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C Pelletier

Publications and source records attributed to C Pelletier.

At least 19 recordsLinked to original sources
PubMed2006

Six methodological steps to build medical data warehouses for research.

PURPOSE: We propose a simple methodology for heterogeneous data collection and central repository-style database design in healthcare. Our method can be used with or without other software development frameworks, and we argue that its application can save a relevant amount of implementation effort. Also, we believe that the method can be used in other fields of research, especially those that have a strong interdisciplinary nature. BACKGROUND: The idea emerged during a healthcare research project, which consisted among others in grouping information from heterogeneous and distributed information sources. We developed this methodology by the lessons learned when we had to build a data repository, containing information about elderly patients flows in the UK's long-term care system (LTC). DESIGN: We explain thoroughly those aspects that influenced the methodology building. The methodology is defined by six steps, which can be aligned with various iterative development frameworks. We describe here the alignment of our methodology with the RUP (rational unified process) framework. The methodology emphasizes current trends, as early identification of critical requirements, data modelling, close and timely interaction with users and stakeholders, ontology building, quality management, and exception handling. RESULTS: Of a special interest is the ontological engineering aspect, which had the effects with the highest impact after the project. That is, it helped stakeholders to perform better collaborative negotiations that brought better solutions for the overall system investigated. An insight into the problems faced by others helps to lead the negotiators to win-win situations. We consider that this should be the social result of any project that collects data for better decision making that leads finally to enhanced global outcomes.

Computer Communication Networks↗
PubMed2006

Validation of an internal method for the diagnosis of infections with Chlamydophila abortus and Coxiella burnetii by real-time multiplex PCR.

Chlamydophila abortus and Coxiella burnetii are one of the major pathogens implicated in abortion in cattle. Their characteristic of obligate intracellular bacteria, and of zoonotic agents, makes their culture difficult in diagnostic laboratories, and the traditional tools of diagnosis (detection of sera antibodies by ELISA, Stamp's coloration) encounter specificity, sensitivity and interpretability limits. Individual PCR have recently been developed. Nevertheless, their income/cost is a limiting factor for breeders. As the symptoms are not specific, the request for analysis often concerns the two valences. Consequently, the development and the validation of an internal multiplex PCR appears to be a suitable solution.

Abortion, Veterinary↗
PubMed2005

Randomised trial of ambulatory oxygen in oxygen-dependent COPD.

Long-term oxygen therapy may limit a patient's ability to remain active and may be detrimental to the rehabilitation process. This study aimed to determine the effect of ambulatory oxygen on quality of life and exercise capacity in patients with chronic obstructive pulmonary disease fulfilling the usual criteria of long-term oxygen therapy. In a 1-yr, randomised, three-period, crossover trial, 24 patients (mean age 68 yrs; mean arterial partial pressure of oxygen at rest 7.1 kPa (53 mmHg)) were allocated to one of the six possible sequences generated by three interventions: 1) standard therapy (home oxygen therapy with an oxygen concentrator only); 2) standard therapy plus as-needed ambulatory oxygen; and 3) standard therapy plus ambulatory compressed air. The comparison of ambulatory oxygen versus ambulatory compressed air was double blind. The main outcomes were quality of life (Chronic Respiratory Questionnaire), exercise tolerance (6-min walk test) and daily duration of exposure to oxygen therapy. The trial was stopped prematurely after an interim analysis. On average, the patients used few ambulatory cylinders (7.5 oxygen cylinders versus 7.4 compressed air cylinders over a 3-month study period). Ambulatory oxygen had no effect on any of the outcomes. In conclusion, the current results do not support the widespread provision of ambulatory oxygen to patients with oxygen-dependent chronic obstructive pulmonary disease.

Aged↗
PubMed2005

Crossing heterogeneous information sources for better analysis of health and social care data.

In this paper we describe a methodology that emerged during an implementation of a health-and-social-care-oriented data repository, which consists in grouping information from heterogeneous and distributed information sources. We developed this methodology by first constructing a concrete data repository, containing information about elderly patients flows in the UK's long-term care (LTC) system. In our specific case, the role of the data repository is to allow knowledge extraction about consumption and behavioural tendencies in the elderly people population within the LTC system. These tendencies can be depicted in terms of survival behaviour (modelling), cost evolution, and bed use. Other types of knowledge that can be extracted are typical patient profiles, placement policy in term of rules and criteria effectively applied and, specific features of the business process behind the long-term care provision. A well-constructed data repository can support the discovery (analysis) of hidden aspects about the way patients are placed and accepted in the LTC, and also how the allocated resources are consumed. We argue that the use of this methodology could save time in similar undertakings or in other fields than health and social care.

