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Biomedical subjects

B Bertrand

Publications and source records attributed to B Bertrand.

At least 19 recordsLinked to original sources
PubMed2001

Trueness-to-type and agronomic characteristics of Coffea arabica trees micropropagated by the embryogenic cell suspension technique.

Trueness-to-type and agronomic characteristics of trees of four coffee (Coffea arabica L.) F(1) hybrid clones derived from embryogenic cell suspensions were compared with those of trees produced from in vitro microcuttings. Three types of variants were observed among the 644 trees derived from embryogenic suspensions. Total frequency of the variants was 2.1% for trees originating from embryogenic cell suspensions, whereas no variant was found among the trees produced from microcuttings. The variant known as "thick leaf" had thick leaves, many abnormally starry flowers and low yields of large fruit. The "dwarf" variant was characterized by slow growth and small fruit. The "dwarf peaberry" variant had abnormal seeds in a single cavity, in addition to the "thick leaf" and "dwarf" characteristics. Compared with normal trees, the variants differed in leaf density and number of chloroplasts per guard cell. The variants aside, there were no differences in the main agronomic characteristics between trees produced from embryogenic suspensions and those produced from microcuttings. For all four clones, the trees had vegetative characteristics, productivity, fertility, and bean biochemical, mineral and organoleptic characteristics that were identical to those of the controls. We conclude that it is possible to generate coffee trees commercially with normal agronomic performance from embryogenic suspensions, because the frequency with which somaclonal variants occur is limited.

Agriculture↗
PubMed2000

First human transvenous coronary angiography at the European Synchrotron Radiation Facility.

The first operation of the European Synchrotron Radiation Facility (ESRF) medical beamline is reported in this paper. The goal of the angiography project is to develop a reduced risk imaging technique, which can be used to follow up patients after coronary intervention. After the intravenous injection of a contrast agent (iodine) two images are produced with monochromatic beams, bracketing the iodine K-edge. The logarithmic subtraction of the two measurements results in an iodine enhanced image, which can be precisely quantified. A research protocol has been designed to evaluate the performances of this method in comparison with the conventional technique. Patients included in the protocol have previously undergone angioplasty. If a re-stenosis is suspected, the patient is imaged both at the ESRF and at the hospital with the conventional technique, within the next few days. This paper reports the results obtained with the first patients. To date, eight patients have been imaged and excellent image quality was obtained.

Angioplasty, Balloon, Coronary↗
PubMed2000

Sinonasal lymphomas. Case report.

In the field of Otorhinolaryngology sinonasal lymphomas are relatively uncommon and represent less than 1% of all head and neck malignancies. Nowadays, they are regarded as consisting of two distinct subgroups, characterised by phenotype, location, prognosis and treatment. Lymphomas of the B-Cell phenotype are the most frequent type found in the paranasal sinuses. They are less aggressive and carry a relatively better prognosis. T/NK-Cell lymphomas are mostly found in the nasal cavity. They are more aggressive and carry a relatively worse prognosis. We present a case of a 65-year-old patient, who complained with unilateral right-sided nasal obstruction associated with a sensation of right aural fullness. CT scan demonstrated opacity of the posterior ethmoid and sphenoid sinuses on the right side, with evidence of erosion of the anterior wall of the sphenoid. Nasal endoscopy revealed a smooth purple mass, arising from the right superior meatus, which bled on contact, and which was subsequently shown to be, on histological assessment, a malignant high grade lymphoma, non-Hodgkin's B-cell phenotype. Following a discussion of the case we will present a review of these tumours, which have a poor overall prognosis, focusing on epidemiology, sites of origin, symptoms, investigation and management.

Aged↗
PubMed2000

Congenital nasal pyriform aperture stenosis in newborn: report on three cases.

Congenital nasal pyriform aperture stenosis (CNPAS) is recognized as a cause of nasal airway obstruction in the newborn. The nasal pyriform aperture is narrowed by a bony overgrowth of the nasal process of the maxilla. The CNPAS may occur as an isolated congenital defect or in combination with other abnormalities. Three cases of CNPAS are reported with special attention to the clinical presentation and to the management recommendation prior to surgery. Surgical repair was performed for all these three highly symptomatic patients using a sublabial approach for drilling the nasal process in order to obtain a wider nasal vestibular patency. All of them were equipped with bilateral nasal stenting.

