Molecular biomarkers correspond to all endogenous or exogenous biomolecules, whose presence or alteration in metabolic pathways indicate the response of a biological system to a disturbance caused by internal or external factors. The search for biomarkers has allowed deepening the knowledge of complex pathophysiological mechanisms of diseases, interactions with potential drugs, and the improvement of diagnostic and therapeutic tests, establishing itself as a central point in personalized medicine. In addition, the development of the omics sciences has fostered an increasing exploration in this field of research. This review presents essential and relevant concepts in biomarker research, explores the various definitions and classifications of biomarkers according to their purpose, the critical aspects to be considered in experimental design, the primary employed study models (in vivo, in vitro, and in silico) and the factors that have hindered their ultimate implementation. Finally, important, and current clinical and pharmacological research areas in which biomarker research play a central role are presented.

Glycerol can be determined in several products by various analytical techniques. Titrimetric ones have stood out for their low cost, being recommended as standards. However, reliable, simple, fast, and green methods with low quantification limits are still needed. Titration of glycerol is based on its oxidation by periodate (Malaprade reaction) producing formic acid, formic aldehyde, and iodate. Iodate and periodate are iodometrically titrated, but mutual interference between these ions has produced methods with some drawbacks. Here is proposed to mask periodate with molybdate, to eliminate interference, determining the glycerol content through iodate, employing iodometric titration. Solutions containing from 10 to 1000 µg of glycerol were analyzed (error < 3.4%). The method was successfully applied for the determination of glycerol in biodiesels from different raw materials. Recoveries were from 92.9 ± 0.4 to 111 ± 3%. Semi-micro extraction was done, providing a fast procedure for determining free glycerol in biodiesel (< 10 min).

Wavelength dispersion X-ray fluorescence spectrometry (WDXRF) is a non-destructive technique and therefore attractive for gunshot residues (GSR) analysis. It is well known for determination of inorganic constituents of samples. However, X-ray scattering region spectral data is not commonly used, although it may provide information about organic constituents and their interactions. This work employed X-ray scattering region and inorganic elements spectral data for a better characterization of GSR. Swabs containing residues collected from the hand of people who fired (shooters group) and also from the hands of people which did not fire (control group) with guns were analyzed directly by the WDXRF. Brake pad and people who perform activities that favor the accumulation of characteristic elements of GSR on their hands were chosen to compose the control group. Principal components analysis (PCA) discriminated the GSR according to the firearm/cartridge used. However, similar GSR clustering did not occur without X-ray scatter data, showing the importance of X-ray scattering spectrum for GSR evaluation. The k-nearest neighbors (k-NN) method correctly classified all samples from shooters and control groups, employing from 1 to 5 nearest neighbors. No anomalous behavior was detected by PCA and hierarchical cluster analysis (HCA).

RESUMO Paciente do sexo masculino, 52 anos de idade, queixou-se de perda de sensibilidade e dor na maxila. Após investigação, foi solicitado o tratamento endodôntico do elemento dentário 12. Posteriormente, observou-se aumento de volume arroxeado e consistência amolecida na porção vestibular da gengiva inserida do elemento 12. O segmento dentário superior anterior apresentava mobilidade. A biópsia incisional evidenciou neoplasia maligna de origem epitelial glandular, sugestiva de carcinoma adenoide cístico (CAC) sólido. Um painel imuno-histoquímico foi realizado, o qual confirmou a suspeita histopatológica. O CAC sólido pode gerar dificuldades de diagnóstico, pois essa lesão exibe aspectos morfológicos similares aos de outras neoplasias malignas.

ABSTRACT A 52-year-old male patient complained of loss of sensitivity and pain in the maxilla. After examination, root canal treatment of tooth 12 was requested. Subsequently, there was a purplish increased volume of softened consistency in the area of vestibular attached gingiva of tooth 12. The anterior upper dental segment presented mobility. Incisional biopsy revealed malignant neoplasm of glandular epithelial origin, suggestive of solid adenoid cystic carcinoma (ACC). An immunohistochemical panel was performed, which confirmed the histopathological suspicion. Solid ACC may lead to diagnostic difficulties, since this lesion exhibits morphological features similar to other malignancies.

