{"id":144409,"date":"2014-05-03T14:49:50","date_gmt":"2014-05-03T13:49:50","guid":{"rendered":"http:\/\/www.madrimasd.org\/blogs\/universo\/?p=144409"},"modified":"2014-05-03T14:50:37","modified_gmt":"2014-05-03T13:50:37","slug":"accidentes-cerebrovasculares-y-propiedades-del-suelo","status":"publish","type":"post","link":"https:\/\/www.madrimasd.org\/blogs\/universo\/2014\/05\/03\/144409","title":{"rendered":"Accidentes cerebrovasculares y propiedades del suelo"},"content":{"rendered":"

Hoy os ofrecemos una noticia muy interesante acerca de\u00a0las posibles relaciones de las propiedades de los suelos y la salud humana<\/strong><\/span>. No obstante adelantemos que se trata de una conjetura de ciertos investigadores norteamericanos que a\u00fan debe ser seriamente\u00a0 corroborada<\/strong><\/span>. De acuerdo con estos cient\u00edficos existe una correlaci\u00f3n positiva entre\u00a0 accidentes cardiovasculares, suelos con mal drenaje, niveles fre\u00e1ticos elevados y pH \u00e1cido<\/strong><\/span>. Seg\u00fan alegan, posiblemente\u00a0se deba a que ambos atesoren comunidades microbianas idiosincr\u00e1sicas, que en contacto con los seres humanos <\/strong><\/span>(especialmente ni\u00f1os), favorezcan que, a corto, medio o largo plazo sean afectados por esta enfermedad<\/strong><\/span>, denominada en la nota de prensa del Bolet\u00edn de noticias ARS (apoplej\u00eda o derrames cerebrales<\/a>). Los investigadores conjeturan pues que los microorganismos del suelo afectan a los que albergamos en el interior de nuestro cuerpo<\/strong> <\/span>(microbioma humano<\/a>). Se tratar\u00eda de un condicionamiento ambiental que ponen en contacto ambas comunidades microbianas afect\u00e1ndonos, para bien, o para mal, a la hora de padecer o no, ciertas enfermedades<\/strong><\/span>. Obviamente, resulta plausible que as\u00ed sea. Ahora bien, el estudio llevado a cabo ofrece unos resultados que bien pudieran ser correctos o el resultado de<\/strong><\/span> correlaciones espurias<\/a>, que ocultan otras subyacentes, las cuales podr\u00edan ser la verdadera raz\u00f3n de la causa-efecto, pero no han sido tenidas en cuenta. Y mento tal hecho ya que en el estudio de marras nadie ha analizado las relaciones microbiol\u00f3gicas entre el microbioma y las comunidades del suelo<\/strong> <\/span>en ciertas \u00e1reas geogr\u00e1ficas (como por ejemplo la \u00abZona de Apoplej\u00eda\u00bb en la parte sudeste de EE.UU<\/strong><\/span>.) donde los accidentes cardiovasculares son mucho m\u00e1s frecuentes de lo normal, como bien se detalla en la notas de prensa (corta en espa\u00f1ol y larga en ingl\u00e9s) aparecida en el Bolet\u00edn del ARS. \u00a0Sin embargo un meta-an\u00e1lisis del estudio ofrece otros detalles interesantes<\/strong><\/span>.<\/p>\n

