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Tropical gar (Atractosteus tropicus) thrives in aquatic habitats with high levels of total nitrogen (TAN) and unionized ammonia (NH3). However, the tolerance of TAN and NH3, the excretion mechanisms involved, and the effects of these chemicals on routine metabolism are still unknown. Therefore, our objectives were to assess the acute toxicity of TAN and NH3 in A. tropicus juveniles after a 96-h exposure (LC50-96 h) to NH4Cl and after chronic exposure to two concentrations (15% and 30% of LC50-96 h TAN) for 12 days, as well as to evaluate the transcriptional effects associated with Rhesus proteins (rhag, rhbg, rhcg) and ion transporters (NHE, NKA, NKCC, and CFTR) in gills and skin; and to determine the effects of TAN and NH3 on routine metabolism through oxygen consumption (µM g-1 h-1) and gill ventilation frequency (beats min-1). LC50-96 h values were 100.20 ± 11.21 mg/L for TAN and 3.756 ± 0.259 mg/L for NH3. The genes encoding Rhesus proteins and ion transporters in gills and skin showed a differential expression according to TAN concentrations and exposure time. Oxygen consumption on day 12 showed significant differences between treatments with 15% and 30% TAN. Gill ventilation frequency on day 12 was higher in fish exposed to 30% TAN. In conclusion, A. tropicus juveniles are highly tolerant to TAN, showing upregulation of the genes involved in TAN excretion through gills and skin, which affects routine oxygen consumption and energetic cost. These findings are relevant for understanding adaptations in the physiological response of a tropical ancestral air-breathing fish.

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RESUMEN Las amilasas y celulasas de origen microbiano se han utilizado desde hace más de tres décadas en la industria. El aislamiento de microorganismos nativos con capacidad amilolítica y celulolítica es el punto de partida para aprovechar la biodiversidad microbiana en la producción de amilasas y celulasas con características específicas que permitan obtener nuevos productos y optimizar procesos industriales donde estas sean aplicables. El objetivo de este trabajo fue aislar, a partir de suelo de cinco humedales en Bogotá, cepas microbianas productoras de enzimas amilolíticas y celulolíticas. Se realizó la medición de halos de hidrólisis en agar almidón y agar carboximetilcelulosa. Se evaluó la actividad enzimática por medio de la producción de azúcares reductores, determinados mediante la técnica del ácido 3,5 dinitrosalicílico. Se seleccionaron cuatro aislamientos amilolíticos diferentes, todos identificados como Bacillus amyloliquefaciens, con actividades entre 480±35 y 752±33 U/mL a 60°C. Cinco aislamientos celulolíticos diferentes fueron seleccionado, dos identificados como Bacillus amyloliquefaciens, dos como Yersinia massiliensis y uno como Stenotrophomonas nitritireducens, con actividades enzimáticas entre 13.82 ± 2.5 y 19.11 ± 2.3 U/mL a 50°C. Estos resultados demuestran que dentro de la biodiversidad de los suelos de humedales de Bogotá existen microrganismos productores de amilasas y celulasas que podrían ser aplicadas en procesos industriales.

ABSTRACT The amylases and cellulases obtained from microorganisms have been used since more than three decades in industry. The isolation of native microbial strains with amylolytic and cellulolytic ability is the starting point to make the best of microbial biodiversity and support the production of amylases and cellulases with novel characteristics to obtain new products and optimize industrial processes where these enzymes can be applied. The objective of this work was to isolate microbial strains with the capacity to produce amylolytic and cellulolytic enzymes from the soil of five wetlands in Bogotá. Hydrolysis halos measurements in starch agar and carboxymethylcellulose agar were performed. The enzymatic activity was determined through the production of reducing sugars which were determined by 3,5-dinitrosalicylic acid method. Four different amylolytic isolations were selected and all of them were identified as Bacillus amyloliquefaciens. The amylolytic activity was between 480 ± 35 and 752±33 U/mL at 60°C. Five different cellulolytic strains were selected and two of them were identified as Bacillus amyloliquefaciens, two as Yersinia massiliensis and one as Stenotrophomonas nitritireducens. Their cellulolytic activities were from 13.82 ± 2.51 to 19.11 ± 2.3 U/mL at 50°C. These results demonstrate that as a part of the Bogota wetlands soil biodiversity there are microorganisms producing amylases and cellulases which might be applied in industrial processes.

