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1.
Masahiro Matsuda Shiro Shigeta Koichi Okutani 《Marine biotechnology (New York, N.Y.)》1999,1(1):68-73
A marine Pseudomonas species WAK-1 strain simultaneously produces extracellular glycosaminoglycan and sulfated polysaccharide. Among the antiviral
activities tested for these polysaccharides, the latter showed anti-HSV-1 activity in RPMI 8226 cells (50% effective concentration
is 1.4 μg/ml). Oversulfated derivatives of these polysaccharides prepared by dicyclohexylcarbodiimide-mediated reaction for
both polysaccharides showed antiviral activities against influenza virus type A (for glycosaminoglycan, 50% effective concentration
is 11.0 μg/ml; for another, 2.9 μg/ml). Glycosaminoglycan, sulfated polysaccharide, and their chemically synthesized oversulfated
derivatives did not show antiviral activities against influenza virus type B and human immunodeficiency virus type 1. No cytotoxicity
of these products was noted against host cells at the 50% cytotoxic concentration of 100 μg/ml, except that naturally occurring
sulfated polysaccharide had 50% cytotoxicity against MT-4 cells at 8–21 μg/ml.
Received May 1, 1998; accepted July 24, 1998. 相似文献
2.
Wei SP Li XQ Chou CF Liang YY Peng JB Warnock DG Ma HP 《The Journal of membrane biology》2007,220(1-3):21-31
We used patch-clamp techniques and A6 distal nephron cells as a model to determine how cholesterol regulates the renal epithelial
sodium channel (ENaC). We found that luminal methyl-β-cyclodextrin (mβCD, a cholesterol scavenger) did not acutely affect
ENaC activity at a previously used concentration of 10 mm but significantly decreased ENaC activity both when the cell membrane was stretched and at a higher concentration of 50 mm. Luminal cholesterol had no effect on ENaC activity at a concentration of 50 μg/ml but significantly increased ENaC activity
both when the cell membrane was stretched and at a higher concentration of 200 μg/ml. Confocal microscopy data indicate that
membrane tension facilitates both mβCD extraction of cholesterol and A6 cell uptake of exogenous cholesterol. Together with
previous findings that cholesterol in the apical membrane is tightly packed with sphingolipids and that stretch can affect
lipid distribution, our data suggest that membrane tension modulates the effects of mβCD and cholesterol on ENaC activity,
probably by facilitating both extraction and enrichment of apical cholesterol. 相似文献
3.
Xiu-ying Pu Jian-ping Liang Xue-hong Wang Tao Xu Lan-ying Hua Ruo-feng Shang Yu Liu Yan-mei Xing 《中国病毒学》2009,24(1):19-27
To study the antiviral effect of Hypericum perforatum L. extract (HPE) on influenza A virus (IAV) (H1N1) in vitro and in vivo. Cytopathic effect (CPE) and neutral red (NR) dye uptake were used to examine the antiviral effect of HPE on Madin Darby
Canine Kidney (MDCK) cells which were infected with IAV in vitro. HPE was effective against influenza A virus (IAV) in vitro, with a 50% effective concentration (EC50) of 40 μg/mL. The mean 50% cytotoxic concentration (CC50) in the MDCK used in these experiments was 1.5 mg/mL. Ribavirin was run in parallel with EC50 values of 5.0 μg/mL; the mean CC50 for ribavirin was 520 μg/mL. Oral gavage administrations of HPE or ribavirin to mice infected with the IAV were highly effective
in preventing death, slowing the decline of arterial oxygen saturation, inhibiting lung consolidation and reducing lung virus
titers. The minimum effective dose of HPE in these studies was 31.25 mg/kg/day, which was administered twice daily for 5 d
beginning 4 h prior to virus exposure. Below a dosage of 2000 mg/kg/day, almost all treated mice survived, which suggests
that HPE is of low toxicity. Ribavirin’s minimum effective dose was 40 mg/kg/day with the LD50 determined to be 200 mg/kg/day.
