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Biomedical subjects

H Ono

Publications and source records attributed to H Ono.

At least 199 records · Page 11Linked to original sources
PubMed1998

Actions of calcitonin gene-related peptide on a population of submandibular ganglion cells.

In this study, we analyzed the effect of alpha-calcitonin gene-related peptide (CGRP) on the neurons of hamster submandibular ganglion (SMG). CGRP induced a small slow-depolarization accompanied with an increase in input resistance in about 60% of tested cells. CGRP enhanced durations of their Ca2+ spikes. The Ca2+ spikes were subdivided into two subgroups according to duration short duration within 1 sec and long duration of more than 1 sec. Forskolin, an activator of adenylate cyclase, mimicked the effects of CGRP. These data indicated that the effects of CGRP on SMG cells were mediated via the intracellular cyclic AMP signalling system. The effect of CGRP on the voltage-activated Ca2+ currents was characterized by enhancement of both transient and sustained components. The enhancement was greater in the transient component than in the sustained component. The subgroups of the Ca2+ spike may indicate differences in mechanism accelerating transmitter release and may reflect distinct functional roles of two different populations of SMG cells.

Afferent Pathways↗
PubMed1998

Genetic analysis of dental traits in 82 pairs of female-female twins.

OBJECTIVE: To study systematically the heritability of dental traits. METHODS: Eighty-two pairs of female-female twins from 6 to 12 years old were collected. Twin zygosity diagnosis was made by DNA fingerprinting. The study was composed of questionnaires, oral examinations, model measurements, and panoramic radiographs. The same analytic method was used for each of the dental traits and comparison of their heritability was made. RESULTS AND CONCLUSIONS: According to the significance of difference and the level of heritability, the dental traits were divided into four types: strong, median, weak, and weaker heritability. The number of third molars present, tooth size, arch size, and upper lateral incisor malformation were under strong genetic influence; hypodontia indicated a median heritability; a weak heritability was seen in tooth eruption and caries, and a weaker heritability was found in occlusal traits. The division made it easy to learn the genetic characteristics of dental traits systematically and supplemented the theory of dental genetics.

Anodontia↗
PubMed1998

[A case report of successful mitral valve replacement for infective endocarditis during pregnancy].

Infective endocarditis is an important but uncommon complication in obstetric or gynecologic practice. A 32 weeks' pregnant woman exhibited endocarditis due to Streptococcus oralis. The present case was successfully managed by means of aggressive antibiotic and diuretic treatments appropriate for endocarditis. The patient entered spontaneous labor at the estimated date of confinement and delivered of healthy 2.8 kg boy. After four weeks later scheduled mitral valve replacement with SJM valve was performed at the chronic stage of endocarditis. Her postoperative recovery was uneventful and she was discharged 40 days after the operation.

Adult↗
PubMed1998

[Propofol-air-oxygen anesthesia reduces the incidence of sore throat after laryngeal mask anesthesia].

We investigated the effects of the presence or absence of N2O in propofol anesthesia using a laryngeal mask on the incidence of postoperative sore throat. In the N2O-combined anesthesia group (n = 25), score 0 (no sore throat) was observed in 11 patients; score 1 (slight pain and discomfort that improved on the next day of operation) in 9; and score 2 (persistent pain on the next day) in 5. In the non-N2O-combined anesthesia group (n = 25), score 0 was observed in 21 patients, score 1 in 3; and score 2 in 1, showing a significantly lower incidence of sore throat and milder sore throat than in the N2O-combined anesthesia group. These results suggest that propofol anesthesia using a laryngeal mask not combined with N2O reduces the incidence of postoperative sore throat.

Adult↗
PubMed1997

Characterization of alpha1-adrenoceptor subtypes in facilitation of rat spinal motoneuron activity.

