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New approaches and potential treatments for dry age-related macular degeneration; Novas abordagens e tratamentos potenciais da forma seca da degeneração macular relacionada à idade

Damico, Francisco Max; Gasparin, Fabio; Scolari, Mariana Ramos; Pedral, Lycia Sampaio; Takahashi, Beatriz Sayuri
Fonte: Conselho Brasileiro de Oftalmologia Publicador: Conselho Brasileiro de Oftalmologia
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.61%
Emerging treatments for dry age-related macular degeneration (AMD) and geographi c atrophy focus on two strategies that target components involved in physiopathological pathways: prevention of photoreceptors and retinal pigment epithelium loss (neuroprotection induction, oxidative damage prevention, and visual cycle modification) and suppression of inflammation. Neuroprotective drugs, such as ciliary neurotrophic factor, brimonidine tartrate, tandospirone, and anti-amyloid β antibodies, aim to prevent apoptosis of retinal cells. Oxidative stress and depletion of essential micronutrients are targeted by the Age-Related Eye Disease Study (AREDS) formulation. Visual cycle modulators reduce the activity of the photoreceptors and retinal accumulation of toxic fluorophores and lipofuscin. Eyes with dry age-related macular degeneration present chronic inflammation and potential treatments include corticosteroid and complement inhibition. We review the current concepts and rationale of dry age-related macular degeneration treatment that will most likely include a combination of drugs targeting different pathways involved in the development and progression of age-related macular degeneration.

Degeneration of salivary glands of males of the tick Rhipicephalus sanguineus (Latreille, 1806) (Acari, Ixodidae)

Scopinho Furquim, Karim Christina; Bechara, Gervasio Henrique; Camargo Mathias, Maria Izabel
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 325-335
ENG
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36.7%
The present study examined the salivary glands of Rhipicephalus sanguineus males at days 0, 3, and 7 post-detachment from the host. Degeneration of this organ occurred in the three stages and it advanced as time away from the host progressed. Thus, characteristics of degeneration were more prominent in males at day 7 post-detachment than in males at day 0 post-detachment. In males at day 0 post-detachment, type I acini were intact; while in other stages these acini exhibited signs of degeneration. In type 11 acini of individuals at day 0 post-detachment, cells a, c1-c5, c8, and indeterminate were identified. Only c I and c8 were intact. The remaining cell types were undergoing degeneration, as well as all cells d-f in type III acini, and all g in type IV acini.In males at day 3 post-detachment from the host, all cells (a, c1-c5, c8 and indeterminate) of type 11 acini, cells d and e in type III acini, and g in type IV were undergoing degeneration. In some Indeterminate acini, the boundaries of cells still could be distinguished, while in others, only a cytoplasmic mass was observed. At day 3 post-detachment, apoptotic bodies were present.In males at day 7 post-detachment from the host, the degeneration process progressed. All cells a...

Influencia de bloqueadores de canais de calcio no processo de degeneração/regeneração muscular em camundongos ditroficos MDX; The influence iof calcium channel blockers in the process of muscular degeneration/regeneration in mdx mice

Cintia Yuri Matsumura
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 02/06/2008 PT
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A ausência da distrofina em fibras musculares de camundongos mdx e na Distrofia Muscular de Duchenne (DMD) provoca ruptura no sarcolema, aumento no influxo de cálcio e conseqüente degeneração muscular. Neste trabalho verificamos os efeitos dos bloqueadores de canais de cálcio diltiazem e verapamil na degeneração/regeneração do músculo distrófico de camundongos mdx. Camundongos mdx (n=32; 18 dias de vida pós-natal) receberam diariamente injeção intraperitoneal de diltiazem (n=16; 72 mg/kg) ou verapamil (n=16; 25 mg/kg) por 18 dias. Após este período os músculos esternomastóide, diafragma, tibial anterior e coração foram retirados. Animais mdx controle (n=16) foram injetados com solução salina. Ambas drogas diminuíram significativamente os níveis séricos de creatina quinase (mdx tratado com salina: 573±245 U/l, animais tratado com diltiazem: 161±53*U/l e animais tratados com verapamil: 217±57*U/l; média±desvio padrão, *p<0,05 comparados a animais tratados com salina, teste t de Student). A quantificação de cálcio total, por espectrômetro de emissão óptica em plasma, foi 173-475% maior em músculos do mdx comparado a músculos de animais controles não-distróficos C57Bl/10. Verapamil e diltiazem reduziram a concentração de cálcio total apenas no diafragma (diltiazem: 229 mg de cálcio/kg versus salina: 295mg de cálcio/kg; p=0...

