19 resultados para Retinal diseases

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)


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Transition to diets that are high in saturated fat and sugar has caused a global public health concern as the pattern of food consumption is a mayor modifiable risk factor for chronic non-communicable diseases Although agri food systems are intimately associated with this transition, agriculture and health sectors are largely disconnected in their priorities policy, and analysis with neither side considering the complex inter relation between agri trade patterns of food consumption health, and development We show the importance of connection of these perspectives through estimation of the effect of adopting a healthy diet on population health, agricultural production trade the economy and livelihoods, with a computable general equilibrium approach On the basis of case studies from the UK and Brazil we suggest that benefits of a healthy diet policy will vary substantially between different populations, not only because of population dietary intake but also because of agricultural production trade and other economic factors

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Medicines and other Resources Utilized in Order to Cope Infants Diseases in the Family Daily Life: a qualitative study. The study proposes to investigate the use of medications, medicinal plants and other therapeutic resources to cope infants diseases in the domestic realm in an urban area. The ethnographic research method was utilized as referential, guiding the study for 10 months with 20 fortnight meetings in the domicile of 15 families. The study followed up 180 episodes of disease, 74,5% were treated, in a first instance, at home, resulting in the use of 212 therapeutic resources. The main type of therapeutic resource utilized was industrialized medicines, differing considerably from its clinic recommendations. The realm of the health services was more mobilized as a second treatment option. In the community realm, treatment of diseases known from the popular culture was performed via blessings and prayers. The families use medicines as cultural practices and the acceptance of some type of treatment depends on the expectations and experiences of the family.

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The avian circadian system is composed of the retina, the mammalian homolog region of the suprachiasmatic nucleus (SNC), and the pineal gland. The retina, itself, displays many rhythmic physiological events, such as movements of photoreceptor cells, opsin expression, retinal reisomerization, and melatonin and dopamine production and secretion. Altogether, these rhythmic events are coordinated to predict environmental changes in light conditions during the day, optimizing retina function. The authors investigated the expression pattern of the melanopsin genes Opn4x and Opn4m, the clock genes Clock and Per2, and the genes for the key enzymes N-Acetyltransferase and Tyrosine Hidroxylase in chicken embryo dispersed retinal cells. Primary cultures of chicken retina from 8-day-old embryos were kept in constant dark (DD), in 12-h light/12-h dark (12L:12D), in 12L:12D followed by DD, or in DD in the absence or presence of 100 mu M glutamate for 12 h. Total RNA was extracted throughout a 24-h span, every 3 h starting at zeitgeber time 0 (ZT0) of the 6th day, and submitted to reverse transcriptase-polymerase chain reaction (RT-PCR) followed by quantitative PCR (qPCR) for mRNA quantification. The data showed no rhythmic pattern of transcription for any gene in cells kept in DD. However under a light-dark cycle, Clock, Per2, Opn4m, N-Acetyltransferase, and Tyrosine Hydroxylase exhibited rhythmic patterns of transcription. In DD, 100 mu M glutamate was able to induce rhythmic expression of Clock, strongly inhibited the expression of Tyrosine Hydroxylase, and, only at some ZTs, of Opn4x and Opn4m. The neurotransmitter had no effect on Per2 and N-Acetyltransferase transcription. The authors confirmed the expression of the protein OPN4x by immunocytochemistry. These results suggest that chicken embryonic retinal cells contain a functional circadian clock, whose synchronization requires light-dark cycle or glutamate stimuli. (Author correspondence: amdlcast@ib.usp.br).

