Dynamics of magnetization at infinite temperature in a Heisenberg spin chain

Understanding universal aspects of quantum dynamics is an unresolved problem in statistical mechanics. In particular, the spin dynamics of the one-dimensional Heisenberg model were conjectured as to belong to the Kardar-Parisi-Zhang (KPZ) universality class based on the scaling of the infinite-temperature spin-spin correlation function. In a chain of 46 superconducting qubits, we studied the probability distribution of the magnetization transferred across the chain's center, [Formula: see text]. The first two moments of [Formula: see text] show superdiffusive behavior, a hallmark of KPZ universality. However, the third and fourth moments ruled out the KPZ conjecture and allow for evaluating other theories. Our results highlight the importance of studying higher moments in determining dynamic universality classes and provide insights into universal behavior in quantum systems.

Stable quantum-correlated many-body states through engineered dissipation

Engineered dissipative reservoirs have the potential to steer many-body quantum systems toward correlated steady states useful for quantum simulation of high-temperature superconductivity or quantum magnetism. Using up to 49 superconducting qubits, we prepared low-energy states of the transverse-field Ising model through coupling to dissipative auxiliary qubits. In one dimension, we observed long-range quantum correlations and a ground-state fidelity of 0.86 for 18 qubits at the critical point. In two dimensions, we found mutual information that extends beyond nearest neighbors. Lastly, by coupling the system to auxiliaries emulating reservoirs with different chemical potentials, we explored transport in the quantum Heisenberg model. Our results establish engineered dissipation as a scalable alternative to unitary evolution for preparing entangled many-body states on noisy quantum processors.

PROPOSED REVISION OF THE AMERICAN ASSOCIATION FOR SURGERY OF TRAUMA RENAL TRAUMA ORGAN INJURY SCALE: SECONDARY ANALYSIS OF THE MULTI-INSTITUTIONAL GENITOURINARY TRAUMA STUDY

BACKGROUND

This study updates the American Association for Surgery of Trauma (AAST) Organ Injury Scale (OIS) for renal trauma using evidence-based criteria for bleeding control intervention.

METHODS

This was a secondary analysis of a multi-center retrospective study including patients with high grade renal trauma from 7 Level-1 trauma centers from 2013-2018. All eligible patients were assigned new renal trauma grades based on revised criteria. The primary outcome used to measure injury severity was intervention for renal bleeding. Secondary outcomes included intervention for urinary extravasation, units of packed red blood cells (PRBCs) transfused within 24 hours, and mortality. To test the revised grading system, we performed mixed effect logistic regression adjusted for multiple baseline demographic and trauma covariates. We determined the area under the receiver-operator curve (AUC) to assess accuracy of predicting bleeding interventions from the revised grading system and compared this to 2018 AAST organ injury scale.

RESULTS

based on the 2018 OIS grading system, we included 549 patients with AAST Grade III-V injuries and CT scans (III: 52% (n = 284), IV: 45% (n = 249), and V: 3% (n = 16)). Among these patients, 89% experienced blunt injury (n = 491) and 12% (n = 64) underwent intervention for bleeding. After applying the revised grading criteria, 60% (n = 329) of patients were downgraded and 4% (n = 23) were upgraded; 2.8% (n = 7) downgraded from grade V to IV, and 69.5% (n = 173) downgraded from IV to III. The revised renal trauma grading system demonstrated improved predictive ability for bleeding interventions (2018 AUC = 0.805, revised AUC = 0.883; p = 0.001) and number of units of PRBCs transfused. When we removed urinary injury from the revised system, there was no difference in its predictive ability for renal hemorrhage intervention.

CONCLUSIONS

A revised renal trauma grading system better delineates the need for hemostatic interventions than the current AAST OIS renal trauma grading system.

LEVEL OF EVIDENCE

II.

Improved chest wall trauma taxonomy: an interdisciplinary CWIS and ASER collaboration

PURPOSE

Chest wall injury taxonomy and nomenclature are important components of chest wall injury classification and can be helpful in communicating between providers for treatment planning. Despite the common nature of these injuries, there remains a lack of consensus regarding injury description. The Chest Wall Injury Society (CWIS) developed a taxonomy among surgeons in the field; however, it lacked consensus and clarity in critical areas and collaboration with multidisciplinary partners. We believe an interdisciplinary collaboration between CWIS and American Society of Emergency Radiology (ASER) will improve existing chest wall injury nomenclature and help further research on this topic.

