Biomedical subjects

Hitoshi Tanaka

Publications and source records attributed to Hitoshi Tanaka.

At least 19 recordsLinked to original sources

PubMed2006

Stable top-up operation at SPring-8.

Top-up operation allows SPring-8 to provide highly stable X-ray beams with arbitrary filling patterns. The implementation of top-up operation is described, with a focus on the simultaneous achievement of stability of stored current, beam orbit, purity of an isolated single bunch, and beam injection efficiency. Stored-current fluctuations have been routinely reduced to a level of 10(-3). Stored-beam oscillation on frequent beam injection, which was originally regarded as the most serious problem, has been successfully suppressed to a sufficiently low level that it never perturbs imaging experiments. Current impurities in nominally empty buckets have been reduced to a level of 10(-9) over more than one week of operation, making possible the measurement of time-resolved spectra using high-current bunches. Finally, excellent injection efficiency, higher than 80%, is routinely obtained, even for small undulator gaps, which is critical for preventing radiation damage to insertion-device magnets and to reduce leakage radiation. The process of achieving highly stabilized top-up operation at SPring-8 and its utility for user experiments are described.

Electrons↗

PubMed2006

[Two cases of advanced pancreas cancer treated with GTX: combined use of gemcitabine, docetaxel and capecitabine].

Two cases of advanced pancreas cancer were treated with GTX. One cycle was 3 weeks, capecitabine (1,000 mg/m(2)/day) was administered from day 1 to 14, and GEM 750 mg/m(2) and DOC 30 mg/m(2) were drip-infused on day 4 and 11. A 62-year-old man with pancreas head cancer and 2 liver metastases was treated with GEM 1,000 mg/m(2)/week at weeks 1, 2, and 3, and drug-free week 4 for 3 cycles, but was PD. After 3 cycles of GTX, the liver metastases decreased in size, and thereafter tumor markers became lowest after 7 cycles. The patient was shifted to another regimen after 14 cycles for 9 months of GTX. A 75-year-old man with pancreas head cancer and vascular invasion has been treated with GTX. As leukopenia was seen after the first cycle, the administration doses were reduced and GTX has been continued for a total 13 cycles. The tumor reduced in size and tumor markers decreased. GTX is suitable for outpatient chemotherapy with mild adverse effects.

Adenocarcinoma↗

PubMed2004

Perturbative formulation for nonlinear chromaticity of circular accelerators.

The nonlinear chromaticity plays an important part in the dynamics of a particle at far off-momentum in a strong focusing circular accelerator. We derived the exact perturbative formula of the nonlinear dispersion function of a ring accelerator and gave explicit expressions of higher-order terms. Using the perturbative formula for the dispersion function, we derived the higher-order expressions for the nonlinear chromaticity up to the third order. We numerically estimated the nonlinear chromaticity of the SPring-8 storage ring, and it showed fairly good agreement with the measurement.

Journal Article↗

PubMed2004

Six new constituents from the roots of Erythrina variegata.

Three new isoflavonoids, eryvarins M-O (1-3), two new 2-arylbenzofurans, eryvarins P and Q (4 and 5), and a new 3-aryl-2,3-dihydrobenzofuran, eryvarin R (6), together with three known compounds, were isolated from the roots of Erythrina variegata. The structures of these compounds were established by spectroscopic analysis. Eryvarin R (6) is an unusual 3-aryl-2,3-dihydrobenzofuran derivative with a formyl (CHO) group. Eryvarin Q (5) showed potent antibacterial activity against methicillin-resistant Staphylococcus aureus.

Erythrina↗

PubMed2004

A case of mediastinal goiter.

A case of mediastinal goiter in a 51-year-old female is reported. She demonstrated an abnormal shadow on chest X-ray but there were no clinical symptoms. Tumors were recognized in the isthmus of the thyroid and mediastinum on CT scan and MRI. These two tumors were resected via standard neck skin incision and sternotomy. At surgery, we found no communication between the two tumors. Following Rives' classification, the mediastinal tumor in this case was diagnosed as aberrant mediastinal goiter. Pathological diagnoses of both tumors were adenomatous goiter.

Adenoma↗

PubMed2004

Warthin's tumor of the nasopharynx: a case report.

Warthin's tumor in the nasopharynx is extremely rare. A 76-year-old man was referred to our hospital for treatment of a nasopharyngeal tumor. Fiberscopic examination, CT and MRI findings showed an oval mass in the right side of the posterior nasopharynx. The tumor was resected surgically using the transpalatal approach. Pathological examination indicated Warthin's tumor. There have not been any signs of recurrence postoperatively.

