广州帽峰山森林公园植物区系研究

通过线路调查法对广州帽峰山森林公园进行了植物调查，在采集、鉴定标本和查阅有关资料的基础上研究了该地区的植物区系组成及特点．据统计，帽峰山森林公园有维管植物610种（含种下等级），隶属146科398属．樟科、桑科、山茶科、壳斗科、紫金牛科、芸香科、金缕梅科、冬青科等是该区系的主要表征科，构成了其各森林类型的主要树种组成．该植物区系地理成分复杂多样，种子植物共有375属，划分为13个类型和12个变型，其中以热带一亚热带成分占明显的优势，占该地区种子植物属的80．21％，热带及温带区系成分均有相当的影响，各种区系成分互相渗透．通过对帽峰山森林公园植物区系的归属问题的讨论，认为帽峰山森林公园植物区系是中亚热带向南亚热带过渡的区系类型；是在华南台地上发育起来的，为华南植物区系组成部分，隶属于古热带植物区系．     

红火蚁防控技术研究与应用

为控制外来入侵有害生物红火蚁在广东的定居与蔓延,探讨红火蚁最佳防控技术方法,对高风险入侵区的红火蚁进行GPS定位,利用GIS软件系统制定了入侵区红火蚁分布图,分析了防控工作中红火蚁巢数量动态变化.实践表明,实行普查、复查防控及防控监测三者循环重复,以及"双效合一"的药剂配制方法,对红火蚁防效明显,经济实用.     

多尺度行政区平衡视角下耕地空间布局优化

优化耕地空间布局对提升耕地生产能力、促进农业可持续发展具有重要意义。该研究以广东封开县为例,基于“现状耕地调出-可恢复地类调入”的微观调整逻辑,综合运用空间叠加、综合评价及蚁群优化算法,构建了耕地空间布局调整模型,以调入调出数量平衡为约束条件实现了不同行政区尺度下的耕地布局优化。结果表明：1）研究区共调出耕地1 689.89 hm²,占耕地总面积的7.62%,整体上呈现出“全局零散、局部聚集”的分布特征。2）研究区可恢复地类农业生产适宜性均值为67.04,具有开展作物种植的良好禀赋条件。3）不同行政区尺度平衡情景下,调入结果在研究区北部空间差异显著,与镇内平衡情景相比,县内平衡情景下,调入耕地的农业生产适宜性均值提高了2.08,综合生态系统服务均值下降了0.67。4）两种情景下,耕地的连片性、质量及稳定性均得到提升,因不受调入规模和行政单元空间范围限制,县内平衡情景下的提升效果更加明显,适当扩大可恢复地类筛选范围有利于提升整体耕地质量并降低重要生态用地筛选概率。该研究构建的耕地空间布局调整模型具有良好的适用性,可为制定农用地布局优化与整治提升方案提供参考依据。     

Study on expression of long non-coding RNA in colon cancer tissues and adjacent tissues

AIM: To screen the differentially expressed long non-coding RNA (lncRNA) in colon cancer, and to explore its expression in colon cancer tissues and adjacent tissues. METHODS: The "Colon adenocarcinoma:Person neoplasm cancer status" which consisted of 36 cases of colon cancer tissues and 29 cases of normal colonic tissues was downloaded from the lncRNAtor database. The candidate genes were selected from these differentially expressed lncRNAs based on artificial criterion (P<0.01; fold change ≥ 2 or<0.5) and then validated by real-time PCR in 60 pairs of colon cancer tissues and adjacent tissues. RESULTS: A total of 50 lncRNAs were differentially expressed in colon cancer tissues, including 28 up-regulated and 22 down-regulated (P<0.01). The verifying results displayed that HNF1A-AS1 and ZDHHC8P1 were up-regulated (P<0.01), and SUZ12P expression was down-regulated (P<0.05), but the expression of AC069513.3 was not statistically significant between colon cancer tissues and adjacent tissues. The abilities of HNF1A-AS1, ZDHHC8P1, SUZ12P and AC069513.3 to discriminate the colon cancer from normal adjacent tissue by the ROC curve with an AUC of 0.729 (sensitivity 78%, specificity 67%), 0.617 (sensitivity 68%, specificity 55%), 0.689 (sensitivity 66%, specificity 55%) and 0.518 (sensitivity 52%, specificity 48%) were observed. CONCLUSION: Long non-coding RNA HNF1A-AS1 and ZDHHC8P1 are up-regulated and SUZ12P is down-regulated in colon cancer tissues, suggesting that they may be involved in the pathogenesis of colon cancer.     

