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J Mathieu

Publications and source records attributed to J Mathieu.

At least 91 records · Page 5Linked to original sources
PubMed1990

Local and systemic effects of an acute inflammation on eicosanoid generation capacity of polymorphonuclear cells and macrophages.

Acute non-specific inflammation was induced in rats by injection of isologous serum into the pleural cavity. Pleural and peritoneal cells were collected at various times after pleurisy induction and tested for production of leukotriene B4 (LTB4), prostaglandin E2 (PGE2) and prostacyclin (PGI2) after in-vitro stimulation with calcium ionophore A23187. Cells obtained by lavage of pleural and peritoneal cavities of normal rats were used as controls. Increased production of LTB4, PGE2 and PGI2 by pleural cells was observed 3 days after pleurisy induction, but with a significant depression of PGI2 release at 3 h. As the relative proportions of polymorphonuclear cells (PMN) and macrophages in the inflammatory exudate varied during the development of inflammation, these cells were examined separately for LTB4 production. PMN and macrophages contributed equally to the liberation of this mediator in normal and inflamed rats. Similar qualitative and quantitative changes in LTB4 production by pleural cells were observed, irrespective of the type of irritant used (isologous serum, dextran, carrageenan, microcrystals). In contrast, intrapleural injection of saline had no significant effect. In order to determine whether local inflammation may influence mediator release by phagocytic cells at remote sites, peritoneal cells were collected 3 or 72 after pleurisy induction. The production of LTB4, PGE2 and PGI2 was increased at 72 h. Mediator production by peritoneal macrophages was observed in both normal and inflamed rats. In conclusion, acute non-specific inflammation provoked increased arachidonic acid metabolite generation by phagocytes both locally and at a distance: this occurred more than 24 h after pleurisy resolution.

6-Ketoprostaglandin F1 alpha↗
PubMed1990

[Motor and sensory neuropathies with or without agenesis of the corpus callosum: a radiological study of 64 cases].

In 1971, Andermann and Andermann described an autosomal recessive syndrome found within the Charlevoix and the Saguenay populations (Quebec, Canada) characterized by agenesis of the corpus callosum (ACC) associated with motor and sensory neuropathy, mental retardation and dysmorphic features. A study of CT in 64 patients demonstrated a total ACC in 37 cases (57.8%), partial ACC in 6 cases (9.4%) and the presence of the corpus callosum in 21 cases (32.8%). The latter was confirmed by MRI in 3 cases. CT of patients without ACC revealed a high frequency of developmental or degenerative midline anomalies, particularly interhemispheric fissure enlargement and posterior fossa atrophy. The clinical presentation and the natural course of the neuropathy, the intellectual impairment and the behavioural manifestations are identical amongst individuals with or without ACC. Individuals with or without ACC are found within the same family and often within the same sibship. These observations support the hypothesis of a single genetic syndrome in which the constant manifestation is the motor and sensory neuropathy.

Adolescent↗
PubMed1989

Partial syndrome of myotonic dystrophy: clinical presentation and follow-up.

The neurological and ophthalmological investigation of 602 members of 88 Saguenay kindreds affected by myotonic dystrophy (MyD) revealed 130 persons with a partial syndrome. These patients, whose average age was 34.1 years, showed different abnormalities such as particular ophthalmic and/or neuro-muscular signs, suggesting MyD in the absence of myotonia or typical lens abnormalities. After an average period of 2.4 years, 44 of these 130 patients were reassessed by the same neurologists and ophthalmologists. Thirty still had a partial syndrome, 8 showed a typical form of MyD and 6 no longer presented any identifiable anomaly. This preliminary follow-up study of the partial MyD syndrome did not allow us to identify any clinical anomaly from which the presence of the MyD gene could be predicted in a significant way. It furthermore suggested that the identification of equivocal or unspecific signs among these patients can sometimes lead to misdiagnosis. This must be taken into account when providing genetic counselling. It furthermore indicates that the use of DNA probes is essential for a reliable identification of asymptomatic MyD gene carriers.

Adolescent↗
PubMed1989

Origin and diffusion of the myotonic dystrophy gene in the Saguenay region (Quebec).

A very high prevalence (approximately 1/475 in 1985) of myotonic dystrophy (Steinert disease) is observed in the Saguenay region, which is located in the north-east part of the Province of Quebec. For various reasons, however, the literature on the subject generally associates a high degree of selective disadvantage with this gene, which seems to contradict the Saguenay data. Using a computerized regional population register, we have reconstituted patients' genealogies and family biographies. We have thus been able to study the origin of the gene and to compare the demographic behavior of patients and controls. On the whole, patients seem to be very little disadvantaged compared to controls, in terms of reproduction as well as of geographical and occupational mobility.

