Objective:To explore the severe complications, such as blindness, brain infarction and even death caused by cosmetic autologous fat filler injection and their underlying mechanisms.Methods:From May 2022 to October 2023, 64 male New Zealand rabbits were selected in the clinical laboratory of Shaanxi University of Chinese Medicine and divided into 8 groups with 8 rabbits in each group. They were divided into grinding fat group, fat granule group, fat lipid group and normal saline group, and each group was further divided into 0.2 ml group and 0.4 ml group. Fat was cut from the rabbit groin, then chopped or treated with collagenase I, and centrifuged to separate fat lipids and fat particles, as well as other tissues. The rabbit facial artery was exposed along the incision below the mandibular angle, and 0.2 or 0.4 ml of chopped fat, fat particles, and lipids were retrogradely injected into the facial artery in each group, and then the incision was closed under the microscope. Ophthalmic and neurological symptoms were observed and recorded after surgery, and visual electrophysiology and fundus microscopy were performed to verify visual acuity and fundus artery obstruction.Results:Two weeks after surgery, the incidence of ophthalmic symptoms in the 0.2 ml injection group was 100% in the grinding fat group, 62.5% in the fat granule group, 0 in the lipid group and 0 in the normal saline group. The complication rates of 0.4 ml embolic injection were 100%, 87.50%, 12.5% and 0, respectively. The incidence of neurological symptoms was 62.5%, 25.0%, 0 and 0, respectively. Mortality rates were 37.5%, 12.5%, 0 and 0 after injection of 0.2 ml, and 100%, 50%, 0 and 0 after injection of 0.4 ml, respectively.Conclusions:Animal models have shown that grinding adipose tissue without collagenase I treatment is more likely to cause serious complications, simple lipid entry into blood vessels does not block relevant arteries, and fat volume is positively correlated with the incidence of postoperative complications.

Autologous fat grafting has gained great popularity in aesthetic and reconstructive surgery. However, recent reports of severe complications after fat grafting are increasing, especially fat embolism. It should be paid much attention to the surgical processes as the treatment is extremely difficult. Here, we analyzed the vascular embolism associated complications after fat grafting, and summarized the risk factors as well as preventive measures.

Autologous fat grafting has gained great popularity in aesthetic and reconstructive surgery. However, recent reports of severe complications after fat grafting are increasing, especially fat embolism. It should be paid much attention to the surgical processes as the treatment is extremely difficult. Here, we analyzed the vascular embolism associated complications after fat grafting, and summarized the risk factors as well as preventive measures.

Objective:To observe the lipogenic or osteogenic differentiation of decellularized adipose matrix (DAM) in the periosteal microenvironment.Methods:From June 2020 to December 2020, adipose tissue obtained by human liposuction was prepared as DAM at the National Institute of Plastic Surgery. Six male SD rats of 4 to 6 weeks were selected and implanted into the subperiosteum of the rat parietal bone according to the same initial volume. After 12 weeks, adipogenesis and osteogenic differentiation of DAM were observed by gross specimens, histological staining, and immunofluorescence staining. Label-free quantitative protein mass spectrometry was used for detection of osteogenic-associated proteins in DAM.Results:Vascularization around the DAM was evident. Adipogenesis and angiogenesis were observed in DAM by H&E and Masson staining, while OCN immunofluorescence staining confirmed osteogenic differentiation of DAM. The osteogenic differentiation related proteins were screened by mass spectrometry.Conclusions:In the microenvironment of periosteum, DAM mainly differentiates towards adipose tissue, but a few of them havs the potential to differentiate towards osteogenesis, which might be related to some of the osteogenesis-related proteins contained in DAM.

Objective:To explore whether botulinum toxin A (BTX-A) can improve the retention rate of fat transplantation in fat breast augmentation.Methods:Each patient was divided into control side and experimental side according to the random number table in 14 patients studied. The experimental group received autologous fat and BTX-A combined transplantation on both sides of the breast, while the control side only received autologous fat transplantation. The fat was added with the same volume of normal saline as BTX-A in the control group. All patients were followed up and the effects of BTX-A were evaluated objectively via the comparison of the remained bilateral fat graft volumes that were obtained through a digital three-dimensional reconstructions technique. Moreover, the improvement of each breast appearance and complication were assessed by the physician and patients who were blinded to the recipient treatment assignment.Results:The outcome of the fat breast augmentation was evident for both groups at the follow-up with no evidence of fat embolism, vascular/nervous injury, infection and prolonged bruising. In one of the 14 patients (control group), fat liquefaction necrosis occurred in one side of the breast; after active treatment, it returned to normal, and three patients had different degrees of mass. The analysis on the three-dimensional reconstruction data and the assessments from both the physicians and patients showed significant differences in the fat graft retention volume between the BTX-A group (51.10±20.56)% and the control group (33.06±14.77)%. Nevertheless, there was no significant difference in the incidence of complications between the two sides.Conclusions:Autogenous fat breast augmentation is safe and effective. This study result has shown that BTX-A can significantly improve the retention rate of fat transplantation but cannot reduce the incidence of complications.

