高效液相色普法测定兔灌胃后血清中百草枯浓度及其变化特征

目的 探索建立高效液相色谱法（HPLC）在测定兔血清中百草枯浓度的可行性,并观察不同剂量 百草枯灌胃后兔血清浓度的经时变化情况。方法 12 只家兔按照随机数字表法分为两组,每组6 只,分别灌胃 给予100 mg/kg（高剂量组）和20 mg/kg（低剂量组）百草枯,于给药后1、2、5、12、24、48 及72 h 采集血 清,血清用乙腈直接沉淀蛋白处理后进行高效液相测定。色谱柱条件：流动相为0.1 mol/L 磷酸缓冲液（含 12.5 mmol/L 庚烷磺酸钠）- 乙腈（90 ︰ 10,TFA 调pH=2.8）,流速为1.0 ml/min,检测波长为258 nm,柱温为 30℃。结果 所建立的方法在0.2 ～ 100.0 mg/L 浓度范围内线性关系良好（r =0.999）。相对回收率在97.82% ～ 101.20% 之间,绝对回收率在84.37% ～ 88.80% 之间,日内和日间精密度（RSD）<5%。百草枯血药浓度时间 曲线为单峰,无论是高剂量组还是低剂量组,给药2 h 后其血清浓度达到峰值,之后逐渐下降,其中,高剂量组于 给药后72 h 后检测不出百草枯,低剂量组于药后24 h 检测不出百草枯。重复测量设计的方差分析结果显示, 不同时间点间、不同剂量组间的百草枯浓度及高、低剂量组随时间变化趋势差异有统计学意义。结论 所建 立的HPLC 方法可用于测定兔血清百草枯浓度,不同剂量百草枯兔灌胃后其血清浓度和蓄积的时间与剂量有 关,给药2 h 后血药浓度达峰值。     

A newly established murine immature dendritic cell line can be differentiated into a mature state, but exerts tolerogenic function upon maturation in the presence of glucocorticoid

The phenotype and function of murine dendritic cells (DCs) are primarily studied using bone-marrow-derived DCs (BM-DCs), but may be hampered by the heterogeneous phenotype of BM-DCs due to their differential state of maturation. Here we characterize a newly established murine DC line (SP37A3) of myeloid origin. During maintainance in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF) and M-CSF, SP37A3 cells resemble immature DCs characterized by low expression of major histocompatibility complex (MHC) II and costimulatory molecules and low T-cell stimulatory capacity. Upon stimulation, SP37A3 cells acquire a mature phenotype and activate naive T cells as potently as BM-DCs. Similar to BM-DCs, SP37A3 cells activated in the presence of dexamethasone-induced regulatory T cells, which were anergic upon restimulation and suppressed proliferation of naive T cells. This tolerogenic state was reflected by lower expression levels of costimulatory molecules and proinflammatory cytokines compared with mature cells, as well as up-regulated expression of FcgammaRIIB and interleukin-1RA (IL-1RA). SP37A3 cells were responsive to dexamethasone even when applied at later time points during activation, suggesting functional plasticity. Thus, DC line SP37A3 represents a suitable model to study functions of immature and mature as well as tolerogenic myeloid DCs, circumventing restrictions associated with the use of primary DCs and BM-DCs.     

虹膜识别技术在准分子激光原位角膜磨镶术治疗近视性散光中的临床研究

目的评价虹膜识别技术应用于准分子激光原位角膜磨镶术（LASIK）治疗近视性散光的准确性、稳定性及可预测性。方法采用虹膜识别引导的LASIK治疗近视散光患者97例（183只眼）,按术前柱镜度数分为3组：1组（-0．50～-1．00D）79只眼,2组（-1．25～-2．00D）70只眼,3组（-2．25～4．00D）34只眼;按术前柱镜轴向分为组A（循规散光）106只眼、组B（逆规散光）43只眼、组C（斜轴散光）34只眼。术前采集散瞳前后的虹膜数据和波阵面像差数据,经过虹膜识别后形成ate文件,将该数据同Orbsesn角膜地形图系统产生的ore文件相结合设计手术方案形成tls文件,导入准分子激光系统,激光器对平卧位时术眼再次进行虹膜识别,确定瞳孔中心偏移量和眼球旋转角度,在治疗时加以补偿,术中三维眼球自动跟踪系统监测眼球运动。观察手术前后不同时期的视力、散光度及轴向变化。结果术中检测出瞳孔中心总体的偏移量为X轴方向（0．41±98．90）μm、Y轴方向（109．15±141．35）μm、眼球旋转偏移角度0．83°±3．40°,术中对其加以补偿。术后6个月裸眼视力≥0．5者183只眼（100．0％）,≥1．0者169只眼（92．3％）,散光度由术前（-1．54±0．65）D减少为术后6个月的（-0．26±0．25）D,对术后各时间点的样本总体散光度进行单因素方差分析,差异有统计学意义（F=5．74,P〈0．01）。各组间两两比较采用SNK检验,术后1周与1、3、6个月比较差异有统计学意义（P〈0．05）;术后1、3、6个月之间差异无统计学意义（P=0．88）。术后6个月顺规散光下降为45只眼（24．6％）,逆规散光下降为31只眼（16．6％）,斜轴散光上升为38只眼（21．0％）,术后6个月有69只眼（37．8％）成为无散光眼。结论虹膜识别引导的LASIK治疗近视散光效果良好,准确性及可预测性较高,是目前精确、先进、有效的散光治疗方法之一。     

