Approaches in biotechnological applications of natural polymers

Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)

Evolution of the use of corticosteroids for the treatment of hospitalised COVID-19 patients in Spain between March and November 2020: SEMI-COVID national registry

Objectives: Since the results of the RECOVERY trial, WHO recommendations about the use of corticosteroids (CTs) in COVID-19 have changed. The aim of the study is to analyse the evolutive use of CTs in Spain during the pandemic to assess the potential influence of new recommendations. Material and methods: A retrospective, descriptive, and observational study was conducted on adults hospitalised due to COVID-19 in Spain who were included in the SEMI-COVID- 19 Registry from March to November 2020. Results: CTs were used in 6053 (36.21%) of the included patients. The patients were older (mean (SD)) (69.6 (14.6) vs. 66.0 (16.8) years; p < 0.001), with hypertension (57.0% vs. 47.7%; p < 0.001), obesity (26.4% vs. 19.3%; p < 0.0001), and multimorbidity prevalence (20.6% vs. 16.1%; p < 0.001). These patients had higher values (mean (95% CI)) of C-reactive protein (CRP) (86 (32.7-160) vs. 49.3 (16-109) mg/dL; p < 0.001), ferritin (791 (393-1534) vs. 470 (236- 996) µg/dL; p < 0.001), D dimer (750 (430-1400) vs. 617 (345-1180) µg/dL; p < 0.001), and lower Sp02/Fi02 (266 (91.1) vs. 301 (101); p < 0.001). Since June 2020, there was an increment in the use of CTs (March vs. September; p < 0.001). Overall, 20% did not receive steroids, and 40% received less than 200 mg accumulated prednisone equivalent dose (APED). Severe patients are treated with higher doses. The mortality benefit was observed in patients with oxygen saturation </=90%. Conclusions: Patients with greater comorbidity, severity, and inflammatory markers were those treated with CTs. In severe patients, there is a trend towards the use of higher doses. The mortality benefit was observed in patients with oxygen saturation </=90%

Experience with continuous levodopa enteral infusion (Duodopa®)in patients with advanced Parkinson's disease in a secondary level hospital

Introduction: Continuous levodopa delivery by enteral infusion (Duodopa®) is an alternative to deep brain stimulation and subcutaneous apomorphine to control motor fluctuations and dyskinesias in advanced Parkinson's disease (PD). We report our experience with Duodopa® therapy in 11 patients with advanced PD. Methods: We retrospectively assessed clinical and quality of life changes in all patients with PD with severe motor fluctuations and dyskinesias who started continuous daily levodopa duodenal infusion through percutaneous endoscopic gastrostomy from September 2006 (Duodopa® was approved for advanced PD treatment in Spain at that date) until April 2010 at the A. Marcide Hospital of Spain. Results: Nine patients received Duodopa® [62.7±10.6 (44–74) years, 63.6% male)]. Pre- Duodopa® clinical characteristics of patients were: disease duration 14.5±8.9 (3–34) years, oral levodopa dose 918.2±277.7 (450–1300) mg/day, and Hoehn and Yahr staging 3.7±0.5 (3–4). Nine patients are still receiving Duodopa®. Patients improved motor fluctuations (72.7% significant improvement), dyskinesia (55.5% significant improvement), daily off-time (90.9%) and daily duration dyskinesia (66.6%) after total infusion time of 170.5 months (3–31). The improvement in Parkinson's Disease Quality of Life Questionnaire-39 (PDQ-39) and Schwab&England Capacity for Daily Living Scale were 38.5±19.8 and 24±12.5 respectively (P<0.05). Equivalent daily dose of levodopa (April 2010) was 1683.4±295.8 (1234–2216) mg/day. Conclusions: Intraduodenal infusion of levodopa offers an important alternative in treating patients with advanced Parkinson disease Resumen: Introducción: La infusión continua de levodopa intraduodenal (Duodopa®) constituye una alternativa a la infusión subcutánea de apomorfina y a la cirugía en pacientes con enfermedad de Parkinson (EP) avanzada. Describimos nuestra experiencia con Duodopa® en pacientes con EP avanzada. Métodos: Realizamos un estudio epidemiológico, observacional, no intervencionista, poblacional, descriptivo, y retrospectivo, en el que se incluyen todos aquellos pacientes con EP avanzada tratados con Duodopa® por parte de la Sección de Neurología del Hospital A. Marcide de Ferrol hasta abril de 2010. Resultados: Once de un total de 12 pacientes seleccionados fueron tratados con Duodopa® [63,6% varones; edad media 62,7 ± 10,6 (44–74) años]. En el momento de ser seleccionados para recibir Duodopa® presentaban: tiempo medio de evolución de enfermedad de 14,5 ± 8,9 (3–34) años, dosis media de levodopa oral de 918,2 ± 277,7 (450–1300) mg/ día, y un estadio de Hoehn y Yahr de 3,7 ± 0,5 (3–4). Nueve pacientes mantienen el tratamiento con Duodopa®. Hubo mejoría en las fluctuaciones motoras (72,7% gran mejoría) y discinesias (55,5% gran mejoría) con reducción del tiempo off/día (90,9%) y tiempo con discinesias/día (66,6%) después de un tiempo total de seguimiento con Duodopa® de 170,5 (3–31) meses. La mejoría en las escalas PDQ-39 y Schwab&England fue de 38,5 ± 19,8 y 24 ± 12,5 puntos respectivamente (p < 0,05). La dosis media equivalente oral de levodopa (abril 2010) fue de 1683,4 ± 295,8 (1234–2216) mg/día. Conclusiones: Duodopa® pudiera ser un tratamiento efectivo, seguro, y bien tolerado alternativo a la cirugía y apomorfina subcutánea en pacientes con EP avanzada adecuadamente seleccionados. Keywords: Dyskinesias, Duodopa, Parkinson's disease, Motor fluctuations, Continuous enteral infusion, Levodopa, Palabras clave: Discinesias, Duodopa, Enfermedad de Parkinson, Fluctuaciones motoras, Infusión continua enteral, Levodop

