Assessment of Genetic Variability of Fish Personality Traits using Rainbow Trout Isogenic Lines

The study of inter-individual variability of personality in fish is a growing field of interest but the genetic basis of this complex trait is still poorly investigated due to the difficulty in controlling fish genetic origin and life history. When available, isogenic lines that allow performing independent tests on different individuals having identical genotype constitute a very relevant experimental material to disentangle the genetic and environmental components of behavioural individuality. We took advantage of heterozygous isogenic lines to investigate the personality in rainbow trout through the analysis of their reactions to different experimental situations. To this end, seven to ten rainbow trout isogenic lines were screened for their spatial exploratory behaviour, their flight response toward a stressor and their risk taking behaviour. Results showed that some lines seemed less sensitive to new events or environmental changes and could be defined as low responsive, while others were very sensitive and defined as high responsive. The use of isogenic lines highlighted the importance of genetic factors, in combination with life history, in the expression of personality in domesticated fish.     

Regional management of arterial hypertension in France. Report of a survey of general practitioners

A survey was conducted in 14 regional samples of general practitioners (GPs) included in Gallup-up poll. 2,423 GPs contributed to the study and had to include all patients > 18 years old over a period of one week. Patients were considered hypertensives if the mean of two recorded BP measurements was > or = 140/90 mmHg and/or < 140/90 mmHg if they were under antihypertensive treatment. Hypertensives were considered as controlled if there BP levels were overall < 140/90 mmHg under treatment. The risk factors associated with hypertension were collected in order to evaluate the cardiovascular risk, according to 1999 ISH-OMS recommendations. 156,470 patients recruited by 2423 GPs were included in the study representing 14 different French regions: Ile-de-France I (1), Ile-de-France II (2), Ile-de-France-Pays-de-la-Loire (3), Bretagne (4), Normandie-Picardie (5), Nord-Pas-de-Calais (6), Alsace-Lorraine (7), Bourgogne-Franche Comté (8), Rh?nes-Alpes (9), Provence-C?te d'Azur (10), Languedoc-Provence (11), Limousin-Auvergne (12), Midi-Pyrénées (13), Aquitaine (14). Among 70,073 hypertensives, 23,054 had never received antihypertensive treatment, and 32,059 (47%) had a high or a very high cardiovascular risk. 67% of hypertensives (47,019) were treated, and 32.8% of treated hypertensives (15,422) had a BP < 140/90 mmHg. The study illustrated few differences in prevalence and control of hypertension in the different French regions: BP control at the 140/90 mmHg threshold vary from 28.5 to 36.6% among treated hypertensives and % of patients at high cardiovascular risk from 42.1% (South-France) to 49.7% (East-France).     

In vivo MRI tracking of exogenous monocytes/macrophages targeting brain tumors in a rat model of glioma

This study has shown that murine monocytes/macrophages (Mo/Ma) can be labeled simply and efficiently with large, green-fluorescent, micrometer-sized particles of iron-oxide (MPIO). Neither size nor proliferation rate of the Mo/Ma is significantly affected by this labeling. The labeled Mo/Ma have been administered intravenously to rats that had developed a glioma following stereotactic injection of C6 cells. The labeled Mo/Ma were shown to target the brain tumors, a process that could be monitored non-invasively using T2*-weighted MRI. MRI observations were confirmed by Prussian blue staining, lectin staining and fluorescence histology. Overall, the results of this study suggest that the use of Mo/Ma may be envisaged in the clinic for vectorizing therapeutic agents toward gliomas.     

