The use of functional human tissues in drug development

Fresh, functional human tissues have long been considered the closest possible model of human in vivo function and can be used to measure a wide range of pharmacological responses. Despite this, relatively little drug development is conducted using fresh human tissue because of the logistical and ethical difficulties surrounding the availability of tissue and practicalities of experimental work. Most tests of drug activity require a living test system comprising cells, tissues or whole organisms. In some instances, “living” (fresh) human tissues have the potential to reduce or replace animal tests through superior prediction of drug safety and efficacy. Before functional human tissue tests become a routine part of drug development, two factors must co-exist. Firstly, organisations such as Biopta must continue to create compelling evidence that human tissues are more predictive than alternative models; such evidence will drive demand from the pharmaceutical industry for human tissue-based tests. Secondly, the vast number of tissues and organs residual to surgery or unsuitable for transplant must be routinely consented for medical research and made available to all researchers in an equitable and timely manner. This requires a concerted effort throughout the NHS and consistent demand as well as financial support from researchers, particularly within industry. It is our view that the next 5–10 years will generate compelling evidence of the value of functional human tissue-based tests and recognition that more efficient use of residual or non-transplantable tissues and organs is an urgent priority for the development of new medicines.     

Human research tissue banks: the ATRA Project for establishing a human research tissue bank in switzerland

A large number of experiments in biomedical research are carried out on tissues, but, even though the results should be applicable to humans, these tissues are mainly of animal origin. The difficulty encountered in obtaining human organs and tissues is an acknowledged problem: not enough human tissues are available to meet research needs. We are introducing the ATRA Project, with the purpose of supporting progress in biomedical research in Switzerland through the establishment of one or more human tissue banks, which will be able to find, treat, preserve and supply human material. Where similar projects have already been launched, concerns have been expressed that donation for research purposes might compete with donation for transplantation, but most organs and tissues are in any case non-transplantable. Surplus surgical tissue is considered "sanitary waste", and must be treated according to specific regulations for collection, packaging, transport, treatment and disposal. A human tissue bank would not only abate the costs of treating sanitary waste, but would actually turn what is now considered waste into a resource which could be used to save human and animal lives.     

Development of a transplantation transmission sentinel network to improve safety and traceability of organ and tissues

The US lags behind other developed countries in creating a system to monitor disease transmission and other complications from human allograft use, despite a pressing need. The risks of transmission are amplified in transplantation, since at least 8 organs and more than 100 tissues can be recovered from a single common organ and tissue donor. Moreover, since many allografts collected in the US are distributed internationally, tissue safety is a global concern. In June 2005, participants of a US government-sponsored workshop concluded that a communication network for the tracking and reporting of disease transmissions for tissues and organs was critically needed. The United Network for Organ Sharing (UNOS) entered into a cooperative agreement with the Centers for Disease Control and Prevention (CDC) in 2006 to develop a system prototype. Over the following 3 years, the Transplantation Transmission Sentinel Network (TTSN) was developed and piloted with the participation of organ procurement organizations, tissue banks and transplant centers. The prototype centered around three elements of data entry: (1) donation, (2) tissue implantation, and (3) adverse event. The pilot proved that a system can be built and operated successfully, but also suggested that users may be hesitant to report adverse events. CDC has requested further input on scope and cost to build a transplant surveillance infrastructure for a fully functional national system. For tissues however, in contrast to organs, tracking from recovery to implantation will be necessary before a system is operable, requiring common identifiers and nomenclature. Until a US sentinel network is operational, future transmission events that are preventable may result nationally and globally due to its absence.     

