Search Results - (Author, Cooperation:J. Tremblay)

2012-08-04

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Actinobacteria/genetics/isolation & purification ; Arabidopsis/classification/growth & development/*microbiology ; Endophytes/*classification/genetics/*isolation & purification ; Genotype ; In Situ Hybridization, Fluorescence ; *Metagenome ; Plant Roots/classification/growth & development/*microbiology ; Proteobacteria/genetics/isolation & purification ; RNA, Ribosomal, 16S/genetics/isolation & purification ; Rhizosphere ; Ribotyping ; Sequence Analysis, DNA ; *Soil Microbiology ; Symbiosis

2018-10-16

The Company of Biologists

0950-1991

1477-9129

Biology

1471-4159

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

This study demonstrates the presence of both atrial natriuretic peptide (ANP) precursor and ANP transcripts in the rat olfactory bulb (OB), a key brain structure involved in the generation of olfaction-dependent behavior. In addition to synthesizing ANP, the OB contains ANP-transducing receptors coupled to the guanylate cyclase system but it is devoid of ANP “clearance receptors.” The characterization of biologically active ANP receptors and the evidence for in situ ANP synthesis in this region of the CNS adds credence to the hypothesis that the peptide plays a putative role in olfaction.

Electronic Resource

1471-4159

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

—Injection of a soluble protein fraction from mouse brain into rabbits gave rise to an antibody which was specific for galactocerebroside. The antigen had the following characteristics: (1) it was present in the soluble fraction of a mouse brain homogenate but absent from the soluble fraction of homogenates of mouse liver, spleen, kidney and testis; (2) it was non-dialysable; (3) it voided from a Sephadex G200 column; (4) on immunodiffusion with antibody directed against it, it gave a sharp single precipitin band; (5) it bound to DEAE cellulose column and was eluted with high salt. Given these characteristics the antigen might have been identified as a ‘brain specific protein’. However, the lipid nature of the antigen was revealed when it was found that it was not destroyed by Pronase digestion and could be quantitatively extracted with chloroform-methanol. The antigen has been identified as a galaetocerebroside and is 100 times more abundant in the myelin fraction than in the soluble fraction of the mouse brain homogenates. The antigen could have been falsely identified as a ‘brain specific protein’ if the antigenicity and macromolecular behaviour of lipids was overlooked.

Electronic Resource

1749-6632

Blackwell Publishing Journal Backfiles 1879-2005

Natural Sciences in General

Electronic Resource

1745-6584

Blackwell Publishing Journal Backfiles 1879-2005

Energy, Environment Protection, Nuclear Power Engineering

Geosciences

Salt water intrusion is an acute problem in the coastal areas of Prince Edward Island. In the town of Summerside, ground-water supplies are developed from an aquifer hydraulically connected with the sea. Over the past ten years, there has been progressive contamination of the aquifer, particularly in wells close to the seashore.Investigations including test drilling, aquifer testing and chemical studies were undertaken in Summerside to study the nature and extent of the salt water intrusion.Landward encroachment of the saline water is aided by the relatively high transmissivity of the fractured Permo-Carboniferous sandstone which comprises a semiconfined aquifer. Two separate zones of salt water contamination exist—namely an upper zone from a depth of 0 to 80 feet caused by a landward hydraulic gradient of the fresh water due to heavy pumping and a second zone at a depth of 350 to 400 feet due to intermittent pumping resulting in a raising and thickening of the zone of diffusion. The extent of salt water intrusion is depicted, using hypothetical sections.

Electronic Resource

1440-1681

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

1. A significant portion of blood pressure variance is modified by the environment.2. The present report summarizes evidence that: (i) the environmental response is genetically determined; (ii) various stressors can evoke a differential response in hypertensive animals and constitute its intermediate phenotypes; (iii) the response to heat stress can be assigned to a single ‘thermosensitivity’ locus; (iv) candidate genes of susceptibility to environmental stresses are member(s) of the heat stress gene (HSP) gene families; (v) a restriction fragment length polymorphism ofhsp70 and a single base mutation in the 3′-untranslated region of hsp27 are associated with hypertension in recombinant inbred strains.3. In conclusion, HSP gene variants may be causative in susceptibility to hypertension.

Electronic Resource

1440-1681

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

1. In the present study we searched for variants of alternative splicing of guanylyl cyclase A and B mRNA in rats in vivo.2. Guanylyl cyclase A2 and guanylyl cyclase B2 isoforms of guanylyl cyclase produced by alternative splicing leading to the deletion of exon 9 of both transcripts were quantified in several rat organs.3. Only one alternative splicing was found in the regulatory domain, encoded by exons 8–15.4. Quantification of the guanylyl cyclase B2 isoform in different rat organs and in cultured aortic smooth muscle cells showed that this alternative splicing was tissue-specific and occurred predominantly in the central nervous system where the alternatively spliced variant represented more than 50% of the guanylyl cyclase B mRNA.5. The same alternative splicing existed for guanylyl cyclase A mRNA but at very low levels in the organs studied.6. Alternative splicing of guanylyl cyclase B exon 9 in the brain may play an important role in signal transduction, since the expressed protein possesses a constitutionally active guanylyl cyclase acting independently of C-type natriuretic peptide regulation.

