Search results for "Enzyme Assay"
showing 10 items of 155 documents
Cytochrome P-450 mRNA expression in human liver and its relationship with enzyme activity.
2001
CYP activity and protein contents have been measured in human liver using different techniques. In contrast, CYP mRNA data are scarce and the relationships between CYP mRNA contents and activities have not been established. These studies deserve further attention because mRNA determinations by RT-PCR require a very small amount of material (e.g., liver needle biopsy) and could provide important data regarding CYP expression regulation. In this study we measured in 12 human liver samples the mRNA contents of 10 CYPs by quantitative RT-PCR and the metabolic activities using specific substrates. mRNA contents and activities showed high correlation coefficients for CYP1A1, CYP1A2, CYP3A4, CYP2D…
Retinol oxidation to retinoic acid in human thyroid glandular cells.
2014
Abstract Retinoic acid is regarded as the retinol metabolite that controls proliferation and differentiation of epithelial cells. In the present study, we investigated the potential role of xanthine dehydrogenase (XDH) in retinoic acid biosynthesis in human thyroid glandular cells (HTGC). In particular, we observed that cellular retinoids binding proteins (CRBPs) are also implicated in the biosynthetic pathway leading to retinoic acid formation in primary cultures of HTGC, as we have already reported for human mammary epithelial cells (HMEC). After partial protein purification, the enzyme responsible for retinoic acid biosynthesis was identified and quantified as XDH by immunoassay, by its …
Relationship Between Glucocerebrosidase Activity and Clinical Response to Enzyme Replacement Therapy in Patients With Gaucher Disease Type I
2018
The quantification of enzyme activity in the patient treated with enzyme replacement therapy (ERT) has been suggested as a tool for dosage individualization, so we conducted a study to evaluate the relationship between glucocerebrosidase activity and clinical response in patients with Gaucher disease type I (GD1) to ERT. The study included patients diagnosed with GD1, who were being treated with ERT, and healthy individuals. Markers based on glucocerebrosidase activity measurement in patients' leucocytes were studied: enzyme activity at 15 min. post-infusion (Act75 ) reflects the amount of enzyme that is distributed in the body post-ERT infusion, and accumulated glucocerebrosidase activity …
Sulfatide excreting heterozygous carrier of juvenile metachromatic leukodystrophy or asymptomatic patient of adult metachromatic leukodystrophy.
1975
In a family with juvenile metachromatic leukodystrophy (sulfatide lipidosis) 2 patients showed residual arysulfatase A activities of 5--6%. The patients' healthy father was characterized biochemically by a 39% normal activity of leukocyte plus plasma arylsulfatase A. The father was further characterized by a high sulfatide excretion (0.2--0.5 mg/I urine) and, paradoxically, by a normal sulfatide degrading enzyme activity in vitro. This special carrier is suspected to be heterozygous for a) arylsulfatase A deficiency and b) arylsulfatase A (sulfatidase) lability. This presumed additional genetic defect could be the cause of the sulfatide excretion which, in turn, would be a sign of the precl…
Heterogeneity of Morquio disease.
1986
Further clinical heterogeneity of Morquio disease, mucopolysaccharidosis IV (MPS IV), is delineated by the observation of a 30-year-old man with unusually mild clinical manifestations. He is 156 cm tall, has comparatively mild skeletal abnormalities and fine corneal deposits. Keratosulfaturia is absent. N-Acetylgalactosamine-6-sulfate (GalNAc-6-S) sulfatase (E.C. 3.1.6.-) was markedly reduced in his fibroblasts. The residual enzyme activity exhibited a pH profile comparable to that of patients with the "classical" form of the disorder. From our observation and a review of the literature it is concluded that Morquio disease can be divided in several subgroups: besides the severe ("classical"…
Identification of glyoxalase 1 polymorphisms associated with enzyme activity.
2013
The glyoxalase system and its main enzyme, glyoxalase 1 (GLO1), protect cells from advanced glycation end products (AGEs), such as methylglyoxal (MG) and other reactive dicarbonyls, the formation of which is increased in diabetes patients as a result of excessive glycolysis. MG is partly responsible for harmful protein alterations in living cells, notably in neurons, leading to their dysfunction, and recent studies have shown a negative correlation between GLO1 expression and tissue damage. Neuronal dysfunction is a common diabetes complication due to elevated blood sugar levels, leading to high levels of AGEs. The aim of our study was to determine whether single nucleotide polymorphisms (S…
Development and application to clinical practice of a validated HPLC method for the analysis of β-glucocerebrosidase in Gaucher disease.
2014
The main objective of our study is to develop a simple, fast and reliable method for measuring ß-glucocerebrosidase activity in Gaucher patients leukocytes in clinical practice. This measurement may be a useful marker to drive dose selection and early clinical decision making of enzyme replacement therapy. We measure the enzyme activity by high-performance liquid chromatography with ultraviolet detection and 4-nitrophenyl-ß-d-glucopyranoside as substrate. A cohort of eight Gaucher patients treated with enzyme replacement therapy and ten healthy controls were tested; median enzyme activity values was 20.57mU/ml (interquartile range 19.92-21.53mU/ml) in patients and mean was 24.73mU/ml (24.12…
Polymorphisms in the SCD1 gene are associated with indices of stearoyl CoA desaturase activity and obesity: a prospective study.
2013
Scope The serum fatty acid (FA) composition is influenced by dietary fat and the endogenous production of FAs. Stearoyl CoA desaturase 1 (SCD1) is the rate-limiting enzyme catalyzing the synthesis of MUFAs from saturated FAs. Variations in SCD1 activity have been associated with obesity, diabetes, or inflammation. We evaluated the associations between genetic variation of the SCD1 gene, SCD1 activity, intake of oil, and obesity in a population-based prospective study in southern Spain. Methods and results We collected phenotypic, metabolic, nutritional, and genetic information. The type of dietary fat was assessed from samples of cooking oil taken from the participants’ kitchens and analyze…
Ultra-long-distance running and the liver.
1990
During an ultra-long-distance race (1000 km in 20 days) the influence of running was examined on the enzymes aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (AP), gamma-glutamyl-transferase (GGT), and glutamate dehydrogenase (GLDH) with regard to their release from the liver cells or their induction. Furthermore the liver synthetic capacity was assayed by measuring the enzyme activity of cholinesterase and the concentration of serum albumin during the race. Of the 110 participants, 55 finished the race and only the results of these runners were used in our study. AP increased continuously from day 0 (mean = 102 U/L) to day 19 (mean = 120 U/L). A fivefo…
Vitiligo susceptibility and catalase gene (CAT) polymorphisms in sicilian population
2018
BACKGROUND Catalase gene (CAT) polymorphisms were analyzed as responsible for the deficiency of catalase enzyme activity and concomitant accumulation of excessive hydrogen peroxide in vitiligo patients. Catalase is a well-known oxidative stress regulator that could play an important role in the pathogenesis of vitiligo. This study was conducted to evaluate three CAT gene polymorphisms (-89A/T, 389C/T, 419C/T) and their association with vitiligo susceptibility in Sicilian population. METHODS Sixty out of 73 Sicilian patients with vitiligo were enrolled and submitted to CAT gene analysis. RESULTS Contrary to the Northern part of Europe but likewise to the Mediterranean area, the frequency of …