170 resultados para Half-open regimen


Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND: MDL 100,240 (pyrido[2,1-a] [2]benzazepine-4-carboxylic acid,7-[[2-(acetylthio)-1-oxo-3-phenylpropyl]amino]-1,2,3,4,6,7,8, 12b-octahydro-6-oxo, [4S-[4alpha,7alpha(R(*)),12bbeta]]-) is a molecule possessing an inhibiting ability on both angiotensin converting enzyme (ACE) and neutral endopeptidase, the enzyme responsible for atrial natriuretic peptide (ANP) degradation. Such a dual mechanism of action presents a potential clinical interest for the treatment of hypertension and congestive heart failure. OBJECTIVES: To evaluate the bioavailability of MDL 100,240 and its accumulation over repeated oral administration, using ACE inhibition as a surrogate for plasma drug level and determining its profile after oral and i.v. administration. METHODS: First, in an open, one-period, single-dose study, the ACE inhibition profile was characterised following a 12.5 mg MDL 100,240 i.v. infusion. Second, in a three-group, parallel, randomised, double-blind study, each group of four subjects received q.d., over 8 days, 2.5, 10 or 20 mg of MDL 100,240 orally. The ACE inhibition profile was determined on day 1 and day 8. Trough plasma ACE was measured on days 2, 3 and 4. The recovery of ACE activity was monitored up to 72 h after the last dose of MDL 100,240. RESULTS: ACE inhibition profile was similar on day 1 and day 8, and trough inhibition remained unchanged after the 8 days of treatment with 10 mg or 20 mg. Following repeated 2.5-mg ingestion, trough inhibition increased from 33% to 44% after the eighth dose. The oral bioavailability of MDL 100,240 was estimated at 85%, not statistically different from 100%. The accumulation ratio at steady state was estimated at 112%. Expressing the accumulation ratio in terms of half-life, a t(1/2) of 0.31 days or 7. 5 h was estimated. CONCLUSION: MDL 100,240 (oral solution) has a good bioavailability, as estimated by ACE inhibition, and no drug accumulation seems to occur over 8 days with the 10-mg and 20-mg doses, but a slight rise in the trough level is observed with the 2. 5-mg dose.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The genomic loci occupied by RNA polymerase (RNAP) III have been characterized in human culture cells by genome-wide chromatin immunoprecipitations, followed by deep sequencing (ChIP-seq). These studies have shown that only ∼40% of the annotated 622 human tRNA genes and pseudogenes are occupied by RNAP-III, and that these genes are often in open chromatin regions rich in active RNAP-II transcription units. We have used ChIP-seq to characterize RNAP-III-occupied loci in a differentiated tissue, the mouse liver. Our studies define the mouse liver RNAP-III-occupied loci including a conserved mammalian interspersed repeat (MIR) as a potential regulator of an RNAP-III subunit-encoding gene. They reveal that synteny relationships can be established between a number of human and mouse RNAP-III genes, and that the expression levels of these genes are significantly linked. They establish that variations within the A and B promoter boxes, as well as the strength of the terminator sequence, can strongly affect RNAP-III occupancy of tRNA genes. They reveal correlations with various genomic features that explain the observed variation of 81% of tRNA scores. In mouse liver, loci represented in the NCBI37/mm9 genome assembly that are clearly occupied by RNAP-III comprise 50 Rn5s (5S RNA) genes, 14 known non-tRNA RNAP-III genes, nine Rn4.5s (4.5S RNA) genes, and 29 SINEs. Moreover, out of the 433 annotated tRNA genes, half are occupied by RNAP-III. Transfer RNA gene expression levels reflect both an underlying genomic organization conserved in dividing human culture cells and resting mouse liver cells, and the particular promoter and terminator strengths of individual genes.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

