Computer visual syndrome in graduate students of a private university in Lima, Perú.

BACKGROUND: In recent decades, several studies have found a strong association between prolonged use of video display terminals and ophthalmological symptoms encompassed in the so-called computer visual syndrome (CVS). Few studies have addressed this syndrome in graduate students. METHODS: Observational, cross-sectional descriptive study. A total of 106 postgraduate students were surveyed without ophthalmological pathologies. The diagnosis of CVS was made by means of the questionnaire of Seguí et al. validated in Spanish, which evaluates the frequency and intensity of 16 ocular symptoms. RESULTS: The prevalence of CVS among graduate university students was 62.3% (95% CI: 52.3-71.5). It was found that the highest proportion of students with the syndrome was in the group of older than 40 years old (88.2%) and in the group 21-30 years old (70.0%), showing statistically significant differences (p = 0.004). According to the device and its time of use, students who used the mobile phone for 7-10 h a day showed a higher prevalence of CVS compared to those who used the device for less time (p = 0.030). The business School had the highest prevalence (75.0%). CONCLUSION: Three out of every five graduate students presented CVS with this prevalence being like reported in other populations. There is a need to investigate possible interventions that can help reduce this entity.

Computer visual syndrome in graduate students of a private university in Lima, Perú. / Síndrome visual informático en estudiantes universitarios de posgrado de una universidad privada de Lima, Perú.

BACKGROUND: In recent decades, several studies have found a strong association between prolonged use of video display terminals and ophthalmological symptoms encompassed in the so-called computer visual syndrome (CVS). Few studies have addressed this syndrome in graduate students. METHODS: Observational, cross-sectional descriptive study. A total of 106 postgraduate students were surveyed without ophthalmological pathologies. The diagnosis of CVS was made by means of the questionnaire of Seguí et al. validated in Spanish, which evaluates the frequency and intensity of 16 ocular symptoms. RESULTS: The prevalence of CVS among graduate university students was 62.3% (95% CI: 52.3-71.5). It was found that the highest proportion of students with the syndrome was in the group of older than 40 years old (88.2%) and in the group 21-30 years old (70.0%), showing statistically significant differences (p=0.004). According to the device and its time of use, students who used the mobile phone for 7 to 10hours a day showed a higher prevalence of CVS compared to those who used the device for less time (p=0.030). The business School had the highest prevalence (75.0%). CONCLUSION: Three out of every five graduate students presented CVS with this prevalence being like reported in other populations. There is a need to investigate possible interventions that can help reduce this entity.

Síndrome visual informático en estudiantes universitarios de posgrado de una universidad privada de Lima, Perú / Computer visual syndrome in graduate students of a private university in Lima, Perú

Antecedente En las últimas décadas diversos estudios han encontrado una fuerte asociación entre el uso prolongado de los videoterminales y síntomas oftalmológicos englobados en el denominado síndrome visual informático (SVI). Pocos estudios han abordado este síndrome en estudiantes de posgrado. Métodos Estudio observacional, descriptivo de corte transversal. Se encuestó a 106 estudiantes universitarios de posgrado sin patologías oftalmológicas. El diagnóstico de SVI se realizó mediante el cuestionario de Seguí et al. validado en castellano, el cual evalúa la frecuencia e intensidad de 16 síntomas oculares. Resultados La prevalencia de SVI de los estudiantes universitarios de posgrado fue del 62,3% (IC 95%: 52,3-71,5). Se encontró que la mayor proporción de estudiantes con el síndrome estuvo en el grupo mayor de 40 años (88,2%) y en el grupo de 21-30 años (70,0%), mostrando diferencias estadísticamente significativas (p=0,004). Según el dispositivo y su tiempo de uso se observó que los estudiantes que utilizaban el teléfono móvil de 7 a 10h diarias presentaron una prevalencia de SVI mayor en comparación con quienes utilizaban el dispositivo menos tiempo (p=0,030). La Facultad de Ciencias Empresariales presentó la prevalencia más elevada (75,0%). Conclusión Tres de cada cinco estudiantes universitarios de posgrado presentaron SVI, siendo esta prevalencia similar a lo reportado en otras poblaciones. Es necesario que se investiguen posibles intervenciones que puedan ayudar a reducir esta entidad (AU)

