Correlation of intrinsic chemoresistance of non-small-cell lung cancer cell lines with HER-2/neu gene expression but not with ras gene mutations.

BACKGROUND: At diagnosis, most small-cell lung cancers (SCLCs) are chemosensitive, whereas non-small-cell lung cancers (NSCLCs) are usually chemoresistant. Activation of ras genes and HER-2/neu genes (also known as ERBB2) is encountered in subpopulations of NSCLC but not in SCLC and has been linked to shortened survival. Therefore, activation of these genes may be associated with intrinsic chemoresistance in NSCLC. Studies have also suggested that the multidrug-resistant phenotype expressed by the MDR1 gene (also known as PGY1) does not correlate with the in vitro chemosensitivity of NSCLC cells or with clinical response to therapy and does not explain the spectrum of cross-resistance to drugs. PURPOSE: The purpose of this study was to investigate the relationships between chemoresistance and the presence of ras gene point mutations and overexpression of the HER-2/neu gene in NSCLC cell lines, which indicates gene activation. METHODS: Using a panel of 20 NSCLC cell lines established from untreated patients, we assessed the differences in HER-2/neu messenger RNA (mRNA) expression in the cell lines with or without ras mutations. We performed in vitro drug sensitivity testing by the tetrazolium-based MTT [i.e., 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H- tetrazolium bromide] assay with doxorubicin, carmustine, cisplatin, melphalan, mitomycin, and etoposide, and we determined the differences in IC50 values (i.e., the drug concentrations required to inhibit cell growth by 50%) for the cell lines. RESULTS: We found a statistically significant correlation between the IC50 values for all six drugs and the degree of HER-2/neu gene expression in all 20 cell lines (r = .67-.86; P < .005) as well as in the subpopulation of eight cell lines with ras mutations (r = .83-.98; P < .05). The IC50 values for doxorubicin, carmustine, cisplatin, and melphalan were not significantly different in the cell lines with or without ras mutations, but the values for mitomycin and etoposide in lines with ras mutations were slightly lower than in those without ras mutations (borderline significance, P = .031). Levels of HER-2/neu expression in cell lines with ras mutations were lower than those without ras mutations, but the difference was not statistically significant. CONCLUSION: Our findings indicate that overexpression of HER-2/neu is a marker for intrinsic multidrug resistance in NSCLC cell lines. IMPLICATIONS: If the clinical relevance of our findings is confirmed, HER-2/neu gene expression can be used as a predictor of therapeutic failure in NSCLCs. The relationships between HER-2/neu gene expression, cell proliferation, and chemoresistance in NSCLC require further investigation.

Cytotoxic effects of gemcitabine-containing regimens against human non-small cell lung cancer cell lines which express different levels of p185neu.

A novel pyrimidine analogue, gemcitabine, has been found to inhibit DNA replication and repair. We speculated that gemcitabine in combination with DNA-damaging agents might be more active against high- than low-p185neu expressing non-small cell lung cancer (NSCLC) cells because the high-p185neu expressors were proposed to posses a more effective DNA repair ability. We therefore compared the combination effects of gemcitabine plus cisplatin, gemcitabine plus etoposide, and cisplatin plus etoposide in a panel of 12 NSCLC cell lines. We also investigated the correlations between the level of p185neu and the cytotoxicities of each single agent and the three combinations. We found that as single agents the cytotoxicities of cisplatin and etoposide but not gemcitabine were significantly correlated with the level of p185neu. In contrast to the tight cross-resistance between cisplatin and etoposide, gemcitabine demonstrated little cross-resistance to either etoposide or cisplatin. Both gemcitabine-containing combinations demonstrated equivalent or more active cytotoxicities compared to cisplatin plus etoposide, with gemcitabine plus cisplatin showing a greater synergistic activity which was effect (dose) dependent. The effect of cisplatin plus etoposide was not p185neu related, whereas gemcitabine-containing regimens, especially gemcitabine plus cisplatin, had a greater cytotoxicity against the high- than the low-p185neu expressors. Our findings indicate that gemcitabine in combination with cisplatin is active against NSCLC cells in vitro. The gemcitabine-cisplatin interaction is more active than the etoposide-cisplatin interaction in cells with high-p185neu expression.

