First wheat certified reference material for organically bound tritium measurement in the environment.

Measuring the radioactivity of organically bound tritium in environmental samples is difficult. For the past twenty years, many laboratories have been working on the development of reliable tritium measurement methods. In this context, several interlaboratory comparisons have been organised to develop these methods and enable laboratories to compare themselves.

Controlled Potential Coulometry for the accurate determination of plutonium in the presence of uranium: The role of sulfate complexation.

Controlled Potential Coulometry (CPC) is generally regarded as one of the most accurate analytical methods available for the quantification of plutonium (Pu) in acidic aqueous solutions. With a growing use of mixed oxide nuclear fuel, there has been an interest in the technique's applicability to the analysis of Pu in the presence of uranium (U). Expanding on previous studies, the work presented herein demonstrates the highly accurate CPC analysis of Pu in mixed solutions (Pu + U) containing large quantities of U (U:Pu up to 100:1) as well as establishing the role played by sulfate anions during the analyses.

Synthesis and in vitro evaluation of new 5-substituted 6-nitroimidazooxazoles as antikinetoplastid agents.

In continuation of our pharmacomodulation work on the nitroimidazooxazole series, we report the synthesis of new 5-substituted 6-nitroimidazooxazole derivatives. Our aim was to evaluate how functionalization of the 5-position of the 6-nitroimidazooxazole scaffold affects antileishmanial and antitrypanosomal in vitro activities. Twenty-one original compounds were synthesized and evaluated for their in vitro antileishmanial (L.

2,4-Disubstituted 5-Nitroimidazoles Potent against Clostridium difficile.

Metronidazole is one of the first-line treatments for non-severe Clostridium difficile infections (CDI). However, resistance limits its use in cases of severe and complicated CDI. Structure-activity relationships previously described for the 5-nitroimidazole series have shown that functionalization at the 2- and 4-positions can impart better activity against parasites and anaerobic bacteria than metronidazole.

8-Aryl-6-chloro-3-nitro-2-(phenylsulfonylmethyl)imidazo[1,2-a]pyridines as potent antitrypanosomatid molecules bioactivated by type 1 nitroreductases.

Based on a previously identified antileishmanial 6,8-dibromo-3-nitroimidazo[1,2-a]pyridine derivative, a Suzuki-Miyaura coupling reaction at position 8 of the scaffold was studied and optimized from a 8-bromo-6-chloro-3-nitroimidazo[1,2-a]pyridine substrate. Twenty-one original derivatives were prepared, screened in vitro for activity against L. infantum axenic amastigotes and T.

An Efficient One-Pot Catalyzed Synthesis of 2,4-Disubstituted 5-Nitroimidazoles Displaying Antiparasitic and Antibacterial Activities.

A one-pot regioselective bis-Suzuki-Miyaura or Suzuki-Miyaura/Sonogashira reaction on 2,4-dibromo-1-methyl-5-nitro-1-imidazole under microwave heating was developed. This method is applicable to a wide range of (hetero)arylboronic acids and terminal alkynes. Additionally, this approach provides a simple and efficient way to synthesize 2,4-disubstituted 5-nitroimidazole derivatives with antibacterial and antiparasitic properties.

Discovery of new thienopyrimidinone derivatives displaying antimalarial properties toward both erythrocytic and hepatic stages of Plasmodium.

A preliminary in vitro screening of compounds belonging to various chemical families from our library revealed the thieno[3,2-d]pyrimidin-4(3H)-one scaffold displayed a promising profile against Plasmodium falciparum. Then, 120 new derivatives were synthesized and evaluated in vitro; compared to drug references, 40 showed good activity toward chloroquine sensitive (IC50 35-344 nM) and resistant (IC50 45-800 nM) P. falciparum strains.

Targeting the human parasite Leishmania donovani: discovery of a new promising anti-infectious pharmacophore in 3-nitroimidazo[1,2-a]pyridine series.

We report herein the discovery of antileishmanial molecules based on the imidazo[1,2-a]pyridine ring. In vitro screenings of imidazopyridines belonging to our chemical library, toward the promastigotes stage of Leishmania donovani, J774A.1 murine and HepG2 human cells, permitted to identify three selective hit-compounds (12, 20 and 28).

