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Biomedical subjects

P Bouillon

Publications and source records attributed to P Bouillon.

12 recordsLinked to original sources
PubMed2000

Medical document anonymization with a semantic lexicon.

We present an original system for locating and removing personally-identifying information in patient records. In this experiment, anonymization is seen as a particular case of knowledge extraction. We use natural language processing tools provided by the MEDTAG framework: a semantic lexicon specialized in medicine, and a toolkit for word-sense and morpho-syntactic tagging. The system finds 98-99% of all personally-identifying information.

Computer Security↗
PubMed2000

Tagging medical texts: a rule-based experiment.

In this paper we describe the construction of a part-of-speech tagger for medical document retrieval purposes, therefore we have designed a specific architecture called minimal commitment. The system uses local grammatical rules for conducting the disambiguation task. Four evaluations are conducted, with and without taking unknown words into account. In between each evaluation the modules (lexicon, guesser, rules) of the system are incrementally improved.

Disease↗
PubMed1999

MEDTAG: tag-like semantics for medical document indexing.

Medical documentation is central in health care, as it constitutes the main means of communication between care providers. However, there is a gap to bridge between storing information and extracting the relevant underlying knowledge. We believe natural language processing (NLP) is the best solution to handle such a large amount of textual information. In this paper we describe the construction of a semantic tagset for medical document indexing purposes. Rather than attempting to produce a home-made tagset, we decided to use, as far as possible, standard medicine resources. This step has led us to choose UMLS hierarchical classes as a basis for our tagset. We also show that semantic tagging is not only providing bases for disambiguisation between senses, but is also useful in the query expansion process of the retrieval system. We finally focus on assessing the results of the semantic tagger.

Abstracting and Indexing↗
PubMed1996

Expression of the neuron-specific enolase gene by rat oligodendroglial cells during their differentiation.

We have examined the regulation of neuron-specific gamma-enolase gene (NSE) expression in oligodendrocytes at various steps of their differentiation/maturation. We have demonstrated for the first time that NSE is expressed in oligodendroglial cells in vitro and in vivo, and only at a certain stage of differentiation. A heterogeneity of the gamma subunit was observed in cultured oligodendrocytes and the same one was found in adult rat brain. The level of gamma mRNA increased when precursor cells differentiated into oligodendrocytes. By contrast, no significant change in alpha-enolase gene expression was observed. High NSE (gamma gamma and alpha gamma) enolase activity was detected in cultured oligodendrocytes. Treatment with basic fibroblast growth factor, which stimulates the proliferation of oligodendrocyte precursor cells and reversibly blocks their differentiation, resulted in lower alpha gamma- and gamma gamma-enolase activities in these cells, but it enhanced alpha alpha-enolase activity slightly. These data indicate that gamma-enolase gene expression is associated with the differentiation of the oligodendrocytes and that it is repressed in adult fully mature cells.

Aging↗
PubMed1995

Long-term induction of an aldose reductase protein by basic fibroblast growth factor in rat astrocytes in vitro.

Basic fibroblast growth factor (bFGF) is known to elicit various developmental-like effects on astrocytes in vitro, but these effects were studied mainly over short-term periods. In this work we asked the question whether bFGF could induce long-term effects on rat astrocytes in culture. This factor was found to induce only a transient mitogenic effect lasting less than 48 h, even when the treatment was carried on for 4 days. By contrast, it induced long-term effects on the rate of synthesis of several proteins as seen by two-dimensional polyacrylamide gel electrophoresis after labeling the cells with [35S]methionine. The most upregulated protein was extracted from preparative gels of soluble extracts of cultured bFGF-treated astrocytes and of normal brain. It was characterized by internal amino acid microsequencing. Two tryptic digest peptides had N-terminal sequences similar to rat lens aldose reductase. This protein was also expressed in oligodendroglial and neuronal cells in culture, but it was not upregulated by bFGF. Aldose reductase is thought to be involved in a minor pathway of glucose metabolism and in diabetic complications. Its long-term regulation by bFGF will possibly help in the understanding of its actual physiological role.

Aldehyde Reductase↗
PubMed1988

Phospholipid transfer protein: full-length cDNA and amino acid sequence in maize. Amino acid sequence homologies between plant phospholipid transfer proteins.

We have determined the primary structure of a phospholipid transfer protein (PLTP) isolated from maize seeds. This protein consists of 93 amino acids and shows internal homology originating in the repetition of (do)decapeptides. By using antibodies against maize PLTP, we have isolated from a cDNA library one positive clone (6B6) which corresponds to the incomplete nucleotide sequence. Another cDNA clone (9C2) was obtained by screening a size-selected library with 6B6. Clone 9C2 (822 base pairs) corresponds to the full-length cDNA of the phospholipid-transfer protein whose mRNA contains 0.8 kilobase. Southern blot analysis shows that the maize genome may contain several PLTP genes. In addition, the deduced amino acid sequence of clone 9C2 reveals the presence of a signal peptide. The significance of this signal peptide (27 amino acids) might be related to the function of the phospholipid-transfer protein. The amino acid sequence of maize PLTP was compared to those isolated from spinach leaves or castor bean seeds which exhibit physicochemical properties close to those of the maize protein. A high homology was observed between the three sequences. Three domains can be distinguished: a highly charged central core (around 40-60), a very hydrophobic N-terminal sequence characteristic of polypeptide-membrane interaction, and a hydrophilic C terminus. A model for plant phospholipid-transfer proteins is proposed in which the phospholipid molecule is embedded within the protein with its polar moiety interacting with the central hydrophilic core of the protein, whereas the N-terminal region plunges within the membrane in the transfer process.

