DIFFERENT AQUAPORIN-4 EXPRESSION IN GLIOBLASTOMA MULTIFORME PATIENTS WITH AND WITHOUT SEIZURES

Aquaporin-4 (AQP-4), the most important water channel in the brain, is expressed by astrocyte endfeet abutting microvessels. Altered expression levels of AQP-4 and redistribution of the protein throughout the membranes of cells found in glioblastoma multiforme (GBM) lead to development of the oedema often found surrounding the tumour mass. Dysregulation of AQP-4 also occurs in hippocampal sclerosis and cortical dysplasia in patients with refractory partial epilepsy. This work reports on analysis of the relationship between AQP-4 expression and the incidence of epileptic seizures in patients with GBM. Immunohistochemical and PCR techniques were used to evaluate AQP-4 in biopsy specimens from 19 patients with GBM, 10 of whom had a history of seizures prior to surgery. AQP-4 mRNA levels were identical in the two groups of patients, but AQP-4 expression was more frequently detected on the GBM membranes from specimens of patients with seizures than from those without (10 vs. 2,

Influencia de un cosechado nocturno de aceitunas en “Salento” sobre la calidad del aceite de oliva virgen extra

In southern Italy, some olive cultivars such as ‘Ogliarola Salentina’ ripen when the day temperature is still high, at up to 28 to 30 °C. This can affect both the oil quality and the expression of its valuable characteristics. In addition, it increases the risk of undesirable fermentation that can generate off-flavors. In the present study, nocturnal olive harvesting was carried out to determine the influence that temperature can have on the characteristics of the extra virgin olive oil, and particularly on the volatile and oxidative compounds. The data obtained are encouraging: the lower temperatures that occur during the night appear to have a particular and positive impact on the organoleptic characteristics of the extra virgin olive oil produced, with enhanced formation of the volatile compounds that contribute to the ‘green’ notes of the flavor. In areas where daytime temperatures are very high, the nocturnal harvesting of olives at the correct stage of maturity therefore represents a good agronomic practice for the production of oils with high organoleptic and nutritional merit.En el sur de Italia, algunas variedades de olivo maduran cuando la temperatura del día sigue siendo alta, hasta 28 °C a 30 °C. Esto puede perjudicar la calidad del aceite y a la expresión de sus valiosas características, y aumenta el riesgo de fermentación indeseable que puede generar malos sabores. En el presente estudio, la cosecha nocturna de aceitunas se llevó a cabo para determinar la influencia que la temperatura puede tener sobre las características del aceite de oliva virgen extra, y en particular sobre los compuestos volátiles y los compuestos relacionados con la oxidación. Los datos obtenidos son alentadores: las temperaturas más bajas que se producen durante la noche parecen tener un impacto positivo en las características organolépticas del aceite de oliva virgen extra producido, con una mejora de la formación de los compuestos volátiles que contribuyen a las notas “verdes” del sabor. En las zonas donde las temperaturas diurnas son muy altas, la cosecha nocturna de aceitunas, representa, por tanto, una buena práctica agronómica para la producción de aceites con grandes ventajas organoléptica y nutritivas

Proton-air cross section measurement with the ARGO-YBJ cosmic ray experiment

The proton-air cross section in the energy range 1-100 TeV has been measured by the ARGO-YBJ cosmic ray experiment. The analysis is based on the flux attenuation for different atmospheric depths (i.e. zenith angles) and exploits the detector capabilities of selecting the shower development stage by means of hit multiplicity, density and lateral profile measurements at ground. The effects of shower fluctuations, the contribution of heavier primaries and the uncertainties of the hadronic interaction models, have been taken into account. The results have been used to estimate the total proton-proton cross section at center of mass energies between 70 and 500 GeV, where no accelerator data are currently available.Comment: 14 pages, 9 figure

Let me see: Correlation between 5-ala fluorescence and molecular pathways in glioblastoma: A single center experience

Background: Despite the aggressiveness of multimodal treatment, glioblastoma (GBM) is still a challenge for neurosurgeons, neurooncologists, and radiotherapists. A surgical approach is still a cornerstone in GBM therapeutic management, as the extent of resection is strongly related both to overall survival and progression-free survival. From this perspective, the use of photodynamic molecules could represent an interesting tool to achieve maximal and safe resection. Being able to trace the lesion’s edges, indeed, could allow to improve the extent of resection and to minimize residual tumor while sparing normal tissue. The use of 5-aminolevulinic acid (5-ALA) as a photodynamic tracer is well established due to its strict correlation both with cellularity and metabolic activity of the GBM cell clones. Objective: Our study aims to define whether a different molecular asset of GBM (especially investigating IDH 1/2 mutation, proliferation index, and MGMT promoter methylation) results in different fluorescence expression, possibly because of differences in metabolic pathways due to different genotypes. Methods: Patients undergoing surgery for GBM removal at our Institute (Dep. Of Neurosurgery, Ospedale Città della Salute e della Scienza, University of Turin, Italy) were retrospectively reviewed. Patients with histological diagnosis confirmation and to whom 5-ALA was given before surgery were included. The whole surgical procedure was recorded and then analyzed by three different people (a medical student, a resident, and a senior surgeon with an interest in neurooncology and experience in using 5-ALA) and a score was assigned to the different degrees of intraoperative fluorescence. The degree of fluorescence was then matched with the genotype. Results: A trend of grade 2 fluorescence (i.e., ”strong”) was observed in the IDH 1/2 wild-type (WT) genotype, suggesting a more intense metabolic activity in this particular subgroup, while, no or weak fluorescence was observed more often in the IDH 1/2 mutated tumors, suggesting a lower metabolic activity. No relations were found between fluorescence grade and MGMT promoter methylation or, interestingly, cellularity. As a secondary analysis, more epileptogenicity of the IDH 1/2 mutated GBM was noticed, similarly to other recent literature. Conclusion: Our results do not support the use of 5-ALA as a diagnostic tool, or a way to substitute the molecular profiling, but confirm 5-ALA as a powerful metabolic tracer, able to easily detect the pathological cells, especially in the IDH WT genotype, and in this perspective, further studies will be necessary to better describe the metabolic activity of GBM cells

