Association of K121Q Polymorphism in Ectonucleotide Pyrophosphatase/Phosphodiesterase 1 with Clinical Characteristics of Metabolic Syndrom

PURPOSE

This study aimed to investigate the relationships between K121Q polymorphism of ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) and clinical characteristics of metabolic syndrome (MS) in northern Han Chinese.

MATERIALS AND METHODS

A total of 209 MS patients and 248 healthy controls of Han ethnic group in northern China were enrolled in this study. Various clinical parameters of these participants were firstly collected and compared, including age, sex, body mass index (BMI), waist circumference (WC), systolic and diastolic blood pressures (SBP/DBP), fasting plasma glucose (FPG), fasting insulin (FINS), homeostasis model assessment of insulin resistance index (HOMA-IR), total cholesterol (TC), triglycerides (TG), high-density and low-density lipoprotein cholesterol (LDL-C/HDL-C). Then K121Q polymorphism of ENPP1 was determined by PCR and restriction enzyme digestion, and its relations with related clinical parameters were finally analyzed.

RESULTS

When compared with healthy controls, the age, BMI, WC, SBP, DBP, FPG, FINS, HOMA-IR, TC, TG and LDL-C were all significantly increased in MS patients (P<0.001). The allele frequencies of K and Q alleles in ENPP1 were 90.19% and 9.81% in MS patients, and 91.73% and 8.27% in healthy controls, respectively. Besides, only BMI and WC were significantly increased in MS patients carrying Q alleles (P<0.001), while no significant relations were found between K121Q polymorphism and other clinical parameters in either MS patients or healthy controls.

CONCLUSION

The K121Q polymorphism of ENPP1 showed no direct correlation with MS, although it showed some correlation with BMI and WC in MS patients.

Analysis of uridine diphosphate glucuronosyl transferase 1A1 gene mutations in neonates with unconjugated hyperbilirubinemia

This study was carried out to analyze uridine diphosphate (UDP)-glucuronosyltransferase 1A1 (UGT1A1) gene mutations in neonates with unconjugated hyperbilirubinemia, from two different ethnic groups. Polymerase chain reaction and gene sequencing were used to analyze the differences in genotypes and allele frequencies of different gene mutations among the ethnic groups; this was followed by checking their correlation with the serum bilirubin level and the occurrence of unconjugated hyperbilirubinemia in neonates. Our results reveal that the UGT1A1 mutant genotype, 211G>A, is distributed differently in the case vs control groups, as well as in the Zhuang vs Han ethnic groups. Moreover, this difference is statistically significant (P < 0.05); the total serum bilirubin (TSB) and unconjugated bilirubin (UCB) levels in patients carrying the single homozygous mutation, 211G>A, were markedly higher than that in patients without the mutation (P < 0.05). Furthermore, the TSB and UCB levels were significantly different between patients carrying single or compound 211G>A heterozygous mutation, (TA)6/7, and 1941C>G/2042C>G heterozygous mutation, and patients without mutation (P > 0.05). Our findings suggest that the 211G>A mutation in the first exon may be a risk factor for unconjugated hyperbilirubinemia in Zhuang and Han neonates. The serum bilirubin levels seem to be affected by the homozygosity or heterozygosity of the UGT1A1 gene mutation; 211G>A homozygous mutation is an important factor that causes a rise in bilirubin in neonates with unconjugated hyperbilirubinemia.

Dietary Influence on Calcitropic Hormones and Adiposity in Caucasian and African American Postmenopausal Women Assessed by Structural Equation Modeling (SEM)

OBJECTIVES

To examine differences in hydroxycholecalciferol (25(OH)D) and parathyroid hormone (PTH) concentrations between Caucasian and African American (AA) postmenopausal women, as well as the effects of dietary calcium, protein and vitamin D intakes on 25(OH)D, PTH, and body adiposity using structural equation modeling (SEM).

DESIGN

Population-based prospective cohort study.

SETTING

Academic research using the baseline data from two longitudinal studies. Participants Included n=113 Caucasian and n=40 African American, postmenopausal women who completed the baseline data collection and met inclusion criteria (dietary calcium intake <900 mg/day and being generally healthy) between 2006 and 2010.

MAIN OUTCOME

Dietary intake of calcium and vitamin D, assessed by dietary records, were examined in relation to calcitropic hormones concentrations and adiposity markers. Independent t-tests, confirmatory factor analysis, SEM and multi-group analyses were conducted to examine the aforementioned relationships as well as group differences among hormones, dietary intake, anthropometrics, age and other factors.