Female↗
PubMed1989

Hypertriglyceridemia and lower LDL cholesterol concentration in relation to apolipoprotein E phenotypes in myotonic dystrophy.

Plasma lipid, lipoprotein levels and apolipoprotein apo E phenotypes were determined in 70 patients with myotonic dystrophy (MyD) and 81 controls. Marked differences were noticed in the apo E phenotype frequencies between the two groups. Plasma triglycerides and VLDL cholesterol were higher in MyD than controls, but only the latter was related to differences in the apo E phenotypes between two groups. Accordingly, the ratio of VLDL cholesterol/plasma triglycerides was increased significantly in MyD, suggesting accumulation of intermediary density particles due to lower affinity of E2 containing lipoproteins for lipoprotein cell receptors. The LDL cholesterol concentration was lower in MyD than controls and was related to differences in the apo E phenotype frequencies between the two groups. These results indicate increased removal of LDL particles in the apo E2 phenotypes, perhaps due to upregulation of LDL (B, E) receptor activity. Plasma cholesterol and HDL cholesterol concentrations were similar in both groups. Another feature of the study was lower levels of plasma cholesterol, triglycerides, VLDL and LDL cholesterol in the homozygous E4:E4 phenotype. These results suggest increased clearance rate of both VLDL and LDL particles and support the concept that apo E4-containing lipoproteins have higher in vivo affinity for ape E and/or B, E receptors.

Adolescent↗
PubMed1989

Myotonic dystrophy: linkage with apolipoprotein E and estimation of the gene carrier status with genetic markers.

The genes for myotonic dystrophy (MD) and for apolipoprotein E (ApoE) belong to a chromosome 19 synthenic group of markers. A familial linkage analysis between MD and ApoE was performed using the J Ott LIPED program (IBM PC/XT, April 1984) to estimate the genetic distance between these 2 genes. Of a total of 136 individuals in 11 MD families, 81 were confirmed to be affected by the disease and 41 were asymptomatic. ApoE phenotypes were determined in 115 of these 122 individuals. No recombinant was observed out of 74 meioses which were informatives for both MD and the ApoE isoproteins. A global maximal lod score Z of 19.00 was obtained at the recombination fraction theta = 0. The upper theta value at the confidence interval corresponding to the peak lod score (Z max) - 1 was 0.03. This suggests that the loci for MD and ApoE are at a distance of 0 to 0.03 Morgan. Since ApoE and apolipoprotein C2 (ApoC2) have been shown by others to be about 40 kb apart, our data are therefore consistent with the distance estimate of 0.02 Morgan reported between MD and ApoC2. The D19S19 (LDR152) polymorphic DNA sequence is also tightly linked to MD on chromosome 19. The segregation of ApoE isoproteins and of ApoC2 and D19S19 DNA polymorphism was utilized for evaluating the probability for individuals at risk of inheriting the disease gene in MD families. Data are presented on 3 families to emphasize the usefulness of genetic markers to estimate the MD gene carrier status of asymptomatic individuals and also for those presenting a partial syndrome. The limitations of such approach are also discussed.

Apolipoproteins E↗
PubMed1989

Ascertainment of informative Alzheimer disease families from the IMAGE Project registry for genetic linkage analysis studies.

Genetic linkage analysis requires the identification and documentation of large families with many affected members present, preferably in more than one generation. The IMAGE Project has been establishing a population-based Alzheimer disease (AD) registry in the Saguenay - Lac-Saint-Jean region of the Province of Quebec. The population of this region has a well-documented ancestry, with reliable genealogical records (since 1842) computerized by SOREP. We have recently begun to investigate the pedigrees of selected probands (definite, probable and possible) from the IMAGE registry in order to identify informative pedigrees for genetic linkage analysis. Interviews were carried out with close relatives of the probands (at least one informant per sibship) to identify secondary AD cases. The questionnaires used pertain to the accuracy of genealogical records, to family medical history and to a retrospective diagnosis of AD for people with cognitive deficits. By these means, we have documented a large extended pedigree in which a total of 15 individuals with cognitive deficits were ascertained over three generations. Of these cases, 7 are still living and there is autopsy confirmation in another one. Computer simulations using the program SIMLINK revealed that this is a potentially informative family for linkage analysis. Horizontal extension of the pedigree to second cousins of the proband is now being carried out. This will render the family IMAGE/1 even more informative in genetic linkage analysis studies.

