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Biomedical subjects

T Ogata

Publications and source records attributed to T Ogata.

At least 127 records · Page 7Linked to original sources
PubMed1999

Skeletal features and growth patterns in 14 patients with haploinsufficiency of SHOX: implications for the development of Turner syndrome.

We report on clinical features in 14 Japanese patients (4 males and 10 females) with partial monosomy of the short arm pseudoautosomal region involving SHOX (n = 11) or total monosomy of the pseudoautosomal region with no involvement of disease genes on the sex-differential regions (n = 3). Skeletal assessment showed that three patients had no discernible skeletal abnormalities, one patient exhibited short 4th metacarpals and borderline cubitus valgus, and the remaining 10 patients had Madelung deformity and/or mesomelia characteristic of Léri-Weill dyschondrosteosis (LWD), together with short 4th metacarpals and/or cubitus valgus. Skeletal lesions were more severe in females and became obvious with age. Growth evaluation revealed that patients without LWD grew along by the -2 SD growth curve before puberty and showed a normal or exaggerated pubertal growth spurt, whereas those with LWD grew along by the standard growth curves before puberty but exhibited an attenuated pubertal growth spurt and resultant short stature. Maturational assessment indicated a tendency of relatively early maturation in patients with LWD. There was no correlation between the clinical phenotype and the deletion size. These findings suggest that haploinsufficiency of SHOX causes not only short stature but also Turner skeletal anomalies (such as short 4th metacarpals, cubitus valgus, and LWD) and that growth pattern is primarily dependent on the presence or absence of LWD. Because skeletal lesions have occurred in a female-dominant and age-influenced fashion, it is inferred that estrogens exert a maturational effect on skeletal tissues that are susceptible to premature fusion of growth plates because of haploinsufficiency of SHOX, facilitating the development of skeletal lesions.

Adolescent↗
PubMed1999

Estimation of the systolic pulmonary arterial pressure using contrast-enhanced continuous-wave Doppler in patients with trivial tricuspid regurgitation.

Noninvasive estimation of pulmonary arterial pressure is important for hemodynamic monitoring of patients with heart disease. In patients with tricuspid regurgitation (TR), the peak velocity of TR on continuous-wave (CW) Doppler can be used to estimate the systolic pulmonary arterial pressure (PAPs) using the simplified Bernoulli equation. We evaluated a new technique of contrast-enhanced CW Doppler for calculating PAPs in patients with trivial TR. Forty-one patients without visible TR detected by color Doppler, pulsed Doppler or CW Doppler were evaluated. Age ranged from 19 to 73 (55 +/- 12) years old. Tricuspid flow signals were recorded on CW Doppler after intravenous administration of indocyanin green (ICG) or Albunex. PAPs was calculated as; PAPs = 4 x VTR2 + 10 mmHg, where VTR is the peak velocity of TR. PAPs calculated using contrast-enhanced CW Doppler was compared with PAPs measured by the following cardiac catheterization. 1) TR signals were recorded using the contrast-enhanced CW Doppler technique in 39 of 41 patients (95%) after intravenous administration of contrast agents. 2) The error of estimate of PAPs using the contrast-enhanced CW Doppler technique was -2.4 +/- 7.5 mmHg, and the percent error was -10.7 +/- 32.4% in all patients. In 20 of 39 patients (51%), the error of estimate was within +/- 5 mmHg. 3) PAPs was overestimated by 12.2 +/- 6.1 mmHg in patients with good contrast enhancement of TR signals. The contrast-enhanced CW Doppler technique is useful for estimating PAPs noninvasively in patients with trivial TR. It is better to assume the right atrial pressure as 3-5 mmHg, not 10 mmHg, in patients with good enhancement of trivial TR. Physiological TR may be enhanced by contrast agents in these patients.

Adult↗
PubMed1999

Vascular remodeling in hypertensive transgenic mice.

We physiologically and histopathologically analyzed vascular damage due to hypertension and vascular remodeling in hypertensive transgenic mice (Tsukuba hypertensive mice; THM). Pubertal (6-week-old) THM already had hypertension similar to blood pressure in adult THM due to an enhanced renin angiotensin system (RAS). They progressively developed remarkable vascular hypertrophy composed of dedifferentiation of vascular smooth muscle cells (VSMCs) and extracellular matrix accumulation in the thoracic aorta, and VSMC hyperplasia was predominant in the abdominal aorta. THM are therefore a useful animal model for studying vascular remodeling mediated by enhanced RAS.

