Cross-evaluation of metrics to estimate the significance of creative works.

In a world overflowing with creative works, it is useful to be able to filter out the unimportant works so that the significant ones can be identified and thereby absorbed. An automated method could provide an objective approach for evaluating the significance of works on a universal scale. However, there have been few attempts at creating such a measure, and there are few "ground truths" for validating the effectiveness of potential metrics for significance. For movies, the US Library of Congress's National Film Registry (NFR) contains American films that are "culturally, historically, or aesthetically significant" as chosen through a careful evaluation and deliberation process. By analyzing a network of citations between 15,425 United States-produced films procured from the Internet Movie Database (IMDb), we obtain several automated metrics for significance. The best of these metrics is able to indicate a film's presence in the NFR at least as well or better than metrics based on aggregated expert opinions or large population surveys. Importantly, automated metrics can easily be applied to older films for which no other rating may be available. Our results may have implications for the evaluation of other creative works such as scientific research.

[The Latin-American Consensus on Chronic Constipation]. / Consenso Latinoamericano de Estreñimiento Crónico.

The Latin-American Consensus on Chronic Constipation aimed to establish guidelines to improve the identification, diagnosis and treatment of this disorder in the region. Two coordinators and an honorary coordinator established the process and the topics to be discussed, based on a systematic review of the literature published in the previous 10 years, since 1995. Seventeen members participated with the support of their local gastroenterology societies. The members reviewed the different subjects based on the levels of evidence and grades of recommendation; the topics were then discussed in a plenary session. A written report was drafted and the coordinators prepared the final declarations to be submitted to a vote by all the members in October 2006. The consensus concluded that chronic constipation has an estimated prevalence of 5-21% in the region, with a female-to-male ratio of 3:1. Among individuals with constipation, 75% use some type of medication, with more than 50% using home remedies. A diagnosis based on Rome Criteria was recommended and diagnostic testing only in persons older than 50 years or with alarm symptoms. The use of barium enema as an initial investigation was recommended only in countries with a high prevalence of idiopathic megacolon or Chagas' disease. Recommendations on treatment included an increase in dietary fiber of up to 25-30 g/day (grade C). No evidence was found to recommend measures such as exercise, increased water intake, or frequent visits to the toilet. Fiber supplements such as Psyllium received a grade B and pharmacological treatments such as tegaserod and polyethylene glycol, both grade A. There was insufficient evidence to recommend lactulose, but the consensus did not disadvise its use when necessary. Complementary investigations such as colonic transit followed by anorectal manometry and defecography were only recommended to rule out colonic inertia and/or obstructive defecation in patients not responding to treatment. Biofeedback was recommended (grade B) for those with pelvic dyssynergia.

A hydrogel-based microfluidic device for the studies of directed cell migration.

We have developed a hydrogel-based microfluidic device that is capable of generating a steady and long term linear chemical concentration gradient with no through flow in a microfluidic channel. Using this device, we successfully monitored the chemotactic responses of wildtype Escherichia coli (suspension cells) to alpha-methyl-DL-aspartate (attractant) and differentiated HL-60 cells (a human neutrophil-like cell line that is adherent) to formyl-Met-Leu-Phe (f-MLP, attractant). This device advances the current state of the art in microchemotaxis devices in that (1) it demonstrates the validity of using hydrogels as the building material for a microchemotaxis device; (2) it demonstrates the potential of the hydrogel based microfluidic device in biological experiments since most of the proteins and nutrients essential for cell survival are readily diffusible in hydrogel; (3) it is capable of applying chemical stimuli independently of mechanical stimuli; (4) it is straightforward to make, and requires very basic tools that are commonly available in biological labs. This device will also be useful in controlling the chemical and mechanical environment during the formation of tissue engineered constructs.

[Post-infectious irritable bowel syndrome. A review based on current evidence]. / Síndrome de intestino irritable postinfeccioso. Una revisión basada en evidencias.

INTRODUCTION: Pathophysiology of irritable bowel syndrome (IBS) is multifactorial. Recent investigations have associated episodes of infectious gastroenteritis with development of IBS. This condition is named post-infectious IBS (PI-IBS). The role of inflammation-infection in IBS pathogenesis is not well understood. AIM: To review published scientific evidence on PI-IBS regarding risk factors, causal agents, histopathological changes, and treatment. MATERIALS AND METHODS: An electronic search in MEDLINE and abstracts presented at national and international GI meetings was performed, looking for information published in the past 50 years including animal studies, cohort studies, case-control studies, and series of cases and case reports, using the key words post-infectious enteritis, post-dysenteric or post-infectious irritable bowel syndrome (PI-IBS), and post-infectious colitis. RESULTS: Fifty one papers were included. These studies were classified according to pathophysiologic mechanisms, infectious agents involved, animal or human studies, and treatment. CONCLUSIONS: Current evidence shows a strong association between colonic infection and inflammation with development of IBS. Approximately 25% of patients with IBS have a history of infectious enteritis. Microbial agents related with PI-IBS include bacteria (Campylobacter, Salmonella) and parasites (Trichinella spiralis). Increased number of enteroendocrine cells, CD3 lymphocytes and mast cells within the colonic muscle wall, release of pro-inflammatory substances, and increased number of inflammatory cells with intestinal nervous endings are the most common histopathologic findings. Patients developing PI-IBS have a higher frequency of psychological disorders and stressful events prior to the gastroenteritis episode. Therapeutic interventions with steroids, COX-2 inhibitors, antibiotics and probiotics require further investigation.

