Biomedical subjects

S Durand

Publications and source records attributed to S Durand.

At least 19 recordsLinked to original sources

PubMed2006

Altered gene expression in cells from patients with lysosomal storage disorders suggests impairment of the ubiquitin pathway.

By comparing mRNA profiles in cultured fibroblasts from patients affected with lysosomal storage diseases, we identified differentially expressed genes common to these conditions. These studies, confirmed by biochemical experiments, demonstrated that lysosomal storage is associated with downregulation of ubiquitin C-terminal hydrolase, UCH-L1 in the cells of eight different lysosomal disorders, as well as in the brain of a mouse model of Sandhoff disease. Induction of lysosomal storage by the cysteine protease inhibitor E-64 also reduced UCH-L1 mRNA, protein level and activity. All cells exhibiting lysosomal storage contained ubiquitinated protein aggregates and showed reduced levels of free ubiquitin and decreased proteasome activity. The caspase-mediated apoptosis in E-64-treated fibroblasts was reversed by transfection with a UCH-L1 plasmid, and increased after downregulation of UCH-L1 by siRNA, suggesting that UCH-L1 deficiency and impairment of the ubiquitin-dependent protein degradation pathway can contribute to the increased cell death observed in many lysosomal storage disorders.

Animals↗

PubMed2006

Anatomical basis of arthroscopic capsulotomy for elbow stiffness.

Stiffness is a frequent condition in elbow pathologies, both traumatic and non-traumatic, and usually requires an operative treatment including an anterior capsulotomy. Elbow arthroscopy is certainly an alternative to surgery, but the technique of arthroscopic capsulotomy remains controversial. Our aim was to study the anterior elbow capsule anatomy to recommend an efficient and safe arthroscopic capsulotomy. We dissected ten cadaveric elbows and analyzed the insertions of the anterior capsule, their variations and the relationships with the surrounding neurovascular structures (radial and median nerve, brachial artery). The influence of elbow flexion was studied on fresh elbows with radioscopic evaluation. The distances between the anterior capsule and the neurovascular structures were measured at four reference levels. The insertions of the anterior capsule were also studied on the embalmed elbows. The radial nerve is always the closest structure to the capsule, but in this study it was always protected by the brachialis muscle. The distance between the anterior capsule and the neurovascular structures is consistently higher on the proximal side, regardless of which structure is considered. The 90 degrees flexion position allows the best capsular distension and offers optimal security with regard to neurovascular structures. All arthroscopic surgeons are concerned about potential neurovascular complications (varying from 0 to 14% in the literature). Previous anatomical studies examined the relationships between the arthroscopic portals and the neurovascular structures. This study developed a precise description of the relationship between the anterior capsule and the surrounding neurovascular structures, which let us recommend technical parameters to conduct a safe arthroscopic capsulotomy.

Arthroscopy↗

PubMed2006

Morphometry by computerized three-dimensional reconstruction of the human carpal bones during embryogenesis.

Carpal skeleton shows drastic developmental changes during embryogenesis. At this stage, the cartilaginous matrices appear and later form models of the limb bones. The purpose of this study was to investigate the morphometry of carpal bones in humans during embryological development. We obtained digitalized histological serial sections of 18 human embryos and early fetuses from the Institute of Anatomy in Paris. Surfdriver and MSC.Patran software were used for three-dimensional reconstruction and morphometry. There was a strong correlation between the volume of the carpal cartilaginous structure and the size of the embryos (P<0.001) and an exponential correlation between the carpal volume and the percentage of volume presented by the proximal carpal row (P=0.005). According to inertia parameters, the geometry of carpal cartilaginous structure, initially plane, becomes curved during embryogenesis. Carpal bones growth follows non-homothetic transformation. The innovations in embryo reconstruction serve as new tool for scientific investigation. A hypothesis of carpal development is proposed.

Adult↗

PubMed2006

Serum sphinganine and the sphinganine to sphingosine ratio as a biomarker of dietary fumonisins during chronic exposure in ducks.

