Treatment of displaced supracondylar humeral fractures among children: Crossed versus lateral pinning

This retrospective study evaluated different pinning configurations used in the treatment of displaced supracondylar humeral fractures among children, mainly regarding maintenance of fracture reduction and avoidance of complications. The fractures (41 type II and 67 type III) of 108 children (mean age 6.48 years) were treated by closed reduction and percutaneous pinning: 37 with crossed pins, 37 with two lateral pins and 34 with two lateral and one medial pin. Mean follow-up period was 7.4 months. Type III fractures fixed by two lateral pins were found significantly prone to postoperative instability, late complications and need for medial pin fixation. There was a significant relation between either delay to surgery or postoperative instability and occurrence of complications. Final outcome was significantly poorer in type III than in type II fractures. Fixation by two lateral pins only is not recommended for treating type III supracondylar humeral fractures, but could be used initially to fix severely unstable fractures to allow extension of the elbow before inserting a medial pin. Every effort should be made to avoid iatrogenic ulnar nerve injury while inserting the medial pin.     

A Mycobacterium tuberculosis cluster demonstrating the use of genotyping in urban tuberculosis control

Background  

DNA fingerprinting of Mycobacterium tuberculosis isolates offers better opportunities to study links between tuberculosis (TB) cases and can highlight relevant issues in urban TB control in low-endemic countries.     

[18F]Fallypride dopamine D2 receptor studies using delayed microPET scans and a modified Logan plot

[¹⁸F]Fallypride PET studies can be used to estimate the nondisplaceable binding potential (BP_ND) in vivo of dopamine D2/D3 receptor-rich regions of the brain. These studies often take considerable time, up to ≥2 h, limiting the throughput. In this work, we investigated whether limited-duration scans performed subsequent to tracer administration yielded stable BP_ND estimates. In particular, we applied a modified version of the Logan plot method on the last 60 min of 120-min data and compared the results to those from analysis of the full data set.MethodsFourteen male Sprague-Dawley rats were injected with [¹⁸F]fallypride intravenously while under isoflurane anesthesia, and dynamic data were acquired on the microPET Focus 220 scanner for 120 min. The distribution volume ratio (DVR=BP_ND+1) was calculated from a Logan plot using 120 min of data and from a modified version using only the last 60 min. Three of these rats were imaged again on a second day to test the reproducibility. A two-tissue compartment model also was used to fit the time–activity curves (TACs) of the 120-min scans to estimate the parameters K₁, k₂, k_on, k₄ and B_max. These parameters were then used to simulate similar TACs while changing k_on to reflect changes in the dopaminergic system. The simulated TACs were used as a means for exploring the differences in DVR estimates between the last 60 min only and the full 120 min of simulated data.ResultsThe average DVR from the full 120-min scans was 13.8±0.9, whereas the average DVR estimated from only the last 60 min of data (DVR′) was 16.3±1.0. The DVR estimates showed good reproducibility in the three rats (mean DVR=13.8±1.5 on Day 1 and DVR=13.8±0.9 on Day 2). The simulations showed that the relationship between DVR′ and DVR estimates follows a semilinear form with varying k_on.ConclusionAlthough the BP_ND estimates are slightly overestimated in a delayed scan mode (i.e., no initial radiotracer uptake measurements) compared to a full scan, this overestimation depends primarily on k₃ (≈k_on×B_max) and has been evaluated in this work for a wide range of k_on values using simulated TACs. In particular, the sensitivity of DVR′ to changes in k_on is similar to that of DVR. This method of delayed scans eliminates the necessity of imaging during the initial uptake of the radiotracer and, thus, can be used to increase the throughput of studies.     

Intracranial tumors in first year of life: the CHEO experience

Introduction  

One seventh of pediatric brain tumors are diagnosed in the first year of life. With more widespread and accessible neuroimaging, these lesions are being diagnosed earlier, but there remains scant literature about their natural history.     

Synthesis and anti-hepatitis B activity of new substituted uracil and thiouracil glycosides

A number of N- and S-substituted uracil and thiouracil glycosides were synthesized by coupling reaction of 5,6-dibenzyle pyrimidine derivatives with the corresponding acetobromosugar. The synthesized compounds were tested for their antiviral activity against hepatitis B virus. Plaque reduction infectivity assay was used to determine virus count reduction as a result of treatment with tested compounds which showed moderate to high antiviral activities.