Oxytocin Sustained Release Using Natural Rubber Latex Membranes

The demand for biomaterials with properties that provide sustained release of substances with pharmacological interest is constant. One candidate for applications in this area is the Natural Rubber Latex (NRL) extracted from the rubber tree Hevea brasiliensis. Recent studies indicate the NRL as a matrix for sustained release, showing promising results for biomedical applications such as: can stimulate natural angiogenesis and is capable of adhering cells on its surface, promoting the replacement and regeneration of tissue. So, the NRL is an excellent candidate to propitiate the sustained release of peptides of pharmacological interest such as oxytocin, a hormonal peptide which has the function to promote uterine muscle contractions and reduce bleeding during childbirth, and stimulate the release of breast milk. Results demonstrated that 90 μg mL^?1 (45 %) of the incorporated peptide in Natural Rubber Latex Biomedical (NRLb) functionalized membranes was released at 10 h in phosphate-buffered saline (PBS) solution. Swelling kinetics assay showed that the NRLb membranes are able to absorb over a period of 16 h up to 1.08 grams of water per grams of membrane. Scanning electron microscopy showed that the peptide was adsorbed on the surface and within NRLb membrane. Fourier transform infrared and Derivative Thermogravimetric analysis indicated that oxytocin did not interacted chemically with the membrane. Furthermore, hemolysis of erythrocytes, quantified spectrophotometrically using materials (Oxytocin, NRLb, and NRLb + Oxytocin) showed no hemolytic effects up to 100 μg mL^?1 (compounds and mixtures), indicating no detectable disturbance of the red blood cell membranes. Based on these results it was possible to conclude that the NRLb has shown effectiveness as a model in the release of peptides with pharmacological interest.     

In vivo assessment of subcutaneous fat in dogs by real-time ultrasonography and image analysis

Background

Systems for estimating body condition score (BCS) are currently used in canine practice to monitor fatness levels. These tools are cheap and easy to use but lack the necessary precision to monitor small changes in body fat, particularly during weight control treatments or in research. The present work aims to study the application of real-time ultrasonography (RTU) together with image analysis in the assessment of subcutaneous fat depots in dogs. Ultrasound images were collected from five anatomical locations (chest, flank, abdomen, thigh and lumbar) from 28 healthy dogs of different breeds and with a body weight (BW) ranging from 5.2 to 33.0 kg. BCS was collected by visual appraisal using a 5-point scale. Subcutaneous fat thickness (SFT) was estimated from RTU images, using the average of three measurements taken in fat deposits located above the muscles represented in each image. Correlations were established between SFT and BW or BCS as well as a classification of BCS-based fatness [overweight (BCS = 4), ideal (BCS = 3) and lean (BCS = 2)].

Results

SFT was found to differ between the five regions considered (P < 0.001). Abdomen and thigh were the areas displaying the widest variation for the different dogs included in the study and also those correlating most with BW, in contrast to the chest, which showed the least variation. Overall, a strong correlation was found between BCS and SFT. The highest correlations were established for the flank, abdomen and lumbar areas. In every anatomical area, a decrease in SFT was observed across all three BCS classes, ranging from 48 to 65 % among overweight and ideal dogs, and from 46 to 83 % among ideal and lean dogs.

Conclusions

Preliminary data showed that within this population there was a strong correlation between BCS and SFT estimated from RTU images. It was also observed that RTU measurements for fat thickness differed among the anatomical points surveyed suggesting differences in their sensitivity to a change in BCS. The images displaying the best prediction value for fatness variations were those collected at the lumbar and abdomen areas.

