20 research outputs found

    Neuropatia óptica isquêmica anterior não arterítica bilateral após crise de fechamento angular num paciente com iridosquise: relato de caso

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    A 55-year-old woman was referred to our clinic because of a one-week history of visual loss and raised intraocular pressure in the left eye followed 4 days later by visual loss in the right eye. Slit-lamp examination showed bilateral conjunctival hyperemia, slight diffuse corneal edema, shallow anterior chamber and fixed and dilated pupil in both eyes. Splitting of the anterior layers of the iris with fibrillar degeneration extending for approximately one quadrant inferiorly was presented in each eye. Fundus examination showed opitc disc edema with no vascular tortuosity and no cup in both eyes. The condition was treated as bilateral acute angle-closure glaucoma in a patient with irisdoschisis. After medical treatment and improvement of visual acuity, perimetry revealed a significant visual field defect especially in left eye; this case represents a rare concurrence of acute angle-closure glaucoma and bilateral nonarteritic ischemic optic neuropathy. Although most cases of elevated intraocular pressure, including acute angle-closure glaucoma, do not result in optic disc edema and irreversible vision loss, variations in the vascular supply of the nerve optic head along with others ocular systemic risk factors, may predispose certain individuals to nonarteritic ischemic optic neuropathy during periods of elevated intraocular pressure.Paciente de 55 anos, sexo feminino, encaminhada para nosso serviço com história de perda de visão e aumento da pressão intraocular no olho esquerdo há uma semana seguida quatro dias após de perda visual no olho direito. À biomicroscopia hiperemia conjuntival bilateral, edema difuso da córnea, câmara anterior rasa e pupilas fixas e dilatadas em ambos os olhos. Separação do folheto anterior da íris no quadrante inferior estava presente em ambos os olhos. O exame do fundo do olho mostrava edema de disco sem tortuosidade vascular e sem escavação em ambos os olhos. O quadro clínico foi tratado como crise de fechamento angular bilateral num paciente com iridosquise. Após tratamento clínico e iridotomia bilateral com melhora da acuidade visual, a perimetria computadorizada revelou grave perda de campo visual, especialmente no olho esquerdo; este caso representa a rara ocorrência simultânea de crise de fechamento angular e neuropatia óptica isquêmica anterior não-arterítica bilateral. Embora a maioria dos casos com pressão intraocular elevada, incluindo crise de fechamento angular, não resulta em edema de disco e perda visual irreverssível, variações no suprimento vascular da cabeça do nervo óptico associados com outros fatores de risco sistêmicos, podem predispor certos indivíduos à neuropatia óptica isquêmica anterior durante períodos de elevação da pressão intraocular

    Synchrotron emission from the T Tauri binary system V773 Tau A

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    The pre-main sequence binary system V773 Tau A shows remarkable flaring activity around periastron passage. Here, we present the observation of such a flare at a wavelength of 3 mm (90 GHz) performed with the Plateau de Bure Interferometer. We examine different possible causes for the energy losses responsible for the e-folding time of 2.3 hours of that flare. We exclude synchrotron, collisional, and inverse Compton losses because they are not consistent with observational constraints, and we propose that the fading of the emission is due to the leakage of electrons themselves at each reflection between the two mirror points of the magnetic structure partially trapping them. The magnetic structure compatible with both our leakage model and previous observations is that of a helmet streamer that, as in the solar case, can occur at the top of the X-ray-emitting, stellar-sized coronal loops of one of the stars. The streamer may extend up to 20 R and interact with the corona of the other star at periastron passage, causing recurring flares. The inferred magnetic field strength at the two mirror points of the helmet streamer is in the range 0.12 - 125 G, and the corresponding Lorentz factor, gamma, of the partially trapped electrons is in the range 20 < gamma < 632. We therefore rule out that the emission could be of gyro-synchrotron nature: the derived high Lorentz factor proves that the nature of the emission at 90 GHz from this pre-main binary system is synchrotron radiation. Based on observations carried out with the IRAM Plateau de Bure Interferometer. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain).Comment: 8 pages, 5 figures, A&A in pres

    Interacting coronae of two T Tauri stars: first observational evidence for solar-like helmet streamers

