hong ly - Academia.edu (original) (raw)

Papers by hong ly

European Journal of Inorganic Chemistry, 2013

ABSTRACT The hydrolysis of a series of unactivated dipeptides in the presence of a zirconium(IV)-... more ABSTRACT The hydrolysis of a series of unactivated dipeptides in the presence of a zirconium(IV)-substituted Lindqvist type polyoxometalate, (Me4N)2[W5O18Zr(H2O)3] (designated as ZrW5), was studied by kinetic experiments and NMR spectroscopy. Among the dipeptides examined, those with the X–Ser amino acid sequence were most effectively hydrolyzed. The kinetics of the hydrolysis of histidylserine (His–Ser) was studied in detail; a rate constant of 95.3 (± 0.1) × 10–7 s–1 (pD 7.4 and 60 °C) in the presence of an equimolar amount of ZrW5 was calculated. The binding of His–Ser to ZrW5 was examined by UV/Vis, 1H, 13C, and 183W NMR spectroscopy, and the data indicate that at physiological pD His–Ser chelates the ZrIV through its imidazole nitrogen, amine nitrogen, and amide carbonyl oxygen. In the presence of ZrW5, the pD profile of kobs is bell-shaped, with a maximum reaction rate at pD 7.5. At high pD values an inactive complex is formed as a result of the deprotonation of the amide nitrogen, resulting in inhibition of His–Ser hydrolysis. The effects of pH, temperature, inhibitors, and ionic strength on the hydrolysis rate constant were also investigated, and a full account of the mechanism of this novel reaction is given.

Journal of Pharmacological and Toxicological Methods, 2007

Despite shortcomings, cultures of blood and sterile sites remain the "gold standard" for diagnosi... more Despite shortcomings, cultures of blood and sterile sites remain the "gold standard" for diagnosing systemic candidiasis. Alternative diagnostic markers, including antibody detection, have been developed, but none are widely accepted. In this study, we used an enzyme-linked immunosorbent assay to measure serum antibody responses against 15 recombinant Candida albicans antigens among 60 patients with systemic candidiasis due to various Candida spp. and 24 uninfected controls. Mean immunoglobulin G (IgG) responses against all 15 antigens were significantly higher among patients with systemic candidiasis than among controls, whereas IgM responses were higher against only seven antigens. Using discriminant analysis that included IgG responses against the 15 antigens, we derived a mathematical prediction model that identified patients with systemic candidiasis with an error rate of 3.7%, a sensitivity of 96.6%, and a specificity of 95.6%. Furthermore, a prediction model using a subset of four antigens (SET1, ENO1, PGK1-2, and MUC1-2) identified through backward elimination and canonical correlation analyses performed as accurately as the full panel. Using the simplified model, we predicted systemic candidiasis in a separate test sample of 32 patients and controls with 100% sensitivity and 87.5% specificity. We also demonstrated that IgG titers against each of the four antigens included in the prediction model were significantly higher in convalescent-phase sera than in paired acutephase sera. Taken together, our findings suggest that IgG responses against a panel of candidal antigens might represent an accurate and early marker of systemic candidiasis, a hypothesis that should be tested in future trials.

American Journal of Medicine, 1996

To assess the changing epidemiology of candidemia in the 1990s, to evaluate the clinical implicat... more To assess the changing epidemiology of candidemia in the 1990s, to evaluate the clinical implications for the presence of non-Candida albicans in blood, and to evaluate the presence of antifungal resistance in relation to prior antifungal administration.Multicenter prospective observational study of patients with positive blood cultures for Candida species or Torulopsis glabrata.Four tertiary care medical centers.Four hundred twenty-seven consecutive patients were enrolled. The frequency of candidemia due to non-C. albicans species significantly increased in each hospital throughout the 3.5-year study period (P = 0.01). Thirteen percent of candidemias occurred in patients who were already receiving systemic antifungal agents. Candidemias developing while receiving antifungal therapy were more likely caused by non-C. albicans species than by C. albicans species (P = 0.0005). C. parapsilosis and C. krusei were more commonly seen with prior fluconazole therapy, whereas T. glabrata was more commonly seen with prior amphotericin B therapy. Candida species isolated during episodes of breakthrough candidemia exhibited a significantly higher MIC to the antifungal agent being administered (P < 0.001).In this large scale study, the non-C. albicans species, especially T. glabrata, emerged as important and frequent pathogens causing fungemia. This finding has major clinical implications given the higher complication and mortality rate associated with the non-C. albicans species. The change in the pattern of candidemia might be partly attributed to the increase in number of immunocompromised hosts and the widespread use of prophylactic or empiric antifungal therapy. This is an ominous sign given the in vitro resistance of the non-C. albicans species to currently available antifungal agents.