Sphinganine concentration (Sa) and sphinganine to sphingosine ratio (Sa/So) are sensitive biomarkers of fumonisin B1 (FB1) exposure in animals and have been proposed to reveal FB1 exposure in humans. They correlate with liver and kidney toxicity and often precede signs of toxicity. However, the use of Sa and Sa/So is confusing during chronic exposure. Indeed, some authors report altered sphingolipids metabolism, whereas others fail to demonstrate significant effect. The aim of this study was to investigate the kinetics of Sa and Sa/So in the serum of ducks over a 77-day exposure to 0, 2, 8, 32 and 128 mg FB1/kg feeds. Serum biochemistry was also investigated to reveal hepatotoxicity. The results obtained indicate that the kinetics of sphingolipids and serum biochemistry are closely linked with the duration of the exposure. After a strong and rapid increase Sa and Sa/So decrease then stabilize. The lowest investigated dose able to determine a detectable effect is 2 mg/kg feeds, the Sa/So ratio being the most sensitive biomarker of FB1 exposure.

Animals↗

PubMed2006

Cytokine and Toll-like receptor mRNAs in the nasal-associated lymphoid tissues of cattle during foot-and-mouth disease virus infection.

The pharyngeal region is known to play an important role in foot-and-mouth disease virus (FMDV) infection in relation to acute disease and viral persistence. In this study, the local mucosal immune response in nasal-associated lymphoid tissue (NALT) of cattle infected with FMDV (strain O UKG 34/2001) was examined. Quantitative "real-time" RT-PCR assays were used to measure mRNA expression of cytokines (IFN-alpha, beta and gamma, IL-2, IL-1alpha and TNF-alpha) and Toll-like receptors (TLR)-3 and -4. NALTs from dorsal soft palate were collected from cattle at 7 days post-infection (dpi) and from carriers and non-carriers at 64 dpi. Expression of IFN-alpha mRNA was significantly greater in NALT during acute disease than in uninfected animals. Increased expression of IFN-gamma and IL-1alpha mRNA was also observed but was much lower than IFN-alpha expression. There was a slight increase in mRNA expression of TNF-alpha and IL-2. During persistence, TNF-alpha mRNA expression in carrier cattle was much higher than in non-carrier cattle. Expression of TLR-4 in NALT during the acute stage of infection was greater than in uninfected animals. Carrier and non-carrier cattle did not differ in respect of expression of TLR-3 and -4 mRNA in NALT.

Animals↗

PubMed2006

First isolation and characterization of a bacterial strain that biotransforms the herbicide mesotrione.

AIM: The aim of this study was to find and characterize a fungal or bacterial strain capable of metabolizing mesotrione, a new selective herbicide for control of broad-leaved weeds in maize. METHODS AND RESULTS: This strain was isolated from cloud water and showed close phylogenetic relationship with strains belonging to the Bacillus genus, based on 16S rRNA gene alignment. Kinetics of mesotrione degradation were monitored by high-performance liquid chromatography and in situ(1)H nuclear magnetic resonance spectroscopy at different concentrations. Mesotrione was completely biotransformed even at 5 mmol l(-1) concentration. 2-Amino-4-methylsulfonyl benzoic acid (AMBA) was identified as one of the metabolites, but was not the major one. CONCLUSIONS: This study reports the first rapid mesotrione biotransformation by a pure bacterial strain and the formation of several metabolites including AMBA. SIGNIFICANCE AND IMPACT OF THE STUDY: This bacterium isolated from cloud water is the first pure strain capable of rapidly degrading mesotrione.

Altitude↗

PubMed2005

Neurovascular relationships of the approaches for arthroscopic total trapeziectomy with ligamentous stabilization.

The aim of this study was to define the neurovascular relationships of the approaches used during arthroscopic total trapeziectomy with the Thompson "suspension-plasty." Fifteen fresh cadavers in which trapezio-metacarpal arthritis had been confirmed by preoperative radiographs were chosen. There were 12 women and 3 men (average age: 87 years), and small joint arthroscopy equipment was used. Two approaches for the trapezio-metacarpal joint were used: an ulnar approach situated at the ulnar border of the extensor pollicis brevis tendon and a radial approach placed at the middle of a line joining the tendons of the flexor carpi radialis and the abductor pollicis longus. A new transosseous approach at the base of the first metacarpal ("trans-M1" approach) is suggested and was used to do the ligamento-plasty. After the operation, a large skin flap was elevated in order to measure the distance between each surgical approach and the different neurovascular structures (radial artery, dividing branches of the superficial branch of the radial nerve and the end of the lateral cutaneous nerve of the forearm) and to verify the absence of neurovascular lesions. The different neurovascular structures at risk during this arthroscopic maneuver were the radial artery for the ulnar approach, the branches of the superficial branch of the radial nerve for all of the approaches and the ending of the lateral cutaneous nerve of the forearm for the radial and "trans-M1" approaches. The use of the approaches described allows arthroscopic trapeziectomy with the Thompson suspension-plasty without us having noted neurovascular lesion.

