregation was not observed when high concentrations of ADP (5 microM) or collagen (2 micrograms/ml) were used as stimulators. In four of the 16 LA positive plasma examined, the mixture of plasma and phospholipid reagent for activated partial thromboplastin time induced platelet aggregations without the other stimulations, but the plasmas themselves did not induce such a reaction. The above results indicate that the aPL from patients do not react with intact blood cells in vitro, but they can react with activated or destroyed blood cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies↗