Editorial – Clonal plants and environmental heterogeneity – space, time and scale

The fifth Clonal Plant Workshop entitled 'Clonal plants and environmental heterogeneity – space, time and scale' was held at the University of Wales, Bangor, from the 9th to the 14th September 1997. The workshops began in 1988, when a small group of plant scientists with different backgrounds met in the Netherlands to discuss plant clonality. This meeting was followed by workshops in 1990, 1992 and 1995 in Sweden, the Czech Republic and Hungary, respectively. The purpose of the Bangor meeting was to continue to integrate knowledge from a wide range of biological disciplines to attempt a better understanding of clonal plants in the context of the heterogeneous environments in which they occur. This special issue is a collection of a number of the presentations at the Bangor workshop. The effects of spatial and temporal environmental heterogeneity on individuals, populations and communities are, of course, diverse, and this collection of papers is not intended to provide a synthesis of the ecological consequences of environmental heterogeneity. Rather, this special issue more accurately reflects progress in various areas of clonal plant research including population dynamics of ramets and genets, mathematical modelling and molecular techniques. We wish to thank all participants of the workshop for their contribution and trust that they found the meeting as stimulating and enjoyable as we did. We are indebted to the authors and the many referees for their friendly cooperation and to Plant Ecology for publishing the proceedings. We also gratefully acknowledge the financial support of the following that made the workshop possible: The British Ecological Society, The Tansley Fund of the New Phytologist Trust, The Countryside Council for Wales, The Institute of Terrestrial Ecology (Bangor) and Skye Instruments Ltd, Wales.     

Enzymes in jasmonate biosynthesis – Structure,function, regulation

Jasmonates are a growing class of lipid-derived signaling molecules with diverse functions ranging from the initiation of biotic and abiotic stress responses to the regulation of plant growth and development. Jasmonate biosynthesis originates from polyunsaturated fatty acids in chloroplast membranes. In a first lipoxygenase-catalyzed reaction molecular oxygen is introduced to yield their 13-hydroperoxy derivatives. These fatty acid hydroperoxides are converted by allene oxide synthase and allene oxide cyclase to 12-oxophytodienoic acid (OPDA) and dinor-OPDA, i.e. the first cyclic intermediates of the pathway. In the subsequent step, the characteristic cyclopentanone ring structure of jasmonates is established by OPDA reductase. Until recently, jasmonic acid has been viewed as the end product of the pathway and as the bioactive hormone. It becomes increasingly clear, however, that biological activity extends to and may even differ between the various jasmonic acid metabolites and conjugates as well as its biosynthetic precursors. It has also become clear that oxygenated fatty acids give rise to a vast variety of bioactive compounds including but not limited to jasmonates. Recent insights into the structure, function, and regulation of the enzymes involved in jasmonate biosynthesis help to explain how this variety is generated while specificity is maintained.     

Animal models of Zygomycosis – Absidia,Rhizopus, Rhizomucor,and Cunninghamella

Infections caused by zygomycetes, which have been increasing in recent years, are known for their difficulty of diagnosis and treatment. Because little is known about this fungus and its infection, vigorous research is now in serious demand. As in many other systemic mycoses, animal model studies are essential in the investigation of zygomycosis, particularly for the study of pathogenesis, diagnosis and treatment. Unfortunately, such studies have been limited when compared with those of aspergillosis. To help investigating the disease, here in this review article, the profile of human zygomycosis is briefly described, followed by a review of the heretofore used animal models of zygomycosis. Among clinically important zygomycetes causing human infection, animal models are available for Absidia corymbifera,Rhizopus oryzae,R. microsporus var.rhizopodiformis, Rhizomucor pusillus and Cunninghamella bertholletiae. Mice are the most commonly used animals, but models using guinea pigs and rabbits are also available. Pretreatment of animals with cyclophosphamide, corticosteroid, alloxan or streptozocine is frequently done to create an immunocompromised state. Treatment with desferrioxamine, an iron chelator, is also used to make animal models. In terms of the route of infection, the airborne route is used for pathophysiological studies in pulmonary infection models, but sometimes intravenous injection is preferred, particularly for antifungal drug studies. When pathophysiological analysis is the purpose of the study, the animals must be cautiously examined both histopathologically and mycologically. For the most part, zygomycosis model studies can be performed in a similar manner to those of aspergillosis. However, Aspergillus spp. and zygomycetes are completely different fungi, and researchers should be aware of the specific, critical aspects when handling zygomycosis models, such as homogenization of infected organs and staining of pathological samples. This revised version was published online in August 2006 with corrections to the Cover Date.     

Extracellular vesicles – biogenesis,composition, function,uptake and therapeutic applications

Extracellular vesicles are heterogenous, nano-sized, membrane-limited structures which not only represent a specific way of intercellular communication but also endow cells with many capabilities. Apoptotic bodies created during apoptosis, microvesicles shed from the plasma membrane, and exosomes originated inside the cell and released to extracellular space upon fusion with the plasma membrane, they all belong to extracellular vesicles. Extracellular vesicles contain lipids, proteins, and nucleic acids. In this review, we describe their biogenesis, release and uptake by recipient cells, their composition, functions and potential therapeutic and diagnostic applications.     

