Angiosperm seeds usually consist of two major parts： the embryo and the endosperm. However, the molec- ular mechanism（s） underlying embryo and endosperm development remains largely unknown, particularly in rice, th...Angiosperm seeds usually consist of two major parts： the embryo and the endosperm. However, the molec- ular mechanism（s） underlying embryo and endosperm development remains largely unknown, particularly in rice, the model cereal. Here, we report the identification and functional characterization of the rice GIANT EMBRYO （GE） gene. Mutation of GE resulted in a large embryo in the seed, which was caused by excessive expansion of scuteUum cells. Post-embryonic growth of ge seedling was severely inhibited due to defective shoot apical meristem （SAM） mainte- nance. Map-based cloning revealed that GE encodes a CYP78A subfamily P450 monooxygenase that is localized to the endoplasmic reticulum. GE is expressed predominantly in the scutellar epithelium, the interface region between embryo and endosperm. Overexpression of GE promoted cell proliferation and enhanced rice plant growth and grain yield, but reduced embryo size, suggesting that GE is critical for coordinating rice embryo and endosperm development. Moreover, transgenic Arabidopsis plants overexpressing AtCYP78AlO, a GE homolog, also produced bigger seeds, implying a con- served role for the CYP78A subfamily of P450s in regulating seed development. Taken together, our results indicate that GE plays critical roles in regulating embryo development and SAM maintenance.展开更多
AIM:To investigate whether miRNA-155(miR-155)dysregulates apical junctional complex(AJC)protein expression in experimental severe acute pancreatitis(SAP).METHODS:Twenty-four male BALB/c mice were randomly assigned to ...AIM:To investigate whether miRNA-155(miR-155)dysregulates apical junctional complex(AJC)protein expression in experimental severe acute pancreatitis(SAP).METHODS:Twenty-four male BALB/c mice were randomly assigned to two groups:the SAP group(n=12)receiving sequential intraperitoneal injection of 50μg/kg caerulein and 10 mg/kg lipopolysaccharide over 6h,and the control group(n=12)receiving intraperitoneal injection of normal saline.Animals were sacrificed3 h following the last injection for collection of blood samples and pancreas and distal ileal segment specimens.Routine pancreas and intestine histology was used to assess SAP pathology and intestinal epithelial barrier damage.Levels of serum amylase,diamine oxidase(DAO),and tumor necrosis factor(TNF)-αwere determined using commercial kits.Total RNA samples were isolated from intestinal epithelial specimens and reversely transcribed into cDNA.miR-155 and RhoA mRNA expression profiles were determined using quantitative real-time polymerase chain reaction.Target genes for miR-155 were predicted using the miRTarBase database,RNA22 and PicTar computational methods.Western blotting was performed to quantitate the protein expression levels of the target gene RhoA,as well as zonula occludens(ZO)-1 and E-cadherin,two AJC component proteins.RESULTS:Intraperitoneal injection of caerulein and lipopolysaccharide successfully induced experimental acute pancreatic damage(SAP vs control,10.0±2.0vs 3.2±1.2,P<0.01)and intestinal epithelial barrier damage(3.2±0.7 vs 1.4±0.7,P<0.01).Levels of serum amylase(21.6±5.1 U/mL vs 14.3±4.2 U/mL,P<0.01),DAO(21.4±4.1 mg/mL vs 2.6±0.8 mg/mL,P<0.01),and TNF-α(61.0±15.1 ng/mL vs 42.9±13.9 ng/mL,P<0.01)increased significantly in SAP mice compared to those in control mice.miR-155 was significantly overexpressed in SAP intestinal epithelia(1.94±0.50 fold vs 1.03±0.23 fold,P<0.01),and RhoA gene containing three miR-155-specific binding sites in the three prime untranslated regions was one of the target genes for miR-155.RhoA(22.7±5.展开更多
To investigate the prevalence of Enterococcus faecalis in saliva and filled root canals of patients requiring endodontic retreatment for apical periodontitis.Patients with apical periodontitis who were referred for en...To investigate the prevalence of Enterococcus faecalis in saliva and filled root canals of patients requiring endodontic retreatment for apical periodontitis.Patients with apical periodontitis who were referred for endodontic retreatment were examined.The type and quality of the restoration,symptoms,quality of obturation were recorded.During retreatment,an oral rinse sample and root canal sample were cultured using brain-heart infusion agar and bile esculinazide agar to select for E.faecalis.The 16S rRNA technique was used to identify E.faecalis.A total of 32 women and 22 men（mean age：38 years;s.d.：11 years） and 58 teeth were studied.The prevalence of E.faecalis was 19% in the saliva and 38% in the root canals.The odds that root canals harbored E.faecalis were increased if the saliva habored this bacterium（odds ratio59.7;95% confidence interval51.8-51.6;P,0.05）.Teeth with unsatisfactory root obturation had more cultivable bacterial species in root canals than teeth with satisfactory root obturation（P,0.05）.E.faecalis is more common in root canals of teeth with apical periodontitis than in saliva.The prevalence of E.faecalis in root canals is associated with the presence of E.faecalis in saliva.展开更多
As a cell cycle regulator, the Myb-related CDC5 protein was reported to be essential for the G2 phase of the cell cycle in yeast and animals, but little is known about its function in plants. Here we report the functi...As a cell cycle regulator, the Myb-related CDC5 protein was reported to be essential for the G2 phase of the cell cycle in yeast and animals, but little is known about its function in plants. Here we report the functional characterization of the CDC5 gene in Arabidopsis thaliana. Arabidopsis CDC5 （AtCDC5） is mainly expressed in tissues with high cell division activity, and is expressed throughout the entire process of embryo formation. The AtCDC5 loss-of-function mutant is embryonic lethal. In order to investigate the function of AtCDC5 in vivo, we generated AtCDC5-RNAi plants in which the expression of AtCDC5 was reduced by RNA interference. We found that the G2 to M （G2/M） phase transition was affected in the AtCDC5-RNAi plants, and that endoreduplication was increased. Additionally, the maintenance of shoot apical meristem （SAM） function was disturbed in the AtCDC5-RNAi plants, in which both the WUSCHEL （WUS）- CLAVATA （CLV） and the SHOOT MERISTEMLESS （STM） pathways were impaired. In situ hybridization analysis showed that the expression of STMwas greatly reduced in the shoot apical cells of the AtCDC5-RNAi plants. Moreover, cyclinB1 or Histone4 was found to be expressed in some of these cells when the transcript of STM was undetectable. These results suggest that AtCDC5 is essential for the G2/M phase transition and may regulate the function of SAM by controlling the expression ofSTMand WUS.展开更多
