786 research outputs found

    A Novel Two-Component Response Regulator Links rpfwith Biofilm Formation and Virulence of Xanthomonasaxonopodis pv. Citri

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    Citrus bacterial canker caused by Xanthomonas axonopodis pv. citri is a serious disease that impacts citrus productionworldwide, and X. axonopodis pv. citri is listed as a quarantine pest in certain countries. Biofilm formation is important forthe successful development of a pathogenic relationship between various bacteria and their host(s). To understand themechanisms of biofilm formation by X. axonopodis pv. citri strain XW19, the strain was subjected to transposonmutagenesis. One mutant with a mutation in a two-component response regulator gene that was deficient in biofilmformation on a polystyrene microplate was selected for further study. The protein was designated as BfdR for biofilmformation defective regulator. BfdR from strain XW19 shares 100% amino acid sequence identity with XAC1284 of X.axonopodis pv. citri strain 306 and 30–100% identity with two-component response regulators in various pathogens andenvironmental microorganisms. The bfdR mutant strain exhibited significantly decreased biofilm formation on the leafsurfaces of Mexican lime compared with the wild type strain. The bfdR mutant was also compromised in its ability to causecanker lesions. The wild-type phenotype was restored by providing pbfdR in trans in the bfdR mutant. Our data indicatedthat BfdR did not regulate the production of virulence-related extracellular enzymes including amylase, lipase, protease, andlecithinase or the expression of hrpG, rfbC, and katE; however, BfdR controlled the expression of rpfF in XVM2 medium,which mimics cytoplasmic fluids in planta. In conclusion, biofilm formation on leaf surfaces of citrus is important for cankerdevelopment in X. axonopodis pv. citri XW19. The process is controlled by the two-component response regulator BfdR viaregulation of rpfF, which is required for the biosynthesis of a diffusible signal factor

    Driving Control Technologies of New High-Efficient Motors

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    Although switched-reluctance machine (SRM) possesses many structural advantages and application potential, it is rather difficult to successfully control with high performance being comparable to other machines. Many critical affairs must be properly treated to obtain the improved operating characteristics. This chapter presents the basic and key technologies of switched-reluctance machine in motor and generator operations. The contents in this chapter include: (1) structures and governing equations of SRM; (2) some commonly used SRM converters; (3) estimation of key parameters and performance evaluation of SRM drive; (4) commutation scheme, current control scheme, and speed control scheme of SRM drive; (5) some commonly used front-end converters and their operation controls for SRM drive; (6) reversible and regenerative braking operation controls for SRM drive; (7) some tuning issues for SRM drive; (8) operation control and some tuning issues of switched-reluctance generators; and (9) experimental application exploration for SRM systems: (a) wind generator and microgrid; (b) EV SRM drive

    Small trocar site hernia after laparoscopy

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    AbstractThis review article is attempted to review the cases of 5-mm trocar site hernias (TSHs) after laparoscopic surgery and identify the risks associated with incarceration. We searched the English literature on the PubMed website using the key words “trocar site hernia” and “5 mm”. We evaluated a total of 24 cases of 5-mm TSHs and analyzed and results showed that 17 (71%) and 7 (29%) resulted from gynecologic and gastrointestinal surgeries, respectively. The majority were found at the lateral abdomen (87.5%) and recognized within 2 weeks (87.5%). The most frequently herniated organ (n = 14) was the small bowel. Up to 62.5% of cases (n = 15) were repaired by exploratory laparotomy, and 25% (n = 6) required resection of herniated organs secondary to incarceration. The cases with incarceration were detected at 4.3 ± 2.2 days post-operation and those without incarceration at 47.4 days post-operation. No risk factors could be identified to show a correlation between 5-mm TSHs and incarceration. We concluded that immediate 1--2-week postoperative care is of most importance, since the majority of 5-mm trocar site hernias with or without incarceration occurred within this period

