Supplementation With Omega 3 in a Diet With Omega 9 Fatty Acids. Study on Serum, Thymus and Brain of Growing Rat

Objectives Fatty acids have an important role in nutrition. The objective was to analyze the effect of diet containing olive oil, with and without the supplementation with omega 3, on serum, thymus and brain's fatty acid profiles of growing rats. Methods Weanling Wistar rats fed during 10 days a diet containing olive oil as fat (O group). Other group received the same diet supplemented with 24mg/day of fish oil (OS group). Control group(C) received diet according AIN´93. Serum, thymus and brain's fatty acids profiles were determined by gas chromatography. Statistical analysis used ANOVA. Results Results (%Area) were expressed as the Mean ± SD: SERUM: OLEIC O:23.44 ± 3.68a; OS:18.31 ± 2.22a; C:10.60 ± 2.01b; LINOLEIC(LA) O:12.44 ± 1.65b; OS:12.98 ± 4.31b; C:18.27 ± 2.81a; LINOLENIC(ALA) O:0.30 ± 0.09b; OS:0.32 ± 0.08b; C:0.92 ± 0.34a; EPA O:0.65 ± 0.17b; OS:1.63 ± 0.49a; C:0.80 ± 0.23b; DHA: O:1.57 ± 0.58b; OS:4.00 ± 1.70a; C:1.33 ± 0.19b. THYMUS: OLEIC O:21.54 ± 5.92; OS:24.40 ± 5.04; C:18.22 ± 3.23; LINOLEIC O:5.90 ± 0.56b; OS:6.50 ± 0.61b; C:10.89 ± 2.18a; ALA O:0.27 ± 0.02b; OS:0.30 ± 0.07b; C:0.49 ± 0.19a; EPA O:0.49 ± 0.28; OS:0.50 ± 0.13; C:0.50 ± 0.12; DHA O:0.47 ± 0.10b; OS:0.70 ± 0.12a; C:0.52 ± 0.16b. BRAIN: OLEIC O:13.11 ± 2.64; OS:12.94 ± 1.07; C:13.14 ± 1.56; LA O:1.17 ± 0.46; OS:1.05 ± 0.33; C:1.26 ± 0.19; ALA O:0.15 ± 0.03; OS:0.12 ± 0.04; C:0.16 ± 0.06; EPA O:0.46 ± 0.18; OS:0.38 ± 0.09; C:0.33 ± 0.07; DHA: O:11.39 ± 2.04; OS:11.32 ± 1.69; C:11.66 ± 1.63. Means with one letter (a, b) in common, were not significantly different (p > 0.05). In sera, O and OS showed lower ALA and LA and higher oleic levels, compared to C. OS presented high levels of EPA and DHA. In thymus, O and OS groups showed lower levels of ALA and LA than C. DHA only increased in the OS group. No changes were presented in the brain. Conclusions The results suggest that olive oil exacerbated omega-9 family with diminution of essential fatty acids while organism tries to sustain brain essential fatty acids. Fish oil supplementation increased serum and thymus DHA levels, not modifying low levels of other essential fatty acids. Another source of supplementation may be convenient to analyze. Funding Sources Supported by University of Buenos Aires, Argentina.

Social and environmental correlates of rat complaints in Chicago

Urban rats are widely distributed pests that have negative effects on public health and property. It is crucial to understand their distribution to inform control efforts and address drivers of rat presence. Analysing public rat complaints can help assess urban rat distribution and identify factors supporting rat populations. Both social and environmental factors could promote rat complaints and must be integrated to understand rat distributions. We analysed rat complaints made between 2011 and 2017 in Chicago, a city with growing rat problems and stark wealth inequality. We examined whether rat complaints at the census tract level are associated with factors that could influence rat abundance, rats’ visibility to humans, and the likelihood of people making a complaint. Complaints were significantly positively correlated with anthropogenic factors hypothesized to promote rat abundance (restaurants, older buildings, garbage complaints, and dog waste complaints) or rat visibility (building construction/demolition activity), and factors hypothesized to increase the likelihood of complaining (human population density, more owner-occupied homes); we also found that complaints were highest in the summer. Our results suggest that conflicts between residents and rats are mainly driven by seasonal variation in rat abundance and human activity and could be mitigated with strategies such as securing food waste from residential and commercial sources. Accounting for social factors such as population density, construction and demolition activity, and home ownership versus rental can also help cities more accurately predict blocks at higher risk of rat conflicts.

