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The objective of this study was to assess the addition of whey protein hydrolysate (WH) on quality and antihypertensive potential of pork frankfurters, as the first step in development of a functional meat product. A hydrolyzed whey protein solution was incorporated in the frankfurter formula according to the following treatments: T0 (30% water), T1 (10% WH, 20% water), T2 (20% WH, 10% water) and T3 (30% WH). Addition of up to 30% WH increased lightness and yellowness, decreased hardness and chewiness by 15% and shear force by 43%, with no effect on pH (6.36) and cooking yield (93%). The WH addition resulted in an increase in the antihypertensive potential (IC50 258.78⯵g/mL) relative to the T0 (IC50 1548.25⯵g/mL). Cold storage of the product with 30% WH did not impact physicochemical quality, nor did it modify the antihypertensive potential. Incorporation of whey hydrolysate into pork frankfurters could be an option for providing antihypertensive peptides in food for health-oriented consumers.
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Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Productos de la Carne/análisis , Péptidos/farmacología , Proteína de Suero de Leche , Animales , Color , Almacenamiento de Alimentos , Alimentos Funcionales , Hidrolisados de Proteína , Resistencia al Corte , PorcinosRESUMEN
BACKGROUND: Malaria is endemic in Darién and an assessment of the different factors affecting its epidemiology is crucial for the development of adequate strategies of surveillance, prevention, and disease control. The objective of this study was to determine the main characteristics of the epidemiological behavior of malaria in the Darien region. METHODS: This research was comprised of a retrospective analysis to determine the incidence and malaria distribution in the Darien region from 2015 to 2017. We evaluated malaria indicators, disease distribution, incidence (by age group and sex), diagnostic methods, treatment, and control measures. In addition, we examined the cross-border migration activity and its possible contribution to the maintenance and distribution of malaria. RESULTS: During the period of 2015-2017, we examined 41,141 thick blood smear samples, out of which 501 tested positive for malaria. Plasmodium vivax was responsible for 92.2% of those infections. Males comprised 62.7% of the total diagnosed cases. Meanwhile, a similar percentage, 62.7%, of the total cases were registered in economically active ages. The more frequent symptoms included fever (99.4%) and chills (97.4%), with 53.1% of cases registering between 2,000 and 6,000 parasites/µl of blood. The annual parasitic incidence (API) average was 3.0/1,000 inhabitants, while the slide positivity rate (SPR) was 1.2% and the annual blood examination rate (ABER) 22.5%. In Darién there is a constant internal and cross-border migration movement between Panama and Colombia. Malaria control measures consisted of the active and passive search of suspected cases and of the application of vector control measures. CONCLUSION: This study provides an additional perspective on malaria epidemiology in Darién. Additional efforts are required to intensify malaria surveillance and to achieve an effective control, eventually moving closer to the objective of malaria elimination. At the same time, there is a need for more eco-epidemiological, entomological and migratory studies to determine how these factors contribute to the patterns of maintenance and dissemination of malaria.
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Enfermedades Endémicas/estadística & datos numéricos , Malaria Falciparum/epidemiología , Malaria Vivax/epidemiología , Plasmodium falciparum/aislamiento & purificación , Plasmodium vivax/aislamiento & purificación , Adolescente , Adulto , Anciano , Antimaláricos/uso terapéutico , Niño , Preescolar , Colombia , Femenino , Humanos , Incidencia , Lactante , Malaria Falciparum/sangre , Malaria Falciparum/tratamiento farmacológico , Malaria Falciparum/parasitología , Malaria Vivax/sangre , Malaria Vivax/tratamiento farmacológico , Malaria Vivax/parasitología , Masculino , Persona de Mediana Edad , Panamá/epidemiología , Estudios Retrospectivos , Factores Sexuales , Análisis Espacio-Temporal , Enfermedad Relacionada con los Viajes , Adulto JovenRESUMEN
In the past 5-10 years, Venezuela has faced a severe economic crisis, precipitated by political instability and declining oil revenue. Public health provision has been affected particularly. In this Review, we assess the impact of Venezuela's health-care crisis on vector-borne diseases, and the spillover into neighbouring countries. Between 2000 and 2015, Venezuela witnessed a 359% increase in malaria cases, followed by a 71% increase in 2017 (411â586 cases) compared with 2016 (240â613). Neighbouring countries, such as Brazil, have reported an escalating trend of imported malaria cases from Venezuela, from 1538 in 2014 to 3129 in 2017. In Venezuela, active Chagas disease transmission has been reported, with seroprevalence in children (<10 years), estimated to be as high as 12·5% in one community tested (n=64). Dengue incidence increased by more than four times between 1990 and 2016. The estimated incidence of chikungunya during its epidemic peak is 6975 cases per 100â000 people and that of Zika virus is 2057 cases per 100â000 people. The re-emergence of many vector-borne diseases represents a public health crisis in Venezuela and has the possibility of severely undermining regional disease elimination efforts. National, regional, and global authorities must take action to address these worsening epidemics and prevent their expansion beyond Venezuelan borders.
