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Biomedical subjects

Y Matsushita

Publications and source records attributed to Y Matsushita.

At least 19 recordsLinked to original sources

Prediction of pharmacokinetics of CS-023 (RO4908463), a novel parenteral carbapenem antibiotic, in humans using animal data.

The pharmacokinetics of CS-023 (RO4908463, formerly R-115685), a novel parenteral carbapenem antibiotic, in humans was successfully predicted using the data collected from mice, rats, rabbits, and dogs; while inclusion of the monkey data led to a significant underestimation of the total plasma clearance (CL). Double logarithmic plots of CL and distribution volume at the steady-state (Vss) vs. body weight in four animal species were linear with high correlation coefficients; and the predicted CL and Vss values in humans agreed well with the observed values after administration of CS-023 by an intravenous drip infusion for 30 min. The plasma concentration-time profile in humans, which was predicted using a bi-exponential equation fitted to a complex Dedrick plot of the animal data, approximated the observed profile. An underestimation of CL caused by including the monkey data in a prediction is quite likely due to the net tubular reabsorption in monkeys, but not at least in rabbits, dogs, and humans.

Animals↗

Involvement of brain protein kinase C in nitrous oxide-induced antinociception in mice.

Exposure of mice to the anesthetic gas nitrous oxide (N(2)O) produces a marked antinociceptive effect. Protein kinase C is a key regulatory enzyme that may be targeted by general anesthetics. However, a relationship between N(2)O-induced antinociception and protein kinase C has yet to be established. The present study was conducted to identify whether protein kinase C might influence N(2)O-induced antinociception in mice. Regular exposure (11 min) to N(2)O produced concentration-dependent antinociception in mice, as determined using the abdominal constriction test. N(2)O-induced antinociception was attenuated by i.c.v. pretreatment with phorbol 12,13-dibutyrate, a protein kinase C activator. This phorbol 12,13-dibutyrate antagonism of N(2)O-induced antinociception was reversed by i.c.v. pretreatment with calphostin C, a protein kinase C inhibitor. Long-term exposure (41 min in total, including 30 min prior to, and 11 min of analgesic testing) to 70% N(2)O produced reduced analgesic effects, compared with regular exposure to 70% N(2)O, thus indicating acute tolerance to N(2)O-induced antinociception. However, mice pretreated with calphostin C, chelerythrine, which is another protein kinase C inhibitor, and phorbol 12,13-dibutyrate, did not develop acute tolerance. Regarding activation of protein kinase C, regular exposure to 70% N(2)O did not increase protein kinase C within the membrane fraction of brain tissue, as determined by immunoblot analysis, but long-term exposure to 70% N(2)O did. The i.c.v. pretreatment with calphostin C and phorbol 12,13-dibutyrate prevented the increase in protein kinase C observed with long-term exposure to 70% N(2)O. These results suggest that brain protein kinase C negatively regulates the antinociceptive effect of N(2)O, and that activation of brain protein kinase C is related to the development of acute tolerance to N(2)O-induced antinociception in mice.

Analgesics↗

Heavy-fermion-like state in a transition metal oxide LiV2O4 single crystal: indication of Kondo resonance in the photoemission spectrum.

We have performed a vacuum ultraviolet laser excited photoemission spectroscopy on a d-electron heavy-fermion-like material LiV2O4 single crystal. We observed a sharp peak structure in the density of states at approximately 4 meV above the Fermi level (E(F)). The evolution of the peak height corresponds well with the crossover behavior to the heavy-fermion-like state as observed in the thermal and transport properties. The position, shape, and temperature (T) dependence of the peak structure is quite similar to the Kondo resonance observed in conventional f-electron heavy Fermion compounds.

Journal Article↗

Renal handling of CS-023 (RO4908463), a novel parenteral carbapenem antibiotic, in rabbits in comparison with meropenem.

