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1.
Radiologia (Engl Ed) ; 63(5): 415-424, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34625197

RESUMO

In the multidisciplinary treatment of pediatric oncologic patients, multiple imaging tests, biopsies, and resections are required for diagnosis, initial staging, and posterior restaging. In these patients, pulmonary nodules are not always metastases, so the correct diagnosis of these lesions affects their treatment and the patient's survival. Percutaneous localization of pulmonary nodules is key for two reasons: it enables the surgeon to resect the smallest amount of lung tissue possible and it guarantees that the nodule will be included in the resected specimen. Without percutaneous localization, it can be impossible to accomplish these two objectives in patients with very small nodules that are separated from the pleural surface and therefore impossible to see by thoracoscopy. This article reviews the technique for hook-wire localization of pulmonary nodules and the keys to ensuring the best results.


Assuntos
Neoplasias Pulmonares , Nódulos Pulmonares Múltiplos , Nódulo Pulmonar Solitário , Criança , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Nódulo Pulmonar Solitário/diagnóstico por imagem , Toracoscopia , Tomografia Computadorizada por Raios X
2.
Radiologia (Engl Ed) ; 63(5): 400-405, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34625195

RESUMO

INTRODUCTION: Self-limiting sternal tumors of childhood (SELSTOC) are rapidly growing sternal lesions that tend to resolve spontaneously. Patients have no history of infection, trauma, or neoplasms, and the most likely etiologyis an aseptic inflammatory reaction of unknown origin. The differential diagnosis includes a wide spectrum of lesions such as tumors, infections, malformations, or anatomic variants. MATERIAL AND METHODS: We analyzed all cases of sternal masses in pediatric patients seen between 2012 and 2019; five of these had findings compatible with SELSTOC. We retrospectively recorded patients' race, sex, age, clinical presentation, laboratory findings, imaging tests, treatment, and follow-up. RESULTS: We present five cases of rapidly growing sternal lesions whose clinical and radiological features are compatible with SELSTOC. In the absence of alarming symptoms and laboratory markers, watchful waiting could be an appropriate therapeutic approach. However, patients with some findings such as fever, elevated acute phase reactants, and/or comorbidities could require therapeutic interventions such as antibiotics or percutaneous drainage. In our series, depending on the clinical presentation and the patient's comorbidities, different therapeutic approaches were adopted (a conservative approach in two patients, antibiotics in three patients, and percutaneous drainage in one patient). In all cases, the sternal lesion was absent at discharge and/or at later follow-up visits. CONCLUSION: Radiologists and pediatricians must be aware of this entity and the different diagnostic and therapeutic approaches to rapidly growing sternal lesions in pediatricpatients because recognizing SELSTOC can avoid unnecessary diagnostic tests and/or disproportionate therapeutic strategies.


Assuntos
Neoplasias Ósseas , Neoplasias Torácicas , Neoplasias Ósseas/diagnóstico , Criança , Drenagem , Humanos , Estudos Retrospectivos , Esterno/diagnóstico por imagem
3.
Radiologia (Engl Ed) ; 63(3): 245-251, 2021.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-33483144

RESUMO

In pediatric patients with sarcomas, hepatoblastomas, or other types of primary tumors, lung metastases are often found at diagnosis or during follow-up. The wide variety of primary tumors and clinical situations makes management and follow-up of these patients challenging. Chest CT is the best way to detect the dissemination of disease to the lungs. Many pulmonary nodules are nonspecific, and many might not be pathological. Others have characteristics that make them suspicious. Although there are some general features that indicate that a pulmonary nodule is likely to be a metastasis, sometimes the meaning of these features depends on the primary tumor. Furthermore, metastases can develop during the course of the disease, and the protocols for follow-up are different for different primary tumors. We review the different protocols used at our hospital for the primary tumors that most often metastasize to the lungs, including the criteria for lung metastases and the follow-up for each primary tumor.