Efficacy and safety of new medicines: a human focus

The introduction of safe and effective new medicines is proving ever more difficult, a problem arguably due at least in part to over-reliance on experimental animal-based test systems. In light of the increasing awareness of the lack of predictiveness of such non-human approaches, the necessity to focus on human-based test methods is clear. There has been considerable progress in human in vivo (microdosing) and in silico approaches, primarily to identify ADMET issues, however, in vitro functional studies using human tissues are receiving inadequate attention. The potential scope of human tissue-based research is considerable, but much methodological development is required, which necessitates an increased willingness on the part of the Pharma industry to support it. This approach also requires considerably improved access to the cells and tissues themselves. While current acquisition is almost exclusively from surgery and post mortem, the range of tissue types, the quantity, quality and frequency of supply will remain inadequate to support human tissue as a key component of pre-clinical efficacy and safety testing. Additional routine access to non-transplantable tissues from organ donors for research purposes would be of inestimable value, but in order to realise this, true collaboration will be required between NHS, the Pharma and biotech industries, and the general public.     

Biobanking residual tissues

Health-care research relies largely on human materials stored in highly specialised biorepositories. Medical translational research on tissues can be performed using a variety of resources in distinct situations. The best known is the secondary use of pathology archives where paraffin-embedded tissues are stored for diagnostic reasons. Another is collecting and storing frozen material obtained from leftover surgical diagnosis. Such residual tissues can either be used directly in research projects or used in the context of a clinical trial with new interventional medicinal products. The latter can make the regulations governing the use of these materials for medical research much more complicated. The use of residual materials is very distinct from biobanking projects for which tissue is specifically collected. This article describes the consequences of using residual human material from different sources in distinct situations and why signed informed consent is not always the preferred choice of individual countries regarding the use of residual material. In addition, signed informed consent is overdone when using residual tissues in medical research. We maintain that the opt-out system is a balanced choice if certain requirements are met, relating to sufficient transparency about using residual tissue for research, the purpose of such research and to the confidentiality of the data used in that research. Finally, the international exchange of samples can be based on the laws and regulations of the countries of origin. Respecting these form the basis of what can and cannot be done in the country where the research on the samples is being performed.     

Control, bioenergetics, and adaptation in health and disease: noninvasive biochemistry from nuclear magnetic resonance.

The noninvasive study of cellular homeostasis, control, and energetics in tissues and organs within intact living systems is now possible. Nuclear magnetic resonance (NMR) spectroscopy in vivo provides information about key metabolites, reaction rates, the control of ionic equilibria and fluxes (including that of H+), and molecular diffusion and motions within the cell. When phosphorus (31P) is measured, the processes associated with the production and utilization of adenosine triphosphate (ATP) are followed. Using 13C for measurement, the pathways and fluxes in the synthesis and degradation of sugars (e.g., glycogen), amino acids, etc., can be observed. Intracellular, cytoplasmic pH (H+ concentration) can be determined from the 31P-NMR spectrum of organs and cells whereas Na+ and K+ (or its congener Rb+) are directly measurable by NMR. All these can be observed in physiological situations in almost any organism in the animal or plant kingdom. The bioenergetics of locust muscle in flight is as readily measured as that in human muscle in health, training, and disease. When spatially resolved, the NMR spectra can provide metabolic maps of the human heart, brain, and other organs. Thus we can now directly delineate the biochemical basis of human diseases.     

Global gene expression during the human organogenesis: from transcription profiles to function predictions

Human embryogenesis includes an integrated set of complex yet coordinated development of different organs and tissues, which is regulated by the spatiotemporal expression of many genes. Deciphering the gene regulation profile is essential for understanding the molecular basis of human embryo development. While molecular and genetic studies in mouse have served as a valuable tool to understand mammalian development, significant differences exists in human and mouse development at morphological and genomic levels. Thus it is important to carry out research directly on human embryonic development. Here we will review some recent studies on gene regulation during human embryogenesis with particular focus on the period of organogenesis, which had not been well studied previously. We will highlight a gene expression database of human embryos from the 4(th) to the 9(th) week. The analysis of gene regulation during this period reveals that genes functioning in a given developmental process tend to be coordinately regulated during human embryogenesis. This feature allows us to use this database to identify new genes important for a particular developmental process/pathway and deduce the potential function of a novel gene during organogenesis. Such a gene expression atlas should serve as an important resource for molecular study of human development and pathogenesis.     

