Mast cell distribution,epidermal thickness and hair follicle density in normal canine skin: possible explanations for the predilection sites of atopic dermatitis?

Mast cell counts, epidermal thickness and hair follicle density were quantified in toluidine blue stained sections of normal skin from 20 different body regions in 10 dogs and compared to the predilection sites of canine atopic dermatitis. Mast cell distribution varied significantly from site to site (P < 0.0001) and counts in the superficial dermis were significantly higher than the deeper dermis (P < 0.05). Mast cell counts were highest in the medial and lateral pinna (mean 10.4–11.3 per high power field, HPF) and in the ventral interdigital skin of the hind and fore feet (mean 9.2–9.5 per HPF). Counts in these regions were at least 150% higher than all the other sites (means ranging between 2.9 and 6.0 per HPF). Variations in mast cell counts, epidermal thickness or hair follicle density did not adequately explain the predilection sites of canine atopic dermatitis. However, the results provide some evidence that cutaneous mast cell distribution may be involved in the frequent occurrence of ear and foot pruritus in this disease.     

剑白香猪各组织中肥大细胞的观察研究

目的：试验旨在通过对6月龄剑白香猪肥大细胞的观察,以期了解肥大细胞在剑白香猪不同组织器官的数量、分布及形态。方法：采集剑白香猪心、肝、脾、肺、肾、肾上腺、小肠等部位样品用多聚甲醛和carnoy’s液固定后,用甲苯胺蓝染色法检测各组织中肥大细胞数量、分布及形态,并用SPSS13．0软件进行统计分析。结果：试验表明,肥大细胞数量在不同性别问无明显差异;Carnoy’S固定液是测定猪各组织器官MC的较理想固定液;肥大细胞在各种组织中分布及形态复杂多样。本试验可为剑白香猪肥大细胞的进一步研究提供参考数据。     

Globule leukocyte and mast cell in bile ducts of cattle naturally infected with liver flukes

In n previous report dealing with the pathology of bovine fascio-liasis the author described an unknown cell type in the epithelium of bile ducts. The histological and histochemical investigations published in this paper suggest that the cell may be considered a globule leukocyte. Globule leukocytes are rare in uninfected livers but are occurring in abundance in main bile ducts of cattle with spontaneous fascioliasis and also in small perilobular ducts in dicrocoeliasis. Liver fluke infection causes an increase in the population of subepithelial mast cells. Mast cell and globule leukocyte present similarities In their cytochemical properties. However, at low pH toluldinc blue shows a stronger but Alcian blue a weaker affinity for mast cells than for globule leukocytes.     

Mast cell tumour and cutaneous histiocytoma excision wound healing in general practice

Objective : To assess whether wounds from incomplete mast cell tumour excisions are at greater risk of healing complications than wounds from complete excisions, or cutaneous histiocytomas. Methods : Mast cell tumours and cutaneous histiocytomas submitted to Nationwide Laboratories between November 1, 2007 and April 30, 2008 were selected. Questionnaires were sent to submitting veterinarians requesting details of tumour characteristics, clinical approach to the tumour and wound healing. Results : Three hundred and eighty‐six mast cell tumours and 524 cutaneous histiocytomas were identified. One hundred and eighty‐five mast cell tumours and 244 cutaneous histiocytomas questionnaires were returned (47% response). Wound complications arose in 20% of mast cell tumours and 21% of cutaneous histiocytomas. Multivariable analysis confirmed that larger tumours, tumours on the feet and a soft/“baggy” appearance, were significantly associated with a greater frequency of problems, leading to delayed wound healing and dehiscence. Clinical Significance : Incomplete mast cell tumour excision does not lead to greater risk of wound complications. Mast cell tumour surgical wounds have a similar rate of wound complications as cutaneous histiocytoma wounds.     