Synthesis and promising in vitro antiproliferative activity of sulfones of a 5-nitrothiazole series.

 The synthesis in water of new sulfone derivatives under microwave irradiation is described. This eco-friendly process leads to the expected products in good yields by reaction of various substituted sulfinates (commercially available or obtained by reduction of the corresponding sulfonyl chlorides) with 4-chloromethyl-2-methyl-5-nitro-1,3-thiazole. In order to evaluate the antiproliferative effect of these compounds, several sulfone derivatives are also dichlorinated on the Cα next to the sulfonyl group.

[Targeted based therapies in metastatic breast cancer: future evolution].

Research on molecular alteration process mechanisms leading to cancerogenesis permitted the elaboration of many targeted therapies. Some therapeutic classes appeared recently and are currently being tested, including HER-2 dimerization inhibitors. However, most of these therapies are mostly ineffective with monotherapy.

Tandem synthesis and in vitro antiplasmodial evaluation of new naphtho[2,1-d]thiazole derivatives.

A series of naphtho[2,1-d]thiazoles was prepared in good yields under microwave irradiation with an original protocol combining tandem direct arylation and intramolecular Knoevenagel reaction on 1,3-thiazole derivatives. Antiplasmodial evaluation of this series highlighted two hit compounds (compounds 11 and 13) displaying promising in vitro activity on the multiresistant K1 Plasmodium falciparum strain. Structure-toxicity and structure-activity relationships are also discussed and reveal the importance of the R(1) and R(4) substituents of the naphthyl moiety for the biological profile of the series.

[News on infantile hemangioma therapy by beta-blocker].

Hemangiomas are benign tumors most commonly encountered in infancy and early childhood. While most of them regress spontaneously, some require treatment due to a significant proliferation, which may be complicated by ulceration, deformation aesthetic deformation or worse impairment vital. Among the treatments used corticosteroids is the standard treatment but its use in high doses expose to potential risks.

Development of metronidazole-resistant lines of Blastocystis sp.

Metronidazole (MTR) is frequently used for the treatment of Blastocystis infections, but with variable effectiveness, and often with treatment failures as a possible result of drug resistance. We have developed two Blastocystis MTR-resistant (MTR(R)) subtype 4 WR1 lines (WR1-M4 and WR1-M5), with variable susceptibility to a panel of anti-protozoal agents including various 5-nitroimidazoles, nitazoxanide and furazolidone. WR1-M4 and WR1-M5 were developed and assessed over an 18-month period and displayed persistent MTR resistance, being more than 2.

High functionalization of 5-nitro-1H-imidazole derivatives: the TDAE approach.

We report herein the synthesis of substituted 2-[4-(1,2-dimethyl-5-nitro-1H-imidazol-4-yl)phenyl]-1-arylethanols, ethyl 3-[4-(1,2-dimethyl-5-nitro-1H-imidazol-4-yl)-phenyl]-2-hydroxypropanoate and 2-[4-(1,2-dimethyl-5-nitro-1H-imidazol-4-yl)benzyl]-2-hydroxy-acenaphthylen-1(2H)-one from the reactions of 4-[4-(chloromethyl)phenyl]-1,2-dimethyl-5-nitro-1H-imidazole with various aromatic carbonyl and a-carbonyl ester derivatives using tetrakis(dimethylamino)ethylene (TDAE) methodology.

Risk of influenza-like illness in an acute health care setting during community influenza epidemics in 2004-2005, 2005-2006, and 2006-2007: a prospective study.

Background: The person-to-person transmission of influenza-like illness (ILI) and influenza has been described mostly in long-term care units. Studies in acute hospital settings are rare and mostly retrospective.

Methods: We prospectively estimated the relative risk (RR) of hospital-acquired (HA) ILI during hospitalization according to in-hospital exposures to contagious individuals.

Synthesis and evaluation of original amidoximes as antileishmanial agents.

An original series of amidoxime derivatives was synthesized using manganese(III) acetate, Buchwald-Hartwig and Heck reactions. Two amidoximes (39 and 52) showed interesting in vitro activities toward Leishmania donovani promastigotes, exhibiting 8.3 and 8.