Delay of the initiation of either HPE or ribavirin therapy, using approximately 1/3 LD50 dose each time, could still be protective as late as 48 h after exposure to the IAV. While both agents appeared to have similar
efficacy against IAV infections, HPE was considered to be less toxic and may warrant further evaluation as a possible therapy
for influenza.
Foundation items: One Hundred Person Project of The Chinese Academy of Sciences (2008-287); The Project of Basic Scientific
Research Fund for Central Public-Welfare of Institute of Sciences (BRF070402). 相似文献
4.
A tetrameric lectin, with hemagglutinating activity toward rabbit erythrocytes and with specificity toward d-mannosamine and d(+)-mannose, was isolated from the ovaries of a teleost, the cobia Rachycentron canadum. The isolation protocol comprised ion exchange chromatography on CM-cellulose and Q-Sepharose, ion exchange chromatography
by fast protein liquid chromatography (FPLC) on Mono Q, and finally gel filtration by FPLC on Superose 12. The lectin was
adsorbed on all ion exchangers used. It exhibited a molecular mass of 180 kDa in gel filtration on Superose 12 and a single
45-kDa band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicating that it is a tetrameric protein. The
hemagglutinating activity of the lectin was stable up to 40°C and between pH 4 and pH 10. All hemagglutinating activity disappeared
at 60°C and at pH 1 and pH 13. The hemagglutinating activity was doubled in the presence of 0.1 μM FeCl3. The lectin exerted antibacterial activity against Escherichia coli with 50% inhibition at 250 μg. There was no antifungal activity toward Coprinus comatus, Fusarium oxysporum, Mycosphaerella arachidicola, and Rhizoctonia solani at a dose of 300 μg. The lectin exhibited maximal mitogenic response from mouse splenocytes at a concentration of 14 μM. 相似文献
5.
Woo-Jin Shin Kwang-Hee Lee Myung-Hwan Park Baik-Lin Seong 《Microbiology and immunology》2010,54(1):11-19
Influenza virus continues to emerge and re-emerge, posing new threats for humans. Here we tested various Korean medicinal plant extracts for potential antiviral activity against influenza viruses. Among them, an extract of Agrimonia pilosa was shown to be highly effective against all three subtypes of human influenza viruses including H1N1 and H3N2 influenza A subtypes and influenza B virus. The EC50 value against influenza A virus, as tested by the plaque reduction assay on MDCK cells, was 14–23 μg/ml. The extract also exhibited a virucidal effect at a concentration of 160–570 ng/ml against influenza A and B viruses when the viruses were treated with the extract prior to plaque assay. In addition, when tested in embryonated chicken eggs the extract exhibited a strong inhibitory effect in ovo on the H9N2 avian influenza virus at a concentration of 280 ng/ml. Quantitative RT-PCR analysis data showed that the extract, to some degree, suppressed viral RNA synthesis in MDCK cells. HI and inhibition of neuraminidase were observed only at high concentrations of the extract. And yet, the extract's antiviral activity required direct contact between it and the virus, suggesting that its antiviral action is mediated by the viral membrane, but does not involve the two major surface antigens, HA and NA, of the virus. The broad-spectrum antiviral activity of Agrimonia pilosa extract on various subtypes of influenza viruses merits further investigation as it may provide a means of managing avian influenza infections in poultry farms and potential avian-human transmission. 相似文献
6.
Summary Primary and passaged cultures of normal colon epithelial cells, derived from human fetuses (13 to 17 wk of conceptual age)
have been established. These cultures have been passaged 16 times thus far. The cultures have been initiated and maintained
in medium consisting of 50% Dulbecco's minimum essential medium and 50% Ham's F12 medium and supplemented with antibiotics
(penicillin, 100 U/ml; streptomycin, 100 μg/ml); ascorbic acid, 40 μg/ml;l-isoleucine, 50 μg/ml; epidermal growth factor, 20 ng/ml; insulin, 5 μg/ml; cholera toxin, 5 ng/ml; transferrin, 1 μg/ml;
fetal bovine serum (10%); and HEPES, 25 mM final concentration, and incubated at 37°C in humidified gas containing 5% CO2: 95% air.
