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Biomedical subjects

A Kanazawa

Publications and source records attributed to A Kanazawa.

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

Depletion of dietary n-3 fatty acid affects the level of cyclic AMP in rat hippocampus.

Prolonged depletion of dietary n-3 fatty acid induces a neurological disturbance. To ascertain the deficit of neurotransmission at the time of n-3 deficiency, the concentrations of cAMP and inositol triphosphate, and the activities of protein kinases A and C were examined in vitro in rat hippocampus. Furthermore, the saturation binding study of [3H]quinuclidinyl benzilate, a specific antagonist to muscarinic cholinergic receptor, was performed. Rats were fed a safflower oil diet as the deficient group and a soybean oil diet as the control group. Hippocampi were obtained from rats in the 3rd generation in the deficient group and in the 2nd generation in the control group. Dietary effect was not observed in the parameters except for the concentration of cAMP, which was significantly higher in the deficient group than in the control group.

Animals↗
PubMed1999

[A 96-year-old man with consciousness disturbance, convulsion, and left hemiplegia of acute onset].

We report a 96-year-old Japanese man who developed a sudden onset of left hemiplegia and coma. He was found to have diabetes mellitus, hypertension, and atrial fibrillation since 1996 with occasional episodes of congestive heart failure. He was otherwise apparently well until July 5 of 1997 when he developed a sudden onset of unresponsiveness and convulsion involving his right hand and was admitted to our hospital. On admission, his BP was 210/120 mmHg, heart rate 76/min and irregular, BT 36.5 degrees C, and Cheyne-Stokes respiration. General medical examination was otherwise unremarkable. Neurologic examination revealed semicoma, conjugated deviation to the right, loss of oculocephalic response, left facial paresis of central type, flaccid left hemiplegia, and bilateral Babinski sign. Pertinent laboratory findings are as follows: BUN 47 mg/dl, creatinine 1.46 mg/dl, GPT 69 IU/l, LDH 1,142 IU/l, and CK 385 IU/l. A chest x-ray film revealed cardiac enlargement and EKG showed left ventricular hypertrophy and atrial fibrillation. Cranial CT scan revealed low density areas involving the right anterior cerebral and the right posterior cerebral artery territories. He was treated with an intravenous osmotic agent and short course of intramuscular steroid. He remained unconscious despite these treatment and developed sudden cardiopulmonary arrest three weeks after the admission. The patient was discussed in a neurological CPC and the chief discussant arrived at the conclusion that the patient had suffered from cerebral embolism of cardiac origin. The cause of the death was ascribed to acute subendocardial myocardial infarction. Most of the participants agreed with this conclusion. Postmortem examination revealed an old subendocardial myocardial infarction involving the posterior septal region and posterolateral wall of the left ventricle. Neuropathologic examination revealed hemorrhagic infarctions involving the territories of the right anterior cerebral, right middle cerebral, right posterior cerebral, and left anterior cerebral arteries. The left A1 portion of the anterior cerebral artery was hypoplastic, and the left pericallosal artery appeared to have been receiving blood supply from the right anterior cerebral artery through the anterior communicating artery. The large arteries in the base showed marked arteriosclerosis; particularly, the initial portion of the right posterior artery showed near complete arteriosclerotic occlusions. These characteristic arterial changes appeared to be the reason why this patient suffered from an extensive infarction from what appeared to have been a single episode of cerebral embolism probably initially involving the right internal carotid artery.

Aged↗
PubMed1998

The beneficial effect of phosphocreatine accumulation in the creatine kinase transgenic mouse liver in endotoxin-induced hepatic cell death.

