Biomedical subjects

J M Smiéjan

Publications and source records attributed to J M Smiéjan.

4 recordsLinked to original sources

PubMed1991

Spontaneous release of granulocyte colony-stimulating factor (G-CSF) by alveolar macrophages in the course of bacterial pneumonia and sarcoidosis: endotoxin-dependent and endotoxin-independent G-CSF release by cells recovered by bronchoalveolar lavage.

Because granulocyte colony-stimulating factor (G-CSF) is known to induce granulopoiesis and activate mature neutrophils, this factor could be important in determining the number and functional activity of neutrophils at sites of lung disease. The purpose of this study was to evaluate the ability of lung immune and inflammatory cells to produce G-CSF, and to seek evidence for the spontaneous production of this factor by cells recovered by lavage from controls and patients with lung diseases in which neutrophils may play a pathogenetic role. Lavage cells from controls produced little G-CSF spontaneously. Alveolar macrophages (AM), but not lymphocytes, produced large amounts following endotoxin stimulation. Lavage cells from patients with respiratory failure associated with bacterial pneumonia, but not those with respiratory failure from noninfectious causes, spontaneously released G-CSF (32 +/- 24 and less than 1 U/10(6) AM, respectively). Lavage cells from five of 15 patients with sarcoidosis and one of five patients with diffuse pulmonary fibrosis also spontaneously released G-CSF, which could not be explained by endotoxin exposure. The release of G-CSF by endotoxin-dependent and -independent mechanisms could play a role in the recruitment and activation of neutrophils in bacterial pneumonia and participate in the pathogenesis of some interstitial lung diseases.

Adult↗

PubMed1990

Expression of surface antigens distinguishing "naive" and previously activated lymphocytes in bronchoalveolar lavage fluid.

Studies in animals suggest that the initial activation of unprimed ("naive") T lymphocytes by inhaled antigens may occur outside the lung with later recruitment to the lung. If this is true all lymphocytes present in the lung should show evidence of prior activation. To test this hypothesis for lymphocytes present on the alveolar surface, the expression of surface antigens, which distinguish unprimed from previously activated cells (CD45RA, CD29, Leu-8), were measured on T lymphocytes recovered from blood and bronchoalveolar lavage fluid from normal subjects and patients with sarcoidosis. Few T lymphocytes from the lavage fluid of normal subjects and patients with sarcoidosis expressed the Leu 8+ or CD45RAbright phenotype expected for "naive" cells; more cells had the CD29dull phenotype expected for "naive" cells, though five of eight subjects had under 2% of such cells. These findings support the conclusion that the only T lymphocytes present on the surface of the respiratory tract are those recognising antigens that have been previously encountered by the individual. Further studies are required to determine whether "naive" T lymphocytes are present in other lung compartments.

Adult↗

PubMed1986

Sarcoid-like lymphocytosis of the lower respiratory tract in patients with active Crohn's disease.

To re-evaluate the relationship between Crohn's disease and sarcoidosis, we compared the numbers and types of cells recovered by bronchoalveolar lavage from normal volunteers and patients with Crohn's disease, with other forms of inflammatory bowel disease, and with sarcoidosis. Patients with Crohn's disease, but not patients with other inflammatory bowel disorders, had an increase in the number of T lymphocytes on the surface of the lower respiratory tract similar to that seen in patients with sarcoidosis. As in sarcoidosis, this lymphocytosis results from an expansion of the T4+ T-lymphocyte subset, is characteristic of patients with active disease only, and is not associated with similar abnormalities in the peripheral blood. Thus, patients with apparently localized Crohn's disease have sarcoid-like lymphocytosis of the lower respiratory tract, a finding that emphasizes the systemic nature of Crohn's disease and the disorder's close relationship to sarcoidosis.

Adolescent↗

PubMedDate not supplied

[Hyperthyroidism].

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Hyperthyroidism↗