Pros and cons: on-line versus off-line analysis of fermentations

A fermenter is a complex system consisting of metabolically active cells suspended in a medium which is often aerated. Since the behaviour of such systems is not determined by the initial conditions fermentations must be subject to closed loop control. Closed loop control can be applied using either on-line or off-line methods.     

Pros and cons of fatty acids in bone biology

Despite the growing interest in deciphering the causes and consequences of obesity-related disorders, the mechanisms linking fat intake to bone behaviour remain unclear. Since bone fractures are widely associated with increased morbidity and mortality, most notably in elderly and obese people, bone health has become a major social and economic issue. Consistently, public health system guidelines have encouraged low-fat diets in order to reduce associated complications. However, from a bone point of view, mechanisms linking fat intake to bone alteration remain quite controversial. Thus, after more than a decade of dedicated studies, this timely review offers a comprehensive overview of the relationships between bone and fatty acids. Using clinical evidences as a starting-point to more complex molecular elucidation, this work highlights the complexity of the system and reveals that bone alteration that cannot be solved simply by taking ω-3 pills. Fatty acid effects on bone metabolism can be both direct and indirect and require integrated investigations. Furthermore, even at the level of a single cell, one fatty acid is able to trigger several different independent pathways (receptors, metabolites…) which may all have a say in the final cellular metabolic response.     

Assessing protein-DNA interactions: Pros and cons of classic and emerging techniques

正Investigation of protein-DNA interactions provides important information for understanding gene function and regulation,but identification and validation of specific interactions remain major challenges in the post-genomics era.Therefore,effective and economical methods to assess protein-DNA interactions are highly sought-after by molecular biologists.Choosing the appropriate method to examine a specific protein-DNA interaction also remains a crucial challenge     

Pros and cons of inhibiting cholesteryl ester transfer protein

Whether or not it is desirable to inhibit cholesteryl ester transfer protein (CETP) has been an important question for over fifteen years since genetic CETP deficiency was found. Recently, some epidemiological studies which have been reported in Japan as well as Western countries help to clarify the atherogenicity of human subjects with mutations or polymorphisms in the CETP gene. In addition, some experimental atherosclerosis studies, in which CETP was inhibited in rabbits with different approaches, have been reported. There was a considerable difference in the atherogenicity of human CETP deficiency and CETP-inhibited rabbits. In this review, we summarize the recent advances in this field as well as discussing the significance of CETP in reverse cholesterol transport, a major protective system against atherosclerosis.     

Pros and cons of a prion-like pathogenesis in Parkinson's disease

Background  

Parkinson's disease (PD) is a slowly progressive neurodegenerative disorder which affects widespread areas of the brainstem, basal ganglia and cerebral cortex. A number of proteins are known to accumulate in parkinsonian brains including ubiquitin and α-synuclein. Prion diseases are sporadic, genetic or infectious disorders with various clinical and histopathological features caused by prion proteins as infectious proteinaceous particles transmitting a misfolded protein configuration through brain tissue. The most important form is Creutzfeldt-Jakob disease which is associated with a self-propagating pathological precursor form of the prion protein that is physiologically widely distributed in the central nervous system.     

Pros and cons for Martian life: scientific debate on ALH84001]

Scientific debate related to possible martian life is summarized in this article. Even there is no firm conclusion yet to convince the existence of life on Mars, intensive studies on the meteorite ALH84001 have invoked many valuable findings.     

Radiolabelled proteins for positron emission tomography: Pros and cons of labelling methods

Background

Dynamic biomedical research is currently yielding a wealth of information about disease-associated molecular alterations on cell surfaces and in the extracellular space. The ability to visualize and quantify these alterations in vivo could provide important diagnostic information and be used to guide individually-optimized therapy. Biotechnology can provide proteinaceous molecular probes with highly specific target recognitions. Suitably labelled, these may be used as tracers for radionuclide-based imaging of molecular disease signatures. If the labels are positron-emitting radionuclides, the superior resolution, sensitivity and quantification capability of positron emission tomography (PET) can be exploited.

Scope of review

This article discusses different approaches to labelling proteins with positron-emitting nuclides with suggestions made depending on the biological features of the tracers.

Major conclusions

Factors such as matching biological and physical half-lives, availability of the nuclide, labelling yields, and influences of labelling on targeting properties (affinity, charge and lipophilicity, cellular processing and retention of catabolites) should be considered when selecting a labelling strategy for each proteinaceous tracer.

General significance

The labelling strategy used can make all the difference between success and failure in a tracer application. This review emphasises chemical, biological and pharmacological considerations in labelling proteins with positron-emitting radionuclides.     

Pros and cons of external swabbing of amphibians for genetic analyses

Non-invasive DNA sampling is an important tool in amphibian conservation. Buccal swabs are nowadays replacing the wounding toe-clipping method. Skin and cloaca swabbing are even less invasive and easier to handle than buccal swabbing, but could result in contaminations of genetic material. Therefore, we test if external skin and cloaca swabs are as reliable as buccal swabs for genetic analysis of amphibians. We analysed eight microsatellite loci for the common frog (Rana temporaria, Linnaeus 1758) and compared genotyping results for buccal, skin and cloaca swabs regarding allelic dropouts and false alleles. Furthermore, we compared two DNA extraction methods regarding efficiency and cost. DNA quality and quantity (amplification success, genotyping error rate, in nanogram per microlitre) were comparable among DNA sources and extraction methods. However, skin and cloaca samples exhibited high degrees of contamination with foreign individuals, which was due to sample collection during mating season. Here, we established a simple low budget procedure to receive DNA of amphibians avoiding stressful buccal swabbing or harmful toe clipping. However, the possibility of contaminations of external swabs has to be considered.     

