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S Schlumberger

Publications and source records attributed to S Schlumberger.

At least 19 recordsLinked to original sources
PubMed2001

Interaction of melanin-concentrating hormone (MCH), neuropeptide E-I (NEI), neuropeptide G-E (NGE), and alpha-MSH with melanocortin and MCH receptors on mouse B16 melanoma cells.

Melanin-concentrating hormone (MCH) and alpha-melanocyte-stimulating hormone (alpha-MSH) are known to exhibit mostly functionally antagonistic, but in some cases agonistic activities, e.g., in pigment cells and in the brain. Neuropeptide E-I (NEI) displays functional MCH-antagonist and MSH-agonist activity in different behavioral paradigms; the role of neuropeptide G-E (NGE) is not known. This study addressed the question of possible molecular interactions between alpha-MSH, MCH and the MCH-precursor-derived peptides NEI and NGE at the level of the pigment cell MCH receptor subtype (MCH-Rpc) and the different melanocortin (MC) receptors. Radioreceptor assays using [125I]MCH, [125l]alpha-MSH and [125I]NEI as radioligands and bioassays were performed with MCI-R-positive and MC1-R-negative mouse B16 melanoma cells and with COS cells expressing the different MC receptors. The IC50s of alpha-MSH and NEI or NGE for [125I]MCH displacement from mouse MCH-Rpc were 80-fold and, respectively, >300-fold higher than that of MCH, and the IC50s for MCH and NEI or NGE for [125I]alpha-MSH displacement from mouse MC1-R were 50,000-fold and >200,000-fold higher than that of alpha-MSH. No high-affinity binding sites for NEI were detected on B16 melanoma cells and there was no significant displacement of [1251]alpha-MSH by MCH, NEI or NGE with MC3-R, MC4-R and MC5-R expressed in COS cells. At concentrations of 100 nM to 10 microM, however, MCH, NEI and NGE induced cAMP formation and melanin synthesis which could be blocked by agouti protein or inhibitors of adenylate cyclase or protein kinase A. This shows that mammalian MCH-precursor-derived peptides may mimic MSH signalling via MC1-R activation at relatively high, but physiologically still relevant concentrations, as e.g. found in autocrine/paracrine signalling mechanisms.

Animals↗
PubMed2000

Assessment of systematic use of intraoperative transesophageal echocardiography during cardiac surgery in adults: a prospective study of 203 patients.

OBJECTIVE: To determine the usefulness of systematic intraoperative transesophageal echocardiography in a cardiac surgical unit. DESIGN: Open prospective observational survey. SETTING: University Hospital. PARTICIPANTS: Consecutive adult patients (n = 203) undergoing elective or urgent cardiac operations. MEASUREMENTS AND MAIN RESULTS: Pre-cardiopulmonary bypass imaging yielded unsuspected findings in 26 patients (12.8%) and changed the planned surgery in 22 patients (10.8%). Transesophageal echocardiography modified the diagnosis in eight patients (17%) operated on for mitral valvulopathy, in seven patients (15.5%) with aortic valvular disease, in four patients (4.6%) with coronary artery disease, in five patients operated on for thoracic aorta diseases regardless of their localization (18.5%), and in two miscellaneous cases. On the basis of the data obtained from the transesophageal echocardiography carried out at the end of cardiopulmonary bypass, an immediate reintervention was required in five cases (2.5%). CONCLUSIONS: It is concluded that systematic intraoperative transesophageal echocardiography significantly affected decision making in this cardiac surgical unit. Its routine use in all cardiac surgical patients is recommended.

Adult↗
PubMed1999

Haemodynamic assessment of hypovolaemia under general anaesthesia in pigs submitted to graded haemorrhage and retransfusion.

