307 research outputs found

    Wild Sea Cucumber Trade in Rural Madagascar : Consequences for Conservation and Human Welfare

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    Overexploitation of fisheries is a challenge to both marine conservation and human welfare. The trade of sea cucumbers is a multi-billion-dollar market, spanning over 70 countries. Global concern over unsustainable sea cucumber trade led to the inclusion of three species in CITES Appendix II, two of which are found in Madagascar (Holothuria fuscogilva and H. nobilis). I used 792 structured interviews (2015–2020) to study the intensity of sea cucumber collection and exportation in rural northeastern Madagascar, where 30% of all (terrestrial and aquatic) native species are threatened with extinction. Wild sea cucumber collection was common and increased tenfold during the study; one in five coastal households caught and sold wild sea cucumbers, of which more than half are threatened species, including CITES II restricted H. nobilis (Endangered) and H. fuscogilva (Vulnerable). Sea cucumber collectors were significantly wealthier and more food secure than other community members. Given both the high collection of threatened and regulated species and high regional food insecurity (58% of households), regulation of threatened species alone may not reduce levels of unsustainable catch

    Bone apposition to titanium implants biocoated with recombinant human bone morphogenetic protein 2 (rhBMP-2). A pilot study in dogs

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    The aim of the present study was to investigate bone formation to recombinant human bone morphogenetic protein-2 (rhBMP-2)-biocoated and rhBMP-2-nonbiocoated titanium implants after implantation in dogs. Implantation of sand-blasted and acid-etched (C), chromosulfuric acid surface-enhanced (CSA), and rhBMP-2-biocoated CSA [BMP-A: noncovalently immobilized rhBMP-2 (596 ng/cm(2)), BMP-B: covalently immobilized rhBMP-2 (819 ng/cm(2))] implants was performed in both the mandible and tibia of dogs. After 4 weeks of healing, the percentage of direct bone to implant contact (BIC) and the induced bone density (BD) at a distance of less than and greater than 1 mm adjacent to each implant was assessed. Histomorphometric analysis of implants inserted in the mandible and tibia revealed that BIC values appeared to be highest in the BMP-B group, followed by BMP-A, CSA, and C. BD as measured at a distance of <1 mm revealed obvious differences between groups: BMP-B>BMP-A>CSA>C. However, no differences between groups were observed at a distance of >1 mm. Within the limits of the present study, it may be concluded that rhBMP-2 immobilized by covalent and noncovalent methods on CSA-treated implant surfaces seemed to be stable and promoted direct bone apposition in a concentration-dependant manner

    Bovine pericardium based non-cross linked collagen matrix for successful root coverage, a clinical study in human

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    Introduction: The aim of this study was to clinically assess the capacity of a novel bovine pericardium based, non-cross linked collagen matrix in root coverage. Methods: 62 gingival recessions of Miller class I or II were treated. The matrix was adapted underneath a coronal repositioned split thickness flap. Clinical values were assessed at baseline and after six months. Results: The mean recession in each patient was 2.2 mm at baseline. 6 Months after surgery 86.7% of the exposed root surfaces were covered. On average 0,3 mm of recession remained. The clinical attachment level changed from 3.5 ± 1.3 mm to 1,8 ( ± 0,7) mm during the observational time period. No statistically significant difference was found in the difference of probing depth. An increase in the width of gingiva was significant. With a baseline value of 1.5 ± 0.9 mm an improvement of 2.4 ± 0.8 mm after six month could be observed. 40 out of 62 recessions were considered a thin biotype at baseline. After 6 months all 62 sites were assessed thick. Conclusions: The results demonstrate the capacity of the bovine pericardium based non-cross linked collagen matrix for successful root coverage. This material was able to enhance gingival thickness and the width of keratinized gingiva. The percentage of root coverage achieved thereby is comparable to existing techniques. This method might contribute to an increase of patient's comfort and an enhanced aesthetical outcome

    A randomized clinical trial evaluating the efficacy of the sandwich bone augmentation technique in increasing buccal bone thickness during implant placement. II. Tomographic, histologic, immunohistochemical, and RNA analyses

