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To quantitate the host defenses of the rat peritoneal cavity, nonviable radiolabeled Escherichia coli were injected intraperitoneally and clearance, leukocyte influx, and phagocytosis were examined. Macrophages (MCs) were present initially and remained relatively constant in number. The polymorphonuclear leukocyte (PMN) response began at one to two hours and was maximal at 24 to 72 hours. A previously unidentified inoculum-dependent PMN response was defined. Clearance and phagocytosis were extremely rapid, and few (less than 3%) free bacteria were present after two hours. Phagocytic activity of MCs and PMNs was identical, but MCs were numerically predominant initially and thus accounted for the majority of early phagocytosis. Thus, MC phagocytosis and clearance represent the primary line of host peritoneal defenses. We hypothesize that the subsequent inoculum-dependent PMN response may have evolved to cope with those larger inocula for which this initial response is inadequate.  相似文献   
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The Thy-1 molecule on murine T lymphocytes has been suggested to play a role in cellular activation events leading to a variety of immunologic functions. We present evidence that this molecule may be involved in signals leading to the in vitro generation of cytotoxic T cells against several tumor cell lines used as stimulators in mixed tumor-lymphocyte culture. The presence of monoclonal antibody against a polymorphic determinant on the Thy-1 molecule markedly reduced the generation of cytotoxicity after three days of culture of murine splenocytes with stimulator tumor cells bearing low levels of Ia antigen. In contrast, no effect was seen when the stimulators were either allogeneic splenocytes, or a tumor cell line expressing large amounts of Ia. These results suggest that the Thy-1 molecule is critically involved in events leading to the generation of cytotoxic effectors under some, but not all conditions.  相似文献   
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The most advantageous combination of immunosuppressive agents for cardiac transplant recipients has not yet been established. Between November 2001 and June 2003, 343 de novo cardiac transplant recipients were randomized to receive steroids and either tacrolimus (TAC) + sirolimus (SRL), TAC + mycophenolate mofetil (MMF) or cyclosporine (CYA) + MMF. Antilymphocyte induction therapy was allowed for up to 5 days. The primary endpoint of >/=3A rejection or hemodynamic compromise rejection requiring treatment showed no significant difference at 6 months (TAC/MMF 22.4%, TAC/SRL 24.3%, CYA/MMF 31.6%, p = 0.271) and 1 year (p = 0.056), but it was significantly lower in the TAC/MMF group when compared only to the CYA/MMF group at 1 year (23.4% vs. 36.8%; p = 0.029). Differences in the incidence of any treated rejection were significant (TAC/SRL = 35%, TAC/MMF = 42%, CYA/MMF = 59%; p < 0.001), as were median levels of serum creatinine (TAC/SRL = 1.5 mg/dL, TAC/MMF = 1.3 mg/dL, CYA/MMF = 1.5 mg/dL; p = 0.032) and triglycerides (TAC/SRL = 162 mg/dL, TAC/MMF = 126 mg/dL, CYA/MMF = 154 mg/dL; p = 0.028). The TAC/SRL group encountered fewer viral infections but more fungal infections and impaired wound healing. These secondary endpoints suggest that the TAC/MMF combination appears to offer more advantages than TAC/SRL or CYA/MMF in cardiac transplant patients, including fewer >/=3A rejections or hemodynamic compromise rejections and an improved side-effect profile.  相似文献   
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Pyogenic infections of the central nervous system of dental origin are quite uncommon in industrialized countries. We report six cases with intracerebral (n=4) and intraspinal (n=2) infections treated in our hospital. The microbial pathogen was successfully isolated in all patients. Fusobacterium nucleatum as well as Streptococcus species were found in three cases. Bacillus species were identified in two patients. Actinomyces was the etiologic agent in one case. All patients suffered from dental pathologies, so that after clinical and radiological exclusion of other sources an oral focus was presumed. Therapeutic management consisted of an operative procedure in order to obtain decompression, as well as evacuation of the pus on the one hand, followed by targeted antibiotics on the other. Clinical improvement was achieved in all patients, with one patient lost to follow-up. On magnetic resonance tomography, the inflammatory changes also disappeared in all cases. We recommend that oral infection with recurrent bacteraemia should always be considered in the pathogenesis of the so-called “cryptic” intracerebral and intraspinal infections.  相似文献   
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