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1.
Liver Transpl ; 28(3): 386-396, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34482610

RESUMO

Liver transplantation (LT) for cholangiocarcinoma (CCA) remains limited to a small number of centers. Although the role of neoadjuvant therapy (NAT) has been explored over time, an in-depth analysis of NAT strategies remains limited. Furthermore, controversy exists regarding acceptable tumor size during patient selection for LT. This study explores the impact of era, tumor size, and NAT strategy on LT outcomes for CCA. We conducted a retrospective review of 53 patients with CCA treated with LT from 1985 to 2019; 19 hilar CCA (hCCA) and 30 intrahepatic CCA (iCCA) were included. The relative contributions of varying NAT (neoadjuvant chemotherapy [NAC], neoadjuvant local therapy [NALT], and combined NAC and NALT [NACLT]) as well as the implication of tumor size and era were analyzed. The primary endpoint was overall survival (OS). Compared with the old era (1985-2007), 5-year OS in patients who underwent LT in the recent era (2008-2019) showed a superior trend. The 5-year OS from initial treatment in patients receiving NACLT for hCCA and iCCA were 88% and 100% versus 9% and 41% in patients without it, respectively (P = 0.01 for hCCA; P = 0.02 for iCCA), whereas NAC or NALT alone did not show significant differences in OS versus no NAT (P > 0.05). Although 33 patients had large-size tumors (hCCA ≥ 30 mm, n = 12, or iCCA ≥ 50 mm, n = 21), tumor size had no impact on survival outcomes. Outcomes of LT for CCA seem to have improved over time. Multimodal NAT is associated with improved survival in LT for both iCCA and hCCA regardless of tumor size.


Assuntos
Neoplasias dos Ductos Biliares , Colangiocarcinoma , Transplante de Fígado , Neoplasias dos Ductos Biliares/cirurgia , Ductos Biliares Intra-Hepáticos/patologia , Colangiocarcinoma/cirurgia , Humanos , Transplante de Fígado/efeitos adversos , Terapia Neoadjuvante , Resultado do Tratamento
2.
Vet Surg ; 51(1): 157-162, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34453449

RESUMO

OBJECTIVE: To compare the strength of four constructs used to secure an osteotomy in a Center of Rotation Angulation (CORA)-Based Leveling Osteotomy (CBLO) in an ex vivo model. STUDY DESIGN: Ex vivo study. SAMPLE POPULATION: Thirty-two canine tibiae from 17 skeletally mature cadavers weighing between 18 and 33.2 kg. METHODS: Thirty-two paired tibiae with patella and patellar tendon were collected. Each tibia was randomly allocated to a construct group: plate and pin (Plate), plate with countersink compression screw (HCS), plate with tension band (TB), or plate with HCS and TB (HCSTB). Samples were loaded by distraction until failure. The stiffness, yield load, and ultimate load were compared between each fixation method. RESULTS: No difference in stiffness of the constructs was detected between groups (p = .6937). Yield load for the HCSTB group (1211.06 N) was greater than the TB group (1016.41 N), the HCS group (907.20 N), and the Plate group (787.73 N) (p = .0069). The ultimate load for the HCSTB group (1387.82 N) was greater than the TB group (1076.36 N), HCS group (926.62 N), and the Plate group (774.35 N) (p = .0004). CONCLUSIONS: CBLO fixation augmented with a TB and HCS provided a stronger construct that withstood a greater yield load and ultimate load than either augmentation strategy alone. CLINICAL SIGNIFICANCE: Augmenting a CBLO fixation with a TB and a HCS can provide increased construct strength.


Assuntos
Doenças do Cão , Osteotomia , Animais , Fenômenos Biomecânicos , Placas Ósseas/veterinária , Parafusos Ósseos/veterinária , Cadáver , Cães , Fixação Interna de Fraturas/veterinária , Osteotomia/veterinária , Rotação
3.
Agric Syst ; 191: 103137, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36570634

RESUMO

Context: The COVID-19 pandemic has impacted global food systems. This has led to different strategies by communities, governments, and businesses involved in food systems to mitigate and adapt to the unfolding pandemic. Small Island Developing States are particularly exposed to the conflation of risks from COVID-19 disease, economic downturns, underlying climate vulnerabilities and biosecurity risks. Objective: Our study aimed to identify the food systems vulnerabilities, impacts, and opportunities for supporting resilience and sustainable development in selected Pacific Island countries, Papua New Guinea, and Timor-Leste. The study focused on the impacts from the first six months of the pandemic (February-July 2020), with remote data collection and analysis done between May and July 2020. Methods: We conducted 67 interviews, and triangulated information with desktop and news sources emerging at the time. We present results on the effect on smallholder livelihoods, supply chains, governance, communities and employment. Overall, the major impacts of COVID-19 have been on economies, posing risks to future food security and further hampering progress towards key Sustainable Development Goals. Results and conclusions: We found that unemployment and economic contraction have been the most severe effects to date, with long-term consequences for food value chains and smallholder farmers. Disruptions to tourism, labour migration, and remittances have led to varying socio-economic impacts throughout the region. Vulnerable groups, notably women, urban poor, and youth, have been disproportionately affected by unemployment. Timor-Leste has had some social protection measures, whereas in Pacific Countries these have been varied. The lockdowns and State of Emergency initially influenced the distribution and marketing of food, but local food economies are starting to stabilise. The continued functioning of international food supply chains reduced the risk of food insecurity in high import dependent nations, notably import dependent countries like Tuvalu and Kiribati. Significance: The results have significance for three recovery pathways. The first recovery pathway relates to revisiting value chains in light of restricted travel. The second recovery pathway exists through leveraging the adaptive capacities of communities to stimulate innovative agriculture that also integrates climate adaptation and nutrition. The third recovery pathway relates to addressing the structural challenges that perpetuate inequalities and poverty while finding new ways of implementing inclusive policies and research. Our study presents a set of comparative examples of managing a food system shock that can inform future systems-oriented research and policy for sustainable development.

