Impact of irrigation with fish-processing effluents on nitrification and ammonia-oxidizer abundances in Patagonian arid soils.

This study aimed to evaluate the short-term effects of irrigation with diluted fish-processing effluents on soil pH, electrical conductivity, nitrification rate and abundance of ammonia oxidizers. To accomplish that, we constructed microcosms of soil from an undisturbed arid ecosystem of Patagonia, and irrigated them for 2 months with diluted effluents from a fish-processing factory or with water as control. In the initial soil sample, and along the experiment, we determined soil pH, electrical conductivity, and the concentration of inorganic nitrogen forms, which we used to calculate the net nitrification rate. We further estimated the abundances of ammonia-oxidizing archaea and bacteria in the initial soil sample and at the end of the experiment, by qPCR of amoA genes. Soil pH decreased and electrical conductivity increased in both irrigation treatments, although the effect was higher in effluent-irrigated microcosms. Soil nitrate + nitrite concentration, and thus the nitrification rate, was higher in effluent than in water-irrigated microcosms. The abundance of archaeal amoA genes was higher under effluent than water-irrigation, but that of bacterial amoA genes did not vary significantly between treatments. Neither ammonia-oxidizing archaea nor bacteria were influenced by the changes in soil pH and electrical conductivity induced by effluent irrigation.

Fish-processing effluent discharges influenced physicochemical properties and prokaryotic community structure in arid soils from Patagonia.

Along the Patagonian coast, there are processing factories of marine products in land that produce fish-processing effluents. The aim of the present study was to assess the physicochemical properties and the prokaryotic community composition of soils receiving fish-processing effluent discharges (effluent site-ES), and to compare them with those of unaltered soils (control site-CS) in the arid Patagonian steppe. We analyzed soil prokaryotic communities (using amplicon-based sequencing of 16S rRNA genes), soil physicochemical properties and fish-processing effluent characteristics. Soil moisture, electrical conductivity (EC), total and inorganic C were significantly higher in ES than in CS (p < .05). Effluent discharges induced a decrease in the total number of operational taxonomic units (OTUs) and in the Shannon diversity index (p = .0009 and .01, respectively) of soil prokaryotic community. Proteobacteria, Actinobacteria and Acidobacteria were the dominant phyla in CS, while ES soil showed a more heterogeneous composition of phyla. Linear discriminant analysis (LDA) effect size (LEfSe) analysis showed that fish-processing effluent discharges promoted an enrichment of Firmicutes and Bacteroidetes, which are active contributors to organic matter mineralization, along with a decrease of oligotrophic phyla such as Acidobacteria, Chloroflexi, Armatimonadetes and Nitrospirae, commonly found in nutrient-poor arid soils. The concentrations of inorganic C and ammonium, the EC and the soil moisture explained 73% of the total variation within the community composition. Due to its salinity and nutrients, fish-processing effluents have potential mainly for native salt-tolerant plant irrigation, however the impacts of soil prokaryotic community shifts over plant growth remain to be determined.

Influence of initial chemical composition and characteristics of pulps on the production and properties of lignocellulosic nanofibers.

This work aimed to study the influence of the initial chemical composition (glucans, lignin, xylan, and mannans), intrinsic viscosity, and carboxylate groups of pulps on the production process and final properties of lignocellulosic nanofibers (LCNF). Pulps of pine sawdust, eucalyptus sawdust, and sugarcane bagasse subjected to conventional pulping and highly oxidized processes were the starting materials. The LCNF were obtained by TEMPO mediated oxidation and mechanical fibrillation with a colloidal grinder. The nanofibrillation degree, chemical charge content, rheology, laser profilometry, cristallinity and atomic force microscopy were used to characterize the LCNF. The carboxylate groups, hemicelluloses and lignin of the initial pulps were important factors that affected the production process of LCNF. The results revealed that intrinsic viscosity and carboxylate groups of the initial pulps affected LCNF production process, whereas lignin and hemicelluloses influenced the viscosity of LCNF aqueous suspensions, the roughness of LCNF films, and the carboxylate groups content of LCNF.

Asymmetric synthesis of trans-4,5-disubstituted γ-butyrolactones involving a key allylboration step. First access to (-)-nicotlactone B and (-)-galbacin.

