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p-Phenylenediamine antioxidants (PPDs) are rubber antioxidants that can suppress oxidation, heat, or light radiation to delay the aging of polymer components and extend the service life of rubber products. In recent years, PPDs have been found in the environment, and their ecological risks remain largely unknown, which cause widespread concern. In this work, a method of gas chromatography-tandem mass spectrometry (GC-MS/MS) with ultrasonic extraction was developed for the determination of PPDs in zebrafish embryos. In order to have good performance, extraction solvents and sorbents were optimized. Under optimal conditions, embryonic samples were combined with 5 mL of dichloromethane and ultrasonically extracted for 15 min. The extraction procedure was repeated twice, after that the resulting extracts were purified by 0.1 g primary secondary amine (PSA). Based on internal standard method, the analytes were detected using GC-MS/MS in selective reaction monitoring (SRM) mode with optimal parameters. The results showed that the chromatographic peaks of analyte were completely separated, and the baseline was smooth. The correlation coefficient (R2) of each analyte exceeded 0.99 in the concentration range of 0.1-200 μg/L. Method detection limits (MDLs) and method quantification limits (MQLs) were in the range of 0.38-0.68 ng/g and 1.28-2.28 ng/g, respectively. Except for the average recovery of N,N′-bis(methylphenyl)-1,4-benzenediamine (DTPD), which was higher than 120%, the average recoveries of N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine (6PPD), N-phenyl-N′-cyclohexyl-p-phenylenediamine (CPPD) and N-isopropyl-N′-phenyl-1,4-phenylenediamine (IPPD) were 73.1%-109%, and the intra-day and inter-day relative standard deviations (RSDs) were 2.97%-15.0% and 4.76%-18.8%, respectively. In order to demonstrate the feasibility of this method, it was applied to detect PPDs in zebrafish embryos exposed to PPDs. The results indicated that PPD concentrations were 12.5-16.4 ng/g. After calculation, the measured bioconcentration factors of each analyte within 48 h were 1.70-33.6 L/kg. These values were much lower than the corresponding predicted bioconcentration factors, because PPD concentrations in vivo had not reached equilibrium during the exposure time of 48 h. This method is simple, sensitive, and suitable for the detection of PPDs in zebrafish embryos, which facilitates future bioaccumulation and toxicity mechanism studies for a comprehensive assessment of the ecological risks of PPDs.

Objective: To investigate the biomechanical effect of different intervertebral reconstructive heights on adjacent segments following C5/C6 anterior cervical discectomy and fusion (ACDF) through finite element analysis. Methods: A finite element model of intact C4–C7 segments was developed and validated for the present study. Five additional C4–C7 postoperative models were constructed with 100%, 125%, 150%, 175%, and 200% of the benchmark height of C5/C6 on the basis of the intact model. The changes in intradiscal pressure (IDP) and range of motion (ROM) of adjacent segments before and after reconstruction of C5/C6 were analyzed. Results: For the upper adjacent segment (C4/C5), the IDPs under the different loading conditions all increased after reconstruction. The maximum IDPs were 0.387, 0.489, 0.491, and 0.472 MPa under flexion, extension, axial rotation, and lateral bending, respectively, observed at the reconstructive height of 200%. The minimum IDPs were observed at 150% reconstructive height under all loading conditions except extension, and were 57, 86 and 81% of the maximum IDPs under flexion, axial rotation, and lateral bending, respectively. The minimum IDP under extension occurred when the reconstructive height is 125% of the benchmark height. For the lower adjacent segment (C6/C7), the IDPs of postoperative models under all loading conditions also increased compared to the preoperative model. The maximum IDPs after reconstruction under flexion, extension, axial rotation, and lateral bending were 0.402, 0.411, 0.461, and 0.497 MPa, respectively, when the height of the reconstruction was 200% of the benchmark. The minimum IDPs were observed after a reconstruction at 150% of the benchmark, and were 59%, 85%, 82%, and 81% of the maximum IDPs under flexion, extension, axial rotation, and lateral bending loading conditions. Conclusions: The reconstructive height is an important factor affecting the IDP and the ROM of adjacent segments after ACDF. To delay the adjacent segment disease, an intervertebral reconstructive height of 150% is an appropriate height in C5/C6 ACDF. [ABSTRACT FROM AUTHOR]

