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Extracellular vesicles (EVs) are future promising therapeutics, but their instability in vivo after administration remains an important barrier to their further development. Many groups evaluated EV surface modification strategies to add a targeting group with the aim of controlling EV biodistribution. Conversely, fewer groups focused on their stabilization to obtain "stealth" allogenic EVs. Modulating their stabilization and biodistribution is an essential prerequisite for their development as nano-therapeutics. Here, we explored polyoxazolines with lipid anchors association to the EV membrane (POxylation as an alternative to PEGylation) to stabilize EVs in plasma and control their biodistribution, while preserving their native properties. We found that this modification maintained and seemed to potentiate the immunomodulatory properties of EVs derived from mesenchymal stem/stromal cells (MSC). Using a radiolabeling protocol to track EVs at a therapeutically relevant concentration in vivo, we demonstrated that POxylation is a promising option to stabilize EVs in plasma because it increased EV half-life by 6 fold at 6 h post-injection. Moreover, EV accumulation in tumors was higher after POxylation than after PEGylation.
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Aleutian disease (AD) is a devastating infectious disease in American mink (Neogale vison) industry caused by Aleutian mink disease virus (AMDV). Two crucial steps toward controlling infectious diseases in farm animals are: (i) assessment of the infection risk factors to minimize the likelihood of infection and (ii) selection of animals with superior immune responses against pathogens to build tolerant farms. This study aimed to investigate AD risk factors and evaluate a novel "ImmunAD" approach for genetic improvement of AD tolerance. Phenotypic records and pedigree information of 1,366 and 24,633 animals were included in this study. The risk of animal's age, sex, color type, and year of sampling on AMDV infection was assessed using a logistic regression model and counter immune-electrophoresis (CIEP) test results. ImmunAD phenotype was calculated based on AMDVG enzyme-linked immunosorbent assay (ELISA) and CIEP test results, and breeding values for ImmunAD were estimated using an animal model. Animals were classified into high-coordinated (HCIR), average-coordinated (ACIR), and low-coordinated immune responders (LCIR) using ImmunAD's breeding values, and the impact of selection of HCIR on live grade of pelt quality (PQ), harvest weight (HW), and harvest length (HL) breeding values were evaluated. Age of > 1 year, male sex, and year of sampling were identified as significant risk factors of AD (p < 0.05). A moderate-to-high heritability (0.55±0.07) was estimated for ImmunAD, while a higher heritability was observed among the CIEP-positive animals (0.76±0.06). Significantly higher breeding values were observed for PQ and HL among HCIR than those for LCIR and ACIR (p < 0.05). Our findings indicate the critical role of male breeders in AD distribution within mink farms. Regular screening of AD in male breeders before pairing them with females during breeding seasons can help disease control. ImmunAD strategy can be applied to genetic improvement of AD tolerance, with favorable impacts on some growth and production traits. Higher genetic gains can be achieved in populations with higher AD seroprevalences.