Adenolymphoma↗

PubMed2004

Synergistic effects of mupirocin and an isoflavanone isolated from Erythrina variegata on growth and recovery of methicillin-resistant Staphylococcus aureus.

The phytochemical 2',4'-dihydroxy-8-gamma,gamma-dimethylallyl-2",2"-dimethylpyrano[5",6":6,7]isoflavanone (bidwillon B) was isolated from Erythrina variegata and its antibacterial properties against methicillin-resistant Staphylococcus aureus (MRSA) were investigated. Bidwillon B inhibited the growth of 12 MRSA strains at minimum inhibitory concentrations (MICs) of 3.13-6.25mg/l, while MICs of mupirocin were 0.20-3.13 mg/l. The minimum bactericidal concentration (MBC) for bidwillon B and mupirocin against MRSA were 6.25-25mg/l (MBC(90): 12.5mg/l) and 3.13-25mg/l (MBC(90): 25mg/l), respectively. When bidwillon B and mupirocin were combined, synergistic effects were observed for 11 strains of MRSA (fractional inhibitory concentration indices, 0.5-0.75). The MBCs of mupirocin in the presence of bidwillon B (3.13 mg/l) were reduced to 0.05-1.56 mg/l. Bidwillon B at MIC values strongly inhibited incorporation of radio-labelled thymidine, uridine, glucose and isoleucine into MRSA cells. Mupirocin showed lower inhibitory effects than bidwillon B on thymidine, uridine and glucose incorporation, but incorporation of isoleucine was completely blocked with this antibiotic. These results indicate that bidwillon B possesses sufficient anti-MRSA activity for inhibiting growth and recovery, and that the compound acts synergistically with mupirocin. The results also suggest that both compounds act on MRSA via different mechanisms. Bidwillon B may prove to be a potent phytotherapeutic and/or combination agent with mupirocin in the elimination of nasal and skin carriage of MRSA.

Anti-Bacterial Agents↗

PubMed2004

Anti-oxidative compounds in barley tea.

Five phenolic compounds, p-hydroxyacetophenone, 5,7-dihydroxychromone, naringenin, quercetin, and iso-americanol A, were found first time in the barley tea, together with the known compounds, p-hydroxybenzaldehyde, 3,4-dihydroxybenzaldehyde, p-hydroxybenzoic acid, vanillic acid, and p-coumaric acid. The anti-oxidative properties were evaluated by measuring their peroxynitrite-scavenging activities. Among these compounds, 3,4-dihydroxybenzaldehyde, p-coumaric acid, quercetin, and isoamericanol A showed stronger activities than that of BHT (butylated hydroxytoluene) at 400 microM.

Antioxidants↗

PubMed2003

Synchronous bilateral noninvasive ductal carcinoma of the male breast: a case report.

A 45-year-old man developed a bloody discharge from his right nipple. Physical examination revealed bloody discharge from his left nipple also but no swelling, breast mass, or axillary lymph nodes. He then underwent bilateral total glandectomy without axillary dissection. Histological examination revealed low-grade ductal carcinoma in situ (DCIS) with a low-papillary and cribriform pattern measuring about 4 mm in diameter in the breast bilaterally. To our knowledge, this is the first report of synchronous bilateral DCIS in a male. Since this patient's hormonal profile showed a relatively high blood level of prolactin, the causative relationship between hyperprolactinemia and male breast cancer is discussed. Including our case, 5 of 6 cases reported thus far have been bilateral, and 4 of the 6 cases have been synchronous. We emphasize that the contralateral breast should also be tested or followed in male breast cancer patients with hyperprolactinemia.

Breast Neoplasms, Male↗

PubMed2003

Expression of ATP-binding cassette transporter in human salivary ducts.

P-glycoprotein expression has been observed in normal tissues as well as malignant tumours and thus does not appear to be induced by anticancer drugs. Knowledge of the distribution of ATP-binding cassette (ABC) transporters other than P-glycoprotein in normal salivary tissue is essential for understanding the physiological secretion or excretion of potentially toxic substances. Here the expression of ABC transporters was studied immunohistochemically in normal salivary gland tissue from nine patients. In striated duct cells, staining was strong for P-glycoprotein, multidrug resistance-associated protein (MRP) 1, MRP 2/canalicular multispecific organic anion transporter (cMOAT), and lung resistance-related protein (LRP). The staining intensity of acinar and intercalated duct cells for MRP 1 expression was distinct from that for MRP2/cMOAT, but was similar to that for P-glycoprotein. LRP was observed as particles between the nuclear and luminal membranes in the cytoplasm of intercalated duct cells. The expression of ABC transporters suggests that numerous transporters other than those studied might be isolated from normal salivary tissues. These observations indicate that these ABC transporters may not arise from any previous contact with anticancer drugs but are expressed physiologically. The achieved drug resistance as well as the physiological secretory function of ABC transporters could contribute to the responsiveness to chemotherapy of malignant salivary tumours.

