XJL - an XML schema for the rapid development of advanced synthetic environments

Virtual reality is a tremendous tool and a powerful catalyst of modern scientific and design achievements. These achievements, however, require users to exhibit a highly technical background beyond their area of expertise. With the consideration that large-scale immersive visualization systems require detailed knowledge of the hardware and software that render and maintain their imagery, we recognize that these systems are not easily usable by non-computer experts. The research presented in this document discusses the design and implementation of an interpreted language for the rapid development of immersive applications. The design is based on a specialized XML schema and the intended end users are digital artists and designers. Our goal is to remove the complexity of writing and compiling traditional code and provide the artist a more usable method of developing a full-featured application. Our design has been built upon VR Juggler; an open source development environment focused on abstracting applications from the hardware and devices used in their run time execution. Upon this foundation we have created an interface through which the user may define object animation, navigation algorithms, object transformations, and environmental settings. This interface reduces the programming requirements of advanced virtual worlds development, such that a significant number of digital artists, previously held at bay, will have the means to produce powerful and creative environments

Imaging of vascular remodeling after simulated thoracoabdominal aneurysm repair

ObjectiveA better understanding of the response of the spinal cord blood supply to segmental artery (SA) sacrifice should help minimize the risk of paraplegia after both open and endovascular repair of thoracoabdominal aortic (TAA) aneurysms.MethodsTwelve female juvenile Yorkshire pigs were randomized into 3 groups and perfused with a barium–latex solution. Pigs in group 1 (control) had infusion without previous intervention. Pigs in group 2 were infused 48 hours after ligation of all SAs (T4-L5) and those in group 3 at 120 hours after ligation. Postmortem computed tomographic scanning of the entire pig enabled overall comparisons and measurement of vessel diameters in the spinal cord circulation.ResultsWe ligated 14.5 ± 0.8 SAs: all filled retrograde to the ligature. Paraplegia occurred in 38% of operated pigs. A significant increase in the mean diameter of the anterior spinal artery (ASA) was evident after SA sacrifice (P < .0001 for 48 hours and 120 hours). The internal thoracic and intercostal arteries also increased in diameter. Quantitative assessment showed an increase in vessel density 48 hours after ligation of SAs, reflected by an obvious increase in small collateral vessels seen on 3-dimensional reconstructions of computed tomographic scans at 120 hours.ConclusionsRemodeling of the spinal cord blood supply—including dilatation of the ASA and proliferation of small collateral vessels—is evident at 48 and 120 hours after extensive SA sacrifice. It is likely that exploitation of this process will prove valuable in the quest to eliminate paraplegia after TAA aneurysm repair

A Rare Case of HIV-Induced Inflammatory Demyelinating Polyneuropathy.

Background:Acute inflammatory demyelinating polyneuropathy (AIDP) is an uncommon form of neuropathy in HIV-infected patients that can cause pain, sensory disturbance, and motor weakness. Case presentation:A 23-year-old African American male with past medical history of Guillain-Barre Syndrome (GBS), Lyme disease, and sexually transmitted infections including syphilis and chlamydia presented with acute back pain radiating to bilateral lower extremities with worsening right foot weakness for four days. Cerebrospinal fluid (CSF) studies including meningoencephalitis panel were negative as well as blood tests for Lyme disease and HIV antibody testing. Patient was initially treated with penicillin for positive treponemal serology but without improvement in lower extremity weakness. Electromyogram showed evidence of early demyelinating motor polyneuropathy. Four days after presentation, repeat HIV antibody testing returned positive. Recurrent AIDP in this case was suspected to be secondary to acute HIV infection, and highly active antiretroviral therapy (HAART) was administered along with intravenous immunoglobulin (IVIG). Muscle strength improved with therapy and patient was expected to have continued improvement with intensive rehabilitation after discharge. Conclusion:Acute inflammatory demyelinating polyneuropathy (AIDP) tends to present early in course of HIV infection. Therefore, HIV testing should be obtained in individuals presenting with new neurological deficits. Our patient received HAART therapy, in addition to the traditional modalities to manage AIDP, which led to a substantial recovery of his sensorimotor function

The collateral network concept: Remodeling of the arterial collateral network after experimental segmental artery sacrifice

