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Biomedical subjects

C André

Publications and source records attributed to C André.

At least 19 recordsLinked to original sources

Immunotherapy with an aluminum hydroxide-adsorbed Juniperus ashei foreign pollen extract in seasonal indigenous cypress pollen rhinoconjunctivitis. A double-blind, placebo-controlled study.

BACKGROUND: The efficacy of standardized Juniperus ashei extract was assessed in patients with allergic rhinoconjunctivitis due to European cypress pollens. METHODS: Forty adults with European cypress-allergic rhinoconjunctivitis were randomized to receive immunotherapy or a matched placebo. Specific immunotherapy was performed with a standardized, aluminum hydroxide-adsorbed J. ashei extract with a potency of 100 IR (arbitrary index of reactivity) containing 54 microg of Jun a 1/ml (Alustal, Stallergenes, France). Subcutaneous injections started in October 2000. The maintenance dose was 0.30 ml of the 100-IR concentration per month. Rhinitis and conjunctivitis symptoms were rated according to a 4-point score. RESULTS: Seventeen patients from the treated group and 15 patients from the placebo group completed year 2001; 14 in each group completed year 2002. A statistically significant improvement (41%, p < 0.02) in the conjunctivitis symptom score was observed in actively treated patients compared to the placebo group at the peak of the 2001 pollen season. Improvement in rhinitis (17%) was not significant. This significant improvement was greater at the peak of the 2002 pollen season (63%, p < 0.01). CONCLUSIONS: This study therefore indirectly validates the concept of treatment by major allergen because J. ashei is absent from the region in which this study was conducted.

Adsorption↗

Prevention of deep venous thrombosis and pulmonary embolism following stroke: a systematic review of published articles.

We performed a systematic review of the literature on venous thromboembolism (VTE) prophylaxis following cerebral infarct (CI) and haemorrhagic stroke. MEDLINE, Cochrane, LILACS and SciELO databases were scanned, and the Abstracts from Brazilian, American and European Neurology and Stroke Congresses were scrutinized for clinical trials. Moreover, the reference lists of articles and reviews were searched. A pooled analysis of two large studies with aspirin was made. Both unfractionated heparin and low molecular weight heparins/heparinoids (LMWH) are partially effective for VTE prophylaxis after CI, and should be routinely used in patients with motor deficit and reduced mobility and no contraindications. Reduction of deep venous thrombosis is better established than the effect over pulmonary embolism or mortality. Some evidence points to a greater efficacy of LMWH. The available evidence does not support the use of mechanical methods or dextran. Aspirin may have a mild protective effect. Low-dose Warfarin might be useful in the rehabilitation setting. Strict recommendations cannot be made in patients with haemorrhagic stroke but intermittent pneumatic compression merits further study. There are important limitations of current VTE preventive strategies following stroke. Additional studies on the combination of methods after CI and of low doses of anticoagulants following cerebral haemorrhage are urgently needed.

Humans↗

Safety and efficacy of Juniperus ashei sublingual-swallow ultra-rush pollen immunotherapy in cypress rhinoconjunctivitis. A double-blind, placebo-controlled study.

BACKGROUND: The safety and efficacy of high-dose sublingual-swallow immunotherapy (SLIT) has been established in pollen rhinoconjunctivitis. This treatment has now been evaluated using an ultra-rush incremental dose regimen with a Juniperus ashei allergen extract in patients allergic to Cupressus sempervirens and Cupressus arizonica. METHODS: Patients received either placebo or SLIT. Evaluation of safety was based on the frequency of adverse events during the incremental dose period (half a day) and during maintenance therapy (4 months). Evaluation of efficacy was based on symptom and medication scores at the pollen peak. RESULTS: Seventy of the 76 patients included completed the study. There were no drop-outs during the rush procedure. One patient in the active group dropped out during the maintenance therapy due to adverse events: gastric pain and vomiting. There was also 1 drop-out in the placebo group due to pregnancy. Adverse events were infrequent, local and mild. Symptom scores for rhinitis and conjunctivitis were not statistically different between groups, but there was a marked and significant (p < 0.03) decrease of the medication score (about 50%) and nasal steroid consumption (about 75%) in the active treatment group. An increase from baseline of serum IgE and IgG4 J. ashei-specific antibodies was only observed in actively treated patients (p < 0.04 and p < 0.01, respectively). CONCLUSIONS: The tolerability and safety of high-dose ultra-rush SLIT were comparable to those reported in previous SLIT studies. SLIT with J. ashei extract, due to its high Jun a 1 content, significantly reduced nasal steroid consumption in patients allergic to European cypress.

