Search PubMed⌕ Search

Biomedical subjects

M Bouvier

Publications and source records attributed to M Bouvier.

At least 217 records · Page 12Linked to original sources
PubMed1986

Effects of acute and chronic administration of sotalol on the blood pressure and the sympathoadrenal activity of anesthetized deoxycorticosterone acetate-salt hypertensive rats.

Using plasma catecholamine (CA) levels as an index of the sympathoadrenal activity, the effects of chronic and acute beta-blockade on the blood pressure and sympathetic activity were evaluated in deoxycorticosterone acetate (DOCA) - salt hypertensive (HT) rats. The acute administration of one beta-blocker (sotalol, 5 mg/kg) to intact of vagotomized anesthetized HT animals induced a significant decrease in plasma norepinephrine (NE) concentrations and mean arterial pressure (MAP). The amplitude of the decrease of the MAP or NE levels were linearly correlated with the basal NE levels, suggesting that sotalol reduced the blood pressure and sympathetic NE release more efficiently in rats with increased sympathetic activity. Similarly, chronic infusion of sotalol (1.5 mg X day-1 X rat-1) through an osmotic pump for 12 days in DOCA-salt HT rats significantly reduced NE and epinephrine (E) plasma levels compared with those observed in untreated DOCA-salt HT rats. Moreover, the chronic treatment with sotalol significantly reduced the plasma E elevation induced by bilateral carotid occlusion (CO) in vagotomized normotensive (NT) and HT rats. It therefore appears that acute administration of sotalol to HT rats causes a significant reduction in the sympathetic activity which is associated to a decrease in MAP. Although chronic sotalol treatment causes a significant reduction in the sympathoadrenal basal activity and in the adrenal reactivity, this treatment did not prevent the development of DOCA-salt hypertension.

Adrenal Glands↗
PubMed1986

[Determination of serum proline iminopeptidase activity using a fluorescent substrate in patients with Paget's disease and prostatic bone metastases. Preliminary results].

Assessment of proline iminopeptidase activity in serum has been performed in 80 control subjects, 14 Paget's diseases and 10 patients with prostatic and osteoblastic bone metastases. In normal subjects, the PIP activity rises with age, mainly (+63%) in women after menopause. In benign or malignant osteoblastic bone diseases PIP activity is elevated and slightly related to urinary hydroxyproline excretion (r = 0.76) which evolution is close to. It is concluded that PIP activity dosage in serum may provide with urinary hydroxyproline, further information for the study of collagen metabolism in osteoblastic bone diseases during treatment.

Adult↗
PubMed1986

[Relation between the cellularity and lactic acid level in 55 synovial fluids and research on concentration profile as a function of the etiology].

The authors investigated 55 determinations of synovial lactic acid in 7 groups of patients: septic arthritis, seropositive rheumatoid arthritis, seronegative rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitic arthritis, reactive arthritis, mechanical fluids of osteoarthritis. Statistical analysis confirmed the diagnostic contribution of this determination in septic arthritis and demonstrated a correlation between the lactic-acid and cell levels within a cell-level range of 5,000-20,000. A significant difference was detected between seronegative and seropositive forms of arthritis. The physiopathologic interpretation of the findings in cases of rheumatoid polyarthritis and in non-rheumatoid inflammatory rheumatism is discussed.

Anaerobiosis↗
PubMed1985

Increased apparent norepinephrine release rate in anesthetized DOCA-salt hypertensive rats.

Using a technique developed by Esler et al in man, we determined the NE spillover rate in plasma, the NE clearance and plasma NE concentrations in chloralose anesthetized control and DOCA-salt hypertensive rats. The study was undertaken with the infusion of tracer concentrations of high specific activity tritiated norepinephrine. Determination of the steady state of circulating NE specific activity provided an estimate of NE clearance and release rate. As previously reported endogenous plasma NE levels were greatly increased in DOCA-salt hypertensive rats. The NE clearance was only slightly decreased while the spillover rate was significantly increased in those animals. It can thus be concluded that the increased plasma NE levels observed in DOCA-salt animals cannot be attributed primarily to a diminished NE clearance rate but mainly to an increased diffusion from the sympathetic synaptic cleft to the plasma. Moreover, a significant linear correlation was found between the apparent release rate and the mean arterial levels whereas no correlation was found between the NE clearance and the blood pressure. Since the spillover rate is closely related to the NE release rate from sympathetic endings, this study supports the hypothesis that DOCA-salt hypertension is clearly associated with an enhanced basal sympathetic fibers activity.

