AIM: To develop a pharmacodynamic model of portal hypertension from chronic hepatitis.
METHODS: Pathological changes and collagen depositions were analyzed using morphometry to confirm CCl4-induced chronic hepatitis. At d0, d28, d56 and d84 of the process, the portal perfused velocities (μL/min) in isolated rat livers were exactly controlled with a quantified pump. The pressure (mmHg) was monitored with a Physiological System. The geometric concentrations of phenylephrine or acetylcholine were added to a fixed volume (300 mL) of the circulating perfusate. The equation, the median effective concentration and its 95% confidence intervals of phenylephrine or acetylcholine were regressed with Prism-4 software in non-linear fit and various slopes. In the isolated perfused rat livers with chronic hepatitis, both median effective concentrations were defined as the pharmacodynamic model of portal hypertension.
RESULTS: At d0, d28, d56 and d84, the equations of portal pressure potency from the concentrations of phenylephrine used to constrict the portal vein in isolated perfused rat livers were Y = 0.1732 + 0.3970/[1 + 10(-4.3061-0.4407 X)], Y = -0.004934 + 0.12113/[1 + 10(-3.1247-0.3262 X)], Y = 0.0104 + 0.2643/[1 + 10(-8.8462-0.9579 X)], and Y = 0.01603 + 0.12107/[1 + 10(-5.1134-0.563 X)]; the median effective concentrations were 1.69 × 10-10 mol/L, 2.64 × 10-10 mol/L, 5.82 × 10-10 mol/L, and 8.24 × 10-10 mol/L, respectively. The equations from the concentrations of acetylcholine used to relax the portal vein were Y = -0.4548 + 0.3274/[1 + 10(6.1538 + 0.5554 X)], Y = -0.05391 + 0.06424/[1 + 10(3.8541 + 0.3469 X)], Y = -0.2733 + 0.22978/[1 + 10(3.0472 + 0.3008 X)], and Y = -0.0559 + 0.053178/[1 + 10(5.6336 + 0.5883 X)]; the median effective concentrations were 8.40 × 10-10 mol/L, 7.73 × 10-12 mol/L, 5.98 × 10-11 mol/L, and 2.66 × 10-10 mol/L, respectively.
CONCLUSION: A pharmacodynamic model of portal hypertension in isolated perfused rat livers with chronic hepatitis was defined as the median effective concentrations of phenylephrine and acetylcholine.
Chronic hepatitis; Isolated portal perfused rat liver; Pharmacodynamic model; Portal hypertension
Dissemination of antibiotic resistant clones is recognized as an important factor in the emergence and prevalence of resistance in pneumococcus. This study was undertaken to survey the antimicrobial susceptibility and serotypes distribution of pneumococci and to explore the circulating clones in hospitalized children in Suzhou, China.
The pneumococci were isolated from the nasopharyngeal aspirates of children less than 5 years of age admitted to Soochow-University-Affiliated-Children's-Hospital with respiratory infections. The capsular serotypes were identified by multiplex polymerase chain reaction (PCR). Antimicrobial susceptibility was tested by E-test. The presence of ermB, mefA/E genes were detected by PCR and the genotypes were explored by Multilocus sequence typing (MLST).
From July 2012 to July 2013, a total of 175 pneumococcal isolates were collected and all strains were resistant to erythromycin and clindamycin, about 39.4% strains were non-susceptible to penicillin G. Overall, 174 (99.4%) isolates were resistant to ≥3 types of antibiotics. Serotypes 19F (28.1%), 6B (19.7%), 19A (18.0%), and 23F (17.4%) were the most common serotypes in all identified strains. The serotypes coverage of PCV7 and PCV13 were 71.9% and 89.9%, respectively. Four international antibiotic-resistant clones, including Taiwan19F-14 (n = 79), Spain23F-1(n = 25), Taiwan23F-15(n = 7) and Spain6B-2(n = 7), were identified. The Taiwan19F-14 clones have a higher non-susceptibility rate in β-lactams than other clones and non-clone isolates (p<0.001). In addition, 98.7% Taiwan19F-14 clones were positive of both ermB and mefA/E genes, compare to 33.3% in other clones and non-clone strains.