Administration, Sublingual↗

Weight reduction for primary prevention of stroke in adults with overweight or obesity.

BACKGROUND: Obesity is seen as a worldwide chronic disease with high prevalence that has been associated with increased morbidity from many conditions including stroke, which is the third leading cause of death in developed countries and a leading cause of severe long-term disability. The causal association between overweight or obesity and stroke is unclear and there is no definite study clarifying the role of obesity treatment in the prevention of a first stroke (primary prevention). Given the prevalence of stroke and the enormous health and economic cost of the disease, it is important to establish the possible impact of weight reduction per se on stroke incidence. OBJECTIVES: To assess the effects of weight reduction in people with overweight or obesity on stroke incidence. SEARCH STRATEGY: MEDLINE, EMBASE, The Cochrane Library, LILACS, databases of ongoing trials and reference lists were used to identify relevant trials. The last search was conducted in April 2006. SELECTION CRITERIA: Randomised controlled trials comparing any intervention for weight reduction (single or combined) with placebo or no intervention in overweight or obese people. DATA COLLECTION AND ANALYSIS: No trials were found in the literature for inclusion in this review. MAIN RESULTS: There are currently no results to be reported. AUTHORS' CONCLUSIONS: Obesity seems to be associated with an increased risk of stroke and it has been suggested that weight loss may lead to a reduction of stroke occurrence. However, this hypothesis is not based on strong scientific evidence resulting from randomised controlled clinical trials. This systematic review identified the urgent need for well-designed, adequately-powered, multi centre randomised controlled trials assessing the effects of weight reduction in persons with overweight or obesity on stroke occurrence.

Adult↗

Rimonabant for overweight or obesity.

BACKGROUND: Worldwide, the prevalence of obesity and overweight in industrialized countries and in a substantial number of developing countries is increasing at an alarming rate. Rimonabant is a selective cannabinoid-1 receptor antagonist that has been investigated for its efficacy in reducing body weight and associated risk factors in obese people. Phase III trials are now under way to test the use of rimonabant for long-term weight-loss. Given the prevalence of overweight and obesity, it is important to establish the efficacy and safety of rimonabant. OBJECTIVES: To assess the effects of rimonabant in overweight and obese people. SEARCH STRATEGY: MEDLINE, EMBASE, The Cochrane Library, LILACS, databases of ongoing trials and reference lists were used to identify relevant trials. The last search was conducted in June 2006. SELECTION CRITERIA: Randomised controlled trials comparing rimonabant with placebo or other weight loss interventions in overweight or obese adults. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed all potentially relevant citations for inclusion and methodological quality. The primary outcome measures were weight loss change, morbidity and adverse effects occurrence. MAIN RESULTS: Four studies evaluating rimonabant 20 mg versus rimonabant 5 mg versus placebo in addition to a hypocaloric diet lasting at least one year were included. Compared with placebo, rimonabant 20 mg produced a 4.9 kg greater reduction in body weight in trials with one-year results. Improvements in waist circumference, high-density lipoprotein cholesterol, triglyceride levels and systolic and diastolic blood pressure were also seen. However, the results with rimonabant 5 mg demonstrated a weight reduction which was only 1.3 kg greater when compared with placebo. No clinically relevant effects on plasma lipids and blood pressure were found. Rimonabant 20 mg caused significant more adverse effects both of general and serious nature, especially of nervous system, psychiatric or gastro-intestinal origin. Attrition rates were approximately 40% at the end of one year. AUTHORS' CONCLUSIONS: The use of rimonabant after one year produces modest weight loss of approximately 5%. Even modest amounts of weight loss may be potentially beneficial. The observed results should be interpreted with some caution, though, since the evaluated studies presented some deficiencies in methodological quality. Studies with longer follow-ups after the end of treatment and of more rigorous quality should be done before definitive recommendations can be made regarding the role of this new medication in the management of overweight or obese patients.

Adult↗

Implication of site quality on mitochondrial electron transport activity and its interaction with temperature in feral Mya arenaria clams from the Saguenay Fjord.

