PubMed Health⌕ Search

Biomedical subjects

F Basset

Publications and source records attributed to F Basset.

At least 19 recordsLinked to original sources
PubMed2005

Effect of fluid ingestion on neuromuscular function during prolonged cycling exercise.

OBJECTIVES: To investigate the effects of fluid ingestion on neuromuscular function during prolonged cycling exercise. METHODS: Eight well trained subjects exercised for 180 minutes in a moderate environment at a workload requiring approximately 60% maximal oxygen uptake. Two conditions, fluid (F) and no fluid (NF) ingestion, were investigated. RESULTS: During maximal voluntary isometric contraction (MVC), prolonged cycling exercise reduced (p<0.05) the maximal force generating capacity of quadriceps muscles (after three hours of cycling) and root mean square (RMS) values (after two hours of cycling) with no difference between the two conditions despite greater body weight loss (p<0.05) in NF. The mean power frequency (MPF) for vastus lateralis muscle was reduced (p<0.05) and the rate of force development (RFD) was increased (p<0.05) only during NF. During cycling exercise, integrated electromyographic activity and perceived exertion were increased in both conditions (p<0.05) with no significant effect of fluid ingestion. CONCLUSIONS: The results suggest that fluid ingestion did not prevent the previously reported decrease in maximal force with exercise duration, but seems to have a positive effect on some indicators of neuromuscular fatigue such as mean power frequency and rate of force development during maximal voluntary contraction. Further investigations are needed to assess the effect of change in hydration on neural mechanisms linked to the development of muscular fatigue during prolonged exercise.

Adult↗
PubMed1999

[Dynamic studies of Langerhans cell histiocytosis cells. Their contribution to the current concept of the disease. Report of a series of 38 cases].

In vitro explantation of 38 fragments of eosinophilic granuloma of bones was attempted. A satisfactory growth was obtained in nearly 90% of cases. This short-term culture maintained the ultrastructural characteristics and, to a lesser extent, the cytochemical features of the Langerhans cells, confirming the Langerhans cell origin of this cell proliferation. In addition, this procedure was able to demonstrate an immunodependent erythrophagocytosis (3/3) and a preferential fixation of labelled precursors (Glycerol, choline of lipid metabolism as well as labelled dopamine (2/2). All attempts to obtain a permanent cell line and graft to nude mice (even irradiated) failed. Under the in vitro conditions, the Langerhans cells do not divide up but can be readily identified up to 2 or 3 weeks. The contrast between the evident in vivo proliferation and the in vitro quiescent state suggests that some undetermined growth-factors targeted to the Langerhans cell system are missing in our commonly used culture media. The in vitro culture procedure could be of some help to their identification.

Animals↗
PubMed1998

Langerhans cell histiocytosis research. Past, present, and future.

This article reviews the various investigative events that led to the endorsement of the term Langerhans cell histiocytosis for the various clinicopathologic conditions previously called Hand-Schüller-Christian disease, Abt-Letterer-Siwe disease, eosinophilic granuloma of bone, and histiocytosis X. The different denominations reflect the changing conceptual approaches to the so-called reticuloendothelial system and the successive acquisition of new ultrastructural and immunocytochemical data.

Adult↗
PubMed1998

Target speed alone influences the latency and temporal accuracy of interceptive action.

When intercepting a mobile object or an apparent movement, participants show a temporal bias. They are in advance when dealing with a slow-moving stimulus and late with a fast-moving one. We studied participants intercepting an apparent movement by sliding a disk on a table. Using a fast and a slow stimulus speed, we varied three factors: duration of presentation of the stimulus, distance covered by the stimulus, and speed context (constant or varied) of stimulus presentation. In addition to the temporal bias, spatial accuracy and kinematic measures were collected. The temporal bias created by speed was evident across all three factors. Speed, in addition to strongly determining the temporal bias, significantly affected the throwing strategy adopted by the participants, as revealed by latency, movement time, and disk trajectory duration.

Adult↗
PubMed1995

Significance of early intra-alveolar fibrotic lesions and integrin expression in lung biopsy specimens from patients with idiopathic pulmonary fibrosis.