On the Ultrastructure of Mast Cells and Globule Leucocytes in the Common Bile Duct of Cattle Chronically Infected With Fasciola Hepatica

Mast cells and globule leucocytes in the walls of the common bile ducts of seven uninfected slaughtered cows and of five cows chronically infected with Fasciola hepatica were studied by electron microscopy. The mast cells displayed numerous small intracytoplasmic granules, the matrixes of which were either strongly electron-opaque and homogeneous or less dense with a fine-granular ultrastructure. Unattached ribosomes were abundant in the cytoplasm of the cells. Many mast cells in the walls of chronically infected bile ducts were normal-looking while the cells in the subepithelial tissues often showed striking irregularities in the ultrastructure of the granules. Globule leucocytes were most numerous in the surface epithelium and were not connected by desmosomes to the epithelial cells. The nuclei of the globule leucocytes were similar to those in the mast cells except that indentations caused by the globules were more usually seen. The globules were considerably larger than the mast cell granules but bounded by similar agranular capsules. The matrix of most globules was dense and homogeneous while the other globules showed dense reticulate or lamellate structures. The relationship between the mast cell and globule leucocyte in the liver is briefly discussed with reference to recent reports on these cells in the intestinal wall.     

Assessment of proliferative activity of canine dermal mast cells by bromodeoxyuridine and proliferating cell nuclear antigen labelling

Cutaneous mast cells from skin biopsies of three healthy dogs and three dogs with atopic dermatitis were assessed for their proliferative potential using bromodeoxyuridine and proliferating cell nuclear antigen labelling. Mast cells isolated from the skin of two healthy dogs were also studied using bromodeoxyuridine labelling. Mast cells in skin biopsy specimens and mast cells isolated from the skin of healthy dogs did not incorporate bromodeoxyuridine. Two mast cells expressing proliferating cell nuclear antigen were seen around two superficial vessels in the dermis of one atopic dog. Epidermal cells, glandular epithelial cells, fibroblasts and endothelial cells incorporated bromodeoxyuridine and showed positive staining for proliferating cell nuclear antigen. These results suggest that canine mature mast cells do not proliferate in the dermis.     

Canine Transmissible Venereal Tumour: Asessment of Mast Cell Numbers as Indicators of the Growth Phase

Mast cells are immune cells that are involved mainly in type 1 hypersensitivity reactions, and they have been implicated in tumour angiogenesis. In this study we assessed the presence of mast cell numbers and microvessel density during the progression and regression stages of natural spontaneous canine transmissible venereal tumours (CTVT). Mast cells were demonstrated by histochemical staining with toluidine blue, alcian blue and safranin O. Microvessel counts were demonstrated by immunohistochemical labelling with an antibody against the endothelial cell marker factor VIII. Mitotic cells, apoptotic cells and tumour infiltrating lymphocytes were counted from haematoxylin–eosin-stained sections. Tumour fibrosis was evaluated on Masson's trichome-stained sections. The results showed that progressing tumours had significantly higher mast cell counts and microvessel counts at the invasive edges of the tumours than did regressing tumours. In both the progressing and regressing tumours, microvessel counts were significantly positively correlated with mast cell counts. Regressing tumours had significantly higher mast cell counts of the whole tumour than progressing tumours. The results also showed that progressing tumours had significantly higher mitotic rate than regressing tumours, and fibrosis and apoptosis were significantly higher in regressing tumours than progressing tumours. There were no significant differences between the biochemical and haematological values of dogs with progressing and regressing tumours. These results suggests that mast cells play a role in CTVT progression probably by promoting vascularization at the invasion front during the progression phase, and that mast cell count could be used as one of the histological factors to indicate growth stage of CTVT.     

The distribution and heterogeneity of mast cells in tongue from five different avian species

This study was conducted with the aim of determining the morphology, distribution and heterogeneity of mast cells in the tongues of seagull (Larus fuscus), common buzzard (Buteo buteo), goose (Anser anser), white stork (Ciconia ciconia) and Gerze rooster. The study used five samples of tongue material from each of the healthy adult avian species. The samples were fixed in 10% neutral‐buffered formalin (NBF) solution, then, after routine tissue follow‐up, the samples blocked with paraplast. Cross‐sections with 5–6 μm of thickness were stained with the 0.5% toluidine blue and alcian blue/safranin O (AB/SO). In all five avian species, it was found that the mast cells were in different sizes and round, oval or spindle‐shaped based on their place of distribution. Mast cell numbers were determined in stained with toluidine blue, examined ×40 objectives in a 1 mm² area. It was observed that mast cell density in subepithelial lamina propria and microscopic papilla was higher in the tongues of all species. Mast cell distribution and heterogeneity varied through the tongue, and there were more mast cells in the dorsal side of the tongue than the ventral side. The highest amount of mast cells was found in the tongue of the Gerze rooster among all five species. In the tongue cross‐sections stained with the combined method of alcian blue/safranin O (AB/SO), the mast cells were stained as AB (+), SO (+) and AB/SO (+) (mixed).     

