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Biomedical subjects

G Moulin

Publications and source records attributed to G Moulin.

At least 37 records · Page 2Linked to original sources
PubMed2001

Effects of acetate and butyrate during glycerol fermentation by Clostridium butyricum.

The effects of acetate and butyrate during glycerol fermentation to 1,3-propanediol at pH 7.0 by Clostridium butyricum CNCM 1211 were studied. At pH 7.0, the calculated quantities of undissociated acetic and butyric acids were insufficient to inhibit bacterial growth. The initial addition of acetate or butyrate at concentrations of 2.5 to 15 gL(-1) had distinct effects on the metabolism and growth of Clostridium butyricum. Acetate increased the biomass and butyrate production, reducing the lag time and 1,3-propanediol production. In contrast, the addition of butyrate induced an increase in 1,3-propanediol production (yield: 0.75 mol/mol glycerol, versus 0.68 mol/mol in the butyrate-free culture), and reduced the biomass and butyrate production. It was calculated that reduction of butyrate production could provide sufficient NADH to increase 1,3-propanediol production. The effects of acetate and butyrate highlight the metabolic flexibility of Cl. butyricum CNCM 1211 during glycerol fermentation.

Acetates↗
PubMed2001

Diagnosis and treatment of juvenile nasopharyngeal angiofibroma.

The aim of this retrospective study was to compare clinical and radiological findings and discuss optimal surgical approach in patients with juvenile nasopharyngeal angiofibroma (JNA). Forty-three cases of JNA were treated at our institution from 1975 to 1999. Thirty-three male patients aged between 8 and 25 years (mean 15.3) were included. Twenty-nine patients underwent primary surgical treatment at our institution and four were treated for recurrence following primary surgery elsewhere. Tumors were staged according to Fisch's staging. Preoperative embolization was performed in 22 cases. Surgical techniques consisted of the transantral approach, lateral rhinotomy approach, transmaxillary via midfacial degloving approach, and the subtemporal preauricular infratemporal fossa approach. Tumors were classified stage I in seven cases, stage II in 11, stage III in 13 and stage IV in two. The mean delay between the initial symptom and surgery was 14 months overall, 18 months for stage I, 14 for stage II, 13 for stage III and 12 for stage IV. The transantral approach was used in 11 patients, lateral rhinotomy approach in 11 cases, transmaxillary via midfacial degloving approach in three patients, and pre-auricular infra-temporal approach in eight patients. Mean follow-up after surgery was 56 months. Six patients had recurrent tumors. Surgery is the gold standard for treatment of JNA. Modern imaging techniques allow accurate diagnosis and staging of JNA. Our experience and a review of the literature shows that the surgical approach should be selected according to tumor stage.

Adolescent↗
PubMed2001

Optimization of the wheat puroindoline-a production in Pichia pastoris.

AIMS: A recombinant puroindoline-a (rPIN-a) was produced using the methylotrophic yeast Pichia pastoris. METHODS AND RESULTS: In fed-batch culture, the production of rPIN-a decreased after 24 h of methanol induction. Most of the rPIN-a was not soluble in the culture medium remaining bound to the cell walls. Soluble and membrane-bound rPIN-a were quantified by ELISA after Triton X-114 phase partitioning. In order to improve the production of rPIN-a, the influence of pH, specific growth rate and the addition of TX-114 was tested on two independent continuous cultures. The production of rPIN-a was improved when continuous culture was carried out at 29 degrees C under acid conditions (pH 5) with a low dilution rate (D=0.025 h(-1)). The addition of 0.01% TX-114 to the medium inverted the ratio between the secreted and the membrane-bound rPIN-a. CONCLUSION: When a continuous culture was carried out under optimized conditions, the rPIN-a production yield was increased 10-fold to 14 mg l(-1) and 80% of the rPIN-a was soluble. SIGNIFICANCE AND IMPACT OF THE STUDY: This study would be helpful to optimize the expression of other membrane-bound proteins in P. pastoris.

Culture Media↗
PubMed2001

Cannabis arteritis revisited--ten new case reports.

