The lactonase activity of paraoxonase 1 (PON1) has a crucial antiatherogenic function, and also serves as an important biochemical marker in human blood because the aberrant lactonase activity of ...PON1 is a key indicator for a number of diverse human diseases. However, no sensitive fluorescence assays that detect PON1 lactonase activity are available. We report the synthesis of two fluorescence turn-on chemical probes
and
(
) able to quantify PON1 lactonase activity. The chemical probes were constructed utilizing a disulfide-containing bicyclononyne, derivatives of rhodamine B and carboxyfluorescein, and reactions including copper-free azide-alkyne cycloaddition. Fluorescence quenching in
was characterized by spectroscopic studies and was mainly attributed to the effect of contact quenching. Kinetic analysis of
confirmed the outstanding reactivity and specificity of
with thiols in the presence of general base catalysts. The
-based assay was employed to determine PON1 lactonase activity, with a linear range of 10.8-232.1 U L
and detection limit (LOD) of 10.8 U L
, to quantify serum PON1 activity in human sera, and to determine the
of 20.9 μM for the 2-hydroxyquinoline inhibition of PON1 lactonase. We are employing
to develop high-throughput assays for PON1 lactonase activity.
Abstract
The direct impact of chronic hepatitis B and hepatitis C on neurocognition remains elusive due to the frequent comorbidities, and the domains of the neurocognitive functions affected have ...rarely been investigated comprehensively. We cross-sectionally assessed the neurocognitive functions of the individuals with chronic hepatitis B, chronic hepatitis C, treated chronic hepatitis C with a sustained virologic response, and their healthy control counterparts. Laboratory examinations were used to investigate the impact of inflammation on neurocognition, exclude the medical conditions that could interfere with neurocognition assessment, and assess liver function and fibrotic severity of the liver of the participants. This study found the detrimental impact of chronic hepatitis B on language and executive functions. In contrast, individuals with chronic hepatitis C showed deficits in executive functions, psychomotor speed, memory, and attention. Successful elimination of hepatitis C resulted in improved liver function, but not neuropsychological test performance. Moreover, erythrocyte sedimentation rate level was found to mediate the deficits in the attention of individuals with chronic hepatitis C. These results demonstrate the neurocognitive deficits and the difference in the profiles of neurocognitive deficits in individuals with chronic hepatitis B and chronic hepatitis C. Our study also provided results suggesting the mediation by systemic inflammation on the attention deficit in individuals with chronic hepatitis C.
A central question in the field of graphene-related research is how graphene behaves when it is patterned at the nanometre scale with different edge geometries. A fundamental shape relevant to this ...question is the graphene nanoribbon (GNR), a narrow strip of graphene that can have different chirality depending on the angle at which it is cut. Such GNRs have been predicted to exhibit a wide range of behaviour, including tunable energy gaps1, 2 and the presence of one-dimensional (1D) edge states3, 4, 5 with unusual magnetic structure6, 7. Most GNRs measured up to now have been characterized by means of their electrical conductivity, leaving the relationship between electronic structure and local atomic geometry unclear8, 9, 10. Here we present a sub-nanometre-resolved scanning tunnelling microscopy (STM) and spectroscopy (STS) study of GNRs that allows us to examine how GNR electronic structure depends on the chirality of atomically well-defined GNR edges. The GNRs used here were chemically synthesized using carbon nanotube (CNT) unzipping methods that allow flexible variation of GNR width, length, chirality, and substrate11, 12. Our STS measurements reveal the presence of 1D GNR edge states, the behaviour of which matches theoretical expectations for GNRs of similar width and chirality, including width-dependent energy splitting of the GNR edge state. PUBLICATION ABSTRACT
Background & Aims
Although hepatitis B virus (HBV) and hepatitis C virus (HCV) infections remain major risk factors for hepatocellular carcinoma (HCC), non‐viral causes of HCC, particularly ...non‐alcoholic fatty liver disease (NAFLD), are becoming increasingly prevalent. The aim of this study was to compare the clinical characteristics and survival of cryptogenic and viral HCC.
Methods
We conducted a retrospective cohort study involving 3878 consecutive HCC patients seen at two tertiary centres in the United States and one in Taiwan from 2004 to 2014. We compared the clinical characteristics, treatment and survival of patients by underlying aetiology: cryptogenic (n = 696), HBV (n = 1304) or HCV (n = 1878).