The cellular and subcellular characteristics of primary and passaged cultures were defined using light microscopy and scanning
and transmission electron microscopy. The cells exhibited microvilli on cell surfaces and showed junctional complexes and
interdigitations between cells. Indented nuclei with dense chromatin and marginated heterochromatin, numerous mitochondria,
rough endoplasmic reticulum, polysomes, and extensive Golgi zones were conspicuous. Also, periodic acid Schiff's reagent-positive
staining of the cells suggests the active synthesis of complex mucopolysaccharides in the cytoplasm.
This study was supported by USPHS Grant CA-30185 from the National Large Bowel Cancer Project, National Cancer Institute. 相似文献
7.
In vitro antifungal activities of voriconazole and reference agents as determined by NCCLS methods: Review of the literature 总被引:15,自引:0,他引:15
Voriconazole (Vfend™) is a new triazole that currently is undergoing phase III clinical trials. This review summarizes the
published data obtained by NCCLS methods on the in vitro antifungal activity of voriconazole in comparison to itraconazole,
amphotericin B, fluconazole, ketoconazole and flucytosine. Voriconazole had fungistatic activity against most yeasts and yeastlike
species (minimum inhibitory concentrations [MICs] <2 μg/ml) that was similar or superior to those of fluconazole, amphotericin
B, and itraconazole. Against Candida glabrata and C. krusei, voriconazole MIC ranges were 0.03 to 8 and 0.01 to >4 μg/ml, respectively. For four of the six Aspergillus spp. evaluated, voriconazole MICs (< 0.03 to 2 μg/ml) were lower than amphotericin B (0.25 to 4 μg/ml) and similar to itraconazole
MICs. Voriconazole fungistatic activity against Fusarium spp. has been variable. Against F. oxysporum and solani, most studies showed MICs ranging from 0.25 to 8 μg/ml. Voriconazole had excellent fungistatic activity against five of the
six species of dimorphic fungi evaluated (MIC90s < 1.0 μg/ml). The exception was Sporothrix schenckii (MIC90s and geometric mean MICs ≥ 8 μg/ml). Only amphotericin B had good fungistatic activity against the Zygomycetes species (voriconazole
MICs ranged from 2 to >32 μg/ml). Voriconazole showed excellent in vitro activity (MICs < 0.03 to 1.0 μg/ml) against most
of the 50 species of dematiaceous fungi tested, but the activity of all the agents was poor against most isolates of Scedosporium prolificans and Phaeoacremonium parasiticum (Phialophora parasitica). Voriconazole had fungicidal activity against most Aspergillus spp., B. dermatitidis, and some dematiaceous fungi. In vitro/in vivo correlations should aid in the interpretation of these results.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
8.
Pei-Wen Hsieh Li-Chi Hsu Chern-Hsiung Lai Chin-Chung Wu Tsong-Long Hwang Yin-Ku Lin Yang-Chang Wu 《World journal of microbiology & biotechnology》2009,25(8):1461-1469
The endophytic extracts from 19 endophytes, isolated from 13 species of Taiwanese plants, were evaluated for biological activity,
including cytotoxicity, anti-platelet aggregation, and anti-inflammatory activity. The extracts of 12 endophytes exhibited
inhibitory effects on collagen-induced platelet aggregation with IC50 values of 19.85–87.64 μg/ml. Four strains, Rahnella aquatilis, Pantoea agglomerans, Rhodotorula sp., and Penicillium paxilli, also showed inhibitory effects on thrombin-induced platelet aggregation with IC50 values of 42.80–61.54 μg/ml. Additionally 12 extracts of endophytes exhibited cytotoxicities with IC50 values of 0.12–19.83 μg/ml. However, eight extracts revealed inhibitory effects on superoxide anion generation induced by
fMLP (N-formyl-l-methionyl-l-leucyl-l-phenylalanine) in human neutrophils. The extract of Rahnella aquatilis showed anti-platelet aggregation activity, and bioassay-directed fractionation led to the isolation of six compounds, including
one isoalloxazine: lumichrome (1); two isoflavones: genistein (2) and daidzein (3); two cyclic peptides: cyclo-Pro-Val (4)
and cyclo-Pro-Phe (5); and one benzenoid: methyl 2,4,5-trimethoxybenzoate (6). These results indicated that endophytes from
Taiwanese herbal plants could be useful sources for research and development of bioactive lead compounds from nature. 相似文献
9.
