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Biomedical subjects

K Aoki

Publications and source records attributed to K Aoki.

At least 1,135 records · Page 63Linked to original sources
PubMedDate not supplied

In vivo and in vitro effects of phenytoin (PHT) on ATPases and [14C]-PHT binding in synaptosomes and mitochondria from rat cerebral cortex.

The effect of phenytoin (PHT) on Na(+)-K(+)-ATPase and Mg(2+)-ATPase activities and on [14C]-PHT binding in vitro to synaptosomal and mitochondrial subcellular fractions from rat cerebral cortex was studied after chronic PHT treatment. Synaptosomal and mitochondrial fractions were characterized with plasma membrane and mitochondrial enzymatic markers. Synaptosomal Na(+)-K(+)-ATPase was not affected in vitro by PHT 1-200 microM or by chronic treatment with 2-50 mg/kg/day of the unlabeled drug for 8 days. Mitochondrial Mg(2+)-ATPase was significantly stimulated by PHT after chronic treatment with 5 mg/kg/day for 8 days; reaching maximal effect (76%), at 10-25 mg/kg. PHT had no effect on mitochondrial Mg(2+)-ATPase when added in vitro. [14C]-PHT binding in vitro to the subcellular fractions was determined by dialysis to assess in vivo binding of the unlabeled PHT during chronic treatment. Indeed, [14C]-PHT bound to synaptosomes was significantly reduced by chronic PHT treatment from 218 +/- 10 to 119 +/- 11 pmol/mg protein after 1 week of treatment; a similar effect was obtained after 2-3 weeks with 10 mg/kg/day. Mitochondrial fraction bound 117 +/- 10 pmol/mg protein labeled PHT. Chronic treatment with unlabeled PHT also reduced the amount of [14C]-PHT bound to 19.9 +/- 2.2 pmol/mg protein. These results show slow reversible PHT in vivo binding to synaptosomes and mitochondrias from rat cerebral cortex, supporting the idea that the modulatory action of PHT on Na+ and Ca2+ permeabilities are mediated through these slow reversible binding proteins. The data also suggest a possible role of intrasynaptosomal mitochondria in [Ca2+]i buffering.

Animals↗
PubMedDate not supplied

Measurement of diagnostic x-ray spectra using a silicon photodiode.

Diagnostic x-ray spectra (66-103 kV, 1-2 mA) were measured without pinhole collimator or liquid nitrogen cooling by using a silicon p-i-n photodiode. An x-ray count rate was low (approximately 400 photons/s) at distances of 2-3 m away from an x-ray target, because the i layer of the photodiode was very small (1.5 mm2 in area and 75 microns in thickness). The junction reverse current of the photodiode was 50-70 pA at room temperature and energy resolution for 59.5-keV gamma rays was 2.0 keV (full width at half-maximum), which was limited by the electric noise of a preamplifier. Measured spectra were corrected for detector distortion. The corrected spectra were similar to those determined with a Ge detector. The i-layer thickness of the photodiode was an important parameter for the correction. In particular, when the thickness was thin, the fraction of photoelectron escape became large; this fraction was estimated analytically for various i-layer thicknesses. The angular dependence of the full-energy peak efficiency was measured; for the photons whose energies were above 17.8 keV the angular dependence was isotropic except for angles greater than 60 degrees off the photodiode axis. This method is therefore applicable to the measurement of scattered x rays.

Radiography↗
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A phase II study of cisplatin in patients with biliary tract carcinoma.

A phase II study of cisplatin was performed in 13 previously untreated patients with unresectable biliary tract carcinoma. The drug was given intravenously at a dose of 80 mg/m2/day once every 4 weeks. Of 13 patients evaluated, 1 showed partial response lasting 3 months, while no patients showed complete response. Of 9 patients, whose serum level of carcinoembryonic antigen (CEA) was high (> or = 10 ng/ml) before treatment, 4 showed > or = 50% reduction in serum CEA level after treatment. The current study indicates that cisplatin does not have significant antitumor activity against biliary tract carcinoma.

Adolescent↗
PubMedDate not supplied

Contractile protein isoforms of single and cultured smooth muscle cells from guinea pig ileum.

