Nonshivering thermogenesis in adult and aged C57BL/6J mice housed at 22°C and at 29°C

Twelve- and 28-month-old C57BL/6J male mice were housed either at room temperature of 22°C or at thermoneutrality (29°C) during the two months prior to experiments. Acute experiments were conducted under anesthesia, myorelaxation, and artificial ventilation. We recorded efferent electrical impulse activity in one of the sympathetic nerves innervating the interscapular brown adipose tissue in response to acute cold stimulation, when body temperature was lowered 7.5°C below control level. In separate experiments we measured O₂ consumption and CO₂ production and calculated the nonshivering thermogenesis. We also measured the concentration of uncoupling protein in interscapular brown adipose tissue before and after three-hour cold stress. In aged mice, both sympathetic nervous activity and nonshivering thermogenesis were lower in animals housed at thermoneutrality (29°C) than in mice housed at 22°. Among mice maintained at 22°C, but not at thermoneutrality, aged animals had greater nonshivering thermogenesis and greater cold induced concentration of uncoupling protein in the brown adipose tissue than adults. Sympathetic nervous outflow to brown adipose tissue was always greater in aged mice, regardless of the temperature of acclimation. We concluded that aged mice, housed at 22°C, showed the changes in nonshivering thermogenesis associated with cold acclimation. However, an increased sympathetic outflow to brown adipose tissue in aged animals reflects an age-related elevation of the tone and responsiveness of the sympathetic nervous system.     

薄层色谱－紫外分光光度法测定抗毒退热冲剂中绿原酸含量

用薄层色谱－紫外分光光度法测定了抗毒退热冲剂中绿原酸的含量。以乙酸乙酯－甲醇－水（１０∶２∶３）为展开剂，测定波长３２７ｎｍ。在测定范围内吸收度与被测物浓度线性相关，ｒ＝０．９９９７，回收率９９．０３％（ｎ＝５），ＲＳＤ２．７７％。     

Quantitative analysis of cold stress performance after digital replantation

Isolated cold stress testing (ICST) has been used to assess cold stress performance or digital thermoregulation, but statistical analysis of the results has been limited to visual comparisons of data. In this prospective study, 11 patients who underwent complete digital replantation were followed serially with ICST at 6 weeks, 3 months, 6 months, 1 year, and 2 years postoperatively, and the results were analyzed quantitatively. For that analysis, we devised a mathematical method that provided a cooling and a warming coefficient to fit the data. Differences in these cooling and warming coefficients were then regressed against time after replantation, patient age, number of digits replanted, hand dominance, and clinical evidence of sensory recovery. There was a significant correlation between response to isolated cold stress testing (thermoregulation) and degree of sensory recovery (p less than or equal to 0.02). This method for quantitative analysis of isolated cold stress testing data allows objective evaluation of digital blood flow patterns based on temperature, thereby providing a reliable and objective assessment of the recovery of thermoregulation in the replanted human digit.     

Stronger nasal responsiveness to cold air in individuals with rhinitis and asthma, compared with rhinitis alone

BACKGROUND: We have previously proposed that, compared with rhinitis alone, the constellation of upper and lower airway allergic disease is a manifestation of a more severe form of a syndrome affecting the entire airway. If this is correct, not only the lower, but also the upper airways of patients with asthma and rhinitis should demonstrate more abnormalities compared with patients with rhinitis alone, including higher sensitivity to irritant factors. Objective To test the hypothesis that, a previously well-studied natural nasal stimulus, cold, dry air (CDA), produces a stronger response in subjects with allergic rhinitis (AR) and asthma compared with subjects with AR alone. METHODS: We performed nasal provocation with CDA on 24 individuals with asthma and rhinitis and 17 with rhinitis alone. Prior to and after the challenge, nasal symptoms were recorded using visual analogue scales and nasal lavages were performed to determine histamine and lysozyme levels. RESULTS: The two groups reacted differently to CDA: after the challenge, patients with rhinitis and asthma reported significantly higher scores for nasal congestion, rhinorrhea and lacrimation. Also in this group, significant increases in histamine and in lysozyme levels in nasal lavage fluids were induced by CDA. In subjects with rhinitis alone, CDA failed to increase histamine or lysozyme levels above baseline. The CDA-induced change from baseline in histamine was significantly higher in the patients with rhinitis and asthma, compared with the rhinitis-only group. CONCLUSION: Patients with AR and asthma have stronger nasal responsiveness to CDA compared with patients with rhinitis alone. This observation is consistent with the notion that compared with rhinitis alone, the presence of asthma and rhinitis signifies a higher degree of functional abnormality of the entire airway.     

