Response of human embryonic stem cell-derived mesenchymal stem cells to osteogenic factors and architectures of materials during in vitro osteogenesis

One of the major challenges to the application of human embryonic stem cells (hESCs) to the repair of defective tissues is the directed differentiation of cells into specific lineages to avoid the formation of inferior heterogeneous tissues. To accomplish this goal, the lineage-specific stem cell population needs to be isolated and optimal differentiation conditions need to be defined. In this study, homogenous hESC-derived mesenchymal stem cells (hESC-MSCs) were generated and used to construct bone tissue. The effect of osteogenic factors, including dexamethasone (Dex) and bone morphogenetic protein-7 (BMP-7), on the osteogenesis of hESC-MSCs was investigated. It was found that BMP-7 itself had little effect on the in vitro osteogenic differentiation of hESC-MSCs; however, there was a synergic effect between BMP-7 and Dex in promoting osteogenesis. The effect of osteoconductive nanofibrous polylactic acid material on osteogenesis of hESC-MSCs was also investigated. It was found that the nanofibrous matrix architecture promoted alkaline phosphatase activity and calcium deposition of cells cultured under osteogenic conditions. Based on these findings, the hESC-MSCs were cultured on three-dimensional nanofibrous scaffolds in combination with Dex and BMP-7 stimulation in vitro to generate bone-like tissues. After 6 weeks of culture, highly mineralized tissues developed with specific bone marker genes expressed. These data illustrate the promise of hESC-MSCs for bone regeneration under optimal conditions.

Spontaneous formation of temperature-responsive assemblies by molecular recognition of a β-cyclodextrin containing block copolymer and poly(N-isopropylacrylamide)

We report the construction of novel temperature-responsive assemblies based on a double hydrophilic block copolymer (consisting of a PEG block and a β-cyclodextrin-containing block, PEG-b-PCD) and poly(N-isopropylacrylamide) (PNIPAm). Thus formed nano-assemblies exhibit a spherical morphology and have a temperature-responsive loose core. The driving force for the formation of these assemblies was found to be the inclusion complexation interaction between the hydrophobic cavity of β-cyclodextrin and the isopropyl group of PNIPAm. The particle size of these assemblies changed reversibly in response to the external temperature change. The particle size also changed with the PNIPAm/PEG-b-PCD weight ratio. A model hydrophobic drug (indomethacin) was loaded into these assemblies with a high efficiency. An in vitro release study showed that the payload could be released in a sustained manner after an initial burst release. The release rate could be switched between high and low in an ON/OFF fashion by temperature. These results demonstrate that the nano-assemblies have high potential for applications in controlled drug delivery and biomedicine when temperature responsiveness is desired.

Novel antibacterial nanofibrous PLLA scaffolds

In order to achieve high local bioactivity and low systemic side effects of antibiotics in the treatment of dental, periodontal and bone infections, a localized and temporally controlled delivery system is crucial. In this study, a three-dimensional (3-D) porous tissue engineering scaffold was developed with the ability to release antibiotics in a controlled fashion for long-term inhibition of bacterial growth. The highly soluble antibiotic drug, doxycycline (DOXY), was successfully incorporated into PLGA nanospheres using a modified water-in-oil-in-oil (w/o/o) emulsion method. The PLGA nanospheres (NS) were then incorporated into prefabricated nanofibrous PLLA scaffolds with a well interconnected macro-porous structure. The release kinetics of DOXY from four different PLGA NS formulations on a PLLA scaffold was investigated. DOXY could be released from the NS-scaffolds in a locally and temporally controlled manner. The DOXY release is controlled by DOXY diffusion out of the NS and is strongly dependent upon the physical and chemical properties of the PLGA. While PLGA50-6.5K, PLGA50-64K, and PLGA75-113K NS-scaffolds discharge DOXY rapidly with a high initial burst release, PLGA85-142K NS-scaffold can extend the release of DOXY to longer than 6weeks with a low initial burst release. Compared to NS alone, the NS incorporated on a 3-D scaffold had significantly reduced the initial burst release. In vitro antibacterial tests of PLGA85 NS-scaffold demonstrated its ability to inhibit common bacterial growth (S. aureus and E. coli) for a prolonged duration. The successful incorporation of DOXY onto 3-D scaffolds and its controlled release from scaffolds extends the usage of nano-fibrous scaffolds from the delivery of large molecules such as growth factors to the delivery of small hydrophilic drugs, allowing for a broader application and a more complex tissue engineering strategy.

AFM and fluorescence imaging of nanomechanical response in periodontal ligament cells

Most biologists think that AFM has only a limited use in biological research due to its inability to study other than surface structures. Therefore, a BIO-AFM system has been developed to combine both AFM imaging and fluorescence detection, which acts as a powerful tool for a better understanding of dynamic cell processes. In this study, based on a custom-made BIO-AFM system, the elasticity and ultrastructure of living periodontal ligament cells (PDLCs) were investigated. The cantilever probe with a micron-sized bead was used to exert nano-loading force onto the PDLCs. The related signal of NO was then recorded simultaneously. The results show that PDLCs hold strong networks of stress fibers as well as high elastic modulus value, exhibiting the ability for better counteracting the external forces. In the mechano-transduction studies, an initial increase and subsequent drop in intracellular NO response was found. Furthermore, NO may diffuse from a stimulated cell to adjacent cells. In conclusion, our single-cell nano-mechanical study provides a significant advancement in elucidating the magnitude, location, time scale, and biomolecular mechanisms underlying cell mechano-transduction.

TRAF6 polymorphisms not associated with the susceptibility to and severity of sepsis in a Chinese population

BACKGROUND

The tumor necrosis factor recepter associated factor (TRAF) 6 is an important intracellular adapter protein that plays a pivotal role in activating multiple inflammatory and immune related processes induced by cytokines. TRAF6 represents a strong candidate susceptibility factor for sepsis. We investigated whether polymorphisms at the TRAF6 gene are associated with the susceptibility to and severity of sepsis.

METHODS

A hospital-based case-control study was conducted with 255 patients with sepsis and 260 controls who were recruited from Zhengzhou, China. Haplotype tagging single nucleotide polymorphisms (htSNPs) were selected from the HapMap database and genotyped using the SNPstream genotyping platform. The associations with the susceptibility and disease severity of sepsis were estimated by logistic regression, and adjusted for age, sex, smoking, drinking, chronic diseases status, APACHEII score and critical illness status.

RESULTS

A total of 13 TRAF6 SNPs were tagged by 7 htSNPs. Five htSNPs (rs5030490, rs5030411, rs5030416, rs5030445 and rs3740961) were genotyped in the case control study. Genotype frequencies of the htSNPs were conformed to the Hardy-Weinberg equilibrium in both patients and controls. No significant association was found between the 5 htSNPs and the susceptibility to and severity of sepsis. Compared with the main haplotype -11120A/-10688T/-9423A/805G/12967G, no certain haplotype was associated with the significantly susceptibility to or severity of sepsis.

CONCLUSION

TRAF6 gene polymorphisms might not play a major role in mediating the susceptibility to and severity of sepsis in the Chinese population. A larger population-based case-control study is warranted.

[Association of glucocorticoid receptor gene polymorphism with myasthenia gravis]

OBJECTIVE

To investigate the association of two glucocorticoid receptor (GR) polymorphisms (BclI, ER22/23EK) with Myasthenia Gravis (MG).

METHODS

The genotypes of GR in 61 MG patients (MGG) and 57 age and gender-matched healthy controls (HCG) were determined by polymerase chain reaction and nucleotide sequence determination.

RESULTS

The frequencies of three genotypes (GG, CG, CC) in BclIwere 3.3%, 34.4%, 62.3% in MGG and 3.5%, 38.6%, 57.9%in HCG respectively. The difference in the distribution of genotypes between MGG and HCG was statistically insignificant (P = 0.887). The frequencies of G and C allele were 20.5% vs 79.5 %in MGG, and 22.8% vs 77.2% in HCG. The difference in the distribution of alleles between MGG and HCG was statistically insignificant (P = 0.968). The genotype frequencies in two groups were both in Hardy-Weinberg equilibrium (P > 0.05). The genotypes of ER22/23EK in MGG and HCG were all GG and no mutation was detected.

