Acute lung injury (ALI) has been a kind of acute and severe disease that is mainly characterized by systemic uncontrolled inflammatory response to the production of huge amounts of reactive oxygen species (ROS) in the lung tissue. Given the critical role of ROS in ALI, a Fe₃O₄ loaded bovine serum albumin (BSA) nanocluster (BF) was developed to act as a nanomedicine for the treatment of ALI. Combining with NIR irradiation, it exhibited excellent ROS scavenging capacity. Significantly, it also displayed the excellent antioxidant and anti-inflammatory functions for lipopolysaccharides (LPS) induced macrophages (RAW264.7), and Sprague Dawley rats via lowering intracellular ROS levels, reducing inflammatory factors expression levels, inducing macrophage M2 polarization, inhibiting NF-κB signaling pathway, increasing CD4⁺/CD8⁺ T cell ratios, as well as upregulating HSP70 and CD31 expression levels to reprogram redox homeostasis, reduce systemic inflammation, activate immunoregulation, and accelerate lung tissue repair, finally achieving the synergistic enhancement of ALI immunotherapy. It finally provides an effective therapeutic strategy of BF + NIR for the management of inflammation related diseases.

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 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.

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 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.

Objective:To analyze the hepatitis B vaccine (HepB) vaccination rate and immune level among children aged eight months to 14 years in Dali Bai Autonomous Prefecture, and to evaluate the effect of immune prevention and control.Methods:A stratified and cluster sampling was designed to survey and collect serum samples of the 17 236 cases from 12 counties (cities) in Dali Bai Autonomous Prefecture. The cases were divided into four age groups (eight to 17 months, 18 to 35 months, three to six years, seven to 14 years). Serum levels of hepatitis B surface antigen (HBsAg) and hepatitis B surface antibody (anti-HBs) were detected by enzyme linked immunosorbent assay (ELISA). Statistical analysis was conducted by Spearman rank correlation analysis and chi-square test.Results:The overall HepB vaccination rate, timely vaccination rate, and full course vaccination rate among 17 236 children were 98.78%(17 025/17 236), 84.13%(14 500/17 236) and 97.69%(16 838/17 236), respectively. The positive rates of HBsAg and anti-HBs were 0.28%(49/17 236) and 70.57%(12 164/17 236), respectively. From 2013 to 2020, the trend of the vaccination rate, timely vaccination rate, and full vaccination rate of HepB increased year by year. The timely vaccination rate (88.64%(3 989/4 500)) and the positive rate of anti-HBs (92.78%(4 175/4 500)) were the highest at the age of eight to 17 months. Age was negatively correlated with the positive rate of anti-HBs ( rs=-0.427, P<0.001). The vaccination rate, full course vaccination rate, and positive rate of HBsAg in males were higher than those in females ( χ2=4.41, 6.05 and 0.92, respectively, all P<0.05), while the vaccination rate, timely vaccination rate and full course vaccination rate in rural areas were higher than those in urban areas ( χ2=51.75, 4.81 and 33.20, respectively, all P<0.05). The vaccination rate, full course vaccination rate and the positive rate of anti-HBs in minority nationality were higher than those in Han nationality ( χ2=29.44, 11.83 and 5.04, respectively, all P<0.05). The differences were all statistically significant. The positive rates of anti-HBs in individuals with a history of immunization, timely vaccination, and full vaccination of HepB were higher than those in individuals without a history of HepB immunization, timely vaccination, and full vaccination, and the differences were all statistically significant ( χ2=64.67, 65.46 and 13.39, respectively, all P<0.001). Conclusions:The positive rate of anti-HBs in the older age group has decreased significantly. While continuing carrying out routine immunization work, monitoring, strengthening supplementary immunization should be emphasized, and HepB vaccination in older children should be explored to consolidate the immune barrier.

