Biomedical subjects

M Lamy

Publications and source records attributed to M Lamy.

At least 145 records · Page 8Linked to original sources

PubMed1993

Epstein-Barr virus serology and Epstein-Barr virus-associated lymphoproliferative disorders in pediatric liver transplant recipients.

Epstein-Barr virus serology was performed before and after transplantation in 116 patients of a total series of 261 pediatric OLT recipients. Thirty-nine percent had no immunity before OLT, but this percentage decreased to 11.2% at 6 months and 10.5% at 2 years after transplantation. In this series, 10 children developed a B cell lymphoproliferative disease. Four had adenotonsillar involvement, 2 of them with associated digestive tract invasion. Three of these are alive, 2 after retransplantation for chronic rejection subsequent to arrest of immunosuppression. The fourth died from bone marrow aplasia. Three patients with multiorgan involvement died from multisystemic failure. The remaining 3 patients had a pseudotumoral mass. Two of these are alive, 1 after retransplantation for hepatic localization and secondary vascular and biliary complication. The last died from cachexia. Four patients developed the syndrome after viral reactivation, and 6 after primo infection. Four patients were under FK506 rescue therapy. We conclude that a high rate of EBV primo infection is observed in the first months after transplantation. A significant percentage will develop EBV-associated lymphoproliferative disease, which causes death in half of the patients, including all these with multiorgan involvement. Half of the patients may survive, but because immunosuppression must be stopped, retransplantation for chronic rejection is often necessary in survivors.

Adolescent↗

PubMed1993

Circulatory and respiratory effects of the combination medetomidine-ketamine in beagles.

The cardiovascular and respiratory parameters of eight laboratory beagles were measured before and after the simultaneous injection of medetomidine (40 micrograms/kg bw) and ketamine (5 mg/bg bw). This combination produced a significant alteration in cardiovascular function. The heart rate, the stroke volume and cardiac output decreased while the systemic vascular resistance increased. These effects were attributed principally to the alpha 2 agonist compound combined with the moderate stimulatory effect of ketamine. The respiratory parameters were little affected by this protocol.

Adrenergic alpha-Agonists↗

PubMed1993

Comparative evaluation of three heat and moisture exchangers during short-term postoperative mechanical ventilation.

This study compared performance of three heat and moisture exchangers (HME) during short-term postoperative mechanical ventilation. Temperature and absolute humidity (AH) were measured at various points of the ventilatory circuit. There was no statistical difference between the groups, regarding ambient and body To, body weight, fraction of inspired oxygen, tidal volume, and respiratory rate. Only the hygroscopic HME (groups 2 and 3) provide adequate conditioning with regard to AH and To of the inspiratory gases. The performance of hydrophobic HME (group 1) was inferior and appears to be unsatisfactory. Indirect evaluation (variations of inspiratory gases and tracheal temperatures, AH of the expired gases) confirmed the superiority of the hygroscopic HME. These data suggest that humidification of inspiratory gases with a hygroscopic HME is a defensible practice during short-term postoperative mechanical ventilation. Performance of hydrophobic HME may be weak and can expose the patient to an unacceptable risk of endotracheal tube occlusion.

Body Temperature↗

PubMed1993

Laryngeal mask.

The laryngeal mask, provides a totally patent airway when positioned in the hypopharynx with remarkable patient tolerance, even at very light planes of sedation. The major advantages of the laryngeal mask are its ease of insertion, the absence of contact with the vocal cards, and the fact that it frees the hands of the anesthesiologist. Contraindications to its use result from its failure to seal the airway against regurgitation of gastric content. Laryngeal masks can be used easily instead of facial masks during anesthesia with spontaneous ventilation and, with experience, can be used for longer procedures using controlled ventilation. Suspected difficult intubation and establishment of a patent airway in emergency conditions are good indications for the use of this device. The laryngeal mask does not replace endotracheal intubation. It can, however, permit better management of the airway while waiting for personnel trained in endotracheal intubation. The nature of the pulmonary pathology seen in intensive care patients limits use of the laryngeal mask during intensive care. In the operating room few complications have been described, and postoperative discomfort is minimal. The laryngeal mask is a device positioned in the hypopharynx which allows separation of the digestive tract from the airway, without violation of either the larynx or the upper oesophageal sphincter. An endotracheal tube, because of its positioning, hinders normal glottic movement and narrows the airway.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, Inhalation↗

PubMed1993

In vivo free radical production after cross-clamping and reperfusion of the renal artery in the rabbit.

