采用DNA和蛋白质吸收带的Kubelka-Munk光谱函数对离体的人正常胃、 未分化胃腺癌、 胃鳞状细胞癌和低分化胃腺癌的上皮组织进行鉴别诊断。 实验采用带积分球附件的分光光度计获取组织的漫反射光谱。 结果表明： 在250～650 nm， 人胃的上皮组织的癌变导致未分化胃腺癌、 胃鳞状细胞癌和低分化胃腺癌等的上皮组织的Kubelka-Munk光谱函数f(ｒ∞)及其对数log［f(ｒ∞)］的平均值在DNA吸收带(260 nm)处都有非常显著性的差异， 其差异分别为68.5%(p＜0.05)， 146.5%(p＜0.05)， 282.4%(p＜0.05)和32.4%(p＜0.05)， 56.0%(p＜0.05)， 83.0%(p＜0.05)。 人胃的上皮组织的癌变导致未分化胃腺癌、 胃鳞状细胞癌和低分化胃腺癌等的上皮组织的Kubelka-Munk光谱函数f(ｒ∞)及其对数log［f(ｒ∞)］的平均值在蛋白质的吸收带(280 nm)处也都有非常显著性的差异， 其差异分别为86.8%(p＜0.05)， 262.9%(p＜0.05)， 660.1%(p＜0.05)和34%(p＜0.05)， 72.2%(p＜0.05)， 113.5%(p＜0.05)。 人胃的上皮组织的癌变导致未分化胃腺癌、 胃鳞状细胞癌和低分化胃腺癌等的上皮组织的Kubelka-Munk光谱函数f(ｒ∞)及其对数log［f(ｒ∞)］的平均值在β-胡萝卜素吸收峰(480 nm)处也有着显著的差异性， 其差异分别为59.5%(p＜0.05)， 73%(p＜0.05)， 258.9%(p＜0.05)和118.7%(p＜0.05)， 139.2%(p＜0.05)， 324.6%(p＜0.05)。 可见， 人胃上皮组织的癌变导致其DNA、 蛋白质和β-胡萝卜的含量都发生了显著的变化。 这结论为快速、 低成本、 非入侵的胃癌的光活检及鉴别诊断胃癌提供有益参考。

Differential diagnosis for epithelial tissues of normal human gastric, undifferentiation gastric adenocarcinoma, gastric squamous cell carcinomas, and poorly differentiated gastric adenocarcinoma were studied using the Kubelka-Munk spectral function of the DNA and protein absorption bands at 260 and 280 nm in vitro. Diffuse reflectance spectra of tissue were measured using a spectrophotometer with an integrating sphere attachment. The results of measurement showed that for the spectral range from 250 to 650 nm, pathological changes of gastric epithelial tissues induced that there were significant differences in the averaged value of the Kubelka-Munk function f(ｒ∞) and logarithmic Kubelka-Munk function log［f(ｒ∞)］ of the DNA absorption bands at 260 nm between epithelial tissues of normal human stomach and human undifferentiation gastric cancer, between epithelial tissues of normal human stomach and human gastric squamous cell carcinomas, and between epithelial tissues of normal human stomach and human poorly differentiated cancer. Their differences were 68.5%(p＜0.05), 146.5%(p＜0.05), 282.4%(p＜0.05), 32.4%(p＜0.05), 56.0%(p＜0.05) and 83.0%(p＜0.05) respectively. And pathological changes of gastric epithelial tissues induced that there were significant differences in the averaged value of the Kubelka-Munk function f(ｒ∞) and logarithmic Kubelka-Munk function log［f(ｒ∞)］ of the protein absorption bands at 280 nm between epithelial tissues of normal human stomach and human undifferentiation gastric cancer, between epithelial tissues of normal human stomach and human gastric squamous cell carcinomas, and between epithelial tissues of normal human stomach and human poorly differentiated cancer. Their differences were 86.8%(p＜0.05), 262.9%(p＜0.05), 660.1%(p＜0.05) and 34%(p＜0.05), 72.2%(p＜0.05), 113.5%(p＜0.05) respectively. And pathological changes of gastric epithelial tissues induced that there were significant differences in the averaged value of the Kubelka-Munk function f(ｒ∞) and logarithmic Kubelka-Munk function log［f(ｒ∞)］ of the β-carotene absorption bands at 480 nm between epithelial tissues of normal human stomach and human undifferentiation gastric cancer, between epithelial tissues of normal human stomach and human gastric squamous cell carcinomas, and between epithelial tissues of normal human stomach and human poorly differentiated cancer. Their differences were 59.5%(p＜0.05), 73%(p＜0.05), 258.9%(p＜0.05), 118.7%(p＜0.05), 139.2%(p＜0.05), and 324.6%(p＜0.05) respectively. It is obvious that pathological changes of gastric epithelial tissues induced that there were significant changes in the contents of the DNA, protein and β-carotene of gastric epithelial tissues. The conclusion can be applied to rapid, low-cost and noninvasive the optical biopsy for gastric cancer and provides a useful reference.