<div>The present study was aimed to examine histochemical changes in the Harderian gland of pre and post hatched chicks from 11 day of incubation to 24 days of age. In pre hatched groups, the gland was in the developing stage. There was no well defined parenchyma, septa and capsule in early embryonic stage. Histochemical observation revealed that weak or negligible activity of PAS, AB/PAS and Sudan black B was seen in epithelial lining of Harderian gland on 18th and 20th day of incubation. The gland was compound tubule-acinar type at 20th day of incubation, consisted of capsule, parenchyma and stroma. PAS activity was seen in the capsule, septa, epithelial lining of acini and tubule and interstitial connective tissue cells. PAS activity was aggregated towards the apical part of the tubular epithelium as well as at the free luminal surface epithelium of the acini. PAS activity increases with the development of connective tissue component of Harderian gland with the advancement of age. The Harderian gland was predominantly mucus and lipid secreting gland. All epithelial cells of the glandular unit of Harderian gland contain both neutral and acidic mucin. Intense AB-positive activity was seen at the apex of tubule with the advancement of age. Sudan black B activity was recorded in the cytoplasm of epithelial lining of tubule and acini of the Harderian gland and their presence increases with age.&nbsp;</div>

<div>Histochemical changes during development of Harderian gland in chicken</div>

Background: Pati duck population constitutes a major indigenous non-descript economically important duck variety in Assam. Harderian gland acts as a part of the head associated lymphoid tissue (HALT) and provides local innate immunity to the upper respiratory system, to the eye and oral cavity. Since literature on histoenzymic or histochemical study of harderian gland of Pati duck was scant, hence the present study was designed to establish the basic histoenzymic details on harderian gland of Pati duck of Assam. 
 
Methods: The present study was conducted on total forty five (45) Pati duck of Assam. Ducks were divided into five groups: 0, 4, 16, 24, and 42 weeks. For histochemical parameters, tissue samples were preserved in deep freeze maintained at -80oC (except for PAS-alcian blue, where paraffin sections were utilized) immediately after collection. The preserved tissue samples were shifted directly to cryostat microtome maintained at -22oC. The frozen sections were cut at 7 &micro;m thickness and were collected on clean slides and were treated as per the method of Singh and Sulochana (1978). 
 
Result: Histochemical studies revealed that the reaction of Alkaline phosphatase enzyme was mildin Harderian land of Pati duck. The reaction of the acid phosphatase was absent. The Adenosine triphosphatase (ATPase) activity was observed moderate in all the age groups. The activity of non specific esterase was observed strong in all the age groups. The periodic acid-Schiff (PAS-Alcian Blue 2.5 pH) stain revealed positive reaction in all the age groups which indicated the presence of acid sulfated mucosubtances in the cells.

Histochemical Study of the Harderian Gland of Pati Duck of Assam

Background: Equine sarcoid is a rare equine skin tumour seen in any age group of horses, usually in younger horses. Grossly, it appears as multinodular masses which may or may not ulcerate and pink to greyish white coloured. It was suggested that the papilloma virus is a causative organism along with predisposing factors like skin abrasions and wounds. The definitive diagnosis is based on histopathology and classified according to their gross appearance and clinical behavior. To find out the origin and proliferative nature, histochemical and immunohistochemical study was performed. The present communication reflects various patterns of sarcoid on histopathological examination and it was confirmed by histochemistry and immunohistochemistry. 
 
Methods: A four-year-old bay colt was presented to the Madras Veterinary College Teaching Hospital with nodular masses on the buccal cavity. Fine needle aspiration biopsy (FNAB), blood, serum and tumour biopsy materials were collected under local anesthesia. The collected samples were subjected to Leishman-Giemsa staining, haematological and biochemical analysis, histopathology, histochemical and immunohistochemical examination. 
 
