Age-related differences in distractor interference on line bisection

Using a bisection paradigm, we investigated age-related differences in susceptibility to distractor interference. Older and younger participants were asked to bisect a horizontal line flanked by a pair of distractors, placed in either left or right hemispace. The results showed that (1) in both groups the distractors interfered with line bisection so that the localization of subjective midpoint was selectively shifted away from their position; (2) the shifting of subjective midpoint was greater in the older than in the younger group when the distractors were placed in the left hemispace. We suggest that the increase of the bisection bias in the older group depends on changes in attentional mechanisms involved in inhibiting irrelevant information.     

Atomic force microscopy for biomechanical and structural analysis of human dermis: A complementary tool for medical diagnosis and therapy monitoring

Skin mechanical properties are usually measured considering the entire skin thickness and very little is known about the mechanical behaviour of individual skin layers. We propose atomic force microscopy (AFM) as a tool to quantify nanoscale changes in the biomechanical properties and ultrastructure of human papillary dermis exposed to different mechanical and physical stimuli. Samples from 3 human skin biopsies were studied: one stretched by obesity, one subjected to a high level of sun exposure and normal skin as control. Slices of the papillary dermis layer were harvested at controlled depths from each skin biopsy and 25 μm² areas of each slice were imaged and D‐periodicity of collagen fibres measured by AFM, together with their stiffness. Standard histological analysis was also carried out to correlate biochemical properties and their distribution with stiffness and topography. We obtained similar stiffness values between the sample affected by obesity and the control sample at any depth level into the dermis, while the sun‐exposed sample presented a significantly lower stiffness. Additionally, all samples presented an increase in the stiffness at higher depths into the papillary dermis layer. Collagen fibres close to the epidermis of sample affected either by obesity and sun exposure—the former even more than the latter—are thicker and present a larger D‐period than those in the control sample. Our results open the possibility to use structural and mechanical analysis based on AFM as a complementary tool for medical diagnosis and therapy monitoring.     

DNA methylation patterns of genes related to immune response in the different clinical forms of oral lichen planus

Background

The oral lichen planus is a chronic inflammatory disease. Although its aetiology is not well understood, the role of T lymphocytes in its inflammatory events is recognised. Identifying the epigenetic mechanisms involved in the pathogenesis of this immune‐mediated condition is fundamental for understanding the inflammatory reaction that occurs in the disease. The purpose of this work was to evaluate the methylation pattern of 21 immune response‐related genes in the different clinical forms of oral lichen planus.

Methods

A cross‐sectional study was performed to analyse the DNA methylation patterns in three distinct groups of oral lichen planus: (i) reticular/plaque lesions; (ii) erosive lesions; (iii) normal oral mucosa (control group). After DNA extraction from biopsies, the samples were submitted to digestions by methylation‐sensitive and methylation‐dependent enzymes and double digestion. The relative percentage of methylated DNA for each gene was provided using real‐time polymerase chain reaction arrays.

Results

Hypermethylation of the STAT5A gene was observed only in the control group (59.0%). A higher hypermethylation of the ELANE gene was found in reticular/plaque lesions (72.1%) compared to the erosive lesions (50.0%).

Conclusion

Our results show variations in the methylation profile of immune response‐related genes, according to the clinical type of oral lichen planus after comparing with the normal oral mucosa. Further studies are necessary to validate these findings using gene expression analysis.     

Anatomic structures at risk in anteroposterior screw fixation of posterior malleolar fractures: A cadaver study

IntroductionPercutaneous anterior-posterior (AP) screw is an option for posterior malleolus fracture fixation when the fracture fragment can be reduced indirectly by the mean of ligamentotaxis. However, anterior anatomic structures could be injured during screw placement.Materials and methodsEleven below-knee cadavers were employed for the placement of AP screws in an attempt of fixing assumed Haraguchi Type-I posterior malleolar fractures. Three entry points were selected as medial to the anterior tibial tendon (ATT), lateral to the ATT, and lateral to the extensor digitorum longus (EDL). Three AP screws were placed under guidance of fluoroscopy. After dissection, measurements were made (mm) from each screw to nearby structures. Distances were calculated and damage to structures was documented.ResultsMean, minimum, and maximum distances from the medial screw to the greater saphenous vein, TA, EHL, anterior tibial artery (ATA), and deep peroneal nerve (DPN), were 18.1 (12–25) mm, 2.0 (0–5) mm, 13.6 (9–20) mm, 16.6 (9–25) mm, and 20.1 (12–27) mm. From the middle screw to the ATA, DPN, TA, EHL, and EDL, were 1.2 (0–3) mm, 4.9 (3–9) mm, 3.8 (1–7) mm, 0.4 (0–2) mm, and 13.6 (10–18) mm. From the lateral screw to the superficial peroneal nerve (SPN), EDL, DPN, and ATA, were 10.8 (0–16) mm, 1.2 (0–4) mm, 15.9 (11–25) mm, 19 (15–27) mm. The SPN was found partially cut by the lateral screw on 1 specimen.ConclusionsLateral and middle percutaneous AP screw placement put certain anatomic structures at-risk of injury. Medial screw placement did not result in appreciable damage to adjacent structures. Entry point of AP screws should be selected with respect to posterior malleolar fracture and anatomic structures.Level of evidenceIV.     

Vertebral Fracture Assessment in Acromegaly

Most vertebral fractures (VFs) are asymptomatic and incidentally found on X-rays. The effects of acromegaly on bone mineral density (BMD) are still controversial, and the prevalence of VFs in this specific population remains uncertain. The objective of this study was to assess VFs in acromegaly through vertebral fracture assessment (VFA) by dual-energy X-ray absorptiometry (DXA). Seventy-five acromegalic patients from the same center (53 female; age: 48.9 ± 14.5 yr) were enrolled in this study. None of them referred previous fragility fracture. They were divided according to the presence or absence of moderate or severe VFs on VFA, a densitometric spine imaging. Age, gender, estimated duration of disease, insulin-like growth factor I levels, disease control and gonadal status, as well as BMD and body composition (analyzed by DXA) were compared between these 2 groups. A prevalence of 10.6% of clinically unapparent VFs was observed. Eight patients had 13 moderate or severe VFs, and only one of them had osteoporosis at densitometry. There was a trend to longer duration of acromegaly before diagnosis, higher prevalence of hypogonadism, and higher BMD Z-score at lumbar spine and femoral neck in fractured patients, without reaching statistical significance. There is a significant prevalence of moderate and severe VFs in acromegalic patients, independently of BMD. More longitudinal and controlled studies are needed to recommend the use of VFA in all acromegalic patients submitted to DXA scan. VFA is simple, practical, uses low radiation, and may provide important information in the management of acromegaly.     

Intraventricular entrapment of a Sapien-3 balloon in transapical TAVR: A near missed catastrophe

Balloon rupture is an uncommon complication during balloon-expandable transcatheter aortic valve replacement (TAVR). We describe a balloon rupture and tearing with intraventricular entrapment complicating transapical-TAVR, as well as our bailout retrieval of the failed device.