Search

Introduction EXCELLENT (NCT03685578) is a prospective, single-arm, multicenter, real-world international registry of mechanical thrombectomy (MT) for stroke with the EmboTrap device as first line treatment. The study entails thrombus analysis of specimens collected with each MT pass. Aim of the Study To compare rates of mRS 0–2 at 90 days and clot characteristics in subjects with and without first pass effect (FPE). Methods FPE was defined as mTICI 2c/3 after one pass and non-FPE as mTICI 2c/3 after >1 pass as adjudicated by an independent core lab. Clot analysis was performed by independent central labs blinded to clinical data. mRS at 90 days was scored by investigators blinded to procedural data. Results Overall mTICI2c/3 rates were 63.7% (326/512). FPE was achieved in 37.1% (190/512) and non-FPE in 26.6% (136/512) subjects. 90 day mRS 0–2 or equal to pre-stroke was achieved in 47.2% (75/159) with FPE and in 42.1% (51/121) non-FPE patients. All-cause 90-day mortality was 19.1% (34/178) in subjects with FPE and 26.4% (34/129) in subjects with non-FPE. Major thrombus components (mean% ±SD) were as follows: RBC: FPE 45.88±20.54, non-FPE 39.08±18.23, and first pass mTICI Conclusions The high rate of ‘real-world’ FPE observed in EXCELLENT was associated with improved clinical outcomes. Clots retrieved with FPE had higher RBC and lower fibrin content compared to non FPE and to first pass mTICI Disclosure EXCELLENT is sponsored by Cerenovus. Dr. Jovin is a consultant for Neuravi, Codman Neurovascular, Stryker (PI DAWN; unpaid), Fundacio Ictus (PI REVASCAT; unpaid), and holds stock in Anaconda, Silk Road, and Blockade Medical.

Introduction: Red blood cell (RBC) rich vs fibrin rich clots have different mechanical properties and greater knowledge about clot composition in the context of clinical, imaging, and procedural factors in mechanical thrombectomy (MT) may help with procedural optimization. The EXCELLENT Registry (NCT03685578) is a prospective, global, multi-center, observational registry of EmboTrap as the first line MT device for large vessel occlusion (LVO). We present an interim analysis of clot collected per pass in the registry. Methods: Five hundred thirty-three clot specimens from 376 subjects were collected by 20 sites and sent for analysis by independent Central Labs under standardized protocol. Analysis was interrupted by COVID-19, but the labs were fully operational as of June 2020 and on track to deliver results for 300 subjects in Q4. At the time of abstract submission, composition data for 234 clots from 163 subjects was available. All available data will be presented at the time of the conference. Results: Cardioembolic etiology (n=100) was associated with lower RBC (40.2 vs 47.2%) and higher fibrin content (31.7 vs 26.7%) compared to large artery disease (n=12). Hyperdense/vessel susceptibility sign (78+, 24-, per independent imaging core lab) corresponded to higher mean RBC content (44.4 vs 34.9%). Treatment with IV tPA (60+, 91-) had no clear impact on clot composition (42.3 vs 40.6% RBC; 30.4 vs 30.0% fibrin). Notably, clots retrieved with the first 2 passes of were more RBC rich (42.1 vs 28.0%) and clots retrieved in higher passes had a higher average fibrin content (35.5 vs 29.6%) suggesting that higher fibrin content leads to greater refractoriness. Conclusions: Clot density/susceptibility on baseline imaging, stroke etiology and number of thrombectomy passes were associated with differential clot composition. These findings may have potential implications for the development of better MT strategies.

BACKGROUND Although empiric treatment of urinary tract colonized patients remains a frequent practice in neurosurgery, the value of this practice remains debatable. OBJECTIVE To analyze the effect of screening and treatment of bacteriuria on surgical site infections, incidence of Clostridium difficile, and mortality in neurosurgical trauma patients. METHODS Database queries and direct patient chart reviews were used to gather patient chart data. T-tests, chi-square tests, binary logistic regressions, and propensity matched cohorts comparisons were performed. RESULTS A total of 3563 admitted neurosurgical trauma patients were identified over an 8 yr period (1524 cranial, 1778 spinal, and 261 combined craniospinal diagnoses). Nine hundred ninety-one patients underwent an operative neurosurgical procedure. Urinalysis was significantly associated with antibiotics exposure in both operative and nonoperative patients (P < .001). Operative patients treated with empiric antibiotics did not have a reduced risk of wound infection (P = .21), including in a propensity matched cohort (P = .52). Patients treated with empiric antibiotics had significantly increased rates of C. difficile infection (P < .001). At last follow-up, neurosurgical trauma patients that developed C. difficile had an increased risk of death (P < .005); antibiotic exposure and death were also significantly associated (P = .018). The association of C. difficile with empiric antibiotics remained significant in a propensity-matched cohort (P = .0024). CONCLUSION The routine use of urinalysis and empiric urinary antibiotics for bacteriuria in neurosurgical trauma patients without urinary symptoms increases risk of exposure to antibiotics does not decrease rates of wound infection, and is associated with increased rates of C. difficile infection and death.

