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Find video protocols related to scientific articles indexed in Pubmed.
Effect of YOYO-1 on the mechanical properties of DNA.
Soft Matter
PUBLISHED: 11-04-2014
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YOYO-1 is a green fluorescent dye which is widely used to image single DNA molecules in solution for biophysical studies. However, the question of whether the intercalation of YOYO-1 affects the mechanical properties of DNA is still not clearly answered. Investigators have put forth contradicting data on the changes in persistence length of DNA. Here, we use atomic force microscopy to systematically study the changes in the mechanical properties of DNA due to the intercalation of YOYO-1. We first measured the persistence length, contour length and the bending angle distribution of the DNA-YOYO-1 complex. We find that the persistence length of DNA remains unaffected with the intercalation of YOYO-1. However the contour length increases linearly with about 38% increase at full saturation of 1 YOYO-1 per 4 base pairs of DNA. Next we measured the change in topology of relaxed closed circular DNA after the intercalation of YOYO-1. We find that YOYO-1 introduces supercoiling in closed circular DNA. Our observations indicate that the intercalation of YOYO-1 results in the underwinding of DNA duplex, but does not significantly change the persistence length.
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Novel Avian-Origin Influenza A (H7N9) in Critically Ill Patients in China.
Crit. Care Med.
PUBLISHED: 11-04-2014
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In March 2013, human infection with a novel avian-origin reassortment influenza A (H7N9) virus was identified in China. A total of 26 cases were confirmed and treated in Jiangsu. All the patients had findings consistent with pneumonia and were admitted to an ICU, which pose a threat to human health. We aimed to provide the clinical features, treatment, and prognosis of the critically ill patients with H7N9 viral infection.
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Interconversion between Three Overstretched DNA Structures.
J. Am. Chem. Soc.
PUBLISHED: 11-04-2014
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Double-stranded DNA can exist in multiple structures, including three recently identified overstretched structures (peeled ssDNA, DNA bubble, and S-DNA) for torsion-unconstrained DNA under large tension. Here, we report systematic studies of interconversion between these overstretched DNA structures induced by changing NaCl concentration at constant force. At forces above 70 pN where DNA exists in one of the overstretched states, direct interconversions between S-DNA and DNA bubble for the end-closed DNA construct, as well as interconversions between S-DNA and peeled ssDNA for the end-opened DNA construct, were observed to involve stepwise extension changes. Interestingly, compared to other conversions, the conversion from peeled ssDNA to S-DNA has ultraslow kinetics, which can be explained by formation of secondary hairpin structures on a relaxed strand of peeled ssDNA. Our findings provide important insights into the structures of torsion-unconstrained DNA under large force.
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Mesenchymal Stem Cells Enhance Angiogenesis and Follicle Survival in Human Cryopreserved Ovarian Cortex Transplantation.
Cell Transplant
PUBLISHED: 10-30-2014
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Transplantation of cryopreserved ovarian tissue is a novel technique to restore endocrine function and fertility especially for cancer patients. However, the main obstacle of the technique is massive follicle loss as a result of ischemia in the process of transplantation. Mesenchymal stem cells (MSCs) have been acknowledged to play an important role in supporting angiogenesis and stabilizing long-lasting blood vessels network through release of angiogenic factors and differentiation into pericytes and endothelial cells. This study is aimed to investigate whether MSCs could be applied to overcome the above obstacle to support the ovarian tissue survival in the transplantation. Here we show that human MSCs could enhance the expression level of VEGF, FGF2 and especially the level of angiogenin, significantly stimulate neovascularization and increase blood perfusion of the grafts in the cryopreserved ovarian tissue transplantation. Further studies reveal that MSCs could notably reduce the apoptotic rates of primordial follicles and decrease follicle loss in the grafted ovarian tissues. In summary, our findings demonstrate a previously unrecognized function of MSCs in improving human ovarian tissue transplantation and provide a useful strategy to optimize fertility preservation and restoration.
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The complete mitochondrial genome of the flesh fly, Parasarcophaga portschinskyi (Diptera: Sarcophagidae).
Mitochondrial DNA
PUBLISHED: 10-17-2014
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Abstract The complete mitochondrial genome of Parasarcophaga portschinskyi (Diptera: Sarcophagidae), a forensically important entomology was sequenced for the first time. The 14,929?bp circular genome contains the 37 genes found in a typical Metazoan genome: 13 protein-coding genes, 2 ribosomal RNA genes and 22 transfer RNA genes. It also contains one non-coding A?+?T-rich region. All the protein initiation codons are ATN, except for cox1 that begins with TCG. Each of the base composition on heavy strand was as follows A: 38.94%, G: 9.69%, C: 14.13%, T: 37.24% and the A?+?T content 76.18%. The mitochondrial genome of Parasarcophaga portschinskyi presented will be valuable for resolving phylogenetic relationships within the family Sarcophagidae and order Diptera, and could be used to identify favorable genetic markers for species identifications for forensic purposes.
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International Association of Diabetes and Pregnancy Study Group criteria is suitable for gestational diabetes mellitus diagnosis: further evidence from China.
Chin. Med. J.
PUBLISHED: 10-16-2014
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The International Association of Diabetes and Pregnancy Study Group (IADPSG) recommended new diagnostic criteria for gestational diabetes mellitus (GDM) after extensive analyses of the Hyperglycemia and Adverse Pregnancy Outcomes (HAPO) study. Unfortunately, there was no data from mainland of China in this study. We evaluated the feasibility of IADPSG criteria for GDM diagnosis in China.
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Mechanical force antagonizes the inhibitory effects of RecX on RecA filament formation in Mycobacterium tuberculosis.
Nucleic Acids Res.
PUBLISHED: 10-07-2014
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Efficient bacterial recombinational DNA repair involves rapid cycles of RecA filament assembly and disassembly. The RecX protein plays a crucial inhibitory role in RecA filament formation and stability. As the broken ends of DNA are tethered during homologous search, RecA filaments assembled at the ends are likely subject to force. In this work, we investigated the interplay between RecX and force on RecA filament formation and stability. Using magnetic tweezers, at single molecular level, we found that Mycobacterium tuberculosis (Mt) RecX could catalyze stepwise de-polymerization of preformed MtRecA filament in the presence of ATP hydrolysis at low forces (<7 pN). However, applying larger forces antagonized the inhibitory effects of MtRecX, and a partially de-polymerized MtRecA filament could re-polymerize in the presence of MtRecX, which cannot be explained by previous models. Theoretical analysis of force-dependent conformational free energies of naked ssDNA and RecA nucleoprotein filament suggests that mechanical force stabilizes RecA filament, which provides a possible mechanism for the observation. As the antagonizing effect of force on the inhibitory function of RecX takes place in a physiological range; these findings broadly suggest a potential mechanosensitive regulation during homologous recombination.
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The complete mitochondria genome of Chrysomya pinguis (Diptera: Calliphoridae).
Mitochondrial DNA
PUBLISHED: 09-19-2014
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Abstract Chrysomya pinguis (Ch. pinguis) belongs to blowfly species of great medical and forensic importance. In this study, we report the complete mitochondrial genome of the Ch. pinguis for species identification. The 38 genes presented in the 15,838?bp circular genome has been found in a typical Metazoan genome, of which there are 23 transfer RNA genes, 13 protein-coding genes and 2 ribosomal RNA genes. In addition, there is a non-coding A?+?T-rich region between one and another tRNA-Ile. The array of the genes is similar to that discovered in other insects. The overall base compositions of A, G, C and T are 38.72%, 9.86%, 14.07% and 37.35% respectively. This study contributes to the availability of dipteran mitochondrial genomes and provides the first complete mitochondrial genome of Ch. pinguis for entomologists to identify diagnostic regions for species identifications and phylogenetic analysis.
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The complete mitochondria genome of Parasarcophaga similis (Diptera: Sarcophagidae).
Mitochondrial DNA
PUBLISHED: 09-12-2014
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Abstract The complete mitochondrial genome of Parasarcophaga similis collected from China was determined using PCR reactions. The mitogenome was 15,158?bp in length with a total A?+?T content of 76.4%, consisting of 22 transfer RNA genes, 13 protein-coding genes, 2 ribosomal RNA genes and a control region. The gene contents of the mitogenome were identical to those observed in other insects. The overall base compositions of A, G, C and T were 39.54%, 9.43%, 14.20% and 36.83%, respectively. This paper aimed to improve and perfect dipteran mitochondrial genomes and provided the first complete mitochondrial genome of Parasarcophaga similis for entomologists as a potential tool for application of phylogenetic analysis and forensic entomology.
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Role of the nucleus tractus solitarii in the protection of pre-moxibustion on gastric mucosal lesions.
