Differences in pain perception, health-related quality of life, disability, mood, and sleep between Brazilian and Spanish people with chronic non-specific low back pain

ABSTRACT Background Cultural and social factors play an important role in the development and persistence of Low Back Pain (LBP). Nevertheless, there are few studies investigating differences in LBP features between countries. Objective To determine differences in pain perception between individuals with LBP living in Brazil and Spain. Method Thirty Spanish individuals and 30 age- and sex-comparable Brazilian individuals with LBP were recruited from the Public Health Services of both countries. The Numerical Pain Rating Scale and the pain rating index (PRI), the number of words chosen (NWC), and the present pain index (PPI) extracted from the McGill Pain Questionnaire were used to assess pain. The Oswestry Disability Index, the Short Form-36, Beck Depression Inventory-II, and Pittsburgh Sleep Quality Index were also applied. Differences between countries and the correlation between demographic and clinical variables in each country were assessed with parametric and the nonparametric tests. Results A significant Country by Gender interaction was found for the PRI total score (P=0.038), but not for intensity of pain, disability, PPI, or NWC, in which Spanish women exhibited greater pain ratio than Spanish men (P=0.014), and no gender differences were identified in Brazilians. The Spanish group showed a consistent pattern of correlations for clinical data. Within Brazilian patients, fewer correlations were found and all of the coefficients were lower than those in the Spanish group. Conclusion The pain perception in patients with LBP is different depending on the country. Within Spanish patients, LBP is considered a more global entity affecting multidimensional contexts.

Differences in pain perception, health-related quality of life, disability, mood, and sleep between Brazilian and Spanish people with chronic non-specific low back pain.

BACKGROUND: Cultural and social factors play an important role in the development and persistence of Low Back Pain (LBP). Nevertheless, there are few studies investigating differences in LBP features between countries. OBJECTIVE: To determine differences in pain perception between individuals with LBP living in Brazil and Spain. METHOD: Thirty Spanish individuals and 30 age- and sex-comparable Brazilian individuals with LBP were recruited from the Public Health Services of both countries. The Numerical Pain Rating Scale and the pain rating index (PRI), the number of words chosen (NWC), and the present pain index (PPI) extracted from the McGill Pain Questionnaire were used to assess pain. The Oswestry Disability Index, the Short Form-36, Beck Depression Inventory-II, and Pittsburgh Sleep Quality Index were also applied. Differences between countries and the correlation between demographic and clinical variables in each country were assessed with parametric and the nonparametric tests. RESULTS: A significant Country by Gender interaction was found for the PRI total score (P=0.038), but not for intensity of pain, disability, PPI, or NWC, in which Spanish women exhibited greater pain ratio than Spanish men (P=0.014), and no gender differences were identified in Brazilians. The Spanish group showed a consistent pattern of correlations for clinical data. Within Brazilian patients, fewer correlations were found and all of the coefficients were lower than those in the Spanish group. CONCLUSION: The pain perception in patients with LBP is different depending on the country. Within Spanish patients, LBP is considered a more global entity affecting multidimensional contexts.

Leaf litter mas loss rates and associated faun of tree species commonly used in neotropical riparian reforestation / Tasas de pérdida de masa de la hojarasca y fauna asociada en especies de árboles comúnmente utilizados en la reforestación de riberas neotropicales

A signature of globalization is the prevalence of exotic trees along reforested urban and rural riparian zones in the Neotropics, but little is known about the instream processing of its leaf litter. In this study, leaf litter breakdown rates were measured during 35 days using mesh bags within a reference headwater stream for seven exotic and three native tree species commonly used in urban and rural reforestation. Artocarpus altilis, Schefflera actinophylla and Terminalia catappa scored the highest mass loss rates (>85 %; mean life: t50.

Una de las señales más evidentes de la globalización es la prevalencia de especies de árboles exóticos a lo largo de las zonas ribereñas urbanas y rurales del Neotrópico, pero poco se sabe sobre el procesamiento de su hojarasca dentro de las quebradas. En este estudio se midieron las tasas de pérdida de masa de la hojarasca usando bolsas de angeo en una quebrada de referencia durante 35 días, para siete especies exóticas y tres nativas comúnmente usadas en la reforestación urbana y rural. Artocarpus altilis, Schefflera actinophylla y Terminalia catappa obtuvieron las mayores tasas de pérdida de masa (>85 %; vida media: t50.

