Methylenetetrahydrofolate reductase gene polymorphism in diabetes and obesity

Methylenetetrahydrofolate reductase (MTHFR) polymorphism may play an important role in the pathophysiology of obesity and diabetes accompanied by obesity due to its influence on plasma homocysteine levels. There are significant and sometimes very strong relationship between levels of homocysteine and several multi-system diseases including CHD and CVA. To examine the association between MTHFR gene C677T polymorphism in diabetes and obesity with serum homocysteine levels. A total of 682 subjects were recruited in four groups (Normal, obese, diabetic and obese and diabetics). MTHFR gene C677T polymorphism was detected using PCR-RFLP technique. Serum homocysteine levels were measured using HPLC. There was a significant increase in the mean serum homocysteine levels in subjects carrying TT genotype (34.6 ± 26.5) compared to subjects carrying CC (15.1 ± 8) or CT genotype (16.4 ± 7.8) (P < 0.000). We found no significant differences for MTHFR allele and genotype frequencies between different groups. Our data have confirmed the association between serum homocysteine levels and MTHFR C677T genotype reported in other populations.     

Change in membrane fatty acid compositions and cold-induced responses in chickpea

Plant cells often increase cold tolerance by reprogramming their genes expression which results in adjusted metabolic alternations, a process enhanced under cold acclimation (CA) phase. In present study, we assessed the changes of membrane fatty acid compositions and defense machine (like antioxidative enzymes) along with damage indexes like electrolyte leakage index (ELI) and malondialdehyde (MDA) during CA, cold stress (CS) and recovery (R) phases in chickpea (Cicer arietinum L.). Results showed an increase in unsaturated fatty acids ratio compare to saturated ones which is a sign of cold tolerance especially after CA phase. Antioxidant enzymes had an important role during CA and R phases while CS affected their activity which can be a sign for associating other metabolites or enzymes activities to create cold tolerance in plants. To investigation of enzymes assay under experimental treatments, the expression pattern of some enzymes including superoxide dismutase (sod), catalase (cat) and lipoxygenase (lox) was studied using quantitative real time PCR. LOX activity has shown a bilateral behavior: a positive relation with membrane damage index in CA and an interesting link with double bond index (DBI) in CS indicating probably its role in secondary metabolites like jasmonic acid signaling pathway. It was suggested that increased DBI and low LOX activity under CS could be a reason for plant cold tolerance.     

Astrocyte- neuron interaction as a mechanism responsible for generation of neural synchrony: a study based on modeling and experiments

Neural synchronization is considered as an important mechanism for information processing. In addition, based on recent neurophysiologic findings, it is believed that astrocytes regulate the synaptic transmission of neuronal networks. Therefore, the present study focused on determining the functional contribution of astrocytes in neuronal synchrony using both computer simulations and extracellular field potential recordings. For computer simulations, as a first step, a minimal network model is constructed by connecting two Morris-Lecar neuronal models. In this minimal model, astrocyte-neuron interactions are considered in a functional-based procedure. Next, the minimal network is extended and a biologically plausible neuronal population model is developed which considers functional outcome of astrocyte-neuron interactions too. The employed structure is based on the physiological and anatomical network properties of the hippocampal CA1 area. Utilizing these two different levels of modeling, it is demonstrated that astrocytes are able to change the threshold value of transition from synchronous to asynchronous behavior among neurons. In this way, variations in the interaction between astrocytes and neurons lead to the emergence of synchronous/asynchronous patterns in neural responses. Furthermore, population spikes are recorded from CA1 pyramidal neurons in rat hippocampal slices to validate the modeling results. It demonstrates that astrocytes play a primary role in neuronal firing synchronicity and synaptic coordination. These results may offer a new insight into understanding the mechanism by which astrocytes contribute to stabilizing neural activities.     

Compression or tension? The stress distribution in the proximal femur

Background  

Questions regarding the distribution of stress in the proximal human femur have never been adequately resolved. Traditionally, by considering the femur in isolation, it has been believed that the effect of body weight on the projecting neck and head places the superior aspect of the neck in tension. A minority view has proposed that this region is in compression because of muscular forces pulling the femur into the pelvis. Little has been done to study stress distributions in the proximal femur. We hypothesise that under physiological loading the majority of the proximal femur is in compression and that the internal trabecular structure functions as an arch, transferring compressive stresses to the femoral shaft.     

Regional differences in WT-1 and Tcf21 expression during ventricular development: implications for myocardial compaction

Background

Morphological and functional differences of the right and left ventricle are apparent in the adult human heart. A differential contribution of cardiac fibroblasts and smooth muscle cells (populations of epicardium-derived cells) to each ventricle may account for part of the morphological-functional disparity. Here we studied the relation between epicardial derivatives and the development of compact ventricular myocardium.

