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A new, simple and selective method for the analysis of 5-hydroxymethylfurfural (HMF) in foods by gas chromatography coupled to mass spectrometry (GC-MS) is proposed. Several derivatising procedures based on the formation of an HMF silylated derivative using different reagents were studied. Among the derivatising reagents examined, N,O-bis-trimethylsilyltrifluoroacetamide (BSTFA) provided the best derivatisation yield. Sample clean-up was also optimised, using either liquid-liquid extraction with dichloromethane or solid-phase extraction (SPE) with several commercially available cartridges, and the best results were obtained using ENV+ cartridges. Quality parameters such as day-to-day and run-to-run precision (RSD<10%), linearity (between 25 and 700 ng g(-1)) and detection limit (6 ng g(-1)) were established. This method was successfully applied to the analysis of HMF content in several Spanish food samples from a local market, such as jam, honey, orange juice and bakery products.

Polychlorinated n-alkanes (PCAs), also known as chlorinated paraffins (CPs), are highly complex technical mixtures that contain a huge number of structural isomers, theoretically more than 10,000 diastereomers and enantiomers. As a consequence of their persistence, tendency to bioaccumulation, and widespread and unrestricted use, PCAs have been found in aquatic and terrestrial food webs, even in rural and remote areas. Recently, these compounds have been included in regulatory programs of several international organizations, including the US Environmental Protection Agency and the European Union. Consequently, there is a growing demand for reliable methods with which to analyze PCAs in environmental samples. Here, we review current trends and recent developments in the analysis of PCAs in environmental samples such as air, water, sediment, and biota. Practical aspects of sample preparation, chromatographic separation, and detection are covered, with special emphasis placed on analysis of PCAs using gas chromatography-mass spectrometry. The advantages and limitations of these techniques as well as recent improvements in quantification procedures are discussed.

6alpha,7beta-Dihydroxyvouacapan-17beta-oic acid (1) was isolated from Pterodon polygalaeflorus Benth. Modification of 1 yielded 6alpha-hydroxyvouacapan-7beta,17beta-lactone (2) and then 6-oxovouacapan-7beta,17beta-lactone (3). Photosynthesis inhibition by 3 was evaluated in spinach chloroplasts. The uncoupled non-cyclic electron transport rate and ATP synthesis were inhibited by 3, which behaved as a Hill reaction inhibitor. Furthermore, 3 acted as an uncoupler because it enhanced the basal and phosphorylating electron transport rate on thylakoids. This last property of 3 was corroborated when it was observed that it enhances the Mg2+-ATPase activity. In contrast, 3 did not affect photosystem I (PSI) activity. Analysis of the partial photosystem II (PSII) reactions from water to DCPIPOX and water to silicomolybdate allowed to locate the inhibition sites at the redox components of PSII. The OJIP test of the chlorophyll a fluorescence transient confirmed that the inhibition sites were 1.) the oxygen-evolving complex (OEC) and 2.) by the formation of silent centers in the non-QA reducing centers.

Background: The aim of this study was to determinate the relative frequency of odontogenic tumors (OTs) in a Brazilian population and to compare this data with previous reports., Methods: We reviewed the achieves of 19 123 specimens from oral pathology laboratory of Universidade Federal de Minas Gerais, from 1954 to 2004. Using the criteria of histologic typification published by the World Health Organization in 1992, we classified the OTs., Results: A total of 340 OTs were found. The frequency of OTs comprises 1.78% of all pathologic specimens in our laboratory. The most frequent tumor was ameloblastoma (45.2%), followed by odontomas (24.91%), and myxomas (9.1%)., Conclusions: Odontogenic tumors are uncommon lesions in this Brazilian population and malignant OTs are very rare. The relative frequency of various types of OTs, age, and gender distribution are similar to those reported in African, Asian but not to Chilean and North American series.

Comprehensive two-dimensional gas chromatography with electron-capture negative ionization time-of-flight mass spectrometry (GC x GC-ECNI-TOF-MS) is used to study the composition and characteristics of short-, medium- and long-chain polychlorinated n-alkane (PCA) mixtures. Distinct ordered structures, which enable the highlighting and interpretation of group and sub-group separations are observed when using a DB-1 x 007-65HT column combination. The analysis of a number of, mutually rather different, technical mixtures and 35 individual standard compounds provides information on the role of chlorine substitution (number of substituents as well as their position), the contribution of carbon versus chlorine atoms to analyte volatility, i.e. GC x GC behaviour, and the influence of the chain length of the carbon skeleton. Two dust samples are analyzed to illustrate the practical usefulness of the proposed procedure.

In this work we present results of the (129)I/(127)I ratio in aerosols of Seville, Southwest of Spain (37.4 degrees N,6 degrees W). A radiochemical method is applied to extract the iodine from the aerosols and prepare samples to be measured by accelerator mass spectrometry (AMS) at the ETH facility in Zürich. We have found the possibility of monitoring the (129)I/(127)I isotopic ratio on a two-days basis with sensitivities in the order of 10(4)-10(5) atoms (129)I/m(3), and values of 10(-8)-10(-9) for the isotopic ratio.