Single smooth muscle cells isolated from guinea pig ileum using collagenase and papain produce contractile response to muscarinic agents, while the cultured cells do not. Using fluo-3/AM and a confocal laser scanning fluorescence microscope, it was observed that carbachol, a muscarinic agent, caused an increase in the intracellular Ca2+ of both single and cultured cells. SDS-PAGE and Western Blot analyses revealed the expression of myosin heavy chain isoforms of SM1 (204 kDa) and SM2 (200 kDa) in single smooth muscle cells, and non muscle isoform (196 kDa) of myosin heavy chain only in the cultured cells. With respect to actin isoforms, alpha-actin was predominant in single cells and beta-actin was major in the cultured cells. Two types of tropomyosin monomer, 39 kDa and 41 kDa, were detected in single cells, while the 41 kDa monomer was lost in cultured cells. These differences in contractile protein profiles between single and cultured cells were collaborated with the observation of cells using immunofluorescence microscope with responsible antibodies to isoforms of myosin heavy chain, actin and tropomyosin. These results suggest that the loss of contractility in cultured smooth muscle cells is profoundly related to changes in contractile protein profiles from smooth muscle type to non muscle type.

Actins↗
PubMedDate not supplied

Prognosis of female patients with pulmonary tuberculosis.

To study the risk of death and causes of death among female patients with tuberculosis (TB), a total of 1,083 female patients who diagnosed as having active pulmonary TB and newly registered into the Nagoya TB registry between 1979-1981 were followed up till the end of 1983. During follow-up period 138 deaths (12.7%) were observed, a significantly higher rate than expected from the general population. Observed deaths (O) from all types of cancer (O/E ratio = 2.5), lung (6.4) and colorectal cancers (5.0), were significantly higher than that which was expected (E). The number of deaths from TB was naturally high (O/E ratio = 40.0, p less than 0.001). Malignant lymphoma and multiple myeloma also showed high relative risk. The smoking rate among the patients was 14%, about the same as with the general population. Excessive high rates of death from lung cancer were observed both among smoking and non-smoking cancer patients. Non-smokers showed a high proportion (60%) of adenocarcinoma. The proportion of the use of antituberculous drugs during the past five years was not different between the lung cancer group and the non-lung cancer group. Patients who died from cirrhosis of the liver showed more frequent use of antituberculous drugs than the others. Factors causing excess incidence of colorectal cancer remain unknown. It was suggested that some immunologic disorders in TB patients may play some role in the development of cancer.

Adult↗
PubMedDate not supplied

Infective endocarditis of the tricuspid valve in a non-drug user.

A case of infective endocarditis of the tricuspid valve is described in a young female patient with no history of intravenous drug abuse. The patient suffered from symptoms of septic emboli of the lung and right heart failure. She was ultimately treated by tricuspid valve replacement. There was no recurrence of symptoms following surgery.

Adult↗
PubMedDate not supplied

Effect of middle ear infection on pneumatization and growth of the mastoid process. An experimental study in pigs.

The intention of this experiment was to investigate whether anatomical variations of the temporal bone such as low middle fossa dura, anterior position of the sigmoid sinus or small mastoid process, which are often seen at surgery in cholesteatoma patients, are caused by inflammation in early childhood. In 7 pigs, 1.5 ml paraffin liquid were instilled into the left tympanic cavity 2 or 7 days after birth in order to produce inflammation of the middle ear and tubal dysfunction. After six and a half months the length and area of the mastoid process were significantly smaller on the left instilled side than on the right, normal side. In all cases there was remarkable hypocellularity and increased thickness of the cortical bone strongly supporting the environmental theory of pneumatization that inflammation suppresses the pneumatization process and growth of the mastoid process.

Animals↗
PubMedDate not supplied

Evaluation of serological tests for screening of chlamydial eye diseases.

Trachoma is recognized as one of most important origins of blindness in developing countries and inclusion conjunctivitis is associated with STD in developed countries. We evaluated the diagnostic value of serological tests for the screening of eye diseases associated with Chlamydia trachomatis infection. We determined serum IgG, IgA and IgM antibodies to C. trachomatis from 53 Japanese patients with active inflammatory trachoma (aged more than 60 years) and from 107 adult patients (aged 20 to 50 years) with acute inclusion conjunctivitis by ELISA test kit. We detected serum IgG antibodies from 22 out of 53 (42.5%) patients with trachoma and from 40 out of 107 (37.4%) patients with acute inclusion conjunctivitis. We also detected serum IgM antibodies from 7 out of 53 (13.2%) patients with trachoma and from 35 out of 107 (32.7%) patients with acute inclusion conjunctivitis. The prevalence of serum IgM antibodies to C. trachomatis in patients with acute inclusion conjunctivitis was significantly higher than that in patients with active trachoma (p < 0.05). Serological tests are also thought to be useful for screening of chlamydial eye diseases.

