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Biomedical subjects

K Fukui

Publications and source records attributed to K Fukui.

At least 181 records · Page 10Linked to original sources
PubMed1996

Uptake of radioactive octanoate in astrocytoma cells: basic studies for application of [11C]octanoate as a PET tracer.

Fatty acids are taken up and metabolized in the brain. In vitro uptake experiments on astrocytoma cells were carried out to assess the potential use of [1-11C]octanoate as a positron emission tomography (PET) tracer for astroglial functions. Uptake of [1-14C]octanoate increased in a time-dependent fashion until 60 min after application. The uptake of [1-11C]octanoate showed similar results to that of [1-14C]octanoate until 10 min. As for medium pH, [1-14C]octanoate uptake increased gradually with the decrease in pH. We also examined the effects of glutamate, glucose deprivation and hypoxia on the uptake of octanoate and found that these conditions did not bring about any change in the extent of [1-14C]octanoate uptake. These results show that the octanoate uptake was not influenced by any of several pathological conditions. When the number of astrocytes increases in the area of hypoglycemia or hypoxia near a brain lesion, the amount of octanoate uptake also increases, so this indicates the possibility that 11C-octanoate will detect a brain lesion.

Astrocytoma↗
PubMed1996

Different signalling pathways involved in transforming growth factor-beta 1-induced morphological change and type IV collagen synthesis in simian virus-40-immortalized normal human salivary gland duct and myoepithelial cell clones.

To understand the specific cell type responsible for the synthesis of basement membrane components of the salivary gland, the effects of transforming growth factor (TGF)-beta 1 on morphological change, cellular proliferation and collagen synthesis were examined in these immortalized duct and myoepithelial cell clones, and the expression forms of their TGF-beta receptors analysed. When TGF-beta 1 was added to the cell clones in vitro, it induced a morphological alteration, with flattening in myoepithelial but not in duct cells. Although the growth of Mv1Lu mink lung epithelial cells was almost completely inhibited by TGF-beta 1, the duct and myoepithelial cells were partially resistant to such inhibition. By immunoblot analysis of immunoprecipitates, p53 was found bound to the simian virus-40 large T antigen, suggesting a functional loss of p53 in regulation of cell-cycle arrest. In the cloned myoepithelial cells but not the duct cells, TGF-beta 1 stimulated the production of type IV collagen. To attempt to understand the distinct responsiveness of cell clones to TGF-beta 1, the expression forms of TGF-beta receptors were examined by affinity cross-linking. Although the intensities of the cross-linked bands of the TGF-beta type II and type III receptors, particularly the type II, were weaker in the duct than the myoepithelial cell clones, the expression of the type II receptor mRNA was consistently detected in both clones. Accordingly, the reduction of TGF-beta 1 binding may have occurred at the post-transcriptional level. These findings imply that the cloned myoepithelial cells but not the cloned duct cells produce type IV collagen in response to TGF-beta 1 through the receptor-mediated signal transduction pathway, which is presumably disrupted in the cloned duct cells.

Animals↗
PubMed1996

Absorption and metabolism of lipids in rats depend on fatty acid isomeric position.

This study determined the effect of dietary (dipalmitoyl) triacylglycerol (TAG) structure on the absorption and metabolism of fat in the presence or absence of cholesterol. Sprague-Dawley male rats weighing approximately 180 g were fed diets containing 10 g/100 g diet 1,3-dipalmitoyl-2-oleoyl-glycerol-rich oil (POP) or 1(3),2-dipalmitoyl-3(1)-oleoyl-glycerol-rich oil (PPO), either with or without cholesterol supplementation (0.5 g/100 g diet), for 2 wk. There were no differences in the growth of rats fed the various diets. The apparent absorption efficiency of dietary fat especially the apparent absorption efficiency of palmitic acid, was significantly lower in the POP groups than in the groups fed the PPO diets. The excretion of cholesterol in feces of rats fed the POP diet with cholesterol was significantly greater than those fed the PPO diet containing cholesterol. The excretion of total bile acids in the rats fed cholesterol was significantly greater than in those fed the diets without cholesterol. Liver cholesterol was significantly greater in rats fed cholesterol and was not affected by the TAG structure. Plasma cholesterol was significantly lower in the POP dietary groups than in the PPO groups. These results suggest that the absorption and metabolism of fat depend on the positional isomer of the fatty acid.