CONCLUSION

BclI and ER22/23EK polymorphisms of GR have no definite relationship with the risk of MG.

Osteogenic differentiation of human amniotic fluid-derived stem cells induced by bone morphogenetic protein-7 and enhanced by nanofibrous scaffolds

Amniotic fluid-derived stem cells (AFSCs) are becoming an important source of cells for regenerative medicine given their apparent advantages of accessibility, renewal capacity and multipotentiality. In the intermediate stage between the embryonic stem cells (ESCs) and adult stem cells, AFSCs may have a distinct mechanism to choose their fate. Unfortunately, until now, little is known about how bone morphogenetic proteins (BMPs) control the osteoblastic differentiation of AFSCs, especially on 3D scaffolds. Our research shows that human AFSCs (hAFSCs) can be induced for osteoblastic differentiation by rhBMP-7, and hAFSCs respond to rhBMP-7 more strongly than human mesenchymal stem cells (hMSCs). As synthetic ECM, scaffolds play a central role in tissue engineering. The hAFSCs, on the nanofibrous scaffolds (NF scaffolds) with morphology similar to that of natural collagen fibers, showed significantly enhanced alkaline phosphatase (ALP) activity, calcium content, von Kossa staining and the expression of osteogenic genes than those on the traditional scaffolds, i.e. solid walled scaffolds. The data on the bone formation in vivo presented further evidence that biomimetic NF scaffolds provided hAFSCs a more favorable synthetic ECM, and thus, facilitated the osteogenic differentiation of hAFSCs. The relative strong responsiveness to rhBMP-7 makes hAFSCs promising in bone regeneration. The synthetic NF scaffolds, which mimic the morphology of natural collagen fibers, enhanced the osteoblastic differentiation of hAFSCs in vitro and bone formation in vivo.

Percutaneous Biliary Stent Placement in Palliation of Malignant Bile Duct Obstruction

BACKGROUND

To summarize the experiences with the technique of percutaneous biliary stent placement for treatment of malignant biliary obstruction in patients with different types of biliary obstruction.

METHODS

Percutaneous biliary stent placement was performed in 126 patients with malignant biliary obstruction. The etiology included 56 cases of cholangiocarcinoma, 28 cases of pancreatic cancer, 12 cases of ampullary carcinoma, 10 cases of primary hepatic carcinoma, 8 cases of gastric cancer metastasis, 6 cases of gallbladder carcinoma, and 6 cases of liver metastasis of colon cancer. The obstructed lesion predominantly involved the common bile duct in 42 patients, common hepatic duct in 39 patients, and hilar bile duct in 45 patients. When the bile duct was punctured successfully under fluoroscopy, the guide wire was explored to across the obstruction segment under the assistant of catheter, then the stent was inserted along the super-slippery guide wire. In patients with hilar hepatic duct lesions involving both left and right hepatic ducts, the both ducts were punctured and bilateral stenting was performed. A 8.5 F internal/external drainage catheter was inserted. The liver function test and ultrasound were performed one week after the procedure to observe the decrease of bilirubin and alleviation of biliary obstruction.

RESULTS

A total of 166 stents were implanted in 126 patients. In the 42 patients with common bile duct obstruction, each patient was implanted one stent. In the 39 patients with common hepatic duct obstruction, each patient was impanted one stent. In the 45 patients with hilur bile duct obstruction, 38 patients were placed 2 stents, one patient was placed with 3 stents, and the rest were placed with one stent. The serum total bilirubin decreased from 309.2 ± 158.3 µmol/L before the procedure to148.5 ± 98.0 µmol/L one week after the procedure (P < 0.001). Alkaline phosphatase and alanine aminotransferase significantly decreased (P < 0.001). Five cases died within 1 month (4%) after the procedure. Complications occurred in 9 cases (7.1%). Six patients underwent combined duodenal self-expandable metal stent placement successfully.

CONCLUSIONS

The percutaneous biliary stent placement is a safe and effective palliative therapy for malignant biliary obstruction by improving liver function and 1ife quality.

Chondrogenic and osteogenic differentiations of human bone marrow-derived mesenchymal stem cells on a nanofibrous scaffold with designed pore network

The utilization of 3D scaffolds and stem cells is a promising approach to solve the problem of bone and cartilage tissue shortage and to construct osteochondral (cartilage/bone composite) tissues. In this study, 3D highly porous nanofibrous (NF) poly(L-lactic acid) (PLLA) scaffolds fabricated using a phase separation technique were seeded with multi-potent human bone marrow-derived mesenchymal stem cells (hMSCs) and the constructs were induced along osteogenic and chondrogenic development routes in vitro. Histological analysis and calcium content quantification showed that NF scaffolds supported in vitro bone differentiation. SEM observation showed an altered shape for cells cultured on an NF matrix compared with those on smooth films. Consistent with the morphological change, the gene expression of early chondrogenic commitment marker Sox-9 was enhanced on the NF matrix. NF scaffolds were then used to support long-term in vitro 3D cartilaginous development. It was found that in the presence of TGF-beta1, cartilage tissue developed on PLLA NF scaffolds, with the cartilage-specific gene expressed, glycosaminoglycan and type II collagen accumulated, and typical cartilage morphology formed. These findings suggest that NF scaffolds can support both bone and cartilage development and are excellent candidate scaffolds for osteochondral defect repair.

Detection of a CD4+CD8-CD3- cell subpopulation during the differentiation of cord blood CD34+ cells into T cells in vitro

INTRODUCTION

Umbilical cord blood contains relatively abundant primitive CD34(+) hematopoietic progenitor cells which can differentiate into T lymphocytes ex vivo

MATERIALS AND METHODS

In this study, thymic stromal cells (TSCs) were isolated from aborted fetuses and a monolayer culture system was established. Highly-purified CD34(+) cells from umbilical cord blood were cultured on the TSCs after limiting-dilution. The cells were then harvested and evaluated for CD4, CD8, and CD3 expression at different time points. CD4(+)CD8(-)CD3(-) lymphoid progenitor cells that could differentiate into mature T lymphocytes were observed after 15 days when a cocktail of cytokines, including Flt-3 ligand, stem cell factor, interleukin (IL)-12, and IL-2, was added.

RESULTS

These results thus show that CD4(+)CD8(-)CD3(-) cells can be derived from CD34(+) cells in vitro when cultured on TSCs.

CONCLUSIONS

We showed that CD4(+)CD8(-)CD3(-) cells can be derived from highly purified CD34(+) cells on TSCs during T-cell lymphopoiesis in vitro.

Discovery and identification of potential biomarkers of pediatric acute lymphoblastic leukemia

Background

Acute lymphoblastic leukemia (ALL) is a common form of cancer in children. Currently, bone marrow biopsy is used for diagnosis. Noninvasive biomarkers for the early diagnosis of pediatric ALL are urgently needed. The aim of this study was to discover potential protein biomarkers for pediatric ALL.

Methods

Ninety-four pediatric ALL patients and 84 controls were randomly divided into a "training" set (45 ALL patients, 34 healthy controls) and a test set (49 ALL patients, 30 healthy controls and 30 pediatric acute myeloid leukemia (AML) patients). Serum proteomic profiles were measured using surface-enhanced laser desorption/ionization-time-of-flight mass spectroscopy (SELDI-TOF-MS). A classification model was established by Biomarker Pattern Software (BPS). Candidate protein biomarkers were purified by HPLC, identified by LC-MS/MS and validated using ProteinChip immunoassays.

