Development and in vitro evaluation of coated pellets containing chitosan to potential colonic drug delivery

In this work pellets containing chitosan for colonic drug delivery were developed. The influence of the polysaccharide in the pellets was evaluated by swelling, drug dissolution and intestinal permeation studies. Drug-loaded pellets containing chitosan as swellable polymer were coated with an inner layer of Kollicoat® SR 30 D and an outer layer of the enteric polymer Kollicoat® MAE 30 DP in a fluidized-bed apparatus. Metronidazole released from pellets was assessed using Bio-Dis dissolution method. Swelling, drug release and intestinal permeation were dependent on the chitosan and the coating composition. The drug release data fitted well with the Weibull equation, indicating that the drug release was controlled by diffusion, polymer relaxation and erosion occurring simultaneously. The film coating was found to be the main factor controlling the drug release and the chitosan controlling the drug intestinal permeation. Coated pellets containing chitosan show great potential as a system for drug delivery to the colon. © 2012 Elsevier Ltd.

Comparison of Two Staining Methods for Pollen Viability Studies in Sugarcane

The present work aimed to compare two staining methods for pollen viability evaluation in sugarcane. Pollen from four sugarcane genotypes were collected at three different times (6.00, 8.00 and 9.00 a.m.) and tested for viability using two staining methods (iodine and lactophenol blue). Three anthers, of each genotype were crushed in a glass slide with a drop of the respective stain (iodine 0.1 N and lactophenol blue). The percentage of pollen viability was obtained with an optic microscope (250×) and compared with the pollen germination at culture media where one raquis of each genotype was gentle shaken in a petridish. Three replicates (petri dishes) was performed for each genotype which were maintained at the temperature of 25 °C and air humidity around 95 % for 30 min. The factors (staining methods, genotypes and times) and their interactions were evaluated by the analysis of variance, F test (P < 0.01) and the means compared by the t test (P < 0.05). The lactophenol blue staining was more sensible than the iodine staining method to detect the decrease of pollen viability which occurs naturally in sugarcane. The iodine staining method was more stable and easier than lactophenol to perform the inflorescence classification at any evaluated time (6.00, 8.00 and 9.00 a. m.). Both staining methods overestimated the viability obtained by the germination at culture media when performed at 6.00 a.m. © 2012 Society for Sugar Research & Promotion.

In situ evaluation of a low fluoride concentration gel with sodium trimetaphosphate in enamel remineralization

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Synthesis and evaluation of diethylethylamine-chitosan for gene delivery: Composition effects on the in vitro transfection efficiency

Chitosan has been indicated as a safe and promising polycation vector for gene delivery. However its low transfection efficiency has been a challenging obstacle for its application. To address this limitation, we synthesized chitosan derivatives which had increasing amounts of diethylethylamine groups (DEAE) attached to the chitosan main chain. The plasmid DNA VR1412 (pDNA), encoding the ß-galactosidase (ß-gal) reporter gene was used to prepare nanoparticles with the chitosan derivatives, and the transfection studies were performed with HeLa cells. By means of dynamic light scattering and zeta potential measurements, it was shown that diethylethylamine-chitosan derivatives (DEAEx-CH) were able to condense DNA into small particles having a surface charge depending on the polymer/DNA ratio (N/P ratio). Nanoparticles prepared with derivatives containing 15 and 25% of DEAE groups (DEAE15-CH and DEAE25-CH) exhibited transfection efficiencies ten times higher than that observed with deacetylated chitosan (CH). For derivatives with higher degrees of substitution (DS), transfection efficiency decreased. The most effective carriers showed low cytotoxicity and good transfection activities at low charge ratios (N/P). Vectors with low DS were easily degraded in the presence of lysozyme at physiological conditions in vitro and the nontoxicity displayed by these vectors opens up new opportunities in the design of DEAE-chitosan-based nanoparticles for gene delivery. © 2013 IOP Publishing Ltd.

In vitro biomechanical evaluation of sagittal split osteotomy fixation with a specifically designed miniplate

Recent studies have evaluated many methods of internal fixation for sagittal split ramus osteotomy (SSRO), aiming to increase stability of the bone segments while minimizing condylar displacement. The purpose of this study was to evaluate, through biomechanical testing, the stability of the fixation comparing a specially designed bone plate to other two commonly used methods. Thirty hemimandibles were separated into three equal groups. All specimens received SSRO. In Group I the osteotomies were fixed with three 15 mm bicortical positional screws in an inverted-L pattern with an insertion angle of 90°. In Group II, fixation was carried out with a four-hole straight plate and four 6 mm monocortical screws. In Group III, fixation was performed with an adjustable sagittal plate and eight 6 mm monocortical screws. Hemimandibles were submitted to vertical compressive loads, by a mechanical testing unit. Averages and standard deviations were submitted to analysis of variance using the Tukey test with a 5% level of significance. Bicortical screws presented the greatest values of loading resistance. The adjustable miniplate demonstrated 60% lower resistance compared to bicortical screws. Group II presented on average 40% less resistant to the axial loading. © 2012 International Association of Oral and Maxillofacial Surgeons.

