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Biomedical subjects

P Michel

Publications and source records attributed to P Michel.

At least 19 recordsLinked to original sources
PubMed2007

Reliability of the pulp nail bone (PNB) classification for fingertip injuries.

Evans and Bernardis proposed the 'PNB classification', by which a fingertip injury is classified according to each structure: pulp P, nail N, bone B. The objective of this study was to assess the inter-observer reliability, repeatability and accuracy of PNB. One hundred patients presenting with a fingertip injury were included prospectively, photographed, then classified in randomly chosen orders by nine independent observers. A third were drawn randomly and classified a second time to measure repeatability. A reference classification was also provided by one of the authors of the PNB system. Classifications agreed with the reference in 59% of injuries for P, 55% for N and 54% for B. The Kappa values for inter-observer agreement were 0.520 for P, 0.512 for N, and 0.504 for B; for intra-observer agreement, they were 0.616 for P, 0.658 for N, and 0.577 for B. Although levels of agreement are comparable with results found for other classifications, they are insufficient for use of the PNB classification without improvement.

Adolescent↗
PubMed2006

Induction cisplatin-irinotecan followed by concurrent cisplatin-irinotecan and radiotherapy without surgery in oesophageal cancer: multicenter phase II FFCD trial.

A recent phase I study showed that weekly cisplatin, irinotecan and concurrent radiotherapy can be administered with moderate toxicity in patients with oesophageal cancer. Patients with no prior treatment and oesophageal cancer stage I to III, performance status <3, caloric intake >1,500 kcal day(-1) were included. Chemotherapy, with cisplatin 30 mg m(-2) and irinotecan 60 mg m(-2), was administered at days 1, 8, 22, 29, and concurrently with radiotherapy at days 43, 50, 64 and 71. Radiotherapy was delivered with 50 or 50.4 Gy in 25 fractions/5 weeks. Forty-three patients were included, 10 stage I, 19 stage II and 14 stage III. Mean age was 59.2 years (range 44-79). A total of 30 out of 43 (69.8%) patients underwent all planned treatment. During induction chemotherapy, 14 severe toxicities of grade 3 or 4 in 10 patients (23.3%) were reported with 57.1% due to haematoxicity. During chemoradiotherapy, 31 severe toxicities of grade 3 or 4 with 64.5% due to haematotoxicity were reported in 18 patients. One toxic death occurred (diarrhoea grade 4). The complete clinical response rate was 58.1% (95% CI: 43.4-72.8%). Overall survival rate at 1 and 2 years was 62.8%, (95% CI, 58.3-77.3%) and 27.9% (95% CI, 13.4-41.3%), respectively. In conclusion, cisplatin-irinotecan-radiotherapy is an active and well-tolerated regimen feasible in out-patients.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2006

Radiative damping and electron beam dynamics in plasma-based accelerators.

The effects of radiation reaction on electron beam dynamics are studied in the context of plasma-based accelerators. Electrons accelerated in a plasma channel undergo transverse betatron oscillations due to strong focusing forces. These oscillations lead to emission by the electrons of synchrotron radiation, with a corresponding energy loss that affects the beam properties. An analytical model for the single particle orbits and beam moments including the classical radiation reaction force is derived and compared to the results of a particle transport code. Since the betatron amplitude depends on the initial transverse position of the electron, the resulting radiation can increase the relative energy spread of the beam to significant levels (e.g., several percent). This effect can be diminished by matching the beam into the channel, which could require micron sized beam radii for typical values of the beam emittance and plasma density.

Journal Article↗
PubMed2006

Continuous assessment of electrical epileptic activity in acute stroke.

OBJECTIVE: To determine the incidence and risk factors of electrical seizures and other electrical epileptic activity using continuous EEG (cEEG) in patients with acute stroke. METHODS: One hundred consecutive patients with acute stroke admitted to our stroke unit underwent cEEG using 10 electrodes. In addition to electrical seizures, repetitive focal sharp waves (RSHWs), repetitive focal spikes (RSPs), and periodic lateralized epileptic discharges (PLEDs) were recorded. RESULTS: In the 100 patients, cEEG was recorded for a mean duration of 17 hours 34 minutes (range 1 hour 12 minutes to 37 hours 10 minutes). Epileptic activity occurred in 17 patients and consisted of RSHWs in seven, RSPs in seven, and PLEDs in three. Electrical seizures occurred in two patients. On univariate Cox regression analysis, predictors for electrical epileptic activity were stroke severity (high score on the National Institutes of Health Stroke Scale) (hazard ratio [HR] 1.12; p = 0.002), cortical involvement (HR 5.71; p = 0.021), and thrombolysis (HR 3.27; p = 0.040). Age, sex, stroke type, use of EEG-modifying medication, and cardiovascular risk factors were not predictors of electrical epileptic activity. On multivariate analysis, stroke severity was the only independent predictor (HR 1.09; p = 0.016). CONCLUSION: In patients with acute stroke, electrical epileptic activity occurs more frequently than previously suspected.

