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Background Early detection of vasospasm (VS) following aneurysmal subarachnoid hemorrhage (aSAH) is vital to trigger therapy and to prevent infarction and subsequent permanent neurological deficit. Although motor evoked potentials (MEPs) are a well-established method for intraoperative detection of cerebral VS and cerebral ischemia during aneurysm surgery, there are no studies investigating the diagnostic value of MEPs for detecting delayed VS following aSAH in an intensive care unit. Objective A prospective study was conceived to assess the diagnostic accuracy of MEPs in comparison with digital subtraction angiography. Methods MEP threshold changes were determined in patients both with and without angiographic VS following high-grade aSAHs. Sensitivity, specificity, and the positive and negative predictive values of significant MEP threshold increases, which indicate angiographic VS, were calculated. Results In all patients experiencing VS of the arteries supplying cerebral motor areas, a minimal MEP threshold increase of 50 mA (mean 66.25 mA) was observed, whereas a maximum MEP threshold increase of 30 mA was observed in patients without VS. Therefore, an increase from a baseline of ≥50 mA was considered significant and resulted in a sensitivity of 0.83, a specificity of 0.92, a positive predictive value of 0.83, and a negative predictive value of 0.92. Conclusion VS following aSAH can be detected accurately by using MEPs. MEPs are a feasible bedside tool for online VS detection in an intensive care unit and, therefore, may complement existing diagnostic tools.

Primary intramedullary spinal glioblastoma multiforme (sGBM) with a secondary cerebral manifestation is a very rare entity with a poor outcome. Case studies show a mean average of survival of 10 months after diagnosis. These tumors tend to develop at a young age. A combination with an arteriovenous malformation in the same location has never been published before. Vascular malformations in association with cerebral glioblastomas have only been reported in five cases so far. Proangiogenic factors are assumed to be involved in the appearance of both entities. We present a case study and a review of the literature.

Background Intraoperative imaging of cerebral aneurysms may be desirable in emergency situations with large space-occupying hematomas or to visualize vessels after clip placement. Mobile 3-dimensional fluoroscopes are available in a number of neurosurgical departments and may be useful in combination with simple image postprocessing to depict cerebral vessels. Objective To assess whether intracranial aneurysms are detectable with appropriate image quality with intraoperative 3-dimensional fluoroscopy with intravenous contrast administration. Methods Eight patients were included in the study. The patients' heads were fixed in a radiolucent Mayfield clamp. First, a rotational fluoroscopy scan was performed without contrast agent. Then, a second scan with 50 mL iodine contrast agent was performed. The DICOM (digital imaging and communications in medicine) data of both scans were transferred to an Apple PowerMac workstation, subtracted, and reconstructed with OsiriX imaging software. The images were compared with preoperative angiograms. Results No adverse effects were observed during contrast administration. The entire procedure from fluoroscope positioning to the production of usable 3-dimensional images took 5 to 6 minutes with an image acquisition time of 2 × 24 seconds. The configuration of the aneurysm and the vessel anatomy were assessable. Previous coiling limited image quality in 1 patient. Conclusion This technique quickly provides images of adequate quality to assess the configuration of intracranial aneurysms, which may be helpful when immediate intraoperative information about intracranial vessel pathologies is required. The positioning of the fluoroscope, image acquisition, and processing can be completely integrated into the surgical workflow.

Hip pain in young adults is not always caused by intra-articular pathology, even in the presence of abnormal examination and imaging findings. Therefore, management of young adult hip pain requires processes that identify patients who are likely to benefit from surgical intervention. An important investigation in the diagnostic pathway is the intra-articular injection; a negative response to this should alert the surgeon to the presence of symptomatic extra-articular causes of hip pain. Our aim was to identify the proportion of patients referred with intra-articular pathology whose primary cause of pain was of extra-articular origin. A total of 143 intra-articular hip injections (local anaesthetic + corticosteroid) were performed over a 2-year period. Mean patient age was 41.95 (95% confidence interval: 39.50–44.41) years with a mean body mass index of 27 (95% confidence interval: 25.77–28.23); 26% of patients (n = 37) had no relief of symptoms after intra-articular injection. Of the patients with no relief, 81.1% (n = 30) were found to have extra-articular pathology as the cause of their pain and the remainder are under on-going investigation. Intra-articular hip injection is an important investigation in the diagnostic pathway of young adult hip pain, as it can highlight and differentiate those patients with referred pain from extra-articular pathology. This benefit may be further enhanced if injections are performed in theatres using image intensifier, under sedation, as it allows direct penetration into the joint without any local anaesthetic infiltration of surrounding tissue. The latter allows immediate objective assessment of symptom relief, eliminating the need to rely on retrospective patient recall of symptom change.

