bluuebunny/crossref_metadata_2025 huggingface dataset:
Resource polyphenism increases species richness: a test of the hypothesis
Authors: Pfennig David W. , McGee Matthew
Published: January 2010

A major goal of evolutionary biology is to identify the causes of diversification and to ascertain why some evolutionary lineages are especially diverse. Evolutionary biologists have long speculated that polyphenism—where a single genome produces alternative phenotypes in response to different environmental stimuli—facilitates speciation, especially when these alternative phenotypes differ in resource or habitat use, i.e. resource polyphenism. Here, we present a series of replicated sister-group comparisons showing that fishes and amphibian clades in which resource polyphenism has evolved are more species rich, and have broader geographical ranges, than closely related clades lacking resource polyphenism. Resource polyphenism may promote diversification by facilitating each of the different stages of the speciation process (isolation, divergence, reproductive isolation) and/or by reducing a lineage's risk of extinction. Generally, resource polyphenism may play a key role in fostering diversity, and species in which resource polyphenism has evolved may be predisposed to diversify.
The initiation of metamorphosis as an ancient polyphenic trait and its role in metazoan life-cycle evolution
Authors: Degnan Sandie M. , Degnan Bernard M.
Published: January 2010

Comparative genomics of representative basal metazoans leaves little doubt that the most recent common ancestor to all modern metazoans was morphogenetically complex. Here, we support this interpretation by demonstrating that the demospongeAmphimedon queenslandicahas a biphasic pelagobenthic life cycle resembling that present in a wide range of bilaterians and anthozoan cnidarians. TheA. queenslandicalife cycle includes a compulsory planktonic larval phase that can end only once the larva develops competence to respond to benthic signals that induce settlement and metamorphosis. The temporal onset of competence varies between individuals as revealed by idiosyncratic responses to inductive cues. Thus, the biphasic life cycle with a dispersing larval phase of variable length appears to be a metazoan synapomorphy and may be viewed as an ancestral polyphenic trait. Larvae of a particular age that are subjected to an inductive cue either maintain the larval form or metamorphose into the post-larval/juvenile form. Variance in the development of competence dictates that only a subset of a larval cohort will settle and undergo metamorphosis at a given time, which in turn leads to variation in dispersal distance and in location of settlement. Population divergence and allopatric speciation are likely outcomes of this conserved developmental polyphenic trait.
Conflicting processes in the evolution of body size and development time
Authors: Nijhout H. Frederik , Roff Derek A. , Davidowitz Goggy
Published: January 2010

Body size and development time ofManduca sextaare both determined by the same set of three developmental–physiological factors. These define a parameter space within which it is possible to analyse and explain how phenotypic change is associated with changes in the underlying factors. Body size and development time are determined by the identical set of underlying factors, so they are not independent, but because the mechanisms by which these factors produce each phenotype are different, the two phenotypes are only weakly correlated, and the correlation is context dependent. We use a mathematical model of this mechanism to explore the association between body size and development time and show that the correlation between these two life-history traits can be positive, zero or negative, depending entirely on where in parameter space a population is located, and on which of the underlying factors has a greater variation. The gradient within this parameter space predicts the unconstrained evolutionary trajectory under directional selection on each trait. Calculations of the gradients for body size and development time revealed that these are nearly orthogonal through much of the parameter space. Therefore, simultaneous directional selection on body size and development time can be neither synergistic nor antagonistic but leads to conflicting selection on the underlying developmental parameters.
Indirect development, transdifferentiation and the macroregulatory evolution of metazoans
Authors: Arenas-Mena Cesar
Published: January 2010

It is proposed here that a biphasic life cycle with partial dedifferentiation of intermediate juvenile or larval stages represents the mainstream developmental mode of metazoans. Developmental plasticity of differentiated cells is considered the essential characteristic of indirect development, rather than the exclusive development of the adult from ‘set-aside’ cells. Many differentiated larval cells of indirect developers resume proliferation, partially dedifferentiate and contribute to adult tissues. Transcriptional pluripotency of differentiated states has premetazoan origins and seems to be facilitated by histone variant H2A.Z. Developmental plasticity of differentiated states also facilitates the evolution of polyphenism. Uncertainty remains about whether the most recent common ancestor of protostomes and deuterostomes was a direct or an indirect developer, and how the feeding larvae of bilaterians are related to non-feeding larvae of sponges and cnidarians. Feeding ciliated larvae of bilaterians form their primary gut opening by invagination, which seems related to invagination in cnidarians. Formation of the secondary gut opening proceeds by protostomy or deuterostomy, and gene usage suggests serial homology of the mouth and anus. Indirect developers do not use the Hox vector to build their ciliated larvae, but the Hox vector is associated with the construction of the reproductive portion of the animal during feeding-dependent posterior growth. It is further proposed that the original function of the Hox cluster was in gonad formation rather than in anteroposterior diversification.
Evaluating the role of reproductive constraints in ant social evolution
Authors: Khila Abderrahman , Abouheif Ehab
Published: January 2010