The subtypes of alpha1-adrenoceptor mediating facilitation of alpha-motoneuron activity in adult rat spinal cord were examined. The potencies of agonists and antagonists were compared, using extracellular single unit recordings made in spinal cord slices isolated from adult rats. Catecholamines (epinephrine, norepinephrine), phenylethylamines (phenylephrine, methoxamine) and imidazolines (clonidine, oxymetazoline, St587 (2-(2-chloro-5-trifluoromethyl-phenylimino)-imidazoline)) enhanced motoneuron activity. Catecholamines and phenylethylamines elicited maximal responses but imidazolines elicited submaximal responses. The potencies of the agonists were similar to their affinities for alpha1A-adrenoceptors. The alpha1A-adrenoceptor agonist SDZ NVI 085 ((-)-(4aR,10aR)-3,4,4a,5,10,10a-hexahydro-6-methoxy-4-methyl-9-methylthio-2H-naphth[2,3b]-1,4-oxazine) behaved as a partial agonist with a maximal response of about 75% and this response was not inhibited by chloroethylclonidine. Pretreatment with chloroethylclonidine produced a rightward shift of the phenylephrine response curve but caused little reduction in the maximal response. Prazosin, 5-methyl-urapidil, WB4101 (2-([2,6-dimethoxyphenoxyethyl] aminomethyl)-1,4-benzodioxane) and BMY7378 (8-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-8azaspiro[4.5]decane-7,9-dione dihydrochloride) concentration dependently inhibited the facilitation of alpha-motoneuron activity produced by phenylephrine. The order of inhibitory potency was similar to that for their alpha1A-adrenoceptor binding site affinity. Therefore, it seems that alpha1A-adrenoceptors may be functionally predominant in the facilitation of rat spinal motoneuron activity.

Adrenergic alpha-1 Receptor Agonists↗
PubMed1997

Deacetylation of chitin oligosaccharides of dp 2-4 by chitin deacetylase from Colletotrichum lindemuthianum.

Chitin oligosaccharides of degree of polymerization 2-4 were deacetylated by purified chitin deacetylase isolated from Colletotrichum lindemuthianum to give their corresponding breakdown products after purification by liquid chromatography. Data from FABMS analyses suggested that N,N',N",N"'-tetraacetylchitotetraose and N,N',N"-triacetylchitotriose were converted into fully-deacetylated corresponding chitosan oligomers. Conversely, N,N'-diacetylchitobiose [(GlcNAc)2] was deacetylated to give a product which showed an [M + H]+ pseudomolecular ion at m/z 383, suggesting that either of the two acetyl groups were removed. Further data from 1H NMR analyses confirmed that the reaction product was 2-acetamido-4-O-(2-amino-2-deoxy-beta-D-glucopyranosyl)-2-deoxy-D-glucos e [GlcN-GlcNAc]. The enzymatic method has three advantageous characteristics over chemical methods: (i) it does not cause unexpected degradation of the sugar chain, (ii) it is highly reproducible, and (iii) unique compounds such as GlcN-GlcNAc may be produced.

Amidohydrolases↗
PubMed1997

Characterization of peripheral blood T-lymphocytes transduced with HTLV-I Tax mutants with different trans-activating phenotypes.

Tax1, a transcriptional trans-activator of the Human T-cell leukemia virus type I (HTLV-I), induces the expression of many cellular genes through interaction with at least three distinct cellular transcription factors; CREB/ATF, NF-kappaB, and SRF. This Tax1-induced activation of cellular genes is considered to be a critical event in T-cell transformation by HTLV-I. To elucidate the role of each Tax1-inducible transcriptional pathway in T-cell transformation, we introduced Tax1 mutants with different trans-activating phenotypes into peripheral blood lymphocytes (PBL) by retroviral vectors. Analysis of these PBLs revealed that activation of the NF-kappaB pathway is sufficient to promote the growth response to IL-2. However, for the clonal expansion of CD4+ T-cells, which is a characteristic result of HTLV-I infection, activation of the CREB/ATF and SRF pathways is also required.

