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11.
B Utete C Phiri SS Mlambo N Maringapasi N Muboko TB Fregene 《African Journal of Aquatic Science》2018,43(1):1-15
Concentrations of aluminium, cadmium, chromium, cobalt, copper, iron, lead, nickel and zinc were determined in surface water, benthic sediments, and the gills, liver and stomach muscle tissues of Oreochromis niloticus and Clarias gariepinus in peri-urban lakes Chivero and Manyame, Zimbabwe. Five sites were sampled in each lake once per month in November 2015, February, May, August and November 2016. Pollution load index detected no metal contamination, whereas the geo-accumulation index reflected heavy to extreme sediment pollution, with Fe, Cd, Zn, Cr, Ni and Cu present in both lakes. Significant spatial temporal variations were detected for Al, Cr, Cu and Pb across sites within and between the two lakes. High Fe, Al and Cr concentrations in water and sediments in lakes Chivero and Manyame derive from geogenic background sources in addition to anthropogenic loads and intensity. Elevated concentrations of Al, Pb, Cu, Cd, Fe and Zn detected in gills, liver and stomach tissue of catfish corroborate concentrations in water and sediments, and pose the highest ecological and health risk for hydrobionts in lakes Chivero and Manyame. Contiguity of peri-urban lakes exposes them to similar threats, necessitating creative water management strategies, which ensure ecological continuity. 相似文献
12.
Cathy Zhou Zilong Yuan Weijie Ma Lihong Qi Angelique Mahavongtrakul Ying Li Hong Li Jay Gong Reggie R. Fan Jin Li Michael Molmen Travis A. Clark Dean Pavlick Garrett M. Frampton Brady Forcier Elizabeth H. Moore David K. Shelton Matthew Cooke Siraj M. Ali Vincent A. Miller Jeffrey P. Gregg Philip J. Stephens Tianhong Li 《Journal of hematology & oncology》2018,11(1):129
Background
This retrospective study was undertaken to determine if the plasma circulating tumor DNA (ctDNA) level and tumor biological features in patients with advanced solid tumors affected the detection of genomic alterations (GAs) by a plasma ctDNA assay.Method
Cell-free DNA (cfDNA) extracted from frozen plasma (N?=?35) or fresh whole blood (N?=?90) samples were subjected to a 62-gene hybrid capture-based next-generation sequencing assay FoundationACT. Concordance was analyzed for 51 matched FoundationACT and FoundationOne (tissue) cases. The maximum somatic allele frequency (MSAF) was used to estimate the amount of tumor fraction of cfDNA in each sample. The detection of GAs was correlated with the amount of cfDNA, MSAF, total tumor anatomic burden (dimensional sum), and total tumor metabolic burden (SUVmax sum) of the largest ten tumor lesions on PET/CT scans.Results
FoundationACT detected GAs in 69 of 81 (85%) cases with MSAF >?0. Forty-two of 51 (82%) cases had ≥?1 concordance GAs matched with FoundationOne, and 22 (52%) matched to the National Comprehensive Cancer Network (NCCN)-recommended molecular targets. FoundationACT also detected 8 unique molecular targets, which changed the therapy in 7 (88%) patients who did not have tumor rebiopsy or sufficient tumor DNA for genomic profiling assay. In all samples (N?=?81), GAs were detected in plasma cfDNA from cancer patients with high MSAF quantity (P?=?0.0006) or high tumor metabolic burden (P?=?0.0006) regardless of cfDNA quantity (P?=?0.2362).Conclusion
This study supports the utility of using plasma-based genomic assays in cancer patients with high plasma MSAF level or high tumor metabolic burden.13.
