bluuebunny/crossref_metadata_2025 huggingface dataset:
Global change and species interactions in terrestrial ecosystems
Authors: Tylianakis Jason M. , Didham Raphael K. , Bascompte Jordi , Wardle David A.
Published: October 2008

The main drivers of global environmental change (CO2 enrichment, nitrogen deposition, climate, biotic invasions and land use) cause extinctions and alter species distributions, and recent evidence shows that they exert pervasive impacts on various antagonistic and mutualistic interactions among species. In this review, we synthesize data from 688 published studies to show that these drivers often alter competitive interactions among plants and animals, exert multitrophic effects on the decomposer food web, increase intensity of pathogen infection, weaken mutualisms involving plants, and enhance herbivory while having variable effects on predation. A recurrent finding is that there is substantial variability among studies in both the magnitude and direction of effects of any given GEC driver on any given type of biotic interaction. Further, we show that higher order effects among multiple drivers acting simultaneously create challenges in predicting future responses to global environmental change, and that extrapolating these complex impacts across entire networks of species interactions yields unanticipated effects on ecosystems. Finally, we conclude that in order to reliably predict the effects of GEC on community and ecosystem processes, the greatest single challenge will be to determine how biotic and abiotic context alters the direction and magnitude of GEC effects on biotic interactions.
Universal and species‐specific bacterial ‘fungiphiles’ in the mycospheres of different basidiomycetous fungi
Authors: Warmink J. A. , Nazir R. , Van Elsas J. D.
Published: October 2008

In previous work, several bacterial groups that show a response to fruiting bodies (the mycosphere) of the ectomycorrhizal fungus Laccaria proxima were identified. We here extend this work to a broader range of fungal fruiting bodies sampled at two occasions. PCR‐DGGE analyses showed clear effects of the mycosphere of diverse fungi on the total bacterial and Pseudomonas communities in comparison with those in the corresponding bulk soil. The diversities of the Pseudomonas communities increased dramatically in most of the mycospheres tested, which contrasted with a decrease of the diversity of the total bacterial communities in these habitats. The data also indicated the existence of universal (i.e. Pseudomonas poae, P. lini, P. umsongensis, P. corrugata, P. antarctica and Rahnella aquatilis) as well as specific (i.e. P. viridiflava and candidatus Xiphinematobacter americani) fungiphiles, defined as bacteria adapted to the mycospheres of, respectively, three or more or just one fungal species. The selection of such fungiphiles was shown to be strongly related to their capacities to use particular carbonaceous compounds, as evidenced using principal components analyses of BIOLOG‐based substrate utilization tests. The differentiating compounds, i.e. l‐arabinose, l‐leucine, m‐inositol, m‐arabitol, d‐mannitol and d‐trehalose, were tentatively linked to compounds known to occur in mycosphere exudates.
Relationship between β‐cell mass and diabetes onset
Authors: Matveyenko A. V. , Butler P. C.
Published: October 2008

Regulation of blood glucose concentrations requires an adequate number of β‐cells that respond appropriately to blood glucose levels. β‐Cell mass cannot yet be measured in humans in vivo, necessitating autopsy studies, although both pre‐ and postmorbid changes may confound this approach. Autopsy studies report deficits in β‐cell mass ranging from 0 to 65% in type 2 diabetes (T2DM), and ∼70–100% in type 1 diabetes (T1DM), and, when evaluated, increased β‐cell apoptosis in both T1DM and T2DM. A deficit of β‐cell mass of ∼50% in animal studies leads to impaired insulin secretion (when evaluated directly in the portal vein) and induction of insulin resistance. We postulate three phases for diabetes progression. Phase 1: selective β‐cell cytotoxicity (autoimmune in T1DM, unknown in T2DM) leading to impaired β‐cell function and gradual loss of β‐cell mass through apoptosis. Phase 2: decompensation of glucose control when the pattern of portal vein insulin secretion is sufficiently impaired to cause hepatic insulin resistance. Phase 3: adverse consequences of glucose toxicity accelerate β‐cell dysfunction and insulin resistance. The relative contribution of β‐cell loss versus β‐cell dysfunction to diabetes onset remains an area of controversy. However, because cytotoxicity sufficient to induce β‐cell apoptosis predictably disturbs β‐cell function, it is naïve to attempt to distinguish the relative contributions of these linked processes to diabetes onset.
Restoring a functional β‐cell mass in diabetes
Authors: Pipeleers D. , Chintinne M. , Denys B. , Martens G. , Keymeulen B. , Gorus F.
Published: October 2008

Type 1 and type 2 diabetes have often been presented as disease forms that profoundly differ in the presence and pathogenic significance of a reduced β‐cell mass. We review evidence indicating that the β‐cell mass in type 1 diabetes is usually not decreased by at least 90% at clinical onset, and remains often detectable for years after diagnosis at age above 15 years. Clinical and experimental evidence also exists for a reduced β‐cell mass in type 2 diabetes where it can be the cause for and/or the consequence of dysregulated β‐cell functions. With β‐cell mass defined as number of β‐cells, these views face the limitation of insufficient data and methods for human organs. Because β‐cells can occur under different phenotypes that vary with age and with environmental conditions, we propose to use the term functional β‐cell mass as an assessment of a β‐cell population by the number of β‐cells and their phenotype or functional state. Assays exist to measure functional β‐cell mass in isolated preparations. We selected a glucose‐clamp test to evaluate functional β‐cell mass in type 1 patients at clinical onset and in type 1 recipients following intraportal islet cell transplantation. Comparison of the data with those in non‐diabetic controls helps targeting and monitoring of therapeutic interventions.
Non‐invasive detection of transplanted pancreatic islets
Authors: Medarova Z. , Moore A.
Published: October 2008

