Biomedical subjects

Koichi Yamazaki

Publications and source records attributed to Koichi Yamazaki.

At least 37 records · Page 2Linked to original sources

PubMed2004

CT-guided transbronchial biopsy using an ultrathin bronchoscope with virtual bronchoscopic navigation.

STUDY OBJECTIVES: We evaluated the feasibility, safety, and efficacy of CT-guided transbronchial biopsy (TBB) using an ultrathin bronchoscope with navigation by virtual bronchoscopy (VB) for small peripheral pulmonary lesions of < 20 mm in diameter. DESIGN: A pilot study. SETTING: A national university hospital. PATIENTS: We performed CT-guided TBB after VB navigation for 25 patients with 26 small peripheral pulmonary lesions (average diameter, 13.2 mm) between June 1, 2001, and October 31, 2002. Of the 26 lesions, 10 were in the right upper lobe, 2 were in the right middle lobe, 6 were in the right lower lobe, and 8 were in the left upper lobe. Nineteen lesions were not detected on chest radiographs. INTERVENTIONS: VB images were reconstructed from helical CT scans. CT-guided TBB was performed using an ultrathin bronchoscope after studying the VB image. RESULTS: CT-guided TBB was performed safely without any complications for all patients. The bronchi seen under VB imaging were highly consistent with the actual bronchi confirmed using an ultrathin bronchoscope. The ultrathin bronchoscope was inserted between the fifth and eighth generation bronchi. The average durations of the initial scan, the first biopsy, and the total examination were 5.46, 12.96, and 29.27 min, respectively. Seventeen lesions (65.4%) were diagnosed from pathology examinations (primary lung cancers, 13; atypical adenomatous hyperplasia, 1; metastatic cancer, 1; sarcoidosis, 1; and nontuberculous mycobacteriosis, 1). Diagnoses were not obtained for the remaining lesions due to an insufficient number of specimens (six specimens) or to the inability to reach the lesions even using the ultrathin bronchoscope (three specimens). CONCLUSIONS: In summary, CT-guided TBB using an ultrathin bronchoscope with VB navigation was safely performed and was effective for diagnosing small peripheral pulmonary lesions.

Aged↗

PubMed2004

Soluble receptor-binding cancer antigen expressed on SiSo cells in pleural fluid: a potential diagnostic marker for malignant pleural effusion.

BACKGROUND: We sought a marker to differentiate malignant from nonmalignant pleural effusions. METHODS: We studied 41 patients presenting with pleural effusions to the National Sanyo Hospital between April 2000 and January 2002 (33 men and 8 women; mean age, 68 years). Twenty patients (49%) were proven to have malignant pleural effusions, while 21 patients (51%) had nonmalignant pleural effusions. Thoracentesis was performed. RESULTS: The mean (+/- SD) concentration of receptor-binding cancer antigen expressed on SiSo cells (RCAS1) in malignant pleural effusions, measured by enzyme-linked immunosorbent assay, was significantly higher than that in nonmalignant pleural effusions (15.1 +/- 33.6 vs 1.4 +/- 0.81 U/mL, respectively; p < 0.05). CONCLUSION: The determination of the RCAS1 concentration in pleural fluid is informative in the diagnosis of malignant pleural effusions.

Adult↗

PubMed2004

Paraneoplastic cerebellar degeneration (PCD) associated with squamous cell carcinoma of the lung.

We report a case of a 71-year-old man who presented with cerebellar dysfunction. He was diagnosed as having squamous cell carcinoma of the lung (T2N3M0, Stage IIIB). No anti-onconeural antibodies were found in his serum. Cerebral spinal fluid (CSF) examination showed mild mononuclear pleocytosis alone. Magnetic resonance imaging (MRI) of the brain and spinal cord revealed no abnormalities. At autopsy, there was complete disappearance of Purkinje cells with reactive astrocytosis. These findings are compatible with paraneoplastic cerebellar degeneration (PCD). To our knowledge, no case of PCD has been reported previously in patients with squamous cell carcinoma of the lung.