Aged, 80 and over↗

PubMed2005

[Pre-operative diagnosis of bucket-handle meniscal tears: clinical evaluation and value of arthroscan and MRI radiological criteria].

PURPOSE OF THE STUDY: It is important for both the patient and the surgeon to determine whether a meniscal lesion can be repaired before undertaking surgery. The purpose of this study was to examine the pertinence of clinical signs and determine the value of imaging findings for the preoperative diagnosis of bucket-handle meniscal tears. This preliminary study was conducted before undertaking an analysis of preoperative criteria of reparability in a homogeneous group of meniscal lesions. MATERIAL AND METHODS: This retrospective series included 33 arthroscopically-proven bucket-handle meniscal tears in patients who underwent arthrography and/or arthroscan and/or MRI preoperatively. The images were reviewed by two senior radiologists who established a consensus diagnosis. Clinically, the type of blockage and the presence of permanent flexion before surgery were noted. The following items were noted on the imaging results: fragment displacement (fragment in the notch on the coronal slice) anterior megahorn, double PCL, and serpent sign on the sagittal slice. Longitudinal, transversal extension and position of the bucket-handle were noted. We searched for correlations with the intraoperative findings. RESULTS: Fourteen patients had a history of knee blocking and 15 had permanent flexion before surgery. Only 10 patients had the typical association of blocking and flexion. Certain diagnosis of bucket-handle meniscal tear was provided by MRI (13/15), arthroscan (6/7), and arthrography (10/24) giving an equivalent sensitivity for the two slice imaging techniques. The sign of a fragment in the notch on the coronal slice was a constant finding. The double PCL sign was sensitive for medial meniscal tears and for lateral meniscal tears with associated ACL tears. The diagnosis was successfully established in all 9 patients who underwent several explorations (2 or 3). Buckle-handle meniscal tear was not identified in 9 patients (arthrography 7, MRI 2). DISCUSSION: Our findings demonstrate that the preoperative diagnosis of bucket-handle meniscal tears cannot be properly established on clinical criteria of typical blocking and/or permanent flexion. They confirm that arthrography is not contributive to diagnosis and that the absence of a slice image is detrimental to diagnosis. The sensitivity of the two slice imaging methods was similar. The key sign was the presence of a fragment in the notch on the coronal slice; in the three cases where this sign was absent, the reason was found to be the small size of the displaced fragment (resolution limit) and time between imaging and arthroscopy. The characteristic features of the bucket-handle lesions observed in this series are exactly the same as reported in earlier reports but to our knowledge provide the first data on comparative performance of arthroscan and MRI. CONCLUSION: The noninvasive nature of MRI and the possibility of assessing the meniscal wall and the quality of the meniscal tissue make MRI the exploration of choice for preoperative assessment of meniscal tears.

Adolescent↗

PubMed2005

[Not Available].

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Journal Article↗

PubMed2005

Use of confocal immunofluorescence microscopy to localize viral nonstructural proteins and potential sites of replication in pigs experimentally infected with foot-and-mouth disease virus.

Replication of foot-and-mouth disease virus in infected pig epithelium has been studied by immunofluorescence labeling of the viral nonstructural protein 3ABC and confocal microscopy. The results were correlated with viral RNA copy numbers in tissue samples from adjacent sites determined by reverse transcription-PCR (RT-PCR). Lesion formation was seen in the tongues and coronary band epithelia of infected pigs 2 days after infection. Viral replication was observed in cells of the epithelium of the tongue and coronary band but not in the associated stromal cells. Infected epithelial cells were present in the stratum spinosum, away from the lesion, with small lesions formed above the basement membrane. Viral replication was markedly reduced in tongue epithelium by day 3 postinfection but remained apparent in the coronary band tissue up to 5 days postinfection. These results were confirmed by the RNA copy number determined by RT-PCR.