The advent of global warming has given rise to questions about the impact of temperature/pollution interactions on the integrity of certain benthic organisms like bivalves. This interaction was examined in intertidal Mya arenaria clams from the Saguenay Fjord using the concepts of cellular energy allocation and temperature-dependent mitochondrial electron transport (METT) activity. Clams were collected at low tide from six sites (two clean, four polluted) for determinations of condition factor (weight/shell length), growth index (age-to-length ratio), gonadal lipids and maturation index, gonad MET at various habitat temperatures, METT, gill xanthine oxidase and gill DNA damage. Condition factor was generally lower at the four polluted sites, with growth index being severely affected at two of them. Gonadal maturation was also significantly dampened at two of the four pollution-impacted sites. Gill xanthine oxidase (purine bases salvage pathway) and DNA strand breaks were significantly increased at most of the polluted sites, confirming pollution-mediated damage in clams. Moreover, MET at 20 degrees C, METT and gonad lipids were significantly induced at the polluted sites. Clam condition factor was negatively correlated with most of the biomarkers for cellular energy allocation (gonadal lipids, MET and METT), but not with gonadal maturation. DNA damage and xanthine oxidase were positively correlated with MET at 20 degrees C and METT. This is the first report of electron transport in mitochondria being more sensitive to incremental temperature increases in clams under pollution stress. The gradual warming of clam habitats would likely worsen the impacts of pollution in feral clam populations.

Animals↗

Effects of pharmaceutical products and municipal wastewaters on temperature-dependent mitochondrial electron transport activity in Elliptio complanata mussels.

The advent of global warming has given rise to the issue on how temperature impacts the susceptibility of ectothermic organisms to pollution. The purpose of this study was to examine the effects of pharmaceutical products and domestic wastewaters on temperature-dependent mitochondrial electron transport activity in the freshwater mussel Elliptio complanata. Mitochondria from mussels were freshly prepared and exposed to increasing concentrations of various pharmaceutical products known to be found in municipal effluents for 30 min at 4, 12 and 20 degrees C. Electron transport activity as well as lipid peroxidation and DNA strand breaks were determined in the mitochondria. Next, mussels were placed in the aeration lagoons of two municipal wastewater treatment plants for 30 days. Mitochondrial electron transport (MET), temperature-dependent MET (MET(T)) and lipid peroxidation in gonad were then determined. The results show that all products were able to increase MET activity, but at two different ranges of threshold concentration. Certain pharmaceutical products (i.e., ibuprofen, cotinine, fluoxetine, coprostanol and trimethoprim) increased MET(T) at a lower threshold concentration than observed at 20 degrees C. Products of lesser potency in reducing lipid peroxidation were those that produced more DNA strand breaks in mitochondria. Both MET and MET(T) were significantly increased in mussels exposed to aeration lagoon effluents. Lipid peroxidation was also increased in the gonad and was significantly correlated with MET and MET(T) activities. The data indicate that pharmaceutical products and municipal effluents increase respiration rates in isolated mitochondria, such that interaction with temperature could enhance the susceptibility of mitochondrial energy production and oxidative stress in environments contaminated by domestic wastewater.

Bivalvia↗

Occurrence and persistence of Bacillus thuringiensis (Bt) and transgenic Bt corn cry1Ab gene from an aquatic environment.

Genetically modified corn crops and suspensions of Bacillus thuringiensis (Bt) are currently used to control pest infestations of insects of the Lepidoptera family. For this purpose, the cry1Ab gene coding for protein delta-endotoxin derived from B. thuringiensis kurstaki (Btk), which is highly toxic to these insects, was inserted and expressed in corn. The aims of this study were to examine the occurrence and persistence of the cry1Ab gene from Btk and Bt corn in aquatic environments near fields where Bt corn was cultivated. First, an optimal DNA preparation and extraction methodology was developed to allow for quantitative gene analysis by real-time polymerase chain reaction (qPCR) in various environmental matrices. Second, surface water and sediment were spiked in vitro with genomic DNA from Bt or Bt corn to evaluate the persistence of cry1Ab genes. Third, soil, sediment, and water samples were collected before seeding, 2 weeks after pollen release, and after corn harvesting and mechanical root remixing in soils to assess cry1Ab gene content. DNA was extracted with sufficient purity (i.e., low absorbance at 230 nm and absence of PCR-inhibiting substances) from soil, sediment, and surface water. The cry1Ab gene persisted for more than 21 and 40 days in surface water and sediment, respectively. The removal of bacteria by filtration of surface water samples did not significantly increase the half-life of the transgene, but the levels were fivefold more abundant than those in unfiltered water at the end of the exposure period. In sediments, the cry1Ab gene from Bt corn was still detected after 40 days in clay- and sand-rich sediments. Field surveys revealed that the cry1Ab gene from transgenic corn and from naturally occurring Bt was more abundant in the sediment than in the surface water. The cry1Ab transgene was detected as far away as the Richelieu and St. Lawrence rivers (82 km downstream from the corn cultivation plot), suggesting that there were multiple sources of this gene and/or that it undergoes transport by the water column. Sediment-associated cry1Ab gene from Bt corn tended to decrease with distance from the Bt cornfield. Sediment concentrations of the cry1Ab gene were significantly correlated with those of the cry1Ab gene in surface water (R=0.83;P=0.04). The data indicate that DNA from Bt corn and Bt were persistent in aquatic environments and were detected in rivers draining farming areas.

