Cisternae Of Rough Endoplasmic Reticulum Research Articles

Effect of acute pentylenetetrazol injection induced epileptic seizures on rat dentate gyrus at different postnatal ages.

Epilepsy is one of the most common neurological disorders, its prevalence approximately from 0.5% to 2% of the general population. Generalized seizures could lead to several morphological changes in the brain. This study aimed to investigate the morphological effects of a single convulsive dose of pentylenetetrazol (PTZ) on rat dentate gyrus at different postnatal ages. Thirty-six male Wistar rats were used at the following postnatal ages: P10, P21, and P90 (12 rats per each age). The animals in each age were equally divided into two groups: group I, control and group II, treated with a single intraperitoneal injection of PTZ (55 mg/kg). After confirmation of generalized tonic-clonic seizures, specimens from the right dentate gyrus were processed for light and electron microscopy. In PTZ-treated groups, the number of granule cells significantly decreased. Dark granule cells appeared in the deep layers of the granule cells in P10 and with the progress of age, they significantly increased in number and extended into the superficial layers of the granule cells. The dendritic spines diminished. Glial fibrillary acidic protein and caspase-3 expression increased. Ultrastructurally, granule cells showed irregular shaped nucleus, dilated rough endoplasmic reticulum (RER) cisternae, mitochondria with damaged cristae, large vacuoles, lysosomes, and lipofuscin granules. Dark granule cells characterized by electron-dense nucleus and cytoplasm containing disorganized Golgi bodies, swollen mitochondria with damaged cristae, numerous free ribosomes and few long strands of RER. Astrocytes had hypertrophied cell body. Acute treatment with PTZ-induced epileptic seizures caused toxic effect on the structure of rat dentate gyrus at different postnatal ages.

Anti-diabetic effect of moringa oleifera extract on parotid gland of albino rats

Aim: to investigate the antidiabetic effect of moringa oleifera on parotid gland.Materials and methods: 45 adult male albino rats weighing from 150-200 gm were used in this study. The rats were divided into three equal groups (15 rats each) as follow: Group I: The animals served as control group. Group II: The animals subjected to diabetic induction and did not receive any treatment. Group III: The animals subjected to diabetic induction, soon after blood analysis, animals of this group were given 200 mg/kg body wt. /day of moringa oleifera extract by gastric tube for 3 weeks. At the end of the moringa treatment, the rats were euthanized with over dose halothane and parotid glands were rapidly excised, then processed for: histological examination using heamatoxylin and eosin stain, transmission electron microscope and comet assay.Results: the examination with light microscope showed group I with normal architecture of the glandular tissue, the parotid gland sections showing densely packed acinar cells with large basally located nuclei while in group II parotid gland sections showed loss of acinar outlines with intracellular vacuolization and pyknotic nuclei. In-group III the acinar cells begin to regain their symmetrical shape and size. Ultrastructurely the serous cell of group I showed euchromatic nuclei, parallel cisternae rough endoplasmic reticulum, homogenous secretory granules and intact desmosomal attachments between cells. The serous cell of group II showing irregular nuclear membrane with predominant heterochromatin, dilated and irregular arrangements of rough endoplasmic reticulum and multiple vacuoles. In-group III the serous acini appeared with less number of vacuoles and numerous parallel cisternae of rough endoplasmic reticulum. The Comet assay results: In the control parotid glands, the majority of the cells appeared as homologous discs with a very low tail moment, very low percentage of tail length and tail DNA %. In group II tail formation was different from the normal gland cells in the number of tailed cells and the tail length. In group III the tail moment was found to be significantly decreased than that found in the group II.Conclusion: These results help to increase information about the usefulness of M. oleifera and its safety.

Histological and ultrastructural studies on the effect of amoxicillin on the liver of mice foetuses

