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Biomedical subjects

P Boyer

Publications and source records attributed to P Boyer.

At least 19 recordsLinked to original sources

Protein free diet feeding: effects on sympathetic activity and salivary evoked secretion in the submandibular gland of the rat.

Protein restriction impairs the salivary flow rate and composition in human and rats. The aim of the present work was to establish the effect of low protein (casein 5%) and protein free (casein 0%) isocaloric diets on sympathetic activity and salivary evoked secretion in the submandibular gland (SMG) of the rat. After 21 days, rats fed casein 0% presented: (a) a significant shift to the left of the dose-response curves (DRC) to the autonomic agonists-norepinephrine (NE), methoxamine, isoproterenol (ISO) and methacholine; (b) increased food consumption (p<0.001); (c) decreased body (p<0.001) and SMG (p<0.001) weights maintaining SMG/body (w/w) relation; (d) enhanced submandibular alpha1-adrenoceptor number without changes in the apparent dissociation constant (Kd); (e) increased submandibular NE content (p<0.05) and phosphoinositoside hydrolysis (p<0.001); (f) decreased submandibular tyrosine hydroxylase activity (TH) (p<0.01). Casein 5% feeding increased food consumption (p<0.01) and reduced body weight (p<0.05). This protein restriction increased metacholine-evoked salivation, but it altered neither submandibular sympathetic activity nor sympathetic-induced salivary secretion as compared to the Control group (C) fed a similar diet containing 25.5% protein. Present results suggest that in the adult rat, a protein free diet during 21 days lowers SMG sympathetic and cholinergic activity leading to supersensitivity as revealed by up-regulation of alpha1-adrenergic receptor number and increased autonomic-evoked salivation.

Adrenergic alpha-Agonists↗

[Bipolar shoulder prosthesis for rheumatoid arthritis with irreparable rotator cuff tear: results after 5 years' follow-up].

PURPOSE OF THE STUDY: The goal of this study was to assess the clinical and radiological outcome of bipolar shoulder prosthesis in twelve shoulders with rheumatoid arthritis (RA) and irreparable rotator cuff tears. MATERIAL AND METHODS: The follow-up was more than five years (range 2-9 years). In addition, in order to investigate the effect of rheumatoid arthritis on outcome, results were compared with ten bipolar shoulder prostheses implanted for osteoarthritis with massive rotator cuff tears. RESULTS: The mean preoperative Constant score was 16.9 points with 2.6 points for pain, 4.2 points for activity, 9.5 points for motion and 0.6 points for force. The preoperative active motion was 63.8 degrees for forward flexion, 45 degrees for abduction and 12 degrees for active external rotation. At last follow-up, the average Constant score was 39.4 points with 10.7 points for pain, 10.8 points for activity, 13.8 points for motion and 4.1 points for force. Regarding the active motion, mean forward flexion was 83.7 degrees, 70.4 degrees for abduction and 29.1 degrees for external rotation. The complication rate was low, mainly superior migration due to infraspinatus tear and glenoid wear. Satisfactory deltoid arm level was achieved in all patients and no loosening was observed. Preoperative and postoperative scores of the rheumatoid group were not significantly different from the arthritis group (p<0.001). DISCUSSION: Our findings suggest that bipolar shoulder prosthesis provides a viable replacement alternative in RA combined with massive rotator cuff tear with a low rate of complication. Bipolar shoulder prosthesis demonstrates no clear superiority over conventional hemiarthroplasty regarding improved motion and glenoid wear. In addition, no significant difference with arthritis was observed (p<0.05), assuming that outcome depends principally on the preoperative condition of the rotator cuff. CONCLUSION: Some massive tears involving the subscapularis tendon can lead to anterior recurrence after bipolar shoulder prosthesis. They might be a limit to the procedure and require a reversed shoulder prosthesis or a glenohumeral arthrodesis.

Aged↗

Double-blind randomized evaluation of clinical and biological tolerance of polyethylene glycol 4000 versus lactulose in constipated children.

