两种穗型冬小麦品种旗叶光合特性和水分利用对光强的响应

以超高产小麦兰考矮早八和豫麦49为材料,研究了开花期旗叶光合与水分利用对光强的响应。结果表明:开花期,随着光强的增加,旗叶光合速率(Pn)、气孔导度(Cond)、蒸腾速率(Tr)和水分利用率(WUE)均表现不同程度增大,超过一定的光强后反而下降;但胞间CO2浓度(Ci)随光强的增加而降低。与豫麦49相比,兰考矮早八在较高光强下旗叶仍表现出较高的光合特性与水分利用。     

苦瓜MAP30基因的克隆与载体构建

首先提取苦瓜的基因组DNA,然后根据Genbank中已公开发表的MAP30序列,设计一对特异引物MAP301,MAP302,并增添特异定位于内质网的小肽Kozak序列。采用PCR技术,从苦瓜的基因组DNA中扩增出一分子量为800bp左右的片段,回收克隆测序,结果表明,克隆获得片段与已公开发表的MAP30序列同源性达100%,将阳性克隆进行酶切,获得的目标片段与用同样酶切所获得的植物表达载体pEV1和pEV2大片段连接,酶切鉴定重组子构建成特异表达于果实的载体。     

小球藻水环境毒理学研究进展及应用前景

小球藻作为水体中的初级生产者,是水生生态系统不可或缺的一部分,对促进物质循环、能量流动有着重要意义,同时也是水环境毒理学评价的标准试验藻种。为了给小球藻的水生态风险评估及相应产品的开发提供参考数据,本文系统分析了小球藻培养影响因素,概括了其产生的毒理效应,并对其营养价值与应用前景等进行了综述。本文认为温度、光照、pH、营养盐、氮磷比是小球藻规模化培养过程中的影响因素,重金属、农药、新型纳米材料、抗生素等污染物可对小球藻产生毒性效应,小球藻在污水处理、生物能源等领域具有较好的应用前景。     

Change of synapsins in hippocampal formation during spacial learning and memory in rats

AIM and METHODS: The immunohistochemical method was used to study the on synapsin express in hippocampal formation during spatial learning and memory in rats.RESULTS: (1) In control group there are diffuse brown granules without any obvious granular product in hippocampal formation and in model group there are synapsin products in the hippocampal formation ,especially in the subregion CA3 , CA4 and the dentate gyrus after water maze trained for one week. After two weeks water maze trained the hippocampal formation appear the same distribution of the product granules with darker staining. (2) The light dendity of synapsin products between the model and the control groups showed significant differences, that in the model group was highter than that in the control group (P＜0.05). The light dendity of synapsin products increased with the training time from the first week to the second week in the model group. And there is no increase with the training time from the second week to the third week . The light dendity is higher in the CA3, CA4 subregion and the dentate gyrus than the CA1 and CA2 subregion (P＜0.05).CONCLUSIONS: (1) As mentioned above, it is believed that the new synapes are formed in the hippocampal formation of the rat by spacial learning and memory training. (2) The CA3, CA4 subregion and the dentate gyrus are correlated with the spacial learning and memory.     

Inducible nitric oxide synthase and arterial pressure regulation

AIM and METHODS:To clarify the role of inducible nitric oxide synthase (iNOS) in the regulation of blood pressure,in the present study, we examined the effect of aminoguanidine (AG), a selective inhibitor of iNOS on the hemodinamical response of Dahl salt-sensitive (DS) and Dahl salt-resistant (DR) rats to low (0.3%) or high (8%) sodium chloride (NaCl) infusion by chronical in vivo hemodynamic experiment, and the effect of NaCl or NaCl plus AG infusion on urinary nitrate (NO₃)/nitrite (NO₂), the end product of nitric oxide (NO), excretion by Greiss Reaction. Furthermore, NOS activity assay was also carried out to probe the effect of NaCl and AG on calcium-dependent or independent NOS activity in renal tissue. RESULTS:1. High or low NaCl-infused DR rats and low NaCl-infused DS rats have no hemodinamical response to AG, however, the hypertensive effect of high NaCl (8%) infusion on DS rats were greatly amplified by co-infusion of AG. 2. Administration of high NaCl significantly elevated the iNOS activity of renal tissue, and greatly increased urinary NO₃/NO₂ excretion. CONCLUSION:Inducible NOS is an important modulator of arterial pressure, especially in case of higher blood pressure.     

