A Network Model of Resilience Factors for Adolescents with and without Exposure to Childhood Adversity

Resilience factors (RFs) help prevent mental health problems after childhood adversity (CA). RFs are known to be related, but it is currently unknown how their interrelations facilitate mental health. Here, we used network analysis to examine the interrelations between ten RFs in 14-year-old adolescents exposed ('CA'; n = 638) and not exposed to CA ('no-CA'; n = 501). We found that the degree to which RFs are assumed to enhance each other is higher in the no-CA compared to the CA group. Upon correction for general distress levels, the global RF connectivity also differed between the two groups. More specifically, in the no-CA network almost all RFs were positively interrelated and thus may enhance each other, whereas in the CA network some RFs were negatively interrelated and thus may hamper each other. Moreover, the CA group showed more direct connections between the RFs and current distress. Therefore, CA seems to influence how RFs relate to each other and to current distress, potentially leading to a dysfunctional RF system. Translational research could explore whether intervening on negative RF interrelations so that they turn positive and RFs can enhance each other, may alter 'RF-mental distress' relations, resulting in a lower risk for subsequent mental health problems.

Extended physical education in children aged 6-15 years was associated with improved academic achievement in boys

AIM

Physical activity (PA) has been associated with enhanced cognition, brain development and concentration. This study evaluated whether increased physical education (PE) improved academic achievement.

METHODS

We recruited 304 children (55% boys) from a Swedish school in Skane County in 1998-2002 when they were six to seven years of age and followed them through all nine mandatory school years. Their PE level was increased from 60 to 200 minutes per week, and their results were compared with 73 885 control children (51% boys) in the county who graduated in the same years and did the standard 60 minutes of PE per week. Their academic achievements were measured as their final grade scores and the proportion of students eligible for upper secondary school.

RESULTS

The eligibility for further education increased in the intervention boys by 6.8 percentage points and the mean grade score by 12.1 points, while in the control group as a whole, the eligibility rate decreased by 0.7 percentage points and the mean grade score increased by 1.7 points. No changes in eligibility rates or mean grade scores were seen in the intervention girls.

CONCLUSION

Increasing weekly PE over nine years was associated with improved academic achievement in boys.

Discriminatory CT-textural features in splenic infiltration of lymphoma versus splenomegaly in liver cirrhosis versus normal spleens in controls and evaluation of their role for longitudinal lymphoma monitoring

PURPOSE

To find CT-texture analysis (CTTA) features for the discrimination of splenomegaly due to diffuse lymphoma involvement and liver cirrhosis versus normal-sized spleens in controls and to assess their potential role for longitudinal lymphoma monitoring.

MATERIAL AND METHODS

We had retrospectively identified 74 subjects with diffuse splenic involvement due to lymphoma (n = 29) and liver cirrhosis (n = 30), and healthy controls (n = 15), who underwent contrast-enhanced abdominal CT between August 2013 and October 2017. CTTA evaluation included heterogeneity, intensity, average, deviation, skewness, entropy of co-occurrence, number non-uniformity (NGLDM) and entropy NGLDM. A greater than 50% reduction of spleen volume after chemotherapy was considered proof for splenic involvement.

RESULTS

There were significant differences of splenic CTTA-values before and after treatment of patients with lymphoma, including mean of entropy(p < .001), uniformity of average(p < .001), uniformity of deviation(p = .002) and entropy of skewness(p < .001). Significant differences of splenic CTTA-values in subjects with lymphoma vs. healthy controls were found for mean intensity(p < .001), mean average(p < .001), and entropy of deviation(p < .001). No significant differences in splenic CTTA-values were found in subjects with lymphoma that reached complete remission vs. controls. Splenic CTTA values mean intensity(p = .002) and mean average(p = .004) were significantly different between subjects with untreated lymphoma and subjects with liver cirrhosis. At end-of-treatment all lymphomas reached complete remission. Entropy/uniformity of heterogeneity(p < .001), mean intensity(p = .007), mean average (p = .007), uniformity of average(p = .008) and mean/entropy/uniformity of skewness(p = .001) measured at this time differed significantly from baseline.

CONCLUSIONS

CTTA features in subjects with splenomegaly due to lymphoma and liver cirrhosis differ significantly from those of healthy controls and can be also used for monitoring lymphoma treatment. Quantitative CTTA features may increase the accuracy of diagnosing causes of splenomegaly.

