Peritonitis caused by Agrobacterium tumefaciens in a child on peritoneal dialysis.

Sir, Although peritonitis in patients with terminal renal failuretreated with peritoneal dialysis is most often caused by commonorganisms, many cases of peritonitis due to unusual pathogenshave also been reported. Here we present a case of peritonitiscaused by one such uncommon organism, Agrobacterium tumefaciens,in a girl with Jeune syndrome     

Longitudinal Assessment Design and Statistical Power for Detecting an Intervention Impact

In evaluating randomized control trials (RCTs), statistical power analyses are necessary to choose a sample size which strikes the balance between an insufficient and an excessive design, with the latter leading to misspent resources. With the growing popularity of using longitudinal data to evaluate RCTs, statistical power calculations have become more complex. Specifically, with repeated measures, the number and frequency of measurements per person additionally influence statistical power by determining the precision with which intra-individual change can be measured as well as the reliability with which inter-individual differences in change can be assessed. The application of growth mixture models has shown that the impact of universal interventions is often concentrated among a small group of individuals at the highest level of risk. General sample size calculations were consequently not sufficient to determine whether statistical power is adequate to detect the desired effect. Currently, little guidance exists to recommend a sufficient assessment design to evaluating intervention impact. To this end, Monte Carlo simulations are conducted to assess the statistical power and precision when manipulating study duration and assessment frequency. Estimates were extracted from a published evaluation of the proximal of the Good Behavior Game (GBG) on the developmental course of aggressive behavior. Results indicated that the number of time points and the frequency of assessments influence statistical power and precision. Recommendations for the assessment design of longitudinal studies are discussed.     

Brain SPECT thallium using cadmium zinc telluride: a first experience

A 70-year-old man underwent a thallium-201 brain SPECT in the work-up and characterization of a frontotemporal mass. SPECT images were performed on cadmium zinc telluride system during only 5 minutes and after the injection of only 2 mCi. Images demonstrated high thallium uptake in frontotemporal areas considered as a potential malignant tumor. Surgical removal confirmed the diagnosis of malignant glioblastoma. The thallium SPECT fast acquisition imaging on cadmium zinc telluride systems is feasible with reduced injected dose. This method allows a significantly decrease of patient radiation exposure without compromising the image quality. This initial experience needs to be confirmed and optimized in larger clinical studies.     

Comparative prognostic role of nighttime blood pressure and nondipping profile on renal outcomes

Different studies have addressed the predictive role of nighttime hemodynamics on cardiovascular and renal outcomes, although nocturnal blood pressure (BP) phenotypes (i.e. nondipping pattern and absolute nocturnal BP) have been found to be predictive of worse health outcomes. Furthermore, differences in both examined populations - ranging from healthy and younger subjects to those with overt cardiovascular disease - and study design (i.e. cross-sectional or longitudinal) make the interpretation of the suggested correlations difficult. Focusing on the kidney, we reviewed the literature addressing the impact of nocturnal BP phenotypes on renal outcomes in different populations by further dividing our search by study design. The evidence so far qualifies absolute nocturnal BP as a better predictor or determinant of kidney dysfunction as compared with the nondipping status. The magnitude of nocturnal hemodynamic load imposed at the glomerular level might be of higher prognostic value as compared with the integration of the pathophysiological mechanisms associated with impaired nocturnal BP variability. These findings underline the importance of nocturnal BP phenotypes, retrieved by ambulatory BP measurements, on age-dependent progressive kidney function decline and question whether, to what extent and in whom the reduced nocturnal BP or reverse nondipping BP profile to a normal pattern will be of benefit.     

Patterns of Functional Impairment and Their Change among Youth Served in Systems of Care: An Application of Latent Transition Analysis

This study describes patterns of youth functioning at intake and 6 months into services in systems of care and change in functioning profiles. Participants included 2,826 males and 1,335 females aged 5 to 18 at intake. Functional impairment was assessed at intake and 6 months. Latent class analysis was used to classify youth based on their functional impairment profiles, and latent class transition analysis was used to examine the conditional probabilities of transitions in class membership between intake and 6 months. Males and females enter services with distinct patterns of functional impairment. The majority of youth remained in their respective profiles. Transitions tended to be from a higher to a lower impairment class. Importantly, a small group of males and females transitioned from a low to a higher impairment class. Providers should note that gender differences existed in the nature of change in class membership over time.     

A comparison of girls' and boys' aggressive-disruptive behavior trajectories across elementary school: prediction to young adult antisocial outcomes

Multiple group analysis and general growth mixture modeling was used to determine whether aggressive- disruptive behavior trajectories during elementary school, and their association with young adulthood antisocial outcomes, vary by gender. Participants were assessed longitudinally beginning at age 6 as part of an evaluation of 2 school-based preventive programs. Two analogous trajectories were found for girls and boys: chronic high aggression- disruption (CHAD) and stable low aggression- disruption (LAD). A 3rd class of low moderate aggression- disruption (LMAD) for girls and increasing aggression- disruption (IAD) for boys also was found. Girls and boys in analogous CHAD classes did not differ in trajectory level and course, but girls in the CHAD and LAD classes had lower rates of antisocial outcomes than boys. Girls with the LMAD trajectory differed from boys with the IAD trajectory.