79 research outputs found
Formas clínicas de la demodicosis canina : no todo son alopecias
La demodicosis canina es una conocida y frecuente enfermedad cutánea, que puede afectar a los perros, causada por ácaros del género Demodex. Su clínica cutánea suele estar caracterizada por la presencia de eritema y alopecia, debido principalmente a la localización folicular del ácaro. Sin embargo, y de manera menos habitual, la enfermedad puede presentarse también con otras formas clínicas, junto o no con alopecia, pudiendo aparecer como síntomas principales o únicos de la enfermedad pequeños nódulos, "tapones" foliculares, descamaciones, cuadros seborreicos, pústulas localizadas o generalizadas, comedones, costras y úlceras con excoriación. El artículo resume las presentaciones clínicas de la demodicosis canina haciendo incidencia en las formas menos habituales de la enfermedad
Neoplasias orales en el perro y en el gato
En el presente trabajo se revisan las principales neoplasias orales del perro y del gato, de acuerdo con la experiencia clínica de los autores. Para cada neoplasia se discute la etiología y el cuadro clínico, y los autores recomiendan unas determinadas pautas de diagnóstico y tratamiento.In this paper the most frequent neoplasias of the oral cavity of the dog and cat are described and discussed according to the clinical experience of the autbors. For each neoplasia a diagnostic and therapeutic approach is proposed
Uso del lufenurón en el control de la dematitis alérgica a la picadura de pulgas en los perros
Uso del Lufenurón en el control de la Dermatitis Alérgicá a la Picadura de la Pulga en perros Debido al poco conocimiento que existe de los factores óptimos para prevenir la sensibilización a las pulgas , es difícilproponer programas efectivos que controlen a largo plazo la Dermatitis Alérgica a la Picadura de la Pulga (DAPP). En España, los veterinarios documentaron casos de perros con DAPP que presentaban una notable mejoría de su sintomatología con el uso del Lufenuron (PROGRAMa). Este estudio multicéntrico abierto fue diseñado para investigar estos hechos y probar el interés del tratamiento mensual con lufenurón como método de control y prevención de la DAPP en perros, bajo condiciones clínicas prácticas. Entre 14 centros, se seleccionó un total de 78 perros que fueron seguidos durante 12 meses. Los resultados mostraron que el uso continuado de Lufenurón es beneficioso para el perro con dermatitis alérgica a la picadura, ya que disminuye de manera significativa el riesgo de sufrir recidivas. Este hecho fue también demostrado en un ensayo multicèntrico, randornizado, paralelo doble ciego realizado en Francia.The use of Lufenuron in the control of Flea Allergy Dermatitis in Dogs As there is little knowledge of the optimum factors to prevent flea sensitisation, it is often difficult for veterinarians to propose effective programmes for the long-term control of Flea Allergy Dermatitis (FAD). In Spain, reports from veterinarians suggested that dogs with FAD were free or relieved of the symptoms after using Lufenuron (PROGRAMa). This multicentric open study was designed to verify the role of monthly Lufenuron treatment in the control and prevention of FAD in dogs under veterinary practice conditions. 14 investigators recruited 78 dogs that were followed up during 12 months. The results showed that the continuous use of Lufenuron is of siqnificant benefit to dogs suffering from FAD, reducing significantly the risk of FAD relapses in susceptibles dogs as it has also been demonstrated in a multicenter, placebo-centrolled, randomised, parallel, double-blind trial in France
Solving the initial conditions problem for modified gravity theories
Modified gravity theories such as Einstein scalar Gauss Bonnet (EsGB) contain
higher derivative terms in the spacetime curvature in their action, which
results in modifications to the Hamiltonian and momentum constraints of the
theory. In principle, such modifications may affect the principal part of the
operator in the resulting elliptic equations, and so further complicate the
already highly non-linear, coupled constraints that apply to the initial data
in numerical relativity simulations of curved spacetimes. However, since these
are effective field theories, we expect the additional curvature terms to be
small, which motivates treating them simply as an additional source in the
constraints, and iterating to find a solution to the full problem. In this work
we implement and test a modification to the CTT/CTTK methods of solving the
constraints for the case of the most general four derivative, parity invariant
scalar-tensor theory, and show that solutions can be found in both
asymptotically flat/black hole and periodic/cosmological spacetimes, even up to
couplings of order unity in the theory. Such methods will allow for numerical