\u00a0\"ars-mapa-de-suelos-y-mapa-de-apoplejia-boletin-ars\"<\/p>\n

Mapa de Apoplej\u00eda vs mapa del terreno<\/a><\/p>\n

En principio, los estudios fueron llevados a cabo comparando los mapas de suelos con los de incidencia de la enfermedad mencionada. Sin embargo<\/strong><\/span>, debido a que las propiedades del suelo pueden variar considerablemente dentro de un mismo tipo o pedotaxa, finalmente se utilizaron variables concretas haci\u00e9ndose adicionalmente uso de la geoestad\u00edstica<\/strong>. \u00a0De este modo se alcanzaron<\/span> mejores resultados<\/strong> <\/span>(correlaciones positivas o negativas entre la afecci\u00f3n y variables ed\u00e1ficas). Tal hecho no es \u00f3bice para que puedan persistir correlaciones espurias<\/a>, como suele ocurrir en este tipo de investigaciones multifactoriales. Finalmente, los investigadores implicados apelan a que recogiendo y analizando unos pocos cientos de muestras de comunidades microbianas para estudiar su genoma (c\u00f3digo de barras gen\u00e9tico) podr\u00eda elaborarse una cartograf\u00eda microbiana de la regi\u00f3n apta para seguir indagando sobre las causas-efectos<\/strong><\/span> de este intrigante \u201cdescubrimiento\u201d con mejores herramientas. No obstante omiten que la misma estrategia deber\u00eda emplearse con el microbioma y genoma de los ciudadanos que habitan en el lugar, ya que se encuentran condicionadas por la alimentaci\u00f3n y otros factores ambientales. Eso s\u00ed, por fin podr\u00edan llevarse a cabo mapas de la microbiolog\u00eda del suelo por cuanto la salud humana mueve ingentes cantidades de dinero, al contrario que la investigaci\u00f3n b\u00e1sica a cerca de la microbiolog\u00eda del suelo<\/strong><\/span>. De este modo, de darse el caso de que la conjetura de estos investigadores estadounidenses fuera cierta, nos proporcionar\u00eda a los expertos en ciencia del suelo una oportunidad \u00fanica a la hora de\u00a0progresar en la comprensi\u00f3n de la ecolog\u00eda del suelo<\/strong><\/span>.<\/p>\n

Empero el estudio da para mucho m\u00e1s, por cuanto las implicaciones para la salud son de gran calado. Analizaremos el tema en otro post pero hoy nos plantearemos la siguiente pregunta. \u00a0Si los microbianas humanos se encuentran afectados por las comunidades microbianas del ambiente que les rodean<\/strong><\/span> (hecho del que ya casi nadie duda), las mayores tasas de afecci\u00f3n de los accidentes cerebrales podr\u00edan ser un efecto colateral de otras adaptaciones quiz\u00e1s m\u00e1s benignas<\/strong> <\/span>para la salud p\u00fablica aun no esclarecidas. Ya hablaremos de este asunto. Por cierto soslayaba que la acidez de un horizonte superficial de un suelo no se encuentra necesariamente relacionada con el nivel de la capa fre\u00e1tica, salvo en ciertos casos (por ejemplo, cuando las aguas del acu\u00edfero se encuentran muy, pero que muy cerca de la superficie). \u00bfSer\u00eda pues un efecto sin\u00e9rgico de dos o m\u00e1s propiedades ed\u00e1ficas en lugar de una?<\/p>\n

Juan Jos\u00e9 Ib\u00e1\u00f1ez<\/strong><\/span><\/p>\n

<\/span><\/p>\n

Resultados de estudio sugieren una conexi\u00f3n entre las caracter\u00edsticas del suelo y el riesgo del ataque de apoplej\u00eda<\/strong><\/span><\/p>\n

Por Ann Perry<\/a>; 22 de agosto de 2013<\/p>\n

Microbioma humano<\/a><\/p>\n

Los resultados de un estudio por cient\u00edficos del Servicio de Investigaci\u00f3n Agr\u00edcola<\/a> (ARS) y sus colegas sugieren que en algunas partes del estado de Carolina del Sur, el riesgo del ataque de apoplej\u00eda podr\u00eda ser relacionado en parte con las caracter\u00edsticas de los suelos en esa regi\u00f3n<\/strong>. Estos hallazgos podr\u00edan proveer nueva informaci\u00f3n imprescindible para investigar los factores relacionados con la frecuencia de la <\/strong>apoplej\u00eda<\/a> (accidente cardiovascular).<\/p>\n

