Cisternae Of Rough Endoplasmic Reticulum Research Articles

Chronic exposure to ethanol causes steatosis and inflammation in zebrafish liver

AIMTo evaluate the effects of chronic exposure to ethanol in the liver and the expression of inflammatory genes in zebrafish.METHODSZebrafish (n = 104), wild type, adult, male and female, were divided into two groups: Control and ethanol (0.05 v/v). The ethanol was directly added into water; tanks water were changed every two days and the ethanol replaced. The animals were fed twice a day with fish food until satiety. After two and four weeks of trial, livers were dissected, histological analysis (hematoxilin-eosin and Oil Red staining) and gene expression assessment of adiponectin, adiponectin receptor 2 (adipor2), sirtuin-1 (sirt-1), tumor necrosis factor-alpha (tnf-a), interleukin-1b (il-1b) and interleukin-10 (il-10) were performed. Ultrastructural evaluations were conducted at fourth week.RESULTSExposing zebrafish to 0.5% ethanol developed intense liver steatosis after four weeks, as demonstrated by oil red staining. In ethanol-treated animals, the main ultrastructural changes were related to cytoplasmic lipid particles and droplets, increased number of rough endoplasmic reticulum cisterns and glycogen particles. Between two and four weeks, hepatic mRNA expression of il-1b, sirt-1 and adipor2 were upregulated, indicating that ethanol triggered signaling molecules which are key elements in both hepatic inflammatory and protective responses. Adiponectin was not detected in the liver of animals exposed and not exposed to ethanol, and il-10 did not show significant difference.CONCLUSIONData suggest that inflammatory signaling and ultrastructural alterations play a significant role during hepatic steatosis in zebrafish chronically exposed to ethanol.

Ultrastructure Morphology of Camel Blood Cells

The main purpose of this study was to provide a basic cytology of camel blood by electron microscopy.Camel blood was collected, prepared, identified from two adult of one-humped female camels were clinically healthy. The fine structure of the red cells in camels was investigated and certain characteristic features were noted.The Scanning electron micrograph of camel erythrocytes showing elliptical shape and tropical waist (Tw) non-nucleated with 7.0±0.5 µm in diameter. The transmission of electron microscopy of camel erythrocytes showed elliptical shape and tropical waist (Tw), also a trilaminar of membranes (Me) of marginal band that a zone of high electron density. The area of (Me) showed structures are dense and the (Me) was contacted with individual microtubules (Mt). There are few intracellular organelles were observed with the occasional exception of number of mitochondria (Mi). The camel erythrocyte is trilaminar, the inner and outer membranes are of high electron density between which is a zone of lesser electron density. There are few intracellular organelles were observed with the occasional exception of number of mitochondria. The erythrocyte marginal band consisting of microtubules was observed.The fine structure of the camel monocytes showed revealed the presence of a few short cisternae of rough endoplasmic reticulum and various forms of vesicles associated with the Golgi complex were seen near the mitochondria, which are located adjacent to the main indentation in the nuclei. Membrane bound granules of different sizes and spherical or oval in shape, were observed, vacuoles of various forms, a well-defined Golgi complex, few rough endoplasmic reticulum and mitochondria were noticed randomly distributed in the cytoplasm.

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.

