113 resultados para hypothalamic-pituitary-adrenal axis
Resumo:
OBJECTIVES There is a growing understanding of the complexity of interplay between renal and cardiovascular systems in both health and disease. The medical profession has adopted the term "cardiorenal syndrome" (CRS) to describe the pathophysiological relationship between the kidney and heart in disease. CRS has yet to be formally defined and described by the veterinary profession and its existence and importance in dogs and cats warrant investigation. The CRS Consensus Group, comprising nine veterinary cardiologists and seven nephrologists from Europe and North America, sought to achieve consensus around the definition, pathophysiology, diagnosis and management of dogs and cats with "cardiovascular-renal disorders" (CvRD). To this end, the Delphi formal methodology for defining/building consensus and defining guidelines was utilised. METHODS Following a literature review, 13 candidate statements regarding CvRD in dogs and cats were tested for consensus, using a modified Delphi method. As a new area of interest, well-designed studies, specific to CRS/CvRD, are lacking, particularly in dogs and cats. Hence, while scientific justification of all the recommendations was sought and used when available, recommendations were largely reliant on theory, expert opinion, small clinical studies and extrapolation from data derived from other species. RESULTS Of the 13 statements, 11 achieved consensus and 2 did not. The modified Delphi approach worked well to achieve consensus in an objective manner and to develop initial guidelines for CvRD. DISCUSSION The resultant manuscript describes consensus statements for the definition, classification, diagnosis and management strategies for veterinary patients with CvRD, with an emphasis on the pathological interplay between the two organ systems. By formulating consensus statements regarding CvRD in veterinary medicine, the authors hope to stimulate interest in and advancement of the understanding and management of CvRD in dogs and cats. The use of a formalised method for consensus and guideline development should be considered for other topics in veterinary medicine.
Resumo:
During non-rapid eye movement (NREM) sleep, synchronous synaptic activity in the thalamocortical network generates predominantly low-frequency oscillations (<4 Hz) that are modulated by inhibitory inputs from the thalamic reticular nucleus (TRN). Whether TRN cells integrate sleep-wake signals from subcortical circuits remains unclear. We found that GABA neurons from the lateral hypothalamus (LHGABA) exert a strong inhibitory control over TRN GABA neurons (TRNGABA). We found that optogenetic activation of this circuit recapitulated state-dependent changes of TRN neuron activity in behaving mice and induced rapid arousal during NREM, but not REM, sleep. During deep anesthesia, activation of this circuit induced sustained cortical arousal. In contrast, optogenetic silencing of LHGABA-TRNGABA transmission increased the duration of NREM sleep and amplitude of delta (1-4 Hz) oscillations. Collectively, these results demonstrate that TRN cells integrate subcortical arousal inputs selectively during NREM sleep and may participate in sleep intensity.
Resumo:
PURPOSE In acute myeloid leukemia (AML), the transcription factors CEBPA and KLF4 as well as the universal tumor suppressor p53 are frequently deregulated. Here, we investigated the extent of dysregulation, the molecular interactions, and the mechanisms involved. EXPERIMENTAL DESIGN One hundred ten AML patient samples were analyzed for protein levels of CEBPA, KLF4, p53, and p53 modulators. Regulation of CEBPA gene expression by KLF4 and p53 or by chemical p53 activators was characterized in AML cell lines. RESULTS We found that CEBPA gene transcription can be directly activated by p53 and KLF4, suggesting a p53-KLF4-CEBPA axis. In AML patient cells, we observed a prominent loss of p53 function and concomitant reduction of KLF4 and CEBPA protein levels. Assessment of cellular p53 modulator proteins indicated that p53 inactivation in leukemic cells correlated with elevated levels of the nuclear export protein XPO1/CRM1 and increase of the p53 inhibitors MDM2 and CUL9/PARC in the cytoplasm. Finally, restoring p53 function following treatment with cytotoxic chemotherapy compounds and p53 restoring non-genotoxic agents induced CEBPA gene expression, myeloid differentiation, and cell-cycle arrest in AML cells. CONCLUSIONS The p53-KLF4-CEBPA axis is deregulated in AML but can be functionally restored by conventional chemotherapy and novel p53 activating treatments. Clin Cancer Res; 22(3); 746-56. ©2015 AACR.
