肉苁蓉种子的活力研究

目的为了改进TTC法测定肉苁蓉种子活力的方法和调查肉苁蓉种子于5℃贮藏时种子活力的变化。方法研究了TTC法中种皮、TTC溶液、次氯酸钠(NaClO)溶液和染色时间对肉苁蓉种子活力的影响,并用改进的方法测定了于5℃贮藏了不同年限种子活力。结果肉苁蓉种子于40℃下用0.5%TTC溶液染色48h后,再用0.2%NaClO溶液漂白2h后镜检;采收后贮藏于5℃保存1～2年的种子,其活力没有明显变化,但高活力种子的百分比随着贮藏年限的增加而增加。结论提供了一套方便快捷的测定肉苁蓉种子活力的方法;肉苁蓉种子于5℃贮藏有利于提高种子活力。     

茶多酚对人脐静脉内皮细胞增殖作用的研究

目的探讨茶多酚（TP）对人脐静脉内皮细胞（HUVEC）生长增殖的影响。方法采用二因素3×5析因设计及噻唑兰（MTT）比色法检测不同作用时间及剂量的仲对HUVEC的生长增殖作用，采用倒置相差显微镜观察HUVEC形态的变化。结果在24h时间段，120，160,240mg／L组，在48，72h时间段，80、120、160、240mg／L组与对照组吸光度有显著性差异。24，48，72h的半数抑制浓度分别是184．41，127．70，108．98mg／L。且TP作用时间与剂量之间有交互作用。结论TP能抑制HUVEC增殖且具有量效一时效依赖关系。     

MTT法测定乳腺癌对化疗药物敏感性的实验研究

目的探讨肿瘤药敏试验在乳腺癌化疗选药中的作用。方法将19例患者的浸润性乳腺导管癌组织进行体外培养,以临床常用的6种化疗药物加以干预,MTT法检测化疗药物对癌细胞的抑制率。结果浸润性乳腺导管癌细胞对顺铂、阿霉素、5-氟尿嘧啶、环磷酰胺、甲氨喋呤、多西紫杉醇中度敏感,6种化疗药物对乳腺癌细胞的抑制率无显著性差异(P=0.934)。结论初次化疗的浸润性乳腺导管癌患者对多种化疗药物均较为敏感。     

Matrix and serine protease expression during leukemic cell differentiation induced by aclacinomycin and all-trans-retinoic acid

In myeloid leukemia, immature leukemic cells are able to egress into peripheral blood to infiltrate extra-medullary organs. We therefore analyzed the migrating and invasive potential of human HL-60 and NB4 cell lines, representative of acute myelogenous leukemia, their ability to express matrix metalloproteases (MMPs), tissue inhibitors of metalloproteases (TIMPs) and urokinase plasminogen activator (uPA) in response to differentiating agents. Granulocytic differentiation by all-trans-retinoic acid (ATRA) and aclacinomycin (ACLA) strongly increased HL-60 and NB4 cell migration and invasion. At mRNA and protein levels, these cell lines produced significant amounts of MMP-9 (HL-60相似文献   

JM216-, JM118-, and cisplatin-induced cytotoxicity in relation to platinum-DNA adduct formation,glutathione levels and p53 status in human tumour cell lines with different sensitivities to cisplatin

The aim of this study is to establish anti-tumour potency of the new oral platinum drug JM216 and its metabolite JM118 in relation to the platinum (Pt)-DNA adduct formation, glutathione (GSH)-levels, and p53 status in human cancer cell lines with different sensitivities to cisplatin (CDDP). These parameters were studied in the CDDP sensitive human germ cell cancer cell line Tera and the small-cell lung cancer cell line GLC4 and their sublines with in vitro acquired CDDP resistance, Tera-CP and GLC4-CDDP, in a human ovarian cancer cell line transfected with mutant p53 (A2780/mt273) and with an empty vector as control (A2780/cmv), and in the intrinsic CDDP resistant human non-small-cell lung cancer cell line SW1573/S1 and colon carcinoma cell line Caco-2. Cytotoxicity was tested with the microculture tetrazolium (MTT)-assay. Pt-DNA adduct levels were assessed immunocytochemically. Quantitative analysis was performed by double fluorescence video microscopy. Results were correlated with GSH levels and p53 status of the cell lines. This study showed that both JM216 and JM118 can partially circumvent intrinsic and acquired resistance to CDDP. Drug-induced cytotoxicity only correlated negatively with GSH levels for JM216 and CDDP in the tested unselected cell lines. At equimolar basis, JM216 induced lower levels of Pt-DNA adducts in the various cell lines than JM118 and CDDP, whereas the JM118-induced amount and pattern of Pt-DNA adducts was comparable to CDDP. No difference in initial Pt-DNA adducts levels was observed between cell lines sensitive, acquired or intrinsic resistant to CDDP suggesting a Pt-resistance mechanism based on tolerance or increased repair, rather than decreased initial Pt-DNA adduct formation.     

