High salt intake down-regulates colonic mineralocorticoid receptors, epithelial sodium channels and 11β-hydroxysteroid dehydrogenase type 2

Besides the kidneys, the gastrointestinal tract is the principal organ responsible for sodium homeostasis. For sodium transport across the cell membranes the epithelial sodium channel (ENaC) is of pivotal relevance. The ENaC is mainly regulated by mineralocorticoid receptor mediated actions. The MR activation by endogenous 11β-hydroxy-glucocorticoids is modulated by the 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2). Here we present evidence for intestinal segment specific 11β-HSD2 expression and hypothesize that a high salt intake and/or uninephrectomy (UNX) affects colonic 11β-HSD2, MR and ENaC expression. The 11β-HSD2 activity was measured by means of 3H-corticosterone conversion into 3H-11-dehydrocorticosterone in Sprague Dawley rats on a normal and high salt diet. The activity increased steadily from the ileum to the distal colon by a factor of about 3, an observation in line with the relevance of the distal colon for sodium handling. High salt intake diminished mRNA and protein of 11β-HSD2 by about 50% (p<0.001) and reduced the expression of the MR (p<0.01). The functionally relevant ENaC-β and ENaC-γ expression, a measure of mineralocorticoid action, diminished by more than 50% by high salt intake (p<0.001). The observed changes were present in rats with and without UNX. Thus, colonic epithelial cells appear to contribute to the protective armamentarium of the mammalian body against salt overload, a mechanism not modulated by UNX.

Uninephrectomy reduces 11β-hydroxysteroid dehydrogenase type 1 and type 2 concomitantly with an increase in blood pressure in rats

Renal allograft donors are at risk of developing hypertension. Here, we hypothesized that this risk is at least in part explained by an enhanced intracellular availability of 11β-hydroxyglucocorticoids due to an increased 11β-hydroxysteroid dehydrogenase type 1 enzyme (11β-HSD1), an intracellular prereceptor activator of biologically inactive 11-ketocorticosteroids in the liver, and/or a diminished 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2), an inactivator of 11β-hydroxyglucocorticoids in the kidney. To test this hypothesis, uninephrectomized (UNX) (n=9) and sham-operated (n=10) adult Sprague-Dawley rats were investigated. Mean arterial blood pressure and heart rate were measured continuously by telemetry for 6 days in week 5 after UNX. The mRNA of 11β-Hsd1 and 11β-Hsd2 in liver and kidney tissues were assessed by RT-PCR and the 11β-HSD activities were directly quantified in their corresponding tissues by determining the ratios of (tetrahydrocorticosterone+5α-tetrahydrocorticosterone)/tetrahydrodehydrocorticosterone ((THB+5α-THB)/THA) and of corticosterone/dehydrocorticosterone (B/A) by gas chromatography-mass spectrometry. The apparent total body activities of 11β-HSD1 and 11β-HSD2 were estimated using the urinary and plasma ratios of (THB+5α-THB)/THA and B/A. Mean arterial blood pressure was increased after UNX when compared with sham operation. Hepatic mRNA content of 11β-Hsd1 and hepatic, plasma, and urinary ratios of (THB+5α-THB)/THA were decreased after UNX, indicating diminished access of glucocorticoids to its receptors. In renal tissue, 11β-Hsd2 mRNA was reduced and B/A ratios measured in kidney, plasma, and urine were increased, indicating reduced 11β-HSD2 activity and enhanced access of glucocorticoids to mineralocorticoid receptors. Both 11β-HSD1 and 11β-HSD2 are downregulated after UNX in rats, a constellation considered to induce hypertension.

Penetration of ASM 981 in canine skin: a comparative study

ASM 981 has been developed for topical treatment of inflammatory skin diseases. It specifically inhibits the production and release of pro-inflammatory cytokines. We measured the skin penetration of ASM 981 in canine skin and compared penetration in living and frozen skin. To make penetration of ASM 981 visible in dog skin, tritium labelled ASM 981 was applied to a living dog and to defrosted skin of the same dog. Using qualitative autoradiography the radioactive molecules were detected in the lumen of the hair follicles until the infundibulum, around the superficial parts of the hair follicles and into a depth of the dermis of 200 to 500 microm. Activity could not be found in deeper parts of the hair follicles, the dermis or in the sebaceous glands. Penetration of ASM 981 is low in canine skin and is only equally spread in the upper third of the dermis 24 hours after application. Penetration in frozen skin takes even longer than in living canine skin but shows the same distribution.

