Osteomielitis fúngica en niños quemados / Fungal osteomyelitis in burned children

Introducción: En pacientes pediátricos quemados la osteomielitis fúngica es una complicación infrecuente que conduce a una significativa morbilidad. La información en la literatura está limitada a unos escasos reportes de casos. Objetivo: Describir las características clínicas, epidemiológicas y de evolución de niños quemados con osteomielitis fúngica. Métodos: Se llevo a cabo un estudio retrospectivo y descriptivo de pacientes mayores de 1 mes y menores de 18 años quemados con osteomielitis fúngica internados en el hospital Juan P. Garrahan, un hospital terciario en Buenos Aires, Argentina. Resultados: entre enero del 2007 y enero del 2017, de 600 niños quemados, 9 pacientes presentaron diagnóstico confirmado de osteomielitis fúngica. La mediana de edad fue de 42.5 meses (RIC, 27-118 meses) y la mediana de superficie quemada fue de 33.5% (RIC, 18.5-58%). La osteomielitis fue diagnosticada con una mediana de 30 días luego de la quemadura. Las localizaciones más frecuentes de osteomielitis fueron los miembros superiores y a nivel de calota. Los microorganismos aislados a partir del cultivo de hueso fueron: Fusarium spp. en tres pacientes, Mucor spp. en un paciente; Trichosporon asahii en un paciente; Cándida albicans en dos pacientes y Candida parapsilosis en dos pacientes. En dos casos la infección fúngica fue asociada con aislamientos bacteriano concomitante. Todos los pacientes presentaron hallazgos histopatológicos compatibles con osteomielitis. La mediana de tiempo de tratamiento fue de 44.5 días (RIC, 34.5- 65.5 días). Seis pacientes (67%) presentaron secuela motora. Conclusión: La osteomielitis fúngica fue infrecuente Candida spp. y Fusarium spp. fueron los hongos más comúnmente identificados. La secuela funcional fue frecuente (AU)

Introduction: In pediatric burn patients fungal osteomyelitis is a rare complication that leads to significant morbidity. Data in the literature are limited to sporadic case reports. Objective: To describe the clinical and epidemiological features and outcome in burned children with fungal osteomyelitis. Methods: A retrospective descriptive study was conducted in burn patients older than 1 month and younger than 18 years admitted to Hospital Juan P. Garrahan, a tertiary hospital in Buenos Aires, Argentina. Results: Between January 2007 and January 2017, of 600 burned children, nine had a confirmed diagnosis of fungal osteomyelitis. Median age was 42.5 months (IQR, 27-118 months) and median burn surface was 33.5% (IQR, 18.5-58%). Osteomyelitis was diagnosed at a median of 30 days after the burn. The most common location of osteomyelitis were the upper limbs and skull. The microorganisms isolated form bone cultures were Fusarium spp. in three patients, Mucor spp. in one patient; Trichosporon asahii in one patient; Candida albicans in two patients; and Candida parapsilosis in two patients. In two cases the funal infection was associated with concomitant bacterial isolation. In all patients, the histopathological findings were compatible with osteomyelitis. Median duration of treatment was 44.5 days (IQR, 34.5-65.5 days). Six patients (67%) had motor sequelae. Conclusion: Fungal osteomyelitis is a rare disease. Candida spp. and Fusarium spp. were most frequently identified fungi. Functional sequelae were common (AU)

Is anaerobic digestion effective for the removal of organic micropollutants and biological activities from sewage sludge?

The occurrence of emerging organic micropollutants (OMPs) in sewage sludge has been widely reported; nevertheless, their fate during sludge treatment remains unclear. The objective of this work was to study the fate of OMPs during mesophilic and thermophilic anaerobic digestion (AD), the most common processes used for sludge stabilization, by using raw sewage sludge without spiking OMPs. Moreover, the results of analytical chemistry were complemented with biological assays in order to verify the possible adverse effects (estrogenic and genotoxic) on the environment and human health in view of an agricultural (re)use of digested sludge. Musk fragrances (AHTN, HHCB), ibuprofen (IBP) and triclosan (TCS) were the most abundant compounds detected in sewage sludge. In general, the efficiency of the AD process was not dependent on operational parameters but compound-specific: some OMPs were highly biotransformed (e.g. sulfamethoxazole and naproxen), while others were only slightly affected (e.g. IBP and TCS) or even unaltered (e.g. AHTN and HHCB). The MCF-7 assay evidenced that estrogenicity removal was driven by temperature. The Ames test did not show point mutation in Salmonella typhimurium while the Comet test exhibited a genotoxic effect on human leukocytes attenuated by AD. This study highlights the importance of combining chemical analysis and biological activities in order to establish appropriate operational strategies for a safer disposal of sewage sludge. Actually, it was demonstrated that temperature has an insignificant effect on the disappearance of the parent compounds while it is crucial to decrease estrogenicity.

