bluuebunny/crossref_metadata_2025_split huggingface dataset:
The stratum corneum: the rampart of the mammalian body
Authors: Nishifuji Koji , Yoon Ji Seon 
Published: January 2013

Background – The stratum corneum (SC) is the outermost region of the epidermis and plays key roles in cutaneous barrier function in mammals. The SC is composed of ‘bricks’, represented by flattened, protein‐enriched corneocytes, and ‘mortar’, represented by intercellular lipid‐enriched layers. As a result of this ‘bricks and mortar’ structure, the SC can be considered as a ‘rampart’ that encloses water and solutes essential for physiological homeostasis and that protects mammals from physical, chemical and biological assaults.Structures and functions – The corneocyte cytoskeleton contains tight bundles of keratin intermediate filaments aggregated with filaggrin monomers, which are subsequently degraded into natural moisturizing compounds by various proteases, including caspase 14. A cornified cell envelope is formed on the inner surface of the corneocyte plasma membrane by transglutaminase‐catalysed cross‐linking of involucrin and loricrin. Ceramides form a lipid envelope by covalently binding to the cornified cell envelope, and extracellular lamellar lipids play an important role in permeability barrier function. Corneodesmosomes are the main adhesive structures in the SC and are degraded by certain serine proteases, such as kallikreins, during desquamation.Clinical relevance – The roles of the different SC components, including the structural proteins in corneocytes, extracellular lipids and some proteins associated with lipid metabolism, have been investigated in genetically engineered mice and in naturally occurring hereditary skin diseases, such as ichthyosis, ichthyosis syndrome and atopic dermatitis in humans, cattle and dogs.
Evaluation of canine antimicrobial peptides in infected and noninfected chronic atopic skin
Authors: Santoro Domenico , Bunick David , Graves Thomas K. , Segre Mariangela 
Published: January 2013

Background –  Antimicrobial peptides (AMPs) are small immunomodulatory peptides produced by epithelial and immune cells. β‐Defensins (BDs) and cathelicidins (Caths) are the most studied AMPs. Recently, increased cutaneous expression of AMPs was reported in atopic humans and in beagles with experimentally induced atopy.Hypothesis/Objectives –  Our goal was to analyse mRNA expression and protein levels of canine (c)BD1‐like, cBD2‐like/122, cBD3‐like, cBD103 and cCath in healthy and naturally affected atopic dogs, with and without active skin infection, along with their distribution in the epidermis using indirect immunofluorescence.Animals –  Skin biopsies were taken from 14 healthy and 11 atopic privately owned dogs.Methods –  The mRNA levels of cBD1‐like, cBD2‐like/122, cBD3‐like, cBD103 and cCath were quantified using quantitative real‐time PCR. The protein levels of cBD3‐like and cCath were analysed by relative competitive inhibition enzyme‐linked immunosorbent assay, while the distributions of cBD2‐like/122, cBD3‐like and cCath were detected by indirect immunofluorescence.Results –  Dogs with atopic dermatitis had significantly greater mRNA expression of cBD103 (P = 0.04) than control dogs. Furthermore, atopic skin with active infection had a higher cBD103 mRNA expression (P = 0.01) and a lower cBD1‐like mRNA expression (P = 0.04) than atopic skin without infection. No significant differences in protein levels (cBD3‐like and cCath) or epidermal distribution of AMPs (cBD2‐like/122, cBD3‐like and cCath) were seen between healthy and atopic dogs.Conclusions and clinical importance –  Expression of cBD103 mRNA was greater, while expression of cBD1‐like mRNA was lower in dogs with atopic dermatitis that had active infections. Work is needed to clarify the biological mechanisms and possible therapeutic options to maintain a healthy canine skin.
The genomics revolution: will canine atopic dermatitis be predictable and preventable?
Authors: Nuttall Tim 
Published: January 2013