Comparison of the original Amsler grid with the preferential hyperacuity perimeter for detecting choroidal neovascularization in age-related macular degeneration

Isaac,David Leonardo Cruvinel; Ávila,Marcos Pereira de; Cialdini,Arnaldo Pacheco
Fonte: Conselho Brasileiro de Oftalmologia Publicador: Conselho Brasileiro de Oftalmologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2007 EN
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36.61%
PURPOSE: To compare the preferential hyperacuity perimeter (Preview PHP; Carl Zeiss Meditec, Dublin, CA) with the original Amsler grid in the detection of choroidal neovascularization (CNV) in patients with age-related macular degeneration (AMD). METHODS: Patients were classified into groups, based on the severity of the age-related macular degeneration and underwent preferential hyperacuity perimeter and Amsler grid testing. High sensitivity and or high specificity of a method were defined as the observation of at least 80% of each one the parameters. RESULTS: Sixty-five patients (65 eyes) were analyzed statistically. The sensitivity of detection of choroidal neovascularization was 70% by the Amsler grid and 90% by the preferential hyperacuity perimeter and the specificity of the Amsler grid was 85.5% and that of the preferential hyperacuity perimeter 81.8%. CONCLUSIONS: The preferential hyperacuity perimeter has greater sensitivity than the Amsler grid in the detection of choroidal neovascularization among patients over 50 years of age and is a promising method for monitoring patients with age-related macular degeneration. Although the original Amsler grid is less sensitive, it is a portable method, not expensive, accessible and presents reasonable sensitivity and high specificity in the diagnosis of choroidal neovascularization. Its use can be recommended for self-monitoring in patients with age-related macular degeneration as an alternative to preferential hyperacuity perimeter and when this method is not available.

Prevalence of age-related macular degeneration in Japanese immigrants and their descendants living in Londrina (PR) - Brazil

Oguido,Ana Paula Miyagusko Taba; Casella,Antonio Marcelo Barbante; Matsuo,Tiemi; Ramos Filho,Eduardo Henrique de Freitas; Berbel,Rodrigo; Silva,Ricardo Montanheiro Alcântara
Fonte: Conselho Brasileiro de Oftalmologia Publicador: Conselho Brasileiro de Oftalmologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2008 EN
Relevância na Pesquisa
36.72%
PURPOSE: To determine the prevalence of early and late-stage age-related macular degeneration (ARMD) and its association with risk factors such as age, gender, smoking, body mass index, hypertension and diabetes history, cataracts and pseudophakia. Design: Population-based cross-sectional study in an elderly Japanese-Brazilian population from Londrina (Paraná, Brazil). METHODS: The study included 483 (80.5%) of the 600 registered members of a local association for Japanese immigrants and their descendants, aged 60 years and up. The presence of early and late-stage age-related macular degeneration was determined using the standard protocol and the international classification system. RESULTS: The mean age of the study subjects was 71 years. The overall prevalence of age-related macular degeneration was 15.1% (CI 95%; 12-18.7). The prevalence of early-stage age-related macular degeneration was 13.8% (CI 95%; 10.9-17.3), geographic atrophy was present in 0.4% and neovascular age-related macular degeneration in 0.8%. Age-related macular degeneration was significantly (p=0.004) and linearly (p=0.001) associated with age. CONCLUSION: Our study population displays a prevalence of early and late-stage age-related macular degeneration and component lesions similar to those of other Western countries...