Animals↗

PubMed2004

Exogenous nitric oxide inhibits sympathetically mediated vasoconstriction in human skin.

Two experiments were performed to identify whether nitric oxide (NO) inhibits sympathetically mediated vasoconstriction in human skin. In eight subjects increasing doses of sodium nitroprusside (SNP; 8.4 x 10(-6)-8.4 x 10(-3)m) were administered via intradermal microdialysis. At each dose of SNP, cutaneous vasoconstrictor responsiveness was assessed during a 3 min whole-body cold stress. The relative reduction in forearm cutaneous vascular conductance (CVC) during the cold stress was significantly attenuated for SNP doses greater than 8.4 x 10(-4)m (control: 63.0 +/- 4.1%, SNP 8.4 x 10(-6)m: 57.1 +/- 4.7%, SNP 8.4 x 10(-5)m: 57.0 +/- 3.6%, SNP 8.4 x 10(-4)m: 44.5 +/- 5.4% and SNP 8.4 x 10(-3)m: 28.8 +/- 7.9%). The second experiment was performed to identify whether this response was due to NO attenuating sympathetically mediated vasoconstriction or due to a non-specific effect of an elevated CVC secondary to SNP administration. In seven subjects forearm CVC during a whole-body cold stress was assessed at two sites: at a site dilated via microdialysis administration of SNP and at a site dilated with isoproterenol (ISO). CVC was not different between sites prior to (SNP: 0.42 +/- 0.11; ISO: 0.46 +/- 0.11 AU mmHg(-1) (AU, arbitrary units), P > 0.05) or following drug infusion (SNP: 1.36 +/- 0.21; ISO: 1.27 +/- 0.23 AU mmHg(-1), P > 0.05). The reduction in CVC during the subsequent cold stress was significantly less at the SNP site (38.1 +/- 6.2%) relative to the ISO site (65.0 +/- 5.5%; P= 0.007). These data suggest NO is capable of inhibiting sympathetically mediated vasoconstriction in the cutaneous vasculature.

Adrenergic beta-Agonists↗

PubMed2004

Prostaglandins participate in the late phase of the vascular response to acetylcholine iontophoresis in humans.

The participation of prostaglandins (PGs) in the cutaneous vasodilatation to acetylcholine (ACh) applied via iontophoresis is under debate. Using laser Doppler flowmetry, we studied the long lasting effect (20 min) of iontophoretic application (30 s; 0.1 mA) of ACh on the human forearm. Experiments were repeated (1) using deionized water instead of ACh to test the effect of current application, (2) after scopolamine treatment to inhibit muscarinic cholinergic receptors, and (3) 2 h, 3 days and 10 days following inhibition of PG synthesis with aspirin or a placebo control. Cutaneous vascular conductance (CVC) was calculated at rest (CVC(rest)), at peak vasodilatation in the first 5 min following ACh iontophoresis (CVC(peak)), and 20 min after iontophoresis (CVC(20)). The minimal CVC (CVC(min)) following iontophoresis was also determined. Cutaneous response to ACh displayed a biphasic pattern with an early and transient peak (CVC(peak): 62 +/- 8% of the maximal CVC induced by local heating (MVC)) followed by a long lasting slower vasodilatation (CVC(min): 44 +/- 6; CVC(20): 56 +/- 5%MVC). The current itself had no major effect. Scopolamine almost abolished both phases. The long lasting phase was aspirin sensitive but not the transient phase. At hour 2 post-aspirin, CVC(peak) was 61 +/- 10, CVC(min) 26 +/- 6 and CVC(20) 29 +/- 6%MVC. At day 3, CVC(peak) was 53 +/- 9, CVC(min) 22 +/- 3 and CVC(20) 25 +/- 4%MVC. At day 10, CVC(peak) was 67 +/- 10, CVC(min) 47 +/- 7 and CVC(20) 50 +/- 8%MVC. Placebo had no effect. We conclude that PGs participate in the vasodilator response following ACh iontophoresis. Previous non-steroidal anti-inflammatory drug treatments must be taken into account when studying the effect of ACh iontophoresis.

Acetylcholine↗

PubMed2004

Anodal current intensities above 40 microA interfere with current-induced axon-reflex vasodilatation in human skin.

