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B Crestani

Publications and source records attributed to B Crestani.

At least 37 records · Page 2Linked to original sources
PubMed2000

Differential effects of halothane and thiopental on surfactant protein C messenger RNA in vivo and in vitro in rats.

BACKGROUND: Pulmonary surfactant is a complex mixture of proteins and phospholipids synthetized by alveolar type II cells. Volatile anesthetics have been shown to reduce surfactant phospholipid biosynthesis by rat alveolar type II cells. Surfactant-associated protein C (SP-C) is critical for the alveolar surfactant functions. Our goal was to evaluate the effects of halothane and thiopental on SP-C messenger RNA (mRNA) expression in vitro in rat alveolar type II cells and in vivo in mechanically ventilated rats. METHODS: In vitro, freshly isolated alveolar type II cells were exposed to halothane during 4 h (1, 2, 4%) and 8 h (1%), and to thiopental during 4 h (10, 100 micrometer) and 8 h (100 micrometer). In vivo, rats were anesthetized with intraperitoneal thiopental or inhaled 1% halothane and mechanically ventilated for 4 or 8 h. SP-C mRNA expression was evaluated by ribonuclease protection assay. RESULTS: In vitro, 4-h exposure of alveolar type II cells to thiopental 10 and 100 micrometer increased their SP-C mRNA content to 145 and 197%, respectively, of the control values. In alveolar type II cells exposed for 4 h to halothane 1, 2, and 4%, the SP-C mRNA content increased dose-dependently to 160, 235, and 275%, respectively, of the control values. In vivo, in mechanically ventilated rats, 4 h of halothane anesthesia decreased the lung SP-C mRNA content to 53% of the value obtained in control (nonanesthetized, nonventilated) animals; thiopental anesthesia increased to 150% the lung SP-C mRNA content. CONCLUSIONS: These findings indicate that halothane and thiopental used at clinically relevant concentrations modulate the pulmonary SP-C mRNA content in rats. In vivo, the additive role of mechanical ventilation is suggested.

Actins↗
PubMed2000

Keratinocyte growth factor and hepatocyte growth factor in bronchoalveolar lavage fluid in acute respiratory distress syndrome patients.

OBJECTIVES: To determine bronchoalveolar lavage (BAL) fluid concentrations of keratinocyte growth factor (KGF) and hepatocyte growth factor (HGF), two potent growth factors for alveolar type II epithelial cells, in patients with acute respiratory distress syndrome (ARDS). DESIGN: Prospective study. SETTING: An adult trauma/surgical intensive care unit in an urban teaching hospital. PATIENTS: A total of 32 ventilated patients with pulmonary infiltrates prospectively identified with ARDS (n = 17) or without ARDS (n = 15), including eight patients with hydrostatic edema (HE), and ten nonventilated patients serving as controls. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: BAL was performed 2.88 days +/- 2.4, 3.5 days +/- 2.4, and 2.3 days +/- 2.2 after the lung insult in ARDS, HE, and other non-ARDS patients respectively (p = .32). KGF was detected in BAL fluid in 13 of the 17 ARDS patients (median, 31.6 pg/mL), in one patient with HE, and in none of other non-ARDS patients. In ARDS patients, detection of KGF in BAL was associated in BAL fluid with the detection of type III procollagen peptide (PIIIP), a biological marker of fibroproliferation. In ARDS patients, detection of KGF in BAL was associated with death (p = .02). HGF was detected in 15 ARDS patients (median, 855 pg/mL), in seven patients with HE (median, 294 pg/mL; p = .05 for the comparison with ARDS group), in six of other non-ARDS patients (median, 849 pg/mL; p = .32 with ARDS group). HGF concentrations were higher in nonsurvivors than in survivors (p = .01). None of the ten BAL of controls contained either KGF or HGF. CONCLUSION: KGF was detected almost exclusively in BAL fluid from ARDS patients and correlated with a poor prognosis in this group. In contrast, HGF was detected in the BAL fluid from a majority of patients with or without ARDS. Elevated HGF concentrations were associated with a poor prognosis in the overall group.

Adult↗
PubMed2000

Is high-resolution computed tomography a reliable tool to predict the histopathological activity of pulmonary Langerhans cell histiocytosis?

