RESUMO
Photonic crystals are some of the more spectacular realizations that periodic arrays can change the behavior of electromagnetic waves. In nature, so-called structural colors appear in insects and even plants. Some species create beautiful color patterns as part of biological behavior such as reproduction or defense mechanisms as a form of biomimetics. The interaction between light and matter occurs at the surface, producing diffraction, interference and reflectance, and light transmission is possible under suitable conditions. In particular, there are two Colombian butterflies, Morpho cypris and Greta oto, that exhibit iridescence phenomena on their wings, and in this work, we relate these phenomena to the photonic effect. The experimental and theoretical approaches of the optical response visible region were studied to understand the underlying mechanism behind the light-matter interaction on the wings of these Colombian butterflies. Our results can guide the design of novel devices that use iridescence as angular filters or even for cosmetic purposes.
Assuntos
Borboletas/anatomia & histologia , Asas de Animais/anatomia & histologia , Animais , Borboletas/química , Borboletas/fisiologia , Borboletas/ultraestrutura , Cristalização , Iridescência , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Fótons , Pigmentação , Asas de Animais/química , Asas de Animais/fisiologia , Asas de Animais/ultraestruturaRESUMO
La capacidad de los leucócitos de abandonar la circulación y migrar hacia los tejidos es un paso crítica de la respuesta inmune. La L-selectina, selectina leucocitaria (CD62L), media la unión de linfócitos a las vÛnulas endoteliales altas de los ganglios linfáticos periféricos, y también participa en la adhesión de linfócitos, neutrófilos y monócitos al endotelio vascular activado en los sítios de inflamación. En este trabajo se estudiaron los niveles de expresión de L- selectina sobre los linfócitos T y polimorfonucleares neutrófilos en 25 niños HIV (+) sin tratamiento antirretroviral y 25 niños sanos HIV (-), avaluando además su comportamiento en 10 de los pacientes, luego de 6 meses de iniciada la terapéutica específica para el HIV. El número de linfócitos TCD3+, CD4+ y CD8+ que expresan CD62L se encontró significativamente disminuido en los niños HIV(+) con respecto al grupo control. El porcentaje de neutrófilos que expresan CD62L se encontro significativamente disminuido en los pacientes con mayor compromiso inmunológico. Se observó una correlación positiva entre los niveles de LTCD4+ y el porcentaje de neutrófilos que expresan CD62L. Luego de 6 meses de tratamiento antirretroviral no hubo cÔmbios significatios en los niveles de expresión de CD62L sobre LTCD4+ y LTCD8+ . La reducción en los niveles de expresión de L-selectina en estos tipos celulares sugiere que durante la infección por HIV las funciones leucocitarias tales como la migración y el asentamiento linfocitario son anormales, contribuyendo al progresivo deterioro inmune. (AU)
Assuntos
Lactente , Pré-Escolar , Criança , Humanos , Masculino , Feminino , Selectina L/sangue , Linfócitos T/imunologia , Neutrófilos/imunologia , Infecções por HIV/sangue , Selectina L/imunologia , Infecções por HIV/imunologiaRESUMO
La capacidad de los leucócitos de abandonar la circulación y migrar hacia los tejidos es un paso crítica de la respuesta inmune. La L-selectina, selectina leucocitaria (CD62L), media la unión de linfócitos a las vênulas endoteliales altas de los ganglios linfáticos periféricos, y también participa en la adhesión de linfócitos, neutrófilos y monócitos al endotelio vascular activado en los sítios de inflamación. En este trabajo se estudiaron los niveles de expresión de L- selectina sobre los linfócitos T y polimorfonucleares neutrófilos en 25 niños HIV (+) sin tratamiento antirretroviral y 25 niños sanos HIV (-), avaluando además su comportamiento en 10 de los pacientes, luego de 6 meses de iniciada la terapéutica específica para el HIV. El número de linfócitos TCD3+, CD4+ y CD8+ que expresan CD62L se encontró significativamente disminuido en los niños HIV(+) con respecto al grupo control. El porcentaje de neutrófilos que expresan CD62L se encontro significativamente disminuido en los pacientes con mayor compromiso inmunológico. Se observó una correlación positiva entre los niveles de LTCD4+ y el porcentaje de neutrófilos que expresan CD62L. Luego de 6 meses de tratamiento antirretroviral no hubo câmbios significatios en los niveles de expresión de CD62L sobre LTCD4+ y LTCD8+ . La reducción en los niveles de expresión de L-selectina en estos tipos celulares sugiere que durante la infección por HIV las funciones leucocitarias tales como la migración y el asentamiento linfocitario son anormales, contribuyendo al progresivo deterioro inmune.
