Sadafumi Ono

A Therapeutic Approach to Roentgenographically Occult Squamous Cell Carcinoma of the Lung

The significance of limited resections, including wedge resection and segmentectomy, remains controversial because of their curability rates. In the current study, the objective was to determine a strategy for the treatment of patients with roentgenographically occult bronchogenic squamous cell carcinoma (ROSCC) based on the pathologic findings from 184 patients with ROSCC who underwent resection.

Vasoactive intestinal peptide causes nitric oxide-dependent pulmonary vasodilation in isolated rat lung.

Vasoactive intestinal peptide (VIP) is one of the chief neurotransmitters of nonadrenergic noncholinergic nerve fibers. In this study, we investigated the effect of VIP on the pulmonary circulation in isolated perfused rat lungs. Baseline pressures of the pulmonary artery for the isolated rat lungs were not affected by 3 x 10(-8) M VIP. VIP caused dose-dependent pulmonary vasodilation when the pulmonary vascular bed was constricted with 20 mM KCl. This vasodilative effect of VIP was inhibited by 1 x 10(-6) M L-n omega-nitro-arginine, an endothelium-derived relaxing factor (nitric oxide) inhibitor, and was restored by the addition of 10(-4) M L-arginine, a substrate of nitric oxide. VIP also caused suppression of the ANG II pressor response, and this VIP-induced suppressive effect was reduced when L-N omega-nitro-arginine or 3 x 10(-6) M meclofenamate was added to the perfusate. These results indicate that VIP causes pulmonary vasodilation in isolated rat lung and suggest the possible involvement of NO and/or cyclooxygenase metabolites in VIP-induced pulmonary vasodilation.

Functional evaluations for pulmonary resection for lung cancer in octogenarians. Investigation from postoperative complications.

We have reviewed the records of our twenty-four patients aged 80 years or older who underwent lung resections for bronchogenic carcinoma between 1983 and 1997 in our department. Eighteen patients were male and six were female. Adenocarcinoma was the histology in more than half of the cases (13 patients), along with 8 squamous cell carcinoma, 2 large cell carcinoma, and one small cell lung carcinoma. More than single lobectomy was performed in each patient. Unilateral pulmonary occlusion tests were employed in patients with impairment in pulmonary functions. Every patient, who underwent the unilateral pulmonary occlusion test, was certified that the total pulmonary vascular resistance index during unilateral pulmonary arterial occlusion test was less than 700 dyne.sec.cm-5.m2. Postoperative cardiovascular complications, such as paroxysmal atrial tachycardia, premature atrial contraction, premature ventricular contraction or atrial fibrillation, were seen in 10 patients. Postoperative respiratory complications, namely, sputa retention, retained secretions or atelectasis, were seen in 7 patients. The extent of dissection of mediastinal lymph node was not correlated to the postoperative pulmonary complications. However, the incidence of arrhythmias in the patients who received R2 mediastinal lymphnode dissection was much higher than in those who received R1 or R0 dissection. Complete blood counts and serum biochemical analysis performed at about three weeks after operations revealed leukocytosis and increases in levels of serum transaminase. These phenomena in leukocytosis and increases in the levels of serum transaminase in these patients were similar to those in younger patients. There was no operative death. We conclude that some patients over 80 years are candidates for lung resection after careful preoperative cardiopulmonary evaluation.

Difference in the effects of low temperatures on the tension of human pulmonary artery and vein ring segments.

Background: Although limited data suggest that pulmonary flushing with organ preservation solutions should not be performed at too low temperatures, the influence of temperature on pulmonary vascular tone is unclear. Objective: The purpose of this study was to examine the effect of low temperatures of the tension of human pulmonary artery and vein ring segments and the vascular resistance of perfused rat lungs. Methods: 5 sets of human pulmonary artery and vein ring segments were suspended from a force displacement transducer at 37, 24 and 8°C, and the effect of 30 mM K+ on the tension was monitored. The effect of 30 mM K+ on vascular resistance was also examined at low temperatures in 5 perfused rat lungs. Results: Pulmonary artery segments dilated at 24°C, and more significant vasodilatation was observed at 8°C. In contrast, there was a significant constriction of pulmonary veins at 8°C. Vasoconstriction induced by 30 mM K+ at 37°C was significantly inhibited at low temperatures in both pulmonary arteries and veins. In rat lungs, perfusion at 8°C caused a significant increase in pulmonary vascular resistance, even though no further increase was observed in the presence of 30 mM K+. Conclusions: Our data indicate that pulmonary arteries dilate and the veins constrict at 8°C and may increase pulmonary vascular resistance. We conclude that the different effect of low temperatures between pulmonary arteries and veins may explain why pulmonary vascular flushing with organ preservation solutions at room temperature is more satisfactory.

Superoxide anion mediates pulmonary vascular permeability caused by neutrophils in cardiopulmonary bypass.

During cardiopulmonary bypass (CPB), neutrophils (PMNs) may be stimulated by shear stress which could contribute to the pulmonary injury that occurs after CPB. To elucidate whether mechanically stimulated PMNs increase pulmonary vascular permeability, measured as the pulmonary filtration coefficient (K) and pulmonary vascular resistance, and to elucidate whether superoxide anion mediates this increase, we assessed the effects of stimulated and unstimulated PMNs, and of superoxide dismutase (SOD) on K and resistance in isolated perfused lungs from Sprague-Dawley rats. PMNs were stimulated by gentle agitation in a glass vial for 10s. Lungs perfused with the stimulated PMNs, being the stimulated group (n=6), elicited a 5-fold increase in the filtration coefficient compared with lungs perfused with unstimulated cells, being the unstimulated group (n=6). This increase in filtration was completely blocked by the pre-incubation of stimulated PMNs with CD18 monoclonal antibody, being the Ab group (n=6), and also by superoxide dismutase, being the SOD group (n=6). Pulmonary vascular resistance was not increased by stimulated PMNs, and the accumulation of stimulated PMNs was not blocked by SOD. These findings suggest that stimulated PMNs increaseK and that superoxide anion may injure the pulmonary vascular endothelial cells.

Role of neutrophil migration on increased pulmonary microvascular permeability.

The precise role of neutrophils in adult respiratory distress syndrome is not yet clear. Endotoxin administration is known to induce the permeability pulmonary edema with neutrophil migration into alveolar spaces. Leukotriene B4 is known as a strong chemotactic factor. To clearify the roles of neutrophils on pulmonary microvascular injury, we compared the effects of endotoxin and leukotriene B4 on lung lymph dynamics and neutrophil migration. Endotoxin caused increase in microvascular permeability and migration of neutrophils into alveolar spaces.Whereas leukotriene B4 did not affect lung microvascular permeability. Neutrophils in broncho-alveolar lavage fluid after leukotriene B4 administration increased to the same value as which after endotoxin administration. These results suggest that the neutrophil migration into alveolar spaces is not essential to develop the permeability pulmonary edema.