Mdm2 promotes Cdc25C protein degradation and delays cell cycle progression through the G2/M phase.

Upon different types of stress, the gene encoding the mitosis-promoting phosphatase Cdc25C is transcriptionally repressed by p53, contributing to p53's enforcement of a G2 cell cycle arrest. In addition, Cdc25C protein stability is also decreased following DNA damage. Mdm2, another p53 target gene, encodes a ubiquitin ligase that negatively regulates p53 levels by ubiquitination. Ablation of Mdm2 by siRNA led to an increase in p53 protein and repression of Cdc25C gene expression. However, Cdc25C protein levels were actually increased following Mdm2 depletion. Mdm2 is shown to negatively regulate Cdc25C protein levels by reducing its half-life independently of the presence of p53. Further, Mdm2 physically interacts with Cdc25C and promotes its degradation through the proteasome in a ubiquitin-independent manner. Either Mdm2 overexpression or Cdc25C downregulation delays cell cycle progression through the G2/M phase. Thus, the repression of the Cdc25C promoter by p53, together with p53-dependent induction of Mdm2 and subsequent degradation of Cdc25C, could provide a dual mechanism by which p53 can enforce and maintain a G2/M cell cycle arrest.

Aislamiento de microsporum spp. en dermatofitosis en pacientes de la región de Valparaíso - Chile / Microsporum spp. isolation in patients with dermatophytosis in region of Valparaíso - Chile

Introducción: las dermatofitosis por Microsporum spp. son infecciones frecuentes y han experimentado cambios en los distintos continentes, durante los últimos años. Objetivo: conocer las especies del género Microsporum que causan dermatofitosis, además de analizar las diferencias según sexo, edad y localización de estas infecciones, en pacientes de la región de Valparaíso. Materiales y Método: se revisaron los informes emitidos por el Laboratorio de Micología de la Facultad de Medicina de la Universidad de Valparaíso, durante el período 2002-2016. Se seleccionaron los informes de pacientes con examen microscópico directo con hifas, artroconidios y/o microconidios, además de cultivo con desarrollo de alguna especie del género Microsporum. En una planilla Excel se registraron las variables de edad, sexo, ubicación de la lesión, resultado del examen microscópico directo e identificación de la especie. Resultado: se incluyeron 285 pacientes, el 61,4% fueron mujeres, con un promedio de edad de 16 años. El grupo de los menores de 8 años fue el que presentó más infecciones, seguido por el de 16-35 años. Las localizaciones más frecuentes fueron cuero cabelludo y uñas. La tiña capitis se diagnosticó principalmente hasta los 35 años, luego de lo que predominó la onicomicosis de pies. El agente que se aisló con mayor frecuencia fue M. canis, seguido por M. gypseum. Conclusiones: las mujeres y los menores de 8 años presentaron la mayoría de las dermatofitosis por Microsporum spp. La tiña capitis fue la localización más frecuente, especialmente en niños y la onicomicosis fue la segunda en frecuencia, principalmente en adultos. M. canis fue el agente más frecuente, seguido por M. gypseum.

Introduction: the dermatophytosis caused by Microsporum spp. are frequent infections that have been undergone through changes in the different continents during the last years. Objective: to know the species of the Microsporum genus that cause dermatophytosis, besides to analyze the differences according to sex, age and location of these infections in patients from the region of Valparaíso. Materials and Method: the reports issued by the Mycology Laboratory of the University of Valparaíso during the period 2002-2016 were reviewed. Patients who had lesions compatible with dermatophytosis, direct microscopic examination with hyphae, arthroconidia and/or microconidia, and culture with development of some species of the genus Microsporum were selected. In an excel file, the variables of age, sex, location of the lesion, direct microscopic examination and identification of the species were recorded. Results: 285 patients were included in this study, 61.4% of them were women, with a mean age of 16 years. The group of children under 8 years old present greater quantity of infections, followed by the group of 16 to 35 years old. The most frequent locations were scalp and nails. The tinea capitis was diagnosed mainly until 35 years old, after which the foot onychomycosis become predominate. The agent that was most frequently isolated was M. canis, followed by M. gypseum. Conclusions: women and children under the age of 8 years presented the most infections. Tinea capitis was the most common site especially in children, and onychomycosis was the second most frequent, mainly in adults. M. canis was the most frequent agent followed by M. gypseum.