To study the pulmonary structural remodeling in idiopathic pulmonary fibrosis (IPF), ultrastructural, immunohistochemical, and light microscopic morphometric observations were made on 11 pulmonary biopsy specimens from patients with IPF. The morphometric study was done using sequentially cut tissue sections stained for keratin-alcian blue periodic acid-Schiff (PAS), fibronectin, and type IV collagen-alcian blue PAS. Most of the early fibrotic lesions, which were alcian blue- and fibronectin-positive, were intra-alveolar in location. Intra-alveolar fibrosis is considered to be essential for the fusion of alveolar walls in IPF. A strong reaction for integrin alpha 5 beta 1 and vinculin was found in epithelial cells and mesenchymal cells in areas of intra-alveolar fibrosis. These findings show that these cells are active in adhesion to fibronectin in areas of early intra-alveolar fibrosis. Some of the epithelial cells, including cytoplasmic hyaline-laden cells, showed evidence of inadequate adhesion to the extracellular matrix, and this may constitute one of the mechanisms of progression of fibrosis in IPF.

Adult↗
PubMed1995

Evaluation of bronchoscopic techniques for the diagnosis of nosocomial pneumonia.

To compare the usefulness of specimens obtained by bronchoalveolar lavage (BAL) and using a protected specimen brush (PSB) in the diagnosis of nosocomial pneumonia, both procedures were performed via fiberoptic bronchoscopy just after death in a series of 20 ventilated patients who had not developed pneumonia before the terminal phase of their disease and who had no recent changes in antimicrobial therapy. These results were compared with both histologic and microbiologic postmortem lung features in the same area. The total number of bacteria obtained by culture of lung segments and the latters' histologic grade were closely correlated (rho = 0.79, p < 0.0001). PSB and BAL quantitative culture results were strongly correlated with lung tissue values (rho = 0.67 and 0.75, respectively; p < 0.0001). Using discriminative values of > or = 10(3) and > or = 10(4) bacteria/ml to define positive PSB and BAL cultures, respectively, these techniques identified lung segments yielding > or = 10(4) bacteria/g tissue with sensitivities of 82 and 91% and specificities of 89 and 78%, respectively. Moreover, upon direct observation, the percentage of BAL cells containing intracellular bacteria was closely correlated with the total number of bacteria obtained from corresponding lung samples (p < 0.001). These findings indicate that bronchoscopic PSB and BAL samples very reliably identify both qualitatively and quantitatively microorganisms present in lung segments with bacterial pneumonia, even when the infection develops as a superinfection in a patient already receiving antimicrobial treatment for several days.

Aged↗
PubMed1993

[Langerhans cell pulmonary granulomatosis].

Langerhans' cell granulomatosis, formerly known as histiocytosis X include several granulomatosis of unknown aetiology. The original pathological finding is a Langerhans' cell granuloma. Recent progress has improved our understanding of the pathogenesis of this group of diseases and facilitated the diagnosis. We describe here the cell populations involved, the general pathology of Langerhans' cells, proposed pathogenesis, and the relationship between Langerhans' cell pulmonary granulomatosis and other localizations of Langerhans' cell granulomatosis. Finally, the clinical manifestations, elements of diagnosis and changing attitudes of current therapy are discussed.

Bronchoalveolar Lavage Fluid↗
PubMed1991

[Pulmonary dendritic cells].

The dendritic cells were initially described in lymphoid organs and have been recently shown in the normal human lung at the level of the bronchioles, preferentially in the peribronchiolar connective tissue and in the alveolar parenchyma. Langerhans cells, which constitute a sub-population amongst the dendritic cells are equally present, but virtually exclusively limited to the bronchiolar epithelium. The pulmonary Langerhans cells probably derive from dendritic cells as in the skin. The number and state of differentiation of pulmonary dendritic cells vary as a function of the epithelial microenvironment which seems necessary in the differentiation of dendritic cells into Langerhans cells. Langerhans cells are frequently seen in zones of alveolar hyperplasia and/or alveolar metaplasia induced by tobacco or by inflammatory lesions. Dendritic cells and Langerhans cells have a potent capacity for presenting an antigen to lymphocytes. Their presence in the normal lung and their differentiation in the course of certain pathological pulmonary processes strongly suggest that they have a significant role in the pulmonary immune response as well as in the pathogenesis of certain diseases.

Dendritic Cells↗
PubMed1990

Role of elastic fiber degradation in emphysema-like lesions of pulmonary lymphangiomyomatosis.

