BACKGROUND:Compared with traditional two-dimensional culture,three-dimensional microtissue culture can show greater advantages.However,more favorable cultivation methods in three-dimensional culture still need to be further explored. OBJECTIVE:To evaluate the cell behavior of microtissue and its ability to promote cartilage formation under two three-dimensional culture methods. METHODS:Cartilage-derived microcarriers were prepared by chemical decellularization and tissue crushing.DNA quantification and nuclear staining were used to verify the success of decellularization,and histological staining was used to observe the matrix retention before and after decellularization.The microcarriers were characterized by scanning electron microscopy and CCK-8 assay.Cartilage-derived microtissues were constructed by combining cartilage-derived microcarriers with human adipose mesenchymal stem cells through three-dimensional static culture and three-dimensional dynamic culture methods.The cell viability and chondrogenic ability of the two groups of microtissues were detected by scanning electron microscopy,live and dead staining,and RT-qPCR. RESULTS AND CONCLUSION:(1)Cartilage-derived microcarriers were successfully prepared.Compared with before decellularization,the DNA content significantly decreased after decellularization(P<0.001).Scanning electron microscope observation showed that the surface of the microcarrier was surrounded by collagen,maintaining the characteristics of the natural extracellular matrix of cartilage cells.CCK-8 assay indicated that microcarriers had no cytotoxicity and could promote cell proliferation.(2)Scanning electron microscopy and live and dead staining results showed that compared with the three-dimensional static group,the three-dimensional dynamic group had a more extended morphology of microtissue cells,and extensive connections between cells and cells,between cells and matrix,and between matrix.(3)The results of RT-qPCR showed that the expressions of SOX9,proteoglycan,and type Ⅱ collagen in microtissues of both groups were increased at 7 or 14 days.The relative expression levels of each gene in the three-dimensional dynamic group were significantly higher than those in the three-dimensional static group at 14 days(P<0.05).At 21 days,the three-dimensional static group had significantly higher gene expression compared with the three-diomensional dynamic group(P<0.001).(4)The results showed that compared with three-dimensional static culture microtissue,three-dimensional dynamic culture microtissue could achieve higher expression of chondrogen-related genes in a shorter time,showing better cell viability and chondrogenic ability.

