[Protective Effect of Mesenchymal Stem Cell Transplantation on Intestinal Injury in Septic Mice and Its Mechanism].

Objective: To explore the protective effect of placenta-derived mesenchymal stem cells (P-MSCs) transplantation on intestinal injury in septic mice and its mechanism. Methods: A total of 24 mice were randomly assigned to 3 groups, a sham operation group, a sepsis group that underwent cecal ligation and puncture (CLP) procedure, and a group that received CLP and P-MSCs treatment. Hereinafter, the three groups are referred to as the Sham group, the CLP group, and the CLP+P-MSCs group. For the mice in the Sham group, the abdomen was cut open and the cecum was exposed and then placed back in the abdomen. CLP was performed in the other two groups to establish the sepsis model. Mice in the Sham and the CLP groups received 0.1 mL of 0.9% NaCl injection in the tail vein 1 hour after operation, while mice in the CLP+P-MSCs group received 2×10 5 P-MSCs infusion 1 hour after operation. Intestinal and blood specimens were collected from the mice in each group 24 hours after P-MSCs transplantation. Hematoxylin and eosin (HE) staining of the intestinal tissue was performed for pathological evaluation. The serum concentrations of D-lactic acid, diamine oxidase (DAO), endotoxin, interleukin (IL)-1ß, tumor necrosis factor (TNF)-α, IL-6, IL-10, and transforming growth factor (TGF)-ß were determined by enzyme linked immunosorbent assay (ELISA). The gene expression of the relevant inflammatory factors in the small intestinal tissue was determined by real-time fluorescence polymerase chain reaction. The expression of zonula occludens protein-1 (ZO-1) and occludin protein in the intestine was determined by Western blot, the infiltration of intestinal macrophages was determined by immunohistochemical method, and the polarization of macrophages was determined by immunofluorescence. Results: The exogenous transplantation of P-MSCs could form colonies in the injured intestines of septic mice. Compared with those of the CLP group, the intestinal injury of the CLP+P-MSCs group was significantly alleviated, the serum concentrations of D-lactic acid, DAO, endotoxin, IL-1ß, IL-6, and TNF-α were significantly decreased ( P<0.05), while the serum concentrations of IL-10 and TGF-ß were significantly increased ( P<0.05), the expression levels of IL-1 ß, TNF-α and IL-6 genes in the intestinal tissue were significantly decreased ( P<0.05), while the expression levels of IL-10 and TGF-ß genes were significantly increased ( P<0.05), and the expression of ZO-1 and occludin proteins in the intestine was also significantly increased ( P<0.05). In addition, the distribution of macrophages in the intestinal tissue of the CLP+P-MSCs group decreased significantly and the macrophages showed a tendency for M2 polarization. Conclusion: Exogenous transplantation of P-MSCs can significantly reduce inflammatory injury and improve the intestinal barrier function in septic mice with intestinal injury. Reduction in the infiltration of macrophages and promotion of the polarization of macrophages from M1 to M2 may be the mechanisms underlying the reduction of inflammation.

Genome-wide map of N6-methyladenosine circular RNAs identified in mice model of severe acute pancreatitis.

BACKGROUND: Severe acute pancreatitis (SAP) is a deadly inflammatory disease with complex pathogenesis and lack of effective therapeutic options. N6-methyladenosine (m6A) modification of circRNAs plays important roles in physiological and pathological processes. However, the roles of m6A circRNA in the pathological process of SAP remains unknown. AIM: To identify transcriptome-wide map of m6A circRNAs and to determine their biological significance and potential mechanisms in SAP. METHODS: The SAP in C57BL/6 mice was induced using 4% sodium taurocholate salt. The transcriptome-wide map of m6A circRNAs was identified by m6A-modified RNA immunoprecipitation sequencing. The biological significance of circRNAs with differentially expressed m6A peaks was evaluated through gene ontology and Kyoto Encyclopedia of Genes and Genomes analysis. The underlying mechanism of m6A circRNAs in SAP was analyzed by constructing of m6A circRNA-microRNA networks. The expression of demethylases was determined by quantitative polymerase chain reaction and western blot to deduce the possible mechanism of reversible m6A process in SAP. RESULTS: Fifty-seven circRNAs with differentially expressed m6A peaks were identified by m6A-modified RNA immunoprecipitation sequencing, of which 32 were upregulated and 25 downregulated. Functional analysis of these m6A circRNAs in SAP found some important pathways involved in the pathogenesis of SAP, such as regulation of autophagy and protein digestion. In m6A circRNA-miRNA networks, several important miRNAs participated in the occurrence and progression of SAP were found to bind to these m6A circRNAs, such as miR-24-3p, miR-26a, miR-92b, miR-216b, miR-324-5p and miR-762. Notably, the total m6A level of circRNAs was reduced, while the demethylase alkylation repair homolog 5 was upregulated in SAP. CONCLUSION: m6A modification of circRNAs may be involved in the pathogenesis of SAP. Our findings may provide novel insights to explore the possible pathogenetic mechanism of SAP and seek new potential therapeutic targets for SAP.