    Some Basic and Key Issues of Switched-Reluctance Machine Systems

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    Although switched-reluctance machine (SRM) possesses many structural advantages and application potential, it is rather difficult to successfully control with high performance being comparable to other machines. Many critical affairs must be properly treated to obtain the improved operating characteristics. This chapter presents the basic and key technologies of switched-reluctance machine in motor and generator operations. The contents in this chapter include: (1) structures and governing equations of SRM; (2) some commonly used SRM converters; (3) estimation of key parameters and performance evaluation of SRM drive; (4) commutation scheme, current control scheme, and speed control scheme of SRM drive; (5) some commonly used front-end converters and their operation controls for SRM drive; (6) reversible and regenerative braking operation controls for SRM drive; (7) some tuning issues for SRM drive; (8) operation control and some tuning issues of switched-reluctance generators; and (9) experimental application exploration for SRM systems—(a) wind generator and microgrid and (b) EV SRM drive

    The incidence and risk of developing a second primary esophageal cancer in patients with oral and pharyngeal carcinoma: a population-based study in Taiwan over a 25 year period

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    <p>Abstract</p> <p>Background</p> <p>The incidence of oral and pharyngeal (including oral cavity, oropharynx and hypopharynx) carcinoma increases rapidly in Asia and South Pacific because of betel quid chewing. Thus far, large-scale epidemiological studies are not available yet to stratify these patients by their risks of developing a second primary cancer in the digestive tract including esophagus, stomach, colon, and rectum.</p> <p>Methods</p> <p>A population-based study was conducted using the database from the Taiwan National Cancer Registry for the period 1979-2003. We quantified standardized incidence ratios (SIRs) and cumulative incidence of second primary cancers among 33,787 patients with initial diagnoses of oral and pharyngeal carcinoma.</p> <p>Results</p> <p>Among these four digestive tract organs, the esophagus was the only site of second cancer with excess risk in patients with oral and pharyngeal carcinoma. The incidence and risk of developing a second primary esophageal cancer differed by the site of the primary index tumor, most frequently seen in hypopharyngeal cancer (71/4,218 = 1.68%, SIR = 22.76, 95% CI 17.77-28.70), followed by oropharyngeal cancer (30/3,403 = 0.88%, SIR = 14.29, 95% CI 9.64-20.39) and the least in oral cavity cancer (99/26,166 = 0.38%, SIR = 5.57, 95% CI 4.53-6.78). In addition, the risk was extraordinarily high for patients with a follow-up interval ≤ 1 year and those with first primary cancer diagnosed at age ≤50. These patients may justify more close surveillance.</p> <p>Conclusion</p> <p>The present study represents the first population-based study in Asia attempting to stratify the patients of oral and pharyngeal carcinoma by their risk of developing a second esophageal cancer. It helps identify patients at high risk and tailor the application of intense follow-up surveillance to the estimated risk in each individual case.</p

    Correlation of Interleukin-17-Producing Effector Memory T Cells and CD4 +

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    Background and Objectives. Hyperparathyroidism and hyperphosphatemia contribute to the inflammatory effects in chronic hemodialysis (HD) patients. Interleukin-17-producing CD4+ effector memory T (Th17) cells and CD4+CD25+Foxp3 regulatory T (Treg) cells both play critical roles in immune activation and inflammation. We investigated the relationship between the Treg and Th17 cells and the phosphate level in chronic HD patients. Methods. 105 patients aged ≥35 years on chronic HD over 3 months were enrolled. The peripheral blood mononuclear cells were collected, cultured, and stimulated by phytohemagglutinin-L, phorbol myristate acetate, and ionomycin at different time points for T cell differentiation. Results. The T cell differentiation was as follows: Th17 cells (mean ± standard deviation (SD): 25.61% ± 10.2%) and Treg cells (8.45% ± 4.3%). The Th17 cell differentiation was positively correlated with the phosphate and albumin levels and negatively correlated with age. The Treg cell differentiation was negatively correlated with albumin level and age. In the nondiabetes group (n=53), the Th17 cell differentiation was predominantly correlated with the phosphate and iPTH (intact parathyroid hormone) levels as well as the dialysis vintage. Conclusion. Higher phosphate and iPTH levels and longer dialysis duration may increase Th17 cell differentiation, especially in the nondiabetic chronic HD patients

    Synergistic Apoptosis-Inducing Antileukemic Effects of Arsenic Trioxide and Mucuna macrocarpa

