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1.
J Environ Manage ; 161: 21-29, 2015 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-26143082

RESUMO

As a consequence of the limited resources of underdeveloped countries and the limited interest of the developed ones, the assessment of the chemical quality of entire water bodies around the world is a utopia in the near future. The methodology described here may serve as a first approach for the fast identification of water bodies that do not meet the good chemical status demanded by the European Water Framework Directive (WFD). It also allows estimating the natural background (or reference values of concentration) of the areas under study using a simple criterion. The starting point is the calculation the World-Wide Natural Background Levels (WWNBLs) and World-Wide Threshold Values (WWTVs), two indexes that depend on the concentration of seven elements present in sediments. These elements, As, Cd, Cr, Cu, Ni, Pb and Zn, have been selected taking into account the recommendations of the UNEP (United Nations Environment Programme) and USEPA (United States Environmental Protection Agency), that describe them as elements of concern with respect to environmental toxicity. The methodology has been exemplified in a case study that includes 134 sediment samples collected in 11 transitional water bodies from 7 different countries and 4 different continents. Six of the water bodies considered met the good chemical status demanded by the WFD. The rest of them exceeded the reference WWTVs, at least for one of the elements. The estuaries of the Nerbioi-Ibaizabal (Basque Country) and Cavado (Portugal), the sea inlet of Río San Pedro (Spain), the Sepetiba Bay (Brazil) and the Yucateco lagoon (Mexico) belong to that group.


Assuntos
Monitoramento Ambiental/métodos , Sedimentos Geológicos/análise , Sedimentos Geológicos/química , Brasil , Estuários , Hidrologia/métodos , Metais/análise , Metais/toxicidade , México , Portugal , Espanha , Estados Unidos , United States Environmental Protection Agency , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade , Qualidade da Água
2.
Mar Pollut Bull ; 199: 116010, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38211539

RESUMO

Sediments sampled at the estuary of the Oka River in the biosphere reserve of Urdaibai, Spain were analyzed for trace elements. Sediments were collected at 45 points of the estuary and the concentration of 14 elements was measured. The geoaccumulation indexes (Igeo), Normalized Average Weighted Concentrations (NAWC) and mean Effect Range-Median quotients (mERMq) were calculated. The results obtained were complementary and allowed intra- and inter-estuary comparison. According to the present findings, the estuary was classified as healthy, since the anthropogenic contribution of metals and metalloids was generally small. However, shipping and fishing activities at the ports of Bermeo and Mundaka and urban and industrial wastes from Gernika were regarded as the major pollution sources. Nevertheless, only slightly contaminated and toxic sediments, especially related to Ni and Cu, were found in the towns of Gernika and Mundaka.


Assuntos
Metaloides , Metais Pesados , Poluentes Químicos da Água , Metais Pesados/análise , Metaloides/análise , Estuários , Rios , Espanha , Monitoramento Ambiental/métodos , Sedimentos Geológicos , Poluentes Químicos da Água/análise
3.
Anal Chim Acta ; 1276: 341632, 2023 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-37573113

