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Several studies demonstrated that in insects cuticle melanism is interrelated with pathogen resistance, as melanin‐based coloration and innate immunity possess similar physiological pathways. For some insects, higher pathogen resistance was observed in darker individuals than in individuals with lighter cuticular coloration. Here, we investigated the difference in immune response between two color morphs (black and red) and between the life stages (pupa and adult) of the red palm weevil Rhynchophorus ferrugineus (Coleoptera: Curculionidae). Here in this study, cuticle thickness, microbial test (antimicrobial activity, phenoloxidase activity, and hemocyte density), and immune‐related gene expression were evaluated at different stages of RPW. Study results revealed that cuticle thickness of black phenotype was thicker than red phenotype at old‐pupa stage, while no significant difference found at adult stage. These results may relate to the development processes of epidermis in different stages of RPW. The results of antimicrobial activity, phenoloxidase (PO) activity, and hemocyte density analyses showed that adults with a red phenotype had stronger pathogen resistance than those with a black phenotype. In addition to antimicrobial activity and PO activity, we tested relative gene expression in the fat body of old pupae. The results of hemolymph antimicrobial analysis showed that old pupae with a red phenotype were significantly different from those with a black phenotype at 12 hr after Staphylococcus aureus injection, suggesting that red phenotype pupae were more sensitive to S. aureus. Examination of gene expression in the fat body also revealed that the red phenotype had a higher immune response than the black phenotype. Our results were inconsistent with the previous conclusion that dark insects had increased immune function, suggesting that the relationship between cuticle pigmentation and immune function in insects was not a direct link. Additional possible factors that are associated with the immune response, such as life‐history, developmental, physiological factors also need to be considered. 相似文献
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The inhibition of human prostatic 5 alpha-reductase by androstenedione (A), 4-hydroxyandrostenedione (4-OH-A), and 4-methoxyandrostenedione (4-MeO-A) was studied. All three steroids inhibited 5 alpha-reductase in a concentration-dependent manner. The inhibition was competitive with respect to testosterone and non-competitive with respect to NADPH, indicating that these compounds inhibit 5 alpha-reductase by acting as alternative substrates. Ki values obtained were in the range 0.21-0.3 microM (A), 1.01-2.04 microM (4-OH-A), and 10.2-28.3 microM (4-MeO-A). Thus the two derivatives of androstenedione are poor inhibitors of 5 alpha-reductase and appear to have limited clinical potential. 相似文献
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Daniela Garcia Ribeiro Ana Cláudia Pavarina Eunice Teresinha Giampaolo Ana Lucia Machado Janaina Habib Jorge Patrícia Petromilli Nordi Sasso Garcia 《Gerodontology》2009,26(2):150-156
Objectives: The purpose of this study was to determine the effect of two different preventive oral hygiene education and motivation programmes on the plaque and gingival index, as well as denture hygiene of patients provided with removable partial denture (RPD) during a 12‐month follow‐up. Material and methods: A total of 53 partially edentulous patients were recruited for this study. The presence or absence of plaque and gingival bleeding by gentle probing was scored on all tooth surfaces at the preliminary visit. The plaque and gingival indexes were measured using the Löe index. Following treatment, the patients were randomly divided into three groups. In Control Group I, subjects were instructed to continue their personal oral hygiene routine. In Group II, participants were given verbal instructions and a self‐educational manual on oral hygiene without illustrations. In Group III, oral hygiene guidance was delivered using a combination of verbal instructions and a self‐teaching manual. To evaluate the effect of the different modes of instruction, the presence or absence of plaque and gingival bleeding was scored on all tooth surfaces (day zero examination) and re‐examined 7, 15 and 30 days, 3, 6 and 12 months following RPD placement. The state of denture hygiene was evaluated 7, 15 and 30 days and 3, 6 and 12 months following rehabilitation. Parametric statistics was applied to dental plaque and gingival indexes. For accumulation of plaque and calculus on the RPD, non‐parametric statistic was applied. Results: The frequency of plaque found during the preliminary visit was higher than that found in the other periods. With regard to gingival index, significant difference was found between the preliminary visit examination and other periods. There was a significant difference in the plaque accumulation on the denture surface between groups I and III. Conclusion: The different methods of oral hygiene instruction used in this study indicate that the type of education was not of significant importance. 相似文献
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In their attempts to evade the host immune response, mammalian viruses have evolved a wide range of strategies. These include the expression and modification of various host cytokines and receptors. Understanding the mechanism of action of these virally encoded proteins will clearly deepen our insights into immunology. In the past few months several new virally encoded chemokines have been described which can modify both the host immune and antiviral response. Their manipulation of the cytokine structure-function relationship may also be useful in the development of reagents for treating immune and proliferative diseases. 相似文献
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Plasmonics - This paper presents a canonical boundary value problem to understand the behavior of electromagnetic surface waves propagated on the planar interface of rugate filter and hyperbolic... 相似文献
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Treatment with cannabis induces a partial inactivation of the spindle apparatus, and an unequal separation of the chromosomes.
There is more or less a tendency to с-mitosis at higher concentrations and to multipolar anaphases at lower concentrations
like so many other narcotic substances. The MI value decreases linearly and sharply with the increase of concentrations used,i.e. cannabis had a severe mitodepressive effect. Long treatment for 24 h caused the death of all colls examined.
Cannabis causes a complete dissolution of the matrix substance of the chromosomes and breaks down the chromatin material of
the nucleus to minute granules. This phenomenon was observed in all root tips treated with the cannabis. The same picture
was observed after letting the roots recover in water. 相似文献
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