The reproductive division of labour is a key feature of eusociality in ants, where queen and worker castes show dramatic differences in the development of their reproductive organs. To understand the developmental and genetic basis underlying this division of labour, we performed a molecular analysis of ovary function and germ cell development in queens and workers. We show that the processes of ovarian development in queens have been highly conserved relative to the fruitflyDrosophila melanogaster. We also identify specific steps during oogenesis and embryogenesis in which ovarian and germ cell development have been evolutionarily modified in the workers. These modifications, which we call ‘reproductive constraints’, are often assumed to represent neutral degenerations that are a consequence of social evolutionary forces. Based on our developmental and functional analysis of these constraints, however, we propose and discuss the alternative hypothesis that reproductive constraints represent adaptive proximate mechanisms or traits for maintaining social harmony in ants. We apply a multi-level selection framework to help understand the role of these constraints in ant social evolution. A complete understanding of how cooperation, conflict and developmental systems evolve in social groups requires a ‘socio-evo-devo’ approach that integrates social evolutionary and developmental biology.
Idealization in evolutionary developmental investigation: a tension between phenotypic plasticity and normal stages
Authors: Love Alan C.
Published: January 2010

Idealization is a reasoning strategy that biologists use to describe, model and explain that purposefully departs from features known to be present in nature. Similar to other strategies of scientific reasoning, idealization combines distinctive strengths alongside of latent weaknesses. The study of ontogeny in model organisms is usually executed by establishing a set of normal stages for embryonic development, which enables researchers in different laboratory contexts to have standardized comparisons of experimental results. Normal stages are a form of idealization because they intentionally ignore known variation in development, including variation associated with phenotypic plasticity (e.g. via strict control of environmental variables). This is a tension between the phenomenon of plasticity and the practice of staging that has consequences for evolutionary developmental investigation because variation is conceptually removed as a part of rendering model organisms experimentally tractable. Two compensatory tactics for mitigating these consequences are discussed: employing a diversity of model organisms and adopting alternative periodizations.
Phenotypic plasticity and diversity in insects
Authors: Moczek Armin P.
Published: January 2010

Phenotypic plasticity in general and polyphenic development in particular are thought to play important roles in organismal diversification and evolutionary innovation. Focusing on the evolutionary developmental biology of insects, and specifically that of horned beetles, I explore the avenues by which phenotypic plasticity and polyphenic development have mediated the origins of novelty and diversity. Specifically, I argue that phenotypic plasticity generates novel targets for evolutionary processes to act on, as well as brings about trade-offs during development and evolution, thereby diversifying evolutionary trajectories available to natural populations. Lastly, I examine the notion that in those cases in which phenotypic plasticity is underlain by modularity in gene expression, it results in a fundamental trade-off between degree of plasticity and mutation accumulation. On one hand, this trade-off limits the extent of plasticity that can be accommodated by modularity of gene expression. On the other hand, it causes genes whose expression is specific to rare environments to accumulate greater variation within species, providing the opportunity for faster divergence and diversification between species, compared with genes expressed across environments. Phenotypic plasticity therefore contributes to organismal diversification on a variety of levels of biological organization, thereby facilitating the evolution of novel traits, new species and complex life cycles.
Developmental plasticity and the evolution of animal complex life cycles
Authors: Minelli Alessandro , Fusco Giuseppe
Published: January 2010

Metazoan life cycles can be complex in different ways. A number of diverse phenotypes and reproductive events can sequentially occur along the cycle, and at certain stages a variety of developmental and reproductive options can be available to the animal, the choice among which depends on a combination of organismal and environmental conditions.

We hypothesize that a diversity of phenotypes arranged in developmental sequence throughout an animal's life cycle may have evolved by genetic assimilation of alternative phenotypes originally triggered by environmental cues.

This is supported by similarities between the developmental mechanisms mediating phenotype change and alternative phenotype determination during ontogeny and the common ecological condition that favour both forms of phenotypic variation.

The comparison of transcription profiles from different developmental stages throughout a complex life cycle with those from alternative phenotypes in closely related polyphenic animals is expected to offer critical evidence upon which to evaluate our hypothesis.
Coordinate action of membrane‐type matrix metalloproteinase‐1 (MT1‐MMP) and MMP‐2 enhances pericellular proteolysis and invasion
Authors: Sato Hiroshi , Takino Takahisa
Published: January 2010

Membrane‐type matrix metalloproteinase‐1 (MT1‐MMP) mediates cleavage of not only MMP‐2/gelatinase A for activation, but also a variety of substrates including type I collagen (reviewed in Cancer Sci 2005; 96: 212–7). MMP‐2 activation involves tissue inhibitor of MMP (TIMP)‐2 as a bridging molecule between MT1‐MMP and pro‐MMP‐2. Thus, net activity of MT1‐MMP and MMP‐2 is regulated in a complex manner depending on TIMP‐2 concentration. During invasive growth of tumor cells in type I collagen matrix, MT1‐MMP initiates denaturation of collagen into gelatin, which is subsequently digested further by MMP‐2 adjacent to MT1‐MMP. Coordinate action of MT1‐MMP and MMP‐2 may facilitate pericellular proteolysis, and enhance not only tumor invasion/migration but also cell growth. Tetraspanins as binding proteins of MT1‐MMP regulate MT1‐MMP subcellular localization and compartmentalization, leading to efficient MMP‐2 activation and proteolysis coupled with cellular function.

