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Biomedical subjects

F Barbier

Publications and source records attributed to F Barbier.

At least 19 recordsLinked to original sources
PubMed2002

Main functional roles of knee flexors/extensors in able-bodied gait using principal component analysis (I).

This study was undertaken to demonstrate how principal component analysis (PCA) can be used to detect the main functional structure of actions taken by knee flexors/extensors during able-bodied gait. PCA was applied as a classification and curve structure detection method for knee sagittal muscle moment developed during walking of 20 young, healthy male subjects. Over 90% of the information provided by the first three principal components (PCs) was chosen for further biomechanical interpretation. PCA was able to identify the three main functional contributions of knee sagittal muscle moment during able-bodied gait, namely control balance, foot clearance/limb preparation and shock absorption.

Adolescent↗
PubMed2000

Gait pattern classification of healthy elderly men based on biomechanical data.

OBJECTIVES: To distinguish the gait patterns of young subjects from those of elderly men using three-dimensional (3D) gait data, to determine if elderly subjects displayed other than a typical gait pattern, and to identify which parameters best describe them. DESIGN: Nonrandomized study in which video and force plate data were collected at the subject's own free walking speed and used in a 3D inverse dynamic model. Cluster analysis was chosen to identify the gait families, and analyses of variance were performed to determine which parameters were different. SETTING: A gait laboratory. PARTICIPANTS: The sample of convenience involved a single but mixed group consisting of 16 able-bodied elderly subjects (mean age, 62yrs) and 16 able-bodied young subjects aged between 20 and 35 years. MAIN OUTCOME MEASURES: Phasic and temporal gait parameters, as well as the 3D muscle powers developed in the joints of the right lower limb during the gait cycle. RESULTS: The walking patterns in elderly subjects were found to be different from those of the young adults. Three elderly gait families or groups forming a specific gait pattern were identified, and differences were found in the phasic and temporal parameters as well as in 6 peak muscle powers. Four of the peak powers occurred in the sagittal plane, and half of them were related to the hip. CONCLUSIONS: Biomechanical parameters can be used to classify the gait patterns of young and elderly men using cluster analysis rather than age alone. The muscle powers in elderly subjects are perturbed throughout the gait cycle and not only at push-off. It appears that the plane in which the peak powers occurred was related to their occurrence in the gait cycle. Variability in the gait patterns of elderly subjects could reflect natural adaptations or compensations. These should not be indicative of a deficient gait or be misconstrued as some age-related pathology.

Adult↗
PubMed1998

Multivariate graphical presentation for gait rehabilitation study.

This paper describes a procedure to determine the progress of the gait rehabilitation in relation to a reference obtained from a normal population. This procedure includes three stages: (1) data standardization, to give time and space aspects comparable from one individual to another; (2) monovariate and multivariate distance computation, to assess the difference between a disabled patient at a given time in the rehabilitation and the reference computed from individuals with a 'normal' gait; and (3) distance evolution. Since several variables are taken into account at the same time, the star view is proposed, each ray corresponding to the average distance between a given function of the patient undergoing rehabilitation and the corresponding reference function. Thus, as the rehabilitation process progresses, the distances are reduced and the star ray decreases. As a case study, the procedure is applied to the rehabilitation of a patient with an anterior cruciate deficient knee. Copyright 1998 Elsevier Science B.V.

Journal Article↗
PubMed1998

Benzene exposure in car mechanics and road tanker drivers.