Aged↗

PubMed2004

Enhanced virtual bronchoscopy using the pulmonary artery: improvement in route mapping for ultraselective transbronchial lung biopsy.

OBJECTIVE: We evaluated a new simulation method for ultraselective transbronchial lung biopsy using the pulmonary artery. MATERIALS AND METHODS: A new method for enhanced virtual bronchoscopy using the pulmonary artery was developed for ultraselective transbronchial lung biopsy. In a volunteer study of healthy adults, three radiologists with different levels of experience independently reconstructed conventional virtual bronchoscopy and enhanced virtual bronchoscopy using the pulmonary artery until reaching the farthest point of the bronchus and pulmonary artery. The bronchovascular branch order and the minimum luminal diameter (e.g., for bronchus and artery) for reconstruction were compared. In a clinical study, virtual bronchoscopy and enhanced virtual bronchoscopy using the pulmonary artery were compared with regard to accessibility to target lesions in 40 patients with small pulmonary nodules or ground-glass opacities. A comparison between the simulated bronchial route reconstructions and actual bronchoscopic routes on biopsy was made to determine the efficacy of each reconstruction method. RESULTS: In the volunteer study, quality of enhanced virtual bronchoscopy using the pulmonary artery was not significantly affected by the experience levels of the radiologists. In the clinical study, bronchial reconstruction was successful in guiding to a bronchoscopic tumor in 35 (87.5%) of 40 cases. The maximum bronchial order on reconstruction was the sixth for the virtual bronchoscopy group and the eighth for the group with enhanced virtual bronchoscopy using the pulmonary artery (p < 0.001, Wilcoxon's signed rank test). The bronchial route reconstructed on enhanced virtual bronchoscopy using the pulmonary artery agreed with the actual biopsy routes in 30 cases (85.7%), but those reconstructed on virtual bronchoscopy alone agreed in only eight cases (22.9%) (p < 0.001, chi-square test). CONCLUSION: Enhanced virtual bronchoscopy using the pulmonary artery is feasible and helpful for ultraselective transbronchial lung biopsy of small nodules in the lung.

Aged↗

PubMed2004

[A case of paclitaxel-induced pneumonitis].

A 79-year-old woman with small-cell lung cancer was treated weekly with paclitaxel after previous treatment with carboplatin and etoposide. Within the first course of paclitaxel, chest radiography and CT revealed thickening of the bronchovascular bundle and interlobular septa, and infiltrates in both lung fields. A marked increase in the number of lymphocytes was found on bronchoalveolar lavage (BAL). Microorganisms such as Cytomegalovirus, Mycobacteria, and Pneumocystis carinii were absent from the BAL fluid. Interstitial infiltration was partially improved simply by stopping paclitaxel administration, without the need for any additional therapy. Drug-induced pneumonitis caused by paclitaxel was diagnosed on the basis of the clinical course and findings, although a drug lymphocyte stimulation test yielded negative results for paclitaxel. Interstitial infiltrates on imaging, symptoms and arterial blood gas results improved with administration of oral prednisolone. The possibility of pneumonitis induced by paclitaxel should be considered even in cases without interstitial lung disease.

Aged↗

PubMed2004

Lung adenocarcinoma presenting with enlarged and multiloculated cystic lesions over 2 years.

We report a case of lung adenocarcinoma in which cystic lesions enlarged and multiloculated over 2 years. Histological examination of the resected specimen found proliferation of nonmucinous adenocarcinoma cells along the alveolar walls, revealing bronchioloalveolar cell carcinoma type extension. In cystic lesions, particularly those not associated with inflammation, lung adenocarcinoma, particularly bronchioloalveolar cell carcinoma type, should be a diagnostic consideration. .

Adenocarcinoma, Bronchiolo-Alveolar↗

PubMed2003

Bronchoscopic microsampling method for measuring drug concentration in epithelial lining fluid.