Objective:To study the in vitro construction of functional and self-renewing cartilage organoids based on cartilage acellular extracellular matrix (ECM) microcarriers.Methods:Fresh porcine articular cartilage was taken. The merely crushed cartilage particles were set as natural cartilage group and ECM microcarriers of appropriate particle size, which were prepared by the acellular method of combining physical centrifugation and chemical extraction, were set as microcarrier group. Cartilage organoids were constructed by loading human umbilical cord mesenchymal stem cells (hUCMSCs) and human chondrocytes (hCho) with a ratio of 3∶1 with microcarriers through a rotating bioreactor. The organoids with different induction times were divided into 0-, 7-, 14-, and 21-day induction groups. The cell residues of the microcarrier group and natural cartilage group were evaluated by 4′, 6-diaminidine 2-phenylindole (DAPI) fluorescence staining and DNA quantitative analysis. The retention of microcarrier components was observed by Safranin O and toluidine blue stainnings, and the collagen and glycosaminoglycan (GAGs) levels in the microcarrier group and the natural cartilage group were determined by colorimetric method and dimethyl-methylene blue (DMMB) method. The microcarriers were further characterized by scanning electron microscopy and energy dispersive spectroscopy. The hUCMSCs cultured with Dulbecco′s Modified Eagle′s Medium (DMEM) supplemented with fetal bovine serum (FBS) in a volume fraction of 10% was used as the control group and the hUCMSCs cultured with the microcarrier extract was used as the experimental group. Subgroups of hUCMSCs cultured at 3 time points: 1, 3 and 5 days were set up in the two groups separately. Cell Counting Kit 8 (CCK-8) was used to detect the biocompatibility of the two groups. The cellular activity of the organoids of the 0-, 7-, 14-, and 21-day induction groups was detected by live/dead staining and the self-renewal ability of the cartilage organoids of the 14-day induced group was identified by Ki67 fluorescence staining. The organoids of the 7-, 14-, and 21-day induction groups were detected by RT-PCR in terms of the expression levels of chondrogenesis-related marker aggrecan (ACAN), type II collagen (COL2A1), SRY-related high mobility group-box gene-9 (SOX9), cartilage hypertrophy-and mineralization-related marker type I collagen (COL1A1), Runt-related transcription factor-2 (RUNX2), and osteocalcin (OCN). Colorimetric and DMMB assays were performed to determine the ability of organoids in the 0-, 7-, 14-, and 21-day induction groups to secrete collagen and GAGs.Results:The results of DAPI fluorescent staining showed that the natural cartilage group had a large number of nuclei while the microcarrier group hardly had any nuclei. The DNA content of the microcarrier group was (7.8±1.8)ng/mg, which was significantly lower than that of the natural cartilage group [(526.7±14.7)ng/mg] ( P<0.01). Saffranin O and toluidine blue staining showed that the microcarrier was dark- and uniform-colored and it kept a lot of cartilage ECM components. The collagen and GAGs contents of the microcarrier group were (252.9±1.4)μg/mg and (173.4±0.8)μg/mg, which were significantly lower than those of the natural cartilage group [(311.9±2.2)μg/mg and (241.3±0.7)μg/mg] ( P<0.01). Scanning electron microscopy showed that the surface of the microcarriers had uneven and interleaved collagen fiber network. The results of energy spectrum analysis showed that elements C, O and N were evenly distributed in the microcarriers, indicating that the composition of the microcarrier was uniform. The microcarrier had good biocompatibility and there was no statistical significance in the results of CCK-8 test between the control group and the experimental group after 1 and 3 days of culture ( P>0.05). After 5 days of culture, the A value of the experimental group was 0.53±0.02, which was better than that of the control group (0.44±0.03) ( P<0.05). In the 0-, 7-, 14-, and 21-day induction groups, hUCMSCs and hCho were attached to the surface of the microcarriers, with good cellular activity, and the live/death rates were (70.6±1.1)%, (80.5±0.6)%, (94.5±0.9)%, and (90.8±0.5)% respectively ( P<0.01). There were a large number of Ki67 positive cells in cartilage organoids. RT-PCR showed that the expression levels of ACAN, COL2A1, SOX9, COL1A1, RUNX2 and OCN were 1.00±0.09, 1.00±0.24, 1.00±0.18, 1.00±0.03, 1.00±0.06 and 1.00±0.13 respectively in the 7-day induction group; 4.16±0.28, 5.09±1.25, 5.65±1.05, 0.47±0.01, 1.68±0.02 and 0.21±0.06 respectively in the 14-day induction group; 13.42±0.92, 3.07±0.21, 1.84±1.08, 2.72±0.17, 2.91±0.18 and 3.32±1.20 respectively in the 21-day induction group. Compared with the 7-day induction group, the expression levels of ACAN, COL2A1, SOX9 and RUNX2 in the 14-day group were increased ( P<0.05), but COL1A1 expression level was decreased ( P<0.05), with no significant difference in OCN expression level ( P>0.05). Compared with the 7-day induction group, the expression levels of ACAN, COL1A1 and RUNX2 in the 21-day induction group were significantly increased ( P<0.01), with no significant differences in the expression levels of COL2A1, SOX9 and OCN ( P>0.05). Compared with the 14-day induction group, the expression levels of ACAN, COL1A1, RUNX2 and OCN in the 21-day group were increased ( P<0.05 or 0.01), with no significant difference in the expression level of COL2A1 ( P>0.05), but the expression level of SOX9 was decreased ( P<0.05). The contents of collagen in 0-, 7-, 14-and 21-day induction groups were (219.15±0.48)μg/mg, (264.07±1.58)μg/mg, (270.83±0.84)μg/mg and (280.01±0.48)μg/mg respectively. The GAGs contents were (171.18±1.09)μg/mg, (184.06±1.37)μg/mg, (241.08±0.84)μg/mg and (201.14±0.17)μg/mg respectively. Compared with the 0-day induction group, the contents of collagen and GAGs in 7-, 14-, and 21-day induction groups were significantly increased ( P<0.01), among which the content of collagen was the lowest in 7-day induction group ( P<0.01) but the highest in the 21-day induced group ( P<0.01); the content of GAGs was the lowest in the 7-day induced group ( P<0.01) but the highest in the 14-day induction group ( P<0.01). Conclusions:The microcarriers prepared by combining physical and chemical methods are decellularized successfully, with more matrix retention, uniform composition and on cytotoxicity. By loading microcarriers with hUCMSCs and hCho, cartilage organoids are successfully constructed in vitro, which are characterized by good cell activity, self-renewal ability, strong expression of genes related to chondrogenesis and secretion of collagen and GAGs. The cartilage organoids constructed at 14 days of induction have the best chondrogenic activity.

