Lifetime risks, incubation period, and serial interval of tuberculosis

The lifetime risk of developing disease, the incubation period, and the time period between infection and transmission (the serial interval) are three important measures for interpreting trends in tuberculous infection and disease but are complicated by strong age dependencies regarding disease risk and by the potential for reinfection to occur. By using a model of the epidemiology of tuberculosis in England and Wales, the authors demonstrated that all three measures changed dramatically during the 20th century largely as a result of declines in the risk of infection. The estimated lifetime risk was highest following infection in early adulthood and declined with year of infection; the age-weighted average was approximately 12% during the last 50 years. Incubation period distributions depend on whether they are viewed prospectively (from infection to disease onset) or retrospectively (since infection for cases with disease onset at a particular time). As children rarely develop infectious forms of tuberculosis, infections acquired in childhood are associated with considerably longer serial intervals than those acquired in adulthood. These unusual properties are probably shared by other infections with long intervals between infection and disease. The results are important for interpreting data on transmission patterns, as are now being derived from molecular epidemiologic studies.     

Comparison Among Children with Children with Autism Spectrum Disorder, Nonverbal Learning Disorder and Typically Developing Children on Measures of Executive Functioning

It has been suggested that children with nonverbal learning disabilities (NLD) or Asperger’s Syndrome (AS) may show difficulties with executive functioning. There were 3 groups in this study who completed a neuropsychological battery of visual-spatial, executive functioning, and reasoning tasks; AS (n = 37), NLD (n = 31), and controls (n = 40). Results indicated that children in both clinical groups scored within average limits on measures of spatial reasoning and verbal ability. Fluid reasoning was also found to be within average ranges for all groups. The AS group experienced significant problems with cognitive flexibility compared to the other two groups. In contrast the NLD group showed fewer difficulties with cognitive flexibility but more problems with visual sequencing. These findings suggest that performance on executive function measures for children with AS or NLD is remarkably similar with subtle differences present.     

Kidney retransplantation in children following rejection and recurrent disease

Retransplantation accounts for approximately 15 % of the annual transplants performed in the USA, and in the recent International Collaborative Transplant Study report on pediatric patients 15.2 % of the 9209 patients included in the report were retransplant recipients. Although the significant advances in clinical management and newer immunosuppressive agents have had a significant impact on improving short-term allograft function, it is apparent that long-term allograft function remains suboptimal. Therefore, it is likely that the majority of pediatric renal allograft recipients will require one or more retransplants during their lifetime. Unfortunately, a second or subsequent graft in pediatric recipients has inferior long-term graft survival rates compared to initial grafts, with decreasing rates with each subsequent graft. Multiple issues influence the outcome of retransplantation, with the most significant being the cause of the prior transplant failure. Non-adherence-associated graft loss poses unresolved ethical issues that may impact access to retransplantation. Graft nephrectomy prior to retransplantation may benefit selected patients, but the impact of an in situ failed graft on the development of panel-reactive antibodies remains to be definitively determined. It is important that these and other factors discussed in this review be taken into consideration during the counseling of families on the optimal approach for their child who requires a retransplant.     

Quantifying continuous-flow dielectrophoretic trapping of cells and micro-particles on micro-electrode array

An interdigitated electrode array embedded within a micro-channel with forced flow is shown to enable dielectrophoretic (DEP) characterization of particles and/or cells based on measurements of their trapping percentage over a continuous frequency range. A simplified model of the trapping percentage, using spatial averaging of the convective and DEP force, linearly correlated it to the effective DEP force (in its positive mode). Thus, the Clausius–Mossotti factor was fitted to the experimental data, yielding effective electrical characteristics of the particles and/or cells. Also, the generated trapping percentage curve response over a continuous range of frequencies facilitates sorting and detection based on differences other than just the cross-over frequencies.