[The clinical and laboratory characteristics of congenital pyruvate kinase deficiency]

Clinical data of 19 patients with congenital pyruvate kinase deficiency were analyzed. Insufficient pyruvate kinase confirmed the diagnosis. Laboratory parameters of hemolysis were summarized. In cases of neonatal hyperbilirubinemia and unexplained hemolytic anemia, pyruvate kinase activity and next generation sequencing test may help the early diagnosis.

Neurotensin contributes to pediatric intestinal failure-associated liver disease via regulating intestinal bile acids uptake

Although the pathogenesis of intestinal failure (IF)-associated liver disease (IFALD) is uncertain, IF-associated cholestasis mediated by the combination of intestinal injury and parenteral nutrition (PN) can lead to disturbed hepatocyte bile acids (BA) homeostasis and cause liver damages. We here show that neurotensin (NT; also known as NTS) concentrations were lower compared to healthy matched controls. Patients with cholestasis [56.1 ng/L (9.7-154.7) vs. 210.4 ng/L (134-400.4), p < .001] had lower serum NT concentrations than others. In patients' ileum, the levels of NT mRNA were positively correlated with the apical sodium dependent bile acid transporter (ASBT) mRNA levels. In mice and in cultured intestinal cells, NT treatments stimulated the expression of ASBT and led to increase BA uptake via NT receptors (NTR1 and NTR3; also known as NTSR1and NTSR3). In conclusion, these findings directly link NT with BA homeostasis, which provide an insight into the complex mechanisms mediating the development of liver disease in pediatric patients with IF.

Development of a hard X-ray split-and-delay line and performance simulations for two-color pump-probe experiments at the European XFEL

A hard X-ray Split-and-Delay Line (SDL) under construction for the Materials Imaging and Dynamics station at the European X-Ray Free-Electron Laser (XFEL) is presented. This device aims at providing pairs of X-ray pulses with a variable time delay ranging from -10 ps to 800 ps in a photon energy range from 5 to 10 keV for photon correlation and X-ray pump-probe experiments. A custom designed mechanical motion system including active feedback control ensures that the high demands for stability and accuracy can be met and the design goals achieved. Using special radiation configurations of the European XFEL's SASE-2 undulator (SASE: Self-Amplified Spontaneous Emission), two-color hard x-ray pump-probe schemes with varying photon energy separations have been proposed. Simulations indicate that more than 10⁹ photons on the sample per pulse-pair and up to about 10% photon energy separation can be achieved in the hard X-ray region using the SDL.

Food withdrawal alters the gut microbiota and metabolome in mice

Food withdrawal as a health-enhancing measure has beneficial effects on aging, disease prevention, and treatment. However, the cellular and molecular mechanisms involving gut microbial changes and metabolic consequences resulting from food withdrawal have yet to be elucidated. In this study, we subjected lean and obese mice to a dietary intervention that consisted of a 4-d complete food withdrawal and an 8-d 50% food withdrawal, and we studied changes in cecal microbiome and host serum metabolome. The abundance of potentially pathogenic Proteobacteria was decreased and Akkermansia muciniphila was elevated by food withdrawal in mice fed a high-fat diet (HFD). Meanwhile, food withdrawal decreased the abundance of metabolites in branched chain amino acid, lipid, and free fatty acid metabolisms in host serum, more so in HFD mice than in normal mice. Microbial predicted function also showed that food withdrawal decreased the abundance of microbes associated with predicted diseases in the HFD group but not in the normal chow group. Correlation between the microbiome data and metabolomics data revealed a strong association between gut microbial and host metabolic changes in response to food withdrawal. In summary, our results showed that food withdrawal was safer and more metabolically beneficial to HFD-induced obese mice than to normal lean mice, and the beneficial effects were primarily derived from the changes in gut microbiota, which were closely associated with the host metabolome.-Zheng, X., Zhou, K., Zhang, Y., Han, X., Zhao, A., Liu, J., Qu, C., Ge, K., Huang, F., Hernandez, B., Yu, H., Panee, J., Chen, T., Jia, W., Jia, W. Food withdrawal alters the gut microbiota and metabolome in mice.

Palliative care in heart failure : A meta-analysis of randomized controlled trials

BACKGROUND

Palliative care can play an important role in the management of heart failure. We conducted a systematic review and meta-analysis to compare the efficacy and safety of palliative care in patients with heart failure.

