Radiation hybrid QTL mapping of Tdes2 involved in the first meiotic division of wheat

Since the dawn of wheat cytogenetics, chromosome 3B has been known to harbor a gene(s) that, when removed, causes chromosome desynapsis and gametic sterility. The lack of natural genetic diversity for this gene(s) has prevented any attempt to fine map and further characterize it. Here, gamma radiation treatment was used to create artificial diversity for this locus. A total of 696 radiation hybrid lines were genotyped with a custom mini array of 140 DArT markers, selected to evenly span the whole 3B chromosome. The resulting map spanned 2,852 centi Ray with a calculated resolution of 0.384 Mb. Phenotyping for the occurrence of meiotic desynapsis was conducted by measuring the level of gametic sterility as seeds produced per spikelet and pollen viability at booting. Composite interval mapping revealed a single QTL with LOD of 16.2 and r (2) of 25.6 % between markers wmc326 and wPt-8983 on the long arm of chromosome 3B. By independent analysis, the location of the QTL was confirmed to be within the deletion bin 3BL7-0.63-1.00 and to correspond to a single gene located ~1.4 Mb away from wPt-8983. The meiotic behavior of lines lacking this gene was characterized cytogenetically to reveal striking similarities with mutants for the dy locus, located on the syntenic chromosome 3 of maize. This represents the first example to date of employing radiation hybrids for QTL analysis. The success achieved by this approach provides an ideal starting point for the final cloning of this interesting gene involved in meiosis of cereals.

Upregulated Hoxc6 expression is associated with poor survival in gastric cancer patients

Human Hox genes (Homeobox) have crucial roles in development and differentiation, regulating numerous processes including apoptosis, receptor signalling, differentiation, motility and angiogenesis. Aberrant expression of Hoxc6 gene has been reported in several tumor tissues and cancer cell lines. The prognostic significance of Hoxc6 in gastric cancer remains largely unknown.This study was aimed to investigate the clinical significance of Hoxc6 in gastric cancer.Total RNA of paired tissue samples (n=25) and a tissue microarray containing 161 paired tissues from patients with gastric cancers at different stages were collected. Quantitative real-time PCR and immunochemistry assay were carried out to investigate the expression of Hoxc6. Hoxc6 mRNA was increased in gastric cancer tissues ( 16 of 25) compared with the adjacent normal mucosa (P<0.05). Immunohistochemical detection showed that expression of Hoxc6 was associated with the depth of tumor invasion (P<0.05). Patients with higher expression levels of Hoxc6 had a shorter overall survival rate (P<0.05).Hoxc6 might contribute to the progression of gastric carcinogenesis and may be a significant predictor of poor survival in patients with gastric cancer after curative operations.

Development of a novel adenovirus-alphavirus hybrid vector with RNA replicon features for malignant hematopoietic cell transduction

To improve the expression levels of transgenes in malignant hematopoietic cells, we developed a novel adenoviral-alphavirus hybrid vector Ad5/F11p-SFV-GFP that contains a Semliki Forest Virus (SFV) replicon and chimeric fibers of Ad5 and Ad11p. Ad5/F11p-SFV-GFP infected >95% of K562, U937 or Jurkat cells and 23.65% of HL-60 cells, and led to moderate Enhanced Green Fluorescent Protein (EGFP) transgene expression intensity. The infection efficiency of Ad5/F11p-SFV-GFP in primary human leukemia cells ranged from 9.34-89.63% (median, 28.58%) at a multiplicity of infection (MOI) of 100, compared with only 3.37-44.54% (median, 10.42%) in cells infected by Ad5/F11p-GFP. Importantly, Ad5/F11p-SFV-GFP led to a significantly higher transgene expression level in primary leukemia cells, as indicated by the relative fluorescence intensity, compared to cells infected with Ad5/F11p-GFP. The increased expression of EGFP in Ad5/F11p-SFV-GFP-infected cells was associated with the accumulation of abundant subgenomic mRNA. Additionally, infection of K562, U937 or Jurkat cells by Ad5/F11p-SFV-GFP was significantly inhibited by blocking CD46 receptor; however, other factors may affect the gene-transfer efficiency of Ad5/F11p-SFV-GFP in primary leukemia cells. In conclusion, we successfully developed a novel adenoviral-alphavirus hybrid vector with RNA replicon features, which represents a promising vector for gene modifications during the production of cell-based vaccines for leukemia patients.

