French consensus procedure for neuropsychological assessment in multiple sclerosis.

Cognitive impairment is one of the invisible symptoms of Multiple sclerosis (MS), which could be associated with depression, unemployment, reduced social interaction, inability to drive, and compromised quality of life. Moreover, the presence of cognitive impairment can be considered as a long-term prognostic factor and in the follow-up of disability. So, cognitive assessment is a crucial element in clinical follow-up of patients with MS (pwMS). International recommendations mention the use of the Brief International Cognitive Assessment in MS (BICAMS). The BICAMS, that has been recently validated in French is a brief non-exhaustive assessment, developed as a short screening battery, hence needing other supplemented tests. The present paper aims to propose a consensus, approved by expert French consensus from the Cognition group of the SF-SEP (http://sfsep.org [Société Francophone de la Sclérose en Plaques]), for cognitive assessment of pwMS suggesting the tools that should be used in order to apprehend the other cognitive impairments that could appear in MS.

Using the FIB-4, automatically calculated, followed by the ELF test in second line to screen primary care patients for liver disease.

The objective of our work was to evaluate the screening of hepatic fibrosis in primary care using the FIB-4 score, automatically calculated. When the FIB-4 was ≥ 1.3, it was defined as positive, and ELF Test was performed. FIB-4 positivity was confirmed when ELF Test was ≥ 9.8 indicating an advanced fibrosis. Among the 3427 patients included, 869 (25%) had a positive FIB-4 score, 784 (22.5%) at intermediate (FIB-4: 1.3-2.67), and 85 (2.5%) at high risk of fibrosis (FIB-4 > 2.67). 509 (59%) of the FIB-4 positive were confirmed by the ELF Test. The percentage of confirmation was significantly higher in patients over 65 years (83 vs. 57%), with FIB-4 > 2.67 (80 vs. 56%), BMI > 25 (47 vs. 37%), and diabetes (24 vs. 14%), p = 0.001). In patients without known liver disease (92%), the practitioner identified a cause of disease in 27% of cases: mainly NAFLD and alcohol. Liver fibrosis was suspected on FIB-4 in 25% of patients in primary care. The ELF Test, performed as a second-line, improves the screening of liver fibrosis, particularly for FIB-4 intermediate results. A positive FIB-4 test allows physicians to recognize a liver disease, providing an opportunity for timely intervention.Clinical trial registration: Comité de protection des personnes du sud-ouest et outre-mer SI18.00832.201865-MS04-IDRCB 2018-A01571-54.

Functional and dysfunctional impulsivities changes after subthalamic nucleus-deep brain stimulation in Parkinson disease.

OBJECTIVES: We investigated changes of impulsivity after deep brain stimulation (DBS) of the subthalamic nucleus (STN) in Parkinson's disease (PD) patients, distinguishing functional from dysfunctional impulsivity and their contributing factors. METHODS: Data of 33 PD patients treated by STN-DBS were studied before and 6 months after surgery: motor impairment, medication (dose and dopaminergic agonists), cognition, mood and occurrence of impulse control disorders. Impulsivity was assessed by the Dickman Impulsivity Inventory, which distinguishes functional impulsivity (FI), reflecting the potential for reasoning and rapid action when the situation requires it, and dysfunctional impulsivity (DI), reflecting the lack of prior reasoning, even when the situation demands it. The location of DBS leads was studied on postoperative MRI using a deformable histological atlas and by compartmentalization of the STN. RESULTS: After STN-DBS, DI was significantly increased (mean pre- and postoperative DI scores 1.9±1.6 and 3.5±2.4, P<0.001) although FI was not modified (mean pre- and postoperative FI scores 6.2±2.7 and 5.8±2.6). Factors associated with a DI score's increase≥2 (multivariable logistic regression model) were: low preoperative Frontal Assessment Battery score and location of the left active contact in the ventral part of the STN. CONCLUSION: Our study suggests that STN-DBS may have a different impact on both dimensions of impulsivity, worsening pathological impulsivity without altering physiological impulsivity. The increase in dysfunctional impulsivity may be favoured by the location of the electrode in the ventral part of the STN.

