Dysfunction of fronto-limbic brain circuitry in depression

BACKGROUND

depression is characterized by a stable negative bias toward emotional stimuli. This bias is associated with abnormal activities in emotion-processing regions (such as the amygdala) and cognitive-control regions (such as the dorsolateral prefrontal cortex [DLPFC]). However, it remains unclear whether the emotion-processing and cognitive-control regions affect negative cognitive bias independently or reciprocally.

EXPERIMENTAL PROCEDURE

a functional magnetic resonance imaging (fMRI) study of 16 depressed patients and 16 matched control subjects was conducted during an emotion-interference task.

RESULTS

the accuracies were significantly lower in the depressed group than in the control group when subjects attended to the happy and the neutral faces. Compared with control participants, depressed patients showed abnormal activity in bilateral amygdala and the right DLPFC. In addition, a significant correlation was found between the right amygdala and the right DLPFC when subjects observed the happy faces.

CONCLUSIONS

the results suggest that the dysfunction in positive emotion-processing and cognitive-control regions may reciprocally affect negative cognitive bias. Additionally, altered positive emotional interference processing in the fronto-limbic brain circuitry might be another cause of negative cognitive bias that finally leads to depression.

Effect of downregulated β-catenin on cell proliferative activity, the sensitivity to chemotherapy drug and tumorigenicity of ovarian cancer cells

The role of Wnt/β-catenin signaling pathway in the etiology and/or progression of ovarian cancer has been well documented. It was demonstrated that ovarian cancer constantly exhibit constitutive activation of canonical Wnt signaling, usually as a result of oncogenic mutations that stabilize and dysregulate the β-catenin protein. In this study, we transfected an expression vector-based small hairpin RNA (shRNA) targeting to β-catenin encoding gene into human A2780 ovarian cancer cells to investigate the effects of β-catenin knockdown on biological characteristics of ovarian cancer cells. The results showed that β-catenin shRNA expression resulted in decreased β-catenin mRNA and protein expression in the transfected A2780 cells, inhibition of cellular proliferation, decreased capability of clonogenicity in the plating and the soft agar, and increased sensitivities to chemotherapy drugs vincristine, paclitaxel and cisplatin compared to untransfected cells. Importantly, we found that shRNA-mediated knockdown of β-catenin strongly decreases tumour growth of human A2780 ovarian cancer cells in xenografts. These results demonstrate that β-catenin might be an effective therapeutic target for human ovarian cancer treatment.

Fractionated radiation-induced acute encephalopathy in a young rat model: cognitive dysfunction and histologic findings

BACKGROUND AND PURPOSE

Radiation-induced cognitive dysfunction is a common and serious complication after radiation therapy of brain tumor, yet knowledge of its mechanism is poorly understood. The aim of this study was to establish a young rat model for acute radiation encephalopathy, at both cognitive and pathologic levels, induced by fractionated irradiation.

MATERIALS AND METHODS

Four-week-old male rats were randomized into sham (0 Gy) and 2 experimental groups receiving fractionated irradiation of 5 Gy/day, 5 days/week, with total doses of 20 and 40 Gy, respectively. Cognition, BBB integrity, and potential astrogliosis were evaluated at 0, 4, 8, and 12 weeks' postirradiation.

RESULTS

Twenty-Gy irradiation led to transient cognitive impairment only at 4 weeks' postirradiation. Forty-Gy irradiation induced cognitive impairment at both 4 and 8 weeks' postirradiation, which was more severe than that induced by 20 Gy. Cognitive impairment was accompanied by a transient increase in BWC only at 4 weeks for the 40-Gy group. Disrupted BBB permeability was detected at 4 and 8 weeks' postirradiation for the 20-Gy group, and at 4, 8, and 12 weeks' postirradiation for 40-Gy group, respectively. Increased astrogliosis in the hippocampus could be detected at 4 weeks' postirradiation for 40-Gy group.

