首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
3.
4.
It was found in the present study that combined use of fusidic acid (FA) and berberine chloride (BBR) offered an in vitro synergistic action against 7 of the 30 clinical methicillin-resistant Staphylococcus aureus (MRSA) strains, with a fractional inhibitory concentration (FIC) index ranging from 0.5 to 0.19. This synergistic effect was most pronounced on MRSA 4806, an FA-resistant isolate, with a minimum inhibitory concentration (MIC) value of 1,024 μg/ml. The time-kill curve experiment showed that FA plus BBR yielded a 4.2 log10 c.f.u./ml reduction in the number of MRSA 4806 bacteria after 24-h incubation as compared with BBR alone. Viable count analysis showed that FA plus BBR produced a 3.0 log10 c.f.u./ml decrease in biofilm formation and a 1.5 log10 c.f.u./ml decrease in mature biofilm in viable cell density as compared with BBR alone. In addition, phase contrast micrographs confirmed that biofilm formation was significantly inhibited and mature biofilm was obviously destructed when FA was used in combination with BBR. These results provide evidence that combined use of FA and BBR may prove to be a promising clinical therapeutic strategy against MRSA.  相似文献   

5.
6.
The potential role of parameters in the reduction of hexavalent chromium [Cr(VI)] by Pseudomonas aeruginosa is not well documented. In this study, laboratory batch studies were conducted to assess the effect of a variety of factors, e.g., carbon sources, salinity, initial Cr(VI) concentrations, co-existing ions and a metabolic inhibitor, on microbial Cr(VI) reduction to Cr(III) by P. aeruginosa AB93066. Strain AB93066 tolerated up to 400 mg/L of Cr(VI) in nutrient broth medium compared to only 150 mg/L of Cr(VI) in nutrient agar. This bacteria exhibited different levels of resistance against Pb(II) (200 mg/L), Cd(II) (100 mg/L), Ni(II) (100 mg/L), Cu(II) (100 mg/L), Co(II) (50 mg/L) and Hg(II) (5 mg/L). Cr(VI) reduction was significantly promoted by the addition of glucose and glycerine but was strongly inhibited by the presence of methanol and phenol. The rate of Cr(VI) reduction increased with increasing concentrations of Cr(VI) and then decreased at higher concentrations. The presence of Ni(II) stimulated Cr(VI) reduction, while Pb(II), Co(II) and Cd(II) had adverse impact on reduction ability of this strain. Cr(VI) reduction was also inhibited by high levels of NaCl, various concentrations of sodium azide and 20 mM of SO4 2?, MoO4 2?, NO3 ?, PO4 3?. No significant relationship was observed between Cr(VI) reduction and redox potential of the culture medium. Scanning electron microscopy showed visible morphological changes in the cells due to chromate stress. Fourier transform infrared spectroscopy analysis revealed chromium species was likely to form complexes with certain functional groups such as carboxyl and amino groups on the surface of P. aeruginosa AB93066. Overall, above results are beneficial to the bioremediation of chromate-polluted industrial wastewaters.  相似文献   

7.
47 names and combinations are published as new, chiefly from the elaboration ofAlchemilla byA. Plocek inL. Bertová (ed.), Flóra Slovenska 4/3, Bratislava (in press). The populations recognized as varieties and species new to science (12 and 29, respectively) come from the summits of W. Beskids (9 taxa), Belianske Tatry (12), other parts of Tatra (8), Fatra (5), elsewhere in the Central Carpathians in Slovakia (4), the Low Beskids in E. Slovakia (1), W. and E. Carpathians (1), N. Moravia (1). In addition, three epithets are published in a new combination, and the names for two new subseries and a new forma are proposed.  相似文献   

8.
The receptor for advanced glycation end-products (RAGE), a multiligand receptor of the immunoglobulin superfamily, takes part in various inflammatory processes. The role of this receptor in the context of intercellular communication, like nanotube (NT)-mediated interaction, is largely unknown. Here, we use cell cultures of human and murine peritoneal mesothelial cells as well as murine kidneys from wild-type and RAGE knockout mouse models to assess the role of RAGE in NT formation and function. We show that loss of RAGE function results in reduced NT numbers under physiological conditions and demonstrate the involvement of MAP kinase signaling in NT formation. Additionally, we show for the first time the existence of NTs in murine kidney tissue and confirm the correlation of RAGE expression and NT numbers. Under elevated oxidative stress conditions like renal ischemia or peritoneal dialysis, we demonstrate that RAGE absence does not prevent NT formation. Rather, increased NT numbers and attenuated kidney tissue damage could be observed, indicating that, depending on the predominant conditions, RAGE affects NT formation with implications for cellular communication.  相似文献   

