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1.
K. Ferrazzoli Devienne M.S. Gonalves Raddi R. Gomes Coelho W. Vilegas 《Phytomedicine》2005,12(5):378-381
Three naturally occurring isocoumarins (paepalantine, paepalantine 9-O-beta-D-glucopyranoside and paepalantine 9-O-beta-D-allopyranosyl(1 --> 6) glucopyranoside) and two semi-synthetic analogues, 9,10-acylated compound and 9-OH-10-methylated compound, structurally similar to paepalantine, were evaluated for antimicrobial activity using a spectrophotometric microdilution technique. The paepalantine was active against S. aureus, S. epidermidis, and E. faecalis while the other four compounds proved ineffective against all microorganisms tested at concentrations of 500 microg/ml. Variations in phenolic substitution at OH-9 and/or OH-10 in the paepalantine molecule resulted in compounds without antimicrobial activity. A combination of structural features, two phenolic groups as cathecolic system, forms an oxygenated system arrangement that may reflect the potentially antimicrobial properties of paepalantine. 相似文献
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Natan Medeiros Maciel Carlos Alberto Schwartz Guarino Rinaldi Colli Mariana Souza Castro Wagner Fontes Elisabeth N. Ferroni Schwartz 《Biochemical Systematics and Ecology》2006
This research tested the utility of two classes of skin secretion compounds to the phylogeny of the Bufo crucifer group. Skin secretions from specimens of nine populations of B. crucifer group were obtained and submitted to qualitative analysis. We observed a clear difference in the composition of the skin secretion molecules obtained from the species of Bufo studied. Fifty-nine molecules, 16 indolealkylamines and 43 proteins, were used as characters, and 39 of these were parsimonious informative. The tree topology of the skin secretion combined data showed areas of congruence and conflict when compared to an mtDNA phylogeny of the B. crucifer group. We used the Templeton test to evaluate the heterogeneity between the skin secretion and mtDNA data. Although not recommended, we performed a combined analysis with the two partitions. The skin secretion characters from the species of Bufo studied have phylogenetic signal. These data are indicative, at least as a preliminary study, of the phylogenetic relationships among the B. crucifer group taxa. 相似文献
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Fátima H. Vaz Patrícia M. Machado Rita D. Brand?o Cátia T. Laranjeira Joana S. Eugénio Aires H. Fernandes Saudade P. André 《The journal of histochemistry and cytochemistry》2007,55(11):1105-1113
Only 20-25% of families screened for BRCA1/2 mutations are found positive. Because only a positive result is informative, we studied the role of BRCA1/2 immunohistochemistry as an additional method for patient selection. From 53 high-risk-affected probands, 18 (34%) had available paraffin blocks of their tumors and were selected for this study. Mutation screening was done by conformation-sensitive gel electrophoresis and multiplex ligation-dependent probe amplification. For immunohistochemistry, 21 neoplastic specimens (15 breast carcinomas, 5 ovary neoplasms, and 1 rectal adenocarcinoma) were analyzed with BRCA1 (monoclonal antibody, Ab-1, oncogene) and BRCA2 (polyclonal antibody, Ab-2, oncogene) antibodies. Absence of the BRCA1 protein was confirmed in negative tumors by Western blotting. Seven patients were positive for BRCA1/2 mutations: 5 for BRCA1 and 2 for BRCA2. Four out of five positive patients had tumors negative for BRCA1 immunostaining, and the remaining 13 BRCA1-negative patients had positive BRCA1 immunostaining in all tumor samples. Sensitivity to predict for BRCA1 mutation carriers was 80%, and specificity was 100%, with a positive predictive value of 100% and a negative predictive value of 93%. This correlation was statistically significant (p=0.001). No correlation was observed for BRCA2. If larger studies confirm these results, high-risk patients with BRCA1-negative tumors should be screened first for this gene. 相似文献
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Leandro Neves Faria Marlon Gomes Da Rocha Quirijn De Jong Van Lier Derblai Casaroli 《Plant and Soil》2010,331(1-2):299-311
Correct modeling of root water uptake partitioning over depth is an important issue in hydrological and crop growth models. Recently a physically based model to describe root water uptake was developed at single root scale and upscaled to the root system scale considering a homogeneous distribution of roots per soil layer. Root water uptake partitioning is calculated over soil layers or compartments as a function of respective soil hydraulic conditions, specifically the soil matric flux potential, root characteristics and a root system efficiency factor to compensate for within-layer root system heterogeneities. The performance of this model was tested in an experiment performed in two-compartment split-pot lysimeters with sorghum plants. The compartments were submitted to different irrigation cycles resulting in contrasting water contents over time. The root system efficiency factor was determined to be about 0.05. Release of water from roots to soil was predicted and observed on several occasions during the experiment; however, model predictions suggested root water release to occur more often and at a higher rate than observed. This may be due to not considering internal root system resistances, thus overestimating the ease with which roots can act as conductors of water. Excluding these erroneous predictions from the dataset, statistical indices show model performance to be of good quality. 相似文献
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G A Conder L F Mayberry J R Bristol G A Castro B L Lee D D Kratzer S D Folz D L Rector 《Prostaglandins》1987,34(6):817-827
PGE1 and PGE2 have been reported to enhance natural expulsion of Nippostrongylus brasiliensis, a nematode parasite, from the intestine of the rat. Mucus production may also be a key element of worm rejection. Our study attempts to determine if 1) PGE1 or PGE2 alter the normal course of infection with N. brasiliensis in rats, 2) a known mucous enhancing drug, acetazolamide, can augment the rate of worm expulsion, and 3) combinations of prostaglandins and acetazolamide affect N. brasiliensis in the rat. Rats were inoculated with approximately 1,000 infective larvae of N. brasiliensis. Animals were administered, intraduodenally, one of the following: 0.2 ml 0.9% NaCl; 0.2 ml 100% ethanol; 250 micrograms PGE1/0.2 ml 100% ethanol; 250 micrograms PGE2/0.2 ml 100% ethanol; 250 micrograms acetazolamide/0.2 ml 100% ethanol; 250 micrograms PGE1 or PGE2 + 250 micrograms acetazolamide/0.2 ml 100% ethanol. These solutions were given in a single bolus on day 6 postinoculation (PI) or twice daily on days 6-9 PI. Following these treatments the number of parasite ova per gram feces per day for days 6-10 PI and numbers of worms present at necropsy on day 10 PI were determined. Treatment with prostaglandins or acetazolamide or both failed to adversely affect egg deposition by adult female worms or the number of worms in the small intestine. These results do not support the involvement of prostaglandins in the expulsion of N. brasiliensis from the host intestine. 相似文献