Acute ischemic stroke is a disease with an immense global impact. The past 30 years have seen an explosion in diagnostic and therapeutic options that has changed the way stroke is treated. Here we review the scientific evidence for acute ischemic stroke therapy, discuss new treatment algorithms and systems of care, and also review the available imaging modalities utilized for patient selection as well as endovascular devices/techniques that are employed to treat acute large vessel intracranial occlusions, one of the most difficult subtypes of acute ischemic stroke to treat.

Woven fabrics are widely used in various protective applications. The effects of different woven architectures (such as plain, basket, twill and satin) on impact resistance performance have not been adequately studied. In this work, high-speed impact testing on single layer plain weave structures has been carried out using a gas gun experimental setup. Ballistic resistance performance of the woven fabric is evaluated based on the resultant velocity of the projectile, as well as the post-mortem failure analysis. Finite element computational models are presented in this research, thereby providing predictive capability for the manufacturer and designer in order to minimise field testing, as well as shedding light on to the damage mechanisms of composite fabrics subjected to ballistic impact. The numerical model is validated with the experimental results in terms of dissipated energy and resultant velocity. Numerical investigation is conducted on other woven structures of identical areal density for comparison, revealing the importance of fabric architecture. The influences of yarn-yarn and yarn-projectile friction properties on the ballistic performance of various textile structures are also presented.

Carbon nanotubes (CNTs), particularly of the substrate-grown directly spinnable variety, have a vast number of potential applications. We have devised a recycling methodology to enable the evolution of catalyst morphology and activity and its effect on CNT growth quality and failure to be studied incrementally. Direct spinnability is particularly sensitive to many variables and so provides verification that each cycle is essentially identical. Two processes, utilising acetylene with and without hydrogen, are studied. Acetylene alone gives four cycles of spinnable CNTs before failing abruptly at the fifth at which point catalyst particle (and CNT) areal density increase while CNT diameter and length fall sharply. In contrast, addition of hydrogen doubles the initial growth rate but spinnability declines on the third cycle and fails on the fourth as catalyst (and CNT) areal density decreases sharply. CNT length also falls although diameter increases. Our observations support a proposed ‘sinking plateau’ model of catalyst behaviour where growth rate is driven by the essentially flat accumulation area or ‘plateau plain’ surrounding a local high spot (active catalyst particle). The growth rate remains stable until the plateau plain drops below the substrate surface through diffusion at the base, at which point it falls sharply.

Composite textiles composed of materials such as Kevlar, Dyneema and Zylon are extensively used in many force/impact protection applications, such as body armor, and automobile and airplane engine fragment resistant containment. Significant effort has been devoted to ballistic testing of composite fabrics made from various manufacturing processes and designs. Performing comprehensive ballistic and impact tests for these composite textiles is a very time-consuming and costly task. Numerical models are presented in this research, thereby providing predictive capability for the manufacturer and designer to minimize field testing, as well as shedding light on to the damage mechanisms of composite fabrics subjected to ballistic impact. Several representative composite fabric architectures (such as plain weave, basket weave and knitted fabrics) are generated for finite element analysis. Numerical investigation is conducted on these fabric structures of the same mass per unit area subjected to projectile impacts. Failure patterns of woven and knitted fabrics obtained from numerical simulations are compared with those observed experimentally. Performances of the representative textile structures are evaluated based on the resultant velocity of the projectile, as well as various energy components. The influences of yarn–yarn and yarn–projectile friction properties on the ballistic performance of various textile structures are presented. To highlight the effects of projectile geometry and angular rotation on the fracture of woven and knitted fabrics, a series of simulations are also performed with three distinctive projectiles of the same mass and impact energy.