Aldosterone↗
PubMed1999

Microhardness evaluations of resin-dentin bonding areas by nano-indentation.

The purpose of this experiment was to determine the hardness values of the hybrid layer and its surroundings through the continuous use of a microhardness measuring device. Black's Class V cavities were prepared in nine dog teeth. The cavities were divided into four groups according to the dentin adhesive system applied. The adhesive systems were: "Bond One System", "Liner Bond II sigma System", "One Step System", and "Single Bond System". The treated teeth were observed at seven days post-application. Specimens were cross-sectioned perpendicularly or horizontally to the resin-dentin interface and embedded in epoxy resin. Their surfaces were polished. The microhardness of the resin-dentin bonding area was measured with a nano-indentation tester. The hardness values at a point of 10 microns distant from the interface in the direction of the dentin differed between systems. It appeared that this was influenced by the presence of the decalcified dentin not impregnated by resin, differences in the chemistry forming the hybrid layer, and the composition of the bonding resin. The hardness of the dentin-bonding interface and its surroundings was determined, and these areas were observed using SEM. Three layers were confirmed the healthy dentin layer, the composite resin layer, and the hybrid layer, (in which decalcified dentin impregnated by resin and that not impregnated by resin are considered to be mix). In the hybrid layer, no impression was found by SEM although the hardness in the bonding interface was significantly different. These layers appear to be more elastic and softer than the healthy dentin.

Animals↗
PubMed1999

Differential diagnosis between tumor-forming pancreatitis and pancreatic cancer by percutaneous transhepatic portography and selective direct pancreatic venography.

In 32 patients with tumor-forming pancreatitis and 109 patients with pancreatic cancer, the usefulness of percutaneous transhepatic portography (PTP) and selective pancreatic venography (SPV) for differential diagnosis of the two diseases was evaluated. The PTP images were type I in 53.1%, type II in 21.9%, type III in 12.5%, and type IV in 12.5% of the patients with tumor-forming pancreatitis and type I in 20.2%, type II in 23.9%, type III in 37.6%, and type IV in 18.3% of the patients with pancreatic cancer. Advanced images (type III or type IV) were observed in more than half the patients with pancreatic cancer. Mild images classified as type II were observed slightly more frequently in the patients with pancreatic cancer, but the differential diagnosis of the two diseases was difficult in patients showing type II PTP images. SPV findings were primarily hypervascularization (78.1%) and vasodilation (68.8%) in the patients with tumor-forming pancreatitis. Although encasement (smooth encasement) was noted in 31.3%, obstruction was found in only 3.1%. In the patients with pancreatic cancer, obstruction was observed in 85.3%, and encasement (irregular encasement) was noted in 78.9%. However, hypervascularization or vasodilatation was infrequent, and the tumor was characteristically imaged as a hypovascular area. PTP and SPV were considered to be useful for the differential diagnosis of tumor-forming pancreatitis and pancreatic cancer.

Diagnosis, Differential↗
PubMed1999

Deletion mapping and X inactivation analysis of a non-specific mental retardation gene at Xp21.3-Xp22.11.

We report on deletion mapping and X inactivation analysis of a gene for X linked non-specific mental retardation (MRX) at Xp21.3-Xp22.11, on the basis of molecular studies in two families with Xp microdeletions involving the DAX-1 gene. In family A, mental retardation (MR) was profound in the older brother with an episode of adrenal crisis, severe in the younger brother with no episode of adrenal crisis, and mild to moderate in the sister and the mother with no signs of adrenal hypoplasia. In family B, MR was absent in the male patient with adrenal hypoplasia. Polymerase chain reaction for 16 loci in the middle of Xp showed that the brothers of family A had a small Xp deletion between DXS7182 and DXS1022, and that the patient of family B had a tiny Xp deletion between DXS319 and DXS1022. Microsatellite analysis for tetranucleotide repeats in the promoter region of the DAX-1 gene and Southern blotting for DAX-1 and DXS28 showed that the sister and the mother of family A were heterozygous for the interstitial deletion. X inactivation analysis for the methylation status of the AR gene and the HPRT gene indicated that the normal X and the deleted X chromosome underwent random X inactivation in both the sister and the mother. The results imply that an MRX gene subject to X inactivation is present in a roughly 4 Mb region between DXS7182 and DAX-1, and that reduced expression of the normal MRX gene caused by random X inactivation results in MR in carrier females.

