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F Lebargy

Publications and source records attributed to F Lebargy.

At least 37 records · Page 2Linked to original sources
PubMed1994

Prospective study of pulmonary function for cyclomegalovirus infection after renal transplantation.

Pulmonary involvement remains the main complication of cytomegalovirus (CMV) infection in renal transplantation (RT). Early diagnosis is required for the best management of patients, and preemptive therapy could be a successful approach. In order to define the predictive value of lung alveolocapillary abnormalities. We prospectively studied 26 renal transplant recipients for their diffusing capacity of carbon monoxide (DLCO) and their pulmonary clearance of a 99mTc-DTPA aerosol. Patients were studied before transplantation and then every 2 weeks up to the end of the 3rd month following RT. Viral blood cultures and serological determinations were performed every week during these first 3 months. Bronchoalveolar lavage (BAL) was done in case of CMV disease. Statistic analysis was done using Student's t-test and Pearson's chi-square test. During the 3-month follow-up, 13 patients remained free of CMV infection. Three non-infected and 8 infected patients showed DTPA clearance abnormalities (P < 0.05). Six non-infected and 7 infected patients showed DLCO disturbance (P > 0.50). DTPA clearance were significantly modified on days 45 and 60 in the infected group. Serial DTPA scanning, in association with viral blood cultures, could be a useful test to avoid unnecessary BAL in a preemptive therapy strategy.

Bronchoalveolar Lavage↗
PubMed1994

Evaluation of human cytomegalovirus latency in alveolar macrophages.

Cytomegalovirus (CMV) pneumonia is a major cause of illness in immunocompromised patients. The sites of human CMV (HCMV) latency are still not clearly defined. The present study was therefore designed to investigate the hypothesis that alveolar macrophages could constitute such a site. DNA extracted from alveolar cells collected by bronchoalveolar lavage and blood mononuclear cells (BMC) from asymptomatic nonimmunocompromised CMV-seropositive and CMV-seronegative patients were investigated. Controls consisted of DNA from a CMV-infected MRC5 cell line, BMC and alveolar macrophages from patients with acute CMV infection. Polymerase chain reaction (PCR) was designed for detection of a 290-bp fragment of the promoter region of the major immediate early gene of HCMV conserved within the various HCMV strains and without homology with the human genome. The limit of detection of the method was evaluated to be one HCMV viral copy per 10(4) cells. HCMV DNA was detected in BMC or alveolar cells of all patients with acute CMV infection. In contrast, no HCMV DNA was detected in alveolar cells and BMC from nonimmunocompromised asymptomatic HCMV-seropositive patients. In conclusion, in the present experiment, no latent HCMV could be detected in alveolar cells collected in nonimmunocompromised asymptomatic CMV-seropositive patients.

Adult↗
PubMed1994

HIV-1 in human alveolar macrophages from infected patients is latent in vivo but replicates after in vitro stimulation.

It has been demonstrated that alveolar macrophages (AM) are permissive for human immunodeficiency virus (HIV-1) after in vitro infection. However, data concerning in vivo infection of AM by HIV-1 still conflict. Therefore, we investigated AM collected by bronchoalveolar lavage from 15 HIV-1-infected patients. HIV-1 p24 and Gp120 antigens and viral RNA were not detected by immunocytochemistry and in situ hybridization, respectively, using 35S-labeled 3 kb Pol-Env, 0.350 kb Gag, and 0.150 kb U5 LTR cRNA probes. In contrast, when using polymerase chain reaction on DNA extracted from purified AM, HIV-1 DNA was detected in the seven patients tested. After short-term culture of alveolar cells from three HIV-1-infected patients and in vitro stimulation with granulocyte/macrophage colony-stimulating factor (GM-CSF) and tumor necrosis factor-alpha (TNF-alpha), HIV-1 replication was observed in most of the AM. These results demonstrate that AM are latently infected by HIV-1 in vivo but are not a site for viral replication. In contrast, HIV-1 replication occurs when AM are withdrawn from their local environment, enhanced by GM-CSF and TNF-alpha stimulation. This suggests either a negative control or an inadequate stimulation of HIV-1 replication in the alveolar environment.

Cell Line↗
PubMed1993

[Toxicology of tobacco].