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    Context {The young binary system V773 Tau A exhibits a persistent radio flaring activity that gradually increases from a level of a few mJy at apoastron to more than 100 mJy at periastron. Interbinary collisions between very large (> 15 R) magnetic structures anchored on the two rotating stars of the system have been proposed to be the origin of these periodic radio flares. Magnetic structures extended over tens of stellar radii, that can also account for the observed fast decay of the radio flares, seem to correspond to the typical solar semi-open quite extended magnetic configurations called helmet streamers.} Aims {We aim to find direct observational evidence for the postulated, solar-like, coronal topologies.} Methods {We performed seven-consecutive-day VLBI observations at 8.4 GHz using an array consisting of the VLBA and the 100-m Effelsberg telescope.} Results {Two distintive structures appear in the radio images here presented. They happen to be associated with the primary and secondary stars of the V773 Tau A system. In one image (Fig.2-B) the two features are extended up to 18 R each and are nearly parallel revealing the presence of two interacting helmet streamers. One image (Fig.2-E) taken a few hours after a flare monitored by the 100-m Effelsberg telescope shows one elongated fading structure substantially rotated with respect to those seen in the B run. The same decay scenario is seen in Fig.2-G for the helmet streamer associated with the other star.} Conclusions {This is the very first direct evidence revealing that even if the flare origin is magnetic reconnection due to interbinary collision, both stars independently emit in the radio range with structures of their own. These structures are helmet streamers, observed for the first time in stars other than the Sun.}Comment: 7 pages, 3 figures, A&A in pres

    Primary ileal lymphoma as a cause of recurrent ileocecal

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    INTRODUÇÃO: A intussuscepção ocorre quando um segmento proximal do intestino invagina para dentro do lúmen do segmento distal adjacente. Esta patologia é relativamente comum em crianças, sendo geralmente idiopática, diferentemente do que é evidenciado em adolescentes e adultos, os quais apresentam uma causa orgânica comprovada na maioria dos casos. O linfoma intestinal como etiologia desta patologia é extremamente raro. RELATO DE CASO: Um paciente de 16 anos, masculino, referindo dor abdominal em quadrante inferior direito há 36 horas associada a vômitos e fezes com sangue vivo compareceu em nosso serviço. O exame físico se apresentava dentro da normalidade exceto por uma massa palpável no quadrante inferior direito. A ultra-sonografia abdominal revelou intussuscepção ileocecal. A colonoscopia demonstrou uma massa protuberante proveniente do orifício da válvula ileocecal que foi reduzida, tendo o paciente um alívio completo dos sintomas. Três semanas após, o paciente retornou ao nosso hospital com recorrência dos sintomas. Uma laparotomia exploradora foi realizada evidenciando uma massa polipóide no íleo terminal com intussuscepção para dentro do ceco. Uma colectomia direita ampliada foi realizada. Após exame patológico da peça e estadiamento tumoral, um linfoma de Burkitt primário foi diagnosticado. A recuperação pós-operatória não apresentou intercorrências e o paciente foi encaminhado para quimioterapia adjuvante.INTRODUCTION: Intussusception occurs when a proximal segment of bowel telescopes into the lumen of the adjacent distal segment. It is common in children being usually idiophatic, in contrast to adolescents and adults, who have a demonstrable etiology in most cases. Intestinal lymphoma is an unusual cause of intussusception in adolescents and adults. CASE REPORT: A 16 year-old male presented with right lower quadrant abdominal pain lasting for 36 hours, with vomiting and bloody stool. Physical examination was unremarkable except for a palpable mass at the right lower quadrant. Abdominal sonography revealed ileocecal intussusception. Colonoscopy showed a protruding mass from the orifice of ileocecal valve which was reduced, and the patient had full withdrawal of symptoms. Three weeks later, the patient came back to our hospital with recurrent symptoms. Laparotomy was performed and a polypoid mass was noted at the terminal ileum with intussusception into the cecum. A right hemicolectomy was performed. After pathologic examination and tumor staging, a primary Burkitt lymphoma of the distal ileum was diagnosed. Postoperative convalescence was uneventful and the patient was referred to adjuvant chemotherapy

    Effects of high levels of environmental air pollution on ocular surface of traffic controllers and taxi drivers in Sao Paulo city