(Cancer Sci 2010; 101: 843–847)
Meta‐analysis: folic acid in the chemoprevention of colorectal adenomas and colorectal cancer
Authors: CARROLL C. , COOPER K. , PAPAIOANNOU D. , HIND D. , TAPPENDEN P. , PILGRIM H. , BOOTH A.
Published: January 2010

Aliment Pharmacol Ther 31, 708–718

Background  Folic acid has been identified as a possible agent for the chemoprevention of colorectal cancer.

Aim  To assess the effectiveness of folic acid in reducing the recurrence of adenomas (precursors of colorectal cancer) among populations with a history of adenomas and the incidence of colorectal cancer within average‐risk populations.

Methods  Systematic review of randomized controlled trials comparing folic acid alone, or with other agents, vs. placebo. Eight databases were searched for relevant trials. Meta‐analysis was performed.

Results  The literature search retrieved 3785 citations. Six studies met the inclusion criteria. Meta‐analysis of three studies in individuals with a history of adenomas showed no statistically significant difference in the relative risk of adenoma recurrence (RR 0.93, P = 0.27). A sensitivity analysis of the two higher quality trials changed the direction of effect (RR 1.16, P = 0.11). Meta‐analysis of three trials in general populations demonstrated no statistically significant effect on the relative risk of colorectal cancer (RR 1.13, P = 0.54). In all three analyses, outcome event rates were higher in individuals receiving folic acid.

Conclusion  There is no evidence that folic acid is effective in the chemoprevention of colorectal adenomas or colorectal cancer for any population.
Walled sedimentary basins of China
Authors: Carroll A. R. , Graham S. A. , Smith M.E.
Published: January 2010

Central Asia contains numerous closed geomorphic basins that are surrounded by active mountain ranges, but exhibit little internal deformation. These areas commonly coincide with sedimentary basins that record a much older history of continuous internal drainage, evidenced by lacustrine and associated alluvial deposits that date as back far as the Late Permian. We propose the new descriptive term ‘walled basin’, in recognition of the unique physiography of basins that impound sediments within peripheral orogenic walls that are maintained over relatively long geologic time scales. Walled basins are surrounded by dominantly contractional orogenic uplifts, but are themselves relatively undeformed. They typically record multiple episodes of alluvial and lacustrine sedimentation, that are often correlated with evidence for recurrent deformation of basin‐bounding uplifts. The distribution of walled basins in Asia appears to correspond to crustal heterogeneities inherited from the complex accretionary history of the continent, but actual mechanisms for maintaining stable basin interiors over periods as long as ∼250 my remain uncertain. Modern walled basins in Asia are restricted to arid or semiarid regions, due to the capacity of large rivers to defeat drainage barriers in more humid areas. Walled basins lie at lower elevations than Asia as whole, and they appear to impede rather than promote plateau growth.
High‐dose chemo‐radiotherapy for relapsed or refractory Hodgkin lymphoma and the significance of pre‐transplant functional imaging
Authors: Moskowitz Craig H. , Yahalom Joachim , Zelenetz Andrew D. , Zhang Zhigang , Filippa Daniel , Teruya‐Feldstein Julie , Kewalramani Tarun , Moskowitz Alison J. , Rice Robert David , Maragulia Jocelyn , Vanak Jill , Trippett Tanya , Hamlin Paul , Horowitz Steven , Noy Ariela , O’Connor Owen A. , Portlock Carol , Straus David , Nimer Stephen D.
Published: January 2010

We previously reported that three risk factors (RF): initial remission duration <1 year, active B symptoms, and extranodal disease predict outcome in relapsed or refractory Hodgkin lymphoma (HL). Our goal was to improve event‐free survival (EFS) for patients with multiple RF and to determine if response to salvage therapy impacted outcome. We conducted a phase II intent‐to‐treat study of tailored salvage treatment: patients with zero or one RF received standard‐dose ifosfamide, carboplatin, and etoposide (ICE); patients with two RF received augmented ICE; patients with three RF received high‐dose ICE with stem cell support. This was followed by evaluation with both computed tomography and functional imaging (FI); those with chemosensitive disease underwent high‐dose chemoradiotherapy and autologous stem cell transplantation (ASCT). There was no treatment‐related mortality. Compared to historical controls this therapy eliminated the difference in EFS between the three prognostic groups. Pre‐ASCT FI predicted outcome; 4‐year EFS rates was 33% vs. 77% for patients transplanted with positive versus negative FI respectively, P = 0·00004, hazard ratio 4·61. Risk‐adapted augmentation of salvage treatment in patients with HL is feasible and improves EFS in poorer‐risk patients. Our data suggest that normalisation of FI pre‐ASCT predicts outcome, and should be the goal of salvage treatment.
Metal contact sites: a hidden localization for nail varnish allergy?
Authors: Özkaya E. , Ekinci A.
Published: January 2010

