Anti-tumor effects induced by gene vaccines co-expressing truncated human prostate specific membrane antigen gene and mouse 4-1BBL

Objective To investigate the influence of m4-1BBL on anti-tumor effects induced by truncated human prostate specific membrane antigen ( tPSMA ) gene in mice. Methods A eukaryotic expression plasmid encoding tPSMA and m4-1BBL ( pDC316-tPSMA-IRES m4-1BBL) ,pDC316-tPSMA and pDC316 were constructed.

Masquelet technique in military practice:specificities and future directions for combat-related bone defect reconstruction

Because of its simplicity,reliability,and replicability,the Masquelet induced membrane technique(IMT)has become one of the preferred methods for critical bone defect reconstruction in extremities.Although it is now used worldwide,few studies have been published about IMT in military practice.Bone reconstruction is particularly challenging in this context of care due to extensive soft-tissue injury,early wound infection,and even delayed management in austere conditions.Based on our clinical expertise,recent research,and a literature analysis,this narrative review provides an overview of the IMT application to combat-related bone defects.It presents technical specificities and future developments aiming to optimize IMT outcomes,including for the management of massive multi-tissue defects or bone reconstruction performed in the field with limited resources.

Role of the Ilizarov non-free bone plasty in the management of long bone defects and nonunion: Problems solved and unsolved

BACKGROUND Ilizarov non-free bone plasty is a method of distraction osteogenesis using the Ilizarov apparatus for external fixation which originated in Russia and was disseminated across the world. It has been used in long bone defect and nonunion management along with free vascularized grafting and induced membrane technique. However, the shortcomings and problems of these methods still remain the issues which restrict their overall use.AIM To study the recent available literature on the role of Ilizarov non-free bone plasty in long bone defect and nonunion management, its problems and the solutions to these problems in order to achieve better treatment outcomes.METHODS Three databases(Pub Med, Scopus, and Web of Science) were searched for literature sources on distraction osteogenesis, free vascularized grafting and induced membrane technique used in long bone defect and nonunion treatment within a five-year period(2015-2019). Full-text clinical articles in the English language were selected for analysis only if they contained treatment results,complications and described large patient samples(not less than ten cases for congenital, post-tumor resection cases or rare conditions, and more than 20 cases for the rest). Case reports were excluded.RESULTS Fifty full-text articles and reviews on distraction osteogenesis were chosen.Thirty-five clinical studies containing large series of patients treated with this method and problems with its outcome were analyzed. It was found that distraction osteogenesis techniques provide treatment for segmental bone defects and nonunion of the lower extremity in many clinical situations, especially in complex problems. The Ilizarov techniques treat the triad of problems simultaneously(bone loss, soft-tissue loss and infection). Management of tibial defects mostly utilizes the Ilizarov circular fixator. Monolateral fixators are preferable in the femur. The use of a ring fixator is recommended in patients with an infected tibial bone gap of more than 6 cm. High rates of successful treatment were reported by the authors that ranged from 77% to 100% and depended on the pathology and the type of Ilizarov technique used. Hybrid fixation and autogenous grafting are the most applicable solutions to avoid after-frame regenerate fracture or deformity and docking site nonunion.CONCLUSION The role of Ilizarov non-free bone plasty has not lost its significance in the treatment of segmental bone defects despite the shortcomings and treatment problems encountered.

