Biomedical subjects

F Gouin

Publications and source records attributed to F Gouin.

At least 73 records · Page 4Linked to original sources

PubMed1997

Membrane fluidity and oxygen diffusion in cholesterol-enriched erythrocyte membrane.

This work studied the effect of cholesteryl hemisuccinate incorporation on membrane fluidity and on the kinetics of oxygen diffusion at different depths in the erythrocyte membrane. Cholesterol concentration in the membrane was expressed as the cholesterol-protein ratio (C/Pt). The membrane fluidity, as assessed by a fluorescence polarization method with diphenyl-hexatriene and 1-(4-trimethylamino)-6-phenylhexa-1,3,5-triene, decreased as the C/Pt ratio increased. Time-resolved fluorescence spectroscopy of pyrene dodecanoic acid (PDA) under an increasing C/Pt ratio in the erythrocyte membrane revealed enhanced oxygen diffusion in the middle of the membrane bilayer (in which PDA was incorporated), which was not the case with pyrene butyric acid (PBA) incorporated in the internal part of the membrane surface. It has generally been accepted that increased membrane fluidity reduces the physical barrier to oxygen permeation. Such conflicting observations on oxygen permeation in the rigidified erythrocyte membrane could be due to variations in oxygen solubility (preferential partitioning) in different polarity microdomains (cholesterol and phospholipid partitions).

Cholesterol↗

PubMed1997

Relationship of microbiologic diagnostic criteria to morbidity and mortality in patients with ventilator-associated pneumonia.

OBJECTIVE: To evaluate whether the mortality and the morbidity of ventilator-associated pneumonia, defined by positive result of protected specimen brush culture, was different from that defined by other methods. DESIGN: Matched-cohort study. All patients with clinical suspicion of pneumonia were investigated with protected specimen brush, bronchoalveolar lavage, and blind bronchial samplings. Two groups were defined: brush-positive patients (positive culture of the protected specimen brush) and brush-negative patients (negative culture of the protected specimen brush, but positive culture with another method). SETTING: A 14-bed medicosurgical intensive care unit (ICU) in an 850-bed teaching hospital. PATIENTS: All patients with documented ventilator-associated pneumonia over 4 years 9 months. A total of 102 cases documented by protected specimen brush culture and 223 documented by another sampling procedure. Patients were matched according to diagnosis on admission, age, sex, date of admission, Acute Physiology and Chronic Health Evaluation II (APACHE II) score, and date of onset of pneumonia. MAIN OUTCOME MEASURES: Mortality rate, duration of mechanical ventilation, duration of ICU stay, duration of hospital stay, sampling methods, and microbiologic cultures. RESULTS: A total of 76 pairs were submitted for analysis. The effectiveness of matching was 81.85%. There was no difference in mortality between brush-positive patients and brush-negative patients. The ICU fatality rate was 38% in the brush-positive group and 39.4% in the brush-negative group (odds ratio [OR], 0.95; 95% confidence interval [CI], 0.46-1.93). The hospital fatality rate was 41% (OR, 1; 95% CI, 0.5-2.01). The mean (SD) duration of ventilation was 26 (23) days in the 2 groups (range, 3-132 days). The duration of ICU stay was 33 (27.4) days in the 2 groups (range, 3-152 days). CONCLUSIONS: When confounding factors are controlled, patient outcome is the same if ventilator-associated pneumonia has been diagnosed by protected specimen brush or by another sampling method.

APACHE↗

PubMed1997

Upmodulation of multinucleated cell formation in long-term human bone marrow cultures by leukaemia inhibitory factor (LIF).