Type 1 diabetes (insulin‐dependent, IDDM) results in immune‐mediated destruction of pancreatic β cells, which leads to a deficiency in insulin secretion and as a result, to hyperglycaemia. Keeping blood glucose levels under tight control represents the most effective way either to prevent the onset or to reduce the progression of the chronic complications of IDDM. At present, pancreatic islet transplantation is emerging as the most promising clinical modality, which can stop diabetes progression without increasing the incidence of hypoglycaemic events. Although early results of clinical trials using the Edmonton Protocol and its variations are very encouraging, it is still unclear how long the islets will survive and how often the transplantation procedure will be successful. In order to monitor transplantation efficiency and graft survival, reliable non‐invasive imaging methods are critically needed. If such methods are introduced clinically, essential information regarding the location, function and viability of transplanted islets can be obtained repeatedly and non‐invasively. This review will focus on the latest advancements in the field of in vivo imaging of islet transplantation and describe various islet labelling and imaging techniques. In addition, we will critically look into limitations and obstacles currently present on the way to successful clinical implementation of this approach.
VMAT2 quantitation by PET as a biomarker for β‐cell mass in health and disease
Authors: Freeby M. , Goland R. , Ichise M. , Maffei A. , Leibel R. , Harris P.
Published: October 2008

The common pathology underlying both type 1 and type 2 diabetes (T1DM and T2DM) is insufficient β‐cell mass (BCM) to meet metabolic demands. An important impediment to the more rapid evaluation of interventions for both T1DM and T2DM lack of biomarkers of pancreatic BCM. A reliable means of monitoring the mass and/or function of β‐cells would enable evaluation of the progression of diabetes as well as the monitoring of pharmacologic and other interventions. Recently, we identified a biomarker of BCM that is quantifiable by positron emission tomography (PET). PET is an imaging technique which allows for non‐invasive measurements of radioligand uptake and clearance, is sensitive in the pico‐ to nanomolar range and of which the results can be deconvoluted into measurements of receptor concentration. For BCM estimates, we have identified VMAT2 (vesicular monoamine transporter type 2) as a biomarker and [11C] DTBZ (dihydrotetrabenazine) as the transporter’s ligand. VMAT2 is highly expressed in β‐cells of the human pancreas relative to other cells of the endocrine and exocrine pancreas. Thus measurements of [11C] DTBZ in the pancreas provide an indirect measurement of BCM. Here we summarize our ongoing efforts to validate the clinical utility of this non‐invasive approach to real‐time BCM measurements
Efforts to develop methods for in vivo evaluation of the native β‐cell mass
Authors: Schneider S.
Published: October 2008

Visualization and quantification of the native β‐cell mass in vivo in humans appear to be important in the study of the natural course of diabetes, and in ongoing trials aimed at preserving β‐cell mass in patients with diabetes. This cannot be done by biopsy sampling, and therefore there is a great need for development of a non‐invasive method. This article discusses the principle theoretical requirements for reaching this goal. In addition, it provides an overview of tracer probes, which have been examined as potential β‐cell mass imaging agents in the past. Finally, some future perspectives are discussed.
An examination of β‐cell function measures and their potential use for estimating β‐cell mass
Authors: Kahn S. E. , Carr D. B. , Faulenbach M. V. , Utzschneider K. M.
Published: October 2008

A characteristic and dominant feature of type 2 diabetes is a reduction in β‐cell function that is associated with a decrease in β‐cell volume. A decline in the first‐phase insulin response following intravenous glucose administration can be demonstrated as the fasting glucose concentration increases. This response is completely absent before the glucose threshold that defines diabetes has been reached and at a time when β‐cells are clearly still present, implying that a functional β‐cell lesion has to exist independent of β‐cell loss. Surgical or chemical reductions of up to 65% of β‐cell volume demonstrate that functional adaptation of the normal β‐cell prevents a rise in fasting glucose or reduction in first‐phase insulin response. However, the ability of glucose to potentiate the β‐cell’s response to non‐glucose secretagogues is reduced and is more closely associated with the reduction in β‐cell volume. The future, in terms of prevention and treatment of type 2 diabetes, lies in the ability to prevent and revert both β‐cell loss and dysfunction. However, until β‐cell volume can be quantified reliably and non‐invasively, we will need to rely on the ability of glucose to potentiate insulin release as the best surrogate estimate of the number of β‐cells.
β‐cell function assessment from modelling of oral tests: an effective approach
Authors: Mari A. , Ferrannini E.
Published: October 2008

The quantitative study of β‐cell function has relied on mathematical models for almost 40 years. During the last decades, the initial elaborate models have been simplified with the aim of obtaining mathematical methods suitable for the assessment of β‐cell function in an individual from an intravenous test. In more recent times, modelling methods have been proposed for analysing oral glucose tolerance tests or meal tests. In this review, we describe these methods with particular emphasis on an approach we have developed. We discuss the relevance of potentiation of insulin secretion in an oral glucose test, which our model has reintroduced after the historical models. We provide evidence on the validity of the method and illustrate significant applications. We emphasize the importance of quantifying β‐cell function through multiple indices and highlight how our approach has provided new insight on the relationships between β‐cell function and insulin sensitivity and on the role of β‐cell function in glucose intolerance and diabetes.
Differential expression of cell cycle proteins during ageing of pancreatic islet cells
Authors: Hinault C. , Hu J. , Maier B. F. , Mirmira R. G. , Kulkarni R. N.
Published: October 2008