Adult↗
PubMed2006

Prior chemoradiotherapy is associated with a higher life-threatening complication rate after palliative insertion of metal stents in patients with oesophageal cancer.

BACKGROUND: Self-expanding metal stents are used routinely to palliate dysphagia due to oesophageal cancer. STUDY AIM: To compare the frequency of life-threatening complications after self-expanding metal stent insertion, depending on whether patients received prior chemoradiotherapy or no treatment. PATIENTS AND METHODS: During 7 years, 116 consecutive patients were treated at a single centre in a palliative intent by insertion of self-expanding metal stent for dysphagia due to an oesophageal cancer. Patients were retrospectively separated into two groups: patients with chemoradiotherapy before self-expanding metal stent insertion (group 1, n = 56) and patients with no treatment before or after self-expanding metal stent insertion (group 2, n = 60). Life-threatening complications were compared and predictive risk factors of postprocedure complications were identified. RESULTS: Median dysphagia was significantly improved during the first month (grade 3 to grade 1 in the two groups). Early and late major complications occurred more frequently in group 1 (23.2% vs. 3.3%; P < 0.002 and 21.6% vs. 5.1%; P < 0.02 respectively). Prior chemoradiotherapy was the only independent predictive factor of postprocedure major complications, with an odds ratio of 5.59 (CI 95% 1.7-18.1). CONCLUSIONS: Life-threatening complications after palliative self-expanding metal stent placement seem to occur more frequently in patients with prior chemoradiotherapy. Prevention of these severe complications should be considered before stenting.

Aged↗
PubMed2006

The use of randomization tests to assess the degree of similarity in PFGE patterns of E. coli O157 isolates from known outbreaks and statistical space-time clusters.

Using isolates from reported cases of Escherichia coli O157 from Alberta, Canada in 2002, we applied randomization tests to determine if cases associated with an outbreak or statistical space-time cluster had more similar pulsed-field gel electrophoresis patterns, based on Dice coefficients, than expected by chance alone. Within each outbreak and space-time cluster, we assessed the mean, median, 25th percentile, 75th percentile, standard deviation, coefficient of variation, and interquartile range of the Dice coefficients of each pairwise comparison among the isolates. To assess the statistical significance of measures of location (e.g. mean) and variation (e.g. standard deviation) we created randomization distributions using all isolates or only isolates from sporadic cases. We determined that randomization tests are an appropriate tool for evaluating the similarity among isolates from cases that have been linked epidemiologically or statistically. We found little difference between using all cases or only sporadic cases when creating our randomization distributions.

Disease Outbreaks↗
PubMed2006

[Ruptured mesenteric aneurysm from Listeria monocytogenes].

Infections due to Listeria monocytogenes usually occur in pregnant women, in elderly or immunocompromised patients. We report the case of an immunosuppressed woman who had been hospitalized for a meningoencephalitis due to L. monocytogenes. She was operated on for an abdominal hemorrhagic shock due to a ruptured mycotic aneurysm of the inferior mesenteric artery. Arterial aneurysms due to this germ are rare and occur on large arteries. Only 17 cases have been previously described in the literature and just one concerning a mesenteric artery.

Aortic Dissection↗
PubMed2006

A comparative longitudinal quality of life study using the Spitzer quality of life index in a randomized multicenter phase III trial (FFCD 9102): chemoradiation followed by surgery compared with chemoradiation alone in locally advanced squamous resectable thoracic esophageal cancer.

