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Biomedical subjects

P Arhan

Publications and source records attributed to P Arhan.

At least 37 records · Page 2Linked to original sources
PubMed1996

Determination of metallothioneins by HPLC: application to zinc metabolism.

Metallothioneins (MT) are well known Zn and Cu tissue proteins. Their level is mainly regulated by Zn. Therefore, they have been suggested as an index of Zn status. The determination of MT has been performed by HPLC (fitted with UV-detector) following a preparation phase (heating, ultracentrifugation and filtration). This method allows direct quantification of MT in tissues and shows a good correlation between MT concentrations and peak heights (r2 = 0.995; a = 774.73; b = -148.38) from 0 to 10 micrograms/100 microL. MT determination by RP-HPLC method allows to assess the tissue zinc status as displayed by the correlation between hepatic zinc and metallothionein concentrations (r2 = 0.82; p < 0.001). Variations of MT in response to Zn intakes are observed within 24 hours and for a physiological range of dietary Zn intakes.

Chromatography, High Pressure Liquid↗
PubMed1995

A mathematical analysis of intestinal peristaltic waves.

Gut motility is usually investigated by introducing probes in the intestinal lumen. Image analysis could be used instead of intraluminal pressure measurements to avoid the inconvenience of this invasive procedure. The present study exposes the theoretical principles of intestinal peristalsis in terms of indirect intraluminal pressure and content velocity measurements. A geometrical model of intestinal contractions is mathematically described by using Stokes' equations in order to evaluate velocities and pressures in the equations established by quantitative analysis of cinematography pictures. The couple velocity-pressure is calculated at each point of the geometrical model for a viscous and non-compressible fluid. This fluid flows in a geometrical structure, the boundaries of which vary with time and behave in a periodic and regular way by simulating the movements of intestinal contractions. A comparison is made between experimental pressure recordings in isolated rat intestines and pressure values calculated by utilizing the geometrical model. Velocity values calculated at every grid node show positive and negative zones in the geometrical model output. The position of these zones vary from one geometrical model to another. Moreover, the calculated pressure and velocity values change according to the applied vector efforts. The similarity of the results obtained shows the efficiency of the finite element technique in the case of Stokes' equations.

Animals↗
PubMed1995

Compartmental analysis of colonic transit reveals abnormalities in constipated patients with normal transit.

1. The aims of this study were to investigate if compartmental analysis can be used to analyse colonic transit measurements and to search for a relationship between transit time and the parameters deduced from this analysis. In addition, an attempt was made to determine if such analysis could reveal a functional abnormality in patients who complain of constipation but have normal colonic transit. 2. The subjects included 11 healthy controls, 10 patients with chronic diarrhoea and 55 constipated patients. Segmental and total colonic transit time were measured using a previously described method. Compartmental analysis was based on a three-compartment system, with k1, k2 and k3 being the coefficients of diffusion out of the right colon, the left colon and the rectosigmoid area respectively. 3. Patients complaining of constipation who had delayed transit time were the only subjects to have lower values of coefficient k1 than controls. k2 was lower than normal in all patients complaining of constipation, but this decrease was more marked in subjects with delayed colonic transit time than in subjects with normal colonic transit time. All patients complaining of constipation had lower values of k3 than control subjects. 4. This study shows that analysis of colonic transit time is feasible using a simple diffusion law, and that the results are correlated to clinical data. Moreover, this analysis permits detection of abnormalities in two groups of subjects: those who complain of constipation but are labelled as having normal colonic transit time and those who have chronic diarrhoea.

Adult↗
PubMed1995

Colonic transit in soccer players.

To evaluate the effects of exercise on colonic function, we measured total and segmental transit times in 11 male soccer players and nine male radiology student technicians. Diet was kept constant in all subjects, who maintained their normal activities. For the soccer players, normal activities included 15 h of training and one match each week. Transit times were measured with radioopaque markers, using the multiple-ingestion, single-radiograph technique. No overall difference in large bowel transit was observed between the two groups. Right colon transit was considerably slower in the soccer players, whereas left colon and rectal transit were slightly accelerated. We conclude that an intensive sport activity only modifies regional differences in large bowel function. This may be of importance in extreme conditions, such as those experienced by marathon runners. Data should be obtained before prescribing exercise to treat constipation.