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Enfermedades Transmisibles Emergentes/epidemiología , Enfermedades Transmisibles Emergentes/transmisión , Epidemias , Enfermedades Transmitidas por Vectores/epidemiología , Enfermedades Transmitidas por Vectores/transmisión , Animales , Control de Enfermedades Transmisibles , Enfermedades Transmisibles Emergentes/prevención & control , Epidemias/prevención & control , Epidemias/estadística & datos numéricos , Geografía Médica , Humanos , Incidencia , Enfermedades Transmitidas por Vectores/prevención & control , Venezuela/epidemiologíaRESUMEN
Abalone is an extremely valuable food source derived from cultured and wild animals, the later from populations under intense fishing exploitation and of high conservation value. As part of a long-term study to characterize genes from abalone that can be used as markers for hybrids certification, we characterised 5S ribosomal DNA (5S rDNA) in red abalone (Haliotis rufescens) and blue abalone (H. fulgens). The 5S rDNA arrays occur to a single pair of metacentric chromosomes at interstitial positions in both species. Two types of 5S genes were found, named types I and II, each associated with different non-transcribed spacer (NTS) sequences. The structure of the 5S rRNA genes and the NTS indicate incomplete homogenisation of the 5S rDNA arrays. The divergence of the 5S genes between species provide polymorphisms which can be used to distinguish red from blue abalone in forensic analysis of commercial production.
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Evolución Molecular , Gastrópodos/genética , ARN Ribosómico 5S/genética , Animales , Cromosomas/genética , Genes de ARNr , Hibridación Fluorescente in SituRESUMEN
Resumen La ruptura del músculo papilar anterolateral es una complicación del síndrome coronario agudo poco frecuente, en especial porque este músculo usualmente tiene doble irrigación sanguínea al comparar con el músculo papilar posteromedial que, por lo general, solo tiene una irrigación. Se presenta el caso de un paciente que consultó por signos y síntomas de falla cardiaca aguda precedidos de dolor de pecho, en quien se documentó insuficiencia mitral grave por ruptura del músculo papilar anterolateral debido a enfermedad coronaria isquémica de múltiples vasos.
Abstract The rupture of the anterior-lateral papillary muscle is an uncommon complication of acute coronary syndrome. This is particularly relevant as this has double blood irrigation compared to that of the posteromedial papillary muscle that generally only has single irrigation. The case is presented on a patient that consulted due to having signs and symptoms of acute heart failure preceded by chest pains. Severe mitral insufficiency was observed due to a rupture of the anterior-lateral papillary muscle caused by a multiple vessel ischaemic coronary disease.
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Humanos , Femenino , Persona de Mediana Edad , Insuficiencia de la Válvula Mitral , Infarto del Miocardio , Cirugía General , EcocardiografíaRESUMEN
Trypanosoma cruzi chromosome ends are enriched in surface protein genes and pseudogenes (e.g., trans-sialidases) surrounded by repetitive sequences. It has been proposed that the extensive sequence variability among members of these protein families could play a role in parasite infectivity and evasion of host immune response. In previous reports we showed evidence suggesting that sequences located in these regions are subjected to recombination. To support this hypothesis we introduced a double-strand break (DSB) at a specific target site in a T. cruzi subtelomeric region cloned into an artificial chromosome (pTAC). This construct was used to transfect T. cruzi epimastigotes expressing the I-SceI meganuclease. Examination of the repaired sequences showed that DNA repair occurred only through homologous recombination (HR) with endogenous subtelomeric sequences. Our findings suggest that DSBs in subtelomeric repetitive sequences followed by HR between them may contribute to increased variability in T. cruzi multigene families.