Animals↗
PubMed1985

Action of trimebutine in cat and rabbit colon: evidence of an opioid-like effect.

Because trimebutine (TMB) is a drug that modulates colonic motility, we have attempted to determine the modifications of electrical activity underlying the motor effects of this drug. Experiments have been carried out on cat colon in vivo and on rabbit proximal colon in vivo and in vitro. The action of TMB (0.5-2 mg/kg in vivo; 10(-7) M-10(-6) M in vitro) consisted of an initiation or of an increase of spike potential activity that was unaffected by atropine (0.1 mg/kg for the cat, 2-3 mg/kg in vivo and 10(-6) M in vitro for the rabbit) and by hexamethonium (1.5 mg/kg for the cat and 2 mg/kg in vivo or 10(-6) M in vitro for the rabbit). In the cat under atropine, spike activity became cyclical, i.e., bursts of spikes were interrupted by periods of electrical silence. In the cat, TMB decreased the amplitude of excitatory junction potentials. Under atropine, TMB induced rhythmic variations in the amplitude of inhibitory junction potentials for 30 to 40 min. In the rabbit under TMB, excitatory junction potentials were enhanced whereas inhibitory junction potential amplitude was decreased. All the effects of TMB on spontaneous activity as well as on junction potentials are very similar to those observed in a previous work with morphine and enkephalins. The effects of TMB, unaffected by guanethidine, were antagonized by naloxone (2 mg/kg in vivo, 10(-6) M in vitro). These results suggest that opiate receptors, presumably located on intramural neurons, are involved in the effects of TMB.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗
PubMed1984

[Ankylosing spondylarthritis. Pathogenesis of the destructive disco-vertebral lesions. 15 cases].

Fifteen cases of destructive disco-vertebral lesions discovered in patients with ankylosing spondylitis are reported. The incidence of these lesions was 5.5% and they were unrelated to underlying conditions. Radiologically, they fell into five categories: pseudodystrophic, pseudotuberculous, extensive erosions, bone condensation and isolated narrowing of the intervertebral spaces. From an analysis of these 15 cases and of published data, it would appear that these forms result from different pathogenetic processes: an inflammatory process for the pseudodystrophic and pseudotuberculous forms and for early extensive erosions; a mechanical process for bone condensation and perhaps also (though this is more controversial) for late extensive erosions and isolated intervertebral narrowing.

Adolescent↗
PubMed1984

The effect of dietary consistency on gross and histologic morphology in the craniofacial region of young rats.

Three groups of weanling rats and three groups of juvenile rats were fed diets which differed in physical consistency for periods of 5 and 8 weeks, respectively. In both the weanling and juvenile rats, one group was fed a soft diet, a second group was fed a hard diet, and a third group was initially fed the soft diet and then was switched to the hard diet for the remainder of the experimental period. The effects of these differences in dietary consistency on gross and histologic morphology of the craniofacial region were examined. Significant differences were found in the dimensions and morphology of the condyle and condylar cartilage as a result of the differences in dietary consistency in both the weanling and juvenile groups. Soft-diet rats generally had smaller condyles and a thinner layer of condylar cartilage than either hard-diet or soft/hard-diet rats. Little change, however, was found in the overall dimensions of the mandible and maxilla in any of the groups of rats.

Animals↗
PubMed1984

Neuronally mediated interactions between urinary bladder and internal anal sphincter motility in the cat.

The effects of stimulation of vesical afferents on the electrical activity of the internal anal sphincter were studied in anaesthetized cats. Excitation of vesical afferents, either by electrical stimulation of nerves running at the vesico-ureteral junction or by bladder distension, produced (1) an increase in the electrical activity of the internal anal sphincter which was abolished by the alpha-blocker phentolamine (1.5 mg/kg, I.V.); (2) an inhibition of the excitatory response evoked in the internal anal sphincter by stimulation of one hypogastric nerve. This effect was blocked by naloxone (2 mg/kg, I.V.). These reflexes were abolished by hexamethonium (1 mg/kg, I.V.). Both reflexes were unaffected by section of sacral spinal roots (S1-S3) or by administration of atropine (0.1 mg/kg, I.V.). This excludes any participation of the parasympathetic nervous system. The excitatory and inhibitory reflexes were only slightly affected by section of the lumbar dorsal spinal roots (L1-L7) whereas they were strongly decreased after section of the corresponding ventral roots. The reflexes were abolished after section of the remaining hypogastric nerve. These results provide evidence for crossed reflexes between urinary bladder and internal anal sphincter which are achieved partly in the lumbar spinal cord and partly within the inferior mesenteric ganglion. Some of the vesical afferent nerve fibres responsible for these interactions presumably reach the spinal cord via the lumbar ventral spinal roots.

