Eletroretinograma de padrão reverso no diagnóstico e acompanhamento das afecções da via óptica anterior

The pattern electroretinogram is an electrophysiological test that assesses the function of inner retinal layers, particularly the ganglion cells layer of retina, using a reversing checkerboard or grating pattern that produces no change in average luminance over time. The normal pattern electroretinogram is composed of a proeminent positive component (P50) and a large later negative component (N95). Since structural damage that compromises the retinal ganglion cell layer can lead to pattern electroretinogram changes, particularly in the N95 amplitude, the test can be useful in the treatment of a number of anterior visual pathway diseases. In this article, we review the methods for recording pattern electroretinogram and its usefulness in the diagnosis and management of diseases including inflammatory, hereditary, ischemic and compressive lesions of the anterior visual pathway.O eletroretinograma de padrão reverso é um teste eletrofisiológico que avalia a função das camadas internas da retina, especialmente a camada de células ganglionares, através de um estímulo em xadrez ou em barras que não apresenta variação na luminância do estímulo. É composto de um componente positivo (P50) e um componente negativo (N95) tardio. Uma vez que lesões estruturais às células ganglionares da reitna podem levar a alterações no eletroretinograma de padrão reverso, especialmente na amplitude da onda N95, o teste pode ser útil no tratamento de várias doenças da via óptica anterior. Neste artigo revisamos os métodos de obtenção do eletroretinograma de padrão reverso e a sua utilidade no diagnóstico e acompanhamento de doenças incluindo lesões inflamatórias, hereditárias, isquemicas e compressivas na via óptica anterior

Optic nerve meningioma mimicking progression of glaucomatous axonal damage: a case report

O objetivo é relatar um caso de meningioma da bainha do nervo óptico localizado na região do canal óptico simulando progressão de dano axonal glaucomatoso. Paciente de 60 anos em tratamento para glaucoma primário de ângulo aberto apresentou perda progressiva do campo visual e aumento da escavação do disco óptico à esquerda. Devido à rapidez e à assimetria da progressão do dano axonal, por causa da redução da acuidade visual e do aparente bom controle pressórico uma lesão compressiva do nervo óptico foi suspeitada. A tomografia computadorizada de órbitas foi normal, entretanto a imagem por ressonância magnética evidenciou um meningioma da bainha do nervo óptico na região do canal óptico. Afecções compressivas da via óptica anterior são causas incomuns de escavação do disco óptico, entretanto podem simular uma neuropatia glaucomatosa e devem ser lembradas nos pacientes com suspeita de glaucoma de baixa pressão intra-ocular ou em tratamento para glaucoma que apresentem evolução atípica da perda visual.To report a case of an optic nerve sheath meningioma located at the optic canal area mimicking the progression of a glaucomatous axonal damage. A 60-year-old female patient developed progressive visual field loss and enlargement of the optic disc cup in the left eye while in treatment for primary open-angle glaucoma. Because of the rapid progression of axonal loss, the asymmetry of the visual field defect and the fact that intraocular pressure had been under control, a compressive optic neuropathy was suspected. A computerized tomography scan of the orbit was normal but a high-resolution magnetic resonance imaging demonstrated an optic nerve sheath meningioma located at the optic canal area. Compressive lesions of the anterior visual pathways are uncommon causes of optic disc cupping but should be considered in patients suspected of or undergoing treatment for glaucoma that present with atypical progression of visual loss

Development of Flat Tube Heat Exchanger for Heat Pump Air Conditoner

We developed a new type of a heat pump outdoor unit using an aluminum flat tube heat exchanger in order to improve the energy saving capability of an air conditioner. There are several difficulties in keeping a desired drainage performance, frost formation performance, as well as even distribution of refrigerant, when applying the flat tube heat exchanger to heat pump outdoor units. In order to achieve the same drainage performance and the frost formation performance as those of conventional heat exchangers, we have adopted new plate fins with ellipse cutouts. Flat tubes were inserted in the ellipse cutouts, and the slit position on a plate fin was properly adjusted. In order to achieve the even distribution of refrigerant, an aluminum distributor and 3-way pipes were installed to the evaporator. In this report, first we describe features of the flat tube heat exchanger. Next, we present and explain experimental results of the air-side heat transfer coefficient and the air-side pressure drop on the condition of dry, wet, and frost state respectively. Moreover, we present experimental results of the total heat transfer performance, including the refrigerant performance, under the conditions of the condensation and the evaporation. Finally, we explain the heat transfer performance and the effect of the flat tube heat exchanger to a conventional one in the case that the developed heat exchanger was mounted in heat pump outdoor unit

Effect of Additive Elements Bi/Ni/Ge on Crack Initiation and Propagation for Low-Ag Solders

This study discusses an effect of additive elements on crack propagation behaviour for low-Ag contain Sn1.0Ag0.7Cu lead-free solders at high temperature. A cyclic push-pull loading tests for four kinds of Sn1.0Ag0.7Cu solders were conducted at 313 K with a single hole specimen. Stress amplitude of solders containing additive element Bi were bigger than that of Bi-free solders. Crack initiation cycle of solders containing Bi were earlier than that of Bi-free solders. Low-Ag solders containing Bi had shorter crack propagation cycles than that of Bi-free solders. These results indicate that the additive element Bi have the effects on the crack initiation and propagation cycles, that is, Bi accelerates the crack propagation rate. We also discuss the adaptation of J-integral range parameter to the crack propagation rate evaluation for solders. J-integral range parameter evaluates the crack propagation rate for low-Ag solders independent of the additive elements

