RESUMO
Free fatty acid receptors (FFAR) play significant roles in various physiological processes, including energy metabolism, through interaction with their ligands, fatty acids. To determine whether the receptors FFAR1 and FFAR2 are involved in the regulation of liver metabolism during the peripartal period, we selected 13 German Holstein multiparous dairy cows and grouped them as high ß-hydroxybutyrate (H-BHB; n = 8) or low ß-hydroxybutyrate (L-BHB; n = 5) according to their individual maximum plasma BHB concentration observed within wk 2 or 3 postpartum (H-BHB: >1 mmol/L and L-BHB: <0.77 mmol/L). The selected cows had a milk yield of more than 10,000 kg/305 d during a previous lactation. The cows were fed a total mixed ration according to their requirements during the far-off dry period [5.9 MJ of net energy for lactation (NEL)/kg of dry matter (DM), crude protein (CP) 126 g/kg of DM], close-up dry period (6.5 MJ of NEL/kg of DM, CP 137 g/kg of DM), and lactation (7 MJ of NEL/kg of DM, CP 163 g/kg of DM). Blood samples were taken weekly, from d -34 to d 40 relative to parturition. Liver biopsies were taken on d -34, -17, 3, 18, and 30 relative to parturition and at slaughter (d 40). The protein abundance of FFAR1 was lower during the whole peripartal period in the H-BHB group. The abundance of FFAR2 increased over time and tended to be higher in H-BHB cows. The abundance of FFAR1 might be associated with imbalances of liver metabolism in peripartal dairy cows.
Assuntos
Ácido 3-Hidroxibutírico/sangue , Ácidos Graxos não Esterificados/sangue , Animais , Bovinos , Dieta/veterinária , Feminino , Lactação , Fígado/metabolismo , Leite/metabolismo , Período Pós-PartoRESUMO
The evaluation of greenhouse gas mitigation strategies requires the quantitative assessment of individual methane production. Because methane measurement in respiration chambers is highly accurate, but also comprises various disadvantages such as limited capacity and high costs, the establishment of an indicator for estimating methane production of individual ruminants would provide an alternative to direct methane measurement. Methyl-coenzyme M reductase is involved in methanogenesis and the subunit α of methyl-coenzyme M reductase is encoded by the mcrA gene of rumen archaea. We therefore examined the relationship between methane emissions of Holstein dairy cows measured in respiration chambers with 2 different diets (high- and medium-concentrate diet) and the mcrA DNA and mcrA cDNA abundance determined from corresponding rumen fluid samples. Whole-body methane production per kilogram of dry matter intake and mcrA DNA normalized to the abundance of the rrs gene coding for 16S rRNA correlated significantly when using qmcrA primers. Use of qmcrA primers also revealed linear correlation between mcrA DNA copy number and methane yield. Regression analyses based on normalized mcrA cDNA abundances revealed no significant linear correlation with methane production per kilogram of dry matter intake. Furthermore, the correlations between normalized mcrA DNA abundance and the rumen fluid concentration of acetic and isobutyric acid were positive, whereas the correlations with propionic and lactic acid were negative. These data suggest that the mcrA DNA approach based on qmcrA primers could potentially be a molecular proxy for methane yield after further refinement.
