BACKGROUND:The imbalance between bone resorption and bone formation in microgravity environments leads to significant bone loss in astronauts.Current research indicates that bone loss under microgravity conditions is the result of the combined effects of various cells,tissues,and systems. OBJECTIVE:To review different biological effects of microgravity on various cells,tissues,or systems,and summarize the mechanisms by which microgravity leads to the development of osteoporosis. METHODS:Databases such as PubMed,Web of Science,and the Cochrane Database were searched for relevant literature from 2000 to 2023.The inclusion criteria were all articles related to tissue engineering studies and basic research on osteoporosis caused by microgravity.Ultimately,85 articles were included for review. RESULTS AND CONCLUSION:(1)In microgravity environment,bone marrow mesenchymal stem cells tend to differentiate more into adipocytes rather than osteoblasts,and hematopoietic stem cells in this environment are more inclined to differentiate into osteoclasts,reducing differentiation into the erythroid lineage.At the same time,microgravity inhibits the proliferation and differentiation of osteoblasts,promotes apoptosis of osteoblasts,alters cell morphology,and reduces the mineralization capacity of osteoblasts.Microgravity significantly increases the number and activity of osteoclasts.Microgravity also hinders the differentiation of osteoblasts into osteocytes and promotes the apoptosis of osteocytes.(2)In a microgravity environment,the body experiences changes such as skeletal muscle atrophy,microvascular remodeling,bone microcirculation disorders,and endocrine disruption.These changes lead to mechanical unloading in the bone microenvironment,insufficient blood perfusion,and calcium cycle disorders,which significantly impact the development of osteoporosis.(3)At present,the mechanism by which microgravity causes osteoporosis is relatively complex.A deeper study of these physiological mechanisms is crucial to ensuring the health of astronauts during long-term space missions,and provides a theoretical basis for the prevention and treatment of osteoporosis.

OBJECTIVE To study the effect of Runzao zhiyang capsule （RZZY） on gut microbiota and its metabolites short- chain fatty acids （SCFA） in eczema rats， in order to reveal the improvement effect and possible mechanism of RZZY on eczema. METHODS The rats were divided into normal group， model group， desloratadine group （1.5 mg/kg）， and RZZY low-dose and high-dose groups （0.6， 1.2 g/kg）. Except for the normal group， the eczema model was established in other groups by applying the 2，4-dinitrochlorobenzene solution to the hair removal area to sensitize it； they were given relevant drugs intragastrically， once a day， for consecutive 2 weeks. After medication， the skin thickness of rats was measured， and the eczema area and severity index （EASI） scoring and pathology scoring were performed； the structure of gut microbiota was analyzed by 16S rDNA sequencing. The contents of SCFA （including acetic acid， propionic acid， and butyric acid） in feces were determined by gas phase-mass spectrometry. The expressions of signal transduction and activator of transcription 3 （STAT3） in the colon and skin were detected. RESULTS RZZY significantly alleviated skin swelling and ulceration and reduced EASI， skin thickness and pathological score in eczema rats （P＜0.05）. RZZY significantly increased ACE， Sobs and Shannon indexes （P＜0.05） and promoted the microbiota of eczema rats to return to normal structure. RZZY increased the abundance of Firmicutes and Lachnospira， Lactobacillus and Alistipes， while decreased the abundance of Bacteroidetes and Bacteroides. RZZY significantly increased the contents of propionic acid and butyric acid in the feces of eczema rats （P＜0.05）， while significantly down-regulated the expressions of STAT3 protein in the colon and skin （P＜0.05）. C ONCLUSIONS RZZY can improve SCFA levels by regulating gut microbiota， thereby inhibiting STAT3 expression， playing an anti- inflammatory role， and improving skin inflammation in eczema rats.

