Cell death in mammalian development

During embryogenesis there is an exquisite orchestration of cellular division, movement, differentiation, and death. Cell death is one of the most important aspects of organization of the developing embryo, as alteration in timing, level, or pattern of cell death can lead to developmental anomalies. Cell death shapes the embryo and defines the eventual functions of the organs. Cells die using different paths; understanding which path a dying cell takes helps us define the signals that regulate the fate of the cell. Our understanding of cell death in development stems from a number of observations indicating genetic regulation of the death process. With today's increased knowledge of the pathways of cell death and the identification of the genes whose products regulate the pathways we know that, although elimination of some of these gene products has no developmental phenotype, alteration of several others has profound effects. In this review we discuss the types and distributions of cell death seen in developing mammalian embryos as well as the gene products that may regulate the process.

Quantification of combined method for interferences reduction in multichannel surface electroenterogram

Surface electroenterogram (EEnG) is a non-invasive method for monitoring the intestinal motility. However, surface EEnG signals are contaminated by strong physiological interferences. The main interferences which affect high-frequency components of surface EEnG are cardiac activity and movement artifacts. The aim of this work is to quantify the effectiveness of a combined method based on empirical mode decomposition and independent component analysis to remove these interferences from multichannel surface EEnG. In order to do so, several parameters were calculated from five recording sessions: Signal-to-ECG interference ratio (S/I) and variation of energy over 2 Hz (EF2). The results show that the S/I of processed signals was significantly higher than that of original signals, moreover the improvement of the S/I ratio is due to the attenuation of energy associated to interference. The proposed method also allows cancelling movement artifacts from surface EEnG, reducing considerably the non-physiological variation of EF2. Furthermore after the application of the combined method, correlation coefficient between EF2 of internal recording with EF2 of surface recording is greatly higher. Therefore, the proposed method could be helpful to reduce high-frequency interferences in EEnG recording and to provide more robust non-invasive intestinal motility indicators.

High resolution spectroscopy of (lambda)(12)B by electroproduction

An experiment measuring electroproduction of hypernuclei has been performed in hall A at Jefferson Lab on a 12C target. In order to increase counting rates and provide unambiguous kaon identification two superconducting septum magnets and a ring imaging Cherenkov detector were added to the hall A standard equipment. An unprecedented energy resolution of less than 700 keV FWHM has been achieved. Thus, the observed (Lambda)(12)B spectrum shows for the first time identifiable strength in the core-excited region between the ground-state s-wave Lambda peak and the 11 MeV p-wave Lambda peak.

The study of the relationship between Notch signal transduction pathway and polycomb protein Bmi1 in colorectal caner cells

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Background: As is known the polycomb group protein BMI1 has been shown to support normal stem cell proliferation via its putative stem cell factor function. However, the potential molecular mechanism of BMI1 act as a cancer stem cell factor may also promote cancer development is unclear. In this study we demonstrated for the first time that Notch signal transduction pathway regulating expression of Bmi1 in colorecta caner cells and investigate the Notch1 mRNA and Bmi1 mRNA level in human colorectal cancer samples and their correlation with clinicopathological parameters of colorectal cancer. Methods and Results: We assessed Notch1 and Bmi1 mRNA in 50 cases of colorectal cancer and adjacent normal tissue by RT-PCR. The immunohistochemistry was used to determine the expression of ICN and in the 50 tissues of colorectal cancer and normal mucosa. Bmi1 SW480 cells were treated with DAPT (g-secretase inhibitor) at different times. MTT assay and flow cytometry were used to measure the proliferation and apoptosis of SW480 cells. The expression of ICN, Bmi1 were measured by western blot. Notch1 and Bmi1 mRNA level were increased in colorectal cancer compared with adjacent normal mucosa (P<0.05), the median values were 1.97-fold, 1.88-fold, respectively. It was found that overexpression of Notch1 and Bmi1 was related to differentiation and lymph nodes metastasis in colorectal cancer (P<0.05). The correlation between Notch1 and Bmi1 mRNA level, ICN and Bmi1 protein level are significant at the 0.01 level. Treating SW480 with DAPT, resulted in significant growth inhibition, apoptosis induction and downregulation of ICN and Bmi1. Conclusion: Our results show that overexpression of Notch1 and Bmi1 may play a critical role in the development of colorectal cancer. Notch1 signal transduction pathway regulating expression of Bmi1 in colorectal cancer cells.Blockade of Notch1 signal pathway can inhibit proliferation and accelerate apoptosis of colorectal cancer. [Key words] Colorectal cancer; BMI1; Signal transducers and activators of transcription3; Western blotting

No significant financial relationships to disclose.