Combination cytotoxic effects of cis-diamminedichloroplatinum(II) and 5-fluorouracil with and without leucovorin against human non-small cell lung cancer cell lines.

Both cisplatin (CDDP) and leucovorin (LV) have been shown to enhance cytotoxicity of 5-fluorouracil (FUra) against murine and human neoplasms by increasing intracellular reduced folate concentrations. We were interested in their use in a combination to inhibit non-small cell lung cancer (NSCLC) cell growth and therefore conducted an in vitro study to investigate the cytotoxic activities of combinations of CDDP plus FUra, with and without LV (20 microM), against seven NSCLC cell lines. A tetrazolium assay with application of the classical isobole method was used to test drug combinations. We found that LV enhanced FUra but not CDDP cytotoxicity and that the degree of enhancement was negatively correlated with the effect of FUra. There was an overall additive combination effect of CDDP plus FUra, although there may be synergy at higher effect levels. There was synergy to a combination of CDDP, FUra, and LV, presumably primarily related to the synergistic effects of adding LV to FUra. In summary, LV and CDDP enhanced FUra cytotoxicity in a complementary fashion and there was clear synergy of a combination of CDDP, FUra, and LV against a panel of NSCLC cell lines. Our in vitro results provide a rationale for controlled clinical studies of this three-drug regimen in patients with NSCLC.

Correlations between intrinsic chemoresistance and HER-2/neu gene expression, p53 gene mutations, and cell proliferation characteristics in non-small cell lung cancer cell lines.

Using a panel of 20 non-small cell lung cancer (NSCLC) cell lines established from previously untreated patients, we investigated the relationships between intrinsic chemoresistance (to four agents used commonly in the therapy of NSCLC) and HER-2/neu gene expression (which encodes glycoprotein p185neu), p53 gene mutations, and cell proliferation characteristics. Our results demonstrated that high p185neu expression was correlated with chemoresistance, low S-phase fractions, and long doubling times. By contrast, cell lines expressing relatively low levels of p185neu were relatively chemosensitive and had higher S-phase fractions and shorter doubling times. Although mutation of the p53 gene was a common event in this panel of cell lines (present in 18 of 20 lines), there was no relationship between mutations at any specific codon and chemoresistance or cell proliferation characteristics. Multivariate analysis revealed that the level of p185neu was the only independent predictor for chemoresistance to doxorubicin, etoposide, and probably cisplatin. Although intrinsic chemoresistance almost certainly is a multifactorial process, overexpression of p185neu may be an important factor in the chemoresistance of NSCLC.

Enhancement of chemosensitivity by tyrphostin AG825 in high-p185(neu) expressing non-small cell lung cancer cells.

The HER-2/neu gene product, p185(neu), is a membrane-bound receptor with tyrosine kinase activity. High levels of p185(neu) is correlated with intrinsic chemoresistance of non-small cell lung cancer (NSCLC) cell lines. We investigated the effects of tyrphostin AG825, a selective tyrosine kinase inhibitor preferentially inhibiting HER-2/neu kinase, on the chemosensitivities and on the drug-induced cell cycle changes of NSCLC cell lines that expressed different levels of p185(neu). Compared to the low-p185(neu) expressing cell lines, we found that the high-p185(neu) expressing cell lines were more resistant to doxorubicin, etoposide, and cis-diamminedichloroplatinum(II) but more sensitive to AG825. AG825 was able to significantly enhance the chemosensitivities of the high-p185(neu) expressing cell lines, whereas it had little effect on the chemosensitivities of the low-p185(neu) expressing cells, with a few exceptions in which minor antagonistic effects were observed. Although high concentrations of AG825 could reduce the drug-induced G(2) arrest that was accompanied by the activation of phosphorylated p34(cdc2), we failed to find any remarkably differential effects of AG825 on drug-induced G(2), arrest and the accompanying phosphorylation status of p34(cdc2) of the high- and and the low-p185(neu) expressing cell lines. In summary, tyrphostin AG825 can enhance chemosensitivity in high- but not in low-p185(neu) expressing NSCLC cell lines. This differential effect cannot be explained by the alterations of drug-induced cell cycle changes by AG825. Our results provide a rationale to develop p185(neu)- specific tyrphostin and to test them in combination with anticancer agents in vivo and in clinical trials.

