16 results on '"León, Juan"'
Search Results
2. Infections in the first year after heart transplantation in a Latin American country.
- Author
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Carrillo‐Gómez, Diana Cristina, Rojas‐Perdomo, Cristhian Camilo, Orozco‐Echeverri, Nicolás, Montes, Maria C., Flórez‐Elvira, Liliana, López‐Pónce de León, Juan David, Olaya‐Rojas, Pastor, Flórez‐Alarcón, Noel, and Gómez‐Mesa, Juan Esteban
- Subjects
HEART transplantation ,HEART transplant recipients ,HEART failure ,BACTERIAL diseases ,HEART failure patients ,MEDICAL records - Abstract
Background: Heart transplantation is the therapy of choice in patients with advanced heart failure refractory to other medical or surgical management. However, heart transplants are associated with complications that increase posttransplant morbidity and mortality. Infections are one of the most important complications after this procedure. Therefore, infections in the first year after heart transplantation were evaluated. Methods: A retrospective cohort study of infections after heart transplants was conducted in a teaching hospital in Colombia between 2011 and 2019. Patients registered in the institutional heart transplant database (RETRAC) were included in the study. Microbiological isolates and infectious serological data were matched with the identities of heart transplant recipients and data from clinical records of individuals registered in the RETRAC were analyzed. The cumulative incidences of events according to the type of microorganism isolated were estimated using Kaplan–Meier survival analyses. Results: Seventy‐nine patients were included in the study. Median age was 49 years (37.4–56.3), and 26.58% of patients were women. Eighty‐seven infections were documented, of which 55.17% (48) were bacterial, 22.99% (20) were viral, and 12.64% (11) were fungal. Bacterial infections predominated in the first month. In the first year, infections caused 38.96% of hospital admissions and were the second cause of death after heart transplants (25.0%). Conclusion: Posttransplant infections in the first year of follow‐up were frequent. Bacterial infections predominated in the early posttransplant period. Infections, mainly bacterial, were the second most common cause of death and the most common cause of hospitalization in the first year after heart transplantation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
3. Clinical Characteristics and Outcomes of Patients with Heart Failure of Hypertensive Etiology: Analysis of Colombian Heart Failure Registry (RECOLFACA).
- Author
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Martínez-Carreño, Erika, Echeverría, Luis Eduardo, Rivera-Toquica, Alex, Zarama-Márquez, Mario Hernán, Ramírez-Puentes, Elkin Giovanni, Bustamante, Rafael Ignacio, Palacio, Rolando, Ávila-Barros, Luis Manuel, Campbell-Quintero, Sebastián, Morales-Rodríguez, Lisbeth Natalia, López-Ponce de León, Juan David, Buitrago, Andrés Felipe, Sandoval-Luna, Jorge Alberto, Saldarriaga, Clara, and Gómez-Mesa, Juan Esteban
- Subjects
HEART failure ,HEART failure patients ,ETIOLOGY of diseases ,CHRONIC obstructive pulmonary disease ,TYPE 2 diabetes ,PROPORTIONAL hazards models - Abstract
Introduction: Arterial hypertension represents one of the main comorbidities observed in patients with heart failure (HF) and one of the main risk factors for its development. Despite this, studies assessing this hypertensive etiology are scarce in Latin America. Our objective was to analyze the prevalence of HF of hypertensive etiology and evaluate its prognosis in patients enrolled in the Colombian Heart Failure Registry (RECOLFACA by its Spanish acronym). Methods: RECOLFACA recruited adult patients diagnosed with HF in 60 centers in Colombia between 2017 and 2019. The primary outcome was all-cause mortality. A Cox proportional hazards regression model was used to assess factors associated with primary outcomes in patients with hypertensive HF. A p value <0.05 was considered significant. All statistical tests were two-tailed. Results: Out of the total number of patients evaluated in RECOLFACA (n = 2,514), 804 had a diagnosis of HF with hypertensive etiology (31.9%). These patients were less frequently males and had a significantly older age and lower prevalence of comorbidities than those with HF of other etiologies. Additionally, patients with hypertensive HF had a higher prevalence of HF with preserved ejection fraction (HFpEF) (34.1% vs. 28.3%; p = 0.004). Finally, type 2 diabetes mellitus, chronic obstructive pulmonary disease diagnosis, and NYHA class IV were classified as independent mortality risk factors. Conclusions: Hypertensive HF represents about one-third of the total number of patients with HF in RECOLFACA. Compared with HF of other etiologies, it presents a differential clinical profile – older age and a higher prevalence of HFpEF. RECOLFACA has become a useful tool to characterize patients with HF in Colombia, with which it has been possible to carry out a more specific search and reach the diagnosis of this pathology in our population, and it has served as an example to stimulate registries of patients with HF in other countries in the region. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