The monolayer–spheres–monolayer cycle: Ultrastructural changes in stem cells

Stem cell sphere formation is applied as a preconditioning treatment prior to transplantation. Here, stem cells (SC) isolated from human subepicardial adipose tissue were analyzed at different stages of the monolayer–spheres–monolayer cycle by transmission electron microscopy. Spheres obtained on a non-adherent surface or through hanging drops gave similar results. At the first two or three passages (stage 1), isolated SC displayed an embryonal cell-like ultrastructure. With increased passage number (stage 2), SC became larger and more electron-dense with a multilobed nucleus, well-developed rough endoplasmic reticulum (RER), well-developed Golgi apparatus, and numerous vacuoles. At 2 h after sphere induction (stage 3), SC gathered into clusters and formed desmosome-like intercellular contacts. Their nuclei possessed a large loose fibrillo-granular nucleolus, the cytoplasm was tightly packed with disintegrated cisternae of RER, and Golgi apparatus was not identified. Twenty-four hours afterward (stage 4), SC in well-formed spheres exhibited a large dense nucleolus and poorly developed Golgi apparatus and RER. One day after sphere dissociation (stage 5), SC looked like embryonal cells and were morphologically similar to the cells of the first stage except for the presence of a large nucleolus and several Golgi complexes. At 48 h after sphere dissociation (stage 6), SC became electron-dense and resembled SC of the second stage, bearing irregular nuclei and cytoplasm that was rich in RER. We interpret these results as SC senescence with increasing passage number after isolation from the tissue or 1 day after sphere dissociation and rejuvenation of the SC just after sphere dissociation. Further research is needed to determine the genetic, biochemical, and physiological parameters of the SC corresponding to morphologically defined distinct stages in order to provide high quality cellular material for cell therapy.

Histochemical Detection of Mannitol Oxidase in the Digestive Gland of Gastropods

Mannitol oxidase catalyses the oxidation of D-mannitol to produce the sugar mannose, releasing hydrogen peroxide. This enzyme was detected in the digestive gland and digestive tract of some herbivorous gastropods, suggesting a role in metabolization of mannitol contained in their foodstuff [1, 2, 3]. Mannitol is a 6 carbon polyalcohol present in algae, fungi and plants. Therefore, it seems that herbivorous gastropods get nutritional benefits from the ingestion of polyalcohols present in algae and plants due to enzymes that convert these compounds into sugars [1]. Cell fractionation studies revealed that in the digestive gland of terrestrial gastropods mannitol oxidase is associated with a special kind of tubules with a diameter of 40 nm [3]. But, so far, most studies about mannitol oxidase were performed with terrestrial gastropods. To extend existing knowledge, this enzyme was investigated in the digestive gland of the marine gastropods Aplysia depilans, Bulla striata, Siphonaria pectinata and Onchidella celtica, as well as in the garden snail Cornu aspersum (=Helix aspersa) and the land slug Lehmannia valentiana. For histochemical location of mannitol oxidase digestive gland samples were frozen in liquid nitrogen. Cryostat sections 12 μm thick on glass slides coated with APES were air dried for about 1 hour before being introduced in reaction medium. The reaction medium adapted from previously published methods [1] contained 0.5 mg/ml 3-3'-diaminobenzidine (DAB), 0.25 mg/ml horseradish peroxidase (50 U/ml) and 50 mM D-mannitol in 50 mM phosphate buffer pH 7.5. Control sections were incubated in medium without mannitol. Sections were incubated for about 2 hours at 30oC. Mannitol oxidase activity was also assessed by biochemical methods. For ultrastructural studies digestive gland samples were fixed with 2.5% glutaraldehyde and 4% formaldehyde in cacodylate buffer, postfixed with osmium tetroxide, dehydrated and embedded in Epon. In cryostat sections, digestive gland cells containing mannitol oxidase were stained brown due to DAB oxidation (Fig. 1 A-C). In control sections reaction was not observed in digestive gland cells (Fig. 1 D), but in other tissues unspecific reactions can occur. Biochemical assays also showed that all these six herbivorous species contain mannitol oxidase in the digestive gland. Enzyme activity was lower in B. striata and S. pectinata, being much higher in O. celtica and L. valentiana, and presented an intermediate value in the digestive gland of A. depilans and C. aspersum. The tubular structures typically associated with mannitol oxidase [3] were found in digestive gland cells of A. depilans, B. striata, C. aspersum and L. valentiana (Fig. 1 E-F). The tubules are located inside rough endoplasmic reticulum cisternae in A. depilans, while in B. striata, C. aspersum and L. valentiana they are found within smooth membrane cisternae (Fig. 1 E). On the other hand, in S. pectinata and O. celtica these tubules were not observed. Thus, at least in marine gastropods, mannitol oxidase is not always associated with intracisternal tubules even in species with a high mannitol oxidase activity such as O. celtica.

