Search results for " enzyme"
showing 10 items of 791 documents
An overview of the traditional and innovative approaches for pectin extraction from plant food wastes and by-products: Ultrasound-, microwaves-, and …
2018
Abstract Background A large amount of food wastes and by-products are produced from farm to plate. They represent valuable sources for the production of high-added value compounds such as pectin. Pectin is the methylated ester of polygalacturonic acid and presents a wide range of applications in pharmaceutical and cosmetic products as well as in food industry such as gelling agent in fruit-based products, stabilizer in fruit and milk beverages and fruit filling for bakery and confectionary products, among others. Therefore, pectin recovery is of great importance. Scope and Approach The commercially available pectin is almost exclusively derived from citrus peels or apple pomace, by-products…
Effect of cytochrome P450 inhibitors (diethyl dithiocarbamate, ketoconazole and grapefruit juice) on the pharmacokinetics of all-trans-retinoic acid.
2004
Diethyl dithiocarbamate (DEDTC) has been reported to be a more powerful inhibitor of all-trans-retinoic acid (ATRA) in vitro metabolism than the well-established cytochrome P450 (CYP) inhibitor ketoconazole (KC). In recent years grapefruit juice (GJ) has been shown to be able to increase the oral bioavailability of several drugs by inhibiting intestinal CYP. This study investigated the in vivo effect of these CYP inhibitors on the pharmacokinetics of ATRA. The latter was administered to rats as a constant-rate intravenous (i.v.) infusion (0.48 mg h(-1) kg(-1)) during 10 h and orally (1.6 mg kg(-1)). DEDTC (320 mg kg(-1) x 2 i.v., 6.4 and 32 mg kg(-1) per os (p.o.)) did not change the ATRA c…
Structural diversity and enzyme activity of volcanic soils at different stages of development and response to experimental disturbance
2008
We investigated the phospholipid fatty acid (PLFA) diversity and enzyme activities in soils from the volcano, Mt. Etna (Sicily). The soils were at sites which have been developing for different periods of time and have formed in volcanic lava of differing ages that have been supplemented with volcanic ejecta from subsequent eruptions. However, the plant communities indicated a marked successional difference between the sites and we have used this as a proxy for developmental stage. We have compared the structural and functional properties of the microbial communities in soils from the two sites and tested experimentally the hypothesis that the more diverse community was more resistant and r…
Angiopoietin-2 plasma dosage predicts time to first treatment and overall survival in chronic lymphocytic leukemia.
2010
Abstract The clinical relevance of angiopoietin-2 (Ang2) in chronic lymphocytic leukemia (CLL) was previously suggested by the association between high Ang2, and shorter progression-free survival reported in small series of patients. Here, we evaluated Ang2 glycoprotein levels in plasma samples collected from a multicentric cohort of CLL patients (n = 316) using an enzyme-linked immunosorbent assay method, and we investigated its prognostic role in relation to time to first treatment (TTFT) and overall survival. Based on a cutoff equal to 2459 pg/mL, we divided our cohort in 2 subsets (high and low Ang2) composing 100 (31.6%) and 216 (68.4%) patients, respectively. High Ang2 was predictive …
Prolonging in utero-like oxygenation after birth diminishes oxidative stress in the lung and brain of mice pups☆
2013
Background Fetal-to-neonatal transition is associated with oxidative stress. In preterm infants, immaturity of the antioxidant system favours supplemental oxygen-derived morbidity and mortality. Objectives To assess if prolonging in utero-like oxygenation during the fetal-to-neonatal transition limits oxidative stress in the lung and brain, improving postnatal adaptation of mice pups. Material and methods Inspiratory oxygen fraction (FiO2) in pregnant mice was reduced from 21% (room air) to 14% (hypoxia) 8–12 h prior to delivery and reset to 21% 6–8 h after birth. The control group was kept at 21% during the procedure. Reduced (GSH) and oxidized (GSSG) glutathione and its precursors [γ-glut…
