Validación de instrumentos como garantía de la credibilidad en las investigaciones científicas / Validation of instruments as a guarantee of credibility in scientific research

La validación de instrumentos, es considerada, por el alcance de su rigor científico, un tipo de estudio con sus características y procedimientos. Este trabajo tiene como finalidad proponer una metodología para la validación de un instrumento científico. Se utilizaron métodos teóricos como el histórico lógico y el analítico sintético, y desde la empírea, al análisis de documentos, los cuales permitieron arribar a la metodología propuesta. Los resultados fundamentales están asociados con una estructura secuencial, de estricto cumplimiento para asegurar que el instrumento esté validado y así obtener resultados avalados desde la ciencia(AU)

Instrument validation is considered, for the scope of its scientific rigor, a type of study with its characteristics and procedures. The purpose of this work is to propose a methodology for the validation of a scientific instrument. Theoretical methods were used, such as the logical historical and the synthetic analytical, and from the empirical, to the analysis of documents, which allowed arriving at the proposed methodology. The main results are associated with a sequential structure of strict compliance to ensure that an instrument is validated, and thus obtain results guaranteed by science(AU)

Prevalencia de asma y enfermedades atópicas en niños de Panamá. Estudio Nacional de Asma y Atopia en niños (ISAAC) fase III

Objetivo: Describir comparativamente la prevalencia del asma y enfermedades atómicas basado en el estudio ISAAC FASE 1 y FASE 111 en niños de 6-7 años y 13-14 años de edad en la República de Panamá Metodología : Se seleccionaron al azar 35 escuelas y colegios en la provincia de Panamá, Herrera, Chiriquí y Veraguas, de la República de Panamá. La información se obtuvo por un cuestionario elaborado usando el protocolo del Estudio Internacional de Asma y Alergia en la niñez (ISAAC). Todos los cuestionarios fueron revisados y los datos fueron transferidos a una base de datos en Epi-Info 6.0 , usando el formato y la codificación de ISAAC. El análisis estadístico de los resultados se efectuó obteniendo las frecuencias de las variables y aplicando la prueba de chi cuadrado. Resultados: Se estudiaron un total de 6155 niños de dos grupos etareos ,de 6-7 años (2941) y de 13 -14 años (3214). La prevalencia del asma en la República de Panamá puede estimarse en niños escolares de 6 a 7 años en 22.7% y de 13-14 años en 22.9% con una prevalencia general de 22.8% (p<0.001). La prevalencia de enfermedades atópicas relacionadas a asma se estimó en 52.6% para la rinitis, conjuntivitis 30.2% y eczema en 27.4% Conclusión: La prevalencia de asma en la República de Panamá comparando los resultados del estudio ISAAC 1997 y 2003 es de 22.8% en niños de 6-7 años y de 20% en niños de 13-14 años.

Objectives: Define the prevalence of asthma and atopic diseases in children 6-7 years and 13-14 years of age in the Republic of Panama according to ISAAC protocols FASE 1 and FASE 111 studies. Material and Methods: We randomly selected 35 elementary schools and junior high schools in the province of Panama, Herrera, Chiriquí and Veraguas of the Republic of Panama. The information was gotten by a questionnaire using the protocol of the International Study of Asthma and Allergy in Children (ISAAC). All questionnaires were reviewed and the data were transferred to a database in Epi-Info 6.0, using the format and the ISAAC code. The Statistical analysis of the results was made obtaining the frequencies of the variables and applying the chi-square test. Results: A total of 6155 children from two age groups, aged 6-7 years (2941) and 13-14 years (3214) were studied. The prevalence of asthma in the Republic of Panama can be estimated in school children from 6 to 7 years in 22.7% and 13-14 years in 22.9% (p<0.001)with a general prevalence of 22.8% (p <0.001). The prevalence of atopic diseases related to asthma was estimated at 52.6% (p<0.001)for rhinitis, conjunctivitis 30.2% and eczema in 27.4%(p<0.001) Conclusion: The data gotten in this study demonstrate a high prevalence of asthma in the Republic of Panama. These data be used in order to evaluate the present and future behavior of these diseases in Panama, and most call attention on the necessity of taking specific measurements for their prevention and management.

