Early estimation of upper lateral incisor width.
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Humans↗
Biomedical subjects
C Bernard
Publications and source records attributed to C Bernard.
[Vascular smooth muscle fibers and the autonomic nervous system].
Vascular Smooth Muscle cell (V.S.M.C) plays a major role in the regulation of vasomotion. Sympathetic system play a key role in vascular smooth muscle function. Epinephrine (humoral pathway) and norepinephrine (nervous pathway) can both stimulate V.S.C.M. via delta and beta adrenergic receptors. The function of parasympathetic system is more controversial. Acetylcholine induces the release of a relaxing factor by the endothelial cell (E.D.R.F.) but it has a direct contracting effect on V.S.C.M. Neural vasodilation is also concerned by noradrenergic mechanisms.
Autonomic Nervous System↗
[Effect of hypoxia on plasma concentrations of gastrin and gastric inhibitory polypeptide (GIP) in newborn calves].
Calves were subjected to experimental hypoxia from 0.5 to 4 h after birth. The plasma level of immunoreactive gastric inhibitory polypeptide was higher (P less than 0.05) than in control calves during hypoxia and 2 and 7 h later. However, the gastrin level was not lower during treatment and was higher (P less than 0.05) 3, 6, and 13 h later. Hypoxia could have changed circulating levels or degradation rates of these peptides and could have delayed abomasal emptying.
Animals↗
[A cellular anti-ischemic agent, trimetazidine prevents the deleterious effects of oxygen free-radicals on the internal ear].
Improvement of cochleovestibular symptoms induced by trimetazidine (TMZ) has been evidenced by clinical studies. However, a poor knowledge of the physiopathology and the scarcity of experimental models contributed to making determination of the mode of action of the drugs difficult. We studied the effect, in vitro, of TMZ on the production of oxygen-derived free radicals using, as a biological model, the isolated semicircular canal of the frog. This model allows to exert separate control over the ionic composition of the endo- and perilymphatic fluids. The spontaneous activity of the afferent nerve fibers, as well as the endolymphatic potential, were recorded at rest. Three additional parameters were analyzed, while the semicircular canal was subjected to mechanical stimulation, i.e., ampulla potential, nerve potential and the evoked frequency of action potentials. Free radical generation induced by the administration of phenazine methosulfate (PMS, 10(-5) M, 15 min) into the perilymphatic compartment, leads to a deterioration of the production of endolymph and the release of this afferent neuromediator. Inversely, PMS has no influence whatsoever on the mechanisms of mechanical-electrical transduction. The addition of TMZ (10(-6) or 10(-5) M) in the perilymphatic compartment counteracts the harmful effects of free radicals on the various bioelectric activities. These results suggest that the beneficial action of TMZ observed during treatment of cochleovestibular disorders is due, at least in part, to the anti-oxidizing properties of the molecule of interest.
Action Potentials↗
Determination of anti-cardiolipin and other antibodies in HIV-1-infected patients.
Anti-cardiolipin antibodies (ACA) were determined by an ELISA assay in 116 HIV-1-infected patients. A positive test was found in 27 patients (23.3%) with a predominance of IgG ACA isotype. No significant difference in ACA positivity was observed between homosexuals (22.2%) and intravenous drug users (25.8%). The presence of different immunological markers was compared in ACA-positive and ACA-negative patients: ACA-positive patients had higher IgG levels (p less than 0.05) and a tendency to higher frequencies of anti-ss DNA, anti-ds DNA, anti-i antibodies, as well as circulating immune complexes. When patients were classified according to CDC criteria, no significant difference was observed for the prevalence of ACA in class II (21.2%), in class III (25%), and in class IV (21%). Our results indicate that ACA antibodies occur with other immunological alterations in HIV-1-infected patients, but do not confirm that ACA is a useful prognostic marker for development of AIDS.
Adult↗
[Lipids, proteins and carbohydrates stimulate the secretion of intestinal cholecystokinin in the pig].