Sub-Cellular Damage of Hepatocytes Caused by Different Doses of Diclofenac Sodium in Rabbit

Diclofenac sodium is a potent analgesic and anti-inflammatory drug that is extensively prescribed in treatment of rheumatoid arthritis, postoperative pain, and chronic pain associated with cancer. The present study was designed to elucidate the qualitative and quantitative changes in rough endoplasmic reticulum of hepatocytes after recommended single, double and triple therapeutic dose of Diclofenac sodium in rabbits. The aim of study is to minimize the indiscriminate use of this drug in community and among physicians. Experimental study was carried at Dow University of Health Sciences (DUHS) and Sindh Institute of Urology and Transplantation (SIUT) from March 2009 to June 2010. Eighty eight healthy animals of three months age and 900~1000 gm body weight were isolated from the animal house of DUHS. These animals were divided into four groups categorized into Group A, Group B, Group C, Group D, each containing twenty two animals. Diclofenac sodium were administered intraperitoneally with the daily doses of 2, 4, and 6 mg/kg body weight for 14 consecutive days in Groups B, C and D while the control group (Group A) received normal saline. Animals were sacrificed on day fifteen and livers were removed and fixed in 4% gluterldehyde. They were processed for electron microscopy and examined under transmission electron microscope. Data was collected and subjected for statistical analysis a ‘P’ value less than 0.05 was taken as significant. It was observed that Diclofenac sodium produces significant changes in hepatocytes. There was de-granulation and swelling of the cisternae of Rough Endoplasmic Reticulum (RER) when the dose is doubled and these changes were highly significant when the dose is increased to three times the therapeutic.

Zonal Changes in the Ultrastructure of the Epididymal Principal cell of the Greater Cane Rat (Thryonomys swinderianus)

This study presents the varying ultrastructural characteristics of the principal cell along the different zones of the epididymis of the greater cane rat. Ten sexually mature male cane rats with known medical and reproductive history were perfusion-fixed using Karnovsky fixative (phosphate buffered 2% paraformaldehyde – 2.5% glutaraldehyde fixative at pH 7.4). Epididymal samples were then obtained, processed for ultrastructural analysis and examined under the transmission electron microscope. Our findings showed that the cane rat epididymis has four distinct regions – initial segment, caput, corpus and cauda epididymides. These regions are further subdivided into discrete subregional zones based on the cytological characteristics of the principal cell in each region. The principal cell in the proximal initial segment showed abundant rough endoplasmic reticulum and extensive Golgi apparatus arranged in a peculiar whorl shape predominantly in the apical cytoplasm with small vesicles, dense granules and multivesicular bodies scattered in and around the whorls. The principal cell of the distal initial segment is characterized by multivesicular bodies, small and coated vesicles as well as numerous flat and whorl-shaped cisternae of rough endoplasmic reticulum and dense-core mitochondria. In the caput epididymis, the principal cell contains more of lipid vacuoles, while in the corpus, it has prominent dense bodies of various sizes at its supranuclear area. These dense bodies tend to increase in the principal cells of the cauda epididymis. The transition between regions was however observed to be gradual with overlapping of morphological characteristics between two adjacent regions. These ultrastructural diversities exhibited by the epididymis along its length point to a corresponding functional diversity and do dictate the overall intra-luminal environment necessary for sperm maturation in the cane rat.