CD4-Positive T-Lymphocytes↗
PubMed1997

Aberrant expression and function of p53 in T-cells immortalized by HTLV-I Tax1.

The expression and function of p53 tumor suppressor protein was investigated in T-cells immortalized by the Tax1 protein of HTLV-I. Conformationally wild-type p53 was expressed at elevated levels in Tax1-immortalized T-cells by post-transcriptional mechanisms when compared with normal T-cells. Luciferase assays with a reporter plasmid containing p53-binding sites revealed an impairment in the transactivating function of p53 in Tax1-immortalized T-cells. Our results suggest an important role for Tax1 in the aberrant expression and function of p53 observed in many HTLV-I transformed cells.

CD4-Positive T-Lymphocytes↗
PubMed1997

Age-related differences and roles of endothelial nitric oxide and prostanoids in angiotensin II responses of isolated, perfused mesenteric arteries and veins of rats.

We examined whether or not cyclo-oxygenase products of arachidonic acid and endothelium-derived relaxing factor (nitric oxide, NO) regulate the vascular response to angiotensin II differently with aging or development. For this purpose angiotensin II responses of isolated, perfused rat mesenteric vascular beds were compared between rats aged 4 weeks and 32 weeks. Angiotensin II increased perfusion pressure in arteries and veins of both rats aged 4 weeks and 32 weeks. In the arteries of rats aged 32 weeks the increase was slight, and less than that in rats aged 4 weeks. In contrast, the veins showed similar increases in perfusion pressure in rats aged 4 weeks and 32 weeks. Indomethacin, an inhibitor of cyclo-oxygenase, at 5 x 10(-6) M depressed the increase in perfusion pressure only in the arteries of rats aged 32 weeks. NG-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide (NO) synthase, applied at 5 x 10(-6) M in the presence of indomethacin enlarged the perfusion pressure increase in the arteries of both rats aged 4 weeks and 32 weeks, while it failed to modify that in the veins. After removal of the endothelium from the blood vessels, the perfusion pressure responses in arteries were increased in both rats aged 4 weeks and 32 weeks, whereas those in veins were not affected. Regardless of the endothelium being intact or removed, the increase in arterial perfusion pressure of rats aged 32 weeks all but disappeared with 5 x 10(-6) M furegrelate, an inhibitor of thromboxane A2 synthase, and with a combined application of furegrelate and 10(-6) M SQ29,548, a blocker of thromboxane A2/prostaglandin H2 receptors. These results indicate the following: in rat mesenteric vascular beds the angiotensin II response in the arteries appears to diminish with aging or development, whereas that in the veins does not change. The NO released from the endothelium regulates the arterial response but vasodilating prostanoids have no role in the response. Moreover, in the arteries of rats aged 32 weeks, vasoconstricting prostanoids, such as prostaglandin H2 and thromboxane A2, seem to play a role in angiotensin II-induced vasoconstriction. With aging or development, and depending on the type of blood vessel, NO and prostanoids appear to modify the angiotensin II response differently.

Aging↗
PubMed1997

Non-invasive determination of instantaneous heart rate in developing avian embryos by means of acoustocardiogram.

Previous noninvasive studies of the mean heart rate of embryonic birds have prompted an investigation into the instantaneous heart rate (IHR), which may be informative in developmental studies of cardiac rhythm. Using the acoustocardiogram (ACG), a noninvasive, long-term measuring system for embryonic IHR is developed, and the IHR in chickens during the last half of embryonic development is determined. The system, which uses a micro-computer, samples the ACG at a frequency of 50 Hz, restores the ACG wave by sinc function and calculates the IHR with an error in accuracy of less than 1 beat min-1. It was found that characteristic, transient bradycardia begins to appear late in the second week of incubation, and, with the additional development of transient tachycardia, the embryonic cardiac rhythm becomes more arrhythmic towards hatching. Simultaneous measurements of IHR with somatic movements showed no relationship between arrhythmia and embryonic activities. This system is useful, providing new evidence on long-term IHR developmental patterns.