Alzheimer Disease↗
PubMed1989

Familial factors in Alzheimer's disease (IMAGE project). A case-control study in the Saguenay-Lac-St-Jean region (Quebec, Canada).

Alzheimer's disease is now recognized as a major public health problem. Many hypotheses have tried to explain the etiology of Alzheimer's disease and, among them, genetic factors are considered one of the most plausible. A case-control study of familial factors, including sex distribution, age at onset, birth order, parental age, fertility, mortality, inbreeding and kindship, was conducted on 130 clinically diagnosed patients born in the Saguenay-Lac-St-Jean region (Quebec, Canada). The cases were screened by the IMAGE project. Our results showed that most factors studied are not associated with Alzheimer's disease. Inbreeding was found to be slightly increased in the Alzheimer group. Kindship was higher in the Alzheimer group than in the control groups, therefore confirming that familial predisposition is a very important risk factor.

Adult↗
PubMed1989

Pulsatile release of gonadotropin-releasing hormone from hypothalamic explants is restrained by blockade of N-methyl-D,L-aspartate receptors.

We have shown previously that N-methyl-D,L-aspartate (NMDA) and kainate, two neuroexcitatory amino acids acting through distinct receptors, may induce the release of GnRH from hypothalamic explants. However, that effect could have no physiological significance, since very high concentrations (50 mM) of NMDA and kainate were required. Here, using agents blocking the activation of receptors to neuroexcitatory amino acids, we evaluated their possible physiological involvement in the pulsatile release of GnRH from the hypothalamus of 50-day-old male rats in vitro. In control conditions (10 nM glycine and 1 mM mg2+), the release of GnRH in 7.5-min fractions collected for 2-4 h showed an obvious pulsatile pattern. The mean (+/- 1 SD) interval between pulses, identified by PULSAR program, was 34.3 +/- 11.4 min. The stimulation of GnRH release by NMDA (50 mM) added to the medium for 7.5 min could be blocked reversibly in the presence of MK-801 (100 microM) using medium without glycine or enriched with Mg2+ (2 mM). The endogenous pulses of GnRH secretion were abolished in the presence of MK-801 or using increased Mg2+ concentrations as well as in the absence of glycine. In contrast, pulsatile release of GnRH was not affected in the presence of 6,7-dinitroquinoxaline-2,3-dione (0.1 mM), a selective inhibitor of kainate and quisqualate receptors which suppressed the increase in GnRH release induced by kainate (50 mM) without affecting the response to NMDA. These data indicate that the physiological mechanism of pulsatile GnRH secretion in the hypothalamus may involve endogenous neuroexcitatory factors acting through NMDA-sensitive receptors.

Animals↗
PubMed1989

[Myotonic dystrophy: I. Socioeconomic and residential characteristics of the patients].

Myotonic dystrophy is a dominantly inherited genetic disorder which, in medical literature, has been linked to peculiar socio-economical conditions. In order to document this assertion, a sociological study was conducted in the Saguenay-Lac-Saint-Jean region (Québec), using a representative sample (N = 218) drawn from the myotonic dystrophy population. A study of the patients' places of residence was also carried out. The results clearly indicate that myotonic dystrophy patients exhibit a socio-economic profile associated with disadvantaged milieux: high unemployment, low income and limited schooling. Many of these patients must rely on social welfare. Two families out of five (42%) live beneath the poverty line. The wage-earning history of these persons is closely linked to their self-evaluation of their working capabilities. After the age of forty, a high proportion of these people are unable to hold down a paying job and claim they are unable to do so. Within a well-screened urban area, a study of the patients' places of residence indicates census tracts where myotonic dystrophy is concentrated (ecological niches). These social areas are close to the downtown area and display characteristics of disadvantaged milieux. Accordingly, the My D gene seems to be confined to a specific socio-economic and socio-geographical environment, through which the spread of the gene is channelled among the population.

Adolescent↗
PubMed1989

[Myotonic dystrophy: II. Marital status, fertility and gene transmission].