Direct measurement of the concentration of antimicrobial agents in bronchial epithelial lining fluid (ELF) would allow for a more informed approach to appropriate dosing of antimicrobial agents for respiratory tract infections. In this study, we determined the time versus concentration profile in ELF after an oral administration of levofloxacin, using recently developed bronchoscopic microsampling probes. These probes could be repeatedly and safely inserted through the fiberoptic bronchoscope in normal healthy volunteers. The concentration of levofloxacin in ELF was 43.4% of the corresponding serum value at 1 hour, reached the same level at 2 hours, decreased in a similar manner as that in serum, and returned to undetectable levels at 24 hours. It exceeded minimal inhibitory concentrations of Staphylococcus aureus (0.25 microg/ml), Klebsiella species (0.5 microg/ml), and Haemophilus influenzae (0.06 microg/ml) after 6 hours. The experimental procedure was well tolerated, and no complications were observed. In conclusion, bronchoscopic microsampling is a feasible and promising method for measuring antimicrobial concentrations in the target sites of respiratory tracts directly and repeatedly.

Adult↗

PubMed2003

Granulocyte-macrophage colony-stimulating factor gene-transduced tumor cells combined with tumor-derived gp96 inhibit tumor growth in mice.

Granulocyte-macrophage colony-stimulating factor (GM-CSF)-based cancer cell vaccines have been shown to be potent inducers of antitumor immunity in several murine models, but the antitumor effects on established tumors have been minimal. Conversely, the major role of the heat shock protein gp96, localized in the endoplasmic reticulum (ER), is to act as a molecular chaperone to assist the folding of nascent polypeptide chains in the ER. gp96 derived from tumor cells elicits specific protective immunity against parental tumors, presumably through the transport of tumor-specific peptides to antigen-presenting cells and the maturation of dendritic cells (DCs). However, the therapeutic effects of tumor-derived gp96 on established tumors have not been promising. The present study analyzes the therapeutic effects of GM-CSF gene-transduced Lewis lung cancer (LLC/GM) cells combined with LLC-derived gp96 on established wild-type LLC tumors in immunocompetent C57BL/6 mice. Therapy with either irradiated LLC/GM cells or LLC-derived gp96 barely affected established LLC tumor growth. The antitumor effect was significantly enhanced when 1 microg of LLC-derived gp96 was administered together with 1 x 10(6) irradiated LLC/GM cells (p < 0.05). The antitumor effects of irradiated LLC/GM cells and LLC-derived gp96 required mainly CD8(+) T cells. Spleen cells obtained from mice vaccinated with irradiated LLC/GM cells and LLC-derived gp96 showed specific CD8 cytotoxic activities against LLC cells (specific lysis rate of approximately 28%). This antibody response was not associated with a synergic effect of the combination therapy. Moreover, draining lymph nodes from mice immunized with irradiated LLC/GM cells and LLC-derived gp96 contained more migrating mature CD11c(+) cells (higher levels of CD86 and major histocompatibility complex [MHC] class II molecules) compared with those from any other immunization protocols. These results suggest that the combination of irradiated LLC/GM cells and tumor-derived gp96 has potential as a new immunogene therapeutic strategy against lung cancer.

Animals↗

PubMed2003

Feasibility of insertion/implantation of 2.0-mm-diameter gold internal fiducial markers for precise setup and real-time tumor tracking in radiotherapy.