Epigallocatechin-3-gallate attenuates acute pancreatitis induced lung injury by targeting mitochondrial reactive oxygen species triggered NLRP3 inflammasome activation.

Green tea has been considered as a health-promoting beverage and is widely consumed worldwide. Epigallocatechin-3-gallate (EGCG), the most abundant polyphenol derived from green tea leaves with potent antioxidative and chemopreventive activities, has been reported to offer protection against inflammation-driven tissue damage. Here, we evaluated the protective effects of EGCG against lung injury during acute pancreatitis (AP) and further revealed the detailed mechanism. The results showed that EGCG significantly attenuated l-arginine-induced AP and the consequent pulmonary damage in mice. Moreover, EGCG substantially attenuated oxidative stress and concurrently suppressed NOD-like receptor protein 3 (NLRP3) inflammasome activation in the lung. In vitro, EGCG considerably reduced the production of mitochondrial reactive oxygen species (mtROS) and oxidized mitochondrial DNA (ox-mtDNA) in alveolar macrophages (AMs) challenged with AP-conditioned plasma. Meanwhile, the amount of ox-mtDNA bound to NLRP3 decreased significantly by the treatment with EGCG, resulting in impaired NLRP3 inflammasome activation. In addition, the antagonism of NLRP3 signaling by EGCG was affected in the presence of the mtROS stimulant rotenone or scavenger Mito-TEMPO. Altogether, EGCG possesses potent activity to attenuate lung injury during AP progression by inhibiting NLRP3 inflammasome activation. As for the mechanism, the EGCG-conferred restriction of NLRP3 inflammasome activation probably arises from the elimination of mtROS as well as its oxidative product ox-mtDNA, which consequently enables the protection against AP-associated lung injury.

The Knowledge and Attitude Towards Advance Care Planning Among Chinese Patients with Advanced Cancer.

To describe the knowledge and attitude of Chinese patients with advanced cancer towards advanced care planning (ACP), a convenience sample of 275 patients with advanced cancer was recruited from a tertiary cancer hospital in Beijing, China, between February and December 2017. The multi-item questionnaire focused on patients' demographics, disease characteristics and knowledge about and attitude towards ACP and was administered to eligible patients. Descriptive statistics were performed. Most patients had never heard about ACP (82.2%) and had never talked about ACP (83.0%), but only a few (18.3%) were not willing to talk about ACP. A total of 67.8% patients chose to refuse resuscitation attempts or life-sustaining medical interventions, and 70.8% of patients hoped to have surrogate decision makers when they became unconscious. By binary logistic regression analysis, patients who were of greater age, female and living in urban areas preferred to refuse resuscitation attempts or life-sustaining medical interventions (OR = 1.023, P = 0.042; OR = 2.011, P = 0.020; OR = 0.254, P < 0.01); patients who had very rich or rich family economic status preferred to involve surrogate decision makers compared with patients of very poor family economic status (OR = 0.250, P = 0.011). There is a large gap between the knowledge about ACP and the expectation of implementing ACP in Chinese patients with advanced cancer. To develop culturally appropriate and individualized programmes to promote knowledge and implementation in practice of ACP among Chinese patients with advanced cancer and their relatives is still a significant challenge.

Calcitonin gene-related peptide attenuates angiotensin II-induced ROS-dependent apoptosis in vascular smooth muscle cells by inhibiting the CaMKII/CREB signalling pathway.