CONCLUSIONS

Fractionated irradiation in this experiment could induce acute brain injury, leading to cognitive impairment in young rats. BBB disruption might be a sensitive index for acute radiation encephalopathy. In addition, reactive astrogliosis might play an important role in this process. The present model, especially the 40-Gy irradiation group, is useful for basic and therapeutic studies of acute radiation encephalopathy.

Higher harmonic anisotropic flow measurements of charged particles in Pb-Pb collisions at sqrt(s(NN)) = 2.76 TeV

We report on the first measurement of the triangular v3, quadrangular v4, and pentagonal v5 charged particle flow in Pb-Pb collisions at sqrt(s(NN)) = 2.76  TeV measured with the ALICE detector at the CERN Large Hadron Collider. We show that the triangular flow can be described in terms of the initial spatial anisotropy and its fluctuations, which provides strong constraints on its origin. In the most central events, where the elliptic flow v2 and v3 have similar magnitude, a double peaked structure in the two-particle azimuthal correlations is observed, which is often interpreted as a Mach cone response to fast partons. We show that this structure can be naturally explained from the measured anisotropic flow Fourier coefficients.

Causes of death among people with convulsive epilepsy in rural West China: a prospective study

BACKGROUND

Epilepsy is a serious health problem associated with an increased risk of premature mortality. Few studies have investigated risk factors for this. Understanding these risks may enable the implementation of preventative measures to reduce premature mortality.

METHODS

A management program for convulsive forms of epilepsy has been in place at the primary health care level in rural West China since May 2005. Demographic data and putative causes of death of attendees of the program since inception to the end of December 2009 have been recorded. Case fatality (CF), the proportional mortality ratios (PMRs) for each cause, and standardized mortality ratios (SMRs) for each age and cause were estimated based on the 2007 Chinese rural population.

RESULTS

There were 106 reported deaths (70 male) among 3,568 people. CF was 2.97% during a median of 28 months' follow-up. The highest PMRs were for accidental death (59%) including drowning (45.1%); probable sudden unexpected death in epilepsy (SUDEP) (14.7%); status epilepticus (6.9%), and neoplasm (6.9%). The overall SMR was 4.92 (95% confidence interval 4.0-6.1); the risks were high in young people. The risk of drowning was 82-fold higher in the cohort than the general population.

CONCLUSION

In rural West China, the risk of premature death is nearly 5 times higher in people with convulsive epilepsy than in the general Chinese population and especially high among young people. Accidental death, including drowning, and probable SUDEP are the leading putative causes of death in people with convulsive epilepsy in rural West China.

XRCC1 Arg399Gln and Arg194Trp polymorphisms in prostate cancer risk: a meta-analysis

Epidemiological studies have evaluated the association between X-ray repair cross-complementing group 1 gene (XRCC1) Arg399Gln and Arg194Trp polymorphisms and risk of prostate cancer (PCa). However, the results from the published studies on the association between these two XRCC1 polymorphisms and PCa risk are conflicting. To derive a more precise estimation of association between the XRCC1 polymorphisms and risk of PCa, we performed a meta-analysis. A comprehensive search was conducted to identify all case-control studies of XRCC1 polymorphisms and PCa risk. We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association. Overall, we found that both Arg399Gln and Arg194Trp polymorphisms were not significantly associated with PCa risk. However, in stratified analysis by ethnicity, we found that the Arg399Gln polymorphism was significantly associated with PCa risk in Asian population (Gln/Gln vs Arg/Arg: OR=1.46, 95% CI: 1.05-2.03, P=0.03; Gln/Gln vs Arg/Gln+Arg/Arg: OR=1.48, 95% CI: 1.12-1.95, P=0.01). In this meta-analysis, we found that both Arg399Gln and Arg194Trp polymorphisms were not related to overall PCa risk. However, in subgroup analysis we found a suggestion that XRCC1 399Gln allele might be a low-penetrent risk factor for PCa only in Asian men.