Background In recent decades, several studies have found a strong association between prolonged use of video display terminals and ophthalmological symptoms encompassed in the so-called computer visual syndrome (CVS). Few studies have addressed this syndrome in graduate students. Methods Observational, cross-sectional descriptive study. A total of 106 postgraduate students were surveyed without ophthalmological pathologies. The diagnosis of CVS was made by means of the questionnaire of Seguí et al. validated in Spanish, which evaluates the frequency and intensity of 16 ocular symptoms. Results The prevalence of CVS among graduate university students was 62.3% (95% CI: 52.3-71.5). It was found that the highest proportion of students with the syndrome was in the group of older than 40 years old (88.2%) and in the group 21-30 years old (70.0%), showing statistically significant differences (p=0.004). According to the device and its time of use, students who used the mobile phone for 7 to 10hours a day showed a higher prevalence of CVS compared to those who used the device for less time (p=0.030). The business School had the highest prevalence (75.0%). Conclusion Three out of every five graduate students presented CVS with this prevalence being like reported in other populations. There is a need to investigate possible interventions that can help reduce this entity (AU)

Intradermal injection of Bothrops cotiara venom in mice in an experimental wound model

Bothropic envenomation induces hemorrhage, coagulant disturbances and necrosis. Regarding therapies against the local damage caused by the venom, there is little information on tissue changes until the complete healing. In the current study, local damage was evaluated by examination of morphological inflammatory alterations, mast cell count, and analysis of collagen deposition. Bleeding was evident four hours after inoculation. After 24 hours, a large area of injury appeared presenting disorganized tissue, significant hemorrhage and acute inflammation. After three days, the damaged area was extensive, with a large amount of inflammatory cells and the presence of scab. In seven days, healing and reepithelization process started. And, 21 days later, the epithelium showed less infiltration and no skin appendages. The number of mast cells was similar to control after four hours, with a drop of 50 percent at 24 hours, followed by an increase until the 21st day. No differences of collagen deposition were observed among experimental groups. Taken together, wound healing after intradermal injection of Bothrops cotiara venom in mice follows similar parameters to wounds caused by other bothropic venoms. The present work reveals the importance of experimental wound models to the study of neutralizing agents against venom toxins.

A C-type lectin from Bothrops jararacussu venom can adhere to extracellular matrix proteins and induce the rolling of leukocytes

Purification of a lectin from Bothrops jararacussu venom (BjcuL) was carried out using agarose-D-galactose affinity gel. MALDI-TOF gave a major signal at m/z 32028, suggesting the presence of a dimmer composed of two identical subunits. Divalent cations were required for the lectin activity, as complete absence of such ions reduced hemagglutination. BjcuL was more effective at neutral pH and showed total loss of activity at pH values below 4.0 and above 9.0. Its agglutinating activity remained stable at 25°C until 60min, but increased when at 35°C for at least 15min. Adhesion assays to extracellular matrix (ECM) glycoproteins showed that the biotinylated lectin (0.039-5.0µg/100µl) was capable of binding to fibronectin and vitronectin in a dose-dependent manner. The binding was partially inhibited in the presence of D-galactose. BjcuL (1.25-10µg/30µl) potential was investigated for leukocyte rolling and adhesion to endothelial cells in living microvessels using intravital microscopy, which showed that it induced a dose-dependent increase in rolling and adherence of leukocytes, acting directly on endothelial cells of postcapillary venules. The specific association between lectins and their ligands, either on the cell surface or on the ECM, is related to a variety of biological processes. The complementary characterization of BjcuL, shown here, is useful to further understand the venom effects and as a background for future investigation for therapeutic strategies.

Mast cell degranulation induced by lectins: effect on neutrophil recruitment.

