Electron-dense Secretory Granules Research Articles

Sublethal Effects Induced by a Cyflumetofen Formulation on Honeybee Apis mellifera L. Workers: Assessment of Midgut, Hypopharyngeal Glands, and Fat Body Integrity.

Worldwide, both cultivated and wild plants are pollinated by the honey bee, Apis mellifera. Bee numbers are declining as a result of a variety of factors, including increased pesticide use. Cyflumetofen controls pest mites in some plantations pollinated by bees, which may be contaminated with residual sublethal concentrations of this pesticide, in nectar and pollen. We evaluated the effects of a sublethal concentration of a cyflumetofen formulation on the midgut, hypopharyngeal gland, and fat body of A. mellifera workers orally exposed for 72 h or 10 days. The midgut epithelium of treated bees presented digestive cells with cytoplasm vacuoles and some cell fragmentation, indicating autophagy and cell death. After being exposed to the cyflumetofen formulation for 72 h, the midgut showed a higher injury rate than the control bees, but after 10 days, the organs had recovered. In the hypopharyngeal gland of treated bees, the end apparatus was filled with secretion, suggesting that the acaricide interferes with the secretory regulation of this gland. Histochemical tests revealed differences in the treated bees in both exposure periods in the midgut and hypopharyngeal glands. The acaricide caused cytotoxic effects on the midgut digestive cells, with apical protrusions, plasma membrane rupture, and several vacuoles in the cytoplasm, features of cell degeneration. In the hypopharyngeal glands of the treated bees, the secretory cells presented small electron-dense and large electron-lucent secretory granules. The fat body cells had no changes in comparison with the control bees. In conclusion, the cyflumetofen formulation at sublethal concentrations causes damage to the midgut and the hypopharyngeal glands of honey bee, which may compromise the functions of these organs and colony fitness. Environ Toxicol Chem 2024;00:1-11. © 2024 SETAC.

Histology, histochemistry and fine structure of the lacrimal gland in the one-humped camel (Camelus dromedarius).

Our research aimed to provide complete histological, histochemical and ultrastructural features of the lacrimal gland of the one-humped camel (Camelus dromedarius) as well as novel insights into its adaptability to the Egyptian desert. Our study was applied to 20 fresh lacrimal glands collected from 10 camels instantly after their slaughtering. The results revealed that the gland was a compound tubulo-acinar gland, and its acini were enclosed by a thick connective tissue capsule that was very rich in elastic and collagen fibres. The gland acini had irregular lumens and were composed of conical to pyramidal cells. The nuclei of secretory cells were found in the basal part, and the cytoplasm was eosinophilic and granular. The glandular tissue consisted of serous and mucous acini and seromucous secretory cells. Histochemically, there was a significant amount of neutral mucopolysaccharides in the acini in which mucous cells had a significant periodic acid-Schiff (PAS)-positive reaction, whereas seromucous cells had a mild PAS-positive reaction. Ultrastructurally, the lacrimal cells had numerous secretory vesicles with contents of moderately to highly electron-dense cytoplasm. The nuclear envelope consisted of two prominent membranes surrounding the peri-nuclear cisterna. The acinar cells had numerous electron-lucent and moderately electron-dense secretory granules, mainly situated on the apical surface, and secreted their contents into the lumen. The luminal surface of the mucous secretory cells represents the remains of secretory granules discharged by the merocrine mechanism. In conclusion, the mucous secretion is believed to aid in the washing and moistening of the eyeball, particularly in dry, hot and dusty environments.

Ultra-structural organization of the gallbladder mucous membrane of Anglo-Nubian goat.