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Vírus da Doença Aleutiana do Vison , Doença Aleutiana do Vison , Vison , Animais , Doença Aleutiana do Vison/genética , Vison/genética , Fatores de Risco , Masculino , Feminino , Vírus da Doença Aleutiana do Vison/genética , Vírus da Doença Aleutiana do Vison/imunologia , Fenótipo , CruzamentoRESUMO
An experiment was conducted to identify the factors that cause reduced production of cows fed a diet with high content of corn distillers grains with solubles (DDGS). We hypothesized that the factors could be high sulfur (S) content in DDGS, which may directly (S toxicity) or indirectly (DCAD) cause reduced production. We also hypothesized that high PUFA in DDGS could be another major factor. In a randomized complete block design, 60 lactating cows (15 primiparous and 45 multiparous; average ± SD at the beginning of the trial: milk yield, 44.0 ± 6.9 kg/d; DIM, 123 ± 50; BW, 672 ± 82 kg) were blocked, and cows in each block were randomly assigned to 1 of the following treatments: SBM (4.7% fatty acids [FA], 0.22% S, and 178 mEq/kg DM of DCAD), a diet containing soybean meal as the main protein source; DG, with SBM replacing mainly soybean byproducts and supplemental fat with distillers grains at 30% dietary DM (4.7% FA, 0.44% S, and 42 mEq/kg DM of DCAD); SBM+S, SBM with sodium bisulfate for additional dietary S (4.8% FA, 0.37% S, and 198 mEq/kg DM of DCAD); SBM+CO, SBM with corn oil (4.7% FA, 0.23%, and 165 mEq/kg DM of DCAD); and DG+DCAD, DG with increased DCAD (4.7% FA, 0.40% S, and 330 mEq/kg DM of DCAD). Due to the limited number of tiestalls, blocks 1 to 6 started the experiment first as phase 1, and the rest of the blocks, as phase 2, started the experiment after phase 1. All cows were fed the SBM diet for 10 d as a covariate period followed by the experimental period for 35 d. Data were analyzed using PROC MIXED of SAS (Version 9.4, SAS Institute Inc.); block and phase were random effects; and treatments, repeated week, and interaction were fixed effects. We found an interaction of week by treatment for DMI. Although milk yield did not change, milk fat concentration tended to decrease (2.78% vs. 3.34%) for DG compared with SBM. Dry matter, OM, NDF, and CP digestibilities were lower when cows were fed the DG diet compared with SBM. Additionally, cows fed DG had lower blood concentrations of HCO3-, base excess, and total (t)CO2 compared with SBM. The SBM+S diet did not affect production, nutrient digestibility, or blood parameters compared with SBM. The SBM+CO diet decreased milk fat concentration and yield compared with SBM. The DG+DCAD diet tended to increase milk fat yield and concentration (1.24 vs. 1.47 kg/d; 2.78% vs. 3.37%) and increased ECM (40.9 vs. 45.1 kg/d) compared with DG but did not improve nutrient digestibility. However, blood HCO3-, base excess, and tCO2 were greater for DG+DCAD compared with DG. In conclusion, the indirect role of S-, altering DCAD, along with the high PUFA content in DDGS, appear to be the factors causing reduced production responses to a high DDGS diet. Increasing DCAD to 300 mEq/kg DM in a high DDGS diet can be a feeding strategy to alleviate reduced production responses.
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Ração Animal , Dieta , Lactação , Leite , Zea mays , Animais , Bovinos , Feminino , Dieta/veterinária , Leite/química , Ácidos GraxosRESUMO
Host-microbe dynamics are of increasing interest in marine research due to their role in host health and productivity. Changes in the shell microbiome of American lobsters have been associated with epizootic shell disease, a syndrome that is spreading northwards across the eastern U.S. and Canadian Atlantic coast. This study analyzed differences in alpha and beta diversity, as well as differentially abundant taxa, in the shell-associated bacterial community of apparently healthy lobsters from four lobster fishing areas (LFAs) in Atlantic Canada. Over 180 lobsters from New Brunswick, Nova Scotia and Prince Edward Island (PEI) were sampled during seven sampling events over four sampling months. The bacterial community was identified using novel PacBio long-read sequencing, while alpha and beta diversity parameters were analyzed using linear regression models and weighted UniFrac distances. The bacterial richness, diversity and evenness differed by sampling location, sampling month, and molt stage, but not by lobster sex or size, nor sampling depth. Similarly, based on LFA, sampling month, year and lobster molt stage, the shell microbiome differed in microbial community composition with up to 34 out of 162 taxa differing significantly in abundance between sampling groups. This large-scale microbial survey suggests that the shell microbial diversity of apparently healthy lobsters is influenced by spatial and temporal factors such as geographic location, as well as the length of time the carapace is exposed to the surrounding seawater.