Solvent screening methodology for in situ ABE extractive fermentation.

Solvent screening for in situ liquid extraction of products from acetone-butanol-ethanol (ABE) fermentation was carried out, taking into account biological parameters (biocompatibility, bioavailability, and product yield) and extraction performance (partition coefficient and selectivity) determined in real fermentation broth. On the basis of different solvent characteristics obtained from literature, 16 compounds from different chemical families were selected and experimentally evaluated for their extraction capabilities in a real ABE fermentation broth system. From these compounds, nine potential solvents were also tested for their biocompatibility towards Clostridium acetobutylicum. Moreover, bioavailability and differences in substrate consumption and total n-butanol production with respect to solvent-free fermentations were quantified for each biocompatible solvent. Product yield was enhanced in the presence of organic solvents having higher affinity for butanol and butyric acid. Applying this methodology, it was found that the Guerbet alcohol 2-butyl-1-octanol presented the best extracting characteristics (the highest partition coefficient (6.76) and the third highest selectivity (644)), the highest butanol yield (27.4 %), and maintained biocompatibility with C. acetobutylicum.

Continuous operation of a fluidized bed reactor for the removal of estrogens by immobilized laccase on Eupergit supports.

The feasibility of the operation of a fluidized bed reactor for the removal of estrogens by immobilized laccase was investigated in order to improve the degradation yields and enzyme stability previously obtained with packed bed reactors. High removal levels (between 76 and 90%) and significantly prolonged stability of the biocatalyst over 16 days were attained. In parallel, a decrease up to 90% in the estrogenic activity of the effluent was measured. Thus, the technology presented seems a promising tool to increase the applicability of laccases in bioremediation processes.

Degradation of estrogens by laccase from Myceliophthora thermophila in fed-batch and enzymatic membrane reactors.

Several studies reported that natural and synthetic estrogens are the major contributors to the estrogenic activity associated with the effluents of wastewater treatment plants. The ability of the enzyme laccase to degrade these compounds in batch experiments has been demonstrated in previous studies. Nevertheless, information is scarce regarding in vitro degradation of estrogens in continuous enzymatic bioreactors. The present work constitutes an important step forward for the implementation of an enzymatic reactor for the continuous removal of estrone (E1) and estradiol (E2) by free laccase from Myceliophthora thermophila. In a first step, the effect of the main process parameters (pH, enzyme level, gas composition (air or oxygen) and estrogen feeding rate) were evaluated in fed-batch bioreactors. E1 and E2 were oxidized by 94.1 and 95.5%, respectively, under the best conditions evaluated. Thereafter, an enzymatic membrane reactor (EMR) was developed to perform the continuous degradation of the estrogens. The configuration consisted of a stirred tank reactor coupled with an ultrafiltration membrane, which allowed the recovery of enzyme while both estrogens and degradation products could pass through it. The highest removal rates at steady state conditions were up to 95% for E1 and nearly complete degradation for E2. Furthermore, the residual estrogenic activity of the effluent was largely reduced up to 97%.

Immobilization of laccase by encapsulation in a sol-gel matrix and its characterization and use for the removal of estrogens.

Laccase from Myceliophthora thermophila was immobilized by encapsulation in a sol-gel matrix based on methyltrimethoxysilane and tetramethoxysilane. The amount of laccase used for the preparation of the hydrogel was in the range 2.2-22 mg of protein/mL sol and the corresponding enzymatic activities were in the range 5.5-17.0 U/g biocatalyst. The kinetic parameters of the encapsulated laccase showed that the immobilized enzyme presented lower affinity for the substrate 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS). However, the stability of laccase was significantly enhanced after immobilization; thus, both pH and thermal stability improved about 10-30% and tolerance to different inactivating agents (NaN(3) , ZnCl(2) , CoCl(2) , CaCl(2) , methanol, and acetone) was 20-40% higher. The reusability of the immobilized laccase was demonstrated in the oxidation of ABTS for several consecutive cycles, preserving 80% of the initial laccase activity after 10 cycles. The feasibility of the immobilized biocatalyst was tested for the continuous elimination of Acid Green 27 dye as a model compound in a packed-bed reactor (PBR). Removals of 70, 58, 57, and 55% were achieved after four consecutive cycles with limited adsorption on the support: only 10-15%. Finally, both batch stirred tank reactor (BSTR) operated in several cycles and PBR, containing the solid biocatalyst were applied for the treatment of a solution containing the endocrine disrupting chemicals (EDCs): estrone (E1), 17ß-estradiol (E2), and 17α-ethinylestradiol (EE2). Eliminations of EDCs in the BSTR were higher than 85% and the reusability of the biocatalyst for the degradation of those estrogens was demonstrated. In the continuous operation of the PBR, E1 was degraded by 55% and E2 and EE2 were removed up to 75 and 60%, at steady-state conditions. In addition, a 63% decrease in estrogenic activity was detected.

