Acanthamoeba in the eye, can the parasite hide even more? Latest developments on the disease.

Acanthamoeba spp. is a free living protozoan in the environment, but can cause serious diseases. Acanthamoeba keratitis (AK), a severe and painful eye infection, must be treated as soon as possible to prevent ulceration of the cornea, loss of visual acuity, and eventually blindness or enucleation. Although the disease affects principally contact lens (CLs) wearers, it is recognized nowadays as a cause of keratitis also in non-CLs wearers. Although the number of infections caused by these amoebae is low, AK is an emerging disease presenting an extended number of cases each year worldwide mostly due to the increasing use of CLs, but also to better diagnostic methods and awareness. There are two principal causes that lead to severe outcomes: misdiagnosis or late diagnosis of the causal agent, and lack of a fully effective therapy due to the existence of a highly resistant cyst stage of Acanthamoeba. Recent studies have reported different genotypes that have not been previously associated with this disease. In addition, Acanthamoeba can act as a reservoir for phylogenetically diverse microorganisms. In this regard, recently giant viruses called Pandoravirus have been found within genotypes producing keratitis. What potential risk this poses is not yet known. This review focuses on an overview of the present status and future prospects of this re-emerging pathology, including features of the parasite, epidemiology, clinical aspects, diagnosis, and treatment.

Pyrolysis-gas chromatography-isotope ratio mass spectrometry for monitoring natural additives in polylactic acid active food packages.

Compound-specific isotope analysis (CSIA) usually requires preparative steps (pretreatments, extraction, derivatization) to get amenable chromatographic analytes from bulk geological, biological or synthetic materials. Analytical pyrolysis (Py-GC/MS) can help to overcome such sample manipulation. This communication describe the results obtained by hyphenating analytical pyrolysis (Py-GC) with carbon isotope-ratio mass spectrometry (IRMS) for the analysis of a polylactic acid (PLA) a based bio-plastic extruded with variable quantities of a natural plant extract or oregano essential oil. The chemical structural information of pyrolysates was first determined by conventional analytical pyrolysis and the measure of δ13C in specific compounds was done by coupling a pyrolysis unit to a gas chromatograph connected to a continuous flow IRMS unit (Py-GC-C-IRMS). Using this Py-CSIA device it was possible to trace natural additives with depleted δ13C values produced by C3 photosystem vegetation (cymene: -26.7‰±2.52; terpinene: -27.1‰±0.13 and carvacrol: -27.5‰±1.80 from oregano and two unknown structures: -23.3‰±3.32 and -24.4‰±1.70 and butyl valerate: -24.1‰±3.55 from Allium spp.), within the naturally isotopically enriched bio-plastic backbone derived from corn (C4 vegetation) starch (cyclopentanones: -14.2‰±2.11; lactide enantiomers: -9.2‰±1.56 and larger polymeric units: -17.2‰±1.71). This is the first application of Py-CSIA to characterize a bio-plastic and is shown as a promising tool to study such materials, providing not only a fingerprinting, but also valuable information about the origin of the materials, allowing the traceability of additives and minimizing sample preparation.

Microwave-induced cracking of pyrolytic tars coupled to microwave pyrolysis for syngas production.

Herein a new process is proposed to produce a syngas-rich gas fraction (>80vol% H2+CO) from biowaste based on microwave heating within two differentiated steps in order to avoid tars production. The first step consists of the microwave pyrolysis of biowaste induced by a char-based susceptor at 400-800°C; tars, char and syngas-rich gas fractions being produced. The tars are then fed into the second step where a portion of the char from the first step is used as a bed material in a 0.3:1wt% ratio. This bed is heated up by microwaves up to 800°C, allowing thermal cracking of tars and additional syngas (>90vol% H2+CO) being then produced. This new concept arises as an alternative technology to the gasification of biowastes for producing syngas with no need for catalysts or gasifying reagents to minimise tars production.

Development of PLA films containing oregano essential oil (Origanum vulgare L. virens) intended for use in food packaging.

