A Simple Scale for Screening Lower-Extremity Arterial Disease as a Possible Cause of Low Back Pain: a Cross-sectional Study Among 542 Subjects.

BACKGROUND: Epidemiological, imaging, and anatomical studies suggest an association between proximal arterial atherosclerosis and development of low back pain (LBP). OBJECTIVES: We aimed to define (1) the frequency and (2) factors associated with exercise-induced proximal ischemia (EIPI) in individuals with LBP and (3) develop a clinical screening scale. DESIGN: Monocentric cross-sectional study. PARTICIPANTS: All patients with history of ongoing LBP referred to our exercise investigation laboratory for exercise transcutaneous oximetry (ex-tcPO2) between January 2011 and December 2017 (n = 542; mean age, 65.4 ± 10.9; 83.9% men). MAIN MEASURES: EIPI was defined as a decrease from rest of oxygen pressure (DROP) below - 15 mmHg on the lumbar and/or buttock probes. Ex-tcPO2 is a reliable validated tool for diagnosing EIPI in comparison with arteriography and computed tomography angiography. Ex-tcPO2 was performed on a treadmill until symptom manifestation or exhaustion. Clinical data were collected using interview questionnaires, medical file review, and clinical examination. KEY RESULTS: EIPI was diagnosed in 282 patients (52%). Age ≤ 70 years (OR, 2.22; 95% CI, 1.35-3.57; p = 0.002), a history of proximal revascularization (OR, 2.64; 95% CI, 1.50-4.65; p = 0.001), use of antiplatelet medication (OR, 1.71; 95% CI, 0.96-3.06; p = 0.069), a relationship between exercise and LBP (OR, 2.61; 95% CI, 1.49-4.57; p = 0.001), and an abnormal ankle to brachial index (OR, 2.87; 95% CI, 1.77-4.66; p < 0.0001) were identified as EIPI predictors. Using these items, we developed a screening scale that showed an area under the receiver operating characteristics curve of .756. At a score of ≥ 3, the sensitivity, specificity, and accuracy for EIPI were 84%, 55%, and 71%, respectively. CONCLUSIONS: EIPI was common among our patients with LBP undergoing ex-TcPO2. Our screening scale could help better select the patients who require angiography.

Post-exercise ankle blood pressure and ankle to brachial index after heavy load bicycle exercise.

The American Heart Association (AHA) recommendations for diagnosing peripheral artery disease (PAD) after exercise are a decrease >20% of ankle brachial index (ABI) or >30 mm Hg of ankle systolic blood pressure (ASBP) from resting values. We evaluated ABI and ASBP values during incremental maximal exercise in physically active and asymptomatic patients. Patients (n = 726) underwent incremental bicycle tests with pre- and post-exercise recording of all four limbs arterial pressures simultaneously. Univariate and multivariate analyses were performed to define the correlation between post-exercise ABI with various clinical factors, including age. Thereafter, the population was divided into groups of age: less than 40 (G < 40), from 40 to 44 (G40/44) from 45 to 49 (G45/49), from 50 to 54 (G50/54), from 55 to 59 (G55/59), from 60 to 64 (G60/64), and 65 and above (G ≥ 65) years. Results are mean ± SD. * is two-tailed P < .05 for ANOVA with Dunnett's post-hoc test from G40. Changes from rest in ASBP were -3 ± 22 (G < 40), -2 ± 20 (G40/44), 4 ± 22* (G45/49), 10 ± 25* (G50/54), 18 ± 21* (G55/59), 23 ± 27* (G60/64), and 16 ± 22* (G ≥ 65) mm Hg. Decreases from rest in ABI were 32 ± 9 (G < 40), 33 ± 9 (G40/44), 29 ± 8 (G45/49), 27 ± 10* (G50/54), 24 ± 7* (G55/59), 22 ± 12* (G60/64), and 21 ± 12* (G ≥ 65) % of resting ABI. Maximal incremental exercise results in ABI and ASBP changes are mostly dependent on age. The AHA limits for post-exercise ABI are inadequate following maximal incremental bicycle testing. Future studies detecting PAD in active patients should account for the effect of age.

