Sensitivity to cinnamic aldehyde in a toothpaste. 2. Further studies

The authors carried out further studies to assess the significance of the findings of patients sensitive to cinnamic aldehyde in a toothpaste. Selected groups of patients in whom sensitivity to this might have been overlooked were patch-tested. With the exception of three patients, two with cosmetic sensitivity and one with hand eczema, the results were negative. The frequency of use of the original toothpaste was assessed among patients attending the clinic and this was followed by a circular letter to general practitioners and dentists inviting referral of patients with oral symptoms. As a result, five further cases, four of whom gave positive patch test reactions to cinnamic aldehyde, were discovered. The authors emphasize the importance of attempting to obtain accurate information as quickly as possible when 'new' or hitherto unsuspected allergens are implicated.     

Interaction of di-(2-ethylhexyl) phthalate with the pharmacological response and metabolic aspects of ethanol in mice

The interactions of di-(2-ethylhexyl) phthalate (DEHP) with the pharmacological response and metabolic aspects of ethanol in mice were investigated at oral doses of DEHP of 1.5, 3.0 and 7.5 g/kg or intraperitoneal doses of 3.7, 7.5 and 18.9 g/kg, administered once or daily for 7 days. A single oral or intraperitoneal administration of DEHP resulted in a significant increase in the ethanol-induced sleeping time, associated with an inhibition of alcohol dehydrogenase activity in liver; the effect of intraperitoneal administration was significant only at the highest dose. The activities of high and low Km aldehyde dehydrogenases in mouse liver were not affected by a single dose of DEHP by either route. Repeated oral doses of DEHP produced significant reductions in the ethanol-induced sleeping time and increases in the activities of alcohol and aldehyde dehydrogenases, whereas repeated intraperitoneal doses of DEHP significantly increased the sleeping time and decreased the activity of alcohol dehydrogenase, without any perceptible effect on the activities of aldehyde dehydrogenases. In vitro studies with mouse liver preparations revealed significant inhibition of alcohol dehydrogenase activity by mono-(2-ethylhexyl) phthalate and 2-ethylhexanol and of high and low Km aldehyde dehydrogenase activities by DEHP and mono-(2-ethylhexyl) phthalate at concentrations ranging from 0.03 to 1.00 mM. In all cases, in vitro enzyme inhibition by mono-(2-ethylhexyl) phthalate was most pronounced.     

Influence of the Diet on the Metabolism of Acetaldehyde in Rats

Abstract The acetaldehyde dehydrogenases of rat liver, the hepatic output of acetaldehyde and the rate of ethanol elimination were studied in two groups of female Sprague-Dawley rats fed on two different commercial standard diets (diet 1 and diet 2). The activity of the mitochondrial low-K_m enzyme was 2–3 times lower in rats fed on diet 1 as compared to rats fed on diet 2, whereas only slight differences were found in the activities of the high-K_m enzymes in the mitochondrial, the microsomal and the cytosol fractions. No differences were observed between the two groups in the activities of alcohol dehydrogenase, glutamate dehydrogenase, glucose-6-phosphatase or malic enzyme. The rate of ethanol elimination was 15 % lower, and the acetaldehyde level in the blood was 2–4 times higher in rats fed on diet 1 as compared to rats fed on diet 2. When the diets were interchanged between the two groups, the activity of the low-K_m enzyme increased or decreased twofold within 12 hrs. Starvation increased the activity of the low-K_m enzyme in rats fed on diet 1, but had no effect on the activity in rats fed on diet 2. The results suggest that diet 1 contains an inhibitor of the low-K_m enzyme, and that dietary factors may be of importance in the regulation of the hepatic output of acetaldehyde during ethanol metabolism.     

Fetal bovine bone marrow is a rich source of CD34+ hematopoietic progenitors with myelo-monocytic colony-forming activity

The CD34 glycoprotein is an important marker of hematopoietic stem cells. We used a polyclonal rabbit anti-bovine CD34 antibody to stain fetal and adult bovine bone marrow cells. Flow cytometry revealed a low side scatter (SSC^low) population of cells that were CD34⁺ but negative for leukocyte lineage markers CD11b, CD14 or CD2. Hematopoietic colony assays with CD34⁺ and CD34⁻ bone marrow cells suggested that the colony-forming potential in SSC^low bone marrow cells was confined to the CD34⁺ fraction. In contrast, this population was not enriched for cells expressing high aldehyde dehydrogenase activity, a metabolic marker that has been used to characterize hematopoietic stem cells. Thus, the CD34 antigen can be used to identify and isolate bovine bone marrow cells exhibiting clonogenic potential in vitro. Moreover, the proportion of CD34⁺ cells is very high in fetal bovine bone marrow, indicating it as a rich source of hematopoietic progenitors.     

