That dog won't fit: body size awareness in dogs.

With very few exceptions, no coherent model of representing the self exists for nonhuman species. According to our hypothesis, understanding of the Self as an object' can also be found in a wide range of animals including the dog, a fast-moving terrestrial predator/scavenger, with highly developed senses and complex cognitive capacity. We tested companion dogs in three experiments in which they faced three different variations of the same physical challenge: passing through an opening in a wall. We predicted that if dogs are capable of representing their own body size, they will react differently when faced with adequate or too small openings. We found that dogs started to move towards and approached the too small openings with significantly longer latencies than the suitable ones; and upon reaching it, they did not try to get through the too small openings. In another experiment, the medium-size (still large enough) opening was approached with latencies that fell between the latencies measured in the cases of the very large or the too small openings. Having discussed the potential underlying mechanisms, we concluded that our results convincingly assume that dogs can represent their own body size in novel contexts.

Sebum lipids influence macrophage polarization and activation.

BACKGROUND: As lipids are known to regulate macrophage functions, it is reasonable to suppose that a sebocyte-macrophage axis mediated by sebum lipids may exist. OBJECTIVES: To investigate if sebocytes could contribute to the differentiation, polarization and function of macrophages with their secreted lipids. METHODS: Oil Red O lipid staining and Raman spectroscopy were used to assess the dermal lipid content and penetration. Immunohistochemistry was used to analyse the macrophage subsets. Human peripheral blood monocytes were differentiated in the presence of either supernatant from human SZ95 sebocytes or major sebum lipid components and activated with Propionibacterium acnes. Macrophage surface markers and their capacity to uptake fluorescein isothiocyanate-conjugated P. acnes were detected by fluorescence-activated cell sorting measurements. Cytokine protein levels were evaluated by enzyme-linked immunosorbent assay and Western blot analysis. RESULTS: Sebaceous gland-rich skin had an increased dermal lipid content vs. sebaceous gland-poor skin to which all the tested sebum component lipids could contribute by penetrating the dermoepidermal barrier. Of the lipids, oleic acid and linoleic acid promoted monocyte differentiation into alternatively activated macrophages. Moreover, linoleic acid also had an anti-inflammatory effect in P. acnes-activated macrophages, inhibiting the secretion of interleukin (IL)-1ß, IL-6 and tumour necrosis factor (TNF)-α. Squalene, palmitic acid, stearic acid and oleic acid augmented the secretion of IL-1ß, even in the absence of P. acnes, whereas oleic acid had a selective effect of inducing IL-1ß but downregulating IL-6 and TNF-α secretion. CONCLUSIONS: Our results suggest a role for sebaceous glands in modulating innate immune responses via their secreted lipids that are of possible pathological and therapeutic relevance.

Vitiligo: characterization of melanocytes in repigmented skin after punch grafting.

BACKGROUND: Punch grafting is a surgical technique mainly applied in therapy-resistant, stable and circumscribed vitiligo. OBJECTIVE: (i) To characterize in detail the features of the repigmented skin among punch grafts; and (ii) to correlate the ex vivo results with clinical data and punch grafting outcome. METHODS: We evaluated by immunohistochemistry and image analysis the expression of a panel of specific melanocyte markers including HMB45, MITF, c-kit, MART-1 and TRP1, the proliferation marker Ki67 and the cell-cell adhesion molecule E-cadherin in tissue samples collected from nine patients after punch grafting. RESULTS: Cells positive for MITF, c-kit, MART-1 and TRP1 were detected in the repigmented skin of all biopsies, whereas no reactivity was observed for HMB45. Melanocytes were identified along the entire length of the sections, and their mature state was assessed by the immuno-reactivity for the differentiation marker MART-1, the absence of cells positively stained for Ki67 and by the co-expression of c-kit and TRP1, a marker of a differentiated and pigmented state. Clinically, smaller punch grafts aimed at repigmenting lesional areas on the face gave the faster clinical results with no side-effects. Patients subjected to bigger punch grafts on the knee exhibited a longer repigmentation time and presented cobble stoning. CONCLUSION: Our results suggest that the repigmentation observed in the areas between the grafts is due to the activation of the melanocytes located in the donor sites. These cells start to horizontally migrate towards the lesional skin thanks to successively the enlargement of intercellular spaces in relation to a decrease of E-cadherin reactivity and the up-modulation of pro-melanogenic mediators. Production and transfer of melanin in the surrounding keratinocytes and their persistence were assessed by the reactivity for MITF, c-kit, MART-1 and TRP1 but not for the pre-melanosome marker (HMB45).

