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The study of aerosols including chemical analysis has been substan tially advanced after the development of aerodynamic focusing lenses. Test results of 2 such lenses are presented; 1 operating at pressures between 15 and 80 Torr and the other at higher pressures between 30 and 175 Torr. The lenses consist of 7 single orifices separated by spacers and contained in a tube of about 10 cm in length. Orifice diameters range from 1.40 to .25 mm, while the exit holes (nozzles) are smaller. Laminar gas flow within a lens produces a narrow particle beam which is directed into a vacuum chamber for analysis of beam width and position, aerosol transport efficiency, linearity, and other parameters. The lenses were tested both with spherical monodisperse oil particles (.34-4 mu m diameter) as well as nonspherical solid NaCl particles (.19-.85 mu m) simulating larger particles with lower density. Both lenses produce narrow aerosol beams with diameters smaller than 4 mm about 90 mm downstream of the nozzle. Although nonspherical particles broaden the aerosol beam by a factor of 2-4, this fact allows a distinction between liquid and solid nonspherical aerosols. Beam characteristics are well reproduced when lenses are dis- and reassembled. The transmission of aerosols through each of the 2 lenses is a nearly linear function of the pressure.Transmission efficiencies have been measured to be above 90%. [ABSTRACT FROM AUTHOR]

The aim of the present study was to assess the influence of a I-month period of chlorhexidine digluconate (CHX) rinses on the remodelling activity of periodontal tissues adjacent to an extraction wound. From 12 patients assigned to the test group rinsing 2 x daily with 15 ml of 0.12% CHX solution (Peridex®) starting 2 days after tooth extraction and from 11 patients assigned to the control group rinsing with a placebo solution, standardized radiographs were available taken immediately after tooth extraction and 1, 2, 3 and 6 months thereafter. Computer assisted densitometric image analysis (CADIA) was applied in order to quantify changes in density during the healing phase after tooth extraction. Regions of interest (ROl) were chosen for CADIA covering supracrestal periodontal soft tissue adjacent to the extraction wound. ROIs were also defined on crestal alveolar bone adjacent to the extraction wound. In the active group, 15/20 sites demonstrated an increase in alveolar bone density between months 1 and 6 (mean CADIA value 6.7±10.0), whereas in the control group 11/21 sites demonstrated a loss in density (mean CADIA values - 1.4 ± 10.5). Similar observations were made when the ROIs covering supracrestal periodontal tissues were analyzed (mean CADIA values 7.8 ± 8.4 for the experimental group and -0.3 ± 10.5 for the control group). These differences were statistically significant (p <0.04). The digitized series of standardized radiographs were also evaluated for changes in bone height. The distances from the alveolar bone crest to reference points were measured in mm within the baseline: the 1, 2, 3 and 6 month radiographs. Whereas the control group rinsing with a placebo solution lost almost 1 mm of bone height over 6 months after tooth extraction, it was obvious that in the patients rinsing with the CHX solution, the crestal alveolar bone level was maintained. It was concluded that the administration of 0.12% chlorhexidine rinses for 1 month following tooth extraction resulted in a beneficial healing effect on the periodontal conditions of teeth adjacent to the extraction site. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate the effects of a 1-month period of chlorhexidine (CMX) rinses on the periodontal conditions of teeth adjacent to extraction sockets. 40 patients signed consent forms for this double blind trial and were randomly assigned to either the test group rinsing 2 × daily with 15 ml of a 0.12% CHX solution (Peridex®) starting 2 days after tooth extraction or the control group rinsing with a placebo solution for 30 days. Clinical periodontal parameters were obtained from test sites located adjacent to as well as matched controls distant to the extraction sites. The measurements were performed at baseline before the extraction and 1, 2, 3 and 6 months thereafter. During the observation period, the patients were exposed to initial periodontal therapy. The test sites of the group rinsing with CHX demonstrated significantly reduced (p < 0.05) plaque indices, gingival indices and lower %s of sites bleeding on probing one month following the extraction. The test sites of the control group rinsing with the placebo demonstrated a tendency for loss of clinical attachment between 1 and 2 months after the tooth extraction. The mean pocket probing depth (PPD) at test sites of the CHX rinsing group was smaller than in the placebo rinsing group at the one month examination. Also, the mean PPD of the test sites in the CHX group was significantly smaller than at the control sites at 1 month. This difference was not observed in the control group rinsing with placebo. Due to the effect of initial periodontal therapy, the differences in the clinical parameters were no longer statistically significant at six months. It is concluded that the administration of 0.12% CHX rinses following tooth extraction results in a significant improvement of the periodontal conditions adjacent to extraction sockets and hence, should be recommended routinely. [ABSTRACT FROM AUTHOR]

