BACKGROUND:Spleen has the functions of blood storage,hematopoiesis,and immunity.With the increase of age,the structural degeneration and functional decline of spleen lead to the impairment of immune system function,thus accelerating the aging process of the body.The treatment of spleen aging in tree shrews with highly active umbilical cord mesenchymal stem cells has not been reported. OBJECTIVE:To explore the intervention effect and mechanism of highly active umbilical cord mesenchymal stem cells on spleen aging in tree shrews. METHODS:Highly active umbilical cord mesenchymal stem cells were isolated,cultured,and obtained from the umbilical cord tissue of newborn tree shrews by caesarean section.The differentiation abilities of adipogenesis,osteogenesis,and chondrogenesis were detected by three-line differentiation kit.Cell cycle and surface markers were detected by flow cytometry.The second generation of highly active umbilical cord mesenchymal stem cells were transfected with Genechem Green Fluorescent Protein with infection complex values of 100,120,140,160,180,and 200,respectively,to screen the best transfection conditions.After transfection,the fourth generation of highly active umbilical cord mesenchymal stem cells was injected into the tail vein of tree shrews in the elderly treatment group.The young control group and the aged model group were not given special treatment.After 4 months of treatment,the spleen tissue was taken and the structure of the spleen was observed by hematoxylin-eosin staining.β-Galactosidase staining was used to detect the activity of aging-related galactosidase.Immunohistochemical staining was used to detect the expression levels of p21 and p53 proteins.Ki67 and PCNA immunofluorescence staining was used to detect cell proliferation activity.Immunofluorescence staining was used to detect the expression levels of spleen autophagy protein molecules Beclin 1 and APG5L/ATG5.Reactive oxygen species fluorescence staining was used to detect the content of reactive oxygen species in spleen tissue.CD3 immunofluorescence staining was used to detect the change of the proportion of total T lymphocytes.The secretion levels of interleukin 1β and transforming growth factor β1 in spleen were detected by enzyme linked immunosorbent assay.The distribution of highly active umbilical cord mesenchymal stem cells labeled with green fluorescent protein in spleen tissue was observed by DAPI double staining of nucleus. RESULTS AND CONCLUSION:(1)Highly active umbilical cord mesenchymal stem cells grew in a short spindle shape with fish-like growth,with a large proportion of G0/G1 phase,and had the potential to differentiate into adipogenesis,osteogenesis,and chondrogenesis.(2)Multiplicity of infection=140 and transfection for 72 hours were the best conditions for labeling tree shrews highly active umbilical cord mesenchymal stem cells with Genechem Green Fluorescent Protein.(3)Compared with the aged model group,in the aged treatment group,the spleen tissue cells of tree shrews were arranged closely,and the area of white pulp was increased(P<0.01);the boundary between red pulp and white pulp was clear;the proportion of germinal centers did not show statistically significant difference(P>0.05).The activity level of galactosidase related to spleen tissue aging was decreased(P<0.001),and the expression levels of aging protein molecules p21 and p53 were down-regulated(P<0.001).The expression levels of proliferation-related molecules Ki67 and PCNA were up-regulated(P<0.001,P<0.05);expression levels of autophagy-related molecules Beclin 1 and APG5L/ATG5 were up-regulated(P<0.001),and the content of reactive oxygen species decreased(P<0.001),and the proportion of CD3+T cells increased(P<0.05).The secretion level of interleukin 1β in the aging-related secretion phenotype decreased(P<0.001);no significant difference was found in transforming growth factor β1 level(P>0.05).Compared with the young control group,the above indexes were significantly different in the elderly treatment group(P<0.05).(4)Green fluorescent cells labeled with green fluorescent protein were observed in spleen tissue of tree shrews the elderly treatment group by frozen tissue section observation.The results show that intravenous infusion of highly active umbilical cord mesenchymal stem cells can migrate to spleen tissue,inhibit the production of reactive oxygen species,down-regulate the expression of aging-related proteins,induce autophagy,promote cell proliferation,reduce chronic inflammation,and then improve the structure and function of spleen tissue.

BACKGROUND:Adipose-derived stem cells have anti-aging effects,but whether adipose-derived stem cells from donors of different ages are different needs further study. OBJECTIVE:To compare the biological properties of adipose-derived stem cells in old and young mice. METHODS:Adipose-derived stem cells were extracted from adipose tissue of C57BL mice aged 8 and 14 weeks,respectively.The differences of cell cycle,apoptosis,and proliferation of adipose-derived stem cells in old and young mice were compared.The expression levels of aging-related P21 and P27 genes and proteins of adipose-derived stem cells in old and young mice were detected by quantitative PCR and western blot assay. RESULTS AND CONCLUSION:Compared with old mouse adipose-derived stem cells,young mouse adipose-derived stem cells were more active,more regular in morphology,less apoptosis,faster proliferation,and lower in expression of age-related P21 and P27 genes and proteins.It has been proven that adipose-derived stem cells from young mice have better anti-aging effects.