Absorption↗
PubMed1996

Characterization of heterochromatic regions in 'Trovita' orange (Citrus sinensis Osbeck) chromosomes by the fluorescent staining and FISH methods.

CMA/DAPI double staining and FISH methods using rDNA and telomere specific repeated sequences as probes were applied to characterize the large amount of heterochromatin in the telomeric regions of 'Trovita' orange (Citrus sinensis Osbeck) chromosomes. As a result, all the heterochromatic regions were CMA+/DAPI-, and thus were GC rich. Three CMA+/DAPI- heterochromatic regions were positive to the 26S rDNA probe. Telomere arrays consisting of Tm(A)Gn were detected on the extreme ends of each chromosome and most of the CMA+/DAPI- heterochromatic regions were ordered close inside the telomere-specific repeated sequences. The data obtained in this study will be useful for karyotyping, systematics, and molecular analysis of orange chromosomes.

DNA Probes↗
PubMed1996

A fetal intestinal-type alkaline phosphatase produced in Caco-2 cells.

Enzymic, immunological and lectin-binding properties of alkaline phosphatase (AP) produced in Caco-2 cells, a human colon carcinoma cell line, were investigated. The enzyme was very similar to fetal intestinal (meconium) AP in the enzymic and immunological properties, but different from fetal intestinal AP in lectin-binding properties; expression of the galactose moiety was altered in AP of Caco-2 cells, compared to that of fetal intestinal AP. These results indicate that AP of Caco-2 cells can be used in place of fetal intestinal AP when the enzymic properties of an AP of unknown origin are investigated, but cannot be used instead of fetal intestinal AP in the structural study of AP.

Alkaline Phosphatase↗
PubMed1996

Cerebral cysticercosis manifesting as hydrocephalus--case report.

A 70-year-old female presented with gait disturbance and dementia. Cerebrospinal fluid examination revealed mild aseptic meningitis. Magnetic resonance images showed multiple cystic lesions and mural nodules in some of the cysts in the cerebral parenchyma. Metrizamide computed tomography clearly demonstrated multiple intracisternal cysts. Some cysts were surgically excised and a ventriculoperitoneal shunt was implaced. Postoperatively, her gait disturbance and dementia disappeared. Histological examination revealed cysticercosis with viable larva. Ten months after the initial surgery, she presented with right hemiparesis due to enlargement of the remaining cysts in the left frontal lobe. These cysts were removed. Postoperative neurological examination showed slight right hemiparesis. We recommend ventriculoperitoneal shunting for hydrocephalus due to cisternal cysticercosis and praziquantel administration for parenchymal lesions.

Aged↗
PubMed1996

[Basic amino acid, L-arginine aggravates ischemia-reperfusion injury].

Basic amino acid, L-arginine has been known to have several biological actions including nitric oxide production. The real effects caused by L-arginine administration to heart has not been fairly understood in the setting of ischemia-reperfusion process. The effects of L-arginine on recovery of myocardial contractile function and oxidative metabolism were studied in a model of reversible global normothermic ischemic injury using an isolated, buffer-perfused rabbit heart preparation. 1 mM L-arginine or vehicle was infused into hearts for 2 minutes at the onset of 35 minutes of ischemia in L-arg. group or in control group, respectively. Oxygen consumption (MVO2), lactate release into coronary vessels, and cardiac function including developed pressure, +dp/dt, -dp/dt and diastolic pressure-volume relationship (PVR) were measured and high energy phosphates were also evaluated by 31P-NMR spectroscopy. Endothelial function was also evaluated by acetylcholine (Ach) infusion with monitoring of constant perfusion pressure. L-arginine caused a significant increase in the PVR and profund decline in systolic function when compared to control group. MVO2 was significantly impaired to cause a decrease of high energy phosphates (phosphocreatine and ATP). Lactate release into coronary vessels on reperfusion was significantly higher in L-arg group than that in control group, suggesting a promotion of anaerobic glycolysis. Deterioration of endothelial function and smooth muscle function of artery were evidenced by Ach infusion test. Although the mechanisms of injury are speculatory, possible mechanisms of this injury are stimulation of nitric oxide production by L-arginine and cation change, especially calcium accumulation. We concluded that L-arginine was able to cause aggravation of ischemia-reperfusion injury with reduced contractile function and mitochondrial function and increased anaerobic glycolysis after ischemia-reperfusion in an isolated model of reversible ischemic injury.