Evaluation of a propolis water extract using a reliable RP-HPLC methodology and in vitro and in vivo efficacy and safety characterisation

Since the beginning of propolis research, several groups have studied its antibacterial, antifungal, and antiviral properties. However, most of these studies have only employed propolis ethanolic extract (PEE) leading to little knowledge about the biological activities of propolis water extract (PWE). Based on this, in a previous study, we demonstrated the anti-inflammatory and immunomodulatory activities of PWE. In order to better understand the equilibrium between effectiveness and toxicity, which is essential for a new medicine, the characteristics of PWE were analyzed. We developed and validated an RP-HPLC method to chemically characterize PWE and PEE and evaluated the in vitro antioxidant/antimicrobial activity for both extracts and the safety of PWE via determining genotoxic potential using in vitro and in vivo mammalian micronucleus assays. We have concluded that the proposed analytical methodology was reliable, and both extracts showed similar chemical composition. The extracts presented antioxidant and antimicrobial effects, while PWE demonstrated higher antioxidant activity and more efficacious for the most of the microorganisms tested than PEE. Finally, PWE was shown to be safe using micronucleus assays. © 2013 Bruno Alves Rocha et al.

Evaluation of metals in water and sediments of micro-basins in the city of Americana, São Paulo state, Brazil

Water pollution found in major rivers in Brazil has its origin from urban sewage discharges and industrial effluent, carried out by small streams and rivers crossing cities. Therefore, studies related to hydrographic micro-basins offer the opportunity to establish environmental management strategies for restoring water resources, based on diagnosis of the water quality. Despite this understanding, few studies in urban and rural areas have been performed in a systematic manner in Brazilian micro-basins. The main goal of this research was to diagnose the water resources in micro-basins in the region of the district of Americana, São Paulo state, Brazil, through the quantification of metals in water and sediment. The methodology was based on the investigation of metals (Ba, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn), in four micro-basins, determined by inductively coupled plasma optical emission spectrometry (ICP-OES). The most significant result showed high concentration levels of chromium (969 μg L-1), downstream of the discharge of sewage from the city of Nova Odessa. This concentration in the river was above the allowed limit of Brazilian regulation agency (50 μg L-1 for Cr). Also high levels of Cr were found in the sediment (98.9 μg g-1) collected at the same monitored site. These results are important indicators of environmental performance and anthropogenic activities to help the government establish environmental management strategies aimed at the reduction of water pollution. © 2013 WIT Press.

The success rate of immediate implant placement of mandibular molars: A clinical and radiographic retrospective evaluation between 2 and 8 years

Background: Dental implants, indicated for re-establishing both mastigatory and aesthetic functions, can be placed in the sockets immediately after tooth extraction. Most studies investigate the anterior and upper regions of the dental arch, whereas few examine longitudinal appraisal of immediate implant installation in the mandibular molar region. Objective: The aim of this retrospective study was to evaluate the success rate of immediate dental implants placement in mandibular molars within a follow-up period as long as 8 years. Materials and methods: Seventy-four mandibular molar implants after non-traumatic tooth extraction between 2002 and 2008 were examined in the study. All implants were evaluated radiographically immediately after prosthesis placement, 1 year after implantation, and by the end of the experimental period, in 2010. Clinical evaluation was done according to [Albrektsson et al. (1986) The International Journal of Oral & Maxillofacial Implants, 1, 11-25] success criteria for marginal bone loss. The mean bone losses, calculated as the difference between the final evaluation measures and those taken by the end of the first year of implant, were compared using Kruskal-Wallis test with a significance level of 5%. Results: All implants presented clinical and radiographic stable conditions, that is, 100% success rate. Significant bone loss was not found between final evaluation and that of the first functional year (P > 0.05). Conclusion: Immediate implant placement of mandibular molars proved to be a viable surgical treatment given the high success rate up to 8 years after implantation. © 2012 John Wiley & Sons A/S.

