Ecological, beneficial, and pathogenic functions of the Type 9 Secretion System.

The recently discovered Type 9 Secretion System (T9SS) is present in bacteria of the Fibrobacteres-Bacteroidetes-Chlorobi superphylum, which are key constituents of diverse microbiomes. T9SS is instrumental in the extracellular secretion of over 270,000 proteins, including peptidases, sugar hydrolases, metal ion-binding proteins, and metalloenzymes. These proteins are essential for the interaction of bacteria with their environment. This mini-review explores the extensive array of proteins secreted by the T9SS. It highlights the diverse functions of these proteins, emphasizing their roles in pathogenesis, bacterial interactions, host colonization, and the overall health of the ecosystems inhabited by T9SS-containing bacteria.

The prevalence of motility within the human oral microbiota.

The human oral and nasal microbiota contains approximately 770 cultivable bacterial species. More than 2000 genome sequences of these bacteria can be found in the expanded Human Oral Microbiome Database (eHOMD). We developed HOMDscrape, a freely available Python software tool to programmatically retrieve and process amino acid sequences and sequence identifiers from BLAST results acquired from the eHOMD website. Using the data obtained through HOMDscrape, the phylogeny of proteins involved in bacterial flagellar motility, Type 4 pilus driven twitching motility, and Type 9 Secretion system (T9SS) driven gliding motility was constructed. A comprehensive phylogenetic analysis was conducted for all components of the rotary T9SS, a machinery responsible for secreting various enzymes, virulence factors, and enabling bacterial gliding motility. Results revealed that the T9SS outer membrane ß-barrel protein SprA of human oral microbes underwent horizontal evolution. Overall, we catalog motile microbes that inhabit the human oral microbiota and document their evolutionary connections. These results will serve as a guide for further studies exploring the impact of motility on shaping of the human oral microbiota.

Assessment of total evaporation rates and its surface distribution by tridimensional modelling and remote sensing.

In arid and semiarid environments, evaporation is responsible for significant water losses from reservoirs. This condition is of special concern in the Brazilian Northeast region, as this is one of the most populous semiarid areas in the planet. The present study aims to assess the spatio-temporal variability of evaporation rates on the water surface of Pentecoste reservoir, located in the Brazilian semiarid region, by using both the hydrodynamic model Delft3D and a remote sensing technique (RS). While RS has already been used to evaluate the spatial distribution of evaporation rates in lakes, Delft3D was innovatively tested and applied for this purpose for the first time in this study. The calibration results showed an accurate reproduction of the water level variability (r2 of 0.997), along with a satisfactory calibration of the reservoir's thermal structure for the full water column (MAE of 0.539 °C, RMSE of 0.572 °C, and NMAE of 0.008). Curves relating monthly evaporation rates with air temperature and wind speed showed strong correlation between those variables (r2 of 0.817 for air temperature and 0.849 for wind speed). Also, the averaged evaporation rates modeled by Delft3D differed by less than 5% compared to RS. Regarding the spatial distribution results, for the wet period the evaporation patterns were similar to those of RS, while in the dry period RS provided a more stable evaporation pattern when compared to Delft3D. The innovative approach proposed in the present study can be used to better understand the evaporation dynamics in surface waters and optimize the location of damping evaporation structures, namely air diffusers, shading systems, and floating solar panels, which are important for improving water availability, not only in drylands.

Optimization to Assist Design and Analysis of Temperature Control Strategies for Injection Molding-A Review.

Injection molding (IM) is the most widespread and economical way to obtain high-quality plastic components. The process depends, however, to a great extent, on the quality and efficiency of the injection molding tools. Given the nature of the IM process, the temperature control system (TCS), its design, and its efficiency are of utmost importance for achieving the highest possible quality of plastic parts in the shortest possible time. For that reason, the implementation of additive manufacturing (AM) in novel IM temperature control strategies has gained considerable interest in academia and industry over the years. Conformal cooling channels (CCCs) are TCSs that have already demonstrated great potential when compared to conventional gun-drilling systems. Nevertheless, despite the recent advances, the design of these systems is still an open field of study and requires additional research in both aspects deemed as critical: thermo-mechanical models and the application of optimization techniques. This review paper tackles all the relevant, available papers on this topic, highlighting thermo-mechanical models developed by TCS designers and the optimization techniques used. The articles were thoroughly analyzed, and key points on the design of new TCS and new opportunities were identified.

