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81.
Ampicillin/sulbactam was used for the treatment of experimental osteomyelitis due to Staphylococcus aureus in rabbits. Treatment with 200 mg/kg (ampicillin) three times a day sterilized 40% of infected rabbit bones. The results of 4 weeks of treatment with ampicillin/sulbactam for chronic experimental staphylococcal osteomyelitis were comparable to those obtained previously with cephalothin and with oxacillin in previous studies and were not as good as those with clindamycin alone or combination therapy that included rifampin. 相似文献
82.
Experimental osteomyelitis. V. Therapeutic trials with oxacillin and sisomicin alone and in combination 总被引:6,自引:0,他引:6
C W Norden 《The Journal of infectious diseases》1978,137(2):155-160
Oxacillin was used alone and in combination with sisomicin in the treatment of experimental osteomyelitis due to Staphylococcus aureus in rabbits. Within diseased bone, levels of oxacillin and sisomicin remained higher than the minimal inhibitory concentration for 2 and 6 hr, respectively, after injection of 50 mg of oxacillin/kg and 10 mg of sisomicin/kg. Treatment with 50 mg of oxacillin/kg four times daily or 50 mg/kg every 4 hr around the clock for 28 days sterilized 30% of the rabbit bones. Sisomicin (10 mg/kg) injected twice daily for 28 days sterilized only 5% of the rabbit bones. In contrast, treatment with the combination of oxacillin and sisomicin for either 14 or 28 days was significantly more effective, sterilizing 78% and 85%, respectively, of the bones of treated animals. S. Aureus isolated from bones of animals treated with sisomicin alone contained aminoglycoside-resistant microcolonies. Resistant microcolonies were not recovered from animals treated with oxacillin or with the combination of oxacillin plus sisomicin. In vitro studies of bacterial killing by each antibiotic alone and in combination showed more bacterial killing with the combination than with either agent alone; in vitro the combination prevented emergence of resistant microcolonies. Combination antibiotic therapy appears to be more effective in treatment of experimental osteomyelitis due to S. aureus than therapy with a single agent. 相似文献
83.
The immunologic responses of 100 children hospitalized with meningitis due to Haemophilus influenzae type b were measured by the bactericidal antibody assay (BAA) and radioimmunoassay (RIA) for detection of antibody. Short-term (14-17 days after onset of illness) responses were detected by RIA alone in 20 children, by BAA alone in six, and by both tests in 23. The more sensitive RIA detected 20 children who would have been labeled "immunologically unresponsive" had only BAA been used. The magnitude of the antibody response was clearly related to age. Of 26 children with no immediate antibody response, 11 still had no rise in titer of antibody when restudied two to 20 months later; the remaining 15 had subsequent increases in titer. Nine of 10 children who showed an immediate antibody response remained positive when additional blood smaples were taken two to 18 months later. Over half of the children initially unresponsive to H. influenzae type b meningitis subsequently developed specific antibodies. The remainder, who failed to acquire detectable antibodies at either the acute stage of illness or late in convalescence, deserve further investigation as to the nature of their immunologic hyporesponsiveness to H. influenzae type b meningitis. 相似文献
84.
Establishment of primary patient‐derived xenografts of palliative TURP specimens to study castrate‐resistant prostate cancer
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85.
86.
Amplification of genes encoding human myeloid membrane antigens after DNA-mediated gene transfer 总被引:2,自引:0,他引:2
Spontaneous amplification of genes encoding two different human myeloid surface antigens was observed after DNA-mediated gene transfer of cellular DNA from the human myeloid cell line HL-60 into NIH-3T3 mouse fibroblasts. Transformed recipient cells with highly amplified expression of either of two donor membrane polypeptides, gp150 or p67, were isolated with a fluorescence-activated cell sorter (FACS), using monoclonal antibodies specific for human myeloid cells. Immunoprecipitation of enzymatically radioiodinated polypeptides from the surface of transformed NIH-3T3 cells confirmed that expression of these proteins was amplified tenfold to 20-fold in comparison to their expression on human myeloid cell lines. The cellular DNA of cloned secondary and tertiary transformants expressing high levels of gp150 and p67 contained amplified sets of DNA restriction fragments that hybridized with human repetitive DNA sequences. Cytogenetic analysis of subclones overexpressing gp150 revealed extrachromosomal double minutes (DMs), whose presence correlated with the unstable expression of the membrane polypeptide. Human sequences in gp150-positive clones did not localize to chromosomes, consistent with their association with extrachromosomal DMs. By contrast, p67-positive subclones stably expressed the antigen, and in situ hybridization to metaphase spreads demonstrated that amplified human DNA sequences were integrated into a specific marker chromosome. Cytogenetic analysis of the parental NIH- 3T3 subclone used in these studies disclosed DMs in a low percentage of metaphases, suggesting that the recipient cells have a propensity for amplifying donor DNA. 相似文献
87.