4.
Environ Sci Policy ; 117: 34-45, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34744509

RESUMO

The frequency and severity of shocks to food systems is accelerating globally, exemplified by the current COVID-19 outbreak. In low- and middle-income countries, the impacts have exacerbated existing food system vulnerabilities and poverty. Governments and donors must respond quickly, but few tools are available that identify interventions to build food system resilience, or emerging opportunities for transformation. In this paper we reflect on the application of a systems-based rapid assessment which we applied across 11 Indo-Pacific countries in May-July 2020. Our approach was shaped by three design parameters: the integration of key informants' perspectives engaged remotely within the countries, applicability to diverse food systems and COVID-19 experiences across the region, and the consideration of food systems as complex systems. For the rapid assessment we adopted an analytical framework proposed by Allen and Prosperi (2016). To include a development lens, we added the analysis of vulnerable groups and their exposure, impacts, recovery potential and resilience, and pro-poor interventions. We concluded that the framework and approach facilitated integration and triangulation of disparate knowledge types and data to identify priority interventions and was sufficiently flexible to be applied across food systems, at both national, sub-national and commodity scales. The step-wise method was simple and enabled structured inquiry and reporting. Although the systems concepts appeared more easily transferrable to key informants in some countries than others, potentially transformational interventions were identified, and also some risks of maladaptation. We present a refined framework that emphasises analysis of political, economic and institutional drivers of exposure and vulnerability, the constraints that they pose for building recovery potential and resilience, and trade-offs amongst winners and losers inherent in proposed interventions.

5.
Glob Chang Biol ; 25(9): 3005-3017, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31127672

RESUMO

Understanding the distribution of biodiversity across the Earth is one of the most challenging questions in biology. Much research has been directed at explaining the species latitudinal pattern showing that communities are richer in tropical areas; however, despite decades of research, a general consensus has not yet emerged. In addition, global biodiversity patterns are being rapidly altered by human activities. Here, we aim to describe large-scale patterns of species richness and diversity in terrestrial vertebrate scavenger (carrion-consuming) assemblages, which provide key ecosystem functions and services. We used a worldwide dataset comprising 43 sites, where vertebrate scavenger assemblages were identified using 2,485 carcasses monitored between 1991 and 2018. First, we evaluated how scavenger richness (number of species) and diversity (Shannon diversity index) varied among seasons (cold vs. warm, wet vs. dry). Then, we studied the potential effects of human impact and a set of macroecological variables related to climatic conditions on the scavenger assemblages. Vertebrate scavenger richness ranged from species-poor to species rich assemblages (4-30 species). Both scavenger richness and diversity also showed some seasonal variation. However, in general, climatic variables did not drive latitudinal patterns, as scavenger richness and diversity were not affected by temperature or rainfall. Rainfall seasonality slightly increased the number of species in the community, but its effect was weak. Instead, the human impact index included in our study was the main predictor of scavenger richness. Scavenger assemblages in highly human-impacted areas sustained the smallest number of scavenger species, suggesting human activity may be overriding other macroecological processes in shaping scavenger communities. Our results highlight the effect of human impact at a global scale. As species-rich assemblages tend to be more functional, we warn about possible reductions in ecosystem functions and the services provided by scavengers in human-dominated landscapes in the Anthropocene.


Assuntos
Biodiversidade , Ecossistema , Animais , Clima , Peixes , Humanos , Vertebrados
6.
BMC Vet Res ; 15(1): 287, 2019 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-31399093

RESUMO

BACKGROUND: Acetabular fractures comprise 12-30% of canine pelvic fractures and require accurate anatomic reduction and rigid stability to ensure proper healing and minimize future osteoarthritis. Many techniques have been used to repair these fractures, with common techniques including veterinary acetabular plates or use of screw/wire/polymethylmethacrylate constructs. String-of-Pearl™ plating systems have also been used clinically but there is a lack of research supporting their use for these fractures. The purpose of this study was to compare fracture reduction accuracy, biomechanical characteristics, and mode of failure between String-of-Pearls™, veterinary acetabular plates, screw/wire/polymethylmethacrylate constructs in a simulated, ex-vivo acetabular fracture model. We hypothesized that the String-of-Pearls™ constructs would have equivalent or greater mechanical properties and reduction compared to the other constructs. RESULTS: The mean craniocaudal acetabular diameter before fixation (mean 25.2 mm; range 20 mm - 30.1 mm) was not significantly different from after fixation (mean 23.9 mm; range 20 mm - 28.3 mm) for any fixation method. Comparison of reduction scores between groups revealed no significant differences. No significant differences were noted for cyclical displacement or stiffness. There was significant difference with superior failure load of String-of-Pearls™ compared to screw/wire/polymethylmethacrylate in the 75th percentile of animal weight (P = 0.0021), and superior failure load of String-of-Pearls™ compared to veterinary acetabular plates in the 50th (P = 0.0232) and 75th percentiles (P = 0.0058). Stiffness of the String-of-Pearls™ construct was significantly greater than the veterinary acetabular plate construct (P = 0.0417). For ultimate load, String-of-Pearls™ constructs were significantly greater than screw/wire/polymethylmethacrylate (P = 0.0331) and veterinary acetabular plates (P = 0.0218). CONCLUSION: Although the ease of application for the String-of-Pearls™ implant was subjectively better than other implants, no significant differences were found in fracture reduction scores. The String-of-Pearls™ constructs were stiffer than veterinary acetabular plates and exhibited greater failure and ultimate loads compared to veterinary acetabular plates and screw/wire/polymethylmethacrylate fixations. The String-of-Pearls™ implant appears to be a suitable fixation choice for simple canine acetabular fractures.


