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1.
2.
An unusual case of neurofibrosarcoma of the cranio-orbital-maxillary region was resected by a combined neurosurgical and plastic surgical team. The resulting defect was reconstructed in one stage with a free rectus abdominis myocutaneous flap, obviating the need for subsequent prosthetic obturation of the maxillary defect. This reconstructive technique expedited the patient's convalescent period, allowing him to return to work 3 weeks following surgery. Wound healing was uneventful, and the cosmetic result was acceptable to the patient. 相似文献
3.
Summary Auxin-induced highly vacuolated thin-walled callus cells of several plant species, when ruptured, released large numbers of subcellular units most of which were enucleate. These enucleate microplasts are surrounded by an inner membrane of the cell, most probably derived from the tonoplast. When microplasts isolated fromSaintpaulia callus were cultured in a medium supplemented with growth substances they formed a thin wall and underwent budding. Microplasts could be useful for various studies in plant cell biology and for genetic manipulations. 相似文献
4.
Strategies for signal amplification in nucleic acid detection 总被引:3,自引:0,他引:3
S. Calin Andras J. Brian Power Edward C. Cocking Michael R. Davey 《Molecular biotechnology》2001,19(1):29-44
Many aspects of molecular genetics necessitate the detection of nucleic acid sequences. Current approaches involving target
amplification (in situ PCR, Primed in situ Labeling, Self-Sustained Sequence Replication, Strand Displacement Amplification), probe amplification (Ligase Chain Reaction,
Padlock Probes, Rolling Circle Amplification) and signal amplification (Tyramide Signal Amplification, Branched DNA Amplification)
are summarized in the present review, together with their advantages and limitations. 相似文献
5.
Cutting edge: precursor frequency affects the helper dependence of cytotoxic T cells. 总被引:3,自引:0,他引:3
Justine D Mintern Gayle M Davey Gabrielle T Belz Francis R Carbone William R Heath 《Journal of immunology (Baltimore, Md. : 1950)》2002,168(3):977-980
Generation of CTL immunity often depends on the availability of CD4 T cell help. In this report, we show that CTL responses induced by cross-priming can be converted from CD4-dependent to CD4-independent by increasing the frequency of CTL precursors. In the absence of CD4 T cells, high numbers of CTL precursors were able to expand in number and become effector CTL. The ability of high frequencies of CD8 T cells to override help was not due to their ability to signal CD40 via expression of CD154. These findings suggest that when precursor frequencies are high, priming of CD8 T cell responses may not require CD4 T cell help. 相似文献
6.
Summary The sensory receptor responsive to pressure applied internally to the ventral abdominal body wall of the blood-feeding insects, Rhodnius prolixus, is a single sense cell containing, at its distal end, a cilium enclosed within a scolopale, a densely staining structure characteristic of insect scolopidial sensilla. A small spherical structure lies within a dilation near the midregion of the cilium, and contains nine heavily staining bodies, the position of each corresponding to a pair of microtubules in the cilium. Proximal to the dilation, the microtubules are organized in a ring of nine pairs with one microtubule of each pair associated with dyneinlike arms. Dastal to the dilation a central pair of microtubules is present, but dyneinlike arms are absent. The scolopale cell, which gives risc to the scolopale, has cytoplasmic invaginations that form an elaborate array of extracellular compartments surrounding the body wall of the sense cell. These compartments may serve to dampen high frequency vibrations permitting the receptor to respond to pressure exerted by touch, an attribute in keeping with the receptor's proposed function of detecting abdominal distension related to the size and movement of the stomach. 相似文献
7.
Larry R. Hilburn Ronald B. Davey John E. George J. Mathews Pound 《Experimental & applied acarology》1991,11(1):23-36
WhenBoophilus microplus and Type-II hybrids (B. microplus females×B. annulatus males) were released simultaneously onto bovine hosts, mating between the two forms appeared not to be at random. There were more contypic and fewer intertypic matings than predicted under an assumption of panmixia. An examination of the patterns of matings revealed that more of the matings on the first two days of detachment were between the two sexes ofB. microplus. Engorged females dropping on the last four days of maximum female detachment were predominantly hybrids mated to bothB. microplus and hybrid males. The non-random mating pattern does not appear to be caused by assortative mating betweenB. microplus and Type-II hybrids, but because theB. microplus were competnet to mate two days before the hybrids and theB. microplus males compete for mates of both types better than the Type-II males. 相似文献
8.