Lesions of the enteric nervous system and the possible role of mast cells in the pathogenic mechanisms of migration of schistosome eggs in the small intestine of cattle during Schistosoma bovis infection

The enteric nervous system in the small intestine of cattle during Schistosoma bovis infection was studied by histological stains and immunohistochemical methods. Lesions due to migration of schistosoma eggs were located mainly in the mucous and the submucous layer overlaying the submucous vascular arcades. Granulomas destroyed ganglia, neurons, nerves fibre strands and nerve fibres. Ganglia situated within or near granulomas were infiltrated by mast cells, eosinophils, lymphocytes, globule leukocytes, neutrophils and macrophages. Mast cells were in close contact with degenerating neuronal perikarya. Whereas vasoactive intestinal peptide-like immunoreactivity in the nerves and neurons in the ganglia within and around granulomas was increased, the neurofilament-like immunoreactivity was reduced. Compared to the myenteric and external submucous plexuses, the internal submucous and mucous plexuses were the most damaged. These changes imply reduced functional capacity in the nervous tissue which might cause reduced motility, malabsorption and partly account for the loss of body weight and condition and failure to thrive which occur in schistosomosis.Biotinylated affinity purified swine anti-rabbit and mouse anti-rabbit immunoglobulins reacted nonspecifically with a subset of mast cells. The reaction revealed many mast cells in early forming granulomas and around schistosome egg tracts and infiltration of mast cells into the ganglia of intestinal nerve plexuses. The observation shows a localized, Type I hypersensitivity reaction suggesting for the release of mast cell-derived chemical mediators in the intestinal reaction to trap or evict S. bovis eggs and to cause diarrhoea.     

Footrot and interdigital dermatitis in sheep: farmers' practices, opinions and attitudes

In 1999, a study was initiated to improve the treatment and control of footrot and interdigital dermatitis in sheep flocks in England and Wales. In November 2000, a retrospective cross-sectional study was conducted in which 392 sheep farmers were asked to estimate the prevalence of footrot and interdigital dermatitis in their flock in the previous 12 months, whether they considered these diseases to be a problem, how they treated and controlled them and their opinion on the success of the treatment and control measures that they used; 209 of them provided usable responses. The farmers tended to be more concerned as the prevalence of the diseases increased; 91 per cent of the farmers with a prevalence of footrot of less than 5 per cent considered it a small or very small problem on their farm, but 51 per cent of the farmers with a prevalence of 5 per cent or more also considered it to be a small or very small problem. Approximately 60 per cent of the farmers who used parenteral antibiotics considered that they were good or excellent at treating footrot, and this treatment was associated with a prevalence of less than 5 per cent. A similar proportion of farmers also considered topical foot sprays and footbathing to be good or excellent for controlling footrot or interdigital dermatitis, but these treatments were not associated with a lower prevalence of footrot or interdigital dermatitis. Of the 29 farmers who used a footrot vaccine, 20 (69 per cent) considered it good to excellent and this was associated with a prevalence of footrot of less than 5 per cent in their flock; however, vaccination was not associated with lower levels of footrot across the whole sample. Farmers spent approximately 34 minutes per sheep per year treating and controlling footrot; 31 per cent were prepared to spend more money and more time to manage footrot, 27 per cent were prepared to spend more time, 19 per cent were prepared to spend more money and 23 per cent were not prepared to do either. The farmers who were willing to invest more money or more money and time had a higher prevalence of footrot.     

