Narrative enhancement and cognitive therapy (NECT) to improve social functioning in people with serious mental illness: study protocol for a stepped-wedge cluster randomized controlled trial

Background

Self-stigma is highly prevalent in serious mental illness (SMI) and is associated with poorer clinical and functional outcomes. Narrative enhancement and cognitive therapy (NECT) is a group-based intervention combining psychoeducation, cognitive restructuring and story-telling exercises to reduce self-stigma and its impact on recovery-related outcomes. Despite evidence of its effectiveness on self-stigma in schizophrenia-related disorders, it is unclear whether NECT can impact social functioning.

Methods

This is a 12-centre stepped-wedge cluster randomized controlled trial of NECT effectiveness on social functioning in SMI, compared to treatment as usual. One hundred and twenty participants diagnosed with schizophrenia, bipolar disorder or borderline personality disorder will be recruited across the 12 sites. The 12 centres participating to the study will be randomized into two groups: one group (group 1) receiving the intervention at the beginning of the study (T0) and one group (group 2) being a control group for the first 6 months and receiving the intervention after (T1). Outcomes will be compared in both groups at T0 and T1, and 6-month and 12-month outcomes for groups 1 and 2 will be measured without a control group at T2 (to evaluate the stability of the effects over time). Evaluations will be conducted by assessors blind to treatment allocation. The primary outcome is personal and social performance compared across randomization groups. Secondary outcomes include self-stigma, self-esteem, wellbeing, quality of life, illness severity, depressive symptoms and personal recovery.

Discussion

NECT is a promising intervention for reducing self-stigma and improving recovery-related outcomes in SMI. If shown to be effective in this trial, it is likely that NECT will be implemented in psychiatric rehabilitation services with subsequent implications for routine clinical practice.

Trial registration

ClinicalTrials.gov NCT03972735. Trial registration date 31 May 2019.

Use of artesunate in non-malarial indications

INTRODUCTION

Artesunate and other artemisinin derivatives are used in various infectious and non-infectious diseases. We aimed to analyze available data on artesunate and artemisinin derivatives activity in humans and their potential clinical benefits in non-malarial indications.

MATERIAL AND METHODS

Literature review performed on PubMed and the Cochrane Library databases using the PRISMA method. We analyzed studies published in English from January 2008 to August 2017 using the same indicators of drug efficacy.

RESULTS

We included 19 studies performed in humans (1 meta-analysis, 1 literature review, 4 randomized controlled trials, 3 prospective controlled trials, 3 prospective uncontrolled trials, 2 exploratory phase 1 or 2 trials, 1 case series, and 4 case reports). Artesunate and artemisinin derivatives demonstrated efficacy in the treatment of schistosomiasis in combination with praziquantel (P=0.003). Artesunate monotherapy was less effective than praziquantel alone (P<0.001) probably because its activity only affects the early stages of Schistosoma parasites. Artesunate monotherapy could be interesting as a chemoprophylactic drug against schistosomiasis (P<0.001). Findings seem promising but are still controversial in the treatment of multidrug-resistant CMV infections. Studies do not conclude on artesunate and artemisinin derivatives efficacy in the treatment of cervix, breast, colorectal, and lung cancers.

CONCLUSION

Artesunate and artemisinin derivatives in combination with praziquantel were effective against schistosomiasis, and could be used as a chemoprophylactic drug alone. They could be interesting as anti-CMV and anti-tumor treatment. Additional trials in humans are required to assess the efficacy of artesunate and artemisinin derivatives in diseases other than malaria.

Performance of genotypic algorithms for predicting tropism for HIV-1 CRF01_AE recombinant

OBJECTIVES

There is no consensus about the performances of genotypic rules for predicting HIV-1 non-B subtype tropism. Three genotypic methods were compared for CRF01_AE HIV-1 tropism determination.

METHODS

The V3 env region of 207 HIV-1 CRF01_AE and 178 B subtypes from 17 centers in France and 1 center in Switzerland was sequenced. Tropism was determined by Geno2Pheno algorithm with false positive rate (FPR) 5% or 10%, the 11/25 rule or the combined criteria of the 11/25, net charge rule and NXT/S mutations.

RESULTS

Overall, 72.5%, 59.4%, 86.0%, 90.8% of the 207 HIV-1 CRF01_AE were R5-tropic viruses determined by Geno2pheno FPR5%, Geno2pheno FPR10%, the combined criteria and the 11/25 rule, respectively. A concordance of 82.6% was observed between Geno2pheno FPR5% and the combined criteria for CRF01_AE. The results were nearly similar for the comparison between Geno2pheno FPR5% and the 11/25 rule. More mismatches were observed when Geno2pheno was used with the FPR10%. Neither HIV viral load, nor current or nadir CD4 was associated with the discordance rate between the different algorithms.

