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K Fukuchi

Publications and source records attributed to K Fukuchi.

At least 37 records · Page 2Linked to original sources
PubMed2001

Analysis of c-myc DNA amplification in non-small cell lung carcinoma in comparison with small cell lung carcinoma using polymerase chain reaction.

Previous studies of c-mvc DNA amplification in lung cancer have focused primarily on analysis of small cell carcinoma or its tumor cell lines. There are few data about c-myc DNA amplification in histological types of lung cancer other than small cell carcinoma. Therefore the present study was conducted to investigate c-myc oncogene amplification in non-small cell lung carcinoma. We studied 46 lung tumor specimens for c-myc DNA amplification (15 adenocarcinomas, 15 squamous cell carcinomas, 6 large cell carcinomas, and 10 small cell carcinomas). Polymerase chain reaction, digoxigenin DNA labeling, and electrophoresis were utilized to investigate the c-myc copy number in the lung tumor specimens. The c-myc copy number of non-small cell carcinoma ranged from 1.5 to more than 20.0 in adenocarcinoma and squamous cell carcinoma, and from 6.0 to 12.0 in large cell carcinoma. That of small cell carcinoma ranged from 1.8 to 12.0. The c-myc copy number of non-small cell carcinoma was significantly higher than that of small cell carcinoma (Wilcoxon rank sum test, Z=2.06 P=0.040). However, the differences in c-myc copy number among these four histological types were not statistically significant. Amplification of c-myc (more than 4 copies) was observed not only in small cell carcinoma but also in nonsmall cell carcinoma at similarly high frequency (12/15 in adenocarcinoma and squamous cell carcinoma, 6/6 in large cell carcinoma, and 9/10 in small cell carcinoma).

Adenocarcinoma↗
PubMed2001

Embolic distribution through patent foramen ovale demonstrated by (99m)Tc-MAA brain SPECT after Valsalva radionuclide venography.

UNLABELLED: Cryptogenic stroke might relate to paradoxical embolism stemming from right-to-left shunt caused by patent foramen ovale (PFO). We performed radionuclide venography using the Valsalva maneuver, followed by (99m)Tc-macroaggregated albumin (MAA) brain SPECT to investigate the fate of emboli originating from the lower extremities. METHODS: Ten patients (9 men, 1 woman; mean age, 61 +/- 17 y) with PFO underwent radionuclide venography with and without the Valsalva maneuver on the whole-body image, followed by brain SPECT with (99m)Tc-MAA to determine the cortical uptake that would detect right-to-left shunt. After counts in each region of interest (ROI) were normalized by comparison with the averaged count, the distribution of MAA was compared with that of (99m)Tc-hexamethyl-propyleneamine oxime (HMPAO) brain SPECT by drawing ROIs on frontal, temporoparietal (anterior circulation territory), occipital, and cerebellar areas (posterior circulation territory). RESULTS: The thyroid on the whole-body scan was visualized after the Valsalva maneuver in 2 of the 10 patients. In 7 of 10 patients, 56 ROIs in the visualized cortical uptake showed that the distribution of MAA correlated well with that of HMPAO according to the equation: HMPAO = -71.21 + 1.71 x MAA, (r = 0.575, P < 0.01). The excess difference in the relative counts in the posterior over anterior circulation territory was 5.6% and 16.1% of the HMPAO and MAA values, respectively. CONCLUSION: Brain SPECT with (99m)Tc-MAA was more sensitive than thyroid visualization in detecting right-to-left shunt. The excess flow in the posterior cerebral circulation indicated an increased likelihood of cerebral emboli originating from the lower extremities and indicated that the flow difference between HMPAO and MAA probably resulted from poor linearization of HMPAO in the high-flow area.

Adult↗
PubMed2001

Clinical analysis of myocardial perfusion and metabolism in patients with hypertrophic cardiomyopathy by single photon emission tomography and positron emission tomography.

