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Biomedical subjects

M Nakano

Publications and source records attributed to M Nakano.

At least 37 records · Page 2Linked to original sources
PubMed2004

Milk and milk products consumption in relationship to serum lipid levels: a community-based study of middle-aged and older population in Japan.

The authors examined the association of milk and milk products consumption (MMPC) with serum lipid profiles including total cholesterol (TC), triacylglycerols (TG), HDL cholesterol (HDLC), LDL cholesterol (LDLC), and TC/HDLC ratio in a community-based sample. The study population comprised 461 men and 834 women aged 40-79 years who, in 2001, participated in an annual healthy examination and a lifestyle related survey Consumption frequency of 17 foods, including milk and milk products, was determined by a self-administered questionnaire. The participants were asked by "Do you drink cow's milk or eat milk products such as yoghurt and cheese everyday?", and two groups ("Yes" and "No") of MMPC were classified. Multiple linear regression analyses were conducted to examine the relationships between MMPC and 5 serum lipid profile levels adjusted for sex, age, body mass index (BMI), alcohol consumption, smoking, physical activity, and fat intake. Univariate and multivariate analyses indicated inverse associations of MMPC with TC, HDLC, and LDLC, and that the "Yes" group had higher adjusted means of serum TC by 7.133 mg/100 ml (p < 0.001), HDLC by 1.844 mg/100 ml (p < 0.05), LDLC by 5.459 mg/100 ml (p < 0.001). We suggested that MMPC has an association with serum lipid and lipoprotein levels and that MMPC may have an unfavorable effect on hypercholesterolaemia in the Japanese population.

Adult↗
PubMed2004

Regeneration of coenzyme Q9 redox state and inhibition of oxidative stress by Rooibos tea (Aspalathus linearis) administration in carbon tetrachloride liver damage.

The effect of rooibos tea (Aspalathus linearis) on liver antioxidant status and oxidative stress was investigated in rat model of carbon tetrachloride-induced liver damage. Synthetic antioxidant N-acetyl-L-cysteine (NAC) was used for comparison. Administration of carbon tetrachloride (CCl4) for 10 weeks decreased liver concentrations of reduced and oxidized forms of coenzyme Q9 (CoQ9H2 and CoQ9), reduced -tocopherol content and simultaneously increased the formation of malondialdehyde (MDA) as indicator of lipid peroxidation. Rooibos tea and NAC administered to CCl4-damaged rats restored liver concentrations of CoQ9H2 and alpha-tocopherol and inhibited the formation of MDA, all to the values comparable with healthy animals. Rooibos tea did not counteract the decrease in CoQ9, whereas NAC was able to do it. Improved regeneration of coenzyme Q9 redox state and inhibition of oxidative stress in CCl4-damaged livers may explain the beneficial effect of antioxidant therapy. Therefore, the consumption of rooibos tea as a rich source of natural antioxidants could be recommended as a market available, safe and effective hepatoprotector in patients with liver diseases.

Acetylcysteine↗
PubMed2003

Heterologous expression of the flavonoid 3',5'-hydroxylase gene of Vinca major alters flower color in transgenic Petunia hybrida.

Flavonoid 3',5'-hydroxylase (F3'5'H) is the key enzyme for the expression of blue or purple flower color. A full-length cDNA for the F3'5'H gene was cloned from petals of Vinca major, and its genomic clone, designated VmFH1 (accession number AB078781 in the GenBank/EMBL/DDBJ databases), was isolated from leaves by a PCR-based strategy. Nucleotide sequence analysis revealed that VmFH1 contains one intron and an open reading frame encoding a polypeptide of 506 amino acid residues. The deduced amino acid sequence shows between 51% and 83% identity with those of previously reported F3'5'H genes. Southern blot analysis showed that there are 3-4 copies of the F3'5'H gene in the genome of V. major. Transcripts of the F3'5'H gene were detected in young flower petals but not in leaves as revealed by RT-PCR analysis. When VmFH1 was expressed in transgenic Petunia hybrida under the control of the cauliflower mosaic virus 35S promoter, some transgenic plants showed drastic flower color alteration from red to deep red with deep purple sectors. These transgenic plants accumulated 3',5'-hydroxylated anthocyanins in their petals, which were never detected in non-transgenic plants by high-performance liquid chromatography analysis. These results indicate that VmFH1 isolated from V. major encodes F3'5'H and is active in a heterologous plant species.