Assuntos
Bovinos/fisiologia , Dosagem de Genes , Metano/metabolismo , Oxirredutases/metabolismo , Animais , Dieta/veterinária , Feminino , Oxirredutases/genética , RNA Ribossômico 16S/genética , Rúmen/metabolismoRESUMO
The successful regrowth of retinal ganglion cell (RGC) axons after optic nerve (ON) axotomy in Gallotia galloti indicates a permissive role of the glial environment. We have characterised the astroglial lineage of the lizard optic pathway throughout its ontogeny (embryonic stage 30 [E30] to adults) by using electron microscopy and immunohistochemistry to detect the proliferation marker PCNA (proliferating cell nuclear antigen), the transcription factor Pax2 and the gliofilament proteins vimentin (Vim) and GFAP (glial fibrillary acidic protein). PCNA(+) cells were abundant until E39, with GFAP(+)/PCNA(+) astrocytes being observed between E37 and hatching. Proliferation diminished markedly afterwards, being undetectable in the adult optic pathway. Müller glia of the central retina expressed Pax2 from E37 and their endfeet accumulated Vim from E33 and GFAP from E37 onwards. Astrocytes were absent in the avascular lizard retina, whereas abundant Pax2(+) astrocytes were observed in the ON from E30. A major subpopulation of these astrocytes coexpressed Vim from E35 and also GFAP from E37 onwards; thus the majority of mature astrocytes coexpressed Pax2/Vim/GFAP. The astrocytes were ultrastructurally identified by their gliofilaments, microtubules, dense bodies, desmosomes and glycogen granules, which preferentially accumulated in cell processes. Astrocytes in the adult ON coexpressed both gliofilaments and presented desmosomes indicating a reinforcement of the ON structure; this is physiologically necessary for local adaptation to mechanical forces linked to eye movement. We suggest that astrocytes forming this structural scaffold facilitate the regrowth of RGCs after ON transection.
Assuntos
Astrócitos/metabolismo , Proteína Glial Fibrilar Ácida/metabolismo , Lagartos/embriologia , Fator de Transcrição PAX2/metabolismo , Vimentina/metabolismo , Vias Visuais/embriologia , Vias Visuais/ultraestrutura , Animais , Astrócitos/citologia , Astrócitos/ultraestrutura , Diferenciação Celular , Imuno-Histoquímica , Lagartos/metabolismo , Quiasma Óptico/citologia , Quiasma Óptico/embriologia , Quiasma Óptico/metabolismo , Nervo Óptico/citologia , Nervo Óptico/embriologia , Nervo Óptico/metabolismo , Nervo Óptico/ultraestrutura , Antígeno Nuclear de Célula em Proliferação/metabolismo , Retina/citologia , Retina/embriologia , Retina/metabolismo , Retina/ultraestrutura , Vias Visuais/citologia , Vias Visuais/metabolismoRESUMO
The aim of this study was to evaluate the specificity of a polymerase chain reaction assay for detecting Brucella DNA using primers specific for the amplification of a 223 bp region of the sequence encoding a 31 kDa immunogenic Brucella abortus protein (BCSP31). DNA from all Brucella strains, including type, reference, vaccine and field strains, were correctly amplified. With the exception of Ochrobactrum spp., no other amplification was detected with a broad panel of microorganisms serologically or phylogenetically related to Brucella spp. This very good degree of specificity, together with its high yield demonstrated in previous clinical studies, confirms that this polymerase chain reaction assay could be a useful tool for the diagnosis of human brucellosis.
Assuntos
Antígenos de Bactérias/genética , Brucella/imunologia , Brucelose/diagnóstico , DNA Bacteriano/análise , Reação em Cadeia da Polimerase/métodos , Brucella/genética , Brucella/isolamento & purificação , DNA Bacteriano/química , DNA Bacteriano/isolamento & purificação , Diagnóstico Diferencial , Humanos , Sensibilidade e EspecificidadeRESUMO
Tres neonatos com quilotorax fueron observados durante un periodo de diez anos. Dos pacientes eran del sexo masculino y en todos la lesion ocurrio del lado derecho.Igualmente, los tres fueron tratados con punciones aspirativas intermitentes, ademas de formulas convencionales, con aceite de trigliceridos de cadena media y alimentacion parenteral. Los regimenes terapeuticos empleados no ofrecen ventajas entre si. Se pone de relieve la conveniencia -en nuestro medio - de practicar toracentesis segun el grado de compromiso respiratorio y proveer formulas convencionales.La toracentesis continua puede producir expoliacion de nutrientes de no ser observada cautelosamente. El cuadro clinico es de comienzo variable y la etiologia permanece oscura. Uno de los casos descriptos fue reconocido en forma prenatal mediante el examen ultrasonografico. Este hallazgo favoreceria a la hipotesis de que la lesion se produce en el utero y no por trauma obstetrico