Gas chromatography coupled with ion trap tandem mass spectrometry (GC-MS-MS) has been compared to gas chromatography-high-resolution mass spectrometry (GC-HRMS) for the analysis of non-ortho-chlorinated biphenyl (CB) congeners in fish samples. The MS-MS operating parameters related to the isolation and fragmentation of the precursor ions by resonant collision induced dissociation (CID) were optimised in order to achieve maximum sensitivity and selectivity. Analytical procedure consisting of Soxhlet extraction, clean-up using a multilayer silica column and the isolation of the target compounds with SPE commercial carbon cartridges packed with Carbopack B has been applied. Quality parameters have been established using standard solutions and fish samples. Good repeatability, long-term precision (lower than 10%), and limits of detection between 0.12 and 0.16 pg g(-1) were obtained. The effect of potential interfering compounds such as polychlorinated naphthalenes in the quantification of non-ortho-CBs has been investigated. Using selective CID fragmentation conditions, the effect of these compounds was minimised. The GC-MS-MS method was validated by comparing the results with those obtained in two European intercomparison exercises.

Microwave-assisted extraction (MAE) was evaluated as a possible alternative to Soxhlet extraction for analysing short-chain chlorinated alkanes (commonly called short-chain chlorinated paraffins, SCCPs) in river sediment samples, using gas chromatography coupled to negative chemical ionisation mass spectrometry. For MAE optimisation, several extraction parameters such as solvent extraction mixture, extraction time and extraction temperature were studied. Maximum extraction efficiencies for SCCPs (90%) and for 12 polychlorinated biphenyl (PCB) congeners (91-95%) were achieved using 5 g of sediment sample, 30 ml of n-hexane-acetone (1:1, v/v) as solvent extraction, and 15 min and 115 degrees C of extraction time and temperature, respectively. Activated Florisil was used to clean-up the extracts, allowing highly selective separation of SCCPs from other organic contaminants such as PCBs. MAE was compared with a conventional extraction technique such as Soxhlet and good agreement in the results was obtained. Quality parameters of the optimised MAE method such as run-to-run (R.S.D. 7%) and day-to-day precision (R.S.D. 9%) were determined using spiked river sediment samples, with LODs of 1.5 ng g(-1). This method was successfully applied to the analysis of SCCPs in river sediment samples at concentrations below the ng g(-1) level. O 2004 Elsevier B.V. All rights reserved.

The present paper describes the preparation of a suitable laboratory reference material (LRM) to validate analytical methods for the determination of heterocyclic amines (HAs) in foods. Three different lots of reference material were prepared using a beef extract which was contaminated with a well-known quantity of amines at different levels ranging from 10 to 75 ng/g. These materials were then lyophilised under determined conditions and, after grinding and sieving, homogenised and, finally, bottled and labelled. Homogeneity and stability studies were performed and no statistical differences were observed in the analysis of variances for within- and between-bottle results, thus demonstrating the homogeneity of the material. Stability at different storage temperatures (-18, +4, +25 and +40 degrees C) and times (1, 2, 3 and 6 months) was also tested. Therefore, the material can be considered homogeneous and stable and can be proposed for use in inter-comparison exercises for the determination of HAs.

A feasibility study and two interlaboratory exercises on the determination of selected heterocyclic amines (HAs) in beef extract, organised in the framework of a European project, are presented. The aim of these exercises was to improve the quality of the laboratories and to evaluate the performance of a standardised analytical method and also the methods currently used by each of the participants for the analysis of these compounds. Three lyophilised portions of a commercial beef material previously spiked with HAs at different concentration levels ranging from 10 to 75 ng g(-1) were used as laboratory reference materials (lot A, B and C). Firstly, a feasibility study was carried out using a test standard solution and the beef extract (lot A), which contained only five HAs. Then, two interlaboratory exercises were carried out using the laboratory reference materials lot B and lot C, containing 10 selected HAs at two different concentration levels, 75 and 10 ng/g, respectively. The results obtained by all participant laboratories using the proposed method showed satisfactory agreement and the CV(%) between-laboratories obtained were from 8.3 to 24.1% for lot B and from 8.7 to 44.5% for lot C. The standardised method evaluated in these collaborative studies is therefore proposed for the analysis of HAs in food material. Moreover, LC-MS is recommended as the most suitable technique for the analysis of a large number of HAs in food samples.

Solid-phase extraction (SPE) and solid-phase microextraction (SPME) were evaluated for the analysis of short-chain chlorinated paraffins (SCCPs) in water samples using gas chromatography coupled to negative chemical ionisation mass spectrometry (GC-NCI-MS). For SPE optimisation, four commercially available SPE cartridges were tested and several SPE parameters, such as the elution solvent, elution volume and breakthrough volume were studied. The best results were obtained with Varian Bond Elut-C18. In order to achieve a high selectivity in the determination of SCCPs, GC-NCI-MS was used. Quality parameters of the optimised SPE and SPME procedures were determined, and the best results were obtained for the SPE/GC-NCI-MS method with LODs of 5 and 20 ng l(-1) for tap and river water, respectively. This method was successfully applied to the analysis of SCCPs in river water samples at concentrations below the microg l(-1) level.

