Rhabdomyosarcoma of the head and neck in pediatric patients: a systematic review.

BACKGROUND: Rhabdomyosarcoma (RMS) is a soft tissue malignant tumor of mesenchymal cell origin, which usually shows variable differentiation of muscle cells. It is the most common solid sarcoma in children. The most usual site of occurrence are the head and neck regions. RMS presents a variety of histologic features, and so differential diagnosis with other small round cell tumors is needed. Hence, it has been very useful to the field to undertake additional immunohistochemical studies to determine the diagnosis and, on occasions, to assign subtype tumors. MATERIAL AND METHODS: A systematic review of three databases (Medline, Biological Science Collection and Health & Medical Collection) was carried out with the purpose of analyzing rhabdomyosarcoma cases reported in the literature, specifically with localization in the head and neck regions in children. This strategy allowed us to identify the main anatomical site of appearance, the subtype of RMS, average age, histologic characteristics and immunohistochemistry markers used in a usual and any additional way. RESULTS: According to the selection criteria in this systematic review, twelve articles, and fourteen cases were identified that highlight that the histological diagnosis usually presents cellular heterogeneity. Therefore, immunohistochemistry is needed to confirm the diagnosis. CONCLUSIONS: Histologic characterization is not always sufficient for a conclusive diagnosis of RMS. Therefore, immunohistochemistry is helpful to determine the subtype and consequently, sometimes the behavior, treatment and prognosis. Additional markers may vary according to the institution and the need of particular cases.

Efficacy and Safety of Micropulse® Transscleral Cyclophotocoagulation in Glaucoma. / Eficacia y seguridad de la ciclofotocoagulación transescleral con micropulsos en el tratamiento del glaucoma.

OBJECTIVE: To report the results using Micropulse® transscleral cyclophotocoagulation (Iridex) in the treatment of glaucoma. METHODS: Retrospective study in adult patients with glaucoma with at least 6 months of follow-up, and only one session of Micropulse®. The same surgical technique was used in all cases. The only laser parameter that could vary was the total treatment duration (in seconds). The remaining parameters were fixed at 2 Watts of power and 0.5ms (31.3%) of active cycle. RESULTS: A total of 22 eyes of 17 patients with glaucoma of various types and stages were included (mainly congenital and pseudoexfoliation). The mean follow-up time was 7.9 months. The total treatment duration varied from 100 to 180seconds. Definition of success: 5mmHg

Enantiomeric fraction of styrene glycol as a biomarker of occupational risk exposure to styrene.

This work reports a new analytical approach for monitoring the enantiomeric ratios of styrene glycol (SG), encountered during the manufacture of plastics, by chiral liquid chromatography and the application as a biomarker for exposure to styrene. The isomers were separated using an AGP column running in the reverse phase and isocratic mode with a mobile phase consisting of 20 mM phosphate buffer saline (pH 4.15) and methanol at a flow rate of 0.8 mL/min. Photometric, polarimetric, and circular dichroism detectors were employed. The chromatographic enantioselective resolution (Rs) and selectivity index (α) values were determined to be 1.60 and 1.48 (by photometric detection), respectively. Calibration curves used for the quantification of the SG enantiomers were linear with a correlation coefficient >0.99; the detection limits were in the range of 0.03-0.16 µg, depending on the detector used. Recovery assays on synthetic samples (in triplicate) covering the full range of enantiomeric fractions (0.0-1.0) show accuracy values below 5% for the enantiomeric fraction (EF) in every case. An alternative method based on the measurement of anisotropy factors for the determination of EF, which is faster and does not require the separation of enantiomers, has also been developed. The enantiomeric excess of the toxicant biomarker styrene glycol has been determined. No previous direct enantioselective determination of styrene glycol was published.