Introduction: In spite of the beneficial role of the beta-lactam antibiotics in the treatment of many cases of urinary tract infections, acute otitis media, and pneumonia, yet some medical reports incriminating it in producing certain adverse consequences following its use. Antibiotics remain important in pregnancy and may be second to only iron and food supplement.Aim of Work: Hence, the present investigation was carried out to evaluate the effect of two doses of the beta-lactam antibiotic amoxicillin on the liver of maternally treated foetuses.Materials and Methods: The pregnant female mice were allocated into three groups. The pregnant mothers of the first group served as control group (injected intra peritoneally with the drug solvent) and those of the other two groups were injected intra peritoneally for 8 days from day 7 till day14 during gestation with the low dose (205 mg/ kg body weight) and high dose (820 mg/ kg body weight) of the beta-lactam antibiotics amoxicillin.Results: The histological examination of the foetal liver sections of amoxicillin-treated groups showed vacuolar and fatty degenerations in the cytoplasm of the hepatocytes, as well as inflammatory cell infiltration. At the ultrastructure level, the hepatocytes of maternally treated foetuses revealed conspicuous alternations, represented by devastations of mitochondria that displayed loss of their cristae and their internal matrices materials. Fragmentation of the cisternae of rough endoplasmic reticulum into smaller stacks was also observed.Conclusion: The use of such doses of the beta-lactam antibiotic amoxicillin induces morphological alterations in fotal liver of mice subjected to this antibiotic during the period of gestation

Changes in the Plantago lanceolata mature pollen ultrastructure and Pla l 1 allergen localisation after grain hydration

We have conducted the study of ultrastructural changes of wall and cytoplasm of Plantago lanceolata (English plantain) pollen grains during the first 10 min of hydration and activation processes, prior to germination, and localisation of Pla l 1, the major allergen of these pollen grains with immunocytochemical methods. The samples were fixed using conventional and freezing protocols for transmission electron microscopy. During the activation process, the intine is thickened in the apertural region and cytoplasm undergoes changes in the number of lipid bodies, amyloplasts, vacuoles and ribosomes. Also, we observed an association between lipid bodies, cisternae of rough endoplasmic reticulum, dictyosomes and vacuoles. An increase in the presence of allergenic particles (Pla l 1) in the exine, intine and the cytoplasm in activated pollen grains was detected, whereas this presence is not significant in mature pollen grains. The increase in the production and release of this allergen when pollen grains are activated suggest that Pla l 1 has an important role in pollen–stigma recognition and in the subsequent development of the pollen tube.

Ultrastructural study of uterine epithelium in the domestic cat during prenatal development

The study describes the sequence of ultrastructural changes of the endometrial lining epithelium, first in the primordial paramesonephric ducts, then in the differentiating uterine horns, and finally in the mature uterus. The research material comprised female fetuses of the domestic cat, aged 33–63 days post conceptionem (p.c.), and mature females. The ultrastructural observations of the developing epithelium were conducted using transmission electron microscopy (TEM) and light microscopy (LM). The results revealed two basic stages in the development of the uterine mucosal epithelium in the domestic cat: the development of the epithelium of the uterine segment of the paramesonephric ducts, lasting from day 33 to day 42 p.c., and the differentiation of this epithelium into the mucosal epithelium of the uterus, starting after day 42 p.c. and lasting until the end of the prenatal period. The epithelium of the uterine segments of the paramesonephric ducts is pseudostratified with a flat surface, all cells being characterized by the same distribution of desmosomes, ribosomes, rough endoplasmic reticulum (rER) cisternae, and mitochondria in the cytoplasm. The differentiating epithelium of the uterus after day 51 p.c. is pseudostratified with a varied height. In the epithelial cells there are increases of (i) the number and complexity of the junctional complexes, (ii) the number of invaginations of the lateral cell membranes, and (iii) the number of elongated mitochondria, and also there appear distended cisternae of the rER, lipid droplets and clusters of glycogen, which suggest increasing metabolism and secretory activity of the cells during the transformation of the epithelium.

The androgenic gland in male morphotypes of the Amazon River prawn Macrobrachium amazonicum (Heller, 1862)

Sexual differentiation and primary and secondary sexual characteristics in male crustaceans are modulated by hormones produced in the androgenic gland (AG). The AG is also responsible for the determination of morphotypes in caridean shrimps, such as Macrobrachium amazonicum that shows four morphotypes: translucent claw (TC), cinnamon claw (CC), green claw 1 (GC1) and green claw 2 (GC2). Here, we verified the anatomical, histological and ultrastructural characteristics of the AG in different morphotypes of this species with both amphidromous and hololimnetic life cycles. In submissive morphotypes (TC and CC), the AGs are reduced and concentrated in the terminal expansion of the distal portion of vasa deferentia (DVD), the ejaculatory ducts (ED). In dominant morphotypes (GC1 and GC2) these glands lie along the DVD and ED. Two morphological stages (I and II) were recorded for AG cells. In submissive morphotypes stage I cells predominated in the AGs, while in dominant morphotypes stage II cells were more common. AG cells in both stages were positive for proteins, confirming the protein nature of the secreted hormone. Stage I cells have abundant rough endoplasmic reticulum (RER) with numerous parallel cisternae, whereas in stage II cells, the cisternae of RER are highly dilated. Stage II cells do not produce secretory granules, but they undergo hypertrophy and the hormone release to hemolymph probably occurs by holocrine secretion. The AGs in TC, GC1 and GC2 morphotypes increase as the animals grow and are larger in GC1 males. On the other hand, AGs decrease in the CC morphotype as the animal grows. These differences are related to the type of reproductive strategy adopted by each morphotype. In M. amazonicum, the AGs show the same morphological, histochemical and ultrastructural patterns between the different life history populations.

