Publications by authors named "Lavigne J"

Formation of a highly fluorescent composite formed from the biotinylated PPE 3 and streptavidin covered polystyrene microspheres is reported.

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Objective: To determine the pharmacokinetics and efficacy of tobramycin against pulmonary infections of Pseudomonas aeruginosa in rats after intratracheal administration of conventional and liposomal formulations.

Methods: Male Sprague-Dawley rats were inoculated with 10(6) cfu of a mucoid variant of P. aeruginosa (MIC of tobramycin for PA 508 = 1 mg/l) and tobramycin (conventional or liposomal formulations) was administered in single (490 microg) and multiple dose (490 microg during 4 days) experiments.

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The first ever case of spondylodiscitis caused by Clostridium ramosum in an elderly immunocompetent patient has been reported. C. ramosum is usually an intestinal bacterium but may occasionally be isolated in clinical specimens as an opportunistic pathogen.

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Objectives: in patients with vascular prosthesis infection, to compare surgical outcome and long-term results of cryopreserved allograft implantations to conventional surgery.

Design: retrospective study.

Material And Methods: two asynchronous series of 44 [series I: 1980-1994; 8 patients with aortoenteric fistula (AEF)] and 22 (series II: 1994-1997; 4 patients with AEF) patients were treated for prosthesis infection.

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Background: Mutations in fibroblast growth factor 23 (FGF-23) cause autosomal dominant hypophosphatemic rickets. Clinical and laboratory findings in this disorder are similar to those in oncogenic osteomalacia, in which tumors abundantly express FGF-23 messenger RNA, and to those in X-linked hypophosphatemia, which is caused by inactivating mutations in a phosphate-regulating endopeptidase called PHEX. Recombinant FGF-23 induces phosphaturia and hypophosphatemia in vivo, suggesting that it has a role in phosphate regulation.

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We evaluated the effects of diet on intestinal tumorigenesis in male Apc(Min) mice by comparing AIN-76A diet fed ad libitum (CON); calorie intake restricted by 40% of the CON (CR); diet high in olive oil and supplemented with freeze-dried fruit and vegetable extracts (OFV); and diet high in total fat (HF). Compared with CON, the frequency of intestinal polyps was reduced by 57% by CR (P < 0.001) and by 33% OFV diet (P = 0.

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Background: Accurate measurements of the concentration of parathyroid hormone (PTH) in serum or plasma are essential for the proper assessment of renal osteodystrophy. The first-generation immunometric PTH assay (1st PTH-IMA) not only detects the intact hormone, but also additional PTH fragments truncated at the amino N-terminally truncated PTH-derived fragments [ntPTH(1-84)]. A second-generation immunometric PTH assay (2nd PTH-IMA) recognizes only PTH(1-84) and possibly PTH fragments that are truncated at the carboxyl-terminus but not PTH(7-84).

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Objective: Oncogenic hypophosphatemic osteomalacia (OOM) is a rare disease characterized by hypophosphatemia, inappropriately low levels of circulating 1,25-dihydroxyvitamin D(3) and osteomalacia. The disease is most commonly caused by benign mesenchymal tumors that produce, among several other factors, fibroblast growth factor-23 (FGF-23). Current evidence thus suggests that this protein has an important role in the regulation of phosphate homeostasis.

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Calorie restriction (CR) is the most effective and reproducible intervention for increasing lifespan in a variety of animal species, including mammals. CR is also the most potent, broadly acting cancer-prevention regimen in experimental carcinogenesis models. Translation of the knowledge gained from CR research to human chronic disease prevention and the promotion of healthy aging is critical, especially because obesity, which is an important risk factor for several chronic diseases, including many cancers, is alarmingly increasing in the Western world.

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Objective: To review studies of psychological adjustment among children and adolescents with chronic arthritis to determine whether they are at more risk for development of adjustment problems than controls.

Methods: We used meta-analytic techniques to review 21 studies reporting overall adjustment problems, internalizing symptoms, externalizing symptoms, or self-concept among youths with arthritis.

Results: Youths with arthritis displayed increased risk for overall adjustment problems and internalizing symptoms, but not for externalizing symptoms or poor self-concept.

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The objective of the present study was to determine the pharmacokinetics and efficacies of liposomal and conventional formulations of tobramycin against Burkholderia cepacia in a model of chronic lung infection. Male Sprague-Dawley rats were inoculated intratracheally with 10(6) CFU of a very resistant strain of B. cepacia (strain BC 1368; MIC, 128 micro g/ml) to establish lung infection.

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The type IV secretion system, encoded by the virB region, is a key virulence factor for Brucella. The 12 genes of the region form an operon that is specifically induced by phagosome acidification in cells after phagocytosis. We speculate that the system serves to secrete unknown effector molecules, which allow Brucella to pervert the host cell endosomal pathways and to create a novel intracellular compartment in which it can replicate.