The spread of international antibiotic-resistant clones, especially Taiwan19F-14 clones, played a predominant role in the dissemination of antimicrobial resistant isolates in Suzhou, China. Considering the high prevalence of PCV7 serotypes and serotype 19A, the introduction of PCV13 may be a promising preventive strategy to control the increasing trend of clonal spread in China.
Alterations in oscillatory brain activity are strongly correlated with cognitive performance in various physiological rhythms, especially the theta and gamma rhythms. In this study, we investigated the coupling relationship of neural activities between thalamus and medial prefrontal cortex (mPFC) by measuring the phase interactions between theta and gamma oscillations in a depression model of rats. The phase synchronization analysis showed that the phase locking at theta rhythm was weakened in depression. Furthermore, theta-gamma phase locking at n:m (1:6) ratio was found between thalamus and mPFC, while it was diminished in depression state. In addition, the analysis of coupling direction based on phase dynamics showed that the unidirectional influence from thalamus to mPFC was diminished in depression state only in theta rhythm, while it was partly recovered after the memantine treatment in a depression model of rats. The results suggest that the effects of depression on cognitive deficits are modulated via profound alterations in phase information transformation of theta rhythm and theta-gamma phase coupling.
Neural phase–phase coupling; Cognitive deficit; Local field potential; Theta rhythm; Gamma rhythm; Depression
Discovery of new drugs for the treatment of AIDS typically possessing unique structures associated with novel mechanisms of action has been of great importance due to the quick drug-resistant mutations of HIV-1 strains. The work presented in this report describes a novel class of DNA duplex-based HIV-1 fusion inhibitors. Hydrophobic groups were introduced into a DNA duplex skeleton either at one end, at both ends, or in the middle. These modified DNA duplexes inhibited fusion between HIV-1 and human cell membranes at micro- or submicromolar concentrations. Respective inhibitors adopted an aptamer pattern instead of a base-pairing interaction pattern. Structure-activity relationship studies of the respective DNA duplexes showed that the rigid and negatively charged DNA skeletons, in addition to the presence of hydrophobic groups, were crucial to the anti-HIV-1 activity of these compounds. A fluorescent resonance energy transfer (FRET)-based inhibitory assay showed that these duplex inhibitors interacted with the primary pocket in the gp41 N-terminal heptad repeat (NHR) instead of interacting with the lipid bilayers.
The core domains of social anxiety disorder (SAD), generalized anxiety disorder (GAD), panic disorder (PD) with and without agoraphobia (GA), and specific phobia (SP) are cognitive and physical symptoms that are related to the experience of fear and anxiety. It remains unclear whether these highly comorbid conditions that constitute the anxiety disorder subgroups of the Diagnostic and Statistical Manual for Mental Disorders – Fifth Edition (DSM-5) represent distinct disorders or alternative presentations of a single underlying pathology.
A systematic search of voxel-based morphometry (VBM) studies of SAD, GAD, PD, GA, and SP was performed with an effect-size signed differential mapping (ES-SDM) meta-analysis to estimate the clusters of significant gray matter differences between patients and controls.
Twenty-four studies were eligible for inclusion in the meta-analysis. Reductions in the right anterior cingulate gyrus and the left inferior frontal gyrus gray matter volumes (GMVs) were noted in patients with anxiety disorders when potential confounders, such as comorbid major depressive disorder (MDD), age, and antidepressant use were controlled for. We also demonstrated increased GMVs in the right dorsolateral prefrontal cortex (DLPFC) in comorbid depression-anxiety (CDA), drug-naïve and adult patients. Furthermore, we identified a reduced left middle temporal gyrus and right precentral gyrus in anxiety patients without comorbid MDD.