New approaches and potential treatments for dry age-related macular degeneration

Damico,Francisco Max; Gasparin,Fabio; Scolari,Mariana Ramos; Pedral,Lycia Sampaio; Takahashi,Beatriz Sayuri
Fonte: Conselho Brasileiro de Oftalmologia Publicador: Conselho Brasileiro de Oftalmologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2012 EN
Relevância na Pesquisa
36.61%
Emerging treatments for dry age-related macular degeneration (AMD) and geographi c atrophy focus on two strategies that target components involved in physiopathological pathways: prevention of photoreceptors and retinal pigment epithelium loss (neuroprotection induction, oxidative damage prevention, and visual cycle modification) and suppression of inflammation. Neuroprotective drugs, such as ciliary neurotrophic factor, brimonidine tartrate, tandospirone, and anti-amyloid β antibodies, aim to prevent apoptosis of retinal cells. Oxidative stress and depletion of essential micronutrients are targeted by the Age-Related Eye Disease Study (AREDS) formulation. Visual cycle modulators reduce the activity of the photoreceptors and retinal accumulation of toxic fluorophores and lipofuscin. Eyes with dry age-related macular degeneration present chronic inflammation and potential treatments include corticosteroid and complement inhibition. We review the current concepts and rationale of dry age-related macular degeneration treatment that will most likely include a combination of drugs targeting different pathways involved in the development and progression of age-related macular degeneration.

Approach of Turkish ophthalmologists to micronutrition in age-related macular degeneration

Şahin,Muhammed; Yüksel,Harun; Şahin,Alparslan; Cingü,Abdullah Kürşat; Türkcü,Fatih Mehmet; Özkurt,Zeynep Gürsel; Çaça,İhsan
Fonte: Conselho Brasileiro de Oftalmologia Publicador: Conselho Brasileiro de Oftalmologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2015 EN
Relevância na Pesquisa
36.61%
Purpose: To evaluate the knowledge and behaviors of ophthalmologists in Turkey concerning micronutrition support in patients with age related macular degeneration (ARMD). Methods: This study involved 1,845 ophthalmologists. A scientific poll was sent to all participants by email. The survey covered the following: demographic features, subspecialty knowledge about micronutrition preference for prescribing micronutrition to age related macular degeneration patients, and the reason for this preference. If a participant indicated that he or she prescribed micronutrition, the participant was also asked to indicate the source of the treatment and supplemental treatments. Results: Of 1,845 ophthalmologists, 249 responded to the survey. Of the respondents, 9% (22) never, 43% (107) sometimes, 37% (92) frequently, and 11% (27) always used micronutrition. The most frequent prescribing subgroup was general ophthalmology (22%), followed by the retina-uvea subspecialty (13.9%). The micronutrition prescribing ratio was 54.8% in retina-uvea specialists when the "frequent" and "always" responses were combined. There was no statistically significant difference between subgroups with respect to prescribing micronutrition. Among the ophthalmologists prescribing micronutrition...

Experimental model of intervertebral disc degeneration by needle puncture in Wistar rats

Issy,A.C.; Castania,V.; Castania,M.; Salmon,C.E.G.; Nogueira-Barbosa,M.H.; Bel,E. Del; Defino,H.L.A.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2013 EN
Relevância na Pesquisa
36.68%
Animal models of intervertebral disc degeneration play an important role in clarifying the physiopathological mechanisms and testing novel therapeutic strategies. The objective of the present study is to describe a simple animal model of disc degeneration involving Wistar rats to be used for research studies. Disc degeneration was confirmed and classified by radiography, magnetic resonance and histological evaluation. Adult male Wistar rats were anesthetized and submitted to percutaneous disc puncture with a 20-gauge needle on levels 6-7 and 8-9 of the coccygeal vertebrae. The needle was inserted into the discs guided by fluoroscopy and its tip was positioned crossing the nucleus pulposus up to the contralateral annulus fibrosus, rotated 360° twice, and held for 30 s. To grade the severity of intervertebral disc degeneration, we measured the intervertebral disc height from radiographic images 7 and 30 days after the injury, and the signal intensity T2-weighted magnetic resonance imaging. Histological analysis was performed with hematoxylin-eosin and collagen fiber orientation using picrosirius red staining and polarized light microscopy. Imaging and histological score analyses revealed significant disc degeneration both 7 and 30 days after the lesion...