Journal of Virology, 2008

The NF-B signaling pathway has previously been shown to be required for efficient influenza A vir... more The NF-B signaling pathway has previously been shown to be required for efficient influenza A virus replication, although the molecular mechanism is not well understood. In this study, we identified a specific step of the influenza virus life cycle that is influenced by NF-B signaling by using two known NF-B inhibitors and a variety of influenza virus-specific assays. The results of time course experiments suggest that the NF-B inhibitors Bay11-7082 and ammonium pyrrolidinedithiocarbamate inhibited an early postentry step of viral infection, but they did not appear to affect the nucleocytoplasmic trafficking of the viral ribonucleoprotein complex. Instead, we found that the levels of influenza virus genomic RNA (vRNA), but not the corresponding cRNA or mRNA, were specifically reduced by the inhibitors in virus-infected cells, indicating that NF-B signaling is intimately involved in the vRNA synthesis. Furthermore, we showed that the NF-B inhibitors specifically diminished influenza virus RNA transcription from the cRNA promoter but not from the vRNA promoter in a reporter assay, a result which is consistent with data obtained from virus-infected cells. The overexpression of the p65 NF-B molecule could not only eliminate the inhibition but also activate influenza virus RNA transcription from the cRNA promoter. Finally, using p65-specific small interfering RNA, we have shown that p65 knockdown reduced the levels of influenza virus replication and vRNA synthesis. In summary, we have provided evidence showing, for the first time, that the NF-B host signaling pathway can differentially regulate influenza virus RNA synthesis, which may also offer some new perspectives into understanding the host regulation of RNA synthesis by other RNA viruses.

PLOS One, 2012

Purpose: To evaluate clinicopathologic and molecular features of patients with metastatic colorec... more Purpose: To evaluate clinicopathologic and molecular features of patients with metastatic colorectal cancer (mCRC) and their outcomes in early-phase trials using pathway-targeting agents.

New England Journal of Medicine, 2002

In some parts of the world, peritoneal dialysis is widely used for renal replacement in acute ren... more In some parts of the world, peritoneal dialysis is widely used for renal replacement in acute renal failure. In resource-rich countries, it has been supplanted in recent years by hemodialysis and, most recently, by hemofiltration and associated techniques. The relative efficacy of peritoneal dialysis and hemofiltration is not known. We conducted an open, randomized comparison of pumped venovenous hemofiltration and peritoneal dialysis in patients with infection-associated acute renal failure in an infectious-disease referral hospital in Vietnam. Seventy adult patients with severe falciparum malaria (48 patients) or sepsis (22 patients) were enrolled; 34 were assigned to hemofiltration and 36 to peritoneal dialysis. The mortality rate was 47 percent (17 patients) in the group assigned to peritoneal dialysis, as compared with 15 percent (5 patients) in the group assigned to hemofiltration (P=0.005). The rates of resolution of acidosis and of decline in the serum creatinine concentration in the group assigned to hemofiltration were more than twice those in the group assigned to peritoneal dialysis (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.005), and renal-replacement therapy was required for a significantly shorter period. In a multivariate analysis, the odds ratio for death was 5.1 (95 percent confidence interval, 1.6 to 16) and that for a need for future dialysis was 4.7 (95 percent confidence interval, 1.3 to 17) in the group assigned to peritoneal dialysis. The cost of hemofiltration per survivor was less than half that of peritoneal dialysis, and the cost per life saved was less than one third. Hemofiltration is superior to peritoneal dialysis in the treatment of infection-associated acute renal failure.