miR-222 enhances HBx-HepG2 cell growth via regulation of BCL2L13 gene

AIM: To investigate the regulation of miR-222 on BCL2L13 gene and its effect on the growth and apoptosis of HBx-HepG2 cells, and to explore the underlying molecular mechanisms. METHODS: The expression level of miR-222 was detected by RT-qPCR. The HBx-HepG2 cell growth was examined by MTT and colony formation assays. The cell cycle and apoptosis were analyzed by flow cytometry. The recombination vector pmirGLO-BCL2L13 was constructed, and dual-luciferase reporter experiment was performed to validate the target of miR-222. RESULTS: The expression level of miR-222 in the HBx-HepG2 cells was significantly higher than that in the L02 cells (P<0.05). Over-expression of miR-222 enhanced HBx-HepG2 cell growth, changed cell cycle, and inhibited apoptosis (P<0.05). Knockdown of miR-222 reduced HBx-HepG2 cell growth, changed cell cycle, and increased cell apoptotic rate (P<0.05). BCL2L13 was down-regulated in the HBx-HepG2 cells as compared with L02 cells (P<0.05), and knockdown of miR-222 in the HBx-HepG2 cells increased the expression level of BCL2L13 (P<0.05). The results of dual-luciferase reporter assay and restore experiment showed that miR-222 negatively regulated the expression of BCL2L13 via targeting 3'UTR of BCL2L13, resulting in the promotion of HBx-HepG2 cell growth. CONCLUSION: miR-222 enhances HBx-HepG2 cell growth via down-regulation of BCL2L13.     

Detection and analyses of coagulation and fibrolysis factor mRNA levels in tissue of hepatocellular carcinoma patients

AIM:To detect the mRNA expression of tissue factor (TF), urokinase-type plasminogen activator (u-PA) and urokinase-type plasminogen activator receptor (u-PAR) in the samples of hepatocellular carcinoma (HCC) and adjacent tissue, and to elucidate their association with clinical significance. METHODS:The mRNA levels of TF, u-PA and u-PAR in 27 human HCC tissue samples with their adjacent tissue samples and 27 normal liver tissues were detected by RT-PCR. The relationship between the mRNA expression and their clinic-pathological data were also analyzed. RESULTS:The expressive rate of TF, uPA and uPAR in HCC tissue samples was 62.96% (17/27), 70.37% (19/27), 77.78% (21/27), respectively and relative expression intensity of TF, uPA and uPAR were 0.567±0.268, 0.964±0.458 and 0.784±0.322, respectively, which were significantly higher than those in adjacent tissue group and normal liver group (P<0.05). TF, uPA and uPAR mRNA levels were all significantly higher in larger size and in the invasive and metastatic subgroup (P<0.05). There had positive relationship between the mRNA expressions of these three factors. CONCLUSION:The results indicate that TF, uPA and uPAR might play an important role in hepatic carcinogenesis, invasiveness and metastasis.     

Effect of preoperative transarterial chemoembolization on nephroblastoma

AIM: To explore the effect and mechanism of preoperative transarterial chemoembolization on nephroblastoma.METHODS: Comparative analysis of clinical and pathological features in 39 children with Wilms’ tumor was conducted.TUNEL assay was used to detect the apoptosis of tumor in two groups with or without preoperative interventional treatment.The expressions of P53,Bcl-2 and Bax proteins were detected by immunochemical methods.The patients were followed-up for more than 2 years.RESULTS: The extent of neoplastic cell necrosis and degeneration,interstital fiber tissue hyperplasia of tumor and the number of infiltrating lymphocytes were observed,which were higher in interventional group than those in simple excision group (P<0.01).The median of mitotic index in tumor cells was 0.2 in interventional group,and 1.4 in simple excision group.The median of apoptotic index (AI) of the tumor cells was 25.9 in study group and 12.8 in control group (Uc=54.50,P<0.01),(Uc=117.00,P<0.05).The comparison between the means obtained in two groups revealed statistical difference (P<0.05).The expressions of P53 and Bcl-2 proteins were not correlated with apoptotic index,but the rate of expression of Bax protein (80.0%) in interventional group was higher than that (40.0%) in simple excision group.The two year event-free rate was 73.3％ (11/15) in study group and 42.9％ (6/14) in control group.CONCLUSION: Transarterial chemoembolization on nephroblastoma is effectively used to kill and inhibit tumor cell growth,as well as induce tumor cell apoptosis by Bax protein.     

Expression of EPCAM,CD44 and CD24 in gastric cancer tissues and its clinical significance

