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Bama miniature pig (BM) as the inbreed pigs is considered to be a potential donor for xenotransplantation. However, porcine endogenous retrovirus (PERV) integrated in pig's genome, is likely to infect human cells in vitro. PERV infection from BM remains unknown. This study aimed to investigate PERV infection in BM in comparison with that of PK15 cells and further to identify the integration sites of PERV from BM (PERV-BM) in human genome. Two full-length PERV-BMs were cloned from 15 isolates of PERV from Bama miniature pigs and sequence analysis indicated that PERV-BM had limited infection to human cells. Subsequently, PBMC from the BM and PK15 cells were co-cultured with HEK293 cells, respectively. Using nested RT-PCR assay and TEM observation, one PERV-BM was observed to infect HEK293 cells with lower transcriptional level than PERV from PK15 cells (PERV-PK) did, while the others showed no sign of transmission of PERV to human cells. Furthermore, 4 and 157 integration sites were identified from PERV-BM-infected HEK293 cells (HEK293-PERV-BM) and PERV-PK- infected HEK293 cells (HEK293-PERV-PK), respectively, which displayed variations of PERV integration. For further verification of the PERV-BM integration, the expression level of cyclin D1, c-myc, p53 and p16 genes of HEK293-PERV-BM decreased significantly while the CDK4 genes were upregulated dramatically in comparison with those of the HEK293-PERV-PK. It is the first time that PERV-BM has been confirmed to be low infection to human cells and highly integration into the PK15 cells. Therefore, BM is a potential xenograft donor due to less PERV transmission to human beings. [ABSTRACT FROM AUTHOR]

Background: Islet cell transplantation is an emerging therapy in the treatment of diabetes mellitus. Differentiation of islet cells from mesenchymal stem cells (MSCs) is a potential solution to the challenge of insufficient donor sources. This study investigated whether human umbilical cord‐derived MSCs could effectively differentiate into insulin‐producing cells (IPCs) and evaluated the therapeutic efficacy of IPCs in treating diabetes. Methods: IPCs were induced from MSCs by a two‐step protocol. IPC expression products were evaluated by western blot and real‐time PCR. IPC insulin secretion was evaluated by ELISA. The viability of IPCs was measured by FDA/PI and dithizone staining. The non‐human primate tree shrew was used as a diabetes model. After a single STZ induction into a diabetes model, a single intraportal transplantation of IPCs, MSCs, or normal saline was performed (n = 6 per group). Blood glucose was monitored for 3 weeks, then the animals were euthanized and the distribution of IPCs in the liver was examined pathologically. Results: After about 3 weeks of in vitro induction, IPCs formed microspheres of 100–200 μm, with >95% viable cells that were dithizone stain positive. IPCs expressed islet‐related genes and proteins and secreted high levels of insulin whether stimulated by low or high levels of glucose. After transplantation of IPCs into diabetic tree shrews, blood glucose levels decreased rapidly to near normal and were significantly lower than the MSC or saline groups for 3 weeks thereafter. Conclusion: We present the novel discovery that IPCs derived from human umbilical cord MSCs exert a therapeutic effect in a non‐human primate model of diabetes. This study provides a preliminary experimental basis for the use of autologous MSC‐derived IPCs in the treatment of human diabetes. [ABSTRACT FROM AUTHOR]

In thiswork, a methodology for characterizing reservoir pore pressure and permeability during underbalanced drilling of horizontal wells was presented. The methodology utilizes a transient multiphase wellbore flow model that is extended with a transient well influx analytical model during underbalanced drilling of horizontal wells. The effects of the density behavior of drilling fluid and wellbore heat transfer are considered in our wellbore flow model. Based on Kneissl's methodology, an improved method with a different testing procedure was used to estimate the reservoir pore pressure by introducing fluctuations in the bottomhole pressure. To acquire timely basic data for reservoir characterization, a dedicated fully automated control real-time data monitoring system was established. The methodology is applied to a realistic case, and the results indicate that the estimated reservoir pore pressure and permeability fit well to the truth values from well test after drilling. The results also show that the real-time data monitoring system is operational and can provide accurate and complete data set in real time for reservoir characterization. The methodology can handle reservoir characterization during underbalanced drilling of horizontal wells. [ABSTRACT FROM AUTHOR]