Seizure-related contrast enhancement of a ganglioglioma.
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Biomedical subjects
Publications and source records attributed to A Carpentier.
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The authors reviewed in a retrospective study 61 cases of severely head injury children who where admitted in the rehabilitation centre to evaluate the outcome 1 and 5 years after the brain injury. Neurologic and neuropsychologic status of children was assessed ad admission, 1 and 5 years later. Duration on intubation and age at time of head trauma were the worst functional prognosis.
The case of a young female with an acute idiopathic low cerebrospinal fluid pressure is presented. Clinical-imaging manifestations were typical and two consecutive blood patches resulted in a complete and durable resolution of the symptomatology. We present a review of the various investigation and therapeutic techniques.
Neurological complications, mainly cerebellar syndrome, have been associated with coeliac disease. We report the first observation of a 56-year-old woman with a chronic meningitis revealing coeliac disease. Neuralgia of the trijeminal nerve and cerebellar syndrome only appeared seven years after the onset of meningitis. MRI examination showed a cerebellar atrophy and a leucoencephalopathy. This case report emphasizes the utility of detection of anti-gliadin antibodies for the diagnosis of a chronic meningitis.
AIM: Localizing Heschl's gyrus with functional MRI (fMRI) is a particularly difficult challenge due to the noise of the echo planar sequences and the frequent activation of language areas during auditory paradigms. The goal of this study was to search for a paradigm capable of assessing only pure primary auditory cortex activation with fMRI. MATERIAL AND METHOD: Ten healthy adults were studied. Subjects were asked to continuously perform a visual decisional task while passively listening to an ON-OFF randomized paradigm of tones and rhythmic stimuli. Data were analyzed with SPM. RESULTS: Auditory cortex activation was assessed by observing activated pixels in functional images. Due to the distraction effect of the visual decisional task, functional images of pure primary auditory cortex were obtained in all subjects, with strong and selective activation in the Heschl's gyrus. CONCLUSION: This technique, coupled with fMRI data of language areas can be used as a preoperative tool for surgical preplanning in the left superior temporal region. It shows a clear distinction between resectable areas (primary auditory cortex) and not resectable essential areas (language areas).
We recently reported that the nonclassical HLA class I molecule HLA-G was expressed in the endomyocardial biopsies and sera of 16% of heart transplant patients studied. The aim of the present report is to identify cells that may be responsible for HLA-G protein expression during the allogeneic reaction. Carrying out mixed lymphocyte cultures in which the responder cell population was depleted either in CD4(+) or CD8(+) T cells, we found that soluble HLA-G5 protein but not the membrane-bound HLA-G isoform was secreted by allo-specific CD4(+) T cells from the responder population, which suppressed the allogeneic proliferative T cell response. This inhibition may be reversed by adding the anti-HLA-G 87G antibody to a mixed lymphocyte culture. That may indicate a previously uncharacterized regulatory mechanism of CD4(+) T cell proliferative response.
BACKGROUND: Results of conservative surgery are well established in degenerative mitral valve (MV) insufficiency. However, there are controversies in rheumatic disease. This study is the evaluation of one center for rheumatic MV insufficiency based on a functional approach. METHODS AND RESULTS: From 1970 to 1994, 951 patients with rheumatic MV insufficiency were operated on with the reconstructive techniques elaborated by Alain Carpentier. Aortic valve diseases were excluded. Mean age was 25.8 years (4 to 75), and sinus rhythm was present in 63%. The functional classification used was type I, normal leaflet motion, 71 patients (7%); type II, prolapsed leaflet, 311 patients (33%); and type III, restricted leaflet motion, 345 patients (36%). The combined lesion of prolapse of the anterior leaflet and restriction of the posterior was present in 224 patients (24%). Surgical techniques used were implantation of a prosthetic ring in 95%, shortening of the chords and leaflet enlargement with autologous pericardium, and commissurotomy. Hospital mortality rate was 2%. The mean follow-up was 12 years (maximum, 29 years): 8618 patients per year. Actuarial survival was 89+/-19% at 10 years and 82+/-18% at 20 years. The rate of thromboembolic events was 0.4% patients per year (33 events), with 3 deaths. Freedom from reoperation was 82+/-19% at 10 years and 55+/-25% at 20 years. The main cause (83%) of reoperation was progressive fibrosis of the MV. The actuarial rate of reoperation was 2% patients per year and was correlated to the degree of preoperative fibrosis. CONCLUSIONS: Conservative surgery of rheumatic MV insufficiency has a low hospital mortality rate and an acceptable rate of reoperation. The results are excellent regarding the minimal risk of thromboembolic events.