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BACKGROUND: Closing base wedge osteotomy (CBWO) is a common procedure to correct severe bunion deformities with high intermetatarsal angles. There are few data demonstrating the radiographic success of CBWOs. METHODS: We evaluated the radiographic outcomes of a CBWO. The primary aim was to assess the change in elevatus after a CBWO. Secondary aims included measuring the change in hallux abductus (HA) and intermetatarsal angles after the osteotomy. The medical records of 24 consecutive patients across 4 years were reviewed. All of the CBWOs were fixated with either one screw and one Kirschner wire or two screws. We hypothesized that the CBWO would reduce the amount of elevatus present. RESULTS: The mean patient age was 35 years. Average preoperative HA and intermetatarsal angles were 35.2° and 15.7°, respectively. Mean postoperative HA and intermetatarsal angles at last radiographic follow-up were 13.3° and 6.1°, respectively. The change in HA and intermetatarsal angles was 21.9° and 9.6°, respectively. All of the patients achieved clinical union. Mean radiographic follow-up was 6 months; median radiographic follow-up was 5 months. The mean preoperative elevatus measurement was 3.5 mm; the mean postoperative elevatus measurement was 2.0 mm (difference, -1.6 mm; P = .0282), indicating that the osteotomy plantarflexed the first metatarsal. Three patients had radiographic evidence of postoperative elevatus; they were asymptomatic at the last clinical follow-up. CONCLUSIONS: Although clinical concern persists for the development of postoperative elevatus with CBWO, this case series showed plantarflexion of the CBWO. The CBWO is a powerful yet stable procedure for severe bunion deformities and should be viewed as a viable alternative to the Lapidus procedure.
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Joanete , Ossos do Metatarso , Humanos , Adulto , Estudos Retrospectivos , Osteotomia , Joanete/diagnóstico por imagem , Joanete/cirurgia , Parafusos Ósseos , Ossos do Metatarso/diagnóstico por imagem , Ossos do Metatarso/cirurgiaRESUMO
The objective of the experiment was to determine the effects of supplemental SFA sources, lysophospholipids (LPL), and their interaction on production and nutrient digestibility in lactating dairy cows. The experiment was conducted with 48 cows in a randomized complete block design. Cows were blocked (12 blocks total) by parity and days in milk and randomly assigned to 4 dietary treatments in each block (2 × 2 factorial arrangement), i.e., 2 sources of fat supplements, C16:0 (PA)- or C18:0 (SA)-enriched fat, and with or without LPL. The experiment was conducted for 6 wk to measure daily dry matter intake, milk yield, and weekly milk composition. During the last week of the experiment, spot fecal and urine samples were collected to determine total-tract nutrient digestibility. Milk samples in the last week were also collected to analyze the milk fatty acid (FA) profile. All data were analyzed using the MIXED procedure of SAS, where block was used as a random effect and FA, LPL, and the interaction of FA by LPL were used as fixed effects. Week and interactions of week by FA or LPL were included for production measures. Different sources of SFA did not affect dry matter intake and milk yield. However, the PA treatment increased (39.7 vs. 36.8 kg) energy-corrected milk compared with SA due to increased milk fat yield. No effect of LPL on production measures was observed. Total-tract digestibilities of dry matter, organic matter, crude protein, and total FA were not different between the PA and SA groups, but PA increased (41.4% vs. 38.8%) neutral detergent fiber digestibility compared with SA. Supplementation of LPL increased (64.7% vs. 60.5%) total FA digestibility, especially 18-carbon FA (74.1% vs. 68.2%). An interaction of SFA by LPL was found for 16-carbon FA digestibility. The PA diet increased the concentration of 16-carbon FA in milk fat and SA increased the concentration of preformed FA (≥18 carbons). Supplementation of LPL decreased the concentration of trans-10 C18:1. No difference in N utilization and excretion among treatments was observed. In conclusion, the PA diet was more effective in improving milk fat yield of lactating cows compared with SA. Supplementation of LPL increased digestibility of total FA, especially 18-carbon FA but did not affect production.