ObjectiveA comprehensive strategy to prevent paraplegia after open surgical or endovascular repair of thoracoabdominal aortic aneurysms requires a thorough understanding of the response of the collateral network to extensive segmental artery sacrifice.MethodsTen Yorkshire pigs underwent perfusion with a low-viscosity acrylic resin. With the use of cardiopulmonary bypass, 2 animals each were perfused in the native state and immediately, 6 hours, 24 hours, and 5 days after sacrifice of all segmental arteries (T4–L5). After digestion of surrounding tissue, the vascular cast of the collateral network underwent analysis of arterial and arteriolar diameters and the density and spatial orientation of the vasculature using light and scanning electron microscopy.ResultsWithin 24 hours, the diameter of the anterior spinal artery had increased significantly, and within 5 days the anterior spinal artery and the epidural arterial network had enlarged in diameter by 80% to 100% (P < .0001). By 5 days, the density of the intramuscular paraspinous vessels had increased (P < .0001), a shift of size distribution from small to larger arterioles was seen (P = .0002), and a significant realignment of arterioles parallel to the spinal cord had occurred (P = .0005).ConclusionsWithin 5 days after segmental artery occlusion, profound anatomic alterations in the intraspinal and paraspinous arteries and arterioles occurred, providing the anatomic substrate for preservation of spinal cord blood flow via collateral pathways

Comparison of the Long-Term Effect of Positioning the Cathode in tDCS in Tinnitus Patients

Objective: Transcranial direct current stimulation (tDCS) is one of the methods described in the literature to decrease the perceived loudness and distress caused by tinnitus. However, the main effect is not clear and the number of responders to the treatment is variable. The objective of the present study was to investigate the effect of the placement of the cathode on the outcome measurements. Methods: Patients considered for the trial were chronic non-pulsatile tinnitus patients with complaints for more than 3 months and a Tinnitus Functional Index (TFI) score that exceeded 25. The anode was placed on the right dorsolateral prefrontal cortex (DLPFC). In the first group—“bifrontal”—the cathode was placed on the left DLPFC, while in the second group—“shoulder”—the cathode was placed on the shoulder. Each patient received two sessions of tDCS weekly and eight sessions in total. Evaluations took place on the first visit for an ENT consultation, at the start of therapy, after eight sessions of tDCS and at the follow-up visit, which took place 84 days after the start of the therapy. Subjective outcome measures such as TFI, Visual Analog Scales (VAS) for loudness and percentage of consciousness of tinnitus were administered in every patient. Results: There was no difference in the results for tinnitus loudness and the distress experienced between the placement of the cathode on the left DLPFC or on the shoulder. In addition, no statistically significant overall effect was found between the four test points. However, up to 39.1% of the patients experienced a decrease in loudness, measured by the VAS for loudness. Moreover, 72% of those in the bifrontal group, but only 46.2% of those in the shoulder group reported some improvement in distress. Conclusion: While some improvement was noted, this was not statistically significant. Both electrode placements stimulated the right side of the hippocampus, which could be responsible for the effect found in both groups. Further research should rule out the placebo effect and investigate alternative electrode positions

The fate of the distal aorta after repair of acute type A aortic dissection

ObjectivesThe residual aorta’s behavior after repair of acute type A dissection is incompletely understood. We analyzed segmental growth rates, distal reoperation, and factors influencing long-term survival.MethodsOne hundred seventy-nine consecutive patients (70% male; mean age, 60 years) with acute type A dissection underwent aggressive resection of the intimal tear and open distal anastomosis (1986-2003). Hospital mortality was 13.4%. Survivors had serial computed tomographic scans: digitization yielded distal segmental dimensions. Segment-specific average rates of enlargement and factors influencing faster growth were analyzed. Distal reoperations and patient survival were examined.ResultsEighty-nine (57%) patients had imaging data sufficient for growth rate calculations. The median diameters after repair were as follows: aortic arch, 3.6 cm; descending aorta, 3.7 cm; and abdominal aorta, 3.2 cm. Subsequent growth rates were 0.8, 1.0, and 0.8 mm/y, respectively. Initial size of greater than 4 cm (P = .005) and initial diameter of less than 4 cm with a patent false lumen (P = .004) predicted greater growth in the descending aorta, and male sex (P = .05) significantly affected growth in the abdominal aorta. No significant factors were found for the aortic arch. There were 25 distal aortic reoperations (16 patients), and risk of reoperation was 16% at 10 years. Risk factors reducing long-term survival after repair of acute type A dissection included age (P < .0001), new neurological deficit at presentation (P = .04), absence of preoperative thrombus in the false lumen of the ascending aorta (P = .03), and a patent distal false lumen postoperatively (P = .06) but not distal reoperation.ConclusionsGrowth of the distal aorta after repair of acute type A dissection is typically slow and linear. Distal reoperation is uncommon, and late risk of death is approximately twice that of a healthy population