参姜锁阳益气片抗疲劳作用机制的研究

目的探索参姜锁阳益气片抗疲劳的作用机制。方法选择在-30℃以下的某地区驻训部队官兵210例,按随机数字表法分为两组:参姜锁阳益气片组130例和对照组80例,参姜锁阳益气片组口服参姜锁阳益气片,对照组口服安慰剂,服药前、服药2周后野外长跑3 000 m后观察各项客观指标的变化。结果①参姜锁阳益气片组血乳酸水平服药后为(3.03±1.95)mol/L,与服药前相比明显降低(P<0.05);②参姜锁阳益气片组血清乳酸脱氢酶、磷酸肌酸激酶水平服药后与服药前相比差异有统计学意义(P<0.05);③参姜锁阳益气片组运动后超氧化物歧化酶(SOD)活性及丙二醛(MDA)含量服药后与服药前相比显著降低(P<0.05)。结论参姜锁阳益气片可增强人体的运动适应能力,具有抗疲劳作用,该作用可能与其增强机体的抗氧化能力有关。     

桂皮醛对U937细胞增殖和凋亡的影响及其机制探讨

目的:探讨桂皮醛对急性髓系白血病细胞株U937的增殖和凋亡的影响及其相关机制.方法:以U937细胞为研究对象,CCK-8法测定细胞增殖活性;流式细胞术检测细胞周期、凋亡率、线粒体膜电位水平;ELISA法检测细胞上清液中VEGF浓度.结果:桂皮醛呈时间和剂量依赖性影响U937细胞生长.桂皮醛处理后U937细胞阻滞于G2/...     

酚试剂-分光光度法检测PVPK30和PVPVA64中的醛

目的建立检测PVPK30和PVPVA64中醛含量的酚试剂-分光光度法。方法取试样的水溶液,加酚试剂反应生成嗪,再加硫酸铁铵溶液,在酸性条件下,嗪被高铁离子氧化,生成蓝绿色稠合阳离子,在635nm波长处有吸收峰,用可见分光光度计测量吸光度。绘制乙醛标准溶液的标准曲线并据此计算试样中的醛。结果醛含量在0～44μg范围内（以乙醛为对照）与吸光度线性关系良好（R^2=0.9981）,回收率为93.60%～101.10%,PVPK30和PVPVA64的RSD分别为2.85%和1.35%（n=6）。结论与2005年版《中国药典（二部）》中的酸碱滴定法相比,所用方法具有较好的检出限、回收率和精密度,且能同时检测PVPVA64中的醛;与2001年版《欧洲药典》相比,该法检测对象更全面,所用试剂更经济、易购。     

高效液相色谱法测定舒冠片中原儿茶醛的含量

目的：建立高效液相色谱法测定舒冠片中原儿茶醛含量的方法。方法：色谱柱为Phenomenex C18柱（250mm×4．6mm,5μm）,以甲醇-1％醋酸溶液（12：88）为流动相,检测波长为279nm,流速为0．8ml·min^-1,柱温为24℃。结果：原儿茶醛在2．00～19．98μg·ml^-1,范围内线性关系良好（r=1．0000）,平均加样回收率为99．50％（RSD=0．71％）。结论：该方法简便、准确,重复性好,可作为舒冠片中原儿茶醛的含量测定方法。     

RP-HPLC法测定资木瓜中原儿茶酸的含量

目的：建立以RP—HPLC法测定资木瓜中原儿茶酸含量的方法。方法：色谱柱：Agilent Eclipse XDB—C18（250mmx4．6mm,5μm）,流动相：乙腈旬．1％磷酸水溶液（5：95）,流速1ml·min-1,检测波长260nm。结果：原儿茶酸进样量在0．02～0．20μg范围内具有良好的线性关系（r=0．9999）,平均加样回收率为101．23％,RSD为1．83％（n=5）。结论：本方法简便、准确、重复性好,可用于控制资木瓜的质量。