Circulating antimyenteric autoantibodies in Tunisian patients with idiopathic achalasia.

The physiopathology of idiopathic achalasia is still unknown. The description of circulating antimyenteric autoantibodies (CAA), directed against enteric neurons in sera of patients, suggests an autoimmune process. Recent data showed controversies according to the existence and the significance of CAA. The aims of this study were to investigate whether CAA are detected in Tunisian patients with idiopathic achalasia and to look for associated clinical or manometrical factors with CAA positivity. Twenty-seven patients with idiopathic achalasia and 57 healthy controls were prospectively studied. CAA were assessed by indirect immunofluorescence on intestinal monkey tissue sections. Western blot on primate cerebellum protein extract and dot technique with highly purified recombinant neuronal antigens (Hu, Ri, and Yo) were further used to analyze target antigens of CAA. CAA were significantly increased in achalasia patients compared with controls when considering nuclear or cytoplasmic fluorescence patterns. (33% vs. 12%, P = 0.03 and 48% vs. 23%, P = 0.001 respectively). By immunoblot analysis, CAA did not target neuronal antigens, however 52/53 and 49 kDa bands were consistently detected. CAA positivity was not correlated to specific clinical features. The results are along with previous studies demonstrating high CAA prevalence in achalasia patients. When reviewing technical protocols and interpretation criteria, several discrepancies which could explain controversies between studies were noted.

Solar photodegradation of Rhodamine B dye by Cu2O/TiO2 heterostructure: experimental and computational studies of degradation and toxicity.

CONTEXT AND RESULTS: In this study, the heterojunction Cu2O/TiO2 is used for the degradation of a cationic dye, Rhodamine B, under solar light irradiation over a wide pH range. The physical and optical properties of both semiconductors Cu2O and TiO2 are correlated with the photo-electrochemical characterization to establish the energy diagram of the heterojunction Cu2O/TiO2. X-ray diffraction, UV-visible, SEM, EDX, and BET analyses are conducted for both photocatalysts. The band gap (Eg) of 3.26 eV is obtained for TiO2 with an indirect optical transition. In the case of Cu2O, the transition is directly allowed at 2.05 eV. According to the BET analysis, the specific surface area of TiO2 particles is higher (82.65 m2 g-1) than that of Cu2O (29.81 m2 g-1). The flat band potentials, determined from the Mott-Schottky plots, are 0.3 and - 0.32 VSCE for TiO2 and Cu2O, respectively. The photocatalytic activity is directly proportional to the mass ratio, and the best result is obtained for the mass ratio 1:1 of Cu2O/TiO2. COMPUTATIONAL AND THEORETICAL TECHNIQUES: Furthermore, a theoretical study is conducted by using density functional theory to optimize the structure, reactivity sites of the RhB molecule, and physical parameters like the energy of the frontier molecular orbitals and electronegativity and to predict the proposed mechanism of RhB degradation as well as its intermediates. Also, molecular dynamics simulation is used to determine the adsorption behavior of RhB on TiO2 (101) and Cu2O (111) surfaces. The ecotoxicity evaluation showed that degradation products have significantly lower acute toxicity than RhB.

Spectrum of autoantibodies other than anti-desmoglein in pemphigus patients.

BACKGROUND: Pemphigus is a life-threatening autoimmune blistering disease mediated by autoantibodies against adhesion molecule of the skin. Its concurrence with systemic and organ-specific autoimmune disease was described in case reports. OBJECTIVES: To evaluate the presence of a broad spectrum of organ-specific and non-organ-specific autoantibodies other than anti-desmoglein antibodies in pemphigus patients. PATIENTS AND METHODS: Serum samples were obtained from 105 pemphigus foliaceus (PF) patients, 51 pemphigus vulgaris (PV) patients and 50 controls. Both indirect immunofluorescence assay and ELISA were used to assess the presence of autoantibodies related to connective tissue diseases, autoimmune hepatitis, vasculitis, rheumatoid arthritis, coeliac disease, diabetes and thyroiditis. RESULTS: Significant difference was observed between the three groups for anti-thyroglobulin antibodies in the pemphigus foliaceus group (18% vs. 4%, P=0.03). A significantly higher occurrence of IgM anti-cardiolipin (P=0.03), IgG anti-reticulin (P=0.01) and IgG anti-gliadin antibodies (P=0.008) were observed in the PV group. Cases with more than four autoantibodies were frequently positives for both anti-desmoglein 1 and anti-desmoglein 3. CONCLUSION: Autoantibodies other than anti-desmoglein antibodies are not rare in pemphigus patients. Clinical and serological follow-up of pemphigus patients with positive autoantibodies are needed to clarify their impact in disease evolution.