Shredders are abundant and species-rich in tropical continental-island low-order streams: Gorgona Island, Tropical Eastern Pacific, Colombia / Trituradoras son abundantes y ricas en especies en corrientes de bajo orden de islas continentales tropicales: Isla Gorgona, Pacífico Oriental Tropical, Colombia

Macroinvertebrate shredders may have been overlooked in tropical streams due to the geographical bias of early studies, methodological limitations, and the complex influences of local-scale factors. While shredders seem to be scarce in most oceanic island streams, we here test if they are abundant in a continental island. Gut content analyses of benthic macroinvertebrates were used to identify shredding taxa in streams located in different types of forest in Gorgona Island (Tropical Eastern Pacific). General dietary overlap (GO) was quantified and relative biomass, relative frequency and the leaf litter percentage in the guts were used to establish the relative importance of each taxon in the shredding guild. Various indices were used to identify the spatial arrangement (i.e. contagious or random) of each taxon and shredding guild among streams. We identified 31 shredding taxa that were divided into specialist-shredders (14 taxa), generalist-shredders (10), and collector-shredders (7). There was a complete GO (0.75, p<0.001) for the guild. Cockroaches (Epilampra) were the most represented shredders due to the greatest contribution to guild total biomass and to the highest content of leaf litter in their guts. These organisms were more important than shrimps and crabs in terms of abundance and biomass in leaf pack samples. Potimirin shrimps ranked second and Stenochironomus midges ranked third. Among aquatic insects, other secondarily important species were Leptohyphes (Ephemeroptera), Macrelmis, Anchytarsus and Tetraglosa (Coleoptera). Ten taxa exhibited contagious spatial pattern and twenty-one exhibited a random distribution. Resource distribution (i.e., leaf packs) between streams was random too. The guild was contagiously distributed, but this result could be highly influenced by the taxa with contagious distribution. Mean abundance, richness and mean biomass of shredders were not significantly correlated with any of the environmental variables measured. Three factors seemly explain the high richness and abundance of shredders in Gorgona Island: (1) its continental origin, (2) its current proximity to the continent (35 km), and (3) the high diversity and availability of leaf litter and woody debris inputs to the streams. Although crabs, shrimps, aquatic insects and semiaquatic-cockroaches coexisted in Gorgona Island, the latter were the most important leaf litter shredders in terms of biomass. Rev. Biol. Trop. 62 (Suppl. 1): 85-105. Epub 2014 February 01.

Existe la posibilidad de que los macroinvertebrados fragmentadores hayan sido subvalorados en las quebradas tropicales debido al sesgo geográfico de los estudios realizados, a limitaciones metódicas y a la influencia de factores de escala local. A pesar de que los fragmentadores son escasos en las quebradas de islas oceánicas, hipotetizamos que son abundantes en Isla Gorgona. Los análisis de contenidos estomacales de estos organismos se usaron para identificar los taxones fragmentadores colectados en quebradas con diferentes tipos de bosque. Se cuantificaron el índice general de sobreposición dietaria (GO por su siglas en inglés), y el índice de valor de importancia de cada taxón en el gremio (con base en biomasa relativa, frecuencia relativa y proporción de tejido vegetal en los contenidos estomacales). El arreglo espacial de cada taxón y el del gremio entre quebradas (i.e., contagioso o aleatorio) se determinó a partir de varios índices. Se identificaron 31 fragmentadores, los cuales se dividieron en especialistas (14 taxones), generalistas (10) y colectores-fragmentadores (7). Hubo un GO completo del gremio (0.75, p<0.001). Debido a su alta contribución de biomasa y de abundancia al gremio, y a la elevada proporción de tejido vegetal consumido, las cucarachas (Epilampra) fueron los fragmentadores-especialistas más representativos, superiores incluso a camarones y cangrejos. El camarón Potimirin fue el segundo taxón más importante seguido por el díptero Stenochironomus. Entre los insectos acuáticos, otros taxones de importancia secundaria fueron Leptohyphes (Ephemeroptera), Macrelmis, Anchytarsus y Tetraglosa (Coleoptera). Diez taxones mostraron un patrón espacial de contagio, y 21 se organizaron aleatoriamente, al igual que los recursos (i.e., “paquetes” de hojarasca). Aunque el gremio se organizó contagiosamente, estos resultados pudieron estar altamente influenciados por los taxones con distribución del mismo tipo. No se encontraron correlaciones significantes entre la abundancia media, la riqueza y la biomasa media con ninguna de las variables ambientales. Tres factores explicaron la alta riqueza y la abundancia de los fragmentadores en Isla Gorgona: (1) el origen continental, (2) su proximidad al continente (35km), y (3) la alta diversidad y disponibilidad de hojarasca y de desechos de madera dentro de las quebradas. Aunque cangrejos, camarones, insectos acuáticos y cucarachas-semiacuáticas coexistieron en la isla, estas últimas fueron, en términos de biomasa, los fragmentadores más importantes.

