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Differential ultrastructural changes in tomato hormonal mutants exposed to cadmium

GRATAO, Priscila L.; MONTEIRO, Carolina C.; ROSSI, Monica L.; MARTINELLI, Adriana P.; PERES, Lazaro E. P.; MEDICI, Leonardo O.; LEA, Peter J.; AZEVEDO, Ricardo A.
Fonte: PERGAMON-ELSEVIER SCIENCE LTD Publicador: PERGAMON-ELSEVIER SCIENCE LTD
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.18%
Cadmium (Cd) is a toxic heavy metal, which can cause severe damage to plant development. The aim of this work was to characterize ultrastructural changes induced by Cd in miniature tomato cultivar Micro-Tom (MT) mutants and their wild-type counterpart. Leaves of diageotropica (dgt) and Never ripe (Nr) tomato hormonal mutants and wild-type MT were analysed by light, scanning and transmission electron microscopy in order to characterize the structural changes caused by the exposure to 1 mM CdCl(2). The effect of Cd on leaf ultrastructure was observed most noticeably in the chloroplasts, which exhibited changes in organelle shape and internal organization, of the thylakoid membranes and stroma. Cd caused an increase in the intercellular spaces in Nr leaves, but a decrease in the intercellular spaces in dgt leaves, as well as a decrease in the size of mesophyll cells in the mutants. Roots of the tomato hormonal mutants, when analysed by light microscopy, exhibited alterations in root diameter and disintegration of the epidermis and the external layers of the cortex. A comparative analysis has allowed the identification of specific Cd-induced ultrastructural changes in wild-type tomato, the pattern of which was not always exhibited by the mutants. (C) 2009 Elsevier B.V. All rights reserved.; Fundacao de Amparo Pesquisa do Estado de Sao Paulo (FAPESP)[04/08444-6]; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq-Brazil)

Long term evaluation of morphometric and ultrastructural changes of testes of alloxan-induced diabetic rats

Trindade, Amélia Arcângela Teixeira; Simões, Antônio Caetano Pereira; Silva, Reinaldo José; Macedo, Célia Sperandeo; Spadella, César Tadeu
Fonte: Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia Publicador: Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia
Tipo: Artigo de Revista Científica Formato: 256-265
ENG
Relevância na Pesquisa
46.19%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); PURPOSE: To evaluate in a long term the morphometric and ultrastructural changes in seminiferous tubules (ST) of normal and diabetic rats, and to correlate any changes with animal age and diabetes duration. METHODS: Sixty male Wistar rats, three months-old, were randomly divided into two groups: 30 non-diabetic controls (N) and 30 alloxan untreated diabetic (D). After one, six and 12 months of follow-up or diabetes induction rats were sacrificed and the testes examined. Morphometric measures of the ST were performed by digital imaging analysis. ST ultrastructure was analyzed by transmission electron microscopy. RESULTS: Sustained hyperglycemic state was observed in all diabetic rats throughout the study. Serum testosterone was also significantly decreased in these animals. The diameter, total area, epithelium area and epithelium thickness of ST were lower and tubular density was higher in diabetic animals. Diabetic rats also showed ultrastructural changes compromising the whole testis including germ-, Sertoli-, and Leydig cells, and also the mithocondria and cellular nuclei. Most frequent of these consisted of vacuolization and/or accumulation of lipid droplets and electron dense dark material in cell cytoplasm and/or in membranes...

Histoenzymological and ultrastructural changes in lateral muscle fibers of Oreochromis niloticus (Teleostei: Cichlidae) after local injection of veratrine

Silva Freitas, Erika Maria; Dal Pai Silva, Maeli; Da Cruz-Höfling, Maria Alice
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 525-534
ENG
Relevância na Pesquisa
66.28%
The effects of veratrine have been investigated in mammalian, amphibian, and crustacean muscle, but not in fish. In this work, the action of veratrine was studied in the lateral muscle of the freshwater teleost Oreochromis niloticus after intramuscular injection. Histoenzymological typing and electron microscopy of muscle fibers before and 15, 30, and 60 min after veratrine injection (10 ng/kg fish) were used to indirectly assess the morphological changes and the oxidative and m-ATPase activities. In some cases, muscles were pretreated with tetrodotoxin to determine whether the ultrastructural changes were the result of Na+ channel activation by veratrine. Veratrine altered the metabolism of fibers mainly after 30 min. Oxidative fibers showed decreased NADH-TR activity, whereas that of glycolytic and oxidative-glycolytic type fibers increased. There was no change in the m-ATPase activity of the three fiber types, except at 60 min postveratrine, when a novel fiber type, which showed no reversal after acidic and alkaline preincubations, appeared. Ultrastructural damage involved sarcomeres, myofibrils, and mitochondria, but the T-tubules remained intact. Pretreatment with tetrodotoxin (1 ng/ml) prevented the ultrastructural changes caused by veratrine. These results show that in fish skeletal muscle veratrine produces some effects that are not seen in mammalian muscle.

