Flat Coatings Research Articles

Clinical conundrum

Giorgia Brambilla graduated from Bristol University in July 2018 and she is currently working in an independent small animal practice in the Yorkshire. She invited Companion readers to consider the cause of vomiting and weight loss in a Flat-Coated Retriever.

Genome-wide DNA copy number analysis and targeted transcriptional analysis of canine histiocytic malignancies identifies diagnostic signatures and highlights disruption of spindle assembly complex.

Canine histiocytic malignancies (HM) are rare across the general dog population, but overrepresented in certain breeds, such as Bernese mountain dog and flat-coated retriever. Accurate diagnosis relies on immunohistochemical staining to rule out histologically similar cancers with different prognoses and treatment strategies (e.g., lymphoma and hemangiosarcoma). HM are generally treatment refractory with overall survival of less than 6months. A lack of understanding regarding the mechanisms of disease development and progression hinders development of novel therapeutics. While the study of human tumors can benefit veterinary medicine, the rarity of the suggested orthologous disease (dendritic cell sarcoma) precludes this. This study aims to improve the understanding of underlying disease mechanisms using genome-wide DNA copy number and gene expression analysis of spontaneous HM across several dog breeds. Extensive DNA copy number disruption was evident, with losses of segments of chromosomes 16 and 31 detected in 93% and 72% of tumors, respectively. Droplet digital PCR (ddPCR) evaluation of these regions in numerous cancer specimens effectively discriminated HM from other common round cell tumors, including lymphoma and hemangiosarcoma, resulting in a novel, rapid diagnostic aid for veterinary medicine. Transcriptional analysis demonstrated disruption of the spindle assembly complex, which is linked to genomic instability and reduced therapeutic impact in humans. A key signature detected was up-regulation of Matrix Metalloproteinase 9 (MMP9), supported by an immunohistochemistry-based assessment of MMP9 protein levels. Since MMP9 has been linked with rapid metastasis and tumor aggression in humans, the data in this study offer a possible mechanism of aggression in HM.

Изучение эффективности комплексного инсектоакарицидного препарата «РольфКлуб 3D шампунь» при лечении эктопаразитозов собак и кошек

The purpose of the research is to study the efficiency of complex medicinal product for veterinary use "RolfClub 3D shampoo” for treatment of dogs’ and cats’ ectoparasitosis. Materials and methods . Cats and dogs affected by fleas Ctenocephalides felis and C. canis, lice Felicola subrostratus and Trichodectes canis, sucking lice Linognathus setosus were selected for the experiment. Presence of specific disease symptoms (pruritus, rumpled and flat coat, scratchings, and places of hair removal) was noted at the time of visual examination of animals’ dermatic hair-coat covering. All infected animals were divided into experimental and control groups. Complex insectoacaricide drug "RolfClub 3D shampoo” ("SPC "Ecoprom") in the form of solution was administered according to the instruction. Before dressing animals’ dermatic hair-coat covering was richly washed by warm water, then the drug was applied at a rate of 1 ml per 1 kg of body weight spreading throughout surface of dermatic hair-coat covering and slightly rubbing till foaming avoiding contact with eyes, ears, and avoiding licking off drug by animals. Shampoo was carefully washed out with warm water in 5–7 minutes. Zoohygienical shampoo was used for the animals from control group. In 24 hours, 2, 5, 10 days shampoo efficiency was evaluated on the basis of calculation of amount of ectoparasites before and after single dressing by the drug "RolfClub 3D shampoo”. Results and discussion . It has been established that the drug "RolfClub 3D shampoo” has significant insecticide effect. Single animals’ dressing by the drug "RolfClub 3D shampoo” provided death of fleas, sucking lice, lice. In 24 hours, 2, 5, 10 days after beginning of experiment all treated animals were free of ectoparasites (fleas, sucking lice, lice). Therapeutic drug efficiency was 100% in the case of all ectoparasites diseases (ctenocephalosis, linognatozis, trichodectozis). Side effects and events were not identified in the case of drug administration.

