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61.
Ruth H. Pauli Alvin F. Coburn With the Assistance of Florence Stone Ph.D. 《The Journal of experimental medicine》1937,65(4):595-612
The cross-reactions which interfere with satisfactory serological identification of hemolytic streptococcus are due to anticarbohydrate in the sera used for typing. This antibody can be removed easily by absorption with purified streptococcus carbohydrate, and type identification is then readily established. The serological classification of hemolytic streptococcus from throat infections contracted in New York during 1935 and 1936 showed the predominance of types 4, 13 and 22. Type 13 appeared to be the most serious in initiating rheumatic activity during this period of observation. 相似文献
62.
63.
D.R. MacFadden B. Coburn N. Shah A. Robicsek R. Savage M. Elligsen N. Daneman 《Clinical microbiology and infection》2019,25(1):108.e1-108.e7
Objectives
Early empiric antibiotic therapy in patients can improve clinical outcomes in Gram-negative bacteraemia. However, the widespread prevalence of antibiotic-resistant pathogens compromises our ability to provide adequate therapy while minimizing use of broad antibiotics. We sought to determine whether readily available electronic medical record data could be used to develop predictive models for decision support in Gram-negative bacteraemia.Methods
We performed a multi-centre cohort study, in Canada and the USA, of hospitalized patients with Gram-negative bloodstream infection from April 2010 to March 2015. We analysed multivariable models for prediction of antibiotic susceptibility at two empiric windows: Gram-stain-guided and pathogen-guided treatment. Decision-support models for empiric antibiotic selection were developed based on three clinical decision thresholds of acceptable adequate coverage (80%, 90% and 95%).Results
A total of 1832 patients with Gram-negative bacteraemia were evaluated. Multivariable models showed good discrimination across countries and at both Gram-stain-guided (12 models, areas under the curve (AUCs) 0.68–0.89, optimism-corrected AUCs 0.63–0.85) and pathogen-guided (12 models, AUCs 0.75–0.98, optimism-corrected AUCs 0.64–0.95) windows. Compared to antibiogram-guided therapy, decision-support models of antibiotic selection incorporating individual patient characteristics and prior culture results have the potential to increase use of narrower-spectrum antibiotics (in up to 78% of patients) while reducing inadequate therapy.Conclusions
Multivariable models using readily available epidemiologic factors can be used to predict antimicrobial susceptibility in infecting pathogens with reasonable discriminatory ability. Implementation of sequential predictive models for real-time individualized empiric antibiotic decision-making has the potential to both optimize adequate coverage for patients while minimizing overuse of broad-spectrum antibiotics, and therefore requires further prospective evaluation.Summary
Readily available epidemiologic risk factors can be used to predict susceptibility of Gram-negative organisms among patients with bacteraemia, using automated decision-making models. 相似文献64.
65.
66.
Carlson D Hernandez J Bloom BJ Coburn J Aversa JM Steere AC 《Arthritis and rheumatism》1999,42(12):2705-2709
OBJECTIVE: To determine whether Borrelia burgdorferi DNA may be detected in synovial tissue from patients with Lyme arthritis who have persistent synovial inflammation after antibiotic treatment. METHODS: Synovial specimens obtained at synovectomy from 26 patients with antibiotic treatment-resistant Lyme arthritis and from 10 control subjects were tested for B burgdorferi DNA using 3 primer-probe sets that target genes encoding outer surface proteins A or B or a flagellar protein (P41) of the spirochete. RESULTS: The 26 patients with Lyme arthritis, who had received antibiotic therapy for a mean total duration of 8 weeks prior to synovectomy, and the 10 control subjects each had negative polymerase chain reaction (PCR) results in synovial samples. When the samples were spiked with approximately 1-10 B burgdorferi, all but 1 had positive PCR results, suggesting that spirochetal DNA could have been detected in most of the unspiked samples if it had been present. CONCLUSION: These results indicate that synovial inflammation may persist in some patients with Lyme arthritis after the apparent eradication of the spirochete from the joint with antibiotic therapy. 相似文献
67.
We have investigated the effects of mechanical elution of neutrophils from nylon-wool fiber (NWF) using the scanning electron microscope and biochemical analysis of elution fractions. We have determined that mechanical removal of neutrophils from nylon-wool fiber disrupts neutrophils adherent to nylon-wool fiber and augments release of granules, release of peripheral cytoplasmic fragments, and release of lactic dehydrogenase, a soluble cytoplasmic enzyme. Mechanical shearing of the adherent cell, and not adherence per se, causes the fragmentation. The extent of fragmentation is proportional to the NWF surface area available to neutrophils and is maximal at the temperature for optimal adherence and spreading. Agents that decrease cell spreading (n-ethylmaleimide and cold) diminish fragmentation. Cytochalasin B, an agent that destabilizes the neutrophil cortex, increases fragmentation. Fragmentation may be an important contributing cause of the abnormal morphology, function, and in vivo survival of nylon-wool-fiber procured human neutrophils. The prevention of fragmentation would appear to be necessary to insure the procurement of optimally functioning cells. Elution of NWF-adherent neutrophils in the cold might be a practical way to diminish neutrophil damage during clinical filtration leukapheresis. 相似文献
68.