Animals↗
PubMed1997

Ballistocardiogram of avian eggs determined by an electromagnetic induction coil.

As an avian embryo grows within an eggshell, the whole egg is moved by embryonic activity and also by the embryonic heartbeat. A technical interest in detecting minute biological movements has prompted the development of techniques and systems to measure the cardiogenic ballistic movement of the egg or ballistocardiogram (BCG). In this context, there is interest in using an electromagnetic induction coil (solenoid) as another simple sensor to measure the BCG and examining its possibility for BCG measurement. A small permanent magnet is attached tightly to the surface of an incubated egg, and then the egg with the magnet is placed in a solenoid. Preliminary model analysis is made to design a setup of the egg, magnet and solenoid coupling system. Then, simultaneous measurement with a laser displacement measuring system, developed previously, is made for chicken eggs, indicating that the solenoid detects the minute cardiogenic ballistic movements and that the BCG determined is a measure of the velocity of egg movements.

Animals↗
PubMed1997

Elevated plasma bile acids in hypergalactosaemic neonates: a diagnostic clue to portosystemic shunts.

UNLABELLED: To determine whether plasma levels of total bile acids may provide a useful index for hypergalactosaemia due to porto-systemic shunts, these levels were determined in hypergalactosaemic neonates. Increased levels were found in all cases with portohepatic venous or portocaval shunts. The levels of both total bile acids and galactose were normalized when the shunts disappeared on the echograms. Both bile acids and galactose are almost completely absorbed by the liver via the first portal blood passage. Portosystemic shunts contribute to elevated levels of bile acids and galactose. CONCLUSION: Increased plasma levels of total bile acids serve as a diagnostic clue to the presence of portosystemic shunts in neonates with hypergalactosaemia.

Arteriovenous Malformations↗
PubMed1997

Nephrosclerosis and hypertension.

In patients with benign nephrosclerosis, the histologic changes are characterized by hyaline degeneration of afferent arterioles with reduced kidney size. Although the glomeruli are nearly intact in patients with adult essential hypertension, the greatest numbers of sclerotic glomeruli are seen in nephrosclerosis with the aging process. Aging undoubtedly plays a role. In the authors' experience, the kidney of an elderly subject, although with normotensive pressure and normal level of cholesterol, shows an increased mesangial matrix and hypertrophic vascular medial smooth muscle cells. Kidneys of elderly subjects also are associated with a large number of sclerotic glomeruli. Experimental evidence supports the notion that the pathogenesis of glomerulosclerosis with nephrosclerosis has been demonstrated as important factors: (1) the elevation of PG (glomerular hypertension); (2) mesangial dysfunction, such as mesangiolysis and increased mesangial matrix; and (3) genetic abnormalities (apoptosis) in mesangial cells with glomerular hypertension. Malignant nephrosclerosis is characterized histologically by vascular endothelial damage and fibrinoid necrosis of afferent and interlobular arteries. In an afferent arteriole or a glomerulus, NOS or endothelin produced in endothelial cells may play a role in the reduction or the maintenance of vascular tone. The frequency of malignant hypertension has decreased because of the effective treatment of essential hypertension with new antihypertensive agents: calcium antagonists, ACE inhibitors, and angiotensin II receptor antagonists. Therefore, the importance of the prevention of essential hypertension with these antihypertensive agents, by slowing and stopping the increase in blood pressure from mild hypertension, has received widespread recognition in the prevention of organ damage, such as cases of cardiovascular disease and ESRD. Thus, prevention of renal injuries is an important goal of antihypertensive therapy.

Animals↗
PubMed1997

Plasma total homocysteine concentrations in epileptic patients taking anticonvulsants.