Roux-en-Y Gastric Bypass Vs Sleeve Gastrectomy in Super Obesity: a Systematic Review and Meta-Analysis.

Laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic sleeve gastrectomy (LSG) are safe procedures that may present sub-optimal results in superobesity (SO). A meta-analysis was performed aiming to summarize the available evidence on weight loss (primary outcome) and comorbidities resolution of LRYGB and LSG in patients with SO (BMI ≥ 50 kg/m2). From the 16 included studies, 7 integrated the meta-analysis. LRYGB showed a significantly higher weight loss at 6 to 12-months, but not after 24 months and a higher dyslipidemia resolution at 12 months. When compared with LSG, LRYGB achieved better weight loss after 6 and 12 months and higher dyslipidemia resolution after 1 year. There were no significant differences for resolution of the other co-morbidities studied.

Indicators for local health plan monitoring and evaluation: A modified Delphi consensus.

OBJECTIVE: There is still a lack of health indicators for monitoring and evaluating health planning at the local level. In Portugal, local health plans (LHP) include a prioritized set of health priorities, which should be monitored and evaluated. This study is an example of a low-resource method to identify and reuse indicators for LHP monitoring and evaluation already collected for other purposes. DESIGN AND SAMPLE: A modified Delphi consensus method was applied, with three rounds of email rating questionnaires and a final meeting, between January 2018 and January 2019. The Delphi panel consisted of eight members from the Planning and Administration Group of the Espinho/Gaia Local Public Health Unit. MEASUREMENTS: Panelists were asked to assess the indicators' validity for monitoring diseases/determinants from a pre-selected list of potential binomials between 140 PHC indicators and 15 diseases/determinants. RESULTS: After four rounds, there was consensus in considering 141 binomials (34.0%) as appropriate, diabetes mellitus being the disease with more appropriate indicators. CONCLUSION: This study portrays the applicability of a commonly used, easy and low-resource method in a Portuguese Local Public Health Unit to select and reuse primary health care indicators for LHP monitoring and evaluation.

Seasonal variation in the essential oil from Varronia curassavica jacq. accessions / Variación estacional en el aceite esencial de accesiones de Varronia curassavica Jacq

Varronia curassavica has anti-inflammatory properties because of the terpenes, α-humulene and ß-caryophyllene, present in the essential oil. The objective of this study was to evaluate the influence of seasonality on the essential oil of V. curassavica accessions. Leaves from six accessions were collected from the Germplasm Bank of the Federal University of Minas Gerais over 12 months. Correlations between the essential oil content and meteorological factors were determined. Gas chromatography analysis coupled with mass spectrometry was conducted to determine the chemical composition of the essential oil. The content and chemical composition of the oil varied throughout the year. Relative humidity was correlated with accessions ICA-VC2 (-0.64) and ICA-VC4 (0.68). ß-bourbonene, ß-elemene, spathulenol, germacrene, caryophyllene oxide, α-humulene, and ß-caryophyllene occurred in all accessions. Accession ICA-VC3 exhibited lower variation (22.17%), higher average (0.97%) essential oil, and maintained an average abundance of α-humulene greater than 2.6%, which is the amount necessary for phytotherapeutics.

Varronia curassavica tiene propiedades antiinflamatorias debido a los terpenos, α-humuleno y ß-cariofileno, presentes en el aceite esencial. El objetivo de este estudio fue evaluar la influencia de la estacionalidad en el aceite esencial de las accesiones de V. curassavica. Se recolectaron hojas de seis accesiones del Banco de Germoplasma de la Universidad Federal de Minas Gerais durante 12 meses. Se determinaron las correlaciones entre el contenido de aceite esencial y los factores meteorológicos. Se realizó un análisis de cromatografía de gases junto con espectrometría de masas para determinar la composición química del aceite esencial. El contenido y la composición química del aceite varió a lo largo del año. La humedad relativa se correlacionó con las accesiones ICA-VC2 (-0,64) e ICA-VC4 (0,68). En todas las accesiones aparecieron ß-bourboneno, ß-elemeno, espatulenol, germacreno, óxido de cariofileno, α-humuleno y ß-cariofileno. La accesión ICA-VC3 mostró una menor variación (22,17%), un promedio más alto (0,97%) de aceite esencial y mantuvo una abundancia media de α-humuleno superior al 2,6%, que es la cantidad necesaria para los fitoterápicos.