Neural Regen Res
PUBLISHED: 09-11-2014
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Previous studies have shown that somatic sensation by acupuncture and visceral nociceptive stimulation can converge in the nucleus tractus solitarii where neurons integrate signals impacting on the function of organs. To explore the role of the nucleus tractus solitarii in the protective mechanism of pre-moxibustion on gastric mucosa, nucleus tractus solitarii were damaged in rats and pre-moxibustion treatment at the Zusanli (ST36) point followed. The gastric mucosa was then damaged by the anhydrous ethanol lavage method. Morphological observations, enzyme linked immunosorbent assays, and western immunoblot analyses showed that gastric mucosa surface lesion and the infiltration of inflammatory cells were significantly ameliorated after pre-moxibustion treatment. Furthermore, the gastric mucosal damage index and somatostatin level were reduced, and epidermal growth factor content in the gastric mucosa and heat-shock protein-70 expression were increased. These results were reversed by damage to the nucleus tractus solitarii. These findings suggest that moxibustion pretreatment at the Zusanli point is protective against acute gastric mucosa injury, and nucleus tractus solitarii damage inhibits these responses. Therefore, the nucleus tractus solitarii may be an important area for regulating the signal transduction of the protective effect of pre-moxibustion on gastric mucosa.
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The Ap3b1 gene regulates the ocular melanosome biogenesis and tyrosinase distribution differently from the Hps1 gene.
Exp. Eye Res.
PUBLISHED: 08-24-2014
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Hermansky-Pudlak syndrome (HPS) is an autosomal recessive disorder in humans and mice. The pearl (pe) mouse, a mouse model for the human HPS-2, bears a mutation in Ap3b1 gene. Here we investigated the pigmentation in eyes of pearl (pe) mice, and compared it with our previously published data in pale ear (ep) mice. We revealed that the hypopigmentation in eyes of pearl mice was more severe than pale ear mice, especially in the neural crest-derived tissues. However, the total tyrosinase activity in eyes of pearl mice was stronger than pale ear mice, suggesting that the degradation of aberrantly transported tyrosinase in eyes of pearl mice was weaker than that of pale ear mice. Furthermore, the pigmentation in eyes of mice doubly heterozygous for Hps1 and Ap3b1 genes was similar to the wild-type, while the hypopigmentation in iris of double mutant mice was more severe than either single mutant. Besides, we found several previously reported characters in pale ear mice, including macromelanosomes in the neural crest-derived melanocytes and increased accumulation of lipofuscin in the RPE, were absent in pearl mice. Our study indicates that Ap3b1 gene play distinct roles in melanin production and tyrosinase distribution compared with Hps1 gene.
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Genomic organization, transcriptomic analysis, and functional characterization of avian ?- and ?-keratins in diverse feather forms.
Genome Biol Evol
PUBLISHED: 08-24-2014
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Feathers are hallmark avian integument appendages, although they were also present on theropods. They are composed of flexible corneous materials made of ?- and ?-keratins, but their genomic organization and their functional roles in feathers have not been well studied. First, we made an exhaustive search of ?- and ?-keratin genes in the new chicken genome assembly (Galgal4). Then, using transcriptomic analysis, we studied ?- and ?-keratin gene expression patterns in five types of feather epidermis. The expression patterns of ?-keratin genes were different in different feather types, whereas those of ?-keratin genes were less variable. In addition, we obtained extensive ?- and ?-keratin mRNA in situ hybridization data, showing that ?-keratins and ?-keratins are preferentially expressed in different parts of the feather components. Together, our data suggest that feather morphological and structural diversity can largely be attributed to differential combinations of ?- and ?-keratin genes in different intrafeather regions and/or feather types from different body parts. The expression profiles provide new insights into the evolutionary origin and diversification of feathers. Finally, functional analysis using mutant chicken keratin forms based on those found in the human ?-keratin mutation database led to abnormal phenotypes. This demonstrates that the chicken can be a convenient model for studying the molecular biology of human keratin-based diseases.
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Up-regulation of heme oxygenase-1 expression modulates reactive oxygen species level during the cryopreservation of human seminiferous tubules.
Fertil. Steril.
PUBLISHED: 08-20-2014
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To study the effect of freezing techniques and to optimize a method for trace amounts of testicular spermatozoa from biopsed seminiferous tubules. The level of reactive oxygen species (ROS) and the gene expression of heme oxygenase-1 was evaluated.
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An intensity ratio of interlocking loops determines circadian period length.
Nucleic Acids Res.
PUBLISHED: 08-13-2014
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Circadian clocks allow organisms to orchestrate the daily rhythms in physiology and behaviors, and disruption of circadian rhythmicity can profoundly affect fitness. The mammalian circadian oscillator consists of a negative primary feedback loop and is associated with some 'auxiliary' loops. This raises the questions of how these interlocking loops coordinate to regulate the period and maintain its robustness. Here, we focused on the REV-ERB?/Cry1 auxiliary loop, consisting of Rev-Erb?/ROR-binding elements (RORE) mediated Cry1 transcription, coordinates with the negative primary feedback loop to modulate the mammalian circadian period. The silicon simulation revealed an unexpected rule: the intensity ratio of the primary loop to the auxiliary loop is inversely related to the period length, even when post-translational feedback is fixed. Then we measured the mRNA levels from two loops in 10-mutant mice and observed the similar monotonic relationship. Additionally, our simulation and the experimental results in human osteosarcoma cells suggest that a coupling effect between the numerator and denominator of this intensity ratio ensures the robustness of circadian period and, therefore, provides an efficient means of correcting circadian disorders. This ratio rule highlights the contribution of the transcriptional architecture to the period dynamics and might be helpful in the construction of synthetic oscillators.
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Dichloroacetate prevents but not reverses the formation of neointimal lesions in a rat model of severe pulmonary arterial hypertension.
Mol Med Rep
PUBLISHED: 07-30-2014
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The formation of neointimal lesions is one of the characteristic pathological alterations of the pulmonary vasculature in response to sustained pulmonary arterial hypertension (PAH). To date, the effect of dichloroacetate (DCA) on these intimal lesions had remained to be investigated. In the present study, the beneficial impact of DCA on the formation of neointimal lesions was examined in rats treated with monocrotaline following pneumonectomy. The rats were subjected to monocrotaline subcutaneous injection seven days following left pneumonectomy and received DCA by gastric gavage (80 mg/kg/day) for 20 days. At the end of the experiments, hemodynamic measurement was performed prior to the excision of the rats' right lungs for further morphometric and immunoblot analysis. Furthermore, the activity of reactive oxygen species (ROS), superoxide dismutase (SOD) in the lungs was examined by a colorimetric assay. The results revealed that DCA treatment from day 8-28 following pneumonectomy caused a marked reduction in pulmonary arterial pressure and amelioration in right ventricle hypertrophy (mean pulmonary arterial pressure, 24±2.8 vs. 33±5.5 mmHg; right ventricle-to-left ventricle + intra-ventricle septum ratio, 29±2.8 vs. 43±3.3%; P<0.05) and pulmonary arterioles intimal proliferation (grade 1 and 2 occlusion, 24 and 20% vs. 44 and 40%; P<0.05) in pulmonary hypertensive rats. By contrast, DCA treatment initiated 29 days following pneumonectomy did not result in any improvement in pulmonary circulatory parameters or regression of occlusive neointimal lesions. Immunohistochemical and immunoblot assays demonstrated markedly reduced hypoxia inducible factor (HIF-1?) levels, and increased voltage-dependent potassium channel subtype 1.5 (Kv1.5) expression levels were observed in those neointimal regions in rats receiving DCA preventive therapy. Furthermore, preventive treatment with DCA significantly increased the activity of copper/zinc superoxide dismutase (Cu/Zn SOD activity, 88±4.2 vs. 53±2.7 U/mgprot; P<0.05) and promoted the degradation of ROS (106±4.7 vs. 79±13.3 U/mgprot; P<0.05), which was compromised in the delayed intervention group. Therefore, DCA is effective to prevent the formation of intimal lesions, which may be attributed to the induction of the upregulation of Cu/Zn SOD activity and the suppression of HIF-1? activation.
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Leptospira and leptospirosis in China.
Curr. Opin. Infect. Dis.
PUBLISHED: 07-26-2014
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In this review, we introduce the epidemiological features, clinical types, laboratory diagnosis, and routine surveillance of leptospirosis in China.
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Antibodies against severe fever with thrombocytopenia syndrome virus in healthy persons, China, 2013.
Emerging Infect. Dis.
PUBLISHED: 07-26-2014
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In June 2013, a subclinical infection with severe fever with thrombocytopenia syndrome virus (SFTSV) was detected in Zhejiang Province, China, prompting seroprevalence studies in 6 districts within the province. Of 986 healthy persons tested, 71 had IgG antibodies against SFTSV. This finding suggests that most natural infections with SFTSV are mild or subclinical.