Currently, studies devoted to establish the anatomical and histological patterns of the internal organs organization in animals depending on their species and breed, as well as conditions of detention are the most relevant. The liver morphology in representatives of the ruminant family has not been sufficiently studied. Questions regarding the micro- and ultra-structural organizations of the gallbladder wall remain open. The aim of the study was to establish the ultra-structural organization features of the gallbladder mucous membrane of an Anglo-Nubian goat. The material for the study was the gallbladder wall's fragments of an adult Anglo-Nubian goat. Further processing of the obtained samples was carried out to acquire histological preparations. Ultra-thin sections were photographed in a Jem-1011 electron microscope at magnifications of 2,500 - 3,000. It was found that the gallbladder mucous membrane of an Anglo-Nubian goat is formed by the epithelial layer and its own lamina. The epithelial layer is represented by a single-layer prismatic epithelium. The nuclei are light, with clear contours. The apical surface of epithelial cells forms microvilli and the cytoplasm of the apical pole of cells contains many electron-dense secretory granules. The lateral surfaces of the cells in their apical part are interconnected by tight contacts. The lamina propria is formed by loose connective tissue containing many blood vessels and nerve fibers. Referring to the scientific literature describing possible pathologies of the gallbladder, we can conclude that the picture presented in the results generally corresponds to the position of the gallbladder without pathologies.

The ultrastructural features of the infundibulum of the green iguana, Iguana iguana.

The purpose of this study is to describe, in detail, the ultrastructure of the infundibulum of the sexually mature and active female green iguana, Iguana iguana. The infundibulum of five iguanas was remarkably distinct from the uterus, and was also clearly demarcated into cranial (expanded v-shaped) and caudal (tubular) divisions. Tissue samples obtained from five portions (three from the cranial division and two from the caudal division) of the infundibulum were processed conventionally for light and electron microscopy. The epithelial lining of the most anterior, middle, and posterior, parts of the cranial division displayed nonciliated cells predominantly, and occasionally ciliated cells. The numerous secretory granules in nonciliated type 1 cell found in the fimbrial aspect of the infundibulum were homogenous and deeply electron-dense, but those in the other two regions were variants of this cell type because they contained variably electron-dense secretory granules. Two main types of nonciliated cells (type 2 and its variant, type 3, as well as type 4) occurred in the epithelial lining of the caudal division of the infundibulum, but they, clearly, showed no dense secretory granules. Whereas the nonciliated type 2 cell and its variant (type 3 cell) contained large glycogen deposits, the type 4 cell lacked these deposits but its apical part contained large lipid-like droplets and, remarkably, blebbed into the duct lumen. The nonciliated cells lining the mucosal tubular glands contained highly electron-dense secretory granules, which were similar to those found in the nonciliated type 1 cell in the epithelial lining of the fimbrial part of the cranial division of the infundibulum.

Functional Morphology and Development of the Colleterial Glands in Non- and Egg-Laying Females of the Pest Termite Coptotermes gestroi (Blattaria, Isoptera, Rhinotermitidae).

Colleterial glands of female insects are accessory glands responsible for producing secretions associated with egg-laying. Within Dictyoptera, they synthesize compounds of the ootheca. However, their morphology and role in termites are poorly understood. Here, we compared the morphology, development, and secretory activity of the colleterial glands between non- and egg-laying females of the pest termite Coptotermes gestroi under light and transmission electron microscopy. We also provide the first description of these glands for Rhinotermitidae. The glands are paired, divided into anterior and posterior units, which join in a common duct via basal trunks. They are highly developed within egg-laying females, especially the posterior gland, secreting glycoproteins to lubricate the genital chamber and/or stick the eggs together. Ultrastructure revealed glandular epithelia composed of bicellular units of Class 3, whose secretory activity varied between groups and units. Posterior gland of egg-laying females showed richness of mitochondria, rough endoplasmic reticulum, and secretory vesicles, including electron-dense secretory granules, indicating synthesis and transport of contents, especially proteins. The basal trunks were enfolded by muscles, supporting their role in conducting secretion. Morphophysiological modifications occur in the colleterial glands as females mature and lay eggs, and the mechanisms underlying the secretory cycle of the glands are discussed.

