广东省种子植物分布新资料

报道广东省种子植物分布新记录2属——甜茅属(Glyceria R. Br.)及锦鸡儿属(Caragana Fabr.)，2个新记录种——甜茅[Glyceria acutiflora subsp. japonica (Steud.) T. Koyama et Kawano]及锦鸡儿[Caragana sinica (Buc’hoz) Rehder]，均发现于丹霞山国家级自然保护区。新记录的发现对于研究丹霞山的区系发生具有一定指示意义。     

PET-CT在非完全实性肺结节中的应用价值

肺癌在中国恶性肿瘤的发病率位居第一,随着低剂量薄层CT在肺癌筛查中的广泛应用,临床发现更多表现为非完全实性结节的肺腺癌,目前众多研究使CT影像学特征和肺腺癌病理的关系得到更进一步的认知,虽然CT能对部分非完全实性结节做出定性和定位诊断,但仍有部分非完全实性结节诊断困难,PET-CT结合了病灶的代谢信息和精确的定位信息,从而提高对肺部结节诊断的敏感性、特异性、准确性,综合多个文献PET-CT在非完全实性结节中的诊断分期价值较CT无明显提升,却在评估预后和制定合适手术方案上可以起到一定的作用,本文就PET-CT在SSN中的应用价值进行阐述。     

Methylation of KvDMR1 involved in regulating the imprinting of CDKN1C gene in cattle

The CDKN1C gene encodes a cyclin‐dependent kinase inhibitor and is one of the key genes involved in the development of Beckwith–Wiedemann syndrome and cancer. In this study, using a direct sequencing approach based on a single nucleotide polymorphism (SNP) at genomic DNA and cDNA levels, we show that CDKN1C exhibits monoallelic expression in all seven studied organs (heart, liver, spleen, lung, kidney, muscle and subcutaneous fat) in cattle. To investigate how methylation regulates imprinting of CDKN1C in cattle, allele‐specific methylation patterns in two putative differential methylation regions (DMRs), the CDKN1C DMR and KvDMR1, were analyzed in three tissues (liver, spleen and lung) using bisulfite sequencing PCR. Our results show that in the CDKN1C DMR both parental alleles were unmethylated in all three analyzed tissues. In contrast, KvDMR1 was differentially methylated between the two parental alleles in the same tissues. Statistical analysis showed that there is a significant difference in the methylation level between the two parental alleles (P < 0.01), confirming that this region is the DMR of KvDMR1 and that it may be correlated with CDKN1C imprinting.     

经甫树蛙的染色体组型、C带和Ag-NORs的研究

本文分别用骨髓细胞染色体标本制作法、BSG技术和一种快速、简便的Ag-NORs显带技术,首次研究了经甫树蛙的染色体组型、C带和Ag-NORs。结果表明,经甫树蛙2n=26,有5对大型和8对小型染色体,次缢痕在No.11染色体长臂末端,为C带负染;银染表明,此次缢痕处即是经甫树蛙的“标准NORs”经甫树娃的C带结构异染色质主要是着丝点型和插入型的。文章初步讨论了树蛙属的细胞分类、经甫树蛙次缢痕、Ag-NORs和C带的关系。     

电刺激大鼠尾核头部对丘脑腹后外侧核痛相关神经元电活动的影响

丘脑腹后外侧核的神经元对伤害性刺激的反应形式主要为以下三种类型:痛兴奋神经元、痛抑制神经元和痛无关神经元。痛相关神经元的放电活动可被吗啡类药物所抑制。电刺激尾核头部对痛相关神经元主要产生抑制作用,尾核头部背侧的作用强于腹侧,且受不同刺激参数的影响。本文就以上结果在镇痛中的意义进行了讨论。     

中国东方铃蟾(Bombina orientalis)皮肤中C_(-12-b)肽的分离与鉴定

东方铃蟾鲜皮的甲醇提取液,可引起大鼠离体平滑肌的收缩。此液经碱性氧化铝柱层析分离,其80%乙醇洗脱的 C 组分显示生物活性。C 组分再经葡聚糖凝胶 G-15柱分离,其活性较强的早期洗脱组分 C_(_12),可被糜蛋白酶水解灭活,但其活性并不被5-HT 拮抗剂赛庚啶[2×10~(-6)mol/L]完全拮抗。继用反相高效液相色谱(RP-HPLC)分析,见分离出的 C_(_12_h)峰与铃蟾肽~*(Bombesin,BBS)的出峰时间相同,且具相同的氨基酸组成。上述实验结果提示,C_(_12_h)肽可能就是铃蟾肽。