Lactobacillus plantarum IFPL935 impacts colonic metabolism in a simulator of the human gut microbiota during feeding with red wine polyphenols.

The colonic microbiota plays an important role in the bioavailibility of dietary polyphenols. This work has evaluated the impact on the gut microbiota of long-term feeding with both a red wine polyphenolic extract and the flavan-3-ol metabolizer strain Lactobacillus plantarum IFPL935. The study was conducted in the dynamic Simulator of the Human Intestinal Microbial Ecosystem (SHIME). The feeding of the gut microbiota model with red wine polyphenols caused an initial decrease in the counts of total bacteria in the ascending colon (AC), with Bacteroides, Clostridium coccoides/Eubacterium rectale and Bifidobacterium being the most affected bacterial groups. The bacterial counts recovered to initial numbers faster than the overall microbial fermentation and proteolysis, which seemed to be longer affected by polyphenols. Addition of L. plantarum IFPL935 helped to promptly recover total counts, Lactobacillus and Enterobacteriaceae and led to an increase in lactic acid formation in the AC vessel at the start of the polyphenol treatment as well as butyric acid in the transverse (TC) and descending (DC) vessels after 5 days. Moreover, L. plantarum IFPL935 favoured the conversion in the DC vessel of monomeric flavan-3-ols and their intermediate metabolites into phenylpropionic acids and in particular 3-(3'-hydroxyphenyl)propionic acid. The results open the possibilities of using L. plantarum IFPL935 as a food ingredient for helping individuals showing a low polyphenol-fermenting metabotype to increase their colonic microbial capacities of metabolizing dietary polyphenols.

A simple HPLC-ESI-MS method for the direct determination of ten pteridinic biomarkers in human urine.

Pteridines are important biomarkers metabolites related to several biochemical pathways such as activation of the cell-mediated immune system, biosynthesis of neurotransmitters, etc. The level of pteridinic compounds in urine is considered as an important clinic criterion. In this work, a new liquid chromatography-mass spectrometry (LC-MS) method is proposed to determine several pteridinic biomarkers in urine samples using 6-methylpterin as internal standard (I.S.). Matrix effect was evaluated and several dilutions of urine were tested in order to study the evolution of signal suppression. Sample preparation was limited to 10-fold dilution of the filtered urine followed by injection onto a reversed-phase column. The signal was recorded in selected ion monitoring mode. The lowest limit of detection was found for pterin (values ranged from 1.70 to 3.88 ng mL(-1)) whereas the highest limit was for xanthopterin (values ranged from 10.5 to 49.9 ng mL(-1)) for healthy volunteers between 17 and 51 years old.

Comparison of the predictive ability of several second-order multivariate methods in the simultaneous determination of two therapeutic drugs in human urine.

The aim of this paper is to study the applicability of second-order multivariate methods in the simultaneous determination of two therapeutic drugs in human urine samples. The studied drugs, irinotecan and thalidomide, are used in the treatment of malignant tumours. Irinotecan (CPT-11) is used to treat colon cancer; recent studies have shown the benefits of using thalidomide in combination with CPT-11 in the treatment of this disease. CPT-11 is highly fluorescent, but the native fluorescence of thalidomide is very weak. The second-order methods assayed were parallel factor analysis (PARAFAC), unfolded partial least-squares (U-PLS) and multidimensional partial least-squares (N-PLS), both combined with the residual bilinearization procedure (RBL). The excitation-emission matrices (EEMs) of the samples were recorded as analytical signal. The accuracy and precision of the algorithms were evaluated through the root mean square error of prediction (RMSEP) and the elliptical joint confidence region test (EJCR), obtaining better results with PARAFAC, which was successfully applied to the determination of thalidomide and CPT-11 in human urine samples, after a previous liquid-liquid extraction with chloroform.

On line photochemically induced excitation-emission-kinetic four-way data: analytical application for the determination of folic acid and its two main metabolites in serum by U-PLS and N-PLS/residual trilinearization (RTL) calibration.

