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Delphine Jouin,Nadège Blanchard,Eliane Alexandre,Frédéric Delobel,Pascale David-Pierson,Thierry Lavé,Daniel Jaeck,Lysiane Richert,Philippe Coassolo Hepatocyte assays, routinely used to assess the metabolic stability of new chemical entities, were recently improved by using hepatocytes in suspension instead of primary cultures [N. Blanchard, L. Richert, B. Notter, F. Delobel, P. David, P. Coassolo, T. Lavé, Impact of serum on clearance predicti... ( view more )ons obtained from suspensions and primary cultures of rat hepatocytes, Eur. J. Pharm. Sci. 23 (2004) 189-199]. The aim of the present study was to investigate miniaturising the suspension assay by using cryopreserved human hepatocytes, i.e., 150,000 cells/well in 96-well plates, to predict hepatic clearance (CLH) in order to increase compound throughput and decrease cost and tissue requirements. For this, an evaluation was first carried out with rat hepatocytes. Then, human hepatocytes from various donors were used under these predetermined conditions, either immediately after isolation, either after a 20-h-cold storage period in UW or after cryopreservation. The values of CLint and CLH determined using human hepatocytes in suspension in 96-well plates, immediately after isolation, after cold storage or after cryopreservation, were comparable to those obtained with hepatocytes in primary culture. In particular, the use of cryopreserved human hepatocytes in suspension in a 96-well format appeared to be largely satisfactory as a tool for screening and ranking of compounds in the early phase of the drug discovery process. ( view less ) L Beguinot,D Werth,S Ito,N Richert,M C Willingham,I Pastan An antibody against the human epidermal growth factor receptor (EGF), capable of activating its tyrosine kinase has been produced. Antibody 2913 recognizes only the cytoplasmic portion of the EGF receptor in A431 carcinoma cells, in normal human fibroblasts, and in a variety of other human tumor ce... ( view more )ll lines (Xu, Y.-A., Richert, N., Ito, S., Merlino, G. T., and Pastan, I. (1984) Proc. Natl. Acad. Sci. U. S. A. 81, 7308-7313). Indirect immunofluorescence and electron microscopy show that the antibody binds to intact cells only after membrane permeabilization. Moreover the antibody immunoprecipitates the v-erb-B gene product in avian myeloblastosis virus-infected cells but does not recognize the secreted form (105 kDa) of the A431 cell EGF receptor which lacks the cytoplasmic domain. Antibody 2913 activates the EGF receptor kinase in solubilized A431 membranes causing autophosphorylation on tyrosine residues only. Tryptic peptide maps suggest that antibody 2913 and EGF stimulate phosphorylation of the same amino acid residues. By electron microscopy, the cytoplasmic portion of the receptor was followed throughout its endocytotic pathway. The results show that the kinase domain is rapidly degraded in lysosomes with no accumulation in the cytoplasm or in the nucleus. ( view less ) S Ito,D K Werth,N D Richert,I Pastan Vinculin phosphorylation by pp60src is stimulated by anionic phospholipids (Ito, S., Richert, N., and Pastan, I. (1982) Proc. Natl. Acad. Sci. U. S. A. 79, 4628-4631). We have examined whether vinculin interacts with phospholipids, the specificity of the interactions, and a possible mechanism for t... ( view more )he enhancement of vinculin phosphorylation by these phospholipids. 3H-labeled vinculin binds to phosphatidylserine, phosphatidylinositol, phosphatidylglycerol, and phosphatidic acid. No binding to phosphatidylcholine or phosphatidylethanolamine was observed. The phospholipid binding specificity correlated with the ability of these phospholipids to enhance vinculin phosphorylation by the src kinase. Chlorpromazine (0.1 and 0.3 mM) inhibited both vinculin binding to phosphatidylinositol and the enhanced phosphorylation of vinculin by pp60src in the presence of phosphatidylinositol. Tryptic peptide maps of vinculin phosphorylated in the absence of phospholipid revealed three phosphorylated peptides. The same three peptides were phosphorylated in the presence of phospholipid. However, phosphorylation at one site was markedly increased. In the presence of phospholipid proteolysis of vinculin with both chymotrypsin and V8 protease was markedly enhanced and different peptide maps of vinculin were generated. Microheterogeneity of vinculin was observed with isoelectric focusing. All the isoforms (pI 5.45-5.8) were found to bind