Thermal degradation mechanisms of wood under inert and oxidative environments using DAEM methods

The pyrolytic behavior of wood is investigated under inert and oxidative conditions. The TGA experiment is given a temperature variation from 323 to 1173 K by setting the heating rate between 5 and 40 K/min. The results of DTG curves show that the hemicellulose shoulder peak for birch is more visible under inert atmosphere due to the higher content of reactive xylan-based hemicellulose (mannan-based for pine). When oxygen presents, thermal reactivity of biomass (especially the cellulose) is greatly enhanced due to the acceleration of mass loss in the first stage, and complex reactions occur simultaneously in the second stage when char and lignin oxidize. A new kinetic model is employed for biomass pyrolysis, namely the distributed activation energy model (DAEM). Under inert atmosphere, the distributed activation energy for the two species is found to be increased from 180 to 220 kJ/mol at the solid conversion of 10-85% with the high correlation coefficient. Under oxidative atmosphere, the distributed activation energy is about 175-235 kJ/mol at the solid conversion of 10-65% and 300-770 kJ/mol at the solid conversion of 70-95% with the low correlation coefficient (below 0.90). Comparatively, the activation energy obtained from established global kinetic model is correspondingly lower than that from DAEM under both inert and oxidative environments, giving relatively higher correlation coefficient (more than 0.96). The results imply that the DAEM is not suitable for oxidative pyrolysis of biomass (especially for the second mass loss stage in air), but it could represent the intrinsic mechanism of thermal decomposition of wood under nitrogen better than global kinetic model when it is applicable.

Optical pacing of the embryonic heart

Light has been used to noninvasively alter the excitability of both neural and cardiac tissue 1-10. Recently, pulsed laser light has been shown to be capable of eliciting action potentials in peripheral nerves and in cultured cardiomyocytes 7-10. Here, we demonstrate for the first time optical pacing (OP) of an intact heart in vivo. Pulsed 1.875 μm infrared laser light was employed to lock the heart rate to the pulse frequency of the laser. A laser Doppler velocimetry (LDV) signal was used to verify the pacing. At low radiant exposures, embryonic quail hearts were reliably paced in vivo without detectable damage to the tissue, indicating that OP has great potential as a tool to study embryonic cardiac dynamics and development. In particular, OP can be utilized to control the heart rate, and thereby alter stresses and mechanically transduced signaling.

The pyrolytic degradation of wood-derived lignin from pulping process

Lignin is a key component in the biomass with a complex polymeric structure of the phenyl-C(3) alkyl units. The kraft lignin from the wood pulping process is tested in TG-FTIR and Py-GC-MS. The samples are pyrolyzed in TGA coupled with FTIR from 30 to 900 degrees C at the heating rate of 20 and 40K/min. The evolution of phenolic compounds in the initial pyrolysis stage of lignin is determined by FTIR, while the second stage is mainly attributed to the production of the low molecular weight species. A bench-scale fast pyrolysis unit is employed to investigate the effect of temperature on the product yield and composition. It is found that the guaiacol-type and syringol-type compounds as the primary products of lignin pyrolysis are predominant in bio-oil, acting as the significant precursors for the formation of the derivatives such as the phenol-, cresol- and catechol-types. A series of free-radical chain-reactions, concerning the cracking of different side-chain structures and the methoxy groups on aromatic ring, are proposed to demonstrate the formation pathways for the typical compounds in bio-oil by closely relating lignin structure to the pyrolytic mechanisms. The methoxy group (-OCH(3)) is suggested to work as an important source for the formation of the small volatile species (CO, CO(2) and CH(4)) through the relevant free radical coupling reactions.

