OBJECTIVE: To explore an optimal method of recombinant human epidermal growth factor(rhEGF) application on the burn wounds of superficial II degree and profound II degree for accelerating its healing. METHODS: There were 180 burn wounds in 60 patients with the self-corresponding wound of the same degree as controls. The wounds of all patients were divided three regions(A, B, C). The wounds were treated once a day with 1% SD-Ag in region A as controls, with rhEGF(40 U/cm2) in region B, and with a combination of rhEGF(40 U/cm2) and Su Yu Ping (5 g) in region C. The wound healing time was recorded and compared. RESULTS: In regions A, B and C, the healing time of superficial II degree wound was (13.20 +/- 2.40) days, (10.20 +/- 2.20) days and (8.72 +/- 2.31) days (P lt; 0.01); that of profound II degree wound was (20.10 +/- 3.40) days, (17.20 +/- 3.12) days and (15.10 +/- 3.81) days respectively (P lt; 0.01, P lt; 0.05). The healed wound of profound II degree was elastic and tough in regions B and C, while that was not elastic and tough, and congestive in region A. CONCLUSION: The above results indicate that rhEGF can enhance burn wound healing markedly and that a combination rhEGF and Su Yu Ping has more significant effect than rhEGF alone and is recommended for clinical application.
OBJECTIVE: To fabricate artificial human skin with the tissue engineering methods. METHODS: The artificial epidermis and dermis were fabricated based on the successful achievements of culturing human keratinocytes(Kc) and fibroblasts (Fb) as well as fabrication of collagen lattice. It included: 1. Culture of epidermal keratinocytes and dermal fibroblasts: Kc isolated from adult foreskin by digestion of trypsin-dispase. Followed by comparison from aspects of proliferation, differentiation of the Kc, overgrowth of Fb and cost-benefits. 2. Fabrication of extracellular matrix sponge: collagen was extracted from skin by limited pepsin digestion, purified with primary and step salt fraction, and identified by SDS-PAGE. The matrix lattice was fabricated by freeze-dryer and cross-linked with glutaraldehyde, in which the collagen appeared white, fibrous, connected and formed pores with average dimension of 180 to 260 microns. 3. Fabrication artificial human skin: The artificial skin was fabricated by plating subcultured Kc and Fb separately into the lattice with certain cell density, cultured for one week or so under culture medium, then changed to air-liquid interface, and cultured for intervals. RESULTS: The artificial skin was composed of dermis and epidermis under light microscope. Epidermis of the skin consisted of Kc at various proliferation and differentiation stages, which proliferated and differentiated into basal cell layer, prickle cell layer, granular layer, and cornified layer. Conifilament not only increased in number, but also gathered into bundles. Keratohyalin granules at different development stages increased and became typical. The kinetic process of biochemistry of the skin was coincide with the changes on morphology. CONCLUSION: Tissue engineered skin equivalent has potential prospects in application of repairing skin defect with advantages of safe, effective and practical alternatives.
This paper makes persuasive demonstrations on some problems about the human ear sound transmission principle in existing physiological textbooks and reference books, and puts forward the authors' view to make up for its literature. Exerting the knowledge of lever in physics and the acoustics theory, we come up with an equivalent simplified model of manubrium mallei which is to meet the requirements as the long arm of the lever. We also set up an equivalent simplified model of ossicular chain--a combination of levers of ossicular chain. We disassemble the model into two simple levers, and make full analysis and demonstration on them. Through the calculation and comparison of displacement amplitudes in both external auditory canal air and internal ear lymph, we may draw a conclusion that the key reason, which the sound displacement amplitude is to be decreased to adapt to the endurance limit of the basement membrane, is that the density and sound speed in lymph is much higher than those in the air.
Robot rehabilitation has been a primary therapy method for the urgent rehabilitation demands of paralyzed patients after a stroke. The parameters in rehabilitation training such as the range of the training, which should be adjustable according to each participant’s functional ability, are the key factors influencing the effectiveness of rehabilitation therapy. Therapists design rehabilitation projects based on the semiquantitative functional assessment scales and their experience. But these therapies based on therapists’ experience cannot be implemented in robot rehabilitation therapy. This paper modeled the global human-robot by Simulink in order to analyze the relationship between the parameters in robot rehabilitation therapy and the patients’ movement functional abilities. We compared the shoulder and elbow angles calculated by simulation with the angles recorded by motion capture system while the healthy subjects completed the simulated action. Results showed there was a remarkable correlation between the simulation data and the experiment data, which verified the validity of the human-robot global Simulink model. Besides, the relationship between the circle radius in the drawing tasks in robot rehabilitation training and the active movement degrees of shoulder as well as elbow was also matched by a linear, which also had a remarkable fitting coefficient. The matched linear can be a quantitative reference for the robot rehabilitation training parameters.