Objective:To systematically assess the effectiveness and safety of acupuncture for spastic hemiplegia after ischemic stroke. Methods:Randomized controlled trials(RCTs)of acupuncture treatment for spastic hemiplegia after ischemic stroke meeting the inclusion criteria in Cochrane Library,Medline,Excerpta Medica Database(EMBASE),PubMed,China National Knowledge Infrastructure(CNKI),SinoMed,Chongqing VIP Database(VIP),and Wanfang Data Knowledge Service Platform(Wanfang)published from each database's inception to February 2023 were retrieved by computer.Two reviewers independently extracted data and evaluated the risk of bias using Cochrane's risk of bias tool.Review Manager 5.4 was used for data analysis.Continuous data were evaluated using mean difference(MD)with a 95%confidence interval(CI),and dichotomous data were analyzed using risk ratio(RR). Results:A total of 24 trials,including 1 970 participants,were included in the study.The meta-analysis of 7 trials showed that compared to the rehabilitation therapy,acupuncture therapy was more effective in improving the simplified Fugl-Meyer assessment score after 1-month treatments[MD=10.52,95%CI(7.81,13.23),P<0.001].The meta-analysis of 2 articles showed the same tendency after 6-month treatments[MD=19.18,95%CI(11.34,27.02),P<0.001],and the 6-month treatment course resulted in better outcomes than the 1-month course.The meta-analysis of 8 trials showed that acupuncture had a better improvement on the Barthel index score than rehabilitation therapy after 1-month treatments[MD=10.78,95%CI(8.91,12.64),P<0.001].The meta-analysis of 2 articles showed the same tendency after 6-month treatments[MD=19.94,95%CI(19.02,20.87),P<0.001],and the 6-month course was better than the 1-month course.The meta-analysis of 2 trials showed that the effective rate of the modified Ashworth scale score improvement was more notable in the acupuncture group after 1-month treatments[RR=1.20,95%CI(1.02,1.40),P=0.020].One trial reported no adverse event,and 1 trial reported 3 adverse events without severe influence. Conclusion:Acupuncture might be an effective and safe therapy for spastic hemiplegia after ischemic stroke,but more high-quality,large-sample objectively-evaluated RCTs are needed to validate the conclusion.

Objective To evaluate the modified Aldrete scoring system(MASS)and the White's fast-track scoring system(WFTSS)in the context of enhanced recovery after surgery(ERAS)and to compare the effects of sevoflurane anesthesia maintenance with propofol intravenous anesthesia maintenance in the ERAS of patients undergoing laparoscopic cholecystectomy;to evaluate the MASS and WFTSS in the context of ERAS.Methods A total of 160 patients undergoing laparoscopic cholecystectomy from January 2021 to October 2023 in the First Affiliated Hospital of Ningbo University were randomly divided into sevoflurane group and propofol group,80 cases in each group.The sevoflurane group maintained on sevoflurane-remifentanil and propofol group on propofol-remifentanil.Patients ERAS were evaluated by WFTSS and MASS.Time to the recovery from anesthesia,number of patients meeting the ERAS,factors associated with non-ERAS compliance,and perioperative complications were recorded.Results The proportion of patients entering ERAS in both groups was higher in the MASS than in the WFTSS(P=0.031).In terms of extubation time,the sevoflurane group was significantly slower than propofol group(P=0.030).In terms of meeting ERAS criteria,the propofol group had significantly more patients than sevoflurane group(P=0.026),and the number of patients entering the recovery room was significantly less than in sevoflurane group(P=0.025).Regarding the factors affecting entry into ERAS,the number of cases in sevoflurane group was higher than in propofol group,with postoperative nausea being the only factor with statistical significance while others were not significantly different.Conclusion WFTSS provides a more comprehensive and effective assessment for ERAS at the time of leaving the operating room and can be considered as one of the discharge criteria for ERAS.It also concludes that compared with sevoflurane combined with remifentanil for anesthesia maintenance,the propofol combined with remifentanil maintenance can achieve the extubation requirements in the operating room more quickly and with fewer side effects.

