132 research outputs found
Intracellular uptake of macromolecules by brain lymphatic endothelial cells during zebrafish embryonic development
The lymphatic system controls fluid homeostasis and the clearance of macromolecules from interstitial compartments. In mammals brain lymphatics were only recently discovered, with significant implications for physiology and disease. We examined zebrafish for the presence of brain lymphatics and found loosely connected endothelial cells with lymphatic molecular signature covering parts of the brain without forming endothelial tubular structures. These brain lymphatic endothelial cells (BLECs) derive from venous endothelium, are distinct from macrophages, and are sensitive to loss of Vegfc. BLECs endocytose macromolecules in a selective manner, which can be blocked by injection of mannose receptor ligands. This first report on brain lymphatic endothelial cells in a vertebrate embryo identifies cells with unique features, including the uptake of macromolecules at a single cell level. Future studies will address whether this represents an uptake mechanism that is conserved in mammals and how these cells affect functions of the embryonic and adult brain
Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study
Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world.
Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231.
Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001).
Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication
Laparoscopy in management of appendicitis in high-, middle-, and low-income countries: a multicenter, prospective, cohort study.
BACKGROUND: Appendicitis is the most common abdominal surgical emergency worldwide. Differences between high- and low-income settings in the availability of laparoscopic appendectomy, alternative management choices, and outcomes are poorly described. The aim was to identify variation in surgical management and outcomes of appendicitis within low-, middle-, and high-Human Development Index (HDI) countries worldwide. METHODS: This is a multicenter, international prospective cohort study. Consecutive sampling of patients undergoing emergency appendectomy over 6 months was conducted. Follow-up lasted 30 days. RESULTS: 4546 patients from 52 countries underwent appendectomy (2499 high-, 1540 middle-, and 507 low-HDI groups). Surgical site infection (SSI) rates were higher in low-HDI (OR 2.57, 95% CI 1.33-4.99, p = 0.005) but not middle-HDI countries (OR 1.38, 95% CI 0.76-2.52, p = 0.291), compared with high-HDI countries after adjustment. A laparoscopic approach was common in high-HDI countries (1693/2499, 67.7%), but infrequent in low-HDI (41/507, 8.1%) and middle-HDI (132/1540, 8.6%) groups. After accounting for case-mix, laparoscopy was still associated with fewer overall complications (OR 0.55, 95% CI 0.42-0.71, p < 0.001) and SSIs (OR 0.22, 95% CI 0.14-0.33, p < 0.001). In propensity-score matched groups within low-/middle-HDI countries, laparoscopy was still associated with fewer overall complications (OR 0.23 95% CI 0.11-0.44) and SSI (OR 0.21 95% CI 0.09-0.45). CONCLUSION: A laparoscopic approach is associated with better outcomes and availability appears to differ by country HDI. Despite the profound clinical, operational, and financial barriers to its widespread introduction, laparoscopy could significantly improve outcomes for patients in low-resource environments. TRIAL REGISTRATION: NCT02179112
Structural and functional conservation of non-lumenized lymphatic endothelial cells in the mammalian leptomeninges
The vertebrate CNS is surrounded by the meninges, a protective barrier comprised of the outer dura mater and the inner leptomeninges, which includes the arachnoid and pial layers. While the dura mater contains lymphatic vessels, no conventional lymphatics have been found within the brain or leptomeninges. However, non-lumenized cells called Brain/Mural Lymphatic Endothelial Cells or Fluorescent Granule Perithelial cells (muLECs/BLECs/FGPs) that share a developmental program and gene expression with peripheral lymphatic vessels have been described in the meninges of zebrafish. Here we identify a structurally and functionally similar cell type in the mammalian leptomeninges that we name Leptomeningeal Lymphatic Endothelial Cells (LLEC). As in zebrafish, LLECs express multiple lymphatic markers, containing very large, spherical inclusions, and develop independently from the meningeal macrophage lineage. Mouse LLECs also internalize macromolecules from the cerebrospinal fluid, including Amyloid-β, the toxic driver of Alzheimer's disease progression. Finally, we identify morphologically similar cells co-expressing LLEC markers in human post-mortem leptomeninges. Given that LLECs share molecular, morphological, and functional characteristics with both lymphatics and macrophages, we propose they represent a novel, evolutionary conserved cell type with potential roles in homeostasis and immune organization of the meninges
