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Significance: Hyperspectral imaging (HSI) is an emerging optical technique that has a double function of spectroscopy and imaging. Aim: Near-infrared hyperspectral imaging (NIR-HSI) (900 to 1700 nm) with the help of chemometrics was investigated for gastric cancer diagnosis. Approach: Mean spectra and standard deviation of normal and cancerous pixels were extracted. Principal component analysis (PCA) was used to compress the dimension of hypercube data and select the optimal wavelengths. Moreover, spectral angle mapper (SAM) was utilized as chemometrics to discriminate gastric cancer from normal. Results: Major spectral difference of cancerous and normal gastric tissue was observed around 975, 1215, and 1450 nm by comparison. A total of six wavelengths (i.e., 975, 1075, 1215, 1275, 1390, and 1450 nm) were then selected as optimal wavelengths by PCA. The accuracy using SAM is up to 90% according to hematoxylin–eosin results. Conclusions: These results suggest that NIR-HSI has the potential as a cutting-edge optical diagnostic technique for gastric cancer diagnosis with suitable chemometrics.

Significance: The diagnostic depth of photodynamic diagnosis (PDD) for gastric cancer with protoporphyrin IX (PpIX) is limited, which leads to missing intramucosal cancers in screening and surgery. Aim: The reason is that the excitation light, whose wavelength is determined by the highest absorption peak of PpIX (∼405 nm), is strongly attenuated by mucosal tissues. We investigated an excitation wavelength that can extend the diagnostic depth of PpIX fluorescence at the mucosal subsurface. Approach: By calculating the depth-dependent intensity of the excitation light in porcine gastric mucosa for each wavelength, relationships among the wavelength, fluorophore depth, and fluorescence intensity were assessed and fluorescence images of PpIX pellets located at different fluorophore depths were compared experimentally by changing the excitation wavelength. Results: The numerical calculation showed that a 505-nm excitation light provided the highest fluorescence intensities at a fluorophore depth deeper than 1.1 mm. In the fluorescence observation, the fluorescence intensities at fluorophore depths of 0 and 1.0 mm at 405 nm were 5.4 × 103 and 1.0 × 103 arb. units, whereas those at 505 nm were 5.3 × 101 and 1.9 × 102 arb. units, respectively. Conclusion: The experimental results suggest that the diagnosis depth of PDD with PpIX for intramucosal cancer can be extended by 505-nm excitation light.

Positron emission tomography with (18)F-fluoro-2-deoxyglucose is an imaging technology that is demonstrating increasing utility in the evaluation of gastrointestinal malignancies.

Objectives Studies have indicated an excess risk of stomach cancer, pancreas cancer, and non-Hodgkin's lymphoma for sulfite pulp mill workers, and therefore cancer incidence was evaluated for 2 Danish sulfite mills. Methods Altogether 2238 workers employed in 1955--1990 were included in a historic cohort and followed until 31 December 1993. National cancer rates were used to calculate the expected number of cancer cases. Results The overall cancer risk was close to the expected, the standardized incidence ratio (SIR) being 1.01. The risk of stomach cancer was doubled [10 observed, SIR 1.99, 95% confidence interval (95% CI) 0.95--3.66], as was the risk of pancreatic cancer (7 observed, SIR 1.88, 95% CI 0.75--3.88). For the men with known pulp exposure, lung cancer was slightly increased (SIR 1.53, 95% CI 0.94--2.37). Other cancers with elevated risks were leukemia (7 observed, SIR 1.84) and soft-tissue sarcomas (4 observed, SIR 2.37). The risk of non-Hodgkin's lymphoma was not increased. Conclusion The excess risk of stomach cancer and pancreatic cancer found in this study was in accordance with that of other studies from sulfite pulp mills.

