Objective:To compare the protective effects of the static cold storage (SCS) and normothermic machine perfusion (NMP) on the skeletal muscle of the amputated limbs of pigs.Methods:Four Landrace pigs were selected, from which eight limbs were amputated and divided into SCS group ( n=5) and NMP group ( n=3) according to the random number table method. After blood collection from the carotid artery, an amputated limb model was established by amputating the limbs at the scapulohumeral joints. The limbs in the SCS group were wrapped in sterile cloth and stored at 4 ℃ for 24 hours. In the NMP group, the limbs were mechanically perfused with a red blood cell-containing perfusion fluid at 37 ℃ for 24 hours, with 70% of the perfusion fluid replaced every 6 hours. Before the experiment, cross-matching tests with the saline medium were conducted between donor and recipient pigs to evaluate blood coagulation and blood safety in the NMP group. An allogeneic red blood cell perfusion fluid was prepared and the levels of pH, Na +, K +, Cl -, Ca 2+, glucose (Glu), hematocrit (Hct), lactic acid (Lac) and osmotic pressure of the perfusion fluid were measured. At 0, 6, 12, 18, and 24 hours after perfusion, the skin temperature and oxyhemoglobin saturation (SaO 2) levels in the NMP group were monitored and the levels of pH, Glu, creatine kinase (Ck), K +, Ca 2+, and Na +levels of the perfusion fluid were analyzed to evaluate the metabolism of the skeletal muscle in the amputated limbs. The mean intercellular distance and apoptosis index of the myocytes were quantitatively analyzed and histopathological changes were observed by performing HE staining and TUNEL staining on the skeletal muscle of the amputated limbs in both groups at 0 and 24 hours after perfusion. After perfusion was ended, the weight gain rate and swelling degree of the amputated limbs were compared between the two groups and the overall state of the amputated limbs was evaluated. Results:The result of the cross-matching test between donor and recipient pig blood was negative. The parameters in the prepared red blood cell-containing perfusion fluid generally maintained within a normal range: pH 7.38±0.04, Na + concentration (138.30±4.48)mmol/L, K + concentration (3.50±0.26)mmol/L, Glu concentration (6.11±2.08)mmol/L, and osmotic pressure (305.67±3.79)mmol/L. However, slightly higher Cl - and Ca 2+ concentrations [(118.34±12.00)mmol/L and (2.00±0.15)mmol/L] and lower Hct and lactate concentrations [0.30±0.03 and (1.54±0.38)mmol/L] were detected when compared with the reference range. During the perfusion, the average skin temperature of the amputated limbs in the NMP group was (36.13±0.98)℃, with the skin temperatures at 6, 12, 18, and 24 hours after perfusion being significantly higher than that at 0 hour ( P<0.01), while no significant difference among the skin temperatures at 6, 12, 18, and 24 hours after perfusion was observed ( P>0.05). The SaO 2 levels in the skin of the amputated limbs in the NMP group averaged over 95%, which showed no significant difference at 0, 12, 18, and 24 hours after perfusion ( P>0.05), while a significant elevation was observed at 6 hours compared with that at 0 hour ( P<0.05). There were no significant differences in pH, Glu, Na +, and Ca 2+ levels in the NMP group at 0, 6, 12, 18, and 24 hours after perfusion ( P>0.05), while the Ck levels at 18 and 24 hours were both significantly higher than that at 6 hours after perfusion ( P<0.05), and the Ck levels at 6, 12, 18, and 24 hours were all significantly higher than that at 0 hour ( P<0.05). The K + level progressively increased with the perfusion time, with significant elevations at 18 and 24 hours after perfusion compared with that at 0 hour ( P<0.05). HE staining revealed well-preserved muscle fiber continuity and regular arrangement in the NMP group and the SCS group at 0 hour, with an intercellular distance of (8.95±0.60)μm. At 24 hours, the NMP group exhibited slight skeletal muscle fiber rupture and swelling, with a slightly increased intercellular distance of (14.75±0.90)μm, significantly greater than that at 0 hour ( P<0.01). At 24 hours, the SCS group showed marked skeletal muscle fiber rupture and swelling, with a significantly increased intercellular distance of (23.51±1.49)μm, significantly larger than those at 0 hour in the same group and at 24 hours in the NMP group ( P<0.01). TUNEL immunofluorescence staining indicated a tiny amount of apoptotic cells in the skeletal muscle in both groups at 0 hour, with an apoptotic index of (4.26±1.62)%. There was a small number of apoptotic cells in the skeletal muscle in the NMP group at 24 hours, with an apoptotic index of (25.94±2.69)%, significantly larger than that in the same group at 0 hour ( P<0.01). The SCS group exhibited a large number of apoptotic cells at 24 hours, with an apoptotic index of (62.97±3.22)%, significantly larger than those at 0 hour in the same group and at 24 hours in the NMP group ( P<0.01). In comparison with the SCS group at 24 hours, the amputated limbs in the NMP group showed red color in the appearance, no symptoms of ischemic muscle contracture and good joint movement despite slight edema in the subcutaneous layer. At 24 hours, the weight gain rate of the amputated limbs was (15.82±0.89)% in the NMP group, significantly higher than (0.97±0.28)% in the SCS group ( P<0.01). Conclusion:Compared with SCS, NMP with the red blood cell-containing perfusion fluid prepared with the allogeneic blood for the amputated limbs of pigs can alleviate the ischemic injury of the muscle fibers and inhibit the apoptosis of the muscle cells by sustaining stable energy and oxygen supply and balancing ion homeostasis and pH of the perfusion fluid.