The possible protective effect of Gardenia Jasminoides extracts on the dentate gyrus changes in an Alzheimer-induced model in adult male albino rats: Histological and Immunohistochemical study

Introduction: Alzheimer's disease (AD) is the most common diagnosed form of senile dementias, a neurodegenerative disease resulting in cognitive impairment in the elderly. Geniposide, extracted of Gardenia Jasminoides, is widely used herb for brain diseases and reduce amyloid plaques deposition which is an intricate process in AD.Aim of the work: demonstrate the histological changes in the dentate gyrus of hippocampus in an Alzheimer-induced model and the possible neuroprotective effect of Gardenia Jasminoides extract.Materials and methods: Thirty six adult male albino rats(4-6 months) , weighing180-200g divided into 3 groups. Group I the control group, group II given aluminum chloride dissolved in distilled water, (300mg/kg/day) orally for one month. Group (III) given Geniposide in distilled water,at a dose of (100mg/kg/day) orally concomitant with aluminum chloride at the same dose and period of the previous group. Cognitive functions were assessed by the passive avoidance test. Temporal lobes processed for H&E , congo red stains. Immunohistochemical study for detection of (GFAP) and (INOS). Tau protein can be phosphorylated by glycogen synthase Kinase-3β(GSK-3 β). Western blot assay to investigate the total protein expression glycogen synthase Kinase-3β(GSK-3 β) . Comet assay to detect DNA damage.Results: Alzheimer-induced model group showed significantly impaired cognitive performance which was improved after treatment with Geniposide extract. Changes in the dentate gyrus apparent increase in immature neurons, disturbed granular cell layer, distortion of pyramidal cells that appeared with pyknotic nuclei. Positive immunoreaction for GFAP in astrocytes were also observed. The ultra structural study exhibited neurons with apoptotic features, heterochromatic nuclei and their cytoplasm contained dilated cisternae of rough endoplasmic reticulum. Gardenia extracts ameliorated histological alterations.Conclusion: Gardenia Jasminoides extracts significantly ameliorated the neuro- degenerative alterations induced in the Alzheimer model. Daily supplements of Gardenia Jasminoides extracts might be of benefit for the elderly people at risk of developing AD.

Micromorphology and histochemistry of the secretory apparatus of Plumbago auriculata Lam.

This study interprets the structure and provides insights on the phyto-compounds of the leaves and calyces of Plumbago auriculata and evaluates its potential as a medicinal plant based on the presence of these compounds. Structure and possession of phyto-compounds were determined using light and electron microscopy and various histochemical tests. Glandular capitate and non-glandular uniserate trichomes were present on the surface of the calyx. Glandular trichomes bear a close resemblance to the digestive glands of the genus Drosera. Salt glands present on the leaf surface were abundant on the abaxial surface and revealed the presence of “transfer cells” reported for the first time in the genus. Abundant mitochondria, mini vacuoles, ribosomes, dictyosomes and rough endoplasmic reticulum cisternae were actively involved in the secretory process. Histochemical staining also revealed the presence of alkaloids and phenolic compounds that are of medicinal importance used to treat multiple ailments and also function as chemical deterrents in plants. Overall, this study contributes to the existing body of knowledge on the secretory structures of P. auriculata and provides new insights on the ultrastructural and histochemical aspects of the species.

