This study investigated the involvement of prostaglandins and regulated on activation, normal T cell expressed and secreted (RANTES), in fever induced by live Staphylococcus aureus (no. 25923, American Type Culture Collection) injection in rats. S. aureus was injected intraperitoneally at 10(9), 10(10), and 2 × 10(10) colony-forming units (CFU)/cavity, and body temperature (T(b)) was measured by radiotelemetry. The lowest dose of S. aureus induced a modest transient increase in T(b), whereas the two higher doses promoted similar long-lasting and sustained T(b) increases. Thus, the 10(10) CFU/cavity dose was chosen for the remaining experiments. The T(b) increase induced by S. aureus was accompanied by significant decreases in tail skin temperature and increases in PGE(2) levels in the cerebrospinal fluid (CSF) and hypothalamus but not in the venous plasma. Celecoxib (selective cyclooxygenase-2 inhibitor, 2.5 mg/kg po) inhibited the fever and the increases in PGE(2) concentration in the CSF and hypothalamus induced by S. aureus. Dipyrone (120 mg/kg ip) reduced the fever from 2.5 to 4 h and the PGE(2) increase in the CSF but not in the hypothalamus. S. aureus increased RANTES in the peritoneal exudate but not in the CSF or hypothalamus. Met-RANTES (100 μg/kg iv), a chemokine (C-C motif) receptor (CCR)1/CCR5 antagonist, reduced the first 6 h of fever induced by S. aureus. This study suggests that peripheral (local) RANTES and central PGE(2) production are key events in the febrile response to live S. aureus injection. As dipyrone does not reduce PGE(2) synthesis in the hypothalamus, it is plausible that S. aureus induces fever, in part, via a dipyrone-sensitive PGE(2)-independent pathway.
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http://dx.doi.org/10.1152/japplphysiol.00936.2011 | DOI Listing |
Sleep Sci
December 2024
Departamento de Psicobiologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil.
Melanin-concentrating hormone (MCH) and hypocretins (Hcrt) 1 and 2 are neuropeptides synthesized in the lateral hypothalamic area by neurons that are critical in the regulation of sleep and wakefulness. Their receptors are located in the same cerebral regions, including the frontal cortex and hippocampus. The present study aimed to assess whether 96 hours of paradoxical sleep deprivation alters the functioning of the MCH and hypocretin systems.
View Article and Find Full Text PDFSci Rep
December 2024
Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, Hunan, China.
Investigate the impact of diaphragm sellae competence on surgical outcomes and risk factors for postoperative hypothalamic injury (HI) in patients undergoing endoscopic transsphenoidal surgery (ETS) for infradiaphragmatic craniopharyngiomas (ICs). A retrospective analysis of 54 consecutive patients (2016-2023) with ICs treated by ETS was conducted. All tumors originated from the sellar region inferior to the diaphragm sellae and were classified into two subtypes in terms of diaphragm sellae competence: IC with competent diaphragm sellae (IC-CDS) and IC with incompetent diaphragm sellae (IC-IDS).
View Article and Find Full Text PDFMethods Mol Biol
November 2024
PharmTao, Santa Clara, CA, USA.
Psychoneuroimmunology (PNI) advancements may revolutionize personalized medicine by identifying systemic biomarkers that enhance diagnosis and treatment. Inflammatory pathways connect personality traits with cognitive performance, aging-related disorders, and mortality risks. Studies have demonstrated the critical interactions between personality and various biological systems like the hypothalamic-pituitary-adrenal (HPA) axis.
View Article and Find Full Text PDFMol Metab
December 2024
Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA), National University of La Plata], La Plata, Buenos Aires, Argentina; Department of Surgical Sciences, Functional Pharmacology and Neuroscience, University of Uppsala, Uppsala, Sweden. Electronic address:
Objective: The peptide hormone ghrelin exerts potent effects in the brain, where its receptor is highly expressed. Here, we investigated the role of hypothalamic tanycytes in transporting ghrelin across the blood-cerebrospinal fluid (CSF) interface.
Methods: We investigated the internalization and transport of fluorescent ghrelin (Fr-ghrelin) in primary cultures of rat hypothalamic tanycytes, mouse hypothalamic explants, and mice.
J Community Hosp Intern Med Perspect
September 2024
MedStar Health Internal Medicine Residency Program, Baltimore, MD, USA.
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