A Rare Case of Pulmonary-Renal Syndrome With Triple-Seropositive for Myeloperoxidase-Anti-Neutrophil Cytoplasm Antibody (MPO-ANCA), Proteinase 3 (PR3)-ANCA and Anti-Glomerular Basement Membrane (GBM) Antibodies.

Anti-glomerular basement membrane (anti-GBM) disease and anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitis are the main causes of pulmonary-renal syndrome (PRS). The concurrence of both ANCA - myeloperoxidase (MPO) and proteinase 3 (PR3) - and anti-GBM antibodies has been described, although positivity for all three antibodies has rarely been reported. The natural history of triple-positive patients as well as the best therapeutic approach remains unknown. We describe a case of an 80-year-old woman that presented to the emergency department with a 3-month history of progressive fatigue, malaise and anorexia, and 5 weeks of cough with blood-streaked sputum and progressive peripheral edema. Through the complementary study, a rare diagnosis of PRS with triple-seropositive for both ANCA (MPO and PR3) and anti-GBM antibodies was made in a patient with untreated chronic hepatitis B virus infection. She was treated with glucocorticoid, cyclophosphamide, plasma exchange and entecavir, with pulmonary recovery. Renal function did not improve. After 2 years, the patient is still in dialysis, but did not have relapse of alveolar hemorrhage and ANCA and anti-GBM antibody titers remain negative. The authors intend to warn to PRS, in particular this rare cause, since delaying diagnosis can lead to significant morbidity and mortality for patients.

A New Phenotype of Ataxia With Oculomotor Apraxia Type 4.

Ataxia with oculomotor apraxia is a rare neurodegenerative subgroup of diseases with manifestations that include cerebellar ataxia, oculomotor apraxia, extrapyramidal features, and sensorimotor neuropathy. In 2015, ataxia with oculomotor apraxia type 4 was described in 11 Portuguese individuals. The mean age of onset was 4.3 years, with severe extrapyramidal manifestations, neuropathy, rapid progression, and ataxia, being wheelchair-bound during adolescence. The disease is caused by homozygous or compound heterozygous mutations in the PNKP gene. In this case report, we describe two sisters, who were 52- and 58-years-old, with cerebellar dysarthria, oculomotor apraxia, dystonia, and gait ataxia. Two new mutations in the PNKP gene were detected in both sisters, confirming the diagnosis of ataxia with oculomotor apraxia. They were remarkable because they were able to walk unaided during adulthood and had epilepsy. With these clinical cases, we attempt to raise awareness of the possibility of different phenotypes of this rare disease, expanding the spectrum of manifestations of ataxia with oculomotor apraxia type 4.

[Portuguese Consensus on the Diagnosis and Management of Lewy Body Dementia (PORTUCALE)]. / Consenso Português para o Diagnóstico e Gestão Clínica da Demência com Corpos de Lewy (PORTUCALE).

Lewy body dementia is a common cause of dementia leading to the progressive deterioration of cognitive function and motor skills, behavioral changes, and loss of autonomy, impairing the quality of life of patients and their families. Even though it is the second leading cause of neurodegenerative dementia, diagnosis is still challenging, due to its heterogenous clinical presentation, especially in the early stages of the disease. Accordingly, Lewy body dementia is often misdiagnosed and clinically mismanaged. The lack of diagnostic accuracy has important implications for patients, given their increased susceptibility to the adverse effects of certain drugs, such as antipsychotics, which may worsen some symptoms associated with Lewy body dementia. Therefore, a specialist consensus based on the analysis of the most updated and relevant literature, and on clinical experience, is useful to all professionals involved in the care of these patients. This work aims to inform and provide recommendations about the best diagnostic and therapeutic approaches in Lewy body dementia in Portugal. Moreover, we suggest some strategies in order to raise the awareness of physicians, policy makers, and the society at large regarding this disease.

