143 research outputs found

    Benign Bilateral Adenomyoepithelioma of the Mammary Gland in a Ring-tailed Lemur (Lemur catta)

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    Naturally occurring mammary tumours are uncommon in prosimians. A 20-year-old female ring-tailed lemur (Lemur catta) developed bilateral enlargement of the mammary glands. Surgical removal revealed that both masses were comprised of multiple nodules and cystic areas that entirely replaced the normal glands. Histologically, a benign neoplastic biphasic cellular proliferation, composed of luminal–epithelial and basal–myoepithelial components, was identified. Immunohistochemical analysis for expression of cytokeratin (CK) AE1/AE3, CK7, CK5 + 8, CK14, vimentin, p63 and 14-3-3σ highlighted the biphasic nature of the neoplasm. A low mitotic count, low Ki67 labelling index, expression of oestrogen receptor-α, lack of expression of human epidermal growth factor receptor and a 3-year disease-free period without recurrence supported the benign nature of the tumour. Macroscopically, histologically and immunohistochemically this neoplasm resembled benign adenomyoepithelioma of the breast in women. This is the first complete report of a naturally occurring mammary tumour in a ring-tailed lemur

    Minimally invasive blood sampling method for genetic studies on Gopherus tortoises

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    Método de extracción de sangre mínimamente invasivo para estudios genéticos en tortugas terrestres del género Gopherus La obtención de muestras de tejido de buena calidad es la primera dificultad en cualquier estudio molecular. Esto es especialmente cierto en los estudios de manejo y conservación de la fauna silvestre. En el caso de las tortugas terrestres, la fuente más habitual de ADN son las muestras de sangre obtenidas principalmente de las venas braquial y yugular por contención química, o de individuos conscientes mediante métodos de manipulación y sujeción que pueden causar estrés en el animal. Se requiere una cantidad mínima de sangre para los ensayos del PCR. A continuación, presentamos una técnica mínimamente invasiva que ha resultado eficaz para extraer pequeñas cantidades de sangre apropiadas para realizar análisis genéticos. Además, las muestras obtenidas producen una amplificación de ADN mejor que otras fuentes celulares, como las células epiteliales cloacales. Después de dos años de aplicación en tortugas terrestres silvestres, esta técnica ha demostrado ser inofensiva. Sugerimos que el muestreo de pequeñas cantidades de sangre con esta técnica podría ser útil para otro tipo de análisis, como el seguimiento fisiológico y médico.Obtaining good quality tissue samples is the first hurdle in any molecular study. This is especially true for studies involving management and conservation of wild fauna. In the case of tortoises, the most common sources of DNA are blood samples. However, only a minimal amount of blood is required for PCR assays. Samples are obtained mainly from the brachial and jugular vein after restraining the animal chemically; or from conscious individuals by severe handling methods and clamping. Herein, we present a minimally invasive technique that has proven effective for extracting small quantities of blood, suitable for genetic analyses. Furthermore, the samples obtained yielded better DNA amplification than other cell sources, such as cloacal epithelium cells. After two years of use on wild tortoises, this technique has shown to be harmless. We suggest that sampling a small amount of blood could also be useful for other types of analyses, such as physiologic and medical monitoring.Método de extracción de sangre mínimamente invasivo para estudios genéticos en tortugas terrestres del género Gopherus La obtención de muestras de tejido de buena calidad es la primera dificultad en cualquier estudio molecular. Esto es especialmente cierto en los estudios de manejo y conservación de la fauna silvestre. En el caso de las tortugas terrestres, la fuente más habitual de ADN son las muestras de sangre obtenidas principalmente de las venas braquial y yugular por contención química, o de individuos conscientes mediante métodos de manipulación y sujeción que pueden causar estrés en el animal. Se requiere una cantidad mínima de sangre para los ensayos del PCR. A continuación, presentamos una técnica mínimamente invasiva que ha resultado eficaz para extraer pequeñas cantidades de sangre apropiadas para realizar análisis genéticos. Además, las muestras obtenidas producen una amplificación de ADN mejor que otras fuentes celulares, como las células epiteliales cloacales. Después de dos años de aplicación en tortugas terrestres silvestres, esta técnica ha demostrado ser inofensiva. Sugerimos que el muestreo de pequeñas cantidades de sangre con esta técnica podría ser útil para otro tipo de análisis, como el seguimiento fisiológico y médico

    Thermoelectric transport properties of a T-shaped double quantum dot system in the Coulomb blockade regime

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    We investigate the thermoelectric properties of a T-shaped double quantum dot system described by a generalized Anderson Hamiltonian. The system's electrical conduction (G) and the fundamental thermoelectric parameters such as the Seebeck coefficient (SS) and the thermal conductivity (κ\kappa), along with the system's thermoelectric figure of merit (ZT) are numerically estimated based on a Green's function formalism that includes contributions up to the Hartree-Fock level. Our results account for finite onsite Coulomb interaction terms in both component quantum dots and discuss various ways leading to an enhanced thermoelectric figure of merit for the system. We demonstrate that the presence of Fano resonances in the Coulomb blockade regime is responsible for a strong violation of the Wiedemann-Franz law and a considerable enhancement of the system's figure of merit (ZTZT).Comment: 7 pages, 10 figure

    Evolution of screen use among youth between 2012 and 2020 in Switzerland.

