Physical laws of cholesterol gallstone fragmentation

Efficient fragmentation is the most important prerequisite for successful treatment of gallstones by extracorporeally induced shock waves. No data are available on the amount of energy necessary for stone disintegration and on the threshold energy below which no further fragmentation occurs. We therefore performed an in vitro investigation on human cholesterol gallstones to elucidate physical laws governing shock-wave lithotripsy. First, the focal pressure of the lithotripter was measured to calculate the energy traversing a stone. Second, 96 gallstones from 16 gall bladders were analysed with respect to physicochemical composition, radiological features and ultrasound before fragmentation was performed. Energy for stone disintegration was constant within each stone family but varied between 4.6 J mL^?1 and 36.8 J mL^?1 in different families. This energy correlated linearly with stone volume. None of the radiological and physicochemical factors revealed a clear-cut correlation of the different energies necessary for similar stone disintegration. The threshold energy differed between 0.26 mJ and 1.04 mJ per pulse. In conclusion, stone volume was the best parameter predicting stone fragmentation. However, in cholesterol stones with a similar composition the required energy per volume varies considerably together with the threshold energy. Radiological and ultrasound parameters appear to be of minor importance in explaining these differences.     

Risk of gallstones following gastrectomy in Japanese men

The risk of gallstones developing after gastrectomy in middle-aged Japanese men was investigated in a study of 2,738 men aged between 48 and 56 years who underwent both gallbladder ultrasonography (US) and a barium study of the upper digestive tract. It was revealed that 61 men had gallstones, 37 had had their gallbladder removed previously, and 55 had a history of gastrectomy. The prevalence of gallstones was 3.5 times higher in the men who had previously undergone gastrectomy (7.7%) than in those who had not (2.2%) (P=0.03). Moreover, gallstones tended to be more prevalent in those who had undergone Billroth II gastrectomy (12.5%) compared with those who had undergone Billroth I gastrectomy (5.6%); however, the difference was not significant. These results indicate that gastrectomy using either Billroth I or Billroth II reconstruction predisposes to gallstone formation. Nevertheless, it was estimated that prior gastrectomy was responsible for no more than 5% of gallstones in the study population.     

实验性视网膜脱离Na十-K+-转运ATP酶活性及RPE超微结构改变

目的：探讨实验性视网膜脱离(retinal detachment，RD)后视网膜色素上皮(retinal pigment epithelium，RPE)对视网膜下液(subretinal fluid，SRF)的输导功能。 方法：将制作成功的实验性单眼RD 28只家兔随机分为4组，每组7只，每只兔的另眼作为对照。分别取RD部位的RPE-脉络膜组织和对照眼相应部位的组织匀浆，再测定ATP水解产物无机磷含量，以判断ATP酶活性；并作实验和对照眼的两种组织相应部位的RP正电镜观察。 结果：实验眼Na^十-K^+_-转运ATP酶活性为(2.16士1.26)/μmol(mg·h)，对照眼为(4.84±1.59)μmol/(mg·h)，二者差异显著(t＝5.52，P<0.01)；酶活性降低程度随病程延长而减轻(p<0.05)。电镜观察实验眼RD后第2至4周有自脉络膜向视网膜方向的吞饮泡，且随病程延长而增多。 结论；RD发生后RPE的外向输导功能增强，随病程进展，此功能减弱而内向输导功能产生。 （中华眼底病杂志，1997，13：83-85）     

氧自由基动态变化与胆红素结石成石的实验研究

用胆红素结石（ｐｓ）兔模型进行实验，设单纯胆道梗阻（ＢＯ）组、梗阻和大肠杆茵感染（ＢＯＩ）组及空白对照组，观察肝组织及胆汁氧自由基（ＯＦＲ）变化情况及对ＰＳ的影响。实验结果：肝组织部分ＯＦＲ、前列腺素Ｅ＿２（ＲＧＥ＿２）及ＰＳ的动态变化趋势相似，三者呈正相关；ＢＯＩ组的上述指标均较ＢＯ组为高。提示ＯＦＲ可能促使ＰＧＥ＿２合成，后者致糖蛋白分泌而参与ＰＳ的形成；大肠杆菌感染可能在梗阻的基础上增多ＯＦＲ的生成而增加了Ｐｓ的形成。     

Altered impedance during pigment aggregation in<Emphasis Type="Italic">Xenopus laevis</Emphasis> melanophores

