The ATM kinase signaling induced by the low-energy β-particles emitted by (33)P is essential for the suppression of chromosome aberrations and is greater than that induced by the energetic β-particles emitted by (32)P

Ataxia-telangiectasia mutated (ATM) encodes a nuclear serine/threonine protein kinase whose activity is increased in cells exposed to low doses of ionizing radiation (IR). Here we examine ATM kinase activation in cells exposed to either (32)P- or (33)P-orthophosphate under conditions typically employed in metabolic labelling experiments. We calculate that the absorbed dose of IR delivered to a 5cm×5cm monolayer of cells incubated in 2ml media containing 1mCi of the high-energy (1.70MeV) β-particle emitter (32)P-orthophosphate for 30min is ～1Gy IR. The absorbed dose of IR following an otherwise identical exposure to the low-energy (0.24MeV) β-particle emitter (33)P-orthophosphate is ～0.18Gy IR. We show that low-energy β-particles emitted by (33)P induce a greater number of ionizing radiation-induced foci (IRIF) and greater ATM kinase signaling than energetic β-particles emitted by (32)P. Hence, we demonstrate that it is inappropriate to use (33)P-orthophosphate as a negative control for (32)P-orthophosphate in experiments investigating DNA damage responses to DNA double-strand breaks (DSBs). Significantly, we show that ATM accumulates in the chromatin fraction when ATM kinase activity is inhibited during exposure to either radionuclide. Finally, we also show that chromosome aberrations accumulate in cells when ATM kinase activity is inhibited during exposure to ～0.36Gy β-particles emitted by (33)P. We therefore propose that direct cellular exposure to (33)P-orthophosphate is an excellent means to induce and label the IR-induced, ATM kinase-dependent phosphoproteome.     

扬子鳄胚胎胰腺内分泌细胞发生的免疫组织化学研究

目的 研究13种特异性激素在扬子鳄胚胎胰腺早期发育中的表达。方法 应用免疫组织化学方法。结果 显示生长抑素（SS）,5-羟色胺（5-HT）,胰高血糖素（GLU）,表皮生长因子（EGF）,胰多肽（PP）免疫反应性（IR）细胞出现于第8天,P物质（SP）IR细胞出现于第18天,P53,胃泌素,睾酮,嗜铬素A,血管活性肠肽,上皮膜抗原,胰岛素在各期扬子鳄胚胎胰腺中均未发现。结论 表明SS、5-HT,GLU,EGF、PP和S害扬子鳄胚胎胰腺形成的分化的不同阶段发挥着重要作用。     

褐飞虱致害性变异过程及其体内酶的变化

在室内连续用具不同抗虫基因的水稻品种TNl、IR26、Mudg。和ASD7、单管饲养褐飞虱(Nilaparvata lugens)种群,研究它对抗虫水稻品种的适应过程及其体内酶的变化规律。 结果表明：褐飞虱在抗虫品种上取食2代的若虫存活率、若虫历期和短翅成虫体重均明显比取食感虫品种TNl的低,第3代以后与取食TNl者基本相同。第2代是褐飞虱适应抗虫品种的关键期。天冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)和丁-谷氨酰基转移 酶(GGT)的活性在关键的第2代最低,而超氧物歧化酶(SOD)和过氧化氢酶(CAT)的含量增加。褐飞虱在适应抗虫品种以后体内天冬氨酸氨基转移酶活性明显提高。     

地塞米松对大白鼠海马兴奋性神经元和抑制性神经元的影响

为了探讨糖皮质激素对海马兴奋性神经元和抑制性神经元的作用,本实验将地塞米松注入大白鼠侧脑室,２ｈ 后经Ｎｉｓｓｌ染色法、免疫组织化学方法和细胞计数法观察了海马谷氨酸免疫反应性（ＧｌｕＩＲ）神经元和γ氨基丁酸免疫反应性（ＧＡＢＡＩＲ）神经元的变化。结果显示：（１）ＣＡ１、ＣＡ３ 和ＳＧ区的ＧｌｕＩＲ神经元明显增多,特别是ＣＡ１ 区。经细胞计数统计分析表明,与对照组相比ＣＡ１ 有极显著性差异（Ｐ＜ ０００１）,ＣＡ３区有显著性差异（００１＜ Ｐ＜ ００５）,ＳＧ处无明显差异（Ｐ＞ ００５）。（２）与对照组相比,ＧＡＢＡＩＲ神经元无明显变化。结果表明,糖皮质激素有增加海马谷氨酸能神经元的作用。尽管γ氨基丁酸能神经元无明显变化,并不表明糖皮质激素对其无影响     