Child↗
PubMed1999

[Valve replacement for congenital mitral stenosis associated with double orifice mitral valve: a case report and a review of Japanese literatures].

A 3-year-old girl with congenital mitral stenosis (CMS) associated with double mitral orifice valve (DOMV) underwent successfully mitral valve replacement (MVR). DOMV is a rare form of congenital cardiovascular anomaly. To our knowledge, our patient is the first infant case of CMS due to DOMV in Japan. We present an infant case of CMS associated with DOMV who needed MVR, and discuss our patient with a review of Japanese literatures.

Cardiac Surgical Procedures↗
PubMed1999

[Trans-sternal bilateral thoracotomy for bilateral metastatic lung tumors].

Trans-sternal bilateral thoracotomy has been performed in 4 patients with bilateral metastatic lung tumors. The primary lesion was rectum in one case and the colon in three cases. Two patients were male and 2 were female. Their ages ranged from 63 to 78 years old. An inframammary incision was made with the patient in the supine position, and the chest was entered via the 4th or 5th intercostal space. This procedure provided excellent exposure of the entire mediastinum. Postoperative pain was comparatively severe in the early postoperative period, but was controlled by administering an epidural block. This procedure allows good exposure of the entire thoracic space through a single operative field. We conclude that trans-sternal bilateral thoracotomy is an excellent approach in the patient with bilateral metastatic lung tumors.

Aged↗
PubMed1998

Differential regulation of microglial activation by propentofylline via cAMP signaling.

A pathological microglial activation is believed to contribute to progressive neuronal damage in neurodegenerative diseases by the release of potentially toxic agents and by triggering reactive astrocytic changes. Using cultured microglia from neonatal rat brains, we investigated the mode of propentofylline action in strengthening cAMP-dependent intracellular signaling. We compared this action with the effects of dibutyryl-cAMP, a cell-permeable cAMP analog. Propentofylline inhibited lipopolysaccharide (LPS)-induced release of both tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta in a dose-dependent manner within the therapeutic low micromolar range. However, LPS-induced release of IL-6 and NO were not affected by propentofylline. All these differential effects of propentofylline on LPS-induced microglial release were mimicked by the addition of dibutyryl-cAMP. Microglial proliferation and phorbol myristate acetate (PMA)-induced O2- release were also dose-dependently inhibited by propentofylline as well as dibutyryl-cAMP. These results suggest that propentofylline, probably via reinforcement of cAMP intracellular signaling, alters the profile of the newly adopted immune properties in a way that it inhibits potentially neurotoxic functions while maintaining beneficial functions. This differential regulation of microglial activation may explain the neuroprotective mechanism exerted by propentofylline.

Animals↗
PubMed1998

Spatiotemporal measurement of free radical elimination in the abdomen using an in vivo ESR-CT imaging system.

Electron spin resonance (ESR) imaging can visualize the distribution of free radicals in living systems according to their concentrations. However, the application of ESR imaging to living animals has not been well established. Using a rapid field scan L-band ESR imaging system, we have successfully obtained two-dimensional ESR projection (xz-plane projection) and three-dimensional ESR-CT (trans-axial section along the y-axis) images of the abdomen of living mice after an injection of 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (carbamoyl-PROXYL) into the tail vein. The in vivo two-dimensional ESR projection imaging clearly visualized the carbamoyl-PROXYL distribution and the rapid decay process in the abdomen. Because among the viscera, the liver is most abundantly associated with a blood volume, the outline of the image can be composed mainly of this organ. We therefore attempted to find whether there will be a difference in spatiotemporal dynamics of carbamoyl-PROXYL in the abdomens between the control and the mice with liver damage by two-dimensional ESR projection. In the control mice, carbamoyl-PROXYL was almost completely eliminated from the abdomen within 5 minutes after administration. On the other hand, in mice with carbon tetrachloride-damaged livers, the decay of carbamoyl-PROXYL was markedly prolonged. Even at 5 min after administration, carbamoyl-PROXYL remained clearly visible in the abdomen. In vivo three-dimensional ESR-CT imaging showed an even distribution of carbamoyl-PROXYL throughout the whole liver, which corresponded well with the images of trans-axial sections of the murine abdomen. We have succeeded in displaying two-dimensional ESR projection and three-dimensional ESR-CT images of carbamoyl-PROXYL distribution and clearance in the abdomen of a living animal. The ESR-CT imaging technique is considered to be a powerful new tool for noninvasive investigations of the in vivo spatiotemporal dynamics of free radical distribution and elimination in the organs.

