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排序方式: 共有146条查询结果,搜索用时 31 毫秒
1.
Iron(III)-adriamycin and Iron(III)-daunorubicin complexes: physicochemical characteristics, interaction with DNA, and antitumor activity 总被引:1,自引:0,他引:1
Fe(III) complexes of two anthracyclines, adriamycin and daunorubicin, have been studied. Using potentiometric and spectroscopic measurements, we have shown that adriamycin and daunorubicin form two well-defined species with Fe(III), which can be formulated as respectively Fe(HAd)3 and Fe(HDr)3. In these formulas, HAd and HDr stand for adriamycin and daunorubicin in which the 1,4-dihydroxy-anthraquinone moiety is half-deprotonated. Both complexes are six-membered chelates. The stability constant is beta = (2.5 +/- 0.5) X 10(28) for both complexes. Interaction with DNA has been studied showing that, despite strong coordination to Fe(III), anthracyclines are able to intercalate between DNA bases pairs, releasing the metal. These complexes display antitumor activity against P 388 leukemia that compares with that of the free drug. Fe(HAd)3, unlike adriamycin, does not catalyze the flow of electrons from NADH to molecular oxygen through NADH dehydrogenase. Moreover, it is shown that the triferric adriamycin compound so called "quelamycin" is in fact a mixture of Fe(HAd)3 and polymeric ferric hydroxide. 相似文献
2.
C L Lavelle 《American journal of physical anthropology》1977,46(3):415-421
Sixteen dimensions were measured from the maxillary and mandibular dental arches of different ethnic groups of man, apes and monkeys. Multivariate analysis showed that discrimination was possible among the ethnic groups of man on the one hand and between the ape and monkey samples on the other. Nevertheless, the actual degree of discrimination between the primate samples depended upon whether the maxillary or mandibular arch dimensions were analysed. Furthermore, subsequent inclusion of the dental arch dimensions of fossil hominoid samples into the analysis confirmed the taxonomic significance of the dental arch, although its importance must await the acquisition of the more non-human primate data. 相似文献
3.
Christopher L. B. Lavelle 《American journal of physical anthropology》1977,46(3):423-425
Canonical correlations between tooth and long bone dimensions showed a greater correlation for Anglo-Saxons and apes than for Nineteenth Century Londoners, i.e., coefficients of 0.75 for gorilla, 0.72 for chimpanzee, 0.69 for orang-utans, 0.74 for Anglo-Saxons, but 0.53 for Nineteenth Century Londoners. Although based upon limited sample sizes and limited metrical profiles of teeth and long bones, the data support the thesis that modern Europeans are under reduced selection pressure to maintain tooth size compared with apes or ancient man. 相似文献
4.
The involvement of the bridging imidazolate in the catalytic mechanism of action of bovine superoxide dismutase. 总被引:2,自引:2,他引:0 下载免费PDF全文
M E McAdam E M Feilden F Lavelle L Calabrese D Cocco G Rotilio 《The Biochemical journal》1977,167(1):271-274
The pulse-radiolysis method has been used to study the catalytic mechanism of O2 leads to dismutation by the Co(II)-substituted bovine erythrocuprein (superoxide dismutase, EC 1.15.1.1). Catalysis is accompanied by spectral changes that may be interpreted in terms of rapid protonation and deprotonation of the Cu-facing nitrogen atom of the imidazolate that bridges the Cu(II) and the Co(II) [or Zn(II)] in the oxidized enzyme. This rapid change permits the possibility that the imidazole is a proton donor in the catalytic reduction of O2 leads to. 相似文献
5.
6.
Robert Vince Mel Hua Jay Brownell George C. Lavelle Jeanine Qualls William M. Shannon 《Nucleosides, nucleotides & nucleic acids》2013,32(5-6):1127-1128
Abstract Carbocyclic 2′, 3′-didehydro-2′,3′-dideoxyquanosine (carbovir), a novel nucleoside analog, emerged as a potent and selective anti-HIV agent from a primary screen of a large number of carbocyclic nucleosides.1 Carbovir inhibited the infectivity and replication of HIV in T-cells at concentrations 200 to 400-fold below toxicity to host cells. Carbovir was also evaluated for its Inhibitory effects on the expression of viral antigen in HIV-infected CEM cells. Production of p 24 core antigen at optimal inhibitory concentrations of the antiviral agents indicated comparable results for AZT, ddA and carbovir. 相似文献
7.