BACKGROUND AND OBJECTIVES: Changes in myocardial energy metabolism and their relation to coronary flow reserve in hypertrophic cardiomyopathy were assessed by myocardial fatty acid imaging with iodine-123 beta-methyliodophenyl pentadecanoic acid single photon emission tomography (123I-BMIPP SPECT) (fasting), glucose imaging with fluorine-18 fluorodeoxyglucose positron emission tomography (18F-FDG PET) (fasting), and perfusion imaging with nitrogen-13 (13N)-ammonia PET (dipyridamole-stress and at rest) in adult patients with hypertrophic cardiomyopathy and with asymmetric septal hypertrophy. RESULTS: 123I-BMIPP defects mismatched with thallium-201 (201Tl) uptake were often observed in the hypertrophic septal regions indicating reduced fatty acid utilization incidence of 59% (22/37). 18F-FDG images showed diffusely increased uptake in most of the patients (73%, 27/37), but showed regionally increased 18F-FDG uptake at the septal regions in only two patients. Study of 18 hypertrophic cardiomyopathy patients with the mismatched 123I-BMIPP defects found that the severity of the defects correlated with reduced coronary flow reserve determined by the 13N-ammonia PET study. On the other hand, changes in 18F-FDG images were not related to those in coronary flow reserve. CONCLUSIONS: These results suggest that the mismatched 123I-BMIPP defects, which indicate abnormality in myocardial fatty acid metabolism, occur under reduced coronary flow reserve, and may contribute to the prediction of progressive myocardial failure in patients with hypertrophic cardiomyopathy. The significance of 18F-FDG in patients with hypertrophic cardiomyopathy is still uncertain.

Adult↗
PubMed2001

[Hepatitis C virus genotyping by restriction fragment length polymorphism of polymerase chain reaction products generated with a HCV detection kit].

Highly conserved sequence in the 5' untranslated region(UTR) of hepatitis C virus(HCV) genome have been targeted by most nucleic acid amplification-based detection assays, such as Amplicor HCV test, a commercially available assay kit. In this study, we classified HCV genotypes by direct sequencing determination for 5' UTR of nested-PCR after Amplicor HCV test. Then, based on the results of sequence, RFLP analysis after digestion of the nested PCR fragments with Hae III or Sau 3AI to classify HCV genotype was evaluated. RFLP analysis distinguished the type 1, 2a and 2b. Only one of 29 samples was not classified by RFLP analysis due to the point mutation of Hae III recognition site. HCV genotypes commonly found in JAPAN were classified into three types, 1b, 2a, and 2b. Also, RFLP analysis requires fewer resources than serotype grouping test. Hence, the present method provides an adaptable and rapid HCV genotyping in clinical laboratory in JAPAN.

Base Sequence↗
PubMed2000

Levels of DNA damage are unaltered in mice overexpressing human catalase in nuclei.

Two types of transgenic mice were generated to evaluate the role of hydrogen peroxide in the formation of nuclear DNA damage. One set of lines overexpresses wild-type human catalase cDNA, which is localized to peroxisomes. The other set overexpresses a human catalase construct that is targeted to the nucleus. Expression of the wild-type human catalase transgene was found in liver, kidney, skeletal muscle, heart, spleen, and brain with muscle and heart exhibiting the highest levels. Animals containing the nuclear-targeted construct had a similar pattern of expression with the highest levels in muscle and heart, but with lower levels in liver and spleen. In these animals, immunofluorescence detected catalase present in the nuclei of kidney, muscle, heart, and brain. Both types of transgenic animals had significant increases of catalase activities compared to littermate controls in most tissues examined. Despite enhanced activities of catalase, and its presence in the nucleus, there were no changes in levels of 8OHdG, a marker of oxidative damage to DNA. Nor were there differences in mutant frequencies at a Lac Z reporter transgene. This result suggests that in vivo levels of H(2)O(2) may not generate 8OHdG or other types of DNA damage. Alternatively, antioxidant defenses may be optimized such that additional catalase is unable to further protect nuclear DNA against oxidative damage.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2000

Phosphatidylinositol 3-kinase inhibitors, Wortmannin or LY294002, inhibited accumulation of p21 protein after gamma-irradiation by stabilization of the protein.

