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The production of fermentable sugars from lignocellulosic biomass is achieved by the synergistic action of a group of enzymes called cellulases. Cellulose is a long chain of chemically linked glucoses by ß-1,4 bonds. The enzyme ß-1,4-endoglucanase is the first cellulase involved in the degradation, breaking the bond of the amorphous regions. A ß-1,4-endoglucanase enzyme with high activity was obtained from a Bacillus subtilis strain isolated from wastewater of a pulp and paper mill. Sequencing and bioinformatic analysis showed that the gene amplified by PCR consisting of 1407 nucleotides and coding for a ß-1,4-endoglucanase enzyme of approximately 55 kDa. The open reading frame (ORF) encoding the mature endoglucanase (eglS) was successfully inserted in a modified cloning plasmid (pITD03) and into the pYD1 plasmid used for its expression in yeast. Carboxymethylcellulose (CMC) plate assay, SDS-PAGE, and zymogram confirmed the production and secretion by the transformed E. coli BL21-SI strain of a 39 kDa ß-1,4-endoglucanase consistent with the catalytic domain without the cellulose-binding module (CBM). The results showed that the truncated ß-1,4-endoglucanase had higher activity and stability.
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Bacillus subtilis , Celulase , Papel , Proteínas Recombinantes , Águas Residuárias , Bacillus subtilis/genética , Bacillus subtilis/enzimologia , Bacillus subtilis/isolamento & purificação , Águas Residuárias/microbiologia , Águas Residuárias/química , Celulase/genética , Celulase/química , Celulase/biossíntese , Celulase/isolamento & purificação , Celulase/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas de Bactérias/genética , Proteínas de Bactérias/química , Proteínas de Bactérias/isolamento & purificação , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Clonagem Molecular , Expressão GênicaRESUMO
BACKGROUND AND OBJECTIVE: the use of 3D cameras for gait analysis has been highly questioned due to the low accuracy they have demonstrated in the past. The objective of the study presented in this paper is to improve the accuracy of the estimations made by robot-mounted 3D cameras in human gait analysis by applying a supervised learning stage. METHODS: the 3D camera was mounted in a mobile robot to obtain a longer walking distance. This study shows an improvement in detection of kinematic gait signals and gait descriptors by post-processing the raw estimations of the camera using artificial neural networks trained with the data obtained from a certified Vicon system. To achieve this, 37 healthy participants were recruited and data of 207 gait sequences were collected using an Orbbec Astra 3D camera. There are two basic possible approaches for training and both have been studied in order to see which one achieves a better result. The artificial neural network can be trained either to obtain more accurate kinematic gait signals or to improve the gait descriptors obtained after initial processing. The former seeks to improve the waveforms of kinematic gait signals by reducing the error and increasing the correlation with respect to the Vicon system. The second is a more direct approach, focusing on training the artificial neural networks using gait descriptors directly. RESULTS: the accuracy of the 3D camera to objectify human gait was measured before and after training. In both training approaches, a considerable improvement was observed. Kinematic gait signals showed lower errors and higher correlations with respect to the ground truth. The accuracy of the system to detect gait descriptors also showed a substantial improvement, mostly for kinematic descriptors rather than spatio-temporal. When comparing both training approaches, it was not possible to define which was the absolute best. CONCLUSIONS: supervised learning improves the accuracy of 3D cameras but the selection of the training approach will depend on the purpose of the study to be conducted. This study reveals the great potential of 3D cameras and encourages the research community to continue exploring their use in gait analysis.
