308 research outputs found
Atomic ionization by sterile-to-active neutrino conversion and constraints on dark matter sterile neutrinos with germanium detectors
The transition magnetic moment of a sterile-to-active neutrino conversion
gives rise to not only radiative decay of a sterile neutrino, but also its
non-standard interaction (NSI) with matter. For sterile neutrinos of keV-mass
as dark matter candidates, their decay signals are actively searched for in
cosmic X-ray spectra. In this work, we consider the NSI that leads to atomic
ionization, which can be detected by direct dark matter experiments. It is
found that this inelastic scattering process for a nonrelativistic sterile
neutrino has a pronounced enhancement in the differential cross section at
energy transfer about half of its mass, manifesting experimentally as peaks in
the measurable energy spectra. The enhancement effects gradually smear out as
the sterile neutrino becomes relativistic. Using data taken with germanium
detectors that have fine energy resolution in keV and sub-keV regimes,
constraints on sterile neutrino mass and its transition magnetic moment are
derived and compared with those from astrophysical observations
TEL/AML1 Fusion Gene in Childhood Acute Lymphoblastic Leukemia in Southern Taiwan
Chromosomal abnormalities are found in 80–90% of childhood cases of acute lymphoblastic leukemia (ALL). Leukemia-specific chromosome aberrations not only have prognostic value, but also provide important clues for further investigation into leukogenesis, leukemic cell transformation, and proliferation. This study used reverse transcriptase–polymerase chain reaction techniques to detect transcripts of the leukemia-specific chromosome fusion gene, TEL/AML1, and to monitor the expression levels of the TEL-AML1 fusion transcript in ALL patients at sequential intervals during their treatment course. Twenty-five ALL patients were enrolled, including 20 who were newly diagnosed and five in relapse. The incidence of the TEL/AML1 fusion gene in this study was 32%. The clinical features of our eight TEL/AML1-positive ALL cases were similar to those in other studies. Blotting analysis of the levels of the TEL-AML1 fusion transcript was used to detect minimal residual disease. Reduced levels of TEL/AML1 expression were found in four of the six patients whose bone marrow or peripheral blood samples were obtained after treatment. Further investigation with a larger sample size is warranted
Osthole-Mediated Cell Differentiation through Bone Morphogenetic Protein-2/p38 and Extracellular Signal-Regulated Kinase 1/2 Pathway in Human Osteoblast Cells
Refractory gastric variceal bleeding secondary to splenic vein occlusion associated with abdominal lymphadenopathy
SummarySplenic vein occlusion caused by abdominal lymphadenopathy is rare. We herein present the case of a 80-year-old man with refractory isolated gastric variceal bleeding in the absence of pancreatic or liver disease. Left-sided portal hypertension was confirmed by angiography, and para-aortic lymphadenopathy compressing the splenic vein was identified by serial abdominal computed tomography. Endoscopic sclerosing therapy failed to treat the recurring gastric variceal hemorrhage. Therefore, splenectomy was suggested and the patient was successfully treated. The patient had been variceal bleeding free for 12 months since the surgery. In patients with isolated gastric varices but without advanced liver disease, a variety of diagnostic techniques should be attempted to elucidate the nature of portal hypertension, and left-sided portal hypertension should be suspected. For those cases in which endoscopic treatment failed to treat refractory gastric variceal bleeding, splenectomy can be an effective option
Elevated plasma level of visfatin/pre-b cell colony-enhancing factor in male oral squamous cell carcinoma patients
Objectives: Visfatin, also known as nicotiamide phosphoribosyltransferase or pre-B cell colony enhancing factor,
is a pro-inflammatory cytokine whose serum level is increased in various cancers. In this study, we investigated
whether plasma visfatin levels were altered in patients with oral squamous cell carcinoma (OSCC). The relation
ship between plasma visfatin levels and the pretreatment hematologic profile was also explored.
Study
Design: Plasma visfatin concentrations were measured through ELISA in OSCC patients and control sub-
D
esign: Plasma visfatin concentrations were measured through ELISA in OSCC patients and control sub-
esign: Plasma visfatin concentrations were measured through ELISA in OSCC patients and control sub
jects. A total of 51 patients with OSCC and 57 age- and body mass index (BMI)-matched control subjects were
studied. All study subjects were male.
Results: Plasma visfatin was found to be elevated in patients with OSCC (7.0 ± 4.5 vs. 4.8 ± 1.9 ng/ml, p = 0.002).
Multiple logistic regression analysis revealed visfatin as an independent association factor for OSCC, even after
full adjustment of known biomarkers. Visfatin level was significantly correlated with white blood cell (WBC)
count, neutrophil count, and hematocrit (all p < 0.05). In addition, WBC count, neutrophil count, and visfatin
gradually increased with stage progression, and hematocrit gradually decreased with stage progression (all p <
0.05).
Conclusion: Increased plasma visfatin levels were associated with OSCC, independent of risk factors, and were cor
related with inflammatory biomarkers. These data suggest that visfatin may act through inflammatory reactions to
play an important role in the pathogenesis of OSC
Intra-coronary administration of tacrolimus markedly attenuates infarct size and preserves heart function in porcine myocardial infarction
BACKGROUND: We test the hypothesis that intra-coronary tacrolimus administration can limit infarct size and preserve left ventricular ejection fraction (LVEF) after acute myocardial infarction (AMI) through ligating left anterior descending coronary artery (LAD) in mini-pigs. METHODS: Twelve male mini-pigs were randomized into AMI-saline (MI-only) group and AMI-tacrolimus (MI-Tac) group that received intra-coronary saline (3.0 mL) and tacrolimus (0.5 mg in 2.5 mL saline) injection, respectively, beyond site of ligation 30 minutes after LAD occlusion. RESULTS: Larger infarct area was noted in MI-only group (p < 0.001). Inflammatory biomarkers at protein [oxidative stress, tumor necrotic factor-α, nuclear factor-κB], gene (matrix metalloproteinase-9, plasminogen activator inhibitor-1), and cellular (CD40+, CD68+ inflammatory cells) levels were remarkably higher in MI-only animals (p < 0.01). Conversely, anti-inflammatory biomarkers at gene level (Interleukin-10), gene and protein level (endothelial nitric oxide synthase), and anti-oxidant biomarkers at both gene and protein levels [heme oxygenase 1, NAD(P)H:quinone oxidoreductase] were lower in MI-only group (p < 0.01). Number of apoptotic nuclei and apoptotic biomarkers expressions at gene and protein levels (Bax, caspase 3) were notably higher, whereas anti-apoptotic biomarkers at gene and protein levels (Bcl-2), LVEF, and fractional shortening were markedly lower in MI-only group (p < 0.001). CONCLUSION: Intra-coronary administration of tacrolimus significantly attenuated infarct size and preserved LV function
Minimum Shear Viscosity over Entropy Density at Phase Transition? --- A Counterexample
The ratio eta/s, shear viscosity (eta) to entropy density (s), reaches its
local minimum at the (second order) phase transition temperature in a wide
class of systems. It was suspected that this behavior might be universal.
However, a counterexample is found in a system of two weakly self-interacting
real scalar fields with one of them condensing at low temperatures while the
other remains in the symmetric phase. There is no interaction between the two
fields. The resulting eta/s is monotonically decreasing in temperature despite
the phase transition.Comment: 10 pages, 4 figure
- …