4.
Int Endod J ; 50(9): 860-874, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27770435

RESUMO

The aim of this scoping study was to evaluate the survival rate and nature of tissue formed inside root canals of human immature permanent teeth with necrotic pulps (NIPT) under root canal revascularization (RCR). The search was performed in SciVerse Scopus®, PubMed/MEDLINE, Web of Science®, BIREME and in the grey literature up to November 2015. The keywords were selected using MeSH terms and DECs. Two independent reviewers scrutinized the records obtained considering specific inclusion criteria. The included studies were evaluated in accordance with a modified Arksey and O' Malley's framework. From 375 studies that were evaluated, 75 were included. A total of 367 NIPT were submitted to RCR, from which only 21 needed further endodontic treatment. The weighted mean follow-up time was 17.6 months. The data were derived mainly from case reports (69%) or small case series (15%). NaOCl [0.5-6%] was applied as the disinfecting solution in almost all studies. Triple antibiotic paste was as effective as Ca(OH)2 as on intracanal medicament. De novo tissue was cementum and poorly mineralized bone positive to bone sialoprotein (BSP) but negative to dentine sialoprotein (DSP). Failures were associated mainly with reinfection of the root canal. The majority of included studies reported a significant increase in both root length and width. However, as most of these data came from case reports, they must be interpreted with care, as most were focused on treatment successes (not failures). Therefore, well-designed randomized controlled trials comparing RCR with available apexification treatments are needed to address this gap in the literature.


Assuntos
Cavidade Pulpar/irrigação sanguínea , Necrose da Polpa Dentária/terapia , Tratamento do Canal Radicular , Cavidade Pulpar/patologia , Cavidade Pulpar/fisiopatologia , Necrose da Polpa Dentária/fisiopatologia , Dentição Permanente , Humanos , Estimativa de Kaplan-Meier , Plasma Rico em Plaquetas , Regeneração
5.
Int Endod J ; 49(6): 543-50, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26101143

RESUMO

Stem cell-based therapy (SC-BT) is emerging as an alternative for endodontic therapies. The interaction between stem cells and scaffolds plays a crucial role in the generation of a 'friendly cell' microenvironment. The aim of this systematic review was to explore techniques applied to regenerate the pulp-dentine complex tissue using SC-BT. An electronic search into the SciVerse Scopus (SS), ISI Web Science (IWS) and Entrez PubMed (EP) using specific keywords was performed. Specific inclusion and exclusion criteria were predetermined. The search yielded papers, out of which full-text papers were included in the final analyses. Data extraction pooled the results in four main topics: (a) influence of the chemical properties of the scaffolds over cell behaviour; (b) influence of the physical characteristics of scaffolds over cell behaviour; (c) strategies applied to improve the stem cell/scaffold interface; and (d) influence of cue microenvironment on stem cell differentiation towards odontoblast-like cells and pulp-like tissue formation. The relationship between the scaffolds, the environment and the growth factors released from dentine are critical for de novo pulp tissue regeneration. The preconditioning of dentine walls with ethylenediaminetetraacetic acid (EDTA) was imperative for successful pulp-dentine complex regeneration. An analyses of the grouped results revealed that pulp regeneration was an attainable goal.


Assuntos
Polpa Dentária/crescimento & desenvolvimento , Transplante de Células-Tronco/métodos , Engenharia Tecidual/métodos , Regeneração Tecidual Guiada/métodos , Humanos , Alicerces Teciduais
6.
Int Endod J ; 45(3): 266-72, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22176029

RESUMO

AIM: To evaluate the effect of four tooth storage temperature-based methods on quality of RNA obtained from cells retrieved from human dental pulps and human pre-dentine. METHODOLOGY: RNA was isolated from dental pulp tissue and from cells retrieved by scraping the pre-dentine of freshly extracted human third molars (n = 15) using TRIzol(®) reagent. Teeth were randomly assigned to the following temperature conditions: immediate RNA isolation after tooth extraction, liquid nitrogen (24 h), -80 °C (24 h), 20 °C (24 h) and 4 °C (6 h). RNA integrity was checked by the density of 28S and 18S ribosomal RNA. RT-PCR was used to analyse the expression of odontoblast makers (DSPP, DMP1 and MEPE) and the housekeeping gene GAPDH. RESULTS: All experimental conditions evaluated preserved RNA integrity. The three odontoblastic markers were amplified from the pulp tissue and from the cells associated with pre-dentine. CONCLUSION: The four storage options allowed RNA isolation for RT-PCR analysis. These findings may facilitate the use of clinically derived human dental pulp and odontoblasts for endodontic research.


