Purine nucleoside phosphorylase, a possible histochemical marker for T-cells in man.

A procedure is described for the histochemical detection of purine nucleoside phosphorylase (PNP) activity in circulating lymphocytes of man. The number of PNP-positive cells, as evaluated on smears of Ficoll--Hypaque purified cells, correlated well with the number of E-rosette-forming cells of the same blood samples of healthy and diseased people with normal or abnormal numbers of E-rosettes. In healthy people, the number of PNP-positive cells was within the range of 70-80% of the total lymphocyte population, whilst the corresponding E-rosette-forming cells were scored between 60-75%. Patients with unusually low or high E-rosettes had equally low or high numbers of PNP-reactive cells. More substantial evidence for the presence of PNP activity in T-cells and not in B cells was gathered from experiments in which PNP activity and surface membrane immunoglobulins (SMIg) were simultaneously demonstrated on the same preparation. These results showed, on the one hand, that the bulk of lymphocytes that are reactive for PNP do not reveal SMIg and, on the other hand, that most Ig-bearing cells were unreactive for PNP.     

Fetal bovine serum and human constitutive androstane receptor: Evidence for activation of the SV23 splice variant by artemisinin,artemether, and arteether in a serum-free cell culture system

The naturally occurring SV23 splice variant of human constitutive androstane receptor (hCAR-SV23) is activated by di-(2-ethylhexyl)phthalate (DEHP), which is detected as a contaminant in fetal bovine serum (FBS). In our initial experiment, we compared the effect of dialyzed FBS, charcoal-stripped, dextran-treated FBS (CS-FBS), and regular FBS on the basal activity and ligand-activation of hCAR-SV23 in a cell-based reporter gene assay. In transfected HepG2 cells cultured in medium supplemented with 10% FBS, basal hCAR-SV23 activity varied with the type of FBS (regular > dialyzed > CS). DEHP increased hCAR-SV23 activity when 10% CS-FBS, but not regular FBS or dialyzed FBS, was used. With increasing concentrations (1–10%) of regular FBS or CS-FBS, hCAR-SV23 basal activity increased, whereas in DEHP-treated cells, hCAR-SV23 activity remained similar (regular FBS) or slightly increased (CS-FBS). Subsequent experiments identified a serum-free culture condition to detect DEHP activation of hCAR-SV23. Under this condition, artemisinin, artemether, and arteether increased hCAR-SV23 activity, whereas they decreased it in cells cultured in medium supplemented with 10% regular FBS. By comparison, FBS increased the basal activity of the wild-type isoform of hCAR (hCAR-WT), whereas it did not affect the basal activity of the SV24 splice variant (hCAR-SV24) or ligand activation of hCAR-SV24 and hCAR-WT by 6-(4-chlorophenyl)imidazo[2,1-b][1,3]thiazole-5-carbaldehyde O-(3,4-dichlorobenzyl)oxime (CITCO). The use of serum-free culture condition was suitable for detecting CITCO activation of hCAR-WT and hCAR-SV24. In conclusion, FBS leads to erroneous classification of pharmacological ligands of hCAR-SV23 in cell-based assays, but investigations on functional ligands of hCAR isoforms can be conducted in serum-free culture condition.     

镨三元配合物对HL60细胞生长代谢热动力学的影响

目的观察水杨酸硫代脯氨酸镨三元配合物{［Pr（C7H5O3）2（C4H6NO2S）］•2H2O }对体外培养HL 60细胞生长代谢热动力学的影响。方法应用微量量热法绘制［Pr（C7H5O3）2（C4H6NO2S）］•2H2O作用时HL 60细胞生长代谢产热曲线,解析生长代谢速率常数（κ）、最大热输出功率（Pmax）、达峰时间（tmax）及配合物对细胞生长代谢的抑制率（I） 等热动力学参数,实验72 h应用显微观测法检查细胞凋亡情况。结果不同浓度［Pr（C7H5O3）2（C4H6NO2S）］•2H2O处理HL 60细胞后,细胞生长代谢受到不同程度抑制,并呈浓度依赖性;［Pr（C7H5O3）2（C4H6NO2S）］•2H2O达到4.0 μg•mL－1时,肿瘤细胞κ和Pmax明显减小,I明显增大。结论［Pr（C7H5O3）2（C4H6NO2S）］•2H2O影响HL 60细胞生长代谢,且具有剂量 效应关系,其有效作用浓度为4.0 μg•mL－1。     