OBJECTIVES: To assess the safety of a polyethylene glycol (PEG) 4000 laxative without additional salts in pediatric patients. STUDY DESIGN: This was a 3-month multicenter, randomized, double-blind, double-dummy, lactulose-controlled, parallel study enrolling 96 ambulatory constipated children aged 6 months to 3 years, treated daily with 4-8 g PEG or 3.33 g-6.66 g lactulose. Total protein, albumin, iron, electrolytes, and vitamins B9 (folates), A and D (25OHD3) were measured in blood before and after treatment (day 84) in a central laboratory. RESULTS: The percentage of children with at least one value out of normal range at day 84 with respect to baseline status (with or without at least one value out of normal range), i.e. the primary endpoint, was 87% and 90% in the PEG and lactulose groups, respectively, without any difference between groups. The whole blood parameters showed no qualitative or quantitative treatment-related changes. Vitamin A values were above normal range in 56% and 41% of children at baseline versus 33% and 36% at day 84 in the PEG and lactulose groups, respectively. Iron values were similarly under normal range in 47% and 51% at baseline versus 42% and 51% at day 84. Clinical tolerance was similar for both treatments except for vomiting and flatulence, which were significantly higher with lactulose. Significantly higher improvements were evidenced with PEG regarding stool consistency, appetite, fecaloma and use of additional laxatives. CONCLUSION: This 3-month study in 96 constipated children aged 6 months to 3 years confirms the long-term tolerance of PEG 4000 in pediatrics and indicates a PEG efficacy similar to or greater than that of lactulose.

Cathartics↗

[Traumatic obturator foramen hip dislocation: a case report and review of the literature].

We report a case of traumatic anteroinferior (obturator foramen) hip dislocation in an adult. Femoral neck fracture occurred during reduction of the dislocation. Cephalic necrosis required total hip arthroplasty. We call attention to the difficult reduction of traumatic obturator formaen dislocation. We reviewed the literature concerning prognostic factors and propose a therapeutic attitude.

Adult↗

[Reliability of the KT-1000 arthrometer (Medmetric) for measuring anterior knee laxity: comparison with Telos in 147 knees].

PURPOSE OF THE STUDY: The purpose of this study was to compare the reliability and the reproducibility of both the KT-1000 arthrometer (Medmetric) and Telos for measuring anterior knee laxity. The Telos was used as the reference technique. MATERIAL AND METHODS: Criteria for inclusion were preoperative anterior knee laxity, normal contralateral knee, and intra-articular surgery to reconstruct the anterior cruciate ligament. Between January 1st, 2000 and October 31st, 2001, 147 patients were operated on for knee instability using an autograft (BPTB or hamstring tendons). For each patient, comparative measurements were made for both knees preoperatively and postoperatively with an average follow-up of 16 months. Measurements with the KT-1000 apparatus were made with forces of 67 N, 89 N, 134 N and manual maximal force. For the Telos, a force of 250 N was used as recommended by the manufacturer. We also evaluated intraobserver variation between the two devices. RESULTS: The anterior translation preoperatively as measured by the KT-1000 at 89N was 4.2 +/- 2.4 mm and 6.3 +/- 2.5 mm at maximal manual force. The result for Telos was 3.0 +/- 3.6 mm. The data scatter obtained with Telos was wider than with KT-1000 (p<0.03). The sensitivity of Telos was 72% with 28% false negatives. With KT-1000, sensitivity increased as tensile force increased. Sensitivity was 65% at 89N, 73% at 134N and 92% at maximal manual force. The concordance between the KT1000 and Telos data was low for either preoperative (10%) or postoperative (30%) measurements. DISCUSSION AND CONCLUSION: In this study, the results of sensitivity and reproducibility as well as the minimal scatter of the values demonstrated the reliability of KT-1000 for measuring anterior translation of the knee. We recommend routine use of the KT-1000 device for measuring knee laxity. The low sensitivity and the high rate of false negative observed with Telos raises the question of its use a reference technique.

Adolescent↗

[Spinal extradural meningiomas: MRI findings in two cases].

