Botucatu - CME - Centro de Microscopia Eletrônica

URI Permanente para esta coleçãohttps://hdl.handle.net/11449/253749

Navegar

Agora exibindo 1 - 20 de 134

Neonatal exposure to aluminum chloride predisposes adult and senile gerbils to the prostatic hyperplasia
(2023-05-01) Gomes, Liana Silva ; da Silva Lima, Danilo ; Costa, Janaína Ribeiro ; Naves, Jane Sousa ; Marques, Mara Rúbia ; Taboga, Sebastião Roberto ; Ghedini, Paulo César ; Biancardi, Manoel Francisco ; Alcantara dos Santos, Fernanda Cristina ; Universidade Federal de Goiás (UFG) ; Universidade Estadual Paulista (UNESP)
Several pollutants can alter neonatal prostatic development predisposing this gland to diseases. The toxicity and endocrine disrupting potential of aluminum has been reported in many organs, but little is known about its effects on the prostate. This study aimed to evaluate the effects that aluminum neonatal exposure can cause in the male ventral prostate and in the female prostate of adult and senile gerbils. Male and female pups were treated orally with aluminum chloride (10 mg/kg) from the 1st to the 14th day life. After treatment, the animals were aged until they reached 90 days or 1 year of life. The prostate glands were dissected out and submitted to morphological, immunohistochemical and ultrastructural analyses. Ventral prostates of adult males showed moderate hyperplasia and increased epithelial proliferation not associated with androgen receptor (AR) deregulation. On the other hand, senile males showed intense prostatic hyperplasia, and increased cell proliferation and epithelial AR regulation. Additionally, at both ages, there was a reduction in the prostate secretory function. The morphological changes observed in the female prostate were like those found in males. However, in adult females, prostatic hyperplasia was accompanied by a lower regulation of AR and estrogen receptor alpha, while in senile females, intense hyperplastic growth was associated with an increase in estrogen receptor alpha and a reduction in stromal AR. These results demonstrate that aluminum chloride neonatal exposure alters the hormonal regulation of the male and female prostate, inducing tissue damage that occurs in adulthood and intensifies during aging.
Azadirachtin-based insecticide impairs testis morphology and spermatogenesis of the southern armyworm Spodoptera eridania (Lepidoptera: Noctuidae)
(2023-05-01) Scudeler, Elton Luiz ; Daquila, Bruno Vinicius ; de Carvalho, Shelly Favorito ; Conte, Helio ; Padovani, Carlos Roberto ; dos Santos, Daniela Carvalho ; Universidade Estadual Paulista (UNESP) ; State University of Maringá
Background: In the search for alternative tools for integrated pest management, azadirachtin, a botanical insecticide, has been used with the most promising activity against Spodoptera spp., but the mechanism of cytotoxicity on reproductive organs remains unclear. Spodoptera eridania (Stoll, 1782) is a polyphagous pest with great economic importance that has become an important target to elucidate the action of azadirachtin on the reproductive organs of insect pests, helping to understand the deleterious effects caused by its exposure. This study evaluated the effects of chronic exposure to azadirachtin on the morphology and ultrastructure of S. eridania larval testes as well as larval development. Results: Azadirachtin exposure (6 or 18 mg a.i. L−1) caused a progressive increase in cumulative mortality and reduced gain in body mass after 5 days. Testicular structure indicated a reduction in their size with internal morphological changes such as spermatogonia, spermatogonial, spermatocytes and spermatid cysts in degeneration. The occurrence of cell death in germ and somatic cells was evidenced by the TUNEL technique. Electron microscopy revealed changes in cystic cells, such as cytoplasmic membrane rupture and cytoplasmic vacuolization. Chromatin compaction, changes in the rough endoplasmic reticulum and Golgi complex cisternae were observed in germ cells. Apoptotic bodies occurred between germ cell cysts. Conclusion: Azadirachtin damaged the testes of S. eridania larvae, and these changes compromised spermatogenesis and consequently the development of the reproductive potential of this specimen, making azadirachtin a promising botanical insecticide for application in integrated pest management programs. © 2022 Society of Chemical Industry.
