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Biomedical subjects

M Bouvier

Publications and source records attributed to M Bouvier.

At least 253 records · Page 14Linked to original sources
PubMed1981

The relationship between split-line orientation and in vivo bone strain in galago (G crassicaudatus) and macaque (Macaca mulatta and M. fascicularis) mandibles.

There is still disagreement concerning the functional significance of split-line patterns in bone. This study was undertaken to reexamine the mechanical forces hypothesis for split-line formation by comparing split-line patterns with in vivo mandibular bone strain patterns. The relationship between split-line orientation and in vivo stress and strain patterns on macaque and galago mandibles was examined during jaw opening and the power stroke of mastication and incision. An attempt was made to relate split-line orientation to the direction of tensile stress and strain along the primate mandible. In addition, we also investigated the alternative possibility that split-line orientation is related to the direction of low stresses (and strains) on the primate mandible. The results of this study showed that there was no consistent relationship between split-line orientation and the principal strains or stresses. Thus, split-lines did not run consistently in the direction of high or low stress and strain. Therefore, we have concluded that split-line orientation provides little useful information for inferring patterns of stress and strain in bone.

Animals↗
PubMed1981

Effect of bone strain on cortical bone structure in macaques (Macaca mulatta).

It has recently been shown that the consistency of food significantly affects levels of bone strain in the mandible during mastication (Hylander, '79a). Mandibular bone histology was examined to test the effects of a diet of hard food compared to a diet of soft food in two groups of monkeys. One group of rhesus macaques (Macaca mulatta) was fed a diet of commercially prepared hard biscuits. The second group was fed a soft diet the consistency of fudge. Both diets were nutritionally adequate for normal growth and development. As a control for other factors influencing cortical bone structure, fibular morphology was also examined. At the end of the test period, mandibular and fibular tissue samples from the two groups were prepared to determine the amount of secondary Haversian bone present. Mandibular depth at M2 and fibular anteroposterior diameter were also measured and compared between the two dietary groups. The soft-diet monkeys showed low levels of remodeling in their mandibles. There were large patches of unremodeled bone and resorption spaces were common. The hard-diet monkeys exhibited more extensive evidence of secondary Haversian remodeling in their mandibles. The hard-diet monkeys also had deeper mandibles. In contrast, the fibulae from the two groups had similar mean diameters and showed comparable levels of secondary remodeling. We infer that the higher mandibular bone remodeling levels in the hard-diet monkeys represent an adaptive response to remove and replace fatigued mandibular bone due to higher stress levels associated with the ingestion and mastication of hard foods. We also infer that greater depth of the mandible at M2 found in the hard-diet group represents an adaptive response to higher stress levels associated with the ingestion and mastication of hard foods.

Animals↗
PubMed1981

Electrical activity from smooth muscle of the anal sphincteric area of the cat.

1. The electrical activities of longitudinal and circular smooth muscle of the anal sphincteric area have been studied in the cat. 2. Electromyographic recordings were achieved with extracellular electrodes, in vivo on acute and chronic animals, and in vitro on the isolated organ. In addition, electrical and mechanical activities were recorded from muscle strips with the sucrose gap technique. 3. Circular muscle coat electrical activity consisted exclusively of slow variations of the membrane potential of the smooth muscle cells. Each slow potential variation was followed by a contraction. 4. The electrical activity and the concomitant contractions were tetrodotoxin resistant (10(-6) g/ml.). Both disappeared in Ca-free solution or in the presence of Mn ions (10(-3) M). 5. On circular muscle, noradrenaline (10(-8)-10(-7) g/ml. in vitro, or 0.1-0.15 mg/kg in vivo) had an excitatory effect consisting in an increase of slow potential frequency. The action of noradrenaline was antagonized by phentolamine (10(-6)-10(-5) g/ml. in vitro, or 0.2 mg/kg in vivo). 6. On circular muscle, acetylcholine (10(-8)-10(-6) g/ml.), used exclusively on muscle strips, did never produce any clear cut effect. 7. Longitudinal muscle coat electrical activity consisted of spike potentials superimposed on slow time course depolarizations which were never observed alone. Each spike was followed by a contraction. This electrical activity was tetrodotoxin resistant (10(-6) g/ml.). 8. Longitudinal muscle activity was abolished by noradrenaline (10(-6) g/ml.) and enhanced by acetylcholine (10(-8)-10(-6) g/ml.). The action of noradrenaline was antagonized by propranolol (0.2 mg/kg I.V.; 10(-6) g/ml.) and that of acetylcholine by atropine (10(-7) g/ml.). 9. Electrophysiological and pharmacological data indicate that electromechanical coupling is achieved (1) in circular muscle, through Ca dependent slow variations in membrane potential of the muscle cells and (2) in longitudinal muscle, through spike potentials. Noradrenaline has opposite effects on the two muscle coats: circular muscle is excited through alpha-receptors located on muscle cells membrane; longitudinal muscle is inhibited through beta-receptors. Acetylcholine excites longitudinal muscle through muscarinic receptors, but it has no effect on circular muscle.