小鼠胃、小肠和精囊黏膜肥大细胞的组织学观察

取健康小鼠胃、肠管和精囊放入生理盐水中冲洗干净,放入10%中性甲醛固定液中固定、透明、浸蜡、包埋,对胃、肠管和精囊进行连续切片,并用苏木精-伊红和甲苯胺蓝染色。然后,用光学显微镜观察小鼠胃、肠管和精囊的肥大细胞并计数,再用生物统计学方法分析、比较了胃、肠管和精囊肥大细胞的分布规律。结果发现,胃内的肥大细胞最多,小肠较少,而精囊中几乎看不到。胃和小肠内肥大细胞主要分布在血管和腺管周围。     

Mast cells in the ovary of Gallus gallus domesticus

1. Histamine or mast cells are involved in mammalian ovary function. Their role in the avian ovary is not known. In the present study mast cell distribution in the ovary of the domestic fowl was studied. 2. Mast cells were distributed throughout the ovary, both in the stroma of medullary and cortical regions as well as in the thecae of normal and atretic follicles. In the stroma, mast cells were especially abundant in the area just below the germinal epithelium (GE) and followed the contours of the GE. 3. In the follicles, mast cells were more obvious in the thecae of small non-yolky follicles, whereas they were compressed and scattered in the larger yolky follicles. They were more frequently seen in the theca externa than in the theca interna and in their ultrastructure showed characteristic mast cell granules. 4. Some of the atretic follicles showed increased mast cells in their thecae. Postovulatory follicles had very few mast cells. 5. The possible role of the mast cells in the ovarian activity of domestic fowl is discussed.     

Soft tissue sarcomas and mast cell tumours in dogs; clinical behaviour and response to surgery

OBJECTIVE: To characterise the types of canine soft tissue sarcoma and mast cell tumour treated surgically at the University Veterinary Centre, Sydney. To evaluate the success of surgical treatment of these tumours and identify variables predictive of local recurrence and survival. To establish whether conclusions drawn from previous international studies are applicable to the University Veterinary Centre, Sydney, dog population and vice versa. DESIGN: Clinical presentation and results of surgical excision of 54 soft tissue sarcomas and 70 mast cell tumours affecting the trunk and limbs of dogs at the University Veterinary Centre, Sydney, between 1989 and 2001 were reviewed retrospectively. RESULTS: Cross-bred dogs and Rhodesian Ridgebacks were at significantly greater risk of developing soft tissue sarcomas, and Boxers, Australian Cattle Dogs and Staffordshire Bull Terriers were at significantly greater risk of developing mast cell tumours than other breeds. Fine needle aspiration biopsy yielded a correct diagnosis in 62.5% of soft tissue sarcomas and 96% of mast cell tumours. Local recurrence was encountered after surgical excision in 7.4% of soft tissue sarcomas and 7.3% of mast cell tumours. Metastasis occurred in 6% of soft tissue sarcomas and 12% of mast cell tumours. The most significant risk factors for local recurrence were contaminated surgical margins (soft tissue sarcomas) and histological grade (mast cell tumours). Due to the low number of animals experiencing metastasis, no conclusions could be drawn about significant risk factors. CONCLUSIONS: Aggressive surgical management of soft tissue sarcomas and mast cell tumours is associated with a low incidence of local recurrence. The type, location and behaviour of mast cell tumours and soft tissue sarcomas in the population of dogs presented to the University Veterinary Centre, Sydney are similar to those reported by others.     

Relationships between the histological grade of cutaneous mast cell tumours in dogs, their survival and the efficacy of surgical resection

The histological grade of 340 cutaneous mast cell tumours derived from 280 dogs was determined by an established histological grading system; 87 of the tumours (26 per cent) were well differentiated, 199 (59 per cent) were intermediately differentiated and 54 (16 per cent) were poorly differentiated. The one-year survival rates for the dogs with tumours of these three grades were significantly different (P = 0.0001), being 100 per cent, 92 per cent and 46 per cent, respectively. The median survival time for the dogs with poorly differentiated tumours was 278 days, significantly shorter than that for the dogs with either intermediately or well-differentiated tumours, which were both over 1300 days. Regrowth of the tumours was identified in 10 (19 per cent) of the dogs with poorly differentiated tumours, 12 (6 per cent) of the dogs with intermediately differentiated tumours and one of the dogs with well-differentiated tumours; only three of the tumours which regrew had initially had complete margins. The results suggest that wide surgical margins are not a prerequisite for a successful long-term outcome in dogs with well-differentiated cutaneous mast cell tumours.     