Don J. Brenner Hervé Bercovier Jan Ursing Jean Michel Alonso Arnold G. Steigerwalt G. Richard Fanning Geraldine P. Carter H. H. Mollaret 《Current microbiology》1980,3(4):207-212
The drugs griseofulvin (10 μg/ml), nalidixic acid (0.05 μg/ml), quinine dihydrochloride (50 μg/ml), quinine ethylcarbonate
(50 μg/ml), quinine urea hydrochloride (50 μg/ml), quinine lactate (50 μg/ml), and pamaquine (50 μg/ml) were chosen for laboratory
studies. The minimal inhibitory concentration of the drug was used for determining the range of drug concentration needed
to produce “mutational synergism” with ultraviolet radiation. Forward mutation from streptomycin sensitivity to resistance
was used as a marker for mutagenicity. No stimulatory or inhibitory effects were noted on viable counts and mutation frequency,
when the drugs were added (20–60 μg/ml) to the growth medium of unirradiatedEscherichia coli HCR+, HCR−, and irradiated HCR− strains. These drugs increased mutation frequency and lethality of irradiated HCR+ bacteria. Incorporation of adenine (6 μm) into the minimal expression medium reverses the mutagenic effect of chloroquine.
Chloroquine (50 μg/ml) did not interfere with the photoactivation of irradiated HCR+ cells. Our findings suggest that these chemicals selectively interfere with excision-repair. 相似文献
10.
An N-acetyl-d-lactosamine (LacNAc) specific lectin from tubers of Alocasia cucullata was purified by affinity chromatography on asialofetuin-linked amino activated silica. The pure lectin showed a single band
in SDS-PAGE at pH 8.8 and was a homotetramer with a subunit molecular mass of 13.5 kDa and native molecular mass of 53 kDa.
It was heat stable up to 55 °C for 15 min and showed optimum hemagglutination activity from pH 2 to 11. The lectin was affected
by denaturing agents such as urea (2 m), thiourea (2 m) and guanidine–HCl (0.5 m) and did not require Ca2+ and Mn2+ for its activity. It was a potent mitogen at 10 μg/ml towards human peripheral blood mononuclear cells with 50% growth inhibitory
potential towards SiHa (human cervix ) cancer cell line at 100 μg/ml. 相似文献
11.
Su-A Lee Seong-Karp Hong Chang-Il Suh Mi-Hwa Oh Jeong-Ho Park Byoung-Wook Choi Seung-Won Park Soon-Young Paik 《Journal of microbiology (Seoul, Korea)》2010,48(2):249-252
The anti-HIV-1 activities of butanol, hexane, chloroform and water extracts from four widely used folk medicinal plants (Sophora flavescens, Tulipa edulis, Herba ephedra, and Pachyma hoelen Rumph) were evaluated in this study. The hexane extract of Pachyma hoelen Rumph, PH-4, showed effective inhibition against HIV-1. The 50% effective concentration (EC50) of PH-4 was 37.3 μg/ml in the p24 antigen assay and 36.8% in the HIV-1 recombinant RT activity test (at 200 μg/ml). In addition,
the PH-4 showed the protective effect on the infected MT-4 cells, with a 58.2% rate of protection. The 50% cytotoxic concentration
(CC50) of PH-4 was 100.6 μg/ml. These results suggest that PH-4 from Pachyma hoelen Rumph might be the candidate for the chemotherapy agent against HIV-1 infection with further study. 相似文献
12.
