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

<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>

<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;

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: 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>

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

<div>Background: Pati ducks have been playing a vital role in Assam&rsquo;s rural economy. It is an established fact that the liver is an important organ in the body. Since literature on a detailed anatomical study of the liver in Pati ducks of Assam is scare, hence the present study was designed to establish the gross, histological and histochemical details on liver with advancement of age. 
 
Methods: The present study was conducted on 24 numbers of Pati ducks of Assam. They were divided into four (4) groups, each group containing six birds and kept for different ages i.e. 1 week, 8 weeks, 16 weeks and 24 weeks. The gross morphometry viz. length, breadth, thickness and weight of liver were observed. For histological study, tissue samples were fixed in 10% neutral buffered formalin. The processing and various methods staining were used according to <a href="#luna_1968">Luna (1968)</a>. For histochemical study, samples were stored at -80&deg;C in a deep freeze immediately after collection and they were treated according to <a href="#singh_1978">Singh and Sulochana&rsquo;s method (1978)</a>. 
 
Result: Morphometrical parameters showed an increasing trend with age. The lobules of liver were not distinct. Strong Alkaline phosphatase and Acid phosphatase activity were observed in the capsular area and bile canaliculi respectively.</div>

Gross Morphological, Histological and Histochemical Studies on Liver of Pati Ducks (Anas platyrhynchos domesticus) of Assam

<div style="text-align:justify">
Background: Skin is a versatile organ, which is extremely important for protection, perception, water regulation and wound healing. The skin of goat is considered extremely durable used by the tannery Industry to make rugs and carpet binding. 
&nbsp;

Methods: The present study was conducted on the skin of goats of either sex to study the age wise changes in the histomorphology, histochemistry and histoenzymology of dermis. The skin samples were collected from Nagpur Muncipal Corporation Slaughter house immediately after natural death and subsequently processed and stained for histological, histochemical and histoenzymic studies. The total of 220 samples, 20 each from different body regions namely dorsal neck, lateral neck, ventral neck, dorsal thorax, lateral thorax, ventral thorax, dorsal abdomen, lateral abdomen, ventral abdomen, lateral thigh and medial thigh were collected. The animals were divided into two groups, viz. six to twelve month of age (Gr I) and above one year age (Gr II). 
&nbsp;

Result: It was observed that the dermis was composed of collagen, elastic, reticular fibers, cells of connective tissue, blood vessels, nerves, hair follicles, sweat glands, sebaceous glands and arrector pili muscles in all body regions in Gr I as well as in Gr II. The dermis was divided into thin superficial papillary layer and a thick deep reticular layer. The dermal papillae were the upward projections of superficial papillary layer between epidermal pegs. In reticular layer, fibroblasts were larger, while in papillary layer, fibroblasts were thin long, compressed and spindle shaped. The collagen fibers were more in number as compared to other fibers in dermis and they were densely arranged in papillary layer and parallel with the skin surface below the epidermis. The elastic fibers were present in between the collagen fibers around the blood vessels and hair follicles. The arteriovenous shunt was found surrounded by capsule of connective tissue consisting of smooth muscle cells. The more number of hair follicles at deep part of papillary layer and few follicles were present in reticular layer. The hair follicle composed of outer root sheath, inner root sheath, cortex and medulla. The depth of primary hair follicle increased with the advancement of age. Moderate PAS positive activity was noted in the papillary layer, while it was weak to moderate in reticular layer. The reticular layer of the dermis showed moderate Sudan black B activity for the presence of lipid than the papillary layer. The mild acid phosphatase activity was seen in the papillary and reticular layer of dermis, while moderate acid phosphatase activity was noticed in the blood vessels. A mild alkaline phosphatase activity was present in dermis in Gr I and Gr II. 
&nbsp;

Conclusion: The present study would form a baseline data on the histomorphology, histochemistry and histoenzymology of skin of goat which would be helpful in future research prospective.
</div>

Histomorphological, Histochemical and Histoenzymic Studies on the Dermis of Skin of Goat (Capra hircus)

Background: Being the vital organ of circulatory system, the development of the heart before birth must be studied to safeguard the animal from the incidence of various developmental anomalies. The histochemical and biochemical details of cardiac architecture especially in pre-natal sheep have not yet been reported.&nbsp; &nbsp; 
 
Methods: The collected foeti of sheep were divided into three age groups viz. early prenatal (up to 50 days), mid prenatal (51-100 days) and late prenatal (101 to 150 days). The samples of heart were processed by routine paraffin technique and cryo technique and after section cutting, the slides were stained by various histochemical staining methods. Further, fresh pieces of the heart samples were also processed for getting tissue extracts for the biochemical analysis.&nbsp; &nbsp; 
 
Result: It was revealed that the PAS activity was observed in the cardiac wall, interatrial septum and interventricular septum in the sheep foeti at all stages of gestation. A variable degree of acid phosphatase activity was noted in the myocardium of heart wall in the sheep foeti at all stages of gestation. The lipid deposition also increased with advancing age in the myocardium of cardiac wall, interatrial septum and interventricular septum in the heart of sheep foeti. The activities of various enzymes like creatine kinase, alkaline phosphatase, serum glutamic-pyruvic transaminase and serum glutamic-oxaloacetic transaminase were high in left ventricle than the right ventricle in the heart of sheep foeti. Certain protein bands of specific molecular weight appeared in the ventricular tissue at specific age of gestation in addition to a group of common proteins which appeared in ventricular tissue of sheep foeti in all age groups under study.

Histochemical and Biochemical Developmental Studies on the Heart in Pre-natal Non-descript Sheep (Ovis aries)

<div>Background: The proventriculus, component of digestive system of bird secretes hydrochloric acid and pepsinogen which helps the churning of food material that takes place in ventriculus. Pepsinogen produces pepsin and it smashes the peptide bonds of amino acid of food material.&nbsp; 
 
Methods: The twelve proventriculus samples of Guinea fowl birds were fixed in 10% neutral buffered formalin and Bouin&rsquo;s fluid for &nbsp;histological procedure while chilled acetone and chilled ethanol were used as the fixatives for histochemical studies. The fresh unfixed samples were used on cryostat for studies of succinic dehydrogenase enzyme. 
 
Result: Histomorphologically the proventriculus of Guinea fowl was observed as the typical tubular component with four tunics from inside to outside as tunica mucosa, tunica sub mucosa, tunica muscularis and tunica serosa. The submucosal layer comprised with proventricular submucosal gland (PVSMG) which was encapsulated by elastic fibers. Tunica muscularis was inner longitudinal and outer circular layer, while the tunica serosa was observed with surrounding adipose tissue as the connective tissue constituent to endow the access of nutritional supply in the form of blood vessels. The luminal surface of proventricular submucosal glands has shown the significant activity of glycogen while intercalated, intralobular and interlobular ducts have exhibited the weak activity towards the same. The glandular cell rod of PVSMG, serosal layer and adjoining connective tissue with blood vessels has exhibited very weak activity of alkaline phosphatase. Mucosal folds and lumen of PVSMG has shown the weak activity of acidic phosphatase but the serosal limiting membrane has shown very weak activity.&nbsp;The succinic dehydrogenase activity was seen in the connective tissue septa of submucosal glandular cellular rods and the intense activity was observed at tunica muscularis.</div>