Gemcitabine versus the combination of cisplatin and etoposide in patients with inoperable non-small-cell lung cancer in a phase II randomized study.

PURPOSE: A phase II randomized study was conducted to evaluate the efficacy and toxicity of gemcitabine (GEM) versus the combination of cisplatin and etoposide (EP) in Chinese patients with inoperable (stage III or IV) non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: From March 1995 to February 1996, 53 patients were enrolled onto the study: 27 onto the GEM arm and 26 onto the EP arm. In the GEM arm, gemcitabine 1,250 mg/m2 was given as a 30-minute intravenous (i.v.) infusion on days 1, 8, and 15 of each 28-day cycle. In the EP arm, cisplatin 80 mg/m2 was given on day 1 and etoposide 80 mg/m2 was given on days 1, 2, and 3 of each 28-day cycle. RESULTS: Twenty-six patients are assessable for treatment response on the GEM arm and 24 on the EP arm. Five patients (19.2%) on the GEM arm and five patients (20.8%) on the EP arm achieved a partial response (PR). No complete responses were attained on either treatment arm. All patients enrolled onto the study were eligible for toxicity assessment. The main toxicities were myelosuppression and vomiting, which included World Health Organization (WHO) grade 3 or 4 leukopenia (3.7%), thrombocytopenia (7.4%), anemia (7.4%), and nausea/vomiting (3.7%) on the GEM arm, and WHO grade 3 or 4 leukopenia (30.8%), thrombocytopenia (7.7%), anemia (15.4%), and nausea/vomiting (34.6%) on the EP arm. The median survival time was 37 weeks on the GEM arm and 48 weeks on the EP arm. CONCLUSION: Gemcitabine is a well-tolerated chemotherapeutic agent for NSCLC. The antitumor activity was promising, with a 19.2% single-drug response rate, when compared with EP combination chemotherapy, which had a response rate of 20.8%. The safety profile is better than that of EP treatment.

Presence of serum anti-p53 antibodies is associated with pleural effusion and poor prognosis in lung cancer patients.

This study was designed prospectively to evaluate the development of anti-p53 antibodies (Abs) in lung cancer patients in relation to their clinical outcome. Sera, derived from 125 lung cancer patients, consisting of 14 small cell lung cancers (SCLC) and 111 non-SCLCs (NSCLC), were surveyed. The p53-null human NSCLC cell line, NCI-H1299, transfected with a human mutant p53 gene was prepared as the source of p53 antigen for immunoblotting analyses to detect the presence of serum anti-p53 Abs. The control group included sera from 10 healthy adults and 14 patients with benign pulmonary diseases. Clinical data including staging and survival were recorded for statistical analyses. The anti-p53 Abs were found in 8% (10 of 125) of the lung cancer patients studied (8.1% of NSCLC versus 7.1% of SCLC patients), whereas none of the control sera had detectable anti-p53 Abs. The presence of anti-p53 Abs was closely associated with malignant pleural effusions (P = 0.001). The p53 Ab-positive patients had a worse prognosis than the p53 Ab-negative patients (P < 0.02; median survival, 20 versus 41 weeks). In both univariate and multivariate analyses, the tumor extension and probably the presence of anti-p53 Abs were significant predictors for cancer death. The development of anti-p53 Abs (n = 9) was also a predictor for poor survival in patients with malignant effusions (n = 51). In conclusion, the presence of serum anti-p53 Abs is closely associated with malignant pleural effusions in lung cancer patients. It may serve as a negative prognostic factor for survival independent of malignant pleural effusions and tumor staging.