It is thought that many people with nickel dermatitis use nail varnish as a barrier coat on nickel-containing metals; however, nail varnish allergy at sites in contact with such coated has only been documented once previously, to our knowledge. The aim of this study was to search for a possible link between nail varnish and metal allergy. In total, 1607 consecutively patch-tested patients were enrolled; 16 (1%) of these had nail varnish allergy, located mainly on the eyelids. Eight also had nickel allergy. Six of these eight had successfully used protective nail varnish on metals until subsequent development of ‘failure of protection’ even before the eyelid eczema developed. Sites in contact with metal might be a hidden and even initial localization for nail varnish allergy. ‘Failure of protection’ after a successful protective period despite renewing nail varnish coatings should raise suspicion of sensitization to the nail varnish itself. Future studies should focus on the incidence of allergic contact dermatitis and primary sensitization from nail varnish used as a barrier against nickel dermatitis.
Novel RNA polymerase II mutation suppresses transcriptional fidelity and oxidative stress sensitivity in rpb9Δ yeast
Authors: Koyama Hiroshi , Ueda Tomofumi , Ito Takahiro , Sekimizu Kazuhisa
Published: January 2010

We previously reported that transcription elongation factor S‐II and RNA polymerase II subunit Rpb9 maintain transcriptional fidelity and contribute to oxidative stress resistance in yeast. Here we examined whether other transcription elongation‐related factors affect transcriptional fidelity in vivo. Among the 17 mutants of transcription elongation‐related factors analyzed, most were not responsible for maintaining transcriptional fidelity. This finding indicates that transcriptional fidelity is controlled by a limited number of transcription elongation‐related factors including S‐II and Rpb9 and not by all transcription elongation‐related factors. In contrast, by screening rpb9Δ cell revertants for sensitivity to the oxidant menadione, we identified a novel mutation in RNA polymerase II, rpb1‐G730D, which suppressed both reduced transcriptional fidelity and oxidative stress sensitivity. These findings suggest that the maintenance of transcriptional fidelity that is mediated by transcription machinery directly confers oxidative stress resistance.
Timing of blooms, algal food quality and Calanus glacialis reproduction and growth in a changing Arctic
Authors: SØREIDE JANNE E. , LEU EVA , BERGE JØRGEN , GRAEVE MARTIN , FALK‐PETERSEN STIG
Published: January 2010

The Arctic bloom consists of two distinct categories of primary producers, ice algae growing within and on the underside of the sea ice, and phytoplankton growing in open waters. Long chain omega‐3 fatty acids, a subgroup of polyunsaturated fatty acids (PUFAs) produced exclusively by these algae, are essential to all marine organisms for successful reproduction, growth, and development. During an extensive field study in the Arctic shelf seas, we followed the seasonal biomass development of ice algae and phytoplankton and their food quality in terms of their relative PUFA content. The first PUFA‐peak occurred in late April during solid ice cover at the onset of the ice algal bloom, and the second PUFA‐peak occurred in early July just after the ice break‐up at the onset of the phytoplankton bloom. The reproduction and growth of the key Arctic grazer Calanus glacialis perfectly coincided with these two bloom events. Females of C. glacialis utilized the high‐quality ice algal bloom to fuel early maturation and reproduction, whereas the resulting offspring had access to ample high‐quality food during the phytoplankton bloom 2 months later. Reduction in sea ice thickness and coverage area will alter the current primary production regime due to earlier ice break‐up and onset of the phytoplankton bloom. A potential mismatch between the two primary production peaks of high‐quality food and the reproductive cycle of key Arctic grazers may have negative consequences for the entire lipid‐driven Arctic marine ecosystem.
The value of early treatment in patients with haemophilia and inhibitors
Authors: KAVAKLI K. , YESILIPEK A. , ANTMEN B. , AKSU S. , BALKAN C. , YILMAZ D. , KUPESIZ A. , SASMAZ I. , LINDGREN P. , MESTERTON J.
Published: January 2010

Summary. Development of inhibitors to infused factor concentrates represents a major clinical and economic challenge in the treatment of haemophilic patients. It has been shown that a delay in initiation of treatment leads to requirement of a larger number of injections to stop the bleeding but this has never been formally linked to costs associated with the bleeding. The objectives of this study were to assess the relationship between time to initiation of NovoSeven®and total costs, number of doses administered and time to bleeding resolution in mild to moderate bleeding episodes. Data on time to treatment initiation, time to bleeding resolution and on all resource use related to the bleeding were extracted from medical records in Turkey for 129 bleeding episodes. Regression analysis was used to assess the impact of time to treatment on outcomes. Longer time to treatment initiation increased both total costs associated with the bleeding, the number of doses needed and the time to bleeding resolution. Treatment in hospital was associated with significantly longer time to treatment, higher costs and longer time to bleeding resolution as compared with home treatment or outpatient treatment. When controlling for other bleeding characteristics, the cost of bleedings treated in hospital was more than 150% higher. This study shows that treatment with NovoSeven®should be initiated as soon as possible after the onset of bleeding in order to minimize costs and optimize outcomes. Home treatment reduces time to treatment initiation and also reduces costs related to the bleeding.
Vasopressin and the Output of the Hypothalamic Biological Clock
Authors: Kalsbeek A. , Fliers E. , Hofman M. A. , Swaab D. F. , Buijs R. M.
Published: January 2010

