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81.
Pankaj K. Sikka Kenneth E. McMartin 《In vitro cellular & developmental biology. Animal》1996,32(5):285-291
Summary Anin vitro model to establish primary and subcultures of rat kidney proximal tubule (RPT) cells is described. After excising the kidneys
and separating the cortex, the cortical tissue is digested with the enzyme DNAse-collagenase (Type I) resulting in a high
yield of viable RPT Cells. The isolated RPT cells are then seeded onto rat tail collagen-coated surfaces and grown to confluency
in a serum-free, hormonally defined medium. The cell yield can be increased by transfering the conditioned medium on Day 1
to more rat tail collagen-coated surfaces. RPT cell attachment and morphology was better on rat tail collagen-coated surfaces
than on bovine collagen Type I coated surfaces. The culture medium was a 1∶1 mixture of Ham’s F-12 and Dulbecco’s modified
Eagle’s medium supplemented with bovine serum albumin, insulin, transferrin, selenium, hydrocortisone, triiodothyronine, epidermal
growth factor, and glutamine. The RPT cells became confluent in 7–10 d, at which point they could be subcultured by trypsinizing
and growth in the same medium. In some studies, 10 ng/ml cholera toxin was added to the culture medium. We could passage the
RPT cells up to 14 times in the presence of cholera toxin. The cells were investigated for activity of several markers. The
cells were histochemically positive for alkaline phosphatase and γ-glutamyl transpeptidase activity and synthesized the intermediate
filament pankeratin. The RPT cells displayed apically directed sodium-dependent active glucose transport in culture. Hence,
the RPT cells retain structural and functional characteristics of transporting renal epithelia in culture. This rat cell culture
model will be a valuable tool for substrate uptake and nephrotoxicity studies. 相似文献
82.
Adle Martial Isabelle Gaillard Jean-Marc Engasser Annie Marc 《Enzyme and microbial technology》1995,17(12):1062-1066
A homemade serum-free medium containing a low protein level under 0.1 g l−1 has been proved to support long-term cultures of VO 208 hybridoma cells successfully up to 50 days. The low protein level was achieved by supplying the lipids through liposomes containing cholesterol, oleic acid,
- dipalmitoyl phosphatidylcholine, and bovine serum albumin. The influence of the liposome content in the feeding medium was studied in a continuous culture performed with step variations of the liposomes level, from 7.5 to 30 ml l−1. The cell density decreased at the highest liposomes content while it became higher with 7.5 or 12 ml l−1 of liposomes. For each step variation appeared a transitory activation of the specific rates of nutrient consumption, metabolite production and antibody secretion, as well as a transitory decrease of the specific cell growth rate. The overall structure of the antibodies was not affected during the culture. 相似文献
83.
Semicontinuously grown wild carrot ( Daucus carota L.) cells were used in an investigation of the effect of culture medium pH on ammonium uptake in suspension cultures as a first step in exploring the relationship between pH and anthocyanin biosynthesis. In contrast to published data showing decreasing uptake rates with decreasing culture medium pH, ammonium-limited, semicontinuous carrot cell cultures showed a 25% greater ammonium uptake rate at pH 4.5 than at pH 5.5. When cells that had been grown semicontinuously in medium with a pH of 4.5 or 5.5 were grown in batch cultures at pH 4.5, 5.5 or 6.5 the ammonium uptake rates were those of the semicontinuous cultures, indicating that the pH of the batch culture medium had no effect on ammonium uptake rates over 7 days. The cell culture was composed of very small aggregates when it was grown semicontinuously in medium at pH 4.5, but was composed of large aggregates when it was grown semicontinuously in medium at pH 5.5. The aggregation/disaggregation of the cells was pH dependent, as changing the pH of the semicontinuous culture medium altered the extent of the aggregation. We conclude that the change in culture medium pH caused the cells to aggregate or disaggregate which in turn decreased or increased the rate of ammonium uptake from the medium. 相似文献
84.