Malassezia pachydermatis en lesiones de piel en pacientes de la Quinta región de Chile / Malassezia pachydermatis on skin lesions in patients from the Fifth region of Chile

Introducción: M. pachydermatis es una levadura zoofílica que puede provocar pitiriasis versicolor y dermatitis seborreica. Objetivos: determinar la presencia de M. pachydermatis en pacientes con pitiriasis versicolor y dermatitis seborreica, además de evaluar el rendimiento del examen microscópico directo y cultivo, en estas infecciones. Materiales y Método: estudio descriptivo prospectivo realizado en el Hospital Carlos van Buren de Valparaíso, Chile, durante el período 2011-2013. Se seleccionaron pacientes con diagnóstico clínico de pitiriasis versicolor y dermatitis seborreica. La confirmación micológica fue realizada con examen microscópico directo y/o cultivo, además de pruebas especiales. Resultados: ingresaron al estudio 66 pacientes. El 60,6% fueron hombres, con un promedio de edad de 43 años. El 70% con VIH (+). El 90,9% presentó pitiriasis versicolor (principalmente hipopigmentadas en el tronco) y el 9% dermatitis seborreica. El examen microscópico directo fue positivo en el 95,4% de los casos y en el 62,12% de los cultivos. La especie más frecuente fue M. pachydermatis, seguida por M. furfur. Del total de pacientes: 50 se trataron por vía tópica, 15 con tópico más sistémico y 1 no fue tratado. Conclusiones: la mayoría de los pacientes ingresados a este estudio fueron hombres, VIH(+) y con lesiones de pitiriasis versicolor hipopigmentadas de tronco. La especie más frecuente fue M. pachydermatis. El tratamiento tópico fue el más indicado.

Introduction: M. pachydermatis is a zoophilic yeast that can cause pityriasis versicolor and seborrheic dermatitis. Objectives: to determine the presence of M. pachydermatis in patients with pityriasis versicolor and seborrheic dermatitis, in addition to evaluating the performance of direct microscopic examination and culture in these infections. Materials and Method: a prospective descriptive study conducted in the Carlos van Buren Hospital in Valparaíso, Chile, during the period 2011-2013. Patients with clinical diagnosis of pityriasis versicolor and seborrheic dermatitis were selected. Mycological confirmation was made with direct microscopic examination and / or culture, and special tests. Results: 66 patients entered the study. 60.6% were men, with an average age of 43 years. 70% with HIV (+). 90.9% had pityriasis versicolor (mostly hypopigmented in the trunk) and seborrheic dermatitis 9%. Direct microscopic examination was positive in 95.4% of cases and 62.12% of the cultures. The most frequent species was M. pachydermatis, followed by M. furfur. Of the patients: 50 were treated topically with 15 more systemic plus topical and 1 was untreated. Conclusions: most patients admitted to this study were men, HIV (+) and hypopigmented pityriasis versicolor lesions in the trunk. The most frequent species was M. pachydermatis. Topical treatment was the most appropriate.

Malassezia pachydermatis en lesiones de piel en pacientes de la Quinta región de Chile / Malassezia pachydermatis on skin lesions in patients from the Fifth region of Chile

Introducción: M. pachydermatis es una levadura zoofílica que puede provocar pitiriasis versicolor y dermatitis seborreica. Objetivos: determinar la presencia de M. pachydermatis en pacientes con pitiriasis versicolor y dermatitis seborreica, además de evaluar el rendimiento del examen microscópico directo y cultivo, en estas infecciones. Materiales y Método: estudio descriptivo prospectivo realizado en el Hospital Carlos van Buren de Valparaíso, Chile, durante el período 2011-2013. Se seleccionaron pacientes con diagnóstico clínico de pitiriasis versicolor y dermatitis seborreica. La confirmación micológica fue realizada con examen microscópico directo y/o cultivo, además de pruebas especiales. Resultados: ingresaron al estudio 66 pacientes. El 60,6% fueron hombres, con un promedio de edad de 43 años. El 70% con VIH (+). El 90,9% presentó pitiriasis versicolor (principalmente hipopigmentadas en el tronco) y el 9% dermatitis seborreica. El examen microscópico directo fue positivo en el 95,4% de los casos y en el 62,12% de los cultivos. La especie más frecuente fue M. pachydermatis, seguida por M. furfur. Del total de pacientes: 50 se trataron por vía tópica, 15 con tópico más sistémico y 1 no fue tratado. Conclusiones: la mayoría de los pacientes ingresados a este estudio fueron hombres, VIH(+) y con lesiones de pitiriasis versicolor hipopigmentadas de tronco. La especie más frecuente fue M. pachydermatis. El tratamiento tópico fue el más indicado.(AU)