Amino Acid Sequence↗
PubMed2003

Fgf-2 regulates enamel and dentine formation in mouse tooth germ.

We examined the effects of basic fibroblast growth factor (FGF-2) on cultured lower molar tooth germ at the differentiative (bell) stage. Although FGF-2 has been detected in odontogenesis, its roles in biological activities, such as cell proliferation, differentiation and extracellular matrix mineralization are unclear. We assayed mRNA levels of the differentiation markers, dentine sialophosphoprotein (DSPP), amelogenin and alkaline phosphatase (ALP) using reverse transcription-polymerase chain reaction (RT-PCR), and histological methods. Tooth germs dissected from 17-day-old embryonic mice were cultured for 4 days with either recombinant human FGF-2 or specific antisense phosphorothioate oligodeoxynucleotide (antisense ODN) for FGF-2. Exogenous FGF-2 decreased the gene expression of differentiation markers in molars at the bell stage. Abrogation of endogenous FGF-2 by antisense ODN increased the gene expression of differentiation markers, and also significantly enhanced enamel and dentine formation. This histological change was recovered by adding exogeneous FGF-2. These findings suggest that FGF-2 at the bell stage regulates cell differentiation and matrix secretion.

Alkaline Phosphatase↗
PubMed2003

Production of transgenic lily plants by Agrobacterium-mediated transformation.

A system for the production of transgenic plants was developed for the Oriental hybrid lily, Lilium cv. Acapulco, by Agrobacterium-mediated genetic transformation. Filament-derived calli were co-cultivated with A. tumefaciens strain EHA101/pIG121Hm, which harbored a binary vector carrying the neomycin phosphotransferase II, hygromycin phosphotransferase, and intron-containing beta-glucuronidase genes in the T-DNA region. Six hygromycin-resistant (Hyg(r)) culture lines were obtained from 200 calli by scratching them with sandpaper prior to inoculation and using NH(4)NO(3)-free medium for co-cultivation and a hygromycin-containing regeneration medium for selection. Hyg(r) culture lines regenerated shoots, which developed into plantlets following transfer to a plant growth regulator-free medium. All of these plantlets were verified to be transgenic by GUS histochemical assay and inverse PCR analysis.

Agrobacterium tumefaciens↗
PubMed2003

Equation-of-state measurements of polyimide at pressures up to 5.8 TPa using low-density foam with laser-driven shock waves.

The laser-driven equation-of-state (EOS) experiments for polyimide are presented. The experiments were performed with emission measurements from the rear sides of shocked targets at up to a laser intensity of 10(14) W/cm(2) or higher with 351 nm wavelength and 2.5 ns duration. Polyimide Hugoniot data were obtained up to 0.6 TPa with good accuracy. Applying low-density foam ablator to the EOS unknown material, we also obtained the data at a highest pressure of 5.8 TPa in the nonmetal materials. Those data were in agreement with the theoretical curves.

Journal Article↗
PubMed2003

Prevalence of Helicobacter pylori in NSAID users with gastric ulcer.