Consumers' concerns about the environment and health have led to the development of new food packaging materials avoiding petroleum-based matrices and synthetic additives. The present study has developed polylactic acid (PLA) films containing different concentrations of essential oil from Origanum vulgare L. virens (OEO). The effectiveness of this new active packaging was checked for use in ready-to-eat salads. A plasticising effect was observed when OEO was incorporated in PLA films. The rest of the mechanical and physical properties of developed films did not show much change when OEO was included in the film. An antioxidant effect was recorded only for films containing the highest percentages of the active agent (5% and 10%). In addition, films exhibited in vitro antibacterial activity against Staphylococcus aureus, Yersinia enterocolitica, Listeria monocytogenes, Enterococcus faecalis and Staphylococcus carnosus. Moreover, in ready-to-eat salads, antimicrobial activity was only observed against yeast and moulds, where 5% and 10% of OEO was the most effective.

Development of a mechanism and an accurate and simple mathematical model for the description of drug release: Application to a relevant example of acetazolamide-controlled release from a bio-inspired elastin-based hydrogel.

Transversality between mathematical modeling, pharmacology, and materials science is essential in order to achieve controlled-release systems with advanced properties. In this regard, the area of biomaterials provides a platform for the development of depots that are able to achieve controlled release of a drug, whereas pharmacology strives to find new therapeutic molecules and mathematical models have a connecting function, providing a rational understanding by modeling the parameters that influence the release observed. Herein we present a mechanism which, based on reasonable assumptions, explains the experimental data obtained very well. In addition, we have developed a simple and accurate "lumped" kinetics model to correctly fit the experimentally observed drug-release behavior. This lumped model allows us to have simple analytic solutions for the mass and rate of drug release as a function of time without limitations of time or mass of drug released, which represents an important step-forward in the area of in vitro drug delivery when compared to the current state of the art in mathematical modeling. As an example, we applied the mechanism and model to the release data for acetazolamide from a recombinant polymer. Both materials were selected because of a need to develop a suitable ophthalmic formulation for the treatment of glaucoma. The in vitro release model proposed herein provides a valuable predictive tool for ensuring product performance and batch-to-batch reproducibility, thus paving the way for the development of further pharmaceutical devices.

Challenges and opportunities in polymer technology applied to veterinary medicine.

An important frontier in the administration of therapeutic drugs to veterinary species is the use of different polymers as drug delivery platforms. The usefulness of polymers as platforms for the administration of pharmaceutical and agricultural agents has been clearly recognized in the recent decades. The chemical versatility of polymers and the wide range of developed controlled-release strategies enhance the possibilities for the formulation of active molecules. In particular, the veterinary area offers opportunities for the development of novel controlled-release drug delivery technologies adapted to livestock or companion animal health needs. In some cases, it also allows to improve profitability in meat production or to meet the safety criteria related to drug residues. A number of factors affect the selection of polymers and subsequent properties of the controlled-release drug delivery system. However, their selection also dictates the release kinetics of the drug from the delivery system. Such choices are therefore crucial as they affect the success and potential of the delivery system for achieving the therapeutic goals of the veterinarian. It is the intention of this review to give an overview of the most relevant polymers, which are used or have been tested as drug delivery release rate modifiers in the veterinary field. The article highlights some recent developments focusing on their advantages and applications and analyzes the future direction of the scientific and technological advancements in this area.

Conventional and microwave pyrolysis of a macroalgae waste from the Agar-Agar industry. Prospects for bio-fuel production.

A comparative study of the pyrolysis of a macroalgae industrial solid waste (algae meal) in an electrical conventional furnace and in a microwave furnace has been carried out. It was found that the chars obtained from both pyrolyses are similar and show good properties for performing as a solid bio-fuel and as a precursor of activated carbon. Bio-oils from conventional pyrolysis have a greater number of phenolic, pyrrole and alkane compounds whereas benzene and pyridine compounds are more predominant in microwave pyrolysis with a major presence of light compounds. The bio-gas fraction from microwave pyrolysis presents a much higher syngas content (H2+CO), and a lower CO2 and CH4 proportion than that obtained by conventional pyrolysis. Yields are similar for both treatments with a slightly higher gas yield in the case of microwave pyrolysis due to the fact that microwave heating favors heterogeneous reactions between the gases and the char.