Inflammatory processes are mediated by many cellular events involving different cell types (leukocytes, monocytes, stromal cells, etc.). Numerous soluble mediators regulate these reactions, including leukaemia inhibitory factor (LIF), a cytokine which may play an important role in inducing acute-phase protein synthesis by hepatocytes during inflammation. This study was designed to determine the effects of LIF on the human monocyte/macrophage lineage and provide a better definition of its behaviour during systemic inflammation. In-vitro exposure of human long-term bone marrow cultures to recombinant human LIF significantly increased (about two-fold) the number of multinucleated cells (MNC) formed after three weeks of culture. These LIF-induced MNC expressed tartrate-resistant acid phosphatase, and LIF increased this intracellular activity by about 50%. MNC displayed phagocytotic activity but were unable to degrade sperm whale dentin or respond to human calcitonin. They did not possess the main characteristics of osteoclasts and were in fact macrophage polykaryons. Our results demonstrate for the first time that LIF can induce macrophage polykaryon formation from human bone marrow culture, suggesting that this factor not only produces leukocytes but also has a direct influence on the monocyte/macrophage lineage.

Acid Phosphatase↗

PubMed1997

[Incidence of myocardial lesions after vascular surgery: diagnosis by troponin Ic].

OBJECTIVE: To compare the incidence of myocardial damages diagnosed following vascular surgery using the cardiac troponin I measurement technique and conventional methods. STUDY DESIGN: Prospective epidemiological study. PATIENTS: Fifty-four patients who underwent surgery for either aneurysmal disease in 28 cases or occlusive aortic disease in 26 cases. METHODS: Plasma concentration of cardiac troponin I (significant at a concentration > 1.5 ng.mL-1) was measured by immunoenzymofluorimetry on the second and fifth postoperative days. Conventional monitoring methods included daily electrocardiogram (ECG), enzymatic assay of total-PCK, and measurement of plasma levels of the MB isoenzyme of phosphokinase creatine (MB-PCK) (significant at > 1 ng.mL-1 and RI > 1.5). RESULTS: The cardiac troponin I measurement technique allowed the diagnosis of minor myocardial damages during the postoperative period in five patients, whereas with the conventional methods (clinical signs. ECG, and MB-PCK) only three myocardial lesions were diagnosed. CONCLUSION: The cardiac troponin I measurement technique allows diagnosis of minor myocardial damages following vascular surgery. Conventional methods underestimate the incidence of these damages.

Aged↗

PubMed1997

Study of some phagocyte membrane receptors in patients receiving intravenous polyvalent immunoglobulins as adjunct treatment for nosocomial pneumonia.

PURPOSE: Phagocytosis is a major mechanism of defense against bacterial infections. The ingestion of bacteria by phagocytes involves a variety of cell membrane recognition structures and, among them, immunoglobulin receptors. The aim of this study was to test the phagocytic activity of granulocytes and monocytes of intensive care unit (ICU) patients, and to evaluate the effects of intravenous polyvalent immunoglobulins (IVIG) used as adjunct treatment of nosocomial pneumonia on some phagocyte membrane receptors of these patients. MATERIALS AND METHODS: The phagocytic activity of granulocytes and monocytes of 41 mechanically ventilated patients with nosocomial bacterial pneumonia was studied during the acute phase of infection. These ICU patients were compared with 21 hospitalized, noninfected volunteer patients hospitalized in a medical ward. Peripheral blood granulocytes and monocytes were studied. Of the 41 ICU patients, after randomization, 21 received IVIG at a dose of 1 g/kg for 3 days. The 41 ICU patients were compared with the 21 non-ICU, noninfected hospitalized controls. The 21 ICU patients who received 3 days of IVIG were also compared with the 20 ICU patients not receiving IVIG. Cells were tested in standard immunoglobulin-free medium (fetal calf serum) and in the presence of patients' serum. Blood granulocytes and monocytes were purified and separately exposed to three types of particles: antibody-coated erythrocytes (to test immunoglobulin receptors), opsonized zymosan (to test C3 receptors), and glutaraldehyde-treated erythrocytes (to test lectinlike or other nonspecific binding sites). Phagocytosis and superoxide anion production (oxidative burst) were measured. RESULTS: Granulocytes of ICU patients compared with those of non-ICU, noninfected patients exhibited a substantial decrease of zymosan ingestion (P < .05), whereas phagocytosis of other particles was normal. Monocytes from the ICU patients, compared with those of the non-ICU, noninfected patients, displayed an unselective overall decrease of phagocytic ability for the three particle types (P < .05). The phagocytosis activity of the three membrane receptor species of blood monocytes and granulocytes of ICU patients was not significantly modified by the IVIG infusion. For both monocytes and granulocytes, no significant improvement was observed in the fraction of cells that ingested at least one foreign particle and the mean number of particles per cell having phagocytized at least one foreign particle. Granulocyte and monocyte functions were also tested by the production of reduced ferricytochrome and no significant improvement in the oxidative burst was observed after infusion of IVIG. CONCLUSION: Infected ICU patients display a deficiency of phagocytosis membrane receptors of blood granulocytes and monocytes. The addition of IVIG to standard therapy does not improve the phagocytic activity of ICU patients with nosocomial pneumonia.