Gene expression profile analysis of human intervertebral disc degeneration

Chen,Kai; Wu,Dajiang; Zhu,Xiaodong; Ni,Haijian; Wei,Xianzhao; Mao,Ningfang; Xie,Yang; Niu,Yunfei; Li,Ming
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2013 EN
Relevância na Pesquisa
36.61%
In this study, we used microarray analysis to investigate the biogenesis and progression of intervertebral disc degeneration. The gene expression profiles of 37 disc tissue samples obtained from patients with herniated discs and degenerative disc disease collected by the National Cancer Institute Cooperative Tissue Network were analyzed. Differentially expressed genes between more and less degenerated discs were identified by significant analysis of microarray. A total of 555 genes were significantly overexpressed in more degenerated discs with a false discovery rate of < 3%. Functional annotation showed that these genes were significantly associated with membrane-bound vesicles, calcium ion binding and extracellular matrix. Protein-protein interaction analysis showed that these genes, including previously reported genes such as fibronectin, COL2A1 and f-catenin, may play key roles in disc degeneration. Unsupervised clustering indicated that the widely used morphology-based Thompson grading system was only marginally associated with the molecular classification of intervertebral disc degeneration. These findings indicate that detailed, systematic gene analysis may be a useful way of studying the biology of intervertebral disc degeneration.

Thickness of the ligamentum flavum of the spine and its relationship with disc degeneration

Mattar,Thiago; Costa,Alexandre Barros; Appolonio,Paulo Roberto; Cesar,André Evaristo Marcondes; Rodrigues,Luciano Miller Reis
Fonte: Sociedade Brasileira de Coluna Publicador: Sociedade Brasileira de Coluna
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2014 EN
Relevância na Pesquisa
36.7%
Objective: This study investigates whether the thickening of the ligamentum flavum (LF) is correlated with disc degeneration. Methods: This retrospective study was conducted with 98 patients with chronic low back pain treated in a spinal surgery service between January 2012 and January 2013. All patients underwent magnetic resonance imaging (MRI) and the images were evaluated by a spinal surgeon to measure the thickness of the LF and evaluate the degree of disc degeneration by the Pfirrmann grading system, according to the spinal levels (L3 -L4, L4-L5, L5-S1). An association was sought between LF hypertrophy and disc degeneration, age, sex and disc height. Results: The mean age of the patients was 53.6 years, and the majority were women (59.2%). The thickness of the LF and disc height varied according to the spinal level, the greatest LF thickness being found between L4-L5, and the greatest disc height at L5-S1. Women had statistically thicker ligaments in L3/L4 than men. The degree of disc degeneration was inversely correlated with the height at all the levels evaluated, i.e., the greater the degree of degeneration, the lower the disc height. Conclusions: The thickening of LF is not related to disc height or degree of disc degeneration. Therefore...