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Background: Primary hypertrophic osteoarthropathy (PHO) is a rare disease related to HPGD and SLCO2A1 gene mutation. Gastrointestinal involvement of PHO is even rarer with unknown pathogenesis. Clinical features of GI complication in PHO mimics other auto-immune based bowel entities, such as inflammatory bowel diseases and cryptogenic multifocal ulcerous stenosing enteritis (CMUSE). We aimed to analyze the clinical, genetic, radiological and pathological features of Chinese patients with PHO and determine the difference between PHO patients presenting with and without GI involvement.Methods: We reported two PHO cases with gastrointestinal involvement and reviewed all the studies of PHO in Chinese population published from January 1, 2000, to April 30, 2018. Clinical and genetic presentations of PHO in Chinese patients were analyzed. We compared the characteristics of those patients with gastrointestinal involvement against those without.Results: The two patients were both males with complete-form PHO for more than 10 years. GI related symptoms included diarrhea, chronic gastrointestinal hemorrhage, incomplete intestinal obstruction, anemia, and edema, which were unresponsive to etoricoxib treatment. Radiological examinations revealed segmental intestinal stenosis and thickened intestinal wall. Endoscopic findings included multiple ulcers and mucosal inflammation. Both patients had mutations of SLCO2A1 according to sequence analysis. The surgical pathology revealed chronic inflammation involving the intestinal mucosa and submucosa, similar to histological changes in CMUSE. According to the systemic review of 158 Chinese patients with PHO, 17.2% had gastrointestinal involvement, including peptic ulcer, gastric polyps, hypertrophic gastritis, and segmental intestinal stenosis. Patients with gastrointestinal involvement were more likely to have anemia (40.0% vs. 4.5%, P < 0.001), hypoalbuminemia (16.7% vs. 0.9%, P = 0.003), and myelofibrosis (19.0% vs. 0.9%, P = 0.002) than those without. Most patients with gastrointestinal complication had SLCO2A1 mutation (86.7%, 13 /15).Conclusions: Digestive tract involvement is uncommon in patients with PHO and often presents with anemia, and hypoalbuminemia resulted from intestinal inflammation. The intestinal pathologic characteristics are distinct from Crohn's disease but similar to CMUSE. Mutations in SLCO2A1 might be the pathogenic cause of GI involvement of PHO. NSAIDs may not be effective for PHO patients with gastrointestinal complications. [ABSTRACT FROM AUTHOR]

Then our multivariate analysis showed that NSAID history (OR 4.83; 95% CI, 2.27-10.27; I P i < 0.001), lack of standardization of EFB number (OR 2.99; 95% CI, 1.91-4.68; I P i < 0.001), >= 1.0 cm maximum diameter of the target adenoma (OR 6.18; 95% CI, 1.32-28.99; I P i = 0.021), lobulated shape (OR 2.68; 95% CI, 1.65-4.36; I P i < 0.001), erythema (OR 2.42; 95% CI, 1.50-3.91; I P i < 0.001), erosion (OR 7.12; 95% CI, 3.91-12.94; I P i < 0.001), surface unevenness (OR 2.31; 95% CI, 1.33-4.01; I P i = 0.003) and distal location of the target adenoma (OR 3.29; 95% CI, 1.68-6.41; I P i < 0.001) were significantly associated with the histologically upgrade discrepancies. Colonoscopists could detect more polyps and adenomas with the aid of the CADe (0.90 vs. 0.82, I P i < 0.001; 0.32 vs. 0.30, I P i <0.05), particularly for polyps <5 mm and for flat polyps (0.65 vs. 0.57, I P i < 0.001; 0.74 vs. 0.67, I P i = 0.001, respectively), but the CADe's efficacy could not be reproduced in patients with inadequate bowel preparation and withdrawal time ( I P i = 0.32; I P i = 0.16, respectively). Twenty-six patients suffered from peri-ampullary perforations, fifteen patients suffered from duodenal wall perforations, one patient suffered from a fundus perforation, one patient suffered from a residual gallbladder duct perforation, one patient suffered from a papillary diverticulum perforation, and one patient suffered from an intrahepatic bile duct perforation. The patients were divided into four groups: 19 patients underwent pharmacologic treatment (drug group); 21 patients were treated with EVL (EVL group); 25 patients were treated with PSE (PSE group); and 22 patients underwent EVL plus PSE (EVL + PSE group). [Extracted from the article]