Desigualdad e inequidad en la utilización de servicios médicos según grupos etarios en Chile, 2000-2011 / Inequality and inequity in the use of medical services in Chile, by age group, 2000-2011

OBJETIVO: Calcular los índices de desigualdad e inequidad en la utilización de servicios médicos para menores, adultos y adultos mayores en Chile entre 2000 y 2011 MÉTODOS: Se utiliza la encuesta CASEN (2000-2011) y se calculan el índice de concentración (IC) para medir la desigualdad y el índice de inequidad horizontal (IIH) para medir inequidad en la utilización de servicios médicos. Los grupos de análisis son cuatro: menores de 5 años, menores entre 6 y 18 años, adultos y adultos mayores RESULTADOS: Los resultados indican que la utilización de servicios de médicos especialistas presenta mayor nivel de desigualdad en los grupos de menores de edad y mayor nivel de inequidad en el grupo de adultos. En la utilización de servicios de atención dental, es el grupo de adultos mayores el de mayor desigualdad e inequidad. Las visitas a servicios de urgencias en los dos últimos años de los cuales se tienen datos (2009 y 2011), presentan mayor nivel de desigualdad en el grupo de adultos CONCLUSIONES: Existen diferencias en los niveles de inequidad y desigualdad entre menores, adultos y adultos mayores a través de los años al menos en tres de las seis variables en estudio.

OBJECTIVE: To calculate indices of inequality and inequity in the use of medical services for children, adults, and older adults in Chile from 2000 to 2011 METHODS: Based on the CASEN survey (2000-2011), the concentration index (CI) was calculated to measure inequality and the horizontal inequity index (HI) was calculated to measure inequity in the use of medical services. Four groups were studied: children under 5, children aged 6-18 years, adults, and older adults RESULTS: The results indicate higher levels of inequality in the use of specialized physician services in the child groups, and higher levels of inequity in the adult group. In the use of dental services, the greatest inequality and inequity is found among older adults. For visits to emergency services in the last two years for which data are available (2009 and 2011), the adult group shows a higher level of inequality CONCUSIONS: In terms of levels of inequity and inequality, there are differences among children, adults, and older adults over the years in at least three of the six variables studied.

Prevalencia de síndrome de Gilbert y sus determinantes genéticas en población chilena / Prevalence of Gilbert syndrome and its genetic determinants in Chile

Background: In Europeans the TATA box TA7 repeat promoter variant in the UGT1A1 gene (UGT1A1*28) is the major determinant of bilirubin levels. Aim: To study the prevalence of Gilbert Syndrome (GS) and its genetic determinants in Chile. Material and Methods: Three different studies were conducted. The prevalence of GS in Chile was assessed in 991 subjects with normal liver tests (ALT and GGT) from the 2nd National Health Survey. We defined GS as a total bilirubin (TB) between 1.4-5mg/dL. The second study assessed the genotype prevalence of SNP rs6742078 (in LD with UGT1A1*28) and rs4149056 in 500 DNA samples of non-related Hispanics. Finally, a case-control study was designed to assess the phenotype-genotype correlation. UGT1A1*28 and rs4149056 variants were determined by direct sequencing and allelic discrimination assays (TaqMan), respectively. Results: Prevalence of GS in the general Chilean population was 2.6% (4.5% in males and 0.5% in female). No correlation with age, educational level or home location was found. Genotypes for UGT1A1*28 (TA6/6 50.5%, TA6/7 37.8%, TA7/7 11.7%) and rs4149056 (TT 74.1%, CT 22.8%, and CC 3.1%) variants were similar to Europeans. In the case-control study, most patients with GS were homozygotes for UGT1A1*28 (TA7/7, 74%). Of note, 44% of patients with intermediate TB levels were also TA7/7, compared to 7% in normal subjects. SLCO1B1 genotype was not correlated with TB levels. Conclusions: While the prevalence of GS was lower in Chile compared to Europeans (~5%), the prevalence of UGT1A1*28 homozygotes was similar (~12%). In Chilean Hispanics, the UGT1A1*28 variant explain 75% of GS phenotype.

Principales factores de virulencia de Listeria monocytogenesy su regulación / Main virulence factors of Listeria monocytogenesand its regulation

Listeria monocytogenesis a facultative intracellular pathogen, ubiquitous and aetiological agent of listeriosis. The main way of acquisition is the consumption of contaminated food and can cause serious medical conditions such as septicemia, meningitis and gastroenteritis, especially in children, immunocompromised individuals and seniors and abortions in pregnant women. An increase in cases of listeriosis worldwide has been reported and it is estimated that its prevalence in developed countries is in the range of 2 to 15 cases per one million population. This microorganism is characterized for the transition from the environment into the eukaryotic cell. Several virulence factors have been involved in the intracellular cycle that are regulated, pimarilly, by the PrfA protein, which in turn is regulated by different mechanisms operating at the transcriptional, translational and post-translational levels. Additionally, other regulatory mechanisms have been described as sigma factor, system VirR/S and antisense RNA, but PrfA is the most important control mechanism and is required for the expression of essential virulence factors for the intracellular cycle.