Assuntos
Placas Ósseas , Parafusos Ósseos , Fios Ortopédicos , Cães , Fraturas Ósseas/cirurgia , Polimetil Metacrilato , Animais , Fenômenos Biomecânicos , Cadáver , Feminino , Masculino , Teste de Materiais
7.
Vet Surg ; 48(7): 1318-1329, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31291009

RESUMO

OBJECTIVE: To determine the influence of short-term administration of carprofen on bone healing in dogs. STUDY DESIGN: Randomized controlled experimental study. ANIMALS: Eighteen purpose-bred sexually mature hound dogs. METHODS: Tibial osteotomies were performed, and dogs were divided into three groups: no carprofen (n = 6), 2-week administration of carprofen at 2.2 mg/kg twice daily (n = 6), and 8-week administration of carprofen at 2.2 mg/kg twice daily (n = 5). Bone healing was evaluated radiographically at 4 and 8 weeks postoperatively. Postmortem, fracture healing was assessed via biomechanical testing (three-point bending), histological cartilage:callus ratio, and bone mineral density (BMD) with quantitative computed tomography. RESULTS: No biomechanical difference was detected between dogs that received no carprofen and those that received 2 weeks of carprofen or between those that received 2 weeks vs 8 weeks of carprofen. Stiffness (P = .035) and maximum stress (P = .042) were higher in dogs that received no carprofen than in those that received 8 weeks of carprofen. Radiographic healing did not differ between dogs without carprofen and those with 2-week administration of carprofen (P = .9923). However, tibias of dogs without carprofen and those with 2-week administration of carprofen were more healed compared with those in the 8-week-carprofen group at 4 and 8 weeks after surgery (P = .0011). No treatment effect was detected by cartilage:callus ratio or BMD. CONCLUSION: Long-term administration of carprofen had a negative effect on bone healing compared with short-term or no administration of carprofen. CLINICAL SIGNIFICANCE: Nonsteroidal anti-inflammatory drugs should be used cautiously in dogs at risk for delayed bone healing, and administration should be discontinued beyond the perioperative period in dogs with fractures or osteotomies.


Assuntos
Anti-Inflamatórios não Esteroides/administração & dosagem , Carbazóis/administração & dosagem , Consolidação da Fratura/efeitos dos fármacos , Osteotomia/veterinária , Animais , Anti-Inflamatórios não Esteroides/uso terapêutico , Fenômenos Biomecânicos , Densidade Óssea , Calo Ósseo , Carbazóis/uso terapêutico , Cartilagem , Cães , Esquema de Medicação , Tíbia/cirurgia
8.
HPB (Oxford) ; 21(3): 301-309, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30269948

RESUMO

BACKGROUND: Cirrhosis increases the risk of perioperative mortality in gastrointestinal surgery. Though cirrhosis is sometimes considered a contraindication to pancreatoduodenectomy (PD), few data are available in this patient population. The aim of the present study is to identify predictors of outcome in cirrhotic patients undergoing PD. METHODS: Patients undergoing PD with biopsy-proved cirrhosis were evaluated. Primary endpoints were morbidity and mortality. Child score, MELD score, and radiographic evidence of portal hypertension (pHTN) were assessed for accuracy in preoperative risk stratification. A systematic review of the literature with meta-analysis was also performed to query morbidity and mortality of patients with cirrhosis reported to undergo PD. RESULTS: Between 2005 and 2015, 36 cirrhotic patients underwent PD; three year follow-up was complete. Median Child score was 6 (range 5-10); median MELD score was 9 (range 7-18). Perioperative (90-day) mortality was 6/36. Median survival was 37 months (range 0.2-116). MELD ≥ 10 was associated with increased mortality (4/13 vs. 2/13, p = 0.004). Irrespective of Child or MELD score, those with pHTN had poor outcomes including significantly greater intraoperative blood loss, increased incidence of major complication, and length of stay. Postoperative mortality was significantly higher with pHTN (3/16 vs. 1/13, p = 0.012). CONCLUSION: Pancreatoduodenectomy may be considered in carefully selected cirrhotic patients. MELD ≥ 10 predicts increased risk of postoperative mortality. Specific attention should be afforded to patients with preoperative radiographic evidence of portal hypertension as this group experiences poor outcomes irrespective of MELD or Child score.