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The aim was to determine the effect of Sechium edule var. nigrum spinosum (chayote) on gene expression related to antioxidant protection mechanisms and the inflammatory process in older adults with metabolic syndrome (MetS). A quasi-experimental study was carried out in a convenience sample of 46 older adults diagnosed with MetS: (i) placebo group (PG; n = 20); (ii) experimental group (EG; n = 26). The clinical, biochemical, anthropometric parameters and SOD, GPx, and CAT enzyme activity, alongside total oxidant status (TOS), total antioxidant status (TAS), oxidative stress index (OSI), cytokines (IL-6, IL-8 and TNF-α), and mRNA expression of SOD, GPx, CAT, IL-6, IL-8, TNF-α, Nrf2, NFkB p50, and NFkB p65, were measured at baseline and 6 months post-intervention. A statistically significant decrease was observed in TOS (baseline, 28.9 ± 3.6 vs. post, 23.7 ± 3.4, p < 0.01) and OSI (baseline, 24.1 ± 3.8 vs. post, 17.7 ± 4), as well as an increase in IL-6 (baseline, 10.7 ± 1.1 vs. post, 12.3 ± 2, p = 0.03), SOD activity (baseline, 167.1 ± 11.9 vs. post, 180.6 ± 7.6, p < 0.05), CAT activity (baseline, 1.0 ± 0.2 vs. post, 1.3 ± 0.2, p < 0.01), and TAS (baseline, 1.1 ± 0.1 vs. post, 1.4 ± 0.1, p < 0.01) in the EG compared to the PG. Regarding the expression of Nrf2, SOD, and IL-6, the EG showed a significant increase vs. basal levels (47%, 44%, and 43%, respectively). Our findings suggest that Sechium edule supplementation promotes the antioxidant response and decreases oxidative stress via Nrf2.
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Antioxidantes , Síndrome Metabólica , Humanos , Idoso , Antioxidantes/metabolismo , Síndrome Metabólica/tratamento farmacológico , Síndrome Metabólica/metabolismo , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Estresse Oxidativo , Superóxido Dismutase/metabolismo , Suplementos NutricionaisRESUMO
Human aging is a gradual and adaptive process characterized by a decrease in the homeostatic response, leading to biochemical and molecular changes that are driven by hallmarks of aging, such as oxidative stress (OxS), chronic inflammation, and telomere shortening. One of the diseases associated with the hallmarks of aging, which has a great impact on functionality and quality of life, is sarcopenia. However, the relationship between telomere length, sarcopenia, and age-related mortality has not been extensively studied. Moderate physical exercise has been shown to have a positive effect on sarcopenia, decreasing OxS and inflammation, and inducing protective effects on telomeric DNA. This results in decreased DNA strand breaks, reduced OxS and IA, and activation of repair pathways. Higher levels of physical activity are associated with an apparent increase in telomere length. This review aims to present the current state of the art of knowledge on the effect of physical exercise on telomeric maintenance and activation of repair mechanisms in sarcopenia.
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Limited strategies are available at disease progression on osimertinib for patients with EGFR-mutant NSCLC. The emergence of the on-target EGFR C797S mutation has been described as one of the most common mechanisms of resistance. In addition, loss of the EGFR T790M mutation has been mainly investigated as a resistance phenomenon to second-line osimertinib exposure. Remarkably, by studying the molecular profile at progression, it has been reported that the presence of the EGFR-sensitizing mutation, concurrently with the T790M, and C797S resulted in resistance to the current available EGFR tyrosine kinase inhibitors. Here, we report the first clinical evidence of gefitinib efficacy at EGFR exon 19 deletion/C797S mutation/T790M loss-mediated resistance to first-line osimertinib. Our findings highlight that dynamic genetic monitoring is a crucial approach in the evolution of EGFR-mutant NSCLC to understand the acquired molecular mechanisms for driving the best treatment strategy.
