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Biomedical subjects

E Louis

Publications and source records attributed to E Louis.

At least 37 records · Page 2Linked to original sources

[Radiation-induced aneurysm of the cavernous internal carotid artery].

We report a case of intra-cranial aneurysm of the left cavernous internal carotid artery occurring 27 years after radiotherapy of the pterygopalatine fossa for Hodgkin disease. The development of the aneurysm within the irradiation field, the long latency after radiotherapy, the normality of carotid angiography before radiotherapy and the absence of other etiologies led to the diagnosis of radiation-induced aneurysm. The main characteristics of radiation-induced intra-cranial aneurysms are reviewed.

Carotid Artery, Internal↗

[Primary and secondary prevention of colorectal cancer].

Colorectal cancer is really a public health problem. The authors review the literature about the environmental factors leading to colorectal cancer. Chemoprevention of colorectal cancer is also discussed, particularly by aspirin and non steroidal anti-inflammatory drugs. Development of specific cyclooxygenase-2 inhibitors constitutes a promising research's field. Secondary prevention by coloscopy and polypectomy must lead to a lower rate of colorectal cancer disease and improvement of mortality.

Colonoscopy↗

[Bilateral amyotrophic neuralgia (Parsonage Turner syndrome) with HIV seroconversion].

We report a unusual case of neuralgic amyotrophy (NA) occurring during the seroconversion stage of an HIV infection. Combined with previously published cases, our observation suggests that NA associated with HIV could belong to the group of early multiplex mononeuritis. Neurologists should be aware of HIV infection when managing a patient with NA.

Adult↗

Effects of fluctuations on electrical properties of gap-junction connected cells in the turtle retina.

Electrical properties of gap-junction connected cells (input voltage and length constant) are shown to depend strongly on fluctuations in membrane and contact conductances. This opens new possibilities and incorporates a further difficulty to the analysis of electrophysiological data, since four, instead of two, parameters (the average values and the magnitude of fluctuations of the two conductances) have to be used in fitting the experimental data. The discussion is illustrated by investigating the effects of dopamine on signal spreading in horizontal cells of turtle retina, assuming a linear cell arrangement. It is shown that while a standard fitting with the average values of the two conductances leads to the conclusion that both are equally affected by dopamine, including fluctuations allows fitting the data by varying just the average contact conductance plus the magnitude of fluctuations.

Animals↗

Cytokine production from sputum cells after allergenic challenge in IgE-mediated asthma.

BACKGROUND: Th2 cytokine production from airway cells is thought to govern the eosinophilic airways inflammation in allergic asthma. Induced sputum has become a widely used technique to assess airways inflammation. METHODS: By applying the technique of induced sputum to collect airways cells, we have assessed the spontaneous production of a set of cytokines, including interleukin-4, 6, 10, interferon-gamma and tumour necrosis factor-alpha, 6 h after a bronchial allergenic challenge with Dermatophagoides pteronyssinus (Dpt) in 12 sensitized asthmatics and compared the results obtained after inhalation of saline as control. A group of eight healthy non-allergic subjects was enrolled to control for any non-specific effect of Dpt. Cytokines were measured by a dynamic immunoassay during a 24-h sputum cell culture. RESULTS: Allergen challenge in sensitized asthmatics caused an acute and a late bronchospasm together with a rise in sputum eosinophil counts. Afterwards allergen sputum cells from allergic asthmatics displayed a rise in their production of IL-4 (P < 0.01), IL-6 (P < 0.05) and IL-10 (P < 0.05) when compared to saline. By this time sputum generation of IL-4 in atopic asthmatics was greater than in healthy subjects (P < 0.001). Furthermore, in allergic asthmatics there was a strong correlation between the rise in interleukin-4 production from sputum cells and the rise in sputum eosinophils (r = 0.87, P < 0.001). CONCLUSIONS: Sputum cell culture is a useful model to assess cytokine production in allergic asthmatics who show a marked up-regulation of Th2 cytokines following acute allergen exposure. The rise in sputum eosinophil count following allergen challenge strongly correlates with the rise in IL-4 generation from sputum cells.

Adult↗

Strictureplasty in Crohn's disease: short- and long-term follow-up.