Female↗
PubMed2000

Endoscopic endonasal surgery for paranasal sinus mucoceles.

Paranasal sinus mucoceles are benign, space-occupying, cystic lesions that require a surgical treatment. An endoscopic endonasal marsupialisation is nowadays the surgical approach of choice in most of the cases. The aim of the present study is to validate this option and to determine the clinical characteristics of paranasal sinus mucoceles. A retrospective study based on the clinical experience of several ENT surgeons was performed using a standardised questionnaire. The respondents participate to a report on endoscopic endonasal surgery for non-inflammatory disease in Belgium. One hundred and fourty patients presenting 178 mucoceles were included in this study. Primitive mucoceles were reported in 35% of the patients, posttraumatic mucoceles in 2.1% and postoperative mucoceles in 62.9%. The time interval between first rhinologic procedure and the mucocele diagnosis was respectively 24.4 months after FESS and 108.3 months after an external procedure. Paranasal sinus mucoceles predominantly occur in the fronto-ethmoidal region (64%), followed by the maxillary sinus (18.6%), the sphenoid sinus (8.4%) and the posterior ethmoid sinus (6.7%). Uncommon locations were also reported in 2.3% (Inferior turbinate, middle turbinate, pterygomaxillary space). Endoscopic endonasal marsupialisation (combined with an external procedure for 8 patients) was successful in 97.9% of the patients. Only 3 patients showed recurrence. Endoscopic endonasal marsupialisation of paranasal sinus mucoceles is a reliable therapeutic option with favorable results and is supported by the questioned ENT surgeons in Belgium.

Adolescent↗
PubMed2000

Surgery of inverted papillomas under endoscopic control.

Six centers cooperated in a retrospective study on endoscopic surgical resection of Papillomas of the nose and paranasal sinuses in order to assess both the efficiency and the safety of this kind of surgical approach. From 1991 till march 2000, 87 cases of Papillomas resections under--at least partially--endoscopic control were gathered, among which 85 were Inverted Papillomas (IP), 2 were Exophytic Papilloma (EP) and one was IP coexisting with Collumnar Cell Papilloma (CCP). Malignant transformation was found out in 3 cases of IP. Regarding the 85 patients with IP demographics are as follows: 61 males, 24 females, with a mean age of 58.4 years (STDV: 13.96) in a range from 27 to 92 years. The mean follow-up was of 41.9 months with range of 1-120 months. Fifteen recurrences occurred that were treated by revision surgery either under endoscopic control or by limited external approach. The mean time for recurrences to occur was 8.07 months with range of 1-24 months. The three patients with malignant transformation underwent postoperative radiation therapy. All of the patients are free of recurrence, however for some of them the follow-up is too short to definitely assess their free of disease status. The role of modern diagnostic tools in medical imaging--CAT and MRI--in order to assess clearly the limits of the tumors and to enhance the efficiency and the safety in the choice of a surgical approach is pointed out. The stress is put on the need for radical excision under endoscopic control which can be combined with the Caldwell-Luc transantral approach or with frontal trepanation for the cure of tumors impossible to be reached under endoscopic control only. Irrespective of the tumor extent and of the approaches that was used for excision a close endoscopic follow-up still remain mandatory, by trained surgeons, in the long term management of IP. Biopsies, CAT and/or MRI must be performed in any case with recurrence suspicion.

Adult↗
PubMed2000

Transcanalicular diode laser assisted dacryocystorhinostomy.

AIM OF THE STUDY: To assess the validity of transcanalicular diode laser assisted dacryocystorhinostomy (TLADCR) in the treatment of distal obstruction of the lachrymal pathways. MATERIAL AND METHOD: Between June 1999 and February 2000, 29 TLADCR were performed in the ENT department on 26 patients. Surgical indications included chronic dacryocystitis in 19 cases and dacryostenosis in 10 cases. In all cases but one, the surgery was carried out under a standard general anesthetic. The diode laser was used with a power setting of 10 watts. RESULTS: Seventeen out of 29 TLADCR were regarded as having successful outcomes. 2 out of 29 TLADCR had a little persisting tearing regarded as non debilitating and much less than which was present preoperatively. In 10 out of 29 TLADCR, the procedure was deemed a failure. These failures included 4 out of the 10 primary dacryostenosis and 6 out of the 19 chronic dacryocystitis. Two patients refused further treatment. In the other 8, surgical revision was undertaken via the traditional endonasal approach. In 7 of these cases, the lachrymal system was full of purulent secretions. COMPLICATIONS: Two patients developed a partial stenosis of one canaliculus that was diagnosed during the surgical revision. Another patient had a small fistula between the canalicular system and the skin of the corner of the eye that disappeared after the revision surgery. In one other case, the superior canaliculus was cauterised by the denudated portion of a resculpted laser fibre. Two bicanalicular nasal stent required reinsertion. Three patients developed a granuloma around the stent. Four patients developed an episode of infection whilst the stent was still in situ. CONCLUSION: Transcanalicular diode laser assisted dacryocystorhinostomy (TLADCR) performed with a 600-micron contact fibre is a relatively simple, elegant and effective procedure when used in conjunction with nasal endoscopy, to treat distal obstruction of the lachrymal pathways. But, the cost, the high prevalence of minor complications and the currently higher reported failure rate would favour external or endonasal approaches over this approach.

