[Comparative prevalence of adenomatous polyps in people aged 45 to 49 years and in people over 50 years of age in a Colombian population: a case-control study]. / Prevalencia comparativa de pólipos adenomatosos en personas de 45 a 49años y en mayores de 50 años en una población colombiana: estudio de casos y controles.

INTRODUCTION: Colon and rectal cancer (CRC) is the third most frequent cancer and the fourth cause of cancer death in the world. In Colombia, it is the third leading cause of death from cancer. The most accepted recommendation is to do colonoscopy screening in people 50 to 75 years old. However, recently the American Cancer Association (ACS) has recommended starting screening from the age of 45. In our environment there are no studies on the prevalence of adenomatous polyps in children under 50 years of age. OBJECTIVE: To compare the prevalence of adenomatous polyps during screening colonoscopy in people aged 45-49 years (cases) and compare it with that of people aged 50 to 75 years (control). MATERIALS AND METHODS: Case-control studies. The data were collected prospectively during the period from January 2018 to November 2019 at the gastroenterology and digestive endoscopy center of Bogotá Colombia. RESULTS: 490 patients were included, 119 cases and 371 controls, case: control ratio was 1: 3. The prevalence of polyps in cases 36.7% and in controls (42.5%) p=0.279. Adenomatous polyps were detected in 18.5% (95% CI 12.4-26.6) of the cases and 32.4% (95% CI 27.7-37.2) of the controls (p=0.004). CONCLUSION: The prevalence of polyps during screening colonoscopy in people aged 45-49 years is similar to that expected in screening colonoscopies of people between 50-75 years. This finding would favor screening colonoscopy from 45 years of age.

[Helicobacter pylori, nodular gastritis and premalignant stomach lesions: a case-control study]. / Helicobacter pylori, gastritis nodular y lesiones premalignas de estómago: un estudio de casos y controles.

INTRODUCTION: Nodular gastritis (GN) is a type of gastritis strongly related to Helicobacter pylori and may be a risk factor for gastric cancer. It is a highly prevalent pathology in children infected with H. pylori. In Colombia there are no studies on this entity and for this reason we decided to carry out the present investigation. MATERIALS AND METHODS: Case studies and controls. Case; endoscopic and histological nodular gastritis, controls, chronic gastritis without lymphoid follicles to histology. POPULATION: adults older than 18 years, who underwent a high digestive endoscopy and signed informed consent. All patients were biopsied with the OLGA system. RESULTS: We included 344 patients, 172 in each group. The cases had 10 years less than the controls (40.9 vs 50.9, p = 0.045). In the cases H. pylori was found in 91.9% vs 47.8% (p <0.001). Lymphoid follicles were more frequent in the antrum than in the body (60.5 vs 4.7% p < 0.00001). OLGA II in cases 6.4% versus 1.2% (p = 0.01), OLGA III was similar. There was no OLGA IV in any patient. In the cases a gastric cancer was found. CONCLUSIONS: Patients with nodular gastritis are younger than controls. 92% of the cases had H. pylori. RECOMMENDATIONS: It is recommended that this infection be investigated and eradicated in patients with this type of gastritis.

The problem of Helicobacter pylori resistance to antibiotics: a systematic review in Latin America.

OBJECTIVES: Latin America has a high prevalence of Helicobacter pylori infection and associated diseases, including gastric cancer. Antibiotic therapy can eradicate the bacterial infection and decrease associated morbidity and mortality. To tailor recommendations for optimal treatments, we summarized published literature and calculated region- and country-specific prevalences of antibiotic resistance. METHODS: Searches of PubMed and regional databases for observational studies evaluating H. pylori antibiotic resistance yielded a total of 59 independent studies (56 in adults, 2 in children, and 1 in both groups) published up to October 2013 regarding H. pylori isolates collected between 1988 and 2011. Study-specific prevalences of primary resistance to commonly prescribed antibiotics were summarized using random-effects models. Between-study heterogeneity was assessed by meta-regression. As a sensitivity analysis, we extended our research to studies of patients with prior H. pylori-eradication therapy. RESULTS: Summary prevalences of antimicrobial primary resistance among adults varied by antibiotic, including 12% for clarithromycin (n=35 studies), 53% for metronidazole (n=34), 4% for amoxicillin (n=28), 6% for tetracycline (n=20), 3% for furazolidone (n=6), 15% for fluoroquinolones (n=5), and 8% for dual clarithromycin and metronidazole (n=10). Resistance prevalence varied significantly by country, but not by year of sample collection. Analyses including studies of patients with prior therapy yielded similar estimates. Pediatric reports were too few to be summarized by meta-analysis. CONCLUSIONS: Resistance to first-line anti-H. pylori antibiotics is high in Latin American populations. In some countries, the empirical use of clarithromycin without susceptibility testing may not be appropriate. These findings stress the need for appropriate surveillance programs, improved antimicrobial regulations, and increased public awareness.

