Drug dual-release matrix proprieties and the correlations with nanostructure aggregation kinetics for siloxane-polyether/hydrogel nanocomposites

The influence of hydrogels on the nanostructural formation of siloxane-polyether nanocomposites was examined. The nanostructure was studied with small-angle X-ray scattering (SAXS) to determine the siloxane nanostructure aggregation mechanisms. The interactions between matrix and drug were examined by infrared spectroscopy to verify the compatibility of the drug with the matrix. For in vitro release tests Piroxicam was used as a model molecule. The variation of the different types of hydrogels, bis-acrylamide (BIS), poly(acrylamide-co-acrylic acid) (PAM) and polyvinylpyrrolidone (PVP) can modify the drug release profiles. The release behaviour was determined to be composed of two concomitant release mechanisms. The first is in the early stages of drug release, governed by erosion, diffusion and swelling and the second, in advanced stages of release, typical of diffusion through pores. These dependencies were found to be correlated to the physical and chemical properties of the nanocomposites, including the interactions disturbing polycondensation formation. The release rate depends on intramolecular matrix–matrix and intermolecular drug–matrix interactions, as well as a crystalline state of the matrix.

Nanostructure and drug dual-release properties correlation for siloxane-polyether nanocomposite.     

Antinociceptive activity and toxicology of the lectin from Canavalia boliviana seeds in mice

The aim of the present study was to evaluate the potential antinociceptive and toxicity of Canavalia boliviana lectin (CboL) using different methods in mice. The role of carbohydrate-binding sites was also investigated. CboL given to mice daily for 14 days at doses of 5 mg/kg did not cause any observable toxicity. CboL (1, 5, and 10 mg/kg) administered to mice intravenously inhibited abdominal constrictions induced by acetic acid and the two phases of the formalin test. In the hot plate and tail immersion tests, the same treatment of CboL induced significant increase in the latency period. In the hot plate test, the effect of CboL (5 mg/kg) was reversed by naloxone (1 mg/kg), indicating the involvement of the opioid system. In the open-field and rota-rod tests, the CboL treatment did not alter animals' motor function. These results show that CboL presents antinociceptive effects of both central and peripheral origin, involving the participation of the opioid system via lectin domain.     

Neonatal overfeeding impairs differentiation potential of mice subcutaneous adipose mesenchymal stem cells

Nutritional changes in the development (intrauterine life and postnatal period) may trigger long-term pathophysiological complications such as obesity and cardiovascular disease. Metabolic programming leads to organs and tissues modifications, including adipose tissue, with increased lipogenesis, production of inflammatory cytokines, and decreased glucose uptake. However, stem cells participation in adipose tissue dysfunctions triggered by overfeeding during lactation has not been elucidated. Therefore, this study was the first to evaluate the effect of metabolic programming on adipose mesenchymal stem cells (ASC) from mice submitted to overfeeding during lactation, using the litter reduction model. Cells were evaluated for proliferation capacity, viability, immunophenotyping, and reactive oxygen species (ROS) production. The content of UCP-2 and PGC1-α was determined by Western Blot. ASC differentiation potential in adipogenic and osteogenic environments was also evaluated, as well the markers of adipogenic differentiation (PPAR-γ and FAB4) and osteogenic differentiation (osteocalcin) by RT-qPCR. Results indicated that neonatal overfeeding does not affect ASC proliferation, ROS production, and viability. However, differentiation potential and proteins related to metabolism were altered. ASC from overfed group presented increased adipogenic differentiation, decreased osteogenic differentiation, and also showed increased PGC1-α protein content and reduced UCP-2 expression. Thus, ASC may be involved with the increased adiposity observed in neonatal overfeeding, and its therapeutic potential may be affected.     