A new-generation 5-nitroimidazole can induce highly metronidazole-resistant Giardia lamblia in vitro.

The 5-nitroimidazole (NI) compound C17, with a side chain carrying a remote phenyl group in the 2-position of the imidazole ring, is at least 14-fold more active against the gut protozoan parasite Giardialamblia than the 5-NI drug metronidazole (MTR), with a side chain in the 1-position of the imidazole ring, which is the primary drug for the treatment of giardiasis. Over 10 months, lines resistant to C17 were induced in vitro and were at least 12-fold more resistant to C17 than the parent strains. However, these lines had ID(90) values (concentration of drug at which 10% of control parasite ATP levels are detected) for MTR of >200 microM, whilst lines induced to be highly resistant to MTR in vitro have maximum ID(90) values around 100 microM (MTR-susceptible isolates typically have an ID(90) of 5-12.

Lowering of 5-nitroimidazole's mutagenicity: towards optimal antiparasitic pharmacophore.

To improve the antiparasitic pharmacophore, 20 5-nitroimidazoles bearing an arylsulfonylmethyl group were prepared from commercial imidazoles. The antiparasitic activity of these molecules was assessed against Trichomonas vaginalis, the in vitro cytotoxicity was evaluated on human monocytes and the mutagenicity was determined by the Salmonella mutagenicity assay. All IC(50) on T.

Synthesis of new potentially bioactive bicyclic 2-pyridones.

Three convenient methods of reduction of the nitro group of 5-nitroimidazoles and 5-nitrothiazole that bear a diethylmethylene malonate group in an ortho-like position with respect to the nitro group and cyclization of the resulting amino derivatives are reported. These reactions afforded the target bicyclic 2-pyridones in good to excellent yields.

2-[2-Methyl-5-nitro-4-(phenylsulfonylmethyl)imidazol-1-yl]ethanol and 2-methyl-5-nitro-4-phenylsulfonylmethyl-1,3-thiazole.

The title compounds, C(13)H(15)N(3)O(5)S and C(11)H(10)N(2)O(4)S(2), respectively, both contain a phenylsulfonyl group connected, through a methylene bridge, to either a substituted nitroimidazole or nitro-1,3-thiazole ring. In the imidazole-containing molecule, the nitro and sulfonyl groups are trans relative to the sulfonyl-methyl bond, while in the thiazole-containing molecule, these substituents are cis. The stabilizing interactions within the crystals are also different between the two compounds.

Synthesis and biological evaluation of O-alkylated tropolones and related alpha-ketohydroxy derivatives as ribonucleotide reductase inhibitors.

A series of O-alkylated tropolones and related alpha-ketohydroxy compounds were evaluated for their biological activities and were shown to present an expected ribonucleotide reductase inhibition and cytotoxicity against some cancer cell lines but no antitubulin activity. Pharmacomodulation studies were realised to understand and enhance the observed activities. These original benzylic, heterocyclic and allylic compounds have been synthesised by a phase-transfer catalysed O-alkylation developed in our laboratories.

Functional derivatives of 5-benzo[1, 3]dioxol-5-yl-1-methyl-1H-imidazole-2-carbaldehyde and evaluation of leishmanicidal activity.

New imidazole derivatives were obtained after subjecting 5-benzo[1, 3]dioxol-5-yl-1-methyl-1H-imidazole-2-carbaldehyde to a Knoevenagel reaction. Some of these compounds exhibit significant in vitro leishmanicidal activity.

Evaluation of the mutagenic and genotoxic activities of 48 nitroimidazoles and related imidazole derivatives by the Ames test and the SOS chromotest.

The mutagenic and genotoxic activities of 48 nitroimidazoles and related imidazole derivatives have been evaluated by using modified versions of the Ames test and the SOS Chromotest. Salmonella typhimurium tester strain TA 100 was used with and without metabolic activation in the Ames test and Escherichia coli tester Strain PQ 37 was used with and without metabolic activation in the SOS Chromotest. Including metronidazole and dimetridazole, 45 derivatives were mutagenic and genotoxic.