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611.
Bleesing JJ Souto-Carneiro MM Savage WJ Brown MR Martinez C Yavuz S Brenner S Siegel RM Horwitz ME Lipsky PE Malech HL Fleisher TA 《Journal of immunology (Baltimore, Md. : 1950)》2006,176(11):7096-7103
In this study, we have identified an altered B cell compartment in patients with chronic granulomatous disease (CGD), a disorder of phagocyte function, characterized by pyogenic infections and granuloma formation caused by defects in NADPH activity. This is characterized by an expansion of CD5-expressing B cells, and profound reduction in B cells expressing the memory B cell marker, CD27. Both findings were independent of the age, genotype, and clinical status of the patients, and were not accompanied by altered CD5 and CD27 expression on T cells. Focusing on CD27-positive B cells, considered to be memory cells based on somatically mutated Ig genes, we found that the reduction was not caused by CD27 shedding or abnormal retention of CD27 protein inside the cell. Rather, it was determined that CD27-negative B cells were, appropriately, CD27 mRNA negative, consistent with a naive phenotype, whereas CD27-positive B cells contained abundant CD27 mRNA and displayed somatic mutations, consistent with a memory B cell phenotype. Thus, it appears that CGD is associated with a significant reduction in the peripheral blood memory B cell compartment, but that the basic processes of somatic mutation and expression of CD27 are intact. X-linked carriers of CGD revealed a significant correlation between the percentage of CD27-positive B cells and the percentage of neutrophils with normal NADPH activity, reflective of the degree of X chromosome lyonization. These results suggest a role for NADPH in the process of memory B cell formation, inviting further exploration of secondary Ab responses in CGD patients. 相似文献
612.
A simple and economical modification of the Masson-Fontana method for staining melanin granules and enterochromaffin cells 总被引:2,自引:0,他引:2
Enterochromaffin cells from the small intestine of man, guinea pig, dog, chicken, rabbit, cat and rat were stained using the Masson-Fontana ammoniacal silver method with varying dilutions of silver nitrate solution (0.25 to 5 g per 100 ml of distilled water) and incubation temperatures (60 C and 75 C). The 0.5% solution of silver nitrate gave an argentaffin pattern similar to that of the 5% solution and had two major advantages: economically, since much less silver nitrate is used, and methodologically, since low background resulted with tissue of those species (rat, cat and rabbit) that required unusually long incubation. The staining of melanocytes was similar for all dilutions at the usual staining time (15-30 min). 相似文献
613.
Alfredo J. A. Barbosa Lucia P. F. Castro Ana Margarida M. F. Nogueira 《Biotechnic & histochemistry》1984,59(4):193-196
Enterochromaffin cells from the small intestine of man, guinea pig, dog, chicken, rabbit, cat and rat were stained using the Masson-Fontana ammoniacal silver method with varying dilutions of silver nitrate solution (0.25 to 5 g per 100 ml of distilled water) and incubation temperatures (60 C and 75 C). The 0.5% solution of silver nitrate gave an argentaffin pattern similar to that of the 5% solution and had two major advantages: economically, since much less silver nitrate is used, and methodologically, since low background resulted with tissue of those species (rat, cat and rabbit) that required unusually long incubation. The staining of melanocytes was similar for all dilutions at the usual staining time (15-30 min). 相似文献
614.
Plant regeneration of Actinidia deliciosa var. deliciosa cv. Hayword was obtained from protoplasts isolated from petiole derived long-term callus cultures. Protoplasts were cultured in liquid medium over agarose gelled medium. Regenerated green callus, plated on solid medium, could develop shoots that rooted spontaneously in hormone-less medium. The plants obtained are growing fast in soil and present a normal phenotype.Abbreviations BAP
benzylaminopurine
- 2,4-D
2,4-dichlorophenoxyacetic acid
- DTT
dithiotreitol
- IAA
indole-3-acetic acid
- IBA
indole-3-butyric acid
- Kin
kinetin
- MES
2-(N-morpholino) ethanesulphonic acid
- MS
Murashige and Skoog (1962) medium
- NAA
naphthalene-1-acetic acid
- SH
Schenk and Hildebrandt (1972) medium
This Research was supported by JNICT and INIC 相似文献
615.
Margarida Casadevall Sergi Bonet Jesus Matallanas 《Environmental Biology of Fishes》1993,36(2):127-133
Ophidion barbatum is an oviparous fish species, with external fertilization. In females, a single-lobed ovary is followed by a short oviduct
that opens directly out through the genital opening. Ovarian development is asynchronous. In a mature ovary and during the
breeding season, oocytes in various stages of development can be observed simultaneously. Six stages are described in the
oogenesis from the oogonia to the mature egg, using different histological techniques and based on differences of staining,
of size and on the nucleus and cytoplasm structure, as viewed through a light microscope. Three of them correspond to the
previtellogenic phase and the other three to the vitellogenic phase. Atretic degeneration of eggs is also described. 相似文献
616.
Klaus Rothfels Elizabeth Sexsmith Margaret Heimburger Margarida O. Krause 《Chromosoma》1966,20(1):54-74
Relative amounts of DNA were determined by Feulgen cytophotometry in 22 diploid species of Ranunculaceae (n=7, 8, 9) representing six genera, and exhibiting large differences in chromosome size, but no marked differences in karyotype pattern. Chemical determination of absolute amounts of DNA for six of these species, allowed conversion of all the photometric data into absolute units of DNA. The mean DNA content per nucleus varied from.13×10–11gm in Aquilegia to 5.25×10–11gm in species of Anemone in the section Homalocarpus. The DNA values obtained appeared to be quantized, and data for the majority of species fitted a non-geometrical series with the observed relative terms: 1—8—12—16—20—24—40. The magnitude of these variations in DNA content, the preservation of the karyotype and the tendency towards a simple numerical progression in DNA values, lead us to prefer an interpretation of the evolution of DNA content in terms of differential polynemy to one postulating changes in size of genetic units in an unchanging number of strands per chromosome. 相似文献
617.