One of the major challenges for developmental biologists and investigators in the field of diabetes over the last few decades has been to dissect the origin of pancreatic endocrine cells and to accurately understand the mechanisms that regulate islet cell regeneration. While significant advances have been made recently, there continues to be a paucity of knowledge regarding the growth factor signalling pathways that directly regulate the proteins involved in islet cell cycle control. We will discuss recent work in these areas and provide insights from our studies into age‐dependent alterations in the expression of growth factor signalling proteins and cell cycle proteins in islet cells.
Determinants of pancreatic β‐cell regeneration
Authors: Khalaileh A. , Gonen‐Gross T. , Magenheim J. , Nir T. , Porat S. , Salpeter S. , Stolovich‐Rain M. , Swisa A. , Weinberg N. , Dor Y.
Published: October 2008

Recent studies have revealed a surprising plasticity of pancreatic β‐cell mass. β‐cell mass is now recognized to increase and decrease in response to physiological demand, for example during pregnancy and in insulin‐resistant states. Moreover, we and others have shown that mice recover spontaneously from diabetes induced by killing of 70–80% of β‐cells, by β‐cell regeneration. The major cellular source for new β‐cells following specific ablation, as well as during normal homeostatic maintenance of adult β‐cells, is proliferation of differentiated β‐cells. More recently, it was shown that one form of severe pancreatic injury, ligation of the main pancreatic duct, activates a population of embryonic‐type endocrine progenitor cells, which can differentiate into new β‐cells. The molecular triggers for enhanced β‐cell proliferation during recovery from diabetes and for activation of embryonic‐type endocrine progenitors remain unknown and represent key challenges for future research. Taken together, recent data suggest that regenerative therapy for diabetes may be a realistic goal.
Can β‐cells be derived from exocrine pancreas?
Authors: Baeyens L. , Bouwens L.
Published: October 2008

A major goal of research aiming at improving islet cell replacement therapy is to find the most suitable progenitor cell type from which functional β‐cells can be generated in large numbers. Many possibilities have been raised, including β‐cells themselves, embryonic or adult stem cells and reprogramming of other cell types. Some of these progenitor types may be active or reside in a dormant state in adults in vivo, while others can be rather considered to be products of tissue engineering in vitro. Starting from the available pancreas organs from cadaveric donors, an attractive possibility is to reprogram acinar exocrine cells into β‐cells. Indeed, acinar cells isolated from adult rats display a pronounced plasticity in culture. After an initial step of dedifferentiation, they can be redirected to the β‐cell phenotype by adding agonists of the JAK2/STAT3 signalling pathway to the medium (epidermal growth factor and leukaemia inhibitory factor). The acinar cells that undergo exocrine‐to‐endocrine transdifferentiation first need to re‐express neurogenin‐3 and then need to escape inhibition by Notch signalling. The insulin‐expressing cells that are generated in this way are glucose‐regulated and can normalize glycaemia after transplantation into diabetic immunocompromised mice. It will now be important to translate these findings to human cells.
Insulitis in type 2 diabetes
Authors: Böni‐Schnetzler M. , Ehses J. A. , Faulenbach M. , Donath M. Y.
Published: October 2008

Islets of patients with type 2 diabetes have the feature of an inflammatory process reflected by the presence of cytokines, immune cells, β‐cell apoptosis, amyloid deposits and fibrosis. Indeed, β‐cells from patients with type 2 diabetes display inflammatory markers, including increased interleukin (IL)‐1β expression. Furthermore, increased islet‐associated macrophages are observed in human type 2 diabetic patients and in most animal models of diabetes. Importantly, increased numbers of macrophages are detectable very early in high fat–fed mice islets, before the onset of diabetes. These immune cells are most likely attracted by islet‐derived chemokines, produced in response to metabolic stress, and under the control of IL‐1β. It follows that modulation of intra‐islet inflammatory mediators, in particular IL‐1β, may prevent insulitis in type 2 diabetes and therefore presents itself as a possible causal therapy with disease‐modifying potential.
β‐cell development: the role of intercellular signals
Authors: Scharfmann R. , Duvillie B. , Stetsyuk V. , Attali M. , Filhoulaud G. , Guillemain G.
Published: October 2008

Understanding in detail how pancreatic endocrine cells develop is important for many reasons. From a scientific point of view, elucidation of such a complex process is a major challenge. From a more applied point of view, this may help us to better understand and treat specific forms of diabetes. Although a variety of therapeutic approaches are well validated, no cure for diabetes is available. Many arguments indicate that the development of new strategies to cure diabetic patients will require precise understanding of the way β‐cells form during development. This is obvious for a future cell therapy using β‐cells produced from embryonic stem cells. This also holds true for therapeutic approaches based on regenerative medicine. In this review, we summarize our current knowledge concerning pancreatic development and focus on the role of extracellular signals implicated in β‐cell development from pancreatic progenitors.
Fluorescence‐activated cell sorting purification of pancreatic progenitor cells
Authors: Sugiyama T. , Kim S. K.
Published: October 2008

