In this research, we use mouse embryonic fibroblasts as feeder layers. To eliminate the influence of serum and mouse embryonic stem cells (ESCs) conditioned medium (ESCCM) on self-renewal of sheep embryonic stem-like cells, knockout serum replacement (KSR) was used to replace serum, then supplanted with ESCCM for the isolation and cloning of sheep embryonic stem-like cells. We found when inner cell masses (ICMs) cultured in the control group with medium supplanted with fetal bovine serum (FBS), sheep ES-like cells could not survive for more than 3 passages. However, sheep embryonic stem-like cells could remain undifferentiated for 5 passages when cultured in the medium that FBS was substituted by KSR. The result indicates that KSR culture system was more suitable for the isolation and cloning of sheep embryonic stem-like cells compared to FBS culture system. Finally we applied medium with 15% KSR as basic medium supplanted with 40% ESCCM as a new culture system to isolate sheep embryonic stem-like cells, we found one embryonic stem-like cell line still maintained undifferentiating for 8 passages, which characterized with a normal and stable karyotype and high expression of alkaline phosphatase. These results suggest that it is suitable to culture sheep ICM in the new culture system with 15% KSR as basic medium and supplanted with 40% ESCCM, which indicated that mouse ES cells might secrete factors playing important roles in promoting sheep ES-like cells' self-renewal.
Animals ; Cell Culture Techniques ; methods ; Cell Proliferation ; Cell Separation ; methods ; Clone Cells ; Culture Media ; Embryonic Stem Cells ; cytology ; Mice ; Sheep

Objective:To explore the effects of early debridement and conservative eschar removal followed by wound coverage with acellular dermal matrix (ADM), i.e., early surgery, in the treatment of children with deep burns.Methods:This study was a retrospective cohort study. From January 2017 to December 2022, 278 deep burned hospitalized children aged 1-7 years who met the inclusion criteria were admitted to Central Hospital Affiliated to Shandong First Medical University. According to the differences in treatment processes, 134 children who underwent early surgery+routine dressing change were enrolled in eschar removal+dressing change group (77 males and 57 females, aged 1 (1, 2) years), and 144 children who underwent only routine dressing change were enrolled in dressing change alone group (90 males and 54 females, aged 1 (1, 2) years). Fifty-one children without full-thickness burns in eschar removal+dressing change group were enrolled in eschar removal+dressing change group 1 (26 males and 25 females, aged 1 (1, 2) years), and 57 cases of the 83 children with full-thickness burns who did not undergo autologous skin grafting at the same time of early surgery (namely early skin grafting) in eschar removal+dressing change group were included in eschar removal+dressing change group 2 (37 males and 20 females, aged 1 (1, 2) years). Seventy-six children without full-thickness burns in dressing change alone group were included in dressing change alone group 1 (51 males and 25 females, aged 1 (1, 3) years), and 68 children with full-thickness burns in dressing change alone group were included in dressing change alone group 2 (39 males and 29 females, aged 1 (1, 2) years). For deep partial-thickness burn wounds and small full-thickness burn wounds in eschar removal+dressing change group, the eschar removal was performed on the basis of retaining a thin layer of denatured dermis so as to preserve the healthy tissue of the wound base, and ADM was applied to all wounds externally after eschar removal. For larger full-thickness burn wounds in this group, especially those located in the functional part of joints, eschar removal to the plane layer of viable tissue and early autologous skin grafting was needed. When the superficial wounds of children healed or tended to heal, the residual wounds were evaluated, and elective autologous skin grafting was performed if it was difficult to heal within 14 days. The healing time, intervention healing time, times of operation/dressing change, and times of intervention operation/dressing change in children with deep partial-thickness burn wounds of children in eschar removal+dressing change group, dressing change alone group, eschar removal+dressing change group 1, and dressing change alone group 1 were recorded. At the last follow-up (follow-up period was set to 7-12 months), the modified Vancouver scar scale (mVSS) scores of the most severe area of scar hyperplasia of healed deep partial-thickness burn wounds of 54 children in eschar removal+dressing change group and 48 children in dressing change alone group were recorded. The healing time and times of operation/dressing change of all burn wounds of children in eschar removal+dressing change group and dressing change alone group, and the healing time and times of operation/dressing change of full-thickness burn wounds of children in eschar removal+dressing change group 2 and dressing change alone group 2 were recorded. The incidences of wound infection, sepsis, fever, and fever after 5 days of burns in children of eschar removal+dressing change group and dressing change alone group during wound healing.Results:Compared with those in dressing change alone group, the healing time and intervention healing time were significantly shortened, and the times of operation/dressing change and times of intervention operation/dressing change were significantly