Apoptosis is associated with various cardiovascular diseases. CGRP exerts a variety of effects within the cardiovascular system, and protects against the onset and development of angiotensin (Ang) II-induced vascular dysfunction and remodelling. However, it is not known whether CGRP has a direct effect on Ang II-induced apoptosis in vascular smooth muscle cells (VSMCs), and the mechanism underlying the anti-apoptotic role remains unclear. In this study, CGRP significantly suppressed reactive oxygen species (ROS) and apoptosis in Ang II-induced VSMCs. In VSMCs pre-treated with a CGRP receptor antagonist (CGRP8-37), the CGRP-mediated inhibition of Ang II-induced ROS and apoptosis was completely abolished. Moreover, pre-treatment with N-acetyl-L cysteine (NAC), an ROS scavenger, blocked the effects of CGRP on Ang II-induced apoptosis. In addition, the activation of CaMKII and the downstream transcription factor CREB stimulated by Ang II was abrogated by CGRP. Importantly, in both CGRP and NAC-treated VSMCs, CGRP failed to further attenuate CaMKII and CREB activation. The results demonstrate that CGRP attenuated Ang II-induced ROS-dependent apoptosis in VSMCs by inhibiting the CaMKII/CREB signalling pathway.

Abdominal paracentesis drainage ameliorates severe acute pancreatitis in rats by regulating the polarization of peritoneal macrophages.

AIM: To investigate the role of peritoneal macrophage (PM) polarization in the therapeutic effect of abdominal paracentesis drainage (APD) on severe acute pancreatitis (SAP). METHODS: SAP was induced by 5% Na-taurocholate retrograde injection in Sprague-Dawley rats. APD was performed by inserting a drainage tube with a vacuum ball into the lower right abdomen of the rats immediately after the induction of SAP. To verify the effect of APD on macrophages, PMs were isolated and cultured in an environment, with the peritoneal inflammatory environment simulated by the addition of peritoneal lavage in complete RPMI 1640 medium. Hematoxylin and eosin staining was performed. The levels of pancreatitis biomarkers amylase and lipase as well as the levels of inflammatory mediators in the blood and peritoneal lavage were determined. The polarization phenotypes of the PMs were identified by detecting the marker expression of M1/M2 macrophages via flow cytometry, qPCR and immunohistochemical staining. The protein expression in macrophages that had infiltrated the pancreas was determined by Western blot. RESULTS: APD treatment significantly reduced the histopathological scores and levels of amylase, lipase, tumor necrosis factor-α and interleukin (IL)-1ß, indicating that APD ameliorates the severity of SAP. Importantly, we found that APD treatment polarized PMs towards the M2 phenotype, as evidenced by the reduced number of M1 macrophages and the reduced levels of pro-inflammatory mediators, such as IL-1ß and L-selectin, as well as the increased number of M2 macrophages and increased levels of anti-inflammatory mediators, such as IL-4 and IL-10. Furthermore, in an in vitro study wherein peritoneal lavage from the APD group was added to the cultured PMs to simulate the peritoneal inflammatory environment, PMs also exhibited a dominant M2 phenotype, resulting in a significantly lower level of inflammation. Finally, APD treatment increased the proportion of M2 macrophages and upregulated the expression of the anti-inflammatory protein Arg-1 in the pancreas of SAP model rats. CONCLUSION: These findings suggest that APD treatment exerts anti-inflammatory effects by regulating the M2 polarization of PMs, providing novel insights into the mechanism underlying its therapeutic effect.

Expression characteristics of KAI1 and vascular endothelial growth factor and their diagnostic value for hepatocellular carcinoma.