The applicability of three ionisation modes to the analysis of short-chain chlorinated paraffins (SCCPs) using gas chromatography coupled with mass spectrometry (GC/MS) was evaluated. MS conditions for electron ionisation (EI), positive chemical ionisation (PCI) and electron-capture negative ionisation (ECNI) were optimised using commercially available individual tetra-, penta- and hexachlorodecanes. In addition, mass spectra were studied and fragmentation pathways were proposed for each individual congener. Different fragment ions were evaluated for quantification, and ECNI-MS using [HCl2](-) and [Cl2](-*) ions was selected for the determination of SCCPs. Quality parameters (repeatability, limits of detection and calibration range) were established for the proposed method, which was then applied to the analysis of SCCPs in river sediments., (Copyright 2004 John Wiley & Sons, Ltd.)

Lichen planus is a mucocutaneous disease of inflammatory nature and unknown etiology. It is characterized by a cell-mediated immunological response to induced antigenic change in skin and/or mucosa. The possible malignant transformation of lichen planus remains a subject of controversial discussions in the literature. hMSH2 is one of the human DNA mismatch repair (hMMR) genes and it plays an important role in reducing mutation and maintaining genomic stability. hMSH2 alterations have been reported in oral squamous cell carcinoma and there are evidences suggesting the association between oral lichen planus and squamous cell carcinoma. In this study, we aim to investigate the immunolocalization of hMSH2 protein in oral lichen planus compared to oral normal mucosa epithelium. We examined the expression of hMSH2 protein by immunohistochemistry in twenty-six cases of oral lichen planus. Clinically, 12 of them were categorized into reticular subtype and 14 were atrophic/erosive. Ten cases of normal mucosa were added to the control group. Results showed that the percentage of positive cells to hMSH2 was smaller in reticular (46.54%; p=0,006) and atrophic/erosive (48.79%; p=0,028) subtypes of oral lichen planus compared to normal mucosa (61.29%). The reduced expression of hMSH2 protein in oral lichen planus suggests that this lesion is more susceptible to mutation and therefore facilitate the development of oral squamous cell carcinoma.

Objective: The purpose of this study was to determine the immunolocalization of the interleukin (IL) 4, IL-6, and lymphotoxin (LT) alpha in dental granulomas and correlate their expression with the intensity of the inflammatory infiltrate. Study design Fifteen paraffin specimens of dental granulomas were selected, and the streptavidin-biotin complex stain was used to detect IL-4, IL-6, and LT-alpha., Results: Our results revealed a significant statistical correlation between the intensity of inflammatory infiltrate and the percentage of mononuclear cells positive for IL-4. Moreover, we observed a statistically significant correlation between the frequency of cells expressing IL-6 and LT-alpha., Conclusion: These data suggest that the predominance of a helper T cell subtype 2 response in dental granulomas is correlated with the exacerbation of the inflammatory reaction and its evolution. Moreover, a correlation between the frequency of IL-6-positive and LT-alpha-positive cells suggests that the synergistic activities of these 2 cytokines may be involved in the pathogenesis of this inflammatory condition.

A two-step supercritical fluid extraction (SFE) method has been developed for the analysis of oxygenated and nitrated polycyclic aromatic hydrocarbons (oxy- and nitro-PAHs, respectively) present in urban aerosol samples. The proposed SFE procedure first involves an extraction step using pure CO2 in order to remove the less polar compounds from the matrix and a second consecutive step using toluene-modified CO2. The oxy- and nitro-PAHs are obtained in the second step. Parameters affecting both collection efficiencies and the selective extraction of oxy- and nitro-PAHs in the second SFE step were optimised. Analysis of the extracts was performed using gas chromatography with electron-capture detection and coupled to mass spectrometry. The proposed SFE method was compared with a conventional extraction technique such as sonication and good agreement in the results was obtained. Nevertheless, clean up of sonication extracts was needed, whereas no purification was necessary for SFE extracts. The SFE method was applied to the analysis of oxy- and nitro-PAHs in urban aerosol samples and 9-fluorenone, 9,10-anthraquinone, 2-methyl-9,10-anthraquinone, benzanthrone, benz[a]anthracene-7,12-dione and 1-nitropyrene were identified at concentrations ranging between 15 and 364 pg m(-3).

Gas chromatography coupled with mass spectrometry (GC-MS) continues to play an important role in the identification and quantification of organic contaminants in environmental samples. GC-MS is one of the most attractive and powerful techniques for routine analysis of some ubiquitous organic pollutants due to its good sensitivity and high selectivity and versatility. This paper presents an overview of recent developments and applications of the GC-MS technique in relation to the analysis in environmental samples of known persistent pollutants and some emerging contaminants. The use of different mass analysers such as linear quadrupole, quadrupole ion-trap, double-focusing sectors and time-of-flight analysers is examined. The advantages and limitations of GC-MS methods for selected applications in the field of environmental analysis are discussed. Recent developments in field-portable GC-MS are also examined.