When using iontophoresis, the 'non-specific' vasodilatation (NSV) that is observed as a result of C-fibre excitation is generally attributed to the local accumulation of protons under the anode. NSV following prolonged 100-microA anodal current application only appears after the current is stopped. Break excitation alone does not explain the delayed onset of this vasodilatation. We hypothesised that this delay could result from an anodal block and thus, that a minimal intensity would be required to achieve hyperpolarisation of primary afferent fibres (mainly C-fibres). Using laser Doppler flowmetry, cutaneous blood flow was recorded in the forearms of 8 healthy volunteers 2 min before current application, during the application and 20 min after stopping the monopolar anodal current. In protocol 1, after 2.5 min of current application at an intensity of 100 microA, the intensity was abruptly decreased to 0-80 microA for a second 2.5-min period. The onset of vasodilatation was only delayed at intensities >30 microA during this second period. In protocol 2, re-application of the current after a 50-second interruption (expected to allow for the occurrence of an axon reflex) did not interfere with the onset of vasodilatation. Thus: (1) the minimal intensity interfering with the axon reflex is far lower than that reported for C-fibre blockade in isolated nerves; (2) the results suggest that current application does not directly interfere with the vasodilator mechanisms induced by the axon reflex at the level of smooth muscle cells.

Adult↗

PubMed2004

Evidence of a myogenic response in vasomotor control of forearm and palm cutaneous microcirculations.

Previous investigations of autoregulatory mechanisms in the control of skin blood flow suffer from the possibility of interfering effects of the autonomic nervous system. To address this question, in 11 subjects cutaneous vascular responses were measured during acute changes in perfusion pressure (using Valsalva maneuver; VM) before and after ganglionic blockade via systemic trimethaphan infusion. Cutaneous vascular conductance at baseline (CVC(base)) and during the last 5 s of the VM (CVC(VM)) were measured from forearm (nonglabrous) and palm (glabrous) skin. During the VM without ganglionic blockade, compared with CVC(base), CVC(VM) decreased significantly at the palm [0.79 +/- 0.17 to 0.55 +/- 0.17 arbitrary units (AU)/mmHg; P = 0.002] but was unchanged at the forearm (0.13 +/- 0.02 to 0.16 +/- 0.02 AU/mmHg; P = 0.50). After ganglionic blockade, VM induced pronounced decreases in perfusion pressure, which resulted in significant increases in CVC(VM) at both forearm (0.19 +/- 0.03 to 0.31 +/- 0.07 AU/mmHg; P = 0.008) and palm (1.84 +/- 0.29 to 2.76 +/- 0.63 AU/mmHg; P = 0.003) sites. These results suggest that, devoid of autonomic control, both glabrous and nonglabrous skin are capable of exhibiting vasomotor autoregulation during pronounced reductions in perfusion pressure.

Adult↗

PubMed2004

GTT1/StarD7, a novel phosphatidylcholine transfer protein-like highly expressed in gestational trophoblastic tumour: cloning and characterization.

We report the cDNA cloning and characterization of GTT1/StarD7, a novel gestational trophoblastic tumour gene, initially identified by its up-regulated expression in the choriocarcinoma JEG-3 cell line with respect to their nonmalignant counterpart, complete hydatidiform mole and normal trophoblastic tissue. Using the differential display fragment as a probe we screened placenta and HeLa cDNA libraries and isolated a clone carrying a 3315 bp insert (accession number AF270647). This cDNA encodes a protein of 295 amino acid residues with a molecular weight of approximately 34.7 kDa and a pI of 5.79. Computer-mediated homology search revealed that the deduced amino acid sequence had similarity to phosphatidylcholine transfer protein (PCTP) with a conserved StAR-related lipid transfer (START) domain extending between the amino acids 66 to 250. The GTT1 gene contains at least 9 exons spread nearly 30 kb on chromosome 2p12-2p11.2. Northern blot assays of total RNA derived from normal early placenta (NEP), complete hydatidiform mole (CHM) and JEG-3 cell line revealed a 3.5 kb mRNA expressed exclusively in the JEG-3 cell line. However, semiquantitative RT-PCR analysis performed with the same RNA samples demonstrated GTT1 expression throughout all of them with the highest level in JEG-3 cell line. Examination of GTT1 mRNA expression by semiquantitative RT-PCR assays in a series of tumour cell lines indicated wide-spread GTT1 expression with predominance in both choriocarcinoma JEG-3 and JAR cells, colorectal adenocarcinoma HT29 and hepatocellular carcinoma HepG2 cells. In conclusion, the highly GTT1 expression profile in JEG-3 and JAR cell lines and its lipid binding domain suggest that GTT1 may play an important role in the phospholipid-mediated signalling of trophoblastic tumour cellular events.