Strictureplasty for obstructive Crohn's disease is still controversial because lesions are left in place and the suture is performed on a diseased bowel. Many surgeons prefer to perform bowel resection, hoping for fewer complications and a lower recurrence rate. In this paper, the authors reports their strictureplasty experience. They performed a systematic retrospective review of the patients suffering from Crohn's disease who underwent strictureplasties during a 10-year period in the abdominal surgery department of the University Hospital of Liège Sart Tilman, and studied the short- and long-term clinical results of 68 strictureplasties performed in 18 patients. Median follow-up was 63 months (range 12 to 144). Mortality was 0% and septic morbidity was 11% (one wound abscess and one leakage). Among the 16 patients available for the latest follow-up, symptomatic stenotic recurrence had to be medically treated in hospital for 4 patients (25%) with a recurrence delay range of 19 to 49 months. Stenosis recurrence needed re-intervention in one patient 48 months after surgery: stenosis occurred at a distance from the corrected site. These results confirmed that strictureplasty is a safe and efficient procedure in selected patients undergoing surgery for obstructive Crohn's disease.

Adult↗

Serological markers for prediction of response to anti-tumor necrosis factor treatment in Crohn's disease.

OBJECTIVES: The use of monoclonal anti-tumor necrosis factor (TNF) antibodies (infliximab, Remicade) is a new therapeutic approach for severe refractory luminal or fistulizing, Crohn's disease (CD). However, up to 30% of patients do not respond to this treatment. So far, no parameters predictive of response to anti-TNF have been identified. Our aim was to determine whether serological markers ASCA (anti-Saccharomyces cerevisiae antibodies) or pANCA (perinuclear antineutrophil cytoplasmic antibodies) could identify Crohn's patients likely to benefit from anti-TNF therapy. METHODS: Serum samples of 279 CD patients were analyzed for ASCA and pANCA before anti-TNF therapy. A blinded physician determined clinical response at week 4 (refractory luminal CD) or week 10 (fistulizing CD) after the first infusion of infliximab (5 mg/kg). RESULTS: Overall, there was no relationship between ASCA or pANCA and response to therapy. However, lower response rates were observed for patients with refractory intestinal disease carrying the pANCA+/ASCA- combination, although this lacked significance (p = 0.067). CONCLUSIONS: In this cohort of infliximab-treated patients, neither ASCA nor pANCA could predict response to treatment. However, the combination pANCA+/ASCA- might warrant further investigation for its value in predicting nonresponse in patients with refractory luminal disease.

Adolescent↗

[Pharma-clinics medication of the month. Rabeprazole (Pariet)].

Proton pomp inhibitors (PPI) have revolutionized the treatment of gastro-oesophageal reflux disease and gastro-duodenal ulcers. Rabeprazole (Pariet) is the last PPI arrived on the Belgian market. Controlled studies have shown an efficacy similar to emeprazole in the treatment of oeso-gastro-duodenal acid diseases. Rabeprazole has a favourable profile with rapid action and good safety.

2-Pyridinylmethylsulfinylbenzimidazoles↗

[Frontal sinus osteomas: neuro-ophthalmological complications].

Osteomas are the most frequent benign tumors of the paranasal sinuses. They often grow in the frontal sinus near the nasofrontal duct. They remain frequently asymptomatic and they tend to be an incidental finding on radiographic studies. Rarely, they extend out of the sinus limits. Two cases with neuro-ophthalmological complications are reported and discussed. A 19-year-old female presented with a progressive left visual impairment and orbital bone deformity. A CT-scan revealed a large calcified mass in both frontal sinuses, with left intraorbital and frontobasal extension. A 21-year-old man suffered from acute frontoethmoidal sinusitis. Radiological exams revealed a right frontal sinus osteoma with bilateral nasofrontal ducts obstruction. The frontal sinus cavities were filled with a large mucocele with intracranial extension. Both patients were successfully treated using frontobasal craniotomy with complete osteoma and mucocele removal and cranio facial bone reconstruction. Neuro-ophthalmological or intrasinusal complications of osteomas lead to radical treatment. CT-scan and MRI analysis for surgical purpose and strategy are emphased.