Assuntos
Criopreservação/métodos , Odontoblastos/citologia , RNA/análise , Preservação de Tecido/métodos , Adolescente , Adulto , Polpa Dentária/citologia , Dentina/citologia , Eletroforese em Gel de Ágar , Proteínas da Matriz Extracelular/análise , Glicoproteínas/análise , Humanos , Fosfoproteínas/análise , RNA Ribossômico 18S/análise , RNA Ribossômico 28S/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sialoglicoproteínas/análise , Adulto Jovem
7.
Int Endod J ; 44(1): 59-64, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20880134

RESUMO

AIM: To compare and contrast two colorimetric assays used for the measurement of proliferation using two dental pulp cell types: dental pulp stem cells (DPSC) and human dental pulp fibroblasts (HDPF). METHODOLOGY: Dental pulp stem cells or HDPF were seeded at 0.25×10(4) cells per well in 96-well plates. Cell proliferation was evaluated after 24-72h. At the end of the experimental period, the sulforhodamine B (SRB) assay or a water-soluble tetrazolium salt (WST-1) assay was performed. Optical densities were determined in a microplate reader (Genius; TECAN). Data were analysed by Student's t-test (comparison between cell types) and one-way anova followed by Tukey test (time-point intervals). Pearson' correlation tests were performed to compare the two assays for each cell line. RESULTS: Both assays showed that DPSC had higher proliferation rates than HDPF. A positive significant correlation between the two colorimetric assays tested for both cell types DPSC (Pearson's correlation coefficient=0.847; P<0.05) and HDPF (Pearson's correlation coefficient=0.775; P<0.05). CONCLUSION: Both tests demonstrated similar trends of cell proliferation, and thus are both appropriate for the evaluation of DPSC and HDPF. The choice of assay is therefore one of the practical applications. SRB stained plates can be dried and stored so may have utility in laboratories where data may require review or when access to analytical equipment is limited. WST-1 assays have the benefit of both ease and speed and may have utility in laboratories requiring either high throughput or rapid analyses.


Assuntos
Células-Tronco Adultas/citologia , Colorimetria/métodos , Polpa Dentária/citologia , Fibroblastos/citologia , Análise de Variância , Proliferação de Células , Células Cultivadas , Ensaio de Unidades Formadoras de Colônias/métodos , Corantes/metabolismo , Humanos , Rodaminas/metabolismo , Estatísticas não Paramétricas , Sais de Tetrazólio/metabolismo
8.
J Dent ; 37(5): 331-5, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19203819

RESUMO

OBJECTIVES: To evaluate the effect of the filler content in the cohesive strength (sigma), Weibull modulus (m) and degree of conversion (DC) of an experimental adhesive system. METHODS: A HEMA/Bis-GMA/TEGDMA-based adhesive was formulated and filled with silica nanofillers in the following weight percentages (wt%): R0=0%; R1=1%; R3=3%; R5=5% and R10=10%. The adhesive of Adper Scotchbond Multi-Purpose (SBMP) system was used as a commercial reference. Twenty dumbbell-shaped specimens with cross-sectional area of 0.5mm(2) were made per group and tensile tested with a crosshead speed of 0.5mm/min until fracture. The cohesive strength was calculated in MPa. DC was obtained through FTIR after light curing for 25s. Data were submitted to one-way ANOVA and Tukey's test (alpha=0.05) and to Weibull analysis. RESULTS: Mean sigma results were: R0=65.4+/-8.4; R1=73.2+/-8.8; R3=72.0+/-8.4; R5=73.1+/-9.7; R10=85.5+/-13.1 and SBMP=79.0+/-11.0MPa. R10 presented the highest sigma, while R0 showed the lowest. R5 and SBMP did not differ significantly (p<0.05). Weibull analysis revealed no significant difference in structural reliability between groups. The experimental adhesives presented similar results of DC, which, in turn, were significantly higher than the SBMP. CONCLUSIONS: The addition of 10% filler in weight improves the cohesive strength of the adhesive, not interfering in the structural reliability or the degree of conversion.