Results
Cirrhosis was present in 66.8% of the cryptogenic HCC patients, compared with 74.7% of HBV‐related HCC (HBV‐HCC) (P = .001) and 85.9% of HCV‐HCC (P < .001). Compared to viral HCC, cryptogenic HCC patients presented with larger tumours and at later stages of disease. Five‐year overall survival was 16.3% among cryptogenic HCC patients compared with 31.9% among HBV‐HCC patients and 27.7% among HCV‐HCC patients (P < .001 for both by the log‐rank test). HCC aetiology was not an independent predictor of survival, though ethnicity, cirrhosis status, meeting Milan criteria and treatment allocation were.
Conclusions
Compared with viral HCC patients, those with cryptogenic HCC had lower prevalence of cirrhosis, were diagnosed with larger tumours at more advanced stages of disease, and had poorer overall survival. Additional efforts are needed to identify patients at risk of cryptogenic HCC and to identify cryptogenic HCC at earlier stages of disease.
Recommended treatment for hepatitis C virus genotype 1 (HCV‐1) patients is peginterferon plus ribavirin for 48 weeks. We assessed whether treatment duration of 24 weeks is as effective as standard ...treatment in HCV‐1 patients with a rapid virological response (RVR; seronegative for hepatitis C virus HCV RNA at 4 weeks). Two hundred HCV‐1 patients were randomized (1:1) to either 24 or 48 weeks of peginterferon‐alpha‐2a (180 μg/week) and ribavirin (1000–1200 mg/day) with a 24‐week follow‐up. The primary endpoint was a sustained virological response (SVR; seronegative for HCV RNA at 24‐week follow‐up). Overall, the 48‐week arm had a significantly higher SVR rate (79%) than the 24‐week arm (59%, P = 0.002). For 87 (43.5%) patients with an RVR, the 24‐week arm had a lower SVR rate 88.9%; 95% confidence interval (CI): 80%–98% than the 48‐week arm (100%, P = 0.056). For 52 patients with low baseline viremia (<400,000 IU/mL) and an RVR, the 24‐week arm had rates (CI) of relapse and SVR of 3.6% (−3%–11%) and 96.4% (89%–103%), respectively, which were comparable to those of the 48‐week arm (0% and 100%) with difference (CI) of 3.6% (−7.2%–6.6%) and −3.6% (−14.3% to −0.6%), respectively. Multivariate analysis in all patients showed that RVR was the strongest independent factor associated with an SVR, followed by treatment duration, mean weight–based exposure of ribavirin, and baseline viral load. Conclusion: HCV‐1 patients derive a significantly better SVR from 48 weeks versus 24 weeks of peginterferon/ribavirin even if they attain an RVR. Both 24 and 48 weeks of therapy can achieve high SVR rates (>96%) in HCV‐1 patients with low viral loads and an RVR. (HEPATOLOGY 2008;47:1884–1893.)
Adiponectin, an adipocyte-derived protein, has antiatherogenic and antidiabetic effects, but how it confers the atherogenic effects is not well known. To study the antiatherogenic mechanisms of ...adiponectin, we examined whether it interacts with atherogenic low density lipoprotein (LDL) to attenuate LDL's atherogenicity. L5, the most electronegative subfraction of LDL, induces atherogenic responses similarly to copper-oxidized LDL (oxLDL). Unlike the native LDL endocytosed via the LDL receptor, L5 and oxLDL are internalized by cells via the lectin-like oxidized LDL receptor-1 (LOX-1). Using enzyme-linked immunosorbent assays (ELISAs), we showed that adiponectin preferentially bound oxLDL but not native LDL. In Chinese hamster ovary (CHO) cells transfected with the LOX-1 or LDL receptor, adiponectin selectively inhibited the uptake of oxLDL but not of native LDL, respectively. Furthermore, adiponectin suppressed the internalization of oxLDL in human coronary artery endothelial cells (HCAECs) and THP-1-derived macrophages. Western blot analysis of human plasma showed that adiponectin was abundant in L5 but not in L1, the least electronegative subfraction of LDL. Sandwich ELISAs with anti-adiponectin and anti-apolipoprotein B antibodies confirmed the binding of adiponectin to L5 and oxLDL. In LOX-1-expressing CHO cells, adiponectin inhibited cellular responses to oxLDL and L5, including nuclear factor-κB activation and extracellular signal-regulated kinas phosphorylation. In HCAECs, adiponectin inhibited oxLDL-induced endothelin-1 secretion and extracellular signal-regulated kinase phosphorylation. Conversely, oxLDL suppressed the adiponectin-induced activation of adenosine monophosphate-activated protein kinase in COS-7 cells expressing adiponectin receptor AdipoR1. Our findings suggest that adiponectin binds and inactivates atherogenic LDL, providing novel insight into the antiatherogenic mechanisms of adiponectin.