Apical hypertrophic cardiomyopathy(AHCM) is a relatively rare morphologic variant of HCM in which the hypertrophy of myocardium is localized to the left ventricular apex. Symptoms of AHCM might vary from none to other...Apical hypertrophic cardiomyopathy(AHCM) is a relatively rare morphologic variant of HCM in which the hypertrophy of myocardium is localized to the left ventricular apex. Symptoms of AHCM might vary from none to others mimic coronary artery disease including acute coronary syndrome, thus resulting in inappropriate hospitalization. Transthoracic echocardiography is the firstline imaging technique for the diagnosis of hypertrophic cardiomyopathies. However, when the hypertrophy of the myocardium is localized in the ventricular apex might results in missed diagnosis. Aim of this paper is to review the different imaging techniques used for the diagnosis of AHCM and their role in the detection and comprehension of this uncommon disease.展开更多
OBJECTIVE:To investigate the effect of spinal manipulation(SM)on degenerative scoliosis by evaluating patients’visual analog scale(VAS)scores,Cobb angles,sagittal vertical axis(SVA),and apical vertebral rotation(AVR)...OBJECTIVE:To investigate the effect of spinal manipulation(SM)on degenerative scoliosis by evaluating patients’visual analog scale(VAS)scores,Cobb angles,sagittal vertical axis(SVA),and apical vertebral rotation(AVR)and to explore factors that influence treatment effect.METHODS:A total of 55 patients with degenerative scoliosis received 4 weeks of SM.After treatment,patients were divided into two groups:the remission group(VAS score<40 mm)and the non-remission group(VAS score≥40 mm).Pre-versus post-treatment VAS scores,Cobb angles,SVA,and AVR were compared in each group and in the total population.Baseline data(sex,age,symptom characteristics,duration of symptoms,VAS score,Cobb angle,SVA,and AVR)were compared between groups.Factors influencing the post-treatment VAS score were explored with multiple linear regression analysis.RESULTS:No changes were found in the Cobb angle(P=0.722)or AVR(P=0.424)after intervention in the overall population.However,the SVA(P<0.001)and VAS score(P=0.000)changed significantly after treatment.Similar changes were observed in the remission group(n=29).Multiple linear regression revealed that the only factors influencing treatment effect were symptom characteristics,SVA,and VAS score.CONCLUSION:SM relieved pain and improved sagittal imbalance in patients with degenerative scoliosis.It did not lessen the severity of coronal curvature or vertebral rotation.Factors influencing the effect of SM included symptom characteristics,VAS score,and SVA.A larger randomized trial is needed to further confirm our results.展开更多
Flowering at the most appropriate times of the year requires careful monitoring of environmental conditions and correct integration of such information with an endogenous molecular network. Rice （Oryza sativa） is a ...Flowering at the most appropriate times of the year requires careful monitoring of environmental conditions and correct integration of such information with an endogenous molecular network. Rice （Oryza sativa） is a facultative short day plant, and flowers quickly under short day lengths, as opposed to Arabidopsis thaliana whose flowering is accelerated by longer days. Despite these physiological differences, several genes controlling flowering in response to day length （or photoperiod） are conserved between rice and Arabidopsis, and the molecular mechanisms involved are similar. Inductive day lengths trigger expression of florigenic proteins in leaves that can move to the shoot apical meristem to induce reproductivedevelopment. As compared to Arabidopsis, rice also possesses unique factors that regulate expression of florigenic genes. Here, we discuss recent advances in understanding the molecular mechanisms involved in day length perception, production of florigenic signals, and molecular responses of the shoot apical meristem to florigenic proteins.展开更多
The optimal plane for measurement of the right ventricular (RV) volumes by real-time three-dimensional echocardiography (RT3DE) was determined and the feasibility and accuracy of RT3DE in studying RV systolic function...The optimal plane for measurement of the right ventricular (RV) volumes by real-time three-dimensional echocardiography (RT3DE) was determined and the feasibility and accuracy of RT3DE in studying RV systolic function was assessed. RV “Full volume” images were acquired by RT3DE in 22 healthy subjects. RV end-diastolic volumes (RVEDV) and end-systolic volumes (RVESV) were outlined using apical biplane, 4-plane, 8-plane, 16-plane offline separately. RVSV and RVEF were calculated. Meanwhile tricuspid annual systolic excursion (TASE) was measured by M-mode echo. LVSV was outlined by 2-D echo according to the biplane Simpson's rule. The results showed: (1) There was a good correlation between RVSV measured from series planes and LVSV from 2-D echo (r=0.73; r=0.69; r=0.63; r=0.66, P<0.25—0.0025); (2) There were significant differences between RVEDV in biplane and those in 4-, 8-, 16-plane (P<0.001). There was also difference between RV volume in 4-plane and that in 8-plane (P<0.05), but there was no significant difference between RV volume in 8-plane and that in 16-plane (P>0.05); (3) Inter-observers and intro-observers variability analysis showed that there were close agreements and relations for RV volumes (r=0.986, P<0.001; r=0.93, P<0.001); (4) There was a significantly positive correlation of TASE to RVSV and RVEF from RT3DE (r=0.83; r=0.90). So RV volume measures with RT3DE are rapid, accurate and reproducible. In view of RV's complex shape, apical 8-plane method is better in clinical use. It may allow early detection of RV systolic function.展开更多