An investigation of the immunotoxicity of oil sands processed water and leachates in trout leukocytes.

Increased oil sands (OS) mining activity has raised concerns about impacts on aquatic organisms. This study sought to examine the effects of single representative compounds from OS (benzo(a)pyrene, naphthalene), a mixture of naphthenic acids (NAs), OS-processed water (OSPW) and OS leachate (OSL) extracts on rainbow trout leukocytes. Primary cultures of trout leukocytes were exposed to increasing concentrations of benzo(a)pyrene, naphthalene, NAs, OSPW and OSL for 48h at 18°C. Immunocompetence was followed by measuring changes in lymphocyte and macrophage viability and phagocytosis. Changes in the expression of 10 transcripts were also followed: interleukin 1, 2 and 6 (Il-1, Il-2 and Il-6), calreticulin (CRT), caspase 9 (Cas9), aryl hydrocarbon receptor (AhR), cyclooxygenase-2 (COX2), glutathione S-transferase (GST), catalase (CAT) and p53 tumor suppressor. The results revealed that exposure to OSPW extracts decreased the capacity of macrophages to engulf three beads or more, while the other compounds generally increased phagocytosis activity. Lymphocyte apoptosis was increased by all compounds and mixtures except naphthalene. Both OSPW and OSL induced apoptosis in macrophages. At the gene expression level, Cas9, CRT, Il-1 (inhibition) and Il-2 were specifically influenced by OSPW, while CAT, p53, COX2 and Il-1 (induction) transcripts were specifically expressed by OSL. Leukocyte exposure to OSPW produced characteristic changes in immunocompetence and genes involved in proinflammatory, apoptosis and protein damage (CRT) pathways which could not be explained by OSL, benzo(a)pyrene, naphthalene and NA mixture.

The majestic canopy-emergent genus Dinizia (Leguminosae: Caesalpinioideae), including a new species endemic to the Brazilian state of Espírito Santo.

Since its description, almost 100 years ago, the genus Dinizia has been treated as monospecific, comprising the single canopy-emergent species Dinizia excelsa Ducke which grows in non-flooded Amazonian forests of Guyana, Suriname and seven states of northern and central-western Brazil. Dinizia jueirana-facao G. P. Lewis & G. S. Siqueira, which grows in a restricted area of semi-deciduous Atlantic rain forest in Espírito Santo state, Brazil, is described as a new species in the genus. The new species is also a canopy-emergent of impressive stature. We provide descriptions for both species, a key to species identification, a distribution map and the new species is illustrated. Fossil leaves, inflorescences and fruit provide evidence for a Dinizia-like ancestor occurring in south-eastern North America during the Eocene. In contrast to D. excelsa where pollen is dispersed in tetrads, the pollen of D. jueirana-facao is shed in monads. D. jueirana-facao is considered critically endangered following IUCN conservation criteria, whereas D. excelsa is assessed to be of least concern. A lectotype is designated for D. excelsa.

Fate of silver nanoparticles in wastewater and immunotoxic effects on rainbow trout.

Silver nanoparticles (AgNPs) are currently used in technology, medicine and consumer products, even though the fate and the ecotoxicological risks on aquatic organisms of these new materials are not well known. The purpose of this study was to investigate the fate, bioavailability of AgNPs and their effects on fish in presence of municipal effluents. Juvenile rainbow trout were exposed for 96h to 40µg/L of AgNPs or 4µg/L of dissolved silver (AgNO3) in diluted (10%) municipal wastewater. Silver (Ag) concentrations were measured both on water samples and fish tissues (liver and gills). Toxicity was investigated by following immunological parameters in the pronephros (viability, phagocytosis) and biomarkers in liver and gills (cyclooxygenase activity, lipid peroxidation, glutathione-S-transferase, metallothioneins, DNA strand breaks and labile zinc). Results indicated that AgNPs appeared as small non-charged aggregates in wastewaters (11.7±1.4nm). In gills, the exposure to AgNPs induced morphological modifications without visible nanoparticle bioaccumulation. Dissolved Ag(+) was bioavailable in diluted effluent and induced oxidative stress (lipid peroxidation), labile zinc and a marginal decrease in superoxide dismutase in fish gills. Ag(+) also increased significantly metallothionein levels and inhibited the DNA repair activity in the liver. Finally, the two silver forms were found in liver and induced immunosuppression and inflammation (increase in cyclooxygenase activity). This study demonstrated that both forms of Ag produced harmful effects and AgNPs in wastewater were bioavailable to fish despite of their formation of aggregates.

