Fine structural dynamics showing functional changes of anterior pituitary cells in the rat

The cell types in the rat anterior pituitary were classified according to the function of hormone produced by each type cells. Depending upon the age and sex of the rat studied, the fine structure of the cell remarkably differs from each other. The name of cell type indicates the name (abbreviation) of hormone produced by each type cell, which is also divided into two or three subtypes according to the ultrastructure or developing stage viz. immature, intermediate and mature types. The immunocytochemistry is a useful method both for light and electron microscopy in order to study the activity of every cell organelles, because it is easy to indicate the localization of hormones in the cell. The anterior pituitary hormones are all proteins or polypeptides fragmented from the former, and making antibodies of these hormones is rather easy. Significance of every cell organelles in the endocrine function was clarified.     

Magnetic Resonance Imaging (MRI) of hormone-induced breast changes in young premenopausal women

Objectives

We conducted a pilot study to identify whether MRI parameters are sensitive to hormone-induced changes in the breast during the natural menstrual cycle and whether changes could also be observed during an oral contraceptive (OC) cycle.

Materials and Methods

The New York University Langone Medical Center Institutional Review Board approved this HIPAA-compliant prospective study. All participants provided written informed consent. Participants were aged 24-31 years.We measured several non-contrast breast MRI parameters during each week of a single menstrual cycle (among 9 women) and OC cycle (among 8 women). Hormones were measured to confirm ovulation and classify menstrual cycle phase among naturally cycling women and to monitor OC compliance among OC users. We investigated how the non-contrast MRI parameters of breast fibroglandular tissue (FGT), apparent diffusion coefficient (ADC), magnetization transfer ratio (MTR), and transverse relaxation time (T2) varied over the natural and the OC cycles.

Results

We observed significant increases in MRI FGT% and ADC in FGT, and longer T2 in FGT in the luteal vs. follicular phase of the menstrual cycle. We did not observe any consistent pattern of change for any of the MRI parameters among women using OCs.

Conclusions

MRI is sensitive to hormone-induced breast tissue changes during the menstrual cycle. Larger studies are needed to assess whether MRI is also sensitive to the effects of exogenous hormones, such as various OC formulations, on the breast tissue of young premenopausal women.     

EXAFS study of local atomic order about iodine in thyroxine,rat, human and sheep thyroids

Radioactive ¹²⁵I emits short‐range Auger electrons and represents a human health risk when incorporated in thyroglobulin of the thyroid. Quantitative evaluation of this risk can only be realised if local atomic order about iodine in the thyroid is known. Here, extended X‐ray absorption fine structure (EXAFS) has been used to probe the local structure about iodine in pure thyroid hormone, thyroxine. These data are consistent with a model where iodine is bound to a single iodinated carbon ring linked to an oxygen atom, similar to a previously published model for monoiodotyrosine, a major iodinated residue in thyroglobulin. Several structural models for the local environment of iodine from rat, human and sheep have been tested and these data are found to be compatible with a slightly modified environment with respect to that found for thyroxine. The best‐fit models include the following three components: (i) iodine covalently bonded to a tyrosine ring, as found for thyroxine; (ii) iodine bonded quasi‐covalently to a carbonyl ligand in partially filled (50%) sites; (iii) partially filled sites (50–40%) of carbonyl ligands, with oxygen at van der Waals distances from iodine. Advantages of using Fourier‐filtered EXAFS for complex crystal structures are discussed.     

DNA Vector Polyethyleneimine Affects Cell pH and Membrane Potential: A Time-Resolved Fluorescence Microscopy Study

Polyethyleneimine (PEI) is one of the very efficient nonviral vectors being developed and tested for artificial gene transfer into target cells. One of its serious limitations is the significant cytotoxicity of the large amounts of free PEI in the mixtures of DNA and PEI used for transfection. To further investigate the cellular effects of free PEI, we have analyzed the PEI-induced alterations of various cell parameters such as membrane heterogeneity and fluidity, cytoplasmic pH, and plasma membrane potential in a variety of cells such as Swiss 3T3 fibroblast, Chinese hamster ovary, insect cells SF9, plant cell line BY2, and Saccharomyces cerevisae. Fluorescence probes such as Nile red, SNARF-1, and cyanine dye DiSC₂(3), coupled with the technique of picosecond time-resolved fluorescence microscopy, were used in estimating the above-mentioned cell parameters. It was found that the cell membranes were largely unperturbed by PEI. However, the cytoplasmic pH showed an increase of 0.1–0.4 units when the cells were treated with PEI. The plasma membrane potential was found to be depolarized in S. cerevisae and Swiss 3T3 cells. These results suggest that the cytotoxic effects of PEI may partly originate from inhibition of regulation of cytoplasmic pH and plasma membrane potential. Further, it is proposed that the resultant cell alterations favors the transfection process.     