Light and Electron Microscopy of Buccal Salivary Glands of the Dromedary Camel

The study was aimed to investigate the light and electron microscopic structure of buccal salivary glands in the dromedary (Camelus dromedarius). Anatomically, the dromedary camel buccal glands were well-developed and were located on the lateral side of the cheek. Three parts (groups) of the buccal glands could be observed: dorsal, middle and ventral parts. Histologically, the secretory units were tubule-acinar, surrounded by myo-epithelial cells and supported by connective tissue. Whereas, the dorsal glands were purely mucous and the ventral glands were purely serous in secretion, the middle ones were muco-serous with predominant mucous cells. Ultra-structurally, the glandular cells of the serous secretory units (type I cells) contained numerous microvilli, many electron-dense secretory granules, abundant rough endoplasmic reticulum and mitochondria. On the other hand, the mucous-secreting cells (type II cells) appeared with numerous electron-translucent supra-nuclear granules and flat basal nuclei; dilated tubules of rough endoplasmic reticulum; fewer mitochondria and Golgi bodies were also observed. The obtained results have been compared with the previous reports on salivary glands of camel and other mammalian species.

Morphology and seasonality of the sexual segment of the kidney in genus Bothrops snakes.

In Squamata, the sexual segment of the male kidney (SSK) produces secretory granules that are transmitted to the female tract during copulation. Here, we investigate the morphology of SSK in various species of the pitviper-genus Bothrops, a medically relevant clade of Neotropical snakes, using histology, histochemistry, as well as scanning and transmission electron microscopy. We also evaluated the relationship of SSK hypertrophy with spermatogenesis and storage of sperm. The SSK in Bothrops consists of tall columnar epithelial cells filled with electron-dense secretory granules. These granules are apparently released into the lumen by an apocrine secretory process. In general, the ultrastructural morphology of SSK in Bothrops is similar to those described for other pitvipers in the genus Agkistrodon. In most Bothrops males, the SSK produces carbohydrates and proteins, and occurs in all lobes of the kidney, occupying most of the kidney mass. In contrast, intersexual females (with male copulatory organs) of Bothrops insularis had a smaller SSK diameter than males and did not show hypertrophy. The seasonal development of SSK in Bothrops species seems to be driven by environmental factors rather than phylogeny, since sister species exhibited periods of hypertrophy at different months. In most Bothrops males, hypertrophy occurs at various seasons of the year (spring, summer, autumn), even in winter, and seasonal changes in SSK do not necessarily accompany spermatogenesis.

Ultrastructural study of the lacrimal glands in severe dry eye disease following Stevens-Johnson syndrome

PurposeThis study aimed to examine the ultrastructural features of the lacrimal glands of patients with severe dry eye due to Stevens-Johnson syndrome (SJS). MethodsBiopsies form orbital lobes of six lacrimal glands obtained from fresh body donors (n=3) and patients with SJS (n=3; absolute tear deficiency; 2-6 months of disease duration) were examined using transmission electron microscopy (TEM). ResultsOn TEM, normal lacrimal glandular tissue shows columnar acinar epithelial cells containing basally located rounded or oval euchromatic nuclei with cytoplasmic electron dense and ­moderately electron-dense secretory granules. Histologically, the lacrimal gland biopsies showed varied degree of acinar atrophy with lymphocytic infiltration in SJS patients. While on TEM, the lacrimal glands in SJS patients showed homogenous appearance of the nuclear chromatin of acinar cells with no differentiation into hetero-or euchromatin and loss of nucleoli. The cytoplasm lacked any electron dense material and showed significant loss of endoplasmic reticulum, mitochondria and Golgi bodies. The myoepithelial cells shared similar characteristics as in acinar epithelial cells along with loss of spindle shaped processes. ConclusionTransmission electron microscopy revealed ultrastructural changes in terms of nuclear composition, secretory vesicles, lysosomal vacuolation and myoepithelial cell distribution in the lacrimal glands of SJS patients.