Growth factor receptor-bound protein 10-mediated negative regulation of the insulin-like growth factor-1 receptor-activated signalling pathway results in cognitive disorder in diabetic rats

Growth factor receptor-bound protein 10 (Grb10) is a Src homology 2 domain-containing protein and one of the binding partners for several transmembrane tyrosine kinase receptors, including insulin receptor (IR) and insulin-like growth factor-1 receptor (IGF1-R). The hippocampus, which is critical for cognitive functions, is one of the main distribution areas of Grb10 in the central nervous system. In recent years, diabetic encephalopathy has been defined as a third type of diabetes and the IGF1-IR pathway was shown to be critical for the neuropathogenic process of cognitive disorder in diabetes. However, the role of endogenous Grb10 in regulating the IGF1-IR pathway and neurobehavioural changes is not explicit. The present study aimed to determine the in vivo function of endogenous Grb10 in diabetic encephalopathy and the underlying mechanisms. Using stereotaxic surgical techniques and lentiviral vectors expressing specific short hairpin RNA, we could steadily knockdown Grb10 expression in the hippocampus. More importantly, we demonstrated that hippocampus-specific modulation of Grb10 protein levels led to a prominent remission of cognitive disorder, including improvements in both ultrastructural pathology and abnormal neurobehavioural changes. Our findings indicate that endogenous overexpression of Grb10 functions as a suppressor of the IGF1-IR pathway, which may represent an important mechanism for regulating cognitive disorder in diabetes.

Comparison of the safety and efficacy of conventional monopolar and 2-micron laser transurethral resection in the management of multiple nonmuscle-invasive bladder cancer

Objectives

To compare the safety and efficacy of conventional monopolar transurethral resection of bladder tumour (TURBT) and 2-micron continuous-wave laser resection (2-µm laser) techniques in the management of multiple nonmuscle-invasive bladder cancer (NMIBC), and to investigate long-term effects on tumour recurrence.

Methods

Patients with multiple NMIBC were randomized to receive TURBT or 2-µm laser in a nonblinded manner. All patients received intravesical chemotherapy with epirubicin (40 mg/40 ml) for 8 weeks, beginning 1 week after surgery, followed with monthly maintenance therapy for 12 months. Three-year follow-up data of preoperative, operative and postoperative management were recorded.

Results

In total, 120 patients were included: 56 in the TURBT group and 64 in the 2-µm laser group. Intra- and postoperative complications (including bladder perforation, bleeding and irritation) were less frequently observed in the 2-µm laser group compared with the TURBT group. There were no significant differences in first time to recurrence, overall recurrence or occurrence of urethral strictures.

Conclusions

The 2-µm laser resection method was more effective than TURBT in reducing rates of intra- and postoperative complications, but offered no additional benefit regarding tumour recurrence.

Prevalence and risk factors of asymptomatic intracranial arterial stenosis in a community-based population of Chinese adults

BACKGROUND AND PURPOSE

Intracranial arterial stenosis (ICAS) is one of the most common causes of ischaemic stroke in Asia. Knowledge of the prevalence and risk factors of asymptomatic ICAS is limited. The prevalence of ICAS was therefore investigated and its risk factors in a Chinese community-based population were explored.

METHODS

From 2010 to 2011, a stratified (by sex and age) random sample of 5440 participants aged 40 years or older were enrolled in the study. ICAS was assessed using transcranial Doppler. Logistic regression was used to evaluate potential risk factors associated with ICAS in participants.