We have compared the value of different variables used in the assessment of blood loss during progressive hypovolaemia and resuscitation under general anaesthesia in anaesthetized pigs. We measured mean arterial pressure (MAP), pulmonary capillary wedge pressure (PCWP), the negative component of the systolic arterial pressure variation (delta Down) and left ventricular end-diastolic area (LVEDa) using echocardiography. Blood was progressively withdrawn (up to 35 ml kg-1 in seven steps) and then reinfused after the same pattern. Regression coefficient (r) and normalized slope (nS) of the regression relationship between each variable and amount of blood loss were determined. The difference between the withdrawal and reinfusion curves was assessed by the area between the curves. We also estimated the minimal loss of blood volume which induced significant changes in each variable compared with that under control conditions during withdrawal of blood (minWBV) and maximal loss in blood volume which induced no significant changes in a variable compared with control conditions during retransfusion (maxRBV). During haemorrhage, MAP decreased (from mean 74 (SD 9) to 31 (5) mm Hg; P < 0.001), delta Down increased (from 1.2 (1.4) to 11.4 (4.2) mm Hg; P < 0.001), PCWP decreased (from 6.2 (2.1) to 0.3 (1.0) mm Hg; P < 0.001) and LVEDa decreased (from 13.8 (2.0) to 5.1 (2.0) cm2; P < 0.01). The highest r values were obtained with MAP and LVEDa, and the highest nS value with delta Down. The least difference between withdrawal and reinfusion was with LVEDa, the lowest values of minWBV were with PCWP and LVEDa, and the highest value of maxRBV was obtained with PCWP. During progressive haemorrhage under general anaesthesia, LVEDa was an accurate variable for assessment of blood volume loss, delta Down contributed no further information compared with MAP, and PCWP was the most reliable variable for assessing return to baseline blood volume.

Anesthesia, General↗
PubMed1997

Intraoperative transesophageal echocardiographic assessment of vascular anastomoses in lung transplantation. A report on 18 cases.

BACKGROUND: In patients after lung transplantation, dysfunction of pulmonary venous and artery anastomoses leading to reoperation is described. METHODS AND RESULTS: Pulmonary artery and vein anastomoses were evaluated intraoperatively by monoplane transesophageal echocardiography (TEE) in 18 patients undergoing lung transplantation (nine right, five left single lung transplantations, and four bilateral transplantations). All 13 right pulmonary artery anastomoses and all 22 pulmonary vein anastomoses could be visualized by TEE. None of the nine left pulmonary anastomoses could be visualized. Of the 13 right pulmonary anastomoses, 12 were considered normal, their diameter ranging from 1 to 1.7 cm (mean, 1.26 +/- 0.24 cm). A moderate stenosis of one pulmonary artery anastomosis was identified but did not require reoperation. Of the 22 pulmonary vein anastomoses, 16 were considered normal, their diameter being > 0.5 cm and the peak systolic flow velocity < or = 1 m/s at the location of the anastomoses. In five cases, the anastomoses were not considered normal, but reoperation was not indicated. In one case, a severe stenosis of pulmonary vein associated with graft dysfunction led to an early reoperation. CONCLUSION: Intraoperative TEE during lung transplantation contributes to the immediate evaluation of pulmonary vein and right pulmonary artery anastomoses and allows immediate surgical correction. Further investigations are necessary to establish threshold values requiring reoperation.

Adolescent↗
PubMed1996

[Emergency cardiac transplantation].

Emergency cardiac transplantation is a controversial subject in the present context of a lack of donor organs. There are few reports in the literature, which the authors review to suggest a practical approach which is clearly not consensual. The results in the literature report an extramortality of 10 to 30% if the indication of transplantation is that of an emergency. The poor results of emergency transplantation in the present day context of lack of donor organs have led the authors to abandon this indication. They only transplant patients in a stable condition without failure of organs other than the heart.

Actuarial Analysis↗
PubMed1995

[Long-term results of cardiac transplantation].

Between 1982 and 1992, 73 patients who had undergone cardiac transplantation and survived the hospital period, were followed up. The actuarial survival was 86%, 65% and 40% at 1, 5 and 7 years. The main causes of the 14 secondary deaths were infection (4), acute rejection (3) and cancer (3). Survival was complicated by acute rejection (1.07 episodes/patient), infection (0.7 episode/patient), cancer, hypertension and renal failure, graft dysfunction and other more secondary side effects. After analysing all the complications, the authors evaluated the quality of long-term survival after cardiac transplantation which allowed one patient out of two to return to normal living but with the threat of secondary graft dysfunction.

