Tomonobu Koizumi

Positive Association of the Endothelial Nitric Oxide Synthase Gene Polymorphisms With High-Altitude Pulmonary Edema

Background—A defect of nitric oxide (NO) synthesis in the lung of high-altitude pulmonary edema (HAPE) has been suggested to contribute to its exaggerated pulmonary hypertension. Several polymorphisms have been identified in the gene encoding endothelial nitric oxide synthase (eNOS), which is a key enzyme responsible for NO synthesis, some of which were reported to be associated with vascular disorders. Methods and Results—We studied 41 HAPE-susceptible subjects (HAPE-s) and 51 healthy climbers (control group) in a Japanese population. We examined 2 polymorphisms of the eNOS gene, including the Glu298Asp variant and 27-base pair (bp) variable numbers of tandem repeats using polymerase chain reaction followed by restriction fragment length polymorphism. The Asp allelic frequency of the Glu298Asp variant was 25.6% in the HAPE-s and 9.8% in the controls, which was significantly different between the two groups (P =0.0044). The eNOS4a allelic frequency of 27-bp variable numbers of tandem repeats was 23.2% in the HAPE-s, significantly higher than that of 6.9% in the controls (P =0.0016). In HAPE-s group, 11 of 41 (26.8%) subjects possessed simultaneously both of the two significant alleles, but among the controls, none did, which showed a high statistical difference between the two groups (P =0.000059). Conclusions—Both polymorphisms of the eNOS gene were significantly associated with HAPE. A genetic background may underlie the impaired NO synthesis in the pulmonary circulation of HAPE-s. These polymorphisms could be genetic markers for predicting the susceptibility to HAPE.

Inflammatory cytokines in BAL fluid and pulmonary hemodynamics in high-altitude pulmonary edema.

To evaluate the pathogenesis of high-altitude pulmonary edema (HAPE), we performed bronchoalveolar lavage (BAL) and pulmonary hemodynamic studies in seven patients with HAPE at its early stage. We measured cell counts, biochemical contents, and concentrations of pro-inflammatory cytokines including interleukin (IL)-1, IL-6, IL-8 and tumor necrosis factor (TNF)-alpha and of anti-inflammatory cytokines including IL-1 receptor antagonist (ra) and IL-10 in the BAL fluid (BALF). All patients showed increased counts for total cells, alveolar macrophages, neutrophils and lymphocytes, and markedly elevated concentrations of proteins, lactate dehydrogenase, IL-1beta, IL-6, IL-8, TNF-alpha and IL-1ra. The levels of IL-1alpha and IL-10 were not increased. Patients also showed pulmonary hypertension with normal wedge pressure. Both the driving pressure obtained as pulmonary arterial pressure minus wedge pressure and the PaO2 under room air were significantly correlated with the concentrations of IL-6 and TNF-alpha in the BALF. These findings suggest that the inflammatory cytokines play a role at the early stage of HAPE and might be related to pulmonary hypertension.

Spontaneous Pneumomediastinum in 33 Patients: Yield of Chest Computed Tomography for the Diagnosis of the Mild Type

Background: Spontaneous pneumomediastinum (SPM) usually occurs in young people without an apparent precipitating factor or disease. Although there have been many studies focused on the clinical features and standard chest X-ray (CXR) findings of SPM, few have reviewed the chest computed-tomographic (CT) findings. Objectives: We assessed SPM using CXR and CT, and the relation between them. Methods: We evaluated 33 patients (26 males) diagnosed with SPM on the basis of symptoms and chest radiological findings. Results: Three patients showed normal CXR but a diagnostic CT scan. Seven showed mild pneumomediastinum on CXR. In these 10 patients, pneumomediastinum was easily detected by chest CT. Moderate and severe SPM were easily detected by both CXR and CT. Conclusions: These findings suggested that CXR alone poorly detected approximately 30% of SPM and that chest CT scan was needed to make the diagnosis in these cases. It seems likely that SPM is underdiagnosed by 30% or more in clinical practice.

Changes in pulmonary vascular tone during exercise. Effects of nitric oxide (NO) synthase inhibition, L-arginine infusion, and NO inhalation.

