RÉSUMÉ
The analysis of surgical care administration to personnel, serving on ships of the Navy of Russia and performing different tasks in off-shore maritime and ocean zones in 2012-2013 showed that there is a requirement to create seven additional ship groups of specialized medical care: on the Northern Fleet--2, on the Pacific Fleet--2, on the Baltic Fleet--1, on the Black Sea Fleet--1, on the Caspian Flotilla--1. There is also a reasonable requirement to include anaesthesiologist and nurse anaesthetist into these groups.
Sujet(s)
Traumatismes de l'abdomen/chirurgie , Médecine militaire/méthodes , Personnel militaire , Médecine navale/méthodes , Procédures de chirurgie opératoire/méthodes , Humains , Mâle , Médecine militaire/normes , Médecine navale/normes , Russie , Procédures de chirurgie opératoire/normesRÉSUMÉ
The elastic phase transitions of cubic metals at high pressures are investigated within the framework of Landau theory. It is shown that at pressures comparable with the magnitude of the bulk modulus the phase transition is connected with the loss of stability relative to uniform deformation of the crystalline lattice. Discontinuity of the order parameter at the transition point and its equilibrium value are expressed through the second- to fourth-order elastic constants. The second-,third- and fourth-order elastic constants and phonon dispersion curves of vanadium under hydrostatic pressure are obtained by first-principles calculations. Structural transformation in vanadium under pressure is studied using the obtained results. It is shown that the experimentally observed at P ≈ 69 GPa phase transition in vanadium is the first-order phase transition close to a second-order phase transition.
RÉSUMÉ
Budesonide treatment of chronic inflammatory bowel disease commonly leads to non-response or adverse reactions, possibly because of alterations in efflux transport mediated by the ABCB1 gene product P-glycoprotein or metabolism by CYP3A isoenzymes. Two groups, each consisting of nine healthy volunteers, one with the CYP3A5(*)1/(*)3 genotype (expressors) and the other with the CYP3A5(*)3/(*)3 genotype (non-expressors), were given a single oral dose of 9 mg budesonide. Plasma and urine concentrations of budesonide and its major metabolites were determined using liquid chromatography-tandem mass spectrometry. Subsequently, rectosigmoidal biopsies were taken for analysis of messenger RNA (mRNA) expression. Budesonide pharmacokinetics did not differ between genotype groups. However, intestinal CYP3A4 expression was shown to correlate directly with partial metabolic clearances of 16-hydroxy-prednisolone (r(2) = 0.30; P = 0.010) and 6-hydroxy-budesonide (r(2) = 0.25; P = 0.016), but inversely with budesonide AUC(0-24 h) (r(2) = 0.18; P = 0.040). Interestingly, a strong correlation was found between CYP3A5 and ABCB1 expression in CYP3A5 expressors (r(2) = 0.79; P = 0.001). This study suggests that intestinal CYP3A4 expression has an impact on budesonide pharmacokinetics. Moreover, CYP3A5 and ABCB1 expression appears to be coregulated.