Osteoporosis is a systemic metabolic bone disease characterized by decreased bone mass, damage to bone tissue microstructure, increased bone fragility, and susceptibility to fractures, while sarcopenia is a syndrome characterized by progressive reduction in overall muscle mass and functional decline. Based on the common pathophysiological mechanism and close correlation between the two, the concept of "osteosarcopenia" has gradually emerged to describe the simultaneous attenuation of muscles and bones. Signaling pathways serve as important signal transmission channels between muscles and bones, and if abnormal, they can lead to osteosarcopenia. The aim of this article, therefore, is to review the signaling pathways related to osteogenesis and myogenesis, such as Hedgehog, Hippo, mTOR, MAPK, in order to provide new ideas for targeted treatment of osteosarcopenia.

Limb dismemberment injuries are common in clinical practice,and safe and effective protection of the dismembered limb is the key to successful limb replantation.Normothermic machine perfusion has made significant breakthrough in the field of organ transplantation,which may maintain the active function of organs and tissues for a long period of time and prolong the preservation time.These findings have been validated in large animal models and clinical trials.Meantime,this technology is expected to provide novel reference for the preservation and functional recovery of severed limbs.Therefore,this paper reviews the problems of static cold preservation in the preservation of disarticulated limbs,the development history of mechanical perfusion,the current status of clinical application of ambient mechanical perfusion of disarticulated limbs as well as the problems to be solved,and looks forward to the direction of its development and the prospect of its clinical application,with a view to promoting the wide application of this technology in the clinic.

Objective To investigate the influencing factors of Mismatch ratio in computed tomography perfusion(CTP)and dif-fusion weighted imaging(DWI)to assess the lesion outcome after treatment in patients with acute ischemic stroke(AIS).Methods Whether there were any differences in clinical and imaging data of AIS patients were analyzed retrospectively between the Mismatch ratio＞1.2 group and the Mismatch ratio≤1.2 group,and between the hemorrhagic transformation group and the non-hemorrhagic transformation group.Results The age of onset and National Institutes of Health Stroke Scale(NIHSS)score of AIS patients in the group with Mismatch ratio＞1.2 were greater than those in the group with Mismatch ratio≤1.2.The Mismatch ratio＞1.2 group had lower incidence of hyperlipidemia,new infarct foci,and higher hypercoagulability,cerebral hemorrhage,as well as large cerebral infarction.The NIHSS score was higher in the hemorrhagic transformation group than the non-hemorrhagic transformation group,and the incidence of large cerebral infarction and digital subtraction angiography(DSA)thrombectomy was higher in the former than in the latter.Multifactorial logistic analysis showed that age,NIHSS score,and hyperlipidemia were independent risk factors for AIS patients with Mismatch ratio＞1.2 and large cerebral infarction was an independent risk factor for hemorrhagic transformation.Conclusion The Mismatch ratio in CTP is correlated with age,NIHSS score,and hyperlipidemia in patients with AIS and large cerebral infarction is correlated with hemorrhagic transformation.