Amino Acid Sequence↗

PubMed2004

Skin surface cooling improves orthostatic tolerance in normothermic individuals.

Previous studies suggest that skin surface cooling (SSC) preserves orthostatic tolerance; however, this hypothesis has not been experimentally tested. Thus the purpose of this project was to identify whether SSC improves orthostatic tolerance in otherwise normothermic individuals. Eight subjects underwent two presyncope limited graded lower-body negative pressure (LBNP) tolerance tests. On different days, and randomly assigned, LBNP tolerance was assessed under control conditions and during SSC (perfused 16 degrees C water through tube-lined suit worn by each subject). Orthostatic tolerance was significantly elevated in each individual due to SSC, as evidenced by a significant increase in a standardized cumulative stress index (normothermia 564 +/- 58 mmHg.min; SSC 752 +/- 58 mmHg.min; P < 0.05). At most levels of LBNP, blood pressure during the SSC tolerance test was significantly greater than during the control test. Furthermore, the reduction in cerebral blood flow velocity was attenuated during some of the early stages of LBNP for the SSC trial. Plasma norepinephrine concentrations were significantly higher during LBNP with SSC, suggesting that SSC may improve orthostatic tolerance through increased sympathetic activity. These data demonstrate that SSC is effective in improving orthostatic tolerance in otherwise normothermic individuals.

Adaptation, Physiological↗

PubMed2003

Sphinganine to sphingosine ratio and predictive biochemical markers of fumonisin B1 exposure in ducks.

The kinetics of free sphinganine (Sa), sphinganine to sphingosine ratio (Sa/So), proteins, cholesterol, alanine aminotransferase (ALAT) and lactate dehydrogenase (LDH) were investigated in the course of fumonisin B1 (FB1) exposure in ducks (20 growing males divided into four groups of 5 receiving, respectively, a daily dose of 0, 5, 15 or 45 mg/kg FB1 via oral administration over 12 days). Descriptive statistics of these parameters were also studied in a large number of ducks not exposed to mycotoxins and free of known pathology. Although the toxin at the end of the treatment affected all the parameters investigated, only 2 days of treatment appeared necessary to increase free Sa concentrations in serum, whereas 6 days were necessary to detect a significant effect on Sa/So ratio. Significant differences between control and treated ducks were observed after 4 days of treatment for ALAT and LDH and after 6 and 8 days for cholesterol and proteins concentrations. The minimum doses of FB1 required to determine an effect were assessed using three different methods. This approach reveals that FB1 has greater effects when it is ingested at a low dose for a long time than when ingested at a high dose for a short time. Although the minimum toxic dose of FB1 in ducks remains to be determined, this result must be considered in the context of chronic exposure to the toxin, not only in avian populations.

Alanine Transaminase↗

PubMed2003

Genome-based detection methods of Macrobrachium rosenbergii nodavirus, a pathogen of the giant freshwater prawn, Macrobrachium rosenbergii dot-blot, in situ hybridization and RT-PCR.

The availability of specific and rapid detection methods is essential for monitoring the health status of farmed species, particularly in viral diseases as in this case early diagnosis is a critical factor in containing disease outbreaks. Three complementary genome-based methods were developed for the detection of Macrobrachium rosenbergii nodavirus (MrNV), i.e. dot-blot hybridization, in situ hybridization and reverse transcriptase-polymerase chain reaction (RT-PCR). Detection limits were established for dot-blot hybridization and RT-PCR and are c. 7 fg and 8 pg of viral RNA, respectively. In situ hybridization indicated that infection was confined to the striated muscle tissue. As a result of its sensitivity, RT-PCR can be used for in-depth investigations to examine the extent of the viral infection and establish the onset of infection in hatcheries. The application of RT-PCR on samples collected from prawn farms in China showed the possible use of this method in routine health monitoring.

Animals↗