Biomedical subjects

G Rouleau

Publications and source records attributed to G Rouleau.

40 records · Page 3Linked to original sources

PubMed1987

Guinea pig bronchus as a model for icosanoid studies.

Strips of guinea pig bronchus dissected from the upper, middle, and lower lobe and divided in two segments referred to as external and internal bronchi, were analyzed for their reactivity to several icosanoids. The external bronchi produced much more contractile force than the internal bronchi, and the reactivity to the agonists was different. The order of potency of prostanoids and histamine on the external bronchus was U44069 congruent to histamine greater than PGF2 alpha and on the internal bronchus U44069 greater than histamine greater than PGF2 alpha. The internal bronchus did not react to PGE2, whereas this agonist produced a dose-dependent relaxation on the external bronchus. The order of potency of leukotrienes and histamine on the external bronchus was LTD4 greater than LTC4 greater than LTE4 greater than LTA4 greater than histamine and on the internal bronchus LTC4 greater than LTD4 greater than LTA4 = LTE4 greater than histamine. LTB4 has a significant myotropic activity on guinea pig bronchus. Because of its sensitivity and characteristic responses to icosanoids, it is suggested that the guinea pig bronchus may be as suitable (and possibly more) a pharmacological preparation as the trachea or the parenchyma to study the bronchoreactivity.

Animals↗

PubMed1987

DNA linkage analysis in Von Recklinghausen neurofibromatosis.

We have used DNA linkage analysis in 11 families with Von Recklinghausen neurofibromatosis (VRNF) in order to search for the chromosomal localisation of the defective gene causing this serious neurological disorder. Three groups of polymorphic DNA markers were used: (1) markers for chromosome 22, because of possible allelic genetic heterogeneity between VRNF and bilateral acoustic neurofibromatosis; (2) markers near the centromere of chromosome 4, since there was preliminary evidence for linkage between the VRNF gene and Gc; and (3) oncogenes and growth factors as possible candidate genes for VRNF. Our data exclude close linkage between any of these markers and the gene for VRNF.

DNA↗

PubMed1987

Models for inherited susceptibility to cancer in the nervous system: a molecular-genetic approach to neurofibromatosis.

Neurofibromatosis (NF) is one of the most frequent and clinically important Mendelian disorders in man, with an incidence of 1 in 3,000. While different organ systems and cell types can be affected in NF, the most common abnormalities are in cells of neural crest origin. Two distinct forms of NF have been described: 'peripheral' or von Recklinghausen NF (VRNF) and 'central' or bilateral acoustic NF (BANF). VRNF is characterized clinically by hyperpigmented patches of skin and multiple tumors of the peripheral and central nervous system, which can cause disfigurement, paralysis, blindness and death. In comparison, BANF is characterized by the bilateral occurrence of acoustic neurinomas (Schwann cell-derived tumors of the 8th cranial nerve) and increased susceptibility to certain other nervous system tumors, including meningiomas and gliomas. These tumors can lead to deafness and other serious neurological morbidity and mortality within the first few decades of life. The primary biochemical defects in both forms of NF is not yet known, but is of great fundamental interest in view of the potential role of these genes in controlling proliferation and differentiation of neural crest cells. Here we discuss different molecular-genetic approaches towards identifying these defective genes. In particular, our studies on tumors associated with BANF have specifically implicated chromosome 22 as the location of the gene defect causing this serious neurological disorder. The identification and characterization of the NF genes, based on their chromosomal localizations, will have profound implications for diagnosis and treatment of these diseases and might yield significant insights into mechanisms controlling development and differentiation of the human nervous system.

Chromosome Aberrations↗

PubMed1986

Neurocysticercosis: surgical and medical management with praziquantel.

Eight cases of neurocysticercosis were encountered at the two major neurological centers affiliated with McGill University in Montreal in 4 years. All patients were immigrants who had been in Canada for a period of 1 to 18 years and came from South America (three cases), Haiti (three cases), and Greece (two cases). Five patients had parenchymal cysts and presented with epilepsy; three had the racemose form and presented with hydrocephalus. Four patients with parenchymal cysts were treated by removal of the cysticercus and did well. One patient with numerous cysts was treated with praziquantel with good clinical and radiological results. Two patients with the racemose form were treated by cyst aspiration, cerebrospinal fluid (CSF) diversion, and praziquantel and did well. Another patient with the racemose form, seen before the advent of praziquantel, died of cysticercosis infection. Neurocysticercosis is not uncommon in the immigrant population of large North American cities. Single symptomatic cysts can be evacuated surgically with good results; multiple parenchymatous cysts can be treated with praziquantel. Patients with the racemose form who are treated with CSF diversion and praziquantel do well, although those who are only treated surgically die of their disease.

Adult↗