Cell-free supernatant of probiotic bacteria exerted antibiofilm and antibacterial activities against Pseudomonas aeruginosa: A novel biotic therapy.

Aim: This study aims to verify the antibacterial and antibiofilm action of cell-free spent medium (CFSM) from four lactic acid bacteria with potential probiotic characteristics (Lactiplantibacillus plantarum, Lactobacillus acidophilus, Lactobacillus johnsonii, and Lactobacillus delbrueckii) against two Pseudomonas aeruginosa strains. Main methods: The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the CFSM, antibacterial activity by analysing the formation of inhibition zones, and inhibition of planktonic cultures were determined. Whether an increase in the concentration of CFSM influenced the growth of pathogenic strains and the anti-adhesive activity of the CFSM in biofilm formation (crystal violet and MTT assays) were determined, which were all corroborated by using scanning electron microscopy. Key findings: The relationship between the MIC and MBC values showed a bactericidal or bacteriostatic effect for all the cell-free spent media (CFSMs) tested for P. aeruginosa 9027™ and 27853™ strains. The CFSM supplemental doses of 18 or 22%, 20 or 22%, 46 or 48%, and 50 or 54% of L. acidophilus, L. delbrueckii, L. plantarum, and L. johnsonii, respectively, could completely inhibit the growth of both pathogen strains. The antibiofilm activity of the CFSM in three biofilm conditions (pre-coated, co-incubated, and preformed) demonstrated values ranging between 40% and 80% for biofilm inhibition, and similar results were observed for cell viability. Significance: This work provides strong evidence that the postbiotic derived from different Lactobacilli could be practical as an adjuvant therapy for reducing the use of antibiotics, being a good candidate to overcome the growing challenge of hospital infections due to this pathogen.

Synthesis, physicochemical characterisation and biological activity of anandamide/ɛ-polycaprolactone nanoparticles obtained by electrospraying.

Drug encapsulation in nanocarriers such as polymeric nanoparticles (Nps) may help to overcome the limitations associated with cannabinoids. In this study, the authors' work aimed to highlight the use of electrospraying techniques for the development of carrier Nps of anandamide (AEA), an endocannabinoid with attractive pharmacological effects but underestimated due to its unfavourable physicochemical and pharmacokinetic properties added to its undesirable effects at the level of the central nervous system. The authors characterised physicochemically and evaluated in vitro biological activity of anandamide/ɛ-polycaprolactone nanoparticles (Nps-AEA/PCL) obtained by electrospraying in epithelial cells of the human proximal tubule (HK2), to prove the utility of this method and to validate the biological effect of Nps-AEA/PCL. They obtained particles from 100 to 900 nm of diameter with a predominance of 200-400 nm. Their zeta potential was -20 ± 1.86 mV. They demonstrated the stable encapsulation of AEA in Nps-AEA/PCL, as well as its dose-dependent capacity to induce the expression of iNOS and NO levels and to decrease the Na+/K+ ATPase activity in HK2 cells. Obtaining Nps-AEA/PCL by electrospraying would represent a promising methodology for a novel AEA pharmaceutical formulation development with optimal physicochemical properties, physical stability and biological activity on HK2 cells.

Current Drug Nano-targeting Strategies for Improvement in the Diagnosis and Treatment of Prevalent Pathologies such as Cardiovascular and Renal Diseases.

BACKGROUND: The kidney and cardiovascular system are closely related to each other during the modulation of the cardiovascular homeostasis. However, the search for new alternatives for the treatment and diagnosis of cardiovascular diseases does not take into account this relationship, so their evaluation results and the advantages offered by their global and integrative analysis are wasted. For example, a variety of receptors that are overexpressed in both pathologies is large enough to allow expansion in the search for new molecular targets and ligands. Nanotechnology offers pharmacological targeting strategies to kidney, heart, and blood vessels for overcoming one of the essential restrictions of traditional cardiovascular therapies the ones related to their unspecific pharmacodynamics distribution in these critical organs. RECENT FINDINGS: Drug or contrast agent nano-targeting for treatment or diagnosis of atherosclerosis, thrombosis, renal cancer or fibrosis, glomerulonephritis, among other renal, cardiac and blood vessels pathologies would allow an increase in their efficacy and a reduction of their side effects. Such effects are possible because, through pharmacological targeting, the drug is mainly found at the desired site. Review Purpose: In this mini-review, active, passive, and physical targeting strategies of several nanocarriers that have been assessed and proposed for the treatment and diagnosis of different cardiovascular diseases, are being addressed.