BACKGROUND/AIMS: We tried to investigate the expression characteristics of KAI1, a suppressor of wide-spectrum tumor metastasis, and vascular endothelial growth factor (VEGF), the most common angiogenesis factor, and then to analyze their diagnostic value for hepatocellular carcinoma (HCC). METHODS: The protein and mRNA expression levels of KAI1 or VEGF in HCC tissues and in self-controlled para-carcinoma tissues were analyzed by Western blot and real-time polymerase chain reaction, respectively. Serum levels of KAI1 and VEGF in the patients with HCC, benign liver disease or in healthy controls were quantitatively detected by enzyme-linked immunosorbent assay. RESULTS: The expression level of KAI1 was downregulated, while the expression level of VEGF was upregulated in the tissues or serum of the patients with HCC. The expression level of serum KAI1 in HCC patients was correlated with TNM staging, intrahepatic metastasis, lymph node or peritoneal metastasis, and portal vein thrombus. In addition to the factors that were correlated with KAI1 expression, VEGF expression was also closely related to the α-fetoprotein level of the patients. The area under the receiver operating characteristic curve for the diagnosis of HCC was 0.907 for KAI1 and 0.779 for VEGF. The sensitivity of serum KAI1 levels in the diagnosis of HCC was 86.96%; the accuracy was 83.06%, while the sensitivity, the accuracy and the negative predictive value were improved to 91.86%, 84.68%, and 78.79% according to the combined detection of KAI1 and VEGF, respectively. CONCLUSIONS: A combined detection of KAI1 and VEGF may greatly improve the efficiency of diagnosis and form a reliable panel of diagnostic markers for HCC.

The spatiotemporal development of intercalated disk in three-dimensional engineered heart tissues based on collagen/matrigel matrix.

Intercalated disk (ID), which electromechanically couples cardiomyocytes into a functional syncitium, is closely related to normal morphology and function of engineered heart tissues (EHTs), but the development mode of ID in the three-dimensional (3D) EHTs is still unclear. In this study, we focused on the spatiotemporal development of the ID in the EHTs constructed by mixing neonatal rat cardiomyocytes with collagen/Matrigel, and investigated the effect of 3D microenvironment provided by collagen/Matrigel matrix on the formation of ID. By histological and immmunofluorescent staining, the spatiotemporal distribution of ID-related junctions was detected. Furthermore, the ultra-structures of the ID in different developmental stages were observed under transmission electron microscope. In addition, the expression of the related proteins was quantitatively analyzed. The results indicate that accompanying the re-organization of cardiomyocytes in collagen/Matrigel matrix, the proteins of adherens junctions, desmosomes and gap junctions redistributed from diffused distribution to intercellular regions to form an integrated ID. The adherens junction and desmosome which are related with mechanical connection appeared earlier than gap junction which is essential for electrochemical coupling. These findings suggest that the 3D microenvironment based on collagen/Matrigel matrix could support the ordered assembly of the ID in EHTs and have implications for comprehending the ordered and coordinated development of ID during the functional organization of EHTs.

Expression changes and regulation of AR and IGF-1 in PC3 prostate cancer cells treated with sexual hormones and flutamide.

The study aims to investigate the changes and regulation of androgen receptor and insulin-like growth factor-1 in the PC3 prostate cells treated with 5α-dihydrotestosterone, estrone, and flutamide. The PC3 cells were cultured and treated with 5α-dihydrotestosterone, estrone, and flutamide. Immunocytochemistry and Western blot were used to detect the expression of androgen receptor and insulin-like growth factor-1. The androgen receptor expression was analyzed by Western blot and optic density scan in the presence or absence of various kinase inhibitors. The statistical calculations were performed with the statistics-analyzing software package SPSS 13.0. A P <0.05 was considered statistically significant. The concentrations of 5α-dihydrotestosterone and flutamide could almost not change the expression of androgen receptor and insulin-like growth factor-1 in PC3. But, the concentrations of estrone could increase the expression of androgen receptor and insulin-like growth factor-1 when PC3 cells are exposed to the studied concentration at various times. The expression of androgen receptor was regulated by the inhibitor of signal pathways of PI3, MEK1/2, and JUK. The expressions of androgen receptor and insulin-like growth factor-1 were influenced by estrone and were not influenced by 5α-dihydrotestosterone and flutamide in PC3 cells. And, the expression of androgen receptor was regulated by multiple signal pathways.

Overexpression of ßIII-tubulin and survivin associated with drug resistance to docetaxel-based chemotherapy in advanced gastric cancer.

