RESUMO
Vicuñas and guanacos are two species of wild South American camelids that are key ruminants in the ecosystems where they occur. Although closely related, these species feature differing ecologies and life history characters, which are expected to influence both their genetic diversity and population differentiation at different spatial scales. Here, using mitochondrial and microsatellite genetic markers, we show that vicuña display lower genetic diversity within populations than guanaco but exhibit more structure across their Peruvian range, which may reflect a combination of natural genetic differentiation linked to geographic isolation and recent anthropogenic population declines. Coalescent-based demographic analyses indicate that both species have passed through a strong bottleneck, reducing their effective population sizes from over 20,000 to less than 1000 individuals. For vicuña, this bottleneck is inferred to have taken place ~3300 years ago, but to have occurred more recently for guanaco at ~2000 years ago. These inferred dates are considerably later than the onset of domestication (when the alpaca was domesticated from the vicuña while the llama was domesticated from the guanaco), coinciding instead with a major human population expansion following the mid-Holocene cold period. As importantly, they imply earlier declines than the well-documented Spanish conquest, where major mass mortality events were recorded for Andean human and camelid populations. We argue that underlying species' differences and recent demographic perturbations have influenced genetic diversity in modern vicuña and guanaco populations, and these processes should be carefully evaluated in the development and implementation of management strategies for these important genetic resources.
Assuntos
Camelídeos Americanos/genética , Demografia , Variação Genética , Genética Populacional , Animais , Chile , Análise por Conglomerados , DNA Mitocondrial , Frequência do Gene , Loci Gênicos , Marcadores Genéticos , Haplótipos , Repetições de Microssatélites , PeruRESUMO
Investigations of genetic diversity and domestication in South American camelids (SAC) have relied on autosomal microsatellite and maternally-inherited mitochondrial data. We present the first integrated analysis of domestic and wild SAC combining male and female sex-specific markers (male specific Y-chromosome and female-specific mtDNA sequence variation) to assess: (i) hypotheses about the origin of domestic camelids, (ii) directionality of introgression among domestic and/or wild taxa as evidence of hybridization and (iii) currently recognized subspecies patterns. Three male-specific Y-chromosome markers and control region sequences of mitochondrial DNA are studied here. Although no sequence variation was found in SRY and ZFY, there were seven variable sites in DBY generating five haplotypes on the Y-chromosome. The haplotype network showed clear separation between haplogroups of guanaco-llama and vicuña-alpaca, indicating two genetically distinct patrilineages with near absence of shared haplotypes between guanacos and vicuñas. Although we document some examples of directional hybridization, the patterns strongly support the hypothesis that llama (Lama glama) is derived from guanaco (Lama guanicoe) and the alpaca (Vicugna pacos) from vicuña (Vicugna vicugna). Within male guanacos we identified a haplogroup formed by three haplotypes with different geographical distributions, the northernmost of which (Peru and northern Chile) was also observed in llamas, supporting the commonly held hypothesis that llamas were domesticated from the northernmost populations of guanacos (L. g. cacilensis). Southern guanacos shared the other two haplotypes. A second haplogroup, consisting of two haplotypes, was mostly present in vicuñas and alpacas. However, Y-chromosome variation did not distinguish the two subspecies of vicuñas.
Assuntos
Camelídeos Americanos/genética , DNA Mitocondrial/genética , Hibridização Genética , Cromossomo Y/genética , Animais , Argentina , Bolívia , Cruzamento , Camelídeos Americanos/classificação , Chile , Domesticação , Evolução Molecular , Feminino , Marcadores Genéticos , Variação Genética , Genética Populacional , Haplótipos , Masculino , PeruRESUMO
Thirty-nine microsatellite loci that are highly conserved in red deer, sika deer, reindeer, Soay sheep, and other artiodactyls were tested in two vulnerable and endangered Neotropical deer (pudu: Pudu puda and huemul: Hippocamelus bisulcus) with the aim of producing a standardized set of markers that can be used successfully in noninvasive samples from these species. We also compared these nonspecific loci against eight polymorphic loci that were recently developed for huemul to determine whether the nonspecific markers could reflect the huemul's genetic variation that was observed with the specific loci. We identified 10 suitable loci, six of which constitute a standardized set for the two species and can be used to identify them in the absence of phenotypic data. The expected heterozygosity per locus for the panel of six loci ranged from 0.461 to 0.889 (average 0.665), and the maximum probability of identity value was 6.9x10(-6) and 3.2x10(-4) in pudu and huemul, respectively. This set of loci has potential applications in evolutionary, ecological, forensic, and conservation studies in pudu and huemul.
Assuntos
Cervos/genética , Repetições de Microssatélites/genética , Animais , Conservação dos Recursos Naturais , Espécies em Perigo de Extinção , Reação em Cadeia da Polimerase , Polimorfismo Genético , Ovinos/genética , Especificidade da EspécieRESUMO
Sarcocystis cruzi, S. hirsuta and S. hominis are apicomplexan parasites that affect cattle worldwide with variable prevalence. The aim of the present study was to evaluate the prevalence of Sarcocystis spp. in Argentinean cattle comparing microscopic fresh examination and molecular methods. Blood, myocardium and loin samples were collected in five slaughterhouses from a total of 380 bovines. Origin of animals was representative of the major beef cattle production area of Argentina. Samples were analyzed by fresh microscopical examination, transmission electron microscopy (TEM), IFAT and PCR-RFLP. Thin walled sarcocysts corresponding with S. cruzi were found in 99.5% of heart samples. Sarcocysts were detected in 73.1% of loin samples; 71.5% had S. cruzi cysts and 23.1% had thick walled sarcocysts (S. hirsuta or S. hominis). TEM observation revealed the presence of characteristic S. hominis and S. hirsuta cyst walls in 7 and 1 loin samples respectively. Using IFAT, 379/380 animals had titers 25 or higher, showing a full agreement with fresh examination. Amplification products were detected in 35.5% (135/380) of loin samples; however Sarcocystis species could only be determined by RFLP in 29 samples. Agreement between fresh examination and PCR was low (Kappa value=0.262). This is the first report of S. hominis and S. hirsuta in Argentina. Further studies are needed to improve the sensitivity of molecular methods for species identification, especially for differentiation of S. cruzi and S. hirsuta from the zoonotic species S. hominis. The results of the present study and others focusing on sensitivity and specificity of Sarcocystis spp. diagnostic methods should contribute to improve food safety.
