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Biomedical subjects

M Bouvier

Publications and source records attributed to M Bouvier.

At least 199 records · Page 11Linked to original sources
PubMed1987

IgM rheumatoid factor (RF), IgA RF, IgE RF, and IgG RF detected by ELISA in rheumatoid arthritis.

One hundred patients with rheumatoid arthritis (RA), of whom 73 were seropositive by latex or Waaler-Rose (WR) assays, or both, 100 healthy subjects, and 102 diseased controls (22 patients with systemic lupus erythematosus (SLE) and 80 with bronchial asthma) were evaluated for the presence of IgM rheumatoid factor (RF), IgA RF, IgE RF, and IgG RF by an enzyme linked immunosorbent assay (ELISA). Ninety two per cent, 65%, 68%, and 66% of the patients with RA were found to be positive for IgM, IgA, IgE, and IgG respectively. A positive correlation existed between the levels of IgM RF and IgA RF on the one hand and disease activity on the other, and the levels of IgM RF and IgA RF correlated with the levels of circulating immune complexes as measured by a C1q binding assay. The presence of extra-articular features also correlated positively with the levels of IgA RF and IgE RF. Five out of six patients with Sjögren's syndrome had very high levels of IgA RF. Of 47 patients typed for HLA-DR, DR1 and DR2 were significantly more frequent in those with the highest levels of IgM RF. Conversely, DR3 was associated with low levels or absence of IgA RF and IgE RF. These results suggest that immune response genes may regulate the level of different RF isotypes. The frequencies of IgM, IgA, IgE, and IgG RF were 59%, 36%, 9%, and 27% respectively in SLE and 25%, 2.5%, 70%, and 59% in bronchial asthma.

Adult↗
PubMed1987

Abnormal regulation of the sympathoadrenal system in deoxycorticosterone acetate-salt hypertensive rats.

With the use of circulating norepinephrine (NE) and epinephrine (E) levels, the sympathoadrenal activity as well as its local modulation by adrenoceptors were studied in normotensive (NT) and DOCA-salt hypertensive (HT) rats. In anesthetized hypertensive rats, plasma NE levels were higher, whereas in conscious animals both NE and E levels were found to be increased, suggesting an increased basal sympathoadrenal tone in these animals. The finding of a close correlation between blood pressure levels and NE levels suggests that the elevation of blood pressure may be linked to sympathetic system activity in this experimental model of hypertension. The reactivity of the sympathoadrenal system was also found to be increased in DOCA HT rats. Following a bilateral carotid occlusion of 1 min, which specifically activates the adrenal medulla, the elevation of E levels was found to be potentiated in intact or vagotomized HT rats. Moreover, in response to prolonged or acute hypotension in anesthetized and conscious animals, the elevation in plasma NE and E levels was found to be markedly potentiated in DOCA HT rats. The local modulating adrenoceptor-mediated mechanisms of the sympathoadrenal system appeared to be altered in this model of hypertension. Although it was possible to demonstrate that the E response to carotid occlusion can be greatly potentiated by administration of an alpha2-antagonist (yohimbine) and completely abolished by an alpha2-agonist (clonidine) in NT rats, the E response was found to be unaffected by the same treatments in HT rats, suggesting a reduced sensitivity in the alpha2-mediated inhibitory modulation of the adrenal medulla. Moreover, the acute treatment with a beta-blocker (sotalol) lowered circulating NE levels and blood pressure only in HT rats, suggesting the possibility of a more sensitive beta-receptor-mediated presynaptic facilitatory mechanism on sympathetic fibers of these animals. Finally, it was observed that the functional balance which exists between the activities of sympathetic fibers and the adrenal medulla in normotensive animals appears to be impaired in DOCA HT rats. In conclusion, the present studies suggest that the increased sympathoadrenal tone and reactivity may be due, in part, to a variety of dysfunctions in local adrenoceptor modulatory mechanisms of the sympathoadrenal system in DOCA hypertensive rats.

Adrenal Medulla↗
PubMed1987

Red blood cell catecholamine levels in normotensive and DOCA-salt hypertensive rats.