N. V. Galayko I. A. Tolmacheva V. V. Grishko L. V. Volkova E. N. Perevozchikova S. A. Pestereva 《Russian Journal of Bioorganic Chemistry》2010,36(4):516-521
Novel hydrazones of the lupane and 19β,28-epoxy-18α-oleanane types have been synthesized via the interaction of 2,3-secotriterpenic
aldehydonitriles with substituted hydrazines. As a result of the investigation of the antiviral activity of 2,3-secotriterpenic
hydrazones against the Indiana strain of the vesicular stomatitis virus on two models of mammalian cell line infection, the
acetylhydrazone of 1-cyano-2,3-seco-19β,28-epoxy-18α-olean-3-al has been found to have a high prophylactic activity of 0.00016
μg/ml to the vesicular stomatitis virus and to inhibit virus reproduction in primarily infected cells in a 0.21-μg/ml concentration. 相似文献
13.
Kiyohara H Ichino C Kawamura Y Nagai T Sato N Yamada H Salama MM Abdel-Sattar E 《Phytomedicine》2012,19(2):111-114
Methanolic extracts of six Saudi plants were screened for their in vitro antiviral activity using influenza virus A/PR/8/34 (H1N1) and MDCK cells in an MTT assay. The results indicated that the extracts of Adeniumobesum and Tephorosianubica possessed antiviral activity (99.3 and 93.3% inhibition at the concentration of 10 μg/ml, respectively). Based on these results A. obesum was selected for further study by applying bioactivity-guided fractionation to isolate its antiviral principle. The antiviral principle was isolated from the chloroform fraction through solvent fractionation, combined open liquid chromatography and HPLC. The isolated active compound A was identified as oleandrigenin-β-d-glucosyl (1 → 4)-β-d-digitalose, on the basis of its spectral analysis (MS, 1D and 2D NMR). The isolated glycoside showed reduction of virus titre by 69.3% inhibition at concentration of 1 μg/ml (IC50 = 0.86 μg/ml). 相似文献
14.
Kanwar SS Lumba K Gupta SK Katoch VM Singh P Mishra AK Kalia SB 《Biotechnology letters》2008,30(4):677-680
An isonicotinoyldithiocarbazic acid (IN-DtczH) ligand, synthesized from isoniazid, was complexed with transition metals and
evaluated for anti-mycobacterial activity as well as toxicity towards human-transformed rhabdomyosarcoma (RD) cells in vitro.
Complexes with Ni, Co and Zn showed MIC of 2, 2 and 50 μg/ml against Mycobacterium
tuberculosis H37Rv, and 10, 100 and 50 μg/ml against a multidrug-resistant strain of M. tuberculosis. They had little cytotoxic effect on the RD cells. In contrast, the Cu complex was highly cytotoxic with a low anti-mycobacterial
activity. 相似文献
15.
We compared the effects of four quaternary benzo[c]phenanthridine alkaloids – chelerythrine, chelilutine, sanguinarine, and sanguilutine – and two quaternary protoberberine
alkaloids – berberine and coptisine – on the human cell line HeLa (cervix carcinoma cells) and the yeastsSaccharomyces cerevisiae andSchizosaccharomyces japonicus var. versatilis. The ability of alkaloids to display primary fluorescence, allowed us to record their dynamics and localization in cells.