Aging is accompanied by significant inhibition of hematopoietic and immune system function and disruption of bone marrow structure. Aging-related alterations in the inflammatory response, immunity, and stem cell niches are at the root of hematopoietic aging. Understanding the molecular mechanisms underlying hematopoietic and bone marrow aging can aid the clinical treatment of aging-related diseases. In particular, it is unknown how the niche reprograms hematopoietic stem cells (HSCs) in an age-dependent manner to maintain normal hematopoiesis in elderly individuals. Recently, specific inhibitors and blood exchange methods have been shown to reshape the hematopoietic niche and reverse hematopoietic aging. Here, we present the latest scientific discoveries related to hematopoietic aging and hematopoietic system rejuvenation, discuss the relationships between hematopoietic niche aging and HSC aging, and describe related studies on stem cell-mediated regulation of hematopoietic aging, aiming to provide new ideas for further study.

BACKGROUND: This study aimed to develop a comprehensive instrument for evaluating and ranking clinical practice guidelines, named Scientific, Transparent and Applicable Rankings tool (STAR), and test its reliability, validity, and usability. METHODS: This study set up a multidisciplinary working group including guideline methodologists, statisticians, journal editors, clinicians, and other experts. Scoping review, Delphi methods, and hierarchical analysis were used to develop the STAR tool. We evaluated the instrument's intrinsic and interrater reliability, content and criterion validity, and usability. RESULTS: STAR contained 39 items grouped into 11 domains. The mean intrinsic reliability of the domains, indicated by Cronbach's α coefficient, was 0.588 (95% confidence interval [CI]: 0.414, 0.762). Interrater reliability as assessed with Cohen's kappa coefficient was 0.774 (95% CI: 0.740, 0.807) for methodological evaluators and 0.618 (95% CI: 0.587, 0.648) for clinical evaluators. The overall content validity index was 0.905. Pearson's r correlation for criterion validity was 0.885 (95% CI: 0.804, 0.932). The mean usability score of the items was 4.6 and the median time spent to evaluate each guideline was 20 min. CONCLUSION The instrument performed well in terms of reliability, validity, and efficiency, and can be used for comprehensively evaluating and ranking guidelines.
Reproducibility of Results ; Surveys and Questionnaires ; Practice Guidelines as Topic ; Humans

Severe acute pancreatitis is one of the most common surgical emergencies with rapid onset, rapid progression, multiple complications, poor prognosis, and high morbidity and mortality, and it still faces many challenges in treatment. Surgical interventions are crucial in many complications of SAP mainly infected pancreatic necrosis in the late course of the disease, and there is a basic consensus on delayed intervention and trauma ascending treatment model, but over-emphasis on delay may cause patients to miss the best treatment period, and following a single treatment model may delay the patient′s condition. Therefore, it is of great significance for surgeons to grasp the correct indications and timing of surgical intervention and to develop appropriate surgical intervention strategies to reduce the morbidity and mortality of severe acute pancreatitis and improve the clinical prognosis of patients. In this paper, we review the progress of surgical treatment of severe acute pancreatitis with domestic and international literature.

As human life expectancy continues to increase and the birth rate continues to decline, the phenomenon of aging is becoming more prominent worldwide. Therefore, addressing the problems associated with global aging has become a current research focus. The main manifestations of human aging are structural degeneration and functional decline of aging tissues and organs, quality of life decline, decreased ability to resist diseases, and high incidence rates of a variety of senile degenerative diseases. Thus far, no ideal treatments have been found. Stem cell (SC) therapies have broad application prospects in the field of regenerative medicine due to the inherent biological characteristics of SCs, such as their plasticity, self-renewal, and multidirectional differentiation potential. Thus, SCs could delay or even reverse aging. This manuscript reviews the causes of human aging, the biological characteristics of SCs, and research progress on age reversal.

