The Family of Chloride Channel Regulator, Calcium-activated Proteins in the Feline Respiratory Tract: A Comparative Perspective on Airway Diseases in Man and Animal Models.

Members of the chloride channel regulator, calcium-activated (CLCA) family are considered to be modifiers in inflammatory, mucus-based respiratory conditions such as asthma and cystic fibrosis. Previous work has shown substantial differences between human and murine CLCA orthologues that limit the value of mouse models. As an alternative, the cat is an unfamiliar but powerful model of human asthma. We therefore characterized the expression profiles of CLCA proteins in the feline respiratory tract. Identical to other species, the feline CLCA1 protein was immunohistochemically localized to virtually all goblet cells and found to be secreted into the mucus. However, it was not detected in submucosal glands where it is expressed in other species. In contrast to all other species studied to date, feline CLCA2 was not found in submucosal glands or any other airway cells. Similar to mice, but in contrast to man and pigs, the feline respiratory tract was devoid of CLCA4 expression. In the airways of asthmatic cats, CLCA1 was strongly overexpressed, similar to human patients. Therefore, despite some similarities in CLCA1 protein expression and secretion, substantial differences were identified between several feline CLCA family members and their respective orthologues in man, mice and pigs, which must be considered in comparative medicine.

Tumour, but not Age-associated, Increase of Senescence Markers γH2AX and p21 in the Canine Eye.

Senescent cells display an irreversible cell cycle arrest with resistance to apoptosis. They are known to accumulate with age in mice, monkeys and man, and are suspected to drive the development and progression of neoplasia. Eyes develop age-associated changes, most commonly in the retina, cornea and lens. The aim of this study was to test whether senescent cells increase with age in the canine eye in general and in the microenvironment of ocular tumours in particular. The senescence markers γH2AX and p21 were tested in young (n = 10, age ≤2 years) versus old (n = 9, age range 9.5-12.4 years) canine eyes, as well as in the microenvironment of intraocular tumours, namely uveal melanocytomas (n = 13) and ciliary body adenomas (n = 9). To consider a potential association of senescence with biological behaviour, we compared the expression of both markers in tumour cells of benign uveal melanocytomas (n = 13) versus malignant conjunctival melanomas (n = 7). Canine eyes showed no age-dependent changes in senescent cells. However, a significant increase of the percentage of γH2AX- or p21-labelled cells was found in the retina, uvea and lens of tumour-bearing eyes. Tumour cells in conjunctival melanomas had a significantly increased percentage of p21-expressing cells compared with uveal melanocytomas. We conclude, that senescent cells do not accumulate with age in otherwise normal canine eyes and that a senescent microenvironment of intraocular tumours is unlikely to be age driven. In addition, as in man, the percentage of p21-positive cells was increased in melanomas, supporting the theory that malignant tumours may override the senescence-associated cell cycle arrest.

Soft X-ray microscopy for probing of topical tacrolimus delivery via micelles.

The penetration of topically applied tacrolimus formulated in micelles into murine skin is reported, measured by X-ray microscopy. Tacrolimus and micelles are probed for the first time by this high spatial resolution technique by element-selective excitation in the C 1s- and O 1s-regimes. This method allows selective detection of the distribution and penetration depth of drugs and carrier molecules into biologic tissues. It is observed that small, but distinct quantities of the drug and micelles, acting as a drug carrier, penetrate the stratum corneum. A comparison is made with the paraffin-based commercial tacrolimus ointment Protopic®, where local drug concentrations show to be low. A slight increase in local drug concentration in the stratum corneum is observed, if tacrolimus is formulated in micelles, as compared to Protopic®. This underscores the importance of the drug formulations for effective drug delivery. Time-resolved penetration shows presence of drug in the stratum corneum 100 min after formulation application, with penetration to deeper skin layers at 1000 min. High resolution micrographs give indications for a penetration pathway along the lipid membranes between corneocytes, but also suggest that the compound may penetrate corneocytes.