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The cDNA sequence of the myostatin gene in the Pacific lion-paw Nodipecten subnodosus (Ns-mstn) was characterized, and the temporal expression during grow-out was analyzed for the first time in a scallop. Ns-mstn encodes a 459-amino-acid protein in which two propeptide proteolytic sites were identified, the previously recognized (RSKR) and a second one at position 266-269 aa (RRKR). The alternative furin cleavage site could be related with post-translational processing, or it could be a tissue-specific mechanism for signaling activity. The Ns-mstn transcript was located by in situ hybridization in sarcomeres and around the nucleus of muscle fibers. The temporal expression analysis by qPCR in the adductor muscle showed that Ns-mstn expression was significantly different (P < 0.05) between months during the grow-out period, increasing largely during the summer months when both biomass and muscle weight did not increase or even decreased; muscle fiber size and number were found to decrease significantly. Exogenous and endogenous factors such as high temperature and low food availability, as well as gametogenesis and reproduction, can be associated with the growth pattern and Ns-mstn expression changes. Our results indicate that MSTN is involved in adductor muscle growth regulation in N. subnodosus as it occurs in vertebrate skeletal muscle although Ns-mstn expression in non-muscle organs/tissues suggests additional functions.
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Expresión Génica , Miostatina/genética , Pectinidae/crecimiento & desarrollo , Pectinidae/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Ambiente , Hibridación in Situ , Datos de Secuencia Molecular , Desarrollo de Músculos , Miostatina/metabolismo , Especificidad de Órganos , Pectinidae/metabolismo , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
BACKGROUND: Trypanosoma brucei is a primitive parasitic protozoan that thrives in diverse environments such as the midgut of the tsetse fly and the blood of a mammalian host. For an adequate adaptation to these environments, the parasite's aquaglyceroporins play an important role. METHODS AND RESULTS: In order to test their ability to transport trivalent arsenic and antimony, we expressed the three known Trypanosoma brucei aquaglyceroporins (TbAQPs) in the heterologous systems of yeast null aquaporin mutant and Xenopus laevis oocytes. For both expression systems, we found a pH dependent intracellular accumulation of As(III) or Sb(III) mediated by all of the three TbAQPs, with the exception of TbAQP1-As(III) uptake. Additionally, we observed that Trypanosoma brucei aquaglyceroporins allow the passage of As(III) in both directions. CONCLUSION: Taken together, these results demonstrated that T. brucei aquaglyceroporins can serve as entry routes for As(III) and Sb(III) into the parasitic cell, and that this uptake is pH sensitive. Therefore, aquaporins of protozoan parasites may be considered useful as a vehicle for drug delivery.
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Antimonio/metabolismo , Acuagliceroporinas/metabolismo , Arsenitos/metabolismo , Trypanosoma brucei brucei/metabolismo , Transporte Biológico , Concentración de Iones de HidrógenoRESUMEN
Genetic variation among Aedes aegypti populations can greatly influence their vector competence for human pathogens such as the dengue virus (DENV). While intra-species transcriptome differences remain relatively unstudied when compared to coding sequence polymorphisms, they also affect numerous aspects of mosquito biology. Comparative molecular profiling of mosquito strain transcriptomes can therefore provide valuable insight into the regulation of vector competence. We established a panel of A. aegypti strains with varying levels of susceptibility to DENV, comprising both laboratory-maintained strains and field-derived colonies collected from geographically distinct dengue-endemic regions spanning South America, the Caribbean, and Southeast Asia. A comparative genome-wide gene expression microarray-based analysis revealed higher basal levels of numerous immunity-related gene transcripts in DENV-refractory mosquito strains than in susceptible strains, and RNA interference assays further showed different degrees of immune pathway contribution to refractoriness in different strains. By correlating transcript abundance patterns with DENV susceptibility across our panel, we also identified new candidate modulators of DENV infection in the mosquito, and we provide functional evidence for two potential DENV host factors and one potential restriction factor. Our comparative transcriptome dataset thus not only provides valuable information about immune gene regulation and usage in natural refractoriness of mosquito populations to dengue virus but also allows us to identify new molecular interactions between the virus and its mosquito vector.