CONCLUSION

Geno2pheno predicted more X4-tropic viruses for this set of CRF01_AE sequences than the combined criteria or the 11/25 rule alone. For a conservative approach, Geno2pheno FPR5% seems to be a good compromise to predict CRF01_AE tropism.

Prevalence of HIV-1 drug resistance in treated patients with viral load >50 copies/mL: a 2014 French nationwide study

Background

Surveillance of HIV-1 resistance in treated patients with a detectable viral load (VL) is important to monitor, in order to assess the risk of spread of resistant viruses and to determine the proportion of patients who need new antiretroviral drugs with minimal cross-resistance.

Methods

The HIV-1 protease and reverse transcriptase (RT) and integrase genes were sequenced in plasma samples from 782 consecutive patients on failing antiretroviral regimens, seen in 37 specialized centres in 2014. The genotyping results were interpreted using the ANRS v24 algorithm. Prevalence rates were compared with those obtained during a similar survey conducted in 2009.

Results

The protease and RT sequences were obtained in 566 patients, and the integrase sequence in 382 patients. Sequencing was successful in 60%, 78%, 78% and 87% of patients with VLs of 51-200, 201-500, 501-1000 and >1000 copies/mL, respectively. Resistance to at least one antiretroviral drug was detected in 56.3% of samples. Respectively, 3.9%, 8.7%, 1.5% and 3.4% of patients harboured viruses that were resistant to any NRTI, NNRTI, PI and integrase inhibitor (INI). Resistance rates were lower in 2014 than in 2009. Resistance was detected in 48.5% of samples from patients with a VL between 51 and 200 copies/mL.

Conclusion

In France in 2014, 90.0% of patients in AIDS care centres were receiving antiretroviral drugs and 12.0% of them had VLs >50 copies/mL. Therefore, this study suggests that 6.7% of treated patients in France might transmit resistant strains. Resistance testing may be warranted in all treated patients with VL > 50 copies/mL.

Mechanical clearance of red blood cells by the human spleen: Potential therapeutic applications of a biomimetic RBC filtration method

During their lifespan, circulating RBC are frequently checked for their deformability. This mechanical quality control operates essentially in the human spleen. RBC unable to squeeze though narrow splenic slits are retained and cleared from the blood circulation. Under physiological conditions this prevents microvessels from being clogged by senescent, rigid RBC. Retention of poorly deformable RBC is an important determinant of pathogenesis in malaria and may also impact the clinical benefit of transfusion. Modulating the splenic retention of RBC has already been proposed to support therapeutic approaches in these research fields. To this aim, the development of microplates for high throughput filtration of RBC through microsphere layers (microplate-based microsphiltration) has been undertaken. This review focuses on potential therapeutic applications provided by this technology in malaria chemotherapy and transfusion.

Trends in screening for prostate cancer

1542

Background: Screening for prostate cancer is still in debate. In France, there is no financial barrier for individuals to be screened with the prostate-specific antigen (PSA) test, and there is no recommendation for mass screening. Methods: Two nationwide observational studies were carried out in France. The first one, EDIFICE 1, was conducted in 2005 among a representative sample of 1504 subjects aged between 40 and 75 years and a representative sample of 600 general practitioners (GPs). The second one, EDIFICE 2, was conducted in 2008 with the same methodology. Results: General population: In 2005, 36% of the interviewed male population aged between 50 and 75 years declared having undergone a screening test, compared to 49% in 2008 (OR = 1.63 CI95% 1.25; 2.12). Prostate cancer screening increased in all age groups, however, the most significant increase can be observed in the population aged between 50 and 54 years: 18% in 2005 versus 35% in 2008 (OR = 2.43 CI95% 1.31; 4.52). This trend for increasing testing will probably be confirmed in the future since 57% of males never screened plan to undergo a test, and only 16% of those who did screening plan to stop. The expected participation in the future will be close to 70%. Physicians: In 2005, 58% of GPs systematically recommended prostate cancer screening for their male consultants ages 50 to 74, in 2008 the figure is 65% (OR = 1.32 CI95%1.04; 1.66). For prostate cancer screening, a GP's gender has no significant impact. Systematic recommendation for both breast and colorectal cancer screening has an impact on recommending prostate cancer screening as well; OR = 2.9 (CI95% 2.0–4.4) and OR = 2.0 (CI95% 1.3–3.2) respectively. The GP's age is not associated with a higher rate of systematic recommendation. Conclusions: We have observed in France a significant growth in prostate cancer screening: more persons screened, more often, at a younger age. Despite the lack of consistent evidence, persons and GPs exposed to mass communication and campaign for breast and colorectal cancer screening might infer that screening is valuable for other conditions.

