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Biomedical subjects

M Guiraud

Publications and source records attributed to M Guiraud.

At least 19 recordsLinked to original sources

[The industrial management and the management of surgical units].

Management of operating rooms is moving nowadays. Financial constraints as well as new operating practices prompt the hospital manager to optimise the operating room utilisation. The manufacturing systems faced a similar situation in the early 1980, due to the increase in the cost of the energetic products and the new competitive environment. Manufacturers had to improve dramatically their management capabilities in order to overcome their financial and technical difficulties. If the manufacturing management is extensively developed nowadays, the operating room is still running on an intuitive, individual and manual basis. The purpose of this review is to describe the main features of the manufacturing management and to identify those relevant to the management of operating rooms.

Hospital Administration↗

3-Formyl-1-butyl pyrophosphate A novel mycobacterial metabolite-activating human gammadelta T cells.

Most human blood gammadelta T cells react without major histocompatibility complex restriction to small phosphorylated nonpeptide antigens (phosphoantigens) that are abundantly produced by mycobacteria and several other microbial pathogens. Although isopentenyl pyrophosphate has been identified as a mycobacterial antigen for gammadelta T cells, the structure of several other stimulating compounds with bioactivities around 1000-fold higher than isopentenyl pyrophosphate remains to be elucidated. This paper describes the structural identification of 3-formyl-1-butyl-pyrophosphate as the core of several non-prenyl mycobacterial phosphoantigens bioactive at the nM range. Recognition of this molecule by gammadelta T cells is very selective and relies on its aldehyde and pyrophosphate groups. This novel pyrophosphorylated aldehyde most probably corresponds to a metabolic intermediate of the non-mevalonate pathway of prenyl phosphate biosynthesis in eubacteria and algae. The reactivity to 3-formyl-1-butyl-pyrophosphate supports the view that human gammadelta T cells are physiologically devoted to antimicrobial surveillance.

Antigens, Bacterial↗

Acquisition of a stimulatory activity for Vgamma9/Vdelta2 T cells by a Burkitt's lymphoma cell line without loss of HLA class I expression.

Daudi Burkitt's lymphoma cells activate Vgamma9/Vdelta2 T cells through TCR ligation by an unknown antigen. This activity is for a large part revealed by their lack of HLA class I antigen expression, allowing their escape from KIR downregulation. We characterize here a culture variant of the Burkitt's lymphoma line Raji, RJ-A3, which is able to promote as efficiently as Daudi cells the outgrowth of Vgamma9/Vdelta2 T cells in cocultures in spite of unchanged HLA class Ia/Ib antigen expression. RJ-A3 is resistant to lysis by most Vgamma9/Vdelta2 lines and clones, even those lacking CD9-4/NKG2 and p58, p70 p140 KIR molecules. However, one Vgamma9/Vdelta2 line which can efficiently kill RJ-A3 do so in a TCR-dependent manner since killing is modulated by anti-TCR antibodies. The CDR3 sequences of the T cell clones amplified with Daudi and RJ-A3 reveal that some clones can be expanded with both lines while others are expanded preferentially with one or the other but not both. This indicates differences in the antigenic determinants of the two Burkitt's lines. The occurrence of this Raji variant line demonstrates that the stimulatory phenotype for Vgamma9/Vdelta2 cells can be acquired by some tumors independently of the loss of class I antigens and comforts the hypothesis of an anti-tumoral function for the Vgamma9/Vdelta2 T cell population.

Burkitt Lymphoma↗

Medium- and long-chain triacylglycerols in postoperative patients: structured lipids versus a physical mixture.

Forty patients, scheduled for abdominal surgery, were randomized to receive postoperatively either a structured or a physical mixture of long-chain triacylglycerols/medium-chain triacylglycerols (LCT/MCT) emulsions to assess the tolerance and the effectiveness of the structured triacylglycerol emulsion. Total parenteral nutrition started the day after surgery and covered 100% of measured energy expenditure with nitrogen (0.2 g N.kg-1.d-1) and non-protein calories: glucose (50%) and lipids (50%). Blood samples for liver function tests, albumin, transthyretin, and triacylglycerols were checked at 0800 h on the day before surgery and on day 1, day 3, and day 6 after surgery. Urine samples were taken each day from day 1 to day 7 for 3-methylhistidine (3 Me His) and total nitrogen measurements. Aspartate transaminase (ASAT), alanine transaminase (ALAT), and triacylglycerol plasma levels in routine clinical biochemistry increased significantly in the physical mixture group. Nitrogen balance and 3 Me His excretion were not significantly different between groups. Structured triacylglycerol (STG) lipid emulsions are as efficacious as the physical mixture on nitrogen balance in postoperative patients. They could have some advantages: no disturbances were found to occur in liver function tests or plasma triacylglycerol levels.