Here we review progress on isolation and characterization of progenitor cells in the pancreas. We discuss advantages and current limitations of experiments with purified pancreatic cells, and areas where future growth in our understanding is needed to advance experiments in pancreas biology based on cell purification.
Cell therapy for type 2 diabetes: is it desirable and can we get it?
Authors: Halban P. A.
Published: October 2008

The functional mass of β‐cells is decreased in type 2 diabetes. Replacing missing β‐cells or triggering their regeneration may thus allow for improved treatment of type 2 diabetes, to the extent that this is combined with therapy for improved insulin sensitivity. Although progress has been made in deriving β‐cell‐like cells from stem or precursor cells in vitro, these cannot yet be obtained in sufficient quantities or well enough differentiated to envisage their therapeutic use in β‐cell replacement therapy. Likewise, our very limited understanding of β‐cell regeneration in adult man does not yet allow for development of a valid strategy for kick‐starting such a process in individuals with type 2 diabetes, whether by bona fide neogenesis or self‐replication of existing β‐cells. Regardless of how β‐cell mass is restored in type 2 diabetes, it will be important to prevent any renewed decrease thereafter. Current understanding suggests that islet inflammation as well as signals from (insulin‐resistant/inflamed) adipose tissue and skeletal muscle contribute towards decreased β‐cell mass in type 2 diabetes. It will likely be important to protect newly formed or implanted β‐cells from these negative influences to ensure their long‐term survival.
Pancreatic β‐cell mass in European subjects with type 2 diabetes
Authors: Rahier J. , Guiot Y. , Goebbels R. M. , Sempoux C. , Henquin J. C.
Published: October 2008

Decreases in both β‐cell function and number can contribute to insulin deficiency in type 2 diabetes. Here, we quantified the β‐cell mass in pancreas obtained at autopsy of 57 type 2 diabetic (T2D) and 52 non‐diabetic subjects of European origin. Sections from the body and tail were immunostained for insulin. The β‐cell mass was calculated from the volume density of β‐cells (measured by point‐counting methods) and the weight of the pancreas. The pancreatic insulin concentration was measured in some of the subjects. β‐cell mass increased only slightly with body mass index (BMI). After matching for BMI, the β‐cell mass was 41% (BMI < 25) and 38% (BMI 26–40) lower in T2D compared with non‐diabetic subjects, and neither gender nor type of treatment influenced these differences. β‐cell mass did not correlate with age at diagnosis but decreased with duration of clinical diabetes (24 and 54% lower than controls in subjects with <5 and >15 years of overt diabetes respectively). Pancreatic insulin concentration was 30% lower in patients. In conclusion, the average β‐cell mass is about 39% lower in T2D subjects compared with matched controls. Its decrease with duration of the disease could be a consequence of diabetes that, with further impairment of insulin secretion, contributes to the progressive deterioration of glucose homeostasis. We do not believe that the small difference in β‐cell mass observed within 5 years of onset could cause diabetes in the absence of β‐cell dysfunction.
Brachytherapy for prostate cancer: is the pretreatment prostate volume important?
Authors: Meyer Jon‐Paul , Bell C. Richard W. , Elwell Christine , Kunkler Roger B.
Published: October 2008

OBJECTIVE

To prospectively determine the effect of prostate volume on lower urinary tract symptoms (LUTS) in terms of changes in the International Prostate Symptom Score (IPSS), and to determine whether prostate volume affects the retention rate after brachytherapy, as there is concern that patients with larger prostates might develop more troublesome LUTS after brachytherapy.

PATIENTS AND METHODS

We prospectively identified 100 consecutive patients who had brachytherapy for prostate cancer, using a real‐time three‐dimensional seed implantation technique, at one institution. At each follow‐up review the IPSS was recorded. To determine the effect of prostate volume on the IPSS after treatment the patients were divided into two groups according to prostate volume at brachytherapy (<50 and ≥50 mL).

RESULTS

The median patient age was 62 years, the overall median prostate volume was 42 mL and the median intraoperative D90 was 190 Gy. The pretreatment IPSS was 4 and 8 for the <50 and ≥50 mL groups, respectively, and at 3 months after brachytherapy the median IPSS increased to 18 and 20 for the two groups, respectively. Eleven patients went into acute retention of urine after brachytherapy (six in the ≥50 mL group).

CONCLUSIONS

This study shows that patients with prostates of ≥50 mL have an IPSS comparable with those who have prostates of <50 mL. Large prostates should not be considered an exclusion criterion when an intraoperative planning technique is used for brachytherapy.
High nuclear Livin expression is a favourable prognostic indicator in renal cell carcinoma
Authors: Haferkamp Axel , Bedke Jens , Vetter Caroline , Pritsch Maria , Wagener Nina , Buse Stephan , Crnkovic‐Mertens Irena , Hoppe‐Seyler Karin , Macher‐Goeppinger Stephan , Hoppe‐Seyler Felix , Autschbach Frank , Hohenfellner Markus
Published: October 2008

OBJECTIVES

To assess the protein expression of Livin, an apoptosis inhibitor, in renal cell carcinoma (RCC) and to determine its prognostic relevance.