4. Registro colombiano de trasplante cardíaco: año 1985-2021.
- Author
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Gómez-Mesa, Juan E., Uribe-Buriticá, Francisco L., Galindo-Coral, Stephania, Flórez, Noel A., Olaya-Rojas, Pastor, Carrillo-Gómez, Diana C., López-Ponce-de León, Juan D., Quintero-Ossa, Álvaro M., Echeverría-Correa, Luis E., Mendoza-Beltrán, Fernán, Mariño-Correa, Alejandro, Rodríguez-González, María J., Arias-Barrera, Carlos A., Plata-Mosquera, Carlos A., Echeverri-Navarrete, Eduardo J., and Senior-Sánchez, Juan M.
- Subjects
HEART transplantation - Abstract
Copyright of Revista Colombiana de Cardiología is the property of Publicidad Permanyer SLU and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2023
- Full Text
- View/download PDF
5. Cronología del trasplante cardíaco: más de tres décadas de historia (1985-2021).
- Author
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Gómez-Mesa, Juan E., Uribe-Buriticá, Francisco L., Galindo-Coral, Stephania, Flórez-Alarcón, Noel A., Olaya-Rojas, Pastor, Carrillo-Gómez, Diana C., López-Ponce de León, Juan D., Quintero- Ossa, Álvaro M., Echeverría-Correa, Luis E., Mendoza-Beltrán, Fernán del C., Mariño-Correa, Alejandro, Juliana Rodríguez-González, Ma., Arias-Barrera, Carlos A., Plata-Mosquera, Carlos A., Echeverri-Navarrete, Eduardo J., and Senior-Sánchez, Juan M.
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HEART transplantation ,CARDIOVASCULAR diseases risk factors ,OPERATIVE surgery ,HEART diseases ,OVERALL survival ,CARDIOVASCULAR diseases ,HEART failure - Abstract
Copyright of Revista Colombiana de Cardiología is the property of Publicidad Permanyer SLU and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2023
- Full Text
- View/download PDF
6. Nutrient loss to erosion responds to rain characteristics under transformed landscapes in the Río Grande basin, Colombian Andes.