A novel solid-phase microextraction (SPME) method coupled to gas chromatography with electron capture detection (GC-ECD) was developed as an alternative to liquid-liquid and solid-phase extraction for the analysis of short-chain chlorinated paraffins (SCCPs) in water samples. The extraction efficiency of five different commercially available fibres was evaluated and the 100-microm polydimethylsiloxane coating was the most suitable for the absorption of the SCCPs. Optimisation of several SPME parameters, such as extraction time and temperature, ionic strength and desorption time, was performed. Quality parameters were established using Milli-Q, tap water and river water. Linearity ranged between 0.06 and 6 microg l(-1) for spiked Milli-Q water and between 0.6 and 6 microg l(-1) for natural waters. The precision of the SPME-GC-ECD method for the three aqueous matrices was similar and gave relative standard deviations (RSD) between 12 and 14%. The limit of detection (LOD) was 0.02 microg l(-1) for Milli-Q water and 0.3 microg l(-1) for both tap water and river water. The optimised SPME-GC-ECD method was successfully applied to the determination of SCCPs in river water samples.

Liquid chromatography with atmospheric pressure chemical ionisation mass spectrometry (LC/APCI-MS), using negative ion detection in a triple quadrupole instrument, was used for the determination of chlorophenols (CPs) in environmental samples. In-source collision-induced dissociation (CID) was compared with MS/MS fragmentation. In general, less fragmentation was observed in MS/MS as compared with in-source CID, with the latter providing more intense fragment ions due to chemical ionisation. Under MS/MS conditions [M - H - HCl](-) was the main fragment ion observed for all compounds except for pentachlorophenol, which showed no fragmentation. For multiple reaction monitoring (MRM) acquisition mode, the transition from [M - H](-) to [M - H - HCl](-) was selected, leading to detection limits down to 0.3 ng injected. Direct and headspace-solid-phase microextraction (HS-SPME) were used as preconcentration procedures for the analysis of CPs in wood and in industrially contaminated soils. CPs were quantified by standard addition, which led to good reproducibility (RSD between 4 and 11%) in both SIM and MRM modes, and detection limits down to ng/g. The combination of MS/MS and in-source CID allowed confirmation of the presence of CPs in environmental samples., (Copyright 2002 John Wiley & Sons, Ltd.)

The ability of ten Bacteroides fragilis strains isolated from intestinal and non-intestinal infections, normal flora and environment to adhere to human colon carcinoma cells, Caco-2, was examined. The adherence capacity varied among the strains tested from strongly adherent (76-100%) to non- or weakly adherent (0-25%). Negative staining with Indian ink showed that all the strains were capsulated, although strain 1032 (strongly adherent and originated from bacteremia) had the highest rate of capsulated cells in the culture. All strains studied presented an electron-dense layer and no fimbrial structures in their surface after PTA negative staining. The analysis of the strains with ruthenium red showed the presence of an acidic polysaccharide and also surface vesicles in all of them. The strain 1032 presented an aggregative adherence pattern toward Caco-2 cells monolayers. It could be seen trapped by elongated microvilli and surrounded by extracellular material in the scanning electron microscope. Treatment with sodium periodate (100 mM/1 h) reduced significantly its adherence capacity and also the expression of an electron-dense layer and of the capsule, detected with PTA and Indian ink staining, respectively. We suggest that the capsular polysaccharide might mediate the adherence of the B. fragilis to Caco-2 cells.

A solid-phase microextraction method has been developed for the determination of 19 chlorophenols (CPs) in environmental samples. The analytical procedure involves direct sampling of CPs from water using solid-phase microextraction (SPME) and determination by liquid chromatography with electrochemical detection (LC-ED). Three kinds of fibre [50 microm carbowax-templated resin (CW-TPR), 60 microm polydimethylsiloxane-divinylbenzene (PDMS-DVB) and 85 microm polyacrylate (PA)] were evaluated for the analysis of CPs. Of these fibres, CW-TPR is the most suitable for the determination of CPs in water. Optimal conditions for both desorption and absorption SPME processes, such as composition of the desorption solvent (water-acetonitrile-methanol, 20:30:50) and desorption time (5 min), extraction time (50 min) and temperature (40 degrees C) as well as pH (3.5) and ionic strength (6 g NaCl) were established. The precision of the SPME-LC-ED method gave relative standard deviations (RSDs) of between 4 and 11%. The method was linear over three to four orders of magnitude and the detection limits, from 3 to 8 ng l(-1), were lower than the European Community legislation limits for drinking water. The method was applied to the analysis of CPs in drinking water and wood samples.

We report a case of transverse myelopathy in a 31 year old white man with acute lymphoblastic leukemia, subtype L3 (ALL-L3). This is a severe form of leukemia that affects children more often than adults. Less than 1% of leukemic patients develop neurologic complication in the spinal cord. The symptomatology in the present case started with back pain, flaccid paraplegia, and loss of sensibility and vegetative functions below the lesion. The etiologic diagnostic was obtained through peripheral blood study, bone marrow cytology, cerebrospinal fluid analysis and magnetic resonance image of the dorsal cord. The antileukemic treatment with specific drugs had no influence on the fatal outcome of the disease.