Introduction: M. pachydermatis is a zoophilic yeast that can cause pityriasis versicolor and seborrheic dermatitis. Objectives: to determine the presence of M. pachydermatis in patients with pityriasis versicolor and seborrheic dermatitis, in addition to evaluating the performance of direct microscopic examination and culture in these infections. Materials and Method: a prospective descriptive study conducted in the Carlos van Buren Hospital in Valparaíso, Chile, during the period 2011-2013. Patients with clinical diagnosis of pityriasis versicolor and seborrheic dermatitis were selected. Mycological confirmation was made with direct microscopic examination and / or culture, and special tests. Results: 66 patients entered the study. 60.6% were men, with an average age of 43 years. 70% with HIV (+). 90.9% had pityriasis versicolor (mostly hypopigmented in the trunk) and seborrheic dermatitis 9%. Direct microscopic examination was positive in 95.4% of cases and 62.12% of the cultures. The most frequent species was M. pachydermatis, followed by M. furfur. Of the patients: 50 were treated topically with 15 more systemic plus topical and 1 was untreated. Conclusions: most patients admitted to this study were men, HIV (+) and hypopigmented pityriasis versicolor lesions in the trunk. The most frequent species was M. pachydermatis. Topical treatment was the most appropriate.(AU)

[Prevalence and antimicrobial susceptibility patterns of microorganisms causing bacteremia and fungemia in pediatric oncology patients]. / Prevalencia de microorganismos causantes de bacteriemias y fungemias en pacientes oncológicos pediátricos. Patrones de sensibilidad a los antimicrobianos.

The purpose of our research was to know the frequency of microorganisms causing bacteremia and/or fungemia in oncology patients from Hospital de Niños de Córdoba, as well as to describe the antimicrobial susceptibility patterns of bacteria isolated from January 2006 to April 2007. A total of 59 bacteremia and fungemia cases in 44 patients were studied. From the total number of isolations, 45.8% were gram-negative bacilli, 35.6% were gram-positive cocci, and 18.6% were yeasts. The global distribution of the most prevalent microorganisms was the following: Klebsiella spp. 15.3%; Staphylococcus aureus and Candida parapsilosis 11.9%; coagulase-negative staphylococci 10.2%; Escherichia coli 8.5%, and Pseudomonas aeruginosa 6.8%. More than 40% (41.2%) of enterobacteria showed an extended-spectrum beta-lactamase phenotype, and 20.0% of non-fermenting gram-negative bacilli were multi-resistant to tested antibiotics, while 38.5% of Staphylococcus spp. were methicillin-resistant. In conclusion, the most prevalent microorganisms were gram-negative bacilli, and within this group, enterobacteria evidenced a higher percentage of resistance to tested antibiotics.

Prevalencia de microorganismos causantes de bacteriemias y fungemias en pacientes oncológicos pediátricos: Patrones de sensibilidad a los antimicrobianos / Prevalence and antimicrobial susceptibility patterns of microorganisms causing bacteremia and fungemia in pediatric oncology patients

El objetivo del presente trabajo fue conocer la distribución y frecuencia de los microorganismos causantes de bacteriemias y fungemias en los pacientes oncológicos internados en el Hospital de Niños de Córdoba, así como describir sus patrones de sensibilidad a los antimicrobianos. Se estudiaron 59 episodios de bacteriemias y fungemias ocurridos entre enero de 2006 y abril de 2007 en 44 pacientes. Del total de los aislamientos recuperados, el 45,8% fueron bacilos gram-negativos, el 35,6% cocos gram-positivos y el 18,6% levaduras. La distribución global de los microorganismos más prevalentes fue: Klebsiella spp. 15,3%; Staphylococcus aureus 11,9%; Candida parapsilosis 11,9%; estafilococos coagulasa negativos 10,2%; Escherichia coli 8,5% y Pseudomonas aeruginosa 6,8%. El 41,2% de las enterobacterias aisladas presentó un fenotipo compatible con la presencia de alguna b-lactamasa de espectro extendido, y el 20,0% de los bacilos gram-negativos no fermentadores presentó multirresistencia a los antibióticos ensayados. En cuanto a los cocos gram-positivos, el 38,5% de los Staphylococcus spp. fue resistente a meticilina. Se puede concluir que los microorganismos más prevalentes en la población estudiada fueron los bacilos gram-negativos; dentro de este grupo las enterobacterias fueron las que presentaron mayor porcentaje de resistencia a los antibióticos ensayados.