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Dieta , Digestão , Ácidos Graxos , Lactação , Lisofosfolipídeos , Leite , Animais , Bovinos , Feminino , Leite/química , Leite/metabolismo , Dieta/veterinária , Lisofosfolipídeos/metabolismo , Digestão/efeitos dos fármacos , Ração Animal , Suplementos Nutricionais , Nutrientes/metabolismoRESUMO
Aleutian disease (AD) is a multi-systemic infectious disease in American mink (Neogale vison) caused by Aleutian mink disease virus (AMDV). This study aimed to identify candidate regions and genes underlying selection for response against AMDV using whole-genome sequence (WGS) data. Three case-control selection signatures studies were conducted between animals (N = 85) producing high versus low antibody levels against AMDV, grouped by counter immunoelectrophoresis (CIEP) test and two enzyme-linked immunosorbent assays (ELISA). Within each study, selection signals were detected using fixation index (FST) and nucleotide diversity (θπ ratios), and validated by cross-population extended haplotype homozygosity (XP-EHH) test. Within- and between-studies overlapping results were then evaluated. Within-studies overlapping results indicated novel candidate genes related to immune and cellular responses (e.g., TAP2, RAB32), respiratory system function (e.g., SPEF2, R3HCC1L), and reproduction system function (e.g., HSF2, CFAP206) in other species. Between-studies overlapping results identified three large segments under strong selection pressure, including two on chromosome 1 (chr1:88,770-98,281 kb and chr1:114,133-120,473) and one on chromosome 6 (chr6:37,953-44,279 kb). Within regions with strong signals, we found novel candidate genes involved in immune and cellular responses (e.g., homologous MHC class II genes, ITPR3, VPS52) in other species. Our study brings new insights into candidate regions and genes controlling AD response.
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Vírus da Doença Aleutiana do Vison , Doença Aleutiana do Vison , Animais , Humanos , Vison/genética , Doença Aleutiana do Vison/genética , Vírus da Doença Aleutiana do Vison/genética , Cromossomos Humanos Par 1 , Cromossomos Humanos Par 6RESUMO
The shell microbial community of lobsters-a key factor in the development of epizootic shell disease (ESD)-is still insufficiently researched in Atlantic Canada and many knowledge gaps remain. This study aimed to establish a baseline description and analysis of the shell microbiome of apparently healthy lobsters from four locations in the region. More than 180 lobster shell swab samples were collected from New Brunswick, Nova Scotia and Prince Edward Island (PEI). PacBio long-read 16S rDNA sequencing and bioinformatic analyses in QIIME2 identified the shell-associated bacteria. The shell microbiome of healthy lobsters consisted mainly of the bacterial classes Gammaproteobacteria, Saprospiria, Verrucomicrobiae, Alphaproteobacteria, Flavobacteriia, Acidimicrobiia and Planctomycetia. The microbial composition differed regionally and seasonally, with some classes showing decreased or increased relative abundances in the PEI samples as well as in the winter and spring samples in Nova Scotia. The core shell microbiome included potentially pathogenic as well as beneficial bacterial taxa, of which some were present only in certain regions. Bacterial taxa that have previously been associated with ESD were present on healthy lobsters in Atlantic Canada, but their frequency differed by location, sampling time, and moult stage. This study indicated that geographical and seasonal factors influenced the shell microbiome of apparently healthy lobsters more than host factors such as sex, size, and moult stage. Our results provide valuable reference microbial data from lobsters in a disease-free state.
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OBJECTIVE: To describe changes in palliative care characteristics, utilisation and outcomes in Victoria during a period of enhanced public health management and a prolonged lockdown due to coronavirus disease 2019. METHODS: A national retrospective cohort study with palliative care service setting comparisons in Victoria and other mainland states was conducted. RESULTS: Analysis of 48 non-Victorian services (n=53,428 patients) and 20 Victorian services (n=31,125 patients) showed that for community services, patient volume, average length of stay, functional dependency and the proportion of admissions in a deteriorating phase increased during the lockdown in Victoria, yet little changed in comparator states. Regarding inpatient services, the management of family/carer problems remained constant in comparator states, yet substantial fluctuations in outcomes in Victoria were observed. CONCLUSIONS: As health systems adapt to changing circumstances during the pandemic, the ability to upscale community services is critical. Addressing the implications of shifting inpatient care to the community needs attention. IMPLICATIONS FOR PUBLIC HEALTH: Our study highlights the need to ensure community care providers are adequately considered within public health management responses. 'Joined up' policy and implementation across care settings are essential, especially as major barriers to infection control and increased utilisation may be evident in the community during the coronavirus disease 2019 pandemic.