METHODS

A collaboration between CWIS and ASER gathered feedback on the consensus recommendations. The workgroup held a series of meetings reviewing each consensus statement, refining the terminology, and contributing additional clarifications from a multidisciplinary lens.

RESULTS

After identifying incomplete definitions in the CWIS survey, the workgroup expanded on and clarified the language proposed by the survey. More precise definitions related to rib and costal cartilage fracture quality and location were developed. Proposed changes include more accurate characterization of rib fracture displacement and consistent description of costal cartilage fractures.

CONCLUSIONS

The 2019 consensus survey from CWIS provides a framework to discuss chest wall injuries, but several concepts remained unclear. Creating a universally accepted taxonomy and nomenclature, utilizing the CWIS survey and this article as a scaffolding, may help providers communicate the severity of chest wall injury accurately, allow for better operative planning, and provide a common language for researchers in the future.

Shattered Kidney After Renal Trauma: Should It Be Classified As an American Association for the Surgery of Trauma Grade V Injury?

OBJECTIVE

To study the prevalence and management of shattered kidney and to evaluate if the new description of "loss of identifiable renal anatomy" in the 2018 American Association for the Surgery of Trauma (AAST) organ injury scale (OIS) would improve the ability to predict bleeding control interventions.

METHODS

We used high-grade renal trauma data from 21 Level-1 trauma centers from 2013 to 2018. Initial CT scans were reviewed to identify shattered kidneys, defined as a kidney having ≥3 parenchymal fragments displaced by blood or fluid on cross-sectional imaging. We further categorized patients with shattered kidney in two models based on loss of identifiable renal parenchymal anatomy and presence or absence of vascular contrast extravasation (VCE). Bleeding interventions were compared between the groups.

RESULTS

From 861 high-grade renal trauma patients, 41 (4.8%) had shattered kidney injury. 25 (61%) underwent a bleeding control intervention including 18 (43.9%) nephrectomies and 11 (26.8%) angioembolizations. 18 (41%) had shattered kidney with "loss of identifiable parenchymal renal anatomy" per 2018 AAST OIS (model-1). 28 (68.3%) had concurrent VCE (model-2). Model-2 had a statistically significant improvement in area under the curve over model-1 in predicting bleeding interventions (0.75 vs 0.72; P = .01).

CONCLUSION

Shattered kidney is associated with high rates of active bleeding, urinary extravasation, and interventions including nephrectomy. The definition of shattered kidney is vague and subjective and our definition might be simpler and more reproducible. Loss of identifiable renal anatomy per the 2018 AAST OIS did not provide better distinction for bleeding control interventions over presence of VCE.

Grade V renal trauma management: results from the multi-institutional genito-urinary trauma study

PURPOSE

To investigate management trends for American Association for the Surgery of Trauma (AAST) grade V renal trauma with focus on non-operative management.

METHODS

We used prospectively collected data as part of the Multi-institutional Genito-Urinary Trauma Study (MiGUTS). We included patients with grade V renal trauma according to the AAST Injury Scoring Scale 2018 update. All cases submitted by participating centers with radiology images available were independently reviewed to confirm renal trauma grade. Management was classified as expectant, conservative (minimally invasive, endoscopic or percutaneous procedures), or operative (renal-related surgery).

RESULTS

Eighty patients were included, 25 of whom had complete imaging and had independent confirmation of AAST grade V renal trauma. Median age was 35 years (Interquartile range (IQR) 25-50) and 23 (92%) had blunt trauma. Ten patients (40%) were managed operatively with nephrectomy. Conservative management was used in nine patients (36%) of which six received angioembolization and three had a stent or drainage tube placed. Expectant management was followed in six (24%) patients. Transfusion requirements were progressively higher with groups requiring more aggressive treatment, and injury characteristics differed significantly across management groups in terms of hematoma size and laceration size. Vascular contrast extravasation was more likely in operatively managed patients though a statistically significant association was not found.

CONCLUSION

Successful use of nonoperative management for grade V injuries is used for a substantial subset of patients. Lower transfusion requirement and less severe injury radiologic phenotype appear to be important characteristics delineating this group.