AIM: To evaluate the relationship between epithelial cell adhesion molecule (EPCAM)/cluster of differentiation 44 (CD44)/cluster of differentiation 24 (CD24) expression and the clinicopathological characteristics/prognosis in 95 gastric cancer patients. METHODS: The expression levels of EPCAM, CD44 and CD24 were detected using the two-step method of immunohistochemistry in 95 gastric cancer patients who underwent surgical excision and were pathologically diagnosed as gastric cancer. RESULTS: There were 56 EPCAM-positive patients (58.95%), 41 CD44-positive patients (43.16%) and 56 CD24-positive patients (58.95%). Thirty patients were both EPCAM and CD44 positive (31.58%), 45 patients were both EPCAM and CD24 positive (47.37%), 32 patients were both CD44 and CD24 positive (33.68%), and 25 patients were EPCAM, CD44 and CD24 positive (26.32%). EPCAM expression was correlated with age, depth of tumor infiltration and WHO histological classification. CD44 expression was correlated with BORRMANN and WHO histological classification as well as CEA value. CD24 expression was correlated with the depth of infiltration, location of the tumor, WHO histological classification and viscera invasion. All positive expression of EPCAM, CD44 and CD24 was correlated with the depth of infiltration, location of the tumor and WHO histological classification (P<0.05). The difference of survival rate between EPCAM positive group and negative group was observed, and the CD44 positive group and negative group had the same result (P<0.05 and P<0.01, respectively). The difference of survival rate between EPCAM⁺CD44⁺CD24⁺ group and EPCAM^-CD44^-CD24^- group was statistically significant (P<0.05). The difference of survival rate between EPCAM^-CD44⁺CD24⁺ group and EPCAM^-CD44^-CD24^- group was also significant (P<0.05). CONCLUSION: The positive rates of EPCAM, CD44 and CD24 expression are high in gastric cancer tissues and these 3 proteins can be used as primary screening targets.     

短期夜间低温对栽培番茄和野生番茄果实蔗糖代谢的影响

 在人工气候室内以低温敏感的栽培番茄（Solanum lycopersicon）‘Money Maker’和耐低温的野生番茄（S. habrochaites）‘LA1777’为试材,研究了短期（4 d）夜间15 ℃处理和9 ℃、6 ℃及其恢复处理对番茄果实糖含量和蔗糖代谢相关酶活性的变化。结果表明：6 ℃处理0.5 d,耐低温的番茄（‘LA1777’）果实中果糖和葡萄糖含量升高,低温敏感番茄（‘Money Maker’）果实中两种糖含量无显著变化。6 ℃处理‘Money Maker’中蔗糖和淀粉的含量显著降低,而‘LA1777’中含量提高。在恢复期,两种番茄的蔗糖含量均恢复到对照水平,6 ℃处理的葡萄糖和果糖未恢复到对照水平,而9 ℃与对照无显著差异。6 ℃处理降低两种番茄果实中转化酶和蔗糖合成酶（SS分解方向）的活性,无法恢复至对照水平,‘Money Maker’果实中SS合成方向的活性和蔗糖磷酸合成酶（SPS）活性提高,而‘LA1777’变化不显著。说明短期夜间低温条件下耐低温的番茄是通过提高果实中总的碳水化合物含量来适应低温胁迫的,而低温敏感的番茄则是降低果实中碳水化合物含量来响应低温。     

Mutations of K-ras oncogene in primary colorectal tumors,related liver metastases and portal vein blood of patients with colorectal cancer

AIM: To evaluate the concordance of K-ras oncogene mutations in primary colorectal tumors, liver metastases and portal vein blood of the patients with colorectal cancer, and to find out the relationship between mutated K-ras oncogene and liver metastases in colorectal cancer.METHODS: Fifty-nine patients with colorectal cancer were screened for the mutations of K-ras oncogene in the tissue samples of primary tumors, portal vein blood and liver metastases (only 15 cases of the 59 patients) by real-time fluorescence quantitative PCR and DNA sequencing. The results were also analyzed with the clinical data of the patients.RESULTS: Point mutations of K-ras were found in the primary tumors in 20 (33.9%) of the 59 patients with colorectal cancer, and 18 (30.5%) of the 59 patients in their portal vein blood. K-ras mutations in 8 (53.3%) of 15 liver metastases were also detected. No significant difference among the rates of K-ras mutation in primary tumor tissues, portal vein blood and related liver metastases was observed (P>0.05). Eighteen cases with mutated K-ras gene in portal vein blood showed the mutations in primary tumor tissues. The patients without mutated K-ras gene in primary tumor tissue also showed negative mutation of K-ras in the portal vein blood. The mutated K-ras gene in both liver metastase and portal vein blood were detected in 8 of the 15 cases with liver metastases, and no mutated K-ras gene was detected in the others with liver metastases. The main types of K-ras mutations found in primary tumors, liver metastases (5 simultaneous, 2 metachronous) and portal vein blood were GGT to GAT and GGT to GTT at codon 12. A K-ras mutation at codon 13 (GGC to GAC) was found in one case with metachronous liver metastases. The rate of concordance of K-ras status between primary tumors and portal vein blood was 96.6%. Detection of K-ras mutations in liver metastases was accordant with that in portal vein blood, but the type of K-ras mutation was partially discordant.CONCLUSION: The K-ras mutations in primary tumors, liver metastases and portal vein blood of patients with colorectal cancer are concordant, and mutated K-ras detected in both cancer tissue and portal vein blood may indicate liver micrometastases from colorectal cancer.