No significant financial relationships to disclose.

Trends in screening for colorectal cancer in France

1538

Background: In France, after a pilot population-based screening program in 23 districts (2002–2003), a national organized program was progressively implemented starting in 2005. The EDIFICE 2 survey was conducted in 2008, 3 years after EDIFICE 1, to provide a better understanding of French people's participation in colorectal screening programs and to assess the evolution between the two periods. Methods: This second nationwide observational study, EDIFICE 2, was conducted in January 2008 among a representative sample of 1,801 subjects aged between 40 and 85 years old. The analysis focused on the target population of the national screening program (50–74 years old). Results: In 2008, 38% of subjects between 50 and 74 years (N = 928) had undergone a screening test for colorectal cancer (including fecal test or colonoscopy) versus 25% in 2005 (p < 0.05); 32% of the unscreened population (N = 575) planned to undergo a test. Colorectal cancer screening increased significantly in all age groups, especially between 65 and 69 years, and for both sexes. A most significant increase can be observed in districts with pilot programme (+ 21%). Factors influencing the probability of screening were: being encouraged by the family circle, living in a couple, the existence of a case of cancer (especially colorectal cancer) in the family circle, and fear of colorectal cancer. The main reasons for not performing the screening were: not feeling concerned, no recommendation by the GP, carelessness, no symptoms, and fear of exams or results. Conclusions: The objective rate of participation (50%), can be reached by motivating the unscreened population already planning to perform a test. The results in the pilot districts show the effectiveness of an organization of the screening. This trend of increasing testing will probably be confirmed in the future if the reasons for non-attendance in an organized program are addressed.

No significant financial relationships to disclose.

Evolution of breast cancer screening in France from 2005 to 2008: results of the EDIFICE survey

Abstract #5010

Background: In 2005, a first EDIFICE survey was aimed to provide a better understanding of population s adherence to the screening tests available in France and results pertaining to breast cancer are reported (Int. J. Med. Sci. 2008, 5: 106-112). In 2008, EDIFICE survey is performed again to assess the evolution 3 years later. Taking into account that the Implementation of breast cancer screening has been generalized in France since 2003: All women aged between 50 and 74 years are systematically invited to perform a mammography every two years.&#x2028; Methods: This second nationwide observational survey was carried out from December 12, 2007 to January 07, 2008 among a representative samples of 1802 French people aged between 40 and 85 years and 600 general practitioners (GPs). Information collected included socio-demographic characteristics, attitude towards cancer screening and actual experience of cancer screening, as well as GPs practice regarding screening. The precision of the results is 4.3% for a 95% confidence interval.&#x2028; Results: In EDIFICE–1 and -2, 501 and 488 participating women aged between 50 and 74 years are assessed, respectively.&#x2028; &#x2028; In EDIFICE-2, there was a significant relationship (p&lt;0.05) between the existence of a first mammography screening on women s own initiative and age (odd ratio 0.35; 95%CI 0.13 – 0.95). Main factors associated with performing the screening test every two years were: knowledge of screening process (odd ratio 3.59 ; 95%CI 1.54 – 8.38), Own motivation (odd ratio 5.03; 95%CI 1.6 – 15.8), First mammography performed in the organized screening (odd ratio 6.53 ; 95%CI 1.15 – 37.3), and gynecologist consultation (odd ratio 8.68; 95%CI 2.21 – 34.11).&#x2028; Of the 600 participating GPs, 68% systematically recommended a mammography to their patients in the screening national plan. GPs perceptions of the reasons for women s avoidance of the screening test were unwillingness to be aware of mammography results (46%) and négligence (24%).&#x2028; Conclusion: The main result of this second EDIFICE Survey is to stress the impact of the breast cancer screening in France. Between 2005 and 2008 the rate of women s attendance at mammography screening has increased and the proportion of women who repeat the test every two years has been dramaticaly improve.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5010.