The role of fiberoptic bronchoscopy in evaluating the causes of pleural effusions.

To evaluate the diagnostic merit of fiberoptic bronchoscopy in pleural effusions, we performed fiberoptic bronchoscopy in addition to thoracocentesis and closed pleural biopsy in 140 patients who were admitted for diagnostic investigation of the causes of pleural effusions. The patients were divided into subgroups based on clinical features and roentgenographic findings of chest x-ray films. In 39 patients, the pleural effusions were due to various nonneoplastic disorders and in 95 patients it was caused by malignancy. In six patients, the causes of the pleural effusions remained undetermined. A final diagnosis was made by pleural examination in 68 patients, by fiberoptic bronchoscopy in 58 patients, and by either one or both in 100 patients. In 82 patients who had no hemoptysis, a final diagnosis was made by pleural examination in 57 cases and by fiberoptic bronchoscopy in 11 cases only. The diagnostic yield of fiberoptic bronchoscopy (47/58) was superior to that of pleural examination (11/58) in 58 patients presenting with hemoptysis. In 74 patients who had pleural effusions as the sole roentgenographic abnormality, the final entity was established by pleural examination in 45 and by fiberoptic bronchoscopy in 12. The diagnostic merit of fiberoptic bronchoscopy was significantly higher in 59 patients who had concurrent pulmonary abnormalities on their chest roentgenograms. A final diagnosis was made in 43 cases by fiberoptic bronchoscopy in comparison with 21 cases by pleural examination. For patients with unknown pleural effusions, fiberoptic bronchoscopy was more likely to yield a diagnosis than thoracocentesis with closed pleural biopsy in those who had hemoptysis or pulmonary abnormality on chest x-ray films, whereas the reverse applied when these features were absent.

The value of roentgenographic and fiberbronchoscopic findings in predicting outcome of adults with lower lung field tuberculosis.

Proper antituberculosis chemotherapy may not prevent occurrence or progression of endobronchial involvement in patients with pulmonary tuberculosis. We previously reported a higher incidence of endobronchial involvement in adults with lower lung field tuberculosis (LLFTB). We evaluated the value of roentgenographic and fiberbronchoscopic findings in predicting the outcome of adults with LLFTB after 9 months of antituberculosis chemotherapy. The most common change on chest roentgenograms among 101 patients with LLFTB was consolidation, followed by cavitary lesion, lung collapse, and solitary mass. Intrathoracic lymphadenopathy (hilar and/or mediastinal lymphadenopathy) was found in 12 cases. Sputum smear for acid-fast bacilli was positive in 64 patients, and sputum culture for tuberculous bacilli was positive in 37 of 50 patients. Endobronchial involvement was found in 45 of 63 patients who underwent fiberbronchoscopic examination. Of these 45, 18 had ulcerative granuloma, 12 had fibrostenosis, eight had submucosal infiltration, and seven had mucosal redness and swelling. A higher incidence of endobronchial involvement was found in the patients with LLFTB when they presented with roentgenographic findings of pulmonary consolidation, lung collapse, or associated intrathoracic lymphadenopathy. The outcome seemed unfavorable in the patients with LLFTB who presented with roentgenographic findings of lung collapse or pulmonary consolidation, or in those who presented with fiberbronchoscopic findings of fibrostenosis or ulcerative granuloma. Our results show that roentgenographic and fiberbronchoscopic findings are of value in predicting outcome of patients with LLFTB. With proper antituberculosis chemotherapy and close follow-up, fiberbronchoscopy may be clinically indicated in patients with LLFTB to assess the presence and severity of endobronchial involvement. Early surgical intervention can be considered in those with severe endobronchial involvement before serious sequelae occur.

Interleukin-7 and interleukin-12 have different effects in rescue of depressed cellular immunity: comparison of malignant and tuberculous pleural effusions.

