Loss of p15/Ink4b accompanies tumorigenesis triggered by complex DNA double-strand breaks

DNA double-strand breaks (DSBs) are the most deleterious lesion inflicted by ionizing radiation. Although DSBs are potentially carcinogenic, it is not clear whether complex DSBs that are refractory to repair are more potently tumorigenic compared with simple breaks that can be rapidly repaired, correctly or incorrectly, by mammalian cells. We previously demonstrated that complex DSBs induced by high-linear energy transfer (LET) Fe ions are repaired slowly and incompletely, whereas those induced by low-LET gamma rays are repaired efficiently by mammalian cells. To determine whether Fe-induced DSBs are more potently tumorigenic than gamma ray-induced breaks, we irradiated 'sensitized' murine astrocytes that were deficient in Ink4a and Arf tumor suppressors and injected the surviving cells subcutaneously into nude mice. Using this model system, we find that Fe ions are potently tumorigenic, generating tumors with significantly higher frequency and shorter latency compared with tumors generated by gamma rays. Tumor formation by Fe-irradiated cells is accompanied by rampant genomic instability and multiple genomic changes, the most interesting of which is loss of the p15/Ink4b tumor suppressor due to deletion of a chromosomal region harboring the CDKN2A and CDKN2B loci. The additional loss of p15/Ink4b in tumors derived from cells that are already deficient in p16/Ink4a bolsters the hypothesis that p15 plays an important role in tumor suppression, especially in the absence of p16. Indeed, we find that reexpression of p15 in tumor-derived cells significantly attenuates the tumorigenic potential of these cells, indicating that p15 loss may be a critical event in tumorigenesis triggered by complex DSBs.

