Structure-intestinal transport and structure-metabolism correlations of some potential cancerostatic pyrimidine nucleosides in isolated rat jejunum

Summary Both transport and biotransformation processes for a series of pyrimidine nucleobases, ribonucleosides, 2-deoxyribonucleosides, and acetyl and 5-substituted derivatives of the cancerostatic agent araC were studied in the isolated everted rat jejunum with a continuous perfusion technique. Metabolic alterations during penetration were assessed by HPLC. 5-Halogeno and 5-deoxy derivatives of cytosine nucleosides exhibited higher transport rates and higher stability towards the deamination reaction than did unsubstituted derivatives. Octanol-buffer partition coefficients were estimated for the study compounds, and fragmental constants for the sugar moieties of nucleosides were assessed. With the present study compounds there was no correlation between lipophilicity and transport rate, as previously reported, but there was a correlation between lipophilicity and metabolic alteration of araC derivatives (r=0.99, n=5).     

Flattening the quality of life curve? A prospective person-centred study from Norway amid COVID-19

Quality of Life Research - We examined multidimensional, heterogeneous reactions to the COVID-19 pandemic and associated measures to provide further insights into the developmental processes of...     

Can Policy Promote Adoption or Outcomes of Evidence-based Prevention Programming?: a Case Illustration of Positive Behavioral Interventions and Supports

Prevention Science - This study examined the impact of a state policy requiring that any school with a habitual truancy rate of 8% or higher to be trained in Tier 1 school-wide Positive Behavioral...     

通州市医疗卫生单位消毒质量动态比较观察

对1997～2000年通州市医疗卫生单位消毒质量监测结果进行动态比较,显示消毒质量正在稳步提高,并以2000年为最佳,县级医疗卫生单位明显优于乡镇卫生院。     

饮食服务业从业人员乙型肝炎病毒感染动态研究

目的为了解泰安市饮食服务业从业人员乙型肝炎病毒感染状况。方法应用ELISA方法在1995～1999年对53434名饮食服务业从业人员进行了血清HBsAg、抗-HBc、HBeAg和抗-HBe检测。结果1995～1999年饮食服务业从业人员血清HBsAg、抗-HBc、HBeAg和抗-HBe总阳性率呈逐年下降趋势,依次为4.41%、3.88%、3.46%、2.86%和2.50%,其差异有显著意义（χ     

低铅染毒大鼠体内脂质过氧化及抗氧化水平改变

目的：观察低剂量铅染毒后大鼠体内脂质过氧化水平改变,为铅的毒作用机制研究提供依据。方法：以醋酸铅为受试物,雄性Wistar大鼠为受试对象,分别观察其脏器脂质过氧化水平改变。结果：低铅染毒后,大鼠各脏器超氧化物歧化酶（SOD）、谷胱苷肽过氧化物酶（GSH－Px）及过氧化脂质（LPO）均有不同程度改变（P＜0.05,P＜0.01）,而巯基（－SH）含量仅肝脏变化较明显。结论：较低剂量的铅即可引起体内脂质过氧化水平的改变,而这种变化可能是铅的毒作用途径之一。     

三氧化二砷诱导肺癌细胞凋亡及对细胞周期的影响

目的 :探讨三氧化二砷 (As2 O3 )对人肺癌细胞株 (Spc- A1)诱导凋亡的机制 ,为抗肿瘤药物的筛选和用药方式提供理论依据。方法 :体外培养 Spc- A1细胞株与不同浓度的 As2 O3 进行作用 ,应用 MTT比色法、流式细胞仪技术、电子显微镜技术观察细胞增殖率、细胞周期率、细胞凋亡率及亚细胞水平变化。结果 :As2 O3 能够抑制 Spc- A1细胞的增殖 ,且呈时间剂量依赖性 ,Spc- A1细胞凋亡率与药物浓度和时间呈依赖关系。电镜观察细胞线粒体肿胀、空泡 ,染色质浓缩、核碎裂。结论 :As2 O3 可诱导 Spc- A1细胞凋亡 ,细胞周期延长 ,线粒体变性。     

Study of therapeutic mechanism of acupuncture in treating bronchial asthma

Ｉｔｈａｓｂｅｅｎｃｏｎｓｉｄｅｒｅｄｂｙｍｏｄｅｒｎｍｅｄｉｃｉｎｅｔｈａｔｂｒｏｎｃｈｉａｌａｓｔｈｍａｉｓａｃｈｒｏｎｉｃａｉｒｗａｙａｌｌｅｒｇｉｃｉｎｆｌａｍｍａｔｉｏｎ（ＡＡＩ）ｗｈｉｃｈｉｓｔｈｅｍａｊｏｒｆａｃｔｏｒｔｈａｔｉｎｄｕｃｅｓｒｅｖｅｒｓｉｂｌｅａｉｒｗａｙｖｅｎｔｉｌａｔｉｎｇｄｉｓｔｕｒｂａｎｃｅａｎｄｂｒｏｎｃｈｉａｌｈｙｐｅｒ ｒｅ ｓｐｏｎｓｉｖｅｎｅｓｓ（ＢＨＲ）ｉｎａｓｔｈｍａｔｉｃｐａｔｉｅｎｔｓ,ａｓｗｅｌｌａｓａｃｏｒｒｅｌａｔｉｏｎｂｅｔｗｅｅｎｔ…     

Efficacy of non-ablative fractional 1440-nm laser therapy for treatment of facial acne scars in patients with rosacea: a prospective,interventional study

Lasers in Medical Science - Acne scarring is one of the most common facial skin disorders. The appropriate treatments for acne scars in patients with rosacea have not been studied. This study was...