Mammalian hibernators survive prolonged periods of cold and resource scarcity by temporarily modulating normal physiological functions, but the mechanisms underlying these adaptations are poorly understood. The hibernation cycle of thirteen-lined ground squirrels lasts for 5-7 months and comprises weeks of hypometabolic, hypothermic torpor interspersed with 24-48-hour periods of an active-like interbout arousal (IBA) state. We show that ground squirrels, who endure the entire hibernation season without food, have negligible hunger during IBAs. These squirrels exhibit reversible inhibition of the hypothalamic feeding center, such that hypothalamic arcuate nucleus neurons exhibit reduced sensitivity to the orexigenic and anorexigenic effects of ghrelin and leptin, respectively. However, hypothalamic infusion of thyroid hormone during an IBA is sufficient to rescue hibernation anorexia. Our results reveal that thyroid hormone deficiency underlies hibernation anorexia and demonstrate the functional flexibility of the hypothalamic feeding center.
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http://dx.doi.org/10.1101/2023.03.15.532843 | DOI Listing |
Clin Transl Med
January 2025
Department of Cardiovascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Background: Sporadic aortic aneurysm and dissection (AAD) is a critical condition characterised by the progressive loss of vascular smooth muscle cells (VSMCs) and the breakdown of the extracellular matrix. However, the molecular mechanisms responsible for the phenotypic switch and loss of VSMCs in AAD are not fully understood.
Methods And Results: In this study, we employed a discovery-driven, unbiased approach.
Vet Sci
December 2024
College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu 611130, China.
Yak (), a special breed of cattle on the Qinghai-Tibet Plateau, has low fertility due to nutritional deficiency, especially the trace elements. The steroid hormones estradiol (E2) and progesterone (P4) synthesized by yak follicular granulosa cells (BGCs) are involved in the entire reproductive process. In the present study, we investigated the effects of trace elements and vitamins on yak follicular GCs, including the cellular activity, the synthesis of E2 and P4, and the expression of genes related to steroid hormone synthesis.
View Article and Find Full Text PDFMetabolites
December 2024
IVF Unit, Department of Obstetrics and Gynecology, Faculty of Medicine, School of Health Sciences, University of Thessaly, 41110 Larissa, Greece.
Thalassemia is an autosomal recessive hereditary chronic hemolytic anemia characterized by a partial or complete deficiency in the synthesis of alpha- or beta-globin chains, which are essential components of adult hemoglobin. Mutations in the globin genes lead to the production of unstable globin chains that precipitate within cells, causing hemolysis. This shortens the lifespan of mature red blood cells (RBCs) and results in the premature destruction of RBC precursors in the bone marrow.
View Article and Find Full Text PDFClin Endocrinol (Oxf)
December 2024
Department of Medicine, University of Auckland, Auckland, New Zealand.
Objective: Vitamin D deficiency (VDD) in children can cause hypocalcaemia and rickets, but the prevalence of these complications and the 25-hydroxyvitamin D (25OHD) concentrations below which they arise is uncertain. We investigated this in children (< 18 years) with 25OHD measurements.
Design, Measurement And Patients: We obtained 25OHD results from the regional laboratory database, alongside albumin-adjusted serum calcium (aCa), parathyroid hormone (PTH) and alkaline phosphatase (ALP) within 6 months of the index 25OHD.
Front Endocrinol (Lausanne)
December 2024
The Fertility Clinic, Skive Regional Hospital, Skive, Department of Clinical Medicine, Aarhus University, Skive, Denmark.
Background: In a global effort to assess expert perspectives on the use of recombinant gonadotropins, recombinant human luteinizing hormone (r-hLH) and recombinant human follicle-stimulating hormone (r-hFSH), a consensus meeting was held in Dubai. The key aim was to address three critical questions: What are the factors that influence follicle response to gonadotropins? Which categories of patients are most likely to benefit from LH supplementation? And what are the optimal management strategies for these patients?
Methods: A panel of thirty-six experts reviewed and refined the initial statements and references proposed by the Scientific Coordinator. Consensus was defined as agreement or disagreement by more than two-thirds (66%) of the panel members for each statement.
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