Moment-to-moment dynamics of ADHD behaviour in South African children

Background  

The behaviour of children with Attention-Deficit/Hyperactivity Disorder is characterized by low predictability of responding. Low behavioural predictability is one way of operationalizing intra-individual ADHD-related variability. ADHD-related variability may be caused by inefficient behavioural selection mechanisms linked to reinforcement and extinction, as suggested by the recently published dynamic developmental theory (DDT) of ADHD. DDT argues that ADHD is a basic neurobehavioural disorder, caused by dysfunctioning dopamine systems. For establishing ADHD as a neurobehavioural disorder, findings from studies conducted in Western countries should be replicated in other cultural populations. The present study replicated the study conducted in Norway, with children from the Limpopo province in the Republic of South Africa.     

Platelet monoamine oxidase activity in Down's syndrome

The activity of platelet monoamine oxidase in Down's syndrome cases was significantly lower than that of controls. This difference was found for both males and females, and with tyramine, tryptamine and β-phenethylamine as substrate. The K_m values of the monoamine oxidase towards tryptamine as substrate from controls and Down's syndrome patients were similar.     

Nitrogen dead space in heavy smokers aged 44-58 years

Functional and alveolar dead spaces for nitrogen (VDF and VDalv) were calculated in a population of 20 male and 20 female heavy smokers and compared to data from static and forced spirometry (functional residual capacity [FRC], residual volume [RV], lung clearance index [LCI] and volume of trapped gas [VTG]) obtained with the same multiple-breath nitrogen wash-out as the dead spaces, and to variables considered sensitive to small airways disease measured with a single-breath nitrogen elimination (closing volume in per cent of vital capacity [CV%], closing capacity in per cent of total lung capacity [CC%] and slope index [SI]). Both nitrogen dead spaces increased with tidal volume in smokers as well as in healthy non-smokers. The majority of smokers were outside the predicted mean +2 SD for VTG (75%), CC and VDalv (70%) and SI (65%). The following variables were less sensitive for disclosing abnormality: CV (55%), RV (53%), LCI (38%) and forced expired volume in the first second (FEV1, 33%). If high sensitivity is considered preferable in epidemiological studies, the nitrogen dead spaces are equally as sensitive as the better of earlier described tests, and significantly superior to LCI and FEV1. Being tests that measure alveolar distribution of inhaled gas, they are probably sensitive to small airways disease.     

Binding of lipopeptide to CD14 induces physical proximity of CD14, TLR2 and TLR1

Lipoproteins or lipopeptides (LP) are bacterial cell wall components detected by the innate immune system. For LP, it has been shown that TLR2 is the essential receptor in cellular activation. However, molecular mechanisms of LP recognition are not yet clear. We used a FLAG-labeled derivative of the synthetic lipopeptide N-palmitoyl-S-[2,3-bis(palmitoyloxy)-(2R,S)-propyl]-(R)-cysteinyl-seryl-(lysyl)(3)-lysine (Pam(3)CSK(4)) to study the roles of CD14, TLR2 and TLR1 in binding and signaling of LP and their molecular interactions in human cells. The activity of Pam(3)CSK(4)-FLAG was TLR2 dependent, whereas the binding was enabled by CD14, as evaluated by flow cytometry and confocal microscopy. Using FRET and FRAP imaging techniques to study molecular associations, we could show that after Pam(3)CSK(4)-FLAG binding, CD14 and Pam(3)CSK(4)-FLAG associate with TLR2 and TLR1, and TLR2 is targeted to a low-mobility complex. Thus, LP binding to CD14 is the first step in the LP recognition, inducing physical proximity of CD14 and LP with TLR2/TLR1 and formation of the TLR2 signaling complex.     

Can Parent Training Alter Parent Practice and Reduce Conduct Problems in Ethnic Minority Children? A Randomized Controlled Trial

A randomized prevention study for ethnic minority mothers assessed the intervention effects of Parent Management Training—Oregon Model (PMTO) on maternal parent practices and child behavior. Ninety-six mothers from Somalia and Pakistan and their children aged 3 to 9 years were randomized to PMTO or a wait-list condition (WLC). Assessments were carried out at the baseline and post-intervention, using standardized measures and a multi-agent approach. All analyses were based on the intention-to-treat principle. Analysis of covariance (ANCOVA) showed that PMTO was effective in enhancing parent practices, with a decrease in harsh discipline and an increase in positive parenting. Moreover, PMTO produced reductions in motherreported child conduct problems. The largest effect sizes were found among mothers who attended more than 50 % of the PMTO group sessions. Teacher reports showed, however, that there were no significant intervention effects on conduct problems and social competence in kindergarten or school. The results emphasize the importance and feasibility of offering PMTO to ethnic minority families.     