核素131I胆道腔内辐照支架的制作和动物实验及临床应用研究

恶性梗阻性黄疸(malignant obstructive jaundice,MOJ)发现时多为晚期,如不治疗生存期仅3个月。由于肿瘤位置特殊、患者一般情况较差,仅5%～20%的患者可行外科切除和分流手术,并且手术死亡率相当高,分流术病死率高达10%～43%。1974年Molnar和Stocknm首先采用PTCD术（经皮肝胆管内外引流术，Percutaneous Transhepatic Cholangic Drainage,PTCD）,使MOJ患者的临床症状得到缓解, 获得进一步治疗的机会。1989年金属支架开始应用于胆道系统,恢复了胆汁的生理性引流,并使大多数患者拔除引流管,提高了生活质量,成为非手术治疗MOJ的首选方法。但肿瘤生长是造成支架堵塞、黄疸复发的主要原因。文献报道MOJ患者放置金属支架后,支架堵塞的概率达20%～86%,其中大多数由肿瘤生长通过支架网眼或超过支架边缘引起。因此,在支架置放的同时如何积极控制肿瘤生长成为提高疗效的关键问题。MOJ的局部治疗方法有多种,但都存在不足之处。国内学者采用动脉化疗栓塞结合PTCD或支架置放的方法治疗MOJ,使患者的生存期得到延长。但引起MOJ的胆管癌、淋巴结转移癌、胰腺癌、壶腹癌多为少血供肿瘤,而且由于血供特殊,大部分病例碘油沉积欠佳,因此动脉化疗栓塞对这类肿瘤的作用是有限的。外辐照治疗对胆管癌、淋巴结转移癌、胰腺癌、壶腹癌等引起MOJ的肿瘤有一定疗效,并与胆道引流术结合应用于上述肿瘤引起的MOJ。由于瘤体周围有肝脏、胰腺、胃肠道、肾脏等对射线敏感的器官, 限制了外辐照剂量,影响了疗效的提高。近几年,一种斩新的治疗手段正在应用于临床，就是通过PTCD手术时建立的通道再行腔内辐照治疗(核素内辐照治疗),可以较好的控制肿瘤继续生长，抑制支架再狭窄的发生,可使MOJ的治疗取得更好的效果。本研究的目的就是探索胆道内辐照支架制作的可行性，并设计特别的施源器，其具体方法可以简述为：以球囊扩张器扩张重度狭窄胆管+置入特制的二腔单囊管+腔内低剂量率放疗+腔内热频热疗+胆管引流等联合方法治疗。同时，就该二腔单囊管内辐照支架的安全性进行动物实验，从分子生物学、核医学的角度阐述了实验研究的机理和病理改变，同时进行了临床的应用研究，探讨胆道支架发生再阻塞的相关因素及对策，进一步提高（MOJ）患者的生存期。本工作结果总结如下： 1 对放射源和施源器均进行了改进，放射源为液态放射性核素131I，施源器为可调节的长柱形球囊，是专门设计的硅橡胶二腔单囊管，其功能为：中腔通接胆管腔（蓝色），具有引流胆汁作用；另一腔管连接球囊（绿色），是长柱状形可调节长短的球囊，囊内装填放射性液态核素131I；囊内还设置射频加热电极，能加热升温。另外，还可以根据肿瘤的大小和长度，来调节施源器的长度（长柱形球囊），一般照射长度超出支架两端1-2cm。二腔单囊管内辐照支架的特点：剂量分布合理，低剂量率效应，射线能量适中，放疗、热疗同步实施，引流、扩张和局部用药作用。与其他治疗方法比较，这一核医学治疗技术的最大优点是：大直径柱状液态源，近似面源，液囊适形病变胆管腔，均匀贴紧病灶壁，剂量分布合理，γ射线能量适中，低剂量率持续照射，同时联合射频温热治疗及胆道引流、局部用药对症处理等。 2 动物实验研究结果指出，囊装液态131I支架对胆管壁的放射性损伤随131I放射性活度的增加而逐渐加重,呈现明显的放射性活度效应关系。而普通支架组胆管壁无放射性损伤,但是胆管壁粘膜层和肌层增生较131I支架组重,胆管出现再狭窄倾向。本研究为临床合理应用131I支架治疗胆管癌及胆管良性狭窄选择合适的131I放射性活度,提供了必要的剂量学和基础研究依据。 3 动物实验研究结果表明,131I支架组犬胆管组织Fas表达较普通支架组明显,且其表达水平的变化与犬胆管壁平滑肌细胞凋亡的检测结果相同。131I支架组胆管腔面积比普通支架组明显增加,胆管狭窄程度比普通支架组轻。这主要是由于131I辐射促进Fas 基因表达,诱导增殖性平滑肌细胞凋亡,从而减轻胆管损伤后愈合过程中的管腔狭窄。 4． 胆道恶性梗阻胆道腔内囊装液态131I辐照治疗施源的直径为8mm时是胆管充分扩张的最低限度,根据近距离放疗的剂量学特点,它能保证胆管癌腔内辐照治疗时将施源管因素导致的放疗反应和局部肿瘤复发减至最低。并具有创伤小,操作简单,疗效明显,易被患者接受的特点。 5．囊装液态131I治疗恶性梗阻性黄疸（肝门部胆管癌18例），临床疗效满意，随访7～21个月,3个月生存率83.33 %(15/ 18)；6个月生存率72.22%(13/18)；9个月生存率56.25%(12/16)；12个月生存率46.15%(6/13),15个月生存率36.33%(4/11)；18个月生存率22.22%(2/9),21个月生存率28.57%(2/7)。4例发生并发症,其中2例为放射性胆管炎胆道出血,1例为胆汁性腹膜炎,另1例是胰瘘胰腺炎

Excretion pattern investigation of urinary normal and modified nucleosides of breast cancer patients by RP-HPLC and factor analysis method

Modified nucleosides, formed post-transcriptionally in RNA by a number of modification enzymes, are excreted in abnormal levels in the urine of patients with malignant tumors. To test their usefulness as tumor markers, and to compare them with the conventional tumor markers, a reversed-phase high-performance liquid chromatographic (RP-HPLC) method and a factor analysis method have been used to study the excretion pattern of nucleosides of breast cancer patients. A clear cut differentiation of the breast cancer group and the healthy individuals in two clusters without overlapping was obtained. Copyright (C) 2000 John Wiley & Sons, Ltd.

