Assessment of the value of quantitative thyroid scintigraphy for determination of thyroid function in dogs.

OBJECTIVE: To assess the value of thyroid scintigraphy to determine thyroid status in dogs with hypothyroidism and various non-thyroidal illnesses. METHODS: Thyroid hormone concentrations were measured and quantitative thyroid scintigraphy performed in 21 dogs with clinical and/or clinicopathological features consistent with hypothyroidism. RESULTS: In 14 dogs with technetium thyroidal uptake values consistent with euthyroidism, further investigations supported non-thyroidal illness. In five dogs with technetium thyroidal uptake values within the hypothyroid range, primary hypothyroidism was confirmed as the only disease in four. The remaining dog had pituitary-dependent hyperadrenocorticism. Two dogs had technetium thyroidal uptake values in the non-diagnostic range. One dog had iodothyronine concentrations indicative of euthyroidism. In the other, a dog receiving glucocorticoid therapy, all iodothyronine concentrations were decreased. Markedly asymmetric technetium thyroidal uptake was present in two dogs. All iodothyronine concentrations were within reference interval but canine thyroid stimulating hormone concentration was elevated in one. Non-thyroidal illness was identified in both cases. CLINICAL SIGNIFICANCE: In dogs, technetium thyroidal uptake is a useful test to determine thyroid function. However, values may be non-diagnostic, asymmetric uptake can occur and excess glucocorticoids may variably suppress technetium thyroidal uptake and/or thyroid hormone concentrations. Further studies are necessary to evaluate quantitative thyroid scintigraphy as a gold standard method for determining canine thyroid function.

Short communication: Biological and genetic characterization of HIV type 1 subtype B and nonsubtype B transmitted viruses: usefulness for vaccine candidate assessment.

Due to the extraordinary degree of genetic diversity of HIV-1 and the structural complexity of its envelope glycoproteins, designing an effective vaccine is difficult, requiring the development of viral reagents to assess vaccine-elicited neutralizing antibodies. The aim of this study was to improve on our previously developed panel of HIV-1 strains of different genetic forms, focusing on strains from acute and recently acquired infections as the most representative of the transmitted viruses. HIV-1 primary isolates were expanded in peripheral blood mononuclear cells. Viral stocks of 40 ml each were produced. Syncytium-inducing (SI) phenotype, coreceptor use, and TCID(50)/ml were determined. Near full-length HIV-1 genomes were amplified by RT-nested PCR in four overlapping segments. Phylogenetic analyses were performed with neighbor-joining trees and bootscanning. Forty-four HIV-1 strains were included in the panel. Twenty-four (54.1%) strains were from early infections (16 acute and 8 recent); of them, 21 (87%) were sexually transmitted. NSI/R5 phenotype was detected in 37 (84.1%) viruses and SI/R5,X4 in another 7 (15.9%). TCID(50)/ml ranged between 10(4) and 10(6.6). Twelve different genetic forms constituted this panel: subtypes A1, B, C, F1, and G; circulating recombinant forms CRF02_AG, CRF14_BG, and CRF24_BG; and unique recombinant forms CRF02_AG/A3, BF1, CRF12_BF/B, and DF1G. In conclusion, in this study, we report the development of a comprehensive and well-characterized panel of HIV-1 isolates for assessing neutralization in HIV vaccine research. This panel is available for distribution through the Programme EVA Centre for AIDS Reagents, National Institute for Biological Standard and Control (NIBSC).