Long-term results after closed reduction of latedetected hip dislocation: 60 patients followed up to skeletal maturity

Background This retrospective study was undertaken because there is limited knowledge about the long-term results after closed reduction of late-detected hip dislocation. The aims were to evaluate the outcome after skeletal maturity and to find predictive factors for good and poor results.

Patients and methods The material included 60 patients (78 hips, 53 girls) treated during the period 1958-62. The primary treatment was skin traction for 36 (16-76) days. Closed reduction was performed in all hips except 4 that needed open reduction. The mean age at reduction was 20 (4-65) months. Hip spica plaster was worn for 9 (6-20) months. Within 3 years of the start of treatment, derotation femoral osteotomy was performed because of increased femoral anteversion in 35 patients. Later, 28 patients underwent additional surgery on the femur or acetabulum to improve femoral head coverage. Radiographs at the time of diagnosis and during follow-up to skeletal maturity were assessed. The average age of the patients at the most recent follow-up was 26 (15-42) years.

Results The femoral head coverage normalized during the primary treatment and then decreased somewhat during the remaining growth period. The dysplasia of the acetabulum improved markedly during the first year after reduction. It continued to improve, but to a much lesser degree, until 8-10 years of age. A satisfactory radiographic outcome at skeletal maturity (Severin grades I and II) was obtained in 63% of the hips. Early derotation osteotomy of the femur did not improve the outcome. Avascular necrosis of the femoral head occurred in 14% of the hips. Risk factors for unsatisfactory outcome at skeletal maturity were high initial dislocation, steep acetabulum 1 year after reduction, reduced femoral head coverage at age 8-10 years, and avascular necrosis.

Interpretation The specific risk factors and the radiographic outcome—with satisfactory long-term results in nearly two-thirds of the patients—would be valuable for comparison with outcome studies after more modern treatment regimes.     

A randomized study on migration of the Spectron EF and the Charnley flanged 40 cemented femoral components using radiostereometric analysis at 2 years

Background and purpose

We performed a randomized study to determine the migration patterns of the Spectron EF femoral stem and to compare them with those of the Charnley stem, which is regarded by many as the gold standard for comparison of implants due to its extensive documentation.

Patients and methods

150 patients with a mean age of 70 years were randomized, single-blinded, to receive either a cemented Charnley flanged 40 monoblock, stainless steel, vaquasheen surface femoral stem with a 22.2-mm head (n = 30) or a cemented Spectron EF modular, matte, straight, collared, cobalt-chrome femoral stem with a 28-mm femoral head and a roughened proximal third of the stem (n = 120). The patients were followed with repeated radiostereometric analysis for 2 years to assess migration.

Results

At 2 years, stem retroversion was 2.3° and 0.7° (p < 0.001) and posterior translation was 0.44 mm and 0.17 mm (p = 0.002) for the Charnley group (n = 26) and the Spectron EF group (n = 74), respectively. Subsidence was 0.26 mm for the Charnley and 0.20 mm for the Spectron EF (p = 0.5).