The plasma half-life of CS-023 (RO4908463), a novel parenteral carbapenem antibiotic, is longer than that of meropenem in animals and humans. To address this issue, renal clearance studies were conducted in rabbits. A constant rate infusion of CS-023 and meropenem was conducted in male Japanese White rabbits. Concentrations in the plasma, urine and renal cortex were measured to evaluate renal clearance and renal tissue uptake. CS-023 showed a clearance ratio (renal clearance/glomerular filtration rate) of around 1, which was not affected by co-administration of probenecid or p-aminohippurate. On the other hand, meropenem exhibited a clearance ratio of around 3, which was significantly decreased to 1 by co-administration of probenecid. p-Aminohippurate, in contrast, had no effect. The renal cortex/plasma concentration ratio of CS-023 was around 0.6 with or without probenecid co-administration. This ratio of meropenem was around 3, which was decreased significantly by co-administration of probenecid to around 0.6. These data suggest that meropenem is secreted in the renal tubules via organic anion transporters, but CS-023 is not. The present findings in rabbits would indicate that a lack of renal tubular secretion of CS-023 is a reason for the long plasma half-life compared with meropenem.

Animals↗

Regulation of local and metastatic host-mediated anti-tumour mechanisms by L-selectin and intercellular adhesion molecule-1.

Malignant melanoma is often accompanied by a host response of inflammatory cell infiltration that is highly regulated by multiple adhesion molecules. To assess the role of adhesion molecules, including L-selectin and intercellular adhesion molecule-1 (ICAM-1), in this process, subcutaneous primary growth and metastasis to the lung of B16 melanoma cells not expressing L-selectin, ICAM-1 or their ligands were examined in mice lacking L-selectin, ICAM-1 or both. Primary subcutaneous growth of B16 melanoma was augmented by loss of L-selectin, ICAM-1 or both, while pulmonary metastasis was enhanced by the loss of L-selectin or combined loss of L-selectin and ICAM-1. In both situations, the combined loss of L-selectin and ICAM-1 exhibited the greatest effect. This enhancement was associated generally with a reduced accumulation of natural killer (NK) cells, CD4+ T cells and CD8+ T cells and also with a diminished release of interferon (IFN)-gamma and tumour necrosis factor (TNF)-alpha but not interleukin (IL)-6. Cytotoxicity against melanoma was not defective by the absence of ICAM-1, L-selectin or both, suggesting that the enhancement of tumour growth and metastasis caused by the loss of adhesion molecules results from an impaired migration of effector cells into the tissue rather than from a suppression of the cytotoxic response. The results indicate that L-selectin and ICAM-1 contribute co-operatively to the anti-tumour reaction by regulating lymphocyte infiltration to the tumour.

Animals↗

Direct RT-PCR method for detecting two chrysanthemum viroids using minimal amounts of plant tissue.

A direct reverse transcription-polymerase chain reaction (RT-PCR) method for detecting the chrysanthemum stunt viroid (CSVd) and chrysanthemum chlorotic mottle viroid (CChMVd) to screen for a viroid-free chrysanthemum plant at a small plant size was established and named microtissue direct RT-PCR. A razor or syringe needle was used for RNA template preparations. Under a stereoscopic microscope, a razor or syringe needle was used to pierce, a tissue sample to a depth of 0.1-0.2mm, and the sample was directly transferred to the RT mixtures. Methods using razors or needles for the preparation of templates could detect CSVd and CChMVd with a high sensitivity. The most sensitive method used a razor or syringe needle to acquire template from the shoot tips. Using the microtissue direct RT-PCR method, both viroids could be detected from the high- and low-viroid-concentration plants. The microtissue direct RT-PCR method was more sensitive than a conventional template preparation method. Using the microtissue direct RT-PCR method established in this study, the laborious subculture step could be omitted because detecting viroids and screening for viroid-free plants even at a small plant size before the subculture could be possible. In addition, the microtissue direct RT-PCR method could also be a powerful tool for clarifing the viroid distribution among microtissues, such as shoot apical meristems.

Chrysanthemum↗

Evidence for charge Kondo effect in superconducting Tl-doped PbTe.