PURPOSE: To examine the feasibility and reliability of insertion of internal fiducial markers into various organs for precise setup and real-time tumor tracking in radiotherapy (RT). MATERIALS AND METHODS: Equipment and techniques for the insertion of 2.0-mm-diameter gold markers into or near the tumor were developed for spinal/paraspinal lesions, prostate tumors, and liver and lung tumors. Three markers were used to adjust the center of the mass of the target volume to the planned position in spinal/paraspinal lesions and prostate tumors (the three-marker method). The feasibility of the marker insertion and the stability of the position of markers were tested using stopping rules in the clinical protocol (i.e., the procedure was abandoned if 2 of 3 or 3 of 6 patients experienced marker dropping or migration). After the evaluation of the feasibility, the stability of the marker positions was monitored in those patients who entered the dose-escalation study. RESULTS: Each of the following was shown to be feasible: bronchoscopic insertion for the peripheral lung; image-guided transcutaneous insertion for the liver; cystoscopic and image-guided percutaneous insertion for the prostate; and surgical implantation for spinal/paraspinal lesions. Transcutaneous insertion of markers for spinal/paraspinal lesions and bronchoscopic insertion for central lung lesions were abandoned. Overall, marker implantation was successful and was used for real-time tumor tracking in RT in 90 (90%) of 100 lesions. No serious complications related to the marker insertion were noted for any of the 100 lesions. Using three markers surgically implanted into the vertebral bone, the mean +/- standard deviation in distance among the three markers was within 0.2 +/- 0.6 mm (range -1.4 to 0.8) through the treatment period of 30 days. The distance between the three markers gradually decreased during RT in five of six prostate cancers, consistent with a mean rate of volume regression of 9.3% (range 0.015-13%) in 10 days. CONCLUSIONS: Internal 2.0-mm-diameter gold markers can be safely inserted into various organs for real-time tumor tracking in RT using the prescribed equipment and techniques. The three-marker method has been shown to be a useful technique for precise setup for spinal/paraspinal lesions and prostate tumors.

Adenocarcinoma↗

PubMed2003

CD4+ T cells in cancer stroma, not CD8+ T cells in cancer cell nests, are associated with favorable prognosis in human non-small cell lung cancers.

We investigated intratumoral tumor-infiltrating lymphocytes (TILs), including CD4(+) and CD8(+) T cells, in non-small cell lung cancers (NSCLCs) and their relationships with clinicopathological variables and post-operative survival. Tumor specimens from 178 NSCLCs were consecutively obtained by surgery at the Hokkaido University Medical Hospital between 1976 and 1994. CD8(+) T cells, CD4(+) T cells and Ki-67/CD8(+) T cells were visualized immunohistochemically, and counted within cancer cell nests and in cancer stroma. CD8(+) T cells and CD4(+) T cells were observed at higher frequencies within cancer cell nests in moderately and poorly differentiated tumors compared with well differentiated tumors (P < 0.01), and in tumors with high Ki-67 expression compared with low Ki-67 expression (P < 0.01), that showed severe cellular atypia and a higher growth rate. Patients with higher numbers of CD8(+) T cells within cancer cell nests showed significantly shorter survival times compared to those with lower numbers of CD8(+) T cells within cancer cell nests (5-year survival rates, 47% and 60%, respectively; P = 0.03). Moreover, patients with higher labeling index of Ki-67/CD8(+) T cells showed significantly shorter survival than those with lower labeling index of Ki-67/CD8(+) T cells within cancer cell nests (5-year survival rates, 41% and 69%, respectively; P = 0.02), and the labeling index of Ki-67/CD8(+) T cells within cancer cell nests was found to be a significant and independent unfavorable prognostic factor by multivariate analysis (P = 0.01). On the other hand, higher numbers of CD4(+) T cells in cancer stroma, but not within cancer cell nests, were correlated with longer survival times in patients with NSCLC (5-year survival rates, 64% and 43%, respectively; P = 0.04). CD4(+) T cells in cancer stroma might reflect immune responses against cancer cells, while CD8(+) T cells do not appear to work as effectors in tumor tissues of NSCLC. Moreover, the higher labeling index of Ki-67/CD8(+) T cells within cancer cell nests is a strong indicator of unfavorable clinical outcome.

Adenocarcinoma↗

PubMed2003

Predictive value of expression of P53, Bcl-2 and lung resistance-related protein for response to chemotherapy in non-small cell lung cancers.