羟嘌呤醇对衰竭心肌蛋白氧化和心肌收缩力的长期效果

目的研究黄嘌呤氧化酶（XO）抑制剂——羟嘌呤醇（Oxy）增强缺血后心力衰竭心肌收缩力的长期效果,并初步探讨其作用机制。方技将120只SV120小鼠随机分为心肌梗死（MI）对照组、假手术组和Oxy治疗组。通过结扎冠状动脉左前降支（LAD）建立小鼠缺血后心力衰竭模型。Oxy治疗组口服1mmol／L Oxy。9～11个月后,对三组小鼠进行心脏超声检查;取右心室束状肌分析其心肌兴奋-收缩耦联的变化。应用激光光栅衍射测定肌节长度;应用离子渗透微注射法向样本心肌细胞内注入Fura-2荧光染料,测量心肌细胞质内游离Ca^2＋浓度（[Ca^2＋]．）;通过应用ryanodine和增加刺激频率的方法使心肌达到强直收缩,即心肌纤维与Ca^2＋的相互作用处于稳定状态,分析在稳定状态下心肌收缩力一细胞内钙关系;应用Western blotting测定肌丝蛋白的氧化情况。结果长期口服Oxy能明显改善心力衰竭小鼠的心脏收缩功能,减小室壁厚度;明显改善心肌细胞的兴奋-收缩耦联过程,有效地增强心肌收缩力,显著提高稳态时心肌细胞钙激活的最大收缩力（Fmax）。Western blotting检测显示,与MI对照组心肌肌丝蛋白相比,Oxy治疗组中的肌动蛋白氧化修饰受到明显抑制。结论长期服用Oxy能够有效改善衰竭心肌的工作状态,改善／促进兴奋-收缩耦联过程,增强心肌收缩力。这种长期作用的机制是抑制心肌肌丝中肌动蛋白的氧化修饰,从而增强肌丝对钙的敏感性,增加收缩力。Oxy由于对[Ca^2＋]．的增加较小,能够减轻细胞内Ca^2＋负担及其所带来的负作用,具有更好的临床应用前景。     

Distribution and biomarker of carbon‐14 labeled fullerene C60 ([14C(U)]C60) in pregnant and lactating rats and their offspring after maternal intravenous exposure

A comprehensive distribution study was conducted in pregnant and lactating rats exposed to a suspension of uniformly carbon‐14 labeled C₆₀ ([¹⁴C(U)]C₆₀). Rats were administered [¹⁴C(U)]C₆₀ (~0.2 mg [¹⁴C(U)]C₆₀ kg^–1 body weight) or 5% polyvinylpyrrolidone (PVP)‐saline vehicle via a single tail vein injection. Pregnant rats were injected on gestation day (GD) 11 (terminated with fetuses after either 24 h or 8 days), GD15 (terminated after 24 h or 4 days), or GD18 (terminated after 24 h). Lactating rats were injected on postnatal day 8 and terminated after 24 h, 3 or 11 days. The distribution of radioactivity in pregnant dams was influenced by both the state of pregnancy and time of termination after exposure. The percentage of recovered radioactivity in pregnant and lactating rats was highest in the liver and lungs. Radioactivity was quantitated in over 20 tissues. Radioactivity was found in the placenta and in fetuses of pregnant dams, and in the milk of lactating rats and in pups. Elimination of radioactivity was < 2% in urine and feces at each time point. Radioactivity remained in blood circulation up to 11 days after [¹⁴C(U)]C₆₀ exposure. Biomarkers of inflammation, cardiovascular injury and oxidative stress were measured to study the biological impacts of [¹⁴C(U)]C₆₀ exposure. Oxidative stress was elevated in female pups of exposed dams. Metabolomics analysis of urine showed that [¹⁴C(U)]C₆₀ exposure to pregnant rats impacted the pathways of vitamin B, regulation of lipid and sugar metabolism and aminoacyl‐tRNA biosynthesis. This study demonstrated that [¹⁴C(U)]C₆₀ crosses the placenta at all stages of pregnancy examined, and is transferred to pups via milk. Copyright © 2015 John Wiley & Sons, Ltd.     

睑袋成形术并发泪囊功能不全

目的探讨睑袋成形术导致泪囊功能不全的原因和治疗方法。方法对睑袋成形术后无睑外翻出现溢泪的患者,进行泪道功能检查,功能不全者行下睑睑部眼轮匝肌缩短或断端吻合,下睑眶部眼轮匝肌上移手术。结果28例患者因睑袋成形术后并发泪囊功能不全,再次手术时均发现有过量切除或未能缩紧(或缩紧不足)睑部眼轮匝肌。经手术加强睑部眼轮匝肌张力后,泪囊“泵”功能恢复,溢泪消失。结论睑袋成形术中,对多余及松弛组织去除量的控制不当,或术中未能有效地恢复下睑各层结构张力的平衡,尤其是下睑睑部眼轮匝肌张力明显减弱时,其泪囊的“泵”作用消失,出现功能性溢泪。通过手术恢复下睑轮匝肌张力的“泪泵”功能,有效地治疗了因睑袋成形术所并发的泪囊功能不全。     