To study the pulmonary structural remodeling in pulmonary lymphangiomyomatosis, electron microscopy and light and electron microscopic immunohistochemical observations for elastin and alpha 1-antitrypsin were performed on five open lung biopsy samples. Lung specimens showed emphysema-like changes in areas of abnormally accumulated smooth muscle cells. In the alveolar walls having accumulated smooth muscle cells, elastic fibers were decreased in number, disrupted, granular, and occasionally accumulated. Ultrastructurally, elastic fibers in areas of smooth muscle cell accumulation showed poorly outlined amorphous components and a few microfibrils, and occasionally showed electron-dense granular deposits in and around the amorphous components. Spiraling collagen fibrils were frequently found associated with these abnormal elastic fibers. Immunohistochemistry for elastin showed even staining of amorphous components of elastic fibers in the areas of smooth muscle cell accumulation. alpha 1-Antitrypsin was also detected evenly in amorphous components of elastic fibers in the areas of smooth muscle cell accumulation. It is proposed that the emphysema-like lesions of lymphangiomyomatosis are mediated by the degradation of elastic fibers, and these degraded elastic fibers are related to an imbalance of the elastase/alpha 1-antitrypsin system similar to the probable pathogenesis of emphysema.

Adult↗
PubMed1990

Abnormal epithelial cells recovered by bronchoalveolar lavage: are they malignant?

The recovery of neoplastic cells by bronchoalveolar lavage is useful in the diagnosis of lung cancer. Abnormal epithelial cells can also be recovered from patients with interstitial lung diseases who do not have cancer, and therefore the usefulness of lavage in the diagnosis of malignancy in this setting is unknown. In this study, we evaluated the diagnostic significance of abnormal lavage cells recovered from patients with diffuse parenchymal abnormalities and compared the usefulness of standard cytologic assessment, correlation with clinical features, and immunocytochemical staining for carcinoembryonic antigen (CEA) in identifying abnormal cells that are truly malignant. Thirty of 2,314 patients had atypical lavage cells, but in only nine was lung cancer demonstrated. Although most patients with clinical suspicion of malignancy had lung carcinoma (six of seven), one such patient did not have cancer, and three were shown to have unsuspected carcinoma. Cytologic criteria identified definitely malignant cells in only four of nine patients with lung cancer, indicating that the approach is not sensitive. Immunostaining of abnormal cells with anti-CEA antibodies proved helpful. All patients with lung malignancy had CEA+ cells (n = 9), and no patient whose abnormal cells were CEA- proved to have cancer (n = 17). Because only nine of 13 patients with CEA+ cells had lung malignancy, the test is not diagnostic, but it appears to limit the need for further evaluation to a smaller group of patients in whom cancer is likely to be present. When used together, cytopathologic findings, detection of CEA by immunocytochemical techniques, and clinical correlates proved useful in diagnosis of lung malignancy, but further improvements are still needed to improve diagnostic accuracy.

Bronchoalveolar Lavage Fluid↗
PubMed1990

Intraluminal fibrosis and elastic fiber degradation lead to lung remodeling in pulmonary Langerhans cell granulomatosis (histiocytosis X).

To evaluate the morphogenesis of lung remodeling in pulmonary Langerhans cell granulomatosis (LCG; previously called histiocytosis X or eosinophilic granuloma), lung tissues obtained by open biopsy from 62 patients with pulmonary LCG were studied by light and electron microscopy. Tissues from 20 patients were also studied by immunohistochemical methods for the detection of fibronectin, elastin, and S-100 protein, and samples from six patients were studied using OKT6 monoclonal antibody. In early stages of pulmonary LCG, the epithelial lining cells were detached and Langerhans cells, inflammatory cells, and myofibroblasts migrated into intraluminal spaces through gaps in the epithelial basement membranes in and around the granulomatous lesions. In late stages, intraluminal fibrosis led to obstruction of alveolar spaces and airways and to coalescence of alveolar walls in and around the granulomatous lesions. Adjacent to these lesions, irregularly dilated alveoli were found with degraded and disrupted elastic fibers. Together, these observations suggest that intraluminal fibrosis and elastic fiber degradation are important processes of lung remodeling in pulmonary LCG.