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    The objective of this study was to examine the potential of enhancing the antileukemic activity of arsenic trioxide (ATO) by combining it with a folk remedy, crude methanolic extract of Mucuna macrocarpa (CMEMM). Human leukemia cells HL-60, Jurkat, and Molt-3 were treated with various doses of ATO, CMEMM, and combinations thereof for 24 and 48 h. Results indicated that the combination of 2.5 μM ATO and 50 μg/mL CMEMM synergistically inhibited cell proliferation in HL-60 and Jurkat cell lines. Apoptosis triggered by ATO/CMEMM treatment was confirmed by accumulation of cells in the sub-G1 phase in cell cycle analyses, characteristic apoptotic nuclear fragmentation, and increased percentage of annexin V-positive apoptotic cells. Such combination treatments also led to elevation of reactive oxygen species (ROS). The antioxidants N-acetyl cysteine (NAC), butylated hydroxytoluene, and α-tocopherol prevented cells from ATO/CMEMM-induced apoptosis. The ATO/CMEMM-induced activation of caspase-3 and caspase-9 can be blocked by NAC. In summary, these results suggest that ATO/CMEMM combination treatment exerts synergistic apoptosis-inducing effects in human leukemic cells through a ROS-dependent mechanism and may provide a promising antileukemic approach in the future

    A Nationwide Population-Based Cohort Study: Will Anxiety Disorders Increase Subsequent Cancer Risk?

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    BACKGROUND: The aim of this study was to evaluate a possible association between malignancy and anxiety disorders (AD) in Taiwan. METHODS: We employed data from the National Health Insurance system of Taiwan. The AD cohort contained 24,066 patients with each patient randomly frequency matched according to age and sex with 4 individuals from the general population without AD. Cox's proportional hazard regression analysis was conducted to estimate the influence of AD on the risk of cancer. RESULTS: Among patients with AD, the overall risk of developing cancer was only 1% higher than among subjects without AD, and the difference was not significant (hazard ratio [HR] = 1.01, 95% confidence interval [95% CI] = 0.95-1.07). With regard to individual types of cancer, the risk of developing prostate cancer among male patients with AD was significantly higher (HR = 1.32, 95% CI = 1.02-1.71). On the other hand, the risk of cervical cancer among female patients with AD was marginally significantly lower than among female subjects without AD (HR = 0.72, 95% CI = 0.51-1.03). LIMITATIONS: One major limitation is the lack of information regarding the life style or behavior of patients in the NHI database, such as smoking and alcohol consumption. CONCLUSIONS: Despite the failure to identify a relationship between AD and the overall risk of cancer, we found that Taiwanese patients with AD had a higher risk of developing prostate cancer and a lower risk of developing cervical cancer

    Women with endometriosis have higher comorbidities: Analysis of domestic data in Taiwan

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    AbstractEndometriosis, defined by the presence of viable extrauterine endometrial glands and stroma, can grow or bleed cyclically, and possesses characteristics including a destructive, invasive, and metastatic nature. Since endometriosis may result in pelvic inflammation, adhesion, chronic pain, and infertility, and can progress to biologically malignant tumors, it is a long-term major health issue in women of reproductive age. In this review, we analyze the Taiwan domestic research addressing associations between endometriosis and other diseases. Concerning malignant tumors, we identified four studies on the links between endometriosis and ovarian cancer, one on breast cancer, two on endometrial cancer, one on colorectal cancer, and one on other malignancies, as well as one on associations between endometriosis and irritable bowel syndrome, one on links with migraine headache, three on links with pelvic inflammatory diseases, four on links with infertility, four on links with obesity, four on links with chronic liver disease, four on links with rheumatoid arthritis, four on links with chronic renal disease, five on links with diabetes mellitus, and five on links with cardiovascular diseases (hypertension, hyperlipidemia, etc.). The data available to date support that women with endometriosis might be at risk of some chronic illnesses and certain malignancies, although we consider the evidence for some comorbidities to be of low quality, for example, the association between colon cancer and adenomyosis/endometriosis. We still believe that the risk of comorbidity might be higher in women with endometriosis than that we supposed before. More research is needed to determine whether women with endometriosis are really at risk of these comorbidities
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