Comparative evaluation of a point-of-care immunochromatographic test SNAP 4Dx with molecular detection tests for vector-borne canine pathogens in Hong Kong

There are no comprehensive studies on the performance of commonly used point-of-care diagnostic enzyme immunoassay for common arthropod-borne canine pathogens. A comparative evaluation of an immunochromatographic test for these infections with a comprehensive polymerase chain reaction (PCR) test panel was performed on 100 pet dogs and 100 stray dogs without obvious clinical symptoms. Of the 162 positive test results from both immunochromatographic test and PCR, there was 85.2% concordance. The 24 discordant results between serology and PCR occurred in tests involving Ehrlichia canis (14) and Anaplasma platys (10), which may be related to the time of infection. No positive cases of borreliosis or rickettsiosis were detected. One important limitation of the immunochromatographic test was its lack of testing for babesiosis and hepatozoonosis. The former is the most prevalent arthropod-borne canine infection in our cohort (41%). Coinfections were found in 19% stray dogs and 6% of pet dogs with both tests (p<0.01). Seventeen and 8 samples from stray and pet dogs, respectively, were initially positive in the PCR test for Ehrlichia. However, on sequencing of the PCR amplicon, 10 from stray and 2 from pet dogs were found to be Wolbachia sequences instead, with 100% nucleotide identity to the 16S rRNA sequence of Wolbachia endosymbiont of Dirofilaria immitis. The presence of Wolbachia DNAemia (6%) correlated well with the molecular test and immunochromatographic antigen test for D. immitis. © Copyright 2011, Mary Ann Liebert, Inc.published_or_final_versio

Prostaglandin E-2 inhibits transforming growth factor beta 1-mediated induction of collagen alpha(1)(I) in hepatic stellate cells

Background/Aims: Cyclooxygenase-2 (COX-2) has been implicated in a number of hepatic stellate cell (HSC) functions but its relationship to transforming growth factor-beta1 (TGF-beta1)-mediated fibrogenesis is unknown. We assessed the impact of COX-2 inhibition and PGE(2) on the regulation of TGF-beta1-stimulated matrix synthesis in an immortalized human HSC line, LX-1 and corroborated these findings in primary stellate cells. Methods: Expression of COX-2 was assessed by Western blotting and real time quantitative PCR. The effect of NS398, a selective COX-2 inhibitor, and PGE(2) On TGF-beta1-mediated fibrogenesis was examined by measuring mRNA levels of collagen alpha1(I). PGE(2) receptor expression was analyzed by RT-PCR. Results: Under basal conditions, NS398 suppressed PGE(2) synthesis and induced collagen alpha1(l) whereas exogenous PGE(2) suppressed expression of collagen alpha1(I). TGF-beta1 induced COX-2 mRNA, COX-2 protein and PGE(2) biosynthesis. Importantly, TGF-beta1-mediated induction of collagen alpha1(l) was markedly suppressed by the addition of exogenous PGE(2). All four major PGE(2) receptors were expressed in LX-1 cells. Conclusions: These results suggest that COX-2-derived PGE(2) inhibits both basal and TGF-beta1-mediated induction of collagen synthesis by HSC. Based on these findings, it will be important to determine whether inhibiting COX-derived PGE(2) synthesis alters the progression of liver fibrosis in vivo. (C) 2004 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved

Lipoprotein lipase activator ameliorates the severity of dietary steatohepatitis

Dietary model of steatohepatitis was established by feeding mice a methionine choline deficient (MCD) diet. Mice on MCD or control diet for 3 weeks were treated with or without NO-1886, a newly synthetic lipoprotein lipase (LPL) activator. In a separate experiment, NO-1886 was given after pre-treatment with 3 weeks of MCD diet. NO-1886 significantly reduced MCD-induced inflammation by repressing levels of hepatic lipid peroxides and pro-inflammatory tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and cyclooxygenase-2 (COX-2). In addition, NO-1886 dampened hepatic steatosis via accelerating fatty acid oxidation caused by enhanced expression of PPARα, cytochrome P450-10 (Cyp4a10), and Acyl-CoA oxidase (ACO). It failed to regulate genes of fatty acid uptake and synthesis pathways. In conclusion, NO-1886 ameliorated and induced regression of experimental steatohepatitis via increasing endogenous LPL activation resulting in suppression on pro-inflammatory factors and reduction of hepatic fatty acids. These findings indicate that NO-1886 is a potential therapeutic agent for steatohepatitis. © 2007 Elsevier Inc. All rights reserved.link_to_subscribed_fulltex

Quantitative detection of promoter hypermethylation in multiple genes in the serum of patients with colorectal cancer

