Differences in the antigenic structure of chromatin from the liver and hepatoma cells in the rat

Differences in antigenic structure of chromatin from normal and tumour cells were studied using rabbit antibodies against chromatin of the rat liver, Zaidela ascite hepatoma and solid hepatoma 27 cells. It is shown that carcinogenesis is accompanied by loss of a part of normal liver antigens. All the antigens which are not indicated in solid hepatoma were not detected in ascite tumour too. The latter is deficient in some antigens common for the normal liver and solid hepatoma cells. Chromatin of both hepatomas contains antigens which are not detected in liver chromatin. Hepatoma 27 contains also antigens detected in this tumour only. At least some antigens of tumour cells are not found in regenerating liver and in liver cells of newborn rats. Antigenic properties of liver cells chromatin in old (30 months) rats approach to those of hepatoma cells chromatin.     

黄金树核内包涵体的研究

应用透射电镜技术研究了黄金体叶芽和根尖细胞中的核内包涵体。观察发现在薄壁组织、保护组织及输导组织的细胞中，都普遍存在核内包涵体。刚分裂后的幼小细胞中的核内包涵体为纤丝状结构，而在成熟的细胞中则主要是大块的片层状结构。我们对梓树属植物的研究证明，核内包涵体有稳定的超微结构特征。在分生组织中，处于有丝分裂前期和中期的细胞中未找到包涵体。而在有丝分裂末期，观察到了纤丝状核内包涵体。本文认为这类包涵体起源     

急性镉中毒大鼠肝脏金属硫蛋白的免疫电镜定位

目的：研究急性镉中毒大鼠肝细胞中金属硫蛋白（ＭＴ）在超微结构水平的分布。方法： 羊抗兔ＩｇＧ－１０ｎｍ胶体金,结合自制的兔抗大鼠ＭＴ抗血清,在灌注固定的急性镉 中毒大鼠肝中,进行ＭＴ的包埋后免疫胶体金电镜定位观察。结果：镉暴露６ｈ大鼠肝细胞中有大量胶体金颗粒分布于胞质与细胞核内,而正常组肝细胞肿中胶体金颗粒数量很少。结论：急性镉中毒６ｈ的大鼠肝细胞中证实已有大量ＭＴ诱导产生,并旅游分布于胞质与细胞     

Properties of glucose-6-phosphate dehydrogenase of the liver tissue of intact rats and rats with Zaidel ascitic hepatoma

The properties of glucose-6-phosphate dehydrogenase (G6PDH; glucose-6-phosphate-NADP-oxidoreductase, EC 1.1.1.49) in the liver tissue of intact rats and those with ascites Zaidel hepatoma were compared. The specific activity of the enzyme from hepatoma was 7 times as high as that of the enzyme from the normal liver. The G6PDH preparations with the specific activity of 1.5 U/mg of protein were obtained by the three-stage purification. No differences in kinetic properties, coenzyme specificity and electrophoretic mobility of the enzymes from hepatoma and normal liver were observed.     

Dynamics of levels of 3-OAK antigens and ascorbic acid in the liver of rats and mice during hepatocarcinogenesis

Dynamics of the content of 3-OAK-A in the liver, blood and urine as well as of free and bound AK in the liver of rats and mice was traced by the quantitative precipitation reaction and oxidimetric method of ascorbic acid (AA) determination. It was shown that an increase in the content of 3-OAK-A in the liver during carcinogenesis initiation and progression is accompanied by a decrease in the AA content in this organ. One of the possible mechanisms inhibiting the formation of 3-OAK-A is "interception" of the proteins involved in the formation of 3-OAK-A.     

血卟啉单甲醚介导的光动力作用对小鼠肝癌细胞生长抑制的初步研究

目的：观察血卟啉单甲醚介导的光动力作用对小鼠肝癌H22细胞生长的抑制作用。方法：采用倒置显微镜观察和MTT法检测血卟啉单甲醚介导的光动力作用后小鼠肝癌H22细胞的生长情况。结果：血卟啉单甲醚介导的光动力作用显著抑制小鼠肝癌H22细胞的生长,在一定光能密度条件下,细胞生长抑制作用跟血卟啉单甲醚浓度间呈剂量依赖关系。倒置显微镜下观察到光动力作用组癌细胞数量显著减少,细胞固缩,而单纯光照组,单纯血卟啉单甲醚组和假照射组三组间无明显差异;MTT法示光动力组细胞抑制率显著高于单纯光照组、单纯血卟啉单甲醚组和假照射组（P〈0.05）,单纯血卟啉单甲醚组和假照射组间无明显差异（P〉0.05）。结论：血卟啉单甲醚光动力学作用对小鼠肝癌细胞H22生长抑制作用确切。     

