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The green alga Caulerpa microphysa, which is native to Taiwan, has a relatively high economic value and a well-developed culture technique, and is used mainly as a foodstuff. Its extract has been shown to exhibit antitumor properties, but the polysaccharide content of the extract and its anti-inflammatory and wound-healing effects and moisture-absorption and -retention capacity remain unknown. Hence, the objective of this study was to evaluate the potential of the polysaccharides in C. microphysa extract (CME) for use in cosmetics. The overall polysaccharide yield from the CME was 73.93% w/w, with four molecular weight fractions. The polysaccharides comprised 59.36 mol% mannose, 27.16 mol% glucose, and 13.48 mol% galactose. In addition, the CME exhibited strong antiallergic, wound-healing, transdermal-delivery, and moisture-absorption and -retention effects. In conclusion, the results suggested that CME potentially has anti-inflammatory and wound-healing effects and a good moisture capacity, which can be used in cosmetic applications. 相似文献
183.
Biochemically, nonylphenol ethoxylates (NPnEOs) and its breakdown products nonylphenol (NP), NP monoethoxylate (NP1EO), and NP diethoxylate (NP2EO) are considered endocrine disrupting compounds. These NPnEOs have been detected in aquatic environments and are of concern. NP, NP1EO, and NP2EO were detected in water samples collected from the main watercourse and polluted tributaries of Kaoping River, Taiwan. Concentrations were below the detection limit (<LOD) to 310 μg/l for NP, from <LOD to 27.2 μg/l for NP1EO, and from <LOD to 27.5 μg/l for NP2EO. It was found that concentrations of the three compounds in a low flow period were significantly greater than in the high flow period due to the low dilution effect. The risk to aquatic organisms by NP, NP1EO, and NP2EO was expressed as hazard quotient and hazard index and simulated with the Monte Carlo method. Results from this study suggested an inadequately treated domestic wastewater caused high concentrations of NP, NP1EO, and NP2EO and a high risk to aquatic organisms. 相似文献
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Wallace BD Wang H Lane KT Scott JE Orans J Koo JS Venkatesh M Jobin C Yeh LA Mani S Redinbo MR 《Science (New York, N.Y.)》2010,330(6005):831-835
The dose-limiting side effect of the common colon cancer chemotherapeutic CPT-11 is severe diarrhea caused by symbiotic bacterial β-glucuronidases that reactivate the drug in the gut. We sought to target these enzymes without killing the commensal bacteria essential for human health. Potent bacterial β-glucuronidase inhibitors were identified by high-throughput screening and shown to have no effect on the orthologous mammalian enzyme. Crystal structures established that selectivity was based on a loop unique to bacterial β-glucuronidases. Inhibitors were highly effective against the enzyme target in living aerobic and anaerobic bacteria, but did not kill the bacteria or harm mammalian cells. Finally, oral administration of an inhibitor protected mice from CPT-11-induced toxicity. Thus, drugs may be designed to inhibit undesirable enzyme activities in essential microbial symbiotes to enhance chemotherapeutic efficacy. 相似文献
187.
ABSTRACT We have developed a new complementary model of gene interaction between diploid host and haploid pathogen by allowing for arbitrary levels of dominance in the host. This model enables us to assess the effects of overdominance, incomplete dominance, and underdominance on the equilibrium frequencies of resistance and virulence genes and on the stability of equilibria. Our model reduces to a gene-for-gene model when complete dominance of resistance is assumed. Computer simulations show that our model has two new features. First, when there is overdominance or underdominance of resistance, the internal equilibrium points exist even when there is no cost of unnecessary virulence or when there is a cost of necessary virulence at the balance between cost of unnecessary virulence and effectiveness of resistance. Second, the occurrence of stable resistance and virulence polymorphism is strongly dependent on the level of dominance. These two features suggest the need for caution when using the gene-for-gene model, especially in the presence of overdominance or underdominance. Our model is particularly suitable for studying the coevolutionary dynamics between hybrid populations and their pathogens in natural pathosystems. 相似文献
188.