Melanophores are dark-brown pigment cells located in the skin of amphibia, fish and many invertebrates. The skin colour of these organisms is regulated by the translocation of pigment organelles, and the pigment distribution can be altered by external stimuli. The ability to change colour in response to stimuli makes these cells of interest for biosensing applications. It was investigated whether pigment aggregation in Xenopus laevis melanophores can be detected by impedance measurements performed in transparent microvials. The results show that cell attachment, cell spreading and pigment aggregation all resulted in impedance changes, seen particularly at the highest frequency tested (10 kHz). The mechanisms behind the impedance changes were investigated by the addition of latrunculin or melatonin, both of which cause pigment aggregation. The latrunculin-induced aggregation was associated with cell area decrease and filamentous actin (F-actin) breakdown, processes that can influence the impedance. Lack of F-actin breakdown and an increase in cell area during melatonin-induced aggregation suggest that some other intracellular process also contributes to the impedance decrease seen for melatonin. It was shown that impedance measurements reflect not only cell attachment and cell spreading, but also intracellular events.     

视细胞移植术后视网膜色素上皮的结构变化

获得纯化的由大肠杆菌表达的小鼠 Ｆａｓ配体（Ｆａｓ ｌｉｇａｎｄ,ＦａｓＬ）。方法：以质粒 ｐＥＴ－１５ｂ为载体,在大肠杆菌ＢＬ２１（ＤＥ３）中表达小鼠的ＦａｓＬ,用金属螫合亲和层析法纯化。结果：转化菌中,重组质粒是稳定的,异丙基－β－Ｄ硫代半乳糖苷可诱导小鼠ＦａｓＬ的表达 ,金属螫合亲和层析法可以初步纯化此蛋白。结论：在大肠杆菌中表达出小鼠的ＦａｓＬ,并得到初步纯化。     

槲皮素对培养人视网膜色素上皮细胞增生及DNA合成的影响

目的研究槲皮素(quercetin, QUE)对培养人视网膜色素上皮(retinal pigment epithelium, RPE)细胞增生和DNA合成以及对表皮生长因子(epidermal growth factor, EGF)促RPE细胞增生和DNA合成作用的影响。方法用细胞计数和3H-胸腺嘧啶核苷(3H-thymidine, 3H-TdR)掺入方法,观察不同浓度(200、100、50、1μmol/L)的QUE和最大浓度的QUE(200μmol/L)在不同作用时间（24-168小时）,分别单独或与EGF共同作用时,对RPE细胞增生及DNA合成的影响,排除着色的死细胞,用活细胞计数法判断药物的细胞毒性作用。结果QUE 200μmol/L具有最强的抑制效应,48小时时抑制效应已明显出现,96小时时抑制达到高峰。与QUE单独作用相比,QUE对EGF的促RPE细胞增生效应能产生更强的抑制。QUE无细胞毒性作用,各实验组细胞活力均在85.00%以上。结论QUE以剂量依赖和时间依赖的方式抑制RPE细胞的增生,尤其是由EGF刺激的增生,并且对培养的RPE细胞无细胞毒作用。(中华眼底病杂志,1999,15:27-29)     

天然色素的药理作用研究概况

比较天然色素与合成色素特点，列举几种天然色素及其药理作用。天然色素以其无毒害、广泛的药理作用及诸多优点，而受到日益广泛的重视、研究与应用，天然色素取代合成色素是必然的趋势。     

米团花色素的提取及其稳定性研究

米团花色素是云南省某些地区居民使用的一种传统黄色天然食用色素.本研究表明,米团花色素在433 nm和326 nm处分别有一个较强吸收峰.稳定性实验表明:该色素对酸、热、光、氧化剂过氧化氢(不加热)、常见金属离子、食盐及食糖等稳定,但在碱性条件或亚硫酸钠存在时不太稳定.此外,加入过氧化氢后加热也会引起其吸光值的显著改变.初步确定米团花色素主要为胺类物质.在正常加工条件下,是一种较理想的天然食用色素.     

腔镜肝切除术治疗肝内胆管结石的可行性和微创分析

目的：对腔镜肝切除治疗肝内胆管结石的可行性和微创进行分析，实现对胆结石的治疗。方法：选取本院的24例胆结石患者进行治疗，在腹腔镜下对患者进行胆结石的切除，患者在切除的过程中均无任何不适现象，患者的切除手术均成功完成。结果：24例患者整体上手术均顺利完成，手术中没有出现任何出血现象，患者没有术后并发症。结论：在宫腔镜下对患者肝内胆结石进行切除的效果显著。