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Biomedical subjects

G Bernier

Publications and source records attributed to G Bernier.

At least 19 recordsLinked to original sources
PubMed1991

Changes in mRNA level rhythmicity in the leaves of Sinapis alba during a lengthening of the photoperiod which induces flowering.

A previous study has shown that mRNAs exhibit complex patterns of diurnal rhythms in their quantity in the leaves of Sinapis alba during an 8 h light/16 h dark short day (SD). In order to determine whether this situation is rapidly modified in plants subjected to an extended light treatment, we have used in vitro translation and two-dimensional polyacrylamide gel electrophoresis, together with a strict gel comparison procedure giving a P = 0.03 certitude level, to analyse the mRNA complement at different times during a 22 h light/2 h dark long day (LD). During this LD, complex changes affected about 10% of the mRNAs. Thirty-four different patterns were observed. Some diurnal rhythms present in SD are not modified by the lengthening of the light period, but most are affected. Moreover, we have shown that some mRNAs presenting a constant quantity under a SD regime show an increase or a decrease during the first hours of the photoperiod lengthening. In Sinapis, this LD also induces flowering. All the changes in mRNA quantity detected thus parallel the photoperiodic induction of flowering in the leaves and are quantitative; no mRNA was shown to appear or to disappear.

Electrophoresis, Gel, Two-Dimensional↗
PubMed1987

Ecogenetics of Parkinson's disease: prevalence and environmental aspects in rural areas.

We make use of the unique combination of a homogeneous genetic and racial origin in the rural population of Quebec and the facilities of free and universal access to medical care, to study the distribution of the prevalence of Parkinson's disease in the 9 rural hydrographic regions of the Province. Through 3 different methods of ascertainment, confirmed by two control probes, we demonstrate that the prevalence of Parkinson's disease is of uneven distribution within rural areas. We further investigated the characteristics of the regions of high prevalence. These regions which are predominantly agricultural and areas of intensive market gardening were also the areas with the highest use of pesticides.

Geography↗
PubMed1986

The flowering process as an example of plastic development.

The field of flowering has been characterized by simplistic ideas, as exemplified by the attempts to classify plants on the basis of the kinds of environmental factors required for their transition to flower initiation and the claims that the process of flower formation in photoperiodic and cold-requiring plants is independent of correlative influences from various organs, e.g. the roots. Other examples of this simplified picture are the concept of a specific leaf-generated floral hormone and floral inhibitor and the search at the level of the meristem of a specific evocational event which would set in motion the whole sequence of other events and commit the meristem to flower initiation. Finally, there is the belief that because flower morphology is basis to species classification the morphogenesis of flowers is a rather invariable process. All these ideas are essentially erroneous and it is shown that all aspects of the flowering process are much more flexible than is usually believed. Floral induction may be completed by many, if not all, plants in several alternative sets of environmental factors. At least in some plants, the alternative inductive factors are perceived by different organs, indicating that these factors affect most probably entirely different processes. Thus, at induction, plasticity is extremely large and the fate of any shoot meristem appears to be controlled by a complex and flexible array of promoters and inhibitors arising from all plant parts. At meristem evocation, there are a number of events which are fundamentally the same in many plants, but so far no single initial critical event has been found. The various evocational changes appear to form sets of interconnected systems and this complex network seems to embody some plasticity since it has been possible to suppress experimentally some of the most universal evocational events or alter their temporal order without impairing evocation itself. At later stages, it has been observed that all the morphological characters of inflorescences and flowers may be experimentally altered. However, if the occasional and extreme malformations (monstrosities) caused by some growth substances are excluded, morphogenetic processes do not appear flexible to the point that the reproductive structures of one species are transformed into those of a taxonomically unrelated species. Thus, despite the fact that these processes are never absolutely fixed, plasticity at morphogenesis appears less than that at induction.(ABSTRACT TRUNCATED AT 400 WORDS)

Light↗
PubMed1977

[Necrotic enteritis in broiler chickens. III. Study of the factors favoring the multiplication of Clostridium perfringens and the experimental transmission of the disease].

Necrotic enteritis was reproduced experimentally in two week old broiler chickens by intravenous injection and also by oral administration of a pure culture of Clostridium perfringens. In the first experiment, gross and microscopic intestinal lesions, typical of necrotic enteritis, were observed in all diseased birds and mortality was obtained only in the group of birds that were injected with 0.4 ml or more of the pure culture of the microorganism. In the second experiment, the highest mortality was noted in the group of birds that received orally, in addition to the Clostridium culture, a solution of sodium bicarbonate, to obtain an alkaline intestinal content and opium to decrease the intestinal peristaltism. The gross and microscopie intestinal lesions of the diseased and killed birds were more severe than those observed in the other groups and were similar to those encountered in field outbreaks of necrotic enteritis.

Animals↗
PubMed1974

[Necrotic enteritis in broilers. I. Clinoco-pathological aspect].

This study represents an analysis of the principal clinical factors and pathological lesions of 150 cases of necrotic enteritis encountered during 1968 and 1969 in Quebec. Following multiple investigations no common factor was observed which might have explained the pathogenesis of the condition which was observed during every month of the year, especially from May to November. Birds two to four weeks of age were the most susceptible. The main lesion was a fibrino-necrotic enteritis always localized in the small intestine, either in its entire length or just a segment and characterized by the disappearance of the surface epithelium and necrosis of the villi. The lumen was filled with desquamated epithelial cells and bacteria. Foci of coagulation necrosis were observed in the liver and foci of nephrosis in the kidneys. A Gram+ bacillus, strictly anaerobic, was always isolated from the viscera.

Animals↗
PubMed1974

[Necrotic enteritis in broilers. II. Characteristics of the strains of Clostridium perfringens isolated].

A Gram positive bacillus, strictly anaerobic, was isolated from the viscera of all diseased birds showing lesions of necrotic enteritis. Its morphology and biochemical reactions, the presence of alpha and thêta hemolysins and the production of a lecithinase-C in vitro, all these characteristics indicated a similarity to those belonging to the group of Clostridium perfringens. The two hemolysins were neutralized in vitro only by the antitoxin A. Broiler chickens injected I.V. with a Viande-Foie (VF) broth culture of Clostridium perfringens together with the antitoxin A survived, whereas those receiving antitoxin C died. These results seem to indicate that this organism belongs to the type A. This bacillus was sensitive to a great variety of antibiotics, except neomycin.

Animals↗