Abdomen↗
PubMed1998

Enhancement of nitroxide-reducing activity in rats after chronic administration of vitamin E, vitamin C, and idebenone examined by an in vivo electron spin resonance technique.

Rats were given vitamin E (Vit-E), idebenone (ID), or vitamin C (Vit-C) in their food for 2 or 4 weeks. After feeding, the ability of rats to reduce 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (Tempol) in terms of the half-life of Tempol was examined as a specific marker. Tempol was repeatedly injected intravenously, and its half-life was serially evaluated by an in vivo electron spin resonance (ESR) technique. The radical-reducing ability in rats was enhanced differently by Vit-E, ID, and Vit-C, i.e., slow onset of the ability after Vit-E and ID (lipid-soluble antioxidants) and fast onset after Vit-C (a water-soluble antioxidant).

Animals↗
PubMed1998

The mechanism of in vivo bacteriostasis of bovine lactoferrin.

Recently we have reported that orally administered bovine Lf(bLf) exerts bacteriostatic effects against bacterial overgrowth in the intestine of specific-pathogen-free (SPF) mice fed milk. In this animal model, the in vivo bacteriostatic effect of bLf against the proliferation of intestinal Enterobacteriaceae, the bacteria most sensitive to bLf, was independent of the iron-chelating ability of bLf. In addition various proteolytic hydrolysates of bLf (with differing antibacterial activities in vitro) showed the same bacteriostatic effect as undigested bLf. These results suggest that the mechanism of in vivo bacteriostasis of Lf differs from the in vitro mechanism reported. In SPF mice fed milk differing in concentrations of lactose, glucose and galactose, the proliferation of intestinal Enterobacteriaceae was dependent on the carbohydrate concentration in the diet. The addition of 2% bLf to the diets significantly suppressed this carbohydrate-dependent proliferation of bacteria except in the case of diets containing excess carbohydrate. In germ-free mice fed sterile milk, the addition of 2% bLf to milk resulted in a significant decrease in concentrations of lactose, glucose and galactose in the cecal contents. In an in vitro assay system using everted sacs of the small intestine of SPF mice, both bLf and its pepsin hydrolysate apparently stimulated glucose absorption. Based on these findings, we propose that the in vivo mechanism of action of ingested bLf involves the stimulation of carbohydrate absorption resulting in a bacteriostatic effect against Enterobacteriaceae in the intestine of mice fed milk.

Animals↗
PubMed1998

Pathological immuno-reactions of glial cells in Alzheimer's disease and possible sites of interference.

A significant role of a pathological glial cell activation in the pathogenesis of Alzheimer's disease is supported by the growing evidence that inflammatory proteins, which are produced by reactive astrocytes, promote the transformation of diffuse beta-amyloid deposits into the filamentous, neurotoxic form. A number of vicious circles, driven by the release of TNF-a and free oxygen radicals from microglial cells, may cause an upregulated microglial activation and their production of interleukin-1 which triggers, secondarily, the crucial activation of astrocytes. Reactive functional changes of glial cells seem to be controlled by an altered balance of the second messengers Ca2+ and cAMP and can be counterregulated by the endogenous cell modulator adenosine which strengthens the cAMP-dependent signalling chain. A further reinforcement of the homeostatic adenosine effects on glial cells by pharmaca, such as propentofylline, may add to neuroprotection in Alzheimer's disease.

Adenosine↗
PubMed1998

[Acute aortic dissection after aortic valve replacement].

A 53-year-old male who had been performed aortic valve replacement 15 weeks before was admitted to our hospital because of severe chest pain. Cjest computerized tomography showed dissection of aorta from ascending to descendig aorta and hemorrhage around ascending aorta. An emergency operation was performed under hypothermic circulatory arrest with a selective cerebral perfusion. An entry of dissection was found at posterior wall where was 3 cm upper from an artificial valve. Total arch replacement was successfully performed. There is a few cases of aortic dissection after aortic valve replacement, but careful peri and post operative care is necessary after aortic valve replacement.

Acute Disease↗