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Biomedical subjects

E Samain

Publications and source records attributed to E Samain.

At least 19 recordsLinked to original sources
PubMed2006

The decrease of fibrinogen is an early predictor of the severity of postpartum hemorrhage.

BACKGROUND: Postpartum hemorrhage (PPH) is a major source of maternal morbidity. OBJECTIVES: This study's objective was to determine whether changes in hemostasis markers during the course of PPH are predictive of its severity. PATIENTS AND METHODS: We enrolled 128 women with PPH requiring uterotonic prostaglandin E2 (sulprostone) infusion. Two groups were defined (severe and non-severe PPH) according to the outcome during the first 24 hours. According to our criteria, 50 of the 128 women had severe PPH. Serial coagulation tests were performed at enrollment (H0), and 1, 2, 4 and 24 hours thereafter. RESULTS: At H0, and through H4, women with severe PPH had significantly lower fibrinogen, factor V, antithrombin activity, protein C antigen, prolonged prothrombin time, and higher D-dimer and TAT complexes than women with non-severe PPH. In multivariate analysis, from H0 to H4, fibrinogen was the only marker associated with the occurrence of severe PPH. At H0, the risk for severe PPH was 2.63-fold higher for each 1 gL(-1) decrease of fibrinogen. The negative predictive value of a fibrinogen concentration >4 gL(-1) was 79% and the positive predictive value of a concentration <or=2 gL(-1) was 100%. CONCLUSION: These findings indicate that a simple fibrinogen measurement can anticipate the risk of severe bleeding in PPH.

Adult↗
PubMed2006

Venous thromboembolism prevention in surgery and obstetrics: clinical practice guidelines.

BACKGROUND AND OBJECTIVE: To produce up-to-date clinical practice guidelines on the prevention of venous thromboembolism in surgery and obstetrics. METHODS: A Steering Committee defined the scope of the topic, the questions to be answered, and the assessment criteria. Eight multidisciplinary working groups (total of 70 experts) performed a critical appraisal of the literature in the following disciplines: pharmacology of antithrombotic agents, orthopaedics; general surgery (gastrointestinal (GI) and varicose vein surgery); urology; gynaecology and obstetrics; thoracic, cardiac and vascular surgery; surgery of the head, neck and spine; and surgery of burns patients. The resultant reports and guidelines were submitted for comment and completion of the Appraisal of Guidelines Research & Evaluation questionnaire to a total of 150 peer reviewers, before producing definite guidelines. RESULTS: The report answers the following questions for each type of surgery: (i) What is the venous thromboembolism incidence according to clinical and/or paraclinical criteria in the absence of prophylaxis? (with stratification of venous thromboembolism risk into low, moderate and high categories); (ii) What is the efficacy and safety of the prophylactic measures used? (iii) When should prophylaxis be introduced and how long should it last? (iv) Does ambulatory surgery affect efficacy and safety of prophylaxis? CONCLUSIONS: Apart from answering the above questions, the guidelines provide a summary table for each discipline. This table stratifies types of surgery into the three risk categories, specifies the recommended prophylaxis for venous thromboembolism (pharmacological and/or mechanical) and grades each recommendation. In addition, whenever appropriate, the recommended prophylaxis is adjusted to low- and high-risk patients.

Anticoagulants↗
PubMed2005

[Prevention of venous thromboembolism following cardiac, vascular or thoracic surgery].

