Geetha Ramesh

Thymic Hassall’s corpuscles in Nandanam chicken - light and electronmicroscopic perspective ( Gallus domesticus )

The present study was aimed to study the light and electron microscopic studies of thymic Hassall’s corpuscles was done in various age groups of Nandanam Chicken ranging from day-old to forty weeks. Hassall’s corpuscles are special, unique structures present in thymic medulla and also in the cortex of all the age groups of Nandanam chicken (from hatch to forty weeks) in the present study. Size of the Hassall’s corpuscles in the medulla is larger than the ones present in the cortical region of thymus. The Hassall’s corpuscles are made up of structureless eosinophilic mass surrounded by concentrically arranged reticuloepithelial cells. Under electron microscope, the Hassall’s corpuscles were composed of reticuloepithelial cells interconnected by many desmosomes. The epithelial cells had abundance of cytoplasmic fibrils and desmosomes with few mitochondria and ribosomes. The nucleus was oval or round which was slightly indented. The centre of the Hassall’s corpuscles was appeared either solid or cystic. The cystic corpuscles had cell debris within the cyst lumen.

Morphological Analysis of Testis of the Guinea Fowl ( Numida meleagris ) Under Tropical Savannah Climate of India

The present study aimed to document the seasonal variations in the testicular morphology of the adult guinea fowl (Numida meleagris ) under tropical savannah climate of India. The study was conducted in 24 adult healthy guinea cocks. The testes were ovoid in shape throughout the year. The consistency of the testes was moderately firm with great resilience and creamy white in colour during summer and monsoon-I whereas soft in consistency and dull white to yellowish tinge in colour during monsoon-II and winte r seasons. The testicular weight, length, width, thickness, volume and circumference were higher during summer and monsoon I than the winter and monsoon II seasons. The mean body weight of the birds did not show significant difference among the seasons. The tes ticular weight, length, width, thickness, volume and circumference were higher during the summer and monsoon I than the winter and leas during monsoon II in the current study. The gonadosomatic index (GSI) and paired testicular weight were high and showed no sign ificant difference during the summer and monsoon-I whereas during winter and monsoon-II, the values were low and showed significant difference between them. The diameter of the seminiferous tubules and its lumen, the diameter of the sustentacular cells (Serto li ce ls) were much higher during summer and Monsoon I than winter and monsoon II seasons. The percentage area of interstitial cells and the thickness of the testicular capsule appeared less during the summer and monsoon I seasons. The decreased size of seminiferous t ubules, increased amount of cellular debris in the tubular lumen, degenerating germ cells and collapse of seminiferous tubules observed during monsoon II and winter in the present study.

Morphology, Distribution and Functional Significance of Dendritic Cells (DCs) in the Skin of Domestic Animals

Dendritic cells (DCs) are a heterogeneous population of leukocytes that are critical in orchestrating immune responses in skin and also in mucosa (Manickam et al., 2007), and contain large organelles called Birbeck granules (Young et al., 2000). These cells are also known as antigen-presenting immune cells associated with squamous epithelia and mucosa. DCs were first described by Paul Langerhans, in 1868, as dendritic shaped cells, which are located in the squamous epithelia of epidermis. Later on, these cells are identified in all stratified squamous epithelium in mammals. The DCs originate from the bone International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 7 Number 05 (2018) Journal homepage: http://www.ijcmas.com

In-vitro Labelling of Ovine Adipose-Derived Mesenchymal Stem Cells (oADMSCs) and Tracking Using MRI Technique

Abstract To understand the mechanisms standing behind a successful stem cell-based therapy, the monitoring of transplanted cell’s migration, homing as well as the engraftment efficiency and functional capability in-vivo has become a critical issue. The present study was designed to track the labelled oADMSCs in-vitro and its visualization through MRI technique. oADMSCs from passage 4 (P-4) to passage 6 (P-6) were labelled with superparamagnetic iron oxide (SPIO) conjugated with rhodamine (Molday Ion Rhodamine-B - MIRB) at the concentration of 25μg Fe/ml in DMEM. Internalized MIRB was observed under fluorescent microscope after 72 hrs of incubation. Labelled oADMSCs showed Prussian Blue positive reaction demonstrating the iron uptake of the cells. The viability of the MIRB-labelled oADMSCs ranged between 98-99 per cent and Trypan blue exclusion test showed no significant difference in viability between labelled and unlabelled oADMSCs. MR signal in control group of cells was similar to that of water. MR signals or fluorescence in MIRB-labelled cells decreased with increasing concentrations of iron. The T2 weighted images of MIRB-labelled oADMSCs increased with increasing concentrations of SPIOs. The MIRB was found to be nontoxic, and did not affect proliferation capacity in-vitro.