Intestinal microbiota contributes to individual susceptibility to alcoholic liver disease.

OBJECTIVE: There is substantial inter-individual diversity in the susceptibility of alcoholics to liver injury. Alterations of intestinal microbiota (IM) have been reported in alcoholic liver disease (ALD), but the extent to which they are merely a consequence or a cause is unknown. We aimed to demonstrate that a specific dysbiosis contributes to the development of alcoholic hepatitis (AH). DESIGN: We humanised germ-free and conventional mice using human IM transplant from alcoholic patients with or without AH. The consequences on alcohol-fed recipient mice were studied. RESULTS: A specific dysbiosis was associated with ALD severity in patients. Mice harbouring the IM from a patient with severe AH (sAH) developed more severe liver inflammation with an increased number of liver T lymphocyte subsets and Natural Killer T (NKT) lymphocytes, higher liver necrosis, greater intestinal permeability and higher translocation of bacteria than mice harbouring the IM from an alcoholic patient without AH (noAH). Similarly, CD45+ lymphocyte subsets were increased in visceral adipose tissue, and CD4(+)T and NKT lymphocytes in mesenteric lymph nodes. The IM associated with sAH and noAH could be distinguished by differences in bacterial abundance and composition. Key deleterious species were associated with sAH while the Faecalibacterium genus was associated with noAH. Ursodeoxycholic acid was more abundant in faeces from noAH mice. Additionally, in conventional mice humanised with the IM from an sAH patient, a second subsequent transfer of IM from an noAH patient improved alcohol-induced liver lesions. CONCLUSIONS: Individual susceptibility to ALD is substantially driven by IM. It may, therefore, be possible to prevent and manage ALD by IM manipulation.

Genotoxic potential of several naphthenic acids and a synthetic oil sands process-affected water in rainbow trout (Oncorhynchus mykiss).

The exploitation of oil sands has raised major environmental concerns, particularly regarding the presence of high concentration in contaminants such as polycyclic aromatic hydrocarbons (PAHs) and naphthenic acids (NAs) in oil sands process-affected water (OSPW). The purpose of this study was, first to evaluate the genotoxic impact of OSPW-related compounds such as NAs and PAHs in a salmonid species and secondly to assess if OSPW exposure leads to genotoxicity. For this purpose, rainbow trout hepatocytes were exposed in vitro to environmentally relevant concentrations of synthetic NAs, naphtalene, benzo(a)pyrene, and extracts of synthetic OSPW (generated by a laboratory bitumen extraction) and of oil sands leaching water (OSLW, mimicking leaching of oil sands in river water). Primary DNA damage was assessed by the formamidopyrimidine-DNA glycolyase (Fpg)-modified comet assay. Genotoxicity was observed in hepatocytes exposed to several NAs, mixture of them, OSPW and OSLW extracts. The chemical structure of NAs influences the genotoxicity potential: among the NAs tested, the most cyclic NA was the most genotoxic. It also appears that genotoxicity was more marked for OSPW than for OSLW. Because exposure to OSPW led to oxidative DNA damage, while after exposure to several NAs, these types of DNA damage were limited, the NAs tested in this study could not be qualified as the only major contaminants responsible for OSPW genotoxicity. Notwithstanding, it should be noteworthy that exposure to NAs resulted in genotoxic impact at concentrations lower than those documented by literature for fresh OSPW. Further research is needed to explore the relationships between the chemical structure of NAs and their genotoxicity in the light of the distribution of NAs in fresh OSPW samples as well as in surface waters.