Experiencia con la infusión continua de levodopa intraduodenal (Duodopa®) en pacientes con enfermedad de Parkinson avanzada en un hospital de segundo nivel asistencial

Resumen: Introducción: La infusión continua de levodopa intraduodenal (Duodopa®) constituye una alternativa a la infusión subcutánea de apomorfina y a la cirugía en pacientes con enfermedad de Parkinson (EP) avanzada. Describimos nuestra experiencia con Duodopa® en pacientes con EP avanzada. Métodos: Realizamos un estudio epidemiológico, observacional, no intervencionista, poblacional, descriptivo, y retrospectivo, en el que se incluyen todos aquellos pacientes con EP avanzada tratados con Duodopa® por parte de la Sección de Neurología del Hospital A. Marcide de Ferrol hasta abril de 2010. Resultados: Once de un total de 12 pacientes seleccionados fueron tratados con Duodopa® [63,6% varones; edad media 62,7 ± 10,6 (44-74) años]. En el momento de ser seleccionados para recibir Duodopa® presentaban: tiempo medio de evolución de enfermedad de 14,5 ± 8,9 (3-34) años, dosis media de levodopa oral de 918,2 ± 277,7 (450-1300) mg/día, y un estadio de Hoehn y Yahr de 3,7 ± 0,5 (3-4). Nueve pacientes mantienen el tratamiento con Duodopa®. Hubo mejoría en las fluctuaciones motoras (72,7% gran mejoría) y discinesias (55,5% gran mejoría) con reducción del tiempo off/día (90,9%) y tiempo con discinesias/día (66,6%) después de un tiempo total de seguimiento con Duodopa® de 170,5 (3-31) meses. La mejoría en las escalas PDQ-39 y Schwab&England fue de 38,5 ± 19,8 y 24 ± 12,5 puntos respectivamente (p < 0,05). La dosis media equivalente oral de levodopa (abril 2010) fue de 1683,4 ± 295,8 (1234-2216) mg/día. Conclusiones: Duodopa® pudiera ser un tratamiento efectivo, seguro, y bien tolerado alternativo a la cirugía y apomorfina subcutánea en pacientes con EP avanzada adecuadamente seleccionados. Abstract: Introduction: Continuous levodopa delivery by enteral infusion (Duodopa®) is an alternative to deep brain stimulation and subcutaneous apomorphine to control motor fluctuations and dyskinesias in advanced Parkinson's disease (PD). We report our experience with Duodopa® therapy in 11 patients with advanced PD. Methods: We retrospectively assessed clinical and quality of life changes in all patients with PD with severe motor fluctuations and dyskinesias who started continuous daily levodopa duodenal infusion through percutaneous endoscopic gastrostomy from September 2006 (Duodopa® was approved for advanced PD treatment in Spain at that date) until April 2010 at the A. Marcide Hospital of Spain. Results: Nine patients received Duodopa® [62.7 ± 10.6 (44-74) years, 63.6% male)]. Pre-Duodopa® clinical characteristics of patients were: disease duration 14.5 ± 8.9 (3-34) years, oral levodopa dose 918.2 ± 277.7 (450-1300) mg/day, and Hoehn and Yahr staging 3.7 ± 0.5 (3-4). Nine patients are still receiving Duodopa®. Patients improved motor fluctuations (72.7% significant improvement), dyskinesia (55.5% significant improvement), daily off-time (90.9%) and daily duration dyskinesia (66.6%) after total infusion time of 170.5 months (3-31). The improvement in Parkinson's Disease Quality of Life Questionnaire-39 (PDQ-39) and Schwab&England Capacity for Daily Living Scale were 38.5 ± 19.8 and 24 ± 12.5 respectively (P < 0.05). Equivalent daily dose of levodopa (April 2010) was 1683.4 ± 295.8 (1234-2216) mg/day. Conclusions: Intraduodenal infusion of levodopa offers an important alternative in treating patients with advanced Parkinson disease. Palabras clave: Discinesias, Duodopa, Enfermedad de Parkinson, Fluctuaciones motoras, Infusión continua enteral, Levodopa, Keywords: Dyskinesias, Duodopa, Parkinson's disease, Motor fluctuations, Continuous enteral infusion, Levodop

