Antibody and Keratinocyte responses to Malassezia pachydermatis in dogs

Malassezia pachydermatis, a lipophilic, unipolar-budding yeast is a commensal on canine skin and it can be isolated from the skin and ear canals of healthy dogs. A dermatitis associated with elevated cutaneous populations of M. pachydermatis has been increasingly recognised in the last two decades and one of the most common underlying causes of Malassezia overgrowth in dogs is atopic dermatitis. The aim of these studies was to investigate two aspects of the host's protective responses against the organism - activation of a humoral immune response and thickening of the skin by epidermal hyperplasia.The interaction between M. pachydermatis and the host's immune system has not been widely studied either in normal or atopic dogs. To investigate antibody responses to M. pachydermatis, Western blotting techniques were used to detect Malassezia-specific IgG and IgE binding proteins from M. pachydermatis in atopic dogs with or without Malassezia dermatitis and normal dogs. By comparing the binding activity on the immunoblots, atopic dogs with Malassezia dermatitis showed much greater IgG and IgE responses to M. pachydermatis than normal dogs. The IgG in sera from the majority of the atopic dogs with Malassezia dermatitis recognised a 25 kDa protein, which was only seen in less than 25 % of the atopic dogs without Malassezia dermatitis and none of the normal dogs. Proteins of 45, 52, 56, and 63 kDa were recognised by IgE in more than 50 % of the atopic dogs with Malassezia dermatitis, but only recognised by a minority of normal dog sera, and therefore represented major allergens. These results suggest that Malassezia dermatitis in atopic dogs is associated with an IgG and IgE response to the organism, with the above proteins being most relevant in the immunological reaction.In addition to mounting immunological responses, the skin also undergoes biological changes in response to environmental insults. Epidermal hyperplasia is one of the major characteristics of skin biopsies from dogs with Malassezia dermatitis. The mechanisms by which M. pachydermatis induces epidermal lesions are not fully understood. To investigate the role of M. pachydermatis in the pathogenesis of epidermal hyperplasia associated with Malassezia dermatitis, a colourimetric cell proliferation assay was developed to evaluate the effect of extracts and culture supernatants from M. pachydermatis on proliferation of canine keratinocytes in vitro. Malassezia extracts, either with or without protease inhibitors, and culture supernatants from the yeast, did not affect the proliferation of normal canine keratinocytes in vitro. To further investigate the response of a direct interaction between canine keratinocytes and live Malassezia organisms, an in vitro co-culture system was developed. The proliferative response of the keratinocytes was assessed using direct manual counting and immunohistochemistry techniques. Malassezia organisms did not cause keratinocyte proliferation, but they induced keratinocyte detachment from the substratum and cell death. These results suggest that the epidermal hyperplasia seen in dogs with Malassezia dermatitis is unlikely to be caused by a direct effect of the organism on the keratinocyte cell cycle, but is likely to involve other mechanisms.These studies provide further information regarding the host response to M. pachydermatis, and suggest possible mechanisms by which overgrowth of Malassezia organisms causes pathological changes in the skin of dogs

Reconstruction for Mandibular Implant Failure

Mandibular defects may result from tumor ablations, trauma, or radiation necrosis. Significant segmental mandibular loss or hemimandibular loss may sometimes be replaced with mandibular implants by ENT surgeons/oral surgeons/head and neck surgeons. However, this may bring about mandibular implant failure in long-term follow-up. Mandibular implant failures usually manifest as: soft tissue atrophy, mandibular implant extrusion, infection, facial nerve involvement, facial asymmetry, derangement of occlusion and mastication, orocutaneous fistula, etc. Over 30 years, the authors have treated 102 patients with mandibular implant failure. Reconstruction may involve removal of the mandibular implant and immediate replacement of the mandibular defect with a piece of vascularized bone flap, not only to compensate for bone loss but also to replace neighboring soft tissue and possible skin defects. Frequently used flaps have been vascularized iliac bone (89/102) or vascularized fibula grafts (13/102). During follow-up, iliac bone flap reconstruction has yielded more favorable results due to its ample bone bulk and adequate soft tissue coverage. Fibula flaps with osteotomies have been associated with an increasing incidence of malunion/nonunion and subsequent easy deformation

A Wafer-Bonded, Floating Element Shear-Stress Sensor Using a Geometric Moire Optical Transduction Technique

This paper presents a geometric Moir optical-based floating-element shear stress sensor for wind tunnel turbulence measurements. The sensor was fabricated using an aligned wafer-bond/thin-back process producing optical gratings on the backside of a floating element and on the top surface of the support wafer. Measured results indicate a static sensitivity of 0.26 microns/Pa, a resonant frequency of 1.7 kHz, and a noise floor of 6.2 mPa/(square root)Hz

GenEpi: gene-based epistasis discovery using machine learning.