Objective:To compare the protective effects of the static cold storage (SCS) and normothermic machine perfusion (NMP) on the skeletal muscle of the amputated limbs of pigs.Methods:Four Landrace pigs were selected, from which eight limbs were amputated and divided into SCS group ( n=5) and NMP group ( n=3) according to the random number table method. After blood collection from the carotid artery, an amputated limb model was established by amputating the limbs at the scapulohumeral joints. The limbs in the SCS group were wrapped in sterile cloth and stored at 4 ℃ for 24 hours. In the NMP group, the limbs were mechanically perfused with a red blood cell-containing perfusion fluid at 37 ℃ for 24 hours, with 70% of the perfusion fluid replaced every 6 hours. Before the experiment, cross-matching tests with the saline medium were conducted between donor and recipient pigs to evaluate blood coagulation and blood safety in the NMP group. An allogeneic red blood cell perfusion fluid was prepared and the levels of pH, Na +, K +, Cl -, Ca 2+, glucose (Glu), hematocrit (Hct), lactic acid (Lac) and osmotic pressure of the perfusion fluid were measured. At 0, 6, 12, 18, and 24 hours after perfusion, the skin temperature and oxyhemoglobin saturation (SaO 2) levels in the NMP group were monitored and the levels of pH, Glu, creatine kinase (Ck), K +, Ca 2+, and Na +levels of the perfusion fluid were analyzed to evaluate the metabolism of the skeletal muscle in the amputated limbs. The mean intercellular distance and apoptosis index of the myocytes were quantitatively analyzed and histopathological changes were observed by performing HE staining and TUNEL staining on the skeletal muscle of the amputated limbs in both groups at 0 and 24 hours after perfusion. After perfusion was ended, the weight gain rate and swelling degree of the amputated limbs were compared between the two groups and the overall state of the amputated limbs was evaluated. Results:The result of the cross-matching test between donor and recipient pig blood was negative. The parameters in the prepared red blood cell-containing perfusion fluid generally maintained within a normal range: pH 7.38±0.04, Na + concentration (138.30±4.48)mmol/L, K + concentration (3.50±0.26)mmol/L, Glu concentration (6.11±2.08)mmol/L, and osmotic pressure (305.67±3.79)mmol/L. However, slightly higher Cl - and Ca 2+ concentrations [(118.34±12.00)mmol/L and (2.00±0.15)mmol/L] and lower Hct and lactate concentrations [0.30±0.03 and (1.54±0.38)mmol/L] were detected when compared with the reference range. During the perfusion, the average skin temperature of the amputated limbs in the NMP group was (36.13±0.98)℃, with the skin temperatures at 6, 12, 18, and 24 hours after perfusion being significantly higher than that at 0 hour ( P<0.01), while no significant difference among the skin temperatures at 6, 12, 18, and 24 hours after perfusion was observed ( P>0.05). The SaO 2 levels in the skin of the amputated limbs in the NMP group averaged over 95%, which showed no significant difference at 0, 12, 18, and 24 hours after perfusion ( P>0.05), while a significant elevation was observed at 6 hours compared with that at 0 hour ( P<0.05). There were no significant differences in pH, Glu, Na +, and Ca 2+ levels in the NMP group at 0, 6, 12, 18, and 24 hours after perfusion ( P>0.05), while the Ck levels at 18 and 24 hours were both significantly higher than that at 6 hours after perfusion ( P<0.05), and the Ck levels at 6, 12, 18, and 24 hours were all significantly higher than that at 0 hour ( P<0.05). The K + level progressively increased with the perfusion time, with significant elevations at 18 and 24 hours after perfusion compared with that at 0 hour ( P<0.05). HE staining revealed well-preserved muscle fiber continuity and regular arrangement in the NMP group and the SCS group at 0 hour, with an intercellular distance of (8.95±0.60)μm. At 24 hours, the NMP group exhibited slight skeletal muscle fiber rupture and swelling, with a slightly increased intercellular distance of (14.75±0.90)μm, significantly greater than that at 0 hour ( P<0.01). At 24 hours, the SCS group showed marked skeletal muscle fiber rupture and swelling, with a significantly increased intercellular distance of (23.51±1.49)μm, significantly larger than those at 0 hour in the same group and at 24 hours in the NMP group ( P<0.01). TUNEL immunofluorescence staining indicated a tiny amount of apoptotic cells in the skeletal muscle in both groups at 0 hour, with an apoptotic index of (4.26±1.62)%. There was a small number of apoptotic cells in the skeletal muscle in the NMP group at 24 hours, with an apoptotic index of (25.94±2.69)%, significantly larger than that in the same group at 0 hour ( P<0.01). The SCS group exhibited a large number of apoptotic cells at 24 hours, with an apoptotic index of (62.97±3.22)%, significantly larger than those at 0 hour in the same group and at 24 hours in the NMP group ( P<0.01). In comparison with the SCS group at 24 hours, the amputated limbs in the NMP group showed red color in the appearance, no symptoms of ischemic muscle contracture and good joint movement despite slight edema in the subcutaneous layer. At 24 hours, the weight gain rate of the amputated limbs was (15.82±0.89)% in the NMP group, significantly higher than (0.97±0.28)% in the SCS group ( P<0.01). Conclusion:Compared with SCS, NMP with the red blood cell-containing perfusion fluid prepared with the allogeneic blood for the amputated limbs of pigs can alleviate the ischemic injury of the muscle fibers and inhibit the apoptosis of the muscle cells by sustaining stable energy and oxygen supply and balancing ion homeostasis and pH of the perfusion fluid.