     

Temporal Variation in Physiological Biomarkers in Black Flying-Foxes (<Emphasis Type="Italic">Pteropus alecto</Emphasis>), Australia

Bats of the genus Pteropus (Pteropodidae) are recognised as the natural host of multiple emerging pathogenic viruses of animal and human health significance, including henipaviruses, lyssaviruses and ebolaviruses. Some studies have suggested that physiological and ecological factors may be associated with Hendra virus infection in flying-foxes in Australia; however, it is essential to understand the normal range and seasonal variability of physiological biomarkers before seeking physiological associations with infection status. We aimed to measure a suite of physiological biomarkers in P. alecto over time to identify any seasonal fluctuations and to examine possible associations with life-cycle and environmental stressors. We sampled 839 adult P. alecto in the Australian state of Queensland over a 12-month period. The adjusted population means of every assessed hematologic and biochemical parameter were within the reported reference range on every sampling occasion. However, within this range, we identified significant temporal variation in these parameters, in urinary parameters and body condition, which primarily reflected the normal annual life cycle. We found no evident effect of remarkable physiological demands or nutritional stress, and no indication of clinical disease driving any parameter values outside the normal species reference range. Our findings identify underlying temporal physiological changes at the population level that inform epidemiological studies and assessment of putative physiological risk factors driving Hendra virus infection in P. alecto. More broadly, the findings add to the knowledge of Pteropus populations in terms of their relative resistance and resilience to emerging infectious disease.     

Distribution of Spotted Fever Group Rickettsiae in Hard Ticks (Ixodida: Ixodidae) from Panamanian Urban and Rural Environments (2007–2013)

Tick-borne rickettsiosis is an important emerging disease in Panama; to date, there have been 12 confirmed cases, including eight fatalities. To evaluate the distribution of rickettsiae in Panamanian ticks, we collected questing and on-host ticks in urban and rural towns in elevations varying between 0 and 2300 m. A total of 63 sites (13 urban and 50 rural towns) were used to develop models of spatial distributions. We found the following tick species: Rhipicephalus sanguineus s.l. (present in 54 of 63 towns and cities), Amblyomma mixtum (45/63), Dermacentor nitens (40/63), A. ovale (37/63), Rhipicephalus microplus (33/63), A. oblongoguttatum (33/63), Ixodes affinis (3/63), and Ixodes boliviensis (2/63). Rhipicephalus sanguineus s.l. was present in urban and rural towns, and other species were present only in rural towns. DNA was extracted from 408 R. sanguineus s.l., 387 A. mixtum, 103 A. ovale, and 11 A. oblongoguttatum and later tested for rickettsiae genes using PCR. Rickettsia DNA was detected in ticks from 21 of 63 localities. Rickettsia rickettsii was detected in five A. mixtum (1.29%), and Candidatus “Rickettsia amblyommii” was found in 138 A. mixtum (35%), 14 R. sanguineus (3.4%), and one A. ovale (0.9%). These results suggest that much of rural Panama is suitable for the expansion of tick populations and could favor the appearance of new tick-borne rickettsiosis outbreaks.     

Genetic Variants in the Bone Morphogenic Protein Gene Family Modify the Association between Residential Exposure to Traffic and Peripheral Arterial Disease

There is a growing literature indicating that genetic variants modify many of the associations between environmental exposures and clinical outcomes, potentially by increasing susceptibility to these exposures. However, genome-scale investigations of these interactions have been rarely performed particularly in the case of air pollution exposures. We performed race-stratified genome-wide gene-environment interaction association studies on European-American (EA, N = 1623) and African-American (AA, N = 554) cohorts to investigate the joint influence of common single nucleotide polymorphisms (SNPs) and residential exposure to traffic (“traffic exposure”)—a recognized vascular disease risk factor—on peripheral arterial disease (PAD). Traffic exposure was estimated via the distance from the primary residence to the nearest major roadway, defined as the nearest limited access highways or major arterial. The rs755249-traffic exposure interaction was associated with PAD at a genome-wide significant level (P = 2.29x10^-8) in European-Americans. Rs755249 is located in the 3’ untranslated region of BMP8A, a member of the bone morphogenic protein (BMP) gene family. Further investigation revealed several variants in BMP genes associated with PAD via an interaction with traffic exposure in both the EA and AA cohorts; this included interactions with non-synonymous variants in BMP2, which is regulated by air pollution exposure. The BMP family of genes is linked to vascular growth and calcification and is a novel gene family for the study of PAD pathophysiology. Further investigation of BMP8A using the Genotype Tissue Expression Database revealed multiple variants with nominally significant (P < 0.05) interaction P-values in our EA cohort were significant BMP8A eQTLs in tissue types highlight relevant for PAD such as rs755249 (tibial nerve, eQTL P = 3.6x10^-6) and rs1180341 (tibial artery, eQTL P = 5.3x10^-6). Together these results reveal a novel gene, and possibly gene family, associated with PAD via an interaction with traffic air pollution exposure. These results also highlight the potential for interactions studies, particularly at the genome scale, to reveal novel biology linking environmental exposures to clinical outcomes.     