PATIENTS AND METHODS

Immunohistochemical staining for Livin was performed in tissue microarrays (TMAs), including tumour tissue cores, from patients with RCC who had undergone renal surgery. In 682 TMAs cytoplasmatic staining intensity and nuclear staining quantity were evaluated, and the association of Livin expression with progression‐free survival (PFS) and cancer‐specific survival (CSS) was analysed with a multivariate Cox regression model.

RESULTS

Over a median (range) follow‐up of 5.2 (0–16.1) years, 204 patients (28%) had died from their disease. The CSS rates at 1 and 5 years for the entire cohort was 88% and 71%. Cytoplasmatic Livin staining was absent in 516 (76%) specimens; staining was positive in 166 (24%) specimens. Weak nuclear Livin staining (≤25%) was present in 571 (84%) specimens, strong nuclear staining (26–100%) in 111 (16%). In multivariate analysis, high (>25%) nuclear Livin expression was a favourable independent predictor of PFS and CSS even after adjusting for tumour stage, Fuhrman grade, age, sex and Karnofsky severity rating. Cytoplasmatic Livin expression did not offer additional prognostic information.

CONCLUSION

High nuclear Livin expression is a favourable independent predictor of PFS and CSS in patients with RCC.
Transvesical robotic radical prostatectomy
Authors: Desai Mihir M. , Aron Monish , Berger Andre , Canes David , Stein Robert , Haber Georges‐Pascal , Kamoi Kazumi , Crouzet Sebastien , Sotelo Rene , Gill Inderbir S.
Published: October 2008

OBJECTIVE

To report the technical feasibility of performing transvesical robotic radical prostatectomy (TRRP) in a cadaver.

MATERIALS AND METHODS

TRRP was performed in two fresh male cadavers (prostate volume 46 and 30 mL). In the first procedure we used four laparoscopic transvesical trocars and in the second a single‐port device was placed percutaneously into the bladder. Pneumovesicum was established in both cases and the da Vinci‐S robotic system (Intuitive Surgical, Sunnyvale, CA, USA) was used for the TRRP. All steps of the procedure, including dissection of the seminal vesicles and vas deferens, ligation of prostatic pedicles, release of neurovascular bundles, apical dissection, urethral transection, and urethro‐vesical anastomosis, were done transvesically and robotically. Real time transrectal ultrasonography monitoring was used in the first cadaver.

RESULTS

Both procedures were technically successful transvesically with no need for additional ports or conversion to standard laparoscopy. The operative duration for the multi‐port procedure was 3 h and for the single‐port procedure was 4.2 h. Clashing of the da Vinci arms was the primary technical difficulty with the single‐port procedure, but did not occur in the multi‐port procedure.

CONCLUSIONS

TRRP under pneumovesicum is technically feasible using multiple‐port or a single‐port approach in the cadaver. The clinical application of this novel approach is imminent. Further refinement of technique and instruments might lead to an increasing role of percutaneous intraluminal surgery in various surgical disciplines.
Can nomograms be superior to other prediction tools?
Authors: Shariat Shahrokh F. , Capitanio Umberto , Jeldres Claudio , Karakiewicz Pierre I.
Published: October 2008

Accurate estimates of the likelihood of treatment success, complications and long‐term morbidity are essential for counselling and informed decision‐making in patients with urological malignancies. Accurate risk estimates are also required for clinical trial design, to ensure homogeneous patient distribution. Nomograms, risk groupings, artificial neural networks (ANNs), probability tables, and classification and regression tree (CART) analyses represent the available decision aids that can be used within these tasks. We critically reviewed available decision aids (nomograms, risk groupings, ANNs, probability tables and CART analyses) and compared their ability to predict the outcome of interest. Of the available decision aids, nomograms provide individualized evidence‐based and highly accurate risk estimates that facilitate management‐related decisions. We suggest the use of nomograms for the purpose of evidence‐based, individualized decision‐making.
Effects of climate variation on the abundance and distribution of flamingos in the Galápagos Islands
Authors: Vargas F. H. , Barlow S. , Hart T. , Jimenez‐Uzcátegui G. , Chavez J. , Naranjo S. , Macdonald D. W.
Published: October 2008

El Niño Southern Oscillation events have been associated with large fluctuations in seabird and landbird populations of the Galápagos Islands. We reveal different effects of climatic variation on the abundance and distribution of a waterbird, as illustrated by the flamingosPhoenicopterus ruberliving in saline coastal lagoons of the arid Galápagos environment. Using time series analyses [autoregressive integrated moving average (ARIMA)] to model the temporal variations in abundance, we found significant correlations between rainfall, lagoon water level (LWL), lagoon temperature and flamingo abundance. Although these variables were good predictors of flamingo abundance, they explained <50% of the variance in monthly counts. During the strong El Niño event of 1982–1983, extreme rainfall resulted in an increase in LWLs (>300 mm above the long‐term mean) and a record decline in flamingo numbers. Monthly abundance of flamingos was lower, on average, during the rainy season (between January and May) when LWLs were above their seasonal mean. Flamingo abundance at the two lagoons on Isabela Island and those at ‘all other lagoons’ in the Archipelago showed a significant negative correlation. We infer that moderate reductions in the abundance of flamingos in the rainy season and significant temporary declines during El Niño events are explained by movements between lagoons within the Archipelago rather than by mortality. This illustrates the general principle that climate change may, without directly affecting population sizes, prompt adaptive behavioural changes with the potential to affect population biology.
Phylogeography of the white‐tailed mongoose (Herpestidae, Carnivora, Mammalia) based on partial sequences of the mtDNA control region
Authors: Dehghani R. , Wanntorp L. , Pagani P. , Källersjö M. , Werdelin L. , Veron G.
Published: October 2008