We report a method of improving the alignment of carbon nanotubes (CNTs) in a solid strand prepared from a CNT forest without dispersing and regrouping them. The use of a lubricant loosens the interconnections between the carbon nanotubes so that they can slide relative to each other and align themselves longitudinally. A highly stretchable polymer gel fibre is used as a carrier to apply the lubricant to a continuous length of the carbon nanotube strand so that the strand can be drawn uniformly and continuously by a series of drawing operations. The lubricant is then extracted to produce a highly aligned carbon nanotube reinforced polymer composite fibre that demonstrates a remarkable reinforcement effect. The CNT strength utilisation in the composite fibre is one order of magnitude greater than that in a pure carbon nanotube spun yarn.

We report a new method to create covalent crosslinks between carbon nanotubes (CNTs) with reduced intertube and interbundle spaces, for improving the mechanical properties of CNT spun yarns. This is achieved through the pretreatment of a CNT yarn with 4-carboxybenzenediazonium tetrafluoroborate to form reactive carboxyphenyl groups on the CNT sidewalls. These carboxyphenyl groups are then reacted with a multifunctional crosslinker hexa(methoxymethyl) melamine, leading to a highly crosslinked network within the yarn. The CNT yarns were characterized by X-ray photoelectron spectroscopy, focused ion beam scanning electron microscope, and also assessed for their mechanical properties. The results showed that the method developed effectively improved mechanical properties of CNT yarns: we are able to produce CNT yarns with a tensile strength up to 2.5 GPa and Young’s modulus 121 GPa.

We report a method for modifying carbon nanotube (CNT) spun yarns with aryldiazonium salts that involves the pH controlled application of the diazonium salts to CNTs both during and after the yarn formation process. This largely facilitates the chemical accessibility to CNTs within the yarn, potentially enabling a more extensive and uniform modification. The modified CNT yarns were characterised by X-ray photoelectron spectroscopy, Raman spectroscopy and scanning electron microscopy, and also examined for their mechanical properties. The results demonstrated that a CNT spun yarn was effectively modified by this method without impairing the yarn integrity. The formation of oligomerised polyene structures on the CNT surfaces was observed. This modification resulted in an increase in tensile strength and Young’s modulus of the CNT yarn. The functional groups grafted on CNTs also provide opportunities to form crosslinks in the yarn to further improve mechanical properties.

We present the case of a 19-year-old man who suffered a penetrating injury to the brain with a large-calibre steel industrial prybar approximately 1 m long and 2.5 cm wide that was retained in his cranium. The management of this type of injury is discussed, based on our experience with penetrating brain injuries with large-calibre retained objects, from initial presentation to surgical removal of the object to post-operative care. Additionally, given the similarities of the injuries suffered by our patient with those of Phineas Gage, we discuss the extensive lessons learned in treating this type of large-calibre injury.

Carbon nanotubes (CNTs) grown on substrate-bound catalysts by CVD are influenced by the catalyst, which changes over the course of the process. The evolution of the CNT growth is revealed by breaking the process into recycling increments and using the phenomenon of ‘direct spinnability’ as a target characteristic. Using acetylene alone, it was found that the first four cycles gave 100% regrowth in height and mass yield of CNTs, with both properties falling to around 20% on the 5th cycle. A decrease in nanotube diameter was observed whilst the areal density increased. With the addition of hydrogen a 100% regrowth for the second cycle was observed, followed by a decrease to around 55%, 18% and 11% in both height and yield for subsequent cycles. The diameter increased, whilst the areal density decreased in subsequent cycles. In the absence of hydrogen the CNTs have around seven walls, decreasing to about three by the seventh cycle. With hydrogen, CNTs have five or six walls for all cycles. Raman spectroscopy indicates an increase in disorder in later cycles. Spinnability is high for initial cycles but drops sharply on the fourth cycle, or third cycle with hydrogen, as the nanotube forest tortuosity markedly increases.

The effect of twist and solvent densification on the internal structure of carbon nanotube yarns was revealed using focused ion beam milling and related to yarn strength through tensile testing. Denser carbon nanotube yarns with smaller diameters were produced either through solvent densification or with increasing twist densities from 5 to ∼15 turns/mm, but led to only minor improvement in yarn tenacity. At twist densities greater than ∼15 turns/mm, a core-sheath structure developed and was correlated with a decline in strength. The implications of bonding between the nanotubes in the twisted yarn are briefly considered. These results have implications for the future development of high strength carbon nanotube yarn.

