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Biomedical subjects

K Ando

Publications and source records attributed to K Ando.

At least 55 records · Page 3Linked to original sources
PubMed2001

A case of disseminated extrahepatic hepatocellular carcinoma after US-guided biopsy and percutaneous ethanol injection therapy.

A case of disseminated extrahepatic hepatocellular carcinoma (HCC) occurring after ultrasound (US)-guided biopsy and percutaneous ethanol injection therapy is presented. A 72-year-old man with hepatitis-C-virus-related cirrhosis underwent percutanous ethanol injection therapy (PEIT) two times with complete remission: the first for moderately-differentiated HCC in segment six (S6), and the second for well-differentiated HCC in another part of S6. Imaging studies including carbon dioxide (CO(2))-US angiography, incremental computed tomography, and dynamic magnet resonance imaging showed that both HCCs were hypovascular. Twenty-one months after the first PEIT and 7 months after the second, a 5.5x4.5 cm extrahepatic mass interfaced with S6 of the liver was detected by imaging studies. The patient underwent surgery for extrahepatic HCC. Grossly, the main tumor was 5.5x4.5 cm with capsule and septum; the disseminated tumors were detected on the surface of the liver, including the right diaphragm and the falx ligamentosa. Histologically, it was moderately- to poorly-differentiated HCC, which, although not attributed to direct track seeding, was suspected of being induced by the percutaneous US-guided biopsy procedure or by PEIT, irrespective of a hypovascular tumor. Further studies may provide insight into the risk factor engendered by these procedures.

Journal Article↗
PubMed2001

Effect of food reductones, 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF) and hydroxyhydroquinone (HHQ), on lipid peroxidation and type IV and I allergy responses of mouse.

The effect of long-term supplementation of food reductones, 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF) (2%, w/w), detected in many foodstuffs including soy sauce, and hydroxyhydroquinone (1,2,4-benzenetriol) (HHQ) (1.2%, w/w), detected in coffee, on mouse lipid peroxidation and type IV and I allergy responses was investigated. The effect of supplementation of these reductones combined with NO(2) inhalation (5-6 ppm) was also investigated. Levels of thiobarbituric acid-reactive substances in lung were remarkably increased, and those in kidney and liver were slightly decreased by supplementation of DMHF or HHQ. The degree of 2,4-dinitrochlorobenzene (DNCB)-sensitized lymph node cell proliferation as assessed by lymph node assay was remarkably enhanced by supplementation of DMHF or HHQ. Both the DNCB-sensitized and the trimellitic anhydride-sensitized increases in IgE levels of mice were enhanced to greater extent by supplementation of DMHF or HHQ. In no cases were additive effects of NO(2) inhalation observable. Allergen-sensitized type IV and I allergy responses of mice may be enhanced by supplementation of food reductones, DMHF or HHQ.

Animals↗
PubMed2001

Absence of a CD34- hematopoietic precursor population in recipients of CD34+ stem cell transplantation.

The purified CD34(+) cell fraction has been used for hematopoietic stem cell transplantation since they were demonstrated to have long-term reconstituting ability. Therefore, the potential effects of CD34(-) stem cells on the clinical course have been a major concern in recipients of CD34(+)-selected transplantation. To address this concern, we used an in vitro assay to determine whether transplant recipients have CD34(-)precursor population. Lin(-)CD34(-) cells were isolated from bone marrow cells in 11 transplant recipients including four CD34-selected transplantations, six standard bone marrow transplantations, and one T cell-depleted marrow transplantation. The frequency of the Lin(-)CD34(-) population in four CD34-enriched transplantation recipients was not different from those of normal donors or recipients of other modes of transplantation: 0.96 +/- 1.01% (mean +/- s.d., n = 4), 0.45 +/- 0.16% (n = 6), and 0.66 +/- 0.59% (n = 7), respectively. However, the Lin(-)CD34(-)population obtained from the recipients of CD34-enriched transplantation acquired neither CD34 expression nor colony-forming activity after 7 days of culture, whereas the cells from all the normal individuals and standard BMT recipients were able to differentiate into CD34(+) cells accompanied by the emergence of colony-forming activity.We conclude that recipients of CD34-enriched transplantation appear to have defects in their CD34(-) precursor population. The clinical significance of these defects will be determined in a life-long follow-up of these patients.