Approximately 106 protoplast-derived cell colonies of sainfoin were stressed with streptomycin and two resistant colonies were recovered. Plants regenerated from these colonies could be recallused on streptomycin-containing medium three years after growth in the absence of the antibiotic.Ultrastructural studies showed cells of resistant callus grown in the presence of streptomycin to contain chloroplasts with internal thykaloids and grana. Such mutant plants should be useful in designing biochemical selection schemes to recover somatic hybrids and cybrids.Abbreviations BAP
6 - benzylamino purine
- NAA
- napthaleneacetic acid 相似文献
9.
Summary When suspensions of sycamore cells are cultured in a synthetic medium containing 1.0 mg/l 2,4-D and 0.25 mg/l kinetin, maximum cell yield is obtained with an initial concentration of 6 per cent sucrose. There is a progressive increase in dry weight per cell, decline in extractive-free weight as a percentage of cell dry weight and increase in lignin content per cell as the initial sucrose concentration is increased from 1 per cent to 15 per cent. The percentage of lignin in the extractive-free cell residue is further enhanced by increasing the level of 2,4-D to 10 mg/l or by growing the cells in an auxin-free medium containing 10 mg/l kinetin.When the cell suspensions are treated with phloroglucinol/HCl it is found that only a proportion of the cells contain lignin, that this lignin occurs in the protoplasts and in plates between the cells, and that lignin is present in the culture medium.Electron micrographs confirmed the absence of any secondary wall such as is characteristic of tracheary elements. Cells cultured in the presence of 6 per cent sucrose or higher levels showed numerous amyloplasts and frequently the presence of electron opaque material. This occurs in the irregular but not frequent wall thickenings, as droplets in the vacuoles and as amorphous sheets between the cells. Pictures showing such electron opaque droplets clustered on the inner face of the tonoplasts suggest that this material is formed in the cytoplasm and released into the vacuoles. In addition these cells are characterised by the presence of fine electron opaque granular material in their vacuoles and external to their protoplasts. Cultures richest in lignin showed the highest content of electron opaque globules in, and amorphous sheets between, the cells and it is suggested that these correspond to lignin or a lignin-hemicellulose complex. In the presence of 15 per cent sucrose many cells showing breakdown of organised structure were observed; they were characterised by the persistence of mitochondria and particularly of the amyloplasts and by their high content of the electron opaque material equated with lignin. This material was also present in the dead cells. 相似文献
10.
Genetic and Biophysical Study of R Plasmids Conferring Sulfonamide Resistance in Shigella Strains Isolated in 1952 and 1956 总被引:6,自引:2,他引:4 下载免费PDF全文
The conjugative plasmids determining sulfonamide resistance in five Shigella strains, each isolated from a different patient, have been characterized. One S. flexneri 2a strain, isolated in 1952, harbored an fi(+) plasmid of molecular weight 53 x 10(6), which specified synthesis of F-like pili and bore determinants for sulfonamide resistance (Su) and bacteriocinogeny (Col). This plasmid was compatible with plasmids of groups F(I), F(II), I(alpha), and P. A second S. flexneri 2a strain isolated in 1952 harbored an fi(-) plasmid of molecular weight 59 x 10(6), bearing the Su determinant and compatible with all plasmids tested. This strain also harbored an fi(+) group-F(II) plasmid of molecular weight 42 x 10(6), which bore the Col determinant and specified synthesis of F-like pili. Three S. dysenteriae 2 strains isolated in 1956 carried apparently identical fi(-) plasmids of molecular weight 58 x 10(6), which bore the Su determinant, could form transconjugants in Pseudomonas but not in Proteus, and were incompatible with the P-group plasmid RP4. 相似文献