The determination of folic acid and its two main serum metabolites, 5-methyltetrahydrofolic acid and tetrahydrofolic acid, has been accomplished using four-way data modelled by the third-order multivariate calibration methods unfolded and N-dimensional partial least-squares (U-PLS and N-PLS), in combination with the separate procedure known as residual trilinearization (RTL). The four-way data were acquired by following the photochemical reaction of these compounds by on line irradiation with a UV lamp. The excitation-emission matrices (EEMs) were recorded as a function of the irradiation time, using a fast scanning spectrofluorimeter. The method achieves selectivity from the different rates at which the corresponding photoproducts of the folic acid derivatives are formed and degraded. Several N-dimensional chemometric algorithms were used and the method was applied to the determination of these compounds in serum samples. The best algorithms to perform the multivariate calibration were U-PLS and N-PLS in combination with the separate residual trilinearization procedure, achieving the second-order advantage. The approach allows minimizing or eliminating traditionally time-consuming sample pre-treatments and can facilitate quantifying an analyte in its native environment.

Photoinduced fluorimetric determination of folic acid and 5-methyltetrahydrofolic acid in serum using the kinetic evolution of the emission spectra accomplished with multivariate second-order calibration methods.

Second-order multivariate calibration methods in combination with a continuous flow system, which allows for the continuous on-line irradiation of the analytes, have been employed for the determination of folic acid and its main metabolite 5-methyltetrahydrofolic acid in serum samples. An experimental central composite design, together with response surface methodology, has been used to find the optimum instrumental variables to perform the photochemical reaction. The time evolution of the emission spectra of the generated photoproducts, in the range 330-540 nm, after irradiation at 275 nm for 20 min, provided the three-way data set employed. On the basis of the differences on the kinetic rates of the photoreaction of both analytes, direct determination of the compounds in human plasma has been accomplished. The second-order methods assayed were parallel factor analysis (PARAFAC), self-weighted alternating trilinear decomposition (SWATLD), and unfolded partial least-squares (U-PLS), multidimensional partial least-squares (N-PLS), and bilinear least-squares (BLLS), all three in combination with the residual bilinearization procedure (RBL).

Resolution of ofloxacin-ciprofloxacin and ofloxacin-norfloxacin binary mixtures by flow-injection chemiluminescence in combination with partial least squares multivariate calibration.

A flow-injection chemiluminescence (CL) method is described for the determination of ciprofloxacin (CIP), norfloxacin (NOR) and ofloxacin (OFL), commonly used antibiotics of the fluoroquinolones family. The method is based on the CL reaction of the fluoroquinolones with tris(2,2'-bipyridyl) ruthenium(II) and Ce (IV), in sulfuric acid medium. The maximum CL emission, given at 0.45 min for CIP, at 0.35 min for NOR and at 0.04 min for OFL, respectively, were measured, allowing the simple application of the proposed method to the routine analysis of the antibiotics. The methods were applied to the determination of CIP, NOR and OFL, in several pharmaceutical preparations, with very satisfactory results, and validated by a previously reported HPLC method. The time-resolved equipment allowed the measurement of the kinetic evolution of the chemiluminescence signals. In base to the differences in the kinetic behaviour of ofloxacin with respect to ciprofloxacin and norfloxacin, binary mixtures of the drugs were resolved by using the time-resolved chemiluminescence signals, in combination with first-order partial least-squares (PLS) multivariate calibration.

Evaluation of unfolded-partial least-squares coupled to residual trilinearization for four-way calibration of folic acid and methotrexate in human serum samples.

The combination of unfolded-partial least-squares (U-PLS) with a recently proposed separate procedure, known as residual trilinearization (RTL), has been successfully employed for four-way data calibration. The chemometric method employs the evolution of excitation-emission matrices (EEMs) with time, for the resolution of folic acid-methotrexate mixtures, in human serum samples. The fluorogenic products monitored correspond to the oxidation of the studied analytes with potassium permanganate, in slightly acidic medium. The reaction is developed in 7min and followed using a fast-scanning spectrofluorimeter, capable of recording each complete EEM in 12s. This allows the acquisition of 10 successive EEMs, at different reaction times, during the development of the oxidation reaction, given rise to the four-way data set employed. The procedure, which had been previously reported for urine determination, is extended to serum analysis in this work. The combination of U-PLS/RTL is providing enhanced predictive results in comparison with standard methods as PARAFAC and N-PLS, in the presence of human serum, where significant unexpected components and or inner filter effects may occur.