Abstract: Quantification of the size of epiphytic bacterial populations and characterization of their composition involves definition of a sampling strategy in time and space, the choice of methods for liberating the bacteria from the leaf surface and for recovering them for subsequent determination of the number of viable or culturable cells. This literature review focuses on some of the issues related to these choices. After briefly reviewing the different types of epiphytic colonizers we consider the biological, methodological, and statistical consequences of the choice of the sampling unit and of the spatial and temporal variability of population size and composition for epiphytic bacteria. The different methods available for the detection and enumeration of naturally occurring microorganisms in the phyllosphere are discussed. Advantages and drawbacks of each are described in this review designed as a 'hands-on' guide. 相似文献
85.
甜玉米籽实含糖量的配合力分析 总被引:2,自引:0,他引:2
乔春贵 王玉兰 禹航 马景勇 王思远 张连发QIAO Chun-Gui WANG Yu-Lan YU Hang MA Jing-Yong WANG Si-Yuan 《遗传》1995,17(4):25-27
采用不完全双列杂交设计研究了 6个母本3个父本甜玉米自交系籽实含糖量的配合力效应。结果表明,父母本一般配合力和特殊配合力效应均方都显著。根据各亲本的表现把亲本5033归为一般配合力高而特殊配合力方差大的最理想类型;亲本5012和5011属一般配合力高而特殊配合力方差小的类型;亲本5018、5034、5028和5024为一般配合力低,但特殊配合力方差高的类型; 亲本5023和5009属一般配合力效应和特殊配合力方差都低的类型,最缺少实用价值。 相似文献
86.
Evaluation of the serum-free medium MDSS2 for the production of poliovirus on vero cells in bioreactors 总被引:2,自引:0,他引:2
The serum-free medium MDSS2 (Merten et al., 1994), was used for cultivating Vero cells as well as for producing poliovirus
(Sabin type 1) in static and in perfused micro-carrier cultures. At slightly different growth rates of 0.0120/h and 0.0106/h,
respectively, static cultures in serum-containing (SCM) and serum-free (SFM) medium produced titers of 106.75 and 106.67 TCID50 per 50 μl; signifying a specific productivity of 0.89 and 1.07 TCID50/c.
Serum-free bioreactor cultures of Vero cells on DEAE-dextran microcarriers at 6.25 g/l produced cell densities of about 1.5×106c/ml. After infection with virus (multiplicity of infection (MOI) 0.1–0.3) titers of about 6.3×108 TCID50/ml were obtained, signifying an average specific productivity of 7.1 TCID50/c.h. Although these values were 4 and
2 fold, respectively, higher than in classical resum-based production processes (Montagnon et al. Dev. biol. Stand. 1981,
47, 55), a reference culture, for which cell growth was done in SCM and only virus production was done in SFM, produced 2×109 TCID/ml with an average specific virus production rate of 18.9 TCID50/c.h. The differences between the fully serum-free and
our reference process were mainly due to physiological differences of cells grown in SCM and SFM and also due to strongly
modified consumption kinetics after virus infection leading to limitations of one or several essential medium compounds, like
glucose and amino acids. Avoiding these limitations by increasing the residual concentration of glucose, glutamine, histidine,
and SH-amino acids, led to specific virus production rates (of about 17.9 TCID59/c.h.) comparable to those found in the reference
virus production process. The optimisation of the production of the poliovirus (Sabin 1) will be described with respect to
the modification of the medium composition.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
87.
Marc Lecouvey Céline Frochot Laurent Miclo Piotr Orlewski Michel Marraud Jean-Luc Gaillard Manh Thong Cung Régis Vanderesse 《Letters in Peptide Science》1997,4(4-6):359-364
The conformation of a benzodiazepine-like decapeptide corresponding tothe YLGYLEQLLR fragment of a casein has been examined in a sodium dodecylsulfate micellar medium using circular dichroism, two-dimensional1H NMR spectroscopy and restrained molecular dynamicssimulation. The decapeptide adopts an amphipathic 310-helicoidstructure in which theE6···R10 ionic bridgestabilizes the C-terminus. 相似文献
88.