Purpose. The purpose of this study was to investigate the relationship between hepatic energy status and liver injury during sepsis, using transgenic mice which express creatine kinase in the liver catalyzing the phosphocreatine/creatine system. Methods. Creatine kinase transgenic mice were fed with normal rodent chow or chow containing 10% creatine for 5 days. Lipopolysaccharide (0.2 mg/kg) combined with d-galactosamine (600 mg/kg) was administered intraperitoneally. Results. Eighty percent of the creatine-fed transgenic mice had survived at 48 h post-d-galactosamine and lipopolysaccharide administration, compared with none of the normally fed transgenic mice. Hepatic phosphocreatine and ATP levels in the normally fed transgenic mice were significantly lower than those in the creatine-fed transgenic mice before and after lipopolysaccharide combined with d-galactosamine was administered. Massive hepatic hemorrhagic necrosis with apoptosis was seen in response to d-galactosamine and lipopolysaccharide in normally fed transgenic mice. These results are consistent with a significant increase in serum aminotransferase at 8 h. In contrast, there were faint necrotic changes in the liver with minimal cellular infiltration in creatine-fed transgenic mice. Conclusions. Maintenance of hepatic ATP levels protects from sepsis-induced liver injury and mortality.

Alanine Transaminase↗
PubMed1998

Small interspersed sequences that serve as recombination sites at the cox2 and atp6 loci in the mitochondrial genome of soybean are widely distributed in higher plants.

Mitochondrial DNA (mtDNA) fragments that contain cox2 and atp6 were cloned from a wild soybean (Glycine soja, accession 'B09002') and from a cultivated soybean (G. max, 'Harosoy'). Comparison of these DNAs revealed that two sets of repeated sequences, namely, 299 bp and 23 bp, were present in the 5' regions of cox2 and atp6. The 299-bp and 23-bp repeats were present close to each other on the 5' flanking region and the 5' part of the coding region of cox2 in both 'Harosoy' and 'B09002', as well as on the 5' flanking region of atp6 in 'Harosoy', while these two repeats were separated by a 706-bp nucleotide sequence that contained a truncated sequence of nad3 at the 5' flanking region of atp6 in 'B09002'. The mtDNA configurations upstream from atp6 and cox2 found in 'Harosoy' appeared to have been generated from configurations of cox2 and atp6 found in 'B09002' via recombination across the 299-bp or 23-bp repeated sequences, or vice versa, in the mitochondrial genome of the hypothetical progenitor of these plants. The 299-bp sequence was found to be interspersed in the mitochondrial genome. Eight loci were identified that include mtDNA configurations that are inter-convertible with each other via recombination across this sequence in 'B09002'. Various loci on the mitochondrial genomes of higher plants that harbor segments of the 299-bp repeats in Glycine were identified.

Base Sequence↗
PubMed1998

Differential changes in copy numbers of rice mitochondrial plasmid-like DNAs and main mitochondrial genomic DNAs that depend on temperature.

The mitochondria of rice contain four kinds of circular plasmid-like DNAs, namely, B1, B2, B3 and B4, in addition to the main mitochondrial genomic DNAs. In order to examine the genetic stability of mitochondrial plasmid-like DNAs, changes in the amounts of plasmid-like DNAs and main mitochondrial genomic DNAs were analyzed in calli that had been cultured at various temperatures. The observed effect of temperature on the levels of plasmid-like DNAs was larger than that on the main mitochondrial genomic DNAs. A significant reduction in the copy number of plasmid-like DNAs was detected in calli cultured at 35 degrees C, as compared to 20 degrees C, 25 degrees C and 30 degrees C. The effect of temperature on DNA synthesis in isolated mitochondria was also analyzed. Synthesis of the main mitochondrial genomic DNAs occurred at all the temperatures examined, whereas synthesis of plasmid-like DNAs occurred only over a limited range of temperatures. The results of both in vivo and in vitro analyses suggest that plasmid-like DNAs are less stably maintained than the main mitochondrial genomic DNAs, which is consistent with the notion that the transmission of mitochondrial plasmid-like DNAs from one generation to the next may be unstable under unusual conditions.

Cell-Free System↗
PubMed1998

Evolutionary changes in the structures of the cox2 and atp6 loci in the mitochondrial genome of soybean involving recombination across small interspersed sequences.