激光捕获显微切割在肿瘤多组学研究中的应用进展

当今社会,肿瘤因其高发病率和高死亡率成为威胁人类健康的重要疾病,研究者们对其发病机制及治疗手段的研究和探索也在不断深入。随着单细胞多组学测序技术的发展,肿瘤组织的异质性问题逐渐被研究人员所认识。为了解决这一问题,激光捕获显微切割（laser capture microdissection,LCM）技术应运而生。LCM技术是一种在显微镜直视下从器官或组织中准确获取某种特定的细胞群或单个细胞的样本收集技术。LCM技术结合多种分子生物学手段可以对异质性组织进行多组学研究,丰富了现有的肿瘤蛋白质组学、基因组学以及转录组学图谱,因此,LCM技术成为研究特异性表达及分子机制的有力工具,在肿瘤学领域得到广泛应用。基于此,对LCM的原理、优势及其在肿瘤多组学研究中的应用进行了综述,并对其未来可能的发展方向进行了展望,以期为肿瘤的研究和治疗提供新的思路。     

选择性微电极在植物生理学研究中的应用

选择性微电极技术是一种不仅能直接测定活的生物细胞或细胞器内的离子或分子活度,而且能对活的生物相邻的位置、功能和代谢速率可能不同的特定微区细胞表面的离子或分子流（flux）分别测定的电生理方法。具有操作简便、实时、非损伤性（测定离子或分子流）、灵敏度高（可达10^-12moles cm^-2s^-1）等优点。因为它是用微型化（尖端直径为0.5-5μm）的离子或分子选择性电极直接对准样品测定,不同于其他化学测定需取样品,所以能连续测定和自动监测,具有广阔的应用前景。该文阐述了选择性微电极测定原理,总结了选择性微电极技术在植物生理学研究中的应用进展,并展望了其发展前景。     

Potential of human embryonic stem cells in regenerative medicine

Stem cells can give rise to more stem cells or differentiate into more specialized cells. In the last 5 years not only have researchers succeeded in isolating human embryonic stem (hES) cell lines but also in identifying adult stem cells with possible pluripotent differentiation capacity. The shortage of donor organs or tissues for regenerative medicine has further stimulated research into the capacity of stem cells to differentiate into different cells and their use in replacement therapy in diseases such as Parkinson's, diabetes, rheumatoid arthritis and myocardial infarction. Current problems and recent progress with respect to hES cells and their potential use for clinical applications will be discussed. The potential of adult stem cells for differentiation and tissue repair is reviewed elsewhere.     

Studies onSargassum

Summary Cytological comparisons of homologous tissues in blades and stipes by stereological analysis have shown differences exist between blade and stipe organs inSargassum. Based on measurements of total thylakoid and cristae membrane surface areas in these organs blades were found to contain 61% more thylakoid membrane surface and 65% more cristae membrane than stipes on a per unit volume basis. Assuming photosynthesis and respiration are directly related to the surface area of the internal membranes in the respective organelles it is possible to predict that blades will have a 61% greater photosynthetic and a 65% greater respiratory potential. Photosynthetic and respiratory rates for blades and stipes were determined manometrically and show a 62% greater photosynthetic and 59% greater respiratory rates for the blade tissues agreeing very well with predicted values.Present evidence indicates that photosynthetic and respiratory rate differences observed in the blades and stipes inSargassum are the result of increased membrane surface areas in the larger cells of the tissues which make up the blade. The basic cell structure,i.e., the percent volume of cell cytoplasm occupied by each organelle, is similar in homologous tissues of both organs regardless of cell size. Therefore physiological differences between the two organs are primarily due to changes in cell size and not in basic cell construction. This provides an interesting mechanism for producing physiological differences without changing basic cell structure in the organs of this plant.     