phospholipids and undergo phosphorylation by the src kinase. These results suggest that one way anionic phospholipids can enhance vinculin phosphorylation is by binding to vinculin and inducing a conformational change in the vinculin molecule. ( view less ) P Fredman,N D Richert,J L Magnani,M C Willingham,I Pastan,V Ginsburg Monoclonal antibody 101 produced by a hybridoma obtained by fusion with NS-1 myeloma cells of spleen cells from a mouse immunized with the human epidermoid carcinoma cell line, A431, specifically precipitates epidermal growth factor receptor, a glycoprotein of 170,000 Mr solubilized from A431 cell ... ( view more )membranes (Richert, N. D., Willingham, M. C., and Pastan, I. H. (1983) J. Biol. Chem. 258, 8902-8907). The antibody also binds to neutral glycolipids extracted from A431 cells as evidenced by solid phase radioimmunoassay and by autoradiography. Binding of antibody to its target is inhibited by lacto-N-fucopentaose I but not by 2'-fucosyllactose or related oligosaccharides. Thus, antibody 101 is probably directed against the human blood group H type 1 sugar sequence Fuc alpha 1-2Gal beta 1-3GlcNAc . . .. This sequence presumably occurs on the epidermal growth factor receptor. Monoclonal antibody 102 produced by another hybridoma from the same fusion has the same cell specificity as antibody 101 and also binds to neutral glycolipids. However, binding of antibody 102 to its target is inhibited by 2'-fucosyllactose and not by lacto-N-fucopentaose I or related oligosaccharides. Thus, antibody 102 is probably directed against the human blood group H type 2 sugar sequence Fuc alpha 1-2Gal beta 1-4GlcNAc . . .. Antibody 102 does not precipitate solubilized epidermal growth factor receptor. Both antibodies bind to neutral glycolipids extracted from human erythrocytes belonging to blood group O but not to neutral glycolipids extracted from human erythrocytes with the "Bombay" phenotype. ( view less ) N D Richert,D L Blithe,I Pastan We recently described a method for the purification of a protein kinase related to pp60src from Rous sarcoma virus-induced rat tumors (Blithe, D. L., Richert, N. D., and Pastan, I. H. (1982) J. Biol. Chem. 257, 7135-7142). In this report, we describe some of the properties of the 7200-fold purified... ( view more ) enzyme. The purified kinase phosphorylates casein, vinculin, actin, and histone H2B, but not bovine serum albumin or ovalbumin. Protein substrates are phosphorylated exclusively on tyrosine residues. Casein was used as a substrate for more detailed analysis. The phosphorylation reaction proceeds at a linear rate for at least 40 min at 22 degrees C. Maximum enzyme activity occurs at pH 6.5 to pH 6.8 and requires the presence of either Mg2+ (5 to 10 mM) or Mn2+ (1 to 5 mM). The Km for ATP is 30 microM and the Vmax 0.03 mumol/min/mg using 0.4 mg/ml of casein as a substrate. The enzyme utilizes ATP or dATP, but not GTP as a phosphate donor in the reaction. The enzyme is inhibited by adenosine and deoxyadenosine and by their corresponding mono- and diphosphates. No inhibition of enzyme activity is observed with adenine, GTP, UTP, TTP, or CTP. The enzyme is very sensitive to increased ionic strength. Addition of 0.1 M KCl, 0.1 M NaCl, 50 mM KPO4, or 50 mM NaPO4 inhibited casein phosphorylation by 90 to 95%. Analysis of the products of the phosphorylation reaction by thin layer chromatography revealed that the src kinase phosphorylates glycerol in addition to casein or the enzyme itself. ( view less ) F Hispard,A de Vaufleury,H Martin,S Devaux,R P Cosson,R Scheifler,L Richert,A Berthelot,P-M Badot In an experimental food chain, Wistar rats were fed cadmium (Cd) in an inorganic (CdCl(2)) or organic (mainly associated with metallothionein from Helix aspersa snail viscera) form. After 1 month of exposure to 100 microg inorganic Cd g(-1) in food, an induction of metallothionein was observed in a... ( view more )ll target tissues. In liver, glutathione peroxidase (GSH-Px) activity decreased and alanine aminotransferase (ALAT) activity increased, suggesting that Cd causes hepatotoxicity. However, lipid peroxidation as well as catalase and caspase 3 (a marker of apoptosis) activities were not modified. At a rather low exposure (2.5 microg Cd g(-1)), metallothionein level in the kidney was found to be the most sensitive biomarker of exposure for both Cd forms. In the small intestine of rats ingesting inorganic Cd, metallothionein expression was significantly higher than that observed for rats fed organic Cd. Present