On Combining Morphological Component Analysis and Concentric Morphology Model for Mammographic Mass Detection

Mammographic mass detection is an important task for the early diagnosis of breast cancer. However, it is difficult to distinguish masses from normal regions because of their abundant morphological characteristics and ambiguous margins. To improve the mass detection performance, it is essential to effectively preprocess mammogram to preserve both the intensity distribution and morphological characteristics of regions. In this paper, morphological component analysis is first introduced to decompose a mammogram into a piecewise-smooth component and a texture component. The former is utilized in our detection scheme as it effectively suppresses both structural noises and effects of blood vessels. Then, we propose two novel concentric layer criteria to detect different types of suspicious regions in a mammogram. The combination is evaluated based on the Digital Database for Screening Mammography, where 100 malignant cases and 50 benign cases are utilized. The sensitivity of the proposed scheme is 99% in malignant, 88% in benign, and 95.3% in all types of cases. The results show that the proposed detection scheme achieves satisfactory detection performance and preferable compromises between sensitivity and false positive rates.

Feasibility of biodegradable PLGA common bile duct stents: An in vitro and in vivo study

The current study investigates the feasibility of using a biodegradable polymeric stent in common bile duct (CBD) repair and reconstruction. Here, poly(l-lactide-co-glycolide) (PLGA, molar ratio LA/GA = 80/20) was processed into a circular tube- and dumbbell-shaped specimens to determine the in vitro degradation behavior in bile. The morphology, weight loss, and molecular weight changes were then investigated in conjunction with evaluations of the mechanical properties of the specimen. Circular tube-shaped PLGA stents with X-ray opacity were subsequently used in common bile duct exploration (CBDE) and primary suturing in canine models. Next, X-ray images of CBD stents in vivo were compared and levels of serum liver enzymes and a histological analysis were conducted after stent transplantation. The results showed that the PLGA stents exhibited the required biomedical properties and spontaneously disappeared from CBDs in 4-5 weeks. The degradation period and function match the requirements in repair and reconstruction of CBDs to support the duct, guide bile drainage, and reduce T-tube-related complications.

波动方程辛几何算法三维叠前深度偏移及其并行实现

Oil and scientific groups have been focusing on the 3D wave equation prestack depth migration since it can solve the complex problems of the geologic structure accurately and maintain the wave information, which is propitious to lithology imaging. The symplectic method was brought up by Feng Kang firstly in 1984 and became the hotspot of numerical computation study. It will be widely applied in many scientific field of necessity because of its great virtue in scientific sense. This paper combines the Symplectic method and the 3-D wave equation prestack depth migration to bring up an effectual numerical computation method of wave field extrapolatation technique under the scientific background mentioned above. At the base of deep analysis of computation method and the performance of PC cluster, a seismic prestack depth migration flow considering the virtue of both seismic migration method and Pc cluster has formatted. The software, named 3D Wave Equation Prestack Depth Migration of Symplectic Method, which is based on the flow, has been enrolled in the National Bureau of Copyright (No. 0013767). Dagang and Daqing Oil Field have now put it into use in the field data processing. In this paper, the one way wave equation operator is decompounded into a phase shift operator and a time shift operator and the correct item with high rank Symplectic method when approaching E exponent. After reviewing eliminating alias frequency of operator, computing the maximum angle of migration and the imaging condition, we present the test result of impulse response of the Symplectic method. Taking the imaging results of the SEG/EAGE salt and overthrust models for example and seeing about the imaging ability with complex geologic structure of our software system, the paper has discussed the effect of the selection of imaging parameters and the effectuation on the migration result of the seismic wavelet and compared the 2-D and 3-D prestack depth migration result of the salt mode. We also present the test result of impulse response with the overthrust model. The imaging result of the two international models indicates that the Symplectic method of 3-D prestack depth migration accommodates great transversal velocity variation and complex geologic structure. The huge computing cost is the key obstruction that 3-D prestack depth migration wave equation cannot be adopted by oil industry. After deep analysis of prestack depth migration flow and the character of PC cluster ,the paper put forward :i)parallel algorithms in shot and frequency domain of the common shot gather 3-D wave equation prestack migration; ii)the optimized setting scheme of breakpoint in field data processing; iii)dynamic and static load balance among the nodes of the PC cluster in the 3-D prestack depth migration. It has been proven that computation periods of the 3-D prestack depth migration imaging are greatly shortened given that adopting the computing method mentioned in the paper. In addition,considering the 3-D wave equation prestack depth migration flow in complex medium and examples of the field data processing, the paper put the emphasis on: i)seismic data relative preprocessing, ii) 2.5D prestack depth migration velocity analysis, iii)3D prestack depth migration. The result of field data processing shows satisfied application ability of the flow put forward in the paper.

