RESUMO
In the synovial joint, mechanical force creates an important signal that influences chondrocyte behavior. The conversion of mechanical signals into biochemical cues relies on different elements in mechanotransduction pathways and culminates in changes in chondrocyte phenotype and extracellular matrix composition/structure. Recently, several mechanosensors, the first responders to mechanical force, have been discovered. However, we still have limited knowledge about the downstream molecules that enact alterations in the gene expression profile during mechanotransduction signaling. Recently, estrogen receptor α (ERα) has been shown to modulate the chondrocyte response to mechanical loading through a ligand-independent mechanism, in line with previous research showing that ERα exerts important mechanotransduction effects on other cell types, such as osteoblasts. In consideration of these recent discoveries, the goal of this review is to position ERα into the mechanotransduction pathways known to date. Specifically, we first summarize our most recent understanding of the mechanotransduction pathways in chondrocytes on the basis of three categories of actors, namely mechanosensors, mechanotransducers, and mechanoimpactors. Then, the specific roles played by ERα in mediating the chondrocyte response to mechanical loading are discussed, and the potential interactions of ERα with other molecules in mechanotransduction pathways are explored. Finally, we propose several future research directions that may advance our understanding of the roles played by ERα in mediating biomechanical cues under physiological and pathological conditions.
RESUMO
OBJECTIVES: To assess the feasibility of preoperative ultrasound (US)-guided incisional biopsy through a prospective controlled clinical trial. METHODS: This was a prospective, double-arm, single-center study of Chinese patients. Thirty patients were enrolled in the study. Fourteen patients received incisional biopsies for which the choice of biopsy area relied on a clinical evaluation, and 16 patients received incisional biopsies for which the choice of biopsy area relied on a US-guided evaluation. The following procedure was used in the US-guided incisional biopsy group: 1) clinical and dermoscopic evaluation of skin lesions; 2) US examination; 3) incisional biopsy; 4) surgical excision; and 5) histopathological examination. The same procedure was used in the non-US-guided group except without US examination. RESULTS: In the non-US-guided group, the mean tumor thicknesses obtained from incisional biopsy and postoperative histopathological examination were 2.1 and 4.1 mm, respectively. Seven melanomas were underestimated by incisional biopsy, resulting in margins narrower than currently recommended. In the US-guided group, the mean tumor thicknesses obtained from US, incisional biopsy, and postoperative histopathological examination were 3.4, 2.9, and 2.7 mm, respectively. In only 3 melanomas was the tumor thickness of the incisional biopsy less than that of the postoperative histopathological examination, demonstrating that US-guided biopsy obtains the maximum thickness area. CONCLUSIONS: Preoperative US-guided incisional biopsy can enhance the pathological accuracy of incisional biopsy, which may allow us to better perform surgical excision with safe peripheral surgical margins.
