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Biomedical subjects

K Kawaguchi

Publications and source records attributed to K Kawaguchi.

At least 55 records · Page 3Linked to original sources
PubMed1999

Casein kinase II inhibitors isolated from two Brazilian plants Hymenaea parvifolia and Wulffia baccata.

Two dihydroflavonol rhamnosides (1 and 2) isolated from the bark of Hymenaea parvifolia and two pentacyclic triterpenoids (3 and 6) obtained from the leaves of Wulffia baccata have been found to exhibit inhibitory effects of casein kinase II (CK-II) dose-dependently, suggesting that at higher doses more than 10 microM, these four compounds may act as potent CK-II suppressors of the CK-II-mediated activation of 60S acidic ribosomal P proteins in vitro.

Brazil↗
PubMed1999

Biochemical and electrochemical characterization of quinohemoprotein amine dehydrogenase from Paracoccus denitrificans.

A new quinohemoprotein amine dehydrogenase from Paracoccus denitrificans IFO 12442 was isolated and characterized in views of biochemistry and electrochemistry. This enzyme exists in periplasm and catalyzes the oxidative deamination of primary aliphatic and aromatic amines. n-Butylamine or benzylamine as a carbon and energy source strongly induces the expression of the enzyme. Carbonyl reagents inhibit the enzyme activity irreversibly. This enzyme is a heterodimer constituted of alpha and beta subunits with the molecular mass of 59.5 and 36.5 kDa, respectively. UV-vis and EPR spectroscopy, and the quinone-dependent redox cycling and heme-dependent peroxidative stains of SDS-PAGE bands revealed that the alpha subunit contains one quinonoid cofactor and one heme c per molecule, while the beta subunit has no prosthetic group. The redox potential of the heme c moiety was determined to be 0.192 V vs NHE at pH 7.0 by a mediator-assisted continuous-flow column electrolytic spectroelectrochemical technique. The analysis of the substrate titration curve allowed the evaluation of the redox potential of the quinone/semiquinone and semiquinone/quinol redox couples as 0.19 and 0.11 V, respectively.

Dithionite↗
PubMed1999

Suppression of lipopolysaccharide-induced tumor necrosis factor-release and liver injury in mice by naringin.

Suppressive effects of naringin on lipopolysaccharide-induced tumor necrosis factor (TNF) release followed by liver injury were investigated. Intraperitoneal (i.p.) treatment with naringin prior to an intravenous (i.v.) challenge of lipopolysaccharide significantly reduced serum TNF levels in a dose-dependent manner and was the most effective when administered 60 min prior to lipopolysaccharide challenge. Treatment with naringin 3 h prior to lipopolysaccharide challenge resulted in complete protection from lipopolysaccharide lethality in D-galactosamine-sensitized mice. Histological estimation revealed that massive cell infiltration followed by severe injury developed in the livers of lipopolysaccharide-treated and D-galactosamine-treated mice unless they had been pretreated with naringin. Appearance of apoptotic cells was also found to decrease by treatment with naringin. Increases in serum levels of aspartate aminotransferase, alanine aminotransferase and creatine kinase, responsible for lipopolysaccharide-induced liver injury, blocked by naringin administration and the levels were nearly to the normal level. These results indicate that action of naringin is mediated through suppression of lipopolysaccharide-induced TNF production.

Alanine Transaminase↗
PubMed1999

Parallel dose-response studies of the voltage-dependent Na+ channel antagonist BW619C89, and the voltage-dependent Ca2+ channel antagonist nimodipine, in rat transient focal cerebral ischaemia.

We have compared two classes of putative neuroprotectants, the voltage-dependent Na+ channel antagonist BW619C87 [4-amino-2-(4-methyl-1-piperazinyl)-5-(2,3,5-trichlorophenyl) pyrimidine], and the voltage-dependent Ca2+ channel antagonist nimodipine, in a rat model of transient focal cerebral ischaemia. BW619C87 (10-50 mg/kg) or nimodipine (10-100 microg/kg) were injected intravenously 5 min before induction of 2 h transient focal cerebral ischaemia via intraluminal thread occlusion of the middle cerebral artery. BW619C87 was a potent neuroprotectant over the range tested, maximally reducing the volume of hemispheric ischaemic damage by 51% at the 50 mg/kg dose. Nimodipine maximally reduced ischaemic damage by 33% at the 50 microg/kg dose, although the maximal level of neuroprotection afforded by BW619C89 and nimodipine was not significantly different. This is the first study to compare these two classes of drug directly in a model of middle cerebral artery occlusion with reperfusion, and it supports the effectiveness of both as neuroprotectants.

Animals↗
PubMed1999

Millimeter- and Submillimeter-Wave Spectrum of Methylene Fluoride-d(2).

