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L Roussel

Publications and source records attributed to L Roussel.

At least 19 recordsLinked to original sources
PubMed2005

Kinetic and inhibition studies of cinnamoyl-CoA reductase 1 from Arabidopsis thaliana.

Cinnamoyl coenzyme A reductase (CCR, EC 1.2.1.44), one of the key enzymes in the biosynthesis of lignin monomers, catalyzes the NADPH-dependent reduction of cinnamoyl-CoA esters to their corresponding cinnamaldehydes. AtCCR1, one of the two distinct isoforms isolated from Arabidopsis thaliana, was shown to be involved in lignin biosynthesis during development. Here, we report on the purification of the recombinant AtCCR1 protein expressed in Escherichia coli and the subsequent determination of its kinetic properties (K(m) and k(cat)/K(m) values) towards its main substrates i.e. feruloyl-CoA, sinapoyl-CoA, and p-coumaroyl-CoA esters. In addition, the potential inhibitory effect of five substrate-like analogs possessing an N-acetylcysteamine thioester group was tested on CCR activity using either feruloyl-CoA or sinapoyl-CoA as substrates. The K(i) values were in the range of 4.4-502 microM and the type of inhibition was found to be either uncompetitive or noncompetitive. Interestingly, for compounds 3 and 5, the type of inhibition was found to be different depending on the substrate used to monitor the enzyme activity. The best inhibitors were those possessing the feruloyl (compound 3) and sinapoyl (compound 5) aromatic moiety (4.1 and 7.1 microM) while the enzyme activity was monitored using the corresponding substrates.

Acyl Coenzyme A↗
PubMed2003

[Potential pro-thrombotic effects of cyclooxygenase-2. inhibitors Two cases pf myocardial infarction].

Type 2 cyclo-oxygenase inhibitors are new anti-inflammatory drugs with better gastrointestinal tolerance than traditional non-steroidal anti-inflammatory drugs. They have no platelet anti-aggregant effects and there is still some discussion as to whether this new therapeutic class has any pro-thrombotic effects. The authors report two cases of myocardial infarction in patients considered to be at low risk treated by type 2 cyclo-oxygenase inhibitors.

Adult↗
PubMed2002

The effect of hypertonic saline dextran solutions on hypoxic pulmonary vasoconstriction in anaesthetised piglets.

Hypoxic pulmonary vasoconstriction (HPV) is a regulatory mechanism by which blood is diverted from poorly ventilated to better ventilated areas of the lung. The aim of the present study was to assess the extent to which hypertonic saline dextran and dextran solutions modify the magnitude of HPV during isovolumic haemodilution in intact acutely instrumented piglets. Eighteen large white piglets were anesthetised and assigned to two groups. Mean pulmonary arterial pressure (PAP) and cardiac output (Q), systemic arterial pressure and left arterial pressure (LAP) were measured. A decrease in Q was obtained by reducing venous return. This enabled measurement of transpulmonary pressures (mean PAP minus LAP) at four levels of Q in hyperoxia (inspiratory oxygen fraction (FiO2)=0.4) then in hypoxia (Fi,O2=0.1) in the two groups before blood soustraction (10 mL x kg(-1)) and after loading with sodium chloride (NaCl) 7.5% and dextran 6% or with dextran 6% alone. Dextran alone led to a decrease in mean PAP-LAP/Q values, and NaCl with dextran was associated with a significant shift of mean PAP-LAP/Q plots to higher pressures in hypoxia. Hypertonic saline dextran solution, as replacement fluid in isovolaemic haemodilution increased the magnitude of hypoxic pulmonary vasoconstriction, whereas dextran solution reduced it.

Anesthesia, Inhalation↗
PubMed2000

Effects of sevoflurane on hypoxic pulmonary vasoconstriction in anaesthetized piglets.

In vitro, halogenated agents reduce the pulmonary vasoconstrictor response to alveolar hypoxia in isolated perfused lungs. However, studies in intact animals have been less convincing. The aim of the present study was to assess the effect of sevoflurane on hypoxic pulmonary vasoconstriction (HPV) in anaesthetized piglets using the pressure/cardiac index relationship (P/Q). Ten large white piglets were anaesthetized and mechanically ventilated, alternately in hyperoxia (FIO2 = 0.4) and hypoxia (FIO2 = 0.12). Multipoint plots of pulmonary arterial pressure (PAP) or differences between PAP and left atrial pressure (LAP) against Q were generated by gradual inflation of a balloon introduced into the inferior vena cava. P/Q relationships were established in hyperoxia and hypoxia at baseline, and then with sevoflurane. In hypoxia, pressure gradients (PAP-LAP) increased at every level of Q, thus demonstrating active pulmonary vasoconstriction. Sevoflurane at 1 MAC did not affect these P/Q relationships in hyperoxia or hypoxia as compared with baseline. Sevoflurane at a clinically relevant concentration (1 MAC) has no significant effect on HPV in anaesthetized piglets.

Anesthesia, Inhalation↗
PubMed1999

[Arterial hypertension due to compression of the renal artery, revealing ovarian cancer].