Objective To analyze the adolescent tuberculosis reported in Haikou region between 2018 and 2021 and factors influencing the outcome. Methods The data on adolescent tuberculosis cases reported in Tuberculosis Information Management System in the Haikou Regional Centre for Disease Control and Prevention (RCDC) from 2018 to 2021 were collected. A follow-up survey was carried out until 31 December 2022. The changes in reported incidence of adolescent tuberculosis in Haikou was analyzed, and multivariate Cox proportional hazards regression models were used to identify independent factors influencing the outcome of adolescent tuberculosis. Results A total of 265 cases of tuberculosis in adolescents were reported between 2018 and 2021, of which 55 were reported in 2018, 74 in 2019, 67 in 2020, and 69 in 2021. The total number of reported cases of tuberculosis was 140 among male adolescents, which was slightly higher than 125 among female adolescents. The number of reported cases of tuberculosis was 134 in adolescents ≥15 years of age and 131 in adolescents <15 years of age. No statistically significant difference was reported between good outcome group and poor outcome group in age, gender, place of residence, nationality, and domicile place (P>0.05), whereas difference was found in the history of tuberculosis between two groups (P<0.05). Multivariate Cox proportional hazards regression model denoted that retreated tuberculosis (HR: 2.172, 95%CI: 1.483-3.007), complicating underlying disease (HR: 1.451, 95%CI: 1.080-1.985), and number of sputum smears (HR: 2.617, 95%CI: 1.531-3.458) were the risk factors for adverse outcomes in adolescent tuberculosis. Conclusion From 2018 to 2021, the number of reported adolescents of pulmonary tuberculosis in Haikou increased, suggesting that the management and prevention of adolescents should be strengthened to improve the prognosis rate of adolescents.