In the absence of thromboprophylaxis, coronary artery bypass graft surgery (CABG), intrathoracic surgery (thoracotomy or video-assisted thoracoscopy), abdominal aortic surgery and infrainguinal vascular surgery are high-risk surgeries for the development of venous thromboembolic events (VTE). The incidence of VTE following surgery of the intrathoracic aorta, carotid endarterectomy or mediastinoscopy is unknown. Data from the litterature are lacking to draw evidence-based recommandations for venous thromboprophylaxis after these three types of surgeries, and the following guidelines are but experts'opinions (Grade D recommendations). Thromboprophylaxis is recommended after CABG (Grade D), with either subcutaneous (SC) low molecular weight heparin (LMWH) or SC or intravenous (i.v.) unfractioned heparin (UH) (PTT target = 1.1-1.5 time control value) (both grade D). This may be combined with the use of intermittent pneumatic compression device (Grade B). After valve surgery. The anticoagulation recommended to prevent valve thrombosis is sufficient in order to prevent VTE. We recommend thromboprophylaxis with either LMWH or low dose UH to prevent VTE after aortic or lower limbs infrainguinal vascular surgery (both grade B and D). Vitamine K antagonists (VKA) are not recommended in this indication (Grade D). We recommend thromprophylaxis following intrathoracic surgery via thoracotomy or videoassisted thoracoscopy (grade C). Either subcutaneous LMWH or subcutaneous or i.v. low dose UH may be used (Grade C). Efficacy of intermittent pneumatic compression device has been demonstrated in a study (grade C). VKA are not recommended (grade D). No further recommendation regarding the duration of thromboprophylaxis after these three types of surgeries can be made.

Anesthesia↗
PubMed2004

[Survey on the use of mannitol in prehospital care in Paris area].

OBJECTIVE: To evaluate the use of mannitol in prehospital care in Paris area. STUDY DESIGN: Survey using telephone interviews. METHODS: Emergency physicians on duty in the 37 emergency departments in charge of prehospital care in Paris area were called by one investigator. They were asked to answer a questionnaire about their own use of mannitol in the prehospital setting. RESULTS: Ninety-six questionnaires were recorded. Physicians were anaesthesiologists (9%) or emergency physicians (87%). In three departments, mannitol was not available in the ambulances. Thirty-five per cent (n = 34) reported no use of mannitol and 17% (n = 16) just once. Fourteen physicians (15%) did not want to use it. The reasons for not using mannitol were lack of knowledge about efficacy for five, need for previous brain imaging for seven or neurosurgeon's agreement before using mannitol for three. For those who had already used mannitol or were ready to use it, the main indication was increased intracranial pressure with clinical signs of brain herniation after severe brain injury for 92% of physicians. Thirty-one % reported not knowing the dose of mannitol, 33% having a memorandum immediately available and among those who answered the question, 63% gave a value compatible with guidelines. CONCLUSION: A significant percentage of physicians tacking part in the French prehospital care system, do not follow published guidelines on the use of mannitol. Actions improving implementation of those guidelines should be supported.

Ambulances↗
PubMed2002

[Monitoring expired oxygen fraction in preoxygenation of patients with chronic obstructive pulmonary disease].

OBJECTIVES: To compare the rate of preoxygenation before induction of anesthesia in patients with no lung disease and in patients with chronic obstructive pulmonary disease (COPD). PATIENTS AND METHODS: End-tidal fractional oxygen concentration (FEO2) was monitored using a paramagnetic oxygen analyzer, during a 5 minute-period of preoxygenation (tidal breathing of 100% oxygen) in 16 control patients (control group) and in 15 patients with COPD. COPD was defined and its severity was characterized by clinical criteria and by respiratory functional tests. FEO2 increase was compared between groups using Anova. RESULTS: The increase in FEO2 was slower in the COPD group than in control group (p < 0.05). After 2 and 3 minutes of preoxygenation, FEO2 was significantly lower in COPD group as compared to control group, but was not different at 5 minutes. Mean time to reach a FEO2 equal to 0.90 was significantly longer in COPD than in control group (COPD: 261 +/- 130 s; control: 165 +/- 90 s, p < 0.05). SpO2 measured during room air breathing was moderately lower in COPD group, but this difference was no more significant after 30 s of preoxygenation (SpO2 after 30 s: control: 98.8 +/- 1.0%; COPD: 98.2 +/- 1.9%, NS). CONCLUSION: These results suggest that preoxygenation monitoring may be useful in patients with COPD, to ensure adequate preoxygenation is achieved.

Anesthesia↗
PubMed2002

[Uterine morcellation during vaginal hysterectomy: apropos of a series of 216 prospective cases].