Food intake enhances the release of intestinal cholecystokinin (CCK) in the pig but the contribution of individual nutrients to the CCK response has not yet been established in this species. Six hogs (mean weight 50 kg) were fitted with a duodenal fistula for instillation of nutrients and with portal (PV) and carotid (CA) catheters for blood sampling. After a 24-h fast, the animals received 1,000 ml of isotonic solution containing 440 kcal of carbohydrate (starch hydrolysate), or of protein (casein hydrolysate) or fat (Intralipid) or a control saline solution by 60-min intraduodenal perfusion after a 60-min control period during which the animals received saline. Portal and peripheral blood samples were collected at 15-min intervals for CCK radioimmunoassay. Intraduodenal perfusion of fat provoked a sharp increase in CCK-Like immunoreactivity (CCK-LI) in PV (peak 76.6 +/- 12.2 pM from basal 10.8 +/- 1.2 pM) and in peripheral blood (peak 46.7 +/- 8.4 pM from basal 9.1 +/- 1.0 pM). The protein hydrolysate induced a transient increase in plasma CCK-LI during the first 30 min of intestinal perfusion (PV: peak 40.1 +/- 5.0 pM from basal 11.9 +/- 1.4 pM; CA: 31.8 +/- 4.0 pM from basal 8.5 +/- 0.8 pM). The transient effect of proteins on CCK release might reflect the consequence of somatostatin release from intestinal stores. Starch hydrolysate promptly raised plasma CCK-LI level to a plateau value (PV: 52.5 +/- 13.1 pM from basal 11.9 +/- 1.4 pM; CA: 35.4 +/- 8.0 from basal 8.5 +/- 0.8 pM).(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Effect of phenazine methosulfate on electrophysiological activity of the semicircular canal: antioxidant properties of trimetazidine.
Ischemia strokes appear to be the main source of cochleo-vestibular dysfunctions of peripheral origin. The present study aimed to investigate the action of oxygen free radicals on the bioelectric activity of the labyrinthine epithelium, using the frog semicircular canal as an in vitro preparation. We also examined the possible effect of the antianginal drug, trimetazidine (TMZ), under physiological conditions and during the administration of phenazine methosulfate (PMS). The model allows the ionic composition of endolymphatic and perilymphatic fluids bathing the semicircular canal to be dealt with separately. Spontaneous afferent vestibular nerve activity and the endolymphatic potential were recorded under resting conditions. Three additional parameters were investigated during mechanical displacement of the endolymphatic fluid: the ampullar direct current, the nerve direct current and the frequency of the evoked afferent spikes. Addition of TMZ (10(-6) and 10(-5) M, 50 min) into the perilymphatic compartment did not induce significant modifications of the different bioelectrical signals. Generation of oxygen free radicals, through administration of PMS (10(-5) M, 15 min) into the perilymphatic compartment, caused an impairment of all bioelectrical signals, except the ampullar direct current. The spontaneous activity, nerve direct current and frequency of afferent evoked spikes signals were significantly reduced 75 min after the start of PMS administration (-64, -17 and -32%, respectively). In contrast, there was a marked increase of the endolymphatic potential signal (+51%). Addition of TMZ (10(-6) or 10(-5) M) into the perilymph solution reversed the effect of PMS on all bioelectrical signals. These results indicate that TMZ acts as an antioxidant molecule which is capable of protecting the labyrinthine epithelium from the deleterious effect of oxygen radicals. Our data suggest that the protective effect of TMZ on ischemia-induced cochleo-vestibular dysfunctions may be accounted for by the antioxidant properties of this antianginal drug.
Animals↗
Androgen metabolites in bovine follicular fluid.
The values of C21-steroids, Delta4-androgens, estrogens as well as 5alpha-reduced steroids have been determined in follicular fluid obtained from superovulated and untreated cows. In the three cows treated with a hormone regimen to induce superovulation, the levels of progesterone and estradiol determined in 3 to 6 follicles per cow ranged from 65 to 448 ng/ml and 1.9 to 8.6 ng/ml, respectively while the concentrations of androstenedione and testosterone varied between 1.5 to 2.5 ng/ml. Low levels of dihydrotestosterone and androstane-3alpha, 17beta-diol (approximately 30 to 50% of Delta4-androgens) were found in the bovine follicular fluid. In untreated cows, the follicular steroid concentrations were divided into two groups on the basis of the ratio between estrogen and Delta4-androgen concentrations. In estrogen-rich follicles, the ratio of estrogens Delta4- androgens was higher than 1 and in estrogen-poor follicle, the ratio of estrogens Delta4- androgens was lower than 1. Pregnenolone, dehydroepiandrosterone, androst-5-ene-3beta, 17beta-diol, progesterone, androstenedione and testosterone levels were not significantly different in the two groups while the levels of estradiol and estrone were approximately 100-fold higher in the estrogen-rich group. The concentrations of 5alpha-reduced steroids particularly, dihydrotestosterone, androstane-3alpha, 17beta-diol and androsterone as well as their glucuronides which were found at values extremely low (under 1 ng/ml) were not significantly different in both groups. The results indicate that low levels of 5alpha-reduced steroids and their glucuronides are present in bovine follicular fluid and their concentrations remained fairly stable either in estrogen-rich or estrogen-poor groups.
