Biomedical subjects

H Tanaka

Publications and source records attributed to H Tanaka.

At least 127 records · Page 7Linked to original sources

PubMed2004

Profiling analysis of differential gene expression between hematogenous and peritoneal metastatic sublines of human pancreatic cancer using a DNA chip.

We established the novel sublines HPC-1H5, HPC-3H4, HPC-4H4, and Panc-1H5, which have a high potential of liver metastasis, and HPC-1P5a, HPC-3P4a, HPC-4P4a, and Panc-1P5a, which have a high potential of peritoneal dissemination, derived from low metastatic HPC-1, HPC-3, HPC-4, and Panc-1cell lines, respectively. To clarify the molecular mechanisms of cancer metastasis and of the different levels of gene expression in a variety of metastatic potentials in pancreatic cancer, we performed a broad analysis of differential gene expression analysis between parental cell lines and metastatic sublines. In comparison with the parental cell lines, 65 and 36 genes were overexpressed and underexpressed in highly liver-metastatic sublines. On the other hand, 43 and 45 genes were overexpressed and underexpressed in highly peritoneal-metastatic sublines. uPAR and Serin protease were overexpressed, and E2A and IGF1R were underexpressed in both metastatic sublines. Hierarchical clustering analysis revealed 22 genes classifying liver, peritoneal metastatic sublines and low-metastatic parental cell lines. These genes might be targeted genes separating those two major metastatic forms after surgery. A greater number of cell line samples and more genes will have to be utilized in future studies in order to understand the involvement of genes in cancer metastasis more thoroughly. However, these results will help to clarify the molecular mechanisms of pancreatic cancer metastasis.

Cell Line, Tumor↗

PubMed2003

Musculoskeletal disorders among hospital nurses in rural Japan.

INTRODUCTION: Although musculoskeletal disorders (MSD) represent a significant occupational problem for hospital nurses, few investigations target nurses in rural facilities. This study investigated the prevalence and correlates of MSD among nurses within an affiliated hospital conglomerate of rural Japan. METHODS: A self-reporting survey was used as diagnostic tool; the reliability, validity and cost-effectiveness of this method has been established. RESULTS: An initial group of 329 nurses was recruited from three affiliated, rural locations in Yamanashi prefecture, central Japan; 247 usable replies were obtained (final response rate: 75.1%). The 12-month period-prevalence of self-reported MSD at any body site was 91.9% (95% CI 87.8-94.7). Low back pain (LBP) was the most commonly reported MSD with a prevalence of 82.6% (95% CI 77.4-86.8). Next most reported were shoulder (61.1%, 95% CI 54.9-67.0), neck (36.8%, 95% CI 31.1-43.0), upper back (29.1%, 95% CI 23.8-35.1), knee (23.5%, 95% CI 18.6-29.1) and upper leg MSD (19.4%, 95% CI 15.0-24.8). MSD of the wrist (14.2%, 95% CI 10.4-19.1), upper arm (13.0%, 95% CI 9.3 -17.7) and lower arm (11.7% 95% CI 8.3-16.4) were less common. Logistic regression indicated that nurses who were regularly involved in the manual handling of patients had an increased LBP risk of 16.7 (OR 16.7, 95% CI 1.3-412.7, p = 0.0340) when compared with nurses who were not involved in manual handling of patients. CONCLUSION: Overall, our study indicated that MSD is common among rural Japanese nurses and its prevalence is consistent between related facilities. The excessive amount of LBP, however, suggests that Japanese nurses are at higher risk of this condition compared with their foreign counterparts.

Journal Article↗

PubMed2003

Comparison of conventional and diffusion-weighted MRI and proton MR spectroscopy in patients with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like events.