Objective:To investigate the protective effect of hypothermic antegrade machine perfusion against canine ischemic brain injury.Methods:Thirteen beagle dogs were divided into the mild hypothermia with perfusion group ( n=6) and normothermia with perfusion group ( n=7) according to the random number table. The model of ischemic brain injury was established by neck transection. After 1 hour of ischemic circulatory arrest, the perfusion fluid based on autologous blood was continuously perfused through bilateral common carotid artery for 6 hours. The temperature of the perfusion fluid was set at 33 ℃ in the mild hypothermia with perfusion group and 37℃ in the normothermia with perfusion group, respectively. Blood oxygen saturation was recorded at 0, 1, 2, 3, 4, 5 and 6 hours after the beginning of perfusion to evaluate the perfusate oxygen level. The perfusate was collected, and the levels of Na +, K +, Ca 2+ and glucose as well as the pH value of the perfusate were detected in the two groups. At the end of perfusion, the parietal brain tissues of 1 dog from each group were collected to evaluate the water contents of brain tissues. Nissl staining was used to evaluate the morphological integrity of the pyramidal neurons in the frontal cortex and hippocampus. Neuronal nuclei antigen (NeuN) was used to evaluate the structural and morphological integrity of pyramidal neurons. Immunofluorescence glial fibrillary acidic protein (GFAP) and ionic calcium binding adaptor molecule 1 (Iba1) were used to evaluate the integrity and activity of astrocytes and microglia fragments. Results:At 0, 1, 2, 3, 4, 5 and 6 hours of perfusion, there was no significant difference in the blood oxygen saturation or Na + concentrations between the two groups (all P>0.05); the K + concentrations in the mild hypothermia with perfusion group were (4.57±0.12)mmol/L, (4.67±0.14)mmol/L, (4.27±0.12)mmol/L, (4.45±0.10)mmol/L, (6.60±0.15)mmol/L, (7.37±0.18)mmol/L and (9.03±0.16)mmol/L, respectively, which were significantly lower than those in the normothermia with perfusion group [(4.84±0.10)mmol/L, (5.31±0.13)mmol/L, (5.44±0.24)mmol/L, (5.70±0.18)mmol/L, (7.79±0.18)mmol/L, (10.44±0.40)mmol/L, (10.40±0.41)mmol/L] (all P<0.01). At 0, 1, 2 and 3 hours of perfusion, the Ca 2+ concentrations in the mild hypothermia with perfusion group were (0.72±0.15)mmol/L, (1.55±0.16)mmol/L, (1.62±0.15)mmol/L and (1.88±0.15)mmol/L, respectively, being significantly higher than those in the normothermia with perfusion group [(0.41±0.13)mmol/L, (0.99±0.12)mmol/L, (1.29±0.13)mmol/L, (1.57±0.11)mmol/L] (all P<0.01), and no significant differences were found at other time points (all P>0.05). At 0, 1 and 2 hours of perfusion, the glucose concentrations in the mild hypothermia with perfusion group were (5.75±0.19)mmol/L, (5.17±0.15)mmol/L and (4.72±0.15)mmol/L, respectively, being significantly higher than those in the normothermia with perfusion group [(5.30±0.22)mmol/L, (4.89±0.20)mmol/L, (4.30±0.17)mmol/L] (all P<0.01), with no significant differences found at other time points (all P>0.05). At 2, 3, 4, 5 and 6 hours of perfusion, the pH values of the mild hypothermia with perfusion group were 7.32±0.06, 7.25±0.02, 7.23±0.02, 7.24±0.02 and 7.24±0.02, respectively, being significantly higher than those in the normothermia with perfusion group (7.26±0.01, 7.21±0.01, 7.17±0.02, 7.15±0.02, 7.08±0.02) ( P<0.05 or 0.01), with no significant differences at other time points (all P>0.05). The water content of brain tissues in the mild hypothermia with perfusion group was (74.9±0.4)%, which was significantly lower than (79.9±0.9)% in the normothermia with perfusion group ( P<0.01). Nissl staining showed that the pyramidal neurons in prefrontal cortex and dentate gyrus had good integrity in the mild hypothermia with perfusion group. NeuN immunofluorescence staining showed that the morphology and structure of pyramidal neuron cells in the mild hypothermia with perfusion group were better with clearly visible axons than those in the normothermia with perfusion group, whereas the cytosol was full and swollen with scarce axons in the normothermia with perfusion group. GFAP and Iba1 immunofluorescence staining showed that more structurally intact glial cells, more abnormally active cells, thickener axons and better axon integrity in all directions were found in the mild hypothermia with perfusion group than those in the normothermia with perfusion group. Conclusion:Compared with normal temperature antegrade mechanical perfusion, the mild hypothermia antegrade mechanical perfusion can protect canine brain tissue and alleviate ischemic brain injury by maintaining stable energy and oxygen supply, balancing ion homeostasis and perfusion fluid pH value, reducing tissue edema, and maintaining low metabolism of pyramidal neurons, astrocytes and microglia.