A demência com corpos de Lewy é uma causa comum de demência, provocando a perda progressiva de funções cognitivas e capacidades motoras, alterações comportamentais, e perda de autonomia, com compromisso da qualidade de vida dos doentes e seus familiares. Apesar de ser a segunda causa mais frequente de demência neurodegenerativa, o diagnóstico mantém-se um desafio, devido à sua apresentação clínica heterogénea, sobretudo nas fases iniciais da doença. Por conseguinte, a demência com corpos de Lewy é frequentemente mal diagnosticada e clinicamente gerida de forma insuficiente. A falta de acuidade diagnóstica tem implicações significativas para os doentes, dada a maior suscetibilidade aos efeitos adversos de determinados fármacos, tais como os antipsicóticos, que podem agravar alguns sintomas associados à demência com corpos de Lewy. Por conseguinte, um consenso de especialistas, baseado na análise da literatura mais atual e relevante, e na experiência clínica, é útil para todos os profissionais envolvidos no cuidado destes doentes. O objetivo deste trabalho é informar e gerar recomendações acerca das melhores abordagens diagnóstica e terapêutica da demência com corpos de Lewy em Portugal. Além disso, sugerimos estratégias para aumentar a sensibilização dos médicos, dos decisores políticos e da sociedade em geral em relação a esta doença.

Are pediatricians and otolaryngologists well prepared to identify early signs of vertical facial growth?

BACKGROUND: The prevalence of vertical facial growth is very high in the developed world. Most authors agree that mouth breathing is its main cause. Even though care is mainly conducted by odontologists, the professionals who first see these patients are pediatricians and otolaryngologists. The objective of this study is to analyze the ability of pediatricians and otolaryngologists to identify early signs of vertical facial growth among children. METHODS: 60 participant aged 4.1-13.7 years were analyzed subjectively by 9 otolaryngologists, 9 pediatricians and two specialists in dentofacial orthopedics. They were also assessed objectively with cephalometric analysis. RESULTS: Otolaryngologists showed 34.78% sensitivity, 92.86% specificity and 48.33% efficiency. Pediatricians showed 13.04% sensitivity, 100% specificity and 33.33% efficiency. Using a linear regression model compared against the objective measurements we found a weak positive correlation both for otolaryngologists and pediatricians. CONCLUSION: The sensitivity was very low for both groups. We believe it is of paramount importance to increase the awareness and the ability of otolaryngologists and pediatricians to recognize signs of disrupt facial growth.

Role of the "other Babinski sign" in hyperkinetic facial disorders.

BACKGROUND: The "other Babinski sign" consists in the co-contraction of the orbicularis and frontalis muscles, causing an eyebrow elevation during ipsilateral eye closure. It cannot be voluntarily reproduced. AIMS OF THE STUDY: To determine the utility of this sign in the differential diagnosis of hyperkinetic facial disorders. METHODS: The presence of the sign was assessed in consecutive patients with blepharospasm, primary hemifacial spasm or post-paralytic facial syndrome treated in a botulinum toxin outpatient clinic. RESULTS: Of the 99 patients identified, 86 were included, 41 with blepharospasm (32 female, mean age 71±11years), 28 with hemifacial spasm (16 female, mean age 65±12years) and 17 with post-paralytic facial syndrome (14 female, mean age 50±17years). The sign was detected in 67.9% of the patients with hemifacial spasm, in 23.5% of the post-paralytic facial syndrome group and in none of the patients with blepharospasm, exhibiting a sensitivity of 51% and a specificity of 100% for the diagnosis of hemifacial spasm/post-paralytic facial syndrome and a specificity of 76% for hemifacial spasm, compared to post-paralytic facial syndrome. CONCLUSIONS: This sign is highly specific for the diagnosis of peripherally induced hyperkinetic facial disorders. Its assessment should integrate the routine examination of patients with abnormal facial movements.

Association of retrospective time estimation and severity of cognitive impairment.

INTRODUCTION: Time perception has an important role in everyday life, but is not commonly measured in clinical routine assessment of suspected cognitive impairment, given the complexity of available assessment methods. Furthermore, evidence on the pattern of retrospective time perception in neurodegenerative diseases is contradictory. METHOD: We asked 321 patients referred to neuropsychological assessment to retrospectively estimate the duration of the neuropsychological assessment session. We calculated the session actual duration, ratio, and accuracy of response. Patients were grouped into three categories: subjective cognitive impairment, mild cognitive impairment, and mild to moderate dementia. RESULTS: We found an overall tendency for underestimation of time, but no significant differences between groups regarding time estimation. There were significant, but weak, associations between time estimation and severity of cognitive impairment in several domains, with slightly different patterns across groups. CONCLUSIONS: Regardless of etiology, the majority of patients underestimated time, which was weakly associated with the severity of cognitive impairment. Global retrospective estimation may be clinically informative, particularly in a minority of extreme cases.

