[HSV1-derived vectors: a powerful and flexible system for genes transfers]. / Les vecteurs amplicons dérivés du virus HSV1 : un système souple et puissant pour le transfert de gènes.

Amplicons are non-integrative defective herpes simplex type 1 (HSV1) derived vectors. Their genomes are entirely free of viral genes, making these vectors non toxic for infected cells and non pathogenic for inoculated animals. In addition, amplicon vectors possess the unique property of delivering up to 150 kbp of foreign DNA. These characteristics make amplicon vectors one of the most powerful and promising viral vectors for gene transfer. This review illustrates several interesting applications using amplicon vectors, as well as problems that need to be resolved in order to obtain stable and physiological transgene expression.

Hemodynamic effect of calcium channel blockade during anesthesia for coronary artery surgery.

Because the choice of anesthetic technique does not influence the incidence of perioperative myocardial ischemia, reduction of ischemic risk may require specific antianginal therapy. Calcium entry blockers are effective drugs in antianginal therapy. Diltiazem reduces myocardial oxygen demand through decreases in heart rate, inotropy, and systolic function, while increasing myocardial oxygen delivery through coronary vasodilation. These potentially beneficial effects of diltiazem were evaluated in 15 of 29 patients (diltiazem v placebo, double-blind study) scheduled for coronary artery bypass graft surgery. Continuous infusion of diltiazem (0.15 mg/kg bolus followed by 2 micrograms/kg/min), during anesthesia and surgery before cardiopulmonary bypass, significantly reduced the major MVO2 determinants during anesthesia with moderate doses of fentanyl and a benzodiazepine (midazolam in 8 of 14 control patients and 9 of 15 treated patients, or flunitrazepam in the others). Heart rate, mean arterial pressure, and inotropy were decreased during the most stressful events of surgery when plasma diltiazem concentrations were in the therapeutic range (greater than 96 ng/mL). The number of patients with perioperative ischemia was 2 of 15 in the treated group and 4 of 14 in the control group. Provided that diltiazem plasma concentrations are sufficient, it can contribute to lowering the ischemic burden during anesthesia for coronary artery surgery.

Hemodynamic effects of anesthesia in patients chronically treated with angiotensin-converting enzyme inhibitors.

Angiotensin-converting enzyme inhibitors (ACEIs) are increasingly used in the treatment of cardiovascular disease, but recent reports have warned of some hemodynamic risk (hypotension and bradycardia) when associated with anesthesia. To assess the hemodynamic effects of induction of anesthesia in patients chronically treated with ACEIs, 16 hypertensive patients scheduled for coronary artery bypass graft surgery (n = 12) or vascular surgery (n = 4) were studied. Eight of them were chronically treated (for at least 1 mo) with ACEIs (ACEI group), and the remaining eight (control group) were treated with other classes of antihypertensive drugs. Induction of anesthesia, which consisted of flunitrazepam (0.03 mg/kg), fentanyl (0.006 mg/kg), and pancuronium (0.1 mg/kg) IV, was followed by a significant decrease in mean arterial blood pressure from baseline in both groups (by 16.8% in controls [P = 0.001] and 33.5% in ACEI-treated patients [P = 0.001] [P = 0.041 between groups]). In control patients, mean arterial blood pressure decrease was only associated with a significant decrease in cardiac index (-18%, P = 0.014). In ACEI-treated patients, the arterial blood pressure decreases were associated with consistent reductions in pulmonary capillary wedge pressure (-26.4%; P = 0.035) and cardiac index (-23.9%; P = 0.001). Systemic vascular resistance index and heart rate were moderately changed (-14.2% and -4.5%, respectively). Rapid restoration of arterial blood pressure was obtained in all ACEI-treated patients, mainly with the intravenous administration of 0.4 to 0.7 L of lactated Ringer's solution. Phenylephrine (0.38 +/- 0.9 mg) was, however, required in four patients when mean arterial blood pressure was less than 60 mm Hg.(ABSTRACT TRUNCATED AT 250 WORDS)

Does choice of the anesthetic influence renal function during infrarenal aortic surgery?