Sujet(s)
Glycoprotéine P/génétique , Budésonide/pharmacocinétique , Cytochrome P-450 CYP3A/génétique , Régulation de l'expression des gènes codant pour des enzymes/physiologie , Muqueuse intestinale/métabolisme , Sous-famille B de transporteurs à cassette liant l'ATP , Glycoprotéine P/biosynthèse , Administration par voie orale , Adulte , Budésonide/administration et posologie , Budésonide/sang , Cytochrome P-450 CYP3A/biosynthèse , Femelle , Régulation de l'expression des gènes codant pour des enzymes/effets des médicaments et des substances chimiques , Génotype , Humains , Absorption intestinale/effets des médicaments et des substances chimiques , Absorption intestinale/physiologie , Muqueuse intestinale/effets des médicaments et des substances chimiques , MâleRÉSUMÉ
It is currently not clear whether the concentration-time curves of the immunosuppressants differ with respect to the CYP3A5, MDR1, or MRP2 genotype in dose-adapted stable kidney transplant patients. Dose/trough concentration ratios were obtained in 134 tacrolimus and 20 sirolimus-treated patients, and plasma concentration-time profiles were obtained from 16 (tacrolimus) and 10 (sirolimus) patients. Genotyping was carried out for CYP3A5 6986A>G; ABCB1 2677G>T/A, 3435C>T and ABCC2 -24C>T; 1249G>A; 3972C>T. Dose/trough concentration ratios were 0.67+/-0.3 and 1.36+/-0.73 x 10(3) l (P<0.00001) for tacrolimus and 0.42+/-0.17 and 0.84+/-0.46 x 10(3) l (P=0.18) for sirolimus in CYP3A5 non-expressors and expressors. The unadjusted tacrolimus area under curve (AUC)(0-12) was 106.8+/-17.5 ng/ml x h compared with 133.3+/-42.2 ng/ml x h (P=0.37) without affecting serum creatinine. Mean unadjusted AUC(0-24) of sirolimus did not differ significantly either. Therefore, CYP3A5 expressor status and not transporter variants is a main determinant of oral clearance, particularly for tacrolimus. Dose adaptation according to trough levels, however, appears to be sufficient to maintain similar concentration-time profiles.
Sujet(s)
Cytochrome P-450 enzyme system/génétique , Transplantation rénale , Sirolimus/pharmacocinétique , Tacrolimus/pharmacocinétique , Adulte , Sujet âgé , Aire sous la courbe , Biodisponibilité , Inhibiteurs des canaux calciques/métabolisme , Inhibiteurs des canaux calciques/pharmacocinétique , Inhibiteurs des canaux calciques/usage thérapeutique , Cytochrome P-450 CYP3A , Cytochrome P-450 enzyme system/métabolisme , Association de médicaments , Femelle , Variation génétique , Génotype , Période , Humains , Immunosuppresseurs/métabolisme , Immunosuppresseurs/pharmacocinétique , Immunosuppresseurs/usage thérapeutique , Mâle , Adulte d'âge moyen , Protéine-2 associée à la multirésistance aux médicaments , Acide mycophénolique/analogues et dérivés , Acide mycophénolique/métabolisme , Acide mycophénolique/pharmacocinétique , Acide mycophénolique/usage thérapeutique , Prednisolone/métabolisme , Prednisolone/pharmacocinétique , Prednisolone/usage thérapeutique , Sirolimus/métabolisme , Sirolimus/usage thérapeutique , Tacrolimus/métabolisme , Tacrolimus/usage thérapeutiqueRÉSUMÉ
OBJECTIVE: Dysembryoplastic neuroepithelial tumors (DNT) are relatively benign brain lesions that often cause medically intractable epilepsy. There is mounting evidence that multidrug transporters such as P-glycoprotein (P-gp) or multidrug resistance-associated proteins (MRP) play an important role in the development of resistance to antiepileptic drugs (AED). MATERIAL AND METHODS: In the present study, we examined the expression of several multidrug transporters in 14 cases of DNT. The peritumoral brain tissue as well as 9 cases of arteriovenous malformations (AVM) served as controls. P-gp, MRP2, MRP5 and breast cancer resistance protein (BCRP) expression was evaluated qualitatively and quantitatively using immunohistochemistry. RESULTS: All transporters were overexpressed quantitatively in DNT, but each revealed a different labeling pattern. P-gp and BCRP were predominantly located in the endothelium of brain vessels. MRP5 was detected primarily in endothelial cells, but notably also in neurons. The expression of P-gp, MRP2 and MRP5 was low in AVM, whereas BCRP demonstrated strong staining. Examination of MDR1 gene polymorphisms revealed no correlation with P-gp expression whereas the MRP2 exon 10 G1249A polymorphism was associated with different MRP2 labelling. CONCLUSIONS: Our results show that multidrug transporters are overexpressed in DNT. This finding supports the view that several of these transport proteins may play an important role in the mechanisms of drug resistance in epileptic brain tissue.