复合式小梁切除术中采用角巩膜缘后界1mm结膜切口的疗效观察

目的：观察改良的角巩膜缘后界1mm结膜切口在复合式小梁切除术的临床疗效。

方法：回顾性分析原发性青光眼171例220眼,根据结膜瓣切口不同及缝合方法不同,分为三组,A组采用传统的角巩缘切口33例44眼,B组采用角巩缘后界1mm结膜切口76例94眼,C组采用B组结膜切口基础上连续缝合结膜瓣62例82眼,随访1a。观察术后眼压、滤过泡、前房深度、结膜切口有无渗漏,并进行组间比较三组的临床效果。

结果：术后切口漏水、浅前房发生A组>B组>C组,具有统计学意义(P<0.05),手术成功率94.5%,术后眼压控制和滤过泡形态无明显区别。

结论：角巩膜缘后界1mm结膜切口制作结膜瓣,同时采用结膜切口连续缝合,愈合快,发生结膜切口漏水明显减少,显著能提高复合式小梁切除术的成功率。     

川射干总异黄酮苷元有效部位的制备工艺研究

目的:研究川射干总异黄酮苷元有效部位的工艺条件。方法:正交试验确定大孔吸附树脂吸附总异黄酮吸附条件,乙醇水溶液梯度洗脱以分离苷与苷元,酸水解苷及大孔吸附树脂除酸。结果:总异黄酮苷元的含量在59%～63%之间;得率为3.59%。结论:该工艺简便、合理、可行,具工业化生产价值。     

The Effect of Initial Patient Experiences and Life Stressors on Predicting Lost to Follow-Up in Patients New to an HIV Clinic

AIDS and Behavior - We conducted a prospective cohort study of 450 patients new to an HIV clinic in Houston, TX, to examine the roles of life stressors and initial care experiences in predicting...     

Involvement of lysosomal cathepsins in the cleavage of DNA topoisomerase I during necrotic cell death

OBJECTIVE: Autoantibodies to DNA topoisomerase I (topo I) are associated with diffuse systemic sclerosis (SSc), appear to be antigen driven, and may be triggered by cryptic epitopes exposed during in vivo topo I fragmentation. These autoantibodies recognize topo I and fragments of this autoantigen generated during apoptosis and necrosis. We undertook this study to determine whether lysosomal cathepsins are involved in topo I fragmentation during necrosis. METHODS: Topo I cleavage during necrosis was assessed by immunoblotting of lysates from L929 fibroblasts exposed to tumor necrosis factor alpha (TNFalpha) and the broad caspase inhibitor Z-VAD-FMK, and by immunoblotting of lysates from endothelial cells treated with HgCl2. Purified topo I and L929 nuclei were incubated with cathepsins B, D, G, H, and L, and topo I cleavage was detected by immunoblotting. The intracellular localization of cathepsin L activity and topo I in necrotic cells was examined using fluorescence microscopy. RESULTS: Treatment of L929 cells with TNFalpha and Z-VAD-FMK induced caspase-independent cell death with necrotic morphology. This cell death involved topo I cleavage into fragments of approximately 70 kd and 45 kd. This cleavage profile was reproduced in vitro by cathepsins L and H and was inhibited by the cathepsin L inhibitor Z-FY-CHO. During necrosis, cathepsin L activity diffused from lysosomes into the cytoplasm and nucleus, whereas topo I partially relocalized to the cytoplasm. Z-FY-CHO delayed necrosis and partially blocked topo I cleavage. The topo I cleavage fragments were also detected in necrotic endothelial cells and recognized by SSc sera containing anti-topo I antibodies. CONCLUSION: These results implicate cathepsins, particularly cathepsin L, in the cleavage of topo I during necrosis. This cleavage may generate potentially immunogenic fragments that could trigger anti-topo I immune responses in SSc.