Objective:The study aimed to investigate the effect of exosomes derived from bone marrow mesenchymal stem cells (BMSC-Exo) in promoting angiogenesis of fat grafts by regulating Notch signaling pathway.Methods:Fat from the abdomen of a 30-year-old healthy female who received liposuction in the Department of Plastic Surgery of the First Affiliated Hospital of Air Force Military Medical University in August 2020 was collected. Fat transplantation models were established using 12 BALB/c nude mice, with 0.5 ml of processed fat particles injected into the left and right sides of the backs. 100 μl BMSC-Exo (50 μg) was injected into the left side of the back of nude mice once per week for 4 weeks after fat grafting, which was the exosome group. The right side of the back was injected with 100 μl of phosphate-buffered saline at the same time points for 4 weeks after fat grafting, which was the control group. The following items were observed: (1) Fat grafts were collected and weighed at 4 weeks and 8 weeks after transplantation, the retention rate was calculated. (2) HE staining and immunofluorescence staining of Perilipin A was used to visualize the structure and integrity of adipocytes at 8 weeks after transplantation. (3) At 8 weeks after transplantation, immunohistochemical staining was used to detect CD31 positive cells, calculate micro vessel density, detect Notch1 and Notch4 positive cells and calculate the proportion of positive area.(4) At 8 weeks after transplantation, the relative expressions levels of Notch1, Notch4 and VEGF mRNA in fat grafts were detected by real-time fluorescence quantitative PCR. The data were analyzed by Graphpad Prism 8.0. T-test was used for comparison between groups. P<0.05 indicated the difference was statistically significant. Results:(1) At 4 and 8 weeks after transplantation, the retention rates of adipose tissue wet weight in the control group were (41.15±9.68)% and (34.30±6.45)% respectively. The results in the exosome group were (61.77±10.98)% and (55.93±5.89)%, which were higher than those in the control group ( P<0.05). (2) At 8 weeks after transplantation, the structural integrity of adipocytes in the exosome group was better than the control group, with more neovascularization. There were more intact Perilipin A positive adipocytes in the exosome group and less in the control group. (3) At 8 weeks after transplantation, the density of micro vessels in the control group was 4.67±0.57, which was significantly lower than that in the exosome group (13.00±2.00, P<0.05). The proportion of Notch1 and Notch4 positive area per visual field in the control group was lower than that in the exosome group [(0.53±0.28)% vs. (1.67±0.11)%, (0.11±0.06)% vs. (1.20±0.24)%, P<0.05]. (4) The mRNA expression levels of Notch1, Notch4 and VEGF were 1.53±0.20, 1.50±0.26 and 2.56±0.55 in the exosome group, which were significantly higher than those in the control group (1.00+ 0.00) ( P<0.05). Conclusions:BMSC-Exo may promote angiogenesis and improve retention rate of transplanted fat grafts through the elevation of VEGF expression and the activation of Notch signaling pathway.

Objective:To investigate the immobilizing effect of full-thickness skin subcutaneous grafting on allogeneic full-thickness skin graft in rats.Methods:The experimental research method was used. The inbred male Brown-Norway rats ( n=10) and Lewis rats ( n=10) were used as donors and recipients respectively. After subcutaneously full-thickness separation of a 2.2 cm×2.2 cm area on the nape of the recipient rat, a full-thickness skin of 2.0 cm×2.0 cm taken from the abdomen of the donor rat was subcutaneously grafted, and the donor site was pulled together and sutured. The autologous skin over the allograft in the recipient rat was excised 5-6 d after grafting, and the stitches were removed 7 d after excision. Within 2 months after grafting, the feeding, activity, and survival of the donor and recipient rats, behavior of tearing and scratching the wounds of the recipient rats, the wound condition after autologous skin excision in recipient rats, and the survival and hair growth of the grafted allogeneic skin were observed. Results:Within 2 months after grafting, the donor and recipient rats all ate normally and could move freely with no abnormal death. No tearing or scratching of the wounds occurred in recipient rats. There was a small amount of exudation and partial epidermal desquamation after autologous skin excision in recipient rats. All transplanted allografts survived, which were free of infection and necrosis, with new hairs growing out smoothly.Conclusions:The immobilizing method of full-thickness skin subcutaneous grafting of allogeneic full-thickness skin graft in rats is simple and time-saving without postoperative dressing change, with reliable pressure fixation and high survival rate of skin grafts, which can be promoted for animal skin grafting models.

