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41.
Francisco dos Santos Pedro Z. Andrade Joana S. Boura Manuel M. Abecasis Cláudia Lobato da Silva Joaquim M.S. Cabral 《Journal of cellular physiology》2010,223(1):27-35
The low bone marrow (BM) MSC titers demand a fast ex vivo expansion process to meet the clinically relevant cell dosage. Attending to the low oxygen tension of BM in vivo, we studied the influence of hypoxia on human BM MSC proliferation kinetics and metabolism. Human BM MSC cultured under 2% (hypoxia) and 20% O2 (normoxia) were characterized in terms of proliferation, cell division kinetics and metabolic patterns. BM MSC cultures under hypoxia displayed an early start of the exponential growth phase, and cell numbers obtained at each time point throughout culture were consistently higher under low O2, resulting in a higher fold increase after 12 days under hypoxia (40 ± 10 vs. 30 ± 6). Cell labeling with PKH26 allowed us to determine that after 2 days of culture, a significant higher cell number was already actively dividing under 2% compared to 20% O2 and BM MSC expanded under low oxygen tension displayed consistently higher percentages of cells in the latest generations (generations 4–6) until the 5th day of culture. Cells under low O2 presented higher specific consumption of nutrients, especially early in culture, but with lower specific production of inhibitory metabolites. Moreover, 2% O2 favored CFU‐F expansion, while maintaining BM MSC characteristic immunophenotype and differentiative potential. Our results demonstrated a more efficient BM MSC expansion at 2% O2, compared to normoxic conditions, associated to an earlier start of cellular division and supported by an increase in cellular metabolism efficiency towards the maximization of cell yield for application in clinical settings. J. Cell. Physiol. 223: 27–35, 2010. © 2009 Wiley‐Liss, Inc. 相似文献
42.
Many therapeutic targets are intracellular proteins and molecules designed to interact with them must effectively bind to their target inside the cell. Intracellular antibodies (intrabodies) recognise and bind to proteins in cells and various methods have been developed to produce such molecules. Intracellular antibody capture (IAC) is based on a genetic screening approach and is a facile methodology with which effective intracellular antibodies can be obtained. During the development of the IAC technology, consensus immunoglobulin variable frameworks were identified which can form the basis of intrabody libraries for direct screening. In this paper, we describe the de novo synthesis of intrabody libraries based on the IAC consensus sequence. The procedure comprises in vitro production of a single antibody gene fragment from oligonucleotides and diversification of CDRs of the immunoglobulin variable domain by mutagenic PCR. Completely de novo intrabody libraries can be rapidly generated in vitro by these approaches. As an example, a single immunoglobulin VH domain intrabody library was screened directly in yeast with an oncogenic BCR-ABL antigen bait and distinct antigen binders were isolated illustrating the functional utility of the library. This second generation IAC approach (IAC2) has many practical advantages, in particular the ability to isolate intrabodies by direct genetic selection, which obviates the need for in vitro production of antigen for pre-selection of antibody fragments. 相似文献
43.