Patient reported outcome measures (PROMs) are used to gauge clinical performance. The PROMs outcome programme at our centre achieves a preoperative data capture rate of 99%. This falls to 90.6%, 89%, 83% and 79% at the six-week, six-month, one-year and two-year time points, respectively. The study aims were to determine factors associated with patients who did not respond to outcome questionnaires following total hip replacement (THR), and the potential implications this may have when assessing patients following THRs. During the first year of the PROMs programme, 1,322 patients underwent unilateral primary THR at our institution. Of these, 1,311 completed preoperative questionnaires. Thirty-eight patients (2.9%) died within two years of surgery and have been excluded. For the remaining 1,273 patients, we identified those who did not return postoperative questionnaires at each of our review time points. Younger age, lower baseline EQ5D and Oxford Hip scores (OHS) were significantly associated with non-response (p

This study aimed at describing the anatomy of the zona orbicularis (ZO), based on magnetic resonance arthrography (MRA) and magnetic resonance imaging (MRI) scans and to assess the presence of synovial folds in relation to the ZO. A retrospective review was performed using consecutive hip and pelvic MRA and MRI examinations from our institution. We identified 25 normal scans of each variety. Patients were scanned in a neutral hip position and 3D FIESTA sequence images were included in a number of cases. Using electronic callipers, measurements were obtained of the ZO thickness and of the location of the ZO with respect of the femoral head and neck. On MRA, the ZO appeared as a horseshoe in 18/25 patients, being absent anteriorly. On MRI the ZO was less consistent and absent in 12/25 posteriorly, in 8/25 inferiorly and in 2/25 anteriorly. Where present, the ZO usually coincided with the boundary of femoral head sphericity and the narrowest point of the isthmus of the femoral neck. The medial synovial fold was identified in all MRA studies (25/25). The ZO of the hip is most consistently identified when the joint is distended and in approximately 75 % of cases appears as a horseshoe-shaped structure. Superiorly, the ZO is aligned perpendicular to the long axis of the femoral neck. The ZO twists from postero-lateral to antero-medial as it moves inferiorly. Our findings are consistent with the hypothesis that the ZO functions as a ring that resists femoral head distraction and contributes to dynamic circulation of synovial fluid.

Metastasis is the most lethal attribute of cancer,1 and activation of invasion and metastasis is one of the hallmarks of cancer cells.2 Proliferation, deregulated adhesion, increased invasiveness, motility, resistance to apoptotic signals, and the ability to induce angiogenesis are characteristics of metastatic cells.2 Recently, metastasis-associated in colon cancer 1 (MACC1) has been discovered as an independent prognostic indicator of metastasis formation and metastasis-free survival for colon carcinoma patients.3 MACC1 expression is upregulated in malignant colon cancer tissues compared with normal tissues, like colon mucosa or liver, and occurs mainly at the crucial step of transition from the benign to the malignant phenotype.4 It induces cell migration, invasion, proliferation, colony formation, wound healing, and hepatocyte growth factor (HGF)–triggered scattering of colon cancer cells in cell culture. In tumor xenografts it causes tumor growth and metastasis.3,5 It is also discussed that it might be involved in the regulation of apoptosis.6 Mining of databases revealed high MACC1 expression not only in colorectal cancer, but also in pancreatic, ovarian, endometrial, cervical, breast, lung, liver, esophageal, and head and neck cancers.7 Meanwhile, different tumor entities have been analyzed for MACC1 expression by quantitative real-time reverse transcription (RT ) PCR and immunohistochemistry.8 Increased MACC1 expression was shown in advanced colorectal carcinomas,9–11 peritoneal-disseminated gastric carcinomas,12 recurrent lung adenocarcinomas,13,14 and vascular invasive hepatocellular carcinomas.15,16 To the best of our knowledge, there are no data on MACC1 expression in human astrocytic tumors available yet. Diffuse low-grade astrocytomas (LGAs) of World Health Organization (WHO) grade II are well-differentiated tumors with diffuse infiltration of the adjacent brain parenchyma.17 Most of these tumors progress to anaplastic astrocytomas of WHO grade III or glioblastoma multiforme (GBM) of WHO grade IV within 4–5 years after diagnosis.18 This secondary GBM is distinguished from primary GBM, which arises de novo without detectable precursor lesion.19–21 However, GBM are the most prevalent, highly malignant, invasive, and difficult to treat primary brain tumors of adults. The treatment regimens of patients with GBM include neurosurgical tumor resection followed by local γ-irradiation and chemotherapy.17 However, in spite of multidisciplinary treatment, the median survival is only 14.6 months.22,23 Therefore, it is vital to identify new potential therapeutic targets for future therapies. Although these tumors rarely metastasize, their invasive and migratory behaviors are very similar to those of metastatic cells of tumors originating from other tissues. Thus, we hypothesized that MACC1 may also be involved in progression of human gliomas. This hypothesis was supported by the fact that HGF and its receptor c-Met have been shown to be upregulated in high-grade astrocytic tumors,24 thereby inducing migration of their cells.25–28 MACC1 binds to the Sp1 site of the c-Met promoter, controls c-Met promoter activity and expression, and thereby regulates c-Met–mediated signaling.29 Indeed, HGF/c-Met is one of the major signaling cascades regulated by MACC1 in colorectal cancer and is of major importance for both the malignant transformation and metastatic potential of colorectal tumor cells.30 Here we report that MACC1 overexpression promoted proliferation and migration of GBM cells in cell culture. Furthermore, MACC1 overexpression increased the rates of tumor formation in organotypic hippocampal slice cultures (OHSCs) derived from C57BL6/J mice, probably via upregulation of c-Met, as shown by crizotinib inhibitor experiments. In human malignant gliomas, MACC1 expression increased concomitantly with increasing WHO grade. Moreover, MACC1 expression levels allowed discrimination of dormant and recurrent LGAs and of primary and secondary GBM. Most importantly, strong MACC1 protein expression was associated with reduced patient survival. Taken together, these data indicate that MACC1 may represent a promising new biomarker for prognostication and a target for inhibition of proliferation and migration of astrocytic tumor cells.

