小包装全氟丙烷气体动力学实验研究

为检验塑料小包装全氟丙烷气体（C3F8）在不同包装和储存方法时浓度变化，将装有5～7mlC3F8的聚氯乙烯小袋，根据不同储藏温度和外包装方法随机分成四组：（1）22℃聚乙烯外包装，（2）36℃聚乙烯外包装，（3）22℃铝箔真空外包装，（4）-29℃聚乙烯外包装；每一组C3F8小袋气体存放一定时间后，应用气相色谱分析方法进行浓度测量。结果：第3组C3F8浓度最高和稳定，第2组浓度随放置时间降低最明显，第4组是临床应用气体的储藏和包装方法，其30天样本浓度和第3组相等，但放置一年时浓度降低。结果显示：塑料小包装C3F8予以铝箔真空外包装是一种可行的方法，利于C3F8运输和普及；聚乙烯外包装的C3F8，应放在-29℃保存，时间不超过一年。     

Association of a 70-kDa tyrosine phosphoprotein with the CD16:ζ:γ complex expressed in human natural killer cells

The CD16: ζ: γ receptor complex allows natural killer (NK) cells to recognize and eliminate antibody-coated target cells. Whereas the ectodomain of CD16 is the receptor for Fcγ domains of immunoglobulins, disulfide-linked homo- and heterodimers composed of ζ and γ are required for the cell surface expression, and signal transduction properties of the complex. Engagement of CD16 activates the tyrosine kinase pathway, which induces the tyrosine phosphorylation of several substrates, including the ζ subunit and the phospholipase C γ-1 and γ-2 isoforms. Here we show that CD 16 stimulation of either peripheral blood NK cells, leukemic NK cells, or Jurkat transformants expressing a CD16:ζ:γ receptor complex, results in the tyrosine phosphorylation of a 70 kDa ζ-associated protein (pp70). Similarly, a 70-kDa ζ-associated phosphoprotein in T cells has been shown to be a tyrosine kinase (ZAP-70). Peptide mapping analysis indicates that the 70-kDa ζ-associated phosphoproteins from T cells and NK cells are structurally indistinguishable. We conclude that the CD16:ζ:γ complex may use a ZAP-70-related non-receptor tyrosine kinase, in the CD16 signaling cascade leading to NK cell activation.     

Lindane inhibition of [35S]TBPS binding to the GABAA receptor in rat brain.

The inhibition of [³⁵S]t-butylbicyclophosphorothionate ([³⁵S]TBPS) binding to the GABA_A receptor by the insecticide γ-hexachlorocyclohexane, lindane, was studied in several brain regions and using different membrane preparation methods, both in vitro and after dosing the animals with the chemical. In the latter studies, the amount of lindane remaining in the membrane suspensions used for binding assays was determined. In vitro data showed values of IC₅₀ from 150 to 1675 nM, varying in function of the membrane preparation method used. This may account for the discrepancies in IC₅₀ values found in the literature. IC₅₀ values within the range of 150–250 nM were determined using extensively washed membranes from several brain regions, so no evidence arose for brain regional differences in the affinity of lindane for the TBPS binding site. After different schedules of acute treatment with lindane, we found a manifest relationship between the extent of the observable inhibition of [³⁵S]TBPS binding and the lindane amount remaining in the membrane suspensions used for binding assays. This relationship was in good agreement with the in vitro data, so no support for an in vivo acute regulation of the binding site was obtained.     

Stability studies of the components of a prototype penicillinase (β-lactamase)-linked ELISA kit

Penicillinase (β-lactamase) enzyme-linked immunosorbent assay (ELISA) for various reproductive hormones developed in the laboratory were found to have wide applicability in the fertility check clinic of the Institute. A need was thought to transform these assays into ready-to-use kit forms. Therefore, prototype ELISA kits for these hormones were developed and stability of the individual component was ascertained at various temperatures (room temperature, 37°C and 2-8°C). Stability studies were conducted on previously validated assay for pregnanediol-3α-glucuronide (PdG). The studies showed that immunosorbents (antibody coated plates) are stable at room temperature for a period of 2 weeks, at 37°C for 1 week and at 2-8°C for a period of 9 months when preserved after treatment with glycerol solution. The lyophilised conjugate, standard and immunoassay buffer, colour reagent, and its substrate were stable at 37°C up to 1 week and at room temperature up to 2 weeks and at 2-8°C for a period of 6 months, during which the stability was studied. © 1993 Wiley-Liss, Inc.     

薄层扫描法测定复脉定冲剂中远志有效成分的含量

采用薄层扫描法对复脉定冲剂中远志有效成分３，４，５－三甲氧基反式肉桂酸乙酯的含量进行测定。方法简单、快速，结果可靠，可作为该制剂的质控标准。     

Effect of 1α-hydroxyvitamin D3 on bone metabolic disorders in gastrectomized rats

The effect of 1α-hydroxyvitamin D₃ (1α(OH)D₃) on the metabolic bone disorders developed in gastrectomized rats were investigated biochemically and histomorphologically. 1α(OH)D₃ was suspended in 0.2 % Triton-X-100 aqueous solution after dissolving in a very small amount of ethanol, was given orally to the rats for 10 weeks. The sham operated animals and the gastrectomy control animals received the vehicle alone. Gastrectomy was followed by the development of the metabolic bone disorders after 10 weeks of observation. This was characterized by reduction in ash content of the femur and histologically by a disappearance of the trabecular bone in tibial metaphysis. Decrease Ca absorption from the intestines was demonstrated by a radiotracer technique. Biochemical studies showed significant decreases in serum 25(OH)D concentration in gastrectomized rats. These findings suggest that gastrectomy partially impairs intestinal absorption of calcium and results in a negative calcium balance, which may contribute to the development of bone metabolic disorders in rats. The administration of 1α(OH)D₃ increased dose-dependently serum calcium and Ca absorption from the intestine and prevented the development of bone metabolic disorders histomorphologically.     