Alexithymia in multiple sclerosis: Clinical and radiological correlations.

BACKGROUND: Alexithymia, meaning no words for emotions is a common problem that could affect up to 53% of patients in multiple sclerosis (MS). OBJECTIVES: To determine the frequency of alexithymia in MS and investigate MS-related abnormalities in structural magnetic resonance imaging (MRI) and their associations with fatigue and cognitive functions. METHODS: Ninety-five patients at all stages of the disease were examined: 21 with clinically isolated syndromes (CIS), 30 with relapsing-remitting MS (RRMS), 21 with primary (PP) and 23 with secondary progressive MS (SPMS). Alexithymia was measured with the Toronto alexithymia scale (TAS-20) and correlated to cognitive functions, depression, and fatigue. Voxel-based morphometry MRI was analyzed to determine lesion load, cerebral and regional atrophy. RESULTS: Fifty-seven of patients had alexithymia with no significant difference between the clinical phenotypes. Alexithymic patients differed from non-alexithymic patients on fatigue, depression and information processing speed. Compared to non-alexithymic patients, alexithymic patients had decreased volumes of cerebral and cerebellar white matter and there was a significant relationship between alexithymia and decreased brainstem, thalamic and corpus callosum volume. CONCLUSION: Regardless of the phenotype of MS, alexithymia is associated with atrophy of cerebral and cerebellar white matter, brainstem, corpus callosum, and thalami.

Thalamic atrophy correlates with dysfunctional impulsivity in multiple sclerosis.

BACKGROUND: Recent studies highlight the central role of thalamic atrophy in Multiple Sclerosis (MS) related disorders. Behavioural aspects of (MS) are rarely explored but their investigation is of high interest. Dickman's Impulsiveness Inventory (DII) allows distinguishing functional impulsivity (FI) which is the ability to react fast and properly when necessary, from dysfunctional impulsivity (DI) which is a behavioural symptom corresponding to the tendency to miss forethought before acting. OBJECTIVE: This paper aims to explore whether MS patients show significantly high and pathological DI, and to evaluate the impulsivity frequency in the different forms of MS including at the early stage of the Clinically Isolated Syndrome. Furthermore, this study focused on the factors that may induce abnormal impulsivity, and the link between thalamic atrophy and dysfunctional impulsivity in patients with MS. METHODS: 95 patients with demyelinating diseases including 21 Clinically Isolated Syndrome (CIS), 30 Relapsing-Remitting MS (RRMS), 23 Secondary Progressive MS (SPMS) and 21 Primary Progressive MS (PPMS) were prospectively recruited, and covered by extensive cognitive evaluation including the BCCogSEP (French version of the Brief Repeatable Battery for Neurological disease), the CSCT (Computerized Speed Cognitive Test) for processing speed of information (PSI), the DII to measure FI and DI, the Fast BDI to evaluate depression, and the EMIF-SEP scale to study physical, cognitive and social fatigues. 3D T2-FLAIR and 3D T1-weighted MRI were analyzed using automatic segmentation tools to quantify the T2 lesion load and to measure the whole and regional brain atrophy. RESULTS: 7% showed a pathologically high DI. The level of DI tended to differ significantly depending on the MS phenotype. There was no significant difference between RRMS, SPMS and PPMS, but RRMS showed significantly higher DI than CIS patients. Cognitive fatigue (r:-0.27, p<.01), depression (r:-0.21, p=.04) but mainly PSI (r:.33, p<.001) showed a significant correlation with DI. Among the brain regions of interest, the strongest significant correlation with DI was with thalamic atrophy (r:.33, p<.001). CONCLUSION: Some MS patients show a pathologically high DI, mainly RRMS compared to CIS. Previous study highlighted impulsive traits in MS patients only in relation with the presence of depression. The present study demonstrates that depression tends to correlate with DI, but that cognitive fatigue, and mainly slowing of PSI, which is the most early and severe cognitive impairment in MS, have a stronger impact on the rise of pathological impulsive behaviour. DI in MS is linked to frontal regions but even more strongly to thalamus atrophy. This is in line with the hypothesis of a disconnection syndrome in MS that causes cognitive impairment to trigger and could have the same impact on behaviour. Hence, impulsive behaviour should be evaluated and taken into account in the care of patients with MS.