The long Irish oak tree-ring chronology, developed for archaeological dating and radiocarbon calibration, is the longest of any in northwest maritime Europe, spanning most of the Holocene (7,272 years). Unfortunately, the rings widths do not carry a strong climate signal and the record hasnever been satisfactorily applied for dendroclimatic reconstruction. This pilot study explores the potential for extracting a climate signal from Irish oaks by comparing the stable oxygen isotopes ratios from 10 oak tree cores (Quercus robur and Quercus petraea L.) collected across the Armagh region of NE Ireland with local and regional climatic and stable isotopic data. Statistically significant correlations between isotope ratios and the amount of summer precipitation (r = -0.44) point to the isotopic composition of summer rainfall as the dominant signal. Including the Armagh data into an extended regional oxygen isotope series did not reduce the correlation coefficient with regional precipitation (r = -0.68, p < 0.01). Correlations of this magnitude in dendro-hydroclimatology are typically restricted to trees growing at their ecological limits. This research suggests that there is considerable potential for including living trees and ancient timbers from Ireland into a regional composite to reconstruct the summer hydroclimate of Britain and Ireland.

The strongly implicit procedure is used to model the diffusion-only chronoamperometric responses of microband electrode geometries which deviate from the ideal. Specifically, attention is focused on four electrode shapes: elevated microband electrodes (with conducting supporting sides), recessed microband electrodes (with insulating pit walls), platform electrodes (with insulating supporting sides) and, for the purposes of comparison, a hypothetical line electrode without any support which permits diffusional mass transport to both sides of the infinitesimally thin electrode. In all cases the short time transient is found to be described by simple analytical expressions in which the contributions from linear diffusion over the electrode area(s) and non-linear diffusion to the electrode perimeters are clearly distinguishable. © 1995 Elsevier Science S.A. All rights reserved.

A quantitative study of the hydrolytic dissolution of solid p-chloranil at alkaline pH using a combination of the channel flow cell and in situ atomic force microscopy measurements shows that the dissolution is driven by reaction of the substrate with hydroxide ions at, or very close to, the dissolving surface. The dissolution rate equation, deduced from the channel flow cell for single crystals of p-chloranil, is rate/mol cm-2 s-1 = 3.8 × 10-7[OH-]0 where [OH-]0/M is the hydroxide ion concentration adjacent to the solid surface. An analogous rate law is derived for pressed pellet substrates. The novel application of the atomic force microscope to make absolute measurements of surface averaged dissolution rates is described. Comparison with the independent channel flow cell data reveals good mechanistic agreement and consistency of rate constants provided it is recognised that a thick stagnant diffusion layer can be present under the usual conditions employed for AFM. © 1997 Elsevier Science S.A.

Analytical theory is presented which allows rigorous mass transport-corrected Tafel analysis for the reversible electrode processes (1) 2B ⇄ A2 + 2e− and (2) B2 ⇄ 2A + 2e− occurring at electrodes in flowing systems. Predictions are compared with the conclusions of numerical finite-difference modelling for both wall-jet and channel flow cell geometries. Exceillent agreement is found.