Anandamide-nanoformulation obtained by electrospraying for cardiovascular therapy.

Anandamide (AEA), an endogenous cannabinoid, has a relevant antihypertensive effect. However, its cardioprotective role has been barely explored due to unfavorable physico-chemical properties and, sometimes, undesirable psychoactive effects. In this context, drug encapsulation in nanocarriers could overcome the limitations associated with the administration of AEA in free form. The aim of the present study was to encapsulate AEA in poly-ε-caprolactone/Pluronic® F127 nanoparticles (AEA/PCL/PF127 NPs) by means of electrospraying, to characterize their physico-chemical properties and cytocompatibility and to evaluate their effect in an in vivo model of cardiovascular remodeling caused by hypertension. AEA/PCL/PF127 NPs were characterized in terms of morphology, size, polydispersity, Z-potential, hydrophilicity, thermal and spectroscopic properties. Also, the encapsulation and loading efficiencies and in vitro release of AEA were analyzed. AEA/PCL/PF127 NPs (700-1000 nm) showed adequate cytocompatibility. For the cardiovascular remodeling studies, normotensive (WKY) and hypertensive (SHR) male rats were treated or not with AEA/PCL/PF127 NPs (5 mg/Kg, intraperitoneal injection) weekly for 1 month. Inflammatory markers and hemodynamic, structural and cardiac functional parameters were monitored. In SHR, the treatment with AEA/PCL/PF127 NPs reversed all altered cardiovascular markers and parameters (p < 0.05). Overall, nanoformulated AEA obtained by electrospraying proved to be effective for the treatment of hypertension and its comorbidities, especially cardiovascular remodeling.

Preparation and characterization of bosentan monohydrate/ε-polycaprolactone nanoparticles obtained by electrospraying.

The electrospraying technique provides nano and microparticles that can be used as drug delivery systems. The aims of this study were, firstly, to optimize the influent parameters of electrospraying for the manufacture of a Bosentan (BOS) nanoparticulate platform, and secondly, to evaluate its physicochemical properties and in vitro biopharmaceutical behavior. Particles were characterized by scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), thermogravimetry (TG) and Fourier transformed Infrared spectroscopy (FTIR). Drug loading, encapsulation efficiency and kinetic dissolution were determined. Additionally, Bosentan release assays at 24 and 72 h were performed in vitro to evaluate biopharmaceutical properties of nano-scaffolds by diffusion technique through dialysis bag. The nanostructures had heterogeneous sizes predominantly smaller than 550 nm and they were semicrystalline according to PXRD, indicating a partial amorphization of BOS during the encapsulation in the polymer matrix. FT-IR and DSC showed an absence of chemical interactions between BOS and ε-Polycaprolactone (PCL), suggesting that both components behaved as a physical mixture in these particles. The drug loading was 25.98%, and the encapsulation efficiency was 58.51%. Additionally, the release assays showed an extended and controlled release of BOS, in comparison to non-encapsulated BOS. These data also showed to fit with the Cubic Root kinetic dissolution. As a conclusion, we demonstrate that the use of electrospraying for the manufacture of BOS (or similar drugs) controlled release nanoplatforms would represent an interesting contribution in the development of new therapeutic alternatives for the treatment of pathologies such as pulmonary hypertension and other related diseases. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 35: e2748, 2019.

Anandamide and endocannabinoid system: an attractive therapeutic approach for cardiovascular disease.

Cardiovascular disease is currently not adequately managed and has become one of the main causes of morbidity and mortality worldwide. Current therapies are inadequate in terms of preventing its progression. There are several limitations, such as poor oral bioavailability, side effects, low adherence to treatment, and high dosage frequency of formulations due to the short half-life of the active ingredients used, among others. This review aims to highlight the most relevant aspects of the relationship between the cardiovascular system and the endocannabinoid system, with special attention to the possible translational effect of the use of anandamide in cardiovascular health. The deep and detailed knowledge of this interaction, not always beneficial, and that for years has gone unnoticed, is essential for the development of new therapies. We discuss the most recent and representative results obtained in the field of basic research, referring to the aforementioned subject, emphasizing fundamentally the main role of nitric oxide, renal physiology and its deregulation in pathological processes.

Nanotechnological Strategies as Smart ways for Diagnosis and Treatment of the Atherosclerosis.