Tobacco is one of the major toxic agents in our civilization. The extent and severity of the current smoking epidemics are due to the use of industrial cigarettes: their smoke, less irritant than that of cigars and pipe, can be inhaled intensively with rapid absorption of all toxic compounds. Tobacco smoke is composed of a gas phase (CO2, CO, CNH, etc.) and a particle phase (a very fine aerosol) in which more than 4000 substances have been identified. The main toxic compounds in tobacco are Co, nicotine and tars. CO binds to haemoglobin to form COHb, a major factor of hypoxia and vascular accidents. Within a few seconds, nicotine reaches the brain where it binds to specific receptors, which explains its psycho-active effects (psychological dependence) and the induction of physical dependence. This dual dependence is responsible for the failures and relapses observed in attempted withdrawals. Furthermore, nicotine stimulates the sympathetic system with hypersecretion of catecholamines resulting in vascular complications. Tars contain carcinogenic substances, such as aromatic hydrocarbons, which exert local effects on the respiratory tract and systemic effects since they are absorbed by the lungs; this explains the remote neoplasias such as cancer of the bladder. Tars also contain irritant agents (acrolein, formaldehyde, etc.) and oxidative substances responsible for chronic bronchitis and emphysema. Thus, all organs and tissues can be damaged by the toxic compounds that are present in tobacco and, in particular, in tobacco smoke.

Humans↗
PubMed1993

Expression of tumor necrosis factor-alpha gene in alveolar macrophages from patients with the adult respiratory distress syndrome.

The adult respiratory distress syndrome (ARDS) is a complex syndrome in which pathogenesis is multifactorial. TNF-alpha, known to be pivotal in tissue damage, has been shown to have high levels in blood and alveolar fluid in ARDS. The identification of the cells responsible for this production in the alveolar milieu has not yet been reported. In order to evaluate the TNF-alpha gene expression in ARDS we have analyzed by in situ hybridization, using RNA probes, alveolar macrophages (AM) obtained by BAL from seven patients with ARDS, eight patients with miscellaneous respiratory diseases, and three control patients. In freshly collected AM from patients with ARDS, 66 +/- 14.5% cells expressed the TNF-alpha gene without in vitro stimulation. This TNF-alpha expression does not result from the BAL procedure itself since only a few unstimulated control AM contained TNF-alpha mRNA transcripts. TNF-alpha expression in AM is not restricted to patients with ARDS since it has also been observed in miscellaneous respiratory diseases; however, this expression is a constant feature in ARDS. These results demonstrated the major role of AM in the intra-alveolar production of TNF-alpha, and they point out the necessity in ARDS for a specific intra-alveolar therapy.

Adult↗
PubMed1992

Bronchoalveolar lavage in immunocompromised patients. Clinical and functional consequences.

Fiberoptic bronchoscopy and bronchoalveolar lavage are major tools in the diagnosis of acute pneumonia in immunocompromised patients. We conducted a prospective study to assess the morbidity associated with this procedure in 14 patients with AIDS and 16 patients with drug-induced immunosuppression. No patient had a PaO2 lower than 70 mm Hg with additional oxygen. Clinical data, chest roentgenogram, pulmonary function test, forced vital capacity, forced expiratory volume in one second, and arterial blood gases were recorded before and after bronchoscopy. Arterial oxygen saturation was monitored during the procedure, and initial, lowest, and final saturation values were noted. The patients were separated into three groups on the basis of chest roentgenographic findings. No procedure-induced pneumonia or need for tracheal intubation occurred. Minor clinical symptoms induced by the lavage in seven patients resolved spontaneously. By contrast, mean SaO2 decreased markedly during the procedure from 94 +/- 3 to 87 +/- 5 percent (p less than 0.0001) and returned to only 89 +/- 5 percent at the end of the procedure. Lowest SaO2 during the procedure and final SaO2 correlated poorly with initial SaO2 but correlated well with initial FVC and FEV1 (p less than 0.01). The PFT values were lower following bronchoscopy. O2 desaturation was more pronounced in patients with severe roentgenographic abnormalities. No significant differences were found between the three groups of patients, or between the AIDS and DII patients in terms of changes in PFT values. We conclude that in immunocompromised patients, bronchoscopy with BAL induces severe arterial oxygen desaturation which is correlated with initial PFT and chest roentgenographic findings, and most of these abnormalities are transient and do not lead to major complications.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Constitutive IL-2 expression in HTLV-I-infected leukaemic T cell lines.

An IL-2 autocrine growth circuit has been proposed as a major mechanism in HTLV-I-related leukaemogenesis. We have developed a polymerase chain reaction combined with reverse transcription RT-PCR to detect IL-2 transcripts and a sensitive immunostaining method for IL-2 protein. Combination of these two methods with in situ hybridization demonstrated that most cells of the T cell line IARC 301.5, whose proliferation is stimulated by autocrine IL-2, constitutively synthesize IL-2. This pattern was also found in the HTLV-I T cell lines HUT, MT2 and C 8166/45, and in the HTLV-I-negative T cell lines Jurkat and HSB2 but not MOLT4. Four non-lymphoid cell lines and cultured fibroblasts were negative, in agreement with the T cell specificity of IL-2 synthesis. Hence, most T cell lines tested, whether HTLV-I-infected or not, constitutively synthesize IL-2, suggesting a possible common feature of leukaemic T cell lines. The presence of IL-2 transcript and protein in most cells of the reacting cell lines is consistent with an autocrine process possibly involved at some stage in acquiring growth autonomy.

