In vitro reversal MDR of human carcinoma cell line by an antisense oligodeoxynucleotide-doxorubicin conjugate.

A conjugate of antisense oligodeoxynucleotide (AS ODN) covalently linked with deoxorubicin (DOX) was synthesized. Its properties and antitumour activity in human carcinoma DOX resistant cells (KB-A-1) were investigated in vitro. The results showed that the conjugate was strongly stable both in Dulbecco's Phosphate-Buffered Saline (PBS) and in culture medium. The intracellular concentration of the conjugate was higher than that of the AS DON by HPLC analysis. The conjugate showed potent dose-dependent inhibition to the growth of KB-A-1 cells. Chemosensitivity of KB-A-1 cells to DOX was also investigated in vitro. When the cells were first exposed to the conjugate (0.5 microM) and then exposed to DOX for 24 h, the IC50 value of DOX decreased from 21.5 to 2.2 microM. In contrast, when treated with the mixture of the same concentration of the AS ODN with equivalent DOX, the IC50 value of DOX was 16.8 microM. Intracellular DOX concentration was detected in KB-A-1 treatment with the conjugate in vitro by HPLC. The results showed that the intracellular DOX concentration was 6.4-fold increased in KB-A-1 cells treated with the conjugate compared to treatment with DOX alone. In contrast, 1.8-fold increasing was observed when treated with the AS ODN. Western blot analysis showed a significantly decrease in the amount of P-glycoprotein in KB-A-1 cells. These results suggest that the conjugate is effective in reversing multidrug resistance. Certainly, further studies are conducting to explore the antitumour effect of the conjugate in vivo.     

Use of the Arndt wire-guided endobronchial blocker via nasal for one-lung ventilation in patient with anticipated restricted mouth opening for esophagectomy.

Functional separation of the lungs may be accomplished by several methods. Patient with restricted mouth opening has limited options for one-lung ventilation. We report the use of wire-guided endobronchial blockade, a new tool for achieving one-lung ventilation in a patient with restricted mouth opening requiring nasotracheal, fiberoptic intubation for esophagectomy and reconstruction with gastric tube substitution.     

Study on hemostatic mechanism of fully soluble hemostatic fiber.

Fully soluble hemostatic fiber (FHF) is made from cotton yarn through a series of chemical reactions with NaOH and chloroacetic acid. The major component of FHF is carboxymethylcellulose. FHF is a kind of biodegradation macromolecule material that can disassociate into a low-molecular-weight compound or a simple substance by hydrolytic and enzymatic courses. The purpose of the present study is to investigate the hemostatic mechanism of FHF. The study indicated that FHF can stop bleeding by physical, chemical and physiological routes. In the physical route, expansion of carboxymethylcellulose in FHF stops bleeding by forming a mechanical clog after contacting with the blood. In the chemical route, the platelets can quickly aggregate around FHF and stimulate releasing and disaggregating reactions, after contacting with the rough surface of FHF, producing thrombus and hemostasis. In the physiological route, gluey particles with negative charges can activate intrinsic coagulation systems by activating the blood coagulation factor XII after FHF dissolution.     

Production and characterization of high affinity monoclonal antibodies to cyclic anti-depressant molecules

A procedure is reported by which high levels of the tricyclic molecule desipramine was modified and conjugated at high density to the carrier molecules keyhole limpet hemocyanin and bovine serum albumin so that these could be used as immunogens in Balb/c mice. Such conjugates generated immune responses with high levels of antibody with specificity for the tricyclic. B cell hybridomas generated by fusion of immune Balb/c splenocytes to NS-1 cells which secreted monoclonal antibodies with specificity for the tricyclic were selected in a standard ELISA. In this report, we show that the binding constants of these monoclonal antibodies with various haptens can be assessed accurately by measuring fluorescence polarization, that a high degree of cross-reactivity between the monoclonals and various tricyclics exists, and that this procedure can be used to generate monoclonal antibodies of high binding constants.     

~(125)Ⅰ眼镜蛇毒及抗眼镜蛇毒血清在小白鼠体内分布的比较观察

用氯胺-T法125I标记眼镜蛇毒示踪液及抗眼镜蛇毒血清。小白鼠分二组，用125I-眼镜蛇毒、125I-抗眼镜蛇毒血清分别给小白鼠尾静脉注射，于注射后的不同时间测定血、颈部肌肉、肝、肺、肾、心等脏器放射性分布。结果发现：125I-眼镜蛇毒在肌肉及肝、肺等器官中于注射后2小时过高峰，在肾脏中浓度高，在脑未见放射性分布，抗眼镜蛇毒血清与眼镜蛇毒分布相似但在肌肉及肺脏有更高的分布。证明抗眼镜蛇毒血清能跟踪分布眼镜蛇毒。     

螺旋神经节神经元原代培养及其免疫细胞化学鉴定

目的 建立成体哺乳动物耳蜗螺旋神经节神经元（ＳＧＮ）体外培养的细胞模型。方法 对出生后７ｄ的Ｗｉｓｔａｒ大鼠的螺旋神经节细胞进行解离与分散培养。用荧光显微镜与倒置相差显微镜观察原代培养ＳＧＮ细胞的活力以及生长与分化过程。应用链霉卵白素过氧化物酶（ＳＰ）方法和抗神经丝蛋白单克隆抗体（ＮＦＰ－ＭｃＡｂ）对ＳＧＮ进行免疫细胞化学染色鉴定。结果 幼龄Ｗｉｓｔａｒ大鼠的ＳＧＮ在体外条件下，可良好存活并有正常     

神经肽Y对免疫细胞活性的影响

神经肽Y（NPY）是广泛分布于中枢神经系统和外周神经各部位的神经肽类物质。本实验观察NPY在体外对几种免疫细胞活性的直接作用。结果表明，NPY对小鼠T淋巴细胞丝裂原反应性和NK细胞的杀伤活性均无明显影响（P＞0．05），对巨噬细胞分泌溶菌酶有明显抑制作用（P＜0．05）；而对B淋巴细胞丝裂原反应性则有明显的促进作用（P＜0．05）。上述结果提示，NPY对部分免疫细胞功能的影响因细胞种类而异。     

Infectivity of African cassava mosaic virus clones to cassava by biolistic inoculation

Summary.  Clones of an African cassava mosaic virus isolate originating from Nigeria (ACMV-NOg) were shown to be infectious to cassava by biolistic inoculation. The production of pseudorecombinants between ACMV-NOg and clones of an ACMV isolate originating from Kenya (ACMV-K) indicated that the lack of infectivity of ACMV-K to cassava was due to defect(s) in the DNA B genomic component; this component encodes two proteins involved in cell-to-cell movement. This is the first demonstration of infectivity of a cloned geminivirus to cassava and conclusively proves that ACMV is the causative agent of cassava mosaic disease. The potential uses of infectious ACMV clones and the means by which to introduce them into cassava are discussed. Received January 18, 1998 Accepted May 27, 1998