Atherosclerosis provokes a continuous worsening of affected vessels causing a blood flow diminution with several complications and with clinical manifestations that generally appear in advanced phases of the illness. Hence, the conventional therapies are not enough because the atherosclerotic injuries are often irrevocable. For this reason, emerges the necessity to implement smart ways of drug supply and develop new therapeutic targets that decrease the advance atherosclerotic lesion. It results due to particular interest to use new tools for prevention, diagnosis, and treatment of this cardiovascular disease, thus concentrating our attention to accomplish better management on the immune system. Finally, this mini-review highlights the most recent knowledge about nanotechnology as a robust, novel and promissory therapeutic option applied to atherosclerotic pathology, nevertheless, we also alert for possible issues associated with their use.

Asociación entre disglucemia y el consumo crónico de arsénico en aguas de zonas rurales de la provincia de San Juan / Association between dysglycemia and chronic consumption of arsenic in water from rural areas of the province of San Juan

La contaminación por arsénico (As) de las aguas subterráneas es un problema muy extendido; varias regiones presentan niveles importantes de consumo de agua contaminada, lo que determina en la población afectada signos de exposición aguda (toxicológica) y crónica. Con respecto a la exposición crónica, existen estudios previos que muestran como el consumo afecta adversamente la salud cardiometabólica. Estudios experimentales sugirieron que el As puede afectar la función de las células ß pancreáticas y la sensibilidad de la insulina mediante el mecanismo del estrés oxidativo; la captación y transporte de glucosa, la gluconeogénesis y la diferenciación de adipocitos; y a su vez, actuar como un disruptor endócrino afectando la función de los receptores hormonales e impactar sobre la diabetes a través de mecanismos epigenéticos. El objetivo de este estudio fue evaluar directamente el rol de la exposición a arsénico inorgánico en la homeostasis de la glucosa, cuya disfunción está ligada a la Diabetes. Concretamente se estudió la relación entre As urinario y disglicemia (a través de biomarcadores como la glucemia en ayunas y la hemoglobina glicosilada (HbA1C)) en personas de zonas rurales de los departamentos de Calingasta e Iglesia de la provincia de San Juan. Se encontró una gran diferencia en la prevalencia de disglicemias entre los pacientes que presentaron elevados niveles de As en orina (48,98%) y los controles no expuestos al consumo de agua con As (8,75 %)

Nanotecnología, un nuevo paradigma en el tratamiento de la aterosclerosis / Nanotechnology, a new paradigm in atherosclerosis treatment

La aterosclerosis, una conocida enfermedad arterial prevalente, ocasiona el deterioro progresivo de los vasos afectados provocando reducción del flujo sanguíneo con diversas complicaciones, y los síntomas suelen manifestarse en estadios avanzados de la enfermedad. En este sentido, las clásicas alternativas terapéuticas resultan insuficientes debido al carácter muchas veces irreversible del daño provocado. Por lo tanto, emerge la necesidad de implementar novedosas formas más eficaces para administrar fármacos y también el desarrollo de nuevas dianas terapéuticas que reduzcan la progresión de la lesión aterosclerótica. Además, resulta de especial interés la implementación de nuevas herramientas para la prevención, diagnóstico y tratamiento de esta patología cardiovascular, focalizando la atención en lograr un mejor control sobre el sistema inmunológico. En esta revisión se pone en relieve el conocimiento actual sobre la nanotecnología como una alternativa terapéutica potencial, moderna y prometedora, aplicada a la patología aterosclerótica, pero se advierte también sobre posibles complicaciones de su uso (AU)

Atherosclerosis, a known and prevalent disease, causes progressive deterioration of affected vessels, inducing a blood flow reduction with different complications, and its symptoms usually manifest in advanced stages of the disease. Therefore, the classic therapeutic alternatives are insufficient because the damages are many times irreversible. For this reason, there is a need to implement intelligent forms of drug administration and develop new therapeutic targets that reduce the progression of atherosclerotic lesion. The implementation of new tools for prevention, diagnosis and treatment of this cardiovascular disease is of special interest, focusing our attention on achieving a more effective control of the immune system. Finally, this review highlights the latest knowledge about nanotechnology as a powerful, modern, and promising therapeutic alternative applied to atherosclerotic disease, as well as warning of the potential complications with their use (AU)

Nanomedicine applied to cardiovascular diseases: latest developments.