Mitochondrial DNA (mtDNA) fragments that contained cox2 or atp6 loci were cloned from three accessions of wild soybean (Glycine soja) in order to understand the evolutionary changes of mitochondrial genomes in the genus Glycine subgenus Soja. Cox2 was cloned as a single configuration, while atp6 was cloned as either one or two configurations from each accession. Structural variations were detected in the 5' upstream region of cox2 and in both the 5' upstream and 3' downstream regions of atp6. These variations appeared to be the results of recombination events. A comparison of the mtDNA fragments previously cloned from a cultivated soybean (G. max) and a wild soybean revealed various sites of recombination, as well as various combinations of the 5' and 3' regions, at the cox2 and atp6 loci. Some of the cloned fragments were found to contain a set of repeated sequences, namely 299-bp and 23-bp repeats in the 5' region of cox2 or atp6, which were interspersed in the mitochondrial genome in the subgenus Soja. Recombination events involving the 299-bp or 23-bp repeated sequences were shown to account for the generation of structural variations in the 5' regions of these loci.

Base Sequence↗
PubMed1998

Use of hyaluronic acid binding protein for detection of hyaluronan in ligature-induced periodontitis tissue.

This study was designed to demonstrate, by use of biotin-labeled hyaluronic acid binding protein (HABP) and an avidin-enzyme system, the localization of hyaluronan (HA) in periodontal tissue of beagle dogs during experimentally induced periodontitis. Experimental periodontitis was induced in the dogs by ligation of the gingival sulcus. Experimental tissue was collected at 0, 3, 7 and 21 days after ligation. HA was revealed by strong staining in the intercellular space around epithelial cells and periodontal ligament, and by light staining in the gingival connective tissue. According to the progression of periodontal tissue breakdown, HA was detected in a small number of leukocytes and monocytes, on the surface of osteoclasts, the surface of alveolar bone, thickened endothelium and in epithelial cells related to rete peg formation. Streptomyces hyaluronidase-treated specimens gave negative staining. This study suggests that HA may be associated with the inflammatory reaction in experimental periodontitis tissue.

Alveolar Process↗
PubMed1998

Sequence variation of chloroplast DNA that involves EcoRI and ClaI restriction site polymorphisms in soybean.

Restriction fragment length polymorphisms (RFLPs) of EcoRI-and ClaI-digested chloroplast DNA (cpDNA) within the genus Glycine subgenus Soja were characterized. Two mutations were found to be responsible for the EcoRI and ClaI restriction site polymorphisms, and both were located in a region in which many ribosomal protein genes are clustered. This region is within the large single copy region of cpDNA and is located close to an inverted repeat. The locations of restriction sites of EcoRI and ClaI in the cpDNA region were analyzed by DNA gel-blot analyses and PCR amplification, which were followed by sequencing analyses. The EcoRI site polymorphism was found to have occurred in the intergenic spacer between rps11 and rpl36, while the ClaI site polymorphism was located within the 3' part of the coding region of rps3. The mutations that cause EcoRI and ClaI polymorphisms were both found to be single base substitutions. In addition to these polymorphisms, novel sequence variations in soybean cpDNA were detected near the sites of these mutations. Previously, it was shown that cultivated soybeans could be classified into three groups (I, II, and III) based on their cpDNA RFLPs. A comparison of the cpDNA sequences of soybeans in the present study was consistent with the notion that the cpDNA of group II soybeans is an intermediate between the cpDNAs of groups I and II.

Base Sequence↗
PubMed1998

Phylogenetic relationships of the mitochondrial genomes in the genus Glycine subgenus Soja.