The physiological effects of vasopressin as a peripheral hormone were first reported more than 100 years ago. However, it was not until the first immunocytochemical studies were carried out in the early 1970s, using vasopressin antibodies, and the discovery of an extensive distribution of vasopressin‐containing fibres outside the hypothalamus, that a neurotransmitter role for vasopressin could be hypothesised. These studies revealed four additional vasopressin systems next to the classical magnocellular vasopressin system in the paraventricular and supraoptic nuclei: a sexually dimorphic system originating from the bed nucleus of the stria terminalis and the medial amygdala, an autonomic and endocrine system originating from the medial part of the paraventricular nucleus, and the circadian system originating from the hypothalamic suprachiasmatic nuclei (SCN). At about the same time as the discovery of the neurotransmitter function of vasopressin, it also became clear that the SCN contain the main component of the mammalian biological clock system (i.e. the endogenous pacemaker). This review will concentrate on the significance of the vasopressin neurones in the SCN for the functional output of the biological clock that is contained within it. The vasopressin‐containing subpopulation is a characteristic feature of the SCN in many species, including humans. The activity of the vasopressin neurones in the SCN shows a pronounced daily variation in its activity that has also been demonstrated in human post‐mortem brains. Animal experiments show an important role for SCN‐derived vasopressin in the control of neuroendocrine day/night rhythms such as that of the hypothalamic‐pituitary‐adrenal and hypothalamic‐pituitary‐gonadal axes. The remarkable correlation between a diminished presence of vasopressin in the SCN and a deterioration of sleep‐wake rhythms during ageing and depression make it likely that, also in humans, the vasopressin neurones contribute considerably to the rhythmic output of the SCN.
Increased Sensitivity of Monoamine Release in the Supraoptic Nucleus in Late Pregnancy: Region‐ and Stimulus‐Dependent Responses
Authors: Tobin V. A. , Leng G. , Ludwig M. , Douglas A. J.
Published: January 2010

Oxytocin neurone activation at birth depends upon noradrenaline‐mediated signals from the uterus via a brainstem pathway, as well as on factors within the supraoptic nucleus (SON), including oxytocin itself, and the system adapts during pregnancy to optimise the delivery process. We determined whether noradrenaline release in the SON in response to stimuli activating brainstem inputs or antidromically activating magnocellular neurones is enhanced at term pregnancy. Noradrenaline, serotonin and dopamine concentrations were measured in microdialysis samples collected from the dorsal and ventral SON before, during and after either i.v. cholecystokinin (CCK) or neural stalk stimulation in virgin and late pregnant rats. Each stimulus transiently increased noradrenaline and serotonin but not dopamine concentration in the dorsal SON, and responses were increased on days 21 and 22 of pregnancy compared to day 20 pregnant and virgin rats. Neural stalk stimulation induced sensitisation to subsequent stalk stimulation and so the responses in the dorsal SON were doubled; on day 22 of pregnancy, the area under the curve of monoamine concentration was 3.4‐fold greater than in virgins, suggesting that adaptations perinatally enhance responsiveness. In conclusion, there are enhanced responses of noradrenaline and serotonin release in the SON that can generate very high, transient extracellular concentrations at term. This may be a consequence of neuroendocrine adaptations in late pregnancy and probably contributes to optimal oxytocin neurone activation during parturition.
Automatic, computer‐based speech assessment on edentulous patients with and without complete dentures – preliminary results
Authors: STELZLE F. , UGRINOVIC B. , KNIPFER C. , BOCKLET T. , NÖTH E. , SCHUSTER M. , EITNER S. , SEISS M. , NKENKE E.
Published: January 2010

Summary Dental rehabilitation of edentulous patients with complete dentures includes not only aesthetics and mastication of food, but also speech quality. It was the aim of this study to introduce and validate a computer‐based speech recognition system (ASR) for automatic speech assessment in edentulous patients after dental rehabilitation with complete dentures. To examine the impact of dentures on speech production, the speech outcome of edentulous patients with and without complete dentures was compared. Twenty‐eight patients reading a standardized text were recorded twice – with and without their complete denturesin situ. A control group of 40 healthy subjects with natural dentition was recorded under the same conditions. Speech quality was evaluated by means of a polyphone‐based ASR according to the percentage of the word accuracy (WA). Speech acceptability assessment by expert listeners and the automatic rating of the WA by the ASR showed a high correlation (corr = 0·71). Word accuracy was significantly reduced in edentulous speakers (55·42 ± 13·1) compared to the control group’s WA (69·79 ± 10·6). On the other hand, wearing complete dentures significantly increased the WA of the edentulous patients (60·00 ± 15·6). Speech production quality is significantly reduced after complete loss of teeth. Reconstitution of speech production quality is an important part of dental rehabilitation and can be improved for edentulous patients by means of complete dentures. The ASR has proven to be a useful and easily applicable tool for automatic speech assessment in a standardized way.
Subjective food intake ability in relation to the Mixing Ability Index in Korean adults
Authors: JEONG S.H. , KANG S.M. , RYU J.H. , KWON H.K. , KIM B.I.
Published: January 2010