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COVID-19 , Serviços de Saúde Comunitária , Cuidados Paliativos , Humanos , Controle de Doenças Transmissíveis , COVID-19/epidemiologia , Saúde Pública , Estudos Retrospectivos , Política de Saúde , PandemiasRESUMO
The microsporidian diversity catalogued so far has resulted in the development of several taxonomic groups, one of which is the Enterocytozoonida - a group of generalist 'ultimate opportunists', which infect many fished and aquacultured animals, as well as a broad suite of host taxa, including humans. In this study, we provide phylogenetic, ultrastructural, developmental, and pathological evidence for the creation of a new genus and species to hold a microsporidian parasite of the Jonah crab, Cancer borealis. Cancer borealis represents a species of commercial interest and has become the target of a recently developed fishery on the USA and Canadian Atlantic coast. This species was found to harbour a microsporidian parasite that develops in the cytoplasm of alpha and beta cells of the hepatopancreas. We retrieved a 937 bp fragment of the parasite SSU region, alongside developmental and ultrastructural data that suggests this species is â¼ 87 % similar to Parahepatospora carcini and develops in a similar manner in direct association with the host cell cytoplasm. The mature spores are ovoid in shape and measure 1.48 ± 0.15 µm (SD) in length and 1.00 ± 0.11 µm (SD) in width. Phylogenetically, the new parasite clades in the Enterocytozoonida on the same branch as P. carcini. We provide a new genus and species to hold the parasite: Pseudohepatospora borealis n. gen. n. sp. (Microsporidia: Enterocytozoonida) and explore the likelihood that this species may fit into the Hepatoporidae family.
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Braquiúros , Microsporídios , Neoplasias , Humanos , Animais , Braquiúros/parasitologia , Filogenia , Canadá , Microsporídios/genéticaRESUMO
Despite advancements in the treatment of diabetic patients with "at-risk" limbs, minor and major amputations remain commonplace. The diabetic population is especially prone to surgical complications from lower extremity amputation because of comorbidities such as renal disease, hypertension, hyperlipidemia, microvascular and macrovascular disease, and peripheral neuropathy. Complication occurrence may result in increases in hospital stay duration, unplanned readmission rate, mortality rate, number of operations, and incidence of infection. Skin flap necrosis and wound healing delay secondary to inadequate perfusion of soft tissues continues to result in significant morbidity, mortality, and cost to individuals and the health-care system. Intraoperative indocyanine green fluorescent angiography for the assessment of tissue perfusion may be used to assess tissue perfusion in this patient population to minimize complications associated with amputations. This technology provides real-time functional assessment of the macrovascular and microvascular systems in addition to arterial and venous flow to and from the flap soft tissues. This case study explores the use of indocyanine green fluorescent angiography for the treatment of a diabetic patient with a large dorsal and plantar soft-tissue deficit and need for transmetatarsal amputation with nontraditional rotational flap coverage. The authors theorize that the use of indocyanine green may decrease postoperative complications and cost to the health-care system through fewer readmissions and fewer procedures.
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Verde de Indocianina , Retalhos Cirúrgicos , Amputação Cirúrgica/métodos , Angiografia/métodos , Corantes , Humanos , Complicações Pós-Operatórias/etiologia , Retalhos Cirúrgicos/irrigação sanguíneaRESUMO
BACKGROUND: This retrospective review focuses on peripartum anesthetic management and outcome of a series of five pregnant women with left ventricular noncompaction (LVNC). METHODS: The Mayo Clinic Advanced Cohort Explorer medical database was utilized to identify women diagnosed with LVNC who had been admitted for delivery at the Mayo Clinic in Rochester, Minnesota, between January 2001 and September 2021. Echocardiograms were independently reviewed by two board-certified echocardiographers, and those determined by both to meet the Jenni criteria and/or having compatible findings on magnetic resonance imaging (MRI) were included. Electronic medical records were reviewed for information pertaining to cardiac function, labor, delivery, and postpartum management. RESULTS: We identified 44 patients whose medical record included the term "noncompaction" or "hypertrabeculation" and who had delivered at our institution during the study period. Upon detailed review of the medical records, 36 did not meet criteria for LVNC, and three additional patients did not receive the diagnosis until after delivery, leaving five patients with confirmed LVNC who had undergone six deliveries during the study interval. All five patients had a history of arrhythmias or had developed arrhythmias during pregnancy. One patient underwent emergency cesarean delivery due to sustained ventricular tachycardia requiring three intra-operative cardioversions. CONCLUSIONS: This case series adds new evidence to that already available about pregnancies among women with LVNC. Favorable obstetrical outcomes were achievable when multidisciplinary teams were prepared to manage the maternal and fetal consequences of intrapartum cardiac arrhythmias and hemodynamic instability.
