Biomechanical comparison of nitinol compression staples versus fully threaded lag screws for talonavicular arthrodesis.

Background: Talonavicular arthrodesis (TNA) is indicated for treatment of disorders that require immobilization of the hindfoot. Lag screw fixation is considered the reference standard technique for TNA. Despite consistently favorable clinical results using lag screw fixation, it is still associated with higher than desired complication and failure rates. Nitinol compression staples have been used for TNA based on potential advantages over lag screw fixation. However, functional biomechanical data comparing lag screw and nitinol compression staples for TNA are lacking. Therefore, the objective of this study was to compare nitinol compression staples to fully threaded lag screws for use in TNA with respect to their biomechanical properties during functional robotic testing. Methods: TNA was performed on cadaveric feet (n = 12; 6 matched pairs) using either two nitinol compression staples (Arthrex, Naples, FL) or two fully threaded lag screws (Arthrex, Naples, FL) in random order, alternating between paired left and right feet. After instrumentation, specimens were mounting in a robotic testing system and loaded at 89 N/sec from 30 N to 445 N for 1 min. Then, continuous compressive load of 445 N was applied while cycling from 30° plantarflexion to 15° dorsiflexion for 10 cycles. Optical tracking markers attached to the talus and navicular bone tracked displacements. Translation data were recorded along the X, Y, Z planes. Rotation data were recorded for roll, pitch, and yaw. Significant (p < 0.05) differences between fixation methods were determined using paired t-Tests for each measured variable. Results: There were no statistically significant differences between staples and screws for translation in X, Y, or Z planes. When comparing rotation (roll, pitch, and yaw), there were no statistically significant differences with the exception of increased roll rotation for staple fixation versus lag screw fixation during static compression testing (p = 0.009). Conclusion: Based on comparison to the reference standard lag screw fixation for clinically relevant biomechanical properties measured during functional robotic testing of the hindfoot, nitinol compression staples are a viable option for talonavicular arthrodesis.

Towards Neutron Capture on Exotic Nuclei: Demonstrating (d,pγ) as a Surrogate Reaction for (n,γ).

The neutron-capture reaction plays a critical role in the synthesis of the elements in stars and is important for societal applications including nuclear power generation and stockpile-stewardship science. However, it is difficult-if not impossible-to directly measure neutron capture cross sections for the exotic, short-lived nuclei that participate in these processes. In this Letter we demonstrate a new technique which can be used to indirectly determine neutron-capture cross sections for exotic systems. This technique makes use of the (d,p) transfer reaction, which has long been used as a tool to study the structure of nuclei. Recent advances in reaction theory, together with data collected using this reaction, enable the determination of neutron-capture cross sections for short-lived nuclei. A benchmark study of the ^{95}Mo(d,p) reaction is presented, which illustrates the approach and provides guidance for future applications of the method with short-lived isotopes produced at rare isotope accelerators.

Short communication: Behavioral evaluation of the analgesic effect of flunixin meglumine in lame dairy cows.

The objective of this study was to evaluate the effect of flunixin meglumine treatment on lameness pain in dairy cows. Twenty-four lactating Holstein cows were enrolled in the study based on visual observation of abnormal locomotion. The primary measurement endpoint was weight-shifting between the rear limbs. Weight-shifting was calculated as the standard deviation of the weight borne on the rear limbs over a 15 min period; this value correlates directly with lameness pain in dairy cows. After collecting baseline weight-bearing data, we randomly assigned cows to 1 of 2 treatment groups: 2.2 mg/kg body weight flunixin meglumine (2 mL/45 kg) or an equivalent volume of isotonic sterile saline solution. Weight-bearing data were collected from each cow at 2, 6, 12, and 24 h after a single intravenous drug treatment. Mean locomotion scores over the 2 d before treatment were 2.38/5 in the flunixin-treated group and 2.43/5 in the saline-treated control group; these values were not significantly different. Weight-shifting values were also not significantly different on either pretreatment day. Cows treated with flunixin meglumine showed significantly less weight-shifting between the rear limbs at 6, 12, and 24 h after treatment compared with saline-treated controls, providing evidence that flunixin meglumine alleviates lameness-associated pain.

