The present paper deals with the enantiomeric separation of nuarimol enantiomers by affinity EKC‐partial filling technique using HSA as chiral selector. Firstly, a study of nuarimol interactions with ...HSA by CE‐frontal analysis was performed. The binding parameters obtained for the first site of interaction were n1 = 0.84; K1 = 9.7 ± 0.3×103 M–1 and the protein binding percentage of nuarimol at physiological concentration of HSA was 75.2 ± 0.2%. Due to the moderate affinity of nuarimol towards HSA the possibility of using this protein as chiral selector for the separation of nuarimol using the partial filling technique was evaluated. A multivariate optimization approach of the most critical experimental variables in enantioresolution, running pH, HSA concentration and plug length was carried out. Separation of nuarimol enantiomers was obtained under the following selected conditions: electrophoretic buffer composed of 50 mM Tris at pH 7.3; 160 μM HSA solution applied at 50 mbar for 156 s as chiral selector; nuarimol solutions in the range of 2–8×10–4 M injected hydrodynamically at 30 mbar for 2 s and the electrophoretic runs performed at 30°C applying 15 kV voltage. Resolution, accuracy, reproducibility speed and cost of the proposed method make it suitable for quality control of the enantiomeric composition of nuarimol in formulations and for further toxicological studies. The results showed a different affinity between nuarimol enantiomers towards HSA.
The microalgae genus
Scenedesmus is commonly found in freshwater bodies, wastewater facilities and water polluted with heavy metals. Phenotypic plasticity in
Scenedesmus has been documented in ...response to a wide variety of conditions; however, heavy metals have not been comprehensively documented as phenotypic plasticity inducers. In this study, we report the phenotypic plasticity of
Scenedesmus incrassatulus (a non-spiny, four-cell coenobium forming species) in response to EC
50 value of copper, cadmium and hexavalent chromium.
S. incrassatulus was grown in batch cultures in the presence of each metal. Chlorophyll-
a content, cell size, parameters derived from the schematic energy-flux model for photosystem II, and morphotype expressions were recorded. Divalent cation metals induced unicellular forms, and hexavalent chromium produced out-of-shape coenobia corresponding to various stages of autospore formation. The changes induced by divalent metals were interpreted as phenotypic plasticity, because they were always associated to population doublings and were reversible when toxicant pressure was removed (only for Cu). Copper was the best inductor of unicellular forms and also affected significantly all the photosynthetic parameters measured. The developed morphotypes could confer ecological advantages to
S. incrassatulus in metal stressed environments.
Nowadays, there is a special interest within the pharmaceutical laboratories to develop single enantiomer formulations and consequently a need for analytical methods to determine the enantiomeric ...purity of drugs. The present paper deals with the enantiomeric separation of promethazine and trimeprazine enantiomers by affinity electrokinetic chromatography (AEKC)-partial filling technique using human serum albumin (HSA) as chiral selector. A multivariate optimization of the most critical experimental variables in enantioresolution, running pH, HSA concentration and plug length, is carried out to obtain enantioresolution of promethazine and trimeprazine. The estimated maximum and optimum resolution of trimeprazine and prometazine enantiomers (Rs=1.74 and 2.01, respectively) corresponded to the following experimental conditions: pH 7.5; HSA 170 microM and plug length 190 s and pH 7.6; HSA 170 microM and plug length 170 s, for trimeprazine and prometazine, respectively. The developed methodologies were applied for the enantiomeric quality control of promethazine and trimeprazine enantiomers in commercially available pharmaceutical formulations. Resolution, accuracy, reproducibility, cost and sample throughput of the proposed methodologies make it suitable for quality control of the enantiomeric composition of promethazine and trimeprazine in pharmaceutical preparations.
From July 2003 through October 2004, 42 patients became infected by strains of Leuconostoc mesenteroides subsp. mesenteroides (genotype 1) in different departments of Juan Canalejo Hospital in ...northwest Spain. During 2006, 6 inpatients, also in different departments of the hospital, became infected (genotypes 2-4). Parenteral nutrition was the likely source.
Método: Investigación descriptiva transversal, correlacional, realizada en 2015-2016 en La Libertad (Perú) con 1110 adultos mayores de 60 años y más, ambos sexos, aptos o no física y mentalmente, ...quienes cumplieron los criterios de inclusión y aceptaron voluntariamente participar en el estudio. Se midieron las variables cognición con el Minimental State Examination (MMSE) de Folstein y cols, la capacidad funcional con el indice de Katz para actividades básicas de la vida diaria (ABVD) y la escala de Lawton y Brody para las actividades instrumentales de la vida diaria (AIVD). Recolectada la información, se hizo un análisis bivariado para determinar la relación entre las variables utilizando la prueba chi cuadrado. Palabras clave: adulto mayor, función cognitiva, capacidad funcional, actividades de la vida diaria.