Restriction fragment length polymorphisms (RFLPs) of mitochondrial DNA (mtDNA) of wild and cultivated soybeans were analyzed to study their phylogenetic relationships. The observed number of differences in hybridization profiles greatly varied (1-17 patterns) with both the mtDNA probes and the restriction enzymes that were used. A cladistic analysis was conducted based on the RFLP data. In the parsimonious tree, four distinct groups appeared among 20 accessions of the subgenus Soja representing 20 mitochondrial genome types. Common features with regard to geographic distributions in natural populations in East Asia were observed among the mitochondrial genome types of wild soybean that belonged to the same group: one clade consisted of genome types IIg and VIIg that are detected with very low frequencies; another clade consisted of genome types Ic, Id, Ie, and Ik whose distributions are highly biased mainly in Japan. The genome types that are widely distributed in East Asia such as IVa, IVb, and Va were not grouped into the same clade. The mitochondrial genome types IIIb, IVb, and IVc, in which two different chloroplast genome types exist, belonged to the same clade. Possible changes in mitochondrial genomes during the expansion of the distribution of wild soybeans in East Asia were discussed.

DNA, Mitochondrial↗
PubMed1998

Dietary supplementation of catechins and alpha-tocopherol accelerates the healing of trinitrobenzene sulfonic acid-induced ulcerative colitis in rats.

The effects of dietary catechins and alpha-tocopherol on inflammatory bowel disease in rats were examined. Male 9-week-old rats were intracolonically administrated trinitrobenzene sulfonic acid (TNBS) and fed the experimental diets containing 0.05% catechin and 0.025% alpha-tocopherol for 1 week, then dissected. The extent of colitis-induced TNBS was assessed macroscopically. The supplementation of catechins and alpha-tocopherol significantly decreased colonic damage compared with the group fed the basal diet (the disease control). In particular, catechin feeding completely inhibited the development of colon adhesions. Colonic myeloperoxidase (MPO) activity, which is a marker of neutrophil infiltration into the colonic mucosa, was lower in the groups that had been given catechins and alpha-tocopherol. The levels of thiobarbituric acid reactive substances in colon was highest in the disease control group; however, the differences among the groups were not significant. Plasma alkaline phosphatase activity was maintained at normal levels in the rats supplemented with catechins and alpha-tocopherol. These results suggest that catechins and alpha-tocopherol have anti-inflammatory effects on TNBS-induced rat colitis.

Alkaline Phosphatase↗
PubMed1997

Oxygen dependence of photosynthetic electron transport in a bacteriochlorophyll-containing rhizobium.

Bacteriochlorophyll-containing rhizobia, which form nitrogen-fixing nodules on the stems and roots of the legume Aeschynomene, grow photosynthetically only in the presence of oxygen or auxiliary electron acceptors. We show that, in whole cells of the Rhizobium strain BTAi 1, a single-turnover excitation flash photooxidized c-type cytochrome under aerobic but not anaerobic conditions. Light-induced fluorescence yield changes show that under anaerobic conditions, the primary acceptor quinone, Q(A), is predominantly in the reduced state and so unable to accept electrons. Thus, as is the case for the aerobic photosynthetic bacterium Roseobacter denitrificans, over-reduction of Q(A) likely prohibits photosynthesis under anaerobic conditions.

Aerobiosis↗
PubMed1997

Humoral injury in porcine livers perfused with human whole blood.

BACKGROUND: We investigated the influence of humoral injury during xenoperfusion of porcine livers by human blood. METHODS: The porcine livers were perfused under physiological conditions for 9 hr. The perfusates consisted of porcine whole blood in group 1, human whole blood in group 2, and human whole blood with soluble complement receptor type 1 (300 microg/ml) in group 3. RESULTS: Liver enzyme release and serum hemoglobin in group 2 increased significantly after 3 hr of xenoperfusion, compared with those in group 1 and group 3 (P<0.05). Severe histological damage with minimal cellular infiltration was observed in group 2 after 6 hr of xenoperfusion, but was present only at trace levels in group 1 and group 3. In group 2, von Willebrand factor, a possible target of natural antibodies, was induced on sinusoidal endothelial cells after 3 hr of xenoperfusion, correlating with diffuse deposition of human IgM and membrane attack complex. In group 3, von Willebrand factor, human IgM, and membrane attack complex staining in the intralobular region were present at trace levels. In group 3, the indocyanine green removal capacity, representing hepatocyte function, was significantly higher than in group 2 (P<0.05). CONCLUSIONS: Based on these results, we suggest that humoral injury is a major cause of liver damage during liver xenoperfusion. The pattern of humoral injury in xenoperfused livers may be attributed to anatomical features of the liver and unique responses of sinusoidal endothelial cells to xenoperfusion.