Lack of sumatriptan-induced aortic contraction or relaxation: 5-HT1B receptor protein detected in endothelium and smooth muscle of vasa vasorum but not aorta

Since 5-HT1B receptor mRNA was reported in rat aorta, and 5-HT1B receptor activation has been linked to vascular contraction, we explored sumatriptan-induced contractility and immunohistochemical density of 5-HT1B receptor protein in rat aorta. Sumatriptan (up to 10(-4) M), a 5-HT1B/1D receptor agonist, did not contract the endothelial intact or denuded rat aorta, even in the presence of L-NAME or after induction of modest tone with PGF2 alpha (10(-6) M). Sumatriptan also did not relax aortic preparations precontract with PGF2 alpha (3 x 10(-6) M) or phenylephrine (3 x 10(-7) M). Using a polyclonal antibody directed against the 5-HT1B receptor, minimal 5-HT1B receptor protein was detected in either the endothelium or smooth muscle of the rat aorta. However, dense 5-HT1B receptor protein was found in the vascular smooth muscle of the vasa vasorum supplying the aorta. Thus, the 5-HT1B receptor mRNA detected in tissue extracts of the rat aorta most likely reflects 5-HT1B receptor expression in the arterioles of the vasa vasorum. These studies support the link between the 5-HT1B receptor and vascular contraction in that the aorta with low density of 5-HT1B receptors lacked responses to sumatriptan, an agonist thought to contract blood vessels via 5-HT1B/1D receptors. Furthermore, caution must be observed when using 5-HT1B receptor mRNA to suggest receptor protein in tissues since this RT-PCR product may be derived predominantly from small blood vessels.     

Noise in the detected output of small-area light-emitting diodes

The noise present in the detected optical output of three types of small-area electroluminescent diodes (GaAs diffused junctions (Al-Ga)As single and double heterostructures), operated continuously at high-current densities in a room-temperature ambient, has been measured in the frequency range of 300 Hz to 300 kHz. The best unit showed noise, with an1/f-type frequency dependence, which was less than twice the theoretical detector shot-noise limit at 350 Hz and that approached this shot-noise limit near 1.2 kHz.     

快速判断录像机故障部位的方法

录像机是记录声音和图像的磁记录设备,是一种高度精密而复杂的机电一体化家电设备。它不仅机芯结构精密,而且线路十分复杂,故对维修技术要求较高。不过,录像机出现故障时,大多数情况都反映到图像和伴音上,比如出现各类噪声、无图像、图像抖动、清晰度下降,只有黑白图像而无彩色或彩色失真等等。只要掌握录像机的工作原理,了解各部分电路或走带机构存在故障时对重放状态有何影响,最终表现在图像和伴音上是什么症状,就可以把图像和伴音出现的异常症状作为分析判断故障所在的依据,从而判断出故障存在的具体部位。影响重放图像质量的…     

Organ-specific antigens of the human intestines detectable in tumors

Rabbit antisera to an organospecific intestinal antigen are obtained. This antigen has beta 2-electromobility, is thermolabile, is not extracted by perchloric acid and phenol and immunologically differs from CEA. The antigen is found in bottom zone of colonic crypt and in carcinomas of colon and rectum.     

Possible role of Bac. megaterium H antigens common with tumor antigens in the increase of the antitumor activity of lymphocytes

The antitumour cytotoxic activity of lymphocytes is shown to increase both with inoculation of antigens contained in tumour cells and under the influence of microbial Bac. megaterium H., culture, its ultrasonic homogenate, cell walls and cytoplasmic preparation. Certain cytoplasmic fractions of Bac. megaterium H, like other microbial and tissue antigens having no similarity with tumour cells, did not produce such an effect. An assumption is advanced that the increase in the antitumour cytotoxicity of lymphocytes under the influence of Bac. megaterium H is due to the cross-reacting antigens contained in the microbial cell and blastoma tissue.     

On the electrically detected cyclotron resonance of holes in silicon nanostructures

The cyclotron resonance in semiconductor nanostructures is electrically detected for the first time without an external cavity, a source, and a detector of microwave radiation. An ultranarrow p-Si quantum well on an n-Si (100) surface confined by superconducting heavily boron-doped δ-shaped barriers is used as the object of investigation and provides microwave generation within the framework of the nonstationary Josephson effect. The cyclotron resonance is detected upon the presence of a microcavity, which is incorporated into the quantum-well plane, by measuring the longitudinal magnetoresistance under conditions of stabilization of the source-drain current. The cyclotron-resonance spectra and their angular dependences measured in a low magnetic field identify small values of the effective mass of light and heavy holes in various 2D subbands due to the presence of edge channels with a high mobility of carriers.     