Chemoresistance is a major problem in the chemotherapy of non-small cell lung cancers (NSCLCs). Several mechanisms are thought to be involved in drug resistance, including those associated with apoptosis, drug transport and detoxification. Here, we investigated the predictive value of P53, Bcl-2 and lung resistance-related protein (LRP) expression for response to platinum-based chemotherapy, using transbronchial biopsy (TBB) specimens from patients with NSCLC. We evaluated TBB specimens from 57 patients with NSCLC who had not previously been treated with either chemotherapy or radiotherapy before TBB, and who were treated with systemic platinum-based chemotherapy. The specimens included 33 adenocarcinomas, 22 squamous cell carcinomas and two large cell carcinomas. One to 6 courses of chemotherapy were administered. Expression of P53, Bcl-2 and LRP was analyzed by immunohistochemistry using TBB specimens. Positive expression of P53, Bcl-2 and LRP was observed in 28 (49%), 41 (71%) and 42 (73%) of the 57 NSCLCs, respectively. P53 expression correlated significantly with response to chemotherapy in nonsquamous cell carcinomas, including adenocarcinomas and large cell carcinomas (response rates, 38% and 6% for patients with P53-positive and P53-negative tumors, respectively, P = 0.03). LRP expression significantly correlated inversely with response to chemotherapy in squamous cell carcinomas (response rates, 33% and 100% for patients with LRP-positive and LRP-negative tumors, respectively, P = 0.02). Bcl-2 expression did not correlate with response to chemotherapy. These findings indicate that immunostaining for P53 and LRP using TBB specimens may be useful for dividing patients with NSCLC into chemoresponsive and chemoresistant groups.

Adenocarcinoma↗

PubMed2003

[A case of Mycobacterium avium pulmonary disease detected as multiple small nodular shadows and diagnosed by CT guided transbronchial biopsy with ultrathin bronchoscopy].

A 65-year-old man was admitted to our hospital because multiple small nodular shadows measuring five to 12 mm in diameter in both lung fields were noticed on chest radiographs and CT scans during a regular checkup for pulmonary emphysema. The levels of ESR and CRP were within normal limits, but those of CEA and CYFRA were slightly elevated. Mycobacterium avium (M. avium) was detected in sputum cultures and in a sputum examination using PCR. Non-necrotizing granulomas were detected in the specimens obtained from a lesion of the right S6b by CT-guided transbronchial biopsy using an ultrathin bronchoscope after navigation with virtual bronchoscopy. On the basis of these findings, M. avium pulmonary disease was diagnosed. The patient is being followed up, but because he has no symptoms, without medication. To our knowledge, there have been no previous reports of M. avium-intracellulare complex pulmonary disease, which is characterized by multiple small nodular shadows. It is speculated that multiple centrilobular lesions developed simultaneously without extension to the bronchial walls, leading in this case to multiple small nodules in both lung fields.

Aged↗

PubMed2002

Real-time tumor-tracking radiation therapy for lung carcinoma by the aid of insertion of a gold marker using bronchofiberscopy.

BACKGROUND: The authors developed fluoroscopic real-time tumor-tracking radiation therapy (RTRT) by insertion of a gold marker using bronchofiberscopy to reduce uncertainties in organ motion and set-up error in external radiotherapy for moving tumors. The purpose of the current study was to evaluate RTRT's feasibility in lung carcinoma treatment. METHODS: The three-dimensional position of a 1.0-2.0 mm gold marker in or near the tumor was detected by two sets of fluoroscopies every 0.03 seconds. The treatment beam was gated to irradiate the tumor only when the position of the marker coincided with its planned position using the RTRT system. Bronchofiberscopic equipment for insertion of the marker into the lung tumor was developed and used for 20 lung tumors in 18 patients. Patients were given high dose hypofractionated focal irradiation (35-48 Gy in 4-8 fractions in 4-10 days) with a planning target volume margin of 5 mm for the tumor. RESULTS: The markers were successfully inserted and maintained at the inserted position during and after the radiotherapy in 14 (88%) of 16 peripheral-type lung tumors and in none of four central-type lung tumors, indicating that this method of RTRT was not feasible for central-type lung tumors. Tracking of the marker was successfully performed in 1 of 2 tumors with a 1.0 mm marker and in all of 12 tumors with a 1.5-2.0 mm marker. On the whole, 13 (65%) of the 20 tumors were successfully treated with RTRT. Local tumor control was achieved and maintained for all 12 patients (13 tumors), who were treated with RTRT, with a median followup of 9 months (range, 5-15). Localized radiation pneumonitis was found radiographically at the lung volume that was irradiated with about 20 Gy, without symptoms in all but one patient. CONCLUSIONS: The insertion of a gold marker into or near peripheral-type lung tumors using bronchofiberscopy is a feasible and safe technique. Excellent initial response and low incidence of clinical complications suggest that the high dose hypofractionated focal irradiation using the RTRT system can be a good local treatment for peripheral-type lung tumors.