P36.01 Primary Acinic Cell Carcinoma of Bronchial Ground Origin: A Case Report

Primary acinic cell carcinoma of the lung is an extremely rare disease. Also known as Fechner’s tumor, this condition was first reported by Fechner et al. in 1972. The accurate diagnosis of primary pulmonary acinic cell carcinoma is difficult and relies on comprehensive evaluation of clinical, histological and immunohistochemical features. A 49-year-old male patient was referred to our hospital because of an abnormal infiltration shadow in the left lower lung field detected on a chest radiograph during a medical check-up. Chest computed tomography revealed a nodal mass shadow 10mm in size, in segment 8 of the left lower lobe. Bronchoscopic examination revealed a polypoid tumor at B8. Transbronchial biopsy was performed and the tumor was diagnosed as a bronchial gland adenoma. The patient underwent video-assisted thoracic segmentectomy to achieve complete resection of the tumor. Macroscopically, the tumor was a solitary mass measuring 14×10×8 mm in size with substantial cut surface and showed no intraparenchimal growth. Histopathological examination revealed a polypoid projection in the bronchial space. Adeno-type cancer cells with monomorphous nuclei invade the bronchial wall tissue in association with tubule or acinus-like space formation. The cytoplasm of the tumor cells is plump and eosinophilic with granularity or clear. No direct invasion into the lung parenchyma was observed. Immunohistochemical staining revealed that the tumor cells were positive for PAS, lactoferrin, and HMG-45MI. The features are consistent with acinic cell carcinoma of bronchial gland origin. Electron microscopy showed that the acinus-forming tumor cell possess well-developed mitochondria and round-surfaced endoplasmic reticulum, in association with active luminal secretion. Rounded, electron-dense secretory exocrine granules, ranging from 150 to 340 nm in size, are noted mainly in the apical cytoplasm. Fat vacuoles are noted in some tumor cells. Microvillous intracytoplasmic lumina are occasionally noted. Bundles of intermediate filaments and desmosomal attachments are also seen. These features are consistent with acinar cell nature of the cells. Fourteen years since the surgical resection, no apparent recurrence or metastasis has been detected. We experienced an extremely rare case of primary bronchial acinic cell carcinoma diagnosed based on clinical information, histopathological features, immunogistopathological staining profile, and electron microscopy features. The limited number of reports on this type of tumor have revealed that the outcome after surgical resection is favorable due to its low-grade malignant potential. Likewise in this case, the patient remained free of recurrence for over 14 years after surgery.

Histological, transmission electron microscopic, and immunohistochemical study of the adrenal gland in the Persian squirrel (Sciurus anomalus).

This research was aimed to present the histological and ultrastructure properties of the adrenal gland in the Persian squirrel. Two male and female animals were included in the study. The adrenal gland was bean-shaped and located on the cranial pole of kidney. The enveloping capsule was dense connective tissue that reacted positively with Periodic-Acid Schiff (PAS) and Masson trichrome stainings. The parenchyma of the gland consisted of two-part, namely cortex and medulla; the cortex had three layers: zona glomerulosa (ZG), zona fasciculata (ZF), and zona reticularis (ZR). The cells of the ZG were mainly spherical and ovoid with circular arrangement and few lipid droplets in TEM micrographs. The cells of the ZF were columnar and spherical that were arranged in cord-like rows. Transmission electron microscopy (TEM) indicated conspicuous lipid droplets and mitochondria in this zone. The cells of the ZR were arranged in a tangled networks and were almost similar to those in the ZF. TEM images showed fewer lipid vesicles in the ZR compared to the ZF and ZG. Chromaffin cells were located in the medulla of the adrenal gland in two layers. TEM images showed that some of them were smaller and contained fewer secretory granules; other cells were larger and contained more electron-dense secretory granules. Immunofluorescence staining showed that steroidogenic factor 1 (SF1) expressed from cortex to the corticomedullary junction (CMJ) and tyrosine hydroxylase (TH) expressed in the medulla. In conclusion, the results indicated both similarities and differences between the adrenal gland of the Persian squirrel and other animals such as mammals and rodents.

