Role of the Thyroid Gland in Expression of the Thyroid Phenotype of Sbp2-Deficient Mice

Selenocysteine insertion sequence-binding protein 2, SBP2 (SECISBP2), is required for selenoprotein synthesis. Partial SBP2 deficiency syndrome manifests characteristic thyroid function tests. The Sbp2 deficiency mouse model, Sbp2 inducible conditional knockout (iCKO), replicates this thyroid phenotype and was used for pathophysiologic investigations. As selenoproteins have an antioxidative role in thyroid gland function, their deficiencies have potential to affect thyroid hormone (TH) synthesis. Sbp2 iCKO mice had larger thyroids relative to body weight and increased thyroidal thyroxine (T4) and triiodothyronine (T3) content while 5' deiodinases enzymatic activities were decreased. Possible mechanisms for the discrepancy between the increased thyroidal T3 and normal circulating T3 were investigated in dynamic experiments. Treatment with bovine thyroid-stimulating hormone (TSH) resulted in increased delta T4 in Sbp2 iCKO mice, indicating increased availability of preformed thyroidal TH. Next, the recovery of TH levels was evaluated after withdrawal of chemical suppression. At one day, Sbp2 iCKO mice had higher serum and thyroidal T3 concomitant with lower TSH, confirming increased capacity of TH synthesis in Sbp2 deficiency. Decreased TH secretion was ruled out as serum and thyroidal TH were high in Sbp2 iCKO mice. Treatment with a low-iodine diet also ruled out thyroidal secretion defect as both serum levels and thyroidal TH content similarly declined over time in Sbp2-deficient mice compared to wild-type (Wt) mice. This study provides evidence for unsuspected changes in the thyroid gland that contribute to the thyroid phenotype of Sbp2 deficiency, with increased thyroidal T4 and T3 content in the setting of increased TH synthesis capacity contributing to the circulating TH levels while thyroidal secretion is preserved.

Diagnostic study of FMD virus in different area in Iraq

Seventy four (74) samples from cattle, buffalo, goat and sheep were tested to isolatethe FMD virus, 23 isolates of the virus showed Cytopathic Effect (CPE) on the different typesof cell culture. The CPE appears after 24 hours on fetal lamb kidney (FLK) cells, 48 hours on the fetalbovine kidney (FBK), 30 hours on primary Fetal Bovine Thyroid cell (BTY) and 20 hours onthe primary fetal ovine thyroid cells (OTY). Solid phase ELISA test showed three serotypesof FMD virus O, A and Asia1. One step real time RT-PCR for the diagnosis of FMDV byusing 5UTR FMDV primers and taqman probe (SA-IR-219-246F, SA-IR-315-293R andSAmulti2-P-IR-292-269R). Samples were tested, showed 23 positive machines by using theApplied Biosystem Fast 7500 real time PCR.