Objective:To investigate the clinical effect of "ladder reduction method" in the treatment of iliac fracture combined anterior dislocation of sacroiliac joint.Methods:The retrospective analysis was performed on 10 cases of iliac fracture combined anterior sacroiliac joint dislocation admitted to the Affiliated Hospital of Yunnan University from February 2010 to January 2022, among which 5 cases were males and 5 cases were females, aged ranging from 22 to 52 years, with an average age of 38.8 years. All patients were injured in car accidents including 5 cases of C1.2, 3 cases of C2, and 2 cases of C3 fractures according to Tile classification. All patients were treated with the "ladder reduction method" with plate and screw fixation. In the first step, 1-2 Schanz pins were inserted into the iliac crest to control the ilium, and the Schanz pins were appropriately pulled laterally; in the second step, the periosteal stripper was used to pry the reduction between the sacrum and ilium; in the third step, for the patients who still could not be reduced, a 2.5 mm diameter Kirschner wire was placed on the sacrum close to the iliac crest, and a periosteal stripper was inserted between the sacrum and iliac crest, with its tip against the Kirkner wire, and the iliac crest as the fulcrum for pry pulling to separate the two. In the fourth step, the pry was maintained, and then another 2.5 mm diameter Kirschner wire was placed on the sacrum close to the internal margin of the iliac bone. The periosteal stripper was continued to pry between the sacrum and the iliac bone, and the operation was repeated. At the same time, the anterior dislocation of the sacroiliac joint was reduced with traction of the lower limb. Postoperatively, the quality of reduction was evaluated by the Matta score, and the degree of functional recovery after pelvic fracture was evaluated by the Majeed score.Results:Four patients completed the reduction through the first and second steps, and 6 cases of refractory sacroiliac joint anterior dislocation were successfully reduced through the first to fourth steps. The fracture reduction time of 6 patients with refractory anterior sacroiliac joint dislocation was 39.67±3.09 min (range, 35-44 min), with intraoperative blood loss of 300.00±141.42 ml (range, 150-600 ml); in the other 4 cases, the fracture reduction time was 36.75±4.38 min (range, 30-42 min), and the intraoperative blood loss was 225.00±44.30 ml (range, 200-300 ml). All 10 patients were followed up for 12.9±3.7 months (range, 9-20 months). The anterior and posterior pelvic ring fractures were healed in all patients, and the fracture healing time was 12.77±1.62 weeks (range, 10.71-15.28 weeks). At the last follow-up, Matta evaluation was excellent in 5 cases, good in 1 case, and excellent in the other 4 cases. The Majeed scores of 6 cases were 86.50±6.08 points (range, 74-92 points), of which 5 cases were excellent and 1 case was good. The other 4 cases were 81.5±9.39 scores (range, 71-94), of which 2 were excellent and 2 were good.Conclusion:The "ladder reduction method" is a safe, effective and easy-to-operate method for the treatment of iliac fracture combined anterior dislocation of the sacroiliac joint, especially for refractory anterior dislocation of the sacroiliac joint, which can still obtain satisfactory curative effects.