Design, synthesis and biological evaluation of new aryl thiosemicarbazone as antichagasic candidates

The present work reports on the synthesis, biological assaying and docking studies of a series of 12 aryl thiosemicarbazones, which were planned to act over two main enzymes, cruzain and trypanothione reductase. These enzymes are used as targets of trypanocidal activity in Chagas disease control with a minimal mutagenic profile. Three p-nitroaromatic thiosemicarbazones showed high activity against Trypanosoma cruzi in in vitro assays (IC50 < 57 μM), and no mutagenic profile was observed in micronucleous tests. Although the in vitro inhibition test showed that 10-μM doses of eight compounds inhibited cruzain activity, no correlation was found between cruzain inhibition and trypanocidal activity. © 2013 Elsevier Masson SAS. All rights reserved.

Evaluation of biochemical and redox parameters in rats fed with corn grown in soil amended with urban sewage sludge

The increased production of urban sewage sludge requires alternative methods for final disposal. A very promising choice is the use of sewage sludge as a fertilizer in agriculture, since it is rich in organic matter, macro and micronutrients. However, urban sewage sludge may contain toxic substances that may cause deleterious effects on the biota, water and soil, and consequently on humans. There is a lack of studies evaluating how safe the consumption of food cultivated in soils containing urban sewage sludge is. Thus, the aim of this paper was to evaluate biochemical and redox parameters in rats fed with corn produced in a soil treated with urban sewage sludge for a long term. For these experiments, maize plants were grown in soil amended with sewage sludge (rates of 5, 10 and 20. t/ha) or not (control). Four different diets were prepared with the corn grains produced in the field experiment, and rats were fed with these diets for 1, 2, 4, 8 and 12 weeks. Biochemical parameters (glucose, total cholesterol and fractions, triglycerides, aspartate aminotransferase and alanine aminotransferase) as well the redox state biomarkers such as reduced glutathione (GSH), malondialdehyde (MDA), catalase, glutathione peroxidase and butyrylcholinesterase (BuChE) were assessed. Our results show no differences in the biomarkers over 1 or 2 weeks. However, at 4 weeks BuChE activity was inhibited in rats fed with corn grown in soil amended with sewage sludge (5, 10 and 20. t/ha), while MDA levels increased. Furthermore, prolonged exposure to corn cultivated in the highest amount per hectare of sewage sludge (8 and 12 weeks) was associated with an increase in MDA levels and a decrease in GSH levels, respectively. Our findings add new evidence of the risks of consuming food grown with urban sewage sludge. However, considering that the amount and type of toxic substances present in urban sewage sludge varies considerably among different sampling areas, further studies are needed to evaluate sludge samples collected from different sources and/or undergoing different types of treatment. © 2013 Elsevier Inc.

Double effort test for evaluation of aerobic capacity of diet-induced obese rats

Introduction: The literature lacks studies about lactate actions and some limitations in studies involving healthy individuals or patients with some metabolic disorder. Objectives: This study aimed to evaluate the protocol of double effort test for obese-induced rats. Methods: Fourteen male Wistar rats were divided into two groups: Control (Con) and Obese (Obe). The control group was fed with standard chow and water ad libitum. The obese group was fed with standard chow, water ad libitum and hyperlipidic diet. Twelve weeks after the beginning of the hyperlipidic diet, insulin tolerance test, Maximal Lactate Steady State (MLSS) test and the double efforts test were performed. Results: The diet was effective to promote obesity. The obese group decreased insulin sensitivity in approximately 19% (Con = 2.156 ± 0.1187 AU vs Obe = 1.742 ± 0.1551 AU). The lactate concentration and velocity of anaerobic threshold at MLSS test were 3.780 ± 0.09 mmol/L e 18 m.min-1 in both groups. The velocity of anaerobic threshold estimated by double efforts test was 15.59±0.653 m.min-1 in Con group control animals and 16.42±0.672 m.min-1 in Obe group. The double effort test underestimated around 13% and 8.7% the aerobic capacity in control and obese groups respectively, however, presented significant correlation with MLSS (r = 0,88; P < 0,0075 controls / r = 0,92; P < 0,0031 obese). Conclusion: So, the double effort test can be an interesting alternative to evaluate the aerobic capacity for both healthy sedentary and obese animals.

Normative study and evaluation of age influence on Brainstem auditory evoked potentials in mixed breed dogs]

The aim of this paper was to obtain normative data of auditory evoked potentials from 34 mixed breed dogs and evaluate the age influence. The animals were divided in two groups of different ages and auditory evoked potential was performed with a 85dB stimulus intensity. Group 1 included 16 dogs between 1 and 8 years of age, and group 2 included 18 dogs with over 8 years of age. The length and head diameter were measured and there was no statistical difference between the two groups. In group 1, mean latencies of waves I, III, and V were 1.13; 2.64, and 3.45ms, and the intervals I-III, III-V, and I-V were 1.51; 0.81, and 2.32 ms, respectively. In group 2, the mean latencies of waves I, III and V were 1.15, 2.62, and 3.55ms, and the intervals I-III, III-V, and I-V were 1.47, 0.93, and 2.40ms, respectively. The latencies observed in this study were similar to previous studies conducted by other authors. It was observed that significant differences were present for wave V and intervals III-V and I-V latencies when comparing groups with different ages, consequently this characteristic must be considered during BAEP result interpretation.

