Impairment of recent thymic emigrants in HCV infection.

Hepatitis C Virus (HCV) often has a more favorable course in younger patients. Considering the involution of the thymic function with age, we investigated the output of recent thymic emigrants (RTE) in HCV patients. To evaluate RTE, we used a competitive quantitative PCR in order to determine the percentages of cells with cj-T cell receptor excision circles (TREC). This study was performed in 14 HCV patients at diagnosis and before any anti-HCV treatment. The results obtained in this group were compared to those obtained in a group of age-matched controls. We found that in the 14 HCV patients naive for anti-HCV treatment the mean percentage of cj-TREC was 3%. We could not detect a correlation between the percentages of cj-TREC and age or patients' viremia. In contrast, in the 26 age-matched controls mean percentage of cj-TREC was 5.6% (P=0.01). Our study describes a novel immune defect in HCV patients. Additional studies are needed to get further insight in the possible role of TREC defect in the pathogenesis and prognosis of the disease

Impairment of recent thymic emigrants in HCV infection

Hepatitis C Virus (HCV) often has a more favorable course in younger patients. Considering the involution of the thymic function with age, we investigated the output of recent thymic emigrants (RTE) in HCV patients. To evaluate RTE, we used a competitive quantitative PCR in order to determine the percentages of cells with cj-T cell receptor excision circles (TREC). This study was performed in 14 HCV patients at diagnosis and before any anti-HCV treatment. The results obtained in this group were compared to those obtained in a group of age-matched controls. We found that in the 14 HCV patients naive for anti-HCV treatment the mean percentage of cj-TREC was 3%. We could not detect a correlation between the percentages of cj-TREC and age or patients' viremia. In contrast, in the 26 age-matched controls mean percentage of cj-TREC was 5.6% (P=0.01). Our study describes a novel immune defect in HCV patients. Additional studies are needed to get further insight in the possible role of TREC defect in the pathogenesis and prognosis of the disease

Using the photons from the Crab Nebula seen by GLAST to calibrate MAGIC and the imaging air Cherenkov telescopes

n this article we discuss the possibility of using the observations by GLAST of standard gamma sources, as the Crab Nebula, to calibrate imaging air Cherenkov detectors, MAGIC in particular, and optimise their energy resolution. We show that at around 100 GeV the absolute energy calibration uncertainty of Cherenkov telescopes can be reduced to less than or similar to 10% by means of such cross-calibration procedure

Using the photons from the Crab Nebula seen by GLAST to calibrate MAGIC and the Imaging Air Cherenkov Telescopes

In this article we discuss the possibility of using the observations by GLAST of standard gamma sources, as the Crab Nebula, to calibrate Imaging Air Cherenkov detectors, MAGIC in particular, and optimise their energy resolution. We show that at around 100 GeV the absolute energy calibration uncertainty of Cherenkov telescopes can be reduced to <10% by means of such cross-calibration procedure

Comparative study of <111> and <100> crystals and capacitance measurements on Si strip detectors in CMS

For the construction of the silicon microstrip detectors for the tracker of the CMS experiment, two different substrate choices were investigated: A high-resistivity (6 k Omega cm) substrate with crystal orientation and a low-resistivity (2 k Omega cm) one with crystal orientation. The interstrip and backplane capacitances were measured before and after the exposure to radiation in a range of strip pitches from 60 mu m to 240 mu m and for values of the width-over-pitch ratio between 0.1 and 0.5. (3 refs)

Search for Pentaquarks in the Hadronic Decays of the Z Boson with the DELPHI Detector at LEP.

The quark model does not exclude states composed of more than three quarks, like pentaquark systems. Controversial evidence for such states has been published in the last years, in particular: for a strange pentaquark Θ(1540)+; for a double-strange state, the Ξ(1862)−−, subsequently called Φ(1860)−−; and for a charmed state, the Θc(3100)0. If confirmed, a full pentaquark family might exist; such pentaquark states could be produced in e+e− annihilations near the Z energy. In this Letter a search for pentaquarks is described using the DELPHI detector at LEP, characterized by powerful particle identification sub-systems crucial in the separation of the signal from the background for these states. At 95% CL, upper limits are set on the production rates N of such particles and their charge-conjugate state per Z decay: , NΘ++<1.6×10−3, NΦ(1860)−−×Br(Φ(1860)−−→Ξ−π−)<2.9×10−4,