Impact of the B Cell Growth Factor APRIL on the Qualitative and Immunological Characteristics of Atherosclerotic Plaques

Studies on the role of B lymphocytes in atherosclerosis development, have yielded contradictory results. Whereas B lymphocyte-deficiency aggravates atherosclerosis in mice; depletion of mature B lymphocytes reduces atherosclerosis. These observations led to the notion that distinct B lymphocyte subsets have different roles. B1a lymphocytes exert an atheroprotective effect, which has been attributed to secretion of IgM, which can be deposited in atherosclerotic lesions thereby reducing necrotic core formation. Tumor necrosis factor (TNF)-family member ‘A Proliferation-Inducing Ligand’ (APRIL, also known as TNFSF13) was previously shown to increase serum IgM levels in a murine model. In this study, we investigated the effect of APRIL overexpression on advanced lesion formation and composition, IgM production and B cell phenotype. We crossed APRIL transgenic (APRIL-Tg) mice with ApoE knockout (ApoE^-/-) mice. After a 12-week Western Type Diet, ApoE^-/-APRIL-Tg mice and ApoE^-/- littermates showed similar increases in body weight and lipid levels. Histologic evaluation showed no differences in lesion size, stage or necrotic area. However, smooth muscle cell (α-actin stain) content was increased in ApoE^-/-APRIL-Tg mice, implying more stable lesions. In addition, increases in both plaque IgM deposition and plasma IgM levels were found in ApoE^-/-APRIL-Tg mice compared with ApoE^-/- mice. Flow cytometry revealed a concomitant increase in peritoneal B1a lymphocytes in ApoE^-/-APRIL-Tg mice. This study shows that ApoE^-/-APRIL-Tg mice have increased oxLDL-specific serum IgM levels, potentially mediated via an increase in B1a lymphocytes. Although no differences in lesion size were found, transgenic ApoE^-/-APRIL-Tg mice do show potential plaque stabilizing features in advanced atherosclerotic lesions.     

Homogeneous Canine Chest Phantom Construction: A Tool for Image Quality Optimization

Digital radiographic imaging is increasing in veterinary practice. The use of radiation demands responsibility to maintain high image quality. Low doses are necessary because workers are requested to restrain the animal. Optimizing digital systems is necessary to avoid unnecessary exposure, causing the phenomenon known as dose creep. Homogeneous phantoms are widely used to optimize image quality and dose. We developed an automatic computational methodology to classify and quantify tissues (i.e., lung tissue, adipose tissue, muscle tissue, and bone) in canine chest computed tomography exams. The thickness of each tissue was converted to simulator materials (i.e., Lucite, aluminum, and air). Dogs were separated into groups of 20 animals each according to weight. Mean weights were 6.5 ± 2.0 kg, 15.0 ± 5.0 kg, 32.0 ± 5.5 kg, and 50.0 ± 12.0 kg, for the small, medium, large, and giant groups, respectively. The one-way analysis of variance revealed significant differences in all simulator material thicknesses (p < 0.05) quantified between groups. As a result, four phantoms were constructed for dorsoventral and lateral views. In conclusion, the present methodology allows the development of phantoms of the canine chest and possibly other body regions and/or animals. The proposed phantom is a practical tool that may be employed in future work to optimize veterinary X-ray procedures.     

