Evaluation of different factors influencing objective measurement of skin color by colorimetry.

BACKGROUND: Objective determination of skin color has become an essential requirement in managing pigmentary disorders including vitiligo. The readings of available devices can be influenced by factors such as surrounding temperature, vasodilation/constriction, and skin surface properties. Our aim was to investigate the influence of hair color and length, skin stretching, incomplete contact of the device with the skin, and the pressure with which the device is applied to the test area on skin color determination. MATERIALS AND METHODS: Dermacatch® was used to determine the influence of hair color and length in 30 vitiligo patients, and of wrinkles, incomplete contact of the device with the skin and pressure of the device on the test area in 30 healthy volunteers on melanin and erythema indices measured by the device. RESULTS: Melanin index was significantly higher in lesions with black hair compared to lesions with white hair (P < 0.001) and the MI significantly decreased when the black hair was shaved (P < 0.001) and when the skin over the test area was stretched (P < 0.001). Incomplete contact of the device with the test area led to significantly higher MI (P < 0.001) and lower EI (P < 0.001). Meanwhile, high pressure induced by the device on the test area led to significantly lower MI (P < 0.001) and significantly higher EI (P < 0.001). CONCLUSIONS: Factors influencing the readings of devices used for objective determination of skin color have to be taken consideration to ensure accuracy of the measurements done.

Perspective: The first ten years of broadband chirped pulse Fourier transform microwave spectroscopy.

Since its invention in 2006, the broadband chirped pulse Fourier transform spectrometer has transformed the field of microwave spectroscopy. The technique enables the collection of a ≥10 GHz bandwidth spectrum in a single shot of the spectrometer, which allows broadband, high-resolution microwave spectra to be acquired several orders of magnitude faster than what was previously possible. We discuss the advantages and challenges associated with the technique and look back on the first ten years of chirped pulse Fourier transform spectroscopy. In addition to enabling faster-than-ever structure determination of increasingly complex species, the technique has given rise to an assortment of entirely new classes of experiments, ranging from chiral sensing by three-wave mixing to microwave detection of multichannel reaction kinetics. However, this is only the beginning. Future generations of microwave experiments will make increasingly creative use of frequency-agile pulse sequences for the coherent manipulation and interrogation of molecular dynamics.

Spectral Analysis of Dynamic PET Studies: A Review of 20 Years of Method Developments and Applications.

In Positron Emission Tomography (PET), spectral analysis (SA) allows the quantification of dynamic data by relating the radioactivity measured by the scanner in time to the underlying physiological processes of the system under investigation. Among the different approaches for the quantification of PET data, SA is based on the linear solution of the Laplace transform inversion whereas the measured arterial and tissue time-activity curves of a radiotracer are used to calculate the input response function of the tissue. In the recent years SA has been used with a large number of PET tracers in brain and nonbrain applications, demonstrating that it is a very flexible and robust method for PET data analysis. Differently from the most common PET quantification approaches that adopt standard nonlinear estimation of compartmental models or some linear simplifications, SA can be applied without defining any specific model configuration and has demonstrated very good sensitivity to the underlying kinetics. This characteristic makes it useful as an investigative tool especially for the analysis of novel PET tracers. The purpose of this work is to offer an overview of SA, to discuss advantages and limitations of the methodology, and to inform about its applications in the PET field.

Propuesta de un procedimiento de validación de un método para la determinación de cinc sérico: cumplimiento de los requisitos de la ISO 17025 / Validation of an in-house method for the determination of zinc in serum: Meeting the requirements of ISO 17025

Objetivo. Elaborar un esquema de validación de una técnica analítica siguiendo los requisitos de la ISO 17025. Material y métodos. Teniendo en cuenta la ISO 17025, los parámetros verificados fueron: selectividad, modelo de calibración y linealidad, precisión, exactitud, incertidumbre de medida e interferencias analíticas. Resultados. El procedimiento desarrollado fue aplicado satisfactoriamente para cuantificar cinc en suero por espectrofotometría de absorción atómica. Conclusión. Finalmente, se ha demostrado que nuestro método cumple con los requisitos exigidos de selectividad, linealidad, exactitud y precisión, haciéndolo adecuado para el fin requerido (AU)

