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1.
Data Brief ; 50: 109610, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37808538

RESUMEN

This paper presents a semi-automated, scalable, and homologous methodology towards IoT implemented in Python for extracting and integrating images in pedestrian and motorcyclist areas on the road for constructing a multiclass object classifier. It consists of two stages. The first stage deals with creating a non-debugged data set by acquiring images related to the semantic context previously mentioned, using an embedded device connected 24/7 via Wi-Fi to a free and public CCTV service in Medellin, Colombia. Through artificial vision techniques, and automatically performs a comparative chronological analysis to download the images observed by 80 cameras that report data asynchronously. The second stage proposes two algorithms focused on debugging the previously obtained data set. The first one facilitates the user in labeling the data set not debugged through Regions of Interest (ROI) and hotkeys. It decomposes the information in the nth image of the data set in the same dictionary to store it in a binary Pickle file. The second one is nothing more than an observer of the classification performed by the user through the first algorithm to allow the user to verify if the information contained in the Pickle file built is correct.

2.
Yeast ; 39(3): 193-207, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34693568

RESUMEN

The antioxidant phenotype caused by resveratrol has been recognized as a key piece in the health benefits exerted by this phytochemical in diseases related to aging. It has recently been proposed that a mitochondrial pro-oxidant mechanism could be the cause of resveratrol antioxidant properties. In this regard, the hypothesis that resveratrol impedes electron transport to complex III of the electron transport chain as its main target suggests that resveratrol could increase reactive oxygen species (ROS) generation through reverse electron transport or by the semiquinones formation. This idea also explains that cells respond to resveratrol oxidative damage, inducing their antioxidant systems. Moreover, resveratrol pro-oxidant properties could accelerate the aging process, according to the free radical theory of aging, which postulates that organism's age due to the accumulation of the harmful effects of ROS in cells. Nonetheless, there is no evidence linking the chronological lifespan (CLS) shorten occasioned by resveratrol with a pro-oxidant mechanism. Hence, this study aimed to evaluate whether resveratrol shortens the CLS of Saccharomyces cerevisiae due to a pro-oxidant activity. Herein, we provide evidence that supplementation with 100 µM of resveratrol at 5% glucose: (1) shortened the CLS of ctt1Δ and yap1Δ strains; (2) decreased ROS levels and increased the catalase activity in WT strain; (3) maintained unaffected the ROS levels and did not change the catalase activity in ctt1Δ strain; and (4) lessened the exponential growth of ctt1Δ strain, which was restored with the adding of reduced glutathione. These results indicate that resveratrol decreases CLS by a pro-oxidant mechanism.


Asunto(s)
Longevidad , Saccharomyces cerevisiae , Antioxidantes/farmacología , Catalasa/metabolismo , Catalasa/farmacología , Glucosa/farmacología , Longevidad/genética , Estrés Oxidativo , Especies Reactivas de Oxígeno , Resveratrol/farmacología , Saccharomyces cerevisiae/genética
3.
Braz J Microbiol ; 52(3): 1247-1255, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34100260

RESUMEN

L-asparaginase II (ASNase) is the biopharmaceutical of choice for the treatment of acute lymphoblastic leukaemia. In this study, E. coli BL21 (DE3) transformed with the pET15b + asnB vector which expresses recombinant ASNase was used as a source to obtain this enzyme. The ideal conditions to produce ASNase would be a high level of secretion into the extracellular medium, which depends not only on the application of molecular biology techniques but also on the development of a strategy to modify cell permeability such as the addition of substances to the culture medium that stimulate destabilisation of structural components of the cell. Thus, the growth of E. coli BL21 (DE3) in modified Luria-Bertani broth, supplemented with 0.8% (w/v) glycine and 6% (v/v) n-dodecane, increased the total yield of ASNase by about 50% (15,108 IU L-1) and resulted in a 16-fold increase in extracellular enzymatic productivity (484 IU L-1 h-1), compared to production using the same medium without addition of these substances. Most of the enzyme (89%) was secreted into the culture medium 24 h after the induction step. This proposed approach presents a simple strategy to increase extracellular production of ASNase in E. coli.