The phylogeography of the white‐tailed mongooseIchneumia albicaudais examined using phylogenetic analyses based on partial sequences of the mitochondrial control region. The phylogeny is used to: (1) Analyse the phylogeographic pattern ofI. albicauda; (2) discuss the existing delimitation of subspecies; (3) test if the coloration of the tail tip, generally white but occasionally black in West African specimens, is a species polymorphism or if it has phylogenetic significance. Our results suggest a north–south division within white‐tailed mongoose populations, and within the northern clade, we observe an east–west subdivision. This phylogenetic pattern is partly in concordance with the traditional division into six subspecies. The white‐tailed mongoose probably originated in southern Africa, from where it dispersed northwards and colonized eastern and western parts of Africa, as well as the Arabian Peninsula. Colour polymorphism observed in Western populations reflects variation at the individual level.
Foraging opportunities drive interspecific associations between rock kestrels and desert baboons
Authors: King A. J. , Cowlishaw G.
Published: October 2008

Interspecific associations can arise for varied reasons including reduced predation risk and improved foraging success. In the case of bird–primate associations, birds typically appear to follow primate groups to harvest insects flushed by primates' movements. However, while previous studies have linked temporal changes in bird–primate associations to environmental conditions, few have assessed the additional effects of bird activity patterns and primate group behaviour and none have disentangled their potentially interdependent effects. Here, we test the hypothesis that foraging opportunities can drive interspecific associations in a previously undescribed bird–primate association between rock kestrels Falco rupicolus and chacma baboons Papio ursinus in central Namibia. Data were collected from two baboon groups and associated kestrels using instantaneous scan sampling during full‐day follows over a 7‐month field period, and analysed using generalized linear mixed models. We found that kestrel associations with baboons vary with season, show diurnal cycles and are more frequent when the baboons are in open desert habitat, engaged in travel foraging and in a large group. These patterns are statistically independent and consistent with the hypothesis that the kestrel–baboon association is driven by the foraging opportunities acquired by the kestrels. As the baboons do not appear to gain any benefits nor incur any costs from the association, we conclude that the kestrels are likely to be commensal with the baboons.
Ecological and anthropogenic influences on space use by spotted hyaenas
Authors: Kolowski J. M. , Holekamp K. E.
Published: October 2008

Due to increasing human encroachment into the remaining habitat of many large carnivore species, there is an immediate need to understand the ecological and anthropogenic factors influencing carnivore space use decisions. In particular, knowledge of changes in space use in response to disturbance, and the costs associated with these changes, will be critical in guiding conservation efforts. To investigate the ecological factors influencing carnivore space use, we intensively radiotracked members of two large social groups (clans) of spotted hyaenasCrocuta crocutain the Masai Mara National Reserve, Kenya. In addition, we studied the influence of livestock grazing by comparing space use between two study clans that differed dramatically in exposure to grazing. Logistic regression modeling indicated that space use in the absence of livestock was most influenced by the location of the clan's communal den. However, hyaenas were also found to select shrubland, areas of high prey density, and proximity to seasonal streams. Movements of hyaenas exposed to livestock grazing were most influenced by vegetation type, with a strong avoidance of open grass plains. Den location and prey density had less influence on space use decisions in the disturbed than the undisturbed clan. Livestock distribution did not directly influence hyaena movements either during daytime, when livestock were present, or at night. We suggest that direct livestock avoidance was unnecessary due to the observed increased use of vegetative cover by hyaenas exposed to grazing livestock. The greater distances from the den, and from areas of high prey density at which hyaenas were found in disturbed than undisturbed areas indicates potential energetic costs incurred by disturbed hyaenas. Our results therefore suggest that reduced vegetative cover, as is often found outside protected areas, may result in more dramatic modifications of hyaena movements in the presence of livestock.
Nonphosphate‐Binding Effects of Sevelamer—Are They of Clinical Relevance?
Authors: Marangon Nicola , Lindholm Bengt , Stenvinkel Peter
Published: October 2008

Sevelamer is an ion‐exchanging resin that binds phosphate in the gut. Because it does so without increasing the calcium load, treatment with sevelamer may lead to less vascular calcification and better survival in chronic kidney disease patients. However, the results of available clinical studies have not been consistent; recent observations challenge the hypothesis that the extra calcium load inherent in calcium‐based phosphate binder therapy increases cardiovascular mortality by accelerating vascular calcification. This reemphasizes the fact that we still lack detailed understanding on the complex relationships between vascular calcification, bone metabolism, vascular disease and outcome in the context of uremia. Thus, the role of phosphate binders may be more complex than initially anticipated and not limited to the extra calcium load. Even if detailed mechanisms of action for sevelamer are not yet clearly established (except for its lipid‐lowering action), sevelamer may have a number of additional nonphosphate‐lowering actions (including lipid lowering as well as improvement in endothelial function, modulation of inflammation and oxidative stress and binding of uremic toxin absorption). Whether these potentially very interesting pleiotropic effects of sevelamer may be translated into significant clinical benefits remains to be established.
Editorials: Comparison of Proposed Alternative Methods for Rescaling Dialysis Dose: Resting Energy Expenditure, High Metabolic Rate Organ Mass, Liver Size, and Body Surface Area
Authors: Daugirdas John T. , Levin Nathan W. , Kotanko Peter , Depner Thomas A. , Kuhlmann Martin K. , Chertow Glenn M. , Rocco Michael V.
Published: October 2008