Ultrastructural Features of Eutopic Endometrium in a Rat Model of Endometriosis

Endometriosis is a chronic recurrent disease that is relatively common. Diagnosis is difficult and often delayed. Current treatments are inadequate with unacceptable side effects and multiple surgeries may be needed. Abnormal eutopic endometrium may play important role in endometriosis-associated infertility. This study aimed to examine the ultrastructural changes in eutopic endometrium in a rat model of surgically induced endometriosis. Endometrial tissue was removed from rats in surgical endometriosis induction group (n=10), sham operated (n=10) and non-operated control (n=10) groups in the diestrus phase of the estrus cycle. They were studied with light, transmission and scanning electron microscope as well as morphometric analysis. Eutopic endometrium in surgically induced endometriosis showed pseudostratified epithelium, vacuolated columnar cells alternated with dark cells. The stroma was edematous exhibiting dilated, congested blood vessels. The mean endometrial mucosal depth and surface epithelial height significantly increased. Ultrastructurally, most luminal epithelial cells showed vacuolation. Mucous secretory granules were surrounded by dilated rough endoplasmic reticulum cisternae. Mitochondria, glycogen deposits and vesicles with electron dense cores were observed. The nuclei were highly euchromatic. Well defined microvilli were noticed with evident apical tight junctions. Scanning electron microscope revealed flattened and structurless surface epithelium with apparent decrease in the number of pinopodes. A different response to sex hormones in different parts of eutopic endometrium was observed. Ultrastructural features of estrogen dominance or progesterone resistance in the eutopic endometrium might account for inappropriate cyclic changes occurring in the disease.

Correlative Light and Scanning Electron Microscopy for Observing the Three-Dimensional Ultrastructure of Membranous Cell Organelles in Relation to Their Molecular Components.

Although the osmium maceration method has been used to observe three-dimensional (3D) structures of membranous cell organelles with scanning electron microscopy (SEM), the use of osmium tetroxide for membrane fixation and the removal of cytosolic soluble proteins largely impairs the antigenicity of molecules in the specimens. In the present study, we developed a novel method to combine cryosectioning with the maceration method for correlative immunocytochemical analysis. We first immunocytochemically stained a semi-thin cryosection cut from a pituitary tissue block with a cryo-ultramicrotome, according to the Tokuyasu method, before preparing an osmium-macerated specimen from the remaining tissue block. Correlative microscopy was performed by observing the same area between the immunostained section and the adjacent face of the tissue block. Using this correlative method, we could accurately identify the gonadotropes of pituitary glands in various experimental conditions with SEM. At 4 weeks after castration, dilated cisternae of rough endoplasmic reticulum (RER) were distributed throughout the cytoplasm. On the other hand, an extremely dilated cisterna of the RER occupied the large region of the cytoplasm at 12 weeks after castration. This novel method has the potential to analyze the relationship between the distribution of functional molecules and the 3D ultrastructure in different composite tissues.

The effect of salivary gland extract of Lucilia sericata maggots on human dermal fibroblast proliferation within collagen/hyaluronan membrane in vitro: transmission electron microscopy study.

Lucilia sericata maggots are applied to chronic wounds to aid healing when conventional treatments have failed. After their application into a necrotic wound, they potentially influence wound healing with a combination of specific proteinases that are involved in the remodeling of extracellular matrix. These proteases cause changes in fibroblast adhesion and spread upon extracellular matrix protein surfaces, affecting integrity of the protein surfaces-especially fibronectin-while maintaining cell viability. This study focused on in vitro monitoring of the effect of homogenate substances prepared from maggot salivary gland of L sericata on the ultrastructure of human neonatal fibroblasts. Collagen/hyaluronan membrane was used as the synthetic substitute of extracellular matrix. The cultured human neonatal fibroblasts B-HNF-1 were seeded on the surface of the collagen/hyaluronan membrane and cultured with maggot salivary gland extract (SGE) at a concentration of 2.4 glands/1 mL. The authors observed increased cell metabolism and protein production (euchromatic nucleus, voluminous nuclear membrane, large reticular nuclei, distended and filled cisterns of rough endoplasmic reticulum, Golgi apparatus with saccules, and vesicles packed with fine fibrillar material) after incubating the cells in culture medium with SGE. The authors believe that increased cell metabolism and protein production corresponded with formation of microfibrillar net used for migration of fibroblasts in culture, but mainly for proper production of extracellular matrix. The authors suggest that their results may help explain the effect of SGE on wound healing and support implementation of maggot therapy into human medicine.