RESUMO

In this work, a geological sample of great astrobiological interest was studied through analytical techniques that are currently operating in situ on Mars and others that will operate in the near future. The sample analyzed consisted of an oncoid, which is a type of microbialite, collected in the Salar Carachi Pampa, Argentina. The main peculiarity of microbialites is that they are organo-sedimentary deposits formed by the in situ fixation and precipitation of calcium carbonate due to the growth and metabolic activities of microorganisms. For this reason, the Carachi Pampa oncoid was selected as a Martian analog for astrobiogeochemistry study. In this sense, the sample was characterized by means of the PIXL-like, SuperCam-like and SHERLOC-like instruments, which represent instruments on board the NASA Perseverance rover, and by means of RLS-like and MOMA-like instruments, which represent instruments on board the future ESA Rosalind Franklin rover. It was possible to verify that the most important conclusions and discoveries have been obtained from the combination of the results. Likewise, it was also shown that Perseverance rover-like remote-sensing instruments allowed a first detailed characterization of the biogeochemistry of the Martian surface. With this first characterization, areas of interest for in-depth analysis with Rosalind Franklin-like instruments could be identified. Therefore, from a first remote-sensing elemental identification (PIXL-like instrument), followed by a remote-sensing molecular characterization (SuperCam and SHERLOC-like instruments) and ending with an in-depth microscopic analysis (RLS and MOMA-like instruments), a wide variety of compounds were found. On the one hand, the expected minerals were carbonates, such as aragonite, calcite and high-magnesium calcite. On the other hand, unexpected compounds consisted of minerals related to the Martian/terrestrial surface (feldspars, pyroxenes, hematite) and organic compounds related to the past biological activity related to the oncoid (kerogen, lipid biomarkers and carotenes). Considering samples resembling microbialites have already been found on Mars and that one of the main objectives of the missions is to identify traces of past life, the study of microbialites is a potential way to find biosignatures protected from the inhospitable Martian environment. In addition, it should be noted that in this work, further conclusions have been obtained through the study of the results as a whole, which could also be carried out on Mars.

4.
Anal Chim Acta ; 1209: 339837, 2022 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-35569848

RESUMO

The SuperCam instrument, onboard the Perseverance rover (Mars 2020 mission) is designed to perform remote analysis on the Martian surface employing several spectroscopic techniques such as Laser Induced Breakdown Spectroscopy (LIBS), Time-Resolved Raman (TRR), Time-Resolved Fluorescence (TRF) and Visible and Infrared (VISIR) reflectance. In addition, SuperCam also acquires high-resolution images using a color remote micro-imager (RMI) as well as sounds with its microphone. SuperCam has three main subsystems, the Mast Unit (MU) where the laser for chemical analysis and collection optics are housed, the Body Unit (BU) where the different spectrometers are located inside the rover, and the SuperCam Calibration Target (SCCT) located on the rover's deck to facilitate calibration tests at similar ambient conditions as the analyzed samples. To perform adequate calibrations on Mars, the 22 mineral samples included in the complex SCCT assembly must have a very homogeneous distribution of major and minor elements. The analysis and verification of such homogeneity for the 5-6 replicates of the samples included in the SCCT has been the aim of this work. To verify the physic-chemical homogeneity of the calibration targets, micro Energy Dispersive X-ray Fluorescence (EDXRF) imaging was first used on the whole surface of the targets, then the relative abundances of the detected elements were computed on 20 randomly distributed areas of 100 × 100 µm. For those targets showing a positive Raman response, micro-Raman spectroscopy imaging was performed on the whole surface of the targets at a resolution of 100 × 100 µm. The %RSD values (percent of relative standard deviation of mean values) for the major elements measured with EDXRF were compared with similar values obtained by two independent LIBS set-ups at spot sizes of 300 µm in diameter. The statistical analysis showed which elements were homogeneously distributed in the 22 mineral targets of the SCCT, providing their uncertainty values for further calibration. Moreover, nine of the 22 targets showed a good Raman response and their mineral distributions were also studied. Those targets can be also used for calibration purposes of the Raman part of SuperCam using the wavenumbers of their main Raman bands proposed in this work.


Assuntos
Meio Ambiente Extraterreno , Marte , Calibragem , Meio Ambiente Extraterreno/química , Minerais/análise , Análise Espectral Raman/métodos
5.
Anal Bioanal Chem ; 399(9): 2949-59, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21057778