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.

Although blood banks based on human blood can provide blood transfusions for the wounded timely and effec-tively,scientific research has never given up on finding new blood sources due to the restrictions of human blood sources.With the application of transgenic technology and the successful breeding of gene-edited pigs,gene-edited pig blood as a po-tential source of clinical transfusion has attracted wide attention.Now there are preclinical studies showing the feasibility of transfusing gene-edited pig red blood cells into primates.This paper discusses the related research and future development of xenogeneic transfusion of porcine red blood cells by gene editing.

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.

Objective To investigate the establishment of a six-gene-edited pig-to-non-human primate kidney xenotransplantation model. Methods The kidney of humanized genetically-edited pig (GTKO/β4GalNT2KO/CMAHKO/hCD55/hCD46/hTBM) was transplanted into a cynomolgus monkey. The survival of the recipient and kidney condition after blood perfusion were observed. The parenchymal echo, blood flow changes, and size of the kidney were monitored on a regular basis. Routine blood test, kidney function test and electrolyte assessment were carried out. Dynamic changes of urine, feces and body mass were monitored. At the end of life, the transplant kidney, heart, liver, spleen, lung, and cecum were collected for pathological examination. Results The recipient died at postoperative 7 d. After blood flow was restored, the kidney was properly perfused, the organ was soft and the color was normal. At the end of the recipient's life, a slight amount of purulent secretion was attached to the ventral side of the kidney, with evident congestion and swelling, showing the appearance of "red kidney". Postoperatively, the echo of renal parenchyma was increased, blood flow was decreased, the cortex was gradually thickened, and a slight amount of effusion surrounded the kidney and abdominal cavity over time. In the recipient, the amount of peripheral red blood cells, hemoglobin, albumin, and platelets was progressively decreased, and serum creatinine level was increased to 308 μmol/L at postoperative 7 d, whereas the K⁺ concentration did not significantly change. Light yellow urine was discharged immediately after surgery, diet and drinking water were resumed within postoperative 3 h, and light yellow and normal-shape stool was discharged. The reddish urine was gradually restored to normal color within postoperative 1 d, which were consistent with the results of the routine urine test. A large amount of brown bloody stool was discharged twice in the morning of 2 d after surgery. Omeprazole was given for acid suppression, and the stool returned to normal at postoperative 4 d. The β₂-microglobulin level was increased to 0.75 mg/L at postoperative 7 d. The body mass was increased by 1.7 kg. Autopsy pathological examination showed interstitial edema and bleeding of the transplant kidney, a large amount of infiltration of lymphocytes and macrophages, infiltration of lymphocytes in the arteriole wall and arterial cavity, accompanied by arteritis changes, lymphocyte infiltration in the cecal stroma and congestion in the spleen tissues. No significant abnormal changes were observed in other organs. Conclusions The humanized genetically-edited pig-to-non-human primate kidney xenotransplantation model is successfully established, and postoperative survival of the recipient is 1 week.