Low-secondary electron emission yield under electron bombardment of microstructured surfaces, looking for multipactor effect suppression

The reduction of the total secondary electron emission during electron-matter interactions is required to improve the maximum power limit of the vacuum RF equipments prone to multipactor discharge. In this work, a chemical deposition technique was developed to create the appropriate micron or submicron surface roughness to significantly improve the typical characteristics of the flat silver coatings used for high-power microwave devices for space applications. Rough silver coated RF filters with a high surface aspect ratio, >3, was achieved. It is found that the secondary electron emission yield (SEY) remains lower than 1 throughout the primary electron energy range and therefore multipactor electron avalanche is avoided. The influence of aging on the multipactor discharge is also drastically reduced in rough silver coatings. An experimental linear correlation was found between the multipactor power level and the minimum interaction energy for which the number of incident and emitted electrons is equal.

Lomustine chemotherapy for the treatment of presumptive haemophagocytic histiocytic sarcoma in Flat‐coated Retrievers

The Flat-coated Retriever (FCR) is a breed at-risk for histiocytic sarcoma (HS). A haemophagocytic form of HS (HPHS) occurs in the spleen ± other sites such as bone marrow, and is a CD11d+ disease of macrophage origin. Patients with HPHS typically present with regenerative anaemia. Lomustine is a well-accepted, first-line chemotherapy for dogs with HS, but its specific utility in dogs with HPHS has not been previously reported. A cohort of 10 dogs presumptively diagnosed with HPHS via splenic ± bone marrow or liver aspiration cytology were treated with lomustine, plus supportive medications as required. Cytology of liver and bone marrow was diagnostically useful in patients where splenic cytology was less convincing. No dogs experienced significant constitutional or gastrointestinal adverse effects following lomustine administration, though most dogs displayed clinical signs associated with the underlying disease. No patients appeared to derive discernible clinical benefit from chemotherapy. Neutropenia was a common adverse effect of lomustine. Concurrent medications included corticosteroids in all cases, prior to the diagnosis of HPHS, for a provisional diagnosis of immune-mediated haemolytic anaemia. Median survival time of the treated dogs was 24 days from diagnosis (range, 4-67 days). HPHS affecting FCRs appears to have a uniformly poor outcome and is rapidly fatal. Lomustine chemotherapy was unsuccessful in significantly improving outcome in this cohort of patients. Further study of this rare and devastating disease is needed.

Improvement of the Reflectivity of Flat Coatings

Consideration is given to the possibility of improving the reflectivity of a flat reflecting surface using the nonabsorbing coating of assigned thickness applied to it.

Low pressure chemical vapour deposition of BN: Relationship between gas phase chemistry and coating microstructure

The structural and morphological characteristics of flat BN coatings processed by chemical vapour deposition, using BCl3−NH3−H2 gas mixtures at low pressure (P < 1 kPa), have been investigated as a function of the deposition temperature (ranging from 900 °C to 1400 °C) and the total gas flow rate. The resulting BN coatings are mainly turbostratic but with heterogeneous microstructures, i.e. mixtures of poorly and highly organized domains. The structural homogeneity and the degree of crystallization depend notably on the nature of the dilution gas (either H2 or Ar) and the depletion of gas species. The decrease of the apparent activation energy from 80 kJ.mol−1 below 1200 °C to 40 kJ.mol−1 above 1200 °C reflects a change in the deposition regime. Ex situ Fourier transform infrared analysis of the residual gas mixture allowed intermediate species leading to poorly or highly organized BN to be tracked and then connected with the main reaction paths leading to the different BN coatings.

