GCN5 contributes to intracellular lipid accumulation in human primary cardiac stromal cells from patients affected by Arrhythmogenic cardiomyopathy.

Arrhythmogenic cardiomyopathy (ACM) is a genetic disease associated with sudden cardiac death and cardiac fibro-fatty replacement. Over the last years, several works have demonstrated that different epigenetic enzymes can affect not only gene expression changes in cardiac diseases but also cellular metabolism. Specifically, the histone acetyltransferase GCN5 is known to facilitate adipogenesis and modulate cardiac metabolism in heart failure. Our group previously demonstrated that human primary cardiac stromal cells (CStCs) contribute to adipogenesis in the ACM pathology. Thus, this study aims to evaluate the role of GCN5 in ACM intracellular lipid accumulation. To do so, CStCs were obtained from right ventricle biopsies of ACM patients and from samples of healthy cadaveric donors (CTR). GCN5 expression was increased both in ex vivo and in vitro ACM samples compared to CTR. When GCN5 expression was silenced or pharmacologically inhibited by the administration of MB-3, we observed a reduction in lipid accumulation and a mitigation of reactive oxygen species (ROS) production in ACM CStCs. In agreement, transcriptome analysis revealed that the presence of MB-3 modified the expression of pathways related to cellular redox balance. Altogether, our findings suggest that GCN5 inhibition reduces fat accumulation in ACM CStCs, partially by modulating intracellular redox balance pathways.

Differences in Mitochondrial Membrane Potential Identify Distinct Populations of Human Cardiac Mesenchymal Progenitor Cells.

Adult human cardiac mesenchymal progenitor cells (hCmPC) are multipotent resident populations involved in cardiac homeostasis and heart repair. Even if the mechanisms have not yet been fully elucidated, the stem cell differentiation is guided by the mitochondrial metabolism; however, mitochondrial approaches to identify hCmPC with enhanced stemness and/or differentiation capability for cellular therapy are not established. Here we demonstrated that hCmPCs sorted for low and high mitochondrial membrane potential (using a lipophilic cationic dye tetramethylrhodamine methyl ester, TMRM), presented differences in energy metabolism from preferential glycolysis to oxidative rates. TMRM-high cells are highly efficient in terms of oxygen consumption rate, basal and maximal respiration, and spare respiratory capacity compared to TMRM-low cells. TMRM-high cells showed characteristics of pre-committed cells and were associated with higher in vitro differentiation capacity through endothelial, cardiac-like, and, to a lesser extent, adipogenic and chondro/osteogenic cell lineage, when compared with TMRM-low cells. Conversely, TMRM-low showed higher self-renewal potential. To conclude, we identified two hCmPC populations with different metabolic profile, stemness maturity, and differentiation potential. Our findings suggest that metabolic sorting can isolate cells with higher regenerative capacity and/or long-term survival. This metabolism-based strategy to select cells may be broadly applicable to therapies.

The arrhythmogenic cardiomyopathy-specific coding and non-coding transcriptome in human cardiac stromal cells.

BACKGROUND: Arrhythmogenic cardiomyopathy (ACM) is a genetic autosomal disease characterized by abnormal cell-cell adhesion, cardiomyocyte death, progressive fibro-adipose replacement of the myocardium, arrhythmias and sudden death. Several different cell types contribute to the pathogenesis of ACM, including, as recently described, cardiac stromal cells (CStCs). In the present study, we aim to identify ACM-specific expression profiles of human CStCs derived from endomyocardial biopsies of ACM patients and healthy individuals employing TaqMan Low Density Arrays for miRNA expression profiling, and high throughput sequencing for gene expression quantification. RESULTS: We identified 3 miRNAs and 272 genes as significantly differentially expressed at a 5% false discovery rate. Both the differentially expressed genes as well as the target genes of the ACM-specific miRNAs were found to be enriched in cell adhesion-related biological processes. Functional similarity and protein interaction-based network analyses performed on the identified deregulated genes, miRNA targets and known ACM-causative genes revealed clusters of highly related genes involved in cell adhesion, extracellular matrix organization, lipid transport and ephrin receptor signaling. CONCLUSIONS: We determined for the first time the coding and non-coding transcriptome characteristic of ACM cardiac stromal cells, finding evidence for a potential contribution of miRNAs, specifically miR-29b-3p, to ACM pathogenesis or phenotype maintenance.