Establishment of a Mucin Secreting Cell Line Cx-03 from an Uterine Carcino Sarcoma.

PURPOSE: The identification of novel cell lines which combine the most important properties of mucosal membranes in terms of drug absorption, transmembrane transport and mucus secretion can help to establish improved and meaningful test systems for pharmacological and infectiological studies. METHODS: We have established a novel mucus secreting tumor cell line (Cx-03) derived from a female patient who underwent radical hysterectomy after diagnosis of a large malignant carcino sarcoma (Muellerian mixed tumor). Via xenotransplantation in SCID beige mice, recultivation and subcloning a stable cell line was established from primary tumor cells. RESULTS: Human origin and novelty of the cell line was determined by karyotype analysis and STR fingerprint. During growth cells produce considerable amounts of a PAS positive viscoelastic mucus. Immunostaining revealed expression of mucins and the mucin modifier CLCA1. We demonstrate in initial electrophysiological experiments that confluent, polarized monolayers of Cx-03 are formed (on PCF-filter supports) that exhibit stable electrical resistance (> 600 Ω cm2). Confluent Cx-03 monolayers express barrier-forming tight junction proteins claudin-1 and -4 which co-localize with zonula occludens protein-1 (ZO-1) at cell-cell contacts. CONCLUSIONS: Mucus secretion is a rare property among mammalian cell lines. In combination with its ability to form polarized monolayers Cx-03 might contribute as a novel cell based model for drug absorption, transport and barrier studies.

Evaluation of clinical, laboratory, imaging findings and outcome in 99 dogs with leptospirosis.

OBJECTIVE: To report clinical, laboratory and diagnostic imaging features and prognostic factors in dogs with leptospirosis from North-East Germany. MATERIALS AND METHODS: Medical records of dogs diagnosed with leptospirosis from 2006 to 2013 were evaluated retrospectively. RESULTS: The study included 99 dogs. At initial presentation, the most common clinical signs were lethargy (96%), anorexia (88%), vomiting (85%), painful abdomen (39%), diarrhoea (38%), oliguria (27%) and tachypnoea (26%). Abnormal laboratory findings included anaemia (63%), thrombocytopenia (63%), leucocytosis (57%), increase of plasma urea (84%) and creatinine concentrations (81%), increased liver enzyme activities (80%), hyperbilirubinaemia (69%), hyperphosphataemia (67%), hyponatraemia (64%), hypoalbuminaemia (55%) and hypokalaemia (29%). Radiological pulmonary changes were detected in 57% of the dogs initially or during the course of disease. Severe dyspnoea, oliguria, azotaemia, hyperbilirubinaemia and severe radiological pulmonary changes were more often found in dogs that did not survive. There was renal, hepatic and pulmonary involvement in 95, 92 and 58% of the dogs, respectively, and multi-organ lesions in 98 dogs (98%); 32 dogs died or were euthanased. CONCLUSION: Several clinical and laboratory abnormalities were associated with a negative outcome; severe lung involvement was specifically associated with high mortality.

Mechanisms of tumour resistance against chemotherapeutic agents in veterinary oncology.

Several classes of chemotherapy drugs are used as first line or adjuvant treatment of the majority of tumour types in veterinary oncology. However, some types of tumour are intrinsically resistant to several anti-cancer drugs, and others, while initially sensitive, acquire resistance during treatment. Chemotherapy often significantly prolongs survival or disease free interval, but is not curative. The exact mechanisms behind intrinsic and acquired chemotherapy resistance are unknown for most animal tumours, but there is increasing knowledge on the mechanisms of drug resistance in humans and a few reports on molecular changes in resistant canine tumours have emerged. In addition, approaches to overcome or prevent chemotherapy resistance are becoming available in humans and, given the overlaps in molecular alterations between human and animal tumours, these may also be relevant in veterinary oncology. This review provides an overview of the current state of research on general chemotherapy resistance mechanisms, including drug efflux, DNA repair, apoptosis evasion and tumour stem cells. The known resistance mechanisms in animal tumours and the potential of these findings for improving treatment efficacy in veterinary oncology are also explored.