RESUMEN Paciente masculino, 52 años de edad, quejase de pérdida de sensibilidad y dolor en la maxila. Después de la consulta, se indicó el tratamiento endodóntico del elemento dental 12. Luego, se observó aumento de volumen amoratado y consistencia ablandada en la superficie vestibular de la encía insertada del elemento 12. El segmento dental superior anterior presentaba movilidad. La biopsia incisional demostró neoplasia maligna sugestiva de carcinoma adenoide quístico (CAQ) sólido. Se realizó un panel de pruebas inmunohistoquímico que confirmó la sospecha histopatológica. El CAQ sólido puede causar dificultades de diagnóstico, pues esa lesión muestra aspectos morfológicos semejantes a otras neoplasias malignas.

Biodiesel synthesis from soybean oil using methanol and alkaline catalysts occurs in the following two consecutive steps: dispersion of methanol in the oil and methanolysis. The effect of the alkaline catalysts NaOCH3, KOCH3, NaOH, and KOH in the dispersion step at 30-60 ºC and under mechanical stirring at 400 rpm was evaluated. The dispersion step accounts for 44.6-73.3% of the total synthesis time and was poorly favored compared to methanolysis due to the increase in temperature. The catalysts decreased the dispersion time, although most of them increased the methanol-oil interfacial tension. K-containing catalysts were more active than their Na analogues due to higher adsorption of K+ in the methanol-oil interface and the higher production of methyl esters (which act as emulsifying agents), which promote a more favorable interfacial tension. The alkaline cation effect was more significant in the dispersion step than in the methanolysis step.

RESUMO Os diferentes microhabitats proporcionados pelas pradarias marinhas e o habito das espécies determinam a distribuição vertical de espécies de crustáceos. Este estudo verificou a influência da sazonalidade sobre a distribuição espacial da comunidade de crustáceos associada a uma pradaria de Halodule wrightii. De abril de 2006 a julho de 2007, foram realizadas 15 amostragens na praia das Goiabeiras, estado do Ceará, em cada uma com cinco amostras seccionadas em partes aérea e subterrânea. Cumáceos e o anfípode Hyale media (Dana, 1853) tiveram a maior frequência, densidade e dominância em relação a outros táxons, em ambos os estratos. A comunidade exibiu mudanças graduais ao longo do estudo, em ambos os estratos aéreo e subterrâneo, mas a estrutura da pradaria não foi suficiente para explicar a distribuição vertical da fauna de crustáceos ao longo do tempo.

ABSTRACT The different microhabitats provided by seagrasses and the habit of the species determinate the vertical distribution of crustaceans. This study verified the influence of the seasonality on the spatial distribution of the crustacean community associated with a Halodule wrightii meadow. From April 2006 to July 2007, we performed fifteen samplings in Goiabeiras Beach, Ceará State, each with five sectioned replicates in belowground and aboveground. Cumaceans and the amphipod Hyale media (Dana, 1853) had a higher frequency, density, and dominance than the other taxa, in both strata. The community exhibited gradual changes along the study, in both the belowground and aboveground strata, but the seagrass structure was not sufficient to explain the vertical distribution of the crustacean fauna along the time.

O grande atrativo da Operação de Senning como descrita originalmente é a utilização das paredes do próprio átrio do paciente para a realização dos túneis venosos. A atrioseptostomia por balão, utilizada atualmente na grande maioria dos casos de transposição das grandes artérias (TGA), cria grandes comunicações interatriais. Com isso, é necessário a utilização de enxertos biológicos ou sintéticos (Dacron, Teflon e pericárdio bovino) na septação do átrio esquerdo. Doze crianças consecutivas, com idades de 5 meses a 4 anos (média = 20 meses), foram submetidas à Operação de Senning com a utilização de tecidos do próprio paciente. O diagnóstico era de TGA em 9, TGA com comunicação interventricular (CIV) em 1, TGA com estenose pulmonar valvar discreta em 1, TGA com justaposição das aurículas em 1 caso e todas as crianças foram submetidas à atrioseptostomia com balão no período neonatal. Em 5 casos foi utilizada a aurícula esquerda aberta e invertida para a septação interatrial, 1 com inversão e, em 5, inversão com abertura da aurícula esquerda e uso do próprio pericárdio in situ para a realização do túnel das veias pulmonares, devido às reduzidas dimensões do átrio direito (1 caso de justaposição das aurículas). O tempo de internação variou de 10 a 24 dias (média 15 dias), sendo que o período de pós-operatório variou de 7 a 22 dias (média 12 dias). Não houve óbitos no período de internação hospitalar. O seguimento no pós-operatório foi de 8 a 34 meses (média 23 meses) e todos os pacientes apresentaram boa evolução clínica. O ecocardiograma realizado no período de internação e no seguimento pós-operatório não evidenciou sinais de obstrução ao fluxo nos túneis intracardíacos. O uso de tecidos do próprio paciente in situ, com potencial possibilidade de crescimento, resgata a vantagem principal da técnica originalmente descrita por Senning.

