中药安迪注射剂对人食管癌细胞的放射增敏作用

目的 :观察安迪注射剂 (Andi)对电离辐射生物学效应的影响。方法 :人食管癌细胞株 (ECA 10 9)在富氧 (空气 )和缺氧 (通 99 99%的高纯氮气 5 0min)条件下分别观察对照组、Andi组、60 Co γ线辐射和Andi +60 Co γ线辐射 4组细胞形态 (光镜 )、细胞倍增时间 (TD)、存活率 (SR)及集落存活分数 (SF)。结果 :光镜下可见Andi组、辐射组、Andi+辐射组癌细胞变性、坏死、凋亡 ,以Andi +辐射组为最显著。MTT法测定对照组、Andi组、60 Co γ线辐射和Andi+60 Co γ线辐射四组缺氧细胞的TD(% )分别为 4 6 12 ,118 72 ,6 2 81,171 0 2h ,SR分别为 10 0 % ,4 2 % ,86 % ,30 % ;各治疗组与对照组比较TD 和SR均相差显著 (P <0 0 5 )。方差分析显示 ,辐射在富氧 (F =90 19,P =0 0 0 0 1)和缺氧 (F =37 0 9,P =0 0 0 0 3)时均为SF的影响因素 ;Andi仅在缺氧时对SF是有意义的影响因素 (F =2 9 0 4 ,P =0 0 0 0 7) ,与60 Co γ线辐射合用对缺氧细胞SF的影响具有协同作用 (F =11 37,P =0 0 0 98)。用单靶多击模型拟合数据分析 ,Andi的放射增敏比 (SER)为 1 5 ,相对敏化效应 (RSE)为 5 5 %。结论 :Andi对缺氧ECA 10 9细胞具有明显的细胞毒和放射增敏作用。     

Signal-to-noise ratio effects in quantitative cerebral perfusion using dynamic susceptibility contrast agents.

Theoretical and simulation evidence is presented in support of the idea that the optimal manner of determining blood flow from MR perfusion studies is not necessarily obtained by setting experimental conditions to maximize either the arterial input or the measured tissue concentration level for a particular echo time (TE). The noise power in the contrast concentration curve is associated with its peak because of the nonlinear relationship between the contrast concentration and MR signal intensity curves. The optimum signal-to-noise ratio (SNR), SNR(C), for a particular contrast concentration curve can be obtained when the experimental concentration level and TE are adjusted to produce an MR intensity curve whose signal loss is 63% of the precontrast MR signal intensity. It is demonstrated that the stability of the singular valued decomposition (SVD) deconvolution approach to determine blood flow parameters is increased when the tissue curve maximum signal loss is in the range of 40-80%. The accuracy and stability of the SVD-determined blood flow parameters are affected by deviations from these optimum conditions in a manner that depends on the mean transit time (MTT) associated with the residue function. It is recommended that the experimental TE value be set so that neither the tissue nor the arterial curves are placed a region of rapidly deteriorating SNR(C).     

Heroin self-administration in rats under a progressive ratio schedule of reinforcement

Heroin self-administration behavior under a progressive ratio (PR) schedule of reinforcement was evaluated in rats. The schedule was designed to restrict drug intake, minimize opiate dependency, and quantify the number of responses emitted (final response ratio) in order to receive a limited number of heroin infusions. Final ratios were found to be stable and did not increase with chronic (31 days) PR reinforcement. The ability of the PR schedule to detect changes in heroin reinforcement was demonstrated by evaluating the effect of naltrexone pretreatment and unit dose alteration on final ratios. Naltrexone (0.4 mg/kg) reduced final ratios and an inverted U dose-response relationship was established for the unit heroin doses 12.5–100 µg/injection. Maximal final ratios occurred with 50 µg/injection heroin reinforcement. This PR schedule may provide a useful method for evaluating the effects of pharmacological manipulations or lesions on opiate reinforcement.     

Self-administration of GBR 12909 on a fixed ratio and progressive ratio schedule in rats

Intravenous self-administration of GBR 12909, an indirect dopamine agonist, was examined on a Fixed Ratio (FR 1) and a Progressive Ratio (PR) schedule of reinforcement in rats. Subjects were first trained to self-administer cocaine (1.5 mg/kg/inj) during daily 5 h sessions, after which GBR 12909 (0.187–1.5 mg/kg/inj) was substituted. On the FR 1 schedule, the inter-infusion interval for GBR 12909 self-administration was directly related to dose and was approximately three times longer than that established for equivalent doses of cocaine. Breaking points on the PR schedule were comparable for GBR 12909 and cocaine self-administration. The data indicate that, compared to cocaine, GBR 12909 has a longer duration of action and a similar reinforcing efficacy.     