Spinal extradural meningiomas are rare and may be easily confused with malignant neoplasms. We report two unusual cases of epidural spinal meningioma one within the left C6-C7 foramen and the other within the left posterolateral epidural space at the T3-T4 level. Low signal intensity of the tumor on T2-wi, thickening and enhancement of the dura with only the possibility of bone erosion are the most characteristic MR findings.

Adult↗

Functional and dysfunctional impulsivity: contribution to the construct validity.

OBJECTIVE: Impulsivity has been found to be an important trait of personality, whose consequences are not always negative although available questionnaires focused on its 'dysfunctional' aspect. METHOD: Dickman's Functional and Dysfunctional Impulsivity questionnaire has been translated into French, and filled out by students. The tetrachoric correlation matrices were factor analysed. RESULTS: The psychometric properties are very close to those of the English version, and we recovered both factors in males and females. The factor similarities between the genders (in our sample) and between the languages (English vs. French) are very good. The Dysfunctional scale is correlated with the Motor Impulsivity subscale of the Barratt Impulsiveness Scale, and both scales are grossly independent from Spielberger's Trait-Anxiety Inventory. CONCLUSION: Our results support a two-factor solution similar to the English one. Nevertheless, the validity of the functional factor remains to be investigated in further studies.

Adult↗

Quality of Sexual Life Questionnaire (QVS): a reliable, sensitive and reproducible instrument to assess quality of life in subjects with erectile dysfunction.

A French quality of life questionnaire specific to erectile dysfunction (ED), 'QVS' for 'Questionnaire de Vie Sexuelle', has been developed. This paper describes its validation: item reduction and reliability (internal consistency and reproducibility), construct validity and criterion validity (clinical, discriminant and concurrent). The initial 40-item questionnaire was administered once to 316 ED and 117 control subjects, and twice (D0 and D7) to 104 ED and 29 control subjects. Item reduction gave a 27-item questionnaire with three scales (Sexual Life, Skills and Psychosocial Well-being) and four scores (one score for each scale and a Global Index). Psychometric analyses demonstrated the reliability and the validity of the QVS. The questionnaire was able to discriminate patients according to the presence or severity of ED. The Skills scale was the least sensitive. Analysis of responsiveness to change over time still needs to be addressed to consider the questionnaire as a fully validated instrument.

Adult↗

The detection of contingency and animacy from simple animations in the human brain.

Contingencies between objects and people can be mechanical or intentional-social in nature. In this fMRI study we used simplified stimuli to investigate brain regions involved in the detection of mechanical and intentional contingencies. Using a factorial design we manipulated the 'animacy' and 'contingency' of stimulus movement, and the subject's attention to the contingencies. The detection of mechanical contingency between shapes whose movement was inanimate engaged the middle temporal gyrus and right intraparietal sulcus. The detection of intentional contingency between shapes whose movement was animate activated superior parietal networks bilaterally. These activations were unaffected by attention to contingency. Additional regions, the right middle frontal gyrus and left superior temporal sulcus, became activated by the animate-contingent stimuli when subjects specifically attended to the contingent nature of the stimuli. Our results help to clarify neural networks previously associated with 'theory of mind' and agency detection. In particular, the results suggest that low-level perception of agency in terms of objects reacting to other objects at a distance is processed by parietal networks. In contrast, the activation of brain regions traditionally associated with theory of mind tasks appears to require attention to be directed towards agency and contingency.

Adolescent↗

Pregnancies after ICSI using sperm with abnormal head-tail junction from two brothers: case report.