RESULTS

In total, 13.2% (95% CI 12.3-14.1) of the subjects had ICAS, and women were more likely than men to have ICAS in the 40-49 year age group. Hypertension [odds ratio (OR) = 2.23, 95% CI 1.87-2.66], diabetes (OR = 1.99, 95% CI 1.62-2.45), left ventricular hypertrophy (OR = 1.66, 95% CI 1.18-2.34) and elevated high-sensitivity C-reactive protein (OR = 1.55, 95% CI 1.19-2.02) were independently associated with higher prevalence of ICAS after adjusting for age, gender, body mass index, smoking status and other covariates. Of the 716 ICAS individuals, 90.6% had one or more of these risk factors. Amongst the subjects who had at least one risk factor, 15.2% had ICAS.

CONCLUSIONS

Intracranial artery stenosis is common in the Chinese population. Individuals who had one or more risk factors were more likely to have ICAS, suggesting more aggressive risk factor management.

Effects of Process Conditions on the Dissolution of Carbon Dioxide in PS in Foaming Extruders

The effects of the main processing conditions on the dissolution behavior of CO2 in polystyrene melt were studied using a novel in-line method in connection with both single and twin-screw foaming extruders. Apparent solubility data obtained from the twin-screw extrusion experiments showed better consistency compared with those obtained from the single screw experiments, indicating the importance of enhanced mixing in affecting the gas dissolution and solubility behavior during an extrusion foaming process. Gas dissolution inside a twin-screw foaming extruder was further studied for CO2 in the polystyrene melt. The measured gas up-take was compared with the values calculated assuming equilibrium conditions in the gas injection zone in an effort to elucidate possible mechanisms for gas dissolution inside a foaming extruder during the actual foaming process.

Human endogenous retrovirus W family envelope gene activates the small conductance Ca2+-activated K+ channel in human neuroblastoma cells through CREB

Numerous studies have shown that human endogenous retrovirus W family (HERV-W) envelope gene (env) is related to various diseases but the underlying mechanism has remained poorly understood. Our previous study showed that there was abnormal expression of HERV-W env in sera of patients with schizophrenia. In this paper, we reported that overexpression of the HERV-W env elevated the levels of small conductance Ca(2+)-activated K(+) channel protein 3 (SK3) in human neuroblastoma cells. Using a luciferase reporter system and RNA interference method, we found that functional cAMP response element site was required for the expression of SK3 triggered by HERV-W env. In addition, it was also found that the SK3 channel was activated by HERV-W env. Further study indicated that cAMP response element-binding protein (CREB) was required for the activation of the SK3 channel. Thus, a novel signaling mechanism of how HERV-W env influences neuronal activity and contributes to mental illnesses such as schizophrenia was proposed.

Impact of basic fibroblast growth factor on healing of tympanic membrane perforations due to direct penetrating trauma: a prospective non-blinded/controlled study

OBJECTIVE

To investigate the effect of direct application of basic fibroblast growth factor (bFGF) on healing of tympanic membrane perforations due to direct traumatic penetration through the external auditory canal.

DESIGN

A prospective non-blinded controlled study.

SETTING

University-affiliated teaching hospital.

PARTICIPANTS

In total, 104 patients with small [<25%] penetrating perforations were recruited. They were alternatively allocated to two groups: Control (spontaneous healing, n = 51) and FGF treatment (direct application of bFGF drops in the clinic and repeated daily by the patient, n = 53).

OUTCOMES

Perforation closure rate and time and hearing gain were recorded and compared between the two groups. Information on earache, dizziness and facial paralysis was also collected.