Serum C-reactive protein and white blood cell level as markers of successful percutaneous drainage of acute sterile peripancreatic fluid collection.

BACKGROUND: Percutaneous drainage is not a widely used therapeutic method recently for evacuating peripancreatic sterile fluid collections in patients with severe acute pancreatitis.However, many clinical studies have proved its positive effects. AIM: We tested the changes in serum laboratory parameters:C-reactive protein (CRP), complement factor 3-4 (C 3-4),tumor necrosis factor a (TNF-a), amylase, lipase and white blood cell (WBC) count in patients treated by percutaneous drainage. PATIENTS AND METHODS: 10 patients with severe acute pancreatitis with peripancreatic fluid collection were monitored.Laboratory parameters and the amount of drained fluid were measured on the 1st, 5th and 10th day. Statistical analysis was performed by using Statistica for Windows (Version 7.0)software. P values less than 0.05 were considered statistically significant. RESULTS: We found significant positive correlation between the CRP and WBC serum level and volumes of the drained fluid. We used these parameters as markers of successful percutaneous drainage in case of patients with severe acute pancreatitis complicated with sterile peripancreatic fluid.There was no significant change in the levels of C 3-4,tumor necrosis factor-Î+-, amylase and lipase. CONCLUSIONS: Monitoring of serum CRP and WBC levels maybe recommended for follow up after percutaneous drainage of peripancreatic fluid. ABBREVIATIONS: CRP: C-reactive Protein TNFÎ+-: Tumour Necrosis Factor a, C3-4: Complement 3-4 WBC: White Blood Cell CT: Computed Tomography.

Inflammasome activation and vitiligo/nonsegmental vitiligo progression.

BACKGROUND: Polymorphisms of NLR (nucleotide-binding domain and leucine rich repeat containing) family, pyrin domain containing protein 1 (NLRP1) have been found in patients with vitiligo/nonsegmental vitiligo (NSV), and increased NLRP1 expression has been detected in the leading edge of lesional skin biopsies. OBJECTIVES: To evaluate the presence and intensity of NLRP1 immunostaining in lesional and perilesional skin of patients with vitiligo/NSV and to search for possible correlations between NLRP1 and interleukin (IL)-1ß expression, lymphocytic infiltrates and disease activity. METHODS: Of 14 consecutive vitiligo/NSV patients, eight had active disease [Vitiligo European Task Force (VETF) spreading score +1 to +5], one patient had stable disease and five patients had regressive disease (VETF spreading score -1 to -3). We performed immunostaining for NLRP1, B and T lymphocytes, IL-1ß and kallikrein 7 on lesional and perilesional vitiligo skin. RESULTS: NLRP1 and IL-1ß immunostaining in perilesional vitiligo/NSV skin was significantly associated with progressive disease (P = 0·009 and 0·04, respectively) and performed better than the simple detection of lymphocytic infiltrates. CONCLUSIONS: Our findings suggest that markers of the NLRP1 inflammasome could be a useful test for assessing disease activity in addition to the detection of inflammatory infiltrates in the progressing margins of vitiligo/NSV lesions.

Leptin promotes a proinflammatory lipid profile and induces inflammatory pathways in human SZ95 sebocytes.