Empirical mode decomposition: a method to reduce low frequency interferences from surface electroenterogram

The surface electroenterogram (EEnG) is a non-invasive method of studying myoelectrical bowel activity. However, surface EEnG recordings are contaminated by cardiac activity, respiratory and motion artifacts, and other sources of interference. The aim of this work is to remove the respiration artifact and the very low frequency components from surface EEnG by means of empirical mode decomposition (EMD). Eleven recording sessions were carried out on canine model. Several parameters were calculated before and after the application of the method: signal-to-interference ratio (S/I ratio) and the attenuation level of the signal and of interference. The results show that the S/I ratio was significantly higher after the application of the method (3.68+/-5.54 dB vs. 10.45+/-3.65 dB), the attenuation level of signal and of interference is -0.49+/-0.80 dB versus -7.26+/-5.42 dB, respectively. Therefore, EMD could be a useful aid in identifying the intestinal slow wave and in removing interferences from EEnG recordings.

Amplification and specific expression of T-bet gene in nasal NK/T-cell lymphoma

To define the specific genetic alterations in nasal natural killer/T-cell lymphoma (N-NK/T-L), the assay of restriction landmark genomic scanning (RLGS), a genome-wide method, was used to investigate a pair of genomic DNA from N-NK/T-L cells and peripheral blood leukocytes of the same patient. The intensified spots in displayed N-NK/T-L gel of RLGS were subjected to bioinformatic analysis by virtual genome scan (VGS) and one of candidate spots proved to be T-bet gene (T-box expressed in T-cell). The pair of samples was consequently analysed by Southern hybridization, revealing genomic amplification of T-bet but not different status of DNA methylation. The amplification of T-bet was also discovered in other cases of N-NK/T-L by dot blotting. The expression of T-bet was investigated by in situ hybridization (ISH) and immunohistochemistry (IHC). The results showed that T-bet predominantly expressed in N-NK/T-L (ISH: 90.0%, 18/20; IHC: 80%, 16/20), while few cases of B-cell lymphoma (ISH: 11.8%, 2/17; IHC: 17.6%, 3/17) or T-cell lymphoma (ISH: 33.3%, 2/6; IHC: 16.7%, 1/6) were positive. The difference of T-bet expression in either ISH or IHC between N-NK/T-L and B-cell lymphoma or T-cell lymphoma was statistically significant (P < 0.05). Moreover, the expression of T-bet was not detected in normal spleen tissue and chronic inflammatory nasal mucosa. The results suggested that the amplification of T-bet gene or resulting its over-expression of T-bet gene might be involved in the development of N-NK/T-L and thus it should be worth confirming whether the over-expression of T-bet be helpful to the diagnosis of N-NK/T-L in further study.

Stilbenoids from Stemona sessilifolia

Two new dihydrostilbenes, stilbostemins H (1), I (2), and a new dihydrophenanthrene, stemanthrene E (3), were isolated and identified from the roots of Stemona sessilifolia, together with known stilbostemins B, D and G, and stemanthrenes A and C (4-8). Structures of new stilbenoids were established by 1D and 2D (1)H NMR and (13)C NMR spectroscopic analyses.

Anti-malarial agent artesunate inhibits TNF-alpha-induced production of proinflammatory cytokines via inhibition of NF-kappaB and PI3 kinase/Akt signal pathway in human rheumatoid arthritis fibroblast-like synoviocytes

OBJECTIVES

Recent studies indicate that the anti-malarial agent artemisinin and its derivatives may exert an anti-inflammatory effect. In this study, we explored the effect of artesunate, an artemisinin derivative, on tumour necrosis factor (TNF)-alpha-induced production of interleukins, IL-1beta, IL-6 and IL-8, in human rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS), and further investigated the signal mechanism by which this compound modulates those cytokines' production.