Interpretation

The Spectron EF femoral stem was more stable than the Charnley flanged 40 stem in our study when evaluated at 2 years. In a report from the Norwegian arthroplasty register, the Spectron EF stem had a higher revision rate due to aseptic loosening beyond 5 years than the Charnley. Initial stability is not invariably related to good long-term results. Our results emphasize the importance of prospective long-term follow-up of prosthetic implants in clinical trials and national registries and a stepwise introduction of implants.Femoral stem loosening in cemented total hip arthroplasty (THA) is a multifactorial process with different mechanisms (Gruen et al. 1979, Barrack 2000). Factors such as the material, design, and surface finish are of fundamental importance for the long-term performance of cemented femoral hip implants (Scheerlinck and Casteleyn 2006). The longevity of cemented femoral stems has been related to the quality, stability, and endurance of the bonding between stem and cement (Chang et al. 1998, Scheerlinck and Casteleyn 2006). Different femoral stem designs have been developed to obtain increased fixation at this interface, since debonding between the cement and stem is an important mechanism in the initiation of loosening (Jasty et al. 1991).The satin-finish Spectron femoral stem has been one of the best performing stems in the Swedish National Arthroplasty Register (Malchau et al. 2002). A modified, proximally roughened version of the Spectron stem, the Spectron EF (Smith and Nephew, Memphis, TN), was introduced in 1989 to enhance stem-cement bonding.The use of this implant gained increasing popularity, and in 2007 the Spectron EF stem used with the Reflection All-Poly acetabular cup (Smith and Nephew) was the most commonly used primary total hip prosthesis in Norway (Espehaug et al. 2009).The degree of migration during the first years after surgery has been shown to correlate with the long-term performance of joint prostheses (Kärrholm et al. 1994, Kobayashi et al. 1997). Radiostereometric analysis (RSA) allows the accurate measurement of implant movement and has been extensively used for measurement of the in vivo migration of implants (Kärrholm et al. 1997).An earlier prospective randomized study reported an increased revision rate of the Charnley stem compared to the satin-finished Spectron stem (Garellick et al. 1999). In the present randomized, controlled clinical trial we wanted to evaluate the early migration of the successor to this stem, the Spectron EF stem and to compare it to that of the Charnley stem using RSA. The null hypothesis was that the migration of the Spectron EF stem was equal to that of the Charnley prosthesis (DePuy International Ltd., Leeds, UK), which has the longest follow-up and the largest volume of documentation of implants used for primary total hip arthroplasty (Aamodt et al. 2004).     

Precision grip function after free toe transfer in children with hypoplastic digits.

Although toe-to-hand transfer has a defined role in the management of congenital hand deformities, it remains unclear how well children integrate the transferred digits into physiological grasping. We analysed fingertip forces in the precision grip of 13 patients when lifting a test object more than three years after free toe transfer for absent or hypoplastic digits. Clinically, most patients showed normal sensibility of transferred digits, but active motion and pinch strength were limited as compared to the normal hand. For the control of fingertip forces, two key features of the normal two-digit opposition grip were seen in all operated hands: adaptation of grip force to object weight and parallel coordination of lift and grip forces. These physiological grasping strategies developed independently of the patients' age at the time of operation, which ranged from one to 13 years. In four patients, we observed increased tangential load forces with the operated hand due to misalignments in the application of fingertips on the grasp surfaces. Such forces lead to increased grip force requirements on both fingers that may overload transferred digits with limited motor function. The need for optimal alignment of the grip axis during toe-transfer surgery is emphasised.     

Mediastinitis after coronary artery bypass grafting: the effect of vacuum‐assisted closure versus traditional closed drainage on survival and re‐infection rate

Mediastinitis is treated with either vacuum‐assisted closure (VAC) or traditional closed drainage (TCD) with irrigation. The aim of the study was to determine the effect of the two treatments on mortality and re‐infection rate in a source population, using 21 314 consecutive patients undergoing isolated coronary artery bypass grafting (CABG) from January 1997 to October 2010. Median observation time was 2·9 years in the VAC group and 8·0 years in the TCD group. The epidemiological design was of an exposed (VAC, n = 64) versus non‐exposed (TCD, n = 66) cohort with two endpoints: (1) mortality and (2) failure of sternal wound healing or re‐infection. The crude effect of treatment technique versus endpoint was estimated by univariate analysis. Stratification analysis by the Mantel–Haenszel method was performed to quantify confounders and to pinpoint effect modifiers. Adjustment for confounders was performed using Cox regression analysis. Mediastinitis was diagnosed 6–105 (median 14) days after primary operation in the VAC group and 13 (5–29) days in the TCD group. There was no difference between groups in long‐term survival. Failure of sternal wound healing or re‐infection occurred less frequently in the VAC group (6%) than in the TCD group (21%; relative risk = 0·29, 95% CI = 0·06–0·88, P = 0·01). There are concerns for increase in right ventricle rupture in VAC compared with TCD. There was no difference in survival after VAC therapy and TCD therapy of post‐CABG mediastinitis. Failure of sternal wound healing or re‐infection was more common after TCD therapy.