Interleukin-6 changes deformability of neutrophils and induces their sequestration in the lung.

Interleukin-6 (IL-6) is an important mediator of both the hepatic and the bone marrow components of the acute-phase response. Previous studies from our laboratory have shown that cells released into the circulation from the marrow preferentially sequester in the lung. The present study was designed to examine the mechanism of this sequestration using a single dose of recombinant human IL-6 to stimulate the marrow in rabbits.

The effect of repeated exposure to particulate air pollution (PM10) on the bone marrow.

Studies have shown that exposure to ambient particulate matter is related to an increased cardiopulmonary morbidity and mortality. The present study was designed to measure the effect of repeated exposure to urban air particles (PM10) on the rate of production and release of polymorphonuclear leukocytes (PMN) from the bone marrow into the peripheral blood. Rabbits exposed to PM10 (5 mg) twice a week for 3 wk, were given a bolus of 5'-bromo-2'-deoxyuridine (BrdU) to label dividing cells in the marrow that allows us to calculate the transit time of PMN in the bone marrow mitotic and postmitotic pools.

Expression of the cell adhesion molecules on leukocytes that demarginate during acute maximal exercise.

The pulmonary vascular bed is an important reservoir for the marginated pool of leukocytes that can be mobilized by exercise or catecholamines. This study was designed to determine the phenotypic characteristics of leukocytes that are mobilized into the circulation during exercise. Twenty healthy volunteers performed incremental exercise to exhaustion [maximal O2 consumption (VO2 max)] on a cycle ergometer.

Cigarette smoking causes sequestration of polymorphonuclear leukocytes released from the bone marrow in lung microvessels.

Studies from our laboratory have shown that chronic cigarette smoke exposure causes a neutrophilia associated with a shortening of the mean transit time of polymorphonuclear leukocytes (PMN) though the postmitotic pool of the marrow. The present study was designed to test the hypothesis that PMN newly released from bone marrow by smoke exposure preferentially sequestered in pulmonary microvessels. The thymidine analogue 5'-bromo-2'-deoxyuridine (BrdU) was used to label dividing PMN in the marrow of rabbits; their appearance in the circulation was measured using immunocytochemistry, and their sequestration in lung tissue was determined using standard morphometric techniques.

The expression of adhesion molecules in cigarette smoke-induced airways obstruction.

Cigarette smoking produces peripheral airway inflammation in all smokers, and chronic airways obstruction in approximately 20% of heavy smokers. The present study was designed to test the hypothesis that airways obstruction is related to changes in the expression of adhesion molecules involved in the recruitment of cells to sites of inflammation in the lung. Freshly resected lungs from heavy smokers with airways obstruction (n = 10) and from heavy smokers with normal lung function (n = 10) were collected in the operating room, inflated with optimal cutting temperature (OCT) medium and frozen over liquid nitrogen.