Coloration of Silicone Prostheses: Technology versus Clinical Perception. Is There a Difference? Part 2, Clinical Evaluation of a Pilot Study

Purpose: The aim of this investigation was to explore the relationship between an objective computer measurement of color difference (ΔE) and subjective clinical opinion of a “good” color match between silicone samples and skin. Materials and Methods: In Part 1 of this study, silicone samples were colored to match the skin of 19 African‐Canadian subjects based on spectrophotometric measurements and pigment formulae determined by computerized color formulation software. Four iterative samples were prepared for each subject; a ΔE value was recorded for each sample to represent the color difference between the silicone sample and skin. In this article, Part 2, five judges independently assessed the color match of the silicone samples to the skin of each of the subjects. Skin and silicone samples were rated on a five‐point scale as a measure of “color match.” A multivariate analysis was used to determine relationships between judges’ assessments and the following variables: color difference between silicone and skin (ΔE), pigment loading, and skin characteristics (L*, a*, b*). Results: There was a positive correlation between judges’ scores and low ΔE values for the first two samples. All judges rated the first sample a poorer color match than the fourth sample (p < 0.015). The third sample performed better overall according to judges. Increased pigment loading in the fourth sample resulted in poorer scores. A trend was observed in pigment selection based on skin values, though no significant relationships were determined. Conclusion: Spectrophotometry and computerized color formulation technology offer an enhanced understanding of color for its artistic application in facial prosthetic treatment. While some correlation between the objective and subjective assessments of color match exist, it is not a simple relationship. Further study is required to better understand the relationship between technology and clinical perception, specifically in objective and subjective assessments of a “good” color match of silicone to skin.     

Regional differences in mucosal hemodynamics in experimental colonic injury in rats

In rat colon damaged by 10% acetic acid and by dinitrochlorobenzene, we test the following hypotheses: (1) mucosal hemodynamic changes are significantly different at the ulcer base, the ulcer margin, and the inflamed non-ulcer-bearing mucosa; and (2) these mucosal hemodynamic changes also vary with time after induction of the colonic injury. Mucosal hemodynamic changes were documented by reflectance spectrophotometry, and variations in gross mucosal morphology were confirmed by hematoxylin and eosin histologic sections. Results revealed that in the acute stage, the ulcer base, which was covered by necrotic debris, showed ischemia without congestion. The ulcer margin at the edge of the ulcer base showed ischemia with congestion. The nonulcerated mucosa, which appeared erythematous, showed increased perfusion. In the convalescent stage, all the altered perfusion patterns returned to normal. These observations offer plausible explanations for the variability in colonic perfusion observed in experimentally damaged colons.     

基于分光光度法测定血液中非那西丁与扑热息痛含量的肝脏储备功能评估

目的建立基于分光光度法测定非那西丁与扑热息痛含量的肝脏储备功能评估方法。方法筛选分光光度测定的显色体系,确定最大吸收波长,分析不同因素对显色体系的影响,优化非那西丁与扑热息痛水解的最佳条件,最后对技术体系进行应用性验证。结果建立了利用分光光度测定样品中非那西丁和扑热息痛含量的技术体系,即样品加入3 mol/L盐酸水解30 min,加入0.02%1,2-萘醌-4-磺酸钠、1%十六烷基三甲基溴化铵及2%Na OH(或3%Na2CO3)(比例为1∶6∶1∶2或3),分别于500 nm和570 nm下测定吸光值,计算各自浓度。该技术测定血浆样品中非那西丁与扑热息痛时的分辨率和重复性与高效液相色谱法相当。结论利用分光光度技术测定血液中非那西丁与扑热息痛含量,二者比值具有评估肝脏储备功能价值。     

Somatostatin reduces gastric mucosal blood flow in patients with portal hypertensive gastropathy

