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Biomedical subjects

C Dumont

Publications and source records attributed to C Dumont.

At least 19 recordsLinked to original sources
PubMed2006

T1-weighted cine FLASH is superior to IR imaging of post-infarction myocardial viability at 4.7T.

PURPOSE: Data are unavailable for rational selection of pulse sequences to assess postinfarction myocardial viability in rodents at high field strength. We implemented a widely used clinical inversion recovery (IR) sequence at 4.7T and compared the results to a heavily T1-weighted cine FLASH sequence (T1-CF) for assessment of infarction size. MATERIALS AND METHODS: Eleven infarcted rats were examined within 24 h of infarction after injection of Gadophrin-3 contrast agent. Images were acquired using both pulse sequences and a standard cine (SC) sequence. Estimates of infarct size were compared to TTC. Global LV function was compared between the T1-CF and SC sequences. RESULTS: SNR, relative SNR, and CNR for the infarcted and normal myocardium were significantly greater for the IR sequence. Infarction size was overestimated by both sequences, but correlated highly and showed very close agreement with TTC. Global function revealed no significant differences between T1-CF and SC. CONCLUSION: Both IR and T1-CF produced reliable results for assessment of infarction size at 4.7T. While the IR sequence delivers better overall SNR and CNR, the T1-CF allows concomitant assessment of global cardiac function with a much shorter acquisition time.

Animals↗
PubMed2005

Predictive factors for rapid loss on the mini-mental state examination in Alzheimer's disease.

OBJECTIVES: To seek predictors of rapid loss of cognition and to evaluate their frequency in a prospective study of patients suffering from Alzheimer's disease (AD). DESIGN: A one-year prospective study. METHODS: 312 AD patients from the memory clinic at Toulouse University Hospital, participants in the ELSA study, were enrolled. Rapid cognitive decline was defined as a 4-point or greater loss on the Mini-Mental State Examination (MMSE) in 6 months. Comprehensive geriatric and neuropsychological assessment was conducted at baseline, 6 months and one year. RESULTS: Seventy-nine (24.8%) patients presented rapid cognitive loss over 6 months. The majority were stable at one year whereas 15 experienced continued rapid cognitive loss. Multivariate analysis showed that only the Mini Nutritional Assessment score (MNA) was correlated with rate of decline. Patients with rapid cognitive decline were also significantly more dependent at 6 months. CONCLUSIONS: Our findings demonstrate that rapid cognitive loss is frequent in AD patients, probably indicating underlying frailty. Future studies should lead to a practical approach to detecting these frail patients and to increasing preventive interventions.

Activities of Daily Living↗
PubMed2004

Factors affecting the concentrations of lead in British wheat and barley grain.

The entry of Pb into the food chain is of concern as it can cause chronic health problems. The concentration of Pb was determined in cereal grain samples collected representatively from British Cereal Quality Surveys in 1982 and 1998 (n = 176, 250 and 233 for wheat collected in 1982 and 1998, and barley in 1998, respectively). In addition, paired soil and grain samples were collected from 377 sites harvested across Britain in 1998-2000. Wheat grain Pb ranged from below the analytical detection limit (0.02 mg kg(-1) dry weight, DW) to 1.63 mg kg(-1) DW, and barley grain Pb from <0.02 to 0.48 mg kg(-1) DW. The vast majority of samples (>99% for both wheat and barley, excluding Scottish barley samples collected in 2000) were well below the newly introduced EU limit for the maximum permissible concentration of Pb in cereals (0.2 mg kg(-1) fresh weight, equivalent to 0.235 mg kg(-1) DW). There was a significant reduction in wheat grain Pb in the 1998 survey compared with the 1982 survey. However, 40 barley samples collected from Scotland in 2000 in the paired soil and crop survey showed anomalously high concentrations of Pb, with 10 samples exceeding the EU limit. Washing experiments demonstrated that surface contamination, introduced during grain harvest and/or storage, was the main reason for the high concentrations in these samples. In the paired soil and crop surveys, there were no significant correlations between grain Pb concentrations with total soil Pb and other soil properties, indicating low bioavailability of Pb in the soils and limited uptake and transport of Pb to grain. The Pb in cereal grain is likely to originate mainly from atmospheric deposition and other routes of surface contamination during harvest and storage.

