Expression of p21ras-related protein in the plasma and tissue of patients with adenomas and carcinomas of the colon

Over-expression of p21 ras-related protein was determined in the plasma by immunoblotting and in the tissue by immuno-histochemistry in a cohort of patients undergoing colonoscopy. In the plasma samples, p21 ras over-expression was detected in: 9% (4/47) of normal controls; 21% (13/61) of individuals with normal colonoscopies but with a prior history of colonic neoplasia; 12% (4/33) of small adenoma patients, 29% (6/21) of large adenoma patients; 63% (5/8) of carcinoma-in-adenoma patients; 50% (2/4) of Dukes' A carcinoma patients; and 20% (2/10) of Dukes' B-D carcinoma patients. In the tissue samples, p21 ras over-expression was detected in: 25% (2/8) of small adenoma patients; 44% (4/9) of large adenoma patients; 100% (4/4) of carcinoma-in-adenoma patients; and 33% (1/3) of Dukes' B-C carcinoma patients. For matched plasma-tissue pairs, there was a statistically significant correlation for p21 ras over-expression (R = 0.47, p = 0.02).     

Uptake and metabolism of BuCast: a glycoprotein processing inhibitor and a potential anti-HIV drug

We have previously shown (Sunkara et al., 1989; Taylor et al.,1991) that 6-o-butanoyl castanospermine (BuCast) was a 30–50-foldbetter inhibitor of HIV syncytia formalion than castanospermine(Cast). Radiolabeled Cast and BuCast were used to study theuptake and metabolism of these compounds in cultured cells andin mice. BuCast was preferentially taken up by cells comparedto Cast. Approximately 30–50-fold higher radioactivitywas found in cells treated with BuCast compared to cells treatedwith Cast during the initial 4–6h of labeling. HPLC analysisshowed that once BuCast was taken up by cells, it was rapidlyconverted to Cast. Mice given oral doses of BuCast had 5–10-foldhigher levels of Cast in the plasma and tissues as comparedto Cast treated mice. However, when the compounds were giveni.v., the levels of plasma and tissue radioactivity obtainedfrom Cast or BuCast were equivalent suggesting rapid conversionof BuCast to Cast in the blood. In mice orally treated withBuCast, HPLC analysis suggested that only Cast was found inthe plasma and tissues. With multiple dosing of mice, additiveresults were obtained, suggesting that multiple doses may beused to obtain higher concentrations of the compound in thetarget cells. These data suggest that the lipophilic propertiesof butanoyl side chain on the Cast ring makes BuCast significantlybetter absorbed, and this may help to alleviate some of thegut toxicity associated with Cast treatment. HIV AIDS glycoproteins inhibitors     

The polyamine-derived amino acid hypusine: its post-translational formation in eIF-5A and its role in cell proliferation

Summary The unusual amino acid hypusine [N -(4-amino-2-hydroxybutyl)lysine] is a unique component of one cellular protein, eukaryotic translation initiation factor 5A (eIF-5A, old terminology, eIF-4D). It is formed posttranslationally and exclusively in this protein in two consecutive enzymatic reactions, (i) modification of a single lysine residue of the eIF-5A precursor protein by the transfer of the 4-aminobutyl moiety of the polyamine spermidine to its-amino group to form the intermediate, deoxyhypusine [N -(4-aminobutyl)lysine] and (ii) subsequent hydroxylation of this intermediate to form hypusine. The amino acid sequences surrounding the hypusine residue are strictly conserved in all eukaryotic species examined, suggesting the fundamental importance of this amino acid throughout evolution. Hypusine is required for the activity of eIF-5Ain vitro. There is strong evidence that hypusine and eIF-5A are vital for eukaryotic cell proliferation. Inactivation of both of the eIF-5A genes is lethal in yeast and the hypusine modification appears to be a requirement for yeast survival (Schnier et al., 1991 [Mol Cell Biol 11: 3105–3114]; Wöhl et al., 1993 [Mol Gen Genet 241: 305–311]). Furthermore, inhibitors of either of the hypusine biosynthetic enzymes, deoxyhypusine synthase or deoxyhypusine hydroxylase, exert strong anti-proliferative effects in mammalian cells, including many human cancer cell lines. These inhibitors hold potential as a new class of anticancer agents, targeting one specific eukaryotic cellular reaction, hypusine biosynthesis.     