Assuntos
Cirrose Hepática/cirurgia , Pancreaticoduodenectomia , Humanos , Cirrose Hepática/mortalidade
9.
Genet Med ; 20(9): 985-994, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29300376

RESUMO

PURPOSE: To evaluate the cost-effectiveness of BRCA testing in women with breast cancer, and cascade testing in family members of BRCA mutation carriers. METHODS: A cost-effectiveness analysis was conducted using a cohort Markov model from a health-payer perspective. The model estimated the long-term benefits and costs of testing women with breast cancer who had at least a 10% pretest BRCA mutation probability, and the cascade testing of first- and second-degree relatives of women who test positive. RESULTS: Compared with no testing, BRCA testing of affected women resulted in an incremental cost per quality-adjusted life-year (QALY) gained of AU$18,900 (incremental cost AU$1,880; incremental QALY gain 0.10) with reductions of 0.04 breast and 0.01 ovarian cancer events. Testing affected women and cascade testing of family members resulted in an incremental cost per QALY gained of AU$9,500 compared with testing affected women only (incremental cost AU$665; incremental QALY gain 0.07) with additional reductions of 0.06 breast and 0.01 ovarian cancer events. CONCLUSION: BRCA testing in women with breast cancer is cost-effective and is associated with reduced risk of cancer and improved survival. Extending testing to cover family members of affected women who test positive improves cost-effectiveness beyond restricting testing to affected women only.


Assuntos
Neoplasias da Mama/diagnóstico , Detecção Precoce de Câncer/métodos , Testes Genéticos/economia , Adulto , Austrália , Proteína BRCA1/genética , Proteína BRCA2/genética , Neoplasias da Mama/economia , Neoplasias da Mama/genética , Análise Custo-Benefício/métodos , Técnicas de Apoio para a Decisão , Feminino , Predisposição Genética para Doença , Testes Genéticos/métodos , Testes Genéticos/tendências , Mutação em Linhagem Germinativa/genética , Custos de Cuidados de Saúde , Humanos , Cadeias de Markov , Pessoa de Meia-Idade , Anos de Vida Ajustados por Qualidade de Vida
10.
Agric Syst ; 165: 344-353, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32287945

RESUMO

Food insecurity persists in many parts of Africa and Asia, despite ongoing agricultural research for development (AR4D) interventions. This is resulting in a growing demand for alternative approaches to designing and evaluating interventions in complex systems. Theory of Change (ToC) is an approach which may be useful because it enables stakeholders to present and test their theories and assumptions about why and how impact may occur, ideally within an environment conducive to iterative reflection and learning. However, ToC is yet to be appropriately mainstreamed into development by donors, researchers and practitioners. We carried out a literature review, triangulated by interviews with 26 experts in African and Asian food security, consisting of researchers, advisors to programs, and donors. Although 17 (65%) of the experts had adopted ToC, their responses and the literature revealed four challenges to mainstreaming: (i) different interpretations of ToC; (ii) incoherence in relationships among the constituent concepts of ToC; (iii) confused relationships between ToC and project "logframes"; and (iv) limitations in necessary skills and commitment for enacting ToC. A case study of the evolution of a ToC in a West African AR4D project over 4 years which exemplified these challenges is presented. Five recommendations arise to assist the mainstreaming of ToC: (i) select a type of ToC suited to the relative complexity of the problem and focal system of interest; (ii) state a theory or hypotheses to be tested as the intervention progresses; (iii) articulate the relationship between the ToC and parallel approaches (e.g. logframe); (iv) accept that a ToC is a process, and (v) allow time and resources for implementers and researchers to develop ToC thinking within projects. Finally, we suggest that communities of practice should be established among AR4D and donor organisations to test, evaluate and improve the contribution that ToCs can make to sustainable food security and agricultural development.

11.
J Surg Res ; 212: 238-245, 2017 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-28550913

RESUMO

BACKGROUND: Nuclease-based genome editing has rapidly sped the creation of new models of human disease. These techniques also hold great promise for the future of clinical xenotransplantation and cell-based therapies for cancer or immunodeficient pathology. However, to fully realize the potential of nuclease editing tools, the efficiency and precision of their application must be optimized. The object of this study was to use nonintegrating selection and nuclease-directed homologous recombination to efficiently control the genetic modification of the porcine genome. METHODS: Clustered randomly integrating spaced palindromic repeats and associated Cas9 protein (CRISPR/Cas9)-directed mutagenesis with a single-guide RNA target was designed to target the alpha-1,3-galactosyltransferase locus (GGTA1) of the porcine genome. A vector expressing a single-guide RNA, Cas9 protein, and green fluorescent protein was used to increase plasmid-delivered mutational efficiency when coupled with fluorescence sorting. Single and double-strand DNA oligonucleotides with a restriction site replacing the start codon were created with variable homology lengths surrounding the mutational event site. Finally, a transgene construct was flanked with 50 base pairs of homology directed immediately 5' to a nuclease cut site. These products were introduced to cells with a constant concentration of CRISPR/cas9 vector. Phenotype-specific mutational efficiency was measured by flow cytometer. Controlled homologous insertion was measured by Sanger sequence, restriction enzyme digest and flow cytometry. RESULTS: Expression of a fluorescence protein on the Cas9 vector functioned as a nonintegrating selection marker. Selection by this marker increased phenotype-silencing mutation rates from 3.5% to 82% (P = 0.0002). Insertion or deletion mutation increased from 11% to 96% (P = 0.0007). Co-transfection with homologous DNA oligonucleotides increased the aggregate phenotype-silencing mutation rates up to 22% and increased biallelic events. Single-strand DNA was twice as efficient as double-strand DNA. Furthermore, nuclease-mediated insertion by homology-directed repair successfully drove locus-specific transgene expression in the porcine genome. CONCLUSIONS: A nonintegrating selection strategy based on fluorescence expression can increase the mutational efficiency of the CRISPR/Cas9 system. The precision of this system can be increased by the addition of a very short homologous template sequence and can serve as a method for locus-specific transgene delivery. Together these strategies may be used to efficiently control mutational events. This system may be used to better use the potential of nuclease-mediated genomic editing.