Humans↗
PubMed2004

[Black oesophagus, a rare event in intensive care unit].

We report a new case of acute necrotizing oesophagitis, diagnosing on a patient hospitalised in intensive care unit. This pathology is still a rare event; the definition excludes patients with a history of recent caustic ingestion. Oesophageal necrosis can be diagnosed at endoscopy by the presence of black necroting appearing oesophagus. Contrary to the caustic oesophagitis whose treatment is often surgical, treatment of the acute necrotizing oesophagitis is primarily medical. The prognosis for patients who develop acute necrotizing oesophagitis is generally poor, even if one can hope for the cure without after-effect of it.

Abdominal Neoplasms↗
PubMed2004

Thermogenesis and weight loss in obese individuals: a primary association with organochlorine pollution.

The main objective of this study was to investigate the potential impact of body organochlorine (OC) pollution on the adaptive change in thermogenesis induced by body weight loss. Fat mass (FM), fat-free mass (FFM), and sleeping metabolic rate (SMR) were measured in obese individuals before and after a weight-reducing program. The measured values of SMR were then compared to those predicted from a reference equation established from FM and FFM in control subjects. Plasma OC, leptin, total tri-iodothyronine, and free thyroxine concentrations were also measured in obese subjects before and after weight loss. After weight loss, the measured decrease in SMR was greater than that predicted by changes in FM and FFM. Increased plasma OC concentration was the factor explaining the greatest proportion of the difference between predicted and measured SMR changes induced by body weight loss. OC pollution seems to be a new factor affecting the control of thermogenesis in some obese individuals experiencing body weight loss.

Adult↗
PubMed2004

Occurrence and significance of filamentous bacteria in pulp and paper activated sludge systems.

A microbial survey of 27 activated sludge (AS) systems included 16 conventional activated sludge (CAS) systems, five sequential batch reactors (SBR) and six oxygen-activated sludge (OAS) systems, all treating pulp and paper effluents. The most prevalent filaments observed were Thiothrix (26%) and Type 021N (22%). The designs of the activated sludge systems seemed to have an effect on the filament types. We found Thiothrix to be the most common filament associated with bulking. For CAS systems, a completely mixed mode of operation promoted Thiothrix and Type 021N growth. Type 021N was favoured in CAS systems with food to microorganism (F/M) ratios higher than 0.2, and with dissolved oxygen (DO) residuals higher than 2 ppm, while Thiothrix generally proliferated at lower F/M ratio and DO residuals. Nutrient deficiencies as well as nutrient dosage variations were suspected in most of the systems having Thiothrix and Type 021N as the most prevalent filaments. Thiothrix appeared to prefer polyphosphate and/or ammonia rather than urea/phosphoric acid as N and P sources. Systems with aerobic selectors showed the lowest filament counts, while systems with no selectors showed the highest filament counts.

Environmental Monitoring↗
PubMed2003

Energy balance and pollution by organochlorines and polychlorinated biphenyls.

Organochlorines are fat-soluble chemical compounds resistant to degradation, so they are stored in the adipose tissue of practically every organism on the planet, including humans. Accumulation of these compounds in the body seems to be related to fat mass, obese individuals having a higher plasma organochlorine concentration than lean subjects. During body weight loss, lipid mobilization and a decrease in fat mass result in increased concentrations of organochlorines in plasma and adipose tissue. Organochlorines may have adverse health effects. For example, they have been associated with altered immune and thyroid functions and with some types of cancer. As these compounds may reach their target organs whilst in the circulation, their increase in plasma during weight loss might be associated with some physiological changes occurring during weight loss. Relationships have indeed been reported among weight loss-induced increase in plasma organochlorine concentration and decreased triiodothyronine (T3) concentration, resting metabolic rate, and skeletal muscle markers for fat oxidation. Although further studies are needed to assess the causality of these relationships, they raise concern about some potential undesirable effects of weight loss. Indeed, the effects of organochlorines on energy balance could complicate body weight loss and even favour weight regain. These notions lend support for weight-loss strategies favouring a moderate weight loss, which would reduce risks for cardiovascular diseases, diabetes and hypertension, without resulting in a substantial release of organochlorines.

