BACKGROUND: A novel photocrosslinked fish collagen peptide-hyaluronic acid hydrogel has been successfully prepared by the research group. OBJECTIVE: To investigate the microstructure and the swelling properties in vitro of the photocrosslinked fish collagen peptide-hyaluronic acid hydrogel, and its histocompatibility and degradability in vivo. METHODS: A new photocrosslinked fish collagen peptide-hyaluronic acid hydrogel was prepared by photocrosslinking, and then divided into groups A (30 g/L), B (50 g/L) and C (100 g/L) according to the content of fish collagen peptide. The microstructure of the hydrogel was observed by scanning electron microscope and the swelling properties of hydrogels were studied by swelling test in vitro. Fifteen male Sprague-Dawley rats (provided by Qingdao Qinda Breeding Co., Ltd.) were selected, and three kinds of photocrosslinked fish collagen peptide-hyaluronic acid hydrogels were implanted into the back of rats. At 1, 2, 4, 6 and 8 weeks after surgery, three rats were selected for detecting the histocompatibility and biodegradability of hydrogels. The study was approved by the Ethics Committee of School of Basic Medicine, Qingdao University. RESULTS AND CONCLUSION: (1) With the increase of fish collagen peptide content, the transparency of hydrogel decreased and the pore size of hydrogel decreased. (2) Swelling equilibrium was achieved within 100 minutes in each group, and the swelling velocity and equilibrium swelling rate were inversely proportional to the content of collagen peptide. The equilibrium swelling rate was highest in the group A, which was 1 582%. (3) The hydrogel had good histocompatibility, mild inflammatory reaction, no infection, hematoma or other complications in vivo. (4) At 1 week after implantation, inflammatory cell infiltration was observed surrounding the hydrogels. The level of inflammatory cells peaked at 2 weeks, and then decreased gradually. The count of inflammatory cells was highest in the group A, followed by group B, and lowest in the group C (P < 0.05). (5) After implanted into the back of rats, three kinds of hydrogels began to degrade, and residue still existed up to 8 weeks. The order of degradation rate at each time point was as follows: group A > group B > group C (P < 0.05). (6) These results indicate that photocrosslinked fish collagen peptide-hyaluronic acid hydrogel has good histocompatibility and biodegradability in vivo, which can be adjusted by the content of fish collagen peptides.

Objective:To compare and analyze the differences in the measurement of intra-abdominal pressure in different positions of critically ill patients treated with extracorporeal membrane oxygenation (ECMO) combined with prone position integration, with a view to finding a more optimal intra-abdominal pressure monitoring strategy, which can provide a theoretical basis for clinical diagnosis and treatment.Methods:Forty critically ill patients who underwent ECMO combined with prone position integrated treatment in the department of Intensive Care Medicine of the First Affiliated Hospital of Guangxi Medical University from January 2020 to June 2023 were selected by convenience sampling method using an own-control trial. The differences in intra-abdominal pressure between supine position with head elevated at 0°, 15°and 30°and prone position with head high and foot low slopes at 0°, 15°and 30°were compared and analyzed. Heart rate, respiration, mean arterial pressure and oxygen saturation were also compared in patients in different positions.Results:There were 29 males and 11 females in 40 patients with the age of (62.58 ± 17.99) years.The intra-abdominal pressure in supine position with head elevated at 30° was (12.45 ± 3.43) mmHg(1 mmHg=0.133 kPa), which was higher than that of 0° and 15° of (9.38 ± 2.52) and (10.70 ± 2.95) mmHg, and the differences were statistically significant ( t=4.56, 2.45, both P<0.05);the difference in intra-abdominal pressure between 0° and 15° was not statistically significant ( P>0.05); the intra-abdominal pressure in prone position with head-high-foot-low slope of 30° was (12.92 ± 4.19) mmHg, which was higher than that of 0°and 15°of (9.67 ± 2.80), and (11.01 ± 3.10) mmHg, and the differences were statistically significant ( t=4.08, 2.32, both P<0.05); the difference in intra-abdominal pressure between 0° and 15° was not statistically significant ( P>0.05).The differences in intra-abdominal pressure between groups of supine bed head elevation 0°, 15°, 30°and prone position with head high and foot low slopes 0°, 15°, 30°were not statistically significant (all P>0.05). The differences in heart rate, respiration, mean arterial pressure and oxygen saturation in the supine position with head elevated at 0°, 15°and 30° were not statistically significant when compared within groups (all P>0.05); the differences in heart rate, respiration, mean arterial pressure and oxygen saturation in the prone position with head elevated with feet and feet on low slopes at 0°, 15°and 30°were not statistically significant when compared within groups (all P>0.05); and the differences in supine position with head elevated at 0°, 15°, 30°and prone head-height-foot-low slope 0°, 15°, 30°of heart rate, respiration, mean arterial pressure were not statistically significant (all P>0.05); supine bed head elevation 0°, 15°, 30°and prone head-height-foot-low slope 0°, 15°, 30°of oxygen saturation between the groups, the differences were statistically significant ( Z=6.85, 6.82, 6.68, all P<0.05). Conclusions:Intra-abdominal pressure can be measured in the 15° prone position in critically ill patients treated with ECMO combined with prone position integration; the different positions have little effect on vital signs, but the prone position significantly improves oxygen saturation.