A subtracted cDNA library of rice (Oryza sativa L.) inflorescence meristem (IM) was constructed using the suppression subtractive hybridization (SSH) method. The cDNAs of the rice shoot apical meristem (SAM) were used...A subtracted cDNA library of rice (Oryza sativa L.) inflorescence meristem (IM) was constructed using the suppression subtractive hybridization (SSH) method. The cDNAs of the rice shoot apical meristem (SAM) were used as 'driver' and inflorescence meristem (IM) as 'tester' in the experiment, respectively. Forty of 250 randomly chosen cDNA clones were identified by differential screening, which were IM-specific or IM-highly expressed. Most of the rice IM cDNAs cloned by SSH appear to represent rare transcripts, 40% of which were derived from truly differentially expressed genes. Of all the forty sequenced cDNA inserts, eleven contain the regions with 60%-90% identity to their homolog in GenBank, eighteen are expected to be new genes, only two correspond to published rice genes.展开更多
Cotton(Gossypium spp.)is one of the most important fiber crops worldwide.In the last two decades,transgenesis and genome editing have played important roles in cotton improvement.However,genotype dependence is one of ...Cotton(Gossypium spp.)is one of the most important fiber crops worldwide.In the last two decades,transgenesis and genome editing have played important roles in cotton improvement.However,genotype dependence is one of the key bottlenecks in generating transgenic and gene-edited cotton plants through either particle bombardment or Agrobacterium-mediated transformation.Here,we developed a shoot apical meristem(SAM)cell-mediated transformation system(SAMT)that allowed the transformation of recalcitrant cotton genotypes including widely grown upland cotton(Gossypium hirsutum),Sea island cotton(Gossypium barbadense),and Asiatic cotton(Gossypium arboreum).Through SAMT,we successfully introduced two foreign genes,GFP and RUBY,into SAM cells of some recalcitrant cotton genotypes.Within 2–3 months,transgenic adventitious shoots generated from the axillary meristem zone could be recovered and grown into whole cotton plants.The GFP fluorescent signal and betalain accumulation could be observed in various tissues in GFP-and RUBY-positive plants,as well as in their progenies,indicating that the transgenes were stably integrated into the genome and transmitted to the next generation.Furthermore,using SAMT,we successfully generated edited cotton plants with inheritable targeted mutagenesis in the GhPGF and GhRCD1 genes through CRISPR/Cas9-mediated genome editing.In summary,the established SAMT transformation system here in this study bypasses the embryogenesis process during tissue culture in a conventional transformation procedure and significantly accelerates the generation of transgenic and gene-edited plants for genetic improvement of recalcitrant cotton varieties.展开更多
AIM: To review the initial presentation and demonstrate the importance of Takotsubo cardiomyopathy. METHODS: A PubMed search using the terms "Takotsubo cardiomyopathy (TC)" and "apical ballooning syndro...AIM: To review the initial presentation and demonstrate the importance of Takotsubo cardiomyopathy. METHODS: A PubMed search using the terms "Takotsubo cardiomyopathy (TC)" and "apical ballooning syndrome" yield 211 publications. Only those that were relevant were fully reviewed. The gender, age, precipitating stressor, main complaint at presentation, electrocardiogram (ECG) at admission and serum cardiac markers of patients diagnosed with TC, were extracted as available. The data were organized in tables and graphics, and the incidence of the disorder was calculated and analyzed. RESULTS: A total of 250 clinical cases were examined. The predominant gender that was affected was female, with a prevalence of 87.5%. The mean age of presentation was 64±14 years. The cases were divided by age into 10-year intervals. The age interval of 60-69 years showed the highest frequency of TC, accounting for 79 cases. The most common precipitating stressor was physical (50% of cases). Chest pain wasthe primary complaint at presentation (58.8% of cases) followed by dyspnea (30% of cases). The ST segment changes category was the most common (60%), followed by T wave changes (39.6%). Of the 60% of cases with ST segment changes, 12% had concomitant T wave changes. This means that for 27.6% of the cases, the primary abnormality in the ECG was T wave changes; 87.6% of cases with TC had a change in the ST segment, in the T wave or in both. The percentage of ECGs presenting with changes in the anterior wall was 54.4% (35.6% of ST segment elevation +1.6% of ST segment depression +17.2% of T wave inversion). The percentage of patients presenting with changes in the lateral segment of the heart was 46.8%, while the percentage of patients with changes in the inferior heart was 21.6% and the percentage of patients with changes in the apical region was only 16%. The prevalence of elevated creatinine kinase and/or troponin on initial presentation was 89.3%. CONCLUSION: It is essential that every physician consider Takotsubo cardiomyopathy as 展开更多
AIM:To assess whether glutamate plays a similar role to glutamine in preserving gut wall integrity.METHODS:The effects of glutamine and glutamate on induced hyperpermeability in intestinal cell lines were studied.Para...AIM:To assess whether glutamate plays a similar role to glutamine in preserving gut wall integrity.METHODS:The effects of glutamine and glutamate on induced hyperpermeability in intestinal cell lines were studied.Paracellular hyperpermeability was induced in Caco2.BBE and HT-29CL.19A cell lines by adding phorbol-12,13-dibutyrate(PDB) apically,after which the effects of glutamine and glutamate on horseradish peroxidase(HRP) diffusion were studied.An inhibitor of glutamate transport(L-trans-pyrrolidine-2,4-dicarboxylic acid:trans-PDC) and an irreversible blocker(acivicin) of the extracellular glutamine to glutamate converting enzyme,γ-glutamyltransferase,were used.RESULTS:Apical to basolateral HRP flux increased significantly compared to controls not exposed to PDB (n=30,P<0.001).Glutamine application reduced hyperpermeability by 19%and 39%in the respective cell lines.Glutamate application reduced hyperpermeability by 30%and 20%,respectively.Incubation of HT29CL.19A cells with acivicin and subsequent PDB and glutamine addition increased permeability levels.Incubation of Caco2.BBE cells with trans-PDC followed by PDB and glutamate addition also resulted in high permeability levels.CONCLUSION:Apical glutamate-similar to glutaminecan decrease induced paracellular hyperpermeability.Extracellular conversion of glutamine to glutamate and subsequent uptake of glutamate could be a pivotal step in the mechanism underlying the protective effect of glutamine.展开更多
