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81.
V. Kumar 《Biotechnic & histochemistry》2004,79(5):197-201
Metal shadow casting techniques for transmission electron microscopic examination was used to determine the morphological characteristics of Mycobacterium leprae in untreated and treated patients. This technique is used to visualize bacterial surface structures by thermal evaporation of platinum alloys under moderate vacuum. This method gives a high contrast image at relatively low resolution and is useful for correlating micro-morphology quantitatively to early therapeutic effects of anti-leprosy drugs. Using these techniques in untreated cases, the surface structures of M. leprae were uniformly filled with relatively homogenous protoplasm surrounded by a cell wall. Most of the bacilli had thick cell walls with prominent banded and fibrous structures on the surface of the cell body. The cell wall was not detached in any of the solid bacilli in untreated cases. The bacilli varied in size and some of them were swollen in their mid-portion. Some bacilli were very short and completely filled with cytoplasm; therefore, these short bacilli were counted as solid bacilli in electron microscopic morphological index (EM-MI) determination. During treatment, mainly the cytoplasms of the bacilli were affected, and degeneration was observed. Ultrastructurally, the cytoplasm was shrunken and detached from the cell wall indicating mild degeneration. After moderate degeneration, the cytoplasm appeared fragmented. In advanced degeneration, all structures except the cell walls collapsed completely and no fibrous or band structures were visible on the surfaces of the cell walls. Therefore, these bacilli were counted as non-solid bacilli for EM-MI determination. This study shows that transmission electron shadowing gives more accurate counts than standard light microscopy of intact M. leprae bacilli in patient specimens. 相似文献
82.
Young-Chau Liu Chuen-Miin Leu Fen-Hwa Wong Wan-Shung Fong Shan-Chun Chen Chungming Chang Cheng-po Hu PhD 《Journal of biomedical science》2002,9(6):665-674
Insulin-like growth factor I (IGF-I) receptor (IGF-IR)-mediated signals are known to be involved in cell growth and transformation and prevention of apoptosis. In this study, we demonstrated the coexpression of IGF-I and IGF-IR in human esophageal carcinoma tissues. We also demonstrated the IGF-I autocrine system in esophageal carcinoma cell lines. Both the CE48T/VGH and CE81T/VGH cell lines showed proliferative responses to IGF-I stimulation. Autokinase activity of IGF-IR in these cells can be triggered by the exogenous addition of IGF-I. In addition, an IGF-I peptide antagonist, JB1, specifically inhibited ligand-induced receptor autophosphorylation in a dose-dependent manner. Under serum-free conditions, JB1 also reduced the degree of IGF-IR phosphorylation and cell numbers. Furthermore, the addition of JB1 decreased the number of CE81T/VGH colonies formed in methyl cellulose agar and the size and the incidence of tumors which grew in mice with severe combined immunodeficiency. These results imply that an IGF-I autocrine system in human esophageal carcinoma cells could stimulate tumor growth. Finally, we found that IGF-I prevented the apoptosis of CE81T/VGH cells induced by chemotherapeutic drugs, such as cisplatin, 5-fluorouracil and camptothecin. Thus, interruption of IGF-IR function may provide a way to retard tumor growth and increase the sensitivity of esophageal carcinoma to chemotherapy. 相似文献
83.
J. M. Romero M. I. Profeta N. L. Jorge M. E. Gómez-Vara A. H. Jubert 《Molecular simulation》2013,39(14-15):1075-1081
This paper deals with the synthesis of 3,6-dibutanoic-1,2,4,5-tetroxane and the theoretical study of its IR and UV spectra as well as the determination of its optimized molecular structure. Theoretical calculations are performed at the molecular dynamics (MD), molecular mechanics, semi empirical, ab initio and density functional theory (DFT) levels. The different structural and electronic effects determining the molecular stability of the conformers are discussed in a comparative fashion. 相似文献
84.
《Nucleosides, nucleotides & nucleic acids》2013,32(6-7):843-847
Expression of MDR1 and MRP genes in patients with low‐grade and high‐grade non‐Hodgkin's lymphomas with primary bone marrow involvement before and after chemotherapy was investigated. The data demonstrate that overexpression of MDR1 and MRP genes in hematological malignancies elevates in patients after chemotherapy and correlates with poor clinic prognosis and more frequent recurrences of the malignancies. 相似文献
85.
Viacheslav V. Senichkin Gelina S. Kopeina Eugeniia A. Prokhorova Alexey V. Zamaraev Inna N. Lavrik Boris Zhivotovsky 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(3):557-566
Background
The development of approaches that increase therapeutic effects of anti-cancer drugs is one of the most important tasks of oncology. Caloric restriction in vivo or serum deprivation (SD) in vitro has been shown to be an effective tool for sensitizing cancer cells to chemotherapeutic drugs. However, the detailed mechanisms underlying the enhancement of apoptosis in cancer cells by SD remain to be elucidated.Methods
Flow cytometry, caspase activity assay and western blotting were used for cell death rate evaluation. Western blotting, gel-filtration, siRNA approach and qRT-PCR were used to elucidate the mechanism underlying cell death potentiation upon SD.Results
We demonstrated that SD sensitizes cancer cells to treatment with chemotherapeutic agent cisplatin. This effect is independent on activation of caspases-2 and -8, apical caspases triggering apoptosis in response to genotoxic stress. SD potentiates cell death via downregulation of the anti-apoptotic protein Mcl-1. In fact, SD reduces the Mcl-1 mRNA level, which consequently decreases the Mcl-1 protein level and renders cells more susceptible to apoptosis induction via the formation of apoptosome.Conclusions
Mcl-1 protein is an important regulator of sensitivity of cancer cells to apoptotic stimuli upon SD.General significance
This study identifies Mcl-1 as a new target for the sensitization of human cancer cells to cell death by SD, which is of great significance for the development of efficient anti-cancer therapies. 相似文献86.