The present study attempts to determine the role of interleukin-7 (IL-7) and IL-12 in recovering the functions of the lymphocytes of malignant effusion, in terms of cytokine production, proliferation, and cytolytic activity, compared with lymphocytes from tuberculous pleural effusion. Effusion-associated lymphocytes (EAL) were isolated from tuberculous (tEAL) and malignant (mEAL) pleural effusions. The EAL proliferate response was measured after 3 days in culture. Interferon-gamma (IFN-gamma) production and cytotoxicity against K-562 cells or autologous tumor cells were assessed after 6 days in culture. It was found that the mEAL had depressed proliferation, IFN-gamma production, and cytolytic activity, as compared with tEAL. Stimulation with IL-12 plus IL-2, but not with IL-7 plus IL-2, fully restored the IFN-gamma production of mEAL to that of tEAL levels. In contrast, the proliferate response of mEAL was enhanced significantly more with IL-7 plus IL-2 than with IL-12 plus IL-2. Both the IL-7 plus IL-2 and IL-12 plus IL-2 stimulation of mEAL showed a significant increase in cytolytic activity against autologous tumor cells, although the cytolytic activity against K-562 cells did not increase. These results suggest that tEAL had a higher cellular activity than mEAL. This depressed cellular function of mEAL could be reversed with cytokines. However, different cytokines had different effects on mEAL; for example, IL-7 had a better effect in the stimulation of lymphocyte proliferation compared with IL-12, which had a better effect in driving the lymphocytes to the T helper 1 (TH1) pathway and a higher IFN-gamma production. Both IL-7 and IL-12, in the presence of IL-2, can restore the immunosuppressed cytolytic activity of the lymphocytes of malignant pleural effusion against autologous tumor.

Restoration of cytotoxic T lymphocyte function in malignant pleural effusion: interleukin-15 vs. interleukin-2.

The present study attempts to define the role of interleukin-15 (IL-15), as compared with IL-2, in generating cytotoxic T lymphocytes (CTL) from the malignant effusions of cancer patients. Effusion-associated lymphocytes (EAL) from malignant effusion were incubated with IL-15 or IL-2 with or without alphaCD3. Proliferation and cytotoxicity assays were performed. IL-15 was found to have at least an equivalent, if not higher, activity to IL-2 in terms of lymphocyte proliferation and generation of CTL from EAL. The proliferative response of EAL, cocultured with IL-15, with or without alphaCD3, was partly inhibited by pretreatment with an anti-IL2 receptor beta chain monoclonal antibody (mAb). The proliferative response of EAL, cocultured with alphaCD3, IL-2, or both, was partly inhibited by pretreatment with an anti-IL-2 receptor alpha chain mAb. Overnight [5lCr] release assays against K562, Daudi, and the patients' autologous tumor cells were done to evaluate EAL's cytolytic activity. MHC class I Ab blocked the stimulated cytolytic activity of EAL against autologous tumors. An mAb depletion assay showed that the phenotype of the restored EAL was CD16-CD4-CD8+; thus, the restored activity of EAL was CTL activity. The results suggest that both IL-15 and IL-2 can restore CTL activity from EAL in the presence of T cell receptor (TCR)-CD3 engagement, but the effect of IL-15 was superior.

Significance of biochemical markers in early detection of canine lung allograft rejection.