METHODS

PubMed, Embase, Web of Science, EBSCO, and the Cochrane Library databases were systematically searched. Randomized controlled trials (RCTs) on the impact of palliative care on heart failure were included. Two investigators independently searched the articles, extracted data, and assessed the quality of included studies. The primary outcome was mortality.

RESULTS

Seven RCTs were included in the meta-analysis. Compared with usual care for heart failure, palliative care was associated with a significantly increased quality of life (standardized mean difference = 1.46; 95% confidence interval [CI] = 0.12 to 2.79; p = 0.03) and reduced depression scores (standardized mean difference = -0.62; 95% CI = -0.99 to -0.25; p = 0.03), but demonstrated no impact on mortality (risk ratio [RR] = 1.28; 95% CI = 0.86 to 1.92; p = 0.22) and rehospitalization (RR = 0.84; 95% CI = 0.66 to 1.07; p = 0.16).

CONCLUSION

Palliative care can improve the quality of life and reduce the occurrence of depression in patients with heart failure.

[The life span of red blood cell in patients with severe/very severe aplastic anemia]

Objective: To explore the life span of red blood cells (RBC) in patients with severe/very severe aplastic anemia (SAA/VSAA). Methods: Clinical data of 128 SAA/VSAA patients from November 2016 to April 2017 were retrospectively analyzed, and 13 healthy volunteers in the same period was used as normal control. The endogenous Breath Carbon Monoxide (CO) test was used to detect the life span of RBC in SAA/VSAA patients, and the effect of immunosuppressive therapy (IST) on the life span of RBC in these patients was explored. Results: The mean life span of RBC in 51 untreated SAA/VSAA patients was (50.69±21.43) d, which was significantly shorter than that in normal controls[(111.85±31.55) d](t=-6.611, P<0.001). The mean life span of RBC in 77 patients treated with IST was (87.14±39.28) d. The mean life span of RBC in complete responses (CR), hematologic response (HR) and non-response (NR) patients were (106.15±32.12) d, (92.00±38.60) d and (50.44±21.56) d, respectively. The life span of RBC in patients with HR was significantly longer than that in newly diagnosed and NR patients (t=7.430, P<0.001; t=4.846, P=0.002), which was similar to that in the normal controls (t=-1.743,P=0.085). There was no statistical significance between CR patients and the normal controls in the mean life span of RBC (t=-0.558, P=0.579). No factor affecting the RBC life span was found in univariate logistical regression analyses in the newly diagnosed SAA/VSAA patients. The serum levels of IL-2R and IL-6 were much lower in HR patients than NR patients[IL-2R: 4.3×105 U/L vs 6.5×105 U/L, z=-2.733, P=0.006; IL-6: 2.6 (2.0-17.7) ng/L vs 6.1 (2.0-14.4) ng/L, z=-2.968, P=0.003]. Of the 51 newly diagnosed patients, 38 received IST and their 3-month curative effect was evaluated. Receiver operator characteristics (ROC) curve was used to analyze the predictive effect of RBC life span of untreated patients on the efficacy of IST before treatment. The cut-off point was 60 days with sensitivity of 37.5% and specificity of 86.4%. In 9 cases with life span of RBC>60 d before IST, 6 cases acquired HR, while in 29 cases with life span of RBC ≤ 60 d before IST, 10 cases acquired HR, the difference was not statistically significant (P=0.128). Conclusion: The life span of RBC in SAA/VSAA patients was shortened, which can be improved even recovered to the normal after IST. Elevated cytokines might play a role in the pathophysiology of the shortened RBC life span in SAA/VSAA.

PHB2 interacts with LC3 and SQSTM1 is required for bile acids-induced mitophagy in cholestatic liver

Mitophagy is a major pathway for clearance of injured mitochondria. However, whether mitophagy is involved in the cholestasis-induced damages of hepatic mitochondria remains unknown. We here aimed to investigate the molecular links between cholestasis and hepatic mitophagy. We show that mitophagy is increased significantly in livers of biliary atresia (BA) that is cholestatic disease in infants. The mitochondrial-toxicity bile acids treatment increases the activities of mitophagy in hepatocytes. Mechanistically, we find that the prohibitin 2 (PHB2) is crucial for cholestasis-mediated mitophagy in vitro. On the one hand, PHB2 binds the autophagosomal membrane-associated protein LC3 upon injured mitochondria via an LC3-interaction region domain. On the other hand, PHB2 forms a ternary protein complex with sequestosome 1 (SQSTM1) and LC3, leading to loading of LC3 onto the damaged mitochondria. Altogether, our study suggests that PHB2 is required for cholestasis-induced mitophagy via LC3 onto the injured mitochondria.