Adult↗
PubMedDate not supplied

A case of living-related partial liver transplantation using the right gastroepiploic artery for hepatic artery reconstruction.

A 13-year-old boy with liver cirrhosis underwent living-related partial liver transplantation with a left lobe from his mother. A standard hepatic artery reconstruction using the recipient right hepatic artery was anticipated. Unfortunately, the recipient hepatic artery was found to be severely arteriosclerotic and was unsuitable for reconstruction. Instead, the right gastroepiploic artery, measuring 2.0 mm in diameter, was mobilized and was anastomosed to the left hepatic artery of the graft in an end-to-end fashion. Arterial blood flow was satisfactory. The patient's postoperative course was uneventful, and he was transferred to a floor bed on the 5th postoperative day.

Adolescent↗
PubMedDate not supplied

A simple novel method of biliary drainage: gallbladder serosal wrapping after open choledochotomy.

In this study, we developed a new, simple technique for biliary drainage after open choledochotomy of choledocholithiasis. After the absence of intraductal stones was established by operative cholangiography and cholangioscopy, preserved gallbladder serosal wrapping was performed by inclosing a polyethylene tube (C-tube), which was inserted from the cystic duct to optimal portion of choledochus, within the gallbladder bed, with continuous suture of the preserved serosa of the gallbladder using 4-0 absorbable thread. This method was used in the cases of 8 patients. There was neither bile leakage nor residual bile duct stones. The C-tube could be removed after 7 days following surgery. The average hospital stay was 12.3 +/- 6.6 days. We propose that this procedure would be very simple and useful, and it would significantly shorten hospital stays after open choledochotomy of choledocholithiasis.

Drainage↗
PubMedDate not supplied

Flow volume in the common carotid artery detected by color duplex sonography: an approach to the normal value and predictability of cerebral blood flow.

PURPOSE: To determine normal common carotid artery (CCA) flow volume, its relationship with age, and the predictability of cerebral blood flow (CBF) by color duplex sonography. SUBJECTS AND METHODS: Forty-five healthy subjects (18 men, 27 women, 23-86 years old) and 13 patients (3 men, 10 women, 51-88 years old) without neurological disease underwent color duplex sonography. All 13 patients also underwent xenon CT. CCA flow volume in the healthy subjects was measured to determine normal values. This volume was divided by mean brain weight to estimate CBF, which was correlated with CBF measured by xenon CT in regions of ipsilateral internal carotid arteries (ICA). RESULTS: In healthy subjects, CCA flow volume ranged from 155.0-458.8 ml/min (mean+/-SD: 267.77+/-59.91), corresponding to an estimated CBF of 12.43-32.84 ml/min/100 g brain weight (mean+/-SD: 20.63+/-4.22). No relationship was found between flow volume and age. A good correlation was found between estimated CBF and CBF measured by xenon CT in regions of both ICAs (gamma=0.713, p=0.0062 on the left; gamma=0.686, p=0.0096 on the right). CONCLUSION: By using color duplex sonography, we established a set of normal CCA flow volumes, which do not decline with age. Estimated CBF derived from flow volume can predict actual CBF.

Adult↗
PubMedDate not supplied

Long-term follow-up of congenital subluxation of the hip.

SUMMARY: This is a retrospective study of long-term radiographic results for congenital subluxation of the hip (CSH) after closed reduction at the authors' hospital from 1963 to 1980. The age at final follow-up ranged from 14.0 to 33.9 years (average 19.1). The diagnosis of CSH was determined radiographically using Ishida criteria. The center-edge angle (CE angle) and the Sharp angle were measured serially, and the final results were evaluated using Severin classification, and evaluation of avascular necrosis used the classification of Kalamchi and MacEwen. Sixty-nine (26.3%) of 262 hips with CSH were rated as Severin group III or IV. Avascular necrosis was found in 12 hips (4.6%). The CE angle of unaffected hips had strong correlation with that of affected hips. These late results were not satisfactory and indicate that patients with CSH should be followed up at least until skeletal maturity, as is done with complete hip dislocation.

Aftercare↗
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Modification of apoptosis-inducing activity of gallic acid by saliva.

