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1.
Objective: This study examined whether, daily fruit (blueberries) consumption (250 g) for three weeks or acute fruit ingestion (250 g) would attenuate angiotensin converting enzyme (ACE) activity and reduce oxidative stress in chronic cigarette smokers.

Methods: Twenty subjects were recruited and randomized into fruit or control groups. Blood samples and blood pressure were obtained at baseline and then pre and one hour post when subjects returned to the lab three weeks later. To examine acute effects, the fruit group immediately ingested 250 g of blueberries after returning and at least one hour prior to the post blood draw. Plasma samples were analyzed for ACE activity, F2- isoprostanes and lipid hydroperoxides (LH) as measures of oxidative stress, and ferric reducing ability of plasma (FRAP) as a measure of antioxidant potential. A 2 (treatment) × 3 (time) repeated measures ANOVA was used for statistical analysis. If interaction was significant, then Student's t-tests were used to further examine this relationship. For these comparisons, a Bonferroni adjustment was made with statistical significance set at P < 0.025.

Results: The pattern of change between treatments was not significant for any variable except LH (P < 0.001).

Conclusion: This study indicates that LH are significantly reduced by daily fruit consumption, but not affected by acute ingestion. This finding could be one way in which fruit consumption contributes to prevention of cardiovascular disease.  相似文献   

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International Journal of Peptide Research and Therapeutics - Bone defect diseases, particularly those induced by inflammation, pose a challenge for the design of ideal drug-loading scaffolds that...  相似文献   

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Three-dimensional (3D) cell culture techniques using a bioreactor have been used to co-culture various breast cancer cell lines. Comparisons between 3D co-cultures containing different proportions of breast cancer cell lines have been made with respect to cluster size, cell surface marker distribution, and Ki67 expression. Furthermore, an observed difference in invasion through collagen between co-cultures has been briefly reported. However, these assays have not yet been developed into a quantifiable methodology to assess the effects of drugs and/or microenvironments on cellular invasion. From a cancer perspective, two important aspects of cellular invasion that are often left out of in vitro assays are considerations about the 3D structural heterogeneity of the primary tumor and the ability of cells to migrate in all directions. Accordingly, we have taken advantage of the methodology previously described for 3D cell culture techniques and have developed a 3D invasion assay using cell clusters that can be used to assess the effects of different drugs and treatment conditions on cancer cell invasion. We also describe a novel whole-mount technique that permits fluorescence-based immunolocalization of proteins through the entire tumorsphere, without the need for sectioning. Our assay provides a simple, inexpensive, and physiologically relevant context to study cellular invasion in vitro, in a way that recapitulates an in vivo milieu.  相似文献   

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BackgroundThymoquinone is an active ingredient isolated from Nigella sativa (Black Seed). This study aimed to evaluate the in vitro and in vivo anti-leukemic effects of thymoquinone on WEHI-3 cells.ConclusionThymoquinone promoted natural killer cell activities. This compound showed high toxicity against WEHI-3 cell line which was confirmed by an increase of the early apoptosis, followed by up-regulation of the anti-apoptotic protein, Bcl2, and down-regulation of the apoptotic protein, Bax. On the other hand, high reduction of the spleen and liver weight, and significant histopathology study of spleen and liver confirmed that thymoquinone inhibited WEHI-3 growth in the BALB/c mice. Results from this study highlight the potential of thymoquinone to be developed as an anti-leukemic agent.  相似文献   

6.
In Vitro and In Vivo Characterization of Pyocin   总被引:7,自引:3,他引:4       下载免费PDF全文
Pyocin, a bacteriocin obtained from lysates of ultraviolet-induced cultures of Pseudomonas aeruginosa was characterized in vitro and in vivo after 1,000-fold purification by chemical, column, and differential centrifugation procedures. Electron micrographs of negatively stained pyocin preparations contained rod-shaped particles which resembled the contractile tail protein of the T-even phages of Escherichia coli. Although two separate and distinct pyocin fractions were eluted from diethylaminoethyl cellulose (pH 7.5) during the purification procedure, the particles appeared identical. In addition, the two fractions exhibited a close correlation between their titers and the particle numbers as observed in the electron microscope. The particles were approximately 20 by 90 mmu with a core diameter of 5 mmu and a sheath length of 50 mmu. Neither intact phage nor ghosts were seen in any of the preparations, although ringlets of two different diameters, which appeared to correspond to the diameters of the sheath and inner core, were observed. Other studies indicated that, although crude preparations were stable to freezing and thawing, purified preparations lost all of their activity under similar treatment. However, the addition of 50% glycerol to purified preparations completely protected activity. Conversely, aged normal human or rabbit sera enhanced the antibacterial activity of pyocin approximately fourfold, although serum albumin and hemoglobin had no effect. In vivo studies indicated that purified pyocin was not lethal for mice when injected intraperitoneally in concentrations of 28,000 to 1,400,000 units (5.6 to 276 mug of protein), nor was 7,200 to 36,000 units dermonecrotic for rabbits.  相似文献   