Adolescent↗
PubMed2000

Transnasal endoscopic orbital decompression and Graves' ophtalmopathy.

AIM OF THE STUDY: To assess the validity and the limits of endoscopic endonasal orbital decompression for Graves' ophtalmopathy resistant to the medical theapy. MATERIAL AND PATIENTS: Between September 1994 and May 1998, 16 patients with Graves' ophtalmopathy resistant to the medical treatment underwent an orbital decompression transnasally. 27 orbits were decompressed. The surgery was bilateral in 11 patients. In the 5 remaining cases, the surgery was unilateral. It was carried out on the left side in 2 cases and on the right side in 3 cases. RESULTS: Preoperatively, the average visual acuity was 8/10. Postoperatively, the visual acuity was 9.5/10. The average preoperative exophtalmometry measurement was 25.04 mm and the average postoperative measurement was 21.83 mm. The average retrodisplacement was 3.17 mm (range: 2-8). Preoperatively, 3 patients had mild diplopia whereas 5 others had moderate to severe extraocular muscle dysfunction. Postoperatively, 6 patients had mild diplopia whereas 10 patients required squint surgery for moderate to severe extraocular muscle dysfunction. CONCLUSION: Endoscopic orbital decompression improve all the symptoms of Graves' ophtalmopathy but one: the extraocular muscle dysfunction. Its cardinal indication is the treatment of compressive optic neuropathy whereas this surgical approach provides an excellent control of the medial wall of the orbit and the orbital apex. But the average reduction of proptosis of 3.17 mm is not high enough to propose this approach alone for the treatment of disfiguring proptosis. In such cases, a 2 or 3 wall orbital decompression should be performed to get marked cosmetic and functional improvement. In all cases, the patient should be informed about the risk of postoperative diplopia.

Adult↗
PubMed2000

Research at the European Synchrotron Radiation Facility medical beamline.

The application of synchrotron radiation in medical research has become a mature field of research at synchrotron facilities worldwide. In the relatively short time that synchrotrons have been available to the scientific community, their characteristic beams of UV and X-ray radiation have been applied to virtually all areas of medical science which use ionizing radiation. The ability to tune intense monochromatic beams over wide energy ranges differentiates these sources from standard clinical and research tools. At the European Synchrotron Radiation Facility (Grenoble, France), a major research facility is operational on an advanced wiggler radiation beamport, ID17. The beamport is designed to carry out a broad range of research ranging from cell radiation biology to in vivo human studies. Medical imaging programs at ID17 include transvenous coronary angiography, computed tomography, mammography and bronchography. In addition, a major research program on microbeam radiation therapy is progressing. This paper will present a very brief overview of the beamline and the imaging and therapy programs.

Animals↗
PubMed2000

In vivo K-edge imaging with synchrotron radiation.

We present in this paper two imaging techniques using contrast agents assessed with in vivo experiments. Both methods are based on the same physical principle, and were implemented at the European Synchrotron Radiation Facility medical beamline. The first one is intravenous coronary angiography using synchrotron radiation X-rays. This imaging technique has been planned for human studies in the near future. We describe the first experiments that were carried out with pigs at the ESRF. The second imaging mode is computed tomography using synchrotron radiation on rats bearing brain tumors. Owing to synchrotron radiation physical properties, these new imaging methods provide additional information compared to conventional techniques. After infusion of the contrast agent, it is possible to derive from the images the concentration of the contrast agent in the tumor area for the computed tomography and in any visible vessel for the angiography method.