Assuntos
Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Endonucleases , Galactosiltransferases/genética , Edição de Genes/métodos , Recombinação Homóloga , Mutação , Animais , Linhagem Celular , Suínos
12.
BMC Vet Res ; 13(1): 222, 2017 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-28705189

RESUMO

BACKGROUND: Fracture of the ilium is common orthopedic injury that often requires surgical stabilization in canine patients. Of the various methods of surgical stabilization available, application of a lateral bone plate to the ilium is the most common method of fixation. Many plating options are available, each having its own advantages and disadvantages. The purpose of this study was to evaluate the biomechanical properties of a 3.5 mm String-of-Pearls™ plate and a 3.5 mm dynamic compression plate in a cadaveric canine ilial fracture model. Hemipelves were tested in cantilever bending to failure and construct stiffness, yield load, displacement at yield, ultimate load, and mode of failure were compared. RESULTS: The mean stiffness of dynamic compression plate (116 ± 47 N/mm) and String-of-Pearls™ plate (107 ± 18 N/mm) constructs, mean yield load of dynamic compression plate (793 ± 333 N) and String-of-Pearls™ plate (860 ± 207 N) constructs, mean displacement at yield of dynamic compression plate (8.6 ± 3.0 mm) and String-of-Pearls™ plate (10.2 ± 2.8 mm) constructs, and ultimate load at failure of dynamic compression plate (936 ± 320 N) and String-of-Pearls™ plate (939 ± 191 N) constructs were not significantly different. No differences were found between constructs with respect to mode of failure. CONCLUSIONS: No significant biomechanical differences were found between String-of-Pearls™ plate and dynamic compression plate constructs in this simplified cadaveric canine ilial fracture model.


Assuntos
Placas Ósseas/veterinária , Cães/lesões , Fraturas Ósseas/veterinária , Ílio/lesões , Animais , Fenômenos Biomecânicos , Cães/cirurgia , Fixação Interna de Fraturas/instrumentação , Fixação Interna de Fraturas/veterinária , Fraturas Ósseas/cirurgia , Ílio/cirurgia , Falha de Prótese , Estresse Mecânico
13.
Vet Surg ; 46(1): 59-66, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27805732

RESUMO

OBJECTIVE: To compare the biomechanical strength and histologic features of 3-0 Glycomer™ 631 barbed suture (V-LOC™ 90 Absorbable Wound Closure Device, Covidien, Mansfield, MA) to non-barbed 3-0 Glycomer™ 631 suture (Biosyn™, Covidien) for intradermal skin wound closure in the dog. STUDY DESIGN: Randomized, factorial, in vivo. ANIMALS: Eighteen purpose-bred, mature male, and female hound dogs. METHODS: Eighteen adult hound dogs were randomly assigned to 1 of 3 groups designated by postoperative day of assessment. Six skin incisions were made along the dorsum in the thoracolumbar region of each dog with an equal number (n=3) randomly assigned to closure with barbed or non-barbed suture. Six dogs were euthanatized on postoperative days 3, 10, and 14, respectively. Two additional incisions were made on each dog after euthanasia for baseline data (Day 0). The skin incision specimens were harvested for biomechanical testing and histologic evaluation. RESULTS: Non-barbed closure had significantly higher maximum load at failure (P<.001) and stiffness (P<.001) than barbed closure regardless of day. The average tissue reaction score was significantly higher for barbed closure (P=.008), regardless of day. Suturing time for barbed closures was significantly shorter. There was no significant difference in frequency of complications between closures. CONCLUSION: Barbed Glycomer™ 631 closures had a significantly lower maximum load at failure and stiffness, and higher average tissue reaction scores, but showed no difference in short term outcome for intradermal closure of dorsally located skin incisions in dogs.


Assuntos
Cães/cirurgia , Pele/patologia , Técnicas de Sutura/veterinária , Suturas/veterinária , Cicatrização , Animais , Fenômenos Biomecânicos , Procedimentos Cirúrgicos Dermatológicos/veterinária , Feminino , Masculino , Teste de Materiais
14.
Transgenic Res ; 25(5): 751-9, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27100221