BACKGROUND: Mitral valve repair is considered the gold standard in surgery of degenerative mitral valve insufficiency (MVI), but the long-term results (>20 years) are unknown. METHODS AND RESULTS: We reviewed the first 162 consecutive patients who underwent mitral valve repair between 1970 and 1984 for MVI due to nonrheumatic disease. The cause of MVI was degenerative in 146 patients (90%) and bacterial endocarditis in 16 patients (10%). MVI was isolated or, in 18 cases, associated with tricuspid insufficiency. The mean age of the 162 patients (104 men and 58 women) was 56+/-10 years (age range 22 to 77 years). New York Heart Association functional class was I, II, III, and IV in 2%, 39%, 52%, and 7% of patients, respectively. The mean cardiothoracic ratio was 0.58+/-0.07 (0.4 to 0.8), and 72 (45%) patients had atrial fibrillation. Valve analysis showed that the main mechanism of MVI was type II Carpentier's functional classification in 152 patients. The leaflet prolapse involved the posterior leaflet in 93 patients, the anterior leaflet in 28 patients, and both leaflets in 31 patients. Surgical technique included a Carpentier's ring annuloplasty in all cases, a valve resection in 126 patients, and shortening or transposition of chordae in 49 patients. During the first postoperative month, there were 3 deaths (1.9%) and 3 reoperations (2 valve replacements and 1 repeat repair [1.9%]). Six patients were lost to follow-up. The remaining 151 patients with mitral valve repair were followed during a median of 17 years (range 1 to 29 years; 2273 patient-years). The 20-year Kaplan-Meier survival rate was 48% (95% CI 40% to 57%), which is similar to the survival rate for a normal population with the same age structure. The 20-year rates were 19.3% (95% CI 11% to 27%) for cardiac death and 26% (95% CI 17% to 35%) for cardiac morbidity/mortality (including death from a cardiac cause, stroke, and reoperation). During the 20 years of follow-up, 7 patients were underwent surgery at 3, 7, 7, 8, 8, 10, or 12 years after the initial operation. Valve replacement was carried out in 5 patients, and repeat repair was carried out in 2 patients. At the end of the study, 65 patients remained alive (median follow-up 19 years). Their median age was 76 years (age range 41 to 95 years). All except 1 were in New York Heart Association functional class I/II. CONCLUSIONS: Mitral valve repair using Carpentier's technique in patients with nonrheumatic MVI provides excellent long-term results with a mortality rate similar to that of the general population and a very low incidence of reoperation.
1. In 67 single motor units, the mechanical properties, the recruitment and derecruitment thresholds, and the discharge rates were recorded concurrently in the first dorsal interosseus (FDI) of human subjects during intermittent fatiguing contractions. The task consisted of isometric ramp-and-hold contractions performed at 50 % of the maximal voluntary contraction (MVC). The purpose of this study was to examine the influence of fatigue on the behaviour of motor units with a wide range of activation thresholds. 2. For low-threshold (< 25 % MVC) motor units, the mean twitch force increased with fatigue and the recruitment threshold either did not change or increased. In contrast, the twitch force and the activation threshold decreased for the high-threshold (> 25 % MVC) units. The observation that in low-threshold motor units a quick stretch of the muscle at the end of the test reset the unit force and recruitment threshold to the prefatigue value suggests a significant role for fatigue-related changes in muscle stiffness but not twitch potentiation or motor unit synchronization. 3. Although the central drive intensified during the fatigue test, as indicated by an increase in surface electromyogram (EMG), the discharge rate of the motor units during the hold phase of each contraction decreased progressively over the course of the task for motor units that were recruited at the beginning of the test, especially the low-threshold units. In contrast, the discharge rates of newly activated units first increased and then decreased. 4. Such divergent behaviour of low- and high-threshold motor units could not be individually controlled by the central drive to the motoneurone pool. Rather, the different behaviours must be the consequence of variable contributions from motoneurone adaptation and afferent feedback from the muscle during the fatiguing contraction.