Assuntos
Análise do Estresse Dentário , Cimentos de Resina , Adesividade , Bis-Fenol A-Glicidil Metacrilato , Dureza , Cura Luminosa de Adesivos Dentários , Teste de Materiais , Metacrilatos , Nanocompostos , Tamanho da Partícula , Transição de Fase , Polietilenoglicóis , Ácidos Polimetacrílicos , Cimentos de Resina/química , Dióxido de Silício , Espectroscopia de Infravermelho com Transformada de Fourier , Análise de Sobrevida
9.
J Agric Food Chem ; 56(18): 8728-36, 2008 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-18729458

RESUMO

The aim of the present study was to characterize, quantify, and compare the different selenium species that are produced when lactic fermentation with two different types of microorganisms, bacteria (Lactobacillus) and yeast (Saccharomyces), take place to produce yogurt and kefir, respectively, and to study the transformation process of these species as a function of time. These two dairy products were chosen for the study because they are highly consumed in different cultures. Moreover, the microorganisms present in the fermentation processes are different. While the bacteria Lactobacillus is the one responsible for yogurt fermentation, a partnership between bacteria and the yeast Saccharomyces causes kefir fermentation. A comparative study has been carried out by fermenting Se(IV) enriched milk in the presence of both types of microorganisms, where the concentration range studied was from 0.5 to 20 microg g (-1). Enzymatic extraction enabled selenium speciation profiles, obtained by anionic exchange and ion-pairing reversed phase high performance liquid chromatography (IP-RP-HPLC) with inductively coupled plasma mass spectrometry (ICP-MS) detection. Scanning electron microscopy (SEM) applied to the enriched samples showed segregated Se (0), at added concentrations higher than 5 microg g (-1). The main Se species formed depended on the type of microorganism involved in the fermentation process, SeCys 2 and MeSeCys being the main species generated in yogurt and SeMet in kefir. The results obtained are different for both kinds of samples. Lactic fermentation for yogurt produced an increment in selenocystine (SeCys 2) and Se-methylselenocysteine (MeSeCys), while fermentation to produce kefir also incremented the selenomethionine (SeMet) concentration. The Se species are stable for at least 10 and 15 days for kefir and yogurt, respectively. After this period, selenocystine concentration decreased, and the concentration of Se-methylselenocysteine was found to significantly increase.


Assuntos
Laticínios/microbiologia , Fermentação , Lactobacillus/metabolismo , Saccharomyces cerevisiae/metabolismo , Selênio/metabolismo , Cromatografia Líquida de Alta Pressão , Produtos Fermentados do Leite/microbiologia , Ácido Láctico/metabolismo , Microscopia Eletrônica de Varredura , Selênio/análise , Iogurte/microbiologia
10.
Electromyogr Clin Neurophysiol ; 47(7-8): 361-7, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18051630

RESUMO

INTRODUCTION: Neurophysiological monitoring during spinal surgery reduces the associated neurological complications. Continuous EMG recording has developed an useful technique for spinal root monitoring PATIENTS AND METHODS: Fifty four patients who underwent surgery for several lumbosacral spinal lesions (low and high degree spondylolisthesis, spinal stenosis, degenerated or herniated lumbar discs) were studied to evaluate the effectiveness of continuous EMG recording in monitoring spinal root function during surgery. Electrical root or screw stimulation was also performed in nine of them. To correlate surgical spinal root lesion with a precise EMG injury activity an animal study with 5 pigs was performed; lesion was produced by prolonged spinal root traction. RESULTS: In the porcine group EMG discharges lasting longer than one minute after cessation of root traction was noted in 74% of spinal root levels (neurotonic discharges or pseudo-rhythmic activity in 70% of the cases). Spinal root lesion was demonstrated through EMG three weeks after surgery. In the patient group pathological-significant EMG activity was not recorded in any case during monitoring. Mechanical or chemical root stimulation during surgery produced brief lasting EMG bursts of no pathological significance. Only a patient developed a mild acute L5-S1 radiculopathy after surgery (1 false negative) and post-operative deficit was not observed in the rest. Electrical stimulation of spinal roots and screws allowed to identify root level and prove the adequate placement of screws. CONCLUSION: Spontaneous and evoked EMG recordings are simple techniques that provide continuous information about lumbosacral spinal roots function throughout surgery.