Acute and chronic effects of the organophosphate malathion on the pancreatic α and β cell viability, cell structure, and voltage-gated K+ currents.
(2023-03-01) Martins, J.R.N ; Lopes, S. ; Hurtado, H. N. ; da Silva, F. N. ; Villard, D. R. ; Taboga, S. R. ; Souza, K.L.A ; Quesada, I. ; Soriano, S. ; Rafacho, A. ; Universidade Federal de Santa Catarina (UFSC) ; University of Alicante ; Universidade Federal do Rio de Janeiro (UFRJ) ; Universidade Estadual Paulista (UNESP) ; Universidad Miguel Hernández ; Biomedical Research Center in Diabetes and Associated Metabolic Disorders (CIBERDEM)
Studies indicate that the pesticide malathion may have a role in diabetes. Herein, we determined the effects of different concentrations of malathion on survival, ultrastructure, and electrophysiologic islet cell parameters. Acutely, high concentrations of malathion (0.5 or 1 mM) increased cell death in rat islet cells, while low concentrations (0.1 mM) caused signs of cell damage in pancreatic α and β cells. Exposure of RINm5F cells to malathion for 24 or 48 h confirmed the reduction in β-cell viability at lower concentrations (0.001–100 µM). Chronic exposure of mouse pancreatic α and β cells to 3 nM of malathion led to increased voltage-gated K+ (Kv) currents in α-cells. Our findings show a time and concentration dependency for the malathion effect on the reduction of islet cell viability and indicate that pancreatic α cells are more sensitive to malathion effects on Kv currents and cell death.
Intraspecific variation in ultrastructure and secretion of the resin canals in Anacardium humile (Anacardiaceae)
(2023-05-01) de Carvalho, Shelly Favorito ; Scudeler, Elton Luiz ; dos Santos, Daniela Carvalho ; Machado, Silvia Rodrigues ; Universidade Estadual Paulista (UNESP)
The study combines a range of light and electron microscopy methods to access variation in secretion and ultrastructure in the secretory canals in the above- and belowground stems of Anacardium humile, which here serves as a model system. The aboveground stem canals show epithelial cells with ultrastructural characteristics typical of cells active in secretion, while in the belowground stems, the subcellular characteristics are typical of cells with low rates of metabolism. The secretory canals of the belowground stems show uniformity in size and shape, a large central vacuole, a cytoplasm reduced to a thin layer at the cell periphery, and a reduced population of organelles. The aboveground stem canals had voluminous nuclei with evident nucleoli, a very dense cytoplasm with free ribosomes, polyribosomes, mitochondria with developed cristae, and ellipsoid plastids with electron-opaque droplets surrounded by a periplastid reticulum. The vacuoles were of different sizes and often had membranous contents and the dictyosomes were very developed with dilated ends to the cisternae, rough endoplasmic reticulum, and numerous vesicles. The results show that particularities in above- and belowground environment have significant implications for ultrastructural morphology and functioning of secretory canals in the stems of A. humile.
Peltate trichomes in the dormant shoot apex of Metrodorea nigra, a Rutaceae species with rhythmic growth
(2023-01-01) Machado, S. R. ; de Deus Bento, K. B. ; Canaveze, Y. ; Rodrigues, T. M. ; Universidade Estadual Paulista (UNESP) ; Federal University of Rio de Janeiro
In Metrodorea nigra, a Rutaceae species with rhythmic growth, the shoot apex in the dormant stage is enclosed by modified stipules. The young organs are fully covered with peltate secretory trichomes, and these structures remain immersed in a hyaline exudate within a hood-shaped structure. Our study focused on the morpho-functional characterization of the peltate trichomes and cytological events associated with secretion. Shoot apices were collected during both dormant and active stages and processed for anatomical, cytochemical and ultrastructural studies. Trichomes initiate secretion early on, remain active throughout leaf development, but collapse as the leaves expand; at which time secretory cavities start differentiation in the mesophyll and secretion increases as the leaf reaches full expansion. The subcellular apparatus of the trichome head cells is consistent with hydrophilic and lipophilic secretion. Secretion involves two vesicle types: the smaller vesicles are PATAg-positive (periodic acid/thiocarbohydrazide/silver proteinate) for carbohydrates and the larger ones are PATAg-negative. In the first phase of secretory activity, the vesicles containing polysaccharides discharge their contents through exocytosis with the secretion accumulating beneath the cuticle, which detaches from the cell wall. Later, a massive discharge of lipophilic substances (lipids and terpenes/phenols) results in their accumulation between the wall and cuticle. Release of the secretions occurs throughout the cuticular microchannels. Continued protection of the leaves throughout shoot development is ensured by replacement of the collapsed secretory trichomes by oil-secreting cavities. Our findings provide new perspectives for understanding secretion regulation in shoot apices of woody species with rhythmic growth.