ATP-Binding Cassette Transporters↗

PubMed2003

Eryvarins F and G, two 3-phenoxychromones from the roots of Erythrina variegata.

Two 3-phenoxychromones, eryvarins F and G, were isolated from the roots of Erythrina variegata. Their structures were established to be 3-(2,4-dihydroxyphenoxy)-7-hydroxy-6,8-di(3,3-dimethylallyl)chromen-4-one and 3-(2,4-dihydroxyphenoxy)-8-(3,3-dimethylallyl)-2,2-dimethylpyrano[5,6:6,7]chromen-4-one on the basis of spectroscopic and chemical evidence. Eryvarins F and G are unusual 3-phenoxychromone derivatives with two isoprenoid groups.

Chromatography, Gel↗

PubMed2003

An arylbenzofuran and four isoflavonoids from the roots of Erythrina poeppigiana.

An arylbenzofuran, erypoegin F and four isoflavonoids, erypoegins G-J, together with six known compounds were isolated from the roots of Erythrina poeppigiana, and their structures were elucidated on the basis of spectroscopic evidence. Erypoegin F is a rare 2-arylbenzofuran possessing a formyl group from a natural source, and erypoegin I is the first naturally occurring isoflavonoid with a 2-oxo-3-methylbutyl group.

Benzofurans↗

PubMed2003

Isoflavonoids from roots of Erythrina zeyheri.

Five isoflavonoids, (+/-)-7,2',4'-trihydroxy-8,3'-di(gamma,gamma-dimethylallyl)isoflavanone, (3R)-7,4'-dihydroxy-2'-methoxy-6,8-di(gamma,gamma-dimethylallyl)isoflavanone, (3R)-7,2',4'-trihydroxy-6,8-di(gamma,gamma-dimethylallyl)isoflavan, 2',4'-dihydroxy-8-gamma,gamma-dimethylallyl-2",2"-dimethylpyrano-[5,6:6,7]isoflavan and (6aS, 11aS)-3,6a-dihydroxy-9-methoxy-4,10-di(gamma,gamma-dimethylallyl)pterocarpan, along with five known compounds, were isolated from the roots of Erythrina zeyheri. Their structures were established on the basis of spectroscopic evidence, and their antibacterial activities against methicillin-resistant Staphylococcus aureus (MRSA) were estimated by determining minimum inhibitory concentrations.

Anti-Infective Agents↗

PubMed2003

Bacterial lipopolysaccharide decreases thrombomodulin expression in the sinusoidal endothelial cells of rats -- a possible mechanism of intrasinusoidal microthrombus formation and liver dysfunction.

BACKGROUND/AIMS: To elucidate the mechanism of liver dysfunction occurring in patients with sepsis, we evaluated the effect of bacterial lipopolysaccharide (LPS) on the expression of thrombomodulin (TM) in rat sinusoidal endothelial cells (SECs) and the therapeutic efficacy of exogenous recombinant TM. METHODS: We induced endotoxemia in rats by bolus intraperitoneal injection of LPS. TM antigen levels within tissues were assessed by immunohistochemistry. We measured TM in cultured SECs by enzyme immunoassay, functional analysis and real-time polymerase chain reaction (PCR). RESULTS: TM antigen and activity levels were significantly decreased in SECs isolated from LPS-treated rats after 3 and 6 h treatment, and recovered after 12 h treatment, correlating with immunohistochemical observations. In contrast, TM messenger RNA was decreased after 6 and 12 h treatment, and slightly recovered after 24 h treatment. TM expression in cultured SECs isolated from normal rats was also reduced after treatment with LPS and tumor necrosis factor (TNF)-alpha in vitro. The increased levels of serum fibrin degradation products (FDP), fibrin deposition within liver sinusoids, injury of SECs and liver dysfunction induced by LPS in our rat model was improved by recombinant TM treatment. CONCLUSIONS: Decreased TM expression in SECs of LPS-treated rats may result in intrasinusoidal microthrombus formation and subsequent liver dysfunction during sepsis.

