267 research outputs found
The Pharmacological Effects and Pharmacokinetics of Active Compounds of Artemisia capillaris.
Artemisia capillaris Thunb. (A.capillaris, Yin-Chen in Chinese) is a traditional medicinal herb with a wide spectrum of pharmacological properties ranging from effects against liver dysfunction to treatments of severe cirrhosis and cancer. We used relevant keywords to search electronic databases, including PubMed, Medline, and Google Scholar, for scientific contributions related to this medicinal herb and the pharmacokinetics of its components. The pharmaceutical effects of A.capillaris contribute to the treatment not only of viral hepatitis, cirrhosis, and hepatocellular hepatoma, but also metabolic syndrome, psoriasis, and enterovirus in the clinic. The bioactive compounds, including scoparone, capillarisin, scopoletin, and chlorogenic acid, exhibit antioxidant, anti-inflammatory, antisteatotic, antiviral, and antitumor properties, reflecting the pharmacological effects of A.capillaris. The pharmacokinetics of the main bioactive compounds in A. capillaris can achieve a maximum concentration within 1 hour, but only chlorogenic acid has a relatively long half-life. Regarding the use of the A. capillaris herb by health professionals to treat various diseases, the dosing schedule of this herb should be carefully considered to maximize therapeutic outcomes while lessening possible side effects
Ecological Modeling of Aedes aegypti (L.) Pupal Production in Rural Kamphaeng Phet, Thailand
Background - Aedes aegypti (L.) is the primary vector of dengue, the most important arboviral infection globally. Until an effective vaccine is licensed and rigorously administered, Ae. aegypti control remains the principal tool in preventing and curtailing dengue transmission. Accurate predictions of vector populations are required to assess control methods and develop effective population reduction strategies. Ae. aegypti develops primarily in artificial water holding containers. Release recapture studies indicate that most adult Ae. aegypti do not disperse over long distances. We expect, therefore, that containers in an area of high development site density are more likely to be oviposition sites and to be more frequently used as oviposition sites than containers that are relatively isolated from other development sites. After accounting for individual container characteristics, containers more frequently used as oviposition sites are likely to produce adult mosquitoes consistently and at a higher rate. To this point, most studies of Ae. aegypti populations ignore the spatial density of larval development sites. Methodology - Pupal surveys were carried out from 2004 to 2007 in rural Kamphaeng Phet, Thailand. In total, 84,840 samples of water holding containers were used to estimate model parameters. Regression modeling was used to assess the effect of larval development site density, access to piped water, and seasonal variation on container productivity. A varying-coefficients model was employed to account for the large differences in productivity between container types. A two-part modeling structure, called a hurdle model, accounts for the large number of zeroes and overdispersion present in pupal population counts. Findings - The number of suitable larval development sites and their density in the environment were the primary determinants of the distribution and abundance of Ae. aegypti pupae. The productivity of most container types increased significantly as habitat density increased. An ecological approach, accounting for development site density, is appropriate for predicting Ae. aegypti population levels and developing efficient vector control program
Population density, water supply, and the risk of dengue fever in Vietnam: cohort study and spatial analysis.
BACKGROUND: Aedes aegypti, the major vector of dengue viruses, often breeds in water storage containers used by households without tap water supply, and occurs in high numbers even in dense urban areas. We analysed the interaction between human population density and lack of tap water as a cause of dengue fever outbreaks with the aim of identifying geographic areas at highest risk. METHODS AND FINDINGS: We conducted an individual-level cohort study in a population of 75,000 geo-referenced households in Vietnam over the course of two epidemics, on the basis of dengue hospital admissions (n = 3,013). We applied space-time scan statistics and mathematical models to confirm the findings. We identified a surprisingly narrow range of critical human population densities between around 3,000 to 7,000 people/km² prone to dengue outbreaks. In the study area, this population density was typical of villages and some peri-urban areas. Scan statistics showed that areas with a high population density or adequate water supply did not experience severe outbreaks. The risk of dengue was higher in rural than in urban areas, largely explained by lack of piped water supply, and in human population densities more often falling within the critical range. Mathematical modeling suggests that simple assumptions regarding area-level vector/host ratios may explain the occurrence of outbreaks. CONCLUSIONS: Rural areas may contribute at least as much to the dissemination of dengue fever as cities. Improving water supply and vector control in areas with a human population density critical for dengue transmission could increase the efficiency of control efforts. Please see later in the article for the Editors' Summary
Case report: Infective endocarditis caused by Brevundimonas vesicularis
