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Biomedical subjects

Guy Moulin

Publications and source records attributed to Guy Moulin.

12 recordsLinked to original sources
PubMed2006

Overexpression and characterization of two human salivary proline rich proteins.

Proline rich proteins (PRP) are among major human saliva constituents and are known to interact with wine tannins that are involved in astringency. To characterize these interactions, a human salivary proline rich pro-protein, PRB4S, was overexpressed in Pichia pastoris. Six recombinant proteins resulting from maturation in bioreactor were detected by SDS-PAGE analysis between 15 and 45 kDa (apparent molecular weight). Two of them, the 45 and the 15 kDa ones, were isolated from culture supernatant by adsorption and permeation chromatography. They were characterized by N-terminal sequencing and MALDI-TOF analysis after trypsic digestion. The 45 kDa protein is glycosylated while the 15 kDa one was obtained after a furin-like proteolysis. Both of them are similar to human whole saliva PRP resulting from proteolysis of PRB4S pro-protein in Golgi network and known as II-1 and IB-5. Because of their sensitivity to proteolysis or their unusual mobility on SDS-PAGE gel, these recombinant proteins seem to be intrinsically unstructured proteins.

Glycosylation↗
PubMed2006

Endovascular embolization of symptomatic arteriovenous fistulas secondary to lower-limb in situ venous bypass grafts.

PURPOSE: To evaluate the safety and efficacy of endovascular treatment of symptomatic arteriovenous (AV) fistulas associated with femoropopliteal in situ venous bypass grafts. MATERIALS AND METHODS: Twenty-one patients underwent embolization of symptomatic AV fistulas associated with lower-limb bypass with use of the saphenous vein (n = 16) or femoral vein (n = 5). The procedures were performed with microcatheters and metallic coils. Indications for embolization were venous congestion (n = 15) and arterial insufficiency (n = 6). Eight patients had persistent lower-limb edema, seven had painful inflammatory skin thickening, three had intermittent claudication, and three had nonhealing ulcers. RESULTS: Forty-four AV fistulas were embolized. Symptoms of venous congestion regressed completely in 12 of 15 patients (80%). Partial symptom improvement was achieved in three other patients (20%), two of whom had persistent lower-limb edema and bypass with use of the femoral vein. Five of six patients with ischemic symptoms (83%) had complete symptom relief. One patient (17%) whose ischemic ulcer did not recover despite successful embolization of AV fistulas required an amputation 4 months later. Overall, 17 of 21 patients (81%) showed complete recovery of clinical symptoms. There was no bypass occlusion during follow-up (mean, 17.5 months; range, 1-45 months). CONCLUSIONS: Embolization of symptomatic AV fistulas secondary to lower-limb in situ venous bypass is a safe and efficient alternative to surgical ligature. Complete regression of clinical symptoms is less likely when the bypass is performed with use of the femoral vein.

Aged↗
PubMed2006

A modified procedure for transjugular intrahepatic portosystemic shunt flow reduction.

The authors present a modified transjugular intrahepatic portosystemic shunt (TIPS) flow reduction procedure to treat TIPS-related refractory hepatic encephalopathy, giving the results and follow-up on six patients. A 6-mm-diameter Uni Wallstent was introduced over a guide wire and deployed beyond the angulated portion of the TIPS. A Wallgraft was then introduced over the same guide wire, pushed through the Uni Wallstent coaxially, and deployed in the TIPS. All cases were technically and clinically successful. There were no deaths in the first month after the procedure. In this study, three patients had more than 1 year's patency.

Adolescent↗
PubMed2005

Recombinant expression and anti-microbial activity of anti-lipopolysaccharide factor (ALF) from the black tiger shrimp Penaeus monodon.

Anti-lipopolysaccharide factors (ALFs), originally characterized from horseshoe crabs, have been recently identified from hemocytes of the black tiger shrimp, Penaeus monodon, by a genomic approach. In order to characterize the properties and biological activities of this immune effector in shrimp, ALFPm3, the most abundant isoform found in P. monodon, was expressed in the yeast Pichia pastoris. Large-scale production in fermentor provided 262 mg/l of recombinant ALFPm3 which was purified to homogeneity by single chromatography step on expanded-bed Streamline SP6XL. The rALFPm3 was further characterized in terms of N-terminal sequencing and mass spectrometry. Anti-microbial assays demonstrated that rALFPm3 has a broad spectrum of anti-fungal properties against filamentous fungi, and anti-bacterial activities against both Gram-positive and Gram-negative bacteria, associated with a bactericidal effect. Interestingly, rALFPm3 is highly efficient against various Vibrio species including strains pathogenic for shrimp. Finally, a synthetic peptide corresponding to a part of the putative LPS-binding site of ALFPm3 was shown to display activities mainly directed against Gram-positive bacteria indicating the involvement of the full molecule to the anti-microbial activity for Gram-negative bacteria.