长江中游长吻鮠、蛇鮈寄生粘孢子虫感染率的季节动态

1.寄生长吻鮠上的粘孢子虫有3种:巨囊两极虫和四极虫一种,寄生在胆囊中,碘泡虫一种寄生在肾脏中;寄生蛇鮈上的粘孢子虫有2种:湖北碘泡虫,寄生在脑、鳃、肾、体腔、肠,主要寄生在脑,楚克拉虫一种,寄生在胆囊中。2.粘孢子虫对长吻鮠、蛇鮈的感染率存在明显的季节变化;对长吻鮠的感染率最高值出现在6月(95%),最低值出现在2月(43%),年平均值为65%;湖北碘泡虫对蛇鮈的总感染率最高值出现在12—2月(63—67%),其次在8月(58%),春秋两季感染率较低(36—44%),年平均值为51%。3.总感染率(IR)与鱼体全长(TL)的关系:长吻鮠IR=0.956-0.009TL;蛇鮈IR=-2.0678+0.3838(TL)-0.0136(TL)2,8厘米以下的蛇鮈未发现感染。4.粘孢子虫的感染率与长吻鮠、蛇鮈的性别无关。5.感染粘孢子虫的长吻鮠,肥满度下降不大(0.04),感染粘孢子虫的蛇鮈,肥满度下降0.12,体重平均下降12.4%。6.长吻鮠中寄生粘孢子虫的总感染率(IR)与长江中游水温(T℃)呈显著正相关,二者关系可用下式描述:IR=0.3129+0.0192(T℃)。蛇鮈寄生粘孢子虫的总感染率(IR)与水温(T℃)之间的关系呈一反抛物线型、两者关系可用下式描述 IR=1.1228-0.073777T+0.001795T2       

Interaction of PTPB with the insulin receptor precursor during its biosynthesis in the endoplasmic reticulum

PTP1B is a protein tyrosine-phosphatase predominantly located on the cystosolic surface of the endoplasmic reticulum. This tyrosine-phosphatase plays a major role in the regulation of the activity of the insulin receptor (IR). We have studied the interaction of the IR with PTP1B in living cells using bioluminescence resonance energy transfer (BRET). The IR was fused to Renilla luciferase and a substrate-trapping mutant of PTP1B was fused to the yellow variant of the green fluorescent protein (YFP). When the two partners interacted, an energy transfer occurred between the luciferase and the YFP, and a fluorescent signal, emitted by the YFP, could be detected. The interaction of the IR with PTP1B could be monitored in real time for more than 30 min. Insulin rapidly and dose-dependently stimulated this interaction. The basal (insulin-independent) interaction of IR with PTP1B was much lower with a soluble form than with the endoplasmic reticulum-targeted form of PTP1B, indicating that this basal interaction mainly occurred in the endoplasmic reticulum. In the basal state, PTP1B and the IR indeed co-localized in the endoplasmic reticulum, as demonstrated by confocal microscopy and cell fractionation experiments. Moreover, inhibition of IR processing with tunicamycin indicated that the basal interaction of PTP1B with IR occurred during biosynthesis of the IR precursor in the endoplasmic reticulum. These results strongly suggest that PTP1B not only dephosphorylates the insulin receptor that has been activated by insulin, but also regulates the insulin receptor precursor during its biosynthesis. Localisation of PTP1B to the endoplasmic reticulum may be important to prevent insulin-independent autonomous activity of the immature insulin receptor precursor.     

地塞米松对哮喘豚鼠肺内VIP分布的影响

为探讨哮喘豚鼠肺内血管活性肠肽（ＶＩＰ）的分布及地塞米松对其分布的影响,将豚鼠随机分成哮喘组、地塞米松组和对照组三组,采用兔抗ＶＩＰ多克隆血清,免疫组织化学ＡＢＣ法和葡萄糖氧化酶－ＤＡＢ－镍染色技术,发现对照豚鼠肺内各级气道壁均可见ＶＩＰ免疫反应（ＶＩＰ－ＩＲ）阳性纤维分布。在平滑肌层中,纤维成束走行,且有较多分枝;而在基底膜和气道上皮内,纤维成单根行走。随气道口径的变小,纤维分布密度也逐渐变小。哮喘豚鼠肺内ＶＩＰ－ＩＲ消失。地塞米松处理后使ＶＩＰ－ＩＲ部分恢复。上述结果提示,豚鼠经反复抗原攻击后,肺内ＶＩＰ－ＩＲ阳性纤维消失,这在实验性哮喘的发生过程中可能起一定作用。     