OBJECTIVE: The purpose of this study was to compare the surgical outcomes of women undergoing vaginal hysterectomy with and without morcelation. PATIENTS AND METHOD: Between December 1999 and December 2000, 216 women underwent vaginal hysterectomy without laparoscopic assistance at the Department of Gynecology of Hôtel-Dieu hospital in Paris. The patients were divided into two groups: 114 of them underwent vaginal hysterectomies with morcelation whereas 102 underwent vaginal hysterectomies without morcelation. The two groups were compared as to demographic data, total complications, operative time, hospital stay length and peri-operative hemoglobin concentration change. RESULTS: Although women undergoing morcelation were significantly younger (mean 49 versus 52, p = 0.01) and less parous (mean 1.9 versus 2.3, p = 0.03), there were no significant differences in other surgical or anesthetic risks factors, including weight, BMI, nulliparity and preexisting surgical diseases. Mean uterine weight was significantly greater in those undergoing morcelation (331 versus 110 g, p < 0.001); operative time was increased in the group which had undergone morcelation (331 versus 110 g, p < 0.001). There were no significant differences between the two groups with respect to peri-operative hemoglobin concentration change or hospital stay length. Finally, the rate of surgical complication was similar in the two groups (17.5 versus 21.5%). CONCLUSION: Although vaginal hysterectomy requires an increase in operative time, morcelation at the time of vaginal hysterectomy is safe and facilitates the vaginal removal of enlarged uteri without increasing peri-operative morbidity.

Age Factors↗
PubMed2001

[Interference between a dual-chamber pacemaker and argon electrocautery device during hepatectomy].

We report an unusual electromagnetic interference induced by an argon electrocautery device during a left hepatectomy on a dual chamber pacemaker, implanted for sinus node dysfunction in 87-year-old patient. Argon electrocautery induced inhibition of atrial stimulation and occurrence of irregular ventricular triggered activity. Normal pacemaker function resumed after electrocautery interruption. This case illustrates the need to focus on cardiac rhythm when a new electrical device is used in a pacemaker patient.

Aged↗
PubMed2001

In vivo fucosylation of lacto-N-neotetraose and lacto-N-neohexaose by heterologous expression of Helicobacter pylori alpha-1,3 fucosyltransferase in engineered Escherichia coli.

We report here the in vivo production of type 2 fucosylated-N-acetyllactosamine oligosaccharides in Escherichia coli. Lacto-N-neofucopentaose Galbeta1-4GlcNAcbeta1-3Galbeta1-4(Fucalpha1-3)Glc, lacto-N-neodifucohexaose Galbeta1-4(Fucalpha1-3)Glc-NAcbeta1-3Galbeta1-4(Fucalpha1-3)Glc, and lacto-N-neodifucooctaose Galbeta1-4GlcNAcbeta1-3Galbeta1-4(Fucalpha1-3)GlcNAcbeta1-3Galbeta1-4(Fucalpha1-3)Glc were produced from lactose added in the culture medium. Two of them carry the Lewis X human antigen. High cell density cultivation allowed obtaining several grams of fucosylated oligosaccharides per liter of culture. The fucosylation reaction was catalyzed by an alpha-1,3 fucosyltransferase of Helicobacter pylori overexpressed in E. coli with the genes lgtAB of N. meningitidis. The strain was genetically engineered in order to provide GDP-fucose to the system, by genomic inactivation of gene wcaJ involved in colanic acid synthesis and overexpression of RcsA, positive regulator of the colanic acid operon. To prevent fucosylation at the glucosyl residue, lactulose Galbeta1-4Fru was assayed in replacement of lactose. Lactulose-derived oligosaccharides carrying fucose were synthesized and characterized. Fucosylation of the fructosyl residue was observed, indicating a poor acceptor specificity of the fucosyltransferase of H. pylori.

Chromatography, Gel↗
PubMed2001

Effect of extracellular matrix elements on angiotensin II-induced calcium release in vascular smooth muscle cells from normotensive and hypertensive rats.