Toltrazuril does not show an effect against pigeon protozoal encephalitis.

The protozoan parasite Sarcocystis calchasi causes a severe neurologic disease in domestic pigeons (Columba livia f. dom.) named pigeon protozoal encephalitis. Recently, the parasite has also been reported in psittacines causing a virtually identical disease with fatal outcome. So far, an etiological treatment of S. calchasi infections in pigeons or psittacines is unknown. The present study evaluates the effectiveness of the anticoccidian drug toltrazuril against S. calchasi and the influence of the timepoint of treatment. Therefore, nine domestic pigeons were inoculated with 400 S. calchasi sporocysts and treated with toltrazuril (25 mg/kg) in groups of three pigeons each at dpi 10/11 and dpi 40/41 and on two consecutive days at the onset of neurologic signs. After euthanasia at dpi 73, tissue samples including brain and skeletal muscles were examined by histology and S. calchasi-specific real-time PCR. All pigeons independent of the group developed neurologic signs from dpi 49 onwards. Histology identified sarcocysts in the skeletal muscles and a granulomatous encephalitis in the brains. The relative amount of S. calchasi DNA was on a comparable level in all pigeons. Consequently, toltrazuril was demonstrated to be not effective against S. calchasi with the applied treatment regime. Longer treatment periods or agents other the toltrazuril may be considered for further investigations. So far, preventive measures like roofing of aviaries for prevention of infection and regular disinfection remain the most important factor in the control of S. calchasi infections.

Electroencephalographic evaluation of the effectiveness of blunt trauma to induce loss of consciousness for on-farm killing of chickens and turkeys.

Euthanasia of small numbers of birds in case of injury or other illness directly on the farm may be necessary for welfare reasons. This should be done without transportation of the moribund animals in order to minimize pain and distress. Blood loss has to be avoided to minimize the risk of contaminating the environment. Cervical dislocation in combination with a blunt trauma may be an appropriate way to achieve this aim but the bird's age and body weight may influence the practicability of this method in the field. In this study, we evaluated broilers, broiler breeders, and turkeys of different age groups and weights up to nearly 16 kg for the efficacy of blunt trauma to induce unconsciousness, allowing subsequent killing of the bird without pain. The effect of blunt trauma on the brain was determined by electroencephalography (EEG). Auditory evoked potentials (AEPs) were recorded for each animal. Convulsions or tonic seizures were observed in all investigated animals after blunt trauma, including strong wing movements, torticollis, and stretching of legs. The EEG results demonstrate that the blunt trauma induced by a single, sufficiently strong hit placed in the frontoparietal region of the head led to a reduction or loss of the AEP in all groups of birds. These results clearly indicate a loss of sensibility and induction of unconsciousness, which would allow painless killing of the birds immediately after the induction of the blunt trauma.

Moxifloxacin is not anti-inflammatory in experimental pneumococcal pneumonia.

OBJECTIVES: Anti-inflammatory functions of antibiotics may counteract deleterious hyperinflammation in pneumonia. Moxifloxacin reportedly exhibits immunomodulatory properties, but experimental evidence in pneumonia is lacking. Therefore, we investigated moxifloxacin in comparison with ampicillin regarding pneumonia-associated pulmonary and systemic inflammation and lung injury. METHODS: Ex vivo infected human lung tissue and mice with pneumococcal pneumonia were examined regarding local inflammatory response and bacterial growth. In vivo, clinical course of the disease, leucocyte dynamics, pulmonary vascular permeability, lung pathology and systemic inflammation were investigated. In addition, transcellular electrical resistance of thrombin-stimulated endothelial cell monolayers was quantified. RESULTS: Moxifloxacin reduced cytokine production in TNF-α-stimulated, but not in pneumococci-infected, human lung tissue. In vivo, moxifloxacin treatment resulted in reduced bacterial load as compared with ampicillin, whereas inflammatory parameters and lung pathology were not different. Moxifloxacin-treated mice developed less pulmonary vascular permeability during pneumonia, but neither combination therapy with moxifloxacin and ampicillin in vivo nor examination of endothelial monolayer integrity in vitro supported direct barrier-stabilizing effects of moxifloxacin. CONCLUSIONS: The current experimental data do not support the hypothesis that moxifloxacin exhibits potent anti-inflammatory properties in pneumococcal pneumonia.

