PubMed Health⌕ Search

Biomedical subjects

P Denis

Publications and source records attributed to P Denis.

At least 19 recordsLinked to original sources
PubMed1992

Retinal dopaminergic receptor affinity and ocular pharmacokinetic profile of piribedil.

Binding studies on retinal dopamine receptors have revealed the existence of both D1 and D2 receptors. Human retina micro-autoradiographs confirm the distribution of dopaminergic receptors in the plexiform layers. Piribedil, a dopaminergic agonist, is able to bind to D2 receptors, while its metabolite (S584) preferentially displaces D1-specific radioligands. These results demonstrate that piribedil has a dopamine-like pharmacological profile including direct interaction with receptors. When instilled into the rabbit eye, piribedil penetrates rapidly and accumulates in the pigmented epithelia--the iris ciliary body and chorioretina--before being rapidly cleared. Macro-autoradiographs confirm this distribution and show the levels to be compatible with the affinity of piribedil for retinal dopaminergic receptors.

Animals↗
PubMed1992

Relationship between clinical symptoms of anal incontinence and the results of anorectal manometry.

The aim of this work was to analyze clinical symptoms in light of anorectal manometry results. We compared the frequency of clinical symptoms in relation with the presence or absence of functional anomalies. Using this methodology, the following relationships may be suggested: the need to wear a pad, with a decreased resting pressure at the upper part of the anal canal; the inability to delay rectal evacuation, with decreased anal voluntary contraction; interference of incontinence with social activities, with decreased duration of anal voluntary contraction; urinary symptoms, with an increased threshold volume of rectal distention needed to elicit the rectoanal inhibitory reflex; and complete rectal prolapse, with reduced length of the anal canal.

Adult↗
PubMed1992

What is the meaning of colorectal transit time measurement?

This study was done to understand the different available methods used to calculate colorectal transit times. A single abdominal radiograph is taken following six successive daily ingestions of the same number of identical radiopaque markers. This method correlates well (P less than 0.001) with that using a single ingestion of markers with daily x-ray films until total expulsion. In techniques used to measure colorectal transit time with multiple ingestion of markers, the number of days of ingestion depends on the kinetics of marker defecation. This was found to differ markedly in various groups of control subjects and constipated patients (P less than 0.001) and can be used to obtain reliable data, even in subjects with severe constipation. When they ingest 20 markers, constipated patients are found to retain eight or more markers three days after ingestion, and taking a plain film of the abdomen on that day is sufficient to make a diagnosis of constipation. Transit time studies are reproducible from month to month in patients with an irritable bowel syndrome. Control subjects who claim that their bowel habits are not modified by stress have shorter transit times, similar in both sexes, than those who say they are (P less than 0.001). This may explain why a large percentage of constipated patients have been found by most authors to have "normal" colorectal transit times. The choice of control subjects is thus a key element in studies of functional bowel motor disorders. Stool frequency and consistency, in health, correlate only to rectosigmoid transit time.

Adult↗
PubMed1992

[Prevalence of anal incontinence in adults].

Inquiries were conducted to determine the prevalence of anal incontinence in a) the general population over 45 by a gallup poll studying 1,100 persons (A); b) 3,914 patients seen by their general practitioner or their gastroenterologist during the same week (B); c) 500 patients consulting for urinary stress incontinence (C1); d) 1,136 neurological patients suffering from micturation disorders (C2); and e) 10,157 elderly persons living in retirement homes or in hospital (D). In the general community (A), the prevalence of anal incontinence, including gas and stool incontinence, was 11 percent, the prevalence of fecal incontinence, 6 percent, the prevalence of daily or weekly fecal incontinence, 2 percent; prevalences were respectively 15.5 percent, 7.9 percent, and 3.2 percent in group B, and 27 percent, 9 percent and 3.8 percent in group C1. The prevalence of fecal incontinence was 18 percent in group C2 and 33 percent in group D. Prevalence did not depend on age in group A and C1, but was twofold higher in group C1 than in group A. The prevalence increased with age in groups B and D.