Cardiovascular diseases are a major cause of disability and they are currently responsible for a significant number of deaths in a large percentage of the world population. A large number of therapeutic options have been developed for the management of cardiovascular diseases. However, they are insufficient to stop or significantly reduce the progression of these diseases, and may produce unpleasant side effects. In this situation, the need arises to continue exploring new technologies and strategies in order to overcome the disadvantages and limitations of conventional therapeutic options. Thus, treatment of cardiovascular diseases has become one of the major focuses of scientific and technological development in recent times. More specifically, there have been important advances in the area of nanotechnology and the controlled release of drugs, destined to circumvent many limitations of conventional therapies for the treatment of diseases such as hyperlipidemia, hypertension, myocardial infarction, stroke and thrombosis.

Nanotechnology, a new paradigm in atherosclerosis treatment. / Nanotecnología, un nuevo paradigma en el tratamiento de la aterosclerosis.

Atherosclerosis, a known and prevalent disease, causes progressive deterioration of affected vessels, inducing a blood flow reduction with different complications, and its symptoms usually manifest in advanced stages of the disease. Therefore, the classic therapeutic alternatives are insufficient because the damages are many times irreversible. For this reason, there is a need to implement intelligent forms of drug administration and develop new therapeutic targets that reduce the progression of atherosclerotic lesion. The implementation of new tools for prevention, diagnosis and treatment of this cardiovascular disease is of special interest, focusing our attention on achieving a more effective control of the immune system. Finally, this review highlights the latest knowledge about nanotechnology as a powerful, modern, and promising therapeutic alternative applied to atherosclerotic disease, as well as warning of the potential complications with their use.

Analysis of thiabendazole, 4-tert-octylphenol and chlorpyrifos in waste and sewage water by direct injection ­ micellar liquid chromatography.

A micellar liquid chromatographic method has been developed for the simultaneous quantification of the pesticides thiabendazole and chlorpyrifos, as well as an alkylphenol, which is included in pesticide formulations, i.e., 4-tert-octylphenol, in water. A sample was filtered and directly injected, avoiding large extraction steps using toxic solvents, thus expediting the experimental procedure. The contaminants were eluted without interferences in <17 min, using a mobile phase of 0.15 M sodium dodecyl sulfate ­ 6% 1-pentanol buffered at pH 3, running through a C18 column at 1 mL min(-1) under the isocratic mode. This optimal mobile phase was selected using a statistical approach, which considers the retention factor, efficiency and peak shape of the analytes measured in only a few mobile phases. The detection was carried out by measuring absorbance at 220 nm. The method was successfully validated in terms of specificity, calibration range (0.5-10 mg L(-1)), linearity (r(2) > 0.994), limit of detection and quantification (0.2-0.3; and 0.5-0.8 mg L(-1), respectively), intra- and interday accuracy (95.2-102.9%), precision (<8.3%), and ruggedness (<9.3%). The stability in storage conditions (at least 14 days) was studied. The method was safe, inexpensive, produced little pollutant and has a short analysis time, thus it is useful for the routine analysis of samples. Finally, the method was applied to analyse wastewater from the fruit-processing industry, wastewater treatment plants, and in sewage water belonging to the Castelló area (Spain). The results were similar to those obtained by an already reliable method.

Preparation and characterization of polymorphs of the glucocorticoid deflazacort.

The polymorphism of new and old active pharmaceutical ingredients (APIs) is of great importance due to performance, stability and processability aspects. The objective of this study was to investigate the polymorphism of deflazacort (DEF), a glucocorticoid discovered >40 years ago, since this phenomenon has not been previously investigated for this API. Using different methods for solid form screening, it was determined for the first time that DEF is able to exist as three forms: a crystalline (DEF-1); a hydrated X-ray amorphous (DEF-t-bw) and an anhydrous amorphous phase (DEF-g) obtained from manually grinding DEF-1. The in vitro and in vivo dissolution rates (DRs) of DEF-1 and DEF-t-bw, which were measured using the rotating disk method in water at 37 °C and the pellet implantation technique in rats, respectively, indicated that DEF-t-bw exhibited slightly faster in vitro and in vivo DRs than those of the crystalline form, but the values were not significantly different. In addition, it was determined that DEF-t-bw devitrifies to DEF-1 by the effect of pressure, humidity and heat. It was concluded that DEF is glucorticoid with low tendency to exhibit different crystalline forms and that DEF-t-bw has no advantages over DEF-1 in terms of solubility, DRs and solid-state stability.

