Quantitative in vivo biocompatibility of new ultralow‐nickel cobalt–chromium–molybdenum alloys

Nickel (Ni) eluted from metallic biomaterials is widely accepted as a major cause of allergies and inflammation. To improve the safety of cobalt–chromium–molybdenum (Co–Cr–Mo) alloy implants, new ultralow‐Ni Co–Cr–Mo alloys with and without zirconium (Zr) have been developed, with Ni contents of less than 0.01%. In the present study, we investigated the biocompatibility of these new alloys in vivo by subcutaneously implanting pure Ni, conventional Co–Cr–Mo, ultralow‐Ni Co–Cr–Mo, and ultralow‐Ni Co–Cr–Mo with Zr wires into the dorsal sides of mice. After 3 and 7 days, tissues around the wire were excised, and inflammation; the expression of IL‐1β, IL‐6, and TNF‐α; and Ni, Co, Cr, and Mo ion release were analyzed using histological analyses, qRT‐PCR, and inductively coupled plasma mass spectrometry (ICP‐MS), respectively. Significantly larger amounts of Ni eluted from pure Ni wires than from the other wires, and the degree of inflammation depended on the amount of eluted Ni. Although no significant differences in inflammatory reactions were identified among new alloys and conventional Co–Cr–Mo alloys in histological and qRT‐PCR analyses, ICP‐MS analysis revealed that Ni ion elution from ultralow‐Ni Co–Cr–Mo alloys with and without Zr was significantly lower than from conventional Co–Cr–Mo alloys. Our study, suggests that the present ultralow‐Ni Co–Cr–Mo alloys with and without Zr have greater safety and utility than conventional Co–Cr–Mo alloys. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1505–1513, 2016.     

PREGS induces LTP in the hippocampal dentate gyrus of adult rats via the tyrosine phosphorylation of NR2B coupled to ERK/CREB [corrected] signaling

An acute application of neurosteroid pregnenolone sulfate (PREGS) to hippocampal slices from adult rats induced a long-lasting potentiation (LLP PREGS) at the perforant path-granule cell synapse. As a partial mechanism of the LLP PREGS, we previously revealed that PREGS transiently increases the probability of presynaptic glutamate release via a sensitization of alpha7-nicotinic acetylcholine receptor (alpha7nAChR). We herein demonstrate that the LLP PREGS could be separated into two independent processes: the above-mentioned early presynaptic-origin short-term potentiation (STP PREGS) and a delayed postsynaptic N-methyl-d-aspartate receptor (NMDAr)-dependent long-term potentiation termed LTP(PREGS). This study focused on the analysis of the signaling mechanism underlying the LTP PREGS. PREGS increased the tyrosine phosphorylation of NR2B, a subunit of NMDAr, and the NMDAr-mediated Ca2+ influx in the granule cells. The enhanced Ca2+ influx was largely attenuated by the NR2B subunit inhibitor ifenprodil and the Src kinase family inhibitor PP2. PREGS also triggered a persistent phosphorylation of extracellular signal-regulated kinase 2 (ERK2) followed by an ERK-dependent phosphorylation of cAMP-response element-binding protein (CREB), which was crucial for the LTP PREGS induction and was sensitive to ifenprodil. These results suggest that PREGS induces an acute increase in the NR2B tyrosine phosphorylation which enhances the Ca2+ influx through NMDAr, followed by an activation of the ERK/CREB signaling cascade that leads to LTP PREGS.     

Characterization of inter-tissue and inter-strain variability of TCE glutathione conjugation metabolites DCVG,DCVC, and NAcDCVC in the mouse

