Do normal radiographs exclude asphericity of the femoral head-neck junction?

Asphericity of the femoral head-neck junction is one cause for femoroacetabular impingement of the hip. However, the asphericity often is underestimated on conventional radiographs. This study compares the presence of asphericity on conventional radiographs with its appearance on radial slices of magnetic resonance arthrography (MRA). We retrospectively reviewed 58 selected hips in 148 patients who underwent a surgical dislocation of the hip. To assess the circumference of the proximal femur, alpha angle and height of asphericity were measured in 14 positions using radial slices of MRA. The hips were assigned to one of four groups depending on the appearance of the head-neck junction on anteroposterior pelvic and lateral crosstable radiographs. Group I (n = 19) was circular on both planes, Group II (n = 19) was aspheric on the crosstable view, Group III (n = 4) was aspheric on the anteroposterior view, and Group IV (n = 13) was aspheric on both views. In all four groups, the highest alpha angle was found in the anterosuperior area of the head-neck junction. Even when conventional radiographs appeared normal, an increased alpha angle was present anterosuperiorly. Without the use of radial slices in MRA, the asphericity would be underestimated in these patients.

Diesel exhaust particles modulate the tight junction protein occludin in lung cells in vitro

ABSTRACT: BACKGROUND: Using an in vitro triple cell co-culture model consisting of human epithelial cells (16HBE14o-), monocyte-derived macrophages and dendritic cells, it was recently demonstrated that macrophages and dendritic cells create a transepithelial network between the epithelial cells to capture antigens without disrupting the epithelial tightness. The expression of the different tight junction proteins in macrophages and dendritic cells, and the formation of tight junction-like structures with epithelial cells has been demonstrated. Immunofluorescent methods combined with laser scanning microscopy and quantitative real-time polymerase chain reaction were used to investigate if exposure to diesel exhaust particles (DEP) (0.5, 5, 50, 125 mug/ml), for 24 h, can modulate the expression of the tight junction mRNA/protein of occludin, in all three cell types. RESULTS: Only the highest dose of DEP (125 mug/ml) seemed to reduce the occludin mRNA in the cells of the defence system however not in epithelial cells, although the occludin arrangement in the latter cell type was disrupted. The transepithelial electrical resistance was reduced in epithelial cell mono-cultures but not in the triple cell co-cultures, following exposure to high DEP concentration. Cytotoxicity was not found, in either epithelial mono-cultures nor in triple cell co-cultures, after exposure to the different DEP concentrations. CONCLUSION: We concluded that high concentrations of DEP (125 mug/ml) can modulate the tight junction occludin mRNA in the cells of the defence system and that those cells play an important role maintaining the epithelial integrity following exposure to particulate antigens in lung cells.

Potential role of pre-existing blood vessels for vascularization and mineralization of osteochondral grafts: an intravital microscopic study in mice

BACKGROUND: The aim of this study was to develop an experimental model that allows to elude the potential role of the preexisting graft microvasculature for vascularization and mineralization of osteochondral grafts. ANIMALS AND METHODS: For that purpose, the II-IV metatarsals of fetal DDY-mice known to be nonvascularized at day 16 of gestation (M16) but vascularized at day 18 (M18) were freshly transplanted into dorsal skin fold chambers of adult DDY mice. Using intravital microscopy angiogenesis, leukocyte-endothelium interaction and mineralization were assessed for 12 days. RESULTS: Angiogenesis occurred at 32 hours in M18, but not before 57 hours in M16 (p = 0.002), with perfusion of these vessels at 42 hours (p = 0.005) and 65 hours (p = 0.1), respectively. Vessels reached a density three times as high as that of the recipient site at day 6, remaining constant until day 12 in M18, whereas in M16 vascular density increased from day 6 and reached that of M18 at day 12 (p = 0.04). Leukocyte-endothelium interaction showed sticker counts elevated by a factor of 4-5 in M18 as compared to M16. Mineralization of osteochondral grafts did not differ between M16 and M18, which significantly increased in both groups throughout the observation period. INTERPRETATION: We propose the faster kinetics in the angiogenic response to M18 and the elevated counts of sticking leukocytes to rest on the potential of establishing end-to-end anastomoses (inosculation) of the vascularized graft with recipient vessels.

