Rice bacterial blight pathogen Xanthomonas oryzae pv. oryzae produces multiple DSF-family signals in regulation of virulence factor production

<p>Abstract</p> <p>Background</p> <p><it>Xanthomonas </it><it>oryzae </it>pv. <it>oryzae </it>(<it>Xoo</it>) is the causal agent of rice bacterial blight disease. <it>Xoo </it>produces a range of virulence factors, including EPS, extracellular enzyme, iron-chelating siderophores, and type III-secretion dependent effectors, which are collectively essential for virulence. Genetic and genomics evidence suggest that <it>Xoo </it>might use the diffusible signal factor (DSF) type quorum sensing (QS) system to regulate the virulence factor production. However, little is known about the chemical structure of the DSF-like signal(s) produced by <it>Xoo </it>and the factors influencing the signal production.</p> <p>Results</p> <p><it>Xoo </it>genome harbours an <it>rpf </it>cluster comprising <it>rpfB</it>, <it>rpfF</it>, <it>rpfC </it>and <it>rpfG</it>. The proteins encoded by these genes are highly homologous to their counterparts in <it>X. campestris </it>pv. <it>campestris </it>(<it>Xcc</it>), suggesting that <it>Xcc </it>and <it>Xoo </it>might use similar mechanisms for DSF biosynthesis and autoregulation. Consistent with <it>in silico </it>analysis, the <it>rpfF </it>mutant was DSF-deficient and the <it>rpfC </it>mutant produced about 25 times higher DSF-like activity than the wild type <it>Xoo </it>strain KACC10331. From the supernatants of <it>rpfC </it>mutant, we purified three compounds showing strong DSF-like activity. Mass spectrometry and NMR analysis revealed that two of them were the previously characterized DSF and BDSF; the third one was a novel unsaturated fatty acid with 2 double bonds and was designated as CDSF in this study. Further analysis showed that all the three DSF-family signals were synthesized via the enzyme RpfF encoded by <it>Xoo2868</it>. DSF and BDSF at a final concentration of 3 μM to the <it>rpfF </it>mutant could fully restore its extracellular xylanase activity and EPS production to the wild type level, but CDSF was less active than DSF and BDSF in induction of EPS and xylanase. DSF and CDSF shared a similar cell density-dependent production time course with the maximum production being detected at 42 h after inoculation, whereas the maximum production of BDSF was observed at 36 h after inoculation. When grown in a rich medium such as YEB, LB, PSA, and NYG, <it>Xoo </it>produced all the three signals with the majority being DSF. Whereas in nutritionally poor XOLN medium <it>Xoo </it>only produced BDSF and DSF but the majority was BDSF.</p> <p>Conclusions</p> <p>This study demonstrates that <it>Xoo </it>and <it>Xcc </it>share the conserved mechanisms for DSF biosynthesis and autoregulation. <it>Xoo </it>produces DSF, BDSF and CDSF signals in rich media and CDSF is a novel signal in DSF-family with two double bonds. All the three DSF-family signals promote EPS production and xylanase activity in <it>Xoo</it>, but CDSF is less active than its analogues DSF and BDSF. The composition and ratio of the three DSF-family signals produced by <it>Xoo </it>are influenced by the composition of culture media.</p

Evaluation of the TEST 1 erythrocyte sedimentation rate system and intra- and inter-laboratory quality control using new latex control materials

Background: The erythrocyte sedimentation rate (ESR) test has been considered to be a simple procedure, not requiring quality control (QC). However, QC is essential for accuracy and precision. We evaluated the TEST 1 ESR system and performed QC procedures using newly developed latex control materials in three hospitals. Methods: Using tripotassium ethylenediaminetetraacetic acid blood samples (n=184), we compared TEST 1 ESR values with Westergren ESR data and evaluated intra-assay precision. Three levels of latex control materials were used to assess inter-assay precision. Reference range assessment was done using samples from 220 healthy individuals. Inter-laboratory QC with latex control materials in three hospitals was performed. Results: Correlation between TEST 1 ESR and Westergren ESR results was good (p<0.001). Intra-assay precision [coefficients of variation (CV) 6.6%-21.7%] with patient samples and inter-assay precision (CV 0.0%-6.8%) with latex control materials were satisfactory. The reference ranges of 2-10 mm/h for males and 2-19 mm/h for females were established. Inter-laboratory QC data with latex control materials in three hospitals demonstrated good accuracy and satisfactory precision (CV 0.0%-14.4%). Conclusions: Our results demonstrate that the TEST 1 QC is reliable and the latex control materials are valuable for inter-laboratory proficiency testing. Clin Chem Lab Med 2010; 48: 1043-8.Cha CH, 2009, AM J CLIN PATHOL, V131, P189, DOI 10.1309/AJCPOU1ASTLRANIJ*CLIN LAB STAND I, 2008, C28A3 CLSIPiva E, 2007, CLIN BIOCHEM, V40, P491, DOI 10.1016/j.clinbiochem.2006.12.002Padro-Miquel A, 2007, CLIN CHEM LAB MED, V45, P930, DOI 10.1515/CCLM.2007.150Romero A, 2003, CLIN CHEM LAB MED, V41, P232Plebani M, 2002, AM J CLIN PATHOL, V117, P621LEE BH, 2002, J CLIN PATHOL QUALIT, V24, P167GIAVARINA D, 2002, CLIN LAB, V48, P459Piva E, 2001, CLIN CHEM LAB MED, V39, P451*CLIN LAB STAND I, 2000, H2A4 CLSIPlebani M, 1998, AM J CLIN PATHOL, V110, P334BULL BS, 1993, J CLIN PATHOL, V46, P198BULL BS, 1991, PRACTICAL LAB HEMATOFABRY TL, 1987, BLOOD, V70, P1572WESTERGREN A, 1926, AM REV TUBERC, V14, P94

