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Biomedical subjects

M Poirier

Publications and source records attributed to M Poirier.

At least 73 records · Page 4Linked to original sources
PubMed1988

The application of immunoassays and fluorometry to the detection of polycyclic hydrocarbon-macromolecular adducts and anti-adduct antibodies in humans.

The metabolic activation of polycyclic aromatic hydrocarbons (PAH) to chemical species that form covalent adducts with cellular macromolecules (DNA and protein) is central to theories of carcinogenesis. Assays are currently being developed that will accurately reflect human macromolecular exposure to these carcinogens. Immunoassays are capable of detecting low levels of PAH-DNA adducts and antibodies directed against these adducts in humans and HPLC/spectrophotofluorimetry allows the detection of carcinogen-DNA or carcinogen-protein adducts in human peripheral blood. Both types of method have inherent advantages and disadvantages, and the use of more than one type of corroborative assay is a feature in our work. Simplified but highly specific synchronous fluorescence spectra have been obtained for BP-tetrols after mild acid hydrolysis and HPLC of sample materials. When using a wavelength difference of 34 nm to drive the excitation and emission monochromators simultaneously, the pyrene fluorophore, when present, has a signature peak at 345 nm (excitation). The results of immunoassays demonstrate human exposure to PAH as a class of carcinogen, since serological cross-reactivity of antibodies does not limit detection in this system to a single chemical compound. In addition the formation in humans of anti-PAH-DNA antibodies has been shown, presumably in response to both past and present exposure to the parent compounds. In summary the results of each assay can indicate human exposure to PAH and have the potential for molecular dosimetry of this exposure.

Antibodies↗
PubMed1988

Effects of five alpha-blockers on the hypogastric nerve stimulation of the canine lower urinary tract.

Electrical stimulation of the hypogastric nerve increased both urethral and bladder pressures of anaesthetized male dogs, without affecting cardiovascular parameters. Intravenous injections of prazosin, phentolamine, thymoxamine, phenoxybenzamine and yohimbine inhibited the urethral pressure increase in a dose-dependent manner, but the increase in bladder pressure was not modified by these alpha-blockers.

Adrenergic alpha-Antagonists↗
PubMed1988

[Empoverishment and social integration of psychiatric adults.].

Social integration of young adult psychiatric patients is seen differently by those who dispense psychiatric and institutional services, and the people who use those services. Institutional personnel are caught in a web of contradictions, living the strange ambivalence of an institution which must deinstitution-alize its clientele. On the other hand, the young adult using mental health services sees the impact social integration will have on his quality of life : is life "outside" possible when both institutional organization and conditions within society contribute to impoverishing one's personality and resources?

English Abstract↗
PubMed1986

Biomonitoring of workers exposed to carcinogens: immunoassays to benzo(a)pyrene-DNA adducts as a prototype.

A new tool for the study of occupational carcinogenesis is "molecular dosimetry" or biomonitoring to establish the biologically effective dose of carcinogens in workers. Human monitoring of biologically effective dose and preclinical response has the potential to flag the need for protective measures and/or surveillance. Comparable biologically effective dose and preclinical response data in humans and laboratory animals for whom tumor incidence is known can also enhance risk extrapolation between species. This paper will provide a brief overview of biomonitoring methods now under development, including advantages, limitations, applications to date, and research needs. Application to the monitoring of worker populations requires careful thought about the use to which monitoring data will be put.

7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide↗
PubMed1986

Cardiac and renal hyperplasia in newborn genetically hypertensive rats.

Newborn spontaneously hypertensive rats (SHR), compared with Wistar-Kyoto (WKY) controls, usually show cardiac and renal hyperplasia. To determine whether these anomalies are common to genetically hypertensive rats, we examined newborn rats from models of essential hypertension (Kyoto, Montreal, Dunedin and Lyon strains of hypertensive rats), renal hypertension (Milan strain of hypertensive rats) and experimental hypertension [deoxycorticosterone acetate (DOCA)-salt hypertensive Wistar rats]. The hearts, kidneys and livers of these newborns were collected on site at various centres and sent to Montreal for protein and DNA determinations. The results showed that protein and DNA, corrected for body weight in models of essential hypertension, were increased in the heart and kidney, and normal or decreased in the liver at birth. This pattern differed in offspring of the Milan strain (renal hypertension) and of DOCA-salt hypertensive animals (experimental hypertension). Since cardiac and renal hyperplasia associated with the hypertensive trait in four different genetic models of spontaneous hypertension was distinct from that observed in renal and experimental hypertension, it is conceivable that a specific cardiovascular growth pattern is a reflection not of a simple linkage or consequence, but of a causal association with spontaneous hypertension.

Animals↗
PubMed1985

Diminished type I collagen synthesis and reduced alpha 1(I) collagen messenger RNA in cultured fibroblasts from patients with dominantly inherited (type I) osteogenesis imperfecta.

Type I osteogenesis imperfecta (OI) is characterized clinically by a moderate fracture frequency with minimal bone deformity and dominant inheritance. Previous studies of the collagenous proteins synthesized by dermal fibroblasts obtained from unrelated patients with this form of OI suggested that the biochemical basis of the disease was reduced production of type I collagen. This study was designed to determine if this biochemical finding segregated with the disease within an individual family. Dermal fibroblast strains were established from three generations of a family having the typical features of type I OI. Analysis of the collagenous proteins made in culture revealed an elevated alpha 1(III) to alpha 1(I) collagen type ratio and an elevated alpha 1(I) to alpha 2(I) collagen chain ratio. The procollagen that accumulated in the medium reflected these ratios to the same degree. Total collagen synthesis was significantly reduced in affected family members. Therefore, the most striking abnormality in affected members was a 50-75% reduction of type I collagen production. Furthermore, the ratio of the alpha 1(I)/alpha 2(I) collagen messenger RNA (mRNA), measured by dot hybridization, was one-half of the value of uninvolved family members and unrelated controls. Since the reduction in the production of type I collagen and the altered alpha 1(I)/alpha 2(I) mRNA ratio clearly segregated with affected individuals within this family, these biochemical measurements may be a useful genetic marker for type I OI.

Adult↗
PubMed1980

[Metrizamide radiculography with simplified dynamic test (author's transl)].

The development of metrizamide, a recent hydrosoluble contrast medium, has opened up the possibility of dynamic lumbosacral radicolugraphy, but in the opinion of the authors only the upright position is adequate to accentuate or reveal new pathological appearances. This was the case in 68 out of 100 consecutive radiculographies performed.

Back Pain↗