Lower Response (lower + response)

Distribution by Scientific Domains

Terms modified by Lower Response

  • lower response rate

  • Selected Abstracts

    Lower antibody response to Porphyromonas gingivalis associated with immunoglobulin G Fc, receptor IIB polymorphism

    Y. Honma
    Background and Objective:, Human Fc,RIIB is one of the receptors for immunoglobulin G (IgG) and suppresses the activation of B lymphocytes through cross-linking with the B cell receptor via immune complexes. This function of Fc,RIIB is essential for the negative regulation of antibody production. Our previous study has demonstrated the gene polymorphism Fc,RIIB-I232T to be associated with periodontitis. The polymorphism Fc,RIIB-232T has been reported to inhibit B-cell antigen receptor signaling more effectively compared to Fc,RIIB-232I, while other groups concluded that Fc,RIIB-232T had no ability to inhibit activatory receptors. In this study, we examined whether Fc,RIIB-I232T polymorphism would change the IgG antibody response to the periodontopathic bacteria Porphyromonas gingivalis. Material and Methods:, Forty-seven patients with periodontitis were genotyped with the direct sequencing of genome DNA. Serum IgG and specific IgG subclass levels for the sonicate of P. gingivalis and the recombinant 40 kDa outer membrane protein (OMP) were determined. Results:, No significant difference in the total IgG level and IgG response to P. gingivalis sonicate were observed between sera from Fc,RIIB-232T carriers and non-carriers. The Fc,RIIB-232T carriers revealed a significantly lower IgG2 response to P. gingivalis 40 kDa OMP compared to non-carriers (p = 0.04, Mann,Whitney U -test). Lower responses of Fc,RIIB-232T carriers were also observed in specific IgG and IgG1 levels. The Fc,RIIB-232T carriers revealed a low level of IgG2 response to P. gingivalis 40 kDa OMP, even with a high average probing pocket depth. Conclusion:, These results suggest that association of the Fc,RIIB-232T allele with periodontitis might be related to the lower levels of antibody response to P. gingivalis. [source]

    Sensitive Biomimetic Sensor Based on Molecular Imprinting at Functionalized Indium Tin Oxide Electrodes

    ELECTROANALYSIS, Issue 16 2007
    Na Gao
    Abstract We initially report an electrochemical sensing platform based on molecularly imprinted polymers (MIPs) at functionalized Indium Tin Oxide Electrodes (ITO). In this research, aminopropyl-derivatized organosilane aminopropyltriethoxysilane (APTES), which plays the role of functional monomers for template recognition, was firstly self-assembled on an ITO electrode and then dopamine-imprinted sol was spin-coated on the modified surface. APTES which can interact with template dopamine (DA) through hydrogen bonds brought more binding sites located closely to the surface of the ITO electrode, thus made the prepared sensor more sensitive for DA detection. Potential scanning is presented to extract DA from the modified film, thus DA can rapidly and completely leach out. The affinity and selectivity of the resulting biomimetic sensor were characterized using cyclic voltammetry (CV). It exhibited an increased affinity for DA over that of structurally related molecules, the anodic current for DA oxidation depended on the concentration of DA in the linear range from 2×10,6 M to 0.8×10,3 M with a correlation coefficient of 0.9927. In contrast, DA-templated film prepared under identical conditions on a bare ITO showed obviously lower response toward dopamine in solution. It should be noted that potential scanning is a very effective approach for DA extraction, and surface modification of the electrochemical transducer with functional monomers is responsible for the development of MIPs-based highly sensitive biomimetic sensor. [source]

    Seasonal changes in the effects of elevated CO2 on rice at three levels of nitrogen supply: a free air CO2 enrichment (FACE) experiment

    Abstract Over time, the stimulative effect of elevated CO2 on the photosynthesis of rice crops is likely to be reduced with increasing duration of CO2 exposure, but the resultant effects on crop productivity remain unclear. To investigate seasonal changes in the effect of elevated CO2 on the growth of rice (Oryza sativa L.) crops, a free air CO2 enrichment (FACE) experiment was conducted at Shizukuishi, Iwate, Japan in 1998,2000. The target CO2 concentration of the FACE plots was 200 µmol mol,1 above that of ambient. Three levels of nitrogen (N) were supplied: low (LN, 4 g N m,2), medium [MN, 8 (1998) and 9 (1999, 2000) g N m,2] and high N (HN, 12 and 15 g N m,2). For MN and HN but not for LN, elevated CO2 increased tiller number at panicle initiation (PI) but this positive response decreased with crop development. As a result, the response of green leaf area index (GLAI) to elevated CO2 greatly varied with development, showing positive responses during vegetative stages and negative responses after PI. Elevated CO2 decreased leaf N concentration over the season, except during early stage of development. For MN crops, total biomass increased with elevated CO2, but the response declined linearly with development, with average increases of 32, 28, 21, 15 and 12% at tillering, PI, anthesis, mid-ripening and grain maturity, respectively. This decline is likely to be due to decreases in the positive effects of elevated CO2 on canopy photosynthesis because of reductions in both GLAI and leaf N. Up to PI, LN-crops tended to have a lower response to elevated CO2 than MN- and HN-crops, though by final harvest the total biomass response was similar for all N levels. For MN- and HN-crops, the positive response of grain yield (ca. 15%) to elevated CO2 was slightly greater than the response of final total biomass while for LN-crops it was less. We conclude that most of the seasonal changes in crop response to elevated CO2 are directly or indirectly associated with N uptake. [source]

    Management of hepatitis C; Report of the Consensus Meeting at the 45th Annual Meeting of the Japan Society of Hepatology (2009)