Adolescent↗
PubMed2001

A movable gestational sac in association with a myometrial defect.

An ultrasound examination in a woman at 9 weeks' gestation demonstrated a gestational sac with a live fetus in the left uterine horn which was surrounded by an extremely thin outer lining. An interstitial pregnancy was suspected and laparoscopy was performed. During laparoscopy the purple bulge in the left horn gradually reduced in size and eventually disappeared following the external pressure by the tip of the forceps. We believe this pressure caused contraction of the superficial myometrial fibers resulting in a shift in the location of the gestational sac to the central area of the uterus. The pregnancy continued and on Cesarean section at 34 weeks' gestation, a membranous protrusion of the uterine wall in the left horn was noticed. A myometrial defect caused by an intrauterine intervention in the patient's previous pregnancy was suspected to be the cause of this "movable gestational sac" phenomenon.

Adult↗
PubMed2001

Successful treatment with cyclosporin A for myelodysplastic syndrome with erythroid hypoplasia associated with T-cell receptor gene rearrangements.

Myelodysplastic syndrome (MDS) with erythroid hypoplasia, a rare form of MDS, has not yet been clearly defined. We report four patients with MDS with erythroid hypoplasia who received immunosuppressive therapy. All were elderly, had severe transfusion-dependent anaemia, morphological evidence of myelodysplasia and a low percentage (3.2-13.6%) of erythroid precursors. Administration of cyclosporin A (CsA) improved their anaemia; all transfusion-dependent patients achieved transfusion-independence. An inverted CD4/8 ratio was seen in three patients who also demonstrated T-cell receptor (TCR)-beta and -gamma gene rearrangements by Southern blotting and clonality by polymerase chain reaction. Treatment with CsA can be an attractive alternative treatment for patients with MDS with erythroid hypoplasia, which may be associated with a clonal abnormality in T cells.

Aged↗
PubMed2001

Angiotensin converting enzyme protects acetylcholine-induced relaxation from its attenuation by formyl-methionyl-leucyl-phenylalanine in rat aorta.

OBJECTIVE: A chemotactic tripeptide formyl-methionyl-leucyl-phenylalanine (fMLP) attenuated acetylcholine (ACh)-induced relaxation. Because angiotensin converting enzyme (ACE), which inactivates fMLP, is rich in vascular endothelial cells, we examined whether endothelial cell ACE inhibits the attenuating effect of fMLP on ACh-induced relaxation. DESIGN AND METHODS: ACh-induced relaxation was evaluated in aortic rings from 9-week-old Sprague-Dawley rats. We examined the effects of ACE, the ACE inhibitor captopril and/or fMLP on ACh-induced relaxation in aortas from rats with or without dexamethasone treatment, which enhances ACE activity. RESULTS: Pre-treatment with ACE did not alter ACh-induced relaxation in control aortas but abolished the inhibitory effect of fMLP on ACh-induced relaxation [maximal relaxation (Emax): 95.4 +/- 1.2 versus 75.5 +/- 1.9%, P < 0.05]. Conversely, captopril enhanced the attenuation of ACh-induced relaxation by fMLP (Emax: 62.5 +/- 3.3 versus 74.0 +/- 2.2%, P < 0.05), although captopril did not affect ACh-induced relaxation in control aortas. In addition, fMLP did not attenuate ACh-induced relaxation in aortas from dexamethasone-treated rats (Emax: 89.7 +/- 3.7 versus 85.2 +/- 3.8%, NS), which enhanced ACE activity of aortas (3.37 +/- 0.25 versus 2.70 +/- 0.20 IU/mg protein, P < 0.05). CONCLUSION: Endothelial-cell ACE attenuates the effect of fMLP on ACh-induced relaxation, possibly by its cleavage.

