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Biomedical subjects

S Aubert

Publications and source records attributed to S Aubert.

At least 19 recordsLinked to original sources
PubMed2006

Post-traumatic fibro-osseous lesion of the ribs: a relatively under-recognised entity.

AIM: To report the description of a rare benign osseous lesion affecting the ribs entitled post-traumatic fibro-osseous lesion (PTFOL). METHODS: Seven cases of PTFOLs were retrieved from the archives of the University Hospital of Lille. Histological slides were reviewed and lesions were classified according to the histological patterns described by McDermott et al. Clinical and follow-up data were obtained from the patients' charts. RESULTS: PTFOLs occurred principally in men (mean age 31.8 years) with a known or suspected previous chest injury for four of them. No previous cancer was noted. Radiologically, PTFOLs readily presented as an isolated expansive lucency with a sclerotic rim located on the last five ribs. A constant increased uptake of radionucleotide was noted on bone scan. Microscopically, two fibro-osseous, four xanthomatous and one mixed pattern were individualised. Lesions were characterised by a network of anastomosing bone trabeculae without osteoblast lining within a fibrous stroma. A zonal maturation from woven to peripheral lamellar bone was characterised. Central sheets of lipid-laden histiocytes were conspicuous in the xanthomatous type. For each patient, clinical follow-up was excellent, without any recurrence. CONCLUSIONS: This is the second largest series of PTFOLs, which is considered to be a dysplastic healing process after trauma. It may be symptomatic or shown by imaging studies realised for unrelated reason. PTFOL is regularly misdiagnosed with other more common lesions of the ribs, such as fibro-osseous dysplasia, osteoma osteoid and benign fibrous histiocytoma. Its recognition is of importance because no follow-up is needed after resection.

Adolescent↗
PubMed2006

[Results of video-assisted mitral surgery in a non-selected population].

A prospective 'analysis of operative risk and results in video-assisted mitral valve surgery performed in a non selected population is reported. Seventy two consecutive patients (1997-2004) with mean age 60 +/- 12 years underwent a video-assisted mitral valve procedure using a femoral CPB. A transthoracic direct aortic clamping was done in 28 patients (TT) and an endo-aortic occlusion balloon was used in 44 patients (Endo). The surgical approach was a right lateral minithoracotomy in all cases; 16 patients had a previous cardiac surgery. The expected mitral operation (39 repairs, 33 replacements) was done in all cases, without conversion. There were 4 early deaths (1 st month), all in Endo group: 1 aortic dissection, 1 heart failure and 2 sudden deaths. Postoperative complication occurred in 17 patients with 5 reoperations for hemostasis of the thoracic wall. Cumulative rate of mortality and morbidity was 29% in Endo and 28% in TT (ns). Hospital stay was 8 +/- 2 days. At discharge, 4 patients had a residual grade 2 echocardiographic mitral regurgitation after valve repair. In January 2005, with a 1.8 years follow-up, there were 4 late deaths, 3 patients underwent a valve reoperation, 2 patients were still in NYHA class 3 and 5 patients had a residual grade 1 or 2 mitral regurgitation. The 3-year actuarial survival was 86 +/- 10% and the 3-year probability to be free of reoperation was 95 +/- 6%. In mitral valve surgery, video-assisted approach is reliable, the operative risk is controlled and midterm results are not compromised. Video-assisted mitral valve surgery is a new less invasive standard; it is the procedure of choice in valve replacement, in reoperation and in non complex valve repair with good cosmetic results.

Cardiopulmonary Bypass↗
PubMed2005

[Evolution of the Fontan operation and results in patients with single ventricles or mixed congenital malformations].

STUDY OBJECTIVES: To examine the results of right heart derivations and clinical outcomes according to preoperative characteristics and operative strategy implemented. METHODS: Fontan operations were performed in 65 patients (mean age = 10.3 years, 41 males). The majority of cardiopathies were single ventricles (SV) with (49% of patients) or without (26%) tricuspid atresia. A palliative bidirectional cavo-pulmonary (BCP) anastomosis was performed prior to Fontan in 15 patients. Intra-atrial Fontan tunnelling was performed in 43 patients, Kreutzer-type operations in 10, and extracardiac tubes were used in 8 patients. The mean duration of follow-up was 6.1 +/- 0.3 years. RESULT: The 30-day mortality was 13.8%. Early mortality was higher among patients with SV with than without tricuspid atresia (P < 0.01), and among patients < 4 years old. Early reoperations were required in 5 patients, including dismounting in 1, BCP anastomosis after Kreutzer procedure in 1, and tube thrombosis in 1 patient. A single death occurred past 30 days, and late adverse events included protein-losing enteropathy in 1 patient, complete atrioventricular block in 1, and tube thrombosis treated with heparin in 2 patients. At the end of follow-up, 75% were in New York Heart Association functional class I. CONCLUSION: Our intermediate-term results of Fontan-type operations were satisfactory, and steadily improving. The prognosis was better in patients operated at age 4 or older. A prior BCP anastomosis improved the results. A higher morbidity was observed with intra- than with extra-atrial Fontan procedures. The merit of fenestration procedures with respect to morbidity remains the be evaluated.