Adipose Tissue↗
PubMed2001

H2O2 impairs inflammatory mediator release from immunologically stimulated RBL-2H3 cells through a redox-sensitive, calcium-dependent mechanism.

OBJECTIVES: In this study we examined the effects of the inflammatory agent hydrogen peroxide (H2O2) on IgE-mediated mast cell responses. MATERIALS AND METHODS: Release of preformed granular mediators and newly synthesised TNF-alpha were measured in the RBL-2H3 mast cell line stimulated through IgE receptors (FcepsilonRI) in the presence of varying concentrations of H2O2. The sensitivity of the intracellular calcium response to H2O2 exposure was investigated. RESULTS: We found that H2O2 treatment impaired the release of preformed and newly synthesised mediators. H2O2 treatment simultaneously led to a profound inhibition of the calcium response. Calcium fluxes from both intra- and extracellular sources were impaired. H2O2 action was dependent on the intracellular redox state. Receptor activation directly stimulated intracellular H2O2 production. CONCLUSION: While in many cells H2O2 induces potent inflammatory responses we show that it can be an anti-inflammatory agent by not only inhibiting the release of preformed mediators but also by affecting the secretion of newly synthesized TNF-alpha. Inhibition is a consequence of the profound effect on intracellular calcium levels. The activation of an intracellular oxidative burst by FcepsilonRI aggregation and the sensitivity of intracellular responses to redox-altering agents point to an important regulatory mechanism of mast cell responses in inflammatory tissues.

Adjuvants, Immunologic↗
PubMed2000

A colony immunoblotting method for quantitative detection of a Bifidobacterium animalis probiotic strain in human faeces.

A colony immunoblotting method has been developed to allow detection of the probiotic Bifidobacterium animalis strain DN-173 010 in human faecal samples. Rabbits were immunized with heat-killed DN-173 010 bacteria resulting in the production of an antiserum highly specific for bacteria belonging to Bif. animalis species. Of the 89 strains representative of 29 different bifidobacterial species tested, only the 15 strains of the Bif. animalis species could be detected with the antiserum. In Western immunoblotting the serum reacts with a protein of 45-kDa apparent molecular weight. None of the bacteria classically encountered in human faecal samples and able to grow on non-selective Columbia blood agar (enterobacteria, Bacteroides or Lactobacillus for instance) reacted with the antiserum. Taking advantage of the high specificity of the antiserum and of the absence of Bif. animalis bacteria in faeces samples of five human volunteers, we demonstrated that strain DN-173 010 survives the intestinal transit. Being based on a combination of semiselective cultivation and colony immunoblotting techniques, the method allowed detection of the Bif. animalis strain even when it represented only one thousandth of the total bifidobacterial population.

Animals↗
PubMed1999

Unilateral proptosis in an immunocompetent man as the initial clinical manifestation of systemic Hodgkin disease.

OBJECTIVE: Orbital involvement in Hodgkin disease (HD) is rare. Previously reported cases of HD in patients without the acquired immunodeficiency syndrome have been diagnosed late in the course of established systemic disease. The authors describe an immunocompetent man with orbital infiltration as the initial manifestation of systemic HD. DESIGN: Case report. PARTICIPANTS: A 47-year-old man with acute progressive, painless proptosis of the left eye is described. INTERVENTION: A well-defined, homogeneous soft tissue mass of the superior left orbit was evident on computed tomography, and an incisional biopsy of the nontender mass was performed. RESULTS: The histopathologic findings were characteristic of HD. Systemic investigations showed clinical stage 3A HD. Ten months after completion of hybrid chemotherapy, the patient remained in complete remission from his HD. CONCLUSION: Hodgkin disease presenting initially in the orbit of a patient with the acquired immunodeficiency syndrome has been described previously. The patient presented in this report is the first case of HD in the recent English literature with the initial manifestation in the orbit of an otherwise immunocompetent patient.

Acute Disease↗
PubMed1998

Fc epsilonRI-mediated induction of TNF-alpha gene expression in the RBL-2H3 mast cell line: regulation by a novel NF-kappaB-like nuclear binding complex.

