OBJECTIVETo explore the differential expression of homeobox genes in the normal, wounded human fetal and adult skins and its significance in fetal scarless healing.

METHODSGene chips containing 14 000 human genes were used to investigate homeobox gene expressions of the normal, wounded human fetal and adult skins.

RESULTSThere were significant differences between the expression of homeobox genes, especially for PRX-2, HOXB13, HOXB6 and HOXB7.

CONCLUSIONSThe homeobox gene is in close relation to developmental biology. The different expressions and changes of homeobox genes in the normal, wounded human fetal and adult skin may be a primary cause of different wound healing between fetal and adult skin.

Adolescent ; Adult ; Animals ; Cells, Cultured ; Child ; Female ; Fetus ; Gene Expression ; Gene Expression Profiling ; Genes, Homeobox ; genetics ; Homeodomain Proteins ; genetics ; Humans ; Male ; Mice ; Mice, Inbred BALB C ; Oligonucleotide Array Sequence Analysis ; Skin ; Wound Healing ; genetics ; Young Adult

OBJECTIVETo explore the differences of PDGF and EGF expression in the wound healing between fatal and adult.

METHODSWith the established animal model of fetal scarless healing and the adult samples, an immunohistochemical technique was used to evaluate the expression of PDGF and EGF in the normal adult skin, normal fetal skin, and the process of their wound healing.

RESULTS1. The expression of the PDGF was not found in the fetal skin, but a mild amount of the PDGF was shown in the epidermis and the upper dermal layer 12 hours and 1 day after the wounding process. In the normal adult skin, expression of PDGF was shown in the dermal fibroblasts, macrophagocytes and blood capillaries, and a strong expression was presented during its wound healing process. 2. In the fetal skin, the expression of the EGF was seen in the epidermis, hair follicles, sebaceous glands and sweat glands, but there were no markedly changes during the wound healing. In the adult skin, a positive stain of the EGF was shown in the basal layer of the epidermis while the mild stain in hair follicles and sweat glands. The level of the expression became gradually decreasing with the time going in the wounded adult skin.

CONCLUSIONThe different expression of growth factors between fetal and adult skin in wound healing may be one of the important reasons that the fetal wound could produce scarless healing.

Adult ; Epidermal Growth Factor ; metabolism ; Epidermis ; metabolism ; Fetus ; Fibroblasts ; metabolism ; Hair Follicle ; metabolism ; Humans ; Platelet-Derived Growth Factor ; metabolism ; Skin ; injuries ; metabolism ; Sweat Glands ; metabolism ; Wound Healing

OBJECTIVETo investigate the expression of several homeobox genes during the wound healing in fetal and adult skin and their roles in fetal scarless wound healing.

METHODSThe expressions of PRX-2, HOXB13, HOX2.2 and HOX2.3 during wound healing in fetal and adult skin were determined with in situ hybridization.

RESULTS(1) PRX-2 positive expression could be identified in normal fetal and adult skin, especially in the fetus. But there was difference in location sites of the genes. The positive expression in normal fetal skin was mainly found in the peripheral cells at the hair shafts within dermal papilla layers and was also found in the epithelium. Nevertheless, weak positive expression of PRX-2 was found in the epithelial basal layer cells in normal adult skin but not in dermal tissue. There was strong positive expression of the PRX-2 in the tissue around the wound in fetus but not of that in adults except the epithelial basal layers. (2) Positive expression of HOXB13 could be identified in both normal fetal and adult skins. And the expression was concentrated mainly in hair follicle cells in the dermis and in the basal layer cells in the epithelium. Furthermore, the expression became weak after trauma, especially in fetal skin. (3) The positive expression of HOX2.2 and HOX2.3 in normal fetal skin was observed mainly in the whole layer of the epithelium and especially in the epithelial basal layers. Weak positive expression could be found in the dermis and strong expression found in the tissue near the wound. But there was no positive expression of the HOX genes in normal adult skin and wounds.