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The abandonment of traditional foods in the Mexican diet is one of the causes for the increase in diseases associated with obesity. Edible mushrooms have been a part of the Mexican diet since pre-Hispanic times. There is clear evidence that Pleurotus ostreatus (Po) contains bioactive compounds that have beneficial health effects. In the present study, we carried out a 3-month nutritional intervention in which we randomized 30 participants into two groups: one that consumed a healthy diet with regional foods without the inclusion of edible mushrooms (HD, n = 15) and one that consumed a healthy diet with regional foods alongside 1 kg of P. ostreatus (four portions of 250 g) per week (HD+ P. ostreatus, n = 15). We evaluated anthropometric measurements, lipid parameters, glucose levels, and blood pressure in inhabitants of San Miguel Tianguistenco, Puebla, a rural area of Mexico. For the HD group, the triglyceride levels decreased in women and the glucose levels decreased in men, and in the HD+ P. ostreatus group, visceral fat, glucose, triglyceride, and cholesterol levels decreased in women, and glucose and triglyceride levels decreased in men. Analysis of the intake of macro- and micronutrients in the community showed a high intake of energy, fat, and sugar, and a low intake of fiber, B complex vitamins, and minerals, indicators of an unbalanced diet. It is essential to create strategies that promote the inclusion of edible mushrooms as a part of a heathy diet in rural areas of Mexico to improve the actual health and nutrition of the residents.
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Agaricales , Hiperlipidemias , Ostreidae , Pleurotus , Animais , Suplementos Nutricionais , Feminino , Glucose , Humanos , Gordura Intra-Abdominal , Masculino , México , População Rural , TriglicerídeosRESUMO
ß-Glucosidase is part of the cellulases and is responsible for degrading cellobiose into glucose, a compound that can be used to produce biofuels. However, the use of the free enzyme makes the process more expensive. Enzyme immobilization improves catalytic characteristics and supports, such as zeolites, which have physical-chemical characteristics and ion exchange capacity that have a promising application in the biotechnological industry. This research aimed to immobilize by adsorption a recombinant ß-glucosidase from Trichoderma reesei, obtained in Escherichia coli BL21 (DE3), in a commercial zeolite. A Box Behnken statistical design was applied to find the optimal immobilization parameters, the stability against pH and temperature was determined, and the immobilized enzyme was characterized by SEM. The highest enzymatic activity was determined with 100 mg of zeolite at 35 °C and 175 min. Compared to the free enzyme, the immobilized recombinant ß-glucosidase presented greater activity from pH 2 to 4 and greater thermostability. The kinetic parameters were calculated, and a lower KM value was obtained for the immobilized enzyme compared to the free enzyme. The obtained immobilization parameters by a simple adsorption method and the significant operational stability indicate promising applications in different fields.
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Zeolitas , beta-Glucosidase , Estabilidade Enzimática , Enzimas Imobilizadas/química , Concentração de Íons de Hidrogênio , Hidrólise , Temperatura , beta-Glucosidase/metabolismoRESUMO
Sarcopenia is a syndrome that leads to physical disability and that deteriorates elderly people´s life quality. The etiology of sarcopenia is multifactorial, but mitochondrial dysfunction plays a paramount role in this pathology. Our research group has shown that the combined treatment of metformin (MTF) and exercise has beneficial effects for preventing muscle loss and fat accumulation, by modulating the redox state. To get an insight into the mechanism of the combined treatment, the mitochondrial bioenergetics was studied in the mitochondria isolated from old female Wistar rats quadriceps muscles. The animals were divided into six groups; three performed exercise on a treadmill for 5 days/week for 20 months, and the other three were sedentary. Also, two groups of each were treated with MTF for 6 or 12 months. The rats were euthanized at 24 months. The mitochondria were isolated and supercomplexes formation along with oxygen consumption, ATP synthesis, and ROS generation were evaluated. Our results showed that the combined treatment for 12 months increased the complex I and IV activities associated with the supercomplexes, simultaneously, ATP synthesis increased while ROS production decreased, indicating a tightly coupled mitochondria. The role of exercise plus the MTF treatment against sarcopenia in old muscles is discussed.
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Metformina , Sarcopenia , Trifosfato de Adenosina/metabolismo , Trifosfato de Adenosina/farmacologia , Idoso , Animais , Metabolismo Energético , Feminino , Humanos , Metformina/farmacologia , Metformina/uso terapêutico , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Músculo Esquelético/fisiologia , Músculo Quadríceps/patologia , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Espécies Reativas de Oxigênio/farmacologiaRESUMO
[This corrects the article DOI: 10.3389/fcimb.2018.00214.].
