On the mechanism of gas adsorption for pristine, defective and functionalized graphene

Defects are no longer deemed an adverse aspect of graphene.

A case of placental mesenchymal dysplasia with one year follow-up

Placental mesenchymal dysplasia (PMD) is a rare placental disease with unknown etiology. Because of the malformation of the placenta, the incidence of the obstetric complications and the poor perinatal outcomes are higher than usual. PMD usually accompanies with Beckwith-Wiedemann syndrome. In this article, the authors report a case of PMD with a live delivery in 35+5 gestational weeks. The phenotype of the neonate was normal. During the one-year follow-up, the development of the child was normal.

Autoimmune risk loci of IL12RB2, IKZF1, XKR6, TMEM39A and CSK in Chinese patients with systemic lupus erythematosus

Recent genome-wide or follow-up studies conducted in European or Caucasian populations have identified single nucleotide polymorphisms (SNPs) conferring increased risk to autoimmune diseases. It is unclear whether these observations can apply to systemic lupus erythematosus (SLE) in China. An association study was performed on 395 SLE patients and 378 healthy controls recruited from the Chinese population, in which the IL12RB2 rs3790567, IKZF1 rs2366293, XKR6 rs4240671, TMEM39A rs1132200 and CSK rs34933034 polymorphisms were examined by Matrix Assisted Laser Desorption Time of Flight Mass Spectrometry. The frequency of the A allele of IL12RB2 rs3790567 was lower in the cases compared with the controls (24.8% vs 30.2%, P = 0.018) and significant difference among the AA, AG and GG genotypes of rs3790567 was detected between the SLE patients and healthy controls (P = 0.020). We also found a statistically significant difference in the dominant model (GG+AG vs AA, P = 0.008). There was no correlation between the genotypes and specific sub-phenotypes in the current cohort. Associations with IKZF1 rs2366293, XKR6 rs4240671, TMEM39A rs1132200 and CSK rs34933034 were also lacking (P > 0.05). The results supported the theory that IL12RB2 is associated with SLE in the Chinese population.

Regulatory circuit of PKM2/NF-κB/miR-148a/152-modulated tumor angiogenesis and cancer progression

Upregulation of the embryonic M2 isoform of pyruvate kinase (PKM2) emerges as a critical player in the cancer development and metabolism, yet the underlying mechanism of PKM2 overexpression remains to be elucidated. Here we demonstrate that IGF-1/IGF-IR regulates PKM2 expression by enhancing HIF-1α-p65 complex binding to PKM2 promoter. PKM2 expression is regulated by miR-148a/152 suppression. PKM2 directly interacts with NF-κB p65 subunit to promote EGR1 expression for regulating miR-148a/152 feedback circuit in normal cells, but not in cancer cells because of the DNA hypermethylation of miR-148a and miR-152 gene promoters. The silencing of miR-148a/152 contributes to the overexpression of PKM2, NF-κB or/and IGF-IR in some cancer cells. We show that disruption of PKM2/NF-κB/miR-148a/152 feedback loop can regulate cancer cell growth and angiogenesis, and is also associated with triple-negative breast cancer (TNBC) phenotype, which may have clinical implication for providing novel biomarker(s) of TNBC and potential therapeutic target(s) in the future.

Characterizations, relationship, and potential sources of outdoor and indoor particulate matter bound polycyclic aromatic hydrocarbons (PAHs) in a community of Tianjin, Northern China

Polycyclic aromatic hydrocarbons (PAHs) are among the most toxic air pollutants in China. However, because there are unsubstantial data on indoor and outdoor particulate PAHs, efforts in assessing inhalation exposure and cancer risk to PAHs are limited in China. This study measured 12 individual PAHs in indoor and outdoor environments at 36 homes during the non-heating period and heating period in 2009. Indoor PAH concentrations were comparable with outdoor environments in the non-heating period, but were lower in the heating period. The average indoor/outdoor ratios in both sampling periods were lower than 1, while the ratios in the non-heating period were higher than those in the heating period. Correlation analysis and coefficient of divergence also verified the difference between indoor and outdoor PAHs, which could be caused by high ventilation in the non-heating period. To support this conclusion, linear and robust regressions were used to estimate the infiltration factor to compare outdoor PAHs to indoor PAHs. The calculated infiltration factors obtained by the two models were similar in the non-heating period but varied greatly in the heating period, which may have been caused by the influence of ventilation. Potential sources were distinguished using a diagnostic ratio and a mixture of coal combustion and traffic emission, which are major sources of PAHs.

Association of PELI1 polymorphisms in systemic lupus erythematosus susceptibility in a Chinese population

Objective

Studies in animal models have indicated that Pellino 1 is involved in inflammatory and autoimmune diseases, such as systemic lupus erythematosus (SLE). The current study was designed to determine whether PELI1 confers genetic susceptibility to SLE in humans, as assessed in a Chinese Han population.

Methods

Blood samples were drawn from patients diagnosed with SLE and healthy volunteers. Three single nucleotide polymorphism (SNP) loci with a minor allele frequency of at least 0.05 were chosen to evaluate the correlation between PELI1 genotype and the incidence of SLE.

Results

There was a significant difference in the frequency distribution of the rs329497 allele between the SLE patients and the healthy controls (A vs. G; Bonferroni corrected p = 0.036, odds ratio = 0.75, 95% confidence interval = 0.60–0.94). No differences in the genotype and allele frequencies of other SNP loci were observed between the two groups. Furthermore, the alleles and genotypes of the three SNPs were not associated with lupus nephritis.

Conclusion

In the Chinese Han population, PELI1 SNPs may be associated with SLE susceptibility.

