314 research outputs found

    MASEP gamma knife radiosurgery for secretory pituitary adenomas: experience in 347 consecutive cases

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    <p>Abstract</p> <p>Background</p> <p>Secretory pituitary adenomas are very common brain tumors. Historically, the treatment armamentarium for secretory pituitary adenomas included neurosurgery, medical management, and fractionated radiotherapy. In recent years, MASEP gamma knife radiosurgery (MASEP GKRS) has emerged as an important treatment modality in the management of secretory pituitary adenomas. The goal of this research is to define accurately the efficacy, safety, complications, and role of MASEP GKRS for treatment of secretory pituitary adenomas.</p> <p>Methods</p> <p>Between 1997 and 2007 a total of 347 patients with secretory pituitary adenomas treated with MASEP GKRS and with at least 60 months of follow-up data were identified. In 47 of these patients some form of prior treatment such as transsphenoidal resection, or craniotomy and resection had been conducted. The others were deemed ineligible for microsurgery because of body health or private choice, and MASEP GKRS served as the primary treatment modality. Endocrinological, ophthalmological, and neuroradiological responses were evaluated.</p> <p>Results</p> <p>MASEP GKRS was tolerated well in these patients under the follow-up period ranged from 60 to 90 months; acute radioreaction was rare and 17 patients had transient headaches with no clinical significance. Late radioreaction was noted in 1 patient and consisted of consistent headache. Of the 68 patients with adrenocorticotropic hormone-secreting(ACTH) adenomas, 89.7% showed tumor volume decrease or remain unchanged and 27.9% experienced normalization of hormone level. Of the 176 patients with prolactinomas, 23.3% had normalization of hormone level and 90.3% showed tumor volume decrease or remain unchanged. Of the 103 patients with growth hormone-secreting(GH) adenomas, 95.1% experienced tumor volume decrease or remain unchanged and 36.9% showed normalization of hormone level.</p> <p>Conclusion</p> <p>MASEP GKRS is safe and effective in treating secretory pituitary adenomas. None of the patients in our study experienced injury to the optic apparatus or had other neuropathies related with gamma knife. MASEP GKRS may serve as a primary treatment method in some or as a salvage treatment in the others. However, treatment must be tailored to meet the patient's symptoms, tumor location, tumor morphometry, and overall health. Longer follow-up is required for a more complete assessment of late radioreaction and treatment efficacy.</p

    Observation of a ppb mass threshoud enhancement in \psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) decay

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    The decay channel ψπ+πJ/ψ(J/ψγppˉ)\psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) is studied using a sample of 1.06×1081.06\times 10^8 ψ\psi^\prime events collected by the BESIII experiment at BEPCII. A strong enhancement at threshold is observed in the ppˉp\bar{p} invariant mass spectrum. The enhancement can be fit with an SS-wave Breit-Wigner resonance function with a resulting peak mass of M=186113+6(stat)26+7(syst)MeV/c2M=1861^{+6}_{-13} {\rm (stat)}^{+7}_{-26} {\rm (syst)} {\rm MeV/}c^2 and a narrow width that is Γ<38MeV/c2\Gamma<38 {\rm MeV/}c^2 at the 90% confidence level. These results are consistent with published BESII results. These mass and width values do not match with those of any known meson resonance.Comment: 5 pages, 3 figures, submitted to Chinese Physics

    LATS2 is De-methylated and Overexpressed in Nasopharyngeal Carcinoma and Predicts Poor Prognosis