Assuntos
Monitorização Fisiológica/métodos , Traumatismos da Medula Espinal/diagnóstico , Traumatismos da Medula Espinal/fisiopatologia , Raízes Nervosas Espinhais/fisiopatologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Criança , Estimulação Elétrica , Eletromiografia/métodos , Feminino , Humanos , Deslocamento do Disco Intervertebral/fisiopatologia , Deslocamento do Disco Intervertebral/cirurgia , Período Intraoperatório , Região Lombossacral , Masculino , Pessoa de Meia-Idade , Procedimentos Neurocirúrgicos/efeitos adversos , Estimulação Física , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/prevenção & controle , Estudos Retrospectivos , Traumatismos da Medula Espinal/prevenção & controle , Estenose Espinal/fisiopatologia , Estenose Espinal/cirurgia , Espondilolistese/fisiopatologia , Espondilolistese/cirurgia , Suínos
11.
Rev Neurol ; 44(4): 193-7, 2007.
Artigo em Espanhol | MEDLINE | ID: mdl-17311207

RESUMO

INTRODUCTION: Friedreich's ataxia (FA) is the most common type of early-onset hereditary ataxia, starting during childhood and adolescence. Both the central and peripheral nervous systems are compromised. AIM. To describe the alterations found in the neurophysiological examination and their relation with the degree of disability and the time the disease lasts. PATIENTS AND METHODS: We examined 26 patients diagnosed with FA by means of a genetic study with multimode evoked potentials, transcranial magnetic stimulation, peripheral nerve conductions and a study of small myelinated-unmyelinated sensory fibres using quantitative sensory tests (thermotest). RESULTS: Peripheral sensory potentials, somatosensory potentials and motor responses with transcranial stimulus were pathological in all patients. From the early stages of the disease there were both peripheral sensory neuropathy and alterations of the somatosensory potentials and motor responses with transcranial stimulus in the lower limbs. Alterations in the somatosensory potentials in the upper limbs and the motor responses obtained by transcranial stimulus were related with the degree of disability. Brainstem and visual potentials were altered in 16 and 28% of cases, respectively; only reduced amplitude of the P100 was related with the degree of disability. In the thermotest, 50% of the patients showed alterations. CONCLUSIONS: Increased disability in patients with FA is related with the progressive involvement of the somatosensory and pyramidal pathways. Although traditionally reports have claimed that the thick myelinated fibres are the ones involved in FA, we found alterations in the small calibre fibres in half the patients.


Assuntos
Sistema Nervoso Central/fisiologia , Ataxia de Friedreich/fisiopatologia , Condução Nervosa/fisiologia , Sistema Nervoso Periférico/fisiologia , Adolescente , Adulto , Criança , Potenciais Evocados , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fibras Nervosas/patologia , Fibras Nervosas/fisiologia , Exame Neurológico/métodos , Temperatura , Estimulação Magnética Transcraniana
13.
Rev Neurol ; 41(8): 449-54, 2005.
Artigo em Espanhol | MEDLINE | ID: mdl-16224730