Plasma total homocysteine (tHcy) and serum folate (FA) concentrations were measured in 130 epileptic patients taking anticonvulsant drugs. A significant inverse correlation was found between FA and tHcy. This was greater in the older group (> or = 15 years) than in the younger group (1 to 14 years). There were four FA-deficient patients (FA concentration < 3 ng/mL regardless of symptoms), including three patients in the older group and one in the younger group. All FA-deficient patients had received long-term treatment (> 7 years) with multiple anticonvulsants. Their tHcy levels were higher than the 90th percentile of those in control subjects. Two patients showed extremely high levels of tHcy (57.9 and 29.1 mumol/L) and subnormal plasma methionine levels. After FA therapy, their tHcy decreased to levels the same as or less than those of control subjects and FA increased to above the normal range. Based on these findings, we conclude that measuring FA and tHcy concentrations may be useful for preventing thrombosis due to hyperhomocysteinemia in epileptic patients taking anticonvulsants, particularly those who receive long-term treatment with multiple agents.

Adolescent↗
PubMed1997

Trial of duplication procedure for complete dentures by CAD/CAM.

The purpose of this study was to duplicate the shapes of complete dentures by using a computer-aided design/manufacturing (CAD/CAM) system. The shapes of the complete dentures of an edentulous patient were measured using a non-contact type shape measurement system and morphological data at the interval of 0.25 mm were obtained in the X-axis and Y-axis directions. Measurement was performed from the occlusal surface and mucosal surface sides. Based on the three-dimensional morphological data, cutter paths for cutting were generated. For cutting, the three-step method consisting of rough cutting, finish cutting, and partial finish cutting was used and for duplicating the dentures the modelling wax was cut using a computerized numerical control (CNC) processor and ball-end mills with diameters of 6 mm and 1 mm. The method for the controlling of three axes (X, Y, and Z) of CNC machine was used, and cutting was performed only from two directions. Although further improvements are needed in the measurement and cutting in acute slope areas, the duplication of complete dentures appears to be possible using the CAD/CAM system.

Analog-Digital Conversion↗
PubMed1997

Application of a three-dimensional reconstruction method to analysis of the residual ridge.

The purpose of this study was to develop a new method of analysing the shape of the residual ridge. The line of the residual ridge crest was regarded as the reference for artificial tooth arrangement and a method of determining it was evaluated. The shape of a plaster model was measured with a contact-type shape measurement system. The measurement data in each frontal section were interpolated by cubic splines. The points corresponding to the residual ridge crest were calculated and superimposed onto the image of the plaster model on a monitor screen of an image processor. Using these points and the image of the plaster model, the line of the residual ridge crest was marked on the plaster model. It was concluded that this method could be used to determine the line of the residual ridge crest on a plaster model.

Algorithms↗
PubMed1997

Vascular compliance and vasoconstrictive reactions in rat hindlimbs: comparison between storage temperatures of -1 degree C and 4 degrees C.

The vascular compliance and contractility of vascular smooth muscle of rat freshly amputated hindlimbs and hindlimbs preserved at -1 degree C for 12, 24, 48, and 72 hr were evaluated using a fresh blood extracorporeal circulatory system. Vascular compliance was measured under physiologic circulatory conditions (blood pressure of the amputated limb was maintained at 80 to 150 mmHg). Vascular compliance after storage at -1 degree C for 12 hr or longer decreased significantly from that of freshly amputated limbs (p < 0.01). To evaluate the contractility of vascular smooth muscle, the arterial blood pressure in the amputated limbs was transiently increased with injections of norepinephrine. The contractility after storage at -1 degree C for up to 24 hr was not different from that of freshly amputated limbs. However, it decreased significantly after 48 hr or longer. A comparison of these results with an earlier study that used identical methods to investigate limbs preserved at 4 degrees C suggested that storage at -1 degree C was inferior to that at 4 degrees C with respect to vascular compliance, but was superior to storage at 4 degrees C with respect to smooth muscle contractility.

Amputation, Surgical↗