Biomedical subjects

C Bastien

Publications and source records attributed to C Bastien.

At least 19 recordsLinked to original sources

PubMed2005

Genetic architecture of qualitative and quantitative Melampsora larici-populina leaf rust resistance in hybrid poplar: genetic mapping and QTL detection.

In order to elucidate the genetic control of resistance to Melampsora larici-populina leaf rust in hybrid poplars, a Populus deltoides x P. trichocarpa F(1) progeny was analysed for qualitative and quantitative rust resistances. This progeny was evaluated for three components of quantitative resistance (latent period, uredinia number and uredinia size) to seven M. larici-populina strains in controlled conditions, and for one component of field susceptibility (rust colonization on the most infected leaf). One qualitative resistance locus inherited from P. deltoides, R(1), was localized on the genetic map. It segregates 1 : 1 in the F(1) progeny and is effective against four of the studied strains. QTL analysis was performed separately on R(1) and r(1) genotype subsets. An additional detection was conducted on the entire F(1) progeny for the three strains able to overcome R(1) and for MAX2. A total of nine QTLs were detected. Two had large, broad-spectrum effects. One (R(US)) is inherited from the P. trichocarpa parent; the other is inherited from P. deltoides and colocalized with R(1). Seven QTLs had only limited and specific effects. Significant interaction effects were detected mainly between the two major QTLs. Implications of these results for durable resistance breeding strategies, and possible benefits from the Populus genome sequence, are discussed.

Basidiomycota↗

PubMed2004

Genetic analysis of phenotypic variation for ectomycorrhiza formation in an interspecific F1 poplar full-sib family.

A plant's capability to develop ectomycorrhizal symbiosis is under the control of both genetic and environmental factors. In order to determine the roles played by these different factors, we have performed a quantitative genetic analysis of the ability of poplar trees to form ectomycorrhizas. Quantitative genetics were applied to an interspecific family of poplar for which the two parental genetic maps had already been described, and for which data analyses concerning fungal aggressors were obtained. Quantitative trait loci (QTL) related to ectomycorrhiza formation were identified and located in the genetic maps of the two parents. One QTL was located at a linkage group of the genetic map of Populus trichocarpa showing a high concentration of several QTL involved in the pathogenic interaction with the fungus Melampsora larici-populina, the causal agent of leaf rust.

Basidiomycota↗

PubMed2003

Food safety of allergic patients in hospitals: implementation of a quality strategy to ensure correct management.

Food allergy could affect up to 8% of children. Four cases of food anaphylaxis in hospitalized children are reported, pointing to the need of food allergenic safety procedures in hospital settings. The implementation of the operating procedure in hospital food production units (HFPU) of Nancy University Hospital is described. The dietetics Department developed on hypoallergenic diet and specific avoidance diets. Dieticians within HFPU managed the choice of starting materials, the circuit organization in order to avoid any risk of contamination during preparation and cooking of food, product traceability, and trained the staff of HFPU. Within the care units physicians, dieticians, nurses, hospital workers are involved in meal management. A diet monitoring sheet is integrated into the patient's nursing file and enables the dietician to validate the diet in the computer, the nurses to display the patient's diet on the schedule on the wall in their office. The hospital workers finally use a tray form indicating the patient's identity, his/her diet and the menu of the day. Such a procedure absolutely secures the whole circuit and specifies the responsibilities of each person, whilst ensuring effective cooperation between all partners. Since 1999, the implementation of this multi-step strategy has prevented from any further reaction in a department specialized for food allergies in children and in adults. As setting up food allergenic safety in hospitals in not addressed adequately in the European directives, it's judicious to draw attention of hospital catering managers and hospital canteen staff to this necessity.

Acetic Acid↗

PubMed2001

Interlaboratory study for the validation of an ecotoxicological procedure to monitor the quality of septic sludge received at a wastewater treatment plant.