From Photoinduced to Dark Cytotoxicity through an Octahedral Cluster Hydrolysis

Octahedral molybdenum and tungsten clusters have potential biological applications in photodynamic therapy and bioimaging. However, poor solubility and hydrolysis stability of these compounds hinder their application. The first water-soluble photoluminescent octahedral tungsten cluster [{W6 I8 }(DMSO)6 ](NO3 )4 was synthesised and demonstrated to be at least one order of magnitude more stable towards hydrolysis than its molybdenum analogue. Biological studies of the compound on larynx carcinoma cells suggest that it has a significant photoinduced toxicity, while the dark toxicity increases with the increase of the degree of hydrolysis. The increase of the dark toxicity is associated with the in situ generation of nanoparticles that clog up the cisternae of rough endoplasmic reticulum.

Periodontitis causes abnormalities in the liver of rats.

Periodontitis not only causes injury to the periodontium, but also damages other tissues such as: articulate, renal, cardiac, and hepatic. The objective of this study was to investigate periodontitis induced alterations in liver function and structure using an experimental model. Twenty female rats (Rattus norvegicus) were allocated into two groups: control and periodontitis. Gingival bleeding index and oxidative stress parameters and specific circulating biomarkers were measured. Immunohistochemistry was carried out using alkaline phosphatase (AlkP) staining of the liver. Hepatic tissues, cytokines, and lipid contents were measured. Histopathologic evaluation of the liver was carried out using light and electron microscopy. Liver histopathologic and immunohistochemistry assessment showed increase in steatosis score, and presence of binucleate hepatocytes and positive cells for AlkP in periodontitis versus control group. Ultrastructural evaluation showed significant increase in size and number of lipid droplets (LD), distance between the cisterns of rough endoplasmic reticulum (RER), mitochondria size, foamy cytoplasm, and glycogen accumulation in the liver of the periodontitis group compared with the control group. In addition, plasma levels of AlkP, high-density lipoprotein (HDL), triglycerides, and total cholesterol were also changed. Experimental periodontitis caused immunohistochemistry, histopathologic, ultrastructural, oxidative, and biochemical changes in the liver of rats.

Self-Assembled Rough Endoplasmic Reticulum-Like Proto-Organelles

SummaryNature has evolved elaborate, dynamic organelle morphologies for optimal organelle functions. Among them, cisternae stacks are the universal structure for most organelles. However, compared with the well-studied spherical cell/organelle membrane mimic, the fabrication of the ubiquitously present cisternal organelle-like membrane structures for organelle mimic remains a challenging task. Herein, rough endoplasmic reticulum (RER)-like helicoidal cisternae stacks were assembled to mimic the enzyme crowded environment in spatially confined RER cisternae. RER-like single helicoid, multiple helicoids, and secondary helix are all observed. Membrane electrostatics drives their formation and controls the percentages, which indicates the possible role of membrane electrostatics in RER shaping. The organelle-like cisternae stacks can reversibly expand and compress, which provides modulated crowded or de-crowded enzyme environment for biochemical reactions. This work provides advanced membrane models, and novel mechanisms for organelle shaping and helicoids formation, and holds great potential in biomimetics, cell biology, and advanced materials design.

Possible protective effect of curcumin on the thyroid gland changes induced by sodium fluoride in albino rats: light and electron microscopic study.

Thyroid gland regulates the body's metabolic rate and plays an exquisitely important role in the human health. Fluoride exposure can affect thyroid function. Curcumin is a potent antioxidant that works through several mechanisms. The aim of the present study was to demonstrate the hormonal, histological, and ultrastructural changes occurred in the thyroid gland induced by exposure to sodium fluoride (NaF) and study the possible protective effect of curcumin on the NaF-induced effects. Thirty male albino rats were randomly divided into 3 equal groups (10 rats each): the control group, NaF group, and NaF+Curcumin (NaF+Cur) group. Thyroid-stimulating hormone (TSH), triiodothyronine (T3) and thyroxine (T4) levels were assayed and thyroid tissues processed for light and transmission electron microscopic study. In NaF group, serum T3 and T4 levels were significantly decreased whereas TSH level was significantly increased compared to the control group. Thyroid tissues showed flattening of the epithelial lining with several follicular cell degenerations, hyperplasia, decreased colloid, disrupted basement membrane, cytoplasmic vacuolations, degenerated mitochondria, widening of rough endoplasmic reticulum cisternae, and vascular congestion compared to the control group. In the NaF+Cur group, serum TSH levels were significantly decreased in comparison with NaF group and no significant difference in comparison with the control group. Thyroid sections appeared apparently normal compared to the control group and NaF group. Sodium fluoride affected both the function and structure of the thyroid gland while curcumin was protective against these toxic effects.