Results

A total of 7 protein peaks (9290 m/z, 7769 m/z, 15110 m/z, 7564 m/z, 4469 m/z, 8937 m/z, 8137 m/z) were found with differential expression levels in the sera of pediatric ALL patients and controls using SELDI-TOF-MS and then analyzed by BPS to construct a classification model in the "training" set. The sensitivity and specificity of the model were found to be 91.8%, and 90.0%, respectively, in the test set. Two candidate protein peaks (7769 and 9290 m/z) were found to be down-regulated in ALL patients, where these were identified as platelet factor 4 (PF4) and pro-platelet basic protein precursor (PBP). Two other candidate protein peaks (8137 and 8937 m/z) were found up-regulated in the sera of ALL patients, and these were identified as fragments of the complement component 3a (C3a).

Conclusion

Platelet factor (PF4), connective tissue activating peptide III (CTAP-III) and two fragments of C3a may be potential protein biomarkers of pediatric ALL and used to distinguish pediatric ALL patients from healthy controls and pediatric AML patients. Further studies with additional populations or using pre-diagnostic sera are needed to confirm the importance of these findings as diagnostic markers of pediatric ALL.

Structural characterization and in vitro antitumor activity of a novel polysaccharide isolated from the fruiting bodies of Pleurotus ostreatus

A novel water-soluble polysaccharide (POPS-1) was obtained from the fruiting bodies of Pleurotus ostreatus by hot water extraction, ethanol precipitation, and fractionated by DEAE-cellulose ion exchange chromatography and sepharose CL-6B gel filtration chromatography using an ATKA explore 100 purifier. The structure characterization and antitumor activity of the POPS-1 were evaluated in this paper. According to GC analysis, HPGPC, FT-IR, partial acid hydrolysis, periodate oxidation and Smith degradation, methylation and GC-MS analysis, the results indicate POPS-1 (M(w)=31 kDa) was composed of Man; Gal; Glc with a molar ratio of 1:2.1:7.9, it had a backbone of beta-(1-->3)-linked glucose residues, which occasionally branches at O-6. The branches were composed of (1-->3)-linked Glc, (1-->4)-linked Gal, (1-->4)-linked Man, and terminated with Glc and Gal residues. Cytotoxicity assay showed POPS-1 presented significantly higher antitumor activity against Hela tumor cell in vitro, in a dose-dependent manner, and exhibited significantly lower cytotoxicity to human embryo kidney 293T cells than Hela tumor cells compared with 5-Fu. The results suggest POPS-1 may be considered as a potential candidate for developing a novel low toxicity antitumor agent.

A modified percutaneous transhepatic variceal embolization with 2-octyl cyanoacrylate versus endoscopic ligation in esophageal variceal bleeding management: randomized controlled trial

BACKGROUND

Conventional percutaneous transhepatic varices embolization (PTVE) has rarely been used in recent years due to high rates of variceal recurrence and rebleeding. Herein we report a modified PTVE with 2-octyl cyanoacrylate (2-OCA) in which the whole lower esophageal and peri or para-esophageal varices, the submucosal varices, and the advertitial plexus of the cardia and fundus were sufficiently obliterated. We compared this PTVE with endoscopic band ligation (EVL) in the treatment of esophageal variceal bleeding.

METHODS

In this prospective randomized controlled trial, cirrhotic patients with acute or recent esophageal variceal bleeding were assigned randomly to PTVE (52 patients) or EVL (50 patients) groups. Upper gastrointestinal (UGI) rebleeding, esophageal variceal rebleeding, and survival were followed-up. Computerized tomography (CT) scanning and portal venography were used to observe 2-OCA distribution.

RESULTS

During the follow-up period (median 24 and 25 months in the PTVE and EVL groups, respectively) UGI rebleeding developed in eight patients in the PTVE group and 21 patients in EVL group (P = 0.004). Recurrent bleeding from esophageal varices occurred in three patients in the PTVE group and twelve in the EVL group (P = 0.012, relative risk 0.24, 95% confidence interval 0.05-0.74). Multivariate Cox analysis indicated that the treatment was the only factor predictive of rebleeding. A Kaplan-Meier curve showed there was no significant difference between survival in the two groups (P = 0.054).

CONCLUSIONS

With the whole lower esophageal and peri or para-esophageal varices, the submucosal varices, and the adventitial plexus of the cardia and fundus sufficiently obliterated by 2-OCA, this modified PTVE was more effective than EVL in the management of esophageal varices recurrence and rebleeding. Survival in these two groups was not significantly different, however.

The correlation between cotransplantation of mesenchymal stem cells and higher recurrence rate in hematologic malignancy patients: outcome of a pilot clinical study

In this open-label randomized clinical trial, HLA-identical sibling-matched hematopoietic stem cells (HSC) were transplanted (non-MSCs group, n=15) or cotransplanted with mesenchymal stem cells (MSCs) (MSCs group, n=10) in hematologic malignancy patients. The median number of MSCs infused was 3.4 x 10(5) kg(-1) (range, 0.3-15.3 x 10(5) kg(-1)). MSCs infusions were well tolerated. The median time to neutrophil engraftment (absolute neutrophil count >0.5 x 10(9) l(-1)) was 16 days for MSCs group and 15 days for non-MSCs group. The median time to platelet engraftment (platelet count >50 x 10(9) l(-1)) was 30 and 27 days, respectively. Grades II-IV acute graft-versus-host disease (GVHD) was observed respectively, in one (11.1%) and eight (53.3%) evaluable patients. Chronic GVHD was found in one (14.3%) and four (28.6%) evaluable patients. The number of patients who relapsed were six (60.0%) and three (20.0%), and the 3-year disease-free survivals were 30.0 and 66.7%, respectively. Thus cotransplantation of MSCs and HSCs may prevent GVHD, but the relapse rate is obviously higher than the control group. We conclude that use of MSCs must be handled with extreme caution before a large-scale clinical trial is performed.

Proteomic profiling of hepatitis B virus-related hepatocellular carcinoma in China: a SELDI-TOF-MS study

Hepatocellular carcinoma (HCC) is one of the most common malignancies with high mortality, but its underlying molecular mechanisms remain not well understood. High-throughput, proteomic techniques targeting unique biological molecules may provide novel insights into HCC pathogenesis and prognosis. In this study, we systemically investigated tissue biomarkers of HCC by using surface-enhanced laser desorption and ionization time-of-flight mass spectrometry (SELDI-TOF-MS) technique. Proteomic spectra were generated from fresh tissues (26 HCC and 18 control cirrhotic liver) and analyzed by using Biomarker Wizard System. A total of 16 differential proteomic peaks were detected between HCC and cirrhotic liver tissues, and 11 between moderately and highly differentiated HCCs. The expression pattern of one proteomic peak was validated by immunohistochemistry. These molecules are potential candidate biomarkers for early diagnosis of and targeted therapy for HCC.

[Percutaneous transhepatic varices embolization with cyanoacrylate in the treatment of varices]

OBJECTIVE

To test the safety and validity of percutaneous transhepatic variceal embolization (PTVE) with tissue adhesive cyanoacrylate.

METHODS

PTVE with cyanoacrylate was performed on 92 patients with gastroesophageal varices, 53 males and 39 females, aged 62.5 (7-84): cyanoacrylate was injected into the varices and the afferent veins. Endoscopy and CT were performed to evaluate the embolization.

RESULTS

PTVE was successfully completed in 89 of the 92 patients with a technical success rate of 96.7%, and 3 patients died within 1 month. Among the other 86 patients 3 types of cyanoacrylate embolization were achieved: embolization of coronary vein, vessels around gastric fundus, and variceal lower esophagus veins in 40 patients, embolization of coronary vein, gastric fundus and pericardial varices in 33 patients, and embolization of sole gastric coronary vein stem in 13 patients. Acute variceal bleeding in 18 patients was immediately arrested after the procedure, with an acute bleeding control rate of 100%. Eighty-six patients were followed up for 31.5 (6-52) months. The general variceal recurrence rate was 14.1% (10/71), and the variceal recurrence rate of the coronary vein embolization group was 100% (2/2), significantly higher than those of the groups of esophagus and fundus embolization and gastric fundus and cardia varices embolization [7.5% (3/40) and 17.2% (5/29) respectively, P = 0.006]. The general rebleeding rate was 16.3% (14/86), and the rebleeding rates of the group of coronary vein embolization was 69.2% (9/13), significantly higher than those of the groups of esophagus and fundus embolization and gastric fundus and cardia varices embolization [7.5% (3/40) and 15. 2% (5/33) respectively, P = 0.0092]. No obvious ectopic embolization was found. The mortality was 24.7% (22/89). The cause of rebleeding in coronary vein embolization was mainly recurrent variceal bleeding, whereas that in the group of fundus and esophagus variceal embolization was mainly hypertensive gastropathy.