Crop Morpho-Histological Peculiarities in Domesticated Pigeons (Columba livia domestica), Cattle Egret (Bubulcus ibis) and Domesticated Ducks (Anas platyrhynchos domestica)

The crop architecture varies among different avian species consistent with their feeding habits. Therefore, twenty-one of mature healthy male pigeons (granivorous), cattle egrets (carnivorous), and ducks (omnivorous), seven per species, were utilized for the histological, immunohistochemical, and ultrastructural analyses. Histologically, the mucosal folds were covered by non-keratinized stratified squamous epithelium in the three investigated species. The mucosal glands are only peculiar to the crops of the cattle egrets as well as the ducks, while the pigeons' crops were devoid of any secretory units. Morphometrically, the optical densities of the Alcian blue (AB) and periodic acid Schiff (PAS) reactions in the secretory glands, the area % of collagen fibers, the thickness of the tunica musculosa were measured and declared significant differences among the three studied avian species. Immunohistochemical reaction revealed ki-67 immuno-positive reactivity in the nuclei of basal cell layers of the crop epithelium in pigeons only. Regarding ultrastructure investigation, the covering epithelium of all studied species had been shown to be the basal layer of cuboidal to tall columnar cells with desmosomal junctions at the level of their cellular interdigitation, intermediate layers of large irregular polygonal cells with obviously increased cytokeratin filaments especially in the ducks and cellular interdigitation in between. The superficial layer of flat-shaped cells in the three investigated species manifested by desmosomal junctions in between but at the level of the surface squamous cells of the superficial layer, a fine lateral process is only inspected in the pigeons. In conclusion, the crop glands characterized by supranuclear electron dense secretory granules in the cattle egrets and electron-lucent in ducks.

The Protective Role of Parsley extract on Carbimazole Induced Histopathological Alterations in The Exocrine Pancreas of Adult Male Albino Rat.

Abstract:Introduction: Carbimazole is used in the treatment of hyperthyroidism. Parsley is a common herb used in various types of industries such as food, cosmetics, and pharmaceuticals.Aim of the study: The current experiment is aimed to assess the harmful effect of carbimazole on the exocrine part of the pancreas of adult male albino rats and to analyze the protective role of parsley extract. Material and methods: twenty-eight rats were used and divided equally into control group, parsley group that was administered 1 ml of parsley extract /150 g/day for 8 weeks, carbimazole group that was treated with 1.35 mg of carbimazole/Kg/day for 8 weeks, and carbimazole and parsley extract-treated group that received both carbimazole and parsley extract in the same doses and durations as the previous groups. The pancreatic specimens were dissected out and prepared for light and electron microscopic examination.Results: Carbimazole induced clear histopathological alterations in the rat pancreas compared to the control group. There was degeneration in the epithelial cells of pancreatic acini with cytoplasmic vacuolation and a marked decrease in apical acidophilia. Widening in the intercellular space with mononuclear cellular infiltration and blood vessel congestion were also noticed. Morphological analysis showed a significant increase in collagen fibers in-between the pancreatic acini, around the blood vessels, and the interlobular ducts. Ultrastructure analysis also revealed dilatation in the rough endoplasmic reticulum, ballooning mitochondria with disturbed cristae as well as less electron-dense secretory granules. However, carbimazole and parsley extract co-treated showed major improvement in the histology and ultrastructure of pancreatic tissue.In conclusion: the results verified the protective role of parsley against the toxic effect of carbimazole which could belong to the antioxidant properties of parsley.KeywordsCarbimazole; Pancreas; Histopathology; Parsley; ultrastructure

Ultrastructure of the prosomal gland complex in unfed larvae of the fresh-water mite Limnesia maculata (Müller, 1776) (Acariformes, Limnesiidae)