Adult↗

PubMed2002

Small-volume image-guided radiotherapy using hypofractionated, coplanar, and noncoplanar multiple fields for patients with inoperable Stage I nonsmall cell lung carcinomas.

BACKGROUND: Occasionally, medically compromised and/or elderly patients with nonsmall cell lung carcinomas (NSCLCs) cannot be treated surgically. We investigated small-volume hypofractionated image-guided radiotherapy (IGRT) without the need for breath control in patients with inoperable Stage I NSCLCs. METHODS: Between September 1996 and September 1999, 22 patients with Stage I NSCLCs, including 19 males and 3 females, were treated with IGRT. Among these patients, there were 13 Stage IA and 9 Stage IB tumors. The tumors ranged in size from 14.2 to 58.5 mm, with a median size of 26.7 mm. Of the 22 patients, 19 were unfit for surgical treatment due to poor pulmonary function, complications, and/or advanced age and 3 refused surgery. Computed tomographic scans (CT) of the primary tumor were taken during three respiratory phases and they were analyzed to determine the planning target volume, which included only the primary tumor with allowances for respiratory movement. The radiation doses administered at the edge of the moving tumor during normal breathing were 80% of the prescribed dose, either 48 or 60 Gy given in eight fractions over 2 weeks. Clinical evaluation, chest CT scan, and pulmonary function tests were performed before irradiation and at regular intervals for the post-IGRT follow-up. The median follow-up period was 24 months (range, 2-44 months; mean, 21.8 months) (at least 24 months for survivors). RESULTS: Of 17 tumors assessed at the initial follow-up 2-6 months after treatment (5 complete responses, 11 partial responses, and 1 progressive disease), 16 (94%) were controlled locally. One local recurrence was observed during the follow-up. The lung carcinoma-specific survival rate at 1 year was 94% and the 1-year actuarial recurrence-free survival rate was 71%. The lung carcinoma-specific survival rate at 2 years was 73% and the 2-year actuarial recurrence-free survival rate was 67%. The treatment was well tolerated and no major side effects were observed. Localized radiation pneumonitis was observed in all patients who were examined by CT scan, but the patients were asymptomatic. Parameters of pulmonary function, including vital capacity, total lung capacity, and diffusion capacity for carbon monoxide, decreased very little or not at all, indicating that IGRT rarely deteriorated pulmonary functions. CONCLUSIONS: Small-volume hypofractionated IGRT without breath control is a feasible and beneficial method for the curative treatment of patients with Stage I NSCLCs. It has the potential of a high local tumor control rate and low morbidity.

Aged↗

PubMed2002

Increased expression of beta-catenin predicts better prognosis in nonsmall cell lung carcinomas.