CONCLUSION

PTVE with cyanoacrylate is safe and effective for the obliteration of gastroesophageal varices in cirrhotic patients.

[Treatment of esophageal varicose bleeding by percutaneous transhepatic varices obliteration and partial spleen embolization]

OBJECTIVE

To study the clinical efficacy of TH glue (cyanoacrylate) obliteration of esophageal varices and partial spleen embolization (PSE) in the treatment of esophageal varices bleeding.

METHODS

TH glue was injected into the gastroesophageal varices and their feeder veins in 84 patients. According to the size of the varices and their blood flow, the TH glue was injected alone or after a steel coil was placed at the ostium of the feeder vein. Sometimes absolute alcohol was also injected into the varices. PSE was performed after the TH glue obliteration in all patients.

RESULTS

(1) The TH glue obliteration was performed on 81 patients with a success rate of 96.4%. Three patients died from the procedure. (2) The left gastric vein coronary, gastric varices, pericardial varices, and lower esophageal veins were obliterated in 38 patients (group 1). Left gastric vein, gastric varices, and pericardial veins were obliterated in 31 patients (group 2). Only the main gastric coronary vein was obliterated in 9 patients (group 3). The disappearance rate of the esophageal varices was 71.1% (27/38), 35.5% (11/31) and 0% (0/9) in the three groups. (3) During a follow-up of 6-49 months, rebleeding occurred in 13 of all 78 (16.7%) patients, and it was 7.9% (3/38), 12.9% (4/31) and 66.7% (6/9) respectively in the three groups.

CONCLUSION

Our results suggest percutaneous transhepatic TH glue obliteration of esophageal varices and PSE are safe and effective in treating gastroesophageal varicose bleeding.

Effects of haplotypes in the interleukin 1beta promoter on lipopolysaccharide-induced interleukin 1beta expression

Previous studies have indicated that there are 3 common haplotypes composed of the -1470, -511, and -31 loci in the interleukin 1beta (IL-1beta) promoter in the Chinese population. The purpose of this study was to investigate the relationship between these haplotypes and lipopolysaccharide (LPS)-stimulated IL-1beta expression by whole blood leukocytes in vitro and to evaluate the effects of these haplotypes on IL-1beta gene transcription. Genomic DNAs were obtained from 105 healthy subjects. The genotypes at the 3 sites of the IL-1beta promoter were determined by restriction fragment length polymorphism analysis. Haplotype frequency was evaluated by using the Arlequin software. Plasma IL-1beta level was measured by enzyme-linked immunosorbent assay. The transcriptional activity of the haplotypes was determined by in vitro reporter gene. The results indicated that after the exposure to LPS, whole blood leukocytes from subjects with the homozygous haplotype -1470G, -511C, and -31T (G-C-T) produced more IL-1beta in vitro than those from subjects with haplotype -1470C, -511T, and -31C (C-T-C) and that the transcriptional activity of the haplotype G-C-T was also higher than that of the haplotype C-T-C. It is suggested that the haplotypes of the IL-1beta promoter influence the expression and transcriptional activity of the IL-1beta gene and that the upregulation of IL-1beta gene expression after LPS exposure in subjects with haplotype G-C-T may be due to an increased transcriptional activity of the haplotype.

Isolation and characterization of a novel lectin from the mushroom Armillaria luteo-virens

From the dried fruiting bodies of the mushroom Armillaria luteo-virens, a dimeric lectin with a molecular mass of 29.4 kDa has been isolated. The purification procedure involved (NH(4))(2)SO(4) precipitation, ion exchange chromatography on DEAE-cellulose, CM-cellulose, and Q-Sepharose, and gel filtration by fast protein liquid chromatography on Superdex 75. The hemagglutinating activity of the lectin could not be inhibited by simple sugars but was inhibited by the polysaccharide inulin. The activity was stable up to 70 degrees C but was acid- and alkali-labile. Salts including FeCl(3), AlCl(3), and ZnCl(2) inhibited the activity whereas MgCl(2), MnCl(2), and CaCl(2) did not. The lectin stimulated mitogenic response of mouse splenocytes with the maximal response achieved by 1microM lectin. Proliferation of tumor cells including MBL2 cells, HeLa cells, and L1210 cells was inhibited by the lectin with an IC(50) of 2.5, 5, and 10 microM, respectively. However, proliferation of HepG2 cells was not affected. The novel aspects of the isolated lectin include a novel N-terminal sequence, fair thermostability, acid stability, and alkali stability, together with potent mitogenic activity toward spleen cells and antiproliferative activity toward tumor cells.

[The correlated research of acute graft versus host disease after allogeneic stem cell transplantation]

OBJECTIVE

To analyze the relationship between the expression of FasL, Perforin and Granzyme B and the development of acute graft versus host disease (aGVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT).

METHODS

The peripheral blood mRNA expression of granzyme B, perforin, fasL from 17 patients after allo-HSCT was detected by competitive quantitative RT-PCR and the relationship between FasL, Granzyme B and Perforin expressions and clinical symptom of aGVHD was analyzed.

RESULTS

The expression level of Granzyme B, Perforin and FasL was 4.6 +/- 0.2, 4.5 +/- 0.1, 1.4 +/- 0.1 before aGVHD occurrence respectively, and was 98.7 +/- 2.5, 91.8 +/- 3.4, 61.5 +/- 2.2, after the occurrence in 14 patients (P < or = 0.05). Over expressions of Granzyme B, Perforin, and FasL during acute GVHD were detected in 13 of 14, 12 of 14, and 12 of 14 patients respectively. The upregulated expressions occurred prior to clinical symptom of aGVHD.

CONCLUSION

The expressions of Granzyme B, Perforin, and FasL were significantly high in patients with acute aGVHD. Monitoring of the expressions, might predict the occurrence of clinical aGVHD and it severity and prognosis.

[Experimental study of T lymphocyte reactivity inhibited by allogeneic bone marrow mesenchymal stem cells]

OBJECTIVE

To address the question whether bone marrow mesenchymal stem cells (MSCs) could lower responsiveness of allogeneic T lymphocytes against alloantigens, and explore a feasible strategy for prevention of graft versus host disease (GVHD) occurred in allogeneic bone marrow transplantation.

METHODS

T cells were co-cultured with (60)Co-irradiated bone marrow MSCs from different individuals. The proliferative activity of T cells and their reactivity to allogeneic cells and ConA were evaluated with (3)H-TdR incorporation assay.

RESULTS

T cells could not be activated upon primary or even secondary exposure to allogeneic MSCs (compared the CPM value of 27,529 +/- 969 of T cell alone with that of primary and secondary exposures to allogeneic MSCs were 9,126 +/- 654 and 13,260 +/- 874, respectively). When MSCs were induced to express HLA-DR, they still could not elicit T cell activation. The proliferation rate of allogenous T cells exposed to MSCs was dramatically declined when T cells from the same donor's MSCs were used as stimulator (CPM value decreased from 45,876 +/- 5285 before coculture to 9850 +/- 1618 after coculture). Furthermore, the results remained unchanged even ConA was added into the culture system.

CONCLUSIONS

Heterogenetic MSCs could suppress T cell activation. MSCs pretreatment might be useful in the prevention of GVHD in HLA-mismatched bone marrow transplantation.

[Expression of topoisomerase III alpha in epithelial ovarian tumors of different types and relation between the expression of topoisomerase III alpha and the clinical pathology of tumor]

OBJECTIVE

To investigate the expression status of topoisomerase IIIa in epithelial ovarian tumor and the relationship between the expression status of topoisomerase IIIa and pathological type and clinical stage of epithelial ovarian carcinoma.