Myofibroblastic tumors are soft-tissue neoplasms arising from myofibroblasts, ubiquitous cells sharing ultrastructural features of muscular and fibroblastic cells. Vasudev and Harris described a malignant counterpart of these benign tumors in 1978. Most reported cases of myofibroblastic sarcoma have arisen in the head and neck region and the soft tissues of the extremities. To the best of the authors' knowledge, there have been only 8 previous reports on primary myofibroblastic sarcoma of the bone. The authors report a new case of this rare tumor affecting the sacrum and ilium of a 15-year-old girl and discuss the role of total sacrectomy and lumbopelvic reconstruction for treatment of this disease.

A modified process for the dry spinning of carbon nanotube (CNT) yarn is reported. The approach gives an improved structure of CNT bundles in the web drawn from the CNT forest and in the yarn produced from the twisted web leading to improved mechanical properties of the yarn. The process enables many different mechanical and physical treatments to be applied to the individual stages of the pure CNT spinning system, and may allow potential for the development of complex spinning processes such as polymer–CNT-based composite yarns. The tensile strength and yarn/web structure of yarn spun using this approach have been investigated and evaluated using standard tensile testing methods along with scanning electron microscopy. The experimental results show that the tensile properties were significantly improved. The effect of heat treatments and other yarn constructions on the tensile properties are also reported.

✓The authors describe the case of a 36-year-old woman with bilateral internal jugular vein occlusion, hydrocephalus, and Dandy–Walker variant who presented with myelopathy that was ultimately attributed to ventriculoperitoneal (VP) shunt failure. Computed tomography (CT) angiography of the head and neck revealed epidural venous engorgement within the cervical spine, greater that 50% narrowing of the C2–5 spinal canal, and compression of the cervical spinal cord. After successful shunt revision, postoperative CT angiography revealed decreased venous engorgement as well as decompression of the cervical spinal cord, and the patient’s myelopathy improved. This case represents a fascinating clinical presentation of VP shunt failure, highlighting the physiological importance of the external jugular pathways involved in cerebral venous drainage.

Background: Residual aneurysm after microsurgical clipping carries a risk of aneurysm growth and rupture. Digital subtraction angiography (DSA) remains the standard to determine the adequacy of clipping. Intraoperative indocyanine green (ICG) angiography is increasingly utilized to confirm optimal clip positioning across the neck and to evaluate the adjacent vasculature. Objective: We evaluated the correlation between ICG and DSA in clipped intracranial aneurysms. Methods: A retrospective study of patients who underwent craniotomy and microsurgical clipping of intracranial aneurysms with ICG for 2 years. Patient characteristics, presentation details, operative reports, and pre- and postclipping angiographic images were reviewed to determine the adequacy of the clipping. Results: Forty-seven patients underwent clipping with ICG and postoperative DSA: 57 aneurysms were clipped; 23 patients (48.9%) presented with subarachnoid hemorrhage. Nine aneurysms demonstrated a residual on DSA not identified on ICG (residual sizes ranged from 0.5 to 4.3 mm; average size: 1.8 mm). Postoperative DSA demonstrated no branch occlusions. Conclusion: Intraoperative ICG is useful in the clipping of intracranial aneurysms to ensure a gross patency of branch vessels; however, the presence of residual aneurysms and subtle changes in flow in branch vessels is best seen by DSA. This has important clinical implications with regard to follow-up imaging and surgical/endovascular management.

We describe a minimalist approach to perform in situ decompression of the ulnar nerve. Our technique employs a unique small skin incision strategically placed to minimize postoperative scarring over the ulnar nerve and potentially decrease the risk of iatrogenic injury to the medial antebrachial cutaneous nerve. We retrospectively report the outcome of patients who have undergone this procedure at our institution, the Michael E. DeBakey Veterans Affairs Medical Center, from January 1 2007 through November 29 2010. All individuals underwent in situ decompression via the previously described minimalist approach. Outcome variables were Louisiana State University Medical Center (LSU) ulnar neuropathy grade, patient satisfaction, subjective improvement, complications and re-operation rate. A total of 44 procedures were performed in this cohort of 41 patients. Overall, patients’ postoperative LSU grades showed a statistically significant improvement (p = 0.0019) compared to preoperative grades. Improvement of at least one grade in the LSU scale was observed in 50% of the procedures with a preoperative grade of four or less. Overall procedure satisfaction rate was 88% (39 of 44) with 70% (31 of 44) of the procedures resulting in improvement of symptoms. There were no intraoperative or postoperative complications. One patient required re-operation due to failure of neurological improvement. Our minimalistic approach to perform in situ decompression of the ulnar nerve at the cubital tunnel is both safe and effective. We observed a statistically significant improvement in LSU ulnar neuropathy grades and a success rate comparable to those reported for other more extensive surgical techniques while providing the benefit of a smaller incision, less scarring, decreased risk of iatrogenic nerve injury and minimal complications.