Acetylcholine↗
PubMed2001

Effects of ouabain on the growth and DNA synthesis of PC12 cells.

We investigated the effects of ouabain and serum from salt-loaded Dahl salt-sensitive (S) rats, which contain abundant ouabain-like compounds, on the growth and DNA synthesis of rat pheochromocytoma PC12 cells. Ouabain decreased the growth of PC12 cells, as evaluated by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay, in a concentration-dependent fashion. A moderate concentration (10(-7) M) of ouabain increased DNA synthesis, as measured by 5-bromo-2'-deoxyuridine incorporation, and induced transcription of the proto-oncogenes c-myc and c-fos. Serum from salt-loaded Dahl S rats also enhanced DNA synthesis, but serum from Dahl salt-resistant rats did not. Thus ouabain-like compounds may modify the growth or differentiation of neural tissues. This effect may contribute to the development of salt-induced hypertension in Dahl S rats.

Animals↗
PubMed2001

Enhanced expression and release of C-type natriuretic peptide in freshwater eels.

C-type natriuretic peptide (CNP) is recognized as a paracrine factor acting locally in the brain and periphery. To assess the role of CNP in teleost fish, a cDNA encoding a CNP precursor was initially cloned from the eel brain. CNP message subsequently detected by ribonuclease protection assay, using the cDNA as probe, was most abundant in the brain followed by liver, gut, gills, and heart. Expression was generally higher in freshwater (FW) than in seawater (SW) eels, but not in the brain. Plasma CNP concentration measured by a newly developed homologous radioimmunoassay for eel CNP was higher in FW than in SW eels. The CNP concentration was also higher in the heart of FW eels but not in the brain. These results show that CNP is abundantly synthesized in peripheral tissues of FW eels and secreted constitutively into the circulation. Therefore, CNP is a circulating hormone as well as a paracrine factor in eels. Together with our previous demonstration that CNP-specific receptor expression is enhanced in FW eels, it appears that CNP is a hormone important for FW adaptation. Because atrial NP (ANP) promotes SW adaptation in eels, CNP and ANP, despite high sequence identity, appear to have opposite effects on environmental adaptation of the euryhaline fish.

Amino Acid Sequence↗
PubMed2001

Expression of SR-PSOX, a novel cell-surface scavenger receptor for phosphatidylserine and oxidized LDL in human atherosclerotic lesions.

Receptor-mediated endocytosis of oxidized low density lipoprotein (Ox-LDL) by macrophages and the subsequent foam cell transformation in the arterial intima are key events in early atherogenesis. Recently, we have identified a novel macrophage cell-surface receptor for Ox-LDL by expression cloning from a cDNA library of phorbol 12-myristate 13-acetate-stimulated THP-1 cells, designated as the scavenger receptor for phosphatidylserine and oxidized lipoprotein (SR-PSOX). Here, we examined SR-PSOX expression in human atherosclerotic lesions. Total cellular RNA and fresh frozen sections were prepared from human carotid endarterectomy specimens (from 21 patients) and directional coronary atherectomy specimens (from 11 patients). Fragments of human aortas of 2 patients without visible atherosclerotic lesions served as negative controls. Quantitative reverse transcription-polymerase chain reaction demonstrated that SR-PSOX mRNA expression was prominent in atherosclerotic lesions but undetectable in normal aortas. Immunohistochemistry showed that SR-PSOX was predominantly expressed by lipid-laden macrophages in the intima of atherosclerotic plaques in carotid endarterectomy and directional coronary atherectomy specimens, although its expression was not detectable in normal arterial wall. Double-labeled immunohistochemistry confirmed that SR-PSOX is expressed by intimal macrophages. Taken together, SR-PSOX may be involved in Ox-LDL uptake and subsequent foam cell transformation in macrophages in vivo and thus may play important roles in human atherosclerotic lesion formation.

Animals↗
PubMed2001

Adenylate cyclase/protein kinase A signaling pathway enhances angiogenesis through induction of vascular endothelial growth factor in vivo.