Intradermal injection of heat-killed Mycobacterium vaccae in dogs with atopic dermatitis: a multicentre pilot study

Canine atopic dermatitis (cAD) is a common disease with a multifactorial aetiology associated with impaired immunoregulation. The immunopathogenesis has similarities to that of human atopic dermatitis. Clinical signs of allergic disease in humans and mice are reduced by administration of saprophytic mycobacteria that amplify regulatory cytokines and hence the effect of Mycobacterium vaccae on the clinical severity of cAD was investigated. Sixty-two dogs with cAD, selected according to strict criteria, were treated with a single intradermal injection and evaluated monthly for 3 months in a placebo-controlled double-blind clinical trial. Clinical severity was quantified using standardized scores and by owner assessment of pruritus. A single injection of a heat-killed suspension of M. vaccae was found to be well tolerated and effective in treating mild to moderate cases of cAD demonstrable for 3 months, but was insignificant in more severely affected dogs.

Feline herpes dermatitis treated with interferon omega

This case report describes the diagnosis, demonstration and treatment of feline herpes virus-induced facial dermatitis in a cat. The cat was successfully treated with interferon omega (IFN-omega).

[Cutaneous atypical mycobacteriosis due to Mycobacterium massiliense in a cat]

Fast growing mycobacteria are saprophytic bacteria that prevail in water and soil. They are opportunistic pathogens and may cause various infections if gaining entry into the body through a trauma. We herein describe the clinical presentation, pathology and diagnosis of the first case of cutaneous atypical mycobacteriosis due to Mycobacterium massiliense in a cat.

Experimental infection of the pig with Mycobacterium ulcerans: a novel model for studying the pathogenesis of Buruli ulcer disease.

BACKGROUND Buruli ulcer (BU) is a slowly progressing, necrotising disease of the skin caused by infection with Mycobacterium ulcerans. Non-ulcerative manifestations are nodules, plaques and oedema, which may progress to ulceration of large parts of the skin. Histopathologically, BU is characterized by coagulative necrosis, fat cell ghosts, epidermal hyperplasia, clusters of extracellular acid fast bacilli (AFB) in the subcutaneous tissue and lack of major inflammatory infiltration. The mode of transmission of BU is not clear and there is only limited information on the early pathogenesis of the disease available. METHODOLOGY/PRINCIPAL FINDINGS For evaluating the potential of the pig as experimental infection model for BU, we infected pigs subcutaneously with different doses of M. ulcerans. The infected skin sites were excised 2.5 or 6.5 weeks after infection and processed for histopathological analysis. With doses of 2 × 10(7) and 2 × 10(6) colony forming units (CFU) we observed the development of nodular lesions that subsequently progressed to ulcerative or plaque-like lesions. At lower inoculation doses signs of infection found after 2.5 weeks had spontaneously resolved at 6.5 weeks. The observed macroscopic and histopathological changes closely resembled those found in M. ulcerans disease in humans. CONCLUSION/SIGNIFICANCE Our results demonstrate that the pig can be infected with M. ulcerans. Productive infection leads to the development of lesions that closely resemble human BU lesions. The pig infection model therefore has great potential for studying the early pathogenesis of BU and for the development of new therapeutic and prophylactic interventions.

The immunology of the porcine skin and its value as a model for human skin.

The porcine skin has striking similarities to the human skin in terms of general structure, thickness, hair follicle content, pigmentation, collagen and lipid composition. This has been the basis for numerous studies using the pig as a model for wound healing, transdermal delivery, dermal toxicology, radiation and UVB effects. Considering that the skin also represents an immune organ of utmost importance for health, immune cells present in the skin of the pig will be reviewed. The focus of this review is on dendritic cells, which play a central role in the skin immune system as they serve as sentinels in the skin, which offers a large surface area exposed to the environment. Based on a literature review and original data we propose a classification of porcine dendritic cell subsets in the skin corresponding to the subsets described in the human skin. The equivalent of the human CD141(+) DC subset is CD1a(-)CD4(-)CD172a(-)CADM1(high), that of the CD1c(+) subset is CD1a(+)CD4(-)CD172a(+)CADM1(+/low), and porcine plasmacytoid dendritic cells are CD1a(-)CD4(+)CD172a(+)CADM1(-). CD209 and CD14 could represent markers of inflammatory monocyte-derived cells, either dendritic cells or macrophages. Future studies for example using transriptomic analysis of sorted populations are required to confirm the identity of these cells.

