bluuebunny/crossref_metadata_2025 huggingface dataset:
Scanning ion conductance microscopy: a convergent high-resolution technology for multi-parametric analysis of living cardiovascular cells
Authors: Miragoli Michele , Moshkov Alexey , Novak Pavel , Shevchuk Andrew , Nikolaev Viacheslav O. , El-Hamamsy Ismail , Potter Claire M. F. , Wright Peter , Kadir S.H. Sheikh Abdul , Lyon Alexander R. , Mitchell Jane A. , Chester Adrian H. , Klenerman David , Lab Max J. , Korchev Yuri E. , Harding Sian E. , Gorelik Julia
Published: February 2011

Cardiovascular diseases are complex pathologies that include alterations of various cell functions at the levels of intact tissue, single cells and subcellular signalling compartments. Conventional techniques to study these processes are extremely divergent and rely on a combination of individual methods, which usually provide spatially and temporally limited information on single parameters of interest. This review describes scanning ion conductance microscopy (SICM) as a novel versatile technique capable of simultaneously reporting various structural and functional parameters at nanometre resolution in living cardiovascular cells at the level of the whole tissue, single cells and at the subcellular level, to investigate the mechanisms of cardiovascular disease. SICM is a multimodal imaging technology that allows concurrent and dynamic analysis of membrane morphology and various functional parameters (cell volume, membrane potentials, cellular contraction, single ion-channel currents and some parameters of intracellular signalling) in intact living cardiovascular cells and tissues with nanometre resolution at different levels of organization (tissue, cellular and subcellular levels). Using this technique, we showed that at the tissue level, cell orientation in the inner and outer aortic arch distinguishes atheroprone and atheroprotected regions. At the cellular level, heart failure leads to a pronounced loss of T-tubules in cardiac myocytes accompanied by a reduction in Z-groove ratio. We also demonstrated the capability of SICM to measure the entire cell volume as an index of cellular hypertrophy. This method can be further combined with fluorescence to simultaneously measure cardiomyocyte contraction and intracellular calcium transients or to map subcellular localization of membrane receptors coupled to cyclic adenosine monophosphate production. The SICM pipette can be used for patch-clamp recordings of membrane potential and single channel currents. In conclusion, SICM provides a highly informative multimodal imaging platform for functional analysis of the mechanisms of cardiovascular diseases, which should facilitate identification of novel therapeutic strategies.
Evidence of strategic periodicities in collective conflict dynamics
Authors: DeDeo Simon , Krakauer David , Flack Jessica
Published: February 2011

We analyse the timescales of conflict decision-making in a primate society. We present evidence for multiple, periodic timescales associated with social decision-making and behavioural patterns. We demonstrate the existence of periodicities that are not directly coupled to environmental cycles or known ultraridian mechanisms. Among specific biological and socially defined demographic classes, periodicities span timescales between hours and days. Our results indicate that these periodicities are not driven by exogenous or internal regularities but are instead driven by strategic responses to social interaction patterns. Analyses also reveal that a class of individuals, playing a critical functional role, policing, have a signature timescale of the order of 1 h. We propose a classification of behavioural timescales analogous to those of the nervous system, with high frequency, or
α
-scale, behaviour occurring on hour-long scales, through to multi-hour, or
β
-scale, behaviour, and, finally
γ
periodicities observed on a timescale of days.
A highly distributed Bragg stack with unique geometry provides effective camouflage for Loliginid squid eyes
Authors: Holt Amanda L. , Sweeney Alison M. , Johnsen Sönke , Morse Daniel E.
Published: February 2011

Cephalopods possess a sophisticated array of mechanisms to achieve camouflage in dynamic underwater environments. While active mechanisms such as chromatophore patterning and body posturing are well known, passive mechanisms such as manipulating light with highly evolved reflectors may also play an important role. To explore the contribution of passive mechanisms to cephalopod camouflage, we investigated the optical and biochemical properties of the silver layer covering the eye of the California fishery squid,Loligo opalescens. We discovered a novel nested-spindle geometry whose correlated structure effectively emulates a randomly distributed Bragg reflector (DBR), with a range of spatial frequencies resulting in broadband visible reflectance, making it a nearly ideal passive camouflage material for the depth at which these animals live. We used the transfer-matrix method of optical modelling to investigate specular reflection from the spindle structures, demonstrating that a DBR with widely distributed thickness variations of high refractive index elements is sufficient to yield broadband reflectance over visible wavelengths, and that unlike DBRs with one or a few spatial frequencies, this broadband reflectance occurs from a wide range of viewing angles. The spindle shape of the cells may facilitate self-assembly of a random DBR to achieve smooth spatial distributions in refractive indices. This design lends itself to technological imitation to achieve a DBR with wide range of smoothly varying layer thicknesses in a facile, inexpensive manner.
Modelling the spread of infectious salmon anaemia among salmon farms based on seaway distances between farms and genetic relationships between infectious salmon anaemia virus isolates
Authors: Aldrin M. , Lyngstad T. M. , Kristoffersen A. B. , Storvik B. , Borgan Ø. , Jansen P. A.
Published: February 2011