9.
Twenty varieties of maize (Zea mays, Poaceae) were studied through 11 attributes in three to seven randomly selected plants of each variety with a view to understanding the effect of cob characters on technologically desirable grain qualities. Canonical discriminant analysis showed thatproductivity (determined by total grain weight/cob, cob diameter and average grain weight) was the most discriminating among varieties followed by round grains fraction (represented by whole top and middle flat grains, number of rows and grain count/surface area), middle flat grains (composed of middle flat grains and grain count/surface area) and shape of the cob (determined by shape index, total grain weight/cob and cob diameter), which accounted for 35.1, 18.3, 12.2, and 9.8% of the total variance, respectively. In the light of these results, tentative norms have been suggested to evolve maize varieties of superior technological properties and yet retain high productivity. A cylindrical cob of large diameter with highest number of grains/area and smallest possible number of rows together constituted an ideal combination to achieve the objectives. Such possibilities in the light of available information are discussed.  相似文献   

10.
In situ hybridization was used to identify the sites of rDNA in the chromosome complement of the chimpanzee (Pan troglodytes). The rDNA was present in the satellite regions of chimpanzee chromosomes 14, 15, 17, 22 and 23. Four of these (14, 15, 22, 23) are homologous to human chromosomes carrying rDNA: 13, 14, 21 and 22.  相似文献   

11.
The intracellular levels of ppGpp and pppApp in various microorganisms were determined by radioimmunoassay, with was of more accuracy and convenience than previous 32P-labeling method. ppGpp was detected in bacteria, actinomycetes, yeasts and fungi. pppApp was found in non-spore forming bacteria such as the genera Pseudomonas and Escherichia, fungi and actinomycetes, but not in yeasts. In conclusion, ppGpp and pppApp are present in various prokaryotes and lower eukaryotes.  相似文献   

12.
The prevalence of osteoporosis in older patients with chronic obstructive pulmonary disease (COPD) is higher than in the age-matched elderly patients, but the exact cause in relation to COPD is not clear. We hypothesized that the underlying causes for this difference are related to bone metabolism with the possible risk factors that include the duration of COPD, GOLD grade, cor pulmonale, the frequencies of acute exacerbations within the past year, smoking and inhaled corticosteroid therapy. We conducted a matched-pair study of 100 patients aged older than 65 years at the Southwest Hospital from May to November 2012. The enrolled patients with COPD were matched to controls for age and gender. Clinical characteristics of cohorts were recorded. Bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry and osteoporosis was diagnosed according to the definition of WHO. All cohorts accepted bone metabolism marker measurement, including Procollagen type 1 aminoterminal propeptide (P1NP), β-C-telopeptides of type I collagen (βCTX), and N-terminal midmolecule fragment osteocalcin (N-MID OC). Statistical analysis was calculated using the student’s t test, ANOVA and multiple regression analysis at a significance level set at a p < 0.05. Circulating biochemical markers of bone formation (P1NP), resorption (βCTX) and turnover (N-MID OC) were significantly lower in the COPD group than control group, while mean 25-OH Vitamin D was similar in two groups. The P1NP, βCTX, and N-MID OC were still lower in men with COPD, but only P1NP was lower in women with COPD compared to that of controls. Multiple regression analysis in COPD group suggests that age, the frequency of acute exacerbation, and BMD are independent risk factors for P1NP. The frequency of acute exacerbation within the past one year and 25-OH D level are independent risk factors for βCTX; the frequency of acute exacerbation is the only independent risk factor for N-MID OC. These were significant differences in bone metabolism in patients with or without COPD. These results should help us to further understand the cause of osteoporosis and fractures and conduce to prevent osteoporosis in patients with COPD.  相似文献   

