C4-C5 fused pyrazol-3-amines: when the degree of unsaturation and electronic characteristics of the fused ring controls regioselectivity in Ullmann and acylation reactions

Pyrazol-3-amine is a scaffold present in a large number of compounds with a wide range of biological activities and, in many cases, the heterocycle is C4-C5 fused to a second ring. Among the different reactions used for the decoration of the pyrazole ring, Ullmann and acylation have been widely applied. However, there is some confusion in the literature regarding the regioselectivity of such reactions (substitution at N1 or N2 of the pyrazole ring) and no predictive rule has been so far established. As a part of our work on 3-amino-pyrazolo[3,4-b]pyridones 13, we have studied the regioselectivity of such reactions in different C4-C5 fused pyrazol-3-amines. As a rule of thumb, the Ullmann and acylation reactions take place, predominantly, at the NH and non-protonated nitrogen atom of the pyrazole ring respectively, of the most stable initial tautomer (1H- or 2H-pyrazole), which can be easily predicted by using DFT calculations

An Unequivocal Synthesis of 2-Aryl Substituted 3-Amino-2,4,5,7-tetrahydro-6H-pyrazolo[3,4-b]pyridin-6-ones

The reaction between pyridones (1) and substituted hydrazines 4 can afford two different regioisomeric pyrazolo[3,4-b]pyridin - 6-ones 2 and 3 depending on the initial substitution of the methoxy group and the direction of the cyclization. In the case of phenylhydrazine 4 (R3 = Ph), we have clearly shown that the treatment of pyridones 1a-d with 4 (R3 = Ph) in MeOH at temperatures below 1408C yields, independently of the nature and position of the substituents present in the pyridone ring, the open intermediates 7a-d. When the reaction is carried at 1408C under microwave irradiation, the corresponding 2-aryl substituted pyrazolo[3,4-b]pyridines 3a-d are always formed. We have experimentally determined, using DSC techniques, the activation energies of the two steps involved in the formation of 3: a) substitution of the methoxy group present in pyridones 1 with phenylhydrazine 4 (R3 = Ph) to afford intermediates 7 and b) cyclization of intermediates 7 to yield pyrazolopyridines 3. The results obtained, 15 and 42 kcal·mol 1 respectively, are in agreement with the experimental findings

A Genome-Wide Collection of Mos1 Transposon Insertion Mutants for the C. elegans Research Community

Methods that use homologous recombination to engineer the genome of C. elegans commonly use strains carrying specific insertions of the heterologous transposon Mos1. A large collection of known Mos1 insertion alleles would therefore be of general interest to the C. elegans research community. We describe here the optimization of a semi-automated methodology for the construction of a substantial collection of Mos1 insertion mutant strains. At peak production, more than 5,000 strains were generated per month. These strains were then subject to molecular analysis, and more than 13,300 Mos1 insertions characterized. In addition to targeting directly more than 4,700 genes, these alleles represent the potential starting point for the engineered deletion of essentially all C. elegans genes and the modification of more than 40% of them. This collection of mutants, generated under the auspices of the European NEMAGENETAG consortium, is publicly available and represents an important research resource

Prevalence and Factors Contributing to Daytime and Nocturnal Hypoxemia in Chronic Heart Failure Patients

International audienceBackground: Despite clinical optimization, many chronic heart failure (CHF) patients remain symptomatic with dyspnea and poor quality of life. Study Objective: While oxygen therapy is prescribed in severe cases, the actual prevalence of different patterns of hypoxemia is unknown. Methods: We analyzed 183 stable CHF patients with optimized medical treatment in the “MARS” database. The patients underwent cardiorespiratory sleep recording and complete daytime pulmonary function tests including arterial blood gases. Results: This prospective cohort was predominately male (86.3%) with a mean age of 67.3 years (59.3; 75.7) and a mean BMI of 26.7 kg/m2 (23.7; 31.1). The patients were mainly in NYHA classes II and III with a mean left ventricular ejection fraction of 38%. 102 (55.61%) patients had ischemic cardiomyopathy with multiple comorbidities, and 64 (35.06%) had airflow obstruction. 8 (4.37%) patients had hypoxemia both day and night, and 151 (82.5%) had nocturnal hypoxemia only. All but 3 patients had sleep-disordered breathing (SDB), and either obstructive (59%) or central sleep apnea (39%) with a mean apnea-hypopnea index of 29.59/h (16.48; 48.27), an oxygen desaturation index of 27.09/h (14.09; 45.25), time below 90% saturation of 18 min (2; 64), and a mean nocturnal saturation of 93% (92; 94). Univariate analysis found nocturnal hypoxemia was associated with higher BMI and NT-proBNP levels. In multivariate analysis, only sleep apnea severity (p < 0.0001) and diurnal PaO2 remained significant. Conclusion: Most stable CHF patients suffer from nocturnal hypoxemia, while daytime hypoxemia is relatively rare. The degree of nocturnal hypoxemia depends on the severity of SDB. Hypoxemia phenotyping and severity could help better evaluate the need for appropriate therapy in CHF patients