Mouse extensor digitorum longus and soleus show distinctive ultrastructural changes induced by veratrine

Da Cruz Höfling, M. A.; Dal Pai Silva, M.; Silva Freitas, E. M.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 305-313
ENG
Relevância na Pesquisa
56.08%
We investigated whether veratrine (5 μl, 10 ng/kg) injected into the mouse extensor digitorum longus (EDL) (fast-twitch) and soleus (SOL) (slow-twitch) muscles provokes distinctive ultrastructural disturbances 15, 30 and 60 min later. The mitochondria in SOL were affected earlier (within 15 min) than in EDL. Swelling of the sarcoplasmic reticulum terminal cisternae was more marked in EDL than in SOL and caused distortion of sarcomeres so that fragmentation of myofilaments was more pronounced in EDL. Hypercontracted sarcomeres were seen mainly in SOL and veratrine caused infoldings of the sarcolemma only in this muscle. In both muscles, the T-tubules remained unaffected and by 60 min after veratrine most of the above alterations had reverted to normal. Pretreatment with tetrodotoxin prevented the alterations induced by veratrine. This suggests that most of the alterations resulted from the enhanced influx of Na+ into muscle fibers. These results emphasize the importance of considering the type of muscle when studying the action of myotoxic agents.

Long term evaluation of morphometric and ultrastructural changes of testes of alloxan-induced diabetic rats

Trindade,Amélia Arcângela Teixeira; Simões,Antônio Caetano Pereira; Silva,Reinaldo José; Macedo,Célia Sperandeo; Spadella,César Tadeu
Fonte: Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia Publicador: Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2013 EN
Relevância na Pesquisa
46.19%
PURPOSE: To evaluate in a long term the morphometric and ultrastructural changes in seminiferous tubules (ST) of normal and diabetic rats, and to correlate any changes with animal age and diabetes duration. METHODS: Sixty male Wistar rats, three months-old, were randomly divided into two groups: 30 non-diabetic controls (N) and 30 alloxan untreated diabetic (D). After one, six and 12 months of follow-up or diabetes induction rats were sacrificed and the testes examined. Morphometric measures of the ST were performed by digital imaging analysis. ST ultrastructure was analyzed by transmission electron microscopy. RESULTS: Sustained hyperglycemic state was observed in all diabetic rats throughout the study. Serum testosterone was also significantly decreased in these animals. The diameter, total area, epithelium area and epithelium thickness of ST were lower and tubular density was higher in diabetic animals. Diabetic rats also showed ultrastructural changes compromising the whole testis including germ-, Sertoli-, and Leydig cells, and also the mithocondria and cellular nuclei. Most frequent of these consisted of vacuolization and/or accumulation of lipid droplets and electron dense dark material in cell cytoplasm and/or in membranes...

Myocardial ultrastructural changes during extracorporeal circulation wtih anoxic cardiac arrest and its prevention by coronary perfusion. Experimental study.

Balibrea, J L; Bullon, A; de la Fuente, A; de la Alarcon, A; Fariñas, J; Collantes, P; Gil, M; Gombau, M; Morales, R; Sanchez, F
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /08/1975 EN
Relevância na Pesquisa
46.16%
This experimental work has been carried out with the aim of studying the ultrastructural myocardial changes caused by prolonged anoxic cardiac arrest during cardiopulmonary bypass, and their prevention by means of two different techniques of coronary perfusion--systemic-pressure continuous and low-pressure intermittent perfusion. After 30 minutes of cardiac anoxia, the ultrastructural changes of the myocardial cell were reverted to normal by coronary perfusion; when anoxic cardiac arrest was prolonged up to 60 minutes there was severe myocardial damage, with marked mitochondrial changes and dehiscence of intercalated discs, which persisted in spite of restoring coronary flow. These morphological data were in accordance with the fact that no dog which underwent anoxic cardiac arrest for 60 minutes recovered. Both intermittent and continuous coronary perfusion were effective in preventing anoxic damage; cardiac muscle cells were better preserved by low-pressure intermittent perfusion than by systemic-pressure continuous perfusion, which caused intracellular and intramitochondrial oedema.