Adolescent↗
PubMed2004

Methyl-beta-D-glucopyranoside in higher plants: accumulation and intracellular localization in Geum montanum L. leaves and in model systems studied by 13C nuclear magnetic resonance.

Using (13)C-NMR, methyl-beta-D-glucopyranoside (MeG) was characterized as a major compound in the leaves of the alpine herb Geum montanum L. MeG continuously accumulated during the life span of G. montanum leaves, and accounted for up to 20% of the soluble carbohydrates in aged overwintering leaves, without being reallocated during senescence. Incubating intact plant tissues, culture cells, and purified organelles with (13)C-labelled substrates showed that MeG was synthesized in the cytosol of cells, directly from glucose and methanol molecules. There was no contribution of the C-1 pathway. MeG was subsequently stored in the vacuole without being re-exported to the cytoplasm. All the dicots tested contained the enzymatic machinery permitting MeG synthesis from methanol and glucose, but the plants accumulating this compound at concentrations higher than 1 micromol g(-1) wet wt were mainly members of the Rosaceae family belonging to the Rosoideae subfamily. It is suggested that the synthesis of MeG may contribute to reduce the accumulation in the cytoplasm of methanol and its derived compounds.

Aging↗
PubMed2004

[Non verbal communication abilities in severe traumatic brain injury].

OBJECTIVE: Discursive abilities of severe brain injured patient are always impaired: loss of flexibility, lack of cohesion and coherence, often more elliptic. We know few about nonverbal competencies during discourse. The objective is to verify nonverbal abilities of these patients by pragmatic analysis. METHODS: Four men were examined more than 7 years after severe traumatic brain injury. Nonverbal Prutting and Kirchner Pragmatic Protocol (1987) were done allowing to a qualitative and quantitative measurement of paralinguistic behaviour: prosody and quality of speech, facial expression, posture, gaze, gesture. Two conditions were recorded: dual (descriptive discourse) and group (conversational discourse). Associated impairments such as cognitive and dysexecutive functioning were also investigated. RESULTS/DISCUSSION: Impoverishment (loss of ability) or impaired inadequacity was observed in all patients. Paralinguistic competences of conversational discourse was worse than descriptive one. Facial expression, gaze functioning, referential gesture were more often impaired. Maladjustment could be interpretated in reference with dysexecutive syndrome. CONCLUSION: In spite of the lack of information about the range of normal pragmatic behaviour, it seems that brain injured patients have shown poor nonverbal abilities during discourse. Rehabilitation training of communication skills would integrate this fact in order to improve interactivity and social relationship.

Adult↗
PubMed2004

Low-grade tubular myxoid renal tumors: a clinicopathological study of 3 cases.

We report 3 cases of a new renal cell tumor entity with a review of the literature. These 3 cases were retrieved from the files of this institution from 1991 to 2002. The clinical data and all histologic slides were reviewed and an immunohistochemical study was performed. Patients were all females. Tumors were almost similar with well-defined margins. Tumor architecture was tubular and focally fusiform with an abundant myxoid stroma. Tumor cells were low cuboidal, slightly eosinophilic with low nuclear grade. Immunohistochemistry was in favor of a distal nephron differentiation. All patients were healthy after surgery. We describe 3 cases of a new clinicopathological entity entitled low-grade tubular myxoid renal tumor with a benign clinical course.

Adult↗
PubMed2003

[Localized amyloidosis of the cavum].

INTRODUCTION: Amyloidosis is characterized by extracellular deposits of proteins. OBSERVATION: A 66 year-old patient presented with a pseudo-tumoral amyloidosis of the cavum. Clinical and biological examinations confirmed the localized aspect of the disease and immunohistochemical exploration identified a type AL amyloidosis. COMMENTS: The disease may be diffuse involving many organs and leading to various clinical manifestations. It can also be localized and take on a pseudo-tumoral aspect. Localised amyloidosis is a rare lesion of the upper aero-digestive tract, predominating in the larynx. Nasopharyngeal involvement is exceptional.

Aged↗
PubMed2003

[Primary leiomyosarcoma of pulmonary artery: a rare tumor mis-diagnosed as pulmonary embolism].