蝎毒对癫痫敏感性和海马GFAP释放的影响

目的和方法 :本工作用海人酸癫痫模型 ,通过对癫痫大鼠蝎毒治疗后行为变化及脑内胶质原纤维酸性蛋白(GFAP)免疫反应活性的检测 ,对蝎毒抗癫痫反复发作的相关脑区及其机制做以初步探讨。结果 :癫痫大鼠蝎毒治疗三周后 ,能明显减少癫痫发作的例数 ,减轻癫痫发作的程度 ,使发作的潜伏期延长 (P <0 .0 5 )。免疫细胞化学的实验显示 ,蝎毒抗癫痫反复发作的相关脑区是海马。 8例蝎毒治疗的大鼠与实验对照组相比 ,有 6例背侧海马GFAP免疫染色明显减轻 ,未见星形胶质细胞增生 ;CA1区无明显神经元缺失 ;而且与空白对照组相比无显著差异。结论 :癫痫大鼠蝎毒治疗三周后 ,能明显减轻癫痫发作的行为 ,抑制海马星形胶质细胞的增生肥大 ,减轻海马神经元受损的程度。蝎毒抑制海马星形胶质细胞增生很可能是蝎毒抗癫痫反复发作的重要机制之一。     

枯盘斑多毛孢Pf-毒素组分的研究I.活性组分I的结构分析

以正丁醇:水:甲醇(4:2:1)作洗脱剂,通过硅胶H60型柱反复柱层析,将3种有致病活性的物质充分纯化,在-40℃下冷冻干燥后,它们为褐色深浅不一的蓬松状物质,且极易吸潮。活性组分I(Rf0.83)、活性组分II(Rf0.79)和活性组分III(Rf0.80)对马尾松切根幼苗和湿地松切根幼苗针叶都有致萎作用,通过质谱(MS)、核磁共振谱(1HNMR、)和红外光谱(IR)等分析手段确定出所分离的活性组分I的化学组成为C5H11O5N(M=165)。     

低pH对水稻黄化叶片硝酸还原酶活性暗诱导的调节

在低pH条件下,水稻离体黄化叶片的硝酸还原酶(NR)活性能在暗中诱导产生,其诱导过程约有2h的滞后期,亚胺环已酮(CHI,5ppm)和Na_2WO_4(25 mmol/L)能完全抑制这种诱导作用。在最适pH 3.0时,H~3标记氨基酸掺入NR的量比pH 7.0时约高2倍,表明酶活性的产生与酶蛋白的重新合成有关。 当低pH暗诱导时,BA(5ppm)和ABA(15ppm)能使酶活性分别提高约30％和80％,但它们都不能取代低pH在NR活性暗诱导中的作用。当存在1ppm CHI的时候,BA仍促进NR活性,而ABA则加强CHI对酶活性的抑制作用,这提示BA与ABA在低pH暗诱导条件下促进NR活性的机制是不同的。在pH 7.0的光诱导条件下,ABA对NR活性起抑制作用。     

ANALYSIS OF THE Vitellogenin GENE OF RICE MOTH,Corcyra cephalonica STAINTON

Vitellogenin (Vg) is a precursor of the major yolk protein, an essential nutrient for the embryonic development of oviparous animals including insects. Here, the gene(CceVg [Corcyra cephalonica Vg] ) encoding the Vg (CceVg of moth, C. cephalonica, was cloned and sequenced. The gene sequence was 6,721‐bp long and contained 5five introns and six exons that together formed a 5,382‐bp open reading frame. The deduced protein (CceVg) consisted of 1,793 amino acid residues, including a 16‐amino‐acid signal peptide. The putative molecular weight of the primary Vg protein was 202.46 kDa. The CceVg contained all conserved domains and motifs that were commonly found in most insect Vgs except the presence of a polyserine tract at the C‐terminal region, which had not been reported in other lepidopteran Vgs. The expression pattern showed thatCceVg was first transcribed at a very low level in the early larval stage but disappeared in later stage larva. In female, theCceVg mRNA was detected in early pupal stage and throughout adult stage. Interestingly, theCceVg mRNA was detected only in mated males at low levels, not in the virgin ones. Injection ofCceVg double‐stranded RNA into early‐emergent females caused severely abnormal ovaries.     