Asunto(s)
Asparaginasa , Escherichia coli , Alcanos , Asparaginasa/biosíntesis , Medios de Cultivo , Escherichia coli/crecimiento & desarrollo , Escherichia coli/metabolismo , Glicina , Proteínas Recombinantes/biosíntesis
4.
Zootaxa ; 4896(3): zootaxa.4896.3.2, 2020 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-33756857

RESUMEN

We describe a new species of dendrobatid frog, Leucostethus bilsa sp. nov., using molecular, morphological, and acoustic evidence. We also comment on the taxonomic status of four similar Hyloxalus and Colostethus. We provide an updated phylogeny of Leucostethus that corroborates previous hypotheses of relationships of nine species. Phylogenetic analysis using mitochondrial (i.e., 7095 bp of combined data from NADH1, NAHD2, cytochrome c oxidase I, cytochrome b and 12S-16S rRNA) and seven nuclear genes (i.e., 4739 bp) indicate a close relationship of L. bilsa to an undescribed species from Gorgona Island, Colombia, both of which apparently diverged in the Pliocene about 3 million years ago with about 6.25% (i.e., 146/2335 bp) differences for the section of 12S-16S mitochondrial fragment. Leucostethus bilsa is diurnal and riparian, characterized by distinctive bright mustard-yellow flash marks in the axillar and groin regions, posterior belly, and in the hindlimbs, the presence of dark gray lower labial stripe or marks, sexual dimorphism in ventral pattern, and by having male uniparental care. We describe its osteology and the male advertisement call, which is a series of peep notes. Osteological microCT images of representatives of each of the Colostethinae genera reveal a number of intriguing characters that may prove to be useful in phylogenetic studies. In terms of its distribution, Leucostethus bilsa is currently known only from a very small area within the Reserva Biológica Bilsa, located within the Cordillera Mache-Chindul in the Chocoan region of northwestern Ecuador, which was a Pliocene-Pleistocene refugium. This region is highly threatened with habitat degradation and remains as the last surviving refuge for a forest community known for a high proportion of endemic species of both flora and fauna.


Asunto(s)
Anuros , Animales , Anuros/genética , Ecuador , Masculino , Filogenia , ARN Ribosómico 16S/genética
5.
Appl Biochem Biotechnol ; 190(3): 1060-1073, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31667755

RESUMEN

Microbial proteases are widely used as commercial enzymes, which have an active role in several industrial processes. The aim of this study was to investigate the production and properties of extracellular proteases from Barrientosiimonas sp. strain V9. The cultivation conditions for protease production were studied using different carbon and nitrogen sources. Maximum protease production was obtained in medium containing 25 g L-1 sucrose, 7 g L-1 KNO3, and initial pH 7.0 at 35 °C and 150 rpm during 72 h. Under these conditions, maximum proteolytic activity reached 1200 U mL-1. The enzyme extract showed optimum activity at 60 °C, pH 9.0, and was stable from 30 to 50 °C within a pH range from 4.0 to 10.0 and NaCl concentration up to 2.5 M. The enzyme was stable in the presence of EDTA, urea, Triton X-100 and laundry detergent (sodium lauryl sulfate as main component). The addition of 1% sodium dodecyl sulfate, Tween-80, or Tween-20 increased the activity by 183% and 119% respectively, while 2-mercaptoethanol reduced the activity to 71%. Casein zymogram analysis revealed three hydrolysis zones suggesting that Barrientosiimonas sp. V9 expresses proteases with molecular weights about 60, 45, and 35 kDa, which were inhibited in the presence of phenylmethylsulfonyl fluoride. Barrientosiimonas sp. V9 produces halotolerant serine proteases with great biotechnological potential.