Impact of access to treatment on patient-reported outcomes among rheumatoid arthritis patients with tDMARDs and bDMARDS in two Latin-American countries: A prospective observational study.

Background and Aims: A noninterventional prospective study was performed in Colombia and Peru. The aim was to describe the impact of access to treatment on Patient-reported outcomes (PRO) in patients with Rheumatoid arthritis (RA) after failure to conventional disease-modifying antirheumatic drugs (DMARDs) in real-life conditions. Methods: The impact of access to treatment was measured by access barriers, time to supply (TtS) and interruption evaluating their effect in changes of PROs between baseline and 6-month follow-up between February 2017 and November 2019. The association of access to care with disease activity, functional status, health-related quality of life was assessed using bivariate and multivariable analysis. Results are expressed in least mean difference; TtS in mean number of days for delivery of treatment at baseline. Variability measures were standard deviation and standard error. Results: One hundred seventy patients were recruited, 70 treated with tofacitinib and 100 with biological DMARDs. Thirty-nine patients reported access barriers. The mean of TtS was 23 ± 38.83 days. The difference from baseline to 6-month visit in PROs were affected by access barriers and interruptions. There was not statistically significant difference in the of PRO's score among visits in patients that reported delay of supply of more than 23 days compared to patients with less days of delay. Conclusion: This study suggested the access to treatment can affect the response to the treatment at 6 months of follow-up. There seems to be no effect in the PROs for delay of TtS during the studied period.

Prevalence of cagA, vacA, babA2 and iceA genes in H. pylori strains isolated from Colombian patients with functional dyspepsia.

The clinical outcome of Helicobacter pylori infection has been particularly associated with virulence genotypes. These genotypes are useful as molecular markers in the identification of patients that are infected and at high risk for developing more severe gastric pathologies. Our main objective was to determine the prevalence of virulence genotypes cagA, vacA, iceA and babA2 of H. pylori, in patients with functional dyspepsia who are infected with the bacteria. H. pylori genotypes babA2 and cagA as well as vacA and iceA allelic variants were identified by PCR in 122 isolates resulting from 79 patients with functional dyspepsia. A high prevalence of genes cagA+ (71%), vacAs1am1 (34%), babA2 (57%) and iceA1 (87%) was found. The most frequent combined genotype found were cagA+/vacAs1am1/babA2+/iceA1 and cagA-/vacAs1am1/babA2+/iceA1, regardless of any family history of gastric cancer or MALT lymphoma. The very virulent genotype cagA+/vacAs1am1/babA2+/iceA1 prevailed in the studied patients with functional dyspepsia. Our results provide information about the prevalence of four of the more important virulent factors and constitute new evidence on the prevalence of the most virulent H. pylori genotype in patients with functional dyspepsia.

Long-term effect of a simple nest-box on the reproductive efficiency and other life traits of an Aotus lemurinus lemurinus monkey colony: an animal model for malaria research.

BACKGROUND: The long-term effect of a PVC pipe nest-box on the reproductive efficiency and other life traits of an Aotus monkey-breeding colony have not been characterized. METHODS AND RESULTS: We analyzed laboratory records of the Gorgas Memorial Institute (GMI) Aotus monkey colony in Panama for the period 1999-2010 and found a 273% increase in the annual mean life births in the following 7 years after the introduction of a PVC pipe nest-box in 2002, as well as increases in the mean body mass and survival of laboratory-bred monkeys. Other life traits such as inter-birth interval, parity, birth sex distribution, mortality, and longevity were also determined. CONCLUSIONS: The use of a PVC pipe nest-box significantly improved the reproductive efficiency and other life traits of the GMI Aotus breeding colony.

Development of a Psychosocial Intervention to Promote Treatment Adherence in Patients with Bipolar Disorder at Risk of Cardiovascular Disease.

Nonadherence to treatment is a serious concern that affects the successful management of bipolar disorder (BD) patients. The aim of this study was to pilot test a psychosocial intervention (previously developed by this team) intended to increase adherence to medication and health behaviors targeting cardiovascular disease (CVD) risk factors in BD patients. An open, single-group design was used to assess the feasibility and acceptability of the intervention. The participants had BD, type I/II or unspecified, and CVD risk factors. Baseline demographic measures were taken. We also obtained preliminary effect sizes related to pre-post changes on measures of self-reported adherence to psychiatric medication, depressive and manic symptoms, and pharmacy records. At baseline, 29% of the participants reported recent adherence to psychiatric medications. A total of 71% of the participants completed the intervention. Pre-post improvements by medium and large effect sizes (Cohen's d = 0.52-0.92) were seen in medication adherence, attitudes toward medication, and mania symptoms. The participants reported high levels of satisfaction with the intervention. A culturally sensitive psychosocial intervention for Puerto Rican BD patients who are at risk of CVD was found to be feasible and acceptable. Improvements in the key outcomes were seen in this small, preliminary study. Further research is needed with a larger sample size.