We report results of low-temperature thermodynamic and transport measurements of Pb1-xTlxTe single crystals for Tl concentrations up to the solubility limit of approximately x=1.5%. For all doped samples, we observe a low-temperature resistivity upturn that scales in magnitude with the Tl concentration. The temperature and field dependence of this upturn are consistent with a charge Kondo effect involving degenerate Tl valence states differing by two electrons, with a characteristic Kondo temperature T(K) approximately 6 K. The observation of such an effect supports an electronic pairing mechanism for superconductivity in this material and may account for the anomalously high T(c) values.

Journal Article↗

Autoantibodies directed against the protease inhibitor calpastatin in psoriasis.

Psoriasis is believed to be a T cell-mediated autoimmune disease, but also exhibits autoantibody production. Calpastatin is an endogenous inhibitor of calpain, a ubiquitous protease that regulates inflammatory processes. Anti-calpastatin autoantibody was first identified as an autoantibody specific to rheumatoid arthritis, but has been also detected in other autoimmune diseases. In this study, we examined the presence and levels of anti-calpastatin antibody in 77 psoriasis patients by enzyme-linked immunosorbent assay. Compared with normal controls, psoriasis patients exhibited significantly elevated IgG anti-calpastatin antibody levels that were similar to those found in rheumatoid arthritis patients. Remarkably, IgG anti-calpastatin autoantibody in sera from psoriasis patients inhibited calpastatin activity. Calpain II expression was up-regulated in psoriasis skin lesions compared with normal skin while calpastatin expression was normal. The results of this study reveal the presence of anti-calpastatin autoantibody in psoriasis.

Adult↗

Chain elongation suppression of cyclic block copolymers in lamellar microphase-separated bulk.

Chain elongation suppression of cyclic block copolymers in microphase-separated bulk was determined quantitatively. Solvent-cast and annealed films are confirmed to show alternating lamellar structure and their microdomain spacing D increases with increasing total molecular weight M according to the relationship D proportional, variant M0.59, which agrees quite consistently with the theoretically predicted power law, i.e., D proportional, variant M3/5. This result is in contrast to the well-established issue for linear block copolymers, where the relationship D proportional, variant M2/3 has been confirmed to hold both experimentally and theoretically. This means that chain elongation of each component block is suppressed considerably, owing to their looped conformation in strongly segregated bulk.

Journal Article↗

[Pulmonary thromboendarterectomy for an elderly patient].

We describe a case of successful pulmonary thromboendarterectomy for an elderly patient. A 75-year-old female suffered from severe dyspnea in spite of administration of pulmonary vascular dilators and anticoagulants. Her pulmonary vascular resistance was 545 dyn x sec x cm(-5) and, her pulmonary angiogram and perfusion scan revealed that almost all branches of her right pulmonary artery were occluded. Pulmonary thromboendarterectomy was performed under cardiopulmonary bypass. A videoscope was employed to see inside of the pulmonary artery. Flexible aspirator chip was used to peed abnormal intima easily. A non-invasive intracranial oxygen saturation monitor was used for secure circulatory arrest. The duration of cardiopulmonary bypass was 101 minutes and minimum body temperature was 24.5 degrees C. Her symptoms improved markedly after operation, and she went back to the ordinary life. Pulmonary thromboendarterectomy was useful even for elderly patients under some modifications of the operative procedures.

Aged↗

alpha- and beta-A2Hg3M2S8 (A = K, Rb; M = Ge, Sn): polar quaternary chalcogenides with strong nonlinear optical response.