[Assessment of differential lung function by electrical impedance tomography]. / Evaluación de la función pulmonar unilateral mediante tomografía por impedancia eléctrica.

OBJECTIVE: To compare unilateral lung function estimated by 2 methods: electrical impedance tomography (EIT) and ventilation-perfusion lung scintigraphy. PATIENTS AND METHODS: This prospective clinical study was carried out in the pulmonary function laboratory of a general hospital. Twenty patients diagnosed with lung cancer (17 men and 3 women, ranging in age from 25 to 77 years) who were candidates for lung resection underwent ventilation-perfusion lung scanning breathing a radioactive gas. Differential lung function was estimated based on images taken at 2 intercostal spaces in which ventilation and perfusion were represented by changes in bioelectrical impedance. Each lung's contribution to overall respiratory function was also calculated based on scintigraphy. RESULTS: The right lung contributed a mean (SD) of 54% (9%) of ventilation (range, 32%-71%) according to EIT. Scintigraphy similarly estimated the right lung's contribution to be 52% (10%) of total ventilation (range, 31%-80%) and 50% (9%) of perfusion (range, 37%-71%). The difference between the 2 estimates was not significant (t test), and the correlation coefficients between them were r=0.90 for ventilation and r=0.72 for perfusion (P< .05 in both cases). The analysis of agreement showed that the mean difference between the methods was 1.9% (95% confidence interval [CI], 10.5% to -6.8%) for ventilation and 3.4% (95% CI, 17.1% to -10.3%) for perfusion. CONCLUSIONS: EIT is able to estimate differential lung function as accurately as ventilation-perfusion scintigraphy.

Evaluation of biodiesel as bioremediation agent for the treatment of the shore affected by the heavy oil spill of the Prestige.

The efficiency of different bioremediation products (nutrients, microorganisms and biodiesel) was tested using tiles located in both the supra-littoral and intertidal zones of a beach that was affected by the heavy oil spill of the Prestige. Neither nutrients nor microorganisms meant an improvement with respect to the natural processes. The addition of biodiesel improved the appearance of the treated tiles and apparently accelerated the degradation of the aliphatic and aromatic fractions of the residual fuel oil. Nevertheless, PAHs degradation was similar and very high in all the treatments (80-85% after 60 days). On the other hand, the evolution with time of the amount of vanadium was similar to that of 17alpha(H),21beta(H)-hopane, so it was concluded that vanadium could also be used to estimate the extent of oil degradation in the field. These results also suggested that the residual fuel oil mineralization was very low throughout 1 year in all the treatments. Moreover, the increase of the oxygen content of the residual oil from around 1% till 4-8% indicated that the partial oxidation of hydrocarbons took place, and that the hydrocarbon oxidation products accumulated in the polar fractions. In general, the results pointed out that bioremediation techniques were not suitable for the recovery of shores affected by heavy oil spills.

Factores que determinan el manejo de los desechos sólidos hospitalarios generados en el Servicio de Emergencia del Hospital Eugenio Espejo y el impacto que causa en la salud del usuario interno Quito diciembre 2006 / Factors that determine the handling of the hospitable solid remainders generated in the Service of Emergency of the Hospital Eugene Mirror and the impact that causes in the health of the internal user exempt December 2006