[Renal cell carcinoma producing erythrocytosis due to inappropriate production of erythropoietin]. / Eritrocitosis secundaria a la producción inapropiada de eritropoyetina por un carcinoma de células renales.

Erythrocytosis, or polycythaemia, is an increase, in absolute terms, of the erythrocyte mass. The most common solid tumour related to this phenomenon is renal cell carcinoma, which can produce erythrocytosis by increasing erythropoietin production. About 30% of symptomatic renal cell carcinomas are diagnosed due to the appearance of a paraneoplastic syndrome. Polycythaemia is one of these. Surgery, (radical or partial nephrectomy), is the treatment of choice in renal cell carcinoma and helps to keep the erythrocytosis situation under control.

Microwave pyrolysis of microalgae for high syngas production.

The microwave induced pyrolysis of the microalgae Scenedesmus almeriensis and its extraction residue was carried out at 400 and 800°C. The results show that it is possible to obtain a gas fraction with a high content (c.a. 50vol.%) in H2 from both materials, regardless of the pyrolysis temperature. Furthermore, an outstanding syngas production and high gas yields were achieved. The maximum syngas concentration obtained was c.a. 94 vol.%, in the case of the pyrolysis of the residue at 800°C, indicating that the production of CO2 and light hydrocarbons was minimized. The same experiments were carried out in a conventional electric furnace in order to compare the products and yields obtained. It was found that microwave induced pyrolysis gives rise not only to higher gas yields but also to greater syngas and H2 production.

Meduloblastoma congénito gigante de presentación y localización atípicas / Congenital giant medulloblastoma with atypical presentation and location

El meduloblastoma congénito es uno de los tumores intracraneales más frecuentes en la edad pediátrica; sin embargo, su presentación es poco frecuente antes de los 2 meses de vida. Presentamos el caso deun recién nacido con un meduloblastoma congénito gigante, con sintomatología en el periodo neonatal inmediato y de localización atípica. Este tipo de tumor debe ser tenido en consideración al realizar el diagnóstico diferencial de la hidrocefalia congénita (AU)

Congenital medulloblastoma is one of the most frequent pediatric intracranial tumors, however, it is unusual its presentation before the two months of life. We are presenting the case of a new-born infant with a giant congenital medulloblastoma, with symptoms in the immediate neonatal period and atypical location. This kind of tumor must be taken on account when making a differential diagnosis of congenital ventricular hydrocephalus (AU)

Low temperature regeneration of activated carbons using microwaves: revising conventional wisdom.

The purpose of this work was to explore the application of microwaves for the low temperature regeneration of activated carbons saturated with a pharmaceutical compound (promethazine). Contrary to expectations, microwave-assisted regeneration did not lead to better results than those obtained under conventional electric heating. At low temperatures the regeneration was incomplete either under microwave and conventional heating, being this attributed to the insufficient input energy. At mild temperatures, a fall in the adsorption capacity upon cycling was obtained in both devices, although this was much more pronounced for the microwave. These results contrast with previous studies on the benefits of microwaves for the regeneration of carbon materials. The fall in the adsorption capacity after regeneration was due to the thermal cracking of the adsorbed molecules inside the carbon porous network, although this effect applies to both devices. When microwaves are used, along with the thermal heating of the carbon bed, a fraction of the microwave energy seemed to be directly used in the decomposition of promethazine through the excitation of the molecular bonds by microwaves (microwave-lysis). These results point out that the nature of the adsorbate and its ability to interact with microwave are key factors that control the application of microwaves for regeneration of exhausted activated carbons.