The purpose of this paper was to revisit the old concept of cannabis arteritis first described in the 1960s and report 10 new cases. Ten male patients, with a median age of 23.7 years developed subacute distal ischemia of lower or upper limbs, leading to necrosis in the toes and/or fingers and sometimes to distal limb gangrene. Two of the patients also presented with venous thrombosis and three patients were suffering from a recent Raynaud's phenomenon. Biological test results did not show evidence of the classical vascular risk factors for thrombosis. Arteriographic evaluation in all cases revealed distal abnormalities in the arteries of feet, legs, forearms, and hands resembling those of Buerger's disease. A collateral circulation sometimes with opacification of the vasa nervorum was noted. In some cases, arterial proximal atherosclerotic lesions and venous thrombosis were observed. All patients were moderate tobacco smokers and regular cannabis users. Despite treatment with ilomedine and heparin in all cases, five amputations were necessary in four patients. The vasoconstrictor effect of cannabis on the vascular system has been known for a long time. It has been shown that delta-8- and delta-9-tetrahydrocanabinols may induce peripheral vasoconstrictor activity. Cannabis arteritis resembles Buerger's disease, but patients were moderate tobacco smokers and regular cannabis users. These cases show that prolonged use of cannabis could be an additive risk factor for juvenile and young adult arteritis. Cannabis arteritis is a forgotten and severe occlusive vascular disease occurring in young adults. Search for cannabis use may be an important tool for a better knowledge of arteritis in young smokers.

Adolescent↗
PubMed2000

Inhibition of Clostridium butyricum by 1,3-propanediol and diols during glycerol fermentation.

1,3-Propanediol inhibition during glycerol fermentation to 1,3-propanediol by Clostridium butyricum CNCM 1211 has been studied. The initial concentration of the 1,3-propanediol affected the growth of the bacterium more than the glycerol fermentation. mu(max) was inversely proportional to the initial concentration of 1,3-propanediol (0-65 g l(-1)). For glycerol at 20 g l(-1), the growth and fermentation were completely stopped at an initial 1,3-propanediol concentration of 65 g l(-1). However, for an initial 1,3-propanediol concentration of 50 g l(-1) and glycerol at 70 g l(-1), the final concentration (initial and produced) of 1,3-propanediol reached 83.7 g l(-1)(1.1 M), with complete consumption of the glycerol. Therefore, during the fermentation, the strain tolerated a 1,3-propanediol concentration higher than the initial inhibitory concentration (65 g l(-1)). The addition of 1,2-propanediol or 2,3-butanediol (50 g l(-1)) in the presence of glycerol (50-100 g l(-1)), showed that 2-diols reduced the mu(max) in a similar way to 1,3-propanediol. The measurement of the osmotic pressure of glycerol solutions, diols and diol/glycerol mixtures did not indicate any differences between these compounds. The hypothesis of diol inhibition was discussed. Taking into account the strain tolerance of highly concentrated 1,3-propanediol during fermentation, the fermentation processes for optimising production were considered.

Butylene Glycols↗
PubMed2000

Serial anatomy of the larynx in MRI: MRI-histologic correlations.

The larynx is an organ with a complex anatomic structure. MRI allows the performance of sections in the three planes of space, so that this study of the soft parts of the larynx yields results superior to those of other imaging techniques. Together with laryngoscopy, MRI is most often used in assessing the extension of malignant laryngeal tumors. This assessment is fundamental in choosing the indications for surgery, but the published reports of MRI of the larynx are sometimes discordant. The visualization of certain important anatomic structures such as the conus elasticus is uncertain. Our aim was to study the MRI radio-anatomy of the larynx based on correlations between MRI and histologic sections. Eight anatomic specimens were studied: four in the transverse plane, two in the sagittal plane, and two in the frontal plane. The MRI and histologic sections made at the same levels were compared. These comparisons allowed a description of the sectional radio-anatomy of the larynx and an assessment of the reliability and limitations of MRI. All the major anatomic structures could be identified. It was possible to demonstrate the conus elasticus. We were able to visualize the vocal process of the arytenoid cartilage, which has not to our knowledge been previously described in the literature.

Aged↗
PubMed2000

Iatrogenic dissection of the portal vein during TIPS procedure.

Dissection of the portal vein is a rare entity which has been rarely described during transjugular intrahepatic portosystemic shunt (TIPS) procedure. We report three cases of dissection during this procedure and their complications. One dissection was immediately treated with coaxial stents. The two others were complicated either by a thrombus or by a false aneurysm. In the first case a second parallel stent was used to treat this complication. The patient with the portal vein false aneurysm was transplanted 4 days after this diagnosis. Portal vein dissection in TIPS procedure appeared to be less rare than has been reported and must be considered as a potential cause of TIPS dysfunction.

Adult↗
PubMed2000

Radiological follow-up of inverted papilloma.