Nursing consultation for chronic patients forms part of the list of primary health care services for the coverage provided and due to the general public's satisfaction. However, the content and the results offered can be improved and the need to reorient this service has been proposed for quite some time. Strategies to succeed in developing a pure nursing contribution vis-a-vis our patients' health, that which we call an independent dimension in nursing, pass through the construction of a nursing vision which many of us lack as a consequence of a structured professional development along the lines of the biomedical model in which the nursing paradigm was transmitted more in the theoretical field than in the practical. By referring to Doka and Riopelle, we analyze the stages through which a patient afflicted by a physical disease passes and the tasks which he and his family should fulfill, in order to find an equivalence between these and some of the nursing diagnoses published by the North American Nursing Diagnosis Association (NANDA). The nursing diagnoses so obtained are compared to those which a panel of experts, belonging on Methodology Commission of the Malaga Sanitary District, by consensus identified as the most prevalent among this population. The degree of coincidences was high, which encourages us to continue along this vein in the nursing consultations for chronic patients.

An in situ derivatization solid-phase microextraction method has been developed for the determination of haloacetic acids (HAAs) in water. The analytical procedure involves derivatization of HAAs to their methyl esters with dimethyl sulfate, headspace sampling using solid-phase microextraction (SPME), and gas chromatography-ion trap mass spectrometry (GC/ITMS) determination. Parameters affecting both derivatization efficiency and head-space SPME procedure, such as the selection of the SPME coating, derivatization-extraction time and temperature, and ionic strength, were optimized. The commercially available Carboxen-poly(dimethylsiloxane) (CAR-PDMS) fiber appears to be the most suitable for the determination of HAAs. Moreover, the formation of HAA methyl esters was dramatically improved (up to 90-fold) by the addition of tetrabutylammonium hydrogen sulfate (4.7 micromol) to the sample as ion-pairing agent in the derivatization step. The precision of the in situ derivatization/HS-SPME/GC/ITMS method evaluated using an internal standard gave relative standard deviations (RSDs) between 6.3 and 11.4%. The method was linear over 2 orders of magnitude, and detection limits were compound-dependent, but ranged from 10 to 450 ng/L. The method was compared with the EPA method 552.2 for the analysis of HAAs in various water samples, and good agreement was obtained. Consequently, in situ derivatization/HS-SPME/GC/ITMS is proposed for the analysis of HAAs in water.

The determination of fluoride ions in water samples was accomplished by using a gradient flow titration. A standard commercial combined electrode is used in a cell configuration that combines the gradient chamber and the electrode in a single unit. The methodology developed gives results with a relative standard deviation of about 3%. The average recoveries after spiking natural samples with fluoride are in the range 100-102%. The method was used successful in determining the fluoride concentration in water samples.

Headspace solid-phase microextraction combined with gas chromatography/ion trap tandem mass spectrometry (HS-SPME/GC/ITMS/MS) was used for the analysis of 12 halobenzenes from soil samples. For MS/MS optimisation, the experiments were performed by precursor ion selection and software controlled operations. Collision-induced dissociation (CID) can be achieved by two different approaches, resonant and non-resonant excitation modes. Different results were obtained using the two approaches, and the resonant excitation mode was chosen as the best for all halobenzenes. Parameters such as the CID excitation amplitude, excitation RF storage level and CID bandwidth frequency were optimised to maximise the formation of halobenzene product ions. A 100-microm polydimethylsiloxane fibre was used for the isolation and preconcentration of the analytes. The HS-SPME/GC/ITMS/MS method was applied to the analysis of halobenzenes in an agricultural soil sample. The halobenzenes were quantified by standard addition, which led to good reproducibility (RSD between 4.7 and 9.2%) and detection limits in the low pg/g range. The method was validated by comparing the results with those obtained in a European inter-laboratory exercise., (Copyright 2000 John Wiley & Sons, Ltd.)

Since anticonvulsants have been used for treating neuralgias, an interest has arisen to experimentally test vigabatrin for its gabaergic mechanism of action. For this, 41 Wistar rats were used, and in 25 of them a constrictive sciatic neuropathy was induced (Bennet & Xie model). For testing pain symptoms, spontaneous (scratching) and evoked behaviors to noxious (46 degrees C) and non-noxious (40 degrees C) thermal stimuli were quantified. Moreover, a comparative pharmacological study of vigabatrin with other analgesic anticonvulsant drugs was also performed. The results showed a possible dose-dependent analgesic effect of vigabatrin (gamma-vinyl-GABA) on experimental neuropathic pain, as shown by the significant (p < 0.05) decreasing effect of vigabatrin on scratching and by its significant (p < 0.05) increasing effect on the latency of the right hindpaw withdrawal of the animals to noxious thermal stimulus. This was corroborated by similar findings with analgesic anticonvulsants (carbamazepine, phenytoin and valproic acid). This possible and not yet described analgesic effect of vigabatrin seems not to be opioid mediated.