Waldenström macroglobulinemia – definition, symptoms, and treatment

Waldenstr?m macroglobulinemia (WM) is a low-grade lymphoplasmacytic lymphoma of mature IgM⁺ B-lymphocytes that remains incurable despite recent practice-altering therapeutic advances and refinements in patient care. Defining features of WM include symptoms that can either be attributed to the extent and site of tissue infiltration by tumor cells or the magnitude and immunological specificity of the monoclonal serum IgM (paraprotein). Current guidelines for the therapeutic stratification of patients with newly diagnosed WM recommend BR (bendamustin-rituximab) for bulky and/or symptomatic disease. DRC (dexamethasone-rituximab-cyclophosphamide) is a good treatment option for relapsed or refractory WM. Ibrutinib – a small-drug inhibitor of Bruton tyrosine kinase, approved for WM treatment in the United States and Europe in 2015 – is particularly effective for tumors that harbor the hallmark MYD88^L265P mutation. Plasma exchange is indicated in patients with IgM-dependent hyperviscosity syndrome. The potential development of novel drugs and combination regimens generates promise that the future of patients with WM is bright.     

Waldenstr?m macroglobulinemia – definition,symptoms, and treatment

Waldenstr?m macroglobulinemia (WM) is a low-grade lymphoplasmacytic lymphoma of mature IgM⁺ B-lymphocytes that remains incurable despite recent practice-altering therapeutic advances and refinements in patient care. Defining features of WM include symptoms that can either be attributed to the extent and site of tissue infiltration by tumor cells or the magnitude and immunological specificity of the monoclonal serum IgM (paraprotein). Current guidelines for the therapeutic stratification of patients with newly diagnosed WM recommend BR (bendamustin-rituximab) for bulky and/or symptomatic disease. DRC (dexamethasone-rituximab-cyclophosphamide) is a good treatment option for relapsed or refractory WM. Ibrutinib – a small-drug inhibitor of Bruton tyrosine kinase, approved for WM treatment in the United States and Europe in 2015 – is particularly effective for tumors that harbor the hallmark MYD88^L265P mutation. Plasma exchange is indicated in patients with IgM-dependent hyperviscosity syndrome. The potential development of novel drugs and combination regimens generates promise that the future of patients with WM is bright.     

Phytotechnologies – Preventing Exposures,Improving Public Health

Phytotechnologies have potential to reduce the amount or toxicity of deleterious chemicals and agents, and thereby, can reduce human exposures to hazardous substances. As such, phytotechnologies are tools for primary prevention in public health. Recent research demonstrates phytotechnologies can be uniquely tailored for effective exposure prevention in a variety of applications. In addition to exposure prevention, plants can be used as sensors to identify environmental contamination and potential exposures. In this paper, we have presented applications and research developments in a framework to illustrate how phytotechnologies can meet basic public health needs for access to clean water, air, and food. Because communities can often integrate plant-based technologies at minimal cost and with low infrastructure needs, the use of these technologies can be applied broadly to minimize potential contaminant exposure and improve environmental quality. These natural treatment systems also provide valuable ecosystem services to communities and society. In the future, integrating and coordinating phytotechnology activities with public health research will allow technology development focused on prevention of environmental exposures to toxic compounds. Hence, phytotechnologies may provide sustainable solutions to environmental exposure challenges, improving public health and potentially reducing the burden of disease.     

d-matrix – database exploration,visualization and analysis

Background  

Motivated by a biomedical database set up by our group, we aimed to develop a generic database front-end with embedded knowledge discovery and analysis features. A major focus was the human-oriented representation of the data and the enabling of a closed circle of data query, exploration, visualization and analysis.     

Dynamics of trace metals in the system water – soil – plant – wild rats – tapeworms (Hymenolepis diminuta) in Maglizh area,Bulgaria