The DNA-Delay Mutants of Bacteriophage T4 总被引:16,自引:6,他引:10
Mutants of phage T4 defective in genes 39, 52, 58-61, and 60 (the DNA delay or DD genes) are characterized by a delay in phage DNA synthesis during infection of a nonpermissive Escherichia coli host. Amber (am) mutants defective in these genes yield burst sizes varying from 30 to 110 at 37 C in E. coli lacking an am suppressor. It was found that when DD am mutants are grown on a non-permissive host at 25 C, rather than at 37 C, phage yield is reduced on the average 61-fold. At 25 C incorporation of labeled thymidine into phage DNA is also reduced to 3 to 10% of wild-type levels. Mutants defective in the DD genes were found to promote increased recombination as well as increased base substitution and addition-deletion mutation. These observations indicate that the products of the DD genes are necessary for normal DNA synthesis. The multiplication of the DD am mutants on an Su− host at 37 C is about 50-fold inhibited if prior to infection the host cells were grown at 25 C. This suggests that a compensating host function allows multiplication of DD am mutants at 37 C in the Su− host, and that this function is active in cells grown at 37 C prior to infection, but is inactive when the prior growth is at 25 C. Further results are described which suggest that the products of genes 52, 60, and 39 as well as a host product interact with each other. 相似文献
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We investigated the efficacy of Ocimum basilicum (OB) essential oils for treating depression related behavioral, biochemical and histopathological changes caused by exposure to chronic unpredictable mild stress (CUMS) in mice and to explore the mechanism underlying the pathology. Male albino mice were divided into four groups: controls; CUMS; CUMS plus fluoxetine, the antidepressant administered for pharmacological validation of OB; and CUMS plus OB. Behavioral tests included the forced swim test (FST), elevated plus-maze (EPM) and the open ?eld test (OFT); these tests were performed at the end of the experiment. We assessed serum corticosterone level, protein, gene and immunoexpression of brain-derived neurotropic factor (BDNF) and glucocorticoid receptors (GRs) as well as immunoexpression of glial fibrillary acidic protein (GFAP), Ki67, caspase-3 in the hippocampus. CUMS caused depression in the mice as evidenced by prolonged immobility in the FST, prolonged time spent in the open arms during the EPM test and reduction of open field activity in the OFT. OB ameliorated the CUMS induced depressive status. OB significantly reduced the corticosterone level and up-regulated protein and gene expressions of BDNF and GR. OB reduced CUMS induced hippocampal neuron atrophy and apoptosis, and increased the number of the astrocytes and new nerve cells. OB significantly increased GFAP-positive cells as well as BDNF and GR immunoexpression in the hippocampus. 相似文献
17.
P. Sahab Khan K. P. Skandhan K. Ajesh M. V. P. Siraj 《Biological trace element research》2011,142(3):302-308
The study included evaluation of semen from normal, healthy adults and estimation of gold in seminal plasma from two regions
Nilambur valley (Malappuram District, Kerala Province, India; n = 11), where gold deposit is present and Kollam town (Kerala Province, India; n = 13) where gold is not present in soil. All samples showed normal spermiogram. Gold was estimated in seminal plasma by employing
inductively coupled plasma emission spectrophotometry. It varied from 0.23–1.15 ppm with mean 0.68 ppm in study area while
in control area it was 0.13–0.71 ppm with a mean of 0.41 ppm. Statistical studies (independent ‘t’ test) showed significantly high level (p < 0.05) of gold in seminal plasma from study area. ANOVA test proved that gold in seminal plasma is a significant (p < 0.05) factor for total spermatozoa count and its percentage of motility. 相似文献
18.
Typical preparation of seed samples for infrared (IR) microspectroscopy involves imbibition of the seed for varying time periods followed by cryosectioning. Imbibition, however, may initiate germination even at 4° C with associated changes in the chemistry of the sample. We have found that it is possible to section seeds that are sufficiently hard, such as soybeans, on a standard laboratory microtome without imbibition. The use of dry sectioning of unimbibed seeds is reported here, as well as a comparison of different mounting media and modes of analysis. Glycerol, Tissue-Tek, and ethanol were used as mounting media, and the quality of the resulting spectra was assessed. Ethanol was the preferred mountant, because it dried quickly with no residue and thus did not interfere with the spectrum of interest. Analysis in transmission mode using barium fluoride windows to hold the samples was compared with transmission-reflection analysis with sections mounted on special infrared-reflecting slides. The two modes of analysis performed well in different regions of the spectrum. The mode of analysis (transmission vs. transmission-reflection) should be based on the components of greatest interest in the sample. 相似文献
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20.
JOSEF PFEILSCHIFTER WOLFGANG EBERHARDT RICHARD HUMMEL DIETER KUNZ HEIKO MÜHL DOROTHEA NITSCH CHRISTOPH PLÜSS GABY WALKER 《Cell biology international》1996,20(1):51-58
In recent years, NO, a gas previously considered a potentially toxic chemical, has become established as a diffusible universal messenger mediating cell—cell communication throughout the body. In mammals, NO is a recognized mediator of blood vessel relaxation that helps to maintain blood pressure. In the central nervous system NO acts as a non-conventional neurotransmitter and participates in the establishment of long-term plasticity required for memory formation. In addition, NO is responsible for some parts of the host response to sepsis and inflammation and contributes to certain disease states. A number of strategies have emerged with regard to a pharmacological control of pathological NO overproductions. This review will discuss these novel therapeutic approaches that may provide new means for clinical medicine. 相似文献