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1.
Forty- and ninety-liter airlift bioreactors have been used successfully to grow hybridoma cell lines in chemically defined serum-free media. In the airlift bioreactor, hybridoma cell growth and monoclonal antibody productivity are comparable to that obtained by conventional cell culture. At sparging rates of 0.60-1.20 vvh (volume of sparged gas per bioreactor volume per hour), the airlift bioreactor achieves rapid mixing and adequate oxygen mass transfer. Foaming is minimal and inconsequential for serum-free media and media supplemented with 5%-10% fetal bovine serum. The use of serum-free medium facilitates monoclonal antibody purification and enhances the purity of the final MAb product. 相似文献
2.
The synthesis of a fluorescent lipid for use in studies of immune recognition of model membranes is described. The molecule has the basic structure HAPTEN-SPACER-LIPID, where fluorescein is the hapten, an oligopeptide (triglycine) is the spacer, and dipalmitoylphosphatidylethanolamine (DPPE) is the lipid. The spacer, which is necessary for immunological reactivity, is first linked via a peptide bond to DPPE. The free N-terminus of the peptidyl-DPPE is then reacted with 5-dichlorotriazinylaminofluorescein (DCTAF) to yield fluoresceinchlorotriazinyltriglycyl-DPPE (FG3P). The structure is confirmed by mass spectrometry and Fourier transform NMR. When FG3P is incorporated into phospholipid vesicles it retains the brilliant fluorescence and high-affinity immunological reactivity of fluorescein. The general synthesis scheme may prove useful in other membrane and lipoprotein applications. 相似文献
3.
William H. Karasov Edwin Petrossian Laura Rosenberg Jared M. Diamond 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1986,156(4):599-609
Summary What digestive adaptations permit herbivorous nonruminant mammals to sustain much higher metabolic rates than herbivorous lizards, despite gross similarity in digestive anatomy and physiology? We approached this question by comparing four herbivorous species eating the same diet of alfalfa pellets: two lizards (chuckwalla and desert iugana) and two mammals (desert woodrat and laboratory mouse). The mammals had longer small and large intestines, greater intestinal surface area, much higher (by an order of magnitude) food intake normalized to metabolic live mass, and much faster food passage times (a few hours instead of a few days). Among both reptiles and mammals, passage times increase with body size and are longer for herbivores than for carnivores. The herbivorous lizards, despite these much slower passage times, had slightly lower apparent digestive efficiencies than the mammals. At least for chuckwallas, this difference from mammals was not due to differences in body temperature regime. Comparisons of chuckwallas and woodrats in their assimilation of various dietary components showed that the woodrat's main advantage lay in greater assimilation of the dietary fiber fraction. Woodrats achieved greater fiber digestion despite shorter residence time, but possibly because of a larger fermentation chamber, coprophagy, and/or different conditions for microbial fermentation. We conclude with a comparative overview of digestive function in herbivorous lizards and mammals, and with a list of four major unsolved questions. 相似文献
4.
Thorsten Klampfl Jelena D. Milosevic Ana Puda Andreas Sch?negger Klaudia Bagienski Tiina Berg Ashot S. Harutyunyan Bettina Gisslinger Elisa Rumi Luca Malcovati Daniela Pietra Chiara Elena Matteo Giovanni Della Porta Lisa Pieri Paola Guglielmelli Christoph Bock Michael Doubek Dana Dvorakova Nada Suvajdzic Dragica Tomin Natasa Tosic Zdenek Racil Michael Steurer Sonja Pavlovic Alessandro M. Vannucchi Mario Cazzola Heinz Gisslinger Robert Kralovics 《PloS one》2013,8(10)
Exome sequencing of primary tumors identifies complex somatic mutation patterns. Assignment of relevance of individual somatic mutations is difficult and poses the next challenge for interpretation of next generation sequencing data. Here we present an approach how exome sequencing in combination with SNP microarray data may identify targets of chromosomal aberrations in myeloid malignancies. The rationale of this approach is that hotspots of chromosomal aberrations might also harbor point mutations in the target genes of deletions, gains or uniparental disomies (UPDs). Chromosome 11 is a frequent target of lesions in myeloid malignancies. Therefore, we studied chromosome 11 in a total of 813 samples from 773 individual patients with different myeloid malignancies by SNP microarrays and complemented the data with exome sequencing in selected cases exhibiting chromosome 11 defects. We found gains, losses and UPDs of chromosome 11 in 52 of the 813 samples (6.4%). Chromosome 11q UPDs frequently associated with mutations of CBL. In one patient the 11qUPD amplified somatic mutations in both CBL and the DNA repair gene DDB1. A duplication within MLL exon 3 was detected in another patient with 11qUPD. We identified several common deleted regions (CDR) on chromosome 11. One of the CDRs associated with de novo acute myeloid leukemia (P=0.013). One patient with a deletion at the LMO2 locus harbored an additional point mutation on the other allele indicating that LMO2 might be a tumor suppressor frequently targeted by 11p deletions. Our chromosome-centered analysis indicates that chromosome 11 contains a number of tumor suppressor genes and that the role of this chromosome in myeloid malignancies is more complex than previously recognized. 相似文献
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6.