RESULTS

In total, 93 (89%) patients were finally analysed. The closure rate at 3 m of the perforations in the control spontaneous healing and bFGF treatment groups were 77% and 100%, respectively; the difference was statistically significant (P = 0.01). The average closure time was 43.1 ± 2.5 days (range, 17-57 days) for control patients, which was significantly longer (P < 0.01) than that for the bFGF-treated patients (12.6 ± 1.2 days; range, 3-21 days). The mean hearing improvement at 3 m was not significantly different between the FGF treatment and control groups (1.7 ± 2.4 dB vs 11.5 ± 1.9 dB, P > 0.05). No significant difference was observed in earache, dizziness and facial paralysis between two groups.

CONCLUSIONS

Direct application of bFGF may offer an effective topical management of penetrating traumatic tympanic membrane perforations, particularly for small-sized perforations.

Comparison of different methods for imputing genome-wide marker genotypes in Swedish and Finnish Red Cattle

This study investigated the imputation accuracy of different methods, considering both the minor allele frequency and relatedness between individuals in the reference and test data sets. Two data sets from the combined population of Swedish and Finnish Red Cattle were used to test the influence of these factors on the accuracy of imputation. Data set 1 consisted of 2,931 reference bulls and 971 test bulls, and was used for validation of imputation from 3,000 markers (3K) to 54,000 markers (54K). Data set 2 contained 341 bulls in the reference set and 117 in the test set, and was used for validation of imputation from 54K to high density [777,000 markers (777K)]. Both test sets were divided into 4 groups according to their relationship to the reference population. Five imputation methods (Beagle, IMPUTE2, findhap, AlphaImpute, and FImpute) were used in this study. Imputation accuracy was measured as the allele correct rate and correlation between imputed and true genotypes. Results demonstrated that the accuracy was lower when imputing from 3K to 54K than from 54K to 777K. Using various imputation methods, the allele correct rates varied from 93.5 to 97.1% when imputing from 3K to 54K, and from 97.1 to 99.3% when imputing from 54K to 777K; IMPUTE2 and Beagle resulted in higher accuracies and were more robust under various conditions than the other 3 methods when imputing from 3K to 54K. The accuracy of imputation using FImpute was similar to those results from Beagle and IMPUTE2 when imputing from 54K to high density, and higher than the remaining 2 methods. The results also showed that a closer relationship between test set and reference set led to a higher accuracy for all the methods. In addition, the correct rate was higher when the minor allele frequency was lower, whereas the correlation coefficient was lower when the minor allele frequency was lower. The results indicate that Beagle and IMPUTE2 provide the most robust and accurate imputation accuracies, but considering computing time and memory usage, FImpute is another alternative method.

National rates of Helicobacter pylori recurrence are significantly and inversely correlated with human development index

BACKGROUND

Helicobacter pylori infection is a worldwide threat to human health with recurrence rates that vary widely. The precise correlation between H. pylori recurrence and socioeconomic development has not been determined.

AIM

To determine H. pylori recurrence rates after successful eradication and their association with socioeconomic development metrics.

METHODS

Bibliographical searches were performed in the MEDLINE database. We reviewed all results, filtered by inclusion criteria, extracted primary results to calculate H. pylori recurrence rates and calculated national Human Development Index (HDI) values for the periods during which the studies were conducted.

RESULTS

One thousand two hundred and twenty six cases of H. pylori recurrence in 77 eligible studies were observed in 43 525.1 follow-up patient-years after successful eradication therapy, giving a recurrence rate of 2.82 ± 1.16% per patient-year (weighted mean ± 95% confidence interval). H. pylori recurrence rate was inversely correlated with national HDI on linear (r = -0.633) and weighted least square (r = -0.546) regression analysis. Countries with very high HDI had a mean recurrence rate significantly lower than that of high, medium and low HDI countries (P < 0.01, 0.001, and 0.001, respectively).

CONCLUSIONS

Less-developed areas, as measured by HDI, are more likely to have high H. pylori recurrence rates. A different approach to follow-up after H. pylori eradication is needed in developing countries where reinfection is highly prevalent, paying special attention to sources of reinfection and high-risk groups.