RESULTS

Dietary calcium and protein intakes were significantly lower in AA women. Years since menopause were significantly higher in AA compared to Caucasian women. PTH and 25(OH)D levels were significantly lower in AA compared to Caucasian women. Dietary calcium and protein intakes did not influence body adiposity in either group of women. Dietary vitamin D had minimal indirect (via 25(OH)D levels) influence on adiposity.

CONCLUSION

The study confirmed the positive relationship of 25(OH)D with adiposity markers and both AA and Caucasian women. The study provides a unique example of the use of SEM in nutrition research within a clinical context. This model should be further tested in other populations.

A role of 1,25(OH)2D3 supplementation in rats with nonalcoholic steatohepatitis induced by choline-deficient diet

BACKGROUND AND AIMS

It has been reported that 1,25(OH)2D3 (1,25-VD3) ameliorates the progression of nonalcoholic steatohepatitis (NASH). However, it is unclear whether 1,25-VD3 plays a role in NASH induced by a choline-deficient (CD) diet. In this study, we investigated the roles of 1,25-VD3 in the development and progression of NASH in rats induced by a CD diet.

METHODS AND RESULTS

Wistar rats with NASH induced by a CD diet were subjected to intraperitoneal injections of 1, 5, or 10 μg/kg of 1,25-VD3 twice weekly for 12 weeks. The administration of 1,25-VD3 decreased free fatty acids (FFAs), triglycerides (TGs), thiobarbituric acid-reactive substances (TBARS), the number of apoptotic cells, and the expression of tissue inhibitor of metalloproteinase-1 (TIMP-1) in the liver, and it improved liver histology, but it did not change the total antioxidant capacity (TAOC) in the liver. Interestingly, the level of CK18-M30 was decreased in the liver of model animals. Treatment with 1,25-VD3 may restrain the downregulation of CK18-M30 in the liver and its release into the bloodstream, thus decreasing the level of serum CK18-M30. 1,25-VD3 supplementation elevated the serum level of 25(OH)D3 and the expression of VDR in the liver. The dose-effect relationship of 1,25-VD3 indicated that 1,25-VD3 slows down the development and progression of NASH induced by a CD diet, but higher doses of 1,25-VD3 may lead to adverse effects.

CONCLUSION

The results suggest the presence of both antagonistic and adverse dose-dependent effects of the long-term supplementation of 1,25-VD3 on NASH induced by a CD diet.

Association of TUSC3 gene polymorphisms with non-syndromic mental retardation based on nuclear families in the Qinba mountain area of China

TUSC3 interacts with the protein phosphatase 1 and magnesium ion transport system, which plays an important role in learning and memory. Abnormal conditions of learning and memory are common clinical characteristics of mental retardation (MR). However, the association of TUSC3 genetic polymorphisms with MR remains unknown. A total of 456 DNA samples including 174 nuclear families containing MR were collected in the Qinba mountain area of China. The genotypes of eight tag single nucleotide polymorphisms of TUSC3 were evaluated with traditional genetic methods. Family-based association tests, transmission disequilibrium tests (TDTs), and haplotype relative risk (HRR) analyses were performed to investigate the association between genetic variants of the TUSC3 gene and MR. The genetic polymorphisms rs10093881, rs6530893, and rs6994908 were associated with MR (all P values <0.05) based upon the results of single-site TDT and HRR analyses. The haplotype block consisting of rs6530893 and rs6994908, harboring the sixth exon of TUSC3, was also associated with MR (all P values <0.05). This study demonstrated an association between genetic polymorphisms of the TUSC3 gene and MR in the Qinba mountain area, the sixth exon of which might contribute to the risk of MR. However, further studies are needed on the causal mechanisms in this association.

[Relationship between serum histamine levels and ST-segment resolution in patients with acute myocardial infarction treated with primary percutaneous coronary intervention]

OBJECTIVE

To investigate the dynamic changes in serum histamine levels and their association with ST-segment resolution in patients with acute ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI).

METHODS

A total of 84 consecutive STEMI patients who received primary PCI were enrolled in this study. The dynamic changes in serum histamine levels were observed from before PCI to 1 week after PCI. Factors associated with ST-segment resolution were identified by multivariate regression analysis.