Wallerian-like axonal degeneration in the optic nerve after excitotoxic retinal insult: an ultrastructural study

Saggu, S.; Chotaliya, H.; Blumbergs, P.; Casson, R.
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
Publicado em //2010 EN
Relevância na Pesquisa
36.68%
BACKGROUND: Excitotoxicity is involved in the pathogenesis of a number neurodegenerative diseases, and axonopathy is an early feature in several of these disorders. In models of excitotoxicity-associated neurological disease, an excitotoxin delivered to the central nervous system (CNS), could trigger neuronal death not only in the somatodendritic region, but also in the axonal region, via oligodendrocyte N-methyl-D-aspartate (NMDA) receptors. The retina and optic nerve, as approachable regions of the brain, provide a unique anatomical substrate to investigate the “downstream” effect of isolated excitotoxic perikaryal injury on central nervous system (CNS) axons, potentially providing information about the pathogenesis of the axonopathy in clinical neurological disorders. Herein, we provide ultrastructural information about the retinal ganglion cell (RGC) somata and their axons, both unmyelinated and myelinated, after NMDA-induced retinal injury. Male Sprague-Dawley rats were killed at 0 h, 24 h, 72 h and 7 days after injecting 20 nM NMDA into the vitreous chamber of the left eye (n = 8 in each group). Saline-injected right eyes served as controls. After perfusion fixation, dissection, resin-embedding and staining, ultrathin sections of eyes and proximal (intraorbital) and distal (intracranial) optic nerve segments were evaluated by transmission electron tomography (TEM). RESULTS: TEM demonstrated features of necrosis in RGCs: mitochondrial and endoplasmic reticulum swelling...

Molecular mechanisms in inherited retinal degeneration: Exploring three routes towards understanding Retinitis pigmentosa; Molekulare Mechanismen bei erblicher Retina-Degeneration: Erkundung dreier Wege zum Verständnis von Retinitis pigmentosa

Farinelli, Pietro
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
EN
Relevância na Pesquisa
36.68%
Retinitis pigmentosa (RP) groups a family of hereditary neurodegenerative diseases of the retina characterized by progressive loss of photoreceptors and for which treatment is still lacking. The aim of this thesis was to find and investigate novel markers of retinal degeneration in order to aid the understanding of the disease and the development of neuroprotective treatments. In this work four different rodent models for RP were used (rd1 and rd2 mice; S334ter and P23H rats), allowing the identification of several new players in inherited retinal degeneration. In order to do that, a wide range of techniques, including biochemistry and molecular biology, as well as microscopy and organotypic culturing methodologies were used. The main results achieved in this dissertation may be summarised as follows: 1. Increased expression of alfa-Klotho was seen in dying photoreceptors of all four models of RP. Addition of alfa-Klotho ectodomain on organotypic retinal cultures impaired retinal organization. In addition, fibroblast growth factor 15 (FGF15) was down-regulated in rd1 and rd2 mice, indicating an imbalance of the alfa-Klotho/FGF15 axis. 2. Histone deacetylases (HDAC) class I and II were over-activated and played a critical role in the cell death pathways of the rd1 mouse retina. Blockade of class I and II of this family of enzymes with trichostatin A (TSA) protected photoreceptors in vitro. 3. Increased methylation of DNA occurred in dying photoreceptors of all four rodent RP models. Moreover...

The Role of PARP1 in cGMP Mediated Photoreceptor Degeneration; Die Rolle von PARP1 in cGMP induzierter Photorezeptordegeneration

Sahaboglu Tekgöz, Ayse
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
EN
Relevância na Pesquisa
36.74%
Retinitis Pigmentosa (RP) is an inherited eye disease which causes progressive photoreceptor degeneration and consequently blindness in humans. So far, there has been no found cure or reliable treatment for RP. The retinal degeneration 1 (rd1)mouse model is a well-studied model of human autosomal recessive RP. In 2007, it was found that over-activation of poly(ADP-ribose) polymerases (PARP) contributed to photoreceptor degeneration in the rd1 mouse. However, it was still unclear which PARP family member exactly was involved in photoreceptor degeneration. Therefore, the aim of this thesis was to investigate the role of PARP1, the most prominently expressed and extensively studied member of the PARP family, in photoreceptor degeneration in the rd1 retina. Electroretinography, optic coherence tomography (OCT), scanning laser ophthalmoscopy (SLO), and histology identified no significant differences between PARP1 knock-out (KO) and wild-type (wt) animals in terms of retinal function, thickness, and structure. In addition to PARP, histone deacetylase (HDAC) activity was shown to be involved in rd1 photoreceptor degeneration. Double-label immunohistochemistry showed poly(ADP-ribose) (PAR) accumulation - i.e. the product of PARP activity - in photoreceptor nuclei that were devoid of acetylated proteins...