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We have previously shown that melatonin influences the development of alpha 8 nicotinic acetylcholine receptor (nAChR) by measurement of the acetylcholine-induced increase in the extracellular acidification rate (ECAR) in chick retinal cell cultures. Cellular differentiation that takes place between DIV (days in vitro) 4 and DIV 5 yields cells expressing alpha 8 nAChR and results in a significant increase in the ECAR acetylcholine-induced. Blocking melatonin receptors with luzindole for 48 h suppresses the development of functional alpha 8 nAChR. Here we investigated the time window for the effect of melatonin on retinal cell development in culture, and whether this effect was dependent on an increase in the expression of alpha 8 nAChR. First, we confirmed that luzindole was inhibiting the effects of endogenous melatonin, since it increases 2-[(125)I] iodomelatonin (23 pM) binding sites density in a time-dependent manner. Then we observed that acute (15, 60 min, or 12 h) luzindole treatment did not impair acetylcholine-induced increase in the ECAR mediated by activation of alpha 8 nAChR at DIV 5, while chronic treatment (from DIV 3 or DIV 4 till DIV 5, or DIV 3.5 till DIV 4.5) led to a time-dependent reduction of the increase in the acetylcholine-induced ECAR. The binding parameters for [(125)I]-alpha-bungarotoxin (10 nM) sites in membrane were unaffected by melatonin suppression that started at DIV 3. Thus, melatonin surges in the time window that occurs at the final stages of chick retinal cell differentiation in culture is essential for development of the cells expressing alpha 8 nAChR subtype in full functional form. (C) 2010 ISDN. Published by Elsevier Ltd. All rights reserved.

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The neuromuscular disorders are a heterogeneous group of genetic diseases, caused by mutations in genes coding sarcolemmal, sarcomeric, and citosolic muscle proteins. Deficiencies or loss of function of these proteins leads to variable degree of progressive loss of motor ability. Several animal models, manifesting phenotypes observed in neuromuscular diseases, have been identified in nature or generated in laboratory. These models generally present physiological alterations observed in human patients and can be used as important tools for genetic, clinic, and histopathological studies. The mdx mouse is the most widely used animal model for Duchenne muscular dystrophy (DMD). Although it is a good genetic and biochemical model, presenting total deficiency of the protein dystrophin in the muscle, this mouse is not useful for clinical trials because of its very mild phenotype. The canine golden retriever MD model represents a more clinically similar model of DMD due to its larger size and significant muscle weakness. Autosomal recessive limb-girdle MD forms models include the SJL/J mice, which develop a spontaneous myopathy resulting from a mutation in the Dysferlin gene, being a model for LGMD2B. For the human sarcoglycanopahties (SG), the BIO14.6 hamster is the spontaneous animal model for delta-SG deficiency, whereas some canine models with deficiency of SG proteins have also been identified. More recently, using the homologous recombination technique in embryonic stem cell, several mouse models have been developed with null mutations in each one of the four SG genes. All sarcoglycan-null animals display a progressive muscular dystrophy of variable severity and share the property of a significant secondary reduction in the expression of the other members of the sarcoglycan subcomplex and other components of the Dystrophin-glycoprotein complex. Mouse models for congenital MD include the dy/dy (dystrophia-muscularis) mouse and the allelic mutant dy(2J)/dy(2J) mouse, both presenting significant reduction of alpha 2-laminin in the muscle and a severe phenotype. The myodystrophy mouse (Large(myd)) harbors a mutation in the glycosyltransferase Large, which leads to altered glycosylation of alpha-DG, and also a severe phenotype. Other informative models for muscle proteins include the knockout mouse for myostatin, which demonstrated that this protein is a negative regulator of muscle growth. Additionally, the stress syndrome in pigs, caused by mutations in the porcine RYR1 gene, helped to localize the gene causing malignant hypertermia and Central Core myopathy in humans. The study of animal models for genetic diseases, in spite of the existence of differences in some phenotypes, can provide important clues to the understanding of the pathogenesis of these disorders and are also very valuable for testing strategies for therapeutic approaches.