Asunto(s)
Actinobacteria/enzimología , Extremófilos/enzimología , Péptido Hidrolasas/metabolismo , Medios de Cultivo , Estabilidad de Enzimas , Concentración de Iones de Hidrógeno , Péptido Hidrolasas/biosíntesis , Proteolisis , Temperatura
6.
Nanomaterials (Basel) ; 9(5)2019 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-31071952

RESUMEN

Although dibenzyl disulfide (DBDS) is used as a mineral oil stabilizer, its presence in electrical transformer oil is associated as one of the major causes of copper corrosion and subsequent formation of copper sulfide. In order to prevent these undesirable processes, MY zeolites (with M = Li, Na, K, Cs, Cu or Ag) are proposed to adsorb molecularly DBDS. In this study, different MY zeolites are investigated at the DFT+D level in order to assess their ability in DBDS adsorption. It was found that CsY, AgY and CuY exhibit the best compromise between high interaction energies and limited S-S bond activation, thus emerging as optimal adsorbents for DBDS.

7.
Prep Biochem Biotechnol ; 48(8): 707-717, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29995576

RESUMEN

The efficacy of a simple laboratory method for cell disruption based on the glass bead stirring, sonication, osmotic shock, freezing and grinding, or use of solvents and detergents was assessed in this study, via measurements of the release of total protein and L-asparaginase activity. Three different microbial sources of L-asparaginase were used: Escherichia coli BL21 (DE3), Leucosporidium muscorum, and Aspergillus terreus (CCT 7693). This study adjusted and identified the best procedure for each kind of microorganism. Sonication and glass bead stirring led to obtaining filamentous fungus cell-free extracts containing high concentrations of soluble proteins and specific activity; however, sonication was the best since it obtained 4.61 ± 0.12 IU mg-1 after 3 min of operation time. Mechanical methods were also the most effective for yeast cell disruption, but sonication was the technique which yielded a higher efficiency releasing 7.3 IUtotal compared to glass bead stirring releasing 2.7 IUtotal at the same operation time. For bacterium, sonication proved to be the best procedure due to getting the highest specific activity (9.01 IU mg-1) and total enzyme activity (61.7 IU). The data presented lead to conclude that the mechanical methods appeared to be the most effective for the disintegration of the all microbial cells studies. This is the first report related to the experimental comparison of L-ASNase extraction procedures from different microorganisms, which can also be used for extracting periplasm located enzymes from other organisms.


Asunto(s)
Asparaginasa/química , Aspergillus/enzimología , Basidiomycota/enzimología , Pared Celular/química , Proteínas de Escherichia coli/química , Escherichia coli/enzimología , Proteínas Fúngicas/química , Asparaginasa/aislamiento & purificación , Proteínas de Escherichia coli/aislamiento & purificación , Proteínas Fúngicas/aislamiento & purificación
8.
Dermatol. pediátr. latinoam. (En línea) ; 13(1): 20-23, abr. 2015. ilus
Artículo en Español | LILACS | ID: biblio-868852

RESUMEN

El xantogranuloma juvenil es una enfermedad benigna fibrohistiocítica poco frecuente, que forma parte del diverso grupo de desórdenes proliferativos histiocíticos de células no-Langerhans. Se presenta principalmente de forma congénita o antes del primer año de edad, aunque también se han descripto casos aislados en adultos.Presentamos cuatro pacientes sin antecedentes patológicos de importancia, que acudieron a la consulta externa por presentar lesiones papulosas asintomáticas, amarillo-anaranjadas, en las que se encontraron hallazgos dermatoscópicos e histopatológicos característicos de xantogranuloma juvenil.


Juvenile xanthogranulomais a rare, benign fibrohistiocytic disease that belongs to the wide group of non-Langerhans cell histiocytoses. It develops congenitally or before the first year of life; however there are few cases reported in adults.We present four patients with no significant medical history, who attended because of asymptomatic, yellowish-orange papularcutaneous lesions that were dermatoscopic and histopathologically consistent with juvenile xanthogranuloma.