[Progress in diagnosis and treatment of radioactive iodine-refractory differentiated thyroid carcinoma]

The radioactive iodine-refractory differentiated thyroid carcinoma (RIR-DTC) is a complex process that involves multiple genetic changes and multiple signaling pathways.Radionuclide imaging, genomics and proteomics are effective to clarify the mechanism and helpful in clinical diagnosis and therapy.The treatment of RIR-DTC includes the removal of distant metastases, drug therapy, external radiotherapy and radiofrequency ablation.This review mainly focuses on the pathogenesis, diagnosis and treatment of RIR-DTC.

[Value of non-invasive models of liver fibrosis in judgment of treatment timing in chronic hepatitis B patients with ALT < 2×upper limit of normal]

Objective: To investigate the value of non-invasive liver fibrosis models, FIB-4, S index, aspartate aminotransferase to platelet ratio index(APRI), globulin-platelet(GP)model, aspartate aminotransferase/platelet/gamma-glutamyl transpeptidase/alpha-fetoprotein(APGA), and platelet/age/phosphatase/alpha-fetoprotein/aspartate aminotransferase(PAPAS), in the diagnosis of marked liver fibrosis in chronic hepatitis B(CHB)patients with ALT < 2×upper limit of normal(ULN), as well as treatment timing for this population. Methods: A total of 389 CHB patients with ALT < 2×ULN who were admitted to Beijing Ditan Hospital and whose treatment timing was difficult to judge were enrolled. Transdermal liver biopsy was performed to obtain pathological results, and routine serological tests were performed, including routine blood test, serum biochemical parameters, hepatitis B virus(HBV)markers, and HBV DNA. According to liver pathology, the patients were divided into non-marked liver fibrosis group(S < 2)with 324 patients and marked liver fibrosis group(S≥2)with 65 patients. The non-invasive models for predicting liver fibrosis was established with reference to original articles. SPSS 19.0 software was used for statistical analysis, and the receiver operating characteristic(ROC)curve was used to compare the value of different non-invasive models in predicting marked liver fibrosis in this population. Results: All the non-invasive models had a certain diagnostic value for liver fibrosis degree in these patients, and the areas under the ROC curve for APRI, FIB-4, APGA, S index, PAPAS, and GP model were 0.718, 0.691, 0.758, 0.729, 0.673, and 0.691, respectively. APGA had the largest area under the ROC curve(0.758, 95% CI 0.673-0.844), and gamma-glutamyl transpeptidase was significantly positively correlated with liver fibrosis degree. Conclusion: The non-invasive models of liver fibrosis can identify marked liver fibrosis in CHB patients with ALT < 2×ULN in whom it is difficult to judge treatment timing and help to determine treatment timing for them. APGA model has the highest value and can reduce the need for liver biopsy to the certain degree.

Alterations in intestinal microbiota relate to intestinal failure-associated liver disease and central line infections

BACKGROUND

The gut microbiota plays a vital role in modulating the metabolic and immune functions of the intestines. We aimed to analyze the dysbiosis of microbiota in infants with short bowel syndrome (SBS) with different complications.

PROCEDURE

We included 26 fecal samples from 18 infants with SBS during parenteral nutrition. The samples were categorized into three groups: asymptomatic, parenteral nutrition-associated liver disease (PNALD), and central line-associated bloodstream infection (CLABSI). Seven healthy infants were enrolled as controls. Fecal microbiota, secretory IgA, calprotectin, bile acids, and short chain fatty acids were detected.

RESULTS

The bacterial diversity of the Asymptomatic and Control Groups was significantly higher than that in the PNALD and CLABSI Groups. Proteobacteria was the most pronounced phylum in the PNALD and CLABSI Groups. Decreased acetate was observed in all SBS samples; however, fecal secretory IgA and calprotectin and the proportion of primary and secondary bile acids did not differ from those in healthy controls.

CONCLUSIONS

Marked alterations of the intestinal microbiota with decreased level of acetate were shown in SBS patients compared with healthy controls. Over-abundance of Proteobacteria (especially Enterobacteriaceae) was found in the samples from the PNALD and CLABSI Groups.

LEVEL OF EVIDENCE

Prognosis Study, Level I.

