[Assessment of induction therapy and resection in stage IIIb non-small cell lung cancer].

Twelve patients with stage IIIb non-small cell lung cancer underwent induction therapy and resection from January 1990 to July 1998. They were divided into two groups; group A (n = 5) received two (to four) preresectional cisplatin and videsine chemotherapy, group B (n = 7) received chemoradiotherapy (radiation with concurrent low-dose-daily cisplatin). All patients in both groups had clinically down-stage and had no major side effects preventing surgery. 3 patients underwent radical pneumonectomy and 9 patients had radical lobectomy with no operative mortality. In 9 patients the disease was pathologically downstaged. Overall five-year survival was 27%, while in group A it was 50%. In group B 2-year survival was 18% and the longest survivor had pulmonary recurrence four years after surgery. Our data show better prognosis in group A than in group B. This results suggest that chemotherapy may be superior pre-resectional therapy to chemoradiotherapy.

[Bronchial lipoma with extrabronchial growth].

A 69-year-old woman was admitted to our hospital with a faint infiltrative shadow in the right middle lung field on chest X-ray in August 1996. In addition to inflammatory changes in right S2 and S3, an intrabronchial elliptical mass with a low CT number (mean number:-144 HU), was noted in the right upper bronchus on chest high resolution computed tomogram (HRCT). Fiberoptic bronchoscopy revealed a yellowish-orange polypoid lesion in the right upper bronchus, and bronchial biopsy demonstrated proliferation of fat tissue in the submucosa. Bronchial lipoma was subsequently diagnosed. Because HRCT findings indicating extrabronchial growth of the tumor, surgical resection was performed in October 1996, when extrabronchial growth of the tumor was confirmed. When extrabronchial growth of a bronchial tumor is suspected based on CT findings, surgical treatment should be considered even for a benign bronchial tumors.

[Nodular bronchioloalveolar carcinoma with multiple small air spaces caused by bronchiolectasis].

A 67-year-old man was admitted to our hospital with a faint abnormal shadow in the right S2 on January 1995. Chest CT showed a faint abnormal shadow about 3 cm in diameter with multiple small air spaces. He was admitted again 18 months later for surgical treatment because the shadow on chest X-ray had grown. Right upper lobectomy was performed in June 1996 and pathohistological examination revealed bronchioloalveolar carcinoma. Tumor cells along the walls of the alveolus were recognized only in the periphery of the lesion. The center of the lesion was fibrotic and multiple small air spaces ranging from 0.5 mm to 10 mm in diameter were present. One cause of these air spaces was considered to be the "check valve" mechanism, but the majority of the air spaces were derived from ectatic bronchioli. These results suggested that bronchiolectasis had developed with central fibrosis only in the tumor. Central fibrosis in this case had played a significant role in determining the radiographic appearance of the lesion.

Involvement of various combinations of endogenous inflammatory cytokines in Listeria monocytogenes-induced expression of inducible nitric oxide synthase in mice.

Using a in vitro infection of spleen cells with Listeria monocytogenes, the relationship between endogenous cytokines and the expression of inducible nitric oxide synthase (iNOS) was examined. When all interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha and interleukin (IL)-1 alpha, or the combination of IFN-gamma with either TNF-alpha or IL-1 alpha were neutralized by antibodies, there was a significant reduction of iNOS expression and nitrite production in culture. However, there was no reduction of iNOS expression and nitrite production when these cytokines were individually neutralized. After the depletion of natural killer cells, there was no change in the expression of Listeria-induced iNOS and nitrite production although the IFN-gamma production was abrogated. Neutralization of TNF-alpha and IL-1 alpha in natural killer cell-depleted culture resulted in the reduction of iNOS expression. Thus, various combinations of cytokines to play an important role in iNOS induction by L. monocytogenes.

Suppression of IFN-gamma production from Listeria monocytogenes-specific T cells by endogenously produced nitric oxide.

The induction of nitric oxide (NO) by IFN-gamma has been well documented in a variety of experimental settings, but so far there has been no report on whether the endogenously produced NO can suppress IFN-gamma production. In the present study, CD4+ T cells from Listeria monocytogenes-immune mice produced IFN-gamma upon stimulation with specific antigen and NO was generated in culture. When NG-monomethyl-L-arginine (NMMA) was added to the culture at a dose sufficient for the complete blockade of NO production, there was a significant level of enhancement of IFN-gamma production, which was also dose dependently correlated with addition of NMMA. RT-PCR revealed that IFN-gamma mRNA per given amount of total RNA remained the same irrespective of NO blockade by NMMA; however, total RNA recovery was significantly higher in the culture with NMMA. The endogenously produced NO suppressed T-cell proliferation which can be restored by the addition of NMMA. Sodium nitroprusside, a spontaneous NO generator, inhibited T-cell proliferation dose dependently and suppressed IFN-gamma production. Taken together, it may be concluded that NO down-regulates IFN-gamma production mainly by inhibiting T-cell proliferation.