Assuntos
Lactente , Pré-Escolar , Criança , Humanos , Masculino , Feminino , Infecções por HIV/sangue , Selectina L/sangue , Neutrófilos/imunologia , Linfócitos T/imunologia , Infecções por HIV/imunologia , Selectina L/imunologiaRESUMO
L-selectin is an adhesion molecule that is responsible for the initial attachment of leukocytes to endothelium. After leukocyte activation L-selectin is endoproteolytically released from the cell surface. In order to analyze the relationship between soluble L-selectin (sL-selectin) and parameters of immune activation and disease progression, 51 HIV infected children and 15 healthy controls were studied. Serum L-selectin concentrations were significantly higher in HIV infected children than in the control group. Levels of sL-selectin were higher in HIV infected patients with severe immunologic suppression than in those with moderate or no evidence of suppression. A positive correlation between sL-selectin levels and LTCD8 counts, sL-selectin and soluble intercellular adhesion molecule-1 (sICAM-1) and immunogobulin A (IgA) levels was detected. On the contrary sL-selectin concentration did not correlate with plasmatic viral load. The correlation with parameters of immune activation may implicate involvement of sL-selectin in the immunopathogenesis of HIV infection.
Assuntos
Infecções por HIV/metabolismo , HIV/imunologia , Selectina L/sangue , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Criança , Pré-Escolar , Feminino , Infecções por HIV/imunologia , Humanos , Imunoglobulina A/sangue , Imunoglobulina A/imunologia , Imunoglobulina A/metabolismo , Lactente , Molécula 1 de Adesão Intercelular/sangue , Molécula 1 de Adesão Intercelular/imunologia , Molécula 1 de Adesão Intercelular/metabolismo , Selectina L/imunologia , Selectina L/metabolismo , Masculino , Solubilidade , Carga ViralRESUMO
The effect of Fasciola hepatica parasite burden on the detection of excretory/secretory (E/S) antigens in sera and feces of experimentally infected sheep was evaluated using a double antibody-based capture enzyme-linked immunosorbent assay (ELISA). Four groups of five sheep each were used. The first three groups were infected with 50, 100 and 200 metacercariae of F. hepatica, and the fourth group remained as non-infected control. On the day of infection and weekly thereafter, serum and fecal samples were taken. ELISA detected F. hepatica E/S antigen levels in serum from the first week post-infection (wpi) and in fecal supernatant from the fourth wpi, which were significantly (p<0.05) higher than controls. F. hepatica eggs were not detected until after the eighth wpi. The correlation between absorbance of E/S antigens in serum with the fluke burden was 0.77 (p<0.0001) and in feces 0.76 (p<0.0001) at 12th wpi. The sensitivity of the assay to detect E/S antigens in serum was 86.6% and in feces 93.3%. It is concluded that the ELISA technique used in this study offers a diagnostic alternative for detecting early infections of F. hepatica in sheep.
Assuntos
Antígenos de Helmintos/análise , Fasciola hepatica/imunologia , Fezes/parasitologia , Doenças dos Ovinos/parasitologia , Animais , Antígenos de Helmintos/sangue , Ensaio de Imunoadsorção Enzimática/veterinária , Fígado/parasitologia , Contagem de Ovos de Parasitas/veterinária , Sensibilidade e Especificidade , OvinosRESUMO
L-selectin is an adhesion molecule that is responsible for the initial attachment of leukocytes to endothelium. After leukocyte activation L-selectin is endoproteolytically released from the cell surface. In order to analyze the relationship between soluble L-selectin (sL-selectin) and parameters of immune activation and disease progression, 51 HIV infected children and 15 healthy controls were studied. Serum L-selectin concentrations were significantly higher in HIV infected children than in the control group. Levels of sL-selectin were higher in HIV infected patients with severe immunologic suppression than in those with moderate or no evidence of suppression. A positive correlation between sL-selectin levels and LTCD8 counts, sL-selectin and soluble intercellular adhesion molecule-1 (sICAM-1) and immunogobulin A (IgA) levels was detected. On the contrary sL-selectin concentration did not correlate with plasmatic viral load. The correlation with parameters of immune activation may implicate involvement of sL-selectin in the immunopathogenesis of HIV infection.
RESUMO
This multicenter, open-label study assessed the clinical efficacy and tolerability of the proton-pump inhibitor rabeprazole 20 mg once daily in 189 patients with functional dyspepsia and normal findings on upper endoscopy. The clinical efficacy rate was 86% after only 4 weeks of treatment, and symptoms remained under control at the end of 4 weeks without treatment. Rabeprazole was well tolerated and was associated with a low incidence (8%) of mild, transient adverse events.