Infectious salmon anaemia (ISA) is an important infectious disease in Atlantic salmon farming causing recurrent epidemic outbreaks worldwide. The focus of this paper is on tracing the spread of ISA among Norwegian salmon farms. To trace transmission pathways for the ISA virus (ISAV), we use phylogenetic relationships between virus isolates in combination with space–time data on disease occurrences. The rate of ISA infection of salmon farms is modelled stochastically, where seaway distances between farms and genetic distances between ISAV isolates from infected farms play prominent roles. The model was fitted to data covering all cohorts of farmed salmon and the history of all farms with ISA between 2003 and summer 2009. Both seaway and genetic distances were significantly associated with the rate of ISA infection. The fitted model predicts that the risk of infection from a neighbourhood infectious farm decreases with increasing seaway distance between the two farms. Furthermore, for a given infected farm with a given ISAV genotype, the source of infection is significantly more likely to be ISAV of a small genetic distance than of moderate or large genetic distances. Nearly half of the farms with ISA in the investigated period are predicted to have been infected by an infectious farm in their neighbourhood, whereas the remaining half of the infected farms had unknown sources. For many of the neighbourhood infected farms, it was possible to point out one or a few infectious farms as the most probable sources of infection. This makes it possible to map probable infection pathways.
Modelling behavioural contagion
Authors: House Thomas
Published: February 2011

The last decade has seen much work on quantitative understanding of human behaviour, with online social interaction offering the possibility of more precise measurement of behavioural phenomena than was previously possible. A parsimonious model is proposed that incorporates several observed features of behavioural contagion not seen in existing epidemic model schemes, leading to metastable behavioural dynamics.
The limits of collaboration: Robert Hooke, Christopher Wren and the designing of the monument to the great fire of London
Authors: Walker Matthew F.
Published: February 2011

This article showcases my recent research into the professional relationship between Christopher Wren and Robert Hooke, two of the early Royal Society's most prominent scientists and architects. There has been a recent tendency in architectural history to see Wren and Hooke as informal architectural collaborators, the co-designers of several important works in post-fire London. These include Greenwich Royal Observatory, the rebuilt parish churches in the City of London and, most prominently, the recently restored Monument to the Great Fire of London. In this article I argue that this reading of their relationship is a problematic one, ultimately dependent on an equally problematic account of their friendship. To do so I explore Wren and Hooke's professional relationship with regard to the Monument. I show, using new evidence, that their roles in the designing of the column have been misunderstood and that the final design can now be attributed to Hooke alone. Rather than being informal collaborators, Wren and Hooke did not stray from their duties as Royal Surveyor and City Surveyor, respectively, and Wren's contribution to the commissioning and designing of the Monument was as a consultant and ratifier only. In this respect their professional relationship as architects differed from their work as Royal Society scientists, in which informal collaboration was not only permissible but also encouraged. Overall, this conclusion has significant implications for our understanding of Wren and Hooke's careers as architects and sheds new light on one of early modern England's most important buildings.
Phase separation and surface segregation in ceria–zirconia solid solutions
Authors: Grau-Crespo Ricardo , de Leeuw Nora H. , Hamad Said , Waghmare Umesh V.
Published: February 2011

Using a combination of density functional theory calculations and statistical mechanics, we show that a wide range of intermediate compositions of ceria–zirconia solid solutions are thermodynamically metastable with respect to phase separation into Ce-rich and Zr-rich oxides. We estimate that the maximum equilibrium concentration of Zr in CeO
2
at 1373 K is approximately 2 per cent, and therefore, equilibrated samples with higher Zr content are expected to exhibit heterogeneity at the atomic scale. We also demonstrate that in the vicinity of the (111) surface, cation redistribution at high temperatures will occur with significant Ce enrichment of the surface, which we attribute to the more covalent character of Zr–O bonds compared with Ce–O bonds. Although the kinetic barriers for cation diffusion normally prevent the decomposition/segregation of ceria–zirconia solid solutions in typical catalytic applications, the separation behaviour described here can be expected to occur in modern three-way catalytic converters, where very high temperatures are reached.
The intrinsic interfacial structure of ionic surfactant monolayers at water–oil and water–vapour interfaces
Authors: Martínez Hector , Chacón Enrique , Tarazona Pedro , Bresme Fernando
Published: February 2011

Using computer simulations, we investigate the interfacial structure of sodium dodecyl sulphate (SDS) monolayers adsorbed at the water surface and water–oil interfaces. Using an algorithm that removes the averaging effect of the capillary waves, we obtain a detailed view of the solvation structure of water around the monolayer. We investigate surface concentrations between 45 and 33 Å
2
per surfactant, which are near experimental conditions corresponding to the critical micellar concentration and the formation of Newton black films. The surfactants induce a layering structure in water, which disappears at approximately 1 nm from the monolayer plane. The water molecules exhibit a preferred orientation with the dipoles pointing towards the monolayer. The orientational order decays slowly, but it does not influence the hydrogen bond structure of water, which is significantly disrupted in the interfacial region only. These structural changes are qualitatively the same in SDS–water and oil–SDS–water interfaces. In the latter case, we find a small degree of penetration of oil in the monolayer (between 0.2 and 0.25 molecules per SDS). This small penetration has a measurable effect on the monolayer, which increases its thickness by approximately 10 per cent. The bending modulus of the SDS monolayers is of the order of the thermal energy,
k
B
T
.
Relative equilibria of point vortices and the fundamental theorem of algebra
Authors: Aref Hassan
Published: February 2011