RESUMO

INTRODUCTION: Clinical, electrophysiological, genetic and biochemical deficiencies variability were evaluated in 52 patients diagnosed of mitochondrial respiratory chain diseases (MRCD). PATIENTS AND METHODS: 26 men and 26 women, aged 19 to 79 years, were tested by clinical examination, electrophysiological techniques, muscle biopsy and genetic and biochemical studies. RESULTS: The patients were classified into seven phenotypes: myopathy, chronic progressive external ophthalmoplegia, progressive ophthalmoplegia plus ataxia, Kearns-Sayre syndrome, mitochondrial encephalomyopathy with lactic acidosis and stroke episodes (MELAS), myoclonic encephalopathy with ragged-red fibers (MERRF), and encephalopathies. Each phenotype may begin by different ways. The electromiography showed myopathy in 39 cases and various types of neuropathy in 10. Ragged-red COX negative fibers or widespread electron microscopic abnormalities were found in 47 cases. Simple deletions, multiple deletions and three different point mutations were observed. Deficiency of complexes I, II, III and IV were found alone or in different associations. CONCLUSIONS: MRCD shows wide variations in clinical, genetic and biochemical studies. Some patients with nonspecific manifestations, mainly of central nervous system, need careful attention and to be on account of diagnostic suspicion.


Assuntos
Transporte de Elétrons/fisiologia , Doenças Mitocondriais/fisiopatologia , Encefalomiopatias Mitocondriais/fisiopatologia , Adulto , Idoso , Ataxia/genética , Ataxia/fisiopatologia , Biópsia , Eletrofisiologia , Feminino , Humanos , Síndrome de Kearns-Sayre/genética , Síndrome de Kearns-Sayre/fisiopatologia , Síndrome MELAS/genética , Síndrome MELAS/fisiopatologia , Síndrome MERRF/genética , Síndrome MERRF/fisiopatologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Doenças Mitocondriais/genética , Encefalomiopatias Mitocondriais/genética , Mutação , Oftalmoplegia Externa Progressiva Crônica/genética , Oftalmoplegia Externa Progressiva Crônica/fisiopatologia , Fenótipo
14.
Rev. esp. pediatr. (Ed. impr.) ; 59(6): 504-508, nov. 2003. tab, graf
Artigo em Es | IBECS | ID: ibc-37703

RESUMO

La Neisseria meningitidis es una causa importante de morbilidad y mortalidad en nuestro medio. Con el objetivo de evaluar la existencia de factores de riesgo para la enfermedad meningocócica en las Áreas de Salud de Amadora y Sintra se realizó un estudio retrospectivo, casos-control, en niños menores de 15 años de edad, internados desde el 1 de enero de 1997 hasta el 31 de diciembre de 2001. Se investigaron: edad, sexo, mes de ingreso, lactancia materna, asistencia a guarderías/escuelas, número de personas convivientes en el domicilio, número de habitaciones en el domicilio, hábitos tabáquicos de los padres, frecuencia por parte de los padres de bares/discotecas y grandes superficies comerciales. De un total de 56 casos, se verificó un predominio de la enfermedad en los menores de 6 años (85,7 por ciento), en el Sexo masculino (57 por ciento) y en los meses de enero a abril (53,6 por ciento). En el análisis multivariado (regresión logística) la enfermedad meningocócica estaba asociada de forma independiente al tabaquismo de la madre (o.r. 6,2 IC: 2,12 -18,35) y a la frecuentación de los padres a los centros comerciales (o.r. 4,6 IC: 1,45 - 14,37), bares y discotecas (o.r. 4,4IC: 1,57 - 12,54). El estudio confirma por tanto factores de riesgo ya anteriormente conocidos y otros todavía no descritos (AU)


Assuntos
Feminino , Pré-Escolar , Lactente , Masculino , Humanos , Neisseria meningitidis/patogenicidade , Infecções Meningocócicas/epidemiologia , Fatores de Risco , Estudos Retrospectivos , Poluição por Fumaça de Tabaco/efeitos adversos , Inquéritos e Questionários , Estudos de Casos e Controles
15.
Anal Bioanal Chem ; 374(3): 466-76, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12373396

RESUMO

To obtain reliable information on speciation analysis it is necessary to previously evaluate the stability of the species in the sample of interest. Furthermore, in those cases in which sample treatment to extract the species is time-consuming, an evaluation of how to maintain species integrity in the extracts is paramount. Thus, the present paper reports the stability of total Se, SeMet and TMSe+ in freeze-dried oyster and in the enzymatic extracts stored in Pyrex and polyethylene containers at different temperatures (-18, 4 and 20 degrees C). Total selenium determinations and Se speciation were carried out by HG-AAS after acid digestion in a microwave oven and by on-line coupling of cation exchange HPLC-ICP-MS after enzymatic hydrolysis, respectively. The results obtained for the freeze-dried sample showed that total Se and the selenium species evaluated are stable for at least 12 months, under all the conditions tested. However, Se species in the enzymatic extracts are only stable for 10 days if stored at 4 degrees C in Pyrex containers. These results show that the extracts do not necessarily have to be analysed just after sample treatment.


