Joint effects of gray matter atrophy and altered functional connectivity on cognitive deficits in amnestic mild cognitive impairment patients

BACKGROUND

Gray matter (GM) atrophy and disrupted intrinsic functional connectivity (IFC) are often present in patients with amnestic mild cognitive impairment (aMCI), which shows high risk of developing into Alzheimer's disease. Little is known, however, about the relationship between GM atrophy and altered IFC, and whether they are related to cognitive decline.

METHOD

A total of 30 aMCI and 26 cognitively normal (CN) subjects were recruited for this study. Optimized voxel-based morphometric and resting-state functional connectivity magnetic resonance imaging approaches were performed to measure the GM volumes (GMVs) and atrophy-related IFC, respectively. Multivariate linear regression analysis was used to examine the effects of GM atrophy and IFC on cognitive performance across subjects, after controlling for the effects of age, education, gender and group.

RESULTS

Compared with CN subjects, aMCI subjects showed significantly reduced GMVs and decreased IFC in the frontal-parietal and medial temporal lobe systems. Multivariate regression analysis further demonstrated that the GMVs and decreased IFC simultaneously affected the cognitive function. Specifically, GMVs were positively correlated with cognitive performances, including global cognition and episodic memory, and showed a strong trend in correlation between GMVs and non-episodic memory, whilst IFC was positively correlated with the above three cognitive measures, across all subjects. In addition, significant correlation was found between GMVs and altered IFC strength across all subjects.

CONCLUSIONS

Our findings demonstrated that GMVs and IFC jointly contribute to cognitive performance, and combining quantitative information about GMVs and the strength of functional connectivity may serve as an indicator of cognitive deficits in non-demented elderly.

Development and characterization of new microsatellite markers of Fenneropenaeus penicillatus

Thirteen new polymorphic microsatellite markers in Fenneropenaeus penicillatus were isolated and characterized. The polymorphism of the thirteen microsatellite markers was tested by 30 individuals from Lianjiang, China. It showed that the number of al-leles per locus ranged from 3 to 6 and the Polymorphism Information Content (PIC) was from 0.324 to 0.706. The observed and expected heterozygosities were 0.3217-0.8023 and 0.1977-0.6783, respectively. Only one loci (LJ-19) deviated significantly from Hardy-Weinberg equilibrium (HWE) (P < 0.00385) after Bonferroni correction, while the other twelve markers were in HWE after Bonferroni correction (P > 0.00385). The thirteen polymorphic microsatellite markers could pro-vide more genetic data for further research on cultivation and recovery of F. penicillatus.

Screening and characterization of novel polymorphic microsatellite markers from sea cucumber Holothuria leucospilota

The sea cucumber Holothuria leucospilota has high me-dicinal value and rich nutritional edible value, and thus is a commercially important aquatic product in China. Microsatellite loci were developed and screened using a fast isolation protocol and amplified fragment length polymorphism of sequences containing repeats. In this study, 16 novel polymorphic microsatellite markers in H. leucospilota were identified, and the relevant genetic variability index was assessed using 30 individu-als from a wild population. The polymorphic information content ranged from 0.183 to 0.668, and the number of alleles per locus varied from 3 to 5. The observed and expected heterozygosities were 0.0370-0.5000 and 0.0776-0.6250, respectively. With the exception of 3 loci (Y1-15, Y11-1, and Y28), the polymorphic loci were in Hardy-Weinberg equilibrium (P > 0.003125). These polymorphic microsatellite loci will contribute to studies of genetic diversity, the research of population structure, and the design of conservation strategies for H. leucospilota.

Isolation and characterization of polymorphic microsatellite loci in the sea cucumber Holothuria scabra

The sea cucumber Holothuria scabra is an endangered species. In this study, nine new polymorphic microsatellite loci were developed and tested in 30 individuals. The number of alleles ranged from 2 to 5, and the observed and expected heterozygosities ranged from 0.1200 to 0.7391 and from 0.2408 to 0.5983, respectively. No loci significantly deviated from the Hardy-Weinberg equilibrium af-ter a Bonferroni correction, and no significant linkage disequilibrium was found between pairs of loci. These polymorphic microsatellite loci will be useful in studying the genetic diversity of H. scabra and its conservation.

Diagnostic value of aberrant gene methylation in stool samples for colorectal cancer or adenomas: a meta-analysis

AIM

Many studies have reported detection of aberrant methylation of genes in stool sample for early colorectal cancer (CRC) or adenomas had high sensitivity and specificity, but still remained controversial. We aimed to evaluate the diagnostic value of stool testing for markers of CRC and adenomas.