AIM To explore regional systolic strain of midwall and endocardial segments using speckle tracking echocardiography in patients with apical hypertrophic cardiomyopathy(HCM).METHODS We prospectively assessed 20 patient...AIM To explore regional systolic strain of midwall and endocardial segments using speckle tracking echocardiography in patients with apical hypertrophic cardiomyopathy(HCM).METHODS We prospectively assessed 20 patients(mean age 53 ± 16 years,range:18-81 years,10 were male),with apical HCM. We measured global longitudinal peak systolic strain(GLPSS) in the midwall and endocardium of the left ventricle. RESULTS The diastolic thickness of the 4 apical segments was 16.25 ± 2.75 mm. All patients had a normal global systolicfunction with a fractional shortening of 50% ± 8%. In spite of supernormal left ventricular(LV) systolic function,midwall GLPSS was decreased in all patients,more in the apical(-7.3% ±-8.8%) than in basal segments(-15.5% ±-6.93%),while endocardial GLPPS was significantly greater and reached normal values(apical:-22.8% ±-7.8%,basal:-17.9% ±-7.5%). CONCLUSION This study shows that two-dimensional strain was decreased mainly confined to the mesocardium,while endocardium myocardial deformation was preserved in HCM and allowed to identify subclinical LV dysfunction. This transmural heterogeneity in systolic strain had not been previously described in HCM and could be explained by the distribution of myofibrillar disarray in deep myocardial areas. The clinical application of this novel finding may help further understanding of the pathophysiology of HCM.展开更多
Polarized tip growth is a fundamental cellular process in many eukaryotes. In this study, we examined the dynamic restructuring of the actin cytoskeleton and its relationship to vesicle transport during pollen tip gro...Polarized tip growth is a fundamental cellular process in many eukaryotes. In this study, we examined the dynamic restructuring of the actin cytoskeleton and its relationship to vesicle transport during pollen tip growth in Arabidopsis. We found that actin filaments originating from the apical membrane form a specialized structure consisting of longitudinally aligned actin bundles at the cortex and inner cytoplasmic fila- ments with a distinct distribution. Using actin-based pharmacological treatments and genetic mutants in combination with FRAP （fluorescence recovery after photobleaching） technology to visualize the transport of vesicles within the growth domain of pollen tubes, we demonstrated that cortical actin filaments facilitate tip-ward vesicle transport. We also discovered that the inner apical actin filaments prevent backward movement of vesicles, thus ensuring that sufficient vesicles accumulate at the pollen tube tip to support the rapid growth of the pollen tube. The combinatorial effect of cortical and internal apical actin filaments perfectly explains the generation of the inverted ＂V＂ cone-shaped vesicle distribution pattern at the pollen tube tip. When pollen tubes turn, apical actin filaments at the facing side undergo depolymerization and repolymerization to reorient the apical actin structure toward the new growth direction. This actin restructuring precedes vesicle accumulation and changes in tube morphology. Thus, our study provides new insights into the functional relationship between actin dynamics and vesicle transport during rapid and directional pollen tube growth.展开更多
The Arabidopsis XBAT35 is one of five structurally related ankyrin repeat-containing Really Interesting New Gene （RING） E3 ligases involved in ubiquitin-mediated protein degradation, which plays key roles in a wide ...The Arabidopsis XBAT35 is one of five structurally related ankyrin repeat-containing Really Interesting New Gene （RING） E3 ligases involved in ubiquitin-mediated protein degradation, which plays key roles in a wide range of cel- lular processes. Here, we show that the XBAT35 gene undergoes alternative splicing, generating two transcripts that are constitutively expressed in all plant tissues. The two splice variants derive from an exon skipping event that excludes an in-frame segment from the XBAT35 precursor mRNA, giving rise to two protein isoforms that differ solely in the presence of a nuclear localization signal （NLS）. Transient expression assays indicate that the isoform lacking the NLS localizes in the cytoplasm of plant cells, whereas the other is targeted to the nucleus, accumulating in nuclear speckles. Both isoforms are functional E3 ligases, as assessed by in vitro ubiquitination assays. Two insertion mutant alleles and RNA-interference （RNAi） silencing lines for XBAT35 display no evident phenotypes under normal growth conditions, but exhibit hyper- sensitivity to the ethylene precursor 1-aminocyclopropane-l-carboxylate （ACC） during apical hook exaggeration in the dark, which is rescued by an inhibitor of ethylene perception. Independent expression of each XBAT35 splice variant in the mutant background indicates that the two isoforms may differentially contribute to apical hook formation but are both functional in this ethylene-mediated response. Thus, XBAT35 defines a novel player in ethylene signaling involved in negatively regulating apical hook curvature, with alternative splicing controlling dual targeting of this E3 ubiquitin ligase to the nuclear and cytoplasmic compartments.展开更多