Human neutrophils synthesize IL-8 in an IgE-mediated activation.

It has been demonstrated that neutrophils are responsible for the release of large amounts of the inflammatory chemokine interleukin-8 (IL-8), associated with inflammation. To further define the mechanisms implicated, we have analyzed the response of human neutrophils from allergic patients to specific antigens or challenge with anti-immunoglobulin (Ig)E antibodies. Neutrophils showed a dose- and time-dependent production of IL-8. The release of the cytokine was parallel to expression of IL-8 mRNA analyzed by the polymerase chain reaction. This expression was transient-it occurred after 3 h of anti-IgE treatment and was maintained for 18 h. Trifluoperazine, EGTA, reduced nicotinamide adenine dinucleotide phosphate-oxidase inhibitors, and reactive oxygen species (ROS) scavengers inhibited IL-8 production, indicating a critical dependence of calcium and oxidative stress. Moreover, an inhibitory effect of cyclosporin A, an immunosuppressor that inhibits calcineurin activity, on IL-8 release and IL-8 mRNA expression was observed. This is the first evidence of the involvement of ROS and calcium/calcineurin in IgE-dependent IL-8 production. These findings open new perspectives into the functional role of neutrophils in IgE-associated diseases.

A new role for monoamine oxidases in the modulation of macrophage-inducible nitric oxide synthase gene expression.

This report focuses on the modulatory role of endogenous H(2)O(2) on lipopolysaccharide (LPS)/interferon-gamma (IFN-gamma)-induced inducible nitric oxide synthase (NOS2) gene expression in rat peritoneal macrophages. Exogenously added H(2)O(2) was initially found to inhibit the synthesis of NOS2, which prompted us to assess the effect of the activity of monoamine oxidase (MAO) and semicarbazide-sensitive amine oxidase (SSAO) as H(2)O(2)-forming enzymes on NOS2 gene expression. In the presence of their substrates, tyramine for MAO and benzylamine for SSAO, intracellular synthesis of H(2)O(2) took place with concomitant inhibition of LPS/IFN-gamma-induced NOS2 protein synthesis, as detected by Western blotting, flow cytometry, and immunofluorescence microscopy analyses. Pargyline and semicarbazide, specific inhibitors of MAO and SSAO, respectively, canceled this negative effect of MAO substrates on NOS2 expression. In the presence of Fe(2+) and Cu(2+) ions, inhibition of NOS2 expression was enhanced, suggesting the participation in this regulation of species derived from Fenton chemistry. In addition, the negative effect of H(2)O(2), generated by MAOs, was found to be exerted on NOS2 mRNA levels. These data offer a new insight in the control of NOS2 expression through the intracellular levels of H(2)O(2) and other reactive oxygen species (ROS). The hypothesis can be raised that the inhibition of NOS by H(2)O(2) could constitute a protective mechanism against the cytotoxic consequences of the activation of ROS-generating enzymes, thus providing a new, singular role for the MAO family of proteins.

Oxidative stress is a critical mediator of the angiotensin II signal in human neutrophils: involvement of mitogen-activated protein kinase, calcineurin, and the transcription factor NF-kappaB.

Neutrophils are mobilized to the vascular wall during vessel inflammation. Published data are conflicting on phagocytic nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase activation during the hypertensive state, and the capacity of angiotensin II (Ang II) to modulate the intracellular redox status has not been analyzed in neutrophils. We here describe that Ang II highly stimulates endogenous and extracellular O2- production in these cells, consistent with the translocation to the cell membrane of the cytosolic components of NADPH oxidase, p47phox, and p67phox. The Ang II-dependent O2- production was suppressed by specific inhibitors of AT1 receptors, of the p38MAPK and ERK1/2 pathways, and of flavin oxidases. Furthermore, Ang II induced a robust phosphorylation of p38MAPK, ERK1/2, and JNK1/2 (particularly JNK2), which was hindered by inhibitors of NADPH oxidase, tyrosine kinases, and ROS scavengers. Ang II increased cytosolic Ca2+ levels-released mainly from calcium stores-enhanced the synthesis de novo and activity of calcineurin, and stimulated the DNA-binding activity of the transcription factor NF-kappaB in cultured human neutrophils. Present data demonstrate for the first time a stimulatory role of Ang II in the activation of phagocytic cells, underscore the relevant role of ROS as mediators in this process, and uncover a variety of signaling pathways by which Ang II operates in human neutrophils.