A New Steroidal Saponin from the Tubers of Ophiopogon japonicus and Its Protective Effect Against Cisplatin-Induced Renal Cell Toxicity

A new furostanol saponin, ophiopogonin T, was isolated from the tubers of Ophiopogon japonicus. Its structure was established by extensive spectroscopic techniques including 1D ( 1 H and 13 C) and 2D nuclear magnetic resonance (NMR) experiments (correlation spectroscopy (COSY), heteronuclear single quantum coherence (HSQC), heteronuclear multiple bond correlation (HMBC) and nuclear Overhauser effect spectroscopy (NOESY)), high-resolution electrospray ionization mass spectrometry (ESIMS), and chemical methods. Using cell-based assays, this compound was evaluated for its cytotoxic effect on cancer cell lines and its protective effect against anticancer drug-induced nephrotoxicity. Cisplatin-induced cytotoxicity in porcine kidney (LLC-PK1) cells was significantly reduced upon treatment with ophiopogonin T, without affecting human hepatoma (HepG2) cancer cell proliferation or tube formation in human umbilical vein endothelial cells (HUVECs). These results collectively reflect the beneficial effect of ophiopogonin T on the side effects of cisplatin

Vaccination with a Human Papillomavirus (HPV)-16/18 AS04-Adjuvanted Cervical Cancer Vaccine in Korean Girls Aged 10-14 Years

The human papillomavirus (HPV)-16/18 AS04-adjuvanted cervical cancer vaccine has been demonstrated to be highly efficacious and immunogenic with a favorable safety profile. This study assessed the immunogenicity and safety of the HPV-16/18 AS04-adjuvanted vaccine in healthy Korean girls aged 10-14 yr. This multi-center, observer-blind trial randomly assigned 321 healthy girls to receive three doses (0, 1, 6-month schedule) of HPV-16/18 AS04-adjuvanted vaccine or hepatitis A vaccine. Immunogenicity against vaccine antigens was assessed one month post-Dose 3. Solicited and unsolicited adverse events (AEs) and serious AEs (SAEs) were recorded. In the according-to-protocol analysis, all initially seronegative subjects vaccinated with the HPV-16/18 AS04-adjuvanted vaccine had seroconverted at Month 7, with a peak geometric mean titer (GMT) that was 600-fold higher than the natural infection titer of 29.8 EU/mL for HPV-16 and a peak GMT that was 400-fold higher than the natural infection titer of 22.6 EU/mL for HPV-18. The vaccine was well tolerated with no increase in reactogenicity with subsequent doses and no reports of vaccine-related SAEs. In conclusion, the HPV-16/18 AS04-adjuvanted vaccine is shown to be highly immunogenic and generally well-tolerated in Korean girls aged 10-14 yr

The Use of Complementary and Alternative Medicine in a General Population in South Korea: Results from a National Survey in 2006

The purpose of this survey was to obtain information on the prevalence, costs, and patterns of use of complementary and alternative medicine (CAM) in a general population in the Republic of Korea. In 2006, we conducted nationwide and population-weighted personal interviews with 6,021 adults ranging from 30 to 69 yr of age; the final sample consisted of 3,000 people with a 49.8% response rate. In addition to their general socio-demographics, the respondents were asked about their use of CAM during the previous 12-month period, costs, sources of information, and reasons for use. The prevalence of use overall was 74.8%, while biologically based CAM therapies were the most likely type of use (65.4%). The median annual out-of-pocket expenditures for CAM therapies was about US$203. The primary reason for using CAM was for disease prevention and health promotion (78.8%). The main source of advice about CAM therapies use was most likely to be from family and friends (66.9%). Our study suggests that CAM use has been and continues to be very popular in South Korea. Conventional western medical doctors and governments should obtain more evidence and become more interested in CAM therapies