Hypertrophic olivary degeneration and cerebrovascular disease: movement in a triangle.

Hypertrophic olivary degeneration is a rare kind of trans-synaptic degeneration that occurs after lesions of the dentatorubro-olivary pathway. The lesions, commonly unilateral, may result from hemorrhage due to vascular malformation, trauma, surgical intervention or hypertension, tumor, or ischemia. Bilateral cases are extremely rare. This condition is classically associated with development of palatal tremor, but clinical manifestations can include other involuntary movements. We describe 2 cases: unilateral hypertrophic olivary degeneration in a 60-year-old man with contralateral athetosis and neurologic worsening developing several years after a pontine hemorrhage and bilateral hypertrophic olivary degeneration in a 77-year-old woman with development of palatal tremor, probably secondary to pontine ischemic lesions (small vessel disease).

Atrial ectopic activity in cryptogenic ischemic stroke and TIA: a risk factor for recurrence.

BACKGROUND: To characterize atrial ectopic activity in patients with cryptogenic ischemic stroke (CIS) or transient ischemic attack (TIA) and determine its prognostic significance. METHODS: Retrospective cohort study, in which 184 patients with CIS or TIA who had performed 24-hour Holter electrocardiogram were included. The median follow-up was 27.5 months. Baseline clinical and imagiologic characteristics, etiologic investigation results, and ischemic stroke and TIA recurrences information were collected. Number of atrial premature complexes (APCs) per hour was categorized as less than 10 APCs/hour, 10-30 APCs/hour, and more than 30 APCs/hour. RESULTS: Most of the patients had less than 10 APCs/hour (82.6%), 8.2% had 10-30 APCs/hour, and 9.2% had more than 30 APCs/hour. Patients with more than 30 APCs/hour had a greater median left atrium diameter than patients with 30 APCs/hour or less (42 mm vs. 38 mm; 95% confidence interval [CI], .50-7.00; P = .003). Annual recurrence rate of CIS or TIA was 2.9% in patients with less than 10 APCs/hour, 11.0% in 10-30 APCs/hour, and 22.6% in more than 30 APCs/hour (P = .001). More than 30 APCs/hour were independently associated with recurrence risk in multivariate survival analysis (hazard ratio, 3.40; 95% CI, 1.12-10.32; P = .030). CONCLUSIONS: In patients with CIS or TIA, frequent atrial ectopic activity (>30 APCs/h) was independently associated with increased risk of stroke or TIA recurrence. Further studies need to validate frequent atrial ectopic activity as a risk factor for recurrence in cryptogenic stroke and confirm its role as a predictor of occult atrial fibrillation.

Multiple sclerosis and motherhood choice: an observational study in Portuguese women patients.

INTRODUCTION. Multiple sclerosis (MS) is a disabling disease occurring mainly in women of childbearing age. MS may interfere with family planning and motherhood decision. AIM. To study the influence of MS diagnosis and course of the disease on motherhood decision. PATIENTS AND METHODS. The cohort of 35 to 45-year-old female patients diagnosed with MS for at least ten years was selected from six Portuguese MS centers. A structured questionnaire was applied to all patients in consecutive consultation days. Clinical records were reviewed to characterize and collect information about the disease and pregnancies. RESULTS. One hundred women were included; mean age at MS diagnosis was 26.3 ± 5.0 years; 90% of the participants presented with a relapsing-remitting MS; 57% had no pregnancies after the diagnosis. MS type and number of relapses were not significantly different between women with or without pregnancies after the diagnosis (p = 0.39 and p = 0.50, respectively). Seventy-seven percent of the patients did not have the intended number of pregnancies. Main reasons given were fear of future disability and the possibility of having relapses. Forty-three women considered that pregnancy might worsen MS. CONCLUSION. In our population, motherhood choice was unrelated to the MS type and the number of relapses. However, a relevant number of women had fewer pregnancies than those intended before MS diagnosis and believed that pregnancy could worsen the disease. An effort to better inform the patients should be made to minimize the impact of MS diagnosis on motherhood decision.