H63D polymorphism in the hemochromatosis gene is associated with sporadic amyotrophic lateral sclerosis in China

BACKGROUND AND PURPOSE

The H63D polymorphism in the hemochromatosis (HFE) gene has been reported as a risk factor for amyotrophic lateral sclerosis (ALS) in Europe and America, but no data have been reported for Asia. Here, we investigated the possible association between H63D and sporadic ALS (sALS) in a Chinese Han population.

METHODS

A total of 195 individuals with sALS from three centers in China and 405 unrelated healthy controls were recruited. All subjects were genotyped by restriction fragment length polymorphism (RFLP) analysis.

RESULTS

Sporadic ALS was significantly related to the H63D polymorphism in heterozygous carriers (odds ratio 3.10, 95%CI: 1.49-6.47, P=0.002).

CONCLUSIONS

The HFE H63D polymorphism may contribute to the development of sALS in Chinese.

Serological and virological surveillance of swine H1N1 and H3N2 influenza virus infection in two farms located in Hubei province, central China

Swine influenza viruses H1N1 and H3N2 have been reported in the swine population worldwide. From June 2008 to June 2009, we carried out serological and virological surveillance of swine influenza in the Hubei province in central China. The serological results indicated that antibodies to H1N1 swine influenza virus in the swine population were high with a 42.5% (204/480) positive rate, whereas antibodies to H3N2 swine influenza virus were low with a 7.9% (38/480) positive rate. Virological surveillance showed that only one sample from weanling pigs was positive by RT-PCR. Phylogenetic analysis of the hemagglutinin and neuraminidase genes revealed that the A/Sw/HB/S1/2009 isolate was closely related to avian-like H1N1 viruses and seemed to be derived from the European swine H1N1 viruses. In conclusion, H1N1 influenza viruses were more dominant in the pig population than H3N2 influenza viruses in central China, and infection with avian-like H1N1 viruses persistently emerged in the swine population in the area.

Electron Emission Properties of Si Field Emitter Arrays Coated With Nanocrystalline Diamond From Fullerene Precursors

In this paper, we report on a substantial lowering of the threshold field for electron field emission from Si field emitter arrays (FEA), which have been coated with a thin layer of nanocrystalline diamond by microwave plasma-assisted chemical vapor deposition (MPCVD) from fullerene (C60) and methane (CH4) precursors. The field emission characteristics were investigated and the emission sites imaged using photoelectron emission microscopy (PEEM). Electron emission from these Si FEAs coated with nanocrystalline diamond was observed at threshold fields as low as 3 V/μm, with effective work functions as low as 0.59 eV.

Centrality dependence of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at sqrt[s(NN)] = 2.76 TeV

The centrality dependence of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at sqrt[s_{NN}]=2.76  TeV is presented. The charged-particle density normalized per participating nucleon pair increases by about a factor of 2 from peripheral (70%-80%) to central (0%-5%) collisions. The centrality dependence is found to be similar to that observed at lower collision energies. The data are compared with models based on different mechanisms for particle production in nuclear collisions.

Contribution of hydrodynamic characteristics on the performance of an aerobic biofilm conical fluidized bed

The performance of a conical fluidized bed (TFB) bioreactor, including the biofilm thickness, microbial space density, microbial cell matrix and its efficiency for COD degradation at a bed expansion ratio of 14 to 90%, was studied and compared with a cylindrical fluidized bed (CFB) bioreactor. The hydrodynamic characteristics of the TFB, especially the internal-circulation of bioparticles associated with its unique tapered geometry of the bed, created a much more uniform axial distribution of the bioparticles, leading to the formation of thinner and more compacted biofilms in the TFB compared to that in the CFB. The thinner biofilm in the TFB tended to be stable and possessed more than 6 times of microbial population density compared to the CFB. As a result, thinner biofilms in the TFB contributed to a higher COD removal efficiency, which remained at over 95% at operated expansion ratios, about 15 to 25% higher than that in the CFB.

