The multidrug resistance phenotype: 31P nuclear magnetic resonance characterization and 2-deoxyglucose toxicity

In order to identify changes in 31P nuclear magnetic resonance (NMR) spectra associated with multiple drug resistance (MDR), a number of wild type and drug-resistant cancer cell lines were studied. The resistant cells included cells selected with various drugs, mainly Adriamycin, as well as cells transfected with the human multidrug resistance gene (MDR1 gene), which encodes P-glycoprotein. In most cases, 31P NMR spectra were significantly different from those of parental, drug-sensitive lines. The spectra of resistant cells generally indicated increased levels of ATP and phosphocreatine in the cytoplasm. These changes are compatible with the increased glucose utilization rate previously described for resistant cells. Major changes were also observed in the levels of glycerophosphocholine and glycerophosphoethanolamine. Changes in cellular metabolism reflected by 31P NMR spectra depend on the drug used to select the cells for MDR. The direction of these changes was not consistent for all cell lines studied and could not be directly attributed to expression of P-glycoprotein, suggesting that the changes may be related to alterations in metabolism and membrane function associated with other mechanisms of MDR. The results demonstrate the suitability of 31P NMR for studies of biochemical changes associated with MDR. The toxicity of 2-deoxyglucose, a glucose antimetabolite, was investigated in addition to the NMR studies and was found to be consistently higher in multidrug-resistant cells than in the parental drug-sensitive lines. For MCF-7 breast cancer cells, where several sublines with different levels of resistance were available, the toxicity was highest for the most resistant lines.     

Delayed hepatic CT scanning: increased confidence and improved detection of hepatic metastases

Fifty oncologic patients with suspected hepatic metastases were prospectively evaluated by dynamic sequential hepatic computed tomography (DSHCT) and by delayed iodine hepatic computed tomography (DICT) scanning. DICT scanning was performed 4-6 hours following administration of 60 g of intravenous iodine. Both techniques were evaluated for lesion definition relative to the adjacent hepatic parenchyma and for numbers of metastases detected. Metastases were detected by both techniques in 26 patients. Fifteen patients (58%) had lesions better defined by DICT. DICT scanning detected more metastases in seven of these 15 patients. In eight patients (31%), there was no difference between the two techniques in numbers of masses detected or lesion definition. In three cases (11%), metastases were more confidently identified on the initial or DSHCT scan. DICT scanning, as described, is useful in defining and detecting hepatic metastases, especially where there is questionable hepatic involvement or better quantification of size is necessary.     

End-tidal carbon dioxide concentration,carbon dioxide production,heart rate,and blood pressure as indicators of induced hyperthermia

In 4 spontaneously breathing, barbiturate-anesthetized dogs, hyperthermia was induced with 2,4-dinitrophenol while rectal temperature, heart rate, mean blood pressure, end-tidal carbon dioxide, and carbon dioxide production (milliliters per minute) were measured continuously. The latter was determined with a pneumotachygraph (to obtain respired volume) and an infrared carbon dioxide analyzer that measured inspired and expired carbon dioxide concentration. Of the five physiologic measurements, the increase in carbon dioxide production preceded the increase in rectal temperature by more than 120 seconds. End-tidal carbon dioxide was an unreliable indicator in the spontaneously breathing animal of approaching hyperthermia during spontaneous breathing due to a transient tachypnea, which decreased end-tidal carbon dioxide. The carbon dioxide production (milliliters per minute) increased immediately and reached three to five times the control value. Blood pressure and heart rate were insensitive indicators of approaching hyperthermia.     

Recent patterns in chronic disease mortality in remote living Indigenous Australians

Background  

Despite the well-recognised Indigenous-non-Indigenous health disparity, some reports suggest improvements in Indigenous mortality. Our aim was to quantify Indigenous mortality in Outer Regional (OR), Remote (R), and Very Remote (VR) areas in New South Wales, Queensland, South Australia, Western Australia, and the Northern Territory and changes in mortality from 1998 to 2005.     

国家级首批线上一流课程免疫学基础与病原生物学的建设与推广

线上一流课程作为一种新型的教学课堂模式,其建设与推广不仅使教师的教和学生的学呈现多元化,而且也使教师的教学和研究水平、学生的学习兴趣和能力得到了有效提升。本团队建设与推广的国家级首批线上一流课程免疫学基础与病原生物学已经完成6个学期的运行,累计学习人数40 395人,累计选课学校84所。本文从建设背景与建设目标、整体框架与建设资源、实施过程与推广应用、教学运行与互动、教学考核与评价、思考和展望等6个方面总结该课程的建设与推广情况。     

Direct identification of Yersinia enterocolitica in blood by polymerase chain reaction amplification

Primers based on the nucleotide sequence of the virF gene in the pYV plasmid and the chromosomal ail gene were used in polymerase chain reaction (PCR) amplifications to directly identify Yersinia enterocolitica in blood. Approximately 500 bacteria seeded into 100 microL of blood can be extracted and amplified by PCR to yield positive results. PCR analyses of seven Y. enterocolitica isolates previously implicated in blood contaminations showed that only one isolate harbored the plasmid-borne virF gene; however, all seven isolates were identified effectively by the PCR product amplified from the chromosomal gene. The PCR assay has the potential for use in the identification of Y. enterocolitica contamination in stored units of blood or in the rapid diagnosis of transfusion-related bacteremia caused by Y.     

