寡聚脱氧核苷酸d(G-C)_3的激光喇曼谱及其分析

用改进的固相磷酰三酯法合成了oligo-d(G-C)_3。以氩离子激光为激发光源,波长488nm.,在室温条件下,分别测定了纯化后的oligo-d(G-C)_3和其组分单体5’-dGMP和5’-dCMP的激光喇曼谱。观察到被测定的物质在300-2500cm~(-1)频率区间,各自都有其特征的谱形和喇曼峰。5’-dGMP和5’-dCMP谱中大多数特征峰在寡聚体的谱中消失,而在oligo-d(G-C)_3谱中出现了几处新的喇曼峰。经查证,峰832,851和899cm~(-1)系糖-磷酸主链的特征喇曼峰,另外几处峰与DNA的构象有关。实验结果表明oligo-d(G-C)_3在水溶液中(室温)主要以B-构象存在。     

Modulation of hepatic level of microsomal testosterone 7 alpha-hydroxylase, P-450a (P450IIA), by thyroid hormone and growth hormone in rat liver

The effects of thyroid hormone and growth hormone on microsomal testosterone 7 alpha-hydroxylase, P-450a, were studied to understand the interaction of these hormone-mediated regulations in rats. In Western blots using anti-P-450a IgG, 1.7-fold higher content of P-450a was observed in livers of female than male adult rats, while no appreciable sex-related difference was detected in prepubertal rats and rats of 24 months of age. Treatment with n-propyl-2-thiouracil or thyroidectomy of male rats increased by 2-fold the hepatic content of P-450a, but neither regimen had a significant effect on the content in female rats. Levels of P-450a in both sexes of thyroidectomized rats were decreased by the supplementation of triiodothyronine (T3, 50 micrograms per kg, i.p. for 7 days) to levels similar to that observed in normal male rats. Hypophysectomy also caused an increase in microsomal P-450a content in male rats. Continuous infusion of human growth hormone, which mimicked the female secretion, further significantly increased the content in hypophysectomized rats to a level similar to that observed in normal female rats. In contrast, hepatic level of P-450a in hypophysectomized male and female rats was reduced by intermittent injection, which mimicked the male secretion. Clear suppression on the level of hepatic P-450a was also observed by the treatment of hypophysectomized rats with 5 or 50 micrograms/kg of T3 and of hGH-infused hypophysectomized rat with 50 micrograms/kg of T3.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cytostatic and growth-stimulating effects of alveolar macrophages of rats on tumor cells

Cytostatic and growth-stimulating effects of alveolar macrophages (AM) of rats on tumor cells were studied. The experimental results are summarized as follows. 1. The cytotoxicity of AM activated with BCG to tumor cells was increasing with the increase of effector cells/target cells (E/T) ratio. AM without the treatment with BCG expressed slight cytotoxicity to tumor cells at a high E/T, and growth-stimulating effect on tumor cells, at a low E/T. 2. AM after 24-hour culture had a lower manifestation of cytotoxicity to human lung adenocarcinoma cell line than that of AM without 24-hour culture, and had a growth-stimulating effect on B-16 cell line. 3. Cytostatic and growth-stimulating effects of AM without or with 24-hour culture were decreasing with the increase of irradiation doses.     

海岛碳排放核算与时空特征——以东山岛为例

把握地区碳信息发展动态是开展区域碳平衡规划的科学基础。以统计年鉴数据为基础,对东山岛2012—2021年整体及各产业的直接碳排放量进行核算,同时,将产业与土地利用结合,分析其空间表现形态,运用核密度分析和克里金法分析碳排放源的空间影响,采用高斯烟羽模型对工业点源的碳排放扩散进行空间模拟,通过渔网和人口修正的方法分析海岛碳排放的空间分异,以此探讨海岛碳排放的空间分布和空间影响特征。结果显示,工业是东山岛的首要碳排放源,2021年工业碳排放量的大幅下降表明能源种类的转换对于工业碳减排具有重要作用;渔业碳排放量总体占比25%左右,是海岛地区不容忽视的碳排放源之一。在空间分布方面,东山岛综合碳排放的空间分布呈“点状聚集,面状扩散”的基本特征,工业碳排放对周围地区的影响最大,往往形成以工业碳排放源点为中心的碳排放热点核心区,其次碳排放量较高的地区为人口聚集区,丘陵区的碳排放量最低,不同土地利用类型之间形成碳排放的交叉过渡区。最后,本文从碳排放空间影响的视角出发,根据不同形态的碳排放源提出“包围”、“伴随”和“介入”的碳汇空间规划策略,这对区域的低碳规划具有一定参考意义。     

DNASE1L3 inhibits proliferation,invasion and metastasis of hepatocellular carcinoma by interacting with β‐catenin to promote its ubiquitin degradation pathway

As a member of the deoxyribonuclease 1 family, DNASE1L3 plays a significant role both inside and outside the cell. However, the role of DNASE1L3 in hepatocellular carcinoma (HCC) and its molecular basis remains to be further investigated. In this study, we report that DNASE1L3 is downregulated in clinical HCC samples and evaluate the relationship between its expression and HCC clinical features. In vivo and in vitro experiments showed that DNASE1L3 negatively regulates the proliferation, invasion and metastasis of HCC cells. Mechanistic studies showed that DNASE1L3 recruits components of the cytoplasmic β‐catenin destruction complex (GSK‐3β and Axin), promotes the ubiquitination degradation of β‐catenin, and inhibits its nuclear transfer, thus, decreasing c‐Myc, P21 and P27 level. Ultimately, cell cycle and EMT signals are restrained. In general, this study provides new insight into the mechanism for HCC and suggests that DNASE1L3 can become a considerable target for HCC.

Decreased expression of DNASE1L3 is associated with poor prognosis in patients with HCC DNASE1L3 inhibits the proliferation and cell cycle of HCC cells in vitro and promotes the invasion and metastasis of HCC cells DNASE1L3 inhibits the tumorigenicity and metastasis of HCC cells in vivo DNASE1L3 interacts with β‐catenin and promotes its binding to the β‐catenin destroying complex DNASE1L3 interacts with P21 and stabilizes P21 by mediating the deubiquitin activity