METHODS

Medline, EMbase, Web of Science, the Cochrane Library, and EMbase were systematically searched. Meta-analysis was performed using a random effects model with sensitivity, specificity, diagnostic OR (DOR), area under the summary ROC curves (SROC) and their 95% confidence interval (95% CI).

RESULTS

A total of 13 studies including 716 patients with CRC 220 cases of adenoma and 414 healthy controls were eligible for final analysis. The sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and DOR for the detection of CRC were 0.78 (95% CI: 0.75-0.82), 0.90 (95% CI: 0.91-0.96), 9.612 (95% CI: 6.761-13.666), 0.243 (95% CI: 0.176-0.336), and 48.21 (95% CI: 28.24-82.30), respectively. The sensitivity and specificity for the detection of adenoma were 0.63 (95% CI: 0.56-0.69) and 0.93 (95% CI: 0.90-0.96), respectively. The area under the SROC curve was 0.9438 and 0.9385 in CRC and adenoma detection, respectively.

CONCLUSION

Fecal gene methylation testing as a noninvasive method can be used as a screening measurement for CRC or colorectal adenoma with high sensitivity and specificity.

Non-invasive prenatal testing for trisomies 21, 18 and 13: clinical experience from 146,958 pregnancies

OBJECTIVES

To report the clinical performance of massively parallel sequencing-based non-invasive prenatal testing (NIPT) in detecting trisomies 21, 18 and 13 in over 140,000 clinical samples and to compare its performance in low-risk and high-risk pregnancies.

METHODS

Between 1 January 2012 and 31 August 2013, 147,314 NIPT requests to screen for fetal trisomies 21, 18 and 13 using low-coverage whole-genome sequencing of plasma cell-free DNA were received. The results were validated by karyotyping or follow-up of clinical outcomes.

RESULTS

NIPT was performed and results obtained in 146,958 samples, for which outcome data were available in 112,669 (76.7%). Repeat blood sampling was required in 3213 cases and 145 had test failure. Aneuploidy was confirmed in 720/781 cases positive for trisomy 21, 167/218 cases positive for trisomy 18 and 22/67 cases positive for trisomy 13 on NIPT. Nine false negatives were identified, including six cases of trisomy 21 and three of trisomy 18. The overall sensitivity of NIPT was 99.17%, 98.24% and 100% for trisomies 21, 18 and 13, respectively, and specificity was 99.95%, 99.95% and 99.96% for trisomies 21, 18 and 13, respectively. There was no significant difference in test performance between the 72,382 high-risk and 40,287 low-risk subjects (sensitivity, 99.21% vs. 98.97% (P = 0.82); specificity, 99.95% vs. 99.95% (P = 0.98)). The major factors contributing to false-positive and false-negative NIPT results were maternal copy number variant and fetal/placental mosaicism, but fetal fraction had no effect.

CONCLUSIONS

Using a stringent protocol, the good performance of NIPT shown by early validation studies can be maintained in large clinical samples. This technique can provide equally high sensitivity and specificity in screening for trisomy 21 in a low-risk, as compared to high-risk, population.

Optimization of SCoT-PCR reaction system in Dactylis glomerata by orthogonal design

The effects of 5 factors (template DNA, Mg(2+), dNTPs, Taq DNA polymerase, and primer) on the polymerase chain reaction (PCR) were investigated to optimize the start codon targeted polymor-phism (SCoT)-PCR system of Dactylis glomerata L., using an orthogo-nal design L16 (4(5)). A suitable SCoT-PCR system for D. glomerata was established; the 20 μL reaction volume contained 3.0 mM Mg(2+), 0.2 mM dNTPs, 1.0 U Taq DNA polymerase, 0.2 μM primer, 20 ng tem-plate DNA, and 2 μL 10X buffer. Each factor had a different effect on the amplification reaction, and the concentration of dNTPs had the larg-est effect on the SCoT-PCR system. We tested 10 orchardgrass samples to determine and verify the stability of the reaction system. The results showed that amplified bands from diverse materials were clear, stable, and rich in polymorphisms, indicating that the optimized system was very stable.

Study of e(+)e(-)→ωχ(cJ) at center of mass energies from 4.21 to 4.42 GeV

Based on data samples collected with the BESIII detector at the BEPCII collider at nine center of mass energies from 4.21 to 4.42 GeV, we search for the production of e^{+}e^{-}→ωχ_{cJ} (J=0, 1, 2). The process e^{+}e^{-}→ωχ_{c0} is observed for the first time, and the Born cross sections at sqrt[s]=4.23 and 4.26 GeV are measured to be (55.4±6.0±5.9) and (23.7±5.3±3.5)  pb, respectively, where the first uncertainties are statistical and the second are systematic. The ωχ_{c0} signals at the other seven energies and the e^{+}e^{-}→ωχ_{c1} and ωχ_{c2} signals are not significant, and the upper limits on the cross sections are determined. By examining the ωχ_{c0} cross section as a function of center of mass energy, we find that it is inconsistent with the line shape of the Y(4260) observed in e^{+}e^{-}→π^{+}π^{-}J/ψ. Assuming the ωχ_{c0} signals come from a single resonance, we extract the mass and width of the resonance to be (4230±8±6)  MeV/c^{2} and (38±12±2)  MeV, respectively, and the statistical significance is more than 9σ.