7.
The room temperature absorption bandshape for the Q transition region of chlorophyll a is calculated using the vibrational frequency modes and Franck-Condon (FC) factors obtained by line-narrowing spectroscopies of chlorophyll a in a glassy (Rebane and Avarmaa, Chem. Phys. 1982; 68:191-200) and in a native environment (Gillie et al., J. Phys. Chem. 1989; 93:1620-1627) at low temperatures. The calculated bandshapes are compared with the absorption spectra of chlorophyll a measured in two different solvents and with that obtained in vivo by a mutational analysis of a chlorophyll-protein complex. It is demonstrated that the measured distributions of FC factors can account for the absorption bandshape of chlorophyll a in a hexacoordinated state, whereas, when pentacoordinated, reduced FC coupling for vibrational frequencies in the range 540-850 cm−1 occurs. The FC factor distribution for pentacoordinated chlorophyll also describes the native chlorophyll a spectrum but, in this case, either a low-frequency mode (ν < 200 cm−1) must be added or else the 262-cm−1 mode must increase in coupling by about one order of magnitude to describe the skewness of the main absorption bandshape.  相似文献   

8.
14-3-3 proteins complex with many signaling molecules, including the Raf-1 kinase. However, the role of 14-3-3 in regulating Raf-1 activity is unclear. We show here that 14-3-3 is bound to Raf-1 in the cytosol but is totally displaced when Raf-1 is recruited to the plasma membrane by oncogenic mutant Ras, in vitro and in vivo. 14-3-3 is also displaced when Raf-1 is targeted to the plasma membrane. When serum-starved cells are stimulated with epidermal growth factor, some recruitment of 14-3-3 to the plasma membrane is evident, but 14-3-3 recruitment correlates with Raf-1 dissociation and inactivation, not with Raf-1 recruitment. In vivo, overexpression of 14-3-3 potentiates the specific activity of membrane-recruited Raf-1 without stably associating with the plasma membrane. In vitro, Raf-1 must be complexed with 14-3-3 for efficient recruitment and activation by oncogenic Ras. Recombinant 14-3-3 facilitates Raf-1 activation by membranes containing oncogenic Ras but reduces the amount of Raf-1 that associates with the membranes. These data demonstrate that the interaction of 14-3-3 with Raf-1 is permissive for recruitment and activation by Ras, that 14-3-3 is displaced upon membrane recruitment, and that 14-3-3 may recycle Raf-1 to the cytosol. A model that rationalizes many of the apparently discrepant observations on the role of 14-3-3 in Raf-1 activation is proposed.  相似文献   

9.
Regulation of Pyruvate Decarboxylase In Vitro and In Vivo   总被引:2,自引:0,他引:2  
Results presented in this paper strongly support the view thatregulation of the key enzyme of alcoholic fermentation, pyruvatedecarboxylase (PDC), is achieved in a number of ways, all associatedwith possible lowering of the cytoplasmic pH during anoxia.These mechanisms include not only the well-known acid pH optimumof PDC, but also long-term, reversible changes in characteristicsof the enzyme established both in vitro and in vivo. Following transfer of desalted extracts from pH 6.0 to 7.4,maximal activity of PDC was decreased, while there was a considerableincrease in the lag before maximal activity was reached. Similarchanges in enzyme characteristics were observed when wheat (Triticumaestivum L. cv. Gamenya) roots and rice (Oryza sativa L. cv.Calrose) coleoptiles were transferred from anoxic to aerobicsolutions, provided PDC was assayed within 10 min of the startof maceration. All of the above changes were usually readilyreversible when extracts were returned to pH 6.0, or when plantswere returned to anoxic solutions. Additional regulation of PDC would be achieved by the S0.5 forpyruvate which is 0.75 mol m–3 at pH 6.0, 1.0 mol m–3at pH 6.8, and 2.5 mol m–3 at pH 7.4; the latter is wellabove estimates for pyruvate concentrations in the cytoplasmof aerated tissues. We assess that the combined effects of the acid pH optimum,the high S0.5 at pH 7.4 and the long-term decreases in activityobserved during incubation at pH 7.4 would reduce PDC activityin aerobic cells to at most 7% of the activity in anoxic cells.Possible additional controls for the pathway of alcoholic fermentationare briefly considered. Key words: PDC, regulation, anoxia  相似文献   