Breast cancer screening in France: results of the EDIFICE survey

BACKGROUND

The EDIFICE survey aimed to investigate the compliance of the general population to the screening tests available in France for the 4 most common cancers: breast, colorectal, prostate and lung. Implementation of breast cancer screening has been generalized in France since 2003: women aged between 50 and 74 years are systematically invited to perform a mammography every second year. Results pertaining to breast cancer are reported hereafter.

METHODS

This nationwide observational survey was carried out in France from 18 January to 2 February 2005 among representative samples of 773 women aged between 40 and 75 years and 600 general practitioners (GPs). Information collected included socio-demographic characteristics, attitude towards cancer screening and actual experience of cancer screening, as well as GPs' practice regarding screening. The precision of the results is +/- 4.3% for a 95% confidence interval.

RESULTS

Among the 507 participating women aged between 50 and 74 years, 92.5% (469/507) had undergone at least one mammography: 54.6% (256/469) underwent this test on their own initiative and 44.6% (209/469) of women performed it in the framework of a systematic screening plan. Most women participating in the systematic screening (89.0% i.e. 186/209) had a mammography within the last dating from less than 2 years versus 73.8% (189/256) of those who performed it outside the screening program (Chi(2) test; p<0.01). Interestingly, 422 women (61.9% i.e. 422/682 women aged between 40-75 years with at least one mammography) had performed a mammography before the recommended age for screening. There was a significant correlation (p = 0.009) between the existence of a first mammography before 50 years of age and subsequent screening on women's own initiative (54.6% of 469 screened women). Main reasons for not performing the screening test every second year (77 women aged between 50-74 years) included: feeling unconcerned and/or unmotivated (p = 0.0001), no cancer anxiety (p = 0.020) and no recommendation by the GP (p = 0.015); Of the 600 participating GPs, 68.6% (412/600) systematically recommended a mammography to their patients. GPs' perceptions of the reasons for women's avoidance of the screening test were unwillingness to be aware of mammography results (44.4% - 266/600) and the belief that mammography was painful (52.5% - 315/600).

CONCLUSION

The main result of the EDIFICE survey is the high rate of women's attendance at mammography screening. The EDIFICE survey pointed out that systematic and organized screening played a major role in the regularity of screening tests for breast cancer every second year. GPs and gynaecologist are key actors in heightening public awareness.

Mammography screening in France: Results of EDIFICE study

10701

Background: The EDIFICE study aimed to allow better understanding of population’s adhesion to the screening tests available for the 4 most frequent cancers: breast, colorectal, prostate and lung. Implementation of breast cancer screening (CS) was generalized since 2003 in France: women aged between 50 and 74 years are invited to do a mammography (M) every second year. Methods: This nationwide observational study was the first implemented in France (from January 18th to February 2nd, 2005) among a representative sample of 1504 subjects aged between 40 and 75 years including 773 women and a representative sample of 600 general practitioners (GPs). Information about participating subjects included socio-demographic characteristics, attitude towards CS and actual experience of CS, and about GPs’ medical practice regarding CS. Results: Among the 507 participating women (PW) aged between 50 and 74 years, 93% had done at least one M: 55% underwent this test on their own initiative and 45% of PW had it during a systematic screening plan. Most PW in the systematic screening (89%) had a M dating from less than 2 years vs 74% of the others (X2 = 18.9; p < 0,01). Main reasons for not performing the biennial screening test were: lack of care (18%), “it’s not a priority” (18%) and no advice from the GPs (15%). 79% of the PW had at least one M before 50 years (1st test at the mean age of 37.9±6 years). Among the 600 GPs, 68% systematically recommended M to their patients. GPs’ perceptions of the reasons for women’s avoidance of screening test were their unwillingness to be aware of M results (44%) and their belief in painful symptoms related to M (52%). Conclusions: This first nationwide study has shown the high rate of PW’s attendance at M screening. It pointed out that systematic and organized screening played a major role in regularity of screening over 2 years, and GP is a key actor in heightening public awareness.

No significant financial relationships to disclose.