Environmental Pollution↗
PubMed2004

[Preventive practice in general medicine in the Rhone-Alps region].

The Fifth Health Conference in the Rhone-Alps which took place in early 2001 provided the ideal opportunity and forum for holding a debate about prevention in ambulatory care. In order to provide arguments supporting a wider basis for reflection, the Regional Department of Social and Health Affairs in the Rhone-Alps initiated a study focusing on preventive practices of general practitioners in various areas such as vaccination follow-up procedures; care provided to the elderly; gynaecology, life styles and additions (alcohol, tobacco, and drugs). Utilising the network of the Association for the Development of Medical Information (A.D.I.M.), a representative sample of 80 general practitioners working in the Rhone-Alps region was constituted, which allowed for the inclusion of 3,658 patients from July to December 2000. Results show a distortion between objective preventive practices measured with different physicians' activity scores in the aforementioned areas and the estimated level of effectiveness determined from individual physician's statements. The subsequent calculation of these scores, based on a large sample of patients with similar characteristics to the general population, provide an objective reality from the care consumer's perspective: there is an overall lack of prevention on the part of physicians. The physicians themselves cite the lack of time; an inadequate system of payment and insufficient training as causes for this situation. The implementation of an economic incentive system could facilitate the development preventive practice in general medicine and ambulatory care.

Adult↗
PubMed2003

[Refixation of osteochondral fragments using absorbable implants. First results of a retrospective study].

An osteochondral lesion in a weight bearing joint causes therapeutic problems. Surgical therapy focuses on the restoration of the articular surface, unlimited motion of the joint and prevention of cartilaginous degeneration. A causal therapy to prevent posttraumatic osteoarthritis is the fixation of osteochondral fragments. Various absorbable implants for the purpose of refixation are available, but only a few have proved to be biocompatible. This retrospective study presents the preliminary results after refixation of osteochondral fragments of the ankle and knee joints. We used self-reinforced absorbable pins, nails and screws made of polylactide acid. The results for 15 patients with 17 fractures of 16 joints were evaluated. All patients were scored by the Tegner-activity-level, the McDermott-score and the DGKKT-score, and 13 of them were monitored by postoperative magnetic resonance imaging (MRI). The follow-up extended for an average of 14.3 months (range: 4-43 months). The clinical results for all patients were good (McDermott-score: Ø 89 points, DGKKT-score: Ø 78.8 points, Tegner: pre-op vs post-op=Ø 4.6 vs Ø 5.1) and the surgical therapy proved to be successful. The MRI showed the complete incorporation and vitality of the fragment as well as a congruence of the joint surface. The clinical course and the MRI gave little reference to an inflammatory reaction due to the implants that complicated the course of two patients. These results indicate that absorbable implants made of polylactide acid are biocompatible and effective in the fixation of osteochondral fragments.

Absorbable Implants↗
PubMed2003

[Results of palmar T-plate osteosynthesis in unstable fractures of the distal radius].

For unstable fractures of the distal radius, the dorsal plate requires exposure of the fragments, frequently spongioplasty, and usually removal of the implant later on. However, with the palmar approach for the reconstruction of the articular surface and restoration can easily be achieved with the T-plate. In the Traumatology Department of the University at Göttingen, we have gained experience in the treatment with the palmar T-plate in more than 400 patients. In a prospective study, we investigated the functional and radiological results after palmar T-plate osteosynthesis in Colles fractures. From September 1994 to December 1998 we treated 200 patients with the palmar T-plate (AO, 3.5 mm, titanium). 166 patients (83%), mean age 59 years, could be followed up >18 months. AO classification: A2:10, A3:45, B1:18, B2:10, C1:24, C2:40, C3:19. We compared group 1 (younger than 60 years, n=88) vs group 2 (older than 60 years, n=78). The patients' evaluation of the usability of the hand was normal in 56% and in 26,5% slightly reduced. 12,5% felt handicapped and 5% felt severely handicapped. 5% of the patients changed the domain hand, 15,4% at least partly. Function according to Lidström: 23% excellent, 58% good, 15% fair and 4% poor results. Radiological results according to Lidström were excellent and good in 88,3% and fair in 11,7%. Gartland and Werley score was excellent in 66%, good in 24%, fair in 6% and poor in 4%. There was no significant difference between group 1 and group 2 in the age-depending results. The secondary dislocation, the average dorsal tilt was 3 degrees, the mean shortening of the radius was 1,5 mm. We saw steps in the joint surface from 0,5-1 mm in 10%. An algodystrophy occurred in 5%. 12% of the patients complained of limited sensitive irritations of the medianus nerve most likely originating in the formerly used approach close to the medianus nerve. After changing this approach, we saw no irritation of the Nervus medianus among 50 patients so far. Evaluation of the functional and radiological investigations: The palmar T-plate has produced reliable and good results in the treatment of unstable distal fractures of the radius without angle-stable screws up to now. This type of osteosynthesis is stable for exercise and ensures early mobilization with good functional results even in elderly patients.