¿Mejora el aporte proteico precoz el crecimiento extrauterino en recién nacidos pretérmino de bajo peso? / Does early parenteral protein intake improve extrauterine growth in low birth weight preterms?

Introducción: El retraso de crecimiento postnatal es frecuente en los recién nacidos pretérmino (RNPT) de bajo peso. La administración precoz de proteínas en su nutrición parece mejorar el crecimiento extrauterino y las comorbilidades asociadas. Evaluamos el impacto sobre el crecimiento posnatal de un nuevo protocolo de nutrición parenteral con aporte precoz de aminoácidos en recién nacidos < 1.500g. Material y métodos: Estudio observacional de casos-controles sobre una muestra de 58 RNPT < 1.500g. El grupo de casos lo formaron 29 RNPT que recibieron al menos 1,5g/kg/día de aminoácidos vía parenteral en las primeras 24h de vida, con aumentos diarios hasta alcanzar al menos 3,5g/kg/día al 3.°-4.° día, comparándose con un grupo control de 29 RNPT en los que el aporte de aminoácidos se inició el 2.°-3.° día de vida a 1g/kg/día, con incrementos menores diariamente. Valoramos la evolución somatométrica de ambos en el primer mes de vida. Resultados: No había diferencias en las características basales (sexo, edad gestacional, parámetros somatométricos) entre ambos grupos. Los RNPT que recibieron proteínas a dosis mayores y más precozmente tuvieron una ganancia de peso significativamente mayor que el grupo control (423±138g vs. 315±142g; p=0,005), presentando también una mayor velocidad de ganancia ponderal diaria (19,4±3,3 vs. 16,5±4,8; p=0,010) y una recuperación más precoz del peso al nacimiento (11,5±3,3 días vs. 14,5±4,5 días; p=0,045). No se observó mayor incidencia de complicaciones. Conclusiones: El aporte precoz de aminoácidos a dosis más altas mejora la ganancia ponderal en RNPT sin observarse un riesgo añadido para el paciente(AU)

Introduction: Extrauterine growth restriction affects most premature newborns. Early and higher parenteral protein intake seems to improve postnatal growth and associated comorbidities. We evaluate the impact of a new parenteral nutrition protocol based on early amino acid administration on postnatal growth in premature infants with a birth weight < 1,500 grams. Material and methods: A case-control study in 58 premature newborns with a birth weight < 1,500 grams. In the case group we included 29 preterm neonates who received at least 1.5g/kg/day parenteral amino acid during the first 24hours after birth, reaching a maximum dose of 3.5g/kg/day on the 3rd-4th day after birth. The control group was formed by 29 preterm neonates for whom protein support began on the 2nd-3rd day after birth with a dose of 1g/kg/day with lower daily increases than the case group. Growth rates and complications were followed until 28 days of life or discharge from NICU. Results: There were no differences between groups in baseline characteristics. Premature newborns who received higher and earlier doses of proteins had a greater weight gain than the control group, and this difference was statistically significant (423±138g vs. 315±142g; P=.005). In addition, they had a higher daily weight gain rate (19.4±3.3 vs. 16.5±4.8; P=.010) and they regained birth weight earlier (11.5±3.3 days vs. 14.5±4.5 days; P=.045). A higher incidence of complications was not observed. Conclusions: Early and higher amino acid administration improves growth rate in premature neonates with no apparent increase in risks for the patient(AU)

[Does early parenteral protein intake improve extrauterine growth in low birth weight preterms?]. / ¿Mejora el aporte proteico precoz el crecimiento extrauterino en recién nacidos pretérmino de bajo peso?