The new generation of the biologicalengineering materials for applications in medical and dental implant-scaffolds

Purpose: The publication aims to find the relationship between the proliferation of surface layers of living cells and the deposition of thin atomic layers deposition ALD coatings on the pores internal surfaces of porous skeletons of medical and dental implant-scaffolds manufactured with the selective laser deposition SLS additive technology using titanium and Ti6Al4V alloy. Design/methodology/approach: The extensive review of the literature presents the state-of-the-art in the field of regenerative medicine and tissue engineering. General ageing of societies, increasing the incidence of oncological diseases and some transport and sports accidents, and also the spread of tooth decay and tooth cavities in many regions of the world has taken place nowadays. Those reasons involve resection of many tissues and organs and the need to replace cavities, among others bones and teeth through implantation, more and more often hybridized with tissue engineering methods. Findings: The results of investigations of the structure and properties of skeleton microporous materials produced from titanium and Ti6Al4V alloy powders by the method of selective laser sintering have been presented. Particularly valuable are the original and previously unpublished results of structural research using high-resolution transmission electron microscope HRTEM. Particular attention has been paid to the issues of surface engineering, in particular, the application of flat TiO2 and Al2O3 coatings applied inside micropores using the atomic layers deposition ALD method and hydroxyapatite applied the dip-coating sol-gel method, including advanced HRTEM research. The most important part of the work concerns the research of nesting and proliferation of live cells of osteoblasts the hFOB 1.19 (Human ATCC - CRL - 11372) culture line on the surface of micropores with surfaces covered with the mentioned layers. Research limitations/implications: The investigations reported in the paper fully confirmed the idea of the hybrid technology of producing microporous implants and implant-scaffolds to achieve original Authors’ biological-engineering materials. The surface engineering issues, including both flat-layered nonorganic coatings and interactions of those coverings with flat layers of living cells, play a crucial role. Originality/value: Materials commonly used in implantology and the most commonly used materials processing technologies in those applications have been described. Against that background, the original Authors' concept of implant-scaffolds and the application of microporous skeleton materials for this purpose have been presented.

Jumping Droplets Push the Boundaries of Condensation Heat Transfer

Condensation heat transfer enhancement plays a critical role in more efficient power generation, improved electronics thermal management, and less energy-intensive natural gas processing, among other applications. In this issue of Joule, Ronggui Yang and colleagues demonstrated a method to promote jumping droplet condensation on a superhydrophobic surface at unprecedented levels of subcooling while also improving heat transfer performance by up to 100% compared to flat surface coatings. This finding paves the way for future implementation of this technology.

Abstract IA08: Analysis of a histiocytic carcinoma in the dog: The canine's utility in fetching disease genes

Abstract Histiocytic sarcoma (HS) is a rare human hematopoietic neoplasm that accounts for less than 1% of hematolymphoid cancers and occurs either concurrently with or subsequently to B- or T-lymphoblastic lymphoma and other B-cell cancers. As such, its genetic etiology has been difficult to establish. HS in dogs, by comparison, shows strong breed specificity with 20% of flat-coated retrievers and 25% of Bernese mountain dogs (BMD) estimated to develop the disease in their lifetime. These two affected breeds share no recent common ancestors and display differences in disease presentation, offering a unique system in which to investigate the genetic predisposition and progression of HS. Our lab has previously undertaken genome wide association study (GWAS) on both BMD and FCR collected in North America and Europe and identified four significantly associated loci, two in BMD and two in FCR. In each breed, only one locus was segregating with disease in the American population while both were present in the European populations. There were no loci in common between the two breeds. Fine mapping of the common BMD HS locus on canine chromosome (CFA) CFA11 revealed a single haplotype spanning the MTAP (methylthioadenosine phosphorylase) gene and part of the cyclin-dependent kinase inhibitor 2A (CDKN2A) gene, which was present in 96% of BMD with HS. The European BMD also showed a significant locus on CFA14 that may be approaching fixation in the American dogs based on allele frequency calculations. We have done targeted resequencing of the CFA14 locus in a subset of European BMD and are in the process of filtering the identified mutations. Promising candidate genes in this region include GRM8, which inhibits the cyclic AMP cascade in the central nervous system and has shown to be involved in several of cancers; POT1, which is involved in telomere length maintenance and protection; and HYAL4, a hyaluronidase potentially involved in extracellular matrix degradation. In addition, the laboratory has generated 30x sequence from two HS cases and a control BMD, two FCR cases, and a control and low pass sequence from 16 dogs (8 cases and controls) in order to identify the likely causative mutations in each of the associated loci as well as breed specific mutations that may predispose the dogs to aggressive cancers. Citation Format: Heidi G. Parker, Edouard Cadieu, Abigail Shearin, Gerard Rutteman, Elaine A. Ostrander. Analysis of a histiocytic carcinoma in the dog: The canine's utility in fetching disease genes [abstract]. In: Proceedings of the AACR Conference on Advances in Sarcomas: From Basic Science to Clinical Translation; May 16-19, 2017; Philadelphia, PA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(2_Suppl):Abstract nr IA08.