The mechanism of neurological disturbances in patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is controversial. We studied 12 patients with MELAS using conventional and diffusion weighted MRI (DWI) and MR spectroscopy (MRS), to look at the physiopathology of the stroke-like events. Although conventional MRI showed lesions in all patients, DWI was more sensitive. One patient did not show high signal on DWI 48 h after a from stroke-like episode, but MRS demonstrated a lactate peak in left occipital lobe; 2 weeks after the attack, high signal was demonstrated on the right frontal lobe where MRS had shown a lactate peak. Our findings suggest a possible predictive ability of (1)H-MRS, in showing early MELAS lesions and supports the hypothesis that mitochondrial metabolic dysfunction may precedes abnormalities on DWI.

Adolescent↗

PubMed2003

Doppler effect in resonant photoemission from SF6: correlation between Doppler profile and Auger emission anisotropy.

Fragmentation of the SF6 molecule upon F 1s excitation has been studied by resonant photoemission. The F atomiclike Auger line exhibits the characteristic Doppler profile that depends on the direction of the photoelectron momentum relative to the polarization vector of the radiation as well as on the photon energy. The measured Doppler profiles are analyzed by the model simulation that takes account of the anisotropy of the Auger emission in the molecular frame. The Auger anisotropy extracted from the data decreases with an increase in the F-SF5 internuclear distance.

Journal Article↗

PubMed2003

Choledocholithiasis caused by migration of a surgical clip into the biliary tract following laparoscopic cholecystectomy.

As experience with laparoscopic cholecystectomy (LC) has increased, so have the number and variety of complications. We report a case of choledocholithiasis caused by migration of a surgical clip applied during LC. A 57-year-old Japanese man who had undergone LC 6 years previously was referred to our hospital with pruritus and jaundice. Magnetic resonance cholangiopancreatography and ultrasonography revealed a solid mass in the common hepatic duct and dilatation of the intrahepatic bile ducts. Abdominal arteriography demonstrated interruption of the right hepatic artery by surgical clips. Five days after a biopsy of the mass was performed through a percutaneous transhepatic biliary drainage tube, the mass moved to the terminus of the common bile duct along with one of the surgical clips. A basket catheter was used to remove the mass via endoscopy. Despite the fact that other clips in the common hepatic duct were partially exposed, the patient has been well for 2 years with no additional interventions.

Bile Ducts, Intrahepatic↗

PubMed2003

Anti-solasodine glycoside single-chain Fv antibody stimulates biosynthesis of solasodine glycoside in plants.

We constructed a recombinant antibody fragment--single chain fragment-variable (scFv) antibody--derived from hybridoma cell lines to control the concentration of solasodine glycosides in hairy root cultures of Solanum khasianum transformed by the anti-solamargine (As)-scFv gene. The properties of the As-scFv protein expressed in Escherichia coli were almost identical to those of the parent monoclonal antibody (MAb). Up to 220 ng recombinant As-scFv was expressed per milligram of soluble protein in transgenic hairy root cultures of S. khasianum. The concentration of solasodine glycosides was 2.3-fold higher in the transgenic than in the wild-type hairy root, as reflected by the soluble As-scFv level and antigen binding activities. These results suggested that the scFv antibody expressed in transgenic hairy roots controlled the antigen level, thus representing a novel plant breeding methodology that can produce secondary metabolites.

Amino Acid Sequence↗

PubMed2003

Sound attenuation study on the bose-Einstein condensation of magnons in TlCuCl3.

We investigate experimentally and theoretically sound attenuation in the quantum spin system TlCuCl3 in magnetic fields at low temperatures. Near the point of Bose-Einstein condensation of magnons a sharp peak in the sound attenuation is observed. The peak demonstrates a hysteresis as a function of the magnetic field pointing to a first-order contribution to the transition. The sound damping has a Drude-like form arising as a result of hard-core magnon-magnon collisions. The strength of the coupling between lattice and magnons is estimated from the experimental data. The puzzling relationship between the transition temperature and the concentration of magnons is explained by their "relativistic" dispersion.

Journal Article↗

PubMed2003

Cytokeratin-19 fragments in serum (CYFRA 21-1) as a marker in primary liver cancer.