RESUMO

A multianalytical characterisation of black crusted modern construction materials from buildings located in the Bilbao Metropolitan area (North Spain) was carried out. According to the mineral composition determined by Raman spectroscopy, calcite and hematite were the major compounds found while aragonite, limonite, rutile, quartz and some aluminosilicates such as obsidian or amazonite (KAlSi(3)O(8)) were also present in minor percentages. As deterioration products, gypsum and anhydrite were widely found not only in the surface but also in the inner part of strongly deteriorated samples. Coquimbite (Fe(2)(SO(4))(3)·9H(2)O) was identified as well in the most protected facade where high amounts of Fe, having probably an anthropogenic origin, were measured by micro X-ray fluorescence (µ-XRF). Zn was found to be in high amounts while Cu, Pb, Ti, Mn, Sr and K were identified as minor elements. Considering the non-expected concentrations found for some anthropogenic elements, a sequential extraction was carried out in order to determine their chemical form by means of ion chromatography and inductively coupled plasma mass spectrometry. The orientation of the facades, which had a different influence from rain washing and industrial and traffic impact, was shown to affect the accumulation of different compounds in the black crust. Finally, the MEDUSA software was used to simulate the reactions among the original compounds, deposited pollutants and the atmospheric acid gases in order to explain the presence of the decaying species found.

6.
Spectrochim Acta A Mol Biomol Spectrosc ; 251: 119443, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33485243

RESUMO

The landing site of the next planetary mission lead by ESA (ExoMars 2022) will be Oxia Planum. This location has been chosen due to different reasons, among them, the existence of sedimentary rocks that could host remains of organic matter. The fact that this type of rocks coexists with volcanic ones makes of high importance the study of the processes and the possible interactions that could happen among them. Therefore, in this research work the Armintza outcrop (Biscay, North of Spain) is proposed as an Oxia Planum analogue since it has the dichotomy of volcanic and sedimentary rock layers that is expected on the landing site of the ExoMars 2022 mission. As Raman and visible near infrared spectroscopies will be in the payload of the rover of that mission, they have been used to characterize the samples collected in the Armintza outcrop. With the help of these techniques, feldspars (albite mainly) and phyllosilicates (kaolinite and dickite, together with micas and chlorite minerals) have been identified as the major products on the samples, together with some weathering products (carbonates, sulphates, oxides) and apatite. Moreover, remains of kerogen have been detected in the sedimentary layers in contact with the interlayered lava flows, confirming the capability of similar sedimentary-volcanic layers to trap and store organic remains for millions of years. After establishing which compounds have volcanic or sedimentary origin, and which must be considered alteration phases, we can consider Armintza as a good Oxia Planum analogue.

7.
Talanta ; 224: 121863, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33379074

RESUMO

This work proposes an innovative non-destructive analytical strategy, based on Confocal Raman micro-spectroscopy, High Resolution Raman Imaging and micro-X-Ray Fluorescence imaging, as part of the quick non-destructive techniques that could be used to characterize the Martian samples from the Mars Sample Return mission when back on Earth. Until that moment, Martian Meteorites are the only Martian samples in our hands to develop such Analytical Strategies. To demonstrate its capabilities, this analytical strategy has been applied to characterize the Dar al Gani 735 Martian Meteorite with the aim to identify the terrestrial and non-terrestrial alterations suffered by the meteorite as a very valuable complementary methodology to the more traditional petrographic analyses and single point measurements. The combination of these techniques allows extracting at the same time elemental, molecular and structural information of the studied area of the sample. The most relevant results on the analyzed DaG 735 shergottite thick samples revealed the presence of several altered mineral phases originated from the temperature and pressure conditions during the shock on Mars (anhydride, calcite and ilmenite), as well as from terrestrial weathering processes that degraded the meteorite from its landing on Earth (calcite and hematite in fractures together with gypsum, mirabilite and thenardite). As most of the conclusive results come from Raman spectroscopy, this study shows the potential of Raman spectroscopy as a key technique in the upcoming new explorations of Mars materials by the Rosalind Franklin rover (Exomars2022 mission from ESA) and the Perseverance rover (Mars2020 mission from NASA), where Raman spectrometers are mounted for the first time in an extra-terrestrial research in the field.

