Carlos Sierra

This study looks at aspects of the environmental health of the rural population in Timbío (Cauca, Columbia) in relation to the deterioration of water quality. The information was obtained through participatory research methods exploring the management and use of water, the sources of pollution and the perception of water quality and its relation to Helicobacter pylori infection. The results are part of the qualitative analysis of a first research phase characterizing water and sanitation problems and their relation to emerging infectious diseases as well as possible solutions, which was carried out between November 2013 and August 2014. The results of this research are discussed from an ecosystemic approach to human health, recognizing the complexity of environmental conflicts related to water resources and their impacts on the health of populations. Through the methodology used, it is possible to detect and visualize the most urgent problems as well as frequent causes of contaminat...

A complete evaluation of the patient with ischemic heart disease requires an anatomical and functional assessment of the myocardium and coronary arteries. Recent technological advances have allowed a quantitative and physiological evaluation of the cardiovascular system with Positron Emission Tomography (PET). This method is a valuable tool for the assessment of heart metabolism, myocardial perfusion, ventricular function, coronary blood flow, myocardial viability and endothelial function. One of the major limitations of a PET study is its low spatial resolution. Cardiac Computed Tomography (CCT) is an anatomic study used for coronary calcium quantification, evaluation of wall and lumen of coronary arteries, study of vascular permeability and assessment of composition, extension and severity of atherosclerotic plaques. The main limitation of CCT is the lack of functional information that is obtained with this technique. Both methods are complementary in many ways. That is the reason of the wide spread of PET-CT hybrid equipments that can provide very useful functional and anatomic information of patients with ischemic heart disease in a single exploration.

ABSTRACT Soil organic matter is a complex mixture of material with heterogeneous biological, physical, and chemical properties. Decomposition models represent this heterogeneity either as a set of discrete pools with different residence times or as a continuum of qualities. It is unclear though, whether these two different approaches yield comparable predictions of organic matter dynamics. Here, we compare predictions from these two different approaches and propose an intermediate approach to study organic matter decomposition based on concepts from continuous models implemented numerically. We found that the disagreement between discrete and continuous approaches can be considerable depending on the degree of nonlinearity of the model and simulation time. The two approaches can diverge substantially for predicting long-term processes in soils. Based on our alternative approach, which is a modification of the continuous quality theory, we explored the temporal patterns that emerge by treating substrate heterogeneity explicitly. The analysis suggests that the pattern of carbon mineralization over time is highly dependent on the degree and form of nonlinearity in the model, mostly expressed as differences in microbial growth and efficiency for different substrates. Moreover, short-term stabilization and destabilization mechanisms operating simultaneously result in long-term accumulation of carbon characterized by low decomposition rates, independent of the characteristics of the incoming litter. We show that representation of heterogeneity in the decomposition process can lead to substantial improvements in our understanding of carbon mineralization and its long-term stability in soils.

Prolonged aerobic exercise, such as running a marathon, produces supraphysiological stress that can affect the athlete's homeostasis. Some degree of transient myocardial dysfunction ("cardiac fatigue") can be observed for several days after the race. To verify if there are changes in the cardiopulmonary capacity, and cardiac inotropy and lusitropy in amateur marathoners after running a marathon. The sample comprised 6 male amateur runners. All of them underwent cardiopulmonary exercise testing (CPET) one week before the São Paulo Marathon, and 3 to 4 days after that race. They underwent echocardiography 24 hours prior to and immediately after the marathon. All subjects were instructed not to exercise, to maintain their regular diet, ingest the same usual amount of liquids, and rest at least 8 hours a day in the period preceding the CPET. The athletes completed the marathon in 221.5 (207; 250) minutes. In the post-marathon CPET, there was a significant reduction in peak oxygen consumption and peak oxygen pulse compared to the results obtained before the race (50.75 and 46.35 mL.kg-1 .min-1; 19.4 and 18.1 mL.btm, respectively). The echocardiography showed a significant reduction in the s' wave (inotropic marker), but no significant change in the E/e' ratio (lusitropic marker). In amateur runners, the marathon seems to promote changes in the cardiopulmonary capacity identified within 4 days after the race, with a reduction in the cardiac contractility. Such changes suggest that some degree of "cardiac fatigue" can occur.

