Beam Spin Asymmetry in Semi-Inclusive Electroproduction of Hadron Pairs.

A first measurement of the longitudinal beam spin asymmetry A_{LU} in the semi-inclusive electroproduction of pairs of charged pions is reported. A_{LU} is a higher-twist observable and offers the cleanest access to the nucleon twist-3 parton distribution function e(x). Data have been collected in the Hall-B at Jefferson Lab by impinging a 5.498-GeV electron beam on a liquid-hydrogen target, and reconstructing the scattered electron and the pion pair with the CLAS detector. One-dimensional projections of the A_{LU}^{sinϕ_{R}} moments are extracted for the kinematic variables of interest in the valence quark region. The understanding of dihadron production is essential for the interpretation of observables in single-hadron production in semi-inclusive DIS, and pioneering measurements of single-spin asymmetries in dihadron production open a new avenue in studies of QCD dynamics.

Exploring the Structure of the Bound Proton with Deeply Virtual Compton Scattering.

In the past two decades, deeply virtual Compton scattering of electrons has been successfully used to advance our knowledge of the partonic structure of the free proton and investigate correlations between the transverse position and the longitudinal momentum of quarks inside the nucleon. Meanwhile, the structure of bound nucleons in nuclei has been studied in inclusive deep-inelastic lepton scattering experiments off nuclear targets, showing a significant difference in longitudinal momentum distribution of quarks inside the bound nucleon, known as the EMC effect. In this Letter, we report the first beam spin asymmetry (BSA) measurement of exclusive deeply virtual Compton scattering off a proton bound in ^{4}He. The data used here were accumulated using a 6 GeV longitudinally polarized electron beam incident on a pressurized ^{4}He gaseous target placed within the CLAS spectrometer in Hall-B at the Thomas Jefferson National Accelerator Facility. The azimuthal angle (ϕ) dependence of the BSA was studied in a wide range of virtual photon and scattered proton kinematics. The Q^{2}, x_{B}, and t dependencies of the BSA on the bound proton are compared with those on the free proton. In the whole kinematical region of our measurements, the BSA on the bound proton is smaller by 20% to 40%, indicating possible medium modification of its partonic structure.

Direct Observation of Proton-Neutron Short-Range Correlation Dominance in Heavy Nuclei.

We measured the triple coincidence A(e,e^{'}np) and A(e,e^{'}pp) reactions on carbon, aluminum, iron, and lead targets at Q^{2}>1.5 (GeV/c)^{2}, x_{B}>1.1 and missing momentum >400 MeV/c. This was the first direct measurement of both proton-proton (pp) and neutron-proton (np) short-range correlated (SRC) pair knockout from heavy asymmetric nuclei. For all measured nuclei, the average proton-proton (pp) to neutron-proton (np) reduced cross-section ratio is about 6%, in agreement with previous indirect measurements. Correcting for single-charge exchange effects decreased the SRC pairs ratio to ∼3%, which is lower than previous results. Comparisons to theoretical generalized contact formalism (GCF) cross-section calculations show good agreement using both phenomenological and chiral nucleon-nucleon potentials, favoring a lower pp to np pair ratio. The ability of the GCF calculation to describe the experimental data using either phenomenological or chiral potentials suggests possible reduction of scale and scheme dependence in cross-section ratios. Our results also support the high-resolution description of high-momentum states being predominantly due to nucleons in SRC pairs.

Frictional purpuric eruption associated with angiotensin II receptor blockers.

Angiotensin II receptor blockers (ARBs) are drugs generally well tolerated. There are few reports about cutaneous side effects of ARBs. The present authors describe herein four cases of purpuric eruption mainly involving sites of friction in patients taking ARBs. These eruptions completely cleared after stopping the drug and implementing preservative measures to reduce friction.

Cutaneous manifestations of Mycobacterium gordonae infection described for the first time in Italy: a case report.

INTRODUCTION: Mycobacterium gordonae is one of the least pathogenic of the mycobacteria. This pathogen may produce caseating or non-caseating granulomas, and skin lesions showing acute or chronic inflammation with scattered histiocytes and giant cells have been seen. The mortality rate is less than 0.1%. Mycobacterium gordonae may be a marker of severe immunosuppression in patients infected with human immunodeficiency virus. CASE PRESENTATION: We report a case of Mycobacterium gordonae infection in an 86-year-old woman and discuss the problems inherent to the identification and treatment of this emerging pathogen. Mycobacterium gordonae strain we isolated was resistant to trimethoprim-sulfamethoxazole but sensitive to ciprofloxacin, and long term administration (six months) induced complete healing of the cutaneous abscesses. CONCLUSION: Advanced laboratory diagnostic techniques have improved the isolation and identification of nontuberculous mycobacteria. The diagnosis requires a high index of clinical suspicion, as detection by conventional methods is difficult. To our knowledge, this patient is the first documented case of cutaneous infection from this pathogen in Italy.

Preliminary data on Pemphigus vulgaris treatment by a proteomics-defined peptide: a case report.