Objective. The aim of this report is to propose a scheme for validation of an analytical technique according to ISO 17025. Material and methods. According to ISO 17025, the fundamental parameters tested were: selectivity, calibration model, precision, accuracy, uncertainty of measurement, and analytical interference. Results. A protocol has been developed that has been applied successfully to quantify zinc in serum by atomic absorption spectrometry. Conclusion. It is demonstrated that our method is selective, linear, accurate, and precise, making it suitable for use in routine diagnostics (AU)

Evaluación de las mediciones de hemoglobina no invasiva con el dispositivo Masimo Rainbow Radical-7 ® en un paciente portador de oxigenación extracorpórea de membrana / Evaluation of non-invasive hemoglobin measurements using the Masimo Rainbow Radical-7 ® device in a patient with extracorporeal membrane oxygenation

Los dispositivos de asistencia circulatoria tipo oxigenación extracorpórea de membrana están indicados en casos de shock cardiogénico refractario al tratamiento convencional óptimo. La hemorragia es una grave complicación de dichos sistemas debido fundamentalmente a los trastornos de la coagulación provocados por la administración continua de heparina y a la disfunción plaquetaria. Los controles seriados de la coagulación y de la hemoglobina (Hb) son imprescindibles. Las mediciones de Hb se pueden realizar a través de gasometrías repetidas y más recientemente con un nuevo sensor espectrofotométrico, dispositivo Masimo Rainbow Radical-7®, que nos ofrece valores de Hb de forma continua y no invasiva. Presentamos el caso de un paciente sometido a cirugía cardíaca que requirió oxigenación extracorpórea de membrana por shock cardiogénico grave en el postoperatorio inmediato. Comparamos la correlación y el grado de concordancia respecto a los niveles de Hb cuantificados por 2 sistemas existentes en la práctica clínica. Nuestros resultados indican que el monitor espectrofotométrico Masimo® mostró valores de Hb equiparables estadísticamente, en correlación (r = 0,85; p < 0,01) y concordancia, a los obtenidos por gasometrías seriadas con el Analizador ABL800 FLEX® (longitud de onda). Ante estos resultados consideramos el dispositivo evaluado como una alternativa válida para el seguimiento continuo de la Hb y el control de la hemorragia en este tipo de pacientes (AU)

Circulatory assist devices such as extracorporeal membrane oxygenation are indicated in cases of cardiogenic shock refractory to optimal conventional treatment. Bleeding is a serious complication of such systems, mainly due to coagulation disorders caused by continuous administration of heparin, as well as platelet dysfunction. Serial coagulation and hemoglobin (Hb) measurements are essential. Hb measurements can be performed through repeated arterial blood gasometry, and more recently with a new spectrophotometric sensor, Masimo Rainbow Radical-7® device, which gives Hb values continuously and non-invasively. We report a case of a patient undergoing cardiac surgery who required extracorporeal membrane oxygenation for severe cardiogenic shock immediately after surgery. We compare the correlation and the level of agreement with Hb levels measured by 2 existing systems in clinical practice. Our results indicate that the Masimo® spectrophotometric monitor showed statistically comparable Hb values, in the correlation (r = .85; P < .01) and in agreement with those obtained by serial blood gas analyzer, ABL800 FLEX® (wavelength). In view of these results we consider the Masimo® device as a valid alternative for the continuous follow-up of the Hb and control of bleeding in these patients (AU)

Review on recent applications of the liquid waveguide capillary cell in flow based analysis techniques to enhance the sensitivity of spectroscopic detection methods.

Incorporation of long path length liquid waveguide capillary cell (LWCC or LCW) into spectrometric detection systems can increase the sensitivity of these by orders of magnitude (up to 500 times), and consequently can reduce the detection limits. The combination of the long path length spectrophotometry with flow methodologies can provide analytical solutions for various challenges in the field of environmental, biochemical and food chemistry. In this present work, the analytical applications of the long capillary cells are summarised and critically discussed. A historical overview of the cell development is given; applications in different areas are presented and grouped by analyte type. Major improvements achieved based on the use of the LWCC in the analytical characteristics (like sensitivity and detection limit) are emphasised while some of the limitations are also discussed.