Synapse, 2010

We previously reported the absence of high-affinity binding of the group II metabotropic glutamat... more We previously reported the absence of high-affinity binding of the group II metabotropic glutamate receptor agonists LY 354,740 and LY 379,268 to the D2L dopamine receptor. A rebuttal to our findings has since been reported (see Introduction section); this study represents our response. Analysis by LCMS of LY 354,740 and LY 379,268 used in this study revealed the correct molecular mass for these compounds. Both LY 354,740 and LY 379,268 exhibited potent agonist activity for mGluR2 in the 35S-GTPγS assay. Functionally, neither compound displayed antagonist activity in the GTPγS assay with recombinant D2. At concentrations up to 10 μM, both compounds failed to displace [3H]-raclopride, [3H]-PHNO, or [3H]-domperidone in filter-binding assays under isotonic (120 mM NaCl or N-methyl glucamine) or low-ionic strength (no NaCl or N-methyl glucamine) conditions. Some displacement of [3H]-domperidone (20–40%) was observed at 30 μM of LY 354,740 under low-ionic strength and under isotonic conditions in the absence of NaCl. No displacement of [3H]-domperidone was detected in a two site model at lower (<100 nM) concentrations of either compound. Moreover, no D2 activity was observed for LY 354,740 or LY 379,268 in the CellKey™ (cellular dielectric spectroscopy) assay. In this communication, we discuss the possible reasons for differences in our study and the previously published work and implications of these studies for mechanisms of antipsychotic action. Synapse 65:64–68, 2011. © 2010 Wiley-Liss, Inc.

Oral Oncology, 2011

We would like to evaluate the effectiveness of Tomotherapy for decreasing radiation dose to the c... more We would like to evaluate the effectiveness of Tomotherapy for decreasing radiation dose to the cochlea in head and neck cancer patients. A retrospective review of 72 patients undergoing radiation for head and neck cancer was performed. Cochlea dose was compared between 20 patients treated with conventional intensity modulated radiotherapy (IMRT) and 52 treated with Tomotherapy. A review of literature was performed to assess cochlea dose reported with the IMRT technique for head and neck cancer. Mean total cochlea dose was 36 Gy for IMRT compared to 12.1 Gy for Tomotherapy (p = 0.002). Mean right cochlea dose was respectively, 16.6 and 6.2 Gy for IMRT and Tomotherapy (p = 0.007), and 19.3 and 5.9 Gy for the left. Cochlea (p = 0.002). Mean cochlea dose reported in the literature ranged from 16 to 55 Gy with IMRT for head and neck cancer. Helical Tomotherapy for head and neck cancer may significantly decrease radiation dose to the cochlea without sacrificing target volume coverage.

Journal of Molecular Structure-theochem, 2005

A major challenge in understanding the origins of life is to elucidate how nature selects a small... more A major challenge in understanding the origins of life is to elucidate how nature selects a small part of molecules from a large number of candidates as building blocks of life, e.g. amino acids and proteins. Inspired by the thermodynamic principle in protein-structure selection, we attempted to explore whether there exists a thermodynamic criterion to differentiate amino acids from their isomers. In this letter, the energies of 20 natural amino acid and corresponding isomers are calculated by quantum chemical methods. It is revealed that the energy levels of amino acids (especially small ones) are not distributed randomly but located at the bottom of the energy diagrams of their isomers, suggesting that thermodynamic factor plays an important role in selecting the basic building blocks of life. q

PLOS One, 2011

Background: Optimising the fluid resuscitation of patients with severe malaria is a simple and po... more Background: Optimising the fluid resuscitation of patients with severe malaria is a simple and potentially cost-effective intervention. Current WHO guidelines recommend central venous pressure (CVP) guided, crystalloid based, resuscitation in adults.

PLOS One, 2008

Background: Cytokines play important roles in antiviral action. We examined whether polymorphisms... more Background: Cytokines play important roles in antiviral action. We examined whether polymorphisms of interleukin (IL)-12 receptor B1 (IL-12RB1) affect the susceptibility to and outcome of severe acute respiratory syndrome (SARS).

Fuel and Energy Abstracts, 2011

A measurement of the Z/γ⁎Z/γ⁎ transverse momentum (pTZ) distribution in proton–proton collisions ... more A measurement of the Z/γ⁎Z/γ⁎ transverse momentum (pTZ) distribution in proton–proton collisions at s=7 TeV is presented using Z/γ⁎→e+e−Z/γ⁎→e+e− and Z/γ⁎→μ+μ−Z/γ⁎→μ+μ− decays collected with the ATLAS detector in data sets with integrated luminosities of 35 pb−1 and 40 pb−1, respectively. The normalized differential cross sections are measured separately for electron and muon decay channels as well as for their combination up to pTZ of 350 GeV for invariant dilepton masses 66 GeV<mℓℓ<116 GeV66 GeV<mℓℓ<116 GeV. The measurement is compared to predictions of perturbative QCD and various event generators. The prediction of resummed QCD combined with fixed order perturbative QCD is found to be in good agreement with the data.