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Purpose: To investigate the clinical characteristics of nasopharyngeal carcinoma (NPC) and a concomitant hepatitis B virus (HBV) infection, as well as the potential effects of HBV infection and antiviral therapy on prognosis. Methods: We conducted a retrospective chart review of all NPC patients from December 2010 to December 2014. After collecting medical records and conducting follow‐ups on patients, a total of 876 eligible NPC patients were included. For each patient, medical records were reviewed. Factors predictive of outcome were compared using the log‐rank test and Cox regression analysis. Results: Among the 876 participants, 106 (12.1%) patients were HBV‐infected patients. The hepatitis B surface antigen‐positive [HBsAg(+)] group had a lower CD4+ T cell count than the HBsAg(−) group (P =.048). Among patients with stage I/II NPC, 5‐year overall survival (OS), disease‐free survival (DFS), relapse‐free survival, and distant metastasis‐free survival (DMFS) of the HBsAg(+) group were 82.5%, 70.7%, 87.7%, and 76.6%, respectively, whereas those of the HBsAg(−) group were 91.4%, 86.0%, 93.8%, and 92.1%, respectively. Statistically significant differences in OS, DFS, and DMFS existed between both groups (P =.017,.018, and.004, respectively). The multivariate analysis indicated that HBsAg status and N stage are independent risk factors affecting OS, DFS, and DMFS of NPC patients. A statistically significant difference in 5‐year DMFS existed between the antivirus (90.0%) and no‐antivirus groups (70.0%) (P =.043). Conclusions: Hepatitis B virus infection is an independent risk factor for early stage NPC, which may be associated with its reduced immune functions compared to the HBsAg(−) group. Anti‐HBV treatment may improve the prognosis of HBV‐infected NPC patients. [ABSTRACT FROM AUTHOR]

Describes the discovery of an apparent transition between active and non-active second-harmonic generation (SHG) in the NaNb[sub 3]O[sub 8] solid solutions with the tetragonal tungsten bronze structure. Observation of powder SHG with a magnitude comparable to KH[sub 2]PO[sub 4] upon addition of Nb[sub 2]O[sub 5]; Observation of microcracks and ferroelectric domain boundaries.

Leukodystrophies and genetic leukoencephalopathies are a rare group of disorders leading to progressive degeneration of cerebral white matter. They are associated with a spectrum of clinical phenotypes dominated by dementia, psychiatric changes, movement disorders and upper motor neuron signs. Mutations in at least 60 genes can lead to leukoencephalopathy with often overlapping clinical and radiological presentations. For these reasons, patients with genetic leukoencephalopathies often endure a long diagnostic odyssey before receiving a definitive diagnosis or may receive no diagnosis at all. In this study, we used focused and whole exome sequencing to evaluate a cohort of undiagnosed adult patients referred to a specialist leukoencephalopathy service. In total, 100 patients were evaluated using focused exome sequencing of 6100 genes. We detected pathogenic or likely pathogenic variants in 26 cases. The most frequently mutated genes were NOTCH3, EIF2B5, AARS2 and CSF1R. We then carried out whole exome sequencing on the remaining negative cases including four family trios, but could not identify any further potentially disease-causing mutations, confirming the equivalence of focused and whole exome sequencing in the diagnosis of genetic leukoencephalopathies. Here we provide an overview of the clinical and genetic features of these disorders in adults. [ABSTRACT FROM AUTHOR]

Despite the apparent clinical benefits of high-dose cytarabine (Ara-C) over lower dose Ara-C in acute myeloid leukemia (AML) therapy, the mechanism behind high-dose Ara-C therapy remains uncertain. In this study, a LC-MS-based method was carried out to investigate the metabolic alteration of ribonucleotide and deoxyribonucleotide in human promyelocytic leukemia cells (HL-60) after treatment with Ara-C to reveal its antitumor mechanism. The metabolic results revealed that four nucleotides (ATP, ADP, CDP, and dCTP) could be used as potential biomarkers indicating the benefit of high-dose Ara-C over lower dose Ara-C treatment. Combining metabolic perturbation and cell cycle analysis, we conjectured that, apart from the acknowledged mechanism of Ara-C on tumor inhibition, high-dose Ara-C could present a specific action pathway. It was suggested that the pronounced rise in AMP/ATP ratio induced by high-dose Ara-C can trigger AMP-activated protein kinase (AMPK) and subsequently Forkhead Box, class O (FoxO), to promote cell cycle arrest. Moreover, the significant decrease in CDP pool induced by high-dose Ara-C might further accelerate the reduction of dCTP, which then aggravates DNA synthesis disturbance. As a result, all of these alterations led to heightened tumor inhibition. This study provides new insight in the investigation of potential mechanisms in the clinical benefits of high-dose Ara-C in therapy for AML. [ABSTRACT FROM AUTHOR]

Flagella of some pathogens or marine microbes are sheathed by an apparent extension of the outer cell membrane. Although flagellar sheath has been reported for almost 60 years, little is known about its function and the mechanism of its assembly. Recently, we have observed a novel type of sheath that encloses a flagellar bundle, instead of a single flagellum, in a marine magnetotactic bacterium MO-1. Here, we reported isolation and characterization of the sheath which can be described as a six-start, right-handed helical tubular structure with a diameter of about 100 nm, and a pitch of helix of about 260 nm. By proteomic, microscopic and immunolabelling analyses, we showed that the sheath of MO-1 consists of glycoprotein with an apparent molecular mass > 350 kDa. This protein, named sheath-associated protein (Sap), shows homology with bacterial adhesins and eukaryotic calcium-dependent adherent proteins (cadherin). Most importantly, we showed that calcium ions mediate the assembly of the tubular-shaped sheath and disintegration of the sheath was deleterious for smooth swimming of MO-1 cells. The disintegrated sheath was efficiently reconstituted in vitro by adding calcium ions. Altogether, these results demonstrate a novel bacterial Ca-dependent surface architecture, which is essential for bacterial swimming. [ABSTRACT FROM AUTHOR]