Dinámica del carbono en suelos de un ecosistema forestal fragmentado y evaluación de indicadores ambientales de cambio

"El suelo es el depósito de carbono más activo de los ecosistemas, pues en él se encuentra un gran reservorio que se ha ido incorporando a través del tiempo mediante la fotosíntesis y mineralización, procesos que forman parte de su ciclo global. Sin embargo, debido al manejo inadecuado del suelo en la agricultura, éste va perdiendo sus propiedades, de tal forma que el carbono almacenado durante años se libera a la atmósfera en forma de CO2 y CH4, sumándose a los demás gases de efecto invernadero y contribuyendo al calentamiento global. La perturbación del suelo genera desequilibrios ecológicos alterando los ciclos biogeoquímicos y contribuyendo a la pérdida de biodiversidad a pequeña y gran escala. Por esta razón es que la conservación de bosques y vegetación natural, además del buen manejo de las actividades en la agricultura, son esenciales para contribuir con el restablecimiento del suelo como sumidero de carbono, y factor esencial para mitigar el calentamiento global al devolver el equilibrio a los ecosistemas con la regeneración del ciclo de carbono. Por esta razón, nuestro objetivo es evaluar la dinámica del carbono en los suelos de las áreas donde la fragmentación del ecosistema forestal permita identificar indicadores ambientales de cambio"

The SNP at −592 of human IL-10 gene is associated with serum IL-10 levels and increased risk for human papillomavirus cervical lesion development

BACKGROUND: Women with Human Papilloma Virus (HPV) persistence are characterized by high levels of IL-10 at cervix. We have determined whether polymorphisms of IL-10 gene promoter might be associated with increased risk of squamous intraepithelial cervical lesions (SICL) and whether exist significative differences of IL-10 mRNA expression at cervix and systemic and serum IL-10 protein between SICL cases and non-Cervical Lesions (NCL). METHODS: Peripheral blood samples from SICL (n = 204) and NCL (n = 166) were used to detect IL-10 promoter polymorphisms at loci -592A/C (rs1800872), -819C/T (rs1800871), -1082A/G (rs1800896), -1352A/G (rs1800893), by allelic discrimination and to evaluate serum IL-10 protein. Cervical epithelial scrapings from NCL and biopsies from SICLs were used for HPV-typing and to evaluate IL-10 mRNA expression level. The systemic and local IL-10 mRNA expression levels were measured by real time-PCR. Genotypic and allelic frequencies of the selected polymorphisms were analyzed by logistic regression, adjusting by age and HPV-genotype, to determine the association with SICL. RESULTS: No significant differences were found between genotype frequencies at loci −819, -1082, and −1352. Individuals carrying at least one copy of risk allele A of polymorphism −592 had a two-fold increased risk of developing SICL [adjusted odds ratio (OR), 2.02 (95% CI, 1.26-3.25), p = 0.003], compared to NCL. The IL-10 mRNA expression and serum IL-10 protein, were significantly higher in SICL cases (p < 0.01), being higher in patients carrying the risk allele A. CONCLUSIONS: The −592 polymorphism is associated with increased risk of SICL and can serve as a marker of genetic susceptibility to SICL among Mexican women. According to IL-10 levels found in SICL, IL-10 can be relevant factor for viral persistence and progression disease

Depredación de semillas de euphorbia tehuacana por vertebrados en una zona semiárida del centro de México

“La depredación post-dispersión de semillas juega un papel importante en la dinámica poblacional de las plantas, limitando la regeneración natural y afectando la composición y estructura de las comunidades y poblaciones. En zonas áridas y semiáridas, las hormigas, aves y roedores son los principales depredadores de semillas. Tanto las características de las semillas, como el sitio determinan la importancia relativa de cada uno de estos grupos de granívoros. Dado los efectos demográficos negativos de la depredación de semillas es importante estimar la depredación de semillas para las especies con distribución restringida, pues sus poblaciones con frecuencia están en riesgo de extinción, y conocer los factores que determinan su abundancia es crucial para establecer planes de conservación de sus poblaciones. Euphorbia tehuacana es una especie endémica del Valle de Tehuacán, Puebla, cuya población más importante se encuentra en los alrededores de esta ciudad. Con un experimento de campo, evalué la intensidad de depredación de semillas de Euphorbia tehuacana por vertebrados diurnos y nocturnos en dos sitios que difieren en su composición vegetal. Al mismo tiempo cuantifiqué la abundancia de semillas en el suelo, viendo su relación con la pedregosidad. Finalmente se observó el consumo de semillas de E. tehuacana por parte de roedores”

Engineered expression system in K. phaffii for expression of human alpha-glucosidases, their characterization and inhibition

