351 research outputs found
Spatial-temporal analysis of malaria and the effect of environmental factors on its incidence in Yongcheng, China, 2006–2010
BACKGROUND: In 2003, Plasmodium vivax malaria has re-emerged in central eastern China including Yongcheng prefecture, Henan Province, where no case has been reported for eleven years. Our goals were to detect the space-time distribution pattern of malaria and to determine significant environmental variables contributing to malaria incidence in Yongcheng from 2006 to 2010, thus providing scientific basis for further optimizing current malaria surveillance and control programs. METHODS: This study examined the spatial and temporal heterogeneities in the risk of malaria and the influencing factors on malaria incidence using geographical information system (GIS) and time series analysis. Univariate analysis was conducted to estimate the crude correlations between malaria incidence and environmental variables, such as mosquito abundance and climatic factors. Multivariate analysis was implemented to construct predictive models to explore the principal environmental determinants on malaria epidemic using a Generalized Estimating Equation (GEE) approach. RESULTS: Annual malaria incidence at town-level decreased from the north to south, and monthly incidence at prefecture-level demonstrated a strong seasonal pattern with a peak from July to November. Yearly malaria incidence had a visual spatial association with yearly average temperature. Moreover, the best-fit temporal model (model 2) (QIC = 16.934, P<0.001, R(2) = 0.818) indicated that significant factors contributing to malaria incidence were maximum temperature at one month lag, average humidity at one month lag, and malaria incidence of the previous month. CONCLUSIONS: Findings supported the effects of environment factors on malaria incidence and indicated that malaria control targets should vary with intensity of malaria incidence, with more public resource allocated to control the source of infections instead of large scale An. sinensis control when malaria incidence was at a low level, which would benefit for optimizing the malaria surveillance project in China and some other countries with unstable or low malaria transmission
Ligustrazine Inhibits the Migration and Invasion of Renal Cell Carcinoma
Ligustrazine is a Chinese herb (Chuanxiong) approved for use as a medical drug in China. Recent evidence suggests that ligustrazine has promising antitumor properties. Our preliminary results showed that ligustrazine could inhibit the growth of human renal cell carcinoma (RCC) cell lines. However, the complicated molecular mechanism has not been fully revealed. Therefore, the purpose of this study to investigate the mechanism of ligustrazine resistance in human RCC cells. Cell proliferation, migration, invasion, and colony-formation ability of RCC cells A498 were detected by MTT assay, clonal formation rates, and transwell chamber assay in vitro. The expression of epithelial–mesenchymal transition (EMT)–related proteins were analyzed using western blot test. The effect of ligustrazine on the growth of A498 cells in nude mice was investigated in vivo. Our results showed that ligustrazine could significantly inhibit the proliferation, migration, and invasion of A498 both in vivo and vitro. Western blot analysis showed that the expressions of EMT-related, N-cadherin, snail, and slug proteins were significantly decreased in A498 in the ligustrazine treatment group. This study indicated that ligustrazine could significantly inhibit the malignant biological behaviors of RCC cell lines, possibly by inhibiting the EMT process
Inhibition of Drug Resistance of Staphylococcus aureus by Efflux Pump Inhibitor and Autolysis Inducer to Strengthen the Antibacterial Activity of β-lactam Drugs
Sensitivity enhancement of a Cu (II) metal organic framework-acetylene black-based electrochemical sensor for ultrasensitive detection of imatinib in clinical samples
Imatinib (IMB), an anticancer drug, is extensively used for chemotherapy to improve the quality of life of cancer patients. The aim of therapeutic drug monitoring (TDM) is to guide and evaluate the medicinal therapy, and then optimize the clinical effect of individual dosing regimens. In this work, a highly sensitive and selective electrochemical sensor based on glassy carbon electrode (GCE) modified with acetylene black (AB) and a Cu (II) metal organic framework (CuMOF) was developed to measure the concentration of IMB. CuMOF with preferable adsorbability and AB with excellent electrical conductivity functioned cooperatively to enhance the analytical determination of IMB. The modified electrodes were characterized using X-rays diffraction (XRD), X-ray photoelectron spectroscopy (XPS), fourier transform infrared (FT-IR), ultraviolet and visible spectrophotometry (UV-vis), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), energy dispersive X‐ray spectroscopy (EDS), brunauer‒emmett‒teller (BET) and barrett‒joyner‒halenda (BJH) techniques. Analytical parameters such as the ratio of CuMOF to AB, dropping volumes, pH, scanning rate and accumulation time were investigated through cyclic voltammetry (CV). Under optimal conditions, the sensor exhibited an excellent electrocatalytic response for IMB detection, and two linear detection ranges were obatined of 2.5 nM-1.0 μM and 1.0–6.0 μM with a detection limit (DL) of 1.7 nM (S/N = 3). Finally, the good electroanalytical ability of CuMOF-AB/GCE sensor facilitated the successful determination of IMB in human serum samples. Due to its acceptable selectivity, repeatability and long-term stability, this sensor shows promising application prospects in the detection of IMB in clinical samples
Ligustrazine Inhibits the Migration and Invasion of Renal Cell Carcinoma
Ligustrazine is a Chinese herb (Chuanxiong) approved for use as a medical drug in China. Recent evidence suggests that ligustrazine has promising antitumor properties. Our preliminary results showed that ligustrazine could inhibit the growth of human renal cell carcinoma (RCC) cell lines. However, the complicated molecular mechanism has not been fully revealed. Therefore, the purpose of this study to investigate the mechanism of ligustrazine resistance in human RCC cells. Cell proliferation, migration, invasion, and colony-formation ability of RCC cells A498 were detected by MTT assay, clonal formation rates, and transwell chamber assay in vitro. The expression of epithelial–mesenchymal transition (EMT)–related proteins were analyzed using western blot test. The effect of ligustrazine on the growth of A498 cells in nude mice was investigated in vivo. Our results showed that ligustrazine could significantly inhibit the proliferation, migration, and invasion of A498 both in vivo and vitro. Western blot analysis showed that the expressions of EMT-related, N-cadherin, snail, and slug proteins were significantly decreased in A498 in the ligustrazine treatment group. This study indicated that ligustrazine could significantly inhibit the malignant biological behaviors of RCC cell lines, possibly by inhibiting the EMT process
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Encroachment order and spatial patterns of broad-leaf tree species in the naturalization of a Cunninghamia lanceolata plantation
Authors of the article state that the aim of this study was to understand the encroachment order, spatial patterns, interspecific associations, and species diversity of a Cunninghamia lanceolata plantation and to provide context for how to improve the spatial structure of C. lanceolata plantations. Their results show that the encroachment of broad-leaf trees into the C. lanceolata plantation followed a clear successional sequence of tree community assembly: intolerant tree species encroachment first, such as Alniphyllum fortunei and Liquidambar formosana, encroached; neutral tree species then encroachment, such as Daphniphyllum oldhamii and Schima superba, and shade-tolerant tree species encroachment last, such as Castanopsis eyrei and Castanopsis tibetana
The TRAPs From Microglial Vesicles Protect Against Listeria Infection in the CNS
Previous studies have demonstrated that T cells and microglia could fight against cerebral Listeria monocytogenes (Listeria); however, their synergistic anti-Listeria mechanisms remain unknown. Following Listeria infection in a culture system, we found that microglia, but not nerve cells, could release extracellular traps (ETs) which originated from microglial vesicles. Specific inhibitor analysis showed that extracellular DNA (eDNA), matrix metallopeptidases (MMP9 and MMP12), citrullinated histone H3, and peptidyl arginine deiminase 2 were the major components of microglial ETs (MiETs) and were also the components of vesicles. Systematic analysis indicated that Listeria-induced MiETs were cytosolic reactive oxygen species (ROS)- and NADPH oxidase (NOX)-dependent and involved ERK. MiETs were exhibited in Listeria-infected mouse brain and might protected against Listeria infection via bacterial killing in a mouse meningitis model, and MiETs existed in cerebrospinal fluid (CSF) from Listeria meningitis patients in vivo and in vitro. Additionally, interferon-γ could induce MiET formation in Listeria-infected microglia in vitro that was mediated by NOX, and there was a positive relationship between the elevated level of IFN-γ and eDNA and nucleosomes in the brain homogenates and CSF of Listeria meningitis model mice and in the CSF before treatment in clinical Listeria meningitis patients. Together, this is the first report of MiET formation, these findings pave the way for deeper exploration of the innate immune response to pathogens in CNS
