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Biomedical subjects

Y Itoh

Publications and source records attributed to Y Itoh.

At least 109 records · Page 6Linked to original sources

Tectorigenin, an isoflavone of Pueraria thunbergiana Benth., induces differentiation and apoptosis in human promyelocytic leukemia HL-60 cells.

Cytotoxic effects of six isoflavonoids, tectorigenin, glycitein, tectoridin, glycitin, 6''-O-xylosyltectoridin, and 6''-O-xylosylglycitin isolated from the flower of Pueraria thunbergiana Benth. together with genistein, a known differentiation and apoptosis inducer, were examined. Among these isoflavonoids, tectorigenin and genistein exhibited cytotoxicity against various human cancer cells; glycitein showed only mild cytotoxicity. These results suggest that the isoflavone structure and 5-hydroxyl group are crucial for the cytotoxic properties and that glycosides are inactive. Moreover, tectorigenin induced differentiation of human promyelocytic leukemia HL-60 cells to granulocytes and monocytes/macrophages, and caused apoptotic changes of DNA in the cells, as did genistein. Tectorigenin also inhibited autophosphorylation of epidermal growth factor (EGF) receptor by EGF and decreased the expression of Bcl-2 protein, with less activity than genistein. From these results, tectorigenin may be a possible therapeutic agent for leukemia.

Anti-Inflammatory Agents, Non-Steroidal↗

A transgenic apple callus showing reduced polyphenol oxidase activity and lower browning potential.

Polyphenol oxidase (PPO) is responsible for enzymatic browning of apples. Apples lacking PPO activity might be useful not only for the food industry but also for studies of the metabolism of polyphenols and the function of PPO. Transgenic apple calli were prepared by using Agrobacterium tumefaciens carrying the kanamycin (KM) resistant gene and antisense PPO gene. Four KM-resistant callus lines were obtained from 356 leaf explants. Among these transgenic calli, three calli grew on the medium containing KM at the same rate as non-transgenic callus on the medium without KM. One callus line had an antisense PPO gene, in which the amount and activity of PPO were reduced to half the amount and activity in non-transgenic callus. The browning potential of this line, which was estimated by adding chlorogenic acid, was also half the browning potential of non-transgenic callus.

Agrobacterium tumefaciens↗

Strategy for determining racial and environmental similarities and differences for plasma proteins.

The aim of this protocol is to establish a common basis for the production of reference values and well-defined and documented reference intervals for plasma proteins, based on common standardization, using the IFCC/BCR/CAP Certified Reference Material CRM 470. The strategy is to search for racial and environmental/geographical similarities and sources of differences in order to describe the main causes for variability among smaller or larger groups in selected societies and to estimate the sizes of differences for the different proteins according to the investigated sources. For this purpose, groups of reference individuals are selected according to race and geographical/environmental location, e.g. African Americans and Caucasians from the US. The reference individuals are groups of approximately 160 healthy male blood donors, 20 to 60 years of age. Rule-out criteria are positivity for HIV, hepatitis B and C antibodies and blood hemoglobin below the lower reference limit. Exclusion in relation to different C-reactive protein (CRP) levels will be investigated. Coagulation, storage conditions, transport, and the procedure for thawing are specified. The laboratories undertaking the measurements must have adequate analytical performance, and calibration and quality of performance are defined and documented, together with recommended control materials and procedures. Statistical models for describing distributions and for comparing groups are described. It is recommended that the data be presented as reference limits with 90% confidence intervals of those limits.

Adult↗

Standardization of immunoassay for CRM-related proteins in Japan: from evaluating CRM 470 to setting reference intervals.

The Japan National Institute of Health (JNIH), in close collaboration with academic societies, commercial companies, and the Japan Society of Medical Technologists, has led in the attempt to standardize plasma protein assays since the mid 1980s. Under a framework of global standardization, they used WHO primary reference materials to reduce discrepancies in values reported for proteins assayed using different systems, thus laying the foundations for a protein immunoassay standardization system in Japan. With the introduction of CRM 470 in 1993, the Japanese Committee for Clinical Laboratory Standards (JCCLS) has taken the initiative in promoting the use of the new material and bringing about the re-evaluation of all systems of quality assurance in clinical laboratories. This eventually led to the establishment of reference intervals in Japanese populations of children and adults after preparation of assigned calibrators from CRM 470 for each assay system. Here we review the history of a series of projects carried out in Japan and describe several remaining problems, through which we will attempt to evaluate the potential value of protein immunoassay standardization.

Adult↗

Potentiometric responses of polymeric liquid membranes based on hydrophobic chelating agents to metal ions.

