Repression of allo-cell transplant rejection through CⅡTA ribonuclease P^+hepatocyte

AIM: Allo-cell transplant rejection and autoimmune responses were associated with the presence of class Ⅱmajor histocompatibility complex (MHC Ⅱ) molecules on cells.This paper studied the effect of Ribonuclease P (RNase P)against CIITA, which was a major regulator of MHCII molecules, on repressing the expression of MHCII molecules on hepatocyte.METHODS: M1-RNA is the catalytic RNA subunit of RNase P from Escherichia coli. It were constructed that M1-RNA with guide sequences (GS) recognizing the 452, 3408 site of CIITA by PCR from pTK117 plasmid, then were cloned into the EcoRI/Bg/II or EcoR//SalIsite of vector psNAV (osNAV-M1-452-GS, psNAV-M1-3408-GS) respectively. The target mould plate (3176-3560) of CIITA was obtained from Raji cell by RT-PCR, and then inserted into the XhoI/EcoRIof pGEM-7zf(+) plasmid (pGEM-3176). These recombinant plasmids were screened out by sequence analysis. psNAV-M 1-452-GS, psNAV-M1-3408-GS and its target RNA pGEM-3176 were transcribed and then mixed up and incubated in vitro. It showed that M1-3408-GS could exclusively cleave target RNA that formed a base pair with the GS. Stable transfectants of hepatocyte cell line with psNAVl-M1-3408-GS were tested for expression of class Ⅱ MHC through FCM, for mRNA abundance of MHCII, Ii and CIITA by RTPCR., for the level of IL-2 mRNA on T cell by mixed lymphocyte reaction.RESULTS: When induced with recombinant human interferon-gamma (IFN-γ), the expression of HLA-DR, -DP,-DQ on psNAV-M1-3408-GS+ hepatocyte was reduced 83.27 %, 88.93 %, 58.82 % respectively, the mRNA contents of CIITA, HLA-DR, -DP, -DQ and Ii decreased significantly.While T cell expressed less IL-2 mRNA in the case of psNAV-M1-3408-GS+ hepatocyte.CONCLUSION: The Ribonuclease P against CIITA-M1-3408-GS could effectively induce antigen-specific tolerance through cleaving CIITA. These results provided insight into the future application of M1-3408-GS as a new nucleic acid drug against allo-transplantation rejection and autoimmune diseases.

Endoscopic survey of esophageal cancer in a high-risk area of China

AIM: To characterize the histological types of esophageal and cardiac mucosa by endoscopic survey of a population in a high-risk area of esophageal cancer of China. METHODS: A selected cohort of residents in Cixian County during December 2001 and May 2002 was surveyed by using Lugol's staining, followed by computer-based statistical analysis of the data with SPSS 10.0 software. RESULTS: Histologically, the detection rates of squamous epithelial acanthosis, squamous epithelial atrophy, and basal cell hyperplasia in the esophagus were 1.9% (38/2013),0.1% (3/2013) and 0.9% (18/2013) respectively, and those of mild, moderate, and severe esophagitis were 34.9% (703/2013), 1.6% (33/2013) and 0.2% (2/2013) respectively. Mild, moderate, and severe esophageal dysplasia were detected in 8.6% (172/2013), 7.8% (157/2013) and 2.6% (53/2013) respectively in the selected population, whereas in situ carcinoma, intramucosal carcinoma, invasive squamous carcinoma of the esophagus in 2.5% (50/2013),0.2% (4/2013) and 0.7% (14/2013) respectively. The detection rates of non-atrophic gastritis and atrophic gastritis of the cardia were 36.3% (730/2013) and 11.5% (232/2013) respectively, with mild and severe dysplasia of the cardia detected in 2.5% (51/2013) and 0.8% (17/2013), respectively, in this population; the rates of intramucosal adenocarcinoma and invasive adenocarcinoma of the cardia were 0.1% (3/2013) and 0.8% (17/2013) respectively. The detection rate of esophageal cancer at early stage was 79.4% (54/68). The survey rate (ratio of examined population to expected population) was 73.8% (2013/2725). CONCLUSION: Histologic types of the esophageal and cardiac mucosa were characterized by endoscopic survey in a high-risk population of esophageal cancer, which may help the early detection and treatment of esophageal and cardiac cancers and dysplasia, and reduce the mortality of such malignancies.

