ObjectiveBased on the method of bibliometrics, to visually analyze the current research status of DNA polymerase epsilon catalytic/DNA polymerase delta catalytic subunit (POLE/POLD1) mutations in colorectal cancer, and further to explore its current hot spots and to look forward to future development trends.MethodsUsed the Web of Science database as the data source to retrieve the published related literatures in the 30 years from the establishment of the database to September 2020, and used VOSviewer 1.6.11 and CiteSpace 5.7 software to analyze the the distribution of research countries/institutions, authors and keywords in the included published literatures. And to perform cluster analysis, time evolution analysis and Burst analysis on keywords, draw corresponding visual maps and analyzed them.ResultsA total of 299 published articles were included. Bibliometric analysis showed that the application of POLE/POLD1 mutations in colorectal cancer had developed steadily in recent years. After 2012, the number of published studies had increased significantly; the journals with the most articles were Familial Cancer and Proceedings of the National Academy of Sciences of the United States of America. The author with the highest number of articles was Tomlinson I. The analysis of countries and regions showed that the United States was the main country for research in this field and had contributed the most to the amount of publications. After analyzed the academic institutions/universities where the researchers were located, it could be seen that the University of Oxford was the research university/institution with the most publications. Keyword cluster analysis and time evolution analysis showed that the research hotspots in this field focus on the impact of this gene mutation on immunotherapy. Burst analysis showed that the current published research in this field started two years after publication and continues to be highly cited.ConclusionsPOLE/POLD1 mutation has undoubtedly become a hot area of current research in colorectal cancer research. Among them, tumor immunotherapy is the focus of research in this field.
【Abstract】Objective To explore the changes of expression of AFP mRNA in human hepatocellular carcinoma （HCC） tissues after oral Xeloda therapy.Methods Total RNA was extracted from HCC tissue samples collect after operation and nested reverse transcription polymerase chain reaction （RT-nested PCR） assay was performed to determine the expression of AFP mRNA in this study.Results The final product of AFP mRNA amplified by RT-PCR was 174 bp and by RT-nested PCR was 101 bp. The AFP mRNA is positive in 12 of 21 patients (positive rate 57.14%) amplified by RT-nested PCR assay in Xeloda treatment group which is much lower than control group: 18 of 20 patients (positive rate 90.00%),P＜0.05.The serum AFP value of Xeloda treatment group 〔(23.2±12.8) μg/L〕 is much lower than that of control group 〔(39.6±24.3) μg/L〕 four weeks after operation (P＜0.05). However, There was no difference between two groups in serum AFP value before operation.Conclusion Xeloda can effectively suppress the expression of AFP mRNA in human HCC tissues and lower it’s product serum AFP value.The clinical application of Xeloda in HCC patients deserve further study.
A multiple-stimuli-responsive drug-conjugated cross-linked micelles was prepared by radical copolymerization. The chemical structure, morphology, and size of the cross-linked micelles were characterized, and the drug loading of the micelle was calculated. The experimental results indicated that the hydrodynamic size of the drug-loaded micelles were about 100 nm, and the as prepared micelles could be degraded and swelled in presence of reducing glutathione (GSH). The low critical solution temperature (LCST) of the micelle was around 39.4℃. According to the experimental results, the micelles will shrink at temperature above the LCST. Subsequently, the accumulative drug release rate was up to 91.78% under acidic (pH 5.0), reductive (GSH 10 mmol/L) and high temperature (42.0℃) conditions mimicking the tumor microenvironment, while a relatively low release rate of 1.12% was observed without stimulation. The drug-conjugated cross-linked micelles showed a strong cell uptake behavior. In the cytotoxicity assay, the micelles exhibited effective anti-cancer activity and excellent biocompatibility. In brief, the experimental results show that the as-prepared drug-conjugated cross-linked micelle exhibits multiple stimuli-responsiveness, which holds great promise for anti-cancer drug delivery.
Objective：To observe the expression of gene and protein l evel of unfolded protein, glucoseregulated protein 78 (GRP78), after retinal d etachment (RD); to find out the relationship between UPR and the cell damage after RD.
Methods：Eightyeight Wistar rats were divided into 2 groups: con trol group (11 rats) and RD group (77 rats). In RD group, subretinal injection with 10 mg/ml hyaluronic acid sodium was performed on the left eyes of the rats t o set up RD model, and the left eyes and retinal tissue were collected 1/2 day, 1 day, 2, 4, 8, 1 6 and 32 days after RD; there were 11 rats in each subgroup. The expression of G RP78 mRNA in retina tissue was detected by semiquantitative reverse transcript i on polymerase chain reaction (RT－PCR), the expression of GRP78 protein level wa s detected by Western blotting, and the distribution of GRP78 in each retinal lay er was observed by immunofluorescence labeling method and confocal microscopy.