La investigaci\u00f3n fue realizada por profesor Daniel Lackland de la Universidad M\u00e9dica de Carolina del Sur<\/a> y l\u00edder de investigaci\u00f3n Patrick Hunt<\/a>, microbi\u00f3logo Thomas Ducey<\/a> y cient\u00edfico del suelo Jarrod Miller<\/a> con el ARS. Los cient\u00edficos del ARS trabajan en el Centro de Investigaci\u00f3n del Suelo, el Agua y las Plantas de las Llanuras Costeras<\/a> mantenido por el ARS en Florence, Carolina del Sur. Cient\u00edfico del suelo Warren Busscher, quien trabaj\u00f3 en el laboratorio en Florence antes de su jubilaci\u00f3n, tambi\u00e9n contribuy\u00f3 al proyecto. ARS es la agencia principal de investigaciones cient\u00edficas del Departamento de Agricultura de EE.UU.<\/a> (USDA por sus siglas en ingl\u00e9s).<\/p>\n

Para identificar las conexiones entre el riesgo de la apoplej\u00eda y las caracter\u00edsticas del suelo, los cient\u00edficos compararon 10 a\u00f1os de datos sobre los enfermos en las urgencias en Carolina del Sur con informaci\u00f3n en una base de datos sobre los suelos del estado. Ellos descubrieron correlaciones significativas entre las tasas de frecuencia de la apoplej\u00eda, la profundidad del suelo al agua subterr\u00e1nea, y la capacidad de drenaje del suelo<\/strong>.<\/p>\n

El grupo se concentr\u00f3 en las caracter\u00edsticas de los suelos en los condados de Carolina del Sur donde se encuentran las tasas m\u00e1s altas de ataques de apoplej\u00eda\u2014todos dentro de la regi\u00f3n de las Llanuras Costeras\u2014y los condados que tienen las tasas m\u00e1s bajas de ataques de apoplej\u00eda, todos dentro de la regi\u00f3n de la Cresta Azul\/Piedmonte.<\/p>\n

Los resultados indicaron que los suelos con una profundidad de 20 a 59 pulgadas al agua subterr\u00e1nea fueron relacionados con tasas m\u00e1s altas de mortalidad causada por los ataques de apoplej\u00eda, semejantes a las \u00e1reas con suelos que tienen drenaje mediano o pobre, y suelos altamente \u00e1cidos<\/strong>. Los investigadores tambi\u00e9n observaron que los suelos con buen drenaje y suelos con una profundidad de por lo menos 72 pulgadas al agua subterr\u00e1nea tuvieron una correlaci\u00f3n negativa<\/strong>.<\/p>\n

Los suelos con drenaje mediano o pobre y las caracter\u00edsticas de los suelos altamente \u00e1cidos en las \u00e1reas con tasas m\u00e1s altas de mortalidad causada por la apoplej\u00eda se encuentran t\u00edpicamente en el \u00e1rea de las Llanuras Costeras<\/strong>. Si esta correlaci\u00f3n entre las caracter\u00edsticas del suelo y el riesgo de ataques de apoplej\u00eda es real, los cient\u00edficos piensen que la conexi\u00f3n biol\u00f3gica podr\u00eda incluir la prevalencia\u2014o la falta\u2014de microbios espec\u00edficos en los suelos h\u00famedos y \u00e1cidos de la regi\u00f3n, los cuales pueden ser muy diferentes de los microbios que viven en los suelos m\u00e1s secos<\/strong>.<\/p>\n

No se sabe c\u00f3mo estos microbios del suelo podr\u00edan afectar espec\u00edficamente la salud humana. Pero las caracter\u00edsticas biogeoqu\u00edmicas podr\u00edan proveer informaci\u00f3n para aumentar los conocimientos sobre el estilo de vida, los factores ambientales y los factores gen\u00e9ticos en explicar el enigma de la \u00abZona de Apoplej\u00eda\u00bb en la parte sudeste de EE.UU.<\/p>\n