Homologous cryopreserved amniotic membrane in the repair of myelomeningocele: preliminary experience.

OBJECTIVE: Surgical management of spinal dysraphism often requires the use of dural substitutes. Amniotic membrane (AM) has drawn the interest of clinicians for its valuable concentration of cytokines and factors capable of promoting wound healing, re-epithelialization, inhibiting fibrosis and regulating angiogenesis. These beneficial qualities could make AM an interesting dural substitute for spina bifida repair. In this study, we describe the use of banked homologous AM as a dural substitute for the repair of spinal dysraphism in newborns. Our purpose is to test the mechanical characteristics, as well as the safety and effectiveness of AM in preventing postoperative complications and re-tethering. METHODS: The AM patch was carefully detached from the chorion of donors undergoing caesarean section, rinsed in saline solution, and cryopreserved in liquid nitrogen. Five newborns were treated using AM: three affected by open spinal dysraphism and two by spina bifida occulta. The AM patch was used as a dural substitute with two different positions and purposes: the amnion-side down covering the placode to prevent adhesions or placed extradurally facing the dura to avoid scarring and facilitating the sliding of the dural sac itself under the extradural tissue layers. RESULTS: No adverse events occurred, and the surgical wounds healed without complications. MRI scans taken at 3 and 6 months after surgery showed a satisfying de-tethering of the spinal cord with no obvious evidence of new adherence formation. CONCLUSIONS: We present a multimodal interposition technique using AM as a reconstructive and anti-adhesive tissue for the treatment of open myelomeningocele (MMC) and lipomeningocele (LMC) treatment. In our experience, AM proved its efficacy in restoring the dural sac integrity without complications. We support the use of AM as a promising dural substitute, speculating on how the use of AM could potentially change reconstructive strategies for spinal dysraphism.

Contamination profile in allografts retrieved from multitissue donors: longitudinal analysis.

Microbiological contamination of retrieved tissues has become an issue of key importance and is a critical aspect of allograft safety, especially in the case of multi-tissue donations, which frequently become contaminated during retrieval and handling. We analysed contamination in 11,129 tissues with a longitudinal contamination profile for each individual tissue. Specifically, 10,035 musculoskeletal tissues and 1094 cardiovascular tissues were retrieved from a total of 763 multi-tissue donors, of whom 105 heart-beating organ donors and 658 deceased tissue donors. Of the 1955 tissues found to be contaminated after the first decontamination step, 1401 tissues (72%) were contaminated by the same species as the one(s) isolated at retrieval (Time1) and 554 (28%) by different species. Among the 113 tissues testing positive after the 2nd decontamination (Time3), 36 tissues (32%) were contaminated by the same species detected at Timel while the contaminating species differed from Time1 in 77 tissues (68%). The higher the number of contaminating species per tissue the higher the percentage of tissues in which contamination changed over time compared to Time1. The analysis revealed a 28% incidence of new species in tissues already testing positive after retrieval and of 3.5% of tissues becoming positive after admission to the tissue bank. Of these, coagulase-negative Staphylococcus accounted for over 70% of new contaminations.

Stability analysis of the antibiotic cocktail used by Treviso Tissue Bank Foundation for tissues decontamination.

Although careful donor selection reduces tissue contamination, close microbiological control of harvested allografts remains a key task of tissue banks. To guarantee the safety of human tissues for allograft transplantation, a decontamination regimen must be adopted which, as recommended by European guidelines, is active against the majority of microorganisms isolated in tissues. Antibiotic decontamination methods differ from one tissue bank to another in terms of antimicrobial agents, temperature and length of exposure. After identifying the most effective antibiotics against the bacterial strains most commonly isolated in allografts, Treviso Tissue Bank Foundation demonstrated the efficacy of an antibiotic cocktail for tissue decontamination containing Gentamicin, Vancomycin and Meropenem. The aim of this study was to analyse the degradation kinetics of the three antibiotics according to preparation method and use. The results show that only Meropenem is unstable at + 4 °C, while Gentamicin and Vancomycin are valid for over 10 days. We thus established to add Meropenem before the start of the tissue decontamination phase.

