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11.
A versatile and simple continuous-culture apparatus is described. With this apparatus, independent control of limiting growth factors and other nutrilites is possible and the conditions of each experiment are reproducible. In view of the synchronized speed of the feeder syringes, flow variation troubles are not encountered. The device allows the performance of growth experiments at different dilution rates simultaneously in a single run which makes the comparison of the results more reliable. The operation of the device has been tested successfully with a study of adenine deaminase induction in yeast. 相似文献
12.
Summary Petiolar felt-sheath of palm (Livistona chinensis) has been successfully used as a new biostructural matrix for the immobilization of fungal hyphae. The reticulated felt-sheath is made up of fibrous bundles having irregularly scattered membranous-foliose and fibrous outgrowths woven into a cohesive multi-layered mesh. Immobilization of Aspergillus niger was achieved with both spore and hyphal suspensions as the inoculum. Growth in immobilized cultures was 19% greater than in free cultures. 相似文献
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14.
Bacteriophage MB78, a virulent phage ofSalmonella typhimurium cannot grow in rifampicin-resistant mutant (rif-39) of the host having altered RNA polymerase. The temperate phage P22 which
cannot multiply in presence of the virulent phage MB78 can, however, help MB78 to overcome replication inhibition in rif-39.
The processing of concatemeric phage DNA to monomer is blocked in this nonpermissive host. Superinfection with P22 induces
synthesis of at least five P22 specific polypeptides which help phage MB78 in the processing of the concatemeric DNA and maturation
of phage particles. 相似文献
15.
Matthew R. Wright Saeed Sattari Dion R. Brocks Fakhreddin Jamali 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1992,583(2)
A rapid, inexpensive and sensitive high-performance liquid chromatographic method for the quantitation of ibuprofen enantiomers from a variety of biological fluids is reported. This method uses a commercially available internal standard and has significantly less interference from endogenous co-extracted solutes than do previously reported methods. The method involves the acid extraction of drug and internal standard [(±)-fenoprofen] from the biological fluid with isooctane—isopropanol (95:5) followed by evaporation and derivatization with enthylchloroformate and R-(+)-α-phenylethylamine. Excellent linearity was observed between the peak-area ratio and enantiomer concentration (r > 0.99) over a concentration range of 0.25–50 μg/ml. This method is suitable for the quantitation of ibuprofen from single-dose pharmacokinetic studies involving either rats or humans. 相似文献
16.
Prostaglandin Profiles in Tissue and Blood Vessels from Human Brain 总被引:12,自引:8,他引:4
M. Saeed Abdel-Halim H. von Holst B. Meyerson C. Sachs E. Änggård 《Journal of neurochemistry》1980,34(5):1331-1333
17.
H.O.J. Collier Alison A. Francis Wendy J. McDonald-Gibson S.A. Saeed 《Prostaglandins & other lipid mediators》1976,11(2):219-225
Sulphasalazine (SZ) inhibits prostaglandin (PG) biosynthesis with a potency comparable to that of aceylsalicylate. The metabolites of SZ, sulphapyridine and 5-aminosalicylic acid, were of considerably lower potency as inhibitors of PG biosynthesis in the synthetase preparations used. The inhibition of prostaglandin production by SZ could at least partly account for the clinical utility of sulphasalazine in ulcerative colitis. Sulphapyridine may help to maintain inhibitory concentrations of SZ by restraining bacterial breakdown of the active drug. 相似文献
18.
Further evidence is given that dependence arises from the agonist action of opiates. From this and our previous propositions assigning a fundamental role to neuronal cyclic AMP in (i) the agonist action of opiates and (ii) the expression of the abstinence syndrome, it follows that opiate dependence is a state of heightened potential activity of a neuronal cyclic AMP mechanism, initiated and maintained by the blockade of an adenylate cyclase. Various possible mechanisms are discussed by which this potential is heightened. New evidence is given that morphine and naloxone stimulate prostaglandin biosynthesis without mutual antagonism. Preliminary evidence also is given that (i) the formation of cyclic AMP is enhanced in brain homogenates from heroin-dependent rats, and (ii) an acidified ethylacetate extract of brains of morphine-dependent rats induces quasi-abstinence effects when injected into a lateral cerebral ventricle of naive rats. 相似文献
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Arash Salmaninejad Saeed Farajzadeh Valilou Arezoo Gowhari Shabgah Saeed Aslani Malihe Alimardani Alireza Pasdar Amirhossein Sahebkar 《Journal of cellular physiology》2019,234(10):16824-16837
Over the course of past few years, cancer immunotherapy has been accompanied with promising results. However, preliminary investigations with respect to immunotherapy concentrated mostly on targeting the immune checkpoints, nowadays, emerge as the most efficient strategy to raise beneficial antitumor immune responses. Programmed cell death protein 1 (PD-1) plays an important role in subsiding immune responses and promoting self-tolerance through suppressing the activity of T cells and promoting differentiation of regulatory T cells. PD-1 is considered as an immune checkpoint and protects against autoimmune responses through both induction of apoptosis in antigen-specific T cells and inhibiting apoptosis in regulatory T cells. Several clinical trials exerting PD-1 monoclonal antibodies as well as other immune-checkpoint blockades have had prosperous outcomes and opened new horizons in tumor immunotherapy. Nonetheless, a bulk of patients have failed to respond to these newly emerging immune-based approach and the survival rate was not satisfying. Additional strategies, especially combination therapies, has been initiated and been further promising. Attempts to identify novel and well-suited predictive biomarkers are also sensed. In this review, the promotion of cancer immunotherapy targeting PD-1 immunoinhibitory pathway is discussed. 相似文献