Animals↗

PubMed2003

The assessment of three methods to verify tracheal tube placement in the emergency setting.

We studied prospectively the reliability of clinical methods, end-tidal carbon dioxide (ETCO(2)) detection, and the esophageal detector device (EDD) for verifying tracheal intubation in 137 adult patients in the emergency department. Immediately after intubation, the tracheal tube position was tested by the EDD and ETCO(2) monitor, followed by auscultation of the chest. The views obtained at laryngoscopy were classified according to the Cormack grade. Of the 13 esophageal intubations that occurred, one false-positive result occurred in the EDD test and auscultation. In the non-cardiac arrest patients (n=56), auscultation, the ETCO(2), and EDD test correctly identified 89.3, 98.2*, and 94.6%* of tracheal intubations, respectively (*, P<0.05 vs. the cardiac arrest patients). In the cardiac arrest patients (n=81), auscultation, the ETCO(2), and the EDD tests correctly identified 92.6**, 67.9, and 75.3% of tracheal intubations, respectively (**, P<0.05 vs. EDD and ETCO(2)). The frequencies of Cormack grade 1 or 2 were 83.9% in the non-cardiac arrest, and 95.1% in the cardiac arrest patients. In conclusion, the ETCO(2) monitor is the most reliable method for verifying tracheal intubation in non-cardiac arrest patients. During cardiac arrest and cardiopulmonary resuscitation, however, negative results by the ETCO(2) or the EDD are not uncommon, and clinical methods are superior to the use of these devices.

Aged↗

PubMed2003

9-Oxo-neoprocurcumenol from Curcuma aromatica (Zingiberaceae) as an attachment inhibitor against the blue mussel, Mytilus edulis galloprovincialis.

Neocurdione, isoprocurcumenol, and a new sesquiterpene, 9-oxo-neoprocurcumenol, were isolated from fresh rhizomes of Curcuma aromatica and Curcuma zedoaria (Zingiberaceae) as attachment inhibitors against the blue mussel, Mytilus edulis galloprovincialis. The structures of these compounds were elucidated on the basis of spectroscopic evidence.

Adhesiveness↗

PubMed2002

Analysis of fibrinogen gamma-chain truncations shows the C-terminus, particularly gammaIle387, is essential for assembly and secretion of this multichain protein.

To examine the role of the fibrinogen gamma chain in the assembly and secretion of this multichain protein, we synthesized a series of fibrinogen variants with truncated gamma chains, terminating between residues gamma379 and the C-terminus, gamma411. The variant fibrinogens were synthesized from altered gamma-chain complementary DNAs in cultured Chinese hamster ovary cells. Immunoassays of the culture media demonstrated that only those variants with gamma chain longer than 386 residues were secreted and that the concentration of fibrinogen decreased with the length of the gamma chain, from 1.4 microg/mL for normal fibrinogen to 0.39 microg/mL for gamma 387 fibrinogen. Immunoassays of cell lysates showed that all variant gamma chains were synthesized, although the levels varied significantly. For variants longer than 386 residues, levels decreased with length but remained near normal. In contrast, expression of the 4 variants with 386 residues or less was about 20-fold reduced. Quantitative reverse transcription-polymerase chain reaction demonstrated that the gamma-chain messenger RNA level was independent from chain length. Western blot analyses showed that lysates expressing variants with 387 residues or more contained species comparable to the known intermediates in fibrinogen assembly, including half-molecules. For shorter variants, these intermediates were not evident. We conclude that residues near the C-terminus of the gamma chain are essential for fibrinogen assembly, and more specifically, that gamma387 is critical. We propose that the loss of residue gamma387 destabilized the structure of gamma chain, preventing assembly of alphagamma and betagamma dimers, essential intermediates in the assembly of normal fibrinogen.

Amino Acid Sequence↗

PubMed2002

t(8;21;14)(q22;q22;q24) is a novel variant of t(8;21) with chimeric transcripts of AML1-ETO in acute myelogenous leukemia.

We report a male patient with acute myelogenous leukemia (AML; French-American-British M2) associated with AML1-ETO. Cytogenetic studies showed a complex karyotype including a novel translocation (8;21;14)(q22;q22;q24) in all analyzed cells. This three-way translocation was confirmed with spectral karyotyping. Reverse transcription-polymerase chain reaction analysis for AML1-ETO chimeric transcripts showed the presence of the fusion product with the expected size. Translocation (8;21;14)(q22;q22;q24) is a novel variant of t(8;21)(q22;q22), possibly having a common molecular pathogenetic mechanism.

Base Sequence↗