Time for a break: admissions to an urban emergency department after working out-a retrospective study from Switzerland.

Background. The present retrospective study was intended to investigate whether working out and other low-speed sports can provoke cardiovascular, neurological, or traumatic damage. Material and Methods. Patient data from 2007 to 2013 was collected and saved at the university department of emergency medicine in an electronic patient record database. Results. Of the 138 patients included in this study, 83.3% (n = 115) were male and 16.7% female (n = 23). Most admissions were due to musculoskeletal accidents (n = 77; 55.8%), followed by neurological incidents (n = 23; 16.7%), cardiovascular incidents (n = 19; 13.8%), soft tissue injuries (n = 3; 2.2%), and others (n = 16; 11.6%). The mean age of the allover injured people was 36.7 years. The majority of the patients (n = 113; 81.9%) were treated as outpatients; 24 (17.4%) were inpatients. Discussion. In Switzerland, this is the first study that describes emergency department admissions after workout and examines trauma and neurological and cardiovascular incidents. As specific injuries, such as brain haemorrhages, STEMIs, and epileptic seizures, were relatively frequent, it was hypothesised that workout with its physiological changes may be an actual trigger for these injuries, at least for a specific population. Conclusion. Strenuous physical activity may trigger the risk of cardiovascular, neurological, or trauma events.

Identification, quantification, spatiotemporal distribution and genetic variation of major latex secondary metabolites in the common dandelion (Taraxacum officinale agg.)

The secondary metabolites in the roots, leaves and flowers of the common dandelion (Taraxacum officinale agg.) have been studied in detail. However, little is known about the specific constituents of the plant’s highly specialized laticifer cells. Using a combination of liquid and gas chromatography, mass spectrometry and nuclear magnetic resonance spectrometry, we identified and quantified the major secondary metabolites in the latex of different organs across different growth stages in three genotypes, and tested the activity of the metabolites against the generalist root herbivore Diabrotica balteata. We found that common dandelion latex is dominated by three classes of secondary metabolites: phenolic inositol esters (PIEs), triterpene acetates (TritAc) and the sesquiterpene lactone taraxinic acid β-d-glucopyranosyl ester (TA-G). Purification and absolute quantification revealed concentrations in the upper mg g−1 range for all compound classes with up to 6% PIEs, 5% TritAc and 7% TA-G per gram latex fresh weight. Contrary to typical secondary metabolite patterns, concentrations of all three classes increased with plant age. The highest concentrations were measured in the main root. PIE profiles differed both quantitatively and qualitatively between plant genotypes, whereas TritAc and TA-G differed only quantitatively. Metabolite concentrations were positively correlated within and between the different compound classes, indicating tight biosynthetic co-regulation. Latex metabolite extracts strongly repelled D. balteata larvae, suggesting that the latex constituents are biologically active.

The Role of Plant Primary and Secondary Metabolites in Root-Herbivore Behaviour, Nutrition and Physiology

Many insect herbivores feed on belowground plant tissues. In this chapter, we discuss how they have adapted to deal with root primary and secondary metabolites. It is becoming evident that root herbivores can use root volatiles and exudates for host location and foraging. Their complex sensory apparatus suggests a sophisticated recognition and signal transduction system. Furthermore, endogenous metabolites trigger attractive or repellent responses in root feeders, indicating that they may specifically fine-tune food uptake to meet their dietary needs. Little evidence for direct toxic effects of root secondary metabolites has accumulated so far, indicating high prevalence of tolerance mechanisms. Root herbivores furthermore facilitate the entry of soil microbes into the roots, which may influence root nutritional quality. Investigating the role of plant metabolites in an ecologically and physiologically relevant context will be crucial to refine our current models on root-herbivore physiology and behaviour in the future.

Interlaboratory variability of MIB1 staining in well-differentiated pancreatic neuroendocrine tumors

