RESUMO
A pseudoscopic (inverted depth) image made with spiral diffracting elements intermediated by a pinhole is explained by its symmetry properties. The whole process is made under common white light illumination and allows the projection of images. The analysis of this projection demonstrates that the images of two objects pointing away longitudinally have the main features of standard pseudoscopic image points. An orthoscopic (normal depth) image has also been obtained with the breaking of the symmetry conditions.
RESUMO
Pseudoscopic (inverted depth) images that keep a continuous parallax were shown to be possible by use of a double diffraction process intermediated by a slit. One diffraction grating directing light to the slit acts as a wavelength encoder of views, while a second diffraction grating decodes the projected image. The process results in the enlargement of the image under common white light illumination up to infinite magnification at a critical point. We show that this point corresponds to another simple-symmetry object-observer system. Our treatment allows us to explain the experience by just dealing with main ray directions.
RESUMO
We report a retrospective review of eight patients (one male), aged 19 to 31 years old, with systemic toxocariasis (visceral larva migrans), seen at the Salvador Hospital of Santiago. Four cases had heart involvement, three had lung involvement and in two, several organs were affected. Seven cases had leukocytosis (range 14, 5 to 160 x 10(9)/l) and all had eosinophilia (35 to 90%). Serum ELISA titers for Toxocara sp were positive in all cases, ranging from 64 to 1000. Six patients were treated with thiabendazole and one with albendazole. Steroids or hydroxiurea were administered to patients with heart failure or hyperleukocytosis. Subjects with lung involvement recovered quickly but those with cardiac compromise had a partial recovery with frequent decompensations of their cardiac failure and one death. Eosinophilia lasted up to 20 years, in spite of specific treatment. We emphasize the importance of infection prevention, accuracy of diagnosis and the severity of cardiac damage in the adult patient.
Assuntos
Larva Migrans Visceral/complicações , Larva Migrans Visceral/diagnóstico , Adulto , Ecocardiografia Doppler , Eosinofilia/parasitologia , Feminino , Insuficiência Cardíaca/parasitologia , Humanos , Masculino , Estudos RetrospectivosRESUMO
With the objective of defining the intrafamiliar distribution pattern of the infection and illness caused by Toxocara sp., 78 infected families (356 people) were studied for 30 months. At the same time 28 families free of infection were studied, as a control group (97 people). The socioeconomic level was analyzed according to a modified Graffar index. Contac with canine and feline pets, and antecedents of geophagia and onichophagia were found to be risk factors which would facilitate the infection. The average of persons infected, diagnosed by ELISA Toxocara test, was 2.8 per family. The importance of familiar distribution of the infection and its primary prevention is strongly stressed.
Assuntos
Toxocaríase/epidemiologia , Adolescente , Adulto , Idoso , Animais , Estudos de Casos e Controles , Criança , Chile/epidemiologia , Saúde da Família , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Prospectivos , Fatores de Risco , Estudos Soroepidemiológicos , Fatores Socioeconômicos , Toxocara canis/imunologia , Toxocaríase/sangueAssuntos
Creches , Giardíase/epidemiologia , Adulto , Pré-Escolar , Chile , Feminino , Giardíase/tratamento farmacológico , Giardíase/transmissão , Humanos , Lactente , Masculino , Metronidazol/uso terapêutico , RecidivaRESUMO
Se estudiaron clinicamente y mediante examenes de laboratorio 42 ninos infectados por Toxocara sp. La edad promedio de los casos fue de 4 anos 2 meses +/- 3 anos 5 meses. Habia geofagia en 97,6%, grados variables de compromiso pulmonar en 64,3% y hepatomegalia en 59,5% de los pacientes.El fondo de ojos tenia alteraciones en 4,8% de los pacientes. En el hemograma la concentracion de hemoglobina promedio fue de 11,0 g/dl, el recuento de leucocitos promedio 19.213 x mm3 y el de eosinofilos 8.918,9 x mm3. 84,86% de los ninos presentaron niveles de isohemaglutininas > o igual 1:64 y 95,2% titulos de ELISA para Toxocara superiores a esta dilucion. El tratamiento con tiabendazol fue bien tolerado en 83,3% y efectivo en 70,8% de los ninos. En 29,2% se observo mejoria parcial clinica y de laboratorio