Biomedical subjects

C Lemoine

Publications and source records attributed to C Lemoine.

At least 19 recordsLinked to original sources

PubMed2006

Development and commissioning of decision support tools for sewerage management.

Managing sewerage systems is a highly complex task due to the dynamic nature of the facilities. Their performance strongly depends on the know-how applied by the operators. In order to define optimal operational settings, two decision support tools based on mathematical models have been developed. Moreover, easy-to-use interfaces have been created as well, aiding operators who presumably do not have the necessary skills to use modelling software. The two developed programs simulate the behaviour of both wastewater treatment plants (WWTP) and sewer network systems, respectively. They have essentially the same structure, including raw data management and statistical analysis, a simulation layer using the application programming interface of the applied software and a layer responsible for the representation of the obtained results. Four user modes are provided in the two software including the simulation of historical data using the applied and novel operational settings, as well as modes concerning prediction of possible operation periods and updates. Concerning the WWTP software, it was successfully installed in Nantes (France) in June 2004. Moreover, the one managing sewer networks has been deployed in Saint-Malo (France) in January 2005. This paper presents the structure of the developed software and the first results obtained during the commissioning phase.

Computer Simulation↗

PubMed2006

Aeration control for simultaneous nitrification-denitrification in a biological aerated filter using internal model approach.

Experience has shown that simultaneous nitrification/denitrification in a biological aerated filter is possible. However these systems react very sensitively to the aeration control strategies applied. Poorly adapted control strategies induce a strong decrease in treatment efficiency. A new control strategy for simultaneous N/DN is developed. The strategy proposed makes use of ammonia measurements and the inlet and outlet: a Feedback/Feedforward block. Passing by a calculation of the load to be eliminated, an estimation of the air flow velocity to be applied is carried out dynamically. A retroactive loop corrects this prediction in order to reach exactly the desired set point. This control approach has been implemented and tested at pilot plant scale for a period of 18 months. The pilot plant consists of two coupled BAF cells, reflecting closely industrial scale situations. Comparative studies reveal clearly the improved performance of the developed FF/FB control strategy compared to classical controllers. The benefits include 5% increase in nitrogen removal performance and a reduction of 15 to 20% in air requirement, offering a rapid return of investment costs.

Algorithms↗

PubMed2005

Age related differences in the strategies used by middle aged adults to solve a block design task.

In the present study, it was proposed to investigate the effects of aging on the strategies used to solve a block design task and to establish whether these strategies may be associated with differential patterns of ability. Two groups of subjects, 30 young adults (aged 20-35 years) and 30 middle-aged adults (aged 45-60 years) were set a computer version of the Kohs task and a battery of tests. An age-related decrease in fluid intelligence (Gf) and visual-spatial ability (Gv) was observed, along with the fact that most of the older subjects used a global strategy rather than a synthetic one. On the other hand, while continuing to use strategies of the analytic type, the older subjects looked more frequently at the model and scored high on crystallized intelligence (Gc). These findings are discussed from two different points of view: the theory of hierarchical stimuli and the hypothesis that metacognitive ability, which is thought to rely on Gc, may increase with age, and thus compensate for the loss of Gf and Gv.

Adult↗

PubMed2004

Wide QRS complex tachycardia. Rapid method of prognostic evaluation.