Animals↗
PubMed1996

[A case of inflammatory pseudotumor of the lung with suppressed immune response in the patient with renal cell carcinoma after nephrectomy and administration of interferon].

A 60-year-old man with renal cell carcinoma was treated of right nephrectomy and high dose administration of Interferon-alpha (IFN) in 1990. Three and half years after operation, he complained of cough and hemoptysis. Chest X-ray showed a abnormal shadow (5.5 x 3.5 cm) in the upper lung field. On chest CT, a tumor mass with small cavity was located at S2, attended with the speculation and pleural indentation. A rough nodule suspected daughter tumor was pointed out near the tumor mass. Laboratory investigation revealed mild leucocytosis, an elevated ESR and C reactive protein. On lymphocyte subset, CD 4/8 ratio was 0.8 and NK cell activity was 11%. Immunosuppressive acid protein (IAP) in serum was 1,137 ng/ml. No organisms or malignant cells could be demonstrated in the biopsy materials or sputum. Right thoracotomy and upper lobectomy was carried out. Postoperative pathological diagnosis was inflammatory pseudotumor. Namely, the lesion was occupied with variable admixture of lymphocytes, plasma cells, histiocytes, phagocytes included hemosiderin, foam cells and whorled fibrosis. Daughter tumor was scar tissue. Now, he is well without recurrence and his immune response is within normal level. Some discussion of the literature was mentioned.

Autoimmune Diseases↗
PubMed1996

[Emergency surgical salvage for a type A early thrombosed aortic dissection complicated cardiac tamponade in a 80-year-old-patient].

A 80-year-old woman underwent emergency operation for a type A early thrombosed aortic dissection associated with cardiac tamponade. Her preoperative chest CT (not enhanced) showed high density area in the false lumen that indicated early thrombosis and the projection of true lumen at antero-left-lateral portion of ascending aorta that means "ulcer-like projection" called on aortogram. After the relief of the cardiac tamponade by pericardiocenthesis, we emergently performed the graft replacement of the ascending aorta under the extracorporeal circulation combined with selective cerebral perfusion. Her postoperative course was uneventful and satisfactory.

Acute Disease↗
PubMed1996

[Inappropriate preservation of myocardium by topical cooling with iced slush].

Topical cooling with iced slush has been applied as a conventional myocardial preservation in open heart surgery. However, there might be several disadvantages due to topical cooling with iced slush which melted to be liquid, because of membrane integrity decreased during ischemia. To understand more detailed mechanism of deterioration for myocardium by immersion in some liquid during ischemia, we subjected isolated crystalloid perfused rabbit hearts to a 30 minute of ischemia with immersion in Krebs-Henseleit (K-H) solution (I), K-H+hexamethlyamiloride which was Na+/H+ channel blocker (II) and histidine containing cardioplegia (HBS) designed to accelerate anaerobic glycolysis by a proton buffering (III), followed by a 30 minute of reperfusion. These groups were compared to the hearts hanging in air during ischemia (control). Phosphocreatine (PCr), ATP and intracellular pH were measured by 31 PNMR in group I, II, III. Developed pressure (Dev P) and diastolic pressure (EDP) with a intracavitary balloon were also evaluated with monitoring of 2 mmHg diastolic contracture during ischemia. Dev P declined to 46%, 54% of preischemic value in group I and group II, respectively, although % recovery of control heart was 74% after ischemia-reperfusion process. Diastolic function was severely deteriorated in group I and II, as compared to control heart. ATP and intracellular pH showed a similar decline as PCr in group I and II which was not seen in group III during ischemia. HBS prevented the deterioration of PCr, ATP and intracellular pH during ischemia along with excellent recovery of myocardial function. We therefore conclude that 1) significant deterioration of myocardium occurs with ischemia if the heart preserved in Krebs-Heseleit solution and the mechanism of injury by immersion in liquid on the heart appears to be due to proton accumulation caused by intracellular acidification and loss of high energy phosphate.

Animals↗
PubMed1996

[Usefulness of the preoperative MRI for diagnosis and operative method in a case of cor triatriatum].

