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Objective:To explore the selection criteria of the donor for islet transplantation of Chinese people by analyzing the correlation between pancreas characteristics and success rate of islets isolation.Methods:Data from 113 cases of human islet isolation were collected. According to the result of islet isolation, the donors were divided into two groups, the success group(IEQ≥250 000, purification≥30%, and viability≥80%), and the failure group(IEQ<250 000, or purification<30%, or viability<80%). The modified Ricordi method was used to digest pancreas tissue, and the continuous density gradient method was performed to purify islets. The islets were identified by staining with the Dithizone(DTZ), the islets were analyzed for cell viability and purity.Results:The donor age in success group was significantly younger than failure group in the range of age eligible for this study( t=2.479, P=0.015). Pearson correlation showed that donor age was positively corelated with islet yield( r=-0.214, P=0.047). There was more fat on the pancreas surface in the successful islet isolation group( z=-2.007, P=0.045). The digestibility( t=2.133, P=0.035) and recovery rate( t=5.912, P=0.001) were elevated in success group. Conclusion:The pancreases from younger donors could obtain the higher-yielding islet, the pancreas with more surface fat or with higher weight was associated with islet isolation success in the scope covered by the inclusion criteria of this study.
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Objective:To investigate the correlations of β cell dedifferentiation in non-diabetic subjects with risk factors for type 2 diabetes mellitus(T2DM).Methods:Immunofluorescence staining with insulin and β cell dedifferentiated marker ALDH1A3 was used to evaluate the β cell dedifferentiation levels in 38 non-diabetic and 23 T2DM. Correlation analyses were performed between β cell dedifferentiation levels and available clinical parameters including age, body mass index, HbA 1C level, triglycerides, and cholesterol levels in non-diabetic subjects. Results:β cell dedifferentiation level defined by the positive expression of ALDH1A3 in β cells(ALDH1A3 + INS + cell proportion) was significantly elevated in T2DM subjects( P<0.001). In PreD subjects, ALDH1A3 + INS + cells proportion were decreased( P=0.050) and negatively correlated with HbA 1C( r=-0.44, P=0.006), but not with age and body mass index. The analysis of correlation with lipidemic parameters showed that ALDH1A3 + INS + cells proportion was positively correlated with plasma total cholesterol level( r=0.39, P=0.045), but not plasma total triglyceride. Conclusion:ALDH1A3 + INS + cells were found to be decreased in prediabetes, suggesting that there may be enhanced β-cell identity in prediabetes to compensate for insulin secretion requirements; ALDH1A3 + INS + cells were elevated in people with high plasma total cholesterol levels, suggesting that total cholesterol may be one of the factors that induce β-cell dedifferentiation.
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Background and Objectives@#Adipose tissue-derived mesenchymal stem cells (ASCs) are recognized as an advantaged source for the prevention and treatment of diverse diseases including type 2 diabetes mellitus (T2DM). However, alterations in characteristics of ASCs from the aforementioned T2DM patients are still obscure, which also hinder the rigorous and systematic illumination of progression and pathogenesis. @*Methods@#and Results: In this study, we originally isolated peripancreatic adipose tissue-derived mesenchymal stem cells from both human type 2 diabetic and non-diabetic donors (T2DM-ASCs, ND-ASCs) with the parental consent, respectively. We noticed that T2DM-ASCs exhibited indistinguishable immunophenotype, cell vitality, chondrogenic differentiation and stemness as ND-ASCs. Simultaneously, there’s merely alterations in migration and immunoregulatory capacities in T2DM-ASCs. However, differing from ND-ASCs, T2DM-ASCs exhibited deficiency in adipogenic and osteogenic differentiation, and in particular, the delayed cell cycle and different cytokine expression spectrum. @*Conclusions@#The conservative alterations of T2DM-ASCs in multifaceted characteristics indicated the possibility of autologous application of ASCs for cell-based T2DM treatment in the future.
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Objective To retrospectively compare the efficacy of Serva NB1 collagenase with Vitacyte GOLD collagenase on islet isolation of pancreas.Methods All the human pancreata were obtained from Chinese organ donors.In GMP laboratory,the pancreata were trimmed and distended with Serva NB1 collagenase (Serva NB1,n =12) or Vitacyte GOLD collagenase (Vitacyte GOLD,n =5) and digested according to a modified Ricordi semi-automatic protocol,and the digestion duration was recorded.The digested islets were then collected and washed,followed by the continuous density purification in a Cobe 2991 cell separator.The islet yield,purity,viability and glucose-stimulated insulin release (GSI) were determined each time after purification.Quantity and quality of isolated islets were determined by digestion efficacy.Results The digestion duration in Vitacyte GOLD collagenase group was significantly shorter than in Serva NB1 collagenase group to achieve the same digestion endpoint (P＜ 0.05).The islets yields of different sizes were variable between the two groups.The Vitacyte GOLD collagenase digestion produced more islets with a diameter range of 50-100 μm than the ServaNB1 collagenase digestion (P＜0.05),but the latter yielded more islets with a diameter range of 251-300 μm and 301-350μm (P＜0.05).There was no significant difference in total islets yields,viability,and GSI between two collagenase digestions (P＞0.05).Conclusion Both Vitacyte GOLD collagenase and Serva NB1 collagenase can be used for the clinical islet isolation in China.
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BACKGROUND:B-lymphocytes are an important participant in the immunity system. Currently, magnetic beads and complement methods are mainly used to isolate and purify B-lymphocytes. However, these methods are costly or cause large cel damage and low purity, which need further improvement. OBJECTIVE: To explore the isolation and culture methods of B-lymphocytes from mouse spleen and to study suitable conditions for B-lymphocyte isolation and culture in vitro by using interleukin-4, lipopolysaccharide, CD3 monoclonal antibody or their combination. METHODS:B-lymphocytes from mouse spleen were isolated and randomly divided into seven groups, respectively treated with interleukin-4, CD3 monoclonal antibody, lipopolysaccharide, interleukin-4+CD3, interleukin-4+lipopolysaccharide, CD3+lipopolysaccharide, and no stimulation (control group). Flow cytometry was used to detect the changes in the number and proportion of T-lymphocytes, B lymphocytes, and their subpopulations under different culture conditions. RESULTS AND CONCLUSION:The number of lymphocytes peaked at 3-5 days after addition of interleukin-4. In the lipopolysaccharide group, the number of lymphocytes began to increase at 3 days, and then peaked at 5 days. T-lymphocytes disappeared after addition of CD3 monoclonal antibody, so relatively pure B-lymphocytes could be obtained after 2 days and the number of B-lymphocytes reached the peak at 3 days. The number of mature B-lymphocytes (B220+IgD+) increased significantly after addition of CD3 antibody. In al the conditions we tested, transitional B cel subset (B220+CD93+) disappeared completely after 24 hours of culture. Experimental results indicate that after addition of CD3 monoclonal antibody and interleukin-4, T-lymphocytes can be removed in mouse spleen cels cultured, but mature B-lymphocytes remain to survive and proliferate.