METHODS

Immunohistochemistry was carried out in the samples of ovarian tumor obtained during operation from 169 patients, aged 28 approximately 59, 18 cases with serous cystadenoma, 30 cases with serous borderline cystadenoma, 37 serous cystadenocarcinoma, 10 cases with mucous cystadenoma, 20 mucous borderline cystadenoma, 26 mucous cystadenocarcinoma, 19 cases with endometrial carcinoma of ovary, and 9 cases with clear cell carcinoma.

RESULTS

The expression rate of topoisomerase IIIa was 17.9% in the benign ovarian tumors, 74.0% in the borderline cystadenoma, and 42.7% in the malignant tumors with statistical significance among them (chi(2) = 24.657, P < 0.001). There was no correlation between the expression of topoisomerase IIIa and the clinical stage or pathological grade of the tumors (P = 0.903 and P = 0.844).

CONCLUSION

Topoisomerase IIIa is highly expressed in epithelial ovarian carcinoma, and its expression level is correlated with the character and type of tumor tissues.

[Evaluation of endothelial cells differentiated from mesenchymal stem cells of human bone marrow with Tie-2 monoclonal antibody by immunohistochemistry in vitro]

AIM

To amplify mesenchymal stem cells (MSCs) from human bone marrow (HBM) and to induce MSCs differentiated into endothelial cells (ECs) in vitro, which possibility and conditions were to be discussed.

METHODS

MSCs were separated by gradient centrifugation on Percoll (density 1.073 g/ml) from HBM, and incubated for purification and amplification in DMEM (low glucose) with 10% fetal bovine serum (FBS). MSCs, which their phenotypic characteristics were analyzed by flow cytometry, were incubated for orientation differentiated into ECs in DMEM (high glucose) with 20% FBS and VEGF (10 ng/ml) for about 14 - 21 days. Afterwards, the cells differentiated were evaluated by immunohistochemistry with Tie-2 monoclonal antibody and by transmission electron microscopy (TEM) for observation Weible-palade corpuscle in the cytoplasm.

RESULTS

The quantity of MSCs was increased from 5.0 - 10(5) in the primary culture to 8.0 x 10(12), or to increase 1.6 x 10(7) times after 15 generations incubated. The purity of MSCs was above 95% and 98% homogeneous at passages 2 and 3, respectively. The typical "cobblestone" of these cells presented from MSCs differentiation culture after 14 - 21 days was observed by light microscopy. More than 90% of the cells were positive stain for Tie-2 related antigen by immunohistochemistry assay. The Weible-palade corpuscle, which form is typical morphology of ECs, was also observed by TEM in the cytoplasm.

CONCLUSION

MSCs from HBM has the capability in differentiation into ECs in vitro, which is possible to provide the seed cells for fabrication of tissue-engineering heart valve.

[The effect of MSC on cytokine production by naive T cell differentiated in vitro]

OBJECTIVE

To investigate the effect of mesenchymal stem cell (MSC) on naive T cell and to explore its mechanism of immunoregulation.

METHODS

After culturing for 3 passages, MSC was incubated with naive T cells differentiated from cord blood CD34(+) cells in vitro. Variance of cytokine produced by naive T cell in culture supernatant was analyzed by enzyme-linked immunoassays.

RESULTS

On the 7th day of co-culture, a mild proliferation of T cells in the co-culture group was observed: (9.15 +/- 0.68) x 10(5)/well in MSCs + naive T cells group versus (4.87 +/- 1.33) x 10(5)/well in naive T cells alone group (P < 0.05). IFN-gamma production was lower in MSCs + naive T cells group than that in naive T cells alone group: (1.147 +/- 0.181) pg/ml versus (4.897 +/- 0.189) pg/ml (P < 0.05), but IL-2 production was higher in the co-culture group: (16.141 +/- 2.729) pg/ml versus (2.551 +/- 0.460) pg/ml (P < 0.05). Neither IL-4 nor IL-10 were detected.

CONCLUSIONS

MSC have allogeneic effect on naive T cell, but may suppress alloreactive T lymphocyte and reduce the incidence of GVHD partly by decreased IFN-gamma production. The result may provide new clues for explaining immunoregulatory mechanism of MSC.

[Clinical study on anti-leukemia effect mediated by dentritic cells]

Immunotherapy of tumor is extensively attentioned as an important part of combined therapy of tumor in recent years. Dendritic cell (DC) is the most powerful antigen presenting cell (APC) by now which not only activates auto-immunity to attack tumor cells, but also does help to enhance antitumor effect for allogenic bodies. To explore the feasibility and safety of clinical therapy application of peripheral blood derived DC cultured ex vivo, and analyze the influence of DC-inducing-immunotherapy upon long-term survival of ANLL patients accepted autologous bone marrow transplantation, peripheral blood mononuclear cells (PBMNC) of 13 ANLL patients after autologous bone marrow transplantation were collected by using CS3000Plus. DC immunotherapy was administered after cultivation of PBMNC ex vivo for 2 weeks, desease-free survival time was observed after therapy for long time follow-up. The results showed that no any severe adverse event associated with DC therapy was observed, the survival analysis of Kaplan-Meier suggested that five year survival rate was 75.52% in DC group while 45.71% in non-DC group. DC group surpassed non-DC group in accumulative survival rate. It is concluded that the ex vivo cultivation and clinical therapy application of DC derived from peripheral blood are feasible and safe, DC immunotherapy in patients with acute non-lymphocytic leukemia after autologous bone marrow transplantation prolongs desease-free survival time and enhances long-term survival rate.

[Effect of human bone marrow mesenchymal stem cell on allogeneic T lymphocyte phenotype in vitro]

The purpose was to study the effect of mesenchymal stem cell (MSC) on immune function, and to explore the new strategy to prevent graft versus host disease (GVHD) and host versus graft reaction (HVGR) in allogeneic bone marrow transplantation. MSCs from human bone marrow cells were isolated and cultured. The purity of MSCs were identified with the spindle-fibroblastic morphological characterization by microphotography, and the phenotypes were tested by flow cytometry. MSCs were planted in 6-well plates (8 x 10(4)/well for group A, 4 x 10(4)/well for group B and 2 x 10(4)/well for group C), and cocultured for 7 days with T cell isolated from peripheral blood. Peripheral blood T cells non-cocultured with MSC acted as the control group. CD3, CD4, CD8, and CD25 expressed on T cells were analyzed by flow cytometry after coculture with MSCs for 0, 24, 72 hours and 7 days respectively. The results showed that CD4(+)CD25(+) T cells and CD8(+) T cells of allogeneic T lymphocytes cocultured with bone marrow MSCs (group A and group B) increased obviously as compared with control group (T lymphocytes uncocultured with MSCs), and there were no difference between groups A and B. CD3, CD4, CD8 and CD25 expressed on T cells had no significant difference between experimental groups and control group. The result suggested that CD4(+)CD25(+)-regulatory T cells and CD8(+) T cells were increased apparently when cocultured with allogeneic MSCs. It is concluded that MSCs pretreatment may be useful in the prevention of GVHD and HVGR in allogeneic bone marrow transplantation and provides a new strategy to induce transplantation tolerance.

[Study on single nucleotide polymorphism of TLR4 in Chinese population]

OBJECTIVE

To identify the single nucleotide polymorphisms(SNPs) in the regulatory and coding regions of human Toll-like receptor 4(TLR4) gene and to search for its new genetic makers.

METHODS

The 5' flank region, exons, parts of the introns, as well as 3' flank region of TLR4 gene were sequenced to identify and characterize the SNPs in Chinese population. SNP genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism for 2 highly distributed SNPs.

RESULTS

Five novel SNPs were identified through a 4.98 kb sequencing of TLR4 gene. Among them, three were in 5'flank region, two in 3'UTR. In the sample of Han population from Chongqing, the minor allele frequencies of two highly distributed SNPs were 0.266 and 0.404 respectively.