Adult↗
PubMed1994

Biofeedback re-education of faecal continence in children.

The purpose of this prospective study was to see if pretreatment anorectal motility can predict successful correction of faecal incontinence with biofeedback. Forty-seven consecutive children, aged 5 to 18 years, were treated. They had been treated for idiopathic constipation with faecal impaction, but had remained incontinent (n = 15), had been operated for congenital anorectal malformations of high (n = 19) or low (n = 2) type, or had a number of organic congenital pelvic abnormalities (n = 11). This consecutive series represents our entire experience with biofeedback for faecal incontinence, in the period from January 1 1983 to December 31 1989. In each patient, at the first session, anorectal manometry was performed. Resting pressures in the rectum, upper anal canal and lower anal canal were measured. The threshold of rectal sensation during distension, the maximal pressure during voluntary sphincteric contraction and the time to half decrease of sphincteric pressure because of muscular fatigue were also noted. The patient was then asked to make a voluntary sphincteric contraction, while the rectum was being distended with the volume at threshold for rectal sensation. In subsequent sessions, the rectum was also distended but without warning the patient, who was congratulated when he or she contracted the sphincter immediately after onset of rectal distension. Full continence was the criterion used to classify re-education as a success. Improvement or no change in continence was considered as failure of the treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Motility of the transplanted small bowel: a manometric study in the piglet.

Complete transection of sympathic and parasympathic nerves is an inevitable consequence of intestinal transplantation. The aim of this experiment was to study if extrinsic denervation alters the motor function of the graft. Ten large-white piglets were used. In Group 1 control (5 animals), a segment of distal ileum was isolated on its intact neurovascular pedicle as a Thirty-Vella loop. In Group 2 study (5 animals), a Thiry-Vella loop of distal ileum was transplanted as a free autograft. The motility of intestinal loops was studied by intraluminal pressure recording at the 8th and 15th postoperative days, on conscious animals fasted for 24 hours. The measured patterns were period (P), duration (D), maximal amplitude (A) and speed of migration (S) of phases III of migratory myoelectric complexes (MMCs). One hundred and seven MMCs were recorded and compared between Group 1 and Group 2. The results were as follows: mean (+/- sem) of Group 1 vs mean (+/- sem) of Group 2. P (min) = 68.5 (+/- 8.1) vs 54.2 (+/- 3.2)(NS); D (min) = 5.9 (+/- 0.2) vs 5.9 (+/- 0.1) (NS); A (cmH2O) = 73.9 (+/- 4.1) vs 83.4 (+/- 3.2) (NS); S (cm/min) = 5 (+/- 1.1) vs 6.2 (+/- 1) (NS). The motor function of the loops was studied following intraluminal perfusion of a cholinergic compound (carbachol) at doses of 1, 2, 3, 4 and 5 mg. The mean and the maximal pressures were recorded during 3 minutes from the 2nd minute following injection of carbachol.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

[Physiological variations of LpA1, HDL2 and principal lipid markers in athletes].

An original approach of the influence of physical activities on lipid metabolism is presented in this work: the authors studied the physiological variations of the lipoparticle LpA1, high-density lipoprotein subfraction HDL2 and the most important lipid markers in serum of a presumably healthy population of 55 high-level sportsmen. They were 18-45 years old and practised endurance sports, whether individual (cycling, long-distance running), or collective activities (soccer, basketball). The authors observed an important increase of LpA1 (+20%, p < 0.001) and C-HDL2 (+23.3%, p < 0.01) after an intense physical activity (CK = 430 +/- 312 U/l); they also found a good correlation between LpA1 and HDL2 (r = 0.85, p < 0.0001) and between LpA1 and CK (r = 0.62, p < 0.001).

Adolescent↗
PubMed1994

Variation of rheological properties of the human rectal wall with distending volume.