The effects of hyperbaric oxygen therapy upon ototoxic injuries produced by amikacin in guinea pigs

Hyperbaric oxygen therapy (HBOT) has enhanced the prevention and treatment of auditory ailments such as ototoxicity.ObjectiveTo study the effects of HBOT upon ototoxic injuries produced by amikacin.MethodThis experimental study included 12 albino guinea pigs, whose auditory function was assessed through distortion product otoacoustic emissions (DPOAEs) and brainstem auditory evoked potentials (BAEPs) before and after the administration of amikacin (600 mg/kg/day) and HBOT sessions (2 ATA, 60 minutes). Morphological features were analyzed through scanning electron microscopy. Subjects were divided into four groups, as follows: group 1 - saline solution + HBOT; group 2 - amikacin for 8 days; group 3 - amikacin + seven days of rest; and group 4 - amikacin + HBOT.ResultsGroup 1 subjects had preserved function and morphology throughout the experiment; group 2 subjects had statistically significant levels of hair cell injury and functional impairment; subjects on groups 3 and 4 had statistically significant functional and morphological impairment after the administration of amikacin, which were still present after the proposed procedures had been carried out.ConclusionHyperbaric oxygen therapy did not change the cochlear hair cell morphology or the electro-physiological thresholds of the guinea pigs given amikacin.     

Socioeconomic and nutritional profile of patients with inflammatory bowel disease at a university hospital

BACKGROUND: Inflammatory bowel diseases include chronic and relapsing inflammatory disorders, represented by ulcerative proctocolitis and Crohns disease, commonly associated with malnutrition. AIM: Characterize the nutritional and socioeconomic profile of patients hospitalized at the Pernambuco "Hospital das Clínicas", Recife, PE, Brazil. METHODS:Cross-sectional study carried out at the gastroenterology clinic, which was previously approved by the Ethics Commission for studies involving human beings. The methods included clinical history data, socioeconomic conditions and nutritional assessment. Data were subject to statistical analysis (Students t test for equal and unequal variables). RESULTS: The sample consisted of 24 male and female patients, with a mean age of 43.83 +/- 16.13 years, mostly married, coming from Recife, with low income, who lived in their own house with relatives. We found a higher prevalence of ulcerative proctocolitis (62.5%), with diagnosis time of more than 5 years, symptoms of abdominal pain, bloody-mucous diarrhea with 6-9 evacuations/day, with the distal colon being the most affected part. Osteoporosis was present in 26.7% of cases. Nutritional status was assessed through the body mass index. The weight loss percentage corresponded to 41.7% and 70.8%, respectively, classified as malnourished, associated or not with high prevalence levels of anemia, hypoalbuminemia and hypocalcemia. Gender correlation evidenced higher triceps fold and arm circumference values in men. CONCLUSIONS: Despite the study limitations, data suggest relevant information about the occurrence of these diseases in the northeast of Brazil, as well as about its frequent association with important nutritional deficiencies.     

Vasodilator effects of Diocleinae lectins from the Canavalia genus

This study investigated and compared vascular actions of leguminous lectins obtained from the Canavalia genus (Canavalia brasiliensis, Canavalia gladiata, and Canavalia maritima) in the rat models of paw edema and isolated aorta. Paw edema was induced by subcutaneous injection of lectins (0.01–1 mg/kg) in animals pre-treated or not with indomethacin or L-NAME. In isolated aorta, cumulative concentration curves of C. gladiata or C. brasiliensis (1–100 µg/ml) were performed at the contraction plateau induced by phenylephrine or at tissue basal tonus. The mechanism of the lectin relaxant action was investigated by previous addition of L-NAME, indomethacin, or tetraethylammonium. In both models, the lectin domain involvement was evaluated by incubation of lectins with their ligand and non-ligand sugars. The lectins induced paw edema paralleled by protein leakage. The edematogenic activity elicited by C. gladiata and C. brasiliensis involves prostaglandins and nitric oxide (NO), while that of C. maritima occurs without NO interference. C. gladiata and C. brasiliensis elicited aorta relaxation involving NO and prostacyclin, while that of C. gladiata included EDHF. All lectin effects were prevented by their binding sugars. The present study demonstrated important vasodilator effects of different degrees and mechanisms in vivo and in vitro of Canavalia lectins. In vivo, the edematogenic activity was paralleled by plasma exudation, and in vitro, aorta relaxation was strictly dependent on intact endothelium. All effects occurred via interaction with lectin domains and participation of NO and/or prostanoids.