During the first hours after release of petroleum at sea, crude oil hydrocarbons partition rapidly into air and water. However, limited information is available about very early evaporation and dissolution processes. We report on the composition of the oil slick during the first day after a permitted, unrestrained 4.3 m(3) oil release conducted on the North Sea. Rapid mass transfers of volatile and soluble hydrocarbons were observed, with >50% of ≤C17 hydrocarbons disappearing within 25 h from this oil slick of <10 km(2) area and <10 μm thickness. For oil sheen, >50% losses of ≤C16 hydrocarbons were observed after 1 h. We developed a mass transfer model to describe the evolution of oil slick chemical composition and water column hydrocarbon concentrations. The model was parametrized based on environmental conditions and hydrocarbon partitioning properties estimated from comprehensive two-dimensional gas chromatography (GC×GC) retention data. The model correctly predicted the observed fractionation of petroleum hydrocarbons in the oil slick resulting from evaporation and dissolution. This is the first report on the broad-spectrum compositional changes in oil during the first day of a spill at the sea surface. Expected outcomes under other environmental conditions are discussed, as well as comparisons to other models.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In severe forms of Diamond-Blackfan anemia, preimplantation genetic diagnosis (PGD) of histocompatibility leukocyte antigen-compatible embryos for enabling the next sibling in the family to be a stem-cell transplantation donor constitutes the sole lasting cure capable of terminating the enduring need for iterative transfusions. We report here an open collaboration between two renowned institutions to provide a family desiring this treatment even though they resided where the preimplantation genetic diagnosis procedure is banned.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The central structure of the symbiotic association between plants and arbuscular mycorrhizal (AM) fungi is the fungal arbuscule that delivers minerals to the plant. Our earlier transcriptome analyses identified two half-size ABCG transporters that displayed enhanced mRNA levels in mycorrhizal roots. We now show specific transcript accumulation in arbusculated cells of both genes during symbiosis. Presently, arbuscule-relevant factors from monocotyledons have not been reported. Mutation of either of the Oryza sativa (rice) ABCG transporters blocked arbuscule growth of different AM fungi at a small and stunted stage, recapitulating the phenotype of Medicago truncatula stunted arbuscule 1 and 2 (str1 and str2) mutants that are deficient in homologous ABCG genes. This phenotypic resemblance and phylogenetic analysis suggest functional conservation of STR1 and STR2 across the angiosperms. Malnutrition of the fungus underlying limited arbuscular growth was excluded by the absence of complementation of the str1 phenotype by wild-type nurse plants. Furthermore, plant AM signaling was found to be intact, as arbuscule-induced marker transcript accumulation was not affected in str1 mutants. Strigolactones have previously been hypothesized to operate as intracellular hyphal branching signals and possible substrates of STR1 and STR2. However, full arbuscule development in the strigolactone biosynthesis mutants d10 and d17 suggested strigolactones to be unlikely substrates of STR1/STR2. Interestingly, rice STR1 is associated with a cis-natural antisense transcript (antiSTR1). Analogous to STR1 and STR2, at the root cortex level, the antiSTR1 transcript is specifically detected in arbusculated cells, suggesting unexpected modes of STR1 regulation in rice.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND: Sustained antibody levels are a hallmark of immunity against many pathogens, and induction of long-term durable antibody titers is an essential feature of effective vaccines. Heterologous prime-boost approaches with vectors are optimal strategies to improve a broad and prolonged immunogenicity of malaria vaccines. RESULTS: In this study, we demonstrate that the heterologous prime-boost regimen Ad35-CS/BCG-CS induces stronger immune responses by enhancing type 1 cellular producing-cells with high levels of CSp-specific IFN-γ and cytophilic IgG2a antibodies as compared to a homologous BCG-CS and a heterologous BCG-CS/CSp prime-boost regimen. Moreover, the heterologous prime-boost regimen elicits the highest level of LLPC-mediated immune responses. CONCLUSION: The increased IFN-γ-producing cell responses induced by the combination of Ad35-CS/BCG-CS and sustained type 1 antibody profile together with high levels of LLPCs may be essential for the development of long-term protective immunity against liver-stage parasites.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