Paraense WL 《Memórias do Instituto Oswaldo Cruz》2003,98(1):51-67
In the course of two trips to Central America (June 1967 and JulyAugust 1976) I had the opportunity of collecting topotypic specimens of Planorbis nicaraguanus Morelet, 1849, anatomically defined in this paper, and of P. yzabalensis Crosse & Fischer, 1879, the identity of the latter with Drepanotrema anatinum (Orbigny, 1835) is confirmed. The following planorbid species were also found: Helisoma trivolvis (Say, 1817) in Nicaragua, Guatemala, Costa Rica and Belize; H. duryi (Wetherby, 1879) in Costa Rica; Biomphalaria helophila (Orbigny, 1835) in Guatemala, Belize, Nicaragua, Costa Rica and El Salvador; B. kuhniana (Clessin, 1883) in Panama; B. obstructa (Morelet,1849) in Guatemala, Belize and El Salvador; B. straminea (Dunker, 1848) in Costa Rica; B. subprona (Martens, 1899) in Guatemala; D. anatinum (Orbigny,1835) in Belize, Guatemala, Nicaragua and Costa Rica; D. depressissimum (Moricand,1839) in Nicaragua, Costa Rica and Panama; D. lucidum (Pfeiffer, 1839) in Guatemala, Belize and Nicaragua; D. surinamense (Clessin, 1884) in Costa Rica and Panama; and Gyraulus percarinatus sp. n. in Panama. The occurrence of B. kuhniana and D. surinamense is first recorded in Central America, and Gyraulus percarinatus is the first representative of the genus provenly occurring in the American continent south of the United States. The following synonymy is proposed: Planorbis declivis Tate, 1870 = Biomphalaria helophila (Orbigny, 1835); Planorbis isthmicus Pilsbry, 1920 = Biomphalaria kuhniana (Clessin, 1883); Planorbis cannarum Morelet, 1849 and Segmentina donbilli Tristram, 1861 = Biomphalaria obstructa (Morelet, 1849); and Planorbis yzabalensis Crosse & Fischer, 1879 = Drepanotrema anatinum (Orbigny, 1835), confirming Aguayo (1933). 相似文献
44.
Parreiras PM Lobato FC Alencar AP Figueiredo Td Gomes HM Boéchat N Lage AP Assis RA Pereira MA Souza PR Mota PM Suffys PN 《Memórias do Instituto Oswaldo Cruz》2004,99(7):749-752
Transmission of Mycobacterium bovis from cattle to humans has been reported and can cause tuberculosis (Tb) and a problem in certain risk populations. Therefore, knowledge of resistance of M. bovis towards antibiotics used for therapy of human Tb could help avoiding cure delay and treatment cost increase when dealing with drug resistant organisms. We therefore evaluated the susceptibility of M. bovis isolates towards streptomycin, isoniazide, rifampicin, ethambutol, and ethionamide, the first line antibiotics for human Tb. Therefore, 185 clinical samples from cattle with clinical signs of tuberculosis were processed and submitted to culturing and bacterial isolates to identification and drug susceptibility testing using the proportion method. Among 89 mycobacterial strains, 65 were identified as M. bovis and none were resistant to any of the antibiotics used. Confirmation of present results by future studies, enrolling a large number of isolates and designed to properly represent Brazilian regions, may favor the idea of using isoniazide preventive therapy as part of a Tb control strategy in special situations. Also, nucleic acids from bacterial isolates were submitted to rifoligotyping, a recently described reverse hybridization assay for detection of mutations causing resistance towards rifampicin. Concordance between the conventional and the molecular test was 100%, demonstrating the use of such methodology for rapid evaluation of drug susceptibility in M. bovis. 相似文献
45.
Kleiman F Pietrokovsky S Paraense WL Wisnivesky-Colli C 《Memórias do Instituto Oswaldo Cruz》2004,99(1):23-24
We report the first finding of Lymnaea viatrix south of parallel 41 masculine S, in rural and urban areas from Argentina. Ninety snails were collected during year 2000, from a concrete pond at a Public Square in El Bolsón Village, Río Negro province, and 811 snails in November 1999, and during 2000 from waterbodies within a farm at Cholila locality, Chubut province. Fasciola hepatica infection was detected in 0.9% snails from the rural area. We discuss the potential risk of L. viatrix to public health in urban areas and its epidemiological importance in rural areas of the Andean Patagonian region. 相似文献
46.