Might Heterostyly Underlie Spider Occurrence On Inflorescences? A Case Study Of Palicourea Rigida (rubiaceae), A Common Shrub From Brazilian Cerrado
We carried out a research on the Palicourea rigida (Rubiaceae) inflorescences, a distylous shrub of Brazilian Cerrado. Our objective was to compare the inflorescence architectural complexity and its quality in the two floral morphs and search for any relationship with spider occurrence. In order to assess the quality of inflorescence resources, we quantified the nectar volume and its sugar concentration and the number of fruits and flowers (intact and aborted) for both inflorescence morphs with and without spiders. For the architectural heterogeneity, we quantified floral structures and inflorescence levels of branching. Spider occurrence was higher in longistylous inflorescences than in brevistylous ones. The sampled spiders were classified into the guilds ambushers, jumpers, or orb-weavers. Ambushers, jumpers, and total richness were much higher among longistylous inflorescences. We found no difference between morphs neither in volume or nectar concentration nor in amount of fruits and flowers. However, longistylous inflorescences presented greater architectural heterogeneity than brevistylous ones. Therefore, we suggested that architectural heterogeneity is an important factor underlying the occurrence of cursorial spiders on P. rigida inflorescences, which possibly arose from the relationship between refuge availability and inflorescence architecture. © 2012 Suzana Diniz et al.Foelix, R.F., (1996) Biology of Spiders, , Oxford, UK Oxford University PressRomero, G.Q., Gonzaga, M.O., Santos, A., Japyassú, H.F., Aranhas como agentes de controle biológico em agroecossistemas (2007) Ecologia e Comportamento de Aranhas, pp. 301-315. , Rio de Janeiro, Brazil Editora InterciênciaRomero, G.Q., Souza, J.C., Vasconcellos-Neto, J., Anti-herbivore protection by mutualistic spiders and the role of plant glandular trichomes (2008) Ecology, 89 (11), pp. 3105-3115. , 2-s2.0-63849343303 10.1890/08-0267.1Halaj, J., Ross, D.W., Moldenke, A.R., Importance of habitat structure to the arthropod food-web in Douglas-fir canopies (2000) Oikos, 90 (1), pp. 139-152Nahas, L., Gonzaga, M.O., Del-Claro, K., Emergent Impacts of ant and spiders interactions: Herbivory reduction in a tropical savanna tree (2012) Biotropica, 44 (4), pp. 498-505Teixeira De Souza, A.L., Martins, R.P., Distribution of plant-dwelling spiders: Inflorescences versus vegetative branches (2004) Austral Ecology, 29 (3), pp. 342-349. , DOI 10.1111/j.1442-9993.2004.01371.xDe Souza, A.L.T., Martins, R.P., Foliage density of branches and distribution of plant-dwelling spiders (2005) Biotropica, 37 (3), pp. 416-420. , DOI 10.1111/j.1744-7429.2005.00055.xHatley, C.L., MacMahon, J.A., Spider community organization: Seasonal variation and the role of vegetation architecture (1980) Environmental Entomology, 9, pp. 632-639Evans, T.A., Distribution of social crab spiders in eucalypt forests (1997) Austral Ecology, 22 (1), pp. 107-111. , 2-s2.0-17444414259Balfour, R.A., Rypstra, A.L., The influence of habitat structure on spider density in a no-till soybean agroecosystem (1998) Journal of Arachnology, 26 (2), pp. 221-226. , 2-s2.0-0032219751Raizer, J., Amaral, M.E.C., Does the structural complexity of aquatic macrophytes explain the diversity of associated spider assemblages? (2001) Journal of Arachnology, 29 (2), pp. 227-237. , 2-s2.0-0035538711Scheidler, M., Influence of habitat structure and vegetation architecture on spiders (1990) Zoologischer Anzeiger, 225 (5-6), pp. 333-340. , 2-s2.0-0025527870Denno, R.F., Finke, D.L., Langellotto, G.A., Barbosa, P., Castellanos, I., Direct and indirect effects of vegetation structure and habitat complexity