Impact of organization of colorectal cancer screening: Results of EDIFICE study

6078

Background: The EDIFICE study aimed to allow better understanding of population’s adhesion to the tests available for the 4 most frequent cancers: breast, colorectal, prostate and lung. In 1998 the French National Consensus Conference advocated for mass cancer screening (CS) using Hemoccult II. The departments are divided according to the existence or not of an organized program: this screening was organized in 22 departments (3 “scout” started in 1998, 9 “first wave” in 2003 and 12 “second wave” in 2004). Results are reported hereunder. Methods: This first nationwide observational study was carried out in France from January 18th to February 2nd, 2005 among a representative sample of 1504 subjects aged between 40 and 75 years and a representative sample of 600 general practitioners (GPs). Information about participating subjects included socio-demographic characteristics, attitude towards CS, and about GPs’ medical practice regarding CS. Results: Only 25% of the 970 subjects aged between 50 and 74 years had undergone a colorectal screening test. In the organized departments (OD), the rate of persons who self-report any colorectal cancer screening was 34% vs 20% in unorganized departments (UD) (OR=1.99, CI95% 1.47- 2.69, p<0.001). The rate of recent screening within a range of 2 years was 24% for OD vs 8% for UD (OR=3.35, CI95% 1.91- 5.88, p<0.01). The rate of “fear of the test and/or its results” was higher in OD: 11% versus 6% (OR=1.97, CI95% 1.11–3.49). The rate of GPs who advocated systematically for screening was 40%, 29%, 26% and 13% for scout, first wave, second wave OD and baseline UD respectively. Organization reduced the rate of screening based on colonoscopy alone from 69% persons in UD to 35% in the OD. Conclusions: The main result of this survey comparing data in the same frame of time, in the same country, is that organized programs for colorectal cancer impact of health outcomes.

No significant financial relationships to disclose.

Cancer screening tests in France: First results of EDIFICE study

6092

Background: The EDIFICE study was the first which aimed to allow better understanding of population’s adhesion in France to the screening tests available for the 4 most frequent cancers: breast, colorectal, prostate and lung. Methods: This nationwide observational study was carried out in France from January 18th to February 2nd, 2005 among a representative sample of 1,504 subjects aged between 40 and 75 years and a representative sample of 600 general practitioners (GPs). Information collected about participating subjects included socio-demographic characteristics, attitude towards cancer screening and actual experience of cancer screening, and about GPs’ medical practice regarding screening. Results: A striking result observed is that screening for colorectal cancer that USPSTF rates as an “A” Recommendation (strongly recommended) deserves less attention: reported rate 25% than prostate cancer screening (either with digital rectal examination and/or PSA): reported rate 36%. In the same way, GPs’ are recommended more often prostate cancer screening (58%) than colorectal cancer screening (18%). Another key result of that EDIFICE national representative survey is the high attendance rate of women at mammography screening. Conclusion: With respect to the cost of such programs, utilization must be monitored and compared among different countries/organization. Additional data will be presented about reasons to do or not cancer screening and about regularity of screening.

[Table: see text]

No significant financial relationships to disclose.

Modulation of neuronal excitability by intracellular calcium buffering: from spiking to bursting

We have investigated the detailed regulation of neuronal firing pattern by the cytosolic calcium buffering capacity using a combination of mathematical modeling and patch-clamp recording in acute slice. Theoretical results show that a high calcium buffer concentration alters the characteristic regular firing of cerebellar granule cells and that a transition to various modes of oscillations occurs, including bursting. Using bifurcation analysis, we show that this transition from spiking to bursting is a consequence of the major slowdown of calcium dynamics. Patch-clamp recordings on cerebellar granule cells loaded with a high concentration of the fast calcium buffer BAPTA (15 mM) reveal dramatic alterations in their excitability as compared to cells loaded with 0.15 mM BAPTA. In high calcium buffering conditions, granule cells exhibit all bursting behaviors predicted by the model whereas bursting is never observed in low buffering. These results suggest that cytosolic calcium buffering capacity can tightly modulate neuronal firing patterns leading to generation of complex patterns and therefore that calcium-binding proteins may play a critical role in the non-synaptic plasticity and information processing in the central nervous system.

Role of calcium binding proteins in the control of cerebellar granule cell neuronal excitability: experimental and modeling studies

Calcium binding proteins, such as calretinin, are abundantly expressed in distinctive patterns in the central nervous system but their physiological function remains poorly understood. Calretinin is expressed in cerebellar granule cells which provide the major excitatory input to Purkinje cells through parallel fibers. Calretinin deficient mice exhibit dramatic alterations in motor coordination and in Purkinje cell firing recorded in vivo through unknown mechanisms. In the present paper, we review the results obtained with the patch clamp recording techniques in acute slice preparation. This data allow us to investigate the effect of a null mutation of the calretinin gene on the intrinsic electroresponsiveness of cerebellar granule cells at a mature developmental stage. Calretinin deficient granule cells exhibit faster action potentials and generate repetitive spike discharge showing an enhanced frequency increase with injected currents. These alterations disappear when 0.15 mM of the exogenous fast calcium buffer BAPTA is infused in the cytosol to restore the calcium buffering capacity. Furthermore, we propose a mathematical model demonstrating that the observed alterations of granule cell excitability can be explained by a decreased cytosolic calcium buffering capacity due to the absence of calretinin. We suggest that calcium binding proteins modulate intrinsic neuronal excitability and may therefore play a role in the information processing in the central nervous system.