Adult↗

PubMed1997

Early and fatal immune haemolysis after so-called 'minor' ABO-incompatible peripheral blood stem cell allotransplantation.

A 38-year-old man, blood group A+, was allotransplanted for multiple myeloma from his fully matched sister, blood group O+. Anti-A antibodies IgG and IgM titres of the donor were low. Allogeneic peripheral blood stem cells were harvested by leukapheresis after subcutaneous administration of G-CSF. Rapid engraftment occurred since 5.6 x 10(9)/l leukocytes were achieved on day +9 post-transplant. At this time a severe immune haemolytic syndrome occurred and direct antiglobulin test was positive (IgG and C3d). Elution showed an anti-A specificity. Evolution was rapidly unfavourable related to multiorgan failure. The patient died on day +20 post-transplant.

ABO Blood-Group System↗

PubMed1997

Concentrations of prophylactic ceftriaxone in abdominal tissues during pancreatic surgery.

Ceftriaxone concentrations in abdominal tissues were evaluated after administration as antibiotic prophylaxis for pancreatic surgery. Ten patients were given ceftriaxone (1 g i.v.) 30 min before surgery. Ceftriaxone concentrations in fatty tissues ranged from 2.5 to 6.2 microg/g. Ceftriaxone concentrations were 6.0 +/- 8.6 microg/g in pancreatic tissues, 2.1 +/- 2.5 mg/L in pancreatic fluid, 1179 +/- 1271 mg/L in pancreatic bile, and 18 +/- 16 microg/g in the liver. In fatty tissues, 8-10 patients had tissue levels greater than the MIC90 for Staphylococcus aureus and Escherichia coli and the 10 patients had tissue levels greater than the MIC90 for Klebsiella pneumoniae and Proteus mirabilis. In other tissues, penetration was greater than the MIC90 for potential pathogens in 50-100% of the patients.

Abdominal Muscles↗

PubMed1997

A novel supraclavicular approach to brachial plexus block.

We describe a novel supraclavicular approach to the brachial plexus. Designated as the intersternocleidomastoid technique, this new approach was tested in unembalmed cadavers. It was then applied for evaluation to 150 ASA grade I or II patients scheduled for elective surgery or physiotherapy of the upper limb or for treatment of reflex sympathetic dystrophy associated with painful shoulder. The new approach was easy to master because of a very simple surface landmark, i.e., the triangle formed by the sternocleidomastoid heads, which were visible and palpable in most patients studied (90%). The procedure was effective intraoperatively, providing satisfactory anesthesia in 140 patients (93%), partially satisfactory blocks in 6 (4%), and unsatisfactory blocks in only 4 (3%). The catheter entry point is cephalad enough not to obscure the surgical field on the shoulder. Catheter insertion was successful in 63 of 70 patients. Postoperative analgesia was provided for 48 h or more in 45 patients and for 24 h in 18 patients. Only minor complications were observed: asymptomatic phrenic nerve block in 89 patients (60%), transient Horner's syndrome in 15 (10%), transient recurrent laryngeal nerve blockade in 2, and misplacement of the catheter into the subclavian vein in 1 patient. No pneumothorax was observed.

Adult↗

PubMed1997

Diagnosis of ventilator-associated pneumonia: an evaluation of direct examination and presence of intracellular organisms.