8.
Arch Environ Contam Toxicol ; 59(2): 235-43, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20143053

RESUMO

From February 2004 to April 2006, the concentrations of more than 10 metals in mussels (Mytilus galloprovincialis) were measured in 10 stations from Galicia to the Basque Country in 8 different times of sampling. The mean highest concentrations are found for Zn [226.8 microg/g, dry weight (d.w.)] followed by Mn, As, Cu, and Co (between 10 and 25 microg/g d.w.). Lower mean concentrations are found for Se, Cr, Pb, V, and Ni (between 2 and 8 microg/g d.w.) and the lowest are for Cd, Sn, Hg, and Sb (between 0.05 and 1 microg/g d.w.). Among the statistical treatments used, the factor analysis showed a clustering of the mussels according to the geographical location. In addition, the temporal trend of the metal concentrations was studied by means of the Mann-Kendall test. In this sense, some stations showed a decreasing trend in the accumulation of the metallic content. However, there were some local pollution events that could be explained as a consequence of anthropogenic activities. Finally, the effects of the oil spill from the Prestige are discussed based on the experimental Ni/V ratio values obtained from this work and those of the original oil.


Assuntos
Monitoramento Ambiental , Metais/metabolismo , Mytilus/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Metais/análise , Análise Multivariada , Níquel/análise , Água do Mar/química , Espanha , Tempo , Vanádio/análise , Poluentes Químicos da Água/análise
9.
Space Sci Rev ; 216(8): 138, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33281235

RESUMO

SuperCam is a highly integrated remote-sensing instrumental suite for NASA's Mars 2020 mission. It consists of a co-aligned combination of Laser-Induced Breakdown Spectroscopy (LIBS), Time-Resolved Raman and Luminescence (TRR/L), Visible and Infrared Spectroscopy (VISIR), together with sound recording (MIC) and high-magnification imaging techniques (RMI). They provide information on the mineralogy, geochemistry and mineral context around the Perseverance Rover. The calibration of this complex suite is a major challenge. Not only does each technique require its own standards or references, their combination also introduces new requirements to obtain optimal scientific output. Elemental composition, molecular vibrational features, fluorescence, morphology and texture provide a full picture of the sample with spectral information that needs to be co-aligned, correlated, and individually calibrated. The resulting hardware includes different kinds of targets, each one covering different needs of the instrument. Standards for imaging calibration, geological samples for mineral identification and chemometric calculations or spectral references to calibrate and evaluate the health of the instrument, are all included in the SuperCam Calibration Target (SCCT). The system also includes a specifically designed assembly in which the samples are mounted. This hardware allows the targets to survive the harsh environmental conditions of the launch, cruise, landing and operation on Mars during the whole mission. Here we summarize the design, development, integration, verification and functional testing of the SCCT. This work includes some key results obtained to verify the scientific outcome of the SuperCam system.

10.
Bull Environ Contam Toxicol ; 83(2): 223-9, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19283326

RESUMO

The seasonal and spatial variability of trace metal concentrations of oyster tissues (Crassostea sps.) was studied. The samples were collected between 2002 and 2004 along the Urdaibai estuary (Murueta, Kanala and Arteaga). The seasonal influence on some metal concentrations (higher values in spring-summer season than in autumn-winter season) is more pronounced than the local site-specific influence. Furthermore, within each location a significant time-specific dependence on the trace metal concentration variations can be detected. Substantially higher concentrations of Zn (445.5-2,403.3 mg kg(-1)) and Mn (29.4-169.6 mg kg(-1)) were recorded in oysters inhabiting estuarine locations, possibly indicating a markedly higher natural bioavailability at these locations. Principal component analysis demonstrated that oysters could be separated depending on the inhabiting areas: Sn for Murueta, essential metals for Kanala, and Co and Cd for Arteaga sampling points, respectively.