A modular LHC built on the DNA three-way junction

A light-harvesting complex composed of a p-stacked multichromophoric array in a DNA three-way junction is described. The modular design allows for a ready exchange of non-covalently attached energy acceptors

Single-Molecule Conductance of Functionalized Oligoynes: Length Dependence and Junction Evolution

We report a combined experimental and theoretical investigation of the length dependence and anchor group dependence of the electrical conductance of a series of oligoyne molecular wires in single-molecule junctions with gold contacts. Experimentally, we focus on the synthesis and properties of diaryloligoynes with n = 1, 2, and 4 triple bonds and the anchor dihydrobenzo[b]thiophene (BT). For comparison, we also explored the aurophilic anchor group cyano (CN), amino (NH2), thiol (SH), and 4-pyridyl (PY). Scanning tunneling microscopy break junction (STM-BJ) and mechanically controllable break junction (MCBJ) techniques are employed to investigate single-molecule conductance characteristics. The BT moiety is superior as compared to traditional anchoring groups investigated so far. BT-terminated oligoynes display a 100% probability of junction formation and possess conductance values which are the highest of the oligoynes studied and, moreover, are higher than other conjugated molecular wires of similar length. Density functional theory (DFT)-based calculations are reported for oligoynes with n = 1−4 triple bonds. Complete conductance traces and conductance distributions are computed for each family of molecules. The sliding of the anchor groups leads to oscillations in both the electrical conductance and the binding energies of the studied molecular wires. In agreement with experimental results, BT-terminated oligoynes are predicted to have a high electrical conductance. The experimental attenuation constants βH range between 1.7 nm−1 (CN) and 3.2 nm−1 (SH) and show the following trend: βH(CN) < βH(NH2) < βH(BT) < βH(PY) ≈ βH(SH). DFT-based calculations yield lower values, which range between 0.4 nm−1 (CN) and 2.2 nm−1 (PY).

Single Molecular Conductance of Tolanes: Experimental and Theoretical Study on the Junction Evolution Dependent on the Anchoring Group

Employing a scanning tunneling microscopy based beak junction technique and mechanically controlled break junction experiments, we investigated tolane (diphenylacetylene)-type single molecular junctions having four different anchoring groups (SH, pyridyl (PY), NH2, and CN) at a solid/liquid interface. The combination of current–distance and current–voltage measurements and their quantitative statistical analysis revealed the following sequence for junction formation probability and stability: PY > SH > NH2 > CN. For all single molecular junctions investigated, we observed the evolution through multiple junction configurations, with a particularly well-defined binding geometry for PY. The comparison of density functional theory type model calculations and molecular dynamics simulations with the experimental results revealed structure and mechanistic details of the evolution of the different types of (single) molecular junctions upon stretching quantitatively.

Effect of lateral meniscectomy and osteochondral grafting of a lateral femoral condylar defect on contact mechanics: a cadaveric study in dogs

BACKGROUND Osteochondral autograft transfer (OAT) aims at restoring normal articular cartilage surface geometry and articular contact mechanics. To date, no studies have evaluated the contact mechanics of the canine stifle following OAT. Additionally, there are no studies that evaluated the role of the meniscus in contact mechanics following OAT in human or canine femorotibial joints. The objective of this study was to measure the changes in femorotibial contact areas (CA), mean contact pressure (MCP) and peak contact pressure (PCP) before and after osteochondral autograft transplantation (OAT) of a simulated lateral femoral condylar cartilage defect with an intact lateral meniscus and following lateral meniscectomy. RESULTS With an intact lateral meniscus, creation of an osteochondral defect caused a decrease in MCP and PCP by 11% and 30%, respectively, compared to the intact stifle (p < 0.01). With an intact meniscus, implanting an osteochondral graft restored MCP and PCP to 96% (p = 0.56) and 92% (p = 0.41) of the control values. Lateral meniscectomy with grafting decreased CA by 54% and increased PCP by 79% compared to the intact stifle (p < 0.01). CONCLUSIONS OAT restored contact pressures in stifles with a simulated lateral condylar defect when the meniscus was intact. The lateral meniscus has a significant role in maintaining normal contact pressures in both stifles with a defect or following OAT. Meniscectomy should be avoided when a femoral condylar defect is present and when performing OAT.

Combinatorial chromophore assembly inside a DNA four-way junction

In 1964 first proposed by Robin Holliday as a mechanistic model to solve the mystery of how genetic information is exchanged in yeast, the DNA four-way junction or Holliday junction (HJ) was proofed to be the key in- termediate in homologous recombination and became an important tool in the field of DNA origami, computation and nanomachines. Herein we use the assembly of four modified nucleic acid strands into the planar square conformation of this higher order DNA structure to demonstrate in a proof of principle manner the cumulative effect of pyrene moieties interacting inside the junction.[1][2]

Table-mounted ring retractor for consistent visualization in endoscopy-assisted anterior reconstruction of burst fractures of the thoracolumbar junction

The authors tested an autoclavable external ring retractor, fixed to the operation table, for the endoscopic reconstruction of anterior column injuries of the thoracolumbar junction. It served as a retractor for the diaphragm, and offered a stable support for the scope and other instruments, making an assistant superfluous. Moreover, it allowed bimanual manipulation. Of course, the two-dimensional image, provided by the scope, necessitated proper eye-hand coordination. Twenty-eight consecutive patients underwent either a monosegmental (n = 10) or a bisegmental (n = 18) anterior stabilization in the area Th11L1. Three portals were necessary, but an assistant was not needed. The overall (mean +/- SD) operating time was 196 +/- 56 min, the blood loss was 804 +/- 719 mL. Intraoperatively, one epidural bleeding and a single screw cut-out occurred. All complications were managed endoscopically. Postoperatively, evacuation of a haemothorax (n = 1) was necessary. In all patients, wounds and fractures healed uneventfully. The combination of the endoscopic technique and the retractor system was feasible, successful, safe, and time efficient. Moreover, it allowed for anterior instrumentation of thoracolumbar fractures by a single surgeon. It became the standard approach in the authors' department.

