Detection of target DNA using fluorescent cationic polymer and peptide nucleic acid probes on solid support

BACKGROUND: Nucleic acids detection using microarrays requires labelling of target nucleic acids with fluorophores or other reporter molecules prior to hybridization. RESULTS: Using surface-bound peptide nucleic acids (PNA) probes and soluble fluorescent cationic polythiophenes, we show a simple and sensitive electrostatic approach to detect and identify unlabelled target nucleic acid on microarray. CONCLUSION: This simple methodology opens exciting possibilities for applied genetic analysis for the diagnosis of infections, identification of genetic mutations, and forensic inquiries. This electrostatic strategy could also be used with other nucleic acid detection methods such as electrochemistry, silver staining, metallization, quantum dots, or electrochemical dyes

Développement et caractérisation d'une puce à cellules pour le criblage d'agents toxiques

COMPIEGNE-BU (601592101) / SudocSudocFranceF

Evaluation of a liver microfluidic biochip to predict In vivo clearances of seven drugs in rats

We investigated metabolic clearances of phenacetin, midazolam, propranolol, paracetamol, tolbutamide, caffeine, and dextromethorphan by primary rat hepatocytes cultivated in microfluidic biochips. The levels of mRNA of the HNF4 alpha, PXR, AHR, CYP3A1, and CYP1A2 genes were enhanced in the biochip cultures when compared with postextraction levels. We measured a high and rapid adsorption on the biochip walls and inside the circuit for dextromethorphan and midazolam, a moderate adsorption for phenacetin and propranolol, and a low adsorption for caffeine, tolbutamide, and paracetamol. Drug biotransformations were demonstrated by the formations of specific metabolites such as paraxanthyne (caffeine), paracetamol (phenacetin), 1-OH midazolam (midazolam), paracetamol sulfate (paracetamol and phenacetin), and dextrorphan (dextromethorphan). We used a pharmacokinetic model to estimate the adsorption and in vitro intrinsic drug clearance values. We calculated in vitro intrinsic clearance values of 0.5, 3, 12.5, 83, 100, 160, and 900 mu L/min per 10(6) cells for the tolbutamide, caffeine, paracetamol, dextromethorphan, phenacetin, midazolam, and propranolol, respectively. A second model describing the liver as a well-stirred compartment predicted in vivo hepatic clearances of 0.1, 13.8, 30, 44.1, 61, 72, 85, and 61 mL/min per kg of body mass for the tolbutamide, caffeine, paracetamol, midazolam, dextromethorphan, phenacetin, and propranolol, respectively. These values appeared consistent with previously reported data

Sniff nasal inspiratory pressure in the longitudinal assessment of young Duchenne muscular dystrophy children

International audienceTraditional measures of respiratory function in children with Duchenne muscular dystrophy (DMD) are based on maximal inspiratory pressure (PImax) and vital capacity (VC). Sniff nasal inspiratory pressure (SNIP) measurements are easily performed by young children with neuromuscular disorders. The clinical value of SNIP in the longitudinal assessment of respiratory weakness remains to be assessed. The objective of the present study was to assess longitudinally the changes in SNIP, PImax and VC with age in DMD children. We hypothesised that their longitudinal assessment would show an earlier decline in SNIP than VC.A 3-year, prospective follow-up, at 6-month intervals of, 33 steroid-naïve, 5–20-year-old DMD patients was analysed using a linear mixed model.SNIP measurements were reliable (within-session coefficient of variation 8%). SNIP and VC increased until 10.5 and 12.5 years of age, respectively, and declined thereafter, while PImax did not change with age.SNIP was an earlier marker of decline in respiratory muscle strength (at 10.5 years) than VC (at 12.5 years) in young DMD patients. SNIP longitudinal assessment is useful in the detection of inspiratory strength decline in young DMD patients when VC values remain within normal values and as an outcome measure in clinical trials for emerging therapeutics in young DMD patients from the age of 5 years

Evaluation of seven drug metabolisms and clearances by cryopreserved human primary hepatocytes cultivated in microfluidic biochips

International audienceWe present characterization of the metabolic performance of human cryopreserved hepatocytes cultivated in a platform of parallelized microfluidic biochips. The RTqPCR analysis revealed that the mRNA levels of the cytochromes P450 (CYP 1A2, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, 3A4) were reduced after the adhesion period (when compared to the post-thawing step). The microfluidic perfusion played a part in stabilizing and partially recovering the levels of the HNF4a, PXR, OAPT2, CYP 1A2, 2B6, 2C19 and 3A4 mRNA on contrary to non-perfused cultures. Fluorescein diacetate staining and P-gp mRNA level illustrated the hepatocytes' polarity in the biochips. Drug metabolism was assessed using midazolam, tolbutamide, caffeine, omeprazole, dextromethorphan, acetaminophen and repaglinide as probes. Metabolite detection and quantification revealed that CYP1A2 (via the detection of paraxanthine), CYP3A4 (via 1-OH-midazolam, and omeprazole sulfone detection), CYP2C8 (via hydroxyl-repaglinide detection), CYP2C19 (via hydroxy-omeprazole detection) and CYP2D6 (via dextrorphan detection) were functional in our microfluidic configurations. Furthermore, the RTqPCR analysis showed that the drugs acted as inductors leading to overexpression of mRNA levels when compared to post-thawing values (such as for HNF4a, PXR and CYP3A4 by dextromethorpahn and omeprazole). Finally, intrinsic in vitro biochip clearances were extracted using a PBPK model for predictions. The biochip predictions were compared to literature in vitro data and in vivo situations

Complexes de lanthanides à base de dendrimères

The present invention relates to a complex comprising at least one dendrimer and at least one lanthanide, in which the dendrimer comprises a unit of formula (I), wherein: C1 is a group with a valency of 4 of formula >N-CH2-CH2-NN-CH2-CH2-N<; - A1, A2 et A3 sont des groupes de formule -(CH2)2-C(O)-NH-(CH2)2-; ledit motif de formule (I) étant relié de façon covalente à au moins une antenne qui absorbe à une longueur d'onde allant de 500 nm à 900 nm