METHODS

RA FLS obtained from patients with active RA were stimulated with TNF-alpha and incubated with artesunate, and IL-1beta, IL-6 and IL-8 production was measured by ELISA. DNA-binding activity and nuclear translocation of nuclear factor kappa B (NF-kappaB) were measured by a sensitive multi-well colourimetric assay and confocal fluorescence microscopy, respectively. Signal transduction proteins expression was measured by western blot.

RESULTS

Artesunate decreased the secretion of IL-1beta, IL-6 and IL-8 from TNF-alpha-stimulated RA FLS in a dose-dependent manner. Artesunate also prevented TNF-alpha-induced nuclear NF-kappaB translocation, DNA-binding activity and gene transcriptional activity, as well as phosphorylation and degradation of IkappaBalpha, but phosphorylation of p38 mitogen-activated protein kinase, extracellular signal-regulated kinase and c-Jun N-terminal kinase were unaffected. The production of IL-1beta, IL-6 and IL-8 induced by TNF-alpha was decreased by pyrrolidine dithiocarbamate (PDTC), a chemical inhibitor of NF-kappaB. These observations suggest that artesunate inhibits production of IL-1beta, IL-6 and IL-8 through inhibition of NF-kappaB signalling pathway. We also showed that artesunate prevented Akt phosphorylation. TNF-alpha-induced production of IL-1beta, IL-6 and IL-8 was hampered by treatment with the phosphatidylinositol 3 (PI3) kinase inhibitor LY294002, suggesting that inhibition of Akt activation might inhibit IL-1beta, IL-6 and IL-8 production induced by TNF-alpha.

CONCLUSIONS

Our results indicate that artesunate exerts an anti-inflammatory effect in RA FLS and provide the evidence that artesunate may have therapeutic potential for RA.

Precision measurements of the nucleon strange form factors at Q2 approximately 0.1 GeV2

We report new measurements of the parity-violating asymmetry A(PV) in elastic scattering of 3 GeV electrons off hydrogen and 4He targets with <theta(lab)> approximately 6.0 degrees . The 4He result is A(PV)=(+6.40+/-0.23(stat)+/-0.12(syst))x10(-6). The hydrogen result is A(PV)=(-1.58+/-0.12(stat)+/-0.04(syst))x10(-6). These results significantly improve constraints on the electric and magnetic strange form factors G(E)(s) and G(M)(s). We extract G(E)(s)=0.002+/-0.014+/-0.007 at <Q(2)>=0.077 GeV2, and G(E)(s)+0.09G(M)(s)=0.007+/-0.011+/-0.006 at <Q(2)>=0.109 GeV2, providing new limits on the role of strange quarks in the nucleon charge and magnetization distributions.

Labdane diterpenes from the seeds of Platycladus orientalis

Two new labdane diterpenes, 14(R),15-dihydroxy-8(17),12(E)-labdadien-19-oic acid (1) and 16-methyl-12,15-epoxy-8(17),13-labdadien-19-oic acid (2), together with four known compounds, were isolated from the seeds of Platycladus orientalis. Their structures were established by spectroscopic methods. The stereochemistry of compound 1 was defined by X-ray crystallographic analysis.

Enterobacter Bacteremia: Clinical Features, Risk Factors for Multiresistance and Mortality in a Chinese University Hospital

BACKGROUND

This study was performed to characterize the clinical features and to identify the risk factors for multiresistance and mortality in patients with Enterobacter bacteremia.

PATIENTS AND METHODS

A number of 126 patients with Enterobacter bacteremia in 1995-2004 at the Medical university-affiliated Hospital of Anhui, China were retrospectively analyzed.