水稻亚种间杂种优势利用研究

本试验探讨了华南双季稻区利用亚种同杂种优势的特点和问题,结果表明:当前,两系亚种问杂种一代主要存在的问题是结实率低和谷草比低;籼粳交杂种易受环境条件的影响;每穗实粒数和单株有效穗数是决定单株产量的重要因子;每穗实粒数增加的关键在于结实率的提高,本文还就提高结实率和谷草比等问题提出了意见。     

pH指示剂吸收度比值法测定盐酸乙胺丁醇的含量

本文报道pH指示剂吸收度比值法测定盐酸乙胺丁醇的含量。该法采用指示剂为0.05%茜素黄R,测定波长374nm和500nm;标准液为0.1mol/L NaOH;仪器为WFZ-800D_2型分光光度计。测得三批盐酸乙胺丁醇的含量分别为99.5±0.04%,99.4±0.05%和99.6±0.03%.同时与药典法比较,结果一致。     

儿童边缘性锌缺乏症综合判断的研究

对沈阳市某幼儿园９９例３～６岁锌缺乏儿童的营养调查和生物样品（血液、尿液和毛发）的分析发现：同对照组儿童相比，锌缺乏儿童除Ｆｅ、维生素Ａ外，其他主要营养素的摄入明显不足；缺锌儿童的发锌、ＲＢＣ锌水平、血清ＡＬＰ活性、尿锌／尿肌酐比值均明显低于对照组。经补锌治疗后血浆锌水平、血清ＡＬＰ活性、尿锌／尿肌酐比值显著升高。应用临床诊断实验的评价方法分析发现结合血浆锌水平，联合使用发锌，血清ＡＬＰ和尿锌／尿肌酐比值３项指标可以准确判断儿童边缘性锌缺乏，这时并联的灵敏度为９６．１８％，串联的特异度可高达到１００％（血清ＡＬＰ活性＜１０４ＩＵ／Ｌ，同时发锌含量＜１１０ｐｐｍ．尿锌／尿肌酐比值＜０．３μｇ／ｇ）。     

Effects of food deprivation on cocaine base smoking in rhesus monkeys

Studies have shown that both food deprivation and response cost have important influences on the magnitude of self-administration of a wide variety of psychoactive drugs. In an attempt to extend these findings to the smoked route of drug self-administration, the effects of food allotment and fixed-ratio (FR) value were evaluated in four male rhesus monkeys trained to smoke cocaine base. In the first phase of the experiment, monkeys were trained to self-administer smoked cocaine base under a chained progressive-ratio (PR), fixed-ratio (FR) schedule during daily experimental sessions. Monkeys were required to make 20 lever-press responses and then five inhalations on a smoking spout to obtain the first smoke delivery. The lever ratio then increased to 60, 140, 300, 620, 1260, 2540, and 4940 for each successive smoke delivery. The initial lever ratio value was reset to 20 at the beginning of each daily session. The body weights of three monkeys were determined under free-feeding conditions. Monkeys were then restricted to 100 g food and, when body weights had stabilized, the daily food allotment was increased to 150 g, approximately 210 g, or greater than 400 g (satiation). As the daily food allotment and body weight increased, the mean number of smoke deliveries decreased in two of three monkeys. In the second phase of the experiment, three monkeys were maintained under either food-satiated or food-restricted conditions. Body weights were maintained at approximately 90% of their free-feeding weights under food-restricted conditions. The cost of the drug (lever FR value) was constant within each experimental session, but was increased after 3 consecutive days of stable responding. Fixed-ratio values were increased from 128 to 256, 512, 1024, and 2048. Monkeys were required to complete the lever FR value and then to make five inhalations on the smoking spout to gain access to 1.0 mg/kg per delivery cocaine base. The mean number of smoke deliveries increased at FR 256, 512, and 1024 when monkeys were food-restricted as opposed to food-satiated. Correspondingly, the mean number of responses increased under food-restricted conditions. Responding continued to increase over a wider range of FR values, and the peak number of responses was higher under food-restricted, as opposed to food-satiated conditions. These results, using the smoking route of administration, are consistent with the hypothesis that food deprivation increases the self-administration of reinforcing drugs.     

老年2型糖尿病患者胰岛素抵抗相关指标的检测和意义

目的:探讨老年2型糖尿病胰岛素抵抗(IR)及其相关性,为老年2型糖尿病的合理防治提供临床依据。方法:选择120例老年2型糖尿病患者,按胰岛素敏感指数(HOMA)胰岛素抵抗(HOMA-IR)50百分位点将患者分为两组:胰岛素相对敏感组(HOMA-IR<3.56)和胰岛素相对抵抗组(HOMA-IR≥3.56),比较体重指数(BMI)、腰/臀比(WHR)、血压、血生化学检查等指标。用年龄>40岁,<60岁的2型糖尿病患者做对照组。结果:两组老年患者在年龄、性别、舒张压、空腹血糖、胆固醇、高密度脂蛋白、糖化血红蛋白、HOMA胰岛β细胞功能方面无差异;但BMI、WHR、收缩压、甘油三脂、空腹胰岛素、HOMA-IR差异具有显著性。多线性回归分析后,只有腰/臀比、收缩压、甘油三脂、HOMA-IR存在统计学差异。老年患者与对照组相比,IR发生率明显增加,且两者腰/臀比、收缩压、甘油三脂方面也差异显著。结论:IR与老年2型糖尿病密切相关,是临床防治糖尿病的重要靶点。