Headspace solid-phase microextraction (SPME) was studied as a possible alternative to liquid-liquid extraction for the analysis of haloacetic acids (HAAs) in water. The method involves derivatization of the acids to their ethyl esters using sulphuric acid and ethanol after evaporation, followed by headspace SPME with a polydimethylsiloxane fibre and gas chromatography-ion trap mass spectrometry (GC-IT-MS). The derivatization procedure was optimized: maximum sensitivity was obtained with esterification for 10 min at 50 degrees C in 30 microl of sulphuric acid and 40 microl of ethanol. The headspace SPME conditions were also optimized and good sensitivity was obtained at a sampling temperature of 25 degrees C, an absorption time of 10 min, the addition of 0.1 g of anhydrous sodium sulfate and a desorption time of 2 min. Good precision (RSD lower than 10%) and detection limits in the ng l(-1) range (from 10 to 200 ng l(-1)) were obtained for all the compounds. The optimized procedure was applied to the analysis of HAAs in tap water and the results obtained by standard addition agreed with those of EPA method 552.2, whereas discrepancies due to matrix interferences were observed using external calibration. Consequently, headspace SPME-GC-IT-MS with standard addition is recommended for the analysis of these compounds in drinking water.

Baclofen (beta-p-chlorophenyl-GABA) has been used in humans to treat spasticity, as well as trigeminal neuralgia. Since GABA (gamma-aminobutyric acid) has been implicated in inhibitory and analgesic effects in the nervous system, it was of interest to study the effect of baclofen in experimental neuropathic pain. With this purpose, experiments were carried out in 17 neuropathic rats with constrictive sciatic injury, as described by Bennet and Xie (1988), taking as pain parameters scratching behaviour and the latency to the thermal nociceptive stimulus. The results showed that baclofen induces, in a dose-dependent manner, significant decrease (p < 0.05) of scratching behaviour and significant increase (p < 0.05) of the latency to the nociceptive thermal stimulus. The absence of antagonism of naloxone suggested a non-participation of an opioid-mediated mechanism in this analgesic effect of baclofen on experimental neuropathic pain.

Objective: To demonstrate an objective, quantitative, and sensitive method of mapping retinal fluorescein leakage into the vitreous while simultaneously imaging the retina., Methods: A prototype Zeiss confocal scanning laser ophthalmoscope was modified to obtain fluorometric measurements from 18 optical planes across the retina and cortical vitreous, separated from each other by 150 microm, and parallel to the retinal surface. After intravenous administration of fluorescein, an axial graphic of equivalent fluorescein concentration in the vitreous may be obtained from any region of interest. After correcting for fluorescence levels in the retina and choroid and plasma levels of free fluorescein, permeability values of the blood-retinal barrier to fluorescein were obtained from 1512 regions measuring 75 x 75 microm, from a total 3150 x 2700-microm area of the fundus, generating a detailed map of retinal fluorescein leakage. The method was assessed in vitro and in 7 healthy subjects who underwent scans during separate visits. Depth resolution and influence of chorioretinal fluorescence were further tested in 2 patients with multiple drusen and in 2 eyes after vitrectomy. Fourteen eyes from 7 patients with diabetes and nonproliferative retinopathy were also examined. Lateral resolution was tested in 3 diabetic eyes that underwent focal photocoagulation. Four eyes from 2 patients with diabetes and minimal retinopathy were examined at 3-month intervals. All eyes examined had less than 2 diopters of astigmatism., Results: Characteristics of the modified confocal scanning laser fluorometer included a lower limit of detection equal to 0.40 Eq ng/mL and depth precision of +/-15 microm. Values for the blood-retinal barrier permeability index in healthy subjects, measured 30 minutes after a single intravenous pulse of fluorescein (14 mg/kg), ranged from 1.3 +/- 0.4 x 10(-6) cm/s over the foveal avascular zone to 2.2 +/- 0.6 x 10(-6) cm/s over vessels in the retina. Diabetic eyes with retinopathy showed higher values, ranging from 1.4 to 15.0 x 10(-6) cm/s. Vitrectomized eyes and eyes with multiple drusen showed the validity of the correction algorithm demonstrating that measurements of fluorescence in the vitreous are not influenced by the chorioretinal fluorescence level. Argon laser photocoagulation burns placed in the diabetic retina demonstrated a lateral resolution on the order of 75 to 100 microm. Intravisit and intervisit reproducibility was +/-10.2% and +/-13%, respectively., Conclusions: This new method measures localized alterations of the blood-retinal barrier and allows for direct correlation with retinal anatomy. Its most interesting feature is the ability to map retinal fluorescein leakage while simultaneously imaging the retina. This capability is expected to improve our understanding and management of retinal disease.

A computer-actuated switch was built to control, simultaneously, two automatic titration assemblies each consisting of an electrode pair and a burette, and using only one measuring device. This switch is modular, simple and versatile allowing easy adaptation and expansion; apart from its application in multiple-titration systems, this device can also be used for standard addition analysis and multi-component analysis using ion-selective electrodes (ISE). The repeatability as well as the accuracy of the measurements made with this switch were ensured using high-quality relays, and very high electrical insulation, attained through the use of two separate printed circuit boards (pcb) of good quality and careful design of these pcbs. This low-cost multi-electrode switch is controlled through the parallel port of a PC that collects the data via an inexpensive 12-bit ADC board (8-bit ISA type), and is easily programmable in any high-level language. This type of device allows the collection of a large amount of data in relatively short periods, which can be analysed later allowing the choice of the best compromise of time versus accuracy for the study of any particular system.