Summary  This study examined the association between the subjective food intake ability (FIA) using a questionnaire with 30 types of foods and the objective Mixing Ability Index (MAI) using a two‐coloured wax cube. A total of 147 subjects (32 males, 115 females, mean age: 54·9 ± 20·7) were enrolled in this study. The FIA for 30 food types and the key food intake ability (KFIA) for five key food types were obtained using a self‐assessed questionnaire to evaluate the subjective chewing ability. The objective chewing ability was evaluated by asking the subjects to chew a wax cube for 10 strokes. The MAI was calculated by image analysis of the chewed wax cube. The Pearson’s correlation between the subjective FIA and objective MAI was analysed according to age and number of post‐canine teeth lost. The FIA for the 30 foods and five key food types showed a moderate correlation with the MAI (r = 0·51, 0·55, respectively, P < 0·01). The KFIA of the denture wearing group (r = 0·44, P < 0·01) and over 60‐year‐old group (r = 0·49, P < 0·01) showed a significantly higher correlation with the MAI than the other groups. In conclusion, there was a moderate correlation between the subjective FIA and objective MAI in Korean adults.
Quality of communication and master impressions for the fabrication of cobalt chromium removable partial dentures in general dental practice in England, Ireland and Wales in 2009
Authors: KILFEATHER G. P. , LYNCH C. D. , SLOAN A. J. , YOUNGSON C. C.
Published: January 2010

Summary  The aim of this study was to investigate the quality of communication and master impressions for the fabrication of cobalt chromium removable partial dentures (RPDs) in general dental practice in England, Ireland and Wales in 2009. Two hundred and ten questionnaires were distributed to 21 laboratories throughout England, Ireland and Wales. Information was collected regarding the quality of written communication and selection of master impression techniques for cobalt chromium partial dentures in general dental practice. One hundred and forty‐four questionnaires were returned (response rate = 68%). Alginate was the most popular impression material being used in 58% of cases (n = 84), while plastic stock trays were the most popular impression tray, being used in 31% of cases (n = 44). Twenty‐four per cent (n = 35) of impressions were not adequately disinfected. Opposing casts were provided in 81% of cases (n = 116). Written instructions were described as being ‘clear’ in 31% of cases (n = 44). In 54% of cases (n = 76), the technician was asked to design the RPD. Based on the findings of this study, written communication for cobalt chromium RPDs by general dental practitioners is inadequate. This finding is in breach of relevant contemporary legal and ethical guidance. There are also concerns in relation to the fabrication process for this form of prosthesis, particularly, in relation to consideration of occlusal schemes.
Pseudomonas aeruginosa uses a cyclic‐di‐GMP‐regulated adhesin to reinforce the biofilm extracellular matrix
Authors: Borlee Bradley R. , Goldman Aaron D. , Murakami Keiji , Samudrala Ram , Wozniak Daniel J. , Parsek Matthew R.
Published: January 2010

Pseudomonas aeruginosa, the principal pathogen of cystic fibrosis patients, forms antibiotic‐resistant biofilms promoting chronic colonization of the airways. The extracellular (EPS) matrix is a crucial component of biofilms that provides the community multiple benefits. Recent work suggests that the secondary messenger, cyclic‐di‐GMP, promotes biofilm formation. An analysis of factors specifically expressed in P. aeruginosa under conditions of elevated c‐di‐GMP, revealed functions involved in the production and maintenance of the biofilm extracellular matrix. We have characterized one of these components, encoded by the PA4625 gene, as a putative adhesin and designated it cdrA. CdrA shares structural similarities to extracellular adhesins that belong to two‐partner secretion systems. The cdrA gene is in a two gene operon that also encodes a putative outer membrane transporter, CdrB. The cdrA gene encodes a 220 KDa protein that is predicted to be rod‐shaped protein harbouring a β‐helix structural motif. Western analysis indicates that the CdrA is produced as a 220 kDa proprotein and processed to 150 kDa before secretion into the extracellular medium. We demonstrated that cdrAB expression is minimal in liquid culture, but is elevated in biofilm cultures. CdrAB expression was found to promote biofilm formation and auto‐aggregation in liquid culture. Aggregation mediated by CdrA is dependent on the Psl polysaccharide and can be disrupted by adding mannose, a key structural component of Psl. Immunoprecipitation of Psl present in culture supernatants resulted in co‐immunoprecipitation of CdrA, providing additional evidence that CdrA directly binds to Psl. A mutation in cdrA caused a decrease in biofilm biomass and resulted in the formation of biofilms exhibiting decreased structural integrity. Psl‐specific lectin staining suggests that CdrA either cross‐links Psl polysaccharide polymers and/or tethers Psl to the cells, resulting in increased biofilm structural stability. Thus, this study identifies a key protein structural component of the P. aeruginosa EPS matrix.
The molecular mechanism of mitochondria autophagy in yeast
Authors: Kanki Tomotake , Klionsky Daniel J.
Published: January 2010

Mitochondria are critical for supplying energy to the cell, but during catabolism this organelle also produces reactive oxygen species that can cause oxidative damage. Accordingly, quality control of mitochondria is important to maintain cellular homeostasis. It has been assumed that autophagy is the pathway for mitochondrial recycling, and that the selective degradation of mitochondria via autophagy (mitophagy) is the primary mechanism for mitochondrial quality control, although there is little experimental evidence to support this idea. Recent studies in yeast identified several mitophagy‐related genes and have uncovered components involved in the molecular mechanism and regulation of mitophagy. Similarly, studies of Parkinson disease and reticulocyte maturation reveal that Parkin and Nix, respectively, are required for mitophagy in mammalian cells, and these analyses have revealed important physiological roles for mitophagy. Here, we review the current knowledge on mitophagy, in particular on the molecular mechanism and regulation of mitophagy in yeast. We also discuss some of the differences between yeast and mammalian mitophagy.
N‐glycosylation in Archaea: on the coordinated actions of Haloferax volcanii AglF and AglM
Authors: Yurist‐Doutsch Sophie , Magidovich Hilla , Ventura Valeria V. , Hitchen Paul G. , Dell Anne , Eichler Jerry
Published: January 2010