Cáncer en pacientes jóvenes (Parte 2) Carcinomas de cavidad bucal en sujetos de bajo riesgo: presentación de 4 casos y revisión de la literatura / Oral cancers in low-risk subjects: presentation of 4 cases and literature review

El cáncer en cavidad bucal y de la región de cabeza y cuello se presenta con mayor frecuencia entre la quinta y sexta década de la vida generalmente atribuido al uso indiscriminado de substancias como el alcohol y el tabaco por un periodo de tiempo considerable. Sin embargo estudios recientes demuestran un incremento en la incidencia en pacientes jóvenes que nunca estuvieron expuestos a estos y a otros factores como riesgo ocupacional, predisposición genética, dieta. Se presenta 4 casos de carcinomas en cavidad bucal y revisión de la literatura.

Oral cavity cancer and head and neck region occurs most often between the fifth and sixth decade of life and is generally attributed to the indiscriminate use of substances such as alcohol and snuff for a period of time. However, recent studies show an increased incidence in younger patients who have never been exposed to these and other risk factors such as occupational factors, genetic predisposition, diet. Four cases of oral carcinoma are presented as well as a literature review.

Enantioseparation of the fungicide imazalil in orange juice by chiral HPLC. Study on degradation rates and extractive/enrichment techniques.

Imazalil ([1-(ß-allyloxy-2,4-dichlorophenethyl)imidazole]) is a systemic chiral fungicide used in postharvest protection of citruses against fungi development for during storage and transportation. The chemical structure of imazalil shows an asymmetric carbon in the C7 position. These enantiomers may have different toxicity. A method for both chiral enantiomers extraction and determination in orange juice is developed in order to provide their concentration and to study the degradation rates in orange juice. Spiked imazalil was extracted from orange juice by dispersive liquid-liquid micro extraction and solid phase extraction. Recovery assays of imazalil enantiomers from spiked orange juice samples showed that solid phase extraction is a better choice in order to obtain higher recovery values. Obtained chromatographic data show that within 24h the (-)-imazalil enantiomer decreases from 0.548 to 0.471 (expressed as enantiomer fraction).

Determination of enantiomeric excess by chiral liquid chromatography without enantiomerically pure starting standards.

A facile approach for the enantiomeric excess determination of enantiomeric mixtures without the necessity of pure enantiomer standards is presented. Promethazine and trimeprazine commercial nonracemic mixtures were used as cases study to probe the validity of the method. Chromatographic resolutions obtained with a chiral column AGP in reverse phase mode were 1.32-1.16 (promethazine) and 1.20-0.93 (trimeprazine) for the three detectors (circular dichroism, photometric and fluorimetric) in series. Results obtained showed that enantiomeric excess was 10.4, 8.71 and 8.58% for promethazine and 1.60, 1.23 and 1.80% for trimeprazine (medium values of 9.23 ± 1.01% and 1.54 ± 0.29%, respectively). Recovery assay over human serum samples, at three concentration levels, spiked with prometazine and submitted to solid-phase extraction, gave values of 99.09-93.48% [S-(-) enantiomer] and 98.51-91.89% [R-(+)-enantiomer]. Detection limits of promethazine enantiomers were between 0.02 µg (fluorimetric) and 1 µg (circular dichroism), and 0.02-1.1 µg for trimeprazine.

Enantiomeric resolution of bupivacaine by high-performance liquid chromatography and chiroptical detection.

This work reports a new analytical procedure for the separation and determination of the enantiomers of bupivacaine and the determination of the enantiomeric purity. The isomers were separated using a Chirex 3020 (250 mm x 4.6 mm) with a mobile phase of n-hexane:dichloroethane:ethanol (82:9:9, v/v/v) at a flow-rate of 1 ml min(-1) and UV, polarimetric and circular dichroism (CD) detection. Obtained retention times were 5.93 and 7.53 min (R and S) with a resolution of Rs=2.36. Precisions (RSD) were 1.83 and 2.02% (CD detection) and 3.07 and 1.26% (UV detection) for R- and S-enantiomers, respectively (at 10 microg level). Detection limits were 0.5 and 0.5 microg (R and S) with CD detection, and 0.9 and 0.3 microg with UV detection. Polarimetric detection was inadequate to perform a quantitative method at similar concentration ranges as UV and CD because of poor sensitivity. A procedure for determination of enantiomeric purity using a conventional chromatographic column (RP18, Luna) coupled to a CD detector and anisotropy factor (CD/UV) as analytical signal was also developed. Obtained results show that RSDs of 6.7-1.6% were obtained in the range of 0-100% enantiomeric purity.