Decellularized aortic conduits: could their cryopreservation affect post-implantation outcomes? A morpho-functional study on porcine homografts.

Decellularized porcine aortic valve conduits (AVCs) implanted in a Vietnamese Pig (VP) experimental animal model were matched against decellularized and then cryopreserved AVCs to assess the effect of cryopreservation on graft hemodynamic performance and propensity to in vivo repopulation by host's cells. VPs (n = 12) underwent right ventricular outflow tract substitution using AVC allografts and were studied for 15-month follow-up. VPs were randomized into two groups, receiving AVCs treated with decellularization alone (D; n = 6) or decellularization/cryopreservation (DC; n = 6), respectively. Serial echocardiography was carried out to follow up hemodynamic function. All explanted AVCs were processed for light and electron microscopy. No signs of dilatation, progressive stenosis, regurgitation, and macroscopic calcification were echocardiographically observed in both D and DC groups. Explanted D grafts exhibited near-normal features, whereas the presence of calcification, inflammatory infiltrates, and disarray of elastic lamellae occurred in some DC grafts. In the unaltered regions of AVCs from both groups, almost complete re-endothelialization was observed for both valve cusps and aorta walls. In addition, side-by-side repopulation by recipient's fibroblasts, myofibroblasts, and smooth muscle cells was paralleled by ongoing tissue remodeling, as revealed by the ultrastructural identification of typical canals of collagen fibrillogenesis and elastogenesis-related features. Incipient neo-vascularization and re-innervation of medial and adventitial tunicae of grafted aortic walls were also detected for both D and DC groups. Cryopreservation did not affect post-implantation AVC hemodynamic behavior and was topically propensive to cell repopulation and tissue renewal, although graft deterioration including calcification was present in several areas. Thus, these preliminary data provide essential information on feasibility of decellularization and cryopreservation coupling in the perspective of treatment optimization and subsequent clinical trials using similarly treated human allografts as innovative heart valve substitutes.

Evaluation of new antibiotic cocktails against contaminating bacteria found in allograft tissues.

Contamination of retrieved tissues is a major problem for allograft safety. Consequently, tissue banks have implemented decontamination protocols to eliminate microorganisms from tissues. Despite the widespread adoption of these protocols, few comprehensive studies validating such methods have been published. In this manuscript we compare the bactericidal activity of different antibiotic cocktails at different temperatures against a panel of bacterial species frequently isolated in allograft tissues collected at the Treviso Tissue Bank Foundation, a reference organization of the Veneto Region in Italy that was instituted to select, recover, process, store and distribute human tissues. We were able to identify at least two different formulations capable of killing most of the bacteria during prolonged incubation at 4 °C.

Analysis of the effectiveness of Sodium Hypochlorite decontamination of cadaveric human tissues at retrieval.

Bacterial contamination of tissues retrieved from cadaveric donors is a common feature worldwide, and every tissue bank, albeit using different methods, conducts decontamination to guarantee safe tissues suitable for clinical use. The effectiveness of the methods used to eradicate pathogens differs. In order to reduce the tissue bioburden at retrieval, we have introduced a new method involving rinsing tissues in a sodium hypochlorite solution. To test its effectiveness we analyzed two comparable groups of tissues: Group A: 1881 tissues, all rinsed with isotonic saline solution after retrieval, and Group B: 1968 tissues immersed in an isotonic saline solution containing sodium hypochlorite (final concentration 0.1 %) for different lengths of time and subsequently rinsed with isotonic saline. The rinsing solution of each tissue was then sampled for microbiological cultures in both groups. The resultant overall contamination rate was 40.5 % for Group A and 6.7 % for Group B, with an 82.8 % difference in the reduction of contamination between the two groups. This was especially the case for commensal skin bacteria in musculoskeletal tissue, which accounted for over half the overall contamination. Our data highlighted that decontamination with sodium hypochlorite was helpful in reducing the bacterial bioburden in tissues retrieved from cadaveric donors.