Multinodular Malignant Cutaneous Mast Cell Tumor in a Horse With Generalized Pruritus and Reactive Fibrosis: A Case Report

Mast cell tumor (MCT) has long been considered as an uncommon neoplasm in horses. Cytological and behavioral evidence of its malignancy is usually lacking, and only a few reports have described MCT displaying malignant behavior. An 18-year-old Friesian stallion presented with a one-year history of intermittent and progressive skin lesions on the left forelimb associated with intense, generalized pruritus and apathy temporarily responsive to glucocorticoids and antibiotics. The horse was alert and responsive with poor body condition and marked generalized pruritus. The left forelimb was markedly enlarged and surrounded by numerous firm 2- to 20-cm masses that were ulcerated and focally necrotic. A 7-cm round firm mass was observed on the left dorsal neck. Dermatological examination revealed generalized moth-eaten alopecia and scaling with erosions and ulcers secondary to pruritus. A direct skin smear from the affected leg showed severe eosinophilic inflammation and neutrophilic inflammation with pleomorphic bacteria. Histopathology of the skin and biopsies of the underlying tissues revealed an abundant population of atypical mast cells consistent with a malignant MCT. The horse was euthanized and necropsy revealed a marked fibrous reaction on longitudinal sections of the affected limb, and the tumor could be detected on only a few histological slides. Diagnosis of equine MCT can be challenging because of the massive accompanying fibrous reaction. Mast cell tumor should be suspected in the presence of eosinophilic infiltration of the affected tissue and in cases of generalized pruritus not attributable to other causes.     

Morphological and immunocytochemical investigations on mast cells in porcine ureter

Morphological, morphometric, histochemical and immunocytochemical investigations on mast cells, located in the wall of ureter of 8 months aged pigs were performed. Mast cells were found in all three layers of ureteral wall, but their distribution was irregular and the number unequal. It was established that alcian blue (AB)-positive mast cells were significantly more than toluidine blue (TB)-positive mast cells. A statistically significant smaller number of both AB and TB-stained mast cells were observed in the tunica mucosa. The largest number of mast cells was found in the tunica muscularis. In the adventitia, mast cells were higher in number in the main connective tissue than in the connective tissue near the blood vessels. Mast cells stained with TB showed variably expressed gamma-metachromasia, which was best visible in those situated in the lamina propria of the mucosa. The prevailing parts of mast cells, however, were AB-positive after AB-safranin staining. This was mostly found in mast cells of the tunica muscularis and in mast cells of perivascular location in the tunica adventitia. Immunocytochemically, mast cells were found to be positive for histamine and vasoactive intestinal polypeptide in the muscle coat, and to histamine in the adventitia, as well. On the basis of obtained results it was presumed that the mast cells in porcine ureter most probably took part not only in keeping of local homeostasis, but played also an important role of mobility of smooth muscle cells in the middle layer of ureter on one hand, and, on the other, in the adventitial blood vessels.     

Comparison of tracheal aspirates and bronchoalveolar lavage in racehorses. 1. Evaluation of cytological stains and the percentage of mast cells and eosinophils

OBJECTIVE: To compare a fast Romanowsky cytological stain (Diff-Quik) and Leishman's stain for the detection of mast cells in samples from the lower airways of racehorses, and to compare the proportion of mast cells and eosinophils in the total inflammatory cells in tracheal aspirate (TA) with those in paired bronchoalveolar lavage (BAL) samples. DESIGN: Retrospective case series of 48 young Thoroughbred and Standardbred racehorses. PROCEDURE: Fifty-one paired TA and BAL samples were collected after treadmill exercise from 48 horses with poor racing performance. Two slides were prepared from each sample; one was stained with Diff-Quik stain and the other with Leishman's stain. Differential cell counts of eosinophils and mast cells were recorded from each slide. Comparison of the suitability of the stains for the detection of mast cells, and comparisons of eosinophil and mast cell percentages in TA and BAL samples were analysed using the non-parametric Wilcoxon matched pairs test. RESULTS: Percentages of mast cells were significantly higher in Leishman than in Diff-Quik stained slides in both TA (P = 0.03) and BAL samples (P < 0.0001). Mast cell percentages were significantly higher in BAL than in TA samples using Leishman's stain (P < 0.0001). There was no significant difference in eosinophil percentages between TA and BAL samples (P = 0.07). CONCLUSIONS: Fast Romanowsky type stains (for example Diff-Quik) are not appropriate for the detection of mast cells in samples from the equine lower respiratory tract. Therefore, a metachromatic stain that reliably identifies mast cells (for example Leishman's) should be used if evaluation of mast cells in lower respiratory tract is undertaken. Mast cells are predominantly found in the distal small airways and alveoli sampled with a BAL. In contrast, eosinophils appear to be evenly distributed in the lower respiratory tract. However, high percentages of eosinophils are occasionally found only in TA samples. We recommend that both a TA and BAL be used for the evaluation of eosinophils and mast cells within the equine lower respiratory tract.     