Background – Heritability studies suggest that atopic dermatitis (AD) involves multiple genes and interactions with environmental factors. Advances in genomics have given us powerful techniques to study the genetics of AD.Objective – To review the application of these techniques to canine AD.Results – Candidate genes can be studied using quantitative PCR and genomic techniques, but these are hypothesis‐dependent techniques and may miss novel genes. Hypothesis‐free techniques avoid this limitation. Microarrays quantify expression of large numbers of genes, although false‐positive associations are common. In the future, expression profiling could be used to produce a complete tissue transcriptome. Genome‐wide linkage studies can detect AD‐associated loci if enough affected dogs and unaffected relatives are recruited. Genome‐wide association studies can be used to discover AD‐associated single nucleotide polymorphisms without relying on related dogs. Genomic studies in dogs have implicated numerous genes in the pathogenesis of AD, including those involved in innate and adaptive immunity, inflammation, cell cycle, apoptosis, skin barrier formation and transcription regulation. These findings, however, have been inconsistent, and problems include low case numbers, inappropriate controls, inconsistent diagnosis, incomplete genome coverage, low‐penetrance mutations and environmental factors.Conclusions – Canine AD has a complex genotype that varies between breeds and gene pools. Breeding programmes to eliminate AD are therefore unlikely to succeed, but this complexity could explain variations in clinical phenotype and response to treatment. Genotyping of affected dogs will identify novel target molecules and enable better targeting of treatment and management options. However, we must avoid misuse of genomic data.
Expression of thymic stromal lymphopoietin in canine atopic dermatitis
Authors: Klukowska‐Rötzler Jolanta , Chervet Ludovic , Müller Eliane J. , Roosje Petra , Marti Eliane , Janda Jozef 
Published: January 2013

Background –  In humans, thymic stromal lymphopoietin (TSLP) plays a central role in the development of allergic inflammation, such as atopic dermatitis (AD), but it is unknown whether it is involved in the pathogenesis of canine AD (CAD).Hypothesis/Objectives –  Our aim was to characterize canine TSLP and to assess its expression in CAD.Methods –  Canine TSLP was identified based on sequence homology with human TSLP and the complementary DNA (cDNA) cloned by RT‐PCR. Real‐time quantitative RT‐PCR was established to assess the expression of canine TSLP in cultured canine keratinocytes and in skin biopsy specimens from lesional and nonlesional skin of 12 dogs with CAD and eight healthy control dogs.Results –  Partial canine TSLP cDNA was cloned and characterized. It contained four exons that shared 70 and 73% nucleotide identity with human and equine TSLP, respectively, encoding the signal peptide and full‐length secreted protein. We found significantly increased TSLP expression in lesional and nonlesional skin of dogs with CAD compared with healthy control dogs (P < 0.05), whereas no difference was measured between lesional and nonlesional samples. In cultured primary canine keratinocytes, we found increased TSLP expression after stimulation with house dust mite allergen extract or Toll‐like receptor ligands lipopolysaccharide and poly I:C.Conclusions and clinical importance –  Increased TSLP expression in the skin of dogs with CAD supports an involvement of TSLP in the pathogenesis of CAD similar to that in humans. Further studies should elucidate the function and therapeutic potential of TSLP in CAD.
Epidermal structure created by canine hair follicle keratinocytes enriched with bulge cells in a three‐dimensional skin equivalent model in vitro: implications for regenerative therapy of canine epidermis
Authors: Kobayashi Tetsuro , Enomoto Kaoru , Wang Yu Hsuan , Yoon Ji Seon , Okamura Ryoko , Ide Kaori , Ohyama Manabu , Nishiyama Toshio , Iwasaki Toshiroh , Nishifuji Koji 
Published: January 2013

Background –  Keratinocytes in the hair follicle bulge region have a high proliferative capacity, with characteristics of epithelial stem cells. This cell population might thus be an ideal source for generating the interfollicular epidermis in a canine skin equivalent.Hypothesis/Objectives –  This study was designed to determine the ability of canine hair follicle bulge cell‐enriched keratinocytes to construct canine living skin equivalents with interfollicular epidermis in vitro.Animals –  Four healthy beagle dogs from a research colony.Methods –  Bulge cell‐enriched keratinocytes showing keratin 15 immunoreactivity were isolated from canine hair follicles and cultured on dermal equivalent containing canine fibroblasts. Skin equivalents were subjected to histological, immunohistochemical, western blot and RT‐PCR analyses after 10–14 days of culture at the air–liquid interface.Results –  The keratinocyte sheets showed an interfollicular epidermal structure comprising four to five living cell layers covered with a horny layer. Immunoreactivities for keratin 14 and desmoglein 3 were detected in the basal and immediate suprabasilar layers of the epidermis, while keratin 10 and desmoglein 1 occurred in more superficial layers. Claudin 1 immunoreactivity was seen in the suprabasalar layer of the constructed epidermis, and filaggrin monomers and loricrin were detected in the uppermost layer. Basal keratinocytes in the skin equivalent demonstrated immunoreactivity to antibodies against basement membrane zone molecules.Conclusions and clinical importance –  A bulge stem cell‐enriched population from canine hair follicles formed interfollicular epidermis within 2 weeks in vitro, and thus represents a promising model for regenerative therapy of canine skin.
Interleukin‐31: its role in canine pruritus and naturally occurring canine atopic dermatitis
Authors: Gonzales Andrea J. , Humphrey William R. , Messamore James E. , Fleck Timothy J. , Fici Gregory J. , Shelly John A. , Teel Janet F. , Bammert Gary F. , Dunham Steven A. , Fuller Troy E. , McCall Robert B. 
Published: January 2013