Bioavailability and immunotoxicity of silver nanoparticles to the freshwater mussel Elliptio complanata.

The purpose of this study was to examine the effects of Ag nanoparticles (nAg) of two different sizes (20 and 80 nm) and Ag(+) on the immune system of the freshwater mussel Elliptio complanata. Mussels were exposed to increasing concentrations of nAg and dissolved Ag (AgNO3) for 48 h at 15°C and concentration of 0, 0.8, 4, or 20 µg/L. Immunocompetence was determined by hemocyte viability, phagocytosis, and cell cytotoxicity. Ag tissue loadings and levels of metallothioneins (MT), lipid peroxidation (LPO), and labile zinc (Zn) were also determined. Results revealed first that 20- and 80-nm nAg readily formed aggregates in freshwater. Ag was detected in soft tissues with each form of Ag with bioconcentration factors of 20, 9, and 7 for Ag(+), 20-nm nAg, and 80-nm nAg, respectively. Significant induction in phagocytosis and decreased cell cytotoxicity were observed. All forms of Ag were able to induce LPO in gills and digestive glands at concentrations below those from the initial fraction of dissolved Ag. The effects of nAg on MT levels in mussels were not discernible from those of dissolved Ag, but the 80-nm was 25-fold more potent than 20-nm nAg in inducing MT. Multivariate analysis revealed that the global responses of the 20- and 80-nm nAg were generally similar to those of dissolved Ag. Data also demonstrated that nAg are bioavailable for mussels where the immune system is a target during early exposure to nanoparticles.

Size distribution effects of cadmium tellurium quantum dots (CdS/CdTe) immunotoxicity on aquatic organisms.

The increasing use of products derived from nanotechnology has raised concern about their potential toxicity to aquatic life. This study sought to examine the comparative immunotoxicity of capped cadmium sulphide/cadmium telluride (CdS/CdTe) quantum dots (QDs) and possible impact of particle/aggregate size on two bivalves (Mytilus edulis and Elliptio complanata) and a fish (Oncorhynchus mykiss). The QDs were dispersed in sterile water and fractionated using a series of micro/ultrafiltration membranes of decreasing pore size: 450 nm, 100 nm, 50 nm, 25 nm, 100 kDa (6.8 nm), 30 kDa (4.6 nm), 10 kDa (3.2 nm) and 1 kDa (1.5 nm). The total concentrations of cadmium and tellurium were determined for the filtered material and for that retained on the filters (retentate). The immunotoxicity was determined by measuring cell viability and phagocytosis. Results revealed that nanoparticles retained on the ultrafilters had a higher Cd/Te ratio compared to the permeate fraction (ratio of 5 and 2 respectively) which could indicate that the CdS core was not associated with the permeable fraction of Cd. Our results demonstrate that the toxicity of CdS/CdTe QDs was concentration and size dependent. Large CdS/CdTe QD aggregates (25 nm < size < 100 nm) reduced phagocytosis more than did smaller nanoparticles (<25 nm). Moreover, our results revealed that the different species responded differently to these fractions. Mytilus edulis hemocytes were less sensitive to CdS/CdTe QDs than the Oncorhynchus mykiss macrophage and Elliptio complanata hemocytes.

Cutaneous microvascular functional assessment during exercise: a novel approach using laser speckle contrast imaging.

