When the brain goes diving: glial oxidative metabolism may confer hypoxia tolerance to the seal brain

Deep diving mammals have developed strategies to cope with limited oxygen availability when submerged. These adaptations are associated with an increased neuronal hypoxia tolerance. Brain neurons of the hooded seal Cystophora cristata remain much longer active in hypoxic conditions than those of mice. To understand the cellular basis of neuronal hypoxia tolerance, we studied neuroglobin and cytochrome c in C. cristata brain. Neuroglobin, a respiratory protein typically found in vertebrate neurons, displays three unique amino acid substitutions in hooded seal. However, these substitutions unlikely contribute to a modulation of O₂ affinity. Moreover, there is no significant difference in total neuroglobin protein levels in mouse, rat and seal brains. However, in terrestrial mammals neuroglobin resided exclusively in neurons, whereas in seals neuroglobin is mainly located in astrocytes. This unusual localization of neuroglobin is accompanied by a shift in the distribution of cytochrome c. In seals, this marker for oxidative metabolism is mainly localized in astrocytes, whereas in terrestrial mammals it is essentially found in neurons. Our results indicate that in seals aerobic ATP production depends significantly on astrocytes, while neurons rely less on aerobic energy metabolism. This adaptation may imbue seal neurons with an increased tolerance to hypoxia and potentially also to reactive oxygen species, and may explain in part the ability of deep diving mammals to sustain neuronal activity during prolonged dives.     

Stable dry powder inhaler formulation of tranilast attenuated antigen-evoked airway inflammation in rats

Tranilast (TL) has been clinically used for the treatment of airway inflammatory diseases, although the clinical use of TL is limited because of its poor solubility and systemic side effects. To overcome these drawbacks, a novel respirable powder of TL (CSD/TL-RP) for inhalation therapy was developed using nanocrystal solid dispersion of TL (CSD/TL). Stability study on CSD/TL-RP was carried out with a focus on inhalation performance. Even after 6 months of storage at room temperature, there were no significant morphological changes in micronized particles on the surface of carrier particles as compared with that before storage. Cascade impactor analyses on CSD/TL-RP demonstrated high inhalation performance with emitted dose and fine particle fraction (FPF) of ca. 98% and 60%, respectively. Long-term storage of CSD/TL-RP resulted in only a slight decrease in FPF value (ca. 54%). Inhaled CSD/TL-RP could attenuate antigen-induced inflammatory events in rats, as evidenced by marked reduction of granulocytes in bronchoalveolar lavage fluid and inflammatory biomarkers such as eosinophil peroxidase, myeloperoxidase, and lactate dehydrogenase. These findings were consistent with decreased expression levels of mRNAs for nuclear factor-kappa B and cyclooxygenase-2, typical inflammatory mediators. Given these findings, inhalable TL formulation might be an interesting alternative to oral therapy for the treatment of asthma and other airway inflammatory diseases with sufficient dispersing stability.     

湿润烧伤膏联合乳酸依沙吖啶湿敷在高龄患者慢性伤口中的应用

慢性伤口是指愈合时限延长，不能正常自愈，而需借助外力才能愈合的伤口，多发于长期卧床、身体状况较差的高龄患者。伤口迁延不愈，严重影响了患者的生活质量。     

丹酚酸B对兔离体心脏缺氧再复氧损伤的保护作用

目的观察丹酚酸B对兔离体心脏缺氧-复氧损伤的保护作用。方法离体兔心脏Langendorff灌流,通氮气饱和的灌流液60min后再恢复含氧灌流液灌流60min,造成缺氧-复氧损伤;自动生化分析仪测定冠脉流出液中肌酸激酶(CK)和乳酸脱氢酶(LDH)活性;光学显微镜观察心肌组织结构改变。结果在缺氧的同时给予丹酚酸B0.3,1和3mg.L-l灌流60min,可降低心率,增加冠脉流量,降低冠脉流出液中CK和LDH的水平,心肌组织形态学损伤明显减轻。结论丹酚酸B对兔离体心脏缺氧-复氧损伤有明显的保护作用。     