on predator-prey and predator-predator interactions (2005) Ecology of Predator-Prey Interactions, pp. 211-239. , Oxford, UK Oxford University PressNentwig, W., (1993) Spiders of Panama, Flora & Fauna Handbook 12, , Gainesville, Fla, USA Sandhill Crane PressSouza, A.L.T., Gonzaga, M.O., Santos, A., Japyassú, H.F., Influência da estrutura do habitat na distribuição de aranhas (2007) Ecologia e Comportamento de Aranhas, pp. 25-43. , Rio de Janeiro, Brazil Editora InterciênciaChien, S.A., Morse, D.H., The roles of prey and flower quality in the choice of hunting sites by adult male crab spiders Misumena vatia (Araneae, Thomisidae) (1998) Journal of Arachnology, 26 (2), pp. 238-243. , 2-s2.0-0032219748Carlos-Santos, J., Del-Claro, K., Interações entre formigas, herbívoros e nectários extraflorais em Tocoyena formosa (Rubiaceae) em vegetação de cerrado (2001) Revista Brasileira de Zoociências, 3 (1), pp. 77-92Almeida, A.F., Sarmento, F.N.M., (1998) Parque Estadual da Serra de Caldas - Plano de Manejo, , CTE, (Centro Tecnológico de Engenharia Ltda), FEMAGO - Fundação Estadual do Meio Ambiente, Goiânia, BrazilRibeiro, J.F., Walter, B.M.T., Sano, S.M., Almeida, S.P., Fitofisionomias do bioma Cerrado (1998) Cerrado: Ambiente e Flora, pp. 89-166. , EMBRAPA. PlanaltinaRatter, J.A., Bridgewater, S., Ribeiro, J.F., Analysis of the floristic composition of the Brazilian cerrado vegetation III: Comparison of the woody vegetation of 376 areas (2003) Edinburgh Journal of Botany, 60 (1), pp. 57-109. , DOI 10.10M/S0960428603000064MacHado, A.O., (2007) Ções Florais e Heterostilia em Palicourea Rigida (Rubiaceae) Nos Cerrados Do Brasil Central (Master of Science Dissertation) Universidade Federal de Uberlândia, , Uberlândia, BrazilSilva, A.P., (1995) Biologia Reprodutiva e Polinização de Palicourea Rigida H.B.K. (Rubiaceae), , Brasília, Brazil (Master of Science Dissertation), Universidade de BrasíliaShepherd, G.J., (2010) Fitopac 2.1.2.85. Manual Do Usuário, , Campinas, Brazil Departamento de Botânica, Universidade Estadual de CampinasColwell, R.K., http://viceroy.eeb.uconn.edu/estimates/, EstimateS: Statistical estimation of species richness and shared species from samples (Software and User's Guide, Version 7.5, 2005MacArthur, R.H., On the relative abundance of bird species (1957) Proceedings of the National Academy of Sciences of the USA, 43, pp. 293-295Lawton, J.H., Plant architecture and the diversity of phytophagous insects (1983) Annual Review of Entomology, 28, pp. 23-39. , 2-s2.0-0021027010McCoy, E.D., Bell, S.S., Bell, S.S., McCoy, E.D., Mushinsky, R.H., Habitat structure: The evolution and diversifications of a complex topic (1991) Habitat Structure: The Physical Arrangement of Objects in Space, pp. 3-27. , London, UK Chapman & HallFinke, D.L., Denno, R.F., Intraguild predation diminished in complex-structured vegetation: Implications for prey suppression (2002) Ecology, 83 (3), pp. 643-652Finke, D.L., Denno, R.F., Spatial refuge from intraguild predation: Implications for prey suppression and trophic cascades (2006) Oecologia, 149 (2), pp. 265-275. , DOI 10.1007/s00442-006-0443-yHodges, C.M., Optimal foraging in bumblebees: Hunting by expectation (1981) Animal Behaviour, 29 (4), pp. 1166-1171. , 2-s2.0-0000136794Best, L.S., Bierzychudek, P., Pollinator foraging on foxglove (Digitalis purpurea): A test of a new model (1982) Evolution, 36, pp. 70-79Dalby-Ball, G., Meats, A., Effects of fruit abundance within a tree canopy on the behaviour of wild and cultured Queensland fruit flies, Bactrocera tryoni (Froggatt) (Diptera: Tephritidae) (2000) Australian Journal of Entomology, 39 (3), pp. 201-207. , DOI 10.1046/j.1440-6055.2000.00167.xMendonca, L.B., Dos Anjos, L., Flower morphology, nectar features, and hummingbird visitation to Palicourea crocea (Rubiaceae) in the Upper Paraná River floodplain, Brazil (2006) Anais da Academia Brasileira de Ciencias, 78 (1), pp. 45-57. , http://www.scielo.br/pdf/aabc/v78n1/a06v78n1.pdfLouda, S.M., Inflorescence spiders: A cost/benefit analysis for the host plant, Haplopappus venetus Blake ( Asteraceae). (1982) Oecologia, 55 (2), pp. 185-191Morse, D.H., (2007) Predator Upon A Flower, Life History and Fitness in A Crab Spider, , London, UK Harvard University PressDel-Claro, K., Berto, V., Réu, W., Effect of herbivore deterrence by ants on the fruit set of an extrafloral nectary plant, Qualea multiflora (Vochysiaceae) (1996) Journal of Tropical Ecology, 12 (6), pp. 887-892. , 2-s2.0-0030417459Wise, D.H., (1993) Spiders in Ecological Webs, , Cambridge, UK Cambridge University PressBreene, R.G., Dean, D.A., Nyffeler, M., Edwards, G.B., (1993) Biology, Predation Ecology, and Significance of Spiders in Texas Cotton Ecosystems with A Key to the Species, , Texas,Tex, USA Texas Agricultural Experiment StationRiechert, S.E., Lockley, T., Spiders as biological control agents (1984) Annual Review of Entomology, 29, pp. 299-320. , 2-s2.0-002157757