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The objectives of present study were to investigate whether luteolin affects procoagulant proteinase activity and fibrin clot formation and influences thrombosis and coagulation in Sprague–Dawle rats. Luteolin significantly inhibited the enzymatic activity of thrombin and FXa activity by 29.1% and 16.2%. Luteolin also inhibited fibrin polymer formation in turbidity and microscopic analysis using fluorescent conjugate. Coagulation assay of luteolin was found to prolong activated partial thromboplastin time and prothrombin time. Moreover, luteolin protected the development of oxidative stress induced thrombosis in the FeCl3‐induced carotid arterial thrombus model. This study demonstrated that luteolin may be useful by reducing or preventing thrombotic challenge and can help us better understand the antithrombotic action of luteolin.  相似文献   

13.
A derivative of thiosemicarbazone, γ-thiochromanone-l-thiosemicarbazone (SN-13), which differed from N-methylisatin-β-thiosemicarbazone (marboran) in that the carbonyl group in the C2 position of N-methylisatin was lacking, has been found to possess an anti-vaccinia effect as determined by the pulp disc method of plaque inhibition and by inhibition of cytopathic effect in tube cultures of chick embryo cells as well as by prevention of mouse tail lesions by the vaccinia virus. In tube cultures, SN-13 was shown to be effective even when the treatment was started as late as 8 hr after virus infection, whereas no activity was observed with marboran when started from the 8th hr. SN-13 was as effective as marboran on cross treatments of vaccinia virus with the two compounds in tube cultures, either by treatment at an early or a late stage of the virus growth. Moreover, the inhibitory effect of SN-13 on vaccinia virus growth was completely reversed by actinomycin D similar to that observed with marboran in tube cultures. No additive effect of the two compounds was observed in animal tests.  相似文献   

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In Vivo and In Vitro Action of Norethindrone on Staphylococci   总被引:5,自引:0,他引:5       下载免费PDF全文
Norethindrone has been examined in vitro for antibacterial activity against 10 microorganisms. Turbidimetric techniques were used to assay the antibacterial activity of norethindrone. The organisms tested included Staphylococcus aureus, S. epidermidis, Micrococcus conglomeratus, Listeria monocytogenes, Streptococcus faecalis, Salmonella typhosa, Shigella flexnerii, Klebsiella pneumoniae, Escherichia coli, and Proteus vulgaris. Bacteriostatic action was shown only against the gram-positive microorganisms when they were grown anaerobically in Tryptic Soy Broth containing 10 to 50 mug of norethindrone per ml. The bacteriostatic action of norethindrone was exerted primarily during the first 8 hr of incubation and it was reduced by the presence of oxygen. Mestranol at a concentration of 1 to 10 mug/ml failed to exert any significant action on S. aureus. However, incorporation of 5 mug of mestranol per ml in the culture medium enhanced the bacteriostatic action of norethindrone on staphylococci. Enhancement of the bacteriostatic action of norethindrone could not be obtained by the addition of a concentration of 5 mug/ml of testosterone, 17alpha-estradiol, and 17beta-estradiol. Progesterone and 4-pregnen-20beta-ol-3-one under similar conditions showed an additive bacteriostatic effect when they were incorporated into the culture medium containing norethindrone. In vivo studies indicated that female, adult New Zealand rabbits, injected subcutaneously with two injections of 10 to 20 mug of norethindrone, 24 hr apart, and challenged intradermally with S. aureus 4 hr after the second injection, had fewer lesions with smaller areas of swelling and erythema as compared to control, nontreated rabbits. The protective effect of norethindrone on the development of staphylococcal lesion seemed related to hormone concentration. Thus, it was demonstrated with doses of 20, 15, and 10 mug, but not with doses of 1 and 5 mug. When the lesions were excised 48 to 92 hr after infection and when viable cell counts were made, rabbits treated with norethindrone showed significantly lower staphylococcal counts than the control rabbits. During the 1st day after infection with S. aureus, leukocytic counts of the norethindrone-treated rabbits remained normal, whereas control animals showed elevated leukocytic counts.  相似文献   

