Search results for "HOF"
showing 10 items of 271 documents
Biophysical Characterization of Polysialic Acid—Membrane Nanosystems
2019
Polysialic acid (polySia) is a long, membrane-bound, polyanionic polymer (with the degree of polymerization, DP, up to 400) of negatively charged sialic acid monomers. Biological roles of polySia are based on its ability to modulate repulsive and attractive interactions, and its ability to modulate membrane surface charge density, pH at the membrane surface, and membrane potentials. PolySia is used in anti-bacterial and anti-cancer therapies, and in neural tissue repair. Hydrophobically-modified polySia chains can form nano-structures (micelles or liposomes) with high stability and low toxicity for drug delivery. The analysis, based on the Goldman-Hodgkin-Katz equation, of transmembrane pot…
Induction of cytochrome P450 isoenzymes in cultured precision-cut rat and human liver slices
1996
1. The effect of some xenobiotics on levels of selected cytochrome P450 (CYP) isoenzymes determined by Western immunoblotting and associated enzyme activities has been studied in 72-h cultured rat and human precision-cut liver slices. 2. In cultured rat liver slices, 0.5 mM sodium phenobarbitone (PB), 25 microM beta-naphthoflavone (BNF), and 20 micrograms/ml Aroclor 1254 (ARO) induced mixed-function oxidase enzyme activities. Western immunoblotting of liver slice microsomes was performed with antibodies to rat CYP1A2, 2B1/2 and 3A. Compared with 72-h control (dimethyl sulphoxide only treated) rat liver slice microsomes, PB induced CYP2B1/2 and 3A, BNF induced CYP1A2, and ARO induced CYP1A2,…
Regulatory properties of 6-phosphofructokinase and control of glycolysis in boar spermatozoa.
2007
Glycolysis is crucial for sperm functions (motility and fertilization), but how this pathway is regulated in spermatozoa is not clear. This prompted to study the location and the regulatory properties of 6-phosphofructokinase (PFK, EC 2.7.1.11), the most important element for control of glycolytic flux. Unlike some other glycolytic enzymes, PFK showed no tight binding to sperm structures. It could readily be extracted from ejaculated boar spermatozoa by sonication and was then chromatographically purified. At physiological pH, the enzyme was allosterically inhibited by near-physiological concentrations of its co-substrate ATP, which induced co-operativity, i.e. reduced the affinity for the …
The cytotoxicity of mitomycin C and Adriamycin in genetically engineered V79 cell lines and freshly isolated rat hepatocytes
1995
The objective of the present study was to investigate the cytotoxicity of Adriamycin (ADR) and mitomycin C (MMC) in tumor and non-tumor cells with respect to the role of cytochrome P450 (P450). Therefore, genetically engineered V79 Chinese hamster fibroblasts expressing only single enzymes of P450 were used. SD1 and XEM2 cells expressed rat P450IIB1 and P450IA1, respectively, whereas the V79 parental cells contained no detectable P450 levels. The cytotoxicity of ADR and MMC in the V79 cell system was compared with that in freshly isolated hepatocytes from phenobarbital (PB-hepatocytes)- and beta-naphthoflavone (beta NF-hepatocytes)-induced rats. Following 24 h of exposure to ADR equal cytot…
Thalamic hyperdensity — is it a diagnostic marker for Sandhoff disease?
1993
Sandhoff disease, also known as GM2-gangliosidoses variant 0, is caused by the deficient activity of both hexosaminidase A and hexosaminidase B. We report a 15-month-old boy diagnosed with Sandhoff disease by demonstrating the enzyme deficiency. The interesting finding was bilateral thalamic hyperdensity on the CT scan. The hyperdensity in all previously published cases was homogeneous and symmetric and limited to the thalamus; the cause still remains unknown. We suggest that the finding of dense thalami may be useful as a specific diagnostic criterion for the GM2-gangliosidoses and especially for Sandhoff disease.
Individual analysis of patients with HoFH participating in a phase 3 trial with lomitapide: The Italian cohort
2015
Abstract Background and aims The efficacy and safety of lomitapide as adjunct treatment for adults with homozygous familial hypercholesterolaemia (HoFH) have been confirmed in a phase 3 trial. Given the small number of patients (N = 29), and variations in patient characteristics, examining individual cases provides additional details regarding patient management with lomitapide. Here, we examine the details of the Italian patient cohort in the phase 3 trial. Methods and results The methodology of the multinational, single-arm, open-label, 78-week, dose-escalation, phase 3 trial has been previously reported. The current report details the Italian cohort of six patients (three males, three fe…
Plantar flexor activation capacity and H reflex in older adults: adaptations to strength training.
2002
The purpose of this study was to investigate whether the voluntary neural drive and the excitability of the reflex arc could be modulated by training, even in old age. To this aim, the effects of a 16-wk strengthening program on plantar flexor voluntary activation (VA) and on the maximum Hoffman reflex (Hmax)-to-maximum M wave (Mmax) ratio were investigated in 14 elderly men (65–80 yr). After training, isometric maximum voluntary contraction (MVC) increased by 18% ( P < 0.05) and weight-lifting ability by 24% ( P < 0.001). Twitch contraction time decreased by 8% ( P < 0.01), but no changes in half relaxation time and in peak twitch torque were observed. The VA, assessed by twitch …
Effects of age and life-time physical training on fibre composition of slow and fast skeletal muscle in rats.
1987
The effects of age and endurance training on muscle fibre characteristics were studied in a slow (m. soleus, MS) and in a fast (m. rectus femoris, MRF) skeletal muscle. Wistar rats at ages of 1, 2, 4, 10, and 24 months were used as experimental animals. The trained rats were put to run on a motor-driven treadmill 5 d/wk beginning from the age of 1 month. The body weights of the animals increased continuously throughout their lives. The muscle weights increased up to the age of 10 months, after which they tended to decrease. The trained adult rats had lower body weights as well as lower muscle weights than the untrained adult rats. The amount of the intramuscular lipid decreased with age, es…
Antagonistic effects of hypertrehalosemic neuropeptide on the activities of 6-phosphofructo-1-kinase and fructose-1,6-bisphosphatase in cockroach fat…
2001
Hypertrehalosemic neuropeptides from the corpora cardiaca such as the decapeptide Bld HrTH bring about a profound switch in the metabolic activity of cockroach fat body during which production of the blood sugar trehalose is stimulated while the catabolism of carbohydrate (glycolysis) is inhibited. The mechanisms of the metabolic switch are not fully understood. Incubation of isolated fat body from the cockroach Blaptica dubia with 10(-8) M Bld HrTH, for 10-60 min, stimulated glycogen breakdown and increased the content of the substrates of both the glycolytic enzyme 6-phosphofructo-1-kinase (PFK, EC 2.7.1.11) and the gluconeogenic enzyme fructose-1,6-bisphosphatase (FBPase, EC 3.1.3.11) in…
Effect of chronic exercise on glucose uptake and activities of glycolytic enzymes measured regionally in rat heart.
1989
Regional glucose uptake in perfused hearts, and the activities of several glycolytic enzymes contributing to the glucose metabolism in perfused and nonperfused hearts were studied in male and female rats after 8–9 weeks of swimming training. The left ventricular glucose uptake showed a transmural gradient in the sedentary animals, the subendocardial uptake being 30% and 12% higher than that of the subepicardial layer in the males and females, respectively. Swimming exercise abolished the left ventricular glucose uptake gradient in male rats, and in female rats an opposite gradient was found, the subepicardial uptake being 23% higher than the subendocardial uptake. The activities of phosphof…