We report ICSI pregnancies in two couples with a history of long standing primary infertility in which the sperm of the male partner were either acephalic or had abnormal head-midpiece attachments. The two couples, in which the men are brothers, underwent ICSI. Sperm were analysed by transmission electron microscopy and immunocytochemistry with an anti-MPM2 monoclonal antibody. The first couple underwent two ICSI cycles, each consisting of the injection of two mature oocytes and the transfer of two embryos. A successful pregnancy occurred after the second transfer and led to the birth to a healthy girl. The second couple underwent three ICSI cycles, each consisting of the injection of 18 oocytes and the transfer of two embryos; the last of these led to a triple ongoing pregnancy which included two identical twins. Caesarean section led to the birth of three fetal-growth restricted children. This case report demonstrates that ongoing pregnancies can be achieved in cases of abnormal development of the head-neck attachment. The genetic origin of this syndrome is generally accepted, but the phenotypic heterogeneity observed by light and electron microscopy among published cases suggests that there are a variety of genetic causes of this syndrome.

Adult↗

[Place of the surgery in the management of brainstem cavernomas. Results of a multicentric study].

OBJECTIVE: To compare the outcome between operated and non-operated brainstem cavernomas. METHOD: Clinical and radiological data of 30 patients harboring 35 brainstem cavernomas were retrospectively reviewed. The mean follow-up period was 47 months. Relationship between the cavernoma and the pi maer was graded. The histology of each operative case was systematically confirmed. The Karnofsky mean score was calculated at admission and at the end of the follow-up period. Patients were classified in three groups according to their outcome grade (Group I=good; Group II=unchanged; Group III=worse). We compared the outcome between operated and non-operated patients. For operated cases, we found several factors of poor outcome. Statistical tests used to compare the groups of patients were Yates modified chi(2) with calculation of the exact probability. Chosen risk was 5%. RESULTS: Thirty-eight percent of operated patients were permanently disabled after surgery whereas the same proportion was improved. None of the patients in the control group worsened at the mean 47-month follow-up despite the occurrence of two hemorrhagic events. Statistical study showed that treatment modality affected clinical outcome in these patients. Only patients presenting with multiple deficits and progressive neurological deterioration were improved with surgery. Surgical access through the floor of the fourth ventricle was correlated with a poor outcome. Partial removal of the cavernoma increased the risk of future hemorrhage. CONCLUSION: Surgery showed no proof of its efficiency in the management of brainstem cavernomas at the end of the follow-up period. Indications of surgical treatment must be restricted to cases with a severe and progressive neurological deterioration.

Adolescent↗

CASTEAUR: a simple tool to assess the transfer of radionuclides in waterways.

The CASTEAUR project proposes a simplified tool to assess the transfer of radionuclides between and in the main biotic and abiotic components of the freshwater ecosystem. Applied to phenomenological modeling, various hypotheses simplify the transfer equations, which, when programmed under Excel, can be readily dispatched and used. CASTEAUR can be used as an assessment tool for impact studies of accidental release as well as "routine" release. This code is currently being tested on the Rhone River, downstream from a nuclear reprocessing plant. The first results are reported to illustrate the possibilities offered by CASTEAUR.

Algorithms↗

[Epidermoid cyst of the fourth ventricle: four case reports].

Patients with epidermoid cyst of the fourth ventricle usually present with headaches and/or disequilibrium. These cysts are characterized by a focal lesion that is nearly isodense to CSF at CT and nearly isointense to CSF on T1W and T2W MR images. MRI using FLAIR and diffusion weighted images as well as 3D CISS acquisitions is useful to better characterize the lesions and their relation with the vermis, foramen magnum and CP angle cisterns. DWI images are useful for postsurgical evaluation of residual tumor. Extension of the cyst into the CP angle cisterns usually precludes complete surgical resection.

Adult↗

How the brain perceives causality: an event-related fMRI study.

Detection of the causal relationships between events is fundamental for understanding the world around us. We report an event-related fMRI study designed to investigate how the human brain processes the perception of mechanical causality. Subjects were presented with mechanically causal events (in which a ball collides with and causes movement of another ball) and non-causal events (in which no contact is made between the balls). There was a significantly higher level of activation of V5/MT/MST bilaterally, the superior temporal sulcus bilaterally and the left intraparietal sulcus to causal relative to non-causal events. Directing attention to the causal nature of the stimuli had no significant effect on the neural processing of the causal events. These results support theories of causality suggesting that the perception of elementary mechanical causality events is automatically processed by the visual system.