One of the main theoretical advantages of the original Senning Operation is the ability to avoid either biologic or synthetic patches for atrial septum augmentation or to enlarge pulmonary venous pathways. To accomplish this we have performed the Senning procedure with some modifications that allow the operation to be completed without the use of heterologous tissue. Twelve children, aged 5 months to 4 years (mean age: 20 months) with transposition of great arteries who had previous balloon atrial septostomy were submitted to the Senning procedure. The following associated lesions were diagnosed: ventricular septal defect in 1 patient, valvular pulmonary stenosis in 1 and auricular juxtaposition in 1. The modified technique used for atrial septum augmentation was the use of open inverted left auricula in 5 cases, inverted auricula in 2 and in situ autologous pericardium for venous pathway enlargement in 5. The hospitalization was 10 to 24 days (mean = 15 days) and the post-operative period was 7 to 22 days (mean = 12 days). There were no in-hospital or late deaths during a mean follow-up period of 23 months (range 8 to 34 months). All patients had a good clinical outcome and their follow-up echocardiographic examinations showed no evidence of venous pathway obstruction. This modified Senning Operation can be performed without either biologic or synthetic patches for atrial septum augmentation or to enlarge pulmonary venous pathway. The use of autologous in situ tissues with potential for growth, retains the main theoretical advantage of the original technique.

Visando um melhor resultado estético pode-se optar por técnicas minimamente invasivas na correção cirúrgica das cardiopatias congênitas. Entre os acessos utilizados realizamos a esternotomia parcial em 20 pacientes pediátricos para correção de comunicação interatrial (CIA). Após análise deste grupo de pacientes concluímos tratar-se de técnica cirúrgica segura, de fácil execução e com ótimo resultado estético. Não ocorreram complicações específicas relacionadas ao acesso cirúrgico.

A better cosmetic effect may result from minimally invasive techniques available for the surgical correction of congenital cardiopathies. Amongst the possible accesses for the correction of an interatrial communication, we selected a partial sternotomy which we performed in 20 pediatric patients. When analyzed, this group of patients demonstrated that this approach is a safe and easy one, and that the cosmetic result is very satisfactory. No complications specifically related to the surgical access were observed.

OBJETIVOS: Avaliar a confiabilidade e vieses na aplicação do Questionário de Morbidade Psiquiátrica de Adultos (QMPA) a informantes secundários comparando-os com informantes primários. MÉTODO: Foram estimados os índices Kappa para as questões do QMPA em uma amostra de 69 casais selecionados aleatoriamente em uma área da Região Metropolitana de Salvador, Bahia, Brasil. Analisaram-se a magnitude e direção dos vieses com base na variação proporcional da prevalência. Cada entrevistado foi avaliado como informante primário, quando respondia sobre seus próprios sintomas, e como informante secundário, quando respondia sobre o cônjuge. RESULTADOS: O uso de informantes secundários leva a estimativas de morbidade enviesadas, cuja magnitude e direção dependem do gênero do informante. Embora ambos, esposo e esposa tendam a subinformar a presença de sintomas do seu cônjuge, as esposas produzem informações mais confiáveis. CONCLUSÕES: Frente às limitações no uso de informante primários, as esposas ou donas-de-casa podem ser recomendadas como informantes secundárias na aplicação do QMPA em estudos da comunidade.

