手术导航系统辅助下放射粒子植入治疗眶尖周、颅底肿瘤的探索

目的:将手术导航系统与放射性粒子内照射治疗相结合,探索更高精度植入125I放射粒子的方法,从而更加安全有效地控制已累及颅底及眶尖周的口腔颌面部恶性肿瘤。方法:肿瘤侵及颅底、眶尖周的腺样囊性癌患者11例,术前进行MRI扫描。术中运用BrainLAB手术导航系统定位并引导手术进行。结果:术中避免了颅脑及眶内组织损伤。完成了放射粒子组织内均匀分布,定位准确,无一例出现颅脑损伤及视力影响,治疗有效率(response rate,RR)达100%,疗效确切。结论:手术导航系统辅助下进行颅底眶尖周放射粒子植入是精确、安全的,有条件的情况下可考虑采用。     

Osteolysis around total knee arthroplasty: A review of pathogenetic mechanisms

Aseptic loosening and other wear-related complications are some of the most frequent late reasons for revision of total knee arthroplasty (TKA). Periprosthetic osteolysis (PPOL) pre-dates aseptic loosening in many cases, indicating the clinical significance of this pathogenic mechanism. A variety of implant-, surgery- and host-related factors have been delineated to explain the development of PPOL. These factors influence the development of PPOL because of changes in mechanical stresses within the vicinity of the prosthetic device, excessive wear of the polyethylene liner, and joint fluid pressure and flow acting on the peri-implant bone. The process of aseptic loosening is initially governed by factors such as implant/limb alignment, device fixation quality and muscle coordination/strength. Later, large numbers of wear particles detached from TKA trigger and perpetuate particle disease, as highlighted by progressive growth of inflammatory/granulomatous tissue around the joint cavity. An increased accumulation of osteoclasts at the bone–implant interface, impairment of osteoblast function, mechanical stresses and increased production of joint fluid contribute to bone resorption and subsequent loosening of the implant. In addition, hypersensitivity and adverse reactions to metal debris may contribute to aseptic TKA failure, but should be determined more precisely. Patient activity level appears to be the most important factor when the long-term development of PPOL is considered. Surgical technique, implant design and material factors are the most important preventative factors, because they influence both the generation of wear debris and excessive mechanical stresses. New generations of bearing surfaces and designs for TKA should carefully address these important issues in extensive preclinical studies. Currently, there is little evidence that PPOL can be prevented by pharmacological intervention.     

Foreign Bodies in Facial Trauma-Report of 3 Cases

Background

Foreign bodies embedded deep in facial tissues presents a challenge to maxillofacial surgeons. Approximately one third of all foreign bodies are missed during initial examination. After facial trauma foreign bodies like grit particles, wooden pieces, thorns, pebbles, glass particles may get embedded into deeper facial tissues which are detected only accidently either with the help of radiographs or at a later stage when patient presents with some signs & symptoms like pain, pus discharge, sinus formation etc. Trauma to maxillofacial region especially after road traffic accidents is one of major cause of embedment of foreign body, but many of these cases go unnoticed. This article contains 3 cases of foreign bodies embedded in facial tissues.

Conclusion

Proper initial examination of facial lacerations with thorough debridement is very essential for finding embedded foreign bodies. Foreign bodies embedded in deeper tissues are missed by surgeon eyes, so whenever in doubt radiographs must be advised to rule out presence of foreign bodies.     

No bone ingrowth into the tibia tunnel in anterior cruciate ligament-reconstructed patients: A 1-year prospective quantified CT study of 10 patients reconstructed with an autologous bone-patellar tendon-bone graft

10 patients with major instability symptoms due to an acute anterior cruciate ligament injury were operated on with a bone-patellar tendon-bone reconstruction. Tibial condyle bone mineral density (BMD), bone ingrowth and changes in diameter in the tibia bone tunnel were studied with quantified computed tomography (QCT) postoperatively and after 1, 3, 6 and 12 months. We found no sign of bone ingrowth in the form of increased bone mineral density (BMD) in the bone tunnels in any of the patients. The tunnel diameter increased in all patients during the first postoperative months. After 1 year, 5 patients had a smaller diameter than at the first postoperative examination, 2 had the same diameter as immediately after surgery and 2 patients had a larger diameter. A sclerotic zone developed in all patients along the perimeter of the tunnel during the 3-6 months of follow-up. The BMD in the tibial condyle decreased at 3 months; it then increased, but between 6 and 12 months, it levelled out and was slightly lower than postoperatively. In conclusion, we found no growth of bone into the tunnel and tendinous part of the graft during the first postoperative year.     