Cytokine expression and ultrastructural alterations in fresh-frozen, freeze-dried and γ-irradiated human amniotic membranes.

The aim of this work was to compare the effects on human amniotic membrane of freeze-drying and γ-irradiation at doses of 10, 20 and 30 kGy, with freezing. For this purpose, nine cytokines (interleukin 10, platelet-derived growth factor-AA, platelet-derived growth factor-BB, basic fibroblast growth factor, epidermal growth factor, transforming growth factor beta 1, and tissue inhibitors of metalloproteinase-1, -2, and -4) were titrated in 5 different preparations for each of 3 amniotic membranes included in the study. In addition, the extracellular matrix structure of each sample was assessed by transmission electron microscopy. While freeze-drying did not seem to affect the biological structure or cytokine content of the different amniotic membrane samples, γ-irradiation led to a significant decrease in the tissue inhibitors of metalloproteinase-4, basic fibroblast growth factor and epidermal growth factor, and induced structural damage to the epithelium, basement membrane and lamina densa. The higher the irradiation dose the more severe the damage to the amniotic membrane structure. In conclusion, the Authors recommend processing amniotic membrane under sterile conditions to guarantee safety at every step rather than final sterilization with γ-irradiation, thereby avoiding alteration to the biological characteristics of the amniotic membrane.

Amniotic membranes in ophthalmology: long term data on transplantation outcomes.

The use of amniotic membrane (AM) is a widespread clinical practice for eye surgeries and the treatment of an increasing number of ocular surface pathologies. Here we describe the AM collection methods and donor selection criteria adopted by our tissue bank to distribute 5349 amniotic membrane patches over the last 12 years for the treatment of several ocular pathologies. Specific quality control measures are described and the long term results attained using the reported procedure are presented. A case of AM utilized to treat severe ocular ulceration is also described as an example of AM transplantation. Collective data for the total amniotic membrane patches deployed to treat various ocular diseases are discussed and success rates for AM transplantations are reported. An extensive follow-up is illustrated. The results suggest that the procedures and protocols used by the Treviso Tissue Bank Foundation and Veneto Eye Bank Foundation for collection, preservation, distribution and follow-up are of an optimal standard. Accordingly, the authors conclude that the safety and efficiency of the proposed procedure for the therapeutic use of AM to treat various ocular pathologies are reproducible, with additional evidence favoring the use of AM as an alternative to conventional medical treatment for certain ocular conditions.

Effectiveness of fresh frozen and cryopreserved homologue iliac crest grafts used in sinus lifting: a comparative study.

In the last decade, several investigators have reported that autologous and homologous fresh frozen bones (FFB) are effective materials to restore alveolar ridges previous to insert dental implants. Recently we have used cryopreserved homologue grafts (CFFB). Here we reported a retrospective comparative study between implants inserted in FFB and CFFB evaluate their clinical outcome. Patients were treated with a split mouth scheme for bone grafting with FFB and CFFB and spiral family implants (SPI) were inserted in the same surgical time. Several variables (patient, grafts, anatomic site, implant, prosthetic restoration) were investigated. Implant' failure and peri-implant bone resorption were considered as predictor of clinical outcome. A total of 84 SFIs were inserted in 12 patients. Implants were inserted to replace 8 incisors, 4 cuspids, 31 premolars and 41 molars. The mean follow-up was 14 months. Three out of 84 implants was lost (i.e. survival rate SVR = 96.4%) and no differences were detected among the studied variables. Similar result was obtained by analyzing the crestal bone resorption around implant' neck (i.e. success rate). FFB and CFFB have high and comparable survival and success rate. Implants inserted with one step surgical procedure in native (i.e. not grafted) bone, FFB and CFFB have similar clinical outcome.

Homologous amniotic membrane as a dural substitute in decompressive craniectomies.