Development and characterisation of an immunoaffinity chromatographic column for the on-line determination of the pesticide triclopyr.

An immunoaffinity column for the selective extraction and concentration of the herbicide triclopyr from water samples and quantification on line by HPLC has been developed. The immunoaffinity device was prepared by immobilising triclopyr antibodies to hydrazide derivatized azlactona beds. Efficient desorption of bound triclopyr was achieved with 70% ethanol/water solution. The column was evaluated regarding selectivity, recovery, capacity, saturation volume and reusability. Obtained results show that immunoaffinity chromatography (IAC) can be used for quantitative extraction, concentration and determination of triclopyr from water samples.

[Primary esophageal melanoma]. / Melanoma esofágico primario.

Primary malignant melanoma of the esophagus is an extremely rare non-epithelial neoplasm with a fatal prognosis. At present, approximately 184 cases have been published in the world literature. Of all published cases, 10 (5.4%) occurred in Spain. A 76 year-old man with malignant melanoma of the esophagus presented with dysphagia and weight loss, and treated by subtotal esophageal resection is reported. There was no history of previous cutaneous melanoma and ophthalmologic examination had been normal. At esophagoscopy a polypoid and pigmented mass (diameter 5 cm) almost completely occluding the lumen in the lower third of the esophagus was found. Multiple tumor biopsies were obtained. Histological diagnoses were made by examining endoscopic biopsy specimens and confirmed with resected specimens. The purpose of this communication is to present a case of primary esophageal malignant melanoma proved preoperatively by histological and immunohistochemical studies (positive reaction to the HMB-45 and S-100 antigen), followed by a review of the literature of these exceptional tumors.

Enzyme-linked immunosorbent assay by image analysis using a charge-coupled device array detector.

This paper describes a fluorescence enzyme-linked immunosorbent assay (ELISA) for the quantification of (+/-)-2-(2, 4-dichlorophen-oxy)propionic methyl ester (dichlorprop methyl ester). Antibodies for dichlorprop methyl ester were produced by immunizing rabbits with a conjugate of dichlorprop methyl ester with bovine serum albumin. Data acquisition on microtiter wells is performed by a spectrofluorometer through a fiber optic and by a charge-coupled device camera. A correlation was obtained between the image analysis data on ELISA and the data acquired by the spectrofluorometer. The results demonstrate that the fluorescence image analysis performed by the charge-coupled device detector is applicable to ELISA, and the analysis time, sensitivity, and precision of the ELISA procedure are compared to conventional fluorescence ELISA performed by the spectrofluorometer. The ELISA procedure was selective for structurally similar compounds or usually found in formulation pesticides. Concentrations for 50% displacement curves were dichlorprop, 83.59 microg/ml, and 2,4,5-T, 388.23 microg/ml; triclopyr, ioxynil, bentazone, and MCPA had no response.

Thermodynamic parameters for the molecular inclusion reaction of dulcin with beta-cyclodextrin. spectrofluorimetric determination of dulcin.

The inclusion of dulcin in alpha- and beta-cyclodextrin has been studied by fluorescence spectroscopy. To quantitatively describe complex formation between the beta-cyclodextrin and dulcin, an association constant of 290 M(-1) at 21 degrees was obtained. The thermodynamics associated with the complex formation between dulcin and beta-cyclodextrin in aqueous solution has been studied. The obtained value of DeltaG(0) = -13.7 kJ/mole at 21 degrees , together with DeltaH(0) = -33.6 +/- 2.3 kJ/mole and DeltaS(0) = -67.2 +/-8.3 Jmole(-1) K(-1) indicate that dulcin has a very marked tendency to associate with beta-cyclodextrin in water. The inclusion complex of dulcin in beta-cyclodextrin has been used to determine dulein in the range 0.13-5 mug/ml the method has been applied to determine dulcin in soft drinks.