13.
To increase electrochemotherapy (ECT) applicability, the effectiveness of new drugs is being tested in combination with electroporation. Among them two ruthenium(III) compounds, (imH)[trans-RuCl4(im)(DMSO-S)] (NAMI-A) and Na[trans-RuCl4(ind)2] (KP1339), proved to possess increased antitumor effectiveness when combined with electroporation. The objective of our experimental work was to determine influence of electroporation on the cytotoxic and antitumor effect of a ruthenium(III) compound with hampered transmembrane transport, (imH)[trans-RuCl4(im)2] (KP418) in vitro and in vivo and to determine changes in metastatic potential of cells after ECT with KP418 in vitro. In addition, platinum compound cisplatin (CDDP) and ruthenium(III) compound NAMI-A were included in the experiments as reference compounds. Our results show that electroporation leads to increased cellular accumulation and cytotoxicity of KP418 in murine melanoma cell lines with low and high metastatic potential, B16-F1 and B16-F10, but not in murine fibrosarcoma cell line SA-1 in vitro which is probably due to variable effectiveness of ECT in different cell lines and tumors. Electroporation does not potentiate the cytotoxicity of KP418 as prominently as the cytotoxicity of CDDP. We also showed that the metastatic potential of cells which survived ECT with KP418 or NAMI-A does not change in vitro: resistance to detachment, invasiveness, and re-adhesion of cells after ECT is not affected. Experiments in murine tumor models B16-F1 and SA-1 showed that ECT with KP418 does not have any antitumor effect while ECT with CDDP induces significant dose-dependent tumor growth delay in the two tumor models used in vivo.  相似文献   

14.
Vitamin D appears to have an important role in the modulation of the central nervous system. Vitamin D exerts its biological effects through its interaction with the vitamin D receptor (VDR). Located on chromosome 12 (12q13.1), the VDR gene has many different polymorphisms. Some of them are known to affect the VDR function, such as FokI (rs2228570, T/C) single nucleotide polymorphism. We aimed to explore a potential relationship between FokI VDR polymorphism and impulsiveness in alcohol-dependent (AD) patients. The study population consisted of 148 patients diagnosed with alcohol dependence (DSM-IV criteria) and 212 healthy controls. DNA was extracted from whole blood samples using the standard procedure. Genotypes were analyzed using a real-time PCR method. We found that FokI VDR gene polymorphism was associated with impulsivity [Barratt Impulsiveness Scale (BIS)-11 total score; P = 0.014], and with attentional impulsivity (BIS-11 subscale; P = 0.002) in the male AD patients. Our results suggest that CC FokI genotype of the VDR gene is associated with a higher level of impulsivity in these patients. This finding supports the hypothesis that impulsiveness, which significantly contributes to development of alcohol dependence, has a genetic background.  相似文献   

15.
This study was conducted to reveal genetic diversity among 23 local apple genotypes using nuclear (RAPD) and chloroplast DNA (PCR-cpRFLP) markers. Eleven RAPD primers and four cpDNA primer combinations were used in this study. RAPD primers produced a total of 77 polymorphic fragments with an average of seven bands per primer. The percentage of polymorphic bands (68.14 %) showed the efficiency of used RAPD primers in distinguishing all the genotypes considered. Genetic similarity between studied genotypes varied from 0.38 to 0.72 and cluster analysis showed the abundant diversity, indicating high intraspecific genetic variation between Iranian apple genotypes. From the four universal chloroplast primer pairs, three primer pairs amplified the fragments and their combinations showed polymorphic patterns and revealed intraspecific chloroplast variation. The information will facilitate germplasm identification, conservation and new cultivar development.  相似文献   