INTRODUCTION: Primary leiomyosarcoma of the pulmonary artery is an extremely rare tumor that is frequently misdiagnosed as chronic pulmonary embolism. EXEGESIS: We describe a new case and discuss diagnosis criteria, especially thanks to modern imaging techniques. A sarcomatous disease should be ruled out, if obliteration progress or is stable, on serial RMI or CT scans images, despite effective anti-coagulation treatment. CONCLUSION: An early identification and aggressive medical and surgical intervention has the potential for long-term survival.

Diagnosis, Differential↗
PubMed2003

Apertureless scanning near-field optical microscopy for ion exchange channel waveguide characterization.

We report the characterization of an integrated Ag+/Na+ ion exchange waveguide realized in a silicate glass substrate using apertureless scanning near-field optical microscopy. Our experimental set-up is based on the combination of a commercial atomic force microscope with an optical confocal detection system. Thanks to this system, the topography and evanescent optical field at the waveguide top surface are mapped simultaneously. Also, the process of apertureless scanning near-field optical microscopy image formation is analysed. In particular, fringe patterns appearing in the image reveal the intrinsic interferometric nature of the collected signal, due to interference between the field scattered by the tip end and background fields related to guide losses. We give a quantitative interpretation of these fringes. Evanescent intensity mapping on the sample surface allowed us to extract physical waveguide parameters. In particular, it shows an unambiguous multimode beat along the waveguide propagation axis. Furthermore, we show that analysis of this intensity profile reveals back-reflection effects from the waveguide exit facet. The resulting standing waves pattern allows us to evaluate the eigenmode propagation constants.

Equipment Design↗
PubMed2003

Reversibility of cold- and light-stress tolerance and accompanying changes of metabolite and antioxidant levels in the two high mountain plant species Soldanella alpina and Ranunculus glacialis.

Two high mountain plants Soldanella alpina (L.) and Ranunculus glacialis (L.) were transferred from their natural environment to two different growth conditions (22 degrees C and 6 degrees C) at low elevation in order to investigate the possibility of de-acclimation to light and cold and the importance of antioxidants and metabolite levels. The results were compared with the lowland crop plant Pisum sativum (L.) as a control. Leaves of R. glacialis grown for 3 weeks at 22 degrees C were more sensitive to light-stress (defined as damage to photosynthesis, reduction of catalase activity (EC 1.11.1.6) and bleaching of chlorophyll) than leaves collected in high mountains or grown at 6 degrees C. Light-stress tolerance of S. alpina leaves was not markedly changed. Therefore, acclimation is reversible in R. glacialis leaves, but constitutive or long-lasting in S. alpina leaves. The different growth conditions induced significant changes in non-photochemical fluorescence quenching (qN) and the contents of antioxidants and xanthophyll cycle pigments. These changes did not correlate with light-stress tolerance, questioning their role for light- and cold-acclimation of both alpine species. However, ascorbate contents remained very high in leaves of S. alpina under all growth conditions (12-19% of total soluble carbon). In cold-acclimated leaves of R. glacialis, malate represented one of the most abundant compounds of total soluble carbon (22%). Malate contents declined significantly in de-acclimated leaves, suggesting a possible involvement of malate, or malate metabolism, in light-stress tolerance. Leaves of the lowland plant P. sativum were more sensitive to light-stress than the alpine species, and contained only low amounts of malate and ascorbate.

Acclimatization↗
PubMed2003

Minimal focus of adenocarcinoma on prostate biopsy: clinicopathological correlations.

AIMS: To establish the clinicopathological features of minimal volume prostate adenocarcinoma on prostate biopsy. METHODS: Twenty four cases of minimal adenocarcinoma diagnosed on prostate biopsy and treated by radical prostatectomy were reviewed. RESULTS: The major microscopic criteria were nuclear enlargement (22 of 24), infiltrative pattern (19 of 24), prominent nucleoli (19 of 24), intraluminal eosinophilic secretions (15 of 24), and high grade intraepithelial neoplasia associated (11 of 24). Sixteen of 24 cases were assigned a Gleason score 6 on biopsy. When the whole gland was assessed, 22 of these tumours were localised to the prostate (stage pT2), and only two cases were stage pT3. CONCLUSIONS: Minimal focus of adenocarcinoma on prostate biopsy is not an uncommon finding. It is usually an intermediate grade and localised stage neoplasm.

Adenocarcinoma↗
PubMed2001

Origin of the cytoplasmic pH changes during anaerobic stress in higher plant cells. Carbon-13 and phosphorous-31 nuclear magnetic resonance studies.