Septic tank sludge is regularly hauled to the Montreal Urban Community (MUC) wastewater treatment plant. It is then discharged and mixed with the wastewater inflow before entering the primary chemical treatment process. An ecotoxicological procedure integrating chemical and toxicological analyses has been recently developed and applied to screen for the illicit discharge of toxic substances in septic sludge. The toxicity tests used were the Microtox, the bacterial-respiration, and the lettuce (Lactuca sativa) root elongation tests. In order to validate the applicability of the proposed procedure, a two-year interlaboratory study was carried out. In general, the results obtained by two independent laboratories (MUC and the Centre d'expertise en analyse environnementale du Quebec) were comparable and reproducible. Some differences were found using the Microtox test. Organic (e.g., phenol and formaldehyde) and inorganic (e.g., nickel and cyanide) spiked septic sludge were detected with good reliability and high efficiency. The relative efficiency to detect spiked substances was > 70% and confirms the results of previous studies. In addition, the respiration test was the most efficient toxicological tool to detect spiked substances, whereas the Microtox was the least efficient (< 15%). Efficiencies to detect spiked contaminants were also similar for both laboratories. These results support previous data presented earlier and contribute to the validation of the ecotoxicological procedure used by the MUC to screen toxicity in septic sludge.

Environmental Monitoring↗

PubMed2001

Genetic variation within and between populations of Pinus sylvestris L. (Scots pine) for susceptibility to Melampsora pinitorqua Rostr. (pine twist rust).

The genetic variability of Scots pine (Pinus sylvestris L.) for twist rust susceptibility and the consequences for genetic improvement of the species were evaluated after artificial inoculation of 1-year-old seedlings in greenhouse tests. Wind-pollinated progenies, factorial and incomplete diallel mating designs were used to compare two natural populations of Scots pine (Haguenau, France, and Taborz, Poland) and their hybrids (Haguenau x Taborz). Families from Taborz were significantly (P < 0.001) less susceptible to twist rust than those from Haguenau. Inter-population hybrids were as susceptible as the Haguenau population. No clear relationship between severity of infection, shoot length and phenological stage at time of inoculation was observed in intra- and interpopulation crosses. Differences observed between the two natural populations for their response to twist rust are suggested to be the consequence of local adaptation simultaneously for climatic conditions and pathogen pressure. Within each of the two populations, the effects of general combining abilities (GCA) for rust susceptibility were predominant, although estimation of individual heritabilities remained at a moderate level (0.30-0.54). In interpopulation crosses, GCA effects of Haguenau and Taborz populations were still predominant. Moreover, hybrid performance could be predicted with confidence based on the intrapopulation GCA values of parents. Genetic gain on twist rust resistance could be achieved quickly through intrapopulation mass or backward selection based on wind-pollinated progeny tests.

Basidiomycota↗

PubMed2000

Dual effect of laparoscopy on cell-mediated immunity.

Laparoscopic influence on cell-mediated immunity and tumour evolution is controversial. The objective of the present study was to assess tumour growth and immune patterns after laparoscopy on an experimental study. Lewis rats, bearing an intrapancreatic ductal carcinoma randomly underwent one of the following 2-hour procedures: anaesthesia, laparotomy or CO(2) pneumoperitoneum. Cell-mediated immunity was investigated through determination of serum IL1beta concentrations by ELISA and TNFalpha, IL6 and iNOS gene transcriptions in blood white cells and peritoneal cells by RT-PCR 1 day after operation. Tumour growth and spread patterns were assessed on anatomopathological examination 2 weeks after surgery. Tumour growth and spread were unaffected no matter what procedure was applied, but port-site seeding occurred in half of the cases undergoing laparoscopy. No significant change in acute-phase protein response, represented by IL1beta serum concentration, was found after laparoscopy. TNFalpha, IL6 and inducible NO synthase gene transcriptions were enhanced in blood white cells and depressed in peritoneal immune cells after laparoscopy. In our experimental conditions, cell-mediated immune response to CO(2) pneumoperitoneum seems to be a good systemic immune activation and a less acute peritoneal immune response as opposed to control laparoscopy. This early impairment of peritoneal macrophage immune activity, observed after a long-lasting CO(2) pneumoperitoneum, might be responsible for the high rate of port site recurrence.