Aged↗

Influence of body compartments on propofol induction dose in female patients.

BACKGROUND: For induction of anaesthesia, drugs such as propofol are commonly administered according to a per weight basis. However, drugs are primarily distributed to the fat-free mass. This study was undertaken to determine the relationship between propofol requirement for induction and body mass determined by bioimpedance analysis (BIA) or by body mass index (BMI). METHODS: Twenty-one ASA 1 female patients scheduled for gynaecologic surgery received propofol for induction at 133 mg.min-1. Stepwise regression analysis was used to describe the relationships between propofol requirement for loss of consciousness and age, body weight, and lean body mass measured by BIA and BMI (independent variables). RESULTS: Loss of consciousness was obtained with a propofol dose (Mean (SEM)) of 2.17 +/- 0.10 mg.kg-1. Stepwise analysis showed that propofol requirement (total dose) was not proportional to weight or age but related to lean body mass as determined by BIA and to body mass index (r2 = 0.447; global P- value < 0.007). BMI was the only regressor variable when the propofol dose was expressed in mg.kg-1 (r2 = 0.661; P < 0.001). CONCLUSIONS: Our results indicate that propofol requirements for induction are proportional to the lean body mass rather than total body weight.

Adult↗

Promiscuous and specific binding of HIV peptides to HLA-DR1 and DR103. Impact on T-cell repertoire of nonimmunized individuals.

The binding of immunogenic peptides to DR molecules is influenced by residues that point into the peptide-binding groove. The T-cell response toward a peptide complexed to an MHC molecule depends on the presence of a sufficient number of T cells reactive with peptide-MHC complex on the surface of APCs. From 96 overlapping HIV peptides, we have selected 11 that show a significant binding to either DR1, DR103, or both. These two DR molecules are identical except for three amino acids at positions 67, 70, and 71 on the beta chain. Peptide-specific T-cell lines and clones were generated with cells from nonimmunized donors homozygous for DR1 or DR103 by using either individual peptides or peptide pools for the in vitro priming. Three of the peptides induced T-cell-specific proliferative response in both individuals, and these peptides were not among those with highest affinity. Most of the peptides induced strong responses against autologous APCs. This might reflect cross-reactivity between HIV and self-peptides. Definition of peptides that both show promiscuous binding to DR and elicit a strong T-cell response is important for design of efficient synthetic vaccines.

AIDS Vaccines↗

Effects of intravenous medium-chain triglycerides on pulmonary gas exchanges in mechanically ventilated patients.

OBJECTIVE: In mechanically ventilated patients, pulmonary gas exchange was investigated during the administration of total parenteral nutrition containing medium-chain triglycerides or long-chain triglycerides as fat emulsions. DESIGN: Prospective, randomized, crossover trial (two lipid infusion periods of 8 hrs). SETTING: Intensive care unit in a university hospital. PATIENTS: Six mechanically ventilated patients, using the pressure-support mode. INTERVENTIONS: Total caloric intake was adapted according to measured energy expenditure. Fat emulsion provided 50% of the energy expenditure. Patients were infused with 50% medium-chain/50% long-chain triglycerides or 100% long-chain triglycerides in a random sequence. MEASUREMENTS AND MAIN RESULTS: Oxygen consumption, CO2 production, and minute ventilation were measured by indirect calorimetry. PaO2 and PaCO2 were determined in blood samples. Medium-chain triglycerides increased oxygen consumption by 27.8% and minute ventilation by 14.3% at the end of the protocol. CO2 production, PaO2, and PaCO2 were not different between groups. CONCLUSIONS: Medium-chain triglycerides cause an increase in metabolic demand in mechanically ventilated patients when they are infused over a short period. Postoperative or intensive care unit patients with a low pulmonary reserve should receive infusions of medium-chain triglycerides over a more prolonged period than long-chain triglycerides.