[Correlation of the degree of band 3 protein absence on erythrocyte membrane by eosin-5'-maleimide binding test and clinical phenotype in hereditary spherocytosis]

目的

探讨伊红-5′-马来酰亚胺标记的流式细胞术（EMA结合试验）检测红细胞膜骨架带3蛋白缺失程度与遗传性球形红细胞增多症（hereditary spherocytosis，HS）临床表现型的关系。

方法

分析258例未行脾切除术治疗的HS患者临床和实验室特征，评估EMA结合试验结果与贫血程度、溶血和造血代偿参数的关系。

结果

258例HS患者中，男128例，女130例，中位年龄23（2~70）岁。代偿性溶血91例、轻度贫血53例、中度贫血78例、重度贫血36例。EMA结合试验荧光强度减低中位数为29.97%（16.09%~47.34%），平均数为（29.70±6.28）%。荧光强度减低程度与红细胞平均体积呈负相关（r=−0.343，P<0.001），与红细胞平均血红蛋白浓度呈正相关（r=0.223，P<0.001），与网织红细胞比例（r=−0.015，P=0.813）和绝对值（r=0.080，P=0.198）均无明显相关性，与血清间接胆红素水平无明显相关（r=−0.009，P=0.902），与HGB水平无明显相关性（r=−0.067，P=0.280）。按EMA标记缺失程度四分位区间分组，不同EMA标记缺失组与HS贫血严重程度分组亦无明显相关性（C=0.150，P=0.746）。

结论

EMA结合试验结果与HS贫血程度无关。

Association of cytokine gene polymorphisms (IL‑6, IL‑12B, IL‑18) with Behcet's disease : A meta-analysis

PURPOSE

This study aims to investigate the association of cytokine gene polymorphisms with the risk of Behcet's disease (BD) via comprehensive meta-analysis.

METHODS

The Embase and PubMed databases covering the period from the earliest possible year to May 2015 were searched. A total of 13 eligible articles including 2,065 BD patients and 1,559 controls were recruited. Odds ratios (ORs) and 95 % confidence intervals (CIs) were used to assess the strength of the associations. Potential publication bias was evaluated using Egger's linear regression test.

RESULTS

Meta-analysis indicated associations between IL‑6 rs1800795, IL‑12B rs3212227, and IL‑18 rs1946518 in all study subjects: IL‑18 rs1946518 in the dominant model (IL‑18 rs1946518: OR = 0.48, 95 % CI: 0.34-0.70, P = 0.000) and the homozygote model (IL‑18 rs1946518: OR = 0.40, 95 % CI: 0.25-0.65, P = 0.000); and IL‑6 rs1800795 and IL‑12B rs3212227 in the dominant model (IL‑6 rs1800795: OR = 0.53, 95 % CI: 0.39-0.72, P = 0.000; IL‑12B rs3212227: OR = 1.26, 95 % CI: 1.06-1.48, P = 0.007; IL‑18 rs1946518: OR = 0.46, 95 % CI: 0.33-0.65, P = 0.000). No significant evidence for associations of IL‑18 rs187238 polymorphisms with BD susceptibility was detected.

CONCLUSION

In summary, this meta-analysis finds that IL‑6 rs1800795 and IL‑18 rs1946518 polymorphisms decrease the risk of BD. However, IL‑12B rs3212227 increases BD susceptibility. Further large-scale investigation of this association is necessary.

Interactions between Th1 cells and Tregs affect regulation of hepatic fibrosis in biliary atresia through the IFN-γ/STAT1 pathway

Regulatory T cells (Tregs) and CD4⁺ T helper (Th) cells have important roles in bile duct injury of biliary atresia (BA). However, their impacts on liver fibrosis are undefined. Between 2013 and 2016, 146 patients with various stages of BA were enrolled in this study. Peripheral blood, liver biopsy and lymph node samples were collected. Flow cytometry, magnetic cell sorting and immunostaining were used to characterize lymphocytes from BA patients. Deficiency of Tregs was observed along with increased Th1, Th2 and Th17 frequencies in the peripheral blood and livers of BA patients. The levels of peripheral and intrahepatic Th1 cells positively correlated with the stage of liver fibrosis. Furthermore, Th1 cells were located in close proximity to activated hepatic stellate cells (HSCs) and areas of fibrosis in BA livers. In culture, Th1 cells accelerated the proliferation and secretion of profibrogenic markers of HSCs through the IFN-γ/STAT1 pathway. Of note, Tregs blocked the Th1-stimulated effects on HSCs by inhibiting Th1-induced activation of STAT1. Consistent with the results of in vitro study, intrahepatic IFN-γ/STAT1 levels increased in relation to the severity of liver fibrosis in BA patients, and the altered balance between MMP2 and TIMP1 expressions in livers may contribute to increased deposition of extracellular matrix and fibrosis. Finally, to identify the effects of Th1 cells on Tregs, we demonstrated that Th1 cells upregulated the proportion of aTreg cells by secreting IFN-γ cytokine. Thus, aberrant Th1 immune responses in BA promote the proliferation and secretion of HSCs through the IFN-γ/STAT1 pathway. The regulation of HSCs by the interactions between Tregs and Th1 cells might be part of the mechanism underlying progressive liver fibrosis and may be a suitable target for therapy.