To describe a novel particles surface display system which is consisted of gram-positive enhancer matrix (GEM) particles and anchor proteins for bacteria-like particles vaccines, we treated Lactobacillus rhamnosus GG bacteria with 10% heated-TCA for preparing GEM particles, and then identified the harvested GEM particles by electron microscopy, RT-PCR and SDS-PAGE. Meanwhile, Escherichia coli was induced to express hybrid proteins PA3-EGFP and P60-EGFP, and GEM particles were incubated with them. Then binding of anchor proteins were determined by Western blotting, transmission electron microscopy, fluorescence microscopy and spectrofluorometry. GEM particles preserved original size and shape, and proteins and DNA contents of GEM particles were released substantially. The two anchor proteins both had efficiently immobilized on the surface of GEM. GEM particles that were bounded by anchor proteins were brushy. The fluorescence of GEM particles anchoring PA3 was slightly brighter than P60, but the difference was not significant (P>0.05). GEM particles prepared from L. rhamnosus GG have a good binding efficiency with anchor proteins PA3-EGFP and P60-EGFP. Therefore, this novel foreign protein surface display system could be used for bacteria-like particle vaccines.

Human beta defensin 2 (HBD-2) may play an important role in human defense against infection. Its antimicrobial capacity has been fully documented in in vitro study. In order to evaluae its in vivo effects, we developed an HBD-2 transgenic mouse model. The HBD-2 minigene containing CMV promoter, full length of HBD-2 cDNA and BGH polyA tail was generated by PCR amplification and introduced into the fertilized oocytes of C57 X ICR hybridized mouse by microinjection, and offspring were produced. DNA was isolated from the tails of the mouse pups, and the HBD-2 minigene incorporation was analyzed by PCR using HBD-2 specific primers. The HBD-2 gene expression in the multi-tissues of transgenic mice was determined at mRNA level by RT-PCR and at peptide level by immunohistological staining with the use of HBD-2 monoclonal antibody. The results showed that among 17 F0 transgenic mice, HBD-2 positive signal was determined by PCR in 4 mice, suggesting that HBD-2 minigene has been incorporated into the offspring mice. Meanwhile, a widespread expression of HBD-2 mRNA and peptide was detected in the F1 transgenic mice's multi-tissues such as trachea, lung, intestine, esophagus, testis, spleen, skin, endothelium and brain.
Animals ; Anti-Infective Agents ; Humans ; Mice ; Mice, Inbred C57BL ; Mice, Inbred ICR ; Mice, Transgenic ; Models, Animal ; Polymerase Chain Reaction ; RNA, Messenger ; analysis ; biosynthesis ; genetics ; beta-Defensins ; biosynthesis ; genetics

Total RNA was extracted from human LAK cell, and a cDNA encoding mature peptide HMG-17 and its alpha helix domain was amplified by RT-PCR. The recombinant prokaryotic expression vector pGEX-1lambdaT-HMG-17 and pGEX-1lambdaT HMG-17alpha helix was constructed. Using affinity chromatography, thrombin cleaving and AU-PAGE elution, we obtained the purified HMG-17. Analyses of MIC, MEC and MBC indicated that HMG-17 and HMG-17alpha had strong antibacterial activity. MIC of the alpha-helic domain was almost the same as that of HMG17, suggesting that the alpha-helic structure would be essential for the antibacterial activity of HMG-17.
Anti-Bacterial Agents ; biosynthesis ; pharmacology ; Escherichia coli ; genetics ; metabolism ; HMGN2 Protein ; biosynthesis ; genetics ; pharmacology ; Humans ; Killer Cells, Lymphokine-Activated ; chemistry ; Peptides ; genetics ; pharmacology ; Prokaryotic Cells ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics ; pharmacology