Animals↗
PubMed2000

Secondary ciliary dyskinesia in upper respiratory tract.

The system of mucociliary clearance has the important task to remove from the airways inhaled substances and locally formed secretions. Inborn disorders of the mucociliary transport are due to ciliary dysfunction (Primary Ciliary Dyskinesia) (PCD) or of increased viscosity of the bronchial secretions (Cystic Fibrosis). To differentiate PCD from the ultrastructural abnormalities found during or after injuries such as respiratory infections, the name of Secondary--or acquired--Ciliary Dyskinesia (SCD) was created. In controls, less than 4% of the cilia may show ultrastructural abnormalities. The most frequent of these are the compound cilia and the peripheral microtubular abnormalities. Compound cilia often appear after infection and therefore are thought to arise secondarily. Secondary ultrastructural abnormalities of cilia include also blebs of the axoneme membrane, ciliary disorientation, and absence of axoneme membrane. No increase in ultrastructural ciliary abnormalities has been found in a variety of respiratory disorders: smoking, asthma and allergic rhinitis, chronic rhinitis and sinusitis, chronic bronchitis, cystic fibrosis, and lung carcinoma. But severe modifications of the respiratory epithelium can be seen. Important for the secondary ciliary disorders is their local and reversible character. To distinct from ultrastructural images between primary and secondary ciliary dyskinesia is often uneasy because some of the findings in secondary ciliary dyskinesia obviously mimic those dedicated to primary ciliary dyskinesia.

Bacterial Infections↗
PubMed1998

Impact of intravascular ultrasound guidance in stent deployment on 6-month restenosis rate: a multicenter, randomized study comparing two strategies--with and without intravascular ultrasound guidance. RESIST Study Group. REStenosis after Ivus guided STenting.

OBJECTIVES: We aimed to investigate the impact of intravascular ultrasound (IVUS)-guided stent implantation on the 6-month restenosis rate, which has not yet been fully established in randomized trials. BACKGROUND: The 6-month angiographic restenosis rate was compared in patients with symptomatic ischemic heart disease who were randomly allocated to angioplasty and stent deployment, with versus without IVUS guidance. METHODS: After successful stent implantation, patients were randomized into two groups: Group A had no further dilation, and Group B had additional balloon dilation until achievement of IVUS criterion for stent expansion. The study group consisted of 164 patients, assuming a 50% reduction of the restenosis rate in Group B (15% vs. 30%) (alpha = 10%, beta = 20%). RESULTS: We enrolled 155 patients. Overdilation was carried out in 31 (39%) of 79 Group B patients, with the IVUS criterion being achieved in 63 (80%) of 79. No significant difference was observed in the minimal luminal diameter (MLD), but the stent lumen cross-sectional area (CSA) was significantly larger in Group B (mean +/- SD) (7.16 +/- 2.48 vs. 7.95 +/- 2.21 mm2, p = 0.04). At 6 months, there was no significant difference in the restenosis rate, (28.8% [21 of 73] in Group A vs. 22.5% [16 of 71] in Group B, p = 0.25), but according to the observed difference in the restenosis rate, the power of the study was only 40%. The difference in MLD was also nonsignificant (1.60 +/- 0.65 mm in Group A vs. 1.70 +/- 0.64 mm in Group B, p = 0.20), whereas the lumen CSA was 20% larger in the IVUS-guided group (4.47 +/- 2.59 vs. 5.36 +/- 2.81 mm2, p = 0.03). Lumen CSA was the only predictor of restenosis by multivariate logistic regression analysis. CONCLUSIONS: A nonsignificant 6.3% absolute reduction in the restenosis rate and a nonsignificant difference in MLD were observed in this study. Nonetheless, we still cannot rule out a beneficial effect of IVUS guidance, although this may have gone undetected owing to a lack of statistical power. A significant increase was observed in immediate and 6-month lumen size, as detected by IVUS, indicating that ultrasound guidance in stent deployment may be beneficial.

Angioplasty, Balloon, Coronary↗
PubMed1998

[Maxillary actinomycosis and maxillary candidiasis in the immunocompetent patient].

Two distinct cases of maxillary actinomycosis and maxillary candidosis in immunocompetent hosts are reported; These infections are rare and similar to mycotic extramucosal non allergic sinusitis. Microbiology and microscopic examination are mandatory to prompt and successful management. Endoscopic endonasal surgery by middle meatotomy seems to be an adequate treatment for these particular entities.