Environmentally shifted fluorescence lifetimes for multicomponent phase-modulation fluorimetric analysis.

Several cyclodextrins, surfactants, and a series of three organic solvents-methanol, isoamylic alcohol, and hexanol-with different polarities and viscosities, were used to study the influence of the microenvironment on the fluorescent behavior of three diuretics-furosemide, triamterene, and piretanide. We concluded that on going from methanol to hexanol, the fluorescence lifetime of furosemide from 0.91 to 2.10 ns, that of triamterene from 4.54 to 4.44 ns, and that of piretanide from 5.24 to 10.37 ns. At 40 MHz, the phase shifts (excitation/emission) produced by furosemide, triamterene, and piretanide were 12.0, 29.6, and 30.2° in methanol and 27.8, 48.1, and 69.0° in hexanol. A three-factor, three-level factorial design allowed us to establish a calibration matrix of the three diuretics that covered the three ranges from 10 to 40, 1.5 to 6, and 0.1 to 0.4 µM for furosemide, piretanide, and triamterene, respectively. Data processing incorporated PLS adjustment values. The function was fitted to a phase-resolved fluorescence intensity at the three phase angles selected. Percentages recoveries were from 88 to 115%.

Determination of carbamate herbicide asulam in peaches following fluorescamine fluorigenic labelling.

Because of the primary aminic character of asulam, it is readily labelled with fluorescamine. A study of the variables affecting the derivatization reaction has been made. Two analytical approaches, that is, direct, synchronous spectrofluorimetry have been tested, and they both show good analytical performances. The linear dynamic range of the synchronous approach is 0.043-0.214 mug/ml and the relative standard deviation is 1.6%. The methods have been applied to the determination of asulam residues in peaches with recoveries of 85-106%.

Fluorimetric determination of indole derivatives by fluorophore generation in copper(II)-sulphuric acid solution.

A spectrofluorimetric procedure for the determination of indole-3-acetic acid, indole-3-propanoic acid and indole-3-butyric acid by derivatization with copper sulphate-sulphuric acid solution has been developed. The optimum reaction conditions, the effect of interferents and the advantages associated with the use of first- and second-derivative synchronous spectrofluorimetry have been studied. The detection limits are 3, 12 and 6 ng/ml for indole-3-acetic, indole-3-propanoic and indole-3-butyric acid, respectively.

Determination of carbaryl and its metabolite 1-naphthol in commercial formulations and biological fluids.

A simple and sensitive method for the determination of carbaryl in whole blood and commercial formulations, based on normal, and synchronous first- and second-derivative fluorescence spectra, is presented. Solvent effects on the spectral characteristics of carbaryl solutions and the influences of instrumental parameters are described in detail. Two methods have been developed, with neutral (for carbaryl) and basic (for 1-naphthol) media. Detection limits of 0.9 and 0.7 ng/ml were achieved for carbaryl and 1-naphthol, respectively, with the first-derivative approach.

Three-dimensional synchronous fluorescence spectrometry for the analysis of three-component alkaloid mixtures.

A study of a simple and sensitive method for the determination of berberine, luguine and sanguinarine in mixtures by normal and synchronous derivative spectrofluorimetry is described. The influence of solvents and other experimental variables is discussed. A three-dimensional plot of both emission-excitation and synchronous spectra obtained by a new software program provides additional information for optimizing instrumental parameters. Linear, normal and derivative calibration graphs are established in the ng/ml range. A statistical analysis of the results and their application to synthetic and natural samples is given.

A graphical derivative approach to the photometric determination of lutetium and praseodymium in mixtures.

The reaction of lanthanides with 1,4-dihydroxyanthraquinone has been examined and optimum conditions have been found for the separate spectrophotometric determination of Lu and Pr. A graphical method based on use of first and second derivative spectra has been developed for analysis of binary mixtures of the two, in concentration ratios from 1:5 to 5:1. Linear calibration curves were obtained between 1 and 10 mug/ml.