Exchange transfusion in neutropenic septicemic neonates: effect on granulocyte functions

Depletion neutropenia caused by overwhelming bacterial infection is associated with fatal outcome and is an objective indicator of the severity of sepsis. Studies on controlled evaluation of exchange transfusion in the management of severe neonatal sepsis have not considered neutropenia as an inclusion critcrion, and randomized, controlled trials on evaluation of ncutrophil functions after exchange transfusion are scarce. This prompted us to carry out the present study. Septicemic neonates were enrolled if they had neutropenia and were randomized to undergo exchange transfusion (study group, n = 20) or not (controls, n= 10). Granulocyte functions were assessed using the nitro blue tetrazolium (NBT) reduction test and the staphylococcicidal index. Blood was drawn for granulocyte function tests once from controls and donors, and before, immediately after and 6 h after exchange transfusion in the study group. Mortality was 35% in the study group and 70% in controls. Gram-negative organisms accounted for 80%, in the study group and 90% in controls. Mean total leukocyte count and neutrophil count increased significantly immediately after exchange transfusion and 6 h later. Absolute band count decreased significantly immediately after exchange transfusion and incrcased 6 h later. NBT reduction in septicemic neonates in the study group, as wclras in controls. was significantly decreascd as compared to donor cells. NBT reduction improved significantly immediately after exchange transfusion and 6 h later. The valucs of the perccntage of viable staphylococci recovered from neutrophils also improved significantly immediately after exchange transfusion and 6 h later. We conclude that exchange transfusion with fresh whole blood in severe neonatal septicemia with neutropenia improves survival, increases the neutrophil count and cnhances neutrophil function.     

Glucose-6-Phosphate Dehydrogenase (G-6-PD) Hamburg, a New Variant with Chronic Nonspherocytic Haemolytic Anaemia

Abstract. A new variant of G-6-PD with chronic nonspherocytic haemolytic anaemia and very low activity, named G-6-PD Hamburg, was partially purified and biochemically characterized. It was found to have very high lability, an unusually high Km for G-6-P (2000 μM), increased utilization rates for 2-desoxy G-6-P (133%) and galactose-6-phosphate (87%) and an abnormal pH-activity curve. The electrophoretic mobility seemed to be normal. The leukocytes also revealed diminished G-6-PD activity. No impairment of bactericidal activity of neutrophilic granulocytes, as shown by a normal nitroblue tetrazolium reduction, could be demonstrated.     

Reactivity of alveolar macrophages during granulomatous inflammation of the lungs under conditions of acute massive blood loss

Reactivity of mouse alveolar macrophages by their ability to phagocytize killedSt. aureus bacteria and production of reactive oxygen metabolites (nitro blue tetrazolium test) in response to zymosan administration was studied under normal conditions and after acute massive blood loss. Zymosan-induced granulomatous inflammation of the lungs during acute massive blood loss 2-fold inhibited the increase in oxidative metabolism of alveolar macrophages. Suppressed production of toxic oxygen radicals in alveolar macrophages was accompanied by accelerated recovery of cells on the surface of the respiratory tract. Translated fromByulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 138, No. 9, pp. 257–260, September, 2004     

A new structural class of proteasome inhibitors identified by microbial screening using yeast-based assay

A yeast-based growth interference assay was developed utilizing a yeast strain in which expression of Xenopus cyclin A1 was induced to elevate cell division cycle 28 (Cdc28) kinase activity. Since the hyperactivation of Cdc28 kinase in yeast results in a growth-arrest phenotype, compounds which could rescue the cyclin A1-induced growth arrest might be potential new, antitumor drug candidates acting on the cyclin-dependent, kinase-mediated, cell cycle regulation pathway. In the course of our microbial screening program, the new Streptomyces metabolites, belactosins, were identified. As reported previously, belactosin A induced cell cycle arrest at G2/M phase in human cancer cells. However, the molecular mechanism of action was unknown. We herein demonstrate the proteasome inhibition by belactosin A. Belactosin A did not inhibit yeast Cdc28 kinase and human cyclin-dependent kinase in vitro. On the other hand, it inhibited the chymotrypsin-like activity of the rabbit 20S proteasome. From the initial SAR studies, we identified a hydrophobic belactosin A derivative, KF33955, which exhibited a 100-fold greater growth-inhibitory activity against HeLa S3 cells than belactosin A, presumably due to its higher cell permeability. The biochemical analysis using KF33955 suggested that the proteasome inhibitory activity of KF33955 were irreversible and required the beta-lactone moiety to inhibit the proteasome. KF33955 increased the intracellular levels of protein ubiquitination in NIH3T3 cells. In addition, KF33955 treatment resulted in the accumulation of known proteasome substrates in HeLa S3 cells. These results identify belactosin A as a useful lead compound to target proteasome for the treatment of disease whose etiology is dependent on the unregulated ubiquitin-proteasome pathway.