Animals↗

PubMed1996

Fate and impact of pesticides applied to potato cultures: the Nicolet River basin.

The fate of cash-crop (potato) pesticides was monitored from the fields on which they were applied to the nearby streams. The investigation took place in the Nicolet River basin in the province of Quebec, Canada. The main pesticides under study were aldicarb, fenvalerate, metribuzin, and phorate. Aldicarb was never detected in any of the samples. The other pesticides were all detected in soils at low concentrations. Only fenvalerate and metribuzin were detected in tile drain. Metribuzin concentrations of up to 0.25 microgram/g were detected in the soil giving rise to a concentration of 1.3 micrograms/liter in tile drain and 47.1 micrograms/liter in surface runoff. Low concentrations of metribuzin up to 0.41 microgram/liter were detected in the nearby streams. The CREAMS model simulating pesticide movement in the fields overestimated metribuzin losses in the runoff at a concentration of 107 micrograms/liter. The subsurface EXPRES model using a PRZM time series adequately estimated a metribuzin field subsurface runoff concentration of 0.5 microgram/liter. According to the Canadian Water Quality Guideline for the protection of aquatic life, the concentrations of pesticides found in surface waters of this potato-growing region of Quebec do not have a potential to impact on the aquatic life in these systems.

Aldicarb↗

PubMed1996

Habituation of the orienting response to stimuli of different functional values in 4-month old infants.

In experiments on infant attention, the sudden presentation of a stimulus elicits an orienting response (OR). Its persisting presence then reinforces its visual exploration. When subsequently projected, this stimulus comes to signal the availability of something to look at. The aim of the present study was to sort out the effect of these three functional values of stimuli on OR elicitation. Fifty 4-month-old infants (M = 120 days) were randomly assigned to one of three experimental conditions. In Condition 1, they received 12 presentations of a 2-s visual stimulus. In Condition 2, the same 12 short stimuli presentations were accompanied by the projection of another event, visible after having the infant's gaze oriented toward the first stimulus. Condition 3 was a infant-control procedure: the same stimulus was repeatedly presented and remained on for as long as the infant looked at it. In each condition, half of the infants were shown a 4 x 4 checkerboard pattern, the others a 8 x 8 pattern. After this phase of repetitive presentation of one checkerboard pattern, the other was presented for two test trials, followed by two dishabituation trials with the initial first pattern. When the eliciting function of the stimulus (Condition 1) was isolated, orienting responses decreased over trials, and were of different latencies, according to stimulus complexity. On the other hand, the isolated function of the stimulus (Condition 2) raised its capacity to elicit ORs. Stimulus complexity was a determining factor in OR habituation, in attention recovery and in dishabituation for Conditions 1 and 3, but it was overshadowed by its signaling function in Condition 2. These results suggest the importance of taking into account the functional value of stimuli when analyzing infant attention.

Arousal↗

PubMed1996

The mismatch negativity to frequency deviant stimuli during natural sleep.

Eight subjects spent a single night in the sleep laboratory. Event-related potentials (ERPs) were recorded during the presentation of two auditory "oddball' stimulus conditions in which tonal frequency was manipulated. In the first condition, 1000 Hz "standard' and 2000 Hz "deviant' tones were presented. In the second condition, the deviant tone was reduced to 1050 Hz. In both conditions, deviant probability was 0.2. Stimuli were presented every 600 ms during wakefulness and stages 2, 4, and REM of sleep. A distinctive N1 wave was visible in both stimulus conditions when the subject was awake. The deviant stimuli elicited a "mismatch negativity' (MMN) that inverted in polarity at the mastoid. In REM sleep, an N1 and a MMN were also elicited in both conditions. In the large deviance condition, the MMN had a slightly attenuated amplitude and was shorter in duration while in the small deviant condition, its peak latency was unusually early. Neither the N1 nor the MMN could be recorded in non-REM sleep.

