Iron, ferritin and proteins of the methionine-centered redox cycle in young and old rat hearts

Progressive oxidation of cellular components constitutes a major mechanism of the aging process. An emerging paradigm of redox signaling suggests that low level oxidants activate protective pathways resulting in prolonged cell survival. This report centers on the study of cardiac muscle in young and old rats, including (i) the expression of ferritin (Ft) the major iron storage protein, and (ii) the expression of the major proteins of the methionine-centered redox cycle (MCRC), which controls the cellular methionine redox status. Total amounts of Ft (protein) and its mRNA encoding for Ft L-subunit (Ft-L) were higher in the aged hearts, indicating that the iron-binding capacity of myocardial Ft increased with age. Among the proteins of the MCRC, methionine sulfoxide reductases A and B (MsrA, MsrB) and MsrA mRNA were significantly higher in hearts of old rats with a significant decrease in MsrA activity. The observed up-regulation of the expression of Msr and Ft-L could represent a protective response to the increased oxidative stress in the aging myocardium.     

含环己烯氮杂环结构的聚醚砜酮三元共聚物合成

用1－甲基－4，5－二（4－氯代苯甲酰基）环己烯与4－（4－羟基苯基）－2，3－二氮杂萘－1－酮、4，4′－二氯二苯砜经亲核共缩聚反应，合成了含环己烯结构的杂环联苯型聚醚砜酮三元共聚物。结果表明，聚合物是一种具有较高的玻璃化转变温度的可溶性无规共聚物。聚合物含有不饱和双键结构，有一种反应性高分子。     

Degradation of VX and sulfur mustard by enzymatic haloperoxidation

Chloroperoxidase (CPO) isolated from Caldariomyces fumago (20 U ml(-1)) together with urea hydrogenperoxide (UPER, 0.5 mM) and sodium chloride as co-substrate (NaCl, 0.5 M) caused rapid breakdown of VX (10 microM) (t((1/2)) = 8 s, 25 C, 50 mM tartarate, pH 2.75). Glucose oxidase (GOX, Aspergillus niger) and glucose were used as an alternative source for H(2)O(2). A mixture of GOX (20 U ml(-1)), glucose (GLU 0.45 M), CPO (20 U ml(-1)) and NaCl (0.5 M) caused a 3.8-fold slower degradation of VX (10 microM) (t((1/2)) = 30 s, 25 C, 50 mM tartarate, pH 2.75). The concentrations of H(2)O(2) and chlorine produced by this enzyme/substrate mixture depended mainly on the GLU concentration. Horseradish peroxidase (HRP) together with UPER (1 mM) and sodium iodide (NaI, 0.05 M) caused progressive degradation of VX that was more than 400-fold slower than with CPO (20 U ml(-1)), UPER (0.5 mM) and NaCl (0.5 M) (t((1/2)) = 55 min, 25 C, pH 8). Skin decontamination of VX by CPO was tested in pig-ear skin in vitro. The chemical agent VX (0.01 M, 100 microl) was degraded by 98% within 3 h of skin diffusion when a mixture of UPER/NaCl/CPO was applied 60 min prior to VX application. A mixture of UPER/NaCl without CPO also caused significant VX degradation (94%) during skin diffusion whereas it did not cause any VX degradation in solution. Degradation of VX in skin, obtained without exogenous CPO, may indicate involvement of endogenous intradermal haloperoxidase-like enzyme. Reagent UPER (1 mM) did not cause any degradation of VX in solution or during its skin diffusion. Furthermore, a mixture of CPO, UPER and NaCl caused rapid degradation of sulfur mustard (HD). Sulfur mustard (50 microM) incubated in the presence of CPO (4 U ml(-1)), UPER (0.05 M) and NaCl (0.5 M) at pH 2.75 and 30 C was oxidized by 97% and 99% within 5 and 10 min, respectively. The oxidation products HD sulfoxide, HD sulfone and HD sulfoxidevinyl were identified by GC/MS in the enzymatic chloroperoxidation mixture.     

Sulindac derivative- induced apoptosis in a human umbilical vein endothelial cell line ECV304

Objective To investigate the effects of sulindac metabolites on proliferation and apoptosis in the human umbilical vein endothelial cell line ECV304 in vitro.Methods The proliferation profile of ECV304 was determined by methyl thiazolyl tetrazolium (MTT) method. Cell cycle distribution, apoptosis and the ultrastructure of ECV304 were detected by flow cytometry (FCM) and electron microscopy, respectively.Results MTT assay showed that the sulfide inhibited the proliferation of ECV304 and its effect was dose- dependent; the IC50 was 200 μmol/L. FCM showed that the sulfide changed cell cycle distribution. The cell cycle distribution was as follows: G1 phase (control group 77. 74%±1. 58%; sulfone group 75. 63%±2. 12%; sulfide group 46. 12%±1. 60%); S phase (control group 13. 64%±1. 22%; sulfone group 16. 40±2. 30%; sulfide group 27. 26%±2. 08%); G2- M phase (control group 8. 61%±0. 67%; sulfone group 7. 98%±0. 49%; sulfide group 26. 62%±3. 54%). The apoptosis rates in the control group, sulfone group and sulfide group were 6. 08%±3. 39%, 4. 81%±2. 14% and 51. 90%±5. 67%, respectively. Sulfide reduced the proportion of G1 phase, increased the proportion of S phase, G2- M phase and the apoptosis rate significantly (P<0. 01, vs control). In the sulfide- treated cells, there were nuclear fragmentation and chromosomal condensation, shrinkage of the cell and loss of contact with neighboring cells. Apoptotic bodies were observed. Sulfone showed no effect on cell proliferation, cell cycle distribution or cell morphology.Conclusions Sulfide can significantly reduce the proliferation of ECV304, change the cell cycle distribution and arrest cells in G2- M phase where apoptosis may be induced. Sulfone has no such effects on this cell line.     