Helicobacter pylori: Multiple resistance in patients from Bogotá, Colombia / Helicobacter pylori: resistencia múltiple en pacientes de Bogotá, Colombia

Introduction: The main cause for Helicobacter pylori infection treatment failure is antibiotic resistance, where clarithromycin and metronidazole play the main role. In Colombia, primary resistance as a consequence of the use of these two antibiotics and excessive levofloxacin use is above the accepted limit (13.6%, 83%, and 16%, respectively). Despite this fact, empirical therapies that include the combination of these antibiotics are used in patients with previous therapeutic failure. Objective: To determine antibiotic resistance in patients previously treated for H. pylori in Bogotá, Colombia. Materials and methods: We conducted a descriptive study that included ten isolates obtained from five patients with three or four previous failed treatments for H. pylori. Antibiotic resistance to amoxicillin, clarithromycin, levofloxacin, and metronidazole was investigated by agar dilution and confirmed by DNA sequencing (Magrogen, Korea). Results: Eight isolates were resistant to two or more antibiotics. All isolates were resistant to levofloxacin. Susceptibility patterns in isolates from the gastric antrum and the body of the stomach were different in three patients. Conclusion: As far as we know, this is the first evidence of multiple H. pylori resistance in Colombia in previously treated patients. Results demonstrated the consequences of using an ineffective antibiotic scheme and the need to assess antibiotic susceptibility in different anatomical sites of the stomach. The consequences of multiple resistance decrease possible antibiotic effectiveness to eradicate H. pylori in the future.

Introducción. La resistencia a los antibióticos es la principal causa del fracaso del tratamiento contra Helicobacter pylori; la claritromicina y el metronidazol son los antibióticos que generan mayor resistencia. En Colombia, la resistencia primaria a estos dos antibióticos y el uso excesivo de levofloxacina han alcanzado los límites aceptados (13,6, 83 y 16 %, respectivamente). A pesar de ello, se usa el tratamiento empírico combinando estos antibióticos en pacientes en los que ha fallado anteriormente. Objetivo. Determinar la resistencia a los antibióticos en pacientes previamente tratados para H. pylori en Bogotá, Colombia. Materiales y métodos. Se llevó a cabo un estudio descriptivo en el que se evaluó mediante dilución en agar la resistencia a la amoxicilina, la claritromicina, la levofloxacina y el metronidazol en 10 aislamientos provenientes de 5 pacientes con tres o cuatro tratamientos fallidos para H. pylori. La resistencia a los antibióticos se confirmó mediante secuenciación de ADN (Magrogen, Korea). Resultados. Ocho de los aislamientos presentaron resistencia a dos o más antibióticos y todos fueron resistentes a la levofloxacina. Los patrones de sensibilidad de los aislamientos provenientes del antro pilórico y del cuerpo del estómago, fueron diferentes en tres de los pacientes. Conclusión. Hasta donde se sabe, esta es la primera evidencia de resistencia múltiple de H. pylori en Colombia en pacientes previamente tratados. Los resultados evidenciaron las consecuencias del uso de un esquema ineficaz de tratamiento antibiótico y la necesidad de evaluar la sensibilidad a los antibióticos en diferentes sitios anatómicos del estómago. La resistencia múltiple limita el número de antibióticos útiles para erradicar H. pylori.

Tuberculosis (TB) outbreak in a closed Aotus monkey breeding colony: Epidemiology, diagnosis and TB screening using antibody and interferon-gamma release testing.

Tuberculosis (TB) caused by Mycobacterium tuberculosis (MTB) is a devastating and terminal disease in non-human primates (NHPs). Regular TB screenings using the intradermal tuberculin test (TST) have been the mainstay of TB surveillance and control in NHPs. Historically, Aotus monkeys have been considered less susceptible to TB than other NHPs. Here we present the diagnosis and epidemiology of a TB outbreak at The Gorgas Memorial Institute Aotus colony in Panama, and the results of two cross-sectional randomized TB screening studies, using antibody (Ab) and IFN-gamma release assay testing. RESULTS: Epidemiological and spatial analysis confirmed that the outbreak was the result of a continuing intermittent exposure, with human to monkey transmission as the most likely source. During the outbreak that lasted five months (January-June 2015), Mycobacterium kansassi and MTB were isolated from lung caseous granulomas in 1/7 and 3/7 TB suspicious animals respectively. Furthermore, MTB was detected by qRT-PCR in formalin fixed lung and liver granulomas in 2/7 and 1/6 monkeys respectively, suggesting an aerosol route of infection. Likewise, a random sample that included 63 / 313 adult (>2 year-old) monkeys, screened for latent TB with the Primagam® IFN-gamma release assay, between March-May, 2016, were all non-reactors; indicating that the outbreak was self-limiting and the colony was likely free or latent TB infection. Control measures included, quarantine, disinfection and TST screening of all personnel. In conclusion, this study demonstrates that Aotus are highly susceptible to TB, therefore, TB prevention measures should be strictly enforced in Aotus monkey colonies.