High-resolution computed tomography (HRCT) has proved to be very useful in the diagnosis and follow-up of pulmonary Langerhans cell histiocytosis (PLCH), but the precise relationships between nodules and thin-wall cysts observed by HRCT, and granulomatous or cystic lesions present in lung tissue, remain to be established. The aim of this study was to compare quantitative data obtained by HRCT and those obtained by histopathological examination of corresponding lung tissue specimens in patients with biopsy-proven PLCH. The results demonstrated that the extent of nodular abnormalities was strongly correlated with the density of florid granulomatous lesions in lung tissue. A strong correlation was also found between the extent of cystic abnormalities and the density of cavitary lesions, but the latter included both still inflammatory cavitary granulomas and cicatricial fibrous cysts. Interestingly, small isolated florid granulomas were found in lung tissue from most patients with a predominant cystic CT scan pattern. Taken together, these results demonstrate that HRCT has to be considered with caution to evaluate the histopathological activity of PLCH. Patients presenting with predominant HRCT cystic abnormalities should benefit from a long-term follow-up. Because these patients are susceptible to developing severe respiratory insufficiency, they should also be considered for treatment as soon as an effective therapy for LCH is available.

Adult↗
PubMed2000

[Diesel particles and allergy: cellular mechanisms].

Urbain air pollutants, particularly diesel exhaust particles are now known to contribute to the increased prevalence of asthma and allergic rhinitis. Diesel exhaust particles act as adjuvants in the immune response and may lead to the enhancement of allergic inflammation. This was first suggested by epidemiological studies and now largely confirmed by numerous experimental studies in animals and humans. We review the different mechanisms involved, including effects on cytokine and chemokine production, as well as activation of different immune cells. We also discuss the metabolic and cellular activation pathways used by polycyclic aromatic hydrocarbons, allergens and their interaction with diesel particles which act in synergy in this immune response toward IgE production and induction of allergic inflammation.

Allergens↗
PubMed2000

111In-pentetreotide scintigraphy in patients with Langerhans' cell histiocytosis.

UNLABELLED: Langerhans' cell histiocytosis is a granulomatous disease that may involve multiple organs and the prognosis of which is highly variable. Because the prognosis depends particularly on the number of tissues involved, the accurate identification of the organs involved by granulomatous lesions is of critical importance. We hypothesized that 111In-pentetreotide scintigraphy would be useful for evaluation of patients with Langerhans' cells histiocytosis. METHODS: Thirteen patients (38.3+/-10.4 y) with Langerhans' cell histiocytosis (8 patients with unifocal lung disease, 5 with multifocal disease) received intravenous 111In-pentetreotide (111-222 MBq), and planar images were obtained at 24 h after injection. Pulmonary uptake was quantified using a lung-to-background ratio (L/B) and compared with a population of 10 normal scintigrams. For the other sites, uptake of radioactivity in disease-related areas was visually assessed. RESULTS: Ten of 12 patients with lung involvement had increased lung uptake (UB, 2.23+/-0.49 versus 1.34+/-0.07; P < 0.001). In the patients with multifocal disease, increased 111In-pentetreotide uptake was found in disease-related areas such as the salivary glands, the skin, the soft tissues, and the bones. However, somatostatin receptor imaging was insensitive for detecting central nervous system and liver involvement and most skin lesions. CONCLUSION: 111In-pentetreotide imaging may be useful in Langerhans' cell histiocytosis. Further study will indicate whether 111In-pentetreotide is a relevant tracer in the management of histiocytosis.

Adult↗
PubMed1999

Inducible expression and regulation of the alpha 1-acid glycoprotein gene by alveolar macrophages: prostaglandin E2 and cyclic AMP act as new positive stimuli.

