Immunohistochemical characteristic of C cells in European bison thyroid gland

Introduction. C cells constitute a small percentage of thyroid gland parenchyma. The number, morphology and distribution of C cells differ among species; however, data regarding their characteristics in European bison are sparse. The aim of this study was to evaluate the morphology, distribution pattern and percentage of C cells in European bison thyroid gland together with morphometric analysis.Material and methods. Thyroid glands from 28 European bisons of different sex and age were collected either in autumn-winter (13/28) or in spring-summer (15/28) periods and analyzed by immunohistochemistry.Results. The mean total C cell number per all endocrine (follicular and C cells) cell number (C cell concentration) was 7.33%. The tendency to increase the C cell number from periphery to the central region of thyroid lobe was observed with the mean C cell concentration of 3.95%, 7.89% and 9.97% in peripheral, intermediate and central areas, respectively. Most frequently, C cells were situated intrafolliculary whereas epifollicular and interfollicular positions were observed less often. C cells were polymorphic with long cytoplasmic processes. The mean C cell area was 61.97 μm2 and the mean C cell perimeter, length and width were: 34.92 μm, 12.85 μm and 4.91 μm, respectively. In the majority of C cells, strong immunohistochemical cytoplasmic reaction was observed with the mean color intensity of 78.32. In autumn-winter period, C cells were significantly larger with lower color intensity than during spring and summer.Conclusions. This study leads to deeper characteristics of thyroid gland C cells in European bison. The histomorphometric data suggest that in European bison production of calcitonin by C cells may differ depending on the time of the year

Biopsy and tracheobronchial aspirates as additional tools for the diagnosis of bovine tuberculosis in living European bison (bison bonasus)

CITATION: Didkowska, Anna et al. 2020. Biopsy and tracheobronchial aspirates as additional tools for the diagnosis of bovine tuberculosis in living European bison (bison bonasus). Animals, 10(11):2017, doi:10.3390/ani10112017.The original publication is available at: https://www.mdpi.comENGLISH ABSTRACT: The diagnosis of bovine tuberculosis (BTB) in living wildlife remains a complex problem, and one of particular importance in endangered species like European bison (Bison bonasus). To identify infection and avoid the unnecessary culling of such valuable individuals, current best practice requires the collection and culture of material from living animals, as mycobacteria isolation remains the gold standard in BTB diagnosis. However, such isolation is challenging due to the need for the immobilization and collection of appropriate clinical material, and because of the sporadic shedding of mycobacteria. In the present study, we evaluated the potential of sampling for the detection of BTB in a group of seven living European bison suspected of being infected with Mycobacterium caprae. The specimens were collected both as swabs from the nasal and pharyngeal cavities, tracheobronchial aspirates (TBA), ultrasound-guided biopsies from lateral retropharyngeal lymph nodes, and post mortem, from mandibular, retropharyngeal and mediastinal lymph nodes. Clinical samples were tested for mycobacterial species via mycobacteriological culture and PCR. M. caprae was isolated from collected material in two out of four living infected individuals (TBA, biopsy) and mycobacterialDNAwas detected in three out of four (TBA, pharyngeal swab) bison. This is the first report of isolation of M. caprae in living European bison. Our findings demonstrate the value of diagnostic tests based on both molecular testing and culture in European bison and confirm the respiratory shedding of viable M. caprae in this host species.Publisher's versio

Histology, histochemistry and fine structure of the Harderian gland, lacrimal gland and superficial gland of the third eyelid of the European bison, Bison bonasus bonasus (Artiodactyla: Bovidae)

ABSTRACT The macroscopic anatomy and the microscopic and ultrastructural features of the Harderian gland (HG), lacrimal gland (LG) and superficial gland of the third eyelid (SGTE) of the adult European bison are described. In addition, morphometric studies were conducted and were followed by statistical analysis of the results. Tissue sections were stained with hematoxylin and eosin, methyl green-pyronin Y, periodic acid-Schiff, Alcian blue pH 2.5, aldehyde fuchsin and Hale's dialysed iron. Analysis of the staining showed that the HG has a multilobular tubuloalveolar structure with mixed secretion. The LG and the SGTE have a multilobar tubuloacinar structure with serous secretion in the LG and mucoserous in the SGTE. The TEM study demonstrates that the secretory cells of the HG, LG and SGTE have similar ultrastructural appearance, with two types of secretory vesicles in the cytoplasm of all studied glands. The histochemical staining methods and the TEM study revealed the secretory activity in the HG, LG and SGTE ducts. The structural studies can be important for establishing relations between morphological structure and functions of these glands. It can have clinical implications especially when taking into consideration the protective mechanisms of the eye

Additional file 1: of The morphology of the adrenal gland in the European bison (Bison bonasus)

Measurements of the adrenal glands in the studied European bison population. (DOC 275 kb