Pressure-relaxation curves of in vivo human rectal wall were studied in 30 normal children for 5 volumes of distension, 10-50 ml, to define the conditions of application of the quasi-linear viscoelastic law. Three normalization methods were compared: the use of the maximum pressure of the curve, the use of the first measured point after the rectal distension, and the use of the passive state defined as the inferior envelope of the experimental curve. Analysis of variance with repeated measures was used for data analysis. It was shown that: i) the first relaxation curve, corresponding to a 10-ml distension volume, was significantly different from the other curves (p < 0.0001); ii) the quasi-linear viscoelastic law could be applied to the in vivo determination of the mechanical properties of the rectal wall, when considering the mean level of the measured points; and iii) the shapes of the experimental curves at different level of distension were significantly different (p < 0.0001). We conclude that the hypothesis of quasi-linearity is appropriate, in a first approximation, as a model of rheological properties of the rectal wall.

Adolescent↗
PubMed1992

Ureterorectal diversion with rectal augmentation. Morphological and manometric study in the dog.

Uretersigmoidostomy in the adult has progressively been abandoned because of its high complication rate (both metabolic and functional). We have studied the feasibility of a new model of ureterorectal diversion in 12 Beagle dogs, with the aim of increasing rectal capacity and decreasing rectal pressure. A segment of the ileum was isolated and opened along its antimesenteric border to obtain a patch into which the right ureter was implanted, the left ureter being left intact to allow comparison of the kidneys postoperatively. The patch was then sutured to the edges of a large anterior rectotomy. Modifications of rectal physiology were studied by recording the rectal pressure after distension by a latex balloon both preoperatively and 3 months postoperatively, so that it was possible to evaluate the elasticity of the rectal wall. Radiographic studies and examination of autopsy specimens after 3 months yielded the impression of a reservoir added to the rectal space. Intrarectal pressure was significantly decreased (50% of the preoperative value) for a given distension volume following rectal augmentation (P less than 0.01). The elasticity of the rectal wall was not modified but the capacity of the reservoir was increased. The ureteroileal implantation was patent in two of the five evaluable dogs out of seven implantations performed. In these cases, signs of pyelonephritis were found in the right kidneys. In the remaining cases the implantation became obstructed for reasons mainly related to canine anatomy and experimental conditions. These technical difficulties in the dog make it impossible to assess the quality of this reimplantation technique in this model.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
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↗
PubMed1991

Achalasia of the esophagus in childhood. Surgical treatment in 35 cases, with special reference to familial cases and glucocorticoid deficiency association.

Achalasia of the esophagus is a relatively rare problem in children, but it may be the cause of severe lung disease, growth retardation and respiratory death in young infants. Surgical esophago-cardio-myotomy remains the treatment of choice, and this article details 25 years of experience with 35 children with achalasia of the esophagus and their late post-operative follow-up. The occurrence of achalasia in the first six months of life, the existence of a familial factor, the prevalent possible association with genetic diseases (familial dysautonomia, glucocorticoid insufficiency, Rozycki syndrome) suggest that achalasia in childhood may in certain cases represent a congenital problem, somewhat different from the adult form, which is considered to be an acquired disease.

Child↗
PubMed1990

[Irritable bowel syndrome in children].

In the adult, the irritable bowel syndrome is characterized by intestinal transit disorders associated or not with chronic abdominal pain. Two different forms can be seen: in one, pain and constipation are predominant, while in the other, pain and diarrhea alternate. The second form is encountered with predilection in the child. Various terms can be used to name the syndrome including colitis, non specific or benign colitis, irritable bowel syndrome in the child, infantile diarrhea, and others, all of which attests to our ignorance of the pathophysiology of this disorder. This syndrome is by far the most frequent cause of chronic or recurrent diarrhea in the child. Before the age of 3 or 4 years, the principal syndrome is diarrhea, which usually appears before the age of 6 months. Onset is generally brutal, as in acute enteritis or an extradigestive infection (ENT...) but persists, or else, more often, the syndrome appears insidiously over several days. The child has soft or liquid stools of fetid odor in most cases, very rarely sourish, inhomogeneous and in which intact aliments can be found. Stools are often associated with mucous discharge, rarely with blood, and do not contain any pus. Stools are not fatty but occasionally they are sticky and adhere to the pot. During the day, stools change from well formed in the morning to soft in the evening. Their frequency varies from one day to another as well as during a given 24 hour period, ranging from one or two to 10 per day.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1989

Idiopathic constipation by colonic dysfunction. Relationship with personality and anxiety.