The mammalian lectin macrophage-derived neutrophil chemotactic factor (MNCF) and the plant lectin KM+ were characterized for their ability to activate and degranulate mast cells. The association between mast cell activation and the induction of neutrophil migration was also investigated. Incubation of rat peritoneal mast cells with these lectins resulted in degranulation and mediator release. By confocal microscopy, both lectins were evenly distributed on the cell surface. MNCF activated RBL-2H3 mast cells only if the cells had been sensitized with IgE. KM+ was able to activate either unsensitized or IgE sensitized RBL-2H3 cells. In microplate assays MNCF, but not KM+, bound to rat IgE. In rats that were depleted of mast cells, neutrophil recruitment by MNCF and KM+ were significantly reduced indicating that mast cell activation provides an amplification loop for the neutrophil recruitment induced by these lectins. The present study supports the concept that mammalian lectins play a fundamental role in innate immunity.

Sm60, a mannose-binding protein from Schistosoma mansoni with inflammatory property.

We demonstrate here that a mannose-binding protein from Schistosoma mansoni, termed Sm60, was recovered in the mannose-eluted fraction (Man(+)) upon affinity chromatography on immobilised mannose of the soluble antigen fraction from adult worm tegument and cercariae. Sm60 was detected in the Man(+) fraction as a prominent doublet with an apparent molecular mass of 60-66 kDa by SDS-PAGE and appeared as a single band with a pI of approximately 6.9 by isoelectrofocusing. Sm60 was also detected in preparations of schistosomula extract and soluble egg antigens using a mouse polyclonal anti-Sm60 serum on immunoblotting assay. This antiserum demonstrated that Sm60 was localised on the tegument of S. mansoni adult worm. In order to determine the role of Sm60 in host-parasite interactions, we showed that Sm60 induced in vitro migration of human neutrophil in a dose-dependent manner and in vitro mast cell degranulation. Sm60 triggered these activities through its carbohydrate-binding site, since these activities were selectively inhibited by 0.2 M D-mannose, but not by 0.2 M D-galactose. Furthermore, Sm60 induced in vivo neutrophil migration. In contrast, mast cell-depleted rats presented a significant reduction of the neutrophil migration induced by Sm60 as compared with non-depleted controls. These data suggest that in vivo neutrophil migration induced by Sm60 is modulated by mast cell-dependent mechanisms. Sm60 might play a key role in the host-parasite interaction, and its characterization opens perspective to examine the role of this molecule in the biology of S. mansoni.

Identification and isolation of rat bone marrow-derived mast cells using the mast cell-specific monoclonal antibody AA4.

Previous studies of mast cell maturation, structure, and function have been hampered by the lack of mast cell-specific markers. In this study, using a well-characterized mast cell-specific monoclonal antibody, MAb AA4, mast cells from rat bone marrow in various stages of maturation were isolated and characterized. The very immature mast cells, which have not been previously described, contained few granules and would not be recognized as mast cells by standard cytological methods. Pure populations of mast cells were isolated from the bone marrow using MAb AA4-conjugated magnetic beads. The same stages of maturation were observed in the isolated mast cells as were seen in the unfractionated bone marrow. All of these cells were immunopositive for the alpha-subunit of Fc epsilon RI, IgE, and c-kit, confirming their identity as mast cells. By direct counting of immunolabled cells and by flow cytometry, approximately 2.4% of the cells in the bone marrow are mast cells. Staining with toluidine blue and berberine sulfate, as well as RT-PCR of the cells, indicates that these cells are connective tissue-type mast cells. The use of immunological methods for identification of mast cell precursors should facilitate the study of these cells. (J Histochem Cytochem 49:219-228, 2001)

Immunomagnetic isolation of rat bone marrow-derived and peritoneal mast cells.

Mast cells are difficult to purify from heterogeneous cell populations and to preserve, especially for pre-embedding immunostaining at the ultrastructural level. We have developed a technique that permits the isolation of a pure population of mast cells suitable for immunocytochemical studies. A rat mast cell-specific monoclonal antibody (MAb AA4) conjugated to tosylactivated Dynabeads 450 was used to immunomagnetically separate mast cells from rat bone marrow and peritoneal cell suspensions. Approximately 85% of the mast cells were recovered in the positive population that comprised virtually pure mast cells. After microwave fixation, morphological examination showed that the cells were intact and retained their ultrastructural detail. Mast cells in all stages of maturation were immunolabeled with a panel of antibodies after immunomagnetic separation. The combination of immunomagnetic separation followed by immunostaining should prove useful for the study of mast cell maturation and for the characterization of other specific cell types that are present in tissues in only limited numbers.