Antibodies, Monoclonal↗
PubMed1990

Tissue-specific expression of two gamma-glutamyl transpeptidase mRNAs with alternative 5' ends encoded by a single copy gene in the rat.

Two different cDNAs have been isolated and characterized from a rat kidney cDNA library. The two cDNA sequences are identical in the coding region and in the 144 bases upstream from the initiation codon but have alternate sequences (154 and 138 bases) at their 5' ends. Primer extension analysis on kidney mRNA reveals that both cDNAs are full-length and correspond to two mRNAs of nearly the same size (2142 and 2127 bases). Synthesis of two mRNAs with alternative 5' ends can be explained only by initiation at two separate promoters on the single rat gamma-glutamyl transpeptidase (GGT) gene. The alternate 5' end nucleotide sequences were used as probes to detect the corresponding mRNAs in several rat tissues. In the kidney, the expression of both RNAs was detected by in situ hybridization in the distal part of the proximal convolutions of the renal tubule. Northern blot analysis of kidney mRNAs reveals that the expression of both mRNAs increases from birth to the adult stage. Neither of these two transcripts is expressed in the liver or in seminal vesicles in which a larger mRNA (2.4 kilobase pairs) is transcribed from the same gene. Thus, two GGT mRNAs, initiated on two separate promoters on the single GGT gene, are expressed in the rat in a tissue-specific manner and coordinately regulated.

Animals↗
PubMed1990

Expression of Tau protein and Tau mRNA in the cerebellum during axonal outgrowth.

UNLABELLED: "In situ" hybridization and immunohistochemical analysis of the expression of Tau mRNAs and Tau proteins in the developing cerebellum showed that: 1. At early postnatal stages Tau mRNAs are expressed in the deeper region of the external granular layer (EGL II) i.e. in the cells that begin to migrate from the proliferative zone. Little labeling was seen in the upper layer (EGL I) where the cerebellar interneurons actively proliferate during the first two postnatal weeks. Anti-Tau antibodies failed to detect Tau proteins both in EGL I and II. 2. Tau transcripts were also clearly detected in the migrating cells present in the molecular layer; no Tau immunoreactivity was seen in this layer. This suggests that Tau mRNAs remain very poorly translated in the migrating granule cells and in the other interneurons. 3. Tau proteins begin to be detected at postnatal day 8 in the molecular layer but only at the level of the parallel fibers that are present in the Purkinje cell dendritic field. This suggests that the Tau mRNAs transcribed in the migrating cells are not actively translated for several days and that Tau proteins accumulate only in the more mature sections of their axons, the parallel fibers. IN CONCLUSION: Tau mRNAs are transcribed in the migrating cells several days before Tau proteins are actively translated and transported to their axons. Tau proteins accumulation occurs only at the end of granule cell migration i.e. when the parallel fibers interact with their post-synaptic counterparts, the dendrites of the Purkinje cells. Thus, axonal outgrowth and differentiation seem to be a multistep process.

Aging↗
PubMed1990

HIV-1 infection of lung alveolar fibroblasts and macrophages in humans.

We have studied the infected cell populations in the lungs of four human immunodeficiency virus type 1 (HIV-1) seropositive patients suffering from lymphocytic alveolitis or lymphocytic interstitial pneumonitis. Adherent cells were obtained by bronchoalveolar lavage (BAL) and were analyzed by various technical approaches. The cells considered here were alveolar macrophages and fibroblasts, and could be clearly identified morphologically and by the expression of specific cell-surface markers using monoclonal antibodies. The presence of HIV-1 in both of these cell types was established by serological, virological, and molecular procedures. Our results show that alveolar macrophages and fibroblasts are naturally infected in the lungs of HIV+ patients. Both cell types express the CD4 receptor molecule, in contrast to skin fibroblasts which are negative. Alveolar macrophages and fibroblasts thus may act as eventual HIV-1 reservoirs in vivo, and are probably involved in the induction of inflammatory reactions because they are targets for CD8 cytotoxic T lymphocytes (CTL).

