CORAL PHOTOBIOLOGY STUDIED WITH A NEW IMAGING PULSE AMPLITUDE MODULATED FLUOROMETER1

A new high‐resolution imaging fluorometer (Imaging‐PAM) was used to identify heterogeneity of photosynthetic activity across the surface of corals. Three species were examined: Acropora nobilis Dana (branching), Goniastrea australiensis Edwards & Haime (massive), and Pavona decussata Dana (plate). Images of fluorescence parameters (F, F_m′, effective quantum yield, optimal quantum yield, electron transport rate, relative photosynthetic rate, and non‐photochemical quenching) allowed heterogeneity to be detected in terms of position on colony and indicated that the photosynthetic activity of polyp and coenosarc tissues responded differently to changing light for all three species. The Imaging‐PAM offers a special routine, with which images of PAR absorption (absorptivity) are obtained. In this way, for the first time it has become possible to derive images of the relative photosynthesis rate. Polyps had a lower PAR absorptivity than coenosarc tissue for A. nobilis and P. decussata, whereas G. australiensis showed the opposite pattern. Acropora nobilis showed heterogeneity along the longitudinal axis of the branch, which could be differentiated from the effect of variations in illumination across the rugose and curved surface. Diel changes were apparent and influenced the longitudinal heterogeneity along the A. nobilis branch. Images were also obtained showing the degree of photoinhibition caused by high‐light stress across a coral surface at a hitherto unobtainable level of resolution.     

Imaging mass spectroscopy delineates the thinned and thickened walls of intracranial aneurysms

Object

The wall thickness of intracranial aneurysms (IAs) is heterogeneous. Although thinning of the IA wall is thought to contribute to IA rupture, the underlying mechanism remains poorly understood. Recently, imaging mass spectroscopy (IMS) has been used to reveal the distribution of phospholipids in vascular diseases. To investigate the feature of phospholipid composition of IA walls, we conducted IMS in a rat model of experimentally induced IA.

Biomolecular investigation of human substantia nigra in Parkinson's disease by synchrotron radiation Fourier transform infrared microspectroscopy

Synchrotron radiation based-Fourier transform infrared microspectroscopy was used for preliminary investigation of the chemical composition and morphologies of the human substantia nigra of brain between normal and Parkinson's diseased tissues. The studies were carried out for thin tissue sections, focusing more particularly on nerve cell bodies, that are affected in Parkinson's disease (PD). The major spectral differences between normal (control) and PD tissues were identified at the following vibrational frequencies: 2930, 2850, 1655, 1380, 1236, 1173 and 1086 cm(-1). The infrared imaging of these biochemical markers show that for control cases the protein and nucleic acids functional groups (bands at: approximately 3300, approximately 3100, approximately 1655, approximately 1545, approximately 1240, approximately 1080 cm(-1)) are located mainly in the cell body. The spatial distribution of the band at 1740 cm(-1) (ester carbonyl stretching band) is quite dissimilar to the others, while it exhibits a minimal concentration in the cell body area. Contrarily, in PD samples, no clear evidence of variation of any of the vibrational fingerprint between cell body and the surrounding was noticed. Moreover, decrease of protein to lipid ratio as well as increase of amide I/amide II ratio were observed for PD case. The preliminary results strengthen the hypothesis that PD is a multietiological disorder. Moreover, the reported results clearly indicate that, in addition to a distinct visual observation, the diseased nerve cells exhibits change of their biochemical composition. It suggests that disturbances of normal functioning of SN neurons appear before their morphological atrophy.     

Evaluation of known and novel inhibitors of Orai1-mediated store operated Ca2+ entry in MDA-MB-231 breast cancer cells using a Fluorescence Imaging Plate Reader assay

The Orai1 Ca²⁺ permeable ion channel is an important component of store operated Ca²⁺ entry (SOCE) in cells. It’s over-expression in basal molecular subtype breast cancers has been linked with poor prognosis, making it a potential target for drug development. We pharmacologically characterised a number of reported inhibitors of SOCE in MDA-MB-231 breast cancer cells using a convenient Fluorescence Imaging Plate Reader (FLIPR) assay, and show that the rank order of their potencies in this assay is the same as those reported in a wide range of published assays. The assay was also used in a screening project seeking novel inhibitors. Following a broad literature survey of classes of calcium channel inhibitors we used simplified ligand structures to query the ZINC on-line database, and following two iterations of refinement selected a novel Orai1-selective dichlorophenyltriazole hit compound. Analogues of this were synthesized and evaluated in the FLIPR assay to develop structure–activity relationships (SAR) for the three domains of the hit; triazole (head), dichlorophenyl (body) and substituted phenyl (tail). For this series, the results suggested the need for a lipophilic tail domain and an out-of-plane twist between the body and tail domains.     