- Author
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Suescún, Diego, León, Juan Diego, Villegas, Juan Camilo, and Correa‐Londoño, Guillermo Antonio
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CLIMATE change ,RAINFALL ,EROSION ,SOIL erosion ,SOIL pollution - Abstract
The functioning of tropical montane ecosystems are key provider of environmental services. However, climate and land use change interactively affect the ecohydrological and biogeochemical processes that support the provision of such services. We evaluate the effect of land use/land coverand the seasonality and intensity of the rainfall on the ecological functions of erosion control and nutrient regulation in a gradient of human intervention in the Central Andes of Colombia. Our results show that soil erosion (kg/ha/year) was higher in the transitory crop (187.7), followed by the permanent crop (98.2), and much lower in the pasture (8.0) and native forest (7.2). Our results also indicate a differential effect of land use and rainfall seasonality on erosion and nutrient transport, both processes being significantly higher in crops and lower in forest, both for the wet and dry seasons. However, the relationships between erosion and rainfall intensity varied depending on the hydrological season (in the wet seasons, no linear model was significant, while in the dry seasons, linear models for maximum rainfall intensity were significant in both crops and in the oak forest, and linear models with mean intensity were significant for both types of crops). Nitrogen exhibited the highest rates of transport, which can have important implications for water and soil pollution. Nitrogen transport via erosion (g/ha/year) was consistent with erosion results, being higher in the transitory crop (399.9) and permanent crop (265.3) that in the oak forest (6.9) and pasture (6.8). These results indicate that converting forests affects the capacity of ecosystems to provide environmental services, which is further amplified by projections of climate change. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
7. Role of Litter Turnover in Soil Quality in Tropical Degraded Lands of Colombia.
- Author
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León, Juan D. and Osorio, Nelson W.
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PLANT litter ,SOIL quality ,LAND use ,SOIL management ,SOIL productivity ,ENVIRONMENTAL soil science - Abstract
Land degradation is the result of soil mismanagement that reduces soil productivity and environmental services. An alternative to improve degraded soils through reactivation of biogeochemical nutrient cycles (via litter production and decomposition) is the establishment of active restoration models using new forestry plantations, agroforestry, and silvopastoral systems. On the other hand, passive models of restoration consist of promoting natural successional processes with native plants. The objective in this review is to discuss the role of litter production and decomposition as a key strategy to reactivate biogeochemical nutrient cycles and thus improve soil quality in degraded land of the tropics. For this purpose the results of different projects of land restoration in Colombia are presented based on the dynamics of litter production, nutrient content, and decomposition.The results indicate that in only 6-13 years it is possible to detect soil properties improvements due to litter fall and decomposition. Despite that, low soil nutrient availability, particularly of N and P, seems to be major constraint to reclamation of these fragile ecosystems. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
8. Ciclos biogeoquímicos en bosques naturales y plantaciones de coníferas en ecosistemas de alta montaña de Colombia.
- Author
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León, Juan Diego, González, María Isabel, and Gallardo, Juan Fernando
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PLANTATIONS , *CONIFERS , *MOUNTAINS , *PLANT litter decomposition , *FOREST ecology , *PINUS patula - Abstract
Plant litter production and decomposition are two important processes in forest ecosystems, since they provide the main organic matter input to soil and regulate nutrient cycling. With the aim to study these processes, litterfall, standing litter and nutrient return were studied for three years in an oak forest (Quercus humboldtii), pine (Pinus patula) and cypress (Cupressus lusitanica) plantations, located in highlands of the Central Cordillera of Colombia. Evaluation methods included: fine litter collection at fortnightly intervals using litter traps; the litter layer samples at the end of each sampling year and chemical analyses of both litterfall and standing litter. Fine litter fall observed was similar in oak forest (7.5Mg ha/y) and in pine (7.8Mg ha/y), but very low in cypress (3.5Mg ha/y). Litter standing was 1.76, 1.73 and 1.3Mg ha/y in oak, pine and cypress, respectively. The mean residence time of the standing litter was of 3.3 years for cypress, 2.1 years for pine and 1.8 years for oak forests. In contrast, the total amount of retained elements (N, P, S, Ca, Mg, K, Cu, Fe, Mn and Zn) in the standing litter was higher in pine (115kg/ha), followed by oak (78kg/ha) and cypress (24kg/ha). Oak forests showed the lowest mean residence time of nutrients and the highest nutrients return to the soil as a consequence of a faster decomposition. Thus, a higher nutrient supply to soils from oaks than from tree plantations, seems to be an ecological advantage for recovering and maintaining the main ecosystem functioning features, which needs to be taken into account in restoration programs in this highly degraded Andean mountains. [ABSTRACT FROM AUTHOR]