Like Eukarya and Bacteria, Archaea are also capable of performing N‐glycosylation. In the halophilic archaeon Haloferax volcanii, N‐glycosylation is mediated by the products of the agl gene cluster. In the present report, this gene cluster was expanded to include an additional sequence, aglM, shown to participate in the biosynthesis of hexuronic acids contained within a pentasaccharide decorating the S‐layer glycoprotein, a reporter H. volcanii glycoprotein. In response to different growth conditions, changes in the transcription profile of aglM mirrored changes in the transcription profiles of aglF, aglG and aglI, genes encoding confirmed participants in the H. volcanii N‐glycosylation pathway, thus offering support to the hypothesis that in H. volcanii, N‐glycosylation serves an adaptive role. Following purification, biochemical analysis revealed AglM to function as a UDP‐glucose dehydrogenase. In a scoupled reaction with AglF, a previously identified glucose‐1‐phosphate uridyltransferase, UDP‐glucuronic acid was generated from glucose‐1‐phosphate and UTP in a NAD+‐dependent manner. These experiments thus represent the first step towards in vitro reconstitution of the archaeal N‐glycosylation process.
Effect of epidural dexmedetomidine on intraoperative awareness and post‐operative pain after one‐lung ventilation
Authors: ELHAKIM M. , ABDELHAMID D. , ABDELFATTACH H. , MAGDY H. , ELSAYED A. , ELSHAFEI M.
Published: January 2010

Background: During combined general and regional anaesthesia, it is difficult to use autonomic signs to assess whether wakefulness is suppressed adequately. We compared the effects of a dexmedetomidine–bupivacaine mixture with plain bupivacaine for thoracic epidural anaesthesia on intraoperative awareness and analgesic benefits, when combined with superficial isoflurane anaesthesia (<0.05 maximum alveolar concentration) in patients undergoing thoracic surgery with one‐lung ventilation (OLV).

Methods: Fifty adult male patients were randomly assigned to receive either epidural dexmedetomidine 1 μg/kg with bupivacaine 0.5% (group D) or bupivacaine 0.5% alone (group B) after induction of general anaesthesia. Gasometric, haemodynamic and bispectral index values were recorded. Post‐operative verbal rating score for pain and observer's assessment of alertness/sedation scale were determined by a blinded observer.

Results: Dexmedetomidine reduced the use of supplementary fentanyl during surgery. Patients in group B consumed more analgesics and had higher pain scores after operation than patients of group D. The level of sedation was similar between the two groups in the ICU. Two patients (8%) in group B reported possible intraoperative awareness. There was a limited decrease in PaO2 at OLV in group D compared with group B (P<0.05).

Conclusion: In thoracic surgery with OLV, the use of epidural dexmedetomidine decreases the anaesthetic requirements significantly, prevents awareness during anaesthesia and improves intraoperative oxygenation and post‐operative analgesia.
Global and right ventricular end‐diastolic volumes correlate better with preload after correction for ejection fraction
Authors: MALBRAIN M. L. N. G. , DE POTTER T. J. R. , DITS H. , REUTER D. A.
Published: January 2010

Background: Volumetric monitoring with right ventricular end‐diastolic volume indexed (RVEDVi) and global end‐diastolic volume indexed (GEDVi) is increasingly being suggested as a superior preload indicator compared with the filling pressures central venous pressure (CVP) or the pulmonary capillary wedge pressure (PCWP). However, static monitoring of these volumetric parameters has not consistently been shown to be able to predict changes in cardiac index (CI). The aim of this study was to evaluate whether a correction of RVEDVi and GEDVi with a measure of the individual contractile reserve, assessed by right ventricular ejection fraction (RVEF) and global ejection fraction, improves the ability of RVEDVi and GEDVi to monitor changes in preload over time in critically ill patients.

Methods: Hemodynamic measurements, both by pulmonary artery and by transcardiopulmonary thermodilution, were performed in 11 mechanically ventilated medical ICU patients. Correction of volumes was achieved by normalization to EF deviation from normal EF values in an exponential fashion. Data before and after fluid administration were obtained in eight patients, while data before and after diuretics were obtained in seven patients.

Results: No correlation was found between the change in cardiac filling pressures (ΔCVP, ΔPCWP) and ΔCI (R2 0.01 and 0.00, respectively). Further, no correlation was found between ΔRVEDVi or ΔGEDVi and ΔCI (R2 0.10 and 0.13, respectively). In contrast, a significant correlation was found between ΔRVEDVi corrected to RVEF (ΔcRVEDVi) and ΔCI (R2 0.64), as well as between ΔcGEDVi and ΔCI (R2 0.59). An increase in the net fluid balance with +844 ± 495 ml/m2 resulted in a significant increase in CI of 0.5 ± 0.3 l/min/m2; however, only ΔcRVEDVi (R2 0.58) and ΔcGEDVi (R2 0.36) correlated significantly with ΔCI. Administration of diuretics resulting in a net fluid balance of −942 ± 658 ml/m2 caused a significant decrease in CI with 0.7 ± 0.5 l/min/m2; however, only ΔcRVEDVi (R2 0.80) and ΔcGEDVi (R2 0.61) correlated significantly with ΔCI.