A preclinical platform for assessing antitumor effects and systemic toxicities of cancer drug targets
SignificanceMany new cancer drugs fail at the clinical stage owing to poor efficacy and/or excessive toxicity, though whether this reflects shortcomings of the target or the drug is often unclear. To gain earlier insights into factors that can influence the therapeutic index of target inhibition in vivo, we combine inducible RNA interference and somatic engineering technologies to produce a cost-effective platform that enables systemic and inducible suppression of candidate target in normal tissues and tumor cells in the same mouse. By comparing the consequences of genetic and pharmacological CDK9 inhibition, we establish the utility of this platform to predict factors influencing the therapeutic index. Additionally, our studies provide support, and some cautionary notes, for the clinical development of CDK9 inhibitors
Longitudinal seroepidemiologic study of the 2009 pandemic influenza A (H1N1) infection among health care workers in a children's hospital
<p>Abstract</p> <p>Background</p> <p>To probe seroepidemiology of the 2009 pandemic influenza A (H1N1) among health care workers (HCWs) in a children's hospital.</p> <p>Methods</p> <p>From August 2009 to March 2010, serum samples were drawn from 150 HCWs in a children's hospital in Taipei before the 2009 influenza A (H1N1) pandemic, before H1N1 vaccination, and after the pandemic. HCWs who had come into direct contact with 2009 influenza A (H1N1) patients or their clinical respiratory samples during their daily work were designated as a high-risk group. Antibody levels were determined by hemagglutination inhibition (HAI) assay. A four-fold or greater increase in HAI titers between any successive paired sera was defined as seroconversion, and factors associated with seroconversion were analyzed.</p> <p>Results</p> <p>Among the 150 HCWs, 18 (12.0%) showed either virological or serological evidence of 2009 pandemic influenza A (H1N1) infection. Of the 90 unvaccinated HCWs, baseline and post-pandemic seroprotective rates were 5.6% and 20.0%. Seroconversion rates among unvaccinated HCWs were 14.4% (13/90), 22.5% (9/40), and 8.0% (4/50) for total, high-risk group, and low-risk group, respectively. Multivariate analysis revealed being in the high-risk group is an independent risk factor associated with seroconversion.</p> <p>Conclusion</p> <p>The infection rate of 2009 pandemic influenza A (H1N1) in HCWs was moderate and not higher than that for the general population. The majority of unvaccinated HCWs remained susceptible. Direct contact of influenza patients and their respiratory samples increased the risk of infection.</p
An outbreak of coxsackievirus A6 hand, foot, and mouth disease associated with onychomadesis in Taiwan, 2010
<p>Abstract</p> <p>Background</p> <p>In 2010, an outbreak of coxsackievirus A6 (CA6) hand, foot and mouth disease (HFMD) occurred in Taiwan and some patients presented with onychomadesis and desquamation following HFMD. Therefore, we performed an epidemiological and molecular investigation to elucidate the characteristics of this outbreak.</p> <p>Methods</p> <p>Patients who had HFMD with positive enterovirus isolation results were enrolled. We performed a telephone interview with enrolled patients or their caregivers to collect information concerning symptoms, treatments, the presence of desquamation, and the presence of nail abnormalities. The serotypes of the enterovirus isolates were determined using indirect immunofluorescence assays. The VP1 gene was sequenced and the phylogenetic tree for the current CA6 strains in 2010, 52 previous CA6 strains isolated in Taiwan from 1998 through 2009, along with 8 reference sequences from other countries was constructed using the neighbor-joining command in MEGA software.</p> <p>Results</p> <p>Of the 130 patients with laboratory-confirmed CA6 infection, some patients with CA6 infection also had eruptions around the perioral area (28, 22%), the trunk and/or the neck (39, 30%) and generalized skin eruptions (6, 5%) in addition to the typical presentation of skin eruptions on the hands, feet, and mouths. Sixty-six (51%) CA6 patients experienced desquamation of palms and soles after the infection episode and 48 (37%) CA6 patients developed onychomadesis, which only occurred in 7 (5%) of 145 cases with non-CA6 enterovirus infection (<it>p </it>< 0.001). The sequences of viral protein 1 of CA6 in 2010 differ from those found in Taiwan before 2010, but are similar to those found in patients in Finland in 2008.</p> <p>Conclusions</p> <p>HFMD patients with CA6 infection experienced symptoms targeting a broader spectrum of skin sites and more profound tissue destruction, i.e., desquamation and nail abnormalities.</p
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