Patterns at Multi-Spatial Scales on Tropical Island Stream Insect Assemblages: Gorgona Island Natural National Park, Colombia, Tropical Eastern Pacific / Patrones en escalas multiespaciales en conjuntos de insectos de arroyos de islas tropicales: Parque Nacional Natural Isla Gorgona, Colombia, Pacífico Oriental Tropical

Tropical Eastern Pacific island streams (TEPis) differ from other neotropical streams in their rainy climate, mixed sedimentary-volcanic geology and faunal composition. Yet, their relationships between environmental characteristics and stream biota remain unexplored. We analyzed the environmental subject at three spatial scales using a fully nested sampling design (6 streams, 2 reaches within each stream, 2 habitats within each reach, and 4 replicates per habitat) on Gorgona Island (Colombia). Sampling was carried out in two months with contrasting rainfall during early 2009. We studied the spatial variation of assemblage composition and density along with 27 independent variables within two contrasting rainfall conditions. Five stream-scale variables, two reach-scale variables, and five habitat-scale variables were selected using a Canonical Correspondence Analysis (CCA). A partial CCA showed that the total variance explained was 13.98%, while stream- and habitat-scale variables explained the highest proportion of the variance (5.74 and 5.01%, respectively). Dissolved oxygen (as affected by rainfall), high-density use zone (a management category), and sedimentary geology were the best descriptors of insect assemblages. The two latter descriptors affected fine-scale variables such as total benthic organic matter and gravel substratum, respectively. A Nested ANOVA showed significant differences in total density and richness among streams and habitats, and significant differences between the two sampling months regardless of the spatial scale. The evenness showed a significant stream- and habitat-dependent temporal variability. These results suggested that rainfall regime in Gorgona Island might be a driver of insect assemblage dynamics mediated by water chemistry and substratum properties. Spatial assemblage variability here is greater within habitats (among samples), and a minor fraction occurs at habitat- and stream-scales, while no longitudinal pattern was observed probably due to the short courses. Temporal variability should be further studied relative to rainfall and discharge regimes. Rev. Biol. Trop. 62 (Suppl. 1): 65-83. Epub 2014 February 01.

Las quebradas insulares del Pacífico Tropical Oriental difieren de otras quebradas neotropicales en términos de regímenes de lluvia, geología sedimentaria-volcánica, y composición faunística; pero la relación entre características ambientales y la biota de estas quebradas insulares permanece inexplorada. En este estudio, conducido en Isla Gorgona, se analizó el efecto restrictivo de 27 variables ambientales sobre la distribución, composición y densidad de los insectos acuáticos en tres escalas espaciales; se consideraron además diferencias en las intensidades de la lluvia entre los muestreos. Los muestreos se realizaron en 2009, en dos meses con intensidades de lluvia contrastantes; se siguió un diseño muestral anidado (6 quebradas, 2 tramos en cada quebrada, 2 hábitats en cada tramo, y 4 réplicas por hábitat). En un ACC fueron seleccionadas 5 variables operando a la escala-quebrada, 2 a la escala-tamo y 5 a la escala-hábitat. Un ACC parcial mostró que la varianza total explicada fue de 13.98%; las variables de las escalas hábitat y quebrada explicaron la mayor proporción (5.74 y 5.01%, respectivamente). Los mejores descriptores del “ensamblaje” fueron, oxígeno disuelto (influenciado por la lluvia), zona de alta densidad de uso y geología sedimentaria. Las dos últimas afectaron variables de escalas menores tales como, materia orgánica béntica y sustrato de gravas. Un ANOVA anidado presentó diferencias significativas de densidad total y de riqueza entre quebradas y hábitats, así como entre meses. La equidad mostró una variabilidad temporal significante dependiente de la quebrada y del hábitat. Se sugiere que el régimen de lluvia podría ser el conductor principal de las dinámicas, pues influye en la química del agua y en las propiedades de los sustratos. La variabilidad espacial de la composición y la estructura es mayor dentro de los hábitats (entre las muestras), y en menor proporción en las escalas quebrada y hábitat. No se definió un patrón longitudinal debido probablemente a la corta longitud de las quebradas. La variabilidad temporal debe ser estudiada a fondo en función de los regímenes de lluvia y de descarga.