Effect of 2, 3-butanedione monoxime (BDM) on myocardial protection in cold cardioplegia

AIM: The effects of BDM on isolated rat heart in cold cardioplegia were studied. METHODS: Rat heart were subjected to cold cardioplegia at 4℃ for 8, 18 and 24 h.Then each heart was perfused (90 cm H₂O) in Langendorff model at 37℃ for 40 min. In the high K⁺ group(n=24) the hearts were preserved in St.Thomas cardioplegic solution, in BDM group(n=24) hearts were preserved in K-H solution with BDM 30 mmoL/L. RESULTS: After 18 h, heart rate and the coronary flow in BDM group were significantly higher than in high K⁺ group(P＜0.05). Activity of Na⁺-K⁺-ATPase in cell membrane and in mitochondrial membrane in the BDM group was significantly higher than high K⁺ group(P＜0.01). After 24 h, all hearts in high K⁺ group were dead, but were alive in BDM group. CONCLUSION: Under given experiment conditions, BDM did enhance the tolerance to cold ischemia significantly. The results showed that BDM may become a useful agent for prolong the storage period of heart in cold cardioglegia.     

Interleukin-1β inhibits AKT to down-regulate eNOS Ser1177 phosphorylation in human umbilical vein endothelial cells

AIM To investigate whether interleukin-1β （IL-1β） regulates endothelial nitric oxide synthase （eNOS） phosphorylation at Ser1177 site in human umbilical vein endothelial cells （HUVECs）, and to explore its possible mechanism. METHODS The HUVECs were randomly divided into normal control group, tumor necrosis factor-α （TNF-α） group, IL-1β group, IL-6 group, SC79 ［protein kinase B （PKB/AKT） specific agonist］ group and SC79+IL-1β group. Western blot was used to determine the protein levels of eNOS, p-eNOS-Ser1177, AKT and p-AKT-Ser473 in the HUVECs. Chemical colorimetry was used to detect the nitric oxide （NO） content in the culture medium of HUVECs. RESULTS No statistically significant difference of p-eNOS-Ser1177 level in HUVECs treated with TNF-α and IL-6 was observed as compared with normal control group （P>0.05）, while the protein level of p-eNOS-Ser1177 in the HUVECs and the content of NO in the culture medium of HUVECs decreased significantly in IL-1β group （P<0.05）, and the protein level of p-AKT-Ser473 in the HUVECs was decreased as compared with normal control group （P<0.05）. The AKT agonist SC79 blocked the down-regulation effect of IL-1β on p-eNOS-Ser1177 level in the HUVECs and NO content in the culture medium of HUVECs （P<0.05）. CONCLUSION IL-1β down-regulates the protein level of p-eNOS-Ser1177 in HUVECs and affects the activity of eNOS, which may be involved in AKT/eNOS signaling pathway.     