Magnetic resonance imaging tracking of alginate beads used for drug delivery of growth factors at sites of cardiac damage

Alginate-based beads labeled with contrast agent and loaded with vascular growth hormones were used for site-specific chronic delivery of hormones at the site of myocardial damage in a porcine model. Position of the beads within the pericardium could be monitored by MRI for optimal hormone delivery due to the presence of contrast agent. The beads facilitate the slow release of cytochrome c, myoglobin and methemoglobin used as protein models of growth factors. This application allows for site-specific delivery of hormones while the incorporated contrast agent in the beads provides a tool for MRI tracking in chronic studies.     

Magnetic-field-induced deformation of lipid membranes

The substantial effects of relatively low, steady magnetic fields less than 0.5 T up to high magnetic fields up to 30 T on the membrane potential and resistance of black lipid membranes of didodecyl phosphite and dipalmitoylphosphatidylcholine (DPPC) are presented. Also, the magnetic-field-induced fusion and division of DPPC liposomes are demonstrated. Such significant magnetoresponses should result in the magnetic orientation of the lipid molecules and associated undulation of the membranes. Thus, the addition to membranes of diamagnetic aromatics having a large magnetic anisotropy enhanced the magnetoresponses: larger changes in membrane potential and resistance and a lower shift of the onset magnetic-field, with abrupt changes in liposome sizes and membrane potential.     

A study of atomic iodine and molecular thallium iodide by X-ray photoelectron and auger electron spectroscopy

The I3d5/2 binding energy has been measured in atomic iodine, thallium iodide and cesium iodide by high temperature gas-phase photoelectron spectrscopy using Al K (1486.6 eV) X-rays. The iodine M₅N_4,5N_4,5 (¹G₄) Auger energies for TlI and CsI have also been measured and combined with binding energies to yield extra-atomic relaxation energies of 0.5 and O.3 eV, respectively, after corrections are applied to the Auger parameter. Charges were calculated using the simple potential model, which was also used to obtain an estimate of the atomic T14f binding energy. Two other estimates of the atomic T14f7/2 binding energy have also been calculated, both based on Dirac-Fock ΔSCF binding energies. The results of the three methods suggest a value of 125.3 ± 0.2 eV for T14f7/2.     

电泳沉积法制备YBaCuO厚膜工艺的研究

在极间距为 2 .5 cm的电泳容器中 ,以丙酮为分散介质 ,沉积速度随着粉末浓度和碘加入量的增加先增加后减小 ,最佳参数值 YBa Cu O粉末浓度 3g/ l,碘 0 .3/ l。在本实验设备条件下 ,外加直流电压应为 110 V。在 930℃下恒温 4小时就能达到固化效果 ,没有裂纹出现。固化膜对基带的附着力用划格法测量 ,按 ASTM( American Standards of Testing Mate-rial)标准可达 1级。     

高效液相色谱法同时测定化妆品中9种激素

建立了化妆品中9种激素的HPLC测定方法。样品经甲醇超声提取后,经ZORBAXExtend-C18柱分离,以甲醇-水(pH=8.0,0.02mol/L磷酸盐缓冲体系)为流动相,采用紫外检测器检测。9种激素分离良好并排除了样品中杂质峰的干扰,各激素在1—100mg/L范围内呈良好线性关系(r0.999),平均回收率在93.3%—107.2%之间,相对标准偏差为0.79%—2.07%(n=7),检出限为0.05—0.2mg/L。该方法可简便、快捷、准确的同时测定化妆品中9种激素。     

Studies on Trace Labelling of Bromsulphalein (BSP) with Radioiodine

Two methods have been studied for high specific activity trace iodination of Bromsulphalein (BSP) with radioiodine (¹³¹I). In the first method, BSP in aqueous solution is reacted with iodine and an oxidising agent – hydrogen peroxide or chloramine T. In the second method, iodination is carried out by electrolytically liberated iodine. The electrolytic method gives labelled BSP free from any labelled degradation products. The stability of ¹³¹I-labelled BSP in aqueous solution has been studied. The product has been found to remain more stable in aqueous solutions at a slightly acid pH (4…6.5) than in dilute alkaline solutions (pH 7…9.5).     

Mechanically alloyed Al-I composite materials

Mechanically alloyed aluminum-iodine composites with iodine concentrations from 4 to 17 wt% were prepared from elemental aluminum and iodine. A reference sample was prepared from aluminum and AlI₃. A shaker mill and an attritor mill, operating at both room temperature and liquid nitrogen temperature, were used for preparation. Materials were characterized by electron microscopy and X-ray diffraction. The iodine release upon heating was studied using thermogravimetry. Mechanical alloying was found to be effective for preparation of Al-I composites that do not release iodine until the material is brought to high temperatures. Mechanical alloying in nitrogen gas at liquid nitrogen temperature was more effective in preparing stabilized Al-I composites than milling at room temperature. Iodine was not retained in materials milled directly in liquid nitrogen. In addition to poorly crystalline AlI₃, other iodine compounds were present in the products. Assuming that the products are similar to other mechanically alloyed materials, it is expected that iodine is mixed with aluminum on the atomic scale, forming metastable Al-I compounds where iodine may be bonded to aluminum more strongly than in AlI₃, explaining why their thermal decomposition and respective iodine release occur at higher temperatures compared to decomposition and boiling of AlI₃.     