Bone Marrow Is a Major Parasite Reservoir in Plasmodium vivax Infection.

Plasmodium vivax causes heavy burdens of disease across malarious regions worldwide. Mature P. vivax asexual and transmissive gametocyte stages occur in the blood circulation, and it is often assumed that accumulation/sequestration in tissues is not an important phase in their development. Here, we present a systematic study of P. vivax stage distributions in infected tissues of nonhuman primate (NHP) malaria models as well as in blood from human infections. In a comparative analysis of the transcriptomes of P. vivax and Plasmodium falciparum blood-stage parasites, we found a conserved cascade of stage-specific gene expression despite the greatly different gametocyte maturity times of these two species. Using this knowledge, we validated a set of conserved asexual- and gametocyte-stage markers both by quantitative real-time PCR and by antibody assays of peripheral blood samples from infected patients and NHP (Aotus sp.). Histological analyses of P. vivax parasites in organs of 13 infected NHP (Aotus and Saimiri species) demonstrated a major fraction of immature gametocytes in the parenchyma of the bone marrow, while asexual schizont forms were enriched to a somewhat lesser extent in this region of the bone marrow as well as in sinusoids of the liver. These findings suggest that the bone marrow is an important reservoir for gametocyte development and proliferation of malaria parasites.IMPORTANCEPlasmodium vivax malaria continues to cause major public health burdens worldwide. Yet, significant knowledge gaps in the basic biology and epidemiology of P. vivax malaria remain, largely due to limited available tools for research and diagnostics. Here, we present a systematic examination of tissue sequestration during P. vivax infection. Studies of nonhuman primates and malaria patients revealed enrichment of developing sexual stages (gametocytes) and mature replicative stages (schizonts) in the bone marrow and liver, relative to those present in peripheral blood. Identification of the bone marrow as a major P. vivax tissue reservoir has important implications for parasite diagnosis and treatment.

[Polymorphisms of IL-10 gene promoter and rheumatoid arthritis in a Colombian population]. / Polimorfismos de la región promotora del gen de la IL-10 y artritis reumatoide en una población colombiana.

INTRODUCTION: Rheumatoid arthritis is an inflammatory disease driven by TH1 CD4+ cells. Interleukin-10 is present in higher concentrations in serum and synovial fluid from patients with rheumatoid arthritis and has a marked anti-inflammatory activity. Furthermore, it is capable of stimulating B cells and increasing autoantibody production. Interleukin-10 synthesis is under genetic control. OBJECTIVE: Three polymorphisms of the promoter region were analyzed for interleukin-10 genes -1082, -819 and -592. Subjects were patients with rheumatoid arthritis compared with a control population for these genes. MATERIAL AND METHODS: One hundred two patients with rheumatoid arthritis and 102 matched healthy controls were studied. The following data were taken from the rheumatoid arthritis patients: age of disease onset, presence and titers of rheumatoid factor, and history of replacement joint surgery. Genotypes were obtained by polymerase chain reaction and sequence-specific primer method. The three polymorphisms are in strong linkage-disequilibrium and form three haplotypes -1082A/-819C/-592C, -1082A/-819T/-592A y -1082G/-819C/-592C. RESULTS: No association was detected between Interleukin-10 alleles, haplotypes/genotypes and rheumatoid arthritis. No significant differences occurred between interleukin-10 polymorphisms and age of disease onset, presence and titer of rheumatoid factor and history of major joint replacement. CONCLUSIONS: Interleukin-10 is an important regulator of the immune response and likely plays a role in the pathogenesis of rheumatoid arthritis. The current results suggested that Interleukin-10 promoter polymorphisms were not important for development or severity of rheumatoid arthritis.

A Plasmodium vivax Plasmid DNA- and Adenovirus-Vectored Malaria Vaccine Encoding Blood-Stage Antigens AMA1 and MSP142 in a Prime/Boost Heterologous Immunization Regimen Partially Protects Aotus Monkeys against Blood-Stage Challenge.