Cardiovascular diseases are often revealed during exercise and are associated with cutaneous blood flow (CBF) dysfunction. Studies of CBF during exercise are consequently of interest. Laser speckle contrast imaging (LSCI) allows for non-contact and real-time recording of CBF at rest. We tested whether LSCI could allow the study of CBF during a cycling exercise using a specific signal treatment procedure that removes movement-induced artefacts from the LSCI raw signal. We recorded the baseline CBF and peak post-occlusive reactive hyperaemia (PORH) from the cutaneous forearm using LSCI and the mean blood pressure before and during cycling (80 W at 70 rpm) in nine healthy subjects. We determined the cross-correlation coefficient r between LSCI traces obtained before and during cycling and before and after a specifically designed signal processing technique. The results are presented as the median (25th-75th centile) and expressed as the cutaneous vascular conductance (laser speckle perfusion units (LSPU) per millimetre of mercury). Cross-correlation r increased from 0.226 ± 0.140 before to 0.683 ± 0.170 after post-processing. After signal processing, the peak PORH during exercise was reduced [0.38 (0.30-0.52) LSPU/mmHg] compared with the peak PORH during the non-exercise phase [0.69 (0.63-0.74) LSPU/mmHg, p < 0.01], whereas no difference was found between the baseline values. With adequate signal processing, LSCI appears valuable for investigating CBF during exercise. During constant-load lower limb cycling exercise, the upper limb peak PORH is reduced compared with the peak PORH during non-exercise. The underlying mechanisms warrant further investigations in both healthy (trained) subjects and diseased (e.g., coronary heart disease) patients.

Social functioning and self-esteem in young people with disabilities participating in adapted competitive sport.

AIMS: The aim of this study was to investigate social functioning quality of life and self-esteem in young people with disabilities taking part in adapted competitive sport. METHOD: A sample of 496 athletes (mean age 16 years 4 months, range: 9 years to 20 years 9 months) was obtained from the 540 participants (91.8%) involved in a French national championship. The main outcome measurements were a social functioning inventory (PedsQL 4.0 social functioning) and a self-esteem inventory in physical areas (physical self inventory 6 PSI-6). RESULTS: The mean PedsQL SF score was 74.6 (SD: 17.7). Comparisons of PedsQL SF according to gender, age, self mobility and training revealed no significant differences between the groups. PedsQL SF was weakly but significantly correlated with all subscales of the PSI-6 in the total population. PSI-6 scores were significantly different between boys and girls, with better self-esteem for boys on general self-esteem (7.7 vs. 6.9, P=0.018), physical condition (6.8 vs. 6.0, P=0.023) and attractive body subscores (6.5 vs. 5.1, P<0.001). CONCLUSION: Social functioning scores were significantly higher in this population than in the samples of young people with disabilities available in the literature. Interactions between self-concept, social functioning quality of life and participation in adapted sport activities require further studies.

Effect of intestinal microfloras from vegetarians and meat eaters on the genotoxicity of 2-amino-3-methylimidazo[4,5-f]quinoline, a carcinogenic heterocyclic amine.

Aim of this study was to investigate the impact of intestinal microfloras from vegetarians and non-vegetarians on the DNA-damaging activity of 2-amino-3-methyl-3H-imidazo[4,5-f]quinoline (IQ), a carcinogenic heterocyclic amine that is found in fried meats. Floras from four vegetarians (Seventh Day Adventists) and from four individuals who consumed high amounts of meats were collected and inoculated into germfree F344 rats. The rats were kept on isocaloric diets that either contained animal derived protein and fat (meat consumers group) or proteins and fat of plant origin (vegetarian groups). IQ (90 mg/kg bw) was administered orally, after 4 h the extent of DNA-damage in colon and liver cells was determined in single cell gel electrophoresis assays. In all groups, the IQ induced DNA-migration was in the liver substantially higher than in the colon. In animals harbouring floras of vegetarians, the extent of damage was in both organs significantly (69.2% in the liver, P<0.016 and 64.7%, P<0.042 in the colon, respectively) lower than in the meat consumer groups. Our findings show that diet related differences in the microfloras have a strong impact on the genotoxic effects of IQ and suggest that heterocyclic amines are less genotoxic and carcinogenic in individuals that consume mainly plant derived foods.

[Evaluation of a program to promote hepatitis B vaccination among adolescents in a school environment of Central Montreal]. / Evaluation d'une campagne de promotion de la vaccination contre l'hépatite B chez les adolescents de la région de Montréal-Centre en milieu scolaire.