BACKGROUND: The aim of the study was to compare the longitudinal quality of life (QoL) between chemoradiation with or without surgery in patients with locally advanced squamous resectable esophageal cancer included in a randomized multicenter phase III trial (FFCD 9102). MATERIALS AND METHODS: All patients with locally advanced resectable (T3-4 N0-1 M0) epidermoid or glandular esophageal cancer (n = 451) received induction chemoradiation. Responders (n = 259) were randomized between surgery (arm A) and continuation of chemoradiation (arm B). The Spitzer QoL Index was scored (0-10) at inclusion and at each follow-up, every 3 months during 2 years. QoL at baseline and longitudinal changes were respectively compared with univariate ANOVA and mixed-model analysis of variance for repeated measurements. The time interval between the follow-up was assessed and the same analyses were performed among survivors with 2 years of follow-up. RESULTS: The squamous histology was predominant in both arms. The mean QoL score decreased between baseline and the first follow-up and between the first and the second follow-ups. QoL scores at the first follow-up were comparatively worse in arm A than in arm B (7.52 versus 8.45, P < 0.01), whereas the longitudinal QoL study showed no difference between treatments (adjusted P = 0.26). Furthermore, the longitudinal QoL was not different (adjusted P = 0.23) among survivors with 2 years of follow-up. CONCLUSIONS: Among patients responding to induction chemoradiation, surgery and continuation of chemoradiation had the same impact on QoL in patients with locally advanced, resectable esophageal cancer although a significantly greater decrease in the Spitzer Index was observed in the postoperative period.

Adenocarcinoma↗
PubMed2006

The use of outbreak information in the interpretation of clustering of reported cases of Escherichia coli O157 in space and time in Alberta, Canada, 2000-2002.

We obtained a list of all reported cases of Escherichia coli O157 in Alberta during the 2000-2002 period, and using scan statistics we identified yearly temporal and spatial clusters of reported cases of E. coli O157 during the summer and in southern Alberta. However, the location of the spatial cluster in the south was variable among years. The impact of using both outbreak and sporadic data or only sporadic data on the identification of spatial and temporal clusters was small when analysing individual years, but the difference between spatial clusters was pronounced when scanning the entire study period. We also identified space-time clusters that incorporated known outbreaks, and clusters that were suggestive of undetected outbreaks that we attempted to validate with molecular data. Our results suggest that scan statistics, based on a space-time permutation model, may have a role in outbreak investigation and surveillance programmes by identifying previously undetected outbreaks.

Alberta↗
PubMed2006

Acute autonomic dysfunction contralateral to acute strokes: a prospective study of 100 consecutive cases.

Complex painful reflex syndrome is sometimes described in the chronic phase of stroke. Acute autonomic dysfunction (AAD), which is occasionally present in cases of acute stroke, has not been studied prospectively. The aim of the study was to investigate AAD on the hemibody contralateral to the lesion in the acute phase of stroke. One hundred consecutive patients (median age +/- interquartile range, 74 +/- 21; range 19-93; 51 women: 80 +/- 17 and 49 men: 70 +/- 17 years) in the acute phase of stroke were studied prospectively. Changes in skin temperature or coloration, diaphoresis, pain, or edema were noted in the first 3 days post-stroke. Associations between AAD and topography (cortical pre- and/or post-central, insular, corona radiata, basal ganglia, internal capsule, thalamus, and brainstem), age, gender, ischemic or hemorrhagic etiology, or the presence of sensorimotor deficits or ataxia were examined using the chi-squared or Fisher's exact test and logistic regression analysis. AAD was found in 71% of the patients and showed a significant positive association with the presence of a lesion in the post-central cortex (P = 0.037), internal capsule (P = 0.005), basal ganglia (P = 0.002), or insula (P = 0.011) and a negative association with the presence of a lesion in the brainstem (P = 0.004). Multivariate logistic regression analysis including all studied topographic variables showed that only brainstem lesions were significantly associated with a decreased risk of developing AAD (odds ratio = 0.08, 95% confidence interval: 0.01-0.69, P = 0.022). AAD was not associated with age, gender, the ischemic or hemorrhagic nature of the lesion, the side of lesion, hypertonic or hypotonic paresis, or hyperreflexia or hyporeflexia. AAD was found in association with sensory deficits (P = 0.001) and contralateral hyperkinesia (P = 0.004). Acute AAD is significantly more likely to occur in the presence of hemispheric lesions involving sensory pathways from the cortex to the internal capsule and insula and is significantly less prevalent in the presence of brainstem lesions.

Acute Disease↗
PubMed2005

Thrombolysis in stroke patients aged 80 years and older: Swiss survey of IV thrombolysis.

This databank-based, multicenter study compared all stroke patients with IV tissue plasminogen activator aged > or = 80 years (n = 38) and those < 80 years old (n = 287). Three-month mortality was higher in older patients. Favorable outcome (modified Rankin scale < or = 1) and intracranial hemorrhage (asymptomatic/symptomatic/fatal) were similarly frequent in both groups. Logistic regression showed that stroke severity, time to thrombolysis, glucose level, and history of coronary heart disease independently predicted outcome, whereas age did not.

Age Factors↗
PubMed2005

[Interventional neuroradiologic procedures].