Evidence for Gamow-Teller Decay of

The ß-delayed neutron emission of ^{83,84}Ga isotopes was studied using the neutron time-of-flight technique. The measured neutron energy spectra showed emission from states at excitation energies high above the neutron separation energy and previously not observed in the ß decay of midmass nuclei. The large decay strength deduced from the observed intense neutron emission is a signature of Gamow-Teller transformation. This observation was interpreted as evidence for allowed ß decay to ^{78}Ni core-excited states in ^{83,84}Ge favored by shell effects. We developed shell model calculations in the proton fpg_{9/2} and neutron extended fpg_{9/2}+d_{5/2} valence space using realistic interactions that were used to understand measured ß-decay lifetimes. We conclude that enhanced, concentrated ß-decay strength for neutron-unbound states may be common for very neutron-rich nuclei. This leads to intense ß-delayed high-energy neutron and strong multineutron emission probabilities that in turn affect astrophysical nucleosynthesis models.

Critical Airway Compromise due to a Massive Vagal Schwannoma.

We describe the case of a 37-year-old man with a slowly enlarging neck lump and compressive symptoms. He presented to a separate institution 10 years prior where an observational approach was advocated. Following preoperative investigations and embolization, an 11cm vagal schwannoma was excised and vagus nerve was sacrificed. Although conservative management is appropriate for a select patient population, surgical excision is treatment of choice for cervical neurogenic tumours and paraganglionomas and must be considered in young patients or rapidly expanding tumours to avoid compressive symptoms, as in this case.

Oncogenic PI3K and K-Ras stimulate de novo lipid synthesis through mTORC1 and SREBP.

An enhanced capacity for de novo lipid synthesis is a metabolic feature of most cancer cells that distinguishes them from their cells of origin. However, the mechanisms through which oncogenes alter lipid metabolism are poorly understood. We find that expression of oncogenic PI3K (H1047R) or K-Ras (G12V) in breast epithelial cells is sufficient to induce de novo lipogenesis, and this occurs through the convergent activation of the mechanistic target of rapamycin complex 1 (mTORC1) downstream of these common oncogenes. Oncogenic stimulation of mTORC1 signaling in this isogenic setting or a panel of eight breast cancer cell lines leads to activation of the sterol regulatory element-binding proteins (SREBP1 and SREBP2) that are required for oncogene-induced lipid synthesis. The SREBPs are also required for the growth factor-independent growth and proliferation of oncogene-expressing cells. Finally, we find that elevated mTORC1 signaling is associated with increased mRNA and protein levels of canonical SREBP targets in primary human breast cancer samples. These data suggest that the mTORC1/SREBP pathway is a major mechanism through which common oncogenic signaling events induce de novo lipid synthesis to promote aberrant growth and proliferation of cancer cells.

A MultiCenter Pilot Randomized Controlled Trial of Remote Ischemic Preconditioning in Major Vascular Surgery.

A pilot randomized controlled trial that evaluated the effect of remote ischemic preconditioning (RIPC) on clinical outcomes following major vascular surgery was performed. Eligible patients were those scheduled to undergo open abdominal aortic aneurysm repair, endovascular aortic aneurysm repair, carotid endarterectomy, and lower limb revascularization procedures. Patients were randomized to RIPC or to control groups. The primary outcome was a composite clinical end point comprising any of cardiovascular death, myocardial infarction, new-onset arrhythmia, cardiac arrest, congestive cardiac failure, cerebrovascular accident, renal failure requiring renal replacement therapy, mesenteric ischemia, and urgent cardiac revascularization. Secondary outcomes were components of the primary outcome and myocardial injury as assessed by serum troponin values. The primary outcome occurred in 19 (19.2%) of 99 controls and 14 (14.1%) of 99 RIPC group patients (P = .446). There were no significant differences in secondary outcomes. Our trial generated data that will guide future trials. Further trials are urgently needed.

Three-dimensional computed tomographic reconstruction of the carotid artery: identifying high bifurcation.

