Microalgae as a source of bioactive molecules – experience from cyanophyte research

Detrimental and beneficial properties of prokaryoticand eukaryotic microalgae may be qualifications givingthem posibillities for their biotechnologicalutilization. Phycotoxins and related products mayserve as material for useful drugs. Cyanotoxins arean example. Bioassay screening methods are used todetect specific biological activity (e.g. antibioticeffects). A study demonstrating antibacterialproperties among cyanophytes showed that these effectswere caused by substances produced by both toxigenicand non-toxigenic strains. Differences inbiosynthetic activity are influenced by the type ofclones and by the culture conditions (genetic andbiochemical variation). Experience of recentscreening (1997–1998) of compounds from cyanophytes –including 25 species from 14 genera – display thediscovery of more than 30 different antibioticsubstances. The further isolation of newpharmaceuticals from natural resources is becomingdifficult, if not uncommon species of producerorganisms are taken into consideration.     

Charles McLean Fraser (1872–1946) – his contributions to hydroid research and to the development of fisheries biology and academia in British Columbia

Hydrobiologia - Charles McLean Fraser (1872–1946) is best remembered for his work on hydroids, but he was also involved in a much broader range of activities during the development of marine...     

Isatis tinctoria – From the rediscovery of an ancient medicinal plant towards a novel anti-inflammatory phytopharmaceutical

An account on the reinvestigation of the old dye and medicinal plant Isatis tinctoria as an anti-inflammatory and current research on the active principles in woad is given. In a broad-based screening, a dichloromethane extract from the leaves displayed significant activities on several clinically relevant targets of inflammation. The cyclooxygenase-2 inhibitory principle was identified with the aid of HPLC-based activity profiling as the alkaloid tryptanthrin. In cell based assays, tryptanthrin strongly inhibited eicosanoid synthesis catalyzed by cyclooxygenase-2 and 5-lipoxygenase. A supercritical carbon dioxide extraction process was developed to replace the dichloromethane extract. Dichloromethane and carbon dioxide extracts showed in vivo anti-inflammatory activity in topical and oral application. With the aid of electrospray ionization liquid chromatography-mass spectrometry coupled skin microdialysis, tryptanthrin was found to penetrate the skin. The penetration from the extract was better than for the pure alkaloid. A screening of 67 woad samples of different geographic origin revealed up to 30-fold differences in tryptanthrin content in leaves. This revised version was published online in June 2006 with corrections to the Cover Date.     

The promise of e-Health – a Canadian perspective

Canadians value their health care system above any other social program. Canada's system of health care faces significant financial and population pressures, relating to cost, access, quality, accountability, and the integration of information and communication technologies (ICTs). The health-system also faces certain unique challenges that include care delivery within a highly decentralised system of financing and accountability, and care delivery to a significant portion of the population sparsely distributed across a landmass of 10 million square kilometres, in areas of extreme climatic conditions. All of these challenges are significant catalysts in the development of technologies that aim to significantly mitigate or eliminate these selfsame challenges.The system is undergoing widespread review, nationally, and within each province and territory, where the bulk of care provision is financed and managed. The challenges are being addressed by national, regional and provincial initiatives in the public, private and not-for-profit sectors.The promise of e-Health lies in the manner and degree to which it can mitigate or resolve these challenges to the health system and build on advancements in ICTs supporting the development of a health infostructure. Canada is actively developing and implementing technological solutions to deliver health information and health care services across the country. These solutions, while exciting and promising, also present new challenges, particularly in regard to acceptable standards, choice of technologies, overcoming traditional jurisdictional boundaries, up-front investment, and privacy and confidentially.Many organisations and governments are working to address these challenges. The Canadian Institute for Health Information (CIHI) will play an increasingly significant role in these initiatives, as the management of health information becomes a more crucial factor in the successful delivery of health care services in the new millennium.     

Economics,human biology and inequality: A review of “puzzles” and recent contributions from a Deatonian perspective

The Nobel laureate Angus Deaton concentrated his work on puzzling developments and phenomena in economics. Puzzles are exciting elements in economics, because readers feel challenged by the question of how they can be solved. Among the puzzles analyzed by Deaton are: (1) Mortality increase of white, U.S. non-Hispanic men (2000 to today); (2) Why are height and income sometimes closely correlated, but not always?; (3) Height inequality among males and females; and (4) The Indian puzzle of declining consumption of calories during overall expenditure growth.This article reviews these “puzzles” and the main insights that Deaton derived from their discussion insofar as they pertain to the biological aspects of human development. I will focus on the field of this journal, Economics and Human Biology, in which Deaton has been very active over the last two decades. I will also document some of the responses by other scholars and their contributions to these puzzles, as they relate to the field of economics and human biology.     