Using rat basophilic leukemia (RBL-2H3) cells as a model, we investigated how aggregation of the high affinity receptor for IgE (Fc epsilonRI) regulates TNF-alpha gene expression. Antigenic stimulation of RBL-2H3 cells led to an increase in newly synthesized TNF-alpha mRNA that was dependent on continuous receptor aggregation and did not require de novo protein synthesis. Kinetic analysis showed that maximal levels were achieved at 60 min and waned by 180 min of stimulation. Concomitant with the transcriptional activation of the TNF-alpha gene, the rapid appearance and disappearance of a previously uncharacterized nuclear NF-kappaB DNA binding activity, comprised of two distinct protein complexes, were observed. These protein complexes bound to NF-kappaB sites within the TNF-alpha gene and contained novel proteins (three species of Mr between 90,000-110,000) distinct from the classical proteins in NF-kappaB complexes. The induced NF-kappaB binding activity required continuous receptor stimulation and induced NF-kappaB-dependent reporter gene expression. Consistent with a role for the novel NF-kappaB nuclear binding activity in TNF-alpha gene expression, deletion of several 5' kappaB elements in the TNF-alpha promoter abolished all measurable Fc epsilonRI-dependent induction of a reporter construct. Pharmacologic agents that inhibited the NF-kappaB binding activity also inhibited TNF-alpha mRNA expression. Our results demonstrate that a novel NF-kappaB-like nuclear binding activity plays an important role in regulation of the rapid and transient transcriptional activation of the TNF-alpha gene via Fc epsilonRI.

Animals↗
PubMed1998

Specific signaling pathways in the regulation of TNF-alpha mRNA synthesis and TNF-alpha secretion in RBL-2H3 mast cells stimulated through the high affinity IgE receptor.

OBJECTIVE: In the present study, we investigated signal transduction pathways involved in TNF-alpha gene expression and TNF-alpha secretion by mast cells stimulated through the high affinity IgE receptor (FcepsilonRI). MATERIALS AND METHODS: TNF-alpha mRNA steady state levels and TNF-alpha secretion in the presence of specific pharmacological agents were monitored using rat basophilic leukemia cells (RBL-2H3) stimulated through FcepsilonRI. Relative amounts of TNF-alpha mRNA versus beta-actin levels were quantified by RNase protection and RT-PCR assays. TNF-alpha secretion was measured by a current ELISA test. RESULTS: We show that EGTA (5 mM) prevented TNF-alpha mRNA expression and TNF-alpha secretion in antigen-stimulated cells. The protein kinase C (PKC) inhibitor bisindolylmaleimide I substantially blocked TNF-alpha secretion at 2 microM but had only a marginal effect on TNF-alpha mRNA expression. The results were similar when PKC isoforms were depleted by long-term exposure to 100 nM phorbol ester (PMA). The PI 3-kinase inhibitor wortmannin blocked TNF-alpha secretion at low doses (EC50= 13 nM), but only partially affected mRNA expression. CONCLUSIONS: Our results show that in FcepsilonRI-stimulated RBL-2H3 cells calcium mobilization, activation of PKC and PI 3-kinase are necessary for TNF-alpha secretion while for the increased TNF-alpha mRNA expression PKC activity is dispensable and PI 3-kinase activity only partially required.

Androstadienes↗
PubMed1998

Ptosis in Waldenström's macroglobulinemia.

PURPOSE: To report a case of chronic, progressive unilateral blepharoptosis in a 73-year-old woman with Waldenström's macroglobulinemia. METHOD: Case report. A biopsy was performed on a thickened and indurated tarsal plate that we believed had resulted in mechanical blepharoptosis. RESULTS: Histologic and immunohistochemistry studies of the biopsy specimen demonstrated a lymphoplasmacytoid cell infiltrate with monoclonal antibodies consistent with Waldenström's macroglobulinemia. CONCLUSION: Involvement of the tarsal conjunctiva and tarsus in Waldenstrom's macroglobulinemia is a newly recognized cause of eyelid thickening and ptosis.

Aged↗
PubMed1998

Twelve-year experience with Carpentier-Edwards PERIMOUNT pericardial valve in the mitral position: a multicenter study.