Objective To analyze the clinical data of monkeypox (mpox) cases in Chengdu, to investigate the clinical characteristics of patients with mpox complicated with human immunodeficiency virus (HIV) / acquired immunodeficiency syndrome (AIDS), and provide reference for clinical diagnosis and treatment. Methods Mpox patients admitted to Public Health Clinical Center of Chengdu between June 29 and August 8, 2023 were continuously included. Patients were divided into an observation group and a control group based on whether they were complicated with HIV/AIDS. The clinical characteristics of two groups of patients were observed and compared. Results A total of 56 patients were included, all of whom were male; Age range from 19 to 51 years old, with an average of (31.6±5.9) years old; There were 23 cases in the observation group and 33 cases in the control group. Except for age, perianal lesions with infection, number of rashes, diarrhea, CD4+ lymphocyte count, CD4/CD8 ratio, syphilis, chest CT abnormalities, rash duration, and length of hospital stay (P<0.05), there was no statistically significant difference in epidemiological data, clinical features, auxiliary examinations, treatment, and intensive care unit admission between the two groups of patients (P>0.05). There was a statistically significant difference between the Ct values of throat swab nucleic acid and blister fluid nucleic acid in the total population [(30.1±4.4) vs. (23.4±3.8); t=5.462, P<0.001]. Conclusions Mpox patients complicated with HIV/AIDS are prone to persistent, diverse, and severe lesions due to relatively lower CD4+ lymphocyte counts. Therefore, it is necessary to actively provide symptomatic treatment and prevent complications for patients.
OBJECTIVE: To investigate the efficiency of recombinant human epidermal growth factor (rhEGF) on burn wound healing and to explore the effective density of the ointments. METHODS: A total of 120 cases of burn in superficial II degree and profound II degree were randomly divided into 2 groups. In the first group of 15 cases of superficial II degree, the wounds were treated by rhEGF ointments of different density, 0.5 microgram/g, 10 micrograms/g and 50 micrograms/g, to screen out the effective density. And in the other 105 cases of the second group, optimal density of the ointments based on the result of the first group were employed to treat the burn wound in superficial II degree and profound II degree, with the self-corresponding wounds of the same degree as control, to study the efficiency of rhEGF on wound healing, according to the wound healing time, and adverse reaction of the ointment. RESULTS: In the first group, the average healing time of superficial II wound treated by ointments of 10 micrograms/g and 50 micrograms/g significantly shortened when compared with that treated by ointments of 0.5 microgram/g(P lt; 0.01), but there was no obvious difference between the cases treated by ointments of 10 micrograms/g and 50 micrograms/g. In the second group, the healing time of superficial II wound treated by ointments of 10 micrograms/g was (8.39 +/- 2.25) days, (9.52 +/- 2.56) days in the control (P lt; 0.01); and healing time of profound II burn treated by ointments of 10 micrograms/g was (16.80 +/- 2.99) days, (18.27 +/- 3.17) days in the control (P lt; 0.01). And healing rates of burn wound at different periods were higher than those of the control. CONCLUSION: The above results indicate that rhEGF ointments can enhance burn wound healing significantly, and the ointment of 10 micrograms/g is a good choice for clinical application.
ObjectiveTo investigate the aim antigen coursing the hyperacute rejection of xenotransplantation. MethodsDocuments about hyperacute rejection in xenotransplantation were reviewed and summarized in detail. ResultsPig is thought to be one of the ideal donors of xenotransplantation, but the major obstacle is hyperacute rejection mediated by complement that is activated though human serum. αGal is recognized as the major antigen and its expression is controlled by α1,3 galactosyltransferase. Immunoabsorption of preexsisted antibody, enzymatic digestion of αGal, knockout αGT gene and transgenic technology have been used to solve this problem. Even so, there remain other antigens which can combine with natural antibodies in human serum, such as, 40×103 molecule in erythrocyte, 210×103, 105×103 and 50×103 antigen in pig embryo brain cell, etc. Conclusion αGal is the major antigen which course the hyperacute rejection. Besides αGal, many nonalphagal need further investigation.