Amino Acid Sequence↗
PubMed2005

A novel lipase/acyltransferase from the yeast Candida albicans: expression and characterisation of the recombinant enzyme.

A gene encoding an extracellular lipase (CaLIP4) from Candida albicans was successfully expressed in Saccharomyces cerevisiae after mutagenesis of its unusual CUG serine codon into a universal one. The ability of this lipase, which shares 60% sequence homology with the lipase/acyltransferase from Candida parapsilosis, to synthesise esters was investigated. CaLIP4 behaved as a true lipase, displaying activity towards insoluble triglycerides and having no activity in the presence of short-chain fatty acid (FA) esters and phosphatidylcholine. Methyl, ethyl and propyl esters were efficiently used. The lipase exhibited highest selectivity for unsaturated FA. With saturated FAs, C14-C16 acyl chains were preferred. In a biphasic aqueous/lipid system, CaLIP4 displayed a high alcoholysis activity with a range of alcohols (e.g. methanol, ethanol, propanol and isopropanol) as acyl acceptor. During the course of the alcoholysis reaction, new esters are produced at concentrations above the thermodynamic equilibrium of the esterification reaction, indicating that ester synthesis does not proceed by esterification but mainly by direct acyltransfer. Ester synthesis is under kinetic control due to the high rate of alcoholysis. Unwanted hydrolysis is limited by competition between the acyl acceptor (alcohol) and water for the acyltransfer reaction, favouring the alcohol.

Acyltransferases↗
PubMed2004

High-level expression of Candida parapsilosis lipase/acyltransferase in Pichia pastoris.

Candida parapsilosis has been previously shown to produce a lipase/acyltransferase (EC 3.1.1.3) that preferentially catalyses transfer reactions such as alcoholysis over hydrolysis in the presence of suitable nucleophiles other than water, even in aqueous media (aw > 0.9 ). This enzyme has been shown to belong to a new family of lipases. The present work describes the cloning of the gene coding for this lipase/acyltransferase in the yeast Pichia pastoris and the heterologous high-level expression of the recombinant enzyme. The lipase/acyltransferase gene, in which the sequence encoding the signal peptide was replaced by that of the alpha-factor of Saccharomyces cerevisiae, was placed under the control of the methanol inducible promoter of the alcohol oxidase 1 gene (AOX1). A transformed P. pastoris clone, containing five copies of the lipase/acyltransferase gene, was selected for the production of recombinant enzyme. The fed-batch culture supernatant contained 5.8 gl(-1) (weighted) of almost pure recombinant lipase/acyltransferase displaying the same catalytic behavior as the original enzyme.

Amino Acid Sequence↗
PubMed2003

Identification of a triacylglycerol lipase gene family in Candida deformans: molecular cloning and functional expression.

The yeast Candida deformans CBS 2071 produces an extracellular lipase which was shown to catalyse the production of various esters by the esterification of free fatty acids, even in the presence of a large molar excess of water. To clone the gene encoding this extracellular lipase, Saccharomyces cerevisiae was transformed with C. deformans genomic libraries and screened for lipolytic activity on a medium containing rapeseed oil emulsion and rhodamine B. Three members of a lipase gene family (CdLIP1, CdLIP2 and CdLIP3) were cloned and characterized. Each deduced lipase sequence has a Gly-His-Ser-Leu-Gly-(Gly/Ala)-Ala conserved motif, eight cysteine residues and encodes an N-terminal signal sequence. MALDI-TOF mass spectrometry analysis of a proteolytic digest of the lipase produced was used to obtain experimental evidence that the CdLIP1 gene encoded the extracellular lipase. Recombinant expression studies confirmed that the cloned genes encoded functional lipases. The three lipases are very similar to lipases from the related species Yarrowia lipolytica. Significant homologies were also found with several yeast and fungal lipases. As C. deformans CBS 2071 was previously considered to be synonymous with Y. lipolytica, the strains were compared for the extent of nucleotide divergence in the variable regions (D1/D2) at the 5'-end of the large-subunit (26S) ribosomal DNA (rDNA) gene. This rDNA region has diverged sufficiently to suggest that C. deformans is a separate species. The nucleotide sequences of the CdLIP1, CdLIP2 and CdLIP3 genes will appear in the EMBL nucleotide sequence database under Accession Nos AJ428393, AJ428394 and AJ428395, respectively.

Amino Acid Motifs↗
PubMed2003

Severe relapsing polychondritis occurring after ear piercing.