Assuntos
Crassostrea/metabolismo , Monitoramento Ambiental , Metais Pesados/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Geografia , Metabolismo dos Lipídeos , Análise de Componente Principal , Rios/química , Espanha , Fatores de Tempo
11.
Folia Morphol (Warsz) ; 78(3): 626-629, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30484272

RESUMO

This project has been developed for many years in the Human Anatomy courses.Its good outcomes have been confirmed by years of evidence of excellent resultsobtained through the learning of Human Anatomy. This method of teaching andlearning as one allows students who are taking Human Anatomy classes to receivepractical training in small groups and transmit it to their colleagues in the practicaltraining established in the Medical degree. Table Leaders feel rewarded as theylearn to speak in public, regularly transmitting the knowledge obtained, and byhaving to be up to date with their studies. These are all aspects that help, not onlythe Table Leaders process of learning, but also that of their colleagues, who seeclosely and carefully anatomical details that help them understand the subject.This method of supporting practical training is always under the supervision ofthe teacher who develops the practical classes. These Leaders used to pass thetest without additional problems. Thus the note was significantly increased versusthe class colleagues.


Assuntos
Anatomia/educação , Comportamento Cooperativo , Modelos Anatômicos , Avaliação Educacional , Humanos
12.
Anal Bioanal Chem ; 391(4): 1361-70, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18265964

RESUMO

Nitrate salts have become of greater importance in the decay of materials from historical buildings due to changes in the environment. This work presents an analytical diagnosis methodology to evaluate the impact of nitrate salts in mortars and bricks, combining noninvasive and microdestructive analytical techniques together with chemometric and thermodynamic data analyses. The impact of nitrate salts cannot be well ascertained if other soluble salts are not taken into account. Therefore, the principal results from this work relate to nitrate salts but some results for other kinds of salts are included. Data from Raman microprobe spectroscopy and micro X-ray fluorescence (micro-XRF) are used to characterise the original composition and a first approximation of the nature of the decay compounds, mainly nitrates. The soluble salts are extracted and the anions and cations are quantified by means of ion chromatography with conductimetric detection for anions/cations and inductively coupled plasma mass spectrometry (ICP/MS) for cations. The values obtained allow two different data treatments to be applied. First, chemometric analysis is carried out to search for correlations among anions and cations. Second, thermodynamic modelling with the RUNSALT program is performed to search for environmental conditions of soluble salt formation. All the results are finally used to diagnose the impact of nitrates.

13.
J Chromatogr A ; 1136(1): 1-9, 2006 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-17049541

RESUMO

The headspace solid-phase microextraction (HS-SPME) of some odorous organic compounds [volatile fatty acids (VFAs), phenols and indoles] from animal wastes was optimised using an experimental design approach. The variables affecting the HS-SPME process studied were as follows: type of fibre, pH of the slurry (3-7), addition of sodium chloride (0-1 mol L(-1)), sample volume (10-30 mL), exposure time (10-30 min), exposure temperature (25-50 degrees C), desorption time (3-10 min) and desorption temperature (230-310 degrees C). As for the sorbent, three different types of fibres were studied: 50/30 microm divinylbenzene/Carboxen/polydimethylsiloxane (DVB/CAR/PDMS), 100 microm PDMS and 85 microm CAR/PDMS. Methylation VFAs was observed when fibres containing PDMS were used. The analytes studied in the optimisation procedure were acetic acid, propanoic acid, butanoic acid, 3-methylbutanoic acid, pentanoic acid, phenol, 4-methylphenol, 4-ethylphenol, indole and skatole (3-methylindole). In order to study the influence of the variables on the responses of the compounds, a Plackett-Burman design was built using the Unscrambler program. The optimisation was carried out using real samples. In order to take into account the matrix effect on the calibration curves, standard solutions were prepared using a purged cow slurry free from the analytes of interest. Repeatability within and among days, accuracy and detection limits were calculated from these calibration curves.


