Search results for "regulation"
showing 10 items of 4463 documents
Cerebral Blood Flow Regulation Under the Conditions of Arterial Hypoxia
1978
Pronounced arterial hypoxia induces a decrease of cerebrovascular resistance and an increase of total and regional cerebral blood flow. Under the conditions of normal arterial blood pressure and normal acid base status, the changes of both parameters commence when the oxygen tension in the arterial blood decreases below approximately 50 mm Hg. At the same time, the oxygen tension in the cerebral venous blood reaches values below approximately 28 mm Hg. Different authors [23, 28, 30, 31, 33] reported that cerebral blood flow responses to PaO2 decrease are threshold at these oxygen tensions. The threshold oxygen tension of cerebral venous blood was accorded a special significance because Noel…
Increased Connexin 43 Expression as a Potential Mediator of the Neuroprotective Activity of the Corticotropin-Releasing Hormone
2009
CRH is a major central stress mediator, but also a potent neuroprotective effector. The mechanisms by which CRH mediates its neuroprotective actions are largely unknown. Here, we describe that the gap junction molecule connexin43 (Cx43) mediates neuroprotective effects of CRH toward experimentally induced oxidative stress. An enhanced gap junction communication has been reported to contribute to neuroprotection after neurotoxic insults. We show that CRH treatment up-regulates Cx43 expression and gap junctional communication in a CRH receptor-dependent manner in IMR32 neuroblastoma cells, primary astrocytes, and organotypic hippocampal slice cultures. MAPKs and protein kinase A-cAMP response…
Controlled Ovarian Stimulation Induces a Functional Genomic Delay of the Endometrium with Potential Clinical Implications
2008
Context: Controlled ovarian stimulation induces morphological, biochemical, and functional genomic modifications of the human endometrium during the window of implantation. Objective: Our objective was to compare the gene expression profile of the human endometrium in natural vs. controlled ovarian stimulation cycles throughout the early-mid secretory transition using microarray technology. Method: Microarray data from 49 endometrial biopsies obtained from LH+1 to LH+9 (n = 25) in natural cycles and from human chorionic gonadotropin (hCG) +1 to hCG+9 in controlled ovarian stimulation cycles (n = 24) were analyzed using different methods, such as clustering, profiling of biological processes…
Atrial natriuretic peptide secretion during development of the rat supraoptic nucleus
2009
Since a relationship between atrial natriuretic peptide and oxytocin was recently demonstrated in the heart (Gutkowska et al., 1997), the aim of this study was to determine whether a relationship between the two peptides is present also in the rat hypothalamus. For this purpose, we measured ANP-ontogeny in the rat hypothalamus immunohistochemically and compared it with oxytocin-ontogeny which we previously studied. The results showed that the ANP-peptide and mRNA-ANP start at the 18th day of the fetal life. Our earlier data for oxytocin in the rat hypothalamus showed that only mRNA-oxytocin appeared the 18th day of foetal life (Farina Lipari et al., 2001); thus, at the 18th day of foetal li…
Optical Coherence Tomography Angiography of Macula and Optic Nerve in Autism Spectrum Disorder: A Pilot Study
2020
The aim of this study was to compare retinal thicknesses and vascular parameters between autism spectrum disorder (ASD) and neurotypical (NT) individuals. Recruited ASD subjects and age- and sex-matched NT controls underwent 2 optical coherence tomography scans (OCT) (macular cube and optic nerve cube) and 2 OCT angiography (OCTA) scans (macular and optic nerve head (ONH) OCTA) with the device Cirrus 5000 (Zeiss). Concerning OCT, we considered full retina thickness in 9 macular sectors of the Early Treatment Diabetic Retinopathy Study (ETDRS) pattern and peripapillary retinal nerve fiber layer (pRNFL) thickness in 4 quadrants and 12 clock-hour sectors. Vessel density and capillary perfusion…
α-secretase mediated conversion of the amyloid precursor protein derived membrane stub C99 to C83 limits Aβ generation
2009
The Swedish mutation within the amyloid precursor protein (APP) causes early-onset Alzheimer's disease due to increased cleavage of APP by BACE1. While beta-secretase shedding of Swedish APP (APPswe) largely results from an activity localized in the late secretory pathway, cleavage of wild-type APP occurs mainly in endocytic compartments. However, we show that liberation of Abeta from APPswe is still dependent on functional internalization from the cell surface. Inspite the unchanged overall beta-secretase cleaved soluble APP released from APP(swe) secretion, mutations of the APPswe internalization motif strongly reduced C99 levels and substantially decreased Abeta secretion. We point out t…
Human antiphospholipid antibodies induce TNFα in monocytes via Toll-like receptor 8
2009
The antiphospholipid syndrome (APS) is characterized by recurrent arterial and/or venous thromboses, pregnancy loss and the presence of antiphospholipid antibodies (aPL). One of the discussed mechanisms of this thrombotic activity in APS patients is attributed to TNFalpha secretion in monocytes after aPL stimulation. To investigate this mechanism in detail, we employed a monoclonal aPL and IgG fractions of APS patients for stimulation of human peripheral monocytes. Stimulation with this monoclonal aPL resulted in an increased expression and secretion of TNFalpha, caused by specific upregulation of TLR8 mRNA and protein expression levels. To confirm the specificity of this finding we could d…
Inducibility of the avidin gene by progesterone is suppressed during estrogen-induced cytodifferentiation.
1992
Abstract We have studied epithelial differentiation of the chick oviduct as induced by diethylstilbestrol (DES) and 17β-estradiol (E 2 ). The proportion of goblet cells in the oviduct was slightly higher after E 2 than after DES treatment. Also avidin induction by progesterone was stronger following DES than E 2 priming. In the estrogen pretreated oviduct epithelium, avidin expression was induced by progesterone in the surface epithelial cells, protodifferentiated gland cells and tubular gland cells, but not in goblet cells. During prolonged estrogen treatment, however, the inducibility of avidin by progesterone ceased in tubular gland cells but not in surface epithelial cells. The estrogen…
Effect of Soluble Interleukin-6 Receptor on Interleukin-6 Synthesis in Human Skin Fibroblasts
1996
Abstract In this study the ability of soluble interleukin-6 receptor (sIL-6R) to stimulate interleukin-6 (IL-6) synthesis in human fibroblasts is described. It was found that sIL-6R, in combination with endogenous or exogenous IL-6, markedly upregulated IL-6 synthesis. These data suggest that increased IL-6 production after stimulation by either interleukin-1 or tumor necrosis factor-α would result in complex formation with sIL-6R, rapid uptake, and further synthesis of this cytokine. Furthermore, it would explain the decrease in sIL-6R plasma levels observed in patients suffering from sepsis.
Usefulness of Cerebral Oximetry in TBI by NIRS
2021
Measurement of cerebral oximetry by near-infrared spectroscopy provides continuous and non-invasive information about the oxygen saturation of haemoglobin in the central nervous system. This is especially important in the case of patients with traumatic brain injuries. Monitoring of cerebral oximetry in these patients could allow for the diagnosis of inadequate cerebral oxygenation caused by disturbances in cerebral blood flow. It could enable identification of episodes of hypoxia and cerebral ischemia. Continuous bedside measurement could facilitate the rapid diagnosis of intracranial bleeding or cerebrovascular autoregulation disorders and accelerate the implementation of treatment. Howev…