A case was 6-year-old female diagnosed as the cor triatriatum. The magnetic resonance imaging synchronized at R wave on the electrocardiogram was performed in order to see the abnormal septum in the left atrium. In the horizontal view, the abnormal septum that divides the left atrium into the accessory left atrial chamber and the true left atrium, was well visualized. This septum lied on the vertical portion. Operation was carried out with the approach through the accessory chamber and the fibromuscular membrane were excised. Preoperative imaging of the MRI was useful and helpful for us to reach to a decision of the surgical approach in this patient.

Cardiac Surgical Procedures↗
PubMed1996

[Three cases of acute subdural hematoma in abused children].

We encountered 3 cases of battered children with acute subdural hematoma. In this report, we discuss the difficulties in treating this condition surgically, and we emphasize the importance of early diagnosis and treatment of abused children and their parents. Case 1: A girl, aged 2 months, was brought in by her mother, because the child had become drowsy. The mother stated that the child had been battered by her father. Physical examination revealed tense anterior fontanelle, bruises on her face, consciousness disturbance and retinal bleeding. Marked anemia was revealed on laboratory studies. A computed tomographic (CT) scan demonstrated an interhemispheric subdural hematoma in the parietooccipital region. She was treated conservatively for 2 months. Follow-up CT revealed a bilateral chronic subdural hematoma. Burr hole irrigation and drainage on both sides brought about complete disappearance of these lesions. Case 2: A girl, aged 1 year and 9 months, was brought in by her parents. According to her mother's allegation, the child fell down from the top of an indoor slide and became comatose. Physical examination revealed severe malnutrition, loss of consciousness, dilated pupils and negative light reflex. Numerous areas of subcutaneous bleeding and skin erosions were seen on her back and abdomen. Marked anemia was revealed on laboratory studies. CT scan demonstrated a left acute subdural hematoma and massive brain swelling. Despite an emergency craniotomy, the child died 5 days later. Case 3: A 4-year-old boy was admitted in a comatose state. According to his mother's allegation, he was thrown to the floor from a 1.5m height and struck against a wall by his father. Physical examination revealed severe malnutrition, consciousness loss, dilated pupils and negative light reflex. Many scratches and bruises were seen over his whole body, especially on his back. Marked anemia was revealed on laboratory studies. A CT scan demonstrated a left acute subdural hematoma and massive brain swelling. Three days later, he died despite emergency craniotomy. The incidence of battered children is increasing in Japan, and these cases sometimes involve severe head injuries, such as subdural hematoma. In these cases, successful surgical treatment is difficult after admission to the neurosurgical institute. This may result from late admission as well as marked anemia and malnutrition. Therefore, we conclude that early diagnosis of child abuse and treatment of the abused child and psychological treatment for their parents are very important.

Acute Disease↗
PubMed1995

Effect of chronic toluene exposure on tyrosine hydroxylase-positive nerve elements in the rat forebrain: an immunohistochemical study combined with semiquantitative morphometric analysis.

The effects of chronic toluene exposure [3000 p.p.m. for 4 h (09:00-11:00, 13:00-15:00)] every day for 3 weeks on immunoreactivity for tyrosine hydroxylase (TH), the rate limiting enzyme of catecholamine synthesis, in the rat forebrain were studied. In toluene-exposed rats, increases in both number and intensity of TH-immunoreactive fibres and terminals were observed in most parts of the forebrain including the cerebral cortex, hippocampus, lateral septal nucleus and hypothalamus, compared with control rats. These findings suggest that chronic toluene exposure might influence catecholaminergic neural systems.

Animals↗
PubMed1995

Enzyme-linked immunosorbent assay (ELISA) for Aleuria aurantia lectin-reactive serum cholinesterase to differentiate liver cirrhosis and chronic hepatitis.