Result: Histopathologically, there was mucosal hyperplasia and hyperkeratosis. The neoplastic cells were arranged as storiform or whorl-like pattern. Also, there was perpendicular orientation of fibroblasts towards the basement membrane (picket fence) at the dermo-epidermal junction, which was considered as characteristic feature of sarcoid. Histochemical examination with Picrosirius red revealed strong positivity characterised by deep red coloured mature collagen fibres. Immunohistochemically, the hyperplastic epithelial cells were positive for pan cytokeratin and fibroblast cells were strongly positive for vimentin. Based on the histopathology, histochemistry and immunohistochemistry, the condition was diagnosed as sarcoid which is rare in horses.

Equine Sarcoid-histomorphological, Histochemical and Immunohistochemical Studies in A Thoroughbred Horse

Background: Energy is the important part of any life, the potential energy present in the tissue in the form of chemical energy. Presence of glycogen as glucose is source of energy for cell division, differentiation, delamination and maturation process as essential process in histogenesis of foetal organ. Glycosaminoglycans, also known as mucopolysaccharides, are long chains of sugar occurs in different proportion in different tissue and their distribution in compartment of ruminant stomach varied in foetus of different CRL. Copmartment of ruminant stomach abomasum , omasum, reticulum and rumen was contributed grossly in varied proportion from initial stage to full term of prenatal stage. In initial stage rumen is largest compartment with advancement of development omasum is largest compartment&nbsp; followed by reticulum and abomasum at full term.&nbsp;As per morphology and histology of varied compartment there could be probability of varied intensity of histochemical reaction in different layer of tissue as per their ebryogenesis.&nbsp;Kosali cattle is registered 36th breed of India. Kosali the native breed of Chhattisgarh, known for its compact body, disease tolerance and well maintained in agricultural waste. More than total 60% Kosali cattle are concentrated in the central plains of the C.G. state. There is paucity of Cited literature, literally no scientific documentation regarding presence and distribution of glycogen and mucopolysaccharides in rumen, reticulum, omasum and abomasum of prenatal Kosali cattle. In view importance of Kosali cattle concern with livelihood of farmers in Chhattisgarh, varied degree of development of compartment of stomach and paucity of literature regarding intensity of histochemical reaction&nbsp; from initial to final term of prenatal stage present research was undertaken. 
 
Methods: In light of above background in twenty four Kosali foeti were collected and on the basis of CR length categorizedin to four groups with six foeti in each group i.e. Group I (below 20 cm CRL), Group II (Above 20 up to 40 cm CRL), Group III (Above 40 up to 60 cm CRL) and group IV (Above 60 cm CRL) , tissue samples ofrumen, reticulum, omasum and abomasum were collected and processed&nbsp; for study of glycogen and mucopolysaccharide by PAS and&nbsp; AB-PAS method respectively. 
 
Result: Apparently in group I PAS&nbsp; activity was either not observed&nbsp; as in reticulum or very mild in rumen, omasum and abomasum and was greater in abomasum. In epithelium, propria submucosa and serosa PAS activity increased slowly mostly from mild to moderate while in glands reaction was intense. However in tunica muscularis of rumen reaction decreased from group III to IV , in omasal tunica muscularis and omasal laminae from group II to IV. In group I PAS activity was higher in pyloric region than cardiac stomach. AB-PAS activity for neutral mucopolysaccharide was&nbsp; observed in epithelium and tunica muscularis of rumen, reticulum, omasum and abomasum in all groups, mixed mild activity for both neutral and acid mucopolysaccharide in propria submucosa in group I and II. In fundic region in group III and IV in glands intense acid mucopolysaccharide reaction was seen in patches in forerunner parietal cells.

Prenatal Histochemical Study of Stomach in Kosali Cattle

<div>Background: Kidneys, the paired organ which essentially plays for excreting nitrogenous wastes, excessive water, inorganic salts and toxic substances produced during the process of body metabolism. Maintenance of osmotic regulation and homeostatic fluid balance of the body has also be performed by kidneys. Each of the kidneys filtrate carried to cloaca by respective ureter from where the urine leaves the body. The present macroscopic, histomorphological and histochemical studies undertaken on the Kidneys of Guinea fowl (Numida meleagris) is nothing but the attempt to widen our thrust area for that bird which is nonexistent as on documentation. 
 