Adult↗
PubMed1992

Effect of an effervescent citrate-cimetidine combination on intragastric pH in healthy subjects. A randomized, placebo-controlled three-period cross-over design.

Twelve healthy male volunteers participated in a randomized placebo-controlled, three-period cross-over study to assess the effect of a new effervescent citrate-cimetidine combination (200 mg cimetidine/tablet) (C) on intragastric pH in comparison with a liquid aluminium-magnesium hydroxide antacid (A) and placebo (P). The intragastric pH values were determined by an Ingold combined glass electrode and recorded by a "pH 60" portable unit. Each pH-metry lasted 5 hours and was performed on three separate occasions at one-week intervals. Each treatment was orally administrated at 09.00 h, following a 1-hour baseline intragastric pH recording. The effect of C was measurable almost immediately after drug intake with a median pH between 5-6.5 within 3 minutes, lasting for a mean of 110 minutes and median pH greater than 4 for at least 4 hours. The rise of gastric pH with C was higher (P less than 0.01) and longer (P less than 0.01) than that of A: median pH between 3.5 and 4.5 for 10 to 35 minutes, pH above the placebo curve for 140 minutes and above pH 3 for 50 minutes. In terms of percentage of time at or above each pH level, the differences between the three treatment groups were significantly in favor of C compared to A and A compared to P.

Adult↗
PubMed1992

Depression and fixations.

The concept of fixation occupies an important position in psychoanalytic theory. The mechanism of fixations cannot be explained solely by means of the notions of regression and repetition. On the basis of a theory of depression in which depression is seen as the outcome of a fetishistic cathexis of the 'shadow of the object' set up in the ego as a 'depressive object', the author postulates that fixations become organized during the depressive movements of childhood.

Depression↗
PubMed1991

External anal sphincter function in spinal patients. Electromyographic and manometric study.

Six patients with complete transection of the spinal cord and six healthy volunteers were examined by using anorectal manometry together with electromyographic (EMG) recording of the external anal sphincter composed of striated muscle. Anal pressure and EMG activity of the external anal sphincter were continuously recorded at rest and during gradual rectal distention (10, 20, 30, 40, and 50 ml) by means of an air-filled balloon eliciting a rectoanal inhibitory reflex (RAIR) at the upper part, and an inflation reflex (IR) at the lower part of the anal canal. All patients and controls had a RAIR for each rectal distention volume. A relationship between the duration of the RAIR and the rectal distention volume was present in controls only. In controls the IR was present for each rectal distention volume, whereas it was present in only one patient for a 40-ml volume. During the resting period, all controls showed continuous tonic EMG activity of the external anal sphincter, but after 30 minutes all the patients showed a decrease and ultimately in five cases a disappearance of the tonic EMG activity of the external anal sphincter. In spinal patients, the presence or absence of EMG activity of the external anal sphincter did not modify the anal canal pressure. These results indicate that: 1) the tonic EMG activity of the external anal sphincter seems to be under the control of supraspinal structures, because in spinal patients it disappears in the absence of sensitive inputs toward the spinal cord; 2) the absence of EMG activity at rest indicates that the external anal sphincter is not implicated in the RAIR disturbances observed in spinal patients; 3) the IR is not a spinal reflex but is under voluntary control, because it is not present in spinal humans; 4) in spinal humans the tonic EMG activity of the external anal sphincter does not play a role in the maintenance of the anal pressure at rest.

Adolescent↗
PubMed1991

Autoradiographic characterization and localization of vasoactive intestinal peptide binding sites in albino rat and rabbit eyes.