Puntos de corte de 17-hidroxiprogesterona en la detección de Hiperplasia Suprarrenal Congénita / Cut offs levels of 17-hydroxyprogesterone in screening of Congenital Adrenal Hyperplasia / Pontos de corte da 17-hidroxiprogesterona na detecção de Hiperplasia Adrenal Congênita

El presente estudio investiga la utilidad de determinar puntos de corte ajustados según la edad gestacional y el peso al nacer de neonatos (2-100 días) en la cuantificación de 17-hidroxiprogesterona en muestras de sangre seca en papel de filtro. Se analizaron los resultados de 6.266 determinaciones realizadas en el marco del Programa Nacional de Fortalecimiento de la Detección Precoz de Enfermedades Congénitas. Los datos se dividieron en cuatro grupos; Grupo 1: recién nacido pretérmino con bajo peso; Grupo 2: recién nacido pretérmino con peso normal; Grupo 3: recién nacido a término con bajo peso y Grupo 4: recién nacido a término con peso normal. Se establecieron puntos de corte diferentes a partir del cálculo del percentilo 99 de la distribución de frecuencias. Basado en este análisis se realizó la comparación de la tasa de resultados falsos positivos que se obtuvieron según el punto de corte establecido por el fabricante y los obtenidos en el estudio. Los nuevos puntos de corte obtenidos fueron: 217,72 nmol/L, 102,14 nmol/L, 61,62 nmol/L y 82,38 nmol/L para los grupos 1, 2, 3 y 4 respectivamente. Se evidenció una tasa total de falsos positivos del 1% con los nuevos puntos de corte, significativamente menor a la tasa del 6,2% obtenida al utilizar el punto de corte del fabricante. Esto puso en evidencia que el uso de puntos de corte adecuadamente establecidos para la población en estudio reduce significativamente las complicaciones derivadas de las repeticiones de análisis y eventualmente la tasa de recitaciones, lo cual es una importante contribución a la Salud Pública.

The present work studies the usefulness of determining adjusted cut-offs for the quantification of 17-hydroxyprogesterone in dried blood samples on filter paper, taking into account the gestational age and weight of the neonates. The results of 6266 determinations made within the framework of the National Program of Strengthening Early Detection of Congenital Disease were analysed. Data were divided into groups, Group 1: early established from the calculation of the 99 percentiles of the frequency distribution. New cutoff points were: 217.72 nmol/L, 102.14 nmol/L, 61.62 nmol/L and 82.38 nmol/L for groups 1, 2, 3 and 4 respectively. It showed a total rate of 1% false positives with the new cut-off points, which was significantly lower than the rate of 6.2% obtained using the manufacturer's cutoff. This revealed that the use of properly established cut-offs for the study of population reduces significantly the complications derived fromn analysis repetitions and eventually the recitation rate, which is an important contribution to Public Health.

O presente estudo investiga a utilidade de determinar pontos de corte estabelecidos conforme a idade gestacional e o peso ao nascer de neonatos (2-100 dias) na quantificação da 17-hidroxiprogesterona em amostras de sangue seco em papel filtro. Foram analisados os resultados de 6.266 determinações feitas no âmbito do Programa Nacional de Fortalecimento da Detecção Precoce de Doenças Congênitas. Os dados foram divididos em quatro grupos; Grupo 1: recém-nascido pré-termo com baixo peso, Grupo 2: recém-nascido pré-termo com peso normal, Grupo 3: recém-nascido a termo com baixo peso e Grupo 4: recém-nascido a termo com peso normal e foram estabelecidos pontos de corte diferentes a partir do cálculo do percentil 99 da distribuição de frequências. Com base nesta análise foi realizada a comparação da taxa de resultados falsos positivos obtidos conforme o ponto de corte estabelecido pelo fabricante e os obtidos no estudo. Os novos pontos de corte obtidos foram: 217,72 nmol/L, 102,14 nmol/L, 61,62 nmol/L e 82,38 nmol/L para os grupos 1, 2, 3 e 4, respectivamente. Tornou-se evidente uma taxa total de 1% de falsos positivos, com os novos pontos de corte significativamente menor do que a taxa de 6,2% obtida utilizando o ponto de corte do fabricante. Isto revelou que o uso de pontos de corte de forma adequada estabelecidos para a população em estudo reduz significativamente as complicações decorrentes das repetições de análises e eventualmente a taxa de repetição de novos encontros, o que é uma importante contribuição para a saúde pública.