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    Objetivo: Avaliar os efeitos de níveis altos de poluição ambiental do ar na superfície ocular de controladores de tráfego e taxistas da cidade de São Paulo, incluindo avaliação de sinais e sintomas, da osmolaridade lacrimal e da quantidade de células caliciformes obtidas na citologia de impressão conjunctival. Verificar a correlação destes achados entre si e com os níveis de dióxido de nitrogênio (NO2), e de material particulado menor que 2,5 ?m (PM2,5) a que foram expostos. Métodos: Taxistas e controladores de tráfego de São Paulo, Brasil participaram do estudo. Foram mensuradas as médias individuais de 24 horas de exposição ao NO2 e ao PM2,5 em quatro diferentes ocasiões. Na primeira e terceira visitas, os indivíduos foram submetidos ao questionário Ocular Surface Disease Index (OSDI), avaliação na lâmpada de fenda, estimação do tempo de ruptura do filme lacrimal (TRFL), teste de Schirmer e tingimento com corantes vitais da córnea e conjuntiva. Na segunda e quartas visitas, amostras de lágrima foram coletadas do olho direito para análise da osmolaridade, enquanto amostras de citologias de impressão conjuntivais foram coletadas do olho esquerdo. Para estimar os efeitos dos poluentes (PM2,5 e NO2) nos desfechos ao longo do período do estudo adotamos equações de estimativas generalizadas considerando efeitos fixos para medidas repetidas. Correlações entre os níveis de NO2 ou PM2,5, os achados clínicos, o valor da osmolaridade lacrimal e a quantidade de células caliciformes foram investigadas. Resultados: Setenta e um taxistas e controladores de tráfego, entre 31 e 65 anos de idade, foram incluídos no estudo. Os níveis de exposição à poluição do ar permaneceram muito elevados, como notado pelos níveis médios de PM2,5 de 40 ?g/m3 e pelos níveis médios de NO2 constantemente acima de 100 ?g/m3 durante todo o estudo. Poucos sintomas foram relatados no questionário OSDI com pontuação (média ± desvio padrão) de 9,18 ± 6,81 e 8,27 ± 11,92 na primeira e terceira visita, respectivamente. O TRFL foi reduzido com valores médios de 5 segundos, enquanto o teste de Schirmer apresentou valores médios acima de 10 mm com ampla variabilidade. O tingimento com corante vital fluoresceína foi menor do que quatro em todos os olhos, exceto por um (0,7%) indivíduo com pontuação de 5. A pontuação do corante vital lissamina verde foi normal em 124 (87,3%) olhos na primeira visita e em 120 (84,5%) olhos na terceira visita. Os resultados do análise da osmolaridade lacrimal na segunda e quarta visitas foram dentro dos limites da normalidade com médias ± desvio padrão de 298,56 ± 23,19 e 303,73 ± 23,52 mOsmol/Kg, respectivamente. No que se refere a densidade de células caliciformes, os valores médios ± desvio padrão foram 464,42 ± 256,66 e 407,82 ± 269,18 xx células/mm2 na conjuntiva bulbar e 735,52 ± 295,87 e 707,92 ± 272,51 células/mm2 na conjuntiva tarsal, na segunda e quarta visita, respectivamente. Uma significativa e negativa correlação foi encontrada entre PM2,5 e osmolaridade lacrimal (p<0.05). Um aumento de 10 ?m/m3 nos níveis de PM2,5 foi associado a uma diminuição de 10,9 mOsmol/Kg na osmolaridade lacrimal. Também houve uma correlação negativa, embora não estatisticamente significativa, entre NO2 e osmolaridade lacrimal. Nenhuma correlação foi encontrada entre a contagem de células caliciformes conjuntivais e os níveis de NO2 ou PM2,5 assim como nenhuma correlação foi encontrada entre o questionário OSDI ou os achados clínicos e a exposição à poluição do ar. Conclusão: Exposição à altos níveis de poluição do ar diminui a osmolaridade do filme lacrimal e influencia a estabilidade do filme lacrimal embora não seja acompanhada de sintomais e outros sinais clínicos em indivíduos sem doenças oculares. Alterações no filme lacrimal associado com modificações na densidade de células caliciformes podem fazer parte de uma resposta adaptativa da superfície ocular a exposição à poluição do arPurpose: To evaluate the effect of high levels of environmental air pollution on ocular surface of taxi drivers and traffic controllers of São Paulo, including the assessment of signs and symptoms, tear osmolarity assays, and goblet cells count from conjunctival impression cytology. To verify whether there is correlation between such findings as well as with nitrogen dioxide (NO2) levels and particulate matter smaller than 2.5 ?m (PM2.5) levels to which they were exposed. Methods: Taxi drivers and traffic controllers from São Paulo, Brazil were enrolled into the study. Mean individual levels of 24-hours exposure to nitrogen dioxide (NO2) and particulate matter smaller than 2.5 ?m (PM2.5) were assessed on 4 different occasions. On the first and third visits, subjects were submitted to clinical evaluations including the administration of the Ocular Surface Disease Index (OSDI) questionnaire, slit-lamp examination, estimation of tear breakup time (BUT), the Schirmer test, and vital staining of the cornea and conjunctiva. On the second and fourth visits, tear samples were collected from right eye for osmolarity assays, while conjunctival impression cytology was collected from left eye. To estimate the effect of the air pollutants (NO2 and PM2.5) on the endpoints throughout the study generalized estimating equations were adopted. Correlations between NO2 or PM2.5 levels, clinical findings, tear osmolarity and goblet cells density were investigated. Results: Seventy-one taxi drivers and traffic controllers, aged from 31 to 65, were enrolled in the study. Air pollution exposure levels remained very high, as noted by the mean PM2.5 levels of 40 ?m/m3 and the mean NO2 levels constantly above of 100 ?m/m3 during the period of study. Few symptoms were reported in the OSDI questionnaire with score (mean ± standard deviation) of 9.18 ± 6.81 e 8.27 ± 11.92 at the first and third visit, respectively. BUT was low with mean values of 5 seconds, while Schirmer test showed mean values above 10 mm with wide variability. The corneal vital staining score with fluorescein was inferior to 4 in all but one eye (0.7%) with a score of 5. The conjunctival vital staining score with lissamine green was considered normal in 124 eyes (87.3%) in the first visit and in 120 eyes (84.5%) in the third visit. The results of the osmolarity assay at the second and fourth visits were within normal limits with mean ± standard deviation of 298.56 ± 23.19 and 303.72 ± 23.52 mOsmol/kg, respectively. Regarding goblet cells density, the mean ± standard deviation values were 464.42 ± 256.66 and 407.82 ± 269.18 cells/mm2 on bulbar conjunctiva and 735.52 ± 295.87 and 707.92 ± 272.51 cells/mm2 on the tarsal conjunctiva, at the second and fourth visit, respectively. A significant and negative correlation was found between PM2.5 and tear film osmolarity (p<0.05). xxiii An increase of 10 ?m/m3 in PM2.5 levels was associated with 10.9 mOsmol/Kg decrease in tear osmolarity. There also was a negative correlation, though not statistically significant, between NO2 and tear osmolarity No correlation was found between conjunctival goblet cells count and NO2 or PM2.5 levels as well as no correlation was found between OSDI questionnaire or clinical findings and air pollution exposure. Conclusion: Exposure to high levels of air pollution reduces tear film osmolarity and influences tear film stability, although it is not associated with symptoms and other clinical signs in individual without ocular disease. Alterations on tear film osmolarity combined to goblet cells density modification may be part of an adaptive ocular surface response to air pollution exposur