OBJECTIVES: While promoter hypermethylation is a common molecular alteration of human colorectal cancer that could be detected in the bloodstream, we tested the feasibility of quantitative detection of aberrant DNA methylation in multiple genes in the serum samples of colorectal cancer patients. METHODS: The pre-therapeutic serum samples of 49 colorectal cancer patients and 41 age-matched controls with normal colonoscopy were examined. The presence of methylated DNA in APC (adenomatous polyposis coli), hMLH1 (human MutL homolog 1), and HLTF (helicase-like transcription factor) was detected by quantitative methylation-specific PCR (MethyLight). RESULTS: There was a significant difference in the concentration of methylated serum DNA between cancer patients and controls for HLTF (p= 0.015) and hMLH1 (p= 0.0001) genes, but not for APC gene (p= 0.21). In total, 28 patients with colorectal cancer and 4 controls had methylated DNA detected in at least one marker, which gave a sensitivity of 57% and specificity of 90%. All patients with methylation in two methylation markers had advanced (stage III/IV) cancer (p= 0.006) and patients with methylation in at least one marker tended to have a lower probability of survival (p= 0.08). CONCLUSION: The quantitative detection of aberrant DNA methylation in serum may be a promising high-throughput approach for the noninvasive screening and monitoring of colorectal cancer. © 2005 by Am. Coll. of Gastroenterology Published by Blackwell Publishing.link_to_subscribed_fulltex

Detection of hypermethylated DNA or cyclooxygenase-2 messenger rna in fecal samples of patients with colorectal cancer or polyps

BACKGROUND: Detection of fecal DNA is a promising approach to colorectal cancer screening. However, the sensitivity of current fecal DNA tests for colorectal polyps is low. We evaluated the feasibility of detecting aberrantly methylated DNA or cyclooxygenase-2 (COX-2) mRNA in feces of patients with colorectal cancer or polyps. METHODS: Fecal samples were collected prior to colonoscopy from 20 patients with colorectal cancer, 30 patients with colorectal polyps, and 30 subjects with normal colonic examination. Presence of hypermethylated DNA in 7 tumor-related genes (APC, ATM, hMLH1, sFRP2, HLTF, MGMT, and GSTP1) in stool was analyzed by methylation-specific PCR. COX-2 mRNA in fecal samples was detected by RT-PCR. RESULTS: With the use of this panel of methylation markers, the sensitivity of detecting colorectal cancer and adenoma was 75% (95% CI 50.9-91.3%) and 68% (95% CI 46.5-85.1%), respectively. Three normal subjects also had methylated DNA detected in stool, which gives a specificity of 90% (95% CI 73.5-97.9%). The mean number of genes methylated in DNA from the stool of patients with colorectal cancer and adenoma was 1.4 and 0.9, respectively. In contrast, COX-2 mRNA was detected in the stool samples of 10 (50%) cancer patients and one (4%) patient with advanced adenoma only. Two (6.7%) stool samples from normal subjects also had COX-2 mRNA detected. CONCLUSION: Detection of aberrantly methylated DNA in fecal samples is more sensitive than COX-2 mRNA for detection of colorectal cancer and adenoma. © 2007 by Am. Coll. of Gastroenterology.link_to_subscribed_fulltex

Anti-proliferative and pro-apoptotic effects of herbal medicine on hepatic stellate cell

Hepatic stellate cells (HSC) play a central role in hepatic fibrosis and compounds that promote apoptosis in HSC may have anti-fibrotic potentials. Herbal medicine has long been used in chronic liver disease but there is little scientific evidence for their actions. The present study investigated the effects of 14 commonly used herbs on cellular proliferation and apoptosis of a rat hepatic stellate cell line, HSC-T6 and the underlying mechanism of herb-induced apoptosis. HSC-T6 cell were incubated with herbal extracts and their proliferation was assessed by colorimetric assay. Apoptosis was measured and confirmed by flow cytometry, terminal transferase uridyl nick end labeling (TUNEL) assay and morphological features in hematoxylin and eosin staining. Apoptotic pathways involving Fas receptor and Bcl-2 family were investigated by Western blot. Five herbs, namely Angelica sinensis (AS), Carthamus tinctorius (CT), Ligusticum chuanxiong (LC), Salvia miltiorrhiza (SM) and Stephania tetrandra (ST) demonstrated both anti-proliferative and pro-apoptotic activities in HSC-T6. The highest potency was detected in SM and ST with 51.63 and 44.52% of HSC-T6 showing apoptotic changes, respectively. This was associated with upregulation of Fas and Bax and down-regulation of Bcl-xL in HSC. Fas ligand and Bcl2 expressions remained unchanged. The potential anti-fibrotic effect of herbal medicine warrants further evaluation. © 2005 Elsevier Ireland Ltd. All rights reserved.link_to_subscribed_fulltex

Exhaled air dispersion distances during noninvasive ventilation via different respironics face masks