UNLABELLED: A wide QRS complex tachycardia suggests a ventricular tachycardia (VT); but supraventricular tachycardia (SVT) is also possible. Some authors reported on the electrocardiographic signs for the differential diagnosis of VT and SVT with aberrancy. Frequently these signs are debatable and the diagnosis is uncertain. The purpose of the study was to evaluate the interest of a non-invasive study by transesophageal route for the evaluation of the nature of a wide QRS complex tachycardia in which a reliable ECG algorithm does not permit to distinguish VT from SVT with aberrancy. METHODS: Esophageal electrophysiologic study (EPS) was performed in 53 patients, aged from 16 to 85 years without bundle branch block (BBB) in sinus rhythm, but with wide-QRS tachycardia. The protocol consisted of atrial pacing at progressively higher rates and then programmed stimulation with one and two extrastimuli in control state and after isoproterenol infusion. Intracardiac EPS was performed in 49 of them. RESULTS: (1) Study was negative in nine patients; intracardiac EPS remained negative in four of them, induced a VT in five; (2) clinical tachycardia was induced in 44 patients: (a) in 29 of them, atrial pacing induced a BBB similar to aberrancy noted in tachycardia and the diagnosis of SVT with aberrancy was made; (b) in 15 patients, QRS complex remained narrow during atrial pacing; the diagnosis of VT was made in presence of AV dissociation and confirmed by intracardiac study. VT was induced by atrial or ventricular stimulation or was spontaneous during isoproterenol infusion. VT mechanism were bundle branch reentry [Am. J. Cardiol. 65 (1990) 322], verapamilsensitive VT [Am. J. Cardiol. 65 (1990) 322], catecholamine-sensitive VT [J. Cardiovasc. Electrophysiol. 7 (1996) 2]. Two patients had tachycardias of both natures either supraventricular or ventricular. CONCLUSION: Esophageal EPS was a safe, rapid and economic means to evaluate the mechanism of wide QRS tachycardia in 84% of patients; atrial pacing at progressively higher rates is very simple to reproduce the aberrancy of similar morphology in those patients who had wide-QRS tachycardia related to a SVT with aberrancy. If atrial pacing did not exactly reproduce the aberrancy in tachycardia, a VT should be suspected.

Adolescent↗

PubMed2003

Transitory or permanent regular wide QRS complex tachycardia induced by atrial stimulation in patients without apparent heart disease. Significance.

OBJECTIVES: The purpose of the study was to evaluate the frequency of transitory or permanent bundle branch block (BBB) associated with a paroxysmal tachycardia induced by atrial stimulation in patients without heart disease and its significance. METHODS: Esophageal atrial stimulation was performed in 447 patients suspected to have supraventricular tachycardias (SVT). Sustained regular tachycardia was induced in all of them but three, either in control state (75%) or after administering isoproterenol. In 346 patients, only narrow complex SVTs were induced (77%); in 259 of them, the reentry occurred in the AV node and in remaining patients within a concealed accessory pathway. In 62 patients, a transitory functional BBB was recorded at the onset of the tachycardia (14%). In 33 of them, the reentry occurred in the AV node and in the remaining 29 patients within a concealed accessory pathway. In 36 patients (8%), a permanently wide QRS complex tachycardia was induced. Three patients had also inducible narrow complex SVT. Atrial pacing induced a BBB similar to the aberrancy in tachycardia in 22 patients: the reentry occurred in the AV node in 17 patients, within a concealed accessory pathway in three patients and in a Mahaim bundle in two patients. In other patients, QRS complex remained normal during atrial pacing: all 14 patients had a ventricular tachycardia (VT), either a verapamil-sensitive VT (n = 7) or catecholamine-sensitive VT (n = 4) or bundle branch reentry (n = 3). Followed from 2 to 12 years, the prognosis of these patients was excellent. CONCLUSION: Transitory BBB at the onset of an SVT is noted in 14% of the population, is more frequent in patients with accessory pathway reentrant tachycardia, but is helpful for this diagnosis in only 12% of cases. A regular tachycardia with permanent left or right bundle branch morphology induced by atrial stimulation in a patient without heart disease and without BBB during atrial pacing is due to a VT even if this patient has also narrow complex tachycardias. This mechanism does not affect the excellent prognosis of this population.

Adolescent↗

PubMed2002

Identification and characterization of a novel ABCA subfamily member, ABCA12, located in the lamellar ichthyosis region on 2q34.