Malaria is caused by parasites of the genus Plasmodium, which are transmitted to humans by the bites of Anopheles mosquitoes. After the elimination of Plasmodium falciparum, it is predicted that Plasmodium vivax will remain an important cause of morbidity and mortality outside Africa, stressing the importance of developing a vaccine against P. vivax malaria. In this study, we assessed the immunogenicity and protective efficacy of two P. vivax antigens, apical membrane antigen 1 (AMA1) and the 42-kDa C-terminal fragment of merozoite surface protein 1 (MSP142) in a plasmid recombinant DNA prime/adenoviral (Ad) vector boost regimen in Aotus monkeys. Groups of 4 to 5 monkeys were immunized with plasmid DNA alone, Ad alone, prime/boost regimens with each antigen, prime/boost regimens with both antigens, and empty vector controls and then subjected to blood-stage challenge. The heterologous immunization regimen with the antigen pair was more protective than either antigen alone or both antigens delivered with a single vaccine platform, on the basis of their ability to induce the longest prepatent period and the longest time to the peak level of parasitemia, the lowest peak and mean levels of parasitemia, the smallest area under the parasitemia curve, and the highest self-cure rate. Overall, prechallenge MSP142 antibody titers strongly correlated with a decreased parasite burden. Nevertheless, a significant proportion of immunized animals developed anemia. In conclusion, the P. vivax plasmid DNA/Ad serotype 5 vaccine encoding blood-stage parasite antigens AMA1 and MSP142 in a heterologous prime/boost immunization regimen provided significant protection against blood-stage challenge in Aotus monkeys, indicating the suitability of these antigens and this regimen for further development.

Prevalencia comparativa de pólipos adenomatosos en personas de 45 a 49 años y en mayores de 50 años en una población colombiana: estudio de casos y controles / Comparative prevalence of adenomatous polyps in people aged 45 to 49 years and in people over 50 years of age in a Colombian population: a case-control study

RESUMEN Introducción: El cáncer de colon y recto (CCR) es el tercer cáncer más frecuente y la cuarta causa de muerte por cáncer en el mundo. En Colombia, es la tercera causa de muerte por cáncer. La recomendación más aceptada es hacer tamización con colonoscopia en personas de 50 a 75 años. Sin embargo, recientemente la Asociación Americana de Cáncer (ACS) ha recomendado iniciar la tamización a partir de los 45 años. En nuestro medio no hay estudios sobre prevalencia de pólipos adenomatosos en menores de 50 años. Objetivo: Comparar la prevalencia de pólipos adenomatosos durante colonoscopia de tamización en personas de 45-49 años (casos) y compararla con la de personas de 50 a 75 años (control). Materiales y métodos: Estudios de casos y controles. Los datos se recolectaron de forma prospectiva durante el periodo de enero 2018 hasta noviembre de 2019 en el centro de gastroenterología y endoscopia digestiva de Bogotá Colombia. Resultados: Se incluyeron 490 pacientes, 119 casos y 371 controles, relación casos:control fue 1:3. La prevalencia de pólipos en los casos 36,7% y en los controles (42,5%) p=0,279. Los pólipos adenomatosos se detectaron en 18,5% (IC 95% 12,4-26,6) de los casos y 32,4% (IC 95% 27,7-37,2) de los controles (p=0,004). Conclusión: La prevalencia de pólipos durante la colonoscopia de tamización en personas de 45-49 años es similar a la esperada en colonoscopias de tamización de personas entre los 50-75 años. Este hallazgo favorecería colonoscopia de tamización a partir de los 45 años.

ABSTRACT Introduction: Colon and rectal cancer (CRC) is the third most frequent cancer and the fourth cause of cancer death in the world. In Colombia, it is the third leading cause of death from cancer. The most accepted recommendation is to do colonoscopy screening in people 50 to 75 years old. However, recently the American Cancer Association (ACS) has recommended starting screening from the age of 45. In our environment there are no studies on the prevalence of adenomatous polyps in children under 50 years of age. Objective: To compare the prevalence of adenomatous polyps during screening colonoscopy in people aged 45-49 years (cases) and compare it with that of people aged 50 to 75 years (control). Materials and methods: Case-control studies. The data were collected prospectively during the period from January 2018 to November 2019 at the gastroenterology and digestive endoscopy center of Bogotá Colombia. Results: 490 patients were included, 119 cases and 371 controls, case: control ratio was 1: 3. The prevalence of polyps in cases 36.7% and in controls (42.5%) p=0.279. Adenomatous polyps were detected in 18.5% (95% CI 12.4-26.6) of the cases and 32.4% (95% CI 27.7-37.2) of the controls (p=0.004). Conclusion: The prevalence of polyps during screening colonoscopy in people aged 45-49 years is similar to that expected in screening colonoscopies of people between 50-75 years. This finding would favor screening colonoscopy from 45 years of age.

Surveillance of Levofloxacin Resistance in Helicobacter pylori Isolates in Bogotá-Colombia (2009-2014).