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Propósito: elaborar una propuesta técnica que logre disminuir el ausentismo laboral del personal de enfermería del servicio de emergencia. Objetivo: describir las enfermedades ocupacionales que inciden con el ausentismo laboral del personal de enfermería del Servicio de Emergencia del Hospital Nacional de la Mujer "Dra. María Isabel Rodríguez", en el periodo de Enero a Octubre de 2018. Materiales y Métodos: estudio descriptivo, de corte transversal, observacional, retrospectivo y de campo. Resultados: la frecuencia del ausentismo esta mayormente condicionada por factores demográficos, socio-económicos y ocupacionales, los rangos de edades que presentaron mayores incapacidades es 31-40 años (60 días) y 21-30 años (48 días). Sobre el nivel de enfermedades ocupacionales que presentaron los profesionales de enfermería que laboran en el servicio de emergencia, 84.72% tienen nivel de riesgo alto que identifica los TME, patologías que afectan la columna y el conjunto de enfermedades infecciosas. Conclusiones: los TME (trastornos musculoesqueléticos), seguido de las patologías que afectan la columna, en su mayor parte lumbalgias, ciáticas y cervicalgias, reúnen el 62% de los días de incapacidad. Las enfermedades infecciosas que más incidencia tienen, según los días de baja que ocasionan, son las enfermedades de origen respiratorio 18.45%, resfriado común, sinusitis, gripes y neumonías. Recomendaciones: implementar programas de promoción de la salud y en particular para: la prevención de trastornos musculoesqueléticos, el bienestar psicosocial, la prevención del cáncer y el cuidado del corazón

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La cirugía mínimamente invasiva pasó de ser una alternativa, a un posible método de primera elección en cirugía valvular debido a sus beneficios en cuanto a infección, sangrado, estancia hospitalaria y funcionalidad. La canulación de ambas venas cavas, sin alterar los parámetros de la mínima invasividad, puede significar una disminución efectiva de los riesgos descritos con otras opciones y permite realizar procedimientos efectivos, tanto en cavidades izquierdas como derechas.

Minimally invasive surgery became more than an alternative, but a possible first election method for valve surgery because of its benefits in terms of infection, bleeding, hospital stay and functionality. The cannulation of both cava veins without altering the parameters of the minimal invasiveness may mean an effective reduction of the risks described in other options and allows us to perform procedures in both left and right cavities effectively.

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Honduras has one of the highest HIV prevalence rates in Central America. Data on HIV incidence are needed to identify groups at greatest need of prevention interventions to inform the national HIV response. We applied a test for recent infection to HIV-positive specimens from a biological and behavioral survey to estimate assay-derived incidence among men who have sex with men (MSM), female sex workers (FSW), and the Garifuna population in Honduras. Assay-derived estimates were compared to the mathematically modeled estimates in the same populations to assess plausibility of the assay-based estimates. Assay-derived incidence was 1.1% (95% CI 0.2-2.0) among MSM, 0.4% (95% CI 0.1-0.8) among the Garifuna, and 0% (95% CI 0-0.01) among FSWs. The modeled incidence estimates were similar at 1.03% among MSM, 0.30% among the Garifuna, and 0.23% among FSWs. HIV incidence based on the assay was highest among MSM in Honduras, lowest among FSWs, and similar to modeled incidence in these groups. Targeted programs on HIV prevention, care, and treatment are urgently needed for the MSM population. Continued support for existing prevention programs for FSWs and Garifuna are recommended.