BACKGROUND: Ventilator-associated pneumonia (VAP) requires early diagnosis and adequate antibiotic therapy. The aim of this prospective postmortem study was to assess the accuracy of direct examination and quantification of intracellular organisms (ICO) for the diagnosis of VAP. METHODS: Total and differential cell counts were performed on fluids recovered using nonbronchoscopic sampling techniques (blind bronchial sampling [BBS], mini-bronchoalveolar lavage [mini-BAL]) and from bronchoalveolar lavage (BAL) performed during fiberscopy. These 3 sampling techniques were done within 15 min of death without discontinuing mechanical ventilation. Quantification of ICO was performed on each sample recovered from the various sampling procedures. Gram reaction and morphology of bacteria were evaluated on Gram smears. RESULTS: The results of each technique were compared with histology and culture of lung tissue specimens obtained by surgical pneumonectomies in 28 patients who died after at least 72 h of mechanical ventilation. Histology was positive in 13 patients and negative in 15 patients. When only VAP with positive lung culture was considered (histologic signs of bronchopneumonia plus positive lung tissue culture), the sensitivity of Gram staining on BAL, mini-BAL, and BBS was 56%, 44%, and 56%, respectively. If all samples were considered, the sensitivity and the specificity of the determination of the percentage of ICO were low (less than 70%) whatever the sampling technique. CONCLUSIONS: For initial therapeutic guidance, direct examination and presence of ICO do not contribute for establishing the diagnosis of VAP, essentially because of a lack of sensitivity. However, when positive, Gram staining can obviously guide initial antibiotherapy.

Aged↗

PubMed1996

[Transfusion strategy in programmed hemorrhagic orthopedic surgery].

OBJECTIVES: Prospectively assess autologous blood transfusion for programmed orthopedic procedures. METHODS: From January 1 to December 31 1993, 307 patients underwent programmed orthopedic procedures: total hip replacement (n = 191), total knee replacement (n = 83) and osteotomy (n = 33). General (94%) or spinal anesthesia (6%) was used. The anesthesist explained transfusion techniques and patients gave informed consent for inclusion in an autologous transfusion protocol including differed autologous transfusion, intentional normovolemic hemodilution and intraoperative transfusion of shed blood. RESULTS: A total of 269 autologous transfusion were performed among the 307 patients (87.6%). This was sufficient in 242 cases (78.8%) and in 65 (21.2%) homologous transfusion was required. Among the 269 patients given autologous transfusion, differed transfusion was used in 145 (53.9%), intentional normovolemic hemodilution in 124 (46%) and intraoperative transfusion of shed blood in 222 (82.5%). Among the patients given a differed autologous transfusion, 9 (6.2%) required a homologous transfusion and among the 40 patients in which all 3 techniques were used, only 2 (5%) received homologous blood, both due to secondary complications. CONCLUSION: These findings show that when differed autologous transfusion is included in the transfusion strategy, less than 10% of the patients require homologous blood. In addition, when the 3 autologous transfusion techniques are used, the rate of homologous blood transfusion approaches zero.

Adolescent↗

PubMed1996

[Laparoscopic cholecystectomy in a patient with Steinert disease].

Steinert's disease or myotonic myopathy is associated with chronic restrictive respiratory insufficiency. A case of a patient with Steinert's disease undergoing laparoscopic cholecystectomy, with a full recovery within three days is reported. It is concluded that laparoscopic surgery is a possible therapeutic tool in patients suffering from a myopathy.

Adult↗

PubMed1996

[Diagnostic characteristics of acquired pneumonia in patients under mechanical respiration].