Pádraig J. Ross Caroline E. Sutton Sarah Higgins Aideen C. Allen Kevin Walsh Alicja Misiak Ed C. Lavelle Rachel M. McLoughlin Kingston H. G. Mills 《PLoS pathogens》2013,9(4)
Whooping cough caused by Bordetella pertussis is a re-emerging infectious disease despite the introduction of safer acellular pertussis vaccines (Pa). One explanation for this is that Pa are less protective than the more reactogenic whole cell pertussis vaccines (Pw) that they replaced. Although Pa induce potent antibody responses, and protection has been found to be associated with high concentrations of circulating IgG against vaccine antigens, it has not been firmly established that host protection induced with this vaccine is mediated solely by humoral immunity. The aim of this study was to examine the relative contribution of Th1 and Th17 cells in host immunity to infection with B. pertussis and in immunity induced by immunization with Pw and Pa and to use this information to help rationally design a more effective Pa. Our findings demonstrate that Th1 and Th17 both function in protective immunity induced by infection with B. pertussis or immunization with Pw. In contrast, a current licensed Pa, administered with alum as the adjuvant, induced Th2 and Th17 cells, but weak Th1 responses. We found that IL-1 signalling played a central role in protective immunity induced with alum-adsorbed Pa and this was associated with the induction of Th17 cells. Pa generated strong antibody and Th2 responses, but was fully protective in IL-4-defective mice, suggesting that Th2 cells were dispensable. In contrast, Pa failed to confer protective immunity in IL-17A-defective mice. Bacterial clearance mediated by Pa-induced Th17 cells was associated with cell recruitment to the lungs after challenge. Finally, protective immunity induced by an experimental Pa could be enhanced by substituting alum with a TLR agonist that induces Th1 cells. Our findings demonstrate that alum promotes protective immunity through IL-1β-induced IL-17A production, but also reveal that optimum protection against B. pertussis requires induction of Th1, but not Th2 cells. 相似文献
8.
Potent and selective activity of a new carbocyclic nucleoside analog (carbovir: NSC 614846) against human immunodeficiency virus in vitro 总被引:8,自引:0,他引:8
R Vince M Hua J Brownell S Daluge F C Lee W M Shannon G C Lavelle J Qualls O S Weislow R Kiser 《Biochemical and biophysical research communications》1988,156(2):1046-1053
Carbocyclic 2',3'-didehydro-2',3'-dideoxyguanosine (Carbovir: NSC 614846), a novel nucleoside analog, emerged as a potent and selective anti-HIV agent from a large screening program conducted by the National Cancer Institute and its contractors. Its hydrolytic stability and its ability to inhibit the infectivity and replication of HIV in T-cells at concentrations of approximately 200- to 400-fold below toxic concentrations make carbovir a top-priority candidate for development as a potential antiretroviral agent in the treatment of AIDS patients. 相似文献
9.
Newer agents and procedures give urologists more options in treating patients who have urinary incontinence related to such etiologies as an ineffective sphincter, detrusor hypersensitivity, obstruction, or a combination of these. Abolition of the involuntary contractions characteristic of detrusor instability can be accomplished pharmacologically or surgically. First-line anticholinergic agents are tolterodine and oxybutynin XL, given orally. Alternatively, intravesical administration provides a high concentration of drug, such as capsaicin or resiniferatoxin, at the detrusor muscle level. However, this commits the patient to intermittent self-catheterization. Surgery is reserved for those who have failed prolonged trials of conservative therapies. For patients with intractable urge incontinence, urologists have the new technique of sacral nerve stimulation. 相似文献
10.
Lavelle P Blouin M Boyer J Cadet P Laffray D Pham-Thi AT Reversat G Settle W Zuily Y 《Comptes rendus biologies》2004,327(7):629-638
The use of pesticides to control plant parasites and diseases has generated serious problems of public health and environmental quality, leading to the promotion of alternative Integrated Pest Management strategies that tend to rely more on natural processes and the active participation of farmers as observers and experimenters in their own fields. We present three case studies that point at different options provided by locally available populations of soil organisms, the maintenance of diverse populations of pests or increased resistance of plants to pest attacks by their interactions with earthworms and other useful soil organisms. These examples demonstrate the diversity of options offered by the non-planned agro-ecosystem diversity in pest control and the need to identify management options that maintain this biodiversity. 相似文献