Actinomycetales Infections↗
PubMed1998

Nocturnal oxymetry in patients with total nasal packing.

Nocturnal oxymetry was recorded in ten otherwise healthy patients undergoing different types of nasal surgery with total nasal packing. Postoperative nocturnal oxymetry was worse than preoperative one in seven patients and judged as abnormal in four. These results indicate that in otherwise healthy subjects, nasal surgery and total nasal packing induce immediate significant changes in nocturnal breathing.

Adult↗
PubMed1997

Aortic plaque morphology and vascular events: a follow-up study in patients with ischemic stroke. FAPS Investigators. French Study of Aortic Plaques in Stroke.

BACKGROUND: Atherosclerotic disease of the aortic arch has been found to be associated with the risk of ischemic stroke. We have shown that atherosclerotic plaques > or = 4 mm in thickness in the ascending aorta and proximal arch detected by transesophageal echocardiography are a risk factor for ischemic stroke. The purpose of this study was to evaluate the impact, if any, of plaque morphology (ulceration, hypoechoic plaques or calcification) on the risk of subsequent vascular events. METHODS AND RESULTS: We followed for a period of 2 to 4 years, a cohort of 334 patients 60 years or older who were consecutively admitted with brain infarction and who had transesophageal echocardiography. The risk of vascular events in patients with plaques in the aortic arch according to the presence of surface ulceration, calcifications, and sessile or mobile thrombus was estimated during a total of 788 person-years of follow-up. Hypoechoic plaques, calcifications, and ulceration were more frequently found in patients with plaques > or = 4 mm as compared with those with plaques < 4 mm. The presence of ulceration did not increase the relative risk of vascular events in patients with plaque > or = 4 mm (the relative risk was 4.3 [P<.001] in those with ulceration and 5.7 [P<.001]) in those without ulceration. The lack of calcification did increase the risk of vascular events in patients with plaque > or = 4 mm. The highest relative risk of events was found among the patients with noncalcified plaques (relative risk, 10.3; 95% confidence interval, 4.2 to 25.2; P<.001). The risk of events was systematically higher in patients without calcifications than in patients with calcifications regardless of what other morphological features were considered. CONCLUSIONS: In patients with brain infarction, the risk associated with aortic plaque thickness (> or = 4 mm) is markedly increased by the absence of plaque calcifications. These findings are important for the design of therapeutic trials in such patients.

Aged↗
PubMed1997

Effect of nadroparin, a low-molecular-weight heparin, on clinical and angiographic restenosis after coronary balloon angioplasty: the FACT study. Fraxiparine Angioplastie Coronaire Transluminale.

BACKGROUND: Experimental studies suggest that the antiproliferative effect of heparin after arterial injury is maximized by pretreatment. No previous studies of restenosis have used a pretreatment strategy. We designed this study to determine whether treatment with nadroparin, a low-molecular-weight heparin, started 3 days before the procedure and continued for 3 months, affected angiographic restenosis or clinical outcome after coronary angioplasty. METHODS AND RESULTS: In a prospective multicenter, double-blind, randomized trial, elective coronary angioplasty was performed on 354 patients who were treated with daily subcutaneous nadroparin (0.6 mL of 10,250 anti-Xa IU/mL) or placebo injections started 3 days before angioplasty and continued for 3 months. Angiography was performed just before and immediately after angioplasty and at follow-up. The primary study end point was angiographic restenosis, assessed by quantitative coronary angiography 3 months after balloon angioplasty. Clinical follow-up was continued up to 6 months. Clinical and procedural variables and the occurrence of periprocedural complications did not differ between groups. At angiographic follow-up, the mean minimal lumen diameter and the mean residual stenosis in the nadroparin group (1.37+/-0.66 mm, 51.9+/-21.0%) did not differ from the corresponding values in the control group (1.48+/-0.59 mm, 48.8+/-18.9%). Combined major cardiac-related clinical events (death, myocardial infarction, target lesion revascularization) did not differ between groups (30.3% versus 29.6%). CONCLUSIONS: Pretreatment with the low-molecular-weight heparin nadroparin continued for 3 months after balloon angioplasty had no beneficial effect on angiographic restenosis or on adverse clinical outcomes.

Adolescent↗