Our findings indicate that a reduced volume of the right ventral anterior cingulate gyrus and left inferior frontal gyrus is common in anxiety disorders and is independent of comorbid depression, medication use, and age. This generic effect supports the notion that the four types of anxiety disorders have a clear degree of overlap that may reflect shared etiological mechanisms. The results are consistent with neuroanatomical DLPFC models of physiological responses, such as worry and fear, and the importance of the ventral anterior cingulate (ACC)/medial prefrontal cortex (mPFC) in mediating anxiety symptoms.
To assess erectile function in middle-aged and older men with asexuality status and further analyze their specific reasons for this condition.
Subjects and Methods
Men who had regular sexual intercourse attempts (sex frequency≥1 time per month) were classified into mild erectile dysfunction (ED), moderate to severe ED and non-ED according to International Index of Erectile Function-5, and men having no sexual intercourse attempts for at least 6 months were defined as having an asexuality status. The risk factors associated with ED were collected in a sample of 1,531 Chinese men aged 40 to 80 years, and the self-report reasons for asexuality were recorded in asexual cohort individually. Comparative analyses and multivariate regression models were conducted among these groups.
The prevalence rates of ED and asexuality status were 49.9% and 37.2%. The asexuality status group had higher risk factors than the moderate to severe ED group in terms of old age (age≥65, adjusted odds ratio (OR) 17.69 versus (Vs.) 7.19), diabetes (crude OR: 2.40 Vs. 2.36) and hypertension (crude OR: 1.78 Vs. 1.72). The specific reasons for the asexuality status were “erectile difficulty” (52.9%), “do not care about sexuality” (53.5%)”, “no longer necessary to have sexuality at this age” (47.7%), “severe stress” (44.4%), “severe fatigue” (26.3%) and “masturbation” (26.9%).
Men with an asexual status suffer from higher risk factors for ED than men with moderate to severe ED. The majority of this asexual status could be attributed to a full ED, although the reasons for this transient asexuality also involved sexual attitudes and interests, sexual partners and masturbation.
To develop spray dried mucoadhesive and pH-sensitive microspheres (MS) based on polymethacrylate salt intended for vaginal delivery of tenofovir (a model HIV microbicide) and assess their critical biological responses.
The formulation variables and process parameters are screened and optimized using a 24-1 fractional factorial design. The MS are characterized for size, zeta potential, yield, encapsulation efficiency, Carr’s index, drug loading, in vitro release, cytotoxicity, inflammatory responses and mucoadhesion.
The optimal MS formulation has an average size of 4.73 µm, Zeta potential of −26.3 mV, 68.9% yield, encapsulation efficiency of 88.7%, Carr’s index of 28.3 and drug loading of 2% (w/w). The MS formulation can release 90% of its payload in the presence of simulated human semen. At a concentration of 1 mg/ml, the MS are noncytotoxic to vaginal endocervical/epithelial cells and Lactobacillus crispatus when compared to control media. There is also no statistically significant level of inflammatory cytokine (IL1-α, IL-1β, IL-6, IL-8, and IP-10) release triggered by MS. The mucoadhesive property of MS formulation is 2-fold higher than that of 1% HEC gel formulation.
These data suggest the promise of using such MS as an alternative controlled microbicide delivery template by intravaginal route for HIV prevention.
pH-sensitive; mucoadhesive; tenofovir; spray drying; HIV/AIDS microbicide
The first case of human infection with avian influenza A (H7N9) virus was identified in March, 2013 and the new H7N9 virus infected 134 patients and killed 45 people in China as of September 30, 2013. Family clusters with confirmed or suspected the new H7N9 virus infection were previously reported, but the family cluster of H7N9 virus infection in Shandong Province was first reported.
