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Biomedical subjects

C Bonneau

Publications and source records attributed to C Bonneau.

At least 19 recordsLinked to original sources
PubMed2005

[Can US-guided vacuum-assisted biopsies be an alternative to diagnostic surgery in cases of non-diagnostic core needle biopsy?].

PURPOSE: To assess US-guided vacuum-assisted biopsies in the diagnosis of suspicious sonographic breast lesions after non-diagnostic core needle biopsies (CNB). PATIENTS AND METHODS: Retrospective study of 42 females with suspicious breast lesions at US. CNB previously performed were non-diagnostic. Because of the larger sample size, vacuum-assisted biopsies were performed, instead of surgical biopsy. RESULTS: Vacuum-assisted biopsies showed 32 benign lesions. Histologic examination of the CNB showed non-specific fibrous tissue in 43% of cases as opposed to 7.1% for vacuum-assisted biopsies. The latter provided a more specific diagnosis (mainly fibrocystic breast disease). From a total of 4 lesions that were suspicious at CNB, 3 were diagnosed as malignancies after vacuum-assisted biopsy and one case was a "borderline" lesion. Three additional malignant and three additional borderline lesions were diagnosed on vacuum-assisted biopsies. In 11 cases, surgical excision was performed, and all diagnoses from vacuum-assisted biopsies were confirmed at microscopy, except in one case where it was underestimated (ADH versus DCIS). CONCLUSION: US-guided vacuum-assisted biopsy is a reliable technique. Because it provides more tissue than CNB, it can be an alternative to diagnostic surgery after non-diagnostic CNB. Indeed, it allows confirmation of the diagnosis and provides a more specific diagnosis of benign lesions. With regards to malignant and borderline lesions, it avoids the risk of false-negative CNB and overlooking carcinomas.

Adult↗
PubMed2003

[Value of ultrasound detection of post-Mammotome scar for preoperative localization of breast microcalcifications].

PURPOSE: We attempted to find ultrasound scar subsequent to vacuum assisted breast biopsy (Mammotome system) previously performed, and to enhance its value for preoperative localization. MATERIALS AND METHODS: Our study included 34 females requiring needle localization prior to surgery. They previously had Mammotome core biopsies for clustered microcalcifications. US examination was systematically performed before insertion of the metallic marker, in order to detect a scar. Identification of the scar allowed ultrasonographic guided localization. The accuracy was correlated with histologic findings. RESULTS: Ultrasonography detected a scar in 21 of the 34 patients (63%). Among all these cases, a perfect correlation could be established between ultrasound target and histologic scar revealed by microscopic examination. CONCLUSION: Ultrasound detection of scar allows ultrasonographic guidance and can therefore be the only alternative in cases of absence or displacement of the marker clip.

Adult↗
PubMed2001

[Post-vaccination granuloma due to aluminium hydroxide].

Post-vaccination granulomas a well-known reaction due to aluminium adsorbed vaccines. We report three cases of children who developed subcutaneous nodules at the site of a previous injection of Tetracoq*vaccine (tetanus, diphtheria, Bordetella pertussis, poliovirus). Histologically, the lesions were characterized by a necrotizing granulomatous reaction with eosinophilic crystalline material. This material stained positively with the solochrome cyanine stain and was pink-purple. This aluminium stain enabled diagnosis of post-immunization injection-site reaction due to aluminium.

Aluminum Hydroxide↗
PubMed1998

Expression of the rice yellow mottle virus P1 protein in vitro and in vivo and its involvement in virus spread.

Rice yellow mottle sobemovirus (RYMV) is responsible for the yellow mottle disease on rice in Africa. The expression and function of the protein P1 (17.8 kDa) encoded by the first open reading frame (ORF) of RYMV was investigated. Using an antibody raised against purified P1, two proteins with apparent molecular masses of 18 and 19 kDa were identified in in vitro translation reactions of transcripts of the full-length cDNA of RYMV. Likewise, gene products with similar molecular mass were detected in inoculated and systemically infected rice leaves and in infected rice protoplasts. A mutant from which ORF1 nucleotides 88 to 547 were deleted and a frameshift mutant that resulted in truncation of 83 amino acids from the C terminus of P1 were incapable of replicating in protoplasts. In contrast, a mutant that does not express P1 due to a mutation at the initiation codon replicated efficiently in protoplasts but at a reduced level (about 0.5- to 2-fold less) compared to replication of wild-type RNA. None of these mutants caused systemic infection in rice plants. Transgenic rice plants that express P1 complemented the initiation codon mutant, but not the deletion mutants, and produced systemic infection. These experiments demonstrate that P1 of RYMV is dispensible for virus replication, although nucleotide deletions or additions in ORF1 are apparently lethal for virus replication. Furthermore, P1 of RYMV is required for the infection of plants and is important for virus spread.

