Masayuki Chida

Effects of antiplatelet agents on pulmonary haemodynamic response to fMLP in endotoxin primed rats

Background: The interaction between neutrophils and platelets may be important in the modulation of pulmonary haemodynamics under systemic inflammatory conditions. A study was undertaken to examine whether antiplatelet agents inhibit platelet-neutrophil adherence and ameliorate the pulmonary haemodynamic response to fMLP by inhibiting thromboxane release in endotoxin primed lungs. fMLP stimulates neutrophils but not platelets; however, thromboxane synthesis in neutrophils is very low. Methods: Rats were pretreated with either cilostazol (300 mg/kg) or aspirin (50 mg/kg) before endotoxin priming (5 mg/kg). Platelets in the lung were identified by fluorescent immunohistochemistry. Platelet-neutrophil adherence was analysed by flow cytometry of the lung vascular flush. The effect of fMLP (10−6 M) on thromboxane release, lung weight (an indicator of pulmonary vasoconstriction), and lung filtration coefficient was determined in an isolated lung system perfused at a constant pressure difference. Results: Endotoxin induced platelet accumulation and platelet-neutrophil adherence in the lung capillary were completely inhibited by cilostazol and aspirin while neutrophil recruitment was not affected. The fMLP challenge caused a significant increase in thromboxane B2 levels in endotoxin primed lungs. The fMLP induced decrease in lung weight was enhanced by endotoxin priming (from −4.9 to −63.9 mg, 95% CI of mean difference −99.5 to −10.5 mg, p<0.05). The fMLP induced increase in the lung filtration coefficient was also enhanced by endotoxin priming (from 0.63 to 2.40 mg/min/cm H2O/g, 95% CI of mean difference 1.17 to 2.37 mg/min/cm H2O/g, p<0.05). Treatment with cilostazol and aspirin completely inhibited the enhanced pulmonary haemodynamic response to fMLP. Conclusion: The neutrophil–platelet interaction is of critical importance in the modulation of pulmonary haemodynamics via thromboxane.

Pulmonary mucinous cystadenocarcinoma: report of a case and review of the literature

A case of primary mucinous cystadenocarcinoma of the lung is presented. The patient was a 42-year-old woman with a 5-cm left lung mass. Left lower lobectomy was performed and analysis of a frozen section revealed mucinous cystadenocarcinoma. The tumor was a fibrous, walled cyst containing abundant mucinous material. Sparse groups of malignant cells were microscopically observed in pools of mucin; thus, the tumor resembled mucinous cystadenocarcinoma that occurs in the ovary, appendix, or pancreas. The tumor we found is a very rare intrapulmonary neoplasm that is differentiated from a metastatic lesion and mucinous bronchoalveolar carcinoma by its very different clinical course and prognosis.

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.