A 36-year-old man was admitted to Zaozhuang City Hospital with progressive respiratory distress and suspicion of impending acute respiratory distress syndrome on April 21. The chest radiography revealed bilateral ground-glass opacities and pulmonary lesions. The second case, the first case’s 4 year old son, was admitted to the same hospital on April 28 with fever and multiple patchy shadows in the bilateral lungs. Both of the two cases were confirmed to infect with H7N9 virus by the results of real-time reverse transcriptase-polymerase-chain reaction (rRT-PCR), virus isolation and serum antibody titer. At the same time, one environment samples was detected positive for H7N9 virus in the living poultry market in Zaozhuang. The homologous analysis of the full genome sequence indicated that both viruses from the patients were almost genetically identical. The field epidemiology investigation showed that the two cases had no recognized exposure to poultry, but had the exposure to the environment. The second case had substantial unprotected close exposure to his ill father and developed symptoms seven days after his last contact with his father. After surgery, the index case and his son were discharged on May 16 and May 6, respectively. 11 close contacts of both patients were identified and tested negative both the throat swabs and the serum antibody.
The infection of the index case probably resulted from contact with environmentally contaminated material. For the son, the probable infection source was from the index case during unprotected exposure, but the possibility from the environment or other sources could not be completely ruled out.
Avian Influenza A (H7N9) virus; Epidemiology; Infectious source
The ability of the following four organic amendments to ameliorate saline soil in coastal northern China was investigated from April 2010 to October 2012 in a field experiment: green waste compost (GWC), sedge peat (SP), furfural residue (FR), and a mixture of GWC, SP and FR (1∶1∶1 by volume) (GSF). Compared to a non-amended control (CK), the amendments, which were applied at 4.5 kg organic matter m−3, dramatically promoted plant growth; improved soil structure; increased the cation exchange capacity (CEC), organic carbon, and available nutrients; and reduced the salt content, electrical conductivity (EC), and exchangeable sodium percentage (ESP). At the end of the experiment in soil amended with GSF, bulk density, EC, and ESP had decreased by 11, 87, and 71%, respectively, and total porosity and organic carbon had increased by 25 and 96% respectively, relative to the CK. The GSF treatment resulted in a significantly lower Na++K+ content than the other treatments. CEC and the contents of available N, P, and K were significantly higher in the GSF-treated soil than in the CK and were the highest in all treatments. The FR treatment resulted in the lowest pH value and Ca2+ concentration, which decreased by 8% and 39%, respectively, relative to the CK. Overall, the results indicate that a combination of green waste compost, sedge peat and furfural residue (GSF treatment) has substantial potential for ameliorating saline soils in the coastal areas of northern China, and it works better than each amendment alone. Utilization of GWC and FR can be an alternative organic amendment to substitute the nonrenewable SP in saline soil amelioration.
Cancer cells remodel their metabolic programmes to meet the requirements of rapid proliferation. Glutaminase (GLS1) is a mitochondrial enzyme that converts glutamine to glutamate. Our aim was to investigate, for the first time, GLS1 protein expression in colorectal cancer and to evaluate its clinical significance. Immunohistochemical analysis was performed on tissue microarrays containing pairs of cancer and adjacent normal tissues from colorectal cancer patients (n=257). The expression of GLS1 protein in normal colonic tissues and colorectal cancer was measured by western blotting. Proliferation and cell death were evaluated in colorectal cancer cell lines after GLS1 inhibitor treatment. Compared with normal tissues (18.15%), we observed that the expression of GLS1 increased significantly in colorectal cancer (80.24%; P<0.0001) by immunohistochemical analysis, and the elevation of GLS1 protein expression levels in fresh colorectal cancer samples versus normal colonic tissues were also observed by western blotting. Furthermore, GLS1 expression levels were significantly associated with deeper tumour infiltration (P=0.0002), and the pathological pattern of tubular adenocarcinoma (p=0.0008). In addition, treatment with the GLS1 inhibitor suppressed proliferation and induced apoptosis in HT29 and SW480 cell lines. These results suggest that the expression of GLS1 is upregulated and correlates with clinicopathological factors in colorectal cancer. GLS1 exhibits functional importance in colon cancer tumorigenesis. Moreover, GLS1 may serve as a target for colorectal cancer therapy.
