Discovery of novel methanone derivatives acting as antimycobacterial agents

A series of pyrazoline derivatives were synthesized and in vitro activity against Mycobacterium tuberculosis H37Rv was carried out. Among the synthesized compounds, compounds (4d) and (4f) 4-aminophenyl-3-(3,4-dimethoxyphenyl)-6,7-dimethoxy-2,3,3a,4-tetrahydroindeno[1,2-c]pyrazol-2-ylmethanone and 4-aminophenyl-6,7-dimethoxy-3-phenyl-2,3,3a,4-tetrahydroindeno[1,2-c]pyrazol-2-ylmethanone were found to be the most active agent against M. tuberculosis H37Rv with a minimum inhibitory concentration of 10 μg/mL.     

Influence of marital status and employment status on long-term adherence with continuous positive airway pressure in sleep apnea patients

Background

Long-term adherence is a major issue in patients receiving home continuous positive airway pressure (CPAP) therapy for obstructive sleep apnea-hypopnea syndrome (OSAHS). In a multicenter prospective cohort (the Institut de Recherche en Santé Respiratoire des Pays de la Loire [IRSR] sleep cohort) of consecutive OSAHS patients in whom CPAP had been prescribed for at least 90 days, we studied the impact on long-term treatment adherence of socioeconomic factors, patients and disease characteristics prior to CPAP initiation.

Methods and Principal Findings

Among 1,141 patients in whom CPAP had been prescribed for an average of 504±251 days (range: 91 to 1035), 674 (59%) were adherent with a mean daily use of CPAP≥4 h (mean: 6.42±1.35 h). Stepwise regression analysis identified 4 independent factors of CPAP adherence including apnea-hypopnea index (AHI) (OR: 1.549, 95%CI 1.163 to 2.062 for AHI≥30 vs. AHI<30; p = 0.003), body mass index (BMI) (OR: 1.786, 95%CI 1.131 to 2.822 for BMI≥25 and <30 kg/m², p = 0.01; OR: 1.768, 95%CI 1.145–2.731 for BMI≥30 kg/m², p = 0.01 vs. BMI<25 kg/m²), employment status (OR: 1.414, 95%CI 1.097–1.821 for retired vs. employed; p = 0.007) and marital status (OR: 1.482, 95%CI 1.088–2.019 for married or living as a couple vs. living alone; p = 0.01). Age, gender, Epworth sleepiness scale, depressive syndrome, associated cardiovascular morbidities, educational attainment and occupation category did not influence CPAP adherence.

Conclusions

Marital status and employment status are independent factors of CPAP adherence in addition to BMI and disease severity. Patients living alone and/or working patients are at greater risk of non-adherence, whereas adherence is higher in married and retired patients. These findings suggest that the social context of daily life should be taken into account in risk screening for CPAP non-adherence. Future interventional studies targeting at-risk patients should be designed to address social motivating factors and work-related barriers to CPAP adherence.     

Combined effect of prenatal solvent exposure and GSTT1 or GSTM1 polymorphisms in the risk of birth defects

Exposure to solvents during pregnancy has long been suspected to increase the risk of congenital malformations. Glutathione S-transferases (GSTs) are enzymes essential for the detoxification of various chemicals. Our objective here was to assess whether GST polymorphisms might modify the association between maternal solvent exposure and the risk of birth defects. A prospective cohort included 3421 pregnant women in Brittany, France (2002-2006). Occupational exposure to solvents was assessed from a job-exposure matrix. Congenital malformations were diagnosed among livebirths, stillbirths, and medical pregnancy terminations. Using a nested case-control design, 32 babies with major birth defects were compared to 348 normal births for babies' cord blood genotypes (at GSTT1 and GSTM1) and maternal occupational solvent exposure. Logistic models were used to adjust for potential confounders. The risk of major defects increased significantly in women with solvent exposure (20% of controls and 34% of cases). Frequencies of the null genotype of both the GSTT1 and GSTM1 genes were similar among controls and cases. There was a significantly increased risk of birth defects in GSTM1 not-null cord-blood genotype in pregnancies exposed to solvents (odds ratio [OR], 1.0 for not-null, not-exposed; OR, 4.0 for not-null, exposed; 95% confidence interval [CI], 1.4-11.2; OR, 1.6 for null, not-exposed; 95% CI, 0.6-3.9; OR, 1.0 for null, exposed; 95% CI, 0.2-4.7; p = 0.05). This nested case-control study suggests that the child's GSTM1 genotype modifies the risk of major birth defects among offspring of solvent-exposed women. Replication and additional investigations are necessary to confirm and elucidate these findings.     