The aim of this study was to describe cross-sectional imaging features of recurrent papilloma of the nasal fossa and paranasal sinuses and to evaluate the role of MR and CT in the postoperative follow-up of this lesion. Magnetic resonance imaging and CT of ten patients who presented recurrence of inverted papilloma were reviewed and correlated to initial imaging, endoscopy, and surgical reports. Imaging patterns of recurrent inverted papilloma are identical to those of initial tumors and recurrence location is closely related to the site of the former lesion. Magnetic resonance is more efficient than CT for the diagnosis and evaluation of extensions. Magnetic resonance supplies the deficiencies of endoscopy in case of extensions to the frontal sinus or the lateral recess of the antrum, especially if mucosal hyperplasia or sinusitis is associated. Magnetic resonance imaging is the first imaging modality to perform in the follow-up after removal of inverted papilloma.

Adult↗
PubMed2000

Late complications after prosthetic replacement of the ascending aorta: what did we learn from routine magnetic resonance imaging follow-up?

OBJECTIVE: Advances in surgical technique have improved early survival after surgery of the ascending aorta. However, follow-up data document serious late complications, mainly evolutive peri-prosthetic false aneurysms. Magnetic resonance imaging (MRI) has proved to be highly effective for monitoring these complications. This study evaluates 10 years of experience with routine MRI for follow-up. METHODS: Since January 1988, 114 patients with replacement of the ascending aorta either for type A acute dissection (group I, 45 patients) or aneurysms (group II, 69 patients) were followed up with annual MRI. Prosthetic replacement was either limited to supra-coronary ascending aorta (45%, 51/114) or extended to the aortic root and/or the aortic arch (55%). Biological glue was always utilized. MRI focused on peri-prosthetic haematoma, analyzing signal intensity changes and volume augmentation for early detection of false aneurysms, and on persistent residual dissection with or without evolutive aortic aneurysm distant to the prosthesis. RESULTS: Peri-prosthetic hematomas were almost equally found in both groups (26 (58%) in group I and 42 (61%) in group II) and were detected within the first year. Peri-prosthetic false aneurysms developed in 15 patients (group I, seven; group II, eight) as a complication of pre-existing hematomas and were indicated for elective reoperation. Forty-three (96%) of patients in group I had persistent residual dissection. Five patients in group I and two in group II needed reoperation for evolutive aortic aneurysm. In total, 22 of 114 (19%) patients were reoperated on during follow-up (12 (27%) in group I and ten (15%) in group II). Operative mortality was 13% (3/22). Freedom from reoperation at 1 year/5 years was: group I, 93%/84%; group II, 98%/88%. CONCLUSION: Peri-prosthetic haematoma occurs equally after aneurysm or dissection repairs and is a pre-existing condition for peri-prosthetic false aneurysm; biological glue or extended repair do not prevent late complications. Long-term MRI follow-up allows successful elective reoperation for life-threatened but asymptomatic patients.

Adult↗
PubMed1999

[Cannabis-induced arteritis vs. Léo Buerger disease. Nosologic discussion apropos of two new cases].

BACKGROUND: We observed two cases of juvenile endarteritis which might suggest a possible link between Winiwarter-Buerger disease and cannabis-induced endarteritis. CASE REPORTS: Our two patients were young men aged 18 and 20 years. Both developed acute distal ischemia of the lower or upper limbs with arteriographic evidence suggestive of Winiwarter-Buerger disease. Both smoked regularly but not excessively and both used cannabis regularly. In one case, the therapeutic response to withdrawal of cannabis was good. In the second, use of cannabis continued and arterial disease persisted. DISCUSSION: The cause of Winiwarter-Buerger disease remains elusive although smoking is undoubtedly involved in the pathogenic mechanism. Our two cases recall the cannabis-induced endarteritis described in the sixties in Kif smokers in North Africa. The main clinical and radiographical features in this condition are the same as in Winiwarter-Buerger disease. CONCLUSION: Winiwarter-Buerger disease and cannabis-induced endarteritis are 2 very similar conditions. The probably rare finding of juvenile endarteritis mimicking thromboangeitis obliterans should, in our opinion, be considered as a secondary and possibly toxic effect of cannabis.

Adolescent↗
PubMed1999

Hereditary amyloid cardiomyopathy caused by a variant apolipoprotein A1.

Autosomal dominant hereditary amyloidosis with a unique cutaneous and cardiac presentation and death from heart failure by the sixth or seventh decade was found to be associated with a previously unreported point mutation (thymine to cytosine, nt 1389) in exon 4 of the apolipoprotein A1 (apoA1) gene. The predicted substitution of proline for leucine at amino acid position 90 was confirmed by structural analysis of amyloid protein isolated from cardiac deposits of amyloid. The subunit protein is composed exclusively of NH2-terminal fragments of the variant apoA1 with the longest ending at residue 94 in the wild-type sequence. Amyloid fibrils derived from four previously described apoA1 variants are composed of similar fragments with carboxyl-terminal heterogeneity, but contrary to those variants, which all carry one extra positive charge, the substitution Leu90Pro does not result in any charge modification. It is unlikely, therefore, that amyloid fibril formation is related to change of charge for a specific residue of the precursor protein. This is in agreement with studies on transthyretin amyloidosis in which no unifying factor such as change of charge for amino acid residues has been noted.

