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51.
Rolim MF Riger CJ Eleutherio EC Colão Cda F Pereira GC Schanaider A 《Redox report : communications in free radical research》2007,12(6):267-274
This experimental study aimed to evaluate colon healing after portal ischemia followed by reperfusion. Seventy male Wistar rats randomly distributed in four groups were used: Group 1, colonic anastomosis (n = 20); Group 2, portal ischemia-reperfusion (n = 20); Group 3, colonic anastomosis and portal ischemia-reperfusion (n = 20); and Group 4, control (n = 10). In the postoperative period, these rats were re-allocated into subgroups and lipid peroxidation and protein oxidation plasma levels were evaluated on days 1 and 5 by thiobarbituric acid reactive substances (TBARS) and slot-blotting assays, respectively. A segment of the right colon was also removed for collagen analysis. Both malondialdehyde (MDA) and protein carbonyl levels (oxidative markers of lipids and proteins) presented a significant increase after reperfusion in Group 3 on days 1 (P < 0.002) and 5 (P < 0.0001). In this same group, an extensive inflammatory process showing decreased fibroplasia was observed, with deficiency in collagen deposition on both sides of the anastomosis edges. Taken together, these results indicate that portal congestion followed by reperfusion induces an oxidative stress, which impaired the mechanism of colon anastomotic healing. 相似文献
52.
ITS2 sequences as barcodes for identifying and analyzing spider mites (Acari: Tetranychidae) 总被引:1,自引:0,他引:1
The use of DNA barcodes, short DNA sequences from a standardized region of the genome, has recently been proposed as a tool
to facilitate species identification and discovery. Here we show that second internal transcribed spacer of nuclear ribosomal
DNA (rDNA-ITS2) barcodes effectively discriminate among 16 species of spider mites (Acari: Tetranychidae) from Israel. The
barcode sequences of each species were unambiguously distinguishable from all other species and formed distinct, nonoverlapping
monophyletic groups in the maximum-parsimony tree. Sequence divergences were generally much greater between species than within
them. Using a 0.02 (2%) threshold for species diagnosis in our data set, 14 out of 16 species recognized by morphological
criteria would be accurately identified. The only exceptions involved the low divergence, 0.011–0.015 (1.1–1.5%), between
Tetranychus urticae and Tetranychus turkestani, where speciation may have occurred only recently. Still, these species had fixed alternative rDNA-ITS2 variants, with five
diagnostic nucleotide substitutions. As a result, we tentatively conclude that rDNA-ITS2 sequence barcodes may serve as an
effective tool for the identification of spider mite species and can be applicable as a diagnostic tool for quarantine and
other pest management activities and decision-making. We predict that our work, together with similar efforts, will provide
in the future the platform for a uniform, accurate, practical and easy-to-use method of spider mite species identification. 相似文献
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55.
A D Bulgar L D Weeks Y Miao S Yang Y Xu C Guo S Markowitz N Oleinick S L Gerson L Liu 《Cell death & disease》2012,3(1):e252
Uracil DNA glycosylase (UDG) specifically removes uracil bases from DNA, and its repair activity determines the sensitivity of the cell to anticancer agents that are capable of introducing uracil into DNA. In the present study, the participation of UDG in the response to pemetrexed-induced incorporation of uracil into DNA was studied using isogenic human tumor cell lines with or without UDG (UDG+/+/UDG−/−). UDG−/− cells were very sensitive to pemetrexed. Cell killing by pemetrexed was associated with genomic uracil accumulation, stalled DNA replication, and catastrophic DNA strand breaks. By contrast, UDG+/+ cells were >10 times more resistant to pemetrexed due to the rapid removal of uracil from DNA by UDG and subsequent repair of the resultant AP sites (abasic sites) via the base excision repair (BER). The resistance to pemetrexed in UDG+/+ cells could be reversed by the addition of methoxyamine (MX), which binds to AP sites and interrupts BER pathway. Furthermore, MX-bound AP sites induced cell death was related to their cytotoxic effect of dual inactivation of UDG and topoisomerase IIα, two genes that are highly expressed in lung cancer cells in comparison with normal cells. Thus, targeting BER-based therapy exhibits more selective cytotoxicity on cancer cells through a synthetic lethal mechanism. 相似文献
56.
John Quagliarello M.D. Lars Cederqvist M.D. Bernard Steinetz Ph.D. Gerson Weiss M.D. 《Prostaglandins & other lipid mediators》1978,16(6):1003-1006
Relaxin, a peptide hormone produced only by the corpus luteum of pregnancy, can be used as a marker of luteal function in human pregnancy. Serum immunoreactive relaxin levels were measured serially in six women having second trimester abortions induced with intravaginal prostaglandin E2 (PGE2) suppositories. All patients aborted within 17 hours of the first suppository. No significant changes were detectable in serum relaxin levels in any of the patients. It is concluded that PGE2 does not interfere with the corpus luteum's ability to secrete relaxin in the second trimester of human pregnancy. 相似文献
57.
