Intra-renal reflux: a new cause of medullary hyperechogenicity?

A 5-month-old infant with untreated severe urinary tract infection and bilateral vesico-ureteral reflux, had diffuse intrarenal reflux and hyperechogenicity of the medulla of two normal sized kidneys. We discuss the hyperechogenicity of the medulla in relationship to the intrarenal reflux.     

Procalcitonin in preoperative diagnosis of abdominal sepsis

Background and aims The present study attempted to identify the diagnostic significance of procalcitonin (PCT) in acute abdominal conditions as well as the range of concentrations relating to diagnosis of abdominal sepsis. Materials and methods This was prospective clinical study. The study included 98 consecutive patients with acute abdominal conditions, divided in sepsis and systemic inflammatory response syndrome (SIRS) group. Results PCT concentrations on admission were significantly higher in the sepsis group than in the SIRS group (median [interquartile range] 2.32 [7.41] vs 0.45 ng/ml [2.62]). A cutoff value of 1.1 ng/ml yielded 72.4% sensitivity and 62.5% specificity. In a group of patients with abdominal symptoms lasting for more than 24 h, a cut-off value of 1.1 ng/ml yielded higher sensitivity (82.9%) and higher specificity (77.3%). Conclusion Our results suggest that PCT measurements may be useful for early, preoperative diagnosis of abdominal sepsis.     

Impact of selective decontamination of the digestive tract on fungal carriage and infection: systematic review of randomized controlled trials

Objective To determine the impact of the antifungal component of selective decontamination of the digestive tract on fungal carriage, infection and fungaemia.Design Meta-analysis of randomized controlled trials of selective decontamination of the digestive tractStudy selection Data sources included Medline, Embase, Cochrane Register of Controlled Trials, previous meta-analyses, personal communications and conference proceedings, without restriction of language or publication status. All randomized trials were selected that compared oropharyngeal and/or intestinal administration of antifungals amphotericin B or nystatin, as part of selective decontamination protocol, with no treatment in the controls. There were 42 randomized controlled trials with a total of 6,075 critically ill patients.Methods Three reviewers independently applied selection criteria, performed quality assessment and extracted the data. The main outcome measures were patients with fungal carriage, patients with fungal infections and patients with fungaemia. Odds ratios were pooled with the random effect model.Measurements and results Enteral antifungals significantly reduced fungal carriage (odds ratio 0.32, 95% confidence interval 0.19–0.53) and overall fungal infections (0.30, 0.17–0.53). Fungaemia was not significantly reduced in the treatment group (0.89, 0.16–4.95).Conclusions Antifungals, as part of selective decontamination of the digestive tract, reduce fungal carriage and infection but not fungaemia in critically ill patients and may justify the inclusion of an antifungal component in the decontamination protocol.Electronic Supplementary Material Electronic supplementary material to this paper can be obtained by using the Springer Link server located at .     

Pharmacodynamic assessment of clarithromycin in a murine model of pneumococcal pneumonia

The pharmacodynamic profile of clarithromycin (CLR) was evaluated with a murine model of pneumonia. Eight Streptococcus pneumoniae isolates, including three macrolide-sensitive and five macrolide-resistant strains, were inoculated intratracheally into immunocompromised ICR mice as 10(8)-CFU bacterial suspensions. Orally administered CLR daily doses ranging from 5 to 600 mg/kg of body weight were given over 5 days, during which animal survival was monitored. The bacterial density in lung tissues was examined after 24 h of CLR treatment and in control groups. Pharmacokinetic analysis of CLR in mice demonstrated that the regimen of 150 mg/kg twice a day was representative of human pharmacokinetics and was used to compare the efficacy of CLR against sensitive and resistant S. pneumoniae strains. Immunocompetent CBA/J mice were also infected and treated as described above and evaluated for bacterial density and survival to assess the effect of the presence of leukocytes. All three pharmacodynamic parameters, the duration (percent) of the time that serum CLR concentrations remain above the MIC (%T>MIC), the ratio of the area under the concentration-time curve from 0 to 24 h (AUC(0-24)) to the MIC, and the ratio of the maximum concentration of drug in serum to the MIC, were found to be closely correlated to CLR bacterial efficacy (P < 0.001). Furthermore, all parameters had close correlation to bacterial density (r(2) = 0.72 to 0.82), median survival (r(2) = 0.93 to 0.94), and total percent survival (r(2) = 0.91 to 0.92). These in vivo data suggest that the bacterial activity of CLR is closely correlated with all three parameters over a wide range of exposures and, as a consequence of parameter interdependency, AUC(0-24)/MIC is the most reasonable predictor of antibiotic efficacy. In this neutropenic pneumonia model, CLR was less efficacious against S. pneumoniae strains for which MICs were >or=4 microg/ml. However, the presence of leukocytes in the immunocompetent mice resulted in improved bactericidal activity, relative to that in the neutropenic animals, despite an MIC of 4 microg/ml.     

On-patient see-through augmented reality based on visual SLAM

Purpose

An augmented reality system to visualize a 3D preoperative anatomical model on intra-operative patient is proposed. The hardware requirement is commercial tablet-PC equipped with a camera. Thus, no external tracking device nor artificial landmarks on the patient are required.

