Participation of Tumor-Associated Myeloid Cells in Progression of Amelanotic Melanoma (RMM Tumor Line) in F344 Rats, with Particular Reference to MHC Class II- and CD163-Expressing Cells

Tumor progression is often influenced by infiltration of myeloid cells; depending on the M1- or M2-like activation status, these cells may have either inhibitory or promoting effects on tumor growth. We investigated the properties of tumor-associated myeloid cells in a previously established homotransplantable amelanotic melanoma (RMM tumor line) in F344 rats. RMM tumor nodules were allowed to reach the sizes of 0.5, 1, 2 and 3 cm, respectively. Immunohistochemistry and flow cytometry was performed for macrophage markers CD68 and CD163, and for the antigen-presenting cell marker, MHC class II. Although no significant change was observed in the number of CD68⁺ and CD163⁺ macrophages during RMM progression, the number of MHC class II⁺ antigen-presenting cells was reduced in 3 cm nodules. Real-time RT-PCR of laser microdissection samples obtained from RMM regions rich in MHC class II⁺ cells demonstrated high expressions of M1-like factors: IFN-γ, GM-CSF and IL-12a. Furthermore, fluorescence-activated cell sorting, followed by real-time RT-PCR for CD11b⁺ MHC class II⁺ (myeloid antigen-presenting cells), CD11b⁺ CD163⁺ (M2 type myeloid cells), CD11b⁺ CD80⁺ (M1 type myeloid cells) and CD11b⁺ CD11c⁺ (dendritic cells) cells was performed. Based on the levels of inflammation- and tumor progression-related factors, MHC class II⁺ antigen-presenting cells showed polarization towards M1, while CD163⁺ macrophages, towards M2. CD80⁺ and CD11c⁺ myeloid cells did not show clear functional polarization. Our results provide novel information on tumor-associated myeloid cells in amelanotic melanoma, and may become useful in further research on melanoma immunity.

Cutaneous Histiocytic Sarcoma with Regional Lymph Node Metastasis in a Netherland Dwarf Rabbit (Oryctolagus cuniculus)

A 10-year-old male Netherland dwarf rabbit (Oryctolagus cuniculus) was presented with a red nodular mass (1 cm in diameter) with ulceration and hair loss in the skin of the left upper lip. Cytological examination revealed atypical round cells. The mass was excised surgically. Histologically, the mass was composed of large round to polyhedral neoplastic cells with marked cytological atypia. The neoplastic cells were often binucleated or multinucleated. Immunohistochemically, the neoplastic cells were intensely positive for Iba1 and vimentin, but fewer neoplastic cells expressed E-cadherin. Nuclear immunoreactivity for Ki67 was detected in approximately 41% of the neoplastic cells. Metastasis to the left cervical lymph nodes was detected 6 months after the surgical excision. Based on clinical, histopathological and immunohistochemical findings, the present case was diagnosed as cutaneous histiocytic sarcoma. To the authors' knowledge cutaneous histiocytic disease has not been reported previously in lagomorphs.

VISCERAL LEISHMANIASIS IS ENDEMIC IN GOLDEN JACKALS OF BANGLADESH AGRICULTURAL UNIVERSITY CAMPUS, A THREAT FOR EXPANDING FUTURE ZOONOTIC VISCERAL LEISHMANIASIS

