溃结Ⅰ号的制备与稳定性考察

目的提高医院临时处方溃结Ⅰ号保留灌肠剂的稳定性,并对其中的主要成分含量进行控制。方法制备时加入助悬剂,用沉降容积比和再分散性选择适宜的助悬剂及其最佳助悬浓度,并用紫外分光光度法对主要成分柳氮磺吡啶的含量进行测定。结果在制剂中加入卡波母作为助悬剂0.15%就可以达到良好的助悬效果,而且制备的制剂再分散性好。结论加入卡波母作为助悬剂制备的制剂稳定,再分散性好,便于使用和保存。     

丹酚酸A对大鼠半乳糖性白内障形成的抑制作用

业已证明,丹酚酸A有较强的抗氧化和清除自由基等多方面的作用。本实验用大鼠半乳糖性白内障模型,研究局部应用丹酚酸A对白内障形成的影响。结果表明,局部用0.05%的丹酚酸A(每日滴眼两次)对白内障的形成有一定的抑制作用,使白内障形成过程减缓。而且给药组动物晶体内过氧化氢和脂质过氧化产物(MDA)含量减少,蛋白巯基和总巯基增加。体外实验表明,丹酚酸A对醛糖还原酶有一定抑制作用。以上结果提示,丹酚酸A可通过不同途径抑制白内障的形成,对糖性白内障的防治有一定意义。     

Inflammatory bowel disease and predisposition to osteopenia

The prevalence of osteopenia in children with inflammatory bowel disease (IBD) is unknown. The effect of nutritional state, disease activity, and steroid therapy on bone mineral content (BMC) of whole body, lumbar spine, and left femoral neck measured by dual energy x ray absorptiometry in 32 children with IBD was assessed by comparison with 58 healthy local school children. Using the control data, a predicted BMC was calculated taking into account bone area, age, height, weight, and pubertal stage. The measured BMC in children with IBD was expressed as a percentage of this predicted value (% BMC). Mean (SD) % BMC was significantly reduced for the whole body and left femoral neck in the children with IBD (97.0 (4.5)% and 93.1 (12.0)% respectively, p < 0.05). Of the children with IBD, 41% had a % BMC less than 1 SD below the mean for the whole body and 47% at the femoral neck. Reduction in % BMC was associated with steroid usage but not with the magnitude of steroid dose, disease activity, or biochemical markers of bone metabolism. In conclusion, osteopenia is relatively common in childhood IBD and may be partly related to the previous use of steroids.     

催产素对妊娠末期大鼠蜕膜细胞内游离钙的刺激作用

妊娠末期催产素刺激子宫蜕膜细胞产生与分娩有关的前列腺素,但其作用方式仍未知。本实验分离妊娠19d大鼠蜕膜细胞,测定了催产素作用后蜕膜细胞内游离钙的变化,结果加入0.001～1μmol·L^-1催产素后,蜕膜细胞内[Ca²⁺]i出现瞬息增加,其峰值与催产素浓度呈剂量依赖关系,且此作用有自身钝化现象。说明催产素可能激活妊娠末期大鼠蜕膜细胞内的肌醇磷酯蛋白激酶C系统。给妊娠末期大鼠ip硫酸去氢表雄酮钠盐后分离的蜕膜细胞,催产素作用引起[Ca²⁺]i瞬息增加峰值较对照升高。     

Digital beam attenuator technique for compensated chest radiography

The feasibility of producing patient-specific beam attenuators for chest radiography has been investigated using an anthropomorphic phantom and a human volunteer. A low-dose test exposure is digitized, processed, and used to print a small cerium filter, which is placed in the x-ray beam near the collimator. The final radiograph is recorded on film. The technique results in relatively uniform film exposure, so that structures in all regions of the chest are simultaneously displayed with optimal film contrast. The equalized exposure improves image quality in the normally underpenetrated regions and reduces the role of cross-scatter from the lungs. The image is analogous to optical or computer-processed unsharp masking techniques, but the processing is accomplished in the x-ray beam and results in an improved exposure distribution, giving advantages that cannot be achieved with image processing techniques alone.     