Takayasu's arteritis is a primary vasculitis that affects large vessels and is characterized by chronic granulomatous inflammation. Diagnosis has been primarily clinical, with verification by angiography as the gold standard. More recently, however, it has become apparent that positron emission tomography enables better evaluation of vascular inflammation.This study presents 2 cases of Takayasu's arteritis. Magnetic resonance angiography was used to evaluate aortic anatomy by analyzing vascular wall thickness and also to quantify disease activity by measuring gadolinium enhancement. Positron emission tomography was used to evaluate active vascular inflammation by quantifying fluorodeoxyglucose F18 uptake. We conclude that both techniques support clinical diagnosis and aid in the evaluation of disease activity during and after treatment.

Our objective was to investigate enteric los of proteins in a group of selected patients, which frequently is not taken into account in the clinical management of these patients. We included 20 healthy children (group I), 10 pediatric patients with heart disease (group II) and 20 pediatric patients with gastrointestinal disease (group III). They were selected because a high percentage of them had high right heart chamber pressure and/or lymphatic anomalies or inflammation and/or ulceration of the gastrointestinal mucosa. A double study method was performed, including excretion of fecal alpha-1-antitrypsin and intestinal clearance of alpha-1-antitrypsin. A high correlation between both methods (r = 0.7542, p < 0.001) was found. Normal values were obtained for the excretion of fecal alpha-1-antitrypsin (< 1.6 mg/g of dry feces) and for clearance (< 26.5 ml/day) in group I. Protein-losing enteropathy was diagnosed in 60% of cardiac patients and 35% of patients with gastrointestinal disease when applying the method of fecal alpha-1-antitrypsin excretion and in 50% and 40%, respectively, when using the clearance method. There is a high correlation between the clearance and plasma protein level (r = -0.7162, p < 0.001 for albumin, r = -0.5239, p < 0.01 for transferrin, r = -0.4609, p < 0.05 for prealbumin). The regression line crosses the albumin concentration of 3 g/dl when the clearance is 176 ml/day, a similar result to that seen in adult patients. Protein-losing enteropathy is detected in a high proportion of pediatric patients affected by cardiac or gastrointestinal disease. There is a close correlation between fecal excretion and intestinal clearance of alpha-1-antitrypsin.

Ecosystems and Global Change in the Context of the Neotropics; Medellín, Colombia, 19-20 May 2010; Research in most areas of global environmental change is overwhelmingly produced outside developing countries, which are usually consumers rather than producers of the knowledge associated with their natural resources. While there have been important recent advances in understanding the causes of global-¬scale changes and their consequences to the functioning of tropical ecosystems, there is still an important gap in the understanding of these changes at regional and national levels (where important political decisions are usually made). A symposium was held with the aim of surveying the current state of research activities in a small, developing country such as Colombia. It was jointly organized by the Research Center on Ecosystems and Global Change, Carbono and Bosques; the National University of Colombia at Medellín and the Colombian Ministry of the Environment, Housing, and Regional Development. This 2-¬day symposium gathered Colombian and international scientists involved in different areas of global environmental change, tropical ecosystems, and human societies.

A descriptive review of 12 patients who underwent appendicocecostomy or caecostomy for antegrade colonic lavage from January 2002 to February 2008. There were 9 appendicocecostomies performed patients from 3 to 13 years suffering from myelomeningocele, of which 8 of them had a very good outcome, with one case withdrawn due to poor use by the family. Three caecostomies were performed in non-mentally retarded constipated children. One was an otherwise healthy 7 year-old boy with hard stools since he was 10 months old, in spite of multiple laxative treatments, with normal morphology and function. He had a percutaneous caecostomy five years ago, with some improvement and a good quality of life, but still some occasional partial impactions. Another healthy 12 year-old boy with daily constipation associated faecal incontinence since he was 3 years old (normal manometry and rectal biopsy with signs of mild neuronal dysplasia) had a percutaneous caecostomy performed three years ago, with im...