Colorectal cancer; glutaminase; tumorigenesis
Public health surveillance systems provide valuable data for reliable predication of future epidemic events. This paper describes a study that used nine types of infectious disease data collected through a national public health surveillance system in mainland China to evaluate and compare the performances of four time series methods, namely, two decomposition methods (regression and exponential smoothing), autoregressive integrated moving average (ARIMA) and support vector machine (SVM). The data obtained from 2005 to 2011 and in 2012 were used as modeling and forecasting samples, respectively. The performances were evaluated based on three metrics: mean absolute error (MAE), mean absolute percentage error (MAPE), and mean square error (MSE). The accuracy of the statistical models in forecasting future epidemic disease proved their effectiveness in epidemiological surveillance. Although the comparisons found that no single method is completely superior to the others, the present study indeed highlighted that the SVMs outperforms the ARIMA model and decomposition methods in most cases.
MRI using receiver arrays with many coil elements can provide high signal-to-noise ratio and increase parallel imaging acceleration. At the same time, the growing number of elements results in larger datasets and more computation in the reconstruction. This is of particular concern in 3D acquisitions and in iterative reconstructions. Coil compression algorithms are effective in mitigating this problem by compressing data from many channels into fewer virtual coils. In Cartesian sampling there often are fully sampled k-space dimensions. In this work, a new coil compression technique for Cartesian sampling is presented that exploits the spatially varying coil sensitivities in these non-subsampled dimensions for better compression and computation reduction. Instead of directly compressing in k-space, coil compression is performed separately for each spatial location along the fully-sampled directions, followed by an additional alignment process that guarantees the smoothness of the virtual coil sensitivities. This important step provides compatibility with autocalibrating parallel imaging techniques. Its performance is not susceptible to artifacts caused by a tight imaging fieldof-view. High quality compression of in-vivo 3D data from a 32 channel pediatric coil into 6 virtual coils is demonstrated.
Coil Compression; Parallel Imaging; Compressed Sensing
The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), either alone or in combination with other anti-cancer agents, has been considered as a new strategy for anti-cancer therapy. In this study, we demonstrated that evodiamine, a quinolone alkaloid isolated from the fruit of Evodia fructus, induced apoptosis and enhanced TRAIL-induced apoptosis in human bladder cancer cells. To elucidate the underlying mechanism, we found that evodiamine significantly reduced the protein levels of Mcl-1 in 253J and T24 bladder cancer cells, and overexpression of this molecule attenuated the apoptosis induced by evodiamine alone, or in combination with TRAIL. Further experiments revealed that evodiamine did not affect the mRNA level, proteasomal degradation and protein stability of Mcl-1. On the other hand, evodiamine inhibited the mTOR/S6K1 pathway, which usually regulates protein translation; moreover, knockdown of S6K1 with small interfering RNA (siRNA) effectively reduced Mcl-1 levels, indicating evodiamine downregulates c-FLIP through inhibition of mTOR/S6K1 pathway. Taken together, our results indicate that evodiamine induces apoptosis and enhances TRAIL-induced apoptosis possibly through mTOR/S6K1-mediated downregulation of Mcl-1; furthermore, these findings provide a rationale for the combined application of evodiamine with TRAIL in the treatment of bladder cancer.
evodiamine; TRAIL; Mcl-1; mTOR; S6K1; bladder cancer
KCa3.1 channel participates in many important cellular functions. This study planned to investigate the potential involvement of KCa3.1 channel in premature senescence, myofibroblast phenotype transition and proliferation of mesangial cells.