Bacillus thuringiensis↗

A stepwise stoichiometric representation to confirm the dependence of pesticide/humic acid interactions on salt concentration and to test the performance of a silica bonded humic acid column.

In a previous paper (André et al., in press), a novel chromatographic column was developed in our laboratory for studying the binding of pesticides with humic acid (HA), the main organic component in soil. It was demonstrated that this column supported a low fraction of organic modifier in the aqueous mobile phase (<0.25 (v/v)). To overcome this limitation for a practical use, a column in which the stationary phase was based on silica gel with chemically bonded humic acid was created. It was shown that this novel HA column supported a higher methanol fraction (<0.55 (v/v)). As well, the dependence of pesticide/humic acid interactions on salt (sodium chloride) concentration has been expressed in terms of a stepwise stoichiometric representation, which leads to a specific equation for the partition of the added salt between the pesticide molecule, the HA, and the pesticide/HA complex. Based on this novel equation, the dependence of the pesticide/humic acid association on the salt concentration can be formulated via a relation similar to the one of Tanford. In addition, for the first time, the calculation of the affinity energy distribution for different values of the salt concentration in the mobile phase confirmed the existence of several types of binding sites on the HA macromolecule.

Chromatography, High Pressure Liquid↗

Sensitivity of transcranial Doppler for confirming brain death: a prospective study of 270 cases.

OBJECTIVE: The reported sensitivity of transcranial Doppler ultrasonography (TCD) for confirming brain death (BD) ranges from 91% to 100%. We assessed the frequency and causes of false-negative results in TCD examination in a series of patients with BD and in the literature. METHODS: We carried out a prospective TCD examination of consecutive patients with the clinical diagnosis of BD. RESULTS: In 204 (75.5%) of 270 patients, TCD showed a pattern compatible with BD. The causes of the false-negative results were persistent flow in the intracranial arteries in 47 (17.4%) patients and a lack of signal in 19 (7%). Absence of sympathomimetic drug use [odds ratio (OR) 5.4, 95% confidence interval (CI) 1.8-16.0, P = 0.003) and female gender (OR 3.7, 95% CI 1.1-12.5, P = 0.03) were associated with false-negative results. A review of 16 studies showed a sensitivity of 88% and a specificity of 98% of TCD for confirming BD. CONCLUSIONS: The sensitivity of TCD for confirming BD may be lower than previously reported, but is probably similar to that of other non-invasive methods. The specificity of TCD is close to 100%. Uniform criteria are needed for the routine use of TCD as a confirmatory test for BD.

Adult↗

Construction and evaluation of a humic acid column: implication for pesticide risk assessment.

In this paper, humic acid (HA), known to play a large role in the binding and transport of pesticides in soil, was immobilized on a chromatographic support. Then, the association of some herbicides and rodenticides with the main soil component HA was examined using this novel chromatographic column. It appeared that HA has a lower affinity for neutral than for charged pesticides. Moreover, the influence of various parameters was investigated on the pesticide retention in order to providevaluable information about both the binding mechanism and the utilization conditions of the HA column. For all the pesticides studied, a change was clearly vizualized in the HA-pesticide association mechanism at a critical value of the Na+ concentration in the bulk solvent, x(c), equal to 0.6 M. Around this value, the HA structure balanced between a flexible linear conformation for x < x(c) and a random coil form for x > x(c). This work confirmed the conformation change on HA immobilized on silica. As well, only for the charged pesticides, it was clearly pointed out that below a Na+ concentration equal to 0.3 M, the pesticide binding to HA decreased when the salt concentration was enhanced due to an ion pair formation and a competition effect between the sodium cation and pesticide to bind to the HA molecule. Furthermore, it was established that the HA column was stable during an extended period of time, indicating that the HA column could soon become very attractive to determine the risk assessment of pesticides.