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    <p>Abstract</p> <p>Background</p> <p>LATS2, which encodes a novel serine/threonine kinase, is known to be important in centrosome duplication and in the maintenance of genomic stability. Recently, a potential role for LATS2 in cancer has been reported. In breast cancer and acute lymphoblastic leukemia (ALL), LATS2 mRNA is downregulated and has been suggested to be a tumor suppressor. However, the role of LATS2 in nasopharyngeal carcinoma has not been investigated. In this study, we aimed to investigate the expression pattern of LATS2 and its clinicopathological involvement in nasopharyngeal carcinoma to understand its effect on cell survival.</p> <p>Methods</p> <p>Using quantitative real time PCR and immunoblotting, the expression of LATS2 was detected in nasopharyngeal carcinoma cell lines and in the immortalized nasopharyngeal epithelial cell line NP69. Using immunohistochemistry, we analyzed LATS2 protein expression in 220 nasopharyngeal carcinoma cases. The association of LATS2 protein expression with the clinicopathological characteristics and the prognosis of nasopharyngeal carcinoma were subsequently assessed. Using methylation specific PCR, we detected the methylation status of the LATS2 promoter. RNA interference was performed by transfecting siRNA to specifically knock down LATS2 expression in 5-8F and CNE2.</p> <p>Results</p> <p>LATS2 protein was detected in 178 of 220 (80.91%) cases of nasopharyngeal carcinoma. LATS2 overexpression was a significant, independent prognosis predictor (<it>P </it>= 0.037) in nasopharyngeal carcinoma patients. Methylation specific PCR revealed that 36.7% (11/30) of nasopharyngeal carcinoma tissues and all of the chronic nasopharyngeal inflammation samples were methylated. Functional studies showed that the suppression of LATS2 expression in nasopharyngeal carcinoma (5-8F and CNE2) cell lines by using specific small interfering (siRNA) resulted in the inhibition of growth, induction of apoptosis and S-phase cell cycle increase. Overexpression of LATS2 in NP69 stimulated cell proliferation.</p> <p>Conclusions</p> <p>Our results indicate that LATS2 might play a role in the tumorigenesis of nasopharyngeal carcinoma by promoting the growth of nasopharyngeal carcinoma cells. Transfection with specific siRNA might be feasible for the inhibition of growth, induction of apoptosis and S phase increase in nasopharyngeal carcinoma.</p

    A chemical survey of exoplanets with ARIEL

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    Thousands of exoplanets have now been discovered with a huge range of masses, sizes and orbits: from rocky Earth-like planets to large gas giants grazing the surface of their host star. However, the essential nature of these exoplanets remains largely mysterious: there is no known, discernible pattern linking the presence, size, or orbital parameters of a planet to the nature of its parent star. We have little idea whether the chemistry of a planet is linked to its formation environment, or whether the type of host star drives the physics and chemistry of the planet’s birth, and evolution. ARIEL was conceived to observe a large number (~1000) of transiting planets for statistical understanding, including gas giants, Neptunes, super-Earths and Earth-size planets around a range of host star types using transit spectroscopy in the 1.25–7.8 μm spectral range and multiple narrow-band photometry in the optical. ARIEL will focus on warm and hot planets to take advantage of their well-mixed atmospheres which should show minimal condensation and sequestration of high-Z materials compared to their colder Solar System siblings. Said warm and hot atmospheres are expected to be more representative of the planetary bulk composition. Observations of these warm/hot exoplanets, and in particular of their elemental composition (especially C, O, N, S, Si), will allow the understanding of the early stages of planetary and atmospheric formation during the nebular phase and the following few million years. ARIEL will thus provide a representative picture of the chemical nature of the exoplanets and relate this directly to the type and chemical environment of the host star. ARIEL is designed as a dedicated survey mission for combined-light spectroscopy, capable of observing a large and well-defined planet sample within its 4-year mission lifetime. Transit, eclipse and phase-curve spectroscopy methods, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allow us to measure atmospheric signals from the planet at levels of 10–100 part per million (ppm) relative to the star and, given the bright nature of targets, also allows more sophisticated techniques, such as eclipse mapping, to give a deeper insight into the nature of the atmosphere. These types of observations require a stable payload and satellite platform with broad, instantaneous wavelength coverage to detect many molecular species, probe the thermal structure, identify clouds and monitor the stellar activity. The wavelength range proposed covers all the expected major atmospheric gases from e.g. H2O, CO2, CH4 NH3, HCN, H2S through to the more exotic metallic compounds, such as TiO, VO, and condensed species. Simulations of ARIEL performance in conducting exoplanet surveys have been performed – using conservative estimates of mission performance and a full model of all significant noise sources in the measurement – using a list of potential ARIEL targets that incorporates the latest available exoplanet statistics. The conclusion at the end of the Phase A study, is that ARIEL – in line with the stated mission objectives – will be able to observe about 1000 exoplanets depending on the details of the adopted survey strategy, thus confirming the feasibility of the main science objectives.Peer reviewedFinal Published versio

    Human U87 Astrocytoma Cell Invasion Induced by Interaction of βig-h3 with Integrin α5β1 Involves Calpain-2

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    It is known that βig-h3 is involved in the invasive process of many types of tumors, but its mechanism in glioma cells has not been fully clarified. Using immunofluorescent double-staining and confocal imaging analysis, and co-immunoprecipitation assays, we found that βig-h3 co-localized with integrin α5β1 in U87 cells. We sought to elucidate the function of this interaction by performing cell invasion assays and gelatin zymography experiments. We found that siRNA knockdowns of βig-h3 and calpain-2 impaired cell invasion and MMP secretion. Moreover, βig-h3, integrins and calpain-2 are known to be regulated by Ca2+, and they are also involved in tumor cell invasion. Therefore, we further investigated if calpain-2 was relevant to βig-h3-integrin α5β1 interaction to affect U87 cell invasion. Our data showed that βig-h3 co-localized with integrin α5β1 to enhance the invasion of U87 cells, and that calpain-2, is involved in this process, acting as a downstream molecule