Resumo:
Androgens are precursors for sex steroids and are predominantly produced in the human gonads and the adrenal cortex. They are important for intrauterine and postnatal sexual development and human reproduction. Although human androgen biosynthesis has been extensively studied in the past, exact mechanisms underlying the regulation of androgen production in health and disease remain vague. Here, the knowledge on human androgen biosynthesis and regulation is reviewed with a special focus on human adrenal androgen production and the hyperandrogenic disorder of polycystic ovary syndrome (PCOS). Since human androgen regulation is highly specific without a good animal model, most studies are performed on patients harboring inborn errors of androgen biosynthesis, on human biomaterials and human (tumor) cell models. In the past, most studies used a candidate gene approach while newer studies use high throughput technologies to identify novel regulators of androgen biosynthesis. Using genome wide association studies on cohorts of patients, novel PCOS candidate genes have been recently described. Variant 2 of the DENND1A gene was found overexpressed in PCOS theca cells and confirmed to enhance androgen production. Transcriptome profiling of dissected adrenal zones established a role for BMP4 in androgen synthesis. Similarly, transcriptome analysis of human adrenal NCI-H295 cells identified novel regulators of androgen production. Kinase p38α (MAPK14) was found to phosphorylate CYP17 for enhanced 17,20 lyase activity and RARB and ANGPTL1 were detected in novel networks regulating androgens. The discovery of novel players for androgen biosynthesis is of clinical significance as it provides targets for diagnostic and therapeutic use.
Resumo:
Magnetic Resonance Imaging of the Pituitary Gland of Horses With Pituitary Pars Intermedia Dysfunction
Resumo:
Vertebrate limbs grow out from the flanks of embryos, with their main axis extending proximodistally from the trunk. Distinct limb domains, each with specific traits, are generated in a proximal-to-distal sequence during development. Diffusible factors expressed from signalling centres promote the outgrowth of limbs and specify their dorsoventral and anteroposterior axes. However, the molecular mechanism by which limb cells acquire their proximodistal (P-D) identity is unknown. Here we describe the role of the homeobox genes Meis1/2 and Pbx1 in the development of mouse, chicken and Drosophila limbs. We find that Meis1/2 expression is restricted to a proximal domain, coincident with the previously reported domain in which Pbx1 is localized to the nucleus, and resembling the distribution of the Drosophila homologues homothorax (hth) and extradenticle (exd); that Meis1 regulates Pbx1 activity by promoting nuclear import of the Pbx1 protein; and that ectopic expression of Meis1 in chicken and hth in Drosophila disrupts distal limb development and induces distal-to-proximal transformations. We suggest that restriction of Meis1/Hth to proximal regions of the vertebrate and insect limb is essential to specify cell fates and differentiation patterns along the P-D axis of the limb.
Resumo:
We report a measurement of the νµ charged current quasi-elastic cross-sections on carbon in the T2K on-axis neutrino beam. The measured charged current quasi-elastic cross-sections on carbon at mean neutrino energies of 1.94 GeV and 0.93 GeV are (11.95 ± 0.19(stat.) +1.82−1.47(syst.)) ×10^−39 cm^2/neutron, and (10.64 ± 0.37(stat.)+2.03−1.65(syst.)) × 10^−39 cm^2/neutron, respectively. These results agree well with the predictions of neutrino interaction models. In addition, we investigated the effects of the nuclear model and the multi-nucleon interaction.
Resumo:
T2K reports its first measurements of the parameters governing the disappearance of νµ in an off-axis beam due to flavor change induced by neutrino oscillations. The quasimonochromatic νµ beam, produced with a peak energy of 0.6 GeV at J-PARC, is observed at the far detector SuperKamiokande, 295 km away, where the νµ survival probability is expected to be minimal. Using a dataset corresponding to 4.01×10²⁰ protons on target, 34 fully contained µ-like events were observed. The best-fit oscillation parameters are sin²(θ₂₃) = 0.45 and |∆m^2_32| = 2.51 × 10⁻³ eV² with 68% confidence intervals of 0.38 - 0.64 and 2.26 - 2.80 ×10⁻³ eV² respectively. These results are in agreement with existing antineutrino parameter measurements and also with the νµ disappearance parameters measured by T2K.