To evaluate the significance of bronchoalveolar lavage fluid, levels of tumor necrosis factor-alpha (TNF), gamma-interferon, interleukin 2, and soluble IL-2 receptor in early detection of canine lung allograft rejection, bronchoalveolar lavages were performed serially in mongrel dogs before and after single lung transplantation. The dogs were divided into three groups. Group 1 (control group) consisted of one in which neither donor nor recipient dogs were treated with cyclosporine. In group 2 (CsA-pretreated group) only donors were treated with CsA orally at a single dose of 20 mg/kg/day for 3 days prior to single lung transplantation. In group 3 only recipients were treated with CsA orally at a single dose of 20 mg/kg/day for a short period of 9 days after single-lung transplantation. Marked elevation was found of TNF, IFN-gamma, IL-2, and IL-2R in BALF obtained from the grafted lungs in group 1 and group 2 dogs. The levels of these markers were significantly higher than those obtained from the normal, native lungs (P less than 0.05). Two of three recipients in group 2 had pneumonia in the native lungs on day 10 after single-lung transplantation. All markers except IFN-gamma in BALF obtained from the infected native lungs were also increased, but the titers were less than those obtained from the grafted lungs at the same time. There were significantly higher levels of TNF, IL-2, and IL-2R present in the BALF of grafted lungs of dogs in group 1 than group 2 (P less than 0.05). In group 3, BALF levels of these markers from the grafted lungs were not significantly different from those of the normal and native lungs during the period of CsA treatment after single-lung transplantation. On various days after discontinuation of CsA treatment, BALF levels of all markers began to rise. Abnormal levels of BALF markers obtained from the grafted lungs heralded the appearance of abnormalities detected by chest x-ray films. Our study suggests that serially measuring BALF levels of TNF, IFN-gamma, IL-2, and IL-2R may serve as a useful means in monitoring the immunologic status of canine lung allografts and in the early detection of lung allograft rejection. The role of BALF IFN-gamma in distinguishing lung allograft rejection from pulmonary infection needs further studies.

Increased expression of MHC class II antigens in rejecting canine lung allografts.

Expression of major histocompatibility complex class II antigens was investigated in the normal lungs and in lung allografts of mongrel dogs after single-lung transplantation. Cryostat sections were stained with an indirect immunoperoxidase technique that used B1F6 and 7.5.10.1 as anti-MHC class II monoclonal antibodies. In the normal lungs and native lungs of the recipient dogs after single-lung transplantation, only some cells of lymphoid tissue and macrophages/dendritic cells were MHC class II-positive. During acute rejection, increased infiltration with MHC class II-positive cells in perivascular, peribronchial, and interstitial areas and intraalveolar spaces was found in lung allografts. In addition, expression of MHC class II antigens was induced on the bronchial epithelium and vascular endothelium. Induced expression of MHC class II antigens on the bronchial epithelium and vascular endothelium in rejecting lung allografts was found as early as two days after single-lung transplantation. The intensity of MHC class II antigen expression on bronchial epithelium and vascular endothelium in graft lungs increased with the progression of rejection response and directly correlated with the bronchoalveolar lavage fluid (BALF) levels of biochemical markers, as tumor necrosis factor alpha, gamma-interferon (IFN-gamma), interleukin 2 (IL-2) and soluble interleukin 2 receptor (SIL-2R). Abnormal expression of MHC class II antigens on bronchial epithelium and vascular endothelium and abnormal elevation of BALF levels of the cytokines in lung allografts could be prevented by cyclosporine (CsA) treatment. Our results suggested that MHC class II antigen expression could be induced on the bronchial epithelium and vascular endothelium of canine lung allografts during acute rejection. This abnormal expression of MHC class II antigens on bronchial epithelium and vascular endothelium of graft lungs may serve as a specific index for diagnosis of lung allograft rejection when infection as an inducing factor can be excluded. Furthermore, bronchial epithelium and vascular endothelium of lung allografts have become MHC class II-positive, and are likely to be the targets for low-grade rejection, resulting in the development of bronchiolitis obliterans and occlusive vascular disease in lung allografts.

The effect of cyclosporine on expression of class II major histocompatibility complex antigens on bronchoalveolar cells and peripheral blood mononuclear cells.