Trichloroethylene (TCE) is a ubiquitous environmental toxicant that is a liver and kidney carcinogen. Conjugation of TCE with glutathione (GSH) leads to formation of nepthrotoxic and mutagenic metabolites postulated to be critical for kidney cancerdevelopment; however, relatively little is known regarding their tissue levels as previous analytical methods for their detection lacked sensitivity. Here, an LC-MS/MS-based method for simultaneous detection of S-(1,2-dichlorovinyl)-glutathione (DCVG), S-(1,2-dichlorovinyl)-L-cysteine (DCVC), and N-acetyl-S-(1,2-dichlorovinyl)-L-cysteine (NAcDCVC) in multiple mouse tissues was developed. This analytical method is rapid, sensitive (limits of detection (LOD) 3–30 fmol across metabolites and tissues), and robust to quantify all three metabolites in liver, kidneys, and serum. The method was used to characterize inter-tissue and inter-strain variability in formation of conjugative metabolites of TCE. Single oral dose of TCE (24, 240 or 800 mg/kg) was administered to male mice from 20 inbred strains of Collaborative Cross. Inter-strain variability in the levels of DCVG, DCVC, and NAcDCVC (GSD = 1.6–2.9) was observed. Whereas NAcDCVC was distributed equally among analyzed tissues, highest levels of DCVG were detected in liver and DCVC in kidneys. Evidence indicated that inter-strain variability in conjugative metabolite formation of TCE might affect susceptibility to adverse health effects and that this method might aid in filling data gaps in human health assessment of TCE.     

Traumatic unilateral temporomandibular joint dislocation overlooked for more than two decades

Forward dislocation of the temporomandibular joint commonly can be easily diagnosed and successfully reduced by manual repositioning. In this report, we discuss a rare case of prolonged temporomandibular dislocation that had persisted for more than 20 years because the otolaryngologist and dentist had missed the dislocation. This patient underwent open reduction and mandibular joint plasty with preoperative orthodontic therapy. It is possible that strong pain and mouth-closing disability may gradually remit and only deviated mandibular prognathism like malocclusion may persist. Therefore, abnormal occlusion warrants careful attention to temporomandibular joint dislocation.     

Prognostic Significance of Hiatal Hernia in Patients with Gastric Cancer Located within the Upper-Third of the Stomach

World Journal of Surgery - Gastric cancers located within the upper-third of the stomach (UGC), especially the esophagogastric junction GC (EGJGC), have distinct clinicopathological features due to...     

A patient with seminal vesiculitis prior to acute chlamydial epididymitis

This is the first report of a case of seminal vesiculitis prior to acute chlamydial epididymitis. At the first visit to the clinic, the patient wished to check whether he had Chlamydia trachomatis in his genital tract, because his wife had been diagnosed as having chlamydial cervicitis. He had no specific symptoms at that time; however, transrectal ultrasonograpy (TRUS) revealed swelling of seminal vesicles, which suggested the presence of seminal vesiculitis. Two days after the first visit, he had high-grade fever and was diagnosed as having acute epididymitis caused by C. trachomatis. We had previously reported that seminal vesiculitis was always complicated with acute epididymitis, so this case could provide important evidence that seminal vesiculitis might precede acute epididymitis. It suggested that acute epididymitis could be affected by seminal vesiculitis via the retrograde transmission route.     

Long-Term Results of Seton Placement for Fistula-in-ano in Infants

Background

The present study aimed to assess the long-term results of seton placement for fistula-in-ano (FIA) in infants.

Methods

Data of patients aged <1 year who presented to our department with perianal abscess (PA) between January 2006 and February 2010 were retrospectively reviewed. Our standard initial treatment for PA was incision and drainage. Patients with systemic diseases and inflammatory bowel diseases were excluded.

Results

Ninety-five patients were treated for PA and/or FIA during the 5-year period, and follow-up data were available for 90 patients. The mean follow-up duration in these patients was 49.8?±?11.4 months, and mean age at presentation was 3.1?±?2.7 months. Of the 90 patients, 36 (40 %) developed FIA (39 lesions) and underwent seton placement. The condition healed in a mean period of 6.3?±?4.0 weeks after the placement of a cutting seton. Healing of the fistula was achieved in 35 (97.2 %) of 36 patients after the initial seton procedure, and one patient who showed recurrence underwent a second seton placement, resulting in successful healing of the FIA after 5 weeks.

Conclusions

The long-term success of seton placement indicates that this procedure should be a treatment option for FIA in infants.