Endovascular treatment of thoracoabdominal aortic aneurysm: a case report

<p>Abstract</p> <p>Introduction</p> <p>Thoracoabdominal aortic aneurysms usually present in elderly patients with serious renal, pulmonary, cerebral, or cardiac comorbidities that pose a great challenge to the attending surgeon. Endovascular techniques for the treatment of thoracoabdominal aneurysms are not yet widely used due to limitations associated with them, such as spinal and visceral ischemia.</p> <p>Case presentation</p> <p>An 87-year-old Caucasian man with a symptomatic Crawford type I thoracoabdominal aortic aneurysm was treated successfully with a long tube stent graft using endovascular techniques and without any complication in follow-up examinations. The stent was placed distal to the left subclavian artery, and proximal to the celiac axis.</p> <p>Conclusion</p> <p>The use of endovascular stents for long segment thoracoabdominal aortic aneurysms needs to undergo clinical investigation to determine whether this procedure decreases morbidity and mortality rates.</p

Assessing copy number abnormalities and copy-neutral loss-of-heterozygosity across the genome as best practice in diagnostic evaluation of acute myeloid leukemia: An evidence-based review from the cancer genomics consortium (CGC) myeloid neoplasms working group

Structural genomic abnormalities, including balanced chromosomal rearrangements, copy number gains and losses and copy-neutral loss-of-heterozygosity (CN-LOH) represent an important category of diagnostic, prognostic and therapeutic markers in acute myeloid leukemia (AML). Genome-wide evaluation for copy number abnormalities (CNAs) is at present performed by karyotype analysis which has low resolution and is unobtainable in a subset of cases. Furthermore, examination for possible CN-LOH in leukemia cells is at present not routinely performed in the clinical setting. Chromosomal microarray (CMA) analysis is a widely available assay for CNAs and CN-LOH in diagnostic laboratories, but there are currently no guidelines how to best incorporate this technology into clinical testing algorithms for neoplastic diseases including AML. The Cancer Genomics Consortium Working Group for Myeloid Neoplasms performed an extensive review of peer-reviewed publications focused on CMA analysis in AML. Here we summarize evidence regarding clinical utility of CMA analysis in AML extracted from published data, and provide recommendations for optimal utilization of CMA testing in the diagnostic workup. In addition, we provide a list of CNAs and CN-LOH regions which have documented clinical significance in diagnosis, prognosis and treatment decisions in AML

Reoperative aortic root and transverse arch procedures: A comparison with contemporaneous primary operations

ObjectivesLong-term survival and risk factors affecting outcome after reoperative root/ascending aorta and transverse arch procedures have not been clearly described.MethodsTwo hundred patients (138 male patients; age, 60 ± 15 years) underwent reoperative root/ascending aorta (n = 100) or transverse arch (n = 100) procedures at our institution from January 1998 to December 2004 and were compared with 480 consecutive contemporaneous patients with primary procedures (323 male patients; age, 62 ± 16 years; 335 proximal aorta and 145 transverse arch procedures).ResultsReoperative proximal aorta procedures had a higher hospital mortality (7%) than primary root/ascending aorta procedures (3%), but there was a less dramatic difference in operative mortality after primary and reoperative arch procedures (9% vs 10%). Separate multivariable analyses of root/ascending aorta procedures and arch procedures revealed chronic obstructive pulmonary disease and age to be significant risk factors for death after either procedure. In addition, an ejection fraction of less than 30% posed a significant risk for proximal aortic surgery, and diabetes and nonelective operations predicted poorer outcome after arch operations. For survivors of root/ascending aorta operations, there was no significant difference in long-term outcome between reoperations and primary procedures, with both restoring longevity to expected levels for an age- and sex-matched normal population. Patients undergoing arch operations, however, continued to have a poorer long-term outlook than their normal peers.ConclusionsIn this series, reoperations in the transverse arch carry the same risk as primary arch procedures, but a higher operative mortality is seen with reoperative than with primary root/ascending aorta procedures. The long-term outlook is better for patients undergoing root/ascending operations than for patients undergoing aortic arch operations, with no difference in the longevity of patients undergoing primary procedures versus reoperations