Adult↗

A positive response to infliximab in Crohn disease: association with a higher systemic inflammation before treatment but not with -308 TNF gene polymorphism.

BACKGROUND: Two-thirds to three-fourths of patients with either refractory luminal or fistulizing Crohn disease respond to infliximab treatment. The ability or inability to respond seems to persist over time. Biological characteristics and/or genetic background can influence the response to treatment. The aim was to assess the value of C-reactive protein and TNF-alpha serum levels before treatment as well as the TNF -308 gene polymorphism in the prediction of response to infliximab treatment in Crohn disease. METHODS: Two-hundred-and-twenty-six Crohn disease patients treated in the setting of an expanded access programme to infliximab in Belgium were studied. There were 136 refractory luminal diseases and 90 refractory fistulizing diseases. Luminal diseases were treated with one single infusion; fistulizing diseases with three infusions at weeks 0, 2 and 6. A clinical response to treatment was defined as either a Crohn disease activity index <150 (complete) or a drop of 70 points (partial) at week 4, for luminal disease, and as either complete fistula healing (complete) or a decrease of at least 50% of the number of draining fistulas on two consecutive visits between weeks 0 and 18, for fistulizing disease. CRP and serum TNF-alpha levels were measured at week 0 before treatment and were compared between responders and non-responders. Patients were genotyped for the -308 TNF gene polymorphism, and allelic as well as genotype frequencies were compared between responders and non-responders. RESULTS: There were 73.2% responders (46.4% complete and 26.8% partial) and 26.8% non-responders. Response rates were similar in luminal and fistulizing diseases. CRP level before treatment was significantly higher in responders than in non-responders (16.8 mg/l (5-160) versus 9.6 mg/l (5-143); P = 0.02). Furthermore, response rate was significantly higher in patients with elevated CRP (>5 mg/l) than in patients with a normal CRP value (<5 mg/l) before treatment (76% versus 46%; P=0.004; OR: 0.26 (0.11-0.63)). Allelic and genotype frequencies for -308 TNF gene polymorphism were not significantly different between responders and non-responders--with the exception of a slightly higher TNF2 frequency in non-responders in luminal disease (22.1 % versus 11.6%; P = 0.04). However, this was not associated with a significant difference in genotype frequencies. CONCLUSION: A positive clinical response to infliximab was associated with a higher CRP level before treatment in our population of Crohn disease patients, but there was no relevant association with -308 TNF gene polymorphism. We therefore suggest that CRP level may help to identify better candidates for infliximab treatment.

Adolescent↗

[Pathological implications in the neuroendocrine gastrointestinal system].

The neuroendocrine system is made of endocrine cells disseminated in various organs. In this article, we will focus on the implication of the neuroendocrine system in digestive pathology. First of all, we will review the neuroendocrine tumors in every location and then describe their classification, epidemiology, symptomatology, diagnosis and treatment. Finally, we will consider the implications of the neuroendocrine system in the inflammatory and functional pathology of the digestive tract.

Carcinoid Tumor↗

[Barrett's esophagus: overview].

Barrett's oesophagus (BE) is a segment of columnar lined epithelium in the distal oesophagus, above the gastrooesophageal junction. So it is important to localize this junction endoscopically; the proximal margin of the gastric folds is the anatomic landmark. Another important feature of BE is the specialized intestinal metaplasia. In the aetiology of this condition, acid reflux is a primary event but there is evidence that other factors are causal. As BE is a well known premalignant condition, detection of dysplastic epithelium and its severity is the crucial element. Practical guidelines are presented for endoscopic surveillance program. The purpose is the early detection of high grade dysplasia and carcinoma to advise oesophagectomy or endoscopic ablation therapy for patients unfit to undergo surgery.

Algorithms↗

[Pharma clinics medication of the month. Esomeprazole].

Esomeprazole is the last PPI registered on the Belgian market. It is the stable s-isomer of omeprazole. It has a better pharmacokinetic profile than omeprazole (racemate), allowing also better clinical performances. Esomeprazole is the first PPI shown superior to omeprazole in acute and chronic treatment of gastro-esophageal reflux disease. Controlled trials with this drug have also allowed to define new cost-effective strategies, such as on demand treatment for endoscopy-negative gastro-esophageal reflux and one week treatment of Helicobacter pylori positive duodenal ulcer.

