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Query: UMLS:C0242379 (lung cancer)
 71,905 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In photodynamic therapy (PDT), a sensitizer, light, and oxygen are used to cause photochemically induced cell death. The mechanism of cytotoxicity involves generation of singlet oxygen and other free radicals when the light-excited sensitizer loses or accepts an electron. Although selective retention of sensitizer by malignant tissue is seen in vivo, the mechanisms for this sensitizer targeting remain unclear. The first-generation sensitizers are porphyrin based and vary in lipophilicity and hydrophilicity. Targeting of the vasculature seems to be a prominent feature of the cytotoxic effect of these sensitizers in vivo, with resulting necrosis. Treatment depth varies with the wavelength of light that activates the sensitizer used, and the second-generation sensitizers are activated at longer wavelengths, allowing for a 30% increase in treatment depths. The selectivity of targeting can be increased when the sensitizer is delivered with the use of liposomes or monoclonal antibodies specific for tumor antigens. Studies have demonstrated direct effects of PDT on immune effector cells, specifically those with lineage from macrophages or other monocytes. Clinically, this therapy has been chiefly used for palliation of endobronchial and esophageal obstruction, as well as for treatment of bladder carcinomas, skin malignancies, and brain tumors. The future of PDT rests in defining its use either as an intraoperative adjuvant to marginal surgical procedures or as a primary treatment for superficial malignancies. Phase III trials in esophageal cancer and lung cancer are in progress and will help in evaluation of whether Photofrin II, the most widely used sensitizer, can be added to the oncologic armamentarium, pending approval from the U.S. Food and Drug Administration.
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PMID:Photodynamic therapy in oncology: mechanisms and clinical use. 844 72

A man with primary lung cancer developed respiratory failure due to lymphangitis carcinomatosis that was diagnosed by transbronchial lung biopsy specimen. After combination chemotherapy with high-dose etoposide and cisplatin (CDDP), he was able to cease oxygen therapy and showed improvement of his lymphangitis carcinomatosis. He received a total dose of 13,400 mg/m2 of etoposide. This case suggested that respiratory failure due to lymphangitis carcinomatosis can be a treatable condition.
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PMID:Respiratory failure due to pulmonary lymphangitis carcinomatosis. 844 10

Evidence supports the potential role of beta-carotene in cancer prevention. Basic research has demonstrated that beta-carotene can trap organic free radicals and/or deactivate excited oxygen molecules which may have an anticancer effect by preventing tissue damage. Although observational epidemiologic studies are not entirely consistent, many show an inverse association between dietary intake or blood levels of beta-carotene and subsequent cancer risk. Two large-scale randomized trials of beta-carotene have been completed. A Finnish trial demonstrated no benefit of beta-carotene among middle-aged male smokers, with those assigned to this supplement in fact experiencing an increased risk of lung cancer. However, because of the long latency period for cancer, which may be a decade or more, the six-year duration of treatment in this trial may have been inadequate to detect an anticancer effect. A Chinese trial demonstrated a modest reduction in cancer mortality from a combined regimen of beta-carotene, vitamin E, and selenium. The effect of the individual agents could not be assessed, and because the trial was carried out among a nutritionally deficient population, its results may not have direct relevance to well-nourished individuals. Several additional large-scale trials of beta-carotene are ongoing. The Physicians' Health Study, which is testing beta-carotene among 22,071 US male physicians, will have an average duration of treatment of 12.5 years at its scheduled termination in late 1995. Data in women will be available from the Women's Health Study, which began in 1992, and will randomize approximately 40,000 US female health professionals.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:beta-carotene and cancer chemoprevention. 853 2

Occupational exposure to silica has often been associated with the development of pulmonary fibrosis and, occasionally, lung cancer. Their development may be mediated by oxidant-induced cellular injury. The short- and long-term effects of a single intratracheal instillation of silica in rats (10 mg/200 microliters/saline per rat) was assessed by measuring 8-hydroxy-2'-deoxyguanosine (oh8dG) levels in lung tissue and peripheral blood leukocytes. Cell differentials, reduced glutathione (GSH), and superoxide dismutase (SOD), lipid peroxide, and total phospholipids in peripheral blood and/or bronchoalveolar lavage fluid (BALF) were also measured. The pulmonary oh8dG levels increased approximately 2.24- 2.86-fold from 1 to 5 days after exposure to silica. It was still elevated 1 and 4 weeks after installation, but the difference was no longer statistically significant. The oh8dG levels in peripheral blood leukocytes were never significantly different, but they were generally higher than in the controls. The low SOD levels in the BALF of exposed rats in the early stage and the higher GSH levels in the late stage may represent protective reactions against the generation of oxygen species. A significant increase in oh8dG levels in lung tissue suggested the possible carcinogenicity of silica.
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PMID:Oxidative DNA damage induced by silica in vivo. 860 69

This investigation was effected to determine the levels of the two antioxidant enzymes, superoxide dismutase (SOD) (EC 1.15.1.1) and catalase (CAT) (EC 1.11.1.6) in lung cancerous tissues and to compare with normal lung tissue in order to evaluate the antioxidant status in lung cancer. Fifteen lung carcinoma tissue samples and the normal counterparts from the same cases were homogenized and the cytosols obtained by ultracentrifugation (100,000 x g). SOD was assayed using a modification of the indirect nitroblue tetrazolium assay method, while CAT was measured by a spectrophotometric method. The data obtained are as follows: 1.42 +/- 0.24 U/mg protein (means +/- SEM) of SOD in lung cancer and 3.13 +/- 0.51 U/mg protein in normal lung tissue and 33.53 +/- 6.09 U/mg protein of CAT in lung cancer and 71.33 +/- 14.38 in normal lung tissue. The differences were found to be significant at the level of P < 0.01 for both enzymes. These low levels of the antioxidant enzymes in lung cancerous tissues can lead to elevated levels of reactive oxygen metabolites, resulting in damage to the key subcellular structures such as DNA, cell membranes, and other vital cellular components.
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PMID:Evaluation of some antioxidant enzymes in lung carcinoma tissue. 863 62