To evaluate the effect of cyclosporine (CsA) on the expression of class II major histocompatibility complex (MHC) antigens on bronchoalveolar cells (BAC) and peripheral blood mononuclear cells (PBMC), BAC and PBMC were obtained from mongrel dogs before and during CsA treatment. Expression of MHC class II antigens on BAC and PBMC were detected by monoclonal antibodies (Mabs) B1F6, 7.5.10.1 and Q5/13, which recognized canine MHC class II antigens, using cytofluorometry. Total cell counts and cell differentials of canine BAC showed no significant difference before or during CsA treatment (P greater than 0.05). Anti-MHC class II Mabs used in this study reacted with 21-51% of canine BAC and with 31-69% of PBMC. After stimulation with phytohaemagglutinin (PHA) the percentages of MHC class II positive BAC and PBMC were significantly increased (P less than 0.001). Whole blood levels of CsA were 315 +/- 76 (mean +/- SD) ng/ml and 343 +/- 57 ng/ml on days 7 and 14 during CsA treatment at an oral dose of 20 mg/kg/day. During CsA treatment there was no significant difference in the percentages of MHC class II positive BAC and PBMC compared with data obtained before CsA treatment (P greater than 0.05). We likewise failed to observe a suppressive effect of CsA on the increased expression of MHC class II antigens on BAC and PBMC induced by PHA (P greater than 0.05). In summary, at an oral dose of 20 mg/kg/day for a period of two weeks, our results show that: (1) CsA does not affect the total cell counts and cell differentials of canine BAC; (2) CsA does not reduce the basal expression of MHC class II antigens on canine BAC and PBMC; (3) CsA does not suppress the increased expression of MHC class II antigens on canine BAC and PBMC induced by PHA.

MHC class II antigens on canine bronchoalveolar cells.

To evaluate the expression of MHC (major histocompatibility complex) antigens on canine bronchoalveolar cells (BAC), bronchoalveolar lavages (BAL) were performed in mongrel and German shepherd dogs. MHC class II antigens on canine BAC and peripheral blood mononuclear cells (PBMC) were detected by monoclonal antibodies (mAbs) B1F6, 7.5.10.1 and Q5/13 recognising canine MHC class II antigens, using cytofluorometry. These mAbs reacted with more than 20% of BAC and PBMC in both breeds of dog. The percentage of MHC class II positive cells in BAC were lower than those in PBMC. There was no significant difference in the percentages of MHC class II positive BAC and PBMC in mongrel and German shepherd dogs. To further identify the expression of MHC class II antigens on BAC, the cells were separated into adherent and nonadherent cells by petri dish adherence. The percentages of MHC class II positive cells in adherent and non-adherent cell populations were similar. Nearly half the lymphocytes in normal BAC were T cells detected by mAbs F3-20-7 and 1A1; B cells were scarce and represented less than 10% of nonadherent cells. Immunoprecipitation by anti-MHC class II mAbs, and SDS-polyacrylamide gel electrophoresis (SDS-PAGE) revealed MHC class II-like molecules on canine BAC and PBMC. After stimulation with phytohaemagglutinin (PHA), the percentages of class II positive cells in BAC and PBMC were significantly increased. Thus, these anti-MHC class II mAbs may prove to be of advantage in experiments designed to evaluate the changes in class II antigen expression on canine BAC during the course of immune response in the lung, as in pulmonary allograft rejection.

Clinical role of bronchoscopy in adults with intrathoracic tuberculous lymphadenopathy.

Twenty-five adult tuberculosis patients with intrathoracic lymphadenopathy were studied. Intrathoracic tuberculous lymphadenopathy seems rare in Chinese and affects more older and female subjects. The most common symptoms were cough, followed by chills, fever and the most common physical finding was peripheral lymph node enlargement. The roentgenographic appearance of mediastinal lesions varied but often included right paratracheal involvement. Nine patients had clear lungs. Tuberculous involvement was limited to the lower lung field in seven out of 16 patients with concomitant parenchymal lesions. The remaining nine patients had pulmonary tuberculosis involving the upper lobes. Consolidation was the most common form of pulmonary lesion. A diagnosis was made on the basis of sputum examination in nine patients; however, peripheral lymph node examination yielded a higher diagnostic rate (90 percent). Endobronchial involvement was proved by bronchoscopy in 12 of 16 patients. In three instances, the final diagnosis could be documented after mediastinoscopy or exploratory thoracotomy.

Lower lung field tuberculosis.