Hereditary Hypertriglyceridemic Rat: A New Animal Model of Metabolic Alterations in Hypertension

Hereditary hypertriglyceridemic rats (hHTg) were developed as a new genetic model for the study of relationships between blood pressure (BP) and metabolic abnormalities. This strain has been produced by selective inbreeding from Wistar rats according to the rise of plasma triglycerides induced by a high-sucrose diet. Though hHTg rats display hypertriglyceridemia, impaired glucose tolerrance, hyperinsulinemia, insulin resistance and increased BP even without nutritional stimuli, high sucrose feeding further aggravates these symptoms. High plasma triglycerides levels in hHTg rats seem to be a consequence of their hyperproduction. Impaired insulin action is responsible for the defective glucoregulation in this strain. The loss of insulin responsiveness might be due to a reduction in the number of glucose transporters. Highly significant relationships among plasma triglycerides, ouabain-resistant Na⁺ transport and BP were demonstrated in the hHTg rats. Segregating populations (F2 hybrids) should be used for genetic analysis of the primary role of lipid and/or ion transport abnormalities in the pathogenesis of this form of genetic hypertension.     

The mitogenic effect of KGF and the expression of its cell surface receptor on cultured normal and malignant human oral keratinocytes and on contiguous fibroblasts

This study examined the mitogenic response to keratinocyte growth factor (KGF) of normal and tumour-derived human oral keratinocytes in which the degree of cellular differentiation was known and in contiguous fibroblast cultures derived from the malignant epithelial cultures. Keratinocytes, but not fibroblasts, were stimulated by KGF. There by demonstrating epithelial target cell specificity of the ligand. KGF-induced stimulation of the tumour-derived keratinocytes cultured in the absence of the 3T3 fibroblast support broadly correlated with the degree of cellular differentiation; well-differentiated keratinocytes were stimulated more by KGF than their less differentiated counterparts. Malignant oral keratinocytes expressed KGF cell surface receptors (K_D 451-709 pM; receptors/cell 2306-413645), but KGF receptor mRNA did not correlate with either KGF-induced mitogenesis or the degree of epithelial cell differentiation. When the tumour-derived keratinocytes were cultured in the presence of 3T3 fibroblasts, the mitogenic response to KGF was comparable to normal epithelial cells. The results suggest that KGF-mediated growth stimulation may not be significant in providing a selective advantage for the growth of malignant keratinocytes.     

Immunological Detection and Quantitation of DNA Adducts Formed by 4-Aminoazobenzene Species in vivo

Antibodies to 3-methoxy-4-aminoazobenzene (3-MeO-AAB) and 2-methoxy-4-aminoazobenzene (2-MeO-AAB) DNA adducts were raised in rabbits against in vitro-adducted DNA samples. The enzyme-linked immunosorbent assay (ELISA) was used to determine the sensitivity and specificity of these antibodies. They proved highly specific for the modified DNA used as the immunogen, but cross-reacted with each other. Moreover, they showed cross reactivity with DNA modified by 4-( o -tolylazo)- o -toluidine, but not by other carcinogens, such as 4-aminobiphenyl or 4-nitroquinoline 1-oxide. The 50% inhibition level of antibody binding in the competitive ELISA was at 10–20 fmol of modified base per assay (equivalent to 1–2 adducts per 10⁶ bases). Immunohistochemical staining indicated that these antibodies bind specifically to nuclear components of the liver in rats given either 3-MeO-AAB or 2-MeO-AAB at the dose of 50 mg/kg body weight.     

Multiple sclerosis: myelin basic protein induced mRNA expression of proinflammatory cytokines in mononuclear cells is suppressed by interferon-β 1b in vitro

Beta-interferon (IFN-β) is a promising treatment in multiple sclerosis (MS), reducing the exacerbation rate and MRI lesion burden, as well as the disease progression in relapsing-remitting MS. IFN-β was originally defined by its antiviral effects, but the interest has recently been focused on its immunomodulatory properties. Myelin basic protein (MBP) is one of several autoantigens considered to be the target for autoaggressive immune responses, which eventually might lead to the development of MS. To study in-vitro effects of IFN-β1b on MBP induced cytokine expression, mRNA for the Th1 cytokines IFN-γ and TNF-α, the Th2 related IL-4 and IL-6, the cytolytic perforin and the immune response downregulating TGF-β was measured with in situ hybridization after culture of blood mononuclear cells (MNC) in the presence and absence of MBP. Numbers of cells expressing IFN-γ, TNF-α, perforin and IL-4 mRNA were significantly suppressed after culture with 10 U/ml IFN-β1b. No such effect was seen on MBP induced IL-6 or TGF-β mRNA expression. These observations suggest that one of the major effects of IFN-β1b is the induction of a shift in the cytokine mRNA profile towards a more immunosuppressive pattern. In parallel in vitro tests, the control substance dexametasone (40 μg/ml) reduced the numbers of cells expressing mRNA for all cytokines under study with the exception of TGF-β, to an extent equal to or even more pronounced than IFN-β1b.