Animals↗
PubMed1998

Movement of rice yellow mottle virus between xylem cells through pit membranes.

The translocation of rice yellow mottle virus (RYMV) within tissues of inoculated and systemically infected Oryza sativa L. leaves was characterized by Western immunoblotting, Northern blotting, and electron microscopy of thin sections. In inoculated leaves, RYMV RNA and coat protein first were detected at 3 and 5 days postinoculation, respectively. By 6 days postinoculation, RYMV had spread systemically to leaves, and virus particles were observed in most cell types, including epidermal, mesophyll, bundle sheath, and vascular parenchyma cells. Most of the virions accumulated in large crystalline patches in xylem parenchyma cells and sieve elements. Colocalization of a cell wall marker for cellulosic beta-(1-4)-D-glucans and anti-RYMV antibodies over vessel pit membranes suggests a pathway for virus migration between vessels. We propose that the partial digestion of pit membranes resulting from programmed cell death may permit virus migration through them, concomitant with autolysis. In addition, displacement of the Ca2+ from pit membranes to virus particles may contribute to the disruption of the pit membranes and facilitate systemic virus transport.

Biological Transport↗
PubMed1997

Effects of plasma lipoproteins on the production of superoxide anion by human polymorphonuclear leukocytes in vitro.

Polymorphonuclear leukocytes (PMN) generate highly reactive oxygen derived free radicals that may cause lipoprotein lipid oxidation and so contribute to the pathogenesis of atherosclerosis. On the other hand it has been shown that lipoproteins can alter cell functions in vitro. We therefore studied the effects of atherogenic lipoproteins, VLDL and LDL, on the production of superoxide anion by human PMN in the presence or absence of formyl-methionyl-leucyl-phenylalanine (fMLP). VLDL and LDL stimulate PMN superoxide production and potentialize PMN stimulation by fMLP. The lipid moiety of the lipoproteins might be mainly involved in these effects. The binding of radio-labelled fMLP to its specific membrane receptor was significantly enhanced in the presence of VLDL and only slightly in the presence of LDL. The study of the signal transduction suggests that modulation of phospholipase D and A2 activities could be involved in the modification by LDL of PMN response to fMLP.

Arteriosclerosis↗
PubMed1997

Effects of human low-density lipoproteins on superoxide production by formyl-methionyl-leucyl-phenylalanine activated polymorphonuclear leukocytes.

Neutrophils play a major role in the host defence by producing reactive oxygen species. These products are liberated by activated cells and are known to cause endothelial cell injury and damage. The present study shows that low-density lipoproteins increase superoxide anion production by twofold in polymorphonuclear leukocytes stimulated by formyl-Met-Leu-Phe in vitro. Moreover, LDL induced a large increase in phosphoinositides and cytosolic-free calcium. Data from experiments performed on neutrophils treated with pertussis toxin, staurosporine, propranolol or niflumic acid suggest that modulation of phospholipase D and A2 activities could be involved in the modification by LDL of leukocyte response to formyl-Met-Leu-Phe. LDL lipid moiety could play a key role in their action on polymorphonuclear functions because cholesterol was exchanged between lipoproteins and cells that can modify membrane fluidity and interact with the formyl-Met-Leu-Phe receptor.

Adrenergic beta-Antagonists↗
PubMed1997

Non-reflex mediated changes in plantarflexor muscles early after stroke.