Elliptic flow of charged particles in Pb-Pb collisions at sqrt[S(NN)] = 2.76 TeV

We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at sqrt[S(NN)] =2.76 TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (|η|<0.8) and transverse momentum range 0.2<p t<5.0 GeV/c. The elliptic flow signal v₂, measured using the 4-particle correlation method, averaged over transverse momentum and pseudorapidity is 0.087 ± 0.002(stat) ± 0.003(syst) in the 40%-50% centrality class. The differential elliptic flow v₂ p t reaches a maximum of 0.2 near p t =3 GeV/c. Compared to RHIC Au-Au collisions at sqrt[S(NN)] 200 GeV, the elliptic flow increases by about 30%. Some hydrodynamic model predictions which include viscous corrections are in agreement with the observed increase.

Charged-particle multiplicity density at midrapidity in central Pb-Pb collisions at sqrt[S(NN)] = 2.76 TeV

The first measurement of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at a center-of-mass energy per nucleon pair √ S NN = 2.76 TeV is presented. For an event sample corresponding to the most central 5% of the hadronic cross section, the pseudorapidity density of primary charged particles at midrapidity is 1584 ± 4(stat) ± 76(syst), which corresponds to 8.3 ± 0.4(syst) per participating nucleon pair. This represents an increase of about a factor 1.9 relative to pp collisions at similar collision energies, and about a factor 2.2 to central Au-Au collisions at √ S NN = 2.76 TeV. This measurement provides the first experimental constraint for models of nucleus-nucleus collisions at LHC energies.

Mst1/2 signalling to Yap: gatekeeper for liver size and tumour development

The mechanisms controlling mammalian organ size have long been a source of fascination for biologists. These controls are needed to both ensure the integrity of the body plan and to restrict inappropriate proliferation that could lead to cancer. Regulation of liver size is of particular interest inasmuch as this organ maintains the capacity for regeneration throughout life, and is able to regain precisely its original mass after partial surgical resection. Recent studies using genetically engineered mouse strains have shed new light on this problem; the Hippo signalling pathway, first elucidated as a regulator of organ size in Drosophila, has been identified as dominant determinant of liver growth. Defects in this pathway in mouse liver lead to sustained liver overgrowth and the eventual development of both major types of liver cancer, hepatocellular carcinoma and cholangiocarcinoma. In this review, we discuss the role of Hippo signalling in liver biology and the contribution of this pathway to liver cancer in humans.

Association between carbamazepine-induced cutaneous adverse drug reactions and the HLA-B*1502 allele among patients in central China

The aim of this study was to investigate the association between carbamazepine (CBZ)-induced cutaneous adverse drug reactions (cADRs) and the HLA-B*1502 allele among patients from central China. Eight patients with Stevens-Johnson syndrome and toxic epidermal necrolysis (SJS/TEN), 28 with mild maculopapular eruptions (MPEs), 50 CBZ-tolerant controls, and 71 healthy volunteers were recruited. HLA genotyping was performed using the polymerase chain reaction sequence-based typing (SBT) method. As a result, the HLA-B*1502 allele was observed at the following rates: (1) 100% (8/8) among those with CBZ-induced SJS/TEN, (2) 10.7% (3/28) among those with CBZ-induced MPEs; (3) 8.0% (4/50) among CBZ-tolerant controls; (4) 8.5% (6/71) among healthy volunteers. The eight patients with SJS/TEN positive for the HLA-B*1502 allele had an odds ratio (OR) of 184 compared with CBZ-tolerant controls. There was no significant difference in frequency between patients with MPEs and CBZ-tolerant controls (P>0.05). Thus, CBZ-induced SJS/TEN, but not MPEs, is strongly associated with HLA-B*1502. Testing for HLA-B*1502 should be recommended for patients from central China prior to initial CBZ treatment.