Autophagy is Involved in Cardiac Remodeling in Response to Environmental Temperature Change.

Objectives: To study the reversibility of cold-induced cardiac hypertrophy and the role of autophagy in this process. Background: Chronic exposure to cold is known to cause cardiac hypertrophy independent of blood pressure elevation. The reversibility of this process and the molecular mechanisms involved are unknown. Methods: Studies were performed in two-month-old mice exposed to cold (4°C) for 24 h or 10 days. After exposure, the animals were returned to room temperature (21°C) for 24 h or 1 week. Results: We found that chronic cold exposure significantly increased the heart weight/tibia length (HW/TL) ratio, the mean area of cardiomyocytes, and the expression of hypertrophy markers, but significantly decreased the expression of genes involved in fatty acid oxidation. Echocardiographic measurements confirmed hypertrophy development after chronic cold exposure. One week of deacclimation for cold-exposed mice fully reverted the morphological, functional, and gene expression indicators of cardiac hypertrophy. Experiments involving injection of leupeptin at 1 h before sacrifice (to block autophagic flux) indicated that cardiac autophagy was repressed under cold exposure and re-activated during the first 24 h after mice were returned to room temperature. Pharmacological blockage of autophagy for 1 week using chloroquine in mice subjected to deacclimation from cold significantly inhibited the reversion of cardiac hypertrophy. Conclusion: Our data indicate that mice exposed to cold develop a marked cardiac hypertrophy that is reversed after 1 week of deacclimation. We propose that autophagy is a major mechanism underlying the heart remodeling seen in response to cold exposure and its posterior reversion after deacclimation.

Autophagic control of cardiac steatosis through FGF21 in obesity-associated cardiomyopathy.

OBJECTIVE: High-fat diet-induced obesity leads to the development of hypertrophy and heart failure through poorly understood molecular mechanisms. We have recently shown that fibroblast growth factor-21 (FGF21) is produced by the heart and exerts protective effects that prevent cardiac hypertrophy development and oxidative stress. The aim of this study was to determine the effects of FGF21 on the cardiomyopathy associated with obesity development. RESULTS: Fgf21-/- mice showed an enhanced increase in the heart weight/tibia length (HW/TL) ratio in response to the high-fat diet. In keeping with this, echocardiographic measurements confirmed enhanced cardiac hypertrophy in Fgf21-/- mice. At the cellular level, the area of cardiomyocytes was increased in Fgf21-/- mice fed a high-fat diet. Furthermore, a high-fat diet induced fatty acid oxidation in the hearts of Fgf21-/- mice accompanied by an increase in cardiac oxidative stress. Oil-red O staining revealed the presence of higher amounts of lipid droplets in the hearts of Fgf21-/- mice fed a high-fat diet relative to wt mice fed this same diet. Finally, Fgf21-/- mice fed a high-fat diet showed impaired cardiac autophagy and signs of inactive cardiac lipophagy, suggesting that FGF21 promotes autophagy in cardiomyocytes. CONCLUSIONS: Our data indicate that a lack of FGF21 enhances the susceptibility of mice to the development of obesity-related cardiomyopathy. Furthermore, we demonstrate that this cardiac dysfunction is associated with deleterious lipid accumulation in the heart. An impaired ability of FGF21 to promote autophagy/lipophagy may contribute to lipid accumulation and cardiac derangements.

Implications of zoonotic and vector-borne parasites to free-roaming cats in central Spain.

Cats are definitive hosts and reservoirs for several parasites, some of which are responsible for serious zoonotic diseases. We conducted a case-control study of data from a trap-neuter-return (TNR) programme (years 2014-2017) designed to examine the prevalence of zoonotic parasites in free-roaming cats living in urban areas of central Spain. In the animal population tested (n = 263), we detected a 29.2% prevalence of endoparasites, including high rates of cestodes (12.9%) and Toxocara cati (11.7%). While faecal samples showed no Toxoplasma gondii oocysts, the seroprevalence of T. gondii infection was 24.2%. Antibodies to Leishmania infantum were detected in 4.8% of the animals, though all skin and blood samples analyzed were PCR negative for this parasite. Ectoparasites (ticks and fleas) were found in 4.6% of the cat population, and 10.6% of the cats were detected with Otodectes cynotis. Finally, 6.3% and 7.9% cats tested positive for feline leukaemia virus and feline immunodeficiency virus, respectively. Our study provides useful information for animal-welfare and public-health, as the parasites detected can affect native wild animals through predation, competition and disease transmission. Our detection of zoonotic parasites such as L. infantum, T. gondii, T. cati, Giardia duodenalis and several ectoparasites prompts an urgent need for health control measures in stray cats.

Influence of different sterilization procedures and partial demineralization of screws made of bone on their mechanical properties.

