Contribution of NO synthases to neutrophil infiltration in the gastric mucosal lesions in rats with water immersion restraint stress

AbstractA decrease in constitutive NO synthase (cNOS) activity and an increase in inducible NO synthase (iNOS) activity occurred with an increase in myeloperoxidase (MPO) activity, an index of neutrophil infiltration, in the gastric mucosa of rats with water immersion restraint (WIR) stress. This increase in gastric mucosal MPO activity was enhanced by pretreatment with NG-monomethyl l-arginine, a non-selective NOS inhibitor, but was prevented with maintenance of gastric mucosal cNOS activity by pretreatment with aminoguanidine, a selective iNOS inhibitor. The MPO activity was negatively correlated with the cNOS activity in all WIR-stressed rats used (r=−0.723). These results suggest that a decrease in cNOS activity could contribute to an increase in neutrophil infiltration in the gastric mucosa of WIR-stressed rats

Design and Performance Tests of a Low Power DC Arcjet Thruster

This paper describes a quasi-one-dimensional flow model which can be used for the design of an arcjet thruster. Owing to the simplicity of the model, the performance characteristics of the thruster can be calculated easily for finding an optimum configuration suitable for various missions. In order to verify adequacy of the model, a thruster was fabricated and its performance characteristics were measured. The experimental results were compared with the calculation predicted with the model. Both are in satisfactory agreement, and it is concluded that this flow model is a useful tool for the design of the arcjet thruster

Endoscopic ultrasonography findings of pancreatic parenchyma for predicting subtypes of intraductal papillary mucinous neoplasms

Background and Aims: The subtypes of intraductal papillary mucinous neoplasms (IPMNs) are closely associated with the clinicopathological behavior and recurrence after surgical resection. However, there are no established non-invasive methods to confirm the subtypes of IPMNs without surgery. The aim of this study is to predict the subtypes of IPMNs using the findings of endoscopic ultrasonography (EUS). Methods: Sixty-two consecutive patients with IPMNs who underwent EUS before surgery were retrospectively reviewed. The following EUS findings were analyzed and their relationship with the subtypes was evaluated: diameter of the main pancreatic duct, cyst size, number of cysts, height of mural nodule, early chronic pancreatitis (CP) finding, fatty parenchyma and atrophic parenchyma. Results: The subtypes of IPMNs were as follows: gastric (G)-type 38 (61%), intestinal (I) -type 14 (23%) and pancreatobiliary (PB) -type 10 (16%). Fatty parenchyma was significantly associated with G-type (P Conclusions: The evaluation of EUS findings, especially focused on the pancreatic parenchyma, has the potential to predict the subtypes of IPMN

Mechanical strain attenuates cytokine-induced ADAMTS9 expression via transient receptor potential vanilloid type 1

The synovial fluids of patients with osteoarthritis (OA) contain elevated levels of inflammatory cytokines, which induce the expression of a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) and of the matrix metalloproteinase (MMP) in chondrocytes. Mechanical strain has varying effects on organisms depending on the strength, cycle, and duration of the stressor; however, it is unclear under inflammatory stimulation how mechanical strain act on. Here, we show that mechanical strain attenuates inflammatory cytokine-induced expression of matrix-degrading enzymes. Cyclic tensile strain (CTS), as a mechanical stressor, attenuated interleukin (IL)-1β and tumor necrosis factor (TNF)-α-induced mRNA expression of ADAMTS4, ADAMTS9, and MMP-13 in normal chondrocytes (NHAC-kn) and in a chondrocytic cell line (OUMS-27). This effect was abolished by treating cells with mechano-gated channel inhibitors, such as gadolinium, transient receptor potential (TRP) family inhibitor, ruthenium red, and with pharmacological and small interfering RNA-mediated TRPV1 inhibition. Furthermore, nuclear factor κB (NF-κB) translocation from the cytoplasm to the nucleus resulting from cytokine stimulation was also abolished by CTS. These findings suggest that mechanosensors such as the TRPV protein are potential therapeutic targets in treating OA

Accretion Rates of Planetesimals by Protoplanets Embedded in Nebular Gas

When protoplanets growing by accretion of planetesimals have atmospheres, small planetesimals approaching the protoplanets lose their energy by gas drag from the atmospheres, which leads them to be captured within the Hill sphere of the protoplanets. As a result, growth rates of the protoplanets are enhanced. In order to study the effect of an atmosphere on planetary growth rates, we performed numerical integration of orbits of planetesimals for a wide range of orbital elements and obtained the effective accretion rates of planetesimals onto planets that have atmospheres. Numerical results are obtained as a function of planetesimals' eccentricity, inclination, planet's radius, and non-dimensional gas-drag parameters which can be expressed by several physical quantities such as the radius of planetesimals and the mass of the protoplanet. Assuming that the radial distribution of the gas density near the surface can be approximated by a power-law, we performed analytic calculation for the loss of planetesimals' kinetic energy due to gas drag, and confirmed agreement with numerical results. We confirmed that the above approximation of the power-law density distribution is reasonable for accretion rate of protoplanets with one to ten Earth-masses, unless the size of planetesimals is too small. We also calculated the accretion rates of planetesimals averaged over a Rayleigh distribution of eccentricities and inclinations, and derived a semi-analytical formula of accretion rates, which reproduces the numerical results very well. Using the obtained expression of the accretion rate, we examined the growth of protoplanets in nebular gas. We found that the effect of atmospheric gas drag can enhance the growth rate significantly, depending on the size of planetesimals.Comment: 41 pages, 14 figures, accepted for publication in Icaru

A Radioimmunoassay for Rat Serum Corticosterone

A reliable radioimmunoassay for rat serum corticosterone has been developed. 25 μ1 of diluted serum (1:100) was assayed with a specific antiserum raised against corticosterone-21-hemisuccinate conjugated to bovine serum albumin. The within-assay and between-assay coefficients of variation were 7.1% and 13.9%, respectively. The mean serum corticosterone concentration was 65.3±6.0 ng/ml (n=10). The corticosterone level increased to 208.4 ±23.7 ng/ml after ACTH administration, and was suppressed to the limit of assay sensitivity after dexamethasone administration