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991.
992.
Much attention has been devoted to identifying genomic patterns underlying the evolution of the human brain and its emergent advanced cognitive capabilities, which lie at the heart of differences distinguishing humans from chimpanzees, our closest living relatives. Here, we identify two particular intragene repeat structures of noncoding human DNA, spanning as much as a hundred kilobases, that are present in human genome but are absent from the chimpanzee genome and other nonhuman primates. Using our novel computational method Global Repeat Map, we examine tandem repeat structure in human and chimpanzee chromosome 1. In human chromosome 1, we find three higher order repeats (HORs), two of them novel, not reported previously, whereas in chimpanzee chromosome 1, we find only one HOR, a 2mer alphoid HOR instead of human alphoid 11mer HOR. In human chromosome 1, we identify an HOR based on 39-bp primary repeat unit, with secondary, tertiary, and quartic repeat units, fully embedded in human hornerin gene, related to regenerating and psoriatric skin. Such an HOR is not found in chimpanzee chromosome 1. We find a remarkable human 3mer HOR organization based on the ~1.6-kb primary repeat unit, fully embedded within the neuroblastoma breakpoint family genes, which is related to the function of the human brain. Such HORs are not present in chimpanzees. In general, we find that human-chimpanzee differences are much larger for tandem repeats, in particularly for HORs, than for gene sequences. This may be of great significance in light of recent studies that are beginning to reveal the large-scale regulatory architecture of the human genome, in particular the role of noncoding sequences. We hypothesize about the possible importance of human accelerated HOR patterns as components in the gene expression multilayered regulatory network.  相似文献   
993.
The syntheses of the novel C-5 substituted pyrimidine derivatives of l-ascorbic acid containing free hydroxy groups at C-2' (6-10) or C-2' and C-3' (11-15) positions of the lactone ring are described. Debenzylation of the 6-chloro- and 6-(N-pyrrolyl)purine derivatives of 2,3-O,O-dibenzyl-l-ascorbic acid (16 and 17) gave the new compounds containing hydroxy groups at C-2' (18) and C-2' and C-3' (19 and 20). Z- and E-configuration of the C4'C5' double bond and position of the lactone ring of the compounds 6-9 were deduced from their one- and two-dimensional (1)H and (13)C NMR spectra and connectivities in NOESY and HMBC spectra. Compounds 15 and 18 showed the best inhibitory activities of all evaluated compounds in the series. The compound 15 containing 5-(trifluoromethyl)uracil showed marked inhibitory activity against all human malignant cell lines (IC(50): 5.6-12.8 microM) except on human T-lymphocytes. Besides, this compound influenced the cell cycle by increasing the cell population in G2/M phase and induced apoptosis in SW 620 and MiaPaCa-2 cells. The compound 18 containing 6-chloropurine ring expressed the most pronounced inhibitory activities against HeLa (IC(50): 6.8 microM) and MiaPaCa-2 cells (IC(50): 6.5 microM). The compound 20 with 6-(N-pyrrolyl)purine moiety showed the best differential inhibitory effect against MCF-7 cells (IC(50): 35.9 microM).  相似文献   
994.
995.
During two consecutive years (2010 and 2011) we evaluated the impact of Progerbalin LG® (mixture of gibberellins (GA4+7) and N 6-benzyladenine) on fruit weight, fruit dimensions, elongation, geometric mean diameter or fruit size, aspect ratio, surface area and fruit volume of five apple cultivars belonging to ‘Red Delicious’ group (‘Hapke’ grafted on M.9 and M.26, ‘Hi Red’, ‘Starking’ and ‘Top Red’ on M.9, and ‘Red Chief Camspur’ on MM.106 rootstock). Trees were sprayed twice with 30, 50 or 100 ml L?1 i.e. between 80 % of open flowers and the following petal fall (first treatment), and 10 days after first application (second treatment); control trees were not sprayed. Results showed that the lowest dose increased fruit weight in all cultivars, except ‘Top Red’ and ‘Red Chief Camspur’; this dose promoted fruit dimensions, fruit size and elongation in ‘Hapke’ on both rootstocks, and also fruit dimensions, surface area and fruit volume in ‘Hi Red’. Regarding ‘Starking’, different doses of Progerbalin LG® did not affect other properties evaluated, but season played an important role in these cases. In contrast, the highest dose of this hormone improved all physical attributes in ‘Top Red’ and ‘Red Chief Camspur’, except elongation and/or aspect ratio. In some cases, good values were found in control treatment.  相似文献   
996.
The unique response of desiccation-tolerant, or resurrection plants, to extreme drought is accompanied by major changes in the protein pool, raising the possibility of the involvement of proteases. We detected and characterized proteases present in their active state in leaf extracts of desiccated Ramonda serbica Pan?., a resurrection plant from the Balkan Peninsula. Plants desiccated under laboratory conditions and maintained in anhydrobiosis for 4 and 14 months revived upon rehydration. Protease activities were determined spectrophotometrically in solution and by zymography on gels. Several endo- and aminopeptidases were detected and characterized by their pH profiles. Their enzyme class was determined using specific inhibitors. Those with higher activities were a serine endopeptidase active against Bz-Arg-pNA with a pH optimum around 9, and aminopeptidases optimally active at pHs from 7 to 9 against Leu-pNA, Met-pNA, Phe-pNA, Pro-pNA and Ala-pNA. The levels of their activities in leaf extracts from desiccated plants were significantly higher than those from rehydrated plants and from regularly watered plants, implying their involvement in the recovery of vegetative tissues from desiccation.  相似文献   
997.