This thesis describes a progression of experiments that lead from the design of a new cloning-expression vector for K. phaffii, to the successful expression of numerous human alpha-glucosidases, their characterization and inhibition with three novel compounds derived from castanospermine. K. phaffii was chosen for its numerous advantages for the expression of foreign proteins. A convenient expression vector was engineered to provide extra benefits to the system, such as a simplified construct preparation, double selection marker, and efficient purification. All these improvements, together with an optimization of the expression protocols, resulted in a yield of expression for human recombinant alpha-glucosidases in a range of 0.79 mg/L to 3mg/L in batch production, along with a significant reduction in the cloning time and a suitable selection method to identify the cells with higher number of copies of the plasmid. A collection of eight alpha-glucosidases was successfully cloned and expressed using this system. All of them showed enzymatic activity and the expected size according to their amino acid sequences and expected pattern of glycosylation. These products were used to test three castanospermine analogues, which addressed the effect of different orientation of the substituent groups and size of the side chain on selectivity among N- and C- terminal subunits of sucrase-isomaltase. This research project opens the door to future investigation not only on the expression and structure/function analysis of alpha-glucosidases, but also as a good alternative for recombinant expression of other proteins

Depredación de semillas de euphorbia tehuacana por vertebrados en una zona semiárida del centro de México

“La depredación post-dispersión de semillas juega un papel importante en la dinámica poblacional de las plantas, limitando la regeneración natural y afectando la composición y estructura de las comunidades y poblaciones. En zonas áridas y semiáridas, las hormigas, aves y roedores son los principales depredadores de semillas. Tanto las características de las semillas, como el sitio determinan la importancia relativa de cada uno de estos grupos de granívoros. Dado los efectos demográficos negativos de la depredación de semillas es importante estimar la depredación de semillas para las especies con distribución restringida, pues sus poblaciones con frecuencia están en riesgo de extinción, y conocer los factores que determinan su abundancia es crucial para establecer planes de conservación de sus poblaciones. Euphorbia tehuacana es una especie endémica del Valle de Tehuacán, Puebla, cuya población más importante se encuentra en los alrededores de esta ciudad. Con un experimento de campo, evalué la intensidad de depredación de semillas de Euphorbia tehuacana por vertebrados diurnos y nocturnos en dos sitios que difieren en su composición vegetal. Al mismo tiempo cuantifiqué la abundancia de semillas en el suelo, viendo su relación con la pedregosidad. Finalmente se observó el consumo de semillas de E. tehuacana por parte de roedores”

Atypical presentation of sunflower epilepsy featuring an EEG pattern of continuous spike waves during slow-wave sleep

Sunflower epilepsy is a rare photosensitive and commonly pharmacoresistant reflex epilepsy characterized by stereotyped seizures involving turning of the head towards light, similar to a sunflower turning towards the sun, and waving of the hands in front of the eyes, sometimes followed by absence seizures, myoclonic jerks, and tonic-clonic seizures. In the original description, seizures in sunflower epilepsy have been perceived as self-induced, but contemporary case series suggest that hand waving corresponds to an ictal phenomenon and not to a precipitating factor. We describe a nine-year-old girl featuring absence seizures with eye rolling or fluttering associated with hand waving movements. The chronological sequence of events based on a video-EEG-documented episode of our patient adds to the controversy surrounding the hypothesis of "self-induced" epileptic seizures in sunflower epilepsy. Shortly after epilepsy diagnosis, our patient presented with an EEG pattern of continuous spike waves in slow-wave sleep, an EEG feature that has not been described before and may relate to the cognitive deficit observed in some patients with sunflower epilepsy. Continuous spike waves in slow-wave sleep resolved, and lasting seizure freedom was achieved by a combination of ethosuximide and lamotrigine, which may be a possible alternative to valproic acid, particularly in girls and women of childbearing age. However, an attempt to taper anti-seizure drugs two years later led to seizure recurrence. We suggest performing sleep EEG recordings for sunflower epilepsy, particularly in patients with developmental stagnation or regression, to timely diagnose and treat continuous spike waves in slow-wave sleep syndrome

Botulinum Toxin Type A for the Treatment of Equinus Deformity in to Patients With Mucopolysaccharidosis Type II

Mucopolysaccharidoses are lysosomal storage disorders that are caused by a deficiency in the enzymes that degrade glycosaminoglycans. The accumulation of glycosaminoglycans affects multiple systems, resulting in coarse facial features, short stature, organomegaly, and variable neurological changes from normal intelligence to severe mental retardation and spasticity. Effects on the musculoskeletal system include dysostosis multiplex, joint stiffness, and muscle shortening. This article reports 2 patients with mucopolysaccharidosis type II (Hunter syndrome) who showed progressive equinus deformity of the feet. Both patients were treated with intramuscular botulinum toxin type A injections in the gastrocnemius and the soleus muscles, followed by serial casting. In both patients, passive range of motion, muscle tone, and gait performance were significantly improved. Botulinum toxin type A injections followed by serial casting are a therapeutic option for contractures in patients with mucopolysaccharidosis. However, the long-term effects and the effect of application in other muscles remain unknown

How to Detect Isolated PEX10-Related Cerebellar Ataxia?