Ultrastructural changes in rat adipomusculocutaneous flaps during warm ischaemic storage and reperfusion.

Nishikawa, H.; Fryer, P. R.; Sarathchandra, P.; Manek, S.; Charlett, A.; Green, C. J.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /02/1993 EN
Relevância na Pesquisa
46.22%
Electron microscopy (EM) was used to evaluate ultrastructural changes in adipomusculocutaneous rat flaps which had been stored for 0, 2, 4, 6 and 8 hours under normothermic conditions (37 degrees C). The effects of treatment with desferrioxamine (DFX) or hypertonic citrate flush (HCA), prior to 4 hours of storage, were compared to untreated flaps which had been stored for 4 hours. Ultrastructural changes caused by 30 minutes of reperfusion, were also studied. Most ultrastructural alterations occurred between 2 and 4 hours of warm storage and there were further changes in some cells after short periods of reperfusion. DFX decreased smooth muscle damage and HCA protected adipocytes but neither of these agents preserved endothelial cells. These studies indicated that free radical-dependent and independent mechanisms were both involved in events which led to flap necrosis after periods of warm storage and reperfusion.

Ultrastructural changes of mouse brain neurons infected with Japanese encephalitis virus.

Hase, T.; Summers, P. L.; Dubois, D. R.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /08/1990 EN
Relevância na Pesquisa
46.18%
Ultrastructural changes of mouse brain neurons infected intracerebrally with Japanese encephalitis (JE) virus were studied. JE virus selectively infected the neurons, causing ultrastructural changes in association with viral replication in the cellular secretory system, principally involving rough endoplasmic reticulum (RER) and the Golgi apparatus. In the early phase of infection, RER of infected neurons showed hypertrophic changes, containing assembling virions within its dilated cisternae. In the later phase, the RER became cystic and degenerative and dissolved into the cytoplasm. The Golgi apparatus also contained in its saccules multiple virions, presumably transported from the RER cisternae, which were then released into the cytoplasm within coated vesicles for secretory-type exocytosis. In the process, the Golgi apparatus also fragmented and degenerated through vesiculation, vacuolation, and dispersion. Thus, the JE virus infection of neurons resulted in obliteration of RER and the Golgi apparatus, leaving behind the rarefied cytoplasm devoid of these organelles. However, destruction of the neurons themselves was not prominent and infected neurons in the later phase of infection showed some regenerative changes of these membranous organelles. The cause of death of infected animals...

ULTRASTRUCTURAL BASES FOR METABOLICALLY LINKED MECHANICAL ACTIVITY IN MITOCHONDRIA : I. Reversible Ultrastructural Changes with Change in Metabolic Steady State in Isolated Liver Mitochondria

Hackenbrock, Charles R.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 01/08/1966 EN
Relevância na Pesquisa
46.31%
By means of a new "quick-sampling" method, micropellets of mouse liver mitochondria were rapidly prepared for electron microscopy during the recording of steady state metabolism. Reversible ultrastructural changes were found to accompany change in metabolic steady states. The most dramatic reversible ultrastructural change occurs when ADP is added to systems in which only phosphate acceptor is deficient, i.e., during the State IV to State III transition as defined by Chance and Williams. After 15 min in State IV, mitochondria display an "orthodox" ultrastructural appearance as is usually observed after fixation within intact tissue. On transition to State III, a dramatic change in the manner of folding of the inner membrane takes place. In addition, the electron opacity of the matrix increases as the volume of the matrix decreases, but total mitochondrial volume does not appear to change during this transition. This conformation is called "condensed." Isolated mitochondria were found to oscillate between the orthodox and condensed conformations during reversible transitions between State III and State IV. Various significant ultrastructural changes in mitochondria also occur during transitions in other functional states, e.g., when substrate or substrate and acceptor is made limiting. Internal structural flexibility is discussed with respect to structural and functional integrity of isolated mitochondria. Reversible changes in the manner of folding of the inner membrane and in the manner of packing of small granules in the matrix as respiration is activated by ADP represent an ultrastructural basis for metabolically linked mechanical activity in tightly coupled mitochondria.