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Aedes/genética , Aedes/virología , Virus del Dengue/inmunología , Regulación de la Expresión Génica , Interacciones Huésped-Patógeno , Insectos Vectores , Aedes/inmunología , Animales , Asia Sudoriental , Región del Caribe , Femenino , Perfilación de la Expresión Génica , Análisis por Micromatrices , América del SurRESUMEN
INTRODUCTION: The negative homozygous condition for the Duffy blood group (Fy-/Fy-) confers natural resistance to Plasmodium vivax infection. Studies carried out in pursuing this direction in Colombia are scarce. OBJECTIVE: To describe the relationship between Duffy genotypes in three ethnic communities of La Italia (Chocó) and malarial infection. METHODS: This is a descriptive, cross-sectional study in symptomatic and asymptomatic subjects with malaria. SAMPLE SIZE: Afro-Colombians 73; Amerindian (Emberá) 74, and Mestizo, 171. The presence of Plasmodium infection was assessed by thick smear and the status of the Duffy gene was studied by PCR and RFLP to help identify changes to T-46C and A131G which originate the genotypes T/T, T/C , C/C and G/G, G/A, A/A. RESULTS: Infection by Plasmodium was detected in 17% of cases with 62% due to P. falciparum and 27% due to P. vivax. Duffy genotypes were significantly associated with ethnicity (p= 0.003). Individuals with the C/C, A/A diplotypes were exclusively infected by P. falciparum, whereas the other diplotypes were infected with either of the species. In the Amerindian and Mestizo populations, the frequency of the T-46 allele was 0.90-1.00, among Afro-Colombians this was 0.50, the same as with the C allele and with an absence of heterozygous. At locus 131, the maximum frequency of the G allele was 0.30 in Amerindians and the maximum of the A allele was 0.69 in Afro-Colombians. CONCLUSIONS: In the Amerindian and mestizo populations studied, there was a predominance of the allele T-46 (FY+) but this was not observed with the P. vivax infection. P. vivax was ruled out in all FY- individuals.
INTRODUCCIÓN: La condición homocigótica negativa del grupo sanguíneo Duffy ((Fy-/Fy-) confiere resistencia natural a Plasmodium vivax. En este sentido, los estudios realizados en Colombia son escasos. OBJETIVO: describir la relación entre los genotipos Duffy en tres comunidades étnicas de La Italia (Chocó), y la malaria. MÉTODOS: estudio descriptivo, transversal con individuos sintomáticos o asintomáticos de malaria. Tamaño muestral por etnia: afrocolombiana 73; amerindia 74, mestiza 171. La infección plasmodial se estudió por gota gruesa y el estado del gen Duffy por PCR y RFLP con el fin de identificar los cambios T-46C y A131G que originan los genotipos T/T, T/C , C/C y G/G, G/A, A/A. RESULTADOS: se encontró infección plasmodial en 17% con 62% por P. falciparum y 27% por P. vivax. Se halló relación entre genotipos Duffy y etnia (p= 0.003). Los individuos con diplotipos C/C,A/A se infectaron exclusivamente con P. falciparum, mientras que otros diplotipos por las dos especies. En amerindios y mestizos la frecuencia del alelo T-46 fue 0.90-1.00, en afrocolombianos fue 0.50, al igual que el alelo C, con ausencia de heterocigotos. En el locus 131 la máxima frecuencia del alelo G fue 0.30 en amerindios y la máxima del alelo A fue 0.69 en afrocolombianos. CONCLUSIONES: En las poblaciones amerindia y mestiza estudiadas predomina el alelo T-46 (FY+), pero no predomina en ellas la infección por P. vivax. Ningún individuo FY- tuvo infección por P. vivax.
