Inhibition of dentin matrix‐bound cysteine cathepsins by potassium fluoride

Matrix metalloproteinases (MMPs) and cysteine cathepsins (CCs) can break down unprotected type I collagen fibrils in dentin matrix. This study investigated the use of potassium fluoride (KF) as a potential inhibitor of MMPs and CCs in dentin. Demineralized dentin beams were divided into groups (n = 10 in each group) and incubated in artificial saliva (AS, control), either alone or with one of seven concentrations of KF (6–238 mM fluoride) for 1, 7, and 21 d. After 21 d, all groups were further aged in AS for 6 months. Total MMP activity was screened using the colorimetric MMP assay. The activities of MMP‐2 and MMP‐9 were investigated using gelatin zymography. At the end of each incubation, changes in loss of dry mass and CC‐mediated or total dissolution of collagen peptides were measured via precision weighing, C‐terminal crosslinked telopeptide of type I collagen (CTX), and hydroxyproline (HYP) assays. The beams were examined using scanning electron microscopy. After 21 d, total MMP activities, dry mass loss, and CTX release for the groups exposed to 179 and 238 mM fluoride were significantly lower compared with the control group. After 6 months, all groups showed similar total MMP activity, dry mass loss, and HYP release, and CTX levels were significantly lower when the fluoride concentration was ≥24 mM. Calcium fluoride (CaF₂)‐like precipitates were observed over the beams. In summary, KF significantly inhibited the catalytic activity of dentin matrix‐bound CCs but did not seem to be effective for MMP‐mediated activity.     

IL-17 inhibition in axial spondyloarthritis: current and future perspectives

Introduction: Interleukin (IL)-17 is a proinflammatory cytokine considered to play a significant role in the immunopathogenesis of ankylosing spondylitis (AS)/axial spondyloarthritis (axSpA) as well as of other spondyloarthritides. There is a number of substances targeting IL-17, which are at different stages of development in the axSpA indication.

Areas covered: This review summarizes the current evidence on the role of IL-17 in the pathophysiology of axSpA and provided a comprehensive review of clinical and radiographic outcomes as well as of safety data from studies with IL-17A inhibitors secukinumab and ixekizumab. Ongoing studies on other IL-17 inhibitors (bimekizumab, brodalumab and BCD-085) that are being developed are also summarized.

Expert opinion: The development of the IL-17 inhibitors has expanded AS treatment with effective options and confirmed the pathophysiological role of IL-17 in axSpA. IL-17 inhibition showed sufficient efficacy against signs and symptoms of the disease even after the failure of tumor necrosis factor inhibitors, being at the same time reasonably safe.     

Factors Affecting Morbidity and Mortality in Patients Who Underwent Emergency Operation for Incarcerated Abdominal Wall Hernia

Patients with incarcerated abdominal wall hernias (AWHs) are often encountered in emergency care units. Despite advances in anesthesia, antisepsis, antibiotic therapy, and fluid therapy, the morbidity and mortality rates for these patients remain high. Between 2006 and 2011, we retrospectively analyzed the cases of 131 patients who underwent emergency surgery for incarcerated abdominal wall hernias. Of these, there were 70 women (53.4%) and 61 men (46.6%) with an average age of 63.3 ± 17.4 years (range, 17–91 years). Morbidity was observed in 28 patients (21.4%), and the mortality rate was 2.3%. Intestinal resection, presence of concomitant disease, and general anesthesia were the independent variants that affected morbidity of patients with incarcerated abdominal wall hernias.     

Dye functionalized cryogel columns for reversible lysozyme adsorption

In this study, poly (methyl methacrylate–glycidyl methacrylate) [poly(MMA-GMA)] cryogels were prepared by radical cryocopolymerization of MMA with GMA as a functional comonomer. Reactive Green 19 dye was then attached to the cryogel by nucleophilic substitution reaction, and this dye-attached cryogel column was used for lysozyme adsorption. Characterization of the cryogel was performed by Fourier transform infrared spectroscopy, environmental scanning electron microscopy, Brunauer–Emmett–Teller, and energy dispersive X-ray analysis. Pore size of the cryogels was 15–30?μm and pores were interconnected structure. Attached amount of Reactive Green 19 to cryogel support was calculated as 106.25?μmol/g cryogel. Lysozyme adsorption studies were carried out by using a continuous system. It was found that the maximum amount of lysozyme adsorption (32?mg/g cryogel) obtained from experimental results was found to be approximately same with the calculated Langmuir adsorption capacity (33?mg/g cryogel). Desorption of adsorbed lysozyme was carried out by using 1.5?M NaCl in pH 4.5 acetate buffer, and desorption yield was found to be 97.4%. Cryogels were very stable, and it was found that there was no remarkable reduction in the adsorption capacity at the end of ten adsorption–desorption cycles. As a result, Reactive Green 19-attached cryogels have great advantages such as easy preparation, rapid adsorption, and desorption, being economic and allowing the direct separation of proteins.