We describe a case of relapsing polychondritis with laryngo-tracheal involvement, occurring after ear piercing in a 39-year-old woman. Polychondritis was clearly time-related to ear piercing. This association draws attention to the risk of relapsing polychondritis during body art practices with cartilage trauma.

Adult↗
PubMed2002

Efficacy of local molsidomine delivery from a hydrogel-coated angioplasty balloon catheter in the atherosclerotic porcine model.

PURPOSE: To evaluate the therapeutic effects of local molsidomine delivery via a hydrogel-coated angioplasty balloon catheter during overstretch angioplasty in atherosclerotic swine iliac vessels. Molsidomine is retained in the arterial wall after local delivery for more than 72 hr and is slowly metabolized into linsidomine, releasing nitric oxide (NO). METHODS: A hydrogel-coated angioplasty balloon catheter was used to both deliver drug locally (150 mg molsidomine or placebo in the contralateral vessel) and dilate iliac vessels in nine Pietrin pigs that had been on an atherogenic diet for 5 months. Animals were killed at 3 hr (n = 2), 24 hr (n = 3) and 3 months (n = 3) after treatment. Iliac arteries were examined for wall pulsatility, histomorphometry, cell proliferation and platelet aggregation. RESULTS: No significant therapeutic effects were detected 3 hr after treatment. At 24 hr, wall pulsatility, thromboresistance and vascular cell homeostasis were significantly restored in the molsidomine-treated versus placebo group. At 3 months, molsidomine inhibited restenotic lesion development, except in scarred areas of histologically detectable adventitial/medial dissection. CONCLUSION: Local delivery of concentrated molsidomine from a hydrogel-coated angioplasty balloon catheter resulted in early NO-dependent vasodilation/stress normalization and antithrombotic and antiproliferative effects. In the medium term, molsidomine inhibited restenosis in the absence of vessel dissection.

Analysis of Variance↗
PubMed2002

The lipase/acyltransferase from Candida parapsilosis: molecular cloning and characterization of purified recombinant enzymes.

Candida parapsilosis has been previously shown to produce a lipase (i.e. able to catalyze efficiently the hydrolysis of insoluble lipid esters such as triacylglycerols) that preferentially catalyses transfer reactions such as alcoholysis in the presence of suitable nucleophiles other than water, even in aqueous media with high (> 0.9) water thermodynamic activity. The present work describes the cloning and the overexpression of the gene coding for this enzyme. Two ORFs (CpLIP1 and CpLIP2) were isolated. The deduced 465-amino-acid protein sequences contained the consensus motif (G-X-S-X-G) which is conserved among lipolytic enzymes. Only one of the two deduced proteins (CpLIP2) contained peptide sequences obtained from the purified lipase/acyltransferase. Homology investigations showed that CpLIP2 has similarities principally with 11 lipases produced by C. albicans (42-61%) and the lipase A from Candida antarctica (31%) but not with the other lipases sequenced so far. Both CpLIP1 and CpLIP2 were expressed in Saccharomyces cerevisiae, but only CpLIP2 coded for an active protein. The substrate specificity and the catalytic behavior of purified recombinant CpLIP2, with or without a C-terminal histidine tag, were not changed compared to those of the native lipase.

Acyltransferases↗
PubMed2002

Virtual laryngotracheal endoscopy based on geometric surface modeling using spiral computed tomography data.

This prospective study describes the clinical utility of virtual endoscopy based on geometric surface modeling of the laryngotracheal lumen. Eighteen children with dyspnea related to either subglottic angioma (n = 5) or laryngotracheal stenosis (n = 13) were included. All patients underwent video-recorded operative endoscopy, spiral computed tomography, and 3-dimensional reconstruction of the laryngotracheal lumen. Modeling was achieved by contour detection on spiral computed tomographic images and reconstruction using a geometric shape-recognition algorithm. The generated surface was used for diagnosis and measurement using interactive and automatic tools. Findings of virtual endoscopy and operative endoscopy were compared. Virtual endoscopy confirmed narrowing of the airway in all cases. In 9 cases, high-grade stenosis prevented complete operative endoscopy, but virtual endoscopy allowed accurate assessment and measurement of the stenosis. The findings of operative and virtual endoscopy were concordant in 9 cases. We conclude that surface modeling provides valuable information for preoperative evaluation of laryngotracheal narrowing. The ability to assess extraluminal anatomy provides a clearer picture of overall disease involvement. In the future, virtual endoscopy will probably be used in conjunction with operative endoscopy for therapeutic decision-making. Noninvasive virtual endoscopy could become an alternative to traditional endoscopy under general anesthesia for therapeutic follow-up.

Adolescent↗