Procalcitonin (PCT)-guided antibiotic stewardship is a successful strategy to decrease antibiotic use. We assessed if clinical judgement affected compliance with a PCT-algorithm for antibiotic prescribing in a multicenter surveillance of patients with lower respiratory tract infections (LRTI). Initiation and duration of antibiotic therapy, adherence to a PCT algorithm and outcome were monitored in consecutive adults with LRTI who were enrolled in a prospective observational quality control. We correlated initial clinical judgment of the treating physician with algorithm compliance and assessed the influence of PCT on the final decision to initiate antibiotic therapy. PCT levels correlated with physicians' estimates of the likelihood of bacterial infection ( p for trend <0.02). PCT influenced the post-test probability of antibiotic initiation with a greater effect in patients with non-pneumonia LRTI (e.g., for bronchitis: −23 % if PCT ≤ 0.25 μg/L and +31 % if PCT > 0.25 μg/L), in European centers (e.g., in France −22 % if PCT ≤ 0.25 μg/L and +13 % if PCT > 0.25 μg/L) and in centers, which had previous experience with the PCT-algorithm (−16 % if PCT ≤ 0.25 μg/L and +19 % if PCT > 0.25 μg/L). Algorithm non-compliance, i.e. antibiotic prescribing despite low PCT-levels, was independently predicted by the likelihood of a bacterial infection as judged by the treating physician. Compliance was significantly associated with identification of a bacterial etiology ( p = 0.01). Compliance with PCT-guided antibiotic stewardship was affected by geographically and culturally-influenced subjective clinical judgment. Initiation of antibiotic therapy was altered by PCT levels. Differential compliance with antibiotic stewardship efforts contributes to geographical differences in antibiotic prescribing habits and potentially influences antibiotic resistance rates. [ABSTRACT FROM AUTHOR]

Context: In previous smaller trials, a procalcitonin (PCT) algorithm reduced antibiotic use in patients with lower respiratory tract infections (LRTIs).Objective: To examine whether a PCT algorithm can reduce antibiotic exposure without increasing the risk for serious adverse outcomes.Design, Setting, and Patients: A multicenter, noninferiority, randomized controlled trial in emergency departments of 6 tertiary care hospitals in Switzerland with an open intervention of 1359 patients with mostly severe LRTIs randomized between October 2006 and March 2008.Intervention: Patients were randomized to administration of antibiotics based on a PCT algorithm with predefined cutoff ranges for initiating or stopping antibiotics (PCT group) or according to standard guidelines (control group). Serum PCT was measured locally in each hospital and instructions were Web-based.Main Outcome Measures: Noninferiority of the composite adverse outcomes of death, intensive care unit admission, disease-specific complications, or recurrent infection requiring antibiotic treatment within 30 days, with a predefined noninferiority boundary of 7.5%; and antibiotic exposure and adverse effects from antibiotics.Results: The rate of overall adverse outcomes was similar in the PCT and control groups (15.4% [n = 103] vs 18.9% [n = 130]; difference, -3.5%; 95% CI, -7.6% to 0.4%). The mean duration of antibiotics exposure in the PCT vs control groups was lower in all patients (5.7 vs 8.7 days; relative change, -34.8%; 95% CI, -40.3% to -28.7%) and in the subgroups of patients with community-acquired pneumonia (n = 925, 7.2 vs 10.7 days; -32.4%; 95% CI, -37.6% to -26.9%), exacerbation of chronic obstructive pulmonary disease (n = 228, 2.5 vs 5.1 days; -50.4%; 95% CI, -64.0% to -34.0%), and acute bronchitis (n = 151, 1.0 vs 2.8 days; -65.0%; 95% CI, -84.7% to -37.5%). Antibiotic-associated adverse effects were less frequent in the PCT group (19.8% [n = 133] vs 28.1% [n = 193]; difference, -8.2%; 95% CI, -12.7% to -3.7%).Conclusion: In patients with LRTIs, a strategy of PCT guidance compared with standard guidelines resulted in similar rates of adverse outcomes, as well as lower rates of antibiotic exposure and antibiotic-associated adverse effects.Trial Registration: isrctn.org Identifier: ISRCTN95122877. [ABSTRACT FROM AUTHOR]