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The heat shock response (HSR) is a universal mechanism of cellular adaptation to elevated temperatures and is regulated by heat shock transcription factor 1 (HSF1) or HSF3 in vertebrate endotherms, such as humans, mice, and chickens. We here showed that HSF1 and HSF3 from egg-laying mammals (monotremes), with a low homeothermic capacity, equally possess a potential to maximally induce the HSR, whereas either HSF1 or HSF3 from birds have this potential. Therefore, we focused on cellular adaptation to daily temperature fluctuations and found that HSF1 was required for the proliferation and survival of human cells under daily temperature fluctuations. The ectopic expression of vertebrate HSF1 proteins, but not HSF3 proteins, restored the resistance in HSF1-null cells, regardless of the induction of heat shock proteins. This function was associated with the up-regulation of specific HSF1-target genes. These results indicate the distinct role of HSF1 in adaptation to thermally fluctuating environments and suggest association of homeothermic capacity with functional diversification of vertebrate HSF genes. [ABSTRACT FROM AUTHOR]

Silver diamine fluoride (SDF) is a highly effective topical fluoride for halting dental caries; however, it darkens both teeth and restorations. Therefore, it is of interest to assess the shear bond strength (SBS) of glass ionomer cement (GIC) to caries-affected dentin treated with SDF alone and SDF followed by KI. Forty primary molar samples were prepared to reveal a flat dentin surface and were randomly assigned to two groups. In group A, the dentin surfaces were pre-treated with 38% SDF, while in group B, the dentin was treated first with SDF and then with KI before being restored with GIC. The SBS was measured using a universal testing machine. The results show that teeth pre-treated with both SDF and KI demonstrated significantly improved bond strength of GIC to dentin compared to SDF treatment alone., (© 2024 Biomedical Informatics.)