The interaction of the vascular smooth muscle cells (VSMCs) with the components of the matrix determines several functions of the cell, such as growth and differentiation. In contrast, an alteration in angiotensin (Ang) II-induced Ca(2+) mechanisms in VSMCs was reported in genetic hypertension. In this study, we wished to assess the effect of different components of the extracellular matrix on the increase of [Ca(2+)](i) induced by Ang II in VSMCs from spontaneously hypertensive rats (SHR) compared with those from normotensive Wistar-Kyoto rats (WKY). Results demonstrate for the first time that elements of the extracellular matrix modulate the Ang II-induced Ca(2+) transport mechanisms. This modulation is different in cells from WKY compared with those from SHR. Thus, growing cells from SHR on collagen I, collagen IV, fibronectin, vitronectin, or Matrigel induced a significant decrease in Ang II-induced Ca(2+) release from internal stores, whereas in cells from WKY, no effect could be observed except for those grown on collagen I, which increased Ca(2+) release. Fibronectin and vitronectin, however, induced a decrease in Ang II-induced Ca(2+) influx in WKY, whereas no effect could be observed in SHR. Conversely, collagen I and collagen IV induced an increase in this influx in SHR but not in WKY, whereas Matrigel increased the influx in both strains. These results suggest a modulation of the Ang II-associated signaling events by the matrix elements via the focal adhesion points. The understanding of these synergies should provide insight into issues such as development of hypertrophy of large vessels in hypertension.

Angiotensin II↗
PubMed2000

End-tidal oxygraphy during pre-oxygenation in patients with severe diffuse emphysema.

We hypothetised that the rate of pre-oxygenation could be altered by the increase in lung volume and airflow obstruction observed in emphysema. End-tidal oxygen concentration was monitored, using a paramagnetic oxygen analyser, during 10-min pre-oxygenation (tidal breathing of 100% oxygen) in 10 normal patients and in 10 patients with severe diffuse emphysema documented by computerised tomography. Emphysema was characterised by an important increase in functional residual capacity of the lungs [190 (23)% of predicted values] and a decrease in expiratory flow. The increase in end-tidal oxygen concentration was slower in the emphysema group than in the control group (p = 0.0024). After 3 and 5 min of pre-oxygenation, the end-tidal fractional oxygen concentration was significantly lower in the emphysema group than the control group [mean (SD); value at 3 min: emphysema: 0.83 (0.06) vs. control: 0.91 (0.02), p = 0.0005]. Individual values of end-tidal oxygen concentration measured after 3, 5 and 10 min of pre-oxygenation were negatively correlated with functional residual capacity in the emphysema group, whereas no such correlation was found in the control group. These results suggest that pre-oxygenation should be monitored in patients with diffuse emphysema to ensure that adequate pre-oxygenation is achieved.

Adult↗
PubMed2000

Guidelines for perioperative cardiac evaluation from the American College of Cardiology/American Heart Association task force are effective for stratifying cardiac risk before aortic surgery.

PURPOSE: We assessed whether the American College of Cardiology/American Heart Association (ACC/AHA) task force guidelines for perioperative cardiac evaluation could reliably stratify cardiac risk before aortic surgery. METHODS: We retrospectively applied the guidelines to a closed database, set up prospectively. The setting was a referral center in an institutional practice with hospitalized patients. The closed database included 133 patients who had a routine cardiac examination, which comprised an estimation of functional capacity and noninvasive testing, before aortic surgery. This cardiac evaluation led to the proposal of coronarography in 23 patients and to treating an underlying coronary artery disease in 21 patients (including three myocardial revascularizations). One patient died after myocardial revascularization, and two patients died of cardiac causes after aortic surgery. The algorithm of the ACC/AHA guidelines was applied independently by two investigators to each patient's file that was included in the existing database. The main outcome measure was a comparison between cardiac risk stratification with the ACC/AHA guidelines and the results of the routine cardiac evaluation. RESULTS: The ACC/AHA guidelines were successfully applied to all 133 files by the two investigators. After applying the algorithm, 73 patients were stratified as low cardiac risk, and 60 patients were stratified as high risk. The 21 patients who had undergone a preoperative coronary artery disease optimization were stratified as high risk by means of the ACC/AHA guidelines. The patients who died from cardiac causes were stratified as high risk by means of the ACC/AHA guidelines, whereas none of the patients stratified as low risk died during hospitalization. CONCLUSION: The ACC/AHA guidelines were effective in stratifying cardiac risk by using clinical predictors and an estimate of the physical capacity of the patient. Their use may allow a reduction in unnecessary noninvasive testing in patients stratified as being at low risk, while permitting the selection of all patients likely to benefit from preoperative coronary artery disease optimization.