CONCLUSION

Sampling analysis in Han population of Chongqing showed that the two highly distributed SNPs of TLR4 were common in Chinese population and could be used for genetic marker of TLR4 gene.

[Clinical characteristics of propylthiouracil (PTU) induced antineutrophil cytoplasmic antibodies positive cases; analysis of a case of PTU-induced ANCA positive patients with hyperthyroidism]

OBJECTIVE

To study the clinical characteristics of propylthiouracil (PTU) induced antineutrophil cytoplasmic antibodies (ANCA) positive cases and increase the awareness of PTU induced ANCA positive vasculitis (APV).

METHODS

The clinical data of nine cases with positive ANCA induced by PTU in Peking Union hospital since 2000 were analyzed and literature review was conducted.

RESULTS

(1) Nine patients with hyperthyroidism, at a mean age of 33.1 (16 approximately 51), who were treated with PTU for a mean period of 32.4 months (3 approximately 84); (2) Sera from nine cases were ANCA positive, and autoantibodies from six tested cases could recognize not only MPO, but also PR3, HLE, BPI and LF; (3) Six cases with high titer perinuclear ANGA (pANCA) (> or = 1:1280) were diagnosed APV and all had renal involvement (five confirmed by renal biopsies), three cases with low titer pANCA (< or = 1:320) had little clinical manifestations of vasculitis; (4) Eight patients stopped taking PTU when positive ANCA were noted. One case with APV got remission after stopping PTU, the other three APV were treated with glucocorticosteroid and immunosuppressive agents at meanwhile. Only one patient kept taking PTU for eighteen months without an increased titer of ANCA.

CONCLUSION

PTU could induce production of ANCA. High titer of ANCA might suggest existence of APV and the titer would be associated with status of APV. Early withdrawal of PTU and administration of glucocorticosteroid and immunosuppressive agents based on renal pathology will greatly improve the prognosis.

[Effect of insulin, cAMP, and dexamethasone on phosphoenolpyruvate carboxykinase gene promoter in vitro]

OBJECTIVE

To study the effect of insulin, cyclic adenosine monophosphate (cAMP), and dexamethasone (DEX) on 550 bp (-600 -/+ 69) fragment of phosphoenolpyruvate carboxykinase (PEPCK) gene promoter by reporter gene.

METHODS

The recombinant pGL2-PEPCK-Luc and the control plasmid pSV-beta-Galactosidase were co-transfected to rat hepatoma cell line (CBRH7919) by lipofectin. By measuring luciferase activity, we evaluated in vitro regulation of PEPCK gene promoter on reporter gene transcription.

RESULTS

cAMP and DEX stimulated PEPCK promoter obviously; meanwhile, they also had accumulative effects. At different physiological concentrations, insulin had a suppressive effect on PEPCK promoter, which was dose-independent.

CONCLUSION

There is a perfect feedback mechanism for PEPCK promoter in hepatoma cell. 550 bp (-600 -/+ 69) fragment of PEPCK may be a candidate gene in the gene therapy of diabetes.

Analysis of polymorphisms in the promoter region of interleukin-1beta by restriction fragment length polymorphism-PCR

OBJECTIVE

To investigate the frequencies of -1470, -511 and -31 single nucleotide polymorphisms (SNPs) in the promoter of IL-1beta and its haplotype constitution in Chongqing population.

METHODS

One hundred and twelve healthy Chongqing people were enrolled in this study. Polymorphisms at -1470 (G to C), -511 (T to C) and -31 (C to T) of IL-1beta were genotyped with the method of restriction fragment length polymorphism (RFLP). Haplotype frequencies were analyzed by Arlequine software.

RESULTS

Frequencies of IL-1beta -1470, -511 and -31 SNPs were 41.67%, 50% and 45.33%, respectively. Genotype frequencies of -1470 locus were 39.81%, 37.04% and 23.15% for G/G, G/C and C/C respectively. As for T-511C SNP, genotype frequencies of T/T, T/C and C/C were 29.91%, 40.18% and 29.91%, respectively. Genotyping results of C/C, C/T, and T/T of -31 locus were 35.51%, 38.32% and 26.71% respectively. Haplotype analysis found that there were mainly three haplotypes constituted by three SNPs, ie., G-T-C, C-T-C and G-C-T.

CONCLUSIONS

Polymorphisms exist in the promoter of IL-1beta in Chongqing population. Three SNPs locate in the same haplotype block.

[Construction and identification of recombinant firefly luciferase reporter plasmid pGL2-PEPCK-Luc]

OBJECTIVE

To evaluate in vitro regulation of phosphoenolpyruvate carboxykinase (PEPCK) gene promoter on gene transcription, and construct luciferase reporter plasmid pGL2-PEPCK-Luc.

METHODS

A 550 bp fragment of PEPCK promoter cut from plasmid pPEPCK-int was inserted into transitional vector PBS-SK to construct a transition plasmid PBS-PEPCK. Then the recombinant luciferase reporter plasmid pGL2-PEPCK-Luc was cloned.

RESULTS

Restriction enzymes and nucleotide sequence conformed that the coupling site of recombinant plasmid was correct without base mutation and deletion, and the sequence inserted was the same as data of GeneBank. The luciferase could be expressed in hepatoma cell transfected by pGL2-PEPCK-Luc.

CONCLUSION

Established a new means to study transcriptional regulation of PEPCK promoter.

[An investigation of polymorphism in IL-1R1 gene in Chinese population and the functional prediction of a variation in the transmembrane region of IL-1R1]

OBJECTIVE

To identify the single nucleotide polymorphisms (SNPs) in the regulatory and coding regions of human interleukin-1 receptor type I (IL-1R1) gene and to assess their potential effect on the function of IL-1R1.

METHODS

The 5' flank region, exons, parts of the introns, as well as 3' flank region of IL-1R1 gene were sequenced to identify and characterize the SNPs in Chinese population. Effects of the SNP on the structure and function of IL-1R1 were analyzed by computational methods.

RESULTS

Sixteen SNPs were identified through a 9643 bp sequencing of IL-1R1 gene. Among them, four were in 5' flank region, four in intron region, one in coding region, and seven in 3' untranslated region. A novel SNP in Chinese population was involved in a structural change in IL-1R1, which may influence the signal transduction of IL-1R1.

CONCLUSION

The SNP in the IL-1R1 gene might influence its function as an important receptor of IL-1 family.

[Linkage disequilibrium analysis of -31, -511, -1470 single nucleotide polymorphisms in the promoter of IL-1 beta in Chongqing population]

OBJECTIVE

To investigate the frequencies of -31, -511 and -1470 single nucleotide polymorphisms (SNPs) in the promoter of IL-1 beta in Chongqing population and address the question whether they are in linkage disequilibrium (LD).

METHODS

One hundred and twelve healthy Chongqing people were enrolled in this study. Polymorphisms at -31 (C>T), -511 (T>C) and -1470 (G>C) of IL-1 beta were genotyped with the method of restriction fragment length polymorphism (RFLP). Haplotype frequencies were evaluated with Arlequine software. Two-point LD analyses were done with the software TransposerV1-0. The P values were determined by Pearson chi square test analysis.

RESULTS

Allelic frequencies of IL-1 beta -31, -511 and -1470 were 45.33%, 50.00% and 41.67%, respectively. The dominant haplotypes comprising the three loci were T-C-G (44.1%), C-T-C(40.3%) and C-T-G(8.8%), LD analyses revealed that none of the LD parameters(delta value) was 0. Meanwhile, chi square test showed P<0.005.

CONCLUSION

-31, -511 and -1470 loci in the promoter region of IL-1 beta are in strong linkage disequilibrium. And this study provides a basis for searching disease-related IL-1 beta haplotye.

[Preparation of dendritic cell tumor-vaccine with dendritic cells and problems in its clinical uses--review]

Dendritic cell (DC), the most powerful antigen presenting cell, has been paid close attention to tumor immunotherapy. The tumor antigens were extracted by different ways to pulse DC, and then the mature DC were infused to patients to accelerate anti-tumor immuno responses. Its clinical use would provide a new therapeutic pathway other than surgical operation, irradiation, chemotherapy. In this paper, biological characteristics of DC, tumor-vaccine preparation and its clinical use were reviewed.