RESULTS

Of the 126 cases of bacteremia, 81 (64.3%) patients were identified as nosocomial infection. The overall multiresistance rate was 45.2% (57/126). Multiresistance was associated with nosocomial infection, recent invasive procedure, previous third-generation cephalosporins therapy, prolonged perioperative prophylaxis, the species of Enterobacter (E. cloacae) and polymicrobial bacteremia in univariate analysis. In multivariate analysis, previous third-generation cephalosporins therapy (OR = 13.6, p = 0.007) and prolonged perioperative prophylaxis (OR = 6.4, p = 0.029) were the strong, independent risk factors for the multiresistance. The crude 30-day mortality rate was 39.7% (50/126). Mortality directly attributed to Enterobacter spp. was 32.5% (41/126), which was significantly associated with multiresistance, nosocomial infection, recent invasive procedure, and inadequately empirical therapy in univariate analysis. Multivariate analysis revealed that only nosocomial infection (OR = 3.292, p = 0.049) was independently associated with mortality. The survival curve showed that the inappropriate initial therapy group had a lower probability of survival than the appropriate therapy group in infection-related mortality (Log Rank, p = 0.0142).

CONCLUSION

Enterobacter is becoming increasingly important nosocomial pathogens. Nosocomial infection is a clinical risk factor tightly associated with multiresistance and worse outcome. More judicious use of third-generation cephalosporins may decrease the incidence of nosocomial multiresistant Enterobacter spp. in China.

Diagnosis of pericardial effusion: correlation between echocardiography and computed tomography

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Calculation and usage of containment monitor radiation readings during PWR accidents

A computer code named CALCON for calculation of containment monitor radiation readings is introduced. The validity of the code was verified by comparison with data given in IAEA technical documents. The contribution of isotopes to containment readings under conditions of core melt, gap release and normal coolant release were investigated. The conclusions were that the radiation reading in containment is mainly from iodine and noble gases when sprays are off, and the radiation reading is mainly from noble gases when sprays are on, and during the beginning hours when radionuclides are released into containment, the monitor readings will decrease rapidly. Curves of containment radiation readings versus shutdown time for DAYA BAY nuclear power plant were calculated using CALCON.

Double-hadron leptoproduction in the nuclear medium

The first measurements of double-hadron production in deep-inelastic scattering within the nuclear medium were made with the HERMES spectrometer at DESY HERA using a 27.6 GeV positron beam. By comparing data for deuterium, nitrogen, krypton, and xenon nuclei, the influence of the nuclear medium on the ratio of double-hadron to single-hadron yields was investigated. Nuclear effects on the additional hadron are clearly observed, but with little or no difference among nitrogen, krypton, or xenon, and with smaller magnitude than effects seen on previously measured single-hadron multiplicities. The data are compared with models based on partonic energy loss or prehadronic scattering and with a model based on a purely absorptive treatment of the final-state interactions. Thus, the double-hadron ratio provides an additional tool for studying modifications of hadronization in nuclear matter.

Clinical assessment compared with breathalyser readings in the emergency room: concordance of ICD-10 Y90 and Y91 codes

OBJECTIVES

The purpose of this study was to analyse the validity of clinical assessment of alcohol intoxication (ICD-10 Y91) compared with estimated blood alcohol concentration (BAC) using a breath analyser (ICD-10 Y90) among patients in the emergency room (ER).

METHODS

Representative samples of ER patients reporting within six hours of injury (n = 4798) from 12 countries comprising the WHO Collaborative Study on Alcohol and Injuries were breath analysed and assessed blindly for alcohol intoxication at the time of ER admission. Data were analysed using Kendall's Tau-B to measure concordance of clinical assessment and BAC, and meta analysis to determine heterogeneity of effect size.

RESULTS

Raw agreement between the two measures was 86% (Tau-B 0.68), but was lower among those reporting drinking in the six hours prior to injury (raw agreement 39%; Tau-B 0.32). No difference was found by gender or for timing of clinical assessment in relation to breath analysis. Patients positive for tolerance or dependence were more likely to be assessed as intoxicated at low levels of BAC. Estimates were homogeneous across countries only for females and for those negative for alcohol dependence.

CONCLUSIONS

Clinical assessment is moderately concordant with level of BAC, but in those patients who have actually been drinking within the last six hours the concordance was much less, possibly because, in part, of a tendency on the part of clinicians to assign some level of intoxication to anyone who appeared to have been drinking.