Morphological Distinction of Histiocytic Sarcoma from Other Tumor Types in Bernese Mountain Dogs and Flatcoated Retrievers.

Histiocytic sarcoma (HS) represents a group of malignant canine tumors to which Bernese Mountain Dogs (BMD) and Flatcoated Retrievers (FCR) are predisposed. The differential diagnosis for HS is broad, encompassing round cell tumors, sarcomas and other histiocytic diseases. The aim of this study was to establish morphological and immunohistochemical criteria for routine use on formalin-fixed, paraffin-embedded samples and cytological smears for the recognition and differentiation of canine HS and its subtypes. Retrospectively, tumor sections were reviewed from 449 BMD and 380 FCR with confirmed or suspected HS, other histiocytic conditions, or a disease of the differential diagnosis of HS. In a large proportion of cases, 47.5% for histology and for 46.3% cytology, the initial diagnosis was changed after the revision process. A large variation in morphological features of HS was observed in this study, making the existence of several subtypes in dogs also very likely. Furthermore, the different percentage of morphological features between BMD and FCR indicates the different mixture of cell type origins resulting possibly from genetic or environmental differences at the onset of HS in those breeds. This study stresses the value of a strictly applied and standardized scoring system for microscopic evaluation of tumor sections and smears, and the implementation of review and revision of pathological diagnoses.

Electrochemical deposition regimes and critical influence of organic additives on the structure of Bi films

The electrodeposition of Bi films from an acid perchlorate electrolyte was examined. The influence of various factors on the process of bismuth electrodeposition was investigated. It was determined that electrolyte mixing, temperature, organic additives exert a noticeable influence on the electrode process of the discharge of Bi3+ions in acid perchlorate electrolyte. X-ray diffraction patterns for all samples were indexed to rhombohedral Bi. Coatings with a signified texture (012) are formed in electrolyte without additives. This texture is retained by adding into the electrolyte the organic additives such as cresol, resorcinol, synthanol. With coloring agents (acridine yellow and safranin violet), the growth texture changes and the most intense reflex becomes (110). SEM investigations of coatings surface morphology showed that films electrodeposited without additives, as well as with safranin coloring agent, eventually form crystalline films with a block size of tens of microns, but with different texture growth. The additional presence of such organic additives as syntanol and resorcinol in the electrolyte guarantees flat, dense, close grained and uniform coatings with a thickness of 600 μm at room temperature and the highest cathode current density.

Prior joint disease is associated with increased risk of periarticular histiocytic sarcoma in dogs.