BackgroundGenome-wide association studies (GWAS) provide a powerful means to identify associations between genetic variants and phenotypes. However, GWAS techniques for detecting epistasis, the interactions between genetic variants associated with phenotypes, are still limited. We believe that developing an efficient and effective GWAS method to detect epistasis will be a key for discovering sophisticated pathogenesis, which is especially important for complex diseases such as Alzheimer's disease (AD).ResultsIn this regard, this study presents GenEpi, a computational package to uncover epistasis associated with phenotypes by the proposed machine learning approach. GenEpi identifies both within-gene and cross-gene epistasis through a two-stage modeling workflow. In both stages, GenEpi adopts two-element combinatorial encoding when producing features and constructs the prediction models by L1-regularized regression with stability selection. The simulated data showed that GenEpi outperforms other widely-used methods on detecting the ground-truth epistasis. As real data is concerned, this study uses AD as an example to reveal the capability of GenEpi in finding disease-related variants and variant interactions that show both biological meanings and predictive power.ConclusionsThe results on simulation data and AD demonstrated that GenEpi has the ability to detect the epistasis associated with phenotypes effectively and efficiently. The released package can be generalized to largely facilitate the studies of many complex diseases in the near future

Reduction of Ischemic and Oxidative Damage to the Hypothalamus by Hyperbaric Oxygen in Heatstroke Mice

The aims of the present paper were to ascertain whether the heat-induced ischemia and oxidative damage to the hypothalamus and lethality in mice could be ameliorated by hyperbaric oxygen therapy. When normobaric air-treated mice underwent heat treatment, the fractional survival and core temperature at 4 hours after heat stress were found to be 0 of 12 and 34°C ± 0.3°C, respectively. In hyperbaric oxygen-treated mice, when exposed to the same treatment, both fractional survival and core temperature values were significantly increased to new values of 12/12 and 37.3°C ± 0.3°C, respectively. Compared to normobaric air-treated heatstroke mice, hyperbaric oxygen-treated mice displayed lower hypothalamic values of cellular ischemia and damage markers, prooxidant enzymes, proinflammatory cytokines, inducible nitric oxide synthase-dependent nitric oxide, and neuronal damage score. The data indicate that hyperbaric oxygen may improve outcomes of heatstroke by normalization of hypothalamic and thermoregulatory function in mice

Recombinant VP1, an Akt Inhibitor, Suppresses Progression of Hepatocellular Carcinoma by Inducing Apoptosis and Modulation of CCL2 Production

BACKGROUND: The application of viral elements in tumor therapy is one facet of cancer research. Recombinant capsid protein VP1 (rVP1) of foot-and-mouth disease virus has previously been demonstrated to induce apoptosis in cancer cell lines. Here, we aim to further investigate its apoptotic mechanism and possible anti-metastatic effect in murine models of hepatocellular carcinoma (HCC), one of the most common human cancers worldwide. METHODOLOGY/PRINCIPAL FINDINGS: Treatment with rVP1 inhibited cell proliferation in two murine HCC cell lines, BNL and Hepa1-6, with IC₅₀ values in the range of 0.1-0.2 µM. rVP1 also induced apoptosis in these cells, which was mediated by Akt deactivation and dissociation of Ku70-Bax, and resulted in conformational changes and mitochondrial translocation of Bax, leading to the activation of caspases-9, -3 and -7. Treatment with 0.025 µM rVP1, which did not affect the viability of normal hepatocytes, suppressed cell migration and invasion via attenuating CCL2 production. The production of CCL2 was modulated by Akt-dependent NF-κB activation that was decreased after rVP1 treatment. The in vivo antitumor effects of rVP1 were assessed in both subcutaneous and orthotopic mouse models of HCC in immune-competent BALB/c mice. Intratumoral delivery of rVP1 inhibited subcutaneous tumor growth as a result of increased apoptosis. Intravenous administration of rVP1 in an orthotopic HCC model suppressed tumor growth, inhibited intra-hepatic metastasis, and prolonged survival. Furthermore, a decrease in the serum level of CCL2 was observed in rVP1-treated mice. CONCLUSIONS/SIGNIFICANCE: The data presented herein suggest that, via inhibiting Akt phosphorylation, rVP1 suppresses the growth, migration, and invasion of murine HCC cells by inducing apoptosis and attenuating CCL2 production both in vitro and in vivo. Recombinant protein VP1 thus has the potential to be developed as a new therapeutic agent for HCC

The nucleolar protein NIFK promotes cancer progression via CK1α/β-catenin in metastasis and Ki-67-dependent cell proliferation.

Nucleolar protein interacting with the FHA domain of pKi-67 (NIFK) is a Ki-67-interacting protein. However, its precise function in cancer remains largely uninvestigated. Here we show the clinical significance and metastatic mechanism of NIFK in lung cancer. NIFK expression is clinically associated with poor prognosis and metastasis. Furthermore, NIFK enhances Ki-67-dependent proliferation, and promotes migration, invasion in vitro and metastasis in vivo via downregulation of casein kinase 1α (CK1α), a suppressor of pro-metastatic TCF4/β-catenin signaling. Inversely, CK1α is upregulated upon NIFK knockdown. The silencing of CK1α expression in NIFK-silenced cells restores TCF4/β-catenin transcriptional activity, cell migration, and metastasis. Furthermore, RUNX1 is identified as a transcription factor of CSNK1A1 (CK1α) that is negatively regulated by NIFK. Our results demonstrate the prognostic value of NIFK, and suggest that NIFK is required for lung cancer progression via the RUNX1-dependent CK1α repression, which activates TCF4/β-catenin signaling in metastasis and the Ki-67-dependent regulation in cell proliferation