Reconstructive infrarenal aortic surgery is associated with impairment of renal function owing to vasoconstriction during and after aortic cross-clamping. To assess the influence of anesthetic technique on renal hemodynamics during aortic surgery, 34 patients received one of four anesthetics: isoflurane (n = 10), halothane (n = 9), droperidol (n = 8), and flunitrazepam (n = 7). Supplemental anesthesia consisted of midazolam, fentanyl, nitrous oxide in oxygen (50%), and pancuronium. Before aortic cross-clamping, effective renal plasma flow (ERPF) (131iodohippuran clearance) and glomerular filtration rate (GFR) (99technetium-DTPA clearance) were low in the halothane and flunitrazepam groups (118.4 +/- 25.6 and 170 +/- 35 mL/min for ERPF; 19.7 +/- 5.2 and 26.9 +/- 5.8 mL/min for GFR, respectively) and better preserved in the isoflurane group (253.4 +/- 51.5 and 44.9 +/- 8.4 mL/min, respectively; P less than 0.05 between isoflurane and halothane groups) or in the droperidol group as regards GFR (75.4 +/- 9.4 mL/min, P less than 0.05). During clamping, both renal variables were not markedly affected in any group except in the droperidol group in whom GFR significantly decreased from preclamp value. The GFR was then significantly higher in the isoflurane group (49.5 +/- 9.2 mL/min) than in the halothane and flunitrazepam groups (14.8 +/- 3.7 and 26.5 +/- 10.1 mL/min, respectively; P less than 0.05). After aortic declamping, ERPF and GFR increased markedly in the halothane group, and there was no significant difference between the groups. These results suggest that renal hemodynamics are less altered with droperidol-fentanyl anesthesia during abdominal surgery but not during aortic cross-clamping.(ABSTRACT TRUNCATED AT 250 WORDS)

Myocardial depressant effect of nitrous oxide after coronary artery bypass graft surgery.

We have studied the cardiovascular effects of nitrous oxide after cardiac ischaemia-reperfusion injury caused by aortic cross-clamping and unclamping during coronary artery bypass grafting (CABG). At the time of chest closure, 20 patients were allocated randomly to receive oxygen and air (FIO2 = 0.5) or 50% nitrous oxide in oxygen in addition to anaesthesia with fentanyl. Nitrous oxide significantly decreased mean arterial pressure (P less than 0.01) and cardiac index (P less than 0.05), which suggests that nitrous oxide with fentanyl may significantly depress left ventricular performance after CABG. Although ischaemia-reperfusion cardiac injury did not appear to increase the myocardial depressant effect of nitrous oxide, the use of nitrous oxide is not recommended immediately after CABG.

[Pulse oximetry and thoracopulmonary surgery]. / Oxymétrie de pouls et chirurgie thoracopulmonaire.

Arterial blood gases are invasive and they provide intermittent information only. On the other hand, pulse oximetry is non invasive, providing continuous monitoring of SaO2 (SpO2). A study was therefore carried out in twelve patients undergoing lung and intrathoracic surgery to determine whether pulse oximetry was a reliable method of monitoring. The SpO2 values obtained using a Physiocontrol Oximeter (Lifestat 1600) were compared with those given by blood gas measurements (SaO2). When ventilation was switched to one-lung ventilation, PaO2 fell in all cases, whatever the method of monitoring, with PaCO2 remaining constant. 46 paired values of SaO2 were compared using linear regression analysis. Correlation between the two methods was good (r = 0.95; p less than 0.001). Pulse oximetry would therefore seem to provide a reliable method of continuous noninvasive and accurate monitoring of oxygenation during lung surgery.

[Myoglobin: an early indicator of myocardial infarction during heart surgery]. / La myoglobine: un marqueur précoce de l'infarctus myocardique au cours de la chirurgie cardiaque.

Plasma myoglobin was measured in 40 patients before, during and after cardiac surgery under cardiopulmonary bypass, in order to study its value as an indicator of intra-operative myocardial damage. Myoglobin levels rose at cannulation, further increased during the operation and reached a peak 2 hours later; they began to decrease 6 hours after surgery and were back to normal 24 hours later. Myoglobin levels from induction of the anesthetics to the 6th post-operative hour were significantly higher in the 8 patients who developed intra-operative myocardial infarction than in the other patients. Thus, myoglobin is an early indicator of intra-operative myocardial ischaemia. An abnormal rise of myoglobin at induction of the anesthetics characterizes a group of patients at high risk of myocardial infarction during surgery.

[Complement activation in extracorporeal circulation. Comparison of nylon versus polyester bubble oxygenators]. / Activation du complément au cours de la circulation extracorporelle. Comparaison d'oxygénateurs à bulles "nylon" versus "polyester".

