In Situ Thermal Denaturation of Proteins in Dunning AT-1 Prostate Cancer Cells: Implication for Hyperthermic Cell Injury

The in situ thermal protein denaturation and its correlation with direct hyperthermic cell injury in Dunning AT-1 prostate tumor cells were investigated in this study. The in situ thermal protein denaturation was studied using both Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The FTIR spectra at different temperatures show changes in protein secondary structure (from alpha helix to extended beta sheet) during in situ thermal protein denaturation within AT-1 cells. Calorimetric studies using DSC show that endothermic heat release is associated with the in situ thermal protein denaturation. Furthermore, both the secondary structure changes detected by FTIR and the calorimetric changes detected by DSC were quantified and the kinetics of the overall in situ thermal protein denaturation was derived under different heating conditions. The onset temperature where the overall in situ thermal protein denaturation is first detectable was found to be scanning rate dependent (approximately 41 degrees C at 2 degrees C min(-1) and approximately 44 degrees C at 5 degrees C min(-1)). The kinetics of the overall in situ thermal protein denaturation was derived from both DSC and FTIR measurements and was fit using kinetic and statistical models. The kinetic data determined by FTIR and DSC under the same heating conditions match well with each other. The activation energy of the overall in situ thermal protein denaturation is found to be strongly dependent on the temperature range considered (the activation energy ranges from approximately 110 kJ mol(-1) between 44 and 90 degrees C to approximately 750 kJ mol(-1) between 44 and 50 degrees C). However, its dependence on heating rate is negligible. Several denaturation peaks, including a dominant one between approximately 62 and 65 degrees C, are identifiable from both the DSC and the FTIR results. To investigate directly the relationship between thermally induced cell injury and the in situ thermal protein denaturation, both acute (propidium iodide dye exclusion, assessed 3-h postthermal treatment) and chronic (clonogenics, assessed 7-day postthermal treatment) cell injury were quantified using AT-1 cells prepared under the same conditions as for the DSC protein studies. Comparisons of the results from the cell injury studies and the DSC protein denaturation studies show that the overall in situ thermal protein denaturation correlates well with both the acute and the chronic cell injury, which suggests that overall in situ thermal protein denaturation is an important mechanism of direct hyperthermic cell injury in AT-1 cells at the macromolecular level.     

鹿茸的FTIR性质与传统质量等级之关系

研究了鹿茸的傅里叶变换红外光谱(FTIR)特性与传统质量的关系。发现鹿茸质量等级的内在数字化“Z”值规律性。从而为鹿茸片特别是用目前方法难于确定质量等级的鹿茸粉,提供了质量等级的客观指标。     

煤快速加氢热解焦油组成的分析

采用溶剂萃取－化学处理－柱层析相结合的预处理分离程序、色－质联用和色－红联用结合色谱保留值的定性方法,分析研究了内蒙东胜煤快速加氢热解焦油的化学成分和结构,推测鉴定出２００多种化合物,并对具有代表性的１９种多环芳烃进行了定量分析,讨论了快速加氢热解焦油化学成分的结构特征。     

FTIR Characterization of the Secondary Structure of Insulin Encapsulated within Liposome

Aim:To determine the secondary structure of insulin encapsulated within liposome.Methods:The secondary structure of native insulin,mixture of insulin with liposome(sample I) and insulin encapsulated within liposome(sample Ⅱ) were determined by FTIR(Fourier Transform Infrared) spectroscopy.Results:The secondary structure of insulin encspsulated within liposome(Ⅱ） are similar with the secondary structure of native insulin.The difference existed in the amount of α-helices (from 36% of insulin to 31% of sample Ⅱ）and β-sheet(from 48% of insulin to 51% of sample Ⅱ).The content of α-helices and β-sheet of insulin in sample I was found to be very close to that of sample Ⅱ.The results revealed that the insulin encapsulated within liposome possibly spread on the surface of liposome,without inserting into the liposome membrane.Coclusion:The secondary structure of insulin encapsulated within liposome is similar with the native insulin.     

漫反射FT-IR法测定复合维生素B片剂中维生素B2的含量

目的：建立复合维生素B片剂中维生素B2含量的检测方法。方法：采用中红外漫反射定量分析技术，潮定了复合维生素B片剂中维生素B2的含量。结果：可直接测定出样品中维生素B2的含量，且吸光度与维生素B2的质量百分数成良好的线性关系，平均回收率为99．79％，RSD为1.85％。结论：本方法准确、可靠，可用于复合维生素B片剂中维生素B2的含量测定。     

肉苁蓉药材与盐生肉苁蓉培养细胞的主要成分对比研究

目的研究肉苁蓉药材与盐生肉苁蓉培养细胞的苯乙醇苷类成分差异。方法利用傅里叶变换红外光谱(FTIR)和HPLC技术进行成分对比分析。结果FTIR的分析结果表明，盐生肉苁蓉培养细胞的红外指纹谱图与肉苁蓉药材具有一定相似性；HPLC的分析结果表明，盐生肉苁蓉细胞中所含的主要成分和肉苁蓉药材相似，只是含量有差异。结论从整体上看，盐生肉苁蓉培养细胞中所含成分种类较多，且大部分含量较高，其中洋丁香酚苷(类叶升麻苷)和松果菊苷的含量大幅度高于肉苁蓉药材。     