    Delayed Postconditioning Protects against Focal Ischemic Brain Injury in Rats

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    We and others have reported that rapid ischemic postconditioning, interrupting early reperfusion after stroke, reduces infarction in rats. However, its extremely short therapeutic time windows, from a few seconds to minutes after reperfusion, may hinder its clinical translation. Thus, in this study we explored if delayed postconditioning, which is conducted a few hours after reperfusion, offers protection against stroke.Focal ischemia was generated by 30 min occlusion of bilateral common carotid artery (CCA) combined with permanent occlusion of middle cerebral artery (MCA); delayed postconditioning was performed by repetitive, brief occlusion and release of the bilateral CCAs, or of the ipsilateral CCA alone. As a result, delayed postconditioning performed at 3h and 6h after stroke robustly reduced infarct size, with the strongest protection achieved by delayed postconditioning with 6 cycles of 15 min occlusion/15 min release of the ipsilateral CCA executed from 6h. We found that this delayed postconditioning provided long-term protection for up to two months by reducing infarction and improving outcomes of the behavioral tests; it also attenuated reduction in 2-[(18)F]-fluoro-2-deoxy-D-glucose (FDG)-uptake therefore improving metabolism, and reduced edema and blood brain barrier leakage. Reperfusion in ischemic stroke patients is usually achieved by tissue plasminogen activator (tPA) application, however, t-PA's side effect may worsen ischemic injury. Thus, we tested whether delayed postconditioning counteracts the exacerbating effect of t-PA. The results showed that delayed postconditioning mitigated the worsening effect of t-PA on infarction.Delayed postconditioning reduced ischemic injury after focal ischemia, which opens a new research avenue for stroke therapy and its underlying protective mechanisms

    Mitochondrial Localized STAT3 Is Involved in NGF Induced Neurite Outgrowth

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    Background: Signal transducer and activator of transcription 3 (STAT3) plays critical roles in neural development and is increasingly recognized as a major mediator of injury response in the nervous system. Cytokines and growth factors are known to phosphorylate STAT3 at tyrosine 705 with or without the concomitant phosphorylation at serine 727, resulting in the nuclear localization of STAT3 and subsequent transcriptional activation of genes. Recent evidence suggests that STAT3 may control cell function via alternative mechanisms independent of its transcriptional activity. Currently, the involvement of STAT3 mono-phosphorylated at residue serine 727 (P-Ser-STAT3) in neurite outgrowth and the underlying mechanism is largely unknown. Principal Findings: In this study, we investigated the role of nerve growth factor (NGF) induced P-Ser-STAT3 in mediating neurite outgrowth. NGF induced the phosphorylation of residue serine 727 but not tyrosine 705 of STAT3 in PC12 and primary cortical neuronal cells. In PC12 cells, serine but not tyrosine dominant negative mutant of STAT3 was found to impair NGF induced neurite outgrowth. Unexpectedly, NGF induced P-Ser-STAT3 was localized to the mitochondria but not in the nucleus. Mitochondrial STAT3 was further found to be intimately involved in NGF induced neurite outgrowth and the production of reactive oxygen species (ROS). Conclusion: Taken together, the findings herein demonstrated a hitherto unrecognized novel transcription independen

    Assessing the clinical utility of cancer genomic and proteomic data across tumor types

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    Molecular profiling of tumors promises to advance the clinical management of cancer, but the benefits of integrating molecular data with traditional clinical variables have not been systematically studied. Here we retrospectively predict patient survival using diverse molecular data (somatic copy-number alteration, DNA methylation and mRNA, miRNA and protein expression) from 953 samples of four cancer types from The Cancer Genome Atlas project. We found that incorporating molecular data with clinical variables yielded statistically significantly improved predictions (FDR < 0.05) for three cancers but those quantitative gains were limited (2.2–23.9%). Additional analyses revealed little predictive power across tumor types except for one case. In clinically relevant genes, we identified 10,281 somatic alterations across 12 cancer types in 2,928 of 3,277 patients (89.4%), many of which would not be revealed in single-tumor analyses. Our study provides a starting point and resources, including an open-access model evaluation platform, for building reliable prognostic and therapeutic strategies that incorporate molecular data
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