Neuroendocrine tumors (NET) are routinely graded and staged to judge prognosis. Proliferation index using MIB1 staining has been introduced to assess grading. There are vivid discussions on cutoff definitions, automated counting, and interobserver variability. However, no data exist regarding interlaboratory reproducibility for low proliferation indices which are of importance to discriminate between G1 and G2 NET. We performed MIB1 staining in three different university hospital-based pathology laboratories on a tissue micro array (TMA) of a well-characterized patient cohort, containing pancreatic NET of 61 patients. To calculate the proliferation index, number of positive tumor nuclei was divided by the total number of tumor nuclei. Labeling index was compared to mitotic counts in whole tissue sections and to clinical outcome. Linear regression analysis, intraclass comparison, and log-rank analysis were performed. Intraclass correlation showed moderate-to-fair agreement. Especially low proliferating tumors were affected by interlaboratory differences. Log-rank analysis was performed for each lab and resulted in three different cutoffs (5.0, 3.0, and 0.5 %). Every calculated cutoff stratified the patient cohort to a significant extent for the underlying stain (p < 0.001, <0.001, and <0.001) but showed no or lesser significance when applied to the other stains. Significant and relevant interlab differences for MIB1 exist. Since the MIB1 proliferation index influences grading, local cutoffs or external standardization should urgently be introduced to achieve reliability and reproducibility.

A Latex Metabolite Benefits Plant Fitness under Root Herbivore Attack

Plants produce large amounts of secondary metabolites in their shoots and roots and store them in specialized secretory structures. Although secondary metabolites and their secretory structures are commonly assumed to have a defensive function, evidence that they benefit plant fitness under herbivore attack is scarce, especially below ground. Here, we tested whether latex secondary metabolites produced by the common dandelion (Taraxacum officinale agg.) decrease the performance of its major native insect root herbivore, the larvae of the common cockchafer (Melolontha melolontha), and benefit plant vegetative and reproductive fitness under M. melolontha attack. Across 17 T. officinale genotypes screened by gas and liquid chromatography, latex concentrations of the sesquiterpene lactone taraxinic acid β-D-glucopyranosyl ester (TA-G) were negatively associated with M. melolontha larval growth. Adding purified TA-G to artificial diet at ecologically relevant concentrations reduced larval feeding. Silencing the germacrene A synthase ToGAS1, an enzyme that was identified to catalyze the first committed step of TA-G biosynthesis, resulted in a 90% reduction of TA-G levels and a pronounced increase in M. melolontha feeding. Transgenic, TA-G-deficient lines were preferred by M. melolontha and suffered three times more root biomass reduction than control lines. In a common garden experiment involving over 2,000 T. officinale individuals belonging to 17 different genotypes, high TA-G concentrations were associated with the maintenance of high vegetative and reproductive fitness under M. melolontha attack. Taken together, our study demonstrates that a latex secondary metabolite benefits plants under herbivore attack, a result that provides a mechanistic framework for root herbivore driven natural selection and evolution of plant defenses below ground.

A Lentiviral Vector Expressing Japanese Encephalitis Virus-like Particles Elicits Broad Neutralizing Antibody Response in Pigs.

BACKGROUND Japanese encephalitis virus (JEV) is the major cause of viral encephalitis in Southeast Asia. Vaccination of domestic pigs has been suggested as a "one health" strategy to reduce viral disease transmission to humans. The efficiency of two lentiviral TRIP/JEV vectors expressing the JEV envelope prM and E glycoproteins at eliciting protective humoral response was assessed in a mouse model and piglets. METHODOLOGY/PRINCIPAL FINDINGS A gene encoding the envelope proteins prM and E from a genotype 3 JEV strain was inserted into a lentiviral TRIP vector. Two lentiviral vectors TRIP/JEV were generated, each expressing the prM signal peptide followed by the prM protein and the E glycoprotein, the latter being expressed either in its native form or lacking its two C-terminal transmembrane domains. In vitro transduction of cells with the TRIP/JEV vector expressing the native prM and E resulted in the efficient secretion of virus-like particles of Japanese encephalitis virus. Immunization of BALB/c mice with TRIP/JEV vectors resulted in the production of IgGs against Japanese encephalitis virus, and the injection of a second dose one month after the prime injection greatly boosted antibody titers. The TRIP/JEV vectors elicited neutralizing antibodies against JEV strains belonging to genotypes 1, 3, and 5. Immunization of piglets with two doses of the lentiviral vector expressing JEV virus-like particles led to high titers of anti-JEV antibodies, that had efficient neutralizing activity regardless of the JEV genotype tested. CONCLUSIONS/SIGNIFICANCE Immunization of pigs with the lentiviral vector expressing JEV virus-like particles is particularly efficient to prime antigen-specific humoral immunity and trigger neutralizing antibody responses against JEV genotypes 1, 3, and 5. The titers of neutralizing antibodies elicited by the TRIP/JEV vector are sufficient to confer protection in domestic pigs against different genotypes of JEV and this could be of a great utility in endemic regions where more than one genotype is circulating.