Ultrastructure and function of the seminal vesicle of Bittacidae (Insecta: Mecoptera)

The fine structure of the seminal vesicle and reproductive accessory glands was investigated in Bittacidae of Mecoptera using light and transmission electron microscopy. The male reproductive system of Bittacidae mainly consists of a pair of testes, a pair of vasa deferentia, and an ejaculatory sac. The vas deferens is greatly expanded for its middle and medio-posterior parts to form a well-developed seminal vesicle. The seminal vesicle is composed of layers of developed muscles and a mono-layered epithelium surrounding the small central lumen. The epithelium is rich in rough endoplasmic reticulum and mitochondria, and secretes vesicles and granules into the central lumen by merocrine mechanisms. A pair of elongate mesodermal accessory glands opens into the lateral side of the seminal vesicles. The accessory glands are similar to the seminal vesicle in structure, also consisting of layers of muscle fibres and a mono-layered elongated epithelium, the cells of which contain numerous cisterns of rough endoplasmic reticulum and mitochondria, and a few Golgi complexes. The epithelial cells of accessory glands extrude secretions via apocrine and merocrine processes. The seminal vesicles mainly serve the function of secretion rather than temporarily storing spermatozoa. The sperm instead are temporarily stored in the epididymis, the greatly coiled distal portion of the vas deferens.

Ultrastructure of the larval Malpighian tubules in Terrobittacus implicatus (Mecoptera: Bittacidae).

The larvae of Bittacidae, a cosmopolitan family in Mecoptera, have an interesting habit of spraying the body surface with soil through the anus after hatching, and each molts. The fine structure of Malpighian tubules, however, remains largely unknown in the larvae of Bittacidae to date. Here, we studied the ultrastructure of the larval Malpighian tubules in the hangingfly Terrobittacus implicatus (Huang & Hua) using scanning and transmission electron microscopy. The larvae of T. implicatus have six elongate Malpighian tubules at the junction of the midgut and hindgut. The tubule comprises a basal lamina, a single-layered epithelium, and a central lumen. The basal plasma membranes of the epithelial cells are conspicuously infolded and generate a labyrinth. The epithelium consists of two types of cells: large principal cells and scattered stellate cells. Mitochondria and cisterns of rough endoplasmic reticulum are numerous in the principal cells but are sparsely distributed in the stellate cells, indicating that the principal cells are active in transport. On the other hand, spherites are only abundant in the principal cells and are likely associated with the soil-spraying habit of the larvae.

Ultrastructural Findings, at Micrometric and Nanometric Scales, in Rectal and Muscular Mucosa of Patients with HIV/AIDS and Anorectal Pathology

Objective: To determine the ultrastructural findings on Rectal Mucosa (RM) of patients with HIV/AIDS and anorectal pathologies (ARP), at micrometric and nanometric scales. Materials and methods: 5 patients were evaluated, 18 - 55 years old, with ARP (HIV co-infection with HPV, n = 4, and HIV-negative patient with HPV infection) (control n = 1), who were referred to the Coloproctology Unit of the HUC, and subjected to rectoscopy and biopsy. RM samples were identified, placed in a sterile plastic bottle with 1 mL of 2% glutaraldehyde and immediately transported for routine processing of fine cut (60 - 90 nm) to be evaluated via Transmission Electron Microscopy (TEM). They were fixed with Karnovsky solution with Millonig phosphate buffer (pH 7.4 and 320 mOsm) and post-fixed with OsO4 under the same conditions of pH and osmolarity. Results: Ultrastructural findings, at 10−6 scale: 1) Intestinal mucosa: vacuoles of mucus of different sizes that seem to be fused. 2) Smooth muscle cells: loss of definition of contractile myofilaments mass. 3) Unmyelinated axons and terminals of Schwann cells (SC): Edema and loss of their plasma membranes in some areas of association with axon terminals as well as abundant collagen fibers associated with SC. Ultrastructural findings, at 10−9 scale: 1) Smooth muscle cells: folded wrapper cores and edema of mitochondria and rough endoplasmic reticulum cisterns (RER). 2) Myelinated axon terminals: Loss of synaptic vesicles. 3) Fibroblasts: One observes mitochondria and cisterns of RER with alterations. All these alterations can generate intestinal and anorectal dysfunction in these patients. Conclusions: The HIV causes changes in rectal and muscular mucosa despite HAART treatment with undetectable viral load.