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Previous results using a movement defective alfalfa mosaic virus (AMV) vector revealed that citrus leprosis virus C (CiLV-C) movement protein (MP) generates a more efficient local movement, but not more systemic transport, than citrus leprosis virus C2 (CiLV-C2) MP, MPs belonging to two important viruses for the citrus industry. Here, competition experiment assays in transgenic tobacco plants (P12) between transcripts of AMV constructs expressing the cilevirus MPs, followed by several biological passages, showed the prevalence of the AMV construct carrying the CiLV-C2 MP. The analysis of AMV RNA 3 progeny recovered from P12 plant at the second viral passage revealed the presence of a mix of progeny encompassing the CiLV-C2 MP wild type (MPWT) and two variants carrying serines instead phenylalanines at positions 72 (MPS72F) or 259 (MPS259F), respectively. We evaluated the effects of each modified residue in virus replication, and cell-to-cell and long-distance movements. Results indicated that phenylalanine at position 259 favors viral cell-to-cell transport with an improvement in viral fitness, but has no effect on viral replication, whereas mutation at position 72 (MPS72F) has a penalty in the viral fitness. Our findings indicate that the prevalence of a viral population may be correlated with its greater efficiency in cell-to-cell and systemic movements.
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Citrus/virologia , Mutação , Proteínas do Movimento Viral em Plantas/genética , Vírus de Plantas/fisiologia , Vírus do Mosaico da Alfafa/genética , Movimento , Plantas Geneticamente Modificadas , Replicação ViralRESUMO
BACKGROUND: Abdominoplasties are increasingly requested aesthetic, reconstructive surgical procedures that, in most cases, have shown the disadvantage of leaving an often-notorious periumbilical scar due to hypertrophy, keloid, or because it simply remains very visible over time, after surgery. The Alvarez technique (or nonscarring minimal-incision neo-omphaloplasty) is a completely new, unprecedented technique because it does not leave visible scars. This technique requires the generation of four small flaps and a purse-string suture system interacting with the aponeurosis of the rectus abdominis muscles, as well as the modification of the vertical abdominal plication, and management of the subcutaneous cellular tissue in the new umbilicus area, which, if executed correctly, provide adequate aesthetic results. METHODS: A multicentric case-series scientific study is presented with a total of 94 patients who underwent classical abdominoplasties and neo-omphaloplasties with the aforementioned technique from August 2018 to December 2020. Pre-surgical and postoperative photographic files were collected. RESULTS: Of the 94 patients, there were eight (8.5%) cases of seroma, which are not attributable to neo-omphaloplasty but inherent to the use of drains. There were five (5.3%) cases of umbilical dehiscence. In total, 89.2% (84 patients) showed a very high degree of long-term satisfaction, and 10.6% (10 patients) had a medium level of long-term satisfaction. CONCLUSIONS: The Alvarez technique provides good aesthetic results that are well accepted among patients and surgeons, in the short and long term. It is useful for those patients who wish to undergo an abdominoplasty but cannot stand a scar in the umbilical region.
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The loss of skeletal muscle mass and strength is known as sarcopenia; it is characterized as a progressive and generalized muscle disorder associated with aging. This deterioration can seriously compromise the elderly's health and reduce their quality of life. In addition to age, there are other factors that induce muscle mass loss, among which are sedentary lifestyle, chronic diseases, inflammation, and obesity. In recent years, a new clinical condition has been observed in older adults that affects their physical capacities and quality of life, which is known as osteosarcopenic obesity (OSO). Osteoporosis, sarcopenia, and obesity coexist in this condition. Physical exercise and nutritional management are the most widely used interventions for the treatment and prevention of sarcopenia. However, in older adults, physical exercise and protein intake do not have the same outcomes observed in younger people. Here, we used a low-intensity exercise routine for a long period of time (LIERLT) in order to delay the OSO appearance related to sedentarism and aging in female Wistar rats. The LIERLT routine consisted of walking at 15 m/min for 30 min, five days a week for 20 months. To evaluate the effects of the LIERLT routine, body composition was determined using DXA-scan, additionally, biochemical parameters, inflammatory profile, oxidative protein damage, redox state, and serum concentration of GDF-11 at different ages were evaluated (4, 8, 12, 18, 22, and 24 months). Our results show that the LIERLT routine delays OSO phenotype in old 24-month-old rats, in a mechanism involving the decrease in the inflammatory state and oxidative stress. GDF-11 was evaluated as a protein related to muscle repair and regeneration; interestingly, rats that perform the LIERLT increased their GDF-11 levels.