Shinji Hosoi Mitsuo Satoh Hiromasa Miyaji Tatsunari Nishi Tamio Mizukami Mamoru Hasegawa Seiga Itoh Tatsuya tamaoki 《Cytotechnology》1995,19(1):1-10
Pro-UKS1 was designed as a thrombin-resistant derivative of pro-urokinase (pro-UK) by introducing a glycosylation site using site-directed mutagenesis. An expression plasmid for pro-UKS1, pMo1UKS1SEd1-5, was constructed and introduced into Namalwa KJM-1 cells (Hosoiet al., 1988), and cells resistant to G418 and Methotrexate (MTX) were obtained. Amongst them, the highest pro-UKS1 producer (resistant to 500 nM of MTX), clone 41-8, was selected and further characterized. Clone 41-8 was cultured in serum-free ITPSGF medium (Hosoiet al., 1988). Under the conventional conditions, the concentration of pro-UKS1 reached 26 g ml–1. Addition of glucose and tri-iodothyronine (T3) improved productivity, and the maximal productivity of pro-UKS1 was 67 g ml–1 day–1. In this conditioned medium, content of pro-UKS1 was above 80% of total proteins.Abbreviations BSA
bovine serum albumin
- dhfr
dihydrofolate reductase
- HEPES
4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid
- kb
kilobase pairs
- kDa
kilodaltons
- MTX
Methotrexate
- PBS
phosphate buffered saline
- pro-UK
pro-urokinase
- SDS-PAGE
sodium dodecyl sulfate-polyacrylamide gel electrophoresis
- T3
tri-iodothyronine
- Tween-PBS
phosphate buffered saline containing 0.05% Tween 80 相似文献
89.
Two series of amino-modified silicate gels prepared by sol-gel processing were used to absorb Cu(II), Ni(II), Co(II), Mn(II) and Cr(III) from aqueous solutions. These easily prepared sorbents with various content of primary amino groups in series (A) or primary and secondary amino groups in series (AA) have reasonable stability. The gel composition, time and concentration dependence of the uptake of the metal ions by these materials were studied systematically. These materials would be further used as supports to disperse catalytically active phases by conventional wet chemical procedures. Apart from this they demonstrate potential for the preconcentration aid for transition metal analysis. 相似文献
90.
R. Van Potter Theresa Ruh Evanson Debra P. Gayda James A. Gurr 《In vitro cellular & developmental biology. Plant》1984,20(9):723-731
Summary The induction and decay of ornithine decarboxylase (ODC) by insulin and asparagine in cultures of H4-II-EC3 (H35) hepatoma
cells was studied in a modified Waymouth medium in the presence of fetal bovine serum (FBS) and in serum-free media. The insulin
response was enhanced by the presence of asparagine although the effect of asparagine was not so much on the initial increase
as it was on a slowing of the decline after the maximum was reached at 6 to 8 h after the supplements were added together
with fresh medium. In all cases the initial ODC activity was zero at zero time for addition of media and supplements, and,
after reaching the maximum, activity declined to near zero by 24 h. Fetal bovine serum gave induction that followed a similar
time course but was inferior to the combintion, of insulin plus asparagine and, in fact, FBS inhibited the latter response.
Putrescine (the product formed from ornithine by ODC), at 10−5
M, markedly inhibited the induction of ODC by insulin or FBS, but the inhibition was less when asparagine was present.
This work was supported in part by Grants CA-07175, CA-22484, and CA-17334 from the National Cancer Institute. D. P. G. is
a Predoctoral Fellow at the Food Research Institute, supported by a fellowship from the Monsanto Fund and by NIH Grant R01-AI
15693 to Prof. Michael W. Pariza, Food Research Institute, University of Wisconsin, Madison. 相似文献