    Izumi Namiki
    The consensus meeting for the diagnosis, management and treatment for hepatitis C was held in 45th annual meeting for the Japan Society of Hepatology (JSH) in June 2009 where the recommendations and informative statements were discussed including organizers and presenters. The Several important informative statements and recommendations have been shown. This was the fourth JSH consensus meeting of hepatitis C, however, the recommendations have not been published in English previously. Thus, this is the first report of JSH consensus of hepatitis C. The rate of development of hepatocellular carcinoma (HCC) in HCV-infected patients in Japan is higher than in the USA, because the average age of the HCV-infected patients is greater and there are more patients with severe fibrosis of the liver than in the USA. In Japan, more than 60% of HCV-infected patients are genotype 1b infection, and they show lower response to perinterferon and ribavirin combination treatment. To improve the response rate is also an important issue in our country. To establish the original recommendations and informative statements to prevent the development of HCC is a very important issue in Japan. [source]

    Rectal sensorimotor characteristics in female patients with idiopathic constipation with or without paradoxical sphincter contraction

    C. E. J. Sloots
    Abstract, Patients with chronic constipation fulfilling the Thompson criteria can show paradoxical sphincter contraction. Aim of this study was to evaluate rectal sensorimotor characteristics in patients with constipation with or without paradoxical sphincter contraction. Thirty female patients with chronic constipation and 22 female controls were investigated with anal manometry and rectal barostat. Paradoxical sphincter contraction was shown with manometry as a paradoxical increase of anal pressure during straining. Visceral sensitivity and compliance were tested by intermittent and continuous pressure-controlled distension. Patients were classified according to their sensations and compliance into normal, hypersensitive, reduced compliant, insensitive or excessive compliant rectum. Postprandial rectal response (PRR) and phasic volume events (PVEs) were registered for 1 h after a 600-kCal meal. Paradoxical sphincter contraction was found in 13 (43%) patients. In these patients, rectal sensitivity scores were higher (P = 0.045) than in patients without paradoxical contractions, but rectal compliance was not different. In 90% of patients an abnormal rectal sensitivity or compliance was found: excessively compliant in 35%, reduced compliant in 10%, hypersensitive in 27% and hyposensitive in 17%. Both patients with constipation (11%; P = 0.042) and controls (25%; P = 0.002) exhibited the presence of a postprandial rectal response. This response was not significantly different between idiopathic constipation, paradoxical sphincter contraction and controls. Patients with rectal hypersensitivity had lower response than other patients (P = 0.04). Patients with constipation had fewer basal PVEs compared controls (P = 0.03). Postprandial PVEs increased in both patients (P = 0.014) and controls (P < 0.001). Postprandial rectal response and PVE were not different in patients with or without paradoxical sphincter contraction. A total of 90% of female patients with idiopathic constipation show an abnormality in rectal sensation or compliance. The postprandial rectal response was comparable between patients with constipation and controls, however, PVEs were diminished. Patients with paradoxical sphincter contraction had higher rectal sensitivity but an unaltered compliance and postprandial rectal response. Future trials should investigate whether the classification of rectal abnormalities in patients with constipation has clinical importance. [source]

    Detection of volatile organic compounds using a polythiophene derivative

    V. C. Gonçalves
    Abstract Conjugated polymers have been subject of great interest in the recent literature from both fundamental point of view and applied science perspective. Among the several types of conjugated polymers used in recent investigations, polythiophene and its derivatives have attracted considerable attention over the past 20,years due to their high mobility and other remarkable solid-state properties. They have potential applications in many fields, such as microelectronic devices, catalysts, organic field-effect transistors, chemical sensors, and biosensors. They have been studied as gas and volatile organic compounds (VOCs) sensors using different principles or transduction techniques, such as optical absorption, conductivity, and capacitance measurements. In this work, we report on the fabrication of gas sensors based on a conducting polymer on an interdigitated gold electrode. We use as active layer of the sensor a polythiophene derivative: poly (3-hexylthiophene) (P3HT) and analyzed its conductivity as response for exposure to dynamic flow of saturated vapors of six VOCs [n -hexane, toluene, chloroform, dichloromethane, methanol, and tetrahydrofuran (THF)]. Different responses were obtained upon exposure to all VOCs, THF gave the higher response while methanol the lower response. The influence of moisture on the measurements was also evaluated. [source]

    Cation-induced superoxide generation in tobacco cell suspension culture is dependent on ion valence

    PLANT CELL & ENVIRONMENT, Issue 11 2001
    T. Kawano
    Abstract There have been many reports suggesting the involvement of reactive oxygen species (ROS), including superoxide anion (O2.,), in salt stress. Herein, direct evidence that treatments of cell suspension culture of tobacco (Nicotiana tabacum L.; cell line, BY-2) with various salts of trivalent, divalent and monovalent metals stimulate the immediate production of O2., is reported. Among the salts tested, LaCl3 and GdCl3 induced the greatest responses in O2., production, whereas CaCl2 and MgCl2 showed only moderate effects; salts of monovalent metals such as KCl and NaCl induced much lower responses, indicating that there is a strong relationship between the valence of metals and the level of O2., production. As the valence of the added metals increased from monovalent to divalent and trivalent, the concentrations required for maximal responses were lowered. Although O2., production by NaCl and KCl required high concentrations associated with hyperosmolarity, the O2., generation induced by NaCl and KCl was significantly greater than that induced simply by hyperosmolarity. Since an NADPH oxidase inhibitor, diphenyleneiodonium chloride, showed a strong inhibitory effect on the trivalent and divalent cation-induced generation of O2.,, it is likely that cation treatments activate the O2., -generating activity of NADPH oxidase. [source]