Localization and pharmacological properties of vasoactive intestinal peptide (VIP) binding sites were investigated in eyes from albino rabbits and rats using an in vitro autoradiographic method. [125I]VIP was used as ligand, and various unlabelled peptides were studied to test the specificity of binding. Autoradiograms were generated by apposing 20-microns-thick cryostat eye sections to [3H]Hyperfilm or autoradiographic emulsion and quantified by means of image analysis procedures. Specific binding represented about 85% of total binding. Kinetic studies showed that equilibrium was reached after a 120-min incubation at room temperature. Biochemical investigations demonstrated that [125I-]VIP bound to a population of sites with high affinity (Kd = 2.27 +/- 0.25 nM). Inhibition of [125I]VIP binding with VIP and related peptides indicated the following rank order of potency: VIP greater than Peptide histidine isoleucine greater than secretin greater than human growth hormone-releasing factor, glucagon, VIP1-14, VIP14-28. In both species, specific binding was found in conjunctiva, iris, ciliary processes, choroid and retina. Moderate grain densities of VIP binding sites were also present in the rat cornea. Quantitative analysis of the autoradiograms revealed that the highest densities of [125I]VIP binding sites were located in the iris and ciliary epithelia in rabbits and in the inner retina in rats. Our findings suggest that VIP may play an important role in several ocular functions, especially in aqueous humor dynamics and retinal neuromodulation.

Animals↗
PubMed1991

Liver glutathione and cytochrome P450 activity in experimental infection: study of the relative effects of infectious stress and malnutrition.

OBJECTIVE: To study the effects of infection and malnutrition on liver glutathione and cytochrome P450 (P450) in rats. DESIGN: Controlled experimental groups (12 groups). ANIMALS: Adult male Sprague-Dawley rats. INTERVENTIONS: Experimental endocarditis, pyelonephritis, or peritonitis were caused. Controls included free-fed rats and sham-operated rats, pair-fed to infected animals. Infection was verified by tissue culture. Rats were killed 3 days (acute infection) or 10 days (chronic infection, except endocarditis) after the induction of infection. RESULTS: Sham rats had lower liver weights, liver/body weight, and liver glutathione values than controls. Infected rats had larger liver weights and liver/body weight ratios and liver glutathione content than shams, and larger liver/body weight ratios than controls (acute infection). Infected rats had lower P450 values than both shams and controls. CONCLUSION: The malnutrition associated with infection caused decreased liver weight and glutathione content. Infection increased the liver weight, and liver glutathione content, but caused severe reduction in liver P450. If the same finding is true in infected patients, it could have consequences for the management of such patients.

Animals↗
PubMed1991

Effects of amoxicillin-clavulanate combination on the motility of the small intestine in human beings.

The amoxicillin-clavulanate combination (Augmentin) frequently induces gastric complaints and diarrhea by an unknown mechanism. The aim of this study was to assess the effects of two orally therapeutic regimens of amoxicillin-clavulanate on small bowel motility in human beings. Duodeno-jejunal manometric recordings were performed in six healthy subjects treated in a cross-over double-blind study with placebo; amoxicillin-clavulanate, 1 g plus 250 mg per os every 12 h for 3 days; or amoxicillin-clavulanate, 1 g plus 250 mg per os every 12 h on day 3 only (1-day regimen). Recordings were all performed on day 3 during a diurnal fasting period, a fed state after a standard dinner, and a nocturnal fasting period. Amoxicillin-clavulanate did not affect the motility of the small intestine during the diurnal fast or the fed state. During the nocturnal fast, amoxicillin-clavulanate significantly increased the motility index of the nonpropagated contractions and tended to increase the duration and the amplitude of the propagated contractions. The same digestive motor effect was already observed on the first day of treatment (1-day regimen). This study demonstrates that the oral administration of a therapeutic regimen of amoxicillin-clavulanate is associated, in most cases, with the occurrence of small intestinal motor disturbances.

Adult↗
PubMed1991

Localization and characterization of substance P binding sites in rat and rabbit eyes.