Ilizarov bone transport combined with the Masquelet technique for bone defects of various etiologies (preliminary results)

BACKGROUND The Ilizarov bone transport(IBT)and the Masquelet induced membrane technique(IMT)have specific merits and shortcomings,but numerous studies have shown their efficacy in the management of extensive long-bone defects of various etiologies,including congenital deficiencies.Combining their strong benefits seems a promising strategy to enhance bone regeneration and reduce the risk of refractures in the management of post-traumatic and congenital defects and nonunion that failed to respond to other treatments.AIM To combine IBT and IMT for the management of severe tibial defects and pseudarthrosis,and present preliminary results of this technological solution.METHODS Seven adults with post-traumatic tibial defects(subgroup A)and nine children(subgroup B)with congenital pseudarthrosis of the tibia(CPT)were treated with the combination of IMT and IBT after the failure of previous treatments.The mean number of previous surgeries was 2.0±0.2 in subgroup A and 3.3±0.7 in subgroup B.Step 1 included Ilizarov frame placement and spacer introduction into the defect to generate the induced membrane which remained in the interfragmental gap after spacer removal.Step 2 was an osteotomy and bone transport of the fragment through the tunnel in the induced membrane,its compression and docking for consolidation without grafting.The outcomes were retrospectively studied after a mean follow-up of 20.8±2.7 mo in subgroup A and 25.3±2.3 mo in subgroup B.RESULTS The“true defect”after resection was 13.3±1.7%in subgroup A and 31.0±3.0%in subgroup B relative to the contralateral limb.Upon completion of treatment,defects were filled by 75.4±10.6%and 34.6±4.2%,respectively.Total duration of external fixation was 397±9.2 and 270.1±16.3 d,including spacer retention time of 42.4±4.5 and 55.8±6.6 d,in subgroups A and B,respectively.Bone infection was not observed.Postoperative complications were several cases of pin-tract infection and regenerate deformity in both subgroups.Ischemic regeneration was observed in two cases of subgroup B.Complications were corrected during the course of treatment.Bone union was achieved in all patients of subgroup A and in seven patients of subgroup B.One non-united CPT case was further treated with the Ilizarov compression method only and achieved union.After a follow-up period of two to three years,refractures occurred in four cases of united CPT.CONCLUSION The combination of IMT and IBT provides good outcomes in post-traumatic tibial defects after previous treatment failure but external fixation is longer due to spacer retention.Refractures may occur in severe CPT.

Hierarchically Porous Carbon Membranes Derived from PAN and Their Selective Adsorption of Organic Dyes

Porous carbon membranes were favorably fabricated through the pyrolysis of polyacrylonitrile（PAN） precursors, which were prepared with a template-free technique-thermally induced phase separation. These carbon membranes possess hierarchical pores, including cellular macropores across the whole membranes and much small pores in the matrix as well as on the pore walls. Nitrogen adsorption indicates micropores（1.47 and 1.84 nm） and mesopores（2.21 nm） exist inside the carbon membranes, resulting in their specific surface area as large as 1062 m2/g. The carbon membranes were used to adsorb organic dyes（methyl orange, Congo red, and rhodamine B） from aqueous solutions based on their advantages of hierarchical pore structures and large specific surface area. It is particularly noteworthy that the membranes present a selective adsorption towards methyl orange, whose molecular size（1.2 nm） is smaller than those of Congo red（2.3 nm） and rhodamine B（1.8 nm）. This attractive result can be attributed to the steric structure matching between the molecular size and the pore size, rather than electrostatic attraction. Furthermore, the used carbon membranes can be easily regenerated by hydrochloric acid, and their recovery adsorption ratio maintains above 90% even in the third cycle. This work may provide a new route for carbon-based adsorbents with hierarchical pores via a template-free approach, which could be promisingly applied to selectively remove dye contaminants in aqueous effluents.

Modified Masquelet technique in children

Masquelet technique is one of the modalities for the treatment of long bone defect.Using cancellous bone graft to fill the bone defect is always a concern in children due to the small size of their iliac crest and open growth plate.We reported a case of 13-year-old male who presented with gap non-union of middle third of tibia.We applied a modified Masquelet technique by using only the cortical fibular graft instead of cancellous bone to fill the space surrounded by induced membrane.Fibula was used as a nonvascularized strut graft and matched stick graft to achieve complete union.We concluded that nonvascularized fibula grafting is an easy and effective option to fill the bone defect in children in the second stage of Masquelet technique.