Distribution of organo-chlorine pesticides (DDT and HCH) between plant and soil system

This paper reports a study of the distribution of organo-chlorine pesticides (DDT and HCH) between rice plants and the soil system by spraying before the heading stage at four different dosage levels--control, normal dosage (15 kg ha(-1) of 6% HCH and 7.5 kg ha(-1) of 25% DDT), double dosage and four times dosage. Soil and plant samples were taken respectively at the 1st h, 3rd, 10th, 20th, and 40th day after spraying and at the harvest time. The results indicate that less than 5% of HCH and 15% of DDT were absorbed by the surface of rice leaves for normal dosage. Most of both pesticides moved into the soil in solution after spraying. Compared with DDT, HCH was degraded and run off more easily. HCH residues in the surface soil layer (1-3 cm) were already below 6.4 microg kg(-1) at the mature stage, lower than Chinese Environmental Quality Standard for Agricultural Soils: HCH < 0.05 mg kg(-1). However DDT residues in the surface soil layer remained 172 microg kg(-1), higher than the national standard: DDT < 0.05 mg kg(-1). According to the test f OCP residues in rice seeds, it can be concluded that the OCP sprayed onto the surface of rice leaves can move into rice plants and accumulate in the seeds at the mature stage. HCH residues in rice seeds of the double and four times dosage treatments, and DDT residues in all treatments, exceeded the Chinese National Food Standard (HCH < 0.10 mg kg(-1), DDT < 0.20 mg kg(-1)).

[Characteristic analysis of acute leukemia immunophenotyping in 180 cases by flow cytometry]

To study the acute Leukemia immunophenotype and its diagnosis value, three color direct immunofluorescece staining methods of flow cytometry and immunophenotype of antibody integration system were used for detection of 180 cases of acute leukemia. The results showed that patients with ALL expressed lymphocyte antigen, and 49.4% patients with ALL accompanied myeloid antigen; all patients with AML expressed myeloid antigen, and 43.2% patients with AML accompanied lymphocyte antigen. In conclusion, leukemia immunophenotyping by three-color direct immunofluore staining methods could define some particular types of leukemia with an important value in diagnosis, treatment and predicting prognosis of acute leukemia.

[Effect of Tpo and/or IL-11 gene modified stromal cells on the expansion of CD34+ CD38- hematopoietic primitive progenitor cells]

OBJECTIVE

To investigate the effects of Tpo and/or IL-11 gene modified stromal cells on the expansion of CD(34)(+) hematopoietic stem/progenitor cells in cord blood.

METHODS

Retroviral vectors containing Tpo or IL-11 gene were constructed and used to transfect the stromal cell line HFCL. Tpo and/or IL-11 mRNA was assayed by Northern blot. Non-modified stromal cells were used, CD(34)(+) hematopoietic stem/progenitor cells from cord blood were expanded on gene-modified stromal cells for 7 days. The phenotype of CD(34)(+)CD(38)(-) primitive progenitors was detected by flow cytometry.

RESULTS

HFCL expressed Tpo and/or IL-11 mRNA after transfected by the retroviral vectors. The percentages of CD(34)(+)CD(38)(-) primitive progenitors in the cultures of Tpo, IL-11 and Tpo + IL-11 modified HFCL were (1.8 +/- 0.24)%, (1.62 +/- 0.23)%, and (2.45 +/- 0.28)%, respectively, which were higher than that in the control [(0.8 +/- 0.23)%].

CONCLUSION

The stromal cells modified by Tpo and/or IL-11 gene were able to enhance ex vivo expansion of CD(34)(+) and CD(34)(+)CD(38)(-) hematopoietic stem/progenitor cells from cord blood.

[Identification of differentially expressed genes in Lin-CD34- and Lin-CD34+ cells]

OBJECTIVE

To identify genes that differentially expressed in Lin(-)CD(34)(-) and Lin(-)CD(34)(+) cells.

METHODS

With Lin(-)CD(34)(-) cells as tester and Lin(-)CD(34)(+) cells as driver, cDNA subtractive library for Lin(-)CD(34)(-) cells was constructed using suppression subtractive hybridization technique. Part of clones in the library were sequenced and the homologue analysis was conducted against the DNA database in GenBank.

RESULTS

593 clones containing an average of 300 - 500 bp insert were identified. Of them, 53 randomly selected ESTs were sequenced. Homologue analysis revealed that 37 ESTs represented 10 known genes, and the other 16 ESTs represented 4 novel sequences.

CONCLUSION

Part of specifically expressed genes in Lin(-)CD(34)(-) cells were identified, which maybe related to Lin(-)CD(34)(-) cells' specific characteristics.

Radioprotective effect of FLT3 ligand expression regulated by Egr-1 regulated element on radiation injury of SCID mice

OBJECTIVE

Hematopoietic factors have an important effect on the regulation of hematopoiesis by stimulating the proliferation of hematopoietic progenitor cells. Although the cytokines that stimulate hematopoiesis have also often proved to exert radioprotective effects, no definitive correlation has been found between the expression of these cytokines regulated by radio-inducible genes and their radioprotective effects. In the current experiments, we evaluated the radioprotective effects of the hematopoietic growth factors regulated by a radio-inducible promoter on radiation injury.

METHODS

The human Flt3 (FL) cDNA and enhanced green fluorescent protein (EGFP) cDNA were linked together with the internal ribosome entry site (IRES) and then inserted into the eukaryotic expression vector pCI-neo with the Egr-1 promoter (Egr-GF), and the vector was transduced into bone marrow stromal cell lines HFCL (HFCL/EGF). The level of green fluorescence in HFCL/EGF cells was detected after radiation with flow cytometry. The expression of FL in irradiated HFCL/EGF cells was confirmed with Northern blot and ELISA. The HFCL/EGF and CD34(+) cells from human umbilical cord blood were sequentially transplanted intravenously into sublethally irradiated severe combined immunodeficient (SCID) mice. The numbers of peripheral white blood cells transplanted into recipient mice were detected.

RESULTS

The activity of EGFP in transfected cells was significantly increased after exposure to gamma radiation at 2.0, 2.5, and 5.0 Gy as compared with nontransfected cells. The expression of FL in HFCL/EGF was significantly higher than that of the control groups (HFCL, HFCL/pCI-neo, and HFCL/FG). The level of secreted FL in serum-free supernatants of HFCL/EGF on human CD34(+) cells was higher than that of control groups. In contrast with three control groups (HFCL, HFCL/pCI-neo, and HFCL/GF), HFCL/EGF resulted in a proportional increase in the number of white blood cells at an early stage after radiation.

CONCLUSIONS

We show that radiation enhances the ability of expression of FL in HFCL/EGF to stimulate the proliferation of hematopoietic progenitor cells. These results suggest in vivo use of gene therapy of FL regulated by the Egr-1 promoter protects hematopoiesis from irradiation-induced damage.

Organo-chlorine pesticide (DDT and HCH) residues in the Taihu Lake Region and its movement in soil-water system I. Field survey of DDT and HCH residues in ecosystem of the region

The use of organo-chlorine (DDT and HCH) has been banned in China for 20 years. A field survey was carried out during 1999-2000 in the Taihu Lake Region. Organo-chlorine pesticide (OCP) residues in soil, water, fish and sediment samples were investigated. DDT was detected in 5 out of 10 samples with concentration ranging from 0.3 to 5.3 microg/kg in the surface (0-15 cm) layer, 6 out of 10 with 0.5 to 4.0 microg/kg in the subsoil layer (16-30 cm), and 4 of 10 with 0 to 2.7 microg/ kg in the deep soil layer (31-50 cm). Results for HCH residues in soil samples were similar to those of DDT. These results indicate that OCP residues in 0-50 cm profile had been leached out or degraded to safe level. In river water DDT was detected in 10 out of 13 samples ranging from 0.2 to 9.3 microg/l, with an average of 1.0 microg/l. While HCH was detected in 12 out of 13 samples ranging from 0.02 to 36.1 microg/l, with an average 5.6 microg/l. DDT residues in sediment ranged from 0.1 to 8.8 microg/kg, while HCH ranged from 0.3 to 66.5 microg/kg. DDT residues in fish body ranged from 3.7 to 23.5 microg/kg and HCH ranged from 3.7 to 132 microg/kg. These results demonstrate an accumulation through food chain (from soil-water-sediment-microbes-crop-fish-... etc.), also that HCH residues are generally more persistent than DDT residues. However, all these data are well below than the state warning standard limit.