Asunto(s)
Humanos , Embarazo , Recién Nacido , Lactante , Microscopía , Xantogranuloma Juvenil , Técnicas y Procedimientos Diagnósticos
9.
Phys Chem Chem Phys ; 14(47): 16326-30, 2012 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-23132234

RESUMEN

The potential energy surfaces of the Na(Si(5-n)(BH)(n))(-) and Si(5-n)(BH)(n)(2-) (n = 0-5) systems have been explored in detail. We established that all the global minimum structures of anionic and dianionic systems can be obtained by substitution of one or more silicon atoms of the global minima of NaSi(5)(-) and Si(5)(2-) for B-H units. The conservation of the overall structure upon isoelectronic substitution was shown to be due to the preservation of the chemical bonding pattern. Theoretical VDEs were calculated for all of the sodiated Na(Si(5-n)(BH)(n))(-) (n = 0-5) systems to facilitate their experimental detection.

10.
Medicina (B Aires) ; 67(1): 8-18, 2007.
Artículo en Español | MEDLINE | ID: mdl-17408015

RESUMEN

BACKGROUND: It has been established that first-degree relatives of patients with chronic kidney disease (CKD) have a higher CKD risk than the overall population. This paper deals with the relative frequency of CKD markers and cardiovascular (CV) risk factors within first-degree relatives of ESRD patients in Argentina. METHODS: 810 family members volunteered to participate; of them 668 over 18 ys. old. Trained nurses interviewed them and completed a questionnaire dealing with family history of renal and cardiovascular disease. Blood pressure, urine and blood analysis and anthropometric data were collected. Selected parameters were: smoking habit, presence of high blood pressure, diabetes, hypercholesterolemia, high plasma creatinine and creatinine clearance estimated by MDRD formula, proteinuria and microalbuminuria. In pediatric population, weight and blood pressure parameters were evaluated as percentiles. CKD were classified in stage (National Kidney Foundation). RESULTS: The relative frequencies were: CKD: 29.6%; proteinuria: 13.9%; microalbuminuria: 8.7%. The prevalence values found for main CV risks factors, adjusted by sex and age, were: high blood pressure= 41.8%; overweight/obesity by BMI= 62.1%, hypercholesterolemia= 42.9% and hyperglycemia= 5.2%. Smoking habit was present in 34.8%. IN CONCLUSION: Prevalence of overweight/obesity, hypertension and hypercholesterolemia in first-degree relatives of ESRD patients is higher than previously communicated in studies of national reference populations. Prevalence of CKD is high, estimated as three-fold higher than for a general population as reported in poblational studies. These results support the fact that first-degree relatives of ESRD patients, as has been established elsewhere, constitute a population at high risk for developing ESRD.


Asunto(s)
Salud de la Familia , Núcleo Familiar , Diálisis Renal , Insuficiencia Renal Crónica/genética , Adolescente , Adulto , Argentina/epidemiología , Biomarcadores/sangre , Niño , Preescolar , Creatinina/sangre , Estudios Transversales , Femenino , Tasa de Filtración Glomerular , Humanos , Hipertensión/epidemiología , Masculino , Tamizaje Masivo , Obesidad/epidemiología , Proteinuria/orina , Insuficiencia Renal Crónica/epidemiología , Factores de Riesgo , Fumar/efectos adversos
11.
Medicina (B.Aires) ; 67(1): 8-18, jan.-fev. 2007. tab, graf
Artículo en Español | BINACIS | ID: bin-123139