The purpose of our research was to know the frequency of microorganisms causing bacteremia and/or fungemia in oncology patients from Hospital de Niños de Córdoba, as well as to describe the antimicrobial susceptibility patterns of bacteria isolated from January 2006 to April 2007. A total of 59 bacteremia and fungemia cases in 44 patients were studied. From the total number of isolations, 45.8% were gram-negative bacilli, 35.6% were gram-positive cocci, and 18.6% were yeasts. The global distribution of the most prevalent microorganisms was the following: Klebsiella spp. 15.3%; Staphylococcus aureus and Candida parapsilosis 11.9%; coagulase-negative staphylococci 10.2%; Escherichia coli 8.5%, and Pseudomonas aeruginosa 6.8%. More than 40% (41.2%) of enterobacteria showed an extended-spectrum b-lactamase phenotype, and 20.0% of non-fermenting gram-negative bacilli were multi-resistant to tested antibiotics, while 38.5% of Staphylococcus spp. were methicillin-resistant. In conclusion, the most prevalent microorganisms were gram-negative bacilli, and within this group, enterobacteria evidenced a higher percentage of resistance to tested antibiotics.

Optimization of native agar extraction from Hydropuntia cornea from Yucatán, México.

Response surface methodology (RSM) was used to determine optimum extraction conditions for yield, gelling temperature, melting temperature and apparent viscosity of native agar from the red alga Hydropuntia cornea. Two independent variables were selected during extraction, temperature (80, 90 and 100 degrees C) and time (2, 3 and 4 h). The extraction procedure using 100 degrees C and 3 h produced the greatest yield (43.3%), the greatest gelling temperature (32 degrees C) and the greatest melting temperature (78 degrees C). The extraction using 65 degrees C and 4 h produced the optimum statistical apparent viscosity (80.73 cPs), though agar yield under these conditions had low quality for industrial purposes. Temperature and time do not affect melting temperature, but do play an important role in gelling temperature. From the independent variables studied, extraction temperature is most important in producing an increase in yield, and time is the only variable that contributes significantly to increasing viscosity. Most of the physicochemical properties found in the native agar from H. cornea extracted at 100 degrees C/3 h were similar to commercial samples. These findings suggest the feasibility of using this colloid in spreads and soft-texture food products.

Azinphos methyl residues in shallow groundwater from the fruit production region of northern Patagonia, Argentina.

Groundwater samples were collected from monitoring wells along an area of intensive fruit production. Different types of correlations were investigated between soil physicochemical characteristics, depths and agricultural practices with pesticide detection frequency. In the three analyzed periods azinphos methyl, S-(3,4-diydro-4-oxobenzo[d]-[1,2,3]-triazin-3-ylmethyl)-O,O-dimethyl phosphorodithioate, showed a definite seasonal behavior related to the application pattern, increasing its concentration in the aquifer from October to November-December and then decreasing towards March. Samples obtained during the non-spraying season showed that azinphos methyl residues were lower than detection limit (LOD). An inverse correlation was observed between azinphos methyl concentration and the time elapsed since the last pesticide application. Seasonal events such as rain and irrigation influence the chemical concentration in the well, while no correlation was obtained between soil characteristics and azinphos methyl concentration. The soil attenuation capacity was not enough to prevent the presence of azinphos methyl in the aquifer during the application season.

Fast high performance liquid chromatography and ultraviolet-visible quantification of principal phenolic antioxidants in fresh rosemary.

An improved HPLC method is reported for the determination of rosemary's principal phenolic antioxidants, rosmarinic and carnosic acids, providing a fast and simultaneous determination for both of them by using a solid phase column. The analysis was performed with fresh methanolic extractions of Rosmarinus officinalis. To quantify the amount of antioxidants in a fast and reproducible way by means of UV-vis absorption measurements, a spectrophotometric multi-wavelength calibration curve was constructed based on the antioxidant contents obtained with the recently developed HPLC method. This UV-vis methodology can be extended to the determination of other compounds and herbs if the restrictions mentioned in the text are respected.