The complex role of telocytes in female prostate tumorigenesis in a rodent model
(2022-09-01) Maldarine, Juliana S. ; Sanches, Bruno D. A. ; Santos, Vitória A. ; Góes, Rejane M. ; Vilamaior, Patricia S. L. ; Carvalho, Hernandes F. ; Taboga, Sebastião R. ; Universidade Estadual de Campinas (UNICAMP) ; Universidade Estadual Paulista (UNESP)
The prostate is not an organ exclusive to the male. It is also found in females of several species, including humans, in which part of the Skene gland is homologous to the male prostate. Evidence is accumulating that changes in the stroma are central to tumorigenesis. Equally, telocytes, a recently discovered type of interstitial cell, are essential for the maintenance of stromal organization. However, it is still uncertain whether there are telocytes in the female prostate and if they play a role in tumorigenesis. The present study used ultrastructural and immunofluorescence techniques to investigate the presence of telocytes in the prostate of Mongolian gerbil females, a rodent model that often has a functional prostate in females, as well as to assess the impact of a combination of N-ethyl-N-nitrosourea, testosterone, and estradiol on telocytes. The results point to the presence of telocytes in the female prostate in the perialveolar and interalveolar regions, and reveal that these cells are absent in regions of benign and premalignant lesions in the gland, in which the perialveolar smooth muscle is altered. Additionally, telocytes are also closely associated with infiltrated immune cells in the stroma. Our data suggest that telocytes are important for both the maintenance of smooth muscle and prostatic epithelium integrity, which indicates a protective role against the advancement of tumorigenesis. But telocytes are also associated with immune cells and a proinflammatory/proangiogenic role for these cells cannot be ruled out, implying that telocytes have a complex role in prostatic tumorigenesis in females.
Adhesive secretion in Schizolobium parahyba (Vell.) Blake (Leguminosae: Caesalpinioideae): histochemical and morpho-functional characterization of this unusual feature in woody plants
(2022-01-01) Paiva, Elder Antônio Sousa ; Oliveira, Denise Maria Trombert ; Canaveze, Yve ; Machado, Silvia Rodrigues ; Universidade Federal de Minas Gerais (UFMG) ; Universidade Federal do Rio de Janeiro (UFRJ) ; Universidade Estadual Paulista (UNESP)
The legume tree Schizolobium parahyba from the Brazilian Atlantic Forest shows young aerial organs covered with a sticky exudate. Aiming to clarify the functional aspects of the sticky secretions, we performed analyses on the dynamics of secretion through the plant development and characterized the chemical nature of the exudates by histochemical tests. We also studied the secretory tissue using light and electron microscopy. The production of the exudates starts soon after seed germination, being evident in the epicotyl but not in the hypocotyl and cotyledons. The secretory activity extends throughout the juvenile and pre-reproductive phase, in primary stems and leaf portions. After the first flowering, secretion was no longer observed. The lipid exudates are secreted by the epidermis and are composed of mixtures of essential oils and oleoresins. Modified plastids, extensive rough endoplasmic reticulum, proliferated smooth endoplasmic reticulum, enlarged vacuoles containing flocculant materials, membrane debris, and convoluted tubules/lamellae membranes covered with osmiophilic deposits are the main features of the secretory epidermal cells. Secretion exits the protoplast by exocytosis and accumulates in the cuticle, resulting in a sheath of concentric bands of electron-dense deposits, and is released by cuticle peeling. The hydrophobic nature of the secretion, which forms an impermeable layer on the epidermis of young organs, is a relevant attribute of the aerial organs of S. parahyba. In addition to protecting against desiccation, this exudate effectively captures particles and immobilizes insects and other arthropods.