The cave bear’s hibernation: reconstructing the physiology and behaviour of an extinct animal

Abstract

When studying an extinct species such as the cave bear (Ursus spelaeus ROSENMÜLLER 1794), it is possible to apply a variety of molecular biology techniques such as the study of stable isotopes or mitochondrial DNA (mDNA) to infer patterns of behaviour or physiology that would otherwise remain concealed. Throughout Europe and along time, differences in the isotopic values (δ¹³C and δ¹⁵N) of cave bears arise from environmental differences and the Pleistocene climatic evolution. The climate determines the hibernation length, during which the cave bears undergo a particular physiology that can be related to an increase in δ¹⁵N during climate cooling. In order to verify whether hibernation affected the isotopic values, we compared cave bears in different ontogenetic stages. The results show that perinatal values reflect the values for mothers during hibernation, while juveniles show differences in maternal investment. A previous study in the literature based on complete mitochondrial DNA sequences of several individuals collected from closely situated caves showed that each cave housed, almost exclusively, a single lineage of haplotypes. This pattern suggests extreme fidelity to the birth site, or homing behaviour, and that cave bears formed stable maternal social groups, at least for the purpose of hibernation. Studies of this type offer unexpected data on the palaeobiology of this extinct animal.     

Can yeast systems biology contribute to the understanding of human disease?

Saccharomyces cerevisiae is a unicellular eukaryal microorganism that has traditionally been regarded either as a model system for investigating cellular physiology or as a cell factory for biotechnological use, for example for the production of fuels and commodity chemicals such as lactate or pharmaceuticals, including human insulin and HPV vaccines. Systems biology has recently gained momentum and has successfully been used for mapping complex regulatory networks and resolving the dynamics of signal transduction pathways. So far, yeast systems biology has mainly focused on the development of new methods and concepts. There are also some examples of the application of yeast systems biology for improving biotechnological processes. We discuss here how yeast systems biology could be used in elucidating fundamental cellular principles such as those relevant for the study of molecular mechanisms underlying complex human diseases, including the metabolic syndrome and ageing.     

The world from a cat’s perspective – statistics of natural videos

The mammalian visual system is one of the most intensively investigated sensory systems. However, our knowledge of the typical input it is operating on is surprisingly limited. To address this issue, we seek to learn about the natural visual environment and the world as seen by a cat. With a CCD camera attached to their head, cats explore several outdoor environments and videos of natural stimuli are recorded from the animals perspective. The statistical analysis of these videos reveals several remarkable properties. First, we find an anisotropy of oriented contours with an enhanced occurrence of horizontal orientations, earlier described in the oblique effect as a predominance of the two cardinal orientations. Second, contrast is not elevated in the center of the images, suggesting different mechanisms of fixation point selection as compared to humans. Third, analyzing a sequence of images we find that the precise position of contours varies faster than their orientation. Finally, collinear contours prevail over parallel shifted contours, matching recent physiological and anatomical results. These findings demonstrate the rich structure of natural visual stimuli and its direct relation to extensively studied anatomical and physiological issues.     

Using research projects and qualitative conceptual modeling to increase novice scientists’ understanding of ecological complexity

A new program, Teaching Ecological Complexity, is working to develop a heightened capacity for systems thinking among high school biology and environmental sciences teachers. During a 2-week field-based course, the teachers use qualitative conceptual modeling, participate in all stages of field experimentation, and formulate plans to teach field research with their own classes. Qualitative conceptual modeling was found to be useful in revealing the underlying perceptions of ecosystem functioning for these novice scientists. Preliminary results showed improvement in their ability to recognize and apply some of the attributes of complex ecosystem: non-linear feedback loops, hierarchical organization, patterns illustrating the spatial arrangements of species diversity. In addition to using models, teachers used peer-learning techniques. Collegial discussions about what they understood at particular points in time were useful in improving their understanding of ecosystem phenomenon.     

Establishing health benefits of bioactive food components: a basic research scientist’s perspective

1. Download : Download high-res image (117KB)
2. Download : Download full-size image

     

From ‘ecologist’ to ‘conceptual ecologist’: the utility of the conceptual ecology analogy for teachers of biology

This paper advocates the application of established teaching models to the professional development of biology teachers. This is achieved by using the analogy of conceptual ecologies, made explicit through concept mapping. The approach is designed to support teachers' developing understanding of pupils' conceptual change by using familiar terminology and biological analogies. Monitoring of students' understanding at an ecosystemic level may also help distinguish between instances of conceptual change and contextual switching (described here with reference to photosynthesis).     