PURPOSE: To study the roles of ßIII-tubulin and survivin in the development of gastric cancer, and see for any relationship between the expression levels of these two genes and docetaxel chemoresistance in advanced gastric cancer. METHODS: Patients with advanced gastric cancer treated with docetaxel-based chemotherapy were enrolled and their tumor samples were collected retrospectively for analysis (study group). The control group consisted of patients with benign gastric mucosa lesions. Expression levels of ßIII-tubulin and survivin were evaluated with immunohistochemistry. RESULTS: The expression levels of ßIII-tubulin and survivin in the study group were significantly higher compared with those in the control group (p<0.01). Spearman's correlation analysis suggested that the expression of ßIII-tubulin was also correlated with that of survivin (p<0.05), but no correlation existed between the expression levels of ßIII-tubulin and survivin with age, gender and pathological tumor type. The complete response (CR) + partial response (PR) rates were 54.10%. Patients with ßIII-tubulin and/or survivin overexpression were less responsive to docetaxel-based therapy (p<0.05) and also had shorter median time to progression and 1- and 2-year survival rates (p<0.05). CONCLUSION: Overexpression of ßIII-tubulin and survivin in gastric cancer cells was associated with resistance to docetaxel-based chemotherapy in patients with advanced gastric cancer.

Expression of ß-tubulin III and survivin in advance stage breast cancer correlates with chemotherapeutic effects of docetaxel.

AIMS: To investigate the relationship between the expression of ß-tubulin III and survivin in advanced breast cancers and chemotherapeutic effects of docetaxel. METHODS: Clinical pathological data of 74 patients with advanced breast cancer were retrospectively analyzed after docetaxel chemotherapy. Expression of ß-tubulin III and survivin was assessed by immunohistochemistry and analyzed with reference to therapeutical and adverse effects of docetaxel. RESULTS: The positive expression rate of ß-tubulin III was 38.1% (32/84), while that of survivin was 76.2% (64/84). The effective rate (complete response + partial response) was 52.4%. That for patients with the positive expression of ß-tubulin III or/and survivin was significantly lower than for those with negative expression (P<0.05). There were significant differences in the non-progression of median diseases, 1-year and 2-year survival rates of between the patients with positive and negative expression (P<0.05). The main side effects were myelosuppression, alimentary canal response and alopecia, no differences being observed between groups. CONCLUSIONS: The combined detection of ß-tubulin III and survivin is a predictive index for chemotherapy effects of docetaxel in metastatic breast cancer.

[Expression and methylated regulation of HERVWE1 in placenta of monozygotic discordant twins].

OBJECTIVE: To explore the HERVWE1 gene expression in the placentas of discordant monozygotic twins and identify its regulation by methylation. METHODS: Fetuses from 21 pairs of monozygotic discordant twins were marked as "smaller" or "larger" according to birth weight. Placental HERVWE1 mRNA and protein expression profiles were analyzed by quantitative reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC) stain. Methylation profiles of the HERVWE1 promoter region were analyzed by COBRA, MSP-PCR and pyrosequencing assay. RESULTS: In discordant twins group, the mean methylation level of the HERVWE1 promoter region decreased in smaller fetuses (P < 0.05). And there were increased mRNA and protein levels of HERVWE1 in smaller fetuses versus larger counterparts (P < 0.05). CONCLUSION: In discordant monozygotic twins, the HERVWE1 expression is higher in smaller fetuses and lower in larger counterparts. Methylation of HERVWE1 gene promoter region may participate in the regulation of HERVWE1 gene expression in twins.

Intrapleural chemo- and hyperthermotherapies for malignant pleural effusion: a randomized prospective study.

OBJECTIVE: The current prospective randomized study was designed to evaluate the safety and efficacy of combined intrapleural cisplatin and OK-432 (picibanil) plus hyperthermotherapy in patients with malignant pleural effusion (MPE). METHODS: A total of 358 patients with MPE due to end-stage malignancies were enrolled and randomly divided into two groups, A and B: the intrapleural combination of cisplatin and OK-432 with hyperthermotherapy (n = 179) or without hyperthermotherapy (n = 179), respectively. Mild toxicities such as nausea, vomiting or anorexia, bone marrow depression, and pyrexia were similar in both groups. RESULT: Patients in Group A (with hyperthermotherapy) showed a significantly higher overall response (93.4%) compared to those in Group B (79.8%, χ(2) = 43.11, p < .05). The median survival time for patients in Group A and Group B were 8.9 and 6.2 months, respectively (p > .05). After treatment, the quality of life scores were significantly increased in both groups as compared to prior treatment (p < .05). CONCLUSION: In conclusion, our study suggests that combined intrapleural cisplatin and OK-432 followed by hyperthermotherapy are more effective in the control of MPE and improve patients' quality of life.

