Search results for "ATP"
showing 10 items of 736 documents
Effects of controlled-release on the pharmacokinetics and absorption characteristics of a compound undergoing intestinal efflux in humans
2006
Abstract Objective The number of active pharmaceutical ingredients (API) undergoing inhibitable and saturable intestinal efflux is considerable. As a consequence, absorption and bioavailability may depend on the intestinal concentration profile of the drug and may vary as a function of dose and release rate of the drug from the dosage form. The impact of controlled versus immediate-release on the absorption of P-glycoprotein substrates is currently unknown. Thus, the main focus of the present study was a comparison of the pharmacokinetics of the P-gp model substrate talinolol following administration of immediate-release (IR) and controlled-release (CR) tablets to healthy human volunteers w…
Familial hemiplegic migraine type 2 is linked to 0.9Mb region on chromosome 1q23
2003
Familial hemiplegic migraine (FHM) is a rare autosomal dominant disorder characterized by episodes of transient hemiparesis followed by headache. Two chromosomal loci are associated to FHM: FHM1 on chromosome 19 and FHM2 on chromosome 1q21-23. Mutations of the alpha-1A subunit of the voltage gated calcium channel (CACNA1A) are responsible for FHM1. FHM2 critical region spans 28 cM, hence hampering the identification of the responsible gene. Here, we report the FHM2 locus refining by linkage analysis on two large Italian families affected by pure FHM. The new critical region covers a small area of 0.9Mb in 1q23 and renders feasible a positional candidate approach. By mutation analysis, we ex…
Correlation between GP-170 expression, prognosis, and chemoresistance of superficial bladder carcinoma.
2003
To study GP-170 in superficial bladder cancer at initial diagnosis and at recurrence and to evaluate if intravesical chemoprophylaxis modifies the expression of GP-170 in tumor recurrences. GP-170 was retrospectively assessed in 160 patients affected by primary superficial transitional cell carcinoma of the bladder and followed for up to 10 years. Eighty-four patients (52.5%) recurred after transurethral resection (TUR). Adjuvant intravesical chemotherapy after TUR was adopted in 52 patients. The correlations between GP-170 and G-grade, T-category, risk of recurrence and of progression, and adoption of adjuvant intravesical chemotherapy were investigated. The correlations between variations…
Effect of ouabain and furosemide on erythrocyte sodium and phosphate transport.
1981
The effects of ouabain and furosemide on the unidirectional efflux of sodium and phosphate ions were studied in freshly drawn human red blood cells (RBCs). In the presence of physiologic concentrations of sodium and potassium the rate of sodium efflux was reduced by 74% due to ouabain sensitivity. Furosemide (1.0 mmol/l) reduced ouabain-insensitive sodium transport rate by a further 50%. Thus, 13% of total sodium efflux was inhibited by furosemide when ouabain was present. In the absence of ouabain, however, furosemide inhibited 31% of total sodium transport, indicating that it also affected ouabain-sensitive sodium efflux. Phosphate transfer of RBCs was almost 1.0 mmol/l RBCs per hour. Ery…
Dietary polyunsaturated fatty acids may increase plasma LDL-cholesterol and plasma cholesterol concentrations in carriers of an ABCG1 gene single nuc…
2011
Abstract Background ABCG1 mediates cellular cholesterol transport, but there is very little known about the influence of ABCG1 polymorphisms on human plasma lipoprotein cholesterol concentrations or on the interactions of these polymorphisms with diet. Objective Our objective was to investigate whether interactions between PUFA intake and ABCG1 polymorphisms modulate associations with plasma total cholesterol (TC), LDL- and HDL-cholesterol in two Spanish populations. Methods We grounded our investigation on two general population-based studies: the Hortega study (population A) and the Pizarra study (population B). Participants included 1178 individuals (50.0% women, age range 21–85 years) a…