Early and late immunohistochemical and ultrastructural changes associated with functional impairment of the lachrymal gland following external beam radiation

Hakim, Samer G; Schroder, Christina; Geerling, Gerd; Lauer, Isabel; Wedel, Thilo; Kosmehl, Hartwig; Driemel, Oliver; Jacobsen, Hans-Christian; Trenkle, Thomas; Hermes, Dirk; Sieg, Peter
Fonte: Blackwell Science Inc Publicador: Blackwell Science Inc
Tipo: Artigo de Revista Científica
Publicado em /02/2006 EN
Relevância na Pesquisa
46.28%
The aim of this study was to investigate scintigraphic, immunohistological and ultrastructural changes associated with radiation-induced dysfunction of the lachrymal gland in an established experimental animal model. Ten rabbits were randomized into two groups and used for the study; in the control as well as experimental group, the Schirmer-test, lachrymal gland scintigraphy, and immunohistological and ultrastructural investigations were carried out prior to irradiation and 72 h as well as 1 month after single-dose irradiation with 15 Gy. Seventy-two hours after irradiation, secretion reduction evaluated by the Schirmer-test was evident. At this phase, we could observe a decrease in the expression of α-SMA and a re-distribution of tenascin-C matrix. Ultrastructural changes of acinar and myoepithelial cells were noticed; simultaneously, disturbance in the primary 99mTcO4– uptake as well as significant reduction of the lachrymal ejection fraction was assessed scintigraphically. These changes were still evident 1 month following irradiation but became less intensive. Single-dose irradiation with 15 Gy implicates a functional impairment of the lachrymal gland, which is associated with early immunohistological and ultrastructural alterations. These changes may represent objective surrogate parameters for radiogenic dysfunction and prerequisites for further investigations on radioprotection of lachrymal glands during radiotherapy of the periorbital region.

Effect of acute exercise stress in cardiac hypertrophy: I. correlation of regional blood flow and qualitative ultrastructural changes.

Singh, S.; White, F. C.; Bloor, C. M.
Fonte: Yale Journal of Biology and Medicine Publicador: Yale Journal of Biology and Medicine
Tipo: Artigo de Revista Científica
Publicado em //1980 EN
Relevância na Pesquisa
46.18%
Ultrastructural myocardial cell changes were determined in eight miniswine after the development of pressure-overload hypertrophy induced by supra-valvular aortic constriction. Four miniswine served as control animals. Regional myocardial blood flows were measured at rest and during exercise stress with radioactive microspheres after two days and one month of aortic constriction. Exercise stress, causing the heart rate to increase to 85 percent of its maximum, was imposed twice weekly for 7 minutes on four pressure-overloaded animals and the four control animals to elicit differences between the control and experimental groups that might not occur at rest. After one month of pressure overload the swine were killed and myocardial samples were processed for electron microscopy. Ultrastructural changes similar to those in hypertrophied hearts were present throughout the left ventricular walls of the pressure-overloaded animals. Other changes consistent with ischemic injury were present in the subendocardial regions of pressure-overloaded animals subjected to exercise stress. These changes included disorganization of myofibrils, disintegration and broadening of Z-bands, swelling and aggregation of mitochondria, electron-dense deposits in mitochondria...

Ultrastructural Changes of Corpus Luteum after Ovarian Stimulation at Implantation Period

BeigiBoroujeni, Mandana; Beigi Boroujeni, Nasim; Salehnia, Mojdeh; Marandi, Elahe; Beigi Boroujeni, Masoud
Fonte: Pasteur Institute of Iran Publicador: Pasteur Institute of Iran
Tipo: Artigo de Revista Científica
Publicado em /01/2012 EN
Relevância na Pesquisa
46.25%
Background: To achieve multiple oocytes for in vitro fertilization, ovulation induction is induced by gonadotropins; however, it has several effects on oocytes and embryo quality and endometrium receptivity. The aim of this study was to assess ultrastructural changes of corpus luteum after ovarian induction using human menopausal gonadotropin (HMG) and human chorionic gonadotropin (HCG) during luteal phase at implantation period. Methods: Female NMRI mice (6-8 weeks) were divided into control and stimulated groups. In the control group, the mice were rendered pseudopregnant and in the ovarian induction group, the mice were rendered pseudopregnant after the ovarian induction. The samples were obtained from the ovary in each group at the same time during luteal phase at implantation period. Ultrastructural changes were assessed using electron microscopy study. Results: Our results displayed some identifiable changes in ultrastructure of corpus luteum in ovarian induction group. These changes included enhancement of the apoptosis and intercellular space, whereas the angiogenesis was decreased. The findings indicated a decline in organelle density in the cytoplasm of ovarian induction, such as mitochondria, endoplasmic reticulum and polyribosome. Furthermore...