Objective To investigate the role and regulatory mechanism of stress-inducing protein 1(SESN1)in liver gluconeogenesis of fasting mice.Methods RT-qPCR was used to detect mRNA expression of SESN1 in liver tissues of C57BL/6J mice and primary mouse hepatocytes treated with forskolin(Fsk)and dexamethasone(Dex).HepG2 cells were transfected with plasmids and the effects of SESN1 overexpression on mRNA expression of gluconeogenesis related genes PGC-1α,PEPCK and G6Pase was detected by RT-qPCR.The effect of SESN1 on the promoter activity of PGC-1α in HepG2 cells was studied using a dual luciferase reporter system.The effect of SESN1 on PGC-1α deacetylation was detected by overexpression of SESN1 and inhibition of SIRT1 expression.By knocking down SIRT1 expression,we detected whether it mediated the changes in mRNA levels of SESN1 in-duced gluconeogenesis related genes.Results The mRNA expression of SESN1 was significantly increased in liver tissues of starved C57BL/6J mice and in primary hepatocytes treated with Fsk and Dex(P<0.001).Over-expression of SESN1 in HepG2 cells promoted mRNA expression of PGC-1α,PEPCK and G6Pase(P<0.001)and promoter activity of PGC-1α(P<0.001).Over-expression of SESN1 decreased the acetylation level of PGC-1α in primary hepatocytes.Sirt family inhibitors NAM and shRNA adenovirus interfered with SIRT1 expression respective-ly,and antagonized the deacetylation effect of SESN1 on PGC-1α.The expression of PGC-1α,PEPCK and G6Pase induced by SIRT1 was also significantly impaired(P<0.000 1).Conclusions SESN1 regulates liver gluconeogene-sis in mice with a SIRT1-dependent mechanism.

Objective To investigate the effect of Nutlin-3a,a mouse double minute 2 homolog(MDM2)inhibitor,on lipid metabolism of mouse adipose.Methods High-fat diet-induced obesity(DIO)C57BL/6J mice were randomly divided into a control group injected with DMSO and an experimental group injected with Nutlin-3a.Then we conducted glucose tolerance(GTT)and insulin tolerance(ITT)tests.The epididymal white adipose tissue(eWAT),inguinal white adipose tissue(iWAT)and brown adipose tissue(BAT)of animals were isolated and microscopy of WATs with hematoxylin-eosin(HE)staining was performed to observe the morphological changes of adipocytes.The expression of lipid metabolism related gene cell death-inducing DFF45-like effector C(CIDEC)in eWAT were detected by qPCR and Western blot.Results Compared with the control group,Nutlin-3a was found to promote the body weight(P＜0.001),but no effect on glucose tolerance and insulin sensitivity in DIO mice.Nutlin-3a treatment decreased the size of adipocytes and fat deposition in adipose tissue and downregulated the mRNA and protein levels of CIDEC in eWAT.Conclusions Nutlin-3a inhibits the formation of lipid droplets by downregulating expression of CIDEC in white adipose tissue.