氧碘化学激光器废气排放污染评价北大核心CSCD

氧碘化学激光器运行过程中会将氯气、碘蒸气等有毒有害物质排入大气,对工作场所空气质量和人员健康存在安全隐患。采用点源扩散的高斯模式,建立了小风条件下氧碘化学激光器废气的扩散模型,结合工作场地人员分布情况,计算得到激光器废气排放后15min内,距地面1.5m高度、距排放点500m范围内废气中有毒成分氯气和碘的质量浓度空间分布。根据质量浓度空间分布情况,选取采样点,以Na_2SO_3溶液作为吸收液对氯气和碘进行了同时采样,并采取离子色谱测量了吸收液中氯离子和碘离子的质量浓度。结果表明:氧碘化学激光器废气排入大气后,氯气质量浓度最高为0.200mg/m^3,碘蒸气质量浓度小于检测方法的检出限0.030mg/m^3,低于国家职业卫生标准规定的最高容许质量浓度限值1mg/m^3。     

电感耦合等离子体-质谱法快速测定尿中的碘

在优化的仪器条件下,以In作内标,采用电感耦合等离子体-质谱法（ICP-MS）测定尿中碘元素.样品经稀释离心后直接上机测定.该方法线性范围为宽、灵敏度高、重现性好、线性相关系数为0.99997、回收率为95.3％-98.1％、精密度为1.15％-2.08％、用ICP-MS法和国标方法同时测定25份尿样中碘含量,结果经统计学分析,T为0.158小于2.021,P＞0.05,说明两种方法测定结果之间无显著性差异.ICP-MS方法简便快速且易于操作,适用于大批量尿样品中碘含量的测定.     

Developmental iodine deficiency and hypothyroidism impair neural development in rat hippocampus: involvement of doublecortin and NCAM-180

Background  

Developmental iodine deficiency results in inadequate thyroid hormone (TH), which damages the hippocampus. Here, we explored the roles of hippocampal doublecortin and neural cell adhesion molecule (NCAM)-180 in developmental iodine deficiency and hypothyroidism.     

抗艾滋病药物司他夫定与血液蛋白相互作用的研究

研究药物和血液中载体蛋白的相互作用对阐明药物在体内的转运、分布、代谢和药效等具有重要意义。运用稳态荧光、紫外-可见吸收光谱、动力学瞬态发射光谱和循环伏安法研究了抗艾滋病(HIV)药物司他夫定(stavudine,D4T)对人血清白蛋白(HSA)、牛血清白蛋白(BSA)和血红蛋白(Hb)三种血液蛋白的荧光猝灭机制,均为静态猝灭;得出不同温度(300 K,310 K,320 K)下D4T和载体的结合常数K_a(K_a的大小顺序为Hb＞HSA＞BSA)和结合位点数n(n均为1);分析二者结合过程的热力参数ΔH,ΔS和ΔG,三种血液蛋白均为ΔG＞0,ΔH＞0,说明D4T和载体的结合是一种自发的放热过程,同时由ΔH＜0,ΔS＜0,推测出D4T与HSA,BSA和Hb之间的结合力都为氢键和范德华力;根据Frster非辐射能量转移理论(FRET)分析了供体(蛋白)和受体(D4T)之间发生能量转移的可能性并计算了结合距离R₀和r,其中r＜7 nm且0.5R₀＜r＜1.5R₀,表明从HSA,BSA和Hb到D4T之间发生能量转移的可能性很大。同时利用同步荧光,三维荧光和圆二色谱法得出,D4T与载体结合时对载体(HSA,BSA和Hb)的二级结构无影响,且三级构象变化不大。通过本文实验可知,HSA,BSA和Hb三种血液蛋白均可作为运输D4T到靶位置的良好载体蛋白,这些结果为更深入研究D4T药物分子设计和抗HIV作用的应用提供有利的实验依据。     

Structural and permeability sensitivity of cells to low intensity ultrasound: Infrared and fluorescence evidence in vitro

This work is focused on the in vitro study of the effects induced by medical ultrasound (US) in murine fibroblast cells (NIH-3T3) at a low-intensity of exposure (spatial peak temporal average intensity I_ta < 0.1 W cm⁻²). Conventional 1 MHz and 3 MHz US devices of therapeutic relevance were employed with varying intensity and exposure time parameters. In this framework, upon cells exposure to US, structural changes at the molecular level were evaluated by infrared spectroscopy; alterations in plasma membrane permeability were monitored in terms of uptake efficiency of small cell-impermeable model drug molecules, as measured by fluorescence microscopy and flow cytometry. The results were related to the cell viability and combined with the statistical PCA analysis, confirming that NIH-3T3 cells are sensitive to therapeutic US, mainly at 1 MHz, with time-dependent increases in both efficiency of uptake, recovery of wild-type membrane permeability, and the size of molecules entering 3T3. On the contrary, the exposures from US equipment at 3 MHz show uptakes comparable with untreated samples.     