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Childhood renal tumor: a report from a Chinese Children's Cancer Group.
Biomed Res Int
PUBLISHED: 07-24-2014
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Here we investigated the establishment of multicenter cooperative treatment groups in China, as well as radiotherapy compliance and effectiveness among children with renal tumors. Medical records were reviewed for 316 children with renal tumors diagnosed by a multicenter cooperative group from 14 hospitals in China from 1998 to 2012. Median patient age was 29.5 months (range, 2-173 months old), and male-to-female ratio was 1.4 : 1. After a median follow-up of 22 months (range, 1-177 months), five-year event-free survival rates were 72% overall; 76.1% for favorable histology (251 cases); 59% for unfavorable histology (27 cases); and 91%, 75%, 71%, 53%, and 48.5%, respectively for Stages I, II, III, IV, and V. Following standardized criteria, radiation therapy was indicated for 153 patients, among whom five-year event-free survival was 72.8% for the 95 who received radiation and 24% for the 58 patients who did not. Our results are reasonable but can be further improved and show the feasibility of a multicenter cooperative group model for childhood renal tumor treatment in China. Radiation therapy is important for stage III and IV patients but remains difficult to implement in some parts of China. Government management departments and medical professionals must pay attention to this situation. This clinical trial is registered with ChiCTR-PRCH-14004372.
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Dynamics and stability of polymorphic human telomeric G-quadruplex under tension.
Nucleic Acids Res.
PUBLISHED: 07-10-2014
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As critical DNA structures capping the human chromosome ends, the stability and structural polymorphism of human telomeric G-quadruplex (G4) have drawn increasing attention in recent years. This work characterizes the equilibrium transitions of single-molecule telomeric G4 at physiological K(+) concentration. We report three folded states of telomeric G4 with markedly different lifetime and mechanical stability. Our results show that the kinetically favored folding pathway is through a short-lived intermediate state to a longer-lived state. By examining the force dependence of transition rates, the force-dependent transition free energy landscape for this pathway is determined. In addition, an ultra-long-lived form of telomeric G4 structure with a much stronger mechanical stability is identified.
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Mutational analysis of ABCC8, KCNJ11, GLUD1, HNF4A and GCK genes in 30 Chinese patients with congenital hyperinsulinism.
Endocr. J.
PUBLISHED: 07-08-2014
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We conducted a cohort study to elucidate the molecular spectrum of congenital hyperinsulinism (CHI) in Chinese pediatric patients. Thirty Chinese children with CHI were chosen as research subjects, 16 of whom were responsive to diazoxide and 13 of whom were not (1 patient was not given the drug for medical reasons). All exons of the adenosine triphosphate (ATP)-sensitive potassium channel (KATP channel) genes KCNJ11 and ABCC8, the hepatocyte nuclear factor 4 ? (HNF4A) gene, and the Glucokinase (GCK) gene as well as exons 6 and 7 and 10-12 of the glutamate dehydrogenase 1 (GLUD1) gene were amplified from genomic DNA and directly sequenced. Mutations were identified in 14 of 30 patients (47%): 3 in GLUD1 (10%) and 11 in the KATP channel genes (37%). Six patients had paternally derived monoallelic KATP channel mutations predictive of the focal CHI form. We found a novel de novo ABCC8 mutation, p. C1000*, a novel paternally inherited ABCC8 mutation, D1505H, and a dominantly inherited ABCC8 mutation, R1217K. The GLUD1 activating mutation R269H was found in 2 patients: 1 de novo and the other paternally inherited. A de novo S445L mutation was found in 1 patient. No significant HNF4A or GCK mutations were found. CHI has complex genetic onset mechanisms. Paternally inherited monoallelic mutations of ABCC8 and KCNJ11 are likely the main causes of KATP-CHI in Chinese patients. Glutamate dehydrogenase-CHI is the second most common cause of CHI, while HNF4A and GCK are rare types of CHI in Chinese patients.
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Single-molecule studies on the mechanical interplay between DNA supercoiling and H-NS DNA architectural properties.
Nucleic Acids Res.
PUBLISHED: 07-02-2014
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The Escherichia coli H-NS protein is a major nucleoid-associated protein that is involved in chromosomal DNA packaging and gene regulatory functions. These biological processes are intimately related to the DNA supercoiling state and thus suggest a direct relationship between H-NS binding and DNA supercoiling. Here, we show that H-NS, which has two distinct DNA-binding modes, is able to differentially regulate DNA supercoiling. H-NS DNA-stiffening mode caused by nucleoprotein filament formation is able to suppress DNA plectoneme formation during DNA supercoiling. In contrast, when H-NS is in its DNA-bridging mode, it is able to promote DNA plectoneme formation during DNA supercoiling. In addition, the DNA-bridging mode is able to block twists diffusion thus trapping DNA in supercoiled domains. Overall, this work reveals the mechanical interplay between H-NS and DNA supercoiling which provides insights to H-NS organization of chromosomal DNA based on its two distinct DNA architectural properties.
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[Study on composition of essential oil in above-ground and root of Bupleurum malconense and root of B. chinense by AMDIS and retention index].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 06-25-2014
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Chemical constituents of the essential oil in above-ground and root of Bupleurum malconense and root of B. chinense were investigated by GC-MS compiled with automated mass spectral deconvolution and identification system (AMDIS) and retention index. The results showd that the components of essential oil in B. malconense have some similarities with the one in B. chinense, and both of them have the higher content of caryophyllene oxide which is an active component of anti-inflammatory and analgesic. These results suggested that as a local substitute, B. malconense has a certain scientific basis of the treatment for cold fever.
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Gonadotropin-mediated dynamic alterations during bovine oocyte maturation in vitro.
Biol. Reprod.
PUBLISHED: 06-18-2014
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Gonadotropins have been widely used in human-assisted reproduction and animal science for the past four decades. However, the effects of gonadotropins on oocyte maturation at the molecular and biochemical levels are poorly understood. To determine the effects of gonadotropins (recombinant follicle stimulating hormone and urinary human menopausal gonadotropin) on oocyte maturation, we used the bovine oocyte in vitro maturation model. First, we studied the effects of increasing gonadotropin concentrations on nuclear maturation and mitochondrial function in oocytes. Gonadotropins at concentrations of 0.075 and 0.75 IU/ml improved nuclear maturation and increased inner mitochondrial membrane potential and ATP levels; however, there were no beneficial effects at concentrations of 7.5 and 75 IU/ml. Second, we studied the effects of increasing gonadotropin concentrations on the status of methylation in matured (MII) oocytes. Aberrant methylation and demethylation of H19, SNRPN, and PEG3 genes were observed in MII oocytes at all concentrations except 0.075 IU/ml. The expression of genes that function in spindle formation, cell cycle control, and methylation was also downregulated by high gonadotropin concentrations. In conclusion, we established the optimal gonadotropin concentration (i.e., 0.075 IU/ml) to be used for bovine oocyte in vitro maturation studies. These results may provide a guide for clinical stimulation protocols and help to reduce the risks associated with gonadotropin administration during in vitro fertilization treatment.
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The proteins encoded by the Drosophila Planar Polarity Effector genes inturned, fuzzy and fritz interact physically and can re-pattern the accumulation of "upstream" Planar Cell Polarity proteins.
Dev. Biol.
PUBLISHED: 06-05-2014
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The frizzled/starry night pathway regulates planar cell polarity in a wide variety of tissues in many types of animals. It was discovered and has been most intensively studied in the Drosophila wing where it controls the formation of the array of distally pointing hairs that cover the wing. The pathway does this by restricting the activation of the cytoskeleton to the distal edge of wing cells. This results in hairs initiating at the distal edge and growing in the distal direction. All of the proteins encoded by genes in the pathway accumulate asymmetrically in wing cells. The pathway is a hierarchy with the Planar Cell Polarity (PCP) genes (aka the core genes) functioning as a group upstream of the Planar Polarity Effector (PPE) genes which in turn function as a group upstream of multiple wing hairs. Upstream proteins, such as Frizzled accumulate on either the distal and/or proximal edges of wing cells. Downstream PPE proteins accumulate on the proximal edge under the instruction of the upstream proteins. A variety of types of data support this hierarchy, however, we have found that when over expressed the PPE proteins can alter both the subcellular location and level of accumulation of the upstream proteins. Thus, the epistatic relationship is context dependent. We further show that the PPE proteins interact physically and can modulate the accumulation of each other in wing cells. We also find that over expression of Frtz results in a marked delay in hair initiation suggesting that it has a separate role/activity in regulating the cytoskeleton that is not shared by other members of the group.