Latexin sensitizes leukemogenic cells to gamma-irradiation-induced cell-cycle arrest and cell death through Rps3 pathway

Leukemia is a leading cause of cancer death. Recently, the latexin (Lxn) gene was identified as a potential tumor suppressor in several types of solid tumors and lymphoma, and Lxn expression was found to be absent or downregulated in leukemic cells. Whether Lxn functions as a tumor suppressor in leukemia and what molecular and cellular mechanisms are involved are unknown. In this study, the myeloid leukemogenic FDC-P1 cell line was used as a model system and Lxn was ectopically expressed in these cells. Using the protein pull-down assay and mass spectrometry, ribosomal protein subunit 3 (Rps3) was identified as a novel Lxn binding protein. Ectopic expression of Lxn inhibited FDC-P1 growth in vitro. More surprisingly, Lxn enhanced gamma irradiation-induced DNA damages and induced cell-cycle arrest and massive necrosis, leading to depletion of FDC-P1 cells. Mechanistically, Lxn inhibited the nuclear translocation of Rps3 upon radiation, resulting in abnormal mitotic spindle formation and chromosome instability. Rps3 knockdown increased the radiation sensitivity of FDC-P1, confirming that the mechanism of action of Lxn is mediated by Rps3 pathway. Moreover, Lxn enhanced the cytotoxicity of chemotherapeutic agent, VP-16, on FDC-P1 cells. Our study suggests that Lxn itself not only suppresses leukemic cell growth but also potentiates the cytotoxic effect of radio- and chemotherapy on cancer cells. Lxn could be a novel molecular target that improves the efficacy of anti-cancer therapy.

Identification of sample donor by 24-plex short tandem repeat in a post-race equine plasma containing dexamethasone

BACKGROUND

Animal sport such as horseracing is tainted with drug abuse as are human sports. Treatment of racehorses on race day with therapeutic medications in most cases is banned, and thus, it is essential to monitor the illicit use of drugs in the racing horse to maintain integrity of racing, ensure fair competition and protect the health, safety and welfare of the horse, jockeys and drivers. In the event of a dispute over the identity of the sample donor, if the regulator can provide evidence that the DNA genotype profile of the post-race sample matched that of the alleged donor, then the potential drug violation case might be easily resolved without legal challenges.

CASE DESCRIPTION

We present a case study of a racehorse sample that tested positive for dexamethasone in a post-race plasma sample in Pennsylvania (PA) but the result was challenged by the trainer of the horse. Dexamethasone is a synthetic glucocorticoid widely used in the management of musculoskeletal problems in horses but its presence in the horse during competition is banned by the PA Racing Commissions. The presence of dexamethasone in the post-competition plasma sample was confirmed using liquid chromatography-tandem mass spectrometry. However, this finding was challenged by the trainer of the horse alleging that the post-race sample was not collected from his/her horse and thus petitioned the Commission to be absolved of any wrong-doing. To resolve the dispute, a DNA test was ordered by the PA Racing Commission to identify the correct donor of the dexamethasone positive sample. For this purpose, a 24-plex short tandem repeat analysis to detect 21 equine markers and three human markers was employed. The results indicated that all the samples tested had identical DNA profiles and thus, it was concluded that the samples were collected from the same horse and that the probability of drawing a false conclusion was approximately zero (1.5 × 10(-15)).

CONCLUSIONS

The plasma sample confirmed for the presence of dexamethasone was collected from the alleged horse.

High finesse pulsed optical cavity locking by tilt-locking technique

We report the Tilt-Locking (TL) technique applied to lock a laser in pulsed regime to a 28,000 high finesse Fabry-Perot cavity. Preliminary experimental results show that TL technique is comparable with the well-known Pound-Drever-Hall technique. This study is the first to implement the TL technique to lock a pulsed laser to a high-finesse optical cavity. Very high and stable coupling is obtained. The coupling rate is ~80%, and locking can last for more than 1 h. Furthermore, while previously published papers have focused on near field case, in this study we will give the error signal shape simulation for the far field case. We will show that for different types of error sources, the split photodiode transverse position can be carefully adjusted to obtain a symmetrical error signal. Our experimental results are consistent with the simulations.

Sensitive hydrophilic interaction liquid chromatography/tandem mass spectrometry method for rapid detection, quantification and confirmation of cathinone-derived designer drugs for doping control in equine plasma

RATIONALE

Cathinone derivatives are new amphetamine-like stimulants that can evade detection when presently available methods are used for doping control. To prevent misuse of these banned substances in racehorses, development of a liquid chromatography/tandem mass spectrometry (LC/MS/MS) method became the impetus for undertaking this study.

METHODS

Analytes were recovered via liquid-liquid extraction using methyl tert-butyl ether. Analyte separation was achieved on a hydrophilic interaction column using liquid chromatography and mass analysis was performed on a QTRAP mass spectrometer in positive electrospray ionization (ESI) mode with multiple reaction monitoring (MRM). Analyte identification was carried out by screening for a specified MRM transition. Quantification was conducted using an internal standard. Confirmation was performed by establishing a match in retention time and ion intensity ratios comparison.

RESULTS

The method was linear over the range 0.2-50 ng/mL. The specificity was evaluated by analysis of six different batches of blank plasma and those spiked with each analyte (0.2 ng/mL). The recovery of analytes from plasma at three different concentrations was >70%. The limits of detection, quantification and confirmation were 0.02-0.05, 0.2-1.0 and 0.2-10 ng/mL, respectively. The matrix effect was insignificant. The intra-day and inter-day precision were 1.94-12.08 and 2.58-13.32%, respectively.

CONCLUSIONS

The method is routinely employed in screening for the eleven analytes in post-competition samples collected from racehorses in Pennsylvania to enforce the ban on the use of these performance-enhancing agents in racehorses. The method is sensitive, fast, effective and reliably reproducible.