Effect of additive elements Bi/Ni/Ge on crack initiation and propagation for low-Ag solders

This study discusses an effect of additive elements on crack propagation behaviour for low-Ag contain Sn1.0Ag0.7Cu lead-free solders at high temperature. A cyclic push-pull loading tests for four kinds of Sn1.0Ag0.7Cu solders were conducted at 313 K with a single hole specimen. Stress amplitude of solders containing additive element Bi were bigger than that of Bi-free solders. Crack initiation cycle of solders containing Bi were earlier than that of Bi-free solders. Low-Ag solders containing Bi had shorter crack propagation cycles than that of Bi-free solders. These results indicate that the additive element Bi have the effects on the crack initiation and propagation cycles, that is, Bi accelerates the crack propagation rate. We also discuss the adaptation of J-integral range parameter to the crack propagation rate evaluation for solders. J-integral range parameter evaluates the crack propagation rate for low-Ag solders independent of the additive element

Idiopathic thrombocytopenic purpura as initial manifestation of juvenile systemic lupus erythematosus

Patients with Idiopathic Thrombocytopenic Purpura (ITP) present a high trend to develop Systemic Lupus Erythematosus (SLE), especially those with chronic presentation. Some authors observed that female gender, older patients and familial history of autoimmune disease in patients with Idiopathic Thrombocytopenic Purpura are factors that lead to increased susceptibility for the development of Systemic Lupus Erythematosus. Based on these facts, we decided to study 5 children with chronic Idiopathic Thrombocytopenic Purpura and late Systemic Lupus Erythematosus. In this paper, we describe the clinical and laboratorial features of 5 female children with Idiopathic Thrombocytopenic Purpura that later developed Systemic Lupus Erythematosus. All patients were girls, 3 Caucasian, with Idiopathic Thrombocytopenic Purpura onset age ranged between 6 years and 3 months and 12 years and 1 month (mean - 9 years and 2 months). The age at Systemic Lupus Erythematosus diagnosis ranged between 8 years and 13 years and 8 months (mean - 10 years and 10 months). Though, the gap between Idiopathic Thrombocytopenic Purpura and Systemic Lupus Erythematosus diagnosis ranged between 11 months and 2 years and 9 months (mean - 1 year and 10 months). All patients presented chronic Idiopathic Thrombocytopenic Purpura (thrombocytopenia lasts longer than 6 months). The Systemic Lupus Erythematosus classification criteria were (in decreasing frequency): malar erythema and positivity of ANA in 5 patients; arthritis, hematological (thrombocytopenia) and immunological alterations (positivity of anti-DNA) in 4 patients; photosensitivity and positivity of anti-cardiolipin in 3 patients. Other manifestations included oral ulcers, renal involvement, leukopenia and auto-immune hemolytic anemia, serositis (pericarditis), neurological involvement and positivity of anti-Sm antibody. We would like to emphasize this form of presentation of Systemic Lupus Erythematosus, in which the Idiopathic Thrombocytopenic Purpura was the first manifestation and that the auto-antibody determination in every children with chronic form of this disease is very important.Os pacientes com púrpura trombocitopênica imunológica apresentam risco aumentado para desenvolver lúpus eritematoso sistêmico, principalmente quando a doença evolui de forma crônica. Alguns autores observaram que o sexo feminino, a idade mais avançada, a história familiar para lúpus eritematoso sistêmico podem ser fatores indicadores de maior risco para desenvolver lúpus em pacientes com púrpura trombocitopênica imunológica. Com base nestes fatos, resolvemos estudar cinco crianças nas quais a púrpura trombocitopênica imunológica foi o primeiro sintoma do lúpus eritematoso sistêmico. Neste artigo descrevemos as características clínicas e laboratoriais de cinco crianças com púrpura trombocitopênica imunológica que desenvolveram lúpus eritematoso sistêmico juvenil. Todas as crianças eram do sexo feminino - três caucasóides e duas pardas, com idade do início das manifestações de PTI variando entre 6 anos e 3 meses a 12 anos e 1 mês (média de 9 anos e 2 meses). A idade do diagnóstico de LESJ variou de 8 a 13 anos e 8 meses (média de 10 anos e 10 meses). Portanto, o intervalo de tempo entre o quadro de PTI e o diagnóstico de LESJ foi de 11 meses a 2 anos e 9meses (média de 1 ano e 10 meses). Todas as crianças apresentavam quadro de PTI crônica (plaquetopenia por mais de 6 meses). Os critérios de classificação para LESJ foram, em ordem de freqüência: rash malar e FAN positivo em 5 pacientes; artrite, alterações hematológica (plaquetopenia) e imunológica (anticorpo anti-DNA nativo) em 4; fotossensibilidade e ACL positivo em 3. Outras manifestações associadas foram úlceras orais, alterações renal e hematológica (leucopenia e AHAI com TCD positivo); serosite (pericardite), acometimento neurológico e alteração imunológica (anticorpo anti-Sm). Gostaríamos de alertar para esta forma de apresentação do lúpus eritematoso sistêmico em que o primeiro sintoma foi a púrpura trombocitopênica imunológica e salientar a importância da determinação de auto-anticorpos para lúpus eritematoso sistêmico nas crianças com a forma crônica desta patologia.UNIFESP-EPMUNIFESP, EPMSciEL