Sanja Mijatović Alessia Bramanti Ferdinando Nicoletti Paolo Fagone Goran N. Kaluđerović Danijela Maksimović-Ivanić 《Biotechnology advances》2018,36(6):1622-1632
Differentiation of cancer cells entails the reversion of phenotype from malignant to the original. The conversion to cell type characteristic for another tissue is named transdifferentiation. Differentiation/transdifferentiation of malignant cells in high grade tumor mass could serve as a nonaggressive approach that potentially limits tumor progression and augments chemosensitivity. While this therapeutic strategy is already being used for treatment of hematological cancers, its feasibility for solid malignancies is still debated. We will presently discuss the natural compounds that show these properties, with focus on anthraquinones from Aloe vera, Senna, Rheum sp. and hop derived prenylflavonoids. 相似文献
87.
目的:观察4种不同的化疗方案对侵蚀性葡萄胎的疗效并进行物经济学比较。方法:回顾性分析2014年01月至2017年01月我院收治的侵蚀性葡萄胎患者76例,分为甲氨蝶呤(MTX)组、EMA-CO组、新福菌素组(ACT)、5-氟尿嘧啶(5-Fu)+新福菌素组,观察4组患者治疗后的疗效、安全性,并采用成本-效果分析方法进行药物经济学分析。结果:4组患者在年龄、治疗花费、疗效间没有差异。MTX组药费最低(5876.5±644.9元,P0.01),成本-效果比最低(286.74元),但MTX组的化疗的副反应(骨髓抑制)发生率最高;其他三组同MTX组相比,其增量成本-效果比均2000元。联合化疗方案中,EMA-CO较5-Fu+ACT组药费较低(36027.2±1792.2元vs 60215.2±3632.8元,P0.01),增量成本效果优势明显(2542.69元vs 7963.19元)。结论:对于侵蚀性葡萄胎患者,针对患者的不同情况采用联合化疗或单药化疗,其疗效均无显著性差异。MTX组治疗花费最为经济,其他组增量成本-效果较高,考虑到副反应发生率、住院天数等其他因素,其他三组仍有选择优势。 相似文献
88.
目的:调查老年肺癌患者化疗期间抑郁情况及分析其相关因素。方法:选取2012年1月至2016年12月在我院化疗的老年肺癌患者300例,调查统计患者的基本信息资料,采用Zung氏自评抑郁量表(SDS)评价患者的抑郁情况,统计患者抑郁情况的调查结果,并采用Logistic回归分析影响老年肺癌患者抑郁的相关因素。结果:300例老年肺癌的患者当中,在化疗期间有抑郁者164例,占54.67%。其中59例是轻度抑郁,占35.98%;90例是中度抑郁,占54.88%;15例是重度抑郁,占9.15%。单因素分析显示,老年肺癌患者抑郁发生率与年龄、收入水平、TNM分期及有无癌症转移有关(均P0.05),与性别、文化程度、癌症分型无关(P0.05)。多因素Logistic回归分析显示影响老年肺癌患者抑郁的相关因素有年龄≥70岁、收入水平3000元/月、TNM分期为Ⅲ~Ⅳ期以及癌症转移(P0.05)。结论:老年肺癌患者在化疗期间较容易出现抑郁症状,临床上应加以重视,年龄≥70岁、收入水平3000元/月、TNM分期为Ⅲ~Ⅳ期以及癌症转移是影响老年肺癌患者抑郁的相关因素,针对相关因素应尽早采取相应的干预措施,从而有利于改善患者的负性心理情绪。 相似文献
89.
目的:讨论乳腺癌患者术后辅助化疗对患者激素水平及月经状况的影响。方法:收集我院2014年1月-2015年8月初诊绝经前乳腺癌患者78例,绝经后乳腺癌患者50例,检测化疗前及化疗结束后的雌二醇(E2)、黄体生成素(LH)、卵泡刺激素(FSH)水平,随访绝经前乳腺癌患者化疗期间及化疗后月经变化情况。结果:绝经前乳腺癌患者化疗后E2水平明显下降,FSH、LH水平明显升高,差异具有统计学意义(P0.05),绝经后乳腺癌患者化疗后E2水平无明显变化(P0.05),FSH、LH水平均下降,差异具有统计学意义(P0.05)。绝经前乳腺癌患者三个不同年龄段化疗后E2水平降低,而FSH、LH水平升高,差异具有统计学意义(P0.05),但三个不同年龄段患者化疗前后性激素水平组间比较均无统计学差异(P0.05)。绝经前乳腺癌患者三个不同年龄段化疗后闭经率比较差异具有统计学意义(P0.05)。绝经前乳腺癌患者化疗后闭经患者E2水平明显低于未闭经患者,FSH、LH水平明显高于未闭经患者,差异具有统计学意义(P0.05)。结论:化疗可影响乳腺癌患者E2、FSH、LH水平,导致患者闭经,闭经情况与患者年龄有关。 相似文献
90.
Optimal control of the chemotherapy of HIV 总被引:7,自引:0,他引:7
Using an existing ordinary differential equation model which describes the interaction of the immune system with the human
immunodeficiency virus (HIV), we introduce chemotherapy in an early treatment setting through a dynamic treatment and then
solve for an optimal chemotherapy strategy. The control represents the percentage of effect the chemotherapy has on the viral
production. Using an objective function based on a combination of maximizing benefit based on T cell counts and minimizing
the systemic cost of chemotherapy (based on high drug dose/strength), we solve for the optimal control in the optimality system
composed of four ordinary differential equations and four adjoint ordinary differential equations.
Received 5 July 1995; received in revised form 3 June 1996 相似文献