Four-way calibration applied to the simultaneous determination of folic acid and methotrexate in urine samples.

First-, second- and third-order calibration methods were investigated for the simultaneous determination of folic acid and methotrexate. The interest in the determination of these compounds is related to the fact that methotrexate inhibits the body's absorption of folic acid and prolonged treatment with methotrexate may lead to folic acid deficiency, and to the use of folic acid to cope with toxic side effects of methotrexate. Both analytes were converted into highly fluorescent compounds by oxidation with potassium permanganate, and the kinetics of the reaction was continuously monitored by recording the kinetics curves of fluorescence emission, the evolution with time of the emission spectra and the excitation-emission matrices (EEMs) of the samples at different reaction times. Direct determination of mixtures of both drugs in urine was accomplished on the basis of the evolution of the kinetics of EEMs by fluorescence measurements and four-way parallel-factor analysis (PARAFAC) or multiway partial least squares (N-PLS) chemometric calibration. The core consistency diagnostic (CORCONDIA) was employed to determine the correct number of factors in PARAFAC and the procedure converged to a choice of three factors, attributed to folic acid, methotrexate and to the sum of fluorescent species present in the urine.

Stopped-flow and kinetic-fluorimetric determination of quinalphos in water samples.

The hydrolysis of the pesticide quinalphos in basic medium was kinetically followed and the measurement of the reaction rates allowed us to develop two kinetic-fluorimetric methods. In one of them the mixing of the reagents was directly performed in the measurement cell and, in the another one, the stopped-flow mixing technique was used. The reaction was completed in 100 s after the reactants were mixed and it allowed the simple application of the proposed methods to routine analyses of the pesticide. The sensitivity of the methods was very high, being the detection limits 50 and 140 ng mL(-1) for the manual procedure and the stopped-flow mixing technique, respectively. Both methods were compared using regression with uncertainties in both axes. The effect of the presence of several pesticides in the determination was tested. A solid-phase extraction process was also developed for the application of the methods to diverse waters samples. The proposed kinetic-fluorimetric methods were applied to the determination of quinalphos in drinking water, well water and river water, with very satisfactory results.

[Recurrent ingestion of foreign bodies. Unusual presentation of Munchausen by Proxy syndrome]. / Ingestión reiterada de cuerpos extraños. Forma inusual de presentación del síndrome de Munchausen por poderes.

A case with unusual presentation of Munchausen syndrome by proxy is reported. It was shown through reiterated ingestion of foreign bodies (two earrings, probably a button but not confirmed, a 5 cm. screw and two sewing needles) perpetrated by a 22-year-old mother with a psychiatric record of behavior disorders and family dysfunctions on a 10-month-old infant with a history of prematurity, repeated visits to emergency rooms, and nonjustified multiple hospital admissions. The difficulties in the diagnosis and the need for an early detection are brought up, making considerations in regard to indicators, diagnostic criteria, and management procedure.

[Children at risk. Our experience]. / Niños de riesgo. Nuestra experiencia.

Seventy children in a situation of risk, evaluated and treated in the Social Work Unit of the Children's Hospital "Virgen del Rocío" over a period of 22 months, were analyzed. Of these children, 89% corresponded to low-middle, low or very low social classes. The most common problems included those of the family (77.1%) with history of maltreatment and unwanted pregnancies being the most prevalent problems. In second place was the personal pathology of the parents (74.2%), with mental disorders and alcoholism being the main causes, followed by drug addiction and delinquency. Social factors (57.1%), which included predominantly unemployment and illiteracy, were the next most common finding. The final factor was the personal pathology of the child (10%). The consequences of the risk situation are described, emphasizing the psychic and treatment carried out. Final comments are made underlining the importance of awareness and professional training, multiprofessional teams, means of detecting and intervention into the problems, manpower and material as well as how to carry out studies in this area.