Increased resistance of Helicobacter pylori to clarithromycin and metronidazole has resulted in recommendation to substitute fluoroquinolones for eradication therapy. The aims of the study were to determine the prevalence and changes in primary levofloxacin resistance related to H. pylori gyrA sequences. The study utilized H. pylori strains isolated from patients undergoing gastroscopy in Bogotá, Colombia from 2009 to 2014. Levofloxacin susceptibility was assessed by agar dilution. Mutations in gyrA sequences affecting the quinolone resistance-determining region (QRDR) were evaluated by direct sequencing. Overall, the mean prevalence of primary levofloxacin resistance was 18.2% (80 of 439 samples). Resistance increased from 11.8% (12/102) in 2009 to 27.3% (21/77) in 2014 (p = 0.001). gyrA mutations in levofloxacin resistant strains were present in QRDR positions 87 and 91. The most common mutation was N87I (43.8%, 35/80) followed by D91N (28.8%, 23/80) and N87K (11.3%, 9/80). Levofloxacin resistance increased markedly in Colombia during the six-year study period. Primary levofloxacin resistance was most often mediated by point mutations in gyrA, with N87I being the most common QRDR mutation related to levofloxacin resistance.

Altered drug susceptibility during host adaptation of a Plasmodium falciparum strain in a non-human primate model.

Infections with Plasmodium falciparum, the most pathogenic of the Plasmodium species affecting man, have been reduced in part due to artemisinin-based combination therapies. However, artemisinin resistant parasites have recently emerged in South-East Asia. Novel intervention strategies are therefore urgently needed to maintain the current momentum for control and elimination of this disease. In the present study we characterize the phenotypic and genetic properties of the multi drug resistant (MDR) P. falciparum Thai C2A parasite strain in the non-human Aotus primate model, and across multiple passages. Aotus infections with C2A failed to clear upon oral artesunate and mefloquine treatment alone or in combination, and ex vivo drug assays demonstrated reduction in drug susceptibility profiles in later Aotus passages. Further analysis revealed mutations in the pfcrt and pfdhfr loci and increased parasite multiplication rate (PMR) across passages, despite elevated pfmdr1 copy number. Altogether our experiments suggest alterations in parasite population structure and increased fitness during Aotus adaptation. We also present data of early treatment failures with an oral artemisinin combination therapy in a pre-artemisinin resistant P. falciparum Thai isolate in this animal model.

Prevalencia y características histológicas de los pólipos diminutos del recto y del sigmoides en una población colombiana / Prevalence and histological characteristics of tiny rectal and sigmoid polyps in a Colombian population

Resumen Introducción: el cáncer de colon y recto (CCR) se origina a partir de pólipos adenomatosos y serrados. Por tanto, se recomienda que todos los pólipos colónicos sean resecados y enviados a patología. Sin embargo, en los pólipos diminutos (<5 mm) del recto y del sigmoides existe controversia sobre esta conducta, razón por la cual se ha planteado la estrategia de resecar y descartar o dejar in situ, a partir de la utilización de endoscopios avanzados (con una imagen de banda angosta [Narrow Band Imaging, NBI] u otras), y se logre concordancia con la histopatología, superior al 90 %. En nuestro medio, no hay estudios prospectivos con luz blanca sobre la prevalencia y las características histológicas de estos pólipos en el recto y el sigmoides. Por esta razón, se desarrolló este trabajo. Materiales y métodos: estudio de prevalencia analítica, prospectivo. Se incluyeron las colonoscopias de tamización realizadas en la Unidad de Gastroenterología de la Clínica Fundadores de Bogotá, entre enero y julio de 2018. Resultados: se incluyeron 719 pacientes. La prevalencia de pólipos diminutos en el recto y el sigmoides fue del 27 % (intervalo de confianza [IC], 95 %: 23,7-30,2 %). El 50 % eran pólipos adenomatosos, mientras que en 8 casos se presentó una displasia de alto grado (DAG). Entre los pólipos diminutos, 3 fueron tumores neuroendocrinos. No hubo cáncer en ninguna de las lesiones. Conclusiones: la mitad de los pólipos diminutos encontrados fueron adenomatosos y 8 (0,83 %) tuvieron DAG. Recomendamos resecar todos los pólipos diminutos hasta que los estudios locales realizados con NBI u otra tecnología demostrasen la capacidad para discriminar en más del 90 % los pólipos hiperplásicos (dejarlos in situ) o adenomatosos (resecarlos).

Abstract Introduction: Because colorectal cancer (CRC) originates from adenomatous and serrated polyps, it is recommended that all colonic polyps be resected and sent to pathology. However, there is controversy over this recommendation in the case of rectal and sigmoid polyps measuring less than 5 mm. Strategies using advanced NBI endoscopes to either "resect and discard" or leave "in situ" have been proposed. Concordance with histopathology of over 90% has been achieved. No prospective studies of the prevalence and histological characteristics of these rectal and sigmoid polyps had been done with white light in this country, so we undertook this study. Materials and methods: This is an analytical and prospective prevalence study. Screening colonoscopies performed in the gastroenterology unit of Clínica Fundadores in Bogotá between January and July 2018 were included. Results: Seven hundred nineteen patients were included. The prevalence of tiny polyps in the rectum and sigmoid colon was 27% (95% CI: 23.7 to 30.2%). Fifty percent were adenomatous, but eight cases had high grade dysplasia. Among the tiny polyps, three were neuroendocrine tumors. There was no cancer in any of the lesions. Conclusions: Half of the tiny polyps found were adenomatous, and eight (0.83%) had high grade dysplasia. We recommend resecting all tiny polyps until local studies conducted with NBI or other technology demonstrate the ability to discriminate between the more than 90% hyperplastic polyps (leaving them in situ) and adenomatous polyps (resect them).