Periarticular histiocytic sarcoma (PAHS) is the most common synovial tumour in dogs and is characterized by aggressive local disease with a high rate of distant metastasis. Previously, an association between PAHS and prior joint disease has been demonstrated in the Bernese Mountain Dog breed and suggested in the Rottweiler. We hypothesized that this association would be present in other breeds and investigated this via a retrospective, case-controlled analysis. Cases were dogs diagnosed with PAHS of the stifle or elbow. Controls were age, breed and sex-matched dogs without a diagnosis of histiocytic sarcoma. Diagnosis of prior joint disease was determined based on review of medical records and direct veterinarian and owner communications. Data were evaluated using logistic regression, 2-sampled t tests, and chi-squared analysis. Our study population consisted of 28 cases and 46 controls, including Flat-Coated, Golden and Labrador Retrievers, Rottweilers, English Bulldogs, Shih Tzus, Australian Shepherds, Staffordshire Terriers and mixed breed dogs. Dogs with PAHS were more likely to have prior joint disease in the tumour-affected joint compared with the control population (odds ratio [OR] = 13.42, P < .0001, 95% confidence interval [CI] = 4.33-48.63). A total of 88.2% of dogs with stifle PAHS had prior joint disease in their tumour-affected joint, most commonly cranial cruciate ligament rupture. This study confirms that the previously noted association between prior joint disease and PAHS in Bernese Mountain Dogs also applies to other breeds. Additional studies are needed to further investigate for a causal relationship.

Electrodeposition of Iridium in 1-Butyl-3-Methylimidazolium Tetrafluoroborate Ionic Liquid

The electrochemical behaviors of iridium electrodeposited in 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid were studied. Cyclic voltammograms prepared on the gold electrode suggested that Ir(III) was reduced to iridium with an irreversible one-step process, which was controlled by the diffusion of Ir(III). The diffusion rate is 3.83×10 −11 m 2 /s and the average transfer coefficient is 0.083. The morphology of iridium coatings prepared on molybdenum substrates was observed by scanning electron microscopy (SEM), and the composition was characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Results show that the morphologies of iridium coatings is dependent on the potential, the time and the current density of electrodeposition. Compact coatings are obtained at the reduction peak potential with a balance between the nucleation rate and the growth rate. Flat and compact coatings are formed when the current density ranges from 0.5 mA/cm 2 to 1.82 mA/cm 2 in the galvanostatic electrodeposition.

Clinical conundrum

Alessandro Conte, a former intern at Willows Veterinary Centre invites Companion readers to consider a lame Flat-Coated Retriever

Confirmation that a deletion in the POMC gene is associated with body weight of Labrador Retriever dogs

A 14-bp deletion present in the proopiomelanocortin (POMC) gene of Labrador and Flat Coat Retrievers (FCR), but absent in POMC of other breeds, disrupts the β-MSH and β-endorphin coding sequences. This deletion was recently reported as strongly associated with increased body weight and obesity. We searched for this mutation in a cohort of 272 dogs, representing four breeds with a known predisposition to obesity (Labrador and Golden Retrievers, Beagle, and Cocker Spaniel) and, as expected, we found it only in Labradors. Further, we confirmed the association between the deletion variant and body weight of Labradors but not with a 5-point body condition score (BCS). We suspect that the deletion variant in our cohort may act as a recessive allele, unlike the previous study, which suggested its additive effect.

Identification of Complex Oxidation/Corrosion Behaviours of Boron Nitride Under High Temperature

To characterize the oxidation/corrosion behaviour of boron nitride (BN) at high temperature and to determine kinetics, thermo-gravimetric analyses were performed on BN flat coatings under dry (80% N2, 20% O2) and wet conditions (10% H2O, 70% N2, 20% O2), at temperatures ranging from 700 to 900 °C. The surface morphology was analysed by scanning electron microscopy. The aim of the study was to understand the complex behaviour of BN at high temperature under wet air. A model was then proposed to explain the recorded mass variations, by taking into account a competition between absorption and volatilization phenomena. Finally, an estimation of the amount of adsorbed species was extracted from these data.