Mechanisms of cone photoreceptor cell death in models for inherited retinal degeneration; Zelltodmechanismen der Zapfenphotorezeptoren in Modellen mit erblicher retinaler Degeneration

Mencl, Stine
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
EN
Relevância na Pesquisa
36.78%
In hereditary eye diseases of the Retinitis pigmentosa (RP) type, rod photoreceptors degenerate in a mutation-dependent fashion, followed by mutation independent cone cell death. Until today, no adequate treatment is available, but efforts are made to gain more knowledge about the mechanism of photoreceptor degeneration. To do so various animal models are available, showing mutations and symptoms comparable to human patients. In this study three models for RP (rd1 mouse, S334ter rat, and P23H rat) and a cone degeneration model, the cpfl1 mouse were investigated, asking whether a CRE-mediated transcription repressor, the inducible cAMP early repressor (ICER) was expressed. Since ICER is known to be involved in cell death in many neuronal and non-neural cells (Borlikova and Endo 2009), it may also have a detrimental effect on neuronal retinal cells. With immunostaining, ICER expression was observed in GCL, INL and in cone photoreceptors of all mutants and corresponding wt retinas. However, during cone degeneration or cone cell stress ICER expression was significantly upregulated in all mutant retinas. This finding suggests a role of ICER in cone degeneration and needs to be further investigated. Human vision is strongly depending on cone photoreceptors...

Ultrastructural relationship of quadriceps muscle degeneration with a distant peroneal nerve conduction in human myotonia dystrophica

Sinha, Akhouri A.; Olson, Norman D.; Nuttall, Frank Q.
Fonte: Murcia : F. Hernández Publicador: Murcia : F. Hernández
Tipo: Artigo de Revista Científica Formato: application/pdf
ENG
Relevância na Pesquisa
36.65%
The association of motor nerve conduction velocity (MNCV) to (1) duration of symptoms, (2) deep tendon reflex responses, (3) clinical muscle atrophy, and (4) ultrastructure of quadriceps muscle was studied in 18 patients with myotonia dystrophica of Steinert and nine normal controls. These patients had neither diabetes mellitus nor any other type of muscle dystrophy. Ultrastructural features of muscle fibers and intercellular spaces between atrophic fibers provided a basis for identifying degenerative changes and evaluating them semi-quantitatively. Our study indicates presence of an association between the pattern of muscle degeneration and both MNCV (correlation coefficients, y=+0.60) and duration of symptoms (y=-0.62), but not between MNCV and duration of symptoms (y=+0.28). Further analysis of the association between the degeneration of quadriceps and the MNCV of a distant peroneal nerve (which does not innenate quadriceps) suggested that the systemic nerve degeneration occurred in some groups of myotonia patients. Our study indicates that while in some patients the muscle degeneration may have been associated with the impairment of neurogenic elements, in others it occured in the absence of any MNCV abnormality. Our findings favor the role of both neuropathic and myopathic factors in the muscle degeneration seen in myotonia dystrophica.

