Health-beneficial nutraceuticals—myth or reality?

Applied Microbiology and Biotechnology - The modern term nutraceutical sounds extremely promising to the health-conscious consumers and to the broad audience. But what are the scientific...     

Invasive species: reality or myth?

In view of the recent debate on the future of invasion biology, we argue that species could be regarded as invasive only when after adaptation in non-native habitats they reach yet another fitness maximum. We suggest that invasion biologists need to unambiguously clarify what constitutes being “invasive” to refute those who call for an end to invasion biology.     

Tandem termination signals: myth or reality?

In two Escherichia coli genomes, laboratory strain K-12 and pathological strain O157:H7, tandem termination codons as a group are slightly over-represented as termination signals. Individually however, they span the range of representations, over, as expected, or under, in one or both of the strains. In vivo, tandem termination codons do not make more efficient signals. The second codon can act as a backstop where readthrough of the first has occurred, but not at the expected efficiency. UGAUGA remains an enigma, highly over-represented, but with the second UGA a relatively inefficient back up stop codon.     

Pheromones in birds: myth or reality?

Birds are anosmic or at best microsmatic… This misbelief persisted until very recently and has strongly influenced the outcome of communication studies in birds, with olfaction remaining neglected as compared to acoustic and visual channels. However, there is now clear empirical evidence showing that olfaction is perfectly functional in birds and birds use olfactory information in a variety of ethological contexts. Although the existence of pheromones has never been formally demonstrated in this vertebrate class, different groups of birds, such as petrels, auklets and ducks have been shown to produce specific scents that could play a significant role in within-species social interactions. Behavioral experiments have indeed demonstrated that these odors influence the behavior of conspecifics. Additionally, in quail, deprivation of olfactory inputs decreases neuronal activation induced by sexual interactions with a female. It seems therefore well established that birds enjoy a functional sense of smell and a fast growing body of experimental evidence suggests that they use this channel of olfactory communication to control their social life. The unequivocal identification of an avian pheromone is, however, still ahead of us but there are now many exciting opportunities to unravel the behavioral and physiological particularities of chemical communication in birds.     

Gliotoxin – bane or boon?

Gliotoxin (GT) is the most important epidithiodioxopiperazine (ETP)‐type fungal toxin. GT was originally isolated from Trichoderma species as an antibiotic substance involved in biological control of plant pathogenic fungi. A few isolates of GT‐producing Trichoderma virens are commercially marketed for biological control and widely used in agriculture. Furthermore, GT is long known as an immunosuppressive agent and also reported to have anti‐tumour properties. However, recent publications suggest that GT is a virulence determinant of the human pathogen Aspergillus fumigatus. This compound is thus important on several counts – it has medicinal properties, is a pathogenicity determinant, is a potential diagnostic marker and is important in biological crop protection. The present article addresses this paradox and the ecological role of GT. We discuss the function of GT as defence molecule, the role in aspergillosis and suggest solutions for safe application of Trichoderma‐based biofungicides.     

The ethically trained physician: myth or reality?

Through a questionnaire distributed to 300 physicians in the Toronto area, three aspects of their ethical awareness were examined: the formal codes, the need for consultation in making decisions and the need for training in medical ethics. Most of the physicians (81%) felt that they were facing ethical problems in their daily practice. A majority of these would try to solve the problems either themselves (30%) or through discussion with a colleague (43%). When they turned outside the profession it was sometimes to a lawyer (12%), which suggests concern with the legalities of some situations. Only a small proportion of the respondents were found to be familiar with two of the established codes of ethics, yet 13% would still turn to the code of the Canadian Medical Association for guidance. Finally, there was widespread recognition of the need for proper training in medical ethics and for the establishment of a specialty in this field.     

Left septal fascicular block: myth or reality?

Anatomic studies have shown that the left bundle branch divides into three fascicles in most humans. Changes in the 12 lead ECG (electrocardiogram) due to conduction abnormalities of the left anterior fascicle and left posterior fascicle are now part of the standard repertoire of electrocardiographic interpretation. There are no standard criteria for detecting conduction defects involving the third left fascicle, the septal or median fascicle, and the very existence of such defects is still a matter of controversy. The purposes of this article are to review the available evidence on this subject, suggest electrocardiographic criteria for its recognition, and present examples which illustrate that left septal fascicular block does indeed exist as a specific entity. Left septal fascicular block is a polymorphic conduction defect which may explain some previously inadequately understood electrocardiographic abnormalities.     