An efficient asymmetric synthesis of trans-4,5-disubstituted γ-butyrolactones from aldehydes and enantioenriched γ-carbamate alkenylboronates is reported. The cornerstone of this strategy is the implementation of sequential [3,3]-allyl cyanate rearrangement/allylboration/nucleophilic addition/cyclisation reactions. Diverse γ-butyrolactones such as the flavouring compounds, (+)-trans-whiskey lactone and (+)-trans-cognac lactone, as well as an advanced intermediate towards the first synthesis of natural products, (-)-nicotlactone B and (-)-galbacin, have thus been obtained.

Artificial biomembranes stabilized over spin coated hydrogel scaffolds. Crosslinking agent nature induces wrinkled or flat surfaces on the hydrogel.

Hydrogel films possess the ability of retain water and deliver it to a phospholipid bilayer mainly composed by DPPC (1,2-dipalmitoyl-sn-glycero-3-phosphocholine); moisture of the medium favors the stability of an artificial biomembrane when it is subjected to repetitive heating cycles. This hypothesis is valid when the hydrogel film, used as scaffold, present a flat surface morphology and a high ability for water releasing. On the other hand, when the sample presents a wrinkle topography (periodic undulations), free lateral molecular movement of the bilayer becomes lower, disfavoring the occurrence of clear phases/phase transitions according to applied temperature. Hydrogel films were prepared using HEMA (hydroxyethylmetacrylate), different crosslinking agents and initiators. This reaction mixture was spread over hydrophilic silicon wafers using spin coating technique. Resultant films were then exposed to UV light favoring polymeric chain crosslinking and interactions between hydrogel and substrate; this process is also known to generate tensile stress mismatch between different hydrogel strata, producing out-of-plane net force that generate ordered undulations or collapsed crystals at surface level. DPPC bilayers were then placed over hydrogel using Langmuir-Blodgett technique. Surface morphology was detected in order to clarify the behavior of these films. Obtained data corroborate DPPC membrane stability making possible to detect phases/phase transitions by ellipsometric methods and Atomic Force Microscopy due to their high hydration level. This system is intended to be used as biosensor through the insertion of transmembrane proteins or peptides that detect minimal variations of some analyte in the environment; artificial biomembrane stability and behavior is fundamental for this purpose.

Electrospinning deposition of hydrogel fibers used as scaffold for biomembranes. Thermal stability of DPPC corroborated by ellipsometry.

DPPC bilayers were deposited over thin hydrogel scaffolds using the Langmuir-Blodgett technique (with DPPC thickness ∼ 6.2 nm). Wrinkled hydrogels films were used to maintain a moist environment in order to enhance DPPC bilayer stability. Polymer mixtures were prepared using HEMA (as a base monomer) and DEGDMA, PEGDA575, PEGDA700 or AAm (as crosslinking agents); a thermal initiator was added to obtain a final pre-hydrogel (oligomer) with an adequate viscosity for thin film formation. This mixture was deposited as wrinkled film/fibers over hydrophilic silicon wafers using an electrospinning technique. Later, these samples were exposed to UV light to trigger photopolymerization, generating crosslinking bonds between hydrogel chains; this process also generated remnant surface stresses in the films that favored wrinkle formation. In the cases where DEGDMA and AAm were used as crosslinking agents, HEMA was added in higher amounts. The resultant polymer film surface showed homogenous layering with some small isolated clusters. If PEGDA575/700 was used as the crosslinking agent, we observed the formation of polymer wrinkled thin films, composed by main and secondary chains (with different dimensions). Moreover, water absorption and release was found to be mediated through surface morphology, ordering and film thickness. The thermal behavior of biomembranes was examined using ellipsometry techniques under controlled heating cycles, allowing phases and phase transitions to be detected through slight thickness variations with respect to temperature. Atomic force microscopy was used to determinate surface roughness changes according to temperature variation, temperature was varied sufficiently for the detection and recording of DPPC phase limits. Contact angle measurements corroborated and quantified system wettability, supporting the theory that wrinkled hydrogel films act to enhance DPPC bilayer stability during thermal cycles.