- Published
- 2011
9. Resultados de tratamiento para cáncer infantil en una población de recursos limitados en Bogotá, Colombia.
- Author
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Buendía-Hernández, Amparo, Loboguerrero-Compagnoli, José, and Lozano-León, Juan Manuel
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CHILDHOOD cancer ,TREATMENT effectiveness ,CANCER chemotherapy ,HEMATOLOGISTS ,ANTINEOPLASTIC agents ,MEDICAL quality control - Published
- 2010
10. Estructura y composición florística de tres robledales en la región norte de la cordillera central de Colombia.
- Author
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León, Juan D., Vélez, Gladys, and Yepes, Adriana P.
- Subjects
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ENDANGERED species , *WILDLIFE conservation , *ECOLOGY , *FORESTS & forestry - Abstract
Andean ecosystems harbor a high floristic diversity, which is being threatened by human disturbances such us deforestation and by the expansion of the agricultural frontier. One of these ecosystems are the Andean oak forests dominated by Quercus humboldtii, a threatened species in Colombia. We assessed the floristic composition and structure of three Andean oak forests located in three localities (San Andrés de Cuerquia, Belmira and Guarne) of Antioquia. The main goal was to determine whether these forests showed similarities in their structure and floristic composition. In each site, a permanent plot of 5000 m² (0.5 ha) was established. All trees with D ≥ 10 cm were sampled and identified to species. The Importance Value Index (IVI) was calculated as the sum of relative density (DeR), dominance (DoR) and frequency (FR) of a species. Trees with 5 ≤ D < 10 cm and 2 ≤ D < 5 cm were registered in sub-plots of 0.05 and 0.0144 ha, respectively. Finally, we used Jaccard's Index to quantify the floristic similarity among oak forest. When we considered all trees with D≥= 10 cm in the three forests, the number of species ranged from 18 to 54, whilst the number of individuals ranged from 326 to 680. The Guarne oak forest showed the highest species richness. In all sites, Q. humboldtii (Fagaceae) was the most important species in relation to the IVI, while Clusia sp. (Clusiaceae) and Myrsine coriaceae (Myrsinaceae) were the most important species in San Andrés de Cuerquia, Clethra fagifolia (Clethraceae) was important only in Belmira and Myrcia popayanensis (Myrtaceae) was important in Guarne. The families with the highest number of species were Fabaceae, Melastomataceae and Rubiaceae. Floristic similarity among places was low. The size distribution of trees had an inverse J-shape curve for all sites with changes in the abundance for size class. The three oak forests differed in their structure and floristic composition probably because of different disturbance degrees. Rev. Biol. Trop. 57 (4): 1165-1182. Epub 2009 December 01. [ABSTRACT FROM AUTHOR]
- Published
- 2009
11. Diabetes mellitus in patients with heart failure and effect modification of risk factors for short-term mortality: An observational study from the Registro Colombiano de Falla Cardíaca (RECOLFACA).