Adolescent↗
PubMed2003

[Rapid loss of the Mini Mental State Examination: REAL.FR study].

BACKGROUND: Alzheimer's disease is a chronic pathology requiring regular follow-up. The predictive factors of rapid cognitive decline remain unclear. OBJECTIVES: To analyse the baselines characteristics of patients at increased risk of rapid cognitive decline. METHODS: This study presents transversal data on a community-based sample of 340 patients diagnosed with probable Alzheimer's disease and followed by REAL.FR group. Rapid cognitive decline was defined as a 3-points or greater loss on the Mini Mental State Examination (MMSE) within six months. RESULTS: 54% of patients presented a rapid cognitive decline. Logistic regression analysis showed a positive association between rapid cognitive decline and a MMSE < or = 20 (p < 0.003) or a greater BMI (p < 0.02) and a tendency towards a negative correlation with anxiety (p = 0.06) and negative correlation with the burden severity (p < 0.05). CONCLUSIONS: Patients with a worse cognitive status, a greater BMI and less anxiety or burden were at increased risk of rapid cognitive decline. Future studies should focus on determining etiologies for patients with rapid cognitive loss and help clinicians target these patients for interventions aiming to delay or stabilise the course of this disease.

Aged↗
PubMed2001

An evaluation of the infraclavicular block via a modified approach of the Raj technique.

UNLABELLED: Infraclavicular plexus block has recently become a technique of increasing interest. However, no approach has provided easily identifiable landmarks, good conditions for catheter placement, and lack of complications (mainly pneumothorax). We describe a modified approach of the Raj technique based on the identification of the anterior acromial process, jugular notch, and emergence of the axillary artery within the axillary fossa, with the arm abducted to 90 degrees and elevated by approximately 30 degrees. We evaluated the clinical characteristics of this approach by injecting 40 to 50 mL of ropivacaine 0.6% in 150 patients scheduled for elective surgery of the forearm, wrist, or hand. Success was defined as a sensory block of the 5 nerves with territories distal to the elbow within 30 min after performing the block. The success rate was 97% when a distal response (flexion or extension of the wrist or fingers) was elicited and 44% when a proximal (contraction of the triceps, biceps) was obtained using a nerve stimulator. Complications were rare: aspiration of blood was seen in 2% of patients and hematoma was seen at the puncture site in 0.6%; no pneumothorax occurred. Eleven patients (7%) complained of some pain during the procedure. We conclude that the modified approach of the Raj technique for infraclavicular block is very effective when a distal nerve stimulator response is obtained with a small complication rate and a high degree of patient satisfaction. IMPLICATIONS: We describe a modified approach of the Raj technique for the infraclavicular brachial plexus. The elicitation of a distal nerve stimulator response is associated with a high success rate, a low incidence of complications and a high degree of patient satisfaction.

Amides↗
PubMed2001

[Psychometric properties of a psychological well-being test for people with physical impairments].

Measuring the psychological well-being of people with physical impairments could provide relevant information to occupational therapists. The aim of this study was to verify psychometric properties of a psychological well-being test called Test de personnalité PER (PER). This test was administered to two samples of people with physical impairments. Two time measurements were collected within a group of 36 individuals and one single measure within another group of 79 individuals. Comparisons between time measurements, between groups and with the normative group of the PER were performed in an attempt to verify the sensitivity, the capacity to discriminate between known groups, and the construct validity of the PER. One section of the Sickness Impact Profile measuring psychological well-being was administered to the same groups to verify the concurrent criterion validity of the PER. The results indicate that the PER has sufficient psychometric qualities.