Three cases of glycogenic hepatopathy mimicking acute and relapsing hepatitis in type I diabetes mellitus

Glycogenic hepatopathy (GH) is an uncommon cause of serum transaminase elevation in type I diabetes mellitus (DM). The clinical signs and symptoms of GH are nonspecific, and include abdominal discomfort, mild hepatomegaly, and transaminase elevation. In this report we describe three cases of patients presenting serum transaminase elevation and hepatomegaly with a history of poorly controlled type I DM. All of the cases showed sudden elevation of transaminase to more than 30 times the upper normal range (like in acute hepatitis) followed by sustained fluctuation (like in relapsing hepatitis). However, the patients did not show any symptom or sign of acute hepatitis. We therefore performed a liver biopsy to confirm the cause of liver enzyme elevation, which revealed GH. Clinicians should be aware of GH so as to prevent diagnostic delay and misdiagnosis, and have sufficient insight into GH; this will be aided by the present report of three cases along with a literature review

The Relationship Between Coronary Artery Calcification and Bone Mineral Density in Patients According to Their Metabolic Syndrome Status

Background and Objectives: The extent of coronary artery calcification (CAC) is closely related to total atherosclerotic plaque burden. However, the pathogenesis of CAC is still unclear. Conditions such as diabetes mellitus, renal failure, smoking, and chronic inflammation have been suggested to link vascular calcification and bone loss. In the present study, we hypothesized that bone loss can contribute to the pathogenesis of CAC in patients with the chronic inflammatory condition that accompanies metabolic syndrome (MetS). The objective of this study was to investigate the relationship between CAC and bone mineral density (BMD) in patients with MetS and in patients without MetS, by using coronary multidetector-row computed tomography (MDCT). Subjects and Methods: Data from 395 consecutive patients was analyzed retrospectively. From the MDCT database, only those patients who underwent both coronary MDCT and dual-energy X-ray absorptiometry within an interval of one month, were selected. The presence of MetS was determined by the updated criteria as defined by the Third Adult Treatment Panel Report of the National Cholesterol Education Program. Results: In patients with MetS, a significant correlation was found between CAC and age {odds ratio (OR)=1.139, 95% confidence interval (CI) 1.080 to 1.201, p&lt;0.001}, CAC and male sex (OR=3.762, 95% CI 1.339 to 10.569, p=0.012), and CAC and T-score of L-spine (OR=0.740, 95% CI 0.550 to 0.996, p=0.047) using a forward multiple logistic regression analysis model including clinical variables of gender, age, lipid profile, body mass index, diabetes mellitus, hypertension, smoking, and BMD. But in patients without MetS, BMD by itself was not found to contribute to CAC. Conclusion: BMD was inversely correlated with CAC only in patients with MetS. This finding suggests that low BMD accompanied by MetS, may have significant clinical implications

Predictive factors of contrast-enhanced ultrasonography for the response to transarterial chemoembolization in hepatocellular carcinoma

Background/AimsThe predictive role of contrast-enhanced ultrasonography (CEUS) before performing transarterial chemoembolization (TACE) has not been determined. We assessed the possible predictive factors of CEUS for the response to TACE.MethodsSeventeen patients with 18 hepatocellular carcinoma (HCC) underwent TACE. All of the tumors were studied with CEUS before TACE using a second-generation ultrasound contrast agent (SonoVue®, Bracco, Milan, Italy). The tumor response to TACE was classified with a score between 1 and 4 according to the remaining enhancing-tumor percentage based on modified response evaluation criteria in solid tumors (mRECIST): 1, enhancing tumor <25%; 2, 25%≤enhancing tumor<50%; 3, 50%≤enhancing tumor<75%; and 4, enhancing tumor≥75%). A score of 1 was defined as a "good response" to TACE. The predictive factors for the response to TACE were evaluated during CEUS based on the maximum tumor diameter, initial arterial enhancing time, arterial enhancing duration, intensity of arterial enhancement, presence of a hypoenhanced pattern, and the feeding artery to the tumor.ResultsThe median tumor size was 3.1 cm. The distribution of tumor response scores after TACE in all tumors was as follows: 1, n=11; 2, n=4; 3, n=2; and 4, n=1. Fifteen tumors showed feeding arteries. The presence of a feeding artery and the tumor size (≤5 cm) were the predictive factors for a good response (P=0.043 and P=0.047, respectively).ConclusionsThe presence of a feeding artery and a tumor size of less than 5 cm were the predictive factors for a good response of HCC to TACE on CEUS