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991.
Ghoochani A Shabani K Peymani M Ghaedi K Karamali F Karbalaei K Tanhaie S Salamian A Esmaeili A Valian-Borujeni S Hashemi M Nasr-Esfahani MH Baharvand H 《Differentiation; research in biological diversity》2012,83(1):60-67
Peroxisome proliferator activated receptor γ, belongs to PPARs, which exerts various metabolic functions including differentiation process. To testify the importance of PPARγ in neural differentiation of mouse embryonic stem cells (mESCs), its expression level was assessed. Data revealed an elevation in expression level of PPARγ when neural precursors (NPs) are formed upon retinoic acid treatment. Thus, involvement of PPARγ in two stages of neural differentiation of mESCs, during and post-NPs formation was examined by application of its agonist and antagonist. Our results indicated that PPARγ inactivation via treatment with GW9662 during NPs formation, reduced expression of neural precursor and neural (neuronal and astrocytes) markers. However, PPARγ inactivation by antagonist treatment post-NPs formation stage only decreased the expression of mature astrocyte marker (Gfap) suggesting that inactivation of PPARγ by antagonist decreased astrocyte differentiation. Here, we have demonstrated the stage dependent role of PPARγ modulation on neural differentiation of mESCs by retinoic acid treatment for the first time. 相似文献
992.
993.
Phloridzin reduces blood glucose levels and improves lipids metabolism in streptozotocin-induced diabetic rats 总被引:2,自引:0,他引:2
Najafian M Jahromi MZ Nowroznejhad MJ Khajeaian P Kargar MM Sadeghi M Arasteh A 《Molecular biology reports》2012,39(5):5299-5306
Phloridzin is the specific and competitive inhibition of sodium/glucose cotransporters in the intestine (SGLT1) and kidney
(SGLT2). This property which could be useful in the management of postprandial hyperglycemia in diabetes and related disorders.
Phloridzin is one of the dihydrochalcones typically contained in apples and in apple-derived products. The effect of phloridzin
orally doses 5, 10, 20 and 40 mg/kg body weight on diabetes was tested in a streptozotocin-induced rat model of diabetes type
1. From beneficial effect of this compound is significant reduction of blood glucose levels and improve dyslipidemia in diabetic
rats. As a well-known consequence of becoming diabetic, urine volume and water intake were significantly increased. Administration
of phloridzin reduced urine volume and water intake in a dose-dependent manner. Phloretin decreases of food consumption, as
well as a marked lowering in the weight. In conclusion, this compound could be proposed as an antihyperglycemic and antihyperlipidemic
agent in diabetes and potential therapeutic in obesity. 相似文献
994.
Hosseini Tafreshi SA Shariati M Mofid MR Khayam Nekui M Esmaeili A 《Molecular biology reports》2012,39(3):2169-2178
VIGS (virus induced gene silencing) is considered as a powerful genomics tool for characterizing the function of genes in
a few closely related plant species. The investigations have been carried out mainly in order to test if a pre-existing VIGS
vector can serve as an efficient tool for gene silencing in a diverse array of plant species. Another route of investigation
has been the constructing of new viral vectors to act in their hosts. Our approach was the creation of a heterologous system
in which silencing of endogenous genes was achieved by sequences isolated from evolutionary remote species. In this study,
we showed that a TRV-based vector cloned with sequences from a gymnosperm, Taxus baccata L. silenced the endogenous phytoene desaturase in an angiosperm, N. benthamiana. Our results showed that inserts of between 390 and 724 bp isolated from a conserved fragment of the Taxus PDS led to silencing of its homolog in tobacco. The real time analysis indicated that the expression of PDS was reduced 2.1- to 4.0-fold in pTRV-TbPDS infected plants compared with buffer treated plants. Once the best insert is identified and the conditions are optimized
for heterologous silencing by pTRV-TbPDS in tobacco, then we can test if TRV can serve as an efficient silencing vector in Taxus. This strategy could also be used to silence a diverse array of genes from a wide range of species which have no VIGS protocol.
The results also showed that plants silenced heterologously by the VIGS system a minimally affected with respect to plant
growth which may be ideal for studying the genes that their complete loss of function may lead to decrease of plant growth
or plant death. 相似文献
995.
A detailed 3D anatomical model of the patellofemoral joint was developed to study the tracking, force, contact and stability characteristics of the joint. The quadriceps was considered to include six components represented by 15 force vectors. The patellar tendon was modeled using four bundles of viscoelastic tensile elements. Each of the lateral and medial retinaculum was modeled by a three-bundle nonlinear spring. The femur and patella were considered as rigid bodies with their articular cartilage layers represented by an isotropic viscoelastic material. The geometrical and tracking data needed for model simulation, as well as validation of its results, were obtained from an in vivo experiment, involving MR imaging of a normal knee while performing isometric leg press against a constant 140 N force. The model was formulated within the framework of a rigid body spring model and solved using forth-order Runge-Kutta, for knee flexion angles between zero and 50 degrees. Results indicated a good agreement between the model predictions for patellar tracking and the experimental results with RMS deviations of about 2 mm for translations (less than 0.7 mm for patellar mediolateral shift), and 4 degrees for rotations (less than 3 degrees for patellar tilt). The contact pattern predicted by the model was also consistent with the results of the experiment and the literature. The joint contact force increased linearly with progressive knee flexion from 80 N to 210 N. The medial retinaculum experienced a peak force of 18 N at full extension that decreased with knee flexion and disappeared entirely at 20 degrees flexion. Analysis of the patellar time response to the quadriceps contraction suggested that the muscle activation most affected the patellar shift and tilt. These results are consistent with the recent observations in the literature concerning the significance of retinaculum and quadriceps in the patellar stability. 相似文献
996.