Ventilator-associated pneumonias (VAP) are the most frequent nosocomial lung infections. Histological diagnosis is the standard for reference. A diagnosis of VAP can be considered in presence of fever or hypothermia, hyperleucocytosis or leucopenia, worsening of blood gases, and new radiological infiltrate. Their diagnostical value is dependent on the number of included manifestations. A clinical pulmonary infection score (CPIS) has been produced and compared with histological data. Bacteriological data are essential for an adapted antibiotherapy. The blind non-protected specimen brush is inexpensive and reliable at levels of 10(4) and 10(6) CFU.mL-1, the sensitivity and specificity reach 60%. The double-protected catheter is a sensitive and specific test at the level of 10(3) CFU.mL-1. At present its accuracy has only been compared with bronchial brushing. The culture of a 20 mL mini-broncho-alveolar lavage (same material) is specific (50%) but not sensitive enough (< 70%) at the level of 10(3) CFU.mL-1. The culture of the protected telescopic brush is the most expensive test. It does not carry a risk of contamination, but does not detect a significant amount of VAP even at a level below 10(3) CFU.mL-1. Due to its high specificity it is used as the reference test in numerous studies. The endoscopic broncho-alveolar lavage provides a rapid diagnosis. Although not protected, it carries a low risk of false positives. It also allows the diagnosis of non-bacterial or atypical bacterial lung infections. The diagnosis can also be obtained with lung biopsy which however carries a risk in case of mechanical ventilation, whatever the technique. Except for the protected double catheter, a direct examination has been advocated, for the differentiation between infection and colonization and the improvement of the performances of the simple culture of the broncho-alveolar lavage (search for intra-cellular bacteria).

Biopsy↗

PubMed1996

Cytomegalovirus. An unexpected cause of ventilator-associated pneumonia.

BACKGROUND: Cytomegalovirus (CMV) frequently is observed in immunocompromised hosts. The aim of this study was to report cases of ventilator-associated CMV pneumonia diagnosed by pathologic examination in intensive care patients without acquired immunodeficiency syndrome or hematologic malignancy or who were not receiving immunosuppressive agents. METHODS: From June 1, 1989, to May 31, 1994, 2,785 patients were hospitalized. During the study period, 60 autopsies and 26 open-lung biopsies were performed in nonimmunocompromised patients who were seen with acute respiratory failure and/or symptoms suggestive of ventilator-associated pneumonia. Cytomegalovirus pneumonia was diagnosed using pulmonary samples by the identification of large cells with large nuclei containing a basophilic or eosinophilic inclusion surrounded by a light halo. These typical findings always were associated with a diffuse interstitial pneumonitis. RESULTS: Cytomegalovirus pneumonia was diagnosed after histologic examination in 25 patients. The reason for admission to the intensive care unit was major surgery in 13 patients and medical problems in 12 patients. Ventilator-associated CMV pneumonia was diagnosed by histologic examination 22.4 +/- 8.8 days after admission to the intensive care unit (median 18 days; range 10-40 days). The clinical description was similar with the 25 patients who were seen with ventilator associated CMV pneumonia and the 61 patients without ventilator-associated CMV pneumonia. However, there was a more severe hypoxemia 72 +/- 16 vs. 95 +/- 41 mmHg, P < 0.05) and a higher Weinberg's radiologic score (9.2 +/- 1.9 vs. 7.4. +/- 2.7, P < 0.05) in the ventilator-associated CMV pneumonia group. Diagnosis of ventilator-associated CMV pneumonia was made for 9 of 17 patients when shell-vial culture technique using fluorescein-labelled antibody E 13 was performed on bronchoalveolar lavage products. Four of the eight patients treated by ganciclovir therapy died of multiple organ dysfunction syndrome. CONCLUSIONS: The diagnosis of ventilator-associated CMV pneumonia should not be excluded in intensive care patients, even those without acquired immunodeficiency syndrome, hematologic malignancy, or immunosuppressive agents on admission.

Aged↗

PubMed1996

Investigation of outbreaks of Enterobacter aerogenes colonisation and infection in intensive care units by random amplification of polymorphic DNA.

During a 4-month period, 41 isolates of Enterobactor aerogenes were cultured from different specimens from a 14-bed intensive care unit (ICU1). These were obtained from 12 patients out of a total of 187 patients admitted to the ICU. Sixteen E. aerogenes isolates were cultured from another ICU (ICU2) 6 months later. Six non-outbreaks associated strains were included as controls and all the isolates were compared by random amplification of polymorphic DNA (RAPD), with three different 10-mer oligonucleotide primers. RAPD fingerprinting with primer AP12h was as discriminatory as the combined results from all three primers and defined 22 different patterns for the 41 isolates from the ICU1. In nine instances, isolates with indistinguishable RAPD patterns were detected in two-to-five patients over a 3-15-day period, suggesting patient-to-patient transmission. During their stay in ICU1, patients harboured one-to-12 distinguishable isolates. Isolates from ICU2 were indistinguishable by RAPD analysis with the three different primers. These findings suggest that the cluster of colonisations and infections in ICU1 was a 'false outbreak', consisting of successive patient-to-patient transmission of different E. aerogenes strains. In contrast, the outbreak on ICU2 probably involved the extensive spread of a single strain.

