Sulfamethoxazole exposure to simulated solar radiation under continuous flow mode: Degradation and antibacterial activity.

Among pharmaceuticals, the occurrence of antibiotics in the environment is a subject of special concern due to their environmental impact, namely the development of bacterial resistance. Sulfamethoxazole (SMX) is one of the most commonly used antibiotics and it is regularly found, not only in effluents from sewage treatment plants (STPs), but also in the aquatic environment. Photodegradation appears as an alternative process for the removal of this type of pollutants from contaminated waters. In order to be used for a remediation purpose, its evaluation under continuous flow mode is essential, as well as the determination of the final effluent antibacterial activity, which were assessed in this work. As compared with batch operation, the irradiation time needed for SMX elimination under continuous flow mode sharply decreased, which is very advantageous for the target application. Moreover, the interrelation between SMX removal, mineralization and antibacterial activity was evaluated before and during photodegradation in ultrapure water. Although mineralization was slower than SMX removal, bacterial activity increased after SMX photodegradation. Such increase was also verified in environmental water matrices. Thus, this study has proven that photodegradation is an efficient and sustainable process for both (i) the remediation of waters contaminated with antibiotics, and (ii) the minimization of the bacterial resistance.

Photodegradation of sulfamethoxazole in environmental samples: The role of pH, organic matter and salinity.

Sulfamethoxazole (SMX) is the most representative antibiotic of the sulfonamides group used in both human and veterinary medicine, and thus frequently detected in water resources. This has caused special concern due to the pronounced toxicity and potential to foster bacterial resistance of this drug. Therefore, and to further understand the fate of SMX in the aquatic environment, its photodegradation under simulated solar radiation was here studied in ultrapure water and in different environmental samples, namely estuarine water, freshwater and wastewater. SMX underwent very fast photodegradation in ultrapure water, presenting a half-life time (t1/2) of 0.86 h. However, in environmental samples, the SMX photodegradation rate was much slower, with 5.4 h < t1/2 < 7.8 h. The main novelty of this work was to prove that pH, salinity and dissolved organic matter are determinant factors in the decrease of the SMX photodegradation rate observed in environmental samples and, thus, they will influence the SMX fate and persistence, potentially increasing the risks associated to the presence of this pollutant in the environment.

Photodegradation behaviour of estriol: An insight on natural aquatic organic matter influence.

Estriol (E3) is one of the steroidal estrogens ubiquitously found in the aquatic environment, photodegradation being an important pathway for the elimination of such endocrine disrupting compounds. However, it is important to understand how environmentally important components present in aquatic matrices, such as organic matter, may affect their photodegradation. The main objective of this work was to investigate the photodegradation of E3 in water, under simulated solar radiation, as well as the effect of humic substances (HS - humic acids (HA), fulvic acids (FA) and XAD-4 fraction) in E3 photodegradation. Moreover, the photodegradation behaviour of E3 when present in different environmental aquatic matrices (fresh, estuarine and waste water samples) was also assessed. Results showed a completely different E3 degradation rate depending on the aquatic matrix. In ultrapure water the half-life obtained was about 50 h, while in presence of HS it varied between 5 and 10 h. Then, half-life times between 1.6 and 9.5 h were determined in environmental samples, in which it was observed that the matrix composition contributed up to 97% for the overall E3 photodegradation. Therefore, E3 photodegradation in the considered aquatic matrices was mostly caused by photosensitizing reactions (indirect photodegradation).

Risk Factors for Mortality and Outcomes in Pediatric Acute Lung Injury/Acute Respiratory Distress Syndrome.

OBJECTIVES: Children admitted to PICUs often present with or develop respiratory failure that requires mechanical ventilation. We prospectively identified children admitted to three general PICUs, with the goal of identifying risk factors for mortality. DESIGN: Prospective multicenter observational study. SETTING: Three general PICUs, two in São Paulo and one in Curitiba, Brazil. PATIENTS: Children aged between 1 month and 15 years, consecutively admitted between August 2008 and July 2010, with acute lung injury or acute respiratory distress syndrome that developed at least 12 hours after invasive or noninvasive mechanical ventilation. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We used logistic regression models to explore the relationship between death and independent variables. Of 3,046 patients admitted to the three PICUs, 1,658 patients underwent mechanical ventilation, and 84 fulfilled the acute lung injury/acute respiratory distress syndrome inclusion criteria and were analyzed. Nearly 60% were boys, and the median age was 31 months. Pressure control/assist control was the initial mode of mechanical ventilation in 86% of cases, and the median durations of mechanical ventilation and PICU stay were 12 and 15 days, respectively. None of the eight patients with acute lung injury died, whereas 33 of 76 of the remaining patients with acute respiratory distress syndrome died, for an overall mortality rate of 39.3% (95% CI, 28.8-50.6%). In different multivariate logistic regression model, the number of organ dysfunctions at admission, peak inspiratory pressure, airway pressure gradient on day 1, and the mean airway pressure gradient over the first 7 days of mechanical ventilation were significantly associated with mortality. CONCLUSION: Mortality is high in pediatric acute lung injury/acute respiratory distress syndrome. Mechanical ventilation-associated risk factors for death among such patients are potential targets for intervention.

Exame clínico pediátrico: aquisição de habilidades na disciplina Pediatria Preventiva Social, FAMEB - UFBa / Pediatric clinical examination: acquired habilities during the course of Social Preventive Pediatrics, FAMED-UFBA

O estudo analisa as principais dificuldades referidas e as habilidades adquiridas pelos estudantes de Medicina na prática ambulatorial da disciplina Pediatria Preventiva Social, da Faculdade de Medicina da Universidade Federal da Bahia, em seu primeiro contato com a clínica pediátrica. Através de um questionário, os estudantes foram inquiridos, em dois momentos distintos (início e término da disciplina) acerca dos aspectos com maior dificuldade de superação e progressos obtidos no contato com as crianças. Essa atividade prática se caracteriza pelo atendimento primário ambulatorial, na qual se exercita a consulta pediátrica, enfatizando anamnese detalhada e o exame físico completo, além das peculiaridades das diversas faixas etárias pediátricas. Com relação à anamnese, os estudantes demonstraram ter menor segurança na análise do crescimento e do desenvolvimento neuropsicomotor, enquanto que, no exame físico, relataram redução no grau de segurança no exame do abdômen (palpação de órgãos) e dos órgãos genitais. No geral, houve aquisição de habilidades tanto na realização da anamnese quanto do exame físico, sendo que, para algumas variáveis, essa evolução foi mais evidente.