干细胞与组织工程

随着生物材料、生物反应器设计及对机体发育和创伤修复机制的深入理解,在体外构建用于修复替代人体丧失功能的组织器官这一人类理想,已发展成一门独立且蓬勃发展的学科——组织工程学（Tissue Engineering）。组织工程学是一个多学科交叉的新兴领域,至少涉及生命科学、医学及工程学等三个学科。种子细胞、支架材料和诱导信号是组织工程学的三个基本要素。目前种子细胞是制约组织工程发展的一个主要瓶颈。干细胞生物学的发展使人们看到了打破这个瓶颈的可能。干细胞体外扩增及定向分化的技术发展,及对其增殖和诱导分化机制的深入理解,使工程化组织可以获得理想的基本功能单位,使其应用于临床成为可能。     

Human lung tissue engineering: a critical tool for safer medicines

In the field of human tissue-engineering, there has been a strong focus on the clinical aspects of the technology, i.e. repair, replace and enhance a given tissue/organ. However, much wider applications for tissue engineering (TE) exist outside of the clinic that are often not recognised, and include engineering more relevant models than animals in basic research and safety testing. Traditionally, research is initially conducted on animals or cell lines, both of which have their limitations. With regard to cell lines, they are usually transformed to enable indefinite proliferation. These immortalised cell lines provide the researcher with an almost limitless source of material. However, the pertinence of the data produced is now under scrutiny, with the suggestion that some historical cell lines may not be the cell type originally reported. By engineering normal, biomimetic (i.e. life-mimicking), human tissues with defined physiology (i.e. human tissue equivalents), the complex 3-dimensional (3-D) tissue/organ physiology is captured in vitro, providing the opportunity to directly replace the use of animals in research/testing with more relevant systems. Therefore, it is imperative that testing strategies using organotypic models are developed that can address the limitations of current animal and cellular models and thus improve drug development, enabling faster delivery of drugs which are safer, more effective and have fewer side effects in humans.     

Kindlin-2 expression in adult tissues correlates with their embryonic origins

Kindlin-2 functions in the maintenance of homeostasis and in human diseases. This study investigated the interrelationship between Kindlin-2 expression in tissues and the corresponding germ layers from which these tissues originated. Kindlin-2 expression was examined in normal adult human organs and human cancer tissues by immunohistochemical analyses. Analysis of Kindlin-2 mRNA levels in adult human organs in the Oncomine dataset revealed Kindlin-2 is highly expressed in mesoderm-derived organs. However, Kindlin-2 was negative or weakly expressed in endoderm/ectoderm-derived organs. Interestingly, the abnormal expression of Kindlin-2 was observed in a variety of human cancers. In agreement with its expression profile in humans, Kindlin-2 was also highly expressed in mesoderm-derived organs in mouse embryos with the exception of strong Kindlin-2 expression in ectoderm-derived spinal cord and ganglia, tissues that are highly mobile during embryonic development. Importantly, we demonstrated the expression level of Kindlin-2 in adult organs correlated with their embryonic dermal origins and deregulation of Kindlin-2 in tissues is associated with tumor progression. This finding will help us understand the dual role of Kindlin-2 in the regulation of tumor progression and embryonic development.     

Reflections on the reproductive sciences in agriculture in the UK and US, ca. 1900-2000+

This paper provides a brief comparative overview of the development of the reproductive sciences especially in agriculture in the UK and the US. It begins with the establishment by F. H. A. Marshall in 1910 of the boundaries that framed the reproductive sciences as distinct from genetics and embryology. It then examines how and where the reproductive sciences were taken up in agricultural research settings, focusing on the differential development of US and UK institutions. The reproductive sciences were also pursued in medical and biological settings, and I discuss how the intersections among all three allowed the circulation of both ideas and scientists' careers. Across the twentieth century, scientific leadership in the reproductive sciences alternated between the UK and US, and these patterns are elucidated. I conclude with thoughts on future research that might emphasize the elaboration of industrialization processes in agriculture and new capacities to transform both reproductive processes and their products--life itself--as biopower comes to be more ambitiously understood as extending across all species.     