In an earlier case-referent study from a soft-paper mill with levels of paper dust exceeding 5 mg/m3, an increased mortality was found (OR = 3.8, p ≤ 0.05) from asthma and chronic obstructive pulmonary disease (COPD) among the employed. Furthermore, other studies on paper mill workers have also indicated an increased mortality from lung cancer. The main objectives of the present case-referent study were to investigate the mortality from asthma, COPD, and lung cancer in two other Swedish paper mills. In these mills, the levels of paper dust have been below 3 mg/m3. The subjects for the study were all men who died between 1961 and 1985 from asthma and COPD (n = 31), respiratory cancer (n = 27), and stomach cancer (n = 33) selected in three parishes surrounding two paper mills. As referents we randomly selected about six times as many men who had died from nonmalignant nonrespiratory diseases in these parishes (n = 550). On the basis of information found in the personnel records in the mills, the men were classified into different occupational categories or as unexposed. No increased risk of asthma or COPD was found among the workers exposed to paper dust. However, it was found that there was significantly increased mortality (OR = 5.7, p ≤ 0.05) for asthma and COPD among workers in a previous log sorting department. The study also showed a significantly increased risk of lung cancer (OR = 2.1, p ≤ 0.05) among maintenance workers. There was no increased risk of stomach cancer in the study. The results from the study suggest that maintenance workers at paper mills have an increased risk of developing lung cancer, which may be an effect of earlier asbestos exposure. The increased risk for asthma and COPD among the log sorters merits further investigation. In the present study, exposure to low concentrations of paper dust was not found to increase the mortality from asthma or COPD.

The results of various epidemiological research indicate that workers in the pulp and paper industry have an increased risk of developing and dying of malignant cancer with a specific location. The paper discusses recent studies in the area. The findings point to an increased risk of stomach cancer in workers occupationally exposed to pulp produced in the sulfite process. Workers making paper and cardboard are especially at risk for lung cancer. Some researchers signal a higher risk of lymphatic system cancer and stoma cancer. On the basis of existing data on exposure in the pulp and paper industry, it is impossible to determine the exact effects of exposure to a given compound or chemical. Assessment of exposure at particular work areas and analysis of data using the job exposure matrix is necessary. This should provide more information about cancerogenic compounds in the pulp and paper industry.

Three human tumor cell lines derived from an osteosarcoma (OHA cells), a bladder carcinoma (EJ cells), and a gastric sarcoma (SHAC cells) were passaged serially in the presence of human interferon-alpha (IFN-alpha) for extended periods of time. The long-term IFN-alpha treatment induced a partial reversion of OHA tumor cell phenotype as exemplified by inhibition of cell proliferation, lack of cellular overlapping in confluent cultures and marked reduction in tumorigenicity. In contrast, under the same conditions, long-term IFN treatment did not reverse but even potentiated some of the phenotypic characteristics (including tumorigenicity) of EJ and SHAC cells. In the three tumor cell lines, the transforming ability, genomic level, or expression of activated oncogenes, c-Ki-ras, c-Ha-ras, and N-ras, respectively, were unaltered with long-term IFN-alpha treatment. Our data indicate that IFN-induced phenotypic changes are not necessarily associated with changes in oncogene expression.

Mortality among 2,113 U.S. and Canadian members of the Pulp, Sulfite, and Paper Workers' Union, 1935 through 1964, was studied using a proportionate mortality analysis. Mortality due to gastric cancer was found to be elevated in all jurisdictions, but only in mills using sulfate or sulfite pulping. An excess of mortality due to kidney cancer was limited to mills in Oregon and Washington. Excesses of deaths due to leukemia, Hodgkin's disease, and lymphosarcoma were observed only in mills in Oregon, Washington, and Wisconsin and the province of Quebec. Based on small numbers, excesses of deaths due to cancers of rectum, pancreas, kidney, and lymphosarcoma were seen primarily among sulfite process workers, while Hodgkin's disease deaths occurred primarily in sulfate (kraft) process workers. These findings suggest that cancer mortality in pulp and paper workers may be related both to pulping process and to tree species processed.