Several models attempt to explain the synergistic increase in lung cancer among workers exposed to asbestos fibers, who were smokers at the same time. It is known that reactive oxygen species (ROS) are important mediators in asbestos-induced diseases, especially cancer. We studied quantitatively the formation of ROS (by spin trapping with DMPO) in aqueous buffer suspensions containing crocidolite (UICC), chrysotile (UICC and commercial, long fibers) alone, and in combination with aqueous cigarette tar extracts. It was observed that asbestos and cigarette tar act in a cooperative or synergistic way in the generation of hydroxyl radical spin adducts. Grinding of asbestos fibers and addition of EDTA (iron chelator) enhanced the intensity of the ESR signal. This enhancement progressed with time, probably due to the reaction of the extracted iron with the slow released hydrogen peroxide from tar extracts. It was observed a fivefold increase in the ESR signal (for crocidolite and aqueous tar extracts) in the formation of hydroxyl radicals via an iron-catalyzed Fenton reaction. These experimental results are suggest to be strong evidence to the fact that lung cancer has been found in asbestos workers exposed to high concentrations of fibers in the working environment who were smokers, and only rarely in nonsmokers.
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PMID:A study of the synergistic interaction of asbestos fibers with cigarette tar extracts for the generation of hydroxyl radicals in aqueous buffer solution. 872 34

Chronic respiratory failure is defined on the basis of gas exchange in the lung. Recent studies have suggested serious clinical problems in patients with disabling dyspnea not necessarily related to gas exchange. Home oxygen therapy not only prolongs life expectancy but also improves the quality of daily life. In Japan, pulmonary emphysema, sequelae of pulmonary tuberculosis, and interstitial pneumonia/pulmonary fibrosis are the 3 major diseases currently treated by home oxygen therapy. Respiratory failure caused by interstitial pneumonia/pulmonary fibrosis and lung cancer is on the increase and is also treated by home oxygen therapy. Clinical problems on mechanisms and treatment of chronic respiratory failure are reviewed from recent data.
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PMID:Current status and research on chronic respiratory failure in Japan. 883 92

We report on a patient who underwent a left pneumonectomy for a second primary lung cancer after a right upper lobectomy and upper chest wall resection for a superior sulcus tumor. Although the postoperative course was complicated by sputum retention which required a temporary tracheostomy the outcome was good and the patient is now living without supplementary oxygen supply. Left pneumonectomy may be considered in patients with previous contralateral lobectomy when the preoperative evaluation of the patient shows an acceptable predicted postoperative pulmonary function. A long-term cure and a good quality of life must, however, be offered.
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PMID:Left pneumonectomy for a second primary tumor after right upper lobectomy for superior sulcus tumor. 885 1

The effects of cytokines (interleukin-2, tumor necrosis factor-alpha and interferon-gamma) on the ability of peripheral blood monocytes and alveolar macrophages to produce oxygen radicals were examined by the chemiluminescence assay in patients with lung cancer. Oxygen radical production by peripheral blood monocytes before stimulation with cytokines was lower in the lung cancer group than in healthy controls, suggesting reduced immune function in lung cancer patients. However, the activity in the lung cancer group was elevated to the control level when the monocytes were stimulated by any of the three aforementioned cytokines. Oxygen radical production by alveolar macrophages did not differ significantly between nonstimulated monocytes from lung cancer patients and those from healthy controls. In the lung cancer group, stimulation of the macrophages with any of the three cytokines elevated their ability to produce oxygen radicals to the same extent as in the control group. The results suggest that stimulation of macrophages by interleukin-2, tumor necrosis factor-alpha or interferon-gamma can exert an antitumor action in patients with lung cancer.
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PMID:Effects of cytokines on oxygen radical production by peripheral blood monocytes and alveolar macrophages in patients with lung cancer. 889 Sep 75

We have experienced three elderly cases who underwent thoracoscopic surgery for lung cancer complicated by emphysema. Cases 1, 2 and 3, respectively aged 76, 78 and 80 years, had required the oxygen therapy preoperatively. Allowing for poor pulmonary reserve, a thoracoscopic partial pulmonary resection for lung cancer combined with Nd-YAG laser pneumoplasty for emphysema was designed. The respective values of forced expiratory volume in one second (FEV 1.0) for cases 1 and 2 increased from 470 and 820 to 860 and 1620 ml. Reductions in residual volumes (RV) for cases 1, 2 and 3 were from 2770, 4940 and 5230 to 2370, 4500 and 3250 ml. The degrees of respiratory failure in the Hugh-Jones classification for cases 1, 2 and 3 were up-graded from V, IV and IV, respectively, to III, II and II, postoperatively. In conclusion, our thoracoscopic treatment, designed for elderly patients with poor pulmonary reserve, allows improvement of emphysema as well as resection of lung cancer.
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PMID:Thoracoscopic surgery for lung cancer complicated by emphysema in elderly patients. Report of three cases. 902 82


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