Video-oculography in multiple sclerosis: Links between oculomotor disorders and brain magnetic resonance imaging (MRI).

BACKGROUND: Eye movement abnormalities (EMA) are common in multiple sclerosis (MS). However, type and severity according to the MS stage are poorly known, especially in Radiologically Isolated Syndrome (RIS) and in Clinically Isolated Syndrome (CIS). Although MRI has been included in the MS diagnostic criteria, there may be clinical-radiological dissociation. OBJECTIVE: To analyze by video-oculography (VOG) prevalence of EMA in different MS phenotypes and study correlations with brain and cervical cord MRI T2 lesions location. METHODS: 76 participants were prospectively recruited (12 RIS, 10 CIS, 11 relapsing-remitting-MS, 10 secondary progressive-MS, 10 primary progressive MS and 23 gender and age-matched healthy controls). We analyzed fixations, anti-saccades, horizontal and vertical reflex saccades and smooth pursuit. RESULTS: EMA were frequent and of gradual severity from RIS to progressive forms. Internuclear ophthalmoplegia (INO) and centripetal hypermetria were strong arguments for the diagnosis of a demyelinating disorder versus a control population. Some EMA were linked to infratentorial T2 lesion location, but others like INO were not. CONCLUSION: This study confirm that EMA are common in all MS phenotypes, even at the earliest stages. VOG can be useful to detect demyelinating process at preclinical stage by highlighting subclinical EMA even in absence of characteristic lesions visible on MRI.

A decreasing CD4/CD8 ratio over time and lower CSF-penetrating antiretroviral regimens are associated with a higher risk of neurocognitive deterioration, independently of viral replication.

Persistent immune activation is one of the suspected causes of HIV-associated neurocognitive disorders (HAND) in cART era. The CD4/CD8 ratio has been recently showed as a marker of immune activation and HAND. Our aim was to analyze if a decrease in the CD4/CD8 ratio over time could have an impact on neurocognitive deterioration. Randomly selected HIV-infected patients were followed for neuropsychological (NP) testing during a period of almost 2 years. Tests were adjusted for age, gender, and education. Patients were divided into 5 groups: normal tests (NT), neuropsychological deficit (ND, one impaired cognitive domain), asymptomatic neurocognitive disorders (ANI), mild neurocognitive disorders (MND), and HIV-associated dementia (HAD). Risk factors for neurocognitive deterioration were analyzed. Two hundred fifty-six patients underwent NP tests and 94 participated in the follow-up. The groups were comparable. Upon neuropsychological re-testing, six patients showed clinical improvement, 30 had worsened, and 58 were stable, resulting in 42 patients presenting with HAND (45 %). The majority of HAND cases consisted of ANI (26 %) and MND (16 %). In patients whose NP performance worsened, CPE 2010 score was lower at inclusion (7.13 vs 8.00, p = 0.003) and CD4/CD8 decrease more frequent (60 vs 31 %, p = 0.008) than in those who were stable or improved. Multivariate analysis confirmed these results. A decreasing CD4/CD8 ratio during a longitudinal follow-up of randomly selected HIV-infected patients and lower CSF-penetrating regimens were independently associated with cognitive decline. Monitoring trends in CD4/CD8 ratio could contribute to identifying patients at higher risk of neurocognitive deterioration.

Demonstration of a lexical access deficit in relapsing-remitting and secondary progressive forms of multiple sclerosis.