Cost Control↗

Detecting determinism in high-dimensional chaotic systems.

A method based upon the statistical evaluation of the differentiability of the measure along the trajectory is used to identify determinism in high-dimensional systems. The results show that the method is suitable for discriminating stochastic from deterministic systems even if the dimension of the latter is as high as 13. The method is shown to succeed in identifying determinism in electroencephalogram signals simulated by means of a high-dimensional system.

Journal Article↗

Transpedicular screw placement: image-guided versus lateral-view fluoroscopy: in vitro simulation.

STUDY DESIGN: In vitro evaluation of monitoring screw placement using an image-guided system compared with the routine use of an image intensifier. OBJECTIVES: To compare a new computer-guided method of monitoring pedicle screw placement with a well-known method of monitoring using an image intensifier, using measurements of screw placement time and accuracy. SUMMARY OF BACKGROUND DATA: Pedicle screw placement relies on the identification of anatomic landmarks for the point of entry of the pedicle. The direction and depth of screw penetration are guided by an intraoperative lateral-view image intensifier. The use of frameless stereotaxy for computer-aided pedicle screw placement may increase the accuracy and safety of the screw insertion. To the authors' knowledge, there are no published data comparing these systems on the basis of operative time and screw placement accuracy. METHOD: Eight human cadaveric sections of five vertebrae each were used for an in vitro simulation of pedicle screw placement. Four spine surgeons were chosen to simulate the transpedicular screw placement. Each surgeon placed one screw into each pedicle of two spine sections (10 vertebrae, 20 screws). The surgeon was assisted by the lateral-view image intensifier on one spine section and by the navigational system on the second one. The four surgeons placed 80 pedicle screws. Forty screw placements were monitored by fluoroscopy and 40 by the image-guided navigational system. The time spent to place one screw was recorded, as well as the remarks by each surgeons on each method. Spines were rescanned, and the positions of the screws were compared between the group on which the image intensifier has been used and the group on which the navigational system had been used. RESULTS: In the image-guided technique group, one thoracic screw disrupted the lateral cortex of the pedicle, the average distance to the anterior wall of the body was 5 mm, and the average time for the insertion of one screw was 13.5 minutes. In the other group, two screws disrupted the inner cortex of a thoracic pedicle, the average distance to the anterior wall was 10.7 mm, and the average time for the insertion of one screw was 4 minutes. CONCLUSIONS: In vitro computer-aided pedicle screw insertion is more accurate than lateral-view fluoroscopy in the thoracic spine. The main disadvantage is the time consumption compared with that required by lateral-view fluoroscopy. The total time of the surgical operation should be decreased with the future development of these techniques.

Bone Screws↗

Foramen magnum syndrome secondary to calcium pyrophosphate crystal deposition in the transverse ligament of the atlas.

STUDY DESIGN: This report illustrates two rare cases of foramen magnum syndrome caused by a retro-odontoid mass in which calcium pyrophosphate dihydrate crystals were found. OBJECTIVES: To analyze the preoperative studies and the diagnostic criteria and to discuss the surgical treatment. The present cases will be compared with previous ones described in the literature. SUMMARY OF BACKGROUND DATA: Deposition of calcium pyrophosphate dihydrate crystals occurs into the fibrous and hyaline cartilage of the joints and intervertebral discs of the spine. Half of the patients known to have a chondrocalcinosis had asymptomatic calcification in the odontoid region. Ten patients were published in the literature as having a spinal cord syndrome secondary to calcium pyrophosphate dihydrate deposition in the odontoid region. METHODS: In both cases the preoperative studies were analyzed, and the retro-odontoid mass was resected and histologically examined. Both had an anterior transoral approach and have been followed for 1 year. RESULTS: According to the preoperative radiographs the diagnosis was suspected and confirmed histologically. Transoral approach was done with no need in either case for a posterior stabilization. CONCLUSIONS: Compression of the spinal cord by calcium pyrophosphate dihydrate deposition may occur. The preoperative diagnosis may be highly suspected after radiographic study and histologically confirmed. Transoral resection is the treatment of choice. Posterior stabilization should be considered only in cases of craniovertebral instability.

Aged↗