Fishman M Jacono FJ Park S Jamasebi R Thungtong A Loparo KA Dick TE 《Journal of applied physiology (Bethesda, Md. : 1985)》2012,113(2):297-306
The Poincaré plot is a popular two-dimensional, time series analysis tool because of its intuitive display of dynamic system behavior. Poincaré plots have been used to visualize heart rate and respiratory pattern variabilities. However, conventional quantitative analysis relies primarily on statistical measurements of the cumulative distribution of points, making it difficult to interpret irregular or complex plots. Moreover, the plots are constructed to reflect highly correlated regions of the time series, reducing the amount of nonlinear information that is presented and thereby hiding potentially relevant features. We propose temporal Poincaré variability (TPV), a novel analysis methodology that uses standard techniques to quantify the temporal distribution of points and to detect nonlinear sources responsible for physiological variability. In addition, the analysis is applied across multiple time delays, yielding a richer insight into system dynamics than the traditional circle return plot. The method is applied to data sets of R-R intervals and to synthetic point process data extracted from the Lorenz time series. The results demonstrate that TPV complements the traditional analysis and can be applied more generally, including Poincaré plots with multiple clusters, and more consistently than the conventional measures and can address questions regarding potential structure underlying the variability of a data set. 相似文献
997.
998.
999.
Fatemi Naieni F Ebrahimi B Vakilian HR Shahmoradi Z 《Biological trace element research》2012,146(1):30-34
Premature graying of hair with unclear etiology, which is known as premature canities, is a common cause of referrals to the
dermatologists. We assessed the relationship between serum iron, copper, and zinc concentrations with premature canities.
This study was conducted on patients under 20 years old suffering from premature canities, having a minimum of ten gray hair
fibers, and referring to university hospitals of Isfahan (Iran). The results were compared with age–sex-matched controls.
Demographic data and disease characteristics were recorded for two groups. We studied serum iron, copper, and zinc concentrations
of 66 patients and 66 controls using atomic absorption and Ferrozine methods. The mean age of studied cases was 17.8 ± 2.0 years,
and the mean age of the onset of canities was 15.5 ± 3.2 years with no significant difference between males and females (P > 0.05). Serum copper concentration was significantly lower in patients compared with controls (90.7 ± 37.4 vs. 105.3 ± 50.2 μg/dL,
P = 0.048), but serum iron concentration was significantly lower in controls compared to patients (88.8 ± 39.5 vs. 108.3 ± 48.4 μg/dL,
P = 0.008). Also, there was no significant difference between patients and controls in serum zinc concentration (114.8 ± 67.8
vs. 108.2 ± 49.9 μg/dL, P = 0.285). According to these results, among copper, zinc, and iron, a low serum copper concentration may play a role in premature
graying of hairs in our society. Further studies are needed to find the underlying mechanism of this relationship. 相似文献
1000.
Kojouri GA Sadeghian S Mohebbi A Mokhber Dezfouli MR 《Biological trace element research》2012,146(2):160-166
The present study was designed to compare the effects of nano-selenium and of sodium selenite on the chemotactic and respiratory
burst activities of neutrophils in sheep. Fifteen sheep were randomly divided into three groups. Groups 1 and 2 received selenium
nanoparticles (1 mg/kg) or sodium selenite (1 mg/kg) orally, respectively, for ten consecutive days, and the third group was
considered as the control. To determine the chemotactic and respiratory burst activities of the neutrophils, the leading front
assay and the NBT test were used on heparinized blood samples that were collected at different intervals (days 0, 10th, 20th,
and 30th). The results obtained showed that the chemotactic activities in groups 1 and 2 increased significantly on the 10th,
20th, and 30th day, compared to day 0, and on the 20th day in comparison with the 10th day, while in group 2, there was a
significant decrease on the 30th day compared to the 20th day. The chemotactic activities in group 1 were significantly higher
than in group 2 on the 10th day and in the control group on the 10th, 20th, and 30th day, but the chemotactic activities in
group 2 were significantly higher than those in the control group only on the 20th day. On the 30th day into the experiment,
the respiratory bursts in groups 1 and 2 were significantly stronger in comparison with those at day 0. Overall, nano-selenium
increased the chemotactic and respiratory burst activities more significantly than sodium selenite, which is suggestive of
a stronger stimulatory effect of the Se nanoparticles on intracellular activities. 相似文献