Herbicides↗

Chromosomal assignment of the canine melanophilin gene (MLPH): a candidate gene for coat color dilution in Pinschers.

Pinschers affected by coat color dilution show a specific pigmentation phenotype. The dilute pigmentation phenotype leads to a silver-blue appearance of the eumelanin-containing fur and a pale sandy color of pheomelanin-containing fur. In Pinscher breeding, dilute black-and-tan dogs are called "blue," and dilute red or brown animals are termed "fawn" or "Isabella fawn." Coat color dilution in Pinschers is sometimes accompanied by hair loss and a recurrent infection of the hair follicles. In human and mice, several well-characterized genes are responsible for similar pigment variations. To investigate the genetic cause of the coat color dilution in Pinschers, we isolated BAC clones containing the canine ortholog of the known murine color dilution gene Mlph. RH mapping of the canine MLPH gene was performed using an STS marker derived from BAC sequences. Additionally, one MLPH BAC clone was used as probe for FISH mapping, and the canine MLPH gene was assigned to CFA25q24.

Animals↗

Occurrence of pharmaceutical products in a municipal effluent and toxicity to rainbow trout (Oncorhynchus mykiss) hepatocytes.

Pharmaceutical and personal care products (PPCPs) are found in municipal effluents and represent the major sources of contamination for the aquatic environment. A preliminary chemical analysis of wastewater identified several compounds associated with PPCPs, including caffeine, ibuprofen, naproxen, oxytetracycline, novobiocin, carbamazepine, gemfibrozil, bezafibrate, trimethoprim, sulfamethoxazole, and sulfapyridine. The purpose of this study was to examine the cytotoxic and oxidative effects of these products and other wastewater-related products (i.e., coprostanol, cotinine, estradiol-17beta, nonylphenol, and cholesterol) in primary cultures of rainbow trout hepatocytes. The redox activity of various PPCPs in trout (Oncorhynchus mykiss) liver microsomes was investigated in vitro by tracking the rate of oxidation of reduced nicotinamide adenine dinucleotide phosphate (NADPH) and the formation of lipid peroxidation (LPO) after a 60-min incubation period. In addition, primary cultures of rainbow trout hepatocytes were exposed to various drugs identified in the municipal effluent for 48 h at 15 degrees C. Our results show that most PPCPs (83%) accelerated the rate of NADPH oxidation in the presence of microsomes and 72% of them increased LPO in microsomal membranes. LPO levels were significantly correlated (R = 0.5; P<0.05) with the number of functional groups on the molecule's backbone (i.e., number of O, S, N, P/number of C and H) and negatively so (R = -0.44; P<0.05) with the octanol/water partition coefficient, suggesting that nucleophilicity and hydrophobicity are related to oxidative activity for these compounds. Exposure of trout hepatocytes to these products leads in many cases to decreased cell viability, increased CYP3A-related monooxygenase activity (benzylether resorufin dealkylase), and LPO. No induction of CYP1A1-related activity (7-ethoxyresorufin O-deethylase) was observed. Moreover, municipal effluent extracts (ethanol) were able to increase all the above responses in a dose-dependent manner. These results suggest that the basic redox properties of PPCPs could influence oxidative metabolism in liver cells and lead to oxidative damage. These products have the potential to produce a toxic response in aquatic organisms and the above biomarkers were shown to respond readily to PPCPs in aquatic organisms.

Animals↗

Comparative sequence analysis and radiation hybrid mapping of the canine keratin 10 gene.

The type I keratin, K10, is expressed in epidermal keratinocytes undergoing terminal differentiation to form the stratum corneum, a barrier essential for life. In order to facilitate the study of keratinization disorders in the dog, the sequence and mapping of KRT10 is reported. The coding region of KRT10 is 1707 bp and is comprised of eight exons. Although the length of KRT10 has been reported to be polymorphic in humans, this was not observed in the eight domestic dog breeds studied, although one wild canid displayed a size difference. The structure and sequence of this gene is highly conserved across mammalian species. Canine K10 had an 86% amino acid identity with the human gene. KRT10 was localized to the on-going canine radiation hybrid map to chromosome 9 in the type I keratin gene cluster.

Amino Acid Sequence↗