The aims of this study were to determine whether changes in the non-reflex component of spastic plantarflexors had developed 2 and 4 months after stroke and to study their relationship with the level of impairment. One group of adults with hemiparesis (HPs) was tested 2 and 4 months after the onset of stroke, and data were compared with a control group (CTLs) tested once. Twenty-two patients (14 males) admitted over a 4-month period in a rehabilitation centre (mean = 62 yrs +/- 14), and 11 (6 males) non-disabled (CTLs) subjects (mean = 57yrs +/- 12.8) agreed to participate in the study. The resistive torque (RT) recorded with a myometer during slow (8-10 degrees/s) passive dorsiflexions imposed manually served as the primary outcome, whereas, the Ashworth score (spasticity), ankle ROM and Fugl-Meyer motor subscore were used as secondary measures to determine the level of impairment. The mean RT values measured at 0 degrees dorsiflexion on the affected and unaffected sides were compared with those in CTLs. As expected, the RT values 2 and 4 months post-stroke on the unaffected side did not differ from corresponding values in CTLs. Significantly higher RT values on the affected side when compared to the unaffected side were found both at 2 months (39%; p < 0.05) and at 4 months (43%; p < 0.01). No significant difference existed on the affected side between the 2nd and 4th months. A high (r = 0.80) and significant (p < 0.0001) correlation coefficient was calculated between the changes in RT values recorded at 2 and 4 months. Low and not significant correlations were computed between these RT changes and factors such as the ROM (r = -0.24), the Ashworth score (r = 0.23) and the Fugl-Meyer lower extremity motor subscore (r = -0.26). Present results indicate that: (1) changes in the non-reflex component are already present 2 months after stroke but do not increase significantly between the 2nd and 4th months; (2) these changes are not related to the level of impairment; and (3) myometry testing at 2 months could be used as a preventive measure to detect patients more at risk of developing severe passive muscle stiffness.

Biomechanical Phenomena↗
PubMed1996

Determination of plasma protein-bound malondialdehyde by derivative spectrophotometry.

We describe a method for the measurement of protein-bound malondialdehyde with the thiobarbituric acid reaction in human plasma using second-derivative spectrophotometry. Calibration was done by spectrum height measurement from the baseline at 532 nm. The data were compared with those obtained by using conventional absorbance and fluorimetric measurements. The results were linear from 0.2 to 80 mumol/l and the detection limit was 0.19 mumol/l. Within-run and between-run precision, evaluated by analysing pooled normal plasma, were 8 and 14% respectively. The method was tested for the influence of bilirubin, haemoglobin, glucose, urea, uric acid, sucrose and N-acetyl-neuraminic acid which interfered in the colorimetric method but not in the technique proposed here. The mean (+/-SD) malondialdehyde concentration determined in 59 healthy blood donors with the new assay was 0.34 (+/-0.14) mumol/l. This assay procedure could represent an alternative to high-performance liquid chromatography for the measurement of malondialdehyde in biological media.

Blood Proteins↗
PubMed1995

[Respiratory allergies among bakers and pastry cooks: epidemiologic survey done in 1991 by the occupational physicians of the Loire-Atlantique].

The aim was to study the prevalence of respiratory allergy (rhinitis and asthma) in a population of bakers and pastrycooks. In 1991, 485 bakers and pastry cooks were examined by 27 work-physicians of Loire-Atlantic. The investigation was composed of a standardised questionnaire (signs of respiratory function, atopic history, smoking of tobacco ...), a clinical examination, and tests of respiratory function. An allergy assessment was made of all subjects with symptoms. 14.4% of subjects had rhinitis and 6.4% asthma. Development of these pathologies was clearly job-related for 2/3 of those with rhinitis and more than half of the asthmatics (55%). Occupational rhinitis and asthma were significantly more frequent in bakers than in pastrycooks and were linked to atopic history. Occupational asthma was associated with length of exposure to flour and with occupational rhinitis. In conclusion, these findings are comparable with or a little less than those that have been reported in occupational literature. They under-estimate the importance of the problem because of the occupational selection effect that is associated with these pathologies. Rhinitis and asthma are 1.5 to 3 time more common in bakers than in pastrycooks.

Adult↗
PubMed1995

[Respiratory allergies among symptomatic bakers and pastry cooks: initial results of a prevalence study].