Eficacia de apósitos con antisépticos en la prevención de la infección asociada a catéteres / Efficacy of antiseptic dressings for the prevention of catheter-related infections

Objetivo: evaluar eficacia del apósito impregnado con clorhexidina para reducir la colonización y la infección asociada a catéter (IAC). Pacientes y métodos: ensayo clínico, aleatorizado, controlado. Cohorte de 77 catéteres en pacientes posquirúrgicos cardiovasculares menores de 1 año y/o 10 kg. Grupo experimental: apósito con Clorhexidina, con curación transparente. Grupo control: apósito transparente. Se compararon características de los pacientes y de los catéteres. Resultados: Los pacientes y la permanencia del catéter fueron similares en ambos grupos. La tasa cruda de IAC fue 5,2% en el grupo control y en el experimental 0% (p= 0,14). Tasa de colonización 15% en el control y 7% en el experimental (p=0,26). El recambio de curaciones fue mayor en el grupo control (1,3 recambios) vs. grupo experimental 0,7 (p= 0,009). Conclusiones: El grupo experimental mostró menor índice de colonización, aunque sin significación estadística Los cambios de curación fueron menores en este grupo (AU)

Objective: To evaluate the efficacy of chlorhexidine-impregnated dressings to reduce colonization and catheter-related infection (CRI). Patients and methods: A randomized, controlled clinical trial was conducted. A cohort of 77 catheters in post-cardiovascular surgical patients younger than 1 year and/or weighing less than 10 kg was assessed. Experimental group: Chlorhexidine-impregnated transparent dressings. Control group: Transparent dressings. Patient and catheter features were compared. Results: Patients and mean catheter insertion duration were similar in both groups. CRI rate was 5.2% in the control group and 0% in the experimental group (p= 0.14). Colonization rate was 15% in the control and 7% in the experimental group (p=0.26). Dressing change was more frequent in the control group: 1.3 changes vs. 0.7 in the experimental group (p= 0.009). Conclusions: Colonization rate was lower in the experimental group, although no statistical significance was found. Dressing changes were less frequent in this group (AU)

Uso y abuso de drogas durante el embarazo / Illicit drug use and abuse during pregnancy

El consumo y dependencia de sustancias, es un serio problema social con alta morbilidad materno-fetal. El aumento de la oferta y el contexto social favorecedor, permitió que la difusión del consumo sustancias tóxicas ilícitas, conlleve una incidencia creciente en gestantes consumidoras de sustancias y aumento de recién nacidos afectados por las prácticas tóxicas de sus madres. La evaluación del riesgo cuando la gestación es expuesta a las drogas es difícil, los resultados pueden estar sesgados por el consumo concomitante de otros tóxicos o por factores sicológicos y socio-sanitarios desfavorables. Aunque tampoco se definió un patrón específico de anomalías congénitas, se considera que el abuso de drogas, en general, comporta mayor riego de desenlace anómalo del embarazo, por un incremento del riesgo de malformaciones congénitas, debido a la probable teratogenicidad de algunas sustancias o de la morbilidad perinatal afectando el crecimiento fetal o el normal desarrollo del embarazo. También existen posibles repercusiones a largo plazo en la capacidad de aprendizaje y comportamiento de los niños expuestos intraútero, aunque no demostró efectivamente. Por lo tanto, todo embarazo en el que se detecto un hábito tóxico se debe considerar de mayor riesgo, tomando las medidas oportunas para lograr que las pacientes se alejen de éstas prácticas, apoyadas por un equipo multidisciplinario, idealmente antes del inicio del embarazo, lo que implica la adopción de medidas profilácticas de información y concienciación de las mujeres en edad fértil y de apoyo durante el embarazo y la lactancia para el abandono de la dependencia

Illicit drug use and dependence is a serious social problem with high maternal and fetal morbidity. Supply increase and propitious social context allowed that the diffusion of the use of illicit toxic substances entails a growing incidence in pregnant women who use illicit drugs and an increase of newborns affected by the practices of their mothers. Risk evaluation is difficult when gestation is exposed to illicit drugs because the results could be biased by the concomitant consumption of others toxic substances or by psychological and socio-sanitary unfavorable factors. Though a specific pattern of congenital anomalies has not been defined, in general it is considered that drug abuse has an increased risk of anomalous outcomes in pregnancies. This risk is caused by an increase in the risk of congenital malformations due to the probable teratogenicity of some substances or the perinatal morbility affecting the fetal growth or normal pregnancy development. Although it has not been demonstrated effectively, there are also possible long-term repercussions in the learning capacity and behavior of the children exposed intra uterus. In conclusion, all pregnancies exposed to illicit drugs must be considered high risk pregnancies and measures should be taken so that the patients avoid these practices supported by a multidisciplinary team. Ideally, this team should start working before pregnancy implying the adoption of preventive measures such as information and public awareness of women in fertile age and support during pregnancy and maternal lactation