Adult↗

The composite scale of morningness: further psychometric properties and temporal stability.

OBJECT: To assess the temporal stability of the French version of the Composite Scale of Morningness (CSM), and to replicate our previous findings in an independent sample in order to confirm the good internal properties of this instrument. METHOD: Sixty nursing students (11 males and 49 females) filled out the Composite Scale of Morningness on two occasions over a 13-month period. RESULTS: The scale's reliability is high: Cronbach's alpha = 0.874 in males and 0.904 in females. The CSM total scores are normally distributed and independent of gender. They do not differ between occasions, and are highly correlated: r = +0.885 in males and r = +0.930 in females. CONCLUSION: The French version of the CSM is stable over time and psychometrically reliable. These are the characteristics of a personality trait. Further studies should explore its personality, biological and genetic correlates.

Circadian Rhythm↗

Evaluation of the supervisory system in elderly subjects with and without disinhibition.

UNLABELLED: Disinhibition and irritability, defined as loss of behavioral and emotional control, are frequent in the elderly. The working hypothesis for this study was that these disorders are associated with a cognitive alteration of control processes that manifests as non-routine behavior because of the dysfunction of a general executive component known as the supervisory attentional system (SAS). METHODS: A total of 28 elderly subjects with mild cognitive impairment were recruited and divided into two groups using the Neuropsychiatric Inventory. Fourteen subjects were allocated to the disinhibited group and 14 subjects matched for age, sex and educational level formed a disinhibition-free control group. The neuropsychological battery included the following tests: Mini Mental Score Evaluation, Boston Naming test, Token test, Trail Making and Verbal Fluency. Two tasks were specifically designed to stress the SAS: 1) A specific verbal sentence arrangement task in which subjects had to use sequential reasoning with verbal material. Each test sequence consisted of a series of words shown in jumbled order. The construction of some sequences had to be done by using familiar routine associations (valid conditions). In contrast, other sequences required the overriding selection of familiar routine associations, which were inappropriate within the general context of the task (invalid conditions). 2) Using the Continuous Performance Test, four aspects were evaluated: sustained, selective, preparation and suppressive attention. RESULTS: The only group differences in neuropsychological test results were the following: 1) the sentence arrangement task. In comparison with the control group, the disinhibited group was impaired in invalid conditions and the calculated difference between the number of correct responses in invalid conditions minus that in valid conditions was significantly higher; and 2) the CPT. Disinhibited subjects had a significantly lower number of hits, exclusively in the 'suppressive attention' paradigm. These results suggest that subjects with disinhibition have impaired supervisory system function.

Aged↗

The effects of psychoactive drugs and neuroleptics on language in normal subjects and schizophrenic patients: a review.

The aim of this survey is to present an overview of research into psychopharmacology as regards the effects of different psychoactive drugs and neuroleptics (NL) on language in normal subjects and schizophrenic patients. Eighteen studies that have investigated the effects of different drugs (alcohol, amphetamines, secobarbital, L-dopa, psilocybin, ketamine, fenfluramine) and neuroleptics (conventional and atypical) on language are reviewed. There are no studies concerning the effects of neuroleptics on language in healthy subjects. The results of the effects of other molecules indicate that language production can be increased (alcohol, amphetamine, secobarbital), rendered more complex (d-amphetamine), more focused (L-dopa) or more unfocused (psilocybin) and clearly impaired (ketamine). For schizophrenic patients, most studies show that conventional neuroleptic treatments, at a therapeutic dosage and in acute or chronic mode, reduce language disorders at all levels (clinic, linguistic, psycholinguistic). In conjunction with other molecules, the classical NL, when administered at a moderate dosage and in chronic mode, modify language in schizophrenia, either by improving the verbal flow and reducing pauses and positive thought disorder (NL + amphetamine) or by inducing an impairment in the language measurements (NL + fenfluramine). Clinical, methodological and theoretical considerations of results are debated in the framework of schizophrenic language disorders.

Adult↗