Biomedical subjects

E Martin

Publications and source records attributed to E Martin.

At least 19 recordsLinked to original sources

PubMed2006

Brain activation during mental rotation in school children and adults.

Mental rotation is a complex cognitive skill depending on the manipulation of mental representations. We aimed to investigate the maturing neuronal network for mental rotation by measuring brain activation in 20 children and 20 adults using functional magnetic resonance imaging. Our results indicate that brain activation patterns are very similar between children and adults. However, adults exhibit stronger activation in the left intraparietal sulcus compared to children. This finding suggests a shift of activation from a predominantly right parietal activation in children to a bilateral activation pattern in adults. Furthermore, adults show a deactivation of the posterior cingulate gyrus and precuneus, which is not observed in children. In conclusion, developmental changes of brain activation during mental rotation are leading to a bilateral parietal activation pattern and faster performance.

Adult↗

PubMed2006

Responsiveness to inhaled NO in isolated-perfused lungs from endotoxin-challenged rats is dependent on endogenous nitrite/nitrate synthesis.

BACKGROUND AND OBJECTIVES: In isolated-perfused lungs of lipopolysaccharide (LPS)-challenged rats, vasodilatation to inhaled nitric oxide (NO) is impaired. Inhibition of nitric oxide synthase 2 (NOS2) by aminoguanidine (AG) prevented hyporesponsiveness to inhaled NO. Here, we investigated whether NOS2-mediated nitrite/nitrate synthesis modulates responsiveness to inhaled NO. METHODS: Sprague-Dawley rats received intraperitoneally 0.5 mg kg(-1) LPS. Four hours later, LPS-treated rats received 3, 10 or 30 mg kg(-1) AG or 0.01, 0.1 or 1 mg kg(-1) S-methylisothiourea (SMT) by intraperitoneal injection. Sixteen to eighteen hours later, lungs were isolated and perfused, and pulmonary artery pressure (PAP) was elevated by 6-8 mmHg using the thromboxane analogue U46619. The decrease of PAP in response to inhaled NO and nitrate/nitrite levels in serum and perfusate was measured. RESULTS: In rats treated with LPS alone or 0.01 or 0.1 mg kg(-1) SMT, 40 ppm NO decreased PAP less than in rats treated with AG and 1 mg kg(-1) SMT (-1.8 mmHg (95% confidence interval: -1.5 to -2.1) vs. -6.0 mmHg (-5.7 to -6.3), P < 0.01). Improved NO responsiveness was associated with lower serum and perfusate nitrite/nitrate levels than in rats with hyporesponsiveness to inhaled NO (102 micromol (82-122) vs. 282 micromol (261-303) and 8.1 micromol (6.9-9.3) vs. 19.8 micromol (17.2-22.4), respectively, P < 0.01). CONCLUSIONS: These observations demonstrate that in isolated-perfused lungs of LPS-treated rats, NOS2 inhibition improved responsiveness to inhaled NO. Here, responsiveness to inhaled NO is dependent on the ability of NOS2 inhibitors to reduce nitrite and nitrate levels in serum and released in the lung.

Administration, Inhalation↗

PubMed2006

[The reversed dermis flap soon to be forgotten as a major filler?].

In his paper entitled "The reversed dermis flap" published in 1978, Pakiam explained the advantages of de-epithelialising local flaps and applying them dermis-side down. We present a ten-year series of 107-reversed dermis flaps used to raise depressed scars. There have been no significant complications in this series except two cases of infection and six cases of postoperative haematoma. All patients were satisfied with the cosmetic outcome. We do not use this flap as much as we used to since Coleman demonstrated how efficient lipostructure could be especially when applied to thin depressed scars. The reversed dermis flap remains invaluable in cases of widespread scars or when lipostructure is dangerous or impossible.

Dermis↗

PubMed2006

[Malnutrition in pediatric oncology: prevalence and screening].