Structural differences in epiphyseal and physeal hypertrophic chondrocytes.

We have observed that epiphyseal and physeal hypertrophic chondrocytes in BALB/c mice show considerable differences of light microscopic and ultrastructural appearance, even when the cells are at the same stage of differentiation. In addition, cell structure maintenance improved with tissue preparation controlled for osmolarity and for membrane stabilization using 0.5% ruthenium hexammine trichloride (RHT) for both light microscopy (LM) and electron microscopy (EM) or 0.5% lanthanum nitrate for LM. Physeal hypertrophic chondrocytes showed a gradual increase in size closer to the metaphysis and a change in shape as cells elongated along the long axis. The nucleus remained central, with uniformly dispersed chromatin, and the rough endoplasmic reticulum (RER) was randomly dispersed throughout cytoplasm with little to no presence against the cell membrane. Even the lowermost cells showed thin elongated or dilated cisternae of RER and intact cell membranes. Epiphyseal chondrocytes remained circular to oval with no elongation. Nucleus and RER were positioned as a complete transcellular central nucleocytoplasmic column or as an incomplete bud with RER of the column/bud always continuous with RER peripherally against the intact cell membrane. RER was densely packed with parallel cisternae with adjacent cytoplasm empty of organelles but often filled with circular deposits of moderately electron-dense material consistent with fat. Optimal technique for LM involved fixation using glutaraldehyde (GA) 1.3%, paraformaldehyde (PFA) 1% and RHT 0.5% (mOsm 606) embedded in JB-4 plastic and stained with 0.5% toluidine blue. Optimal technique for EM used fixation with GA 1.3%, PFA 1%, RHT 0.5% and cacodylate buffer 0.03 M (mOsm 511) and post-fixation including 1% osmium tetroxide. These observations lead to the possibility that the same basic cell, the hypertrophic chondrocyte, has differing functional mechanisms at different regions of the developing bone.

Light and electron microscopic studies on the Y organ of the freshwater crab Travancoriana schirnerae

The fine structure of the premoult Y organ in the freshwater crab Travancoriana schirnerae revealed elliptical epithelial gland cells with large, eccentric, multinucleolated nuclei and ample cytoplasm. The cytoplasm showed numerous polymorphic mitochondria with tubular cristae, highly anastomosed tubules and vesicles of smooth endoplasmic reticulum (SER), rich free ribosomes, small amounts of cisternae of rough endoplasmic reticulum (RER), microtubules and was devoid of Golgi complexes. Mitochondria were of two types the more abundant micromitochondria with electron dense matrix and the less abundant macromitochondria with moderately dense matrix. The tubular SER was particularly concentrated towards the basal region of the cell, intermingled with mitochondria and dense patches of free ribosomes while the vesicular SER lie close to the lateral plasma membrane. Large vesicles with flocculent substances, a few electron dense granules and multivesicular bodies could also be noticed in the gland cell cytoplasm. Aggregations of microvesicles which appeared close to the lateral plasma membrane, in association with dilated SER cisternae and microtubules, possibly suggest the intercellular exchange of substances. The plasma membrane beneath the basal lamina was composed of invaginations and the apical surface possessed numerous microvilli which serve to increase the surface area for metabolic exchange. Towards the apical region, the lateral plasma membrane of adjacent cells was linked by tight junctions. The presence of extraordinarily abundant tubular SER, high proportion of mitochondria with tubular cristae and rich free ribosomes could well be elucidated in favour of steroid production by the gland cells.

The coagulating gland in the male greater cane rat (Thryonomys swinderianus): morphological and immunohistochemical features.

