首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
It has previously been shown in our laboratory that the hypocalcemic substances purified from the thymus have a potent lymphocyte-increasing action in mice. Then, lymphocyte-increasing activity was examined with bovine parotid gland extracts, which showed a hypocalcemic activity as potent as that of the thymus extracts. The lymphocyte-increasing activity was assayed in the littermates of neonatal mice of Swiss-Webster strain; the materials used for this experiment were purified preparations and several fractions obtained from the parotid gland extracts in the course of purification. It was found that the potency of lymphocyte-increasing activity rose approximately in parallel with the rise in hypocalcemic activity with progress in purification. The final product, which was purified from the gland by isoelectric precipitation at pH 5.4, fractional precipitation with ammonium sulfate, chromatography on DEAE-cellulose, gel filtration on Sepharose 6B and preparative disc electrophoresis, gave a single band in polyacrylamide gel electrophoresis. Its intravenous injection in rabbits, in a dose of 10 mug/kg, produced a significant lowering in serum calcium (percent decrease 10.24 +/- 1.06%) compared with control animals given an injection of physiological saline. Intraperitoneal injection of this purified product, in a dose of 0.5 mug/mouse, in the littermates of neonatal mice, also produced a significant increase (ratio of lymphocytes to polymorphs 2.47 +/- 0.07) in lymphocytes compared with control animals injected with physiological saline (L/P ratio 1.57 +/- 0.05). These facts suggest that this purified protein fraction inherently contains both activities, but the possibility cannot be ruled out of slight contamination by a substance having a high activity. On the other hand, a fraction having no activity for lowering serum calcium but which had activity for increasing the lymphocytes was obtained. This is the first paper to report the presence of lymphocyte-increasing substances in the bovine parotid gland and the purification of one of the substances from the gland.  相似文献   

2.
A leukocytosis-promoting substance was purified from a crude bovine parotid gland extract. The purified substance was proved to be a single component by polyacrylamide gel disc electrophoresis. It stimulates an increase of peripheral leukocyte numbers in rabbits. The molecular weight of the physiologically active component was estimated to be 4.5 · 104, and the component was found by sodium dodecyl sulfate polyacrylamide gel electrophoresis to be dissociated into two subcomponents.  相似文献   

3.
A leukocytosis-promoting substance was purified from a crude bovine parotid gland extract. The purified substance was proved to be a single component by polyacrylamide gel disc electrophoresis. It stimulates an increase of peripheral leukocyte numbers in rabbits. The molecular weight of the physiologically active component was estimated to be 4.5 . 10(4), and the component was found by sodium dodecyl sulfate polyacrylamide gel electrophoresis to be dissociated into two subcomponents.  相似文献   

4.
In regard to the undecided immunological role of protein polysaccharides (of the glycosaminoglycan type) for pathogenesis of connective tissue diseases a protein polysaccharide-containing extract from bovine nasal cartilage was tested by the absorption method, precipitation and immunization. An A-like effect of the extract was found.  相似文献   

5.
Bovine t hymic peptide extract (1–100 g/ml) is shown to completely inhibit the binding of [125I]VIP to rat blood mononuclear cells, lymphoid cells of spleen, and liver plasma membranes. In the three models, the bovine thymic peptide extract inhibits [125I]VIP binding with a potency that is 4000–7000 times lower than that of the native VIP, on a weight basis. In rat liver plasma membranes, the bovine thymic peptide extract stimulates adenylate cyclase with a maximal efficiency that is similar to that of VIP. At maximal doses, VIP and thymic peptide extract do not exert an additive effect on adenylate cyclase, suggesting that the activation of the enzyme by the bovine thymic peptide extract occurs through VIP receptors. Finally, no VIP-like immunoreactivity was detected in the thymic peptide extract using an antiserum raised against mammalian VIP. All these data suggest the presence in the bovine thymic peptide extract of a new substance which behaves as a VIP agonist in rat.  相似文献   

6.
An extract of bovine sublingual glands (SLF3) reduced the serum cholesterol levels of normal rabbits 34.6% and serum triglyceride levels 19.6% when injected intraperitoneally (i.p.) at 20 mg/kg body wt on alternate days for 7 days. SLF3 also reduced serum cholesterol levels 69.0% and triglyceride levels 46.5% in hypercholesterolemic rabbits, while in similar rabbits injected with a control muscle tissue extract, the rate of decrease in serum cholesterol levels was 33.3% and triglyceride levels 26.7%.  相似文献   