Puntos de corte de 17-hidroxiprogesterona en la detección de Hiperplasia Suprarrenal Congénita / Cut offs levels of 17-hydroxyprogesterone in screening of Congenital Adrenal Hyperplasia / Pontos de corte da 17-hidroxiprogesterona na detecþÒo de Hiperplasia Adrenal CongÛnita

El presente estudio investiga la utilidad de determinar puntos de corte ajustados según la edad gestacional y el peso al nacer de neonatos (2-100 días) en la cuantificación de 17-hidroxiprogesterona en muestras de sangre seca en papel de filtro. Se analizaron los resultados de 6.266 determinaciones realizadas en el marco del Programa Nacional de Fortalecimiento de la Detección Precoz de Enfermedades Congénitas. Los datos se dividieron en cuatro grupos; Grupo 1: recién nacido pretérmino con bajo peso; Grupo 2: recién nacido pretérmino con peso normal; Grupo 3: recién nacido a término con bajo peso y Grupo 4: recién nacido a término con peso normal. Se establecieron puntos de corte diferentes a partir del cálculo del percentilo 99 de la distribución de frecuencias. Basado en este análisis se realizó la comparación de la tasa de resultados falsos positivos que se obtuvieron según el punto de corte establecido por el fabricante y los obtenidos en el estudio. Los nuevos puntos de corte obtenidos fueron: 217,72 nmol/L, 102,14 nmol/L, 61,62 nmol/L y 82,38 nmol/L para los grupos 1, 2, 3 y 4 respectivamente. Se evidenció una tasa total de falsos positivos del 1% con los nuevos puntos de corte, significativamente menor a la tasa del 6,2% obtenida al utilizar el punto de corte del fabricante. Esto puso en evidencia que el uso de puntos de corte adecuadamente establecidos para la población en estudio reduce significativamente las complicaciones derivadas de las repeticiones de análisis y eventualmente la tasa de recitaciones, lo cual es una importante contribución a la Salud Pública.(AU)

The present work studies the usefulness of determining adjusted cut-offs for the quantification of 17-hydroxyprogesterone in dried blood samples on filter paper, taking into account the gestational age and weight of the neonates. The results of 6266 determinations made within the framework of the National Program of Strengthening Early Detection of Congenital Disease were analysed. Data were divided into groups, Group 1: early established from the calculation of the 99 percentiles of the frequency distribution. New cutoff points were: 217.72 nmol/L, 102.14 nmol/L, 61.62 nmol/L and 82.38 nmol/L for groups 1, 2, 3 and 4 respectively. It showed a total rate of 1% false positives with the new cut-off points, which was significantly lower than the rate of 6.2% obtained using the manufacturers cutoff. This revealed that the use of properly established cut-offs for the study of population reduces significantly the complications derived fromn analysis repetitions and eventually the recitation rate, which is an important contribution to Public Health.(AU)

O presente estudo investiga a utilidade de determinar pontos de corte estabelecidos conforme a idade gestacional e o peso ao nascer de neonatos (2-100 dias) na quantificaþÒo da 17-hidroxiprogesterona em amostras de sangue seco em papel filtro. Foram analisados os resultados de 6.266 determinaþ§es feitas no Ômbito do Programa Nacional de Fortalecimento da DetecþÒo Precoce de Doenþas CongÛnitas. Os dados foram divididos em quatro grupos; Grupo 1: recém-nascido pré-termo com baixo peso, Grupo 2: recém-nascido pré-termo com peso normal, Grupo 3: recém-nascido a termo com baixo peso e Grupo 4: recém-nascido a termo com peso normal e foram estabelecidos pontos de corte diferentes a partir do cálculo do percentil 99 da distribuiþÒo de frequÛncias. Com base nesta análise foi realizada a comparaþÒo da taxa de resultados falsos positivos obtidos conforme o ponto de corte estabelecido pelo fabricante e os obtidos no estudo. Os novos pontos de corte obtidos foram: 217,72 nmol/L, 102,14 nmol/L, 61,62 nmol/L e 82,38 nmol/L para os grupos 1, 2, 3 e 4, respectivamente. Tornou-se evidente uma taxa total de 1% de falsos positivos, com os novos pontos de corte significativamente menor do que a taxa de 6,2% obtida utilizando o ponto de corte do fabricante. Isto revelou que o uso de pontos de corte de forma adequada estabelecidos para a populaþÒo em estudo reduz significativamente as complicaþ§es decorrentes das repetiþ§es de análises e eventualmente a taxa de repetiþÒo de novos encontros, o que é uma importante contribuiþÒo para a saúde pública.(AU)