RESUMEN
The binding of ferulic acid (FA) with sodium deoxycholate (NaDC) has been investigated using fluorescence and absorption measurements. The fluorescence probe technique of pyrene reveals that the presence of FA favors the micellization of NaDC, leading to the decreased critical micelle concentrations for the formation of NaDC micelles. As NaDC molecules change gradually from monomers via primary micelles into secondary micelles, the intensities of absorption and fluorescence spectra of FA increase at low NaDC concentrations, but decrease suddenly at intermediate NaDC concentrations, and finally increase again at high NaDC concentrations. These results corroborated well with FA fluorescence lifetime data suggesting that the aryl ring of FA hydrophobically binds to the convex surface of NaDC monomers, whereas the hydrogen bonding between FA and NaDC is significantly involved in NaDC primary micelles, which is gradually overcome by the hydrophobic interaction between FA and NaDC secondary micelles. The absorption and fluorescence spectra as well as the binding constant value of FA indicate the strong binding of FA in the large hydrophobic core of NaDC secondary micelles. At low FA concentrations, the measurement of FA anisotropy suggests that FA can increase the packing order of hydrophobic surfaces in NaDC secondary micelles, whereas the high amount of FA can greatly disrupt the packing structure of NaDC secondary micelles which is ascribed to the formation of FA dimers. The spectroscopic experiments outlined here present the binding events of FA with NaDC monomers and primary and secondary micelles, which are significantly related with the hydrophobic force and hydrogen bonding as well as the unique structural characteristics of bile salt.
RESUMEN
RATIONALE: A solitary fibrous tumor (SFT) is an uncommon soft tissue tumor that was first discovered in the pleura. Although SFTs have been documented in other extra-pleural sites, an SFT in the thyroid gland is highly unusual. An SFT of the thyroid gland can be difficult to diagnose, and there is little information about their Underlying biological behavior. PATIENT CONCERNS: We present a case of a 63-year-old man with a progressively growing left-neck mass detected 1 month ago, which was pathologically confirmed to be a benign SFT of the thyroid gland. DIAGNOSIS: Postoperative pathological examination of the tumor revealed an SFT. Immunopathological examination was consistent with the diagnosis of an SFT. INTERVENTIONS: The patient underwent surgical resection of the SFT. OUTCOMES: The patient was recurrence-free during 1.5 years of follow-up. LESSONS: Surgical excision is beneficial in SFTs that show no histological signs of malignancy, such as pleomorphism, enhanced mitotic activity, necrosis, bleeding, or capsular invasion. However, because the biologic activity remains unknown, meticulous long-term monitoring is required.