"Thou shalt not bear false witness," as we all know. Yet changing one's mind in case of respectable reasons seems to be allowed. Which is good news for politicians, but reduces the effectiveness of prospective voting, i.e. the focus on "the commitments of candidates to take actions that citizens desire to be taken" (Powell 2000: 9). This may be bad news for voters. By comparing pre-election commitments of Swiss members of parliament (MPs) with actual voting behaviour in the lower house of parliament, the following article explores the question how much confidence voters can have in prospective voting and what factors explain (non-)fulfilment of election pledges.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This study assesses gender differences in spatial and non-spatial relational learning and memory in adult humans behaving freely in a real-world, open-field environment. In Experiment 1, we tested the use of proximal landmarks as conditional cues allowing subjects to predict the location of rewards hidden in one of two sets of three distinct locations. Subjects were tested in two different conditions: (1) when local visual cues marked the potentially-rewarded locations, and (2) when no local visual cues marked the potentially-rewarded locations. We found that only 17 of 20 adults (8 males, 9 females) used the proximal landmarks to predict the locations of the rewards. Although females exhibited higher exploratory behavior at the beginning of testing, males and females discriminated the potentially-rewarded locations similarly when local visual cues were present. Interestingly, when the spatial and local information conflicted in predicting the reward locations, males considered both spatial and local information, whereas females ignored the spatial information. However, in the absence of local visual cues females discriminated the potentially-rewarded locations as well as males. In Experiment 2, subjects (9 males, 9 females) were tested with three asymmetrically-arranged rewarded locations, which were marked by local cues on alternate trials. Again, females discriminated the rewarded locations as well as males in the presence or absence of local cues. In sum, although particular aspects of task performance might differ between genders, we found no evidence that women have poorer allocentric spatial relational learning and memory abilities than men in a real-world, open-field environment.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In the present study, we have investigated the anatomic distribution in blood and gut mucosal tissues of memory poxvirus-specific CD4 and CD8 T cells in subjects vaccinated with smallpox and compared it with vector (NYVAC)-specific and HIV insert-specific T-cell responses induced by an experimental DNA-C/ NYVAC-C vaccine regimen. Smallpox-specific CD4 T-cell responses were present in the blood of 52% of the subjects studied, while smallpox-specific CD8 T cells were rarely detected (12%). With one exception, smallpox-specific T cells were not measurable in gut tissues. Interestingly, NYVAC vector-specific and HIV-specific CD4 and CD8 T-cell responses were detected in almost 100% of the subjects immunized with DNA-C/NYVAC-C in blood and gut tissues. The large majority (83%) of NYVAC-specific CD4 T cells expressed α4β7 integrins and the HIV coreceptor CCR5. These results demonstrate that the experimental DNA-C/NYVAC-C HIV vaccine regimen induces the homing of potentially protective HIV-specific CD4 and CD8 T cells in the gut, the port of entry of HIV and one of the major sites for HIV spreading and the depletion of CD4 T cells.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

J Clin Hypertens (Greenwich). 2012;14:773-778. ©2012 Wiley Periodicals, Inc. Postmenopausal women are at greater risk for hypertension-related cardiovascular disease. Antihypertensive therapy may help alleviate arterial stiffness that represents a potential modifiable risk factor of hypertension. This randomized controlled study investigated the difference between an angiotensin receptor blocker and a calcium channel blocker in reducing arterial stiffness. Overall, 125 postmenopausal hypertensive women (age, 61.4±6 years; systolic blood pressure/diastolic blood pressure [SBP/DBP], 158±11/92±9 mm Hg) were randomized to valsartan 320 mg±hydrochlorothiazide (HCTZ) (n=63) or amlodipine 10 mg±HCTZ (n=62). The primary outcome was carotid-to-femoral pulse wave velocity (PWV) changes after 38 weeks of treatment. Both treatments lowered peripheral blood pressure (BP) (-22.9/-10.9 mm Hg for valsartan and -25.2/-11.7 mm Hg for amlodipine, P=not significant) and central BP (-15.7/-7.6 mm Hg for valsartan and -19.2/-10.3 mm Hg for amlodipine, P<.05 for central DBP). Both treatments similarly reduced the carotid-femoral PWV (-1.9 vs -1.7 m/s; P=not significant). Amlodipine was associated with a higher incidence of peripheral edema compared with the valsartan group (77% vs 14%, P<.001). BP lowering in postmenopausal women led to a reduction in arterial stiffness as assessed by PWV measurement. Both regimens reduced PWV to a similar degree after 38 weeks of treatment despite differences in central BP lowering, suggesting that the effect of valsartan on PWV is mediated through nonhemodynamic effects.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