The craniosacral progression of muscle development influences the emergence of neuromuscular junction alterations in a severe murine model for spinal muscular atrophy.

AIMS As 4-day-old mice of the severe spinal muscular atrophy (SMA) model (dying at 5-8 days) display pronounced neuromuscular changes in the diaphragm but not the soleus muscle, we wanted to gain more insight into the relationship between muscle development and the emergence of pathological changes and additionally to analyse intercostal muscles which are affected in human SMA. METHODS Structures of muscle fibres and neuromuscular junctions (NMJs) of the diaphragm, intercostal and calf muscles of prenatal (E21) and postnatal (P0 and P4) healthy and SMA mice were analysed by light and transmission electron microscopy. NMJ innervation was studied by whole mount immunofluorescence in diaphragms of P4 mice. RESULTS During this period, the investigated muscles still show a significant neck-to-tail developmental gradient. The diaphragm and calf muscles are most and least advanced, respectively, with respect to muscle fibre fusion and differentiation. The number and depth of subsynaptic folds increases, and perisynaptic Schwann cells (PSCs) acquire a basal lamina on their outer surface. Subsynaptic folds are connected to an extensive network of tubules and beaded caveolae, reminiscent of the T system in adult muscle. Interestingly, intercostal muscles from P4 SMA mice show weaker pathological involvement (that is, vacuolization of PSCs and perineurial cells) than those previously described by us for the diaphragm, whereas calf muscles show no pathological changes. CONCLUSION SMA-related alterations appear to occur only when the muscles have reached a certain developmental maturity. Moreover, glial cells, in particular PSCs, play an important role in SMA pathogenesis.

Diminishing parochialism in intergroup conflict by disrupting the right temporo-parietal junction.

Individuals react to violation of social norms by outgroup members differently than to transgressions of those same norms by ingroup members: namely outgroup perpetrators are punished much more harshly than ingroup perpetrators. This parochial punishment pattern has been observed and extensively studied in social psychology and behavioral economics. Despite progress in recent years, however, little is known about the neural underpinnings of this intergroup bias. Here, we demonstrate by means of transcranial magnetic stimulation (TMS) that the transient disruption of the right, but not the left temporo-parietal junction (TPJ), reduces parochial punishment in a third-party punishment paradigm with real social groups. Moreover, we show that this observed TMS effect on parochial punishment is mediated by a classical punishment motive, i.e. retaliation. Finally, our data suggests that a change in perspective-taking might be the underlying mechanism that explains the impact of right TPJ disruption on retaliation motivation and parochial punishment. These findings provide the first causal evidence that the right TPJ plays a pivotal role in the implementation of parochial behaviors.

A modular LHC built on the DNA three-way junction

Over the past years, in numerous studies the DNA double helix serves as a scaffold for the controlled arrangement of functional molecules, including a wide range of different chromophores. Other nucleic acid structures like the DNA three-way junction have been exploited for this purpose as well. Recently, the successful development of DNA-based light-harvesting antenna systems have been reported. Herein, we describe the use of the DNA three-way junction (3WJ) as a versatile scaffold for the modular construction of an artificial light harvesting complex (LHC). The LHC is based on a modular construction in which a phenanthrene antenna is located in one of the three stems and the acceptor is brought into proximity of the antenna through the annealing of the third strand. Phenanthrene excitation (320 nm) is followed by energy transfer to pyrene (resulting in exciplex emission), perylenediimide (quencher) or a cyanine dye (cyanine fluorescence).

Adenocarcinoma at the gastroesophageal junction.

The following, from the 12th OESO World Conference: Cancers of the Esophagus, includes commentaries on the clinical differences between carcinomas arising slightly above, slightly below, and within the gastroesophageal junction (GEJ); information provided by biopsies; information provided by resection specimens following neoadjuvant therapy; histologic differences existing between carcinomas arising slightly above, slightly below, and within the GEJ; differences provided by immunohistochemistry in these tumors; information given by endoscopic mucosal resection specimens; the role of esophageal pyloric gland adenomas as precursors of adenocarcinomas in the region of the cardia; the role of pancreatic metaplasia; Her2 immunoreactivity to make distinctions in the site of origin; and intestinal metaplasia limited to the cardia as a precursor of adenocarcinoma.