Assuntos
Fezes/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Compostos Orgânicos/análise , Urina/química , Animais , Calibragem , Bovinos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
14.
J Chromatogr A ; 1128(1-2): 10-6, 2006 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-16843476

RESUMO

The feasibility of different clean-up procedures was studied for the determination of polycyclic aromatic hydrocarbons (PAHs) in biota samples such as oysters, mussels and fish liver. In this sense, once the samples were extracted--essentially with acetone and in a microwave system--and before they could be analysed by gas chromatography-mass spectrometry (GC-MS), three different approaches were studied for the clean-up step: solid phase extraction (SPE), microwave-assisted saponification (MAS) and gel permeation chromatography (GPC). The main aim of this work was to maximise the recoveries of PAHs and to minimise the presence of interfering compounds in the last extract. In the case of SPE, Florisil cartridges of 1, 2 and 5 g, and silica cartridges of 5 g were studied. In that case, and with oysters and mussels, microwave-assisted extraction and 5 g Florisil cartridges provided good results. In addition, the concentrations obtained for Standard Reference Material (SRM) NIST 2977 (mussel tissue) were in good agreement with the certified values. In the case of microwave-assisted saponification, the extracts were not as clean as those obtained with 5 g Florisil and this fact lead to overestimate the concentration of the heaviest PAHs. Finally, the cleanest extracts were obtained by GPC. The method was successfully applied to mussels, oysters and hake liver, and the results obtained for NIST 2977 (mussel tissue) were within the confidence interval of the certified reference material for most of the certified analytes.


Assuntos
Fracionamento Químico/métodos , Cromatografia em Gel/métodos , Poluentes Ambientais/isolamento & purificação , Hidrocarbonetos Policíclicos Aromáticos/isolamento & purificação , Animais , Bivalves/química , Poluentes Ambientais/análise , Micro-Ondas , Ostreidae/química , Hidrocarbonetos Policíclicos Aromáticos/análise , Espanha
15.
Mar Pollut Bull ; 111(1-2): 95-105, 2016 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-27449829

RESUMO

The effects exerted by metals in oysters are still a matter of debate and require more detailed studies. In this work we have investigated whether the health status of oysters are affected by the amount of metals present in the sediments of their habitat. Sediments and oysters were collected in the tidal part of the estuary of the Oka River (Basque Country), representative of other mesotidal, well mixed and short estuaries of the European Atlantic coast. The concentrations of 14 elements were determined in all the samples. Several biomarkers were also measured in the soft tissues of oysters. According to the concentrations found, the sediments were classified as non-toxic or slightly toxic. In good agreement, the histological alterations observed in oysters were not severe. Interestingly, in those sampling sites where the sediments showed relatively high metal concentrations, the metallic content in oysters was lower, and vice versa.


Assuntos
Sedimentos Geológicos/análise , Metais/análise , Ostreidae/efeitos dos fármacos , Estresse Fisiológico/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/análise , Ecotoxicologia/métodos , Monitoramento Ambiental , Estuários , Sedimentos Geológicos/química , Metalotioneína/metabolismo , Metais/farmacocinética , Metais/toxicidade , Ostreidae/fisiologia , Rios , Espanha , Poluentes Químicos da Água/análise
16.
Arch Gen Psychiatry ; 47(3): 277-84, 1990 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-2407210

RESUMO

Lactate infusion is the most extensively studied of the pharmacological challenge tests in panic disorder. We assessed the value of this test in the diagnosis and subtyping of panic in clinical and research settings. Analysis of lactate infusion studies to date suggests that patients with panic attacks are significantly more sensitive to lactate than are healthy controls or patients with other psychiatric disorders without panic attacks. However, the usefulness of lactate infusion is limited by the lack of standardized, objective criteria for lactate-induced panic and uncertainty as to the sensitivity and specificity of the test for current, clinically significant panic attacks. Except in rare cases, the clinical history is likely to be of more value than lactate response in diagnosing panic disorder. Determination of the role of the test in subtyping patients with panic disorder awaits further study of the diagnostic, prognostic, genetic, and pathophysiologic significance of lactate sensitivity.