The ABCA subfamily of ABC transporters includes ten members to date. In this study, we describe an additional gene, ABCA12. Four full-length cDNA sequences have been obtained from human placenta that contain two different polyadenylation sites and two splicing forms, coding for ABCA12 isoforms of 2,595 and 2,516 amino acid residues. Both isoforms are predicted to have two ATP-binding domains (nucleotide binding domain, NBD) and two transmembrane (TM) domains, features shared by all other ABCA subfamily proteins. ABCA12 is most closely related to ABCA1, with an amino acid similarity of 47%. Northern blot analysis demonstrates that a 9.5-kb transcript is mainly expressed in the stom- ach. ABCA12 was mapped to human chromosome 2q34. Two other genes from ABCA subfamily are associated with human inherited diseases, ABCA1 with the cholesterol transport disorders Tangier disease and familial hypoalphalipoproteinemia, and ABCA4 with several retinal degeneration disorders. The ABCA12 gene is located in a region of chromosome 2q34 that harbors the genes for lamellar ichthyosis, polymorphic congenital cataract, and insulin-dependent diabetes mellitus (IDDM13), and therefore is a positional candidate for these pathologies.

ATP-Binding Cassette Transporters↗

PubMed2002

The human ATP binding cassette gene ABCA13, located on chromosome 7p12.3, encodes a 5058 amino acid protein with an extracellular domain encoded in part by a 4.8-kb conserved exon.

The ABCA subfamily of ATP-binding cassette (ABC) transporters includes eleven members to date. In this study, we describe a new, unusually large gene on chromosome 7p12.3, ABCA13. This gene spans over 450 kb and is split into 62 exons. The predicted ABCA13 protein consists of 5,058 ami- no acid residues making it the largest ABC protein described to date. Like the other ABCA subfamily members, ABCA13 contains a hydrophobic, predicted transmembrane segment at the N-terminus, followed by a large hydrophilic region. In the case of ABCA13, the hydrophilic region is unexpectedly large, more than 3,500 amino acids, encoded by 30 exons, two of which are 4.8 and 1.7 kb in length. These two large exons are adjacent to each other and are conserved in the mouse Abca13 gene. Tissue profiling of the major transcript reveals the highest expression in human trachea, testis, and bone marrow. The expression of the gene was also determined in 60 tumor cell lines and the highest expression was detected in the SR leukemia, SNB-19 CNS tumor and DU-145 prostate tumor cell lines. ABCA13 has high similarity with other ABCA subfamily genes which are associated with human inherited diseases: ABCA1 with the cholesterol transport disorders Tangier disease and familial hypoalphalipoproteinemia, and ABCA4 with several retinal degeneration disorders. The ABCA13 gene maps to chromosome 7p12.3, a region that contains an inherited disorder affecting the pancreas (Shwachman-Diamond syndrome) as well as a locus involved in T-cell tumor invasion and metastasis (INM7), and therefore is a positional candidate for these pathologies.

ATP-Binding Cassette Transporters↗

PubMed1999

Delayed gastric emptying after pancreaticoduodenectomy and pancreaticogastrostomy.

OBJECTIVE: To find out which factors influence the development of delayed gastric emptying (DGE) after pancreaticoduodenectomy with pancreaticogastrostomy. DESIGN: Prospective clinical study. SETTING: University hospital, France. SUBJECTS: 88 patients of 103 consecutive patients who had had pancreaticoduodenectomies, November 1991-November 1997. INTERVENTIONS: Whipple resection, and parenteral and enteral nutrition. MAIN OUTCOME MEASURES: Mortality, morbidity, and development of DGE (defined as the need for a postoperative nasogastric tube for 10 days or longer). RESULTS: One patient died, and 44 developed postoperative complications. 36 patients (41%) developed DGE in 21 of whom (58%, 24% of the total) it was in isolation, with no other complication; and 52 (59%) did not. There were significant differences between those who developed DGE and those who did not: 30 men (83%) compared with 6 women (17%) developed DGE compared with 32 (62%) and 20 (38%) (p = 0.03;); 15 (42%) developed a complication as well as DGE compared with 8 (15%) (p = 0.005); 10(28%) who developed DGE required reoperation compared with 4(8%) (p = 0.011); mean (SD) hospital stay was 30(12) days among those with DGE compared with 17 (5) days (p= 0.0001); and their mean (SD) serum protein concentration on day 1 was 46 (1) compared with 51 (7) g/L (p=0.01). Multivariate analysis showed that three factors independently influenced the development of DGE: sex (p = 0.01), the need for reoperation (p = 0.03) and the mean serum protein concentration on day 1 (p = 0.04). CONCLUSION: Postoperative complication and the need for reoperation remain the most common factors linked to the development of DGE. However, in a quarter of patients DGE was not associated with any postoperative complication.