Refractive index and temperature sensitivity characterization of excessively tilted fiber grating

We have investigated experimentally and numerically the temperature and refractive index (RI) sensitivity characteristics of excessively tilted fiber gratings (Ex-TFGs) in detail. Both results have shown that the temperature and RI sensitivities of Ex-TFGs are mode order dependent. For temperature sensitivity, the higher order cladding mode of Ex-TFG exhibited lower temperature sensitivity, quantitatively, the temperature sensitivities of TM cladding modes at the resonance wavelength around 1550nm are 9pm/°C, 6.8pm/°C, 5.6pm/°C and, 4pm/°C for cladding mode 28th, 31st, 35th, 40th, respectively, indicating the overall temperature sensitivity of Ex-TFGs were lower than that of normal FBGs. The SRI sensing results have shown that the RI sensitivity of Ex-TFG at the special index value could be improved by choosing the cladding mode with effective index close to the refractive index of the detecting medium. The SRI sensitivities at the effective mode index were 2250nm/RIU at 1.408, 864nm/RIU at 1.395, 1536nm/RIU at 1.380 and 1360nm/RIU at 1.355, for the cladding mode of 28th, 31st, 35th, 43rd, respectively. The experimental results have also shown the SRI sensitivity of Ex-TFG was increasing with increasing of the resonance wavelength.

Variants in Pharmacokinetic Transporters and Glycemic Response to Metformin: A Metgen Meta-Analysis

Therapeutic response to metformin, a first-line drug for type 2 diabetes (T2D), is highly variable, in part likely due to genetic factors. To date, metformin pharmacogenetic studies have mainly focused on the impact of variants in metformin transporter genes, with inconsistent results. To clarify the significance of these variants in glycemic response to metformin in T2D, we performed a large-scale meta-analysis across the cohorts of the Metformin Genetics Consortium (MetGen). Nine candidate polymorphisms in five transporter genes (organic cation transporter [OCT]1, OCT2, multidrug and toxin extrusion transporter [MATE]1, MATE2-K, and OCTN1) were analyzed in up to 7,968 individuals. None of the variants showed a significant effect on metformin response in the primary analysis, or in the exploratory secondary analyses, when patients were stratified according to possible confounding genotypes or prescribed a daily dose of metformin. Our results suggest that candidate transporter gene variants have little contribution to variability in glycemic response to metformin in T2D.

[Comparison of efficacy and safety of two different dose of recombinant human thrombopoietin regimens in severe aplastic anemia patients with immunosuppressive therapy]

目的

比较不同重组人TPO（rhTPO）方案联合免疫抑制剂治疗重型再生障碍性贫血（SAA）的近期疗效。

方法

回顾性分析接受一线免疫抑制治疗（IST）的61例成人SAA初诊患者资料，对比分析18例IST联合rhTPO每日1次（连续组）与43例IST联合rhTPO隔日1次（间日组）患者的疗效差异。

结果

两组患者在IST前基础临床特征差异无统计学意义。IST后3个月和6个月进行疗效评估，连续组与间日组患者总体血液学反应率比较差异无统计学意义（3个月：50.0%对51.2%，P= 0.934；6个月：77.8%对69.8%，P=0.525）。连续组IST后3个月良好血液学反应率明显高于间日组（38.9%对9.3%，P=0.011）。rhTPO应用后4周和8周两组脱离红细胞输注率差异无统计学意义（4周：22.2%对18.6%，P=0.736; 8周：55.6%对46.5%，P=0.519），而治疗后8周脱离血小板输注率连续组明显高于间日组（88.9%对48.8%，P=0.003）。每日连续应用rhTPO治疗并不增加不良反应事件的发生。

结论

每日1次较隔日1次应用rhTPO促进SAA造血恢复和减少血小板输注依赖更为有效。

[Hepatitis-associated aplastic anaemia: clinical characteristics and immunosuppressive therapy outcomes]

