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排序方式: 共有708条查询结果,搜索用时 15 毫秒
1.
2.
Effect of valproate on lactate and glutamine metabolism by rat renal cortical tubules 总被引:3,自引:0,他引:3
M Doval M Culebras A Lopez-Farré M Rengel A Gougoux P Vinay J M Lopez-Novoa 《Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine (New York, N.Y.)》1989,190(4):357-364
The metabolic effects of sodium valproate (VPA) on rat renal cortical tubules have been examined. When 1 or 5 mM lactate was used as substrate in the incubation medium, VPA decreased markedly the lactate uptake by the tubules. When 1 or 5 mM glutamine was used, the addition of VPA accelerated glutamine uptake, ammoniagenesis, but also stimulated markedly the accumulation of lactate and pyruvate produced from glutamine. VPA had a dose-dependent inhibitory effect on gluconeogenesis from both glutamine and lactate. With 5 mM glutamine, VPA also induced a significant accumulation of glutamate in the medium. The oxygen consumption by the tubules was diminished by 40% following VPA addition. It is concluded that VPA modifies the metabolism of rat cortical tubules by interfering with the oxidation of natural substrates and stimulates in this fashion the production of ammonia by kidney tubules. 相似文献
3.
R. Ashton Lavoie Jeffrey T. Zugates Andrew T. Cheeseman Matt A. Teten Srivatsan Ramesh Julia M. Freeman Summer Swango Jeremy Fitzpatrick Amod Joshi Bradley Hollers Zufan Debebe Tyler K. Lindgren Amber N. Kozak Vinay K. Kondeti Mary K. Bright Eric J. Yearley Alexander Tracy Jacob A. Irwin Michael Guerrero 《Biotechnology and bioengineering》2023,120(10):2953-2968
Adeno-associated virus-based gene therapies have demonstrated substantial therapeutic benefit for the treatment of genetic disorders. In manufacturing processes, viral capsids are produced with and without the encapsidated gene of interest. Capsids devoid of the gene of interest, or “empty” capsids, represent a product-related impurity. As a result, a robust and scalable method to enrich full capsids is crucial to provide patients with as much potentially active product as possible. Anion exchange chromatography has emerged as a highly utilized method for full capsid enrichment across many serotypes due to its ease of use, robustness, and scalability. However, achieving sufficient resolution between the full and empty capsids is not trivial. In this work, anion exchange chromatography was used to achieve empty and full capsid resolution for adeno-associated virus serotype 5. A salt gradient screen of multiple salts with varied valency and Hofmeister series properties was performed to determine optimal peak resolution and aggregate reduction. Dual salt effects were evaluated on the same product and process attributes to identify any synergies with the use of mixed ion gradients. The modified process provided as high as ≥75% AAV5 full capsids (≥3-fold enrichment based on the percent full in the feed stream) with near baseline separation of empty capsids and achieved an overall vector genome step yield of >65%. 相似文献
4.
It has been hypothesized that humans with familial renal hypouricemia may have a generalized defect of urate transport across cell membranes due to the genetic deletion of a specific carrier, a defect similar to that reported in the Dalmatian dog. In this study the transport of urate labelled with carbon 14 by the erythrocytes of four patients with familial renal hypouricemia was identical to that of five healthy controls. The addition of hypoxanthine to the incubation medium inhibited the transport to a similar extent in the two groups of patients, demonstrating the presence of a carrier specific for urate. This carrier was also found to be present in the erythrocytes of Dalmatian and mongrel dogs. Thus, the renal anomaly causing the hypouricemia in both species is not related to a generalized deletion of a urate-transporting protein on cell membranes. 相似文献
5.
G A Blaise J No?l E Villeneuve C Hollman B Vinet Y Boulanger P Vinay 《Canadian journal of physiology and pharmacology》1991,69(6):752-760
The effect of three volatile anesthetics (halothane, enflurane, and isoflurane) on coronary flow and metabolic state of isolated rat hearts was studied. These anesthetics are coronary dilators and their effects are dose dependent. At 2 MAC (minimum alveolar concentration), isoflurane, enflurane, and halothane increase coronary flow by 114 +/- 5.9, 93 +/- 6.1, and 77 +/- 6.4%, respectively (p less than 0.001). At these concentrations, they also have a modest but significant metabolic effect causing a 30% reduction in myocardial ATP and phosphocreatine levels, with no significant modification in ADP and AMP concentrations. Energy charge and lactate/pyruvate ratio were also unaffected by these anesthetics. The vascular and metabolic effects were reversible within 2 and 30 min, respectively. Perfusion of the hearts with a Krebs-Henseleit solution without Pi did not interfere with the vascular and the metabolic effect of the anesthetics; however, in this case, ATP and phosphocreatine concentration did not return to control levels after their discontinuation despite full recovery of the vascular effect. These data suggest that the volatile anesthetics have direct coronary vascular and myocardial metabolic effects and that these effects occur independently. 相似文献
6.