Digestive System Surgical Procedures↗

PubMed1999

[Disseminated histoplasmosis detected by lingual and tonsillar erosions in an immunocompetent patient].

BACKGROUND: Histioplasmosis is a usually asymptomatic fungal infection. In the immunocompetent patient, it leads to chronic disseminated infection. Mucosal involvement is common and can provide the diagnosis. CASE REPORT: A metropolitan Frenchman with a history of alcoholism and smoking and living in Guyana consulted for lingual and tonsil erosion. Squamous cell carcinoma was suspected but not confirmed at pathology. The patient had a bi-apical infiltration on the chest x-ray and was treated empirically for tuberculosis. The diagnosis of histoplasmosis was reached when rare Histoplasma capsulatum were evidenced from a buccal swab. Itraconazole led to cure in 6 months. DISCUSSION: This case illustrates the importance of mucosal signs in the diagnosis of disseminated histoplasmosis in immunocompetent subjects. Histoplasmosis is rarely the cause of active infection in immunocompetent subjects. In these patients, the fungal infection generally progresses to chronic dissemination. Mucosal signs are frequent in this form but are rare in case of cutaneous histoplasmosis. Itraconazole (200 mg/d) is indicated for 6 months.

Alcoholism↗

PubMed1996

[Should protocol of programmed ventricular stimulation be adapted to each patient? ].

The authors report the case of a 56 year old patient in whom the mechanisms of a wide QRS complex tachycardia recorded on an intensive care monitor could not be determined. The patient also had episodes of atrial flutter with left bundle branch block. Programmed ventricular stimulation with 3 extrastimuli triggered a non-specific ventricular flutter. One week later, the patient was resuscitated from a cardiac arrest which was undocumented. It was therefore important to elucidate the mechanism of the initial tachycardia. A second session of programmed ventricular stimulation was undertaken. As the use of 2 extrastimuli triggered runs of unsustained polymorphic ventricular tachycardia, the classical protocol was stopped. An infusion of low-dose isoproterenol was used to repeat programmed stimulation with a single extrastimulus. This protocol triggered sustained monomorphic ventricular tachycardia at 240/min. The diagnosis of ventricular tachycardia could therefore be continued.

Cardiac Pacing, Artificial↗

PubMed1996

[Antigenic retrieval using a pressure cooker].

This technical note describes antigen retrieval procedures using a pressure cooker. These procedures are perfectly adapted to routine immunohistochemistry and improve the overall quality of immunostaining.

Antigens↗

PubMed1994

[Focus on smoking].

Explore the source record for details and available documents.

Administration, Cutaneous↗

PubMed1993

Tumor necrosis factor alpha in human kidney transplant rejection--analysis by in situ hybridization.

Macrophagic infiltration and necrosis of rejected kidney transplants represent two pejorative patterns. It has been assumed that the macrophagic toxicity is mediated partly by secretion of tumor necrosis factor alpha. On the other hand, TNF is also involved in many inflammatory and immunological phenomena. We thus evaluated the expression of TNF mRNA by in situ hybridization in 6 rejected kidney transplants using a radiolabeled TNF-c DNA probe. Then the synthesis of TNF alpha protein was studied by immunohistochemistry using an anti-TNF alpha antibody. In severely rejected kidney grafts, TNF mRNA is expressed in some monomorphic infiltrating cells, mostly located in the deepest part of the cortex and around the tubes. These cells do not bind other probes, such as dopa-decarboxylase DNA or preproenkephalin RNA. They are also recognized by a monoclonal antibody directed against TNF alpha. What is more, this antibody binds with some glomerular endothelial and tubular epithelial cells that do not express TNF mRNA. These cells are likely target cells for TNF. In the normal kidney, there are no cells expressing TNF-alpha mRNA.

Gene Expression↗

PubMed1992

Transfection and expression of a gene coding for a human melanoma antigen recognized by autologous cytolytic T lymphocytes.