Selectivity of lynx proteins on insect nicotinic acetylcholine receptors in the brown planthopper, Nilaparvata lugens

Neuronal nicotinic acetylcholine receptors (nAChRs) are major excitatory neurotransmitter receptors in both vertebrates and invertebrates. Two lynx proteins (Nl-lynx1 and Nl-lynx2) have been identified in the brown planthopper, Nilaparvata lugens, which act as modulators on insect nAChRs. In the present study, two lynx proteins were found to act on the triplet receptor Nlalpha1/Nlalpha2/beta2 expressed in Xenopus oocytes, increasing agonist-evoked macroscopic currents, but not changing agonist sensitivity and desensitization properties. Nl-lynx1 and Nl-lynx2 increased I(max) (maximum responses) of acetylcholine to 4.85-fold and 2.40-fold of that of Nlalpha1/Nlalpha2/beta2 alone, and they also increased I(max) of imidacloprid to 2.57-fold and 1.25-fold. Although, on another triplet nAChRs Nlalpha3/Nlalpha8/beta2, Nl-lynx2 increased I(max) of acetylcholine and imidacloprid to 3.63-fold and 2.16-fold, Nl-lynx1 had no effects on I(max) of either acetylcholine or imidacloprid. The results demonstrate the selectivity of lynx proteins for different insect nAChR subtypes. This selectivity was also identified in native N. Lugens. Co-immunoprecipitation was found between Nlalpha1/Nlalpha2-containing receptors and both Nl-lynx1 and Nl-lynx2, but was only found between Nlalpha3/Nlalpha8-containing receptors and Nl-lynx2. When the previously identified Nlalpha1(Y151S) and Nlalpha3(Y151S) mutations were included (Nlalpha1(Y151S)/Nlalpha2/beta2 and Nlalpha3(Y151S)/Nlalpha8/beta2), the increase in I(max) of imidacloprid, but not acetylcholine, caused by co-expression of Nl-lynx1 and Nl-lynx2 was more noticeable than that of their wildtype counterparts. Taken together, these data suggest that two modulators, Nl-lynx1 and Nl-lynx2, might serve as an influencing factor in target site insensitivity in N. lugens, such as Y151S mutation.

Mutant small heat shock protein B3 causes motor neuropathy: utility of a candidate gene approach

OBJECTIVE

Idiopathic peripheral neuropathy is common and likely due to genetic factors that are not detectable using standard linkage analysis. We initiated a candidate gene approach to study the genetic influence of the small heat shock protein (sHSP) gene family on an axonal motor and motor/sensory neuropathy patient population.

METHODS

The promoter region and all exonic and intronic sequences of the 10 sHSP genes (HSPB1-HSPB10) were screened in a cohort of presumed nonacquired, axonal motor and motor/sensory neuropathy patients seen at the Ohio State University Neuromuscular Clinic.

RESULTS

A missense mutation in the gene encoding small heat shock protein B3 (HSPB3, also called HSP27, protein 3) was discovered in 2 siblings with an asymmetric axonal motor neuropathy. Electrophysiologic studies revealed an axonal, predominantly motor, length-dependent neuropathy. The mutation, HSPB3(R7S), is located in the N-terminal domain and involves the loss of a conserved arginine.

CONCLUSIONS

The discovery of an HSPB3 mutation associated with an axonal motor neuropathy using a candidate gene approach supports the notion that the small heat shock protein gene family coordinately plays an important role in motor neuron viability.

A Systems Analysis of Mitotic Apparatus Inhibitors Defines a Response Network for Breast Cancer