A number of denominators for scaling the dose of dialysis have been proposed as alternatives to the urea distribution volume (V). These include resting energy expenditure (REE), mass of high metabolic rate organs (HMRO), visceral mass, and body surface area. Metabolic rate is an unlikely denominator as it varies enormously among humans with different levels of activity and correlates poorly with the glomerular filtration rate. Similarly, scaling based on HMRO may not be optimal, as many organs with high metabolic rates such as spleen, brain, and heart are unlikely to generate unusually large amounts of uremic toxins. Visceral mass, in particular the liver and gut, has potential merit as a denominator for scaling; liver size is related to protein intake and the liver, along with the gut, is known to be responsible for the generation of suspected uremic toxins. Surface area is time‐honored as a scaling method for glomerular filtration rate and scales similarly to liver size. How currently recommended dialysis doses might be affected by these alternative rescaling methods was modeled by applying anthropometric equations to a large group of dialysis patients who participated in the HEMO study. The data suggested that rescaling to REE would not be much different from scaling to V. Scaling to HMRO mass would mandate substantially higher dialysis doses for smaller patients of either gender. Rescaling to liver mass would require substantially more dialysis for women compared with men at all levels of body size. Rescaling to body surface area would require more dialysis for smaller patients of either gender and also more dialysis for women of any size. Of these proposed alternative rescaling measures, body surface area may be the best, because it reflects gender‐based scaling of liver size and thereby the rate of generation of uremic toxins.
Microphthalmia with Linear Skin Defects: A Case Report and Review
Authors: Sharma Vishakha M. , Ruiz de Luzuriaga Arlene M. , Waggoner Darrel , Greenwald Mark , Stein Sarah L.
Published: October 2008

Abstract:  Microphthalmia with linear skin defects syndrome is an X‐linked dominant disorder characterized by microphthalmia and other ocular anomalies as well as linear, jagged skin defects typically involving the scalp, face, neck, and upper trunk. Other associated characteristics include short stature, developmental delay, congenital heart defects, diaphragmatic hernia, agenesis of the corpus callosum, anencephaly, hydrocephalus, and seizures. Microphthalmia with linear skin defects syndrome is now known to be associated with a deletion of the X chromosome at Xp22. This is an area that has been found to include the HCCS gene, which encodes a holocytochrome c‐type synthase believed to be critical in the regulation of apoptosis. We present a patient with classic clinical and genetic findings of MLS syndrome and discuss the primary characteristics and management of this disorder.
Enhanced Response of Childhood Psoriasis to Narrow‐Band UV‐B Phototherapy with Preirradiation Use of Mineral Oil
Authors: Jain Vijay Kumar , Bansal Anu , Aggarwal Kamal , Jain Kapil
Published: October 2008

Abstract:  Studies in adults show that pretreatment with an optimal emollient may improve transmission of ultraviolet‐B. In our study, we evaluated whether the preirradiation use of mineral oil enhanced the efficacy of narrow‐band ultraviolet‐B phototherapy in childhood psoriasis. Twenty children, aged 5 to 14 years with widespread, symmetrical psoriasis involving >20% body surface area were enrolled in a prospective, single‐blind, controlled study. Mineral oil was applied prior to irradiation over one half of the body and the other half was emollient‐free control. Narrow‐band ultraviolet‐B phototherapy was administered to whole body twice a week on nonconsecutive days with initial dose of 50 mJ/cm2 and increment of 10% at each session. Clinical response was evaluated as grades of erythema, scaling and induration, area of involvement and modified psoriasis area severity index score on each side at baseline, 3, 6, 9, and 12 weeks. Two patients dropped out, 18 patients completed the study. Significantly greater improvement (p < 0.05) in scaling, induration, area of involvement, and modified psoriasis area severity index score was seen on the mineral oil pretreated side as early as 3 weeks and was maintained throughout the study. Difference in erythema was noticed later at 6 weeks. The cumulative dose for clearance was significantly lower on the emollient pretreated side. No adverse effects were observed with mineral oil or narrow‐band ultraviolet‐B phototherapy. We conclude that preirradiation use of mineral oil enhances the therapeutic efficacy of narrow‐band ultraviolet‐B phototherapy in children with widespread psoriasis.
Infectious and Inflammatory Skin Diseases in Children with HIV Infection and their Relation with the Immune Status—Evaluation of 127 Patients
Authors: CARVALHO VÂNIA OLIVEIRA , CRUZ CRISTINA RODRIGUES , MARINONI LEIDE PAROLIN , LIMA HERMÊNIO CAVALCANTE
Published: October 2008

Abstract:  Human immunodeficiency virus infection causes changes in the immune system and disease evolution can be partially measured by levels of T CD4+ lymphocytes. Knowledge of the chronology of skin disease in relationship to the immune status of the patient may help understand the pathogenesis of AIDS. One hundred twenty‐seven children were prospectively evaluated for skin diseases and their relationship to immune status. Immunodeficiency in human immunodeficiency virus‐infected children was correlated with infectious dermatoses whereas normal CD4+ T lymphocyte levels was correlated with diseases mediated by hypersensitivity mechanisms.
Two Cases of Cushing’s Syndrome Due to Overuse of Topical Steroid in the Diaper Area1
Authors: Semiz Serap , Balcı Yasemin Işık , Ergin Şeniz , Candemir Maşallah , Polat Aziz
Published: October 2008