Persons with Disabilities↗
PubMed2001

[Regionalization of rehabilitation services. Survey of users of a Quebec center].

OBJECTIVE: To understand the situation of and difficulties encountered by users of a supraregional rehabilitation institute when they are transferred from the institute to facilities in their own regions, and to discover how they address these difficulties. DESIGN: Qualitative descriptive study. SETTING: Regions in Quebec served by a physical rehabilitation institute (Institut de réadaptation en déficience physique de Québec). PARTICIPANTS: Thirty-nine people who used services at the institute and then sought rehabilitation in their own regions. METHOD: Telephone survey using a validated questionnaire with both open-ended and closed questions. MAIN FINDINGS: About 69% of users had difficulty obtaining adequate follow up in their regions; the regions lacked professionals with expertise; more efficient methods of communication are required; and physicians' role in providing continuity of care needs to be recognized. CONCLUSION: Providing continuity of care on a regional basis is a formidable challenge for the entire health and social services network, but ways of meeting this challenge are within reach.

Adolescent↗
PubMed2000

Caspase-independent commitment phase to apoptosis in activated blood T lymphocytes: reversibility at low apoptotic insult.

Little is known about the mechanisms of programmed death triggered in T lymphocytes by stimuli that can bypass caspase activation. Anti-CD2 monoclonal antibody and staurosporine are such apoptosis inducers because they operate in the presence of broad-spectrum caspase inhibitors BOC-D.fmk and Z-VAD.fmk. A system was devised, based on the isolation according to density of activated blood T cells progressively engaged in the apoptotic process. This allowed definition of a sequence of caspase-dependent and caspase-independent apoptogenic events that are triggered by anti-CD2 and staurosporine. Thus, a commitment phase to apoptosis was defined that is entirely caspase independent and that is characterized by cell volume loss, partial chromatin condensation, and release into the cytosol and the nucleus of mitochondrial "apoptosis-inducing factor " (AIF). Committed cells were viable, displayed a high mitochondrial inner transmembrane potential (triangle upPsim), and lacked large-scale and oligonucleosomal DNA fragmentation. Mitochondrial release of AIF was selective because cytochrome c was retained in mitochondria of the very same cells. Mitochondrial release of cytochrome c occurred later, at the onset of the execution phase of apoptosis, concurrently with triangle upPsim collapse, poly (ADP-ribose) polymerase cleavage, and DNA fragmentation. The apoptogenic events of this commitment phase are reversible if the strength of the stimulus is low and of short duration.

Apoptosis↗
PubMed2000

Conceptual apraxia and semantic memory deficit in Alzheimer's disease: two sides of the same coin?

This study was designed to examine the patterns of apraxic disturbances and the relationships between action knowledge and other measures of semantic knowledge about objects in 10 well-characterized Alzheimer's disease (AD) patients. Five tasks were used to assess components of action knowledge (action-tool relationships, pantomime recognition, and sequential organization of action) and praxis execution (actual use, pantomiming) according to the cognitive model of praxis. Three tasks (verbal comprehension, naming, and a visual semantic matching task) were used to assess verbal-visual semantics. Considering patterns of apraxia first, conceptual apraxia was found in 9 out of the 10 AD patients, suggesting that it is a common feature even in the early stages of AD. Second, we found partly parallel deficits in tests of action-semantic and verbal-visual semantic knowledge in 9 AD patients. Impaired action knowledge was found only in patients with a semantic language deficit. These findings provide no evidence that "action semantics" may be separated from other semantic information. Our results support the view of a unitary semantic system, given that the representations of action-semantic and other semantic knowledge of objects are often simultaneously disrupted in AD.

Aged↗
PubMed2000

Relationship between cognitive capabilities and social participation among people with traumatic brain injury.

This study attempts to determine the relationship between cognitive capabilities and social participation, over a 1-year period, among people who have experienced traumatic brain-injury (TBI). Using the Disability Creation Process as a basis for making hypotheses, three research questions were examined: (1) Do cognitive capabilities improve over time?; (2) Does social participation improve over time?; and (3) Are these two concepts related over time? The results and their clinical implications on rehabilitation are discussed, along with the limitations of this study.

Adolescent↗