Objective To promote the differentiation of Flk1+CD31-CD34-cells isolated from adult adipose tissues into pancreatic islet endocrine cells in vitro.Methods Flk1+CD31-CD34-cells were first cultured and plated in medium supplemented with B27,epidermal growth factor(EGF),and basic fibroblast growth factor(bFGF).Next,the culture medium was changed.The glucose concentration in the serum-free medium was increased.At the same time,betacellulin and nicotinamide were added.Reverse transcription polymerase chain reaction(RT-PCR) was used to detect the expression of nestin,ngn3,insulin promoter factor-1(IPF-1),insulin,and glucagon before and after differentiation induction;immunofluorescent staining for nestin,insulin and glucagon and radioimmunoassay(RIA) for insulin.Results Initially,a nestin positive precursor cell population was found,then small round cells increased in number after 6 days.Later on,they were differentiated into islet-like clusters.The induced cells resulted in the formation of clusters which exhibited higher insulin secretion and other pancreatic endocrine hormones.RT-PCR detected an enhanced expression of pancreatic genes in the differentiated cells.Immunofluorescence revealed a high percentage of insulin-expressing cells in the clusters.Furthermore,the intra-cellular insulin content was detected by RIA after the induction culture.Conclusion These cells represent a previously unidentified adult intrinsic pancreatic precursor population and are a promising candidate for cell-based therapeutic strategies.

Objective To explore the factors affecting results of alanine aminotransferase(ALT)preliminary screening by using dry chemical method in blood donors,so as to establish standards of ALT preliminary screening and reduce waste of blood. Methods A total of 21 065 blood specimen of blood donors in Blood Center of Maoming City were collected from January to June 2013.The influences of specimen hemolysis,lipidemia,different sample amount and waiting time after adding sample on the detec-tion results of ALT by using dry chemical method were comparatively analysed,and standardized procedures and established appro-priate limits of ALT preliminary screening according to the results.Results The specimen hemolysis affected test results of ALT, which was not obvious when the hemolysis rate was less than or equal to 0.5%.There was no obvious interference of lipidemia on ALT test.When the sample amount was (32±3)μL or the waiting time after adding sample was 10 to 40 seconds,the detection re-sults of ALT were acceptable.The standard limit of ALT was less than or equal to 40 U/L of female and less than or equal to 45 U/L of male.Conclusion Hemolysis,sample amount and waiting time after adding sample can influence the results of ALT detec-ted by using dry chemical method,while lipidemia had no interference on ALT test.Standardizing operation and reasonably setting normal limits standard may ensure the accuracy and stability of determination,save blood resources,further ensure blood safety, which should be worthy of wide application.

Objective To know the situation of the hepatitis C virus(HCV)infection in blood donors of Maoming City,and pro-vide the basic data for recruiting volunteer blood donors and preventing of HCV infection.Methods Blood samples were collected in Maoming blood center,and were detected by using HCV antibodies of different manufacturers and operated by different people.Du-plicate test was used to reexamine the specimens which were reactive in the initial test.Statistical analysis was performed.Results HCV prevalence of blood donors from Maoming was 0.74%.The prevalence of female was slightly higher than the male,but the difference was not statistically significant(P >0.05).The HCV prevalence of civil servant and medical personnel was relatively low-er.HCV prevalence of repeat blood donors was obviously lower than blood donors for the first time(P <0.05).Conclusion HCV prevalence of blood donors in Maoming City was in a relative low level.The risk of HCV infection in people who is younger than 35 years old and at the same time qualified to donate blood is quite low.Establish a stable volunteer blood donor group is beneficial to blood safety.It's necessary to strength the propaganda and prevention of HCV knowledge to population besides civil servant and medical personnel,which would be helpful for the control of HCV infection.

Objective To study the phenomena and the related mechanisms of malignant transformation of dermis derived multipotential stem cells in vitro . Methods Clonal populations of dermal multipotential stem cells were passaged sequentially in vitro , and the subcutaneous inoculation of cells in nude mice was used for observation of the tumor formation. The transcript profiles of the transformed cells were analyzed by DNA microarray technique. Results Dermal multipotential stem cells underwent spontaneous malignant transformation after serial subculture in vitro . Cells grew out of control, and chromosome number was abnormal. After cells were inoculated subcutaneously into BALB/c nu/nu athymic mice, tumors characterized by fibrous histiocytoma were produced. Immunohistochemistry showed that there were different cell populations for the expression of vimentin, cytokeratin, S 100, and ? smooth actin. Detection by DNA microarray technique revealed that the transformed cells expressed multilineage transcripts, indicating that the transformed cells might have the multipotency. Among the differentially expressed genes in transformed cells, most of the up regulated genes were related to the proliferation process, but most of the down regulated genes were growth factors and their receptors. The enhanced expression of the c ki ras gene and its relevant molecules may play important roles in the transformation process. A candidate gene with unknown functions related to the stem cell proliferation was also preliminarily identified. Conclusion Dermal multipotential stem cells can undergo spontaneous malignant transformation in vitro . Further studies of the mechanisms of this process at the molecular level may have significance both in stem cell application and in tumorigenesis.