Influence of ABCB1 polymorphisms upon the effectiveness of standard treatment for acute myeloid leukemia: A systematic review and meta-analysis of ob…
2015
The ABCB1 gene encodes for P-glycoprotein (P-gp), an efflux pump for a variety of xenobiotics. The role of ABCB1 polymorphisms in acute myeloid leukemia (AML) outcomes of standard chemotherapy (cytarabine plus anthracyclines) remains controversial. A systematic search was made of studies evaluating the association between ABCB1 polymorphisms 1236C>T, 2677G>T/A and 3435C>T and effectiveness variables. We found seven cohort studies (1241 patients) showing a significantly higher overall survival (OS) among carriers of the variant allele of 1236C>T at year 4 (odds ratio (OR): 1.47, 95% confidence interval (CI): 1.07-2.01), 2677G>T/A at years 4-5 (OR: 1.37, 95% CI: 1.01-1.86) and 3435C>T at year…
Lack of efficacy of mitoxantrone in primary progressive Multiple Sclerosis irrespective of pharmacogenetic factors: A multi-center, retrospective ana…
2014
Abstract Background Mitoxantrone is used on an off-label basis in primary progressive MS (PPMS). ABC -transporter-genotypes are associated with therapeutic response in relapsing/secondary progressive MS (RP/SPMS). Objective To evaluate potential pharmacogenetic response markers for mitoxantrone in PPMS. Methods 41 mitoxantrone-treated PPMS-patients, 155 mitoxantrone-treated RP/SPMS-patients and 43 PPMS-controls were retrospectively assessed for clinical therapy-response and in correlation with four single-nucleotide-polymorphisms in ABCB1 - and ABCG2 -genes. Results 53.7% PPMS-patients were mitoxantrone-responders, in comparison to 78.1% of RP/SPMS-patients (p = 0.039). There was no associa…
Defects in the Human Leukocyte Antigen Class I Antigen Processing Machinery in Head and Neck Squamous Cell Carcinoma: Association with Clinical Outco…
2005
AbstractPurpose: Human leukocyte antigen (HLA) class I antigen defects, which are frequently present in head and neck squamous cell carcinoma (HNSCC) cells may provide the tumor with an escape mechanism from immune surveillance. Scanty information is available about mechanisms underlying HLA class I antigen defects in both lesions and cell lines from HNSCC. In this study, we investigate the role of antigen processing machinery (APM) component abnormalities in the generation of deficient HLA class I surface expression of HNSCC cells.Experimental Design: Using immunohistochemistry, Western blot, and RT-PCR analyses we correlated the expression of the IFN-γ inducible proteasome subunits and of…
Influence of CYP3A5 and ABCB1 gene polymorphisms and other factors on tacrolimus dosing in Caucasian liver and kidney transplant patients
2011
Tacrolimus is a substrate of cytochrome P4503A (CYP3A) enzymes as well as of the drug transporter ABCB1. We have investigated the possible influence of CYP3A5 and ABCB1 single nucleotide polymorphisms (SNPs) and other factors (e.g. albumin, hematocrit and steroids) on tacrolimus blood levels achieved in a population of Caucasian liver (n=51) and kidney (n=50) transplant recipients. At 1, 3 and 6 months after transplantation, tacrolimus doses (mg/kg/day) and trough blood levels (C0) were recorded and the weight-adjusted tacrolimus dosage (mg/kg/day) was calculated. Polymerase chain reaction followed by restriction fragment length polymorphism analysis was used for genotyping CYP3A5*1 and *3 …
Role of Ca2+-activated K+ channels and Na+,K+-ATPase in prostaglandin E1- and E2-induced inhibition of the adrenergic response in human vas deferens
2011
We studied the role of K(+) channels and Na(+),K(+)-ATPase in the presynaptic inhibitory effects of prostaglandin E(1) (PGE(1)) and PGE(2) on the adrenergic responses of human vas deferens. Furthermore, we determined the effects of increasing extracellular K(+) concentrations ([K(+)](o)) and inhibition of Na(+),K(+)-ATPase on neurogenic and norepinephrine-induced contractile responses. Ring segments of the epididymal part of the vas deferens were taken from 45 elective vasectomies and mounted in organ baths for isometric recording of tension. The neuromodulatory effects of PGEs were tested in the presence of K(+) channel blockers. PGE(1) and PGE(2) (10(-8) to 10(-6)M) induced inhibition of …