Methods & Materials
Rat mesangial cells were cultured together with TGF-β1 (2 ng/ml) and TGF-β1 (2 ng/ml) + TRAM-34 (16 nM) separately for specified times from 0 min to 60 min. The cells without treatment served as controls. The location of KCa3.1 channels in mesangial cells was determined with Confocal laser microscope, the cell cycle of mesangial cells was assessed with flow cytometry, the protein and mRNA expression of KCa3.1, α-smooth muscle actin (α-SMA) and fibroblast-specific protein-1 (FSP-1) were detected with Western blot and RT-PCR. One-way analysis of variance (ANOVA) and Student-Newman-Keuls-q test (SNK-q) were used to do statistical analysis. Statistical significance was considered at P<0.05.
Kca3.1 channels were located in the cell membranes and/or in the cytoplasm of mesangial cells. The percentage of cells in G0-G1 phase and the expression of Kca3.1, α-SMA and FSP-1 were elevated under the induction of TGF-β1 when compared to the control and decreased under the induction of TGF-β1+TRAM-34 when compared to the TGF-β1 induced (P<0.05 or P<0.01).
Targeted disruption of KCa3.1 inhibits TGF-β1-induced premature aging, myofibroblast-like phenotype transdifferentiation and proliferation of mesangial cells.
Inferring of parentage in natural populations is important in understanding the mating systems of a species, which have great effects on its genetic structure and evolution. Muricidae, a large group (approximately 1,600 species) of marine gastropods, are poorly investigated in patterns of multiple paternity and sperm competition based on molecular techniques. The veined Rapa whelk, Rapana venosa, a commercially important muricid species with internal fertilization, is an ideal species to study the occurrence and frequency of multiple paternity and to facilitate understanding of their reproductive strategies.
We developed five highly polymorphic microsatellites in R. venosa and applied them to identify multiple paternity in 19 broods (1381 embryos) collected from Dandong, China. Multiple paternity was detected in 17 (89.5%) of 19 broods. The number of sires per brood ranged from 1 to 7 (4.3 on average). Of the 17 multiply sired broods, 16 (94.1%) were significantly skewed from equal paternal contributions, and had a dominant sire which was also dominant in each assayed capsule.
Our results indicate that a high level of multiple paternity occurs in the wild population of R. venosa. Similar patterns of multiple paternity in the 2–6 assayed capsules from each brood imply that fertilization events within the body of a female occur mostly (but not entirely) as random draws from a “well-but-not-perfectly blended sperm pool” of her several mates. Strongly skewed distributions of fertilization success among sires also suggest that sperm competition and/or cryptic female choice might be important for post-copulatory paternity biasing in this species.
In epilepsy it has been challenging to detect early changes in brain activity that occurs prior to seizure onset and to map their origin and evolution for possible intervention. Here we demonstrate using a rat model of generalized epilepsy that diffuse optical tomography (DOT) provides a unique functional neuroimaging modality for noninvasively and continuously tracking such brain activities with high spatiotemporal resolution. We detected early hemodynamic responses with heterogeneous patterns, along with intracranial electroencephalogram gamma power changes, several minutes preceding the electroencephalographic seizure onset, supporting the presence of a “pre-seizure” state. We also observed the decoupling between local hemodynamic and neural activities. We found widespread hemodynamic changes evolving from local regions of the bilateral cortex and thalamus to the entire brain, indicating that the onset of generalized seizures may originate locally rather than diffusely. Together, these findings suggest DOT represents a powerful tool for mapping early seizure onset and propagation pathways.
Lichen is a classic mutualistic organism and the lichenization is one of the fungal symbioses. The lichen-forming fungus Endocarpon pusillum is living in symbiosis with the green alga Diplosphaera chodatii Bialsuknia as a lichen in the arid regions.