Influence of Intention to Adhere, Beliefs and Satisfaction About Medicines on Adherence in Solid Organ Transplant Recipients

International audienceIntroduction Nonadherence to immunosuppressive (IS) therapy is associated with poor outcomes. Identifying factors predicting poor adherence is therefore essential. The primary objective of this study was to test whether parameters of a model adapted from the theory of planned behavior, and more specifically attitudes that are influenced by beliefs and satisfaction with medication, could predict adherence in solid organ transplant patients.Methods Adherence was assessed with a self-reported medication adherence scale and IS blood trough concentrations over 6 months, in four transplant units. Satisfaction and beliefs were assessed using the Treatment Satisfaction with Medicines Questionnaire (SATMED-Q) and Beliefs about Medicines Questionnaire (BMQ), respectively. Theory of planned behavior was assessed with a specific questionnaire exploring intentions, subjective norms, attitudes and perceived behavioral control. Treatment characteristics and socioeconomic data were also collected.Results One hundred and fifty-three solid organ transplant patients were enrolled, including lung (n=33), heart (n=43), liver (n=42), and kidney (n=44) patients. Satisfaction and positive beliefs about medication were higher in adherent than those in nonadherent patients. Factors independently associated with an increased risk of nonadherence were negative general beliefs about medications (odds ratio [OR]=0.89 [0.83–0.97]), living alone (OR=2.78 [1.09–7.09]), heart transplantation (OR=3.49 [1.34–9.09]), and being on everolimus (OR=5.02 [1.21–20.8]).Conclusion Negative beliefs toward medications were shown to be an independent risk factor of poor adherence. Therefore, the BMQ could be an effective, easy to implement tool, for use in everyday practice, to identify patients needing interventions to improve adherence to IS

Disk Diffusion Testing for Detection of Methicillin-Resistant Staphylococci: Does Moxalactam Improve upon Cefoxitin?

International audienceDisk diffusion testing is widely used to detect methicillin resistance in staphylococci, and cefoxitin is currently considered the best marker for mecA-mediated methicillin resistance. In low-inoculum diffusion testing (colony suspension at 106 CFU/ml), the addition of moxalactam in combination with cefoxitin has been reported to improve on cefoxitin alone for the detection of methicillin-heteroresistant staphylococci. However, moxalactam is absent from EUCAST and CLSI guidelines, which use high-inoculum diffusion testing (colony suspension at 108 CFU/ml), calling into question the potential interest of including moxalactam in their recommendations. The inhibition zone diameters of cefoxitin and moxalactam, alone and in combination, were evaluated for concordance with mecA and mecC positivity in a large collection of clinical Staphylococcus isolates (611 Staphylococcus aureus, Staphylococcus lugdunensis, and Staphylococcus saprophyticus isolates and 307 coagulase-negative staphylococci other than S. lugdunensis and S. saprophyticus isolates, of which 22% and 53% were mecA-positive, respectively) and in 25 mecC-positive S. aureus isolates using high-inoculum diffusion testing. Receiver operating characteristic, sensitivity, and specificity analyses indicated that the detection of mecA- and mecC-positive and negative isolates did not improve with moxalactam, either alone or in combination with cefoxitin, compared to cefoxitin alone. These findings were similar in both the S. aureus/S. lugdunensis/S. saprophyticus group and in the coagulase-negative staphylococci group. Our results do not support the use of moxalactam as an additional marker of methicillin resistance when testing with high-inoculum disk diffusion

Distribution of <i>Mos1</i> alleles.

<p>(A) Graph showing the relationship between chromosome length (as a percentage of the whole nuclear genome) and the proportion of <i>Mos1</i> alleles per chromosome reported in a previous study <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0030482#pone.0030482-Granger1" target="_blank">[5]</a>, and the 10,858 alleles obtained in the current project (black and red circles, respectively). The outliers, concerning chromosomes I and V, from the previous study are highlighted with lines. (B) Distribution of distances from one <i>Mos1</i> allele to the next, in a 5′ to 3′ direction along each chromosome. The graph shows the cumulative percentage of alleles that are separated by less than the indicated distance. (C) Concentration of <i>Mos1</i> alleles at the extreme right end of chromosome I (length 15,072,423 bp). The separation of the allele numbers indicates that almost all the alleles were generated independently, except in two cases (ttTi2276 and ttTi2284; ttTi13453 and ttTi13460), highlighted by an asterisk. This region was also preferentially targeted during the previous study as reflected by the presence of several cxTi alleles.</p

Genomic coverage of <i>Mos1</i>.

<p>Graphical representation of each <i>C. elegans</i> chromosome showing the regions of the genome that are potentially amenable to genome engineering using the publicly-available <i>Mos1</i> alleles; it is assumed that any point up to 1.5 kb away from a transposon-insertion site can be targeted. The bottom line is a magnified view of the boxed region on chromosome X.</p