Nitric oxide (NO) is a potent endogenous vasodilator. Its role in the normal and stressed pulmonary circulation is unclear. To better understand the importance of endogenous NO in normal physiological responses, we studied the effects of altered NO availability on the change in pulmonary vascular tone that accompanies exercise. In paired studies we measured blood flow and pressures in the pulmonary circulation at rest and during treadmill exercise at a speed of 4 mph with and without (a) N omega-nitro-L-arginine, 20 mg/kg intravenously, a selective inhibitor of NO synthase; (b) L-arginine, 200 mg/kg intravenously, substrate for NO synthase; (c) combination of the inhibitor and substrate; and (d) inhalation of NO > 30 ppm, to determine if endogenous release of NO elicits maximal vasodilation. In addition, we sought to determine the site of NO effect in the pulmonary circulation by preconstriction with either U-44619 or hypoxia (fraction of inspired O2 = 0.12) using a distal wedged pulmonary catheter technique. NO synthase inhibition raised pulmonary vascular tone equally at rest and exercise. L-Arginine reversed the effects of NO synthase inhibition but had no independent effect. NO inhalation did not reduce pulmonary vascular tone at rest or enhance the usual reduction in pulmonary vascular resistance with exercise. The effect of NO synthase inhibition was in pulmonary vessels upstream from small veins, suggesting that endogenous NO dilates primarily small arteries and veins at rest. We conclude that, in sheep, endogenous NO has a basal vasodilator function that persists during, but is not enhanced by, exercise.

Pulmonary involvement of autoimmune pancreatitis

Background  A wide variety of systemic lesions have been seen in patients with autoimmune pancreatitis. The pulmonary involvement of autoimmune pancreatitis was analysed to clarify the clinicopathological features of pulmonary lesions in comparison with pulmonary sarcoidosis.

Genetic Heterogeneity of EGFR Mutation in Pleomorphic Carcinoma of the Lung: Response to Gefitinib and Clinical Outcome

Somatic epidermal growth factor receptor (EGFR) mutations in exons 19 and 21 have been found in non-small cell lung cancer (NSCLC) and are associated with the therapeutic response to gefitinib in patients with advanced NSCLC. We report a case of pleomorphic carcinoma of the lung with different EGFR mutations. Prior to gefitinib treatment, an exon 19 deletion of EGFR mutation was positive in the specimens obtained from pleural effusion and left cervical lymph node, histologically proven to be adenocarcinoma. However, the response to gefitinib was poor and the patient died of progressive disease 4 months after the initiation of gefitinib therapy. Postmortem examination revealed the major histological component to be of the sarcomatoid or pleomorphic type with scant mixed adenocarcinoma, resulting in a histological diagnosis of pleomorphic carcinoma of the lung. Although the adenocarcinomatous tissue was still positive for exon 19 deletion of EGFR mutation alone, sarcomatous components had both the exons 19 deletion and 20 T790M mutation concomitantly, thought to be a gefitinib resistance mutation. Pulmonary pleomorphic carcinoma is a rare NSCLC composed of biphasic and heterogeneous malignant cell populations. The present case suggested that expression of different EGFR mutations is related to the biphasic histological appearance in pulmonary pleomorphic carcinoma.

Usefulness of Preoperative Endobronchial Ultrasound for Airway Invasion around the Trachea: Esophageal Cancer and Thyroid Cancer

Background: It is important to confirm preoperative tracheobronchial invasion to enable the selection of the most appropriate treatment. Objective: This study was performed to compare the usefulness of computed tomography (CT), magnetic resonance image (MRI) and bronchoscopy by endobronchial ultrasonography (EBUS) for the assessment of invasion of thyroid or esophageal cancer in cases with suspected tracheobronchial invasion. Methods: In cases with suspected contact between the tumor and tracheobronchial wall, CT, MRI and EBUS indicated deformity of the tracheobronchial wall due to the adjacent mass. The final diagnosis was based on surgical and histological results, and/or clinical follow-up. Results: Fifty-four patients were included in this study. Based on the findings of CT, MRI and EBUS, invasion was suspected in 29, 28 and 25 patients, respectively. Seventeen patients did not undergo surgery based on the results of CT, MRI and bronchoscopy with EBUS. Final diagnosis was intact trachea or bronchial adventitia in 26 patients and invasion in 28 patients. The sensitivity and specificity of CT, MRI and EBUS for invasion were 59 and 56, 75 and 73, and 92 and 83%, respectively. The accuracy of EBUS was significantly greater than that of CT in the present study (p = 0.0011). The accuracy of EBUS was significantly different from that of CT and MRI in the surgically treated patients (p = 0.005 and p = 0.032, respectively). Conclusion: EBUS is the most useful technique for determining the depth and extent of tumor invasion into the airway wall. The combination of MRI and EBUS will contribute to surgical planning in patients with esophageal and thyroid cancer.

Gefitinib as first-line treatment in elderly epidermal growth factor receptor-mutated patients with advanced lung adenocarcinoma: results of a Nagano Lung Cancer Research Group study.