BACKGROUND: The etiologic work-up of hypertension with hyperaldosteronism and elevated serum renin includes search for renal artery stenosis. Intrinsic stenosis is a common finding, but hypertension secondary to extrinsic compression of the renal artery is exceptional. CASE REPORT: A 48-year-old woman with an uneventful history was hospitalized for recent onset hypertension. Laboratory tests showed hypokaliemia, and elevated aldosterone and renin. Duplex Doppler exploration of the renal vessels evidenced extrinsic compression of the left renal artery by a tumoral mass found to be a nodal metastasis at surgery. Pathology reported cancer of the ovary. Blood pressure, and aldosterone and renin levels returned to normal after complete tumor resection. No antihypertensive treatment was required. CONCLUSION: This is undoubtedly the first case of metastatic cancer of the ovary revealed by hypertension; it can be added to the list of 49 other published cases of extrinsic compression of the renal artery by various causes leading to hypertension. In most cases, surgical removal of the obstacle or nephrectomy provided cure of the hypertension.

Female↗
PubMed1996

Stent implantation in acute myocardial infarction.

Among 138 patients treated with coronary angioplasty during acute myocardial infarction (AMI), 35 (25%) had stent implantation. Mean age was 56 years and 83% were men. Mean onset of chest pain was 6.0 +/- 5.3 hours, and previous thrombolytic therapy was given to 10 patients (29%). Infarct location was anterior in 19 (54%), inferior in 14 (40%), and lateral in 2 patients (6%). Thrombolysis in Myocardial Infarction trial flows 0,1, and 2 were seen in 24 (69%), 6 (17%), and 5 patients (14%), respectively. The culprit vessel was the left anterior descending artery in 18 (51%), right coronary artery in 14 (40%), left circumflex in 2 (6%), and left main coronary artery in 1 patient (3%). Mean vessel diameter was 3.3 +/- 0.3 mm. Indications were: primary in 5 (14%), suboptimal result in 8 (23%), nonocclusive dissection in 14 (40%), and occlusive dissection in 8 patients (23%). Angiographic thrombus after initial angioplasty was present in 12 patients (34%). A total of 46 stents were implanted; mean balloon diameter and pressure were 3.4 +/- 0.4 mm and 15.5 +/- 2.2 atm, respectively. Residual diameter stenosis was 4 +/- 7%. There were 2 deaths; sudden 1, and after elective coronary artery bypass grafting in the other; 2 patients (6%) had groin hematomas. Mean hospitalization was 9.9 +/- 5.0 days. Repeat angiography revealed no stent occlusion. With initial intravenous heparin for 3 to 7 days, all patients received aspirin and ticlopidine for 1 month. Thus, AMI is not a contraindication for stent implantation. The benefits of stenting are a high success rte, low residual diameter stenosis, and low incidence of in-hospital recurrent ischemia. Reduction in restenosis rate in this setting is likely but remains to be determined.

Aged↗
PubMed1996

[Acute obstructive renal failure and scrotal complete hernia of the bladder. Apropos of a case, review of the literature].

Massive herniation of the bladder into the scrotum is uncommon and can have a deleterious effect on the upper urinary tract. We report a case where complete scrotal hernia of the bladder lead to obstructive renal failure due to torsion of the trigone. Most simple bladder hernias can be explained by a prostate or uretral obstacle. The mechanism in our patient with no known prostate or uretral disease was the passage of the bladder via a defective inguinal canal caused by excessive obesity. This type of massive hernia has been reported in Sumo boxers. The effect on the upper urinary tract may be related to a fold in the terminal ureter or more exceptionally in the trigone. Immediate treatment requires urine drainage above the obstacle and intensive care. After stabilization, the anatomic position of the excluded bladder is re-established with reconstruction of the inguinal area, usually with a prosthesis. Any obstacle below the bladder must be removed.

Acute Kidney Injury↗
PubMed1992

[Fatal poisoning caused by African viper's bite (Echis carinatus)].

The case is reported of a 44-year-old European who was bitten on the foot in Djibouti, probably by an African viper. Unusually, there wasn't any pain, nor any cardiovascular collapse nor any local swelling. An oedema of the lower limb started the day afterwards. Two days after the bite, the patient presented a generalized haemorrhagic syndrome, which led to his admission. There was a consumption of fibrinogen and prothrombin, without any decrease in the platelet count. Heparin was started (100 IU.kg-1.day-1), as well as fluid replacement (albumin, fresh frozen plasma, packed red cells). This allowed him to be transferred to France, where he arrived in anuria, with hyperpyrexia, and severe lower limb oedema and a haemorrhagic syndrome. There was a major extensive retroperitoneal haematoma spreading to the perineum. The four limbs were ischaemic. The patient's condition continued to worsen, developing hypoxic pulmonary oedema. He died on the seventh day after the bite, during a session of haemodialysis, from cardiovascular failure resistant to all the usual drugs. The principles of anti-venom therapy are recalled. Indeed, this should be started early enough and relies on large amounts of serum (greater than 50 ml).

Adult↗
PubMed1990

Duplex sonographic findings in a popliteal vein aneurysm.

We report on a new case of popliteal vein aneurysm, a rare anomaly almost always presented by pulmonary emboli. Usually the lesion is demonstrated on phlebography. However it is possible to establish the diagnosis with duplex sonography. A short review of the literature is included.

Adult↗