Journal Article↗
Pharmacokinetics and organ catabolism of cholecystokinin octapeptide in pigs.
The pharmacokinetics and organ catabolism of cholecystokinin octapeptide (CCK8) were studied in pigs. In conscious animals, intravenous infusion of increasing doses of CCK8 (2.9-232.3 pmol.kg-1.min-1) resulted in a linear increase of plasma CCK-like immunoreactivity (CCK-LI). At the cessation of infusion of the largest dose of CCK8, plasma CCK-LI promptly returned to near basal values. The half-disappearance time (t1/2), metabolic clearance rate (MCR) and distribution volume (DV) were estimated to be 0.55 +/- 0.03 min, 134.8 +/- 10.8 ml.kg-1.min-1 and 107.9 +/- 13.0 ml.kg-1, respectively. In another group of anesthetized animals, infusion of CCK8 at similar doses produced higher plateau plasma CCK levels and the t1/2, MCR and DV were calculated to be 0.68 +/- 0.06 min, 32.5 +/- 3.9 ml.kg-1.min-1 and 45.2 +/- 5.6 ml.kg-1, respectively. Estimates of first-pass immunological degradation through various vascular beds were in the range 27-66%, with in decreasing order the kidney, liver, hindleg, followed by the brain and gut. These results indicate that immunoreactive CCK8 is rapidly cleared from plasma during passage through several vascular beds. The peptide is only partly inactivated during hepatic transit and so may exert hormonal effects upon its release from intestinal stores.
Animals↗
Reduction of blood transfusion requirement in open heart surgery by administration of high doses of aprotinin--preliminary results.
Reduction of homologous blood requirement in cardiac surgery is of increasing interest and may be achieved by various technical and pharmacological means. High-dose aprotinin (about 840 mg, equivalent to 6 million Kallikrein inactivator units), a serine proteinase inhibitor, was administered during open heart surgery to 60 patients refusing homologous blood transfusions or suspected to have an increased risk of bleeding. As a significant decrease in donor blood requirement could be observed, a prospective, randomised double blind study in 80 male patients undergoing primary coronary surgery with high-dose aprotinin administration was performed. Mean blood loss was reduced by 45.9% (652 ml in the treated vs 1204 ml in the untreated group, p less than 0.01) and the mean amount transfused was decreased by 74.2% (242 ml vs 937 ml, p less than 0.01). No homologous blood was needed in 57.9% of the aprotinin-treated patients and in 31.6% of patients not treated with aprotinin.
Aprotinin↗
Effects of cholecystokinin octapeptide on the pancreatic exocrine secretion in the pig.
In conscious pigs, intravenous infusion of serial doses of cholecystokinin octapeptide (CCK8; 2.9-232.3 pmol.kg-1.min-1) upon a background of secretin resulted in a linear increase of plasma CCK-like immunoreactivity (CCK-LI) concentration and evoked a dose-related increase of pancreatic volume and bicarbonate and protein outputs. The threshold plasma CCK-LI concentration for significant pancreatic response was 103.8 +/- 10.2 pM using a CCK8 dose of 8.8 pmol.kg-1.min-1. The maximum pancreatic response was observed for a plasma CCK-LI level of 498.0 +/- 15.3 pM using 77.2 pmol CCK8.kg-1.min-1. In anesthetized pigs, the threshold plasma CCK-LI concentration for pancreatic response was 1500 pM (actual CCK8 dose of 60.3 pmol.kg-1.min-1). The physiological relevance of this finding was assessed by comparing the food-induced increase of pancreatic secretion with that of plasma CCK-LI. Food ingestion was followed by a sharp pancreatic response and by a progressive increase of plasma CCK-LI to a peak increment of about 15 pM. Gel chromatography of portal and peripheral plasma from fed animals revealed three major peaks in the volumes of CCK33/39 and CCK8, and in a volume intermediate between CCK33/39 and CCK8. An additional minor component eluted ahead of CCK33/39. CCK8, which is one of the CCK components released after food intake, appears to be a fairly weak pancreatic stimulant in pigs.
