Microsomal prostaglandin E synthase-1 promotes hepatocarcinogenesis through activation of a novel EGR1/β-catenin signaling axis

Microsomal prostaglandin E synthase-1 (mPGES-1) is a key enzyme that couples with cyclooxygenase-2 (COX-2) for the production of PGE₂. Although COX-2 is known to mediate the growth and progression of several human cancers including hepatocellular carcinoma (HCC), the role of mPGES-1 in hepatocarcinogenesis is not well established. This study provides novel evidence for a key role of mPGES-1 in HCC growth and progression. Forced overexpression of mPGES-1 in two HCC cell lines (Hep3B and Huh7) increased tumor cell growth, clonogenic formation, migration and invasion, whereas knockdown of mPGES-1 inhibited these parameters, in vitro. In a SCID mouse tumor xenograft model, mPGES-1 overexpressed cells formed palpable tumors at earlier time points and developed larger tumors when compared to the control (p<0.01); in contrast, mPGES-1 knockdown delayed tumor development and reduced tumor size (p<0.01). Mechanistically, mPGES-1-induced HCC cell proliferation, invasion and migration involve PGE₂ production and activation of early growth response 1 (EGR1) and β-catenin. Specifically, mPGES-1-derived PGE₂ induces the formation of EGR1-β-catenin complex, which interacts with TCF4/LEF1 transcription factors and activates the expression of β-catenin downstream genes. Our findings depict a novel crosstalk between mPGES-1/PGE₂ and EGR1/β-catenin signaling that is critical for hepatocarcinogenesis.

Measurement of GSTP1 promoter methylation in body fluids may complement PSA screening: a meta-analysis

BACKGROUND

Prostate-specific antigen (PSA) screening has low specificity. Assessment of methylation status in body fluids may complement PSA screening if the test has high specificity.

METHOD

The purpose of this study was to conduct a meta-analysis of the sensitivity and specificity for prostate cancer detection of glutathione-s-transferase-π (GSTP1) methylation in body fluids (plasma, serum, whole blood, urine, ejaculate, and prostatic secretions). We conducted a comprehensive literature search on Medline (Pubmed). We included studies if they met all four of the following criteria: (1) measurement of DNA methylation in body fluids; (2) a case-control or case-only design; (3) publication in an English journal; and (4) adult subjects. Reviewers conducted data extraction independently using a standardised protocol. Twenty-two studies were finally included in this paper. Primer sequences and methylation method in each study were summarised and evaluated using meta-analyses. This paper represents a unique cross-disciplinary approach to molecular epidemiology.

RESULTS

The pooled specificity of GSTP1 promoter methylation measured in plasma, serum, and urine samples from negative-biopsy controls was 0.89 (95% CI, 0.80-0.95). Stratified analyses consistently showed a high specificity across different sample types and methylation methods (include both primer sequences and location). The pooled sensitivity was 0.52 (95% CI, 0.40-0.64).

CONCLUSIONS

The pooled specificity of GSTP1 promoter methylation measures in plasma, serum, and urine was excellent and much higher than the specificity of PSA. The sensitivity of GSTP1 was modest, no higher than that of PSA. These results suggest that measurement of GSTP1 promoter methylation in plasma, serum, or urine samples may complement PSA screening for prostate cancer diagnosis.

UV light emitting transparent conducting tin-doped indium oxide (ITO) nanowires

Multifunctional single crystalline tin-doped indium oxide (ITO) nanowires with tuned Sn doping levels are synthesized via a vapor transport method. The Sn concentration in the nanowires can reach 6.4 at.% at a synthesis temperature of 840 °C, significantly exceeding the Sn solubility in ITO bulks grown at comparable temperatures, which we attribute to the unique feature of the vapor-liquid-solid growth. As a promising transparent conducting oxide nanomaterial, layers of these ITO nanowires exhibit a sheet resistance as low as 6.4 Ω/[Symbol: see text] and measurements on individual nanowires give a resistivity of 2.4 × 10(-4) Ω cm with an electron density up to 2.6 × 10(20) cm(-3), while the optical transmittance in the visible regime can reach ∼ 80%. Under the ultraviolet excitation the ITO nanowire samples emit blue light, which can be ascribed to transitions related to defect levels. Furthermore, a room temperature ultraviolet light emission is observed in these ITO nanowires for the first time, and the exciton-related radiative process is identified by using temperature-dependent photoluminescence measurements.