The commonly used test to evaluate naming ability in multiple sclerosis (MS) is the Boston Naming Test (BNT). In previous studies the BNP has not shown any specific deficit in MS patients. The BNT score is obtained by adding spontaneously correct answers to correct answers obtained after semantic and phonological clues are given. Our hypothesis was that due to a lexical access deficit based on executive dysfunction, MS patients would need more clues than control subjects to normalize their performances,. Fifteen relapsing-remitting (RR) and 17 secondary progressive (SP) MS patients, and 32 controls matched for sex, age, and educational level, took the BNT. The 32 MS patients also took the BCCog (Short French battery used in MS to evaluate cognitive functions) in order to evaluate their executive functions. MS patients needed significantly more clues than matched controls to normalize their performances (P<0.001). This lexical access deficit was more frequent in the SP than in the RR group (P<0.05). A lexical access deficit inducing a denomination problem has thus been shown in MS patients. Further research should aim to better evaluate the executive functions of patients with a lexical access deficit.

Molecular evolution of a novel marsupial S100 protein (S100A19) which is expressed at specific stages of mammary gland and gut development.

S100 proteins are calcium-binding proteins involved in controlling diverse intracellular and extracellular processes such as cell growth, differentiation, and antimicrobial function. We recently identified a S100-like cDNA from the tammar wallaby (Macropus eugenii) stomach. Phylogentic analysis shows wallaby S100A19 forms a new clade with other marsupial and monotreme S100A19, while this group shows similarity to eutherian S100A7 and S100A15 genes. This is also supported by amino acid and domain comparisons. We show S100A19 is developmentally-regulated in the tammar wallaby gut by demonstrating the gene is expressed in the forestomach of young animals at a time when the diet consists of only milk, but is absent in older animals when the diet is supplemented with herbage. During this transition the forestomach phenotype changes from a gastric stomach into a fermentation sac and intestinal flora changes with diet. We also show that S100A19 is expressed in the mammary gland of the tammar wallaby only during specific stages of lactation; the gene is up-regulated during pregnancy and involution and not expressed during the milk production phase of lactation. Comparison of the tammar wallaby S100A19 protein sequence with S100 protein sequences from eutherian, monotreme and other marsupial species suggest the marsupial S100A19 has two functional EF hand domains, and an extended His tail. An evolutionary analysis of S100 family proteins was carried out to gain a better understanding of the relationship between the S100 family member functions. We propose that S100A19 gene/protein is the ancestor of the eutherian S100A7 gene/protein, which has subsequently modified its original function in eutherians. This modified function may have arisen due to differentiation of evolutionary pressures placed on gut and mammary gland developmental during mammal evolution. The highly regulated differential expression patterns of S100A19 in the tammar wallaby suggests that S100A19 may play a role in gut development, which differs between metatherians and eutherians, and/or include a potential antibacterial role in order to establish the correct flora and protect against spiral bacteria in the immature forestomach. In the mammary gland it may protect the tissue from infection at times of vulnerability during the lactation cycle.

Evolutionary history of almond tree domestication in the Mediterranean basin.

Genetic diversity of contemporary domesticated species is shaped by both natural and human-driven processes. However, until now, little is known about how domestication has imprinted the variation of fruit tree species. In this study, we reconstruct the recent evolutionary history of the domesticated almond tree, Prunus dulcis, around the Mediterranean basin, using a combination of nuclear and chloroplast microsatellites [i.e. simple sequence repeat (SSRs)] to investigate patterns of genetic diversity. Whereas conservative chloroplast SSRs show a widespread haplotype and rare locally distributed variants, nuclear SSRs show a pattern of isolation by distance with clines of diversity from the East to the West of the Mediterranean basin, while Bayesian genetic clustering reveals a substantial longitudinal genetic structure. Both kinds of markers thus support a single domestication event, in the eastern side of the Mediterranean basin. In addition, model-based estimation of the timing of genetic divergence among those clusters is estimated sometime during the Holocene, a result that is compatible with human-mediated dispersal of almond tree out of its centre of origin. Still, the detection of region-specific alleles suggests that gene flow from relictual wild preglacial populations (in North Africa) or from wild counterparts (in the Near East) could account for a fraction of the diversity observed.