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The DNA methylation landscape of human early embryos.
Nature
PUBLISHED: 05-30-2014
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DNA methylation is a crucial element in the epigenetic regulation of mammalian embryonic development. However, its dynamic patterns have not been analysed at the genome scale in human pre-implantation embryos due to technical difficulties and the scarcity of required materials. Here we systematically profile the methylome of human early embryos from the zygotic stage through to post-implantation by reduced representation bisulphite sequencing and whole-genome bisulphite sequencing. We show that the major wave of genome-wide demethylation is complete at the 2-cell stage, contrary to previous observations in mice. Moreover, the demethylation of the paternal genome is much faster than that of the maternal genome, and by the end of the zygotic stage the genome-wide methylation level in male pronuclei is already lower than that in female pronuclei. The inverse correlation between promoter methylation and gene expression gradually strengthens during early embryonic development, reaching its peak at the post-implantation stage. Furthermore, we show that active genes, with the trimethylation of histone H3 at lysine 4 (H3K4me3) mark at the promoter regions in pluripotent human embryonic stem cells, are essentially devoid of DNA methylation in both mature gametes and throughout pre-implantation development. Finally, we also show that long interspersed nuclear elements or short interspersed nuclear elements that are evolutionarily young are demethylated to a milder extent compared to older elements in the same family and have higher abundance of transcripts, indicating that early embryos tend to retain higher residual methylation at the evolutionarily younger and more active transposable elements. Our work provides insights into the critical features of the methylome of human early embryos, as well as its functional relation to the regulation of gene expression and the repression of transposable elements.
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[Prognostic significance of early lactate clearance rate for severe acute respiratory failure patients on extracorporeal membrane oxygenation].
Zhonghua Jie He He Hu Xi Za Zhi
PUBLISHED: 05-10-2014
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To investigate the prognostic significance of early lactate clearance rate for severe acute respiratory failure patients on extracorporeal membrane oxygenation (ECMO).
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Toll-like receptor 2 promotes invasion by SGC-7901 human gastric carcinoma cells and is associated with gastric carcinoma metastasis.
Ann. Clin. Lab. Sci.
PUBLISHED: 05-06-2014
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Toll-like receptors (TLRs) play a key role in cancer metastasis. The biological role of TLR2 in invasion and metastasis in gastric carcinoma cells and gastric carcinoma is not clear; therefore, we aimed to investigate the biological role of TLR2 in invasion by SGC-7901 human gastric carcinoma cells and to determine whether TLR2 is associated with gastric carcinoma metastasis. RT-PCR, real-time PCR, flow cytometry, and western blotting showed that TLR2 activation significantly increased TLR2 expression at the mRNA and protein levels and notably promoted the transcription of genes related to angiogenesis and invasion, such as VEGF-C and MMP-9. The invasive capacity of SGC-7901 cells was strikingly advanced by TLR2 stimulation on Transwell invasion assay. IL-6 in the supernatants of cultured SGC-7901 cells was increased under the condition of TLR2 stimulation and reduced after TLR2 blockade by ELISA. Combined with clinicopathological parameters, the expression of TLR2 protein examined by immunohistochemical analysis was higher in gastric carcinoma tissues than in adjacent non-cancerous tissues (p<0.001). There was a significant relationship between TLR2 expression and lymph node metastasis (p<0.01), distant metastasis (p<0.01). There was no significant correlation between gastric carcinoma and age (p>0.05), sex (p>0.05), or degree of differentiation (p>0.05). These findings indicate that TLR2 may participate in the progression and metastasis of human gastric carcinoma and provide a new therapeutic target against metastasis of gastric carcinoma.
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TRIM4 modulates type I interferon induction and cellular antiviral response by targeting RIG-I for K63-linked ubiquitination.
J Mol Cell Biol
PUBLISHED: 04-24-2014
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RIG-I is a pivotal cytoplasmic sensor that recognizes different species of viral RNAs. This recognition leads to activation of the transcription factors NF-?B and IRF3, which collaborate to induce type I interferons (IFNs) and innate antiviral response. In this study, we identified the TRIM family protein TRIM4 as a positive regulator of RIG-I-mediated IFN induction. Overexpression of TRIM4 potentiated virus-triggered activation of IRF3 and NF-?B, as well as IFN-? induction, whereas knockdown of TRIM4 had opposite effects. Mechanistically, TRIM4 associates with RIG-I and targets it for K63-linked polyubiquitination. Our findings demonstrate that TRIM4 is an important regulator of the virus-induced IFN induction pathways by mediating RIG-I for K63-linked ubiquitination.
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[DNA polymerase delta-interacting protein 1 enhances GFP protein degradation].
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi
PUBLISHED: 04-12-2014
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To prove whether the over-expression of DNA polymerase delta-interacting protein 1 (PDIP1) protein can promote the degradation of exogenous GFP protein.
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Nonracemic synthesis of GK-GKRP disruptor AMG-3969.
J. Org. Chem.
PUBLISHED: 04-10-2014
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A nonracemic synthesis of the glucokinase-glucokinase regulatory protein disruptor AMG-3969 (5) is reported. Key features of the synthetic approach are an asymmetric synthesis of the 2-alkynyl piperazine core via a base-promoted isomerization and a revised approach to the synthesis of the aminopyridinesulfonamide with an improved safety profile.
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Advances in preimplantation genetic diagnosis/screening.
Sci China Life Sci
PUBLISHED: 04-09-2014
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Preimplantation genetic diagnosis (PGD) gives couples who have a high risk of transmitting genetic disorders to their baby the chance to have a healthy offspring through embryo genetic analysis and selection. Preimplantation genetic screening (PGS) is an effective method to select euploid embryos that may prevent repeated implantation failure or miscarriage. However, how and to whom PGS should be provided is a controversial topic. The first successful case of PGD of a human being was reported in 1990, and there have been tremendous improvements in this technology since then. Both embryo biopsy and genetic technologies have been improved dramatically, which increase the accuracy and expand the indications of PGD/PGS.
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Immunogenicity of a West Nile virus DIII-cholera toxin A2/B chimera after intranasal delivery.
Toxins (Basel)
PUBLISHED: 04-09-2014
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West Nile virus (WNV) causes potentially fatal neuroinvasive disease and persists at endemic levels in many parts of the world. Despite advances in our understanding of WNV pathogenesis, there remains a significant need for a human vaccine. The domain III (DIII) region of the WNV envelope protein contains epitopes that are the target of neutralizing antibodies. We have constructed a chimeric fusion of the non-toxic cholera toxin (CT) CTA2/B domains to DIII for investigation as a novel mucosally-delivered WNV vaccine. Purification and assembly of the chimera, as well as receptor-binding and antigen delivery, were verified by western blot, GM1 ELISA and confocal microscopy. Groups of BALB/c mice were immunized intranasally with DIII-CTA2/B, DIII, DIII mixed with CTA2/B, or CTA2/B control, and boosted at 10 days. Analysis of serum IgG after 14 and 45 days revealed that mucosal immunization with DIII-CTA2/B induced significant DIII-specific humoral immunity and drove isotype switching to IgG2a. The DIII-CTA2/B chimera also induced antigen-specific IgM and IgA responses. Bactericidal assays indicate that the DIII-CTA2/B immunized mice produced DIII-specific antibodies that can trigger complement-mediated killing. A dose escalation resulted in increased DIII-specific serum IgG titers on day 45. DIII antigen alone, in the absence of adjuvant, also induced significant systemic responses after intranasal delivery. Our results indicate that the DIII-CTA2/B chimera is immunogenic after intranasal delivery and merits further investigation as a novel WNV vaccine candidate.
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KCNJ11 gene mutation analysis on nine Chinese patients with type 1B diabetes diagnosed before 3 years of age.
J. Pediatr. Endocrinol. Metab.
PUBLISHED: 04-05-2014
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The term type 1B diabetes mellitus (T1BDM) refers tonon-autoimmune-mediated type 1 diabetes. Recent studies revealed that monogenic mutations contribute to the genetic onset mechanism of this group. In this study, nine patients with T1BDM were selected as research subjects, and the 5' untranslated region and the exon of KCNJ11 gene were sequenced in order to study the genetic onset mechanism of T1BDM.
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Tracheal rupture related to endotracheal intubation after thyroid surgery: a case report and systematic review.