Acoustic Stimulation↗

PubMed1994

Effects of rate of tone-pip stimulation on the evoked K-Complex.

The effects of rate of presentation on the evoked K-Complex were examined. In different conditions, brief duration tone pips were presented every 5, 10 or 30 s. Trials were sorted into those on which a K-Complex was or was not elicited and averaged separately. The evoked K-Complex consisted of two different negative components peaking at approximately 350 and 550 ms (respectively), followed by a positive component peaking at approximately 900 ms. K-Complexes were elicited more often in Stage 2 early and 2 late than in slow-wave sleep although the differences were not significant. K-Complexes were elicited more often in the Long ISI compared to the Short and Medium ISI conditions. When a K-Complex was evoked, the amplitude of N350 and N550 was greater for the Long ISI than for the Short or Medium ISI conditions. P900 amplitude remained invariant regardless of the ISI. A micro-analysis was carried out whenever 3 consecutive occurring K-Complexes were elicited. During the Short and Medium ISI conditions, N350 and N550 following the second and third occurrence of the K-Complex were significantly attenuated compared to the first occurrence. There was no difference in N350 and N550 amplitudes among the 3 consecutive occurrences during the Long ISI condition. The decay in amplitude over consecutive occurrences of the K-Complex might be a reflection of either habituation or refractory processes.

Journal Article↗

PubMed1994

Representation of medical concepts of the thyroid gland by physicians in anatomy and pathology.

An experimental study in cognitive psychology is described, concerning the categorization of medical concepts into specific classes, expressed by physicians specialized in anatomic pathology consultations of the thyroid gland. This study belongs to a medical computer science project, called ARISTOTLE, concerning Natural Language Processing of specialized medical reports in anatomic pathology of the thyroid gland. This research has been done for two reasons; first, to specify the characteristics of human expert categorization in an area of medical knowledge and, secondly, to validate the hierarchical organization of a prototype declarative knowledge base. In this experiment, physicians were asked to categorize 121 concepts into 10 proposed classes. These classes and concepts belong to expert knowledge represented in a conceptual graph that was constructed before the experiment. Results show variable semantic distances between concepts of a same class, and dynamic variations of these distances due to contextual representation.

Artificial Intelligence↗

PubMed1992

The evoked K-complex: all-or-none phenomenon?

The functional significance and topographical variation of the different components of the evoked K-complex were examined. In the first experiment, the intensity of the stimulus (80 and 60 dB SPL) and its rise-and-fall time (2 and 20 milliseconds) were manipulated during nonrapid eye movement sleep. In the second experiment the tonal frequency (500, 1,000 and 2,000 Hz) of the stimulus was manipulated. In the first experiment, nine stimuli were presented every 10 seconds, whereas in the second, 20 consecutive stimuli were presented. The evoked K-complex consisted of two different negative components peaking at approximately 350 and 550 milliseconds, respectively, and followed by a positive component peaking at approximately 900 milliseconds. K-complexes were easier to elicit for high-intensity fast rise-and-fall time stimuli than for low-intensity slow rise-and-fall time stimuli. The probability of occurrence was not affected by the tonal frequency of the stimulus. When a K-complex was evoked, the amplitude and latency of N350, N550 and P900 remained invariant regardless of its intensity, rise-and-fall or its tonal frequency. The N550-P900 portion of the K-complex therefore appears to be an all-or-none phenomenon. On trials in which a K-complex could not be elicited, N350 was still visible although much attenuated. In these trials, its amplitude was further reduced when stimulus intensity was lowered. N350 might need to reach a certain critical threshold before the much larger N550-P900 complex is elicited.

Acoustic Stimulation↗

PubMed1991

[Enteral feeding. Principles and techniques, nutritive solutions].

A great number of nutritional solutions can be found owing to the technical progress of enteral nutrition and the diversity of available nutritive solutions. In this paper are described the various materials, their advantages and disadvantages together with the available nutritive solutions. The interests of new methods of gastrostomy by endoscopy and the progress due to the use of nutritive pumps are pointed out. Physicians can now choose the type of feeding adapted to specific nutrients requirements of the patients. They can also vary it in relation to its tolerance and the evolution of nutritional situation. Practice of enteral nutrition needs a very accurate knowledge of material, nutritive solutions and technical uses. They also have to be in agreement with the strict obligations of food hygiene.