VEGF-modified human embryonic mesenchymal stem cell implantation enhances protection against cisplatin-induced acute kidney injury.

The implantation of mesenchymal stem cells (MSC) has been reported as a new technique to restore renal tubular structure and improve renal function in acute kidney injury (AKI). Vascular endothelial growth factor (VEGF) plays an important role in the renoprotective function of MSC. Whether upregulation of VEGF by a combination of MSC and VEGF gene transfer could enhance the protective effect of MSC in AKI is not clear. We investigated the effects of VEGF-modified human embryonic MSC (VEGF-hMSC) in healing cisplatin-injured renal tubular epithelial cells (TCMK-1) with a coculture system. We found that TCMK-1 viability declined 3 days after cisplatin pretreatment and that coculture with VEGF-hMSC enhanced cell protection via mitogenic and antiapoptotic actions. In addition, administration of VEGF-hMSC in a nude mouse model of cisplatin-induced kidney injury offered better protective effects on renal function, tubular structure, and survival as represented by increased cell proliferation, decreased cellular apoptosis, and improved peritubular capillary density. These data suggest that VEGF-modified hMSC implantation could provide advanced benefits in the protection against AKI by increasing antiapoptosis effects and improving microcirculation and cell proliferation.

[Construction and identification of a RNA interference plasmid for rat BNIP3 gene].

OBJECTIVE: To construct a RNA interfering plasmid targeting rat Bcl-2/E1B-19K-interacting protein 3 (BNIP3) and assess its effect on exogenous BNIP3 expression in HEK293 cells. METHODS: The miRNA sequences were designed using Invitrogen BLOCK-iT RNAi Designer and synthesized into double-strand oligonucleotides, which were cloned into the pcDNATM6.2-GW/EmGFP-miR vector, followed by transformation of the product into competent Top10 E. coli cells. After expansion of the transformed bacteria, the plasmid was extracted and sequenced before its co-transfection with pEGFP-C3- rBNIP3 plasmid into HEK293 cells. The interference effect of the constructed plasmid on BNIP3 mRNA and protein expression were detected by real-time PCR and Western blotting. RESULTS: The sequencing result indicated that the interfering plasmid targeting rat BNIP3 was constructed correctly. After transfection into HEK293 cells, the interfering plasmid significantly inhibited exogenous BNIP3 mRNA and protein expressions. CONCLUSION: The RNA interfering plasmid targeting rat BNIP3 has been constructed successfully, which provides a useful tool for studying the function of BNIP3.

Changes of androgen receptor and insulin-like growth factor-1 in LNCaP prostate cancer cells treated with sex hormones and flutamide.

Changes of androgen receptor (AR) and insulin-like growth factor-1 (IGF-1) were investigated in LNCaP cells treated with 5α-dihydrotestosterone (DHT), estrone and flutamide. Real-time PCR, immunocytochemistry and western blotting were used to detect the expression of AR and IGF-1 in the presence or absence of various kinase inhibitors. Low concentrations of DHT, estrone and flutamide increased the expression of AR and IGF-1, especially estrone, with concentration and time dependence. With DHT and flutamide, there was a significant alteration in AR expression (p<0.001). The results indicated expression of AR and IGF-1 genes to be influenced by DHT, estrone and flutamide in LNCaP cells, regulated by multiple signal pathways.

[Successful preimplantation genetic diagnosis for beta-thalassemia using multiplex nested polymerase chain reaction].