OBJECTIVE: Regarding the interaction of Helicobacter pylori and non-steroidal anti-inflammatory drugs (NSAIDs), we cannot accept unanimous conclusions in inducing gastric ulcer. We therefore evaluated the role of Helicobacter pylori and NSAIDs in inducing gastric ulcer. METHODS: Dyspeptic patients receiving NSAIDs underwent endoscopic examination. Gastric ulcer formation and H. pylori status were investigated. Biopsy specimens from the antrum and lower body of the stomach were prepared for the rapid urease test and pathological evaluation. Anti-H. pylori antibody was measured by enzyme-linked immunosorbent assay. RESULTS: Two hundred and twenty-six patients receiving NSAIDs (220 chronic and six on-demand users) underwent gastrofibrescopic examination. There were 110 patients with gastric ulcer and 111 non-ulcer patients with gastritis. The remaining five patients had neither. NSAID users with gastric ulcer showed a low prevalence of H. pylori compared with those without them [55/110 (50.0%) vs 79/111 (71.2%), P < 0.01]. The same tendency was seen when patients receiving low-dose aspirin and those with rheumatoid arthritis were analysed separately [13/29 (44.8%) vs 50/62 (80.6%), P < 0.01, and 11/33 (33.3%) vs 16/26 (61.5%), P < 0.06 with Yates' correction, respectively]. CONCLUSION: Helicobacter pylori infection appeared to be a risk factor for developing gastritis, but we found no evidence that it increases gastric ulcer formation in NSAID users with dyspepsia.

Aged↗
PubMed2003

Horticultural characterization of Angelonia salicariifolia plants transformed with wild-type strains of Agrobacterium rhizogenes.

Genetic transformation was carried out with wild-type strains of Agrobacterium rhizogenes for introducing a dwarf trait into the Scrophulariaceous ornamental plant, angelonia (Angelonia salicariifolia). Leaf segments of two angelonia genotypes (Ang.1 and Ang.2) were co-cultivated with mikimopine-type strains of A. rhizogenes. Adventitious roots that showed vigorous growth and increased lateral branching when cultured on half-strength Murashige and Skoog's (MS) basal salts medium lacking plant growth regulators (PGRs) after co-cultivation were selected as putatively transformed lines. All of these selected lines produced mikimopine. Adventitious shoots were efficiently induced from putatively transformed root segments on half-strength MS basal salts medium containing 1 mg l(-1) benzyladenine (BA) under continuous illumination (24-h photoperiod), and the shoots easily rooted following their transfer to half-strength MS basal salts medium lacking PGRs. The transgenic nature of regenerated plants was confirmed by Southern hybridization. Transformed plants frequently died during their acclimatization, and acclimatized plants of eight transformed lines grew very slowly for 1-5 months after transplantation to the greenhouse. Plants of two transformed lines of Ang.2 flowered 4-6 months after transplantation. These transformed plants exhibited phenotypic alterations such as dwarfness and smaller leaves. There were no apparent alterations observed in the number, shape, and size of the flowers. Pollen fertility of the transformed plants was 60-80% based on aceto-carmine staining. These results indicate the possibility of applying A. rhizogenes-mediated transformation for introducing a dwarf trait into angelonia.

Blotting, Southern↗
PubMed2003

Adaptation of Cucumber mosaic virus soybean strains (SSVs) to cultivated and wild soybeans.

Cucumber mosaic virus soybean strains formerly called soybean stunt virus (SSV) were inoculated onto 23 wild soybeans collected from four Asian countries to investigate their infectivity in order to improve understanding of the co-evolution of SSVs and soybean. SSV inoculation resulted in systemic infection in most of the wild soybeans used. However, an SSV strain (SSV-In), which was isolated in Indonesia, did not result in systemic infection of many of the wild soybeans distributed in southern Japan. This exceptional infectivity of SSV-In may be due to its specific adaptation to the local soybean population(s) of Indonesia, which has rarely been affected by gene flows from wild soybean. In the present study, the nucleotide sequences of the 3a and CP genes of SSV were determined, and the data were used to classify seven SSV isolates among known Cucumber mosaic virus (CMV) strains. The phylogenetic analysis showed that the seven SSVs formed a distinct cluster separated from the other CMV strains despite their different geographical origins; SSV-In was the most divergent of the seven isolates. Comparison of the rates of synonymous and nonsynonymous substitutions revealed that the SSV group had evolved faster than subgroup IA. The implications of the findings are discussed in relation to the so-called Red Queen hypothesis.

Adaptation, Physiological↗
PubMed2003

Regional N-acetyl-aspartate level and immunohistochemical damage in the hippocampus after transient forebrain ischemia in gerbils.

