Biomedical subjects

J M Rodrigues

Publications and source records attributed to J M Rodrigues.

33 records · Page 2Linked to original sources

PubMed1998

Full text multilingual automatic morphosemantems for stand-alone or Internet based applications.

The authors present an automatic tool able to provide real-time morphosemantic decomposition of natural language sentences in French, German and English. This tool demonstrates the feasibility of Natural Language Processing on standard PC computers and the technology involved has been successfully implemented in daily used applications in several European hospitals. It considerably alleviates the burden of coding with various international classification and enhances the quality of the final results. This tool, delivered on PC platforms, is highly convivial and provides a versatile interface to any existing applications based on the Microsoft Windows standards. Moreover, all high levels functions have been encapsulated in Object Oriented Components and can therefore be reused using the Common Object Model standards to develop stand-alone or Internet applications.

Classification↗

PubMed1998

Galen-In-Use: using artificial intelligence terminology tools to improve the linguistic coherence of a national coding system for surgical procedures.

GALEN has developed a language independent common reference model based on a medically oriented ontology and practical tools and techniques for managing healthcare terminology including natural language processing. GALEN-IN-USE is the current phase which applied the modelling and the tools to the development or the updating of coding systems for surgical procedures in different national coding centers co-operating within the European Federation of Coding Centre (EFCC) to create a language independent knowledge repository for multicultural Europe. We used an integrated set of artificial intelligence terminology tools named CLAssification Manager workbench to process French professional medical language rubrics into intermediate dissections and to the Grail reference ontology model representation. From this language independent concept model representation we generate controlled French natural language. The French national coding centre is then able to retrieve the initial professional rubrics with different categories of concepts, to compare the professional language proposed by expert clinicians to the French generated controlled vocabulary and to finalize the linguistic labels of the coding system in relation with the meanings of the conceptual system structure.

Artificial Intelligence↗

PubMed1997

Galen-In-Use: an EU Project applied to the development of a new national coding system for surgical procedures: NCAM.

GALEN has developed a language independent common reference model based on a medically oriented ontology and practical tools and techniques for managing healthcare terminology including natural language processing. GALEN-IN-USE is the current phase which applied the modelling and the tools to the development or the updating of coding systems for surgical procedures in different national coding centre co-operating within the European Federation of Coding Centre (EFCC) to create a multilingual knowledge repository for multicultural Europe. NCAM (Nomenclature Commune des Actes Médicaux) is the new French multipurpose coding system for surgical procedures. The labels are processed from the intermediate dissections to the Grail representation and the natural language generation by the electronically related Medical Informatics research centres network of Saint Etienne, Manchester, Geneva and Nijmegen. The national coding centre is able to retrieve the initial labels with different categories of concepts, to compare the professional language proposed by expert clinicians to the French generated controlled vocabulary and to finalize the linguistic labels of the coding system in relation with the meanings of the conceptual system structure.

Electronic Data Processing↗

PubMed1996

Retrovirus budding may constitute a port of entry for drug carriers.

This paper investigates the relation between viral infection and cell uptake of liposomes and nanoparticles. A defective virus was used to infect two types of cells: cells allowing virus budding (psi2neo cells) and cells bereft of a virus exit process (NIH 3T3 cells). This study has revealed that cell uptake of pH-sensitive-liposomes is highly dependent on the virus exit process, since it ensued only when virus budding occurred. This preferential uptake of pH-sensitive liposomes by infected cells was not carrier-specific because similar uptake was observed with non-biodegradable fluorescent nanoparticles using confocal microscopy. Also, inhibition of neo gene expression by oligonucleotide pH-sensitive-liposomes was only observed in the cell system (psi2neo) endowed with a virus exit process. Finally, increased membrane fluidity was noted in the infected cells, possibly reflecting membrane perturbation due to virus budding. We suggest that this membrane perturbation may be the key to the uptake of the different colloidal carriers. Infected cells could, thus, constitute a natural target for particulate drug carriers.

3T3 Cells↗

PubMed1996

Effect of polymeric nanoparticle administration on the clearance activity of the mononuclear phagocyte system in mice.

We investigated the consequences of acute and subacute administration of mice with polyisobutylcyanoacrylate (PIBCA), polyisohexylcyanoacrylate (PIHCA), poly(D,L-lactic) acid (PLA), and polystyrene (PS) nanoparticles on the mononuclear phagocyte system phagocytic function. This was done by measuring the clearance rate of colloidal carbon. Single administration of PIBCA and PIHCA (but not PLA and PS) nanoparticles reduced carbon clearance in both a time- and dose-dependent fashion. Since clearance of preopsonized carbon was normal, it was assumed that PIBCA and PIHCA nanoparticles deplete opsonins specific for carbon recognition. A decrease in plasma fibronectin levels resulting from nanoparticle administration suggested its implication in their removal from blood. However, fibronectin does not seem to be responsible for PIBCA and PIHCA blockade. Phagocytic function was preserved after repeated treatment with nanoparticles, probably as a result of increased Kupffer cell phagocytic activity and the contribution of spleen macrophages. Neither toxicity nor effects due to nanoparticle hepatic accumulation were observed.