Asociación de la deficiencia de cinc con factores inmunológicos y clínicos / Association between zinc deficiency and immunological and clinical factors

INTRODUCCIÓN: El cinc es un elemento imprescindible para el buen funcionamiento del organismo en todas las etapas de la vida, tanto para la síntesis celular, la reparación de tejidos y el desarrollo cerebral como para el crecimiento. Es cofactor de numerosas enzimas (lactato deshidrogenasa, fosfatasa alcalina, anhidrasa carbónica, carboxipeptidasa, SOD, etc.), siendo muy importante para el funcionamiento de la próstata, desarrollo de los órganos de reproducción, para buen funcionamientode la retina, y está involucrado en la regeneración de rodopsina. El sistema inmune requiere de Zn y es necesario para el mantenimiento de la integridad estructural del ADN y la síntesis de ácidos nucleicos y proteínas. OBJETIVO: El objetivo es estudiar el estado nutricional del cinc en una población sana y establecer la relación con otros factores como ejercicio físico, consumo de alcohol, y otros parámetros bioquímicos como GOT, FA, CPK, ASLO Inmunoglobulina G, Inmunoglobulina A, Alfa 1 anti tripsina, LDH, factor reumatoide. METODOLOGÍA: El estudio se realizó en un colectivo de personas de 21 a 59 años, 56 hombres y 61mujeres. Los criterios de inclusión se basaron en la aceptación de los sujetos a participar en el estudio y en que dichos sujetos no presentaran ningún tipo de patología que pudiera afectar su situación nutricional. El Zn se analizó mediante Espectrofotometría de Absorción Atómica (AAS) en muestras de eritrocitos y plasma mineralizadas por vía húmeda. Se aplicó un cuestionario de frecuencia de consumo, y mediante programa informático Nutriber® (Mataix, y Garcia Diz, 2006) se obtuvo el % RDA. Se contó con la aceptación del Comité ético y el consentimiento informado. Los parámetros clínicos analizados se determinaron en un equipo autoanalizador Hitachi mediante método colorimétrico(AU)

RESULTADOS: La recomendación de ingesta de Zn en la población adulta es de 7 a 15 mg/d. Nuestros resultados muestran una ingesta de Zn por debajo de los 2/3 de las RDA en un 56% de los individuos estudiados. En plasma, aparece deficiencia de Zn en el 17%, y en eritrocitos en un 35%. Se encontró una correlación significativa positiva entre los niveles de Zn y el consumo de alcohol, los niveles de GOT, FA, CPK, ASLO, IgG, IgA y α-1-Antitripsina, y negativa con la intensidad de ejercicio, LDH y factor reumatoide CONCLUSIÓN: según los resultados obtenidos, se hace necesario controlar tanto la ingesta como los niveles plasmáticos y eritrocitarios de Zn para que la población no sufra carencias en este mineral que derivan en el desarrollo de numerosas enfermedades, tal y como se demuestra con las asociaciones encontradas con los parámetros clínicos inmunológicos y enzimáticos que afectan a la integridad celular(AU)