We report an adult female with a small cell lung cancer (SCLC) pituitary metastasis who presented with seizures and headache. While headache is a common presentation of pituitary metastases, seizures have been very rarely reported. The patient was found on MRI to have a suprasellar tumor with pituitary infundibulum involvement. She underwent endoscopic transsphenoidal resection of the tumor which was shown to be metastatic SCLC. Subsequent imaging revealed widespread systemic metastases. The patient subsequently underwent chemotherapy.

Objective Flexible large lumen aspiration catheters and stent retrievers have recently become available in the USA for the revascularization of large vessel occlusions presenting within the context of acute ischemic stroke (AIS). We describe a multicenter experience using a combined aspiration and stent retrieval technique for thrombectomy. Design A retrospective analysis to identify patients receiving combined manual aspiration and stent retrieval for treatment of AIS between August 2012 and April 2013 at six high volume stroke centers was conducted. Outcome variables, including recanalization rate, post-treatment National Institutes of Health Stroke Scale (NIHSS) score, symptomatic intracranial hemorrhage, discharge 90 day modified Rankin Scale (mRS) score, and mortality were evaluated. Results 105 patients were found that met the inclusion criteria for this retrospective study. Successful recanalization (Thrombolysis in Cerebral Infarction score 2B) was achieved in 92 (88%) of these patients. 44% of patients had favorable (mRS score 0–2) outcomes at 90 days. There were five (4.8%) symptomatic intracerebral hemorrhages and three procedure related deaths (2.9%). Conclusions Mechanical thrombectomy utilizing combined manual aspiration with a stent retriever is an effective and safe strategy for endovascular recanalization of large vessel occlusions presenting within the context of AIS.

Focused ion beam (FIB) milling through carbon nanotube (CNT) yarns and bucky-papers followed by scanning electron microscopy has recently emerged as a powerful tool for eliciting details of their internal structure. The internal arrangement of CNTs in bucky-papers and yarns directly affects their performance and characteristics. Consequently this information is critical for further optimisation of these structures and to tailor their properties for specific applications. This chapter describes in detail FIB milling of CNT yarns and bucky-papers and gives a range of examples where FIB milling has enabled a better understanding of how processing conditions and treatments affect the internal structure. Emphasis is placed on how FIB milling elucidates the influence of fabrication conditions on the internal arrangement of CNTs and how this influences the material’s macroscopic properties.

Cerebral air embolism is a dreaded complication of invasive medical procedures. The mainstay of therapy for patients with cerebral air embolism has been hyperbaric oxygen therapy, high flow oxygen therapy, and anticonvulsants. We present a novel therapeutic approach for treatment of cerebral air embolism causing large vessel occlusion, using endovascular aspiration. Our patient developed a cerebral air embolism following sclerotherapy for varicose veins. This caused near total occlusion of the superior division of the M2 segment of the right middle cerebral artery. Symptoms included unilateral paralysis, unintelligible speech, and hemianopia; National Institutes of Health Stroke Scale (NIHSS) on presentation was 16. The air embolism was treated using a distal aspiration technique. Angiography following aspiration showed Thrombolysis in Cerebral Infarction 2B reperfusion. Following aspiration, the patient was re-examined; NIHSS at that time was 4. At 1 month follow-up, the modified Rankin Scale score was 1 and NIHSS was 1. Treatment of cerebral air embolism is discussed.

