A portal blood factor as the humoral agent in liver regeneration

It was demonstrated, by use of extracorporeal cross-circulation, that a humoral factor responsible for liver regeneration does not arise from the liver remnant. While intact livers of normal rats incorporated [methyl-(3)H]- thymidine in proportion to the amount of liver removed in the partner, the greatest response occurred after a total hepatectomy. Evidence from portacaval-shunted,partially hepatectomized animals connected to normal members indicates that the factor is in portal blood and that the onset of regeneration is the result of a quantitative imbalance between the available portal blood factor and the number of liver cells present.     

Protection through parabiosis against the lethal effects of exposure to large doses of x-rays

Parabiotic rat pairs with a skin-vascular anastomosis were used to test whether shielding of one member of the pair would protect the irradiated partner against exposure to very large doses of x-rays (1200 to 2400 roentgens). Except with the lowest dose, all unshielded, irradiated pairs or single irradiated animals died before 5 days had elapsed. In contrast, irradiated rats that had a shielded parabiont partner survived the 5-day period and many survived beyond 30 days. This is interpreted as protection against the acute intestinal death that normally occurs in the dose range investigated.     

矮败小麦利用的研究Ⅱ异交结实率

“矮败”小麦等的异交结实率和太谷核不育小麦一样，受多种因素影响，变动幅度较大，其中最关键的因素乃是矮秆的不育穗受到高秆不育株叶片的荫蔽。适当除去不育穗顶部遮挡的叶片，辅之以人工辅助授粉，可获得满意的效果。用鸡毛帚授粉，是授粉工具的最佳选择。     

Identification of the hepatocyte growth factor receptor as the c-met proto-oncogene product.

Hepatocyte growth factor (HGF) is a plasminogen-like protein thought to be a humoral mediator of liver regeneration. A 145-kilodalton tyrosyl phosphoprotein observed in rapid response to HGF treatment of intact target cells was identified by immunoblot analysis as the beta subunit of the c-met proto-oncogene product, a membrane-spanning tyrosine kinase. Covalent cross-linking of 125I-labeled ligand to cellular proteins of appropriate size that were recognized by antibodies to c-met directly established the c-met product as the cell-surface receptor for HGF.     

A parathyroid hormone-like protein from cultured human keratinocytes

Parathyroid hormone-like factors have been found in extracts of tumors associated with humoral hypercalcemia of malignancy, many of which are of squamous epithelial origin. Cultured, nonmalignant human keratinocytes were examined for the production of similar factors. Keratinocyte-conditioned medium from ten cultures stimulated the production of cyclic adenosine monophosphate in clonally derived rat osteosarcoma cells sensitive to parathyroid hormone. Bovine [Nle8,18, Tyr34]PTH-(3-34)NH2, a competitive inhibitor of parathyroid hormone, stopped the adenylate cyclase production stimulated by keratinocyte-conditioned medium, but antisera to parathyroid hormone had no effect on such adenylate cyclase activity. The active component of keratinocyte-conditioned medium has a molecular weight exceeding that of native parathyroid hormone. These characteristics are shared by the parathyroid hormone receptor agonists associated with humoral hypercalcemia of malignancy, which suggests that normal human keratinocytes may produce a factor related to that produced by malignant tumors associated with humoral hypercalcemia of malignancy.     

甲壳动物细胞及体液免疫机理的研究进展

根据国内外的有关资料,对甲壳动物细胞及全液免疫进行了简要的评述，其机体的免疫防御功能主要依赖于血细胞的吞噬，包掩等细胞免疫反应，但目前对于血细胞的分类及各自的功能尚无定论，甲壳动物体液吵具有免疫球蛋白，缺乏抗体介导的免疫反应，其体液免疫主要是指血淋巴中的一些酶和调节因子，如酚氧化酶原激活系统，落血素，凝集素，溶菌酶，蛋白酶抑制剂等。     

开孔农用隐蔽式通信电缆屏蔽效应分析(英文)

以农用隐蔽式信号电缆的开孔屏蔽壳体为研究对象,应用线性边界元法计算了屏蔽体上开有不同对称/非对称孔型时对屏蔽效能的影响。根据工程实例计算表明:对于双芯屏蔽电缆,当孔深较浅时屏蔽电缆的耦合电容影响不大,随着孔洞深度的增加,对称/非对称劈形孔耦合电容变化幅度最小;而不同形状孔洞的宽窄对耦合电容影响不太明显。     