Algorithms↗
PubMed2000

The effect of propofol on angiotensin II-induced Ca(2+) mobilization in aortic smooth muscle cells from normotensive and hypertensive rats.

UNLABELLED: We studied the effect of propofol (5.6-560 micromol/L; 1-100 microg/mL) on the mechanisms involved in Ca(2+) mobilization elicited by angiotensin II (AngII) in Wistar Kyoto (WKY) and spontaneously hypertensive (SHR) rats. We studied the variations in intracellular Ca(2+) ([Ca(2+)](i)) concentrations in cultured aortic vascular smooth muscle cells (VSMCs) isolated from 6-wk-old WKY and SHR rats loaded with the Ca(2+)-sensitive fluorescent dye, Fura-2, using fluorescent imaging microscopy. In the absence of external Ca(2+), AngII (1 micromol/L) induced a transient [Ca(2+)](i) mobilization from internal stores that was larger in SHR than in WKY rats. Ca(2+) influx was assessed after external Ca(2+) (1 mmol/L) reintroduction. Propofol (1-100 microg/mL) added 5 min before the experiments did not alter AngII-induced Ca(2+) release from internal stores in either strain. By contrast, Ca(2+) influx elicited by AngII was significantly decreased by propofol. This effect occurred at a smaller concentration of propofol in the SHR than in the WKY rats. When Ca(2+) stores were depleted by exposure of cells to thapsigargin, an inhibitor of the sarcoendoplasmic reticulum Ca(2+)-ATPase, reintroduction of Ca(2+) to the medium induced a capacitative Ca(2+) influx of similar magnitude than that elicited by AngII. This influx was also significantly decreased by propofol at 100 microg/mL ( WKY: 27 +/- 3% of control values, n = 107; SHR: 16 +/- 3%, n = 47; P < 0.001). In conclusion, propofol decreased AngII-induced Ca(2+) influx through voltage-independent channels, without altering Ca(2+) release from internal stores in aortic VSMCs. The hypertensive rats were found to be more sensitive to the effect of propofol than the normotensive rats. This suggests that the response of VSMCs to AngII may be altered by propofol. IMPLICATIONS: In rat aortic vascular smooth muscle cells, propofol reduced angiotensin II-elicited Ca(2+) entry through capacitative Ca(2+) channels without altering Ca(2+) release from intracellular stores. Spontaneously hypertensive rats were more sensitive to these effects of propofol than normotensive rats. The response of vascular smooth muscle cells to angiotensin II may be altered by propofol.

Anesthetics, Intravenous↗
PubMed2000

Transforming growth factor-beta1 modulates angiotensin II-induced calcium release in vascular smooth muscle cells from spontaneously hypertensive rats.

OBJECTIVES: To investigate the role of transforming growth factor-beta1 (TGF-beta1) on Ca2+-dependent mechanisms elicited by angiotensin II in aortic vascular smooth muscle cells (VSMC) of Wistar- Kyoto (WKY) rats and spontaneously hypertensive rats (SHR). METHODS: Cai2+ release induced by angiotensin II (1 micromol/ l) was studied in cultured VSMC isolated from the aortas of 6-week-old WKY rats and SHR. Intracellular Ca2+ (Cai2+) was assessed in Fura-2 loaded cells using fluorescent imaging microscopy. Angiotensin II receptors were analysed by binding studies. RESULTS: Pretreatment of VSMC for 24 h with TGF-beta1 significantly increased angiotensin II-induced Cai2+ mobilization from internal stores in SHR, while Ca2+ influx was not altered. This effect involves tyrosine kinase and is not due to an increase in angiotensin II binding sites, or a change in the affinity of the receptors. By contrast, TGF-beta1 did not modify the response of VSMC from WKY rats to angiotensin II. CONCLUSIONS: These results help our understanding of the interactions between the pathways activated by TGF-beta1 and the G protein-coupled receptor signalling pathway, and their role in genetic hypertension.