Gallic acid, a structural unit of tannin, induced apoptotic cell death, characterized by nuclear condensation and caspase activation in human oral tumor cell lines (HSC-2, HSG). Agarose gel electrophoresis demonstrated that gallic acid produced large DNA fragments in these cells, as well as in T-cell leukemia (MOLT-4) and erythroleukemia (K-562) cells, whereas it induced internucleosomal DNA fragmentation in human myelogenous leukemic cell lines (HL-60, ML-1, U-937, THP-1). This indicates that induction of internucleosomal DNA fragmentation or production of large DNA fragments depends on both target cells and inducers. Addition of total saliva dose-dependently reduced the cytotoxicity induction by gallic acid. These data suggested that the biological action of gallic acid might be modified by physiological fluids.

Antioxidants↗
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Firefly luciferase gene transmission and expression in transgenic medaka (Oryzias latipes).

Plasmids containing the luciferase gene from the firefly (Photinus pyralis) fused to the Chinese hamster metallothioneine I promoter (ChMTI) were microinjected into the pronuclei of medaka (Oryzias latipes) eggs, which were then artificially inseminated. Evidence of integration into the genome was gained from observation of germ-line transmission in a mendelian fashion from the F1 to the F2 generation. However, gene expression (light emission) could not be demonstrated in the established transgenic line. In a separate program, transient expression of gene constructs containing the luciferase gene fused to various promoters was compared in medaka embryos. Plasmids were microinjected into pronuclei, and homogenates from 3-day-old embryos were measured for light emission using a luminometer. Among the various promoters tested (SV40, RSV-LTR, ChMTI, HSP70, and mouse albumin), the highest levels of luciferase gene expression were observed in gene constructs containing ChMTI and HSP70 gene promoters. Expression in these two constructs was significantly increased following administration of ZnSO4 or heat treatment, respectively. Plasmids were also introduced into goldfish fibroblast-like cells in vitro, in which enzymatically active luciferase was transiently expressed. Assaying for expression of luciferase provided a rapid and sensitive method for monitoring promoter activity. The potential usefulness of this fish species for cancer research is discussed based on accumulated information from carcinogenesis studies.

Animals↗
PubMedDate not supplied

Deacetylation of cinobufagin by rat liver.

The enzyme system mediating the deacetylation of cinobufagin (CB) at the 16-position to give deacetylCB was characterized in the rat. Tissue distribution studies showed that the highest activity of CB deacetylation was mainly localized in the liver microsomal fraction. Some activity was also detected in the serum and intestine. Kinetic studies of the enzymatic reaction carried out by microsomes demonstrated that the formation of deacetyl-CB increased linearly with time up to 60 min and with protein content up to 10 mg. Apparent Km and Vmax values calculated from Lineweaver-Burk plots were 2.7 x 10(-4) M and 4.17 nmol/mg of protein/min, respectively. Low concentrations of several metal salts (AgNO3, MgCl2, CoSO4, and CuCl2) did not affect CB deacetylase activity. Microsomal CB deacetylation was inhibited by the organophosphorus compounds cyanox and fenitrothion at 1.0 x 10(-6) M. Eserine sulfate, disulfiram, rifampicin, and phenacetin at 1.0 x 10(-4) M also decreased CB deacetylase activity. Aspirin, sodium fluoride, and EDTA at 1.0 x 10(-3) M did not inhibit the deacetylation. In vivo treatment of rats with phenobarbital resulted in a 2-fold increase in microsomal CB deacetylase activity. All of these results suggest that the enzyme responsible for CB deacetylation is somewhat different from the other characterized esterases.

Acetylation↗
PubMedDate not supplied

Metabolism of cinobufagin in rat liver microsomes. Identification of epimerized and deacetylated metabolites by liquid chromatography/mass spectrometry.

The metabolism of cinobufagin (CB) in rat liver microsomes was studied. By comparison of retention times and fragmentation patterns obtained by thermospray LC/MS with those of authentic standards, four metabolites of CB were also identified, in addition to deacetylCB (M1) and 3-epideacetylCB (M2), which have been reported previously. The additional four metabolites were identified to be 3-epiCB (M4), 3-ketoCB (M5), 3-keto-16 beta-OH-deacetylCB (M3), and 3-keto-16 alpha-OH-deacetylCB (M6). The primary metabolic products of CB were M1 and M2, with a small amount of M4 and trace amounts of M3, M5, and M6. These results indicate that major metabolic routes of CB were deacetylation at the 16-position and epimerization at the 3-position via the 3-keto intermediate.

Acylation↗