The effect of hydrophobicity of acidic chelating agents as sensing materials on the potentiometric responses of polymeric liquid membranes was investigated. The chelating agents tested were 8-quinolinol (HOx), dithizone (HDz), 1-(2-pyridylazo)-2-naphthol (PAN) and their alkylated analogues, 5-octyloxymethyl-8-quinolinol (HO8Q), di(phexylphenyl)thiocarbazone (C6HDz), 7-pentadecyloxy-1-(2-pyridylazo)-2-naphthol (C15PAN) and a series of N-alkylcarbonyl-N-phenylhydroxylamines (CnPHA, n = 3, 6, 9, 12). The distribution coefficients between membrane solvent and water were determined to evaluate the hydrophobicity of the agents. The potential-pH profiles of the membranes containing hydrophobic chelating agents demonstrated the generation of potentiometric responses, while less hydrophobic agents gave no response. A possible model for the generation of membrane potential is proposed. The charge separation is attained by the permselective uptake of metal cations by the chelating agent anion at membrane/solution interface, where the high hydrophobicity of the agent enables the anionic or deprotonated form of the agents to remain at the membrane/solution interface.

Journal Article↗

Effect of experimental fluoride-releasing tooth separator on acid resistance of human enamel in vitro.

This study aimed to investigate the fluoride-releasing ability of an experimental tooth separator consisting of polyurethane elastomer with tin fluoride and its effect on the acid resistance of human enamel. The tooth separator was set around an enamel slab and stored in de-ionized water for 10 days. The daily concentration of fluoride in the de-ionized water was measured. Then the enamel surface was artificially decalcified by a lactic acid buffer solution (pH 4.5) for 96 hours. The mineral density at the surface layer of the enamel was measured to evaluate the acid resistance. The fluoride release increased with the amount of fluoride in the separator, but decreased with the immersion time. Both the enamel area contacting with the separator and its surrounding area showed lower mineral loss and lesion depth compared with the controls (P < 0.05). It is suggested that the experimental tooth separator would release enough fluoride and improve the acid resistance of the enamel surface layer.

Absorptiometry, Photon↗

Effective plasma concentration of a novel Na+/Ca2+ channel blocker NS-7 for its cerebroprotective actions in rats with a transient middle cerebral artery occlusion.

The effect of a novel Na+/Ca2+ channel blocker NS-7 [4-(4-fluorophenyl)-2-methyl-6-(5-piperidinopentyloxy) pyrimidine hydrochloride] on the cerebral infarction, edema, and mortality was examined in rats with a transient middle cerebral artery occlusion (MCAO), and the effective plasma concentration of this compound for producing the cerebroprotective action was subsequently determined. MCA was occluded by inserting a thread through internal carotid artery for 2 h, and then recirculated for 6 h. NS-7 (0.125-1 mg/kg), when injected i.v. immediately after recirculation, significantly reduced the infarct volume as well as the cerebral edema. Delayed treatment with NS-7 at 1 h after recirculation produced an equivalent inhibition of the infarction, and was still effective, although to a lesser extent, when injected at 2 h but not 3 h after recirculation. Glycerol (4 g/kg) suppressed the cerebral edema but did not reduce the size of cerebral infarction in the cerebral cortex or striatum. Therefore, it is likely that the suppression of brain edema does not always lead to the reduction of the infarct size. NS-7 treated in combination with glycerol further decreased the water content in the occluded brain. Moreover, NS-7 significantly lowered the mortality observed up to 10 days after a transient MCAO. From these data, it is suggested that the presence of NS-7 in plasma during 1 to 3 h after recirculation is important for producing the neuroprotective action. To determine the pharmacologically effective plasma concentration of NS-7, the effect of continuous infusion of this compound on the cerebral infarction was examined. Infusion of NS-7 at 0.3 mg/kg over 2 h, starting immediately after recirculation, significantly reduced the infarct size. Its plasma concentration during 1 to 3 h was 14.5 to 28.5 ng/ml (36.9-72.3 nM). From these finding it is suggested that NS-7 has a potent anti-infarct action in addition to antiedema action in the rat transient MCAO model. Moreover, its effective plasma concentration was assumed to be 36.9 to 72.3 nM.

Animals↗

[Carinal resection for bronchogenic carcinoma].

The purpose of this study was to evaluate the results of carinal resection for bronchogenic carcinoma in our institute. From 1981 to 1999, 24 carinal resection were performed for squamous cell carcinoma (n = 19), adenoid cystic carcinoma (n = 2), small cell carcinoma (n = 1), adenocarcinoma (n = 1), and mucoepidermoid carcinoma (n = 1). Nineteen underwent sleeve pneumonectomy, 2 had carinal resection without lung resection, 2 had carinal resection with right middle and lower lobectomy, and 1 had wedge pneumonectomy. In the patients with sleeve or wedge pneumonectomy, there were 5 operative death and 3 patients had survived for more than 3 years. Two patients with low-grade malignant tumors underwent carinal resection without lung resection and survived more than 10 years. We believe that limited carinal resection for low-grade malignant tumors are safe and valuable procedure. Careful selection of patients with sleeve or wedge pneumonectomy is mandatory.

Adult↗

Role of platelet glycoprotein IIb/IIIa in ADP-activated platelet adhesion to aortic endothelial cells in vitro: observation with video-enhanced contrast microscopy.