RESUMEN

En publicaciones previas se muestra que familiares con vínculo primario de pacientes con enfermedad renal crónica tienen mayor riesgo de desarrollar la enfermedad que la población general. Objetivo: conocer la frecuencia relativa de marcadores de enfermedad renal crónica y factores de riesgo cardiovascular entre familiares con vínculo primario de pacientes en diálisis. Material y métodos: se estudiaron 810 voluntarios, 668 mayores de 18 años. Se les realizó una encuesta sobre antecedentes de enfermedad renal y cardiovascular. Se midieron presión arterial y datos antropométricos, y se tomaron muestras para análisis de orina y sangre. Los parámetros valorados en la población adulta fueron: hábito de fumar, presencia de hipertensión arterial (HTA), obesidad, diabetes, hipercolesterolemia, creatininemia y clearance de creatinina estimado por MDRD, proteinuria y microalbuminuria por tira reactiva con lectura digital. En población pediátrica se consideraron los percentilos para peso y presión arterial. Se clasificó a la población por estadios de enfermedad renal crónica según recomendación de la National Kidney Foundation. Resultados: Frecuencias relativas de ERC= 29.6%; proteinuria = 13.9% y microalbuminuria= 8.7%. Las frecuencias relativas, ajustadas por sexo y edad, fueron: de HTA 41.8%, sobrepeso/obesidad 62.1%, e hipercolesterolemia 42.9%, y de hiperglucemia 5.2%. El 34.8% de los encuestados eran fumadores. En conclusión: En población adulta la prevalencia de sobrepeso/obesidad, hipertensión arterial e hipercolesterolemia entre familiares con vínculo primario de pacientes en TSR fue más elevada que las comunicadas en estudios poblaciones nacionales. La prevalencia de enfermedad renal crónica también fue elevada, estimándose en tres veces superior a la de la población general. Estos resultados apoyan el hecho que los familiares con vínculo primario de pacientes en diálisis constituyen una población de alto riesgo de enfermedad renal crónica. (AU)


Background: It has been established that first-degree relatives of patients with chronic kidney disease (CKD) have a higher CKD risk than the overall population. This paper deals with the relative frequency of CKD markers and cardiovascular (CV) risk factors within first-degree relatives of ESRD patients in Argentina. Methods: 810 family members volunteered to participate; of them 668 over 18 ys. old. Trained nurses interviewed them and completed a questionnaire dealing with family history of renal and cardiovascular disease. Blood pressure, urine and blood analysis and anthropometric data were collected. Selected parameters were: smoking habit, presence of high blood pressure, diabetes, hypercholesterolemia, high plasma creatinine and creatinine clearance estimated by MDRD formula, proteinuria and microalbuminuria. In pediatric population, weight and blood pressure parameters were evaluated as percentiles. CKD were classified in stage (National Kidney Foundation). Results: The relative frequencies were: CKD: 29.6%; proteinuria: 13.9%; microalbuminuria: 8.7%. The prevalence values found for main CV risks factors, adjusted by sex and age, were: high blood pressure= 41.8%; overweight/obesity by BMI= 62.1%, hypercholesterolemia= 42.9% and hyperglycemia= 5.2%. Smoking habit was present in 34.8%. In conclusion: Prevalence of overweight/obesity, hypertension and hypercholesterolemia in first-degree relatives of ESRD patients is higher than previously communicated in studies of national reference populations. Prevalence of CKD is high, estimated as three-fold higher than for a general population as reported in poblational studies. These results support the fact that first-degree relatives of ESRD patients, as has been established elsewhere, constitute a population at high risk for developing ESRD.(AU)


Asunto(s)
Humanos , Masculino , Femenino , Preescolar , Niño , Adolescente , Adulto , Insuficiencia Renal Crónica/epidemiología , Diálisis Renal , Núcleo Familiar , Salud de la Familia , Insuficiencia Renal Crónica/genética , Biomarcadores/sangre , Creatina/sangre , Hipertensión/epidemiología , Tabaquismo/efectos adversos , Obesidad/epidemiología , Tasa de Filtración Glomerular , Argentina/epidemiología , Proteinuria/orina , Estudios Transversales , Tamizaje Masivo , Factores de Riesgo
12.
Medicina (B.Aires) ; 67(1): 8-18, jan.-fev. 2007. tab, graf
Artículo en Español | LILACS | ID: lil-464738