Gorgona, Baudó y Darién (Chocó Biogeográfico, Colombia): ecorregiones modelo para los estudios ecológicos de comunidades de quebradas costeras / Gorgona, Baudó and Darién (Biogeographic Chocó, Colombia): model ecoregions for coastal stream ecology studies

This paper summarizes the available information on the geology, hydrology, and biota of coastal streams located in the Gorgona National Natural Park (GNNP), and the Baudó and Darién ecoregions within the Biogeographic Chocó (Colombia). Despite of the scant number of studies, we hypothesized that these streams are consistent with the typology observed in volcanic oceanic islands in the Caribbean and the Pacific that do not conform to the tenets of the River Continuum Concept. Coastal streams in the Biogeographic Chocó are short (10(0)-10¹km) and steep and waterfalls and cascades are frequent due to tectonic origin. Step-and-pool sequences are common in montane reaches, while cobble-bed glides and riffles dominate in coastal plain reaches. Flow regimes are flashy in Pacific drainages (annual rainfall: <7000mm), but seasonally dry in the Caribbean drainages (<3500mm). Therefore, floods and droughts are important drivers of communities and ecosystem processes. Canopies are closed in low-order streams discharging directly to the ocean, thus contributing large amounts of litter. Diadromous fish and shrimp dominate consumer assemblages and various species are shared with streams in the Central America and the Antilles. These species play ecological roles probably equivalent to those found in other regions. These coastal streams are unique in terms of the number of primary freshwater fishes found (some endemics), and the functionally absence of diadromous gastropods. Rev. Biol. Trop. 62 (Suppl. 1): 43-64. Epub 2014 February 01.

A pesar de la escasez de estudios sobre la geología, hidrología y biota de las quebradas costeras ubicadas en el Chocó Biogeográfico, se hipotetiza que éstas se ajustan a la tipología observada en las islas oceánicas volcánicas del Caribe y el Pacífico, las cuales no cumplen con las predicciones del Concepto del Río Continuo. Estas quebradas son cortas (<10¹km) y muy pendientes debido a su origen tectónico, y presentan lechos dominados por bloques y cantos rodados. El régimen de caudal es torrencial en la vertiente Pacífico, pero estacionalmente seco en la vertiente Caribe. Los doseles cerrados aportan grandes cantidades de hojarasca a las quebradas que desembocan al mar con bajo orden. Las especies diádromas, con afinidades centroamericanas y antillanas, dominan los ensamblajes y posiblemente cumplen papeles ecológicos equivalentes a los establecidos en otras regiones. Particularmente, las quebradas costeras de esta provincia presentan varias especies de peces dulceacuícolas primarios, algunas endémicas, y carecen de gasterópodos. Los procesos geomorfológicos e hidrológicos de las cabeceras influyen sobre la dinámica ecosistémica de estas quebradas. Se proponen cinco hipótesis sobre la estructura y composición comunitaria. Se advierte que el PNNG es un modelo útil para la ecología lótica costera, pero que tiene particularidades.

Efecto de la conversión del manglar a potrero sobre la densidad y tallas de dos gasterópodos en el delta del río Turbo (golfo de Urabá, Caribe colombiano) / Effects mangrove conversion to pasture on density and shell size of two gastropods in the Turbo River Delta (Urabá Gulf, Caribbean coast of Colombia)

Mangrove deforestation is widespread in the Greater Caribbean but its impact on macrobenthos has not been evaluated to date. In order to assess the impact of mangrove conversion to pasture, densities and shell sizes of two dominant gastropods (Neritina virginea and Melampus coffeus) were compared among four mangrove types: 1) Rhizophora mangle-dominated fringing mangroves, 2) Avicennia germinans-dominated basin mangroves, 3) Mixed-species basin mangroves, and 4) A. germinansbasin mangroves converted to pastures, in the Turbo River Delta (Urabá Gulf, Colombia). Mangrove types were polygon-delimited with satellite images and color aerial photographs were taken in 2009. various (n<5) polygons per mangrove type were sampled in January, July and December 2009, and a total (n<20) 0.025m²-quadrats were randomly placed along each polygon. Forest structure variables, pore-water physico-chemical variables and sediment-grain metrics were measured in the four mangrove types. Mean density and size of both gastropod species were measured. The results showed that the mean density and size of both species were significantly greater in R. mangle-fringing mangroves. N. virginea density decreased gradually towards the A. germinans-basin mangroves seemly related to the diadromous life-history. This species nearly disappeared in the neighboring pastures because individuals were constrained to a few remaining flooded areas. In the pastures, M. coffeus individuals were clumped in the remaining A. germinans trees due to its climbing behavior as a pulmonate. We hypothesize that the decline of these two gastropods was related to physical microhabitat (e.g. trees, prop roots, and seedlings) degradation, and alteration of soil properties (e.g. temperature, pH, organic matter content). Finally, we also hypothesize that the local extinction of N. virginea due to clear-cutting may exert strong negative effects on the ecosystem function because it is a dominant omnivore.