Simultaneous microbatch screening of enantiorecognition on solid chiral selectors using selected mixtures of test-racemates: a case study on cellulose tris(alpha-phenylpropionate) with configurational diversity

An improved methodology for microbatch screening in the liquid-solid enantioselective adsorption of racemates by solid chiral selector is presented and illustrated by the evaluation of a series of six cellulose tris(alpha-phenylpropionate) presenting a configurational diversity and cellulose tris (4-methylbenzoate). Analyses were performed on 5 mg scale of chiral selector and 150 microL of supernatant containing a mixture of three test-racemates. Fifteen test-racemates were chosen according to their molecular diversity using a hierarchical clustering approach for seven selected three-dimensional molecular properties. The 15 racemates were sorted in five test mixtures composed of three racemates each according to the following constraints: each triplet of test-racemates can be analyzed without peak overlap on a commercially available chiral stationary phase (CSP). The designed five groups of three racemates may be used for the evaluation of other chiral selectors in view of the preparation of CSPs. This methodology improves the throughput of the evaluation and could be automated.

Isolated mitral valve replacement with St. Jude medical prosthesis: long-term results: a follow-up of 19 years

BACKGROUND

In this retrospective study, approximately 440 patients received mitral valve replacements with the St Jude Medical prosthesis. The last patient was operated on 10 years before the beginning of the follow-up. The extended follow-up was 19 years.

METHODS AND RESULTS

Four hundred forty patients (sex ratio, 1.32 [men to women]; age, 60+/-11.4 years; age range, 7 to 75 years) were operated on from 1979 to 1987. All patients underwent isolated mitral valve replacement. Tricuspid plasty was the only associated procedure. The follow-up at 19 years was 98% complete. The overall actuarial survival rate was 63+/-3.3% at 19 years, and the actuarial survival rate (only valve related) was 83+/-2.7%. The operative mortality rate (0 to 30 days) was 4.09%. We found that 89.4% of the patients alive at 19 years were in NYHA class I/II. Multivariate analysis showed that age and sex were significantly correlated with valve-related mortality and that age, sex, NYHA class, and atrial fibrillation were significantly correlated with overall mortality. The linearized rates (percent patient-years) of thromboembolism, thrombosis, and hemorrhage were 0.69, 0.2, and 1, respectively. At 19 years, freedom from endocarditis and reoperation was 98.6+/-1% and 90+/-3%, respectively.

CONCLUSIONS

In this study, the very-long-term results confirm the excellent durability of the St Jude Medical prosthesis in the mitral position and show the difficulty of adjusting the anticoagulation protocol, even after long-term treatment.

Reviewing mobile phases used on Chiralcel OD through an application of data mining tools to CHIRBASE database

During the past decade, thousands of compounds have been resolved on Chiralcel OD (a cellulose-based chiral stationary phase) under diverse eluting conditions. Many researches have documented the effects of mobile phase on enantioselectivity for a given family of samples but today no comprehensive study aimed at identifying the associations between the structural features present on solute and appropriate mobile phase conditions has yet been proposed. In this review of mobile phases used on Chiralcel OD, we try to go far beyond a simple enumeration of eluting conditions and an effort is made to explore the utility of data mining tools for assessing the knowledge contained in CHIRBASE database. We have extracted from CHIRBASE the chemical features of 2363 chiral compounds separated on Chiralcel OD and their corresponding mobile phases. This data set was submitted to data mining programs for molecular pattern recognition and mobile phase predictions for new cases. Some substructural characteristics of solutes were related to the efficient use of some specific mobile phases. For example, the application of CH3CN/salt buffer at pH 6-7 was found convenient for reversed-phase separation of compounds bearing a tertiary amine functional group. Furthermore, a cluster analysis allowed the arrangement of the mobile phases according to similarity found in molecular patterns of solutes. A decision tree, which may lead to a more rational choice of the mobile phase under reversed-phase conditions, is also proposed.