INTRODUCTION: A dura mater substitute in decompressive craniectomies must protect the brain while providing a dissection plane between the cortex and myocutaneous layer. The human amniotic membrane (AM) has anti-inflammatory, wound healing, and differentiation properties. We tested AM properties as a dural substitute by comparing the outcomes to biological ones. METHODS: We prospectively collected data on 25 patients who randomly underwent decompressive craniectomy with lyophilized AM patches and 25 in which biological substitutes were utilized between 2015 and 2019. The AM was laid with the epithelial side facing the brain because of the anti-adhesive proprieties, while the chorion facing the myocutaneous flap. We collected data on demographics, neurological status, comorbidities, and surgical outcomes. Additionally, we created a score - dura mimicking score- and reviewed postoperative imaging and pathological specimens. RESULTS: The majority (96%) of AM grafts were integrated into native dura. Thirteen patients scored as excellent and 11 good on our "dura mimicking score", showing tissue integration ability but no cerebral cortex adhesion. The histopathological analysis showed that AM had thick plates of dense fibrous tissue with small reactive vessels, reactive fibroblasts, and lymphocytes infiltrate. The AM group's first outcomes were not different from the biological substitute patients but higher integration rate to the dura and less adhesion to the myocutaneous flap in AM patients. CONCLUSIONS: We documented the anti-adhesive, protective, and integrative properties of AM dural substitute patches in patients who underwent decompressive craniectomies, comparing the intraoperative differences and postoperative outcomes to biological dural substitutes.

Oxidized LDL-dependent pathway as new pathogenic trigger in arrhythmogenic cardiomyopathy.

Arrhythmogenic cardiomyopathy (ACM) is hallmarked by ventricular fibro-adipogenic alterations, contributing to cardiac dysfunctions and arrhythmias. Although genetically determined (e.g., PKP2 mutations), ACM phenotypes are highly variable. More data on phenotype modulators, clinical prognosticators, and etiological therapies are awaited. We hypothesized that oxidized low-density lipoprotein (oxLDL)-dependent activation of PPARγ, a recognized effector of ACM adipogenesis, contributes to disease pathogenesis. ACM patients showing high plasma concentration of oxLDL display severe clinical phenotypes in terms of fat infiltration, ventricular dysfunction, and major arrhythmic event risk. In ACM patient-derived cardiac cells, we demonstrated that oxLDLs are major cofactors of adipogenesis. Mechanistically, the increased lipid accumulation is mediated by oxLDL cell internalization through CD36, ultimately resulting in PPARγ upregulation. By boosting oxLDL in a Pkp2 heterozygous knock-out mice through high-fat diet feeding, we confirmed in vivo the oxidized lipid dependency of cardiac adipogenesis and right ventricle systolic impairment, which are counteracted by atorvastatin treatment. The modulatory role of oxidized lipids on ACM adipogenesis, demonstrated at cellular, mouse, and patient levels, represents a novel risk stratification tool and a target for ACM pharmacological strategies.

Lower perfusion pressure during hypothermic cardiopulmonary bypass is associated with decreased cerebral blood flow and impaired memory performance 6 months postoperatively.

OBJECTIVES: We undertook to determine the influence of perfusion pressure during hypothermic cardiopulmonary bypass (CPB) on cerebral blood flow (CBF) and cognitive memory outcome at 6 months postoperatively. METHODS: Nineteen patients who underwent hypothermic nonpulsatile CPB for elective coronary artery bypass (CAB) surgery were evaluated by (133)Xe measurement of the CBF and by the Incidental Memory Assessment for evaluating cognitive memory (IMTscore), both at baseline before the operation (T(1)) and again at 5 to 6 months postoperatively (T(2)). RESULTS: Overall, the mean CBF fell significantly from 39 +/- 5 mL.(100 g)(-1).min(-1) at T(1) to 33 +/- 3 mL.(100 g)(-1).min(-1) at T(2) (P < .001). The decrease in CBF from T(1) to T(2) (DeltaCBF(2-1)) correlated with a significant reduction in the IMTscore from T1 to T2 (DeltaIMTscore(2-1)) (P < .001) and with a mean arterial pressure during CPB (MAPCPB) of <60 mm Hg (P = .05). Cluster analysis of DeltaCBF(2-1) and DeltaIMTscore(2-1) demonstrated that the patients with the greatest decrease in CBF showed the greatest decrease in IMTscore, whereas cluster analysis of DeltaCBF(2-1) and MAPCPB indicated that patients with a perfusion pressure maintained at a mean of <60 mm Hg during CPB were prone to a greater decrease in later postoperative CBF. CONCLUSION: This study demonstrated that a MAPCPB of <60 mm Hg during CPB was associated with a significant decrease in CBF 6 months after CAB surgery and with an associated decrease in memory performance.