454 and Illumina technologies were used to sequence the genome of E. pusillum. A total of 9,285 genes were annotated in the 37.5 Mb genome of E. pusillum. Analyses of the genes provided direct molecular evidence for certain natural characteristics, such as homothallic reproduction and drought-tolerance. Comparative genomics analysis indicated that the expansion and contraction of some protein families in the E. pusillum genome reflect the specific relationship with its photosynthetic partner (D. chodatii). Co-culture experiments using the lichen-forming fungus E. pusillum and its algal partner allowed the functional identification of genes involved in the nitrogen and carbon transfer between both symbionts, and three lectins without signal peptide domains were found to be essential for the symbiotic recognition in the lichen; interestingly, the ratio of the biomass of both lichen-forming fungus and its photosynthetic partner and their contact time were found to be important for the interaction between these two symbionts.
The present study lays a genomic analysis of the lichen-forming fungus E. pusillum for demonstrating its general biological features and the traits of the interaction between this fungus and its photosynthetic partner D. chodatii, and will provide research basis for investigating the nature of its drought resistance and symbiosis.
Mycobiont; Phycobiont; Lichenization; Symbiosis; Symbiosis-related gene; Photosynthetic products
The purpose of this study is to investigate the effects of a high-fat diet from perilla oil on serum lipids, hepatic lipid metabolism and insulin sensitivity.
Male Sprague–Dawley (SD) rats were fed either a control (CT) diet or a diet high in perilla oil (HP). After 16 weeks of feeding, the serum lipids were measured, and the gene expressions involved in hepatic fatty acid oxidation and synthesis were determined. In addition, hepatic fat deposition was detected, and insulin sensitivity was evaluated by means of euglycemic-hyperinsulinemic clamp.
Compared with the rats in the CT group, the HP-feeding significantly decreased the levels of triglyceride (TG), total cholesterol (TCH) and HDL-cholesterol (HDL-c). HP-feeding did not change the levels of LDL-cholesterol (LDL-c), free fatty acid (FFA), intrahepatic lipids or body weight. Moreover, the HP-feeding dramatically increased the mRNA expressions of fatty acid oxidation markers (PPAR-alpha, CPT1A) and fatty acid synthesis markers (SREBP-1, FASN and ACC) in the liver. The HP-feeding induced increased protein levels of CPT1A, while reducing the protein levels of FASN and ACC in the liver. However, the glucose infusion rate significantly increased in the HP group compared with the CT group.
Our data show that, in rats, excessive perilla oil intake may significantly lower serum lipids, strengthen hepatic fatty acid oxidation, and inhibit hepatic fatty acid synthesis, but at the same time may also lead to insulin resistance.
Perilla oil; Alpha-linolenic acid; Serum lipid; Fatty acid oxidation; Insulin sensitivity
The responses of litter decomposition to nitrogen (N) and phosphorus (P) additions were examined in an old-growth tropical forest in southern China to test the following hypotheses: (1) N addition would decrease litter decomposition; (2) P addition would increase litter decomposition, and (3) P addition would mitigate the inhibitive effect of N addition. Two kinds of leaf litter, Schima superba Chardn. & Champ. (S.S.) and Castanopsis chinensis Hance (C.C.), were studied using the litterbag technique. Four treatments were conducted at the following levels: control, N-addition (150 kg N ha−1 yr−1), P-addition (150 kg P ha−1 yr−1) and NP-addition (150 kg N ha−1 yr−1 plus 150 kg P ha−1 yr−1). While N addition significantly decreased the decomposition of both litters, P addition significantly inhibited decomposition of C.C., but did not affect the decomposition of S.S. The negative effect of N addition on litter decomposition might be related to the high N-saturation in this old-growth tropical forest; however, the negative effect of P addition might be due to the suppression of “microbial P mining”. Significant interaction between N and P addition was found on litter decomposition, which was reflected by the less negative effect in NP-addition plots than those in N-addition plots. Our results suggest that P addition may also have negative effect on litter decomposition and that P addition would mitigate the negative effect of N deposition on litter decomposition in tropical forests.