Prevalence of biofilms on surgical suture segments in wounds of dogs, cats, and horses.

The formation of biofilms on surgical implants is thought to play a major role in chronic infection and wound-healing disorders and has been rarely described in veterinary medicine. Due to poor and unreliable results from bacterial culturing, histology may be an economic tool for the detection of biofilms. In this study, the prevalence of biofilms on surgical suture materials and swabs with chronic wound-healing complications in dogs, cats, and horses was assessed by histologic examination using hematoxylin and eosin, Gram, and Giemsa stains, as well as periodic acid-Schiff reaction. Of the 91 tissue samples with intralesional suture material or swab residues associated with inflammation, only 2 contained bacterial colonies arranged in an extracellular polymeric matrix consistent with a biofilm. The results of this study suggest that biofilms on suture material may occur in veterinary medicine.

Polar bear encephalitis: establishment of a comprehensive next-generation pathogen analysis pipeline for captive and free-living wildlife.

This report describes three possibly related incidences of encephalitis, two of them lethal, in captive polar bears (Ursus maritimus). Standard diagnostic methods failed to identify pathogens in any of these cases. A comprehensive, three-stage diagnostic 'pipeline' employing both standard serological methods and new DNA microarray and next generation sequencing-based diagnostics was developed, in part as a consequence of this initial failure. This pipeline approach illustrates the strengths, weaknesses and limitations of these tools in determining pathogen caused deaths in non-model organisms such as wildlife species and why the use of a limited number of diagnostic tools may fail to uncover important wildlife pathogens.

Next Generation Sequencing Analysis of Biofilms from Three Dogs with Postoperative Surgical Site Infection.

The composition of biofilms in chronic wound infections of dogs is unclear. In the present study, histologically identified biofilms attached to sutures in chronically infected wounds of three dogs were examined by next generation sequencing of total DNA extracted from formalin-fixed and paraffin-embedded tissue samples. The analysis identified an inhomogeneous bacterial composition in three tissues containing biofilms. Some of the identified bacterial families such as Staphylococci and Streptococci have been found before in biofilms associated with human and canine wounds but in this study were quantitatively in the minority. The majority of the reads classified as bacterial sequences had the highest identity with sequences belonging to the Porphyromonadaceae, Deinococcaceae, Methylococcaceae, Nocardiaceae, Alteromonadaceae, and Propionibacteriaceae and thus taxons of so far minor relevance in veterinary medicine.

[Disturbances of water metabolism in two dogs and one cat with central nervous system disorders]. / Störungen des Wasserhaushaltes bei zwei Hunden und einer Katze mit ZNS-Erkrankungen.

Hypernatremia due to different pathophysiological mechanisms results in a rise in plasma osmolality. Dependent on its severity and on the speed of its development hyperosmolality can be life-threatening. This article describes 2 dogs and 1 cat with central nervous system disorders (adenoma of the pituitary gland, cerebral trauma). All patients developed normovolemic hypernatremia due to pituitary gland and hypothalamus dysfunction, respectively. Plasma sodium concentrations ranged from 163 to 185 mmol/l. Neurological examinations revealed lethargy, disturbances of consciousness, and ataxia, respectively. The dogs had to be euthanased due to the grave prognosis, the cat with cerebral trauma survived.