Cytotoxic, anti-microtubular, and anti-actin effects in living cells were studied. In the yeasts, neither microtubules nor
cell growth was seriously affected even at the alkaloid concentration of 100 μg/ml. The HeLa cells, however, responded to
the toxic effect of alkaloids at concentrations ranging from 1 to 50 μg/ml. IC50 values for individual alkaloids were: sanguinarine IC50 = 0.8 μg/ml, sanguilutine IC50 = 8.3 μg/ml, chelerythrine IC50 = 6.2 μg/ml, chelilutine IC50 = 5.2 μg/ml, coptisine IC50 = 2.6 μg/ml and berberine IC50 >10.0 μg/ml. In living cells, sanguinarine produced a decrease in microtubule numbers, particularly at the cell periphery,
at a concentration of 0.1 μg/ml. The other alkaloids showed a similar effect but at higher concentrations (5–50 μg/ml). The
strongest effects of sanguinarine were explained as a consequence of its easy penetration through the cell membrane owing
to nonpolar pseudobase formation and to a high degree of molecular planarity.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
16.
These studies were designated to investigate the effect of chlortetracycline on sedimentation properties of polysomes and
ribosomes present in the chlortetracycline producing strain ofStreptomyces aureofaciens. In presence of chlortetracycline polysomes and ribosomes are more stable than the bacterial ones. At lower chlortetracycline
concentrations (1–5 μg/ml) dissociation of polysomes into 70 S monomers was not observed. Ribosomes in higher concentration
of chlortetracycline (400 μg/ml) form aggregates. A decrease of Mg2+ to 0.1mm caused dissociation of ribosomes to two subunits and in this state none of indicated concentrations of chlortetracycline
caused aggregation. The exact sedimentation values of ribosomes and ribosomal subunits were calculated from extrapolation
to infinite dilution. S20,w for monomer form was 68.8, and for ribosomal subunits 49.8 and 31.2 respectively. Ribosomal RNA sedimentates as two Schlieren
peaks of 16 S and 22 S. It was found that 30 S subunits contain 15 structural proteins, while 21 proteins were resolved from
50 S subunits. 相似文献
17.
Linezolid is an oxazolidinone compound that has been shown to have impressive antimicrobial activity against a number of Gram-positive
bacteria. It inhibits an initiation step of protein synthesis, and its binding site has been shown to be on the 50S ribosomal
subunit. Linezolid was tested to see whether would interfere with the formation of the 50S subunit in Staphylococcus aureus cells, since a number of other 50S-specific antibiotics have this second inhibitory function. Linezolid inhibited protein
synthesis in S. aureus cells with an IC50 of 0.3 μg/ml. A concentration-dependent decline in cell number with an increase in generation time was found. Pulse-chase
labeling studies revealed a specific inhibitory effect on 50S particle formation, with no effect on 30S subunit assembly.
The compound inhibited 50S synthesis with an IC50 of 0.6 μg/ ml, indicating an equivalent effect on translation and particle assembly. A postantibiotic effect of 1 h was found
when cells were initially treated with the drug at 2 μg/ ml. 50S particle numbers recovered more rapidly than translational
capacity, consistent with the increase in viable cell numbers. The inhibitory activities of this novel antimicrobial agent
in cells are discussed.
Received: 28 June 2001 / Accepted: 27 August 2001 相似文献
18.
In vitro activity of a new triazole antifungal agent,Sch 56592, against clinical isolates of filamentous fungi 总被引:6,自引:0,他引:6
Sch 56592 is a new triazole derivative that possesses potent, broad-spectrum antifungal activity. We evaluated the in vitroactivity
of Sch 56592 compared with that of itraconazole, amphotericin B and 5-fluorocytosine against 51 clinical isolates of filamentous
fungi, including Aspergillus flavus(10), A. fumigatus(12), Fusariumspp. (13), Rhizopus spp. (6), Pseudallescheria boydii(5),
and one isolate each of Acremoniumspp., A. niger, A. terreus, Paecilomycesspp., and Trichodermaspp. In vitrosusceptibility
testing was performed using the microdilution broth method outlined in the NCCLS 27-A document. Sch 56592 was highly active
against A. flavus(MIC90, 0.25 μg/ml), A. fumigatus(MIC90, 0.12 μg/ml), P. boydii(MIC50, 1 μ/ml) and Rhizopusspp (M1C50, 1 μg/ml). By comparison with itraconazole, Sch 56592 was four- to eight-fold more active against isolates of Aspergillusand
both compounds showed equipotent in vitroactivity against P. boydiiand Rhizopusspp. Sch 56592 was four- to 16-fold more active
than amphotericin B against Aspergillusspp. and P. boydiiand both antifungal drugs displayed similar activity against Rhizopusspp.
