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Pneumoniae Meningitis (pneumoniae + meningitis)
Kinds of Pneumoniae Meningitis Selected AbstractsMinimizing the release of proinflammatory and toxic bacterial products within the host: A promising approach to improve outcome in life-threatening infectionsFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 1 2005Roland Nau Abstract Various bacterial components (e.g., endotoxin, teichoic and lipoteichoic acids, peptidoglycans, DNA) induce or enhance inflammation by stimulating the innate immune system and/or are directly toxic in eukariotic cells (e.g., hemolysins). When antibiotics which inhibit bacterial protein synthesis kill bacteria, smaller quantities of proinflammatory or toxic compounds are released in vitro and in vivo than during killing of bacteria by ,-lactams and other cell-wall active drugs. In general, high antibiotic concentrations liberate lower quantities of bacterial proinflammatory or toxic compounds than concentrations close to the minimum inhibitory concentration. In animal models of Escherichia coli Pseudomonas aeruginosa and Staphylococcus aureus peritonitis/sepsis and of Streptococcus pneumoniae meningitis, a lower release of proinflammatory bacterial compounds was associated with a reduced mortality or neuronal injury. Pre-treatment with a bacterial protein synthesis inhibitor reduced the strong release of bacterial products usually observed during treatment with a ,-lactam antibiotic. Data available strongly encourage clinical trials comparing antibiotic regimens with different release of proinflammatory/toxic bacterial products. The benefit of the approach to reduce the liberation of bacterial products should be greatest in patients with a high bacterial load. [source] Increased neurogenesis after experimental Streptococcus pneumoniae meningitisJOURNAL OF NEUROSCIENCE RESEARCH, Issue 4 2003Joachim Gerber Abstract Neuronal damage in the hippocampal formation is a common feature in animal models of bacterial meningitis and human disease. In mouse and rabbit models of Streptococcus pneumoniae meningitis, proliferation of neural progenitor cells quantified by bromodeoxyuridine (BrdU) incorporation was enhanced in the subgranular layer of the dentate gyrus. In mice, the density of BrdU-labeled cells was maximal on Day 2 after infection. Approximately 60% of the cells labeled by BrdU between Days 7 and 10 after infection that remained present 28 days later had migrated into deeper layers of the dentate gyrus and differentiated into neurons, as evidenced by immunohistochemical staining for TUC-4, MAP-2 and beta-tubulin. This suggests that endogenous repair mechanisms may limit consequences of neuronal destruction after meningitis. © 2003 Wiley-Liss, Inc. [source] Cochlear Preservation After Meningitis: An Animal Model Confirmation of Adjunctive Steroid Therapy,THE LARYNGOSCOPE, Issue 2 2006John Addison MA Abstract Objective/Hypothesis: The objective of the present study was to determine whether treating pneumococcal meningitis with a combined antibiotic and steroid regime will prevent cochlear damage, a common pneumococcal meningitis side effect. Study Design: This was a prospective animal study. Methods: Gerbils were randomly assigned to three experimental groups. Animals in group 1, the control animals, received intrathecal saline injections. Animals in groups 2 and 3 received intrathecal injections of Streptococcus pneumoniae to induce meningitis. Although group 2 solely was treated for 7 days with intraperitoneal penicillin injections (48,0000 units), group 3 received, in addition to the antibiotic for 4 days, 0.5 mg/kg intraperitoneal dexamethasone injections. Three months after the meningitis was induced, the animals' cochlear function was determined using auditory brainstem responses (ABRs). Fifteen frequencies were tested, five octaves at three steps per octave between 2 and 50 kHz. Results: ABR thresholds were significantly elevated only in group 2. When compared with group 1, ABR thresholds were 19 dB higher (P < .05). Frequencies at the low-frequency end of the hearing range were affected more than the midfrequencies. Animals that received dexamethasone had 2-dB higher thresholds than the control group (P > .05). Conclusions: Dexamethasone therapy in conjunction with antibiotic therapy preserves cochlear function in cases of S. pneumoniae meningitis in the Mongolian gerbil model. [source] Transcriptional Regulation of Caspases in Experimental Pneumococcal MeningitisBRAIN PATHOLOGY, Issue 3 2001Matthias von Mering Apoptosis and necrosis in brain account for neurological sequelae in survivors of bacterial meningitis. In meningitis, several mechanisms may trigger death pathways leading to activation of transcription factors regulating caspases mRNA synthesis. Therefore, we used a multiprobe RNA protection assay (RPA) to examine the expression of 9 caspase-mRNA in the course of experimental Streptococcus pneumoniae meningitis in mouse brain. Caspase-6, -7 and -11 mRNA were elevated 6 hours after infection. 12 hours after infection caspases-1, -2, -8 and -12 mRNA rose. Caspase-14 mRNA was elevated 18 h and caspase-3 mRNA 24 h after infection. In situ hybridization detected caspases-3, -8, -11 and -12 mRNA in neurons of the hippocampal formation and neocortex. Development of sepsis was paralleled by increased transcription of caspases mRNA in the spleen. In TNF,-deficient mice all caspases examined were less upregulated, in TNF-receptor 1/2 knockout mice caspases-1, -2, -7, -11 and -14 mRNA were increased compared to infected control animals. In caspase-1 deficient mice, caspases-11, and -12 mRNA levels did not rise in meningitis indicating the necessity of caspase-1 activating these caspases. Hippocampal formations of newborn mice incubated with heat-inactivated S. pneumoniae R6 showed upregulation of caspase-1, -3, -11 and -12 mRNA. These observations suggest a tightly regulated caspases network at the transcriptional level in addition to the known cascade at the protein level. [source] Uveitis associated with Mycoplasma pneumoniae meningitisACTA OPHTHALMOLOGICA, Issue 1 2001Sharam S. Yashar [source] | ||||||||||