La presente investigación se refiere a los “factores que determinan el manejo de los desechos sólidos hospitalarios generados en el Servicio de Emergencia del Hospital Eugenio Espejo y el impacto que causa en la salud del usuario interno Quito 2006”. La hipótesis planteada sobre los factores que determinan la forma de eliminación de desechos sólidos hospitalarios, está relacionado directamente con el nivel de conocimiento del personal del servicio, la presencia de personal nuevo no capacitado especialmente estudiantes y la insuficiente dotación de insumos. Nuestro objetivo general planteado fue, contribuir al mejoramiento del ambiente laboral hospitalario a través de la eliminación segura de los desechos sólidos generados en el servicio de emergencia del Hospital Eugenio Espejo de agosto a septiembre del 2006. Para el cual se utilizó un estudio prospectivo transversal analítico y observacional, de un universo de 112 personas hemos tomado una muestra significativa de 42 personas del equipo multi disciplinario de salud, para la recolección de la información se aplicó encuestas y la ficha de observación. Se encontró que en general el proceso de manejo se lo realiza en forma inadecuada en un 62 por ciento que implica un grave problema para el ambiente laboral, así como también se capacita esporádicamente al personal sobre el tema, también se obtuvo un alto porcentaje de pinchazos en todo el personal, con un caso de hepatitis B.

Trials of bioremediation on a beach affected by the heavy oil spill of the Prestige.

The objective of this study was to assess the efficiency of several bioremediation products in accelerating the in situ biodegradation of the heavy fuel oil spill of the Prestige. Trials of bioremediation were conducted in sand, rocks and granite tiles on the beach of Sorrizo (A Coruña, NW Spain) that was polluted by the spill. Neither the added microorganisms nor the nutrients significantly enhanced the degradation rate of the fuel oil in rocks, granite tiles or sand. PAH degradation up to 80% was determined in sand and tiles. In tiles the oxygen content of the residual oil increased from 1.6% up to 8% in 90 days, which could be explained by the accumulation of products coming from the partial oxidation of the hydrocarbons. Eighteen months after the spill, the rocks of the beach were still coated by a black layer of weathered fuel oil. For this reason an oleophilic product, sunflower biodiesel was tested on a rock. The application of biodiesel accelerated the gradually clean-up of the polluted surface and could also accelerate the degradation of the residual oil.

Coupled BAS and anoxic USB system to remove urea and formaldehyde from wastewater.

Wastewater containing formaldehyde and urea was treated using a coupled system consisting of a biofilm airlift suspension (BAS) reactor and an anoxic upflow sludge blanket (USB) reactor. The anoxic USB reactor was used to carry out denitrification and urea hydrolysis, while the BAS reactor was used to carry out nitrification. In a first step, individual experiments were carried out to investigate the effects of both compounds on the nitrifying and denitrifying biomass. The BAS reactor was fed with a synthetic medium containing 500 mg N-NH4(+)l(-1) and 100mg N-urea l(-1), that were added continuously to this medium. Neither urea hydrolysis nor inhibition of nitrification was observed. Nitrification efficiency decreased when formaldehyde was fed during shocks at concentrations of 40, 80 and 120 mg C-formaldehyde l(-1). The anoxic USB reactor was fed with a synthetic medium containing nitrate, formaldehyde and urea. Concentrations of formaldehyde in the reactor of 100-120 mg C-formaldehyde l(-1) caused a decrease in the denitrification and urea hydrolysis rates. In a second step, the coupled system was operated at recycling ratios (R) of 3 and 9. Fed C/N ratios of 0.58, 1.0 and 1.5 g C-formaldehyde g(-1) N-NH4(+) were used for every recycling ratio. The maximum nitrogen removal percentages were achieved at a C/N ratio of 1.0 g C-formaldehyde g(-1) N-NH4(+) for both recycling ratios. A fed C/N ratio of 1.5 g C-formaldehyde g(-1) N-NH4(+) caused a decrease in the efficiency of the system with respect to nitrogen removal, due to the presence of formaldehyde in the BAS reactor, which decreased the nitrification. Formaldehyde was completely removed in the BAS reactor and a heterotrophic layer formed around the nitrifying biofilm.

Oxidation of lignin in eucalyptus kraft pulp by manganese peroxidase from Bjerkandera sp. strain BOS55.