Sixty-five patients with lower lung field tuberculosis were found, representing 5.1 percent of the total admissions with pulmonary tuberculosis over a period of five years. Unlike previous reports, the disease affects more within the old age and female groups. The most common symptoms were cough, followed by chills, fever and hemoptysis. Bilateral or bilobar involvement was infrequent. Common basal segments and middle lobe were the most commonly affected locations. Chest x-ray film showed consolidation in most cases. Sputum smear for AFB was positive in 37 patients. Endobronchial involvement was proved by bronchoscopy in 32 of 42 patients who received the diagnostic procedure. The major bronchoscopic findings were ulcerative granuloma, fibrostenosis, and submucosal infiltration. In rare instances, final diagnosis could be made only after exploratory thoracotomy. Besides its diagnostic merit in lower lung field tuberculosis, bronchoscopy can assess the severity of the endobronchial lesion and provide a guide to early surgical intervention in patients with severe fibrostenosis.

Postural effect on gas exchange in patients with unilateral pleural effusions.

The effect of body position (right and left lateral decubitus positions) on arterial oxygen tension (PaO2) and the relationship between this postural effect on gas exchange and pulmonary function were evaluated in 21 patients who had unilateral pleural effusions without roentgenographic and bronchoscopic evidence of bronchopulmonary disorders. Our results indicated that a positional influence on gas exchange existed in these patients. We failed to find a consistent relationship between the size of effusion estimated by chest roentgenogram and alterations in PaO2 during different positions. Postural change did affect gas exchange in the patients with unilateral pleural effusions and this postural effect on gas exchange was highly correlated with their FEV1 and FVC. This may be of clinical significance in managing such patients.

Chest roentgenographic guidelines in the selection of patients for fiberoptic bronchoscopy.

We conducted this study to define the value of fiberoptic bronchoscopy (FOB) in the evaluation of chest radiographic abnormalities and to provide guidelines for fiberoptic bronchoscopy on the basis of chest radiographic appearances. Fiberoptic bronchoscopy without fluoroscopy was carried out in 530 patients, 455 male and 75 female, aged 19 to 85 years, during a 1-year period at Chest Department, Veterans General Hospital, Taipei. Of 530 patients, 19 (3.6 percent) had normal chest radiographs, and the remaining 511 (96.4 percent) patients had abnormal chest radiographs. Overall diagnostic yield of FOB was 55.4 percent in patients with abnormal chest radiographs and 52.6 percent in patients with normal chest radiographs. On the basis of radiographic findings, patients with lobar collapse (87.0 percent), hilar abnormalities (81.8 percent), pericardial effusions (66.7 percent), mass lesions (> 4 cm) (65.7 percent), and pleural effusions (64.9 percent) were most frequent to obtain a positive diagnosis via bronchoscopy (p < 0.001). Of 530 patients; mass lesion was the most frequent abnormality on bronchoscopy and had the highest incidence of providing a positive diagnosis (36.2 percent) (p < 0.001). A predilection of mass lesion on bronchoscopy was seen for chest radiographic features of lobar collapse (64.8 percent) and mass (> 4 cm) (47.0 percent) (p < 0.001). Of 19 patients with normal chest radiographs, a correct diagnosis was made in 4 (21.1 percent) with bronchoscopic findings of mass lesions, 3 (15.8 percent) with endobronchial abnormalities, and 3 (15.8 percent) patients with abnormal bronchial mucosa. Indeed, the decision to perform bronchoscopy should be guided by many factors other than chest radiograph. In this study, however, emphasis has been placed on the incidence of positive diagnosis via bronchoscopy on the basis of chest radiographic patterns. In this respect, we believe that in patient with lobar collapse, hilar abnormality, pericardial effusion, mass lesion (> 4 cm), and pleural effusion on the chest radiograph bronchoscopy should be considered.

Tracheal bronchus associated with lung cancer: a case report.

Tracheal bronchus is a rarely found congenital bronchial anomaly. It usually originates from the right lateral wall of the trachea at the level < 2 cm above the tracheal bifurcation. The patients usually are asymptomatic, but some may experience recurrent pneumonia, chronic bronchitis, or bronchiectasis. It is very rare for a malignant tumor to grow from this aberrant bronchus. There are only four cases of lung cancer developing from the tracheal bronchus reported in the world literature, and we present a fifth case.