Animals↗

PubMed1995

Development of an injectable formulation of albendazole and in vivo evaluation of its efficacy against Echinococcus multilocularis metacestode.

The loading of poly (D, L-lactide) nanoparticles with ABZ has led us to evaluate the potential of this new colloidal drug delivery system against E. multilocularis, using a murine model of hepatic alveolar echinococcosis. ABZ-loaded nanoparticles had a monodisperse size distribution between 100 and 150 nm. The efficiency of drug loading to nanoparticles was over 97%. In vitro, at an ABZ concentration of 1.0 microgram ml-1, the formulation had no toxicity for peritoneal macrophages harvested from uninfected mice. In vivo, the ABZ-loaded nanoparticles exhibited no signs of toxicity at any of the doses tested. Intravenous injections of 6 mg kg-1 of bound ABZ to infected mice had an equivalent antiparasitic effect on the metacestode growth to that of a treatment with 1500 mg kg-1 of orally administered free ABZ. The parasite hepatic superficial size as well as the peritoneal metastatic burden was significantly reduced by these 2 courses of treatment, as compared to those of untreated mice. Our results should encourage further study in order to explain the absence of dose-dependent efficacy of ABZ-loaded nanoparticles demonstrated in the present study.

Albendazole↗

PubMed1994

Studies of baby hamster kidney natural cell aggregation in suspended batch cultures.

Microcarrier cultures of animal cells of industrial relevance are known to shed aggregates into the suspension phase. For a BHK cell line, which is known to be prone to aggregate naturally, microcarrier and aggregate forms of culture are compared in spinner culture. In microcarrier cultures, it is shown that increasing initial microcarrier concentration yields decreasing concentration of smaller aggregates in suspension; roughly equivalent concentrations of total cells and single cells in suspension are obtained. In the absence of Cytodex 3, aggregate final size is hydrodynamically controlled in batch and semicontinuous suspension culture. Rate of agitation is the main variable controlling aggregate size in batch cultures. The range of agitation rates studied (20 to 70 rpm in 250 mL spinner flasks) produced aggregates with maximum sizes of 200 microns. Necrotic centers were not observed; this was confirmed by Trypan blue viability measurements after mechanical dissociation of aggregates and also by the constant productivity obtained from different aggregate sizes. Comparing aggregate and microcarrier culture conditions, it is shown that at 100 rpm maximum total cell concentration is larger in the absence of microcarriers; dead cell concentrations, most of which exist in suspension, are slightly larger in microcarrier culture. Total viable cell concentrations in aggregate, hydrodynamically controlled culture, are almost one order of magnitude higher than in microcarrier cultures. These results suggest that there might be advantages in using aggregate cultures under hydrodynamic control of aggregate size in lieu of microcarrier cultures for naturally aggregating cell lines.

Animals↗

PubMed1994

The activity and ultrastructural localization of primaquine-loaded poly (d,l-lactide) nanoparticles in Leishmania donovani infected mice.

The activity of primaquine (PQ) was compared to that of PQ-loaded Poly (D,L-Lactide) (PLA) nanoparticles against Leishmania donovani. The association of PQ with PLA nanoparticles increased the antileishmanial in vitro and in vivo effects of intravenously administered drug while its toxicity was reduced. The effectiveness of PQ-loaded PLA nanoparticles was 3.3 times as high as that of free drug in the suppression of amastigotes in the liver of BALB/c mice. A total dose of 30 mg PQ bound/kg (600 mg PLA/kg) was well tolerated and no sign of acute toxicity was observed. A similar dose of free drug resulted in 15% weight loss. No significant leishmanicidal activity was observed for unloaded PLA nanoparticles. Ultrastructural studies showed the uptake of drug-loaded nanoparticles by Leishmania-infected Kupffer cells. Nanoparticles were identified closed to amastigotes.

Animals↗

PubMed1989

[DRGs in Europe].

DRG projects developments in Europe are shown since 1982 until 1989 being much similar in Western Europe different countries just as Prospective Payment System was implemented in the US International intergovernmental organizations like Council of Europe, OECD, WHO Europe and European Economic Community have supported and support the new system. Diagnostics and procedures coding was the main technical issue and European countries found different ways to cope with. How to use DRGs in Europe is still the main challenge. The European use is mainly in favour of internal management, planning, performance measurement but recently the most advanced projects have decided to relate partly hospital budget to case mix bases on DRGs as an incentive to greater efficiency.

Diagnosis-Related Groups↗

PubMed1980