BACKGROUND: Leptin, the adipocyte-secreted hormone that regulates weight, is known to link lipid metabolism with inflammation in various cell types. However, its role in human sebocytes has not yet been investigated. OBJECTIVES: The purpose of this study was to investigate the effects of leptin in human sebaceous gland biology. METHODS: Expression of the long form of the leptin receptor (Ob-Rb) was detected by real-time quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and immunochemistry. Lipid analysis was by high-performance thin-layer chromatography, gas chromatography-mass spectrometry and time-of-flight mass spectrometer mass detection. Lipid bodies were visualized by BODIPY staining using fluorescent microscopy and measured by flow cytometry. Interleukin (IL)-6 and IL-8 mRNA levels were assessed by real-time qRT-PCR and their release was evaluated by enzyme-linked immunosorbent assay. Cyclooxygenase (COX)-2 and 5-lipooxygenase (LOX) protein expression and phosphorylation of p65 and signal transducer and activator of transcription (STAT)-3 were determined by Western blot analysis. RESULTS: Expression of Ob-Rb was detected in human sebaceous glands and in cultured human SZ95 sebocytes. The treatment of SZ95 sebocytes with leptin led to enlarged intracellular lipid bodies, increased ratios of unsaturated/saturated fatty acids and decreased vitamin E levels. Further supporting a proinflammatory role, leptin induced COX-2 and 5-LOX expression in SZ95 sebocytes and augmented the production of IL-6 and IL-8 cytokines. On leptin treatment, the STAT-3 and nuclear factor-κB pathways were activated, indicating that these known leptin signalling pathways are active in human sebocytes. CONCLUSIONS: Our findings suggest that leptin signalling may be involved in the proinflammatory regulation of sebaceous lipid metabolism and the induction of inflammatory enzymes and cytokines.

Intrinsically disordered proteins undergo and assist folding transitions in the proteome.

The common notion in the protein world holds that proteins are synthesized as a linear polypeptide chain, followed by folding into a unique, functional 3D-structure. As outlined in many articles of this volume, this is in fact the case for a great proportion of the proteome. Many proteins and protein domains, however, are intrinsically disordered (IDPs), i.e., they cannot fold on their own, but often undergo a folding transition in the presence of a binding partner. This binding-induced folding process shows strong conceptual parallels with the folding of globular proteins, in a sense that it can proceed via two routes, either induction of the folded conformation from an initial random state or selection of a pre-formed state already present in the ensemble. In addition, we show that IDPs not only undergo folding themselves, they also assist the folding process of other proteins as chaperones, and even contribute to the quality control processes of the cell, in which irreparably misfolded proteins are recognized and tagged for proteasomal degradation. These various mechanisms suggest that structural disorder, in a biological context, is linked with protein folding in several ways, in which both the IDP and its partner may undergo reciprocal structural transitions.

Angiokeratoma: decision-making aid for the diagnosis of Fabry disease.

Isolated angiokeratomas are common benign cutaneous lesions, generally deemed unworthy of further investigation. In contrast, diffuse angiokeratomas should alert the physician to a possible diagnosis of Fabry disease, a rare X-linked lysosomal storage disorder, characterized by α-galactosidase deficiency. Glycosphingolipids accumulate in cells throughout the body resulting in progressive multi-organ failure. Difficulties are encountered when trying to interpret the significance of angiokeratomas because they may also occur in other lysosomal storage disorders and rarely in an isolated manner in Fabry disease. We present an algorithm for the classification of angiokeratomas which might prove useful for the diagnosis and management of Fabry disease. Assessment of the clinical features and location of the lesions, personal and family history, skin biopsy, dermoscopy and electron microscopy imaging are sequential steps in the diagnostic process. Assessing the deficiency of α-galactosidase enzyme activity is essential to confirm the diagnosis in males, while mutation analysis is always needed in females. Potentially this algorithm can change the current approach to patients when Fabry disease is suspected, thus improving the diagnostic strategy and management of this disorder. It remains to be decided whether the use of an algorithm might reduce the number of genetic consultations. As evidence has shown the efficacy of enzyme replacement therapy in halting progression of the disease before the onset of irreversible organ damage, it is advisable to aim at an early diagnosis in order to achieve timely initiation of effective treatment with benefits for patients and appropriate use of medical resources.