The closely related phases alpha- and beta-A(2)Hg(3)M(2)S(8) (A = K, Rb; M = Ge, Sn) have been discovered using the alkali polychalcogenide flux method and are described in detail. They present new structure types with a polar noncentrosymmetric crystallographic motif and strong nonlinear second-harmonic generation (SHG) properties. The alpha-allotropic form crystallizes in the orthorhombic space group Aba2 with a = 19.082(2) A, b = 9.551(1) A, c = 8.2871(8) A for the K(2)Hg(3)Ge(2)S(8) analogue, and a = 19.563(2) A, b = 9.853(1) A, c = 8.467(1) A for the K(2)Hg(3)Sn(2)S(8) analogue. The beta-form crystallizes in the monoclinic space group C2 with a = 9.5948(7) A, b = 8.3608(6) A, c = 9.6638(7) A, beta = 94.637 degrees for the K(2)Hg(3)Ge(2)S(8) analogue. The thermal stability and optical and spectroscopic properties of these compounds are reported along with detailed solubility and crystal growth studies of the alpha-Kappa(2)Hg(3)Ge(2)S(8) in K(2)S(8) flux. These materials are wide gap semiconductors with band gaps at approximately 2.40 and approximately 2.64 eV for the Sn and Ge analogues, respectively. Below the band gap the materials exhibit a very wide transmission range to electromagnetic radiation up to approximately 14 microm. alpha-K(2)Hg(3)Ge(2)S(8) shows anisotropic thermal expansion coefficients. SHG measurements, performed with a direct phase-matched method, showed very high nonlinear coefficient d(eff) for beta-K(2)Hg(3)Ge(2)S(8) approaching 20 pm/V. Crystals of K(2)Hg(3)Ge(2)S(8) are robust to air exposure and have a high laser-damage threshold.

Journal Article↗

Melanoma inhibitory activity (MIA) as a serum marker for early detection of post-surgical relapse in melanoma patients: comparison with 5-S-cysteinyldopa.

One of the principal applications of tumour markers is the early detection of recurrent disease in the follow-up of patients. In the study described here, we compared the usefulness of two serum markers for melanoma, 5-S-cysteinyldopa (5-S-CD) and melanoma inhibitory activity (MIA), in the monitoring of postsurgical melanoma patients. A total of 154 serum samples taken from 45 melanoma patients, who underwent surgery of the primary tumour and were under periodical follow-up for 13 to 180 months, were analysed. Serum MIA measurements were performed using an enzyme-linked immunosorbent assay (ELISA), and 5-S-CD levels were determined using high performance liquid chromatography (HPLC). In 72 serum samples taken from a group of 31 non-progressive patients with a median follow-up of 48.5 months, false positive rates of both markers were equally low, being 6.9% (five out of 72) for 5-S-CD and 8.3% (six out of 72) for MIA. In contrast, the sensitivity of MIA at the time point of the first clinical relapse in 14 progressive patients was significantly greater than that of 5-S-CD (0.64 [nine out of 14] versus 0.21 [three out of 14]; P < 0.05). Furthermore, seven patients showed abnormal serum MIA values 4-53 months prior to the clinical detection of metastasis, and the elevated levels were often noted on multiple occasions. These results show that MIA was superior to 5-S-CD in monitoring melanoma patients under periodical follow-up after the primary surgery. Repeated elevation of serum MIA levels may predict the presence of clinically undetectable occult metastases, which warrants further prospective investigations to assess the prognostic significance of serum MIA levels in postsurgical melanoma patients.

Aged↗

Pharmacological studies on Puerariae Flos. IV: Effects of Pueraria thomsonii dried flower extracts on blood ethanol and acetaldehyde levels in humans.

We investigated the effects of extracts from the dried flower of Pueraria thomsonii on blood ethanol and acetaldehyde levels in humans consuming alcoholic beverages. The extracts of Pueraria thomsonii had no influence on blood ethanol and acetaldehyde concentration in humans. However, the extracts increased the elimination rate constant of blood acetaldehyde, although they had no effect on the elimination of blood ethanol in humans. These results suggest that Pueraria thomsonii promotes the elimination of blood acetaldehyde in humans. The present study clinically suggests that a modest stimulatory effect of Pueraria thomsonii on the elimination of blood acetaldehyde may passively mitigate acetaldehyde toxicity, such as flushing, palpitation, headache, etc., associated with excessive alcohol intake.

Acetaldehyde↗

The tomato mosaic tobamovirus movement protein interacts with a putative transcriptional coactivator KELP.