[Fetal atrioventricular interval measurement: technical aspects]. / Comment mesurer le temps de conduction auriculo-ventriculaire fœtal : aspects pratiques en échographie.

Atrioventricular (AV) interval measurement allows early diagnosis of isolated congenital heart block linked to maternal antibodies anti-Ro/SSA and/or anti-La/SSB. Simple and reliable ultrasound techniques have been developed to assess AV interval but most of them are imperfectly implemented by sonographers. In threatening conditions fetus should be regularly screened between 16 to 30 weeks. Increased AV interval defines the first degree AV block which should be treated by maternal-fetal corticosteroid to prevent complete heart block occurrence. The most recent ultrasound methods are based on pulsed Doppler rather than time-motion Doppler. We describe the most important technical aspects to improve the evaluation of the fetal AV interval.

Predicting fluid responsiveness in mechanically ventilated children under general anaesthesia using dynamic parameters and transthoracic echocardiography.

BACKGROUND: Dynamic variables are accurate predictors of fluid responsiveness in adults undergoing mechanical ventilation. They can be determined using respiratory variation in aortic flow peak velocity (▵Vpeak), arterial pulse pressure [▵PP and pulse pressure variation (PPV)], or plethysmographic waveform amplitude [▵POP and pleth variability index (PVI)]. These indices have not been validated in children. We studied the ability of these variables to predict fluid responsiveness in mechanically ventilated children. METHODS: All results are expressed as median [median absolute deviation (MAD)]. Thirty mechanically ventilated children were studied after undergoing general anaesthesia. Mechanical ventilation was maintained with a tidal volume of 10 ml kg(-1) of body weight. ▵PP, PPV, ▵POP, PVI, ▵Vpeak, and aortic velocity-time integral were recorded before and after volume expansion (VE). Patients were considered to be responders to VE when the aortic velocity-time integral increased more than 15% after VE. RESULTS: VE induced significant changes in ▵PP [13 (MAD 4) to 9 (5)%], PPV [15 (5) to 9 (5)%], ▵POP [15 (10) to 10 (6)%], PVI [13 (6) to 8 (5)%], and ▵Vpeak [16 (9) to 8 (3)%] (P<0.05 for all). Differences in ▵PP, ▵POP, PPV, and PVI did not reach statistical significance. Only ▵Vpeak was significantly different between responders (R) and non-responders (NR) to VE [22 (3) vs 7 (1)%, respectively; P<0.001]. The threshold ▵Vpeak value of 10% allowed discrimination between R and NR. CONCLUSIONS: In this study, ▵Vpeak was the most appropriate variable to predict fluid responsiveness.

Cross-fostering of the tammar wallaby (Macropus eugenii) pouch young accelerates fore-stomach maturation.

There are two phases of fore-stomach development during the first 200 days of pouch life in tammar wallaby. For the first 170 days, the mucosa displays an immature gastric glandular phenotype that changes to a cardia glandular phenotype, which remains for the rest of the animal's life. During this 200-day period after birth, the pouch young (PY) is dependent on maternal milk, which progressively changes in composition. We showed previously that PY cross-fostered to host mothers at a later stage of lactation accelerated development. In this study, we investigated whether cross-fostering and exposure to late lactation stage milk affected the transition to cardia glandular phenotype. In fostered PY fore-stomach, there was increased apoptosis, but no change in cell proliferation. The parietal cell population was significantly reduced, and expression of gastric glandular phenotype marker genes (ATP4A, GKN2, GHRL and NDRG2) was down-regulated, suggesting down-regulation of gastric phenotype in fostered PY fore-stomach. The expression of cardia glandular phenotype genes (MUC4, KRT20, CSTB, ITLN2 and LPLUNC1) was not changed in fostered PY. These data suggest that fore-stomach maturation proceeds via two temporally distinct processes: down-regulation of gastric glandular phenotype and initiation of cardia glandular phenotype. In fostered PY, these two processes appear uncoupled, as gastric glandular phenotype was down-regulated but cardia glandular phenotype was not initiated. We propose that milk from later stages of lactation and/or herbage consumed by the PY may play independent roles in regulating these two processes.