Influencia do acido ascorbico no processo de degeneração muscular em camundongos distroficos; Influence of the ascorbic acid in the muscular degeneration process in dystrophic mice

Erika Tonon
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 26/02/2009 PT
Relevância na Pesquisa
36.65%
A peroxidação lípidica causada pelo aumento de espécies reativas de oxigênio (EROs) no período que antecede o início da degeneração muscular no camundongo mdx, sugere que o estresse oxidativo pode ser um dos mecanismos primários da degeneração muscular distrófica, ao invés de ser um efeito secundário deste processo. No presente trabalho verificamos se o tratamento com ácido ascórbico antes que se iniciem os ciclos de degeneração/regeneração diminui a degeneração muscular em camundongos mdx. Camundongos mdx com 14 dias de vida pós-natal receberam por gavagem doses diárias de 0,1mg/kg de Ácido Ascórbico diluído em água por 7 (grupo mdx T7) e 14 dias (grupo mdx T14) e/ou dose de 200mg/kg por 14 dias (grupo mdx T14AA). Animais mdx controle receberam solução salina. Após este período, os músculos tibial anterior (TA), esternomastóide (STN) e diafragma (DIA) foram retirados. Na análise histológica, o ácido ascórbico diminuiu a degeneração muscular nos músculos TA do grupo mdx T7 e no DIA do grupo mdx T14AA (P<0,05, Student's t Test) quando comparados ao controle. Não houve diferença significativa nos níveis séricos de creatina quinase entre os grupos analisados (P>0,05, Student's t Test). Aumento significativo no conteúdo de TNF-"...

Watery and dark axons in Wallerian degeneration of the opossum's optic nerve: different patterns of cytoskeletal breakdown?

NARCISO,MARCELO S.; HOKOÇ,JAN NORA; MARTINEZ,ANA M. B.
Fonte: Academia Brasileira de Ciências Publicador: Academia Brasileira de Ciências
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2001 EN
Relevância na Pesquisa
36.7%
In this paper we report a qualitative morphological analysis of Wallerian degeneration in a marsupial. Right optic nerves of opossums Didelphis marsupialis were crushed with a fine forceps and after 24, 48, 72, 96 and 168 hours the animals were anaesthetized and perfused with fixative. The optic nerves were immersed in fixative and processed for routine transmission electron microscopy. Among the early alterations typical of axonal degeneration, we observed nerve fibers with focal degeneration of the axoplasmic cytoskeleton, watery degeneration and dark degeneration, the latter being prevalent at 168 hours after crush. Our results point to a gradual disintegration of the axoplasmic cytoskeleton, opposed to the previous view of an "all-or-nothing'' process (Griffin et al 1995). We also report that, due to an unknown mechanism, fibers show either a dark or watery pattern of axonal degeneration, as observed in axon profiles. We also observed fibers undergoing early myelin breakdown in the absence of axonal alterations.

Risk factors of age-related macular degeneration in Argentina

Nano,María Eugenia; Lansingh,Van Charles; Pighin,María Soledad; Zarate,Natalia; Nano,Hugo; Carter,Marissa Janine; Furtado,João Marcello; Nano,Clelia Crespo; Vernengo,Luciana Fiocca; Luna,José Domingo; Eckert,Kristen Allison
Fonte: Conselho Brasileiro de Oftalmologia Publicador: Conselho Brasileiro de Oftalmologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2013 EN
Relevância na Pesquisa
36.76%
PURPOSES: To assess the risk factors of age-related macular degeneration in Argentina using a case-control study. METHODS: Surveys were used for subjects' antioxidant intake, age/gender, race, body mass index, hypertension, diabetes (and type of treatment), smoking, sunlight exposure, red meat consumption, fish consumption, presence of age-related macular degeneration and family history of age-related macular degeneration. Main effects models for logistic regression and ordinal logistic regression were used to analyze the results. RESULTS: There were 175 cases and 175 controls with a mean age of 75.4 years and 75.5 years, respectively, of whom 236 (67.4%) were female. Of the cases with age-related macular degeneration, 159 (45.4%) had age-related macular degeneration in their left eyes, 154 (44.0%) in their right eyes, and 138 (39.4%) in both eyes. Of the cases with age-related macular degeneration in their left eyes, 47.8% had the dry type, 40.3% had the wet type, and the type was unknown for 11.9%. The comparable figures for right eyes were: 51.9%, 34.4%, and 13.7%, respectively. The main effects model was dominated by higher sunlight exposure (OR [odds ratio]: 3.3) and a family history of age-related macular degeneration (OR: 4.3). Other factors included hypertension (OR: 2.1)...