Results：The expression of retinal GRP78 mRNA significantly in creased in 1/2 day , 1 day, 2, and 4 days subgroups after RD (Plt;0.05). The expression of GRP7 8 protein significantly increased in each subgroup after RD compared with which in the control group, and reached the peak in 8, 16, and 32 days subgroups. The expres sion of GRP78 protein was detected in all of the retinal layers after RD.
Conclusion：The protection mechanism of UPR starts up after RD, and l eads the correc t pucker of the protein and reduces cellular injury by upregulating the expres s ion of GRP78, which provide the theoretic basis for reducing the cellular injury and improving the visual function in patients with RD.
With the method of PCR-SSCP combined sequencing,we analysed the mutations in the RB1 gene of 10 retinoblastoma samples. All 27 exons of RB1 gene have been examined. The PCR products were digested with some restriction endonuclease to the size of about 200 bp and then denatured into single strands. Loading the single strands of DNA into the 6% polyacrilamide gel,we followed the technology named SSCP to f/nd the abnormal bands in the SSCP gel. After that, the samples found with the abnormal bands in the SSCP gel were amplified again and sequenced to confirm the types and locations of the mutations in the RB1 gene. We have fonnd some kinds of mutations in the RB1 gene.
（Chin J Ocul Fundus Dis,1994,10:17-20）
【Abstract】ObjectiveTo discuss the possibility and clinical significance of SSX-1 mRNA used as specific marker for examining HCC cells in peripheral blood of HCC patients. MethodsUsing the RT-PCR method, the SSX1 mRNA of the peripheral blood was examined in 25 cases of HCC patients and 20 non-HCC patients. The same method was used to detect the expression of SSX-1 mRNA in the tumor tissues, para-tumor tissues, cirrhosis tissues and normal hepatic tissues. A randomized sample was extracted for DNA sequencing from positive electrophoresis expression samples of SSX-1 to examine the reliability of results. ResultsThe expression rates of SSX-1 mRNA were 60%(15/25) and 40%（10/25） respectively in tumor tissues of HCC and the corresponding peripheral blood. SSX-1 mRNA were not expressed in para-tumor tissues,cirrhosis tissues and normal hepatic tissues. The DNA sequence -confirmed that the RTPCR products were true target cDNA. No relationships were found between the expression of SSX-1 gene and clinical characteristics, such as age, sex, tumor size, TNM stage， extent of differentiation and serum AFP level (Pgt;0.05). However, in 33%（3/9） patients with normal serum AFP (lt;20 μg/L), specific expression of SSX1 mRNA was observed. ConclusionHigh specific expression of SSX-1 mRNA is observed in the peripheral blood of patients with HCC, it suggests that applying it as a tumor marker to detect HCC cells in peripheral blood is an adjuvant diagnostic tool. The expression of SSX-1 mRNA in the peripheral blood is observed in the group HCC patients whose serum AFP (lt;20 μg/L) are normal, which suggests that applying both SSX-1 mRNA and AFP as tumor markers together might be useful to improve the diagnostic accuracy for HCC.
Objective To verify whetheriris pigment epithelial cells(IPECs)possess the similar potential of specific phagocytosis to retinal outer segments(ROS) with retinal pigment epithelialcells(RPECs). Methods IPESc were isolated from neonatal bovines with Hu's method,and were cultured.The cultured cells were identified by immunohistochemical methods with antibodies to cytokeratin and s-100.Total RNA of IPECs was extracted by Trizol.The specific primers for mannose-receptor andbeta;-actin were designed according to their sequence from Genbank.The mRNA expression of these proteins in the IPECs was analyzed by reverse transcription polymerase chain-reaction (RT-PCT).Results The Cultured IPECs have no contamination of other cells .The extracted RNA was ideal and had no degradation.RT-PCR analysis showed that mannose-receptor's mRNA was expressed in cultured IPECs in vitro.ConclusionCultured IPECs may express the mannose-receptor,and may have similar potential of phagocytosis to ROS with REPCs.