Induction of cytokine gene expression by listeriolysin O and roles of macrophages and NK cells.

To determine the role of listeriolysin O (LLO) of Listeria monocytogenes in the host response at the initial stage of infection, cytokine gene expression in mouse peritoneal exudate macrophages and spleen cells was examined by reverse transcription-PCR. Expression of various cytokine mRNAs, especially those of interleukin-1 (IL-1), tumor necrosis factor alpha, gamma interferon (IFN-gamma), and IL-12, was observed to occur in spleen cells after direct stimulation with an LLO preparation purified to a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Induction of mRNA expression by LLO was not blocked by cholesterol, which abrogated the hemolytic activity of LLO. After the depletion of NK cells in spleen cells by treatment with anti-asialo GM1 antibody plus complement, LLO-induced expression of IFN-gamma was decreased, indicating that NK cells were the main source of IFN-gamma. After depletion of macrophages by passing spleen cells over a Sephadex G-10 column, expression of macrophage-derived cytokines, including IL-1alpha, tumor necrosis factor alpha, and IL-12, was diminished. In addition, IFN-gamma mRNA expression was impaired, indicating that IFN-gamma mRNA expression from NK cells required signaling from macrophages. It is suggested that LLO is capable of inducing endogenous cytokines of mice, and both NK cells and macrophages are involved in the host cytokine response to LLO.

Correlation between the presence of virulence-associated genes as determined by PCR and actual virulence to mice in various strains of Listeria spp.

Five chromosomal genes, prfA, plcA, hlyA, mpl and plcB, are implicated in the virulence of Listeria monocytogenes and some of these genes have been used for the identification of bacteria by polymerase chain reaction (PCR). Using 6 strains of L. monocytogenes and 3 L. innocua strains, the relationship was examined between the presence of five virulence-associated genes and actual virulence to mice in terms of 50% lethal dose (LD50), bacterial viability in the organ of infected mice and the intracellular growth in cultured macrophages. None of the five genes could be amplified by PCR in all the L. innocua strains and they were actually avirulent to mice. All L. monocytogenes strains were shown to be virulent and to have intact virulence-associated genes except for the strain ATCC15313. This particular strain was revealed to be avirulent and defective in hlyA and plcA in PCR amplification. It was suggested that PCR detection of genes prfA, mpl, or plcB may not be sufficient to detect virulent strains of L. monocytogenes. It appeared that the ability to produce listeriolysin O (LLO), which is encoded by hlyA, was critical for the expression of virulence regardless of the amount of LLO produced.

Cytokine gene expression in mice at an early stage of infection with various strains of Listeria spp. differing in virulence.

By using reverse transcription-PCR, cytokine gene expression was examined in mice 24 h after infection with various strains of Listeria spp. differing in virulence as determined by in vivo growth and 50% lethal dose values. All the virulent strains of Listeria monocytogenes induced the expression of mRNAs specific for interleukin-1 alpha (IL-1 alpha), gamma interferon (IFN-gamma), and tumor necrosis factor alpha (TNF-alpha) in the spleen of mice, while an L. monocytogenes strain incapable of producing listeriolysin O and strains of Listeria innocua induced the expression of TNF-alpha mRNA only. The levels of expression of IL-1 alpha and IFN-gamma mRNAs were proportional to the levels of listeriolysin O produced by each strain. Those strains which induced the expression of IFN-gamma were capable of generating protective immunity in the infected host, suggesting that the virulence-related induction of some cytokine at the initial stage of infection plays a role in the induction of acquired cellular resistance to L. monocytogenes.

Detection of multiple virulence-associated genes of Listeria monocytogenes by PCR in artificially contaminated milk samples.

The inhibitory effect of milk in the PCR detection of Listeria monocytogenes could be overcome by washing the contaminated milk sample with phosphate-buffered saline and concentrating the bacteria to 1/10 of the original volume. In order to avoid a possible failure in the detection of virulent L. monocytogenes, a one-step procedure which enabled demonstration of three virulence-associated genes, prfA, hlyA, and plcB, simultaneously in a single PCR mixture was developed.