Em decorrência do hiperinsulinismo endógeno (HHE), a hipoglicemia é diagnosticada em um indivíduo sintomático com níveis baixos de glicose plasmática, concomitante a valores elevados de insulina plasmática e peptídeo-C. Entre as causas de HHE, estão as doenças das células-b das ilhotas pancreáticas, o uso de secretagogos e a hipoglicemia autoimune. Neste artigo de revisão, estudamos 24 pacientes com hipoglicemia decorrente de hiperinsulinismo endógeno com a finalidade de descrever os aspectos de diagnóstico e tratamento. Nosso estudo mostrou que, após a realização do teste de jejum de 12h (minijejum) em três dias diferentes, todos os pacientes preencheram os critérios diagnósticos de HHE. Adicionalmente, encontramos que 11 dos 12 pacientes (91,7%) que realizaram o teste do glucagon apresentaram níveis de glicose no tempo 120 minutos menores que 50 mg/dL e inferiores ao valor basal. O teste do minijejum (3 amostras) e o teste do glucagon poderiam ser úteis para evitar a realização do jejum prolongado no diagnóstico do hiperinsulinismo endógeno.

Hypoglycemia due to endogenous hyperinsulinism (EH) is diagnosed in a symptomatic patient with low levels of plasma glucose concomitant with elevated plasma insulin and C-peptide. Causes of EH are pancreatic islet-cells disease, use of insulin secretagogues, and autoimmune hypoglycemia. In this review, the authors studied 24 patients with hypoglycemia due to endogenous hyperinsulinism in order to describe aspects of diagnosis and treatment. Our study demonstrated that after 12 hours of fasting (mini-fasting test; at least three samples), all patients presented the diagnostic criteria for EH. Additionally, we found that 11 of 12 patients (91.7%) who underwent glucagon test achieved glucose levels less than 50 mg/dL and below baseline after 120 minutes. Mini-fasting (3 samples) and glucagon test may be useful to prevent prolonged fasting test to clarify the diagnosis of endogenous hyperinsulinism.

Amostras de material particulado total e MP10 foram coletadas entre agosto de 2006 e fevereiro de 2007 na estação rodoviária Prefeito José Carlos Lacerda. Foram analisados os 16 HPAs considerados prioritários, emitidos pelos veículos pesados em condições típicas de operação, usando CG/EM. α ΣHPA correspondeu a 0,0018% da massa de MPT e 0,0012% da massa de MP10. O conteúdo total de HPAs foi de 3,57 ng m-3 e 2,59 ng m-3 para o MPT e o MP10, respectivamente. A contribuição dos compostos carcinogênicos, conforme a USEPA, (B[a]An, B[b]F, B[k]F, B[a]Py, IPy e DB[ah]A) foi 1,86 ng m-3 (52% do total de HPAs) e 1,40 ng m-3 (54% do total de HPAs), para as amostras de MPT e MP10, respectivamente. As relações características e a análise estatística multivariada deram, em geral, resultados similares aos obtidos para poeira de solos, exceto para a relação Flt/(Flt+Py), 0,34, compatível com emissões de diesel. Os fluxos de deposição seca estão no intervalo 0,022-0,603 e 0,016-0,436 μg m-2 dia-1 para os compostos contidos no MPT e MP10, respectivamente.

Total particulate matter and PM10 samples were collected from August 2006 to February 2007 in Mayor José Carlos Lacerda bus station. 16 priority PAHs compounds emitted by heavy-duty vehicles on typical conditions of operation were analyzed by using GC/MS. ΣPAH accounted for 0.0018% of the TSP mass and 0.0012% of the PM10 mass. Total PAH contents on the particle phase were 3.57 ng m-3 and 2.59 ng m-3 for TSP and PM10, respectively. Contributions of carcinogenic USEPA priority PAHs (B[a]An, B[b]F, B[k]F, B[a]Py, IPy and DB[ah]A) were 1.86 ng m-3 (52% of total PAHs) and 1.40 ng m-3 (54% of total PAHs), for TSP and PM10 samples, respectively. Diagnostic ratios and multivariate statistical analysis were, in general, similar to those reported for soil dust except for the Flt/Flt+Py) ratio, 0.34, compatible with diesel emissions. Dry deposition fluxes were in the range of 0.022-0.603 and 0.016-0.436 μg m-2 day-1 for compounds in TSP and PM10, respectively.