Object Intracranial hemorrhage (ICH) is a frequent complication found in leukemia patients with thrombocytopenia. At the University of Texas MD Anderson Cancer Center, when a leukemia patient is found to have ICH, a platelet transfusion is generally recommended until 50,000/μl is reached. The authors examine the feasibility and outcome of their intervention strategy in this study. Methods Records were reviewed from 76 consecutive leukemia patients with newly diagnosed ICH at the University of Texas MD Anderson Cancer Center from January 1, 2007, to December 31, 2009. Variables of interest included age, platelet count at presentation, leukemia subtype, history of trauma, Glasgow Coma Scale score at presentation, whether the 50,000/μl goal was reached after transfusion, and whether the patient was a transfusion responder (platelet count increase > 2000/μl/unit transfused). Outcome parameters were mortality rates at 72 hours and 30 days and imaging-documented hemorrhage progression. Results Thrombocytopenia was prevalent at the time of presentation (68 of 76 patients had platelet levels < 50,000/μl at presentation). Despite an aggressive transfusion protocol, only 24 patients reached the 50,000/μl target after an average of 16 units of transfusion. Death due to ICH occurred in 15 patients within the first 72 hours (mortality rate 19.7%). Death correlated with the presenting Glasgow Coma Scale score (p = 0.0075) but not with other transfusion-related parameters. A significant mortality rate was again observed after 30 days (32.7%). The 30-day mortality rate, however, was largely attributable to non-ICH related causes and correlated with patient age (p = 0.032) and whether the patient was a transfusion responder (p = 0.022). Reaching and maintaining a platelet count > 50,000/μl did not positively correlate with the 30-day mortality rate (p = 0.392 and 0.475, respectively). Conclusions Platelet transfusion in the setting of ICH in leukemia patients is undoubtedly necessary, but whether the transfusion threshold should be 50,000/μl remains unclear. Factors other than thrombocytopenia likely contribute to the overall poor prognosis.

Intracranial plasma cell tumors are extremely rare and can either be solitary lesions or part of systemic multiple myeloma. We report a 42-year-old woman who presented with a posterior fossa mass and successfully underwent surgical resection, leading to the diagnosis of multiple myeloma. To our knowledge, this is the first reported case of multiple myeloma presenting as a posterior fossa mass lesion. This report highlights the importance of maintaining plasma cell tumor in the differential of intracranial mass with bony involvement. Furthermore, once the diagnosis is established, further work up is critical to evaluate for systemic disease.

The role of regulatory T cells (Tregs) in mediating immune suppression of anti-tumor immune responses is increasingly becoming appreciated in patients with malignancies - especially within the malignant glioma patient population. This review will discuss the role and prognostic significance of Tregs within glioma patients and will delineate potential approaches for their inhibition that can be used either alone or in combination with other immune therapeutics in clinical trials and in the clinical settings of recurrent and/or residual disease.

A patient with a giant symptomatic vertebrobasilar aneurysm was treated by endoscopic third ventriculostomy for obstructive hydrocephalus followed by treatment of the aneurysm by flow diversion using a Pipeline Embolization Device. After an uneventful procedure and initial periprocedural period, the patient experienced an unexpected fatal subarachnoid hemorrhage 1 week later. Autopsy demonstrated extensive subarachnoid hemorrhage and aneurysm rupture (linear whole wall rupture). The patent Pipeline Embolization Device was in its intended location, as was the persistent coil occlusion of the distal left vertebral artery. The aneurysm appeared to rupture in a linear manner and contained a thick large expansile clot that seemed to disrupt or rupture the thin aneurysm wall directly opposite the basilar artery/Pipeline Embolization Device. We feel the pattern of aneurysm rupture in our patient supports the idea that the combination of flow diversion and the resulting growing intra-aneurysmal thrombus can create a mechanical force with the potential to cause aneurysm rupture.