Objective:To analyze the characteristics of malaria epidemic situation before and after malaria elimination in Qiandongnan Prefecture, and to provide the basis for establishment of effective strategies and measures to consolidate the achievements of malaria prevention and control.Methods:The data of malaria cases in 16 counties (cities) of Qiandongnan Prefecture from 2005 to 2018 were collected, and descriptive epidemiological method was used to analyze the infection rate of Plasmodium among local residents and floating population before (2005-2011) and after (2012-2018) elimination of malaria, and the characteristics of population distribution, seasonal distribution, species of Plasmodium and types of malaria vectors were analyzed. Results:Before elimination of malaria, total of 1 412 cases of malaria were reported, among those cases, 1 361 cases were local cases, accounting for 96.39% of the total cases. After elimination of malaria, total of 17 cases were reported, all of them were imported cases. After comparison of malaria cases before and after the elimination, the proportion of people aged from 18 to 60 was 70.54% (996/1 412) before the elimination, all 17 imported cases were 18-60 years old after the elimination, and the proportion of children/students decreased from 24.65% (348/1 412) before the elimination to 0 after the elimination. The peak incidence of malaria cases before the elimination was from June to October, and cases occurred every month. After the elimination, the imported cases were sporadic. Plasmodium vivax was the main species of Plasmodium before the elimination (98.58%, 1 392/1 412), and Plasmodium falciparum was mainly imported after the elimination (70.59%, 12/17). Before and after the elimination, Anopheles sinensis, the malaria vector, was the dominant population, but no distribution of Anopheles minimus and Anopheles anthropophagus was found after 2015. Conclusions:After the elimination of malaria in Qiandongnan Prefecture, there is a risk of local malaria cases caused by imported cases. It is suggested that local authorities should focus on the treatment of suspected malaria cases and vector surveillance of overseas returnees in the future.

Objective: To explore the feasibility of the modified RUSS (Resorlu-Unsal Stone Score) renal stone scoring system in predicting the stone free rate after Flexible Ureteroscopic Lithotripsy(FURL). Methods: Retrospective analysis was performed on 104 cases of renal stones treated by FURL from March 2017 to January 2019 in the second affiliated hospital of zhengzhou university, including 75 males and 29 females. Age 20-75 (47.79±13.21) years. BMI 18.2-38.3 (24.4±3.7) kg/m²; Crushed stone site: left 56 cases, right 48 cases. There were 23 cases of renal inferior calyces calculi, 81 cases of non-inferior calyces calculi, and 19 cases of renal inferior calyces calculi with IPA<45°; American Society of Anesthesiology (ASA) scores: 65 cases of grade Ⅰ, 39 cases of grade Ⅱ; There were 71 patients with urinary tract infection before operation. There were 6 cases of renal puncture fistula before operation. Preoperative indwelling ureteral stent in 26 cases; There were 32 cases with history of extracorporeal shock wave lithotripsy. There were 27 patients with a history of urolithiasis therapy. The same physician used preoperative urinary CT+ 3D reconstruction imaging data to measure the factors influencing the postoperative stone free rate. RUSS renal stone scoring system was used to score the stones of patients before operation, and the relationship between the scores and the stones free rate was analyzed. The RUSS renal stone scoring system was supplemented and improved by including staghorn stone, duplicate renal, caliceal diverticulum, renal malrotation, stone area, and CT value related indexes. The modified RUSS renal stone scoring system was used to score the preoperative stone condition of patients, and the relationship between the score and the stone free rate was analyzed. The receiver operating characteristic curve (ROC) was drawn and the area under the curve (AUC) was calculated to compare the advantages and disadvantages of the modified RUSS, the characteristics of the stones, and RUSS system. Results: The stone free rate was 69.2% (72/104) 4 weeks after the operation, and there were no postoperative complications. Single-factor analysis showed that stone area, CT value, number of renal calyx involved by stone, multiple stones, IPA, stone size grading, renal anatomic structure abnormality, staghorn stone were all related risk factors affecting postoperative patients. Multi-factor analysis showed that stone area, number of renal calyces involved by stone, multiple stones, IPA and stone size were independent risk factors affecting the stone free rate after FURL. RUSS scores ranged from 0 to 3 points, corresponding to stone clearing rates of 86.8% (33/38), 67.7% (23/34), 58.3% (14/24) and 25.0% (2/8), respectively. Stone clearing rates were significantly correlated with stone grading (P<0.05). The total scores of stone free group and residual stone group were (0.87±0.96) points and (1.53±0.98) points, respectively, with significant differences between the groups (P<0.05). The range of modified RUSS score was 0-4 points, corresponding to the stone clearing rate of 100.0% (25/25), 92.3% (24/26), 54.2% (13/24), 47.4% (9/19), and 10.0% (1/10), respectively. Stone free rate was significantly correlated with stone grading (P<0.05). The total scores of stone free group and residual stone group were (1.15±1.13) points and (2.81±0.93) points, respectively, with significant differences between the groups (P<0.05). The AUC of stone features was smaller than that of the modified RUSS scoring system. The AUC of RUSS scoring system (0.707, 95%CI 0.598-0.815) was smaller than that of the modified RUSS scoring system (0.865, 95%CI 0.797-0.933). Conclusions Both the RUSS scoring system and the modified RUSS scoring system could accurately predict the postoperative stone free status of FURL, while the modified RUSS scoring was more accurate than the RUSS scoring.