Relative equilibria of identical point vortices may be associated with a generating polynomial that has the vortex positions as its roots. A formula is derived that relates the first and second derivatives of this polynomial evaluated at a vortex position. Using this formula, along with the fundamental theorem of algebra, one can sometimes write a general polynomial equation. In this way, results about relative equilibria of point vortices may be proved in a compact and elegant way. For example, the classical result of Stieltjes, that if the vortices are on a line they must be situated at the zeros of the
N
th Hermite polynomial, follows easily. It is also shown that if in a relative equilibrium the vortices are all situated on a circle, they must form a regular
N
-gon. Several other results are proved using this approach. An ordinary differential equation for the generating polynomial when the vortices are situated on two perpendicular lines is derived. The method is extended to vortex systems where all the vortices have the same magnitude but may be of either sign. Derivations of the equation of Tkachenko for completely stationary configurations and its extension to translating relative equilibria are given.
War as a moral imperative (not just practical politics by other means)
Authors: Ginges Jeremy , Atran Scott
Published: February 2011

We present findings from one survey and five experiments carried out in the USA, Nigeria and the Middle East showing that judgements about the use of deadly intergroup violence are strikingly insensitive to quantitative indicators of success, or to perceptions of their efficacy. By demonstrating that judgements about the use of war are bounded by rules of deontological reasoning and parochial commitment, these findings may have implications for understanding the trajectory of violent political conflicts. Further, these findings are compatible with theorizing that links the evolution of within-group altruism to intergroup violence.
Learning to count begins in infancy: evidence from 18 month olds' visual preferences
Authors: Slaughter Virginia , Itakura Shoji , Kutsuki Aya , Siegal Michael
Published: February 2011

We used a preferential looking paradigm to evaluate infants' preferences for correct versus incorrect counting. Infants viewed a video depicting six fish. In the correct counting sequence, a hand pointed to each fish in turn, accompanied by verbal counting up to six. In the incorrect counting sequence, the hand moved between two of the six fish while there was still verbal counting to six, thereby violating the one-to-one correspondence principle of correct counting. Experiment 1 showed that Australian 18 month olds, but not 15 month olds, significantly preferred to watch the correct counting sequence. In experiment 2, Australian infants' preference for correct counting disappeared when the count words were replaced by beeps or by Japanese count words. In experiment 3, Japanese 18 month olds significantly preferred the correct counting video only when counting was in Japanese. These results show that infants start to acquire the abstract principles governing correct counting prior to producing any counting behaviour.
A trade-off between current and future sex allocation revealed by maternal energy budget in a small mammal
Authors: Rutkowska Joanna , Koskela Esa , Mappes Tapio , Speakman John R.
Published: February 2011

Sex-allocation theories generally assume differential fitness costs of raising sons and daughters. Yet, experimental confirmation of such costs is scarce and potential mechanisms are rarely addressed. While the most universal measure of physiological costs is energy expenditure, only one study has related the maternal energy budget to experimentally controlled offspring sex. Here, we experimentally test this in the bank vole (Myodes glareolus) by simultaneously manipulating the litter's size and sex ratio immediately after birth. Two weeks after manipulation, when mothers were at the peak of lactation and were pregnant with concurrent litters, we assessed their energy budget. We found that maternal food consumption and daily energy expenditure increased with the size of the litters being lactated. Importantly, the effects of offspring sex on energy budget depended on the characteristics of the simultaneously gestating litters. Specifically, the mothers nursing all-male litters and concurrently pregnant with male-biased litters had the highest energy expenditure. These had consequences for the next generation, as size of female offspring from the concurrent pregnancy of these mothers was compromised. Our study attests a higher cost of sons, consequently leading to a lower investment in them, and reveals the significance of offspring sex in moulding the trade-off between current and future maternal investment.
Sea to sky: impacts of residual salmon-derived nutrients on estuarine breeding bird communities
Authors: Field Rachel D. , Reynolds John D.
Published: February 2011

Pacific salmon (
Oncorhynchus
spp.) returning to streams around the North Pacific Rim provide a nutrient subsidy to these ecosystems. While many species of animals feed directly on salmon carcasses each autumn, salmon-derived nutrients can also be stored in coastal habitats throughout the year. The effects of this storage legacy on vertebrates in other seasons are not well understood, especially in estuaries, which can receive a large portion of post-spawning salmon nutrients. We examine the effects of residual salmon-derived nutrients, forest habitats and landscape features on summer breeding birds in estuary forests. We compared models containing environmental variables and combined chum (
Oncorhynchus keta
) and pink (
Oncorhynchus gorbuscha
) salmon biomass to test predictions concerning bird density and diversity. We discovered that total bird, insectivore, golden-crowned kinglet and Pacific wren densities and Shannon's diversity in the summer were strongly predicted by salmon biomass in the autumn. For most metrics, this relationship approaches an asymptote beyond 40 000 kg of salmon biomass. Foliage height diversity, watershed catchment area and estuary area were also important predictors of avian communities. Our study suggests that the legacy of salmon nutrients influences breeding bird density and diversity in estuaries that vary across a wide gradient of spawning salmon biomass.
Connectivity dominates larval replenishment in a coastal reef fish metapopulation
Authors: Saenz-Agudelo Pablo , Jones Geoffrey P. , Thorrold Simon R. , Planes Serge
Published: February 2011

