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Biomedical subjects

F Lefèvre

Publications and source records attributed to F Lefèvre.

At least 19 recordsLinked to original sources
PubMed2001

[Drug prescription from the perspective of elderly patients].

INTRODUCTION: Although modern drugs really benefit aged patients, they also entail an increased risk to this population. Elderly people have a particular risk because of using multiple drugs with implies having more adverse reactions. This study aimed to assess elderly patients' relationship with drug prescriptions. METHODS: A descriptive study of a qualitative methods was carried out using semi-structured interviews conducted in an intentional sample of 30 elderly patients living in the urban region of Maringá, Brazil, between February 25 and March 22, 1998. Participants were selected from the Co-Participative Pharmacy Database of the Department of Pharmacy and Pharmacology of the State University of Maringá. The thematic discourse analysis technique was employed for data analysis, using three methodological entities: central idea; key-expressions; and the collective subject's discourse. RESULTS: The average consumption of drugs by this elderly population was 3.6, within a 1-8 interval. The central ideas found in the collective subjects were as follows: I'm able to take them by myself; somebody helps me; I'll take them later; I never forget; there's a need to see the physician; they have never done any harm to me; I'm used to them; sometimes I read it, sometimes I don't; I always manage to buy them; I have already stopped taking them. CONCLUSIONS: More efficient ways of assessing the willingness of elderly patients of complying with the recommended drug therapy and instituting a better drug therapy follow-up must be investigated Further studies of qualitative cut-off should be carried out to understand better the problem and analyze it in depth.

Aged↗
PubMed2001

[Contrast-enhanced MRA of the carotid arteries using 0.5 Tesla: comparison with selective digital angiography].

PURPOSE: To assess the feasability, the imaging quality and the effectiveness of contrast-enhanced MRA (CE MRA) using a 0.5 Tesla MR unit in the evaluation of internal carotid artery (ICA) stenosis. Materials and Methods. 29 patients underwent CE MRA and selective digital substraction angiography (DSA). All data were reviewed in a blinded fashion by 2 independant observers. Imaging quality was graded as good, moderate but interpretable, and insufficient. Stenosis was graded according to the NASCET classification from grade 1 to 4, with the following thresholds:<30%,<70%,<99% and occlusion. Inter and intra- observer agreement was evaluated using the kappa index. RESULTS: Imaging quality was good for 79 arteries, moderate for 24 and insufficient for 13 (k MRA=0.72 and 0.64 respectively for the right and left ICAs). Interobserver agreement was good with values for right/left ICA of 0.84/0.94, 0.72/0.74 respectively for CE-MRA and DSA. For the comparison between CE MRA and DSA, agreement was also good, with values of 0.74 and 0.64 for both readers. Sensitivity of CE MRA in the detection of hemodynamically significant stenosis (>70%) was of 0.95 and 0.94 and specifity of 0.91 and 0.89 respectively for reader n degrees 1 and reader n degrees 2. CONCLUSION: CE MRA using a 0.5T MR unit is a valuable technique in the evaluation of ICA stenosis.

Adult↗
PubMed2000

[Ultrasound contrast agents].

Ultrasound contrast agents are introducing a new vision to ultrasonography. The increase in the Doppler signal intensity improves difficult examinations. Technical failures in the study of transcranial, liver and renal vessel might be rescued with the injection of these new compounds. The introduction of specific image sequences such as harmonic imaging and pulse inversion imaging allows detection of parenchymal enhancement in liver and renal examinations. The injection of ultrasound contrast agents also provides dynamic quantitative information to develop functional imaging. However, it is mandatory to understand the interaction with the ultrasound beam in order to optimise their use and define the adequate ultrasound sequence.

Artifacts↗
PubMed2000

[Bladder candidosis after renal transplantation: contribution of ultrasonography].