Methods: The present studies were carried upon 12 pairs of in-vitro kidney samples in Guinea fowl. Gross morphology and morphometrical observations were carried on fresh specimens. Histological studies were carried on fixed samples those were processed for dehydration, clearing, embedding into paraffin and sections of 5-6 &mu; thickness were obtained. Different staining procedure as to Haematoxylin and Eosin, Silver orcein, Aniline blue and Weigert&rsquo;s staining methods were employed for different histological components. The histochemical and histoenzymic studies were also accomplished with Periodic acid Schiff&lsquo;s (PAS), Alcian blue methods (pH-2.5) and Gomori&rsquo;s cobalt method for Alkaline phosphatase and Acid phosphatase. The Succinic dehydrogenase enzyme was also estimated on cryostat sections. 
 
Result: The observations on kidneys of Guinea fowl were accomplished after macroscopic, histomorphological and histochemical means. This reddish-brown colored paired organ of kidneys was retroperitoneally placed in synsacral fossa and had incomplete division of three parts. The wrapping material of capsule was the dense connective tissue. The outer cortex and inner medulla had different parts of nephrons. Two types of nephrons viz. mammalian type (with Henle loop) and reptilian type (without Henle loop) were observed. Collagen, elastic and reticular fibers were there in different components of the kidney. Histochemically it has determined the secretion of neutral as well as acidic mucopolysaccharide substances. PAS activity was observed at mesangial cells and basement membrane of DCT. The Alkaline phosphatase showed the positive activity in capsule, brush border of proximal and distal convoluted tubules. The Acid phosphatases were showing intense activity in parietal and visceral layer of renal corpuscles, lumen and basement membrane of PCT. The intense activity of Succinic dehydrogenase showed at PCT, DCT, collecting tubule whereas renal corpuscles showed feeble activity.</div>

<div>Macroscopic, Histomorphological and Histochemical Studies on the Kidneys of Guinea Fowl (Numida meleagris)</div>

The histological and histochemical structure of lingual salivary glands in mole rat (Spalax leucodon) were studied using histochemical staining techniques to provide information of its salivary glands. A total of five adult mole rat (Spalax leucodon) were used as the material. It was observed that serous and mucous glands are placed in the root of the tongue. It was detected that although the mucous gland cells were rich in terms of AB pH 0.5, 1.0, 2.5 and AF (+) mucosubstance, the PAS and KOH/PAS mucosubstances showed very weak reaction, and this mucosubstances were present at a very less amount in serous gland cells. &nbsp;In the PAS/AB staining, it was found that the serous and mucous gland cells showing only AB or only PAS reaction and also AB AB pH 2.5 (+) cells were found. The same findings were observed in serous glands by AF/AB staining. Consequently, the present study demonstrated characteristic features of the lingual salivary glands of the mole rat, and it revealed histological and histochemical data both in accordance with and different from that for the lingual salivary glands of mammals and other species.

Histological and histochemical structure of lingual salivary&nbsp;glands in mole rat (Spalax leucodon)

<div>Background: Gmelina arborea Roxb. is a fast-growing plant that has been utilized as feed resource for livestock production particularly for goat production. However, this plant was noted to contain toxic compounds which can affect the production and performance of livestock animals. These contradictory results is the primary reason of determining the localization of secondary products which is commonly noted as toxic compounds in plants. Thus, this study aims to provide baseline information on cell and tissue localization of different plant secondary products present in Gmelina arborea. 
&nbsp; 
Methods: Field-laboratory investigation was conducted in the last quarter of 2021. Localization of these compounds were determined by sectioning and histochemical analysis. Stains and reagents were used to detect the location of these compounds. 
&nbsp; 
Result: Most of the secondary products were detected in the epidermis, parenchyma and collenchyma in the cortex and near vascular tissues and mesophyll cells of the lamina. The results of this study support the results of different phytochemical studies conducted using this plant. This is an indicator that plant secondary products are widely distributed in the different parts of the plant. Considering plants as forage for livestock, especially for goats, necessitates the consideration on the presence and localization of these phytochemicals as these may have nutritional and toxic effects.</div>