Sigmoidal equation for lung and chest wall volume-pressure curves in acute respiratory failure.

To assess incidence and magnitude of the "lower inflection point" of the chest wall, the sigmoidal equation was used in 36 consecutive patients intubated and mechanically ventilated with acute lung injury (ALI). They were 21 primary and 5 secondary ALI, 6 unilateral pneumonia, and 4 cardiogenic pulmonary edema. The lower inflection point was estimated as the point of maximal compliance increase. The low constant flow inflation method and esophageal pressure were used to partition the volume-pressure curves into their chest wall and lung components on zero end-expiratory pressure. The sigmoidal equation had an excellent fit with coefficients of determination >0.90 in all instances. The point of maximal compliance increase of the chest wall ranged from 0 to 8.3 cmH2O (median 1 cmH2O) with no difference between ALI groups. The chest wall significantly contributed to the lower inflection point of the respiratory system in eight patients only. The occurrence of a significant contribution of the chest wall to the lower inflection point of the respiratory system is lower than anticipated. The sigmoidal equation is able to determine precisely the point of the maximal compliance increase of lung and chest wall.     

Effects of the Diadromus pulchellus ascovirus,DpAV-4, on the hemocytic encapsulation response and capsule melanization of the leek-moth pupa,Acrolepiopsis assectella

DpAV-4 is a symbiotic ascovirus found in natural populations of the solitary endoparasitoid wasp Diadromus pulchellus. The female wasp injects this virus into the pupae of the leek-moth Acrolepiopsis assectella during oviposition. The ascovirus replicates in the pupal tissues and the consequent lysis of the cells occurs synchronously with egg hatching and the development of the wasp larva. We show here that encapsulation and capsule melanization were activated when minute nylon monofilaments were implanted into the hemocoel of non parasitized leek-moth pupae and that encapsulation and melanization were inhibited in pupae parasitized by D. pulchellus. When the pupae were infected by DpAV-4, melanization of the nylon monofilaments was abolished, but a capsule was still always formed. These results indicate that DpAV-4 is a free virus able to alter the defence system of the parasitized host so as to improve the development of the parasitoid wasp, D. pulchellus.     

Role of disulfide bonds in folding and activity of leiurotoxin I: just two disulfides suffice

The aim of this study is to investigate the contribution of each disulfide bond in the folding and function of leiurotoxin I, a short scorpion toxin that blocks small conductance K(+) channels. The structure of leiurotoxin I contains a motif conserved in all scorpion toxins, formed by a helix and a double-stranded beta-sheet and stabilized by three disulfide bridges. We synthesized three analogues, each presenting two alpha-aminobutyric acid (Abu) moieties replacing two bridged cysteine residues: LeTx1 ([Abu 3,21] Leiurotoxin I), LeTx2 ([Abu 8,26] Leiurotoxin I), and LeTx3 ([Abu 12,28] Leiurotoxin I). All three analogues fold into a major product containing two native disulfide bonds, while LeTx3 forms an additional isomer, containing non-native disulfides. In denaturing conditions, analogues LeTx2 and LeTx3 yield non-native isomers, while LeTx1 only forms the isomer with native disulfides. All isomers with native disulfides contain nativelike alpha-helical conformations and bind to synaptosomal membranes with affinities within a log of that shown by the native toxin. By contrast, the non-native LeTx3A analogue exhibits a disordered conformation and a decreased biological potency. Our results indicate that the "CxxxC, CxC" cysteine spacing, conserved in all scorpion toxins and preserved in LeTx1, may play an active role in folding, and that only two native disulfide bonds in leiurotoxin I are sufficient to preserve a nativelike and active conformation. Thus, in the scorpion toxin scaffold, modifications of conserved and interior cysteine residues may permit modulation of function, without significantly affecting folding efficiency and structure.     