Long-term seasonal trends of nitrogen, phosphorus, and suspended sediment load from the non-tidal Susquehanna River Basin to Chesapeake Bay

Reduction of nitrogen (N), phosphorus (P), and suspended sediment (SS) load has been a principal focus of Chesapeake Bay Watershed management for decades. To evaluate the progress of management actions in the Bay's largest tributary, the Susquehanna River, we analyzed the long-term seasonal trends of flow-normalized N, P, and SS load over the last two to three decades, both above and below the Lower Susquehanna River Reservoir System. Our results indicate that annual and decadal-scale trends of nutrient and sediment load generally followed similar patterns in all four seasons, implying that changes in watershed function and land use had similar impacts on nutrient and sediment load at all times of the year. Above the reservoir system, the combined loads from the Marietta and Conestoga Stations indicate general trends of N, P, and SS reduction in the Susquehanna River Basin, which can most likely be attributed to a suite of management actions on point, agricultural, and stormwater sources. In contrast, upward trends of SS and particulate-associated P and N were generally observed below the Conowingo Reservoir since the mid-1990s. Our analyses suggest that (1) the reservoirs' capacity to trap these materials has been diminishing over the past two to three decades, and especially so for SS and P since the mid-1990s, and that (2) the Conowingo Reservoir has already neared its sediment storage capacity. These changes in reservoir performance will pose significant new kinds of challenges to attainment of total maximum daily load goals for the Susquehanna River Basin, and particularly if also accompanied by increases in storm frequency and intensity due to climate change. Accordingly, the reservoir issue may need to be factored into the proper establishment of regulatory load requirements and the development of watershed implementation plans.

Research on pitting corrosion of steam generator heat transfer tubes based on acoustic emission

Corrosion of steam generator heat transfer tubes (SGHTT) is one of the important problems which affect safety operation of nuclear power plants (NPP), and the hazard of pitting corrosion of heat transfer tubes is the most serious. With an acoustic emission device, the signals during a corrosion test on SGHTT were collected and analyzed, and the corrosion points in the tubes were located accurately. The results show that pitting corrosion of heat transfer tubes has passed through three periods in its development: expansion phase, stationary phase and rapid developing phase. The corrosion damage of HTT can be found earlier with acoustic emission than any other non-destructive testing methods. Acoustic emission can be used for on-line and real-time monitoring of the safety and operation of the steam generator and has therefore a great significance.

The proprotein convertase furin is required for trophoblast syncytialization

The multinucleated syncytial trophoblast, which forms the outermost layer of the placenta and serves multiple functions, is differentiated from and maintained by cytotrophoblast cell fusion. Deficiencies in syncytial trophoblast differentiation or maintenance likely contribute to intrauterine growth restriction and pre-eclampsia, two common gestational diseases. The cellular and molecular mechanisms governing trophoblast syncytialization are poorly understood. We report here that the proprotein convertase furin is highly expressed in syncytial trophoblast in the first trimester human placentas, and expression of furin in the syncytiotrophoblast is significantly lower in the placentas from pre-eclamptic patients as compared with their gestational age-matched control placentas. Using multiple experimental models including induced fusion of choriocarcinoma BeWo cells and spontaneous fusion of primary cultured cytotrophoblast cells or placental explants, we demonstrate that cytotrophoblast cell fusion and syncytialization are accompanied by furin expression. Furin-specific siRNAs or inhibitors inhibit cell fusion in BeWo cells, as well as trophoblast syncytialization in human placental explants. Furthermore, type 1 IGF receptor (IGF1R) is indicated in this study as a substrate of furin, and processing of IGF1R by furin is an essential mechanism for syncytialization. Finally, using lentivirus-mediated RNAi targeting to mouse trophectoderm, we demonstrate that furin function is required for the development of syncytiotrophoblast structure in the labyrinth layer, as well as for normal embryonic development.