Listeria monocytogeneses un patógeno intracelular facultativo, ubicuo y agente etiológico de listeriosis. La principal vía de adquisición es el consumo de alimentos contaminados, pudiendo ocasionar cuadros clínicos muy graves como septicemia, meningitis y gastroenteritis, especialmente en niños, individuos inmunocomprometidos y de la tercera edad, y aborto en mujeres embarazadas. Se ha informado un aumento en los casos de listeriosis a escala mundial y se estima que su frecuencia en los países desarrollados está en un rango de 2 a 15 casos por millón de habitantes. Este microorganismo se caracteriza por realizar una transición desde el medio ambiente hacia la célula eucariota. Para este proceso se han descrito varios factores de virulencia, los cuales están involucrados en el ciclo intracelular y están regulados, principalmente, por la proteína PrfA, la cual a su vez está regulada por diferentes mecanismos que actúan a nivel transcripcional, traduccional y post-traduccional. Además, se han descrito otros mecanismos regulatorios como: factor Sigma, sistema VirR/S y ARN sin sentido. No obstante, PrfA es el mecanismo de control más importante y el cual es requerido para la expresión de los factores de virulencia esenciales para el ciclo intracelular.

HLA-B*5701 frequency in Chilean HIV-infected patients and in general population

It has been demonstrated that HLA-B*5701 screening reduces the risk for hypersensitivity reaction to abacavir in HIV-infected patients. Since B*5701 prevalence varies among different populations, it is important to determine the carrier frequency prior to its use for the screening of HIV-infected patients.The aim of this study was to determine HLA-B*5701 carrier frequency in Chilean general population and HIV-infected patients referred for B*5701 typing. For that purpose 300 blood bank donors and 492 abacavir-naïve HIV-infected patients from Chile were screened for B*5701 by a sequence specific primer PCR.We detected 14/300 (4.7 percent) B*57-positive individuals in the Chilean general population, 11 (3.7 percent) were B*5701 positive, and 3 (1 percent) had another subtype.All were heterozygous,thus a B*5701 allele frequency of 2 percent was determined.Eleven of 492 (2.2 percent) HIV-patients carried a B*5701 allele. The difference between these frequencies is probably due to slow progression of HIV infection in HLA-B*5701 carriers, thus less patients would require antiretroviral therapy and B*5701 typing. Considering the usefulness of B*5701 screening, its prevalence in the Chilean general population,and the availability of a validated method,we conclude that HLA-B*5701 typing in Chilean HIV-infected patients about to initiate abacavir treatment is strongly recommended.

Cianobacterias y riesgos potenciales de toxicidad en aguas continentales de Chile / Cyanobacteria and potential risks of toxicity in continental waters of Chile

Las cianobacterias son microorganismos fototróficos oxigénicos, con una amplia distribución, ya que han sido reportados en aguas dulces o saladas de los cinco continentes. Eventualmente pueden desarrollarse en grandes masas, denominadas ®blooms (florecimientos), generados, usualmente, por efectos antropogénicos. Varias especies de cianobacterias pueden producir potentes neurotoxinas y hepatotoxinas, las cuales presentan serias dificultades para ser eliminadas del agua. La intoxicación con algunas de estas toxinas puede ser grave causando la muerte de animales o el hombre y se sospecha que la ingestión aún de microdosis, pueda inducir la formación de tumores. La distribución de cianobacterias de aguas continentales de Chile, se presenta desde el extremo Norte hasta el territorio Antártico. Se ha determinado en diferentes regiones la presencia de especies tóxicas y la formación de florecimientos. Mediante cromatografía líquida de alta presión (HPLC) y espectrometría de masas (MALDITOF) (PSD), se ha determinado en diferentes cuerpos de agua la cianotoxina microcistina. Finalmente se sugieren recomendaciones para tomar conocimiento y establecer controles que eviten el riesgo a su exposición.

Cyanobacteria are phototropic and oxygenic microorganisms that are widely distributed and reported to be present in freshwater or seawater from the five continents. They can eventually develop into large masses called ®blooms¼ which are usually generated by anthropogenic effects. Several species of cyanobacteriacan produce potent neurotoxins and hepatotoxins, which are difficult to eliminate from water. The intoxicationwith some of these toxins can become severe causing death in animals and man and it is suspected that ingestion of even microdoses of them can induce tumor appearance. The distribution of cyanobacteria in continental waters of Chile has been recorded from uppermost north of Chile up to the Antarctic territory. The presence of toxic species as well as the development of blooms have been detected in different regions.The mycrocystin cyanotoxin has been assessed in different masses of water by means of high pressure liquidchromatography (HPLC) together with mass spectrometry (MALDI-TOF) (PSD). Finally it is recommended to make analysis in order to establish controls that avoid risk of exposure to these cyanotoxins.

Valor de la resonancia magnética en la patología mamaria de sospecha oncológica / MRI in suspicious breast lesions

Propósito. Valorar la RM en la detección y manejo de la patología oncológica. La multifocalidad y la multicentricidad de las lesiones. Material y métodos. Estudiamos por RM 18 pacientes con lesiones palpables y no palpables detectadas por otros métodos, así como cambios mamarios postquirúrgicos (n=4). Se utilizaron secuencias T1 antes y después de la inyección de gadolinio, secuencias ponderadas en T2 y técnicas de sustracción digital. Resultados. De los 18 pacientes estudiados, 9 (50 por ciento) tenían lesiones palpables, 5 (28 por ciento) presentaban lesiones no palpables (infraclínicas) y 4 (22 por ciento) cambios postquirúrgicos. Los hallazgos imagenológicos fueron confirmados mediante biopsias estereotáxicas y quirúrgicas en 16 pacientes, las dos restantes se encuentran bajo seguimiento. Seis pacientes con lesiones palpables (33 por ciento) presentaron concordancia con los hallazgos anatomo-radiológicos. En dos pacientes con reforzamiento post gadolinio en la RM la anatomía patológica mostró cáncer en una...