Expression of the cyclin kinase inhibitor, p21, is regulated both transcriptionally and posttranscriptionally by the ubiquitin-proteasome degradation pathway. Recently, we reported that DNA damage is required for efficient p21 expression by demonstrating that enhanced p21 mRNA expression induced by DNA damage results in increased p21 protein, but enhanced p21 mRNA without DNA damage does not. In addition, we demonstrated that DNA damage suppressed the ubiquitination of p21. In this study, we analyze the link between p21 stabilization and DNA damage. Enhanced p21 protein expression in ML-1 cells resulting from 15 Gy gamma-irradiation was diminished by Wortmannin or LY294002 pretreatment of cells. However, the levels of p21 mRNA were not affected by inhibitor pretreatment. Wortmannin or LY294002 pretreatment reduces p53 expression after gamma-irradiation to a lesser degree than that of p21. In addition, we examined the involvement of DNA-PK, whose activity is inhibited by Wortmannin or LY294002, in p21 stabilization using the SCID fibroblast cell line and a DNA-PK targeting ML-1 cell line. Accumulation of p21 protein by gamma-irradiation was similar to that of DNA-PK intact cells and was reduced by Wortmannin or LY294002 pretreatment. Involvement of another DNA damage detecting enzyme, the ATM gene product, whose activity is also inhibited by Wortmannin or LY294002, was evaluated. ATM deficient cells induced p21 after gamma-irradiation, gamma-irradiation-induced p21 protein was diminished by pretreatment of cells with Wortmannin or LY294002. We conclude that the p21 stabilization mechanism functions after gamma-irradiation, was sensitive to Wortmannin or LY294002, and required neither DNA-PK nor ATM gene product for activity.

3T3 Cells↗
PubMed2000

Overexpression of wild-type and nuclear-targeted catalase modulates resistance to oxidative stress but does not alter spontaneous mutant frequencies at APRT.

Animal cells generate hydrogen peroxide as a byproduct of energy metabolism. In the presence of reduced metals H(2)O(2) can decompose to a highly reactive hydroxyl radical that attacks essentially all organic molecules, including DNA. We wished to determine if overexpression of catalase and/or the targeting of the enzyme to the nucleus could protect cells from oxidative stress and reduce the frequency of mutation. Wild-type human catalase, which localizes to peroxisomes, and a modified construct, which targets catalase to the nucleus, were overexpressed in a murine line of embryonic carcinoma cells (P19). Both constructs enhanced the resistance of the cells to hydrogen peroxide, but sensitized them to bleomycin. Overexpression of wild-type catalase protected cells against paraquat, while nuclear targeting sensitized them to this agent. Expression of neither construct significantly altered spontaneous mutant frequencies at the endogenous murine adenosine phosphoribosyl transferase (APRT) locus; however, nuclear-targeted catalase prevented an increase in mutant frequency after H(2)O(2) treatment. These results suggest that endogenous levels of hydrogen peroxide may not generate DNA damage in vivo, or that such damage may be efficiently repaired in murine embryonic carcinoma cells.

Adenine Phosphoribosyltransferase↗
PubMed2000

Hemodynamic and metabolic state of hyperfixation with 99mTc-HMPAO brain SPECT in subacute stroke.

By means of positron emission tomography (PET), we investigated the hemodynamic and metabolic state of the hyperfixation identified as the increased accumulation with 99mTc-d,l-hexamethylpropyleneamine oxime (HMPAO) by single photon emission computed tomography (SPECT) in patients with subacute stroke. We studied four patients with subacute stroke having hyperfixed areas evaluated with CBF, CMRO2, OEF and CBV by PET. The hyperfixation rate with 99mTc-HMPAO was obtained by comparing the surplus rate with standardized CBF. The OEF and CMRO2 values in the hyperfixed areas of 4 patients were significantly lower than those in normal 5 controls (p < 0.01), but CBF and CBV were almost the same in patients and normal controls, but the hyperfixation rate of 0.30 +/- 0.15 in 4 patients correlated well with CBV (r = 0.97, y = 11.75x + 0.42; p < 0.05). Hyperfixation with 99mTc-HMPAO in the infarct area revealing a mismatch between CMRO2 and CBF meant relative luxury perfusion. The hyperfixation rate determined by 99mTc-HMPAO brain SPECT correlated with CBV in the PET study. We can conclude that one of the main factors which caused hyperfixation was vasodilatation as well as the blood brain barrier disruption and the neovascularization.

Adult↗
PubMed2000

Estimation of the area at risk in myocardial infarction of rats by means of I-123 beta-methyliodophenyl pentadecanoic acid imaging.

