[Research on Early Diagnosis of Gastric Cancer by the Surface Enhanced Raman Spectroscopy of Human Hemoglobin].

Early diagnosis have great positive effect on the treatment of gastric cancer patients. Raman spectroscopy can provide a useful monitor for hemoglobin dynamics. Besides, Raman spectroscopy has notable advantages in the fields of abnormal hemoglobin diagnosis, hemoglobin oxygen saturation deter mination and blood methemoglobin analysis. In this paper, novel silver colloid was synthesized by microwave heated method. The surface enhanced Raman spectrums of hemoglobin from 11 normal persons and 20 gastric cancer patients are measured and analyzed in order to obtain spectrums which are high repeatability and characteristic peaks protruding. By analyzing the assignations of the SERS bands, it found that the content of asparagine, tyrosine and phenylalanine in the hemoglobin are significantly lower than healthy people. Discussing the structure of hemoglobin, when hemoglobin combines with oxygen, Fe²âº is in a low spin state, ionic radius shrinks and moves 0. 075 nm and fall into the pore in the middle of the heme porphyrin ring plane. This spatial variation affects F8His connected with the iron, will narrow the gap between the globin in the two strands of the helix, as a result, HC2 tyrosine pushed out of the void. Using this mechanism, the absorption peak of 1 560 cm⁻¹ confirmed that the tyrosine content in patients with gastric cancer was lower than that of normal people. Principal component analysis(PCA) is employed to get a three-dimensional scatter plot of PC scores for the health and cancer groups, and it can be learned that they are distributed in separate areas. By using the method of discriminate analysis, it is found that the diagnostic algorithm separates the two groups with sensitivity of 90.0% and diagnostic specificity of 90.9%, the overall diagnostic accuracy was 90.3%. The results from this exploratory study demonstrate that, SERS detection of oxyhemoglobin combined with multivariate analysis would be an effective method for early diagnosis of gastric cancer.

[Research on early diagnosis of esophageal cancer by Raman spectroscopy of human hemoglobin].

The Raman spectrums of hemoglobin from 20 normal persons and 21 esophageal cancer patients were measured and analyzed in the present paper, the results show obvious differences between the Raman spectrums of esophageal cancer patients and normal persons. Compared with normal persons, there are more iron ions in low spin state and less in high spin state in the hemoglobin of esophageal cancer patients. It indicates that some iron ions in high spin state turned to low spin state because of cancerization, and this experimental result coincides with the fact that hemolysis is more likely to occur in cancer patients. Principal component analysis (PCA) was employed to get a three-dimensional scatter plot of PC scores for the health and cancer groups, and it can be learned that they are distributed in separate areas. By using the method of discriminate analysis, it was found that the diagnostic algorithm separates the two groups with sensitivity of 90.5% and diagnostic specificity of 95%, and the overall diagnostic accuracy was 92.7%. The results from this exploratory study demonstrate that Raman spectroscopy combined with multivariate analysis would be an effective method for early diagnosis of esophageal cancer.

[Analysis of surface enhanced Raman scattering spectra of oxyhemoglobin for liver cancer with combined multivariate statistics].

Investigation of surface-enhanced Raman spectra of oxyhemoglobin for 30 liver cancers and 30 normal persons based on the silver nanofilm was reported. Principal components analysis (PCA) and independent variable T test were employed to develop effective diagnostic algorithms for distinguishing liver cancer form normal. Discriminant analysis was used to evaluate the diagnostic efficiency and the result indicates that SERS spectra of the oxyhemoglobin are obviously different between normal persons and liver cancers. PCA and independent variable T test were employed to get a three-dimensional scatter plot of PC scores for the healthy and cancer groups, and it can be learned that they are distributed in separate areas. By using the method of discriminate analysis, it was fount that the diagnostic algorithm separates the two groups with sensitivity of 96.7% and diagnostic specificity of 90%, the overall diagnostic accuracy was 93.3%. By analyzing the assignations of the SERS bands, it was found that the content of asparagine, tyrosine and phenylalanine in the hemoglobin are significantly lower than healthy people. The results from this exploratory study demonstrate that SERS detection of oxyhemoglobin for liver cancers based on the method of PCA combined with independent variable T test is expected to develop into a new type of liver cancer diagnostic tool.

[Raman spectra study on radiation damage in EC9706 cells by 60Cogamma-rays].

Raman spectrum was used to study the structure and content of protein, nucleic acid and fat, while EC9706 cells irradiated by 60Co gamma-ray were cultivated for 24 h. The results showed that for spectrum intensity and frequency deviation, there were big differences between each exposure group and control group. For the 1 244 cm(-1) peak of amide III, beta folder changed to disordered conformations in the middle dose (4, 5Gy) groups. The 1 341 cm(-1) peak of v (the indole ring of Trp) was red-shifted in every dose group. There was a 2-3 cm(-1) red shift at the 782 cm(-1) peak in the big dose groups (7, 8Gy). It was showed that the non-hydrogenation of v(s)(PO2-) was strengthened due to big dose gamma-rays radiation. There was a 4 cm(-1) blue shift at the 1 446 cm(-1) peak of delta (CH2, CH3). It maybe resulted from 60Co gamma-rays' damage to the film of EC9706 cells. The preferable dose of 60Co gamma-rays may be found by analyzing the variety of the above-mentioned peaks in some dose groups.

[Study on absorption spectra of cell substrate for Hep-2 cell after being radiated by X-ray].

UV-absorption spectra of the Hep-2 cell's culture medium RPMI1640 (10% Foetal Calf Serum) were collected by UV-3101 spectrophotometer after the Hep-2 cell was radiated by X-ray and cultivated for 24, 48 and 72 h, and the absorbability of the proteins in the substrate was analyzed. From these results it was found that there were visible differences among these absorption spectra. In particular, the absorption peaks of the RPMI1640 culture medium during the cultivation shifted from 233 to 235 nm, while the absorption peak at 278 nm became more and more smooth and even finally disappeared with the cultivation time. On the other hand, the absorption intensity of the different-dose groups rose greatly with the time, and were all lower than the control group until the cells were cultivated for 72 h after being radiated by X-ray. It was showed that the content of each amino acid has already changed. That is, during the growing course of the cancer cells, the tryptophan and casein were not depleted equivalently. And there were some important relations between the absorption spectra and the cells' apoptosis and necrosis induced by X-ray. This will be a foundation for the study of the best X-ray dose for the larynx carcinoma.