7.
BACKGROUND: Bovine dialyzable leukocyte extract (bDLE) is a dialyzate of a heterogeneous mixture of low molecular weight substances released from disintegrated blood leukocytes or lymphoid tissue obtained from homogenized bovine spleen. The purpose of this study was to determine if bDLE had cytotoxic effects and modulated apoptosis gene expression in breast cancer cells. METHODS: The MCF-7, BT-474, MDA-MB-453, A-427, Calu-1, U937 and L5178Y cancer cell lines and PBMC human cells were treated with bDLE (0-0.66 U/mL) for 72 h. The bDLE effect on cell growth proliferation was evaluated by MTT assay, and the MCF-7 was evaluated by ethidium bromide-acridine orange staining; total DNA was evaluated for DNA fragmentation, and total RNA was isolated for p53, bag-1, c-myc, bim, bax, bcl-2 and bad mRNA expression. RESULTS: The bDLE had dose-dependent cytotoxic effects and demonstrated an IC50 at a dosage of 0.06 U/mL (P<0.05). The bDLE did not affect the viability of normal human PBMC. The bDLE induced DNA fragmentation at doses of 0.06 and 0.13 U/mL in MCF-7 breast cancer cells. The bDLE induced cytotoxic effects and suppressed the p53, bag-1, c-myc, bax, bcl-2, and bad mRNA expression that influences apoptosis in MCF-7 breast cancer cells. Bim mRNA expression was not detected. DISCUSSION: This may open up interesting prospects for the treatment of human breast cancer.  相似文献   

8.
In vitro cultivation of primary bovine knee chondrocytes (BKCs), using bovine pituitary extract (BPE) and porous scaffolds composed of polyglycolide (PGA) and 85/15 poly(lactide-co-glycolide) (PLGA), was investigated. Here, BPE was prepared from fresh bovine pituitaries, and cylindrical PGA/PLGA scaffolds with various chemical compositions were fabricated by solvent merging/particulate leaching method. Experimental results showed that in microcarrier systems, the rate of BKC growth on PGA surfaces is faster than that on PLGA surfaces, and the decrease in the medium pH value of BKCs-adsorbed PGA particles is faster than that of BKCs-adsorbed PLGA particles. After 28-day construct cultivation, the BKC amount and the content of glycosaminoglycans and collagen per construct increased with BPE protein concentration. For a constant BPE protein concentration, a higher PGA percentage in scaffold leads to a better biological environment for the growth of BKCs and the synthesis of extracellar matrices.  相似文献   

9.
10.
In this work four cationic additives were used to improve the surface activity of lung surfactants, particularly in the presence of bovine serum that was used as a model surfactant inhibitor. Two of those additives were chitosan in its soluble hydrochloride form with average molecular weights of 113 kDa and 213 kDa. The other two additives were cationic peptides, polylysine 50 kDa and polymyxin B. These additives were added to bovine lipid extract surfactant (BLES) and the optimal additive-surfactant ratio was determined based on the minimum surface tension upon dynamic compression, carried out in a constrained sessile drop (CSD) device in the presence of 50 μl/ml serum. At the optimal ratio all the BLES-additive mixtures were able to achieve desirable minimum surface tensions. The optimal additive-surfactant ratios for the chitosan chlorides are consistent with a previously proposed patch model for the binding of the anionic lipids in BLES to the positive charges in chitosan. For the peptides, the optimal binding ratios were consistent with ratios established previously for the binding of these peptides to monolayers of anionic lipids. The optimal formulation containing these peptides were able to reach low minimum surface tension in systems containing 500 μl/ml of serum, matching the effectiveness of a lung surfactant extract that had not undergone post-separation processes and therefore contained all its proteins and lipids (complete lung surfactant).  相似文献   

11.
12.
The toxicity of iv injected hydrophilic aluminum complex tris(maltolate)aluminum(III) was studied in New Zealand white rabbits for a period of time ranging from 5 to 63 wk. Animals were injected 3–5 times a week with 1 mL of 7.5 mM Al(malt)3 and one rabbit with a dose 10 times higher after 14 wk of treatment. Autopical examination was performed on all animals. Chemoclinical analysis (glucose, urea, creatinine, cholesterol, bilirubin, alanin aminotransferase, aspartate aminotransferase, alkaline phosphatase, γ-glutamyltransferase, LDH, CK, total protein, triglycerides, and Ca2+) gave no variation in treated animals with respect to the control. The toxicological data show a moderate systemic general toxicity at doses far higher than those used in similar previous experiments using Al(acac)3 (acac=2,4 pentanedionate), a hydrolytically stable and more lipophilic aluminum(III) complex (1). The diversity of behavior is discussed in terms of metal speciation as well as respect to the thermodynamic and kinetic properties of the two complexes in aqueous solution. The toxicological model presented here emphasizes that neutral, water compatible aluminum(III) complexes are to be considered as promising tools for toxicological experiments providing biological models of human pathologies.  相似文献   