C-kit gene mutation in human gastrointestinal stromal tumors

AIM: TO investigate the significance of c-kit gene mutation in gastrointestinal stromal tumors (GIST).METHODS: Fifty two cases of GIST and 28 cases of other tumors were examined. DNA samples were extracted from paraffin sections and fresh blocks. Exons 11, 9 and 13 of the c-kit gene were amplified by PCR and sequenced.RESULTS: Mutations of exon 11 were found in 14 of 25 malignant GISTs (56%), mutations of exon 11 of the c-kit gene were revealed in 2 of 19 borderline GISTs (10.5%),and no mutation was found in benign tumors. The mutation rate showed significant difference (x^2=14.39, P<0.01) between malignant and benign GISTs. Most of mutations consisted of the in-frame deletion or replication from 3 to 48 bp in heterozygous and homozygous fashions, None of the mutations disrupted the downstream reading frame of the gene. Point mutations and frame deletions were most frequently observed at codons 550-560, but duplications were most concentrated at codons 570-585. No mutations of exons 9 and 13 were revealed in GISTs, Neither c-kit gene expression nor gene mutations were found in 3 leiomyomas, 8 leiomyosarcomas, 2 schwannomas, 2 malignant peripheral nerve sheath tumors, 2 intra-abdominal fibromatoses, 2 malignant fibrous histiocytomas and 9 adenocarcinomas.CONCLUSION: C-kit gene mutations occur preferentially in malignant GISTs and might be a clinically useful adjunct marker in the evaluation of GISTs and can help to differentiate GISTs from other mesenchymal tumors of gastrointestinal tract, such as smooth muscle tumors,schwannomas, etc.

A Survey of Esophageal Cancer in Cixian County of Hebei Province

OBJECTIVE To characterize the histologic types of esophageal cardiac mucosa by endoscopic survey in a high-risk cancer area of China. METHODS An endoscopic survey with Lugol,s staining was carried out in Cixian County, Hebei Province from December 2001 to May 2002. The data were processed using computer SPSS 10.0 software. RESULTS The incidences of mild esophagitis, moderate esophagitis, and severe esophagitis were for 2013 cases, 34.9%(703), 1.6%(33) and 0.1% (2)respectively; those with mild dysplasia, moderate dysplasia, severe dysplasia of the esophagus were 8.6% (172), 7.8% (157) and 2.6% (53) respectively; those with carcinoma in situ, intramucosal carcinoma, invasive squamous carcinoma of the esophagus were 2.5%(50), 0.2% (4) and 0.7%(14) respectively. The histologic-detecting rates of non-atrophic gastritis, and atrophic gastritis of the cardia were 36.3%(730), 11.5% (232) respectively; those with mild dysplasia, severe dysplasia of the cardia were 2.5%(51), 0.8%(17) respectively; those with intramucosal adenocarcinoma, invasive adenocarcinoma of the cardia were 0.1% (3), 0.8%(17) respectively. The early-detection rate of esophageal cancer was 79.4%(54/68). The survey rate(examined population to covered population) was 73.8% (2013/2725). CONCLUSIONS Esophageal endoscopic screening with Lugol's solution staining has an advantage over esophageal balloon cytology, in that the histological diagnoses of esophageal cardiac diseases can be obtained, thus contributing to the prevention of subsequent disease. In using the staining method the detection rate of early esophageal cancer is higher than that revealed by balloon cytology.

Fabricate organic thermoelectric modules use modified PCBM and PEDOT：PSS materials

In this paper, we fabricated an organic thermo- electric （TE） device with modified [6,6]-phenyl-C61- butyric acid methyl ester （PCBM） and poly（3,4-ethylene- dioxythiophene） polystyrene sulfonate （PEDOT：PSS）; the device showed good stability in air condition. For n-leg, PCBM were doped with acridine orange base （3,6-bis （dimethylamino）acridine） （AOB） and 1,3-dimethyl-2,3- dihydro- 1H-benzoimidazole （N-DMBI）. Co-doped PCBM utilizes synergistic effects of AOB and N-DMBI, resulting in excellent electrical conductivity and Seebeck coefficient values reaching 2 S/cm and -500 μV/K, respectively, at room temperature with dopant molar ratio of 0.11. P-type leg used modified PEDOT：PSS. Based on modified PCBM and PEDOT：PSS materials, we fabricated a TE module device with 48 p-type and n-type thermocouple and tested their output voltage, short current, and power. Output voltage measured -0.82 V, and generated power reached almost 945 μW with 75 K temperature gradient at 453 K hot-side temperature. These promising results showed potential of modified PEDOT and PCBM as TE materials for application in device optimization.