Cutaneous applied nano-ZnO reduce the ability of hair follicle stem cells to differentiate

The ability of metal oxide nanoparticles to penetrate the skin has aroused a great deal of interest during the past decade due to concerns over the safety of topically applied sunscreens that contain physical UV-resistant metal particles, such as nano-Zinc oxide (nZnO). Previous studies demonstrate that metal oxide nanoparticles accumulate in skin furrows and hair follicles following topical application while little is known about the consequence of these nanoparticles on skin homeostasis. The current investigation tested the effects of nZnO (0.5?mg/day mouse) on hair follicle physiology. Topical application of Vaseline containing nZnO, bulk ZnO (bZnO), or ionized Zn to newborn mice vibrissa pad over a period of 7 consecutive days revealed that nZnO accumulated within hair follicles, and this induced the apoptosis of hair follicle stem cells (HFSCs). In vitro studies also indicated that nZnO exposure caused obvious DNA damage and induced apoptosis in HFSCs. Furthermore, it was found that nZnO exposure perturbed genes associated with HFSC apoptosis, cell communication, and differentiation. HFSCs transplantation assay demonstrated that the potential of HFSCs to differentiate was reduced. This investigation indicates a potential risk of topically applied ZnO nanoparticles on skin homeostasis.     

Local delivery of mutant CCL2 protein‐reduced orthopaedic implant wear particle‐induced osteolysis and inflammation in vivo

Total joint replacement (TJR) has been widely used as a standard treatment for late‐stage arthritis. One challenge for long‐term efficacy of TJR is the generation of ultra‐high molecular weight polyethylene wear particles from the implant surface that activates an inflammatory cascade which may lead to bone loss, prosthetic loosening and eventual failure of the procedure. Here, we investigate the efficacy of local administration of mutant CCL2 proteins, such as 7ND, on reducing wear particle‐induced inflammation and osteolysis in vivo using a mouse calvarial model. Mice were treated with local injection of 7ND or phosphate buffered saline (PBS) every other day for up to 14 days. Wear particle‐induced osteolysis and the effects of 7ND treatment were evaluated using micro‐CT, histology, and immunofluorescence staining. Compared with the PBS control, 7ND treatment significantly decreased wear particle‐induced osteolysis, which led to a higher bone volume fraction and bone mineral density. Furthermore, immunofluorescence staining showed 7ND treatment decreased the number of recruited inflammatory cells and osteoclasts. Together, our results support the feasibility of local delivery of 7ND for mitigating wear particle‐induced inflammation and osteolysis, which may offer a promising strategy for extending the life time of TJRs. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:58–64, 2016.     

Oral immunization with different assembly forms of the HPV 16 major capsid protein L1 induces neutralizing antibodies and cytotoxic T-lymphocytes

Human papillomaviruses have been recognized as the causative agent of anogenital cancer. In 2006, a commercial vaccine based on virus-like particles composed of the L1 major capsid protein of the papillomaviruses has been available. This vaccine induces virus-neutralizing antibody responses upon parenteral injection. Here we investigated the oral immunogenicity of different assembly forms of HPV 16 L1, that is: T7-VLPs, T1 particles and capsomeres. Our results show that all three assembly forms induce humoral and cellular immune responses after oral vaccination of mice. The anti-L1 antibodies were conformation-specific and showed neutralizing activity in a pseudovirion-based assay. We also investigated if adjuvants have an influence on the oral immunogenicity of the different L1 forms. For saponins we observed a significant toxicity if applied orally. Co-administration of either CpG DNA or Escherichia coli heat-labile enterotoxin LT(R192G) had no apparent enhancing effect on the production of anti-L1 antibodies. More pronounced was the effect of CpG administration on the long-term immunity as we observed a significantly stronger recall response 244 days after the first vaccination. Compared to capsomeres, VLPs induced stronger humoral immune responses while the CTL responses were induced at comparable levels. Finally, we were also able to induce neutralizing antibodies and L1-specific cytotoxic T-lymphocytes after oral administration of crude extracts of L1-expressing insect cells. In conclusion, all three assembly forms of the L1 protein are immunogenic when administered orally.     