The hydroxide-driven dissolution of the polymer hydroxypropyl methylcellulose phthalate (HPMCP) in aqueous solution is studied using atomic force microscopy. The novel technique of employing the surface-averaged z-piezo voltage as a direct measure of the mean absolute surface height is described, so as, after appropriate calibration, to permit the ready inference of dissolution fluxes. In the case of interest the following dissolution rate law was established: j/g·cm-2·s-1 = 105.0[OH-] over the pH range 8.0−9.2, where j is the flux of the dissolving polymer and [OH-] is measured in mol cm-3.

The amount of fluid that may be lost into the soft tissues during hip arthroscopic surgery is unknown. We measured the volumes of irrigation fluid infused, operating time, fluid pressures and volumes of fluid recovered in 36 therapeutic hip arthroscopies. We excluded those where fluid was lost to the floor, leaving 28 patients. The majority were undergoing surgery for the treatment of femoroacetabular impingement. In 5 patients an intra-articular contrast medium was instilled, in order to establish the likely location of any extravasated fluid. The mean operating time was 68 minutes (31 to 120), and the mean infusion pressure was 46 mm Hg (30 to 70). The mean volume of infused fluid was 9677 ml (95% confidence interval (CI) 7715 to 11638) and the mean volume of fluid recovered was 8544 ml (95% CI 6715 to 10373). The mean fluid extravasation loss into the peri-articular tissues was 1132 ml (95% CI 808 ml to 1456 ml). There was a significant correlation between the volume of extravasated fluid and both the length of operation and the volume of infused fluid used. We had no adverse events in our series. During arthroscopic hip surgery more than a litre of irrigation fluid may be extravasated into the soft tissues. In order to reduce problems related to this we attempt to keep operating times low, and maintain intra-operative fluid pressures as low as possible.

To examine whether the maintenance of elevated magnesium serum concentrations by intravenous administration of magnesium sulfate can reduce the occurrence of cerebral ischemic events after aneurysmal subarachnoid hemorrhage.Prospective, randomized, placebo-controlled study.Neurosurgical intensive care unit of a University hospital.One hundred ten patients were randomized to receive intravenous magnesium sulfate or to serve as controls. Magnesium treatment was started with a bolus of 16 mmol, followed by continuous infusion of 8 mmol/hr. Serum concentrations were measured every 8 hrs, and infusion rates were adjusted to maintain target levels of 2.0-2.5 mmol/L. Intravenous administration was continued for 10 days or until signs of vasospasm had resolved. Thereafter, magnesium was administered orally and tapered over 12 days.Delayed ischemic infarction (primary end point) was assessed by analyzing serial computed tomography scans. Transcranial Doppler sonography and digital subtraction angiography were used to detect vasospasm. Delayed ischemic neurologic deficit was determined by continuous detailed neurologic examinations; clinical outcome after 6 months was assessed using the Glasgow outcome scale. Good outcome was defined as Glasgow outcome scale score 4 and 5.The incidence of delayed ischemic infarction was significantly lower in magnesium-treated patients (22% vs. 51%; p = .002); 34 of 54 magnesium patients and 27 of 53 control patients reached good outcome (p = .209). Delayed ischemic neurologic deficit was nonsignificantly reduced (9 of 54 vs. 15 of 53 patients; p = .149) and transcranial Doppler-detected/angiographic vasospasm was significantly reduced in the magnesium group (36 of 54 vs. 45 of 53 patients; p = .028). Fewer patients with signs of vasospasm had delayed cerebral infarction.These data indicate that high-dose intravenous magnesium can reduce cerebral ischemic events after aneurysmal subarachnoid hemorrhage by attenuating vasospasm and increasing the ischemic tolerance during critical hypoperfusion.

This study examines current subglacial biogeochemical weathering models using PHREEQCi, a computer-based speciation mass-balance (SMB) model, parameterized using hydrochemical and mineralogical field data from Haut Glacier d'Arolla, Switzerland. The aim is to investigate the utility of SMB models for quantifying subglacial biogeochemical mechanisms, and the mathematical and thermodynamic robustness of current subglacial weathering models in a temporally variable, spatially heterogeneous hydrological and geochemical subglacial environment. The chemical evolution of meltwaters between their source in the supraglacial environment and their output from the hydroglacial system as bulk meltwaters are modeled, and compared with in situ meltwaters collected from the base of boreholes drilled to the glacier bed. SMB modeling produced a broad range of weathering outcomes, but delivered no unique weathering scenario which could account for the observed changes in water chemistry between input and output wat...