The white rot fungus Bjerkandera sp. strain BOS55 was shown in previous studies to cause high levels of kraft pulp bleaching and delignification under culture conditions in which manganese peroxidase (MnP) occurs as the dominant oxidative enzyme. In this study, the MnP of Bjerkadera was isolated and tested in vitro with eucalyptus oxygen-delignified kraft pulp (ODKP) based on measuring the reduction in kappa number as an indicator of lignin oxidation. The MnP preparation applied at 60 U/g pulp for 6 h caused a significant decrease of 11-13% in the kappa number in the ODKP under optimal conditions compared to parallel-incubated controls lacking enzyme. The effects of MnP dosage, Mn2+ concentration, organic acid buffer selection, pH and H2O2 addition were evaluated. The optimal Mn2+ concentration range for lignin oxidation in ODKP was 100-500 microM. In the presence of low oxalate concentrations (0.3-2 mM) the Bjerkandera MnP also significantly reduced the kappa number of ODKP by 6% without any Mn. This observation is in agreement with the fact that purified Bjerkandera MnP has Mn-independent activities. Under incubation conditions with added Mn2+, buffers composed of metal-complexing organic acids provided two-fold better kappa number reductions compared to the inert acetic acid. The optimal H2O2 dosage was found to be 0.017 micromol/min ml when added as semi-continuous pulses (every 30 min) or 0.2 micromol/min ml when generated continuously by glucose oxidase. Excess H2O2 caused severe inactivation of MnP during the incubations. Factors that improved the turnover of the enzyme, such as Mn2+ and metal-chelating acids, stabilized MnP against rapid inactivation.

Simultaneous urea hydrolysis, formaldehyde removal and denitrification in a multifed upflow filter under anoxic and anaerobic conditions.

A multifed upflow filter (MUF), working under anoxic or anaerobic conditions, coupled with an aerobic biofilm airlift suspension (BAS) reactor was operated in order to treat a wastewater with high formaldehyde (up to 1.5 g L-1) and urea (up to 0.46 g L-1) concentrations. In the MUF, formaldehyde removal, denitrification and urea hydrolysis took place simultaneously. The MUF was operated at 37 degrees C, at a hydraulic retention time (HRT) ranging from 1 to 0.3 d. An organic loading rate (OLR) of 0.5 kg-formaldehyde m-3 d-1 was efficiently eliminated during anaerobic operation and transformed into methane, while a much higher OLR (up to 2 kg-formaldehyde m-3 d-1) was oxidised under anoxic conditions by the nitrite or nitrate from the nitrifying airlift. However, only 80% of urea was hydrolysed to ammonia in an anoxic environment while complete conversion occurred under anaerobic conditions. Moreover, formaldehyde concentrations higher than 50 mg L-1 provoked a loss of efficiency of urea hydrolysis, decreasing to 10% at formaldehyde concentrations above 300 mg L-1. Methane production rate during the anaerobic stage was adversely affected by accumulations of formaldehyde in the reactor causing lower formaldehyde removal efficiency. However, denitrification proceeded properly even at a formaldehyde concentration of 700 mg L-1 in the reactor, although nitrous oxide appears in the off-gas. The COD/N ratios required for complete nitrite and nitrate denitrification with formaldehyde were estimated at 2.1 and 3.5 kg-COD/kg-N, respectively.

Evaluation of extracts from Gevuina avellana hulls as antioxidants.

The antioxidant activity of the extracts from Gevuina avellana hulls was evaluated and compared with that of BHT (butylated hydroxytoluene) and BHA (butylated hydroxyanisole), using the beta-carotene bleaching assay, the accelerated oxidation of crude soybean oil, and the 2,2-diphenyl-beta-picrylhydrazyl (DPPH) radical scavenging method. Solvents of different polarity were used to obtain the extracts. Both the extraction yield and the antioxidant activity were strongly dependent on the solvent. The ethanol and diethyl ether soluble fractions were the most active with the beta-carotene assay. Ethanol and methanol extracts were the most active in hydrogen radical scavenging activity. Water and methanol inhibited more efficiently the oxidation of soybean oil at 70 and 80 degrees C, respectively. As a general trend, increased antioxidant activity was observed for increased extract concentration. Except the acetone extracts, all were stable after 6 months storage at 4 degrees C. The ethanol solubles from G. avellana hulls present antioxidant activity similar to that of synthetic antioxidants and to other reported residual agroindustrial materials.

Different fungal manganese-oxidizing peroxidases: a comparison between Bjerkandera sp. and Phanerochaete chrysosporium.

Two manganese-oxidizing peroxidases differing in glycosylation degree were purified from fermenter cultures of Bjerkandera sp. They were characterized and compared with the three manganese-oxidizing peroxidase isoenzymes obtained from the well-known ligninolytic fungus Phanerochaete chrysosporium. All the enzymes showed similar molecular masses but those from P. chrysosporium had less acidic isoelectric point. Moreover, the latter strictly required Mn2+ to oxidize phenolic substrates whereas the Bjerkandera peroxidases had both Mn-mediated and Mn-independent activity on phenolic and non-phenolic aromatic substrates. Taking into account these results, and those reported for Bjerkandera adusta and different Pleurotus species, we concluded that two different types of Mn(2+)-oxidizing peroxidases are secreted by ligninolytic fungi.