Depth profiling of horse fat tissue using mid-infrared and confocal Raman microscope

Attenuated total reflection Fourier transform infrared (ATR FT-IR) and confocal Raman microscopes were used to record horse fat depth profiles. The dependence of the unsaturation level and the iodine value on the distance from the skin were studied for tissue of the plane 10?×?10?mm and thickness of 30?mm. The degree of unsaturation was determined as well as the content of carotenoids and retinoids in horse fat were analyzed using the same spectroscopic methods. Clear and characteristic changes of the studied material parameters depending on the distance from the skin were described.     

Bi2Sr2Co2O8体系中Pb替代及I插层对其结构和物性的影响

自今年3月在NaxCo2O4 Yh2o中发现超导电性以来,具有层状结构的Co系氧化物又受到人们广泛的关注.本文在成功合成具有misfit层状结构Bi2Sr2Co2Oy单相样品的基础上,通过Pb对Bi的部分替代、以及I的插层,成功地使其c轴由1.49nm增至1.87nm,并对其输运性质和磁性质进行了系统研究.结果发现:Pb的部分替代并没有使该体系的电阻-温度关系行为发生显著变化,但在低温下使样品呈现自旋玻璃态行为;I的插入不仅使其c轴长度增加,而且样品变为半导体,并不呈现超导电性,在低温下同样呈现自旋玻璃态行为.同时对Pb替代及I插层效应进行了讨论.     

Sinoporphyrin sodium triggered sono-photodynamic effects on breast cancer both in vitro and in vivo

Sono-photodynamic therapy (SPDT) is a promising anti-cancer strategy. Briefly, SPDT combines ultrasound and light to activate sensitizers that produce mechanical, sonochemical and photochemical activities. Sinoporphyrin sodium (DVDMS) is a newly identified sensitizer that shows great potential in both sonodynamic therapy (SDT) and photodynamic therapy (PDT). In this study, we primarily evaluated the combined effects of SDT and PDT by using DVDMS on breast cancer both in vitro and in vivo. In vitro, DVDMS-SPDT elicits much serious cytotoxicity compared with either SDT or PDT alone by MTT and colony formation assays. 2′,7′-Dichlorodihydrofluo-rescein-diacetate (DCFH-DA) and dihydroethidium (DHE) staining revealed that intracellular reactive oxygen species (ROS) were significantly increased in groups given combined therapy. Terephthalic acid (TA) method and FD500-uptake assay reflected that cavitational effects and cell membrane permeability changes after ultrasound irradiation were also involved in the enhancement of combination therapy. In vivo, DVDMS-SPDT markedly inhibits the tumor volume and tumor weight growth. Hematoxylin-eosin staining and immunohistochemistry analysis show DVDMS-SPDT greatly suppressed tumor proliferation. Further, DVDMS-SPDT significantly inhibits tumor lung metastasis in the highly metastatic 4T1 mouse xenograft model, which is consistent well with the in vitro findings evaluated by transwell assay. Moreover, DVDMS-SPDT did not produces obvious effect on body weight and major organs in 4T1 xenograft model. The results suggest that by combination SDT and PDT, the sensitizer DVDMS would produce much better therapeutic effects, and DVDMS-SPDT may be a potential strategy against highly metastatic breast cancer.     

Transformations of iodine species inside elliptical channels of AlPO4‐11 crystals at low temperature: a Raman study

Raman spectra of iodine species confined in one‐dimensional elliptical channels of AlPO₄‐11 (AEL) crystals have been studied from room temperature down to −196 °C. As temperature decreases, thermal fluctuations of individual iodine molecules confined in AEL channels are slowed down and they prefer to rotate to channel axis direction, which increases the population of iodine molecules along channel axis (i.e., lying molecules and chains). Such temperature‐driven orientation transformation of iodine molecules is found to be reversible upon heating up to room temperature. The experimental observations are in good agreement with our theoretical simulations by molecular dynamics on low density iodine‐filled AEL crystals. We thus provide a new way to modulate the orientation of iodine molecules in nanochannels, which may have implications in low‐temperature‐sensitive nanoscale devices. Copyright © 2015 John Wiley & Sons, Ltd.