Accelerated release of carbon from soils is one of the most important possible feedbacks related to anthropogenically induced climate change. Analyses studying the mechanisms for soil carbon release through decomposition have focused on the effect of changes in the average temperature, with little attention to changes in temperature variability. Anthropogenic activities are likely to modify both the average state and the variability of the climatic system; therefore, the effects of future warming on decomposition should not only focus on trends in the average temperature, but also variability expressed as a change of the probability distribution of temperature. Using analytical and numerical analyses we tested common relationships between temperature and respiration and found that the variability of temperature plays an important role determining respiration rates of soil organic matter. Changes in temperature variability, without changes in the average temperature, can either increase or decrease the amount of carbon released through respiration over the long-term. Furthermore, simultaneous changes in the average and variance of temperature can either amplify or dampen the sensitivity of soil organic matter to temperature. A potential consequence of this effect of variability would be lower respiration in places where the average temperature is expected to increase but its variance decreases.

To investigate the relationship between bone mineral density (BMD), age, sex, anthropometric measurements, dietary calcium intake and daily physical activity, in prepubertal children with distal forearm fracture (DFF). 160 children (80 males, 80 females) 3-10 years of age with DFF; control group of 160 children (age-sex matched) were studied. Age, sex, weight, height, tricipital skin fold thickness (TS), body mass index, daily calcium intake, and level of physical activity (extra-school physical exercise: low <1hour/day, high >1hour/day) registered. BMD assessed by peripheral DXA densitometer. Most fractures were caused by mild-moderate precipitating trauma by accidental fall (85.6%), with radius fracture in most cases (87.5%). BMI was higher in patients (19.14 kg/m(2)+/-3.50 vs. 17.46 kg/m(2)+/-2.67; p<0.0001). TS thickness was similar in both groups (20.28 mm+/-8.24 vs. 19.61 mm+/-6.60; p>0.05). Physical activity was lower in study group (extra-school physical activity...

Serological markers are of great interest in coeliac disease (CD), although intestinal biopsy is still the gold standard for establishing the diagnosis. Tissue transglutaminase IgA antibodies (AATGt-IgA) and antiendomysial antibodies IgA (AAE-IgA) are closely correlated to intestinal damage observed in biopsies. Villous atrophy (Marsh 3) plays a major role in CD diagnosis. Marsh 2 stage (crypt hyperplasia) as a CD marker is still under debate. To ascertain an AATGt-IgA level that corresponds to a positive predictive value (PPV) of 100% for a histological CD diagnosis. A series of 120 patients younger than 14 years, non- IgA deficient, who underwent an intestinal biopsy and were positive for both serological markers (AATGt-IgA and AAE-IgA). For AATGt-IgA, according to the manufacturer's recommendations, a value greater than 16 IU/mL is considered as a positive value. The PPV of AATGt was determined for different cut-off points. The histological findings distribution is directly c...

There are not many studies published in the literature on failure of medical treatment in Ulcerative Colitis (UC) that leads to colectomy. Retrospective study of patients under 14 years diagnosed with UC from 1984 to 2009, who underwent colectomy due to lack of response to medical treatment. They are divided into urgent or elective surgery. Colectomy performed in 14 paediatric patients (26.9% of total UC patients). Age at diagnosis 7.8±4.0 years, 8 of them younger than 10 years and 5 younger than 5 years. All cases diagnosed on patients less than 5 years of age required colectomy in the first 6 months after diagnosis. Elective colectomy was performed on 5/14 and urgent surgery in 9/14. The reported complications were divided into early (first 30 days after colectomy) and late. Pharmacological treatment in cases with urgent colectomy included methylprednisolone (100%), oral tacrolimus (55.5%), oral/intravenous cyclosporine (33.3%) and infliximab (33.3%). Cases of elective colectomy w...