[Mechanisms underlying post-inflammatory hyperpigmentation: lessons from solar lentigo]. / Mécanismes de l'hyperpigmentation post-inflammatoire: ce que le lentigo actinique nous a appris.

Hyperpigmentation of the skin is a common dermatologic condition in all skin types but most prominent in brown-skinned population. In skin of color any inflammation or injury can be accompanied by alterations in pigmentation (hyper/hypo-pigmentation). Postinflammatory hyperpigmentation (PIH) can be observed in many skin conditions including acne, eczema, and contact dermatitis. In the control of skin pigmentation, parallel to the cross-talk between keratinocytes and melanocytes, increasing evidence has underlined the crucial role exerted by the interactions between mesenchymal and epithelial cells through the release of fibroblast-derived growth factors. Among these factors, the keratinocyte growth factor (KGF), alone or in combination with interleukin-1α, induces melanin deposition in vitro and hyperpigmented lesions in vivo. Furthermore, a moderate increase of KGF and a high induction of its receptor have been shown in solar lentigo lesions, suggesting the involvement of this growth factor in the onset of the hyperpigmented spots. Several studies highlight the possible contribution of the fibroblast-derived melanogenic growth factors to the hyperpigmentated lesions, in the context of the mesenchymal - epithelial interactions modulating melanocyte functions.

Mechanisms underlying post-inflammatory hyperpigmentation: lessons from solar lentigo.

Hyperpigmentation of the skin is a common dermatologic condition in all skin types but most prominent in brown-skinned population. In skin of color any inflammation or injury can be accompanied by alterations in pigmentation (hyper/hypo-pigmentation). Postinflammatory hyperpigmentation (PIH) can be observed in many skin conditions including acne, eczema, and contact dermatitis. In the control of skin pigmentation, parallel to the cross-talk between keratinocytes and melanocytes, increasing evidence has underlined the crucial role exerted by the interactions between mesenchymal and epithelial cells through the release of fibroblast-derived growth factors. Among these factors, the keratinocyte growth factor (KGF), alone or in combination with interleukin-1α, induces melanin deposition in vitro and hyperpigmented lesions in vivo. Furthermore, a moderate increase of KGF and a high induction of its receptor have been shown in solar lentigo lesions, suggesting the involvement of this growth factor in the onset of the hyperpigmented spots. Several studies highlight the possible contribution of the fibroblast-derived melanogenic growth factors to the hyperpigmentated lesions, in the context of the mesenchymal - epithelial interactions modulating melanocyte functions.

Acyl-coenzyme A: cholesterol acyltransferase modulates the generation of the amyloid beta-peptide.

The pathogenic event common to all forms of Alzheimer's disease is the abnormal accumulation of the amyloid beta-peptide (Abeta). Here we provide strong evidence that intracellular cholesterol compartmentation modulates the generation of Abeta. Using genetic, biochemical and metabolic approaches, we found that cholesteryl-ester levels are directly correlated with Abeta production. Acyl-coenzyme A:cholesterol acyltransferase (ACAT), the enzyme that catalyses the formation of cholesteryl esters, modulates the generation of Abeta through the tight control of the equilibrium between free cholesterol and cholesteryl esters. We also show that pharmacological inhibitors of ACAT, developed for the treatment of atherosclerosis, are potent modulators of Abeta generation, indicating their potential for use in the treatment of Alzheimer's disease.

Alzheimer-associated presenilins 1 and 2: neuronal expression in brain and localization to intracellular membranes in mammalian cells.