Amino Acid Sequence↗
PubMed1999

Cytoplasmic accumulation of peanut agglutinin-binding glycoconjugates in the cells of primary melanoma correlates with clinical outcome.

In an experimental model, human melanoma cell lines enriched for cells that express the glycoconjugate B-D galactose N-acetyl-D-galactosamine, which reacts with the peanut agglutinin lectin (PNA), are associated with an increase in the frequency of metastases. We previously showed that this glycoconjugate is expressed on the cells of some primary melanomas in humans and that such cells are found selectively in melanomas with a high risk for developing metastases and causing death. Using fixed archival tissues from 99 primary melanomas and lectin histochemistry, we found 65 tumors that contained melanoma cells that were PNA-positive. PNA-reactive cells were not identified in normal melanocytes or in the nevocytes of 24 nevi. PNA-reactive material accumulates adjacent to the nucleus in the area of the Golgi apparatus, initially as a tiny dot, but later in quantities sufficient to displace and indent the nucleus, producing a signet ring cell-like appearance. Tumor cells containing PNA-reactive material were associated with more evolved, deeper, and thicker tumors. Two melanomas up to Clark level II were PNA positive (20%), compared with 60% of level III, 76% of level IV, and 100% of level V. Five of 13 tumors less than 0.76 mm thick (39%) were positive, compared with 50% of tumors 0.76 to 1.49 mm thick, 64% of tumors 1.5 to 2.99 mm thick, and 85% of tumors 3 mm thick or thicker. PNA-reactivity was negatively correlated with disease-free survival (PNA-negative, 49.2+/-23 months; PNA-positive grade 1, 41.6+/-26 months and PNA-positive grade 2, 24.4+/-23 months), survival rate 5 years after initial treatment (PNA-negative, 84.8%; PNA-positive grade 1, 63.8%; and PNA-positive grade 2, 31.3%) and disease-free survival at 5 years after initial treatment (PNA-negative, 69.7%; PNA-positive grade 1, 53.2%; and PNA-positive grade 2, 25%).

Cytoplasm↗
PubMed1999

Hemodynamics and wall mechanics after stent placement in swine iliac arteries: comparative results from six stent designs.

PURPOSE: To compare the hemodynamics and wall mechanics of swine iliac arteries after placement of six types of stent. MATERIALS AND METHODS: Stents were placed in the iliac artery of 18 pigs (three pigs each underwent placement with one of six types of stent); 16 untreated pigs served as control animals. Iliac arterial hemodynamics and wall mechanics were measured 4 days after placement. RESULTS: Four stents (Palmaz-Schatz, Cordis, Warren, NJ; and Strecker, Cragg, and Symphony, Boston Scientific/Vascular, Natick, Mass) caused decreased pulsatile flow rate in the treated and contralateral iliac arteries; one (Memotherm; Bard, Covington, Ga) caused increased flow pulsatility; and one (Wallstent; Schneider, Plymouth, Minn) had no effect. No compliance mismatching was noted for the Cragg, Symphony, and Memotherm stents, whereas a decrease in compliance was noted for the Palmaz-Schatz, Strecker, and Wallstent designs. The Palmaz-Schatz and Strecker stents caused increased arterial wall rigidity, the Symphony and Wallstent designs had no effect, and the Memotherm and Cragg stents caused decreased wall rigidity. Stents made of stiff metal yielded different early results than did stents made of the less rigid nitinol. CONCLUSION: Soon after implantation, the six stent designs elicited varying changes in blood flow, arterial compliance, and arterial wall mechanics. Contralateral arterial flow also was affected.

Animals↗
PubMed1999

[X-ray imaging in assessing the extent of laryngeal cancer].

Partiel surgery of the larynx for cancer should achieve the same carcinological control as total laryngectomy, while at the same time preserving the voice and swallowing. Establishing the extent of the tumour and its relationships with the anatomical structures of the larynx allows a treatment plan to be formulated. Decisions are taken in the light of investigation in which modern imaging plays a fundamental part. The authors have made a comparison of the relative value of CT scanning and MRI as a function of the area involved in the lesion. At present MRI is required only when there is uncertainly of the extent of the subglottic extension, or invasion of the cartilages. We give a prediction of the development of the technique of vitual endoscopy, which will yield a three-dimensional view of the relationships between the tumour and the cartilaginous structures.

Humans↗