High outcrossing rates in fields with mixed sorghum landraces: how are landraces maintained?

The effect of mating system on genetic diversity is a major theme in plant evolutionary genetics, because gene flow plays a large role in structuring the genetic variability within and among populations. Understanding crop mating systems and their consequences for gene flow can aid in managing agricultural systems and conserving genetic resources. We evaluated the extent of pollen flow, its links with farming practices and its impact on the dynamics of diversity of sorghum in fields of Duupa farmers in Cameroon. Duupa farmers grow numerous landraces mixed in a field, a practice that favours extensive pollen flow. We estimated parameters of the mating system of five landraces representative of the genetic diversity cultivated in the study site, using a direct method based on progeny array. The multilocus outcrossing rate calculated from all progenies was 18% and ranged from 0 to 73% among progenies. Outcrossing rates varied greatly among landraces, from 5 to 40%. Our results also showed that individual maternal plants were usually pollinated by more than eight pollen donors, except for one landrace (three pollen donors). Although the biological traits of sorghum (inflorescence morphology, floral traits, phenology) and the spatial planting practices of Duupa farmers led to extensive pollen flow among landraces, selection exerted by farmers appears to be a key parameter affecting the fate of new genetic combinations from outcrossing events. Because both natural and human-mediated factors shape evolution in crop populations, understanding evolutionary processes and designing in situ conservation measures requires that biologists and anthropologists work together.

Trend towards increased arterial stiffness or intima-media thickness in ankylosing spondylitis patients without clinically evident cardiovascular disease.

OBJECTIVES: Increased incidence of cardiovascular disease (CVD) has been observed in AS. The reasons of this increase are not fully understood (greater prevalence of traditional cardiovascular risks, consequences of treatment (NSAID) or biological inflammation). The objectives of this study are to assess intima-media thickness (IMT) and arterial stiffness (i.e augmentation index AIx), markers of sub-clinical atherosclerosis in AS patients and to examine the effects of TNF-alpha inhibitors on arterial stiffness in active AS patients. METHODS: Sixty AS patients were enrolled with 60 healthy controls. Their BASDAI (Bath Ankylosing Spondylitis Disease Activity Index) and BASFI (Bath Ankylosing Spondylitis Functional Index) scores, ESR and CRP levels were recorded. Subclinical atherosclerosis was assessed by measurement of AIx by pulse wave analysis and IMT by carotid echography. RESULTS: We found significantly increased IMT in the AS group compared with healthy controls. After adjustment for confounding factors, an underlying trend towards increased IMT was still present (P = 0.06). No difference was found in arterial stiffness between the two groups. AS patients, treated or not with anti-TNF-alpha at baseline, had significantly increased IMT and AIx or a trend towards increase. IMT was positively correlated with tobacco use, WHR and blood pressure but not correlated with CRP level. Despite improvement in markers of disease activity, arterial stiffness was unchanged after 14 weeks of treatment with TNF antagonists. CONCLUSION: This study shows a trend towards increased subclinical atherosclerosis in AS patients. TNF-alpha blockade does not seem to improve arterial stiffness in AS patients, but our results lack statistical power.

Reduced density due to logging and its consequences on mating system and pollen flow in the African mahogany Entandrophragma cylindricum.