Postischaemic reperfusion injury is often attributed to the generation of oxygenated free radicals which may subsequently promote lipid peroxidation in cell membranes. Electron paramagnetic resonance spectroscopy in association with the spin trap molecule alpha-phenyl-N-tert-butyl-nitrone allowed direct confirmation of lipid free radical production after renal ischaemia-reperfusion in an in vivo rabbit model. A 60-min period of ischaemia followed by reperfusion caused free radical production twofold greater than after 15 min of ischaemia. Glutathione and alpha-tocopherol have been measured in renal tissue, as indirect markers of lipid peroxidation. After 15 min of ischaemia followed by 10 min of reperfusion, the mean(s.e.m.) glutathione content of the ischaemic kidney was slightly but significantly reduced by 11.9(2.5)% (P < 0.003). The content of alpha-tocopherol was unchanged. However, 10 min of reperfusion following 60 min of ischaemia led to significant decrease in mean(s.e.m.) content of both glutathione (30.4(3.7)%) (2.23(0.2) versus 3.14(0.18) mumol/g wet tissue, P < 0.001) and alpha-tocopherol (46.1(7.8)%) (0.57(0.10) versus 1.09(0.14) micrograms/g wet tissue, P < 0.001) when compared to the control kidney. Under these experimental conditions, desferrioxamine (15 mg/kg administered intravenously before inducing ischaemia), a drug known to limit free radical production, significantly limited the decrease of alpha-tocopherol to 20.8(6.4)% (0.83(0.08) versus 1.05(0.04) micrograms/g wet tissue, P < 0.05), but did not prevent glutathione consumption in the reperfused kidney.

Animals↗

PubMed1993

Monoamine oxidase inhibitors and anesthesia: an updated literature review.

Safe anesthesia for patients taking MAOIs has been possible since the 1980s using judicious choice of agents. The introduction of a new class of MAOIs (RIMA) has increased the margin of safety for these anesthetics. These drugs allow selective and rapidly reversible inhibition of type A-MAO. The pharmacologic effects of this new class of drug as well as their potential interactions with agents used in anesthesia are reviewed.

Anesthesia↗

PubMed1993

Total intravenous anesthesia in South-African genetic porphyria (variegate porphyria).

The authors report the case of a female patient with South-African genetic porphyria who had to undergo hepatic tumorectomy under general anesthesia. The choice for propofol as the induction and maintenance agent using a balanced anesthetic technique led to a significant rise in urinary excretion of porphyrins without associated clinical manifestations. A short review of the literature on physiopathology of porphyrias and medicinal agents, susceptible to induce acute porphyric crisis follows. The authors conclude that the innocuity of propofol as induction and maintaining agent in the porphyric patient cannot be yet established without further studies.

Adult↗

PubMed1992

Acute adenovirus hepatitis in liver transplant recipients.

An acute or fulminant adenovirus hepatitis developed in 5 of 224 pediatric patients who were recipients of orthotopic liver transplants. All had received prednisolone, azathioprine, and cyclosporine as basal immunosuppression, and four received monoclonal (OKT3) or polyclonal (antithymocyte globulin) antibodies for steroid-resistant rejection episodes. These patients initially had high fever and a worsening condition for a mean of 73 days after transplantation (range 44 to 140 days). Results of biochemical tests showed very high serum levels of lactate dehydrogenase. Aspartate aminotransferase values were always markedly more elevated than those of alanine aminotransferase. Two patients had severe leukopenia. Results of histologic studies of the liver showed extensive areas of confluent necrosis and targetlike hepatocyte nuclei. Typical intranuclear viral inclusions were observed on electron microscopy. Adenovirus was cultured in all patients and in two relatives. Two patients died of liver failure; others recovered after cessation of immunosuppression. We conclude that adenovirus hepatitis can be fatal in liver transplant recipients. There is no specific treatment, and immunosuppression must be discontinued.