Gamma ray flares from Mrk421 in 2008 observed with the ARGO-YBJ detector

In 2008 the blazar Markarian 421 entered a very active phase and was one of the brightest sources in the sky at TeV energies, showing frequent flaring episodes. Using the data of ARGO-YBJ, a full coverage air shower detector located at Yangbajing (4300 m a.s.l., Tibet, China), we monitored the source at gamma ray energies E > 0.3 TeV during the whole year. The observed flux was variable, with the strongest flares in March and June, in correlation with X-ray enhanced activity. While during specific episodes the TeV flux could be several times larger than the Crab Nebula one, the average emission from day 41 to 180 was almost twice the Crab level, with an integral flux of (3.6 +-0.6) 10^-11 photons cm^-2 s^-1 for energies E > 1 TeV, and decreased afterwards. This paper concentrates on the flares occurred in the first half of June. This period has been deeply studied from optical to 100 MeV gamma rays, and partially up to TeV energies, since the moonlight hampered the Cherenkov telescope observations during the most intense part of the emission. Our data complete these observations, with the detection of a signal with a statistical significance of 3.8 standard deviations on June 11-13, corresponding to a gamma ray flux about 6 times larger than the Crab one above 1 TeV. The reconstructed differential spectrum, corrected for the intergalactic absorption, can be represented by a power law with an index alpha = -2.1 extending up to several TeV. The spectrum slope is fully consistent with previous observations reporting a correlation between the flux and the spectral index, suggesting that this property is maintained in different epochs and characterizes the source emission processes.Comment: Accepted for publication on ApJ

Observation of TeV gamma rays from the Cygnus region with the ARGO-YBJ experiment

We report the observation of TeV gamma-rays from the Cygnus region using the ARGO-YBJ data collected from 2007 November to 2011 August. Several TeV sources are located in this region including the two bright extended MGRO J2019+37 and MGRO J2031+41. According to the Milagro data set, at 20 TeV MGRO J2019+37 is the most significant source apart from the Crab Nebula. No signal from MGRO J2019+37 is detected by the ARGO-YBJ experiment, and the derived flux upper limits at 90% confidence level for all the events above 600 GeV with medium energy of 3 TeV are lower than the Milagro flux, implying that the source might be variable and hard to be identified as a pulsar wind nebula. The only statistically significant (6.4 standard deviations) gamma-ray signal is found from MGRO J2031+41, with a flux consistent with the measurement by Milagro.Comment: 14 pages, 4 figure

Mean Interplanetary Magnetic Field Measurement Using the ARGO-YBJ Experiment

The sun blocks cosmic ray particles from outside the solar system, forming a detectable shadow in the sky map of cosmic rays detected by the ARGO-YBJ experiment in Tibet. Because the cosmic ray particles are positive charged, the magnetic field between the sun and the earth deflects them from straight trajectories and results in a shift of the shadow from the true location of the sun. Here we show that the shift measures the intensity of the field which is transported by the solar wind from the sun to the earth.Comment: 6 papges,3 figure

Long-term monitoring of the TeV emission from Mrk 421 with the ARGO-YBJ experiment

ARGO-YBJ is an air shower detector array with a fully covered layer of resistive plate chambers. It is operated with a high duty cycle and a large field of view. It continuously monitors the northern sky at energies above 0.3 TeV. In this paper, we report a long-term monitoring of Mrk 421 over the period from 2007 November to 2010 February. This source was observed by the satellite-borne experiments Rossi X-ray Timing Explorer and Swift in the X-ray band. Mrk 421 was especially active in the first half of 2008. Many flares are observed in both X-ray and gamma-ray bands simultaneously. The gamma-ray flux observed by ARGO-YBJ has a clear correlation with the X-ray flux. No lag between the X-ray and gamma-ray photons longer than 1 day is found. The evolution of the spectral energy distribution is investigated by measuring spectral indices at four different flux levels. Hardening of the spectra is observed in both X-ray and gamma-ray bands. The gamma-ray flux increases quadratically with the simultaneously measured X-ray flux. All these observational results strongly favor the synchrotron self-Compton process as the underlying radiative mechanism.Comment: 30 pages, 8 figure