results allowed proposing a simple design to assess the effect of a chemical in a trophic transfer approach. ( view less ) David A de Berker,Bertrand Richert,Edith Duhard,Bianca Maria Piraccini,Josette André,Robert Baran BACKGROUND: Proximal nail fold inflammation can be caused by many diseases and has not previously been recognized as a result of posterior embedding of the nail. We describe a new pattern of ingrowth that we have termed retronychia ("retro"--Latin for backwards; "onychia"--Greek for nail). The term... ( view more ) describes a combination of proximal nail plate ingrowth into the proximal nail fold which is associated with multiple generations of nail plate misaligned beneath the proximal nail. OBJECTIVE: To describe a new pattern of nail ingrowth which causes a specific form of proximal nail fold paronychia. METHODS: Collective cases were reported to a European Nail Society expert group. RESULTS: Persistent proximal nail fold inflammation can result from an episode of trauma that disturbs longitudinal nail growth and results in reverse embedding of the nail plate. This can cause pain, inflammation, and granulation tissue formation, and is typically relieved by avulsion and antiinflammatory treatment. LIMITATIONS: We cannot demonstrate causality between the proposed precipitants and the clinical features. CONCLUSION: Retroncyhia represents proximal ingrowth of the nail that occurs when the nail embeds backwards into the proximal nail fold. Nail plate avulsion with supplementary medical management is curative. ( view less ) Maria C Walsh,Gillian E Gardiner,Orla M Hart,Peadar G Lawlor,Mairead Daly,Brendan Lynch,Brian T Richert,Scott Radcliffe,Linda Giblin,Colin Hill,Gerald F Fitzgerald,Catherine Stanton,Paul Ross Relative predominance of each of five probiotic strains was investigated in the ileum of weaned pigs, compared with that in feces, when administered in combination at c. 5 x 10(9) CFU day(-1) for 28 days. Probiotic was excreted at 10(6)-10(9) CFU g(-1) feces, while ileal survival ranged from 10(2) ... ( view more )to 10(6) CFU g(-1) digesta. In contrast to the feces, where Lactobacillus murinus DPC6002 predominated, the bacteriocin-producing Lactobacillus salivarus DPC6005 dominated over coadministered strains both in the ileum digesta and in mucosa. Probiotic administration did not alter counts of culturable fecal Lactobacillus or Enterobacteriaceae but higher ileal Enterobacteriaceae were observed in the ileal digesta of probiotic-fed pigs (P<0.05). We observed decreased CD25 induction on T cells and monocytes (P<0.01) and decreased CTLA-4 induction (P<0.05) by the mitogen phytohemagglutinin on CD4 T cells from the probiotic group. Probiotic treatment also increased the proportion of CD4+ CD8+ T cells within the peripheral T-cell population and increased ileal IL-8 mRNA expression (P<0.05). In conclusion, superior ileal survival of L. salivarius compared with the other coadministered probiotics may be due to a competitive advantage conferred by its bacteriocin. The findings also suggest that the five-strain combination may function as a probiotic, at least in part, via immunomodulation. ( view less ) Malcolm Mounger Sawers Roland,Alp Sinan Baran,Allen Carl RichertGastroesophageal reflux is a suspected cause of sleep-related laryngospasm [Thurnheer R, Henz A, Knoblauch A. Sleep-related laryngospasm. Eur Respir J 1997;10:2084-6], but the relationship has not been directly documented by polysomnography (PSG). We report the case of an eight-year-old girl with a... ( view more )sthma who was referred for evaluation of awakenings with respiratory distress. The description of her events included stridorous breathing suggestive of laryngospasm. A PSG was performed with esophageal pH monitoring, and during the recording pH dropped below four on nine occasions. Following two of the pH drops, acute respiratory distress with stridor was documented in video and audio recording, supporting a causal relationship between sleep-related gastroesophageal reflux and laryngospasm. ( view less ) Fabio Variola,Ji-Hyun Yi,Ludovic Richert,James D Wuest,Federico Rosei,Antonio Nanci Many efforts have been made to promote cell activity at the surface of implants, mainly by modifying their topography and physicochemical properties. Here we demonstrate the feasibility of creating Ti6Al4V surfaces having both a microtexture and a nanotexture, and show that their properties can be ... ( view more )tailored by controlling the length of exposure to a mixture