Uso y abuso de drogas durante el embarazo: [revisión] / Illicit drug use and abuse during pregnancy: [review]

El consumo y dependencia de sustancias, es un serio problema social con alta morbilidad materno-fetal. El aumento de la oferta y el contexto social favorecedor, permitió que la difusión del consumo sustancias tóxicas ilícitas, conlleve una incidencia creciente en gestantes consumidoras de sustancias y aumento de recién nacidos afectados por las prácticas tóxicas de sus madres. La evaluación del riesgo cuando la gestación es expuesta a las drogas es difícil, los resultados pueden estar sesgados por el consumo concomitante de otros tóxicos o por factores sociológicos y socio-sanitarios desfavorables. Aunque tampoco se definió un patrón específico de anomalías congénitas, se considera que el abuso de drogas, en general, comporta mayor riego de desenlace anómalo del embarazo, por un incremento del riesgo de malformaciones congénitas, debido a la probable teratogenicidad de algunas sustancias o de la morbilidad perinatal afectando el crecimiento fetal o el normal desarrollo del embarazo. También existen posibles repercusiones a largo plazo en la capacidad de aprendizaje y comportamiento delos niños expuestos intraútero, aunque no demostró efectivamente. Por lo tanto, todo embarazo en el que se detecto un hábito tóxico se debe considerar de mayor riesgo, tomando las medidas oportunas para lograr que las pacientes se alejen de éstas prácticas, apoyadas por un equipo multidisciplinario, idealmente antes del inicio del embarazo, lo que implica la adopción de medidas profilácticas de información y concienciación de las mujeres en edad fértil y de apoyo durante el embarazo y la lactancia para el abandono de la dependencia.

Illicit drug use and dependence is a serious social problem with high maternal and fetal morbidity. Supply increase and propitious social context allowed that the diffusion of theuse of illicit toxic substances entails a growing incidence in pregnant women who use illicit drugs and an increase of newborns affected by the practices of their mothers. Risk evaluation is difficult when gestation is exposed to illicit drugs because the results could be biased by the concomitant consumption of others toxic substances or by psychological and socio-sanitary unfavorable factors. Though a specific pattern of congenital anomalies has not been defined, in general it is considered that drug abuse has an increased risk ofanomalous outcomes in pregnancies. This risk is caused by an increase in the risk of congenital malformations due to the probable teratogenicity of some substances or the perinatal morbility affecting the fetal growth or normal pregnancy development. Although it has not been demonstrated effectively, there are also possible long-term repercussions in the learning capacity and behavior of the children exposed intra uterus. In conclusion, all pregnancies exposed to illicit drugs must be considered high risk pregnancies and measures should be taken so that the patients avoid these practices supported by a multidisciplinary team. Ideally, this team should start working before pregnancy implying the adoption of preventive measures such as information and public awareness of women in fertile age and support during pregnancy and maternal lactation.

Prevalencia de la resistencia a metrodinazol, claritromicina y tetraciclina en Helicobacter pylori aislado de pacientes de la Región Metropolitana / Prevalence of metronidazole, clarithromycin and tetracycline resistance in Helicobacter pylori isolated from Chilean patients

Background: Helicobacter pylori is a pathogenic bacterium that infects a significant number of individuals. At present, therapeutic strategies to eradicate this bacterium depend on our knowledge of its resistance to antimicrobials. Aims: To evaluate the primary resistance of H pylori to metronidazole (Mtz), clarithromycin (Cla), and tetracycline (Tet) in symptomatic out-patients. Material and Methods: Fifty independent isolates of H pylori were obtained by endoscopy-assisted gastric biopsy from patients attending the University of Chile Clinical Hospital, that previously had not been treated with an eradication regime against this bacterium. The minimal inhibitory concentration of each antimicrobial was determined by agar dilution method. Results: Forty five and 27 percent of the isolates were found to be resistant to Mtz and Tet, respectively; the majority of these resistant isolates were from patients older than 21 years. Twenty percent of isolates were resistant to Cla; these were distributed evenly among different ages. Thirty two percent of the isolates were resistant to two or more of the antimicrobials. Conclusions: The high frequency of naturally occurring, antimicrobial-resistant strains of H pylori poses a national and world-wide problem for public health.

