Yoshihiro Nambu

FDG PET in the evaluation of the aggressiveness of pulmonary adenocarcinoma : correlation with histopathological features

2-[Fluorine-18]fluoro-2-deoxy-d-glucose (FDG) uptake within the primary lesion correlates with survival on positron emission tomography (PET) studies of patients with non-small cell lung cancer. The more metabolically active the tumour, the worse the outcome. The aim of this study was to determine whether a correlation exists between aggressiveness as determined by pathology and the findings of FDG PET in pulmonary adenocarcinoma. Thirty-five patients with 38 adenocarcinomas of the lung were studied. All patients underwent thoracotomy within 4 weeks of the FDG PET study. For semiquantitative analysis, standardized uptake values (SUVs) were calculated. Patients were classified into high SUV (⩾4.0) and low SUV (<4.0) groups. The degree of FDG uptake (SUVs) in primary lung lesions was correlated with the histopathological features of aggressiveness (pleural involvement, vascular invasion or lymphatic permeation). The mean SUV of aggressive adenocarcinomas (4.36±1.94, n = 22) was higher than that of non-aggressive ones (1.53±0.88, n = 16) (P<0.0001). Tumours with a high FDG uptake have a significantly higher likelihood of aggressiveness than those with a low FDG uptake (P = 0.0004). Analysis by the Kaplan-Meier methods revealed that the groups had different prognoses (log-rank test, P = 0.0099). The high SUV group had a significantly worse prognosis. In conclusion, a correlation was seen between aggressiveness as determined by pathology and glucose metabolism as measured by FDG PET in adenocarcinoma of the lung. FDG PET may be used as a non-invasive diagnostic technique in measuring aggressiveness and prognosis in patients with pulmonary adenocarcinoma.

Lung deflation impairs alveolar epithelial fluid transport in ischemic rabbit and rat lungs

BACKGROUND Because the fluid transport capacity of the alveolar epithelium after lung ischemia with and without lung deflation has not been well studied, we carried out experimental studies to determine the effect of lung deflation on alveolar fluid clearance. METHODS After 1 or 2 hr of ischemia, we measured alveolar fluid clearance using 125I-albumin and Evans blue-labeled albumin concentrations in in vivo rabbit lungs in the presence of pulmonary blood flow and in ex vivo rat lungs in the absence of any pulmonary perfusion, respectively. RESULTS The principal results were: (1) lung deflation decreased alveolar fluid clearance while inflation of the lungs during ischemia preserved alveolar fluid clearance in both in vivo and ex vivo studies; (2) alveolar fluid clearance was normal in the rat lungs inflated with nitrogen (thus, alveolar gas composition did not affect alveolar fluid clearance); (3) amiloride-dependent alveolar fluid clearance was preserved when the lungs were inflated during ischemia; (4) terbutaline-simulated alveolar fluid clearance was preserved in the hypoxic rat lungs inflated with nitrogen; (5) lecithinized superoxide dismutase, a scavenger of superoxide anion, and N(omega)-nitro-L-arginine methyl ester, an inhibitor of nitric oxide, preserved normal alveolar fluid clearance in the deflated rat lungs. CONCLUSION Lung deflation decreases alveolar fluid clearance by superoxide anion- and nitric oxide-dependent mechanisms.

Expression and Localization of a Novel Rab Small G Protein (Rab38) in the Rat Lung

The Rab small G protein family participates in intracellular vesicle transport, including exocytosis and endocytosis. The cDNA encoding a novel Rab-related small G protein (Rab38) has been cloned from rat lung cDNA library and recorded in GenBank (accession no. M94043). However, the expression and localization of the protein in the lung remains primarily unknown. We produced polyhistidine-tagged recombinant Rab38 and a polyclonal antibody with a synthetic peptide. Immunohistochemistry demonstrated that the protein is specifically localized in alveolar type II cells and in bronchial epithelial cells. In situ hybridization using a digoxygenin-labeled RNA riboprobe clearly showed that the mRNA of the protein is localized in alveolar type II cells and bronchial epithelial cells, especially terminal airway epithelial cells. Western blot and reverse transcriptase-polymerase chain reaction showed distinct expression of the protein and mRNA in isolated alveolar type II cells, but not in alveolar macrophages. The native protein was predominantly hydrophobic and was enriched in a high-density vesicle fraction but was barely detectable in nuclear and lamellar body fractions in alveolar type II cells. Immunofluorescence cytochemistry performed on cultured alveolar type II cells showed that Rab38 distributed extensively in the cytoplasm with a distribution pattern similar to endoplasmic reticulum rather than other subcellular organelles. These results suggest that this novel rab small G protein (Rab38) mediates vesicular transport in terminal airway epithelium.

Unique expression patterns and alterations in the intestinal protein villin in primary and metastatic pulmonary adenocarcinomas

The identification of markers that distinguish primary pulmonary adenocarcinomas from pulmonary adenocarcinomas secondary to the digestive tract would be clinically important. Villin, a specific marker in digestive‐tract malignancies, was evaluated in 57 pulmonary adenocarcinomas, six samples of proximal bronchial tissue, and five metastatic pulmonary adenocarcinomas (three colon and two esophageal adenocarcinomas) by using immunohistochemical and molecular analyses. Villin was expressed in 31.6% (18 of 57) of the pulmonary adenocarcinomas and showed either a diffuse cytoplasmic pattern (10.5%) or a primary cytoplasmic pattern with minor brush‐border staining (21.1%). However, none of those samples demonstrated the primary brush‐border staining pattern that was characteristic of all five of the metastatic digestive‐tract adenocarcinomas. There was a significant difference in the positive brush‐border staining pattern between the primary and metastatic pulmonary adenocarcinomas (P < 0.002). Villin protein was expressed in bronchial epithelial cells, and villin mRNA was detected by reverse transcription–polymerase chain reaction. Northern analysis demonstrated 3.5‐ and 2.7‐kb villin mRNAs in villin protein–positive tumors, but villin mRNA was not detected in non‐tumorous lung tissue, indicating the transcriptional upregulation of villin in lung tumors. An additional smaller‐sized mRNA (1.8 kb) was observed in six of 10 pulmonary adenocarcinomas and in the bronchoalveolar carcinoma cell line A549. Two small villin mRNAs were cloned from the cell line A549 and were found to represent an alternatively spliced (exon 8–exon 14) 1.85‐kb mRNA and a 1.8‐kb mRNA that was missing a portion of the 5′ region (exon 1–exon 9) of the native villin mRNA. These studies demonstrated that the pattern of villin expression and the presence of altered villin mRNAs may be useful markers for pulmonary adenocarcinomas as well as provide support for the potential origin of villin‐expressing tumors from bronchial epithelial cells. Mol. Carcinog. 23:234–242, 1998.

BETA1-ADRENOCEPTOR STIMULATION BY HIGH-DOSE TERBUTALINE DOWNREGULATES TERBUTALINE-STIMULATED ALVEOLAR FLUID CLEARANCE IN EX VIVO RAT LUNG

Because high-dose terbutaline and isoproterenol (10-3