Determination of sialic acids in the serum of cancer patients by capillary electrophoresis

A novel method for the determination of N-acetylneuraminic acid (NANA) and N-glycolylneuraminic acid (NGNA) was developed by using high-performance capillary electrophoresis (HPCE) with UV detection at 195 nm. NANA and NGNA were separated directly and analyzed without pre- or postcolumn derivation. The detection limit of NANA is 9.6 x 10(-6) mol L-1 and for mass 3.879 x 10(-14) mol (39 fmol). This method was applied for the determination of NANA in 30 normal human and 72 cancer patients. The results demonstrated that NANA in the sera of cancer patients increased significantly as compared with the normal human (P < 0.001). The new method is simple and sensitive, and is suitable for basic research and clinical application to malignant tumors.

Characteristic infrared spectroscopic patterns in the protein bands of human breast cancer tissue

Infrared (IR) spectra of normal, hyperplasia, fibroadenoma and carcinoma tissues of human breast obtained from 96 patients have been determined and analyzed statistically. Several spectral differences were detected in the frequency regions of N-H stretching, amide I, II and III bands: (1) the bands in the region 3000-3600cm-1 shifted to lower frequencies for the carcinomatous tissue; (2) the A(3300)/A(3075) absorbance ratio was significantly higher for the fibroadenoma than for the other types of tissues; (3) the frequency of the a-helix amide I band decreased for the malignant tissue, while the corresponding beta -sheet amide I band frequency increased; (4) the A(1657)/A(1635) and A(1553)/A(1540) absorbance ratios were the highest for fibroadenoma and carcinoma tissues; (5) the A(1680)/A(1657) absorbance ratio decreased significantly in the order of normal > hyperplasia > fibroadenoma > carcinoma; (6) the A(1651)/A(1545) absorbance ratio increased slightly for the fibroadenoma and the carcinoma tissues; (7) the bands at 1204 and 1278 cm(-1), assigned to the vibrational modes of the collagen, did not appear in the original spectra as resolved peaks and were distinctly stronger in the deconvoluted spectra of the carcinoma tissue and (8) the A(1657)/A(1204) and A(1657)/A(1278) absorbance ratios, both yielding information on the relative content of collagen, increased in the order of normal < hyperplasia < carcinoma < fibroadenoma. The said differences imply that the information is useful for the diagnosis of breast cancer and malignant breast abnormalities, and may serve as a basis for further studies on conformational changes in tissue proteins during carcinogenesis. (C) 2001 Elsevier Science B.V. All rights reserved.

Age-dependence of urinary normal and modified nucleosides in childhood as determined by reversed-phase high-performance liquid chromatography

Modified nucleosides have been characterized as tumor markers for a number of malignant diseases. In order to use these markers in children, the age-dependence of the nucleoside levels in healthy children has to be established and taken into account in diagnostic decisions. In this study, the levels of 12 normal and modified nucleosides in urine of 166 healthy children and adolescents with an age between 1 day and 19 years are determined by reversed-phase HPLC, and age-dependent reference ranges are defined. The urinary nucleoside concentrations are related to the creatinine concentrations, which allows the use of randomly collected urine samples. All nucleoside levels in urine of children decrease with age, most pronounced during the first 4 years of life, and the age-dependence of the reference values of the individual nucleosides can be approximated by a mathematical function y = b(0) + b(1) (1/x) with the regression coefficients b(0) and b(1), the nucleoside levels y and the age x between 1 year and 19 years. In the very young children, the shifts in the nucleoside concentrations are more differentiated. Starting with low levels on the first day of life, the concentrations of all studied nucleosides rise up to an age of 1-2 months, when they reach their absolute maximum for all age periods, and then decrease. (C) 2004 Elsevier B.V. All rights reserved.