Nutrición de yodo en escolares de una zona con alta ingesta de yodo (Calama)comparada con zona de ingesta normal (Punta Arenas) / Iodine nutritional status in school-age children from an area of high iodine intake (Calama) compared with an area of normal intake (Punta Arenas)

Se evaluó la prevalencia de bocio por palpación de la glándula tiroidea en 1296 escolares de educación básica de una zona con alta ingesta de yodo (Calama) y se comparó con la de otra zona de ingesta normal de yodo (Punta Arenas). En una sub muestra del 10 por ciento de los escolares se midió la excreción de yodo urinaria y los niveles de hormonas tiroídeas en sangre. En ambas localidades se seleccionaron aleatoriamente del comercio 148 muestras de sal para consumo humano en las que se determinó la concentración de yodo. Se encontró una prevalencia de bocio de 11,1 por ciento (10,0 por ciento en varones y 12,5 por ciento en mujeres) mayoritariamente bocio grado Ia (7,2por ciento), sin diferencias por zona (11,6 por ciento en Calama y 10,6 por ciento en Punta Arenas). La concentración de yodo en la sal de consumo humano en ambas localidades fue adecuada a la exigencia actual del Reglamento Sanitario de los Alimentos (RSA) (33,3 µgI/g sal en Calama, 34,0 en Punta Arenas). La excreción de yodo en la orina fue significativamente más alta en Calama (460 ± 190 µgI/L)que en Punta Arenas (273 ± 155). No se detectaron diferencias en los niveles de T4 y TSH (Calama 7.1 ± 1.5 y 3.3 ± 1.8 y Punta Arenas 7.2 ± 1.1 y 2.9 ± 1.2 respectivamente) en tanto que las valores de T3 en ambas localidades mostraron diferencias significativas (103.9 ± 33.1 y 145.0 ± 26.0 respectivamente, p<0.001) . Se observó sólo una tendencia al aumento de la prevalencia de bocio, con persistencia de valores elevados de yoduria en Calama, lo que sugiere una fuente de yodo extra en esta localidad, cuya procedencia desconocemos y es necesario investigar.

Goiter prevalence determined by palpation of thyroid gland was evaluated in 1296 primary school age children from an area of high iodine intake (Calama) and compared with an area of normal iodine intake (Punta Arenas). Urinary iodine excretion and plasmatic thyroid hormones were measured in 10 percent of school children. In both areas 148 samples of salt for human consumption were randomly selected to measure iodine concentration. A goiter prevalence of 11,1 percent (10,0 percent in males and 12,5 percent in females) mainly goiter grade Ia (7,2 percent), without differences per area (11,6 percent in Calama and 10,6 percent in Punta Arenas) was found. Iodine concentration in salt for human consumption at both areas was adequated according the present Food Sanitary Regulation (FSR) in Chile (33,3 (gI/g salt in Calama, and 34,0 in Punta Arenas). Urinary iodine excretion was significantly higher in Calama (460 ( 190 (g I/L) than in Punta Arenas (273 ( 155 (g I/L). No differences were detected in T4 and TSH plasma levels (Calama 7.1 ( 1.5 and 3.3 (1.8; and Punta Arenas 7.2 ( 1.1 and 2.9 ( 1.2 respectively), while T3 plasma levels were significantly higher in Punta Arenas (103.9 ( 33.1 y 145.0 ( 26.0 respectivamente, p<0.001) . Only a tendency to a higher goiter prevalence with persistent and significantly higher urinary iodine excretion in children at Calama was observed, suggesting an extra source of iodine in this area, with an unkown origen that must be investigated.

Removal of azinphos methyl by alfalfa plants (Medicago sativa L.) in a soil-free system.