Candidosis of the ureter and the bladder is an infrequent complication after renal transplantation. A case occurring early after kidney transplantation is reported in a patient presenting with candiduria. Ultrasound examination detected several fungal bezoars, presenting as a proliferating, avascular lesions, located within the ureter and the bladder. It allowed to demonstrate the rapid extension of lesions, in spite of a medical treatment, leading to a successful endoscopic removal of fungus balls.

Aged↗
PubMed2000

[Quid?].

Explore the source record for details and available documents.

Adult↗
PubMed2000

[Upper urinary tract MRI].

New MRI modalities today available allow exploration of many kidney diseases. Main developments have been made in the diagnosis of small tumors and tumoral extension of huge masses. The other important way of application is MR urography which perfectly show the dilated urinary tract in few seconds. Their potential application are for renal insufficiency, allergic reaction to iodine contrast media and in cases of contra indication to ionised radiations. It is a complementary sequence to assess the urinary tract in pelvic exploration. The evaluation of kidney function will be possible in the near future.

Contraindications↗
PubMed1999

Enhanced protective response and immuno-adjuvant effects of porcine GM-CSF on DNA vaccination of pigs against Aujeszky's disease virus.

This study was conducted to investigate whether the co-delivery of DNA encoding porcine cytokines would enhance a protective immune response in pigs to a Pseudorabies virus (PRV; or Aujeszky's disease virus) DNA vaccine. Aujeszky's disease in pigs results in respiratory and nervous symptoms with important economic losses. To evaluate cytokine effects, eukaryotic expression vectors were constructed for porcine GM-CSF, IL-2 and IFN-gamma. cDNA for each of these cytokines was inserted under the control of a CMV promoter in the pcDNA3 plasmid and cytokine expression was confirmed after DNA transfection in various mammalian cell cultures by bioassays (GM-CSF and IL2) and ELISA (IFN-gamma). Pigs were vaccinated by single intramuscular injection with plasmid DNA encoding PRV gB and gD along with various combinations of cytokine plasmid constructs. Pig serum was tested for the production of antibody by isotype specific anti-PRV ELISA. Pigs were then challenged with the highly virulent PRV strain NIA3 on day 21 after vaccination. The survival and growth rate of pigs were monitored for seven days after the viral challenge. The co-administration of GM-CSF plasmid increased the immune response induced by gB and gD PRV DNA vaccine. This immune response was characterized by an earlier appearance of anti-PRV IgG2, a significantly enhanced anti-PRV IgG1 and IgG2 antibody response, a significantly decreased and shortened viral excretion in nasal swabs and an improved protection to the viral challenge. In contrast, the co-administration of porcine IL-2 or IFN-gamma had no adjuvant effects. Our results thus demonstrate for the first time that the application of porcine GM-CSF gene in a DNA vaccine formulation can exert immuno-adjuvant and protective effects with single vaccination in the natural host pig against Aujeszky's disease.

Adjuvants, Immunologic↗
PubMed1999

[Computed tomography study of the sigmoid colon: discriminating diagnostic criteria and interobserver correlations].

PURPOSE: To assess the value of pericolonic findings at CT in the evaluation of the sigmoid colon. MATERIALS AND METHODS: A total of 210 CT examinations were retrospectively reviewed by 3 blinded radiologists. Data was analyzed to determine the interobserver correlation and the value of pericolonic and colonic wall findings in diagnosis of sigmoid colon pathology. RESULTS: The interobserver correlation for pericolonic findings was equal to or superior to that for colonic wall findings. The presence of abnormal pericolonic fat was the most sensitive (88%) and specific (93%) sign to differentiate a diseased sigmoid colon from a normal one or from sigmoid diverticulosis. Wall-thickening was less sensitive (82%) and specific (76%). Findings suggesting malignancy over diverticulitis included acute zone of transition, focal fatty infiltration, and lymph nodes. Symmetrical and circumferential wall thickening, target-like enhancement, and local fatty proliferation were findings suggesting colitis over diverticulitis. Wall thickening more than 15 mm, involvement of 15 cm or less, asymmetrical involvement, acute zone of transition, and homogeneous or heterogeneous enhancement were findings suggesting malignancy over colitis. CONCLUSION: To render a diagnosis, the evaluation of the fat infiltration must prevail on the parietal thickening appreciation.