OBJECTIVE: To investigate variability in the level of bifurcation relative to other anatomical landmarks on computed tomography (CT) and to develop an objective and reproducible technique for identifying patients with a high carotid bifurcation who might therefore be at greater risk of operative complications. METHODS: This was a retrospective cross-sectional, imaging study. A series of 86 nonselected consecutive CT carotid angiograms (172 arteries) were analysed. Using three-dimensional reconstructive software, the curved length (CL) of the internal carotid artery (ICA) and the straight-line distance (SLD) from the bifurcation to the base of skull was measured for 140 carotid arteries. The tortuosity index (TI) of each ICA was calculated by dividing CL by SLD. The relationship of the bifurcation to eight anatomical landmarks in the neck was assessed in order to identify a landmark that could act as a surrogate marker of high carotid bifurcation. The landmarks examined were the angle of mandible, greater horn of hyoid, body of hyoid, upper margin of thyroid cartilage, cervical vertebrae, mastoid process, sternoclavicular joint, and sternal notch. RESULTS: The median curved length of the ICA was 80.4 mm (range 58.0-129.0 mm). The median distance of bifurcation from the base of the skull was 72.7 mm (range 58.1-98.1 mm). There was excellent interobserver agreement in measuring SLD, with an intraclass correlation coefficient of 0.993 (p = .00). The median tortuosity index was 1.12 (range 1.01-1.64). Distance from the mastoid process had the greatest correlation with high bifurcation; Pearson's correlation coefficient of 0.894 (two-tailed p = .00). Bifurcations within 5 cm of the mastoid process are likely to be in the highest quartile (82.9% sensitive, 80.1% specific). CONCLUSIONS: Measuring the distance of carotid bifurcation from the base of the skull (SLD), a measure previously not well defined, may be useful in predicting difficult neck dissection and endarterectomy. A distance from mastoid of ≤ 5 cm may also alert the surgeon to potential difficulties.

Double-magic nature of 132Sn and 208Pb through lifetime and cross-section measurements.

Single-neutron states in (133)Sn and (209)Pb, which are analogous to single-electron states outside of closed atomic shells in alkali metals, were populated by the ((9)Be, (8)Be) one-neutron transfer reaction in inverse kinematics using particle-γ coincidence spectroscopy. In addition, the s(1/2) single-neutron hole-state candidate in (131)Sn was populated by ((9)Be, (10)Be). Doubly closed-shell (132)Sn (radioactive) and (208)Pb (stable) beams were used at sub-Coulomb barrier energies of 3 MeV per nucleon. Level energies, γ-ray transitions, absolute cross sections, spectroscopic factors, asymptotic normalization coefficients, and excited-state lifetimes are reported and compared with shell-model expectations. The results include a new transition and precise level energy for the 3p(1/2) candidate in (133)Sn, new absolute cross sections for the 1h(9/2) candidate in (133)Sn and 3s(1/2) candidate in (131)Sn, and new lifetimes for excited states in (133)Sn and (209)Pb. This is the first report on excited-state lifetimes of (133)Sn, which allow for a unique test of the nuclear shell model and (132)Sn double-shell closure.

Low-dose radiation exposure induces a HIF-1-mediated adaptive and protective metabolic response.

Because of insufficient understanding of the molecular effects of low levels of radiation exposure, there is a great uncertainty regarding its health risks. We report here that treatment of normal human cells with low-dose radiation induces a metabolic shift from oxidative phosphorylation to aerobic glycolysis resulting in increased radiation resistance. This metabolic change is highlighted by upregulation of genes encoding glucose transporters and enzymes of glycolysis and the oxidative pentose phosphate pathway, concomitant with downregulation of mitochondrial genes, with corresponding changes in metabolic flux through these pathways. Mechanistically, the metabolic reprogramming depends on HIF1α, which is induced specifically by low-dose irradiation linking the metabolic pathway with cellular radiation dose response. Increased glucose flux and radiation resistance from low-dose irradiation are also observed systemically in mice. This highly sensitive metabolic response to low-dose radiation has important implications in understanding and assessing the health risks of radiation exposure.

Correlations in intermediate energy two-proton removal reactions.