Ultrastructural Changes of Airway in Murine Models of Allergy and Diet-Induced Metabolic Syndrome

Leishangthem, Geeta Devi; Mabalirajan, Ulaganathan; Singh, Vijay Pal; Agrawal, Anurag; Ghosh, Balaram; Dinda, Amit Kumar
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
Publicado em 10/09/2013 EN
Relevância na Pesquisa
46.16%
Studying ultrastructural changes could reveal novel pathophysiology of obese-asthmatic condition as existing concepts in asthma pathogenesis are based on the histological changes of the diseased airway. While asthma is defined in functional terms, the potential of electron microscopy (EM) in providing cellular and subcellular detail is underutilized. With this view, we have performed transmission EM in the lungs from allergic mice that show key features of asthma and high-fat- or high-fructose-fed mice that mimicked metabolic syndrome to illustrate the ultrastructural changes. The primary focus was epithelial injury and metaplasia, which are cardinal features of asthma and initiate airway remodeling. EM findings of the allergically inflamed mouse lungs correlate with known features of human asthma such as increased mitochondria in airway smooth muscle, platelet activation and subepithelial myofibroblasts. Interestingly, we found a clear and unambiguous evidence to suggest that ciliated cells can become goblet cells using immunoelectron microscopy. Additionally, we show for the first time the stressed mitochondria in the bronchial epithelia of high-fat- or high-fructose-fed mice even without allergen exposure. These results may stimulate interest in using EM in understanding novel pathological mechanisms for different subtypes of asthma including obese asthma.

Alloxan-Induced Diabetes Causes Morphological and Ultrastructural Changes in Rat Liver that Resemble the Natural History of Chronic Fatty Liver Disease in Humans

Lucchesi, Amanda Natália; Cassettari, Lucas Langoni; Spadella, César Tadeu
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.16%
Purpose. This study evaluated the long-term effects of alloxan-induced diabetes in rat liver. Methods. Thirty nondiabetic control rats (NC) and 30 untreated diabetic (UD) rats were divided into three subgroups sacrificed after 6, 14, or 26 weeks. Clinical and laboratory parameters were assessed. Fresh liver weight and its relationship with body weight were obtained, and liver tissue was analyzed. Results. UD rats showed sustained hyperglycemia, high glycosylated hemoglobin, and low plasma insulin. High serum levels of AST and ALT were observed in UD rats after 2 weeks, but only ALT remained elevated throughout the experiment. Fresh liver weight was equal between NC and UD rats, but the fresh liver weight/body weight ratio was significantly higher in UD rats after 14 and 26 weeks. UD rats showed liver morphological changes characterized by hepatic sinusoidal enlargement and micro- and macrovesicular hepatocyte fatty degeneration with progressive liver structure loss, steatohepatitis, and periportal fibrosis. Ultrastructural changes of hepatocytes, such as a decrease in the number of intracytoplasmic organelles and degeneration of mitochondria, rough endoplasmic reticulum, and nuclei, were also observed. Conclusion. Alloxan-induced diabetes triggered liver morphological and ultrastructural changes that closely resembled human disease...

Ultrastructural changes in the oviduct of laying hen during laying cycle

Chousalkar, K.; Roberts, J.
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
Publicado em //2008 EN
Relevância na Pesquisa
46.16%
The ultrastructural changes occurring in the fully functional oviduct of Isa Brown laying hens were studied during various stages of the laying cycle. Hens were killed at different positions of the egg in the oviduct. The oviduct was lined by ciliated and non-ciliated cells (also referred to as granular cells). The granular cells in the infundibulum contributed to secretion during egg formation, whereas ciliated cells showed little evidence of secretion. Ultrastructural changes were recorded in the granular and glandular cells of the distal infundibulum. In the magnum, the surface ultrastructure revealed glandular openings associated with the ciliated and granular cells. Cyclic changes were recorded in the glandular cells of the magnum. With respect to the three observed types of glands, the structure of gland type A and C cells varied at different egg positions in the oviduct, whereas type B cells represented a different type of gland cell containing amorphous secretory granules. The surface epithelium of the isthmus was also lined by mitochondrial cells. Two types of glandular cell (types 1 and 2) were recorded in the isthmus during the laying cycle. Intracisternal granules were found in type 2 cells of the isthmus. A predominance of glycogen particles occurred in the tubular shell gland. The granular cells in the shell gland contain many vacuoles. During egg formation...