Global optimization in the localization of neuromagnetic sources

The locations of active brain areas can be estimated from the magnetic field produced by the neural current sources. In many cases, the actual current distribution can be modeled with a set of stationary current dipoles with time-varying amplitudes. This work studies global optimization methods that find the minimum of the least-squares error function of the current dipole estimation problem. Three different global optimization methods were investigated: clustering method, simulated annealing, and genetic algorithms. In simulation studies, the genetic algorithm was the most effective method. The methods were also applied to analysis of actual measurement data     

无线传感器网络节点定位技术

无线传感器网络（Wireless Sensor Network,WSN）在许多领域有广泛的应用,无线传感器网络中节点位置对无线传感器网络的应用有重要的影响,没有位置属性的信息是无价值的,定位技术是无线传感器网络的重要研究方向之一.依据测距和非测距的分类方法,介绍节点定位技术的基本原理和方法及当前的发展状况,最后对节点定位技术的发展方向作展望.     

Immunocytochemical localization of glutathione precursors in plant cells

In plant cells, the antioxidant glutathione is synthesized out of its constituents cysteine, glutamate and glycine. As information about their subcellular and cellular distribution was not available in the past, the aim of the present study was to develop a technique that would allow visualization of their distribution in plant cells. With selective antibodies against cysteine, glutamate and glycine, it was possible, for the first time, to study the relative distribution of these components in meristematic root tip cells and mesophyll cells from older and younger leaves of Cucurbita pepo plants with the transmission electron microscope. These investigations revealed that high levels of cysteine accumulated in younger leaves. However, glutamate and glycine accumulated in the older ones, where cysteine levels were found to be significantly lower. On the subcellular level, glutamate was found in similar content in all investigated cellular compartments except for the cytosol, which showed up to 49% lower glutamate content (in younger leaves) than the other cell compartments. Levels of glycine were similar in all investigated cell compartments of one organ except vacuoles, which contained the lowest amounts of glycine. Cysteine was highest in plastids, the cytosol and in nuclei. When compared with younger leaves, glutamate and glycine were found to be accumulated in plastids (180 and 83%) and the cytosol (142 and 130%) of older leaves, whereas cysteine contents were found to be very low in the glutathione producing cell compartments of the leaves. These results indicate that low levels of cysteine might be a limitation for glutathione synthesis in older leaves. Cysteine and glycine were also detected in vacuoles where glutamate was absent. None of these components were detected in the apoplast. Therefore, these results indicate that glutathione degradation occurs within vacuoles or at the tonoplast, rather than at the plasmalemma or in the apoplast. Summing up, with the methods presented in this and a previous work, it is now possible to study the subcellular distribution of glutathione and its precursors in one plant sample simultaneously. The application of these methods on plant samples during abiotic and biotic stress situations should help us reveal possible limitations of glutathione synthesis during oxidative stress.     

无线传感器网络节点定位技术

无线传感器网络(Wireless Sensor Network,WSN)在许多领域有广泛的应用,无线传感器网络中节点位置对无线传感器网络的应用有重要的影响,没有位置属性的信息是无价值的,定位技术是无线传感器网络的重要研究方向之一。依据测距和非测距的分类方法,介绍节点定位技术的基本原理和方法及当前的发展状况,最后对节点定位技术的发展方向作展望。     

Induction of baboon herpes virus antigens in producing lymphoblastoid cells

Treatment of lymphoid 594S/F9 cells with 12-o-tetradecanoylphorbol-13-acetate (TPA), cycloheximide (CH) has no effect on cell proliferation. A reversible blocking of the cellular DNA and RNA synthesis is observed. Repeated treatment with TPA, iododeoxyuridine (IDU) or sodium butyrate (SB) causes more pronounced changes in cell metabolism, which sharply decreases the salt sensitive DNA polymerase activity. Simultaneously the activity of the virus-induced ammonium sulphate resistant DNA polymerase increases. The combined effect of TPA and CH stimulates the synthesis of viral antigens in certain latently infected cells. The number of productively infected cells remains approximately at the same level for 96 h. IDU has a highest effect on viral antigens expression at repeated induction.