Agents which decrease gastric mucosal blood flow (GMBF) are postulated to have beneficial effects in arresting gastrointestinal bleeding in cirrhotic patients with portal hypertension. Our objective was to test the hypothesis that in a dose that significantly lowers wedged hepatic venous pressure (WHVP), a bolus injection of somatostatin will significantly decrease GMBF in patients with portal hypertensive gastropathy (PHG). In this placebo-controlled, double-blind, crossover study, 20 cirrhotic patients with PHG were randomly assigned to receive either somatostatin followed by placebo (Group A) or placebo followed by somatostatin (Group B). Wedged hepatic venous pressure was monitored. GMBF in the antrum and corpus was assessed by reflectance spectrophotometry. Indices of hemoglobin concentration (IHb) and indices of oxygen content (ISO₂) were recorded. Nine patients were assigned to Group A, and 11 to Group B. Mild PHG was seen in 16 patients, and severe PHG in 4 patients. Baseline WHVP, IHb, and ISO₂ were similar in both treatment groups. Wedged hepatic venous pressure (WHVP) was significantly lowered [median, 17.6%; interquartile range (–27.0, –12.6%); P=0.0008] after a 250-µg bolus injection of somatostatin. This dose of somatostatin significantly reduced IHb both in the antrum [–10.2% (–23.4, 0.4%)] and in the corpus [–5.8% (–16.6, 5.6%)] compared to placebo (P=0.02 and 0.04, respectively). Intravenous bolus injection of 250 µg somatostatin significantly reduces WHVP and GMBF in patients with PHG. Whether this ability to decrease the GMBF in PHG makes somatostatin an effective treatment in acute gastrointestinal bleeding in PHG deserves to be studied.     

氯硝柳胺测定方法研究进展

利用氯硝柳胺的理化特性,可采取多种不同方法对其进行定性或定量测定。但不同方法的精密度和准确度不同,可根据应用需求进行选择。本文主要对氯硝柳胺的生物测定法、滴定法、紫外-可见分光光度法、色谱法和电化学分析法进行综述。     

紫外分光光度法测定痛风宁微丸中柚皮苷的含量

目的建立痛风宁微丸中柚皮苷的含量测定方法。方法采用紫外分光光度法测定痛风宁微丸中柚皮苷的含量。以甲醇作空白对照,检测波长415 nm。结果柚皮苷量在0.056~0.196 mg范围内与吸收度呈良好的线性关系,r=0.999 8,平均回收率为99.31%,RSD为0.65%。结论本方法简便可行、结果准确可靠、重复性好,可作为痛风宁微丸柚皮苷的含量测定方法。     

紫外光谱法鉴别厚朴及其伪品救必应

目的 建立厚朴及其伪品救必应的紫外光谱鉴别方法。方法 采用中药鉴别紫外谱线组法进行实验。结果 厚朴及其伪品救必的紫外谱线图像、最大吸收峰数目及峰位值具有明显差异。结论 本法简便、准确、灵敏，可用于鉴别厚朴及伪品救必应。     

紫外分光光度法测定左氧氟沙星滴耳液中左氧氟沙星的含量

目的建立左氧氟沙星滴耳液中左氧氟沙星的含量测定。方法紫外分光光度法。溶剂为0.1 mol.L-1盐酸溶液,检测波长293 nm。结果左氧氟沙星在2~8 mg.L-1范围内,线性关系良好,r=0.9995。回收率为99.6%。结论该法可准确测定左氧氟沙星滴耳液中左氧氟沙星的含量,适用于制剂的质量控制。     

紫外分光光度法对苯扎溴铵浓度的测定

用紫外分光光度法，于苯扎溴铵特征吸收峰的２５６ｎｍ波长下测定溶液中苯扎溴铵浓度。对苯扎溴铵浓度≤１６３２μｇ／ｍｌ的溶液，测定结果的相对标准偏差≤１７６％。     

庆大霉素-藻酸钙三维缓释微球的药物释放研究

目的研制庆大霉素一藻酸钙三维缓释微球并调控其庆大霉素的释放。使其达到长期局部抗菌的效果。方法制作不同浓度T、S、U组庆大霉素-藻酸钙缓释凝珠,与庆大霉素-骨水泥颗粒Y组进行庆大霉索释放情况比较。通过不同时间点抽取浸泡液,送紫外分光光度法（UV）及金黄色葡萄球菌（SA）培养检测,由此计算出各组包封率、释放率,绘制庆大霉素释放曲线。结果4组样品（微生物法）的包封率及30d药物释放率分别为：U组（53．99％、36．31％）,S组（39．62％、27．55％）。T组（34．20％、30．83％）,Y组（100．00％、48．49％）。U组的包封率较高,30d释放庆大霉素的总量较大,更接近Y组。4组间差异有统计学意义（P〈0．01）。U、Y组庆大霉素的释放明显高于S、T组的释放。各组30d内庆大霉素的浓度几乎都能超过金黄色葡萄球菌的最低抑菌浓度（MIC）．即〉2μg／mI。结论U组载药缓释凝珠30d内的庆大霉索释放较为理想。可作为BMSCs的三维培养支架。