RESULTS

The serum histamine levels of STEMI patients decreased during the first week after PCI. Multivariate regression analysis showed that the factors associated with ST-segment resolution 2 h after PCI were: the histamine level 2 h after PCI (r=-0.361, P=0.001), pain to balloon time, infarct related artery, and thrombolysis in myocardial infarction (TIMI) flow grade after PCI.

CONCLUSION

The higher histamine level 2 h after PCI was independently associated with poor myocardial reperfusion in STEMI patients.

Effect of codon optimization on expression levels of human cystatin C in Pichia pastoris

Human cystatin C (CysC) is a cysteine proteinase inhibitor with many potential applications. To facilitate further studies of the functions and applications of CysC, we improved the heterologous expression of CysC using a basic codon optimization method. In this study, we cloned the high-GC content wild-type sequence of the CysC gene and also designed a slightly AT-biased sequence, with codons optimized for expression in the Pichia pastoris GS115 strain. Our results showed that the optimized coding sequence of human CysC increased the expression and secretion of the CysC protein by approximately 3- to 5-fold (90-96 mg CysC/L) in yeast, compared with the expression levels of the native CysC gene (17.9-18.4 mg CysC/L). We designed, constructed, and applied an optimized version of the CysC gene for the Pichia expression system. Our results demonstrate that the optimized coding sequence provides a higher yield of secreted CysC than that produced using the wild-type gene. Our data also serve as a practical example demonstrating a rational design strategy for the heterologous expression of secreted proteins.

Association between metabolic syndrome and white matter lesions in middle-aged and elderly patients

BACKGROUND AND PURPOSE

Metabolic syndrome (MetS) has been reported to be associated with silent lacunar infarction, which is highly related to white matter lesions (WMLs). However, little is known about the relationship between MetS and the prevalence of WMLs. The association between MetS, its components and WMLs in middle-aged and elderly patients was investigated.

METHODS

Consecutive patients aged 50 years and older were prospectively enrolled in this study. All participants underwent magnetic resonance imaging scans to assess the presence and severity of WMLs. The MetS was defined according to the updated National Cholesterol Education Program's Adult Treatment Panel III criteria. Multivariate logistic regression analyses were performed to examine the relationship between MetS, its components and WMLs.

RESULTS

A total of 852 patients were enrolled in the study. MetS was present in 38.4%. MetS was associated with an increased risk of periventricular WMLs (PVWMLs) and deep WMLs (DWMLs) after multivariable adjustment (odds ratio 3.21, 95% confidence interval 2.26-4.55 for PVWMLs; odds ratio 2.93, 95% confidence interval 2.09-4.09 for DWMLs). Amongst MetS components, elevated blood pressure, elevated fasting blood glucose and low high density lipoprotein cholesterol were associated with PVWMLs, whilst elevated blood pressure and low high density lipoprotein cholesterol were related to DWMLs.

CONCLUSIONS

Our findings demonstrate that MetS is associated with the prevalence of PVWMLs and DWMLs independent of other risk factors in middle-aged and elderly patients. The association between MetS as a cluster and WMLs was not driven by MetS components.

Identification of microRNAs and target genes involved in serous ovarian carcinoma and their influence on survival

AIMS

To identify the expression of key microRNAs and their predicted target genes involved in serous ovarian carcinoma (SOC) and correlation between miRNAs and prognosis.

MATERIALS AND METHODS

The authors used quantitative polymerase chain reaction (qPCR) to detect the expression of miR-145, miR-143, miR-146a, miR-93, miR-29a, miR-18a, and miR-200a in tissues of 56 primary SOC patients and 30 benign lesion patients. Four protein (MUC1, FAP, MMP2, MMP9) expressions were identified by western blotting and immunohistochemical stain. The Kaplan-Meier method was used to estimate the relationship of these miRNAs with overall survival rate.

RESULTS

In SOC tissue, expression of miR-200a, miR-93, miR-146a, and miR-18a were up-regulated, while miR-145, miR-143, miR-29a were down-regulated. MUC1, FAP, MMP2, and MMP9 were overexpressed in SOC. MiR-143 or miR-145 higher expressed patients had significantly higher overall survival (OS) rates, while miR-93 or miR-200a lower expressed patients also had higher OS rates.