Progressive familial intrahepatic cholestasis (PFIC) is a heterogeneous group of autosomic-recessive inherited cholestatic disorders that begin in the neonatal period or in the first years of life. There are three types of PFIC defined by different mutations located in the gene responsible for the bile flow through the intrahepatic canalicular transporter system. These disorders usually present in children or young adults and the main clinical manifestations are cholestasis, jaundice and pruritus, and they progress slowly towards liver fibrosis in adult life. PFIC diagnosis is based on clinical suspicion, biochemical findings (that include normal gamma-glutamyl transpeptidase in type 1 and 2, but increased levels in type 3), image techniques that rule-out other disorders, and histological confirmation. Initial treatment consists of symptomatic relief of cholestatic symptoms with choleretic agents (urso-deoxycholic acid). Partial biliary derivation and ileal bypass are intermediate therapeutic options. In case of no response to these treatments, liver transplantation is indicated. We report the case of a neonate with PFIC type 2 presenting as a liver failure.

The primary nutritional therapy (PNT), which consists in the administration of exclusive enteral formula feeds (polymeric, semi-elemental or elemental formula) for a period of no less than 6-8 weeks, has proven to be effective in inducing clinical remission in children with Crohn's disease. The clinical remission does not always include histological remission or cure of the mucosa. Faecal calprotectin is closely correlated with endoscopic and histological findings but is slightly associated with clinical activity scores. An observational prospective study including all patients under 14 years of age diagnosed with Crohn's disease between January 2002 and October 2007, and who were fed exclusively with polymeric formula (Modulen IBD, Nestle, Vevey, Switzerland) during the onset of the disease. Clinical controls were carried out (weight, height, body mass index [BMI) and the Paediatric Crohn's Disease Activity Index [PCDAI)) and faecal calprotectin was measured at the begi...

Crohn's disease (CD) is an intestinal inflammatory disease of unknown origin that is sometimes associated with cutaneous manifestations. These skin lesions are usually nonspecific (erythema nodosum, erythema multiforme and pyoderma gangrenosum) and should be differentiated from the cutaneous lesions corresponding to the typical histological pattern of CD; most of these extend directly from the involved bowel. Noncaseating granulomatous infiltration in skin anatomically distant from areas of gastrointestinal CD and separated by normal skin is extremely rare. This entity, known as metastatic Crohn's disease, can be the first symptom of CD or even more unusually can appear during the course of the disease.We report the case of a 9-year-old boy, previously diagnosed with ileocolic and perianal CD, who had been receiving treatment with mesalazine, prednisone and 6-mercaptopurine for 3 years. He presented with swelling of the penis and scrotum of 2 weeks' evolution, without an...

In the last years, few methods for the assessment of myocardial viability have been developed. Now a days the gold standard test for this purpose is the Positron Emission Tomography (PET). Recently, the expansion of Cardiovascular Magnetic Resonance imaging (MRI) has promoted the research for indexes or scores than can predict myocardial viability; so far, the late enhancement has proved to be one of the most accurate scores. The purpose of this study is to establish a correlation between the information of PET with the results of MRI in the assessment of myocardial viability. Late enhancement patterns and segmental mobility were compared. Sensitivity, specificity and positive and negative predictive values were calculated. SPSS v. 10 program was used for the statistic analysis. 17 patients with diagnosis of myocardial infarction were enrolled. All of them underwent into a myocardial viability detection PET study and into a cardiovascular magnetic resonance study using a late enhanc...

A complete evaluation of the patient with ischemic heart disease requires an anatomical and functional assessment of the myocardium and coronary arteries. Recent technological advances have allowed a quantitative and physiological evaluation of the cardiovascular system with Positron Emission Tomography (PET). This method is a valuable tool for the assessment of heart metabolism, myocardial perfusion, ventricular function, coronary blood flow, myocardial viability and endothelial function. One of the major limitations of a PET study is its low spatial resolution. Cardiac Computed Tomography (CCT) is an anatomic study used for coronary calcium quantification, evaluation of wall and lumen of coronary arteries, study of vascular permeability and assessment of composition, extension and severity of atherosclerotic plaques. The main limitation of CCT is the lack of functional information that is obtained with this technique. Both methods are complementary in many ways. That is the reason...

Background Coeliac disease (CD) is an enteropathy that affects about 0, 5-1% of the population. Even though it could be associated to diabetes, thyroiditis and Sjögren syndrome, there is not conclusive studies about its juvenile idiopathic arthritis (JIA) ...