A multivalent in ovo vaccine (MIV) was tested for safety and efficacy in a commercial broiler complex. The MIV comprised five replicating live viruses including serotypes 1, 2, and 3 of Marek's disease virus (MDV), an intermediate infectious bursal disease virus (IBDV) and a recombinant fowl poxvirus (FPV) vector vaccine containing HN and F genes of Newcastle disease virus (NDV). The performance of MIV-vaccinated broilers was compared with that of hatchmates that received turkey herpesvirus (HVT) alone (routinely used in ovo vaccine in the broiler complex). The chickens that hatched from the MIV-injected and HVT-injected eggs were raised under commercial conditions in six barns. Barn 1 housed 17,853 MIV-vaccinated chickens and each of the barns 2-6 housed 18,472-22,798 HVT-vaccinated chickens. The HVT-vaccinated chickens were given infectious bronchitis virus (IBV) and NDV vaccines at hatch and at 2 wk of age. The MIV-vaccinated chickens received IBV vaccine at hatch and IBV + NDV at 2 wk of age. The relative values of hatchability of eggs, livability and weight gain of chickens, and condemnation rates at processing were comparable between the MIV and the HVT groups (P > 0.05). Chickens from the MIV- and the HVT-vaccinated groups were challenged with virulent viruses under laboratory conditions. The resistance of vaccinated chickens against Marek's disease could not be assessed because of high natural resistance of unvaccinated commercial broilers to virulent MDV. The relative resistances of the MIV- and the HVT-vaccinated groups, respectively, against other virulent viruses were as follows: IBDV, 100% for both groups; NDV, 81% vs. 19%; FPV, 86% vs. 0%. The successful use of MIV under field conditions expands the usefulness of the in ovo technology for poultry. 相似文献
189.
Protective immunity against infectious bursal disease virus in chickens in the absence of virus-specific antibodies 总被引:1,自引:0,他引:1
The role of cell-mediated immunity (CMI) in pathogenesis of infectious bursal disease virus (IBDV) was investigated. One-day-old specific pathogen-free chickens were treated with 3mg of cyclophosphamide (Cy) per chicken for 4 consecutive days and, 3 weeks later, infected with the IBDV-IM strain. Chickens were examined for: (a) mitogenic response of splenocytes to ConA, as an indicator of T-cell functions in vitro, (b) antibody against IBDV by ELISA, (c) IBDV genome in various tissues by RT-PCR and (d) immunological memory. At the time of IBDV infection, Cy-treated chickens had depleted bursal tissue (an avian primary B-cell lymphoid organ), severely compromised antibody-producing ability, but normal T-cell response to ConA. In primary infection, no detectable antibody against IBDV antigen in Cy-treated, IBDV-infected chickens was observed up to 28 days post-infection (PI), while IBDV genome was detected by RT-PCR in spleen, thymus, liver and blood until 10 days PI. Like intact control chickens infected with IBDV, Cy-treated, IBDV-infected chickens suppressed splenocytes responses to ConA from 5 to 10 days PI, suggesting that intact control as well as Cy-treated chickens responded similarly to IBDV infection in the early phase. Following re-infection with IBDV, no detectable secondary antibody response to IBDV as well as IBDV genome in tissues were observed in Cy-treated chickens, while intact control chickens developed vigorous secondary antibody response. Similar to intact control chickens infected with IBDV, Cy-treated chickens after second infection with IBDV did not suppress splenocyte response to ConA. These results suggested that in the absence of detectable anti-IBDV antibodies, protection of Cy-treated chickens from IBDV infection may occur via immunological memory mediated by CMI. We concluded that under normal conditions, IBDV induces a protective antibody response, however, in the absence of antibody, CMI alone is adequate in protecting birds against virulent IBDV. 相似文献
190.