RESUMO

UNLABELLED: The future of solid organ transplantation is challenged by an increasing shortage of available allografts. Xenotransplantation of genetically modified porcine organs offers an answer to this problem. Strategies of genetic modification have 'humanized' the porcine model towards clinical relevance. Most notably, these approaches have aimed at either antigen reduction or human transgene expression. The object of this study was to evaluate the relative effects of both antigen reduction and direct complement regulation on the human-anti-porcine complement dependent cytotoxicity response. Genetically modified animals were created through CRISPR/Cas9-directed mutation and human transgene delivery. Pigs doubly deficient in GGTA1 and CMAH genes were compared to pigs of the same background that expressed a human complement regulatory protein (hCRP). A third animal was made deficient in GGTA1, CMAH and B4GalNT2 gene expression. Cells from these animals were subjected to measures of human antibody binding and antibody-mediated complement-dependent cytotoxicity by flow cytometry. Human IgG and IgM antibody binding was unchanged between the double knockout and the transgenic hCRP double knockout pig. IgG and IgM binding was reduced by 49.1 and 43.2 % respectively by silencing the B4GalNT2 gene. Compared to the double knockout, human anti-porcine cytotoxicity was reduced by 8 % with the addition of a hCRP (p = .032); It was reduced by 21 % with silencing the B4GalNT2 gene (p = .012). CONCLUSIONS: Silencing the GGTA1, CMAH and B4GalNT2 genes in pigs achieved a significant antigen reduction. Changing the porcine carbohydrate profile effectively mediates human antibody-mediated complement dependent cytoxicity.


Assuntos
Proteínas do Sistema Complemento/imunologia , Citotoxicidade Imunológica , Galactosiltransferases/genética , Oxigenases de Função Mista/genética , N-Acetilgalactosaminiltransferases/genética , Animais , Animais Geneticamente Modificados/genética , Animais Geneticamente Modificados/imunologia , Sistemas CRISPR-Cas/genética , Proteínas do Sistema Complemento/biossíntese , Proteínas do Sistema Complemento/genética , Regulação da Expressão Gênica , Humanos , Transplante de Órgãos , Suínos/imunologia , Transplante Heterólogo
15.
Pancreatology ; 16(1): 95-8, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26682506

RESUMO

BACKGROUND: Pancreatic lipomas (PL) are a rare, benign mesenchymal neoplasm. Some patients diagnosed with PL are followed radiographically or referred to a second provider, while others are not followed after incidental diagnosis. In this study we describe 74 cases of intrapancreatic lipomas from a single institution over a 12-year period to elucidate the radiologic and clinical natural history of pancreatic lipoma. METHODS: In the period from January 2001 to December 2013, we selected patients over the age of 18 diagnosed with PL based on Ultrasound, CT, and MR imaging. Clinical data were coupled with review of the radiographic image. These patients were retrospectively followed to establish the significance of PL. RESULTS: PL was identified in 0.012% of all patients undergoing cross-sectional imaging during the studied interval. Lipomas ranged in size at diagnosis from 0.1 cm to 4.8 cm. The majority of patients were asymptomatic at presentation. No patient required intervention or exhibited a change in lipoma diagnosis over a median follow up interval of 41.5 months (range 2-145). 47 patients underwent subsequent imaging with a median of two additional exams (range 2-113) over 31 months (range 1-18). 46/47 (98%) patients with subsequent images showed no discernible growth; 1/47 (2%) had a resolution of the lipoma. CONCLUSIONS: Pancreatic lipomas are rare benign mesenchymal neoplasms that exhibit stable size and morphology. They are overwhelmingly asymptomatic. The natural history of pancreatic lipoma is benign. Short-term interval observation is prudent to prove stability and help differentiate from early liposarcoma. Extensive follow-up is not likely necessary for this benign lesion.


Assuntos
Lipoma/diagnóstico , Pancreatopatias/patologia , Adulto , Humanos , Pancreatopatias/diagnóstico , Estudos Retrospectivos
16.
Xenotransplantation ; 23(2): 106-16, 2016 03.
Artigo em Inglês | MEDLINE | ID: mdl-27106872

RESUMO

BACKGROUND: The Galα(1,3)Gal epitope (α-GAL), created by α-1,3-glycosyltransferase-1 (GGTA1), is a major xenoantigen causing hyperacute rejection in pig-to-primate and pig-to-human xenotransplantation. In response, GGTA1 gene-deleted pigs have been generated. However, it is unclear whether there is a residual small amount of α-Gal epitope expressed in GGTA1(-/-) pigs. Isoglobotrihexosylceramide synthase (iGb3s), another member of the glycosyltransferase family, catalyzes the synthesis of isoglobo-series glycosphingolipids with an α-GAL-terminal disaccharide (iGb3), creating the possibility that iGb3s may be a source of α-GAL epitopes in GGTA1(-/-) animals. The objective of this study was to examine the impact of silencing the iGb3s gene (A3GalT2) on pig-to-primate and pig-to-human immune cross-reactivity by creating and comparing GGTA1(-/-) pigs to GGTA1(-/-) - and A3GalT2(-/-) -double-knockout pigs. METHODS: We used the CRISPR/Cas 9 system to target the GGTA1 and A3GalT2 genes in pigs. Both GGTA1 and A3GalT2 genes are functionally inactive in humans and baboons. CRISPR-treated cells used directly for somatic cell nuclear transfer produced single- and double-gene-knockout piglets in a single pregnancy. Once grown to maturity, the glycosphingolipid profile (including iGb3) was assayed in renal tissue by normal-phase liquid chromatography. In addition, peripheral blood mononuclear cells (PBMCs) were subjected to (i) comparative cross-match cytotoxicity analysis against human and baboon serum and (ii) IB4 staining for α-GAL/iGb3. RESULTS: Silencing of the iGb3s gene significantly modulated the renal glycosphingolipid profile and iGb3 was not detected. Moreover, the human and baboon serum PBMC cytotoxicity and α-GAL/iGb3 staining were unchanged by iGb3s silencing. CONCLUSIONS: Our data suggest that iGb3s is not a contributor to antibody-mediated rejection in pig-to-primate or pig-to-human xenotransplantation. Although iGb3s gene silencing significantly changed the renal glycosphingolipid profile, the effect on Galα3Gal levels, antibody binding, and cytotoxic profiles of baboon and human sera on porcine PBMCs was neutral.