Adenovirus Infections, Human↗

PubMed1992

Plasma levels of polymorphonuclear elastase and myeloperoxidase after uphill walking and downhill running at similar energy cost.

This study was designed to compare the effects of eccentric and concentric exercises on blood polymorphonuclear neutrophil count (nPMN) and plasma levels of myeloperoxidase ([MPO]) and elastase ([EL]) used as markers of neutrophil (PMN) activation. Ten healthy male subjects underwent 2 periods of exercise of 20 min duration each at 60% VO2max on an inclined treadmill. They initially walked up a 5% grade (UW). Ten days later they ran downhill on a 20% grade (RD). Blood samples were collected 10 min before and immediately after exercise. A postexercise sample was drawn after 20 min recovery. Both exercise bouts were accompanied by a similar and significant (p < 0.01) increase of 33% in nPMN above resting values. Baseline nPMN values were reached after 20 min recovery. There were no significant changes in [MPO] and [EL] following UW. In contrast, RD was followed by significant increases (p < 0.001) in [MPO] (+97%) and [EL] (+70%) above resting levels. While [MPO] returned to its pre-exercise level after 20 min recovery, [EL] remained significantly elevated (p < 0.05). These results clearly demonstrate the importance of the eccentric component of muscle contraction in exercise-induced PMN activation.

Adolescent↗

PubMed1992

Metabolic and respiratory changes after cholecystectomy performed via laparotomy or laparoscopy.

We have compared metabolic and respiratory changes after laparoscopic cholecystectomy (n = 15) with those after open cholecystectomy (n = 15). The durations of postoperative i.v. therapy, fasting and hospital stay were significantly shorter in the laparoscopy group. During the first and second days after operation, analgesic consumption but not pain scores (visual analogue scale) were significantly smaller after laparoscopy, while vital capacity, forced expiratory volume in 1 s, and PaO2 were significantly greater. The metabolic and acute phase responses (glucose, leucocytosis, C-reactive protein) were less after laparoscopy compared with laparotomy. Although plasma cortisol and catecholamine concentrations were not significantly different between the two groups, after surgery interleukin-6 concentrations were less in the laparoscopy group.

Acute-Phase Reaction↗

PubMed1992

Cytokine serum level during severe sepsis in human IL-6 as a marker of severity.

Forty critically ill surgical patients with documented infections were studied during their stay in an intensive care unit. Among these patients, 19 developed septic shock and 16 died, 9 of them from septic shock. Interleukin 1 beta (IL-1 beta), tumor necrosis factor (TNF alpha), and interleukin 6 (IL-6) were measured each day and every 1 or 2 hours when septic shock occurred. Although IL-1 beta was never found, TNF alpha was most often observed in the serum at a level under 100 pg/mL except during septic shock. During these acute episodes TNF alpha level reached several hundred pg/mL, but only for a few hours. In contrast, IL-6 was always increased in the serum of acutely ill patients (peak to 500,000 pg/mL). There was a direct correlation between IL-6 peak serum level and TNF alpha peak serum level during septic shock and between IL-6 serum level and temperature or C-reactive protein serum level. Moreover, IL-6 correlated well with APACHE II score, and the mortality rate increased significantly in the group of patients who presented with IL-6 serum level above 1000 pg/mL. Thus, IL-6 appears to be a good marker of severity during bacterial infection.

Adult↗

PubMed1992

Plasma myeloperoxidase and vitamin E levels in head injury: preliminary results related to outcome.