Under basal conditions in anesthetized rats, significant concentrations of free norepinephrine (NE), epinephrine (E), and dopamine (DA) were detected in red blood cell (RBC) lysate. These concentrations were not proportional to their respective plasma concentrations and thus RBC-to-plasma concentration ratios were different for each catecholamine (CA). DA was by far the most concentrated amine inside the RBC. An acute increase in plasma NE and E levels, induced by hemorrhagic hypotension in normotensive (NT) rats, did not result in any modification of the RBC CA content. However, chronic elevation of the NE plasma levels in bilaterally adrenalectomized rats and in deoxycorticosterone acetate (DOCA)-salt hypertensive rats (DOCA-salt HT) were associated with increased NE levels in the RBC. In addition, the large elevation in plasma E concentrations following hemorrhagic hypotension in DOCA-salt HT rats, as well as the greater plasma NE response to hypotension in adrenalectomized animals, were accompanied by increases in the respective RBC amine concentrations. During a steady-state intravenous infusion of tritiated NE, we observed a slow accumulation of radioactivity inside the RBC, indicating that CA can enter the RBC from the plasma. Moreover, catechol methyltransferase activity was measured in the cytosolic fraction of the RBC of both NT and DOCA-salt HT rats suggesting that, once inside the RBC, the catecholamines can be metabolized.

Adrenalectomy↗
PubMed1987

Effects of mechanical loads on surface morphology of the condylar cartilage of the mandible in rats.

Mechanical loads on the condylar cartilage were varied by feeding either a hard diet, a soft diet, or a sequential combination of a soft diet followed by a hard diet to young male and female rats for a total period of 4 weeks, and to mature male rats for 12 weeks. Gross condylar dimensions were greatest in the hard-diet groups, intermediate in the combination soft/hard-diet groups, and smallest in the soft-diet groups. Scanning electron microscopy of the condyle revealed a smooth, nonporous articular surface in the soft-diet groups. Hard-diet condyles had a rougher, more porous articular surface while soft/hard-diet condyles were intermediate between nonporous and slightly roughened condyles. None of the condyles showed ridges or elevations on the articular surface. Sex, age and time of the diets did not significantly affect these results.

Animals↗
PubMed1987

Flattening of the rheumatoid foot in tarsal arthritis on X-ray.

222 consecutive and unselected patients suffering form classical or definite rheumatoid arthritis wee studied. 397 of their feet were examined. Talonavicular arthritis was the commonest finding (31.5% of all patients), followed by sub-talar (23.3%), cuneo-navicular (20.4%) cuneo-metatarsal (14.9%) and tibio-tarsal arthritis (12.6%). Rheumatoid disease of the tarsus becomes commoner as the disease progresses. The incidences of involvement of the talo-navicular and sub-talar joints show a similar pattern, with a leap of 25% between 5 years of duration of the disease and 10 years. The same is seen with involvement of the cuneo-navicular and cuneo-metatarsal joints, between a duration of 10 years of the disease and 15 years. The percentage of flat foot is greater in feet with tarsal arthritis (p less than 0.001). The authors observed a relationship between tarsal arthritis, the length of history of rheumatoid arthritis, and flat foot. The method of investigation is discussed, and theories about evolution of the rheumatoid foot are considered.

Adult↗
PubMed1987

[Histiocytosis X of the jaws. Apropos 5 cases].

Principal features of histiocytosis X are discussed in relation to 5 cases treated in the department. Clinical signs are known. Bone scintiscans are of importance for evaluation of extension of the disease. Surgical treatment is the rule until more effective therapy becomes available and has a diagnostic rather than curative aim. The major problem remains the progressive dental mutilation.

Adult↗
PubMed1987

[Development of spondylodiscopathies in ankylosing spondylitis].

This multicentric study concerns 43 cases of spondylodiscopathies considered, as far as evolution is concerned, according to their radiological aspect. Late erosive forms (33 cases) occur on a rigid spine, sometimes after a trauma (6 cases). The initial radiological sign may be the fracture of a syndesmophyte or of the posterior arch. The evolution of the signs (pinching, erosions, density) is variable: slow or rapid aggravation leading sometimes to an osteosynthesis, extended stabilization over several years, cure by presence of a syndesmophyte or a bony block which, beside an obvious mechanical etiology in most cases, predicts the intervention of an inflammatory factor, isolated or concomitant. Early erosive forms (3 cases) occur in a context of inflammation, on a healthy spine, and sometimes are multifocal and lead rapidly to the formation of bony blocks: they join directly in the evolution of ankylosing spondylarthritis. Pseudo-Pott and pseudo-dystrophic forms (7 cases) present a variable evolution and their interpretation remains debatable.

Adult↗
PubMed1986

Epidemiologic and genomic study of rotavirus strains infecting young children and calves in the same rural environment.