Enhancement of chemotactic factor-stimulated neutrophil oxidative metabolism by leukotriene B4 总被引:4,自引:0,他引:4
Leukotriene B4 (LTB4) is a potent primary stimulator of neutrophil chemotaxis, aggregation, and degranulation and induces superoxide production at higher concentrations. In order to determine whether LTB4 modulates neutrophil responses to oxidative stimuli, human neutrophils (PMNs) were incubated with LTB4 prior to stimulation with f-Met-Leu-Phe (fMLP, 10(-7) mol/L), opsonized zymosan (OZ, 250 micrograms/mL), or phorbol myristate acetate (PMA, 32 nmol/L). Superoxide (O2-) production by stimulated PMNs was assessed by the superoxide dismutase-inhibitable reduction of cytochrome c. LTB4 alone did not stimulate O2- production in concentrations below 10(-7) mol/L and had no effect on the O2- assay. In the concentration range of 10(-12) to 10(-8) mol/L, LTB4 did not alter O2- release induced by OZ or PMA. In contrast, LTB4-treated cells demonstrated enhanced O2- production following exposure to fMLP, and in the presence of 10 nmol/LLTB4, generated 180% +/- 41% of O-2 quantities produced by control cells (n = 23). Enhancement was LTB4 dose-dependent, was maximal in the range of 1 to 10 nmol/L LTB4, was not reversed by removal of the lipid from the medium prior to fMLP stimulation, and was not dependent on the presence of Ca++ or Mg++ in the suspending medium. Chemiluminescence of fMLP-stimulated neutrophils was increased to 323% of controls in neutrophils preincubated with 10 nmol/L LTB4. Unlike augmentation of oxidative responses to fMLP seen with other degranulating stimuli, enhancement by LTB4 was not correlated with an increase in 3H-fMLP receptor binding. These results indicate that, in addition to its primary effects on neutrophil function, LTB4 modulates PMN oxidative responses to the chemotactic peptide and, thus, may amplify the release of oxygen metabolites at inflammatory foci. 相似文献
69.
In vivo expression of the B7 costimulatory molecule by subsets of antigen-presenting cells and the malignant cells of Hodgkin's disease 总被引:10,自引:0,他引:10
Munro JM; Freedman AS; Aster JC; Gribben JG; Lee NC; Rhynhart KK; Banchereau J; Nadler LM 《Blood》1994,83(3):793-798
The B-lymphocyte/accessory-cell activation antigen B7 (BB1) has been shown in vitro to stimulate T-lymphocyte proliferation and cytokine production via CD28 present on the latter cells. In this study, benign lymphoid tissues, lymphomas, and extralymphoid inflammatory sites were examined immunohistochemically using anti-B7 and other relevant monoclonal antibodies. B7 was expressed by benign transformed germinal center B cells, as it was by B cells of follicular lymphomas. B7 was also expressed by a subpopulation (a mean of 31% to 65%) of macrophages and dendritic cells in a variety of lymphoid tissues. It was present in abundance on all macrophages constituting sarcoid granulomas in lymph nodes. In extralymphoid inflammation, 17% to 35% of macrophages expressed B7 only weakly. Cases of Hodgkin's disease showed expression of B7 by the majority of Reed-Sternberg cells or malignant mononuclear variants, a phenomenon that potentially contributes to the lymphocytic accumulation that is a feature of this condition. CD28+ T cells were seen in all areas where T cells were present. B7+ and CD28+ cells colocalized in, for example, lymphoid follicles, lymph node paracortex, sarcoid granulomas, and Hodgkin's disease tissue, indicating a potential for cellular interaction via these molecules at these sites. 相似文献
70.
Normal synthesis and expression of endothelial IIb/IIIa in Glanzmann's thrombasthenia 总被引:2,自引:0,他引:2
Glanzmann's thrombasthenia is a bleeding disorder, inherited in an autosomal recessive way and characterized by an absence or deficiency of the platelet glycoprotein (GP) IIb/IIIa complex. Recently, we and others demonstrated that cultured human umbilical vein endothelial cells synthesized a membrane protein complex similar to the platelet GP IIb/IIIa complex. In this article, we demonstrate that endothelial cells isolated from the umbilical vein of a newborn with Glanzmann's thrombasthenia, as compared with normal endothelial cells, show no difference in their ability to synthesize and express this GP IIb/IIIa complex. Our results indicate that Glanzmann's thrombasthenia is not accompanied by an "endotheliopathy." 相似文献