Unsteady aerodynamic analysis for offshore floating wind turbines under different wind conditions

A free-vortex wake (FVW) model is developed in this paper to analyse the unsteady aerodynamic performance of offshore floating wind turbines. A time-marching algorithm of third-order accuracy is applied in the FVW model. Owing to the complex floating platform motions, the blade inflow conditions and the positions of initial points of vortex filaments, which are different from the fixed wind turbine, are modified in the implemented model. A three-dimensional rotational effect model and a dynamic stall model are coupled into the FVW model to improve the aerodynamic performance prediction in the unsteady conditions. The effects of floating platform motions in the simulation model are validated by comparison between calculation and experiment for a small-scale rigid test wind turbine coupled with a floating tension leg platform (TLP). The dynamic inflow effect carried by the FVW method itself is confirmed and the results agree well with the experimental data of a pitching transient on another test turbine. Also, the flapping moment at the blade root in yaw on the same test turbine is calculated and compares well with the experimental data. Then, the aerodynamic performance is simulated in a yawed condition of steady wind and in an unyawed condition of turbulent wind, respectively, for a large-scale wind turbine coupled with the floating TLP motions, demonstrating obvious differences in rotor performance and blade loading from the fixed wind turbine. The non-dimensional magnitudes of loading changes due to the floating platform motions decrease from the blade root to the blade tip.

Association of the ApoE gene polymorphism and dietary factors with cerebral infarction and circulating lipid concentrations

The aim of this study was to explore the relationship between the ApoE gene polymorphism and dietary factors with stroke and circulating lipid levels in the Chinese population. We selected 580 patients with stroke and 580 age- and gender-matched healthy controls, and examined their ApoE polymorphism genotype using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. We also analyzed the relationship between the ApoE gene polymorphism and dietary factors as well as plasma lipid concentrations in this cohort. We detected six ApoE genotypes in the study populations, and determined that the E4 allele was positively associated with cerebral infarction (CI), whereas allele E2 was negatively associated with total cholesterol (TC) and low-density lipoprotein-cholesterol levels. The dietary habits of the subjects with descending order of average total TC and triglyceride levels were: subjects addicted to oily food > subjects addicted to sweets > subjects addicted to smoking > subjects addicted to alcohol > subjects following a vegetarian diet (P < 0.05). Our results demonstrated that the ApoE gene polymorphism was associated with a risk for CI in a Chinese population.

Isolation of new polymorphic microsatellite markers from the marbled rockfish Sebastiscus marmoratus

The marbled rockfish, Sebastiscus marmoratus, is an important commercially near-shore fish that inhabits the beach rocky bottom from Japan to the South China Sea. Eleven polymorphic microsatellite loci were developed from S. marmoratus and were used to identify polymorphisms in 30 samples from a wild population. The allele locus number ranged from 2 to 7. Polymorphism data content ranged from 0.032 to 0.751. The observed and expected heterozygosity levels were 0.0333-0.9667 and 0.0328-0.7675, respectively. Two loci, Smd1-112 and Smd2-80, deviated from Hardy-Weinberg equilibrium. These polymorphic microsatellite markers will facilitate further studies of genetic diversity and genetic differentiation of S. marmoratus.

CYP4F2 gene single nucleotide polymorphism is associated with ischemic stroke

The objective of this study was to explore the relationship between CYP4F2 gene polymorphism and ischemic stroke (IS) in the Han Chinese population. We performed a case-control study to genotype four single nucleotide polymorphisms (SNPs) (rs2108622, rs3093100, rs3093105, rs3093135) in the CYF4F2 gene. The genotype and haplotype distributions were compared between the case and control groups. We found that the GG genotype of rs2108622 in the CYP4F2 gene was associated with risk of IS (P = 0.023). Haplotype analysis indicated that the GGGT haplotype comprising rs2108622-rs3093100-rs3093105-rs3093135 was associated with IS, which suggests that the GGGT haplotype may be a risk factor for IS (P = 0.012). CYP4F2 gene polymorphism might increase the risk of IS in the Chinese population.