Seminar 2_Clinical Enzimology
2022
Este documento ha sido revisado por el Servicio de política Linguística. Su labor ha sido muy importante para la correción del documento. Este documento contiene un pdf con las diapositivas utilizadas para el seminario 2, dentro de la asignatura de Integración de Bioquímica y Biología Molecular, para los alumnos de 2º curso del grado de Medicina. El seminario habla de los ensayos clínicos realizados en sangre, del valor diagnóstico de determinadas activades enzimáticas, y como realizar correctamente un análisis de sangre. Una segunda parte de este seminario trata sobre las isoenzimas. This document contains a pdf with the slides used for the seminar 2, within the subject of Integration of B…
Cytochrome-P450 phosphorylation as a functional switch
2002
Xenobiotic metabolizing cytochromes P450 (CYP) were shown to be phosphorylated in vitro (using purified protein kinases together with purified CYPs), in intact cells (in V79 cells after transfection of cDNAs coding for individual CYPs, in diagnostic mutants, in hepatocytes), and in whole organisms (rats). CYP phosphorylation is highly isoenzyme selective in that only some CYPs are phosphorylated. Protein kinase A (PKA) was identified as a major catalyst for the phosphorylation of CYPs. The PKA recognition motif Arg-Arg-X-Ser is present in several members of the CYP2 family, but is used by only some of them, most notably by CYP2B1/2B2 and CYP2E1. For CYP2B1 it was shown that a substantial po…
In Vitro and In Vivo Regulation of SRD5A mRNA Expression of Supercritical Carbon Dioxide Extract from Asparagus racemosus Willd. Root as Anti-Sebum a…
2022
Oily skin from overactive sebaceous glands affects self-confidence and personality. There is report of an association between steroid 5-alpha reductase gene (SRD5A) expression and facial sebum production. There is no study of the effect of Asparagus racemosus Willd. root extract on the regulation of SRD5A mRNA expression and anti-sebum efficacy. This study extracted A. racemosus using the supercritical carbon dioxide fluid technique with ethanol and investigated its biological compounds and activities. The A. racemosus root extract had a high content of polyphenolic compounds, including quercetin, naringenin, and p-coumaric acid, and DPPH scavenging activity comparable to that of the standa…
Sulfur transfer and activation by ubiquitin-like modifier system Uba4•Urm1 link protein urmylation and tRNA thiolation in yeast.
2017
Urm1 is a unique dual-function member of the ubiquitin protein family and conserved from yeast to man. It acts both as a protein modifier in ubiquitin-like urmylation and as a sulfur donor for tRNA thiolation, which in concert with the Elongator pathway forms 5-methoxy-carbonyl-methyl-2-thio (mcm5s2) modified wobble uridines (U34) in anticodons. Using Saccharomyces cerevisiae as a model to study a relationship between these two functions, we examined whether cultivation temperature and sulfur supply previously implicated in the tRNA thiolation branch of the URM1 pathway also contribute to proper urmylation. Monitoring Urm1 conjugation, we found urmylation of the peroxiredoxin Ahp1 is suppre…
Oxidative Stress and DNA Damage in Human Gastric Carcinoma: 8-Oxo-7'8-dihydro-2'-deoxyguanosine (8-oxo-dG) as a Possible Tumor Marker
2013
We characterized the oxidative stress (OS) status by the levels of reduced/oxidized glutathione (GSH/GSSG), malondialdehyde (MDA) and the mutagenic base 8-oxo-7'8-dihydro-2'-deoxyguanosine (8-oxo-dG) in human gastric carcinoma (HGC) samples and compared the results with normal tissue from the same patients. We also analyzed 8-oxo-dG in peripheral mononuclear cells (PMNC) and urine from healthy control subjects and in affected patients in the basal state and one, three, six, nine and twelve months after tumor resection. The levels of DNA repair enzyme mRNA expression (hOGG1, RAD51, MUYTH and MTH1) were determined in tumor specimens and compared with normal mucosa. Tumor specimens e…