BACKGROUND: beta-Catenin has been shown to function as a Wnt signaling molecule to stimulate cyclin D1 expression and cell growth in several kinds of tumors. METHODS: The authors immunohistochemically examined specimens of 217 surgically resected primary nonsmall cell lung carcinomas (NSCLCs) for beta-catenin expression and classified them semiquantitatively into three categories, including those with high, moderate, and low scores of expression. RESULTS: High, moderate, and low scores of expression were found in 37 (17.1%), 145 (66.8%), and 35 (16.1%) tumors, respectively. beta-Catenin expression was not correlated with cyclin D1 expression, but was positively correlated with the Ki-67 cell growth fraction (P = 0.04). The direct sequencing analysis for the beta-catenin gene mutation of 13 specimens of 217 tumors for the current study revealed no mutations. The relation between survival and beta-catenin expression was evaluated in 148 potentially curatively resected tumors with pathologic Stages I-IIIA. A trend toward better survival was found in patients with tumors having higher scores. In multivariate analysis, high beta-catenin expression was a significant and independent favorable prognostic factor (hazards ratio, 0.31; P = 0.007) as was pathologic stage. Analyzed by cell type, in nonsquamous cell carcinomas, patients with tumors having high scores survived a significantly longer time than those with tumors having moderate or low scores (5-year survival rates, 84%, 55%, and 32%, respectively; P = 0.02), and high beta-catenin expression tended to be a favorable prognostic factor (hazards ratio, 0.32; P = 0.052). CONCLUSIONS: These results indicate that, in NSCLCs, increased expression of beta-catenin can predict favorable prognosis of patients with resected tumors, suggesting that accumulation of beta-catenin has no or little oncogenic effect via activation of the Wnt pathway, unlike in colon carcinomas or hepatomas.

Aged↗

PubMed2002

Heat shock fusion protein gp96-Ig mediates strong CD8 CTL expansion in vivo.

PROBLEM: As shown previously, gp96-Ig peptide complexes secreted by an ovalbumin transfected tumor (EG7) mediate strong, specific tumor immunity through a CD4 T cell independent CD8+ CTL response. In this study, we set out to develop a system to quantitatively determine the CD8 CTL response to gp96-Ig and to evaluate the influence of an established wild type tumor. METHODS: Secreted heat shock protein gp96-Ig was constructed by replacement of the endoplasmic reticulum retention signal with the Fc portion of IgGI, transfected into EG7 (EG7-gp96-Ig) and used to induce CD8+ CTL expansion in vivo. Adoptively transferred, ovalbumin specific T-cell receptor (TCR) transgenic CD8+ cells (OT-1) responded with clonal expansion to the immunization with EG7-gp96-Ig. OT-1 expansion was quantitated with K(b-peptide)-tetramers by flow cytometry. RESULTS: In response to primary immunization with EG7-gp96-Ig, OT-1 expand from an initial frequency of 0.5 to 25% of all CD8 cells, and to 50% of all CD8 cells after a booster immunization. Endogenous ovalbumin specific CD8 cells also expand strongly. Antigen specific effector function was measured by enzyme-linked immunosorbent spot-forming cell assay (ELISPOT) for interferon-gamma (IFN-gamma). While effector function was strongly induced by secreted gp96-Ig, not all expanded OT-1 produce IFN-gamma. EG7 does not cause OT-1 expansion, but rather induces anergy. If OT-1 are transferred into wild type EG7 tumor bearing mice to induce anergy of OT-1, immunization with EG7-gp96-Ig can partly overcome unresponsiveness. CONCLUSIONS: We conclude that secreted gp96-Ig is a powerful mediator of specific CD8+ CTL responses in vivo. Secretory gp96 mimics release of gp96 by damaged or necrotic cells that is able to activate dendritic cells without CD4 help. Gp96-Ig associated peptides have not been selected by binding to major histocompatibility complex (MHC). Specific immunization by secreted gp96-Ig therefore is expected to occur also in allogeneic settings.

Animals↗

PubMed2002

RCAS1 expression: a potential prognostic marker for adenocarcinomas of the lung.