We report final-state-exclusive measurements of the light charged fragments in coincidence with (26)Ne residual nuclei following the direct two-proton removal from a neutron-rich (28)Mg secondary beam. A Dalitz-plot analysis and comparisons with simulations show that a majority of the triple-coincidence events with two protons display phase-space correlations consistent with the (two-body) kinematics of a spatially correlated pair-removal mechanism. The fraction of such correlated events, 56(12)%, is consistent with the fraction of the calculated cross section, 64%, arising from spin S=0 two-proton configurations in the entrance-channel (shell-model) (28)Mg ground state wave function. This result promises access to an additional and more specific probe of the spin and spatial correlations of valence nucleon pairs in exotic nuclei produced as fast secondary beams.

Sizing fenestrated aortic stent-grafts.

INTRODUCTION: Fenestrated aortic stent-grafts are increasingly being used to treat patients with juxtarenal abdominal aortic aneurysms (AAA). Sizing of these stent-grafts is critical to ensure success and requires detailed expert assessment of aortic morphology. At present little is known about how sizing of these stent-grafts varies between observers and the necessary tolerances involved to ensure a successful procedure. METHODS: CT scans of 19 consecutive patients with juxtarenal aortic aneurysms that underwent successful endovascular repair with fenestrated stent-grafts were selected. Sizing of fenestrated aortic stent-grafts was performed independently by four experienced endovascular surgeons and results were compared. Data from the stent-graft manufacturer was available for comparison in 12 cases. RESULTS: All observers agreed on the number of fenestrations; 16 devices had 3 fenestrations and 3 had 4. The overall inter-observer measurement error for all target vessel orientation was ± 12.6° (10.8-14.4 95% CI), and for distance between target vessels ± 5.3 mm (4.4-6.2 95% CI). The median difference in internal stent-graft diameter was 1 stent size. Agreement on fenestration type ranged from (84-95%). Comparison was performed with the manufactured stent-graft in 12 cases. The overall mean difference of target vessel orientation between the manufactured devices and the four observers was -1.3° (SD ± 6.9,-3.8-1.2 95% CI). There was less agreement between observers and device manufacturers on body and limb lengths and distal limb diameters. CONCLUSIONS: There was generally a high level of agreement between experienced endovascular surgeons in sizing the fenestrated stent component. There were differences in component lengths but these could have been accommodated by varying the degree of overlap between components.

Setting core standards: privacy, identity & interoperability.

This position paper focuses on strategic developments and underlying concepts emerging out of the standards and associated domains. It addresses the issue of personal privacy in the wider context of interoperability across an ever-growing range of e-health and social care support systems and processes. These will increasingly be driven by major growth in the elderly segment of national populations where unambiguous identification of both patients and care staff both in hospitals and the community will become significant issues. This is particularly so where remote patient monitoring and access control to personal data is concerned, and is further complicated where racial, cultural and linguistic barriers are prevalent.

Outcomes in achalasia from a surgical unit where pneumatic dilatation is first-line therapy.

The management of achalasia remains controversial, with little consensus on the optimal patient treatment pathway. In our own esophageal unit, we offer pneumatic dilatation as the initial therapy in most patients as first-line therapy. In this study, we aimed to examine the safety and efficacy of our own approach to the management of patients with a diagnosis of achalasia, examining symptomatic outcomes, patient satisfaction, and need for further intervention, as well as examining patient factors associated with treatment failure. Sixty-seven consecutive patients underwent pneumatic dilatation as first-line therapy (53% male, mean age 46 years). All attended regular outpatient follow-up (mean 37, range 3-132 months). Twenty-five percent of patients required a second intervention because of symptom recurrence, at a median period of 4.5 months. Symptomatic outcomes were excellent or good in 80%. Significant predictors of treatment failure and poor symptom score included a younger age at the time of diagnosis and increased esophageal diameter on barium swallow. This study suggests that pneumatic dilatation is a safe and effective approach as first-line therapy in patients with newly diagnosed achalasia.

Techniques for supra-aortic trunk preservation in thoracic endovascular aneurysm repair.