We previously reported that endogenous prostaglandins (PGs) may increase cAMP facilitated angiogenesis through the induction of vascular endothelial growth factor (VEGF) in rat sponge implantation models. In the present experiment, we tested whether or not adenylate cyclase / protein kinase A (AC/PKA)-dependent VEGF induction enhanced angiogenesis in this model. Topical daily injections of 8-bromo-cAMP enhanced angiogenesis in a dose-dependent manner. Forskolin, an activator of AC, also facilitated angiogenesis as did amrinone, an inhibitor of phosphodiesterase. VEGF induction was confirmed by the increased levels in the fluids in the sponge matrix after topical injection of 8-bromo-cAMP. Immunohistochemical investigation further revealed the VEGF-expressed cells in the sponge granulation tissues to be fibroblasts, and the intensity of positive reactions was enhanced by 8-bromo-cAMP, forskolin and amrinone. Angiogenesis without topical injections of the above compounds was suppressed by SQ22,536, an inhibitor for AC, or H-89, an inhibitor for PKA, with concomitant reductions in VEGF levels. Daily topical injections of neutralizing antibody or anti-sense oligonucleotide against VEGF significantly suppressed angiogenesis. PGE2-induced angiogenesis was suppressed with SQ22,536 or H-89. These results suggested that AC/PKA-dependent induction of VEGF certainly enhanced angiogenesis and that pharmacological tools for controlling this signaling pathway may be able to facilitate the management of conditions involving angiogenesis.

Adenine↗
PubMed2001

Performance of a partially packed charcoal pellet bioreactor for acetic acid fermentation.

The performance of a partially packed charcoal pellet bioreactor was compared to that of a fully packed bioreactor for aerobic acetic acid production. In the fully packed charcoal pellet bioreactor, it was considered that the shortening of an actual retention time of the culture broth limited the bioreactor performance under high dilution rate and high aeration conditions. By reducing the filling ratio of charcoal pellets to 44%, which increased the actual retention time of the culture broth, the maximum productivity increased from 3.9 g/l/h in the fully packed bed bioreactor to 5.7 g/l/h in the partially packed bioreactor without affecting the operational stability.

Journal Article↗
PubMed2001

Time course of reoxygenation in experimental murine tumors after carbon-beam and X-ray irradiation.

We compared the tumor reoxygenation patterns in three different murine tumor cell lines after X-irradiation with those after carbon-beam irradiation using a heavy-ion medical accelerator (HIMAC) system. The tumors of the cell lines SCCVII, SCCVII-variant-1 and EMT6 on the hind legs of mice received local priming irradiation with a carbon-beam (8 Gy, 73 keV/microm in LET, 290 MeV/u, 6 cm SOBP) or X-rays (13 Gy, 250 kVp). After various intervals, the mice were given whole-body test irradiation (16 Gy. 250 kVp X-ray) either in air or after they were killed. The hypoxic fractions were estimated as the proportions of the surviving fractions of the tumors in killed mice to those in air-breathing mice. In the SCCVII tumors, the hypoxic fractions at 0.5 h were 50% and 21% (p < 0.05) after the priming X-irradiation and carbon-beam irradiation, respectively. In the SCCVII-variant-1 tumors, the hypoxic fractions were 85% and 82% at 0.5 h, 84% and 20% at 12 h (p < 0.01), and 21% and 31% at 24 h after X-ray and after carbon-beam irradiation, respectively. In the EMT6 tumors, the reoxygenation patterns after X-irradiation and carbon-beam irradiation were quite similar. We concluded that the reoxygenation pattern differed among the three tumor cell lines, and that reoxygenation tended to occur more rapidly after carbon-beam irradiation than after X-irradiation for SCCVII and SCCVII-variant-1 tumors.

Animals↗
PubMed2001

Relative biological effectiveness of the 235 MeV proton beams at the National Cancer Center Hospital East.