Specific and high-affinity binding sites for Substance P (SP) were found in eyes from albino rabbits and rats using an in vitro autoradiographic method with 125I-Bolton Hunter SP (BHSP). autoradiograms were generated by apposing 10-20 microns-thick cryostat eye sections to 3H-Hyperfilm or liquid emulsion and quantified by means of image-analysis procedures. Kinetic studies showed that equilibrium was reached after a 75-min incubation at room temperature. In rat retina, specific binding corresponding to approximately 90% of total binding, was reversible, of high affinity (dissociation constant [Kd], 0.13 +/- 0.02 nM). Half-time for dissociation of 125I-BHSP was about 15 min. Unlabeled SP and the two neurokinins (NK) A and B competed in a concentration-dependent manner for retinal sites labeled by 125I-BHSP with the following order of potencies: SP greater than NKA greater than NKB, in agreement with a pharmacologic profile of a SP receptor site. In both species, specific binding was found in the iris sphincter muscle, choroid, and retina. In rats, detectable amounts of SP-binding sites were also expressed in the corneal epithelium and iridial stroma. Quantitative analysis of the autoradiograms revealed that the highest densities of 125I-BHSP binding sites were localized in the iris sphincter muscle in rabbits and the inner retina in rats.

Animals↗
PubMed1991

Could recurrent cholangitis after Roux-en-Y hepaticojejunostomy be explained by motor intestinal anomalies? A manometric study.

The aim of this study was to describe the motor patterns found in two patients with recurrent cholangitis episodes after Roux-en-Y hepaticojejunostomy. In one patient, cholangitis was due to a stenosis of the anastomosis between the limb and the left intrahepatic bile duct, while motility of the limb, duodenum, and distal jejunum was normal. In the second patient, no anatomical explanation was found for cholangitis attacks. However, although the duodenal motor activity was normal, the motility of the limb and of the jejunum below the jejunojejunal anastomosis was grossly abnormal: permanent minute rhythm, phase IIIs absent or rare and slowly propagated, all motor abnormalities that could promote bacterial overgrowth in the limb. This stresses the interest in performing motor studies of the Roux-limb when cholangitis remains unexplained after Roux-en-Y hepaticojejunostomy.

Anastomosis, Roux-en-Y↗
PubMed1991

[Collis's operation for brachyesophagus. (49 patients)].

The results of infradiaphragmatic Collis' gastroplasty for the treatment of gastroesophageal reflux associated with acquired short brachyesophagus (Barrett's esophagus) were prospectively studied in 49 patients (50 operations). Clinical and endoscopic findings, and 3-hour postprandial pH measurement including Kaye's score were evaluated at short (3 to 8 months), medium (1 to 4 years), and long-term (more than 4 years) for all patients. Postoperative morbidity was 16 percent; there were 3 deaths (6 percent). Short term results, evaluated in 45 patients, were considered satisfactory in 30, poor (pyrosis and esophagitis) in 2, and incomplete (pyrosis without esophagitis in 2, dysphagia in 5, mild esophagitis in 6) in 13. Long term results (32 patients) were satisfactory in 24, poor in 5, and incomplete in 3 (pyrosis without esophagitis in one, gastric outlet disorder in 2). Long term pH measurements were obtained in 21 patients: 3 out of 6 patients with high scores had clinical or endoscopic signs of esophagitis. Analysis of late results showed that: a) satisfactory short term outcome was maintained in all but 2 patients (deterioration was observed in one patient 4 years later because of aggressive treatment for terminal bronchopulmonary carcinoma; the other was observed 5 years later after steroid therapy for aspergilloma with severe asthma); b) pH scores were variable in 11 patients. This variability and discordance of pH measurements was most likely due to the presence of acid secretion above the new esogastric junction, which was observed in half of the cases. We conclude that Collis' gastroplasty provided good results in Barrett's esophagus and might be compared to duodenal diversion in ulterior studies in this setting.

Adolescent↗