Results

Wildtype and Wt1^CreERT2/+ reporter mice were used to study WT-1 expressing cells, and Tcf21^lacZ/+ reporter mice and PDGFRα^-/-;Tcf21^LacZ/+ mice to study the formation of the cardiac fibroblast population. After covering the heart, intramyocardial WT-1+ cells were first observed at the inner curvature, the right ventricular postero-lateral wall and left ventricular apical wall. Later, WT-1+ cells were present in the walls of both ventricles, but significantly more pronounced in the left ventricle. Tcf21-^LacZ + cells followed the same distribution pattern as WT-1+ cells but at later stages, indicating a timing difference between these cell populations. Within the right ventricle, WT-1+ and Tcf21-lacZ+ cell distribution was more pronounced in the posterior inlet part. A gradual increase in myocardial wall thickness was observed early in the left ventricle and at later stages in the right ventricle. PDGFRα^-/-;Tcf21^LacZ/+ mice showed deficient epicardium, diminished number of Tcf21-^LacZ + cells and reduced ventricular compaction.

Conclusions

During normal heart development, spatio-temporal differences in contribution of WT-1 and Tcf21-^LacZ + cells to right versus left ventricular myocardium occur parallel to myocardial thickening. These findings may relate to lateralized differences in ventricular (patho)morphology in humans.     

Four Categories of Viral Infection Describe the Health Status of Honey Bee Colonies

Honey bee virus prevalence data are an essential prerequisite for managing epidemic events in a population. A survey study was carried out for seven viruses in colonies representing a healthy Danish honey bee population. In addition, colonies from apiaries with high level Varroa infestation or high level of winter mortality were also surveyed. Results from RT-qPCR showed a considerable difference of virus levels between healthy and sick colonies. In the group of healthy colonies, no virus was detected in 36% of cases, while at least one virus was found in each of the sick colonies. Virus titers varied among the samples, and multiple virus infections were common in both groups with a high prevalence of Sacbrood virus (SBV), Black queen cell virus (BQCV) and Deformed wing virus (DWV). Based on the distribution of virus titers, we established four categories of infection: samples free of virus (C = 0), samples with low virus titer (estimated number of virus copies 0 < C < 10³), samples with medium virus titer (10³ ≤ C < 10⁷) and samples with high virus titer (C ≥ 10⁷). This allowed us to statistically compare virus levels in healthy and sick colonies. Using categories to communicate virus diagnosis results to beekeepers may help them to reach an informed decision on management strategies to prevent further spread of viruses among colonies.     

Variation in the Essential Oil Composition,Antioxidant Capacity,and Physiological Characteristics of Pelargonium graveolens L. Inoculated with Two Species of Mycorrhizal Fungi Under Water Deficit Conditions

In recent years, the application of arbuscular mycorrhizal fungi (AMF) has been considered to be an important strategy for improving crop yield and quality. In the present study, a factorial experiment based on a complete randomized design with two factors was performed to investigate the effect of AMF and water stress on the essential oil (EO) composition, antioxidant activity, and physiological and morphological characteristics of rose-scented geranium (Pelargonium graveolens L.). The factors included AMF inoculation (Rhizophagus intraradices, Funneliformis mosseae, and a mixture of both species) and irrigation levels [well-watered (WW), moderate drought stress (MDS), and severe drought stress (SDS)]. The main EO constituents were citronellol (31–37%) and geraniol (9–14%) in all treatments. Under water-stress conditions, some constituents increased, such as geraniol and geranyl formate, whereas others decreased, such as linalool, menthone and rose oxide. Overall, the highest amount of citronellol (37.3%) and geraniol (14.8%) was obtained in the plants inoculated with F. mosseae and R. intraradices under WW and MDS conditions, respectively. Antioxidant activity, total flavonoids, and phenolics were increased because of AMF inoculation, whereas a different trend was observed for the phenolic and flavonoid contents under water-stress conditions. Furthermore, water deficit elevated the amount of soluble carbohydrates as well as the proline content, whereas the amount of proline was lower in inoculated plants than in non-inoculated ones. All the growth parameters were improved in the AMF-inoculated plants compared to non-inoculated ones under different irrigation regimes. Drought conditions decreased the photosynthetic pigments and efficiency, whereas AMF plants ameliorated the adverse effect of drought conditions. In general, mycorrhizal inoculation resulted in an improvement in the growth parameters as well as the phytochemical and physiological characteristics of rose-scented geranium.