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Abalone species are different from most mollusks utilized in aquaculture as they are known to hybridize in laboratory-induced matings. Allotriploidization of hybrid abalone has not yet been studied, and methodology useful in verifying the genotypic condition of such allotriploids do not exist. Genotypic verification of hybridization and allotriploidization in a cross of Haliotis fulgens and Haliotis rufescens was performed utilizing 6 crossamplifying microsatellite loci. Five H. rufescens spawns were used in this experiment, dividing each spawn into control and experimental hybrid groups and further into diploids and triploids. Two microsatellite loci developed for H. fulgens and H. rufescens allowed for the genotypic identification of hybrids within diploid and triploids. To further verify the percentage of allotriploids within the genotypic hybrids in the triploid hybrid groups, microsatellite loci originally developed in Haliotis corrugata and Haliotis kamtschatkana were tested for crossamplification in H. fulgens and H. rufescens. Of 21 loci, 4 were chosen for this study based on their crossamplification, heterozygosity in the females, and centromere recombination frequencies. Allotriploids in triploid-hybrid larvae were then detected by identifying larvae with recombinant genotypes at any of those loci. One family had low success verification associated with reduced recombination frequencies for all loci in that family. These results demonstrate that allotriploid verification at larval stages is feasible but depends on the number of loci available, their crossamplification in the species, and their recombination frequencies.
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Repeticiones de Microsatélite/genética , Moluscos/genética , Poliploidía , Animales , Femenino , Variación Genética , Genotipo , Heterocigoto , Larva/genética , Moluscos/crecimiento & desarrollo , Recombinación GenéticaRESUMEN
The distribution of allele frequencies and haplotypes for 12 STRs loci, (DYS19, DYS389I/II, DYS390, DYS391, DYS392, DYS393, DYS385a/b, DYS437, DYS438 and DYS439) on the Y-chromosome from two Venezuelan populations were determined in 173 DNA samples of unrelated males living in Caracas (62) and Maracaibo (111). Some parameters of forensic importance were calculated. AMOVA and genetic distances between these populations were estimated. The results confirmed Y-STR genotypes as useful markers for forensic genetics analysis.
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Cromosomas Humanos Y/genética , Genética Forense , Genética de Población , Secuencias Repetidas en Tándem , Etnicidad/genética , Frecuencia de los Genes/genética , Marcadores Genéticos , Haplotipos , Humanos , Masculino , VenezuelaRESUMEN
Después de 20 años de experiencia y de 193 trasplantes cardiacos realizados, utilizando el modelo de riesgos proporcionales de Cox, fue posible evaluar las diferentes variables de riesgo, tanto pre como intra y post-operatorias, para construir un modelo de riesgo para la población sometida al procedimiento quirúrgico. Para determinar la significancia de cada una de las variables, se utilizó la ecuación de Breslow.Las variables identificadas como de riesgo fueron: enfermedad ácido-péptica, falla hepática, historia de tabaquismo, cirugía previa que comprometiera el pericardio, tiempo de ventilación prolongado, técnica quirúrgica de implantación, edad, sangrado asociado con anticoagulación y tiempo de inicio de la ciclosporina. Finalmente, las variables incluidas en el modelo de Cox fueron: presencia de enfermedad hepática, edad y tiempo de ventilación (mayor o igual a 48 horas)...
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Trasplante de Corazón , Riesgo , SobrevidaAsunto(s)
Neuraminidasa/genética , Neuraminidasa/metabolismo , Proteínas Protozoarias/genética , Proteínas Protozoarias/metabolismo , Telómero/genética , Trypanosoma/enzimología , Secuencia de Aminoácidos , Animales , Glicoproteínas , Datos de Secuencia Molecular , Neuraminidasa/química , Proteínas Protozoarias/química , Análisis de Secuencia de ADN , Trypanosoma/genética , Trypanosoma/crecimiento & desarrolloRESUMEN
El riesgo de infección por el virus del dengue durante el embarazo se está incrementando ante mayores y más severas epidemias, y las consecuencias sobre el feto y el recién nacido han sido poco estudiadas y, en otros casos, los resultados han sido contradictorios. Por esta razón, se realizó en Medellín un estudio de cohorte retrospectiva, cuyo objetivo fue determinar los efectos que produce el dengue durante el embarazo sobre el feto y el recién nacido. En dicho estudio se evaluaron 22 recién nacidos hijos de mujeres que presentaron dengue durante la epidemia de 1998 y se compararon con 24 recién nacidos, hijos de mujeres embarazadas sin dengue. En la cohorte con dengue se encontraron 3 niños prematuros, 3 niños con sufrimiento fetal y 4 niños con bajo peso al nacer. En la cohorte no expuesta no se encontraron niños con estos problemas. El desarrollo psicomotor fue normal en ambos grupos. De las observaciones anteriores, sólo fue estadísticamente significativa la frecuencia de niños con bajo peso al nacer (prueba exacta de Fisher, p=0,045). Estos resultados preliminares muestran que los recién nacidos de madres que sufrieron dengue durante la gestación tuvieron riesgo de bajo peso al nacer y presentaron con mayor frecuencia prematurez y sufrimiento fetal, aunque se requiere aumentar el tamaño de la muestra para confirmar estos resultados. Sin embargo, es necesario estrechar la vigilancia a las madres embarazadas con dengue dados los efectos nocivos sobre la evolución del recién nacido.