CONCLUSIONThe difference in the HOX expression in fetal and adult skin wound healing might be the key factor leading to different wound healing. Homeobox genes might be closely related with the developmental biology.

Adolescent ; Adult ; Animals ; Burns ; pathology ; Child ; Female ; Fetus ; Gene Expression ; Genes, Homeobox ; Homeodomain Proteins ; metabolism ; Humans ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Skin ; embryology ; Wound Healing ; genetics ; Young Adult

COVID-19 ; Dermatology ; Humans ; Inpatients ; SARS-CoV-2 ; Singapore

OBJECTIVE: To investigate the clinical efficacy of femoral neck system(FNS) and three cannulated compression screws(CCS) in the treatment of unstable femoral neck fractures in young adults. METHODS: The clinical data of 52 young and middle-aged patients with unstable femoral neck fractures admitted from August 2018 to August 2021 were reviewed and analyzed. All patients were divided into two groups according to the internal fixation method, 25 cases were treated with FNS fixation, 27 cases were treated with closed reduction and 3 CCS inverted triangular distribution. The operation time, incision length, intraoperative bleeding, hospitalization expenses and fracture reduction quality of two groups were recorded and compared;The patients were followed up regularly after operation. The fracture healing time, complete weight-bearing time and postoperative complications(nonunion, femoral neck shortening, femoral head necrosis) of two groups were compared. The Harris score was used to evaluate hip function 6 months after surgery. RESULTS: The operation was successfully completed in both groups. The patients in FNS group had more bleeding, longer incision length and higher hospitalization cost than CCS group(P<0.01). There ware no significant difference in operation time and Garden index between two groups(P>0.05). Patients in both groups were followed up for 6 to 32 months.The fracture healing time in FNS group was less than that in CCS group, the time of complete weight bearing after surgery was earlier than that in CCS group, and the hip Harris score was higher than that in CCS group (P<0.01). There were no internal fixation fracture complications in two groups during follow-up. In the FNS group, there were 4 cases of avascular necrosis of the femoral head and 2 cases of femoral neck shortening, of which 3 cases underwent total hip replacement due to avascular necrosis of the femoral head. In the CCS group, there were 2 cases of nonunion, 9 cases of avascular necrosis of the femoral head, and 11 cases of femoral neck shortening, among which 5 cases underwent total hip replacement due to nonunion and avascular necrosis of the femoral head. CONCLUSION With simple operation, rotational stability and angular stability, FNS enables patients to start functional exercise as early as possible and reduces the incidence of postoperative complications of unstable femoral neck fracture. It is a new choice for the treatment of unstable femoral neck fracture in young adults.

Objective: To observe the dynamic impacts of shock waves on the severity of lung injury in rats with different injury distances. Methods: Simulate open-field shock waves; detect the biomechanical effects of explosion sources at distances of 40, 44, and 48 cm from rats; and examine the changes in the gross anatomy of the lungs, lung wet/dry weight ratio, hemoglobin concentration, blood gas analysis, and pathology. Results: Biomechanical parameters such as the overpressure peak and impulse were gradually attenuated with an increase in the injury distance. The lung tissue hemorrhage, edema, oxygenation index, and pathology changed more significantly for the 40 cm group than for the 44 and 48 cm groups. The overpressure peak and impulse were significantly higher for the 40 cm group than for the 44 and 48 cm groups ( < 0.05 or < 0.01). The animal mortality was significantly higher for the 40 cm group than for the other two groups (41.2% . 17.8% and 10.0%, < 0.05). The healing time of injured lung tissues for the 40 cm group was longer than those for the 44 and 48 cm groups. Conclusions The effects of simulated open-field shock waves on the severity of lung injuries in rats were correlated with the injury distances, the peak overpressure, and the overpressure impulse.
Animals ; Biomechanical Phenomena ; Blast Injuries ; etiology ; pathology ; Disease Models, Animal ; Explosions ; Lung Injury ; etiology ; pathology ; Male ; Random Allocation ; Rats ; Rats, Sprague-Dawley