Utilización de recursos médicos por los pacientes con síndrome de intestino irritable en un hospital de tercer nivel / Utilization of medical resources for patients with irritable bowel syndrome in a third level hospital

Antecedentes: El síndrome de intestino irritable (SII) es un trastorno que produce un alto costo a la sociedad en términos de ausentismo, consultas, exámenes médicos, tratamientos y cirugías innecesarias. Objetivo: Conocer la utilización de recursos médicos por pacientes con SII en un hospital de referencia. Método. Estudio retrospectivo de expedientes de pacientes con SII. Se analizó el número de estudios de laboratorio, gabinete y consultas médicas y número de cirugías abdominales. Resultados: Entre 1987-1996 se identificaron 98 pacientes con edad promedio 40.8 años. El seguimiento fue de 33.4 meses (rango: 1-243) durante los cuales se solicitaron en promedio 22.4 estudios por pacientes (rango: 1.82). Se requirieron 5.0 estudios por paciente (rango: 1-11) previos al diagnóstico de SII. En el 87 por ciento de los pacientes, el diagnóstico de SII se estableció durante la primera consulta. Cada paciente consultó 3.6 veces/año, 44.2 por ciento por síntomas gastrointestinales y 48.6 por ciento por síntomas no gastrointestinales. Las consultas con mayor demanda fueron medicina interna (53.0 por ciento), gastroenterología (38.8 por ciento), proctología (31.6 por ciento), psiquiatría (21.4 por ciento), ginecología (18.4 por ciento) urología (13.3 por ciento). El 17.3 por ciento tenía antecedentes de apendicectomías y 13.3 por ciento colecistectomías. El 1.02 por ciento y el 2.04 por ciento respectivamente fueron practicadas luego del diagnóstico de SII. Conclusiones: A pesar de los reconocidos criterios diagnósticos de Roma, se solicitan numerosos estudios de laboratorio y gabinete para descartar enfermedad orgánica a los pacientes con SII, y estos demandan un elevado promedio de consultas médicas anuales. Además, los pacientes con SII tienen una elevada tasa de apendicectomías y colecistectomías

Caso de úlcera aislada de yeyuno y revisión de la literatura / A case of solitary yeyunal ulcer and review of the literature

Presentamos el caso de una paciente con antecedentes de artris reumatoide y uso crónico de antiinflamatorios no esteroideos que presentó una úlcera aislada de yeyuno con estenosis perilesional. Clínicamente se manifestó con obstrucción intestinal intermitente y el diagnóstico se realizó durante la laparotomía exploradora. Se revisa la literatura y se enfatiza la importancia del diagnóstico, especialmente el radiológico

Diagnóstico endoscópico del carcinoma gástrico en el Hospital San Ignacio / Gastric cancer: endoscopic diagnosis in the Hospital San Ignacio

Colombia ocupa el tercer lugar del mundo en cáncer gástrico con más de dos mil casos nuevos por año. La endoscopia de vías digestivas altas se considera una de las armas más importantes en el diagnóstico de cáncer gástrico. Objetivos : Determinar la precisión diagnóstica de cáncer gástrico por visualización endoscópica, número ideal de muestras (biopsia endoscópica). Diseño : Estudio Descriptivo retrospectivo de una serie de casos. Resultados : Entre 1982-1992 se realizaron 179 endoscopias en 160 pacientes con cáncer gástrico, al 11.2/100 se les repitió la endoscopia. En el 86.9/100 el diagnóstico histológico confirmó con la primera endoscopia, el 8.1/100 requirió 2 endoscopias y sólo 1, tres endoscopias. El diagnóstico endoscópico fue correcto en el 97.2/100 de las endoscopias contra un 83.8/100 de diagnósticos histológicos correctos diferencia estadísticamente significativa. Se tomaron un promedio de 5 fragmentos por endoscopia tanto en los informados como carcinoma como en los que no. La localización del tumor no tuvo relación con el diagnóstico endoscópico ni el número de endoscopias necesarias. Conclusión : La endoscopia de vías digestivas altas en el hospital San Ignacio constituye un método de alta precisión en el diagnóstico de cáncer gástrico.

Tamizaje para enfermedad hepática alcohólica en comunidades indígenas colombianas / Screening for hepatic alcoholic disease in natives comunities in Colombia

Diseño : estudio descriptivo con casos y controles anidado. Resultados : estudiamos 176 indígenas de 12 comunidades diferentes en edad media de 32.5 años. El 76.7/100 consumen bebidas alcohólicas o fermentadas, 94.2/100 de los hombres y 60/100 de las mujeres. La edad de inicio de consumo varía pero con una mayor tendencia a iniciar a los 15 años. Conclusión : el 31.8/100 de los indígenas que consumen bebidas alcohólicas o fermentadas tienen aparente daño hepático por tamizaje, por lo cual deben ser investigadas más profundamente. Los hombres consumen más que las mujeres pero éstas tienen mayores niveles de GGTP. La GGTP no se relaciona con el tipo de bebida pero sí con los años de consumo. Proponemos una escala diferente de normalidad para la GGTP en comuniddes indígenas de Colombia.