RESUMEN

En publicaciones previas se muestra que familiares con vínculo primario de pacientes con enfermedad renal crónica tienen mayor riesgo de desarrollar la enfermedad que la población general. Objetivo: conocer la frecuencia relativa de marcadores de enfermedad renal crónica y factores de riesgo cardiovascular entre familiares con vínculo primario de pacientes en diálisis. Material y métodos: se estudiaron 810 voluntarios, 668 mayores de 18 años. Se les realizó una encuesta sobre antecedentes de enfermedad renal y cardiovascular. Se midieron presión arterial y datos antropométricos, y se tomaron muestras para análisis de orina y sangre. Los parámetros valorados en la población adulta fueron: hábito de fumar, presencia de hipertensión arterial (HTA), obesidad, diabetes, hipercolesterolemia, creatininemia y clearance de creatinina estimado por MDRD, proteinuria y microalbuminuria por tira reactiva con lectura digital. En población pediátrica se consideraron los percentilos para peso y presión arterial. Se clasificó a la población por estadios de enfermedad renal crónica según recomendación de la National Kidney Foundation. Resultados: Frecuencias relativas de ERC= 29.6%; proteinuria = 13.9% y microalbuminuria= 8.7%. Las frecuencias relativas, ajustadas por sexo y edad, fueron: de HTA 41.8%, sobrepeso/obesidad 62.1%, e hipercolesterolemia 42.9%, y de hiperglucemia 5.2%. El 34.8% de los encuestados eran fumadores. En conclusión: En población adulta la prevalencia de sobrepeso/obesidad, hipertensión arterial e hipercolesterolemia entre familiares con vínculo primario de pacientes en TSR fue más elevada que las comunicadas en estudios poblaciones nacionales. La prevalencia de enfermedad renal crónica también fue elevada, estimándose en tres veces superior a la de la población general. Estos resultados apoyan el hecho que los familiares con vínculo primario de pacientes en diálisis constituyen una población de alto riesgo de enfermedad renal crónica.


Background: It has been established that first-degree relatives of patients with chronic kidney disease (CKD) have a higher CKD risk than the overall population. This paper deals with the relative frequency of CKD markers and cardiovascular (CV) risk factors within first-degree relatives of ESRD patients in Argentina. Methods: 810 family members volunteered to participate; of them 668 over 18 ys. old. Trained nurses interviewed them and completed a questionnaire dealing with family history of renal and cardiovascular disease. Blood pressure, urine and blood analysis and anthropometric data were collected. Selected parameters were: smoking habit, presence of high blood pressure, diabetes, hypercholesterolemia, high plasma creatinine and creatinine clearance estimated by MDRD formula, proteinuria and microalbuminuria. In pediatric population, weight and blood pressure parameters were evaluated as percentiles. CKD were classified in stage (National Kidney Foundation). Results: The relative frequencies were: CKD: 29.6%; proteinuria: 13.9%; microalbuminuria: 8.7%. The prevalence values found for main CV risks factors, adjusted by sex and age, were: high blood pressure= 41.8%; overweight/obesity by BMI= 62.1%, hypercholesterolemia= 42.9% and hyperglycemia= 5.2%. Smoking habit was present in 34.8%. In conclusion: Prevalence of overweight/obesity, hypertension and hypercholesterolemia in first-degree relatives of ESRD patients is higher than previously communicated in studies of national reference populations. Prevalence of CKD is high, estimated as three-fold higher than for a general population as reported in poblational studies. These results support the fact that first-degree relatives of ESRD patients, as has been established elsewhere, constitute a population at high risk for developing ESRD.


Asunto(s)
Humanos , Masculino , Femenino , Preescolar , Niño , Adolescente , Adulto , Salud de la Familia , Núcleo Familiar , Diálisis Renal , Insuficiencia Renal Crónica/epidemiología , Argentina/epidemiología , Biomarcadores/sangre , Estudios Transversales , Creatina/sangre , Tasa de Filtración Glomerular , Hipertensión/epidemiología , Tamizaje Masivo , Obesidad/epidemiología , Proteinuria/orina , Factores de Riesgo , Insuficiencia Renal Crónica/genética , Fumar/efectos adversos
13.
Proc Natl Acad Sci U S A ; 100(22): 12792-7, 2003 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-14555763

