Full-face ALA-PDT for facial actinic keratosis: Two case reports.

We reported two cases of full-face 5-aminolevulinic acid-photodynamic therapy (ALA-PDT) for facial multiple actinic keratosis (AK). After the full-face ALA-PDT, we observed that the AK lesions on the faces of the patients were completely cleared and facial rejuvenation was achieved. In our follow-up, one patient was free of recurrence for over 13 months and the other one for over 28 months. The experience of these two cases may indicate that full-face ALA-PDT has an excellent therapeutic effect while potentially preventing the recurrence of AK.

The effect of 595 nm pulsed dye laser on connective tissue growth factor (CTGF) expression in cultured keloid fibroblasts.

OBJECTIVE: To investigate the effect of pulsed dye laser (PDL 595 nm) on the proliferation and expression of connective tissue growth factor (CTGF) in cultured keloid fibroblasts. MATERIALS AND METHODS: Cultured keloid fibroblasts were exposed to pulsed dye laser irradiation at fluences of 6, 8, and 10 J/cm(2) , with pulse durations of 1.5, 3, and 10 ms. The viability of keloid fibroblasts was measured with CCK-8 at 72, 24, and 12 hours prior to irradiation. Subsequently, viability was measured at 12, 24, and 72 hours post-irradiation. Additionally, the fibroblast cell cycle and apoptosis rate were measured by flow cytometry. Finally, keloid fibroblasts underwent real-time polymerase chain reaction (PCR) and Western blot to investigate the CTGF mRNA and protein expression after PDL irradiation. The untreated cultured keloid fibroblasts served as controls. RESULTS: The proliferation of keloid fibroblasts was significantly inhibited after PDL irradiation. Both CTGF mRNA and protein expression were significantly down-regulated in 1.5, 3, and 10 ms pulse duration groups, in a dose dependent manner (P < 0.05). However, there was no statistically significant difference between groups of different pulse duration in 6, 8, and 10 J/cm(2) fluence ranges (P > 0.05). CONCLUSIONS: Within certain fluence ranges, pulsed dye laser can effectively suppress the growth of keloids and significantly down-regulate CTGF mRNA and CTGF expression.

The effect of flashlamp pulsed dye laser on the expression of connective tissue growth factor in keloids.

OBJECTIVE: To investigate connective tissue growth factor (CTGF) expression before and after pulsed dye laser (PDL, 595 nm) treatment, and to better understand the mechanism of PDL treatment of keloids. METHOD: Twenty-six patients with keloids were recruited for this study. For each patient, two keloids of similar anatomic location, duration, texture, and appearance were chosen for study; one of these keloids was treated and the other served as a control. Three sessions of PDL treatment, with pulse duration of 1.5 milliseconds, spot size 7 mm, DCD duration 20 milliseconds/delay 10 milliseconds and fluence of 10 J/cm(2), were performed on the keloids at 3- to 4-week intervals. Punch biopsies were performed both on the treated and untreated keloids prior to the first treatment and after the final treatment. The specimens underwent realtime polymerase chain reaction (PCR) and immunohistochemistry (IHC) to investigate the CTGF mRNA and protein expression after PDL treatment. RESULTS: According to realtime PCR, the CTGF mRNA was significantly down-regulated after PDL treatment in 80.77% of patients as compared to the control group. IHC investigation showed that after treatment the CTGF positive cells also significantly decreased in number as compared to the control group in 80.77% of patients. Using the Vancouver scar scale (VSS), there was an average decrease of 20.85 ± 12.33% after PDL treatment. CONCLUSIONS: Pulsed dye laser treatment of keloids significantly down-regulates the expression of CTGF in most cases. This may partially explain the mechanism of action of PDL treatment of keloids.

Ultrafast excited state dynamics of modified phthalocyanines: p-HPcZn and p-HPcCo.

Two modified metallophthalocyanines (MPcs) containing sulfonic naphthoxy substituents were synthesized. The measurements of transient absorption and time-resolved photoluminescence were used to study the ultrafast response and excited state dynamics of two MPcs in dimethyl sulfoxide (DMSO) solution, which were predominantly in the monomeric form. Under excitation at 400 nm, these molecules experience vibrational relaxation to the bottom of the first excited state and then the excitation rapidly converts to the low-lying charge-transfer (CT) state and finally reaches the triplet states. Under excitation at 800 nm, they show a two-photon absorption character, and their excited state dynamics exhibit strong dependence on the probe wavelength. The main results with 400 nm pumping are similar to the results with 800 nm pumping. For p-HPcZn, weak two-photon photoluminescence was also observed with a lifetime of 52 +/- 2 ps. A four-level model was used to illustrate the excited state dynamics of p-HPcZn, while a five-level model was suggested for p-HPcCo molecule.

The ultrafast dynamics and nonlinear optical properties of tribranched styryl derivatives based on 1,3,5-triazine.

By using the femtosecond laser spectroscopic techniques, we have studied the ultrafast response and the nonlinear optical properties of three molecules with donor-acceptor structure (denoted as T01, T02, and T03). Two-photon absorption (2PA) cross sections measured by the open aperture Z-scan technique were determined to be 77, 90, and 410 GM for T01, T02, and T03, respectively. The relaxation dynamics of the excited states were measured by two-color femtosecond pump-probe and time-resolved photoluminescence (PL) experiments. By changing the solvent from chloroform (CHCl3) to dimethyl sulfoxide (DMSO), the transient dynamics was found changed significantly and the decay time of PL emission decreased dramatically because DMSO with large dipole moment accelerates the cross-transfer process and the nonradiative process in the molecules.