BgK, a disulfide-containing sea anemone toxin blocking K+ channels, can be produced in Escherichia coli cytoplasm as a functional tagged protein

BgK, a sea anemone peptide consisting of 37 amino acid residues and 3 disulfide bonds, blocks voltage-gated potassium (Kv1) channels. Here, we report a method for producing tagged BgK in Escherichia coli, as a soluble cytoplasmic protein. First, using peptidic synthesis, we show that addition of a 15 residue peptide (S.Tag) at the BgK C-terminus does not affect its biological activity. Then, a synthetic DNA sequence encoding BgK was constructed and cloned to produce a BgK-S.Tag hybrid in the cytoplasm of E. coli. The presence of S.Tag did not only facilitate detection, quantification, and purification of the recombinant protein, but also increased the production yield by more than two orders of magnitude. Moreover, use of an E. coli OrigamiB(DE3)pLacI strain also increased production; up to 5.8-7.5mg of BgK-S.Tag or mutated BgK(F6A)-S.Tag was produced per liter of culture and could be functionally characterized in crude extracts. Using a two-step purification procedure (affinity chromatography and RP-HPLC), we obtained 1.8-2.8mg of purified recombinant protein per liter of culture. The recombinant peptides displayed functional properties similar to those of native BgK or BgK(F6A).     

Presence of diabetes-inhibiting, glutamic acid decarboxylase-specific, IL-10-dependent, regulatory T cells in naive nonobese diabetic mice

Immunization of NOD mice with autoantigens such as glutamic acid decarboxylase (GAD) 221-235 peptide (p221) can induce Ag-specific CD4(+) T regulatory (Tr) cells. However, it is unclear whether these Tr cells acquire their regulatory capacity due to immunization or whether they are constitutively harbored in unimmunized naive mice. To address this question, we used an I-Ag7 tetramer to isolate p221-specific T cells from naive NOD mice (N221(+) cells) after peptide-specific in vitro expansion. The N221(+) T cells produced IFN-gamma and IL-10, but very little IL-4, in response to p221 stimulation. These T cells could function as regulatory cells and inhibit in vitro proliferation of diabetogenic BDC2.5 cells. This suppressive activity was cell contact-independent and was abrogated by Abs to IL-10 or IL-10R. Interestingly, IL-2 produced by other T cells present in the cell culture induced unactivated N221(+) T cells to exhibit regulatory activities involving production of IL-10. In vivo, N221(+) cells inhibited diabetes development when cotransferred with NOD splenocytes into NOD/scid recipients. Together, these results demonstrate that p221-specific IL-10-dependent Tr cells, including Tr type 1 cells, are present in naive NOD mice. The use of spontaneously arising populations of GAD peptide-specific Tr cells may represent a promising immunotherapeutic approach for preventing type 1 diabetes.     

Genetics of nonsyndromic cleft lip with or without cleft palate: is there a Mendelian sub-entity?

The mode of inheritance of nonsyndromic cleft lip with or without cleft palate (NSCLP) is still a matter of dispute. We performed segregation analysis on three data sets of families ascertained through an affected child with NSCLP. The first two data sets were selected in France and were pooled for a global analysis. No major gene effect could be evidenced in spite of a very large number of families (666 pedigrees including 719 nuclear families). The third data set was British and consisted of three-generation families including the offspring of probands. A major gene effect, as well as a strong residual multifactorial component, were highly significant and we could show that this evidence almost entirely came from the information on probands' offspring. We conclude that a mixture of monogenic and of multifactorial cases is probably the best explanation for the observations made in this study. Analyses performed in pedigrees with multiple cases closely related might allow reducing heterogeneity and help identifying those Mendelian sub-entities.