Histochemical Analysis of Gmelina arborea Roxb. and its Implication as Forage for Goats

<div>Background: Chabro is a strain of poultry birds especially designed for backyard farming and is more adoptive to climatic variations in the tropics. The thyroid gland plays an important role in controlling basal metabolic rate. Histochemical changes of the gland in association with seasonal changes have not been studied so far in Chabro chicken. The present study describes the season related variations in the histochemistry of thyroid gland.&nbsp;&nbsp; &nbsp; 
 
Methods: The histochemical study was conducted on thyroid gland of eight to ten weeks old 24 apparently healthy Chabro chickens procured from Poultry Farm, DUVASU, Mathura. The birds were divided into two groups consisting of 12 chickens in each group reared in summer and winter seasons. 
 
Result: The capsule showed mild reaction for PAS, protein and glycogen. Follicular cells showed intense reaction for bound lipids, protein and alkaline phosphatase. The colloid in summer season showed strong reaction for PAS at periphery and very strong reaction at center while in winter colloid showed strong PAS positive activity. The Chabro chicken thyroid was functionally more active in winter as compared to summer season because of increased diameter of all follicles and concentration of thyroid hormones level in winter season.</div>

<div>The Histochemical Study of the Thyroid Gland of Chabro Chicken Reared in Summer and Winter Seasons</div>

<div style="text-align:justify">The present study was carried out to observe the histochemical details of the lacrimal gland in ruminants. The lacrimal gland located at the dorsolateral aspect of the eyeball which helps to nourish the cornea. In the present study a strong PAS positive reaction were seen in the secretory units of lacrimal gland in cattle, sheep and goat whereas, few secretory units showed strong PAS positive reaction and few secretory units showed weak PAS positive reaction in buffalo. Few secretory units and few secretory cells in some secretory units showed positive reaction for Alcian blue at (pH 2.5) in cattle, buffalo, sheep and goat. Intralobular and interlobular lipids were observed in buffalo, sheep and goat.</div>

Comparative histochemical studies of lacrimal gland in Ruminants &nbsp;

<div>Background: Acetylcholinesterase (AChE) is an enzyme belonging to hydrolase group which splits the acetylcholine in to choline and acetate. It is supposed to be a marker of cholinergic and cholinoceptive neurons. Acetylcholinesterase histochemisry has been done in a number of vertebrates but it is still obscure and scattered in fishes, particularly in Indian fishes.&nbsp; 
 
Methods: In the present study a modified histochemical technique has been employed to histochemically map the acetylcholinesterase containing neurons in the telencephalic and diencephalic nuclei of C. punctatus described by Hedreen, et al (1985). 
 
Result: Acetylchoinesterase is differentially expressed in the various prosencephalic centres and nuclei of the brain, thus its staining clearly demarcates these centres and nuclei based on varying enzyme intensity. Among the pallial nuclei of the forebrain, medial and dorsolateral nuclei showed intense enzyme activity while ventral dorsolateral nucleus and central nucleus showed moderate reaction. In contrast, most of the subpallial nuclei of the forebrain showed high intensity. Diencephalic nuclei of the forebrain exhibited mosaic pattern of enzyme distribution.&nbsp;</div>

Histochemical changes during development of Harderian gland in chicken

Histochemical Study of the Harderian Gland of Pati Duck of Assam

Equine Sarcoid-histomorphological, Histochemical and Immunohistochemical Studies in A Thoroughbred Horse

Prenatal Histochemical Study of Stomach in Kosali Cattle

Macroscopic, Histomorphological and Histochemical Studies on the Kidneys of Guinea Fowl (Numida meleagris)

Histological and histochemical structure of lingual salivary glands in mole rat (Spalax leucodon)

Histochemical Analysis of Gmelina arborea Roxb. and its Implication as Forage for Goats

The Histochemical Study of the Thyroid Gland of Chabro Chicken Reared in Summer and Winter Seasons

Comparative histochemical studies of lacrimal gland in Ruminants

Histochemical Distribution of Acetylcholinesterase in the Forebrain Nuclei of an Indian Non Catfish Channa punctatus