Temporomandibular joint, skull base and mandibular ramus functional reconstruction with homologous bank tissue and free flap: a case report with 30 months follow-up.

Big craniofacial resections for highly invasive malignant neoplasm, including skull base and maxillary bones, always represent a difficult chance for the reconstructive surgeon. In these cases it is not easy to restore anatomy and function simultaneously even adopting complex microsurgical techniques. In maxillofacial and oral surgery, simple bone homotransplantation for small bone segments reconstruction has been developing as popular technique and tissue banks offer not only bone segments but also many different tissues including complex body parts. In this paper we present, a case report of a homotransplantation of a complete temporomandibular joint (TMJ) together with a portion of the medial skull base and mandibular ramus folded with an ante-brachial fascio-periosteal free flap as secondary reconstruction after nearly 5 years from the removal of a sarcoma of the TMJ involving the skull base and a follow up of more than 30 months.

Cyclophilin A/EMMPRIN Axis Is Involved in Pro-Fibrotic Processes Associated with Thoracic Aortic Aneurysm of Marfan Syndrome Patients.

: Background: Marfan syndrome (MFS) is a genetic disease, characterized by thoracic aortic aneurysm (TAA), which treatment is to date purely surgical. Understanding of novel molecular targets is mandatory to unveil effective pharmacological approaches. Cyclophilin A (CyPA) and its receptor EMMPRIN are associated with several cardiovascular diseases, including abdominal aortic aneurysm. Here, we envisioned the contribution of CyPA/EMMPRIN axis in MFS-related TAA. METHODS: We obtained thoracic aortic samples from healthy controls (HC) and MFS patients' aortas and then isolated vascular smooth muscle cells (VSMC) from the aortic wall. RESULTS: our findings revealed that MFS aortic tissue samples isolated from the dilated zone of aorta showed higher expression levels of EMMPRIN vs. MFS non-dilated aorta and HC. Interestingly, angiotensin II significantly stimulated CyPA secretion in MFS-derived VSMC (MFS-VSMC). CyPA treatment on MFS-VSMC led to increased levels of EMMPRIN and other MFS-associated pro-fibrotic mediators, such as TGF-ß1 and collagen I. These molecules were downregulated by in vitro treatment with CyPA inhibitor MM284. Our results suggest that CyPA/EMMPRIN axis is involved in MFS-related TAA development, since EMMPRIN is upregulated in the dilated zone of MFS patients' TAA and the inhibition of its ligand, CyPA, downregulated EMMPRIN and MFS-related markers in MFS-VSMC. CONCLUSIONS: these insights suggest both a novel detrimental role for CyPA/EMMPRIN axis and its inhibition as a potential therapeutic strategy for MFS-related TAA treatment.

Use of homologous bone for alveolar crest reconstruction in 483 patients with 5 years' outcomes post implantation.