Enantioselective correlation between retention factor and lipophilicity index in chiral separation on cellulose and amylose tris(3,5-dimethylphenylcarbamate) CSPs in reversed mode: A case study

For a series of alkyl substituted N-arylthiazoline-2-(thi)one atropisomers 1-14, lipophilicity indexes log kw obtained by polycratic RP-HPLC were compared to ln k(+)-S and ln k(-)-R obtained on CHIRALCEL OD-R(R) (reversed mode) and CHIRALPAK AD-RH(R) (reversed mode). Linear correlations were obtained in most cases. It appears that the correlation lines for R and S enantiomers may be parallel, convergent, or divergent, accounting for the observed alpha variation in going from methyl to tert-butyl series. Some tentative hypothesis are given as future investigation routes. Copyright 2000 Wiley-Liss, Inc.

Minerals controlling arsenic and lead solubility in an abandoned gold mine tailings

Numerous areas have been contaminated by heavy metals and metalloids due to industrial and mining activities. Studies investigating the behavior of such contaminants in the environment have identified speciation as a key factor controlling their mobility, availability and toxicity. Here we characterize As- and Pb-bearing phases resulting from the oxidation of sulfide-rich tailings of a former gold mine (La Petite Faye, France) in order to assess the risk for water quality. Elements were first pre-concentrated by granulometric fractionation (sedimentation in deionized water) and then investigated using X-ray diffraction and electron microprobe analyses. Two main As-Pb-bearing minerals were clearly identified: scorodite (FeAsO4 x 2H2O) and beudantite PbFe3(AsO4)(SO4)(OH)6. Minor amounts of As and Pb were dissolved in deionized water during granulometric fractionation, indicating the possible presence of other soluble Pb-sulfates which could be some of the primary metastable products of sulfide oxidation. This dissolution also provides information about the fate of these phases in the case of intensive leaching of the tailings. Scorodite may not be considered as a relevant candidate for As on-site immobilization, because its solubility largely exceeds drinking water standards whatever the pH. Since beudantite solubility has not yet been determined, an estimation of its solubility product was obtained using the Gibbs free energy of formation of plumbojarosite [Pb0.5Fe3(SO4)2(OH)6]. This estimation suggests that beudantite should efficiently maintain low Pb concentration in waters. However, Pb dissolution in deionized water during the granulometric fractionation led to Pb concentrations much higher than the French and US drinking water standards (2.4 x 10(-7) mol l(-1)), which may be due to dissolution of the suspected metastable Pb-sulfates. Accurate determination of beudantite solubility is now required to improve the Pb risk assessment on such polluted sites.

Increased endothelium--monocyte interactions in salt-sensitive hypertension: effect of L-arginine

Although adhesion of monocytes to endothelial cells is considered as one of the initial factors leading in the long term to the development of atherosclerosis, the effects of hypertension on monocyte-endothelial cell interactions are still largely unknown. Thus we evaluated whether hypertension affects adhesion of monocytes on rat carotid endothelium, and whether this adhesion may be modified by long-term treatment with L-arginine, the physiologic precursor of nitric oxide (NO). Hypertension was induced in Dahl rats using a sodium-rich diet (8%), in the absence or the presence of L-arginine (1.25 g/L in drinking water). After 1 month, the carotid arteries were isolated, opened longitudinally, and incubated in the presence of 2 x 10(6) monocytes previously rendered fluorescent by incubation with tetramethyl rhodamine isothiocyanate (TRITC), and adherent cells were counted under fluorescence microscopy. In parallel, the production of NO was evaluated in vitro in isolated aorta and isolated hearts. Hypertension markedly increased adhesion of monocytes on carotid endothelium, and this was reduced by L-arginine. Hypertension also reduced an index of NO release at the level of the aorta and the coronary circulation. This impaired release of NO was partially prevented by L-arginine. Thus hypertension was associated with an increased adhesion of monocytes, which is probably due at least in part to a decreased production of NO. The increased adhesion was partly reduced by L-arginine, possibly secondary to an increased production of NO. Such an increased adhesion of monocytes may contribute the increased cardiovascular risk in hypertension.

Optimization of HPLC-ICP-AES for the determination of arsenic species

High performance liquid chromatography coupled to ICP-AES detection provides a rapid, reliable and sensitive method for arsenic speciation. The separation of As(III), As(V), DMA and MMA was achieved with ion exchange chromatography coupled to an axially-viewed sequential ICP-AES. After optimization of the chromatographic parameters (pH and concentration of the mobile phase), a careful study of the interface was conducted. Five nebulizers associated to three spray chambers were tested. Response of the ICP to each arsenic species was strongly affected by the selection of the nebulizer and spray chamber, however similar responses were obtained for each arsenic species. Best signal-to-noise ratios were obtained by using a microconcentric nebulizer and a cyclone spray chamber and did not affect the chromatographic resolution. Detection limits better than 10 microg L(-1) were obtained for As(III), DMA, MMA and 20 microg L(-1) for As(V), which is a significant improvement over previously published results.