In the last years, capillary electrophoresis (CE) has gained considerable interest in pharmaceutical laboratories for controlling the chiral purity of drugs. This paper describes a simple and fast ...method for resolution of propranolol enantiomers by affinity capillary electrophoresis (ACE) using human serum albumin (HSA) as chiral selector. The effect of several experimental variables such as HSA concentration, temperature, chiral selector plug length and addition of organic modifiers, on the separation is evaluated. Complete enantioresolution of
R- and
S-propranolol was achieved in less than 5
min when the capillary was completely filled with 100
μM HSA solution and the electrophoresis was carried out with 67
mM phosphate buffer (pH 7.4) at 20
kV and 35
°C. Peaks were assigned to each propranolol enantiomer according to their relative affinities to HSA. The proposed method was applied to the analysis of pharmaceutical preparations containing propranolol. Resolution, accuracy, reproducibility, cost and sample throughput of the proposed method make it suitable for quality control of the enantiomeric composition of propranolol in pharmaceuticals.
Chromatographic evaluation of the toxicity in fish of pesticides Bermúdez-Saldaña, José María; Escuder-Gilabert, Laura; Medina-Hernández, María José ...
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences,
01/2005, Letnik:
814, Številka:
1
Journal Article
Recenzirano
Ecotoxicity assessment is essential before placing new chemical substances on the market. An investigation of the use of the chromatographic retention (log
k) in biopartitioning micellar ...chromatography (BMC) as an in vitro approach to evaluate the toxicity in fish of pesticides (acute toxicity levels as pLC
50) is proposed. A heterogeneous data set of 85 pesticides from six chemical families with available experimental fish toxicity data (ECOTOX database from U.S. Environmental Protection Agency (EPA)) was used. For pesticides exhibiting non-polar narcosis mechanism in fish (non-specific toxicity), more reliable models and precise pLC
50 estimations are obtained from log
k (quantitative retention–activity relationships, QRAR) than from log
P (quantitative structure-activity relationships, QSAR) or ECOSAR (ECOSAR program from U.S. EPA).
In the field of the quantitative structure–retention and retention–activity relationships (QRAR and QSRR) is crucial to obtain consistent retention factors (
k). For this purpose, two unbiased ...approaches to estimate
k are used: (i) the IUPAC approach (based on the extra-column time correction) and (ii) the ‘2-references’ approach (based on the
k estimation respect to two prefixed reference
k values). Three reference chemicals were selected attending to their retention time, chemical stability and non-ionic character. Consistent retention factor values for these references were estimated for C
18 chromatographic columns and Brij35 solutions as mobile phases after statistical analysis. The comparison between the
k values estimated for a set of 65 test chemicals using the IUPAC and the ‘2-references’ approach shows that the last one gives consistent long-term values useful for QRAR and QSRR modelling purposes.
(1) Background: We examine trends (2001–2015) in the use of non-invasive ventilation (NIV) and invasive mechanical ventilation (IMV) among patients hospitalized for acute exacerbation of chronic ...obstructive pulmonary disease (AE-COPD). (2) Methods: Observational retrospective epidemiological study, using the Spanish National Hospital Discharge Database. (3) Results: We included 1,431,935 hospitalizations (aged ≥40 years) with an AE-COPD. NIV use increased significantly, from 1.82% in 2001–2003 to 8.52% in 2013–2015, while IMV utilization decreased significantly, from 1.39% in 2001–2003 to 0.67% in 2013–2015. The use of NIV + invasive mechanical ventilation (IMV) rose significantly over time (from 0.17% to 0.42%). Despite the worsening of clinical profile of patients, length of stay decreased significantly over time in all types of ventilation. Patients who received only IMV had the highest in-hospital mortality (IHM) (32.63%). IHM decreased significantly in patients with NIV + IMV, but it remained stable in those receiving isolated NIV and isolated IMV. Factors associated with use of any type of ventilatory support included female sex, lower age, and higher comorbidity. (4) Conclusions: We found an increase in NIV use and a decline in IMV utilization to treat AE-COPD among hospitalized patients. The IHM decreased significantly over time in patients who received NIV + IMV, but it remained stable in patients who received NIV or IMV in isolation.
INTRODUCTION AND OBJECTIVES: An epidemiological study of descriptive and analytical cases was developed. The aim was to evaluate sports injuries occurring during the practice of recreational sport in ...the geographical area of all regions of Spain. METHODS: Trauma medical centers and physiotherapy clinics were selected. Surveys were passed through interviewers in a total of 1616 subjects who had suffered an injury in the last 12 months while practicing sport as a leisure activity. The information collection was performed using a digital database hosted on a web server connected to a digital survey through which the subjects' responses were recorded. RESULTS: The sports where most injuries occurred was football (27.6% of all accidents), followed by running (8.6%), futsal (7.9%) and basketball (7.7 %). Attending the underlying determinant factors of injury, some relation between them were found, which may lead us to better know the injuries causation. CONCLUSIONS: The results show a general description of the influence that sports injuries and their consequences mean in Spanish society. More comparative studies of cases of injured and uninjured athletes in amateur sport would be advisable to establish preventive campaigns.
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