The use of positive pressure mechanical ventilation can cause ventilator-induced lung injury (VILI). We hypothesized that hyperoxia in combination with large tidal volumes (VT) would accentuate noncardiogenic edema and neutrophil infiltration in VILI and be dependent on stretch-induced macrophage inflammatory protein-2 (MIP-2) production. In rats ventilated with VT 20 ml/kg, there was pulmonary...

Both the anatomy and the mechanics of inflation of the alveoli, as presented in most textbooks of physiology, have been misunderstood and misrepresented. The typical representation of the acinus as a "bunch of grapes" bears no resemblance to its real anatomy; the alveoli are not independent little balloons. Because of the prevalence of this misconception, Laplace's law, as it applies to spheres...

AIM The aim of this prospective study was to evaluate the clinical pattern of post-extraction wound healing with a view to identify the types, incidence, and pattern of healing complications following non-surgical tooth extraction. STUDY DESIGN A total of 311 patients, who were referred for non-surgical (intra-alveolar) extractions, were included in the study. The relevant pre-operative infor...

The lungs serve the primary function of air-blood gas exchange in all mammals and in terrestrial vertebrates. Efficient gas exchange requires a large surface area that provides intimate contact between the atmosphere and the circulatory system. To achieve this, the lung contains a branched conducting system (the bronchial tree) and specialized air-blood gas exchange units (the alveoli). The con...

The lungs normally are ventilated with enough air to dilute the carbon dioxide produced by metabolism, so that the partial pressure of carbon dioxide (Pco,) in the alveoli is kept remarkably close to 40 mm. Hg. It is the alveolar ventilation and not the total amount of air going in or out of the mouth (or 'minute-volume') that determines the Pco2 because a varying proportion of the total ventil...

Calorie restriction, followed by ad libitum refeeding, results, respectively, in loss and regeneration of pulmonary alveoli. We now show 35% of alveoli are lost within 72 h of onset of calorie restriction ((2/3) decreased daily chow intake), and an additional 12% of alveoli are lost over a subsequent 12 days of calorie restriction. Tissue necrosis was not seen. Within 72 h of refeeding, after 1...

Aging is associated with morphometric changes in the lung that lead to decreased lung function. The nonhuman primate lung has been shown to have similar architectural, morphological, and developmental patterns to that of humans. We hypothesized that the lungs of rhesus monkeys age in a pattern similar to human lungs. Thirty-four rhesus monkeys from the California National Primate Research Cente...

In a previous simulation, our laboratory demonstrated that the flow induced by a rhythmically expanding and contracting alveolus is highly complex (Haber S, Butler JP, Brenner H, Emanuel I, and Tsuda A, J Fluid Mech 405: 243-268, 2000). Based on these earlier findings, we hypothesize that the trajectories and deposition of aerosols inside the alveoli differ substantially from those previously p...

RATIONALE In clinical trials, homogeneous emphysema patients have responded well to upper lobe volume reduction but not lower lobe volume reduction. MATERIALS/METHODS To understand the physiological basis for this observation, a computer model was developed to simulate the effects of upper and lower lobe lung volume reduction on RV/TLC and lung recoil in homogeneous emphysema. RESULTS Patie...