Functional expression of P2X4 receptor in capillary endothelial cells of the cochlear spiral ligament and its role in regulating the capillary diameter

The cochlear lateral wall generates the endocochlear potential (EP), which creates a driving force for the hair cell transduction current and is essential for normal hearing. Blood flow at the cochlear lateral wall is critically important for maintaining the EP. The vulnerability of the EP to hypoxia suggests that the blood flow in the cochlear lateral wall is dynamically and precisely regulated to meet the changing metabolic needs of the cochlear lateral wall. It has been reported that ATP, an important extracellular signaling molecule, plays an essential role in regulating cochlear blood flow. However, the cellular mechanism underlying ATP-induced regional blood flow changes has not been investigated. In the current study, we demonstrate that 1) the P2X4 receptor is expressed in endothelial cells (ECs) of spiral ligament (SL) capillaries. 2) ATP elicits a characteristic current through P2X4 on ECs in a dose-dependent manner (EC(50) = 0.16 mM). The ATP current has a reversal potential at ∼0 mV; is inhibited by 5-(3-bromophenyl)-1,3-dihydro-2H-benzofuro[3,2-e]-1,4-diazepin-2-one (5-BDBD), LaCl(3), pyridoxal phosphate-6-azo(benzene-2,4-disulfonic acid) tetrasodium salt hydrate (PPADS), and extracellular acidosis; and is less sensitive to α,β-methyleneadenosine 5'-triphosphate (α,β-MeATP) and 2'- and 3'-O-(4-benzoyl-benzoyl) adenosine 5'-triphosphate (BzATP). 3) ATP elicits a transient increase of intracellular Ca(2+) in ECs. 4) In accordance with the above in vitro findings, perilymphatic ATP (1 mM) caused dilation in SL capillaries in vivo by 11.5%. N(ω)-nitro-l-arginine methyl ester hydrochloride (l-NAME), a nonselective inhibitor of nitric oxide synthase, or 5-BDBD, the specific P2X4 inhibitor, significantly blocked the dilation. These findings support our hypothesis that extracellular ATP regulates cochlear lateral blood flow through P2X4 activation in ECs.

Mechanisms Causing Capacity Loss on Long Term Storage in NiMH System

Capacity recovery after long term storage and loaded storage is a critical issue with the NiMH system since its inception. A measurable loss in capacity is observed when cells are stored for long periods of time or discharged deeply to zero volts. The different mechanisms that are known to cause self discharge and capacity loss after storage and loaded storage will be the focus of this paper. Capacity loss after long term storage involves two main events. One is self discharge which causes the open circuit voltage(OCV) of the cell to drop. Self discharge is caused by decomposition of NiOOH, migration of metal ions and possible degradation of separator. Self discharge can be prevented by using separators which are stable at high temperatures and pH and have good ion trapping capability. Various separator types and treatments can play an important role in inhibiting metal ions from migrating thus reducing self discharge. Self discharge during storage causes a severe suppression in the voltage of the foam positive electrode. This drop in voltage causes a breakdown of the cobalt conductive network in the nickel positive electrode. Reduction of high valence cobalt(III) which forms the electrode's conductive network takes place at these low voltages. A permanent breakdown in the conductive network results in low efficiency of the cell on consecutive charge and discharge cycles. In addition, the cobalt in its lower valence states can migrate away from the electrode into the separator causing shorts. These events effect the charge and discharge efficiency of these cells thereby resulting in capacity loss. Various mechanisms causing self discharge which affect capacity recovery after long term storage and loaded storage are discussed in this paper.

Effect of capsaicin on potassium conductance and electromotility of the guinea pig outer hair cell

Capsaicin, the classic activator of TRPV-1 channels in primary sensory neurons, evokes nociception. Interestingly, auditory reception is also modulated by this chemical, possibly by direct actions on outer hair cells (OHCs). Surprisingly, we find two novel actions of capsaicin unrelated to TRPV-1 channels, which likely contribute to its auditory effects in vivo. First, capsaicin is a potent blocker of OHC K conductances (I(K) and I(K,n)). Second, capsaicin substantially alters OHC nonlinear capacitance, the signature of electromotility - a basis of cochlear amplification. These new findings of capsaicin have ramifications for our understanding of the pharmacological properties of OHC I(K), I(K,n) and electromotility and for interpretation of capsaicin pharmacological actions.