During plant development, the frequency and context of cell division must be controlled, and cells must differentiate properly to perform their mature functions. In addition, stem cell niches need to be maintained as ...During plant development, the frequency and context of cell division must be controlled, and cells must differentiate properly to perform their mature functions. In addition, stem cell niches need to be maintained as a reservoir for new cells. All of these processes require intercellular signaling, whether it is a cell relaying its position to other cells, or more mature cells signaling to the stem cell niche to regulate the rate of growth. Receptor-like kinases have emerged as a major component in these diverse roles, especially within the Arabidopsis root. In this review, the functions of receptor-like kinase signaling in regulating Arabidopsis root development will be examined in theareas of root apical meristem maintenance, regulation of epidermal cell fate, lateral root development and vascular differentiation.展开更多
基金Natural Science Foundation of China grants，by the CAS International Partnership Program for Creative Research Teams
文摘Angiosperm seeds usually consist of two major parts： the embryo and the endosperm. However, the molec- ular mechanism（s） underlying embryo and endosperm development remains largely unknown, particularly in rice, the model cereal. Here, we report the identification and functional characterization of the rice GIANT EMBRYO （GE） gene. Mutation of GE resulted in a large embryo in the seed, which was caused by excessive expansion of scuteUum cells. Post-embryonic growth of ge seedling was severely inhibited due to defective shoot apical meristem （SAM） mainte- nance. Map-based cloning revealed that GE encodes a CYP78A subfamily P450 monooxygenase that is localized to the endoplasmic reticulum. GE is expressed predominantly in the scutellar epithelium, the interface region between embryo and endosperm. Overexpression of GE promoted cell proliferation and enhanced rice plant growth and grain yield, but reduced embryo size, suggesting that GE is critical for coordinating rice embryo and endosperm development. Moreover, transgenic Arabidopsis plants overexpressing AtCYP78AlO, a GE homolog, also produced bigger seeds, implying a con- served role for the CYP78A subfamily of P450s in regulating seed development. Taken together, our results indicate that GE plays critical roles in regulating embryo development and SAM maintenance.
基金Supported by The research grants from Shanghai Municipal Science and Technology CommissionNo.114119b2900+1 种基金Shanghai Municipal Key Laboratory of Pancreatic DiseaseNo.P2012006
文摘AIM:To investigate whether miRNA-155(miR-155)dysregulates apical junctional complex(AJC)protein expression in experimental severe acute pancreatitis(SAP).METHODS:Twenty-four male BALB/c mice were randomly assigned to two groups:the SAP group(n=12)receiving sequential intraperitoneal injection of 50μg/kg caerulein and 10 mg/kg lipopolysaccharide over 6h,and the control group(n=12)receiving intraperitoneal injection of normal saline.Animals were sacrificed3 h following the last injection for collection of blood samples and pancreas and distal ileal segment specimens.Routine pancreas and intestine histology was used to assess SAP pathology and intestinal epithelial barrier damage.Levels of serum amylase,diamine oxidase(DAO),and tumor necrosis factor(TNF)-αwere determined using commercial kits.Total RNA samples were isolated from intestinal epithelial specimens and reversely transcribed into cDNA.miR-155 and RhoA mRNA expression profiles were determined using quantitative real-time polymerase chain reaction.Target genes for miR-155 were predicted using the miRTarBase database,RNA22 and PicTar computational methods.Western blotting was performed to quantitate the protein expression levels of the target gene RhoA,as well as zonula occludens(ZO)-1 and E-cadherin,two AJC component proteins.RESULTS:Intraperitoneal injection of caerulein and lipopolysaccharide successfully induced experimental acute pancreatic damage(SAP vs control,10.0±2.0vs 3.2±1.2,P<0.01)and intestinal epithelial barrier damage(3.2±0.7 vs 1.4±0.7,P<0.01).Levels of serum amylase(21.6±5.1 U/mL vs 14.3±4.2 U/mL,P<0.01),DAO(21.4±4.1 mg/mL vs 2.6±0.8 mg/mL,P<0.01),and TNF-α(61.0±15.1 ng/mL vs 42.9±13.9 ng/mL,P<0.01)increased significantly in SAP mice compared to those in control mice.miR-155 was significantly overexpressed in SAP intestinal epithelia(1.94±0.50 fold vs 1.03±0.23 fold,P<0.01),and RhoA gene containing three miR-155-specific binding sites in the three prime untranslated regions was one of the target genes for miR-155.RhoA(22.7±5.
基金supported by the National Natural Science Foundation of China(Grant Nos. 30840091 and 81000428)
文摘To investigate the prevalence of Enterococcus faecalis in saliva and filled root canals of patients requiring endodontic retreatment for apical periodontitis.Patients with apical periodontitis who were referred for endodontic retreatment were examined.The type and quality of the restoration,symptoms,quality of obturation were recorded.During retreatment,an oral rinse sample and root canal sample were cultured using brain-heart infusion agar and bile esculinazide agar to select for E.faecalis.The 16S rRNA technique was used to identify E.faecalis.A total of 32 women and 22 men（mean age：38 years;s.d.：11 years） and 58 teeth were studied.The prevalence of E.faecalis was 19% in the saliva and 38% in the root canals.The odds that root canals harbored E.faecalis were increased if the saliva habored this bacterium（odds ratio59.7;95% confidence interval51.8-51.6;P,0.05）.Teeth with unsatisfactory root obturation had more cultivable bacterial species in root canals than teeth with satisfactory root obturation（P,0.05）.E.faecalis is more common in root canals of teeth with apical periodontitis than in saliva.The prevalence of E.faecalis in root canals is associated with the presence of E.faecalis in saliva.
基金Acknowledgments The authors thank Dr Liying Du （Peking University, China） for technical help on the flow cytometric analysis. The authors also thank Dr Zhongchi Liu （University of Maryland, USA）, Dr Chun-Ming Liu （Institute of Botany CAS, China）, Dr Terry Matthew （University of Southampton, UK）, Professor Daochun Kong （Peking University, China） and Dr Naomi Nakayama （Yale University, USA） for critical comments and valuable discussion. This work was supported by the National Natural Science Foundation of China （GN 30625002 to L-J Qu）.