Enteral Nutrition↗

PubMed1989

Organization of Genes Required for the Oxidation of Methanol to Formaldehyde in Three Type II Methylotrophs.

Restriction maps of genes required for the synthesis of active methanol dehydrogenase in Methylobacterium organophilum XX and Methylobacterium sp. strain AM1 have been completed and compared. In these two species of pink-pigmented, type II methylotrophs, 15 genes were identified that were required for the expression of methanol dehydrogenase activity. None of these genes were required for the synthesis of the prosthetic group of methanol dehydrogenase, pyrroloquinoline quinone. The structural gene required for the synthesis of cytochrome c(L), an electron acceptor uniquely required for methanol dehydrogenase, and the genes encoding small basic peptides that copurified with methanol dehydrogenases were closely linked to the methanol dehydrogenase structural genes. A cloned 22-kilobase DNA insert from Methylsporovibrio methanica 81Z, an obligate type II methanotroph, complemented mutants that contained lesions in four genes closely linked to the methanol dehydrogenase structural genes. The methanol dehydrogenase and cytochrome c(L) structural genes were found to be transcribed independently in M. organophilum XX. Only two of the genes required for methanol dehydrogenase synthesis in this bacterium were found to be cotranscribed.

Journal Article↗

PubMed1988

The hamster polyomavirus transforming properties.

The hamster papovavirus (HaPV) is a polyomavirus isolated from hair follicle tumor arising spontaneously in newborn hamsters which can also induce lymphoma and leukemia. This tissue specificity displayed in vivo can be bypassed in vitro since HaPV carries the full transforming properties of a polyomavirus (immortalization and transformation). We report here the phenotypic characterization of cells that were selected as immortalized or transformed and express constitutively the HaPV early genes. The viral genome is integrated in the host DNA and the early region is actively transcribed and translated.

Animals↗

PubMed1986

The hamster papovavirus: evolutionary relationships with other polyomaviruses.

The hamster papovavirus (HaPV) is a polyoma virus with a restricted tumor spectrum. It is actively replicated in hair follicle tumors arising spontaneously in young Syrian hamsters. It can also induce lymphomas and leukemias in newborn hamsters. The complete nucleotide sequence of a cloned HaPV has been established recently. This report presents a comparison of this sequence with other polyomavirus genomes (polyoma, SV40, BKV, LPV) by matrix dot analysis and electron microscopy heteroduplex mapping. The results demonstrate a close relationship between the HaPV and the murine polyoma virus and designate the LPV as the closest relative among the primate polyomaviruses.

Animals↗

PubMed1985

A new member of the polyomavirus family: the hamster papovavirus. Complete nucleotide sequence and transformation properties.

The hamster papovavirus (HapV) is associated with multiple skin epitheliomas of the Syrian hamster. We have sequenced its genome. It is a double-stranded circular DNA of 5366 bp. The hypothetical genomic organization deduced from this nucleotide sequence is clearly of the polyoma type with the two strands coding in the opposite directions from a noncoding region that shows some of the features of a replication origin and a transcription control region. The amino acid sequences predicted from the open reading frames show an average of 50% homology with polyoma-coded polypeptides. The HapV is, after polyoma, the second example of a papovavirus coding for a middle T antigen. The cloned DNA can immortalize primary rat embryo cells and transform an established rat cell line. The viral DNA is stably integrated into the host genome.

Animals↗

PubMed1985

Restriction endonuclease cleavage map of the DNA of hamster papovavirus.

A detailed restriction map of hamster papovavirus (HaPV)-DNA has been constructed on the basis of the complete nucleotide sequence of the viral genome. The HaPV DNA restriction map is totally divergent from those of all other recently known papovaviruses. This map will be useful for future functional studies of the HaPV genome.

Animals↗