Direct estimates of larval retention and connectivity are essential to understand the structure and dynamics of marine metapopulations, and optimize the size and spacing of reserves within networks of marine-protected areas (MPAs). For coral reef fishes, while there are some empirical estimates of self-recruitment at isolated populations, exchange among sub-populations has been rarely quantified. Here, we used microsatellite DNA markers and a likelihood-based parentage analysis to assess the relative magnitude of self-recruitment and exchange among eight geographically distinct sub-populations of the panda clownfishAmphiprion polymnusalong 30 km of coastline near Port Moresby, Papua New Guinea. In addition, we used an assignment/exclusion test to identify immigrants arriving from genetically distinct sources. Overall, 82 per cent of the juveniles were immigrants while 18 per cent were progeny of parents genotyped in our focal metapopulation. Of the immigrants, only 6 per cent were likely to be genetically distinct from the focal metapopulation, suggesting most of the connectivity is among sub-populations from a rather homogeneous genetic pool. Of the 18 per cent that were progeny of known adults, two-thirds dispersed among the eight sub-populations and only one-third settled back into natal sub-populations. Comparison of our data with previous studies suggested that variation in dispersal distances is likely to be influenced by the geographical setting and spacing of sub-populations.
Structural support, not insulation, is the primary driver for avian cup-shaped nest design
Authors: Heenan Caragh B. , Seymour Roger S.
Published: February 2011

The nest micro-environment is a widely studied area of avian biology, however, the contribution of nest conductance (the inverse of insulation) to the energetics of the incubating adult and offspring has largely been overlooked. Surface-specific thermal conductance (W °C
−1
cm
−2
) has been related to nest dimensions, wall porosity, height above-ground and altitude, but the most relevant measure is total conductance (
G
, W °C
−1
). This study is the first to analyse conductance allometrically with adult body mass (
M
, g), according to the form
G
=
aM
b
. We propose three alternative hypotheses to explain the scaling of conductance. The exponent may emerge from: heat loss scaling (
M
0.48
) in which
G
scales with the same exponent as thermal conductance of the adult bird, isometric scaling (
M
0.33
) in which nest shape is held constant as parent mass increases, and structural scaling (
M
0.25
) in which nests are designed to support a given adult mass. Data from 213 cup-shaped nests, from 36 Australian species weighing 8–360 g, show conductance is proportional to
M
0.25
. This allometric exponent is significantly different from those expected for heat loss and isometric scaling and confirms the hypothesis that structural support for the eggs and incubating parent is the primary factor driving nest design.
Unified effects of aggregation reveal larger prey groups take longer to find
Authors: Ioannou Christos C. , Bartumeus Frederic , Krause Jens , Ruxton Graeme D.
Published: February 2011

Previous work has suggested that larger groups of prey are more conspicuous to predators. However, this ignores that prey populations are finite. As groups get larger they become fewer, hence the encounter rate between predator and prey decreases with prey aggregation. Here, we present a two-dimensional model based on visual angle to unify these encounter and conspicuousness effects of aggregation. With experimental support using three-spined sticklebacks (Gasterosteus aculeatusL.), searching for chironomid larvae, we demonstrate that the increase in visual angle with increasing group size is outweighed by its corresponding decrease as the groups become fewer and thus further away from the searching predator. The net effect is that prey are found with more difficulty when they aggregate, giving an additional anti-predatory benefit to group living rather than a cost.
Regulation of alternative splicing by the core spliceosomal machinery
Authors: Saltzman Arneet L. , Pan Qun , Blencowe Benjamin J.
Published: February 2011

Alternative splicing (AS) plays a major role in the generation of proteomic diversity and in gene regulation. However, the role of the basal splicing machinery in regulating AS remains poorly understood. Here we show that the core snRNP (small nuclear ribonucleoprotein) protein SmB/B′ self-regulates its expression by promoting the inclusion of a highly conserved alternative exon in its own pre-mRNA that targets the spliced transcript for nonsense-mediated mRNA decay (NMD). Depletion of SmB/B′ in human cells results in reduced levels of snRNPs and a striking reduction in the inclusion levels of hundreds of additional alternative exons, with comparatively few effects on constitutive exon splicing levels. The affected alternative exons are enriched in genes encoding RNA processing and other RNA-binding factors, and a subset of these exons also regulate gene expression by activating NMD. Our results thus demonstrate a role for the core spliceosomal machinery in controlling an exon network that appears to modulate the levels of many RNA processing factors.
AphA and LuxR/HapR reciprocally control quorum sensing in vibrios
Authors: Rutherford Steven T. , van Kessel Julia C. , Shao Yi , Bassler Bonnie L.
Published: February 2011

Bacteria cycle between periods when they perform individual behaviors and periods when they perform group behaviors. These transitions are controlled by a cell–cell communication process called quorum sensing, in which extracellular signal molecules, called autoinducers (AIs), are released, accumulate, and are synchronously detected by a group of bacteria. AI detection results in community-wide changes in gene expression, enabling bacteria to collectively execute behaviors such as bioluminescence, biofilm formation, and virulence factor production. In this study, we show that the transcription factor AphA is a master regulator of quorum sensing that operates at low cell density (LCD) inVibrio harveyiandVibrio cholerae. In contrast, LuxR (V. harveyi)/HapR (V. cholerae) is the master regulator that operates at high cell density (HCD). At LCD, redundant small noncoding RNAs (sRNAs) activate production of AphA, and AphA and the sRNAs repress production of LuxR/HapR. Conversely, at HCD, LuxR/HapR repressesaphA. This network architecture ensures maximal AphA production at LCD and maximal LuxR/HapR production at HCD. Microarray analyses reveal that 300 genes are regulated by AphA at LCD inV. harveyi, a subset of which is also controlled by LuxR. We propose that reciprocal gradients of AphA and LuxR/HapR establish the quorum-sensing LCD and HCD gene expression patterns, respectively.
Cardiac muscle regeneration: lessons from development
Authors: Mercola Mark , Ruiz-Lozano Pilar , Schneider Michael D.
Published: February 2011