文摘As a cell cycle regulator, the Myb-related CDC5 protein was reported to be essential for the G2 phase of the cell cycle in yeast and animals, but little is known about its function in plants. Here we report the functional characterization of the CDC5 gene in Arabidopsis thaliana. Arabidopsis CDC5 （AtCDC5） is mainly expressed in tissues with high cell division activity, and is expressed throughout the entire process of embryo formation. The AtCDC5 loss-of-function mutant is embryonic lethal. In order to investigate the function of AtCDC5 in vivo, we generated AtCDC5-RNAi plants in which the expression of AtCDC5 was reduced by RNA interference. We found that the G2 to M （G2/M） phase transition was affected in the AtCDC5-RNAi plants, and that endoreduplication was increased. Additionally, the maintenance of shoot apical meristem （SAM） function was disturbed in the AtCDC5-RNAi plants, in which both the WUSCHEL （WUS）- CLAVATA （CLV） and the SHOOT MERISTEMLESS （STM） pathways were impaired. In situ hybridization analysis showed that the expression of STMwas greatly reduced in the shoot apical cells of the AtCDC5-RNAi plants. Moreover, cyclinB1 or Histone4 was found to be expressed in some of these cells when the transcript of STM was undetectable. These results suggest that AtCDC5 is essential for the G2/M phase transition and may regulate the function of SAM by controlling the expression ofSTMand WUS.
文摘Apical hypertrophic cardiomyopathy(AHCM) is a relatively rare morphologic variant of HCM in which the hypertrophy of myocardium is localized to the left ventricular apex. Symptoms of AHCM might vary from none to others mimic coronary artery disease including acute coronary syndrome, thus resulting in inappropriate hospitalization. Transthoracic echocardiography is the firstline imaging technique for the diagnosis of hypertrophic cardiomyopathies. However, when the hypertrophy of the myocardium is localized in the ventricular apex might results in missed diagnosis. Aim of this paper is to review the different imaging techniques used for the diagnosis of AHCM and their role in the detection and comprehension of this uncommon disease.
基金Supported by the Special Subject for the Construction of the National Traditional Chinese Medicine Clinical Research Base Effect of Spinal Manipulation on Degenerative Scoliosis and Factors Influencing Treatment Effect(JDZX2015271)Basic Scientific Research Project of Chinese Academy of Traditional Chinese Medicine Clinical and Experimental Study on Delaying The Degeneration of Bone and Joint(ZZ10-022)。
文摘OBJECTIVE:To investigate the effect of spinal manipulation(SM)on degenerative scoliosis by evaluating patients’visual analog scale(VAS)scores,Cobb angles,sagittal vertical axis(SVA),and apical vertebral rotation(AVR)and to explore factors that influence treatment effect.METHODS:A total of 55 patients with degenerative scoliosis received 4 weeks of SM.After treatment,patients were divided into two groups:the remission group(VAS score<40 mm)and the non-remission group(VAS score≥40 mm).Pre-versus post-treatment VAS scores,Cobb angles,SVA,and AVR were compared in each group and in the total population.Baseline data(sex,age,symptom characteristics,duration of symptoms,VAS score,Cobb angle,SVA,and AVR)were compared between groups.Factors influencing the post-treatment VAS score were explored with multiple linear regression analysis.RESULTS:No changes were found in the Cobb angle(P=0.722)or AVR(P=0.424)after intervention in the overall population.However,the SVA(P<0.001)and VAS score(P=0.000)changed significantly after treatment.Similar changes were observed in the remission group(n=29).Multiple linear regression revealed that the only factors influencing treatment effect were symptom characteristics,SVA,and VAS score.CONCLUSION:SM relieved pain and improved sagittal imbalance in patients with degenerative scoliosis.It did not lessen the severity of coronal curvature or vertebral rotation.Factors influencing the effect of SM included symptom characteristics,VAS score,and SVA.A larger randomized trial is needed to further confirm our results.
基金supported by an ERC Starting Grant(No.260963) to F.F
文摘Flowering at the most appropriate times of the year requires careful monitoring of environmental conditions and correct integration of such information with an endogenous molecular network. Rice （Oryza sativa） is a facultative short day plant, and flowers quickly under short day lengths, as opposed to Arabidopsis thaliana whose flowering is accelerated by longer days. Despite these physiological differences, several genes controlling flowering in response to day length （or photoperiod） are conserved between rice and Arabidopsis, and the molecular mechanisms involved are similar. Inductive day lengths trigger expression of florigenic proteins in leaves that can move to the shoot apical meristem to induce reproductivedevelopment. As compared to Arabidopsis, rice also possesses unique factors that regulate expression of florigenic genes. Here, we discuss recent advances in understanding the molecular mechanisms involved in day length perception, production of florigenic signals, and molecular responses of the shoot apical meristem to florigenic proteins.
文摘The optimal plane for measurement of the right ventricular (RV) volumes by real-time three-dimensional echocardiography (RT3DE) was determined and the feasibility and accuracy of RT3DE in studying RV systolic function was assessed. RV “Full volume” images were acquired by RT3DE in 22 healthy subjects. RV end-diastolic volumes (RVEDV) and end-systolic volumes (RVESV) were outlined using apical biplane, 4-plane, 8-plane, 16-plane offline separately. RVSV and RVEF were calculated. Meanwhile tricuspid annual systolic excursion (TASE) was measured by M-mode echo. LVSV was outlined by 2-D echo according to the biplane Simpson's rule. The results showed: (1) There was a good correlation between RVSV measured from series planes and LVSV from 2-D echo (r=0.73; r=0.69; r=0.63; r=0.66, P<0.25—0.0025); (2) There were significant differences between RVEDV in biplane and those in 4-, 8-, 16-plane (P<0.001). There was also difference between RV volume in 4-plane and that in 8-plane (P<0.05), but there was no significant difference between RV volume in 8-plane and that in 16-plane (P>0.05); (3) Inter-observers and intro-observers variability analysis showed that there were close agreements and relations for RV volumes (r=0.986, P<0.001; r=0.93, P<0.001); (4) There was a significantly positive correlation of TASE to RVSV and RVEF from RT3DE (r=0.83; r=0.90). So RV volume measures with RT3DE are rapid, accurate and reproducible. In view of RV's complex shape, apical 8-plane method is better in clinical use. It may allow early detection of RV systolic function.