of H2SO4 and H2O2. Scanning electron microscopy (SEM), combined with energy-dispersive X-ray spectroscopy (EDX), indicated that beta-phase grains, which surround larger alpha-phase grains, are etched more rapidly, resulting in a surface composed of microscale cavities with alpha-grain boundaries. Furthermore, high-resolution SEM and atomic force microscopy (AFM) revealed the presence on the surfaces of both alpha- and beta-phase grains of a network of nanopits with mean diameters ranging between 13 and 21 nm. The grain surface roughness increases from about 4 nm on untreated samples to about 12 nm after 4h of treatment. AFM analysis showed that the depth of microscale cavities can be varied in the 10-180 nm range by controlling the extent of chemical etching. Fourier transform infrared spectroscopy (FT-IR), combined with ellipsometry, established that the etching generated an oxide layer with a thickness in the range 15-45 nm. The resulting new surfaces selectively promote the growth of osteoblasts while inhibiting that of fibroblasts, making them promising tools for regulating the activities of cells in biological environments. ( view less ) Delphine Icard-Arcizet,Olivier Cardoso,Alain Richert,Sylvie Hénon We designed a micromanipulation device that allows the local application of a constant force on living cells, and the measurement of their stiffness. The force is applied through an Arg-Gly-Asp-coated bead adhering on the cell and trapped in optical tweezers controlled by a feedback loop. Epifluore... ( view more )scence observations of green fluorescent protein-actin in the cells are made during force application. We observe a stiffening of cells submitted to a constant force within a few minutes, coupled to actin recruitment both at the bead-cell contact and up to several micrometers from the stress application zone. Moreover, kinetics of stiffening and actin recruitment exhibit a strong correlation. This work presents the first quantification of the dynamics of cell mechanical reinforcement under stress, which is a novel insight into the elucidation of the more general phenomenon of cell adaptation to stress. ( view less ) Lysiane Richert,Gregor Tuschl,Catherine Viollon-Abadie,Nadège Blanchard,Alexandre Bonet,Bruno Heyd,Nermin Halkic,Elmar Wimmer,Hugues Dolgos,Stefan O Mueller Induction of drug-metabolizing enzymes (DMEs) is highly species-specific and can lead to drug-drug interaction and toxicities. In this series of studies we tested the species specificity of the antidiabetic drug development candidate and mixed peroxisome proliferator-activated receptor (PPAR) alpha... ( view more )/gamma agonist (S)-4-O-tolylsulfanyl-2-(4-trifluormethyl-phenoxy)-butyric acid (EMD 392949, EMD) with regard to the induction of gene expression and activities of DMEs, their regulators, and typical PPAR target genes. EMD clearly induced PPARalpha target genes in rats in vivo and in rat hepatocytes but lacked significant induction of DMEs, except for cytochrome P450 (P450) 4A. CYP2C and CYP3A were consistently induced in livers of EMD-treated monkeys. Interestingly, classic rodent peroxisomal proliferation markers were induced in monkeys after 17 weeks but not after a 4-week treatment, a fact also observed in human hepatocytes after 72 h but not 24 h of EMD treatment. In human hepatocyte cultures, EMD showed similar gene expression profiles and induction of P450 activities as in monkeys, indicating that the monkey is predictive for human P450 induction by EMD. In addition, EMD induced a similar gene expression pattern as the PPARalpha agonist fenofibrate in primary rat and human hepatocyte cultures. In conclusion, these data showed an excellent correlation of in vivo data on DME gene expression and activity levels with results generated in hepatocyte monolayer cultures, enabling a solid estimation of human P450 induction. This study also clearly highlighted major differences between primates and rodents in the regulation of major inducible P450s, with evidence of CYP3A and CYP2C inducibility by PPARalpha agonists in monkeys and humans. ( view less ) F Hispard,A de Vaufleury,R P Cosson,S Devaux,R Scheifler,M Coeurdassier,F Gimbert,H Martin,L Richert,A Berthelot,P-M Badot Transfer and toxic effects of two cadmium (Cd) forms, inorganic (CdCl2 dosed rat food) or organic (contaminated snail-based rat food) were studied in Wistar rat. Cd concentrations in rat food were 0 and 2.5 microg Cd g(-1) for both inorganic and organic forms and a high concentration of 100 microg ... ( view more )Cd g(-1) was also tested for the inorganic form. Rats were exposed for four weeks to contaminated food. Both forms of Cd were bioavailable to rats, with a percentage of transfer from food to rats of around 1% for all contaminated groups. Cd concentrations in rat tissues increased with increasing Cd concentrations in the food. Rats fed with organic form of Cd accumulated significantly more Cd in the main organ for Cd toxicity, the kidney, than those eating the inorganic form. Survival was not affected for any rat group but a decrease in growth and food consumption was observed for the inorganic form. As a defence system against Cd toxicity, rats increased their metallothionein (MT) synthesis at the highest Cd concentration in the target organs (kidney, liver and small intestine) and even did the same at low Cd concentrations (2.5 microg Cd g(-1)) in the kidney. At this low Cd concentration, MT induction was lower in the small intestine of rats ingesting organic Cd than those ingesting inorganic Cd. Bioavailability of organic and inorganic forms of Cd was similar, but subsequent Cd distribution within organs was different. This quantification of the trophic transfer of both inorganic and organic forms of a toxicant is a basis for a better assessment of the fate and effects of chemicals in food webs. ( view less ) Karsten Siegmund,Carolin Ahlborn,Clemens Richert Incomplete binding, saturation, and cross-hybridization between partially complementary strands complicate the parallel detection of nucleic acids via DNA microarrays. Treating the competing equilibria governing binding to microarrays requires computational tools. We have developed the web-based pr... ( view more )ogram ChipCheckII that calculates total hybridization matrices for target strands interacting with probes on small DNA microarrays. The program can be used to compute the extent of cross-hybridization and other phenomena affecting fidelity of detection based on sequences, quantities of strands, and hybridization conditions as inputs. Enthalpy and entropy of duplex formation are generated locally with UNAfold, including those for complexes that are partially matched. Simulated binding versus temperature curves for portions of a commercial genome chip demonstrate the extent to which cross-hybridization can complicate DNA detection. ChipCheckII is expected to aid nucleic acid chemists in developing high fidelity DNA microarrays. ( view less ) Andrea Mandanici,Wei Huang,Maria Cutroni,Ranko Richert The dynamics of ethylcyclohexane are investigated by high resolution dielectric spectroscopy aiming to characterize the relevant relaxational features of this simple system in its fluid, supercooled liquid, and glassy states. The dielectric signature of structural relaxation is a primary loss peak ... ( view more )with amplitude Deltaepsilon=0.01, and a secondary loss process is found in the glassy state. This beta relaxation is compared with a "slow" process revealed by ultrasonics and with previously found gamma and chi processes in similar materials containing the cyclohexyl group. The results suggest that this secondary process is an intramolecular mode rather than a Johari-Goldstein process, consistent with its persistence in the liquid state at slow relaxation times which exceed those of the alpha process. The dielectric activity of such a slow process requires that the dipole magnitude changes with the intramolecular transition, whereas a change in dipole direction only would be masked by the faster structural relaxation. ( view less ) C H Polman,S C Reingold,F Barkhof,P A Calabresi,M Clanet,J A Cohen,G R Cutter,M S Freedman,L Kappos,F D Lublin,H F McFarland,L M Metz,A E Miller,X Montalban,P W O'Connor,H Panitch,J R Richert,J Petkau,S R Schwid,M P Sormani,A J Thompson,B G Weinshenker,J S Wolinsky The increasing number of established effective therapies for relapsing multiple sclerosis (MS) and emerging consensus for early treatment raise practical concerns and ethical dilemmas for placebo-controlled clinical trials in this disease. An international group of clinicians, ethicists, statistici... ( view more )ans, regulators, and representatives from the pharmaceutical industry convened to reconsider prior recommendations regarding the ethics of placebo-controlled trials in MS. The group concluded that placebo-controlled trials can still be done ethically, with restrictions. For patients with relapsing MS for which established effective therapies exist, placebo-controlled trials