OBJECTIVE: To develop single-cell multiplex nested polymerase chain reaction (PCR) assays for preimplantation genetic diagnosis (PGD) in couples at risk of having child with beta-thalassemia. METHODS: Primers were designed and synthesized according to the documented mutation sites common among Chinese. Venous blood was collected from 4 pairs of husband and wife, all heterozygotes for beta-thalassemia, and underwent multiple nested PCR. Intraooplasmic sperm injection and mechanical bio psy was used to obtain single blastomere. Multiplex nested PCR was used to detect the CD41-42 mutation and the closely linked polymorphic marker, HumTHO1 gene or CD41-42, CD41-28, IVSII654 mutation and HumTHO1 gene in the single blastomeres from four clinical PGD cycles. The normal embryos with high scores capable of continuing to divide were transplanted into the uteri. The process of gestation was observed. RESULTS: 200 lymphocytes were amplified by nested PCR. The average amplification rate of the most common 16 beta-thalassemia mutations in Chinese population was 91.3% and the average rate of allele drop out for different sites was 17.0% without differences between any 2 sites. During the 4 PGD cycles 33 embryos underwent bioassay with a success rate of 100%. 33 blastomeres were obtained to undergo PCR, of which 30 were successfully amplified with an amplification rate of 90.9%. Explicit diagnosis was obtained in 26 of the 30 embryos: 7 normal homozygotes, 11 heterozygotes, and 8 abnormal or complex heterozygotes. One or more embryos were transferred back into the uteri of the 4 women and clinical pregnancy occurred in one woman. Five weeks after the implantation B-mode ultrasonography showed monocyesis, and in the 17th week of gestational period paracentesis of cord blood showed normal homozygote. At last a normal female infant confirming the PGD result had been born, which was the first reported unaffected pregnancy resulting from PGD using multiplex nested PCR for couples as beta-thalassemia gene carriers. The results of diagnosis for embryo all corresponded to those for blastomere. The average ADO rate of blastomere was 13.3% (4/30). CONCLUSION: PGD using multiplex nested PCR, as an alternative to prenatal diagnosis, is a reliable and effective way to help couples-carriers of pathogenetic genes to get a healthy baby.

The effects of GM1 and bFGF synergistically inducing adult rat bone marrow stromal cells to form neural progenitor cells and their differentiation.

OBJECTIVE: To investigate the effects of GM1 on inducing adult rat bone marrow stromal cells (MSCs) to form neural progenitor cells and their differentiation. METHODS: Purified MSCs were induced by different components of basic fibroblast growth factor (bFGF) alone, GM1 alone or combination of bFGF with GM1. After 3 days' incubation, fibronectin and collagen I were detected with immunocytochemistry, and nestin was detected with immunofluorescence. Neuron-specific enolase (NSE), glial fibrillary acidic protein (GFAP) and galactose cerebroside (GalC) were detected with immunocytochemistry after 7 days' incubation. RESULTS: After induction with bFGF alone or combination of bFGF and GM1, some MSCs exhibited the phenotypes of neural progenitor cells, and then neurons and astrocytes. In these two groups, the positive cells for fibronectin and collagen I decreased markedly after 3 days' induction. At the same time, the positive cells for nestin increased markedly. After 7 days' induction, NSE and GFAP-positive cells increased significantly. Furthermore, the addition of bFGF and GM1 caused the maximal variation. However, addition of GM1 alone had no inductive effects. CONCLUSIONS: Combination of bFGF with GM1 may synergistically promote the transformation of MSCs and differentiation into neurons and astrocyte-like cells. The results suggest a promising route for the application of MSCs.

Protection of potassium channel inhibitors against hypoxia/reoxygenation-induced death of cultured hippocampal neurons.

OBJECTIVE: To investigate the effects of potassium channel inhibitors on hypoxia/reoxygenation-induced death of cultured hippocampal neurons. METHODS: Cultured 8 d in vitro, hippocampal neurons were exposed to hypoxia (in mixture of 95% N2 and 5% CO2) for 6 h, and then reoxygenated till the 72nd hour. Different potassium channel inhibitors were applied to the culture solution separately after reoxygenation. Neuron death was analyzed with cell counting and MTT assay. RESULTS: Hypoxia/reoxygenation procedure induced a delayed death of cultured hippocampal neurons. Application of tetraethylammonium (TEA) offered concentration-dependent protection of the neurons against death. Selective high-conductance calcium-activated potassium channel (BK) inhibitor iberiotoxin (IbTX) showed significant neuron protection (P<0.001). However, A-type potassium channel inhibitor 4-aminopyridine presented no protection against neuron death (P>0.05). CONCLUSION: Following hypoxia/reoxygenation, enhanced activity of potassium channel, especially BK channel, may induce neuron death.