Background and Aim
Hepatitis B virus (HBV) may reactivate when treating chronic hepatitis C (CHC) with direct acting antivirals (DAA). We aim to investigate the risk of HBV reactivation during DAA ...therapy.
Methods
Chronic hepatitis C patients receiving pan‐oral DAA therapy from December 2013 to August 2016 were evaluated. Fifty‐seven patients that had a past HBV infection (negative hepatitis B surface antigen HBsAg and positive hepatitis B core antibody) and seven patients that had a current HBV infection (positive HBsAg) were enrolled. Serum HBV and hepatitis C virus (HCV) markers were regularly measured. The endpoints were the HCV sustained virological response (SVR) and the HBV virological/clinical reactivation.
Results
The overall SVR12 rate was 96.9%, and two patients, one with positive HBsAg, had a relapse of HCV. No episodes of HBV virological reactivation were observed among the patients with a past HBV infection. For the seven patients with a current HBV infection, HBV virological reactivation was found in four (57.1%) of the seven patients. Clinical reactivation of HBV was observed in one patient with pretreatment detectable HBV DNA and recovered after entecavir administration. For the other three patients with HBV virological reactivation, the reappearance of low level HBV DNA without clinical reactivation was observed. HBsAg levels demonstrated only small fluctuations in all the patients.
Conclusions
There was a minimal impact of hepatitis B core antibody seropositivity on HCV efficacy and safety. For CHC patients with current HBV infection, the risk of HBV reactivation was present, and monitoring the HBV DNA level during therapy is warranted.
Background & Aims
Gamma‐glutamyl transferase (GGT) has been predictive of chronic hepatitis C‐related hepatocellular carcinoma (HCC) development. Its role in the risk of HCC in chronic hepatitis B ...(CHB) patients treated with nucleotide/nucleoside analogues (NAs) is elusive.
Methods
A total of 2172 CHB patients from East Asia were randomized into development and validation groups in a 1:2 ratio. Serum GGT levels before and 6 months (M6) after initiating NAs and the potential risk factors were measured. The primary endpoint was HCC development 12 months after NA initiation.
Results
The annual incidence of HCC was 1.4/100 person‐years in a follow‐up period of 11 370.7 person‐years. The strongest factor associated with HCC development was high M6‐GGT levels (>25 U/L; hazard ratio HR/95% confidence interval CI: 3.31/2.02‐5.42, P < .001), followed by cirrhosis (HR/CI: 2.06/1.39‐3.06, P < .001), male sex (HR/CI: 2.01/1.29‐3.13, P = .002) and age (HR/CI: 1.05/1.03‐1.17, P < .001). Among cirrhotic patients, the incidence of HCC did not differ between those with high or low M6‐GGT levels (P = .09). In contrast, among non‐cirrhotic patients, the incidence of HCC was significantly higher for those with M6‐GGT level >25 U/L than for their counterparts (P < .001). Cox regression analysis revealed that the strongest factor associated with HCC development in non‐cirrhotic patients was high M6‐GGT levels (HR/CI: 5.05/2.52‐10.16, P < .001), followed by age (HR/CI: 1.07/1.04‐1.09, P < .001). Non‐cirrhotic elderly patients with high M6‐GGT levels had a similarly high HCC risk as cirrhotic patients did (P = .29).
Conclusions
On‐treatment serum GGT levels strongly predicted HCC development in CHB patients, particularly non‐cirrhotic patients, treated with NAs.
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