Objectives: To determine the effect of amoxicillin treatment on resistance selection in patients with communityacquired lower respiratory tract infections in a randomized, placebo-controlled trial.Methods: Patients were prescribed amoxicillin 1 g, three times daily (n ¼ 52) or placebo (n ¼ 50) for 7 days. Oropharyngeal swabs obtained before, within 48 h post-treatment and at 28 -35 days were assessed for proportions of amoxicillin-resistant (ARS; amoxicillin MIC ≥2 mg/L) and -non-susceptible (ANS; MIC ≥0.5 mg/L) streptococci. Alterations in amoxicillin MICs and in penicillin-binding-proteins were also investigated. ITT and PP analyses were conducted.Results: ARS and ANS proportions increased 11-and 2.5-fold, respectively, within 48 h post-amoxicillin treatment compared with placebo [ARS mean increase (MI) 9.46, 95% CI 5.57-13.35; ANS MI 39.87, 95% CI 30.96-48.78; P,0.0001 for both]. However, these differences were no longer significant at days 28-35 (ARS MI 23.06, 95% CI 27.34 to 1.21; ANS MI 4.91, 95% CI 24.79 to 14.62; P.0.1588). ARS/ANS were grouped by pbp mutations. Group 1 strains exhibited significantly lower amoxicillin resistance (mean MIC 2.8 mg/L, 95% CI 2.6-3.1) than group 2 (mean MIC 9.3 mg/L, 95% CI 8.1-10.5; P,0.0001). Group 2 strains predominated immediately post-treatment (61.07%) and although decreased by days 28-35 (30.71%), proportions remained higher than baseline (18.70%; P¼0.0004).Conclusions: By utilizing oropharyngeal streptococci as model organisms this study provides the first prospective, experimental evidence that resistance selection in patients receiving amoxicillin is modest and short-lived, probably due to 'fitness costs' engendered by high-level resistance-conferring mutations. This evidence further supports European guidelines that recommend amoxicillin when an antibiotic is indicated for community-acquired lower respiratory tract infections.
Cerebral cavernous malformations, also known as cavernous angioma or cavernoma, are a type of vascular disorder. they consist of abnormally large vascular cavities or sinusoid channels of varying size. the majority of cavernous malformations in the brain are small and do not always present with symptoms. a minority of large cavernous malformations, known as giant cavernous malformations (GCm), can cause neurological symptoms (such as headaches, focal neurologic deficits and seizures), which are probably related to hemorrhage and mass effect. GCm grow steadily in size over time, due to repetitive episodes of bleeding. the purpose of this paper is to document two case reports of patients with GCm, illustrate the radiological appearance, discuss the neurosurgical consequences, and to provide a literature analysis.
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