TITLE: Esclerosis multiple y decision de la maternidad: estudio observacional en pacientes portuguesas.Introduccion. La esclerosis multiple (EM) es una enfermedad incapacitante que afecta mayoritariamente a mujeres en edad fertil. La EM puede alterar el deseo de crear una familia y concebir hijos. Objetivo. Estudiar la influencia del diagnostico de la EM y de su evolucion sobre la decision de ser madre. Pacientes y metodos. Se selecciono una cohorte integrada por pacientes de 35-45 años diagnosticadas de EM desde hacia por lo menos 10 años que eran atendidas en seis centros portugueses. Las participantes respondieron a un cuestionario estructurado en dias de consulta consecutivos. Se revisaron las historias clinicas para caracterizar y recabar informacion sobre la enfermedad y los embarazos. Resultados. Participaron 100 mujeres; la media de edad en el momento del diagnostico de la EM era de 26,3 ± 5,0 años; el 90% de las participantes presentaba la forma remitente recurrente; el 57% de las pacientes no se habian quedado embarazadas despues del diagnostico. El tipo de EM y el numero de recidivas no difirieron de manera significativa entre las mujeres que habian concebido despues del diagnostico y las que no (p = 0,39 y p = 0,50, respectivamente). El 77% no habia tenido el numero de hijos deseado. Los principales motivos aducidos fueron el temor a la incapacidad futura y la posibilidad de sufrir recidivas. Cuarenta y tres mujeres creian que el embarazo podia agravar la EM. Conclusion. En la poblacion del estudio, la decision de ser o no ser madre no guardo relacion con el tipo de EM ni con el numero de recidivas. No obstante, un numero relevante de mujeres tuvieron menos embarazos de los que habian deseado antes de ser diagnosticadas y pensaban que la gestacion podia empeorar la enfermedad. Seria conveniente mejorar la informacion que reciben estas pacientes a fin de minimizar el impacto del diagnostico de la EM en la decision de ser madre.

Long-term mortality analysis in Parkinson's disease treated with deep brain stimulation.

Background. Few data have been published regarding long-term mortality in patients with Parkinson's disease treated with DBS. Methods. This study analyzed long-term mortality rates, causes, and correlates in PD patients treated with DBS. Results. 184 consecutive patients were included; mean follow-up was 50 months. Fifteen deaths occurred (total 8.15%, annual mortality rate 1.94%). Mean age at disease onset and at surgery was 48 ± 2.4 and 63 ± 1.6 years, respectively. Mean disease duration until death was 21 ± 7.8 years. Most deaths related to stroke, myocardial infarction, other vascular/heart disorders, or severe infection; one suicide was recorded. Deceased PD patients were mostly male and had lower motor benefit after DBS, but univariate analysis failed to show significant differences regarding gender and motor benefit. Survival was 99% and 94% at 3 and 5 years. Conclusions. Long-term survival is to be expected in PD patients treated with DBS, possibly higher than previously expected. Death usually supervenes due to vascular events or infection.

Evaluation of optimal conditions for determination of low selenium content in shellfish samples collected at Todos os Santos Bay, Bahia, Brazil using HG-AFS.

This work proposes a procedure for the determination of total selenium content in shellfish after digestion of samples in block using cold finger system and detection using atomic fluorescent spectrometry coupled hydride generation (HG AFS). The optimal conditions for HG such as effect and volume of prereduction KBr 10 % (m/v) (1.0 and 2.0 ml) and concentration of hydrochloric acid (3.0 and 6.0 mol L(-1)) were evaluated. The best results were obtained using 3 mL of HCl (6 mol L(-1)) and 1 mL of KBr 10 % (m/v), followed by 30 min of prereduction for the volume of 1 mL of the digested sample. The precision and accuracy were assessed by the analysis of the Certified Reference Material NIST 1566b. Under the optimized conditions, the detection and quantification limits were 6.06 and 21.21 µg kg(-1), respectively. The developed method was applied to samples of shellfish (oysters, clams, and mussels) collected at Todos os Santos Bay, Bahia, Brazil. Selenium concentrations ranged from 0.23 ± 0.02 to 3.70 ± 0.27 mg kg(-1) for Mytella guyanensis and Anomalocardia brasiliana, respectively. The developed method proved to be accurate, precise, cheap, fast, and could be used for monitoring Se in shellfish samples.