- Author
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Echeverría LE, Saldarriaga C, Campbell-Quintero S, Morales-Rodríguez LN, López-Ponce de León JD, Buitrago AF, Martínez-Carreño E, Sandoval-Luna JA, Llamas A, Moreno-Silgado GA, Vanegas-Eljach J, Murillo-Benítez NE, Gómez-Paláu R, Rivera-Toquica AA, Gómez-Mesa JE, and Research Group R
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- Humans, Colombia epidemiology, Male, Female, Aged, Middle Aged, Risk Factors, Registries, Proportional Hazards Models, Heart Failure mortality, Heart Failure complications, Heart Failure epidemiology, Diabetes Mellitus, Type 2 complications
- Abstract
Introduction: Heart failure and type 2 diabetes mellitus are critical public health issues., Objective: To characterize the risk factors for mortality in patients with heart failure and type 2 diabetes mellitus from a large registry in Colombia and to evaluate the potential effect modifications by type 2 diabetes mellitus over other risk factors., Materials and Methods: Heart failure patients with and without type 2 diabetes mellitus enrolled in the Registro Colombiano de Falla Cardíaca (RECOLFACA) were included. RECOLFACA enrolled adult patients with heart failure diagnosis from 60 medical centers in Colombia during 2017-2019. The primary outcome was all-cause mortality. Survival analysis was performed using adjusted Cox proportional hazard models., Results: A total of 2514 patients were included, and the prevalence of type 2 diabetes mellitus was 24.7% (n = 620). We found seven independent predictors of short-term mortality for the general cohort, chronic obstructive pulmonary disease, sinus rhythm, triple therapy, nitrates use, statins use, anemia, and hyperkalemia. In the type 2 diabetes mellitus group, only the left ventricle diastolic diameter was an independent mortality predictor (HR = 0.96; 95% CI: 0.93-0.98). There was no evidence of effect modification by type 2 diabetes mellitus on the relationship between any independent predictors and all-cause mortality. However, a significant effect modification by type 2 diabetes mellitus between smoking and mortality was observed., Conclusions: Patients with type 2 diabetes mellitus had higher mortality risk. Our results also suggest that type 2 diabetes mellitus diagnosis does not modify the effect of the independent risk factors for mortality in heart failure evaluated. However, type 2 diabetes mellitus significantly modify the risk relation between mortality and smoking in patients with heart failure.
- Published
- 2024
- Full Text
- View/download PDF
12. Characterization of Patients With Heart Failure of Chagas Etiology in Colombia: An Analysis Based on the Colombian Registry of Heart Failure (RECOLFACA).
- Author
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Echeverría LE, Saldarriaga C, Rivera-Toquica AA, Gómez-Ochoa SA, Cadena-Bonfanti AJ, Zarama-Márquez MH, Ramírez-Puentes EG, Bustamante RI, Palacio R, Ávila-Barros LM, Campbell-Quintero S, Morales-Rodríguez LN, López-Ponce de León JD, Buitrago AF, Martínez-Carreño E, and Gómez-Mesa JE
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- Adult, Humans, Colombia epidemiology, Prognosis, Registries, Stroke Volume, Heart Failure epidemiology, Heart Failure etiology, Heart Failure diagnosis, Cardiomyopathies complications, Chagas Cardiomyopathy epidemiology
- Abstract
Chronic Chagas cardiomyopathy (CCM) represents a relevant origin of Heart Failure (HF) in countries where the disease is endemic. CCM exhibits distinct myocardial involvement and is associated with a poorer prognosis compared to different HF etiologies. The aim is to explain the features and prognosis of individuals with HF resultant to CCM registered in the Colombian Registry of Heart Failure (RECOLFACA). RECOLFACA registry enrolled 2528 adult patients with HF. A comparison was made between patients diagnosed with CCM and those diagnosed with other etiologies of HF. Eighty-eight patients (3.5%) present CCM diagnosis. The individuals diagnosed with both HF and CCM were notably younger in age, had less comorbidities, poorer functional class, and significantly inferior ejection fraction. Finally, the presence of CCM diagnosis was linked to a substantially elevated mortality risk throughout the follow-up period (HR 2.01; 95% CI, 1.01-4.00) according to a multivariate model adjusted. CCM represents an important etiology of HF in Colombia, drawing attention to a distinct clinical profile and a higher risk of mortality compared to other HF etiologies., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
13. Prevalence, Clinical Characteristics, and Prognostic Impact of Kidney Disease on Heart Failure Patients: An Observational Study of the Colombian Heart Failure Registry.