investigations of a much broader class of initial data than has previously been
possible in these theories, and should be straightforward to extend to similar
models in the Horndeski class.Comment: 9 pages, 4 figures, comments welcome
Planarians as a model to assess in vivo the role of matrix metalloproteinase genes during homeostasis and regeneration
Matrix metalloproteinases (MMPs) are major executors of extracellular matrix remodeling and, consequently, play key roles in the response of cells to their microenvironment. The experimentally accessible stem cell population and the robust regenerative capabilities of planarians offer an ideal model to study how modulation of the proteolytic system in the extracellular environment affects cell behavior in vivo. Genome-wide identification of Schmidtea mediterranea MMPs reveals that planarians possess four mmp-like genes. Two of them (mmp1 and mmp2) are strongly expressed in a subset of secretory cells and encode putative matrilysins. The other genes (mt-mmpA and mt-mmpB) are widely expressed in postmitotic cells and appear structurally related to membrane-type MMPs. These genes are conserved in the planarian Dugesia japonica. Here we explore the role of the planarian mmp genes by RNA interference (RNAi) during tissue homeostasis and regeneration. Our analyses identify essential functions for two of them. Following inhibition of mmp1 planarians display dramatic disruption of tissues architecture and significant decrease in cell death. These results suggest that mmp1 controls tissue turnover, modulating survival of postmitotic cells. Unexpectedly, the ability to regenerate is unaffected by mmp1(RNAi). Silencing of mt-mmpA alters tissue integrity and delays blastema growth, without affecting proliferation of stem cells. Our data support the possibility that the activity of this protease modulates cell migration and regulates anoikis, with a consequent pivotal role in tissue homeostasis and regeneration. Our data provide evidence of the involvement of specific MMPs in tissue homeostasis and regeneration and demonstrate that the behavior of planarian stem cells is critically dependent on the microenvironment surrounding these cells. Studying MMPs function in the planarian model provides evidence on how individual proteases work in vivo in adult tissues. These results have high potential to generate significant information for development of regenerative and anti cancer therapies
Transcriptomic analysis of planarians under simulated microgravity or 8 g demonstrates that alteration of gravity induces genomic and cellular alterations that could facilitate tumoral transformation
Transcriptomic analysis of planarians under simulated microgravity or 8 g demonstrates that alteration of gravity induces genomic and cellular alterations that could facilitate tumoral transformation
GRFolres: A code for modified gravity simulations in strong gravity
GRFolres is an open-source code for performing simulations in modified
theories of gravity, based on the publicly available 3+1D numerical relativity
code GRChombo.
Note: Submitted for review in the Journal of Open Source Software; Comments
welcome; The code can be found at https://github.com/GRChombo/GRFolre
Planarian regeneration: achievements and future directions after 20 years of research.
Planarians can undergo dramatic changes in body size and regenerate their entire body plan from small pieces after cutting. This remarkable morphological plasticity has made them an excellent model in which to analyze phenomena such as morphogenesis, restoration of pattern and polarity, control of tissue proportions and tissue homeostasis. They have a unique population of pluripotent stem cells in the adult that can give rise to all differentiated cell types, including the germ cells. These cellular characteristics provide an excellent opportunity to study the mechanisms involved in the maintenance and differentiation of cell populations in intact and regenerating animals. Until recently, the planarian model system lacked opportunities for genetic analysis; however, this handicap was overcome in the last decade through the development of new molecular methods which have been successfully applied to planarians. These techniques have allowed analysis of the temporal and spatial expression of genes, as well as interference with gene function, generating the first phenotypes by loss or gain of function. Finally, the sequencing of the planarian genome has provided the essential tools for an in-depth analysis of the genomic regulation of this model system. In this review, we provide an overview of planarians as a model system for research into development and regeneration and describe new lines of investigation in this area
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