The purpose of this study was to identify professional factors related to benzene exposure and to deduce suitable safety measures. Atmospheric benzene, urinary muconic acid (tt-MA) and leukocyte alkaline phosphatase activity (LAPA) were evaluated among 66 car mechanics, 34 road tanker drivers, and 28 nonexposed workers. Professional and medical questionnaires were filled in at the same time. Atmospheric benzene was significantly higher among road tanker drivers than among car mechanics. The arithmetic mean +/- SD, median, and geometric mean values were, respectively, 0.48 +/- 1.49, 0.14, and 0.06 mg/m3 among car mechanics and 1.88 +/- 4.18, 0.68, and 0.65 mg/m3 among road tanker drivers. In the latter case the increase was caused by transport of unleaded petrol and correlated with the volume of the tank. Among car mechanics, tobacco smoking, windy conditions, dismantling of petrol filters, and handling of petrol increased atmospheric benzene levels. Urinary muconic acid was increased significantly among car mechanics (148 +/- 137, 127, and 111 micrograms/g) and among road tanker drivers (309 +/- 420, 137, and 151 micrograms/g) as compared with the controls (49 +/- 46, 33, and 33 micrograms/g). Among road tanker drivers, alcohol intake and transportation of unleaded petrol increased the excretion of muconic acid, which was also directly related to the volume of the tank. Among car mechanics, professional factors (dismantling of petrol filters, handling of and washing of hands with petrol) and nonprofessional factors (tobacco smoking and damaged skin on the hands and forearms) increased muconic acid excretion. In the control group, tobacco smoking increased its excretion. LAPA was not significantly modified among exposed workers. There was a weak but significant linear correlation between LAPA and muconic acid. These results suggest that to reduce exposure to benzene in unleaded petrol, individual and collective safety measures should be imposed in both occupations.

Air Pollutants, Occupational↗
PubMed1993

Influence of isosorbide dinitrate on superior mesenteric artery impedance in humans.

In a randomized, double-blind, placebo-controlled crossover study the acute effect of isosorbide dinitrate (ISDN) on the superior mesenteric artery velocity waveform was studied in 10 healthy subjects (mean age 48.2 years) over a 10-minute period. The superior mesenteric artery pulsatility index (PI), which quantifies the blood velocity waveform, increased from the second minute following sublingual administration of 5 mg ISDN (basal PI 4.88 +/- 0.32) and reached its upper level (8.22 +/- 1.38) from the fourth minute on. In comparison with placebo, the significant rise of PI (second minute) occurred before the significant decrease of systolic blood pressure (ninth minute) and before the significant increase in the heart rate (fourth minute). Diastolic and mean arterial blood pressures remained unchanged. These observations suggest an immediate vasoconstrictive effect of ISDN on the resistance vessels of the vascular bed of the superior mesenteric artery.

Aged↗
PubMed1993

Results of extracorporeal shock wave lithotripsy of gall bladder stones in 693 patients: a plea for restriction to solitary radiolucent stones.

During a period of 24 months 693 consecutive patients with symptomatic gall bladder stones (526 males, 167 females; mean age 51 years, range 18-89) were treated by extracorporeal shock wave lithotripsy with a Piezolith 2300. The procedure was carried out on an out-patient basis without analgesics or sedatives. Concomitant chemolitholytic treatment (ursodeoxycholic and chenodeoxycholic acid 7.5 mg/kg/day each) was administered until three months after total fragment clearance for a maximum therapy period of 1.5 years. In 601 patients with radiolucent stones complete clearance of all fragments was obtained after three, six, 12, and 18 months in respectively 20, 41, 64, and 78%. Actuarial analysis of the subgroups according to the stone mass (size and number) selected an ideal patient population with solitary stones less than 20 mm diameter (84% stone free after one year). The results are significantly less good when the greater the number of stones or their maximal diameter increases. Treatment was interrupted in 3.6% of the patients. In 90 sludge or fragments remain present. Twenty five patients were lost to follow up for non-biliary reasons. Stone recurrence was 5.7% at one year and was observed both in patients with solitary and multiple stones. A cost effectiveness analysis suggests that laparoscopic cholecystectomy is the most effective and economic solution, although extracorporeal shock wave lithotripsy for solitary radiolucent stones less than 2 cm is cheaper than conventional cholecystectomy. Extracorporeal shock wave lithotripsy for multiple stones is the most expensive and least effective option.