Animals↗
Bombesin and nutrients stimulate release of CCK through distinct pathways in the rat.
An isolated, vascularly perfused duodenojejunum model was developed in the rat to investigate the mechanisms involved in the release of cholecystokinin (CCK) by vascular bombesin (BBS) and luminal nutrients (LN). Immunoreactive peptides released into the portal vein effluent were measured with three antisera that were relatively CCK specific, gastrin specific, and cross-reactive to both CCK and gastrin, respectively. Bombesin (10(-7) M) provoked a biphasic release of CCK, consisting of a transient rise (approximately 700% above basal) followed by a sustained response (approximately 250% above basal). Gastrin accounted for less than 25% of the total immunoreactivity as measured with the nonspecific antiserum. The two phases of the CCK response were related to the dose of BBS in the range 10(-10)-10(-6) M, with a half-maximal effect at 10(-8) M BBS. Tetrodotoxin (TTX, 10(-6) M) reduced the second phase only (by 80%), whereas hexamethonium (10(-4) M) and atropine (10(-5) M) left the two phases unaltered. LN induced a prompt and well-sustained release of CCK (approximately 250% above basal) that was not affected by arterial TTX or atropine. These results demonstrate that BBS stimulated the release of CCK through both a direct pathway and an indirect, noncholinergic mechanism, while the effect of LN did not appear to involve intramural nerves.
Animals↗
Sodium transfer from endolymph through a luminal amiloride-sensitive channel.
An in vitro preparation of frog semicircular canal was devised to study the mechanisms of Na transport across the labyrinthine epithelium. When the lumen of the semicircular canal was filled with perilymph-like solution, the structure was able to secrete K into and to absorb Na from the lumen and to generate a lumen-positive transepithelial potential. When the lumen of the semicircular canal was filled with endolymph-like solution, the electrochemical composition of the luminal fluid was partly maintained up to 2 h. In this last experimental condition net and unidirectional fluxes were calculated in absence or presence of transport inhibitors, separately for the ampulla and for the nonampullar part of the canal. Amiloride (10(-5) M) but not dimethyl amiloride (10(-5) M) inhibited 60% of the unidirectional Na efflux out of endolymph; this Na efflux decrease resulted in an increase of the inward net Na flux. The net Na flux was also increased after abluminal application of ouabain (10(-3) M), furosemide (10(-4) M), and bumetanide (10(-6) M). This study validates this isolated preparation as a suitable tool for the study of endolymph secretion, confirms that the secretion of endolymph is achieved in the ampulla, and provides evidence for an apical amiloride-sensitive Na channel through which Na is transferred out of endolymph along an electrochemical gradient provided by the activity of the abluminal Na+-K+-ATPase.
Amiloride↗
Biplane fracture of Tillaux.
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Adolescent↗
The non-ionic contrast media: thrombosis or haemorrhage?
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Contrast Media↗
[Tillaux's fracture].
Tillaux fracture or fracture of the antero-lateral portion of the distal tibia has a vertical fracture line either at the middle of the epiphysis or close to the external malleolus. It is seen around 13-14 years. Distance from the fracture line to the external malleolus depends of the degree of closure of the epiphyseal plate. When the medial aspect of the physis is open, the fracture line is more medial. The location of the fracture line in the epiphysis therefore depends on the maturity of the physis as shown by closure of its medial portion. Tomography is frequently necessary to see the fracture line and mainly to appreciate the fracture gap. If the gap is less than two millimeters non operative treatment with plaster cast is sufficient.
Adolescent↗
[Current aspects of sinus barotrauma. The impact on treatment, prevention and fitness].
Among the barotraumatism which affects divers and airplane pilots, sinus barotraumatism is one of the less known and studied, as the scarceness of series published can testify. The interest of this study stands in doing an up to date synthesis (recap) of the bibliography, and to understand the "physio-pathologic" mechanism after the exploitation of series of 22 observations. That work will allow a better knowledge of therapeutic on the one hand, and of the "prophylactic" on the other hand.
Aerospace Medicine↗
Lattice calculation of weak amplitudes of D and B mesons.
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Journal Article↗