Prevalencia de la infección por helicobacter pylori según ensayo de la ureasa en pacientes derivados a la Unidad de Endoscopía del Hospital Clínico de la Universidad de Chile / Prevalence of infection by helicobacter pylori by urease test in patients derivates to the endoscopic section of Hospital Clínico de la Universidad de Chile

Helicobacter pylori is a pathogenic bacterium that infects a significant number of individuals. In Chile about 79 percent of the population is colonized. Aims: This study evaluate the prevalence of the H. pylori infection in symptomatic outpatients. Materials and Methods: 276 non selected patients were enrolled from Endoscopic Unit of Clinical Hospital of the University of Chile. The bacterium was detected by urease test. Results: H. pylori infection was found in 44,9 percent patients. Infection was higher in younger patients, 53,8 percent between 21-60 years, and was lower in older patients, 25,6 percent in older than 60 years. The risk of being H. pylori carrier is twofold higher in persons younger than 60 years as compared to those older than 60 years. Conclusion: The age would be modifier factors for H. pylori infection risk.

Resistencia antimicrobiana en Helicobacter pylori: aspectos clínicos y moleculares / Antimicrobial resistance of Helicobacter pylori: clinical and molecular aspects

Helicobacter pylori is a relevant pathogen for gastroduodenal diseases in human beings. Although its eradication often improves gastroduodenal diseases, H pylori is acquiring an elevated rate of resistance to various antimicrobials, such as metronidazole, clarithromycin, tetracycline and amoxicillin. Multi-drug resistance is a major problem to select the appropriate treatment of infectious diseases. To improve our understanding on the com-plexity of the problem, in this article we review the resistance mechanisms and give an update on H pylori antimicrobial resistance (Rev Méd Chile 2003; 131: 1313-20).

Development of the Spanish version of the Systematized Nomenclature of Medicine: methodology and main issues.

This presentation features linguistic and terminology management issues related to the development of the Spanish version of the Systematized Nomenclature of Medicine (SNOMED). It aims at describing the aspects of translating and the difficulties encountered in delivering a natural and consistent medical nomenclature. Bunge's three-layered model is referenced to analyze the sequence of symbolic concept representations. It further explains how a communicative translation based on a concept-to-concept approach was used to achieve the highest level of flawlessness and naturalness for the Spanish rendition of SNOMED. Translation procedures and techniques are described and exemplified. Both the computer-aided and human translation methods are portrayed. The scientific and translation team tasks are detailed, with focus on Newmark's four-level principle for the translation process, extended with a fifth further level relevant to the ontology to control the consistency of the typology of concepts. Finally the convenience for a common methodology to develop non-English versions of SNOMED is suggested.

Genetic polymorphisms of CYP2D6, CYP1A1 and CYP2E1 in the South-Amerindian population of Chile.

Polymorphisms of cytochrome P450 genes show pronounced interethnic variation and have not been previously studied in the South-Amerindian population, which probably has an Asian origin. Therefore, a similar distribution of allelic and haplotype frequencies of cytochrome P450 genes to Asian populations might be expected in South-Amerindians. We analysed the allelic frequencies and haplotype distribution for CYP2D6, CYP1A1 and CYP2E1 genes in the South-Amerindian population of Chile (Mapuche, n = 84) by Southern blot or polymerase chain reaction-restriction fragment length polymorphism. Similar allelic frequencies and haplotype distribution for the CYP2E1 gene between Mapuches and Asian populations were observed. Frequencies of the two major functional CYP2D6*1 and CYP2D6*2 alleles and the CYP2D6*5 null allele were similar to most populations world-wide. The alleles CYP2D6*3 and *9, absent in Asians, were not found in Mapuches. The CYP2D6*4 allelic group, uncommon in Asian populations, had a low frequency in Mapuches (0.036). However, the CYP2D6*10 allele (Ch1, Ch2 and J), highly frequent in Asians (0.33-0.50), had a very low frequency (0.018) in our study population. In addition, the presence of the common Chinese 44 kb XbaI fragment of CYP2D6 (0.19-0.31 in Asians) was not detected in South-Amerindians. Interestingly, high frequencies for the rare m2 and Val alleles of the CYP1A1 gene were found in Mapuches (0.821 and 0.91, respectively), and the rare Val/m2 haplotype was significantly higher in Mapuches (0.748) than in Asians (0.24) (P < 0.01). The frequency of this haplotype in Mapuches is the highest frequency reported to date. The population studied was in Hardy-Weinberg equilibrium for these polymorphisms. The major differences between Mapuches and Asians were for CYP2D6*10 and CYP1A1 allelic frequencies, as well as the absence of the common Chinese 44 kb XbaI fragment of CYP2D6. These differences might be interpreted as a consequence of genetic drifts caused by a founder effect in the settlement of South-Amerindians, or genetic selection caused by dietary or environmental factors.