17.
Cleavage of Viral Precursor Proteins In Vivo and In Vitro   总被引:26,自引:18,他引:8       下载免费PDF全文
The use of protease inhibitors causes the accumulation of very large polypeptides (polyprotein) in tissue culture cells infected with either poliovirus or echovirus 12. The effectiveness of the inhibitor varies, depending on the cell line chosen. In infected monkey kidney cells, polyprotein is not cleaved when a chymotrypsin inhibitor is added, but in infected HeLa cells a trypsin inhibitor is most effective. Therefore, at least a part of the proteolytic activity is supplied by the host cell. Extracted viral polyprotein can be cleaved in vitro by trypsin or chymotrypsin. As estimated by migration in sodium dodecyl sulfate gels and antigenicity, chymotrypsin cleavage of the poliovirus polyprotein yields fragments which are similar to the in vivo product. The polyprotein is not in soluble form but is attached to a fast-sedimenting, membrane-bound structure. Proteolytic activities in cell extracts were assayed using polyprotein as substrate, and infected and uninfected extracts produced qualitatively dissimilar cleavages.  相似文献   

18.
Streptomycin-dependent cholera vibrio strains were derived from Inaba, Ogawa, and NAG vibrios by the method of Mel. These phenotypes grew more slowly and attacked fermentable substances after a longer period of time than the streptomycin-sensitive parent strains. Rabbits injected with streptomycin-sensitive strains and their streptomycin-dependent forms showed homologous agglutinin production. Patas monkeys fed with 10(9) streptomycin-dependent strains shed them for 1 to 2 days without ill effect, whereas the same number of streptomycin-independent organisms caused disease. The possibility of the application of multiple doses of streptomycin-dependent organisms in oral immunization against cholera was considered.  相似文献   

19.
Phosphorylation of Vesicular Stomatitis Virus In Vivo and In Vitro   总被引:20,自引:16,他引:4  
The structural protein, NS, of purified vesicular stomatitis virus (VSV) is a phosphoprotein. In infected cells phosphorylated NS is found both free in the cytoplasm and as part of the viral ribonucleoprotein (RNP) complex containing both the 42S RNA and the structural proteins L, N, and NS, indicating that phosphorylation occurs as an early event in viral maturation. VSV contains an endogenous protein kinase activity, probably of host region, which catalyzes the in vitro phosphorylation of the viral proteins NS, M, and L, but not of N or G. The phosphorylated sites on NS appear to be different in the in vivo and in vitro reactions, and are differentially sensitive to alkaline phosphatase. After removal of the membrane components of purified VSV with a dextran-polyethylene glycol two-phase separation, the kinase activity remains tightly associated with the viral RNP. However, viral RNP isolated from infected cells shows only a small amount of kinase activity. The protein kinase enzyme appears to be a cellular contaminant of purified VSV because an activity from the uninfected cell extract can phosphorylate in vitro the dissociated viral proteins NS and M. The virion-associated activity may be derived either from the cytoplasm or the plasma membrane of the host cell since both of these cellular components contain protein kinase activity similar to that found in purified VSV.  相似文献   

20.
Previous studies have shown that β-glucans extracted from yeast or fungi potentiate immune responses. In the present study, the immunomodulatory activities of β-(1→3, 1→4)-glucan, derived from oats, were investigated. The ability of oat β-glucan (OβG) to stimulate IL-1 and TNF-α release from murine peritoneal macrophages and the murine macrophage cell line P338D1, was assessed. In vitro stimulation of macrophages with OβG resulted in the production of IL-1 in a dose and time-dependent manner, whereas only small amounts of TNF-α could be detected in the culture supernatants. OβG also induced the production of IL-2, IFN-γ and IL-4 secretion in a dose-dependent manner in cultured spleen cells. The intraperitoneal administration of OβG in mice resulted in the accumulation of leucocytes, predominantly macrophages, in the peritoneal cavity. Furthermore, OβG was tested for its ability to enhance non-specific resistance to a bacterial challenge in mice. Survival of mice challenged with Staphylococcus aureus was enhanced by a single intraperitoneal administration of 500 μg of OβG 3 days prior to bacterial challenge. In conclusion, these studies demonstrated that OβG possesses immunomodulatory activities capable of stimulating immune functions both in vitro and in vivo.  相似文献   

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