Action Potentials↗
PubMed1984

Location of sequences in polyomavirus DNA that are required for early gene expression in vivo and in vitro.

To define the DNA sequences required for the expression of the polyomavirus early transcription unit, we cloned part of the viral genome in a plasmid vector, isolated mutants bearing lesions introduced in vitro within DNA sequences upstream of the transcriptional start site, and measured the capacity of these various mutant genomes to transform cells and to function as templates for transcription in vitro by comparison with wild-type DNA. One set of mutants bore 5' unidirectional deletions beginning at position -810 and extending downstream to position +4. Another set of mutants bore 3' undirectional deletions starting at position +4 and progressing upstream to position -311. The last set of mutants bore internal deletions between positions -810 and +4. Analyses of the properties of these mutant DNAs led us to conclude that the region between positions -403 and -311 includes an enhancer of gene expression. Deletion of this area from the viral genome reduced gene expression in vivo to 1 to 2% of wild-type levels, as measured by transformation assays. Moreover, this region increased the frequency of transformation of thymidine kinase-negative Rat-2 cells by the herpes simplex virus thymidine kinase (tk) gene from 5- to 20-fold. This occurred only if the polyomavirus sequences were covalently linked to the tk gene and then occurred independently of their orientation or position relative to the tk gene. A second transcriptional element is located downstream of the enhancer between positions -311 and -213. This element together with the enhancer was sufficient to bring about transformation of Rat-1 cells at nearly wild-type frequencies, and together these elements constitute the minimal sequences required for gene expression in vivo. The sequences making up the second element may be functionally duplicated downstream of position -165 (between positions -165 and -60). This was revealed by the characterization of mutant genomes with deletions between positions -349 and -60. The role of these redundant elements is not known; however, they may be analogous to the 21-base-pair repeats of simian virus 40. Finally, sequences between positions -57 and -1 were required for accurate and efficient transcription in vitro. However, this DNA stretch, which includes the TATA box and major transcriptional start sites, was not absolutely required for gene expression in vivo. We conclude that the polyomavirus promoter comprises multiple functional elements which are distributed across a DNA stretch of about 400 base pairs.

Animals↗
PubMed1984

Increased DNA and/or RNA content of synovial fluid cells in rheumatoid arthritis: a flow-cytometry study.

Flow-cytometry studies of DNA and RNA content were carried out in acridine orange-stained synovial fluid lymphocytes from 11 patients presenting with classical or definite rheumatoid arthritis. Monoclonal antibodies were used to detect specific T cell surface antigens (OKT3, OKT4, OKT8) and antigens associated with lymphocyte activation (OKIa 1, OKT10). T3 positive cell percentages were comparable to those of normal blood, although T4/T8 ratios were decreased in 4 out of 5 cases, and HLA-DR positive cells increased. Six out of 11 patients showed percentages of dividing cells varying from 2.2 to 7.2% as compared with less than 1% in the other patients and in normal blood. Nondividing cells were characterised by an increase in their RNA content compared with normal blood. A greater increase of RNA content was observed in patients with lower percentages of dividing cells, suggesting a G1/S block. Changes in cellular DNA and/or RNA contents provide a valuable parameter of lymphocyte activation, not necessarily linked to the expression of differentiation antigens by activated cells.

Adolescent↗
PubMed1984

In vivo bone strain on the dog tibia during locomotion.

Rosette and single-element strain gauges were implanted on the tibia in 2 dogs and recordings were made during locomotion on a treadmill. At foot contact and during the swing phase of locomotion, bone strains were low and directions of the principal strains were variable. There was a large shift in the directions of the principal strains at the beginning of the stance phase and bone strains were considerably higher. Peak strain occurred midway through the stance phase. At that time, the maximum principal strain (tension) was directed upwards and anteriorly between 30 and 60 degrees with respect to the long axis of the tibia. These bone strain patterns in the dog are similar to those found in sheep while both differ markedly from those found in humans.

Animals↗