The personality of two groups of constipated women (by delayed colonic transit or by colonic inertia) was compared to that of two control groups of arthritic patients (rheumatoid or degenerative disease) with the Minnesota Multiphasic Personality Inventory (MMPI). All subjects suffered from chronic pain. Constipated women were found to have significantly higher scores on the hypochondria, hysteria, control, and low back pain scales and a lower score on the masculinity-femininity scale. Discriminant analysis permitted us to sort out constipated from arthritic patients in 83% of the cases, on the basis of only the personality data. In women with constipation by delayed colonic transit, multiple regression analysis demonstrated a close link (r = 0.90; P less than 0.001) between transit time in the ascending colon and levels of anxiety. It is concluded that women with constipation of colonic origin have a different pattern of personality than arthritic women and that severe constipation may play the role of a defense mechanism, where psychophysiologic responses to life stresses replace normal emotional reactions.

Adolescent↗
PubMed1989

Functional evaluation of gastric transplants used in esophageal reconstruction.

Gastric transplants using the Akiyama method were used to treat esophageal carcinoma in 12 patients. Endoscopic examination, prolonged manometry (greater than 30 min), and 24 h pH monitoring were performed postoperatively to evaluate functional results. All patients could swallow without difficulty at the time of examination and had no dysphagia, regurgitation, heartburn, or sensation of abdominal fullness. Histologic examinations of residual esophagus showed microscopic esophagitis in 5 patients. Percentage of time that pH less than 4 was 42.6 +/- 10.9% (mean +/- SEM) and median pH was 4.3 +/- 1.0. The manometric examination showed no 'esophageal-like' peristaltic waves, but synchronous contractions were demonstrated in 9 patients, gastric type activity in two patients, and no activity was detected in one patient. We conclude that retained gastric peristaltic function is not a prerequisite for a good clinical outcome for swallowing and that despite vagotomy, the stomach continues to produce enough acid to maintain an acidic pH.

Aged↗
PubMed1989

Morphology and rheology of the rectum in patients with chronic idiopathic constipation.

To evaluate whether there is a relationship between the viscoelastic properties of the rectum and its surface, barium enema and rectal accommodation studies were performed under standard conditions in 46 subjects (25 adults, 21 children) with chronic idiopathic constipation. In adults, a significant correlation was found between rectal surface at barium enema and the minimum radius of rectal distention with a balloon necessary to higher wall tension changes (r = 0.68; P less than 0.01). In both adults (r = 0.48; P less than 0.05) and children (r = 0.57; P less than 0.01), negative correlations were found between the surface of the rectum and its elasticity. It is concluded that rectal accommodation studies produce data comparable to those of radiologic examinations and may therefore be used repetitively, and without fear of radiation, as follow-up studies on constipated patients.

Adult↗
PubMed1989

Achalasia of the esophagus in childhood: surgical treatment in 35 cases with special reference to familial cases and glucocorticoid deficiency association.

Achalasia of the esophagus is a relatively rare problem in children, but it can result in severe lung disease, growth retardation, or respiratory death in young infants. Surgical esophagocardiomyotomy remains the treatment of choice, and this report details a 25-year experience with 35 children with achalasia of the esophagus and their long-term postoperative follow-up. Occurrence of achalasia in the first 6 months of life, the existence of familial cases, and the association of achalasia with genetic diseases (familial dysautonomia, glucocorticoid insufficiency, Rozycki syndrome) suggest that achalasia in childhood may in certain cases represent a congenital problem.

Adolescent↗