- Author
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López-Ponce de León JD, Gómez-Mesa JE, Saldarriaga C, Echeverría LE, Posada-Bastidas A, García JC, Ochoa-Morón AD, Rolong B, Manzur-Jatin F, Mosquera-Jiménez JI, Pacheco-Jiménez OA, Rodríguez-Cerón ÁH, Rodríguez-Gómez P, Rivera-Toquica F, and Rivera-Toquica A
- Subjects
- Male, Adult, Humans, Prognosis, Colombia epidemiology, Prevalence, Renal Insufficiency, Chronic complications, Renal Insufficiency, Chronic epidemiology, Heart Failure complications, Heart Failure epidemiology, Heart Failure diagnosis
- Abstract
Introduction: Chronic kidney disease (CKD) represents one of the most frequent comorbidities observed in heart failure (HF) patients and has been observed to increase this population's risk of adverse outcomes. Nevertheless, evidence analyzing kidney dysfunction in HF is scarce in Latin American populations. We aimed to analyze the prevalence of kidney dysfunction and assess its association with mortality in patients diagnosed with HF enrolled in the Colombian Heart Failure Registry (RECOLFACA)., Methods: RECOLFACA enrolled adult patients with HF diagnosis from 60 centers in Colombia during the period 2017-2019. The primary outcome was all-cause mortality. A Cox proportional-hazards regression model was used to assess the impact of the different categories of eGFR in mortality risk. A p value of <0.05 was considered significant. All statistical tests were two-tailed., Results: From the total 2,514 evaluated patients, 1,501 (59.7%) patients had moderate kidney dysfunction (eGFR <60 mL/min/1.73 m2), while 221 (8.8%) patients were classified as having a severe kidney dysfunction (eGFR <30 mL/min/1.73 m2). Patients with lower kidney function were most commonly males, had higher median age, and reported a higher prevalence of cardiovascular comorbidities. Moreover, different patterns of medications prescription were observed when comparing CKD versus non-CKD patients. Finally, eGFR <30 mL/min/1.73 m2 was significantly associated with a higher mortality risk compared to eGFR >90 mL/min/1.73 m2 status (HR: 1.87; 95% CI, 1.10-3.18), even after an extensive adjustment by relevant covariates., Conclusion: CKD represents a prevalent condition in the setting of HF. Patients with CKD and HF present with multiple sociodemographic, clinical, and laboratory differences compared with those only diagnosed with HF and present a significantly higher risk of mortality. A timely diagnosis and optimal treatment and follow-up of CKD in the setting of HF may improve the prognosis of these patients and prevent adverse outcomes., (© 2023 The Author(s). Published by S. Karger AG, Basel.)
- Published
- 2023
- Full Text
- View/download PDF
14. First report of myiasis in dogs caused by Cochliomyia hominivorax (Coquerel 1858) in Colombia.
- Author
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Muñoz AAF, Caceres AFB, and León JCP
- Subjects
- Animals, Calliphoridae growth & development, Colombia, Debridement veterinary, Dogs, Larva physiology, Male, Screw Worm Infection diagnosis, Screw Worm Infection parasitology, Screw Worm Infection therapy, Treatment Outcome, Calliphoridae physiology, Dog Diseases diagnosis, Dog Diseases parasitology, Dog Diseases therapy, Screw Worm Infection veterinary
- Abstract
This paper reports for the first time in Colombia, two myasis cases caused by Cochliomyia hominivorax in stray dogs. Clinical examination of both patients revealed fever and a large wound at the palpebral level on the right side, and multiple perforating wounds in the right posterior limb where larvae were found. The treatment applied was the manual removal of larvae in the dogs, and subsequent eye enucleation in one dog due to the total loss of the upper right eyelid and the severe mechanical damage that the cornea received. Treatment was reinforced with repellents applied around the wounds and antibiotics. This finding of Cochliomyia hominivorax in stray dogs in Colombia raises concerns about the potential of dogs serving as a reservoir for human infection in the region., Competing Interests: Declaration of Competing Interest None., (Copyright © 2019 Elsevier B.V. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
15. [Biogeochemical cycles in natural forest and conifer plantations in the high mountains of Colombia].