We investigated changes in regional N-acetyl-aspartate (NAA) levels in the vulnerable CA1 and resistant CA3 areas of the hippocampus after transient forebrain ischemia in gerbils. Under light ether anesthesia, bilateral common carotid arteries of adult male Mongolian gerbils (60-80 g) were occluded for 5 min and reperfused for 7 days. Brains from experimental and control gerbils (n = 4 each) were frozen in situ, and frozen sections (20 microm) were prepared using cryostat (-20 degrees C). After overnight lyophilization, the CA1 and CA3 areas were dissected out separately, weighed (50-200 microg), and the supernatant of the perchloric acid extract was used for assay of NAA using HPLC. Adjacent 10 microm-thick sections were used for immunohistochemical analysis using antiserum against microtubule-associated protein I and II. The preischemic NAA levels were not significantly different between CA1 and CA3 areas. After transient ischemia, a significant (P < 0.01) decrease in the NAA level was observed in the CAI area, but not in the CA3 area of the hippocampus. Immunohistochemical ischemic damage evolved only in the CA1 area. Thus, the decrease of the regional NAA level was associated with development of immunohistochemical neuronal damage.

Animals↗
PubMed2003

Inhibitory effect of titanium particles on osteoclast formation generated by treatment of mouse bone marrow cells with PGE2.

OBJECTIVE: The present study was designed to evaluate the effect of titanium (Ti) particles with no endotoxin on osteoclast differentiation and osteoclast activity in in vitro experiments. METHODS: Osteoclast formation as well as osteoclastic bone resorbing activity were examined using the mouse bone marrow culture system and purified rabbit osteoclasts treated with Ti particles (2.5-20 microgram cm-2). RESULTS: Ti particles, with no adherent endotoxin, inhibited osteoclastogenesis and receptor activator of NF-kappaB ligand (RANKL) expression in bone marrow cells treated with prostaglandin E2 (PGE2) (100 nM). The inhibitory effect of Ti particles was concentration-dependent (5-20 microgram cm-2), and was observed only on the generation of osteoclasts by PGE2, but not by 1,25-dihydroxyvitamin D3 or soluble RANKL. This suggests that Ti particles did not act uniformly on a common process in the generation of osteoclasts, but specifically on signal transduction for PGE2 in generating osteoclasts. In highly purified osteoclasts, Ti particles showed no effect on survival and bone resorbing activity. CONCLUSION: Ti particles inhibited osteoclast differentiation and RANKL expression in mouse bone marrow cells treated with PGE2, without affecting mature osteoclast survival or activity. Thus, Ti particles may alter the osteoclastogenetic action of PGE2, which is one of the regulatory factors of bone remodeling.

Animals↗
PubMed2003

Differential metabolism of midazolam in mouse liver and intestine microsomes: a comparison of cytochrome P450 activity and expression.

1. Although multiple cytochrome P450s (CYP) contribute to hepatic phase I metabolism, CYP3A is the principal subfamily present in human and mouse small intestine. 2. Differences in phase I metabolism were investigated using midazolam (MDZ) hydroxylation in mouse liver and intestinal microsomes. The net MDZ metabolite formation rate in intestinal microsomes was approximately 30% that of liver microsomes (at 250 micro M MDZ). 3. Quantitative Western blotting with anti-CYP3A1 antibody detected two bands of immunoreactive protein in both liver and intestinal samples, 2.24 +/- 0.27 (mean +/- SD, n = 3) and 0.64 +/- 0.08 pmol mg(-1) protein, respectively. Qualitative Western blotting with anti-CYP2C11 antibody detected a single band of immunoreactive protein in liver microsomes and no signal in intestinal samples (1 micro g sample). 4. Ketoconazole potently inhibited formation of both alpha- and 4-OH-MDZ metabolites in intestinal microsomes (IC(50)' of 0.126 +/- 0.010 and 0.0955 +/- 0.014 micro M, respectively) and of 4-OH-MDZ formation in mouse liver microsomes (IC(50) of 0.041 +/- 0.003 micro M). However, ketoconazole (5 micro M) did not produce 50% inhibition of alpha-OH-MDZ formation in mouse liver microsomes. Inhibition by ritonavir (5 micro M) produced similar results. 5. MDZ hydroxylation is predominately CYP3A dependent in mouse intestine (compared with mouse liver) since CYP2C is not expressed in the intestine. The importance of CYP3A in the mouse intestine appears to mirror that in humans.