INTRODUCTION: Extrauterine growth restriction affects most premature newborns. Early and higher parenteral protein intake seems to improve postnatal growth and associated comorbidities. We evaluate the impact of a new parenteral nutrition protocol based on early amino acid administration on postnatal growth in premature infants with a birth weight < 1,500 grams. MATERIAL AND METHODS: A case-control study in 58 premature newborns with a birth weight < 1,500 grams. In the case group we included 29 preterm neonates who received at least 1.5 g/kg/day parenteral amino acid during the first 24 hours after birth, reaching a maximum dose of 3.5 g/kg/day on the 3(rd)-4(th) day after birth. The control group was formed by 29 preterm neonates for whom protein support began on the 2(nd-)3(rd) day after birth with a dose of 1g/kg/day with lower daily increases than the case group. Growth rates and complications were followed until 28 days of life or discharge from NICU. RESULTS: There were no differences between groups in baseline characteristics. Premature newborns who received higher and earlier doses of proteins had a greater weight gain than the control group, and this difference was statistically significant (423 ± 138 g vs. 315 ± 142 g; P=.005). In addition, they had a higher daily weight gain rate (19.4 ± 3.3 vs. 16.5 ± 4.8; P=.010) and they regained birth weight earlier (11.5 ± 3.3 days vs. 14.5 ± 4.5 days; P=.045). A higher incidence of complications was not observed. CONCLUSIONS: Early and higher amino acid administration improves growth rate in premature neonates with no apparent increase in risks for the patient.

Serum levels of IGF1 are a useful predictor of retinopathy of prematurity.

OBJECTIVE: To ascertain whether insulin-like growth factor 1 (IGF1) is associated with retinopathy of prematurity (ROP) and is a useful predictor of the disease. Although its aetiopathogenesis is multifactorial, development of the disease appears to be related to a deficiency in IGF1, a hormone that acts together with vascular endothelial growth factor in the normal angiogenesis in the retina. DESIGN: Prospective study for a 30-month period. PARTICIPANTS: A total of 74 premature newborn babies, of less than 1500 g and/or 32 weeks' gestational age or less. TESTING: To determine the development and severity of ROP. MAIN OUTCOME MEASURES: Serum levels of IGF1 were measured once a week from birth until 40 weeks corrected gestational age in each subject. RESULTS: Of our subjects, 32.4% developed some form of ROP, and all those ROP patients had the following characteristics at birth (median +/- standard deviation scores): low weight (1098 +/- 188 vs. 1393 +/- 285 g), short length (36.74 +/- 1.77 vs. 38.89 +/- 3.08 cm), small cranial perimeter (26.03 +/- 1.74 vs. 27.93 +/- 1.81 cm) and young gestational age (29.7 +/- 1.78 vs. 31.3 +/- 1.79 weeks) (p < 0.05). Other factors previously associated with ROP that were also observed with statistically significant frequency in our ROP patients were bronchopulmonary dysplasia, intracranial haemorrhage, the need for erythrocyte transfusion or treatment with erythropoietin and sepsis (all p < 0.05). Levels of IGF1 at the 3rd week post-partum, independent of gestational age at birth, were clearly lower in the group who developed ROP (29.13 vs. 43.16 ng/mL, p < 0.05). A value of 30 ng/mL of IGF1 in the third week post-partum was found to have a 90% sensitivity in the diagnosis of ROP. A rapid rise in IGF1 levels between the 3rd and 5th weeks appeared to be related to the development of a higher stage of ROP. CONCLUSION: Determination of IGF1 serum levels in the 3rd week post-partum, independent of gestational age at birth, provides a sufficient and reliable prognostic tool and allows the identification of a group of patients at high risk of developing the disease.

[Advances in the diagnosis and treatment of maple syrup urine disease: experience in Galicia (Spain)]. / Avances en el diagnóstico y tratamiento de la enfermedad de jarabe de arce, experiencia en Galicia.