AIMS/HYPOTHESIS: We have shown previously that the increase of plasma non-esterified fatty acids for 48 h results in decreased glucose-stimulated insulin secretion in lean and non-diabetic obese subjects. It is currently not known if a prolonged increase in non-esterified fatty acids also impairs the insulin secretory response to non-glucose secretagogues. METHODS: Heparin and intralipid (to increase plasma non-esterified fatty acid concentrations by about two- to fourfold) or normal saline was infused intravenously for 48 h in 14 non-diabetic obese subjects. On the third day in both studies, insulin, C-peptide, proinsulin, and insulin secretion rate were assessed in response to an intravenous arginine infusion at fasting glucose concentration and a second arginine infusion after a 60-min 11 mmol/l hyperglycaemic clamp. RESULTS: There were no significant differences detected in acute (5 min) or total (90 min) arginine-stimulated C-peptide or insulin secretion response in the heparin-intralipid study compared with the control group at fasting glucose or during hyperglycaemia. CONCLUSION/INTERPRETATION: We have shown that a prolonged increase in plasma NEFA does not blunt arginine-stimulated insulin secretion or plasma insulin concentrations in non-diabetic obese subjects. These findings suggest that the previously demonstrated NEFA-induced impairment in insulin secretory response to glucose cannot be generalized for non-glucose secretagogues.
BACKGROUND: Obstruction of the foramina of Magendie and Luschka represents one possible aetiology for a progressive tetra-ventricular hydrocephalus. METHOD: Our case report is a 58-year-old woman initially presenting with a pseudo-vertebrobasilar insufficiency clinical syndrome. A ventriculo-cisternostomy of the third ventricle was performed by an endoscopic procedure with a clinical and radiological success (three year follow-up). FINDINGS: Comparative studies of cerebrospinal fluid (CSF) flow measurements by cine magnetic resonance imaging (cine-MRI) showed that Magendie's and Luschka's foramina permeabilities were restored after the ventriculo-cisternostomy. INRTERPRETATION: This case shows that endoscopic ventriculo-cisternostomy of the third ventricle can provide an effective treatment for specific tetra-ventricular hydrocephalus. Cine-MRI findings open the discussion on possible aetiologies and pathophysiologies.
BACKGROUND: Preliminary studies showed that heat treatment of glutaraldehyde preserved valvular bioprostheses mitigates calcification. This study was carried out to define the physicochemical characteristics of the heat-treated tissues to elucidate the mechanism involved in the mitigation. METHODS: Glut bovine pericardium or porcine valve samples were treated at 50 degrees C in a 0.625% glutaraldehyde solution for 2 months. Some samples underwent assay for shrinkage temperature, moisture content, ninhydrin test, and acid hydrolysis, and other samples were incubated in human serum for 3 days and then analyzed by electrophoresis to study protein adsorption. RESULTS: Heat treatment mitigated calcification without adversely affecting shrinkage temperature (84.81 degrees C versus 83.95 degrees C) and moisture content (78.68% versus 78.71%). A significant reduction in free amino groups (0.15 versus 0.37 mol NH2/mol collagen) and a significant increase in resistance to acid hydrolysis were observed. Total protein content was similar, but significant differences were found for four proteins adsorbed in the tissues (167, 45, 11.6, and 10 kDa). CONCLUSIONS: The anticalcification effect of heat treatment may be attributed to structural changes, lipid extraction, increased resistance, and modifications of the type and concentration of the proteins adsorbed in the tissue.