Algorithms↗
PubMed2003

Hepatoprotective effect of rooibos tea (Aspalathus linearis) on CCl4-induced liver damage in rats.

Hepatoprotective properties of rooibos tea (Aspalathus linearis) were investigated in a rat model of liver injury induced by carbon tetrachloride (CCl(4)). Rooibos tea, like N-acetyl-L-cysteine which was used for the comparison, showed histological regression of steatosis and cirrhosis in the liver tissue with a significant inhibition of the increase of liver tissue concentrations of malondialdehyde, triacylglycerols and cholesterol. Simultaneously, rooibos tea significantly suppressed mainly the increase in plasma activities of aminotransferases (ALT, AST), alkaline phosphatase and billirubin concentrations, which are considered as markers of liver functional state. The antifibrotic effect in the experimental model of hepatic cirrhosis of rats suggests the use of rooibos tea as a plant hepatoprotector in the diet of patients with hepatopathies.

Acetylcysteine↗
PubMed2002

Comparison of gastroduodenal, renal and abdominal fat biopsies for diagnosing amyloidosis in rheumatoid arthritis.

The aim of the study was to determine the frequency of amyloidosis detected by gastroduodenal biopsy in rheumatoid arthritis (RA) patients, and to investigate correlations between the results of gastroduodenal biopsy and abdominal fat and renal biopsies. A total of consecutive 1006 RA patients underwent gastroduodenal biopsy. The 71 patients who tested positive for gastrointestinal (GI) amyloidosis were asked to undergo renal and abdominal fat biopsies, and 21 did so. Renal biopsies were also performed on 12 patients with no amyloidosis but indicators of drug-induced renal damage, and abdominal fat biopsies were performed on 50 RA patients with no indication of amyloidosis. The prevalence of GI amyloidosis was 7.1%. Urinary abnormalities and GI symptoms were common in GI amyloidisis, and inflammatory markers were elevated. Sixty-one (86%) had either depressed creatinine clearance or urinary symptoms. Nineteen of the 21 patients (91%) with GI amyloidosis who underwent renal biopsies also had renal amyloid deposits. Eleven of the 21 (52%) had amyloidosis on abdominal fat biopsy. None of the 12 patients without GI amyloidosis had renal amyloidosis on renal biopsy, and none of the 50 patients without GI amyloidosis had amyloidosis on abdominal fat biopsy. Gastroduodenal biopsy reveals a high prevalence of amyloidosis in RA patients. Amyloidosis is often associated with signs of renal impairment. Results of GI biopsy are highly correlated with those of renal biopsy, but the results of fat biopsy are not. We recommend GI biopsy for RA patients for the screening of systemic amyloidosis.

Abdominal Wall↗
PubMed2002

Interleukin-2 levels are elevated in the bone marrow serum of patients with mutilans-type rheumatoid arthritis.

In order to investigate the pathogenesis of mutilans-type rheumatoid arthritis (RA), we measured cytokine levels in the bone marrow serum of patients with RA. We studied 35 patients with non-mutilans RA, 19 with mutilans RA, and 20 patients with osteoarthritis (OA) undergoing joint surgery. At the time of surgery, iliac bone marrow and peripheral blood were sampled from all 74 patients and cytokine levels measured. The serum levels of five cytokines (IL-1beta, IL-2, IL-3, IL-6 and GM-CSF) were measured by ELISA. Haematologic and inflammatory factors were also measured. Levels of IL-2, IL-6 and GM-CSF in bone marrow serum were significantly higher in all RA patients than in those with OA. Mean (+/-SD) IL-2 levels were significantly higher in patients with mutilans-type RA (309.8+/-686.3 pg/ml) than in patients with other types of RA (66.5+/-173.1 pg/ml; P<0.01). IL-2 was detected significantly more often in patients with mutilans-type RA than in patients with other types of RA (P < 0.01). Inflammatory factors were higher in all RA groups than in OA patients. However, the haematologic and immunologic variables were no different between mutilans RA and other types of RA. No correlations were observed between IL-1beta, IL-2, IL-3, IL-6 and GM-CSF levels and these laboratory variables. In patients with mutilans-type RA, IL-2 levels in the bone marrow serum were significantly higher than in patients with other types of RA or with OA. This elevation does not appear to be related to systemic inflammation, as there was no correlation with other inflammatory factors.