OBJECTIVES: To evaluate the reliability, magnitude and direction of the resulting bias in the application of a screening instrument for mental disorders by considering proxy informants in comparison to primary informants. METHODS: Data are taken from a general morbidity community-based survey carried out in 520 randomly selected households of an industrial area of the Metropolitan Region of Salvador, the capital of Bahia state, Brazil. During the pilot phase, the first 70 families of the total sample were asked to participate in the evaluation of research instruments. The Questionnaire of Adult Psychiatric Morbidity, QAPM, consists of 44 questions about psychiatric symptoms widely used in Brazil. The husbands and wives of the selected families answered QAPM questions regarding themselves and their respective partners. One family refused to participate. The Kappa index was estimated for each QAPM question. To assess the magnitude and direction of bias, the proportional variation of prevalence was estimated from proxy and primary respondents. Each informant was analyzed as a primary informant when answering about his/her own symptoms and as a proxy informant when answering those about his/her partner. RESULTS: Proxy informants as compared to primary informants show weak reliability, as measured by the Kappa Index, particularly when husbands reported on their wives' symptoms. An overall underestimation of prevalence estimates was found, which reveals the potential negative bias with the use of proxy informants for psychological symptoms. No bias was found for only two questions (lack of appetite and globus hystericus) when women were taken as proxy informants for their husbands. In addition, departures of proxy informants from primary informant-based estimates were greater among men than to women. CONCLUSIONS: Proxy informants underestimate the occurrence of psychological symptoms in this community-based study. When the feasibility of a research project, based on the QAPM depends on the use of proxies, wives may be recommended as better informants than their husbands.

OBJETIVOS: Avaliar a confiabilidade e vieses na aplicação do Questionário de Morbidade Psiquiátrica de Adultos (QMPA) a informantes secundários comparando-os com informantes primários. MÉTODO: Foram estimados os índices Kappa para as questões do QMPA em uma amostra de 69 casais selecionados aleatoriamente em uma área da Região Metropolitana de Salvador, Bahia, Brasil. Analisaram-se a magnitude e direção dos vieses com base na variação proporcional da prevalência. Cada entrevistado foi avaliado como informante primário, quando respondia sobre seus próprios sintomas, e como informante secundário, quando respondia sobre o cônjuge. RESULTADOS: O uso de informantes secundários leva a estimativas de morbidade enviesadas, cuja magnitude e direção dependem do gênero do informante. Embora ambos, esposo e esposa tendam a subinformar a presença de sintomas do seu cônjuge, as esposas produzem informações mais confiáveis. CONCLUSÕES: Frente às limitações no uso de informante primários, as esposas ou donas-de-casa podem ser recomendadas como informantes secundárias na aplicação do QMPA em estudos da comunidade.

OBJECTIVES: To evaluate the reliability, magnitude and direction of the resulting bias in the application of a screening instrument for mental disorders by considering proxy informants in comparison to primary informants. METHODS: Data are taken from a general morbidity community-based survey carried out in 520 randomly selected households of an industrial area of the Metropolitan Region of Salvador, the capital of Bahia state, Brazil. During the pilot phase, the first 70 families of the total sample were asked to participate in the evaluation of research instruments. The Questionnaire of Adult Psychiatric Morbidity, QAPM, consists of 44 questions about psychiatric symptoms widely used in Brazil. The husbands and wives of the selected families answered QAPM questions regarding themselves and their respective partners. One family refused to participate. The Kappa index was estimated for each QAPM question. To assess the magnitude and direction of bias, the proportional variation of prevalence was estimated from proxy and primary respondents. Each informant was analyzed as a primary informant when answering about his/her own symptoms and as a proxy informant when answering those about his/her partner. RESULTS: Proxy informants as compared to primary informants show weak reliability, as measured by the Kappa Index, particularly when husbands reported on their wives' symptoms. An overall underestimation of prevalence estimates was found, which reveals the potential negative bias with the use of proxy informants for psychological symptoms. No bias was found for only two questions (lack of appetite and globus hystericus) when women were taken as proxy informants for their husbands. In addition, departures of proxy informants from primary informant-based estimates were greater among men than to women. CONCLUSIONS: Proxy informants underestimate the occurrence of psychological symptoms in this community-based study. When the feasibility of a research project, based on the QAPM depends on the use of proxies, wives may be recommended as better informants than their husbands.