Clinical investigations have suggested that the defects in SPECT images of a free fatty acid analog, I-123 beta-methyliodophenyl pentadecanoic acid (BMIPP) may indicate the ischemic risk area. To elucidate whether I-123 BMIPP can indicate the area at risk of ischemia, ex-vivo autoradiography was performed in rats whose left coronary artery was occluded for 60 min and then reperfused. I-123 BMIPP was injected at the acute stage (n = 10), or the subacute stage (7 days after reperfusion; n = 9). Infarction and the area at risk were identified by triphenyl tetrazolium chloride staining and injection of methylene blue during religation just before sacrifice, respectively. The BMIPP uptake in the risk area was significantly lower than that in the remote area at the acute (risk, 53.7+/-23.3% of the uptake at right ventricle, mean +/- SD; remote, 109.3+/-11.8%; p < 0.01) and subacute (risk, 52.5+/-11.5%; remote, 97.9+/-14.3%; p < 0.01) stages. In addition, the area with reduced uptake of I-123 BMIPP showed a significant correlation with the area at risk both at the acute (r = 0.98, p < 0.01) and subacute (r = 0.92, p < 0.01) stages. In conclusion, the area at risk can be evaluated by I-123 BMIPP both at the acute and subacute stages.

Animals↗
PubMed2000

Changes in perfusion and fatty acid metabolism of rat heart with autoimmune myocarditis.

To elucidate the change in perfusion and aerobic metabolism in myocarditis, tissue counting and dual tracer ex vivo autoradiography with Tl-201 and a free fatty acid analog, I-123- or I-125-labeled (p-iodophenyl)-methyl-pentadecanoic acid (BMIPP), were performed in rats with myocarditis induced by immunization with cardiac myosin. Inflammatory damage was classified histologically. At the acute stage (2-4 weeks after the antigen-injection), total heart uptakes of Tl and BMIPP and the ratio (BMIPP/Tl) were significantly reduced in myocarditis rats (N = 15) compared with the controls (N = 12). Myocardial distribution of Tl and BMIPP was not homogeneous. Relative uptake of Tl and BMIPP (N = 9, 128 regions) was gradually decreased with the extent of inflammation, and the regional BMIPP/Tl was smaller than the control. At the subacute stage (7 weeks after the antigen-injection), total Tl uptake in myocarditis rats (N = 5) recovered to the control level (N = 4), but that of BMIPP was still significantly lower than the control. BMIPP/Tl was still significantly lower in myocarditis. Myocardial distribution of Tl and BMIPP recovered to be more homogeneous. Relative uptake of Tl and BMIPP (N = 6, 78 regions) still gradually but significantly decreased with the extent of inflammation. Regional BMIPP/Tl was still depressed in myocarditis. These results indicate that myocardial perfusion and aerobic metabolism were discrepant and heterogeneously suppressed with severe inflammation during the acute stages, but the difference decreases with time. Examination with Tl-201 and BMIPP may provide information about the severity of myocarditis.

Animals↗
PubMed2000

Detection of coronary artery disease by iodine-123-labeled iodophenyl-9-methyl pentadecanoic acid SPECT: comparison with thallium-201 and iodine-123 BMIPP SPECT.

To evaluate the ability to detect coronary artery disease (CAD) with a new iodine-123 labeled branched fatty acid analog, iodophenyl-9-methyl pentadecanoic acid (9MPA), we performed 9MPA, iodine-123 BMIPP and thallium-201 SPECT in patients with CAD. Twenty-four patients (11 with effort angina and 13 with myocardial infarction) were studied. In all patients, 9MPA SPECT was obtained at 15 min after injection. Twenty-three patients underwent stress-redistribution 201Tl SPECT and 9 patients also underwent BMIPP myocardial fatty acid imaging. The regional uptakes of 9MPA, BMIPP and 201Tl were scored semiquantitatively and the segmental agreements were compared among them. In the segment-to-segment comparison, 9MPA showed reduced activity in comparison to stress-redistribution 201Tl imaging. The defect score of 9MPA was significantly greater than that of redistribution 201Tl images (p < 0.001). In addition, segmental 9MPA uptake was lower than BMIPP and its defect score was significantly greater than that of BMIPP (p < 0.05). When coronary angiography was used as the criterion, 9MPA showed higher sensitivity and lower specificity than stress-redistribution 201Tl (p < 0.01). In conclusion, fatty acid metabolic imaging with 9MPA is a sensitive but nonspecific detector of CAD.