INTRODUCTION: Zinc is an essential element for the proper functioning of the body at all stages of life, both for cell synthesis, tissue repair and brain development to growth. Cofactor of numerous enzymes (lactate dehydrogenase, alkaline phosphatase, carbonic anhydrase, carboxypeptidase, SOD, etc.), being very important for the functioning of the prostate, development of reproductive organs for proper functioning of the retina, and is involved in the regeneration of rhodopsin. The immune system requires Zn and is necessary for maintaining the structural integrity of DNA and the synthesis of nucleic acids and proteins. OBJECTIVE: The objective is to study the nutritional status of zinc in a healthy population and establish relationship with other factors such as exercise, alcohol consumption, and other biochemical parameters such as GOT, ALP, CPK, ALSO immunoglobulin G, immunoglobulin A, alpha 1antitrypsin, lactate dehydrogenase, rheumatoid factor. METHODS: The study was conducted in a group of people from 21 to 59 years, 56 men and 61women. Inclusion criteria were based on the acceptance of subjects to participate in the study and that these subjects did not display any pathology that could affect their nutritional status. Zn was analyzed by Atomic Absorption Spectrometry (AAS) in blood cells and plasma samples mineralized by wet. We applied a food frequency questionnaire, and through software Nutriben (Mataix, and Garcia Diz, 2006) won the% RDA. It was accepted by the Ethics Committee and informed consent. The clinical parameters analyzed were determined on a computer Hitachi autoanalyzer using a colorimetric method. RESULTS: The recommended intake of Zn in the adult population is 7 to 15 mg/d. Our results show that Zn intake below 2 / 3 of the RDA in 56% of individuals studied. In plasma, Zn deficiency occursin 17%. There was a significant positive correlation between Zn levels and alcohol consumption, levels of GOT, ALP, CPK, ASO, Immunogen, Inmuno A and alpha-1-antitrypsin, and negative with exercise intensity, LDH and rheumatoid factor CONCLUSION: According to the results, it is necessary to control both the intake and plasma and cellular levels of Zn for the population are deficient in this mineral that lead to the development of numerous diseases, as demonstrated by the association found with immunological and clinical parameters that affect enzymatic cell integrity (AU)

Imaging skin: past, present and future perspectives.

Skin imaging modalities relevant to the range of skin conditions encountered in clinical settings are described with respect to the information provided, advantages and limitations, current status and indications for further development. The methods use the interaction of energy with the skin, penetrating to various depths in the stratum corneum, epidermis, dermis and subcutaneous layers. They include a detection system such as the retina, film or a digital array, and a processing system to deconstruct, analyze and interpret the information. Similarly, the areas of interest, or targets, have common features. The skin conditions deviate from the ideal or normal state with respect to skin integrity and function. The deviations include evidence of barrier disruption, inflammation, dispigmentation, and vascular change. The user of skin imaging is often interested in the extent and severity of disease. Part of the task in skin imaging is to establish the criteria for the normal condition. The review encompasses the past, present and future of visual assessment, photographic image collection, spectrophotometric techniques, noninvasive histology, and three dimensional scanning. The analytical techniques for processing and extracting specific parameters that inform about the underlying biological status are presented.

Hemólisis en las muestras para diagnóstico / Hemolysis in diagnostic samples

La hemólisis es un efecto preanalítico evitable en la mayoría de los casos. Su aparición se debe a la técnica de extracción empleada y a las condiciones de transporte y preparación de las muestras. Su presencia produce error en muchas determinaciones habituales en química clínica, en muchos casos por la mezcla del contenido intraeritrocitario y en algún caso por el efecto interferente de componentes del hematíe, como la hemoglobina. En los laboratorios es necesario detectar y cuantificar la hemólisis en las muestras de forma estandarizada. La mayoría de los analizadores de bioquímica actuales incorporan sistemas de cuantificación espectrofotométrica de la hemoglobina. La influencia de la hemólisis en una magnitud depende de la metodología empleada, por lo que se debería solicitar a los fabricantes de equipos la realización de estudios y una información detallada sobre la influencia de la hemólisis en sus determinaciones, para que cada laboratorio pueda establecer el grado de hemólisis que supone error significativo para una magnitud, de acuerdo con sus especificaciones de calidad (AU)

In most cases, hemolysis is an avoidable preanalytical effect. It can appear as a result of the procedure used during blood specimen collection and also due to transport conditions and sample preparation. Hemolysis can lead to errors in many common determinations in clinical chemistry, mostly due to the leakage of cellular contents into the plasma, and in some cases, by the interfering effect of red blood cells components, such as hemoglobin. Laboratories need to be able to detect and measure hemolysis by a standardized procedure. The majority of current biochemistry analyzers can measure hemolysis by a spectrophotometric method. Nevertheless, the influence of hemolysis depends on the measurement method employed. Laboratories should demand that manufacturers give detailed information and make exhaustive studies regarding the influence of hemolysis on each analyte. This would allow each laboratory to establish the degree of hemolysis that produces a significant error in an analysis and in accordance with the laboratory's quality specifications (AU)