Ferromagnetic contamination in the lungs and other organs of the human body

Contaminating particles which are ferromagnetic have been found in the human body. Their distribution was measured by applying an external magnetic field to the torso for a short time, and then, in a shielded room, mapping the steady magnetic field around the torso due to the magnetized particles. Maps of subjects show various distributions, including particles in the stomach from food cans and in the lungs from are welding. The fields from these two sources are strong enough to be detected with a flux-gate magnetometer, without the need for a shielded room. This simplicity of detection of larger amounts of ferromagnetic contamination suggests that this method may be used in two applications: in detecting the presence of large amounts of asbestos (ferromagnetic and harmful) in the lungs of asbestos workers, and in tests of the condition of the lung where FE(3)O(4) dust (ferromagnetic and harmless) would be used as an inhaled tracer material.     

Magnetoencephalography: detection of the brain's electrical activity with a superconducting magnetometer

Measurements of the brain's magnetic field, called magnetoencephalograms (MEG's), have been taken with a superconducting magnetometer in a heavily shielded room. This magnetometer has been adjusted to a much higher sensitivity than was previously attainable, and as a result MEG's can, for the first time, be taken directly, without noise averaging. MEG's are shown, simultaneously with the electroencephalogram (EEG), of the alpha rhythm of a normal subject and of the slow waves from an abnormal subject. The normal MEG shows the alpha rhythm, as does the EEG, when the subject's eyes are closed; however, this MEG also shows that higher detector sensitivity, by a factor of 3, would be necessary in order to clearly show the smaller brain events when the eyes are open. The abnormal MEG, including a measurenment of the direct-current component, suggests that the MEG may yield some information which is new and different from that provided by the EEG.     

Humoral immunosuppressive substance in mice bearing plasmacytomas

The mechanism by which plasmacytomas (PC) depress the primary immune response to sheep red cells was investigated by determining the ability of normal spleen cells to produce antibody when enclosed in Millipore chambers and implanted in PC-bearing mice. Chamber-enclosed normal spleen cells implanted in PC-bearing mice responded poorly to the sheep red cells when compared to similar cells enclosed in chambers and implanted in normal mice or in mice with other lymphoid and nonlymphoid tumors. The data suggest that PC-induced immune suppression is mediated by a humoral factor.     

短路故障下输电线路接地网对埋地管道的影响

为了研究输电线路故障运行时,接地点短路电流对管道的电磁干扰程度,利用防雷接地分析软件CDEGS建立了输电线路杆塔接地网与埋地管道模型,计算分析了不同短路电流幅值、土壤电阻率、管道间距下管道冲击电压的变化规律。提出了两种新型管道防护措施:①通过改变#形和方框射线形接地网形状参数,计算分析了管道冲击电压的变化规律,其表明接地网形状对接地电阻影响很大,接地电阻越大,管道冲击电压越小;②沿管道敷设非金属屏蔽线(柔性石墨复合接地材料),对管道进行过电压防护,可以有效降低管道冲击电压,对管道起到保护作用。研究结果可为油气管道设计施工及安全防护提供参考。     

Magnetic fields around the torso: production by electrical activity of the human heart

A search was made outside the torso for fluctuating magnetic fields produced by the heart. Detector and subject were housed in a highly shielded enclosure. Magnetic signals with amplitudes of 10(-8) to 10(-7) gauss were detected synchronously with the electrocardiogram, confirming previous reports. A magnetocardiographic chest map, consisting of the magnetic field plotted against time at various spatial positions, shows genteral QRS and T-wave structure, as in the electrocardiogram; this structure varies with spatial position.     

Forced unfolding of proteins within cells

To identify cytoskeletal proteins that change conformation or assembly within stressed cells, in situ labeling of sterically shielded cysteines with fluorophores was analyzed by fluorescence imaging, quantitative mass spectrometry, and sequential two-dye labeling. Within red blood cells, shotgun labeling showed that shielded cysteines in the two isoforms of the cytoskeletal protein spectrin were increasingly labeled as a function of shear stress and time, indicative of forced unfolding of specific domains. Within mesenchymal stem cells-as a prototypical adherent cell-nonmuscle myosin IIA and vimentin are just two of the cytoskeletal proteins identified that show differential labeling in tensed versus drug-relaxed cells. Cysteine labeling of proteins within live cells can thus be used to fluorescently map out sites of molecular-scale deformation, and the results also suggest means to colocalize signaling events such as phosphorylation with forced unfolding.     