Dihydroartemisinin enhances radiotherapy efficiency in H22 cell tumor-bearing mice by regulating PI3K/AKT signaling pathway

AIM To study the effect of dihydroartemisinin （DHA） on the radiotherapy efficiency in hepatocellular carcinoma H22 cell tumor-bearing mice and the role of phosphatidylinositol 3-kinase （PI3K）/protein kinase B （AKT） signaling pathway in this process. METHODS A model of H22 cell tumor-bearing mice was established. The mice was divided into model group, single radiotherapy group, 5-fluorouracil （5-FU） group, and low-, medium- and high-dose DHA groups. The body weight and tumor volume in each group were measured every other day. At the end of administration, blood was collected from the tail of the mice and the animals were killed by neck removal immediately. The synergistic effect of DHA on radiotherapy was determined, and tumor growth inhibitory rate was calculated. The degree of lymphocyte transformation and natural killer （NK） cell activity were measured by MTT, the serum levels of interleukin-2 （IL-2） and IL-4 were measured by ELISA, and the protein levels of PI3K, AKT and p-AKT were determined by Western blot. RESULTS The H22 cell tumor-bearing mouse model was successfully constructed. Compared with model group, the TGT₃ （tumor growth time to reach 3 times of volume） of single radiotherapy group was remarkably increased （P<0.05）, while tumor weight, lymphocyte transformation degree, NK cell activity, IL-2 and IL-4 levels, PI3K protein level and AKT phosphorylation level were remarkably decreased （P<0.05）. Compared with single radiotherapy group, TGT₃, EF （enhancement factor）, tumor inhibitory rate, lymphocyte transformation degree, NK cell activity, IL-2 level and IL-4 level were increased with the increase in DHA dose （P<0.05）, and the PI3K protein level and AKT phosphorylation level were decreased （P<0.05）. CONCLUSION DHA may enhance the immunity of tumor-bearing mice by inhibiting the activity of PI3K/AKT signaling pathway, thereby enhancing the efficacy of radiotherapy.     

Effects of swimming on experimental endometriosis in rats

AIM To evaluate the effect of swimming on experimental endometriosis in rats. METHODS 80 female SD rats were divided into 8 groups, including control group, model group and animals performed light exercise （swimming once a week）, moderate exercise （swimming 3 times a week）, and intense exercise （swimming 5 times a week） before or after endometriosis induction,10 rats in each group. The mRNA and protein expressions of fatty acid synthase （FAS）, matrix metalloproteinase 9 （MMP9） and proliferating cell nuclear antigen （PCNA） in endometrium of rats were detected. RESULTS The swimming before the induction of the edometriosis lesions did not prove to have aprophylactic role against endometriosis, whereas the swimming after induction of the lesions had a beneficial effect regardless of frequency, with a greater reduction in the groups practicing moderate and intense activity （P<0.05）, an increase in FAS levels and a decrease in MMP9 and PCNA levels were also observed （P<0.05）. CONCLUSION Swimming after induction of the edometriosis is beneficial for the treatment of endometriosis, the mechanism may be related to the expression of FAS, MMP9 and PCNA protein.     

海湾泥碱渣和粉煤灰作为园林种植基质的氮素生理类群及生化作用研究

海湾泥、碱渣和粉煤灰是天津滨海地区大量存在的固体废弃物,通过前期室内配比筛选、盆栽试验、田间试验表明其混合基质可以用于园林绿化,并在防护林建设中获得成功.以滨海盐土、客土绿地为对照,对通过脱盐、培肥、种植毛白杨、刺槐、洋白蜡、金银木、紫花苜蓿等园林植物后基质的氨化细菌、好气性自身固氮菌、硝化细菌、反硝化细菌、纤维素分解菌等土壤氮素生理类群的数量进行了研究,同时对呼吸作用、氨化作用强度以及二者与土壤微生物数量、理化性质进行了相关性分析.结果表明,基质的氮素生理类群数量高于或与客土绿地相当,明显高于滨海盐土.呼吸作用高于客土绿地和滨海盐土,氨化作用强度与客土绿地相当,说明混合基质的氮素转化、有机物质的矿化能力以及基质整体的代谢水平好于客土绿地.土壤呼吸作用强度与土壤盐分呈极显著负相关,与细菌数量呈显著正相关.氨化作用强度与全氮、全磷、有机质含量、细菌和真菌数量呈极显著正相关,与放线菌呈显著正相关,与速效钾、盐分呈显著负相关.