Axonal Degeneration Is Mediated by the Mitochondrial Permeability Transition Pore

Yoo, Soonmoon; Zamorano, Sebastián; Twiss, Jeffery L.; Hetz, Claudio; Alvarez, Jaime; Jara, Juan S.; Court, Felipe A.; Martínez, Nicolas W.; Barrientos, Sebastián A.
Fonte: SOC NEUROSCIENCE Publicador: SOC NEUROSCIENCE
Tipo: Artículo de revista
EN
Relevância na Pesquisa
36.68%
Axonal degeneration is an active process that has been associated with neurodegenerative conditions triggered by mechanical, metabolic, infectious, toxic, hereditary and inflammatory stimuli. This degenerative process can cause permanent loss of function, so it represents a focus for neuroprotective strategies. Several signaling pathways are implicated in axonal degeneration, but identification of an integrative mechanism for this self-destructive process has remained elusive. Here, we show that rapid axonal degeneration triggered by distinct mechanical and toxic insults is dependent on the activation of the mitochondrial permeability transition pore (mPTP). Both pharmacological and genetic targeting of cyclophilin D, a functional component of the mPTP, protects severed axons and vincristine-treated neurons from axonal degeneration in ex vivo and in vitro mouse and rat model systems. These effects were observed in axons from both the peripheral and central nervous system. Our results suggest that the mPTPis a key effector of axonal degeneration, upon which several independent signaling pathways converge. Since axonal and synapse degeneration are increasingly considered early pathological events in neurodegeneration, our work identifies a potential target for therapeutic intervention in a wide variety of conditions that lead to loss of axons and subsequent functional impairment.; Fondo Nacional de Desarrollo Cientifico y Tecnologico (FONDECYT) 1070377 1070444 Millennium Nucleus P-07-011-F P-07-048-F National Institutes of Health R01-NS049041 R01-NS041596 Fondo de Financiamiento de Centros de Excelencia en Investigacion (FONDAP) 15010006 Muscular Dystrophy Association CHDI Foundation Inc. M. J. Fox Foundation for Parkinson Research International Centre for Genetic Engineering and Biotechnology

Acquired chronic hepatocerebral degeneration due to cirrhosis from non-alcoholic steatohepatitis

Burgos,A.; Bermejo,P. E.; Calleja,J. L.; Vaquero,A.; Abreu,L. E.
Fonte: Revista Española de Enfermedades Digestivas Publicador: Revista Española de Enfermedades Digestivas
Tipo: info:eu-repo/semantics/article; journal article; info:eu-repo/semantics/publishedVersion Formato: text/html; application/pdf
Publicado em 01/11/2009 ENG
Relevância na Pesquisa
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Introduction and objective: acquired chronic hepatocerebral degeneration, acquired hepatolenticular degeneration or pseudo-Wilson is an infrequent disorder with a hepatic origin. Cases in the literature are scarce and it is frequently confused with hepatic encephalopathy and Wilson's disease. The aim of this essay is to report a patient suffering from this disorder due to cirrhosis from non-alcoholic steatohepatitis. Case report: we present a 54-year-old man diagnosed from cirrhosis grade B9 of the Child Pugh classification. He progressively developed a picture with bradylalia, mild postural and action tremor and spatial and temporal disorientation. Further studies demonstrated an increase of the values of hepatic transaminases and a hiperintensity in the basal nuclei in the cerebral magnetic resonance imaging. Clinical and radiological data established the diagnosis of hepatocerebral degeneration. Conclusions: acquired chronic hepatocerebral degeneration is a disorder rarely reported in the literature that it is usually confused with other diseases. We alert about the need of having this diagnosis into account with patients developing neurological symptoms after hepatic disease.