reduced in children with deep partial-thickness burn wounds in eschar removal+dressing change group (with Z values of -11.00, -11.33, -12.64, and -11.65, respectively, P<0.05). Compared with those in dressing change alone group 1, the healing time and intervention healing time were significantly shortened, and the times of operation/dressing change and times of intervention operation/dressing change were significantly reduced in children with deep partial-thickness burn wounds in eschar removal+dressing change group 1 (with Z values of 6.57, 6.46, 8.04, and 6.57, respectively, P<0.05). At the last follow-up, the mVSS score of the most severe scar hyperplasia area of healed deep partial-thickness burn wounds of 54 children in eschar removal+dressing change group was 4.00 (3.00,5.00), which was significantly lower than 6.50 (5.00,7.00) of 48 children in dressing change alone group ( Z =-4.67, P<0.05).Compared with those in dressing change alone group, the healing time was significantly shortened, and times of operation/dressing change was significantly reduced in all burn wounds in eschar removal+dressing change group (with Z values of -5.20 and -6.34, respectively, P<0.05). Compared with those in dressing change alone group 2, the healing time was significantly shortened, and times of operation/dressing change was significantly reduced in full-thickness burn wounds in eschar removal+dressing change group 2 (with Z values of -5.22 and -5.73, respectively, P<0.05). During wound healing, the probabilities of fever and fever after 5 days of burns in children of eschar removal+dressing change group were significantly lower than those in dressing change alone group (with χ2 values of 4.13 and 3.91, respectively, P<0.05); only 1 child in dressing change alone group developed sepsis, and there was no statistically significant difference in the wound infection rate of children in the two groups ( P>0.05). Conclusions:For children with deep burns, early surgery, and early skin grafting or elective autologous skin grafting as needed, have better short-term and long-term effects than those without early surgery.

OBJECTIVES: Perfluorooctanoic acid (PFOA) can cause lipid metabolism disorders in animal body and affect the lipolysis and synthesis of fatty acids. Peroxisome proliferators-activated receptor (PPAR) plays an extremely important role in this process. This study aims to explore the effects of PFOA on liver lipid metabolism disorders in Sprague Dewley (SD) rats and the expression of PPAR. METHODS: A total of 40 male SD rats were randomly divided into 4 groups (n=10 in each group): a control group (ddH₂O), a low-dose PFOA group [PFOA 1.25 mg/(kg·d)], a middle-dose PFOA group [PFOA 5.00 mg/(kg·d)], and a high-dose PFOA group [PFOA 20.00 mg/(kg·d)]. The rats were fed with normal diet, and PFOA exposure were performed by oral gavage for 14 days, and the rats were observed, weighted and recorded every day during the exposure. After the exposure, the blood was collected, and the livers were quickly stripped after the rats were killed. Part of the liver tissues were fixed in 4% paraformaldehyde for periodic acid-schiff (PAS) staining; the contents of HDLC, LDLC, TG, TC in serum and liver tissues, as well as the activities of their related enzymes were assayed; The expression levels of cyclic adenosine monophosphate-response element binding protein (Cbp), general control of amino acid synthesis 5-like 2 (Gcn5L2), peroxidation peroxisome proliferation factor activated receptor γ (PPAR), silent information regulator 1 (Sirt1) and human retinoid X receptor alpha 2 (Rxrα2) ) were detected by Western blotting. RESULTS: After 14 days of PFOA exposure, the PAS staining positive particles in the cytoplasm and nucleus of SD rats in the medium and high dose groups were significantly reduced compared with the control group. The serum levels of LDLC and TC in the low-dose and middle-dose groups were significantly reduced compared with the control group (all P<0.05), while the high-dose group showed an increasing tendency, without siginificant difference (P>0.05), there was no significant difference in HDLC and TG (both P>0.05). The activities of alkaline phosphatase (AKP) and alanine aminotransferase (ALT) were increased significantly (both P<0.05) compared with control group; the ratio of ALT/aspartate aminotransferase (AST) in the high-dose group was increased significantly (P<0.05), there was no significant difference in LDH and TG (both P>0.05); the HDLC content in the liver tissues in the high-dose group was significantly reduced, compared with the control group (P<0.05); the TC contents in the liver tissues in the low, medium and high-dose groups were significantly increased (all P<0.05), there was no significant difference in LDLC and TG (both P>0.05); the AKP activity in the livers in the medium and high-dose groups was significantly increased (both P<0.05), there was no siginificant difference in LDH, ALT, and the ratio of ALT/AST (all P>0.05); the protein expression levels of Ppar γ, Cbp and Rxrα2 in the liver in the high dose groups were significantly down-regulated compared with the control group (all P<0.05), while the protein expression levels of Sirt1 were significantly up-regulated (all P<0.05). CONCLUSIONS PFOA exposure can cause lipid metabolism disorder and glycogen reduction in SD rat livers, which may be related to the activation of Sirt1 and inhibition of Ppar γ expression, leading to affecting the normal metabolism of fatty acids and promoting glycolysis.