The adult human heart is an ideal target for regenerative intervention since it does not functionally restore itself after injury yet has a modest regenerative capacity that could be enhanced by innovative therapies. Adult cardiac cells with regenerative potential share gene expression signatures with early fetal progenitors that give rise to multiple cardiac cell types, suggesting that the evolutionarily conserved regulatory networks that drive embryonic heart development might also control aspects of regeneration. Here we discuss commonalities of development and regeneration, and the application of the rich developmental biology heritage to achieve therapeutic regeneration of the human heart.
Is contaminated unrecorded alcohol a health problem in the European Union? A review of existing and methodological outline for future studies
Authors: Lachenmeier Dirk W. , Schoeberl Kerstin , Kanteres Fotis , Kuballa Thomas , Sohnius Eva‐Maria , Rehm Jürgen
Published: February 2011

Aims  Some European countries with high levels of unrecorded alcohol consumption have anomalously high rates of death attributable to liver cirrhosis. Hepatotoxic compounds in illegally produced spirits may be partly responsible. Based on a review of the evidence on the chemical composition and potential harm from unrecorded alcohol, the Alcohol Measures for Public Health Research Alliance (AMPHORA) project's methodology for identifying, analysing and toxicologically evaluating such alcohols is provided.

Methods  A computer‐assisted literature review concentrated on unrecorded alcohol. Additionally, we refer to our work in the capacity of governmental alcohol control authority and a number of pilot studies.

Results  The risk‐oriented identification of substances resulted in the following compounds probably posing a public health risk in unrecorded alcohol: ethanol, methanol, acetaldehyde, higher alcohols, heavy metals, ethyl carbamate, biologically active flavourings (e.g. coumarin) and diethyl phthalate. Suggestions on a sampling strategy for identifying unrecorded alcohol that may be most prone to contamination include using probable distribution points such as local farmers and flea markets for selling surrogate alcohol (including denatured alcohol) to focusing on lower socio‐economic status or alcohol‐dependent individuals, and selecting home‐produced fruit spirits prone to ethyl carbamate contamination.

Conclusions  Standardized guidelines for the chemical and toxicological evaluation of unrecorded alcohol that will be used in a European‐wide sampling and are applicable globally are provided. These toxicological guidelines may also be used by alcohol control laboratories for recorded alcohol products, and form a scientific foundation for establishing legislative limits.
A new AMPHORA: an introduction to the project Alcohol Measures for Public Health Research Alliance
Authors: Gual Antoni , Anderson Peter
Published: February 2011

The AMPHORA Project is a 4 years project funded by the 7th Framework Programme of the European Commission which aims to contribute with new evidence on scarcely explored or unexplored areas of alcohol consumption and alcohol‐related harm in Europe. In this introductory article we describe the background of the Project and its main features. The research areas covered by AMPHORA are wide and diverse. Some of the most relevant are: an update on European epidemiological data; the definition of standard common indicators of alcohol consumption and harm; the measurement of the strength of alcohol policies; the study of contextual determinants of alcohol consumption, the analysis of the impact of marketing on youth; the availability of treatments at a European level; and two areas of harm reduction (contamination of illegal or surrogate alcohols and the reduction of harm in drinking venues).
Identification of alternatively activated macrophages in new‐onset paediatric and adult immunoglobulin A nephropathy: potential role in mesangial matrix expansion
Authors: Ikezumi Yohei , Suzuki Toshiaki , Karasawa Tamaki , Hasegawa Hiroya , Yamada Takeshi , Imai Naofumi , Narita Ichiei , Kawachi Hiroshi , Polkinghorne Kevan R , Nikolic‐Paterson David J , Uchiyama Makoto
Published: February 2011

Ikezumi Y, Suzuki T, Karasawa T, Hasegawa H, Yamada T, Imai N, Narita I, Kawachi H, Polkinghorne K R, Nikolic‐Paterson D J & Uchiyama M (2011) Histopathology 58, 198–210 Identification of alternatively activated macrophages in new‐onset paediatric and adult immunoglobulin A nephropathy: potential role in mesangial matrix expansion

Aims:  New onset of the clinical symptoms of immunoglobulin A (IgA) nephropathy (IgAN) manifests with proliferative glomerular lesions in children, whereas adults exhibit mesangial matrix expansion and interstitial fibrosis. Alternatively, activated (M2) macrophages have been implicated in promoting tissue fibrosis in some settings. Therefore, the aim of this study was to investigate whether M2 macrophages are present in new‐onset IgAN and if they are related to pathological differences between paediatric and adult disease.