Nondestructive Assessment of Growing Rat Tibial Mechanical Properties Under Three-Point Bending: A Microcomputed Tomography Based Finite Element Study

Microcomputed tomography (micro-CT) based finite element models (FEM) are efficient tools to assess bone mechanical properties. Although they have been developed for different animal models, there is still a lack of data for growing rat long bone models. This study aimed at developing and calibrating voxel-based FEMs using micro-CT scans and experimental data. Twenty-four tibiae were extracted from rats aged 28, 56, and 84 days old (d.o.) (n = 8/group), and their stiffness values were evaluated using three-point bending tests. Prior to testing, tibiae were scanned, reconstructed, and converted into FEM composed of heterogeneous bone properties based on pixel grayscales. Three element material laws (one per group) were calibrated using back-calculation process based on experimental bending data. Two additional specimens per group were used for model verification. The calibrated rigidity–density (E-ρ) relationships were different for each group: E28 = 10,320·ρash3.45; E56 = 43,620·ρash4.41; E84 = 20,090·ρash2.0. Obtained correlations between experimental and FEM stiffness values were 0.43, 0.10, and 0.66 with root-mean-square error (RMSE) of 14.4%, 17.4%, and 15.2% for 28, 56, and 84 d.o. groups, respectively. Prediction errors were less than 13.5% for 28 and 84 d.o. groups but reached 57.1% for the 56 d.o. group. Relationships between bone physical and mechanical properties were found to change during the growth, similarly to bending stiffness values, which increased with bone development. The reduced correlation observed for the 56 d.o. group may be related to the pubescent transition at that age group. These FE models will be useful for investigation of bone behavior in growing rats.

The cartilage degeneration in a growing rat experimental model of developmental trochlear dysplasia is associated with activation of PI3K/AKT signal pathway

Background As one of the lower extremity deformities in human, trochlear dysplasia is a commonly encountered disease. However, the molecular mechanism of cartilage degeneration in trochlear dysplasia is indefinite yet. It was apparent to all that PI3K/AKT signal pathway is extremely significant in regulating the pathophysiological process of cartilage degeneration. The purpose of this research is to discuss the correlation between PI3K/AKT signal pathway and trochlear dysplasia cartilage degeneration. Materials and methods 120 female Sprague-Dawley rats at 4 weeks of age were separate into control group and experimental group randomly. The distal femurs were isolated from the experimental and unsurgeried control group at the point of the 4, 8, 12 weeks, correspondingly. Micro-CT and histological examination were carried out to investigate the anatomical structure and cartilage changes of the trochlear. Subsequently, the expression of PI3K/AKT, TGFβ1 and ADAMTS-4 in cartilage were investigated by immunohistochemistry and quantitative real-time polymerase chain reaction (qRT-PCR). Results In the experimental group, the trochlear dysplasia model was successfully established at 8 weeks after surgery. Moreover, the cartilage degeneration was found from 8 weeks, with continued higher protein and mRNA expression of PI3K/AKT, TGFβ1 and ADAMTS-4 compared with the control group. Conclusions This research suggested that patellar instability may lead to trochlear dysplasia in growing rats. Moreover, trochlear dysplasia was probably one of the causes of patellofemoral osteoarthritis and the cartilage degeneration in trochlear dysplasia might be associate with activation of PI3K/AKT signal pathway. However, more research was required to clarify the underlying mechanisms.