Activation of phagocytic cell NADPH oxidase by norfloxacin: a potential mechanism to explain its bactericidal action.

The mechanisms underlying the bactericidal power of fluoroquinolones against intracellular parasites in host macrophages remain poorly understood. We have analyzed the effect of norfloxacin, a fluoroquinolone antibiotic, on the production of reactive oxygen intermediates (O(2)(*-) and H(2)O(2)) and NADPH oxidase activity in mouse macrophages. The generation of anion superoxide (O(2)(*-)) was found to be significantly greater in macrophages incubated with norfloxacin than in untreated controls. This enhancing effect of norfloxacin was dose-dependent and reached maximal values within 10 min after its addition. The O(2)(*-) generated was mainly intracellular, as determined by the use of specific dyes, such as lucigenin and luminol, and able to diffuse freely through the cell membrane. Also, the production of H(2)O(2) was increased in macrophages in response to norfloxacin. The positive effect of norfloxacin was associated to an enhanced mobilization of NADPH oxidase subunits p47(phox) and p67(phox) from the cytosol to the plasma membrane in phagocytic cells. The effect of the antibiotic persisted in vivo for several hours. These data support the notion that norfloxacin inhibits mycobacterial growth within phagocytic cells by enhancing intracellular production of O(2)(*-) and other reactive oxygen species.

Diverticulitis del ciego: reporte de un caso / Cecal diverticulitis: case report

Se presenta el caso de un paciente femenino que presentó cuadro de abdomen agudo que sugería apendicitisaguda en quien se encontró transoperatoriamente una masa del ciego, que se diagnóstico como adenocarcinoma de ciego y se realizó hemicolectomía derecha, sinembargo el estudio macroscópico demostró un divertículo de ciego inflamado y obstruido por fecalito, el estudio microscópico fue concluyente con diverculitis de ciego. Se hace una revisión de la incidencia dela patología, su diagnóstico diferencial y tratamiento

Liposarcoma mixoide retroperitoneal (reporte de un caso) / Retroperitoneal liposarcoma mixoid (case reported)

Se reporta el caso de un hombre de 43 años de edad, a quien se le intervino quirúrgicamente por crecimiento tumoral abdominal progresivo de 19 meses de evolución, asociado a emaciación y edema de partes blandas declives. La tomografía identificó una masa compatible con liposarcoma. La exploraciónquirúrgica confirmó el hallazgo y se extirpó parcialmente un tumor graso multilobulado retroperitoneal de 53 cms. en su diámetro mayor y con un peso de 57 lbs. El diagnóstico histológico fue liposarcoma tipo mixoide de bajo grado de malignidad. El enfermo sobrevivió 27 días con un postoperatorio complicado, ascitis persiste y pérdida de proteína por esta vía

Técnica quirúrgica de reforzamiento corneal para el queratocono (RCQ) / Surgical technique of corneal reinforcement for keratoconus

Desde enero de 1989 hasta diciembre de 1992 en el Hospital Docente Clinicoquirúrgico "Salvador Allende" y en el Hospital Pediátrico del Cerro se realizó un tratamiento quirúrgico de reforzamiento corneal para el queratocono, sin trasplante corneal. Se intervinieron 600 ojos a los cuales se les hizo un estudio oftalmológico completo preoperatorio. Se demostró una mejoría del grado de visión de todos los pacientes en dependencia de la visión preoperatoriacon una excelente tolerancia a la lentes de contacto, incluso en aquéllos que no lo toleraban. Este proceder constituye una alternativa en la terapéutica quirúrgica, preferentemente en los estadios incipientes, para evitar graves daños corneales y permite retrasar e inclusive eludir el trasplante corneal en el queratocono (AU)