Antibodies, Monoclonal↗
PubMed1989

Cigarette smoking-induced changes in the number and differentiated state of pulmonary dendritic cells/Langerhans cells.

To evaluate the effect of cigarette smoking on the number, distribution, and differentiated state of dendritic cells (DC) and Langerhans cells (LC) in the human lung, we have quantitated the number of these cells present in the bronchioles and alveolar parenchyma of lung tissue from nonsmokers and cigarette smokers using anti-CD1 monoclonal antibodies which react preferentially with DC (M241) and LC (T6). M241+ DC were found in the bronchiolar submucosa and alveolar parenchyma of nonsmokers; T6+ LC were present within the bronchiolar epithelium. Cigarette smoking was associated with a twofold increase in the total number of cells of DC/LC lineage and a 30-fold increase in the number of T6+ cells, many of which contained Birbeck granules (LC), present in the alveolar parenchyma. Most LC found in the parenchyma of smokers were observed in close association with areas of alveolar type II pneumocyte hyperplasia. Cigarette smoking did not change the number of differentiated state of cells of DC/LC lineage within the bronchioles. Both DC and LC are present in the human lung. Cigarette smoking has an important effect on the number, distribution, and differentiated state of these cells, which may explain why most adult patients who develop Langerhans cell granulomatosis are smokers.

Adult↗
PubMed1989

Cellular composition of periapical granulomas and its function. Histological, immunohistochemical and electronmicroscopic study.

Periapical granulomas have been investigated histologically, immunohistologically using polyclonal and monoclonal antibodies, as well as electronmicroscopically. Lesions were formed by inflammatory granulation tissue frequently with foci of purulent exudation and fibrosis. Most numerous were plasma cells usually in cellular regions of the granulation tissue where they were tightly pressed. Of other cellular types were numerous lymphocytes, fibroblasts, less frequent were macrophages, scattered granulocytes and mast cells. More than a half of the plasma cells were IgG positive, about 20% IgA positive, up to 10% IgM, rarely IgE and sporadically IgD positive cells. In the vascular walls and their surrounding as well as in the phagocytes fine granular to granular positivities of C3 and C4 components of the complement were present. The majority of lymphocytes beared markers of T lymphocytes of which the T-suppressor markedly prevailed over the T-helper lymphocytes. In electron microscopy the plasma cells were most frequent. They were usually close to each other, sometimes with a disintegrated cytoplasmic membrane and non-damaged organelles being free around the nucleus. Mast cells were numerous and did not show any signs of marked degranulation. Rich production of immunoglobulins as well as the presence of IgG and IgM positive material in phagocytes, and the presence of positivities of the C3 and C4 components of the complement in the surrounding of the vessels and in phagocytes on the other hand supported the presumption that immune complexes participate in the pathogenesis of periapical granulomas. In spite of the presence of the IgE producing cells the morphological picture of mast cells did not suggest the presence of anaphylactic reaction in periapical lesions. Diffuse distribution of T lymphocytes, moreover with the prevalence of T-suppressor/cytotoxic over T-helper lymphocytes and not numerous macrophages in the inflammatory infiltrates did not suggest the participation of a typical cell-mediated immunity reaction in the development of periapical granulomas. Numerous T-suppressor/cytotoxic lymphocytes and low numbers of macrophages can be important factors of the chronicity of periapical inflammatory diseases.

Antibodies, Monoclonal↗
PubMed1987

In situ characterization of cells in periapical granuloma by monoclonal antibodies.

Monoclonal antibodies were used in histopathologic and immunohistologic studies of periapical granulomas. In cellular zones, plasma cells and lymphocytes predominated, with variable numbers of fibroblasts, macrophages, and polymorphonuclear leukocytes. Labeling with monoclonal antibodies disclosed relatively infrequent, usually scattered macrophages. Plasma cells were numerous and frequently clumped. The vast majority of lymphocytes were T cells, scattered individually or in small groups of three or four cells and dispersed throughout the granulomas without any topographic predilection, with prevalence of T-suppressor/cytotoxic cells over T-helper/inducer cells. Our findings of numerous plasma cells, which were in agreement with descriptions of numerous immunoglobulin-producing cells by other authors, imply the participation of antibody-mediated immune reactions in periapical granulomas. The presence of cell-mediated immunity, in spite of numerous T cells, could not be confirmed.

Adolescent↗