The effect of diabetes mellitus on the rat ventral prostate and the possible protective role of Ginkgo biloba extracts

Context Diabetes mellitus (DM) is a worldwide common disease that causes many complications in the male genital system including the prostate gland. Many studies have shown that extracts of Ginkgo biloba have antioxidant and free radical eliminating effects. Aim The present study aims to explore the histological effects of DM on the ventral prostate gland in rats and the possible protective role of Ginkgo extracts. Materials and methods Forty-five adult albino male rats were chosen for this study and they were classified into three equal groups. The control group was divided into two subgroups: the subgroup 1 rats received distilled water for 6 weeks; the subgroup 2 rats were injected intraperitoneally by a single dose of 0.15 ml 0.1 mol/l citrate buffer. To induce diabetes rats in the diabetic and protective groups were administered 60 mg/kg streptozotocin intraperitoneally, a week later rats in the protective group received Ginkgo extract orally in a dose of 100 mg/kg/day for 6 weeks. Six weeks after diabetes induction, samples from the ventral prostate from all groups were obtained for histological examination. Results No structural differences between the two control subgroups were observed. The diabetic group showed focal epithelial stratification with pyknotic nuclei resting on the disrupted basement membrane. By electron microscope (EM) the cells had irregular nuclei, few mitochondria, many cytoplasmic vacuoles, dilated rough endoplasmic reticulum (rER) cisternae, and few apical microvilli. In other areas, the cells were destructed with dissolved cytoplasm; many fragmented rounded bodies were observed in the lumen. The Ginkgo was found to improve most of the prostatic changes associated with DM. Conclusion Ginkgo extracts improve the prostatic changes produced by DM.

Ultrastructural Alterations of Liver Tissue Cells in Methotrexate-Treated Balb/c Mice.

Aim:The current study investigated the efficacy of methotrexate (MTX) on liver tissue cells of Balb/c mice at the ultrastructural level using transmission electron microscopy.Background:This agent is well known and used as a chemotherapeutic agent for a long time and not selective for cancer cells so, healthy cells beside cancer cells are also affected by MTX.Materials and Methods:Experimental animals were divided into two groups; the first group was kept without treatment and served as the control, the second group was treated with 115 mg/kg MTX i.p. once weekly for 4 weeks and sacrificed under anesthesia after the 4th week. The liver tissues were osmium fixed and embedded in araldite, sectioned and observed under transmission electron microscope.Results:Normal cell ultrastructure was determined in the control group whereas the liver cells of the MTX-treated group revealed ultrastructural alterations, such as the increase in lipid droplets, discontinuity of rough endoplasmic reticulum cisternae and vacuole formation. In addition, the loss of cytoplasmic material in hepatocytes was also evident. Condensation of nuclear chromatin and fusion of nucleic membranes were observed in the liver cells of the treated group.Conclusions:Results of the study indicated that MTX, used for different types of medical treatment, disturbed liver cell ultrastructure.

Bacteria arise at the border of mycoplasma-infected HeLa cells, containing cytoplasm with either malformed cytosol, mitochondria and endoplasmic reticulum or tightly adjoined smooth vacuoles.

ABSTRACTA study with transmission electron microscopy of mycoplasma-contaminated HeLa cells using five cell donors referred to as donors A, B, C, D and E, observations are herein presented. Experiments performed with cells from donors B, C and D, revealed the presence of Mycoplasma hyorhinis after PCR and sequencing experiments. Bacteria probably originated from a cytoplasm with compacted tiny granular particles replacing the normal cytosol territories, or from the contact with the cytoplasm through a clear semi-solid material. The compact granularity (CG) of the cytoplasm was crossed by stripes of smooth and rough endoplasmic reticulum cisternae. Among apparently normal mitochondria, it was noted, in variable proportions, mitochondria with crista-delimited lucent central regions that expand to and occupied the interior of a crista-less organelle, which can undergo fission. Other components of the scenarios of mycoplasma-induced cell demolition are villus-like structures with associated 80-200 nm vesicles and a clear, flexible semi-solid, process-sensitive substance that we named jam-like material. This material coated the cytoplasmic surface, its recesses, irregular protrusions and detached cytoplasmic fragments. It also cushioned forming bacteria. Cyst-like structures were often present in the cytoplasm. Cells, mainly apoptotic, exhibiting ample cytoplasmic sectors with characteristic net-like profile due to adjoined vacuoles, as well as ovoid or elongated profiles, consistently appeared in all cells from the last four cell donors. These cells were named “modified host cells” because bacteria arose in the vacuoles. The possibility that, in some samples, there was infection and/or coinfection of the host cell by another organism(s) cannot be ruled out.