Los resultados de este estudio fueron publicados en ‘Journal of Environmental Science and Health<\/a>‘ (Revista de la Ciencia Ambiental y la Salud) en el 2012.<\/p>\n

Lea m\u00e1s<\/a> sobre este estudio en la revista ‘Agricultural Research’ de agosto del 2013.<\/p>\n

Nota De prensa Extensa en Ingl\u00e9s<\/strong><\/span><\/p>\n

So one day in 2011, Hunt called Medical University of South Carolina professor Daniel Lackland to discuss a paper Lackland had published about stroke risk in the state. South Carolina is part of the U.S. \u201cStroke Belt,\u201d where residents have a significantly higher incidence of stroke than the rest of the U.S. population<\/strong>. South Carolina counties with the highest rates of stroke<\/strong>\u2014between 89 and 115 cases per 100,000 residents\u2014are found within the Southern Coastal Plain, which \u201cbuckles\u201d the Stroke Belt (see map<\/a>).<\/p>\n

Lackland had determined that South Carolina stroke victims in the state\u2019s Pee Dee region\u2014located in the Stroke Belt \u201cbuckle<\/strong>\u201d\u2014were on average 10 years younger than stroke victims outside the Belt<\/strong>. His studies also indicated that individuals born in the Stroke Belt have an increased risk of stroke in their lifetime, a risk that remained even if they moved away from the Stroke Belt later<\/strong>. He had identified some very intriguing trends<\/strong>, but he did not fully understand what might be driving those trends.<\/p>\n

\u201cOver the past 30 years, I\u2019ve been involved with research projects focused on racial and geographical disparities in stroke risk<\/strong>,\u201d Lackland says. \u201cOne of the major objectives of these investigations is to identify factors associated with the high stroke risk in this part of the country. Unhealthy lifestyle and the Southern diet are often proposed as reasons for the disparities. But similar high-fat and high-carbohydrate diets are seen in other parts of the country<\/strong>. So we must study other factors.\u201d<\/p>\n

Mapping the Odds<\/strong><\/p>\n

As a result of their initial talks, Lackland and Hunt began to collaborate with ARS microbiologist Tom Ducey and ARS soil scientist Jarrod Miller<\/strong> to support Lackland\u2019s epidemiological research with some environmental expertise. The three ARS scientists work at the ARS Coastal Plains Soil, Water<\/strong>, and Plant Research Center in Florence, South Carolina. Retired ARS soil scientist Warren Busscher, who worked at the Florence laboratory, also contributed to the project.<\/p>\n

\u201cLackland\u2019s results indicated that stroke risk was not just related to diet or lifestyle choices<\/strong>,\u201d says Ducey. \u201cThey strongly suggested that an environmental factor<\/strong> was at work as well.\u201d So the team designed a study to determine whether certain soil characteristics in the region\u2019s sandy Carolina Coastal Plain soils could serve as risk markers for stroke and whether those characteristics could be pinpointed by geostatistical analysis<\/strong>.<\/p>\n

\u201cLooking at soil patterns and stroke patterns was a reasonable place to start<\/strong>,\u201d Lackland says. \u201cIn addition, we were able to assess the links using data that were already available, which was a very efficient use of existing resources.\u201d<\/p>\n

To identify associations between stroke risk and soil characteristics<\/strong>, the researchers obtained 10 years of<\/strong> South Carolina inpatient and emergency room discharge data that listed stroke as a primary diagnosis and compared it to state soil data from the USDA Natural Resources Conservation Service (NRCS) Soil Survey Geographic database. The soil characteristics evaluated in the research included cation exchange capacity; hydrologic soil group; sand, silt, clay, and organic matter content; saturated hydraulic conductivity; depth to water table; septic suitability; soil surface acidity; drainage class; and flooding frequency<\/strong>.<\/p>\n