Liver metastases: detection by phase-contrast MR imaging

Forty patients with biopsy-proved metastatic liver cancers were studied by magnetic resonance (MR) imaging using one or more conventional (in-phase) pulse sequences and a corresponding phase-contrast (opposed-phase) pulse sequence. Pulse-sequence performance was quantitated by measuring signal-difference-to-noise (SD/N) ratios between cancerous tissue and liver. The SD/N performance of T2-weighted spin-echo (SE) pulse sequences improved when used with the phase-contrast technique. SE 2,000/30 opposed-phase images showed improved (P less than .001) SD/N in 72% of patients over in-phase images. The SD/N of T1-weighted SE or inversion recovery pulse sequences deteriorated when used with the phase-contrast technique. Changes in measured SD/N correlated well with image appearance and actual lesion detectability in individual cases. Phase-contrast imaging should be employed routinely when T2-weighted SE pulse sequences are relied on to detect liver cancer.     

Osteosarcoma: use of MR imaging and MR spectroscopy in clinical decision making

Magnetic resonance (MR) imaging was performed on 14 patients with histologically proved osteosarcoma (mean age, 14.4 years). There was excellent correlation of intramedullary tumor extent as determined with MR imaging and pathologic examination (r = 99%). This was facilitated by the presence of a chemical shift artifact at the tumor-marrow interface on the T1-weighted images. The correlation between CT and pathologic findings was not as good (r = 84%). In a single patient, however, a 10-cm length of sclerotic bone was incorrectly interpreted as being tumor. If this case is excluded, the correlation between CT and pathologic findings improves significantly (r = 96%). T2-weighted images were optimal in demonstrating soft-tissue bulk and breach of the epiphysis or cortex. Vascular involvement was also readily defined. The T2 value of the tumor soft-tissue component decreased in patients who were deemed to have responded well to therapy. Two patients with very high T2 values after chemotherapy developed wide-spread metastatic disease and died. Phosphorus-31 MR spectroscopy of five patients with osteosarcoma showed elevated levels of phosphomonoesters (PMEs), inorganic phosphate (Pi), and phosphodiesters (PDEs). PME and PDE peak areas decreased in three patients after chemotherapy, while Pi peak areas increased.     

Superparamagnetic iron oxide-enhanced MR imaging: pulse sequence optimization for detection of liver cancer

The effects of magnetic resonance (MR) pulse sequences and timing parameters on tumor-liver contrast were studied in an animal model of metastatic liver cancer. Six spin-echo (SE), three inversion-recovery (IR), and four gradient-echo (GRE) sequences were evaluated at 0.6 T before and after injection of super-paramagnetic iron oxide. GRE techniques, irrespective of echo time and flip angle, showed the greatest change in signal intensity (enhancement) of the liver after administration of iron oxide. Single-acquisition GRE sequences (16 seconds) matched the contrast-to-noise ratio (C/N) performance of the most effective 6.4-minute SE sequences. Multiexcitation GRE sequences showed tumor-liver C/Ns per unit time that were significantly (P less than .05) higher than those achieved with SE and IR sequences. GRE sequences, which recruit intravoxel dephasing as an additional source of transverse relaxation enhancement (T2*), show a higher C/N per unit time and in this respect seem superior to SE and IR sequences for MR imaging with superparamagnetic iron oxide.     