Intracranial aneurysms, cervical carotid stenosis and acute cerebral ischemia constitute the three main and more frequent diseases in which the endovascular approach is considered a valuable alternative to the surgical or pharmacologic treatment. With the introduction of balloon assistance techniques, even intracranial large neck aneurysms can be currently suitable to endovascular treatment. Stent angioplasty is widely used in whole Europe in the treatment of cervical carotid artery stenosis. Mechanical endovascular embolectomy techniques are actually available to be used alone or in combination with pharmacologic thrombolysis in the treatment of acute cerebral ischemia. This article discuss on the new technical possibilities concerning the endovascular approach in these aforementioned diseases.

Aneurysm, Ruptured↗
PubMed2005

[Treatment of acute stroke].

The aim of this review is to discuss the different treatment strategies of acute stroke. The main studies performed with intravenous or intra-arterial thrombolysis are reported as well as the recent results concerning the use of IIb/IIIa platelet receptors antagonists. We will also discuss the potential effect of ultrasound on systemic thrombolysis. Finally are mentioned the most important measures to avoid medical and neurological complications which may occur during the acute phase of stroke.

Brain Ischemia↗
PubMed2005

Low-pressure reperfusion alters mitochondrial permeability transition.

We hypothesized that low-pressure reperfusion may limit myocardial necrosis and attenuate postischemic contractile dysfunction by inhibiting mitochondrial permeability transition pore (mPTP) opening. Male Wistar rat hearts (n = 36) were perfused according to the Langendorff technique, exposed to 40 min of ischemia, and assigned to one of the following groups: 1) reperfusion with normal pressure (NP = 100 cmH(2)O) or 2) reperfusion with low pressure (LP = 70 cmH(2)O). Creatine kinase release and tetraphenyltetrazolium chloride staining were used to evaluate infarct size. Modifications of cardiac function were assessed by changes in coronary flow, heart rate (HR), left ventricular developed pressure (LVDP), the first derivate of the pressure curve (dP/dt), and the rate-pressure product (RPP = LVDP x HR). Mitochondria were isolated from the reperfused myocardium, and the Ca(2+)-induced mPTP opening was measured using a potentiometric approach. Lipid peroxidation was assessed by measuring malondialdehyde production. Infarct size was significantly reduced in the LP group, averaging 17 +/- 3 vs. 33 +/- 3% of the left ventricular weight in NP hearts. At the end of reperfusion, functional recovery was significantly improved in LP hearts, with RPP averaging 10,392 +/- 876 vs. 3,969 +/- 534 mmHg/min in NP hearts (P < 0.001). The Ca(2+) load required to induce mPTP opening averaged 232 +/- 10 and 128 +/- 16 microM in LP and NP hearts, respectively (P < 0.001). Myocardial malondialdehyde was significantly lower in LP than in NP hearts (P < 0.05). These results suggest that the protection afforded by low-pressure reperfusion involves an inhibition of the opening of the mPTP, possibly via reduction of reactive oxygen species production.

Animals↗
PubMed2005

Protective effect of endotoxin preconditioning in pancreas: analysis with DNA chip arrays.

Recently we demonstrated a protective effect of endotoxin preconditioning 24 hours before pancreatic ischemia-reperfusion injury, which has also been described for other organs. The mechanisms underlying this phenomenon, such as differential gene expression, are poorly investigated. We chose to approach this question by investigating differential gene expression in the rat pancreas over the time course of endotoxin pretreatment. Male Wistar rats (5 groups, 5 animals per group) were pretreated with endotoxin intraperitoneally (1 mg/kg of body weight). After treatment at 30 minutes, and at 3 and 24 hours the pancreas was removed. Untreated animals and animals with injection of saline solution served as controls. After RNA isolation, RNA was pooled and hybridized to Affymetrix chips to measure the relative mRNA levels of 7000 genes and 1000 expression sequence tags. Three hours after administration of endotoxin there was an activation of proinflammatory transcription factors and other proinflammatory genes. After 24 hours there was a clear decrease of these proinflammatory genes, but a remaining and increasing upregulation of important antiapoptotic genes, antiproteases, and other probably protective genes. There was also a significant upregulation of complement factors. It was surprising that heat-shock proteins and other typical immediate early genes of the AP-1 complex were not upregulated. Our data show that 24 hours after endotoxin stress there is a regulation of a network of genes that represents a multifaceted preconditioning. As most important factors, inhibition of apoptosis and antiproteatic strategies are identified. Heat-shock proteins seem to play no important role in the mechanism of endotoxin preconditioning.

Animals↗