Int Wound J
PUBLISHED: 03-25-2014
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Tracheobronchial rupture is an uncommon but potentially serious complication of endotracheal intubation. The most likely cause of tracheal injury is massive overinflation of the endotracheal tube cuff and pre-existing tracheal wall weakness. We review the relevant literature and predisposing factors contributing to this complication. Only articles that reported at least the demographic data (age and sex), the treatment performed and the outcome were included. Papers that did not detail these variables were excluded. We also focus on a case of tracheal laceration after tracheal intubation in a patient with severe thyroid carcinoma. This patient received surgical repair and recovered uneventfully. Two hundred and eight studies that reported cases or case series were selected for analysis. Most of the reported cases (57·2%) showed an uneventful recovery after surgical therapy. The overall mortality was 19·2% (40 patients). Our patient too recovered without any serious complication. Careful prevention, early detection and proper treatment of the problem are necessary when tracheal rupture occurs. The morbidity and mortality associated with tracheal injury mandate a high level of suspicion and expedient management.
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PER1 phosphorylation specifies feeding rhythm in mice.
Cell Rep
PUBLISHED: 03-25-2014
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Organization of circadian behavior, physiology, and metabolism is important for human health. An S662G mutation in hPER2 has been linked to familial advanced sleep-phase syndrome (FASPS). Although the paralogous phosphorylation site S714 in PER1 is conserved in mice, its specific function in circadian organization remains unknown. Here, we find that the PER1S714G mutation accelerates the molecular feedback loop. Furthermore, hPER1S714G mice, but not hPER2S662G mice, exhibit peak time of food intake that is several hours before daily energy expenditure peaks. Both the advanced feeding behavior and the accelerated clock disrupt the phase of expression of several key metabolic regulators in the liver and adipose tissue. Consequently, hPER1S714G mice rapidly develop obesity on a high-fat diet. Our studies demonstrate that PER1 and PER2 are linked to different downstream pathways and that PER1 maintains coherence between the circadian clock and energy metabolism.
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Locus of enterocyte effacement-encoded regulator (Ler) of pathogenic Escherichia coli competes off histone-like nucleoid-structuring protein (H-NS) through noncooperative DNA binding.
J. Biol. Chem.
PUBLISHED: 03-25-2014
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The locus of enterocyte effacement-encoded regulator (Ler) of enteropathogenic and enterohemorrhagic Escherichia coli (EPEC and EHEC) functions to activate transcription of virulence genes silenced by the histone-like nucleoid-structuring protein (H-NS). Despite its important role in the bacterial gene regulation, the binding mode of Ler to DNA and its mechanism in alleviating genes repressed by H-NS are largely unknown. In this study, we use magnetic tweezers to demonstrate that Ler binds extended DNA through a largely noncooperative process, which results in DNA stiffening and DNA folding depending on protein concentration. We also show that Ler can replace prebound H-NS on DNA over a range of potassium and magnesium concentrations. Our findings reveal the DNA binding properties of Ler and shed light to further understand the anti-silencing activity of Ler.
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Experimenting liver fibrosis diagnostic by two photon excitation microscopy and Bag-of-Features image classification.
Sci Rep
PUBLISHED: 03-24-2014
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The accurate staging of liver fibrosis is of paramount importance to determine the state of disease progression, therapy responses, and to optimize disease treatment strategies. Non-linear optical microscopy techniques such as two-photon excitation fluorescence (TPEF) and second harmonic generation (SHG) can image the endogenous signals of tissue structures and can be used for fibrosis assessment on non-stained tissue samples. While image analysis of collagen in SHG images was consistently addressed until now, cellular and tissue information included in TPEF images, such as inflammatory and hepatic cell damage, equally important as collagen deposition imaged by SHG, remain poorly exploited to date. We address this situation by experimenting liver fibrosis quantification and scoring using a combined approach based on TPEF liver surface imaging on a Thioacetamide-induced rat model and a gradient based Bag-of-Features (BoF) image classification strategy. We report the assessed performance results and discuss the influence of specific BoF parameters to the performance of the fibrosis scoring framework.
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Clinical analysis on 33 patients with hypothalamic syndrome in Chinese children.
J. Pediatr. Endocrinol. Metab.
PUBLISHED: 03-05-2014
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To investigate the etiology and clinical characteristics of hypothalamic syndrome in Chinese children.
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qFibrosis: a fully-quantitative innovative method incorporating histological features to facilitate accurate fibrosis scoring in animal model and chronic hepatitis B patients.
J. Hepatol.
PUBLISHED: 02-18-2014
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There is increasing need for accurate assessment of liver fibrosis/cirrhosis. We aimed to develop qFibrosis, a fully-automated assessment method combining quantification of histopathological architectural features, to address unmet needs in core biopsy evaluation of fibrosis in chronic hepatitis B (CHB) patients.
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Force-dependent conformational switch of ?-catenin controls vinculin binding.
Nat Commun
PUBLISHED: 02-04-2014
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Force sensing at cadherin-mediated adhesions is critical for their proper function. ?-Catenin, which links cadherins to actomyosin, has a crucial role in this mechanosensing process. It has been hypothesized that force promotes vinculin binding, although this has never been demonstrated. X-ray structure further suggests that ?-catenin adopts a stable auto-inhibitory conformation that makes the vinculin-binding site inaccessible. Here, by stretching single ?-catenin molecules using magnetic tweezers, we show that the subdomains MI vinculin-binding domain (VBD) to MIII unfold in three characteristic steps: a reversible step at ~5?pN and two non-equilibrium steps at 10-15?pN. 5?pN unfolding forces trigger vinculin binding to the MI domain in a 1:1 ratio with nanomolar affinity, preventing MI domain refolding after force is released. Our findings demonstrate that physiologically relevant forces reversibly unfurl ?-catenin, activating vinculin binding, which then stabilizes ?-catenin in its open conformation, transforming force into a sustainable biochemical signal.
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Mechanical activation of vinculin binding to talin locks talin in an unfolded conformation.
Sci Rep
PUBLISHED: 02-03-2014
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The force-dependent interaction between talin and vinculin plays a crucial role in the initiation and growth of focal adhesions. Here we use magnetic tweezers to characterise the mechano-sensitive compact N-terminal region of the talin rod, and show that the three helical bundles R1-R3 in this region unfold in three distinct steps consistent with the domains unfolding independently. Mechanical stretching of talin R1-R3 enhances its binding to vinculin and vinculin binding inhibits talin refolding after force is released. Mutations that stabilize R3 identify it as the initial mechano-sensing domain in talin, unfolding at ?5?pN, suggesting that 5?pN is the force threshold for vinculin binding and adhesion progression.
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Altered promoter methylation of PDK4, IL1 B, IL6, and TNF after Roux-en Y gastric bypass.
Surg Obes Relat Dis
PUBLISHED: 01-28-2014
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Early benefits of Roux-en Y gastric bypass (RYGB) are partly mediated by the caloric restriction that patients undergo before and acutely after the procedure. Altered DNA methylation occurs in metabolic diseases including obesity, as well as in skeletal, muscle eight months after RYGB. The objective of this study was to test whether promoter methylation of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PPARGC1 A), pyruvate dehydrogenase kinase isozyme-4 (PDK4), transcription factor A (TFAM), interleukin-1 beta (IL1 B), interleukin-6 (IL6) and tumor necrosis factor-? (TNF) is altered in blood after a very low calorie diet (VLCD) or RYGB.
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Orexin A attenuates the sleep-promoting effect of adenosine in the lateral hypothalamus of rats.
Neurosci Bull
PUBLISHED: 01-23-2014
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Orexin neurons within the lateral hypothalamus play a crucial role in the promotion and maintenance of arousal. Studies have strongly suggested that orexin neurons are an important target in endogenous adenosine-regulated sleep homeostasis. Orexin A induces a robust increase in the firing activity of orexin neurons, while adenosine has an inhibitory effect. Whether the excitatory action of orexins in the lateral hypothalamus actually promotes wakefulness and reverses the sleep-producing effect of adenosine in vivo is less clear. In this study, electroencephalographic and electromyographic recordings were used to investigate the effects of orexin A and adenosine on sleep and wakefulness in rats. We found that microinjection of orexin A into the lateral hypothalamus increased wakefulness with a concomitant reduction of sleep during the first 3 h of post-injection recording, and this was completely blocked by a selective antagonist for orexin receptor 1, SB 334867. The enhancement of wakefulness also occurred after application of the excitatory neurotransmitter glutamate in the first 3 h post-injection. However, in the presence of the NMDA receptor antagonist APV, orexin A did not induce any change of sleep and wakefulness in the first 3 h. Further, exogenous application of adenosine into the lateral hypothalamus induced a marked increase of sleep in the first 3-h post-injection. No significant change in sleep and wakefulness was detected after adenosine application followed by orexin A administration into the same brain area. These findings suggest that the sleep-promoting action of adenosine can be reversed by orexin A applied to the lateral hypothalamus, perhaps by exciting glutamatergic input to orexin neurons via the action of orexin receptor 1.
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Curcumin inhibits lung cancer cell migration and invasion through Rac1-dependent signaling pathway.