The salivary and coxal glands in unfed larvae of the fresh-water mite Limnesia maculata (Müller, 1776) (Acariformes, Limnesiidae) were studied using light and electron microscopy. Three pairs of the salivary and one pair of the coxal glands constitute the prosomal gland complex. The salivary glands pertain to simple alveolar glands consisting of the single acinus with prismatic cells arranged around the intra-alveolar lumen. Owing to their spatial distribution, the salivary glands may be termed as medial, ventral and lateral. While the ventral and lateral glands are arranged symmetrically, the medial glands are disposed one after another at the frontal wall of the synganglion (brain). The medial and the ventral glands possess mostly electron-dense secretory granules supposedly of protein nature. The lateral glands show variable organization mainly having electron-lucent vacuoles. No well pronounced rough endoplasmic reticulum and Golgi bodies were discernible in the salivary glands. The coxal glands are well developed and composed of (i) the main portion (the so-called labyrinth) including at least two tightly opposed loops and extending backward along the brain, and (ii) the very short anterior portion/end piece transforming anteriorly into the terminal sac/bladder. The cells of the main portion are provided with apical microvilli, whereas the basal infolding/basal labyrinth is lacking. The cells of the anterior portion do not show the apical microvilli and the basal infoldings. The terminal sac is lined by a cuticle and has an ectodermal origin. The ducts of the salivary glands come together at the dorsal aspect of the bladder, to which they open forming the common podocephalic duct anteriorly. The latter opens on each side into the subcheliceral space. The well-developed podocephalic system suggests its active role in the living processes such as feeding and ion-water balance.

Juvenile recurrent parotitis: Soft foods contribute to the delayed development of salivary glands.

Juvenile recurrent parotitis (JRP) is the second-most common childhood disease of the salivary glands after mumps. Since popularisation of mumps vaccination, children suffered from JRP more often, and the aetiology remains unclear. Chinese children had the habit of soft foods due to the special dietary habit of Asia. To clarify whether mastication was related to the pathogenesis of JRP and whether the growth of salivary glands was influenced by soft diet. Investigation of dietary habit and masticatory efficiency from 2015 to 2018 of children diagnosed with JRP compared with the normal children by the dentition. Mice had been fed a soft diet beginning in their development phase. The gland weight, amount of saliva, salivary amylase, histological and ultrastructural observation and the expression levels of EGF, FGFr2 and Wnt3a had been tested. The JRP children preferred soft foods and had a significantly lower masticatory efficiency than do normal children. When normalised by body weight, the gland weight, amount of saliva and amount of salivary amylase in the experimental group were significantly lower. The ultrastructural results showed that the acinar cells in the experimental groups were smaller and contained fewer electron-dense secretory granules than those in the control groups. The expression levels of EGF, FGFr2 and Wnt3a in the salivary glands of mice in the experimental groups were significantly lower than those of mice in the control groups. The soft diet indeed influenced the salivary gland through insufficient mastication, which could be one of the primary factors inducing JRP.

The structural and chemical basis of temporary adhesion in the sea star Asterina gibbosa.

Background: Marine biological adhesives are a promising source of inspiration for biomedical and industrial applications. Nevertheless, natural adhesives and especially temporary adhesion systems are mostly unexplored. Sea stars are able to repeatedly attach and detach their hydraulic tube feet. This ability is based on a duo-gland system and, upon detachment, the adhesive material stays behind on the substrate as a 'footprint'. In recent years, characterization of sea star temporary adhesion has been focussed on the forcipulatid species Asterias rubens.Results: We investigated the temporary adhesion system in the distantly related valvatid species Asterina gibbosa. The morphology of tube feet was described using histological sections, transmission-, and scanning electron microscopy. Ultrastructural investigations revealed two adhesive gland cell types that both form electron-dense secretory granules with a more lucid outer rim and one de-adhesive gland cell type with homogenous granules. The footprints comprised a meshwork on top of a thin layer. This topography was consistently observed using various methods like scanning electron microscopy, 3D confocal interference microscopy, atomic force microscopy, and light microscopy with crystal violet staining. Additionally, we tested 24 commercially available lectins and two antibodies for their ability to label the adhesive epidermis and footprints. Out of 15 lectins labelling structures in the area of the duo-gland adhesive system, only one also labelled footprints indicating the presence of glycoconjugates with α-linked mannose in the secreted material.Conclusion: Despite the distant relationship between the two sea star species, the morphology of tube feet and topography of footprints in A. gibbosa shared many features with the previously described findings in A. rubens. These similarities might be due to the adaptation to a benthic life on rocky intertidal areas. Lectin- and immuno-labelling indicated similarities but also some differences in adhesive composition between the two species. Further research on the temporary adhesive of A. gibbosa will allow the identification of conserved motifs in sea star adhesion and might facilitate the development of biomimetic, reversible glues.