Resolution of some 4-benzofurazanyl and 4-benzofuroxanyl 1, 4-dihydropyridine derivatives by chiral HPLC on whelk-o1 and some polysaccharide chiral stationary phases

The chromatographic chiral resolution of racemic methyl 1, 4-dihydro-2,6-dimethyl-5-nitro-4-benzofurazanyl-3-carboxylates 1 and 2 and their benzofuroxanyl analogues 3 and 4 were studied on Whelk-O1, Chiralcel OD-H, Chiralcel OJ, and Chiralpak AD and AS. These CSPs were selected on the basis of the results of structural searches in Chirbase. Examination of the data and cluster analysis pointed out the influence of benzofurazane-benzofuroxane change versus alpha-beta connection change on retention and enantioselectivity, respectively. The major contribution to the retention change arose from the type of heterocycle, whereas the major contribution to the enantioselectivity change came from the mode of connection (alpha or beta) almost irrespective of the nature of the heterocycle. It resulted in a similarity of behaviour between 1 and 2 on one hand and 3 and 4 on the other as far as capacity factors were concerned, and in a similarity of behaviour between 1 and 3 on the one hand and 2 and 4 on the other as far as enantioselectivities were concerned. Chiralpak AS was selected for semipreparative resolution of the enantiomers. The study of several CSPs allowed us to obtain correlations of structure with retention and enantioselectivity as well as the choice of a semipreparative support to provide the quantities for biological tests. Copyright 1999 Wiley-Liss, Inc.

Synthesis and voltage-clamp studies of methyl 1,4-dihydro-2, 6-dimethyl-5-nitro-4-(benzofurazanyl)pyridine-3-carboxylate racemates and enantiomers and of their benzofuroxanyl analogues

Racemic methyl 1,4-dihydro-2, 6-dimethyl-5-nitro-4-(benzofurazanyl)pyridine-3-carboxylates (+/-)-10 and (+/-)-11 and their benzofuroxanyl analogues (+/-)-12 and (+/-)-13 were prepared using a modified Hantzsch reaction that involved the condensation of nitroacetone with methyl 3-aminocrotonate and the appropriate aldehydes. The racemic mixtures were resolved into the corresponding enantiomers. Whole-cell voltage-clamp studies on L-type Ca2+ channels expressed in a rat insulinoma cell line (RINm5F) showed that all the dextrorotatory antipodes were effective agonists of L-type Ca2+ currents, while the levorotatory ones were weak Ca2+ entry blockers. The (+)-enantiomer of benzofurazan-5'-yl derivative 11 demonstrated unusual activity in that, in addition to producing a potentiation of L-type currents, it interfered with the voltage-dependent gating of L-type channels by producing a net delay of their activation at low voltages. This compound represents an interesting tool to probe L-type Ca2+ channel structure and function.

[Analysis and quantification of longitudinal contraction of the left ventricle in myocardial infarction. Value of Doppler myocardial tissue imaging]

The authors compared the results of conventional 2D echocardiography and those of Doppler tissue imaging in 30 patients in the intensive care unit for acute pulmonary myocardial infarction and 10 normal control subjects, to assess the longitudinal contraction of the left ventricle. Echocardiography was performed in the apical 2 and 4 chamber views to analyse the septal, lateral, posterior and anterior left ventricular walls. Each wall was divided into 3 segments: basal, median and apical. Each segment was scored: 1-normo or hyperkinetic, 2-hypokinetic, 3-akinetic and 4-dyskinetic. Doppler tissue imaging provided the maximum instantaneous velocities in systole and diastole in each segment. In control subjects, the myocardial velocities decreased significantly from the base to the apex, resulting in a systolic and diastolic pressure gradient with each wall between the base and the apex. In patients with myocardial infarction, the myocardial velocities were decreased compared with the control group. Moreover, the myocardial velocity gradient between the base and apex was significantly reduced in the hypo and akinetic walls, both in systole and diastole. These results show that, in myocardial infarction, the longitudinal left ventricular contraction is abnormal and may be analysed and quantified by new indices of myocardial systolic and diastolic function, provided by Doppler tissue imaging.