da Silva CL Gonçalves R Lemos F Lemos MA Zanjani ED Almeida-Porada G Cabral JM 《Bioprocess and biosystems engineering》2003,25(6):365-369
In this study, we described the modelling of the expansion/maintenance of human hematopoietic stem/progenitor cells from adult human bone marrow. CD 34(+)-enriched cell populations from bone marrow were cultured in the presence and absence of human stroma in serum-free media containing bFGF, SCF, LIF and Flt-3 ligand for several days. The cells in the culture were analysed for expansion and phenotype by flow cytometry. Although significant expansion of bone marrow cultures occurred in the presence and absence of human stroma, the results of expansion were effectively better in the presence of a stromal layer. In both situations the phenotypic analysis demonstrated a great expansion of CD 34(+)38(-) cells. The differentiative potential of bone marrow CD 34(+) cells co-cultured with human stroma was primarily shifted towards the myeloid lineage with the presence of CD 15 and CD 33. 相似文献
47.
Homologies in Cambrian Onychophora 总被引:4,自引:0,他引:4
LARS RAMSKÖLD 《Lethaia: An International Journal of Palaeontology and Stratigraphy》1992,25(4):443-460
Marine animals related to Recent onychophorans form a significant component in Cambrian faunas. Twelve characters are analysed for homologies in the seven best known Cambrian onychophorans. New morphological evidence and homology analyses for several characters indicate an anteroposterior reversal of Hallucigenia and Microdictyon . Proposed expansion of the trunk in Microdietyon during compaction is rejected. A jaw is tentatively identified in Onychodictyon . The shape of the annulations and the disposition of the tenth leg pair in Aysheaia are reinterpreted, and the suggestion of two somites to the first appendage pair is rejected. A suggested morphocline may mirror the phylogeny of the group. The taxonomic confusion surrounding the supposed radiolarian family Eoconchariidae is cleared 相似文献
48.
Patrícia Favoretto Carla Cristina da Silva Aline Gomes Tavares Gabriela Giatti Patrícia Favoretto Moraes Mary Tulia Vargas Lobato Maria Bernadete Silvarolla Guerreiro Oliveiro-Filho Mirian Perez Maluf 《Molecular breeding : new strategies in plant improvement》2017,37(3):31
Breeding of caffeine-free coffee cultivars require tools for an early selection of progenies bearing this later trait. Genes from caffeine synthesis and degradation represent major targets for the development of molecular markers for assisted selection. In this study, we characterized SNPs identified on the caffeine synthase gene from AC1 mutant, a naturally caffeine-free arabica coffee plant. Molecular analysis of normal and mutant sequences indicates the occurrence of SNPs in protein domains, potentially associated with caffeine synthesis in coffee. Progenies F2, F1BC1 and BC from crosses of AC mutants and elite cultivars were evaluated regarding caffeine content in grains and genomic segregation profile of selected SNPs. Genotyping analysis allowed the discrimination between homozygous and heterozygous plants. Quantification of caffeine content indicated a significant variability among progenies and a low frequency of caffeine-free plants. Statistical analyses of genotyping and phenotyping results showed significant association between presence of selected SNPs and reduced caffeine content. Moreover, this association occurs through all evaluated genetic backgrounds and generations, indicating an inheritance stability of both trait and markers. The molecular markers described here represent a successful case of assisted-selection in coffee, indicating their potential use for breeding of caffeine-free cultivars. 相似文献
49.
M I Arrieta B Martinez B Criado N Lobato C M Lostao 《Human biology; an international record of research》1992,64(5):705-716
Palmar dermatoglyphics of a sample including 552 males and 701 females from 8 Basque valleys were analyzed. We studied the frequency of palmar pattern types and compared them using correspondence the frequency of palmar pattern types and compared them using correspondence analysis. The results of this comparative study show that there is diversity among valleys and also that this diversity depends on the trait and on sex. Genetic drift could explain this variability found in the Basque population. 相似文献
50.
Eduardo Bruno Lobato Martins Rubens Chojniak Luis Paulo Kowalski Ulisses Ribaldo Nicolau Eduardo Nóbrega Pereira Lima Almir Galv?o Vieira Bitencourt 《PloS one》2015,10(11)