Assuntos
Doenças dos Bovinos/parasitologia , Sarcocystis/isolamento & purificação , Sarcocistose/veterinária , Animais , Argentina/epidemiologia , Bovinos , Doenças dos Bovinos/epidemiologia , Feminino , Masculino , Prevalência , Sarcocistose/epidemiologiaRESUMO
The vicuña (Vicugna vicugna; Miller, 1924) is a conservation success story, having recovered from near extinction in the 1960s to current population levels estimated at 275,000. However, lack of information about its demographic history and genetic diversity has limited both our understanding of its recovery and the development of science-based conservation measures. To examine the evolution and recent demographic history of the vicuña across its current range and to assess its genetic variation and population structure, we sequenced mitochondrial DNA from the control region (CR) for 261 individuals from 29 populations across Peru, Chile and Argentina. Our results suggest that populations currently designated as Vicugna vicugna vicugna and Vicugna vicugna mensalis comprise separate mitochondrial lineages. The current population distribution appears to be the result of a recent demographic expansion associated with the last major glacial event of the Pleistocene in the northern (18 to 22 degrees S) dry Andes 14-12,000 years ago and the establishment of an extremely arid belt known as the 'Dry Diagonal' to 29 degrees S. Within the Dry Diagonal, small populations of V. v. vicugna appear to have survived showing the genetic signature of demographic isolation, whereas to the north V. v. mensalis populations underwent a rapid demographic expansion before recent anthropogenic impacts.
Assuntos
Camelídeos Americanos/classificação , Camelídeos Americanos/genética , Extinção Biológica , Variação Genética , Animais , Sequência de Bases , DNA Mitocondrial/genética , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNAAssuntos
Colecistectomia Laparoscópica/efeitos adversos , Coledocolitíase/etiologia , Migração de Corpo Estranho/etiologia , Instrumentos Cirúrgicos/efeitos adversos , Colangiopancreatografia Retrógrada Endoscópica , Coledocolitíase/terapia , Feminino , Migração de Corpo Estranho/terapia , Humanos , Pessoa de Meia-Idade , Esfinterotomia Endoscópica/métodos , Resultado do TratamentoRESUMO
Los autores describen la técnica de hemorroidectomía semicerrada, como una buena alternativa que disminuye el dolor y las complicaciones postoperatorias en el tratamiento de la enfermedad hemorroidal. Esta técnica es ampliamente usada en el Brasil
Assuntos
Humanos , Hemorroidas/cirurgiaRESUMO
Esta es una revisión sobre la Anastomosis Colo-anal como procedimiento que preserva el esfínter, muy útil para enfermedades rectales benignas y malignas. La ventaja de esta técnica en el tratamiento del cáncer rectal bajo son sus buenos a excelentes resultados funcionales
Assuntos
Humanos , Anastomose Cirúrgica/métodos , Doenças do Ânus/cirurgia , Doenças Retais/cirurgiaRESUMO
Se estudiaron 55 historias clinicas de sujetos con trauma cardiaco atendidos en el Hospital de Caldas en 10 años, y 2.342 necropsias desde 1988 hasta 1991; se analizaron 179 de ellas que presentaban lesion cardiaca, de las cuales se dedujeron las siguientes observaciones: Predominio del sexo masculino; la sintomatologia predominante fue la triada de Beck; el promedio de edad fue de 23 años; el arma empleada con mayor frecuencia fue el arma de fuego seguida por el arma blanca. La pericardiocentesis se empleo en un 33 por ciento de los casos atendidos en el hospital, y la ventana subxifoidea en un 20 por ciento. En la mayoria de los pacientes la via de acceso fue a traves de la esternotomia; las lesiones encontradas más frecuentemente se localizaron sobre los ventriculos; el compromiso coronario fue escaso (2 casos); se reintervinieron 4 pacientes; las complicaciones más frecuentes fueron el hemotorax seguido de la falla cardiaca, CIV, bronconeumonia y pericarditis. De 39 casos analizables en 10 años, fallecieron 2 pacientes. La mortalidad prehospitalaria fue del 70.7 por ciento. Los hallazgos en nuestros casos fueron comparados con otras series nacionales e internacionales.
Assuntos
Traumatismos Cardíacos/cirurgia , Traumatismos Cardíacos/diagnóstico , Traumatismos Cardíacos/mortalidadeRESUMO
Se presenta un ensayo clinico prospectivo, aleatorio que evalua el tratamiento del hemotorax coagulado mediante toracoscopia comparándolo con la toracotomia de limpieza convencional. El drenaje del hemotorax coagulado postraumático por toracoscopia es un metodo de fácil aprendizaje y realizacion, seguro y eficaz,, con las ventajas de menor tiempo quirurgico, menor incapacidad postoperatoria, reincorporacion laboral temprana y resultado estetico inobjetable.