822 research outputs found
The inhibitory effect against collagen-induced arthritis by Schistosoma japonicum infection is infection stage-dependent
<p>Abstract</p> <p>Background</p> <p>A long-term existing schistosome infection can aid in maintaining immuno-homeostasis, thus providing protection against various types of autoimmune diseases to the infected host. Such benefits have often been associated with acute or egg stage infection and with the egg-induced Th2 response. However, since schistosome infection undergoes different stages, each associated with a specific induction of Th responses, the requirements for the ability of the different stages of schistosome infection to protect against autoimmune disease has not been elucidated. The present study was designed to study whether different stages of schistosome infection offer unique protection in collagen-induced arthritis and its mechanisms.</p> <p>Results</p> <p>Arthritis susceptible strain DBA/1 male mice were infected with <it>Schistosoma japonicum </it>for either 2 weeks resulting in early stage infection or for 7 weeks resulting in acute or egg stage infection. Following <it>Schistosoma japonicum </it>infection, collagen II was administered to induce collagen-induced arthritis, an animal model for human rheumatoid arthritis. Infection by <it>Schistosoma japonicum </it>significantly reduced the severity and the incidence of experimental autoimmune collagen-induced arthritis. However, this beneficial effect can only be provided by a pre-established acute stage of infection but not by a pre-established early stage of the infection. The protection against collagen-induced arthritis correlated with reduced levels of anti-collagen II IgG, especially the subclass of IgG2a. Moreover, in protected mice increased levels of IL-4 were present at the time of collagen II injection together with sustained higher IL-4 levels during the course of arthritis development. In contrast, in unprotected mice minimal levels of IL-4 were present at the initial stage of collagen II challenge together with lack of IL-4 induction following <it>Schistosoma japonicum </it>infection.</p> <p>Conclusion</p> <p>The protective effect against collagen-induced arthritis provided by <it>Schistosoma japonicum </it>infection is infection stage-dependent. Furthermore, the ability of schistosomiasis to negatively regulate the onset of collagen-induced arthritis is associated with a dominant as well as long-lasting Th2 response at the initiation and development of autoimmune joint and systemic inflammation.</p
Ultrasound-assisted degradation of a new bacterial exopolysaccharide WL-26 from Sphingomonas sp.
Ultrasonic degradation of a new exopolysaccharide WL-26 from Sphingomonas sp. was made over the frequency range 200 to 1200 Hz and polymer concentrations of 3, 5, 10 and 20 g/L using high performance anion exchange pulsed-amperometric detection chromatography (HPAEC–PAD) and infrared spectroscopy. Sonication was more efficient with less concentrated polysaccharide solutions, high ultrasonic frequency, long duration of ultrasonic irradiation and degradation continued until a limiting molecular weight was attained. Results show that HPAEC–PAD revealed WL-26 to be an acidic polysaccharide composed of rhamnose, glucose, mannose, galactose and glucuronic acid in the molar ratio of 10:9:3:1:3 distinctly different from welan gum which does not contain galactose.Key words: Exopolysaccharide WL-26, ultrasonic degradation, infrared spectroscopy
Differences and Similarities in the Clinicopathological Features of Pancreatic Neuroendocrine Tumors in China and the United States: A Multicenter Study
The presentation, pathology, and prognosis of pancreatic neuroendocrine tumors (PNETs) in Asian patients have not been studied in large cohorts. We hypothesized that the clinicopathological features of PNETs of Chinese patients might be different from those of US patients. The objectives of this study were to address whether PNETs in Chinese patients exhibit unique clinicopathological features and natural history, and can be graded and staged using the WHO/ENETS criteria. This is a retrospective review of medical records of patients with PNETs in multiple academic medical centers in China (7) and the United States (2). Tumor grading and staging were based on WHO/ENETS criteria. The clinicopathological features of PNETs of Chinese and US patients were compared. Univariate and multivariate analyses were performed to find associations between survival and patient demographics, tumor grade and stage, and other clinicopathological characteristics. A total of 977 (527 Chinese and 450 US) patients with PNETs were studied. In general, Chinese patients were younger than US patients (median age 46 vs 56 years). In Chinese patients, insulinomas were the most common (52.2%), followed