Bioactive glass coatings fabricated by laser cladding on ceramic acetabular cups: a proof-of-concept study

Deposition of bioceramic coatings on medical implants is a valuable strategy to impart key added values, such as bioactivity. While flat coatings can be easily produced by enameling and similar techniques, applying a bioactive glass layer on surfaces with curved geometry is a great challenge from a technological viewpoint. In this work, for the first time we demonstrated the feasibility of bioactive glass coatings produced by laser cladding on alumina/zirconia ceramic acetabular cups for hip joint prosthesis. Laser-cladded glass coatings can be fabricated in a dense (pore-free) or porous form. Morphological analyses by scanning electron microscopy and micro-computed tomography revealed the good quality of joining at the coating/substrate interface and the good interconnectivity of the pores (size within 200–400 µm) in the outer porous layer. Indentation tests at the interface confirmed the excellent joining between glass and ceramic substrate. These coatings also exhibited a good bioactive behavior in vitro, as demonstrated by the formation of a surface apatite layer upon immersion studies in simulated body fluid.

T Lymphocytes in Histiocytic Sarcomas of Flat-Coated Retriever Dogs.

Flat-Coated Retriever dogs are predisposed to the development of histiocytic sarcoma (HS), a poorly differentiated, highly malignant neoplasm. The authors have previously documented a significant lymphocytic infiltrate in such tumors. The objective of this study was to examine the presence and expression of regulatory T cells in HS tumor samples. Forty tumors were included in this study. All tumors were immunolabeled for CD3, CD79a, CD25, CD45RA, and FOXP3. The proportion of positive cells was compared between tumors presenting as a localized primary soft tissue mass (soft tissue origin HS) and disseminated HS affecting viscera, especially the spleen (splenic origin HS). By immunohistochemistry, 95% of infiltrating T cells were positive for Foxp3 in all sections, suggesting the presence of regulatory T cells. The proportion of cells positive for FOXP3 was higher in the tumors arising in soft tissues, whereas the proportion of CD45RA-positive cells was higher in the splenic origin HS. Canine HS has an aggressive clinical behavior and is uniformly fatal. The difference in the proportion of tumor-infiltrating lymphocytes positive for these 2 markers in the 2 locations may represent differences in tumor microenvironment between the 2 sites.

Metabolizable energy intake of client-owned adult dogs.

A post hoc analysis of the metabolizable energy (ME) intake of privately owned pet dogs from the authors' nutrition consultation practice (Years 2007-2011) was carried out to identify if current ME recommendations are suitable for pet dogs. Data on 586 adult dogs were available (median age 5.5, median deviation from ideal weight 0.0), 55 of them were healthy; the others had various diseases. For ration calculation, a standardized questionnaire and the software diet-check Munich(™) was used. ME was predicted according to NRC (2006). Data were evaluated for the factors disease, breed, size, age, gender and type of feeding. The mean ME intake of all adult dogs amounted to 0.410±0.121 MJ/kg metabolic body weight (BW(0.75) ) (n=586). There was no effect of size and disease. Overweight dogs ate 0.360±0.121 MJ/kg BW(0.75) , and underweight dogs ate 0.494±0.159 MJ/kg BW(0.75) . Older dogs (>7years, n=149, 0.389±0.105 MJ/kg BW(0.75) ) had a lower ME intake than younger ones (n=313, 0.419±0.121 MJ/kg BW(0.75) ), and intact males had a higher ME intake than the others (p<0.001). Some breeds were above average: Jack Russell Terrier, Dalmatian, small Munsterlander and Magyar Viszla, Bearded Collies, Sight Hounds, German Boxers, English foxhounds, Rhodesian Ridgebacks and Flat-Coated Retrievers with a mean ME intake of 0.473±0.121 MJ/kg BW(0.75) . The following breeds were below average: Dachshunds, Bichons, West highland White Terrier, Collies except Bearded Collies, Airedale Terriers, American Staffordshire terriers and Golden Retrievers with a mean ME intake of 0.343±0.096 MJ/kg BW(0.75) . The mean maintenance energy requirements of pet dogs are similar to that of kennel dogs which do not exercise very much. These results suggest that opportunity and stimulus to exercise provided for pet dogs are lower than for kennel dogs. Lower activity in pet dogs may reduce part of potential effects of breed, medical history and age groups.