Conclusion: Correction of volumetric preload parameters by measures of ejection fraction improved the ability of these parameters to assess changes in preload over time in this heterogeneous group of critically ill patients.
Comparison of the incidence and severity of cough after alfentanil and remifentanil injection
Authors: CHO H. B. , KWAK H. J. , PARK S. Y. , KIM J. Y.
Published: January 2010

Background: Intravenous administration of fentanyl derivatives can induce cough paradoxically. This study examined the incidence and severity of cough after a bolus of alfentanil and remifentanil.

Methods: Four hundred and sixty‐five patients, aged 18–70 years, were allocated randomly to three groups to receive alfentanil 10 μg/kg, remifentanil 1 μg/kg or an equal volume of 0.9% saline intravenously over 10 s. Any episode of cough was classified as coughing and graded as mild (1–2), moderate (3–4) or severe (5 or more).

Results: The overall incidence of cough was higher in the opioid groups than in the saline group. The remifentanil group [39/150 patients; 26.0% (95% CI, 19.6–33.6%)] showed a higher incidence than the alfentanil group [11/152 patients; 7.2% (95% CI, 0.4–12.6%)] (P<0.001). There was no significant difference in the severity of cough between the alfentanil group and the remifentanil group.

Conclusion: This study demonstrated that equipotent boluses of alfentanil and remifentanil induced coughing, even though the incidence of cough after alfentanil administration was lower than that after remifentanil administration.
Mixed venous oxygen saturation is a prognostic marker after surgery for aortic stenosis
Authors: HOLM J. , HÅKANSON R.E. , VÁNKY F. , SVEDJEHOLM R.
Published: January 2010

Background: Adequate monitoring of the hemodynamic state is essential after cardiac surgery and is vital for medical decision making, particularly concerning hemodynamic management. Unfortunately, commonly used methods to assess the hemodynamic state are not well documented with regard to outcome. Mixed venous oxygen saturation (SvO2) was therefore investigated after cardiac surgery.

Methods: Detailed data regarding mortality were available on all patients undergoing aortic valve replacement for isolated aortic stenosis during a 5‐year period in the southeast region of Sweden (n=396). SvO2 was routinely measured on admission to the intensive care unit (ICU) and registered in a database. A receiver operating characteristics (ROC) analysis of SvO2 in relation to post‐operative mortality related to cardiac failure and all‐cause mortality within 30 days was performed.

Results: The area under the curve (AUC) was 0.97 (95% CI 0.96–1.00) for mortality related to cardiac failure (P=0.001) and 0.76 (95% CI 0.53–0.99) for all‐cause mortality (P=0.011). The best cutoff for mortality related to cardiac failure was SvO2 53.7%, with a sensitivity of 1.00 and a specificity of 0.94. The negative predictive value was 100%. The best cutoff for all‐cause mortality was SvO2 58.1%, with a sensitivity of 0.75 and a specificity of 0.84. The negative predictive value was 99.4%. Post‐operative morbidity was also markedly increased in patients with a low SvO2.

Conclusion: SvO2, on admission to the ICU after surgery for aortic stenosis, demonstrated excellent sensitivity and specificity for post‐operative mortality related to cardiac failure and a fairly good AUC for all‐cause mortality, with an excellent negative predictive value.
Is nerve stimulation needed during an ultrasound‐guided lateral sagittal infraclavicular block?
Authors: GÜRKAN Y. , TEKIN M. , ACAR S. , SOLAK M. , TOKER K.
Published: January 2010

Background: The objective of the study was to evaluate the influence of ultrasound (US) guidance alone vs. neurostimulation (NS) and US (NSUS) guidance techniques on block performance time and block success rate for the lateral sagittal infraclavicular block (LSIB).

Methods: In a randomized and prospective manner, 110 adult patients scheduled for distal upper limb surgery were allocated to the US or the NSUS groups. In the US group, a local anesthetic (LA) was administered only with US guidance to produce a ‘U’‐shaped distribution around the axillary artery. In the NSUS group, LA was administered under US guidance only after electrolocation of one of the median, ulnar or radial nerve‐type responses. A total of 30 ml of LA (10 ml of levobupivacaine 5 mg/ml and 20 ml of lidocaine 20 mg/ml) was administered in both groups. Sensory block was tested at 10 min intervals for 30 min. Successful block was defined as analgesia or anesthesia of all five nerves distal to the elbow.

Results: Block success rate was 94.5% in both groups. Block performance time was significantly shorter in the US than the NSUS group (157 ± 50 vs. 230 ± 104 s) (P=0.000). Block onset time was similar in both groups (12.5 ± 4.8 in the US vs. 12.8 ± 5.4 min in the NSUS groups). There were two arterial punctures in the NSUS group.

Conclusions: During LSIB performance US guidance alone produces block success rate identical to both US and NS guidance yet with a shorter block performance time.