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Embarazo , Dengue , Feto , Recién NacidoRESUMEN
The risk of dengue virus infection during pregnancy has increased due to the current rash of frequent and severe dengue epidemics. The effects of dengue virus in the fetus and newborn children have been studied only superficially and with contradictory results. Therefore, a retrospective cohort study was conducted in Medellin, Colombia, to describe the fetal and postnatal effects of dengue virus infection acquired during pregnancy. Twenty-two babies born from mothers who suffered dengue during the epidemics of 1998 were compared with babies from non-infected mothers. In the exposed cohort, three premature births occurred, three children suffered from fetal anomalies and four children were born with low weight. In the non-exposed children, none of these problems were found. Psychomotor development was normal in both groups. Only the low weight subgroup was statistically significant (Fisher test, p = 0.045). These results suggested that the children from women with dengue during pregnancy present low weight, greater frequency of premature birth and increased fetal distress. A larger sample is necessary to confirm these results.
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Dengue , Complicaciones Infecciosas del Embarazo , Resultado del Embarazo , Estudios de Cohortes , Dengue/epidemiología , Femenino , Enfermedades Fetales/epidemiología , Humanos , Recién Nacido , Embarazo , Estudios RetrospectivosRESUMEN
El análisis citogenético de tumores ha proporcionado valiosa información sobre la biología del cáncer. Se ha establecido que más de la mitad de los tumores sólidos presentan alteraciones cromosómicas; por lo tnato, el análisis citogenético es de gran utilidad para el diagnósticos y el pronóstico. La identificación de cambios cromosómicos específicos recurrentees en numerosos tumores se considera un indicador de importancia clínica. Los estudios en este campo han revelado cerca de 100.000 alteraciones cromosómicas en más de de 30.000 neoplasias humanas. Sin embargo, los tumores sólidos son los menos caracterizados citogenéticamente, sólo una tercera parte del totalde ellos, debido a problemas técnicos en los cultivos celulares. La citogenética convencional ha sido muy útil para la posterior caracterización molecular de nuevos oncogenes y genes supresores de tumores involucrados en la génesis tumoral. En esta revisión se presentan algunos aspectos relacionados con el cáncer de etiología cromosómica, tipos de alteraciones cromosómicas, origen, frecuencia, técnicas modernas para su estudio, así como el impacto en el diagnóstico y el pronóstico del cáncer.
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Neoplasias , Aberraciones Cromosómicas , Citogenética , CariotipificaciónRESUMEN
Among the plants collected from the Pie de Vaca Formation of the Oligocene, of Tepexi de Rodríguez, Puebla, México are five plants of Anacardiaceae, Haplorhus medranoensis, Rhus toxicodendron, Rhus sp., Comocladia intermedia, and Pistacia marquezii represented by their leaves and/or leaflets. The past and present diversity and geographic distribution of one of these genera, Rhus, demonstrate its capability to adapt and diversify in a wide variety of environments. Leaf architecture characters of this taxon overlap with those of other genera in the family, suggesting a high degree of phenotypic plasticity. The presence in the Pie de Vaca Formation of a type of Pistacia with leaf architecture characters similar to those of Asian plants further supports a long history of exchange between low-latitude North America and Asia. Links between low-latitude North and South America and the Caribbean are suggested by the presence of Comocladia and Haplorhus. Whereas Comocladia highlights the long history of regional endemics in the area, Haplorhus, today an endemic monotypic genus of Peru, suggests exchange mechanisms between North and South America. The morphologic characters of these taxa, and those of Pseudosmodingium (Anacardiaceae), some Rosaceae, Leguminosae, and Berberidaceae, suggest that the Pie de Vaca community was established and evolved in harsh environmental conditions. The Pie de Vaca flora thus provides significant new insights into the biogeographic relationships of the low latitude vegetation of North America.