Background –  Interleukin‐31 (IL‐31) is a member of the gp130/interleukin‐6 cytokine family that is produced by cell types such as T helper 2 lymphocytes and cutaneous lymphocyte antigen positive skin homing T cells. When overexpressed in transgenic mice, IL‐31 induces severe pruritus, alopecia and skin lesions. In humans, IL‐31 serum levels correlate with the severity of atopic dermatitis in adults and children.Hypothesis/Objective –  To determine the role of IL‐31 in canine pruritus and naturally occurring canine atopic dermatitis (AD).Animals –  Purpose‐bred beagle dogs were used for laboratory studies. Serum samples were obtained from laboratory animals, nondiseased client‐owned dogs and client‐owned dogs diagnosed with naturally occurring AD.Methods –  Purpose‐bred beagle dogs were administered canine interleukin‐31 (cIL‐31) via several routes (intravenous, subcutaneous or intradermal), and pruritic behaviour was observed/quantified via video monitoring. Quantitative immunoassay techniques were employed to measure serum levels of cIL‐31 in dogs.Results –  Injection of cIL‐31 into laboratory beagle dogs caused transient episodes of pruritic behaviour regardless of the route of administration. When evaluated over a 2 h period, dogs receiving cIL‐31 exhibited a significant increase in pruritic behaviour compared with dogs that received placebo. In addition, cIL‐31 levels were detectable in 57% of dogs with naturally occurring AD (≥13 pg/mL) but were below limits of quantification (<13 pg/mL) in normal, nondiseased laboratory or client‐owned animals.Conclusions –  Canine IL‐31 induced pruritic behaviours in dogs. Canine IL‐31 was detected in the majority of dogs with naturally occurring AD, suggesting that this cytokine may play an important role in pruritic allergic skin conditions, such as atopic dermatitis, in this species.
Small Demodex populations colonize most parts of the skin of healthy dogs
Authors: Ravera Iván , Altet Laura , Francino Olga , Sánchez Armand , Roldán Wendy , Villanueva Sergio , Bardagí Mar , Ferrer Lluís 
Published: January 2013

Background – It is unproven that all dogs harbour Demodex mites in their skin. In fact, several microscopic studies have failed to demonstrate mites in healthy dogs.Hypothesis/Objectives – Demodex canis is a normal inhabitant of the skin of most, if not all, dogs. This hypothesis was tested using a sensitive real‐time PCR to detect Demodex DNA in the skin of dogs.Animals – One hundred dogs living in a humane society shelter, 20 privately owned and healthy dogs and eight dogs receiving immunosuppressive or antineoplastic therapy.Methods – Hair samples (250–300 hairs with their hair bulbs) were taken from five or 20 skin locations. A real‐time PCR that amplifies a 166 bp sequence of the D. canis chitin synthase gene was used.Results – The percentage of positive dogs increased with the number of sampling points. When a large canine population was sampled at five cutaneous locations, 18% of dogs were positive for Demodex DNA. When 20 skin locations were sampled, all dogs tested positive for mite DNA. Our study indicates that Demodex colonization of the skin is present in all dogs, independent of age, sex, breed or coat. Nevertheless, the population of mites in a healthy dog appears to be small. Demodex DNA was amplified from all 20 cutaneous points investigated, without statistically significant differences.Conclusions and clinical importance – Using a real‐time PCR technique, Demodex mites, albeit in very low numbers, were found to be normal inhabitants of haired areas of the skin of healthy dogs.
Usefulness of cefovecin disk‐diffusion test for predicting mecA gene‐containing strains of Staphylococcus pseudintermedius and clinical efficacy of cefovecin in dogs with superficial pyoderma
Authors: Iyori Keita , Toyoda Yoichi , Ide Kaori , Iwasaki Toshiroh , Nishifuji Koji 
Published: January 2013