Allograft survival: effect of antiserums to thymus glands and lymphocytes

Although antiserums to lymphocytes and thymus cells have similar effects on lymphocytes and thymocytes in vitro, the antiserum to thymus has more persistent lymphopenic effect in vivo and prolongs allograft survival time more markedly. Since only thymus glands of animals treated with antiserum to thymus showed depletion of small lymphocytes, antibody to thymic humoral factor may be operational.     

金黄色葡萄菌5型荚膜多糖偶联鞭毛蛋白疫苗对小鼠乳腺炎模型的保护作用

[目的]金黄色葡萄菌5型荚膜多糖(CP5)分别与鼠伤寒沙门氏菌鞭毛蛋白Flagellin、牛血清白蛋白(BSA)进行了偶联,并在小鼠模型上比较了这2种偶联疫苗所引起的体液免疫和粘膜免疫反应。[方法]以鼠伤寒沙门氏菌鞭毛蛋白为载体蛋白,与CP5进行化学偶联,并在小鼠乳腺部位免疫,然后通过检测小鼠乳汁中的抗体分析其对小鼠的免疫保护作用。[结果]乳腺局部免疫后flagellin-CP5组在乳腺部位引起了sIgA为代表的粘膜免疫反应和IgG为主的体液免疫反应。CP5和鞭毛蛋白的偶联物能够诱导更高的体液免疫以及粘膜免疫反应。[结论]鞭毛蛋白具有较强的免疫佐剂作用。     

鸡脾转移因子的制备及对雏鸡免疫应答的作用研究

采用透析法提取鸡脾转移因子(TF)并对其理化性质、生物活性、安全性进行了研究.通过对小白鼠腹腔注射低剂量、中剂量和高剂量转移因子(TF),和对10日龄未免疫健康雏鸡接种新城疫疫苗和不同剂量TF,观察TF对鸡红细胞的吞噬率和吞噬指数的影响以及TF的细胞免疫和体液免疫作用.结果表明:TF小鼠腹腔巨噬细胞吞噬鸡红细胞的最高比例和最高吞噬指数均产生在中剂量组,分别为60%和1.9,TF能增强T淋巴细胞转化率,与对照组相比新城疫抗体水平可提高3～4个滴度.     

Cardiac atria of BIO 14.6 hamsters are deficient in natriuretic factor

The hearts of 220-day-old hamsters of the BIO 14.6 strain are deficient in atrial natriuretic factor; saline extracts of atria produce one-third the natriuretic and diuretic effects of extracts of atria from age-matched normal hamsters. BIO 14.6 hamsters are known to develop congestive heart failure with edema when they are about 200 days old, and the venous congestion and edema are preventable by parabiosis with normal hamsters. The humoral mediator, the deficiency of which causes venous congestion and edema in BIO 14.6 hamsters, may be atrial natriuretic factor.     

Antigen competition: a paradox

Immunization of mice with pig erythrocytes caused impairment of the antibody response to subsequent immunization with sheep erythrocytes, a phenomenon called "antigen competition." Paradoxically, spleen cells from mice previously injected with pig erythrocytes produced an increased response when immunized in vitro with sheep erythrocytes. Augmentation of the in vitro response is due to an increase in one of the interacting cell types. "Antigen competition" is not due to competition for cells. Cell transfer experiments provided evidence that "antigen competition" observed in animals is the result of a humoral factor, presumably antibody, present in the animal but eliminated during preparation of cells for culture.     

A shared docking motif in TRF1 and TRF2 used for differential recruitment of telomeric proteins

Mammalian telomeres are protected by a six-protein complex: shelterin. Shelterin contains two closely related proteins (TRF1 and TRF2), which recruit various proteins to telomeres. We dissect the interactions of TRF1 and TRF2 with their shared binding partner (TIN2) and other shelterin accessory factors. TRF1 recognizes TIN2 using a conserved molecular surface in its TRF homology (TRFH) domain. However, this same surface does not act as a TIN2 binding site in TRF2, and TIN2 binding to TRF2 is mediated by a region outside the TRFH domain. Instead, the TRFH docking site of TRF2 binds a shelterin accessory factor (Apollo), which does not interact with the TRFH domain of TRF1. Conversely, the TRFH domain of TRF1, but not of TRF2, interacts with another shelterin-associated factor: PinX1.