Structure and Properties of Poly(butyl acrylate‐block‐sulfone‐block‐butyl acrylate) Triblock Copolymers Prepared by ATRP

Summary: A series of telechelic OH polysulfones (PSU) were converted to atom transfer radical polymerization (ATRP) macroinitiators by reaction with 2‐bromoisobutyryl bromide. Three macroinitiators with different chain lengths were extended with poly(butyl acrylate) (PBA) to form ABA triblock copolymers. The structure and dynamics of the ABA triblock copolymers with PSU central segments and various molecular weight PBA side chains were investigated by small‐angle X‐ray scattering and rheology. The block copolymers form micelles with a PSU core and PBA corona. The length of each block has an important effect on the structure and resulting dynamics of the copolymers. Dynamic mechanical measurements indicate three relaxation modes: (i) PBA segmental relaxation at high frequency; (ii) PBA relaxation of the corona block at intermediate frequency; (iii) an additional relaxation process related to structural rearrangement of the micelles at low frequency. The shear modulus plateau corresponding to a soft rubbery state extends over a very broad time or temperature range because of this slow additional relaxation.

Schematic illustration of the structural elements and the bulk supramolecular structure for a symmetric triblock copolymer with a stiff central segment strongly incompatible with the other constituent.     

Effect of diaminodiphenyl sulfone on circadian rhythms of hematological parameters in mice

The study explores the effect of diaminodiphenyl sulfone administered at different times of the day in fall and spring on the diurnal rhythms of hemoglobin level and erythrocyte and leukocyte counts in CBA mice. Changes in the rhythmic patterns of these parameters depend on the season and the time of treatment. Translated fromByulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 123, No. 4, pp. 455–459, April, 1997     

多孔聚醚砜平板膜培养肝细胞的初步研究

目的初步观察一种多孔聚醚砜平板膜上支持人肝细胞系L02细胞生长能力,探讨聚醚砜膜材料用于生物人工肝的可行性。方法将正常人肝细胞系L02细胞接种在多孔聚醚砜平板膜片上,用倒置相差显微镜、激光共聚焦显微镜以及扫描电镜观察L02细胞在此种平板膜上的贴壁和生长情况。结果倒置相差显微镜下可以观察到L02细胞能够在多孔聚醚砜平板膜较好生长,细胞培养到7 d时,细胞仍然保持良好生长增殖状态。激光共聚焦显微镜证实了该结果,且随着培养时间延长,细胞可呈多细胞聚集状态生长,保持活性。扫描电镜下膜表面微孔和微小孔结构得以观察,并能观察到部分细胞可以向微孔中延伸密集生长。结论多孔聚醚砜平板膜能够有效的支持L02细胞在其表面生长,有望成为生物人工肝支持系统理想的生物支架材料。     

HPLC法测定模拟乙烯砜型染料-纤维化合物的碱性水解速度常数

提出了采用高效液相色谱技术分离模拟乙烯砜型染料-纤维化合物及其碱性水解产物的方法。采用ODS硅胶柱,以100%甲醇作流动相,分离效果好,无其它干扰,最小检测量为1×10~(-9)g。本文测定了五种不同结构的模拟乙烯砜染料-纤维化合物的碱性水解速度常数。     

含六氟异丙烷结构的聚芳醚酮和聚芳醚砜的合成与性能

以双酚AF和4,4-二氟二苯酮、4,4-二氯二苯砜为单体采用亲核取代反应,通过缩聚法合成了新型含氟聚芳醚酮(PAEK-AF)和含氟聚芳醚砜(PAES-AF)。凭借FT-IR、GPC、DSC、TGA等分析手段对聚合物的结构和性能进行了表征和研究。结果表明:所合成的PAEK-AF和PAES-AF具有较高的分子量(Mw>2.4×105);良好的耐热性(玻璃化转变温度Tg分别为163、200℃),优异的热稳定性(空气中失重5%的温度分别为515、525℃);1 MHz下的介电常数分别是1.69和1.89;良好的溶解性,室温下能溶解在N甲基吡咯烷酮、二甲基乙酰胺、四氢呋喃、氯仿等有机溶剂中。