Improved allele-specific PCR assays for detection of clarithromycin and fluoroquinolone resistant of Helicobacter pylori in gastric biopsies: identification of N87I mutation in GyrA.

Molecular testing can rapidly detect Helicobacter pylori susceptibility using gastric biopsies. Allele-specific polymerase chain reaction (ASP-PCR) was used to identify H. pylori 23S rRNA and gyrA mutation using gastric biopsies from Colombian patients and confirmed by PCR and sequencing of the 23S rRNA and gyrA genes. The sensitivity and specificity of ASP-PCR were compared with susceptibilities measured by agar dilution. Samples included gastric biopsies from 107 biopsies with H. pylori infections and 20 H. pylori negative. The sensitivity and specificity of ASP-PCR for the 23S rRNA gene were both 100%. The sensitivity and specificity of ASP-PCR for the gyrA gene, published in 2007 by Nishizawa et al., were 52% and 92.7%, respectively; the lower sensitivity was due to the presence of mutation N87I in our samples, which were not detected by the test. In this study, we designed new primers to detect the mutation N87I in GyrA. The ASP-PCR was performed with the original primers plus the new primers. The molecular test with the new primers improved the sensitivity to 100%. In conclusion, ASP-PCR provides a specific and rapid means of predicting resistance to clarithromycin and levofloxacin in gastric biopsies.

Procedimientos endoscópicos y pandemia COVID-19: consideraciones básicas / Basic considerations regarding endoscopic procedures during the COVID-19 pandemic

El SARS-Cov-2 es un coronavirus productor de la enfermedad COVID-19. Esta inició en Wuhan, capital de la provincia Hubei, China. En menos de cuatro meses la enfermedad se dispersó por el mundo, lo que dio origen a miles de muertes. La Organización Mundial de la Salud (OMS) la ha declarado pandemia. La humanidad está consternada, múltiples gobiernos han obligado al aislamiento total, con éxito variable debido a la negligencia de parte de la comunidad. En muchas ciudades las instituciones y el personal sanitario no son suficientes para atender la catástrofe. El aislamiento es la única estrategia eficaz para detener el crecimiento logarítmico de COVID-19. El motivo científico del aislamiento es que más del 60 % de los contagios surgen de personas asintomáticas. La enfermedad no solo produce síntomas respiratorios. El SARS-Cov-2, además, puede producir náuseas, dolor abdominal, vómito, diarrea, anosmia y ageusia. El 50% de los infectados pueden tener síntomas digestivos, que incluso preceden a los respiratorios. La ruta fecal-oral trasmite el virus, aún sin diarrea. En las unidades de endoscopia están todas las formas de contagio: aerosoles (vómitos, arcadas, eructos, flatos), materia fecal, contacto estrecho, contaminación del ambiente. Se deben suspender todas las endoscopias programadas para diagnóstico. Solo deben realizarse las urgentes y terapéuticas. Todo el personal de endoscopia debe tener medidas de protección estrictas. El paciente debe saber que en la sala de endoscopia puede contagiarse, con constancia en el consentimiento informado. Debe contactarse al paciente posendoscopia vía telefónica a los días 7 y 14 para indagar sobre todos los síntomas mencionados.(AU)

SARS-CoV-2 is the coronavirus which produces the dreaded COVID-19. Starting in Wuhan, the capital of China's Hubei province, it has spread it spread throughout the world in less than four months and has caused thousands of deaths. The WHO has declared it to be a pandemic. Humanity is shocked, and many governments have imposed total isolation. It has had varying success due to community negligence. In many cities, institutions and health personnel have not successfully managed this catastrophe. Isolation is the only effective strategy to stop the logarithmic growth of COVID 19. The scientific reason for isolation is that more than 60 % of infections arise from asymptomatic people. SARS-CoV-2 not only produces respiratory symptoms but can also cause nausea, abdominal pain, vomiting, diarrhea, anosmia and ageusia. Fifty percent of those infected may have digestive symptoms which may even precede respiratory symptoms. The fecal-oral route can transmit the virus even when there is no diarrhea. All forms of contagion are found in endoscopy units: aerosols from vomiting, retching, bel-ching, and flatus; fecal matter, close contact, and contamination of the environment. All diagnostic endoscopies should be discontinued. Only urgent and therapeutic endoscopy should be performed. All endoscopy personnel must have strict protection measures. Each patient should be informed, and sign an informed consent form, that the virus can be spread within the endoscopy room. After performance of endoscopy, the patient should be contacted by phone on days 7 and 14 to inquire about all symptoms mentioned.(AU)