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Circadian rhythms generated by the suprachiasmatic nucleus (SCN) are modulated by photic and non-photic stimuli. In rodents, direct photic stimuli reach the SCN mainly through the retinohypothalamic tract (RHT), whereas indirect photic stimuli are mainly conveyed by the geniculohypothalamic tract (GHT). In rodents, retinal cells form a pathway that reaches the intergeniculate leaflet (IGL) where they establish synapses with neurons that express neuropeptide Y (NPY), hence forming the GHT projecting to the SCN. In contrast to the RHT, which has been well described in primates, data regarding the presence or absence of the IGL and GHT in primates are contradictory. Some studies have suggested that an area of the pregeniculate nucleus (PGN) of primates might be homologous to the IGL of rodents, but additional anatomical and functional studies on primate species are necessary to confirm this hypothesis. Therefore, this study investigated the main histochemical characteristics of the PGN and the possible existence of the GHT in the SCN of the primate Cebus, comparing the distribution of NPY immunoreactivity, serotonin (5-HT) immunoreactivity and retinal terminal fibers in these two structures. The results show that a collection of cell bodies containing NPY and serotonergic immunoreactivity and retinal innervations are present within a zone that might be homologous to the IGL of rodents. The SCN also receives dense retinal innervations and we observed an atypical distribution of NPY- and 5-HT-immunoreactive fibers without regionalization in the ventral part of the nucleus as described for other species. These data may reflect morphological differences in the structures involved in the regulation of circadian rhythms among species and support the hypothesis that the GHT is present in some higher primates (diurnal animals). (C) 2009 Elsevier B.V. All rights reserved.

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We investigated the possible participation of TRPV1 channels in retinal apoptosis and overall development. Retinas from newborn, male albino rats were treated in vitro with capsazepine, a TRPV1 antagonist. The expression of cell cycle markers was not changed after TRPV1 blockade, whereas capsazepine reduced the number of apoptotic cells throughout the retina,increased ERK1/2 and p38 phosphorylation and slightly reduced JNK phosphorylation. The expression of BAD, Bcl-2, as well as integral and cleaved capsase-3 were similar in all experimental conditions. Newborn rats were kept for 2 months after receiving high doses of capsazepine. In their retinas, calbindin and parvalbumin protein levels were upregulated, but only the number of amacrine-like, parvalbumin-positive cells was increased. The numbers of calretinin, calbindin, ChAT, vimentin, PKC-alpha and GABA-positive cells were similar in both conditions. Protein expression of synapsin Ib was also increased in the retinas of capsazepine-treated rats. Calretinin, vimentin, GFAP, synapsin Ia, synaptophysin and light neurofilament protein levels were not changed when compared to control values. Our results indicate that TRPV1 channels play a role in the control of the early apoptosis that occur during retinal development, which might be dependent on MAPK signaling. Moreover, it seems that TRPV1 function might be important for neuronal and synaptic maturation in the retina. (C) 2011 ISDN. Published by Elsevier Ltd. All rights reserved.

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Traditional retinal projections target three functionally complementary systems it) the brain of mammals: the primary visual system, the visuomotor integration systems and the circadian timing system. In recent years, studies in several animals have been conducted to investigate the retinal projections to these three systems, despite some evidence of additional targets. The aim of this study was to disclose a previously unknown connection between the retina and the parabrachial complex of the common marmoset, by means of the intraocular injection of cholera toxin Subunit b. A few labeled retinal fibers/terminals that are detected in the medial parabrachial portion of the marmoset brain show clear varicosities, Suggesting terminal fields. Although the possible role of these projections remains unknown, they may provide a modulation of the cholinergic parabrachial neurons which project to the thalamic dorsal lateral geniculate nucleus. (c) 2008 Elsevier Ireland Ltd. All rights reserved.