BACKGROUND AND AIMS OF THE STUDY: The study aim was to assess the durability of the Carpentier-Edwards PERIMOUNT pericardial bioprosthesis in the mitral position. METHODS: This seven-center retrospective clinical study involved the follow up of 333 patients who underwent isolated mitral valve replacement and 102 patients who underwent double (mitral and aortic) valve replacement with the PERIMOUNT pericardial valve between 1984 and 1989. Mean patient age at implant was 60.7 +/- 11.6 years; 41.1% were males. The most common etiology was rheumatic heart disease (53.9%) and the most common mechanism mitral insufficiency. All patients but six were followed for an average of 7.2 +/- 3.6 years after surgery; total follow up was 3071.7 patient-years (pt-yr). RESULTS: The total operative mortality rate was 7.6%; this included a valve-related mortality rate of 0.2%. The late mortality rate was 5.2% per pt-yr, of which 1.4% per pt-yr was considered valve-related. At 11 years, the overall actuarial survival rate was 53.3 +/- 2.8%, and actuarial freedom from valve-related death 83.9 +/- 2.6%. At follow up, 80% of patients were in NYHA class I or II, and 74% showed improvement. Twenty-eight incidences of deterioration requiring explant were observed. At 11 years the actuarial freedom from explant due to structural failure was 84.9 +/- 3.1%. Rates of structural failure decreased with age: the actuarial freedom from explant due to structural failure was 78.1 +/- 4.8% for patients aged < or = 60 years, 89.4 +/- 4.4% for those aged 61-70 years, and 100% for those aged over 71 years. CONCLUSION: The Carpentier-Edwards PERIMOUNT pericardial bioprosthesis is a reliable choice when a tissue valve is required, especially in patients over 60 years of age.

Bioprosthesis↗
PubMed1997

Epidemiological study of Candida spp. colonization in cardiovascular surgical patients.

Candida infections involve multiple risk factors. Among the independent risk factors identified, the degree of colonization of Candida spp. allows the prediction of subsequent severe candidosis in surgical patients. The aim of this study was to assess among 13 selected variables, those that would best predict the perioperative variation of the colonization index (CI) of Candida spp. in cardiovascular surgical patients. The colonization index took into account the number of sites colonized and the density of growth. The results showed that 56.8% of our patients were colonized perioperatively. A total of 116 isolates were identified and Candida albicans accounted for 76.7% of the strains. Among the patients who developed post-surgical Candida infections, 57.1% had an increase of the CI early after the operation. By univariate analysis, three factors were significantly associated with an increase of the CI in patients after surgery; sex (female), the duration of central intravascular catheterization and the length of stay in the surgical intensive care unit (SICU). Epidemiological data could help predict those patients who are at risk of developing Candida infections.

Aged↗
PubMed1997

Cell surface characteristics of Lactobacillus casei subsp. casei, Lactobacillus paracasei subsp. paracasei, and Lactobacillus rhamnosus strains.

Hydrophilic and electrostatic cell surface properties of eight Lactobacillus strains were characterized by using the microbial adhesion to solvents method and microelectrophoresis, respectively. All strains appeared relatively hydrophilic. The strong microbial adhesion to chloroform, an acidic solvent, in comparison with microbial adhesion to hexadecane, an apolar n-alkane, demonstrated the particularity of lactobacilli to have an important electron donor and basic character and consequently their potential ability to generate Lewis acid-base interactions with a support. Regardless of their electrophoretic mobility (EM), strains were in general slightly negatively charged at alkaline pH. A pH-dependent behavior concerning cell surface charges was observed. The EM decreased progressively with more acidic pHs for the L. casei subsp. casei and L. paracasei subsp. paracasei strains until the isoelectric point (IEP), i.e., the pH value for which the EM is zero. On the other hand, the EM for the L. rhamnosus strains was stable from pH 8 to pH 3 to 4, at which point there was a shift near the IEP. Both L. casei subsp. casei and L. paracasei subsp. paracasei strains were characterized by an IEP of around 4, whereas L. rhamnosus strains possessed a markedly lower IEP of 2. The present study showed that the cell surface physicochemical properties of lactobacilli seem to be, at least in part and under certain experimental conditions, particular to the bacterial species. Such differences detected between species are likely to be accompanied by some particular changes in cell wall chemical composition.

Acetates↗