Relation between travel strategy and social organization of migrating birds with special consideration of formation flight in the northern bald ibis

A considerable proportion of the world's bird species undertake seasonal long-distance migrations. These journeys are energetically demanding. Two major behavioural means to reduce energy expenditure have been suggested: the use of thermal uplifts for a soaring-gliding migration style and travelling in echelon or V-shaped formation. Both strategies have immediate consequences for the social organization of the birds as they either cause large aggregations or require travelling in small and stable groups. Here, we first discuss those consequences, and second present an analysis of formation flight in a flock of northern bald ibis on their first southbound migration. We observe clear correlations between leading and trailing on the dyadic level but only a weak correlation on the individual level during independent flight and no convincing correlation during the human guided part of the migration. This pattern is suggestive of direct reciprocation as a means for establishing cooperation during formation flight. In general, we conclude that behavioural adaptations for dealing with physiological constraints on long-distance migrations either necessitate or ultimately foster formation of social groups with different characteristics. Patterns and social organization of birds travelling in groups have been elusive to study; however, new tracking technology-foremost lightweight GPS units-will provide more insights in the near future.This article is part of the themed issue 'Physiological determinants of social behaviour in animals'.

Chest CT texture analysis for response assessment in systemic sclerosis

PURPOSE

To evaluate the role of CT-textural features for monitoring lung involvement in subjects with systemic sclerosis(SSc) undergoing autologous stem cell transplantation(SCT) by comparison with semi-quantitative chest-CT, pulmonary function tests(PFT) and clinical parameters (modified Rodnan skin score[mRSS]).

METHODS

In a retrospective single centre analysis, we identified 23 consecutive subjects(11male) with SSc between 07/2005 and 11/2016 that underwent chest CTs before, 6 and 12 months post-SCT. Response to therapy was defined at 6 months after transplantation as stabilisation or improvement in FVC > 10% and DLCO_SB > 10%. CT-texture analysis(CTTA) including mean, entropy and uniformity were calculated.

RESULTS

PFT classified the subjects into responders(18/23;78%) and non-responders(5/23;22%). mRSS improved in responders from 28.46 ± 9.53 to 15.70 ± 10.07 6 months after auto-SCT(p = .001) whereas in non-responders no significant improvement was registered. Fibrosis score increased significantly(mean2.33 ± 1.23 vs.1.41 ± 0.78; p = .005) in non-responders after 6 and 12months. Significant lower mean intensity and entropy of skewness and higher uniformity of skewness was found in responders vs. non-responders at baseline. Significant changes in CTTA-parameters were found in both responders and non-responders at 6months and only in responders also at 12months post-SCT.

CONCLUSIONS

Changes in CT-textural features after SCT are associated with visual CT evaluation of SSc-related lung abnormalities, but complementary provide information about therapy-induced, structural pulmonary changes.

Time lapse AFM on vesicle formation from mixed lipid bilayers induced by the membrane-active peptide melittin

Melittin is a model system for the action of antimicrobial peptides which are potential candidates for novel antibiotics. We investigated the membrane lysis effect of melittin on phase-separated supported lipid bilayers (DOPC-DPPC) by atomic force microscopy. AFM images show that the peptide first forms defects at the interface between the two lipid phases and then degrades preferentially the liquid-phase DOPC-enriched domains. Vesicular structures of 10-20 nm radius were observed to form, suggesting a mixed carpet-toroidal model mechanism for the resolved action of melittin.