芦荟全叶粉90天亚慢性毒性研究

为了观察芦荟全叶粉长期食用对健康的影响 ,选用健康断乳SD大鼠 88只 ,随机分为 4组 ,每组 2 2只 ,雌雄各半 ,分别给予芦荟全叶粉 0、2、4、8g kgBW (按 0、2 5%、5%、10 %比例 )掺入基础饲料喂饲 90天。结果表明 ,芦荟全叶粉使大鼠排便量增加 ,粪便松软 ;雄性 8g kgBW剂量组大鼠体重增长明显缓慢 (P <0 0 1)、食物利用率降低 (P <0 0 1) ,4g kgBW剂量组食物利用率下降 (P <0 0 5) ,体重影响不明显 ,2g kgBW剂量组和雌性各剂量组对大鼠体重、食物利用率无影响。雄性 8g kgBW剂量组和雌性各剂量组肾 体比值增大 (P<0 0 1) ,4、8g kgBW剂量组睾丸 体比值增大 (P <0 0 5)。芦荟全叶粉对大鼠血液学指标 ,尿NAG酶 ,血清转氨酶、血脂、肌酐等生化指标无影响 ,8g kgBW剂量组血清BUN升高 (P <0 0 1)。病理检查 ,除 2g kgBW剂量组结肠粘膜无色素沉积外 ,各剂量组均可引起肾小管上皮、肠系膜淋巴结、结肠粘膜固有层色素沉积和肠系膜淋巴结增生 ,而肝、脾、睾丸 (或卵巢 )等脏器未见有意义的病理改变。本实验条件下 ,芦荟全叶粉有作用剂量为 2g kgBW (芦荟甙 11 8mg kgBW )。     

斩龙剑化学成分的研究

观察了某部队６０名人员在寒冷情况下，摩步化行军、露营、复合性应激后有关消化道激素的变化，结果提示５小时行军３小时露营后立即测定的ＰＲＬ、ＧＨ、Ｆ值明显高于行军露营前的水平（Ｐ＜０．０１），ＧＡＳ、ＧＣ升高（Ｐ＜０．０５），ＩＮＳ降低（Ｐ＜０．０１）。分析Ｆ通过ＧＡＳ的升高造成应激性胃肠损害；而ＧＣ升高、ＺＮＳ降低对应激性胃肠损害有一定的保护作用。     

人参多糖、刺五加提高冷适应能力的研究

本文选择入伍二年北方籍战士６０人，分成１Ⅰ、Ⅱ、Ⅲ组，分别服用人参多糖、刺五加和安慰剂口服液。观察服用上述药物是否有提高和加速冷适应能力的作用。其结果（１）Ⅰ、Ⅱ组尿ＶＭＡ排出量第１０、２０ｋ与实验前比有明显增加（Ｐ＜０．０５和Ｐ＜０．０１），Ⅲ组尿ｖＭＡ排出量低于Ⅰ、Ⅱ组（Ｐ＜０．０５）。（２）血液流变学指标（全血粘度，总周阻力，微循环半更新时间，心肌氧耗指数）Ⅰ、Ⅱ组比实验前有明显差异（Ｐ＜０．０５）。（３）手指在０℃冰水中，实验前三组均有疼痛感，服药期间第５、１０天，Ⅰ、Ⅱ组与实验前比较，疼痛者明显减少（ｐ＜０．０５和ｐ＜０．０１），第２０天Ⅰ、Ⅱ组已无疼痛者，而Ⅲ组仍有２０％人有疼痛。通过本次实验观察说明，此二药可能有提高或促进冷习服作用。