J. Nutr. Biochem.
PUBLISHED: 01-22-2014
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Curcumin, a natural and crystalline compound isolated from the plant Curcuma longa with low toxicity in normal cells, has been shown to protect against carcinogenesis and prevent tumor development. However, little is known about antimetastasis effects and mechanism of curcumin in lung cancer. Rac1 is an important small Rho GTPases family protein and has been widely implicated in cytoskeleton rearrangements and cancer cell migration, invasion and metastasis. In this study, we examined the influence of curcumin on in vitro invasiveness of human lung cancer cells and the expressions of Rac1. The results indicate that curcumin at 10 ?M slightly reduced the proliferation of 801D lung cancer cells but showed an obvious inhibitory effect on epidermal growth factor or transforming growth factor ?1-induced lung cancer cell migration and invasion. Meanwhile, we demonstrated that the suppression of invasiveness correlated with inhibition of Rac1/PAK1 signaling pathways and matrix metalloproteinase (MMP) 2 and 9 protein expression by combining curcumin treatment with the methods of Rac1 gene silence and overexpression in lung cancer cells. Laser confocal microscope also showed that Rac1-regulated actin cytoskeleton rearrangement may be involved in anti-invasion effect of curcumin on lung cancer cell. At last, through xenograft experiments, we confirmed the connection between Rac1 and the growth and metastasis inhibitory effect of curcumin in vivo. In summary, these data demonstrated that low-toxic levels of curcumin could efficiently inhibit migration and invasion of lung cancer cells through inhibition of Rac1/PAK1 signaling pathway and MMP-2 and MMP-9 expression, which provided a novel insight into the molecular mechanism of curcumin against lung cancer.
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Identification of collagenase as a critical virulence factor for invasiveness and transmission of pathogenic Leptospira species.
J. Infect. Dis.
PUBLISHED: 01-02-2014
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?Leptospirosis is a global zoonotic disease. Transmission of Leptospira from animals to humans occurs through contact with water contaminated with leptospire-containing urine of infected animals. However, the molecular basis for the invasiveness of Leptospira and transmission of leptospirosis remains unknown.
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Single-Molecule Study on Histone-Like Nucleoid-Structuring Protein (H-NS) Paralogue in Pseudomonas aeruginosa: MvaU Bears DNA Organization Mode Similarities to MvaT.
PLoS ONE
PUBLISHED: 01-01-2014
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Pseudomonas aeruginosa contains two distinct members of H-NS family of nucleoid-structuring proteins: MvaT and MvaU. Together, these proteins bind to the same regions of the chromosome and function coordinately in the regulation of hundreds of genes. Due to their structural similarity, they can associate to form heteromeric complexes. These findings left us wondering whether they bear similar DNA binding properties that underlie their gene-silencing functions. Using single-molecule stretching and imaging experiments, we found striking similarities in the DNA organization modes of MvaU compared to the previously studied MvaT. MvaU can form protective nucleoprotein filaments that are insensitive to environmental factors, consistent with its role as a repressor of gene expression. Similar to MvaT, MvaU filament can mediate DNA bridging while excessive MvaU can cause DNA aggregation. The almost identical DNA organization modes of MvaU and MvaT explain their functional redundancy, and raise an interesting question regarding the evolutionary benefits of having multiple H-NS paralogues in the Pseudomonas genus.
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Toll-Like Receptor 4 Prompts Human Breast Cancer Cells Invasiveness via Lipopolysaccharide Stimulation and Is Overexpressed in Patients with Lymph Node Metastasis.
PLoS ONE
PUBLISHED: 01-01-2014
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Toll-like receptor (TLR)4-mediated signaling has been implicated in tumor cell invasion, survival, and metastasis in a variety of cancers. This study investigated the expression and biological role of TLR4 in human breast cancer metastasis. MCF-7 and MDA-MB-231 are human breast cancer cell lines with low and high metastatic potential, respectively. Using lipopolysaccharide (LPS) to stimulate MCF-7 and MDA-MB-231 cells, expression of TLR4 mRNA and protein increased compared with that in control cells. TLR4 activation notably up-regulated expression of matrix metalloproteinase (MMP)-2, MMP-9 and vascular endothelial growth factor(VEGF) mRNA and their secretion in the supernatants of both cell lines. LPS enhanced invasion of MDA-MB-231 cells by transwell assay and MCF-7 cells by wound healing assay. LPS triggered increased expression of TLR4 downstream signaling pathway protein myeloid differentiation factor 88(MyD88) and resulted in interleukin (IL)-6 and IL-10 higher production by human breast cancer cells. Stimulation of TLR4 with LPS promoted tumorigenesis and formed metastatic lesions in liver of nude mice. Moreover, expression of TLR4 and MyD88 as well as invasiveness and migration of the cells could be blocked by TLR4 antagonist. Combined with clinicopathological parameters, TLR4 was overexpressed in human breast cancer tissue and correlated with lymph node metastasis. These findings indicated that TLR4 may participate in the progression and metastasis of human breast cancer and provide a new therapeutic target.
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[The value of changes in end-tidal carbon dioxide pressure induced by passive leg raising test in predicting fluid responsiveness in mechanically ventilated patients with septic shock].
Zhonghua Nei Ke Za Zhi
PUBLISHED: 11-09-2013
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To test whether the changes of partial end-tidal carbon dioxide pressure (PETCO2) during passive leg raising (PLR) predict fluid responsiveness in mechanically ventilated patients with septic shock.
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Gestational diabetes mellitus, programing and epigenetics.
J. Matern. Fetal. Neonatal. Med.
PUBLISHED: 10-30-2013
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Abstract Gestational diabetes mellitus (GDM) is a common medical complication in pregnancy. Offspring exposed to maternal hyperglycemia have a higher birth weight and are prone to develop metabolic disease in adult life. The intrauterine environmental or nutritional status seems to be involved in the fetal programing. The concept of "Developmental Origins of Health and Disease" (DOHaD) has been widely accepted and it brings new insights into the molecular pathogenesis of human diseases. The underlying mechanism is still under discussion and epigenetic mechanisms may provide an explanation for the phenomenon. The aim of this review is to illustrate the role of epigenetic modifications in the development of insulin resistance in metabolic diseases induced by adverse intrauterine exposures. Changes in epigenetic mechanism may be an early event in pathogenesis and progression of the metabolic disease in humans. Studies on epigenetic modifications contribute to our understanding of long-term effects of in utero exposure and shed light on the disease prevention and treatment by modulating epigenetic changes.
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[Research on methane concentration monitoring system based on electro-optical modulation interference].
Guang Pu Xue Yu Guang Pu Fen Xi
PUBLISHED: 10-29-2013
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Gas monitoring for methane concentration has been applied in many areas, while the vast majority of methods were based on the chemical reaction. There is a low security and poor stability shortcomings. In contrast, it is of high stability and strong anti-interference ability to monitor methane concentration using optical interferometry for quantitative analysis. As the system static interference limits the spectrcum resolution, we designed the electro-optical modulation interference system to further improve the detection accuracy for methane concentration. In the interferometer system, a variable refractive index crystal LiNbO3 was used for electro-optical modulation, and the static optical path length scan range was increased to improve the spectrum resolution. Both sides of the crystal were loaded with opposite phase modulated signal, so that it does not change the improved spectrum resolution interferometer size. By derivation of refractive index modulation as a function of optical path difference, the simulation found that the resolution was increased by nearly an order of magnitude than interference system spectrum resolution of the same size. The experiments used the SGT-3-type acousto-optical modulator and the 1 650 nm infrared lasers to detect different concentrations of methane gas. The experimental results show that the method is better than the traditional pyroelectric method in terms of accuracy and stability, and more suitable for application in the mine complex environment.
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A novel dynamic cardiac simulator utilizing pneumatic artificial muscle.
Conf Proc IEEE Eng Med Biol Soc
PUBLISHED: 10-11-2013
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With the development of methods and skills of minimally invasive surgeries, equipments for doctors training and practicing are in high demands. Especially for the cardiovascular surgeries, operators are requested to be familiar with the surgical environment of a beating heart. In this paper, we present a new dynamic cardiac simulator utilizing pneumatic artificial muscle to realize heartbeat. Its an artificial left ventricular of which the inner chamber is made of thermoplastic elastomers (TPE) with an anatomical structure of the real human heart. It is covered by another layer of material forming the artificial muscle which actuates the systole and diastole uniformly and omnidirectionally as the cardiac muscle does. Preliminary experiments were conducted to evaluate the performance of the simulator. The results indicated that the pressure at the terminal of the aorta could be controlled within the range of normal human systolic pressure, which quantitatively validated the new actuating mode of the heart-beating is effective.
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Functional and pathway enrichment analysis for integrated regulatory network of high- and low-metastatic lung cancer.