Assuntos
Cromatografia Gasosa-Espectrometria de Massas/métodos , Ostreidae/química , Ostreidae/enzimologia , Compostos de Selênio/análise , Selênio/análise , Selenometionina/análise , Espectrofotometria Atômica/métodos , Animais , Liofilização/métodos , Subtilisina/metabolismo
16.
Rev Neurol ; 35(8): 738-40, 2002.
Artigo em Espanhol | MEDLINE | ID: mdl-12402226

RESUMO

INTRODUCTION: Periodic paralyses are illnesses related with the dysfunction of the ionic pathways of the muscle fibre membrane. Neurophysiological diagnosis by means of a conventional electromyogram (EMG) is rather unsatisfactory when exploring patients in the asymptomatic phase, since they often display unspecific changes. Furthermore, it does not identify the alterations in muscular excitability. The exercise test consists in determining the variation in the area or the amplitude of the muscular action potential, which is obtained through electrical stimuli that are repeated periodically for several minutes after having carried out local exercise with the explored muscles. It is a simple technique that enables us to achieve a significant reduction in the area or amplitude of the action potential (more than 40% or 50% with regard to the basal value) in certain diseases produced by ionic pathway dysfunction, while the patient is in the asymptomatic phase. CLINICAL CASES: We report the cases of three patients diagnosed as suffering from hypokalemic periodic paralysis. During the asymptomatic phase, the EMG revealed characteristic myopathic changes in only one case and unspecific alterations in the other two. Nevertheless, the exercise test that was also performed during the asymptomatic phase showed a characteristic pathological response in the three patients. CONCLUSION: The exercise test is a technique that indirectly shows up the progressive loss of muscle fibre membrane excitability and helps diagnosis in asymptomatic patients.


Assuntos
Teste de Esforço , Paralisia Periódica Hipopotassêmica/diagnóstico , Potenciais de Ação , Adulto , Canais de Cálcio/fisiologia , Estimulação Elétrica , Eletromiografia , Epinefrina , Feminino , Humanos , Transporte de Íons , Masculino , Potássio/sangue
17.
Cancer Genet Cytogenet ; 122(2): 124-30, 2000 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-11106823

RESUMO

The prognostic value of tumoral ploidy and its relation with nonrandom chromosome alterations were analyzed in 89 cases of acute lymphoblastic leukemia. Ploidy is associated with the number of nonrandom chromosome alterations and survival. The pseudodiploid and hypodiploid groups had a high incidence of nonrandom alterations and poor survival while the diploid and high hyperdiploid groups had a lower incidence of nonrandom alterations and longer survivals. The patients in the low hyperdiploid group with random alterations received the same treatment as the diploid and high hyperdiploid groups but had poor survivals. Our analysis confirms that ploidy is a very important prognostic factor and suggests that patients with low hyperdiploidy should receive intensive therapies similar to those of patients in the groups with a high number of nonrandom alterations.


Assuntos
Ploidias , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Adolescente , Adulto , Criança , Aberrações Cromossômicas , Análise Citogenética , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Prognóstico , Espanha , Análise de Sobrevida
18.
J Mass Spectrom ; 35(7): 878-84, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10934441

RESUMO

A procedure is described for the enzymatic digestion of tuna and mussel samples that allows the determination of selenium species by high-performance liquid chromatography in conjunction with inductively coupled plasma mass spectrometry. The species were extracted by two-step enzymatic hydrolysis with a non-specific protease (subtilisin). The selenium species were separated on a Spherisorb 5 ODS/AMINO column using two different chromatographic conditions, namely phosphate buffers at pH 2.8 and pH 6.0 as mobile phases. The method determines organic (trimethylselenonium, selenocystine, selenomethionine and selenoethionine) and inorganic selenium species (selenite and selenate), but only organic selenium species were found in the samples. The sum of identified selenium species in the sample was about 30% of the total selenium present in the enzymatic extract despite the fact that recoveries of total hydrolysed selenium were 93-102%. Trimethylselenonium ion and selenomethionine were found in both tuna and mussel samples and an unknown selenium species was also found in tuna samples.