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The endocannabinoid system has been implicated in several neurobiological processes, including neurodegeneration and neuro protection. The aim of this study was to evaluate the effects of unilateral retinal ablation on the expression of the cannabinoid receptor subtype 1 (CB1) at both protein and mRNA levels in the optic tectum of the adult chick brain. After different survival times postlesion (2-30 days), the chick brains were subjected to immunohistochemical, immunoblotting, and real-time PCR procedures to evaluate CB1 expression. TUNEL and Fluoro-Jade B were used to verify the possible occurrence of cell death, and immunostaining for the microtubule-associated protein MAP-2 was performed to verify possible dendritic remodeling after lesions. No cell death could be observed in the deafferented tectum, at least up to 30 days postlesion, although Fluoro-Jade B could reveal degenerating axons and terminals. Retinal ablation seems to generate an increase of CB1 protein in the optic tectum and other retinorecipient visual areas, which paralleled an increase in MAP-2 staining. On the other hand, CB, mRNA levels were not changed after retinal ablation. Our results reveal that CB, expression in visual structures of the adult chick brain may be negatively regulated by the retinal innervation. The increase of CB1 receptor expression observed after retinal removal indicates that these receptors are not presynaptic in retinal axons projecting to the tectum and suggests a role of the cannabinoid system in plasticity processes ensuing after lesions. (c) 2008 Wiley-Liss, Inc.

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Connexin (Cx) channels and hemichannels are involved in essential processes during nervous system development such as apoptosis, propagation of spontaneous activity and interkinetic nuclear movement. In the first part of this study, we extensively characterized Cx gene and protein expression during retinal histogenesis. We observed distinct spatio-temporal patterns among Studied Cx and an overriding, ubiquitous presence of Cx45 in progenitor cells. The role of Cx-mediated communication was assessed by using broad-spectrum (carbenoxotone, CBX) and Cx36/Cx50 channel-specific (quinine) blockers. In vivo application of CBX, but not quinine, caused remarkable reduction in retinal thickness, suggesting changes in cell proliferation/apoptosis ratio. Indeed, we observed a decreased number of mitotic cells in CBX-injected retinas, with no significant changes in the expression of PCNA, a marker for cells in proliferative state. Taken together, Our results pointed a pivotal role of Cx45 in the developing retina. Moreover, this study revealed that Cx-mediated Communication is essential in retinal histogenesis, particularly in the control of cell proliferation. (C) 2009 ISDN. Published by Elsevier Ltd. All rights reserved.

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Early diagnosis and appropriate therapy are essential for the best prognosis and quality of life in patients with primary immunodeficiency diseases (PIDDs). Experts from several Latin American countries have been meeting on a regular basis as part of an ongoing effort to improve the diagnosis and treatment of PIDD in this region. Three programmes are in development that will expand education and training and improve access to testing facilities throughout Latin America. These programmes are: an educational outreach programme (The L-Project); an immunology fellowship programme; and the establishment of a laboratory network to expand access to testing facilities. This report provides the status of these programmes based on the most recent discussions and describes the next steps toward full implementation of these programmes. (C) 2010 SEICAP. Published by Elsevier Espana, S.L. All rights reserved.

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Experts from six Latin American countries met to discuss critical issues and needs in the diagnosis and management of primary immunodeficiency diseases (PIDD). The diagnosis of PIDD is generally made following referral to an immunology centre located in a major city, but many paediatricians and general practitioners are not sufficiently trained to suspect PIDD in the first place. Access to laboratory testing is generally limited, and only some screening tests are typically covered by government health programmes. Specialised diagnostic tests are generally not reimbursed. Access to treatment varies by country reflecting differences in healthcare systems and reimbursement policies. An online PIDD Registry Programme for Latin America has been available since 2009, which will provide information about PIDD epidemiology in the region. Additional collaboration across countries appears feasible in at least two areas: a laboratory network to facilitate the diagnosis of PIDD, and educational programmes to improve PIDD awareness. In total, these collaborations should make it possible to advance the diagnosis and management of PIDD in Latin America. (C) 2010 SEICAP. Published by Elsevier Espana, S.L. All rights reserved.

