Efectos de estrés abiótico en la producción de lípidos en Chlorella sp. yTetraselmis chuii, importantes para elaboración de biodiesel

Dissertação de mest., Aquacultura e Pescas, Faculdade de Ciências e Tecnologia, Univ. do Algarve, 2011Las microalgas son un recurso potencial para producir biodiesel y obtener compuestos antioxidantes. El aumento en la concentración de lípidos ocurre en la fase exponencial tardía, aunque también puede ser inducida por estrés abiótico. En este trabajo, Chlorella sp. y Tetraselmis chuii, fueron sometidas a incremento en intensidad luminosa, limitación de nitratos y limitación de hierro, en la fase exponencial tardía para verificar el efecto en la productividad lipídica. Los resultados indicaron un aumento significativo de la concentración de lípidos en Chlorella sp., aumentando la intensidad de luz. Los otros tratamientos no tuvieron un efecto significativo en la concentración de lípidos. En T. chuii no hubo diferencias significativas en la concentración de lípidos con diferentes tipos de estrés. El perfil lipídico de ambas especies sometidas a estrés fue analizado, siendo los ácidos grasos palmítico, palmitoleico y eicosapentaenoico los principales en Chlorella sp., y en T. chuii los ácidos palmítico, linoleico y oleico, este último de gran importancia para elaboración de biodiesel. Fue analizada la actividad antioxidante de biomasa microalgal como posible recurso de compuestos bioactivos con actividad neuroprotectora. Los compuestos bioactivos fueron extraídos por el solvente apolar hexano y el solvente polar diclorometano (DCM), en Chlorella sp., y T. chuii. La actividad antioxidante fue determinada a través del ensayo de radicales libres DPPH, siendo en ambas microalgas significativamente diferente la secuestración de radicales libres (RSA) en las concentraciones de 1-5 y 10 mg mL-1, con el extracto hexano y DCM. En ambas especies, una alta RSA tuvo la concentración de 10 mg mL-1 con el extracto hexano y alta RSA en concentraciones de 5 y 10 mg mL-1 con DCM. Se puede concluir que Chlorella sp presenta una mayor concentración de lípidos que T. chuii, aunque ambas especies poseen ácidos grasos ideales para la elaboración de diesel y son promisorias en actividad antioxidante, aunque faltan estudios para identificar la naturaleza de los compuestos

Distribución geográfica y descripción de cuatro especies de cirripedios pelágicos a lo largo de la costa chilena del Pacífico sur este - una aproximación zoogeográfica

The majority of zoogeographic studies along the Chilean Pacific coast have focused on benthic organisms and oceanographic conditions are considered the main factors influencing their distributions. Herein we examined the geographic distribution of pelagic barnacles of the family Lepadidae collected from floating macroalgae at seven sampling areas between 23 and 50° S. Four species were encountered and they are briefly described herein. The most abundant northern species was Lepas anatifera, and it diminished in abundance towards the south (33° S). Moreover, this species was not found in waters with a sea surface temperature (SST) of less than ~18 ºC. Lepas australis, primarily a circumpolar West Wind Drift species, diminished in abundance towards the north (33° S). This species was restricted to waters of < 18 ºC SST. A third species, L. pectinata, was encountered throughout almost the entire study area, but it was most abundant between 29 and 33° S. The fourth species, Dosima fascicularis, was only found at two sampling areas, namely at 27° S and 33° S, and this is the first record of this species from the central coast of Chile. The distributional pattern of the pelagic barnacles found herein corresponds to the three main zoogeographic regions as revealed by the majority of previous studies based on littoral organisms: the northern Peru-Chilean Province, the southern Magellanic Province, and the central Chilean Transition Zone where the two provinces overlap. Even though the present study only considers four species of pelagic barnacles, the results support the hypotheses on the importance of oceanographic conditions (in particular SST) in determining the zoogeographic patterns along the south east Pacific coast of Chile

Early Developmental Stages of Crustacean Decapods Associated with Floating Seaweed in Fiord and Channels from Southern Chile

Durante el crucero "CIMAR 9 Fiordos" realizado en agosto y noviembre de 2003 en los fiordos y canales de la región de Aysén, Chile, se cuantificó la abundancia de macroalgas flotando a la deriva (MFD) y se identificó los estados tempranos de desarrollo de crustáceos decápodos (megalopas y juveniles, ETD) asociados a ellas. Las macroalgas Macrocystis spp. y Durvillaea antarctica fueron las más abundantes. Para ambos meses monitoreados se registraron las mayores abundancias de MFD en la zona norte del área de estudio y en el sector sur del canal Moraleda. Las abundancias de macroalgas fueron sustancialmente más altas en primavera (noviembre) que en invierno (agosto). Del mismo modo, sólo en primavera se encontró ETD asociados a estas macroalgas, pero en abundancias relativamente bajas (máximo de 5 ind. por muestra). Las especies de crustáceos decápodos encontradas en MFD son especies principalmente intermareales. En un estudio sobre MFD, realizado en la misma localidad y durante primavera de 2002 (CIMAR 8 Fiordos), se encontró mayores abundancias de ETD asociados que en el presente estudio. Se concluye que en la área de estudio hay un suplemento relativamente consistente y alto de MFD, pero existe elevada variabilidad inter e intra-anual de la presencia de ETD en estas macroalgas. Por lo tanto, se sugiere examinar con mayor detalle esta asociación para determinar la importancia de MFD en el proceso de reclutamiento de especies de crustáceos decápodos