Inclusion of Dominance Effects in the Multivariate GBLUP Model

New proposals for models and applications of prediction processes with data on molecular markers may help reduce the financial costs of and identify superior genotypes in maize breeding programs. Studies evaluating Genomic Best Linear Unbiased Prediction (GBLUP) models including dominance effects have not been performed in the univariate and multivariate context in the data analysis of this crop. A single cross hybrid construction procedure was performed in this study using phenotypic data and actual molecular markers of 4,091 maize lines from the public database Panzea. A total of 400 simple hybrids resulting from this process were analyzed using the univariate and multivariate GBLUP model considering only additive effects additive plus dominance effects. Historic heritability scenarios of five traits and other genetic architecture settings were used to compare models, evaluating the predictive ability and estimation of variance components. Marginal differences were detected between the multivariate and univariate models. The main explanation for the small discrepancy between models is the low- to moderate-magnitude correlations between the traits studied and moderate heritabilities. These conditions do not favor the advantages of multivariate analysis. The inclusion of dominance effects in the models was an efficient strategy to improve the predictive ability and estimation quality of variance components.     

Electroencephalographic Patterns in Chronic Pain: A Systematic Review of the Literature

The main objective of this study is to review and summarize recent findings on electroencephalographic patterns in individuals with chronic pain. We also discuss recent advances in the use of quantitative Electroencephalography (qEEG) for the assessment of pathophysiology and biopsychosocial factors involved in its maintenance over time. Data collection took place from February 2014 to July 2015 in PubMed, SciELO and PEDro databases. Data from cross-sectional studies and longitudinal studies, as well as clinical trials involving chronic pain participants were incorporated into the final analysis. Our primary findings related to chronic pain were an increase of theta and alpha EEG power at rest, and a decrease in the amplitude of evoked potentials after sensory stimulation and cognitive tasks. This review suggests that qEEG could be considered as a simple and objective tool for the study of brain mechanisms involved in chronic pain, as well as for identifying the specific characteristics of chronic pain condition. In addition, results show that qEEG probably is a relevant outcome measure for assessing changes in therapeutic studies.     

Mycobacterium leprae-Infected Macrophages Preferentially Primed Regulatory T Cell Responses and Was Associated with Lepromatous Leprosy

Background

The persistence of Mycobacterium leprae (M. leprae) infection is largely dependent on the types of host immune responses being induced. Macrophage, a crucial modulator of innate and adaptive immune responses, could be directly infected by M. leprae. We therefore postulated that M. leprae-infected macrophages might have altered immune functions.

Methodology/Principal Findings

Here, we treated monocyte-derived macrophages with live or killed M. leprae, and examined their activation status and antigen presentation. We found that macrophages treated with live M. leprae showed committed M2-like function, with decreased interleukin 1 beta (IL-1beta), IL-6, tumor necrosis factor alpha (TNF-alpha) and MHC class II molecule expression and elevated IL-10 and CD163 expression. When incubating with naive T cells, macrophages treated with live M. leprae preferentially primed regulatory T (Treg) cell responses with elevated FoxP3 and IL-10 expression, while interferon gamma (IFN-gamma) expression and CD8⁺ T cell cytotoxicity were reduced. Chromium release assay also found that live M. leprae-treated macrophages were more resistant to CD8⁺ T cell-mediated cytotoxicity than sonicated M. leprae-treated monocytes. Ex vivo studies showed that the phenotype and function of monocytes and macrophages had clear differences between L-lep and T-lep patients, consistent with the in vitro findings.

Conclusions/Significance

Together, our data demonstrate that M. leprae could utilize infected macrophages by two mechanisms: firstly, M. leprae-infected macrophages preferentially primed Treg but not Th1 or cytotoxic T cell responses; secondly, M. leprae-infected macrophages were more effective at evading CD8⁺ T cell-mediated cytotoxicity.