目的

分析肝炎相关再生障性贫血（HAAA）临床特征，评价其免疫抑制治疗（IST）疗效及生存状况。

方法

回顾性分析944例接受IST的重型／极重型AA（SAA/VSAA）患者，比较41例HAAA患者与年龄、造血衰竭程度相匹配的123例特发性AA（IAA）临床特征、血液学反应率、长期生存率及克隆性演变情况。

结果

944例SAA/VSAA患者中HAAA 41例（4.34%），HAAA患者中VSAA所占比例明显高于IAA患者（65.9％对39.4%，P=0.001）。HAAA与匹配的IAA比较，患者感染发生率差异无统计学意义，但感染控制所需时间明显延长[21 (4~100) d对13 (3~139) d，P=0.048]。HAAA患者CD3⁺、CD3⁺CD4⁺、CD3⁺CD8⁺ T淋巴细胞绝对值及CD4⁺/CD8⁺细胞比值均明显低于IAA患者，而CD3⁺ CD8⁺ T淋巴细胞比例明显高于IAA患者，差异均有统计学意义。HAAA与IAA患者IST后3个月（34.1％对34.1%，P=1.000）、6个月（56.1％对53.7%，P=0.787）及12个月（73.2％对68.3%，P=0.558）血液学反应率差异无统计学意义，两组患者预期5年总生存（OS）率、无事件生存（EFS）率比较差异均无统计学意义（OS率：90.0％对87.1%，P=0.700；EFS率：71.9％对62.4%，P=0.450）。

结论

HAAA少见，造血衰竭更为严重，感染相对难以控制，采用标准IST方案治疗可获得与IAA患者相当的疗效。

Evidence for the transition from primary to peritectic phase growth during solidification of undercooled Ni-Zr alloy levitated by electromagnetic field

The Ni_83.25Zr_16.75 peritectic alloy was undercooled by electromagnetic levitation method up to 198 K. The measured dendritic growth velocity shows a steep acceleration at a critical undercooling of ΔT_crit = 124 K, which provides an evidence of the transition of the primary growth mode from Ni₇Zr₂ phase to peritectic phase Ni₅Zr. This is ascertained by combining the temperature-time profile and the evolution of the solidified microstructures. Below the critical undercooling, the solidified microstructure is composed of coarse Ni₇Zr₂ dendrites, peritectic phase Ni₅Zr and eutectic structure. However, beyond the critical undercooling, only a small amount of Ni₇Zr₂ phase appears in the solidified microstructure. The dendritic growth mechanism of Ni₇Zr₂ phase is mainly governed by solute diffusion. While, the dendritic growth mechanism of Ni₅Zr phase is mainly controlled by thermal diffusion and liquid-solid interface atomic attachment kinetics.

Spatial and Temporal Dependence of Diffusion in Polystyrene Thin Films on Silicon and Carbon Surfaces

The strong inhibition of chain diffusion in thin polystyrene (PS) films has been observed near an attractive silicon surface, and diffusion remains inhibited out to distances of several radii of gyration from the surface. The present study seeks to determine the time dependence of the diffusion coefficient, and to examine the effect of a carbon surface on this diffusion. The sputter-deposited carbon surface may serve as a model for carbon-black particles employed in nanocomposites, which have recently been observed to reduce diffusion throughout a nanocomposite layer. The experiments employed a thin (∼15 nm) deuterated polystyrene (dPS) marker layer sandwiched between two normal PS layers. Deuterium profiles were monitored in the annealed samples by secondary ion mass spectrometry. Strong segregation was observed at the silicon surface, but was inhibited at the carbon surface, allowing the diffusion behaviour to be studied in the latter case over longer annealing times. A finite-element computer program was developed to fit the observed diffusion profiles. The variation of the diffusion coefficient with depth is shown to be consistent with previous results, and diffusion is comparable at both the carbon and silicon surfaces. The diffusion coefficient decreases roughly in proportion to t−1/2, and is discussed in the context of reptation theory.

Contribution of Common Variants in GABRG2, RELN and NRG3 and Interaction Networks to the Risk of Hirschsprung Disease

BACKGROUND

Hirschsprung disease (HSCR) is a complex and heterogeneous disorder, characterized by a deficit in enteric nervous system. Genome-wide studies implied GABRG2, RELN and NRG3 might be involved in HSCR etiology. Here, we aimed to assess genetic variants in GABRG2, RELN and NRG3 that may confer susceptibility to HSCR and explore genetic interaction networks in HSCR.