BackgroundThe impact of chemical elements on the biosphere is a function of their concentration and chemical form. Elucidation and prognosing of the latters in water basins and soil extracts is of particular significance for the assessment of their bioaccumulation in plants and animals.ObjectivesTrace metals dynamics in the system water – soil–plant–wild rats – Hymenolepis diminuta in two agro-industrial zones (East and West) around Maglizh city, Bulgaria were investigated through experimental studies and thermodynamic modelling of the chemical species.MethodsSamples from surface waters of rivers, their nearby uncultivated soils, meadow uncultivated vegetation (Ranunculus acris and Gramineae) and field rats were collected. In situ measurements and laboratory analyses were performed for the determination of the physico-chemical characteristics and total concentrations of Al, Fe, Mn, Ni, Cu, Zn and Pb. The distribution of their dissolved chemical species in water samples and in the aqueous soil extracts was calculated using a thermodynamic approach. The relationship chemical species - bioaccumulation was discussed.ResultsWaters and soils in the East zone of Maglizh area were found to be more polluted compared to those in the West one, regarding Ni, Mn, Zn, Pb and Cu, while Mn and Cu displayed the highest mobility in West zone soils. Trace metals contents in Ranunculus acris exceed that in Gramineae, since the highest accumulation factors were calculated for Cu and Zn. The highest accumulation in rats was found for Zn followed by Cu, being higher in the West zone. Thermodynamic modelling shows that Mn²⁺ free ions are dominant in both waters and aqueous soil extracts. Ni²⁺ and Zn²⁺ ions followed by metal-organic complexes are dominant in waters of East zone while metal-organic complexes followed by free ions are dominant in waters of West zone and both soil extracts. Metal-organic complexes are dominant for Fe, Cu and Pb in all samples studied, while mainly hydroxy forms (Al(OH)₄⁻) followed by metal-organic complexes are typically for Al depending on pH.ConclusionsExperimentally established bioaccumulation of trace metals in the studied vegetation and rats is a consequence of the total concentration of trace metals in waters and soils, their mobility and chemical species. The dominance of organic complexes of trace metals is a prerequisite for their bioaccumulation in plants. Rats are in direct contact with the soil solution and therefore, of importance is the content of free ions of Mn²⁺, Ni²⁺, Zn²⁺, which are easily absorbed through the skin. The host-helminth system wild rat/H. diminuta could be used as a bioindicator for trace metals pollution.     

Lipid-based biomarkers for CVD,COPD, and aging – A translational perspective

For many diseases, there is an unmet need for new or better biomarkers for improved disease risk assessment and monitoring, as available markers lack sufficient specificity. Lipids are drawing major interest as potential candidates for filling these gaps. This has recently been demonstrated by the identification of selective ceramides for prediction of cardiovascular mortality, enabling improved risk assessment of cardiovascular disease compared with conventional clinical markers. In this review, we discuss current lipid biomarker findings and the possible connection between cardiovascular disease, chronic obstructive pulmonary disease, and aging. Moreover, we discuss how to overcome the current roadblocks facing lipid biomarker research. We stress the need for improved quantification, standardization of methodologies, and establishment of initial reference values to allow for an efficient transfer path of research findings into the clinical landscape, and, ultimately, to put newly identified biomarkers into practical use.     

The burden of malaria in Sudan: incidence, mortality and disability – adjusted life – years

Background

The goal of Roll Back Malaria (RBM) is to reduce malaria morbidity and mortality by 50% by the year 2010, and still further thereafter until the disease becomes no more a threat to public health. To contribute to the monitoring and evaluation process of this goal, two surveys were carried out in 2000 and 2003 in households and health facilities in the Kassena-Nankana district, northern Ghana using the RBM-WHO/AFRO monitoring and evaluation tools for malaria control activities.

Methods

Data were collected from mothers/caretakers on signs/symptoms of the most recent malaria attack for their under five year old children; the management actions that they took and their perception of health services provided at the health facilities, bednet use, antenatal attendance and place of delivery for the most recent pregnancy, malaria prophylaxis during their last pregnancy. Community health workers and herbalist/traditional healers were also interviewed about the types of health services they provide to community members.

Results

The results revealed a significant improvement in knowledge among mothers/caretakers over the three-year period; this affected caretakers' initial management of illnesses of their young children. The management in terms of the type and dosage of drugs used also improved significantly (p < 0.0001) over the period. Reported insecticide-treated bed net use among children under-five years and pregnant women significantly increased between 2000 and 2003 (p < 0.0001). Health professionals had improved on adoption of their quality of care roles. The intensification of malaria control activities and awareness creation in this district over a three year period had started demonstrating positive results towards reducing malaria disease burden.

Conclusion

Periodic performance assessments through surveys as described and prompt feedback of results to stakeholders in the locality serves as a catalyst to improving malaria control in malaria-endemic countries.     

Rhamnose lipids – biosynthesis, microbial production and application potential

Biosurfactants containing rhamnose and β-hydroxydecanoic acid and called rhamnolipids are reviewed with respect to microbial producers, their physiological role, biosynthesis and genetics, and especially their microbial overproduction, physicochemical properties and potential applications. With Pseudomonas species, more than 100 g l⁻¹ rhamnolipids were produced from 160 g l⁻¹ soybean oil at a volumetric productivity of 0.4 g l⁻¹h⁻¹. The individual rhamnolipids are able to lower the surface tension of water from 72 mN m⁻¹ to 25–30 mN m⁻¹ at concentrations of 10–200 mg l⁻¹. After initial testing, rhamnolipids seem to have potential applications in combating marine oil pollution, removing oil from sand and in combating zoosporic phytopathogens. Rhamnolipids are also a source of l-rhamnose, which is already used for the industrial production of high-quality flavor components. Received: 1 July 1998 / Received revision: 11 September 1998 / Accepted: 13 September 1998