OBJECTIVES: A straightforward original Chimney Graft (CG) protocol has been developed at our institution in selected cases of juxtarenal aortic aneurysm (JRAA). The aim of this study was to present our clinical experience of consecutive series with use of uncovered self-expanding stent (SES) as "Open Chimney" (OCh) in the endovascular repair (EVAR) of JRAA. METHODS: A standard endograft with suprarenal fixation struts is delivered with its proximal covered edge just below the highest RA in JRAA presenting the ostium of the two renal arteries at a different aortic level and the distance between the highest renal artery and the beginning of the aneurysm (improved landing zone) ≥10 mm. The low-lying renal artery is maintained patent by the OCh graft (standard SES) delivered from left brachial access (6 Fr). All clinical, anatomical, and operative data were prospectively collected and retrieved for the study analysis. RESULTS: From July 2010 to November 2012, OCh EVAR was offered to 22 consecutive patients considered unfit for JRAA open repair. All procedures were technically successful with aneurysm exclusion and patent OCh graft. One small perioperative type Ia endoleak spontaneously disappeared at the 3-month CT control. One patient died because of acute decompensated heart failure. One patient presented a left hemispheric stroke. The median follow-up of 18 months (range 7-35) showed aneurysm exclusion in all patients without type I and III endoleaks, SES stenosis, and/or renal impairment. CONCLUSIONS: OCh-EVAR is a straightforward technique that can be employed in selected cases of JRAA, avoiding the more complex and expensive fenestrated EVAR.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND: In a simulation based on a pharmacokinetic model we demonstrated that increasing the erythropoiesis stimulating agents (ESAs) half-life or shortening their administration interval decreases hemoglobin variability. The benefit of reducing the administration interval was however lessened by the variability induced by more frequent dosage adjustments. The purpose of this study was to analyze the reticulocyte and hemoglobin kinetics and variability under different ESAs and administration intervals in a collective of chronic hemodialysis patients. METHODS: The study was designed as an open-label, randomized, four-period cross-over investigation, including 30 patients under chronic hemodialysis at the regional hospital of Locarno (Switzerland) in February 2010 and lasting 2 years. Four subcutaneous treatment strategies (C.E.R.A. every 4 weeks Q4W and every 2 weeks Q2W, Darbepoetin alfa Q4W and Q2W) were compared with each other. The mean square successive difference of hemoglobin, reticulocyte count and ESAs dose was used to quantify variability. We distinguished a short- and a long-term variability based respectively on the weekly and monthly successive difference. RESULTS: No difference was found in the mean values of biological parameters (hemoglobin, reticulocytes, and ferritin) between the 4 strategies. ESAs type did not affect hemoglobin and reticulocyte variability, but C.E.R.A induced a more sustained reticulocytes response over time and increased the risk of hemoglobin overshooting (OR 2.7, p = 0.01). Shortening the administration interval lessened the amplitude of reticulocyte count fluctuations but resulted in more frequent ESAs dose adjustments and in amplified reticulocyte and hemoglobin variability. Q2W administration interval was however more favorable in terms of ESAs dose, allowing a 38% C.E.R.A. dose reduction, and no increase of Darbepoetin alfa. CONCLUSIONS: The reticulocyte dynamic was a more sensitive marker of time instability of the hemoglobin response under ESAs therapy. The ESAs administration interval had a greater impact on hemoglobin variability than the ESAs type. The more protracted reticulocyte response induced by C.E.R.A. could explain both, the observed higher risk of overshoot and the significant increase in efficacy when shortening its administration interval.Trial registrationClinicalTrials.gov NCT01666301.