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Fatores de Diferenciação de Crescimento/metabolismo , Inflamação/fisiopatologia , Osteoporose/prevenção & controle , Estresse Oxidativo/fisiologia , Condicionamento Físico Animal/métodos , Sarcopenia/prevenção & controle , Animais , Feminino , Ratos , Ratos WistarRESUMO
Osteosarcopenic obesity (OSO) is characterized by bone density, mass, and muscle strength loss, in conjunction with adipose tissue increase. OSO impairs physical activity and mobility, provoking autonomy loss; also, it is known that augmenting body fat in the elderly decreases life expectancy. The main factors influencing this health deterioration are the inflammatory environment induced by adipose tissue and its infiltration into muscle tissue, which leads to oxidative stress generation. Currently, there are several treatments to delay OSO, among which exercise training stands out because it improves muscle fiber quality and quantity and decreases adipose tissue. We have recently demonstrated that the combined treatment between moderate exercise and metformin slows sarcopenia's onset by a mechanism that includes adipose reduction and REDOX regulation. On the other hand, tert-butylhydroquinone (tBHQ) is a well-known antioxidant that counteracts oxidative stress. Therefore, to slow down obesity's harmful effects on muscle mass and bone mineral density, we performed different interventions, including combining a Fartlek-type exercise routine with metformin and tBHQ administration, in a model of middle-aged female Wistar rats with obesity induced with a hypercaloric diet. Our results showed that the combined exercise-metformin-tBHQ treatment increased muscle mass and strength, decreased body weight, body mass index, and fat percentage, and improved redox status, thus increasing animal survival.
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Doenças Ósseas Metabólicas/prevenção & controle , Hidroquinonas/farmacologia , Metformina/farmacologia , Obesidade/terapia , Condicionamento Físico Animal , Sarcopenia/prevenção & controle , Animais , Doenças Ósseas Metabólicas/etiologia , Feminino , Obesidade/complicações , Ratos , Sarcopenia/etiologiaRESUMO
Oxidative stress is known to be involved in the etiology of sarcopenia, a progressive loss of muscle mass and force related to elderly incapacity. A successful intervention to prevent this condition has been exercise-based therapy. Metformin (MTF), an anti-diabetic drug with pleiotropic effects, is known to retain redox homeostasis. However, the combined use of MTF with exercise has shown controversial experimental results. Our research group has shown that MTF-treatment does not limit the benefits provided by exercise, probably by inducing a hormetic response. Hence, our aim was to evaluate the effect of exercise in combination with MTF-treatment on the redox state of old female Wistar rats. Animals were divided into six groups; three groups preformed exercise on a treadmill for 5 days/week for 20 months and the other three were sedentary. Also, two groups of each, exercised and sedentary animals were treated with MTF for 6 or 12 months correspondingly, beside the untreated groups. Rats were euthanized at 24 months. Muscular functionality was analyzed as the relation between the lean mass free of bone with respect to the grip strength. Superoxide dismutase, catalase, and glutathione peroxidase content, enzymatic activity and redox state were determined in the gastrocnemius muscle. Our results showed that the exercised group treated with MTF for 12 months presented higher GSH/GSSG rate and high antioxidant scavenging power in contrast to the MTF-treatment for 6 months, where the beneficial effect was less noticeable.