Electronic Resource

0014-5793

Atrial natriuretic factor ; Cyclic GMP ; Glomerulus ; Particulate guanylate cyclase ; Sodium nitroprusside ; Tubule

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0014-5793

Adrenal cortex ; Atrial natriuretic factor ; Detergent ; Enzyme stimulation ; Guanylate cyclase

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0740-5472

alcohol ; cocaine ; combined treatment ; outcome ; treatment

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Medicine

Psychology

Electronic Resource

0006-291X

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0009-2614

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Physics

Electronic Resource

0196-9781

ANF release ; Clonidine ; Water deprivation

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

0168-583X

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource

0306-4603

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Medicine

Psychology

Electronic Resource

1432-1106

Synaptic transmission ; Synaptic vesicle ; Dense core ; Coated vesicle ; Ciliary ganglion

Springer Online Journal Archives 1860-2000

Medicine

Summary The Edinger-Westphal nucleus of one day old chicks was stimulated in vivo. This nucleus projects via the oculomotor nerve to the ciliary ganglion. The stimulation produces morphological changes in the calyciform endings located in the ciliary ganglion. There is a significant reduction of the numerical density on area of the clear and the dense core vesicles. The numerical density of the coated vesicles is low compared to that of the clear vesicles. Their density is however almost doubled by the stimulation. The vesicles, the vacuoles and the plasma membrane were quantified using stereological procedures. A net loss of total membrane was found due to the loss of organelle membrane not compensated for by an equivalent increase of the plasma membrane. These observations are discussed in terms of the theory of vesicular membrane recycling as proposed by Heuser and Reese (1973).

Electronic Resource

1432-0533

Key words Myoblast transplantation ; Duchenne ; muscular dystrophy ; mdx mouse ; Transgenic mouse

Springer Online Journal Archives 1860-2000

Medicine

Abstract Female mdx/mdx mice were crossed with non-dystrophic transgenic males expressing the β-galactosidase (β-gal) gene under a muscle-specific promoter (TnILacZ1/29). All male offspring were mdx mice and about 50% of them also expressed the β-gal gene. The β-gal/mdx mice were selected as recipients for the transplantation of myoblasts from non-transgenic normal BALB/c mice. When host muscles were not irradiated before myoblast transplantation, 4.6% of the muscle fibers in host muscles were dystrophin positive 1 month after transplantation. Most of these dystrophin-positive muscle fibers were also β-gal positive. About one quarter of these fibers are the result of reverse mutations; most of them have, however, been produced by fusion of donor myoblasts with host muscle fibers or with host myoblasts. The virtual absence of β-gal-negative fibers indicates that there were no exclusively donor-donor fusions. When host muscles were irradiated before myoblast transplantation, roughly the same percentage (5.5%) of dystrophin-positive fibers were formed in the injected muscle, but 42% of them were β-gal negative. These β-gal-negative dystrophin-positive muscle fibers were formed by the exclusive fusion of donor myoblasts with one another rather than with host cells. This clearly indicates that myoblast transplantation can form completely new muscle fibers or muscle fiber segments when host satellite cell proliferation is reduced by irradiation. These newly formed muscle fibers had, however, a small diameter and additional myoblast transplantation may be required to increase their size. This situation has some similarities with findings in Duchenne muscular dystrophy patients of more than 6 years of age, who also have a limited proliferation capacity of their satellite cells.

Electronic Resource

1432-1106

Neuromuscular junction ; Mouse ; Morphometric study ; Synaptic transmission ; Synaptic vesicles ; Vesicular hypothesis ; Stimulation in vivo

Springer Online Journal Archives 1860-2000

Medicine

Summary Morphometric changes have been studied at the mouse neuromuscular junction (NMJ) as a function of the frequency of stimulation. In vivo stimulation was made at either 10, 25, 50 or 100 Hz. No significant change in the area of NMJ profiles is observed after stimulation. This indicates that stimulation does not change the volume of the nerve terminal. There is also no change of the volume density of mitochondria. However, there are significant reductions of the numerical density on area (NA, number/μm2) of the clear vesicles following stimulation at 25, 50 or 100 Hz. The NA of clear vesicles is not further reduced following stimulation at 50 or 100 Hz than after the stimulation at 25 Hz. The numerical density on area of the coated vesicles was significantly increased following the stimulation at 25 Hz and 100 Hz. It is not increased more following stimulation at 50 Hz or 100 Hz than following stimulation at 25 Hz. One possible interpretation of the clear vesicle and the coated vesicle results is that less vesicles are liberated per sec by the NMJ with stimulation at 50 and 100 Hz than at 25 Hz because the action potential may fail to invade some terminal arborizations. The total surface density (i.e. surface of membrane in μm2 per μm3 of nerve terminal) of the clear vesicles, the coated vesicles, the vacuoles and the presynaptic plasma membrane is not changed significantly following stimulation at any frequency. This indicates that there is no net loss of membrane at any of the frequencies investigated.

Electronic Resource

1573-4919

DNA adducts ; liver ; fish ; 32P-postlabelling ; polycyclic aromatic hydrocarbons ; genotoxic biomarker

Springer Online Journal Archives 1860-2000

Biology

Chemistry and Pharmacology

Medicine

Abstract The levels of DNA adducts in the hepatic tissue of the white sucker fish speciesCatostomus commersoni were determined by32P-postlabelling. The fish were caught at four sites: two sites near the city of Windsor (Québec, Canada) on the St. François River, a downstream tributary of the St. Lawrence River, and two sites in the St. Lawrence River itself, near the city of Montréal (Québec, Canada). The latter sites are known to be contaminated by many pollutants including polycyclic aromatic hydrocarbons. Total adduct levels in all fish ranged from 25.1–178.0 adducts per 109 nucleotides. White sucker from the selected sites of the St. Lawrence River had a significantly higher mean level of DNA adducts than those of the St. François River (129.4 vs 56.8, respectively). These results suggest that the effluents of many heavy industries (e.g. from a Soderberg aluminium plant) flowing in the St. Lawrence River are more likely to produce genotoxic damage to fish than those released in one of its tributary, and mainly associated to the activities of a small town and a nearby pulp and paper mill.

Electronic Resource