should only be offered with rigorous informed consent if the subjects refuse to use these treatments, have not responded to them, or if these treatments are not available to them for other reasons (e.g., economics). Suggestions are provided to protect subject autonomy and improve informed consent procedures. Recommendations are tighter than previously suggested for placebo-controlled trials in "resource-restricted" environments where established therapies may not be available. Guidance is also provided on the ethics of alternative trial designs and the balance between study subject burden and risk, scientific rationale and interpretability of trial outcomes. ( view less ) Florian Eberle,Kerstin Giessler,Christopher Deck,Klaus Heeg,Mirjam Peter,Clemens Richert,Alexander H Dalpke Synthetic small interfering RNA (siRNA) can suppress the expression of endogenous mRNA through RNA interference. It has been reported that siRNA can induce type I IFN production from plasmacytoid dendritic cells, leading to off-target effects. To separate immunostimulation from the desired gene-spe... ( view more )cific inhibitory activity, we designed RNA strands with chemical modifications at strategic positions of the ribose or nucleobase residues. Substitution of uridine residues by 2'-deoxyuridine or thymidine residues was found to decrease type I IFN production upon in vitro stimulation of human PBMC. Thymidine residues in both strands of a siRNA duplex further decreased immunostimulation. Fortunately, the thymidine residues did not affect gene-silencing activity. In contrast, 2'-O-methyl groups at adenosine and uridine residues reduced both IFN-alpha secretion and gene-silencing activity. Oligoribonucleotides with 2'-O-methyladenosine residues actively inhibited IFN-alpha secretion induced by other immunostimulatory RNAs, an effect not observed for strands with 2'-deoxynucleosides. Furthermore, neither 5-methylcytidine nor 7-deazaguanosine residues in the stimulatory strands affected IFN-alpha secretion, suggesting that recognition does not involve sites in the major groove of duplex regions. The activity data, together with structure prediction and exploratory UV-melting analyses, suggest that immunostimulatory sequences adopt folded structures. The results show that immunostimulation can be suppressed by suitable chemical modifications without losing siRNA potency by introducing seemingly minor structural changes. ( view less ) Josef Jäckle,Ranko RichertFor a linear medium, it is shown that the ratio of average relaxation to retardation time is given by the ratio of the high- to the low-frequency limit of the dielectric constants, tau(M)/tau(epsilon)=epsilon_{infinity}/epsilon(s) . This statement holds for dispersive dynamics, i.e., it is not limi... ( view more )ted to the special case of exponential responses. A second general relation is found for the relative relaxation-time dispersions, which implies that the relaxation is always more stretched than its retardation counterpart. A difference equation for the charge buildup is established which provides a rationale for why retardation requires more time than its relaxation counterpart. According to the equation, the slowness of the charge buildup is due to a renewal process of continuous re-investment of potential made redundant by relaxation. The relevance of the results to experimental situations is also discussed. ( view less ) Li-Min Wang,Yongjun Tian,Riping Liu,Ranko Richert An extensive comparison of calorimetric and dielectric measurements is carried out for generic molecular liquids and monohydroxy alcohols with focus on the identification of the dielectric modes which are associated with the glass transition. For generic liquids, the calorimetric glass transition t... ( view more )emperatures (T g-cal) are always greater than their kinetic counterparts (T g-kin), but the difference remains below 3 K. Also, the nonexponentiality parameters of the Tool-Narayanaswamy-Moynihan-Hodge model applied to the calorimetric data and the stretching exponents of the dielectric measurements show remarkable agreement. The same behavior is found for glass-forming monohydroxy alcohols, provided that the faster and smaller non-Debye relaxation rather than the large dielectric Debye process is assigned to the structural relaxation. The study emphasizes that the dielectric signature of the glass transition in monohydroxy alcohols is a dispersive loss peak that is faster and significantly smaller than the prominent Debye