The objective of this study was to investigate the removal of azinphos methyl assisted by alfalfa plants, with special emphasis on the effects of this compound on some plant's physiological parameters. Hydroponic cultures of alfalfa (Medicago sativa L., var Romagnola) were employed as a model system. These cultures were exposed to a nutrient medium containing 10 mg/l of azinphos methyl. A first-order kinetic approach was used to describe the removal of azinphos methyl from the solution. After 20 days of culture, the initial amount of azinphos methyl was reduced to non-detectable levels in the presence of plants. In the absence of plants, 20% of azinphos methyl remained in the solution after 30 days of treatment. The half-life of the pesticide was reduced from 10.8 to 3.4 days in the presence of plants. The growth index of alfalfa plants exposed to azinphos methyl was negatively affected. Chlorophyll contents were reduced after 24 h of treatment and thereafter the levels were comparable to that of control plants. The peroxidase activity of alfalfa roots was not affected by the presence of azinphos methyl. In conclusion, alfalfa plants were able to survive when exposed to an effective concentration of 10 mg/l of azinphos methyl in the root zone, with some alterations on their physiological parameters.

Nutrición de yodo en escolares de cuatro zonas de Chile en el año 2001 / Iodine nutrition in school children of four areas of Chile during the year 2001

Background: In Chile, the recommendation for salt iodination was reduced from 100 to 40 ppm, after detecting high urinary iodine excretion in school age children. Aim: To assess iodine nutrition in school age children after the modification of salt iodination. Subjects and methods: Iodine nutrition was studied in 3712 school age Chilean children of primary level in 4 areas (Calama, Santiago, Temuco and Punta Arenas) through palpation of thyroid gland, urinary iodine excretion and iodine concentration in salt for human consumption of the surveyed areas. Results: A 6.4% goiter prevalence was found (5,9% in boys and 6,8% in girls). Grade Ia goiter was more common (5.0%), without detecting differences between areas (7.3% in Calama, 5.9% in Santiago, 5.9 in Temuco and 6.7 in Punta Arenas). Iodine concentration in salt for human consumption of the areas was adequate according to the recent modification of Chilean legislation (25.4 mgI/g salt in Calama, 36.2 in Santiago, 27.7 in Temuco and 33.4 in Punta Arenas). Urinary iodine excretion was very high according to recommendation in boys and girls (2838 and 2852 mgI/g salt in Calama, 700 and 837 in Santiago, 1318 and 1438 in Temuco, 407 and 312 in Punta Arenas). Conclusions: Endemic goiter is not longer a problem in Chile. Salt iodination is in agreement with present legislation. However, urinary iodine excretion increased in Calama and Temuco, did not change in Santiago and decreased only in Punta Arenas in spite of the changes in the legislation. It is necessary to investigate the causes of the high urinary iodine excretions detected in school age children, and it is very important to have a continuous surveillance of iodine nutrition in Chile (Rev Méd Chile 2003; 131: 1390-8).

[Extended-spectrum beta-lactamases in Klebsiella pneumoniae isolated at the Cordoba Children's Hospital, Argentina]. / Beta-lactamasas de espectro extendido en Klebsiella pneumoniae aisladas en el Hospital de Niños de Córdoba, Argentina.

The aim of the present study was to investigate the presence of extended-spectrum beta-lactamases (ESBL) in Klebsiella pneumoniae isolated at the "Hospital de Niños de Córdoba". The strains were collected from inpatients between January 1996 and July 2000. A total of 150 ESBL producer isolates were detected. During 1996 the prevalence of ESBL producer K. pneumoniae was 20%, but since 1998 the values have increased to approximately 60%. Phenotypic analysis such as isoelectric point (pl) and antibiotyping performed in 32 randomly selected isolates showed two different enzyme profiles: 81% had ESBL with pl = 7.9 and preferential activity against cefotaxime, while 19% showed ESBL with pl = 5.4 and preferential activity against ceftazidime. No isolates resistant to imipenem or ciprofloxacin were detected. Susceptibility to other antimicrobial agents varied, but resistance to gentamicin was strongly associated with ESBL producer isolates. Resistance determinants could be transferred to Escherichia coli by conjugation assays.

Effect of pesticide use in fruit production orchards on shallow ground water.

As a part of landscape-scale study, ground water samples were collected from 30 wells located in fruit production farms belonging to the valley of Neuquen river during the period 1995-1998 and analyzed for organophosphate pesticides. As a consequence of the leaching process, ground water from the Valley of Neuquen River frequently contained concentrations of organophosphorus pesticides that exceeded acute toxicity risk ratios established to protect aquatic life. It was found that some pesticides, as azinphos methyl, had a high detection frequency, 66% of the samples, with concentrations varying from no detection to 48.9 ppb. Dimethoate, metidathion and phosmet were also detected with frequencies of 14.1, 13.6 and 10.8% and with concentration ranks from no detection to a maximum value of 10.9, 2.0 and 15.5 ppb, respectively. Seasonal variations and temporal trends were found for these compounds in ground water.