Actuarial Analysis↗
PubMed1993

Clonidine premedication for coronary artery bypass grafting under high-dose alfentanil anesthesia: intraoperative and postoperative hemodynamic study.

The purpose of this study was to assess the efficacy of clonidine in achieving perioperative hemodynamic stability in patients undergoing coronary artery bypass grafting performed under high-dose alfentanil anesthesia. Twenty-four patients with left ventricular ejection fraction greater than 0.5 were prospectively studied in a double-blind manner; those requiring emergency procedures were excluded. They were randomized to receive either oral clonidine or placebo together with their premedication. Induction of anesthesia was achieved with 10 mg of alfentanil infused over 5 minutes followed by a continuous infusion of 60 mg/h during 1 hour, or until sternotomy, and then 30 mg/h until the end of surgery. Hemodynamic responses to noxious stimuli were treated with additional alfentanil boluses and isoflurane when these were unsuccessful. Intraoperative hemodynamic profile analyses showed a continuous increase in systemic vascular resistance and mean arterial pressure in the clonidine group from the time of skin incision until the onset of bypass, whereas the cardiac output profiles remained similar in the two groups. The number of additional alfentanil boluses was similar. Isoflurane requirements (1/11 v 4/13) were not significantly different, but only a few patients required this therapy. The postbypass hemodynamic profiles were similar. Severe hemodynamic impairment occurred in the clonidine group during warming in the postoperative period: this group showed a drop in systemic vascular resistance index (1276 +/- 347 v 1757 +/- 415 dyn.sec.cm-5.m2) that could not be compensated for by an increase in cardiac output despite normal filling pressures, causing hypotension (66 +/- 10 v 79 +/- 16 mmHg). This hemodynamic status led to greater requirements for vasoactive agents and inotropics in this group.(ABSTRACT TRUNCATED AT 250 WORDS)

Alfentanil↗
PubMed1992

Effects of aprotinin on hemorrhagic complications in ARDS patients during prolonged extracorporeal CO2 removal.

The effects of aprotinin, a broad-based proteinase inhibitor, in the management of hemorrhagic complications during prolonged venovenous extracorporeal CO2 removal in patients with adult respiratory distress syndrome are not evaluated. In two patients, aprotinin infusion was added to heparin to treat bleeding, occurring after few days of bypass and responsible for respiratory and hemodynamic deterioration. After aprotinin infusion (loading dose of 2 x 10(6) kIU followed by a continuous infusion of 5 x 10(5) kIU/h) combined with heparin, bleeding vanished until the end of bypass.

Adult↗
PubMed1992

[Etomidate modifies hemodynamic response to fentanyl in patients with impaired left ventricular function].

The haemodynamic effects and the side-effects of anaesthesia using high doses of fentanyl were compared in two groups of 12 patients each. All the patients had poor left ventricular function and were scheduled for elective coronary artery bypass graft surgery or valvular replacement. Patients were randomly assigned to either group. In group EF, patients were given 5 micrograms.kg-1 of fentanyl, followed by 0.3 mg.kg-1 of etomidate. Once they had lost consciousness, they were given 15 mg of pancuronium and 25 micrograms.kg-1 of fentanyl over a 5 min period. Patients in group F received the full 30 micrograms.kg-1 dose of fentanyl over a 5 min period, followed by 15 mg of pancuronium. The patients were intubated 2 min after the end of the fentanyl infusion. They were mechanically ventilated with 100% oxygen. Anaesthesia was maintained with a continuous infusion of fentanyl (total dose 100 micrograms.kg-1). The usual haemodynamic parameters were monitored and calculated, as well as pain during injection of the drugs, myoclonia, chest wall rigidity and the time to loss of consciousness. The two groups were comparable with respect to age, weight, height and surgery. One third of the patients in group EF complained of pain during etomidate injection. The time required to loose consciousness was shorter in group EF (55 +/- 16 sec) than in group F (177 +/- 56 sec) (p < 0.001). The cardiac index decrease in group EF (2.0 +/- 0.4 l.min-1.m-2 vs. 1.9 +/- 0.4 l.min-1.m-2) (p < 0.05), respectively between the time just before tracheal intubation (T1), and 10 min after tracheal intubation (T3).(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, Intravenous↗
PubMed1991

High-dose alfentanil for myocardial revascularization: a hemodynamic and pharmacokinetic study.

