Obestatin and cardiovascular health.

Obestatin, encoded by the same gene as ghrelin, was first described as a physiological opponent of ghrelin through an interaction with the orphan receptor GPR39. However, the effects of obestatin were not totally contrary to the effects of ghrelin in cardiovascular regulations based on the recent studies. We summarize here the current evidences surrounding the cardiovascular actions of obestatin, and the possible implications of obestatin as a therapeutic agent in common conditions such as hypertension and heart failure.

[Preparation of DNA silver nanowire and its Raman spectra].

Silver nanoparticles were synthesized by the method of combining heating with UV irradiation. In the authors' work, the shape and size of nanograins which carry positive electrical charges are uniform and their average diameter is 7.8 nm. Based on the electrostatic self-assembly characteristics of DNA, silver nanoparticles were equally assembled on predefined aligned calf thymus DNA to form DNA silver nanowires. The diameter of the wires is about 30 nm and the length is 2 microm. The Raman spectra indicate that the silver nanoparticles mainly attach to the backbone chain of DNA and affect the vibration properties of deoxyribose and base. The intensity of the peaks at 782 and 1 098 cm(-1) assigned to stretch vibration of phosphoric skeleton decreases sharply and the band at 782 cm(-1) shifts to 791 cm(-1). The bands of deoxyribose C-O stretch vibration at 1 011 and 1 050 cm(-1) shift to 1 030 and 1 064 cm(-1) respectively. The characteristic peaks of bases at 1 372, 1 334, 1 304 and 728 cm(-1) shift to 1 368, 1 320, 1 294 and 731 cm(-1), respectively.

Raman spectra of single cell from gastrointestinal cancer patients.

AIM: To explore the difference between cancer cells and normal cells, we investigated the Raman spectra of single cells from gastrointestinal cancer patients. METHODS: All samples were obtained from 30 diagnosed as gastrointestinal cancer patients. The flesh tumor specimen is located in the center of tumor tissue, while the normal ones were 5 cm away from the outside tumor section. The imprint was put under the micros-cope and a single cell was chosen for Raman measurement. All spectra were collected at confocal Raman micro-spectroscopy (British Renishaw) with NIR 780 nm laser. RESULTS: We measured the Raman spectra of several cells from gastrointestinal cancer patients. The result shows that there exists the strong line at 1 002 /cm with less half-width assigned to the phenylalanine in several cells. The Raman lines of white cell were lower and less, while those of red cell were not only higher in intensity and more abundant, but also had a particular C-N breathing stretching band of pyrrole ring at 1 620-1 540 /cm. The line at 1 084 /cm assigned to phosphate backbone of DNA became obviously weaker in cancer cell. The Raman spectra of stomach cancer cells were similar to those of normal cells, but the Raman intensity of cancer cells was much lower than that of normal cells, and even some lines disappear. The lines of enteric cancer cells became weaker than spectra above and many lines disappeared, and the cancer cells in different position had different fluorescence intensity. CONCLUSION: The Raman spectra of several cells from cancer patients show that the structural changes of cancer cells happen and many bonds rupture so that the biological function of cells are lost. The results indicate that Raman spectra can offer the experiment basis for the cancer diagnosis and treatment.

[Raman spectra of cell from breast cancer patients].

Raman spectra of normal and cancer cell from breast cancer patients a represented. It is reported that all of the Ramanlines become weak. The intensities of Raman lines 782 and 1 084 cm(-1) of DNA phosphate group and 1 155 and 1 262 cm(-1) of deoxyribosephosphate decrease. The spectral lines 812 cm(-1) of A-type DNA and 979 and 668 cm(-1) disappear, and the 905 cm(-1) peak is shifted to lower frequency by 6 cm(-1). This means that the phosphate backbone of DNA is destroyed to a certain extent and the fissiparity of cancer cell can't be controlled effectively. In addition, the authors found a kind of Raman line 960 cm(-1) concerning calcificationand sclerosis of cancer cell. The results indicate that Raman spectra may offer the experiment basis for the cancer diagnosis and treatment.

[Temperature dependence of collagen by Raman spectra].

Raman spectra of collagen I at different temperature were obtained. There was no change at 1003 cm(-1) line, 1302 cm(-1) line moved to a higher wave number, but other lines moved to lower wave number when temperature increased. In addition, the authors observed the temperature dependence of Raman intensity and four denaturation points at 0, 40, 68 and 90 degrees C respectively. The points at 40 and 68 degrees C are in agreement with the experimental data by DSC and SHG. The point at 0 degrees C might be frozen transition; the point at 90 degrees C might be related to the damage of secondary structure. When heated to 150 degrees C, the Raman intensity of all bands decreased rapidly and many lines disappeared.

[Resonance Raman spectra of single red-cell from human blood].

Resonance Raman spectra of single red-cell from human blood are presented by different laser sources. It is reported that there is 1002 cm(-1) line of insensitive conformation of phenylalanine aromatic ring stretching and 1620 cm(-1) line of C-N breathing stretching band of pyrrole ring, which cause strong and sharp resonance lines when excited by 782 nm laser source. They are weaker and the intensity of other lines of high wave number is large and clear when excited by 514 nm laser source. But the intensity of lines of low wave number is strong and clear when excited by 782 nm laser source. At the same time, the authors got Raman spectra lines at different times after taking blood under the same laser source. When using 782 nm laser source, there is no difference except for 1601 cm(-1). There are a lot of weakened lines and lines shifting about 4-10 cm(-1) toward low wave number. The results indicate that Raman spectra may offer the experimental basis for studying structure, function and variability of single red-cell.