In their initial analysis, the team found that stroke rates were significantly correlated with depth to water table and soil drainage class. Stroke rates were higher in counties where soil depth to water table was between 20 and 59 inches, which is often the case for shallow water tables<\/strong> in the Coastal Plain. (Soils with water tables less than 20 inches deep are usually found in flood-prone areas near streams, rivers, or wetlands\u2014sites that are generally unsuitable for residential use<\/strong>.) Links between stroke rate and soil drainage were also significant<\/strong>: Well-drained soils had a negative correlation<\/strong> (fewer strokes), while poorly drained soils were positively correlated <\/strong>(more strokes).<\/p>\n

\u201cThese links,\u201d Ducey comments, \u201cgive the scientific community a good foundation for developing further studies of the geographic distribution of stroke risk.\u201d<\/p>\n

The team then focused their investigation on soil characteristics in South Carolina counties with the 10 highest stroke rates\u2014all within the Coastal Plain\u2014and those with the 10 lowest stroke rates, all in the Blue Ridge\/Piedmont region. Findings from this part of the study indicated that soils with a depth to water table from 20 to 59 inches continued to be strongly correlated with stroke rate, while soils with a depth to water table of more than 79 inches were negatively correlated.<\/p>\n

Moderately well-drained to poorly drained soils were also positively correlated with stroke rate, while well-drained soils had a negative correlation. In addition, strongly acidic soils had a strong positive correlation with stroke rate<\/strong>.<\/p>\n

In short, soil characteristics with strong positive correlations to stroke risk were all typical of Coastal Plain soils<\/strong>.<\/p>\n

\u201cI had a suspicion this is what we would find,\u201d Ducey said. \u201cIt was clear that the Stroke Belt map aligned with the Coastal Plains soils map<\/strong> and that the distribution of stroke rates didn\u2019t show any real links to the location of the hilly and rocky Piedmont soils.\u201d<\/p>\n

\u201cIn general, soil maps show the location of very broad categories of soil characteristics<\/strong>,\u201d Miller adds. \u201cSo given the broad nature of the data, it was very interesting that we found any correlations at all between soil characteristics and stroke risk<\/strong>.\u201d<\/p>\n

Risky Terrain<\/strong><\/p>\n

There are two classic factors that affect the makeup of soil microbial communities: soil moisture and soil acidity. A different diversity of organisms can be found in moist, acidic soils than in drier, more alkaline soils<\/strong>. Based on this, the researchers hypothesize that Coastal Plain residents might be at higher risk for stroke because of the prevalence\u2014or perhaps lack\u2014of specific microbes in the region\u2019s moist, acidic soils. The scientists all strongly concur that this hypothesis will need much more testing and validation<\/strong> before it can be confirmed.<\/p>\n

Discussions about how these soil microbes could specifically affect human health, including stroke risk, are just beginning<\/strong>. But researchers in a range of disciplines are now exploring how health and disease can be affected<\/strong> by the huge numbers of bacteria, viruses, and other microbes that live in the human body. This impressive assortment of microbes, which is called a \u201cmicrobiome<\/strong>,\u201d varies from person to person, depending on what each person is exposed to\u2014and when the exposure occurs\u2014throughout a lifetime.<\/p>\n

Based on their findings, the South Carolina scientists hypothesize that an early-life exposure to the specific microbial mix in Coastal Plain soils might affect microbiome development in a way that leaves some individuals more vulnerable to cardiovascular events like stroke<\/strong>. Although this effect would vary from person to person, depending on other environmental and genetic factors, it might help explain the puzzling regional patterns of stroke risk.<\/p>\n

\u201cI\u2019m not totally surprised by these results, but I was surprised by the magnitude of correlation between soil characteristics and stroke risk<\/strong>,\u201d says Lackland. \u201cThis is a preliminary study, and it needs additional<\/strong> follow-up and confirmation<\/strong>. But if other studies have similar results, it could provide new information about risk factors for stroke and allow us to develop new interventions that could help reduce stroke rates in this region.\u201d<\/p>\n