Mol Biosyst
PUBLISHED: 09-30-2013
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Metastasis is a common feature of lung cancer, involving relationships between genes, proteins and miRNAs. However, lack of early detection and limited options for targeted therapies are weaknesses that cantribute to the dismal statistics observed in lung cancer metastasis. In this paper, gene expression profiling analysis for genes differentially expressed between high- (95D) and low-metastatic lung cancer cell lines (95C) was performed using gene annotation, pathway analysis, literature mining, and the integrated regulatory network as well as motif analysis of miRNA-DEG and TF-DEG. In addition, the expression of EGR-1 (early growth reponse-1) in surgically resected lung squamous carcinomas, adenocarcinomas and normal lung tissue was detected by immunohistochemistry to reveal the relationships between EGR-1 and lung cancer metastasis. A total of 570 different expressed genes (DEGs) were screened, the vast majority of up-regulated DEGs were connected to cell adhesion and focal adhesion. EGR-1 was observed in the center node of the regulatory network, which seems to play a role in the process of cancer metastasis, and further immunohistochemistry detection confirmed this reasoning. Besides EGR-1, several significant module-related DEGs were enriched in the pathway within cancer and focal adhesion according to KEGG pathway enrichment analysis of network modules. The construction of an integrated regulatory network and the functional prediction of EGR-1 provided us with the cytological basis of lung cancer metastasis research and an understanding of the mechanism of metastasis in lung cancer. EGR-1 should be considered as a potential target gene in therapeutic agent for lung cancer metastasis.
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Downregulation of LIMK1 level inhibits migration of lung cancer cells and enhances sensitivity to chemotherapy drugs.
Oncol. Res.
PUBLISHED: 09-26-2013
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LIM kinase 1 (LIMK1) is a member of a novel class of serine-threonine protein kinases, which plays an important role in malignant transformation. High expression of LIM kinase 1 (LIMK1) has been detected in various invasive cancers. Here, we showed that LIMK1 was overexpressed in non-small cell lung cancer tissues (NSCLC) and cell lines. Expression of LIMK1 was detected in 115 of 150 lung cancer tissues, the frequency being more significant than in lung tissues. In addition, overexpression of LIMK1 was also associated with high TNM stage and lymph node metastasis in NSCLC patients. Moreover, RNAi-mediated suppression of LIMK1 expression markedly inhibited migration and invasion of 801D lung cancer cells. Furthermore, silencing of LIMK1 sensitized 801D cells to chemotherapeutic drugs of cisplatin and gemcitabine. These results indicate that the overexpression of LIMK1 is tightly associated with an aggressive phenotype of lung cancer cells, knockdown of LIMK1 suppressed cell migration and invasion, enhanced chemosensitivity, suggesting a potential therapeutic target for lung cancer.
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[Circadian clock gene Rev-erb-? deficiency prolongs female estrous cyclicity].
Sheng Li Xue Bao
PUBLISHED: 08-22-2013
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The circadian clock has been linked to female reproductive physiology and endocrine in mammals. Epidemiological studies of female shift workers have shown increased rates of abnormal reproduction and adverse pregnancy. But little is known how the circadian rhythms affect reproduction. The aim of the present study was to investigate the influences of circadian rhythms on estrous cycle in female mice using clock gene Rev-erb-? knock out (Rev-erb-?(-/-)) mice. To test the fertility of Rev-erb-?(-/-) mice, litter sizes were counted after mating with C57BL/6J male mice. HE staining was used to observe the change of follicle development. The number of embryos of Rev-erb-?(+/+) and Rev-erb-?(-/-) female mice was compared 1.5 d after mating with C57BL/6J male mice. Then Rev-erb-?(+/+) and Rev-erb-?(-/-) female mice were housed to adult, and daily vaginal lavage with 0.9% saline was used to monitor estrous cycle for at least 30 days. Quantity of various cells was counted on specified smears views after staining. We observed estrous cycles of Rev-erb-?(+/+) and Rev-erb-?(-/-) female mice using line plots and periodic spectrograms. The results showed that the Rev-erb-?(-/-) female mice were infertility, and the number of embryos of Rev-erb-?(-/-) females was less than that of Rev-erb-?(+/+) females. However, the follicle development of Rev-erb-?(-/-) female mice was normal. The estrous cycle of Rev-erb-?(-/-) female mice was 3.22 days longer than that of Rev-erb-?(+/+) female mice. The results suggest that loss of Rev-erb-? prolongs estrous cycle, which is probably one of the reasons for female mice infertility, and circadian rhythm is important for mammalian estrous cycle.
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Neonatal outcomes after the transfer of vitrified blastocysts: closed versus open vitrification system.
Reprod. Biol. Endocrinol.
PUBLISHED: 08-10-2013
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Increasing evidence indicates that closed vitrification has been successfully used in the cryopreservation of human oocytes and embryos. Little information is available regarding the neonatal outcome of closed blastocysts vitrification. The aim of this study was to evaluate the effectiveness and safety of blastocyst vitrification using a high-security closed vitrification system compared with an open vitrification system.
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[An analysis of clinical characteristics of septic acute kidney injury by using criteria of Kidney Disease: Improving Global Outcomes].
Zhonghua Nei Ke Za Zhi
PUBLISHED: 08-09-2013
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To evaluate the value of Kidney Disease: Improving Global Outcomes (KDIGO) criteria in investigating clinical feature and prognosis of acute kidney injury (AKI) patients with sepsis in ICU.
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[ABCC8, KCNJ11 and GLUD1 gene mutation analysis in congenital hyperinsulinism pedigree].
Zhonghua Yi Xue Za Zhi
PUBLISHED: 08-02-2013
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To explore the ABCC8, KCNJ11, and GLUD1 gene mutations of the 11 patients diagnosed as congenital hyperinsulinism (CHI).
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Improvement in the quality of heterotopic allotransplanted mouse ovarian tissues with basic fibroblast growth factor and fibrin hydrogel.
Hum. Reprod.
PUBLISHED: 07-25-2013
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Does basic fibroblast growth factor (bFGF) in combination with fibrin hydrogel improve follicle development and revascularization of heterotopically transplanted mouse ovarian tissues?
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Two distinct phenotypes in pigmented cells of different embryonic origins in eyes of pale ear mice.
Exp. Eye Res.
PUBLISHED: 07-22-2013
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The eye has pigmented cells of two different embryonic origins and therefore it is a good model for studying melanosome biogenesis and melanin production/deposition. Pale ear mice bear a mutation in the Hermansky-Pudlak syndrome type 1 (HPS-1) gene and exhibit abnormal eye pigmentation. Here, we reported the delayed and reduced pigmentation in eyes of pale ear mice in early postnatal stages and adulthood. Tyrosinase assay and l-3,4-dihydroxyphenylalanine (l-DOPA) gel staining assay revealed that tyrosinase activity in eyes of pale ear mutants was greatly reduced in early postnatal stages and increased gradually after postnatal day 7 (P7). Further histological examination revealed that hypopigmentation in the retinal pigment epithelium (RPE) and pigment epithelium of the iris and ciliary body, which are derived from the optic cup, was more severe than that in neural crest-derived tissues. In addition, macromelanosomes were exclusively present in neural crest-derived melanocytes of pale ear adults, but absent at early postnatal stages. Taken together, the mutation in the HPS-1 gene could cause two distinct phenotypes in pigmented cells of different embryonic origins. Besides, an increased accumulation of lipofuscin in RPE was also observed.
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Single-cell RNA-Seq profiling of human preimplantation embryos and embryonic stem cells.
Nat. Struct. Mol. Biol.
PUBLISHED: 07-18-2013
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Measuring gene expression in individual cells is crucial for understanding the gene regulatory network controlling human embryonic development. Here we apply single-cell RNA sequencing (RNA-Seq) analysis to 124 individual cells from human preimplantation embryos and human embryonic stem cells (hESCs) at different passages. The number of maternally expressed genes detected in our data set is 22,687, including 8,701 long noncoding RNAs (lncRNAs), which represents a significant increase from 9,735 maternal genes detected previously by cDNA microarray. We discovered 2,733 novel lncRNAs, many of which are expressed in specific developmental stages. To address the long-standing question whether gene expression signatures of human epiblast (EPI) and in vitro hESCs are the same, we found that EPI cells and primary hESC outgrowth have dramatically different transcriptomes, with 1,498 genes showing differential expression between them. This work provides a comprehensive framework of the transcriptome landscapes of human early embryos and hESCs.
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Complete mitochondrial genome of the San Lucan gecko, Phyllodactylus unctus (Sauria, Gekkota, Phyllodactylidae), in comparison with Tarentola mauritanica.