Adolescent↗
PubMed1992

Epidemiological study of gastrointestinal and liver effects of carbon disulfide.

In the framework of an extensive health survey, 119 viscose rayon workers exposed to carbon disulfide (CS2) and 79 workers from other plants not exposed to any toxic agent in the working environment underwent a gastrointestinal examination including a self-administered questionnaire, abdominal palpation, percussion and a number of liver function tests. In the viscose rayon factory the working conditions have not changed since 1932. Personal monitoring performed in 17 jobs showed CS2 exposures varying from 4 to 112 mg.m-3. For each individual a cumulative CS2 exposure index (CS2 index) was calculated. Univariate analysis of the questionnaire findings showed significantly higher prevalences of anorexia (37.0% vs 11.4%, P less than 0.0001), vomiting (12.6% vs 3.8%, P = 0.04), and recent weight loss (10.9% vs 1.3%, P = 0.009) in the exposed than in the non-exposed workers. The exposed workers had a larger total number of gastrointestinal complaints and a larger proportion reported at least one complaint at least once a month than the non-exposed ones. Abdominal tenderness was very rare in both groups. In multiple logistic regression analysis, adjusting for alcohol intake, smoking, body mass index (BMI), coffee consumption, commuting time, stress at work, shift work, educational level, family history of ulcer disease and intake of medication, significant associations with exposure were found for anorexia (P = 0.0001), nausea (P = 0.009), vomiting (P = 0.002) and flatulence (P = 0.03). Stress at work was a determinant for quite a few digestive complaints, but shift work was not significantly associated with any of them.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Concentrations of 5-ASA and Ac-5-ASA in human ileocolonic biopsy homogenates after oral 5-ASA preparations.

Intramucosal 5-aminosalicylic acid (5-ASA) and acetylated 5-ASA (Ac-5-ASA) concentrations were determined in ileocolonic biopsy specimens from 61 patients with irritable bowel syndrome treated for one week with near equimolar doses of different slow release preparations of 5-ASA (Claversal, Asacol, or Pentasa) or azo-bound drugs (Salazopyrin, Dipentum). The transit time in these patients was accelerated by a laxative, metoclopramide, and colonic lavage. The presence of 5-ASA in the mucosa was confirmed by autofluorescence. The highest concentrations of 5-ASA were obtained after Asacol (mean (SEM), 298.5 (37.3) ng/mg wet wt), followed by Claversal 500 mg (108.8 (11.7) ng/mg wet wt) and Pentasa (25.7 (2.2) ng/mg wet wt). Very low concentrations only were observed after Claversal 250 mg (0.3 (0.03) ng/mg wet wt), Salazopyrine (1.2 (0.1) ng/mg wet wt), and Dipentum (11.0 (3.2) ng/mg wet wt). The results for Ac-5-ASA were similar but the concentrations were generally lower. Serum concentration-time curves over eight hours were obtained from 34 healthy volunteers after a single oral dose of 400 to 500 mg of the different drugs. For the slow release forms, an apparently inverse relationship was found between the area under the curve of the serum concentrations and the intramucosal concentrations, supporting the importance of the local availability of the drug. This inverse relationship was absent for the azo-bound drugs. Colonic washout induced mechanical removal of intraluminal 5-ASA with a secondary disturbance in absorption resulting in a rapid decline in the serum concentrations. However, only for Dipentum did this result in significantly lower 5-ASA mucosal concentrations. This is the first reported attempt to evaluate the mucosal availability of 5-ASA after different oral preparations. It shows that where transit time is accelerated higher mucosal concentrations occur after slow release preparations (except for Claversal 250 mg) than after azo-bound drugs. Additional studies are necessary to correlate these concentrations with clinical effects.

Administration, Oral↗
PubMed1992

Arcuate ligament syndrome mimicking celiac occlusion.

