Amoxicillin concentrations in relation to beta-lactamase activity in sputum during exacerbations of chronic obstructive pulmonary disease

Background: Acute exacerbations of chronic obstructive pulmonary disease (COPD) are often treated with antibiotics. Theoretically, to be maximally effective, the antibiotic concentration at sites of infection should exceed the minimum inhibitory concentration at which 90% of the growth of potential pathogens is inhibited (MIC90). A previous study showed that most hospitalized COPD patients had sputum amoxicillin concentrations <MIC90 when treated with amoxicillin/clavulanic acid. Those with adequate sputum concentrations had better clinical outcomes. Low amoxicillin concentrations can be caused by beta-lactamase activity in the lungs. This study investigated whether patients with sputum amoxicillin concentrations <MIC90 had higher beta-lactamase activity in sputum than patients with a concentration ≥MIC90. Methods: In total, 23 patients hospitalized for acute exacerbations of COPD and treated with amoxicillin/clavulanic acid were included. Sputum and serum samples were collected at day 3 of treatment to determine beta-lactamase activity in sputum and amoxicillin concentrations in both sputum and serum. Results: We found no difference in beta-lactamase activity between patients with sputum amoxicillin concentrations <MIC90 and ≥MIC90 (P=0.79). Multivariate logistic regression analysis showed no significant relationship between beta-lactamase activity and sputum amoxicillin concentrations <MIC90 or ≥MIC90 (odds ratio 0.53; 95% confidence interval 0.23–1.2; P=0.13). Amoxicillin concentrations were <MIC90 in 78% of sputum samples and in 30% of serum samples. Conclusion: In patients treated with amoxicillin/clavulanic acid for an acute exacerbation of COPD, sputum beta-lactamase activity did not differ between those with sputum amoxicillin concentrations <MIC90 or ≥MIC90. The finding that the majority of patients had sputum amoxicillin concentrations <MIC90 suggests that current treatment with antibiotics for acute exacerbations of COPD should be optimized

Effect of schottky barrier alteration on the low-frequency noise of InP based HEMTs

For the first time the effect of increasing the Schottky barrier's Al content of InP-based InAlAs-InGaAs HEMTs from 48 to 60% on the low-frequency (LF) drain and gate current noise is investigated. It is shown that the LF gate current noise SIG(f) for the 60% case decreases by almost three decades, while the LF drain current noise S IDS(f) stays at the same level. From small coherence values, it can be concluded that drain and gate noise sources can be treated separately which facilitates the LF noise modeling of these HEMT

Correction:Variability and cost implications of three generations of the Roche LightCycler® 480

[This corrects the article DOI: 10.1371/journal.pone.0190847.]

Loss of skeletal muscle density during neoadjuvant chemotherapy in older women with advanced stage ovarian cancer is associated with postoperative complications

Objective: To assess the association between loss of lumbar skeletal muscle mass and density during neoadjuvant chemotherapy (NACT) and postoperative complications after interval cytoreductive surgery (CRS) in older patients with ovarian cancer. Materials and methods: This multicenter, retrospective cohort study included patients aged 70 years and older with primary advanced stage ovarian cancer (International Federation of Gynecology and Obstetrics stage III-IV), treated with NACT and interval CRS. Skeletal muscle mass and density were retrospectively assessed using Skeletal Muscle Index (SMI) and Muscle Attenuation (MA) on routinely made Computed Tomography scans before and after NACT. Loss of skeletal muscle mass or density was defined as >2% decrease per 100 days in SMI or MA during NACT. Results: In total, 111 patients were included. Loss of skeletal muscle density during NACT was associated with developing any postoperative complication ≤30 days after interval CRS both in univariable (Odds Ratio (OR) 3.69; 95% Confidence Interval (CI) 1.57–8.68) and in multivariable analysis adjusted for functional impairment and WHO performance status (OR 3.62; 95%CI 1.27–10.25). Loss of skeletal muscle density was also associated with infectious complications (OR 3.67; 95%CI 1.42–9.52) and unintended discontinuation of adjuvant chemotherapy (OR 5.07; 95%CI 1.41–18.19). Unlike loss of skeletal muscle density, loss of skeletal muscle mass showed no association with postoperative outcomes. Conclusion: In older patients with ovarian cancer, loss of skeletal muscle density during NACT is associated with worse postoperative outcomes. These results could add to perioperative risk assessment, guiding the decision to undergo surgery or the need for perioperative interventions