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Antioxidantes/metabolismo , Metformina , Músculo Esquelético , Condicionamento Físico Animal , Animais , Catalase/metabolismo , Feminino , Glutationa Peroxidase/metabolismo , Metformina/farmacologia , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/enzimologia , Estresse Oxidativo , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismoRESUMO
The Deepwater Horizon (DWH) oil spill from April to July of 2010 contaminated Gulf of Mexico waters through release of an estimated 4.1â¯×â¯106 barrels of oil. Beginning in June of 2010, semipermeable membrane devices (SPMDs) were deployed near areas with sensitive marine habitats (Alabama Alps and Western Shelf) potentially exposed to that oil. Elevated TPAH50 concentrations, flux rates and similarity of histograms and diagnostic ratios for polycyclic aromatic hydrocarbons (PAH) from SPMDs to weathered floating oil collected during the DWH spill indicates the Alabama Alps habitats were affected. While not affected by oil from the DWH spill, the temporal pattern of PAH contamination of SPMDs deployed near the Western Shelf between July 2010 and March 2011 could indicate prevailing currents affected contaminant transport to the Western Shelf Area (East and West Flower Garden, Sonnier, and Stetson Banks) from non-DWH sources, including oil and gas exploration, shipping, and Mississippi River effluent.
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Monitoramento Ambiental/instrumentação , Poluição por Petróleo , Petróleo , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Alabama , Florida , Golfo do México , Hidrocarbonetos , MississippiRESUMO
Objetivo: determinar la prevalencia de la fisura labio alveolo palatina (FLAP) en las prin-cipales ciudades del Ecuador: Quito, Guayaquil y Cuenca, en el período comprendido desde el año 2010 al 2018. Metodos: se realizó un estudio descriptivo, observacional de corte transversal y retrospectivo mediante la revisión de la base de datos de estudios realizados en medios hospitalarios de las ciudades de Quito, Guayaquil y Cuenca en pacientes con diagnóstico de FLAP nacidos en el periodo comprendido desde el año 2010 al 2018. La información mediante un formulario para el nacido vivo con FLAP sindrómico, no sindrómico y de la madre. Resultados: se encontró que la frecuencia de FLAP es 14.97 por cada 10,000 nacidos vivos, dato concordante con el de los países de la región. Según registros hospitalarios del sistema nacional de salud, 1132 pacientes con diagnostico FLAP fueron atendidos en el periodo 2010 a 2018. Con respecto al de edad de los niños que requirieron atención por FLAP, este fue de 3 años (DS: ±3.2). Su proporción por sexo fue 38.19% en mujeres vs. 61.68% en hombres. Conclusión: hasta ahora no se han encontrado estudios en el Ecuador que cuenten con criterios unifi-cados sobre diagnóstico y clasificación de las FLAP, para así aportar a la formulación políticas de salud pública y al mejoramiento de la calidad de vida del paciente fisurado.
Objective: To determine the prevalence of the cleft lip and palate (CLAP) in the main cities of Ecuador: Quito, Guayaquil and Cuenca, in the period from 2010 to 2018. Methods: A descriptive, observational, cross-sectional and retrospective study was carried out by reviewing the database of studies conducted in hospital settings in the cities of Quito, Guayaquil and Cuenca of patients diagnosed with FLAP born in the period from 2010 to 2018. The information was collected using a form for the live birth with syndromic, non-syndromic and mother CLAP. Results: The frequency of CLAP was found to be 14.97 per 10,000 live births, consistent with that of the countries in the region. 1132 patients diagnosed with CLAP were treated in the national health system according to hospital records, in the period 2010 to 2018; Regarding the average age of children who required CLAP care, it was 3 years (SD: ± 3.2). Their sex ratio was 38.19% women vs. 61.68% men Conclusion: No studies have been found in Ecuador that have unified criteria on diagnosis and classification of CLAPs that help formulate public health policies that improve the quality of life of the cracked patient.