Le développement d'une hypenatrémie peut avoir plusieurs mécanismes patho-physiologiques. Dans ces cas, il se produit toujours une élévation de l'osmolarité du plasma. Selon l'importance de l'hypernatrémie et la vitesse de l'apparition, une hyperosmolarité peut mettre la vie en danger. Dans le présent article, on décrit des affections du système nerveux central chez deux chiens (adénome de l'hypophyse) et un chat (trauma crânien) ayant développé une hypernatrémie normovolémique suite à un dysfonctionnement de l'hypophyse ou de l'hypothalamus. Les concentrations plasmatiques de sodium étaient comprises entre 163 et 185 mmol/l. Les animaux présentaient de la léthargie, des troubles de la conscience et de l'ataxie. Vu le mauvais pronostic, les chiens ont dû être euthanasiés, le chat victime d'un traumatisme crânien a survécu.

Molecular quantification of canine specific microRNA species.

MicroRNAs (miRNAs) belong to the heterogeneous group of non-coding, regulatory RNA molecules. They play an important role in physiological functions, especially during tissue development. Moreover, their cell-type specific expression levels are also thought to be altered in association with different pathological conditions, including metabolic disorders and cancer. However, the vast majority of molecular assays for their quantification have been established for humans and mice, with no reports on specific research tools for dogs. Here canine-specific SYBRGreen based quantitative, real-time PCR assays are introduced for the quantification of 21 miRNAs and five small nucleolar RNA (snoRNA). The assay includes a time-saving and economical universal one-tube cDNA synthesis approach which allows for a more robust relative quantification than the commonly used multiple specific reverse transcriptions. GeNorm and NormFinder analysis were used for the evaluation of potential housekeeping genes and identified miRNAs to be more stable housekeeping genes by trend.

Canine cutaneous histiocytomas are clonal lesions as defined by X-linked clonality testing.

Canine cutaneous histiocytoma (CCH) is the most common skin tumour of young dogs. CCH is assumed to be a tumour, but as these lesions often undergo complete regression, they have also been proposed to represent hamartomas or unregulated hyperplasia of polyclonal histiocytic cells. To demonstrate a monoclonal origin of CCH, and thereby a probable neoplastic nature, a clonality assay was established based on the heterozygosity of a polymorphic microsatellite within the canine androgen receptor located on the X chromosome. Analysis of 11 histiocytomas identified a non-random X chromosome inactivation of one androgen receptor allele. CCH may, therefore, be a clonal lesion and of neoplastic nature.

All subunits of the interleukin-2 receptor are expressed by canine cutaneous mast cell tumours.

Cutaneous mast cell tumours (MCTs) are among the most important skin tumours in dogs. Apart from c-KIT mutations, which are present in <18% of MCTs, little is known of the mechanisms of MCT development and independent growth of tumour cells. Recently, the α-subunit (CD25) of the interleukin (IL)-2 receptor (IL-2R) has been found to be expressed by canine cutaneous MCTs and this expression is negatively correlated with tumour grade. We thus hypothesized that the other two subunits of the IL-2R and the ligand IL-2 are also expressed and that IL-2-dependent pathways may have an impact on MCT development and independent tumour cell growth. Messenger RNA and protein expression levels of the IL-2R ß-subunit (CD122), the IL-2R γ-subunit (CD132) and IL-2 were analyzed in canine cutaneous MCTs and compared with tumour grade and c-KIT mutation status. Eighty-six percent of the tumours expressed both subunits of the IL-2R and 64% expressed IL-2. In addition, neoplastic mast cells seem able to bind IL-2. IL-2Rγ and IL-2 protein expression levels were significantly decreased in higher grade tumours and IL-2 expression was significantly decreased in c-KIT mutated tumours. Thus, expression of the complete IL-2R and its ligand by canine cutaneous MCTs indicates a potential impact of IL-2R signalling in MCT development and tumour cell proliferation. The decrease in IL-2R expression with increasing histological evidence of malignancy suggests that the IL-2R may be more relevant for early MCT development and well-differentiated tumours.