Ultrastructure of plasma cells in harderian gland of laying hens.

Ultrastructure of plasma cells in Harderian gland was investigated using the transmission electron microscopy. For this research, we examined the glands of 32 laying hens collected at 1, 7, 20 and 40days and 4, 6, 8 and 12months of the birds' ages. The research showed that the stroma of the gland contains a large number of lymphocytes and plasma cells. Most of the plasma cells are mature, but morphologically do not show productive activity. Only some individual plasma cells, situated under the secretory epithelium of primary and secondary ducts, have extremely dilated cisternae of rough endoplasmic reticulum which contain moderately dense, granular material. The morphology of these cells indicates that they are in active stage of immunoglobulin production. Also, we identified plasma cells with two types of Russell bodies. One type of these bodies was small, round or oval, while the other had irregular, angular shape. It was noted that one plasma cell never contains both type of Russell bodies at the same time. These cells were often affected by apoptosis. Among them, in deeper part of the stroma, were situated the small plasmablast cells.

Changes in Pinealocytes type I and II of Adult Albino Rat Exposed to Different Wavelengths of Light or Confined to Constant Darkness: A Morphological and Electron Microscopic Study

Introduction: the pineal gland is a neuro-endocrine gland that secretes melatonin hormone whichregulates the circadian rhythm, psychiatric disorder and age changes resulting from exposure to differentlight wavelengths or darkness. Intensity, duration and wavelength of light control the activity of pinealgland.Aim of work: the purpose of this study was to monitor the morphological and electron microscopicchanges in the pinealocytes type I and II of albino rats exposed to either constant (24hrs/day) red light(long wavelength) or blue light (short wavelength) as well as confined to constant darkness as comparedto control group subjected to normal diurnal conditions.Material and methods: forty adult male albino rats were divided into four subgroups. Group I (GI):the rats were kept under normal diurnal conditions, group II (GII): the rats were confined to constantdarkness, group III (GIII): the rats were exposed to constant red light (long wavelength; 670nm) andgroup IV (GIV): the rats were subjected to constant blue light (short wavelength, 450nm); for four weekscontinuously.Results: morphological findings of pinealocytes type I (PI) were analyzed statistically and revealed anincrease in the nuclear number of PI in GII, decrease in the nuclear number of PI in GIV and nonsignificantdifference in nuclear number of PI in GIII as compared to the control group. In addition,rats of GIV reported a statistically significant increase in the amount of collagen fibers between looselypacked parenchymal cells. Electron microscopic results of the cytoplasm of PI in GII showed abundantcell organelles such as mitochondria, numerous ribosomes and multiple lipid droplets together withwell-developed Golgi bodies, scarce dense core vesicles (DCV), few cisternae of smooth endoplasmicreticulum (SER) and rough endoplasmic reticulum (RER). GIII demonstrated similar results to that ofGI. On the other hand, GIV showed scarce cytoplasmic organelles such as few mitochondria; mostlydistended with disturbed cristae, scattered lipid droplets with abundant DVC and numerous cisternaeof SER. Ultrastructurally, PI nuclei of GII exhibited infolded nuclear envelope with heterochromatickaryoplasm and prominent nucleoli while GIV revealed reduction of the nuclear chromatin with ruptureof nuclear envelope at certain sites. However, GIII nuclei demonstrated results similar to that of GI. Noobservable changes were detected by light and electron microscopy of PII in the different experimentalgroups apart from the presence of statistically significant increase in the nuclear number of PII in GII.Moreover, the PII cytoplasm showed scarce mitochondria in GI, II and RER in GIV. The glial cellsdemonstrated statistically significant increase in GIV but non-significant differences were noticed in theother groups as compared to GI.Conclusion: it could be concluded that the morphological and electron microscopic changes ofpinealocyte type I indicate decrease in the activity of pinealocytes type I on exposure to constant shortwavelength blue light and increase in the activity of PI confined to constant darkness. While the exposureto constant long wavelength red light demonstrates results similar to the control group. There were nochanges in the structure of pinealocytes type II in the different experimental groups, exposed to differentlight wavelengths or confined to darkness.