Aged↗

Metabolic effects of a D-beta-hydroxybutyrate infusion in septic patients: inhibition of lipolysis and glucose production but not leucine oxidation.

OBJECTIVE: To study the effect of a D-beta-hydroxybutyrate infusion on protein metabolism, lipolysis, and endogenous glucose production in septic patients. DESIGN: Prospective, randomized trial. SETTING: Intensive care unit (ICU) and metabolic unit at a university hospital. PATIENTS: Twelve ICU patients with sepsis and six healthy normal subjects. INTERVENTIONS: Septic patients were administered 4-hr infusions of either D-beta-hydroxybutyrate or a control solution, 12 hrs after parenteral nutrition was replaced with an isotonic saline infusion. MEASUREMENTS AND MAIN RESULTS: The appearance and oxidation rates of leucine (L[1-13C]leucine) and endogenous glucose production (D[6,6-2H2]glucose), plasma fatty acids, and glycerol values were measured before and at the end of infusion of D-beta-hydroxybutyrate or control solution. Unlike the control test, the D-beta-hydroxybutyrate infusion decreased glucose production, fatty acids, and glycerol concentrations, but failed to decrease the leucine oxidation rate. CONCLUSION: Exogenous ketone-bodies infusion decreased lipolysis and glucose production in septic patients but had no beneficial effect on protein metabolism, as evaluated with L[1-13C]leucine.

3-Hydroxybutyric Acid↗

Catheter fracture and embolisation in a totally implanted venous access catheter (TIVAC) following shoulder trauma.

A totally implanted intravenous catheter (TIVAC) was placed via the subclavian vein in a 32-year-old male patient with HIV infection for intermittent drug therapy. 8 months after insertion, a catheter fracture was noted with embolisation of the distal part into the heart. This accident was related to shoulder trauma with a downward movement of the clavicle. In active patients alternatives to the subclavian approach for TIVAC need to be considered.

Journal Article↗

[Acute respiratory insufficiency caused by diffuse pulmonary hemorrhage].

Two cases of adult respiratory distress syndrome due to diffuse pulmonary haemorrhage are reported. The first patient was treated with azathioprine, prednisolone, cyclosporine and ranitidine for haemorrhagic rectocolitis; the second has untreated primary biliary cirrhosis. Haemoptysis only occurred in the latter. Both had severe isolated hypoxaemia. Chest X-rays revealed bilateral alveolar infiltrates. Bronchoscopies showed a diffusely bleeding bronchial tree. Both patients recovered after having been mechanically ventilated with positive end-expiratory pressure for six and eight days respectively. The cause of the diffuse pulmonary haemorrhage was, in the first case, severe thrombocytopaenia (17,000 G.1-1) of central origin, and, in the other patient, an unspecified vasculitis. Diffuse pulmonary haemorrhage should be added to the list of possible causes of the adult respiratory distress syndrome.

Adult↗

HIV-2 and HIV-1 AIDS cases in Senegal: clinical patterns and immunological perturbations.

The serological and immunological parameters, disease patterns, and social characteristics of 39 human immunodeficiency virus type 2 (HIV-2) seropositive CDCIV cases seen in Dakar, Senegal were studied. These data were compared with those obtained from 48 HIV-1 seropositive CDC stage IV patients. Social characteristics of populations infected with HIV-1 or HIV-2 were clearly different. A patient sex ratio of three men to one woman was found for both viruses. In addition, the immune status of nonsymptomatic HIV-1 and HIV-2 seropositive people was evaluated. The correlation between abnormalities of the immune system and clinical status was similar for the two infections. Clinical symptoms of both diseases were the same, but this cross-sectional study could not address the questions of differences between the two infections in latency and development of disease or specific manifestations of HIV-2 infection. This study suggests that HIV-2 infection may contribute to the present AIDS epidemic in West Africa.

Acquired Immunodeficiency Syndrome↗

Relationship between preoperative amiodarone treatment and complications observed during anaesthesia for valvular cardiac surgery.