In rat basophilic leukemia (RBL) cells and Jurkat T cells, Ca(2+) release-activated Ca(2+) (CRAC) channels open in response to passive Ca(2+) store depletion. Inwardly rectifying CRAC channels admit monovalent cations when external divalent ions are removed. Removal of internal Mg(2+) exposes an outwardly rectifying current (Mg(2+)-inhibited cation [MIC]) that also admits monovalent cations when external divalent ions are removed. Here we demonstrate that CRAC and MIC currents are separable by ion selectivity and rectification properties: by kinetics of activation and susceptibility to run-down and by pharmacological sensitivity to external Mg(2+), spermine, and SKF-96365. Importantly, selective run-down of MIC current allowed CRAC and MIC current to be characterized under identical ionic conditions with low internal Mg(2+). Removal of internal Mg(2+) induced MIC current despite widely varying Ca(2+) and EGTA levels, suggesting that Ca(2+)-store depletion is not involved in activation of MIC channels. Increasing internal Mg(2+) from submicromolar to millimolar levels decreased MIC currents without affecting rectification but did not alter CRAC current rectification or amplitudes. External Mg(2+) and Cs(+) carried current through MIC but not CRAC channels. SKF-96365 blocked CRAC current reversibly but inhibited MIC current irreversibly. At micromolar concentrations, both spermine and extracellular Mg(2+) blocked monovalent MIC current reversibly but not monovalent CRAC current. The biophysical characteristics of MIC current match well with cloned and expressed TRPM7 channels. Previous results are reevaluated in terms of separate CRAC and MIC channels. 相似文献
7.
Yuri N. Belokon Victor I. Maleev Tatiana F. Savel’eva Margarita A. Moskalenko Dmitri A. Pripadchev Victor N. Khrustalev Ashot S. Saghiyan 《Amino acids》2010,39(5):1171-1176
A novel simple synthetic protocol for the preparation of both (2S,4R)- and (2S,4S)-FGlu, applying Michael addition of methyl α-fluoroacrylate to a NiII complex of glycine Schiff base with BPB, was elaborated. In addition, same reaction of mentioned complex with ethyl α-bromoacrylate leads to the NiII complex of the Schiff base of BPB with (2S,4R)-4-bromo-glutamic acid monoester, that can be transformed into the corresponding complexes of 1-aminocyclopropane-1,2-dicarboxylic
acid. The decomposition of the diastereoisomerically pure complexes leads to corresponding enantiomerically enriched (ee > 98%) amino acids. 相似文献
8.
STIM1, an essential and conserved component of store-operated Ca2+ channel function 总被引:10,自引:0,他引:10
Roos J DiGregorio PJ Yeromin AV Ohlsen K Lioudyno M Zhang S Safrina O Kozak JA Wagner SL Cahalan MD Veliçelebi G Stauderman KA 《The Journal of cell biology》2005,169(3):435-445
Store-operated Ca2+ (SOC) channels regulate many cellular processes, but the underlying molecular components are not well defined. Using an RNA interference (RNAi)-based screen to identify genes that alter thapsigargin (TG)-dependent Ca2+ entry, we discovered a required and conserved role of Stim in SOC influx. RNAi-mediated knockdown of Stim in Drosophila S2 cells significantly reduced TG-dependent Ca2+ entry. Patch-clamp recording revealed nearly complete suppression of the Drosophila Ca2+ release-activated Ca2+ (CRAC) current that has biophysical characteristics similar to CRAC current in human T cells. Similarly, knockdown of the human homologue STIM1 significantly reduced CRAC channel activity in Jurkat T cells. RNAi-mediated knockdown of STIM1 inhibited TG- or agonist-dependent Ca2+ entry in HEK293 or SH-SY5Y cells. Conversely, overexpression of STIM1 in HEK293 cells modestly enhanced TG-induced Ca2+ entry. We propose that STIM1, a ubiquitously expressed protein that is conserved from Drosophila to mammalian cells, plays an essential role in SOC influx and may be a common component of SOC and CRAC channels. 相似文献
9.
Jang EB Khrimian A Holler TC Casana-Giner V Lux S Carvalho LA 《Journal of economic entomology》2005,98(4):1139-1143
(-)-Ceralure B1 (ethyl-cis-5-iodo-trans-2-methylcyclohexane-1-carboxylate), a male attractant for the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), is significantly more attractive than trimedlure (tert-butyl esters of 4(5)-chloro-2-methylcyclohexane-1-carboxylate), the current standard male attractant used in detection programs. This article reports studies that compare the effectiveness of racemic ceralure B1, mixtures of racemic ceralure B1 and pure (-)-ceralure B1, and trimedlure in field tests conducted in Hawaii, Africa, and Spain with wild Mediterranean fruit flies and in Florida with sterile released Mediterranean fruit fly. Trapping results showed that doses of (-)-ceralure B1 of 87.5 and 75% are just as effective as the 98% (-)-ceralure B1 and the racemic form to be almost as attractive. In nearly all studies, the racemic ceralure B1 was significantly better than trimedlure. These studies suggest that the racemic ceralure B1 could be a viable replacement for trimedlure in areawide detection programs for Mediterranean fruit fly. Synthesizing racemic ceralure B1 instead of a specific stereoselective enantiomer of ceralure B1 would likely be more cost-effective to produce and also might be useful in control as well as detection of this pest. 相似文献
10.
Belokon YN Gugkaeva ZT Hakobyan KV Maleev VI Moskalenko MA Khrustalev VN Saghyan AS Tsaloev AT Babievsky KK 《Amino acids》2012,43(1):299-308
(S)- and (R)-BIMBOL were efficient PT catalysts of asymmetric Michael addition of prochiral Ni-PBP-Gly (1) to acrylic esters and malonic esters to Ni-PBP-Δ-Ala (2) correspondingly. The salient feature of the catalysis is opposite configurations of Glu prepared via the two paths with BIMBOL of the same configuration and a perspective novel catalytic procedure for the synthesis of Gla derivatives. 相似文献