PURPOSE: The purpose of this study was to evaluate the clinical course of bone reconstruction of the alveolar crest using homologous fresh-frozen bone harvested from deceased donors. METHODS: A retrospective survey was based on the Castelfranco Veneto Hospital database, in which 3264 clinical records with a primary or secondary diagnosis of alveolar atrophy were collected over a 10-year period. A random sample of 483 patients with at least 5 years' follow-up was included in the survey. Patients were contacted by telephone and administered a questionnaire with specific questions to build a significant sample. RESULTS: Of the patients, 449 (93% of the sample) had an uneventful follow-up after surgery and 93.2% received at least one implant, with a mean of 3.4 implants per patient. At the time of the survey, 93% of the patients were wearing a dental prosthesis, 86.9% had not lost any implants, and 6.7% had lost at least one implant, while 6.4% still had implants but presented some clinical problems. Finally, patients were asked to provide an index score (1-10 points) on the therapy as a whole, i.e., bone graft, implants, and prostheses. A score of insufficient (up to 5 points) was given by 5.3% of patients, of sufficient (6 to 7 points) by 6.1%, and of good/very good (over 7) by 88.6%. CONCLUSIONS: Homologous bone for alveolar crest reconstruction can be a valid alternative to autologous grafting if specific tissue limitations are considered when planning therapy. Creeping substitution is partial and slower than in autologous grafts, especially in cases where cortical bone is thick or volume graft is very large. The quality of soft tissue coverage and mucosa lining is also important, possibly due to slower tissue revascularization, so future implants should predictably be positioned primarily within the original host bone.

Fresh-frozen homologous bone in sinus lifting: histological and radiological analysis.

BACKGROUND: The aim of this study was to evaluate radiological and histological characteristics of fresh-frozen homologous bone as grafting material for maxillary sinus floor augmentation. Radiological, histological and clinical evaluations were made. METHODS: Twenty-three patients with a 2 mm to 6 mm alveolar ridge height in the posterior maxilla have been enrolled. Unilateral or bilateral sinus floor augmentations were performed with fresh frozen morcelized homologous bone. Together with implant placement, 7 months after surgery, a bone core was harvested for histological analysis. Radiological measurements were obtained by superimposition of CT scans carried out at the surgery time and six months later. A total of 93 implants were positioned. RESULTS: A mean (±SD) increase in mineralized tissue height of 10.74±2.82 mm was noticed by comparing the CT scans. Histological analysis revealed the presence of newly formed bone in the grafted sites. The follow up period after the prosthetic load ranged from 8 to 31 months. One implant failure occurred. CONCLUSIONS: Fresh frozen homologous bone seems to have a good healing pattern and to be a successful and steady grafting material for the treatment of maxillary ridge atrophy. It might be considered a valid alternative to autologous bone in sinus floor augmentation procedures.

Evaluation of allograft decontamination with two different antibiotic cocktails at the Treviso Tissue Bank Foundation.

Microbiological contamination of retrieved tissues is a critical aspect of allograft safety and tissue banks must continuously implement decontamination procedures to minimize tissue contamination. In this study we compared the decontamination efficacy of a new antibiotic cocktail (cocktail B: BASE medium with Gentamicin, Meropenem and Vancomycin) with the cocktail previously adopted at Treviso Tissue Bank Foundation (FBTV) (cocktail A: RPMI medium with Ceftazidime, Lincomycin, Polymyxin B and Vancomycin). Two decontamination steps were carried out, the first immediately after retrieval, the second after processing. The contamination rate was calculated before processing (Time 1) and cryopreservation (Time 2) for total tissues, musculoskeletal tissues and cardiovascular tissues, and the bacterial species involved were analyzed. Cocktail A was used to decontaminate 3548 tissues, of which 266 were cardiovascular and 3282 musculoskeletal tissues. For cocktail A, total tissue contamination was 18.6% at Time 1 and 0.9% at Time 2, with 15.7% contaminated musculoskeletal tissues at Time 1 and 0.4% at Time 2, respectively, while cardiovascular tissues were 50% contaminated at Time 1 and 6.4% at Time 2. Cocktail B was used to decontaminate 3634 tissues of which 318 were cardiovascular and 3316 musculoskeletal tissues. For cocktail B, total tissue contamination was 8.6% at Time 1 and 0.2% at Time 2, with 7.6% contaminated musculoskeletal tissues at Time 1 and 0.03% at Time 2, respectively. Contamination of cardiovascular tissues was 20.4% at Time 1 and 1.9% at Time 2. Intergroup and intragroup contamination rates decreased statistically significantly (p<0.05). Our results have shown that cocktail B was more effective than cocktail A in killing bacteria in both cardiovascular and musculoskeletal tissues during the two decontamination cycles.