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。     

A Comparative Study on the Effect of BCG-PSN and Thymopeptides on T-lymphocyte Subsets of Normal and Immunosuppressed Mice

Polysaccharidenucleicacidfractionofbacilluscalmetteguerin (BCG PSN ,SiqikangInjection)andthymopeptidesarenowtwowidelyusedimmunomod ulatorsinclinicalpractice .Theyareusuallyusedasanadjuvanttherapyforvirusinfection ,autoimmunediseasesandneoplasms ,whichhavebeenclinicallyprovedtobeeffective .Somereportsdemonstratedthattheybothcanstimulatetheproliferationanddif ferentiationofT lymphocytes.However ,theexactmechanismshavenotbeenelucidatedyet .InordertocomparetheirmodulatingmechanismsonT lympho c…     

香烟烟雾吸入对大鼠局灶性脑缺血后梗死灶的影响

目的 观察香烟烟雾吸入对大鼠局灶性脑缺血后梗死灶的影响，探讨其机制。方法 建立吸烟大鼠模型。用TTC染色法测定梗死灶体积，检测大鼠局灶性脑缺血后神经功能缺陷评分及梗死灶体积占同侧半球百分比。结果 除戒烟组外各吸烟组大鼠神经功能缺陷评分及梗死灶体积与对照组相比显著增加，吸烟4周、8周及12周依次增加。戒烟组神经功能评分及梗死体积明显低于吸烟4周组，与对照组无显著差别。结论 吸烟可加重大鼠局灶性脑缺血后脑组织损害，且随着吸烟时间增加而加重，戒烟可使这种脑损害得到一定程度的恢复。     

重视心血管病流行病学研究工作

自 2 0世纪 90年代 ,心血管病已逐渐成为我国城乡居民的第一位死因 ,目前已占总死亡人数的近40 %。心血管病也是造成劳动力损失、生活质量下降、疾病负担增加的主要原因。据不完全统计资料估计 ,我国每年新发冠心病事件 (包括急性心肌梗死、冠心病猝死和慢性冠心病死亡 )约 1 3 0万例次 ,脑卒中约 40 0万例次。全国现有 1 .1亿高血压患者 ,1亿多血脂异常者 ,3 0 0 0万糖尿病患者。人群中有一半以上的人至少具有 1种心血管病危险因素。心血管疾病以其高发病率、高致残率、高病死率及高治疗费用 ,严重制约了我国经济发展和人民生活水平及生存…     

The predictive value of specific immunoglobulin E levels for the first diagnosis of cow''s milk allergy. A critical analysis of pediatric literature

Investigators have tried to identify a level of seric specific immunoglobulin E (IgE) that had a sufficient predictive value to diagnose a food allergy without having will resort to the food challenge. To search in literature, all the studies that have estimated the possibility to identify a level of seric specific cow milk IgE with a positive predictive value (PPV) of 95% for the first diagnosis of cow's milk allergy (CMA) in pediatric age. We have identified six studies, nearly all studies suffer from relevant methodological bias. Proposed cut-off are all different. The studied pediatric populations were highly selected. Also neglecting the methodological bias of the studies and the great difference of value between the proposed cut-off, it always remains to consider that the pre-test probability of having a CMA between the children enrolled in the six studies included in this review is particularly high. The likelihood ratio helps to transfer the results of a study on a diagnostic test just to our population, and it is more realistic rather than to entrust itself to the PPV or the negative predictive value, that are much influenced from the prevalence of the disease in the studied population.