Mitochondrial DNA
PUBLISHED: 06-24-2013
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Abstract We sequenced the complete mitochondrial genome of the San Lucan gecko, Phyllodactylus unctus, which is endemic to Mexico. The complete mitochondrial genome was 16,881?bp in size, consisting of 37 genes coding for 13 proteins, 2 rRNAs, 22 tRNAs and 1 control region. Its gene arrangement pattern was identical with most vertebrates. We compared the mitochondrial genome of P. unctus with that of the Moorish gecko, Tarentola mauritanica, which is the only other sequenced species from Phyllodactylidae. Nucleotide sequence divergence (p distance) between two mitochondrial genomes was 31.32%. The detailed comparison between the mitochondrial genomes of two species was done.
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Epidemiological survey and risk factor analysis of fatty liver disease of adult residents, Beijing, China.
J. Gastroenterol. Hepatol.
PUBLISHED: 05-18-2013
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With the changes in diet structure and lifestyle, the incidence of fatty liver disease is increasing in China, especially in cities. The goal of the present study was to accurately determine the prevalence and risk factors of fatty liver disease in Beijing residents, China.
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Transmembrane Protein 214 (TMEM214) mediates endoplasmic reticulum stress-induced caspase 4 enzyme activation and apoptosis.
J. Biol. Chem.
PUBLISHED: 05-09-2013
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Endoplasmic reticulum (ER) stress caused by excessive aggregation of misfolded proteins induces apoptosis. Although ER stress-induced apoptosis has been implicated in many diseases, the detailed mechanisms are not well understood. Here, we identified human transmembrane protein 214 (TMEM214) as a critical mediator of ER stress-induced apoptosis. Overexpression of TMEM214 induced apoptosis, whereas knockdown of TMEM214 inhibited ER stress-induced apoptosis. TMEM214 was localized on the outer membrane of the ER and constitutively associated with procaspase 4, which was also critical for ER stress-induced apoptosis. TMEM214-induced apoptosis was abolished by a dominant negative mutant of procaspase 4, whereas caspase 4-induced apoptosis was inhibited by knockdown of TMEM214. Furthermore, knockdown of TMEM214 inhibited the activation and cleavage of procaspase 4 by impairing its recruitment to the ER. Our findings suggest that TMEM214 is essential for ER stress-induced apoptosis by acting as an anchor for recruitment of procaspase 4 to the ER and its subsequent activation.
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Identification and primary immune characteristics of an amphioxus akirin homolog.
Fish Shellfish Immunol.
PUBLISHED: 05-07-2013
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Akirin is a recently described nuclear protein that is thought to be required for the NF-?B signaling pathway in insects and vertebrates. Here, functional investigations of akirin are described in the basal chordate amphioxus Branchiostoma belcheri tsingtauense in an attempt to link this gene between insect and vertebrate lineages. Phylogenetic analysis indicated that amphioxus akirin represented a true ortholog of the two characterized vertebrate akirin paralogs. Amphioxus akirin, coding 219 amino acids with two nuclear localization signal (NLS) sequences and one 14-3-3 binding motif, was widely expressed in various tissues and up-regulated in response to Escherichia coli (Gram-negative bacterium) and Staphylococcus aureus (Gram-positive bacterium) challenges. Furthermore, amphioxus akirin was strictly localized to the nucleus of HEK293T cells in a confocal analysis. Our work identified and characterized for the first time an amphioxus akirin homolog and will promote a better understanding of the evolution and transcriptional network of the akirin gene family.
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Robust cell size checkpoint from spatiotemporal positive feedback loop in fission yeast.
Biomed Res Int
PUBLISHED: 04-29-2013
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Cells must maintain appropriate cell size during proliferation. Size control may be regulated by a size checkpoint that couples cell size to cell division. Biological experimental data suggests that the cell size is coupled to the cell cycle in two ways: the rates of protein synthesis and the cell polarity protein kinase Pom1 provide spatial information that is used to regulate mitosis inhibitor Wee1. Here a mathematical model involving these spatiotemporal regulations was developed and used to explore the mechanisms underlying the size checkpoint in fission yeast. Bifurcation analysis shows that when the spatiotemporal regulation is coupled to the positive feedback loops (active Cdc2 promotes its activator, Cdc25, and suppress its inhibitor, Wee1), the mitosis-promoting factor (MPF) exhibits a bistable steady-state relationship with the cell size. The switch-like response from the positive feedback loops naturally generates the cell size checkpoint. Further analysis indicated that the spatial regulation provided by Pom1 enhances the robustness of the size checkpoint in fission yeast. This was consistent with experimental data.
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Mechanosensing of DNA bending in a single specific protein-DNA complex.
Sci Rep
PUBLISHED: 04-25-2013
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Many crucial biological processes are regulated by mechanical stimuli. Here, we report new findings that pico-Newton forces can drastically affect the stability of the site-specific DNA binding of a single transcription factor, the E. coli integration host factor (IHF), by stretching a short ~150?nm DNA containing a single IHF binding site. Dynamic binding and unbinding of single IHF were recorded and analyzed for the force-dependent stability of the IHF-DNA complex. Our results demonstrate that the IHF-DNA interaction is fine tuned by force in different salt concentration and temperature over physiological ranges, indicating that, besides other physiological factors, force may play equally important role in transcription regulation. These findings have broad implications with regard to general mechanosensitivity of site-specific DNA bending proteins.
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Establishment of a novel one-step reverse transcription loop-mediated isothermal amplification assay for rapid identification of RNA from the severe fever with thrombocytopenia syndrome virus.
J. Virol. Methods
PUBLISHED: 04-18-2013
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As an emerging infectious disease, severe fever with thrombocytopenia syndrome virus (SFTSV) infection has been found in many areas of China. Suitable laboratory diagnostic method is urgently needed in clinical detections and epidemiological investigations. In this study, a modified, low-cost and rapid visualized one-step reverse transcription loop-mediated isothermal amplification (RT-LAMP) method for the detection of RNA from the SFTSV has been established. In order to avoid the risk of aerosol contamination and facilitate the naked eye to observe, a microcrystalline wax-dye capsule wrapping the highly sensitive DNA fluorescence dye SYBR Green I was added to the RT-LAMP reaction tube before the initiation of the assay. The detection limit of the established RT-LAMP assay was 10 fg template RNA per reaction mixture. The RT-LAMP assay was confirmed to be high specific to SFTSV, and no cross-reaction was found with the detection of the Chikungunya fever virus, Hemorrhagic Fever with Renal Syndrome virus (HFRSV), and Dengue fever virus. The assay was then applied for the detection of SFTSV RNA in 32 clinical serum samples and showed 94.4% consistence with the detection results of the real-time RT-PCR. The whole process, from sample preparation to result reporting, can be completed within 2h. This adapted, cost efficient and quick visualized RT-LAMP method is feasible for SFTSV field diagnosis in resource-limited field settings.
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Functional inactivation of orexin 1 receptors in the cerebellum disrupts trace eyeblink conditioning and local theta oscillations in guinea pigs.
Behav. Brain Res.
PUBLISHED: 04-04-2013
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The cerebellum plays an essential role in motor learning. Recently, orexins, the newfound lateral hypothalamic neuropeptides, have been found to excite Purkinje cells in the cerebellar cortex and neurons in the deep cerebellar nuclei (DCN). However, little is known about their roles in cerebellum-dependent motor learning. Therefore, the present study was designed to investigate the functional significance of hypothalamic orexinergic system during trace eyeblink conditioning, a tractable behavioral model system of cerebellum-dependent motor learning. It was revealed that the orexin 1 receptors (OXR1) were specifically localized on the soma of Purkinje cells and large DCN neurons. Furthermore, interfering with the endogenous orexins effects on the cerebellum via the selective OXR1 antagonist SB-334867 disrupted the timing rather than the acquisition of trace conditioned eyeblink responses. In addition to the behavioral effects, the SB-334867 prevented the increase in peak amplitude of cerebellar theta oscillations with learning. These results suggest that the endogenous orexins may modulate motor learning via the activation of cerebellar OXR1.
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Addition of SNAP to perinatal risk factors improves the prediction of bronchopulmonary dysplasia or death in critically ill preterm infants.
BMC Pediatr
PUBLISHED: 03-18-2013
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Bronchopulmonary dysplasia (BPD) is the most common serious pulmonary morbidity in premature infants. The score for neonatal acute physiology (SNAP) is a physiologic severity index for neonatal intensive care and correlates well with neonatal mortality and clinical outcomes. The prognostic value of the SNAP score for BPD in preterm infants remains to be clarified. The aim of the study was to determine whether SNAP can predict the development of BPD or death, and to investigate the contribution of SNAP to the predictive accuracy of other potential perinatal risk factors for the adverse outcome in critically ill preterm infants.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.