An indoor air quality evaluation in a residential retrofit project using spray polyurethane foam

Understanding of indoor air quality (IAQ) during and after spray polyurethane foam (SPF) application is essential to protect the health of both workers and building occupants. Previous efforts such as field monitoring, micro-chamber/spray booth emission studies, and fate/transport modeling have been conducted to understand the chemical exposure of SPF and guide risk mitigation strategies. However, each type of research has its limitation and can only reveal partial information on the relationship between SPF and IAQ. A comprehensive study is truly needed to integrate the experimental design and analytical testing methods in the field/chamber studies with the mathematical tools employed in the modeling studies. This study aims to bridge this gap and provide a more comprehensive understanding on the impact of SPF to IAQ. The field sampling plan of this research aims to evaluate the airborne concentrations of methylene diphenyl diisocyanate (MDI), formaldehyde, acetaldehyde, propionaldehyde, tris(1-chlor-2-propyl)phosphate (TCPP), trans-1-chloro-3,3,3-trifluoropropene (Solstice^TM), and airborne particles. Modifications to existing MDI sampling and analytical methods were made so that level of quantification was improved. In addition, key fate and transport modeling input parameters such as air changes per hour and airborne particle size distribution were measured. More importantly, TCPP accumulation onto materials was evaluated, which is important to study the fate and transport of semi-volatile organic compounds. The IAQ results showed that after spray application was completed in the entire building, airborne concentrations decreased for all chemicals monitored. However, it is our recommendation that during SPF application, no one should return to the application site without proper personal protection equipment as long as there are active spray activities in the building. The comparison between this field study and a recent chamber study proved surface sorption and particle deposition is an important factor in determining the fate of airborne TCPP. The study also suggests the need for further evaluation by employing mathematical models, proving the data generated in this work as informative to industry and the broader scientific community.     

In-Room Ultraviolet Air Filtration Units Reduce Airborne Particles During Total Joint Arthroplasty

Reducing airborne bioburden in total joint arthroplasty (TJA) is of critical importance. The efficacy of crystalline ultraviolet-C (C-UVC) filtration in reducing bioburden in a dynamic operating room (OR) environment has not been evaluated. We assessed whether C-UVC filtration reduced (i) total particle counts (TPC); (ii) viable particle counts (VPC); and (iii) colony-forming units (CFUs). Fifty primary TJA cases were performed in a positive-pressure OR; 25 cases with the C-UVC unit and 25 cases without. The air was sampled by a particle counter and an impact air sampler to measure particle counts and CFUs, respectively. To compare TPC, VPC, and CFU/m³ between groups, independent t tests and multivariate regression, adjusted for number of OR staff and door openings, were performed. The C-UVC group had significantly lower TPC (2.6 × 10⁶ vs. 4.7 × 10⁶ particles, p = 0.001) and VPC (18,605 vs. 27,516 particles, p = 0.001). There were fewer CFUs in the C-UVC group (10.9 CFU/m³ vs. 13.7 CFU/m³, p = 0.163). Multivariate analysis identified C-UVC filtration as a significant predictor of decreased TPC (β = −0.44, p = 0.002) and VPC (β = −0.47, p = 0.001) after accounting for door openings and number of OR staff. The reduction in CFUs was not significant on multivariate analysis. In this prospective pilot study, a C-UVC air disinfection and recirculation unit led to a significant reduction in both TPC and VPC and a non-significant reduction in CFU. Statement of clinical significance: Further studies are needed to investigate the effects of C-UVC filtration units on surgical-site infection rates. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:431-437, 2020