A 4-year-old boy presented with subacute onset of cerebellar ataxia. Neuroimaging revealed cerebellar atrophy. Metabolic screening tests aiming to detect potentially treatable ataxias showed an increased value (fourfold upper limit of normal) for phytanic acid and elevated very-long-chain fatty acid (VLCFA) ratios (C24:0/C22:0 and C26:0/C22:0), while absolute concentrations of VLCFA were normal. Genetic analysis identified biallelic variants in PEX10. Immunohistochemistry confirmed pathogenicity in the patients' cultured fibroblasts demonstrating peroxisomal mosaicism with a general catalase import deficiency as well as conspicuous peroxisome morphology as an expression of impaired peroxisomal function. We describe for the first time an elongated peroxisome morphology in a patient with PEX10-related cerebellar ataxia.A literature search yielded 14 similar patients from nine families with PEX10-related cerebellar ataxia, most of them presenting their first symptoms between 3 and 8 years of age. In 11/14 patients, the first and main symptom was cerebellar ataxia; in three patients, it was sensorineural hearing impairment. Finally, all 14 patients developed ataxia. Polyneuropathy (9/14) and cognitive impairment (9/14) were common associated findings. In 12/13 patients brain MRI showed cerebellar atrophy. Phytanic acid was elevated in 8/12 patients, while absolute concentrations of VLCFA levels were in normal limits in several patients. VLCFA ratios (C24:0/C22:0 and/or C26:0/C22:0), though, were elevated in 11/11 cases. We suggest including measurement of phytanic acid and VLCFA ratios in metabolic screening tests in unexplained autosomal recessive ataxias with cerebellar atrophy, especially when there is an early onset and symptoms are mild

The SNP at −592 of human IL-10 gene is associated with serum IL-10 levels and increased risk for human papillomavirus cervical lesion development

Abstract Background Women with Human Papilloma Virus (HPV) persistence are characterized by high levels of IL-10 at cervix. We have determined whether polymorphisms of IL-10 gene promoter might be associated with increased risk of squamous intraepithelial cervical lesions (SICL) and whether exist significative differences of IL-10 mRNA expression at cervix and systemic and serum IL-10 protein between SICL cases and non-Cervical Lesions (NCL). Methods Peripheral blood samples from SICL (n = 204) and NCL (n = 166) were used to detect IL-10 promoter polymorphisms at loci -592A/C (rs1800872), -819C/T (rs1800871), -1082A/G (rs1800896), -1352A/G (rs1800893), by allelic discrimination and to evaluate serum IL-10 protein. Cervical epithelial scrapings from NCL and biopsies from SICLs were used for HPV-typing and to evaluate IL-10 mRNA expression level. The systemic and local IL-10 mRNA expression levels were measured by real time-PCR. Genotypic and allelic frequencies of the selected polymorphisms were analyzed by logistic regression, adjusting by age and HPV-genotype, to determine the association with SICL. Results No significant differences were found between genotype frequencies at loci −819, -1082, and −1352. Individuals carrying at least one copy of risk allele A of polymorphism −592 had a two-fold increased risk of developing SICL [adjusted odds ratio (OR), 2.02 (95% CI, 1.26-3.25), p = 0.003], compared to NCL. The IL-10 mRNA expression and serum IL-10 protein, were significantly higher in SICL cases (p  Conclusions The −592 polymorphism is associated with increased risk of SICL and can serve as a marker of genetic susceptibility to SICL among Mexican women. According to IL-10 levels found in SICL, IL-10 can be relevant factor for viral persistence and progression disease.</p

Highly efficient ketone body treatment in multiple acyl-CoA dehydrogenase deficiency-related leukodystrophy.

BACKGROUND Multiple acyl-CoA dehydrogenase deficiency- (MADD-), also called glutaric aciduria type 2, associated leukodystrophy may be severe and progressive despite conventional treatment with protein- and fat-restricted diet, carnitine, riboflavin, and coenzyme Q10. Administration of ketone bodies was described as a promising adjunct, but has only been documented once. METHODS We describe a Portuguese boy of consanguineous parents who developed progressive muscle weakness at 2.5 y of age, followed by severe metabolic decompensation with hypoglycaemia and coma triggered by a viral infection. Magnetic resonance (MR) imaging showed diffuse leukodystrophy. MADD was diagnosed by biochemical and molecular analyses. Clinical deterioration continued despite conventional treatment. Enteral sodium D,L-3-hydroxybutyrate (NaHB) was progressively introduced and maintained at 600 mg/kg BW/d (≈3% caloric need). Follow up was 3 y and included regular clinical examinations, biochemical studies, and imaging. RESULTS During follow up, the initial GMFC-MLD (motor function classification system, 0 = normal, 6 = maximum impairment) level of 5-6 gradually improved to 1 after 5 mo. Social functioning and quality of life recovered remarkably. We found considerable improvement of MR imaging and spectroscopy during follow up, with a certain lag behind clinical recovery. There was some persistent residual developmental delay. CONCLUSION NaHB is a highly effective and safe treatment that needs further controlled studies