Spectroscopic insights into the Photoreduction of Cytochrome c with UVA-Vis Light Irradiation.

With the particular conjugation structure in the heme prosthetic group, Cyt c shows unusual functions similar to chlorophyll while irradiated by specific wavelength of UV-Vis lights. To further reveal mechanism of the photo-irradiation of Cyt c, we then studied various external factors that may influence the photo induced process. The absorbance intensity increase of band (317 nm) and Q band (520 nm and 549 nm)indicated Cyt c in phosphate-buffered saline within N2 atmosphere was photoreduced to Fe(II) Cyt c. Irradiated by 410 nm, the photoreduction process was facilitated by Met. But Trp, Tyr and Phe impeded the process due to their light absorbance abilities. In addition, the results of fluorescence and CD spectra indicated that the microenvironment polarity of Trp residue varied during the photoreduction process. And the secondary structure of Cyt c changed with lower α-helix/ßsheet ratio. The photoreduction mechanism of Cyt c was intramolecular electron transfer and porphyrin cation radicals were generated. The protein structure of Cyt c changed as well as part of the photoreduction.

Bowel control of anus-preserving operation for low rectal cancer in elderly patients over 75 years / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To evaluate the bowel control of the anus-preserving operation for elderly patients over 75 years with low rectal cancer.</p><p><b>METHODS</b>Thirty-nine elderly patients over 75 years with low rectal carcinoma (4-7 cm from anal verge) were treated during the study period. The patients were divided into different groups according to the surgical procedures and anastomotic locations. The bowel control and patients satisfaction were compared.</p><p><b>RESULTS</b>The time of recovering normal defecation frequency was (9.8+/- 2.9) months. There were no differences in bowel control and anorectal manometric findings between the lower anastomosis group and super-lower anastomosis group, the lower anastomosis group and anorectal anastomosis group. The patients in anorectal anastomosis group displayed significantly better bowel control and anorectal manometric findings than those in the super-lower anastomosis group (P< 0.05). The time of recovering normal defecation frequency in colonic J-pouch-anal anastomosis group was (7.7+/- 1.7) months, shorter than (10.6+/- 2.8) months in direct anastomosis group (P< 0.01). The complication rate of I degree incontinence was 36.1%, but there was no difference between the two groups. The anorectal manometric findings were better in J-pouch-anal anastomosis group than those in direct anastomosis group (P< 0.05).</p><p><b>CONCLUSION</b>Colonic J-pouch-anal anastomosis for lower rectal carcinoma can significantly improve the bowel control in a short term without increasing the complication rate.</p>