Ancient haplotypes resulting from extensive molecular rearrangements in the wheat A genome have been maintained in species of three different ploidy levels

Plant genomes, in particular grass genomes, evolve very rapidly. The closely related A genomes of diploid, tetraploid, and hexaploid wheat are derived from a common ancestor that lived <3 million years ago and represent a good model to study molecular mechanisms involved in such rapid evolution. We have sequenced and compared physical contigs at the Lr10 locus on chromosome 1AS from diploid (211 kb), tetraploid (187 kb), and hexaploid wheat (154 kb). A maximum of 33% of the sequences were conserved between two species. The sequences from diploid and tetraploid wheat shared all of the genes, including Lr10 and RGA2 and define a first haplotype (H1). The 130-kb intergenic region between Lr10 and RGA2 was conserved in size despite its activity as a hot spot for transposon insertion, which resulted in >70% of sequence divergence. The hexaploid wheat sequence lacks both Lr10 and RGA2 genes and defines a second haplotype, H2, which originated from ancient and extensive rearrangements. These rearrangements included insertions of retroelements and transposons deletions, as well as unequal recombination within elements. Gene disruption in haplotype H2 was caused by a deletion and subsequent large inversion. Gene conservation between H1 haplotypes, as well as conservation of rearrangements at the origin of the H2 haplotype at three different ploidy levels indicate that the two haplotypes are ancient and had a stable gene content during evolution, whereas the intergenic regions evolved rapidly. Polyploidization during wheat evolution had no detectable consequences on the structure and evolution of the two haplotypes.     

Dystrophin-dependent muscle degeneration requires a fully functional contractile machinery to occur in C. elegans

In mammals, the lack of dystrophin leads to a degeneration of skeletal muscles. It has been known for many years that this pathology can be blocked by denervation or immobilization of muscles. It is not yet clear, however, whether this suppressing effect is due to the absence of fiber contraction per se, or to other mechanisms which may be induced by such treatments. We took advantage of the genetic tools available in the animal model Caenorhabditis elegans to address this question. Using RNA interference and existing mutants, we genetically impaired the excitation-contraction cascade at specific points in a dystrophin-deficient C. elegans strain which normally undergoes extensive muscle degeneration. Our data show that reducing sarcomere contraction by slightly impairing the contraction machinery is sufficient to dramatically suppress muscle degeneration. Thus, it is the physical tension exerted on the muscle fibers which is the key deleterious event in the absence of dystrophin.     

Association between inflammatory mediators and response to inhaled nitric oxide in a model of endotoxin-induced lung injury

Introduction  

Inhaled nitric oxide (INO) allows selective pulmonary vasodilation in acute respiratory distress syndrome and improves PaO₂ by redistribution of pulmonary blood flow towards better ventilated parenchyma. One-third of patients are nonresponders to INO, however, and it is difficult to predict who will respond. The aim of the present study was to identify, within a panel of inflammatory mediators released during endotoxin-induced lung injury, specific mediators that are associated with a PaO₂ response to INO.     

Population-based study on occupational risk factors for preeclampsia and gestational hypertension

OBJECTIVES: Preeclampsia is a leading cause of maternal and perinatal morbidity. Work-related factors may influence the occurrence of this disorder. This case-control study estimated the associations between work-related physical and psychosocial factors and the risk of preeclampsia and gestational hypertension. METHODS: The eligible women consisted of a random sample of the women who delivered a singleton live birth in 1997-1999 in six regions of Quebec and worked during pregnancy. Cases of preeclampsia (N=102) and gestational hypertension (N=99) were compared with normotensive controls (N=4381). Information on occupational exposures at the onset of pregnancy was collected during phone interviews a few weeks after delivery. Detailed information was obtained on work schedule, postures, physical exertion, work organization, noise, vibration, and extreme temperature. Adjusted odds ratios (aOR) were estimated through polytomous logistic regression. RESULTS: Women standing daily at least 1 hour consecutively without walking experienced a higher risk of preeclampsia [aOR 2.5, 95% confidence interval (95% CI) 1.4-4.6], as well as women climbing stairs frequently (aOR 2.3, 95% CI 1.2-4.1) and women working more than 5 consecutive days without a day-off (aOR 3.0, 95% CI 1.0-9.5). Squatting or kneeling, pushing or pulling objects, whole-body vibration, forced pace, job strain, and no control on breaks were positively, but nonsignificantly, associated with preeclampsia. The associations were weaker for gestational hypertension. CONCLUSIONS: These findings suggest that being exposed to physically demanding and stressful occupational conditions at the onset of pregnancy increases the risk of preeclampsia.