Thyroid signaling in immune organs and cells of the teleost fish rainbow trout (Oncorhynchus mykiss).

Thyroid hormones are involved in modulating the immune system in mammals. In contrast, there is no information on the role played by these hormones in the immune system of teleost fish. Here we provide initial evidence for the presence of active thyroid signaling in immune organs and cells of teleosts. We demonstrate that immune organs (head kidney and spleen) and isolated leukocytes (from head kidney and peripheral blood) of the rainbow trout (Oncorhynchus mykiss) express both thyroid receptor α (THRA) and ß (THRB). Absolute mRNA levels of THRA were significantly higher than those of THRB. THRA showed higher expression in immune organs and isolated immune cells compared to the reference organ, liver, while THRB showed the opposite. In vivo exposure of trout to triiodothryronine (T3) or the anti-thyroid agent propylthiouracil (PTU) altered THR expression in immune organs and cells. Effect of T3 and PTU over the relative expression of selected marker genes of immune cell subpopulations was also studied. Treatments changed the relative expression of markers of cytotoxic, helper and total T cells (cd4, cd8a, trb), B lymphocytes (mIgM) and macrophages (csf1r). These findings suggest that the immune system of rainbow trout is responsive to thyroid hormones.

Absence of exponential sensitivity to small perturbations in nonintegrable systems of spins 1/2.

We show that macroscopic nonintegrable lattices of spins 1/2, which are often considered to be chaotic, do not exhibit the basic property of classical chaotic systems, namely, exponential sensitivity to small perturbations. We compare chaotic lattices of classical spins and nonintegrable lattices of spins 1/2 in terms of their magnetization responses to an imperfect reversal of spin dynamics known as Loschmidt echo. In the classical case, magnetization is exponentially sensitive to small perturbations with a characteristic exponent equal to twice the value of the largest Lyapunov exponent of the system. In the case of spins 1/2, magnetization is only power-law sensitive to small perturbations.

Vaccination of mice with chitosan nanogel-associated recombinant NcPDI against challenge infection with Neospora caninum tachyzoites.

The effects of nanogel encapsulation of recombinant NcPDI (recNcPDI) following vaccination of mice by intranasal or intraperitoneal routes and challenge infection with Neospora caninum tachyzoites were investigated. Nanogels were chitosan based, with an alginate or alginate-mannose surface. None of the mice receiving recNcPDI intraperitoneal (i.p.) (without nanogels) survived, whereas intranasal (i.n.) application protected 9 of 10 mice from disease. Association of recNcPDI with nanogels improved survival of i.p. vaccinated mice, but nanogels without recNcPDI gave similar protection levels. When nanogels were inoculated via the i.n. route, 80% of the mice were protected. Association of recNcPDI with the alginate-coated nanogels protected all mice against disease. Quantification of the cerebral parasite burden showed a significant reduction of parasite numbers in most experimental groups vaccinated i.n., except those vaccinated with alginate-mannose nanogels with or without recNcPDI. For i.p. vaccinated groups, no significant differences in cerebral infection densities were measured, but there was a reduction in the groups vaccinated with recNcPDI associated with both types of nanogels. Analysis of the immune responses of infected mice indicated that association of recNcPDI with nanogels altered the patterns of cytokine mRNA expression profiles, but had no major impact on the antibody subtype responses. Nevertheless, this did not necessarily relate to the protection.

Use of integrated FDG PET/CT imaging in pulmonary carcinoid tumours.

BACKGROUND: Integrated positron emission tomography (PET)/computed tomography (CT) scanners have been recently introduced in the diagnostic work-up of suspected pulmonary malignancy and demonstrate encouraging results in the staging of nonsmall-cell lung cancer. OBJECTIVE: To evaluate the usefulness of integrated FDG PET/CT in pulmonary carcinoid tumours. SETTING: University hospital. METHODS: We studied 13 patients (mean age +/- 1 SD, 57 +/- 11 years) with pulmonary carcinoid tumours. All patients demonstrated a single pulmonary lesion. Integrated PET/CT scan and surgical resection were performed in all patients. RESULTS: The pulmonary lesion size ranged from 1.1 to 5.0 cm. Final histological diagnosis confirmed 12 typical and one atypical pulmonary carcinoid. Mean proliferation rate of the typical carcinoids was 1.7 +/- 1.4%. None of the patients had recurrent carcinoid disease or died during follow-up (864 +/- 218 days). Mean standardized uptake value (SUV) of (18)F-fluorodeoxyglucose (FDG) in typical carcinoids was 3.0 +/- 1.5 (range 1.2 - 6.6); SUV in the atypical carcinoid was remarkably high with a value of 8.5. The SUV was lower than 2.5 in 6 of 12 patients (50%). Mediastinal lymph node metastases or extrathoracic metastases were not detected in any patient. CONCLUSIONS: (18)F-fluorodeoxyglucose PET/CT imaging improves accurate localization of metabolic activity and thus the interpretation of pulmonary lesions on CT. FDG uptake in pulmonary carcinoid tumours is often lower than expected for malignant tumours. Therefore, surgical resection or biopsy of lesions suspected to be carcinoids should be mandatory, even if they show no hypermetabolism on FDG PET images.