Complement activation during cardiopulmonary bypass is well known and may influence postoperative morbidity. As nylon can particularly induce complement activation, its influence was assessed by measuring total haemolytic complement and B, C3 and C4 factors, during cardiopulmonary bypass with bubble oxygenators for coronary surgery, comparing "nylon" circuits (20 patients, Bentley BOS 10) versus "polyester" circuits (19 patients, Shiley S 100 A). Complement activation began with induction of anaesthesia and surgical procedures, B, C3 and C4 levels falling significantly (respectively 15, 17 and 20% from baseline values). The alternative pathway was activated before the classical pathway. Complement activation continued during cardiopulmonary bypass, with no more consumption of complement factors (slight variations of about 0 to 3% of the levels found after anaesthetic induction and surgical procedures). No statistically significant difference appeared between the two groups. This suggested that nylon did not significantly increase complement activation during cardiopulmonary bypass. The bubble oxygenator material cannot therefore be considered as a criterion for choosing the type of equipment.

[Midazolam combined with neuroleptanesthesia as a hypnotic]. / Le midazolam associé à la neuroleptanesthésie comme hypnotique.

Two groups of 20 women randomly distributed underwent general anaesthesia based on dextromoramide and droperidol. Midazolam was given 0.2 mg X kg-1 in the first group, 0.4 mg X kg-1 in the second. Induction was considered satisfactory in more than 90 p. cent of patients in both groups (NS). Midazolam produced a decrease of systolic blood pressure of 9 mm Hg in group I (p less than 0,001) and 11 mm Hg in group II (p less than 0,001) as well as a decrease in diastolic blood pressure of 5 mm Hg (p less than 0,025) and 7 mm Hg (p less than 0,005) respectively. Heart rate decreased significantly only in group II (by 4 c X mn-1, p less than 0,01). These alterations were similar in both groups and did not reach physiologic importance. Maintenance of anesthesia as well as recovery were uneventful in all cases. Higher doses of midazolam reduced only slightly the dose of the neuroleptic. Its is concluded that midazolam is a good induction agent neuroleptic-analgesic anaesthesia. The use of more than 0.2 mg X kg-1 is of no particular interest but is well tolerated.

[Quantitative study of pain in man. Validity of a simple instrument]. / Etude quantitative de la douleur en clinique humaine. Validité d'un appareillage simple.

A generator producing painful stimuli every 20 ms by way of 2 ms square wave electrical impulses was used to study pain quantitatively, and the reliability of the measurements carried out on 24 healthy volunteers. The parameters measured were the levels of detection, pain and tolerance. The results showed that these levels were both stable and reproducible. However, there were very important individual differences.

[Acute hepatic steatosis of pregnancy in an Addisonian patient]. / Stéatose hépatique aiguë gravidique chez une addisonienne.

A case is reported of acute fatty liver occurring in an Addisonian woman with a twin pregnancy. It is pointed out that Sheehan's syndrome or acute fatty liver of pregnancy is an exceptional cause of jaundice in pregnancy. Its severity is due to the syndrome, associating hepatic failure and renal, pancreatic and haemorrhagic complications. The history of the pregnancy and the past medical history are of less import for the outcome. The best treatment is delivery by caesarean section, together with symptomatic treatment of the complications. In case of jaundice of unknown aetiology in late pregnancy, the advantages of an early diagnosis by transjugular hepatic biopsy are discussed.

[Midazolam as an intramuscular premedication agent: definition of posology as a function of age]. / Le midazolam comme agent de prémédication intramusculaire: définition des posologies en fonction de l'âge.

In order to determine the optimal posology of midazolam as an intramuscular premodication according to age, three groups of 25 patients were constituted. The mean age of group 1 receiving 0.12 mg . kg-1, was 31.6 +/- 7.3 years, the mean age of group 2, receiving 0.16 mg . kg-1, was 31.8 +/- 7.6 years and the mean age of group 3, receiving 0.10 mg . kg-1, was 73.8 +/- 8.2 years. The results were the following: sedation of anxiety was good or very good in respectively 80 p. 100 and 95 p. 100 of patients in groups 2 and 3, versus 48 p. 100 in group 1; a reversible sleep was obtained in 18 p. 100 of cases in group 2 and 44 p. 100 in group 3; no patient was asleep in group 1; overall clinical results were found satisfactory in 80 p. 100 of patients in group 2, and 95 p. 100 in group 3 versus 48 p. 100 in group 1. Neither incident nor adverse reactions were to be reported. There was no modification in respiratory rate; the slight hemodynamic modifications which appeared can be attributed to atropine sulfate administered together with midazolam. In conclusion, the appropriate posology of midazolam administered intra-muscularly decreases with age, from 0.16 mg . kg-1 for the thirty years old patients to 0.10 mg . kg-1 for the seventy years old patients. Midazolam exhibits a remarkable cardiorespiratory neutrality event in the elderly.