Multiple RT-PCR markers for the detection of circulating tumour cells of metastatic canine mammary tumours.

In humans, detection of circulating tumour cells (CTCs) using nucleic acid-based methods such as reverse transcription polymerase chain reaction (RT-PCR) has proven to be of prognostic relevance. However, similar procedures are still lacking in veterinary oncology. To assess the correlation of CTC markers with the metastatic potential of canine mammary tumours, 120 peripheral blood samples from bitches with mammary carcinomas with (group 1) and without (group 2) histological evidence of vascular invasion and/or presence of lymph node metastases and mammary adenomas (group 3) were analyzed. Blood samples were collected in EDTA tubes and RNA was extracted within 48 h. Subsequently, the samples were tested by RT-PCR for a panel of seven CTC mRNA markers. CRYAB was the most sensitive single marker with a sensitivity of 35% and also the most specific marker with a specificity of 100% to detect group 1 blood samples. A multimarker assay combining four genes enhanced the sensitivity up to 77.5%, but decreased the specificity to 80%. CRYAB appeared to be highly specific but only moderately sensitive at detecting blood samples from dogs with metastatic tumours and detection significantly correlated with vascular invasion of primary mammary tumours. However, a multimarker assay of four genes significantly enhanced the sensitivity of the assay and is therefore preferable for CTC detection.

Tandem duplication of KIT exon 11 influences the proteome of canine mast cell tumours.

Mutations with permanent activation of the stem cell factor receptor KIT have been identified as one potential cause for canine cutaneous mast cell tumours (MCTs). The exact changes in global gene expression patterns associated with permanent activation of KIT in these tumours are unknown. The present study compares, by the use of two dimensional difference gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, the proteomes of canine MCTs, with and without KIT exon 11 tandem duplication. Fifteen differentially expressed proteins were identified in mutated MCTs. These are mainly involved in cytoskeleton structure and cell motility (ACTR2, ACTB and CAPPA1), cell signalling (ARHGDIA) and lipid metabolism (ALOX15 and ACSBG4), or are serum proteins. The results therefore support the notion that KIT mutation is associated with changes in the proteome of affected cells with a major effect on the composition of the cytoskeletal proteome and cell motility proteins. No overlaps were identified when the results were compared with a recent study on the proteomic differences between low- and high-grade tumours, suggesting that KIT-mutated tumours may be regarded as a separate entity of high-grade tumours with potential relevance to therapeutic strategies.

Canine cutaneous peripheral nerve sheath tumours versus fibrosarcomas can be differentiated by neuroectodermal marker genes in their transcriptome.

The diagnostic differentiation between canine fibrosarcomas and peripheral nerve sheath tumours (PNSTs) is based on histopathological phenotype. Histological differentiation of these tumours can, however, be challenging and there is a lack of immunohistochemical markers to prove their histogenic origin. To identify possible PNST markers and to further characterize their histogenic origin we compared histologically well-defined canine fibrosarcomas and PNSTs by cDNA microarray analysis. Forty-five annotated gene products were significantly differentially expressed between both tumour types. Seven of these gene products, known to be specifically expressed in neuroectodermal tissues, had higher expression levels in PNSTs: FMN2, KIF1B, GLI1, ROBO1, NMUR2, DOK4 and HMG20B. Conversely, eight genes associated with carcinogenesis had higher expression in fibrosarcomas: FHL2, PLAGL1, FNBP1L, BAG2, HK1, CSK and Cox5A. Comparison of the fibrosarcoma and PNST transcriptome therefore identified PNST phenotype-associated genes involved in neuroectodermal differentiation, which may be useful as diagnostic markers. Furthermore, the genes associated with the fibrosarcoma phenotype may serve as markers to differentiate fibrosarcomas from other tumour types.