RESUMEN

Aposematism is the association, in a prey organism, of the presence of a warning signal with unprofitability to predators. The origin of aposematism is puzzling, because of its predicted low probability of establishment in a population due to the prey's increased conspicuousness. Aposematism is a widespread trait in invertebrate taxa, but, in vertebrates, it is mostly evident in amphibians, reptiles, and fishes. Poison frogs (Dendrobatidae) are one of the most well known examples of the co-occurrence of warning coloration and toxicity. This monophyletic group of mostly diurnal leaf-litter Neotropical anurans has both toxic/colorful and palatable/cryptic species. Previous studies suggested a single origin of toxicity and warning coloration, dividing the family in two discrete groups of primitively cryptic and more derived aposematic frogs. Recent molecular phylogenetic analyses using mostly aposematic taxa supported this conclusion and proposed a single tandem origin of toxicity and conspicuous warning coloration. By using expanded taxon and character sampling, we reexamined the phylogenetic correlation between the origins of toxicity and warning coloration. At least four or five independent origins of aposematism have occurred within poison frogs; by using simulations, we rejected hypotheses of one, two, or three origins of aposematism (P < 0.002). We also found that diet specialization is linked with the evolution of aposematism. Specialization on prey, such as ants and termites, may have evolved independently at least two times.


Asunto(s)
Anuros/clasificación , Bufonidae/clasificación , Dieta , Filogenia , Ponzoñas/análisis , Animales , Evolución Molecular , Técnicas In Vitro , Modelos Biológicos , Datos de Secuencia Molecular , Especificidad de la Especie
14.
Cancer Genet Cytogenet ; 132(1): 65-7, 2002 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-11801312

RESUMEN

Different BCR-ABL transcript variants occur more or less frequently, according to the leukemia type. We report the frequencies of BCR-ABL transcript variants studied in chronic myeloid leukemia (CML) and acute lymphoblastic leukemia (ALL) patients in the Ecuadorian population. The frequencies found for CML patients in this study were 94.6% for the b2/a2 rearrangement and 5.4% for the b3/a2 rearrangement; whereas in ALL, all cases (100%) that presented the BCR-ABL rearrangement had the e1/a2 junction. Since our results differ from the frequencies previously reported, we suggest that this may be due to a different genetic background in the population involved in this study when compared to the populations analyzed in prior studies. Furthermore, we recommend a survey of the BCR-ABL transcript variants and their frequencies in different ethnic groups.


Asunto(s)
Proteínas de Fusión bcr-abl/genética , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Adolescente , Adulto , Anciano , Médula Ósea/patología , Niño , Preescolar , Ecuador/epidemiología , Femenino , Frecuencia de los Genes , Reordenamiento Génico , Genotipo , Humanos , Lactante , Recién Nacido , Cariotipificación , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
15.
Oncol. (Quito) ; 6(3): 221-6, jul.-sept. 1996.
Artículo en Español | LILACS | ID: lil-235307

RESUMEN

Desde que fue descubierto en 1983, helicobacter pylori ha sido implicado como agente causal en la fisiopatología de la enfermedad ulcerosa péptica y recientemente en las neoplasias de estómago llámense estas adenocarcinomas o linfomas. Mediante la producción de amoníaco y citoquinas el H Pylori logra adaptarse al bajo pH estomacal provocando una hipoclorhidria inicial que facilita su colonización y posteriormente una disfunción de la producción de ácido debido a la hipergastrinemia reactiva y a la disminución de la producción de somatostatina (hormona que inhibe la producción de ácido). Por lo menos en la úlcera péptica y en la gastritis crónica sean éstas superficiales, antrales, difusas, o crónicas multifocales, (siendo esta última la que mayor propensión tiene a desarrollar malignidad), la asoasociación con el H Pylori va del 60 al 100xciento, considerándose un factor importante de tipo ambiental e infeccioso en la etiología de estas lesiones premalignas...


Asunto(s)
Humanos , Helicobacter pylori , Heridas y Lesiones
17.
Oncol. (Quito) ; 5(1): 9-13, jul.-sept. 1995.
Artículo en Español | LILACS | ID: lil-235299

RESUMEN

Revisa brevemente los métodos de diganóstico morfológico del cáncer pulmonar y su clasificación histológica, poniendo énfasis en la relación del carcinoma de células pequeñas con otras neoplasias neuroendocrinas del pulmón...


Asunto(s)
Humanos , Adenocarcinoma , Carcinoma de Células Escamosas , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/patología
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