16.
The mahseers are an important group of fishes endemic to Asia with most species considered threatened. Conservation plans to save declining wild populations are hindered by unstable taxonomy, and detailed systematic review could form a solid platform for future management and conservation. D-loop and cytochrome c oxidase I (COI) mtDNA sequences were examined in nine mahseer species of Tor, Neolissochilus, and Naziritor. Pseudogenes amplified in a portion of the species limited the utility of the D-loop region. ABGD analysis, NJ, ML, and MP methods and genetic distance (TrN?+?I?+?G) using COI data revealed concordant species delimiting patterns. The three genera were monophyletic, separated as distinct clades (TrN?+?I?+?G 0.064 to 0.106), and Naziritor was flagged as a separate genus, distinct from Puntius (TrN?+?I?+?G 0.196). Out of seven nominal species known for Tor cogeners from India, only five were recovered with mtDNA data (TrN?+?I?+?G 0.000 to 0.037) and two species could not be distinguished with the molecular data set employed. Tor mosal, synonymized as Tor putitora, was rediscovered as a distinct species (TrN?+?I?+?G 0.031) based on its type locality. Tor mussulah was confirmed as a separate species (TrN?+?I?+?G 0.019 to 0.026). Two valid species, Tor macrolepis and T. mosal mahanadicus, were not distinct from T. putitora (TrN?+?I?+?G 0.00). The high divergence with mtDNA data failed to validate T. mosal mahanadicus as a subspecies of T. mosal (TrN?+?I?+?G 0.031). Morphological outliers discovered within the distribution range of Tor tor (TrN?+?I?+?G 0.022 to 0.025) shared the same lineage with T. putitora (TrN?+?I?+?G 0.002 to 0.005), indicating a new extended distribution of the Himalayan mahseer T. putitora in the rivers of the Indian central plateau. The findings indicate the need for integrating molecular and morphological tools for taxonomic revision of the Tor and Naziritor genera, so that taxa are precisely defined for accurate in situ and ex situ conservation decisions.  相似文献   

17.
Four suppression subtractive hybridization (SSH) cDNA libraries were constructed to identify differentially expressed salinity stress responsive genes of black tiger shrimp, Penaeus monodon exposed to high (55 ppt) salinity conditions. One each of the forward and reverse SSH cDNA libraries were developed from the gill and gut tissues of shrimp and clones having inserts larger than 300 bp were unidirectionally sequenced. Based on the sequence homology search, the identified genes were categorized for their putative functions related to a wide range of biological roles, such as nucleic acid regulation and replication, immune response, energy and metabolism, signal transduction, cellular process, structural and membrane proteins, stress and osmoregulation. Gene expression levels in response to high salinity conditions at 2 weeks post salinity stress for some of the differentially expressed genes (Na+/K+-ATPase α-subunit, glutathione peroxidase, intracellular fatty acid binding protein, elongation factor 2, 14-3-3 like protein, penaeidin, translationally controlled tumor protein, transglutaminase and serine proteinase inhibitor B3) identified from SSH cDNA libraries were analysed by real-time RT-PCR. The highest gene expression levels was observed for Na+/K+-ATPase α-subunit in gill tissues (15.23-folds) and antennal glands (12.01-folds) and intracellular fatty acid binding protein in gut tissues (14.05-folds) respectively. The differential and significant levels of gene expression indicate the functional role of these genes in shrimp salinity stress adaptive mechanisms.  相似文献   

18.
19.
Senescence is associated with hormonal imbalance and prostatic disorders. Angiogenesis is fundamental for the progression of malignant lesions and is a promising target for prostate cancer treatment. The aim was to characterize matrix metalloproteinase-9 (MMP-9) and insulin-like growth factor receptor-1 (IGFR-1) responses in the prostate during senescence and following antiangiogenic and/or androgen ablation therapies, comparing them to cancer progression features in TRAMP mice. Aged male mice (52-week-old FVB) were submitted to antiangiogenic treatments with SU5416 (6 mg/kg; i.p.) and/or TNP-470 (15 mg/kg; s.c). Finasteride (20 mg/kg; s.c.) was administered alone or associated to both inhibitors. Dorsolateral prostate was collected for light microscopy, and immunohistochemistry and Western blotting collected for MMP-9 and IGFR-1. Senescence led to inflammation and different proliferative lesions in the prostate, as well as to increased MMP-9 and IGFR-1, resembling TRAMP mice prostatic microenvironment. Antiangiogenic therapies promoted recovery and/or interruption of age-associated alterations, presenting differential effects on the molecules studied. SU5416 acted mainly on MMP-9, whereas TNP-470 showed its best influence on IGFR-1 levels. Finasteride administration, alone or in combination with antiangiogenic agents, also resulted in regression of inflammation and neoplastic lesions, besides having a negative modulatory effect on both MMP-9 and IGFR-1. We concluded that stimulated tissue remodeling and proliferative processes during senescence predisposed the prostate to malignant disorders. The combination of different agents was more effective to minimize prostatic imbalance during this period, probably due to the differential action of each drug on factors involved in cell proliferation and extracellular matrix remodeling, resulting in a broader spectrum of effects following the combined treatment.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号