A survey was carried out on respiratory symptoms and skin prick response to common allergens, storage mite and occupational allergens. Among 178 symptomatics bakers and pastry workers from small businesses in western France, only 65 people underwent skin prick and specific-IgE. 12 (18%) workers were skin positive to at least one common or occupational allergens. The more often skin positive were D. Ptero. mite 36 (57%); Alpha amylase 23 (35%); wheat flour 17 (26%); saccharomyces cerevisiae 16 (25%); Ephestia 15 (24%). The sensitivity of skin test was better than specific IgE for D. Ptero. Mite 36 (57%); and Alpha amylase 23 (35%). The sensitivity of specific IgE was better than skin test for wheat flour 26 (45%) and rye flour 23 (40%). Occurrence of skin positive to occupational allergen among symptomatics with rhinitis and asthma is much more frequent in workers with skin positive to common allergens (40/36) than in workers with skin negative (8/20). Atopy must be regarded as an important predisposing factor for skin sensitisation to occupational allergens. We conclude in the necessity of a standardised allergologic exploration to be done in symptomatics bakers.

Allergens↗
PubMed1994

Evaluating motor recovery early after stroke: comparison of the Fugl-Meyer Assessment and the Motor Assessment Scale.

This study compared the measurements of the Motor Assessment Scale (MAS) to that of the Fugl-Meyer Assessment (FMA), a reliable and valid test for motor function in stroke patients. Thirty-two patients (20 men, 12 women) with a mean age of 60 years, and a mean time since stroke of 64.5 days, were tested with the FMA and MAS on two consecutive days. The Spearman correlation coefficient for total FMA and total MAS scores was 0.96. For selected items, significant (p < 0.001) correlations ranged from 0.65 to 0.93, except for sitting balance (-0.10). Low negative correlations between sitting balance scores and other items (motor and sensation) were found only for the FMA test, suggesting that the FMA sitting balance test is not valid for measuring balance and is likely responsible for the low correlation. Comparison of scores (normalized in percent of maximal value) for corresponding items of the two instruments also indicated that the FMA measured a higher (Wilcoxon = p < 0.0001) level of motor recovery, (especially in more disabled patients), for both the upper (15.7%) and lower extremities (27.5%). Lastly, a cumulative frequency distribution analysis indicated that a larger proportion of patients was found in the lower class interval scores of the MAS in comparison to the FMA. These results (1) support the concurrent validity of the MAS for measuring motor recovery in acute stroke patients; (2) demonstrate the poor validity of the FMA sitting balance test, and (3) suggest that the FMA scale can better discriminate the level of motor recovery than the MAS in the early stage of recovery or in the more disabled subjects.

Adult↗
PubMed1994

Effects of low-density lipoproteins on polymorphonuclear leukocyte functions in vitro.

In the circulation, human polymorphonuclear leukocytes (PMN) are exposed to various factors, such as lipoproteins, which could alter their metabolic and functional characteristics. In this work, the effects of low-density lipoproteins (LDL) on PMN oxidative metabolism and migration were studied in vitro. LDL stimulated PMN superoxide generation. This effect lasted for 15-20 min and was concentration-dependent. Staurosporine, a potent inhibitor of protein kinase C, did not suppress this stimulating effect. The chemotactic response of PMN to formyl-methionyl-leucyl-phenylalanine and C5a was inhibited by LDL and this effect was conserved after trypsination of LDL. LDL from normolipidemic subjects were more potent than LDL from hypertriglyceridemic subjects for both effects. LDL had no effect on superoxide generation by opsonized zymosan-stimulated PMN. These data showed that PMN responses may be modified by environmental conditions such as the presence of lipoproteins.

Alkaloids↗
PubMed1991

In vitro modulating effect of human very-low-density lipoproteins on human polymorphonuclear leukocyte oxidative metabolism and migration.

In this work, the in vitro effects of very-low-density lipoproteins (VLDL) on human polymorphonuclear leukocyte (PMN) oxidative metabolism and migration were studied. VLDL stimulated PMN superoxide generation in absence of other stimulating agents. The effect of VLDL from normotriglyceridemic subjects was more marked than with VLDL from hypertriglyceridemic subjects. VLDL reduced in a dose-dependent manner the luminol-dependent chemiluminescence of PMN stimulated by phorbol myristate acetate (PMA) and, to a lesser degree, by opsonized zymosan. This effect was observed with VLDL concentrations found in healthy and hypertriglyceridemic patients. Superoxide anion generation was also reduced by preincubation of PMN with VLDL before stimulation with PMA but not opsonized zymosan. VLDL were not cytotoxic for PMN. The above effects appear to be an intrinsic property of VLDL and might lead to reduced PMN-mediated non-specific host defences in hypertriglyceridemic subjects.

Cell Movement↗