Search

Background: Gastric cancer is one of the most common cancers in Japan. The use of endoscopy is increasing, along with the number of histological examinations of specimens obtained by endoscopy. However, it takes several days to reach a diagnosis, which increases the medical expense. Raman spectroscopy is one of the available optical techniques, and the Raman spectrum for each molecule and tissue is characteristic and specific. The present study investigated whether Raman spectroscopy can be used to diagnose gastric cancer., Methods: A total of 251 fresh biopsy specimens of gastric carcinoma and non-neoplastic mucosa were obtained from 49 gastric cancer patients at endoscopy. Without any pretreatment, the fresh specimens were measured with a near-infrared multichannel Raman spectroscopic system with an excitation wavelength of 1064 nm, and Raman spectra specific for the specimens were obtained. A principal component analysis (PCA) was performed to distinguish gastric cancer and non-neoplastic tissue, and a discriminant analysis was used to evaluate the accuracy of the gastric cancer diagnosis., Results: The Raman spectra for cancer specimens differed from those for non-neoplastic specimens, especially at around 1644 cm(-1). Sensitivity was 66%, specificity was 73%, and accuracy was 70%. The accuracy of diagnosis using the single Raman scattering intensity at 1644 cm(-1) was 70%, consistent with the PCA result., Conclusions: The present results indicate that near-infrared multichannel Raman spectroscopy with a 1064-nm excitation wavelength is useful for gastric cancer diagnosis. Establishment of a Raman diagnostic system for gastric cancer may improve the clinical diagnosis of gastric cancer and be beneficial for patients.

We report a case of primitive neuroectodermal tumor (PNET) arising in the transverse colonic mesentery. A 24-year-old Japanese woman was admitted to Kagoshima City Hospital with complaints of abdominal pain and sensations of abdominal fullness of 5 months' duration. On palpation, a mass the size of an infant's head was noted in the right flank. Abdominal computed tomography (CT) and ultrasonography showed a huge mass that consisted of multiple cystic components. On arteriography, a slight tumor stain appeared, with stretched and displaced tributaries of the right colic and middle colic arteries. Barium swallow examination demonstrated that the ascending colon was shifted to the right and small intestine to the left. We performed an en-bloc resection of the tumor in the transverse colonic mesentery, including the ascending colon, proximal jejunum (20 cm in length), and greater omentum. The resected tumor was 12 x 10 x 7 cm in size, 590g in weight, elastic soft in consistency, and multicystic. Histologically, the specimens showed a sheet-like proliferation of spindle-to-polygonal cells, and focally, the tumor formed rosette structures. Immunohistochemically, the tumor cells were positive for neuron-specific enolase (NSE) and mic-2. EWS-FLI1 chimeric mRNA was detected by reverse transcriptase-polymerase chain reaction (RT-PCR). Based on the above findings, we finally diagnosed the tumor as PNET of the colonic mesentery. There has been no recurrence for 20 months after operation. PNET arising in the mesentery is very rare, and we distinguished PNET from other tumors by immunohistochemical examination and by demonstration of the presence of EWS-FLI1 chimeric mRNA in the tumor.

Factors that affect serum levels of 7 alpha-hydroxycholesterol were studied in the rat. Serum levels of 7 alpha-hydroxycholesterol differed in male and female rats fed regular chow (male; 0.2 +/- 0.1 nmol/ml (mean +/- SD); n = 8; female; 0.4 +/- 0.1 nmol/ml; n = 8). When rats were fed with chow to which 3% cholestyramine had been added, the level increased significantly, particularly in female rats (male; 0.6 +/- 0.3 nmol/ml; n = 8; female; 2.4 +/- 1.5 nmol/ml; n = 8). The liver activity of cholesterol 7 alpha-hydroxylase, the rate-limiting enzyme for degradation of cholesterol, did not show any sex differences, irrespective of whether the animals were fed with regular chow (male; 51 +/- 15 pmol/min per mg protein; n = 8; female; 58 +/- 21 pmol/min per mg protein; n = 8), or the cholestyramine-supplemented chow (male; 162 +/- 33 pmol/min per mg protein; n = 8; female; 172 +/- 33 pmol/min per mg protein; n = 8). In contrast, the activity of 3 beta-hydroxy-delta 5-C27-steroid dehydrogenase, which acts after cholesterol 7 alpha-hydroxylase in the catabolism of cholesterol, showed a marked difference between the sexes. In both sexes this enzyme activity was higher in cholestyramine-treated rats (male; 963 +/- 78 pmol/min per mg protein; n = 8; female; 708 +/- 106 pmol/min per mg protein, n = 8) compared to that in that rats received regular chow (male; 622 +/- 83 pmol/min per mg protein; n = 8; female; 469 +/- 41 pmol/min per mg protein; n = 8). If the serum level of 7 alpha-hydroxycholesterol depended solely on the enzyme activity of cholesterol 7 alpha-hydroxylase, it would be difficult to explain these sex differences, since there were no sex differences in levels of cholesterol 7 alpha-hydroxylase. These results clearly indicate that, in the rat, the serum level of 7 alpha-hydroxycholesterol depends not only on cholesterol 7 alpha-hydroxylase activity but also on 3 beta-hydroxy-delta 5-C27-steroid dehydrogenase activity.