Bioactive peptides play important roles in promoting human health, such as lowering blood pressure, blood sugar and blood lipid, anti-obesity, and anti-cancer. Thus, exploring functional bioactive peptides and developing efficient production technologies are of crucial importance. Herein, we review the development of function discovery and production technology for natural bioactive peptides. Presently, the top-down and bottom-up approaches are mainly used for the function discovery and production of natural active peptides. The top-down approach includes the direct extraction and identification for functional discovery, and the direct extraction, enzymatic hydrolysis and microbial fermentation for production. The bottom-up approach includes the polypeptide modification and database mining for functional discovery, and the chemical synthesis, enzyme synthesis, recombinant expression and cell-free synthesis for production. The top-down approach is usually associated with complicated process, lower efficiency, higher cost, harder quality control, and uncertain functionality, while the bottom-up approach is more suitable for the development of peptide drugs but difficult to be used for functional foods. With the technology development of sequencing and mass spectrometry, it is easier to obtain the proteomic information of various organisms at the molecular level. Based on the proteomic information, the top-down and bottom-up approaches can be combined to overcome the disadvantages of using these two approaches alone, thus providing a new strategy for the rapid development and production of natural active peptides.
Fermentation ; Humans ; Mass Spectrometry ; Peptides/metabolism* ; Proteomics ; Technology

【Objective】 To explore the protective effects of exogenous hydrogen sulfide （H2S） on oxygen glucose deprivation and re-oxygenation （OGD/R）-induced SH-SY5Y cell injury. 【Methods】 OGD/R model was established in SH-SY5Y cells. Based on interferences， SH-SY5Y cells were divided into control group （no interference）， OGD/R model group， and treatment groups （OGD/R model treated with different concentrations of NaHS （H2S donor）. The cells were cultured in low glucose medium without fetal bovine serum under 37 ℃， 93% N2 and hypoxia （2% O2） for 12 h， then in complete medium under normoxia （5% O2 ） for 24 h. CCK-8 was used to detect cell viability， and flow cytometry was used for assaying the level of cellular apoptosis. Western blot was used to detect the expression levels of endoplasmic reticulum stress-related proteins including glucose regulatory protein 78 （GRP78）， CCAAT/enhancer-binding homologous protein （CHOP）， NF-κB P65 and COX-2. 【Results】 The cell viability was lower in OGD/R model group than in the control group （P<0.05）. NaHS treatment at a concentration of 0-0.5 mmol/L increased cell viability in OGD/R model group in a dose-dependent manner （P<0.05）. In contrast， NaHS （C>0.5 mmol/L） decreased cell viability of OGD/R （P<0.05）. The apoptosis level of early stage in OGD/R model group was significantly higher than that in control group （P<0.05）. NaHS treatment at concentrations of 0.2 and 0.4 mmol/L lowered the apoptosis level of early stage in OGD/R model group （P<0.05）. Western blot showed that the protein expression levels of GRP78， CHOP， NF-κB p65， and COX-2 were significantly higher in OGD/R model group than those in control group （P<0.05）. When compared with OGD/R model group， the expression levels of GRP78， CHOP， NF-κBp65 and COX-2 were decreased by NaHS at concentrations of 0.2， 0.4 and 4 mmol/L （P<0.05）， but there was no statistically significant difference among the treatment groups （P>0.05）. 【Conclusion】 NaHS can rescue cell viability of OGD/R-induced cell injury. It may be achieved by inhibiting the activation of NF-κBp65 and COX-2 proteins induced by endoplasmic reticulum stress to reduce the level of cell apoptosis.

Objective:To investigate the epidemiological and etiological characteristics of hand-feet-mouth disease (HFMD) in Dali Bai Autonomous Prefecture and to provide scientific evidence for the prevention of HFMD.Methods:The HFMD cases during January 2015 to December 2019 in Dali Bai Autonomous Prefecture were collected through the Chinese Information System for Disease Control and Prevention. The demographic data, incidence rate of HFMD and epidemiological characteristics were analysed. Coxsackie virus A16(CoxA16), enterovirus 71(EV71) and other enterovirus nucleic acid in stool samples of HFMD patients were detected by real-time reverse transcription polymerase chain reaction. Chi-square test was used as statistical method.Results:From 2015 to 2019, 30 730 cases of HFMD were reported in Dali Bai Autonomous Prefecture. The annual incidence rate was 171.50/100 000, and the incidence rate was on rise from 2016 to 2019. There were 24(0.08%) severe cases. Yongping County, Binchuan County and Dali City were with the top three average annual incidence rate. The peak incidence was from June to July in summer, 9 168 cases (29.83%) were reported. The peak incidence was from September to October in autumn, 5 988 cases (19.49%) were reported. The epidemic intensity in summer was higher than that in autumn. Among 30 730 cases, there were 17 373 males and 13 357 females. The annual incidence rate of male patients was 120.29/100 000, and that of female was 75.83/100 000. The difference was statistically significant ( χ2=1 637.467, P<0.01). The highest incidence was in infancy (one to