We have reported that alpha 1-acid glycoprotein (AGP) gene expression was induced in lung tissue and in alveolar type II cells during pulmonary inflammatory processes, suggesting that local production of this immunomodulatory protein might contribute to the modulation of inflammation within the alveolar space. Because AGP may also be secreted by other cell types in the alveolus, we have investigated the expression and the regulation of the AGP gene in human and rat alveolar macrophages. Spontaneous AGP secretion by alveolar macrophages was increased 4-fold in patients with interstitial lung involvement compared with that in controls. In the rat, immunoprecipitation of [35S]methionine-labeled cell lysates showed that alveolar macrophages synthesize and secrete AGP. IL-1 beta had no effect by itself, but potentiated the dexamethasone-induced increase in AGP production. RNase protection assay demonstrated that AGP mRNA, undetectable in unstimulated cells, was induced by dexamethasone. Conditioned medium from LPS-stimulated macrophages as well as IL-1 beta had no effect by themselves, but potentiated the dexamethasone-induced increase in AGP mRNA levels. In addition to cytokines, PGE2 as well as dibutyryl cAMP increased AGP mRNA levels in the presence of dexamethasone. When AGP expression in other cells of the monocyte/macrophage lineage was examined, weak and no AGP production by human blood monocytes and by rat peritoneal macrophages, respectively, were observed. Our data showed that 1) AGP expression is inducible specifically in alveolar macrophages in vivo and in vitro; and 2) PGE2 and cAMP act as new positive stimuli for AGP gene expression.

Adult↗
PubMed1999

Presence of circulating abnormal CD34+ progenitors in adult Langerhans cell histiocytosis.

Langerhans cell histiocytosis (LCH) is related to the proliferation of cells, which are similar to Langerhans cells (LC) but possess many abnormal characteristics. Lesions are widespread and this fact suggests that LCH cells or their precursors are present in the blood of patients. In five adult patients, we have isolated and cultured CD34+ blood progenitors of dendritic cells. We studied their phenotype by flow cytometry and their functional properties in mixed culture with heterologous lymphocytes and with autologous lymphocytes in the presence of tri-nitro-phenyl antigen (TNP). The amount of CD34+ precursors was dramatically higher than controls but a high mortality occurred during the in vitro differentiation. The phenotype of surviving cells was similar to LC phenotype (CD1a+, CD83+, Lag+) but some of them expressed CD2. These cells were able to induce T cell proliferation in mixed culture. They could not initiate primary response to TNP, except in a patient treated with thalidomide. In our hands, these CD34+ cells may be precursors of LCH cells.

Adult↗
PubMed1999

Differential effects of isoflurane and i.v. anaesthetic agents on metabolism of alveolar type II cells.

Alveolar type II (ATII) cells perform many important functions within the lung, including surfactant metabolism. We have investigated the effects of isoflurane and different i.v. anaesthetics on cell metabolism in primary cultures of rat ATII cells. Biosynthesis of phosphatidylcholine, the main phospholipid component of surfactant, was decreased in cells exposed to isoflurane in a dose- and time-related manner. This effect was fully reversible within 2 h after isoflurane removal. Lactate dehydrogenase (LDH) release, an index of cell damage, was increased with isoflurane exposure (1%) over a long incubation period (8-12 h). Enhanced lactate production, reflecting an increase in glycolytic metabolism, was also observed in isoflurane exposed cells. In contrast, metabolism of ATII cells was moderately affected by i.v. anaesthetics. Our data suggest differential metabolism of alveolar homeostasis depending on the anaesthetic agent used.

Anesthetics, Inhalation↗
PubMed1998

Inducible expression of the alpha1-acid glycoprotein by rat and human type II alveolar epithelial cells.

Alpha1-acid glycoprotein (AGP) is a major acute phase protein in rat and human. AGP has important immunomodulatory functions that are potentially important for pulmonary inflammatory response. The liver is the main tissue for AGP synthesis in the organism, but the expression of AGP in the rat lung has not been investigated. We show that AGP mRNA was induced in the lung of dexamethasone-, turpentine-, or LPS-treated rats, whereas AGP mRNA was not detected in the lung of control rats. In the lung of animals treated intratracheally with LPS, in situ hybridization showed that AGP gene expression was restricted to cells located in the corners of the alveolus, consistent with an alveolar type II (ATII) cell localization. The inducible expression of the AGP gene was confirmed in vitro with SV40 T2 cells and rat ATII cells in primary culture: maximal expression required the presence of dexamethasone. IL-1 and the conditioned medium of alveolar macrophages acted synergistically with dexamethasone. Rat ATII cells secreted immunoreactive AGP in vitro when stimulated with dexamethasone or with a combination of dexamethasone and the conditioned medium of alveolar macrophages. In vivo, in the human lung, we detected immunoreactive AGP in hyperplastic ATII cells, whereas we did not detect AGP in the normal lung. We conclude that AGP is expressed in the lung in cases of inflammation and that ATII cells are the main source of AGP in the lung.