Animals↗
PubMed1997

Prostaglandin E1 resuscitates hepatic organic anion transport independent of its hemodynamic effect after warm ischemia.

Prostaglandin E1 (PGE1) is a promising agent against ischemic liver damage, but direct evidence of the benefit to intrinsic hepatocyte function has been lacking. We demonstrate here that organic anion transport can be supported by treatment with PGE1 even at a lower dose which does not affect hepatic microcirculation in rabbits with liver inflow occlusion. Near-infrared spectroscopy was applied to directly measure hepatic clearance of indocyanine green (ICG), an exogenous organic anion, and to estimate microcirculation as measured by oxygen saturation and the content of hemoglobin in the sinusoid. Also, morphological changes in microtubules, the cytoskeleton which is known to be associated with organic anion transport, and energy status, as measured by adenine nucleotide levels, were observed. ICG removal rate in hepatocytes decreased significantly from 0.100 +/- 0.018 to 0.027 +/- 0.019 min-1 (mean +/- SD, P < 0.01) by 60-min warm ischemia, whereas the value increased to 0.082 +/- 0.030 min-1 (P < 0.05) when PGE1 was given at a dose of 0.05 microgram/kg/min. The treated livers also showed early reorganization of microtubules, as well as amelioration of ATP resynthesis after reperfusion. However, there were no significant differences in intraoperative changes in oxygen saturation and the content of hemoglobin in the sinusoid between PGE1-treated and untreated groups, indicating that the influence of PGE1 at this dose on hemodynamic changes is not considerable. These results indicate that PGE1 resuscitates an inherent hepatocyte function of organic anion transport on reperfusion after warm ischemia and suggest that the benefit could be attributed solely to direct action on hepatocytes.

Adenine Nucleotides↗
PubMed1997

The protective effects of prostaglandin E1 on sinusoidal endothelial cells in xenogeneic pig liver perfusion.

The effects of prostaglandin E1 (PGE1) on hepatic sinusoidal endothelial cells (SEC) in the xenogeneic immunoreaction were investigated. Porcine livers were perfused with fresh human blood via the portal vein (PV) and the hepatic artery (HA) either with the administration of PGE1 (Group PG) or without PGE1 (Group C). The creatine kinase-BB component (CK-BB) in the perfusate was measured to assess SEC damage. SEC activation and complement activation were evaluated immunohistochemically by the expression of von Willebrand factor (vWF) and by the deposition of membrane attack complex (MAC), respectively. Xenoperfusion in Group C was discontinued between 4 and 6 hr due to the rapid elevation of HA pressures and the massive loss of perfusate. In Group PG, both PV and HA pressures were kept stable for up to 9 hr. In Group C, severe interlobular bleeding and diffuse extrasinusoidal hemorrhage were observed at 4 hr histologically, while in Group PG, the hepatic architecture was maintained without hemorrhage at 6 hr. MAC was markedly deposited on SEC and parenchymal cells at 3 hr in both groups. The amount of vWF, however, was expressed on SEC in large amounts at 1 hr in Group C, while small amounts were expressed at 1 hr in Group PG. In Group PG, CK-BB release was significantly lower than in Group C (P < 0.01). These results suggest that PGE1 suppressed SEC activation and protected the impairment of hepatic SEC during xenoperfusion without suppressing complement activation, resulting in the prolongation of xenogeneic liver perfusion.