This study reveals the structure, ultrastructure and immunoexpression of oestrogen alpha and beta receptors (ERα and ERβ) in the coagulating glands of the greater cane rat. Gland samples from 15 adult male cane rats were processed for histological and ultrastructural studies while immunohistochemistry was also carried out. Coagulating gland in the cane rat is a paired, triangularly shaped, transparent gland weighing about 1 ± 0.48 g. Histologically, each secretory acinus is composed of folded mucosa surrounded by fibromuscular stroma. The simple columnar epithelium consists of principal cells at different stages of secretion evidenced by their apical blebs of various heights and occasional basal cells. Fine structure of the principal cells revealed the presence of apical blebs that contained secretory granules of varying electron-density, secretory vesicles and vacuoles on both their luminal surfaces and the lumen. While supranuclear cytoplasm contained Golgi apparatus with different cisternal arrangements, the infranuclear part is covered with dilated rough endoplasmic reticulum cisternae. Nuclei, apical bleb and stroma of secretory epithelium all showed positive immunostaining for ERα and ERβ. These findings revealed the prominence of apocrine secretion with no structural evidence of merocrine secretion and the uncommon ERα and ERβ distribution pattern in the coagulating gland of the cane rat.

Histological changes of the albino rat cerebellar cortex under the effect of different doses of tramadol administration

Background Tramadol hydrochloride is a centrally acting synthetic analgesic used to treat moderate to severe pain with a wide range of applications. Aim This study was designed to investigate the effect of tramadol on the histology of the cerebellar cortex in adult albino rats. Materials and methods Thirty adult male albino rats weighing about 200 g were used and divided into control and experimental groups. The latter group was subdivided into two subgroups (IIa and IIb). Rats of subgroup IIa and IIb were injected intraperitoneally with 0.7 and 1.8 mg as a single daily dose of tramadol solution for 2 weeks, respectively. Rats were killed after 2 weeks and decapitated. The cerebellum was removed and subjected to histological, immunohistochemical, and morphometric studies. Results Histological study of subgroup IIa showed mild distortion of Purkinje cells with destroyed mitochondria and cisternae of rough endoplasmic reticulum. Meanwhile, subgroup IIb showed Purkinje cells arranged in multilayer cells with obvious damage such as a small nucleus with an indented membrane. The granular layer contained small cells, most of which had lost their nuclei, whereas others showed condensed chromatin with a thin rim of cytoplasm. Results of inducible nitric oxide synthase reaction showed a moderately positive cytoplasmic reaction of granular and Purkinje cells in subgroup IIa. However, subgroup IIb showed a highly positive cytoplasmic reaction. Morphological study of the cerebellar layer thickness showed a significant decrease in the thickness of Purkinje and granular layers, with a significant increase in the thickness of the molecular layer in both experimental subgroups. The Purkinje cell count showed a significant decrease in its number in both experimental subgroups. Conclusion The results of this study provided evidence that tramadol intake exerts a neurotoxic effect on the cerebellar structure in an ascending manner according to the dose administered. Thus, the Ministry of Health should make efforts to control usage of this drug among teenagers and correct misconceptions about this medication.

English

The histology and ultrastructure of thyroid gland of White Fulani (Zebu) cattle were examined during the postnatal developmental period to show if variations in morphology exist with age and in relation to tropical climate. Eight prepubertal and ten pubertal cattle of abattoir origin were used to carry out this study. Histologically, the thyroid consisted of well-developed capsule, interlobular connective tissue, follicular and parafollicular cells from prepubertal to pubertal age of 5 to 7 years. The follicular cells were cuboidal in prepubertal period with some variations, became predominantly columnar in pubertal age of 2 to 4 years and highly flattened cells were common in the older pubertal animals of  5 to 7 years. The colloid was observed in the lumen at all age and was PAS-positive with abundant peripheral vacuoles in the pubertal age of 2 to 4 years. Significant variations (pË‚0.05) in structure of the thyroids were observed at all age and the follicular size and number of follicles increased as the cattle matured. Follicular height was reduced significantly in the older pubertal cattle of 5 to 7 years. Ultrastructurally, the follicular cells showed highly dilated cisternae of rough endoplasmic reticulum which decreased with age. Flattened follicular cells seen in the older pubertal cattle contained few cytoplasmic organelles and microvilli. Apically placed pseudopods and blebs were commonly observed in the pubertal age of 2 to 4 years. Lysosomal bodies increased with age of development. The parafollicular cells were encountered frequently in the prepubertal age than in the older cattle. They consisted of numerous dense secretory granules which increased in number with age. The present results suggest an optimum thyroid function during the pubertal. Our findings would be useful in interpreting changes in thyroid morphology during experimental and pathological conditions.   Key words:  Cattle, postnatal thyroid, histology, ultrastructure.