DISCUSSION

These results suggested that several miRNAs and their regulated target transcripts may have important roles in the initiation and development of SOC. MiR-145/miR-143, miR-200a, and miR-93 could be used as prognostic biomarkers.

Characteristics of diagnosis and therapy of adolescent malignant ovarian tumors

BACKGROUND

To improve the early diagnosis rate of adolescent malignant ovarian tumors, avoid misdiagnosis, select proper therapy, avoid excessive therapy, and render therapy more tolerable.

MATERIALS AND METHODS

A comprehensive review of adolescent malignant ovarian tumors, such as types, difficulties of early diagnosis, therapeutic principles, prognosis, fertility preserving through the authors' clinical experience, with reference to Chinese and international literatures.

RESULTS AND CONCLUSION

The majority of adolescent malignant tumors are malignant germ cell, the malignancy is high and it is difficult to diagnose in the early stage, likely to be ignored. Their diagnosis is therefore fundamental, while selecting the most appropriate therapeutic approach that also considers fertility-sparing without compromising prognosis and avoiding over-treatment.

Abstract P2-05-19: Pathway-based analysis of breast cancer

Objective: Although HER2 and ER pathways are predominant pathways altered in breast cancer, it is now well accepted that many other signaling pathways are also involved in the pathogenesis of breast cancer, especially in triple negative breast cancer. The understanding of these additional pathways may assist in identifying new therapeutic approaches for breast cancer.

Methods: 13 invasive ductal carcinoma tissues and 5 benign breast tissues were analyzed for the mRNA expression level of 1243 cancer pathway-related genes using SmartChip (WaferGen, CA), a real-time PCR-base method. In addition, the levels of 154 cancer pathway-related proteins and phosphoproteins were measured using our innovative Protein Pathway Array.

Results: Out of 1,243 mRNAs, 68.7% were detected in breast cancer and 73 mRNAs were statistically significant between benign and cancer tissues. Of these mRNAs, 105 only expressed in breast cancer tissues and 33 mRNAs only expressed in normal breast tissues. Out of 154 proteins and phosphoproteins, 39% were detected in cancer tissues and 50 proteins were significantly differentiated between tumor and normal tissues. Interestingly, only 3 genes (CDK6, Vimentin and SLUG) showed decrease of both protein and mRNA. Six proteins (BCL6, CCNE1, PCNA, PDK1, SRC and XIAP) showed differentially expressed between tumor and normal tissues but no differences were observed at mRNA levels. Analyses of mRNA and protein data using Ingenuity Pathway Analysis showed more 15 pathways were altered in breast cancers and 6 of them shared between mRNAs and proteins, including p53, IL17, HGF, NGF, PTEN and PI3K/AKT.

Conclusion: There is a broad dysregulation of various pathways in breast cancer both at protein levels and mRNA levels. It is important to note that mRNA expression does not correlate with protein level, suggesting that different regulation mechanisms between proteins and mRNAs.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-05-19.

Terahertz wavefronts measured using the Hartmann sensor principle

We demonstrate for the first time that the Hartmann wavefront sensor (HWS) principle can be applied for characterizing the wavefronts of terahertz (THz) electromagnetic radiation. The THz Hartmann wavefront sensor consists of a metallic plate with an array of holes and a two-dimensional scanable pyro-electric detector. The THz radiation with different wavefronts was generated by a far-infrared gas laser operated at 2.5 THz in combination with a number of objects that result in known wavefronts. To measure the wavefront, a beam passing through an array of holes generates intensity spots, for which the positions of the individual spot centroids are measured and compared with reference positions. The reconstructed wavefronts are in good agreement with the model expectations.

Synthesis of solasodine glycoside derivatives and evaluation of their cytotoxic effects on human cancer cells

Solasodine glycosides, such as solamargine, have been proved to be very important anti-cancer agents. In order to discover more potent cytotoxic agents and explore the preliminary structure activity relationship, a new series of solasodine glycosides 2-9 were synthesized via a transglycosylation strategy, and their cytotoxic activity against a panel of human cancer cell lines (MCF-7, KB, K562, and PC3 cells) were evaluated by MTT assays. The results indicated that compounds 2, 8, and 9 with the substitute moiety of rhamnose, 2-hydroxyethoxymethyl, and 1,3-dihydroxypropan-2-yloxy-methyl, respectively, exhibited quite strong anticancer activity. The underlying mechanism tests demonstrated that these compounds could induce apoptosis detected by DAPI staining, and Annexin V and propidium iodide binding. Cell cycle analysis indicated that the cancer cells were predominantly arrested at the G2/M phase when exposure to these compounds was examined by flow cytometry. These compounds may serve as lead candidates in the development of novel chemotherapeutics for cancer treatment.