Background – Cefovecin has been widely used to treat skin infections in dogs. The relationship of the cefovecin disk‐diffusion test results to the presence of the mecA gene and the clinical efficacy of cefovecin have not been fully evaluated.Hypothesis/Objectives – To determine the usefulness of an in vitro cefovecin disk‐diffusion test in predicting the presence of the mecA gene in Staphylococcus pseudintermedius, as well as the in vivo efficacy of cefovecin therapy in dogs with superficial pyoderma.Methods – Twenty‐six S. pseudintermedius strains isolated from 22 dogs with pyoderma were used. In vitro disk‐diffusion test results of cefovecin were compared with agar‐dilution test results, the presence of the mecA gene, and the improvement in clinical scores of dogs with superficial pyoderma at 14 days post treatment.Results – There was a significant linear correlation (r = −0.83) between the diameter of the obvious zone of inhibition by disk diffusion and the minimal inhibitory concentration for cefovecin (P < 0.0001). Receiver operating characteristic analysis revealed that zone diameters between 25 and 27 mm exhibited better sensitivity (92.9%) and specificity (100.0%) for detection of strains carrying the mecA gene. The mean improvement in clinical scores in dogs carrying cefovecin‐resistant strains was significantly lower than in dogs carrying cefovecin‐susceptible strains (P < 0.01).Conclusions and clinical importance – The cefovecin disk‐diffusion test with a cut‐off value estimated in this study was valuable for predicting mecA gene carriage in S. pseudintermedius, as well as the in vivo efficacy of cefovecin therapy in dogs with superficial pyoderma caused by S. pseudintermedius.
The contribution of stem cells to epidermal and hair follicle tumours in the dog
Authors: Brachelente Chiara , Porcellato Ilaria , Sforna Monica , Lepri Elvio , Mechelli Luca , Bongiovanni Laura 
Published: January 2013

Background – Although cutaneous stem cells have been implicated in skin tumourigenesis in humans, no studies have been conducted to elucidate the presence and the possible role of stem cells in hair follicle tumours in the dog.Hypothesis – Stem cell markers are expressed in canine epidermal and follicular tumours and can be used to better understand the biology and origin of these tumours.Animals and Methods – In the present study, normal skin sections and 44 follicular tumours were retrospectively investigated for the immunohistochemical expression of keratin 15 (K15) and nestin. In addition, 30 squamous cell carcinomas were evaluated for K15 expression.Results – In normal skin, K15 and nestin were expressed in the outer root sheath cells of the isthmic portion of the hair follicle (bulge region), and K15 expression was also scattered in the basal cell layer of the epidermis. Infundibular keratinizing acanthomas, pilomatricomas and squamous cell carcinomas were mostly negative for K15, trichoblastomas were moderately to strongly positive, tricholemmomas were either negative or strongly positive, and trichoepitheliomas had heterogeneous staining. Nestin expression was generally faint in all follicular tumours.Conclusions and clinical importance – Our results show that K15 can be a reliable marker for investigating the role of stem cells in hair follicle tumours of the dog, while nestin was judged to be a nonoptimal marker. Furthermore, our study suggests that hair follicle stem cells are present in the bulge region of hair follicles and could possibly play a role in tumourigenesis of canine tumours originating from this portion of the follicle, namely trichoblastomas, tricholemmomas and trichoepitheliomas. The loss of K15 expression in squamous cell carcinomas compared with normal skin suggests that this event could be important in the malignant transformation.
Skin lipid profiling in normal and seborrhoeic shih tzu dogs
Authors: Yoon Ji‐Seon , Nishifuji Koji , Ishioroshi Sinpei , Ide Kaori , Iwasaki Toshiroh 
Published: January 2013