Nuclear receptor corepressor (NCoR1) interacts with various nuclear receptors and regulates the anabolism and catabolism of lipids. An imbalance in lipid/energy homeostasis is also an important factor in obesity and metabolic syndrome development. In this study, we found that the deletion of NCoR1 in intestinal epithelial cells (IECs) mainly activated the nuclear receptor PPARα and attenuated metabolic syndrome by stimulating thermogenesis. The increase in brown adipose tissue thermogenesis was mediated by gut-derived tricarboxylic acid cycle intermediate succinate, whose production was significantly enhanced by PPARα activation in the fed state. Additionally, NCoR1 deletion derepressed intestinal LXR, increased cholesterol excretion, and impaired duodenal lipid absorption by decreasing bile acid hydrophobicity, thereby reversing the possible negative effects of intestinal PPARα activation. Therefore, the simultaneous regulatory effect of intestinal NCoR1 on both lipid intake and energy expenditure strongly suggests that it is a promising target for developing metabolic syndrome treatment.

【Objective】 To analyze the basic characteristics of whole blood donors from blood stations before and after the outbreak of COVID-19. 【Methods】 After excluding invalid data, data related to the basic characteristics of whole blood donors collected from 26 blood stations in China during 2018 to 2021 were statistically analyzed, including the trend of total whole blood donors, the number of repeated blood donors, the frequency of blood donation, the average age of donors and the recruitment of first-time blood donors. 【Results】 Affected by the epidemic, 8 out of 14 indicators were with large variations, accounting for 57%. The overall growth rate of total whole blood donors during the epidemic was higher than before the epidemic (P<0.05).The number of repeated blood donors has shown an increased trend, with a higher number during the epidemic than before (P<0.05). The frequency of blood donation was lower during the epidemic than before(P<0.05).Average ages of blood donors and female blood donors fluctuated widely during the epidemic, both higher than those before the epidemic(P<0.05).The donation rate of first-time blood donors <25 years old and ≥25 years old varied widely and irregularly during the epidemic (both P<0.05). The percentage of first-time blood donors fluctuated irregularly during the epidemic, with overall percentage lower than that before the epidemic(P<0.05). 【Conclusion】 Whole blood donors from 26 blood stations increased after the outbreak of COVID-19, and some indicators in certain areas showed significant fluctuations during the epidemic.

BACKGROUND: Management of gastric leak after sleeve gastrectomy (SG) is challenging due to its unpredictable outcomes. We aimed to summarize the characteristics of SG leaks and analyze interventions and corresponding outcomes in a real-world setting. METHODS: To retrospectively review of 15,721 SG procedures from 2010 to 2020 based on a national registry. A cumulative sum analysis was used to identify a fitting curve of gastric leak rate. The Kaplan-Meier method and log-rank tests were performed to calculate and compare the probabilities of relevant outcomes. The logistic regression analysis was conducted to determine the predictors of acute leaks. RESULTS: A total of 78 cases of SG leaks were collected with an incidence of 0.5% (78/15,721) from this registry (6 patients who had the primary SG in non-participating centers). After accumulating 260 cases in a bariatric surgery center, the leak rate decreased to a stably low value of under 1.17%. The significant differences presented in sex, waist circumference, and the proportion of hypoproteinemia and type 2 diabetes at baseline between patients with SG leak and the whole registry population ( P = 0.005, = 0.026, <0.001, and = 0.001, respectively). Moreover, 83.1% (59/71) of the leakage was near the esophagogastric junction region. Leakage healed in 64 (88.9%, 64/72) patients. The median healing time of acute and non-acute leaks was 5.93 months and 8.12 months, respectively. Acute leak (38/72, 52.8%) was the predominant type with a cumulative reoperation rate >50%, whereas the cumulative healing probability in the patients who required surgical treatment was significantly lower than those requring non-surgical treatment ( P = 0.013). Precise dissection in the His angle area was independently associated with a lower acute leak rate, whereas preservation ≥2 cm distance from the His angle area was an independent risk factor. CONCLUSIONS Male sex, elevated waist circumference, hypoproteinaemia, and type 2 diabetes are risk factors of gastric leaks after SG. Optimizing surgical techniques, including precise dissection of His angle area and preservation of smaller gastric fundus, should be suggested to prevent acute leaks.
Humans ; Male ; Retrospective Studies ; Diabetes Mellitus, Type 2/complications* ; Obesity, Morbid ; Anastomotic Leak/epidemiology* ; Gastrectomy/methods* ; Reoperation/methods* ; Registries ; Laparoscopy/methods* ; Treatment Outcome