Midgut and fat body: Multisystemic action of pyriproxyfen on non-target organism Ceraeochrysa claveri (Neuroptera: Chrysopidae)
(2022-01-15) Scudeler, Elton Luiz ; Carvalho, Shelly Favorito de ; Garcia, Ana Silvia Gimenes ; Santorum, Marilucia ; Padovani, Carlos Roberto ; Santos, Daniela Carvalho dos ; Universidade Estadual Paulista (UNESP)
Morphological tools can assist in the evaluation of effects of insecticides on non-target insects. Pyriproxyfen, a juvenile hormone analog, is known to interfere with growth and metamorphosis of insects. However, there are studies showing indirect effects on natural enemies, including green lacewings. Few prior studies describe morphological effects of pyriproxyfen on target insect organs, especially on natural enemies. Through morphological tools, this study aimed to characterize the midgut and fat body, both important organs of digestion and great metabolic activity respectively, of the predator Ceraeochrysa claveri after chronic exposure to pyriproxyfen. Larvae of C. claveri were fed Diatraea saccharalis egg clusters treated with pyriproxyfen in solution of 50 or 100 mg a.i. L−1 throughout the larval stage. The biological data revealed significant increases in development time, especially in the third instar, and in cumulative mortality from the prepupal into the pupal stage. Morphological analysis of adult midgut (≤24 h old) showed damage including formation of epithelial folds, intercellular spaces, emission of cytoplasmic protrusions. Both fat body regions presented decrease of lipid droplets, vacuolization of trophocytes and mitochondrial injury featuring a multisystemic action. In both organs, pyriproxyfen exposure induced significant oxidative stress by mitochondrial superoxide production. Cytoprotective responses were induced in midgut and fat body cells by augmenting the number of cytoplasmic granules containing calcium and expression of HSP 90. Both organs proved to be efficient in presenting histopathological alterations, showing the sensitivity and applicability of this morphological tool for evaluating other insecticides in non-target organisms.
Subacute exposure to aluminum chloride causes prolonged morphological insults in the ventral male prostate and in the female prostate of adult gerbils
(2022-02-01) da Silva Lima, Danilo ; da Silva Gomes, Liana ; de Sousa Figueredo, Esther ; e Silva, Yasmin Inocêncio Fernandes ; Silva, Edvaldo Mendes ; de Souza Bovi, Thais ; Taboga, Sebastião Roberto ; Marques, Mara Rúbia ; Biancardi, Manoel Francisco ; dos Santos, Fernanda Cristina Alcantara ; Universidade Federal de Goiás (UFG) ; Universidade Estadual Paulista (UNESP)
Aluminum (Al) is a widespread metal in the environment, and is found in fresh or processed foods, household utensils, packaging, and medicines. In addition to its high toxicity, Al can also have estrogenic agonistic effects on target organs. Considering that the Al effects on the prostate are little known, the aim of this study was to evaluate the impact of aluminum chloride (AlCl3) subacute exposure on the morphophysiology of the male ventral prostate and the female prostate of adult gerbils. Furthermore, the glandular restoration capacity in face of the Al insults was evaluated in gerbils that were submitted to 30 days of recovery. Male and female gerbils were orally exposed to AlCl3 (10 mg/kg) for 30 consecutive days. The animals were euthanized 1 day (Al1D) or 30 days (Al30D) after the end of treatment. Prostates were dissected out and processed for structural, ultrastructural and immunohistochemical analyses. Male ventral prostates and female prostates of the Al1D group showed increased cell proliferation, glandular hyperplasia, increased secretory activity and greater androgen receptor immunoreactivity. In males, Al withdrawal (Al30D) allowed a partial recovery of the prostate, as the glandular secretory activity, and frequency of androgen receptor positive cells were similar to the control group. In females, the recuperation interval (Al30D) was not enough to restore the prostatic morphology, since the gland remained hyperplastic, proliferative, and with greater androgen and estrogen receptor immunoreactivity. These data alert to the importance of avoiding Al exposure, since this metal can have a harmful and prolonged action on the prostate.