Diagnóstico de la hemorragia subaracnoidea espontánea de escasa cuantía o de larga evolución: a propósito de un caso / Diagnosis of the spontaneous subarachnoid hemorrhage with short bleeding or long evolution: report of one case

La hemorragia subaracnoidea implica la presencia en el espacio subaracnoideo de sangre proveniente de un proceso patológico. La prueba inicial de elección es una Tomografía Axial Computerizada craneal urgente, pero su sensibilidad disminuye con el tiempo. Se recomienda, por tanto, que a los pacientes con una cefalea brusca severa, pero con unaTomografía Axial Computerizada craneal normal, se les debería practicar una punción lumbar, después de las primeras 12 horas del comienzo de los síntomas, para descartar una hemorragia subaracnoidea. Los métodos para diferenciar entre una punción lumbar traumática y una verdadera hemorragia subaracnoidea incluye el recuento de hematíes, “la prueba de los tres tubos”, el dímero-D y la ferritina en líquido cefalorraquídeo. Pero la mejor técnica es la xantocromía ó sobrenadante amarillo naranja en líquido cefalorraquídeo, valorado por espectrofotometría. Presentamos el caso de una mujer joven con una hemorragia subaracnoidea diagnosticada mediante xantocromía tras 18 días del comienzo del sangrado

Subarachnoid hemorrhage implies the presence of blood within the subarachnoid space from some pathologic process. The initial study of choice is an urgent Cranial Computed Tomography scan, but its sensitivity declines with time. So that it is recommended that patients with severes udden headache but normal Cranial Computed Tomography scan, should have a lumbar puncture performed, more than 12 hours after the onset of symptoms, to rule out subarachnoid hemorrhage. The methods for distinguishing among traumatic lumbar puncture and true Subarachnoid hemorrhage include the erythrocyte level, the“three tube test”, D-dimer assay and ferritin in cerebrospinal fluid. But the best technique is the xanthochromia o yellow-to-orange cerebrospinal fluid supernatant, measured spectrographically. We report a case of a young woman with a subarachnoid hemorrhage diagnosed by xanthochromia after 18 days after the onset of bleeding

Diseño y evaluación de matrices de difusión controlada en parches transdérmicos de clorhidrato de Diltiazem / Design and evaluation of matrix diffusion controlled transdermal patches of diltiazem hydrochloride

Se desarrolló un sistema matricial de tipo dispersivo para la administración transdérmica de clorhidrato de Diltiazemusando diferentes proporciones de colofonia con Eudragit RL PM y polivinil pirrolidona. El parche preparado concolofonia y polivinil pirrolidona no era transparente y muestra una distribución irregular de polivinil pirrolidona,lo que puede ser debido al carácter hidrófi lo de ésta. Se investigó el efecto de los polímeros sobre las propiedadestecnológicas; es decir, la liberación del fármaco, la velocidad de transmisión del vapor de agua, la pérdida porcentualde humedad y el grosor. El parche con colofonia: Eudragit RL PM (6:4) dio como resultado una liberaciónde 2651 mcg en 24 horas. Con el objeto de mejorar la liberación, se incluyeron distintas proporciones de alcanforen la formulación. El parche con colofonia: Eudragit RL PM (6:4) y un 5% p/v de alcanfor dio como resultadouna liberación constante del fármaco a lo largo de un período de 24 horas. La formulación F8 resultó ser la mássatisfactoria en lo que a las propiedades tecnológicas se refi ere. Se llevaron a cabo estudios posteriores de permeacióne irritación de la piel en ratas y conejos respectivamente. Por lo tanto, se puede concluir que con el parchede colofonia: Eudragit RL PM en proporción 6:4 con un 5% p/v de alcanfor, se alcanzan los objetivos deseablesen sistemas de administración transdérmica de fármacos tales como anular el efecto de primer paso, una amplialiberación y una frecuencia de administración reducida