Chronic hypoxia induced ultrastructural changes in the rat adrenal zona glomerulosa

Lorente, M.; Mirapeix, R.M.; Miguel, M.; Longmei, W.; Volk, D.; Cervós-Navarro, J.
Fonte: Murcia : F. Hernández Publicador: Murcia : F. Hernández
Tipo: Artigo de Revista Científica Formato: application/pdf
ENG
Relevância na Pesquisa
46.19%
The adrenal cortex plays an important role in adaptation to various forms of stress, including hypoxia. While physiological changes in the aldosterone metabolism during hypoxia have been extensively described, few studies have focused on the morphological changes in the adrenal glands under chronic hypoxia. We studied the ultrastructure of the z o n a g l o m e ru l o s a of 6-month-old Wistar rats exposed to chronic normobaric hypoxia. Animals were divided into two groups: control (n=12) and hypoxic (n=12). In this latter group, the animals were kept at 7% O2 concentration after a gradual adaptation (21, 15, 12, 10, 8, 7 vol% O2 ). The duration of the study was 112 days. In comparison with normoxic rats, body weight and adrenal gland weight of hypoxic animals was significantly reduced by 18.5% (p=0.006) and 14.7% (p=0.001) respectively. The thickness of the z o n a glomerulosa decreased due to atrophy of cells. The main ultrastructural changes observed were: 1) a decrease in, or complete elimination of, lipid droplet content; 2) a marked increase in lysosome number; and 3) the presence of giant mitochondria. Our findings show that rats fail to adapt to severe chronic hypoxia. The ultrastructural changes in the zona g l o m e ru l o s a found in the present study could reflect changes in the aldosterone pathway.

Ultrastructural changes in the lungs of neonatal rats intratracheally inoculated with meconium

Martínez Burnes, J.; Lopez, A.; Wright, Glenda M.; Ireland, William P.; Wadowska, D.W.; Dobbin, G.V.
Fonte: Murcia : F. Hernández Publicador: Murcia : F. Hernández
Tipo: Artigo de Revista Científica Formato: application/pdf
ENG
Relevância na Pesquisa
46.28%
Meconium aspiration syndrome has been for many years an important cause of neonatal respiratory distress in newborn babies and sporadically reported in animals. This investigation was designed to study the ultrastructural and morphometric changes in the lungs of neonatal rats following the intratracheal inoculation of meconium. Seven-day-old Fischer-344 rats (n = 24) were randomly allocated in two groups. One group was intratracheally inoculated with saline solution and the second group received homologous meconium. Neonates were euthanatized at 1, 3 and 7 postinoculation days (PID) and lungs were examined by light and electron microscopy. Saline solution did not induce any ultrastructural changes in the lung. In contrast, meconium induced deciliation, recruitment of neutrophils and pulmonary alveolar macrophages to the bronchoalveolar space, intravascular sequestration of neutrophils and aggregation of platelets at PID 1 and 3. Other ultrastructural changes at PID 1 and 3 included interstitial edema and escape of red cells and fibrin into the alveolar space and interstitium. Interstitial edema and sequestration of neutrophils were responsible for the significant increase in thickness of alveolar septa. At PID 7 there was hyperplasia and enlargement of type II pneumocytes as well as interstitial proliferation of mesenchymal cells with intra-alveolar fibrosis. It was concluded that intratracheal inoculation of meconium in neonatal rats induces acute ultrastructural changes followed by a reparative response.