Methods and results:  Biopsy specimens from paediatric (<10 years, n = 14; >12 years, n = 15) and adult (n = 27) IgAN showed a significant infiltrate of CD68+ macrophages. M2 macrophages, identified by CD163 or CD204 expression, were detected in glomeruli and the interstitium, being more prominent in adults versus young children. CD163+ and CD204+ macrophages were present in areas of fibrosis containing myofibroblasts, and double staining showed that CD163+ cells produced the profibrotic molecule, connective tissue growth factor. In young children, total CD68+ macrophages, but not M2 macrophages, correlated with glomerular hypercellularity. In contrast, in adults and older children, mesangial matrix expansion correlated with M2 macrophages but not with the total CD68+ macrophage infiltrate.

Conclusions:  Alternatively activated M2 macrophages are present in new‐onset paediatric and adult IgAN, and this population may promote the development of fibrotic lesions.
Differential expression of the nuclear receptors farnesoid X receptor (FXR) and pregnane X receptor (PXR) for grading dysplasia in patients with Barrett’s oesophagus
Authors: van de Winkel Anouk , van Zoest Katinka P M , van Dekken Herman , Moons Leon M G , Kuipers Ernst J , van der Laan Luc J W
Published: February 2011

van de Winkel A, van Zoest K P M, van Dekken H, Moons L M G, Kuipers E J & van der Laan L J W  (2011) Histopathology58, 246–253 Differential expression of the nuclear receptors farnesoid X receptor (FXR) and pregnane X receptor (PXR) for grading dysplasia in patients with Barrett’s oesophagus

Aims:  To investigate expression of nuclear receptors farnesoid X receptor (FXR) and pregnane X receptor (PXR) as a diagnostic tool to improve grading of dysplasia in Barrett’s oesophagus patients.

Methods and results:  Immunostaining was analysed on a total of 192 biopsy samples of 22 Barrett’s patients with no dysplasia (ND), 17 with low‐grade dysplasia (LGD), 20 high‐grade dysplasia (HGD) and 24 with adenocarcinoma (AC). Nuclear FXR expression was observed in 15 of 22 (68%) ND cases versus none of 19 HGD; 3 of 17 (18%); LGD; 5 of 60 (8%) patients with AC (P < 0.001). FXR expression was highly specific for non‐dysplastic tissue. Nuclear PXR was expressed in 16 of 20 (80%) HGD cases versus two of 16 (13%) LGD cases (PPV 89%). Upon examining adjacent tissue taken from HGD and AC patients, PXR expression was high in samples of all tissue types.

Conclusions:  Nuclear receptors are expressed differentially during neoplastic progression, with FXR positivity being useful to distinguish ND from dysplasia and AC. PXR nuclear expression is able to separate HGD from LGD and ND. The combination of FXR and PXR also appears to have diagnostic and possibly prognostic value, but future prospective studies are required to investigate their predictive power for neoplastic progression in Barret’s oesophagus.
Homo‐ and heterotypic cell–cell contacts in Merkel cells and Merkel cell carcinomas: heterogeneity and indications for cadherin switching
Authors: Werling Anna M , Doerflinger Yvette , Brandner Johanna M , Fuchs Franca , Becker Jürgen C , Schrama David , Kurzen Hjalmar , Goerdt Sergij , Peitsch Wiebke K
Published: February 2011

Werling A M, Doerflinger Y, Brandner J M, Fuchs F, Becker J C, Schrama D, Kurzen H, Goerdt S & Peitsch W K (2011) Histopathology58, 286–303 Homo‐ and heterotypic cell–cell contacts in Merkel cells and Merkel cell carcinomas: heterogeneity and indications for cadherin switching

Aims:  Merkel cell carcinomas (MCCs) are rare but aggressive tumours associated recently with Merkel cell polyomavirus (MCV). As development and progression of several types of carcinomas can be promoted by changes in cell adhesion proteins, the aim of this study was to examine homo‐ and heterotypic cell contacts of Merkel cells and MCCs.

Methods and results:  Merkel cells of healthy glabrous epidermis and 52 MCCs were analysed by double‐label immunostaining, immunofluorescence and confocal microscopy. Merkel cells were connected to keratinocytes by E‐ and P‐cadherin, desmoglein 2 and desmocollin 2. In contrast, the vast majority of MCCs (90%) contained N‐cadherin, but only 67% and 65% contained E‐ and P‐cadherin, respectively. Interestingly, P‐cadherin was absent significantly more frequently in lymph node metastases than in primary tumours and by trend in more advanced clinical stages. Moreover, major subsets of MCCs synthesized desmoglein 2 and, surprisingly, tight junction proteins. No significant differences were observed upon stratification for MCV DNA, detected in 84% of tumours by real‐time polymerase chain reaction.

Conclusions:  Assuming that MCCs originate from Merkel cells, our data indicate a switch from E‐ and P‐cadherin to N‐cadherin during tumorigenesis. Whether the unexpected heterogeneity of junctional proteins can be exploited for prognostic and therapeutic purposes will need to be examined.
Microfasciculation: a morphological pattern in leprosy nerve damage
Authors: Antunes Sérgio L G , Medeiros Mildred F , Corte‐Real Suzana , Jardim Márcia R , Nery José A da Costa , Hacker Mariana A V B , Valentim Vânia da Costa , Amadeu Thaís Porto , Sarno Euzenir N
Published: February 2011

Antunes S L G, Medeiros M F, Corte‐Real S, Jardim M R, da Costa Nery J A, Hacker M A V B, da Costa Valentim V, Amadeu T P & Sarno E N (2011) Histopathology58, 304–311

Microfasciculation: a morphological pattern in leprosy nerve damage

Aims:  To study Microfasciculation, a perineurial response found in neuropathies, emphasizing its frequency, detailed morphological characteristics and biological significance in pure neural leprosy (PNL), post‐treatment leprosy neuropathy (PTLN) and non‐leprosy neuropathies (NLN).