Rotavirus infection in adult small intestine allografts: a clinicopathological study of a cohort of 23 patients

Rotavirus enteritis (RVE) is increasingly recognized as a cause of small bowel allograft dysfunction but its significance in adult patients is unknown. We have studied 23 adult small bowel transplant patients aged 19.8-59 years (mean = 38.2 years), who were presented with diarrhea and tested positive for rotavirus by enzyme-linked immunosorbent assay methods. Serial follow-up biopsies, as well as clinical data, are documented and analyzed. These patients were followed up for an average of 168 days (range 33-534 days). Mean time of rotavirus diagnosis from transplant day was 794 days (range 38-2907 days). Self-limited diarrhea lasting 6-13 days (mean = 9 days) was the main presentation. Sixteen (69.6%) patients developed acute cellular rejection either concurrently with (i.e. six patients) or after (10 patients) RVE, often characterized by prominent mucosal plasmacytosis at an average of 22 days (range 0-94 days) from the day RVE was diagnosed. One-third of patients with acute rejection (i.e. five out of 16) required muromonab-CD3 rescue therapy. Two patients experienced graft loss (one from chronic rejection, another from sepsis). Rotavirus infection is a cause of diarrhea in adult small bowel transplant patients. The infection appeared to trigger cellular rejection that was associated with mucosal plasmacytosis, and sometimes required aggressive rescue therapy.

Tunable magnetic interaction at the atomic scale in oxide heterostructures

We report on a systematic study of a number of structurally identical but chemically distinct transition metal oxides in order to determine how the material-specific properties such as the composition and the strain affect the properties at the interface of heterostructures. Our study considers a series of structures containing two layers of ferromagnetic SrRuO₃, with antiferromagnetic insulating manganites sandwiched in between. The results demonstrate how to control the strength and relative orientation of interfacial ferromagnetism in correlated electron materials by means of valence state variation and substrate-induced strain, respectively.

A rapid assay for simultaneous detection of Spiroplasma eriocheiris and white spot syndrome virus in Procambarus clarkii by multiplex PCR

AIMS

To establish a multiplex PCR method for simultaneous and rapid detection of Spiroplasma eriocheiris and white spot syndrome virus (WSSV) in Procambarus clarkii with recommendations for application to other crustacea.

METHODS AND RESULTS

Three primer sets were mixed at a ratio of 1:3:1 to amplify specific fragments of the S. eriocheiris, WSSV, P. clarkii crayfish (control organism) genomes, respectively. S. eriocheiris and WSSV were used to challenge the susceptible crustacea in the experimental groups. Total DNA of the samples was purified and detected by multiplex PCR. The PCR-amplified products produced four groups of results as follows. One fragment of 1195 bp, amplified by the primer set ITS-crayfish/28S-crayfish, served as an internal control, showed no pathogen detection, thus confirming the specificity of our positive tests. Two groups represented by: (i) samples challenged by S. eriocheiris alone, or (ii) challenged by WSSV alone, yielded two fragments each; i.e. those from S. eriocheiris (271 bp) plus the internal control and those from WSSV (530 bp) plus the internal control. Finally, for the fourth group, in cases of double challenged treatments, all three amplified products were detected simultaneously.

CONCLUSIONS

Simultaneous and rapid detection of two pathogens in P. clarkii is important to maintain productive and healthy crayfish in aquaculture. The direct detection of S. eriocheiris and WSSV from P. clarkii is practicable with multiplex PCR.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study shows that the two pathogens are simultaneously and rapidly detected in P. clarkii by multiplex PCR, thus increasing the efficiency of pathogen detection.