[Study on granulocytes derived from induction of committed differentiation of hematopoietic stem/progenitor cells ex vivo]

To evaluated the feasibility of preventing infection after high dose chemotherapy and radiotherapy using the granulocytes derived from differentiated from hematopoietic stem/progenitor cells ex vivo, human CD34-positive cells were isolated from umbilical cord blood by using a high-gradient magnetic cell sorting system (MACS), and the cells committedly differentiated with hematopoietic cytokines (SCF + IL-3 + IL-6 + G-CSF) in a liquid culture system. The expanded cell number, ratio of the viable cells, chromosome and phenotype of the differentiated cells and safety analysis of expanded cells were detected by using cell count, trypan blue exclusion test, karyotype analysis, flow cytometry and tumorigenic model of nude mice, respectively. The results showed that the combination of cytokines increased cell number by (1006.4 +/- 103.2) folds and flow cytometric analysis showed myeloid marker CD11b expressed in the about 60% cells. The growth peak of differentiated cells was at 14 days of culture and decreased at about 33 days. No abnormality was found in the karyotype analysis of expanded cells. No tumor was found in the nude mice injected with expanded cells after 35 days and the expanded cells had the ability of phagocytizing bacteria. It is concluded that the cells, differentiated from CD34(+) cells, expanded ex vivo possess the function of granulocyte and it was safe for clinical trial.

[Expression of telomerase during induction of committed differentiation of human cord blood hematopoietic stem/progenitor cells in vitro]

To investigate the expression of telomerase in cord blood hematopoietic stem/progenitor cells during their committed differentiation in vitro and provide an index of monitoring the proliferating potential of the hematopoietic stem/progenitor cells and security for clinical application. Human CD34 positive cells were isolated from umbilical cord blood by using magnetic cell sorting system (MACS), and were induced to differentiation with hematopoietic growth factors (SCF + IL3 + IL6 + GCSF and SCF + IL3 + IL6 + EPO) in a liquid culture system. The telomerase activity and the cytalytic subunit of telomerase (hTERT) of the cells were analysed during different periods of culture by using TRAP-PCR, TRAP-ELISA, Western blot and RT-PCR techniques, respectively. The results showed that a peak of cell growth was achieved on day 14 - 21 during induction of differentiation in vitro. Total cell number could increase 1006.4 +/- 103.2 times and could not increase there after. Telomerase activity and hTERT expression were low in freshly isolated cord blood CD34(+) cells and increased after about 7 days of culture in addition of cytokine combinations of SCF + IL3 + IL6 + GCSF and SCF + IL3 + IL6 + EPO, respectively. The telomerase activity and hTERT decreased after 14 days of culture and were not detected after 28 days of culture. It was concluded that the hematopoietic stem/progenitor cells can be expanded in large number in vitro and do not have the character of immortality and the telomerase activity could be a useful index in hematopoiesis regulation.

Neurocan: a brain chondroitin sulfate proteoglycan

Neurocan is a chondroitin sulfate proteoglycan of the lectican family and a component of the extracellular matrix of the central nervous system. It is mainly expressed during modeling and remodeling stages of this tissue. Neurocan can bind to various structural extracellular matrix components, such as hyaluronan, heparin, tenascin-C and tenascin-R, and the growth and mobility factors FGF-2, HB-GAM, and amphoterin. Neurocan can also interact with several cell surface molecules, such as N-CAM, L1/Ng-CAM, TAG-1/axonin-1, and an N-cadherin-binding N-acetyl-galactosamine-phosphoryl-transferase, and in vitro studies have shown that neurocan is able to modulate the cell-binding and neurite outgrowth promoting activites of these molecules. Current analysis of the molecular structures and substructures involved in homophilic and heterophilic interactions of these molecules and complementary loss-of-function mutations might shed some light on the roles played by neurocan and interacting molecules in the fine tuning of the nervous system.

[Compound EPSPs and action potential of mauthner cell evoked by skin stimulation in crucian carp]

OBJECTIVE

To investigate the effects of afferent excitatory inputs from skin on the excitability of Mauthner cell (M cell) of crucian carp.

METHODS

Multiple-site intracellular recordings on the soma and the ventral dendrite (VD) of M cell and direct current stimulation on the skin surface of the fish's trunk were employed.

RESULTS

Direct stimulation of the skin evoked 3 groups of compound excitatory postsynaptic potentials (EPSPs) on soma and VD of M cell. Group a EPSP had the lowest amplitude (< or = 0.35 mV), which was insensitive to high-frequency stimulation. It had the shortest latency (mean 1.9 ms) and could be recorded on the soma and the proximal end of VD. Group b EPSP had the highest amplitude (< or = 9.7 mV), which was increased when the recording electrode was moved from the soma to the distal end of VD. The latency of Group b (mean 4.5 ms) was shorter than that of Group c, but longer than that of Group a. We firstly found that action potential could be induced on the basis of Group b in M cell by skin stimulation. Group c EPSP was our new finding, which could only be evoked by higher intensity (noxious) stimulus (> or = 100 V). It had the longest latency (mean 13.5 ms) with amplitude between those of a and b, and was very sensitive to high frequency stimulation. All the three groups of EPSPs were superimposed with spike-like transient potentials, which were believed to be the sign of electrical synapse activities.

CONCLUSIONS

(1) Action potential can be induced on M cell by skin stimulation, which is in controversy with previous reports; (2) the noxious skin stimulation can induce a late EPSP (Group c) in M cell; (3) the neural pathway projecting from skin to M cell is composed of a set of neuronal chains with different number of synaptic relays, in which short chains projected concentrically to the soma and the proximal part of VD, while long chains projected mainly to the distal part of VD; (4) both electrical and chemical synapses may exist in short and long pathways.

[An investigation on morphology of experimental corneal neovascularization]

OBJECTIVE

To observe the morphologic character of the corneal neovascularization in experimental rabbits and also compare it with the morphology of that after irradiation with beta-rays.

METHODS

A model of new blood vessels on the corneas of New Zealand rabbits was established with silver nitrate burning. The growth character of the neovascularization was compared between the irradiated and non-irradiated groups. The casting of the new blood vessels in different periods was made and the morphologic differences between the two groups were compared under a scanning electron microscope.

RESULTS

The corneal new blood vessels occurred and continuously proliferated with the typical method of budding. The formation of buds was obviously inhibited and damaged after irradiation with &#61538 or &#61485 beta-rays, and the irradiated new branches were also atrophic and necrotic.

CONCLUSIONS

Stopping the budding procedure of the corneal neovascularization may inhibit the formation and development of the corneal new blood vessels.

[Generation of Dendritic Cells from Human Cord Blood CD34(+) Cells and Their Activation of T Cell-Dependent Antitumor Immune Response In Vitro]

To induce the growth and differentiation of dendritic cells (DCs) from human cord blood, CD34(+) cells isolated from human cord blood by mini-MACS were cultured in a liquid culture system with rhSCF, rhGM-CSF, rhTNF-alpha and rhFL for 10 days. Then the induced cells were characterized by DC's morphological and phenotypic properties. In addition, they stimulated the proliferation of allogeneic T cells and possessed an efficient capacity for initiating T cell-dependent antitumor immune responses in vitro. It is concluded that mature DCs could be obtained from human cord blood CD34(+) cells.