Colgajos adipofaciales como cobertura en miembro superior / Adipofacial flaps as covering in superior member

Las lesiones graves de extremidades superiores constituyen un serio desafío de reparación. A pesar de existir múltiples técnicas descritas es bueno incorporar nuevas posibilidades que pueden resolver problemas complejos. El tejido fasciosubcutáneo constituye una unidad anatómica independiente con irrigación rica y bien establecida que permite levantar con seguridad Colgajos Adipofasciales, de reciente aplicación en nuestro medio. Se presentan dos casos de déficit de cobertura en extremidades superiores utilizando Colgajos Adipofasciales con buen resultado. Caso 1: Desforramiento y quemadura profunda extensa de miembro superior derecho con fractura conminuta de codo expuesta. Caso 2: Quemadura eléctrica grave de mano derecha con exposición de tendón y superficie articular metacarpofálica. Los Colgajos Adipofasciales ofrecen múltiples ventajas que favorecen su uso como: Fácil y rápida disección, flexible, deja mínima secuela en zona dadora y permite una rehabilitación precoz reduciendo la estadía hospitalaria

[Benzathine penicillin G and miocamycin in the treatment of children with streptococcal pharyngitis: a controlled therapeutic trial]. / Penicilina G benzatina y miocamicina en el tratamiento de niños con faringitis estreptococica: ensayo terapeutico controlado.

The aim of this study was to compare the clinical and bacteriologic effectiveness of miocamycin (Miocamin, Merck) as compared to benzathine penicillin G in the treatment of streptococcal pharyngitis. One hundred forty nine patients (aged 2 to 15 years) with culture proven Group A streptococcal pharyngitis were randomly assigned to receive miocamycin (15 mg/kg/day bid per os) or one injection of 600,000 or 1,200,000 units of benzathine penicillin G. The clinical response was similar in both groups, in terms of fever duration (16 +/- 14 hours with miocamycin vs 13 +/- 13 hours with penicillin) and normalization of appetite (87.7% of children with miocamycin vs 95.8% of children with penicillin after three days). Bacteriologic eradication of streptococcus was achieved in 66% of children treated with penicillin and 32% of those treated with miocamycin (p < 0.001). We conclude that a single benzathine penicillin is more effective eradicating streptococcus pyogenes than miocamycin in children with streptococcal pharyngitis.

Loxocelismo cutáneo hemolitico / Hemolytic cutaneous loxoscelism

La picadura por L.L. puede producir diversos cuadros clínicos que varían desde una pequeña ulceración banal hasta el cuadro de L.C.H. Presentamos el aso de un paciente que con un cuadro cutáneo tipo erisipela desarrolla un L.C.H. con fallo renal agudo y signos de hemólisis; Se hace referencia a las características de este tipo de picadura, su importância en nuestro medio. Se señalan pautas de diagnóstico y tratamiento

Loxocelismo cutáneo hemolitico / Hemolytic cutaneous loxoscelism

La picadura por L.L. puede producir diversos cuadros clínicos que varían desde una pequeña ulceración banal hasta el cuadro de L.C.H. Presentamos el aso de un paciente que con un cuadro cutáneo tipo erisipela desarrolla un L.C.H. con fallo renal agudo y signos de hemólisis; Se hace referencia a las características de este tipo de picadura, su importÔncia en nuestro medio. Se señalan pautas de diagnóstico y tratamiento (AU)