Mutations in two recently identified genes appear to cause the majority of early-onset familial Alzheimer's disease (FAD). These two novel genes, presenilin 1 (PS1) and presenilin 2 (PS2) are members of an evolutionarily conserved gene family. The normal biological role(s) of the presenilins and the mechanism(s) by which the FAD-associated mutations exert their effect remain unknown. Employing in situ hybridization, we demonstrate that the expression patterns of PS1 and PS2 in the brain are extremely similar to each other and that messages for both are primarily detectable in neuronal populations. Immunochemical analyses indicate that PS1 and PS2 are similar in size and localized to similar intracellular compartments (endoplasmic reticulum and Golgi complex). FAD-associated mutations in PS1 and PS2 do not significantly modify either their migration patterns on SDS-polyacrylamide gel electrophoresis or their overall subcellular localization, although subtle differences in perinuclear staining were noted for mutant PS1.

Sample-size dependence of validation parameters in linear regression models and in QSAR.

The dependence of statistical validation parameters was investigated on the size of the sample taken in fit of multivariate linear curves. We observed that R2 and related internal parameters were misleading as they overestimated the goodness-of-fit of models at small sample size. Cross-validation metrics showed correct trends. It was possible to scale the leave-one-out and the leave-many-out results close to identical by correcting the degrees of freedom of the models. y and x-randomized validation parameters were calculated and the methods provided close to identical results. We suggest to use the simplest methods in both cases. The external parameters followed correct trends with respect to the sample size, but their sensitivity differed. We plotted the Roy-Ojha metrics in 2D and we coloured them with respect to other external parameters to provide an easy classification of models. The rank correlations were calculated between the performance parameters. Up to a sample size, goodness-of-fit and robustness were distinguishable, but above a certain sample size, the parameters were redundant. The external-internal pairs were weakly correlated. Our data show that all the three aspects of validation are necessary at small sample sizes, but the internal check of robustness is not informative above a given sample size.

Mitochondrial protective effects of PARP-inhibition in hypertension-induced myocardial remodeling and in stressed cardiomyocytes.

AIMS: During oxidative stress mitochondria become the main source of endogenous reactive oxygen species (ROS) production. In the present study, we aimed to clarify the effects of pharmacological PARP-1 inhibition on mitochondrial function and quality control processes. MAIN METHODS: L-2286, a quinazoline-derivative PARP inhibitor, protects against cardiovascular remodeling and heart failure by favorable modulation of signaling routes. We examined the effects of PARP-1 inhibition on mitochondrial quality control processes and function in vivo and in vitro. Spontaneously hypertensive rats (SHRs) were treated with L-2286 or placebo. In the in vitro model, 150 µM H2O2 stress was applied on neonatal rat cardiomyocytes (NRCM). KEY FINDINGS: PARP-inhibition prevented the development of left ventricular hypertrophy in SHRs. The interfibrillar mitochondrial network were less fragmented, the average mitochondrial size was bigger and showed higher cristae density compared to untreated SHRs. Dynamin related protein 1 (Drp1) translocation and therefore the fission of mitochondria was inhibited by L-2286 treatment. Moreover, L-2286 treatment increased the amount of fusion proteins (Opa1, Mfn2), thus preserving structural stability. PARP-inhibition also preserved the mitochondrial genome integrity. In addition, the mitochondrial biogenesis was also enhanced due to L-2286 treatment, leading to an overall increase in the ATP production and improvement in survival of stressed cells. SIGNIFICANCE: Our results suggest that the modulation of mitochondrial dynamics and biogenesis can be a promising therapeutical target in hypertension-induced myocardial remodeling and heart failure.

Role of fibroblast-derived growth factors in regulating hyperpigmentation of solar lentigo.