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Meropenem, a carbapenem antibiotic displaying a broad spectrum of antibacterial activity, is administered in Medical Intensive Care Unit to critically ill patients undergoing continuous veno-venous haemodiafiltration (CVVHDF). However, there are limited data available to substantial rational dosing decisions in this condition. In an attempt to refine our knowledge and propose a rationally designed dosage regimen, we have developed a HPLC method to determine meropenem after solid-phase extraction (SPE) of plasma and dialysate fluids obtained from patients under CVVHDF. The assay comprises the simultaneous measurement of meropenem's open-ring metabolite UK-1a, whose fate has never been studied in CVVHDF patients. The clean-up procedure involved a SPE on C18 cartridge. Matrix components were eliminated with phosphate buffer pH 7.4 followed by 15:85 MeOH-phosphate buffer pH 7.4. Meropenem and UK-1a were subsequently desorbed with MeOH. The eluates were evaporated under nitrogen at room temperature (RT) and reconstituted in phosphate buffer pH 7.4. Separation was performed at RT on a Nucleosil 100-5 microm C18 AB cartridge column (125 x 4 mm I.D.) equipped with a guard column (8 x 4 mm I.D.) with UV-DAD detection set at 208 nm. The mobile phase was 1 ml min(-1), using a step-wise gradient elution program: %MeOH/0.005 M tetrabutylammonium chloride pH 7.4; 10/90-50/50 in 27 min. Over the range of 5-100 microg ml(-1), the regression coefficient of the calibration curves (plasma and dialysate) were >0.998. The absolute extraction recoveries of meropenem and UK-1a in plasma and filtrate-dialysate were stable and ranged from 88-93 to 72-77% for meropenem, and from 95-104 to 75-82% for UK-1a. In plasma and filtrate-dialysate, respectively, the mean intra-assay precision was 4.1 and 2.6% for meropenem and 4.2 and 3.7% for UK-1a. The inter-assay variability was 2.8 and 3.6% for meropenem and 2.3 and 2.8% for UK-1a. The accuracy was satisfactory for both meropenem and UK-1a with deviation never exceeding 9.0% of the nominal concentrations. The stability of meropenem, studied in biological samples left at RT and at +4 degrees C, was satisfactory with < 5% degradation after 1.5 h in blood but reached 22% in filtrate-dialysate samples stored at RT for 8 h, precluding accurate measurements of meropenem excreted unchanged in the filtrate-dialysate left at RT during the CVVHDF procedure. The method reported here enables accurate measurements of meropenem in critically ill patients under CVVHDF, making dosage individualisation possible in such patients. The levels of the metabolite UK-1a encountered in this population of patients were higher than those observed in healthy volunteers but was similar to those observed in patients with renal impairment under hemodialysis.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Advanced neuroinformatics tools are required for methods of connectome mapping, analysis, and visualization. The inherent multi-modality of connectome datasets poses new challenges for data organization, integration, and sharing. We have designed and implemented the Connectome Viewer Toolkit - a set of free and extensible open source neuroimaging tools written in Python. The key components of the toolkit are as follows: (1) The Connectome File Format is an XML-based container format to standardize multi-modal data integration and structured metadata annotation. (2) The Connectome File Format Library enables management and sharing of connectome files. (3) The Connectome Viewer is an integrated research and development environment for visualization and analysis of multi-modal connectome data. The Connectome Viewer's plugin architecture supports extensions with network analysis packages and an interactive scripting shell, to enable easy development and community contributions. Integration with tools from the scientific Python community allows the leveraging of numerous existing libraries for powerful connectome data mining, exploration, and comparison. We demonstrate the applicability of the Connectome Viewer Toolkit using Diffusion MRI datasets processed by the Connectome Mapper. The Connectome Viewer Toolkit is available from http://www.cmtk.org/