13.
1. The present study demonstrated that the Ca(2+)-ATPase activity of the plasma membrane-rich fraction from bovine parotid gland was decreased by the addition of reducing agents. 2. Ca(2+)-ATPase activity staining on SDS-PAGE gels was lost in the presence of 2-mercaptoethanol. 3. Among all the reducing agents tested, GSH was the most effective in inhibiting Ca(2+)-ATPase. 4. The Ca(2+)-ATPase activity decreased by the GSH was restored by the addition of an oxidizing reagent. However, oxidation with an oxidizing reagent subsequent to alkylation of the reduced enzyme with iodoacetamide resulted in no restoration of activity. 5. The decrease of Ca(2+)-ATPase activity by GSH is due to a decrease in the Vmax of the enzyme. 6. These results suggest that the disulfide bond in this enzyme protein is necessary to maintain the activity of this enzyme.  相似文献   

14.
We have shown previously that fresh garlic extract is effective in reducing thromboxane formation by platelets both in vivo and in vitro animal models of thrombosis. In the present study, the effect of different concentrations of a single dose of aqueous extracts of garlic and onion were evaluated on serum thromboxane-B(2)synthesis in rabbits. Different concentrations of garlic and onion were administered as single doses in the ear vein of rabbits. Rabbits were bled before and at different intervals after the infusion of garlic or onion extracts. Venous blood was collected and allowed to clot at 37 degrees C for 1 h. Thromboxane-B(2)level was measured in the serum by radioimmunoassay. It was observed that garlic inhibits the thrombin-induced platelet synthesis of TXB(2)in a dose-and time-dependent manner. Maximum inhibition of TXB(2)occurred between 0.5 h and 6 h at 25 and 100 mg kg(-1)garlic. At 24 h post-garlic infusion TXB(2)inhibition was reduced to 15% of the control and TXB(2)levels were comparable to that of the control values at 72 h pots-garlic infusion. Infusion of 100 mg kg(-1)onion extract did not elicit any inhibitory effect on TXB(2)synthesis in the serum of rabbit during the treatment period. The rapid recovery of platelet cyclooxygenase activity after infusion of a single dose of garlic suggests that garlic should be taken more frequently in order to achieve beneficial effects in the prevention of thrombosis.  相似文献   

15.
Cultured bovine lens epithelial cells are polygonal in shape. In confluent and multilayer cultures they exhibit elaborate arrays of 6 nm filaments, bundles of intermediate-sized filaments, and a fibrous meshwork of subcellular and intercellular material. Cells grown in the presence of a retinal extract (RE) have a higher growth rate, and are smaller and more regular in shape. In them the 6 nm filaments are mostly aligned in sheets, the intermediate-sized filaments form a fine network, and the cells are closely apposed to the plastic substratum. Some homogeneous material is formed intercellularly in older cultures. Cellular elongation, induced in the former cultures by the addition of RE, is accompanied by an alignment of cytoskeletal elements, including microtubules, parallel to the long axis. Other structural features are similar in all cell types. The response to RE is discussed in terms of shape modulations associated with the restricted expression of structural characteristics acquired in vitro.  相似文献   

16.
The study of human lipoprotein (a) [Lp(a)] has been hampered due to the lack of appropriate animal models since apolipoprotein (a) [apo(a)] is found only in primates and humans. In addition, human apo(a) in transgenic mice can not bind to murine apoB to form Lp(a) particles. In this study, we generated three independent transgenic rabbits expressing human apo(a) in their plasma at 1.8-4.5 mg/dl. In the plasma of transgenic rabbits, unlike the plasma of transgenic mice, about 80% of the apo(a) was covalently associated with rabbit apo-B and was contained in the fractions with density 1.02-1.10 g/ml, indicating the formation of Lp(a). These results suggest that transgenic rabbits expressing human apo(a) exhibit efficient assembly of Lp(a) and can be used as an animal model for the study of human Lp(a).  相似文献   

17.
18.
19.
20.
The selective action of two fractions of PCO (a yeast extract) on normal and malignant cells was demonstrated. In vivo, the mitotic activity of malignant cells was inhibited by the methanol-insoluble fraction of PCO, whereas the methanol-soluble fraction caused no inhibition. The in vitro studies, however, showed inhibition of mitoses with both fractions. The malignant cells employed in vitro and in vivo were the Krebs-2 and Ehrlich carcinomas. The nonneoplastic cells tested in vitro were established cultures of epithelial-like cells from murine bone marrow and thymus, and corneal epithelium and peripheral blood in vivo.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号