We tested the contribution of nucleoside triphosphate (NTP) hydrolysis, ethanol, and organic acid syntheses, and H(+)-pump ATPases activity in the acidosis of anoxic sycamore (Acer pseudoplatanus) plant cells. Culture cells were chosen to alter NTP pools and fermentation with specific nutrient media (phosphate [Pi]-deprived and adenine- or glycerol-supplied). In vivo (31)P- and (13)C-nuclear magnetic resonance (NMR) spectroscopy was utilized to noninvasively measure intracellular pHs, Pi, phosphomonoesters, nucleotides, lactate, and ethanol. Following the onset of anoxia, cytoplasmic (cyt) pH (7.5) decreased to 6.8 within 4 to 5 min, whereas vacuolar pH (5.7) and external pH (6.5) remained stable. The NTP pool simultaneously decreased from 210 to <20 nmol g(-1) cell wet weight, whereas nuceloside diphosphate, nucleoside monophosphate, and cyt pH increased correspondingly. The initial cytoplasmic acidification was at a minimum in Pi-deprived cells containing little NTP, and at a maximum in adenine-incubated cells showing the highest NTP concentration. Our data show that the release of H(+) ions accompanying the Pi-liberating hydrolysis of NTP was the principal cause of the initial cyt pH drop and that this cytoplasmic acidosis was not overcome by H(+) extrusion. After 15 min of anoxia, a partial cyt-pH recovery observed in cells supplied with Glc, but not with glycerol, was attributed to the H(+)-consuming ATP synthesis accompanying ethanolic fermentation. Following re-oxygenation, the cyt pH recovered its initial value (7.5) within 2 to 3 min, whereas external pH decreased abruptly. We suggest that the H(+)-pumping ATPase located in the plasma membrane was blocked in anoxia and quickly reactivated after re-oxygenation.

Acer↗
PubMed2001

Staphylococcus caprae strains carry determinants known to be involved in pathogenicity: a gene encoding an autolysin-binding fibronectin and the ica operon involved in biofilm formation.

The atlC gene (1,485 bp), encoding an autolysin which binds fibronectin, and the ica operon, involved in biofilm formation, were isolated from the chromosome of an infectious isolate of Staphylococcus caprae and sequenced. AtlC (155 kDa) is similar to the staphylococcal autolysins Atl, AtlE, Aas (48 to 72% amino acid identity) and contains a putative signal peptide of 29 amino acids and two enzymatic centers (N-acetylmuramoyl-L-alanine amidase and endo-beta-N-acetylglucosaminidase) interconnected by three imperfect fibronectin-binding repeats. The glycine-tryptophan (GW) motif found in the central and end part of each repeat may serve for cell surface anchoring of AtlC as they do in Listeria monocytogenes. The S. caprae ica operon contains four genes closely related to S. epidermidis and S. aureus icaA, icaB, icaC, and icaD genes (> or = 68% similarity) and is preceded by a gene similar to icaR (> or =70% similarity). The polypeptides deduced from the S. caprae ica genes exhibit 67 to 88% amino acid identity to those of S. epidermidis and S. aureus ica genes. The ica operon and icaR gene were analyzed in 14 S. caprae strains from human specimens or goats' milk. Some of the strains produced biofilm, and others did not. All strains carry the ica operon and icaR of the same sizes and in the same relative positions, suggesting that the absence of biofilm formation is not related to the insertion of a mobile element such as an insertion sequence or a transposon.

Bacteriolysis↗
PubMed2001

Contribution of glutamate dehydrogenase to mitochondrial glutamate metabolism studied by (13)C and (31)P nuclear magnetic resonance.

The relative contribution of glutamate dehydrogenase (GDH) and the aminotransferase activity to mitochondrial glutamate metabolism was investigated in dilute suspensions of purified mitochondria from potato (Solanum tuberosum) tubers. Measurements of glutamate-dependent oxygen consumption by mitochondria in different metabolic states were complemented by novel in situ NMR assays of specific enzymes that metabolize glutamate. First, a new assay for aminotransferase activity, based on the exchange of deuterium between deuterated water and glutamate, provided a method for establishing the effectiveness of the aminotransferase inhibitor amino-oxyacetate in situ, and thus allowed the contribution of the aminotransferase activity to glutamate oxidation to be assessed unambiguously. Secondly, the activity of GDH in the mitochondria was monitored in a coupled assay in which glutamine synthetase was used to trap the ammonium released by the oxidative deamination of glutamate. Thirdly, the reversibility of the GDH reaction was investigated by monitoring the isotopic exchange between glutamate and [(15)N]ammonium. These novel approaches show that the oxidative deamination of glutamate can make a significant contribution to mitochondrial glutamate metabolism and that GDH can support the aminotransferases in funneling carbon from glutamate into the TCA cycle.

Aminooxyacetic Acid↗
PubMed2001

[Parapharyngeal synovial sarcoma].

A parapharyngeal biphasic synovial sarcoma arising in a 38-year-old man is reported. The rarity of this tumor in the head and neck and its multitude of histopathologic features are responsible for frequent initial misdiagnosis. The purpose of this report is to highlight the differential diagnosis with other cervical tumors.

Adult↗