Ultrastructural effects of lead acetate on the spleen of rats

In this experiment, the ultrastructural effects of orally administered lead acetate on rat (Rattus rattus) spleen were studied. Rats weighing approximately 200-250 g were used in this experiment. They were divided into five groups, each one including five rats. Group I served as the normal control group while the others served as the experimental groups. The rats were exposed to oral administrations of lead acetate of 2.5 mg dissolved in 1 mL of drinking water per day. The administration lasted 96, 144, 336, and 432 h. The animals were anesthetized using chloroform inhalation and the peritoneum was stripped open and the spleen was removed and prepared for histological observation using a staining technique. Hypocellular white pulp, enlargement of venous sinusoids, clustering of heterochromatin in nucleus, vacuolation in the cytoplasm, swelling of mitochondria, and the distortion of rough endoplasmic reticulum cisterns were observed upon electron microscopic examination of the spleen tissue cells. These cytopathologic alterations indicate that lead acetate has some drastic toxicological effects on cellular structures.

Microstructure Features of Proventriculus and Ultrastructure of the Gastric Gland Cells in Chinese Taihe Black-bone Silky Fowl (Gallus gallus domesticus Brisson).

To investigate microstructure of proventriculus and ultrastructure of the gastric gland cells from Chinese Taihe black-bone silky fowl (BSF), the proventriculus of 4-week-old BSF was sampled. Conventional histological and transmission electron microscope (TEM) methods were used in this study. The wall of the Taihe BSF proventriculus was consisted of four layers, the mucous, submucosa, muscularis externa and the serosa as others birds. The muscularis externa of the birds' proventriculus contained three layers. Much of the melanin was present in loose connective tissue of lamina propria, submucosa, and muscularis externa unlike others. In addition, the ultrastructure of the gastric gland cells was observed by TEM. There was only one kind of gland cell, for example oxynticopeptic cell in proventriculus of Taihe BSF. The oxynticopeptic cells contained numerous mitochondria, cisternae of rough endoplasmic reticulum (CRER), intracellular canaliculi (IC) that secrete hydrochloric acid and small amounts of pepsinogen granules. The rough endoplasmic reticulum (RER) was irregular cisternae with ribosomes and surrounded tightly the mitochondria along their configuration. The electron-dense pepsinogen granules were round with various sizes. The neighbouring oxynticopeptic cells were closed up with tight junction and gap junction. The inter-space between the neighbouring oxynticopeptic cells was stenosis or was filled with electron-dense extracellular substance. In conclusion, the gastric gland cells of Chinese Taihe BSF proventriculus were only oxynticopeptic cells that secrete hydrochloric acid and pepsinogen, but no parietal cells and chief cells of mammal. The gastric gland cells of proventriculus were underdeveloped compared with those of mammals.

Differences in the defective alleles E and F for the locus CSN1S1 in goats affects the profile of milk caseins