OBJECTIVE: RCAS1 (receptor-binding cancer antigen expressed on SiSo cells) is a new tumor-associated antigen recognized by 22-1-1 monoclonal antibody. RCAS1 expressed on human cancer cells acts as a ligand for a putative receptor present on peripheral lymphocytes. RCAS1 has been shown to inhibit the in vitro growth of receptor-expressing cells and to induce apoptosis, which may contribute to the ability of tumor cells to evade host immune surveillance. In this study, we evaluated the prognostic significance of RCAS1 expression in primary lung adenocarcinomas. METHODS: Immunohistochemical analysis was performed on tissue specimens surgically obtained from 102 patients with primary lung adenocarcinomas. Then, the association of RCAS1 expression with clinicopathological variables and prognosis of patients were analyzed. RESULTS: Of 102 lung adenocarcinomas, positive RCAS1 expression was observed in 82 cases (80%). There was no correlation between RCAS1 expression and clinicopathological variables. In 70 potentially curatively resected lung adenocarcinomas, patients with RCAS1-positive tumors had a significantly shorter survival than those with RCAS1-negative tumors (p = 0.02), and RCAS1 expression was a significant and independent prognostic factor by multivariate analysis (p = 0.03). CONCLUSIONS: These results indicate that RCAS1 expression predicts prognosis in patients with lung adenocarcinomas, and this new antigen could be a novel tumor marker which reflects the clinical outcome of lung cancers.

Adenocarcinoma↗

PubMedDate not supplied

Mediastinal lymph node staging by FDG-PET in patients with non-small cell lung cancer: analysis of false-positive FDG-PET findings.

BACKGROUND: Accurate staging of mediastinal and hilar lymph nodes is a critical factor determining operability in patients with non-small cell lung cancer (NSCLC). Positron emission tomography with 2-[18F] fluoro-2-deoxy-D-glucose as a tracer (FDG-PET) has recently been reported to be more effective in detecting tumor involvement in mediastinal and hilar lymph nodes than computed tomography (CT). OBJECTIVE: In this study, we analyzed the accuracy of FDG-PET in mediastinal and hilar lymph node staging in patients with NSCLC and the factors associated with false-positive or false-negative FDG-PET findings in mediastinal and hilar lymph node staging. METHODS: Fifty-four patients with NSCLC who underwent preoperative analysis including chest CT and whole-body FDG-PET were evaluated retrospectively. Using FDG-PET, lesions were considered to be positive if a definite, localized area of higher uptake, excluding physiologic uptake, than in surrounding normal tissue was present. On CT findings, lymph nodes were considered to be positive if they were >10 mm in short-axis diameter, except subcarinal lymph nodes (#7), which were considered to be positive if they were >15 mm in short-axis diameter. All patients underwent surgical resection of primary tumors and mediastinal and hilar lymph nodes between 1999 and 2001 in our institute. Resected lymph nodes were histologically examined for the existence of tumor cells. RESULTS: A total of 306 lymph nodes were resected and used for analysis. The sensitivity, specificity, positive predictive value and negative predictive value of FDG-PET were 73, 98, 70 and 98%, while those of CT were 55, 96, 55 and 96%, respectively. When pre-operative nodal staging was compared with post-operative histopathological staging, 44 patients (81%) were correctly staged, 7 (13%) were overstaged and 3 (6%) were understaged by FDG-PET, while 39 patients (72%) were correctly staged, 8 (15%) were overstaged and 7 (13%) were understaged by CT. All 7 overstaged patients by FDG-PET had other pulmonary complications, including interstitial pneumonitis (n = 2), previous pulmonary tuberculosis (n = 3), silicosis (n = 1) and emphysema (n = 1), although they were not in the active stage. In 3 understaged patients by FDG-PET, lymph nodes were also undetectable by CT. CONCLUSION: FDG-PET is superior to CT in mediastinal and hilar lymph node staging of patients with NSCLC. However, care should be taken in lymph node staging for patients who have other pulmonary complications, including interstitial pneumonitis, previous pulmonary tuberculosis and silicosis.

Adenocarcinoma↗