Objective:To investigate the effects of different connection schemes of continuous renal replacement therapy (CRRT) and extracorporeal membrane oxygenation (ECMO) on arterial pressure (PA), venous pressure (PV), and transmembrane pressure (TMP), and to provide a theoretical basis for choosing a suitable connection scheme.Methods:① In vitro study: the different connection schemes of CRRT and ECMO were simulated and divided into 6 schemes according to the connection between CRRT and ECMO circuits at different positions. Scheme A: connected to the front and back points of the oxygenator; scheme B: connected to the points behind and in front of the oxygenator; scheme C: connected to the points in front of the oxygenator and in front of the centrifugal pump; scheme D: connected to the points behind the oxygenator and in front of the centrifugal pump; scheme E: connected to the points in front of the oxygenator and the return catheter; scheme F: connected to the points after the oxygenator and the return catheter. Each set of ECMO circuits was measured 5 times under each connection scheme and different flow rates (2, 3, 4, 5, 5.5 L/min). Six ECMO circuits for a total of 30 measurements, and the PA, PV, and TMP of the 6 schemes were compared. ② In vivo study: the patients who were treated with ECMO combined with CRRT in the department of critical care medicine of the First Affiliated Hospital of Wannan Medical College from August 2017 to August 2021 changed the connection scheme due to high PA or PV (from scheme A or B to scheme E or F) were retrospectively analyzed. The changes of PA and PV before and after changing the scheme were compared. Results:① In vitro study results: there was no significant difference in PA between schemes A and B, C and D, E and F under different ECMO blood flow (2-5.5 L/min). The PA of schemes C and D was the lowest, followed by schemes E and F. PV of scheme B was higher than that of scheme A under different ECMO blood flow (2-5.5 L/min). There was no significant difference in PV between schemes C and D, E and F under high ECMO blood flow (3-5.5 L/min), and the absolute value of PV was lowest in schemes E and F. Compared with schemes A and B [partial PA > 300 mmHg (1 mmHg≈0.133 kPa) at high flow rate], C and D (partial PV > 350 mmHg at high flow rate), schemes E and F were more reasonable connection schemes. TMP was negative in schemes C and D at ECMO blood flow of 5 L/min and 5.5 L/min (mmHg; 5 L/min: scheme C was -29.14±11.42, scheme D was -42.45±15.70; 5.5 L/min: scheme C was -35.75±13.21, scheme D was -41.58±15.42), which indicated the presence of dialysate reverse filtration. Most of the differences in TMP among schemes A, B, E, and F under different ECMO blood flow (2-5.5 L/min) were statistically significant, and the absolute value of mean fluctuation was 9.89-49.55 mmHg, all within the normal range. ② In vivo study results: a total of 10 patients who changed the connection scheme (from scheme A or B to E or F) due to high PA or PV were enrolled, including 8 males and 2 females; 7 cases of venous-arterial ECMO (VA-ECMO) and 3 cases of venous-venous ECMO (VV-ECMO), all used continuous veno-venous hemodiafiltration (CVVHDF) mode. After changing the scheme, both PA and PV decreased significantly as compared with those before changing [PA (mmHg): 244.00±22.58 vs. 257.20±21.92, PV (mmHg): 257.20±18.43 vs. 326.40±15.41, both P < 0.01], and PV decreased more significantly than PA [difference (mmHg): 69.20±6.55 vs. 13.20±5.45, P < 0.01]. Conclusion:For patients treated with ECMO in combination with CRRT, the scheme of connecting the access line of CRRT to the pre-oxygenator or post-oxygenator and connecting the return line to the point of the return catheter can significantly reduce PA and PV and maintains normal CRRT operation even running high-flow ECMO.

Objective:To investigate the effectiveness of postoperative radiotherapy using shrinking field for patients with extremity soft tissue sarcoma (STS), mainly focusing on the local control rate and adverse events.Methods:Clinical data of 49 extremity STS patients who received postoperative intensity-modulated radiotherapy in the First Hospital of Tsinghua University from October 2017 to March 2021 were retrospectively analyzed. Target volumes were contoured on CT and MRI fusion images. The tumor bed was defined as GTV tb, with 3 cm expansion in the longitudinal direction and 1.5 cm expansion in the radial direction to construct CTV (the target volume should be properly repaired according to the anatomical barrier, and the edema area around the tumor should be included). GTV tb and CTV were expanded in all directions by 0.5 cm to construct PTV1 and PTV2 respectively, at a dose of 95%PTV1 63-66 Gy, 95%PTV2 50-56 Gy,1.8-2.0 Gy/f. The dose of surgical volume should be given at 70 Gy for patients who had a microscopic positive margin. Results:The median follow-up time was 32.1 months (7.9-45.6 months). The 3-year local failure-free survival (LFFS), overall survival (OS)and distant metastasis-free survival (DMFS) were 91.7%,77.6% and 71.5%, respectively. Univariate analysis showed that patients with a microscopic positive margin were more likely to develop local recurrence ( P<0.05). The incidence of grade 2 or above wound complications, joint stiffness, fracture, edema and skin fibrosis were 2%, 4.1%, 2%, 8.2% and 26.5%, respectively. Conclusion:Postoperative radiotherapy with shrinking field provides excellent local control rate and low incidence of late adverse events in patients with extremity STS.