Ecohydrology of riparian forests in the Orinoco River Basin

This paper describes some important ecohydrological interactions within riparian forests in lower Orinoco using the Caura and Mapire rivers in Venezuela. The importance of riparian forests and hydrological seasonality for aquatic faunal ecology and human use patterns are examined using the Caura River. On the other hand, the influence of ecohydrology on the composition, structure and diversity of riparian forests communities was analysed using the Mapire River. By comparing the decomposition processes of the Caura and Mapire floodplains, ecohydrological interactions of biochemical gradients along river confluence zones are discussed

Hydrogeomorphic processes in the lower Orinoco River, Venezuela: implications for the biodiversity of this tropical ecosystem

International audienc

Does malnutrition affect survival in cirrhosis?

A total of 1,053 cirrhotic patients were included in a prospective study to determine whether malnutrition is a risk factor for mortality in cirrhotic patients. Child-Pugh classification as well as clinical and biochemical variables were used to assess the severity of cirrhosis. Nutritional status was evaluated both by anthropometric and clinical measurements. Patients were defined as malnourished when midarm muscle area (MAMA) and/or midarm fat area (MAFA) were below the 5th percentile of an age- and sex-matched population. During follow-up, 419 patients died. The estimated survival rate was 82.7% at 1 year, 65.1% at 3 years, and 50.7% at 5 years. The presence of muscle depletion and/or of a steep reduction in fat deposits was associated with a higher risk of mortality (midarm muscle area, < 5th percentile, relative risk = 1.79; midarm fat area, < 5th percentile, relative risk = 1.35). When patients were stratified according to the Child-Pugh classification, cumulative survival was lower in patients with a reduction in muscle mass in Child-Pugh classes A and B (log rank: P = .027; P = .022, respectively) but not in class C. Conversely, a significant reduction in adipose tissue deposits appeared to have no independent impact on survival in any Child-Pugh class. When examined using a multivariate Cox proportional hazard analysis, age, sex, bilirubin, cholinesterase, ascites, and esophageal varices were selected, whereas the parameters of nutritional status were not. This suggests that malnutrition, while strongly associated with the deterioration of liver function, cannot be considered an independent risk factor for mortality in a general population of cirrhotic patients