Assuntos
Antiulcerosos/uso terapêutico , Benzimidazóis/uso terapêutico , Dispepsia/tratamento farmacológico , ATPases Translocadoras de Prótons/antagonistas & inibidores , 2-Piridinilmetilsulfinilbenzimidazóis , Dispepsia/complicações , Feminino , Humanos , Masculino , Omeprazol/análogos & derivados , RabeprazolRESUMO
The aim of the present study was to compare the sensitivity, specificity and usefulness of the DIG-ELISA, DOT-ELISA and Indirect ELISA tests for determining the seroprevalence of fasciolosis in cattle under tropical conditions in Mexico. To standardize the tests, positive and negative sera to F. hepatica from 88 Holstein Freisian adult cows located in an enzootic area of fascioliosis and 88 crossbred adult cattle from a fluke-free area were used. For the epidemiological study, 85 crossbred cattle between 1 to 7 years of age were used. Animals were bled every two months, from March 1995 to September 1996 and the sera obtained were stored at -70 degrees C, until used. Indirect ELISA showed a sensitivity of 96.5% and a specificity of 98.8%, DIG-ELISA 97.5% and 80.0% and DOT-ELISA 93.1% and 95.4%, respectively. During 1995, Indirect ELISA yielded the highest levels of IgG anti-F. hepatica antibodies. However, in 1996, after animal treatment with triclabendazole, DIG-ELISA tended to show higher percentages of antibody-positive animals, but it was not significantly different (p>0.05) from the other tests. Comparisons made in parallel to the faecal sedimentation test demonstrated that all serological tests detected higher percentages of positive animals. Only one serum out of ten (10%) of Paramphistomum spp. cross-reacted with the DOT-ELISA test, but no cross-reaction was observed with sera from animals with other parasites. All ELISA tests were highly sensitive and specific; they may be recommended for use in seroepidemiological surveys for F. hepatica.
Assuntos
Anticorpos Anti-Helmínticos/sangue , Doenças dos Bovinos/epidemiologia , Ensaio de Imunoadsorção Enzimática/veterinária , Fasciola hepatica/imunologia , Fasciolíase/veterinária , Animais , Anti-Helmínticos/farmacologia , Anti-Helmínticos/uso terapêutico , Antígenos de Helmintos/biossíntese , Antígenos de Helmintos/química , Benzimidazóis/farmacologia , Benzimidazóis/uso terapêutico , Bovinos , Doenças dos Bovinos/diagnóstico , Reações Cruzadas , Fasciolíase/diagnóstico , Fasciolíase/epidemiologia , Fezes/parasitologia , México/epidemiologia , Contagem de Ovos de Parasitas , Sensibilidade e Especificidade , Estudos Soroepidemiológicos , Triclabendazol , Clima TropicalRESUMO
The strain G89HT of Clostridium argentinense obtained by culture selection of the prototype G89 strain producing high titers of type G botulinal toxin was studied. Its cultural, biochemical and toxigenic characteristics and the presence of plasmids were tested. Both strains showed similar physiological features and carried a 83 MDa plasmid. A 170 MDa plasmid was also recognized in the G89HT strain. Notably, this strain was better sporulating and showed a higher toxigenicity than the prototype G89 C. argentinense strain. These two characteristics might permit a long term storage and perhaps yield high antitoxin titres.
Assuntos
Toxinas Botulínicas/metabolismo , Clostridium/metabolismo , Proteínas de Bactérias/análise , Clostridium/crescimento & desenvolvimento , Clostridium/patogenicidade , Meios de Cultura/metabolismo , Testes de Neutralização , Plasmídeos/genética , Plasmídeos/isolamento & purificação , Esporos Bacterianos/genética , Esporos Bacterianos/crescimento & desenvolvimento , Esporos Bacterianos/metabolismo , Tripsina/metabolismo , Virulência/genéticaRESUMO
A study was performed in order to explore the costs of treating diabetic retinopathy at a large eye hospital in Mexico with a view to identifying opportunities for improving efficiency. Clinical records of a random sample of 69 diabetic patients were reviewed for data on each patient's background, medical history, and treatment; and the costs of all resources utilized in each type of procedure provided were documented and priced. The resulting data on clinical costs was complemented by data on the private costs of treatment (medical fees, accommodation costs, transportation costs, and lost wages) that were gathered from patient interviews. The study found that the patients, who were generally poor, shouldered a substantial economic burden associated with treatment at the hospital; however, less than half this burden was in the form of fees. The rest involved other out-of-pocket expenditures on food, travel, and accommodation (45% of the total) and lost wages (10% of the total). Suggestions for reducing various of these costs without endangering treatment quality are presented. These include suggestions for reducing waiting time; reducing the number of patient visits required by increasing the strength of individual laser treatments, completing more procedures in a single visit, and reviewing hospital policy on fluoroangiograms; and increasing the chances for early and effective treatment by educating at-risk relatives accompanying the patients about the need for early treatment.