From molecules to the biosphere: Nikolai V. Timoféeff-Ressovsky’s (1900–1981) research program within a totalitarian landscape

Nikolai Vladimirovich Timoféeff-Ressovsky was one of the key figures in the Synthetic Theory of Evolution. Living and researching under what was arguably the two most powerful and cruel totalitarian regimes in human history, the Third Reich and the Soviet Union, Timoféeff-Ressovsky succeeded in developing an ambitious research program aiming to explain evolution on all major levels, from the molecular-genetic, the populational, and the biogeocenotic to the level of the entire Biosphere. Yet his scientific biography remains largely unwritten and his role under totalitarianism, especially in Nazi Germany, remains highly controversial. Here we approach the problem of his hypothetical cooperation with Nazi authorities examining both the crucial episodes of his biography and summarizing the development of his research program. We conclude that the key decisions he made reflected the specificity of his research program that was focused on the fundamental questions of evolutionary biology.     

Genome-scale modeling of human metabolism – a systems biology approach

Altered metabolism is linked to the appearance of various human diseases and a better understanding of disease-associated metabolic changes may lead to the identification of novel prognostic biomarkers and the development of new therapies. Genome-scale metabolic models (GEMs) have been employed for studying human metabolism in a systematic manner, as well as for understanding complex human diseases. In the past decade, such metabolic models – one of the fundamental aspects of systems biology – have started contributing to the understanding of the mechanistic relationship between genotype and phenotype. In this review, we focus on the construction of the Human Metabolic Reaction database, the generation of healthy cell type- and cancer-specific GEMs using different procedures, and the potential applications of these developments in the study of human metabolism and in the identification of metabolic changes associated with various disorders. We further examine how in silico genome-scale reconstructions can be employed to simulate metabolic flux distributions and how high-throughput omics data can be analyzed in a context-dependent fashion. Insights yielded from this mechanistic modeling approach can be used for identifying new therapeutic agents and drug targets as well as for the discovery of novel biomarkers. Finally, recent advancements in genome-scale modeling and the future challenge of developing a model of whole-body metabolism are presented. The emergent contribution of GEMs to personalized and translational medicine is also discussed.     

Biocatalytic asymmetric amination of carbonyl functional groups – a synthetic biology approach to organic chemistry

Transaminases catalyze amino transfer reactions from amino donors such as amino acids or amines to keto acids or ketones to give chiral amino acid or amines in optically pure form. α-Amino acid dehydrogenases catalyze the asymmetric reductive amination of α-keto acids using ammonia as amino donor to furnish L -amino acids. The distinct features and synthetic application of these two enzymes are reviewed in an effort to illustrate their promising and challenging aspects in serving as approaches to the direct asymmetric synthesis of optically pure amines from the corresponding keto compounds, a formidable problem in organic chemistry.     

Responding to the threat of bioterrorism: a microbial ecology perspective – the case of anthrax

Anthrax is a disease of herbivores caused by the gram-positive bacterium Bacillus anthracis. It can affect cattle, sheep, swine, horses and various species of wildlife. The routes for the spread among wildlife are reviewed. There are three kinds of human anthrax – inhalation, cutaneous, and intestinal anthrax – which differ in their routes of infection and outcomes. In the United States, confirmation of cases is made by the isolation of B. anthracis and by biochemical tests. Vaccination is not recommended for the general public; civilians who should be vaccinated include those who, in their work places, come in contact with products potentially contaminated with B. anthracis spores, and people engaged in research or diagnostic activities. After September 11, 2001, there were bioterrorism anthrax attacks in the United States: anthrax-laced letters sent to multiple locations were the source of infectious B. anthracis. The US Postal Service issued recommendations to prevent the danger of hazardous exposure to the bacterium. B. anthracis spores can spread easily and persist for very long times, which makes decontamination of buildings very difficult. Early detection, rapid diagnosis, and well-coordinated public health response are the key to minimizing casualties. The US Government is seeking new ways to deter bioterrorism, including a tighter control of research on infectious agents, even though pathogens such as B. anthracis are widely spread in nature and easy to grow. It is necessary to define the boundary between defensive and offensive biological weapons research. Deterring bioterrorism should not restrict critical scientific research. Electronic Publication     

Review: Application of biotechnology to forestry – molecular biology of conifers

Genetic improvement in plantation forestry relies significantly on conventional breeding techniques which have been used extensively to improve various characteristics in forest trees such as growth and form, volume yield, resistance to pathogens and quality of the end product. This review concentrates on molecular techniques which have been used successfully in agriculture and which have more recently become available to improve further characteristics of forest trees and introduce new traits which are currently not available in the breeding population.