    Brazilian Abstracts Presented at the American Urological Association Annual Meetings: Contribution, Publication Rates, and Comparison with Oncology Abstracts

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    Purpose Scientific research originating from Brazil appears to be rising in several medical fields. Research results are often presented at scientific meetings before publication in peer-reviewed journals. We investigated the publication rate of Brazilian studies presented in American Urological Association (AUA) meetings and compared with the rate of publication of Brazilian oncological studies presented at the American Society of Clinical Oncology (ASCO) meetings. Materials and Methods a hand search of 12,454 abstracts presented at aua meetings 2001-2007 was conducted. abstracts for which at least two-thirds of institutions were from brazil were considered as brazilian. final publication was searched in pubmed and lilacs databases. oncological abstracts were also hand searched in the asco meetings proceedings in the same years. Results There was no significant temporal trend in the proportion of AUA studies originating from Brazil along those 7 years. A total of 195 abstracts (1.57%) were from Brazil. One hundred (51.3%) abstracts were published in full, and the estimated 5-year publication rate was 48.2%. There was a progressive increase in publication rates for studies categorized as video, poster, and podium presentations. Considering abstracts presented in years 2001-2005, urologic publication rate was significantly higher than for abstracts presented at the ASCO meeting. Conclusions Our results suggest that the Brazilian contribution to AUA meetings is at a plateau and that the Brazilian literature contribution is greater in urology than in oncology. Efforts must be invested towards raising this plateau and understanding qualitative aspects of the urology scientific output from Brazil

    Comparison between optical coherence tomography angiography and fluorescein angiography findings in retinal vasculitis

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    Abstract Background To describe optical coherence tomography angiography (OCT-A) findings in patients with retinal vasculitis and to compare them to current fluorescein angiography (FA) findings. Methods This was an observational case series. Nineteen eyes in 10 patients with retinal vasculitis of various etiologies were imaged with FA (TRC-50DX, Topcon) and OCT-A (SD-OCT, Optovue). The images were reviewed and analyzed. Results The mean age was 36 years (range 24–67 years); there were three males and seven females. The primary vessels involved were veins (89%). Fourteen eyes (74%) had active inflammatory disease during the study period, with signs of vascular sheathing and perivascular leakage on FA. Interestingly, in this group, OCT-A was not able to detect clear signs of active inflammation around the affected vessels. Nevertheless, OCT-A was able to detect secondary lesions in fourteen eyes (74%), including some findings not clearly shown on FA. Most of these were within the macular area. OCT-A was particularly effective in cases of capillary dropout, increased foveal avascular zone, telangiectasias, shunts, and areas of neovascularization. Conclusion FA remains an essential complementary exam for detection of retinal vasculitis. However, OCT-A extends FA findings and affords better assessment of secondary complications
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