Using an electrochemiluminescence immunoassay, CYFRA 21-1 concentrations were measured in sera from 187 patients with primary liver cancer (164 with hepatocellular carcinoma (HCC) and 23 with intrahepatic cholangiocarcinoma (ICC)) and 87 patients with benign liver diseases. Concentrations of CYFRA 21-1 were significantly higher in patients with ICC (5.0; interquartile range 3.1-10.7 ng ml(-1)) than in those with benign liver disease (1.4; 1.0-1.9; Mann-Whitney U-test, P<0.0001) or HCC (1.7; 1.1-2.7; Mann-Whitney U-test, P<0.0001). Using cutoff values selected for 95% specificity in the benign group (3.0 ng ml(-1)), CYFRA 21-1 showed higher sensitivity for ICC (87.0%) than three commonly used markers including alpha-fetoprotein (17.4%), carcinoembryonic antigen (34.8%), and carbohydrate antigen 19-9 (60.9%). Serum CYFRA 21-1 increased in ICC from stages I/II to IV (Kruskal-Wallis test, P=0.0102). CYFRA 21-1 concentration increased with extent of local invasion, but not nodal status. Serum CYFRA 21-1 represents a useful diagnostic test for ICC that offers high sensitivity. CYFRA 21-1 reflected differences in tumour burden, suggesting applicability to staging and follow-up.

Adult↗

PubMed2003

Anisotropic ultrafast dissociation probed by the Doppler effect in resonant photoemission from CF4.

The resonant Auger spectrum from the decay of F 1s-excited CF4 is measured. Several lines exhibit a nondispersive kinetic energy as the exciting photon energy is tuned through the resonance region. The F 1s(-1) atomiclike Auger line is split into two components due to the emission of Auger electrons by a fragment in motion, when electron emission is observed along the polarization vector of the light. This Doppler splitting is direct evidence that the core excitation leads to T(d)-->C(3v) symmetry lowering, by elongation of a specific C-F bond preferentially aligned along the polarization vector of the incident photon.

Journal Article↗

PubMed2003

Doppler-free resonant Raman auger spectroscopy of Ne+ 2s2p(5)3p excited states.

Using very high resolution achieved by the Doppler-free resonant Raman Auger technique, we have resolved the lowest terms of the series of inner-valence excitations 2s2p(5)((1,3)P)np 2S, 2P, and 2D in Ne+. The measured Auger anisotropic parameters and branching ratios help to establish the assignments of these levels. The measured lifetime widths are in reasonable agreements with ab initio calculations available in the literature.

Journal Article↗

PubMed2003

Improvement of rice (Oryza sativa L.) seed oil quality through introduction of a soybean microsomal omega-3 fatty acid desaturase gene.

Microsomal omega-3 fatty acid desaturase is an essential enzyme in the production of the n-3 polyunsaturated fatty acid alpha-linolenic acid during the seed developing stage. We have constructed a chimeric gene consisting of a maize Ubi1-P-int and a soybean GmFAD3 cDNA, which was introduced into rice plants by Agrobacterium-mediated transformation. Ten transformants containing the chimeric gene were established and expression subsequently confirmed by Northern blotting. Furthermore, alpha-linolenic acid content of the T(1) seeds increased dramatically up to tenfold that of the control, and this phenotype was also stably inherited in the T(2) and T(3) progenies. These results demonstrate that the alpha-linolenic acid content of rice seed oil can easily be altered using the combination of a high-activity promoter and a GmFAD3 gene.

Blotting, Northern↗

PubMed2003

Specific T-cell immunity against Ki-ras peptides in patients with pancreatic and colorectal cancers.