Adipose Tissue↗
PubMed1999

[Marijuana, health, disease, and freedom: analysis of an Internet forum].

This paper takes a Health Education perspective to analyze a debate forum on the Brazilian Internet site entitled "Universo On-Line", in which the following questions were addressed: "Do you believe that marijuana is harmful to one's health?" "In your opinion, should marijuana use be decriminalized?" By applying qualitative discourse analysis techniques to responses from the forum, we were able to identify six main types of discourse, reflecting the opinions of six "collective subjects" concerning drugs, health, disease, and freedom and existing as social representations in the current Brazilian collective imagination. Research on these social representations allows one to establish criteria for intervention in the field of Health Education.

Alcoholism↗
PubMed1998

Decreased number of nucleolar organizing regions in collagen lattice cultured fibroblasts.

Dermal fibroblasts cultivated in tridimensional matrices (lattices) of collagen exhibit a very low metabolic activity, and a low protein synthesis in particular. We have previously shown that ribosomal RNA content and half-life were decreased in collagen lattice cultured fibroblasts when compared to monolayer cultured fibroblasts. In this study, we seeded fibroblasts in collagen lattices and investigated the influence of matrix on the number of nucleolar organizing regions. We found that fibroblasts in fully retracted lattices exhibited a significant decrease of 45% (P < 0.001) in the number of nucleolar organizing regions when compared to monolayer cultured fibroblasts. This decrease was correlated to the decrease in ribosomal RNA content. These data suggest that extracellular matrix induces early alterations of synthesis and/or processing of ribosomal RNAs, explaining, at least partly, the resulting low metabolic activity.

Adult↗
PubMed1998

Intrauterine infusion of high doses of pig trophoblast interferons has no antiluteolytic effect in cyclic gilts.

In the pig species, the preimplanting trophoblast is known to synthesize and secrete high amounts of interferon during early development. Previous experiments in cyclic gilts using total conceptus secretory proteins suggested that porcine trophoblastic interferons, unlike those of ruminants, exert no effect on the luteal cycle. In the present experiment, cyclic Meishan gilts were divided into two groups, cannulated on both uterine horns, and given daily injections of either a placebo or increasing doses of a mixture of recombinant interferon-gamma and interferon-delta, on Days 11-14 of the estrous cycle. In treated gilts, the injected doses were much higher than those previously found in uterine perfusates from pregnant gilts. However, no significant differences could be found between the control (n = 4) and the treated (n = 5) group concerning the days of the estrous cycle for mid-decrease of progesterone (control: Day 14.5+/-0.57 [mean+/-SD]; treated: Day 15+/-1.25), the day of estrus (control: Day 19+/-0.96; treated: Day 19.6+/-0.55), and the subsequent ovulation rate (control: 14+/-2.2 corpora lutea; treated: 13.1+/-1.1 corpora lutea). These data confirm that pig trophoblastic interferons, unlike those of ruminants, do not themselves exert an antiluteolytic effect. A possible synergistic effect of embryonic estrogens on the luteal functions of nonpregnant sows remains to be determined.

Animals↗
PubMed1998

Long-term variability of serum lipoprotein(a) concentrations in healthy fertile women.