Methods and results:  Morphological characteristics of microfascicles were examined via histological staining methods, immunohistochemical expression of neural markers and transmission electronmicroscopy. The detection of microfasciculation in 18 nerve biopsy specimens [12 PNL, six PTLN but not in the NLN group, was associated strongly with perineurial damage and the presence of a multibacillary inflammatory process in the nerves, particularly in the perineurium. Immunoreactivity to anti‐S100 protein, anti‐neurofilament, anti‐nerve growth receptor and anti‐myelin basic protein immunoreactivity was found within microfascicles. Ultrastructural examination of three biopsies showed that fibroblast–perineurial cells were devoid of basement membrane despite perineurial‐like NGFr immunoreactivity. Morphological evidence demonstrated that multipotent pericytes from inflammation‐activated microvessels could be the origin of fibroblast–perineurial cells.

Conclusions:  A microfasciculation pattern was found in 10% of leprosy‐affected nerves. The microfascicles were composed predominantly of unmyelinated fibres and denervated Schwann cells (SCs) surrounded by fibroblast–perineurial cells. This pattern was found more frequently in leprosy nerves with acid‐fast bacilli (AFB) and perineurial damage while undergoing an inflammatory process. Further experimental studies are necessary to elucidate microfascicle formation.
In situ hybridization detection of homeobox genes reveals distinct expression patterns in oral squamous cell carcinomas
Authors: Libório Tatiana N , Acquafreda Thais , Matizonkas‐Antonio Luciana F , Silva‐Valenzuela Maria G , Ferraz Alberto R , Nunes Fabio D
Published: February 2011

Libório T N, Acquafreda T, Matizonkas‐Antonio L F, Silva‐Valenzuela M G, Ferraz A R & Nunes F D (2011) Histopathology 58, 225–233 In situ hybridization detection of homeobox genes reveals distinct expression patterns in oral squamous cell carcinomas

Aims:  To analyse the expression of three homeobox genes (HOXA7, PITX1 and PRRX1) in oral squanous cell carcinomas (OSCC) and the relationship of such expression to certain distinct histopathological features of OSCC and in comparison to adjacent non‐neoplastic epithelium (NT).

Methods and results:  Digoxigenin‐labelled riboprobes that are specific for each homeobox gene were generated and in situ hybridization was carried out on frozen sections. In NT samples, HOXA7 and PITX1 transcripts were found more frequently in all epithelial layers, while PRRX1 was expressed in the basal layer. With OSCC samples, expression of the three genes was associated with all histological features. However, the HOXA7 and PITX1 signals were more intense in sheets and nests and PRRX1 in small nests and isolated cells.

Conclusion:  HOXA7, PIXT1 and PRRX1 homeobox genes have different patterns of expression in OSCC depending on its histological features.
CD151 expression can predict cancer progression in clear cell renal cell carcinoma
Authors: Yoo Seong H , Lee Kyoungbun , Chae Ji Y , Moon Kyung C
Published: February 2011

Yoo S H, Lee K, Chae J Y & Moon K C (2011) Histopathology 58, 191–197 CD151 expression can predict cancer progression in clear cell renal cell carcinoma

Aims:  CD151 is known to be implicated in cancer progression and metastasis. The aim was to evaluate the expression of CD151 in clear cell renal cell carcinoma (CCRCC) and to assess its prognostic significance.

Methods and results:  The expression of CD151 was evaluated in 489 cases of CCRCC by immunohistochemistry. Immunoreactivity was classified into four categories (minimal, 0–10% positive cells; focal, 10–50% positive cells; diffuse moderate, >50% positive cells with moderate staining intensity; diffuse strong, >50% positive cells with strong staining). To determine the statistical significance of CD151 expression in CCRCC, all cases were divided into two groups based on their CD151 expression level: a CD151‐low group (n = 257; minimal and focal) and a CD151‐high group (n = 232; diffuse). Expression of CD151 was correlated positively with pT, pN, pM categories, pathological tumour–node–metastasis (pTNM) stage, nuclear grade, tumour size and patient’s age. The CD151‐high group had significantly shorter cancer‐specific survival (P < 0.001) and progression‐free survival (P < 0.001) times. Furthermore, multivariate analysis showed that CD151 expression was an independent predictor for tumour progression in patients with CCRCC (P = 0.040).

Conclusions:  High CD151 expression is associated with advanced stage and high nuclear grade in CCRCC. CD151 is a prognostic marker for tumour progression in CCRCC patients.
Postoperative intra‐arterial methylene blue injection of colorectal cancer specimens increases the number of lymph nodes recovered
Authors: Törnroos Alexander , Shabo Ivan , Druvefors Bengt , Arbman Gunnar , Olsson Hans
Published: February 2011

Törnroos A, Shabo I, Druvefors B, Arbman G & Olsson H (2011) Histopathology58, 408–413 Postoperative intra‐arterial methylene blue injection of colorectal cancer specimens increases the number of lymph nodes recovered

Aims:  To determine the possible advantage of intra‐arterial injection of methylene blue with a view to improving lymph node recovery in postoperative examination of colorectal cancer specimens.