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Anestésicos , Cardiopatias Congênitas , Miocárdio Ventricular não Compactado Isolado , Humanos , Feminino , Gravidez , Miocárdio Ventricular não Compactado Isolado/diagnóstico , Período Periparto , Ventrículos do Coração , EcocardiografiaRESUMO
This study evaluated the effect of the delivery of a commercial essential oil blend containing the phytonutrients star anise, cinnamon, rosemary, and thyme oil (via different routes) on broiler chickens' ileal and ceca microbiota and liver transcriptome compared to an antibiotic growth promoter. Eggs were incubated and allocated into three groups: non-injected, in ovo saline, and in ovo essential oil. On day 18 of incubation, 0.2 mL of essential oil in saline (dilution ratio of 2:1) or saline alone was injected into the amnion. At hatch, chicks were assigned to post-hatch treatment combinations: (A) a negative control (corn-wheat-soybean diet), (B) in-feed antibiotics, (C) in-water essential oil (250 mL/1000 L of drinking water), (D) in ovo saline, (E) in ovo essential oil, and (F) in ovo essential oil plus in-water essential oil in eight replicate cages (six birds/cage) and raised for 28 days. On days 21 and 28, one and two birds per cage were slaughtered, respectively, to collect gut content and liver tissues for further analysis. Alpha and beta diversity differed significantly between ileal and ceca samples but not between treatment groups. In-feed antibiotic treatment significantly increased the proportion of specific bacteria in the family Lachnospiraceae while reducing the proportion of bacteria in the genus Christensenellaceae in the ceca, compared to other treatments. Sex-controlled differential expression of genes related to cell signaling and tight junctions were recorded. This study provides data that could guide the use of these feed additives and a foundation for further research.
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Extreme rainfall events in the humid-tropical Luquillo Mountains, Puerto Rico export the bulk of suspended sediment and particulate organic carbon. Using 25 years of river carbon and suspended sediment data, which targeted hurricanes and other large rainstorms, we estimated biogenic particulate organic carbon yields of 65 ± 16 tC km-2 yr-1 for the Icacos and 17.7 ± 5.1 tC km-2 yr-1 for the Mameyes rivers. These granitic and volcaniclastic catchments function as substantial atmospheric carbon-dioxide sinks, largely through export of river biogenic particulate organic carbon during extreme rainstorms. Compared to other regions, these high biogenic particulate organic carbon yields are accompanied by lower suspended sediment yields. Accordingly, particulate organic carbon export from these catchments is underpredicted by previous yield relationships, which are derived mainly from catchments with easily erodible sedimentary rocks. Therefore, rivers that drain petrogenic-carbon-poor bedrock require separate accounting to estimate their contributions to the geological carbon cycle.
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Carbono , Rios , Carbono/análise , Ciclo do Carbono , Monitoramento Ambiental , Florestas , Porto RicoRESUMO
Ulceration or reulceration is a common complication following partial or total fifth ray amputations. The primary aim of this study was to evaluate the incidence of reulceration following partial fifth ray amputations. This was a multicenter review of 117 consecutive limbs that underwent partial fifth ray amputations at the University of Pittsburgh Medical Center and Wake Forest Baptist Medical Centers. Procedures were performed at various levels along the fifth metatarsal. Incidence of postoperative ulceration was evaluated on the ipsilateral foot. We hypothesized there would be an association between location of resection and development of reulceration. Seventy-one of 117 patients (60.7%) experienced repeat ulceration following a partial fifth ray amputation. Median follow-up time was 19 months. There was no statistical difference based on location of amputation (proximal, middle, distal, isolated base) with regards to reulceration (p = .166), further amputation (p = .271), transmetatarsal amputation (p = .160), or below knee amputation (p = .769). There was statistical significance in the follow up time between study sites (p = .013), fifth ray amputation reoperation rate between study sites (p = .001), and reulceration rates between study sites (p = .017). Partial fifth ray amputations can be a good initial salvage procedure to clear infection and prolong bipedal ambulatory status. The results of the present study put forward that there is not an association between location of amputations of the fifth ray and development of reulceration, transfer lesions or more proximal amputations.