The epidemiological profile of rotavirus infection in young calves and young children form the same rural environment in France was studied during autumn-winter 1983-1984. Viruses were isolated from calves on each farm and were identified by their electropherotype for 8 out of the 9 farms under study. Among 13 children regularly checked on 9 farms for 25 weeks, 7 were found to be rotavirus positive. Nevertheless, no transfer of virus between child and bovine was documented by the electropherotype migration. In the case of the calves, the predominance of the Ib IIa IIIe IVa electropherotype at 5 of the 9 farms is similar to the epidemiological situation observed among newborn in some maternity wards.

Animals↗
PubMed1986

Increased basal and reactive plasma norepinephrine and epinephrine levels in awake DOCA-salt hypertensive rats.

The sympatho-adrenal basal tone and reactivity were studied using plasma norepinephrine (NE) and epinephrine (E) levels in awake DOCA-salt hypertensive rats. In those animals, basal NE and E levels were about twice greater than those found in normotensive rats. Moreover, plasma NE levels could be significantly correlated with mean arterial pressures in both groups of animals. Following a hemorrhagic hypotension, elevation in NE and E levels tended to be greater in hypertensive rats. These studies suggest that the basal activity of the sympatho-adrenal system is increased and that its reactivity might be potentiated in DOCA-salt hypertension.

Animals↗
PubMed1986

Actions of morphine and enkephalins on the internal anal sphincter of the cat: relevance for the physiological role of opiates.

The effects of Leu-enkephalin, Met-enkephalin and morphine on the electrical activity of the internal anal sphincter were studied in anesthetized spinalized cats and in vitro on sphincteric muscle strips. All the effects of enkephalins and morphine were antagonized by naloxone (2 mg/kg, i.v. in vivo and 10(-6)M in vitro). In vivo, the enkephalins (0.01 mg/kg i.v.) and morphine (2 mg/kg, i.v.) decreased the amplitude of the excitatory responses evoked in the sphincter by stimulation of the hypogastric nerves. Opiates presumably act on the sympathetic nerve endings by reducing the release of noradrenaline. In vitro, the enkephalins (10(-6)M) and morphine (10(-6)M) had a similar inhibitory effect, indicating that opiates act, at least partly, at intramural level. In vivo, the enkephalins and morphine produced an inhibition of the spontaneous electrical activity of the internal anal sphincter. This inhibition occurs also in vitro; it is thus due to a peripheral effect of opiates acting either directly on the sphincteric smooth muscle cells, or through the nervous structures controlling sphincteric motility. In addition, the distribution of nerves containing enkephalin-like immunoreactivity, using whole mount preparations of cat internal anal sphincter, indicates that this area is supplied with a dense Leu- and Met-enkephalinergic innervation. Met- and Leu-enkephalin-like immunoreactive axons were detected within the circular and longitudinal muscles.

Action Potentials↗
PubMed1986

Increased sympatho-adrenal tone and adrenal medulla reactivity in DOCA-salt hypertensive rats.

Sympatho-adrenal tone and reactivity were evaluated in anaesthetized normotensive and DOCA-salt hypertensive rats, by measuring arterial plasma concentrations of norepinephrine and epinephrine under basal conditions and following bilateral carotid occlusion. Baseline norepinephrine levels were significantly higher in DOCA-salt hypertensive animals than in their respective normotensive controls, whether they were studied with intact vagi or following bilateral vagotomy. The possibility of a relationship between the increased basal sympathetic fibres and the maintenance of DOCA-salt hypertension is strongly suggested by the finding of a significant correlation between mean arterial pressure (MAP) and basal circulating norepinephrine values in those animals. Furthermore, the epinephrine increase following carotid occlusion was found to be markedly potentiated in hypertensive animals (intact or vagotomized), suggesting adrenal medullary hyperreactivity to baroreflex activation in this model of hypertension. In normotensive rats the epinephrine increase induced by the carotid occlusion was greatly potentiated by the administration of an alpha 2-antagonist (yohimbine), and completely abolished by administration of an alpha 2-agonist (clonidine). In contrast, the epinephrine response to carotid occlusion, which is already enhanced in hypertensive animals, was unaffected by the same treatments. These results therefore suggest that adrenal medullary hyperreactivity observed in DOCA-salt hypertensive rats may be due to a dysfunction of an alpha 2-adrenergic mechanism modulating adrenal medullary secretion.

Adrenal Medulla↗