BACKGROUND: Although described by Hippocrates in 400 B.C., pemphigus disease still needs a safe therapeutical approach, given that the currently used therapies (i.e. corticosteroids and immunosuppressive drugs) often provoke collateral effects. Here we present preliminary data on the possible use of a proteomics derived desmoglein peptide which appears promising in halting disease progression without adverse effects. METHODS: The low-similarity Dsg349-60REWVKFAKPCRE peptide was topically applied for 1 wk onto a lesion in a patient with a late-stage Pemphigus vulgaris (PV) complicated by diabetes and cataract disease. The peptide was applied as an adjuvant in combination with the standard corticosteroid-based immunosuppressive treatment. RESULTS: After 1 wk, the treated PV eroded lesion appeared dimensionally reduced and with an increased rate of re-epithelization when compared to adjacent non-treated lesions. Short-term benefits were: decrease of anti-Dsg antibody titer and reduction of the corticosteroid dosage. Long-term benefits: after two years following the unique 1-wk topical treatment, the decrease of anti-Dsg antibody titer persists. The patient is still at the low cortisone dosage. Adverse effects: no adverse effect could be monitored. CONCLUSION: With the limits inherent to any preliminary study, this case report indicates that topical treatment with Dsg349-60REWVKFAKPCRE peptide may represent a feasible first step in the search for a simple, effective and safe treatment of PV.

Recalcitrant scalp folliculitis: a possible role of herpes simplex virus type 2.

We report the case of a 70-year-old man with a 1 year history of relapsing folliculitis of the scalp. Bacteriological, mycological and the Tzanck tests from the lesions were negative. Histopathological study showed suppurative perifollicular flogosis. Virological cultures were negative, while HSV nested polymerase chain reaction (nPCR) assays made on swabs and histological sections from the scalp lesions demonstrated the presence of herpes simplex virus type-2 (HSV-2) in all samples. Skin swabs of healthy areas yielded negative results for HSV-2 infection. The folliculitis showed a marked and quick improvement after therapy with famciclovir suggesting a possible etiologic role of HSV-2 in the scalp folliculitis.

Long-term toxic effects of radiations: sarcomatoid carcinoma and multiple basal cell carcinoma of the limbs in chronic radiodermatitis.

A 73-year-old woman was referred to our attention for the presence of severe chronic lymphoedema and neoplastic lesions of the limbs. When she was 19 years old, the patient had undergone X-ray epilation of the limbs to remove unwanted body hair. The neoplastic lesions, observed 2 years before our observation, were excised, and histological examination revealed multiple basal cell carcinomas and a spindle squamous cell carcinoma on the left thigh. The case we observed offers some interesting points of consideration as it shows that in nonexposed areas cutaneous carcinomas can appear many years after irradiation and that the same treatment consequently requires careful follow-up for life. Another point of interest is the particular hystological aspect of neoplastic lesions in the site of radiodermatitis that requires in-depth immunohistochemical investigation for an exact diagnosis. Patients with previous treatment with ionizing radiation also in nonexposed areas need lifelong follow-up to identify cutaneous tumors at an early treatable stage.

Characterization of polyclonal antibodies raised against a linear peptide determinant of desmoglein-3.

Our labs are pursueing the goal of exactly defining the qualities of peptide antigenicity, immunogenicity and pathogenicity in order to develop safe specific immunotherapies by utilizing specific portions of disease-associated-proteins (DAPs). Using as a model the Pemphigus vulgaris antigen (PVA) desmoglein 3 (Dsg3), we have studied the murine humoral response against the Dsg3 amino acid 49-60 peptide sequence, previously characterized as sequence having low similarity to the mouse proteome. The results show that the low-similarity Dsg3(49-60)REWVKFAKPCRE peptide does not elicit pathogenic antibodies.

Relapsing herpes simplex-2 folliculitis in the beard area.

We describe the case of a 52-year-old immunocompetent man with recurrent folliculitis on the left cheek, associated with intense pain. Bacteriological, mycological and Tzanck tests from the lesions were negative. Histopathological study showed an aspecific flogosis pattern. Virological tests carried out on swabs and paraffin-embedded tissue sections from the facial lesions by nested PCR technique (nPCR) demonstrated the presence of herpes simplex virus type 2 (HSV\2) in both samples. Skin swabs from other healthy areas of the face resulted negative for herpetic infection. A diagnosis of recurrent herpetic folliculitis by HSV\2 was made. This case report underlines that even in immunocompetent patients HSV\2 lesions can feature atypical clinical aspects. In dermatological assessment the benefits of routine PCR techniques for differential diagnosis of herpetic infection should be considered above all for the prompt initiation of antiviral therapy and appropriate patient management.

Gelatinase expression at positive patch test reactions.

Matrix metalloproteases (MMPs) are proteolytic enzymes involved in tissue remodelling and extracellular matrix (ECM) turnover. They are secreted in a latent form and activated at the cellular surface by a membrane type-1 MMP (MT1-MMP) and a tissue inhibitor of MMP-2 (TIMP-2) that is also responsible for striking a balance between the proteolytic enzymes and TIMP-2. In allergic contact dermatitis (ACD) patients, MMP-2 and MMP-9, two members of the MMPs family, were increased during the challenge phase, in involved but not uninvolved skin. In contrast, TIMP-2 was more evident in uninvolved than involved skin, while no differences were observed with regard to MT1-MMP staining. Comparing the serum of ACD patients with that of healthy subjects, these differences were not observed. These data suggest that MMP-2 and MMP-9 could play a role in the mechanisms inducing alterations of the epidermal architecture, and in the pathogenesis of the lesions.