Molecular cloning and expression analysis of heat-shock protein 70 in orange-spotted grouper Epinephelus coioides following heat shock and Vibrio alginolyticus challenge

In this study, the complementary (c)DNA encoding heat-shock protein 70 (Hsp70) of orange-spotted grouper Epinephelus coioides (OsgHsp70) was cloned. OsgHsp70 was 2206 bp and encoded 652 amino acids with predicted molecular mass of 70·89 kDa and theoretical isoelectric point of 5·48. Three Hsp70 family signatures, bipartite nuclear localization signal sequence (NLS) and cytoplasmic characteristic motif (EEVD) were observed in the OsgHsp70, which shared high similarity in amino-acid sequences with the Hsp70 gene of other vertebrates. The results indicated that the OsgHsp70 is a member of the heat-shock protein 70 family. The Hsp70 messenger (m)RNA expressions were quantified by real-time PCR following heat shock, bacterial infection and immunization with formalin-killed Vibrio alginolyticus, a kind of bacterial pathogen that causes septicaemia. Hsp70 mRNA expression in gill, kidney, spleen, thymus gland, muscle and total-blood samples increased at first and then decreased gradually following heat shock. A similar time-dependent pattern was observed following V. alginolyticus pathogen challenge, in which Hsp70 mRNA expression peaked at 24 h after live bacterial infection and 3 days after dead bacterial vaccination. The results indicated that the Hsp70 gene was inducible and involved in the fish immune response.

Long distance measurement with femtosecond pulses using a dispersive interferometer

We experimentally demonstrate long distance measurements with a femtosecond frequency comb laser using dispersive interferometry. The distance is derived from the unwrapped spectral phase of the dispersed interferometer output and the repetition frequency of the laser. For an interferometer length of 50 m this approach has been compared to an independent phase counting laser interferometer. The obtained mutual agreement is better than 1.5 μm (3×10(-8)), with a statistical averaging of less than 200 nm. Our experiments demonstrate that dispersive interferometry with a frequency comb laser is a powerful method for accurate and non-incremental measurement of long distances.

Time-frequency distribution of interferograms from a frequency comb in dispersive media

We investigate general properties of the interferograms from a frequency comb laser in a non-linear dispersive medium. The focus is on interferograms at large delay distances and in particular on their broadening, the fringe formation and shape. It is observed that at large delay distances the interferograms spread linearly and that its shape is determined by the source spectral profile. It is also shown that each intensity point of the interferogram is formed by the contribution of one dominant stationary frequency. This stationary frequency is seen to vary as a function of the path length difference even within the interferogram. We also show that the contributing stationary frequency remains constant if the evolution of a particular fringe is followed in the successive interferograms found periodically at different path length differences. This can be used to measure very large distances in dispersive media.

Abstract P6-05-05: Signaling Pathways Activated in Her 2 and ER Negative Breast Cancers

Introduction: Breast cancer is the most common cancer in women (192,370 new cases in 2009) and the second leading cause of cancer death (40,000) among women in USA. Current multimodality treatment of breast cancer is based on the level of ER expression and Her 2 gene amplification. However, no effective treatment is currently available for breast cancers with low level expression of ER and no amplification of Her 2 gene. The aim of this study is to identify protein pathways activated in the breast cancer with negative expression of ER and Her 2. Method: Protein Pathway Array was used to assess the level of protein expression and phosphorylation in 71 paired fresh frozen breast samples (tumor and adjacent benign tissue). A total 159 antibodies were evaluated which represent most important signal transduction pathways involved in proliferation, apoptosis, angiogenesis, invasion and metastasis. Several potential therapeutic kinase proteins were also assessed. Results: A total 20 proteins (PCNA, phospho-PTEN, cyclin B1 cyclin E1, CDK6, E-cadherin, NFkB, ect) were differentially expressed between normal and tumor tissues based on the statistical analysis. In Her 2 negative tumors (n=37), 3 proteins were differentially expressed and among them, 2 were up-regulated (CDK6 and HSD1) and 1 was down-regulated (IGF). In ER negative tumors (n=18), 4 proteins (HSD, SK, TDP and Slug) was up-regulated and 1 proteins were down-regulated (E-cadherin). In triple negative tumors (n=13), one protein (E-cadherin) down-regulated and 2 proteins (TDP and HSD) were up-regulated. Furthermore, based on the expression pattern of these proteins, tumors negative for both ER and Her 2 (n=15) can be clustered into 3 groups

Figure 1: Subclassification of breast cancers negative for ER and Her-2 based protein pattern.