Estados Tempranos de Desarrollo de Crustáceos Decápodos Asociados a Macroalgas Flotando a la Deriva en Fiordos y Canales del Sur de Chile

Durante el crucero "CIMAR 9 Fiordos" realizado en agosto y noviembre de 2003 en los fiordos y canales de la región de Aysén, Chile, se cuantificó la abundancia de macroalgas flotando a la deriva (MFD) y se identificó los estados tempranos de desarrollo de crustáceos decápodos (megalopas y juveniles, ETD) asociados a ellas. Las macroalgas Macrocystis spp. y Durvillaea antarctica fueron las más abundantes. Para ambos meses monitoreados se registraron las mayores abundancias de MFD en la zona norte del área de estudio y en el sector sur del canal Moraleda. Las abundancias de macroalgas fueron sustancialmente más altas en primavera (noviembre) que en invierno (agosto). Del mismo modo, sólo en primavera se encontró ETD asociados a estas macroalgas, pero en abundancias relativamente bajas (máximo de 5 ind. por muestra). Las especies de crustáceos decápodos encontradas en MFD son especies principalmente intermareales. En un estudio sobre MFD, realizado en la misma localidad y durante primavera de 2002 (CIMAR 8 Fiordos), se encontró mayores abundancias de ETD asociados que en el presente estudio. Se concluye que en la área de estudio hay un suplemento relativamente consistente y alto de MFD, pero existe elevada variabilidad inter e intra-anual de la presencia de ETD en estas macroalgas. Por lo tanto, se sugiere examinar con mayor detalle esta asociación para determinar la importancia de MFD en el proceso de reclutamiento de especies de crustáceos decápodos

Geographic distribution and description of four pelagic barnacles along the south east Pacific coast of Chile - a zoogeographical approximation

The majority of zoogeographic studies along the Chilean Pacific coast have focused on benthic organisms and oceanographic conditions are considered the main factors influencing their distributions. Herein we examined the geographic distribution of pelagic barnacles of the family Lepadidae collected from floating macroalgae at seven sampling areas between 23 and 50° S. Four species were encountered and they are briefly described herein. The most abundant northern species was Lepas anatifera, and it diminished in abundance towards the south (33° S). Moreover, this species was not found in waters with a sea surface temperature (SST) of less than ~18 ºC. Lepas australis, primarily a circumpolar West Wind Drift species, diminished in abundance towards the north (33° S). This species was restricted to waters of < 18 ºC SST. A third species, L. pectinata, was encountered throughout almost the entire study area, but it was most abundant between 29 and 33° S. The fourth species, Dosima fascicularis, was only found at two sampling areas, namely at 27° S and 33° S, and this is the first record of this species from the central coast of Chile. The distributional pattern of the pelagic barnacles found herein corresponds to the three main zoogeographic regions as revealed by the majority of previous studies based on littoral organisms: the northern Peru-Chilean Province, the southern Magellanic Province, and the central Chilean Transition Zone where the two provinces overlap. Even though the present study only considers four species of pelagic barnacles, the results support the hypotheses on the importance of oceanographic conditions (in particular SST) in determining the zoogeographic patterns along the south east Pacific coast of Chile

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

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 <0001) or low (363 of 860, 422 per cent; OR 008, 007 to 010, P <0.001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference -94 (95 per cent c.i. -11.9 to -6.9) per cent; P <0001), but the relationship was reversed in low-HDI countries (+121 (+7.0 to +173) per cent; P <0001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0.60, 0.50 to 073; 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.Peer reviewe

Mortality of emergency abdominal surgery in high-, middle- and low-income countries

Background: Surgical mortality data are collected routinely in high-income countries, yet virtually no low- or middle-income countries have outcome surveillance in place. The aim was prospectively to collect worldwide mortality data following emergency abdominal surgery, comparing findings across countries with a low, middle or high Human Development Index (HDI). Methods: This was a prospective, multicentre, cohort study. Self-selected hospitals performing emergency surgery submitted prespecified data for consecutive patients from at least one 2-week interval during July to December 2014. Postoperative mortality was analysed by hierarchical multivariable logistic regression. Results: Data were obtained for 10 745 patients from 357 centres in 58 countries; 6538 were from high-, 2889 from middle- and 1318 from low-HDI settings. The overall mortality rate was 1⋅6 per cent at 24 h (high 1⋅1 per cent, middle 1⋅9 per cent, low 3⋅4 per cent; P < 0⋅001), increasing to 5⋅4 per cent by 30 days (high 4⋅5 per cent, middle 6⋅0 per cent, low 8⋅6 per cent; P < 0⋅001). Of the 578 patients who died, 404 (69⋅9 per cent) did so between 24 h and 30 days following surgery (high 74⋅2 per cent, middle 68⋅8 per cent, low 60⋅5 per cent). After adjustment, 30-day mortality remained higher in middle-income (odds ratio (OR) 2⋅78, 95 per cent c.i. 1⋅84 to 4⋅20) and low-income (OR 2⋅97, 1⋅84 to 4⋅81) countries. Surgical safety checklist use was less frequent in low- and middle-income countries, but when used was associated with reduced mortality at 30 days. Conclusion: Mortality is three times higher in low- compared with high-HDI countries even when adjusted for prognostic factors. Patient safety factors may have an important role. Registration number: NCT02179112 (http://www.clinicaltrials.gov)

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