中药癌痛克对人肝癌细胞HepG2增殖、凋亡及Rb基因表达的影响

目的:通过观察不同浓度癌痛克对肝癌细胞株HepG2增殖及凋亡的作用,以及在相应状态下细胞内Rb基因表达量的改变,探讨中药癌痛克抗肝癌的可能作用机制。方法:实验于2005-09/2006-03在广州医学院中心实验室完成。取对数生长期的HepG2细胞,使细胞静止于G0/G1期。随机分为癌痛克2,10,50mg/L组和对照组,癌痛克2,10,50mg/L组分别加入对应浓度癌痛克(购自河南省肿瘤研究所,由金蝎、土元、九香虫、大黄、人参、灵芝、黄芪等纯中药组成的粉状制剂,功能:消癌肿、消癌痛、消积水、升白排毒),对照组不加药物,每组设4个复孔。MTT法检测各组细胞24,48,72h增殖率,细胞增殖率=[(A570癌痛克组-A570对照组)/A570对照组]×100%;以流式细胞术检测各组细胞24,48,72h凋亡率;RT-PCR方法检测各组细胞24,48,72h细胞内Rb基因mRNA表达量。结果:①2～50mg/L癌痛克具有明显的增殖抑制作用,癌痛克2,10,50mg/L组在24,48,72h与对照组比较,差异有显著性意义(P<0.05);3组各时点两两之间比较差异有显著性意义(P<0.05);同组各时点之间比较差异有显著性意义(P<0.05)。②2～50mg/L癌痛克组可诱导HepG2细胞凋亡,相同作用时间癌痛克2,10,50mg/L组与对照组比较差异有显著性意义(P<0.001);同一时点各组比较差异有显著性意义(P<0.05);同组不同作用时间点比较差异有显著性意义(P<0.001)。③2～50mg/L癌痛克可上调Rb基因的表达,各浓度组在各时点与对照组比较,差异均有显著性意义(P<0.05);24,48,72h癌痛克2,10,50mg/L组之间比较差异无显著性意义(P>0.05);3组各时点比较差异有显著性意义(P<0.05)。结论:中药癌痛克可通过抑制HepG2细胞增殖或诱导其凋亡,而发挥抗肝癌作用;且其诱导细胞凋亡的机制之一可能为通过增加Rb基因的表达而实现。     

中频交变磁场照射后小鼠的行为学变化

目的:目前电磁辐射对生物体行为学方面的研究还很薄弱,设立不同磁场的强度和不同照射的周期,观察中频领域磁场照射对小鼠的自主活动和学习记忆的影响。方法:实验于2007-05-10/06-15在清华大学医学院和中国医学科学院药用植物研究所完成。①实验材料:磁场发生装置:中频交变磁场发生装置由清华大学工程物理系医学物理与工程研究所自主研发,可产生频率为40kHz,场强为28.8A/m,28.8kA/m的中频交变磁场。自主活动测试箱:中国医学科学院药用植物研究所提供,为一可封闭的金属箱,内置摄像头。4只黑色塑料测试桶分别置于箱子四角。水迷宫测试箱:中国医学科学院药用植物研究所提供。②实验动物及方法:将80只小鼠随机分为不同场强照射组和对照组。强磁场照射1组:11.6kA/m/40kHz,1h/d,连续照射7d。强磁场照射2组:11.6kA/m/40kHz,2h/d,连续照射7d。强磁场照射3组:11.6kA/m/40kHz,2h/d连续照射15d。弱磁场照射组:28.8kA/m/40kHz,2h/d,连续照射7d。对照组除了未放入磁场照射,其他条件与照射组一致。实验过程中对动物处置符合动物伦理学要求。③实验评估:观察其一般活动的改变,并采用自主活动测试箱和水迷宫测试箱进行测试,观察各组小鼠的自主活动和学习记忆的改变。结果:①一般行为观察:与对照组小鼠对比,经过中频交变磁场照射过的各组小鼠活跃度减低,毛色较差。强磁场照射3组(145G,2h/d,连续15d)于第11天和13天分别死亡1只。②自主活动检测结果:强磁场照射2,3组小鼠的运动路程、运动速度、运动时间明显低于对照组(P<0.05)。③水迷宫测试结果:在学习记忆检测阶段撤掉平台,发现各组动物2min内穿越平台原来所在象限的次数没有明显差别(P>0.05)。结论:中频交变磁场照射会给小鼠的自发活动造成一定影响,对学习记忆没有影响。