This work examines the bioaccumulated organochlorine compounds in Muraena helena to draw attention to this species as a potential bioindicator organism. The morays were caught in the East Adriatic Sea, Elaphite Islands, near Dubrovnik, Croatia (lat: 42°45′38.8″; long: 17°45′53.6″) at the same location in summer (August, 2009) and winter (January, 2010), at depths from 5 to 10 m. Nine fish were caught by longline hooks per each field trip (total in summer and winter, N = 18). No single fish was free of organochlorines (OC), but not all pesticides were present in every fish. The concentration level was: Endrin > ppDDE > Heptachlor epoxide > Heptachlor > Aldrine > Lindane > βHCH > δHCH > Endrin aldehyde). Endrin was the only pesticide approaching the maximum concentrations proposed by the European Union and Croatia (summer max. concentration = 14.75 μg kg?1; winter max. concentration = 8.35 μg kg?1). All other pesticides ranged from 0.1 to 0.7 μg kg?1. Heptachlor was absent in winter and δ‐HCH and Endrin aldehyde in summer, while Lindane and pp‐DDE had higher (P ≤ 0.05) concentrations in summer. Other residues had similar seasonal concentration levels. The p‐DDT was similar as in other biota from the Adriatic or Mediterranean. HCH concentrations corresponded to those found in organisms from the Italian area of the Adriatic. The endocrine and reproductive disrupting potential of the detected OCs are bases for future studies. Results show that morays are a good bioindicator model, with slight interspecies and seasonal variability in OC bioaccumulation as a consequence of diverse food consumption.  相似文献   
998.
Chronic oxidative stress plays an important role in depression. The aim of present study was to examine the stress-induced changes in serum corticosterone (CORT) levels, cytosolic protein carbonyl groups, malondialdehyde (MDA), reduced glutathione (GSH), nitric oxide (NO) and total superoxide dismutase (SOD) activity in the prefrontal cortex versus hippocampus of male Wistar rats exposed to acute (2 h of immobilization or cold), chronic (21d of social isolation) stress, and their combination (chronic + acute stress). The subcellular distribution of nuclear factor-κB (NF-κB) and cytosolic cyclooxygenase 2 (COX-2) protein expressions were also examined. Depressive- and anxiety-like behaviors were assessed via the forced swim, sucrose preference, and marble burying tests in chronically isolated rats. Although both acute stressors resulted in elevated CORT, increased MDA in the prefrontal cortex and NF-κB activation accompanied by increased NO in the hippocampus were detected only following acute cold stress. Chronic isolation resulted in no change in CORT levels, but disabled appropriate response to novel acute stress and led to depressive- and anxiety-like behaviors. Increased oxidative/nitrosative stress markers, likely by NF-κB nuclear translocation and concomitant COX-2 upregulation, associated with decreased SOD activity and GSH levels, suggested the existence of oxidative stress in the prefrontal cortex. In contrast, hippocampus was less susceptible to oxidative damage showing only increase in protein carbonyl groups and depleted GSH. Taken together, the prefrontal cortex seems to be more sensitive to oxidative stress than the hippocampus following chronic isolation stress, which may be relevant for further research related to stress-induced depressive-like behavior.  相似文献   
999.
The aim of the present study was to investigate the distribution of uranium (uranyl nitrate hexahydrate, UN) in muscle and organs (kidney, liver, and brain) of broilers, after a 7-day contamination with UN and administration of two different adsorbents (organobentonite and organozeolite). The birds were contaminated during 7 days with 25 mg/UN per day. Adsorbents were given via gastric tube, immediately after contamination with UN. In group 1 that did not receive any adsorbents, histopathological changes in the contaminated broilers were observed in small intestine, liver, and kidney in the form of necrosis of intestinal villi, oedema and cytoplasmic vacuolation of hepatocytes, and dystrophic changes in the kidney tubules epithelium. Organobentonite administered via gastric tube (group 2) reduced uranium distribution by 66 % in kidney, 81 % in liver, and 34 % in brain. In group 3, administration of organozeolite reduced uranium distribution by 67 % in kidney, 68 % in liver, and 49 % in brain. In groups 2 and 3, where the broilers received adsorbents immediately after the UN contamination, no histopathological lesions were observed.  相似文献   
1000.
Nine diarylheptanoids, 1 – 9 , catechin ( 11 ), and a phenolic glucoside, 10 , were isolated from the bark of green alder (Alnus viridis). Four of the isolated compounds, i.e., 2, 5, 8, 10 , are new. The structures of 1 – 11 were determined on the basis of spectroscopic data. All isolated compounds were evaluated for their in vitro protective effects on chromosome aberrations in peripheral human lymphocytes using cytokinesis‐block micronucleus (CBMN) assay. Almost all of them exerted a pronounced effect of decreasing DNA damage of human lymphocytes, acting stronger than the known synthetic protector amifostine.  相似文献   
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