Two groups of ASA physical status class III and IV patients undergoing cardiac surgery were reviewed in an attempt to obtain more conclusive data concerning dangerous interactions between amiodarone and anaesthesia. The amiodarone group (Group 1, ten patients, cumulative dose 10 g) was compared with a control group (nine patients, Group 2). Amiodarone (A) and desethylamiodarone (NA) concentrations in plasma and myocardium were measured and haemodynamic and antiarrhythmic effects were analysed. Throughout anaesthesia haemodynamic status was similar in both groups. No correlation was found between A/NA and cardiac index changes. No patients needed intraaortic blood pressure augmentation or developed low systemic vascular resistances. Pacemaker dependency was similar in both groups and there was no evidence of increased anaesthetic risk. An excellent antiarrhythmic effect was obtained during the postoperative period. We conclude that preoperative treatment with amiodarone is effective against postoperative arrhythmias.

Adult↗

Auditory evoked potentials during propofol anaesthesia in man.

The effects of propofol on auditory evoked potentials were studied in nine patients undergoing otorhinolaryngology surgery. After recording of basal evoked potentials patients received propofol 2 mg kg-1 over 2-3 min for induction of anaesthesia. Potentials were recorded every 10 min (T1, T2, T3). During T1, T2, T3, the infusion rates of propofol for maintenance of anaesthesia were respectively 7, 5 and 3 mg kg-1 h-1 consecutively. Middle latency component was affected markedly. Brainstem waves latencies I, III, V were increased significantly, while amplitude waves I, III, V remained constant.

Adult↗

Regulation of ketone body flux in septic patients.

To assess the effect of sepsis on ketone body (KB) kinetics in humans, we measured in normal and septic subjects KB appearance rate (Ra) before (initial state) and during a rise of free fatty acids (FFA) level (intravenous infusion of a triglycerides emulsion). We studied normal subjects in postabsorptive state and septic patients when receiving an hypocaloric intravenous infusion of glucose and amino acids or 12 h after its interruption. When receiving glucose and amino acids infusion, septic patients had higher glucose and insulin levels than normal subjects, and despite lower FFA concentrations (255 +/- 44 vs. 480 +/- 51 mumol/l, P less than 0.05) comparable initial KB Ra (2.50 +/- 0.10 vs. 2.48 +/- 0.30 mumol.kg-1.min-1). Triglyceride infusion increased FFA to comparable values (septic 780 +/- 130, normal 730 +/- 45 mumol/l), but KB Ra rose in septic patients only to 3.7 +/- 1.1 instead of 7.7 +/- 1.1 mumol.kg-1.min-1 as in normal subjects (P less than 0.05). Somatostatin infusion decreased the hyperinsulinemia of septic patients but did not restore a normal ketogenesis. After interruption of nutriment infusion, septic patients had normal FFA levels and only mild hyperglycemia and hyperinsulinemia. Their initial KB Ra was not modified. However, their response of KB Ra (increase to 6.27 +/- 2.0 mumol.kg-1.min-1) to raised FFA levels (842 +/- 170 mumol/l) was comparable to the response of normal subjects. In conclusion, although septic patients receiving an hypocaloric parenteral nutrition had a depressed ketogenesis they were able to restore a normal ketogenic capacity after a short-time caloric deprivation. Glucose and/or insulin appears to have a major role in this modulation of hepatic ketogenesis.

Adult↗

Nitrogen-sparing effect of epidural administration of local anesthetics in colon surgery.

A nitrogen-sparing effect of epidural anesthesia has been clearly demonstrated in gynecological and lower abdominal surgery. To determine if epidural anesthesia also has a protein-sparing effect during major upper or mid-abdominal surgery, postoperative nitrogen balance and 3-methylhistidine urinary excretion (an index of skeletal muscle protein catabolism) were measured for 6 days in 28 patients who had undergone colon resection for cancer with general anesthesia (N2O-O2-1% enflurane) either supplemented with low dose fentanyl plus intermittent systemic pentazocine for postoperative pain (n = 13), or the same general anesthetic plus epidural injection of either etidocaine 1% intraoperatively and bupivacaine 0.25% postoperatively (n = 8) or meperidine (n = 7) for 48 hr after skin incision. The cumulative 6-day nitrogen balance and the cumulative 3-methylhistidine urinary excretion were significantly less after epidural injection of etidocaine intraoperatively and bupivacaine postoperatively than in the two other groups. There was a significant correlation between the daily urinary excretion of 3-methylhistidine and the daily nitrogen balance in the three groups. This study suggests that in colon surgery, epidural analgesia with local anesthetics in the postoperative period improves nitrogen balance and this effect takes place partly in the muscle.

Aged↗