Deregulation of aspects of the mitotic apparatus leads to increased genome instability, carcinogenesis and aggressive tumor behavior in human and rodent model systems1. This knowledge has stimulated development of inhibitors of elements of the mitotic apparatus as anticancer agents including PLK1, CENPE, and AURKB and several are now being tested for efficacy clincially2-6. These trials and eventual clinical use will benefit from molecular markers that predict response. In order to identify such markers, we assessed quantitative responses to the agents GSK461364, GSK923295 and GSK1070916 that target PLK1, CENPE and AURKB; respectively, in a panel of 50 breast cancer cell lines. This analysis showed that basal subtype cell lines were preferentially sensitive to all three agents and that responses among the lines to the three agents were strongly correlated. This may be explained by our discovery that components of the mitotic apparatus including PLK1, CENPE and AURKB form a transcriptionally co-regulated network comprised of more than 50 genes that is preferentially active in basal subtype of breast cell lines and primary tumors. Remarkably, this network also is activate in subsets of cancers of the lung, ovarian, prostate and brain, Wilms tumor, human blood malignancies and selected normal tissues. We then defined a mitotic apparatus network index (MANI) and showed that high MANI was associated with poor outcome clinically and with preferential responsive to GSK461364, GSK923295 and GSK1070916 in preclinical models. This suggests that measures of the MANI will identify poor outcome tumors that will likely respond well to mitotic apparatus network gene inhibitors as well as potential dose limiting normal tissues.Reference1. Quigley, D.A. et al. Nature 458, 505-8 (2009).2. Strebhardt, K. & Ullrich, A. Nat. Rev. Cancer 6, 321-330 (2006).3. Toyoshima-Morimoto, F., Taniguchi, E., Shinya, N., Iwamatsu, A. & Nishida, E. Nature 410, 215-20 (2001).4. Barr, F.A., Sillje, H.H. & Nigg, E.A. Nat. Rev. Mol. Cell. Biol. 5, 429–440 (2004).5. McInnes, C. et al. Nat. Chem. Biol. 2, 608–617 (2006).6. Yamada, S. et al. Oncogene 23, 5901-5911(2004).

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2020.

The mechanism for thermal decomposition of cellulose and its main products

Experiment is performed to investigate the mechanism of the cellulose pyrolysis and the formation of the main products. The evolution of the gaseous products is examined by the 3-D FTIR spectrogram at the heating rate of 5-60 K/min. A pyrolysis unit, composed of fluidized bed reactor, carbon filter, vapour condensing system and gas storage, is employed to investigate the products of the cellulose pyrolysis under different temperatures (430-730 degrees C) and residence time (0.44-1.32 s). The composition in the bio-oil is characterized by GC-MS while the gases sample is analyzed by GC. The effects of temperature and residence time on the main products in bio-oil (LG, 5-HMF, FF, HAA, HA and PA) are examined thoroughly. Furthermore the possible routes for the formation of the products are developed from the direct conversion of cellulose molecules and the secondary reactions of the fragments. It is found that the formation of CO is enhanced with elevated temperature and residence time, while slight change is observed for the yield of CO(2).

Clinical evaluation of a colorimetric oligonucleotide chip for genotyping hepatitis C virus

INTRODUCTION

Hepatitis C virus (HCV) is a major cause of chronic liver disease worldwide. It is associated with the development of end-stage liver disease and hepatocellular carcinoma. Studies have shown that determination of hepatitis C virus (HCV) genotypes is clinically important for prediction of the clinical course and the outcome of antiviral therapy. The aim of this study was to evaluate a colorimetric oligonucleotide chip, which can be used for the rapid and economical detection of the genotypes/subtypes of hepatitis C virus.

DESIGN AND METHODS

A total of 860 serum specimens were tested by an oligonucleotide chip genotyping test. Partial genotype results were compared with those obtained by sequencing method and INNOLiPA HCV II assay. The relative sensitivities of the methods were assessed by using the 5'NCR amplicon from the HCV RNA fluorescent amplicor HCV tests and Light Cycler.

RESULTS

Of 860 serum specimens tested for their genotypes/subtypes by the oligonucleotide array, 607 HCV positive serum samples could be typed by the sequencing method and 60 of 607 HCV positive serum specimens were typed by INNOLiPA HCV II method. Identification of genotype/subtypes by nucleotide sequencing and INNOLiPA HCV II assay showed respective coincidence rates of 99.8% and 96.7% with the HCV oligonucleotide chip results. And the colorimetric method exhibited 99.8% of relative sensitivity compared with the fluorescent amplicor HCV tests.

CONCLUSION

To our knowledge this oligonucleotide chip genotyping method offers a fast and convenient way to determine the genotype in large-scale settings. The tests can be easily adapted by a clinical diagnostic laboratory.

