Probing endogenous collagen by laser-induced autofluorescence in burn wound biopsies: A pilot study.

The focus of the current study was to interrogate the predictive potential of laser-induced autofluorescence (LIAF) by objectively assessing collagen synthesis in burn wound granulation tissues ex vivo. Prior grafting, granulation tissues (20 samples) following burn injury were collected from 17 subjects of age range 18 to 60 years with patient/donor consent and the corresponding autofluorescence spectra were recorded at 325 nm He-Cd laser (≈2 mW) excitations. The resulting endogenous collagen intensity from the above tissue samples was computed by normalizing the nicotinamide adenine dinucleotide levels. In addition, the hydroxyproline content was also estimated biochemically from the same granulation tissues. A comparative assessment of both LIAF and biochemical estimations for endogenous collagen by hydroxyproline resulted in strong positive correlation among them. The above relevant observations suggest that LIAF is equally informative as that of biochemical estimations, in evaluating endogenous collagen content in wound granulation tissues. Thus, it can be concluded that LIAF has the predictive potential, as a noninvasive objective tool to measure the endogenous collagen levels in wound biopsy tissues and provide complementary data conducive for making clinical decisions.

Association between the extent of DNA damage in the spermatozoa, fertilization and developmental competence in preimplantation stage embryos.

OBJECTIVE: To examine the fertilizing ability and DNA damage response of preimplantation stage embryos derived from the γ-irradiated mouse sperm carrying varying amounts of DNA strand-breaks. MATERIAL AND METHODS: The DNA damage in the sperm was induced by exposing the testicular area to different doses of γ-radiation. After mating with healthy female mice, sperm zona binding, fertilizing ability of DNA damaged sperm and developmental competence of embryos derived from the DNA damaged sperm were assessed. RESULTS: The in vivo zona binding ability and fertilizing ability of DNA damaged sperm was significantly affected in the 5.0 and 10.0 Gy sperm irradiation groups. Although the development of the embryos derived from the DNA damaged sperm was not significantly affected until day 2.5 post-coitus, further development was significantly altered, as evidenced by the total cell number in the embryos. CONCLUSION: The sperm carrying DNA strand breaks still has the ability to fertilize the oocyte normally. However, the events like zona-binding and successful fertilization depend on the extent of sperm DNA fragmentation. The study has also showed a great heterogeneity in embryonic development at peri-implantation period with respect to the degree of sperm DNA damage.