ß-lactamasas de espectro extendido en Klebsiella peumoniae aisladas en el Hospital de Niños de Córdoba, Argentina / Extended-spectrum ß-lactamases in Klebsiella pneumoniae isolated in a pediatric hospital of Córdoba, Argentina

El objetivo de este estudio fue investigar la presencia de ß-lactamasas de espectro extendido (BLEE) en Klebsiella pneumoniae aisladas en el Hospital de Niños de Córdoba. Las cepas fueron obtenidas de pacientes internados entre enero de 1996 y julio de 2000. Se encontró un total de 150 aislamientos productores de BLEE. En el año 1996 la prevalencia de BLEE en K.pneumoniae fue del 20 por ciento, mientras que desde 1998 se ha mantenido en valores próximos al 60 por ciento. Estudios fenotípicos como la determinación del punto isoeléctrico (pl) y el antibiotipo realizados sobre un grupo de 32 aislamientos seleccionados al azar demostraron la presencia de dos tipos de enzimas. El 81 por ciento mostró una BLEE con pl=7,9 y mayor actividad sobre cefotaxima y el 19 por ciento restante presentó una BLEE con pl=5,4 y mayor actividad sobre ceftacidima. No se detectaron aislamientos resistentes a imipenem ni a ciprofloxacina. La sensibilidad a otras drogas fue variable, siendo muy frecuente la resistencia asociada a gentamicina. Los determinantes de resistencia pudieron transferirse por conjugación a Escherichia coli.

ß-lactamasas de espectro extendido en Klebsiella peumoniae aisladas en el Hospital de Niños de Córdoba, Argentina / Extended-spectrum ß-lactamases in Klebsiella pneumoniae isolated in a pediatric hospital of Córdoba, Argentina

El objetivo de este estudio fue investigar la presencia de ß-lactamasas de espectro extendido (BLEE) en Klebsiella pneumoniae aisladas en el Hospital de Niños de Córdoba. Las cepas fueron obtenidas de pacientes internados entre enero de 1996 y julio de 2000. Se encontró un total de 150 aislamientos productores de BLEE. En el año 1996 la prevalencia de BLEE en K.pneumoniae fue del 20 por ciento, mientras que desde 1998 se ha mantenido en valores próximos al 60 por ciento. Estudios fenotípicos como la determinación del punto isoeléctrico (pl) y el antibiotipo realizados sobre un grupo de 32 aislamientos seleccionados al azar demostraron la presencia de dos tipos de enzimas. El 81 por ciento mostró una BLEE con pl=7,9 y mayor actividad sobre cefotaxima y el 19 por ciento restante presentó una BLEE con pl=5,4 y mayor actividad sobre ceftacidima. No se detectaron aislamientos resistentes a imipenem ni a ciprofloxacina. La sensibilidad a otras drogas fue variable, siendo muy frecuente la resistencia asociada a gentamicina. Los determinantes de resistencia pudieron transferirse por conjugación a Escherichia coli. (AU)

Beta-lactamasas de espectro extendido en Klebsiella pneumoniae aisladas en el Hospital de Niños de Córdoba, Argentina. / [Extended-spectrum beta-lactamases in Klebsiella pneumoniae isolated at the Cordoba Childrens Hospital, Argentina]

The aim of the present study was to investigate the presence of extended-spectrum beta-lactamases (ESBL) in Klebsiella pneumoniae isolated at the [quot ]Hospital de Niños de Córdoba[quot ]. The strains were collected from inpatients between January 1996 and July 2000. A total of 150 ESBL producer isolates were detected. During 1996 the prevalence of ESBL producer K. pneumoniae was 20

, but since 1998 the values have increased to approximately 60

. Phenotypic analysis such as isoelectric point (pl) and antibiotyping performed in 32 randomly selected isolates showed two different enzyme profiles: 81

had ESBL with pl = 7.9 and preferential activity against cefotaxime, while 19

showed ESBL with pl = 5.4 and preferential activity against ceftazidime. No isolates resistant to imipenem or ciprofloxacin were detected. Susceptibility to other antimicrobial agents varied, but resistance to gentamicin was strongly associated with ESBL producer isolates. Resistance determinants could be transferred to Escherichia coli by conjugation assays.