Frequency Selective Non-Linear Blending to Improve Image Quality in Liver CT

Purpose: To evaluate the effects of a new frequency selective non-linear blending (NLB) algorithm on the contrast resolution of liver CT with low intravascular concentration of iodine contrast. Materials and Methods: Our local ethics committee approved this retrospective study. The informed consent requirement was waived. CT exams of 25 patients (60 % female, mean age: 65 ± 16 years of age) with late phase CT scans of the liver were included as a model for poor intrahepatic vascular contrast enhancement. Optimal post-processing settings to enhance the contrast of hepatic vessels were determined. Outcome variables included signal-to-noise (SNR) and contrast-to-noise ratios (CNR) of hepatic vessels and SNR of liver parenchyma of standard and post-processed images. Image quality was quantified by two independent readers using Likert scales. Results: The post-processing settings for the visualization of hepatic vasculature were optimal at a center of 115HU, delta of 25HU, and slope of 5. Image noise was statistically indifferent between standard and post-processed images. The CNR between the hepatic vasculature (HV) and liver parenchyma could be significantly increased for liver veins (CNR_Standard 1.62 ± 1.10, CNR_NLB 3.6 ± 2.94, p = 0.0002) and portal veins (CNR_Standard 1.31 ± 0.85, CNR_NLB 2.42 ± 3.03, p = 0.046). The SNR of liver parenchyma was significantly higher on post-processed images (SNR_NLB 11.26 ± 3.16, SNR_Standard 8.85 ± 2.27, p = 0.008). The overall image quality and depiction of HV were significantly higher on post-processed images (NLB_DHV: 4 [3 - 4.75], S_tandardDHV: 2 [1.3 - 2.5], p = < 0.0001; _NLBIQ: 4 [4 - 4], _StandardIQ: 2 [2 - 3], p = < 0.0001). Conclusion: The use of a frequency selective non-linear blending algorithm increases the contrast resolution of liver CT and can improve the visibility of the hepatic vasculature in the setting of a low contrast ratio between vessels and the parenchyma. Key Points: • Using the new frequency selective non-linear blending algorithm is feasible in contrast-enhanced liver CT.• Optimal post-processing settings make it possible to significantly increase the contrast resolution of liver CT without affecting image noise.• Especially in low contrast CT images, the novel algorithm is capable of significantly increasing image quality. Citation Format: • Bongers MN, Bier G, Kloth C et al. Frequency Selective Non-Linear Blending to Improve Image Quality in Liver CT. Fortschr Röntgenstr 2016; 188: 1163 - 1168.

[Treatment of Osteochondral Lesions in the Ankle: A Guideline from the Group "Clinical Tissue Regeneration" of the German Society of Orthopaedics and Traumatology (DGOU)]

Background: Osteochondral lesions (OCL) of the ankle are a common cause of ankle pain. Although the precise pathophysiology has not been fully elucidated, it can be assumed that a variety of factors are responsible, mainly including traumatic events such as ankle sprains. Advances in arthroscopy and imaging techniques, in particular magnetic resonance imaging (MRI), have improved the possibilities for the diagnosis of OCLs of the ankle. Moreover, these technologies aim at developing new classification systems and modern treatment strategies. Material and Methods: This article is a review of the literature. Recommendations of the group "Clinical Tissue Regeneration" of the German Society of Orthopaedics and Traumatology (DGOU) for the treatment of OCLs of the ankle are presented. The review gives a concise overview on the results of clinical studies and discusses advantages and disadvantages of different treatment strategies. Results: Non-operative treatment shows good results for selected indications in children and adolescents, especially in early stages of osteochondritis dissecans (OCD). However, surgical treatment is usually indicated in OCLs in adolescents and adults, depending on the size and location of the lesion. Various arthroscopic and open procedures are frequently employed, including reattachment of the fragment, local debridement of the lesion with fragment removal and curettage of the lesion, bone marrow-stimulation by microfracture or microdrilling (antegrade or retrograde), and autologous matrix-induced chondrogenesis (AMIC®) - with or without reconstruction of a subchondral bone defect or cyst by autologous cancellous bone grafting. Isolated subchondral cysts with an intact cartilage surface can be treated by retrograde drilling and possibly additional retrograde bone grafting. For larger defects or as salvage procedure, osteochondral cylinder transplantation (OATS® or Mosaicplasty®) or matrix-induced autologous chondrocyte transplantation (MACT) are recommended. Transplantation of so-called (osteochondral) mega grafts, such as autologous bone grafts or allografts, are used for very large osteochondral defects that cannot be reconstructed otherwise. Implantation of the so-called "small metal implants" - such as HemiCAP Talus® - is reserved for selected cases after failed primary reconstruction. Corrective osteotomies are indicated in accompanying axial malalignments. Conclusions: There are several different treatment strategies for OCLs, but clinical studies are rare and evidence is limited. Therefore, interventional studies, e.g. randomised controlled trials (RCTs), but also observational studies, e.g. based on data of the Cartilage Registry of the German Society of Orthopaedics and Traumatology (www.knorpelregister-dgou.de), are needed and are recommended by the authors.

Autologous chondrocyte implantation (ACI) for cartilage defects of the knee: A guideline by the working group "Clinical Tissue Regeneration" of the German Society of Orthopaedics and Trauma (DGOU)

BACKGROUND

Autologous chondrocyte implantation (ACI) is an established and well-accepted procedure for the treatment of localised full-thickness cartilage defects of the knee.

METHODS

The present review of the working group "Clinical Tissue Regeneration" of the German Society of Orthopaedics and Trauma (DGOU) describes the biology and function of healthy articular cartilage, the present state of knowledge concerning therapeutic consequences of primary cartilage lesions and the suitable indication for ACI.