In a patient with weight loss and a systolic epigastric murmur, aortography demonstrated positional celiac axis occlusion. Color Doppler imaging of the celiac axis showed occlusion in the supine position, but patency was documented during deep inspiration and with the patient in the upright position. This report documents a rare example of extreme celiac axis compression with position-dependent celiac patency.

Adult↗
PubMed1991

High-performance liquid chromatographic assay for the determination of 5-aminosalicylic acid and acetyl-5-aminosalicylic acid concentrations in endoscopic intestinal biopsy in humans.

A high-performance liquid chromatographic method for the simultaneous determination of 5-amino-salicylic acid (5-ASA) and N-acetyl-5-ASA (Ac-5-ASA) concentrations in endoscopic mucosal biopsy homogenates is presented. The mean recoveries of 5-ASA and Ac-5-ASA from spiked blank biopsy homogenates ranged from 95.9 to 120% and from 92.5 to 100%, respectively. The coefficients of variation for 5-ASA and Ac-5-ASA were 0.7-8.6% and 1.4-12.9%, respectively. This method is useful for direct determination of topical availability of 5-ASA and Ac-5-ASA and probably an accurate parameter of drug bioavailability.

Aminosalicylic Acids↗
PubMed1991

New developments in stem cell transplantation with special reference to the first in utero transplants in humans.

Based on the experience acquired in post-natal liver transplantation since 1974, we recently initiated pre-natal, in utero stem cell transplantation from the human fetal liver. The first two fetuses that we treated had immunodeficiencies, the third one had thalassemia major. Donors and recipients were not matched. The fetal cells were infused in the umbilical vein of the first two patients and injected intraperitoneally into the third one, under ultrasonic visualization. The first patient, born in 1988, has both engraftment of donor cells and reconstitution of cell-mediated immunity. This child, who had bare lymphocyte syndrome, has no clinical manifestation of the disease and he lives normally at home. The second child, born in 1989, has not yet developed a significant reconstitution of immunity although donor cell engraftment has been proven (Y chromosome in this female patient). The third patient has also evidence of donor cell take (Y chromosome in a female patient) but the effect on thalassemia has not yet been fully analyzed (donor hemoglobin present in small quantity). In all 3 cases, no side-effect of any kind developed in the mother nor in the fetus. Several advantages appear to be associated with in utero FLT: increased probability of graft take, ideal isolation of patient (in the uterus), optimal environment for fetal cell development (in the fetal host).

Female↗
PubMed1990

[Penis endoscopy: our experience apropos of 200 cases].

The use of the colposcope and acetic acid in the man has shown many genital lesions due to papillomavirus which had not been revealed until then by clinical examination. The authors study the prevalence of these lesions in 200 partners of women with an HPV genital infection. 71.5 per cent abnormal peniscopies were found; 73.5 per cent in the group of partners of women presenting a simple viral disease and 63.5 per cent when the women has an associated cervical dysplasia. 34 per cent of the patients had macroscopically typical or histologically proven viral lesions and 14 per cent had minor epithelial lesions evoking the presence of HPV. On the whole, considering the prevalence of the masculine lesions, the peniscopic screening seems necessary to stop the transmission chain.

Adolescent↗
PubMed1989

Ileocolonoscopy in seronegative spondylarthropathy.

A prospective endoscopic and histologic study of terminal ileum and colorectum in 211 patients with seronegative spondylarthropathy revealed macroscopic inflammatory lesions varying from erythema to superficial erosions in 30% of the patients and microscopic inflammation in 61%. Two types of inflammation were observed: an acute inflammation resembling an infectious enterocolitis and a chronic inflammation. In idiopathic reactive arthritis both types of inflammation were equally present, whereas chronic inflammation predominated in patients with ankylosing spondylitis. In 32% of patients with chronic inflammation, the lesions particularly resembled early Crohn's disease. Repeat ileocolonscopy on 19 patients demonstrated a parallel evolution of joint symptoms and histologic lesions. All patients with acute inflammation went into clinical and histologic remission, whereas lesions persisted in patients with Crohn-like inflammation. In patients with chronic inflammation, remission and persistence were observed equally. This study identified a group of patients with seronegative spondylarthropathy which, even in the absence of gastrointestinal symptoms, showed evidence of gut inflammation, probably inducing an increased gut permeability with transgression of the oral tolerance and absorption of provocative antigens into the circulation. It is also possible that both diseases reflect a common underlying process.