The millimeter- and submillimeter-wave spectrum of methylene fluoride-d(2) (CD(2)F(2)) has been observed in the region between 200 and 415 GHz. The spectrum was recorded using a frequency-modulated millimeter- and submillimeter-wave spectrometer. More than 400 rotational transitions up to J </= 60 and K(a) </= 21 in the ground state and more than 200 rotational transitions up to J </= 48 and K(a) </= 9 in the v(4) = 1 vibrational state have been assigned. The lines assigned are simultaneously least-squares fitted along with the microwave data in the Watson's A- and S-reduced Hamiltonian. Improved values have been obtained for the rotational constants and quartic centrifugal distortion constants, including for the first time, sextic distortion constants of the ground state as well as the v(4) = 1 state. Copyright 1999 Academic Press.

Journal Article↗
PubMed1999

Castleman disease presenting with ophthalmic signs and symptoms.

PURPOSE: To describe a patient with multicentric Castleman disease who was initially examined with ophthalmic signs and symptoms. METHODS: Case report. A 71-year-old man was initially examined with swelling of both upper eyelids and diplopia of 2 months' duration. RESULTS: Medical evaluation and right axillary lymph node biopsy disclosed Castleman disease. Systemic corticosteroid treatment temporarily resolved signs and symptoms, but the patient died of recurrence with cytomegalovirus and Aspergillus infection 10 months after initial examination. CONCLUSIONS: Multicentric Castleman disease is a rare but distinct disorder that may present initially with ocular signs and symptoms. This disease must be included in the differential diagnosis of orbital pseudotumor and lymphoma.

Aged↗
PubMed1999

Molecular cloning of a cell cycle regulation gene cyclin H from ischemic rat brain: expression in neurons after global cerebral ischemia.

Gene expression plays an important role in determining the fate of neurons after ischemia. To identify additional genes that promote survival or execute programmed cell death in ischemic neurons, a subtractive cDNA library was constructed from hippocampus of rats subjected to global ischemia. With use of a differential screening technique, a cDNA was identified that was up-regulated after ischemia. The cDNA was found to have high homology with human cyclin H at both the nucleotide level (89%) and the amino acid level (93%). Northern blotting detected cyclin H mRNA in nonischemic and ischemic brains. In situ hybridization studies revealed that cyclin H message was found in hippocampal neurons in nonischemic brain. After ischemia, expression was increased primarily in the dentate gyrus and CA3 regions of hippocampus. Expression of cyclin H protein, detected by western blotting of hippocampal tissue, was increased after global ischemia, but expression of cyclins B1 and D1 and other related cell cycle genes (Cdk7 and Cdc2) was not increased. Cyclin H immunoreactivity was found exclusively within neurons. After ischemia, there was increased immunoreactivity within neurons in dentate gyrus, CA3, and cortex. Thus, cyclin H is expressed in normal postmitotic neurons and expression is increased in neurons that are ischemic yet survive. These results suggest that cyclin H may have functions in neurons other than cell cycle regulation, including other known functions such as DNA repair.

Amino Acid Sequence↗
PubMed1999

Colony stimulating factor-inducing activity of hesperidin.

To evaluate immunomodulating activities of bioflavones, colony-stimulating factor (CSF)-inducing activity of two dihydroflavones, three flavones and three flavonols were tested. These samples were suspended in saline and injected intraperitoneally (i.p.) into mice at a dose of 1 mg 6 h before bleeding. All compounds carrying the glucosyl-rhamnose moiety showed potent activity. Among them, hesperidin exhibited the strongest activity. Serum CSF production in mice injected with 1 mg hesperidin reached a peak at 9 h later. The activity of hesperidin was dose-dependent at a range of 0.3 to 20 mg/mouse.

Adjuvants, Immunologic↗
PubMed1999

Expression of GLUT4 glucose transporter protein in adipose tissue and skeletal muscle from streptozotocin-induced diabetic pregnant rats.

Depletion of GLUT4, the primary glucose transporter protein in adipose tissue and skeletal muscle, is reported to contribute to insulin resistance in pregnancy or diabetes. To examine this phenomenon, the expression of GLUT4 protein was assessed by Western blotting in streptozotocin-induced diabetic pregnant rats. In adipose tissue, relative to control, it was decreased by 30% in the normal pregnant group (p<0.001), by 37% in the diabetic nonpregnant group (p<0.01) and by 65% in the diabetic pregnant group (p<0.001). On the other hand, no significant variation was evident among the groups in skeletal muscle. To assess the mechanisms responsible for depletion of GLUT4 protein in adipose tissue, we quantitated levels of GLUT4 mRNA with a RNase protection assay. It was decreased by 44% in the normal pregnant group (p<0.05) and by 55% in the diabetic pregnant group (p<0.05), but not altered in the diabetic nonpregnant group. These results suggest that the depletion of GLUT4 protein in adipose tissue is a factor contributing to insulin resistance in pregnancy or diabetes, especially when the two states exist in combination.