- Author
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León JD, González MI, and Gallardo JF
- Subjects
- Altitude, Colombia, Ecosystem, Biodegradation, Environmental, Pinus metabolism, Plant Leaves metabolism, Soil chemistry, Tracheophyta metabolism, Trees metabolism
- Abstract
Plant litter production and decomposition are two important processes in forest ecosystems, since they provide the main organic matter input to soil and regulate nutrient cycling. With the aim to study these processes, litterfall, standing litter and nutrient return were studied for three years in an oak forest (Quercus humboldtii), pine (Pinus patula) and cypress (Cupressus lusitanica) plantations, located in highlands of the Central Cordillera of Colombia. Evaluation methods included: fine litter collection at fortnightly intervals using litter traps; the litter layer samples at the end of each sampling year and chemical analyses of both litterfall and standing litter. Fine litter fall observed was similar in oak forest (7.5 Mg ha/y) and in pine (7.8 Mg ha/y), but very low in cypress (3.5 Mg ha/y). Litter standing was 1.76, 1.73 and 1.3 Mg ha/y in oak, pine and cypress, respectively. The mean residence time of the standing litter was of 3.3 years for cypress, 2.1 years for pine and 1.8 years for oak forests. In contrast, the total amount of retained elements (N, P, S, Ca, Mg, K, Cu, Fe, Mn and Zn) in the standing litter was higher in pine (115 kg/ha), followed by oak (78 kg/ha) and cypress (24 kg/ha). Oak forests showed the lowest mean residence time of nutrients and the highest nutrients return to the soil as a consequence of a faster decomposition. Thus, a higher nutrient supply to soils from oaks than from tree plantations, seems to be an ecological advantage for recovering and maintaining the main ecosystem functioning features, which needs to be taken into account in restoration programs in this highly degraded Andean mountains.
- Published
- 2011
16. [Structure and floristic composition of three oak forests in the northern region of the Central Cordillera in Colombia].
- Author
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León JD, Vélez G, and Yepes AP
- Subjects
- Colombia, Population Density, Quercus classification, Trees classification
- Abstract
Andean ecosystems harbor a high floristic diversity, which is being threatened by human disturbances such us deforestation and by the expansion of the agricultural frontier. One of these ecosystems are the Andean oak forests dominated by Quercus humboldtii, a threatened species in Colombia. We assessed the floristic composition and structure of three Andean oak forests located in three localities (San Andrés de Cuerquia, Belmira and Guarne) of Antioquia. The main goal was to determine whether these forests showed similarities in their structure and floristic composition. In each site, a permanent plot of 5000 m2 (0.5 ha) was established. All trees with D > or = 10 cm were sampled and identified to species. The Importance Value Index (IVI) was calculated as the sum of relative density (DeR), dominance (DoR) and frequency (FR) of a species. Trees with 5 < or = D < 10 cm and 2 < or = D < 5 cm were registered in sub-plots of 0.05 and 0.0144 ha, respectively. Finally, we used Jaccard's Index to quantify the floristic similarity among oak forest. When we considered all trees with D > or = 10 cm in the three forests, the number of species ranged from 18 to 54, whilst the number of individuals ranged from 326 to 680. The Guarne oak forest showed the highest species richness. In all sites, Q. humboldtii (Fagaceae) was the most important species in relation to the IVI, while Clusia sp. (Clusiaceae) and Myrsine coriaceae (Myrsinaceae) were the most important species in San Andrés de Cuerquia, Clethra fagifolia (Clethraceae) was important only in Belmira and Myrcia popayanensis (Myrtaceae) was important in Guarne. The families with the highest number of species were Fabaceae, Melastomataceae and Rubiaceae. Floristic similarity among places was low. The size distribution of trees had an inverse J-shape curve for all sites with changes in the abundance for size class. The three oak forests differed in their structure and floristic composition probably because of different disturbance degrees.
- Published
- 2009
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