Supercritical fluid extraction and liquid chromatography-electrochemical detection (LC-ECD) were used to the determination of chlorophenols in contaminated soil samples. Full factorial design experiments were used in order to optimize the extraction parameters: pressure, extraction cell temperature and percentage of modifier. Pressure and percentage of modifier (methanol) had statistically significant effects on the recovery of the chlorophenols. Good repeatability (4.9-11.8%) and reproducibility (4.9-12.5%) were achieved and low detection limits (3-150 ng g-1) were obtained. The method was validated by comparing the results with those obtained in a European intercomparison exercise.

HTLV-I infection and associated myelopathy has been reproduced experimentally in vitro and in vivo and these studies have shown the possibility of creating several lines of infective cells and of detecting minor and major clinical expressions of HTLV-I associated myelopathy in rabbits and rats.

The authors present the clinical of a male patient aged 45 years whose main complaints were loud snoring and excessive daytime sleepiness. Polysomnographic study revealed a sleep obstructive apnea syndrome with an apnea/hypopnea index of 86.5. After being treated with nasal continuous positive air pressure, (12 cm H2O), the apneas ended and sleep architecture was corrected. Physical examination also indicated the presence of an acromegaly, and therefore, the patient was subjected to endocrinological and cerebral imagiological studies; the diagnosis confirmed it as a predisposing factor to the sleep breathing disorder. A brief literature review about the incidence of sleep apnea syndrome in acromegaly is also made; the authors conclude that there is still the need for a systematic screening of sleep breathing disorders in acromegalic patients in order to optimise the treatment and prognosis of this disorders.

We describe a 41-year-old patient with adult-onset dermatomyositis who developed persistent pneumomediastinum and severe subcutaneous emphysema due to end-stage interstitial lung disease. The diagnosis of dermatomyositis was based on proximal muscle weakness, electromyographic findings of inflammatory myopathy, and positive findings on muscle biopsy. Low levels of creatine kinase elevation were found at the time of diagnosis (a form of dermatomyositis which has been associated with a poor prognosis). The patient had no signs of cutaneous vasculitis. Despite treatment with prednisone and azathioprine, she died of intercurrent gram-negative sepsis 15 months after the diagnosis of dermatomyositis.

To evaluate the diagnostic accuracy of digitized film radiography and digital teleradiology for detecting bone fractures and for studying solitary bone lesions, we examined 633 single radiographs from 373 patients (159 with solitary bone lesions, 123 with fractures and 91 without pathology). Radiographs were digitized using a commercial teleradiology workstation and transmitted to a local hospital over a standard telephone line. Images were reviewed by two groups of three experienced radiologists. Receiver operating characteristic (ROC) curves were analysed for conventional films, digitized images and transmitted teleradiology images. No significant differences were found among readers for the evaluation of bone fractures and solitary bone lesions. Teleradiology systems permit remote expert consultation, and telediagnosis therefore is a powerful tool in telemedicine.

Polychlorinated terphenyls (PCTs) have characteristics almost identical with those of polychlorinated biphenyls (PCBs) and have been used for analogous applications, but only sporadic reports of the occurrence of PCTs in the environment have been published. High-resolution gas chromatography with electron-capture detection (HRGC-ECD) and mass spectrometric detection in the selected ion monitoring mode was used to analyse samples for PCTs. The homologue distribution of Aroclor 5432, 5460, Leromoll 141 and the PCTs in samples of shellfish from the Ebro Delta (Catalonia, Spain) was established, taking into account the contribution of the [M-Cl2]+ fragments. Quantification was achieved by HRGC-ECD. Concentrations were between 790 and 3 ng/g (dry mass).

Social inequalities and health inequalities are closely related, and their reduction is the goal of international organizations and governments as well. In order to better understand the territorial distribution of social inequalities in the city of Málaga (Spain) and compare them with measured health differences, a descriptive study was done using different sources of information. Using the city's neighbourhoods as the unit of analysis, a cluster analysis was carried out based on a set of demographic, socioeconomic and standard of living indicators. This led to the configuration of six social areas within the city. In these areas, as defined by socially homogeneous criteria, diverse health indicators have been measured, leading the verification of important health differences among them. For example, clear differences in mortality rates between Area IV (socioeconomically deprived) and Area III (with a higher standard of living) are observed: the ratio between their respective "years of potential life lost" was 1.79, and between standardized mortality rates, 1.42. A similar disadvantage in low birth weight was confirmed notably so in adolescent pregnancies (five times higher). In conclusion, those areas of the city with a lower socio-economic status also had the lowest health levels.