It has been suggested that high plasma levels of alfentanil are required in order to control hemodynamic responses to noxious stimuli in patients undergoing myocardial revascularization. The present study was designed to determine the hemodynamic profile in 10 patients and the time course of alfentanil plasma concentrations and pharmacokinetics (7 patients) during and following coronary artery surgery using alfentanil administration based on an overdosage principle. Premedication consisted of lorazepam, 0.07 mg/kg, given 2 hours before surgery. Ten milligrams of alfentanil was given over 5 minutes for anesthesia induction, followed by an infusion of 60 mg/h until sternotomy and 30 mg/h up to skin closure. Additional 5-mg boluses were given prior to noxious intraoperative events. Hemodynamic measurements were performed prior to cardiopulmonary bypass. Blood was sampled simultaneously prebypass and then during the postbypass period for determination of alfentanil plasma levels. The very high alfentanil plasma concentrations achieved provided satisfactory intraoperative conditions in most, but not all, patients. Recovery time was short, despite the large amounts of narcotic used. It is concluded that very high doses of alfentanil associated with lorazepam premedication resulted in hemodynamic stability and markedly elevated narcotic plasma concentrations in most patients. Such plasma levels seem to provide satisfactory anesthetic conditions.

Alfentanil↗
PubMed1989

[Autotransfusion].

Explore the source record for details and available documents.

Blood Transfusion, Autologous↗
PubMed1987

[Clinical experience with the Saint Jude prosthesis. Results over a period of 7 years].

Between January, 1979 and December, 1985, 193 Saint Jude medical valves (SJM) were implanted in 165 patients (74 male, 91 female) aged from 14 to 78 years (mean age: 49 years). 101 patients underwent aortic valve replacement, 36 had mitral valve replacement and 21 had multiple valve replacement. Fitting with an SJM prosthesis was a primary emergency operation for 15 patients (9%) and a reoperation for 49 patients (31%). A concomitant surgical procedure was carried out in 39 patients (24%). The overall peri-operative mortality rate was 9% (15 patients), this figure falling to 5% (6/112 patients) when emergency surgery and reoperations are excluded. No patient was lost sight of. Mean follow-up was 37 +/- 3 months (range: 4 to 84 months), for a total duration of 413 years/patient. Five patients died of heart disease during the follow-up period, representing a mortality rate of 1.2% per year/patient. The actual survival rate was calculated as 90% at 1 year and 83% at 7 years. During that period 7 thromboembolic accidents occurred among 5 patients (actual rate: 1.7 accident per 100 years/patient). Two mechanical valve desinsertions requiring reoperation were recorded. Altogether, the actuarial rate of patients without any post-operative complication was 88% at 1 year and 65% at 7 years. Functional improvement was dramatic since 94% of survivors are now in class I or II, whilst 67% of patients were in class III or IV prior to surgery. It may be concluded that the mid-term

Actuarial Analysis↗
PubMed1986

[Aneurysm of the aortic arch. Surgical therapy. 60 cases].

Sixty patients with aortic arch aneurysm have been operated upon at the Foch Medico-Surgical Centre between 1964 and 1984. This period can be subdivided into: January, 1964 to December, 1975 (24 cases) and January, 1976 to April, 1984 (36 cases). The technique used (closure by patch or segmental replacement prosthesis) depended on the type of lesion encountered. In most cases, the cardiopulmonary bypass was between the femoral artery and the right atrium. After experimenting with different methods, we now protect the brain by selective cold blood carotid perfusion, using independent circuit and heat-exchanger. Operative mortality was 12% in series I (1964-1975) and 0% in series II (1975-1984) patients. Hospital mortality was 25% in series I and 13% in series II patients. The improvements obtained during the last few years, using cold blood carotid perfusion and circulatory arrest in the lower half of the body, have made it possible to perform open distal anastomoses. This method ensures excellent brain protection and short cardiopulmonary bypass period.

Adult↗