[Streptococcus pneumoniae: evolution of antibiotic resistance in a pediatric hospital in Córdoba, Argentina]. / Streptococcus pneumoniae: evolución de la resistencia a los antimicrobianos en un hospital de niños de Córdoba, Argentina.

The wide variety of prevalence of antimicrobial resistant Streptococcus pneumoniae in different countries confirms the importance of determining local patterns of resistance. From 1992 to 2000, we studied the pattern of antimicrobial resistance in S. pneumoniae and its evolution along the years, using 468 strains isolated in the Hospital de Niños de Córdoba. A total of 177 isolates (37.8%) were not susceptible to penicillin, with 19% intermediate and 18.8% resistant strains. High and intermediate resistance levels to cefotaxime were 4.9% and 10.9%, respectively. Decreased susceptibility to trimethoprim/sulfamethoxazole (TMS), erythromycin, chloramphenicol, and rifampin was found in 194 isolates (41.5%), 32 (6.8%), 13 (2.8%) and 3 (0.6%), respectively. No isolates resistant to vancomycin were detected. The most commonly combined resistance patterns were: penicillin/TMS (35.6%) and penicillin/TMS/cefotaxime (11.8%). This study highlights the increased rate of drug resistant S. pneumoniae during the last years, and the importance of antimicrobial resistance surveillance of adequate empirical therapy involving local and regional susceptibility patterns.

Streptococcus pneumoniae: evolución de la resistencia a los antimicrobianos en un hospital de niños de Córdoba, Argentina / Streptococcus pneumoniae: evolution of antibiotic resistance in a pediatric hospital in Córdoba, Argentina

The wide variety of prevalence of antimicrobial resistant Streptococcus pneumoniae in different countries confirms the importance of determining local patterns of resistance. From 1992 to 2000, we studied the pattern of antimicrobial resistance in S. pneumoniae and its evolution along the years, using 468 strains isolated in the Hospital de Niños de Córdoba. A total of 177 isolates (37.8) were not susceptible to penicillin, with 19 intermediate and 18.8 resistant strains. High and intermediate resistance levels to cefotaxime were 4.9 and 10.9, respectively. Decreased susceptibility to trimethoprim/sulfamethoxazole (TMS), erythromycin, chloramphenicol, and rifampin was found in 194 isolates (41.5), 32 (6.8), 13 (2.8) and 3 (0.6), respectively. No isolates resistant to vancomycin were detected. The most commonly combined resistance patterns were: penicillin/TMS (35.6) and penicillin/TMS/cefotaxime (11.8). This study highlights the increased rate of drug resistant S. pneumoniae during the last years, and the importance of antimicrobial resistance surveillance of adequate empirical therapy involving local and regional susceptibility patterns.

Loci geneticos asociados al trastorno bipolar: estudios en poblacion colombiana / Genetic loci associated to bipolar disorder: studies in colombian population

Objetivos: Caracterizar una muestra de familias y tríos de una población colombiana aislada para mapear loci involucrados en la vulnerabilidad al Trastorno Afectivo Bipolar tipo I (TAB- I). Métodos: Se recolectan tríos y genealogías utilizando las entrevistas FIGS-DIGS en miembros de las familias y posibles afectados. El poder para detectar ligamiento (PDL) se estima por simulación. El modelo utilizado asume una frecuencia para el alelo afectado de 0.003, penetrancias de 0.01,0.81 y 0.9 y un marcador de cuatro alelos a 5cM del locus. Resultados: Se identificaron 28 familias con TAB-I, con 3.603 individuos y 160 afectados, y 246 tríos. Asumiendo homogeneidad genética y teniendo en cuenta la evidencia genética del mestizaje, las simulaciones mostraron PDL significativos de 100 por ciento para un LOD-score>3. Estamos examinando el desequilibrio promedio en tríos y tamizando en familias los cromosomas 12,18 y 21. Conclusión: Tenemos un grupo significativo de familias y trios pertenecientes a una población aislada con un poder para detectar ligamiento al Trastorno Afectivo Bipolar. Esto permite realizar estudios de ligamiento buscando genes involucrados en la vulnerabilidad al TAB-I en población Colombiana