Since 1992, screws made of allogenic, autoclaved human cortical bone have been employed as osteosynthesis materials. Autoclaving at 134 degrees C for 5 min makes them microbiologically safe, but on the other hand it reduces both their mechanical properties and osteoconductive capacity. The aim of this in vitro study was to determine if the mechanical properties of these screws could be improved after receiving different autoclaving procedures and partial inner demineralization, the latter additionally tending to increase their osteoconductive potential. 132 screws made of bovine cortical bone were employed. Some of them were partially demineralized with 0.6 N HCl from an inner canal performed following their longitudinal axis. All the specimens were autoclaved at 134 degrees C but under different vacuum conditions and sterilization time (A1-A2). They were then subjected to tension, shear and torque tests. A difference between both sterilization procedures was observed. Samples sterilized at 134 degrees C, 2-2.4 mbars for 5 min (A1) showed better mechanical properties than those autoclaved for longer time and higher vacuum conditions (A2). Demineralization also influenced their mechanical properties, being less resistant with increasing time. Based on these results, a standard screw made of bone and autoclaved at 134 degrees C, 2-2.4 mbars, 5 min seems to be the most appropriate, from a biomechanical point of view, to be used as osteosynthesis material.

Volume variations of bone tissue after undergoing different physical and chemical treatments.

Both autogenic and allogenic bone has been employed through different surgical procedures to fill different defects or as osteosynthesis materials. Some physical and/or chemical treatments are usually necessary before its use. Since bone volume is important from a surgical point of view, the present study was designed to analyse its possible variations when subjected to certain procedures. Screws made of bovine cortical bone were autoclaved in different conditions regarding time and vacuum (A1-A2), cryopreserved, demineralised, enzymatically digested and rehydrated. The samples were measured before and after every treatment. Sterilisation caused a volume reduction more marked with method A1 than A2 whereas freezing allowed to obtain the original size. No volumetric changes were registered after demineralisation and enzymatic digestion. Rehydration significantly increased their volume already during the first hour but the maximum value was reached at 24 h. Thus, autoclaving was the only treatment able to reduce the bone volume whilst freezing and rehydration allowed the samples to return to their original size.

Alimentos cárnicos y huevos: perfil de consumo en adultos mayores ambulatorios / Food meat and eggs: consumption profile in elderly outpatients

En los Adultos Mayores (AM) el acceso a una alimentación adecuada es primordial para mantener la salud, disminuir el efecto de las enfermedades y contribuir a preservar la independencia. Nutrientes fundamentales como las proteínas de alto valor biológico, vitaminas y minerales son aportadas por el grupo de huevos, carnes y sus derivados.Objetivos: Describir el perfil de consumo de alimentos del grupo de huevos, carnes y derivados, de los AM; evaluar si existen asociaciones en el perfil de consumo según edad, sexo, nivel educacional y convivencia. Métodos: Universo: todos los AM≥60 años ambulatorios, beneficiarios del programa ProBienestar, de Córdoba capital. Muestreo estratificado de centros de jubilados; muestra aleatoria de cada centro (n 451 AM). Instrumento: Cuestionario de Frecuencia de Consumo de Alimentos. Categorías: consumo Habitual (1 a 7 días/semana), consumo Ocasional (1 a 3 días/mes) y Nulo (no consume). Resultados: el consumo habitual (CH) prevaleció para carnes de res 93% y de aves 85%; pescados sólo 19%. El 56% no consumía pescados nunca. Para los huevos, el CH fue de 76%. Entre las vísceras preponderó el consumo ocasional (CO) siendo el hígado la más consumida (30%); igual que para embutidos: morcilla, chorizo, salchicha, mortadela y salame; y fiambres: paleta. El CO de corazón y riñón prevaleció entre los varones, y el de fiambres/embutidos fue mayor en los AM que vivían acompañados. Conclusiones: las carnes bovina y de ave (pollo), y huevos fueron los alimentos proteicos más consumidos por los AM del programa ProBienestar, Córdoba capital. El sexo se asoció al consumo de vísceras y la convivencia al de fiambres/embutidos. A excepción dehuevos y conservas de pescado (en escasa cantidad), el resto no integran el módulo alimentario otorgado a los AM del programa, no obstante los alimentos cárneos son consumidos habitualmente por esta población de bajos ingresos.

Susceptibility of bacterial isolates from chronic canine otitis externa to twenty antibiotics.

In this paper we present the results of studies on the susceptibility to antibiotics of bacteria isolated from chronic canine otitis externa. We tested 46 bacterial strains (S. aureus, coagulase-negative staphylococci, Corynebacterium spp., and gram-negative bacilli) with 20 different antibiotics. We observed increased resistance to antibiotics of bacteria isolated from canine otitis externa as compared to the resistance reported earlier. This may be due to the indiscriminate use of some antibiotics in the last years and indicates the importance of sensitivity testing for the effective treatment of chronic otitis externa, especially that caused by gram-negative bacilli. The clinician may initiate empiric treatment with antibiotics before obtaining the sensitivity test results; the best results may be expected from a topical application of Bacitracin or Chloramphenicol, and from a systemic therapy with Cephalosporines. Therapeutical scheme for treating various bacterial groups are presented in the paper.