Acetylcholine↗
PubMed1981

Nervous control of the internal anal sphincter of the cat.

1. The effects of sympathetic and parasympathetic efferent nerve stimulation on the activity of longitudinal and circular coats of th anal sphincteric area have been studied on acute animals using extracellular electrical recordings. In addition, the effect of intramural sympathetic nerves stimulation has been investigated on anal sphincteric circular muscle, with the sucrose gap technique. 2. Hypogastric nerve stimulation elicited in anal sphincteric circular muscle slow time course depolarization responses (latency 200-400 msec) which were abolished by alpha-adrenergic blockers (dihydroergotamine, phentolamine). 3. Stimulation of the parasympathetic outflow to the internal anal sphincter (second ventral sacral root: VS2) inhibited spontaneous electrical activity of the circular muscle. Pharmacological arguments lead to the conclusion that the inhibition induced by VS2 stimulation is mediated through intramural non-adrenergic non-cholinergic (purinergic) inhibitory neurones. 4. Rectal distension caused an inhibition of the anal sphincteric circular muscle activity which persisted in the presence of atropine, phentolamine and propranolol, indicating that this inhibition was produced by non-adrenergic non-cholinergic intramural neurones. 5. VS2 stimulation produced only an activation of the longitudinal muscle of the sphincteric area, which was abolished by hexamethonium and atropine; in contrast, hypogastric nerve stimulation gave rise to an inhibition which was blocked by propranolol. These results indicate that the longitudinal muscle receives (1) an excitatory innervation from preganglionic parasympathetic nerves connected with intramural cholinergic neurones, and (2) an inhibitory sympathetic innervation from noradrenergic axons running in the hypogastric nerves. No inhibitory no-adrenergic non-cholinergic innervation was observed in the longitudinal muscle in response to VS2 stimulation. 6. The results obtained from simultaneous stimulation of VS2 and hypogastric nerves indicate that in the anal sphincteric circular muscle the release of noradrenaline from sympathetic nerves is modulated by cholinergic receptors located on noradrenergic nerve endings, muscarinic receptors which can abolish the release of noradrenaline, and probably nicotinic receptors which increase the noradrenaline release. The eventual functional significance of the nicotinic receptors is discussed.

Anal Canal↗
PubMed1981

[Medical treatment of osteoarticular tuberculosis].

The authors report 45 personal cases observed over the last ten years, from a series of 520 cases collected during a multi-centre enquiry of the French Society of Rheumatology and a review of the literature; they discuss the present tendencies in the treatment of bone and joint tuberculosis. Antibiotic and chemotherapy uses drugs which are more and more effective, easier and easier to manipulate, ensuring in almost all cases a lasting cure with frequent conservation of joint function, shortening the natural course of the disease, and preventing or curing its complications. The role of surgery thus becomes more restricted, the period of rest may be shortened and it may becomes less strict in many cases; on the other hand, physiotherapy is becoming more important in this treatment. As for the possibility of shortening antibiotic therapy, and although the experience obtained from lung tuberculosis is encouraging, the absence of comparably large series in bone and joint tuberculosis should make one circumspect.

Antibiotics, Antitubercular↗
PubMed1981

[Vitamin-sensitive osteomalacia in condensing bone metastases of prostatic origin. Apropos of 2 cases].