Angiotensin II↗
PubMed2000

Thermobacillus xylanilyticus gen. nov., sp. nov., a new aerobic thermophilic xylan-degrading bacterium isolated from farm soil.

An aerobic, thermophilic, xylanolytic, spore-forming bacterium, XETP (T = type strain; P = patent strain), has been isolated from farm soil situated underneath a manure heap in northern France. Strain XETP, which stained negative in the Gram test, occurs as short rods which sometimes form chains. Its spores are ellipsoidal, central to subterminal and occur in swollen sporangia. It grows at temperatures up to 63 degrees C and in the pH range 6.5-8.5. When grown on glucose in optimal conditions, its doubling time was found to be 33 min. CO2 was observed to have a growth-stimulating effect at the start of the culture. In addition to glucose, the isolate utilizes xylose, arabinose, mannose, cellobiose, galactose, maltose, sucrose, xylan and starch. Growth is inhibited by 5% NaCl. The G+C content of strain XETP is 57.5 mol%. The 16S rDNA sequence analysis indicated that strain XETP falls into the radiation of the Bacillus-Lactobacillus-Streptococcus subdivision of the Gram-positive phylum. Its three closest phylogenetic relatives are 'Bacillus viscosus', Paenibacillus curdlanolyticus and Bacillus popilliae with identity values of 91.15, 90.94 and 90.92%, respectively. The major cellular fatty acids are 14-methyl pentadecanoic acid (16:0 iso), hexadecanoic acid (16:0) and 14-methyl hexadecanoic acid (17:0 anteiso). On the basis of 16S rRNA sequence and chemotaxonomic characteristics, the isolate is different enough for it to be considered as a member of a new genus. It is therefore proposed that this isolate represents a new genus and species: Thermobacillus xylanilyticus. Strain XETP, the type strain of Thermobacillus xylanilyticus, has been deposited in the Collection Nationale de Cultures Microbiennes (CNCM I-1017) as a patent strain.

Aerobiosis↗
PubMed2000

Extracellular signal-regulated kinase pathway is involved in basic fibroblast growth factor effect on angiotensin II-induced Ca(2+) transient in vascular smooth muscle cell from Wistar-Kyoto and spontaneously hypertensive rats.

We studied the effect of basic fibroblast growth factor (b-FGF) on different Ca(2+) mechanisms elicited by angiotensin II (Ang II) in normotensive Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR). Intracellular Ca(2+) (Ca(2+)(i)) variations were studied in cultured vascular smooth muscle cells (VSMCs) isolated from the aorta of 5- to 6-week-old WKY rats and SHR. Ca(2+)(i) was assessed in Fura-2-loaded cells with fluorescent imaging microscopy. Ang II subtype 1 receptor activation by Ang II (1 micromol/L) induced a transient increase in Ca(2+)(i) that was partially attenuated by genistein, a tyrosine kinase inhibitor. Pretreatment of VSMCs with b-FGF for 24 hours markedly stimulated the Ang II-induced Ca(2+)(i) release from the internal stores in WKY rats, whereas it was without effect in SHR. This was not consequent to a change in the affinity of Ang II subtype 1 receptors or an increase in their density. Inhibition of mitogen-activated protein kinase with PD 98059 reduced this stimulatory effect of the cytokine in the WKY rats. On the other hand, b-FGF stimulated the Ang II-induced Ca(2+) influx in both strains. Similar results were observed when Ca(2+) influx was induced with thapsigargin. Genistein and PD 98059 abolished the effect of b-FGF. These results show for the first time that b-FGF regulates Ca(2+) mechanisms induced by Ang II and that this regulation is different in SHR than in normotensive control animals. The extracellular signal-regulated kinase cascade is implicated in this cross-regulation with G protein-signaling pathway at 2 levels and possibly more: 1 at the tyrosine kinases and the other downstream of the extracellular signal-regulated kinase family. These results may prove useful in understanding the interaction between these 2 pathways and their implication in genetic hypertension.

Angiotensin II↗