by nonfunctional tumors (39.7%), whereas the order was reversed in US patients. Tumor grade distribution was similar in the 2 countries (G1: 57.5% vs 55.0%; G2: 38.5% vs 41.3%; and G3: 4.0% vs 3.7%). However, age, primary tumor size, primary tumor location, grade, and stage of subtypes of PNETs were significantly different between the 2 countries. The Chinese nonfunctional tumors were significantly larger than US ones (median size 4 vs 3 cm) and more frequently located in the head/neck region (54.9% vs 34.8%). The Chinese and US insulinomas were similar in size (median 1.5 cm) but the Chinese insulinomas relatively more frequently located in the head/neck region (48.3% vs 26.1%). Higher grade, advanced stage, metastasis, and larger primary tumor size were significantly associated with unfavorable survival in both countries. Several clinicopathological differences are found between Chinese and US PNETs but the PNETs of both countries follow a similar natural history. The WHO tumor grading and ENETS staging criteria are applicable to both Chinese and US patients
Measurement of the Branching Fraction of J/psi --> pi+ pi- pi0
Using 58 million J/psi and 14 million psi' decays obtained by the BESII
experiment, the branching fraction of J/psi --> pi+ pi- pi0 is determined. The
result is (2.10+/-0.12)X10^{-2}, which is significantly higher than previous
measurements.Comment: 9 pages, 8 figures, RevTex
Search for K_S K_L in psi'' decays
K_S K_L from psi'' decays is searched for using the psi'' data collected by
BESII at BEPC, the upper limit of the branching fraction is determined to be
B(psi''--> K_S K_L) < 2.1\times 10^{-4} at 90% C. L. The measurement is
compared with the prediction of the S- and D-wave mixing model of the
charmonia, based on the measurements of the branching fractions of J/psi-->K_S
K_L and psi'-->K_S K_L.Comment: 5 pages, 1 figur
First observation of psi(2S)-->K_S K_L
The decay psi(2S)-->K_S K_L is observed for the first time using psi(2S) data
collected with the Beijing Spectrometer (BESII) at the Beijing Electron
Positron Collider (BEPC); the branching ratio is determined to be
B(psi(2S)-->K_S K_L) = (5.24\pm 0.47 \pm 0.48)\times 10^{-5}. Compared with
J/psi-->K_S K_L, the psi(2S) branching ratio is enhanced relative to the
prediction of the perturbative QCD ``12%'' rule. The result, together with the
branching ratios of psi(2S) decays to other pseudoscalar meson pairs
(\pi^+\pi^- and K^+K^-), is used to investigate the relative phase between the
three-gluon and the one-photon annihilation amplitudes of psi(2S) decays.Comment: 5 pages, 4 figures, 2 tables, submitted to Phys. Rev. Let
Study of psi(2S) decays to X J/psi
Using J/psi -> mu^+ mu^- decays from a sample of approximately 4 million
psi(2S) events collected with the BESI detector, the branching fractions of
psi(2S) -> eta J/psi, pi^0 pi^0 J/psi, and anything J/psi normalized to that of
psi(2S) -> pi^+ pi^- J/psi are measured. The results are B(psi(2S) -> eta
J/psi)/B(psi(2S) -> pi^+ pi^- J/psi) = 0.098 \pm 0.005 \pm 0.010, B(psi(2S) ->
pi^0 pi^0 J/psi)/B(psi(2S) -> pi^+ pi^- J/psi) = 0.570 \pm 0.009 \pm 0.026, and
B(psi(2S) -> anything J/psi)/B(psi(2S) -> pi^+ pi^- J/psi) = 1.867 \pm 0.026
\pm 0.055.Comment: 13 pages, 8 figure
Observation of the decay \psip\rar\kstark
Using 14 million events collected with the BESII detector,
branching fractions of \psip\rar\kstarkpm and \kstarknn are determined to
be: \calB(\psip\rar\kstarkpm)=(2.9^{+1.3}_{-1.7}\pm0.4)\times 10^{-5} and
\calB(\psip\rar\kstarknn)=(13.3^{+2.4}_{-2.7}\pm1.9)\times 10^{-5}. The
results confirm the violation of the "12%" rule for these two decay channels
with higher precision. A large isospin violation between the charged and
neutral modes is observed.Comment: 5 pages, 3 figure
\psi(2S) Decays into \J plus Two Photons
Using \gamma \gamma J/\psi, J/\psi \ra e^+ e^- and events
from a sample of \psip decays collected with the BESII
detector, the branching fractions for \psip\ra \pi^0\J, \eta\J, and
\psi(2S)\ar\gamma\chi_{c1},\gamma\chi_{c2}\ar\gamma\gamma\jpsi are measured
to be B(\psip\ra \pi^0\J) = (1.43\pm0.14\pm0.13)\times 10^{-3}, B(\psip\ra
\eta\J) = (2.98\pm0.09\pm0.23)%,
B(\psi(2S)\ar\gamma\chi_{c1}\ar\gamma\gamma\jpsi) = (2.81\pm0.05\pm 0.23)%,
and B(\psi(2S)\ar\gamma\chi_{c2}\ar\gamma\gamma\jpsi) = (1.62\pm0.04\pm
0.12)%.Comment: 7 pages, 6 figures. submitted to Phys. Rev.
Search for the Lepton Flavor Violation Processes and
The lepton flavor violation processes and are
searched for using a sample of 5.8 events collected with
the BESII detector. Zero and one candidate events, consistent with the
estimated background, are observed in and
decays, respectively. Upper limits on the branching ratios are determined to be
and at the 90% confidence level (C.L.).Comment: 9 pages, 2 figure
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