Therapeutic agents targetting protein-protein interactions: myth or reality?

Protein-protein interactions have a key role in transduction pathways that regulate many cellular functions. Structural and functional properties of protein-protein interface are now better understood, therefore offering attractive opportunities for therapeutic intervention. Developping small molecules that modulate protein-protein interactions is challenging. Nethertheless, significant progress in this endeavour has been made on several fronts. Here, we use few illustrative examples to summarize recent work in this emerging field.     

Acanthamoeba is an evolutionary ancestor of macrophages: A myth or reality?

Given the remarkable similarities in cellular structure (morphological and ultra-structural features), molecular motility, biochemical physiology, ability to capture prey by phagocytosis and interactions with microbial pathogens, here we pose the question whether Acanthamoeba and macrophages are evolutionary related. This is discussed in the light of evolution and functional aspects such as the astonishing resemblance of many bacteria to infect and multiply inside human macrophages and amoebae in analogous ways. Further debate and studies will determine if Acanthamoeba is an evolutionary ancestor of macrophages. Is this a myth or reality?     

Resource Defence or Exploded Lek? – A Question of Perspective

It becomes increasingly obvious that animal mating systems cannot be classified into distinct categories, but transitions between mating system classes are continuous. Positioning a certain mating system at this continuum is often not straightforward, however. Depending on which characteristic is considered, a mating system may end up at very different positions on this gradient. Here, we explore the potential conflict between mating system classifications that may arise when they are based on different criteria by investigating the mating system of the cichlid fish Simochromis pleurospilus in which males defend small patches of homogeneously distributed food resources (turf algae) vigorously against food competitors, but they allow specific females to use them. We hypothesized that male defence may generate high‐quality feeding patches serving to attract females, and hence male territoriality constitutes a form of courtship. Our field data show that males selectively allow approximately one‐third of the visiting females to feed on their territory and that females preferentially feed in male territories and usually sample several territories successively. As males protect food patches against other algae grazers and guard females from harassment by food competitors, females gain nutritional benefits from visiting male territories. Hence, males appear to generate essential resources for females, which is the key feature of resource‐defence mating systems, although the distributions of resources and of males and females are characteristics of an exploded lek.     

CMA restricted to mammals and birds: myth or reality?

Chaperone-mediated autophagy (CMA) is a major pathway of lysosomal proteolysis essential for the control of intermediary metabolism. So far, the absence of any identifiable LAMP2A – a necessary and limiting protein for CMA – outside of the tetrapod clade, led to the paradigm that this cellular function was (presumably) restricted to mammals and birds. However, after we identified expressed sequences displaying high sequence homology with the mammalian LAMP2A in several fish species, our findings challenge that view and suggest that CMA likely appeared much earlier during evolution than initially thought. Hence, our results do not only shed an entirely new light on the evolution of CMA, but also bring new perspectives on the possible use of complementary genetic models, such as zebrafish or medaka for studying CMA function from a comparative angle/view.     

Enterococcus faecalis infection in root canals – host‐derived or exogenous source?

Aims: Enterococcus faecalis is associated with a significant number of refractory endodontic infections. Previous studies report a prevalence of Ent. faecalis ranging from 24% up to 77% in teeth with failed endodontic treatment. The origin of the micro‐organism remains unclear, as enterococci do not belong to the normal oral microflora. The aim of this study was to determine whether these enterococci were of endogenous or exogenous origin. Methods and Results: Fifty consecutive patients with apical periodontitis in need of endodontic orthograde re‐treatment were included. Samples were collected from root canals, saliva and faeces and subjected to microbiological culturing. The genetic relationship between Ent. faecalis from root canals and isolates from the different host sources was determined using pulsed‐field gel electrophoresis. In 16% (8/50) of the patients, enterococci were collected from the root canal samples. The genetic analysis showed that the isolates from the root canals were not related to those from the normal gastrointestinal microflora. None of these patients had enterococci in their saliva samples. Conclusions: Endodontic infections with Ent. faecalis are probably not derived from the patient’s own normal microflora, which indicates that these infections ent. faecalis are of exogenous origin. Significance and Impact of the Study: This is the first study to genetically compare endodontic infectious Ent. faecalis isolates with isolates from the hosts’ own normal microflora.