Objective:To evaluate the efficacy of implant surface culture in identification of pathogens for fracture device-related infection.Methods:A prospective study was conducted to include the eligible patients who were diagnosed with infection after fracture fixation and needed surgical removal of the implants according to treatment principles at Division of Orthopaedics and Traumatology, Department of Orthopaedics and Traumatology, Nanfang Hospital from November 2020 to January 2023. With informed consent, after rinsing with aseptic normal saline twice, their implants were gently covered with a thin layer of tryptone soy agar medium. Thereafter, the implants were incubated at 37 ℃ with 5% CO 2. Changes on the surface and in the surroundings of the implants were observed every day for consecutive 2 weeks to avoid drying up by supplementing the medium when necessary. Once pathogen colonies formed, samples were collected at 3 independent sites using sterile swabs for laboratory identification. Comparisons were made between the samples from implant surface culture and the intraoperative multisite samples from conventional culture. Results:Included were a total of 75 patients [56 males and 19 females with an age of (46.2±15.4) years]. The most common infection site was the tibia (37 cases), and the most common type of implants was plate and screw (59 cases). The positive rate of implant surface culture was significantly higher than that of conventional culture (86.7% vs. 52.0%, P<0.001). 80.5% (29/36) of the negative patients detected by the conventional culture obtained positive results by the implant surface culture; three of the positive patients detected by the conventional culture obtained negative results by the implant surface culture. The culture results were positive by both culture methods in 36 patients, and consistent by both culture methods in 35 patients, yielding a consistent rate of 97.2% (35/36). The time for implant surface culture was significantly shorter than that for conventional culture [1 (1, 2) d versus 3 (3, 4) d] ( P<0.001). Of the 65 positive patients by the implant surface culture, 59 were detected with monomicrobial infection, with Staphylococcus aureus on the top (29 cases). Conclusion:As the implant surface culture, a novel method, may be superior to the conventional culture in a significantly higher positive rate and a shorter culture time, it may be used as an effective adjunct to the conventional culture in identification of pathogens for fracture device-related infection.

Objective:To evaluate devascularized bone surface culture for identification of microorganisms for osteomyelitis.Methods:A prospective study was conducted to include the eligible patients who were diagnosed with osteomyelitis and treated at Division of Orthopaedics and Traumatology, Department of Orthopaedics and Traumatology, Nanfang Hospital from December 2021 to January 2023. Their infected bone tissues were collected for both bone sample culture (BSC) and general sample culture (GSC). For BSC, the devascularized bone fragments, harvested intraoperatively, were put flat on sterile culture plates with solidified agar, their surface was gently covered with cooled and molten tryptone soy agar, and then the plates with bone samples were incubated at 37 ℃ with 5% CO 2. Meanwhile, 5 suspected samples of infected bone tissue were randomly harvested by 5 independent instruments for laboratory GSC. The culture time, bacterial species, and bacterial positive rate were compared between the 2 culture methods. Results:Included were a total of 73 patients [59 males and 14 females with an age of 49.0(31.0, 58.5) years]. The culture time for BSC [1 (1, 1) d] was significantly shorter than that for GSC [3 (2, 3) d], and the total positive rate of BSC [78.1% (57/73)] was significantly higher than that of GSC [61.6% (45/73)] ( P<0.05). The bacterial species cultured by GSC were consistent with those cultured by BSC. Conclusion:In identification of microorganisms for osteomyelitis, since BSC may be quicker and lead to a higher positive rate of bacterial culture than GSC, it can be used as an optional choice besides GCS.