2,3-吲哚醌在大鼠体内的药代动力学研究

目的考察单次静脉注射和口服给予大鼠2,3-吲哚醌后的药代动力学,为该药的新药开发提供依据。方法大鼠给药后经眼眶静脉采大约0.25 ml血液,采集时间点为：给予受试物前（0hr）和给予受试物后5 min,15min,30 min,1 h,2 h,4 h,6 h,8 h和24 h。血液样本采集后置于冰上,并立即取出50μl全血采用甲醇蛋白沉淀进行预处理,奎硫平作为内标。预处理后样品采用LC/MS/MS法进行测定,并用药动学处理软件WinNonlin 5.2采用非房室模型计算相关药代动力学参数。结果 Sprague Dawley大鼠静脉注射和口服两种制剂的药动学参数（平均值±标准偏差）如下。静脉注射：Tmax为0.83±0.29 hr,Cmax为141.53±10.99μg/L,T1/2为1.68±0.84 hr,AUC0-t为1068.15±389.06μg.hr/L,AUC0-∞为1211.19±469.18μg.hr/L,Vz为4.13±1.41 L/kg,CLz为1.89±0.94 L/hr/kg;口服：Tmax为0.05±0.00 hr,Cmax为1725.53±469.70 ng/ml,t 1/2为4.21±2.78 hr,AUC0-t为7711.21±2533.12μg.hr/L,AUC0-∞为7986.07±2623.38μg.hr/L,以AUC0-t计算,生物利用度平均为57.75±18.97%。结论 2,3-吲哚醌大鼠体内消除较快,可能存在非线性消除,口服吸收较好。     

A role for macroautophagy in protection against 4-hydroxytamoxifen-induced cell death and the development of antiestrogen resistance

This study identifies macroautophagy as a key mechanism of cell survival in estrogen receptor-positive (ER+) breast cancer cells undergoing treatment with 4-hydroxytamoxifen (4-OHT). This selective ER modifier is an active metabolite of tamoxifen commonly used for the treatment of breast cancer. Our study provides the following key findings: (a) only 20% to 25% of breast cancer cells treated with 4-OHT in vitro die via caspase-dependent cell death; more typically, the antiestrogen-treated ER+ breast cancer cells express increased levels of macroautophagy and are viable; (b) 4-OHT-induced cell death, but not 4-OHT-induced macroautophagy, can be blocked by the pan-caspase inhibitor z-VAD-fmk, providing strong evidence that these two outcomes of antiestrogen treatment are not linked in an obligatory manner; (c) 4-OHT-resistant cells selected from ER+ breast cancer cells show an increased ability to undergo antiestrogen-induced macroautophagy without induction of caspase-dependent cell death; and (d) 4-OHT, when used in combination with inhibitors of autophagosome function, induces robust, caspase-dependent apoptosis of ER+, 4-OHT-resistant breast cancer cells. To our knowledge, these studies provide the first evidence that macroautophagy plays a critical role in the development of antiestrogen resistance. We propose that targeting autophagosome function will improve the efficacy of hormonal treatment of ER+ breast cancer.     

老年性痴呆与血管性痴呆患者睡眠障碍的对照研究

目的:研究老年性痴呆(AD)和血管性痴呆(VD)患者睡眠障碍的特点及相关性。方法:对31例AD患者和30例VD患者采用阿森斯(Athens)失眠量表调查评分及临床资料比较分析。对研究对象进行筛选分组。从8个方面详细记录睡眠情况,按量表现规定进行评定。结果:AD患者和VD患者总体睡眠状况比较有显著性差异(t=2.251,P<0.05)。睡眠状况各因子比较,在总睡眠质量、白天情绪、白天思睡等3个方面无显著性差异(P>0.05)。在早醒、白天身体功能方面,两者有极显著差异(P<0.01)。在入睡时间、夜间苏醒、总睡眠时间等两者存在显著性差异(P<0.05)。结论:AD患者和VD患者都有睡眠障碍,AD患者在早醒、白天身体功能、夜间苏醒、总睡眠时间等方面都比VD患者差,而VD患者在入睡时间上比AD患者明显延迟。