RESULTS

Based on best available scientific evidence, an indication for ACI is given for symptomatic cartilage defects starting from defect sizes of more than three to four square centimetres; in the case of young and active sports patients at 2.5cm(2), while advanced degenerative joint disease needs to be considered as the most important contraindication.

CONCLUSION

The present review gives a concise overview on important scientific background and the results of clinical studies and discusses the advantages and disadvantages of ACI.

LEVEL OF EVIDENCE

Non-systematic Review.

The associations of physical activity with fracture risk--a 7-year prospective controlled intervention study in 3534 children

SUMMARY

This is the first study indicating an association between gradually diminished risk of fractures and years of increased physical activity. Our results could imply great benefits not only for the individual but also for the healthcare burden and cost of society.

INTRODUCTION

Physical activity (PA) in childhood is associated with high bone mass and beneficial neuromuscular function. We investigate if increased PA also is associated with fracture risk.

METHODS

We registered fractures in 3534 children aged 6 to 8 years at study start for up to 7 years; 1339 with 40 min of moderate PA every school day (intervention) and 2195 with the Swedish standard curriculum of 60 min of PA per school week (controls). In a subsample of 264 children, we measured areal bone mineral density (aBMD; g/cm(2)) with dual-energy X-ray absorptiometry (femoral neck and total spine) and muscle strength (peak torque for knee extension and flexion; Nm) with computerized dynamometer at baseline and after 7 years. We estimated annual fracture incidence rate ratios (IRR) in the intervention group compared to the control group as well as changes in bone mass and muscle strength. Data is given as mean (95% CI).

RESULTS

The IRR of fractures decreased with each year of the PA intervention (r = -0.79; p = 0.04). During the seventh year, IRR was almost halved [IRR 0.52 (0.27, 1.01)]. The intervention group had a statistically significant greater gain in total spine aBMD with a mean group difference of 0.03 (0.00, 0.05) g/cm(2) and peak flexion torque 180° with a mean group difference of 5.0 (1.5, 8.6) Nm.

CONCLUSIONS

Increased PA is associated with decreased fracture risk, probably in part due to beneficial gains in aBMD and muscle strength.

Dual-Energy Imaging of Bone Marrow Edema on a Dedicated Multi-Source Cone-Beam CT System for the Extremities

PURPOSE

Arthritis and bone trauma are often accompanied by bone marrow edema (BME). BME is challenging to detect in CT due to the overlaying trabecular structure but can be visualized using dual-energy (DE) techniques to discriminate water and fat. We investigate the feasibility of DE imaging of BME on a dedicated flat-panel detector (FPD) extremities cone-beam CT (CBCT) with a unique x-ray tube with three longitudinally mounted sources.

METHODS

Simulations involved a digital BME knee phantom imaged with a 60 kVp low-energy beam (LE) and 105 kVp high-energy beam (HE) (+0.25 mm Ag filter). Experiments were also performed on a test-bench with a Varian 4030CB FPD using the same beam energies as the simulation study. A three-source configuration was implemented with x-ray sources distributed along the longitudinal axis and DE CBCT acquisition in which the superior and inferior sources operate at HE (and collect half of the projection angles each) and the central source operates at LE. Three-source DE CBCT was compared to a double-scan, single-source orbit. Experiments were performed with a wrist phantom containing a 50 mg/ml densitometry insert submerged in alcohol (simulating fat) with drilled trabeculae down to ~1 mm to emulate the trabecular matrix. Reconstruction-based three-material decomposition of fat, soft tissue, and bone was performed.

RESULTS

For a low-dose scan (36 mAs in the HE and LE data), DE CBCT achieved combined accuracy of ~0.80 for a pattern of BME spherical lesions ranging 2.5 - 10 mm diameter in the knee phantom. The accuracy increased to ~0.90 for a 360 mAs scan. Excellent DE discrimination of the base materials was achieved in the experiments. Approximately 80% of the alcohol (fat) voxels in the trabecular phantom was properly identified both for single and 3-source acquisitions, indicating the ability to detect edemous tissue (water-equivalent plastic in the body of the densitometry insert) from the fat inside the trabecular matrix (emulating normal trabecular bone with significant fraction of yellow marrow).

CONCLUSION

Detection of BME and quantification of water and fat content were achieved in extremities DE CBCT with a longitudinal configuration of sources providing DE imaging in a single gantry rotation. The findings support the development of DE imaging capability for CBCT of the extremities in areas conventionally in the domain of MRI.