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Escherichia coli (E. coli) is the most frequent bacterium implicated in community-acquired infection as well as in nosocomial infections. This bacterium is characterised by numerous possibilities to acquire resistance mechanisms, even during antibiotic treatment.

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Porphyrinogenicity of certain xenobiotics depends upon mechanism-based inactivation of specific cytochrome P450 (P450) enzymes, followed by formation of N-alkylprotoporphyrin IX (N-alkylPP). Examination of the porphyrinogenicity of xenobiotics in animals and extrapolation of the results to humans is associated with ambiguity due, in part, to differences between P450 enzymes. The goal of this study was to develop an in vitro test for the detection of N-alkylPPs, produced in human liver after administration of xenobiotics found to be porphyrinogenic in animals.

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Outcomes of a work site disease management program managed by an advanced practice nurse were evaluated. Fifty-four participants were surveyed. A significant number of participants with dyslipidemia and diabetes reported that the program positively changed individual health behaviors.

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Objective: To examine the stability and change in oppositional defiant disorder (ODD) with onset among preschool children in a pediatric sample.

Method: A total of 510 children aged 2-5 years were enrolled initially in 1989-1990 (mean age 3.42 years); 280 participated in five waves of data collection over a period of 48 to 72 months (mean wave 5 age, 8.

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Most synthetic sensors are designed with covalent attachment between a receptor and a reporter moiety. In this report, we describe the current progress of our use of noncovalently attached indicators to signal binding of analytes. With these systems, analyte binding leads to indicator displacement from the binding cavity, which in turn yields an optical signal modulation.

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The routine use of arterial grafts in coronary surgery is facilitated by peroperative adjunction of antispasmodic drug to reduce the event of spasm. Diltiazem has been favoured in most clinical studies devoted to the radial artery graft. The aim of this study was to assess the efficacy of a spasm preventing protocol associating hydrostatic dilation of the graft with a diluted solution of papaverine and nicardipine infusion, starting preoperatively and continued postoperatively in i.

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Many of the major identified risk factors for breast cancer are associated with exposure to endogenous estrogen. In addition to the effects of estrogen as a growth factor, experimental and epidemiological evidence suggest that catechol metabolites of estrogen also contribute to estrogen carcinogenesis by both direct and indirect genotoxic mechanisms. O-Methylation catalyzed by catechol-O-methyltransferase (COMT) is a Phase II metabolic inactivation pathway for catechol estrogens.

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Catechol-O-methyltransferase (COMT) catalyzes the O-methylation of catechol estrogens (CEs), using S-adenosylmethionine (SAM) as a methyl donor. Several studies have indicated that the val108met COMT polymorphism, which results in a 3-4-fold decrease in activity, is associated with increased breast cancer risk. Folate, whose intake levels have also been associated with breast cancer risk, and other micronutrients in the folate metabolic pathway influence levels of SAM and S-adenosylhomocysteine (SAH), a COMT inhibitor generated by the demethylation of SAM.

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Molecular recognition has evolved from a science designed to understand biological systems into a much more diverse area of research. While work continues to elucidate "nature's tricks" with respect to intermolecular interactions, much attention has turned to the perspective that molecular recognition, by design, can lead to new technologies. Applications ranging from molecular sensing to information storage and even working molecular machines have been envisioned.

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The development of a chip-based sensor array composed of individually addressable polystyrene-poly(ethylene glycol) and agarose microspheres has been demonstrated. The microspheres are selectively arranged in micromachined cavities localized on silicon wafers. These cavities are created with an anisotropic etch and serve as miniaturized reaction vessels and analysis chambers.

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Chronic rupture of abdominal aortic aneurysm (AAA) resulting in unusual clinical manifestations can occur if the resistance of structures surrounding the aorta is sufficient to contain hemorrhage. In this report, we describe five cases of chronic ruptured AAA in which the presenting feature was crural neuropathy. All patients were male with a mean age of 74 +/- 1.

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We report the development of a sensor for rapidly and simultaneously measuring multiple sugars in aqueous samples. In this strategy, enzyme-based assays are localized within an array of individually addressable sites on a micromachined silicon chip. Microspheres derivatized with monosaccharide-specific dehydrogenases are distributed to pyramidal cavities anisotropically etched in a wafer of silicon (100) and are exposed to sample solution that is forced through the cavities by a liquid chromatography pumping system.

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[structure in text] The pK(a) values and the geometries of secondary and tertiary amines adjacent to boronic acids were determined using potentiometric and (11)B NMR titrations. The studies showed that the secondary ammonium ion has a pK(a) similar to that of the tertiary ammonium species, which leads to the formation of tetrahedral boron centers at pH values above approximately 5.5.

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