Visceral leishmaniasis (VL), now a day, is an endemic protozoal disease of human in Bangladesh. The disease is transmissible to canids and endemic in canids in many parts of the world including western China and India. In Bangladesh, the occurrence of VL in canids is unknown. Golden jackals, a common wild canid of Bangladesh Agricultural University (BAU) Campus, living with street dogs, cats and often get closure to human shelter. It is not surprising to find VL in golden Jackals of BAU campus, Mymensingh and this study was, therefore, aimed to identify the occurrence of leishmanial infection in their visceral organs. Venous blood, liver, kidney, spleen and bone marrow from the jackals (N=5) were collected, impression smears from these organs were made onto clean slides and stained with Giemsa’s stain. Leishmanial pro - and amastigote stages of the parasite were detected in the impression smears made from liver, spleen, kidney and bone marrow in all jackals. Leishmanial amastigote stage of the parasite was seen in the macrophages of blood, spleen and liver. Part of liver, kidney, spleen and bone marrow from the jackal were fixed in 10% buffered neutral formalin and stained with hematoxylin and eosin (H&E). Histopathological study revealed scatteredly distributed microgranuloma in the hepatic parenchyma, consisting of closely packed collection of macrophages and lymphocytes with fibrous tissue encapsulation. In kidney, chronic glomerulonephritis was seen; the inflamed areas were infiltrated with lymphocytes and macrophages. Specific pathology in spleen and bone marrow was not observed. Genomic DNA was extracted from the liver, kidney, spleen and bone marrow of jackals. Polymerase chain reaction (PCR) with species specific primers were used to identify the species of leishmanial protozoa involved. Results of PCR showed 145bp amplicon, specific for Leishmania donovani infection in all five jackals. This is the first report in Bangladesh describing the occurrence of VL in golden jackals. This result reinforce the assumption that golden jackals of BAU campus harbour leishmanial protozoa, could serve as a symptomless carrier and transmit the infection to other canids and human, require further investigation.DOI: http://dx.doi.org/10.3329/bjvm.v10i1-2.15655

EFFECTS OF CHRONIC ARSENIC TOXICITY ON THE HAEMATOLOGY AND HISTOARCHITECTURE OF FEMALE REPRODUCTIVE SYSTEM OF BLACK BENGAL GOAT

This study was aimed to observe the effects of chronic arsenic toxicity on the haematology and histoarchitecture of female reproductive system of black Bengal goat. Adult She goats (N=4) were orally administered with sodium arsenite (4 mg/kg body weight) for first seven weeks followed by 5 mg/kg body weight for next eight weeks. Blood was collected from the treated goat at day0, 20, 40, 60, 80 and 100. There was significant difference of TEC, Hb concentration and TLC in goats which are chronically exposed with arsenic. Lymphocyte was decreased with the treatment of sodium arsenite but neutrophil, eosinophil and monocyte were increased. At the end of study the goats were euthanasized. The ovary, uterine tube, uterus, cervix and vagina were collected for gross and histopathological examinations. In histopathological examination the ovarian follicles appeared degenerated and there was much stromal thickening around the follicle. Thickened myometrial layer and shortened mucosal folds in the uterine tube were observed. There was reduction in the number and size of endometrial glands. The mucosal cell lines appeared degenerated. Thin vaginal mucosa and proliferation of connective tissue; shortened cervical crypts and thickened glandular epithelium of cervix were also observed. It may be concluded that chronic arsenic exposure might have adverse effects on the female reproductive system.DOI = http://dx.doi.org/10.3329/bjvm.v9i1.11214 Bangl. J. Vet. Med. (2011). 9(1): 59-66 

Isolation and serotyping of dengue viruses by mosquito inoculation technique from clinically suspected cases of dengue fever

Dengue virus was isolated from 44 clinically suspected cases of dengue fever by mosquito inoculation technique using Aedes aegypti mosquito in the department of virology, BSMMU in the year 2000. Identification of dengue virus was done by direct fluorescent antibody technique using FITC conjugated anti-dengue monoclonal antibody and serotyping was carried out by indirect fluorescent antibody technique using serotype specific monoclonal anti-dengue antibody. The dengue virus isolation rate was 41.9%. The result of serotyping revealed circulation of all four serotypes of dengue viruses in Dhaka, Bangladesh and DEN-3 was the predominant (70.5%) serotype during the outbreak in 2000. The rate of isolation was higher in patient's serum at an early stage of fever (p<0.01) and with higher body temperature (p<0.01). The rate of isolation was 77.77% in patient's serum collected on the 1st day of fever, and then the rate gradually declined and lowest (16.6%) on the 5th day of fever. The mosquito inoculation technique is an easy, economical and sensitive method for dengue virus isolation and is recommended for routine virological surveillance in laboratories of Bangladesh where sophisticated facilities are limited.