A series of 38 "high risk" selected cases of deep venous thrombosis were studied in an internal Medicine Department. Fibrinogen-125I was used. Phlebographic verification was sought in those cases with a positive response to the fibrinogen. From the 38 cases 13 turned out to be positive; in 8 the venous thrombus was identify by venography. In two cases the dorsal venous arch could not be filled. In one case the phlebography could not be carried out. In the remaining two cases the venography did not show a thrombus but there was a pathologic fracture with hematoma and an ossifying myositis, respectively. Both cases were interpreted as false positives to the radioactive fibrinogen. One of them had suggestive clinical manifestations of deep venous thrombosis. Of the eight cases which were positive to the venography and radioactive fibrinogen only four showed a clinical picture suggestive of deep venous thrombosis. If the three cases with negative venographies are included only 36.3 percent of the patients had clinical manifestations. Among the 25 cases which were negative to the radioactive fibrinogen none of them had a clinical picture of deep venous thrombosis, although in 64 percent of them at least one of the clinical signs collected during the physical examination was positive. The correlation between fibrinogen-125I and phlebography turned out to be 80 percent.

We have studied the possible involvement of cellular cyclic AMP in theophylline-induced sugar gradient enhancement in isolated chicken enterocytes. Theophylline increases 3-O-methylglucose accumulation 3-fold after 30 min incubation. Exogenous cyclic AMP enhances sugar accumulation by 48%. Adenylyl cyclase inhibitor RMI 12 330A reduces theophylline-induced sugar gradients by 22% and theophylline-induced cyclic AMP levels by 24.5%. At the concentration used, RMI 12 330A has no effect on 3-O-methylglucose accumulation or basal cellular cyclic AMP. Since theophylline has a rapid inhibitory effect on Na+-independent sugar permeability, we conclude that the effects of the drug on sugar gradients are the result of its acting by both direct - surface membrane - and indirect - cyclic AMP mediated - mechanisms. The effect of theophylline and exogenous cyclic AMP on sugar accumulation is independent of external chloride.

Comparative results of the suppression-stimulation test by dexamethasone and chorionic gonadotropin, chromatographic separation of 17-ketosteroids, and plasma testosterone levels in the ovarian and adrenal veins, in cases of virilism in women. Thirteen patients with hirsutism and virilization were investigated as follows: 1. measurement of plasma testosterone (T) levels by radioimmunoassay (RIA) during suppression-stimulation tests by the administration of Dexamethasone (DXM) and chorionic Gonadotropin (HCG). 2. chromatographic determination of urinary 17-ketosteroids, pregnanediol (P2), and pregnanetriol (P3). An attempt was made to classify virilism as "ovarian" or "adrenal" based on the results of 1. and 2. 3. bilateral ovarian and adrenal venous catheterization through the femoral vein to measure T (RIA) levels. 4. laparotomy with bilateral wedge resections of the ovaries for therapeutic and biopsy purposes. Surgical catheterization of the ovarian veins was carried out during the operation. The results of these tests show that: a) the dynamic DXM-HCG test can be used to separate those cases in which the ovary is not involved in T formation from those in which, apparently, it is involved. b) chromatographic determination of urinary steroids has no aetiological value, as the variations in the different fractions are not significant. c) in all patients, the principal source of T is the adrenals and not the ovaries, even when there is an increase in T in the ovarian efferent blood vessels.

The characteristics of the interactions between 3-O-methyl-glucose (3-OMG) and monosaccharides or leucine transport were examined on chick isolated intestinal epithelial cells. In a Na+-medium, the unidirectional influx of 1.5 mM 3-OMG was found to be already inhibited by 37.5 mM glucose and 37.5 mM leucine after 20 s incubation. In Na+-free mannitol substituted medium, either glucose, galactose or leucine (37.5 mM) inhibited the unidirectional influx of 3-OMG. Theophylline, a drug that decreases the basolateral permeability to sugars, decreased the unidirectional influx of 1.25 mM leucine in Na+-free medium but increased the steady-state uptake of the aminoacid in Na+-medium. The efflux of 3-OMG from preloaded cells into a Na+-free medium was stimulated by extracellular galactose and leucine (37.5 mM). This was inhibited by theophylline. Our results indicate that sugars and leucine interactions at the Na+-independent transport system could be produced by mutual competition for binding the same system.

The authors describe three cases of Cushing' syndrome, due to nodular hyperplasia, simple hyperplasia and adenocarcinoma respectively, and the most useful approaches (dexamethasone, metopirona, insulinic hypoglycemia, cortisol rhythm, catheterism and assessment of urinary free cortisol) for diagnosis and etiology of Cushing's syndrome.

The outcome of 63 children with non-B acute lymphoblastic leukemia treated with ALL-BFM 83 protocol is analyzed. 95% achieved complete remission with the initial treatment. For the entire group the event free survival (EFS) was 66% (+/- 9%) at 48 months. These results were close to those obtained by the BFM group. Haematological toxicity was the main adverse effect, but there where no therapy related deaths. Persistence of more than 1,000 blast cells per microl in peripheral blood after 7th days of prednisone monotherapy, and spleen size greater than or equal to 5 cm under the costal margin, were identified as independent risk factors of high significance. The EFS in patients with poor clinical response to steroids (greater than or equal to 1,000 blast/microl at day 8) was 22% (+/- 18%), instead of 69% (+/- 12%) in those with adequate response.