METHODS

Using a strategy that combined case-control study and gene-gene interaction analysis with the MassArray system, we evaluated 24 polymorphisms within GABRG2, RELN and NRG3 in 104 HSCR cases and 151 normal controls of Han Chinese origin.

RESULTS

We observed that seven polymorphisms showed statistically significant differences between HSCR subjects and normal controls. For each of the three genes, the haplotypes which combined eight markers were the most significant. Moreover, we recruited SNPsyn, GO enrichment and MDR analyses to interrogate the interactions among GABRG2, RELN, NRG3 and our previous identified PTCH1 gene. Significant interaction networks were found among GABRG2, RELN, and PTCH1.

CONCLUSION

We provide a first indication that common variants of GABRG2, RELN and NRG3 and the GABRG2-RELN-PTCH1 interaction networks might confer altered susceptibility to HSCR in the Han Chinese population, suggesting a potential mechanism underlying HSCR pathogenesis.

Investigation of the size effect for photonic crystals

Three types of photonic crystal (PC) thin films have been prepared for the investigation of their deformation behaviors by nanoindentation tests at the microscale and nanoscale. Each type of PC thin film was composed of poly(methyl methacrylate) (PMMA) nanoparticles with a uniform size. Another type of thin film was prepared by assembling nanoparticles with three different sizes. It was exciting to observe that the hardness and Young's modulus were significantly improved (more than 15 times) in well-ordered PC thin films than disordered ones. Furthermore, size-dependent mechanical properties were observed for the three types of PCs. Such a size effect phenomenon can be attributed to the special polycrystalline material having a periodical face-centered cubic structure of PC thin films. Furthermore, the indentation size effect that shows that the indentation hardness decreases with an increasing indentation depth has also been observed for all four types of thin films. It is conjectured that the application of the PC structure to other functional materials may enhance their mechanical properties.

Glucocorticoid treatment alters systemic bile acid homeostasis by regulating the biosynthesis and transport of bile salts

BACKGROUND

Dysregulation of systemic bile acid homeostasis can lead to cholestatic liver diseases and metabolic syndromes. As important anti-inflammatory and immunosuppressive drugs, synthetic glucocorticoids (GCs) are used to treat several cholestatic disorders, including biliary atresia (BA), because of their effects on the regulation of bile acid metabolism. However, the molecular mechanisms that underlie GCs regulation of bile acid homeostasis remain unclear.

AIMS

To provide a mechanistic basis for the effects of GCs on bile acid homeostasis.

METHODS

Male rats were treated with methylprednisolone for 7 days with slow-release osmotic pumps under physiological and cholestatic status that was induced by bile duct ligation (BDL). Expression of glucocorticoid receptor (GR) and genes related to bile acid metabolism was investigated using western blotting, qRT-PCR and immunohistochemistry.

RESULTS

We show here that sustained treatment with GCs in rats disrupts the normal changes in systemic bile acid distribution by elevating plasma bile acid levels and reducing faecal bile acid loss. Treatment with GCs stimulated bile acid absorption in the ileum by increasing expression of the apical sodium-dependent bile acid transporter (Asbt). Concomitantly, administration of GCs enhanced liver bile acid uptake by increasing the expression of the major hepatocyte basolateral bile transporter (Ntcp). The reduced expression of a bile acid synthesis rate-controlling enzyme, Cyp7a1, suggests that treatment with GCs suppressed hepatic bile acid synthesis.

CONCLUSION

Our study provides evidence that GCs can increase enterohepatic bile acid circulation through regulation of the biosynthesis and transport of bile salts, which suggests that plasma bile acid levels should be monitored during treatment with GCs in patients with BA.

MicroRNA-34a inhibits cell proliferation and induces cell apoptosis of glioma cells via targeting of Bcl-2

Glioblastoma is a highly malignant brain tumor, characterized by the poor prognosis and high recurrence rates. Despite therapeutic strategies including surgery, radiotherapy and chemotherapy, the median survival of patients is only 14.6 months. MicroRNAs (miRNAs) have been considered as a novel type of gene regulator. Previous studies have demonstrated that the expression of miRNA‑34a (miR‑34a) is significantly associated with the grade and prognosis of glioma. However, the exact function of miR‑34a on glioma progression and underlying mechanisms remain to be elucidated. The present study investigated the function of miR‑34a in U87 human glioma cells by exogenously transfecting cells with an miR‑34a mimic. Overexpression of miR‑34a inhibited proliferation, and induced apoptosis of U87 cells. The current study also demonstrated that B‑cell lymphoma 2 (Bcl‑2) was the target gene of miR‑34a, as demonstrated by luciferase assays. Furthermore, restoring the expression of Bcl‑2 was indicated to partially block the miR‑34a‑induced apoptosis. Thus, data from the present study identified miR‑34a as a tumor suppressor in glioma by, at least partially, targeting Bcl‑2. This may provide future novel diagnostic and therapeutic strategies for human glioma.