Helicobacter pylori: resistencia múltiple en pacientes de Bogotá, Colombia / Helicobacter pylori: Multiple resistance in patients from Bogotá, Colombia

Resumen Introducción. La resistencia a los antibióticos es la principal causa del fracaso del tratamiento contra Helicobacter pylori; la claritromicina y el metronidazol son los antibióticos que generan mayor resistencia. En Colombia, la resistencia primaria a estos dos antibióticos y el uso excesivo de levofloxacina han alcanzado los límites aceptados (13,6, 83 y 16 %, respectivamente). A pesar de ello, se usa el tratamiento empírico combinando estos antibióticos en pacientes en los que ha fallado anteriormente. Objetivo. Determinar la resistencia a los antibióticos en pacientes previamente tratados para H. pylori en Bogotá, Colombia. Materiales y métodos. Se llevó a cabo un estudio descriptivo en el que se evaluó mediante dilución en agar la resistencia a la amoxicilina, la claritromicina, la levofloxacina y el metronidazol en 10 aislamientos provenientes de 5 pacientes con tres o cuatro tratamientos fallidos para H. pylori. La resistencia a los antibióticos se confirmó mediante secuenciación de ADN (Magrogen, Korea). Resultados. Ocho de los aislamientos presentaron resistencia a dos o más antibióticos y todos fueron resistentes a la levofloxacina. Los patrones de sensibilidad de los aislamientos provenientes del antro pilórico y del cuerpo del estómago, fueron diferentes en tres de los pacientes. Conclusión. Hasta donde se sabe, esta es la primera evidencia de resistencia múltiple de H. pylori en Colombia en pacientes previamente tratados. Los resultados evidenciaron las consecuencias del uso de un esquema ineficaz de tratamiento antibiótico y la necesidad de evaluar la sensibilidad a los antibióticos en diferentes sitios anatómicos del estómago. La resistencia múltiple limita el número de antibióticos útiles para erradicar H. pylori.

Abstract Introduction: The main cause for Helicobacter pylori infection treatment failure is antibiotic resistance, where clarithromycin and metronidazole play the main role. In Colombia, primary resistance as a consequence of the use of these two antibiotics and excessive levofloxacin use is above the accepted limit (13.6%, 83%, and 16%, respectively). Despite this fact, empirical therapies that include the combination of these antibiotics are used in patients with previous therapeutic failure. Objective: To determine antibiotic resistance in patients previously treated for H. pylori in Bogotá, Colombia. Materials and methods: We conducted a descriptive study that included ten isolates obtained from five patients with three or four previous failed treatments for H. pylori. Antibiotic resistance to amoxicillin, clarithromycin, levofloxacin, and metronidazole was investigated by agar dilution and confirmed by DNA sequencing (Magrogen, Korea). Results: Eight isolates were resistant to two or more antibiotics. All isolates were resistant to levofloxacin. Susceptibility patterns in isolates from the gastric antrum and the body of the stomach were different in three patients. Conclusion: As far as we know, this is the first evidence of multiple H. pylori resistance in Colombia in previously treated patients. Results demonstrated the consequences of using an ineffective antibiotic scheme and the need to assess antibiotic susceptibility in different anatomical sites of the stomach. The consequences of multiple resistance decrease possible antibiotic effectiveness to eradicate H. pylori in the future.

Serología del virus de la hepatitis B: para múltiples escenarios, múltiples exámenes / Serology of hepatitis B virus: multiple scenarios and multiple exams

Resumen El virus de la hepatitis B (VHB) tiene un gran impacto mundial. No obstante la disponibilidad de la vacuna, 2000 millones de personas se han infectado agudamente y, de ellos, 240 millones persisten crónicamente infectados. La infección tiene diferentes formas de presentación tales como infección aguda, infección crónica, infección oculta y reactivación cuando hay inmunosupresión. Así mismo, hay marcadores muy sensibles como el anticore, cuya positividad puede tener diversos significados. El recientemente descrito antígeno relacionado con el antígeno core es un marcador emergente que podría reemplazar al ácido desoxirribonucleico (ADN) viral. En la presente revisión se discuten los exámenes de laboratorio necesarios para el diagnóstico de los diferentes escenarios de la infección.

Abstract Hepatitis B virus (HBV) has an enormous global impact. Despite the availability of a vaccine, two billion people have been acutely infected. Of these, 240 million remain chronically infected. The infection has different forms of presentation including acute infections, chronic infections, hidden infections, and reactivation when there is immunosuppression. Similarly, there are very sensitive markers such as anti-core, but a positive test can have different meanings. This recently described antigen which is related to the core antigen is an emerging marker that could replace viral DNA. In this review we discuss the laboratory tests necessary for diagnosing the various scenarios of the infection.