Mutations of codon 12 in the Ki-ras gene are frequently found in pancreatic and colorectal cancers. It has been demonstrated that human T-cells have the potential to recognise tumours expressing mutated ras-derived peptides. However, it remains unclear whether T-cells from a given individual can recognise the mutant peptides, which are expressed in that individual's tumour tissues. Mutations of the Ki-ras oncogene were analysed by the mutant-allele-specific amplification (MASA) method in pancreatic and colorectal tumour tissues, and T-cell responses against mutated Ki-ras-derived peptides were measured by [(3)H]thymidine incorporation and IFN-gamma production assays. Specific T-cell responses against Ki-ras-products were found in cancer patients, whereas no immune response was observed in normal individuals (P<0.01). Six of the eight pancreatic cancer patients (75%) and nine of 26 colorectal cancer patients (35%) had T-cell responses to mutated Ki-ras-derived-peptides. T-cell response in a given individual cannot recognise the same mutated ras peptide, which is expressed in that individual's tumour tissues. However, pancreatic and colorectal cancer patients have T-cell immunity against Ki-ras-peptides, and this provides potential target for cancer immunotherapy.

Cell Division↗

PubMed2003

A functional MRI study of somatotopic representation of somatosensory stimulation in the cerebellum.

Somatotopic representation in the cerebral cortex of somatosensory stimulation has been widely reported, but that in the cerebellum has not. We investigated the latter in the human cerebellum by functional MRI (fMRI). Using a 1.5 tesla imager, we obtained multislice blood oxygen level-dependent fMRI with single-shot gradient-echo echoplanar imaging in seven right-handed volunteers during electrical stimulation of the left index finger and big toe. In the anterior and posterior cerebellum, activated pixels for the index finger were separate from those for the toe. This suggests that somatosensory stimulation of different parts of the body may involve distinct areas of in the cerebellum as well as the cerebral cortex.

Adult↗

PubMed2003

Element- and size-dependent electron delocalization in AuNX+ clusters (X = Sc, Ti, V, Cr, Mn, Fe, Co, Ni).

We investigated the stability of gold clusters doped with open 3d-shell atoms (Sc, Ti, V, Cr, Mn, Fe, Co, Ni). Steps, peaks, and odd-even staggering in mass abundance spectra upon photofragmentation provide evidence for enhanced stability for specific cluster sizes. The observed magic numbers are explained in terms of size- and dopant-dependent modifications of the effective mean-field potential within a phenomenological shell-model approach. Element-dependent 3d electron delocalization and odd-even staggering amplitudes are related to the dopant-atom structure.

Journal Article↗

PubMed2003

Effects of the changes in enzyme activities on metabolic flux redistribution around the 2-oxoglutarate branch in glutamate production by Corynebacterium glutamicum.

An experimental method for metabolic control analysis (MCA) was applied to the investigation of a metabolic network of glutamate production by Corynebacterium glutamicum. A metabolic reaction (MR) model was constructed and used for flux distribution analysis (MFA). The flux distribution at a key branch point, 2-oxoglutarate, was investigated in detail. Activities of isocitrate dehydrogenase (ICDH), glutamate dehydrogenase (GDH), and 2-oxoglutarate dehydrogenase complex (ODHC) around this the branch point were changed, using two genetically engineered strains (one with enhanced ICDH activity and the other with enhanced GDH activity) and by controlling environmental conditions (i.e. biotin-deficient conditions). The mole flux distribution was determined by an MR model, and the effects of the changes in the enzyme activities on the mole flux distribution were compared. Even though both GDH and ICDH activities were enhanced, the mole flux distribution was not significantly changed. When the ODHC activity was attenuated, the flux through ODHC decreased, and glutamate production was markedly increased. The flux control coefficients of the above three enzymes for glutamate production were determined based on changes in enzyme activities and the mole flux distributions. It was found that the factor with greatest impact on glutamate production in the metabolic network was obtained by attenuation of ODHC activity.

Journal Article↗

PubMed2003

Global pollution monitoring of PCBs and organochlorine pesticides using skipjack tuna as a bioindicator.