UNLABELLED: Algorithms for nutritional pediatric support have been proposed in a French national nutritional framework program. However, they are not specific for oncology. With the pediatric nutritional risk score (PNRS) all children with cancer have a high risk of malnutrition, but a systematic nutritional support is not possible for all of them. AIM: Estimation of malnutrition prevalence and identification of predictive factors of major weight loss during treatment defined by a weight loss more than 5% within 1 month, 7.5% within 3 months, 10% within 6 months. POPULATION AND METHODS: This historical study included children registered with a solid tumor in 2002 in an oncology pediatric unit. Data collected at diagnosis were weight, height, PNRS, the Lansky functional score, tumor type. Furthermore weight, height, and major weight loss were collected at each cure of chemotherapy and during evolution. Malnutrition at diagnosis was defined using the weight for height ratio. Relations between major weight loss and risks factors were estimated using logistic regression. RESULTS: Seventy children were included, 16 (22.9%) were malnourished at admission. During chemotherapy, 29 (41.4%) children experienced a major weight loss. Odds ratio of those who were malnourished at diagnosis was not significantly higher in comparison to well-nourished children. Children with a high risk of malnutrition are those affected by Ewing tumor, B lymphom, head and neck localisations, osteosarcomas, metastatic cancers, or cancers treated by high dose chemotherapy with stem cell rescue. For these 29 (41.4%) children the major weight loss odds ratio was 5.9 [IC95% 2.0-16.7]. CONCLUSION: Taking into account others factors with items of PNRS allows to screen children with an higher risk of a major weight loss during treatment and to enhance nutritional care plan for them.

Adolescent↗

PubMed2006

[Central venous totally implantable access for high dose chemotherapy in children].

BACKGROUND: The feasibility and complication rate of central venous totally implantable access ports (TIAP), used for delivering high-dose chemotherapy (HDC) with autologous stem cell transplantation, have not been fully investigated to date, due to the almost exclusive use of external catheters (EC) in this clinical setting. PATIENTS AND METHODS: We retrospectively studied infectious and mechanical complications of 45 TIAP and 19 EC, in 64 children receiving HDC and autologous stem cell transplantation at the Centre Leon-Berard (Lyon) or at the oncology unit of Toulouse children hospital between January 1999 and December 2003. RESULTS: From the beginning of intensification to 60 days after bone marrow transplantation, 7 catheter-related bloodstream infections (3/19 EC or 15.8% corresponding to 2.69 infections for 1000 days of observation; 4/45 TIAP or 8.9% corresponding to 1.38 infections for 1000 days of observation) and 2 local infections (1/45 TIAP; 1/19 EC) were reported. Seven cases of reversible obstruction (6/7 with TIAP) and no deep venous thrombosis were detected. In 7 cases, another venous access was required either for accidental removal (2 EC), catheter infection (2 TIAP), or admission to intensive care (2 TIAP, 1 EC). TIAP complication rate does not seem to be influenced by factors such as low weight, massive blood product transfusion or prolonged parenteral nutrition. In 8 children, TIAP were used for collection of hematopoietic progenitor cells. CONCLUSIONS: The use of TIAPs appears as a safe and effective option for HDC. We found more mechanical complications but less infectious complications with TIAP than with EC. Nevertheless, results need to be validated prospectively in a larger study cohort.

Adult↗

PubMed2006

Adenosine-induced cardiac arrest and EEG changes in patients with thoracic aorta endovascular repair.

BACKGROUND: We studied haemodynamic and metabolic variables, and cerebral function after cardiac arrest induced by high dose of adenosine in patients undergoing thoracic aorta endovascular repair. METHODS: Arterial blood pressure, blood gas values and EEG were recorded continuously in 15 patients undergoing anaesthesia (isoflurane) for endovascular thoracic aorta repair. Cardiac arrest was induced by different doses of adenosine (Adrekar, Sanofi-Synthelabo, Berlin, Germany; 0.4-1.8 mg kg(-1) body weight). Serum concentrations of neurone-specific enolase (NSE) were determined before and after stent graft implantation. Neurological function was assessed before and after surgery. RESULTS: After adenosine, the heart beat stopped immediately for 18-58 s in close relation to the adenosine dose. EEG power was significantly reduced to -57%, but reached normal values within 5 min after cardiac arrest. In particular, the fast alpha- and beta-EEG-frequencies sensitively reflected patients' EEG activity during the procedure. No intraoperative increases in NSE concentrations, and no neurological dysfunctions after surgery, were observed. CONCLUSION: After adenosine-induced cardiac arrest, changes in haemodynamic variables and EEG power spectra reversed completely within 1 and 5 min, respectively, without persistent brain dysfunction after stent graft implantation.

Adenosine↗

PubMed2006

[Importance of anesthesia in multimodal oncologic therapeutical concepts].