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Humanos , Prevalência , Equador , Sexo , Etnicidade , Registros Hospitalares , Fenda Labial , Fissura PalatinaRESUMO
Sarcopenia is a syndrome characterized by a progressive and generalized skeletal muscle mass and strength loss, as well as a poor physical performance, which as strongly been associated with aging. Sedentary lifestyle in the elderly contributes to this condition; however, physical activity improves health, reducing morbidity and mortality. Recent studies have shown that metformin (MTF) can also prevent muscle damage promoting muscular performance. To date, there is great controversy if MTF treatment combined with exercise training improves or nullifies the benefits provided by physical activity. This study is aimed at evaluating the effect of long-term moderate exercise combined with MTF treatment on body composition, strength, redox state, and survival rate during the life of female Wistar rats. In this study, rats performed moderate exercise during 20 of their 24 months of life and were treated with MTF for one year or for 6 months, i.e., from 12 to 24 months old and 18 to 24 months old. The body composition (percentage of fat, bone, and lean mass) was determined using a dual-energy X-ray absorption scanner (DXA), and grip strength was determined using a dynamometer. Likewise, medial and tibial nerve somatosensory evoked potentials were evaluated and the redox state was measured by HPLC, calculating the GSH/GSSG ratio in the gastrocnemius muscle. Our results suggest- that the MTF administration, both in the sedentary and the exercise groups, might activate a mechanism that is directly related to the induction of the hormetic response through the redox state modulation. MTF treatment does not eliminate the beneficial effects of exercise throughout life, and although MTF does not increase muscle mass, it increases longevity.
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Metformina/farmacologia , Força Muscular/efeitos dos fármacos , Condicionamento Físico Animal/métodos , Sarcopenia/prevenção & controle , Fatores Etários , Animais , Feminino , Humanos , Masculino , Força Muscular/fisiologia , Ratos , Ratos Wistar , Sarcopenia/patologiaRESUMO
The protozoan parasite Entamoeba histolytica is exposed to reactive oxygen and nitric oxide species that have the potential to damage its genome. E. histolytica harbors enzymes involved in DNA repair pathways like Base and Nucleotide Excision Repair. The majority of DNA repairs pathways converge in their final step in which a DNA ligase seals the DNA nicks. In contrast to other eukaryotes, the genome of E. histolytica encodes only one DNA ligase (EhDNAligI), suggesting that this ligase is involved in both DNA replication and DNA repair. Therefore, the aim of this work was to characterize EhDNAligI, its ligation fidelity and its ability to ligate opposite DNA mismatches and oxidative DNA lesions, and to study its expression changes and localization during and after recovery from UV and H2O2 treatment. We found that EhDNAligI is a high-fidelity DNA ligase on canonical substrates and is able to discriminate erroneous base-pairing opposite DNA lesions. EhDNAligI expression decreases after DNA damage induced by UV and H2O2 treatments, but it was upregulated during recovery time. Upon oxidative DNA damage, EhDNAligI relocates into the nucleus where it co-localizes with EhPCNA and the 8-oxoG adduct. The appearance and disappearance of 8-oxoG during and after both treatments suggest that DNA damaged was efficiently repaired because the mainly NER and BER components are expressed in this parasite and some of them were modulated after DNA insults. All these data disclose the relevance of EhDNAligI as a specialized and unique ligase in E. histolytica that may be involved in DNA repair of the 8-oxoG lesions.
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Dano ao DNA , DNA Ligases/metabolismo , Reparo do DNA , Entamoeba histolytica/enzimologiaRESUMO
Although freelisting and semi-structured interviews are widespread methods in ethnobotany, few studies quantitatively examine how these methods may bias results. Using a comprehensive ethnobotanical inventory of palm species, uses and names in the Chácobo tribe of Bolivia, we show that interviews elicit more items than freelists, but the effect is sensitive to sample size, item type and data categorization. This implies that even subtle methodological choices may greatly affect reported results.