TEMPO-oxidized cellulose poly-ionic drawn fiber, a cell support system proof of concept
(2021-10-01) Rios, Mariana Alves ; Barbugli, Paula Aboud ; Iemma, Mônica Rosas Costa ; Grande, Rafael ; Carvalho, Antônio José Felix ; Trovatti, Eliane ; University of Araraquara ; Universidade Estadual Paulista (UNESP) ; Aalto Universitty ; Universidade de São Paulo (USP)
The development of new cell carrier systems is crucial for application in regenerative medicine, once they deliver the cells to the injured tissue to trigger the repair and stimulate the regeneration. Here we report the preparation of a cell carrier system in fiber shape, in which the cells osteo-1 are incorporated. For the fiber formation, the oxidized cellulose nanofibers suspension loaded with cells is complexed with calcium ions in a pulling process giving rise to the fiber loaded with cells, with dimensions which allow it to handle. The microscopic images showed the success of the proposed method to incorporate the cells into the fibers. The results of the in vitro viability tests indicated the capability of the fibers to keep the cells alive and to mineralize them, indicating that their osteogenic capability was not affected. In addition, the fiber disintegration studies showed the system is capable of releasing the cells, suggesting the potential of the fibers as a new assembled hydrogel carrier cell therapy.
Prenatal and pubertal exposure to 17α-ethinylestradiol cause morphological changes in the prostate of old gerbils
(2021-10-01) Fleury, Fernanda G. ; Guimarães, Luísa R. F. ; Rezende, Elisa B. ; Martins, Tracy M. M. ; Caires, Cássia R. S. ; dos Santos, Fernanda C. A. ; Taboga, Sebastião R. ; Perez, Ana P. da S. ; UFJ ; Faculty of Medicine of São José do Rio Preto-FAMERP ; Universidade Federal de Goiás (UFG) ; Universidade Estadual Paulista (UNESP) ; Universidade Estadual de Campinas (UNICAMP)
This study evaluated such as exposure to ethinylestradiol during the prenatal (18th–22nd day) and pubertal (42nd–49th day) periods acts on the male ventral prostate and female prostate of 12-month old gerbils. We performed the analysis to serum hormone levels for estradiol and testosterone. The prostates were submitted to morphometric and immunohistochemical analyses. Exposure to ethinylestradiol during these developmental periods decreased the testosterone serum levels in males and increased the estradiol serum levels in females. Morphologically, prostate intraepithelial neoplasia and disorders in the arrangement of the fibrous components were observed in the prostate glands of both sexes of gerbil exposed to ethinylestradiol during development periods. In the male prostate, the ethinylestradiol promoted decreased in the frequency of positive epithelial cell for androgen receptor (AR) and increased the frequency of positive stromal cell for estrogen receptor α. However, in the female prostate, this synthetic estrogen caused AR upregulation and increased cell proliferation. This study shows that the exposure to ethinylestradiol during development phases alters the morphology and the hormonal signaling in the male and female prostates of old gerbils, confirming the action of ethinylestradiol as endocrine disruptor.
Stromal cell interplay in prostate development, physiology, and pathological conditions
(2021-09-01) Sanches, Bruno D. A. ; Maldarine, Juliana S. ; Vilamaior, Patricia S. L. ; Felisbino, Sergio L. ; Carvalho, Hernandes F. ; Taboga, Sebastião R. ; Universidade Estadual de Campinas (UNICAMP) ; Universidade Estadual Paulista (UNESP)
Advances in prostatic stroma studies over the past few decades have demonstrated that the stroma not only supports and nourishes the gland's secretory epithelium but also participates in key aspects of morphogenesis, in the prostate's hormonal metabolism, and in the functionality of the secretory epithelium. Furthermore, the stroma is implicated in the onset and progression of prostate cancer through the formation of the so-called reactive stroma, which corresponds to a tumorigenesis-permissive microenvironment. Prostatic stromal cells are interconnected and exchange paracrine signals among themselves in a gland that is highly sensitive to endocrine hormones. There is a growing body of evidence that telocytes, recently detected interstitial cells that are also present in the prostate, are involved in stromal organization, so that their processes form a network of interconnections with both the epithelium and the other stromal cells. The present review provides an update on the different types of prostate stromal cells, their interrelationships and implications for prostate development, physiology and pathological conditions.