Angina Pectoris↗
PubMed2000

Accumulation of amyloid-beta protein in exocrine glands of transgenic mice overexpressing a carboxyl terminal portion of amyloid protein precursor.

Amyloid-beta protein (Abeta) and its precursor (betaPP) play important roles in the pathogenesis of Alzheimer disease and inclusion-body myositis. In humans, Abeta deposits are found in brain, skeletal muscle, and skin. Therefore, we have investigated possible Abeta deposits in multiple tissues of two transgenic mouse lines overexpressing the signal plus Abeta-bearing 99-amino acid carboxyl terminal sequences of betaPP under the control of a cytomegalovirus enhancer/beta-actin promoter. One of the lines developed Abeta-immunoreactive intracellular deposits consistently in the pancreas and lacrimal gland, and occasionally in gastric, DeSteno's, and lingual glands. Although the Abeta deposits increased during ageing and degenerative changes of the tissues were observed, little or no extracellular Abeta deposits were observed up to the age of 25 months. These lines of transgenic mice are useful for studying the molecular mechanisms of development and clearance of intracellular Abeta deposits.

Aging↗
PubMed2000

Molecular basis of clarithromycin-resistance in Mycobacterium avium intracellulare complex.

Nucleotide sequences of domain V and domain II regions of the 23S rRNA gene were determined in both in vitro-made mutants and clinical isolates of Mycobacterium avium and M. intracellulare conferring clarithromycin-resistance. All laboratory-made mutants showed high level resistance to clarithromycin (> 150 micrograms ml-1) and mutation at position 2058 (cognate with Escherichia coli base) in domain V region. In the clinical isolates, while the susceptible ones had no mutation in domain V, the resistant strains showed mutation at 2058 or 2059. Six isolates with low level of resistance exhibited no mutation in domain V. All strains tested had no mutation in domain II region. These results suggested that most of the resistance arose from the mutation in domain V of the 23S rRNA gene, but other unknown mechanisms evidently exist in mycobacteria.

Anti-Bacterial Agents↗
PubMed2000

Heterodimerization of Bcl-2 and Bcl-X(L) with Bax and Bad in colorectal cancer.

The rate of cell loss owing to apoptosis is mediated by competitive dimerization with selective pairs of cell death antagonists (Bcl-2, Bcl-X(L)) and agonists (Bax, Bad). The aim of this study was to investigate which Bcl-2 family dimers had a critical factor in colorectal cancer. We analyzed the expression of Bcl-2, Bcl-X(L), Bax, and Bad in normal-appearing mucosa and colorectal tumor tissues by Western blotting after immunoprecipitation. Compared with the ratio of Bax-Bcl-2/total Bax in normal mucosa, the ratio was significantly reduced in tumors (p = 0.02). In this series, the low ratio of Bad-Bcl-2/total Bcl-2 was associated with advanced tumor stages (p = 0.02). A reduced heterodimerization of Bax with Bcl-2 may contribute to the development of colorectal cancer. The heterodimerization of Bad with Bcl-2 may be repressed in advanced tumor tissues, and may contribute to tumor growth in colorectal cancer.

Adult↗
PubMed2000

Brain fluorine-18 fluorodeoxyglucose imaging with dual-head coincidence gamma camera: comparison with dedicated ring-detector positron emission tomography.

BACKGROUND AND PURPOSE: Dual-head coincidence gamma camera (DHC) imaging has been proposed as an alternative to dedicated ring-detector positron emission tomography (dr-PET) for clinical fluorodeoxyglucose (FDG) studies. The purpose of this investigation was to assess the quality of DHC images in FDG studies of the human brain. METHODS: Seven healthy volunteers and 12 patients with various cerebral disorders underwent consecutive brain dr-PET and DHC with FDG. All sets of images were compared semiquantitatively using regions of interest. RESULTS: Cortical count ratios to the cerebellum on DHC and dr-PET images did not differ significantly among the volunteers, except in the superior frontal cortex and thalamus. In all studies including those of cerebral disorders, the mean cortical-to-cerebellar ratios of DHC and dr-PET images correlated closely. CONCLUSION: FDG imaging with DHC delineated the metabolic distribution of glucose in the brain as well as dr-PET did, except in the superior frontal cortex and thalamus. Therefore, DHC may be a dedicated cost-effective means of detecting metabolic abnormalities in the brain.

Adult↗