Comparative histomorphological and ultrastructural study of the luminal epithelium of the isthmus in laying and moulting domestic fowls (Gallus domesticus).

This study describes ciliated, nonciliated and mitochondrial luminal epithelial cells of the isthmus in laying and moulting domestic fowls using histological and ultrastructural techniques. The ciliated cells were nonsecretory, while numerous electron-dense secretory granules were present in the nonciliated cells of laying birds. Mitochondrial cells, occurring in two morphologically distinct forms, constituted the third type of epithelial cell present in the isthmus. The SEM study showed that the luminal epithelium was dominated by ciliated cells, the cilia of which partially obscured adjacent nonciliated cells. The involution of the luminal epithelium in moulting birds occurred via autophagy, apoptosis and necrosis. Autophagic inclusions, which included autophagosomes and autolysosomes, were present in the early degenerative phases of ciliated, nonciliated and mitochondrial cells. Nonciliated cells underwent degeneration via apoptosis, which was characterized by nuclear and cytoplasmic condensation. Apoptotic and necrotic ciliated cells were evident during the intermediate and advanced stages of regression. The presence of apoptotic cell death was confirmed using the TUNEL assay. Loss of cilia via the formation of cilia packets was observed using TEM and SEM. Necrotic cell death occurred in mitochondrial cells during the intermediate and late stages of degeneration. In conclusion, the findings of the study on isthmus involution in moulting birds suggest that autophagy is a process confined to the early stages of degeneration, while apoptosis and/or necrosis occur in the terminal stages of regression.

Histological, Histochemical and Ultrastructure Studies on the Ostrich Pancreas (Struthio camelus)

This work aimed to discuss the histological, histochemical and ultrastructure of the ostrich pancreas. Specimens were collected from eight adult apparent healthy male ostriches. The specimens immediately immersed in 10 % neutral buffered formalin and Bouin,s solution. Tissue sections were prepared and stained for further examination. The histological examination demonstrated that the ostrich pancreas surrounded by a thick connective tissue capsule which gave septa to the parenchyma and divided it into numerous pancreatic lobules. The parenchyma composed of exocrine and endocrine parts. The exocrine part formed by acini, the acinar cell was large pyramidal, with a large rounded vesicular nucleus. Its apical part had fine deeply stained zymogenic granules. The endocrine portion was formed by beta, alpha and mixed islets. Ultrastructurally, the acinar cells forming the pancreatic acini appeared pyramidal having a basally large vesicular nucleus with large spherical and electron dense nucleoli. Its zymogene granules were spherical and electron dense. The beta cells were large ovoid or polygonal contained electron dense secretory granules with the presence of halo zoon between its limited membrane and the content. Alpha cells are elongated or polygonal contain electron dense spherical secretory granules with ill distinct space between the limited membrane and its content. Delta cells appeared oval or triangular having spherical electron dense granules its limited membrane closely adhere to its content. There were a different histochemical reaction to acid phosphatase, alkaline phosphatase, ATPase and succinic dehydrogenase in the acinar cells and in the pancreatic islets.