Methods and results:  Thirty‐two colorectal cancer specimens were assigned randomly to either dissection with intra‐arterial methylene blue injection or to routine dissection (without methylene blue injection). Immediately postoperatively, the specimens in the staining group were injected intra‐arterially with methylene blue dye. The two procedures were compared with respect to the number of lymph nodes recovered. The number of recovered lymph nodes was significantly higher in the intra‐arterial methylene blue injection group than in the group investigated with routine procedures (P  < 0.0001).

Conclusion:  The intra‐arterial methylene blue injection method is fairly easy to use postoperatively and increases significantly the number of lymph nodes recovered in colorectal cancer specimens.
Diagnosis of testicular carcinoma in situ‘(intratubular and microinvasive)’ seminoma and embryonal carcinoma using direct enzymatic alkaline phosphatase reactivity on frozen histological sections
Authors: Stoop Hans , Kirkels Wim , Dohle Gert R , Gillis Ad J M , den Bakker Michael A , Biermann Katharina , Oosterhuis Wolter , Looijenga Leendert H J
Published: February 2011

Stoop H, Kirkels W, Dohle G R, Gillis A J M, den Bakker M A, Biermann K, Oosterhuis W & Looijenga L H J (2011) Histopathology58, 440–446 Diagnosis of testicular carcinoma in situ‘(intratubular and microinvasive)’ seminoma and embryonal carcinoma using direct enzymatic alkaline phosphatase reactivity on frozen histological sections

Aims:  Testis‐sparing surgery might benefit quality of life, but can only be applied with histological examination for the presence of invasive germ cell tumour components, and the precursor carcinoma in situ (CIS). Currently, diagnosis is based on paraffin‐embedded tissue, therefore a delay in further surgery is mainly unavoidable. The aim was to develop an intraoperative assessment technique using alkaline phosphatase as a marker.

Methods and results:  A total of 4093 snap‐frozen samples and matched paraffin‐embedded tissue of 1500 patients were included. Besides standard haematoxylin and eosin (H&E) staining, the direct enzymatic alkaline phosphatase reactivity (dAP) test (duration 15 min) was applied on frozen sections, while H&E and immunohistochemistry for detection of OCT3/4, α‐fetoprotein, human chorionic gonadotrophin (hCG) and cytokeratin was performed on the paraffin‐embedded slides. Endothelial cells served as control for the dAP test. Positive staining was found in all CIS (n = 965), seminoma (n = 1035) and embryonal carcinoma (n = 584), either intratubular, microinvasive or invasive. Differentiated non‐seminomas (n = 1238) showed variable staining. No staining was identified in spermatocytic seminomas (n = 5), testicular lymphomas (n = 42), testicular rhabdomyosarcomas (n = 7), Leydig cell tumours (n = 31), Sertoli‐cell‐only nodules (n = 4), (epi) dermoid cyst (n = 16), normal testicular parenchyma (n = 116), testicular torsion (n = 32) and inflammation of the epididymis (n = 19). The dAP test results matched H&E‐stained parallel sections, as well paraffin‐embedded tissue analysis, including immunohistochemistry.

Conclusions:  The dAP test is an informative, reproducible and easy tool to diagnose CIS, (intratubular and microinvasive) seminoma and embryonal carcinoma on frozen tissue sections, being of great value in the context of sparing surgery.
Mitochondrial and nuclear DNA sequences reveal recent divergence in morphologically indistinguishable petrels
Authors: WELCH ANDREANNA J. , YOSHIDA ALLISON A. , FLEISCHER ROBERT C.
Published: February 2011

Often during the process of divergence, genetic markers will only gradually obtain the signal of isolation. Studies of recently diverged taxa utilizing both mitochondrial and nuclear data sets may therefore yield gene trees with differing levels of phylogenetic signal as a result of differences in coalescence times. However, several factors can lead to this same pattern, and it is important to distinguish between them to gain a better understanding of the process of divergence and the factors driving it. Here, we employ three nuclear intron loci in addition to the mitochondrial Cytochrome b gene to investigate the magnitude and timing of divergence between two endangered and nearly indistinguishable petrel taxa: the Galapagos (GAPE) and Hawaiian (HAPE) petrels (Pterodroma phaeopygia and P. sandwichensis). Phylogenetic analyses indicated reciprocal monophyly between these two taxa for the mitochondrial data set, but trees derived from the nuclear introns were unresolved. Coalescent analyses revealed effectively no migration between GAPE and HAPE over the last 100 000 generations and that they diverged relatively recently, approximately 550 000 years ago, coincident with a time of intense ecological change in both the Galapagos and Hawaiian archipelagoes. This indicates that recent divergence and incomplete lineage sorting are causing the difference in the strength of the phylogenetic signal of each data set, instead of insufficient variability or ongoing male‐biased dispersal. Further coalescent analyses show that gene flow is low even between islands within each archipelago suggesting that divergence may be continuing at a local scale. Accurately identifying recently isolated taxa is becoming increasingly important as many clearly recognizable species are already threatened by extinction.