OBJECTIVE: We developed a hepatitis B vaccination promotion project aimed at Montreal-area adolescents. A student leaflet, teacher's guide and classroom poster were developed. Our objectives were to have 25% of teachers give a course on hepatitis B and 25% of students begin vaccination against hepatitis B. METHOD: The promotional campaign was aimed at 100,000 students in 225 public and private secondary schools. The evaluation was carried out six months after the beginning of the campaign. Data were collected through self-administered questionnaires to students (n = 206), teachers (n = 128) and school nurses (n = 30). RESULTS: Two thirds of teachers used the material and 45% gave a course on the subject. The teachers who gave the course felt knowledgeable about teaching the subject and felt that the subject was important. Six months after the beginning of the campaign, 38% of secondary students had received at least one dose of vaccine. CONCLUSION: The promotional material was appreciated by both students and teachers and used during secondary school classes. Teachers, when given appropriate tools and supported by school nurses, are highly motivated to pass on preventive heath messages to their students.

Making an omnidirectional reflector.

The effect of having a finite number of layers on the design of omnidirectional reflectors was investigated. It was shown that the structure should be finished with a low-index layer having a thickness larger than a quarter-wave to increase reflectivity, whereas layers below may remain of quarter-wave optical thickness at normal incidence angle. This general trend has been used for designing and realizing two a-Si-SiO(2) (amorphous silicon and silicon dioxide) omnidirectional reflectors in the near-infrared range on a silicon and a silica substrate, respectively. Owing to the decrease of absorption of recrystallized silicon as compared with a-Si in the visible range, the transmissivity of the structure realized on silica substrate was dramatically increased in the visible range upon annealing, whereas the high reflectivity and the omnidirectional effect were maintained in the near-infrared range.

First in vitro cycle of the chicken mite, Dermanyssus gallinae (DeGeer 1778), utilizing an artificial feeding device.

The red poultry mite, Dermanyssus gallinae, is one of the most economically deleterious ecto-parasites of layer hens worldwide. D. gallinae is difficult to eliminate from infested poultry farms, and even to study, because it resides on the host only during the bloodmeal at night, and hides in the crevices of poultry houses during the day. Here, the life-cycle of D. gallinae was reproduced entirely in vitro. Mites were incubated in a glass pipette at 30 degrees C, 60-95 degrees relative humidity and total darkness. A feeding apparatus, composed of a membrane, reservoir and blood was fitted on the pipette during bloodmeals. We tested feeding rates on blood mixed with 1 of 3 anti-coagulants (EDTA, heparin and trisodium citrate) at different concentrations, and biological and artificial membranes. The best engorgement and survival rates for all 3 haematophagous life-stages of the parasite were observed in 1-day-old chick membranes and heparinized (0.02 mmo/ml) blood. We then describe the steps in developing a complete self-sustaining in vitro life-cycle. A colony of mites was maintained in vitro for 7 generations. Losses in the first generation were heavy, but survival had multiplied 5-fold by the fifth generation. We hypothesize that heavy mortality rates during the first life-cycle correspond to selective pressure: only the mites which fed and survived in vitro were able to reproduce.

Plant O-methyltransferases: molecular analysis, common signature and classification.

Comparative analysis of the predicted amino acid sequences of a number of plant O-methyltransferase cDNA clones show that they share some 32-71% sequence identity, and can be grouped according to the different compounds they utilise as substrates. Five highly conserved regions are proposed as a signature for plant O-methyltransferases, two of which (regions I and IV) are believed to be involved in S-adenosyl-L-methionine and metal binding, respectively. The glycine-rich signature regions include a 36 amino acid domain which is located in the mid-terminal section of the carboxy terminus of most O-methyltransferase sequences. Cladistic analysis of the amino acid sequences suggests that plant O-methyltransferases may have arisen from common ancestral genes that were driven by different structural and/or functional requirements, and whose descendants segregated into different biochemical species. A comprehensive classification of plant O-methyltransferases is proposed following the guidelines of the Commission of Plant Gene Nomenclature.