Patients with malignant diseases are increasingly being treated with multimodal therapeutical concepts based on the three major modalities surgery, radiotherapy and chemotherapy. The perioperative period is crucial within this multimodal concept as the prognosis of patients may be directly influenced by perioperative measures. In addition, it is of major importance to avoid complications in the perioperative phase, as these might worsen the prognosis of the patient and in order to prevent a delay in the beginning of planned adjuvant therapies. These aspects demonstrate the important role of anesthesia in the treatment of patients with cancer. Further studies defining the relevance of anesthesiologic measures in oncologic patients are needed.

Aged↗

PubMed2006

[Spectrum of patients in prehospital emergency services. What has changed over the last 20 years?].

BACKGROUND: In Germany the physician staffed emergency systems have announced an increase in rescue missions over the years. The aim of this study is to analyse the development of the spectrum of patients in an emergency system over the last 20 years in order to highlight the significant changes. METHODS: In a retrospective study we analyzed the prehospital chart views from 2004, 1992 and 1984 with respect to patients' demography, type of rescue mission, degree of internal disease or injury (NACA), state of consciousness (GCS), as well as prehospital interventions performed by prehospital emergency physician. RESULTS: In 2004 (3,825), the absolute number of missions was 2 and 4 times higher than 1992 (2,114) and 1984 (957), resp. In all of these investigated time periods non-trauma missions (74%; 2,812 vs. 66%; 1,390 vs. 51%; 485) were leading, followed by trauma missions (18%; 690 vs. 22%; 464 vs. 39%; 375), aborted missions (3%; 126 vs. 7%; 154 vs. 6%; 56), and dead on arrival (5%; 197 vs. 5%; 106 vs. 4%; 41). Although, the percentage of patients with NACA IV-VI (39% vs. 50%) or patients with GCS < or =8 (18% vs. 34%) was lower in 2004, the absolute number of patients in each category was higher than in 1984 (NACA IV-VI: 1,434 vs. 448, p<0.01; GCS: 672 vs. 303, p<0.01). CONCLUSIONS: The results of this study demonstrate, that the percentage of trauma, severely ill/injured or unconscious patients is lower than in previous years. However, the higher absolute numbers of patients demonstrate that the emergency physician now encounters more critically ill/injured, unconscious and trauma patients. It does not seem necessary to question the qualifications for an emergency physician, which have previously been considered essential for the management of acute life-threatening situations.

Consciousness Disorders↗

PubMed2006

[Postoperative ileus. Pathophysiology and prevention].

Continuous improvements in surgical technique and anaesthesia for ileus have resulted in a significant reduction of perioperative complications. Postoperative outcome of surgical patients is increasingly dependent on the severity of postoperative ileus, which often determines morbidity and length of hospital stay. In the present article we discuss possible variables influencing this disease. Furthermore, means of prevention and therapeutic strategies for postoperative ileus are briefly presented.

Abdomen↗

PubMed2006

[Incidence and mortality of central nervous system tumors in France: trends over the period 1978-2000 and influence of registration practices on results].

BACKGROUND: In France, cancer incidence figures are produced by cancer registries covering only 13.5% to 16% of the whole population of the country. Thus, to produce national figures, estimates have to be computed. Registration disparities between registries concerning tumors of the Central Nervous System (CNS) could have biased these estimates. METHODS: National estimates are based on modelling of the incidence/mortality ratio. The most recent estimations for year 2000 were calculated by the French Cancer Registry Network (FRANCIM) and the department of biostatistics of Lyon University Hospital. Since benign tumors are not recorded in some cancer registries, a new estimate of the incidence of CNS tumors was produced by estimating the number of benign tumors in these registries. RESULTS: In 2000 in France, the number of estimated cases of CNS tumors was 2697 in men and 2602 in women, with incidence rates (World standard) of 7.4 and 6.4 per 100,000 respectively. The incidence increased between 1978 and 2000, on an average by 2.25% per year in men and 3.01% per year in women. However, these estimates do not provide a correct picture of CNS incidence. First of all, pathological diagnoses are not performed in 3.5%-27.5% of the patients with CNS tumors registered in French registries. Second, figures for benign tumors (mainly meningiomas) were provided by only two of nine cancer registries. If benign tumors had been registered by all cancer registries, computed incidence would have increased by 12% for men and 26% for women. CONCLUSION: Incidence of CNS tumors is increasing in France, as in many other countries. To improve comparability with other countries, French cancer registries should also collect data on benign tumors. The discrepancies observed between registries in the proportion of patients without information on histology show differences in diagnostic practices and should be the starting point for a survey on this topic.