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Background Chronic myeloproliferative disorders (MPDs) are clonal haematopoietic stem cell malignancies characterised by an accumulation of mature myeloid cells in bone marrow and peripheral blood. Deregulation of the apoptotic machinery may be associated with MPD physiopathology. Aims To evaluate expression of death receptors` family members, mononuclear cell apoptosis resistance, and JAK2 allele burden. Subjects and Methods Bone marrow haematopoietic progenitor CD34 cells were separated using the Ficoll-hypaque protocol followed by the Miltenyi CD34 isolation kit, and peripheral blood leukocytes were separated by the Haes-Steril method. Total RNA was extracted by the Trizol method, the High Capacity Kit was used to synthesise cDNA, and real-time PCR was performed using SybrGreen in ABIPrism 7500 equipment. The results of gene expression quantification are given as 2(-Delta Delta Ct). The JAK2 V617F mutation was detected by real-time allelic discrimination PCR assay. Peripheral blood mononuclear cells (PBMCs) were isolated by the Ficoll-hypaque protocol and cultured in the presence of apoptosis inducers. Results In CD34 cells, there was mRNA overexpression for fas, faim and c-flip in polycythaemia vera (PV), essential thrombocythaemia (ET) and primary myelofibrosis (PMF), as well as fasl in PMF, and dr4 levels were increased in ET. In leukocytes, fas, c-flip and trail levels were increased in PV, and dr5 expression was decreased in ET. There was an association between dr5 and fasl expression and JAK2V617F mutation. PBMCs from patients with PV, ET or PMF showed resistance to apoptosis inducers. Conclusions The results indicate deregulation of apoptosis gene expression, which may be associated with MPD pathogenesis leading to accumulation of myeloid cells in MPDs.

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Investigating the proteolytic activity of the recombinant Mycobacterium leprae Heat Shock Protein of 65 kDa (rHsp65), chaperonin 2 (cpn2), we observed that it displays high instability. The fragmentation process starts at the C-terminus followed by progressive degradation of the N-terminus, which leads to a stable fragment comprising the middle region of the molecule. Urea was able to prevent autolysis, probably due to its denaturing action, while EDTA increased degradation levels indicating the need for metal ions. Peptides originated from autolysis were purified and analyzed by mass spectrometry, generating a continuous map. Since the bacteria and mammalian Hsp60 are known to be targets of the immune response and have been implicated in autoimmune diseases and chronic inflammation, the in vivo effect of rHsp65 peptides was evaluated in the spontaneous Systemic Lupus Erythematosus (SLE) model developed by the (NZB/NZW)F(1) mouse hybrids, and their individual anti-rHsp65 IgG2a/IgG1 antibody titer ratio was determined. The results showed orientation toward a T(H)1 responsiveness, and the treatment with the rHsp65 peptides diminished the environmental variance of the survival time of treated animals. These results outline the fact that environmental factors may also act through the modified stability expression of Heat Shock Proteins intervening during autoimmune processes. (C) 2011 Elsevier Ltd. All rights reserved.

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Objective. To investigate the short-term effects of exposure to particulate matter from biomass burning in the Amazon on the daily demand for outpatient care due to respiratory diseases in children and the elderly. Methods. Epidemiologic study with ecologic time series design. Daily consultation records were obtained from the 14 primary health care clinics in the municipality of Alta Floresta, state of Mato Grosso, in the southern region of the Brazilian Amazon, between January 2004 and December 2005. Information on the daily levels of fine particulate matter was made available by the Brazilian National Institute for Spatial Research. To control for confounding factors ( situations in which a non-causal association between exposure and disease is observed due to a third variable), variables related to time trends, seasonality, temperature, relative humidity, rainfall, and calendar effects ( such as occurrence of holidays and weekends) were included in the model. Poisson regression with generalized additive models was used. Results. A 10 mu g/m(3) increase in the level of exposure to particulate matter was associated with increases of 2.9% and 2.6% in outpatient consultations due to respiratory diseases in children on the 6th and 7th days following exposure. Significant associations were not observed for elderly individuals. Conclusions. The results suggest that the levels of particulate matter from biomass burning in the Amazon are associated with adverse effects on the respiratory health of children.