Arvind K. Virmani Bashoo Naziruddin Vinay C. Desai Jon P. Lowry Donald C. Graves Goverdhan P. Sachdev 《In vitro cellular & developmental biology. Animal》1992,28(2):120-127
Summary The purpose of this investigation was to provide evidence for the secretion of high molecular weight mucins, CTM-A and CTM-B,
in primary culture of canine tracheal epithelial (CTE) cells. The cells were isolated from tracheas of mongrel dogs by pronase
treatment. Primary cultures of the epithelial cells were established using ICN cellagen inserts in Dulbecco’s modified Eagle’s/F12
medium supplemented with growth factors and could be maintained for up to 23 days. The evidence for the mucin secretion in
culture medium and their localization in the cells was established by a) positive immunocytochemical staining using specific
antibodies developed against purified native as well as deglycosylated CTM-A and CTM-B; b) incorporation of labeled amino
acids, followed by electrophoresis and autoradiography detection of glycoconjugates purified from the culture medium; c) comparison
of the amino acid compositions of mucin purified from canine tracheal pouch secretions and that purified from the culture
medium; and d) Western blot analyses using specific polyclonal antibodies directed against deglycosylated CTM-A and CTM-B.
Immunoaffinity purified secreted labeled glycoconjugates were resistant to hyaluronidase treatment. The effects of cyclic
AMP (1 × 10−5
M), dibutyryl cyclic AMP (1 × 10−5
M), 8-bromocyclic AMP (1 × 10−5
M), and prostaglandin E1 (1 × 10−6
M) on mucin secretion by CTE cells were also investigated. Secretion of mucins by CTE cells in culture was considerably more
enhanced by 8-bromocyclic AMP than that observed for other secretagogues used in this study. 相似文献
7.
8.
Gamma oscillations (30 to 80 Hz) have been hypothesized to play an important role in feature binding, based on the observation that continuous long bars induce stronger gamma in the visual cortex than bars with a small gap. Recently, many studies have shown that natural images, which have discontinuities in several low-level features, do not induce strong gamma oscillations, questioning their role in feature binding. However, the effect of different discontinuities on gamma has not been well studied. To address this, we recorded spikes and local field potential from 2 monkeys while they were shown gratings with discontinuities in 4 attributes: space, orientation, phase, or contrast. We found that while these discontinuities only had a modest effect on spiking activity, gamma power drastically reduced in all cases, suggesting that gamma could be a resonant phenomenon. An excitatory–inhibitory population model with stimulus-tuned recurrent inputs showed such resonant properties. Therefore, gamma could be a signature of excitation–inhibition balance, which gets disrupted due to discontinuities.Gamma oscillations (30-80 Hz) in visual cortex have been hypothesized to play an important role in feature binding, but this role has recently been questioned. This study shows that visual stimulus-induced gamma oscillations are highly attenuated with even small discontinuities in the stimulus. This "resonant" behaviour can be explained by a simple excitatory-inhibitory model in which discontinuities lead to a small reduction in lateral inputs. 相似文献
9.
Dusane DH Pawar VS Nancharaiah YV Venugopalan VP Kumar AR Zinjarde SS 《Biofouling》2011,27(6):645-654
A tropical marine bacterium isolated from the hard coral, Symphyllia sp. was identified as Serratia marcescens on the basis of morphological, biochemical and 16S rDNA analysis. The bacterium showed antimicrobial activity towards the pathogens Candida albicans and Pseudomonas aeruginosa and the marine biofouling bacterium Bacillus pumilus. S. marcescens displayed biosurfactant activity as evidenced by drop collapse, blood hemolysis and surface tension reduction (52.0-27 mN m(-1)). The active compound was purified by solvent extraction and silicic acid chromatography. Characterization was by thin layer chromatography, gas chromatography mass spectroscopy (GC-MS), Fourier transform infrared (FTIR) spectroscopy and (1)H as well as (13)C nuclear magnetic resonance (NMR) analysis. The surfactant was found to be a glycolipid composed of glucose and palmitic acid. The glycolipid prevented adhesion of C. albicans BH, P. aeruginosa PAO1 and B. pumilus TiO1. The glycolipid also disrupted preformed biofilms of these cultures in microtitre plates. Confocal laser scanning microscopy and electron microscopy confirmed the effective removal of biofilms from glass surfaces. The glycolipid derived from S. marcescens could thus serve as a potential anti-biofilm agent. 相似文献
10.