Characterisation of tryptase and a granzyme H-like chymase isolated from equine mastocytoma tissue.

Mast cell proteinases are important inflammatory mediators in man and other species, but until now there has been no investigation of the nature of equine mast cell proteinases. These studies describe the purification and characterisation of two proteolytic components from equine mastocytoma tissue, detected using chromogenic substrates for trypsin and chymotrypsin. Following chromatographic purification, the trypsin-like component was found to be equine mast cell tryptase by N-terminal amino acid sequencing, showing a close similarity with human tryptase-beta (85% identity over 20 residues). It also had similar subunit molecular size (34-36kDa by SDS-PAGE) and substantially similar cleavage specificity to human tryptase-beta with the substrates tested. A 32kDa chymotrypsin-like component was also purified from mastocytoma extract, and termed equine mast cell proteinase-1 (eqMCP-1). The N-terminal amino acid sequence of eqMCP-1 was very similar to human granzyme H (95% over 19 residues). Rabbit antisera directed against tryptase and eqMCP-1 both detected equine mast cells by immunohistochemistry, and will be of use in future clinical studies of the relevance of mast cell proteinases in equine allergic disease.     

Secretory component and IgA expression by epithelial cells in sow mammary gland and mammary secretions

Secretory component (SC) and IgA expression of epithelial cells were studied in the mammary tissue and mammary secretions of sows. In mammary tissue, SC was not detected until day 105 of gestation. From the time of delivery (day 115) to the time of established lactation, the proportion of epithelial cells containing sc rose from 20 per cent to nearly 100 per cent. There was no IgA in alveolar epithelial cells until day 105 of gestation; on day 115, IgA positive epithelial cells were present in 10 per cent of the alveoli, which increased to 80 per cent during lactation. Epithelial cells represented more than 20 per cent of the total cells in colostrum, and predominated over leucocytes in milk. In colostrum, these epithelial cells (9 to 15 μm) showed weakly positive membrane, sc, contained cytoplasmic SC and had a limited capacity for in vitro proliferation. Ten per cent of epithelial cells contained intracytroplasmic IgA. In milk, the epithelial cells were larger (15 to 40 μm) with a higher expression of both membrane and intracytoplasmic sc; 66 per cent of these cells expressed intracytoplasmic IgA. These data showed that the capacity of mammary epithelium to process IgA to secretory IgA was complete at the end of mammary gland organisation, and established that the epithelial cells of milk contribute to the transfer of IgA to neonates.     

Mast cells and canine mast cell tumours. A review

Summary

This article reviews the literature on mast cells and tumours derived from mast cells in the dog. Mast cells play a central role in inflammatory and inunune reactions. Mast cells, normal and neoplastic, contain and release important biologically active substances: heparin, histamine, eosinophilic chemotactic factor and proteolytic enzymes.

Mast cell tumours occur in the dog, particularly in the boxer and related breeds, in the skin and less frequently in the intestines. Cytology usually provides an accurate diagnosis, but histological examination adds further information concerning the histologic grade and the completeness of surgical therapy. Cutaneous mast cell tumours should be regarded as potentially malignant and therefore be removed widely (3 cm. margin). Local recurrence, regional and distant metastases together with paraneoplastic disorders may cause the death of the pet. Histologic grading (2 or 3 grades) and clinical staging together with kinetic parameters and breed (boxers have relatively benign tumours) are important prognostic parameters. Based on prognostic criteria, surgical treatment should be completed with adjuvant radiotherapy, corticosteroids and eventually with combined chemotherapy. A novel, promising therapy is the application of the receptor kinase inhibitor. The study of the pathogenesis of mast cell tumours received new impetus by the finding of mutations, deletions and duplications, in exons 11 and 12 of the C‐kit oncogene. Further study of physiological and oncological aspects of mast cells are favoured by the availability of mast cells isolated from spontaneous mast cell tumours and of cultured cell lines.