Rodrigues ML Scott KA Sansom MS Pereira IA Archer M 《Journal of molecular biology》2008,381(2):341-350
Membrane-bound cytochrome c quinol dehydrogenases play a crucial role in bacterial respiration by oxidizing menaquinol and transferring electrons to various periplasmic oxidoreductases. In this work, the menaquinol oxidation site of NrfH was characterized by the determination of the X-ray structure of Desulfovibrio vulgaris NrfHA nitrite reductase complex bound to 2-heptyl-4-hydroxyquinoline-N-oxide, which is shown to act as a competitive inhibitor of NrfH quinol oxidation activity. The structure, at 2.8-Å resolution, reveals that the inhibitor binds close to NrfH heme 1, where it establishes polar contacts with two essential residues: Asp89, the residue occupying the heme distal ligand position, and Lys82, a strictly conserved residue. The menaquinol binding cavity is largely polar and has a wide opening to the protein surface. Coarse-grained molecular dynamics simulations suggest that the quinol binding site of NrfH and several other respiratory enzymes lie in the head group region of the membrane, which probably facilitates proton transfer to the periplasm. Although NrfH is not a multi-span membrane protein, its quinol binding site has several characteristics similar to those of quinone binding sites previously described. The data presented here provide the first characterization of the quinol binding site of the cytochrome c quinol dehydrogenase family. 相似文献
618.
Marta Muñoz Margarida Casadevall Sergi Bonet Irani Quagio-Grassiotto 《Environmental Biology of Fishes》2000,58(1):53-59
The ultrastructure of ovarian sperm storage of Helicolenus dactylopterus dactylopterus is described, before and after the spawning period. The spermatozoa remain inside cryptal structures that are situated in the interlamellar gaps and are connected to the ovarian lumen by a duct. This complex forms a highly specialised structure. During the long storage period, crypts are richly vascularised. Their surrounding simple epithelia have intercellular junctions that may serve to protect the spermatozoa from the female immune system. At the moment during which insemination of mature oocytes occurs, the sperm may be expelled from cryptal structures by means of a spasmodic contraction. During the post spawning period, residual spermatozoa that remain in the crypts are eliminated by cryptal phagocytes. At the end of the process the crypts contain only an amorphous material. 相似文献
619.
Tiago G. Fernandes Ana M. Fernandes-Platzgummer Cláudia Lobato da Silva Maria Margarida Diogo Joaquim M. S. Cabral 《Biotechnology letters》2010,32(1):171-179
There is a need for a deeper understanding of the biochemical events affecting embryonic stem (ES) cell culture by analyzing
the expansion of mouse ES cells in terms of both cell growth and metabolic kinetics. The influence of the initial cell density
on cell expansion was assessed. Concomitantly, the biochemical profile of the culture was evaluated, which allowed measuring
the consumption of important substrates, such as glucose and glutamine, and the production of metabolic byproducts, like lactate.
The results suggest a more efficient cell metabolism in serum-free conditions and a preferential use of glutaminolysis as
an energy source during cell expansion at low seeding densities. This work contributes to the development of fully-controlled
bioprocesses to produce relevant numbers of ES cells for cell therapies and high-throughput drug screening. 相似文献
620.
Morte MI Rodrigues AM Soares D Rodrigues AS Gamboa S Ramalho-Santos J 《Animal reproduction science》2008,107(1-2):36-47
The goal of this work was to correlate oxidative stress caused by reactive oxygen species (ROS) and DNA damage with classic semen parameters in spermatozoa and seminal plasma of fertile and subfertile stallions. Oxidation was measured in both lipids and proteins, using the thiobarbituric acid reactive species (TBARS) assay and the DNPH carbonyl groups assay, respectively. Sperm DNA damage was monitored using the TUNEL assay. These parameters were monitored in samples obtained during the breeding and the non-breeding seasons. In general, fertile stallions showed better classical semen parameters, and those parameters improved from the non-breeding to the breeding season, although an increase in sperm production was accompanied by a decrease in the semen quality from subfertile stallions in the breeding season. In terms of oxidation levels we found that there were clear differences whether lipids or proteins were considered. In the breeding season there seemed to be a tendency towards normalizing lipid oxidation in spermatozoa and seminal plasma, and protein oxidation in the seminal plasma, of both fertile and subfertile animals. Thus, differences monitored in the non-breeding season were no longer visible. Interestingly, a higher level of protein oxidation was found in the sperm of fertile animals in the breeding season. Considering that there were positive correlations between sperm protein oxidation and sperm motility and vitality, these results suggests that the oxidation of semen proteins may be important for sperm function. On the other hand, lipid oxidation in the seminal plasma seemed to be a general indicator for sperm damage. In the non-breeding season positive correlations between lipid and protein oxidation levels in both sperm and seminal plasma and several defects in sperm function were found, but only for subfertile animals, thus suggesting that lipid and protein oxidation may aid in the identification of subfertile stallions during the non-breeding season. Levels of ROS production never seemed to result in compromised sperm DNA integrity, indicating that measurements were within physiological levels and/or that there is an efficient antioxidant activity in stallion sperm cells. 相似文献