Objective To investigate the effects of bone marrow mesenchymal stem cells (BMSC) on the expression of inflammatory factors in rats with multiple organ dysfunction syndrome (MODS). Methods BMSC extracted from the 4-week-old Sprague-Dawley (SD) rats was cultivated and identified in vitro, then the 4th passage of which was used in the experimental study. Sixty SD rats were randomly(random number) divided into three groups (n=20 in each group): Sham group (SG), MODS group (MG) and BMSC group (BG). Rats in the MG was injected by 1 mg/kg lipopolysaccaride (LPS) via great saphenous vein, rats in the SG injected with the same volume sterile phosphate buffer saline and rats in the BG infused by 1×106/cells BMSCs through the tail vein at 2 h after LPS injection. The survival rate, tissue pathological changes of the lung, liver and heart by hematoxylin and eosin (HE) staining, organ dysfunction measurement by blood gas analysis and biochemical indicators as well as the related inflammatory factors by protein microarray and enzyme linked immunosorbent assay (ELISA), were detected 72 h post operation. Multi-group quantitative data was analyzed by one way ANOVA, paired-comparisons by LSD-t test and the comparisons of survival curves in the three groups by Log-rank test. The value of P<0.05 was considered statistically significant. Results The survival rate in SG, MG and BG was 100％, 60％ and 80％, respectively. The survival curves showed that the survival rate of SG was higher than the MG and BG (SG vs. MG, χ2=9.798, P=0.0017; SG vs. BG, χ2=4.333, P=0.0374), but there was no significant difference comparing the BG to the MG (χ2=2.408, P=0.1207). The tissue congestion and edema, and inflammatory cells infiltration in the lung, liver, and heart of the MG were observed by HE staining, while these changes reduced in the BG. Compared with the SG, the levels of pH and PaCO2 and lactic acid (Lac) increased significantly (all P<0.01), the level of total bilirubin (TB) significantly increased [(0.801±0.501)U/L vs. (2.533±0.382)U/L, P=0.003], while the albumin(ALB) level decreased significantly[(35.471±4.015)U/L vs. (23.202±4.872)U/L, P<0.01], and creatine kinase (CK) level increased significantly in MG [(315.670±41.402) vs. (708.250±219.201), P=0.042]. After BMSC treatment, the organ function improved significantly (all P<0.05). Gamma interferon (IFN-γ) and monocyte chemotactic protein 1 (MCP-1) were the differential expression factors in protein chips. The results of ELISA were similar to the protein chips: compared with the SG, IFN-γ and MCP-1 expressions in the MG increased significantly (P<0.01). Compared with MG, the expressions of IFN-γ and MCP-1 decreased significantly in the BG (P<0.01). Conclusion BMSC administration could modulate the inflammatory response of MODS rats by inhibiting the levels of IFN-γ and MCP-1, and improve the organ function and the survival rate.

BACKGROUND: Studies have shown that umbilical cord mesenchymal stem cells are ideal seed cells for tissueengineering research.OBJECTIVE: To isolate, culture and identify tree shrew umbilical cord mesenchymal stem cells, in order toestablish a standardized tree shrew umbilical cord mesenchymal stem cell lines.METHODS: Caesarean-isolated tree shrew umbilical cord samples were used to isolate and culture umbilical cordmesenchymal stem cells using tissue explant adherent method. Flow cytometry assay was used to detect cellsurface markers. Osteogenic and adipogenic induction media were used to induce umbilical cord mesenchymalstem cells to differentiate into osteoblasts and adipocytes.RESULTS AND CONCLUSION: The cultured umbilical cord mesenchymal stem cells expressed CD90 and CD105 with the positive rate of 99.9% and 99.8% respectively. Hematopoietic stem cell marker CD34 expression ratewas 0.0% and the endothelial cell marker CD31 expression rate was 0.7%, in line with the characteristics of umbilicalcord mesenchymal stem cell surface markers. Calcium nodules by alizarin red staining and lipid droplets by oil red Ostaining were observed in the induced cells. These experimental findings indicated that umbilical cord mesenchymalstem cells from tree shrews capable of osteogenic and adipogenic differentiation were successfully isolated and cultured.