Animals ; Caprylates ; Fatty Acids/pharmacology* ; Fluorocarbons ; Lipid Metabolism ; Lipid Metabolism Disorders/metabolism* ; Liver/metabolism* ; Male ; PPAR gamma ; Rats ; Rats, Sprague-Dawley ; Sirtuin 1/metabolism*

Background Job burnout is an early mental health condition caused by job stress and contributes to many negative effects on work and life. Employees of research and development (R&D) enterprises are exposed to constant pressure from innovation, production speed and sales expansion, and they are prone to burnout symptoms if such factors are not under effective control. Objective To evaluate the current situation of job burnout among employees of R&D enterprises in Minhang District of Shanghai and explore its influencing factors. Methods During November to December 2021, a cross-sectional study was developed and a convenient sampling method was used to enroll employees from 7 R&D enterprises in Minhang District of Shanghai. On the basis of voluntary participation with informed consent, a survey was conducted by using a self-made questionnaire (collecting data about general demographic characteristics, occupational characteristics, behavior and lifestyle), the Chinese version of the Concise Occupational Stress Questionnaire, and the Chinese version of the Maslach Burnout Inventory-General Survey. Occupational stress and its dimensions (job demand, job control, and social support) were divided into high, medium, and low levels according to tertiles. The positive rate of job burnout was reported according to score categorization (<1.5 refers to no job burnout, ≥1.5 refers to job burnout, where ≥1.5 and <3.5 refer to mild and moderate job burnout, and ≥3.5 refers to severe job burnout). Potential influencing factors of job burnout were evaluated by using one-way ANOVA, chi-square test, forward stepwise regression, and non-conditional binary logistic regression (α=0.05, two-sided test). Results A total of 3153 subjects were enrolled and 3014 samples were included in the analysis, with a valid response rate of 95.6%. Among the included subjects, 888 (29.46%) reported no job burnout, 1775 (58.89%) reported mild to moderate job burnout, and 351 (11.64%) reported severe job burnout. The mean of total job burnout score was 2.17±1.12, and the dimentional mean scores were 2.78±1.61 for emotional exhaustion, 1.60±1.60 for cynicism, and 4.05±1.57 for diminished personal accomplishment. Varied categories of sex, age, marital status, working position, sleep status, job demand, job control, and social support groups of workers resulted in significant differences in job burnout score. Compared with the low job demand group, the positive rate of job burnout was elevated in the medium and high job demand groups; the risk of job burnout in the medium job demand group was 1.42 (95%CI: 1.04-1.94) times higher, and that in the high job demand group was 2.64 (95% CI : 2.17-3.22) times higher versus the low job demand group. The risk of job burnout in the medium job control group was 1.35 (95%CI: 1.06-1.72) times higher versus the low job control group. Compared with the low social support group, job burnout was less reported in the other groups, and the OR (95%CI) values of the medium and high social support groups were 0.41 (0.31-0.53) and 0.15 (0.12-0.19) respectively. Conclusion The rate of reporting positive job burnout in R&D enterprises is high, which deserves sufficient attention. Relieving work pressure, increasing job control and social support, and maintaining adequate sleep are helpful to reduce job burnout.