Neurotoxic action of permethrin in Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae) female ticks. Morphological and cytochemical evaluation of the central nervous system

Studies on the molecular bases of the neurotoxic action of acaricides are found in the literature; but there are no studies of this action on the nervous system of ticks at the cellular level. The present study describes the morphological and cytochemical changes in the synganglion of Rhipicephalus sanguineus semi-engorged females exposed to different concentrations of permethrin, a pyrethroid with recognized neurotoxic action. Permethrin induced the degeneration of the synganglion through a process of apoptosis involving autophagy, characterized by the condensation and margination of the chromatin, formation of blebs in the nuclear envelope and fragmentation of the nucleus, loss of shape of neural cells and integrity of cellular membrane, cytoplasmic shrinkage, and lower levels of acid phosphatase in the nervous tissue as the concentration of permethrin increased. This study provided further evidence of the neurotoxic action of permethrin, which impairs the metabolism of R. sanguineus nervous systems, and consequently the physiology of other systems, dependent on the neural control. These results provide cytochemical and histological confirmation of the neurotoxic action of permethrin, previously inferred from molecular and tick behavioral evidence. © 2013 Elsevier B.V.

Validity and feasibility of qualitative behavior assessment for the evaluation of Nellore cattle temperament

The aims of this study were to assess the validity and the feasibility of the qualitative behavior assessment (QBA) method as indicator of Nellore cattle temperament under field conditions, evaluating its associations with four other traditional methods and weight gain. The temperament and live weight of 2229 Nellore cattle was assessed at approximately 550 days of age. Five measurements of cattle temperament were recorded: flight speed test (FS, in m/s), visual scores of movement in the crush (MOV), crush score (CS), temperament score (TS), and the qualitative behavior assessment method (QBA), by using a list of 12 behavioral based adjectives as descriptors of temperament. Average daily weight gain (ADG) was calculated for each animal. For statistical analysis of QBA data, the Principal Component Analysis was used. A temperament index (TI) was defined for each animal using the scores for the first principal component. Pearson's correlation coefficients were estimated between TI with FS and ADG. A mixed model ANOVA was used to analyze the TI variation as a function of TS, CS, and MOV. The score plot for the first and second principal components was used to classify the cattle in four groups (from very bad to very good temperament). The first principal component explained 49.50% of the variation in the data set, with higher positive loadings for the adjectives 'agitated' and 'active', and higher negative loadings for 'calm' and 'relaxed'. TI was significantly correlated with FS (r=0.49; P<0.01) and ADG (r=-0.10; P<0.01). The means of ADG, FS, and the temperament scores (CS, TS, MOV) differed significantly (P<0.01) among the four groups, from very bad to very good temperament. The QBA method could discriminate different behavioral profiles of Nellore cattle and were in agreement with other traditional methods used as indicators of cattle temperament. Additional studies are needed to assess the inter- and intra-observers reliability and to study its association with physiological parameters. © 2013 Elsevier B.V.

Ultrasound evaluation of common carotid artery blood flow in the Labrador retriever

Background: Doppler ultrasound (DUS) examination provides quantitative and qualitative information concerning the blood flow in veins and arteries, enabling their morphological evaluation and the collection of hemodynamic data. Dogs and cats as well as humans may display neurological signs of brain hypoperfusion secondary to common carotid alterations. Hence, DUS examination might aid in the differential diagnosis of neurological disorders of ischemic origin, among other causes. The objective of this study was to register normal values for systolic peak velocity, minimum diastolic velocity, diameter and resistance index of both common carotid arteries of 12 healthy Labrador retriever dogs between 2 and 5 years of age. By gathering these values, we might be able to improve the sensitivity of hemodynamic studies in clinically important brain disorders. Results: There were no statistical differences between the values for the right and left vessels: the systolic peak velocity was 75.8 ± 16 cm/s, minimum diastolic velocity was 12.2 ± 4 cm/s, common carotid diameter was 0.545 ± 0.063 cm, and resistance index was 0.83 ± 0.07. Conclusions: The results of this study might be used to establish normal parameters for Labrador retriever dogs and thus help in the diagnosis of neurological disorders associated with alterations of the carotid arteries. Similar studies must be performed to evaluate the same parameters in other dog breeds of different sizes and skull conformations. © 2013 Svicero et al.; licensee BioMed Central Ltd.