Viral movement through plasmodesmata in host plants likely depends on the interaction between virus-encoded movement protein (MP) and host proteins. In order to search for MP-interacting protein (MIP), we carried out far-western screening of a Brassica campestris cDNA library using a recombinant MP of tomato mosaic tobamovirus (ToMV) as a probe. One of the positive clones, designated MIP102, was found to be a putative orthologue for a transcriptional coactivator KELP of Arabidopsis thaliana. In vitro analysis with recombinant proteins revealed that ToMV MP could bind to KELP proteins that are derived from different plant species. At least 31 amino acids from the carboxyl-terminus of ToMV MP were dispensable for the interaction with KELP. Other MPs, derived from crucifer tobamovirus CTMV-W and cucumber mosaic cucumovirus, also exhibited comparable binding abilities. This suggests that these MPs could commonly interact with KELP, possibly to modulate the host gene expression.

Amino Acid Sequence↗

Results of surgery and radio-hyperthermo-chemotherapy for patients with soft-tissue sarcoma.

BACKGROUND: Between 1990 and 1999, we performed radio-hyperthermo-chemotherapy (RHC) in 44 patients with high-grade soft-tissue sarcomas of the limbs. METHODS: Radiotherapy involved the delivery of radiation at a dose of 2 Gy once daily on 16 days, to give a total dose of 32 Gy. Hyperthermia was conducted once a week, with a total of five sessions. Chemotherapy was performed by implanting a reservoir and administering cisplatin (3 mg/kg) three times, and pinorubin (an adriamycin derivative; 1 mg/kg) twice by intra-arterial infusion, at weekly intervals. These drugs were administered alternately during hyperthermia sessions. RESULTS: Tumor shrinkage was observed in 98% (43/44) of the patients. Of the 36 patients with M0 tumors, 30 were disease-free at final follow-up, 2 had no evidence of disease, 1 was alive with disease, and 3 had died of the disease. Amputation was required only in the first patient, and the affected limb was preserved in the other 43 patients. The surgical margin was wide in 9 patients and marginal in 29 patients, and intralesional excision was performed in 5 patients. There was recurrence in only 1 of the 44 patients. CONCLUSION: RHC is currently the most potent and relatively safe treatment method for high-grade soft-tissue sarcomas that is available clinically.

Adolescent↗

A new treatment of aneurysmal bone cyst by endoscopic curettage without bone grafting.

Curettage and bone grafting are the accepted methods of treatment of aneurysmal bone cysts. Unfortunately, recurrence is common. We treated 4 patients with atypical aneurysmal bone cysts that lacked aneurysmal dilatation by endoscopic curettage without bone grafting. New bone formation and remodeling were observed in all patients. In the patients in whom the follow-up was longer than 30 months, there was no evidence of recurrence. Endoscopic curettage without bone grafting is a simple and effective treatment for aneurysmal bone cysts.

Adolescent↗

The molecular characterization and in situ expression pattern of pea SCARECROW gene.

Certain mutants of shoot gravitropism were reported to be ascribed to the SCR and SHR loci in Arabidopsis thaliana. The SCR gene was known to regulate the development of endodermis cells that are responsible for sensing gravity in a shoot. With the aim of elucidating the molecular mechanism for gravitropic responses in pea seedlings, we have isolated a putative pea SCR ortholog from a shoot cDNA library. Analyses of the cDNA clones revealed the structure of a full-length ORF coding for 819 amino acid residues. A remarkable feature of pea SCR protein was the presence of asparagine stretches at the N-terminal transcriptional activation domain, which was distinct from the occurrence of glutamine or alanine stretches in the Arabidopsis or maize SCR. A Northern blot analysis revealed a single 3.2-kb pea SCR transcript in addition to a closely related 2.5-kb transcript. Our in situ hybridization data indicated that pea SCR mRNA accumulated in the shoot apical meristem, leaf primordia and a root single cell layer corresponding to the endodermis. The expression patterns were similar to those reported for A. thaliana and Zea mays, suggesting that SCR may be functionally conserved among plants and involved in the differentiation of the endodermis.

Amino Acid Sequence↗