In connection with two observations histologically proved on a metastasic territory of osteomalacia appeared during osteocondensing metastases of prostatic origin, the authors underline the responsibility of sudden increase of osteoformation in the hypocalcemia genesis and put the emphasis on the transitory aggravating function of the given high doses of estrogen within negative calcium balance. A D vitamin deficiency, frequent among old patients, could increase osseous manifestation of calcium supply insufficiency responsible of an authentic osteomalacia. This deficiency is not secondary to a phosphorus diabetes and is amended by an important calciu addition and by the administration of D vitamin metabolites as proved by repeated osseous biopsy with dynamic and histomorphometric studies.

Aged↗
PubMed1981

[HLA and rheumatoid arthritis].

In a study on the frequency of the HLA A, B, C and DR antigens seen in 100 controls and 31 patients with rheumatoid arthritis, the authors found a significant increase in the DR4 antigen in rheumatoid arthritis. (50% as against 25%; X2 = 8,5; 0,04 greater than Pc greater than 0,008; RR = 3,43). The other antigens on loci A, B. C and DR are not altered significantly. However the increase in DR4 which does not seem to be related to the severity of the rheumatoid arthritis, seems to be proportional to the level of rheumatoid factor. The authors review literature on HLA in rheumatoid arthritis and the figures for the antigenic frequency of HLA-DR4 are compared with their own results. The findings are of interest especially from a pathogenic point of view.

Adult↗
PubMed1980

[Left superior vena cava simulating abnormal pulmonary venous return].

The case of a seven year old boy with coarctation of the aorta and a left superior vena cava (SVC) draining into the left atrium is reported. Usually, in this condition the circulation is centripedal, descending from the left SVC to the left atrium and leading to systemic cyanosis or desaturation. In this case, the circulation was centrifugal and ascending from the left atrium to the left SVC to the innominate vein, leading to a left-to-right shunt as in abnormal pulmonary venous return. The left-to-right shunt flow was 4.2 l/mn and the ratio of pulmonary to systemic flow was 1.8: there was no pulmonary hypertension. This type of circulation is very rare and only two other cases were found in the literature. It may be explained by the proximity of the left pulmonary veins to the left SVC and by a functional mitral obstacle due to the increased pulmonary return. Simultaneous correction of the coarctation and ligature of the left SVC was carried out by left thoracotomy without cardiopulmonary bypass.

Aortic Coarctation↗
PubMed1980

[Pseudopottic and pseudodystrophic forms of spondylodiscites of ankylosing spondylitis. Four personal cases and 20 observations from the literature].

On the basis of four personal cases and of 20 cases taken from the literature, the authors outline the radioclinical aspects of the pseudo-pottic forms of ankylosing spondylitis and distinguish, aside from forms very closely resembling a microbial lesion, pseudodystrophic forms whose appearance is very close to that of intraspongious hernias.

Adult↗
PubMed1979

[Disfiguring ulcer forms of the carpal tunnel syndrome].

On the basis of 3 personal cases and 13 cases in the literature, the authors carried out a study of these rare forms of the carpal tunnel syndrome. The syndrome itself generally has a unique character marked on the etiologic level by a frequent occurrence of unilateral and post-traumatic forms, and on the clinical level by the existence of severe sensitivo-motor, vasomotor and trophic problems; it rarely resembles Raynaud's syndrome. The cutaneous lesion most often appears as a torpid ulceration located on the forefinger and/or the second finger and involving the palmar surface or the sub-ungual region of the 3rd phalanx. Cutting of the ligament of the middle finger, whether or not accompanied by an additional surgical act, is almost always followed by a regression of the classical signs and the curing of the ulcerations.

Aged↗
PubMed1979

[Osteoid osteoma of the foot. Apropos of 4 personal cases].

On the basis of four personal cases of osteoid osteomas of the foot, the authors study their frequency, their localization, and their clinical and radiological manifestations. They insist on the special difficulties of diagnosing this condition due to its atypical and uncertain radiological outline, and also on methods of further investigation : arteriography and especially isotopic scintigraphy.

Adolescent↗
PubMed1978

[The treatment of Paget's disease using salmon thyrocalcitonin. 8 cases (author's transl)].

An open trial of synthetic salmon thyrocalcitonin was carried out in 8 cases of progressive and multifocal Paget's disease over a period of three months and at a dose of 80 MRC.U twice daily. A clinical improvement was seen in half the cases. The action was also marked upon laboratory parameters with, in particular, an average decrease in alkaline phosphatase of 51% and in urinary hydroxyproline levels of 29.4%.

Alkaline Phosphatase↗