不同生产厂家乳酸环丙沙星注射液质量考察

目的:比较不同厂家乳酸环丙沙星注射液的质量。方法:对国内、外4厂家产品的不溶性微粒、乳酸含量、乙二胺及有关物质、容器内表面吸附性能进行测定或观察。结果:所有被测产品各项指标均符合《中国药典》要求,除不溶性微粒外,其余指标不同厂家产品之间存在差异。结论:有必要对乳酸环丙沙星注射液中部分项目进行限量规定。     

乳酸环丙沙星淀粉微球的体外释药研究

目的：制备乳酸环丙沙星淀粉微球并对其体外释放行为进行考察。方法：采用反相乳液聚合法结合包埋载药法制备乳酸环丙沙星淀粉微球，应用体外恒温透析法考察其释药行为及影响因素，以紫外可见分光光度法测定并计算累积释药百分数。使用origin软件，将微球释药数据与载药微粒的主要释药方程进行拟合，以找出最佳拟合释药方程。结果：制备的乳酸环丙沙星淀粉微球置于生理盐水中约5小时后达到释放平衡，其释放行为受处方中球-药比和交联剂用量及释放介质的影响。该载药淀粉微球的释药行为最符合双指数双相动力学方程，即呈双相释放，前期为快速释放相，后期（5小时后）为缓慢释放相。结论：本制剂工艺切实可行，所得乳酸环丙沙星淀粉微球具有明显的缓释制剂特征。     

邻苯二甲酸二丁酯和苯并[a]芘联合染毒对大鼠睾丸支持细胞的影响

目的 探讨邻苯二甲酸二丁酯和苯并[a]芘单独或联合染毒对大鼠睾丸支持细胞增殖及乳酸分泌的影响.方法 分离纯化大鼠睾丸支持细胞,油红O染色鉴定纯度大于90%后,以0.1、1、10、100、500 μg/ml 邻苯二甲酸二丁酯(dibutyl phthalate,DBP)和0.01、0.1、1、10、100 μg/ml 苯并[a]芘[benzo(a)pyrene,BaP]单独或依次联合染毒,用MTT法检测对支持细胞增殖的影响,并测定培养液中的乳酸含量.结果 DBP染毒后100 μg/ml 吸光度值[D(490)]显著高于对照组(P＜0.01).BaP染毒各组的D(490)值与对照组比较,无统计学差异.DBP 100 μg/ml BaP 10 μg/ml联合染毒组D(490)值显著上升(P＜0.01),而在500 μg/ml DBP 50 μg/ml BaP联合染毒组D(490)值下降(P＜0.05).DBP 100 μg/ml组、 100 μg/ml DBP 10 μg/ml BaP组和500 μg/ml DBP 50 μg/ml DBP组培养液中的乳酸显著增加(P＜0.01),DBP 500 μg/ml组和BaP 50 μg/ml组培养液中的乳酸含量也增高(P＜0.05).结论 一定剂量DBP可刺激支持细胞增殖并增加乳酸分泌,BaP虽不抑制支持细胞的增殖,但可使乳酸分泌增加.二者联合作用,在一定剂量下以DBP的效应为主,但在高剂量可抑制细胞增殖,呈现一定的协同作用.     

绞股蓝总皂甙对小鼠腹腔巨噬细胞内酶活性及吞噬功能的影响

目的 探讨绞股蓝总皂甙对小鼠腹腔巨噬细胞内酶活性和吞噬功能的影响.方法 将40只小鼠随机等分为空白对照组和三种剂量实验组.空白对照组用生理盐水灌胃,实验组用不同剂量绞股蓝总皂甙灌胃,14 d后检测小鼠腹腔巨噬细胞内酸性磷酸酶、乳酸脱氢酶活性及巨噬细胞吞噬功能的变化.结果 不同剂量实验组小鼠腹腔巨噬细胞内酸性磷酸酶及乳酸脱氢酶活性和吞噬能力较空白对照组增强明显;高、中剂量实验组较低剂量组对巨噬细胞酶活性及吞噬能力增强明显.结论 绞股蓝总皂甙对小鼠腹腔巨噬细胞内酸性磷酸酶、乳酸脱氢酶活性及巨噬细胞吞噬功能有增强作用,且存在一定剂量效应.