Acute-Phase Proteins↗
PubMed1998

Bronchiolitis obliterans organizing pneumonia syndrome primed by radiation therapy to the breast. The Groupe d'Etudes et de Recherche sur les Maladies Orphelines Pulmonaires (GERM"O"P)

Reports of bronchiolitis obliterans organizing pneumonia (BOOP) occurring in women after radiation therapy for breast cancer have suggested that radiation to the lung could participate in the development of BOOP. We now describe the clinical, radiographic, functional, and bronchoalveolar lavage characteristics of this syndrome in a series of 15 patients reported to the Groupe d'Etudes et de Recherche sur les Maladies "Orphelines" Pulmonaires (GERM"O"P) in France. All 15 women (60 +/- 6 yr of age) fulfilled the following inclusion criteria: (1) radiation therapy to the breast within 12 mo, (2) general and/or respiratory symptoms lasting for at least 2 wk, (3) lung infiltrates outside the radiation port, and (4) no specific cause. The patients presented with fever, nonproductive cough, mild dyspnea, and peripheral alveolar opacities on chest radiograph with a characteristic migratory pattern. In five patients, BOOP was found at lung pathologic analysis. In all the patients dramatic improvement was obtained with corticosteroids, but relapses occurred in 12 patients while tapering or after stopping corticosteroids. This report demonstrates that a characteristic BOOP syndrome may occur after radiation therapy to the breast, including tangential radiation to the lung, thus suggesting that radiation therapy may prime the development of BOOP.

Aged↗
PubMed1998

Hypoxia reduces endothelin production by rat alveolar type II cells in primary culture.

The purpose of the study was to describe endothelin (ET) production and to characterize the effect of hypoxia on preproendothelin-1 (preproET-1) messenger ribonucleic acid (mRNA) expression and ET secretion by rat type II pneumocytes in vitro. Rat type II pneumocytes were incubated in a sealed chamber containing a normoxic (21% O2) or hypoxic (1% O2) atmosphere for increasing durations. Immunoreactive ET (irET) was measured in cell supernatants using a radioimmunoassay. Rat preproET-1 mRNA was detected by Northern blot. Rat type II pneumocytes expressed preproET-1 mRNA, contained irET and secreted irET in a time-dependent manner. ET secretion was dependent on de novo ribonucleic acid (RNA) and protein synthesis. Hypoxia decreased irET secretion by 27% and reduced the steady-state level of preproET-1 mRNA by 60% whereas intracellular irET concentration was unchanged. Inhibition was partially reversible with the return to a normoxic atmosphere. Inhibition of nitric oxide synthesis did not prevent the inhibitory effect of hypoxia. In conclusion, rat type II pneumocytes in primary culture secreted immunoreactive endothelin and expressed preproendothelin-1 messenger ribonucleic acid. Hypoxia reversibly reduced endothelin-1 production through a reduction of the steady-state preproendothelin-1 messenger ribonucleic acid level. Nitric oxide synthesis did not mediate the inhibitory effect of hypoxia.

Animals↗
PubMed1998

Neutrophil alveolitis in bronchioloalveolar carcinoma: induction by tumor-derived interleukin-8 and relation to clinical outcome.

Tumor infiltrate, predominantly constituted by lymphocytes, may represent an important prognostic factor in bronchioloalveolar carcinoma (BAC), in addition to tumor extension and histological type. In the present study, we determined the presence, the origin, and the prognostic importance of neutrophils that also participate in leukocyte infiltrates of BAC. Neutrophil alveolitis was determined immunohistochemically in both lung biopsies and bronchoalveolar lavage (BAL) fluid samples from 29 patients with histologically proved BAC. The local expression of interleukin (IL)-8 was determined by immunohistochemical and immunoenzymatic techniques. Neutrophil counts were analyzed in relation to the clinical outcome of patients by the Kaplan-Meier method and Cox's univariate and stepwise multivariate models. Lymphocytes and neutrophils dominated the inflammatory cell population in the lower respiratory tract of patients with BAC. Neutrophils were located mainly in the alveolar lumen and seldom in alveolar wall whereas lymphocytes were exclusively present in alveolar wall. A relationship was observed between the number of neutrophils and the level of IL-8 in BAL fluid suggesting the involvement of that chemokine in neutrophil recruitment. The tumor cells were the predominant cells that appeared to express IL-8 by immunolocalization. The presence of increased numbers of neutrophils was significantly associated with a poorer outcome in patients with BAC (P = 0.02). In a multivariate analysis, the neutrophil percentage in BAL fluid was an independent predictor of clinical outcome. The risk of death was increased substantially (rate ratio, 5.2; 95% confidence interval, 1.1 to 24.7) among patients with BAL neutrophil percentage of > or = 39% (median of the distribution) as compared with the others. In BAC, neutrophils accumulate in the alveolar lumen. Elaboration of IL-8 by tumor cells may be responsible for this event, which is associated with a significantly higher risk of death.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1998