STUDIES ON THE AMOUNT OF LIGHT EMITTED BY MIXTURES OF CYPRIDINA LUCIFERIN AND LUCIFERASE

1. A photometric method was devised for measuring the intensities of light emitted per cc. of hiciferin solution and calculating the amount of light emitted per gm. of dried Cypridina powder. A total of 128 runs was made and the data are incorporated in this report. 2. The maximum amount of light emitted from 1 gm. of powder under the experimental conditions was 0.655 lumens. Different samples of powder vary greatly in amount of light production. 3. When the concentration of substrate is doubled, nearly twice as much light is emitted, or an average ratio 2C/C of 1.86. Calculations of total light emissions per gm. of powder at different concentrations indicate that slightly more light is produced from the smaller concentrations. The maximum amount of light was produced by the solutions made with neutral sea water and averaged 0.445 lumens. The least light was obtained from solutions in distilled water saturated with hydrogen. The technique allows too rapid spontaneous oxidation prior to the saturation with hydrogen. The maximum amount of light from such experiments was only 0.077 lumens. Acid sea water solutions subsequently neutralized gave an average maximum of 0.386 lumens per gm. of powder per second. 4. When the concentration of enzyme is doubled, approximately the same amount of light is produced by both concentrations, although the stronger concentrations are slightly less effective than weaker ones. This undoubtedly is due to the colloidal nature of the enzyme and is a function of surface rather than of mass. In dilute solutions greater dispersion probably allows for greater adsorption to the surface of the enzyme. The average maximum amount of light produced in the series of enzyme experiments is of the magnitude 0.56 lumens per gm. of powder.     

异丙肾上腺素对心内神经节中肽能递质VIP影响

异丙肾上腺素是临床常用的心脏骤停的抢救药物。为了研究该药对心内神经节中肽能递质的影响,本文在大鼠皮下注射异丙肾上腺素５ｍｇ／ｋｇ,连续三天,后固定取心房后壁,用免疫组化结合图像分析,观察心内神经节中肽能递质ＶＩＰ的变化。对照组大鼠心内神经节中含有ＶＩＰ免疫反应（ＶＩＰ－ＩＲ）阳性神经纤维和胞体;实验组大鼠心内神经节中含有ＶＩＰ－ＩＲ阳性神经纤维和胞体呈不同程度增多。其中ＶＩＰ－ＩＲ阳性神经纤维积分光密度较对照组增加２５．３％,而神经胞体积分光密度只增加８．１％。结果提示：１．大鼠心内神经节中ＶＩＰ－ＩＲ阳性神经纤维可能有两个来源：即心内ＶＩＰ－ＩＲ阳性神经节细胞和心外副交感神经元;２．异丙肾上腺素对心脏的作用并非单一的直接作用,其中部分是通过影响心内神经节中肽能递质的变化而发挥间接作用。     

THE VIRULENCE CHANGE AND DAMAGE CHARACTERISTICS OF VARIOUS GEOGRAPHIC POPULATIONS OF BROWN PLANTHOPPER*

Abstract The virulence change and damage characteristics of brown planthopper (BPH), Nilaparvata lugens Stal, populations collected from Guangxi, Yunnan and Zhejiang Provinces were studied by using various resistant rice varieties. The results indicated that the Zhejiang population could successfully infest varieties IR26 and Mudgo, showing the characters of BPH biotype 2 after 1989. The Guangxi population, however, could adapt the resistant varieties IR26, Mudgo and ASD7 after 1991. In 1997, the nymphal survival indices of Guangxi and Yunnan populations on Rathu Heenati (Bph3) were up to 70. 9 and 66. 7 respectively. This may imply that the BPH populations in Guangxi and Yunnan have shifted into a new biotype. In free-choice test, there was obvious difference in the feeding preference of nymphs and adults of Zhejiang population, the adult preferred to feeding on resistant variety IR26 and the nymphs chose the hosts randomly. Under 26 C and L12: D12, the nymphal duration of Zhejiang population was the longest in the three tested populations. For Guangxi population, the nymphal duration on ASD7 was significantly longer than on TN1, although it could infest resistant variety ASD7. The nymphal survival rate of Zhejiang population fed on IR26 was higher than those fed on TN1 and ASD7. On varieties IR26 and ASD7, an obviously higher nymphal survival rate was observed in Yunnan population as compared to those of Zhejiang and Guangxi populations. These results indicate that difference in virulence and damage characteristics could be found in different geographical populations of BPH.     