Concentrations of organochlorines (OCs) representing persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs), dichlorodiphenyl trichloroethane and its metabolites (DDTs), chlordane compounds (CHLs), hexachlorocyclohexane isomers (HCHs), and hexachlorobenzene (HCB), were determined in the liver of skipjack tuna (Katsuwonus pelamis) collected from the offshore waters of various regions in the world (offshore waters around Japan, Taiwan, Philippines, Indonesia, Seychelles, and Brazil, and the Japan Sea, the East China Sea, the South China Sea, the Bay of Bengal, and the North Pacific Ocean). OCs were detected in livers of all of the skipjack tuna collected from the locations surveyed, supporting the thesis that there is widespread contamination of persistent OCs in the marine environment. Within a location, no significant relationship between growth-stage (body length and weight) and OC concentrations (lipid weight basis) was observed, and the OC residue levels were rather uniform among the individuals. Interestingly, the distribution of OC concentrations in skipjack tuna was similar to those in surface seawaters from which they were taken. These results suggest that OC concentrations in skipjack tuna could reflect the pollution levels in seawater from which they are collected and that this species is a suitable bioindicator for monitoring the global distribution of OCs in offshore waters and the open ocean. Concentrations of PCBs and CHLs in skipjack tuna were higher in offshore waters around Japan (up to 1100 and 250 ng/g lipid wt, respectively), suggesting the presence of sources of PCBs and CHLs in Japan. High concentrations of DDTs and HCHs were observed in samples from the Japan Sea, the East China Sea, the South China Sea, and the Bay of Bengal (up to 1300 and 22 ng/g lipid wt, respectively). This result suggests recent use of technical DDT and HCH for agricultural and/or public health purposes in Russia, China, India, and some other developing Asian countries. Relatively high concentrations of PCBs, CHLs, HCHs, and HCB were also observed in samples collected from some locations in the middle of the Pacific Ocean, indicating the expansion of OC contamination on a global scale. Considering these facts, continuous studies monitoring these compounds in offshore waters and the open seas, using skipjack tuna as a bioindicator, are needed to further understand the future trend of contamination.

Animals↗

PubMed2003

Tissue distribution of a new photosensitizer ATX-S10Na(II) and effect of a diode laser (670 nm) in photodynamic therapy.

The aims of the present study were to analyse the quantitative tissue distribution of ATX-S10Na(II) and to investigate the maximal effect of a diode laser and the irradiation conditions required to obtain this effect in photodynamic therapy (PDT) with ATX-S10Na(II). Spectrofluorometry was used to obtain quantitative tissue distribution of ATX-S10Na(II) in Colon 26 carcinoma-bearing mice as a function of time following administration. Next, transplanted tumours of mice with or without ATX-S10Na(II) were treated with the diode laser under conditions in which power density and irradiation time were varied. Tumour tissue concentrations of ATX-S10Na(II) were higher than in all tissues at all intervals following administration. The uptake of ATX-S10Na(II) by most tissues was rapid, with maximal concentrations occurring 1 h after i.v. injection, and ATX-S10Na(II) was almost excreted within 24 h after administration. The maximal depth of necrosis induced by PDT in the treated tumour was 7.9 mm under conditions in which power density was 160 mW/cm2 and total dose was above 100 J/cm2. PDT with ATX-S10Na(II) and the diode laser is useful for the treatment of superficial cancers.

Animals↗

PubMed2003

Removal of indoor pollutants under UV irradiation by a composite TiO2-zeolite sheet prepared using a papermaking technique.

Toluene and formaldehyde are malodorous and cause indoor pollution. These materials have received much attention as hazardous and malodorous substances. It is well known that long-term exposure to even fairly low levels of toluene and formaldehyde brings about the risk of asthma and eczema. In this study, a composite TiO2-zeolite (ZE) sheet prepared using a papermaking technique was applied to remove toluene and formaldehyde under UV irradiation. The optimum composition of the TiO2 (Ti)-ZE sheet was studied in detail with regard to the effective removal of various indoor pollutants. Gaseous toluene and formaldehyde were removed by a composite TiO2-ZE sheet with different efficiencies depending upon the ratio of Ti/ZE in the composite sheet. The composite sheets could decompose formaldehyde and toluene repeatedly after being recharged. It was shown that the sheets are potentially applicable as highly functional materials to be placed on walls and ceilings of houses for the removal of various indoor pollutants.

Air Pollutants↗