Objective:To evaluate the role of mitophagy in cognitive dysfunction in rats with sepsis-associated encephalopathy (SAE).Methods:Twenty-four clean-grade healthy male Sprague-Dawley rats, aged 13-14 weeks, weighing 230-250 g, were divided into 3 groups ( n=8 each) using a random number table method: sham operation group (Sham group), SAE group and SAE+ autophagy inhibitor 3-methyladenine (3-MA) group (3-MA group).The SAE models were developed by cecal ligation and puncture in anesthetized animals.3-MA 10 mg/kg was intraperitoneally injected at 30 min after developing the model in 3-MA group.Cognitive function was assessed by Morris water maze test, and the escape latency and ratio of the time of staying at the target quadrant were recorded.After the end of Morris water maze test, the rats were sacrificed and hippocampal tissues were collected for microscopic examination of the pathological changes which were scored after hematoxylin-eosin staining and for determination of the expression of autophagy-related proteins LC3, Beclin1 and p62 (by Western blot).The ratio of LC3Ⅱ/LC3Ⅰwas calculated.The hippocampal mitochondria were isolated to measure mitochondrial membrane potential (MMP), ATP content and ATPase activity by spectrophotometry. Results:Compared with Sham group, the escape latency was significantly prolonged, the ratio of the time of staying at the target quadrant was decreased, the pathological score of hippocampus was decreased, and the contents of MMP and ATP and ATPase activity were decreased in SAE and 3-MA groups, the ratio of LC3Ⅱ/LC3Ⅰwas significantly increased, the expression of Beclin1 was up-regulated, and the expression of p62 was down-regulated in SAE group, and the ratio of LC3Ⅱ/LC3Ⅰwas significantly decreased, and the expression of Beclin1 and p62 was up-regulated in 3-MA group ( P<0.05).Compared with SAE group, the escape latency was significantly prolonged, the ratio of the time of staying at the target quadrant was decreased, the pathological score of hippocampus was decreased, the ratio of LC3/LC3Ⅰwas decreased, the expression of Beclin1 was down-regulated, the expression of p62 was up-regulated, and the contents of MMP and ATP and ATPase activity were decreased in 3-MA group ( P<0.05). Conclusions:Hippocampal mitophagy is involved in cognitive dysfunction in the rats with SAE.