feature. ( view less ) Helga Richert Munch-Petersen,Jacob RosenbergMinimally invasive surgery (MIS) is in theory more physically and mentally demanding than open surgery. This aspect is due to the inherent limits of MIS. The implementation of high-technological operating rooms and the development of ergonomically more useful instruments have not been documented sc... ( view more )ientifically, nor has the question of whether or not MIS is a contributing problem in itself in the surgeon's work been documented. There is a need for clinical investigations with establishment of methodological models of the ergonomics in MIS. ( view less ) D Pekthong,H Martin,C Abadie,A Bonet,B Heyd,G Mantion,L Richert The inhibitory effect of Andrographis paniculata extract (APE) and andrographolide (AND), the most medicinally active phytochemical in the extract, on hepatic cytochrome P450s (CYPs) activities was examined using rat and human liver microsomes. For this purpose, CYP1A2-dependent ethoxyresorufin-O-d... ( view more )eethylation, CYP2B1-dependent benzyloxyresorufin-O-dealkylation, CYP2B6-dependent bupropion hydroxylation, CYP2C-dependent tolbutamide hydroxylation, CYP2E1-dependent p-nitrophenol hydroxylation and CYP3A-dependent testosterone 6 beta-hydroxylation activities, were determined in the presence and absence of APE or AND (0-200 microM). APE inhibited ethoxyresorufin-O-deethylation activity in rat and human liver microsomes, with apparent Ki values of 8.85 and 24.46 microM, respectively. In each case, the mode of inhibition was noncompetitive. APE also inhibited tolbutamide hydroxylation both in rat and human microsomes with apparent Ki values of 8.21 and 7.51 microM, respectively and the mode of inhibition was mixed type. In addition, APE showed a competitive inhibition only on CYP3A4 in human microsomes with Ki of 25.43 microM. AND was found to be a weak inhibitor of rat CYP2E1 with a Ki of 61.1 microM but did not affect human CYP2E1. In conclusion, it cannot be excluded from the present study that APE could cause drug-drug interactions in humans through CYP3A and 2C9 inhibition. ( view less ) Laura Richert,Brigitte Uebelhart,Marc Engelhardt,Moise Azria,René Rizzoli ABSTRACT: BACKGROUND: Bone microarchitecture is a significant determinant of bone strength. So far, the assessment of bone microarchitecture has required bone biopsies, limiting its utilization in clinical practice to one single skeletal site. With the advance of high-resolution imaging techniques,... ( view more ) non-invasive in vivo measurement of bone microarchitecture has recently become possible. This provides an opportunity to efficiently assess the effects of anti-osteoporotic therapies on bone microarchitecture. We therefore designed a protocol to investigate the effects of nasal salmon calcitonin, an inhibitor of osteoclast activity, on bone microarchitecture in postmenopausal women, comparing weight bearing and non-weight bearing skeletal sites. METHODS: One hundred postmenopausal women will be included in a randomized, placebo-controlled, double-blind trial comparing the effect of nasal salmon calcitonin (200 UI/day) to placebo over two years. Bone microarchitecture at the distal radius and distal tibia will be determined yearly by high-resolution peripheral quantitative computerized tomography (p-QCT) with a voxel size of 82 mum and an irradiation of less than 5 muSv. Serum markers of bone resorption and bone formation will be measured every 6 months. Safety and compliance will be assessed. Primary endpoint is the change in bone microarchitecture; secondary endpoint is the change in markers of bone turnover. HYPOTHESIS: The present study should provide new information on the mode of action of nasal calcitonin. We hypothezise that - compared to placebo - calcitonin impacts on microstructural parameters, with a possible difference between weight bearing and non-weight bearing bones. TRIAL REGISTRATION: ClinicalTrials.gov NCT00372099. ( view less ) Harriet Watkin,Monica M Richert,Andrew Lewis,Kristina Terrell,James P McManaman,Steven M Anderson BACKGROUND: Mammary gland development culminates in lactation and is orchestrated by numerous stimuli and signaling pathways. The Src family of nonreceptor tyrosine kinases plays a pivotal role in cell signaling. In order to determine if Src plays a role in mammary gland development we have examine... ( view more )d mammary gland development and function during pregnancy and lactation in mice in which expression of Src has been eliminated. RESULTS: We have characterized a lactation defect in the Src-/- mice which results in the death of over 80% of the litters nursed by Src-/- dams. Mammary gland development during pregnancy appears normal in these mice; however secretory activation does not seem to occur. Serum prolactin levels are normal in Src-/- mice compared to wildtype controls. Expression of the prolactin receptor at both the RNA and protein level was decreased in Src-/- mice following the transition from pregnancy to lactation, as was phosphorylation of STAT5 and expression of milk protein genes. These results suggest that secretory activation, which occurs following parturition, does not occur completely in Src-/- mice. Failed secretory activation results in precocious involution in the mammary glands of Src-/- even when pups were suckling. Involution was accelerated following pup withdrawal perhaps as a result of incomplete secretory activation. In vitro differentiation of mammary epithelial cells from Src-/- mice resulted in diminished production of milk proteins compared to the amount of milk proteins produced by Src+/+ cells, indicating a direct role for Src in regulating the transcription/translation of milk protein genes in mammary epithelial cells. CONCLUSION: Src is an essential signaling modulator in mammary gland development as Src-/- mice exhibit a block in secretory activation that results in lactation failure and precocious involution. Src appears to be required for increased expression of the prolactin receptor and successful downstream signaling, and alveolar cell organization. ( view less ) Carolin Ahlborn,Karsten Siegmund,Clemens Richert The high fidelity detection of multiple DNA sequences in multiplex assays calls for duplexes whose stability is independent of sequence (isostable DNA), forming under universally stringent conditions. Nature did not evolve DNA to form isostable duplexes. Here we report how probe strands can be modi... ( view more )fied so that an all-A/T target strand is bound with the same or slightly higher affinity than the corresponding all-G/C strand with the same sequence of purines and pyrimidines. We refer to these probes that feature covalently attached ligands as "decorated nucleic acids". Caps, intercalators, and locks were used to stabilize A/T duplexes, and N4-ethylcytosine residues were employed to tune down the stability of G/C duplexes without significantly affecting base pairing selectivity. Near-isostability was demonstrated in solution and on microarrays of high and low density. Further, it is shown that hybridization results involving decorated probes on microarrays can be predicted on the basis of thermodynamic data for duplex formation in solution. Predictable formation of isostable DNA not only benefits microarrays for gene expression analysis and genotyping, but may also improve the sequence-specificity of other applications that rely on the massively parallel formation of Watson-Crick duplexes. ( view less ) Hélène Martin,Frank Staedtler,Christelle Lamboley,Markus Adrian,Martin M Schumacher,Salah-Dine Chibout,Pascal Laurant,Lysiane Richert,Alain Berthelot In the present study we investigated the effect of a two-year treatment period with a diet containing 3.2g, 0.8 g and 0.15 g Mg/kg, on the rat liver transcriptome. At the end of the study, a treatment-dependent decrease in plasmatic Mg concentration was found (0.86 +/- 0.02 mmol/L, 0.70 +/- 0.02 mm... ( view more )ol/L and 0.52 +/- 0.03 mmol/L for groups receiving 3.2g, 0.8 g and 0.15 g Mg/kg diet, respectively). No significant treatment-related effect on body and liver weights was observed, however a dietary Mg intake-dependent increase in mortality rate occurred in animals (11%, 25% and 38% death of animals). Mg content in the diet affected gene expression in rat livers, as assessed by rat specific DNA microarrays. We identified 11 genes up-regulated and 39 genes down-regulated by at least two-fold by a decrease in Mg content and grouped them within five functional pathways: metabolism 20%, cytoarchitecture (connective tissue/cell adhesion/cytoskeleton) 12%, channels/ transporters 20%, turn-over (nucleic acid and protein) 16%, and homeostasis (stress/DNA damage/apoptosis/ageing) 32%. The results of the present study confirm the pleiotropic effects of Mg and provide further evidence that a Mg decrease in the diet may be considered as a promoting factor for pathologies, especially in the liver, during ageing. ( view less )
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