A therapy-dedicated cyclotron was installed in the National Cancer Center Hospital East (NCCHE) at Kashiwa in 1997. Prior to the start of clinical use, we investigated the biological effectiveness of therapeutic proton beams for cell lethality. The proton beams accelerated up to 235 MeV were horizontally extracted from the cyclotron, and scattered by a bar-ridge filter to produce a Spread-Out-Bragg-Peak (SOBP) of 10-cm width. The biological systems used here were mouse intestinal crypt cells and three in vitro cell lines, including SCC61 human squamous cell carcinoma, NB1RGB human fibroblasts and V79 Chinese hamster cells. The dose responses after irradiation at either the entrance plateau or the middle portion of SOBP were compared with those after linac 6 MV X-ray irradiation. The fit of a linear quadratic model to survival curves showed that proton irradiation increased the alpha value of SCC61 and the beta value of V79 cells with a least change for alpha/beta ratio of NB1RGB cells. The isoeffect dose that reduces either cell survivals to 10% or mouse jejunum crypts to 10 per circumference was termed D10. The relative biological effectiveness (RBE) of protons obtained by comparing the D10 values between protons and X-rays ranged from 0.9 to 1.2. The depth distribution of cell lethality was measured by replating V79 cells after irradiation from a "cell stack chamber" that received a single dose of 7 Gy at the middle position of SOBP. The thus-obtained cell survivals at various depths coincided well with the estimated survivals, but tended to decrease at the distal end of SOBP. We conclude that an RBE of 1.1 would be appropriate for 235 MeV proton beams at the NCCHE.

Animals↗
PubMed2001

Depressive mood accompanies hypercholesterolemia in young Japanese adults.

Screening of young hypercholesterolemics is important because they are highly susceptible to atherosclerotic diseases. However, in some cases, serum cholesterol level may be elevated temporarily due to stress or other psychological factors. This study examined the effects of mood states on 'persistent' hypercholesterolemia in comparison with 'temporary' hypercholesterolemia among students entering a university. The subjects were 114 untreated first-year students aged 18 to 20 years old. All had been screened positive for hypercholesterolemia (serum total cholesterol > or = 220 mg/dl) upon enrolling in the university. Three months after the screening, they were divided into two groups according to the re-examined serum total cholesterol level; a persistent hypercholesterolemic group (n=41) with >220 mg/dl and a temporary hypercholesterolemic group (n=73) with <220 mg/dl. At that time, they completed the Profile of Mood States (POMS) with tension-anxiety, depression, anger-hostility, vigor, fatigue and confusion scales. The POMS depression scores and the female ratio were higher (both p<0.01) and body mass index was lower (p<0.05) in the persistent hypercholesterolemic subjects than in the temporary hypercholesterolemic subjects; the POMS depression scores were still higher (p<0.05) after controlling for the effects of gender, body mass index, and other POMS scales by multiple logistic regression analysis. Depressive mood appeared to relate to hypercholesterolemia when the university students were screened. Assessment of mood states may be important in screening young hypercholesterolemic patients.

Adolescent↗
PubMed2001

Five cases of Diphyllobothrium nihonkaiense infection with discovery of plerocercoids from an infective source, Oncorhynchus masou ishikawae.

Five persons from 2 families residing at Miyama Town, Mie Prefecture, Japan, ingested fresh raw fish Oncorhynchus sp. on 9 May 1999 that was caught at Owase district in Mie. They all expelled diphyllobothriid cestodes 11-37 days after ingesting the fish. The parasites were morphologically identical to Diphyllobothrium nihonkaiense Yamane et al., 1986. Five plerocercoids were detected from a portion of the fish. Nucleotide sequence of a region of the cytochrome c oxidase subunit I gene of mitochondrial DNA from an adult worm was identical with that from the plerocercoid. The fish was identified as Oncorhynchus masou ishikawae according to the nucleotide sequence of the nuclear ribosomal second internal transcribed spacer region II gene. This is the first record of D. nihonkaiense plerocercoids from O. m. ishikawae.

Adolescent↗
PubMed2001

Insulin resistance with enhanced insulin signaling in high-salt diet-fed rats.