Background –  Seborrhoea is a clinical condition resulting in excessive lipid and/or scale on the skin and is a common and important skin disease of dogs. However, there is little information on the skin surface lipid composition of dogs with seborrhoea.Hypothesis/Objectives –  To compare skin surface lipid profiles in normal and seborrhoeic shih tzu dogs.Methods –  Fourteen client‐owned dogs (seven seborrhoeic and seven normal) were investigated. Lipids in sebaceous glands (SGs) were extracted from homogenized tissues of SG hyperplasia. Surface lipid was collected by tape stripping [stratum corneum (SC)‐enriched fraction] and acetone‐wetted cotton swab (acetone‐extracted fraction). Lipids in SGs, SC‐enriched fractions and acetone‐extracted fractions were evaluated by high‐performance thin‐layer chromatography.Results –  Lipids in SGs mainly consisted of cholesterol esters, wax esters and triglycerides, whereas lipids in the SC‐enriched fraction mainly consisted of ceramides. The acetone‐extracted fraction contained a mixture of lipid classes recognized in SG‐ and SC‐enriched fractions. In seborrhoeic dogs, concentrations of wax esters and triglycerides in the acetone‐extracted fraction were significantly higher than in control dogs (P = 0.0285). Amounts of total ceramides (in micrograms) per milligram of SC were not significantly different between the two groups (P = 0.5204). Interestingly, two unknown ceramide fractions, which accounted for 20% of the total ceramides, were recognized exclusively in seborrhoeic dogs.Conclusions and clinical importance –  These results provide evidence that the skin surface lipid profiles are altered in shih tzu dogs with seborrhoea.
In vitro antiseptic susceptibilities for Staphylococcus pseudintermedius isolated from canine superficial pyoderma in Japan
Authors: Murayama Nobuo , Nagata Masahiko , Terada Yuri , Okuaki Mio , Takemura Noriyuki , Nakaminami Hidemasa , Noguchi Norihisa 
Published: January 2013

Background – Topical therapy, particularly with chlorhexidine, is becoming increasingly common as a treatment option for canine pyoderma; however, there are limited studies on the susceptibility of Staphylococcus pseudintermedius to chlorhexidine compounds.Objectives – To determine the in vitro susceptibility of both meticillin‐resistant and meticillin‐susceptible S. pseudintermedius isolates to chlorhexidine and other antiseptic agents and the presence of multidrug efflux pump genes.Samples – One hundred S. pseudintermedius isolates from 23 initial and 77 recurrent cases of canine pyoderma.Methods – After bacterial identification and mecA testing, minimal inhibitory concentrations (MICs) of antiseptic agents were determined. Multidrug efflux pump genes, including qacA, qacB and smr, were identified.Results – Of the 100 isolates, 57 were identified as meticillin‐resistant S. pseudintermedius. The MIC90 of chlorhexidine acetate, chlorhexidine gluconate, acriflavine, ethidium bromide and benzalkonium chloride were 1, 1, 2, 0.5 and 2 μg/mL, respectively. Multidrug efflux pump genes qacA, qacB and smr were not detected in any of the isolates.Conclusions and clinical importance – The MICs for chlorhexidine and other antiseptics remain low, and multidrug efflux pump genes were not found in the tested isolates.
Ulcerated and nonulcerated nontuberculous cutaneous mycobacterial granulomas in cats and dogs
Authors: Malik Richard , Smits Bronwyn , Reppas George , Laprie Caroline , O’Brien Carolyn , Fyfe Janet 
Published: January 2013

Background – Mycobacterial granulomas of the skin and subcutis can be caused by one of a number of pathogens. This review concentrates on noncultivable species that cause diseases characterized by focal granuloma(s), namely leproid granuloma (in dogs) and feline leprosy (in cats). Clinically indistinguishable lesions can be caused by tuberculous organisms (Mycobacterium bovis and Mycobacterium microti) and members of the Mycobacterium avium complex. Rapidly growing mycobacterial species that cause infection of the subcutaneous panniculus associated with draining tracts are not discussed. Disease caused by Mycobacterium ulcerans is an important emerging differential diagnosis for ulcerated cutaneous nodules in certain localized regions.Clinical lesions – Lesions comprise one or multiple nodules in the skin/subcutis. These are generally firm and well circumscribed, and typically become denuded of hair. They may or may not ulcerate, depending on the virulence of the causal organisms and the immune response of the host.Diagnosis – The most inexpensive, noninvasive means of diagnosis is by submission of methanol‐fixed, Romanowsky‐stained smears to a Mycobacterium Reference Laboratory after detecting negatively stained or acid‐fast bacilli on cytological smears. Scrapings of material from slides usually provide sufficient mycobacterial DNA to enable identification of the causal organism using sequence analysis of amplicons after PCR using specific mycobacterial primers.Therapy – Therapy relies upon a combination of marginal resection of easily accessible lesions and treatment using two or three drugs effective against slowly growing mycobacteria, choosing amongst rifampicin, clarithromycin, clofazimine and pradofloxacin/moxifloxacin.