Participation of leukotriene C(4) in the regulation of suicidal erythrocyte death

Eryptosis, the suicidal death of erythrocytes, is characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine exposure at the erythrocyte surface. Eryptosis is triggered by increase in cytosolic Ca(2+) concentration upon energy depletion. The present study explored the involvement of leukotrienes. Western blotting was employed to detect the cysteinyl-leukotriene receptor cysLT1, competitive immune assay to determine leukotriene release from erythrocytes, Fluo3 fluorescence to estimate cytosolic Ca(2+) concentration, forward scatter to analyse cell volume and annexin V-binding to disclose phosphatidylserine exposure. As a result, erythrocytes expressed the leukotriene receptor CysLT1. Glucose depletion (24 hours) significantly increased the formation of the cysteinyl-leukotrienes C(4)/D(4)/E(4). Leukotriene C(4) (10 nM) increased Ca(2+) entry, decreased forward scatter, activated caspases 3 and 8, and stimulated annexin V-binding. Glucose depletion similarly increased annexin V-binding, an effect significantly blunted in the presence of the leukotriene receptor antagonist cinalukast (1 microM) or the 5-lipoxygenase inhibitor BW B70C (1 microM). In conclusion, upon energy depletion erythrocytes form leukotrienes, which in turn activate cation channels, leading to Ca(2+) entry, cell shrinkage and cell membrane scrambling. Cysteinyl-leukotrienes thus participate in the signaling of eryptosis during energy depletion.

Norrie-Warburg syndrome: two novel mutations in patients with classical clinical phenotype

Norrie-Warburg syndrome (NWS) is a rare X-linked disorder characterized by blindness, which is invariable, deafness and mental disturbances, which are present occasionally. We describe here two novel mutations, a missense mutation (C126S) and a 1-base pair insertion (insT466/T467), together with a recurrent mutation (M1V), found in patients presenting with the classical clinical phenotype of NWS. All three mutations are likely to result in prominent structural changes of the norrin protein.

Vitamin D and glucocorticoids differentially modulate chemokine expression in human airway smooth muscle cells

BACKGROUND AND PURPOSE

Chemokines play a critical role in the pathogenesis of asthma and facilitate the recruitment of inflammatory cells in the airways. Evidence now suggests that airway smooth muscle (ASM) may serve as a source of chemokines in inflamed airways. Although vitamin D has potent anti-inflammatory properties in vitro in some cell types, its effects on ASM cells remain unclear. Here, we investigated whether 1alpha, 25-dihydroxy vitamin D3 (calcitriol) modulated chemokine production in ASM.

EXPERIMENTAL APPROACH

Human ASM cell cultures were derived from tracheal samples taken during surgery. ASM cells were treated with tumour necrosis factor alpha (TNFalpha) and/or interferon gamma (IFNgamma) for 24 h in the presence of calcitriol and/or the glucocorticoid fluticasone added 2 h before. RANTES (regulated upon activation, normal T-cell expressed and secreted), interferon-inducible protein 10 (IP-10) and fractalkine (FKN) levels in cell supernatants were measured by ELISA.

KEY RESULTS

In TNFalpha-treated cells, calcitriol inhibited RANTES and IP-10 secretion in a concentration-dependent manner. FKN levels were negligible. In TNFalpha/IFNgamma-treated cells, whereas fluticasone or calcitriol alone partially inhibited RANTES secretion (by 38 and 20%, respectively), the combination of both drugs additively inhibited RANTES secretion (by 60%). No effect was observed on IP-10 secretion. Whereas fluticasone enhanced FKN secretion (by 50%), calcitriol significantly decreased FKN levels (by 50%). Interestingly, calcitriol blocked the stimulatory effect of fluticasone on FKN secretion, which was inhibited by 60% with the combination of calcitriol and fluticasone.

CONCLUSIONS AND IMPLICATIONS

These findings suggest that vitamin D uniquely modulates human ASM expression of chemokines and may exert some beneficial effects in the treatment of steroid-resistant patients with asthma.