Human melanoma line MZ2-MEL expresses several antigens recognized by autologous cytolytic T lymphocytes (CTL). As a first step towards the cloning of the gene coding for one of these antigens, we tried to obtain transfectants expressing the antigen. The DNA recipient cell was a variant of MZ2-MEL which had been selected with a CTL clone for the loss of antigen E. It was cotransfected with genomic DNA of the original melanoma line and with selective plasmid pSVtkneo beta. Geneticin-resistant transfectants were obtained at a frequency of 2 x 10(-4). These transfectants were then screened for their ability to stimulate the production of tumor necrosis factor by the anti-E CTL clone. One transfectant expressing antigen E was identified among 70,000 drug-resistant transfectants. Its sensitivity to lysis by the anti-E CTL was equal to that of the original melanoma cell line. When this transfectant was submitted to immunoselection with the anti-E CTL clone, the resulting antigen-loss variants were found to have lost several of the transfected pSVtkneo beta sequences. This indicated that the gene coding for the antigen had been integrated in the vicinity of pSVtkneo beta sequences, as expected for cotransfected DNA.

Antigens, Neoplasm↗

PubMed1992

[Comparative contribution of endoscopy, x-ray computed tomography and MRI in the preoperative evaluation of cancers of the endolarynx: apropos of 18 surgically-treated patients].

The authors carried out a prospective and comparative study of 18 patients with endolaryngeal carcinoma, with preoperative imaging of the extent of the disease by computed tomography (CT) and magnetic resonance imaging (MRI). The correlations between CT, MRI, endoscopy and postoperative histology are reported. It appears to the authors that the contribution of imaging is evident and that at present the reliability of CT is comparable to that of MRI, taking account of the current technical problems of MRI.

Adult↗

PubMed1992

[Olfactory esthesioneuroma. Apropos of 12 cases].

The authors report a 12-case series of olfactory esthesioneuromas, in which they review the main characteristics of this rare tumor. The olfactory esthesioneuroma diagnosis should be evoked for all nasal tumors, especially for tumors originating in a high position. This diagnosis is confirmed by the difficult pathological examination, which currently benefits widely from immunohistochimy. Prognosis is poor and surgery is the main treatment, associated with varying degrees of radiotherapy. As far as chemotherapy is concerned, its role must be clarified.

Adult↗

PubMed1991

[Tumor necrosis factor in graft rejection. In situ hybridization study].

The development of necrosis and macrophage infiltration increases the risk of renal graft rejection. But the macrophages secrete the alpha form of the tumour necrosing factor (TNF) which is also involved in several immunologic and inflammatory phenomena. We therefore studied the expression of the gene TNF alpha by in situ hybridization during advanced stage rejection after renal transplantation: the grafts were infiltrated with macrophage-like cells expressing the mRNA of the TNF alpha gene, particularly deep in the cortex and in the medulla. These cells then secrete the TNF alpha molecule since they are recognized by anti-TNF alpha antibodies. These antibodies also recognize certain other glomerular endothelial and tubular epithelial cells which do not express the TNF alpha gene: these cells are undoubtedly the TNF target cells. These findings confirm the synthesis of TNF alpha in advanced stage renal graft rejection.

Colorectal Neoplasms↗

PubMed1989

Presence on a human melanoma of multiple antigens recognized by autologous CTL.

We derived from blood lymphocytes of a melanoma patient a large number of cytolytic T-cell clones directed against a cell line of the autologous tumor. Three distinct groups of antigens were recognized by these CTL on the autologous melanoma cells: group A consisted of stable antigens present on all sublines, whereas antigens B and C appeared unstable and were expressed by distinct sublines. In vitro immunoselections with various anti-A CTL clones were applied to the melanoma cells and variants resistant to 3 different CTL clones were obtained. These variants remained sensitive to other anti-A CTL clones, indicating that group A comprises at least 4 different antigens (D, E, F and A'). From a total of 76 CTL clones obtained from lymphocytes collected from the patient at various times, we found that 45 were anti-B, 17 were anti-C, 2 were anti-D, 9 were anti-E, 2 were anti-F and I was anti-A'. It is therefore likely that the 6 antigens identified by these CTL clones represent all or nearly all the transplantation antigens recognized by autologous CTL on this human melanoma.

Antigens, Neoplasm↗