Adult↗

PubMed1996

Effect of ventilator-associated pneumonia on mortality and morbidity.

The aim of this study was to evaluate the attributable mortality and excess intensive care unit (ICU) stay as linked to ventilator-associated pneumonia (VAP) in a medical-surgical ICU. We performed a matched cohort study. The diagnosis of VAP was established when clinical, biologic, and radiologic signs of VAP were associated with the presence of at least one microorganism at a concentration > or = 10(3) CFU/ml on the protected specimen brush sample. Each case patient with VAP was matched to one control patient on the basis of the following potential confounding factors: same diagnosis and same indication for mechanical ventilation, same age +/-5 yr, same sex, same APACHE II score +/-5 on admission. In addition, control patients had to be ventilated for at least as long as the case patient prior to the onset of VAP, and date of admission of the case and control patients had to be matched within 1 yr. In 85 of the 97 patients with VAP, we were able to match one case patient with one control patient. Mortality was similar in both case (40%) and control (38.8%) patients. The duration of mechanical ventilation was increased in survivor case patients (27.2 +/- 24.7 d) compared with survivor control patients (18.5 +/- 15.7 d) (p < 0.01). The duration of hospitalization in ICU was increased in survivor case patients (34.9 +/- 23.6 d) compared with survivor control patients (26.1 +/- 18.6 d) (p < 0.02). When confounding factors were controlled, VAP did not appear to increase mortality.

APACHE↗

PubMed1996

[Amphotericin B into parenteral lipid emulsions. Galenic stability of mixtures. Preliminary results].

The amphotericin B in glucose solution is the reference's treatment of the major systemic mycoses. Because of its bad tolerance, certain authors put forward others vehicules such as fat emulsions. The aim of our work has been to study the physico-chemical stability of two regeneration's methods; P1: direct regeneration. P2: regeneration of 50mg of Fungizone in 5 ml of glucose serum and laced with 45 ml of Ivelip 20% versus PR: 50 mg of Fungizone in 50 ml of glucose serum. Our results seem to show that the P1 is totally incompatible with a parenteral administration, because 23% of the granulometric population has a diameter superior to 5 microns. The solution P2 seems better even if the pH is different from PR and a light depot comes after reconstitution.

Amphotericin B↗

PubMed1996

[Mycological monitoring of Candida albicans infections in various hospital care units. Molecular typing of isolated strains and epidemiological survey].

To evaluate risk factors associated with the nosocomial infection of Candida albicans, a prospective study is conducted twice for three months in three intensive care units. Samples from patients HIV negatives, non neutropenic and non immunodepressive are collected as they came in the unit, on several anatomic sites. Every C. albicans carriers are included in a mycological monitoring. Samples from environmental surfaces, hands and deep pharynx from hospital personnel were also cultured. Strains genetic profile are defined by isoenzyme electrophoresis technique. Thirteen polymorphic loci allowed samples classement into 52 electrophoretic types (ET). If only one crossed contamination is described, strains regroupment into some ET incites us to extend this study. C. albicans strains from patients closed environment have never been isolated.

Adolescent↗

PubMed1996

Histological features of large bone allografts.

We performed biopsies during reoperation for minor complications in two active young patients 9 and 19 months after massive bone allograft implantation for bone tumour. The grafts were dead and resorption-apposition activity, when present, was predominantly in subperiosteal areas. Inflammatory infiltration was very seldom found. Features considered as 'microfractures' or 'microcracks' were noted in the cortical ring together with the formation of woven bone, in areas with remodelling. Such cracks are likely to be of mechanical origin and do not inevitably lead to complications.

Adult↗