Intravascular thrombus formation downstream of cerebral arterial occlusion may result in necrosis of ischemic tissue. To clarify the causative mechanisms, interaction between adenosine-5'-diphosphate (ADP)-activated platelets and cultured human aortic endothelial cells (HAEC) was examined by employing video enhanced contrast-differential interference contrast (VEC-DIC) microscopy. The numbers of (1) control/platelets, (2) ADP-activated platelets, (3) ADP-activated, anti-platelet GP Ibalpha antibody (GUR20-5)-treated platelets, and (4) ADP-activated, platelet GP IIb/IIa antagonist (TAK-029)-treated platelets, associated with HAEC after superfusion and wash-out were counted in visual fields of 30 x 30 microm2. Many ADP-activated platelets adhered to HAEC directly, while almost no platelets adhered to HAEC in the control. The adhesion was almost completely blocked by the GP IIb/IIIa antagonist, but not by GP Ibalpha antibody. We conclude that initial binding of ADP-activated platelets to HAEC is mediated by platelet GP IIb/IIIa in this in vitro system.

Adenosine Diphosphate↗

[Laboratory investigation on M-protein and its clinical application. 1. Introduction].

Monoclonal protein is the immunoglobulin and its fragments which are originated from a monoclonal clone of immunoglobulin synthesizing cell. It is an actually tumour marker for B cell lymphoproliferative disorders. It is also observed in non-lymphoproliferative disorders such as solid tumor, infection, and immunodeficiencies. Monoclonal gammopathy of undetermined significance(MGUS) can be defined as a state of pre-malignancies, especially development of myeloma should be carefully followed. The paper outlines a routine-based laboratory approach on monoclonal protein in relevance with its classification, laboratory methods and the related diseases, thus giving general orientations for the paper followed.

B-Lymphocytes↗

[A giant testicular tumor detected with dyspnea due to lung metastases: a case report].

A 19-year-old male presented with dyspnea. Clinical examination revealed the left infant-head-sized testicular tumor, multiple lung metastases and retroperitoneal bulky lymph node metastasis with marked elevation of serum lactic dehydrogenase (LDH) and alpha-fetoprotein. Left radical orchiectomy followed by the chemotherapy with etoposide and cisplatin (EP) for 4 cycles was performed. The tumor weighed 1,700 g, and was pathologically diagnosed as mixed germ cell tumor consisting of embryonal carcinoma and yolk sac tumor. After the treatment, the tumor markers were normalized with partial response (PR) of lung metastases and complete response (CR) of retroperitoneal lymph node metastasis. Thereafter, biopsy of lung metastases through video-assisted thoracoscopic surgery (VATS) was performed, and pathologically no viable cells were detected. Five months after the treatment, he was seized with convulsion due to brain metastasis with hemorrhage. Therefore, a surgical resection of brain metastasis and 2nd line chemotherapy with etoposide, ifosfamide and cisplatin (VIP) chemotherapy for 3 cycles was performed. The patient has been free of recurrence for 21 months after the 2nd line chemotherapy.

Adult↗

Membrane-type 5 matrix metalloproteinase is expressed in differentiated neurons and regulates axonal growth.

Expression of membrane-type (MT) 5 matrix metalloproteinase (MMP) in the mouse brain was examined. MT5-MMP was expressed in the cerebrum in embryos, but it declined after birth. In contrast, expression in the cerebellum started to increase postnatally and continued thereafter. The cells expressing MT5-MMP were postmitotic neurons that showed gelatinolytic activities. Specific expression of MT5-MMP was observed in the neurons but not in the glial cells when embryonal mouse carcinoma P19 cells were differentiated in vitro by retinoic acid treatment. Neurons isolated from dorsal root ganglia also expressed MT5-MMP, and it was localized at the edge of growth cone. Proteoglycans inhibit neurite extension and regulate synaptogenesis. The inhibitory effect of the proteoglycans on neurite extension of dorsal root ganglia neurons was effectively eliminated by recombinant MT5-MMP. Thus, MT5-MMP expressed in neurons may play a role in axonal growth that contributes to the regulation of neural network formation.

Animals↗

[The present status of standardization in serum total PSA measurement--a result of "Survey 2000" conducted by PSA ad hoc Committee of Japanese Urological Association].

Immunoassays for serum total PSA are classified into two categories; equimolar and skewed, according to their response to free PSA and ACT-PSA. The analytical survey conducted in 1997 ("Survey 1997") revealed that more than a half of the kits displayed a skewed response which caused inter-assay variability as a major factor. PSA ad hoc committee of Japanese Urological Association chaired by Prof. H. Yamanaka carried out a survey in 2000 ("Survey 2000") in which 26 kits were participated from 18 manufacturers. Comparing with 1997, the inter-kit variability, on the whole, was remarkably reduced in 2000. The dilution tests using purified samples of free PSA and ACT-PSA elucidated that five sixths of the kits were counted to be equimolar (12; completely equimolar, 10; nearly equimolar or slightly skewed, 4; skewed). Immunological behavior of the assays to free PSA and ACT-PSA in serum samples was also markedly improved, in which free PSA content ranged to 50%. Conversion of data measured by each kit to those of Tandem-R was capable in 19 kits. The remaining 7 kits were out of interchangeability, however, a measure of improvement or withdrawal of these kits would be in progress by the corresponding manufacturers. Total PSA assay is certainly going on toward standardization.

Biomarkers, Tumor↗