BACKGROUND: Cutaneous pigmentation is regulated by a complex melanogenic network in which both keratinocytes and fibroblasts synthesize growth factors and cytokines. Solar lentigo (SL) is characterized by hyperpigmented lesions occurring on photodamaged skin areas. Despite the association of SL to ultraviolet (UV) exposure, the mechanisms underlying the development of these spots are not completely defined. OBJECTIVES: To analyse the involvement of the fibroblast-derived growth factors, hepatocyte growth factor (HGF), keratinocyte growth factor (KGF) and stem cell factor (SCF) in SL hyperpigmentation; to evaluate whether the photoageing process occurring in fibroblasts could be responsible for the altered expression of these cytokines; and to investigate a new possible role of KGF in regulating pigmentation through the specific induction of melanogenic cytokines by keratinocytes. METHODS: We performed immunohistochemical analysis of HGF, KGF and SCF on SL biopsies. We analysed the mRNA expression of these cytokines using an in vitro model of photoageing induced on fibroblasts. Finally, we evaluated the effects of KGF on the expression of melanogenic cytokines at the mRNA and protein levels on keratinocytes. RESULTS: We found positive staining for HGF, KGF and SCF in the upper dermis of SL lesions and a significant induction of the three cytokines in photoaged fibroblasts. We also demonstrated the contribution of KGF to pigmentation, showing its ability specifically to modulate the expression of SCF in keratinocytes. CONCLUSIONS: Fibroblasts may be persistently activated by UV exposure to release melanogenic growth factors; this inducible cytokine network acts both directly and indirectly through keratinocytes and may contribute to the hyperpigmentation of SL.

Combined dual energy and iterative metal artefact reduction for PET/CT in head and neck cancer.

Metal artefacts in PET/CT images hamper diagnostic accuracy in head and neck cancer (HNC). The aim of this study is to characterise the clinical effects of metal artefacts on PET/CT in HNC and to inform decision-making concerning implementation of MAR techniques. We study a combined dual energy CT and inpainting-based metal artefact reduction (DECT-I-MAR) technique for PET/CT in three settings: (A) A dental phantom with a removable amalgam-filled tooth to evaluate the PET error in comparison to a known reference. (B) PET-positive patients with metallic implants to demonstrate the relationship between CT metal artefacts and PET error. (C) Metabolic tumour volumes delineated in PET-positive patients with metal implants to evaluate the clinical impact. In (A) DECT-I-MAR reduced the PET error significantly. In (B) we demonstrate an increasing PET error with increasing CT artefact severity in patients. In (C) it is shown that the presence of artefacts in the same axial slices as the tumour significantly decreases biomarker stability and increase delineation variability. This work shows the practical feasibility of DECT-I-MAR-based PET/CT imaging, and indicates a positive clinical impact of using the technique routinely for HNC patients. The impact of CT artefacts on PET is considerable, especially in workflows where quantitative PET biomarkers and tumour volumes are used. In such cases, and for patients with tumours in proximity of metals, we recommend that a MAR technique for PET/CT is employed.

Alternative cleavage of Alzheimer-associated presenilins during apoptosis by a caspase-3 family protease.

Most cases of early-onset familial Alzheimer's disease (FAD) are caused by mutations in the genes encoding the presenilin 1 (PS1) and PS2 proteins, both of which undergo regulated endoproteolytic processing. During apoptosis, PS1 and PS2 were shown to be cleaved at sites distal to their normal cleavage sites by a caspase-3 family protease. In cells expressing PS2 containing the asparagine-141 FAD mutant, the ratio of alternative to normal PS2 cleavage fragments was increased relative to wild-type PS2-expressing cells, suggesting a potential role for apoptosis-associated cleavage of presenilins in the pathogenesis of Alzheimer's disease.

Amyloid protein precursor messenger RNAs: differential expression in Alzheimer's disease.

In situ hybridization was used to assess total amyloid protein precursor (APP) messenger RNA and the subset of APP mRNA containing the Kunitz protease inhibitor (KPI) insert in 11 Alzheimer's disease (AD) and 7 control brains. In AD, a significant twofold increase was observed in total APP mRNA in nucleus basalis and locus ceruleus neurons but not in hippocampal subicular neurons, neurons of the basis pontis, or occipital cortical neurons. The increase in total APP mRNA in locus ceruleus and nucleus basalis neurons was due exclusively to an increase in APP mRNA lacking the KPI domain. These findings suggest that increased production of APP lacking the KPI domain in nucleus basalis and locus ceruleus neurons may play an important role in the deposition of cerebral amyloid that occurs in AD.