Aged↗

PubMed2006

How depth of anesthesia influences the blood oxygenation level-dependent signal from the visual cortex of children.

BACKGROUND AND PURPOSE: Functional MR imaging (fMRI) is playing an important role in investigations of cortical development and maturation. Functional MR imaging in young children or infants frequently involves measuring a clinical population under sedation or anesthesia. We examined the effect of depth of anesthesia on the extent and amplitude of the blood oxygen level-dependent (BOLD) response. METHOD: We performed BOLD-based fMRI on a visual stimulus flickering at 8 Hz at sevoflurane concentrations of 0.5 minimum alveolar concentration (MAC), 0.75 MAC, and 1.0 MAC, on 16 children at least 5 years of age. We determined the extent of activation by counting the number of activated voxels and assessed the change in the local deoxyhemoglobin concentration by comparing DeltaR2*. RESULTS: The number of activated voxels of the positive BOLD response was higher at 0.75 MAC than at 0.5 MAC or 1.0 MAC. The magnitude of their mean DeltaR2* steadily declined as the level of sevoflurane was increased from 0.5 MAC to 1.0 MAC. The extent of activation of the negative BOLD response declined progressively from 0.5 MAC to 1.0 MAC. The magnitude of their mean amplitude of the DeltaR2* did not change with sevoflurane concentrations. The change in the extent of activation and the magnitude of DeltaR2* when the concentration of sevoflurane increased from 0.5 MAC to 0.75 MAC was due to its vasodilative property. The change in the extent of activation and the amplitude of DeltaR2* following the increase in the concentration of sevoflurane from 0.75 MAC and 1.0 MAC was due to its anesthetic property. This was the case for both the positive and negative BOLD response. CONCLUSIONS: Careful adjustment of anesthetic depth can be used advantageously when performing BOLD-based fMRI measurements in children.

Adolescent↗

PubMed2006

Sublingual vaccines based on wild-type recombinant allergens.

Sublingual immunotherapy (SLIT) represents a non invasive alternative to subcutaneous immunotherapy in order to treat type I allergies. Vaccines based on recombinant allergens expressed in a native (i.e. wild-type) configuration, formulated with ad hoc adjuvants designed to target Langerhans cells in the sublingual mucosa should allow to induce allergen-specific regulatory T cells. In this context, we have developed animal and human preclinical models to test the capacity of candidate vaccines to modulate selectively allergen-specific T helper lymphocyte polarization following sublingual vaccination.

Adjuvants, Immunologic↗

PubMed2005

A 6-month assessment of bimatoprost 0.03% vs timolol maleate 0.5%: hypotensive efficacy, macular thickness and flare in ocular-hypertensive and glaucoma patients.

AIM: To compare 6 months of treatment with bimatoprost and timolol in terms of their hypotensive efficacy and secondary effects, including changes in macular thickness and the inflammatory reaction induced in the anterior chamber. METHODS: A prospective, randomized, parallel-group trial performed on 30 eyes of 30 patients per group. The main outcome measure was the difference between the IOP value taken between the baseline visit and the 6-month-visit. Macular thickness determined through optical coherence tomography and anterior chamber inflammation estimated using the laser flare meter was also evaluated. Adverse events were recorded during the study period. RESULTS: Bimatoprost treatment gave rise to a significantly lower mean IOP than timolol in all follow-up visits as from the first month (P<0.05). Bimatoprost achieved high percentage IOP reductions from baseline in a significantly higher proportion of patients (P<0.05). Macular thickness and anterior chamber flare failed to vary significantly both between the two groups and within each group during the 6-month evaluation (P>0.05). CONCLUSIONS: Bimatoprost 0.03% once daily showed a greater efficacy then timolol 0.05% twice daily in patients with elevated IOP. No significant differences were detected in macular thickness or anterior uveitis using optical coherence tomography and laser flare photometry.

Adult↗

PubMed2005

[Coverage of pelvis and thigh region by pedicled perforator flap like deep inferior epigastric perforator (DIEP)].