BACKGROUND: The incidence of calcification of porcine valve bioprostheses shows important, and as yet unexplained, variations. Previous studies by others showed that osteopontin and osteocalcin are expressed in calcified porcine valve bioprostheses. However, no study has yet explored other proteins that could also be involved. METHODS: Twelve porcine valve bioprostheses were retrieved from 12 patients and were separated into two groups. Group 1 (n = 6) had early calcification after 4 to 9 years (mean, 6+/-2.3 years). The mean age of the patients at the time of implantation was 46+/-9 years. Group 2 (n = 6) had no calcification after 8 to 14 years (mean, 12+/-2.8 years). The mean age was 47+/-13.4 years. These valves were analyzed by electrophoresis, and the bands were quantified by densitometry. RESULTS: A 14-kd protein showed a 50% increase in the calcified group. A 31-kd protein found in the calcified group was not detected in the noncalcified group. Three other proteins (45, 39, and 28 kd) showed reduced adsorption in the calcified group. CONCLUSIONS: Important differences were found in the proteins adsorbed in calcified and noncalcified bioprostheses after implantation in patients. Besides osteopontin and osteocalcin, several other proteins may play a role in the process of calcification of valvular bioprostheses.
BACKGROUND: Proteins adsorbed by bioprosthetic tissues after implantation play a major role in the process of calcification. We investigated whether there are differences in protein adsorption between bovine pericardial and porcine valvular tissues that could correlate with the differences observed clinically. METHODS: Glutaraldehyde-treated bovine pericardial and porcine valve samples were implanted subcutaneously in rats and retrieved 1 month after implantation. Total protein content was assessed by Lowry's method. Qualitative analysis was performed by polyacrylamide gel electrophoresis. Quantitative analysis was performed by densitometry. RESULTS: Total protein content showed a higher protein concentration in porcine valve tissue than in pericardial tissue: 149+/-22.6 microg/mg dry tissue versus 108+/-12.7 microg/mg dry tissue (38% increase). In pericardial tissue, four protein bands (17, 16, 15.5, and 13.5 kd) showed decreased concentration when compared with porcine valve tissue, whereas one band (11 kd) showed increased concentration. CONCLUSIONS: Significant differences were found in protein content between bovine pericardial and porcine valve tissues. Correlations with clinical findings may lead to a better understanding of the mechanism involved in the process of calcification, particularly the role played by the structure of the tissues.
BACKGROUND: Lipids play a significant role in the process of calcification of bioprostheses. We assessed whether lipid extraction by ethanol, ether, or a surfactant could mitigate calcification of glutaraldehyde-treated bioprostheses. METHODS: On 200 bovine pericardium samples pretreated with 0.6% glutaraldehyde, lipid extraction was carried out by ethanol, ether, or the tween 80 surfactant, and combinations thereof. The treated tissues were implanted subcutaneously in 50 juvenile rats for 4 and 6 months. Lipids were analyzed by Fourier transform infrared spectrophotometer and chromatography before implantation. Calcium content of implanted tissues was assessed by atomic absorption spectrometer. RESULTS: Ethanol, ether, or surfactant did mitigate calcification. The most efficient pretreatments were the combination of ethanol and surfactant (calcium content: 15.5+/-6.8 microg/mg dry tissue after 6 months implantation) or the combination of ethanol, ether, and surfactant (13.1+/-6.2 microg/mg dry tissue) when compared with surfactant alone (42.9+/-12.7 microg/mg dry tissue). CONCLUSIONS: Ethanol or the combination of ethanol and ether added to the currently used glutaraldehyde-surfactant treatment further mitigates calcification.