Alprostadil↗
PubMed1997

Increased hepatic beta-oxidation of docosahexaenoic acid, elongation of eicosapentaenoic acid, and acylation of lysophosphatidate in rats fed a docosahexaenoic acid-enriched diet.

Rats were fed a diet supplemented with corn oil (n-3 deficient), soy oil, or a mixture containing 8% 22:6n-3 ethyl ester for 6 wk. The hepatic capacities for the beta-oxidation and synthesis of 22:6n-3, in addition to the acylation of lysophosphatidate, were tested in vitro. In rats that were fed a 22:6n-3-enriched diet, both the beta-oxidation of 22:6n-3 and elongation of 20:5n-3 were enhanced compared to those in rats fed the other diets. Acylation of lysophosphatidate was also enhanced in rats fed a 22:6n-3-enriched diet, while the rate of dephosphorylation of phosphatidate was not changed. The amount of 22:6n-3 in the liver was much less than that consumed in a docosahexaenoic acid-enriched diet. These results suggest that a significant amount of dietary 22:6n-3 was degraded via beta-oxidation, and that a portion of the retroconverted 20:5n-3 was recycled for the synthesis of 22:6n-3. The recycling of 20:5n-3 might contribute to the low level of 22:6n-3 in rats fed an n-3-deficient diet.

Acylation↗
PubMed1997

Insulin resistance as an independent risk factor for carotid artery wall intima media thickening in vasospastic angina.

Studies have shown the presence of insulin resistance together with compensatory hyperinsulinemia in vasospastic angina as well as obstructive coronary artery disease. There is growing evidence that the development of coronary atherosclerosis may be closely related to systemic atherosclerosis as well as coronary spasm. However, no information is available about the possible relationship between insulin resistance and the existence of carotid atherosclerosis in vasospastic angina without segmental stenosis or luminal irregularities in coronary angiograms. To evaluate the independent effect of insulin resistance on carotid intima media thickening, we performed insulin sensitivity tests (steady-state plasma glucose method) on 40 patients with vasospastic angina and 24 control subjects with angiographically intact coronary arteries. Both oral glucose tolerance tests and lipid analyses were performed. Using B-mode ultrasonography, we assessed intima media thickness and plaque formation of common carotid arteries in these subjects. The steady-state plasma glucose level in the vasospastic angina group was about twofold higher than that of the control group, confirming the presence of insulin resistance in patients with vasospastic angina. The patients with vasospastic angina showed a significant increase in the average intima media thickness of the carotid wall and frequency of plaque formation, although they were comparable to the control subjects in risk factors other than insulin resistance. The intima media thickness was correlated with age (r = .62, P < .001), 2-hour insulin area (r = .45, P < .01), and steady-state plasma glucose level (r = .68, P < .0001) in patients with vasospastic angina. Similar correlations were observed in the control subjects. Multiple regression analyses of data indicated that 67% of the variation in the intima media thickness could be accounted for by age, steady-state plasma glucose level, and cigarette-years in vasospastic angina. In addition, differences in IMT were independently related to vasospastic angina. These results suggest that insulin resistance in association with compensatory hyperinsulinemia may be an important pathogenic factor for the development of coronary artery spasms and systemic early atherosclerosis.

Adult↗
PubMed1997

[Bilateral leg ulcers with pathologic evidence of small vessel vasculitis by skin biopsy during hydroxyurea therapy of chronic myelogenous leukemia].

We report a 45-year-old male with chronic myelogenous leukemia (CML) who experienced skin ulcers of the left lateral malleolus and dorsum of both feet. He had been treated with hydroxyurea (HU) for 2 years. His leg ulcers improved after HU was discontinued. Skin biopsy of the ulcerated lesion revealed that the lesion is compatible with small vessel vasculitis, but circulating immune complexes (C1q, anti-C3d antibody) were negative. Although the precise mechanism of the skin ulcer is unknown, we must take into consideration the skin changes were secondary to hydroxyurea therapy in myeloproliferative disorders.

Antineoplastic Agents↗