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    ObjectivesThis study aimed to evaluate the biologic and structural phenotypes of the bone regenerated via the sandwich bone augmentation (SBA) technique, on buccal implant dehiscence defects.Material and MethodsTwenty‐six patients with one buccal implant dehiscence defect each were randomly assigned to two groups. Both groups received a standardized amount of mineralized cancellous and cortical allogenic bone graft. In the test group, a bovine pericardium membrane was placed over the graft, while no membrane was placed in the control group. After 6 months of healing, a bone core biopsy of the regenerated bone was harvested and processed for histologic, immunohistochemical, mRNA, and micro‐computed tomography (μCT) analyses. Of the 26 bone core biopsies, only six cores from the test group and six cores from the control group were suitable for the analysis.ResultsBone volume (BV) in the test group was maintained, but tissue maturation appeared to be delayed. In contrast, tissue maturation appeared to be completed in the control group, but BV was compromised. Micro‐CT analysis showed that specimens from the control group were more structured and mineralized compared with those from the test group. Histologic analysis showed more residual graft particles scattered in a loose fibrous connective tissue matrix with sparse bone formation in the test group, while the control group showed obvious vital bone formation surrounding the residual graft particles. Positive periostin (POSTN), sclerostin, and runt‐related transcription factor‐2 (RUNX2) immunoreactivities were detected in both the control and test groups. However, tartrate‐resistant acid phosphatase (TRAP) positive was mostly noted in the control group. There were significant differences in POSTN, RUNX2 and VEGF expressions between the test and control groups.ConclusionThese findings indicated that the SBA technique was an effective method in preserving adequate structural volume while promoting new vital bone formation. Use of the collagen barrier membrane has successfully maintained the volumetric dimensions of the ridge but might have slowed down the complete maturation of the outermost layer of the grafted site.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113698/1/clr12481-sup-0001-Checklist.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/113698/2/clr12481.pd

    Polarization of the Effects of Autoimmune and Neurodegenerative Risk Alleles in Leukocytes

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    To extend our understanding of the genetic basis of human immune function and dysfunction, we performed an expression quantitative trait locus (eQTL) study of purified CD4[superscript +] T cells and monocytes, representing adaptive and innate immunity, in a multi-ethnic cohort of 461 healthy individuals. Context-specific cis- and trans-eQTLs were identified, and cross-population mapping allowed, in some cases, putative functional assignment of candidate causal regulatory variants for disease-associated loci. We note an over-representation of T cell–specific eQTLs among susceptibility alleles for autoimmune diseases and of monocyte-specific eQTLs among Alzheimer’s and Parkinson’s disease variants. This polarization implicates specific immune cell types in these diseases and points to the need to identify the cell-autonomous effects of disease susceptibility variants

    In vitro evaluation of various bioabsorbable and nonresorbable barrier membranes for guided tissue regeneration

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    <p>Abstract</p> <p>Background</p> <p>Different types of bioabsorbable and nonresorbable membranes have been widely used for guided tissue regeneration (GTR) with its ultimate goal of regenerating lost periodontal structures. The purpose of the present study was to evaluate the biological effects of various bioabsorbable and nonresorbable membranes in cultures of primary human gingival fibroblasts (HGF), periodontal ligament fibroblasts (PDLF) and human osteoblast-like (HOB) cells <it>in vitro</it>.</p> <p>Methods</p> <p>Three commercially available collagen membranes [TutoDent<sup>® </sup>(TD), Resodont<sup>® </sup>(RD) and BioGide<sup>® </sup>(BG)] as well as three nonresorbable polytetrafluoroethylene (PTFE) membranes [ACE (AC), Cytoplast<sup>® </sup>(CT) and TefGen-FD<sup>® </sup>(TG)] were tested. Cells plated on culture dishes (CD) served as positive controls. The effect of the barrier membranes on HGF, PDLF as well as HOB cells was assessed by the Alamar Blue fluorometric proliferation assay after 1, 2.5, 4, 24 and 48 h time periods. The structural and morphological properties of the membranes were evaluated by scanning electron microscopy (SEM).</p> <p>Results</p> <p>The results showed that of the six barriers tested, TD and RD demonstrated the highest rate of HGF proliferation at both earlier (1 h) and later (48 h) time periods (<it>P </it>< 0.001) compared to all other tested barriers and CD. Similarly, TD, RD and BG had significantly higher numbers of cells at all time periods when compared with the positive control in PDLF culture (<it>P </it>≤ 0.001). In HOB cell culture, the highest rate of cell proliferation was also calculated for TD at all time periods (<it>P </it>< 0.001). SEM observations demonstrated a microporous structure of all collagen membranes, with a compact top surface and a porous bottom surface, whereas the nonresorbable PTFE membranes demonstrated a homogenous structure with a symmetric dense skin layer.</p> <p>Conclusion</p> <p>Results from the present study suggested that GTR membrane materials, per se, may influence cell proliferation in the process of periodontal tissue/bone regeneration. Among the six membranes examined, the bioabsorbable membranes demonstrated to be more suitable to stimulate cellular proliferation compared to nonresorbable PTFE membranes.</p
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