Introduction Following complex endovascular or microsurgical treatment of aneurysms, volumetric assessment of the surgical outcome in the angiography suite can be challenging due to device resolution and metallic artefact. We investigated a collimated volumetric imaging protocol followed by metal artefact suppression post processing to evaluate the correct positioning of stents, flow diverting devices, coils, and clips. Methods Under an IRB approved study protocol, ten patients who underwent endovascular or surgical treatment of a cerebral aneurysm involving stents, flow-diverting devices, coils, and/or clips, underwent angiography. This consisted of conventional 2D diagnostic imaging, followed by the acquisition of a volume of interest (VOI) collimated DynaCT. Such an acquisition yielded high-spatial resolution of implanted devices, by reducing the radiation burden depending on illuminated detector fraction. Volumetric images were reconstructed, accounting for the truncated images and artefact from dense metallic objects. Blinded readers were presented with VOI 3D images, processed with and without correction for metal artefact, and asked to score overall image quality, visibility of surrounding vasculature and aneurysm inflow, and diagnostic value. Scores were evaluated for statistical significance using a student’s T-test, testing the hypothesis that VOI + MAR is better than VOI alone. Results VOI images processed with metal artefact correction were judged better with 95% (p = 0.05) significance for overall image quality and 99% (p = 0.01) for the other three categories. Particular advantage was seen with the identification of residual aneurysm inflow as well as the ability to identify surrounding vasculature. Analysis of VOI scan dose area product (DAP) showed an average reduction of 85% compared to conventional DynaCT. Conclusion Combining VOI imaging with metal artefact suppression allows for clear imaging of complex aneurysm repair in the presence of dense metallic objects, while significantly reducing patient radiation exposure. Disclosures E. Duckworth: None. D. Hoit: 1; C; Seimens. L. Elijovich: 1; C; Seimens. 2; C; Microvention, Stryker, Codman. V. Doss: None. W. Humphries: None. S. Schafer: 5; C; Seimens Medical Solutions USA. S. Bauer: 5; C; Seimens Medical Solutions USA. A. Arthur: 1; C; Seimens, Terumo. 2; C; Seimens, Johnson and Johnson, Sequent Medical, Covidian, Stryker, Terumo.

Intracellular, vesicle-mediated, degradation of extracellular cargo is an essential cellular function. Of particular interest is the population of vesicles responsible for degradation of extracellular cargo. Previous work using low-density lipoprotein (LDL), a classic extracellular cargo, demonstrates that the enzyme-mediated degradation of LDL occurs in a hybrid late endosomal-lysosomal vesiclei. In addition, the degradation of LDL occurs within 60 s of the colocalization of LDL with a lysosomal protein, LAMP1. These observations suggest that lysosomes are responsible for delivering enzymes to late endosomes, forming a hybrid organelle in which degradation occurs. Using single particle tracking fluorescence microscopy, we investigate the hypothesis that lysosomes serve as enzyme storage vesicles. We test this hypothesis using two different approaches. The first approach uses cell-permeable drugs that inhibit specific enzymes known to degrade LDL; CA074ME, a cathepsin B inhibitor, and pepstatin methyl ester, a cathepsin D inhibitor. The second approach uses siRNA to knockdown expression of LAMP. Unique to these experiments is the ability to directly monitor, in intact live cells, LDL degradation utilizing a fluorescence labeling scheme that reports on the integrity of the LDL particle. This method involves conjugation of distinct fluorophores to the protein and lipid components of LDL. Upon degradation the protein reporter decreases in fluorescence intensity while the lipid reporter increases fluorescence intensity. Our experiments make it possible to describe the complete endocytic pathway of LDL from internalization to degradation and provide a more complete picture of the intracellular degradation of extracellular cargo.i W.H. Humphries IV, N.C. Fay, and C.K. Payne, Intracellular degradation of low-density lipoprotein probed with two-color fluorescence microscopy, Integrative Biology, in press, (2010).

We consider the implications of a kinetic scheme, recently proposed by Billingham and Coveney (J. Billingham and P. V. Coveney, J. Chem. Soc., Faraday Trans., 1993, 89, 3021), for the hydration of cement slurries from a molecular modelling perspective. We study a range of known phosphonate cement-setting retarders which display widely differing capabilities, and in the first part of this paper we rationalise the relative efficacies of these compounds. To do this, we deployed a range of molecular modelling techniques, including energy minimisation using semi-empirical quantum mechanical and empirical force-field calculations, for both isolated molecules and molecules interacting with appropriate surfaces of ettringite. Molecular dynamics has also been used to seek out optimal conformations of these molecules on the surfaces in question. The implications of this docking mechanism for the resulting ettringite crystal morphology are also considered.Our work provides an explanation for the relative order of effectiveness of these retarders, which is confirmed by experimental studies. We have also been able to identify a powerful phosphonate retarder on the basis of this work. Using the same modelling methods as a basis for molecular design, we propose some new phosphonate retarders which might be expected to act as effective retarders. These include novel phosphonates based on the hexaaza-18-crown-6 macrocycle. One of these exotic molecules has now been synthesised and found to display significant retardation capabilities. The synthesis of related compounds is currently in progress.