INTRODUCTION: Maple syrup urine disease (MSUD) is a rare autosomal recessive disorder caused by an inherited deficiency of branched chain alpha-ketoacid dehydrogenase activity. Accumulation of the amino acids leucine, isoleucine, valine and alloisoleucine and their metabolic products in cells and biological fluids results in severe brain dysfunction. PATIENTS AND METHODS: We present three cases of MSUD diagnosed in Galicia since 2000, the year in which the Extended Newborn Screening Program by tandem mass spectrometry was started in this region. One of the patients was diagnosed on the basis of early clinical presentation and the others by neonatal screening. Enzymatic and molecular studies confirmed two classic cases of MSUD and an intermediate variant. We describe the clinical and biochemical details at confirmation of diagnosis and the long-term outcome of the three patients. Throughout follow-up, all the patients maintained adequate leucine levels, which were near the normal range (mean levels: 220, 177 and 252 micromol/L, respectively). Several moderate metabolic decompensations were observed but leucine levels only occasionally exceeded 1000 micromol/L (one day in two patients). IQ tests were performed in all patients and scores were within the normal range. In view of our results, we believe the following measures are essential to improve the prognosis of MSUD: inclusion of this disease in Expanded Neonatal Screening Programs with early samples (at 2-3 days of life); aggressive treatment in the initial phase and during acute decompensations; strict metabolic control to prevent crises, monitoring of branched-chain amino acids (dried blood spot sample), and maintenance of long term plasma leucine levels below 300 micromol/L.

Avances en el diagnóstico y terapéutica de los niños con tirosinemia tipo I / Advances in the diagnosis and treatment of children with tyrosinemia type I

La tirosinemia Tipo I es un error genético del metabolismode la tirosina producido por un déficit deFumarilacetoacetato Hidrosilasa (FAH), último enzimaen la vía de degradación de la tirosina, que dalugar al acúmulo de metabolitos intermediarios maleily fumaril-acetoacetato produciendo toxicidad hepáticay renal, y el metabolito secundario succinilacetona,produciendo efectos sistémicos y locales.Se suele presentar como hepatopatía aguda o crónicay/o carcinoma hepatocelular, disfunción tubularrenal o manifestaciones neurológicas. Como alternativasterapéuticas en el momento actual destacarel tratamiento dietético, la terapia con NTBC (2-(2-Nitro-4-trifluorometilbenzoil) 1-3-ciclohexanodiona) yel trasplante hepático. Este último se reserva básicamentepara pacientes con mala respuesta alNTBC, riesgo de malignidad y/o mala calidad de vidacon las otras alternativas terapéuticas. Presentamos3 casos de pacientes que han recibido NTBCde forma precoz con muy buena respuesta clínica ybioquímica, como muestra del importante cambioque se ha producido en los últimos años en esta enfermedad,lo que conlleva a grandes mejoras tantoen la calidad de vida como en su pronóstico

Tyrosinemia type I is a inborn error of tyrosinemetabolism caused by a deficiency of fumarylacetoacetase(FAH), the last enzyme in the tyrosine catabolicpathway; as a result, the reactive compoundsmaleylacetoacetate and fumarylacetoacetate are formed,which are thought to be responsable for the liverand kidney injury, and the secondary metabolitesuccunylacetone, with regional and general injurys.Clinically the disorder is characterised by progressiveacute or chronic liver damage and/or hepatocellularcarcinoma, renal tubular dysfunction or neurologicalcrises. The current therapy includes dietaryrestriction, NTBC (2-(2-nitro-4-trifluoromethyl benzoyl)-1-3-cyclohexanedione) therapy and liver transplantation.The indications for liver transplantationinclude non-response to NTBC, risk of malignancyand poor quality of live related to the other therapies.Here we report 3 patients early managed with NTBCresulting in clinical and biochemical improvement, toshow the important changes in the managenent ofthe disease in the last years, with better quality of lifeand pronostic as a result

Silicon determination in milk by electrothermal atomic absorption spectrometry using palladium as chemical modifier.

A direct method for silicon determination in milk samples by Electrothermal Atomic Absorption Spectrometry was developed. Palladium was used as chemical modifier at a concentration of 610 mg L(-1); with this modifier, silicon was stable up to 1800 degrees C. The precision and accuracy of the method were investigated. The detection limit was 16.2, 2.7 and 7.2 micro g L(-1) for cows' milk, human milk and infant formula, respectively. The method was applied to silicon determination in 17 infant formula samples, 13 human milk samples and 12 cows' milk samples.