浙江山萆薢甾体皂甙的研究

从山萆薢根茎分到6个甾体皂甙,通过乙酰化、酸水解,红外、质谱和碳谱等鉴定,分别为约诺皂甙(A),薯蓣皂甙(C),纤细皂甙(D),原薯蓣皂甙(E),原纤细皂甙(F);皂甙 B 因得率极低,未能完成鉴定。     

CCK—8、M—ENK免疫反应结构在猫延髓吻侧腹侧区的分布

用免疫组化 ABC 技术,观察了八肽缩胆囊素(CCK—8),甲硫氨酸脑啡肽(M—ENK)免疫反应(IR)结构在猫延髓吻侧腹侧区的分布。结果表明:CCK—8—IR 细胞分内、外两群:内侧群细胞分布于巨细胞网状核(NGc)、旁巨细胞外侧核(PGL)以及下橄榄核背外侧的网状结构,从吻侧向尾侧逐渐减少;外侧群细胞分布于外侧网状核(LRN)及其背内侧网状结构,从吻侧向尾侧逐渐增多。在中缝苍白核(Rpa)、中缝大核(Rm)仅见少量 CCK—8—IR 细胞。察见 CCK—8—IR纤维主要有3种:粗、细和终末前纤维。CCK—8—IR 纤维在面后核、疑核以及二核紧邻的网状结构最为密集;在 PGL 密度中等;在 NGc、LRN、Rpa 和 Rm 稀疏分布。M—ENK—IR 细胞和纤维分布于 Rpa、Rm、NGc、PGL 和 LRN,此外在面后核、疑核以及二核紧邻的网状结构可见较密集的纤维。     

SOLVING THE PARADOX OF STASIS: SQUASHED STABILIZING SELECTION AND THE LIMITS OF DETECTION

Despite the potential for rapid evolution, stasis is commonly observed over geological timescales—the so‐called “paradox of stasis.” This paradox would be resolved if stabilizing selection were common, but stabilizing selection is infrequently detected in natural populations. We hypothesize a simple solution to this apparent disconnect: stabilizing selection is hard to detect empirically once populations have adapted to a fitness peak. To test this hypothesis, we developed an individual‐based model of a population evolving under an invariant stabilizing fitness function. Stabilizing selection on the population was infrequently detected in an “empirical” sampling protocol, because (1) trait variation was low relative to the fitness peak breadth; (2) nonselective deaths masked selection; (3) populations wandered around the fitness peak; and (4) sample sizes were typically too small. Moreover, the addition of negative frequency‐dependent selection further hindered detection by flattening or even dimpling the fitness peak, a phenomenon we term “squashed stabilizing selection.” Our model demonstrates that stabilizing selection provides a plausible resolution to the paradox of stasis despite its infrequent detection in nature. The key reason is that selection “erases its traces”: once populations have adapted to a fitness peak, they are no longer expected to exhibit detectable stabilizing selection.     

蓣知子的化学成份研究（Ⅲ）

从木通科木通属植物白木通[Akebia trifolinta (Thunb.) Koidz. var. australis(Dies)Rehd]的种子(蓣知子)抗肿瘤活性的乙醇提取物中以硅胶层析等方法分得一种三萜皂甙。经波谱分析及酸碱水解确定了其化学结构,命名为:3-O-α-L-吡喃阿拉伯糖常春藤皂甙元-28-O-β-D吡喃葡萄糖-(1→6)-β-D-吡喃葡萄糖甙(即Saponin D),为首次自该植物中获得。     

心房利钠肽样免疫反应神经元在大鼠中脑和脑桥中某些锥体外系神经核内的分布

采用PAP免疫组织化学方法对大鼠中脑和脑桥内心房利钠肽(ANP)样免疫反应神经元的分布进行了研究,结果显示阳性神经元除存在于其他作者报导过的导水管周围灰质、Edinger-Westphal核、中缝核、脚间核和蓝斑核外,还存在于属于锥体外系的红核、黑质和脑桥核内,因此,推测脑内的ANP可能在锥外系对躯体运动的调节中起着一种神经递质或神经调质的作用。这为脑内ANP可能具有与液体和电解质平衡以及心血管功能的调节无关的其它作用提供了部分形态学证据。     

CHARACTERIZATION OF THE MAIN PHASE TRANSITION IN 1,2-DIPALMITOYL-PHOSPHATIDYLCHOLINE LUVS BY 1H NMR*

ABSTRACT

The main phase transition (Tm) of 100 nm large unilamellar vesicles (LUVs) of 1,2-dipalmitoylphosphatidylcholine (DPPC) was investigated using ¹H NMR (proton magnetic resonance) in deuterium oxide, and both DSC (differential scanning calorimetry) and IR (infrared) spectroscopy in water and deuterium oxide. The ability of ¹H NMR to determine Tm was demonstrated and the values obtained were in general agreement with those observed with DSC and IR. However, the temperature range of the transition observed by NMR was significantly broader than that observed with either DSC or IR. The effect of deuterium oxide on Tm was studied by comparing results obtained in water and deuterium oxide with DSC and IR. The results showed no significant difference in Tm or temperature range of transition determined in these solvents.