UNLABELLED Efficacy of first-line gefitinib for elderly epidermal growth factor receptor mutated patients with lung adenocarcinoma is uncertain. This study was aimed to investigate efficacy of gefitinib for such population. The primary endpoint was response rate (RR) and at least 12 cases were needed. Overall RR was 59% (95% confidence interval, 33%-81%) and first-line gefitinib was effective for elderly patients. INTRODUCTION Feasibility of gefitinib therapy in elderly patients with non-small-cell lung cancer is uncertain. This phase II study aimed to investigate the efficacy and usefulness of gefitinib therapy as a first-line treatment for elderly patients who have advanced lung adenocarcinoma with epidermal growth factor receptor (EGFR) mutations. PATIENTS AND METHODS We enrolled chemotherapy-naïve advanced lung adenocarcinoma patients aged 75 years or older. Patients were administered gefitinib (250 mg) once daily until progression or unacceptable toxicity. The primary endpoint was response rate (RR), and secondary endpoints were disease control rate (DCR; defined as complete response [CR] plus partial response [PR] plus stable disease [SD]), progression-free survival (PFS), overall survival (OS), and toxicity profile. RESULTS Between April 2008 and November 2009, 17 lung adenocarcinoma patients were enrolled. Overall RR was 59% (95% confidence interval [CI]: 33% to 81%), with 2 patients achieving CR and 8 PR. SD was noted in 5 patients, and DCR was 88% (95% CI: 62% to 98%). Median PFS was 12.9 months (95% CI: 2.2 to 23.6 months), and median OS had not yet been reached. Major grade 3 toxicities were skin rash (12%) and increased levels of aspartate aminotransferase or alanine aminotransferase (18%). CONCLUSION First-line treatment with gefitinib was effective and well-tolerated in elderly patients with EGFR mutations.

Exercise-induced pulmonary vasoconstriction during combined blockade of nitric oxide synthase and beta adrenergic receptors.

We studied the effects of inhibition of nitric oxide (NO) (endothelium-derived relaxation factor) synthase in combination with alpha and beta adrenergic receptor blockade on pulmonary vascular tone during exercise. In paired studies, we exercised sheep on a treadmill at a speed of 4 mph, and measured blood flow and pressures across the pulmonary circulation with and without inhibition of NO synthase (N omega-nitro-L-arginine 20 mg/kg intravenous [i.v.]), alpha receptor blockade (phentolamine 5 mg i.v.), beta receptor blockade (propranolol 1 mg i.v.), and combined alpha and beta receptor blockade. Activation of both types of adrenergic receptors occurs with exercise, and because increased release in NO is hypothesized to occur during exercise, these studies were designed to determine the magnitude of effect and interactions of these competing dilator and constrictor influences. We found that inhibition of NO synthase raised pulmonary vascular resistance (PVR) at rest and that, although a reduction in PVR occurred with exercise from this new baseline, vasoconstriction persisted. Combined beta blockade and NO synthase inhibition unmasked unopposed alpha vasoconstriction; PVR rose at rest and continued to rise with exercise; and mean pulmonary arterial pressures approached very high levels, 43.8 +/- 4.4 cmH2O. Using a distal wedged pulmonary artery catheter technique, most of the vasoconstriction was found to be in vessels upstream from small pulmonary veins. During exercise in sheep there appears to be a high degree of alpha and beta adrenergic-mediated tone in the pulmonary circulation. Endogenous production of NO actively dilates pulmonary vessels at rest and opposes potent alpha-mediated pulmonary vasoconstriction during exercise.

Mitogenic activity of endothelin on human cultured prostatic smooth muscle cells.

The effects of endothelins on human prostatic smooth-muscle cell growth were examined. Endothelin-1 and endothelin-3 induced a concentration-dependent increase in DNA synthesis and also promoted cell growth. Use of subtype selective antagonists BQ-123 ((cyclo(D-Trp-D-Asp(ONa)-Pro-D-Val-Leu); endothelin ET(A) receptor selective) and BQ-788 ((N-cis-2,6-dimethylpiperidinocarbonyl-L-gamma-methyl Leu-D-Trp-(COOMe)-D-Nle-ONa); endothelin ET(B) receptor selective), indicated that mitogenic effects of endothelin were mediated through activation of both endothelin ET(A) and ET(B) receptors. The mitogenic effects of endothelin-1 and endothelin-3 were significantly inhibited by pretreatment of the cells with pertussis toxin. However, mitogenesis due to basic fibroblast growth factor was not affected. In conclusion, endothelin has mitogenic effects on human prostatic smooth muscle cells through activation of both endothelin ET(A) and ET(B) receptors via different signalling pathways from basic fibroblast growth factor. This may contribute to smooth muscle hyperplasia associated with benign prostatic hyperplasia.