基金the National Natural Science Foundation of China (Grant No. 39770047).
文摘A subtracted cDNA library of rice (Oryza sativa L.) inflorescence meristem (IM) was constructed using the suppression subtractive hybridization (SSH) method. The cDNAs of the rice shoot apical meristem (SAM) were used as 'driver' and inflorescence meristem (IM) as 'tester' in the experiment, respectively. Forty of 250 randomly chosen cDNA clones were identified by differential screening, which were IM-specific or IM-highly expressed. Most of the rice IM cDNAs cloned by SSH appear to represent rare transcripts, 40% of which were derived from truly differentially expressed genes. Of all the forty sequenced cDNA inserts, eleven contain the regions with 60%-90% identity to their homolog in GenBank, eighteen are expected to be new genes, only two correspond to published rice genes.
基金supported by the National Science Foundation of China(Grant Nos.31621005,31701476,32171996)the Hainan Yazhou Bay Seed Laboratory(Grant Nos.B21HJ0207 and B21HJ0215)+1 种基金the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciencesthe China Agriculture Research System of MOF and MARA(Grant No.CARS-15-02)。
文摘Cotton(Gossypium spp.)is one of the most important fiber crops worldwide.In the last two decades,transgenesis and genome editing have played important roles in cotton improvement.However,genotype dependence is one of the key bottlenecks in generating transgenic and gene-edited cotton plants through either particle bombardment or Agrobacterium-mediated transformation.Here,we developed a shoot apical meristem(SAM)cell-mediated transformation system(SAMT)that allowed the transformation of recalcitrant cotton genotypes including widely grown upland cotton(Gossypium hirsutum),Sea island cotton(Gossypium barbadense),and Asiatic cotton(Gossypium arboreum).Through SAMT,we successfully introduced two foreign genes,GFP and RUBY,into SAM cells of some recalcitrant cotton genotypes.Within 2–3 months,transgenic adventitious shoots generated from the axillary meristem zone could be recovered and grown into whole cotton plants.The GFP fluorescent signal and betalain accumulation could be observed in various tissues in GFP-and RUBY-positive plants,as well as in their progenies,indicating that the transgenes were stably integrated into the genome and transmitted to the next generation.Furthermore,using SAMT,we successfully generated edited cotton plants with inheritable targeted mutagenesis in the GhPGF and GhRCD1 genes through CRISPR/Cas9-mediated genome editing.In summary,the established SAMT transformation system here in this study bypasses the embryogenesis process during tissue culture in a conventional transformation procedure and significantly accelerates the generation of transgenic and gene-edited plants for genetic improvement of recalcitrant cotton varieties.
文摘AIM: To review the initial presentation and demonstrate the importance of Takotsubo cardiomyopathy. METHODS: A PubMed search using the terms "Takotsubo cardiomyopathy (TC)" and "apical ballooning syndrome" yield 211 publications. Only those that were relevant were fully reviewed. The gender, age, precipitating stressor, main complaint at presentation, electrocardiogram (ECG) at admission and serum cardiac markers of patients diagnosed with TC, were extracted as available. The data were organized in tables and graphics, and the incidence of the disorder was calculated and analyzed. RESULTS: A total of 250 clinical cases were examined. The predominant gender that was affected was female, with a prevalence of 87.5%. The mean age of presentation was 64±14 years. The cases were divided by age into 10-year intervals. The age interval of 60-69 years showed the highest frequency of TC, accounting for 79 cases. The most common precipitating stressor was physical (50% of cases). Chest pain wasthe primary complaint at presentation (58.8% of cases) followed by dyspnea (30% of cases). The ST segment changes category was the most common (60%), followed by T wave changes (39.6%). Of the 60% of cases with ST segment changes, 12% had concomitant T wave changes. This means that for 27.6% of the cases, the primary abnormality in the ECG was T wave changes; 87.6% of cases with TC had a change in the ST segment, in the T wave or in both. The percentage of ECGs presenting with changes in the anterior wall was 54.4% (35.6% of ST segment elevation +1.6% of ST segment depression +17.2% of T wave inversion). The percentage of patients presenting with changes in the lateral segment of the heart was 46.8%, while the percentage of patients with changes in the inferior heart was 21.6% and the percentage of patients with changes in the apical region was only 16%. The prevalence of elevated creatinine kinase and/or troponin on initial presentation was 89.3%. CONCLUSION: It is essential that every physician consider Takotsubo cardiomyopathy as
基金Supported by VU University Medical Center,Amsterdam,The Netherlands
文摘AIM:To assess whether glutamate plays a similar role to glutamine in preserving gut wall integrity.METHODS:The effects of glutamine and glutamate on induced hyperpermeability in intestinal cell lines were studied.Paracellular hyperpermeability was induced in Caco2.BBE and HT-29CL.19A cell lines by adding phorbol-12,13-dibutyrate(PDB) apically,after which the effects of glutamine and glutamate on horseradish peroxidase(HRP) diffusion were studied.An inhibitor of glutamate transport(L-trans-pyrrolidine-2,4-dicarboxylic acid:trans-PDC) and an irreversible blocker(acivicin) of the extracellular glutamine to glutamate converting enzyme,γ-glutamyltransferase,were used.RESULTS:Apical to basolateral HRP flux increased significantly compared to controls not exposed to PDB (n=30,P<0.001).Glutamine application reduced hyperpermeability by 19%and 39%in the respective cell lines.Glutamate application reduced hyperpermeability by 30%and 20%,respectively.Incubation of HT29CL.19A cells with acivicin and subsequent PDB and glutamine addition increased permeability levels.Incubation of Caco2.BBE cells with trans-PDC followed by PDB and glutamate addition also resulted in high permeability levels.CONCLUSION:Apical glutamate-similar to glutaminecan decrease induced paracellular hyperpermeability.Extracellular conversion of glutamine to glutamate and subsequent uptake of glutamate could be a pivotal step in the mechanism underlying the protective effect of glutamine.