The Pig PeptideAtlas: A resource for systems biology in animal production and biomedicine

Biological research of Sus scrofa, the domestic pig, is of immediate relevance for food production sciences, and for developing pig as a model organism for human biomedical research. Publicly available data repositories play a fundamental role for all biological sciences, and protein data repositories are in particular essential for the successful development of new proteomic methods. Cumulative proteome data repositories, including the PeptideAtlas, provide the means for targeted proteomics, system‐wide observations, and cross‐species observational studies, but pigs have so far been underrepresented in existing repositories. We here present a significantly improved build of the Pig PeptideAtlas, which includes pig proteome data from 25 tissues and three body fluid types mapped to 7139 canonical proteins. The content of the Pig PeptideAtlas reflects actively ongoing research within the veterinary proteomics domain, and this article demonstrates how the expression of isoform‐unique peptides can be observed across distinct tissues and body fluids. The Pig PeptideAtlas is a unique resource for use in animal proteome research, particularly biomarker discovery and for preliminary design of SRM assays, which are equally important for progress in research that supports farm animal production and veterinary health, as for developing pig models with relevance to human health research.     

Computed tomography in paleopathology: Technique and case study

With the development of computed tomography, soft tissues and foreign body collections are distinguished with remarkable resolution. This distinction is particularly useful when examining desiccated human remains, both in construction of research strategies and when invasive procedures (i.e., traditional autopsies, needle biopsies, etc.) are not possible. Though the organs differ markedly from living tissue, it is possible to distinguish major organs with some certainty. One case study exhibited three separate pathological conditions which were not demonstrated with traditional radiological procedures.     

An evaluation of tyramide signal amplification and archived fixed and frozen tissue in microarray gene expression analysis

Archival formalin-fixed, paraffin-embedded and ethanol-fixed tissues represent a potentially invaluable resource for gene expression analysis, as they are the most widely available material for studies of human disease. Little data are available evaluating whether RNA obtained from fixed (archival) tissues could produce reliable and reproducible microarray expression data. Here we compare the use of RNA isolated from human archival tissues fixed in ethanol and formalin to frozen tissue in cDNA microarray experiments. Since an additional factor that can limit the utility of archival tissue is the often small quantities available, we also evaluate the use of the tyramide signal amplification method (TSA), which allows the use of small amounts of RNA. Detailed analysis indicates that TSA provides a consistent and reproducible signal amplification method for cDNA microarray analysis, across both arrays and the genes tested. Analysis of this method also highlights the importance of performing non-linear channel normalization and dye switching. Furthermore, archived, fixed specimens can perform well, but not surprisingly, produce more variable results than frozen tissues. Consistent results are more easily obtainable using ethanol-fixed tissues, whereas formalin-fixed tissue does not typically provide a useful substrate for cDNA synthesis and labeling.     

城市可持续发展新型定量研究方法进展

城市体现了集约化的发展方式,以仅占陆地3%的面积承载了世界一多半的人口,因此城市是人类社会可持续发展的主阵地,城市可持续发展是区域可持续发展的重要实践。研究试图从可持续发展的基本内涵着手,聚焦于城市尺度的研究,梳理了相关理论和概念演变历程,着重对新型定量方法——评价指标体系法、复杂系统建模、资源环境可持续性探索等进行综述。研究发现指标体系法常用于传统的城市可持续发展评估,大多是针对表象的分析,隔离了系统内部的组织关联,对系统机理探索不够。资源环境对人类社会的发展起到基础支撑作用,从资源环境可持续性出发研究可持续发展诞生了一些较为创新的方法,但研究集中在描述人类对自然的压力和影响,而对于自然对人类的反馈以及人对自然的积极改造探索不足,也很难直接表达系统整体的可持续性。弹性思维和复杂系统科学近年来被多次用于解释城市运行的灰箱模型,但研究稍浅。研究提出可将弹性思维和复杂系统科学结合起来,借助数据科学和计算科学的新兴方法,分析城市的可持续发展,深入探索可持续性的科学表达和深层机理,为解决复杂的城市问题提供科学指导,为城市可持续发展提供理论依据。