Aged↗
PubMed2002

Emergence of a functional coupling between inositol-1,4,5-trisphosphate receptors and calcium channels in developing neocortical neurons.

Cortical pyramidal neurons are considered to be less excitable in the immature cortex than in adults. Our previous report revealed that a negative feedback regulation of membrane excitability is highly correlated with a novel form of calcium release from inositol-1,4,5-trisphosphate (IP(3))-sensitive calcium stores (IP(3)-assisted calcium-induced calcium release) in neocortical pyramidal neurons under muscarinic cholinergic activation. As a step to understand the ground for the low membrane excitability in immature tissue, we examined development of IP(3)-assisted calcium-induced calcium release. In visual cortex neurons from 'juvenile' rats (2-3 weeks of age), an enhancement of spike-frequency adaptation occurred at high spike-frequencies (16-22 Hz), whereas the reduction was observed at low frequencies (6-10 Hz). IP(3)-assisted calcium-induced calcium release occurred at the higher frequencies only. In 'early' postnatal tissue (1 week of age), by contrast, at neither high nor low frequencies did this form of calcium release occur, and muscarinic cholinergic activation always induced a reduction of spike-frequency adaptation at any spike-frequencies. The mechanism for the failure of induction of IP(3)-assisted calcium-induced calcium release in 'early' postnatal tissue was investigated. Both an ample supply of calcium influx, elicited by higher frequency spike trains, and a supplementary injection of IP(3) through whole-cell pipets, combined together or applied alone, failed to enable IP(3)-assisted calcium-induced calcium release in 'early' postnatal tissue. Muscarinic cholinergic activation alone induced a conventional IP(3)-induced calcium release similar to that observed in neurons from 'juvenile' tissue. Together, it is most likely that functional IP(3)Rs and calcium channels are already present and functional, but are not yet adequately assembled to allow IP(3)-assisted calcium-induced calcium release in cortical pyramidal neurons from rats of 1 week old.

Action Potentials↗
PubMed2002

A distinct form of calcium release down-regulates membrane excitability in neocortical pyramidal cells.

We reported a novel type of calcium release from inositol-1,4,5-trisphosphate (IP(3))-sensitive calcium stores synergistically induced by muscarinic acetylcholine receptor (mAchR)-mediated increase in IP(3) and action potential-induced calcium influx (IP(3)-assisted calcium-induced calcium release, IP(3)-assisted CICR). To clarify its functional significance, the effects of IP(3)-assisted CICR on spike-frequency adaptation were examined in layer II/III neurons from rat visual cortex slices. IP(3)-assisted CICR was enabled with a high concentration of the mAchR agonist carbachol (10 microM). The magnitude of this CICR was the more augmented at higher firing frequencies. With 10 microM carbachol, spike-frequency adaptation was reduced for spike trains at 'low' firing frequencies (6-10 Hz), but was rather enhanced at 'high' firing rates (16-22 Hz): excitability was down-regulated at 'high' frequencies. With 1 microM carbachol, by contrast, IP(3)-assisted CICR failed to occur, and spike-frequency adaptation was always reduced at any spike frequencies. Intracellular injection of the IP(3) receptor blocker heparin prevented both the mAchR-mediated occurrence of IP(3)-assisted CICR and enhancement of spike-frequency adaptation with 10 microM carbachol. Both of these mAchR-mediated effects were reproduced by intracellular IP(3) injection, and were shown to be associated with each other by simultaneous recordings of membrane potential and intracellular calcium increase. We propose that IP(3)-assisted CICR offers a novel way to protect these cortical neurons from hyperexcitability and presumably from excitotoxic cell death.

Action Potentials↗