Assuntos
Galactose/metabolismo , Galactosiltransferases/genética , Rejeição de Enxerto/genética , Xenoenxertos/imunologia , Transplante Heterólogo , Doença Aguda , Animais , Animais Geneticamente Modificados , Sistemas CRISPR-Cas/genética , Galactosiltransferases/metabolismo , Técnicas de Inativação de Genes/métodos , Humanos , Leucócitos Mononucleares/imunologia , Papio , Suínos , Transplante Heterólogo/métodos
17.
J Surg Res ; 200(2): 698-706, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26375504

RESUMO

BACKGROUND: Thrombocytopenia may represent a significant challenge to the clinical application of solid-organ xenotransplantation. When studied in a pig-to-primate model, consumptive coagulopathy has challenged renal xenografts. New strategies of genetic manipulation have altered porcine carbohydrate profiles to significantly reduce human antibody binding to pig cells. As this process continues to eliminate immunologic barriers to clinical xenotransplantation, the relationship between human platelets and pig organs must be considered. METHODS: Genetically modified pigs that were created by the CRISPR/Cas9 system with α-1,3-galactosyltransferase (GGTA1)(-/-) or GGTA1(-/-) cytidine monophosphate-N-acetylneuraminic acid hydroxylase(-/-) phenotype, as well as domestic pigs, were used in this study. Autologous porcine platelets were isolated from donor animal blood collection, and human platelets were obtained from a blood bank. Platelets were fluorescently labeled and in a single-pass model, human, or autologous platelets were perfused through porcine organs at a constant concentration and controlled temperature. Platelet uptake was measured by sampling venous output and measuring sample florescence against input florescence. In vitro study of the interaction between human platelets and porcine endothelial cells was accomplished by immunohistochemical stain and confocal microscopy. RESULTS: Differences between human and autologous platelet loss through the porcine kidney were not significant in any genetic background tested (WT P = 0.15, GGTA1(-/-)P = 0.12, GGTA1(-/-) cytidine monophosphate-N-acetylneuraminic acid hydroxylase(-/-)P = 0.25). The unmodified porcine liver consumed human platelets in a single-pass model of platelet perfusion in fewer than 10 min. WT suprahepatic inferior vena cava fluoresce reached a maximum of 76% of input fluoresce within the human platelet cohort and was significantly lower than the autologous platelet control cohort (P = 0.001). Confocal microscopic analysis did not demonstrate a significant association between human platelets and porcine renal endothelial cells compared with porcine liver endothelial positive controls. CONCLUSIONS: Our results suggest that in the absence of immunologic injury, human platelets respond in a variable fashion to organ-specific porcine endothelial surfaces. Human platelets are not removed from circulation by exposure to porcine renal endothelium but are removed by unmodified porcine hepatic endothelium. Kidneys possessing genetic modifications currently relevant to clinical xenotransplantation failed to consume human platelets in an isolated single-pass model. Human platelets did not exhibit significant binding to renal endothelial cells by in vitro assay.


Assuntos
Animais Geneticamente Modificados , Plaquetas/imunologia , Transplante de Rim/métodos , Complicações Pós-Operatórias/prevenção & controle , Sus scrofa/genética , Trombocitopenia/prevenção & controle , Transplante Heterólogo/métodos , Animais , Plaquetas/metabolismo , Células Endoteliais/imunologia , Células Endoteliais/metabolismo , Endotélio/imunologia , Endotélio/metabolismo , Galactosiltransferases/genética , Galactosiltransferases/imunologia , Técnicas de Inativação de Genes , Humanos , Rim/imunologia , Rim/metabolismo , Fígado/imunologia , Fígado/metabolismo , Oxigenases de Função Mista/genética , Oxigenases de Função Mista/imunologia , Distribuição Aleatória , Sus scrofa/imunologia , Suínos , Trombocitopenia/etiologia
18.
Conserv Biol ; 30(4): 816-26, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-26511405

RESUMO

Community-based conservation programs in developing countries are often based on the assumption that heteronomous motivation (e.g., extrinsic incentives such as economic rewards and pressure or coercion to act) will incite local communities to adopt conservation behaviors. However, this may not be as effective or sustainable as autonomous motivations (e.g., an intrinsic desire to act due to inherent enjoyment or self-identification with a behavior and through freedom of choice). We analyzed the comparative effectiveness of heteronomous versus autonomous approaches to community-based conservation programs through a case study of Sumatran orangutan (Pongo abelii) conservation in 3 villages in Indonesia. Each village had a different conservation program design. We surveyed people (n = 240) to determine their motivations for and behavior changes relative to orangutan and orangutan habitat (forest) protection. Heteronomous motivations (e.g., income from tourism) led to greater self-reporting of behavior change toward orangutan protection. However, they did not change self-reported behavior toward forest (i.e., orangutan habitat) protection. The most effective approach to creating self-reported behavior change throughout the community was a combination of autonomous and heteronomous motivations. Individuals who were heteronomously motivated to protect the orangutan were more likely to have changed attitudes than to have changed their self-reported behavior. These findings demonstrate that the current paradigm of motivating communities in developing countries to adopt conservation behaviors primarily through monetary incentives and rewards should consider integrating autonomous motivational techniques that promote the intrinsic values of conservation. Such a combination has a greater potential to achieve sustainable and cost-effective conservation outcomes. Our results highlight the importance of using in-depth sociopsychological analyses to inform the design and implementation of community-based conservation programs.