The effect of universal adhesives on dentine collagen

ObjectivesThe purpose of the study was to evaluate the integrity of dentine type I collagen after self-etching (SE) treatments with strong and mild universal adhesives.MethodsCoronal dentine specimens (n = 10/product) were imaged by optical microscopy and analyzed by ATR-FTIR spectroscopy before and after treatment with 32% phosphoric acid gel (PA-negative control), 17% neutral EDTA (ED-positive control) conditioners and Adhese Universal (AD), Clearfil Universal Bond Quick (CQ), G-Premio Bond (GP), Prelude One (PR) and Scotchbond Universal (SB) adhesives. From the spectroscopic analysis the following parameters were determined: a) Extent of dentine demineralization (DM%) and b) percentage area of the Amide I curve-fitted components of β-turns, 3₁₀-helix/β-turns, α-helix, random coils, β-sheets and collagen maturation (R) index. Statistical analysis was performed by one-way ANOVA (DM%), paired t-test/Wilcoxon test (Amide I components) and Spearman correlation coefficient (DM% vs Amide I components) at an a = 0.05 level.ResultsPA, ED and GP removed the smear-layer and opened tubule orifices, whereas all other treatments removed only the intratubular smear-layer fraction. The ranking of the statistically significant differences in DM% was PA > GP > ED > AD, SB, CQ, PR, with AD being significantly different from PR. Regarding the Amide I components, PA demonstrated a significant reduction in β-turns, α-helices and an increase in β-sheets, GP a reduction in β-turns, AD an increase in β-turns and random coils, and CQ an increase in β-turns. PR, SB and ED showed insignificant differences in all the Amide I components. Significant correlations were found between DM%-random coils and DM%-R.SignificanceThe universal adhesives used in the SE mode induced none to minimal changes in dentine collagen structure, without evidence of the destabilization pattern observed after conventional phosphoric acid treatments.     

通过FTIR与DSC分析医疗器械包装材料成分特性

介绍了医疗器械塑料包装材料的特性，通过FTIR和DSC简单快捷的分析了包装材料聚乙烯与聚丙烯的成分及聚合度，为以后相关医疗器械包装材料的残留单体及添加剂等有害物质分析确认提供参考。     

Quantification of the types of water in Eudragit RLPO polymer and the kinetics of water loss using FTIR

Coalescence of polymer particles in polymer matrix tablets influences drug release. The literature has emphasized that coalescence occurs above the glass transition temperature (T_g) of the polymer and that water may plasticize (lower T_g) the polymer. However, we have shown previously that nonplasticizing water also influences coalescence of Eudragit RLPO; so there is a need to quantify the different types of water in Eudragit RLPO. The purpose of this study was to distinguish the types of water present in Eudragit RLPO polymer and to investigate the water loss kinetics for these different types of water. Eudragit RLPO was stored in tightly closed chambers at various relative humidities (0, 33, 56, 75, and 94%) until equilibrium was reached. Fourier transform infrared spectroscopy (FTIR)-DRIFTS was used to investigate molecular interactions between water and polymer, and water loss over time. Using a curve fitting procedure, the water region (3100–3700 cm⁻¹) of the spectra was analyzed, and used to identify water present in differing environments in the polymer and to determine the water loss kinetics upon purging the sample with dry compressed air. It was found that four environments can be differentiated (dipole interaction of water with quaternary ammonium groups, water cluster, and water indirectly and directly binding to the carbonyl groups of the polymer) but it was not possible to distinguish whether the different types of water were lost at different rates. It is suggested that water is trapped in the polymer in different forms and this should be considered when investigating coalescence of polymer matrices.     

Characterization of the Apatite Crystals of Bone and their Maturation in Osteoblast Cell Culture: Comparison with Native Bone Crystals

Calcium phosphate crystals deposited in the organic matrix synthesized by chick bone osteoblasts in culture were studied by x-ray and electron diffraction, Fourier transform infrared spectroscopy and chemical composition. The amounts of mineral phase deposited with time and the extent of calcification (% of mineral phase in the tissue) were also determined as a function of time, as were the nature of the changes in the short range order of the crystals. The amount of mineral deposited and the extent of calcification increased with time; the tissue not only contained more crystals of apatite, but the extent of calcification also increased with time as it does in vivo. After 30 days of culture the extent of calcification in the cell culture matrix was similar to that in late chick embryonic and early postnatal chick tibiae. The nature of the CO₃ and HPD₄ environments were similar to those found in vivo although the concentrations of these ions and the changes in their concentrations with time appeared to develop more slowly in cell culture than they do in vivo. However, the general overall pathway of maturation was similar in cell culture to that observed in vivo.