Development and characterization of polymorphic microsatellite loci in the sea cucumber Holothuria leucospilota

Holothuria leucospilota is a tropical holothurian species that is widely distributed in the tropical and sub-tropical India-Western Pacific Region. Eight polymorphic microsatellite loci were developed from H. leucospilota by using the protocol fast isolation by amplified fragment length polymorphism of sequences containing repeats and tested in 30 individuals from Hainan Island in China. The number of alleles was 2-6 and polymorphism information content ranged from 0.371-0.694. The levels of expected and observed heterozygosities varied from 0.3913-0.6701 and from 0.1154-0.7000, respectively. No significant linkage disequilibrium was detected for any pairwise combination of loci. Only loci YZHS1-42 deviated from Hardy-Weinberg equilibrium. These polymorphic microsatellite loci may be useful for germplasm conservation of H. leucospilota.

Cloning and characterization of a farnesyl pyrophosphate synthase from Matricaria recutita L. and its upregulation by methyl jasmonate

Matricaria recutita (L.), commonly known as chamomile, is one of the most valuable medicinal plants because it synthesizes a large number of pharmacologically active secondary metabolites known as α-bisabolol and chamazulene. Although the plant has been well characterized in terms of chemical constituents of essential oil as well as pharmacological properties, little is known about the genes responsible for biosynthesis of these compounds. In this study, we report a new full-length cDNA encoding farnesyl diphosphate synthase (FPS), a key enzyme in the pathway of biosynthesis of isoprenoids, from M. recutita. The cDNA of MrFPS comprises 1032 bp and encodes 343 amino acid residues with a calculated molecular mass of 39.4 kDa. The amino acid sequence homology and phylogenetic analysis indicated that MrFPS belongs to the plant FPS super-family and is closely related to FPS from the Asteraceae family. Expression of the MrFPS gene in Escherichia coli yielded FPS activity. Using real-time quantitative PCR, the expression pattern of the MrFPS gene was analyzed in different tissues of M. recutita as well as in response to methyl jasmonate. The expression analysis demonstrated that MrFPS expression varies in different tissues (with maximal expression in flowers and stems) and was significantly elevated in response to methyl jasmonate. This study will certainly enhance our understanding of the role of MrFPS in the biosynthesis and regulation of valuable secondary metabolites in M. recutita at a molecular level.

Isolation and characterization of novel microsatellite markers for molecular genetic diversity in Siganus fuscescens

The rabbitfish Siganus fuscescens is an economically valuable species that is widely distributed throughout the estuaries, intertidal, and offshore coasts of the Indo-Pacific and eastern Mediterranean. Ten novel microsatellite loci from the genome of S. fuscescens were developed using the fast isolation protocol with amplified fragment length polymorphism of sequences containing repeats. Polymorphisms in these 10 microsatellite markers were determined from 32 wild individuals. The number of alleles per locus and the polymorphism information content ranged from 2 to 5 and from 0.059 to 0.668, respectively. The observed and expected heterozygosities varied from 0.063 to 0.781 and from 0.062 to 0.731, respectively. Although 1 locus (LZY-X7, P < 0.005) showed significant deviation from the Hardy-Weinberg equilibrium, no deviations were detected in the other 9 loci. These microsatellite loci may be useful for further population genetic studies, conservation studies, population structure assessment, and linkage map construction of S. fuscescens.

Incidence and factors associated with nosocomial infections in a neonatal intensive care unit (NICU) of an urban children's hospital in China

OBJECTIVE

The study's aim was to assess incidence and epidemiologic profile of nosocomial infection (NI) in a NICU of China, and to identify main risk factors of NIs.

MATERIALS AND METHODS

Chi square test for discrete variables and independent t-test for continuous variables to examine the association with NI. Univariate regression model was applied to the variables to predict the NI status. Finally the multivariate model was utilized with stepwise methods included all variables in the univariate model to extrapolate the independent variables to NI.

RESULTS

Infection rate in NICU during the study period was 6.2 episodes per 100 patients. Infection density was 4.2 episodes per 1,000 patient-days. Infection rate of ventilation-related pneumonia was 3.4 episodes per 1,000 mechanical ventilation (MV) days. Central line-associated bloodstream infection rate was 5.4 episodes per 1,000 central line days. Gestational age < 32 weeks, with congenital malformation, twins or triplets, gastric tube feeding, operation, duration of prophylaxis antibiotic use, duration of probiotic use, duration of parenteral nutrition were the risk factors associated with NI in NICU. We discussed the association between intrinsic factors of infants and health care procedures with NI.

CONCLUSION

This study provided information for prevention strategies of NI, that will ultimately improve the healthcare service level.