BACKGROUND: There are few reports in the literature of invasive infection caused by Brevundimonas vesicularis in patients without immunosuppression or other predisposing factors. The choice of antimicrobial therapy for bacteremia caused by the pathogen requires more case experience to be determined. CASE PRESENTATION: The case of a 40-year-old previously healthy man with subacute endocarditis proposed to be contributed from an occult dental abscess is described. The infection was found to be caused by B. vesicularis on blood culture results. The patient recovered without sequelae after treatment with ceftriaxone followed by subsequent ciprofloxacin therapy owing to an allergic reaction to ceftriaxone and treatment failure with ampicillin/sulbactam. CONCLUSION: To our knowledge, this is the first report of B. vesicularis as a cause of infective endocarditis. According to an overview of the literature and our experience, we suggest that third-generation cephalosporins, piperacillin/tazobactam, and ciprofloxacin are effective in treating invasive B. vesicularis infections, while the efficacy of ampicillin-sulbactam needs further evaluation
Risk of dengue occurrence based on the capture of gravid Aedes aegypti females using MosquiTRAP
We assessed the risk classification of dengue fever based on the capture of Aedes aegypti adults using MosquiTRAP, a type of sticky trap, in comparison with traditional larval infestation indices. A total of 27 MosquiTRAPs were installed, with one trap per block, and were inspected weekly between November 2008-February 2009. Infestation baseline data were obtained from a survey conducted prior to trap installation. The index generated by MosquiTRAP and house index (HI) classified the area "in alert situation". The set for risk of dengue occurrence proposed by the use of MosquiTRAP classify areas in the same way of the traditional HI
Defining Challenges and Proposing Solutions for Control of the Virus Vector Aedes aegypti
If done properly, say the authors,Aedes aegypti suppression is a practical method to control urban dengue, yellow fever, and chikungunya viruses
Connectivity of Default-Mode Network Is Associated with Cerebral Edema in Hepatic Encephalopathy
Cerebral edema, a well-known feature of acute liver disease, can occur in cirrhotic patients regardless of hepatic encephalopathy (HE) and adversely affect prognosis. This study characterized and correlated functional HE abnormalities in the brain to cerebral edema using resting-state functional magnetic resonance imaging (rs-fMRI) and diffusion tensor imaging (DTI). Forty-one cirrhotic patients (16 without HE, 14 minimal HE, 11 overt HE) and 32 healthy controls were assessed. The HE grade in cirrhotic patients was evaluated by the West Haven criteria and neuro-psychological examinations. Functional connectivity correlation coefficient (fc-CC) of the default mode network (DMN) was determined by rs-fMRI, while the corresponding mean diffusivity (MD) was obtained from DTI. Correlations among inter-cortical fc-CC, DTI indices, Cognitive Ability Screening Instrument scores, and laboratory tests were also analyzed. Results showed that gradual reductions of HE-related consciousness levels, from “without HE” or “minimal HE” to “overt HE”, correlated with decreased anterior-posterior fc-CC in DMN [F(4.415), p = 0.000)]. The MD values from regions with anterior-posterior fc-CC differences in DMN revealed significant differences between the overt HE group and other groups. Increased MD in this network was inversely associated with decreased fc-CC in DMN and linearly correlated with poor cognitive performance. In conclusion, cerebral edema can be linked to altered cerebral temporal architecture that modifies both within- and between-network connectivity in HE. Reduced fc-CC in DMN is associated with behavior and consciousness deterioration. Through appropriate targets, rs-fMRI technology may provide relevant supplemental information for monitoring HE and serve as a new biomarker for clinical diagnosis
Oviposition Site Selection by the Dengue Vector Aedes aegypti and Its Implications for Dengue Control
Controlling the mosquito Aedes aegypti is of public health importance because, at present, it is the only means to stop dengue virus transmission. Implementing successful mosquito control programs requires understanding what factors regulate population abundance, as well as anticipating how mosquitoes may adapt to control measures. In some species of mosquitoes, females choose egg-laying sites to improve the survival and growth of their offspring, a behavior that ultimately influences population distribution and abundance. In the current study, we tested whether Ae. aegypti actively choose the containers in which they lay their eggs and determined what cues are most relevant to that process. We also explored whether females select containers that provide the most food for their larval progeny. Surprisingly, egg-laying females were most attracted to sites containing other immature Ae. aegypti, rather than to sites containing the most food. We propose that this behavior may contribute to density-dependent competition for food among larvae and play a larger role than previously thought in regulating Ae. aegypti populations. We recommend that accounting for, and even taking advantage of, this natural behavior will lead to more effective strategies for dengue prevention
Australia's Dengue Risk Driven by Human Adaptation to Climate Change
Current and projected rainfall reduction in southeast Australia has seen the installation of large numbers of government-subsidised and ad hoc domestic water storage containers that could create the possibility of the mosquito Ae. aegypti expanding out of Queensland into southern Australian's urban regions. By assessing the past and current distribution of Ae. aegypti in Australia, we construct distributional models for this dengue vector for our current climate and projected climates for 2030 and 2050. The resulting mosquito distribution maps are compared to published theoretical temperature limits for Ae. aegypti and some differences are identified. Nonetheless, synthesising our mosquito distribution maps with dengue transmission climate limits derived from historical dengue epidemics in Australia suggests that the current proliferation of domestic water storage tanks could easily result in another range expansion of Ae. aegypti along with the associated dengue risk were the virus to be introduced
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