文摘AIM To explore regional systolic strain of midwall and endocardial segments using speckle tracking echocardiography in patients with apical hypertrophic cardiomyopathy(HCM).METHODS We prospectively assessed 20 patients(mean age 53 ± 16 years,range:18-81 years,10 were male),with apical HCM. We measured global longitudinal peak systolic strain(GLPSS) in the midwall and endocardium of the left ventricle. RESULTS The diastolic thickness of the 4 apical segments was 16.25 ± 2.75 mm. All patients had a normal global systolicfunction with a fractional shortening of 50% ± 8%. In spite of supernormal left ventricular(LV) systolic function,midwall GLPSS was decreased in all patients,more in the apical(-7.3% ±-8.8%) than in basal segments(-15.5% ±-6.93%),while endocardial GLPPS was significantly greater and reached normal values(apical:-22.8% ±-7.8%,basal:-17.9% ±-7.5%). CONCLUSION This study shows that two-dimensional strain was decreased mainly confined to the mesocardium,while endocardium myocardial deformation was preserved in HCM and allowed to identify subclinical LV dysfunction. This transmural heterogeneity in systolic strain had not been previously described in HCM and could be explained by the distribution of myofibrillar disarray in deep myocardial areas. The clinical application of this novel finding may help further understanding of the pathophysiology of HCM.
基金This work was supported by grants from the Ministry of Science and Technology of China （2013CB945100） and the National Natural Science Foundation of China （31671390 and 31471266）. X.Q. was supported by post-doctoral fellowships from Tsinghua-Peking Joint Center for Life Sciences and the China Postdoctoral Science Foundation （grant no. 2015M571028）.
文摘Polarized tip growth is a fundamental cellular process in many eukaryotes. In this study, we examined the dynamic restructuring of the actin cytoskeleton and its relationship to vesicle transport during pollen tip growth in Arabidopsis. We found that actin filaments originating from the apical membrane form a specialized structure consisting of longitudinally aligned actin bundles at the cortex and inner cytoplasmic fila- ments with a distinct distribution. Using actin-based pharmacological treatments and genetic mutants in combination with FRAP （fluorescence recovery after photobleaching） technology to visualize the transport of vesicles within the growth domain of pollen tubes, we demonstrated that cortical actin filaments facilitate tip-ward vesicle transport. We also discovered that the inner apical actin filaments prevent backward movement of vesicles, thus ensuring that sufficient vesicles accumulate at the pollen tube tip to support the rapid growth of the pollen tube. The combinatorial effect of cortical and internal apical actin filaments perfectly explains the generation of the inverted ＂V＂ cone-shaped vesicle distribution pattern at the pollen tube tip. When pollen tubes turn, apical actin filaments at the facing side undergo depolymerization and repolymerization to reorient the apical actin structure toward the new growth direction. This actin restructuring precedes vesicle accumulation and changes in tube morphology. Thus, our study provides new insights into the functional relationship between actin dynamics and vesicle transport during rapid and directional pollen tube growth.
文摘The Arabidopsis XBAT35 is one of five structurally related ankyrin repeat-containing Really Interesting New Gene （RING） E3 ligases involved in ubiquitin-mediated protein degradation, which plays key roles in a wide range of cel- lular processes. Here, we show that the XBAT35 gene undergoes alternative splicing, generating two transcripts that are constitutively expressed in all plant tissues. The two splice variants derive from an exon skipping event that excludes an in-frame segment from the XBAT35 precursor mRNA, giving rise to two protein isoforms that differ solely in the presence of a nuclear localization signal （NLS）. Transient expression assays indicate that the isoform lacking the NLS localizes in the cytoplasm of plant cells, whereas the other is targeted to the nucleus, accumulating in nuclear speckles. Both isoforms are functional E3 ligases, as assessed by in vitro ubiquitination assays. Two insertion mutant alleles and RNA-interference （RNAi） silencing lines for XBAT35 display no evident phenotypes under normal growth conditions, but exhibit hyper- sensitivity to the ethylene precursor 1-aminocyclopropane-l-carboxylate （ACC） during apical hook exaggeration in the dark, which is rescued by an inhibitor of ethylene perception. Independent expression of each XBAT35 splice variant in the mutant background indicates that the two isoforms may differentially contribute to apical hook formation but are both functional in this ethylene-mediated response. Thus, XBAT35 defines a novel player in ethylene signaling involved in negatively regulating apical hook curvature, with alternative splicing controlling dual targeting of this E3 ubiquitin ligase to the nuclear and cytoplasmic compartments.
文摘During plant development, the frequency and context of cell division must be controlled, and cells must differentiate properly to perform their mature functions. In addition, stem cell niches need to be maintained as a reservoir for new cells. All of these processes require intercellular signaling, whether it is a cell relaying its position to other cells, or more mature cells signaling to the stem cell niche to regulate the rate of growth. Receptor-like kinases have emerged as a major component in these diverse roles, especially within the Arabidopsis root. In this review, the functions of receptor-like kinase signaling in regulating Arabidopsis root development will be examined in theareas of root apical meristem maintenance, regulation of epidermal cell fate, lateral root development and vascular differentiation.