Overall, Sch 56592 showed good in vitroactivity against all isolates tested (MIC, ≤ 2 μg/ml) except isolates of Fusarium(MIC
range, 1–>4 μg/ml). On the basis of these data Sch 56592 has promising activity against Aspergillus spp. and other species
of filamentous fungi that are likely to be encountered clinically. Additional in vitroand in vivostudies are warranted.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
19.
Terry L. Riss Kenneth P. Karey B. Daniel Burleigh David Farker David A. Sirbasku 《In vitro cellular & developmental biology. Plant》1988,24(11):1099-1106
Summary A serum-free clonal density growth assay was developed for the quantification of the biological activity of human recombinant
insulin-like growth factor I (IGF-I). The assay measures IGF-I stimulated growth of Balb/c 3T3 cells cultured over 4 d on
poly-d-lysine-coated plastic surfaces in a serum-free medium formulation composed of a 1∶1 (vol/vol) mixture of Ham's F12 and Dulbecco's
modified Eagle's media, supplemented with 3.0 ng/ml bovine basic fibroblast growth factor (bFGF), 10 μg/ml human transferrin,
100 μg/ml ovalbumin, and 1.0 μM dexamethanose. Low-temperature trypsinization of serum-supplemented stock cultures combined with the use of poly-d-lysine-coated plates made it unnecessary to use serum or fibronectin to promote cell attachment and survival. Serum-free
growth conditions were optimized with respect to the concentrations of the supplements. Addition of IGF-I resulted in 3.5-fold
more cells than control cultures without IGF-I after 4 d. Deletion of bFGF resulted in no IGF-I stimulation of growth. The
concentrations of various preparations of IGF-I required to achieve one-half maximal stimulation of cell number (ED50), ranged between 1.25 and 4.7 ng/ml. In parallel assays, IGF-I was 6.6 times more potent than human recombinant insulin-like
growth factor II and 32 times more potent than insulin. When cells were seeded into medium containing IGF-I, transferrin,
ovalbumin, and dexamethasone but no bFGF, growth was minimal. Dose-response addition of bFGF showed an ED50, of 0.9 ng/ml. The methods reported are useful to monitor the biological potency of recombinant and natural-source growth
factors as well as providing a new means of studying the multiple growth factor requirements of Balb/c 3T3 cells in cultures.
This work was supported by a contract from IMCERA Bioproducts, Inc. 相似文献
20.
E. I. Isaeva N. A. Mazurkova M. O. Skarnovich G. P. Troshkova L. N. Shishkina R. Ya. Podchernyayeva 《Applied Biochemistry and Microbiology》2011,47(8):737-743
Roller culturing of MDCK and Vero cells in an experimental nutrient medium based on soy flour hydrolysate, plant material
obtained using the bromelain plant enzyme, was studied. The medium supplemented with 2 or 3% fetal calf serum (FCS) had a
strong growth-stimulating effect on Vero and MDCK and cells, respectively, and did not alter the cell morphology. A/Solomon
Islands/03/06 (H1N1) and B/Malaysia/2506/04 influenza vaccine viruses were grown on MDCK and Vero cell cultures obtained as
a result of culturing in rollers on media containing soy flour hydrolysate and FCS (2 or 3%, respectively). The titer of the
viruses was high in the presence of either trypsin (2 μg/ml) or bromelain (20 μg/ml). 相似文献