Amino Acid Sequence↗
PubMed1987

The primary structure of spinach-leaf phospholipid-transfer protein.

The complete amino acid sequence phospholipid-transfer protein isolated from spinach leaves has been determined. The primary structure of the spinach protein was elucidated by analyses by HPLC of cyanogen bromide fragments and peptides obtained by tryptic digestions. The single polypeptide chain of the spinach protein consists of 91 amino acid residues. The protein contains six cysteines whereas phenylalanine and glutamine are absent. The present data, which are the first to be obtained with a phospholipid-transfer protein from a photosynthetic tissue, are compared to the amino acid sequences determined with plant and animal proteins involved in the intracellular transport of hydrophobic compounds.

Amino Acid Sequence↗
PubMed1986

[Simplified technic for the resection of aneurysms of the ascending aorta with aortic insufficiency].

The authors propose a simplified technique for the resection of dystrophic aneurysms of the ascending aorta with aortic regurgitation. The technique is based on a special method of shaping the Dacron tube, so that the proximal line of suture extends to the bottom of the sinuses of Valsalva, in front of and behind the coronary ostia. The results in 27 operated patients are reported. The global hospital mortality was nil. Seventy four per cent of patients had no complications at all 22 per cent had minor and rapidly regressive complications. The long-term results were assessed in 20 patients. There were no secondary deaths or reoperations. Angiographic and/or echocardiographic control performed in 12 cases showed no valvular dysfunction or recurrence of the aneurysmal process. The advantages of this technique are its simplicity, its good short and long-term results and the possibility of using a bioprosthesis for aortic valve replacement.

Adult↗
PubMed1984

Aorto-right ventricular shunt and associated aortic valve injury resulting from a penetrating wound of the heart.

A case of a traumatic aorto-right ventricular fistula associated with an aortic valve injury and subsequent successful treatment is reported. A possible delay in diagnosis necessitates follow-up of patients after penetrating thoracic wounds. Early surgical treatment is mandatory because of the risks of both heart failure and endocarditis and because of the low operative morbidity. An aortic approach appears to be preferable because it permits repair of both the fistula and the valvular injury. Reconstruction of valvular injuries is preferable since long-term competence without prosthetic replacement can be achieved.

Adult↗
PubMed1984

[Axillo-femoral bypass using PTFE. Early and secondary results. 104 patients].

Between 1977 and 1981, 104 patients underwent 115 axillo-femoral bypass operations (AFB). All the indications were based upon limb salvage. Ninety-nine unilateral bypasses and only 8 axillo-bi-femoral procedures were performed. Prolongation of revascularisation by femoro-popliteal bypass was necessary in 10 cases, in 1 or 2 stages. Secondary bilateralisation of an unilateral bypass was required in only 6 cases because of the development of gangrene of the other limb. The postoperative mortality was 6% (5 patients) in the gangrene group and was 33% (6 patients) in the acute ischaemia group. Study of the cumulative permeability of bypasses until the time of their first thrombosis showed that 62% were permeable at 1 year and 44% at 4 years. Thrombectomy was followed by a percentage permeability of 10%. Weight bearing was still possible by 75% of limbs after 5 years. In conclusion to this study: axillo-femoral bypass remains reserved for salvage of the limb; extension of implantations to the distal and/or pathological artery remains legitimate; PTFE seems the most suitable material at present; the development of a thrombosis in the first 18 months should be treated by thrombectomy in order to decrease the number of amputations.

Adult↗
PubMedDate not supplied

Amino-acid sequence determination of a hydrophobic region of bovine rhodopsin.

The 50 amino acid residues sequence of a hydrophobic region of bovine rhodopsin, a membrane protein of retinal rod photoreceptors of molecular weight 39,000 was determined. This primary structure determination was performed on the S5 fragment (about 12,000 molecular weight) obtained from 2-(2 nitrophenylsulfenyl)-3-methyl-3'bromo-indolenine cleavage of the protein. Automatic Edman degradation used in liquid phase was performed in presence of N-cetyl-N,N,N-trimethyl-ammoniumbromide, a cationic detergent incorporated in the proteic film. S5 is a C-terminal rhodopsin fragment and contains the phosphorylation sites. The covalent structure determined overlaps with the sequence of an already known fragment [1]; thus 25 per cent of the rhodopsin primary structure is now elucidated. Our results are in agreement with and chiefly refine the topological model for rhodopsin which correlates its membrane location and its functional sites.

Amino Acid Sequence↗