The convective polymerase chain reaction (CCPCR) uses the principle of thermal convection to allow the reagent to flow in the test tube and achieve the purpose of amplification by the temperature difference between the upper and lower portions of the test tube. In order to detect the amplification effect in real time, we added a fluorophore to the reagent system to reflect the amplification in real time through the intensity of fluorescence. The experimental results show that the fluorescence curve conforms to the S-type trend of the amplification curve, but there is a certain jitter condition due to the instability of the thermal convection, which is not conducive to the calculation of the cycle threshold (CT value). In order to solve this problem, this paper uses the dynamic method, using the double S-type function model to fit the curve, so that the fluorescence curve is smooth and the initial concentration of the nucleic acid can be deduced better to achieve the quantitative purpose based on the curve. At the same time, the PSO+ algorithm is used to solve the double s-type function parameters, that is, particle swarm optimization (PSO) algorithm combined with Levenberg-Marquardt, Newton-CG and other algorithms for curve fitting. The proposed method effectively overcoms PSO randomness and the shortcoming of traditional algorithms such as Levenberg-Marquardt and Newton-CG which are easy to fall into the local optimal solution. The R2 of the data fitting result can reach 0.999 8. This study is of guiding significance for the future quantitative detection of real-time fluorescent heat convection amplification.
Objective
To evaluate the application of artificial lamina of multi-amino-acid copolymer (MAACP)/nano-hydroxyapatite (n-HA) in prevention of epidural adhesion and compression of scar tissue after posterior cervical laminectomy.
Methods
Fifteen 2-year-old male goats [weighing, (30 ± 2) kg] were randomly divided into experimental group (n=9) and control group (n=6). In the experimental group, C4 laminectomy was performed, followed by MAACP/n-HA artificial lamina implantations; in the control group, only C4 laminectomy was performed. At 4, 12, and 24 weeks after operation, 2, 2, and 5 goats in the experimental group and 2, 2, and 2 goats in the control group were selected for observation of wound infection, artificial laminar fragmentation and displacement, and its shape; Rydell’s degree of adhesion criteria was used to evaluate the adhesion degree between 2 groups. X-ray and CT images were observed; at 24 weeks after operation, CT scan was used to measure the spinal canal area and the sagittal diameter of C3, C4, and C5 vertebrea, 2 normal goats served as normal group; and MRI was used to assess adhesion and compression of scar tissue on the dura and the nerve root. Then goats were sacrificed and histological observation was carried out.
Results
After operation, the wound healed well; no toxicity or elimination reaction was observed. According to Rydell’s degree of adhesion criteria, adhesion in the experimental group was significantly slighter than that in the control group (Z=
—
2.52, P=0.00). X-ray and CT scan showed that no dislocation of artificial lamina occurred, new cervical bone formed in the defect, and bony spinal canal was rebuilt in the experimental group. Defects of C4 vertebral plate and spinous process were observed in the control group. At 24 weeks, the spinal canal area and sagittal diameter of C4 in the experimental group and normal group were significantly larger than those in the control group (P lt; 0.05), but no significant difference was found between experimental group and normal group (P gt; 0.05). MRI showed cerebrospinal fluid signal was unobstructed and no soft tissue projected into the spinal canal in the experimental group; scar tissue projected into the spinal canal and the dura were compressed by scar tissue in the control group. HE staining and Masson trichrome staining showed that artificial lamina had no obvious degradation with high integrity, some new bone formed at interface between the artificial material and bone in the experimental group; fibrous tissue grew into defect in the control group.
Conclusion
The MAACP/n-HA artificial lamina could maintaine good biomechanical properties for a long time in vivo and could effectively prevent the epidural scar from growing in the lamina defect area.
Objective
To investigate the effect of hypoxia on expressions of erythropoietin（EPO）mRNA and protein in retinal Muuml;ller cells cultured in vitro.
Methods
Retina tissues from the new-born Wistar rats were dissected into cell suspension after digested by pancreatin.Muuml;ller cells were separated and purified by mechanical concussion and blowing and striking method.The expression of EPO mRNA and protein under the condition of hypoxia was detected by semi-quantitative reverse transcriptase（RT）-polymerase chain reaction（PCR）and immunocytochemical method.
Results
Retinal Muuml;ller cells were cultured successfully，95% of which were positively stained by glial fibrillary acidic protein（GFAP）.Positively stained EPO protein was located in the cytoplasm and protuberance.The expression of EPO mRNA and protein was faint in the normal retinal Muuml;ller cells，but increased obviously and time-dependently after hypoxia.
Conclusion
Expression of EPO mRNA and protein increases in Muuml;ller cells after hypoxia，which may be one of the protective factors for the nerves in anoxic retinopathy.
(Chin J Ocul Fundus Dis, 2006, 22: 196-199)