Assuntos
Conservação dos Recursos Naturais , Motivação , Pongo abelii , Animais , Ecossistema , Humanos , Indonésia , Opinião Pública
19.
HPB (Oxford) ; 18(4): 305-11, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27037198

RESUMO

BACKGROUND: Resectable pancreatic ductal adenocarcinoma continues to carry a poor prognosis. Of the controllable clinical variables known to affect outcome, margin status is paramount. Though the importance of a R0 resection is generally accepted, not all margins are easily managed. The superior mesenteric artery [SMA] in particular is the most challenging to clear. The aim of this study was to systematically review the literature with specific focus on the role of a SMA periadventitial dissection during PD and it's effect on margin status in pancreatic adenocarcinoma. STUDY DESIGN: The MEDLINE, EMBASE and Cochrane databases were searched for abstracts that addressed the effect of margin status on survival and recurrence following pancreaticoduodenectomy [PD]. Quantitative analysis was performed. RESULTS: The overall incidence of a R1 resection ranged from 16% to 79%. The margin that was most often positive following PD was the SMA margin, which was positive in 15-45% of resected specimens. Most studies suggested that a positive margin was associated with decreased survival. No consistent definition of R0 resection was observed. CONCLUSIONS: Margin positivity in resectable pancreatic adenocarcinoma is associated with poor survival. Inability to clear the SMA margin is the most common cause of incomplete resection. More complete and consistently reported data are needed to evaluate the potential effect of periadventitial SMA dissection on margin status, local recurrence, or survival.


Assuntos
Carcinoma Ductal Pancreático/cirurgia , Dissecação/métodos , Artéria Mesentérica Superior/cirurgia , Neoplasias Pancreáticas/cirurgia , Pancreaticoduodenectomia , Carcinoma Ductal Pancreático/mortalidade , Carcinoma Ductal Pancreático/patologia , Intervalo Livre de Doença , Dissecação/efeitos adversos , Dissecação/mortalidade , Humanos , Artéria Mesentérica Superior/patologia , Invasividade Neoplásica , Recidiva Local de Neoplasia , Neoplasia Residual , Neoplasias Pancreáticas/mortalidade , Neoplasias Pancreáticas/patologia , Pancreaticoduodenectomia/efeitos adversos , Pancreaticoduodenectomia/mortalidade , Fatores de Risco , Resultado do Tratamento
20.
Xenotransplantation ; 22(3): 194-202, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25728481

RESUMO

BACKGROUND: Simultaneous inactivation of pig GGTA1 and CMAH genes eliminates carbohydrate xenoantigens recognized by human antibodies. The ß4GalNT2 glycosyltransferase may also synthesize xenoantigens. To further characterize glycan-based species incompatibilities, we examined human and non-human primate antibody binding to cells derived from genetically modified pigs lacking these carbohydrate-modifying genes. METHODS: The Cas9 endonuclease and gRNA were used to create pigs lacking GGTA1, GGTA1/CMAH, or GGTA1/CMAH/ß4GalNT2 genes. Peripheral blood mononuclear cells were isolated from these animals and examined for binding to IgM and IgG from humans, rhesus macaques, and baboons. RESULTS: Cells from GGTA1/CMAH/ß4GalNT2 deficient pigs exhibited reduced human IgM and IgG binding compared to cells lacking both GGTA1 and CMAH. Non-human primate antibody reactivity with cells from the various pigs exhibited a slightly different pattern of reactivity than that seen in humans. Simultaneous inactivation of the GGTA1 and CMAH genes increased non-human primate antibody binding compared to cells lacking either GGTA1 only or to those deficient in GGTA1/CMAH/ß4GalNT2. CONCLUSIONS: Inactivation of the ß4GalNT2 gene reduces human and non-human primate antibody binding resulting in diminished porcine xenoantigenicity. The increased humoral immunity of non-human primates toward GGTA1-/CMAH-deficient cells compared to pigs lacking either GGTA1 or GGTA1/CMAH/ß4GalNT2 highlights the complexities of carbohydrate xenoantigens and suggests potential limitations of the non-human primate model for examining some genetic modifications. The progressive reduction of swine xenoantigens recognized by human immunoglobulin through inactivation of pig GGTA1/CMAH/ß4GalNT2 genes demonstrates that the antibody barrier to xenotransplantation can be minimized by genetic engineering.


Assuntos
Antígenos Heterófilos/imunologia , Galactosiltransferases/genética , Leucócitos Mononucleares/imunologia , Transplante Heterólogo , Animais , Animais Geneticamente Modificados , Antígenos Heterófilos/genética , Rejeição de Enxerto/genética , Rejeição de Enxerto/imunologia , Humanos , Oxigenases de Função Mista/genética , Oxigenases de Função Mista/metabolismo , Ligação Proteica , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Suínos
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