In tropical forests, selective logging removes large trees that are often the main contributors to pollination. We studied pollination patterns of the African mahogany, Entandrophragma cylindricum (Sapelli). We investigated two plots in Cameroon corresponding to three tree densities: unlogged forest (Ndama 2002), a mildly logged forest 1 year after logging (Ndama 2003) and a severely logged forest 30 years after logging (Dimako). We used four microsatellite markers to perform paternity analysis. Selfing remained below 2% in all treatments. Pollen flow was mainly long distance but with some proximity effects. Average observed within-plot pollination distances were 338, 266 and 385 m, and pollination by trees outside the plots was 70% (Ndama 2002), 74% (Ndama 2003) and 66% (Dimako). Despite sampling a limited number of seeds from a limited number of mother trees, we obtained seeds sired by 35.6-38.3% of the potential within-plot pollen donors. While trees 20 cm in diameter contributed to pollination, results in Dimako suggest that individual larger trees contribute more to pollination than small ones. This effect was not detected in the other treatments. The results suggest extensive pollen flow in Sapelli. Hence, in Sapelli, the main limiting factor for regeneration after logging may be a reduction in the number of trees capable of producing seeds rather genetic effects due to limits to pollen dispersal.

The endocrine regulation of milk lipid synthesis and secretion in tammar wallaby (Macropus eugenii).

Lipids in tammar milk are predominantly triacylglycerols, and the fatty acid composition varies during the lactation cycle. Little is known about the regulation of their synthesis. This study investigates the endocrine regulation of lipid synthesis in mammary explants from pregnant tammars. Treatment of mammary explants with insulin resulted in a high level of lipid synthesis, but the lipids accumulated in the cytosol. Culture with prolactin resulted in a small increase in lipid synthesis, but electron microscopy showed lipid globules were synthesized in the mammary epithelial cells and secreted into the lumen. Culture with both insulin and prolactin demonstrated elevated levels of synthesis and secretion of lipid. Analysis of the type of fatty acids synthesized in these mammary explants showed that the initiation of synthesis of C(16:0), which also occurs in the first week of lactation, could be reproduced in the pregnant explants cultured with prolactin alone. However, treatment of mammary explants with hydrocortisone did not show a significant effect on lipid synthesis, secretion or the fatty acid synthesized. These results provide new information identifying the role of insulin and prolactin in regulating milk lipid synthesis and secretion in the tammar.

The overexpression of NADPH-producing enzymes counters the oxidative stress evoked by gallium, an iron mimetic.

Gallium (Ga), an iron (Fe) mimetic promoted an oxidative environment and elicited an antioxidative response in Pseudomonas fluorescens. Ga-stressed P. fluorescens was characterized by higher amounts of oxidized lipids and proteins compared to control cells. The oxidative environment provoked by Ga was nullified by increased synthesis of NADPH. The activity and expression glucose 6-phosphate dehydrogenase (G6PDH) and isocitrate dehydrogenase-NADP (ICDH) were stimulated in Ga-cultures. The induction of isoenzymes of these dehydrogenases was also evident in the Ga-stressed cells. Although superoxide dismutase (SOD) activity was significantly enhanced in Ga-stressed cultures, catalase activity experienced a marked diminution. Fe metabolism appeared to be severely impeded by Ga toxicity. This is the first demonstration of the oxidative stress evoked by Ga to be neutralized by a reductive environment generated via the overexpression of NADPH-producing enzymes.

[Implantation of mechanical pulmonary and tricuspid valve prostheses at a distance from complete repair of Tetralogy of Fallot]. / Implantation de deux prothèses mécaniques, pulmonaire et tricuspide, à distance d'une réparation complète de tétralogie de Fallot.

The authors report the case of a 39 years old woman operated for tetralogy of Fallot at the age of 6. Multiple complications due to postoperative atrioventricular block and a poor surgical result on the pulmonary outflow tract led to several reoperations. Right ventricular dysfunction with pulmonary regurgitation and mitral tricuspid valve disease in a context of endocarditis on the pacing catheter led to double pulmonary and tricuspid valve replacement with mechanical prostheses. The outcome at follow-up at 3 years is good. To the authors' knowledge, this is the first reported case of double mechanical valve replacement of the right heart after complete repair of tetralogy of Fallot.