We have established an enzyme-linked immunosorbent assay (ELISA) for total serum cholinesterase (ChE) using 2 new monoclonal antibodies (mAbs) to ChE (E.C.3.1.1.8). The ELISA results correlated very well with the results of a serum ChE activity assay, which has been widely used for differentiating patients with liver diseases, such as hepatocellular carcinoma, liver cirrhosis and chronic hepatitis, from normal individuals. We next established an ELISA for Aleuria aurantia lectin (AAL)-reactive serum ChE using one of the anti-ChE mAbs and AAL, which specifically recognizes L-fucose alpha 1-->2, L-fucose alpha 1-->3, and L-fucose alpha 1-->6 structures. The ratio of AAL-reactive ChE to total ChE in sera determined by the two ELISA procedures was increased in patients with hepatocellular carcinoma and liver cirrhosis compared with patients with chronic hepatitis and normal individuals. We then applied the ELISA for AAL-reactive ChE directly to 10-fold-diluted serum samples, and by using a cut-off value of the mean + 2S.D. for normal individuals, we could effectively differentiate liver cirrhosis from chronic hepatitis. This single ELISA for AAL-reactive ChE could be a useful aid in clinical diagnosis.

Antibodies, Monoclonal↗
PubMed1995

Detection of vanadyl-nitrogen interaction in organs of the vanadyl-treated rat: electron spin echo envelope modulation study.

ESEEM spectroscopy was applied for the first time to organs of an animal, viz. the kidney and liver of the rat treated with vanadyl sulfate. The aim of this study is to investigate the in vivo coordination structure of vanadyl ions administrated, and to gain information concerning the insulin-mimic activity of vanadium. ESEEM measurements for kidney and liver performed at 77 K have established nitrogen coordination to a certain percentage of vanadyl ion in the organs. The rotios of nitrogen-coordinating vanadyl ion were estimated as 70-80% in the liver, and 50-55% in the kidney. Isotropic portions of the 14N HFC were estimated as magnitude of Aiso approximately 5.0 MHz for liver, and approximately 5.2 MHz for kidney, indicating that the coordinating nitrogen is an amino nitrogen. Coordination of the Lys epsilon-amine or the N-terminal alpha-amine of a protein or (a peptide) to vanadyl ion in vivo is suggested.

Animals↗
PubMed1995

Purification of a Ras-dependent mitogen-activated protein kinase kinase kinase from bovine brain cytosol and its identification as a complex of B-Raf and 14-3-3 proteins.

We previously purified a protein factor, named REKS (Ras-dependent Extracellular Signal-regulated Kinase (ERK)/mitogen-activated protein kinase Kinase (MEK) Stimulator), from Xenopus eggs by use of a cell-free assay system in which recombinant GTP gamma S (guanosine 5'-(3-O-thio)triphosphate)-Ki-Ras activates recombinant MEK. By use of this assay system, we purified here bovine REKS to near homogeneity from the cytosol fraction of bovine brain by successive chromatographies of Mono S, Mono Q, GTP gamma S-glutathione S-transferase-Ha-Ras-coupled glutathione-agarose, and Mono Q columns. It was composed of three proteins with masses of about 95, 32, and 30 kDa as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The 95-, 32-, and 30-kDa proteins were identified by immunoblot analysis to be B-Raf protein kinase, 14-3-3 protein, and 14-3-3 protein, respectively. Moreover, the REKS activity was specifically immunoprecipitated by an anti-B-Raf antibody. Bovine REKS was activated by lipid-modified GTP gamma S-Ki-Ras far more effectively than by a lipid-unmodified one. Lipid-modified GDP-Ki-Ras was inactive. Exogenous addition of 14-3-3 proteins stimulated further the REKS activity both in the presence and absence of GTP gamma S-Ki-Ras. These results indicate that at least one of the direct targets of Ras is B-Raf complexed with 14-3-3 proteins in bovine brain.

14-3-3 Proteins↗
PubMed1995

Immunohistochemical alterations in neuropeptide Y-positive nerve elements in rat cerebral cortex following acute phencyclidine treatment.

Phencyclidine (PCP) is a dissociative drug and has been known to be an antagonist of N-methyl-D-aspartate (NMDA) receptor. We examined possible effects of acute treatment with PCP on neuropeptide Y (NPY) immunoreactive nerve fibres and cell bodies in rat forebrain by immunocytochemistry combined with morphometric analysis. Following the treatment, significant alterations were observed throughout the cerebral cortex, compared with controls. NPY-positive perikarya were increased in number (178%) whereas NPY-positive fibres and terminals were decreased in area (38%). The result suggests that the cortical NPY neuronal system is controlled, at least partly, by glutamatergic inputs via NMDA receptor-mediated mechanisms.

Animals↗