Search results for "Biochemistry"
showing 10 items of 20172 documents
Managing Persistent Hypoxemia: what is new?
2017
Mechanical ventilation is the standard life-support technique for patients with severe acute respiratory failure. However, some patients develop persistent and refractory hypoxemia because their lungs are so severely damaged that they are unable to respond to the application of high inspired oxygen concentration and high levels of positive end-expiratory pressure. In this article, we review current knowledge on managing persistent hypoxemia in patients with injured lungs.
Cholesterol as stabilizer of the oxytocin receptor
2002
AbstractThe function of the oxytocin receptor system is strongly dependent on steroids as demonstrated by several physiological studies. One key element of this dependence on steroids may be the interaction of cholesterol and the oxytocin receptor. In this study, we show that cholesterol stabilizes the solubilized human oxytocin receptor against thermal inactivation and proteolytic degradation. In the absence of additional cholesterol, the soluble receptor inactivates within minutes. Maximal stabilization of the oxytocin receptor requires a continuous supply with cholesterol from a cholesterol-rich environment. A structure–activity analysis of various cholesterol analogues and their effect …
Thrombolytic therapy for submassive pulmonary embolism.
2012
Approximately 10% of all patients with acute pulmonary embolism (PE) die within the first three months after diagnosis. However, PE is not universally life-threatening, but covers a wide spectrum of clinical severity and death risk. Thrombolytic treatment is indicated patients with acute massive PE who are at high risk for early death, i.e. those patients who present with arterial hypotension and shock. On the other hand, low molecular-weight heparin or fondaparinux is adequate treatment for most normotensive patients with PE. Recombinant tissue plasminogen activator, given as 100 mg infusion over 2 h, is the treatment of choice for patients with PE, although older regimens using urokinase …
Mitochondrial complex I impairment in leukocytes from type 2 diabetic patients.
2011
Diabetes is associated with oxidative stress. This study evaluated the rates of oxidative stress and mitochondrial impairment in type 2 diabetes patients. The study population consisted of 182 diabetic patients and 50 body-composition- and age-matched controls. We assessed anthropometric and metabolic parameters and mitochondrial function by evaluating mitochondrial oxygen (O2) consumption, reactive oxygen species (ROS) production, glutathione (GSH) levels, GSH/GSSG ratio, mitochondrial membrane potential, and mitochondrial complex I activity in polymorphonuclear cells from diabetes type 2 patients. We found an increase in waist circumference and augmented serum levels of triglycerides, pro…
Cholesterol accumulation is increased in macrophages of phospholipid transfer protein-deficient mice: normalization by dietary alpha-tocopherol suppl…
2007
Objective— Phospholipid transfer protein (PLTP) is a multifunctional, extracellular lipid transport protein that plays a major role in lipoprotein metabolism and atherosclerosis. Recent in vivo studies suggested that unlike systemic PLTP, macrophage-derived PLTP would be antiatherogenic. The present study aimed at characterizing the atheroprotective properties of macrophage-derived PLTP. Methods and Results— Peritoneal macrophages were isolated from PLTP-deficient and wild-type mice and their biochemical characteristics were compared. It is shown that macrophages isolated from PLTP-deficient mice have increased basal cholesterol content and accumulate more cholesterol in the presence of LD…
Comparative study of post-natal retinal vascular development in mice models of iPLA2 inhibition and plasmalogen deficiency
2012
Purpose: Plasmalogens are particular phospholipids characterized by the presence of a vinyl-ether bond and of a polyunsaturated fatty acid (PUFA) at sn-1 and sn-2 positions of glycerol, respectively. Even if the plasmalogen content of organs and tissues is well documented, their biological functions are still enigmatic. Plasmalogen deficiency in DAPAT-/- mice leads to developmental abnormalities in retinal vasculature (Acar et al, ARVO 2007 E-Abstract 2978) and to persistent hyaloïd arteries. We hypothesize that plasmalogens regulate retinal vascular development through the liberation of PUFA by a plasmalogen-specific calcium-independent phospholipase A2 (iPLA2). We have performed a compara…
Inflammation et immunité : implications dans l’obésité et le diabète de type 2
2006
The evidences have been increasingly accumulated on the implication of inflammatory mediators like tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in the pathological states related to insulin resistance like obesity, type 2 diabetes and atherosclerosis. There seems a link between insulin resistance and these pro-inflammatory agents, secreted by macrophages and adipocytes. Th (helper) cells are differentiated into either Th1 or Th2 phenotypes. It is generally considered that Th1 phenotype is pro-inflammatory whereas Th2 phenotype exerts anti-inflammatory (protective) effects. The upregulation of Th1 phenotype may aggravate these pathologies. One of the adipokines, i.e., adiponectin…
Magnetic Resonance Imaging Derived Biomarkers of IDH Mutation Status and Overall Survival in Grade III Astrocytomas
2020
The evaluation of the isocitrate dehydrogenase (IDH) mutation status in the glioma decision-making process has diagnostic, prognostic and therapeutic implications. The aim of this study was to evaluate whether conventional magnetic resonance imaging (MRI) and apparent diffusion coefficient (ADC) can noninvasively predict the most common IDH mutational status (R132H) in GIII-astrocytomas and the overall survival (OS). Hence, twenty-two patients (9-F, 13-M) with a histological diagnosis of GIII-astrocytoma and evaluation of IDH-mutation status (12-wild type, 10-mutant) were retrospectively evaluated. Imaging studies were reviewed for the morphological feature and mean ADC values (ADCm). Stati…
Gender-Specific Metabolomics Approach to Kidney Cancer
2021
Renal cell carcinoma (RCC) is the most common form of kidney malignancy. RCC is more common among men with a 2/1 male/female incidence ratio worldwide. Given the underlying epidemiological differences in the RCC incidence between males and females, we explored the gender specific 1H NMR serum metabolic profiles of RCC patients and their matched controls. A number of differential metabolites were shared by male and female RCC patients. These RCC specific changes included lower lactate, threonine, histidine, and choline levels together with increased levels of pyruvate, N-acetylated glycoproteins, beta-hydroxybutyrate, acetoacetate, and lysine. Additionally, serum lactate/pyruvate ratio was a…
Cholesterol and ocular pathologies: focus on the role of cholesterol-24S-hydroxylase in cholesterol homeostasis
2015
The retina is responsible for coding the light stimulus into a nervous signal that is transferred to the brain via the optic nerve. The retina is formed by the association of the neurosensory retina and the retinal pigment epithelium that is supported by Bruch’s membrane. Both the physical and metabolic associations between these partners are crucial for the functioning of the retina, by means of nutrient intake and removal of the cell and metabolic debris from the retina. Dysequilibrium are involved in the aging processes and pathologies such as age-related macular degeneration, the leading cause of visual loss after the age of 50 years inWestern countries. The retina is composed of severa…