A self-assembling β-peptide hydrogel for neural tissue engineering

We report a new class of β-peptide based hydrogel for neural tissue engineering. Our β-peptide forms a network of nanofibres in aqueous solution, resulting in a stable hydrogel at physiological conditions. The hydrogel shows excellent compatibility with neural cells and provides a suitable environment for cells to adhere and proliferate.

In Vitro Chromatin Assembly: Strategies and Quality Control

Chromatin accessibility is modulated by structural transitions that provide timely access to the genetic and epigenetic information during many essential nuclear processes. These transitions are orchestrated by regulatory proteins that coordinate intricate structural modifications and signaling pathways. In vitro reconstituted chromatin samples from defined components are instrumental in defining the mechanistic details of such processes. The bottleneck to appropriate in vitro analysis is the production of high quality, and quality-controlled, chromatin substrates. In this chapter, we describe methods for in vitro chromatin reconstitution and quality control. We highlight the strengths and weaknesses of various approaches and emphasize quality control steps that ensure reconstitution of a bona fide homogenous chromatin preparation. This is essential for optimal reproducibility and reliability of ensuing experiments using chromatin substrates.

Emergence of pan-resistance in KPC-2 carbapenemase-producing Klebsiella pneumoniae in Crete, Greece: a close call

OBJECTIVES

KPC-2-producing Klebsiella pneumoniae (KPC-KP) ST258 has been rapidly expanding and is often associated with serious nosocomial infections. Last-line antibiotics such as colistin and tigecycline often remain the only treatment option. We describe here the evolving genetic background of KPC-KP isolates in Crete, Greece.

METHODS

We tested the antibiotic susceptibility of 34 clinical isolates from patients hospitalized in 2010 and 2013-14. Whole-genome sequences of these isolates were analysed for acquired resistance genes and gene mutations.

RESULTS

All KPC-KP isolates belonged to ST258 with the exception of one ST147 isolate. From 2014, 26% of isolates were non-susceptible to all antibiotics, compared with 0 of 11 isolates from 2010. Colistin resistance was associated with mutations in mgrB, which was present in 61% of isolates from 2014. Core-genome MLST analysis showed that pan-resistant isolates were closely related and appeared in two separate clusters.

CONCLUSIONS

KPC-KP is rapidly evolving to pan-resistance in Crete. We identified molecular resistance markers for pan-resistant isolates and showed that core-genome MLST is a promising tool for molecular fingerprinting of KPC-KP ST258.

A genome-wide association study suggests an association of Chr8p21.3 (GFRA2) with diabetic neuropathic pain

Background

Neuropathic pain, caused by a lesion or a disease affecting the somatosensory system, is one of the most common complications in diabetic patients. The purpose of this study is to identify genetic factors contributing to this type of pain in a general diabetic population.

Method

We accessed the Genetics of Diabetes Audit and Research Tayside (GoDARTS) datasets that contain prescription information and monofilament test results for 9439 diabetic patients, among which 6927 diabetic individuals were genotyped by Affymetrix SNP6.0 or Illumina OmniExpress chips. Cases of neuropathic pain were defined as diabetic patients with a prescription history of at least one of five drugs specifically indicated for the treatment of neuropathic pain and in whom monofilament test result was positive for sensory neuropathy in at least one foot. Controls were individuals who did not have a record of receiving any opioid analgesics. Imputation of non‐genotyped SNPs was performed by IMPUTE2, with reference files from 1000 Genomes Phase I datasets.

Results

After data cleaning and relevant exclusions, imputed genotypes of 572 diabetic neuropathic pain cases and 2491 diabetic controls were used in the Fisher's exact test. We identified a cluster in the Chr8p21.3, next to GFRA2 with a lowest p‐value of 1.77 × 10⁻⁷ at rs17428041. The narrow‐sense heritability of this phenotype was 11.00%.

Conclusion

This genome‐wide association study on diabetic neuropathic pain suggests new evidence for the involvement of variants near GFRA2 with the disorder, which needs to be verified in an independent cohort and at the molecular level.