Objective:The study aimed to investigate the effect of exosomes derived from bone marrow mesenchymal stem cells (BMSC-Exo) in promoting angiogenesis of fat grafts by regulating Notch signaling pathway.Methods:Fat from the abdomen of a 30-year-old healthy female who received liposuction in the Department of Plastic Surgery of the First Affiliated Hospital of Air Force Military Medical University in August 2020 was collected. Fat transplantation models were established using 12 BALB/c nude mice, with 0.5 ml of processed fat particles injected into the left and right sides of the backs. 100 μl BMSC-Exo (50 μg) was injected into the left side of the back of nude mice once per week for 4 weeks after fat grafting, which was the exosome group. The right side of the back was injected with 100 μl of phosphate-buffered saline at the same time points for 4 weeks after fat grafting, which was the control group. The following items were observed: (1) Fat grafts were collected and weighed at 4 weeks and 8 weeks after transplantation, the retention rate was calculated. (2) HE staining and immunofluorescence staining of Perilipin A was used to visualize the structure and integrity of adipocytes at 8 weeks after transplantation. (3) At 8 weeks after transplantation, immunohistochemical staining was used to detect CD31 positive cells, calculate micro vessel density, detect Notch1 and Notch4 positive cells and calculate the proportion of positive area.(4) At 8 weeks after transplantation, the relative expressions levels of Notch1, Notch4 and VEGF mRNA in fat grafts were detected by real-time fluorescence quantitative PCR. The data were analyzed by Graphpad Prism 8.0. T-test was used for comparison between groups. P<0.05 indicated the difference was statistically significant. Results:(1) At 4 and 8 weeks after transplantation, the retention rates of adipose tissue wet weight in the control group were (41.15±9.68)% and (34.30±6.45)% respectively. The results in the exosome group were (61.77±10.98)% and (55.93±5.89)%, which were higher than those in the control group ( P<0.05). (2) At 8 weeks after transplantation, the structural integrity of adipocytes in the exosome group was better than the control group, with more neovascularization. There were more intact Perilipin A positive adipocytes in the exosome group and less in the control group. (3) At 8 weeks after transplantation, the density of micro vessels in the control group was 4.67±0.57, which was significantly lower than that in the exosome group (13.00±2.00, P<0.05). The proportion of Notch1 and Notch4 positive area per visual field in the control group was lower than that in the exosome group [(0.53±0.28)% vs. (1.67±0.11)%, (0.11±0.06)% vs. (1.20±0.24)%, P<0.05]. (4) The mRNA expression levels of Notch1, Notch4 and VEGF were 1.53±0.20, 1.50±0.26 and 2.56±0.55 in the exosome group, which were significantly higher than those in the control group (1.00+ 0.00) ( P<0.05). Conclusions:BMSC-Exo may promote angiogenesis and improve retention rate of transplanted fat grafts through the elevation of VEGF expression and the activation of Notch signaling pathway.

Objective To explore the significance of preoperative MRI in the detection of gynecomastia before surgery.Methods From November 2016 to August 2018,we used preoperative MRI to determine surgical options to treat 38 cases of adolescent and post-adolescent patients with gynecomastia.After operation we followed up the patients for 6 months to 1 year.Results The breast had good shape,smooth chest wall,natural contour,and no complications such as hematoma,nipple and areola sensory disturbance.No surgical traces remained in the chest and no recurrence occurred during the follow-up.All patients were satisfied with the surgical effect and chest wall shape.Conclusions Preoperative MRI can clearly show the type of breast development,the proportion of fat and breast tissue,to guide the clinical personalized design of surgical procedures.It can be used as a routine pre operative examination for gynecomastia.

Objective To assess the quantitative impact of the application of high-throughput sequencing worldwide on clinical virology.Methods The following records from 2000 to 2018 were collected from National Center for Biotechnology Information:The number of complete genome of virus records per year;the number of virus discovery articles per year;the number of virus quasi-species articles per year;the number of viral infection gene signature articles per year.The method of interrupted time series was applied to analyze the trends of those records.Results Since the sequencing centers worldwide began to transit from the Sanger sequencing to the high-throughput sequencing technology in 2008,the annual value of records mentioned above increased by 3.755,2.760,6.195 and 3.885 times respectively.The long-term trends of change of each record are as follows:the number of complete genome of virus records increased by 1639.991 per year (P＜0.001);the number of virus discovery articles increased by 83.091 per year (P＜0.001);the number of virus quasi-species articles increased by 2.509 per year (P＜ 0.001);the number of viral infection gene signature articles increased by 30.836 per year (P＜ 0.001).Conclusions In 2008,the sequencing centers worldwide began to apply high-throughput sequencing technology which led to continuous decrease of the cost for sequencing.It result ed in not only increasingly enriched applications in clinical virology but also a long-term positive impact on the advance of clinical virology.