Morphology of the Interstitial Tissue of Active and Resting Testis of the Guinea Fowl

The morphology of the interstitial tissue of sexually active and resting testis of the guinea fowl were studied. Six adult health birds of active and resting phases of reproductive cycle were used for this study. The interstitial tissue consist ed of loose connective tissue, interstitial cells (Leydig cells), few connective cells, blood vessels and adrenergic nerve fibres in the pr esen study in both active and resting testes. The interstitial tissue was compact in sexually active testis whereas, the volume of the tissue was found to be increased in resting testis. The loose connective tissue of the interstitial tissue composed of mainly of collagen fibres an d few reticular fibres whereas elastic fibres were absent in both groups studied. The interstitial cells appeared in clusters of a few cells an d were relatively less in the active testis than the resting testis. The interstitial cells were pale staining or polygonal cells with euchromatic nuclei with few large lipid droplets in the active testis whereas the cells were flat and highly heterochromatic with numerous small l ipid drop ets in resting testis. Few macrophages were found only in resting testis. Interstitial cells showed negative reaction to alkaline, acid phosphatases and PAS in both groups studied but positive for lipids. The interstitial tissue was well vascularised with centrally located bl ood vessels in the active testis whereas the blood vessels were small and inconspicuous in the resting testis. The lymphatic vessels were n ot identified in both groups studied.

In-Vitro Culture Morphology of Spermatogonial Stem Cells (SSCs) in Mice

Spermatogonial Stem Cells (SSCs) from pre and post-pubertal age groups of mice were isolated by two step enzymatic digestion method and cultured in six-well plates. The in-vitro culture morphology of the SSCs was observed upto passage 2. In primary culture (P0), on day two, the cells were single and transparent. On day 4, the colony forming unit consisted of four to five cells. Three dimensional colonies were observed on day seven post incubation. From day eight onwards, the cells had spindle shape and showed varied morphology till twelve days post incubation. Double nucleolus is prominent in cells on day eight post incubation. In passage 1, though the cells exhibited different morphology viz., round, stellate, polyhedral, and triangular, the stellate cells were found to be more. In passage 2, the spindle-shaped cells with prominent nucleoli were often observed. Other cell morphology like round, stellate, polyhedral and triangular cells were also observed.

Microarchitecture of the Palatine Tonsil in Sheep (Ovis aries)

SUMMARY: The tissue pieces of palatine tonsil were collected from different postnatal age groups of sheep from the Corporation Slaughter House, Perambur, Chennai. The palatine tonsil consisted of a surface epithelium, capsule, tonsillar lobes, crypts, crypt epithelium and tonsillar follicles. The surface epithelium over the palatine tonsil was made up of non-keratinized stratified squamous epithelium in all the postnatal age groups studied. The palatine tonsil was clearly demarcated from the surrounding structures by a distinct connective tissue capsule and one septa dividing the tonsil into two lobes. The surface epithelium was invaginated into the substance of the tonsil to form primary and secondary crypts in each lobe. The crypt epithelium covered the regions of lymphoid follicles became lymphoepithelium. The macrophages were also observed in the epithelium. In the areas of lymphoepithelium the basement membrane was interrupted since lymphocytic infiltration was heavy into the epithelium. Numerous secondary tonsillar follicles with germinal centers separated by interfollicular areas were observed in the palatine tonsil. The tonsillar follicles consisted of a mantle zone, which was heavily populated with small darkly stained lymphocytes. These mantle zones were always oriented towards the crypts. The tonsillar follicles of young sheep showed many medium and small sized lymphocytes, lymphoblasts and also reticulocytes. The reticular cells usually appeared larger than lymphocytes and had a more abundant and organized cytoplasm with vacuoles. ˚