A matrix dispersion type transdermal drug delivery system of Diltiazem Hydrochloride was developed using differentratios of rosin with Eudragit RL PM and polyvinyl pyrrolidone. The patch prepared by the combination of rosin andpolyvinyl pyrrolidone was not transparent one, and shows an uneven distribution of polyvinyl pyrrolidone, which maybe due to the hydrophilic nature of polyvinyl pyrrolidone. The effect of the polymers on the technological properties,i.e., drug release, water vapor transmission rate, percentage moisture loss and thickness were investigated. The patchcontaining rosin: Eudragit RL PM (6:4) showed a release of 2651 mcg in 24 h. In order to improve the release variousproportions of camphor was included in the formulation. The patch containing rosin: Eudragit RL PM (6:4) with5% w/v of camphor showed a sustained release of the drug extending over a period of 24 h. Formulation F8 emergedas the most satisfactory formulation as far as the technological properties were concerned. Further skin permeationand skin irritation studies were carried out on rat skin and rabbit respectively. Therefore it can be concluded that thepatch containing rosin: Eudragit RL PM in the ratio 6:4 with 5%w/v of camphor achieved the desired objectives oftransdermal drug delivery systems, such as overcoming of fi rst pass effect, extended release and reduced frequency ofadministration

Spectrophotometric characterisation of the Cu(II):PPi system: implementation as a method for measuring pyrophosphate (PPi) in solution

El pirofosfato (PPi) tiene una importante función en numerosos procesos biológicos. Participa en muchas reacciones enzimáticas catalizadas por transferasas, hidrolasas, ligasas o sintetasas. La interacción en solución del Cu(II) con pirofosfato (PPi) modifica el espectro de absorción del catión. Se describen las interacciones químicas involucradas en el cambio de absorbancia, se identifican los coeficientes de absorción de las diferentes especies en solución y proponemos un modelo del sistema químico Cu(II)-PPi. Ya que los cambios en el espectro de absorción son dependientes de la concentración, nosotros proponemos un método para cuantificar PPi en soluciones acuosas basado en la modificación del espectro de absorción de Cu(II) en presencia PPi. Los cambios en la absorción pueden ser monitorizados y utilizados para cuantificar PPi en solución. La determinación es simple, rápida y barata. El límite de detección del método es 0,1 ìmol de PPi en las condiciones del ensayo. Además es posible usar este método en sistema biológicos que contienen proteínas, nucleótidos, EDTA o magnesio

The interaction of Cu(II) with pyrophosphate (PPi) in solution modifies the absorption spectrum of the cation. We provide here a proper description of the chemical interactions involved in the absorbance shift, identify the absorption coefficients of the species in solution and afford a model of the Cu(II)-PPi chemical system. Since the changes in the absorption spectrum are concentration dependent, we describe a new method for quantifying PPi in aqueous solutions, based on the modification of the Cu(II) absorption spectrum in the presence of PPi. Changes in absorptivity can be monitored and used to quantify PPi in solution. The determination is simple, fast and cheap. The detection limit of the method is 0.1 ìmol of PPi in the assay conditions. The presence of orthophosphate does not interfere in the determination of PPi. Furthermore, it is possible to use this method in biological systems containing proteins, nucleotides, EDTA or magnesium

Spectrophotometric and colorimetric determination of protein concentration.

This unit describes spectrophotometric and colorimetric methods for measuring the concentration of a sample protein in solution. Absorbance measurement at 280 nm is used to calculate protein concentration by comparison with a standard curve or published absorptivity values for that protein. An alternate protocol uses absorbance at 205 nm to calculate the protein concentration. Both methods can be used to quantitate total protein in crude lysates and purified or partially purified protein. Use of a spectrofluorometer or a filter fluorometer to measure the intrinsic fluorescence emission of a sample solution is also described. The measurement is compared with the emissions from standard solutions to determine the concentration of purified protein. The Bradford colorimetric method, based upon binding of the dye Coomassie brilliant blue to an unknown protein, is also presented, as is the Lowry method, which measures colorimetric reaction of tyrosyl residues in an unknown.

Microspectrophotometry for structural enzymology.