This preliminary study was designed to assess a possible role of neutrophil activation and to determine the prognostic value of plasma myeloperoxidase (MPO) and vitamin E (Vit. E) levels in severe head injury. Plasma MPO and Vit. E levels were measured in nine severely head-injured patients (Glasgow Coma Score </=8) (ages 12-80 years) 6, 12. 18, 24, and 30 h after trauma. Patients were classified into two groups according to outcome after discharge from the ICU: group D (death; n = 5) and group S (survival; n = 4). Plasma MPO levels were increased immediately after trauma and then decreased. The MPO peak observed after 6 h was significantly higher (p < 0.05) in group D (mean +/- SEM: 1,237 +/- 122 ng/ml) than in group S (mean +/- SEM: 543 +/- 148 ng/ml). Plasma Vit. E levels were lower than normal values and decreased over time. They were always significantly lower (p < 0.05) in group D than in group S, except for the first sample. These differences cannot be explained entirely by total plasma lipid (TL) values since no statistical difference in TL concentrations was found between the two groups during the course of study. The ratio of Vit. E to TL. considered as the best index of Vit. E status, was lower in group D than in group S. and the difference reached statistical significance (p < 0.05) 12 h after trauma. In conclusion, in spite of the limited number of patients included in this study, it appears that severe head injury is associated with an increase in MPO and a decrease in Vit. E levels. These biochemical changes are of greater magnitude in group D than in group S; they suggest neutrophil activation and lipoperoxidation processes. Finally, plasma MPO and Vit. E seem to be new discriminant factors of outcome in head-injured patients.

Journal Article↗

PubMed1992

[Cytomegalovirus and the fetus].

The literature on the risks to the fetus and neonate of maternal cytomegalovirus infection, whether primary or reactivated, is briefly reviewed. The various rates of risks reported and the mechanism of fetal infection are discussed. Screening for maternal infection, antenatal diagnosis of fetal infection, and development of new antiviral treatments and immunizations are advocated.

Cytomegalovirus Infections↗

PubMed1991

Self-labeling of human polymorphonuclear leucocyte myeloperoxidase with 125iodine.

In order to obtain a radioimmunoassay (RIA) technique for the measurement of human plasma myeloperoxidase (MPO), we purified the enzyme from polymorphonuclear granulocytes (neutrophils), and compared three methods of labeling it with 125Iodine:chloramine T, lactoperoxidase, and an original technique of 'self labeling' based on the ability of the enzyme to oxidize and bind 125I in the presence of H2O2. The chloramine T technique produced a degraded protein, as well shown by a high non-specific binding of tracer to antibody. The lactoperoxidase technique did not succeed in labeling MPO with an adequate specific activity. In contrast, the self-labeling method gave a stable tracer with a specific activity of 23 microCi/micrograms MPO (85 MBq), a satisfactory level of immunoreactivity, and a low-specific binding (less than or equal to 3%). After labeling, purification of tracer was achieved by gel filtration chromatography in phosphate buffer (0.05 M; pH7) to which 0.1% poly-L-lysine was added. The labeled molecule remained stable for 40 days and could be used for RIA with a polyclonal antibody raised in rabbits.

Chloramines↗

PubMed1991

Fast double antibody radioimmunoassay of human granulocyte myeloperoxidase and its application to plasma.

The haem enzyme myeloperoxidase (MPO) (EC 1.11.1.7) with a spectral A430/A280 ratio greater than 0.7 and a specific activity of 125 U/mg was purified from isolated human neutrophils. To obtain a radioimmunoassay (RIA) for this enzyme, a specific antiserum against human neutrophil MPO was raised in rabbits and used at an initial dilution of 1/10,000. MPO labelled with 125iodine by a technique of self-labelling in the presence of H2O2, had a specific activity of 24 mCi/mg. After incubation at room temperature (2 h) and separation by double antibody precipitation in the presence of polyethylene glycol, the sensitivity of the RIA was 21 ng/ml. The RIA showed good precision and accuracy with intra- and interassay coefficients of variation of less than 7% for MPO concentrations ranging from 100 to 800 ng/ml, and satisfactory recoveries of known amounts of exogenous MPO in plasma. For the measurement of MPO in blood, the best sampling technique was to collect blood into EDTA. Rapid centrifugation (within 20 min) was necessary for blood collected into heparin. Mean MPO values in normal individuals were 340 +/- 98 ng/ml in EDTA plasma (n = 152) and 332 +/- 82 ng/ml in heparinized plasma (n = 34). When MPO was measured 12-6 h after injury in critically ill patients high values (above 1000 ng/ml) were found in 6/15 patients with multiple injuries. In patients with sepsis (n = 22), MPO values were always above 1000 ng/ml.