Methods

We resort to visual SLAM to provide markerless real-time tablet-PC camera location with respect to the patient. The preoperative model is registered with respect to the patient through 4–6 anchor points. The anchors correspond to anatomical references selected on the tablet-PC screen at the beginning of the procedure.

Results

Accurate and real-time preoperative model alignment (approximately 5-mm mean FRE and TRE) was achieved, even when anchors were not visible in the current field of view. The system has been experimentally validated on human volunteers, in vivo pigs and a phantom.

Conclusions

The proposed system can be smoothly integrated into the surgical workflow because it: (1) operates in real time, (2) requires minimal additional hardware only a tablet-PC with camera, (3) is robust to occlusion, (4) requires minimal interaction from the medical staff.

     

Pharmacodynamic comparisons of antimicrobials against nosocomial isolates of escherichia coli, klebsiella pneumoniae, acinetobacter baumannii and pseudomonas aeruginosa from the MYSTIC surveillance program: the OPTAMA Program, South America 2002

The OPTAMA (Optimizing Pharmacodynamic Target Attainment using the MYSTIC [Meropenem Yearly Susceptibility Test Information Collection] Antibiogram) Program provides insight into the appropriate antibiotic options for empiric therapy for common nosocomial pathogens. In this report, South America is represented by Brazil, Colombia, Peru, and Venezuela. A 5000-subject Monte Carlo Simulation estimated pharmacodynamic target attainment for meropenem, imipenem, ceftazidime, cefepime, piperacillin/tazobactam, and ciprofloxacin against Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa. Pharmacokinetic parameter variability was derived from existing healthy volunteer data, and minimum inhibitory concentration (MIC) data came from the 2002 MYSTIC program. Piperacillin/tazobactam and ciprofloxacin displayed the lowest target attainment against all bacterial species (14% to 24% for A. baumannii, 26% to 37% for P. aeruginosa, and 48% to 66% for the Enterobacteriaceae). Overall, the carbapenems had the highest probabilities of attainment against the Enterobacteriaceae (98% to 100%) and A. baumannii (73% to 74%), whereas cefepime obtained the greatest target attainment against P. aeruginosa (65%). Because no single regimen had high target attainment against A. baumannii and P. aeruginosa, the use of combination therapy to treat these pathogens in South America may be justified. Because of the lack of agreement with percent susceptibility for certain antimicrobial regimens, the use of pharmacodynamic target attainment may be a more accurate predictor of microbiologic success.     

Pharmacodynamic assessment of cefprozil against Streptococcus pneumoniae: implications for breakpoint determinations

Cefprozil, an oral semisynthetic cephalosporin, is commonly utilized in the treatment of respiratory-tract infections in children. While this agent has provided acceptable clinical success over a number of years, this study was undertaken to better define its pharmacodynamic profile against Streptococcus pneumoniae. Nineteen clinical isolates of S. pneumoniae were utilized in the neutropenic murine thigh infection model. To simulate the pharmacokinetic profile of cefprozil in children, the renal function of mice was impaired with uranyl nitrate, and a commercially available cefprozil suspension (6 mg/kg of body weight) was administered orally every 12 h. Mice were infected with 10(6) to 10(7) CFU per thigh, and therapy was initiated 2 h later. At 0 and 24 h postinfection, thighs were harvested to determine bacterial density. Survival was assessed during 96 h of therapy. The magnitude of bacterial kill ranged from 0.5 to 4.4 log(10) CFU per thigh over 24 h, and the extent of microbial eradication was dependent on the MIC. Killing of more than 2.6 log(10) CFU per thigh was observed with MICs of < or =3 microg/ml, while either minimal killing or growth was detected with MICs of > or =4 microg/ml. Mortality in untreated control animals was 100%. Animals infected with strains for which the MICs were < or =2 microg/ml survived the infection, whereas MICs exceeding 2 microg/ml resulted in substantial mortality. These studies demonstrate the effectiveness of cefprozil against isolates of the pneumococcus for which the MICs are < or =2 microg/ml using a drug exposure typically observed in children. These data support a susceptibility breakpoint of < or =2 microg/ml for cefprozil.     

Oral bioavailability and pharmacokinetics of trovafloxacin in patients with AIDS

Trovafloxacin pharmacokinetics were evaluated in 12 subjects with AIDS. By using a randomized design, single 200-mg doses of oral trovafloxacin and intravenous alatrofloxacin were administered. The mean absolute bioavailability was 91%. The pharmacokinetics of trovafloxacin when administered orally as the active form or intravenously as the prodrug (alatrofloxacin) are not altered in subjects with AIDS compared to those in healthy adults.     

Reduced parasitemia observed with erythrocytes containing inositol hexaphosphate.

Chemicals entrapped in erythrocytes by hypotonic hemolysis can be assessed for possible antiparasitic activity both in vivo and in vitro, regardless of whether they are able to diffuse into erythrocytes readily. Inositol hexaphosphate, a highly charged compound, produced a dramatic lowering of the percentage of cells infected by Babesia microti in vivo and both B. microti and Plasmodium falciparum in vitro. Several possible mechanisms for this observation are discussed.