For several decades, single-crystal microspectrophotometry has contributed to structural enzymology as a very useful complement to X-ray crystallography. In its most recent applications, it is the ideal tool to track chemistry as structure evolves in the course of time-resolved experiments, to identify freeze-trapped catalytic intermediates and to assess radiation-induced effects on enzyme crystals. To these goals, instruments have been developed to record optical spectra 'on-line' in the course of X-ray data collection, whereas more rigorous polarized absorption studies 'off-line' play an essential role in describing what protein function is retained in the crystalline state and correlating it with the observed structures.

Spectrophotometric determination of some beta-blockers in dosage forms based on complex formation with Cu(II) and Co(II).

Four sensitive and accurate spectrophotometric methods have been developed for the assay of Acebutolol Hydrochloride (ACH), Atenolol (ATE) and Propranolol Hydrochloride (PRH), which are based on the complexation of drugs with copper(II) (Cu(II)) and cobalt(II) (Co(II)). The coloured products are measured at 613, 694, 548 and 614 nm for ACH-Co(II), ATE-Cu(II), PRH-Cu(II) and PRH-Co(II) method, respectively. The optimization of various experimental conditions is described. Conformity with Beer's Law was evident over a concentration range in the of 2 x 10(-5) - 1 x 10(-2) mol/L. The molar absorptivity, detection and quantification limits are calculated. The results obtained showed good recoveries of 100.2 +/- 1.1, 100.3 +/- 1.2, 100.75 +/- 1.0 and 99.55 +/- 1.1 % with relative standard deviations of 0.410, 0.490, 0.161 and 0.140 % for ACH-Co(II), ATE-Cu(II), PRH-Cu(II) and PRH-Co(II) method, respectively. They were applied to the analysis of tablet forms of the drugs and the results were statistically compared with those obtained by official and literature methods using t- and F-tests. There were no significant difference among the mean values and precisions of the methods at 95% confidence level.

The use of the new SPE methods for isolation of some tricyclic antidepressant drugs from human serum.

Solid-phase extraction (SPE) methods were applied to isolation of amitriptyline (AMI), imipramine (IMI) and chlorprothixene (CPX) from blood human serum. SPE was carried out using the octadecyl (C(18)) column for isolation of AMI and cyclohexyl (CH) columns in the case of IMI and CPX. The spiked serum samples were used to examine the recoveries of these drugs from C(18) and CH sorbent materials. The volume of serum sample was 500 microl. The recoveries of SPE method using CH cartridge were 100.3+/-1.63% (n=7), 99.7+/-2.3% (n=9) for IMI and CPX, respectively. The recovery of AMI from C(18) cartridge was 99.5+/-1.5% (n=8). Finally, after SPE sample clean-up step the antidepressant drugs were assayed by the own extractive-spectrophotometric methods.

Modificación de los mediadores inflamatorios en isquemia-reperfusión intestinal en un modelo de diabetes tipo 2 / Modification of inflammatory mediators in intestinal ischemia-reperfusion in a model of type II diabetes