Cab45G trafficking through the insulin secretory pathway is altered in human type 2 diabetes
In type 2 diabetes (T2D), the rate of insulin secretory granule biogenesis can limit insulin secretion from pancreatic β-cells. Using rat insulinoma INS1 β-cells, we show that the soluble Ca2+-binding/trafficking protein, Cab45G, serves as a non-essential chaperone for insulin granule biogenesis. In β-cells, Cab45G is stored within a cis-Golgi reservoir. Cab45G deletion dysregulates Ca2+ homeostasis and leads to secretory abnormality, but insulin granule biogenesis remains intact. Increasing Cab45G biosynthesis leads to anterograde trafficking into insulin granules, stimulating their production. Using human donor islets, we identify increased anterograde Cab45G trafficking in obese humans and humans with T2D, consistent with the heightened demand for granule biogenesis. However, in humans with T2D, Cab45G localizes to a larger proportion of insulin granules compared to those without T2D. Our study provides the first insight into Cab45G function in specialized secretory cells and opens avenues of investigation into mechanisms associated with β-cell compensation and failure
Global economic burden of unmet surgical need for appendicitis
Background: There is a substantial gap in provision of adequate surgical care in many low-and middle-income countries. This study aimed to identify the economic burden of unmet surgical need for the common condition of appendicitis. Methods: Data on the incidence of appendicitis from 170 countries and two different approaches were used to estimate numbers of patients who do not receive surgery: as a fixed proportion of the total unmet surgical need per country (approach 1); and based on country income status (approach 2). Indirect costs with current levels of access and local quality, and those if quality were at the standards of high-income countries, were estimated. A human capital approach was applied, focusing on the economic burden resulting from premature death and absenteeism. Results: Excess mortality was 4185 per 100 000 cases of appendicitis using approach 1 and 3448 per 100 000 using approach 2. The economic burden of continuing current levels of access and local quality was US 73 141 million using approach 2. The economic burden of not providing surgical care to the standards of high-income countries was 75 666 million using approach 2. The largest share of these costs resulted from premature death (97.7 per cent) and lack of access (97.0 per cent) in contrast to lack of quality. Conclusion: For a comparatively non-complex emergency condition such as appendicitis, increasing access to care should be prioritized. Although improving quality of care should not be neglected, increasing provision of care at current standards could reduce societal costs substantially
Pooled analysis of who surgical safety checklist use and mortality after emergency laparotomy
Background: The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods: In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results: Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89⋅6 per cent) compared with that in countries with a middle (753 of 1242, 60⋅6 per cent; odds ratio (OR) 0⋅17, 95 per cent c.i. 0⋅14 to 0⋅21, P < 0⋅001) or low (363 of 860, 42⋅2 percent; OR 0⋅08, 0⋅07 to 0⋅10, P < 0⋅001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference −9⋅4 (95 per cent c.i. −11⋅9 to −6⋅9) per cent; P < 0⋅001), but the relationship was reversed in low-HDI countries (+12⋅1 (+7⋅0 to +17⋅3) per cent; P < 0⋅001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0⋅60, 0⋅50 to 0⋅73; P < 0⋅001). The greatest absolute benefit was seen for emergency surgery in low-and middle-HDI countries. Conclusion: Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries
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