Arachidonic (ARA), eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids are the most biologically active polyunsaturated fatty acids, but their biosyntheses in mammals are very limited. The biosynthesis of DHA is the most difficult, because this undergoes the Sprecher pathway–a further elongation step from docosapentaenoic acid (DPA), a Δ6-desaturase acting on a C24 fatty acid substrate followed by a peroxisomal chain shortening step. This paper reports the successful heterologous expression of two non-mammalian genes (with modification of codon usage), coding for Euglena gracilis Δ4-desaturase and Siganus canaliculatus Δ4-desaturase respectively, in mammalian cells (HEK293 cell line). Both of the Δ4-desaturases can efficiently function, directly converting DPA into DHA. Moreover, the cooperation of the E. gracilis Δ4-desaturase with C. elegans Δ15-desaturase (able to convert a number of n-6 PUFAs to their corresponding n-3 PUFAs) in transgenic HEK293 cells made a more desirable fatty acid composition – a drastically reduced n-6/n-3 PUFAs ratio and a high level of DHA as well as EPA and ARA. Our findings provide a basis for potential applications of the gene constructs for expression of Δ15/Δ4-desaturases in transgenic livestock to produce such a fatty acid profile in the related products, which certainly will bring benefit to human health.
Type 2 diabetes mellitus (T2DM) is a major public health problem in China. Diagnostic markers are urgently needed to identify individuals at risk of developing T2DM and encourage them to adapt to a healthier life style. Circulating miRNAs present important sources of noninvasive biomarkers of various diseases. Recently, a novel plasma microRNA signature was identified in T2DM. Here, we evaluated the T2DM-related miRNA signature in plasma of three study groups: normal (fasting glucose (FG), 4.8–5.2 mmol/L), T2DM-susceptible (FG, 6.1–6.9 mmol/L), and T2DM individuals (FG, ≥7.0 mmol/L) and tested the feasibility of using circulating miRNAs to identify individuals at risk of developing T2DM. Among the 5 miRNAs included in the signature, miR-29b and miR-28-3p are not detectable. miR-15a and miR-223 have comparable expression levels among three groups. Notably, miR-126 is the only miRNA that showed significantly reduced expression in susceptible individuals and T2DM patients compared to normal individuals, suggesting that miR-126 in circulation may serve as a potential biomarker for early identification of susceptible individuals to T2DM.
It has been reported that sodium fluoride (NaF) suppresses the proliferation and induces apoptosis of chondrocytes. However, the cellular and molecular mechanisms of the effect have not been elucidated. Therefore, the aim of this study was to evaluate the mechanisms of the effects of NaF on primary cultured rat chondrocytes in vitro. Chondrocytes were treated with NaF at concentrations of 0, 1.5, 2.0, 2.5, 3.0, 3.5 and 4.0 mM. Cell viability decreased and the rate of apoptotic cells increased significantly with the gradient concentration of NaF in a time- and dose-dependent manner. Electron microscopy revealed cytoplasmic, organelle and nuclear alterations in the ultrastructure of chondrocytes exposed to various NaF concentrations. The cell cycle distribution was analyzed by flow cytometry, and the results indicated that NaF induced G2 cell cycle arrest. Western blotting was used to detect the apoptotic pathways. Downregulation of the Bcl-2 protein and upregulation of Bax, cleaved caspase-9, −12 and −3 proteins suggested that NaF was capable of inducing apoptosis through the mitochondrial and endoplasmic reticulum pathways. The results also showed that the levels of hypoxia-inducible factor 1α (HIF-1α), sex determining region Y box gene 9 (Sox9) and the collagen II (Col II) protein of the NaF groups were lower compared to those of the control groups. Thus, NaF may induce apoptosis through the downregulation of HIF-1α and disrupt the synthesis of extracellular matrix (ECM) through the downregulation of HIF-1α via the Sox9 pathway in primary cultured rat chondrocytes.
sodium fluoride; chondrocyte; hypoxia-inducible factor 1α; sex determining region Y box gene 9; collagen II; apoptosis