Drosophila vitelline membrane assembly: a critical role for an evolutionarily conserved cysteine in the "VM domain" of sV23

The vitelline membrane (VM), the oocyte proximal layer of the Drosophila eggshell, contains four major proteins (VMPs) that possess a highly conserved "VM domain" which includes three precisely spaced, evolutionarily conserved, cysteines (CX⁷CX⁸C). Focusing on sV23, this study showed that the three cysteines are not functionally equivalent. While substitution mutations at the first (C123S) or third (C140S) cysteines were tolerated, females with a substitution at the second position (C131S) were sterile. Fractionation studies showed that sV23 incorporates into a large disulfide linked network well after its secretion ceases, suggesting that post-depositional mechanisms are in place to restrict disulfide bond formation until late oogenesis, when the oocyte no longer experiences large volume increases. Affinity chromatography utilizing histidine tagged sV23 alleles revealed small sV23 disulfide linked complexes during the early stages of eggshell formation that included other VMPs, namely sV17 and Vml. The early presence but late loss of these associations in an sV23 double cysteine mutant suggests that reorganization of disulfide bonds may underlie the regulated growth of disulfide linked networks in the vitelline membrane. Found within the context of a putative thioredoxin active site (CXXS) C131, the critical cysteine in sV23, may play an important enzymatic role in isomerizing intermolecular disulfide bonds during eggshell assembly.

Electroluminescence from n-In2O3:Sn randomly assembled nanorods/p-SiC heterojunction

Room-temperature electroluminescence (EL) has been realized from Sn-doped In(2)O(3) (In(2)O(3):Sn) nanorods. Heterojunction light-emitting diode (LED) was formed by depositing a layer of randomly packed n-In(2)O(3):Sn nanorods onto a p-type 4H-SiC substrate. It is found that the emission intensity of the heterojunction LED under forward bias can be maximized by doping the In(2)O(3) nanorods with 3 mol. % of Sn. Furthermore, two emission peaks of the EL spectra are observed at approximately 395 and approximately 440 nm. These ultraviolet and visible peaks are attributed to the radiative recombination at Sn induced and intrinsic defect states of the In(2)O(3):Sn nanorods.

Ultrathin single-crystal ZnO nanobelts: Ag-catalyzed growth and field emission property

We report the growth of ultrathin single-crystal ZnO nanobelts by using a Ag-catalyzed vapor transport method. Extensive transmission electron microscopy and atomic force microscopy measurements reveal that the thickness of the ultrathin ZnO nanobelts is approximately 2 nm. Scanning electron microscopy and post-growth annealing studies suggest a '1D branching and 2D filling' growth process. Our results demonstrate the critical role of catalyst in the deterministic synthesis of nanomaterials with the desired morphology. In addition, these ultrafine nanobelts exhibit stable field emission with unprecedented high emission current density of 40.17 mA cm(-2). These bottom-up building blocks of ultrathin ZnO nanobelts may facilitate the construction of advanced electronic and photonic nanodevices.

Random lasing action of randomly assembled ZnO nanowires with MgO coating

Lasing characteristics of randomly assembled ZnO nanowires (NWs) coated with different thickness of MgO layers are investigated. It is found that the MgO coated randomly assembled ZnO NWs demonstrate random lasing action and the formation of coherent optical feedback is dependent on the thickness of MgO coating. Pump threshold of the MgO coated randomly assembled ZnO NWs increases with the increase of MgO thickness. Nevertheless, the appropriate use of MgO coating can reduce the pump threshold by approximately 30% and the corresponding characteristic temperature can be improved by 28 K.

Evidence for competing magnetic and superconducting phases in superconducting Eu 1-x Sr x Fe 2-y Co y As 2 single crystals

In single crystals of Eu(1-x)Sr(x)Fe(2-y)Co(y)As(2), Co doping suppresses spin-density wave (SDW) ordering and induces a superconducting transition. A resistivity reentrance due to the antiferromagnetic ordering of Eu(2+) spins is observed, indicating the competition between antiferromagnetism (AFM) and superconductivity (SC). It is striking that the resistivity reentrance can be completely suppressed by a small magnetic field due to a field-induced metamagnetic transition from AFM to ferromagnetism (FM). The resistivity reentrance can also be suppressed by the substitution of Eu(2+) ions with nonmagnetic Ba(2+)/Sr(2+) to completely destroy the AFM ordering. These results indicate that the AFM order appears destructive to SC, while FM can coexist with the superconductivity. Further we find that magnon excitation exists in AFM ordering and can be suppressed by an applied field. Coexistence of SC from the FeAs layer and the inner field produced by the ferromagnetic Eu(2+) layer suggest a possible p-wave component in the superconducting order parameter.