Abstract:  Topical use of corticosteroids may cause immunosuppression and iatrogenic Cushing’s syndrome via hypothalamic‐pituitary‐adrenal axis. We report two cases with iatrogenic Cushing’s syndrome with different clinical outcomes due to abuse of same potent topical steroid clobetasol propionate. One of them died because of fatal disseminated cytomegalovirus infection. The other patient recovered completely. Physicians and parents should be informed about the adverse effects of such potent topical corticosteroids and physicians should prescribe less potent agents, especially during infancy.
Congenital Mucinous Eccrine Nevus in a 5‐Month‐Old Girl with Frequent Intertriginous Dermatitis
Authors: CHEN CHIA‐WEI , TSAI TSEN‐FANG , CHEN YU‐FU , HUNG CHIH‐MING
Published: October 2008

Abstract:  We present a 5‐month‐old girl with one localized plaque in a bandlike distribution on the left wrist since birth. Localized hyperhidrosis was also noted. Histopathologic examination of the lesion showed typical findings of mucinous eccrine nevus. Our report may serve to alert dermatologists to consider this entity in congenital lesions.
Trichotillomania in Early Childhood––a Report of two Cases with a Peculiar Habit
Authors: MADSEN J.T. , BYGUM A.
Published: October 2008

Abstract:  Trichotillomania in early childhood is considered a benign habit disorder in contrary to older children and adults where trichotillomania is associated with greater psychopathology. We present two cases of trichotillomania in young children, both using a pacifier to pull out their hair.
Easy Griseofulvin Dosing
Authors: SILVERBERG NANETTE B.
Published: October 2008

Letters to the Editor are welcomed for publication (subject to editing). Letters must be signed by all authors, typewritten double spaced, and must not exceed two pages of text including references. Two copies of all letters should be submitted along with one copy on disk. Letters should not duplicate material submitted or published in other journals. Prepublication proofs will not be provided.
Mycosis Fungoides with Focal CD 30 Transformation in an Adolescent
Authors: ROMERO MONICA , HANEY MICHAELA , DESANTIS EMILY , ZLOTOFF BARRETT
Published: October 2008

Abstract:  Mycosis fungoides is rare in children and adolescents. Large cell transformation in mycosis fungoides is typically seen in adult patients with advanced disease. We describe a 16‐year‐old girl with patch/plaque stage mycosis fungoides who developed a nodule within one of the plaques, which on histopathology showed large cell transformation, with positive labeling with the CD30 immunostain. To the best of our knowledge, this is the second reported case of mycosis fungoides with CD30+ large cell transformation in a child.
A Report of GJB2 (N14K) Connexin 26 Mutation in Two Patients—A New Subtype of KID Syndrome?
Authors: Lazic Tamara , Horii Kimberly A. , Richard Gabriele , Wasserman Daniel I. , Antaya Richard J.
Published: October 2008

Abstract:  Keratitis–ichthyosis–deafness syndrome is a rare congenital ectodermal disorder, characterized by presence of skin lesions, neurosensory hearing loss, and vascularizing keratitis. Several autosomal dominant mutations in the Connexin 26 gene (GJB2) have been discovered as a cause of this syndrome. We report two patients who presented with a combination of clinical features of keratitis–ichthyosis–deafness syndrome (e.g., congenital bilateral neurosensory hearing loss and erythrokeratoderma), however, lacking other characteristics typical of this condition. In addition, they both demonstrated striking mucocutaneous findings (e.g., chronic lip fissuring, gingival hyperemia), resulting in diagnostic difficulties. In both patients, a GJB2 mutation (N14K) was identified, which shares the same gene with classic Keratitis–ichthyosis–deafness syndrome but has never been described in patients with this condition. We propose that the findings observed in our patients are a distinct subtype of Keratitis–ichthyosis–deafness syndrome, thus expanding the spectrum of connexin‐associated keratodermias.
Clinically Relevant Patch Test Reactions in Children—A United States Based Study
Authors: Jacob Sharon E. , Brod Bruce , Crawford Glen H.
Published: October 2008

Abstract:  Allergic contact dermatitis in the pediatric population is more common than previously recognized, with recent prevalence estimates of positive patch test reactions in the range of 14–70% of children patch tested. The aim of this study was to confirm the prevalence of clinically relevant allergic contact dermatitis in children at two referral centers and determine the most common contact allergens. We performed a retrospective case series analysis of 65 symptomatic children (35 girls and 30 boys) aged 1–18 years old who were patch tested over a 5‐year period for recalcitrant dermatitis. Positive patch test reactions were noted in 54 of the 65 children (prevalence rate of 83%) to 80 different allergens. Fifty children (77%) had positive reactions which were determined to be of “definite” or “probable” current clinical relevance. We conclude that the diagnosis of allergic contact dermatitis to specific relevant allergens is common in children referred for patch testing and that contact allergy should be considered in all children with recalcitrant dermatitis. With this article, we review the literature and present a US based study regarding the clinical relevance of positive patch test reactions in children.