Caratterizzazione proteomica di fluidi e tessuti in diverse condizioni fisio-patologiche

This thesis has been focused on the proteomic characterization of human saliva from donors of different ages, starting from birth up to adult age, and pediatric brain tumor tissues. The first study has been performed in order to compare the acid-insoluble fraction of saliva from preterm with at-term newborns and adults and establish if differences exist. In the second study medulloblastoma and pilocytic astrocytoma pediatric brain tumor extracts have been compared. In both studies 2- DE analysis was coupled with high resolution tandem mass spectrometry (MS/MS). The proteomic characterization of the acid-insoluble fractions of saliva from preterm newborns allowed to integrate data previously obtained on the acid-soluble fraction by HPLC-electrospray ionization (ESI)-mass spectrometry (MS), and to evidence several differences between preterm newborns, at-term newborns and adults. Spots differentially expressed between the three groups, according to image analysis of the gels, were submitted to in-gel tryptic digestion and the peptide mixture analyzed by high performance HPLC-ESI-MS/MS for their characterization. By this strategy, we identified three over-expressed proteins in atterm newborns with respect to preterm newborns and adults (BPI fold-containing family A member 1, two proteoforms of annexin A1, and keratin type 1 cytoskeletal 13), and several over-expressed proteins in adults (fatty acid-binding protein, S100A6, S100A7, two proteoforms of S100A9, several proteoforms of prolactin-inducible protein, Ig kappa chain, two proteoforms of cystatin SN, one proteoform of cystatin S and several proteoforms of α-amylase 1). Moreover, for the first time, it was possible to assign by MS/MS four spots of human saliva 2-DE, already detected by other authors, to different proteoforms of S100A9. The strategy applied used a sequential staining protocol to the 2-DE gels, first with Pro-Q Diamond, that allows specific detection of phosphoproteins, and successively with total protein SYPRO Ruby stain. In the second study, proteomic analysis of two pediatric brain tumor tissues pointed out differences between medulloblastoma, the prevalent malignant tumor in childhood, and pilocytic astrocytoma, the most common, that only rarely shows a malignant progression. Due to the limited availability of bioptic tissue, the study was performed on pooled tumor tissues, and was focused on acid-insoluble fraction to integrate the characterization performed by a group of colleagues in Rome on the acid-soluble fraction by high performance HPLC-ESI-MS/MS. The results indicated that the two tumors exhibit different proteomic profiles and evidenced interesting differential expression of several proteins. Among them, peroxiredoxin- 1, peptidyl-prolyl cis–trans isomerase A, heterogeneous nuclear ribonucleoproteins A2/B1, mitochondrial isoform of malate dehydrogenase, nucleoside diphosphate kinase A, glutathione S-transferase P and fructose bisphosphate aldolase A resulted significantly over-expressed in medulloblastoma while glial fibrillary acidic protein, serotransferrin, α crystallin B chain, ferritin light chain, annexin A5, fatty acid-binding protein (brain), sorcin and apolipoprotein A-I resulted significantly over-expressed in pilocytic astrocytoma. In conclusion, the work done allowed to evidence the usefulness of using an integrated bottom-up/top-down approach, based on 2-DE-MS analysis and high performance MS in order to obtain a complete characterization of the proteome under investigation, revealing and identifying, not only peptides and small proteins, but also proteins with higher MW, that often it is not possible to identify by using exclusively a top-down ESI-MS approach.

Confidentiality issues in information systems in social care

Cooper, J. & Urquhart, C. (2004). Confidentiality issues in information systems in social care. In K. Grant, D.A. Edgar & M. Jordan (Eds.), Reflections on the past, making sense of today and predicting the future of information systems, 9th annual UKAIS (UK Academy of Information Systems) conference proceedings, Annual conference, 5-7 May 2004, Glasgow Caledonian University (CD-ROM). Glasgow: Glasgow Caledonian University for UKAIS Sponsorship: AHRC

Sinusite odontogénica

Monografia apresentada à Universidade Fernando Pessoa para obtenção do grau de Licenciada em Medicina Dentária.

Via de sinalização mTOR e efeito dos seus inibidores no tratamento do cancro

Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências Farmacêuticas

Evolução na abordagem Fármaco-terapêutica da úlcera péptica

Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências Farmacêuticas

Úlcera péptica

Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências Farmacêuticas