El delta del río Turbo es una de las áreas del golfo de Urabá, Colombia donde la tala de manglar es más extensa y activa, por lo tanto, se evaluó el impacto de la conversión de manglar a potrero, comparando la densidad y talla promedio de dos gasterópodos (Neritina virginea y Melampus coffeus), variables dasonómicas, físico-químicas intersticiales y granulométricas del suelo entre varios parches de: 1) manglar de franja, 2) manglar de cuenca, 3) manglar de cuenca mixto y 4) manglar de cuenca convertido a potrero, en el delta del río Turbo de este golfo, entre enero y diciembre 2009. Las densidades y tallas de los gasterópodos fueron mayores en el manglar de franja. N. virginea fue muy abundante pero disminuyó hacia el manglar de cuenca (debido a sus hábitos diádromos), y desapareció casi completamente en los potreros, donde los individuos estuvieron agregados en las pocas áreas anegadas. En los potreros, los individuos de M. coffeus estuvieron agrupados en los árboles remanentes debido a su hábito arborícola y su condición de pulmonado. Se sugiere que la escasez de los gasterópodos está relacionada con la degradación del microhábitat físico, y la alteración de propiedades del suelo. Finalmente, también planteamos que la extinción local de N. virginea debida a la tala puede ejercer fuertes efectos negativos sobre la función ecosistémica debido a que es un omnívoro dominante.

[Effects mangrove conversion to pasture on density and shell size of two gastropods in the Turbo River Delta (Urabá Gulf, Caribbean coast of Colombia)]. / Efecto de la conversión del manglar a potrero sobre la densidad y tallas de dos gasterópodos en el delta del río Turbo (golfo de Urabá, Caribe colombiano).

Mangrove deforestation is widespread in the Greater Caribbean but its impact on macrobenthos has not been evaluated to date. In order to assess the impact of mangrove conversion to pasture, densities and shell sizes of two dominant gastropods (Neritina virginea and Melampus coffeus) were compared among four mangrove types: 1) Rhizophora mangle-dominated fringing mangroves, 2) Avicennia germinans-dominated basin mangroves, 3) Mixed-species basin mangroves, and 4) A. germinans- basin mangroves converted to pastures, in the Turbo River Delta (Urabá Gulf, Colombia). Mangrove types were polygon-delimited with satellite images and color aerial photographs were taken in 2009. Various (n<5) polygons per mangrove type were sampled in January, July and December 2009, and a total (n<20) 0.025m2-quadrats were randomly placed along each polygon. Forest structure variables, pore-water physicochemical variables and sediment-grain metrics were measured in the four mangrove types. Mean density and size of both gastropod species were measured. The results showed that the mean density and size of both species were significantly greater in R. mangle-fringing mangroves. N. virginea density decreased gradually towards the A. germinans-basin mangroves seemly related to the diadromous life-history. This species nearly disappeared in the neighboring pastures because individuals were constrained to a few remaining flooded areas. In the pastures, M. coffeus individuals were clumped in the remaining A. germinans trees due to its climbing behavior as a pulmonate. We hypothesize that the decline of these two gastropods was related to physical microhabitat (e.g. trees, prop roots, and seedlings) degradation, and alteration of soil properties (e.g. temperature, pH, organic matter content). Finally, we also hypothesize that the local extinction of N. virginea due to clear-cutting may exert strong negative effects on the ecosystem function because it is a dominant omnivore.

New model to explain the EQ-5D VAS in patients who have undergone spinal fusion.

BACKGROUND: In the health sector, the EQ-5D has been widely used to evaluate health-related quality of life, mainly due to its simplicity, robustness and plasticity in calculating years of life adjusted for quality. METHODS: However, its model has remained stable over time and knowledge of the influence of such biodemographical variables as age and gender has not been incorporated. This information, along with the well-known non-linear behavior of the VAS, which measures the self-concept of the 'General State of Health', forms the basis for a new model, which we present here from a sample of patients who were operated on for chronic low back pain. RESULTS: These are obtained using multiple regression analysis are consistent in terms of goodness-of-fit given that this new model is able to explain 91.3% of the self-concept of the 'general state of health'. CONCLUSIONS: Above leads to an improvement of 21.6% compared to the available models more robust and meets most of the restrictions for this type of statistical modeling.