Amostras de partículas totais em suspensão (PTS) e MP10 foram coletadas no Campus da FIOCRUZ, Rio de Janeiro (Brasil), entre abril de 2006 e março 2007, uma região suburbana com atividades industriais e comerciais intensas. Foram determinadas as concentrações de 16 compostos policíclicos aromáticos (HPAs) usando cromatografia gasosa acoplada com espectrometria de massas. As concentrações individuais se encontraram entre o limite de detecção (acenaftileno, acenafteno, antraceno e fluoreno) e 6,16 ng m-3 para o benzo[b]fluoranteno. Os cinco HPAs mais importantes, no PTS, foram B[b]F, Ipy, Py, Chry e DB[ah]An e a soma das concentrações médias dos 16 HPAs foi 15,53 ng m-3. Os mesmos compostos mais abundantes foram encontrados em MP10, onde foi determinada uma massa total de 8,99 ng m-3. Foram calculadas as relações características e as emissões veiculares foram identificadas como as fontes potenciais de HPAs no material particulado. A contribuição dos veículos leves e pesados é significativa, mas a análise de conglomerados e a análise fatorial não permitiram a classificação em emissões do diesel e da gasolina.

From April 206 to March 2007, total suspended particles (TSP) and PM10 samples were collected at the Campus of FIOCRUZ, situated in a suburban region with intense industrial and commercial activities in Rio de Janeiro (Brazil). The concentrations of 16 selected polycyclic aromatic hydrocarbons (PAHs) were determined by gas chromatography with mass selective detection. Individual concentrations were between the detection limit (acenaphtylene, acenaphthene, anthracene and fluorene) and 6.16 ng m-3 for benzo[b]fluoranthene. The five most abundant PAHs, in TSP, samples were B[b]F, Ipy, Py, Chry and DB[ah]An, and the mean sum of 16 PAHs was 15.53 ng m-3. The same most abundant compounds were obtained in PM10 samples and a total mean mass of 8.99 ng m-3 was determined. Diagnostic ratios were calculated and vehicular emissions were determined as the potential sources for PAHs in particulate matter. The contribution of both light duty and diesel engines is significant, but the cluster and factorial analysis failed to classify clearly in gasoline or diesel emissions.

Cadmium UPD on Au was studied by voltammetric and microgravimetric measurements. In the oxide formation/reduction potential region, a mass increasing/decreasing of 32 ng cm-2 was associated to incorporation/elimination of one oxygen per active site. The modifications promoted in the voltammetric and mass profiles by 10-5 M Cd(ClO4)2 are restricted to potentials more negative than 0.4 V. After a 120 s potential delay at 0.05 V, the positive sweep reveals an anodic peak with charge of 40 muC cm-2 and mass decrease of 22 ng cm-2, associated to Cd ads dissolution. Sulphate or chloride was added to the solution without significant influence, due to the low coverage with Cd or anions.

This work reviews recent studies of underpotential deposition (UPD) of several metals on Pt and Au substrates performed in the Grupo de Materiais Eletroquímicos e Métodos Eletroanalíticos (IQSC -- USP, São Carlos). The UPD Cu, Cd and Pb on Pt were analysed in terms of their influence in the oxygen evolution reaction. Partial blockage of surface active sites, promoted by Pb ad-atoms, resulted in a change from water to hydrogen peroxide as the final product. The Ag UPD on Pt and Au substrates was also discussed in this work. A detailed model of charge calculation for Ag monolayer was developed and confirmed by the rotating ring-disk data. The partial charge transfer in UPD studies was analysed in the Cd/Pt and Cd/Au systems and a value of 0.5 was found for the adsorption electrovalence of Cd ad-ions. The Sn/Pt UPD systems were studied from the point of view of the valences of metallic ions in solution. The deposition from Sn(IV) generates a full monolayer with a maximum occupation of approximately 40% of the surface active sites (340 µC cm-2) plus 105 µC cm-2 of Hads (half monolayer). Changing the metallic ion for Sn(II), it was possible to deposit a full monolayer (210 µC cm-2) without any detectable Hads. Finally, the effect of anions was discussed in the Zn/Pt and Zn/Au systems. Here, the hydrogen evolution reaction (her) and the hydrogen adsorption/desorption were used in order to investigate the maximum coverage of the surface with Zn ad-atoms. The full monolayer, characterised by the complete absence of Hads, was achieved only in 0.5 M HF solutions.