Optimization of Standard In-House 24-Locus Variable-Number Tandem-Repeat Typing for Mycobacterium tuberculosis and Its Direct Application to Clinical Material

Variable-number tandem-repeat (VNTR) typing with a panel of 24 loci is the current gold standard in the molecular typing of Mycobacterium tuberculosis complex isolates. However, because of technical problems, a part of the loci often cannot be amplified by multiplex PCRs. Therefore, a considerable number of single-locus PCRs have to be performed for the loci with missing results, which impairs the laboratory work flow. Therefore, the original in-house method described by Supply et al. in 2006 was reevaluated. We modified seven primers and the PCR master mixture and obtained a strongly optimized in-house 24-locus VNTR typing method. The percentage of instantly complete 24-locus VNTR patterns detected in the routine flow of typing activities increased to 84.7% from the 72.3% obtained with the typing conducted with the commercially available Genoscreen MIRU-VNTR typing kit. The analytical sensitivity of the optimized in-house method was assessed by serial dilutions of M. tuberculosis in bronchoalveolar lavage fluid. A 1: 10 dilution of the different strains tested was the lowest dilution for the detection of a complete 24-locus VNTR pattern. The optimized in-house 24-locus VNTR typing method will reduce the turnaround time of typing significantly and also the financial burden of these activities

Androgens and Development of Posttransplantation Diabetes Mellitus in Male Kidney Transplant Recipients:A Post Hoc Analysis of a Prospective Study

OBJECTIVE: Posttransplantation diabetes mellitus (PTDM) effects up to 30% of all kidney transplant recipients (KTR). Recent studies in mice found that sufficient androgen levels are necessary for β-cell health and adequate insulin secretion. This raises the question whether a similar relationship might be present in KTR. Hence, we hypothesized that dihydrotestosterone and testosterone are associated with the development of PTDM in male KTR. RESEARCH DESIGN AND METHODS: We conducted a post hoc analyses of a prospective single-center cohort study including adult male KTR with a functioning graft ≥1 year posttransplantation. Androgen levels were assessed by liquid chromatography-tandem mass spectrometry. Development of PTDM was defined according to the American Diabetes Association's criteria. RESULTS: We included 243 male KTR (aged 51 ± 14 years), with a median dihydrotestosterone 0.9 (0.7-1.3) nmol/L and testosterone of 12.1 (9.4-15.8) nmol/L. During 5.3 (3.7-5.8) years of follow-up, 28 KTR (11.5%) developed PTDM. A clear association was observed, as 15 (19%), 10 (12%), and 3 (4%) male KTR developed PTDM in the respective tertiles of dihydrotestosterone (P = 0.008). In Cox regression analyses, both dihydrotestosterone and testosterone as continuous variables were inversely associated with the risk to development PTDM, independent of glucose and HbA1c (hazard ratio [HR] 0.31 [95%CI 0.16-0.59], P < 0.001; and HR 0.32 [95%CI 0.15-0.68], P = 0.003, respectively). CONCLUSIONS: Our results suggest that low androgen levels are a novel potential modifiable risk factor for the development of PTDM in male KTR

No transfer of calibration between action and perception in learning a golf putting task

We assessed calibration of perception and action in the context of a golf putting task. Previous research has shown that right-handed novice golfers make rightward errors both in the perception of the perfect aiming line from the ball to the hole and in the putting action. Right-handed experts, however, produce accurate putting actions but tend to make leftward errors in perception. In two experiments, we examined whether these skill-related differences in directional error reflect transfer of calibration from action to perception. In the main experiment, three groups of right-handed novice participants followed a pretest, practice, posttest, retention test design. During the tests, directional error for the putting action and the perception of the perfect aiming line were determined. During practice, participants were provided only with verbal outcome feedback about directional error; one group trained perception and the second trained action, whereas the third group did not practice. Practice led to a relatively permanent annihilation of directional error, but these improvements in accuracy were specific to the trained task. Hence, no transfer of calibration occurred between perception and action. The findings are discussed within the two-visual-system model for perception and action, and implications for perceptual learning in action are raised