A dual role for the API2 moiety in API2-MALT1-dependent NF-kappaB activation: heterotypic oligomerization and TRAF2 recruitment

Mucosa-associated lymphoid tissue (MALT) lymphoma is the most common extranodal lymphoid neoplasm. Chromosomal translocation t(11;18)(q21,q21) is found in 30% of gastric MALT lymphomas and is associated with a failure to respond to standard treatment and a tendency to disseminate. This translocation generates a chimeric protein composed of N-terminal sequences of Inhibitor of Apoptosis 2 (API2, also known as BIRC3 and cIAP2) fused to C-terminal sequences of MALT1. API2-MALT1 promotes cell survival and proliferation via activation of nuclear factor-kappaB (NF-kappaB). Here, we investigate the mechanism by which the API2 moiety contributes to NF-kappaB stimulation. We find that the API2 moiety mediates oligomerization of API2-MALT1 as well as interaction with tumor necrosis factor receptor-associated factor 2 (TRAF2). Surprisingly, oligomerization does not occur via homotypic interaction; rather, the API2 moiety of one monomer interacts with the MALT1 moiety of another monomer. Further, the specific region of the API2 moiety responsible for mediating oligomerization is distinct from that mediating TRAF2 binding. Although deletion or mutation of the TRAF2 binding site does not inhibit oligomerization, it does lead to dramatically decreased NF-kappaB activation. Deletion of both TRAF2 binding and oligomerization regions results in near-complete loss of NF-kappaB activation. Thus, API2 moiety-mediated heterotypic oligomerization and TRAF2 binding both contribute to maximal API2-MALT1-dependent NF-kappaB stimulation.

Associations between Chlamydophila infections, schizophrenia and risk of HLA-A10

Several microbes have been suspected as pathogenetic factors in schizophrenia. We have previously observed increased frequencies of chlamydial infections and of human lymphocyte antigen (HLA)-A10 in independent studies of schizophrenia. Our aim here was to analyze frequencies of three types of Chlamydiaceae in schizophrenic patients (n=72), random controls (n=225) and hospital-patient controls (n=36), together with HLA-A genotypes. Patients were diagnosed with schizophrenia according to Diagnostic and Statistical Manual of Mental Disorders-IV. Blood samples were collected at the beginning of hospitalization and analyzed with Chlamydiaceae species-specific polymerase chain reaction (PCR). Control panels consisted of randomly selected volunteers and hospitalized, non-schizophrenic patients. We found chlamydial infection in 40.3% of the schizophrenic patients compared to 6.7% in the controls. The association of schizophrenia with Chlamydiaceae infections was highly significant (P=1.39 x 10(-10), odds ratio (OR)=9.43), especially with Chlamydophila psittaci (P=2.81 x 10(-7), OR=24.39). Schizophrenic carriers of the HLA-A10 genotype were clearly most often infected with Chlamydophila, especially C. psittaci (P=8.03 x 10(-5), OR=50.00). Chlamydophila infections represent the highest risk factor yet found to be associated with schizophrenia. This risk is even further enhanced in carriers of the HLA-A10 genotype.

[Identification of a novel human MAST4 gene, a new member of the microtubule associated serine-threonine kinase family]

Human protein kinases make up a large superfamily of homologous proteins, which are related by virtue of their kinase domains (also known as catalytic domains). Here we report the cloning and characterization of a novel human MAST4 (microtubule associated serine/threonine kinase family member 4) gene, which locates on human chromosome 5q13. The MAST4 cDNA is 7587 base pairs in length and encodes a putative protein of 2435 amino acids which contains a serine/threonine kinase domain and a PDZ domain. MAST4 protein has 64%, 63%, 59% and 39% identical aminoacid residues with MAST1, MAST2, MAST3 and MASTL respectively. RT-PCR analysis revealed relatively high expression level of MAST4 in most normal human tissues, with an exception of in testis, small intestine, colon and peripheral blood leukocyte.