Assuntos
Compostos Organosselênicos/análise , Pronase , Selênio/análise , Subtilisinas , Animais , Cromatografia Líquida de Alta Pressão/métodos , Hidrólise , Indicadores e Reagentes , Espectrometria de Massas/métodos
19.
Talanta ; 51(3): 537-45, 2000 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-18967885

RESUMO

A flow-through fluorescent sensor for the consecutive determination of Fe(III) and total iron is described. The reactive phase of the proposed sensor, which has a high affinity for complexed Fe(III), consists of pyoverdin immobilized on controlled pore glass (CPG) by covalent bonding. This pigment selectively reacts with Fe(III) decreasing its fluorescence emission. Total inorganic iron is determined as Fe(III) after on-line oxidation in a mini-column containing persulphate immobilized on an ion exchange resin. The developed method allows the determination of Fe(III) in the 3-200 (g l(-1) range. The relative standard deviations of 10 determinations of 60 (g l(-1) of Fe(III) and 20 (g l(-1) of Fe(III)+Fe(II) are 3 and 5%, respectively. The sensor has been satisfactorily applied to speciate iron in synthetic, tap and well waters and wines. There were no significant differences for total inorganic iron determination between this new method and the atomic absorption spectroscopy reference method at the 95% confidence level. The sensor allows the concentration of Fe(II) to be calculated as the difference between total inorganic iron and Fe(III). The lifetime of the sensor is at least 3 months in continuous use or the equivalent of 1000 determinations.

20.
Rev Neurol ; 28(6): 543-54, 1999.
Artigo em Espanhol | MEDLINE | ID: mdl-10714337

RESUMO

INTRODUCTION: Disfunction of thin myelinated and unmyelinated fibers may appear isolated or in association with large-myelinated fibers lesion. Small-fiber neuropathy includes autonomic and sensory symptoms, most prominent of them thermo-algesic deficits. DEVELOPMENT AND CONCLUSION: In some acute neuropathies, small-fiber lesion is relatively pure, as in pandysautonomia, but it also appears in disorders with prominent somatic involvement, such as the Guillain-Barre syndrome, in which case autonomic symptoms worsens the prognosis. Small-fiber dysfunction is important in certain diseases that involve different components of the nervous system, like paraneoplastic syndromes and porphyria. Some drugs and toxic substances may damage thin myelinated and unmyelinated fibers. Nowadays, chronic idiopathic small-fiber neuropathy is diagnosed more frequently, because of the recent development of techniques that selectively evaluate this peripheral nerve component. Hereditary sensory and autonomic neuropathies can also be studied. Small-fiber dysfunction is very prominent in some diseases, e.g. diabetes mellitus and amyloidosis. In the pure autonomic failure, only the peripheral component of the autonomic nervous system is affected, and this feature is the key to make diagnosis versus multisystem atrophy. There are situations in which there is no clear deviation from normality, namely old age autonomic failure and orthostatic intolerance syndrome in which autonomic evaluation is mandatory.


Assuntos
Fibras Nervosas Mielinizadas/patologia , Doenças do Sistema Nervoso Periférico/patologia , Doença Aguda , Síndrome de Adie/complicações , Amiloidose/complicações , Botulismo/complicações , Complicações do Diabetes , Síndrome de Guillain-Barré/complicações , Infecções por HIV/complicações , Humanos , Síndromes Paraneoplásicas do Sistema Nervoso/complicações , Doenças do Sistema Nervoso Periférico/complicações , Doenças do Sistema Nervoso Periférico/diagnóstico , Porfirias/complicações
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