Animals↗

PubMed1991

Clinical and serological studies in a series of 45 patients with Guillain-Barré syndrome.

We retrospectively reviewed the clinical files of 45 Guillain-Barré syndrome (GBS) patients admitted to our Department between 1979 and 1989. The age distribution was bimodal with a first peak in young adults (20-40 years), and a second one between 60 to 70 years. Seasonal distribution showed a late fall and a hivernal predominance. Three patients experienced a second attack of GBS 2-9 years after the first one. Thirty-one (69%) presented antecedent events, most often a respiratory tract infection (n = 20) or enteritis (n = 6). Serological studies were systematically performed, including antibody titers against herpes simplex virus, Epstein-Barr virus, cytomegalovirus (CMV), respiratory syncytial virus, human immunodeficiency virus, Mycoplasma pneumoniae, Campylobacter jejuni/coli and cardiolipin. These studies showed the presence of antibodies indicative of a CMV primary infection in 22% cases and of a Campylobacter jejuni/coli infection in 13%. Co-infection was observed in 3 cases. Serology remained negative in 12 patients with a preceding respiratory infection. There was no correlation between serology and the severity of the disease. Absence of antecedent events and of positive anti-infectious serology was observed in only 10 patients.

Adult↗

PubMed1991

Plasma vitamin E, total lipids and myeloperoxidase levels during spinal surgery. A comparison between two anesthetic agents: propofol and isoflurane.

Plasma levels of vitamin E (Vit. E), total lipids (TL), Vit. E to TL ratio and myeloperoxidase (MPO) were studied in 20 patients undergoing lumbar spinal surgery and randomly allocated to two anesthetic groups: propofol (bolus dose + continuous infusion and thiopental/isoflurane. Peripheral blood samples were withdrawn prior to induction, each hour during anesthesia and 1 h after the end of surgery. Mean Vit. E and TL levels as well as mean Vit. E to TL ratios remained in the normal range over the entire period of study whatever the anesthetic regimen. MPO levels rose significantly in the post-operative period only, but without statistical difference between the two groups. Therefore, anesthesia with propofol or thiopental/isoflurane modifies neither total lipid concentrations nor plasma Vit. E, which is a potent endogenous inhibitor of lipid peroxidation bound to lipoproteins. The rise of plasma MPO suggests a moderate post-operative neutrophil activation which is not influenced by anesthetic techniques.

Adult↗

PubMed1991

[Mobilization of leukocytes during sub-maximal dynamic exercise].

Increase of blood leucocytes induced by a dynamic exercise has been studied in 10 adult male subjects (age: 22 +/- 2 years; body weight 73 +/- 10 kg; VO2max: 54 +/- 8 ml O2/kg.min. The exercise consisted of a 20 minutes test on a cycle ergometer at a work rate eliciting a total energy expenditure roughly equal to 80% of the maximal aerobic power (80% VO2max). During exercise the absolute number of circulating leucocytes (n Leu) increased significantly toward a maximal value reached in most cases at the end of exercise. The maximal values of n Leu--expressed as percentage of n Leu measured at rest--in the different blood leucocyte types (monocytes:n Mono; granulocytes:n GR; natural killer cells:n NK) and lymphocyte subsets (lymphocytes:n LY; lymphocytes T:n T; lymphocytes B:n B; lymphocytes T helper:n T4; lymphocytes T suppressor:n T8)--were as follows:n Mono:240%; n GR:170%; n NK:490%; n LY:220%; n T:200%; n B:190%; n T4:140%; n T8:190%. With the exception of n GR, n Leu decreased during recovery at a rate depending on the leucocyte type. The n T4/n T8 ratio, equal to 1 at rest, was reduced by about 40% during exercise. This ratio rose after exercise and reached a value equal to that measured at rest after 20 minutes recovery. In agreement with FERRY (1989), we concluded that exercise is accompanied by a selective mobilization of the different leucocyte types. The magnitude of this phenomenon and the kinetics of n Leu recuperation depend on cell types.

Adult↗