Assuntos
Transtornos de Ansiedade/induzido quimicamente , Medo , Lactatos , Pânico , Transtornos de Ansiedade/diagnóstico , Diagnóstico Diferencial , Infusões Intravenosas , Lactatos/administração & dosagem , Ácido Láctico , Transtornos Mentais/diagnóstico , Sensibilidade e Especificidade
17.
Arch Gen Psychiatry ; 40(5): 569-73, 1983 May.
Artigo em Inglês | MEDLINE | ID: mdl-6838334

RESUMO

There is a great interest in the potential usefulness of biomedical tests in psychiatry, but basic statistical principles required for critical evaluation of their value remain poorly integrated into clinical thinking. We developed a useful scheme for organizing clinical test data so as to permit simple calculations of the sensitivity, specificity, and predictive power of medical tests. Some loss of predictive power is inherent in moving from artificial populations used for test development into more typical clinical settings, where prevalence is usually substantially lower.


Assuntos
Técnicas de Laboratório Clínico/normas , Transtornos Mentais/diagnóstico , Técnicas de Laboratório Clínico/métodos , Reações Falso-Negativas , Reações Falso-Positivas , Humanos , Transtornos Mentais/epidemiologia , Probabilidade
18.
Arch Gen Psychiatry ; 42(12): 1193-204, 1985 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-3000317

RESUMO

A modified dexamethasone suppression test (DST) has had unprecedented evaluation among biologic tests proposed for clinical use in psychiatry. It has not proved to reflect pathophysiologic changes at the level of the central nervous system or pituitary, and tissue availability of dexamethasone itself may contribute to test outcome. The sensitivity of the DST in major depression is limited (about 44% in over 5,000 cases) but is higher in psychotic affective disorders and mixed manic-depressive states (67% to 78%). The high specificity of the DST vs control subjects (over 90%) is not maintained vs other psychiatric disorders (77% specificity overall), and acute "distress" may contribute to nonsuppression of cortisol. The test may have power in differentiating severe melancholic depression, mania, or acute psychosis from chronic psychosis (87% specificity) or dysthymia (77% specificity). The DST status adds about 11% to the prediction of short-term antidepressant response. Suggestions that failure to maintain normal suppression of cortisol predicts poor outcome are not secure. Uncritical enthusiasm or excessive skepticism regarding the DST are unwarranted.


Assuntos
Transtorno Depressivo/diagnóstico , Dexametasona , Adolescente , Hormônio Adrenocorticotrópico/sangue , Adulto , Antidepressivos Tricíclicos/uso terapêutico , Transtorno Bipolar/diagnóstico , Transtorno Depressivo/tratamento farmacológico , Transtorno Depressivo/terapia , Dexametasona/sangue , Eletroconvulsoterapia , Humanos , Hidrocortisona/sangue , Pessoa de Meia-Idade , Prognóstico
19.
Int J Oral Maxillofac Surg ; 34(6): 678-9, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16053894

RESUMO

Extensive pneumatization of the maxillary sinus can limit rehabilitation with maxillary implants. During the last 30 years, several graft addition techniques have been proposed to solve this problem. A technique without graft has been developed by the authors and the results of this technique are analyzed.


Assuntos
Seio Maxilar/cirurgia , Procedimentos Cirúrgicos Pré-Protéticos Bucais/métodos , Implantação Dentária Endóssea , Humanos , Osseointegração
20.
Biol Psychiatry ; 28(8): 733-7, 1990 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-2122917

RESUMO

The authors review over 50 reports comparing test sensitivity of the thyrotropin-releasing hormone (TRH) stimulation test using either DSM-III or Research Diagnostic Criteria (RDC) criteria for depression. Ten reports with a total of 410 patients and 458 test results were analyzed that met specific criteria for diagnosis for the TRH test. The sensitivity for depression with the TRH test in the DSM-III reports was 34.8% compared with six RDC reports in which the sensitivity was 51% (chi 2 10.41, p less than 0.001). The authors discuss possible endocrine and psychiatric implications of this finding and encourage researchers to use two methods for diagnosis in future clinical research in order that this type of comparison can be undertaken in the same patients. This will help in future modifications and revisions of the DSM.


Assuntos
Transtorno Depressivo/diagnóstico , Hormônio Liberador de Tireotropina , Tireotropina/sangue , Transtorno Depressivo/sangue , Humanos
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