Machado PR Ampuero J Guimarães LH Villasboas L Rocha AT Schriefer A Sousa RS Talhari A Penna G Carvalho EM 《PLoS neglected tropical diseases》2010,4(12):e912
Background
Cutaneous leishmaniasis (CL) is treated with parenteral drugs for decades with decreasing rate cures. Miltefosine is an oral medication with anti-leishmania activity and may increase the cure rates and improve compliance.Methodology/Principal Findings
This study is a randomized, open-label, controlled clinical trial aimed to evaluate the efficacy and safety of miltefosine versus pentavalent antimony (Sbv) in the treatment of patients with CL caused by Leishmania braziliensis in Bahia, Brazil. A total of 90 patients were enrolled in the trial; 60 were assigned to receive miltefosine and 30 to receive Sbv. Six months after treatment, in the intention-to-treat analyses, the definitive cure rate was 53.3% in the Sbv group and 75% in the miltefosine group (difference of 21.7%, 95% CI 0.08% to 42.7%, p = 0.04). Miltefosine was more effective than Sbv in the age group of 13–65 years-old compared to 2–12 years-old group (78.9% versus 45% p = 0.02; 68.2% versus 70% p = 1.0, respectively). The incidence of adverse events was similar in the Sbv and miltefosine groups (76.7% vs. 78.3%). Vomiting (41.7%), nausea (40%), and abdominal pain (23.3%) were significantly more frequent in the miltefosine group while arthralgias (20.7%), mialgias (20.7%) and fever (23.3%) were significantly more frequent in the Sbv group.Conclusions
This study demonstrates that miltefosine therapy is more effective than standard Sbv and safe for the treatment of CL caused by Leishmania braziliensis in Bahia, Brazil.Trial Registration
Clinicaltrials.gov Identifier NCT00600548相似文献58.
Bernd Schneider Jonathan Gershenzon Gerson Graser Dirk Hölscher Bettina Schmitt 《Phytochemistry Reviews》2003,2(1-2):31-43
For several decades isotope labelling techniques have been the indispensable tools used to unravel pathways of secondary product biosynthesis. NMR spectroscopy, together with mass spectrometry, is the most effective measuring technique used in the analysis of metabolites enriched with stable isotopes. 2H and 13C are the NMR-detectable nuclides which have been most frequently employed in plant secondary metabolite synthesis. Examples from the biosynthesis of phenylpropanoids, phenylphenalenones, and glucosinolates are used when discussing some aspects of one-dimensional NMR analysis of metabolites selectively labelled with 2H and 13C. Besides direct NMR detection of 13C-enriched metabolites, special emphasis is placed on indirect detection of 13C and 2H, especially by HPLC-1H NMR coupling, to analyse the isotopomer pattern of compounds in low concentration. The examples discussed in this paper were obtained from studies with Anigozanthos preissii (root cultures) (Haemodoraceae) and Eruca sativa (Brassicaceae). 相似文献
59.
G.E. Kisby A. Olivas T. Park M. Churchwell D. Doerge L.D. Samson S.L. Gerson M.S. Turker 《DNA Repair》2009,8(3):400-412
Neurons of the developing brain are especially vulnerable to environmental agents that damage DNA (i.e., genotoxicants), but the mechanism is poorly understood. The focus of the present study is to demonstrate that DNA damage plays a key role in disrupting neurodevelopment. To examine this hypothesis, we compared the cytotoxic and DNA damaging properties of the methylating agents methylazoxymethanol (MAM) and dimethyl sulfate (DMS) and the mono- and bifunctional alkylating agents chloroethylamine (CEA) and nitrogen mustard (HN2), in granule cell neurons derived from the cerebellum of neonatal wild type mice and three transgenic DNA repair strains. Wild type cerebellar neurons were significantly more sensitive to the alkylating agents DMS and HN2 than neuronal cultures treated with MAM or the half-mustard CEA. Parallel studies with neuronal cultures from mice deficient in alkylguanine DNA glycosylase (Aag?/?) or O6-methylguanine methyltransferase (Mgmt?/?), revealed significant differences in the sensitivity of neurons to all four genotoxicants. Mgmt?/? neurons were more sensitive to MAM and HN2 than the other genotoxicants and wild type neurons treated with either alkylating agent. In contrast, Aag?/? neurons were for the most part significantly less sensitive than wild type or Mgmt?/? neurons to MAM and HN2. Aag?/? neurons were also significantly less sensitive than wild type neurons treated with either DMS or CEA. Granule cell development and motor function were also more severely disturbed by MAM and HN2 in Mgmt?/? mice than in comparably treated wild type mice. In contrast, cerebellar development and motor function were well preserved in MAM-treated Aag?/? or MGMT-overexpressing (MgmtTg+) mice, even as compared with wild type mice suggesting that AAG protein increases MAM toxicity, whereas MGMT protein decreases toxicity. Surprisingly, neuronal development and motor function were severely disturbed in MgmtTg+ mice treated with HN2. Collectively, these in vitro and in vivo studies demonstrate that the type of DNA lesion and the efficiency of DNA repair are two important factors that determine the vulnerability of the developing brain to long-term injury by a genotoxicant. 相似文献
60.
The prescribing of psychoactive drugs for 1431 chronically ill elderly patients being assessed for long-term institutional or community care was surveyed. Psychoactive drugs had been prescribed for about one quarter of the patients; benzodiazepines were the most frequently prescribed group. Judging from the extensive prescribing of flurazepam and chloral hydrate, commonly used hypnotics, the main reason psychoactive drugs were prescribed was to provide night-time sedation. Antidepressants and drugs promoted as useful in improving cognitive function were infrequently prescribed. Commendable prescribing practices included the infrequent use of "cerebral vasodilators" and barbiturates. Questionable prescribing practices included the infrequent use of tricyclic antidepressants in severely depressed patients and the use of tranquilizers in patients described by their attending physician as markedly or extremely withdrawn. 相似文献