Adipose Tissue↗
PubMed1999

Induction of isoflavonoid and retrochalcone branches of the flavonoid pathway in cultured Glycyrrhiza echinata cells treated with yeast extract.

Yeast extract-treated suspension cultures of a new cell line, AK-1, of Glycyrrhiza echinata were induced to produce an isoflavonoid phytoalexin (medicarpin) and metabolites of retrochalcone/flavone pathway (echinatin, licodione, and 7,4'-dihydroxyflavone). From these cells, putative full-length cDNAs encoding cytochrome P450s, (2S)-flavanone 2-hydroxylase and isoflavone 2'-hydroxylase, were cloned.

Cloning, Molecular↗
PubMed1999

Phenochalasins, inhibitors of lipid droplet formation in mouse macrophages, produced by Phomopsis sp. FT-0211.

Phomopsis sp. FT-0211, a soil isolate, was found to produce inhibitors of lipid droplet formation in mouse peritoneal macrophages. Structurally related new compounds designated phenochalasins A and B were isolated from the fermentation broth of the producing strain by solvent extraction, ODS column chromatography and preparative HPLC. Phenochalasin A caused a dose-dependent reduction in the number and size of lipid droplets in macrophages without any cytotoxic effect at least up to 20 microm. On the other hand, phenochalasin B showed inhibition of lipid droplet formation with a severe cytotoxic effect on macrophages.

Animals↗
PubMed1999

Detection of GPI-anchored protein-deficient cells in patients with aplastic anaemia and evidence for clonal expansion during the clinical course.

The incidence of patients with aplastic anaemia (AA) who show a deficiency of glycosylphosphatidylinositol (GPI)-anchored proteins on their peripheral blood (PB) or bone marrow (BM) cells is higher than that previously reported. We analysed the expression of CD55 or CD59 on PB and BM cells and those of colonies and bursts formed in cultures with marrow cells from AA patients. 4/21 (19%) AA cases later developed paroxysmal nocturnal haemoglobinuria (PNH). 7/17 (41. 2%) AA cases showed a subpopulation without GPI-anchored proteins. The defect characteristic for PNH was observed only on the colonies/bursts but not on the PB or BM cells in three cases. We found the affected colonies/bursts in cultures using thawed marrow cells which had been cryopreserved at the diagnosis of aplasia in one patient who developed PNH 3 years later. Two different mutations of the PIG-A gene were found in the colonies/bursts at the time of AA. The nucleotide sequences were identical between the colonies/bursts at the time of AA and those after the transition to PNH. However, one of the mutations was detected only at the haemopoietic progenitor level but not in PB granulocytes. There may be latent subclones with PNH abnormalities which could expand to the level of clinical detection, or which do not progress and remain indolent for a relatively long time, implying the different extents of clonal expansion among the affected progenitors.

Adolescent↗
PubMed1999

An indirect method of estimating VO2 from work load using arm-cranking in adult hemiplegic patients.

The purpose of this study was to develop an oxygen consumption (VO2) measurement for adult hemiplegic patients during an incremental exercise arm-cranking test. Fifty-five adult hemiplegic patients performed a three-stage arm-cranking exercise test while VO2 was measured. The control group consisted of thirteen healthy elderly persons who performed a similar arm-cranking test until exhaustion. The results indicated that there was a significant difference in VO2 during rest periods between the adult hemiplegic and control groups. Based on data analysis, we developed an equation to estimate the VO2 for adult hemiplegic patients: VO2(ml/min) = (kgm/min x 4.2 ml/kgm) + ((4.2 ml/kg/min x kg body weight) + 105.6 ml/min) (r = 0.847), while the equation for the controls was VO2(ml/min) = (kgm/min x 4.3 ml/kgm) + ((2.9 ml/kg/min x kg body weight) + 105.5 ml/min) (r = 0.932). There was no significant difference between the estimated VO2 for the new equations (nVO2) and the measured VO2 (mVO2) in the two groups at any stage. In our data analysis, based on an estimated VO2 from the American College of Sports Medicine (ACSM) equation (aVO2), the nVO2 and mVO2 at each stage showed lower aVO2 than either nVO2 or mVO2 in each subject (p < 0.05). These findings suggest that the ACSM equation is unlikely to be applicable for estimating VO2 for one hand arm-cranking exercise. In conclusion, the new equations established in this study, when used with a specific prescribed exercise testing protocol, would allow us to estimate VO2 more accurately for both adult hemiplegic patients and healthy elderly persons.

Adult↗