Arthritis↗
PubMed1989

Fungal colonization of the esophagus.

A prospective study was conducted in 224 patients to determine the clinical significance of esophageal colonization with yeasts under different conditions. In accordance with the results of direct smear microscopic examination and culture of esophageal brushings, patients were divided into three groups: positive, negative, and the patients, in whom saprophytic forms were detected. A higher prevalence of positive findings was noted in patients with predisposing factors for yeast invasion than in patients free of underlying disease. Eleven percent of patients with an endoscopically normal appearing esophagus were positive. We have the impression that this situation may represent a preclinical condition of fungal esophagitis. Patients treated with H2-blocking agents showed a significantly higher incidence of positive findings, than did those without such treatment. Whether patients suffering from a refluxesophagitis resistant to long-term treatment with H2 blockers, but with a significant colonization by yeasts, could benefit by an additional treatment with antimycotics remains a controversial issue and should be studied in a controlled way.

Adult↗
PubMed1988

Congenital hepatic fibrosis.

We report the clinical features of 7 men (mean age 22 years, range 7-53 years) with congenital hepatic fibrosis (CHF). Five patients presented with variceal bleeding and/or hepatosplenomegaly due to portal hypertension. Cholangitis was the presenting symptom in the other 2 cases. Diagnosis was established by histological examination of a surgical wedge biopsy (4 patients) or needle biopsy (3 patients). A portal-systemic shunting was performed in 6 patients, three times prophylactically. None of the 5 survivors developed chronic hepatic encephalopathy. Recurrent bouts of cholangitis with septicemia and hepatic abscesses were a major complication in 5 patients with a fatal outcome in 2 cases. Six patients had associated small and large cysts in the cortex of both kidneys, compatible with adult-type polycystic disease. One patient developed terminal renal insufficiency. In 3 patients kidney function remained normal at a mean follow-up time of 7.5 years (range 1-18 years). In 2 families (4 cases) an autosomal dominant inheritance of renal disease was suggested. This study demonstrates that CHF is a rare cause of portal hypertension in late childhood and in adults. Cholangitis is a severe and frequently fatal complication. Association with a variety of congenital renal abnormalities is very frequent. However, the association with adult-type polycystic disease as reported in 4 cases is very rare.

Adolescent↗
PubMed1988

Endoscopic sclerotherapy: the value of balloon tamponade and the importance of disinfection.

Endoscopic sclerotherapy in active variceal bleeding stopped bleeding in 48 out of 67 patients (72%). Survival of the acute bleeding episode was related to liver function: 6% mortality in Child A patients vs. 48% mortality in Child C. Comparing two treatment modalities: 24 h Linton balloon tamponade followed by sclerotherapy vs. sclerotherapy alone, our results in comparable groups slightly, although not significantly, favor tamponade-sclerotherapy treatment: 75% survival vs. 71%. As this treatment modality is more convenient and helps to avoid dangerous aspiration pneumonia, we advocate balloon tamponade prior to sclerotherapy in acute variceal bleeding. In maintenance treatment 65 patients were treated until eradication of varices. The rebleeding risk was 0.034% per patient per month, with 64% of the rebleeding within the 2 first months before complete eradication of the varices. The long-term survival depends largely on liver function: one year survival of 88% in Child A vs. 30% in Child C. Using Aethoxysklerol 1% in intravariceal injection, no stricture occurred. Using a sterile injection needle and a glutaraldehyde-disinfected endoscope, no infectious complications directly related to the procedure occurred, and all hemocultures remained negative.

Adolescent↗