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Because enzymatic activity is strongly suppressed by the cold, polar poikilotherms face significant adaptive challenges. For example, at 0°C the catalytic activity of a typical enzyme from a temperate organism is reduced by more than 90%. Enzymes embedded in the plasma membrane, such as the Na(+)/K(+)-ATPase, may be even more susceptible to the cold because of thermal effects on the lipid bilayer. Accordingly, adaptive changes in response to the cold may include adjustments to the enzyme or the surrounding lipid environment, or synergistic changes to both. To assess the contribution of the enzyme itself, we cloned orthologous Na(+)/K(+)-ATPase α-subunits from an Antarctic (Pareledone sp.; -1.8°C) and a temperate octopus (Octopus bimaculatus; ∼18°C), and compared their turnover rates and temperature sensitivities in a heterologous expression system. The primary sequences of the two pumps were found to be highly similar (97% identity), with most differences being conservative changes involving hydrophobic residues. The physiology of the pumps was studied using an electrophysiological approach in intact Xenopus oocytes. The voltage dependence of the pumps was equivalent. However, at room temperature the maximum turnover rate of the Antarctic pump was found to be 25% higher than that of the temperate pump. In addition, the Antarctic pump exhibited a lower temperature sensitivity, leading to significantly higher relative activity at lower temperatures. Orthologous Na(+)/K(+) pumps were then isolated from two tropical and two Arctic octopus. The temperature sensitivities of these pumps closely matched those of the temperate and Antarctic pumps, respectively. Thus, reduced thermal sensitivity appears to be a common mechanism driving cold adaptation in the Na(+)/K(+)-ATPase.

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BACKGROUND: Transmitted drug resistance (TDR) reduces the efficacy of antiretroviral treatment and is a public health concern. OBJECTIVES: To gain insight in the epidemiology of TDR in Honduras by evaluating the amount of TDR in a representative sample of newly diagnosed individuals and by determining whether these are recent or established infections. STUDY DESIGN: Two hundred treatment-naïve, newly diagnosed HIV-positive individuals representing different population groups (general population, Garifunas ethnic group, female sex workers and men who have sex with men) and different geographic regions were enrolled during April 2004-April 2007. The HIV-1 pol gene was sequenced to identify drug-resistant mutations and TDR was scored as recommended by the WHO. Specimens were classified as recent or established infections using the BED assay. RESULTS: Among 200 samples analyzed from Honduran patients the prevalence of TDR was 7% (95% CI: 3.9-11.5%), 5% for non-nucleoside reverse transcriptase inhibitors (NNRTIs), 3% for nucleoside reverse transcriptase inhibitors (NRTIs) and 0.5% for protease inhibitors (PIs). Testing of these samples with the BED assay revealed that 12% of the specimens were associated with recent infections. TDR was significantly more common in specimens with recent infection (21%) than established infection (5%) (p=0.016). CONCLUSIONS: The prevalence of TDR in Honduras was moderate (7%). The percentage of specimens who were recently infected was low (12%), suggesting that late HIV diagnosis is common. The TDR prevalence was higher in recent than in established infections, which may indicate that TDR is increasing over time. The higher prevalence of NNRTI and NRTI mutations as compared to PI mutations is probably due to a broader and longer use of these drugs in Honduras.

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Injection drug use is a growing but understudied problem in Tijuana, a city situated on the northwestern Mexico-U.S border. The authors studied factors associated with receptive needle sharing in an effort to inform prevention activities. In 2003, street-recruited injection drug users (IDUs) in Tijuana underwent interviews on injection risk behaviors and rapid HIV antibody tests. Logistic regression was used to identify correlates of receptive needle sharing at the last injection episode. Of 402 IDUs, 87.6% were male; the median age was 34. HIV prevalence was 4.01% (95% CI: 2.29-6.51). One third reported receptive needle sharing at last injection. Factors independently associated with receptive needle sharing were years living in Tijuana (Adjusted Odds Ratio [AdjOR]= 0.97 per year, 95% CI: 0.96-0.99), being bisexual/homosexual (AdjOR=2.12; 95% CI: 1.30 - 3.44), unemployed (AdjOR=2.5; 95% CI: 1.52-4.10), never having an HIV test (AOR: 4.02; 95% CI: 2.44-6.60), having friends who placed importance on avoiding HIV (AdjOR: 0.36; 95% CI: 0.19-0.68) and last injecting in a shooting gallery (AdjOR=1.98; 95% CI: 1.21-3.24). These results underscore the need to increase access to voluntary HIV testing and counseling to IDUs and migrants in Tijuana, as well as expand access to sterile syringes in an effort to avert widespread HIV transmission.

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