View clinical trials related to Xenograft Model.
Filter by:The present clinical trial will try to demonstrate the efficacy of stable xenogeneic collagen matrix in maintaining the vestibular coronal soft tissue volume and the stabilization of mid-buccal margin position in immediate post-extraccion sockets compared with the use of autogenous connective tissue grafts.
Upper Urinary Tract Urothelial Carcinomas are rare, aggressive tumors, accounting for 5 to 10% of all urothelial tumors. These include tumors which develop in the renal cavities (renal pelvis, calices) and ureteral tumors. Nephro-ureterectomy is the standard treatment but 80% of patients will have a relapse within 2 years. Only one trial has (Birtle et al. 2020), has shown the interest of postoperative chemotherapy. Neoadjuvant systemic treatment seems particularly interesting for a population which is going to undergo a nephronic loss and therefore reduction in kidney function which is likely to make patients ineligible for cisplatin. In favor of additional immunotherapy, it has been described that upper excretory tract tumors have a high immunogenic potential with a high rate of microsatellite instability. From surgical samples of patient tumors obtained after nephroureterectomy or biopsy material collected before treatment, we are going to generate patient-derived cell lines and xenograft models in the mouse. A recent publication has demonstrated the feasibility of this approach by specifying that the capture rate of tumor cells is 50% for patient-derived xenografts and 25% for patient-derived cells (Coleman et al. 2020). As tumors harvested from biopsies do not grow in patient-derived xenografts,we plan to graft the biopsies onto chorioallantoic chicken embryo membranes, a model which has never been used for this indication and which is one of the original features of our approach. These three concomitant approaches will allow us to increase our chances of obtaining stable upper urinary tract urothelial carcinoma lines to be used for the screening and identification of new treatments or new combinations of molecules that would benefit patients with upper urinary tract urothelial carcinomas, knowing that very few studies dedicated to this type of cancer have been conducted or published due to the rarity of the disease and the lack of existing models published on the subject of these particular tumors. .
Papillae tunneling techniques (PTT) are a new approach toward regeneration of isolated intrabony defects. Compared to regular papillae preservation techniques, PTT rely on complete preservation of involved interdental papillae, providing optimal healing environment for periodontal wound. Surgical access is therefore gained either by vertical incision in vestibulum, or by short releasing incision on adjacent tooth. Interdental tissue is then carefully raised in a full thickness manner by tunneling instruments, root surface thoroughly cleaned by the ultrasound scaler or Gracey curettes and defect filled with the biomaterial of choice. While the success and aesthetic results of non-incised papillae techniques are well documented, no paper so far compared clinical results of papillae preservation techniques with different biomaterials. Therefore, the aim of our study is to compare gain of clinical attachment level (defined by sum of pocket probing depth and recession) to regular papillae preservation techniques, and to prove non-inferiority of Gel 40® (collagen matrix, loaded with micronized heterologous bone) to Gen-Os® (granulated cortico-cancellous heterologous bone mix). Secondary objectives include analysis of aesthetic parameters - differences in recession and tip of the papillae location before and after the treatment.
The gold standard for gingival recession treatment is the coronal repositioning of the flap associated with the subepithelial connective tissue graft. The porcine collagen matrix (PCR) has been used as a substitute for subepithelial connective tissue graft in periodontal plastic surgery and has achieved similar results. The PCR use has the advantage of avoiding possible pre and postoperative complications , as well as overcome the limitations presented by autograft . The different surgical techniques used for root coverage seek predictability and success . For this, besides the type of incision placements flap and graft are the most important because the healing benefits and outcome . The aim of this study is to compare two surgical techniques for root coverage and evaluate which one provides better clinical outcomes and less morbidity . 20 adults , nonsmoking patients , showing multiple bilateral gingival recessions , class I or II Miller located in canine, first and second premolars are selected. Both techniques use the PCR as a graft . However, in one Quadrant partial flap will be held together with relaxing incisions through an intrasulcular incision, PCR will be positioned 1 mm apical to the cementoenamel junction (CEJ) and the flap will be positioned 1 mm coronal CEJ. In the opposite quadrant periosteal envelope that does not use relaxing incisions, avoiding any scars, will be performed with the PCR. The clinical parameters (gingival recession height and width, keratinized tissue thickness and width) will be evaluated 2 weeks after basic periodontal therapy and after 6 and 12 months to surgical procedures..
Outside the setting of well-designed prospective clinical studies, the current standard preoperative RT should be a conventionally 1.8-2 Gy fractionated regimen to a total dose of 50 Gy in 5-6 weeks. However, given the vast diversity of sarcoma subtypes, it is also unlikely to assume a uniform therapeutic management to be optimal for all sarcomas alike. Other than 2 Gy fraction sizes and/or 50 Gy total dose series have been investigated in the past and should be further exploited in the future, but the practical implementation in humans is hampered by the rarity of the disease. The current systemic treatment of sarcomas consists of both the older cytotoxic chemotherapies and the newer targeted therapies like tyrosine kinase inhibitors. But it is hard to predict which patients will respond to which specific systemic treatment. This leads to worse prognoses and unnecessary toxicity for sarcoma patients. Despite the fact that the number of sarcoma patients in current studies is too small with a mix of different subtypes, some subtypes show a better response than other subtypes. This platform may form the basis for preclinical translational investigations with radiotherapy and various systemic treatments.
The aim of this study is to evaluate the volume of madibular bone after placement of a xenograft in a fresh extraction socket in human. The surgery protocol is flapless, and the teeth are mandibular premolars or molars leaving sockets with 4 walls intact or at least 3 walls intact and the buccal wall at 80% . This study will include 35 patients.