The deep inferior epigastric perforator flap (DIEP) is a variation of the transverse rectus abdominis myocutaneous flap (TRAM). This flap was used as a pedicled flap to reconstruct the pelvis and thigh region after resection for cancer (four cases). Various flaps have been described for covering theses tissue defects but we prefer this perforator flap for its many advantages. This flap is very reliable and generates minimal functional sequelae on donor site. This flap is useful to cover soft tissue defects after vascular and oncologic surgery, a situation that was rarely reported to our knowledge.

Adult↗

PubMed2005

[Newly immigrant adolescents health and quality of life in Belgium: screening and prevention in school medicine].

OBJECTIVES: Little is known so far about the health of newly immigrant adolescents. The present study aimed to evaluate their health and quality of life (QoL) and to reinforce prevention and health promotion in school medicine. METHODS: One hundred and fifty-eight adolescents (mean age: 15,4 years) from 37 nationalities were included in the study in two health centers in Brussels. This study was carried out by medical records analysis and administration of a questionnaire about health and QoL (VSP-A) in several languages. RESULTS: The results showed adolescents in good physical health. Nevertheless their quality of life deteriorated over time in Belgium. The QoL was significantly lower for adolescents without social support: 48,0 (SD=13,5) vs 60,6 (SD=11,1) compared with adolescents with social support - i.e. with one resource person - on a scale from 0 to 100. Adolescents had many subjective health problems, like "the future" cited by half of them. CONCLUSION: This study shows the importance of developping a specific approach to newly immigrant adolescents health and the contribution of school medicine in the identification of biological, psychological and social needs and hightlights the preventive answers carried out by school medicine.

Adolescent↗

PubMed2005

Leukoencephalopathy with ataxia, hypodontia, and hypomyelination.

The authors describe four unrelated girls with a distinctive neurologic disorder with early-onset progressive ataxia and hypodontia with a characteristic pattern of delayed dentition. Cerebral MRI shows hypomyelinated white matter and cerebellar atrophy; 1H-MRS of white matter reveals a marked elevation of myo-inositol.

Age of Onset↗

PubMed2005

Calculations of dose distributions using a neural network model.

The main goal of external beam radiotherapy is the treatment of tumours, while sparing, as much as possible, surrounding healthy tissues. In order to master and optimize the dose distribution within the patient, dosimetric planning has to be carried out. Thus, for determining the most accurate dose distribution during treatment planning, a compromise must be found between the precision and the speed of calculation. Current techniques, using analytic methods, models and databases, are rapid but lack precision. Enhanced precision can be achieved by using calculation codes based, for example, on Monte Carlo methods. However, in spite of all efforts to optimize speed (methods and computer improvements), Monte Carlo based methods remain painfully slow. A newer way to handle all of these problems is to use a new approach in dosimetric calculation by employing neural networks. Neural networks (Wu and Zhu 2000 Phys. Med. Biol. 45 913-22) provide the advantages of those various approaches while avoiding their main inconveniences, i.e., time-consumption calculations. This permits us to obtain quick and accurate results during clinical treatment planning. Currently, results obtained for a single depth-dose calculation using a Monte Carlo based code (such as BEAM (Rogers et al 2003 NRCC Report PIRS-0509(A) rev G)) require hours of computing. By contrast, the practical use of neural networks (Mathieu et al 2003 Proceedings Journees Scientifiques Francophones, SFRP) provides almost instant results and quite low errors (less than 2%) for a two-dimensional dosimetric map.

Algorithms↗

PubMed2005

Multitensor approach for analysis and tracking of complex fiber configurations.

A multidiffusion-tensor model (MDT) is presented containing two anisotropic and one isotropic diffusion tensors. This approach has the ability to detect areas of fiber crossings and resolve the direction of crossing fibers. The mean diffusivity and the ratio of the tensor compartments were merged to one independent parameter by fitting MDT to the diffusion-weighted intensities of a two-point data acquisition scheme. By an F-test between the errors of the standard single diffusion tensor and the more complex MDT, fiber crossings were detected and the more accurate model was chosen voxel by voxel. The performance of crossing detection was compared with the spherical harmonics approach in simulations as well as in vivo. Similar results were found in both methods. The MDT model, however, did not only detect crossings but also yielded the single fiber directions. The FACT algorithm and a probabilistic connectivity algorithm were extended to support the MDT model. For example, a mean angular error smaller than 10 degrees was found for the MDT model in a simulated fiber crossing with an SNR of 80. By tracking the corticospinal tract the MDT-based tracks reached a significantly greater area of the gyrus precentralis.

Algorithms↗