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991.
Hexadecane mineralization by a bacterial consortium isolated from a non heavily contaminated coastal seawater was largely increased by an enrichment with Inipol EAP 22 (10% w/w). In the conditions of the experiment, the efficiency of this oleophilic nutrient is linked to the organic N and P sources (urea and lauryl-phosphate) and, to a lesser extent, to the presence of a readily available carbon source (oleic acid). Otherwise, the micro emulsion nature of the formulation and its physical properties seem to play a major role in accelerating hexadecane mineralization.  相似文献   
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994.
Interleukin-1 (IL-1) has been implicated in the regulation of the expression of various matrix metalloproteinases (MMPs) in many mesenchymal cell types, but its role in liver myofibroblasts (MFs) has not been elucidated. A myofibroblast-like cell line, MG2, was derived from an isolate of rat hepatic stellate cells (HSCs). These cells expressed desmin, vimentin, smooth muscle -actin, and fibulin-2. Using a recombinant IL-1 at 5 ng/ml, it was shown that IL-1 would upregulate, while IL-1Ra, an IL-1 receptor antagonist, would down-regulate the expression of IL-1 mRNA in MG2 cells, indicating the presence of an autostimulatory loop of IL-1 in these cells. Besides, a paracrine source of IL-1 may be produced from Kupffer cells, as we showed primarily cultured Kupffer cells responded much more remarkably than MG2 cells to lipopolysaccharide stimuli to produce both IL-1 and IL-1. Recombinant IL-1 upregulated the expression of both MMP-9 and -13, and the induction of MMP-13 but not MMP-9 could be inhibited by SB203580, an inhibitor of p38. Similarly, in primarily cultured human liver MFs, upregulation of MMP-1 by IL-1 was also shown to be inhibited by SB203580. All of these data suggested that, during liver inflammation, IL-1 produced by an autocrine model from MFs or by a paracrine model from Kupffer cells might play a crucial role in the remodeling of liver fibrosis through an either p38-dependent or p38-independent pathway to regulate the expression of various MMPs by liver MFs.  相似文献   
995.

Background  

There is an ongoing discussion about age limits for deep brain stimulation (DBS). Current indications for DBS are tremor-dominant disorders, Parkinson's disease, and dystonia. Electrode implantation for DBS with analgesia and sedation makes surgery more comfortable, especially for elderly patients. However, the value of DBS in terms of benefit-risk ratio in this patient population is still uncertain.  相似文献   
996.
Pulmonary involvement is common in sarcoidosis, an immune-mediated inflammatory disorder that is characterized by non-caseating granulomas in tissue. Sarcoid patients with advanced pulmonary disease, especially end-stage pulmonary fibrosis, risk developing pulmonary hypertension (World Health Organization group III pulmonary hypertension secondary to hypoxic lung disease). Increased levels of endothelin (ET)-1 in plasma and bronchoalveolar lavage of some sarcoid patients suggest that ET-1 may be driving pulmonary fibrosis and sarcoidosis-associated pulmonary hypertension. Although a relationship between raised levels of ET-1 and clinical phenotype is yet to be identified, early evidence from studies of ET-1 blockade with drugs such as bosentan is encouraging. Such therapy possibly could be combined with standard anti-inflammatory agents to improve outcome.  相似文献   
997.
Achievement of transposon mediated germline transgenesis in a basal chordate, Ciona intestinalis, is discussed. A Tc1/mariner superfamily transposon, Minos, has excision and transposition activities in Ciona. Minos enables the creation of stable transgenic lines, enhancer detection, and insertional mutagenesis.  相似文献   
998.
Nucleosides are neuromodulators that have a wide range of biological roles in the brain. In order to better understand the function of nucleosides in the human central nervous system (CNS), we constructed a nucleoside map showing the concentration of various nucleosides and their metabolites using post mortem samples from 61 human brain areas and 4 spinal cord areas. We evaluated in vivo tissue levels of four nucleosides (uridine, inosine, guanosine, and adenosine) and three of their metabolites (uracil, hypoxanthine, and xanthine). The concentrations of nucleosides were unevenly distributed across different brain regions, where the highest levels were found in the cerebral cortex and basal ganglia, whereas the lowest concentrations were located in the locus coeruleus, the zona incerta, the substantia nigra, and the inferior colliculus. The regional differences in nucleoside levels in the CNS may reflect the distinct physiological functions adopted by these compounds in different brain areas.  相似文献   
999.
An efficient shoot organogenesis system has been developed from mature plants of selected elite clones of Eucalyptus tereticornis Sm. Cultures were established using nodal explants taken from freshly coppice shoots cultured on Murashige and Skoog medium containing 58 mM sucrose, 0.7% (w/v) agar (MS medium) and supplemented with 2.5 μM benzyladenine (BA) and 0.5 μM α-naphthaleneacetic acid (NAA). Shoot organogenesis was achieved from leaf segments taken from elongated microshoots on MS medium supplemented with 5.0 μM BA and 1.0 μM 2,4-dichlorophenoxyacetic acid (2,4-D). The addition of cefotaxime to the medium promoted shoot differentiation, whereas carbenicillin and cephalexin inhibited shoot differentiation. Maximum shoot bud organogenesis (44.6%) occurred in explants cultured on MS medium supplemented with 5.0 μM BA, 1.0 μM 2,4-D and 500 mg/l cefotaxime. Leaf maturity influenced shoot regeneration, with maximum shoot organogeneisis (40.5%) occurring when the source of explants was the fifth leaf (14–16 days old) from the top of microshoot. Shoot organogenic potential also varied amongst the different clones of E. tereticornis. Random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) analyses indicated clonal uniformity of the newly formed shoots/plants, and these were also found to be true-to-type.  相似文献   
1000.
Singapore is located near the equator, off the southern tip of the Malay Peninsula. The whole country consists mostly of lowland. It has many interesting types of natural habitats such as primary rain forest, freshwater swamp forest, mangroves, secondary forests, shrub, grasslands, and urban parks and fields. The climate is equatorial with relatively uniform temperature and high humidity. Unfortunately, many of the natural habitats and the native orchids which thrive there have disappeared due to habitat destruction. Some 226 species of native orchids have been recorded in Singapore. However, of these 178 are considered to be extinct, and only five are common. The orchid conservation programme aims to monitor existing species, explore ways to conserve their germplasm, and increase their numbers in natural, semi-natural, and urban environments through ex-situ seedling culture and subsequent re-introduction into appropriate habitats, including roadside trees, parks and natural areas. In the first phase of the programme, we have successfully propagated and carried out experiments of re-introduction on five species of native orchids, namely, Grammatophyllum speciosum, Bulbophyllum vaginatum, Bulbophyllum membranaceum, Cymbidium finlaysonianum and Cymbidium bicolor. Survival percentages 8-yr after the reintroduction events ranged from 10 to 95 for G. speciosum, the target species of the earliest re-introduction experiments. Size of the seedlings at reintroduction, host trees, and relative humidity seemed to play significant roles in the success rate of the reintroductions.  相似文献   
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