Previous clinical studies showed an apparent correlation between hypertension and insulin resistance, and patients with diabetes are known to have increased blood pressure responsiveness to salt loading. To investigate the effect of high salt intake on insulin sensitivity and the insulin signaling pathway, a high-salt diet (8% NaCl) or a normal diet was given to 7-week-old SD rats for 2 weeks. High salt-fed rats developed slightly but significantly higher systolic blood pressure than controls (133 +/- 2 vs. 117 +/- 2 mmHg, P < 0.001), with no change in food intake or body weight. High salt-fed rats were slightly hyperglycemic (108.5 +/- 2.8 vs. 97.8 +/- 2.5 mg/dl, P = 0.01) and slightly hyperinsulinemic (0.86 +/- 0.07 vs. 0.61 +/- 0.06 ng/ml, P = 0.026) in the fasting condition, as compared with controls. Hyperinsulinemic-euglycemic clamp study revealed a 52.7% decrease in the glucose infusion rate and a 196% increase in hepatic glucose production in high salt-fed rats, which also showed a 66.4% decrease in 2-deoxyglucose uptake into isolated skeletal muscle and a 44.5% decrease in insulin-induced glycogen synthase activation in liver, as compared with controls. Interestingly, despite the presence of insulin resistance, high salt-fed rats showed enhanced insulin-induced tyrosine phosphorylation of insulin receptor substrate (IRS)-1, IRS-2 (liver and muscle), and IRS-3 (liver only). Phosphatidylinositol (PI) 3-kinase activities associated with IRS and phosphotyrosine in the insulin-stimulated condition increased 2.1- to 4.1-fold, as compared with controls. Insulin-induced phosphorylation of Ser-473 of Akt and Ser-21 of glycogen synthase kinase-3 also increased 2.9- and 2-fold, respectively, in the liver of the high salt-fed rats. Therefore, in both the liver and muscle of high salt-fed rats, intracellular insulin signaling leading to PI 3-kinase activation is enhanced and insulin action is attenuated. The hyperinsulinemic-euglycemic clamp study showed that decreased insulin sensitivity induced with a high-salt diet was not reversed by administration of pioglitazone. The following can be concluded: 1) a high-salt diet may be a factor promoting insulin resistance, 2) the insulin-signaling step impaired by high salt intake is likely to be downstream from PI 3-kinase or Akt activation, and 3) this unique insulin resistance mechanism may contribute to the development of diabetes in patients with hypertension.

Animals↗
PubMed2001

Impaired telomere regulation mechanism by TRF1 (telomere-binding protein), but not TRF2 expression, in acute leukemia cells.

Telomere regulation is suggested to be an important mechanism in cellular proliferation and cellular senescence not only in normal diploid cells but also in neoplastic cells, including human leukemia cells. We studied the possible correlation among telomere length, telomerase (a ribonuclear protein that synthesizes the telemeres de novo) activity, hTERT (a catalytic subunit of telomerase) expression, and TRF1 and TRF2 (telomere DNA binding proteins) expression in human acute leukemia cells. The hTERT expression level was strongly associated with telomerase activity (P=0.0001), indicating that the expression level of the catalytic subunit (hTERT) regulates telomerase activity in human acute leukemia cells. TRF1 expression, which is believed to control telomere length, was significantly elevated in patients with acute lymphoblastic leukemia (ALL) (P=0.0232) compared to those in acute myeloid leukemia (AML); TRF1 expression tended to be higher in patients without telomere shortening (P=0.077) and in those with hTERT expression (P=0.055). This indicates that TRF1 may act to monitor telomere length under the condition of up-regulated telomerase activity in some neoplastic cells. In contrast, TRF2 expression in acute leukemia did not show any correlation with telomere parameters in this study. Although the precise regulation mechanism of telomere length is still uncertain, these results may suggest that regulation of telomere length is partially associated with TRF1 expression, whereas dysfunction of TRF1 expression may be speculated in a subset of acute leukemia.

Adolescent↗