癫痫对大鼠学习记忆的影响及与生长抑素的相关性研究

对听源性癫痫大鼠进行迷宫训练,观察癫痫发作对大鼠光分辨学习作业的成绩以及用放射免疫分析法测定的大鼠部分脑区中生长抑素含量的影响。结果表明：（１）癫痫发作对大鼠记忆阶段有明显的抑制作用（Ｐ＜０．０１）;（２）癫痫发作后,在大鼠信息提取明显障碍的同时,其颞叶皮层、下丘脑、垂体及海马中生长抑素的含量明显增加（Ｐ＜０．０５－０．０１）。结果提示：癫痫发作影响大鼠学习记忆过程,在该过程中生长抑素含量发生改变。     

北方稻田生态系统水量平衡及水分效率研究

１９９３～１９９５年研究了５种不同模式水稻田生态系统水量平衡及水分效率结果表明,不同水稻田模式其总耗水量之间有明显差异,其中节水模式和节水节肥模式较常规模式节省灌溉水达１５～２３％,水分生产效率增加３０％以上．各模式蒸发蒸腾耗水量在同一生长季内基本相同．田间结构及调控管理对其无明显影响实测水稻生育期田间蒸发蒸腾量与计算的可能蒸发蒸腾量相差不过５％。     

特种油料植物的种质资源研究

本文对特种油料植物的种质资源研究进行综述,这些植物包括含长链脂肪酸的Crambe,Limnanthes,Lunaria,短链脂肪酸的Cuphea,Lauraceae,羟基脂肪酸的Lesquerella,环氧脂肪酸的Vernonia,Stokesia,以及液体蜡酯的simmondsia等科、属的植物。     

硫酸盐还原一甲烷化两相厌氧消化系统运行工艺条件的研究

以合成废水为基质,研究了采用硫酸盐还原-甲烷化两相厌氧新型工艺处理含高浓度硫酸盐有机废水的系统运行工艺条件.结果表明,酸化-硫酸盐还原反应器的适宜pH为6.5-7.0;500mg/l的S~(2-)使SRB的硫酸盐还原活性下降;208mg/l的[H_2S]_L抑制MPB活性的95.4%;推导出估算气提塔出水回流比R的模型;以得到的工艺条件为依据处理了含19200mg/1的SO_4~(2-)和29400mg/l COD的味精废水.     

低能量He—Ne激光血管内照射治疗脑血栓形成35例临床观察

本文报道了用低能量Ｈｅ—Ｎｅ激光血管内照射治疗脑血栓形成３５例,与常规药物治疗组３０例对照,结果表明治疗组明显优于对照组（Ｐ＜０．０５）,二者有显著性差异．     

重组人白细胞介素－2在离子色谱分离时的复性

采用ＨＰＩＥＣ应用ＣＭ交换柱分离纯化Ｅ．ｃｏｌｉ工程菌表达的ｒＩＬ－２,与空气氧化复性相比较,又有１倍以上的变性ｒＩＬ－２在色谱过程中得到复性,且溶液ｐＨ影响ｒＩＬ－２的复性和纯化效果：ｐＨ７．０时ｒＩＬ－２复性率高于ｐＨ８．０时,但纯度明显低于ｐＨ８．０时分离的ｒＩＬ－２．     

Rapid recovery of photosynthetic cell suspension cultures following heterotrophic bleaching

Summary Seven suspension-cultured lines of five different species (Amaranthus powellii Datura innoxia, Glycine max, Gossypium hirsutum, andNicotiana tabacum × Nicotiana glutinosa fusion hybrid), which had been grown under photomixotrophic conditions, were placed under heterotrophic conditions (darkness and media with 3% sucrose or starch) where the chlorophyll levels declined to near zero. After three transfers over a 70-d period, the cells were placed back into photomixotrophic or photoautotrophic conditions where regreening occurred rapidly and continued growth was observed. This rapid adaptation to photosynthetic conditions contrasts with the original initiation process for these cultures, which required many months and an apparent selection since many of the original cells died. Thus, these seven photosynthetic cell suspension cultures appear to be different from the original cultures due possible to genetic or adaptive changes.