Prolactin promotes a partial recovery from the atrophy of both male and female gerbil prostates caused by castration
(2021-12-01) Zanatelli, Marianna ; Colleta, Simone Jacovaci ; Guerra, Luiz Henrique Alves ; Santos, Fernanda Cristina Alcântara ; Góes, Rejane Maira ; Vilamaior, Patricia Simone Leite ; Taboga, Sebastião Roberto ; Universidade Estadual de Campinas (UNICAMP) ; Universidade Estadual Paulista (UNESP) ; Universidade Federal de Goiás (UFG)
Background: The male and female prostates are controlled by steroid hormones, suffering important morphological and physiological changes after castration. Prolactin is involved in the regulation of the male prostate, having already been identified in the tissue, acting through its receptor PRLR. In the Mongolian gerbil, in addition to the male prostate, the female prostate is also well developed and active in its secretion processes. The aim of the present study was to evaluate the effects of exposure to exogenous prolactin in the prostate of both intact and castrated male and female gerbils in order to establish if prolactin administration can sustain prostate cell activity in conditions of sexual hormone deprivation. Methods: The morphological analyses were performed by biometric analysis, lesion histological analysis and morphometric-stereological aspects. In addition, immune-cytochemical tests were performed for prolactin and its receptor, as well as for the receptors of androgen and oestrogen and serum prolactin dosage. All data were submitted to ANOVA or Kruskal-Wallis tests for comparison between groups. P < 0.05 was considered to be statistically significant. Results: The results showed a strong influence of prolactin on the morphology of the prostate, with the development of important epithelial alterations, after only 3 days of administration, and an expressive epithelial cell discard process after 30 days of administration. Prolactin acts in synergy with testosterone in males and mainly with oestrogens in females, establishing different steroid hormonal receptor immunoreactivity according to sex. It was also demonstrated that prolactin can assist in the recovery from some atrophic effects caused in the gland after castration, without causing additional tissue damage. Conclusions: The prolactin and its receptor are involved in the maintenance of the homeostasis of male and female gerbils, and also cause distinct histological alterations after exogenous exposure for 3 and 30 days. The effects of prolactin are related to its joint action on androgens and oestrogens and it can also assist in the recovery from the atrophic effects of castration.
Apoplasmic barrier in the extrafloral nectary of Citharexylum myrianthum (Verbenaceae)
(2021-08-01) Machado, Silvia Rodrigues ; Rodrigues, Tatiane Maria ; Universidade Estadual Paulista (UNESP)
Main conclusion: The cytological changes underlying the formation of an apoplasmic barrier in the multi-layered extrafloral nectaries of Citharexylum myrianthum are compatible with the synthesis, transport and deposition of suberin. In terms of ontogenesis and function, the intermediate layers of these nectaries are homologous with the stalks of nectar-secreting trichomes. Abstract: Anticlinal cell wall impregnations are common in trichomatic nectaries and their functions as endodermis-like barriers have been discussed because of possible direct effects on the nectary physiology, mainly in the nectar secretion and resorption. However, the cytological events linked to nectary wall impregnations remain little explored. This study documents the ontogenesis and the fine structure of the EFN cells, and cytological events linked to the wall impregnations of multi-layered extrafloral nectaries (EFNs) in Citharexylum myrianthum Cham. (Verbenaceae). EFNs are patelliform, and differentiated into (a) a multicellular foot, which is compound in structure and vascularised with phloem strands, (b) a bi-layered intermediate region with thickened cell walls and (c) a single-layered secretory region with palisade-like cells. EFNs are protodermal in origin, starting with a single protodermal cell and ending with the complex, multi-layered structure. The cell wall impregnations first appear in the very young EFN and increase towards maturity. Lipid patches (assumed to be suberin) are deposited on the inner faces of the primary walls, first along the anticlinal walls and then extend to the periclinal walls. On both walls, plasmodesmata remain apparently intact during the maturation of the EFNs. In the peripheral cytoplasm there are abundant polymorphic plastids, well-developed Golgi bodies often close to rough endoplasmic reticulum profiles, mitochondria and polyribosomes. Cytological events linked to the wall impregnations are consistent with suberin synthesis, transport and deposition. Our findings offer new insights into the structure-properties of specialised nectary cell walls and so should contribute to our knowledge of the physiological and protective roles of this structure in nectar glands.