A sociological study, using a representative sample (N = 218) of the myotonic dystrophy population, made possible an analysis of the relationship between certain demographic characteristics (marriage, fertility) and the mechanisms involved in the transmission of the deleterious gene. The results show a clear differentiation between the marriage rate of women and men affected by myotonic dystrophy. Whereas men show a considerable decline in marriage eligibility, women continue to marry at a young age and in a proportion almost equal to that of the unaffected population. The study also indicates that the average fertility rate among married patients in the Saguenay-Lac-Saint-Jean exceeds the fertility rate reported from affected populations found in other countries. Our study shows an above-normal male fertility rate. This demographic fact explains the overrepresentation of male transmitters noted in the affected population. However, if present trends remain unchanged, women will be more likely to transmit myotonic dystrophy to future generations. These conclusions illustrate how the transmission and spread of a dominant gene follow a pattern that cannot be dissociated from the socio-cultural characteristics taken as a whole, particularly demographic characteristics. They also provide us with useful avenues for setting up future prevention programmes.

Adolescent↗
PubMed1988

Modulation of leucocyte activation in the early phase of the rabbit burn injury.

Previous studies in burned patients have shown an early enhanced polymorphonuclear leucocyte (PMN) generating capacity for superoxide radical (O2.-), for the arachidonic acid (AA) lipoxygenase metabolite leukotriene B4 (LTB4) and for platelet activating factor-acether (PAF). These findings have been confirmed on a burn injury rabbit model. As we have suggested a pivotal role for an exaggerated initial (less than 36-48 h) neutrophil stimulation leading to a later (greater than 72 h) immuno-depression and anergy, we tried to modulate the early phase by drug therapy. A Ginkgo biloba extract (IPS200) injected i.v. in burned rabbits greatly reduced O2.- and LTB4 generation on A23187 challenge. IPS200 includes flavonoids and other polyphenols, inhibiting either arachidonic acid metabolism or PAF receptors, and may thus exert their modulating effect on PMN function in thermal injury.

Animals↗
PubMed1988

[Spreading of the gene for myotonic dystrophy in Saguenay (Quebec)].

The prevalence of the myotonic dystrophy (Steinert disease) is about 1/475 in the Saguenay region, located in the North-east of the province of Québec (Canada). About 600 cases are currently known in a population of 285,000 inhabitants. This disease is an autosomal dominant disorder which causes a general muscular degeneration. Usually, it is also associated with a lower fertility, if not sterility, among the affected families. Another element of the phenotype is a higher infant mortality rate among cases. In the light of those traits, the very high prevalence of the disease in the Saguenay population becomes rather puzzling. It is the subject of this research. Using a computerized population register, we have been able to analyze the genealogies of the patients and their family history. In the overall, two basic factors account for the wide transmission of the gene: a) an immigration stream from a neighbouring region (Charlevoix) may have brought between 57 and 77 patients into the Saguenay since 1840; b) the cases proved to be by and large as fertile as controls (an average of 9.2 births among 85 affected families). The paper also presents a genealogical inference program used to ascertain cases among ancestors, along with data on the history of the gene, nuptiality, geographical and occupational mobility. In the overall, we have not been able to bring out an important selective disadvantage against the patients.

Female↗
PubMed1982

[Thermal stability of carbonates in bone tissue].

The analysis shows that carbonate ions present in the mineral phases of calcified tissues are decomposed in two steps during their ignition. These carbonate ions might be all localised in the phosphate sites of the apatitic structure (B type carbonate apatite). The loss of one important part of carbonate ions at a abnormally low temperature (250 degrees C) might result from an intracristalline reaction between these ions and HPO4(2-) or P2O7(4-) ions present in the apatitic structure.

Animals↗
PubMed1981

[Not Available].

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Canada↗
PubMed1980

Intermittent claudication of the hand after creation of an arteriovenous fistula in the forearm.

Eighty-five patients were followed up at least 1 year after creation of an arteriovenous fistula in the forearm. The anastomosis was side-to-side in 33 patients, end-to-side in 33 and end-to-end in 19. Trophic lesions were not observed. Intermittent claudication of the hand was more frequent in patients with a side-to-side arteriovenous fistula (42 percent) than in those with end-to-side (21 percent) or end-to-end fistulas (16 percent). Clinical and x-ray studies indicate that two different mechanisms are responsible for cramping pains: arterial steal phenomenon and venous hypertension. Their relative importance depends on multiple hemodynamic factors that may vary with time.

Adolescent↗
PubMed1980

Contribution of angiography in bladder cancer.

Pelvic angiography was performed in 24 patients with primary or secondary tumours. 17 patients were submitted to arteriography and 7 to phlebography of the pelvis veins. An angiographic classification was established and compared to the pre-operative and histopathological results determining tumour staging. These results were compared to those obtained by bimanual palpation under narcosis and demonstrated the significant contribution of angiography in determining the extravesical spreading of bladder tumours.

Adenocarcinoma↗