Molecular heterogeneity in acute leukemia lineage switch 总被引:1,自引:0,他引:1
Gagnon GA; Childs CC; LeMaistre A; Keating M; Cork A; Trujillo JM; Nellis K; Freireich E; Stass SA 《Blood》1989,74(6):2088-2095
Six cases of acute leukemia that underwent lineage switch from acute lymphocytic leukemia to acute myelogenous leukemia are reported. The mean age of the patients was 24 years, time to conversion was 36 months, and survival after conversion was only 3 months. Of the three cases which showed abnormal metaphases at both diagnosis and conversion, two (cases 2, 5) showed related cytogenetic abnormalities, and the third showed (case 3) independent chromosomal changes. Molecular analysis for immunoglobulin heavy chain and T-cell receptor beta chain genes showed that five of the six cases had rearrangement of at least one of these lymphoid associated genes at conversion to acute myelogenous leukemia. The single case (case 3) in which there were no lymphoid gene rearrangements at conversion was also the only case in which independent karyotypic abnormalities at diagnosis and conversion were demonstrated. Our findings suggest that lineage switch can represent either relapse of the original clone with heterogeneity at the molecular level or the emergence of a second new leukemic clone without molecular heterogeneity. 相似文献
88.
89.
Use of intrinsic modes in biology: Examples of indicial response of pulmonary blood pressure to ± step hypoxia
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Wei Huang Zheng Shen Norden E. Huang Yuan Cheng Fung 《Proceedings of the National Academy of Sciences of the United States of America》1998,95(22):12766-12771
Recently, a new method to analyze biological nonstationary stochastic variables has been presented. The method is especially suitable to analyze the variation of one biological variable with respect to changes of another variable. Here, it is illustrated by the change of the pulmonary blood pressure in response to a step change of oxygen concentration in the gas that an animal breathes. The pressure signal is resolved into the sum of a set of oscillatory intrinsic mode functions, which have zero “local mean,” and a final nonoscillatory mode. With this device, we obtain a set of “mean trends,” each of which represents a “mean” in a definitive sense, and together they represent the mean trend systematically with different degrees of oscillatory content. Correspondingly, the oscillatory content of the signal about any mean trend can be represented by a set of partial sums of intrinsic mode functions. When the concept of “indicial response function” is used to describe the change of one variable in response to a step change of another variable, we now have a set of indicial response functions of the mean trends and another set of indicial response functions to describe the energy or intensity of oscillations about each mean trend. Each of these can be represented by an analytic function whose coefficients can be determined by a least-squares curve-fitting procedure. In this way, experimental results are stated sharply by analytic functions. 相似文献
90.
High resolution of heterogeneity among human neutrophil granules: physical, biochemical, and ultrastructural properties of isolated fractions 总被引:4,自引:1,他引:4
Previous studies on the fractionation of human neutrophil granules have identified two major populations: myeloperoxidase (MPO)-containing azurophil, or primary, granules and MPO-deficient specific, or secondary, granules. Peripheral blood neutrophils from individual donors were lysed in sucrose-free media by either hypotonic shock or nitrogen cavitation. Using a novel two-gradient Percoll density centrifugation system, the granule-rich postnuclear supernatant was rapidly (ten minutes) and reproducibly resolved into 13 granule fractions (L1 through L8 and H1 through H5). Granule flotation and recentrifugation experiments on both continuous, self-generated and multiple-step gradients using individual and mixed isolated fractions demonstrated that the banding patterns were isopycnic and nonartifactual. Isolated granules were intact based on the findings that biochemical latency of several granule enzymes was greater than 95%, and thin-sectioned electron micrographs demonstrated intact granule profiles. Biochemical analyses of the granule marker proteins MPO, beta-glucuronidase, lysozyme, and lactoferrin indicated that a number of the fractions were related to the major azurophil and specific granule populations. Lactoferrin was found in ten of 13 fractions (L1 through L8, H1 to H2), whereas MPO was found in every fraction. Consistent with these biochemical data, all fractions exhibited varying degrees of heterogeneity based on ultrastructural morphology and cytochemistry, including diaminobenzidine (DAB) reactivity for peroxidase and periodate-thiocarbohydrazide-silver proteinate (PA-TCH-SP) staining for complex glycoconjugates. A variable but significant percentage (23% to 70%) of the granules in fractions L1 through L8 and H1 and H2 showed DAB reactivity, while about 90% of the granules in fractions H3 through H5 were peroxidase positive. These results demonstrated that DAB-reactive granules spanned the entire range of granule size and density. Ultrastructural PA-TCH-SP staining of isolated granule fractions revealed patterns similar to those of granules in intact neutrophils at different stages of development. Granules from human acute promyelocytic leukemia cells (HL-60) exhibited a surprisingly low density compared with typical azurophil granules from normal, mature neutrophils. The data suggest that both functional and maturational differences contribute to granule heterogeneity, and provide a new practical and conceptual framework for further defining the phenomenon of neutrophil granule heterogeneity. 相似文献