Stent graft placement for aneurysmal disease of the aortic arch and proximal descending aorta is limited by the need to preserve flow to the supra-aortic trunks. Whilst extra-anatomical bypass and procedures combining open and endovascular arch repair are currently used in this setting, less invasive totally endovascular solutions have been described. These include in-situ fenestration of a thoracic stent graft using a retrograde approach from the target vessel to the lumen of the main device, to which it is connected by a smaller covered stent. Alternatively, so-called 'chimney' stents have been used, placing a parallel stent alongside the main device, connecting the aortic branch vessel with the native aortic lumen proximal to the seal zone of the main thoracic device. We review these techniques and discuss the merits and potential disadvantages of each procedure.

Ready-to-fenestrate stent grafts in the treatment of juxtarenal aortic aneurysms: proposal for an off-the-shelf device.

OBJECTIVE: A prototype ready-to-fenestrate stent graft (RFSG) was designed with a fixed scallop, and eight potential fenestrations allowing for variation in the position of each renal artery (RA) relative to the superior mesenteric artery (SMA). We aimed to determine the proportion of juxtarenal aneurysms treatable using this potentially 'off-the-shelf' device. METHODS: A total of 439 consecutive orders for custom-made devices were analysed, and positions for potential fenestrations in the RFSG were determined, based on the most frequent anatomical target vessel variations: a fixed SMA scallop 12 mm deep at 12:00, RA fenestrations at 9:15, 10:15 (target within the range 8:45-10:45), 2:15 and 3:15 (target within the range 1:45-3:45), each either 19 or 28 mm from the graft edge (GE); (within the range 15-32 mm), and 6 x 8 mm in diameter. Proximal diameters of 24, 26, 28, 30, 32 and 36 mm were chosen. RESULTS: Of the 439 plans, 372 standard juxtarenal (SJR) cases, defined by the inclusion of a scallop and 0, 1 or 2 small fenestrations (12%, 13% and 75% of the cases, respectively) were identified and used to test the applicability of the model. Mean CP (clock position) for right RA was 9:30, for the left RA 3:00, being a mean of 21 +/- 5 and 22 +/- 5 mm, respectively from the GE. RA CP was within the RFSG range in 86% (right) and 88% (left) of the cases, with 96% and 98%, respectively, within the allowable distance from the GE. A total of 81% of all SJR cases were potentially treatable using the RFSG model. CONCLUSIONS: An RFSG device would allow for the treatment of the majority of juxtarenal aortic aneurysms, which currently require custom-made devices.

Active ageing: independence through technology assisted health optimisation.

The potential doubling in the percentage of the elderly within the populations of Europe and beyond over the next decades has focused informatics research on the development Assistive Technologies and Smart Homes. However its concentration on creating a supportive home environment also has the potential for makings its users over dependent on its facilities and as a result trapped within it. This paper outlines an approach that extends the smart homes concept out into the wider community to create a smart environment that not only maintains contact with all their home-based services, but also expands these to include other facilities needed to assist them whilst on the move. This involves the convergence of physiological monitoring, communications and computing with leading-edge textile technologies, which uses a multi-layered, multi-functional clothing system as a mobile and extended variant of a smart home IP hub. In addition to variable functionality capabilities of the clothing layers in terms of thermal, shock-absorbent and other characteristics, wireless IP connectivity is provided between layers with external links typically being WiFi enabled. Health optimisation is provided by on-going lifestyle guidance/action feedback based on auto-diagnostic analysis.

Common corruption of the mTOR signaling network in human tumors.

The mammalian target of rapamycin (mTOR) is responsive to numerous extracellular and intracellular cues and, through the formation of two physically and functionally distinct complexes, has a central role in the homeostatic control of cell growth, proliferation and survival. Through the aberrant activation of mTOR signaling, the perception of cellular growth signals becomes disconnected from the processes promoting cell growth, and this underlies the pathophysiology of a number of genetic tumor syndromes and cancers. Here, we review the oncogenes and tumor suppressors comprising the regulatory network upstream of mTOR, highlight the human cancers in which mTOR is activated and discuss how dysregulated mTOR signaling provides tumors a selective growth advantage. In addition, we discuss why activation of mTOR, as a consequence of distinct oncogenic events, results in diverse clinical outcomes, and how the complexity of the mTOR signaling network might dictate therapeutic approaches.