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Pé Diabético , Amputação Cirúrgica/métodos , Pé Diabético/cirurgia , Pé/cirurgia , Humanos , Incidência , Reoperação , Estudos RetrospectivosRESUMO
An approximate 1:1 sex ratio of American lobsters can be skewed due to environmental factors or fisheries management. Substantial skewness can impact mating behaviour and lower reproduction which could have far-reaching ecological and economic consequences. The aim was to investigate the sex ratio patterns of lobsters in two lobster fishing areas (LFAs) in southwestern Nova Scotia, Canada and identify factors associated with skewed sex ratios. This study analyzed biological data from more than 270,000 lobsters sampled over ten years (2010-2019) by the Fishermen and Scientists Research Society. A mixed effect logistic regression model evaluated the effect of spatial, temporal and environmental factors as well as size on the sex ratio of lobsters. There were significant temporal patterns in sex ratios that differed by LFA. After the effects of sampling month, year and LFA were accounted for, lower bottom temperature and deeper water depth were associated with a higher prevalence of females, especially in larger lobsters. We present the first long term analyses of sex ratio patterns in H. americanus in Atlantic Canada's most commercially important region for this species and provide evidence that these patterns are influenced by environmental factors and fisheries. In view of future climate change scenarios, monitoring the population dynamics of this iconic fishery species is crucial to ensure sustainable fisheries and healthy lobster stocks.
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Ecossistema , Pesqueiros , Nephropidae/fisiologia , Reprodução/fisiologia , Razão de Masculinidade , Comportamento Sexual Animal/fisiologia , Animais , Mudança Climática , Feminino , Modelos Logísticos , Masculino , Nova Escócia , Água do Mar , Frutos do Mar , Temperatura , Fatores de TempoRESUMO
INTRODUCTION: Residual pluripotent stem cells (PSC) within differentiated populations are problematic because of their potential to form tumors. Simple methods to reduce their occurrence are needed. METHODS: Here, we demonstrate that control of the oxygen partial pressure (pO2) to physiological levels typical of the developing embryo, enabled by culture on a highly oxygen permeable substrate, reduces the fraction of PSC within and the tumorigenic potential of differentiated populations. RESULTS: Differentiation and/or extended culture at low pO2 reduced measured pluripotency markers by up to four orders of magnitude for mouse PSCs (mPSCs). Combination with cell sorting increased the reduction to as much as six orders of magnitude. Upon implantation into immunocompromised mice, mPSCs differentiated at low pO2 either did not form tumors or formed tumors at a slower rate than at high pO2. CONCLUSIONS: Low pO2 culture alone or in combination with other methods is a potentially straightforward method that could be applied to future cell therapy protocols to minimize the possibility of tumor formation.
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Chlorpyrifos is an organophosphate that is currently used to reduce arthropod pests for the protection of agricultural crops. Coastal marine ecosystems may be exposed to agricultural pesticides via runoff and pesticide exposure can impact the health and survival of non-target species such as the American lobster (Homarus americanus). In the current study, the gene expression changes of H. americanus stage IV larvae were evaluated to understand the physiological mechanisms affected by exposure to sublethal concentrations of chlorpyrifos. After 48 h chlorpyrifos exposure, surviving lobsters were processed for Illumina RNA sequencing (RNA-seq). Genes of interest that showed significant changes using RNA-seq were verified using reverse transcriptase quantitative polymerase chain reaction (RT-qPCR). Analysis of RNA-seq and the confirmation of gene expression patterns via RT-qPCR found altered expression in genes related to stress response (glutathione peroxidase 3 and heat shock protein 60), hypoxia response (hairy, astakine 2, hemocyanin), moulting (cytochrome P450 307a1 and chitinase), and immunity (astakine 2) pathways. Changes to gene expression were most notable in lobsters exposed to 0.57 µg/L chlorpyrifos.