Lipoprotein(a) is a unique lipoprotein with atherothrombogenic properties. Although its blood concentration is mainly genetically determined, various factors exist which may cause variability. These may influence the clinical use of the results. We studied lipoprotein(a) biological variation by a rate nephelometric assay over a period of two years in a population of healthy fertile women. The study was performed in 12 volunteers, healthy subjects with various lipoprotein(a) concentrations, by monthly determinations during one year and a single determination one year later, together with measurements of total, high density lipoprotein and high density lipoprotein2 cholesterol, triglycerides and apolipoproteins A1 and B. The intra-individual variability of lipoprotein(a) ranged between 4 to 20%, with three subjects showing a coefficient of biological variation higher than 15%. In absolute terms, the difference between two determinations could represent 0.44 g/l or 50% of the mean value. This study suggests that physiological lipoprotein(a) variations should be taken into account for clinical purposes, especially in patients in need of thorough risk evaluation.

Adult↗
PubMed1998

[Single shot fast spin echo sequence MRI cholangiopancreatography].

PURPOSE: To assess the value of single shot fast spin echo MR sequence (SS-FSE) in the morphological analysis of the biliary tree and pancreatic ducts and to compare its accuracy with other imaging methods. MATERIAL AND METHODS: 95 consecutive patients referred for clinical and/or biological suspicion of biliary obstruction were explored with MR cholangiopancreatography (MRCP). All patients were explored with a Signa 1.5 T GE MR unit, with High Gradient Field Strength and Torso Phased Array Coil. Biliary ducts were explored with SS-FSE sequence, coronal and oblique coronal 20 mm thick slices on a 256 x 256 matrix. Total acquisition time was 1 second. Native pictures were reviewed by two radiologists blinded to clinical information. In case of disagreement, a third radiologist's judgement was requested. In 88 cases, MRCP results were compared with direct biligraphy methods. RESULTS: In all cases, MRCP produced high quality images without MIP or other post-processing methods. For detection of biliary tree distensions, the concordance value of MRCP was over 91% (Kappa 0.82). For detection of biliary tree and/or pancreatic duct obstruction, MR sensitivity was 100% and specificity 91%. The overall diagnostic concordance value of MRCP was > or = 93%. Difficulties in MRCP were caused by functional diseases or benign stenosis. MRCP accurately diagnosed all lithiasic obstructions starting from a stone size of 3 mm. CONCLUSION: MRCP produces fastly high-quality images. As it is totally safe, it can be proposed as a first intention method in biliopancreatic duct explorations.

Adolescent↗
PubMed1997

Alanine-stretch scanning mutagenesis: a simple and efficient method to probe protein structure and function.

We have developed a foolproof method to substitute a stretch of residues by alanines. After the introduction of aPstI site by IPCR, thus creating two alanine codons, additional codons are introduced at this site through the use of an 'alanine-stretch cartridge'. These cartridges comprise an antibiotic resistance gene flanked on both sides by alanine codons. Excision of the resistance gene byPvuII then yields the correct insertion of codons. The method is both highly reliable and flexible and should be of general use.

Alanine↗
PubMed1997

Topographical and functional investigation of Escherichia coli penicillin-binding protein 1b by alanine stretch scanning mutagenesis.

Penicillin-binding proteins (PBPs) are the targets of beta-lactam antibiotics. We have used a systematic five-alanine substitution method (called ASS [alanine stretch scanning] mutagenesis) to investigate the functional or structural role of various stretches of amino acids in the PBP1b of Escherichia coli. To probe the specific activity of each variant, the antibiotic discs assay was used with strain QCB1 (delta ponB) in the presence of cefaloridine, which totally inhibits the complementing action of PBP1a. This in vivo test has been combined with a quick and efficient in vitro test of the penicillin-binding activity of each of these variants with fluorescent penicillin. This approach has enabled us to show an unexpected role of the N-terminal and C-terminal tails of PBP1b. Moreover, we have established the correct position in PBP1b of the SMN motif that, with the SXXK and the KTG motifs, constitutes the signature of the penicilloyl serine transferases family. Finally, we have shown that the transglycosylase and the transpeptidase domains are separated by an inert linker region, where substitutions and insertions can be made without hindering the in vivo and in vitro activity of the protein.

Alanine↗