Pulmonary tuberculosis: computed tomography and high-resolution computed tomography patterns in patients who are either HIV-negative or HIV-seropositive.

To compare findings of active pulmonary tuberculosis on computed tomography (CT) and high-resolution computed tomography (HRCT) scans in patients without the human immunodeficiency virus (HIV) and patients with HIV, and to define the spectrum of pulmonary tuberculosis in patients with HIV according to the CD4 T cell status, 76 patients (47 patients without HIV and 29 patients with HIV) with newly diagnosed pulmonary tuberculosis were studied retrospectively. The diagnosis of active pulmonary tuberculosis was based on acid-fast bacilli (AFB) in sputum culture. All patients underwent CT within 1 month of diagnosis. Patients with HIV demonstrated significantly less cavitation and bronchial wall thickening (24% vs. 49% [p < 0.05]; and 14% vs. 45% [p < 0.01], respectively) than the combined group of patients with HIV. Centrilobular nodules were significantly less common in patients without HIV (14% vs. 45%, p < 0.05). Lymphadenopathy with low attenuation centers was significantly less frequent in the patients with HIV (3% vs. 15%, p < 0.05). In patients with HIV, cavitation, lymphadenopathy, as well as the the number of nodules and the number of lobes involved correlated well with the CD4 levels. Two patients with less than 50 CD4 T cells/mm3 had normal chest CT results. Atypical chest CT patterns are frequently encountered in patients with HIV. Knowledge of these CT patterns may assist in the diagnosis and follow-up of patients with HIV with known or suspected pulmonary tuberculosis.

Adult↗
PubMed1997

[Pneumopathy caused by minocycline].

BACKGROUND: Minocycline has been identified as a pathogenic agent in drug-induced pneumonia. We report a new case. CASE REPORT: A 38-year-old female asthmatic patient was given minocycline (100 mg/j) for facial acne. She was allergic to penicillin. Other treatments were theophylline, salbutamol and inhaled budesonide. Severe bilateral hypoxemia pneumonia developed with high eosinophil blood counts within a few days of treatment onset. The lung disease regressed with minocycline withdrawal. DISCUSSION: This case is exceptional because the minocycline-induced lung disease continued to progress despite high-dose corticosteroids in this asthmatic patient.

Adult↗
PubMed1997

High frequency of a deletion polymorphism of the angiotensin-converting enzyme gene in asthma.

BACKGROUND: An insertion-deletion polymorphism of the angiotensin-converting enzyme (ACE) gene has been shown to be associated with levels of ACE. Because ACE is heavily expressed in the lungs and plays a key role in the metabolism of angiotensin II and bradykinin, which are potentially involved in the pathogenesis of asthma, we tested the hypothesis of an association between the polymorphism of the ACE gene and asthma. METHODS: Seventy-nine patients with asthma, 54 healthy subjects, and 33 patients with nonasthmatic lung disease were studied. Pulmonary function tests were performed in patients with asthma, and the ACE genotypes were determined in all subjects by the polymerase chain reaction. RESULTS: The ACE genotype distribution was similar in healthy subjects and in patients without asthma. By contrast, the population of patients with asthma was characterized by a higher prevalence of the DD genotype of ACE (odds ratio, 2.09; 95% confidence interval, 1.05 to 4.16; p = 0.023). No difference in pulmonary function test results was detected in asthmatic patients according to the distribution of ACE genotypes. CONCLUSION: This study reports an association between the DD genotype of ACE and asthma, which is not related to the degree of airway obstruction. These results need to be confirmed by a larger case-control study.

Adult↗