Background: As part of our influenza pandemic preparedness, we studied the exhaled air dispersion distances and directions through two different face masks (Respironics; Murrysville, PA) attached to a human-patient simulator (HPS) during noninvasive positive-pressure ventilation (NPPV) in an isolation room with pressure of -5 Pa. Methods: The HPS was positioned at 45° on the bed and programmed to mimic mild lung injury (oxygen consumption, 300 mL/min; lung compliance, 35 mL/cm H 2O). Airflow was marked with intrapulmonary smoke for visualization. Inspiratory positive airway pressure (IPAP) started at 10 cm H 2O and gradually increased to 18 cm H 2O, whereas expiratory pressure was maintained at 4 cm H 2O. A leakage jet plume was revealed by a laser light sheet, and images were captured by high definition video. Normalized exhaled air concentration in the plume was estimated from the light scattered by the smoke particles. Findings: As IPAP increased from 10 to 18 cm H 2O, the exhaled air of a low normalized concentration through the ComfortFull 2 mask (Respironics) increased from 0.65 to 0.85 m at a direction perpendicular to the head of the HPS along the median sagittal plane. When the IPAP of 10 cm H 2O was applied via the Image 3 mask (Respironics) connected to the whisper swivel, the exhaled air dispersed to 0.95 m toward the end of the bed along the median sagittal plane, whereas higher IPAP resulted in wider spread of a higher concentration of smoke. Conclusions: Substantial exposure to exhaled air occurs within a 1-m region, from patients receiving NPPV via the ComfortFull 2 mask and the Image 3 mask, with more diffuse leakage from the latter, especially at higher IPAP. © 2009 American College of Chest Physicians.link_to_subscribed_fulltex

Diagnosis of Gastric Cancer by Serum Proteomic Fingerprinting

Background & Aims Accurate serum biomarkers for gastric cancer currently are lacking. We attempted to identify potential diagnostic serum markers for gastric cancer with the use of the surface-enhanced laser desorption/ionization ProteinChip technology. Methods The study was divided into 3 phases: (1) discovery of potential diagnostic markers using sera of gastric cancer patients and controls, (2) development of a diagnostic model, and (3) independent validation of the diagnostic model using a different cohort of gastric cancer and control patients. The serum proteins/peptides were analyzed with 2 types of ProteinChip arrays, IMAC30 arrays loaded with copper (II) ion and CM10 (weak cation exchange) arrays. Results In the discovery set, peak intensities of 31 surface-enhanced laser desorption/ionization proteomic features were significantly higher in gastric cancer patients. The tumor-specific nature of 6 proteomic features with the mass/charge (m/z) values of 5098, 8592, 8610, 11,468, 11,804, and 50,140 was verified by their lower peak intensities in postoperative sera. After excluding the sodium adduct peak (8610 m/z) of the 8592 m/z protein, the peak intensities of the tumor-specific proteomic features were used to develop a linear regression model for calculating a diagnostic index. The area under the receiver operating characteristic curve of the corresponding diagnostic index was 0.92 (95% confidence interval, 0.85-0.99) in the independent validation set. At a specificity of 95%, the sensitivity for gastric cancer detection was 83%. Conclusions A unique serum proteomic fingerprint can be detected in the sera of gastric cancer patients, which may be useful in the noninvasive diagnosis of gastric cancer. © 2006 American Gastroenterological Association Institute.link_to_subscribed_fulltex

Effect of Helicobacter pylori eradication on treatment of gastro-oesophageal reflux disease: A double blind, placebo controlled, randomised trial

Background: The role of Helicobacter pylori eradication in the management of gastro-oesophageal reflux disease (GORD) is controversial. We hypothesised that H pylori eradication leads to worsened control of reflux disease. Methods: Consecutive patients with weekly reflux symptoms were prospectively recruited for endoscopy and symptom evaluation. Patients were enrolled if they had H pylori infection and required long term acid suppressants. Eligible patients were randomly assigned to omeprazole triple therapy (HpE group) or omeprazole with placebo antibiotics (Hp+ group) for one week. Omeprazole 20 mg daily was given for eight weeks for healing of oesophagitis and symptom relief. This was followed by a maintenance dose of 10 mg daily for up to 12 months. The primary study end point was the probability of treatment failure within 12 months, which was defined as either incomplete resolution of symptoms or oesophagitis at the initial treatment phase, or relapse of symptoms and oesophagitis during the maintenance phase. Predictors of treatment failure were determined by Cox's proportional hazards model. Results: A total of 236 GORD patients were screened and 113 (47.9%) were positive for H pylori; 104 (92%) patients were included in the intention to treat analysis (53 in the HpE group and 51 in the Hp+ group). Thirty one patients (30%) had erosive oesophagitis at baseline. H pylori was eradicated in 98% of the HpE group and in 3.9% of the Hp+ group. Overall, 15 patients (28.3%) in the HpE group and eight patients (15.7%) in the Hp+ group had treatment failure. The 12 month probability of treatment failure was 43.2% (95% confidence interval (CI) 29.9-56.5%) in the HpE group and 21.1% (95% CI 9.9-32.3%) in the Hp+ group (log rank test, p = 0.043). In the Cox proportional hazards model, after adjustment for the covariates age, sex, erosive oesophagitis, hiatus hernia, degree of gastritis, and severity of symptoms at baseline, H pylori eradication was the only predictor of treatment failure (adjusted hazard ratio 2.47 (95% CI 1.05-5.85)). Conclusion: H pylori eradication leads to more resilient GORD.link_to_subscribed_fulltex