AIDS-Related Complex↗
PubMed1990

Localization by in situ hybridization of gamma-glutamyl transpeptidase mRNA in the rat kidney using 35S-labeled RNA probes.

gamma-Glutamyl transpeptidase (GGT) is involved in the extraction of plasma glutathione in the postglomerular compartment of the kidney. The enzyme is distributed in the proximal tubule associated with the apical brush border. Using in situ hybridization with 35S-labeled anti-sense and sense RNA GGT probes on rat kidney cryostat sections, the present study demonstrates that GGT mRNA transcripts are detected in proximal tubules localized in the inner cortex, outer medulla, and medullary rays of the cortex. Such a distribution suggests that the GGT gene is mainly expressed in the more distal part of the proximal tubule, i.e., the pars recta. As a control, in situ hybridization has also been performed using a 35S-labeled beta-actin anti-sense RNA probe showing a diffuse pattern of distribution of beta-actin RNA transcripts particularly in the outer cortex. This highly sensitive method using single strand asymetric RNA probes, with a markedly reduced nonspecific binding is promising for the study of gene expression patterns in the kidney in order to clarify their heterogeneity in the various segments of the nephron.

Animals↗
PubMed1989

Intraepithelial T-lymphocyte subsets in the airways of normal subjects and of patients with chronic bronchitis.

Lymphocyte infiltration of central airway epithelium was evaluated in 13 normal nonsmoking subjects (Group 1), in 11 smokers without clinical signs of chronic bronchitis (Group 2), and in 34 patients who were smokers with chronic bronchitis and mild airflow limitation (Group 3). Bronchial samples were obtained through fiberoptic bronchoscopy. Murine monoclonal antibodies directed against cell-surface antigens and an immunoperoxidase technique were used on cryostat sections to label in situ the following lymphocyte populations: T-lymphocytes (CD3+), helper/inducer T-cells (CD4+), suppressor/cytotoxic T-cells (CD8+) and B-lymphocytes (leu 12+). Virtually no B-cells were found in central airway epithelium from subjects of any group. Conversely, consistent infiltration of epithelial layers with T-lymphocytes of both subsets was observed in all subjects, with a constant predominance of CD8+ over CD4+ cells. For any T-cell marker, differences between mean scores from Group 1 and Group 2 subjects were not statistically significant. On the other hand, mean lymphocyte numbers of both subsets were found increased in patients from Group 3 compared with subjects from the two other groups: statistically significant differences were observed for CD3+, CD4+, and CD8+ cells (p less than 0.001). Furthermore, lymphocyte scores at two different airway generation were compared in some patients from Groups 2 and 3, and a significant positive correlation was observed. These results suggest that T-lymphocyte infiltration of central airway epithelium (1) may be a naturally occurring phenomenon that is amplified in the airways of smokers with chronic bronchitis, and (2) may represent the counterpart to the intraepithelial population of the intestine.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Effects of digoxin on diaphragmatic strength generation in patients with chronic obstructive pulmonary disease during acute respiratory failure.

We studied the effects of digoxin, a compound that has an inotropic effect on the myocardium, on diaphragmatic function in 8 patients with chronic obstructive pulmonary disease. All the patients were in acute respiratory failure and were artificially ventilated. Diaphragmatic strength was assessed by measuring the transdiaphragmatic pressure generated at functional residual capacity during bilateral supramaximal electrical stimulation of the phrenic nerves. The latter were stimulated before and at 45 and 90 min after administration of digoxin (0.02 mg/kg infused for 10 min). In all the patients, cardiac output was measured by the thermodilution technique using a Swan-Ganz catheter placed in the pulmonary artery. Arterial blood gases and pH were maintained within normal range by mechanical ventilation. In all the patients, digoxin plasma levels reached the therapeutic range (mean values, 2.82 +/- 0.17 and 2.90 +/- 0.20 nmol/L at 45 and 90 min, respectively) after digoxin administration. Diaphragmatic strength improves significantly after digoxin administration, the transdiaphragmatic pressure for an identical phrenic stimulation increasing by 19.5% (p less than 0.001) on the average. This increase was noted 45 and 90 min after digoxin administration. We conclude that digoxin has a potent effect on diaphragmatic strength generation that may be beneficial in patients with chronic obstructive pulmonary disease during acute respiratory failure. Furthermore, this inotropic positive effect of digoxin on the diaphragm, as previously observed for the myocardium, emphasizes the similarities between these 2 contractile tissues.

Action Potentials↗
PubMed1985

[Is bronchial fiberscopy always indicated in hemoptysis? Apropos of 427 tests].

The authors report the results of a retrospective study of 427 fiberoptic bronchoscopies in patients with haemoptysis. The patients were classified into 4 groups according to the results: Group I: a specific diagnosis was made (cancer, tuberculosis, infection); 151 cases (35 p. 100); Group II: inflammatory mucosa, 172 cases (40 p. 100); Group III: normal bronchoscopy, 84 cases (20 p. 100); Group IV, only blood, 20 cases (5 p. 100). Of the 151 patients in Group I, 12 had a normal chest X-ray (8 p. 100); seven of them had bronchopulmonary carcinoma (7 out of 65 cases of cancer: 10.7 p. 100). These results show that bronchoscopy is essential in cases of haemoptysis even when the chest X-ray is normal.

Bronchial Neoplasms↗