Pros and cons of the liposome platform in cancer drug targeting

Coating of liposomes with polyethylene-glycol (PEG) by incorporation in the liposome bilayer of PEG-derivatized lipids results in inhibition of liposome uptake by the reticulo-endothelial system and significant prolongation of liposome residence time in the blood stream. Parallel developments in drug loading technology have improved the efficiency and stability of drug entrapment in liposomes, particularly with regard to cationic amphiphiles such as anthracyclines. An example of this new generation of liposomes is a formulation of pegylated liposomal doxorubicin known as Doxil or Caelyx, whose clinical pharmacokinetic profile is characterized by slow plasma clearance and small volume of distribution. A hallmark of these long-circulating liposomal drug carriers is their enhanced accumulation in tumors. The mechanism underlying this passive targeting effect is the phenomenon known as enhanced permeability and retention (EPR) which has been described in a broad variety of experimental tumor types. Further to the passive targeting effect, the liposome drug delivery platform offers the possibility of grafting tumor-specific ligands on the liposome membrane for active targeting to tumor cells, and potentially intracellular drug delivery. The pros and cons of the liposome platform in cancer targeting are discussed vis-à-vis nontargeted drugs, using as an example a liposome drug delivery system targeted to the folate receptor.     

Modelling reproductive allocation of dusky salamanders using optimal control theory: Pros,cons and caveats

Summary Optimal control theory has been used to examine the evolution of life history characters in a variety of plant and animal species. In this paper, I examine control theoretic models of reproductive allocation in female dusky salamanders and consider some practical aspects of modelling, including the appropriateness of nonlinear formulations, methods for describing semelparous reproduction, and data needed to parameterize models. The model analysed includes state variables for somatic and reproductive tissue, energy intake and requirements for physiological maintenance, and iteroparous reproduction. It predicts that female salamanders should spend the first part of their lives growing. After reaching sexual maturity, females should either spend the remainder of their lives reproducing at the expense of decreasing body size, possibly resulting in death by starvation, or maintain approximately constant body size at the expense of low reproductive output. This lack of correspondence to the observed biology of dusky salamanders suggests that not all the appropriate biology has been described. In particular, inclusion of a storage variable may be necessary in future modelling efforts.     

Material & equipment,procurement & maintenance: Impact on blood safety

Blood Transfusion Safety is dependent on effectively organised and managed blood services, which have adequate financial resources, skilled manpower, appropriate infrastructure and quality management systems in place.80% of the world's population has access to 20% of the supply blood products, of which little is consistently safe.HIV highlighted the importance of blood safety. The lack of effective blood services in low human development index (LHDI), developing countries, has lead to international funding and capacity building for more than three decades. The initial strategies focused on providing HIV testing reagents to prevention transmission, however this only addresses one part of blood safety.Blood safety is not only dependent on preventing HIV transmission. In many populations there are other infectious agents, which have a higher prevalence. Ensuring the correct blood is provided to the patient depends on: well managed services with effective leadership and adequate budgets; capacity building and retention of skilled experienced staff; availability of laboratory equipment, correctly maintained; blood cold chain systems; procedures for tendering, purchasing and ensuring an unbroken supply of reagents and consumables; and quality management systems.Barriers for simplified effective tendering, procurement and contracting require urgent attention and coordination of all funding organisations to ensure an unbroken supply of reagents.     

Pros and cons of using a standard protocol to test germination of alpine species

Plant Ecology - Storing seeds in seed banks is an effective way to preserve plant diversity and conserve species. An essential step towards a valuable conservation is the validation of germination....     

Pros and cons of using aberrant glycosylation as companion biomarkers for therapeutics in cancer

Cancer treatment has been stratified by companion biomarker tests that serve to provide information on the genetic status of cancer patients and to identify patients who can be expected to respond to a given treatment. This stratification guarantees better efficiency and safety during treatment. Cancer patients, however, marginally benefit from the current companion biomarker-aided treatment regimens, presumably because companion biomarker tests are dependent solely on the mutation status of several genes status quo. In the true sense of the term, "personalized medicine", cancer patients are deemed to be identified individually by their molecular signatures, which are not necessarily confined to genetic mutations. Glycosylation is tremendously dynamic and shows alterations in cancer. Evidence is accumulating that aberrant glycosylation contributes to the development and progression of cancer, holding the promise for use of glycosylation status as a companion biomarker in cancer treatment. There are, however, several challenges derived from the lack of a reliable detection system for aberrant glycosylation, and a limited library of aberrant glycosylation. The challenges should be addressed if glycosylation status is to be used as a companion biomarker in cancer treatment and contribute to the fulfillment of personalized medicine.     

Functional role of forest diversity: Pros and cons of synthetic stands and across-site comparisons in established forests

In contrast to grasslands, forests have only rarely been the subject of functional biodiversity research. This paper addresses specific problems, which arise from applying the synthetic stand approach to long-lived plants, which can be taken to simulate the loss or addition of tree species or tree functional groups in forest stands. Planted synthetic stands often deviate from natural forests in several properties including trophic structure, tree age distribution, and horizontal and vertical canopy structures. Moreover, edge effects and the absence of a quasi-steady state in soil development limit the spectrum of processes which can be analysed for biodiversity effects in synthetic tree stands. We propose that these shortcomings can partly be overcome by combining the synthetic stand approach with observational studies in existing forest stands of contrasting tree diversity. The potentials and limitations of comparisons among existing stands for functional biodiversity research are briefly discussed using the example of the Hainich Tree Diversity Matrix, a species-rich temperate broad-leaved forest consisting of a small-scale mosaic of stands differing in tree diversity, which originated from a variety of historic forest-use practices.