Effects of exercise on neuromuscular junction components across age: Systematic review of animal experimental studies Neuroscience
(2015-11-24) Krause Neto, Walter ; Ciena, Adriano Polican ; Anaruma, Carlos Alberto ; De Souza, Romeu Rodrigues ; Gama, Eliane Florencio ; São Judas Tadeu University ; Universidade Estadual Paulista (UNESP)
Background: During almost one-third of our life, maturation of the nervous system promotes strength and muscle mass increase. However, as age advances, the nervous system begins to suffer a slow and continue reduction of its functions. Neuromuscular junction (NMJ) is one of the structures of which change due to aging process. Physical training leads to significant adjustments in NMJs of young and aged animals. Nevertheless, studies that aimed to investigate this effect have, in many cases, methodological variables that may have some influence on the result. Thus, this study aimed to carry out a systematic review about the effects of exercise training on the NMJ compartments of young, adult and aged animals. Results: We searched PubMed, Google Scholar, Science Direct, Scielo and Lilacs databases for animal experimental studies that studied exercise effects on the NMJs components across age. After inclusion and exclusion criteria, we included nine articles in systematic review and two for meta-analysis (young/adult NMJ). Conclusions: We identified that exercise training cause NMJ hypertrophy on young animals and NMJ compression on aged ones. However, many methodological issues such as age, skeletal muscle and fibers type, and type of exercise and training protocol might influence the results.
Ultrastructure of the Lyonet's glands in larvae of Diatraea saccharalis Fabricius (Lepidoptera: Pyralidae)
(2004-08-01) Victoriano, Eliane ; Gregório, Elisa A. ; Universidade Estadual Paulista (UNESP)
The Lyonet's gland is found in Lepidoptera larvae, close to the excretory duct of the silk gland. The role played by this gland is still uncertain. This work aims to describe the ultrastructure of the Lyonet's gland in Diatraea saccharalis larvae, offering suggestions regarding its possible function. The insects were reared under laboratory-controlled conditions. The glands were conventionally prepared for transmission (TEM) and scanning (SEM) electron microscopy. SEM showed that Lyonet's glands are paired small structures located in the ventral side of the head. They are composed by clustered long cells resembling leaves. Under TEM observations, each cell is surrounded by a thin basal lamina and contains large stellate nucleus. The cytoplasm presents large and empty canaliculi with small microvilli. The basal plasma membrane forms numerous infoldings where numerous and well-developed mitochondria are concentrated. The cytoplasmic membrane system is poorly developed. Our ultrastructural results suggest that the Lyonet's gland in D. saccharalis larvae may be involved in the uptake of small molecules from the hemolymph; no morphological evidences of macromolecules synthesis and secretion were noticed. The detection of nerve fibers in the gland suggest a neural control for the glandular cell function.
Spherites in the midgut epithelial cells of the sugarcane borer parasitized by Cotesia flavipes
(2008-05-15) Pinheiro, Daniela De Oliveira ; Conte, Hélio ; Gregório, Elisa Aparecida ; Universidade Estadual Paulista (UNESP) ; Universidade Estadual de Maringá (UEM)
Diatraea saccharalis, the main pest of sugarcane, has been controlled by Cotesia flavipes. Very little is known about the effect of parasitism on the host organs, including the midgut. The Lepidoptera midgut epithelium is composed of columnar, goblet, regenerative, and endocrine cells. Spherites have been described in columnar and regenerative cells of several Lepidoptera species, and presented a lot of functional meaning. We identified spherites in the midgut epithelial cells of non-parasitized D. saccharalis larvae analyzed the effect of parasitism on spherite morphology and distribution along the length of the midgut. Midgut fragments of both non-parasitized and parasitized larvae were processed for transmission electron microscopy. All the midgut epithelial cells showed spherites, but they were not preferentially located in a particular part of the cells. Parasitized larvae had more spherites, mainly in the columnar cells, than non-parasitized larvae. This observation was associated with an ionic imbalance within the insect host. Spherites were more abundant in the anterior midgut region than in other regions, which suggests that this region is involved in ion transport by intracellular and/or paracellular route. The morphological variability of spherites in the cells of parasitized larvae was related to the developmental stages of these structures.
