Lack of in vitro constitutive activity for four previously reported TSH receptor mutations identified in patients with nonautoimmune hyperthyroidism and hot thyroid carcinomas

Objective Constitutively activating mutations (CAMs) of the TSHR are the major cause for nonautoimmune hyperthyroidism. Re‐examination of constitutive activity previously determined in CHO cell lines recently demonstrated the caveats for the in vitro determination of constitutive TSHR activity, which leads to false positive conclusions regarding the molecular origin of hyperthyroidism or hot thyroid carcinomas. Design Mutations L677V and T620I identified in hot thyroid carcinomas were previously characterized in CHO and in 3T3‐Vill cell lines, respectively, stably expressing the mutant without determination of TSHR expression. F666L identified in a patient with hot thyroid nodules, I691F in a family with nonautoimmune hyperthyroidism and F631I identified in a hot thyroid carcinoma were not characterized for their in vitro function. Therefore, we decided to (re)evaluate the in vitro function of these five TSHR variants by determination of cell surface expression, and intracellular cAMP and inositol phosphate levels and performed additionally linear regression analyses to determine basal activity independently from the mutant’s cell surface expression in COS‐7 and HEK_GT cells. Results and Conclusions Only one (F631I) of the five investigated TSHR variants displayed constitutive activity for G_αs signalling and showed correlation with the clinical phenotype. The previous false classification of T620I and L677V as CAMs is most likely related to the fact that both mutations were characterized in cell lines stably expressing the mutated receptor construct without assessing the respective receptor number per cell. Other molecular aetiologies for the nonautoimmune hyperthyroidism and/or hot thyroid carcinomas in these three patients and one family should be elucidated.     

A Cell-Free Collagen Type I Device for the Treatment of Focal Cartilage Defects

The purpose of this study was to evaluate the potential value of a cell-free collagen type I gel plug for the treatment of focal cartilage defects. Cellular migration and proliferation was addressed in vitro, and the formation of repair tissue in a nude mouse-based defect model. A cell-free plug made of collagen type I was placed in the center of an incubation plate. Surrounding space was filled with a collagen type I gel (Arthro Kinetics, Esslingen, Germany) seeded with 2 × 10⁵ human articular chondrocytes/mL gel. After cultivation for up to 6 weeks in vitro, samples were subject to histological and immunohistochemical staining and gene expression analysis. Subsequently, chondral defects of human osteochondral blocks were treated with the plug, and specimens were cultivated subcutaneously in nude mice for 6 weeks. The repair tissue was evaluated macroscopically, and collagen type II production was investigated immunohistochemically. In vitro, morphology of immigrated cells did not show any differences, as did collagen type II gene expression. After 4 weeks, the plug was homogeneously inhabited. After 6 weeks of cultivation in nude mice, collagen gel plug treatment led to a macroscopically excellent repair tissue. Histological staining revealed a tight bonding, and the collagen gel plug started to be remodeled. We conclude that the novel collagen gel plug device offers an environment favorable for the migration of articular chondrocytes and leads to a good-quality repair tissue in the nude mouse model. The arthroscopic transplantation of a collagen gel plug may be one option in the treatment of focal cartilage defects.     

Ten reasons to oppose the criminalization of HIV exposure or transmission

Recent years have seen a push to apply criminal law to HIV exposure and transmission, often driven by the wish to respond to concerns about the ongoing rapid spread of HIV in many countries. Particularly in Africa, some groups have begun to advocate for criminalization in response to the serious phenomenon of women being infected with HIV through sexual violence or by partners who do not reveal their HIV diagnoses to them. While these issues must be urgently addressed, a closer analysis of the complex issues raised by criminalization of HIV exposure or transmission reveals that criminalization is unlikely to prevent new infections or reduce women's vulnerability to HIV. In fact, it may harm women rather than assist them, and have a negative impact on public health and human rights. This paper is a slightly revised version of a document originally released in December 2008 by a coalition of HIV, women's and human rights organizations. It provides ten reasons why criminalizing HIV exposure or transmission is generally an unjust and ineffective public policy. The obvious exception involves cases where individuals purposely or maliciously transmit HIV with the intent to harm others. In these rare cases, existing criminal laws – rather than new, HIV-specific laws – can and should be used.