Global variation in anastomosis and end colostomy formation following left-sided colorectal resection

Background End colostomy rates following colorectal resection vary across institutions in high-income settings, being influenced by patient, disease, surgeon and system factors. This study aimed to assess global variation in end colostomy rates after left-sided colorectal resection. Methods This study comprised an analysis of GlobalSurg-1 and -2 international, prospective, observational cohort studies (2014, 2016), including consecutive adult patients undergoing elective or emergency left-sided colorectal resection within discrete 2-week windows. Countries were grouped into high-, middle- and low-income tertiles according to the United Nations Human Development Index (HDI). Factors associated with colostomy formation versus primary anastomosis were explored using a multilevel, multivariable logistic regression model. Results In total, 1635 patients from 242 hospitals in 57 countries undergoing left-sided colorectal resection were included: 113 (6·9 per cent) from low-HDI, 254 (15·5 per cent) from middle-HDI and 1268 (77·6 per cent) from high-HDI countries. There was a higher proportion of patients with perforated disease (57·5, 40·9 and 35·4 per cent; P < 0·001) and subsequent use of end colostomy (52·2, 24·8 and 18·9 per cent; P < 0·001) in low- compared with middle- and high-HDI settings. The association with colostomy use in low-HDI settings persisted (odds ratio (OR) 3·20, 95 per cent c.i. 1·35 to 7·57; P = 0·008) after risk adjustment for malignant disease (OR 2·34, 1·65 to 3·32; P < 0·001), emergency surgery (OR 4·08, 2·73 to 6·10; P < 0·001), time to operation at least 48 h (OR 1·99, 1·28 to 3·09; P = 0·002) and disease perforation (OR 4·00, 2·81 to 5·69; P < 0·001). Conclusion Global differences existed in the proportion of patients receiving end stomas after left-sided colorectal resection based on income, which went beyond case mix alone

Photosynthesis in poor nutrient soils, in compacted soils, and under drought

Plants require the uptake of nutrients (in most cases via roots) and their incorporation into plant organs for growth. In non-woody species, 83% of fresh weight is water, 7% is carbon, 5% is oxygen, with the remaining 5% including hydrogen and such nutrients. In natural ecosystems, availability of nutrients in soils is heterogeneous, and many species often adapt their growth to the amount of nutrients that roots can take up by exploring the available soil volume. In agricultural areas, the lack of some nutrients is frequent. In both cases, plants must also face periods of drought and soil compaction. These environmental stresses are therefore not uncommon in natural ecosystems and crops, and the stressed plants often experience a decrease in photosynthetic CO2 fixation. In this chapter, we review changes observed in photosynthesis in response to nutrient deficiencies, soil compaction, and drought. The current knowledge on photosynthesis in carnivorous plants, as a special case of plant species growing in nutrient poor soils, is also included. Pigment limitations (chlorosis and/or necrosis), stomatal limitations, ultrastructural effects and mesophyll conductance limitations, photochemistry (primary reactions), carboxylation and Calvin-cycle reactions, and carbohydrate metabolism and transport will be discussed. With regard to nutrients, we have focused on the most common nutrition-related stresses in plants, the deficiencies of macro- (nitrogen, phosphorous, and potassium) and micronutrients (iron, manganese, copper, and zinc). Other nutrient deficiencies (or toxicities, both in the cases of essential nutrient excess or heavy metals) are not reviewed here. For other nutrient deficiencies and toxicities, and the role of the above-mentioned, and other nutrients (such as calcium and magnesium) in gas exchange, and as intracellular signal transducers, enzyme activators, and structure and function stabilizers of biological membranes, readers are referred to papers published elsewhere (Marschner H, Mineral nutrition of higher plants. Academic, London, 1995; Cakmak I, Kirkby EA, Physiol Plant 133:692–704, 2008; Morales F, Warren CR, Photosynthetic responses to nutrient deprivation and toxicities. In: Flexas J, Loreto F, Medrano H (eds) Terrestrial photosynthesis in a changing environment: a molecular, physiological and ecological approach. Cambridge University Press, Cambridge, pp 312–330, 2012; Hochmal AK, Schulze S, Trompelt K, Hippler M, Biochim Biophys Acta 1847:993–1003, 2015).This study was supported by the Spanish Ministry of Economy and Competitiveness (MINECO; projects AGL2012-31988, AGL2013-42175-R, AGL2016-75226-R, and AGL2016-79868-R, co-financed with FEDER), the Aragón Government (Group A03), grant LO1204 (Sustainable development of research in the Centre of the Region Haná) from the National Program of Sustainability I, and by the Czech Science Foundation Agency (project 16-07366Y). FM wishes to thank JC Martínez for his help with some periodic bibliographic searches.Peer reviewe