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    To compare the evolution of screen and Internet use by youths between 2012 and 2020 in Switzerland. Cross-sectional studies of 10th-graders (age 13-14) were performed in Switzerland in 2012 and 2020, and compared in bivariate and multivariate analyses on sociodemographic, schooling, physical activity, emotional well-being, and screen use variables. We found that screen use had shifted to smartphones with 71.7 % of youths primarily using this device in 2020 compared to 23.2 % in 2012. In association with this change, young people's screen time had increased dramatically with an odds ratio (OR) of 11.90 for adolescents spending more than 4 h in front of screens in 2020 compared to 2012. No changes were found in the score on the Internet Addiction Test (IAT) to detect problematic screen use and for adolescents' emotional well-being. Furthermore, youths in 2020 engaged in less physical activity lasting 60 min daily, but the frequency of their extracurricular sport participation remained unchanged. Young people spend more time on screens, especially because of an increase in smartphone use in 2020. However, youths do not seem to show more problematic behaviors regarding screen use, nor has this development affected their emotional well-being. The daily and continuous use of new devices is now an integral part of young people's lives. This process seems to be part of the growth of the digital world. However, Internet and screen addiction scales should be adapted to ensure that adolescents in need of help and counseling are identified

    Pancreatic window and open necrosectomy; a surgical alternative for walled-off pancreatic necrosis in a second level hospital in Mexico

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    Walled-off pancreatic necrosis is defined as a necrotic collection with a defined wall, which generally occurs in 15% of patients in the fourth week after acute pancreatitis. Actually, open surgery is reserved for selected cases, with minimally invasive treatments such as image-assisted percutaneous drainage or endoscopic ultrasound being the procedures of choice. However, in developing countries the open approach continues to be an effective therapeutic alternative. We present the case of a 47-year-old male patient with no significant history who developed severe acute pancreatitis secondary to hypertriglyceridemia and who later developed walled-off pancreatic necrosis as a late complication. As a treatment, a debridement of the necrotic tissue with marsupialization was performed using the bradley III technique, secondary to the procedure, a pancreatic fistula was developed. After 8 weeks of hospitalization, in which he had a favourable response to surgical treatment, with spontaneous closure of the fistula without complications. Surgical management of late complications of acute pancreatitis remains controversial. Although minimally invasive procedures are the first option nowadays, in developing countries, open necrosectomy remains a good option for the treatment of these types of complications

    Two new rapid SNP-typing methods for classifying Mycobacterium tuberculosis complex into the main phylogenetic lineages

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    There is increasing evidence that strain variation in Mycobacterium tuberculosis complex (MTBC) might influence the outcome of tuberculosis infection and disease. To assess genotype-phenotype associations, phylogenetically robust molecular markers and appropriate genotyping tools are required. Most current genotyping methods for MTBC are based on mobile or repetitive DNA elements. Because these elements are prone to convergent evolution, the corresponding genotyping techniques are suboptimal for phylogenetic studies and strain classification. By contrast, single nucleotide polymorphisms (SNP) are ideal markers for classifying MTBC into phylogenetic lineages, as they exhibit very low degrees of homoplasy. In this study, we developed two complementary SNP-based genotyping methods to classify strains into the six main human-associated lineages of MTBC, the 'Beijing' sublineage, and the clade comprising Mycobacterium bovis and Mycobacterium caprae. Phylogenetically informative SNPs were obtained from 22 MTBC whole-genome sequences. The first assay, referred to as MOL-PCR, is a ligation-dependent PCR with signal detection by fluorescent microspheres and a Luminex flow cytometer, which simultaneously interrogates eight SNPs. The second assay is based on six individual TaqMan real-time PCR assays for singleplex SNP-typing. We compared MOL-PCR and TaqMan results in two panels of clinical MTBC isolates. Both methods agreed fully when assigning 36 well-characterized strains into the main phylogenetic lineages. The sensitivity in allele-calling was 98.6% and 98.8% for MOL-PCR and TaqMan, respectively. Typing of an additional panel of 78 unknown clinical isolates revealed 99.2% and 100% sensitivity in allele-calling, respectively, and 100% agreement in lineage assignment between both methods. While MOL-PCR and TaqMan are both highly sensitive and specific, MOL-PCR is ideal for classification of isolates with no previous information, whereas TaqMan is faster for confirmation. Furthermore, both methods are rapid, flexible and comparably inexpensive

    SNP assay to detect the ‘Hyuuga’ red-brown lesion resistance gene for Asian soybean rust

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    Asian soybean rust (ASR), caused by Phakopsora pachyrhizi Syd., has the potential to become a serious threat to soybean, Glycine max L. Merr., production in the USA. A novel rust resistance gene, Rpp?(Hyuuga), from the Japanese soybean cultivar Hyuuga has been identified and mapped to soybean chromosome 6 (Gm06). Our objectives were to fine-map the Rpp?(Hyuuga) gene and develop a high-throughput single nucleotide polymorphism (SNP) assay to detect this ASR resistance gene. The integration of recombination events from two different soybean populations and the ASR reaction data indicates that the Rpp?(Hyuuga) locus is located in a region of approximately 371 kb between STS70887 and STS70923 on chromosome Gm06. A set of 32 ancestral genotypes which is predicted to contain 95% of the alleles present in current elite North American breeding populations and the sources of the previously reported ASR resistance genes (Rpp1, Rpp2, Rpp3, Rpp4, Rpp5, and rpp5) were genotyped with five SNP markers. We developed a SimpleProbe assay based on melting curve analysis for SNP06-44058 which is tighly linked to the Rpp?(Hyuuga) gene. This SNP assay can differentiate plants/lines that are homozygous/homogeneous or heterozygous/heterogeneous for the resistant and susceptible alleles at the Rpp?(Hyuuga) locus
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