耐药逆转剂对耐药细胞内钙离子浓度的影响

目的 :探讨耐药逆转剂对耐药细胞K5 62 A0 2内游离钙离子 ( [Ca2 ]i)浓度的影响。方法 :用Fura 2 AM方法测定耐药细胞株K5 62 A0 2及其敏感株K5 62的静息 [Ca2 ]i水平 ,并观察耐药调节剂汉防己甲素 (Tet)、屈洛昔芬 (Drol)单独或联合应用后细胞内 [Ca2 ]i浓度的变化。结果 :静息状态下K5 62 A0 2细胞的 [Ca2 ]i浓度显著高于K5 62细胞。 1μmol·L- 1 Tet或 5 μmol·L- 1 Drol单独作用于K5 62 A0 2细胞引起 [Ca2 ]i浓度的明显升高 ,两者联合应用有拮抗作用。结论 :K5 62 A0 2细胞内 [Ca2 ]i浓度的增高可能是导致其耐药的原因之一 ,但耐药调节剂Tet、Drol对耐药细胞 [Ca2 ]i的影响在其逆转耐药中的作用有待进一步研究     

Arsenic trioxide induces cardiac fibroblast apoptosis in vitro and in vivo by up-regulating TGF-β1 expression

Arsenic trioxide (As₂O₃; ATO) is clinically effective in treating acute promyelocytic leukemia (APL); however, it frequently causes cardiotoxic effects. This study was designed to investigate whether ATO could induce apoptosis of cardiac fibroblasts (CFs) that play very important roles in maintaining the structure integrity and function of the heart. Cardiac fibroblasts from guinea pigs administered with ATO (1 mg/kg bw) were used to test the pro-apoptotic role of ATO in vivo. The current study demonstrated that ATO induced morphological characteristics of apoptosis and Caspase-3 activation in CFs of guinea pigs along with a significant up-regulation in TGF-β1 protein expression, Bax/Bcl-2 ratio and ERK1/2 phosphorylation. In vitro MTT assay showed that ATO remarkably reduced the viability of cultured cardiac fibroblasts (NRCFs) from neonatal rat in a concentration- and time-dependent manner. Consistent with the notions in vivo, ATO significantly induced the apoptosis in NRCFs, dramatically up-regulated TGF-β1 protein level and Bax/Bcl-2 ratio in a time-dependent fashion and activated Caspase-3 and ERK1/2. Finally, pretreatment with LY364947, an inhibitor of TGF-β signaling could apparently reverse these changes. We therefore conclude that TGF-β is functionally linked to ERK1/2 and that TGF-β signaling is responsible for ATO-induced CFs apoptosis, which provides a novel mechanism of ATO related cardiac toxicology.     

Müller glia: Stem cells for generation and regeneration of retinal neurons in teleost fish

Adult zebrafish generate new neurons in the brain and retina throughout life. Growth-related neurogenesis allows a vigorous regenerative response to damage, and fish can regenerate retinal neurons, including photoreceptors, and restore functional vision following photic, chemical, or mechanical destruction of the retina. Müller glial cells in fish function as radial-glial-like neural stem cells. During adult growth, Müller glial nuclei undergo sporadic, asymmetric, self-renewing mitotic divisions in the inner nuclear layer to generate a rod progenitor that migrates along the radial fiber of the Müller glia into the outer nuclear layer, proliferates, and differentiates exclusively into rod photoreceptors. When retinal neurons are destroyed, Müller glia in the immediate vicinity of the damage partially and transiently dedifferentiate, re-express retinal progenitor and stem cell markers, re-enter the cell cycle, undergo interkinetic nuclear migration (characteristic of neuroepithelial cells), and divide once in an asymmetric, self-renewing division to generate a retinal progenitor. This daughter cell proliferates rapidly to form a compact neurogenic cluster surrounding the Müller glia; these multipotent retinal progenitors then migrate along the radial fiber to the appropriate lamina to replace missing retinal neurons. Some aspects of the injury-response in fish Müller glia resemble gliosis as observed in mammals, and mammalian Müller glia exhibit some neurogenic properties, indicative of a latent ability to regenerate retinal neurons. Understanding the specific properties of fish Müller glia that facilitate their robust capacity to generate retinal neurons will inform and inspire new clinical approaches for treating blindness and visual loss with regenerative medicine.