Comparative study of 1064 nm nanosecond, 1064 nm picosecond, 755 nm, and 595 nm lasers for tattoo removal: An essential role by macrophage.

OBJECTIVES: Tattoo removal is in high demand, and many types of lasers can be used for tattoo removal. Macrophages play an important role in the persistence of tattoos. However, comparative studies of the efficacy of tattoo removal with different lasers versus the relationship between the destruction of pigment particles or recruitment of macrophages after laser treatment are lacking. MATERIALS AND METHODS: Tattoo models were established on the rat dorsal surface and randomly treated with 1064 nm nanosecond, 1064 nm picosecond, 755 nm, and 595 nm lasers for one session. Clinical photographic evaluation, melanin index, hematoxylin and eosin staining, identification of macrophages by CD68 staining, and transmission electron microscopy were conducted at different time points. RESULTS: Regardless of the pulse duration, all lasers included were effective for the removal of black tattoos, with 1064 nm lasers having the best efficacy, followed by 755 and 595 nm lasers. The diameter of the pigment particles and recruitment of dermal macrophages correlated with the efficacy of tattoo removal. CONCLUSIONS: In this study, the 1064 nm lasers were found to be the most effective for black tattoo removal. However, there was no significant difference between the 1064 nm picosecond and the nanosecond lasers. Macrophage recruitment plays an essential role in pigment metabolism during laser-tattoo removal.

Dynamic expression profiles of MMPs/TIMPs and collagen deposition in mechanically unloaded rat heart: implications for left ventricular assist device support-induced cardiac alterations

Left ventricular assist devices (LVADs) ameliorate heart failure by reducing preload and afterload. However, extracellular matrix (ECM) deposition after application of LVADs is not clearly defined. The purpose of the present study was to investigate ECM remodeling after mechanical unloading in a rat heart transplant model. Sixty male Lewis rats were subjected to abdominal heterotopic heart transplantation, and the transplanted hearts were pressure- and volume-unloaded. The age- and weight- matched male Lewis rats who had undergone open thoracic surgeries were used as the control. Left ventricle ECM accumulation and the expression/activity of matrix metalloproteinases (MMPs) and tissue inhibitor of matrix metalloproteinases (TIMPs) were measured on the third, seventh, and fourteenth days after transplantation/sham surgery. Compared with the control group, myocardial ECM deposition significantly increased on the seventh and fourteenth days after heart transplantation (P < 0.05) and peaked on the 14th day. The gelatinase activity as well as mRNA expression of MMP-2 and MMP-9 significantly increased after transplantation (P < 0.05). Both mRNA and protein levels of TIMP-1 and TIMP-2 significantly increased compared with those of the control group. Mechanical unloading may lead to adverse remodeling of the ECM of the left ventricle. The underlying mechanism may due to the imbalance of the MMP/TIMP system, especially the remarkable upregulation of TIMPs in the pressure and volume unloaded heart (AU)

Dynamic expression profiles of MMPs/TIMPs and collagen deposition in mechanically unloaded rat heart: implications for left ventricular assist device support-induced cardiac alterations.

Left ventricular assist devices (LVADs) ameliorate heart failure by reducing preload and afterload. However, extracellular matrix (ECM) deposition after application of LVADs is not clearly defined. The purpose of the present study was to investigate ECM remodeling after mechanical unloading in a rat heart transplant model. Sixty male Lewis rats were subjected to abdominal heterotopic heart transplantation, and the transplanted hearts were pressure- and volume-unloaded. The age- and weight- matched male Lewis rats who had undergone open thoracic surgeries were used as the control. Left ventricle ECM accumulation and the expression/activity of matrix metalloproteinases (MMPs) and tissue inhibitor of matrix metalloproteinases (TIMPs) were measured on the third, seventh, and fourteenth days after transplantation/sham surgery. Compared with the control group, myocardial ECM deposition significantly increased on the seventh and fourteenth days after heart transplantation (P < 0.05) and peaked on the 14th day. The gelatinase activity as well as mRNA expression of MMP-2 and MMP-9 significantly increased after transplantation (P < 0.05). Both mRNA and protein levels of TIMP-1 and TIMP-2 significantly increased compared with those of the control group. Mechanical unloading may lead to adverse remodeling of the ECM of the left ventricle. The underlying mechanism may due to the imbalance of the MMP/TIMP system, especially the remarkable upregulation of TIMPs in the pressure and volume unloaded heart.