The objective in the current study was to associate different genotypes for the gene that codifies the αS1-casein with the profile of milk caseins and the morphology of the mammary gland epithelial cells in goats. The genotypes HH, HF, EE and EF for the αS1-casein gene (H=any high allele) were assessed based on the differences in the size of fragments amplified using polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism (PCR-RFLP). The milk casein fractions were measured by reversed phase HPLC. Mammary gland biopsies of animals with each of these genotypes were submitted to histological and ultrastructural microscopy analysis for the evaluation of secretory epithelial cells. The amount of total casein in milk from goats with genotype HH was only higher than in milk from those animals with the genotype EF, while the αS1-casein (αS1-Cn) fraction was different among all genotypes. The largest αS1-Cn fraction was found in milk from the animals with the genotype HH, and it progressively decreased in milk from animals with the genotypes HF, EE and EF. Other milk casein fractions (β-casein, αS2-casein and κ-casein) had a characteristic composition for each genotype. The κ-casein (κ-Cn) fraction was greater whenever the F allele was found, and the β-casein fraction was greater in EE homozygous animals. The ultrastructural analysis showed that mammary gland secretory cells from goats with the genotype EE and EF have highly dilated rough endoplasmic reticulum (RER) cisternae, whereas the dilation pattern in the animals with the genotype HF was intermediate between those with the genotype HH, and EE/EF. Although the amount of αS1-casein is critical for an efficient transport of other caseins by RER, the defective F allele affects the other milk casein fractions differently from the defective E allele, probably due to the lack of phosphorylation sites on the protein encoded by the F allele, which would affect, in turn, the way caseins interact during milk micelle formation, reflecting on casein fractions in milk.

Ultrastructural characterization of in vivo-produced ovine morulae and blastocysts.

The ultrastructure of in vivo-produced ovine embryos, at the morula, early blastocyst and late blastocyst stages, was evaluated using transmission electron microscopy. Embryonic cells were characterized by the presence of intact intercellular junctions, numerous mitochondria, smooth endoplasmic reticulum cisternae and light vesicles. Polyribosomes, rough endoplasmic reticulum cisternae, secondary lysosomes, Golgi complexes and lipid droplets were also observed in the cytoplasm. The nucleus was well defined and organized, with an intact envelope rich in nuclear pore complexes, and one or more reticular nucleoli. Microvilli were present in external blastomeres of morulae and became more abundant in trophectoderm cells of early and late blastocysts. Light vesicles seemed to be associated with small cisternae of Golgi and endoplasmic reticulum origin. These cisternae fused and created light vesicles with engulfed heterogeneous cytosolic structures, small cisternae and vesicles. Their labile membrane enabled them to rapidly coalesce into medium-sized vesicles that began to engulf mitochondria and lipid droplets, forming giant vacuoles mostly filled with fat. Incomplete matured secretory vesicles were observed to exocytose into the perivitelline space of morulae, whereas fully matured secretory vesicles appeared only in trophectoderm cells, being exocytosed into the blastocoelic cavity. These observations suggested that these endoplasmic-/Golgi-derived vesicles behave as active autophagic organelles presenting probably a maturation process from compact morulae to blastocyst.

Redox imbalance and morphological changes in skin fibroblasts in typical Rett syndrome.

Evidence of oxidative stress has been reported in the blood of patients with Rett syndrome (RTT), a neurodevelopmental disorder mainly caused by mutations in the gene encoding the Methyl-CpG-binding protein 2. Little is known regarding the redox status in RTT cellular systems and its relationship with the morphological phenotype. In RTT patients (n = 16) we investigated four different oxidative stress markers, F2-Isoprostanes (F2-IsoPs), F4-Neuroprostanes (F4-NeuroPs), nonprotein bound iron (NPBI), and (4-HNE PAs), and glutathione in one of the most accessible cells, that is, skin fibroblasts, and searched for possible changes in cellular/intracellular structure and qualitative modifications of synthesized collagen. Significantly increased F4-NeuroPs (12-folds), F2-IsoPs (7.5-folds) NPBI (2.3-folds), 4-HNE PAs (1.48-folds), and GSSG (1.44-folds) were detected, with significantly decreased GSH (−43.6%) and GSH/GSSG ratio (−3.05 folds). A marked dilation of the rough endoplasmic reticulum cisternae, associated with several cytoplasmic multilamellar bodies, was detectable in RTT fibroblasts. Colocalization of collagen I and collagen III, as well as the percentage of type I collagen as derived by semiquantitative immunofluorescence staining analyses, appears to be significantly reduced in RTT cells. Our findings indicate the presence of a redox imbalance and previously unrecognized morphological skin fibroblast abnormalities in RTT patients.