BACKGROUND: Glutaraldehyde fixation (GT) is known to reduce immunologic reactions and tissue degeneration after implantation in humans. Sterilization after glutaraldehyde fixation (G-ST) improves the safety and reduces the tendency of GT valves to calcify. Intravenous immunoglobulins (IVIg) have been shown to reduce xenogeneic response against porcine tissue. We have investigated the effect of these fixation procedures combined with and without IVIg on the antigenicity of bioprostheses. METHODS: Lewis adult rats were implanted subcutaneously with a fresh, GT, or G-ST porcine heart valve pre- or posttreated with different amounts of IVIg. We followed by enzyme-linked immunosorbent assay and IgM and IgG titers against protein extracts from the porcine heart valves after implantation. Cellular reactivity was assessed in xenogeneic lymphoendothelial coculture experiments. Calcification content was also examined. RESULTS: Glutaraldehyde fixation partially decreased the humoral response against proteins of the implant but elicited a cellular xenogeneic response. Sterilization reduced these reactivities, but retained antigenicity. Intravenous immunoglobulin postincubated with GT valves before implantation reduced the antigenicity of the tissue to the same extent as G-ST valves, but had no effect on valvular tissue calcification. CONCLUSIONS: Our studies demonstrate that IVIg or the sterilization procedure (ST) reduced the cellular response against glutaraldehyde-fixed valves (GT), whereas reduced calcification was observed only with ST.
BACKGROUND: Bioprosthetic valve replacement in young patients remains a controversial issue due to a high rate of early calcification. Previous studies in our laboratory have shown that high-temperature fixation of glutaraldehyde preserved bioprosthesis (HTF) mitigates calcification. The first clinical application of this technique was started in 1991. METHODS: From January 1991 to September 1998, 50 patients in whom anticoagulants were contraindicated underwent single aortic valve replacement (n = 33) or mitral valve replacement (n = 17) using HTF bioprostheses. The age of the patients ranged from 7 months to 35 years (mean 22.7+/-6.8 years). The mean New York Heart Association status was 2.4. Mean follow-up 4 years +/- 1.8 for a total follow-up of 196 patient-years. RESULTS: There were no operative deaths and but there were two late deaths, one valve related. Structural failure occured in 4 patients (2%/patient-year) requiring a reoperation in 3 patients (1.5%/patient-year). No endocarditis or thromboembolic episodes were observed. At late examination (June 2000), 46 patients (92%) were in New York Heart Association class I or II, with a well functioning valve. CONCLUSIONS: Replacement with HTF bioprostheses in young patients has demonstrated encouraging midterm results with a low incidence of structural failure
PURPOSE: Functional magnetic resonance imaging (MRI) using two language-comprehension tasks was evaluated to determine its ability to lateralize language processing and identify regions that must be spared in surgery. METHODS: Two parallel cognitive language tasks, one using auditory input and the other visual input, were tested in a group of control subjects and in temporal lobe epilepsy patients who were candidates for surgical intervention. The patient studies provide an opportunity to compare functional MRI language localization with that obtained using Wada testing and electrocorticography. All of the patients in this study underwent all three procedures and a battery of neuropsychological testing. Such studies provide an opportunity not only to validate the fMRI findings but also, by comparing the patient results with those obtained in control subjects, to provide insight into the impact of a pathology such as epilepsy on cortical organization or functional patterns of activation. RESULTS: The results reveal both modality-dependent and modality-independent language-processing patterns for visual versus auditory task presentation. The visual language task activated distinct sites in Broca's area, BA (Brodmann area) 44 that were not activated in the auditory language task. The auditory language task strongly activated contralateral right BA22-21 area (homologous to Wernicke's area on the left). Language lateralization scores were significantly stronger for visual than for auditory task presentation. The conjunction of activation from the two different input modalities (modality-independent areas) likely highlights regions that perform more abstract computations (e.g., syntactic or pragmatic processing) in language processing. Modality-specific areas (e.g., right Wernicke, left fusiform gyrus, Broca BA44, supramarginal gyrus), appear to cope with the computations relevant to making contact with these more abstract dimensions. Patients showed recruitment of contralateral homologous language areas (p < 0.005) that was significantly above that found in a normal control group. Extra- and intraoperative cortical stimulations were concordant with the fMRI data in eight of 10 cases. The fMRI lateralization scores were also consistent with the Wada testing in 8/10 patients. CONCLUSIONS: The fMRI results demonstrate that the epileptic brain may be a progressive model for cortical plasticity.