A diversion system has been designed to carry the flow from East Fork of Coal Creek around the area proposed for mining at Thunder Basin Coal Company's (TBCC) Coal Creek mine in Campbell County, Wyoming. This paper describes the field and analysis procedures necessary to prepare the diversion design and impact evaluation, and the innovative concepts developed for the diversion system design to minimize impacts on downstream channel stability. Under the proposed diversion system design, water from the East Basin of Coal Creek will be diverted at two locations. At one location, flow will be impounded by a small dam and decanted by a pump through a pipeline into East Fork at the location of the second diversion. At this location, a training dike will be placed across the stream channel to divert flows into a diversion channel. Gravity flow along the diversion channel will deliver water to a playa area which will be converted into a detention basin by placing a small dam across its southern end. Flows up to the magnitude of the 24-hour 2-year peak flow will be passed directly through the detention basin into Middle Fork with negligible attenuation of flow rates. For less frequent events,more » water will be stored in the detention basin in order to prevent velocities in Lower Middle Fork from exceeding the maximum permissible velocity above which scouring may occur. Evaporation and seepage losses from the diversion system were estimated to be small and should be more than offset by the addition of water from the playa drainage basin into the Coal Creek drainage. Velocities predicted for the Lower Middle Fork after the diversion is constructed are expected to be low enough that significant erosion of the channel is not expected to occur.« less

Twenty-six aspen (Populus tremuloides Michx.), 20 subalpine fir (Abies lasiocarps (Hook.) Nutt.), and 20 Engelmann spruce (Pices engelmanil (Parry) Engelm.) of various sizes were cut under water and suspended in permanent reserviors at a northern Utah site. The reservoirs were asealed so that all water loss was due to consumption by the trees. Sap velocities, as computed from heat pulse velocities, were related to conducting areas of the tree trunks. Computed transpiration volumes were then correlated with actual water losses from the reservoirs. Coefficients of determination (R2) of 0.87, 0.86, and 0.82 were obtained for the fir, aspen, and sprucs, respectively. Reservoir water loss for each species for each season was then used to adjust a plant activity index for computing transpiration within ASPCON, a model describing the hydrology of aspen to conifer succession. The plant activity index reflects the variation in the capability of a plant community to transpire water over the year. Assumptions and limitations of the heat pulse velocity technique are also outlined.

Heat pulse velocity techniques were developed for effective monitoring of water movement in aspen (Populus tremuloides), subalpine fir (Abies lasiocarpa), and Englemann spruce (Picea engelmannif). Water loss was monitored in replicated trees of each species for one year. These data were used to modify the plant activity index (a reflection of the ability of plants to transpire water at various times during a year) and the crop coefficient (a reflection of differences in consumptive use rates of water by different vegetation types when all other factors are held constant) for each species within the model ASPCON, a deterministic, lumped-parameter model describing the hydrology of aspen to conifer succession. Results of the modeling in dicate 18.6 cm net loss of moisture available for streamflow when spruce replaced aspen, and a loss of 7.2 cm when fir forests replaced aspen. The aspen to conifer successional trend appears, therefore, to be significantly reducing water yields in the western United States.

BackgroundThe signal transducer and activator of transcription 3 (STAT-3) is frequently overexpressed in cancer cells, propagates tumorigenesis, and is a key regulator of immune suppression in cancer patients. The presence of phosphorylated STAT-3 (p-STAT-3) in the tumor can induce p-STAT-3 in tumor-associated immune cells that can return to the circulatory system. We hypothesized that the number of peripheral blood mononuclear cells (PBMCs) displaying p-STAT-3 would be increased in glioma patients, which would correlate with the extent of tumor-expressed p-STAT-3, and that higher p-STAT-3 levels in peripheral blood would correlate with a higher fraction of immune-suppressive regulatory T cells (Tregs).MethodsWe measured the percentage of PBMCs displaying p-STAT-3 in 19 healthy donors and 45 patients with primary brain tumors. The level of p-STAT-3 in tumor tissue was determined by immunohistochemistry. The degree of immune suppression was determined based on the fraction of Tregs in the CD4 compartment.ResultsHealthy donors had 4.8 ± 3.6% of PBMCs that expressed p-STAT-3, while the mean proportion of PBMCs displaying p-STAT-3 in patients with GBM was 11.8 ± 13.5% (P= 0.03). We did not observe a correlation by Spearman correlation between the degree of p-STAT-3 levels in the tumor and the percent of PBMCs displaying p-STAT-3. Furthermore, the percent of PBMCs displaying p-STAT-3 in glioma patients was not directly correlated with the fraction of Tregs in the CD4 compartment.ConclusionWe conclude that the percent of PBMCs displaying p-STAT-3 may be increased in malignant glioma patients.