Objective:To evaluate the role of p38 mitogen-activated protein kinase (MAPK)/cyclic adenosine monophosphate response element-binding protein (CREB) signaling pathway in tetramethylpyrazine-induced reduction of hippocampal inflammatory responses in mice with sepsis-associated encephalopathy (SAE).Methods:Sixty healthy male C57BL6 mice, weighing 24-27 g, were divided into 4 groups ( n=15 each) using a random number table method: sham operation group (group Sham), sepsis group (group Sep), tetramethylpyrazine group (group TMP) and p38 MAPK inhibitor SB203580 group (group SB). The model of SAE was established by cecal ligation and puncture in anesthetized mice.Tetramethylpyrazine 10 mg/kg was injected intraperitoneally once a day at 3 days before the establishment of the model in TMP group, and SB203580 2.0 mg/kg was intraperitoneally injected at 30 min after the establishment of the model in SB group.The equal volume of normal saline was given intraperitoneally in Sham and Sep groups.At 1 day after operation, cognitive function was assessed by Morris water maze, and the escape latency and ratio of time spent in the target quadrant were recorded.The animals were sacrificed after the test, and hippocampal tissues were taken for determination of the contents of interleukin-1beta (IL-1β), tumor necrosis factor-alpha (TNF-α) and IL-6 (by enzyme-linked immunosorbent assay) and for detection of the expression of phosphorylation of p38 MAPK, GSK3 and CREB and expression of brain-derived neurotrophic factor (BDNF) (by Western blot). Results:Compared with group Sham, the escape latency was significantly prolonged, the ratios of time spent in the target quadrant were decreased, the contents of IL-1β, TNF-α and IL-6 were increased, the phosphorylation of hippocampus p38 MAPK was increased, the phosphorylation of GSK3 and CREB were decreased, and the expression of BDNF was down-regulated in Sep, TMP and SB groups ( P<0.05). Compared with group Sep, the escape latency was significantly shortened, the ratios of time spent in the target quadrant were increased, the contents of IL-1β, TNF-α and IL-6 were decreased, the phosphorylation of hippocampus p38 MAPK was decreased, the phosphorylation of GSK3 and CREB were increased, and the expression of BDNF was up-regulated in TMP and SB groups ( P<0.05). Compared with group TMP, no significant change was found in the parameters mentioned above in group SB ( P>0.05). Conclusion:p38 MAPK/CREB signaling pathway is involved in the process of tetramethylpyrazine-induced reduction of hippocampal inflammatory responses in mice with SAE.

Objective:To evaluate the effect of tetramethylpyrazine on hippocampal inflammatory responses in rats with sepsis-associated encephalopathy.Methods:Sixty healthy male Sprague-Dawley rats, aged 12-14 weeks, weighing 240-270 g, were divided into 4 groups ( n=15 each) using a random number table method: sham operation group (group Sham), sepsis-associated encephalopathy group (group SAE), low-dose tetramethylpyrazine group (group L-TMP), and high-dose tetramethylpyrazine group (group H-TMP). Sepsis-associated encephalopathy was induced by cecal ligation and puncture (CLP) in anesthetized rats.Tetramethylpyrazine 5 and 20 mg/kg were intraperitoneally injected once a day in L-TMP and H-TMP groups, respectively, at 5 days prior to CLP.Morris water maze test was performed at 1-5 days after CLP to assess the cognitive function, and the escape latency and ratio of time spent in the target quadrant were recorded.Five rats were sacrificed at 1 day after CLP, the brains were removed, and the hippocampi were isolated for determination of the contents of interleukin-1beta (IL-1β), tumor necrosis factor-alpha (TNF-α) and IL-6 by enzyme-linked immunosorbent assay.Rats were sacrificed after the end of Morris water maze test, and hippocampi were removed for detection of the expression of Toll-like receptor 1 (TLR1), activated caspase-3, Bax and Bcl-2 by using Western blot. Results:Compared with group Sham, the escape latency was significantly prolonged, the ratios of time spent in the target quadrant were decreased, the expression of TLR1, activated caspase-3 and Bax was up-regulated, and the expression of Bcl-2 was down-regulated in group SAE, group L-TMP and group H-TMP, and the contents of IL-1β, TNF-α and IL-6 were significantly increased in group SAE and group L-TMP ( P<0.05). Compared with group SAE, the escape latency was significantly shortened, the ratio of time spent in the target quadrant was increased, the contents of IL-1β, TNF-α and IL-6 were decreased, the expression of TLR1, activated caspase-3 and Bax was down-regulated, and the expression of Bcl-2 was up-regulated in group L-TMP and group H-TMP ( P<0.05). Conclusion:The mechanism by which tetramethylpyrazine reduces sepsis-associated encephalopathy may be related to inhibiting hippocampal inflammatory responses in rats.