Alloxan-Induced Diabetes Causes Morphological and Ultrastructural Changes in Rat Liver that Resemble the Natural History of Chronic Fatty Liver Disease in Humans

Lucchesi, Amanda Natalia; Cassettari, Lucas Langoni; Spadella, Cesar Tadeu
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica Formato: 11
ENG
Relevância na Pesquisa
46.16%
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Purpose. This study evaluated the long-term effects of alloxan-induced diabetes in rat liver. Methods. Thirty nondiabetic control rats (NC) and 30 untreated diabetic (UD) rats were divided into three subgroups sacrificed after 6, 14, or 26 weeks. Clinical and laboratory parameters were assessed. Fresh liver weight and its relationship with body weight were obtained, and liver tissue was analyzed. Results. UD rats showed sustained hyperglycemia, high glycosylated hemoglobin, and low plasma insulin. High serum levels of AST and ALT were observed in UD rats after 2 weeks, but only ALT remained elevated throughout the experiment. Fresh liver weight was equal between NC and UD rats, but the fresh liver weight/body weight ratio was significantly higher in UD rats after 14 and 26 weeks. UD rats showed liver morphological changes characterized by hepatic sinusoidal enlargement and micro- and macrovesicular hepatocyte fatty degeneration with progressive liver structure loss, steatohepatitis, and periportal fibrosis. Ultrastructural changes of hepatocytes, such as a decrease in the number of intracytoplasmic organelles and degeneration of mitochondria...

Early ultrastructural changes of antral mucosa with aspirin in the absence of Helicobacter pylori.

McCarthy, C J; Sweeney, E; O'Morain, C
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /11/1995 EN
Relevância na Pesquisa
46.22%
AIMS--To describe the ultrastructural changes that occur in human antral mucosa following direct application of aspirin in volunteers without Helicobacter pylori infection. METHODS--Ten healthy male volunteers without H pylori infection underwent three consecutive endoscopies (at zero, one and five hours). At the first endoscopy, two biopsy specimens were obtained (one for histology and the other for electron microscopy (EM)). At subsequent endoscopies, a single biopsy specimen was obtained for EM. A 50 ml solution of aspirin (concentration 3 mg/ml) was applied to the antral mucosa at the first endoscopy in five subjects; the other five subjects received 50 ml distilled water (placebo). RESULTS--The ultrastructural appearance of the first biopsy specimen in all subjects and subsequent biopsy specimens in the placebo treated subjects was normal. The aspirin treated group had evidence of intercellular oedema, widening of capillary fenestrae, rupturing of apical membranes, and dilatation of endoplasmic reticulum and mitochondria after one hour; these changes were more marked at five hours. Tight junctions were maintained. CONCLUSION--This is the first study to describe the early ultrastructural changes in antral mucosa induced by aspirin in subjects without H pylori infection.

A Translational Murine Model of Sub-Lethal Intoxication with Shiga Toxin 2 Reveals Novel Ultrastructural Findings in the Brain Striatum

Tironi Farinati, Alicia Carla Flavia; Geoghegan, Patricia A.; Cangelosi, Adriana; Pinto, Alipio; Loidl, Cesar Fabian; Goldstein, Jorge
Fonte: Public Library Of Science Publicador: Public Library Of Science
Tipo: info:eu-repo/semantics/article; info:ar-repo/semantics/artículo; info:eu-repo/semantics/publishedVersion Formato: application/pdf
ENG
Relevância na Pesquisa
56.08%
Infection by Shiga toxin-producing Escherichia coli causes hemorrhagic colitis, hemolytic uremic syndrome (HUS), acute renal failure, and also central nervous system complications in around 30% of the children affected. Besides, neurological deficits are one of the most unrepairable and untreatable outcomes of HUS. Study of the striatum is relevant because basal ganglia are one of the brain areas most commonly affected in patients that have suffered from HUS and since the deleterious effects of a sub-lethal dose of Shiga toxin have never been studied in the striatum, the purpose of this study was to attempt to simulate an infection by Shiga toxin-producing E. coli in a murine model. To this end, intravenous administration of a sub-lethal dose of Shiga toxin 2 (0.5 ηg per mouse) was used and the correlation between neurological manifestations and ultrastructural changes in striatal brain cells was studied in detail. Neurological manifestations included significant motor behavior abnormalities in spontaneous motor activity, gait, pelvic elevation and hind limb activity eight days after administration of the toxin. Transmission electron microscopy revealed that the toxin caused early perivascular edema two days after administration, as well as significant damage in astrocytes four days after administration and significant damage in neurons and oligodendrocytes eight days after administration. Interrupted synapses and mast cell extravasation were also found eight days after administration of the toxin. We thus conclude that the chronological order of events observed in the striatum could explain the neurological disorders found eight days after administration of the toxin.; Fil: Tironi Farinati...