Introducción. Se ha demostrado que los polimorfonucleares aislados de pacientes diabéticos presentan un mayor grado de activación que los de los pacientes no diabéticos. Además, la diabetes, tanto de tipo 1 como de tipo 2, se asocia con un incremento de la peroxidación lipídica y valores elevados de moléculas de adhesión circulantes. La administración de estreptozotocina (STZ) en ratas neonatales conduce en las ratas adultas a una ligera deficiencia de insulina, con valores de glucemia normales, y son aceptadas como modelo de diabetes tipo 2.Objetivo. En este estudio hemos investigado posibles diferencias en plasma y tejidos de algunos mediadores de la inflamación entre ratas normales y ratas con diabetes tipo 2, después de isquemiareperfusión (I-R) intestinal. Material y métodos. Se utilizaron ratas Wistar a las que se les administró STZ (0 o 30 mg/kg) el día de su nacimiento. Dos meses después, tanto las ratas control como las que tenían diabetes tipo 2 (normoglucémicas) fueron asignadas aleatoriamente a dos grupos. El grupo I fue sometido a un período de 60 min de isquemia intestinal por pinzamiento de la arteria mesentérica superior. Cinco minutos después de la reperfusión, las ratas fueron sacrificadas y se obtuvieron muestras de vena porta (VP), cava infrahepática (CIH), cava suprahepática (CSH), páncreas e intestino. En el grupo control los animales se manipularon de igual forma, pero sin ser sometidos a IR. El óxido nítrico (NO) se midió como NO-2 + NO-3, por la reacción de Griess. Los hidroperóxidos lipídicos (LPO) fueron determinados espectrofotométricamente usando un kit comercial. Los receptores para factor de necrosis tumoral (TNF) de 60 kDa (TNF-R1) y 75 kDa (TNF-R2), y el ICAM-1 se determinaron por el método Elisa. Resultados. Tras la I-R, las ratas diabéticas evidenciaron un aumento de las concentraciones plasmáticas de LPO, NO, ICAM-1 (0,514 + 0,083 frente a 0,046 + 0,011 CIH; 0,574 + 0,075 frente a 0,037 + 0,009 CSH, y 0,528 + 0,067 frente a 0,033 + 0,009 VP; ng/ml; n = 10; p < 0,01), TNF (42,4 + 5,7 CIH, 248,4 + 28,2 CSH y 33,6 + 4,0 VP, pg/ml, en ratas diabéticas frente a no detectable en ratas control; n = 10), TNF-R1 (0,179 + 0,024 frente a 0,023 + 0,011 CIH; 0,233 + 0,032 frente a 0,033 + 0,005 CSH; 0,206 + 0,034 frente a 0,039 + 0,023 VP; ng/ml; n = 10; p < 0,001; p < 0,05 todas) mientras que no se encontraron diferencias en los valores de TNF-R2 entre ambos grupos. Tras I-R, los valores plasmáticos de TNF y NO fueron más elevados en CSH que en CIH y VP, lo que sugiere que el hígado es una importante fuente de ambos mediadores. Hemos observado que tras I-R en ratas diabéticas en el tejido intestinal se produce un aumento en los valores de TNF, interleucina (IL) 1, IL-6 (no significativo) e IL-10, mientras que en el tejido pancreático hay una disminución de TNF- e IL-10 y un aumento de IL-1 e IL-6.Conclusión. La diabetes tipo 2 intensifica la respuesta inflamatoria a la I-R intestinal (AU)

Jet nebulizadores: cambios en el débito y en la concentración de la solución durante la nebulización con aire u oxígeno / Jet nebulizers: changes in the aerosol outpout and the solution concentration during the nebulization with air or oxygen

Objetivo: medir los cambios en la concentración de la solución nebulizante y en el débito (volumen de solución liberado) po rlos nebulizadores jet al emplear aire y oxígeno. Diseño: Estudio experimental. Material y métodos: Siete nebulizadores jet fueron cargados con 4 ml de fluoruro de sodio 1 por ciento y operados con un flujo de aire u oxígeno de 8l/minuto en forma aleatoria. Mediante gavimetría y espectrofotometría se determinaron el débito y la concentración, respectivamente. Los valores obtenidos se compararon mediante pruebas no paramétricas. Resultados: La concentración de la solución aumentó significativamente durante la nebulización (p<0.05); no hubo diferencias significativas en las concentraciones de los 2 y 5 minutos al emplear aire u oxígeno y los débitos fueron significativamente más altos con oxígeno. Conclusiones: Al emplear nebulizadores jet con aire u oxígeno la cantidad de soluto (medicamento) en el aerosol disminuirá significativamente durante la nebulización y el débito del nebulizador calculado por gravimetría no refleja adecuadamente el comportamiento de la concentración de la solución durante el proceso

Optical biosensors. A bright future.

Progress in fibre-optic technology, laser miniaturization, and the reproducible manufacture of prisms and wave guides has made the commercial exploitation of optical biosensors possible. Some optical biosensors are miniaturized versions of traditional spectrophotometers, others are based on new integrated-optic methods. This article reviews the achievements already made in this area and the opportunities for the future.