Hierarchical clustering analysis of 20 differentially expressed proteins in

15 ER/Her-2 negative breast cancers. The cancers can be separated into 3 subtypes. Red indicates overexpression, green underexpression, black no change, and gray no expression. Each column represents a protein. Each row represents a sample.

Conclusion: Our study showed that distinct sets of signaling pathways activated in ER and Her 2 negative breast cancers. The increased expression of cell cycle progression proteins in Her 2 negative tumors suggests activation of cell proliferation via different growth promotion pathway. Similarly, different cell proliferation pathways are also activated in ER negative tumors. This finding may be used to design future clinical trial based on the activation of different signaling pathways.

Receptor for advanced glycation end products (RAGE) soluble form (sRAGE): a new biomarker for lung cancer

Receptor for advanced glycation end products (RAGE) may be involved in the pathogenesis of cancer progression. Pathological effects mediated via RAGE are physiologically inhibited by soluble RAGE (sRAGE). The aim of this study was to identify sRAGE and RAGE expression profile in lung cancer patients. An ELISA method was used to quantify serum sRAGE in 45 individuals. Additionally, surgical specimens of 28 lung cancer patients were also included for RAGE expression by immunohistochemistry. Serum sRAGE was significantly decreased in lung cancer patients compared with controls (vs. healthy donors, P=0.034; vs. pulmonary tuberculosis patients, P=0.010). Lower sRAGE concentration was negative correlated with lymph node involvement (N0 vs. N1-2, P=0.028). Down regulation of membranous and cytoplasmic expression for RAGE was also lower in lung cancer tissue than in nearby normal lung tissue. Correlation with serum sRAGE concentration and RAGE expression in lung cancer tissue was existed by CV values. The results indicate that serum sRAGE levels are decreased during lung cancer progression and could reflect decreased RAGE expression in tissue. Serum sRAGE may serve as an effective and convenient diagnostic biomarker for lung cancer.

KEYWORDS

sRAGE, serum, RAGE, tissue, lung cancer.

An Ang1-Tie2-PI3K axis in neural progenitor cells initiates survival responses against oxygen and glucose deprivation

Neural progenitor cells (NPCs) have the potential to survive brain ischemia and participate in neurogenesis after stroke. However, it is not clear how survival responses are initiated in NPCs. Using embryonic mouse NPCs and the in vitro oxygen and glucose deprivation (OGD) model, we found that angiopoietin-1 (Ang1) could prevent NPCs from OGD-induced apoptosis, as evidenced by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling and annexin V labeling. Ang1 significantly elevated tunica intima endothelial kinase 2 (Tie2) autophosphorylation level, suggesting the existence of functional Tie2 receptors on NPCs. NPCs under OGD conditions exhibited reduction of Akt phosphorylation, decrease of the Bcl-2/Bax ratio, activation of caspase-3, cleavage of PARP, and downregulation of beta-catenin and nestin. Ang1 reversed the above changes concomitantly with significant rising of survival rates of NPCs under OGD, but all these effects of Ang1 could be blocked by either soluble extracellular domain of Tie2 Fc fusion protein (sTie2Fc) or the phosphoinositide 3-kinase (PI3K) inhibitor 2-(4-morpholinyl)-8-phenyl-1(4H)-benzopyran-4-one (LY294002). Our findings suggest the existence of an Ang1-Tie2-PI3K signaling axis that is essential in initiation of survival responses in NPCs against cerebral ischemia and hypoxia.

High-accuracy long-distance measurements in air with a frequency comb laser

We experimentally demonstrate that a femtosecond frequency comb laser can be applied as a tool for long-distance measurement in air. Our method is based on the measurement of cross correlation between individual pulses in a Michelson interferometer. From the position of the correlation functions, distances of up to 50 m have been measured. We have compared this measurement to a counting laser interferometer, showing an agreement with the measured distance within 2 microm (4x10(-8) at 50 m).