Tissue alterations in the Guinea pig lateral prostate following antiandrogen flutamide therapy
(2004-06-07) Cordeiro, Renato Simões ; Scarano, Wellerson Rodrigo ; Góes, Rejane Maira ; Taboga, Sebastião Roberto ; Universidade Estadual de Campinas (UNICAMP) ; Universidade Estadual Paulista (UNESP)
The flutamide antiandrogenic effects on the Guinea pig male prostate morphology in puberal, post-puberal and adult ages were evaluated in the present study. Daily-treated group animals received flutamide subcutaneous injection at a dose of 10 mg/Kg body weight for 10 days. The control group animals received a pharmacological vehicle under the same conditions. The lateral prostate was removed, fixed and processed for light and transmission electron microscopy. The results revealed an increase of the acinus diameter in the treated puberal animals and straitness in the stromal compartment around the acini. The epithelial cells exhibited cubic phenotype. In the post-puberal and adult animals, a decrease of the acinus diameter was observed. as well as an increase of the smooth muscle layer and presence of the folds at epithelium. The ultrastructural evaluation of the secretory cells in the treated group demonstrated endomembrane enlargement, mainly in the rough endoplasmic reticulum and Golgi apparatus. In addition, a decrease of the microvilli and alterations in the distribution patterns and density of the stromal fibrillar components were observed. In conclusion, the flutamide treatment exerts tissue effects on the lateral prostate, promoting stroma/epithelium alterations.
Ultrastructure of the ovariole sheath in Diatraea saccharalis (Lepidoptera: Pyralidae)
(2002-09-23) Dos Santos, Daniela Carvalho ; Gregório, Elisa Aparecida ; Universidade Estadual Paulista (UNESP)
The ultrastructure of the ovariole sheath along the Diatraea saccharatis ovariole was studied by scanning and transmission electron microscopy. Each ovariole is surrounded by an epithelial sheath, a tunica propria and scattered lumen cells. These three components of the ovariole sheath show different ultrastructural features along the ovariole, in the germarium or in the vitellarium; these differences are more evident in the epithelial sheath cells. The epithelial sheath is composed by two layers of cells, the external one running longitudinally and the internal one running circularly in the ovariole. These cells, in vitellarium, present cytoplasmic bundles of myofilaments that are arranged parallel to the long axis of the cells; these myofilaments are apparently related to the contraction movements of the follicles within the ovariole. The acellular tunica propria, composed of finely filamentous material, is attached to the adjacent follicle cells by adhesive dense plates. Between the epithelial sheath and the tunica propria there is a population of lumen cells, with morphological features of secretory activity.
Spontaneous germ cell death by apoptosis in epididymis of the adult bat Artibeus lituratus
(1999-12-01) Taboga, S. R. ; De Souza, R. S. ; Dos Santos, D. C. ; Oliani, S. M. ; Universidade Estadual Paulista (UNESP)
Many factors can lead cells to apoptosis during the various stages of cell life. This study was undertaken to characterize germ cell death in the epididymis of the adult Artibeus lituratus by histochemical and immunohistochemical techniques using light microscopy and transmission electron microscopy. The results showed that cells with a nuclear phenotype and ultrastructural characteristics of chromatin compaction were common in apoptosis. The Apoptag test confirmed that the suspected cells were apoptotic. It is suggested that immature germ cells, when released from the germinative epithelium, may be directed towards the epididymis instead of being disposed of in the testicle. Furthermore, intact immature cells can leave the testicle in the initial phases of apoptosis and complete this phenomenon in the epididymis.

Atenção!

Navegar

Submissões Recentes