Objective To investigate a new grafting material of bone xenograft with b bone inductive and conductive capacity. Methods Based on successful clinical application of the reconstituted bone xenograft (RBX), a new xenograft was made by combining recombinant human bone morphogenetic protein-2 (rhBMP-2) with antigen-free bovine cancellous bone (BCB). Sixty male BALB/C mice aged 4 weeks were divided into study group of 30 and control group of 30 randomly. rhBMP-2 / BCB was implanted in the left thigh muscle pouch in the study group andBCB in the control group. The mice were sacrificed at 7 d, 14d and 21d after implantation. Inductivity of rhBMP-2/BCB was detected by histological observation and biochemical determination of the samples. Results Histological examinationshowed that rhBMP-2/BCB induced chondrogenesis on the 7th day, with woven boneformed on the 14th day, and lamellar bone and marrow on the 21st day, while BCBfailed to induce chondrogenesis or osteogenesis on the 7th, 14th and 21st days. The alkaline phosphatase activities and calcium content in study group were higher than those in control group with significant difference (P＜0.01). Conclusion rhBMP-2/BCB is an ideal grafting material with b bone inductive and conductive capacity without evoking immune reaction.
Primary human hepatocytes (PHH) are the gold standard of in vitro human liver model for drug screening. However, a problem of culturing PHH in vitro is the rapid decline of cytochrome P450 (CYP450) activity, which plays an important role in drug metabolism. In this study, thermo-responsive culture dishes were used to explore the conditions for murine embryonic 3T3-J2 fibroblasts to form cell sheet. Based on the cell sheet engineering technology, a three-dimensional (3D) “sandwich” co-culture system of 3T3-J2 cell sheet/PHH/collagen gel was constructed. The tissue structure and protein expression of the model section were observed by hematoxylin eosin staining and immunofluorescence staining respectively. Phenacetin and bupropion were used as substrates to determine the activity of CYP450. The contents of albumin and urea in the system were determined by enzyme linked immunosorbent assay (ELISA). The results showed that the complete 3T3-J2 cell sheet could be obtained when the cell seeding density was 1.5×106 /dish (35 mm dish) and the incubation time at low temperature was 60 min. Through cell sheet stacking, a 3D in vitro liver model was developed. Compared with the two-dimensional (2D) model, in the 3D model, the cell-cell and cell-matrix connections were tighter, the activities of cytochrome P450 CYP1A2 and cytochrome P450 CYP2B6 were significantly increased, and the secretion levels of albumin and urea were increased. These indexes could be maintained stably for 21 d. Therefore, cell sheet stacking is helpful to improve the level of liver function of 3D liver model. This model is expected to be used to predict the metabolism of low-clearance drugs in preclinical, which is of great significance for drug evaluation and other studies.
The aim of the study is to identify the effects and underlying mechanisms of visfatin on inflammation and necroptosis in vascular endothelial cells. Human umbilical vein endothelial cells (HUVECs) were stimulated with visfatin or pretreated with Polyinosinic acid (LOX-1 inhibitor). By using the Western blot, RT-PCR, immunocytochemistry, enzyme-linked immunosorbent assay (ELISA), MTT and flow cytometry technique, the occurrence of inflammation and necroptosis in HUVECs were evaluated. Our results showed that 100 ng/mL visfatin significantly increased the mRNA and protein expression of monocyte chemotactic protein 1 (MCP-1) and LOX-1 after 24 hours’ treatment in HUVECs. However, pretreatment with Polyinosinic acid could significantly reduce the expression of MCP-1 compared with visfatin group. Additionally, 100 ng/mL visfatin could induce the production of necrotic features and increase the mRNA expression of BMF (one of the markers of necroptosis), while pretreating with Polyinosinic acid markedly downregulated the mRNA expression of BMF gene and promoted the cell proliferation. These results indicate that visfatin might induce inflammation and necroptosis via LOX-1 in HUVECs, suggesting that visfatin plays a central role in the development of atherosclerosis.