Infección del tracto urinario: estudio prospectivo clínico y analítico para el diagnóstico diferencial en niños con sospecha de enfermedad infecciosa / Urinary tract infection in children: clinical and analytical prospective study for differential diagnosis in children with suspicion of an infectious disease

Objetivo: examinar las diferencias, en la clínica y en la analítica de sangre y orina, en los pacientes que acuden a urgencias de pediatría de un hospital de III nivel que permitan distinguir a aquellos que tienen infección del tracto urinario (ITU) de los que presentan otros procesos infecciosos o febriles. Con este fin, se hace un examen comparativo de los datos clínicos, sanguíneos, y análisis de orina entre dos grupos de pacientes, con y sin ITU, atendidos consecutivamente en urgencias. Pacientes y Métodos: durante un periodo de 6 meses, fueron evaluados prospectivamente 349 niños con edades comprendidas entre menos de 1 mes y los 14 años (media: 4,1 años), de entre los 14.400 atendidos en urgencias y que presentaban fiebre > 38,1° C y/o otros signos o síntomas relacionados con una ITU. En 247 pacientes, la ITU fue descartada. A los restantes 102 se les practicó un urocultivo y fueron divididos en dos grupos según el resultado del mismo, con y sin ITU; analizándose las diferencias entre los datos clínicos, exámenes de orina y análisis de sangre. Resultados: la sospecha de ITU en los 14.400 pacientes atendidos en urgencias, se planteó en 349 casos (2,4 por ciento), con una prevalencia de ITU en el conjunto de pacientes con sospecha de tener infección del 12,3 por ciento. La incidencia global de ITU en la población pediátrica que acudió a urgencias fue del 0,3 por ciento. Los 59 pacientes del grupo con urocultivo negativo, mostraron un porcentaje más alto de signos clínicos inespecíficos y examen microscópico de orina normal (p < 0,05), que los 43 pacientes del grupo con urocultivo positivo (ITU confirmada). El multistix de orina anormal, se obtuvo en mayor porcentaje (p < 0,05), en los pacientes con ITU. No se hallaron diferencias relevantes en otros parámetros clínicos y análisis de sangre entre ambos grupos. Fue necesario hospitalizar, basándose en la gravedad de los signos clínicos, en una proporción más elevada a los pacientes con ITU (27,9 por ciento vs 1,7 por ciento) y a los menores de 6 meses con ITU (66,6 por ciento). Conclusiones: el multistix y el examen microscópico anormal de orina en los pacientes con ITU, y los signos clínicos inespecíficos en los que no la tienen, poseen valor discriminativo en el diagnóstico diferencial. Se observa un gran solapamiento entre los signos clínicos y los análisis de sangre entre los pacientes que acuden a urgencias con infecciones varias y los que padecen una ITU. Estos parámetros, no son de utilidad significativa en el diagnóstico diferencial. Los multistix son útiles para el cribado en los casos sospechosos de ITU, si se conocen bien sus limitaciones. Es imprescindible obtener una muestra limpia de orina con cultivo positivo, para el diagnóstico de infección urinaria verdadera (AU)

Selenium determination in mother and child's hair by electrothermal atomic absorption spectrometry.

A method for the selenium determination in a mother and her child's hair using palladium as a chemical modifier was optimized. The sample was digested with nitric acid and hydrogen peroxide and diluted to 5 ml. To achieve complete mineralization the samples were ashed at 1200 degrees C in the presence of palladium as a chemical modifier. The optimum atomization temperature was 1900 degrees C. The precision and accuracy of the method were studied using the reference material CRM 397. Results of calibration using aqueous standards and the standard addition method were compared. The method was applied to the selenium determination in 30 samples of the mother's and child's hair. The levels found were 0.54 +/- 0.34 microgram/g for mother's hair and 0.77 +/- 0.25 microgram/g for child's hair.