Because of data constraints, the study was restricted to South Carolina. But the Southern Coastal Plain extends from Virginia through the Carolinas, Georgia, and the Florida panhandle, as well as into Alabama, Mississippi, Louisiana, and Kentucky. All these regions are recognized as part of the Stroke Belt<\/strong>.<\/p>\n

NRCS currently doesn\u2019t collect data on the distribution of soil microbial populations<\/strong>, so there are no clues about which microbes might be the environmental link between Coastal Plains soils and stroke risk. Ducey contends that information about soil microbe communities could be acquired using new biotech instruments<\/strong> in laboratories such as the ARS lab in Florence. In this way, data generated by ARS to benefit agriculture would benefit epidemiology as well<\/strong>.<\/p>\n

\u201cA microbial map of South Carolina could be developed from approximately 300 to 400 soil samples<\/strong>. This could allow microbial populations to be looked at in future studies,\u201d Ducey says.<\/p>\n

\u201cThis study helps broaden the thinking about the different factors that might be involved in this serious health problem,\u201d says Hunt. \u201cIt shows how sharing theories and technologies across scientific disciplines can result in valuable outcomes.\u201d<\/p>\n

\u201cWe\u2019ve known about the geographical and racial disparities in stroke risk for five decades,\u201d Lackland agrees. \u201cWe\u2019ve identified many of the factors, including high blood pressure and diabetes, that increase stroke risk, but we still don\u2019t have a comprehensive answer for why some parts of the population suffer excessive stroke rates<\/strong>. This work could be an important step in that direction.\u201d<\/p>\n

The team published its findings in 2012 in the Journal of Environmental Science and Health<\/em><\/strong>.<\/em>\u2014By Ann Perry<\/strong><\/a>,<\/strong> Agricultural Research Service Information Staff.<\/p>\n

This research is part of Climate Change, Soils, and Emissions (#212) and Water Availability and Watershed Management (#211), two ARS national programs described at <\/em>www.nps.ars.usda.gov<\/em><\/a>.<\/em><\/p>\n

To reach the scientists mentioned in this story, contact <\/em>Ann Perry<\/em><\/a>, USDA-ARS <\/em>Information Staff<\/em><\/a>, 5601 Sunnyside Ave., Beltsville, MD 20705-5128; (301) 504-1628.<\/em><\/p>\n

\u00abARS Scientists Explore Possible Links Between Soil Microbial Communities and Stroke Risk\u00bb<\/strong> was published in the August 2013<\/strong><\/a> issue of Agricultural Research <\/em>magazine<\/p>\n","protected":false},"excerpt":{"rendered":"

Hoy os ofrecemos una noticia muy interesante acerca de\u00a0las posibles relaciones de las propiedades de los suelos y la salud humana. No obstante adelantemos que se trata de una conjetura de ciertos investigadores norteamericanos que a\u00fan debe ser seriamente\u00a0 corroborada. De acuerdo con estos cient\u00edficos existe una correlaci\u00f3n positiva entre\u00a0 accidentes cardiovasculares, suelos con mal drenaje, niveles fre\u00e1ticos elevados y pH \u00e1cido. Seg\u00fan alegan, posiblemente\u00a0se deba a que ambos atesoren comunidades microbianas idiosincr\u00e1sicas, que en contacto con los seres humanos (especialmente ni\u00f1os), favorezcan que, a corto, medio o largo plazo sean afectados por esta enfermedad, denominada en la nota de\u2026<\/p>\n","protected":false},"author":26,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0},"categories":[596,603,590,592,606],"tags":[20678,20679,20680,47492],"blocksy_meta":{"styles_descriptor":{"styles":{"desktop":"","tablet":"","mobile":""},"google_fonts":[],"version":4}},"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/144409"}],"collection":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/users\/26"}],"replies":[{"embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/comments?post=144409"}],"version-history":[{"count":8,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/144409\/revisions"}],"predecessor-version":[{"id":145573,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/144409\/revisions\/145573"}],"wp:attachment":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/media?parent=144409"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/categories?post=144409"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/tags?post=144409"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}