The assignment of absolute configuration (AC) is a crucial step in the structural characterization of natural products, especially for those subjected to biological assays. Methods such as X-ray crystallography, stereocontrolled organic synthesis, nuclear magnetic resonance (NMR), and chiroptical spectroscopies are commonly used to determine the AC of chiral natural compounds. Even with these well-established techniques, however, unambiguous stereochemical assignments of natural products remain a challenge, resulting in an increasing number of structural misassignments being reported every year. Herein, we will present the main techniques that have been used in AC reassignments of natural products over the last 10 years, along with some selected examples. Special attention will be paid to the strengths and weaknesses of each approach. With this, we expect to provide the readers with critical information to help them to choose the appropriate methods for correct AC determinations.

ABSTRACT Trypanosoma cruzi and Helicobacter pylori (HP) are pathogens that cause chronic diseases and have been associated with hypergastrinemia. The aim of this study was to evaluate the fasting gastrin levels in patients with different clinical forms of Chagas disease (CD), coinfected or not by HP. The enrolled individuals were outpatients attending at the university hospital. HP infection was assessed by serology and 13 C-urea breath test. Fasting serum gastrin concentration was measured by chemiluminescence assay. Gastric endoscopic and histological features were also evaluated. Associations between CD and serum gastrin level were evaluated in a logistical model, adjusting for age, gender and HP status. A total of 113 patients were evaluated (45 with Chagas disease and 68 controls). In the multivariate analysis, increasing serum gastrin levels (OR= 1.02; 95% CI= 1.01-1.12), increasing age (OR= 1.05; 95% CI= 1.02 - 1.09) and HP-positive status (OR = 2.88; 95% CI = 1.10 - 7.51) remained independently associated with CD. The serum gastrin levels were significantly higher in the group of patients with the cardiodigestive form ( P = 0.03) as well as with digestive form ( P = <0.001) of Chagas disease than in the controls. In conclusion, patients with cardiodigestive and digestive clinical forms of CD have increased basal serum gastrin levels in comparison with controls. Moreover, we also demonstrated that H. pylori coinfection contributes to the hypergastrinemia shown in CD.

Ceramic foams were produced from a sludge generated in the aluminum anodizing process by using an industrial polyurethane foam (replication method) with open cell sizes of 10 ± 5 ppi (porosity = 97%) which were impregnated with suspensions containing 50-61 wt.% alumina, 1 wt.% citric acid, 6 wt.% bentonite and fired at 1600 ºC for 2 h. The aluminum anodizing sludge shows a high alumina content (87.5 wt.%) and a low particle size (~1.7 mm) after calcination and milling. The obtained filters show porosity of approximately 70%, filtration capability (mass water flow) of 1.7 kg/s and mechanical strength under compression of 2.40 MPa.

OBJETIVO: Revisar as indicações e o manejo clínico das drogas psicoativas e antiepilépticas na infância e adolescência. FONTES DE DADOS: Estudo baseado em revisão de literatura. Os autores organizam, de acordo com os quadros patológicos, uma rotina para o manejo dos psicofármacos e das drogas antiepilépticas na infância e na adolescência. SÍNTESE DOS DADOS: Indicação clínica, dosagem terapêutica e efeitos colaterais dos psicofármacos e drogas antiepilépticas são descritos. O uso de psicofármacos na infância e adolescência está se tornando mais freqüente, com a disponibilidade de novos medicamentos e com o crescimento do conhecimento sobre diagnóstico de transtornos emocionais nessa faixa etária. CONCLUSÕES: O manejo dos psicofármacos e drogas antiepilépticas na faixa etária pediátrica requer amplo conhecimento da farmacocinética dos mesmos, assim como de seus efeitos colaterais deletérios. A escolha do fármaco adequado é determinante no sucesso terapêutico.

OBJECTIVE: To review the guidelines for the use of psychoactive and antiepileptic drugs in childhood and adolescence. SOURCES OF DATA: Literature review. SUMMARY OF THE FINDINGS: The clinical indications, dosage and side effects of psychoactive and antiepileptic drugs are presented. The use of psychoactive drugs is increasing due to the release of new drugs and to the better understanding of emotional disorders in children and adolescents. CONCLUSIONS: The use of antiepileptic and psychoactive drugs in childhood requires extensive knowledge concerning pharmacokinetics and deleterious side effects. An adequate choice of drugs is essential to ensure a successful treatment.