影像学方法在淋巴瘤疗效评估中的应用

淋巴瘤通过放化疗可获得很高的治愈率。治疗过程中,疗效评估对于评价或调整治疗方案至关重要。基于病灶形态学改变的传统影像学技术如计算机断层扫描(computed tomography,CT)与磁共振成像(magnetic resonance imaging,MRI)技术在评估淋巴瘤疗效时存在一定的局限性;磁共振加权成像(diffusion-weighted imaging,DWI)结合水分子表观弥散系数(apparent diffusion coefficient,ADC)从分子水平反映疾病的病理生理状态,是一种功能成像新技术;而正电子发射断层显像/X线计算机体层成像(Positron emission tomography/computed tomography,PET/CT)将肿瘤的代谢与形态相结合,是一种新型的功能成像技术,已广泛应用于淋巴瘤患者的分期、疗效监测和预后评估中,可较其他影像学技术更准确的评估疗效;PET/MRI技术在淋巴瘤方面的临床应用研究目前尚处于初步阶段,其临床价值尚需进一步探讨。     

可逆性后部脑病综合征发病机制进展及影像学表现

可逆性后部脑病综合征是一种与多种致病因素相关的临床影像学综合征,以头痛、癫痫发作、精神症状、视觉障碍、意识障碍为主要临床表现,影像学以顶枕叶可逆性脑白质病变为主。该病如果能够得到及时的诊断与治疗,大部分患者的临床症状及影像学改变可以消失;如果不能得到及时正确的诊疗,可能会发生一些不可逆的损伤,严重时甚至危及生命,因此加强对本病的认识、诊断及治疗至关重要。目前该病的发病机制尚不明确,现对其发病机制进展及影像学表现进行综述,以提高临床医师对该病的病理生理机制的认识及提高诊断水平。     

In situ quantification of aberrant p53 in colorectal neoplasia

Aberrant p53 protein accumulation was measured immunohistologically in 342 colorectal paraffin-embedded tissue sections from 115 patients (24 with adenocarcinoma, 59 with adenoma and 32 'hospital controls'). Subjective scoring was compared with quantitative cell imaging, including dichotomous (p53⁺/p53^-) status, ng p53^mut mg^-1 enterocyte protein, and tumour burden and patient body 'burden' of aberrant p53. A total of 62.5% cancer patients, 23.7% adenoma patients and 3.1% hospital controls were accorded p53⁺ status on the basis of p53 quantification. Quantitative p53⁺/p53^- assignment had a stronger inverse association with survival (χ²=6.17, p=0.013, Kaplan-Meier test) than subjective 'visual estimation' (χ²=0.57, p=0.449). There was a strong inverse relationship between the p53 'body burden' and the months of post-diagnosis survival (hazard ratio=1.42, p=0.0004, Cox proportional hazards). Absolute quantification for inactivated p53 permits objective and reproducible scoring, adjusts for intra-laboratory immunostaining 'batch effects', corrects for fixation artefacts, and standardizes for inter-laboratory differences in fixation, antibody selection and staining method. Clinically, in situ quantification of p53 will permit more accurate survival prognoses and will inform therapy selection and dose. Ultimately, accurate quantitative tissue/blood p53 correlations may provide a minimally invasive and systemic surrogate measure for these same clinical purposes.     

使用非侵入的神经影像方法解码人类思维

随着神经影像技术的发展,“读脑机器”在不久的将来可能会变成现实。在众多实现“读脑机器”的技术中,使用基于血氧水平依赖的脑功能磁共振技术的神经解码方法则是非常有希望的一种技术。在本报告中,我们结合我们实验室最近开展的两个研究工作,说明了使用功能磁共振技术进行神经解码的一般方法及其应用。本领域的发展很快,所有的这些工作让我们对发明“读脑机器”充满了期待。但是,与此同时,我们也应该看到目前还存在着很多技术的局限和挑战。本报告的最后,我们也对这些局限和挑战进行了一些讨论。     

慢性肾脏病患者心脏结构与功能变化的超声心动图研究

目的:研究慢性肾脏病(CKD)患者心脏结构及功能的变化.方法:选择我院肾内科175例慢性肾脏病未透析患者,按照2003年美国国家肾脏基金会-肾脏病转归质量(NKF-K/DOQI)指南的标准进行分期,观察所有患者心脏结构及功能在超声中的变化.结果:慢性肾脏病患者随着肾功能的恶化,各组之间比较,室间隔厚度(IVST)、左心室后壁厚度(LVPW)、左心室心肌重量指数(LVMI)、左心室舒张末期内径(LVDd)、左心房内径(LAD)具有升高的趋势(P＜0.05,P＜0.01);但E/A比值未出现伴随着肾功能恶化而逐渐减低的趋势(P＞0.05);射血分数(EF)、短轴缩短卒(FS)在各期之间无明显变化(P＞0.05);而TVI技术测定的Em、Em/Am具有显著减低的趋势(P＜0.05,P＜0.01);瓣膜返流以二尖瓣返流为主.结论:慢性肾脏病患者心脏结构与功能随肾功能减退而加重,超声心动图检查结合组织速度显像(TVI)技术能更好地检测心脏结构和功能变化,尤其是检测左心室舒张功能障碍.