Histocytological and histochemical features of the adrenal gland of Adult Egyptian native breeds of chicken (Gallus Gallus domesticus)

BackgroundAvian adrenal gland is one of the most important endocrine glands as it regulates several vital physiological functions. Removal of such gland leads to death of bird. ObjectiveThe present investigation aims to illustrate morphological, histocytological and histochemical features of adrenal gland of Adult Egyptian native breeds of Chicken (Gallus gallus domesticus) by means of gross anatomy, light and transmission electron microscope. Materials and methodsThirty chickens of 6months old were collected from Beni-Suef province, Egypt. Immediately after sacrifying the birds, right and left adrenals were subjected to histomorphological, histochemical and ultrastructural examinations. ResultsGrossly, the adrenal glands were situated cranio-medially to the kidneys with yellowish color. Histologically, they were ensheathed with thin collagenous connective tissue capsule containing many blood vessels and associated with numerous autonomic ganglia. The parenchyma was composed of mixture of cortical and medullary tissues as well as numerous blood sinusoids. The cortical tissues were demarcated in two distinct zones; subcapsular and inner. The cells of subcapsular cortical zone (SCZ) contained more lipid droplets and less mitochondria than the inner cortical cells do. Two types of chromaffin cells were distinguished; epinephrine (E-) and norepinephrine (NE-) producing cells. The former contained spherical moderate electron-dense secretory granules. The latter contained abundant pleomorphic intensely electron-dense secretory granules. ConclusionHigher cortical tissues on the expense of medullary ones may be the need for increased production of adrenal cortical hormones (glucocorticoids and mineralocorticoids) in the chicken that lives in areas which water conservation is important.

The Emerging Picture of Mast Cell Activation: The Complex Regulatory Network of High-Affinity Receptor for Immunoglobulin E Signaling.

It is now well known that immunoglobulin E (IgE) and mast cells (MCs) are important participants in allergic diseases. MCs contain electron-dense secretory granules which are filled with inflammatory mediators. The interaction of an allergen (antigen) with an antigen-specific IgE-bound high-affinity receptor for IgE (FcεRI) is an essential step in MC activation as well as subsequent downstream signaling events. What we know is that IgE and FcεRI activate a complex regulatory network (i.e., signaling molecules and messengers) that governs both the type of MC activation and the symptoms of allergic disease. This review focuses on recent discoveries that shed new light on FcεRI signaling networks, holding promise for the development of new therapeutic solutions in the treatment of allergic diseases.

Dermal glands in freshwater mites Limnesia undulata (O.F. Müller, 1776) and Limnesia fulgida (C.L. Koch, 1836) (Acariformes, Limnesiidae)

Dermal glands in the water mites Limnesia undulata (O.F. Müller, 1776) and Limnesia fulgida (C.L. Koch, 1836) and their secretion were studied by means of light microscopical, transmission electron microscopical (TEM) and scanning electron microscopical (SEM) methods. These mites possess two types of dermal glands – the ‘common’ dermal glands in a number of 14 pairs and one pair of the so-called ‘idiosomal’ dermal glands. The common dermal glands are bi-lobed organs and consist of high prismatic secretory cells directed to the gland mouth and mostly replacing the intra-alveolar lumen. The cells contain numerous cisterns of rough endoplasmic reticulum (RER) and specifically organized Golgi bodies (GB) producing electron-dense elongated secretory granules. These granules are released from the cells via apocrine secretion and come to the gland mouth, where they are sometimes accompanied by secretory cell cytoplasm. The final secretion may show a fibrous character. The idiosomal glands are sac-like organs stretched along the ventral body wall in posterior direction from the gland orifice corresponding to the epimeroglandularia 4. The secretory epithelium leaves a large intra-alveolar lumen filled with an electron-dense secretory material. Golgi bodies are organized identically with those in the common glands, which indicates the general homology of these two types of dermal glands. The glands' orifices are organized similarly in all glands and possess an internal funnel-shaped sclerite with muscle armament, an internal valve, medial epicuticular flaps and an external circular cuticular ring. All glandularia, except for E4 and V1, are accompanied with a long and thin sensitive seta. During fixation, secretion of the common dermal glands is extruded to the exterior in the form of large amounts of convoluted tube-like structures. In the living organisms, being secreted in mass from the glands, this secretion acquires the form of long rigid mostly hollow un-branched threads comparable with the similar silken threads of other water arthropods. The function of the idiosomal glands secretion still remains unknown.