Formation of robust bound states of interacting microwave photons

Systems of correlated particles appear in many fields of modern science and represent some of the most intractable computational problems in nature. The computational challenge in these systems arises when interactions become comparable to other energy scales, which makes the state of each particle depend on all other particles1. The lack of general solutions for the three-body problem and acceptable theory for strongly correlated electrons shows that our understanding of correlated systems fades when the particle number or the interaction strength increases. One of the hallmarks of interacting systems is the formation of multiparticle bound states2-9. Here we develop a high-fidelity parameterizable fSim gate and implement the periodic quantum circuit of the spin-½ XXZ model in a ring of 24 superconducting qubits. We study the propagation of these excitations and observe their bound nature for up to five photons. We devise a phase-sensitive method for constructing the few-body spectrum of the bound states and extract their pseudo-charge by introducing a synthetic flux. By introducing interactions between the ring and additional qubits, we observe an unexpected resilience of the bound states to integrability breaking. This finding goes against the idea that bound states in non-integrable systems are unstable when their energies overlap with the continuum spectrum. Our work provides experimental evidence for bound states of interacting photons and discovers their stability beyond the integrability limit.

Realizing topologically ordered states on a quantum processor

[Figure: see text].

A Piercing Diagnosis - Occult Foreign Body as the Cause of Acute Inguinal Pain

CASE PRESENTATION

A 35-year-old woman presented to the emergency department with severe right inguinal pain. Her medical history was non-contributory and there was no known trauma or injury to the region. Amid concern for an incarcerated inguinal hernia, a computed tomography was obtained revealing a linear foreign body (FB) lateral to the femoral vessels. The FB was removed without complication at bedside and found to be a beading needle likely occultly lodged three days prior.

DISCUSSION

Occult inguinal FBs are rare but can lead to deep venous thrombosis or pulmonary embolism if in or near vessels. By nature of being occult, an absence of ingestion, insertion, or penetrative history should not preclude consideration of a FB etiology. Computed tomography imaging is crucial in determining the urgency of, and approach to, inguinal foreign body removal.

External validation of a nomogram predicting risk of bleeding control interventions after high-grade renal trauma: The Multi-institutional Genito-Urinary Trauma Study

BACKGROUND

Renal trauma grading has a limited ability to distinguish patients who will need intervention after high-grade renal trauma (HGRT). A nomogram incorporating both clinical and radiologic factors has been previously developed to predict bleeding control interventions after HGRT. We aimed to externally validate this nomogram using multicenter data from level 1 trauma centers.

METHODS

We gathered data from seven level 1 trauma centers. Patients with available initial computed tomography (CT) scans were included. Each CT scan was reviewed by two radiologists blinded to the intervention data. Nomogram variables included trauma mechanism, hypotension/shock, concomitant injuries, vascular contrast extravasation (VCE), pararenal hematoma extension, and hematoma rim distance (HRD). Mixed-effect logistic regression was used to assess the associations between the predictors and bleeding intervention. The prediction accuracy of the nomogram was assessed using the area under the receiver operating characteristic curve and its 95% confidence interval (CI).

RESULTS

Overall, 569 HGRT patients were included for external validation. Injury mechanism was blunt in 89%. Using initial CT scans, 14% had VCE and median HRD was 1.7 (0.9-2.6) cm. Overall, 12% underwent bleeding control interventions including 34 angioembolizations and 24 nephrectomies. In the multivariable analysis, presence of VCE was associated with a threefold increase in the odds of bleeding interventions (odds ratio, 3.06; 95% CI, 1.44-6.50). Every centimeter increase in HRD was associated with 66% increase in odds of bleeding interventions. External validation of the model provided excellent discrimination in predicting bleeding interventions with an area under the curve of 0.88 (95% CI, 0.84-0.92).

CONCLUSION

Our results reinforce the importance of radiologic findings such as VCE and hematoma characteristics in predicting bleeding control interventions after renal trauma. The prediction accuracy of the proposed nomogram remains high using external data. These variables can help to better risk stratify high-grade renal injuries.

LEVEL OF EVIDENCE

Prognostic and epidemiological study, level III.

Clinical and Radiographic Factors Associated With Failed Renal Angioembolization: Results From the Multi-institutional Genitourinary Trauma Study (Mi-GUTS)

OBJECTIVE

To find clinical or radiographic factors that are associated with angioembolization failure after high-grade renal trauma.

MATERIAL AND METHODS

Patients were selected from the Multi-institutional Genito-Urinary Trauma Study. Included were patients who initially received renal angioembolization after high-grade renal trauma (AAST grades III-V). This cohort was dichotomized into successful or failed angioembolization. Angioembolization was considered a failure if angioembolization was followed by repeat angiography and/or an exploratory laparotomy.

RESULTS

A total of 67 patients underwent management initially with angioembolization, with failure in 18 (27%) patients. Those with failed angioembolization had a larger proportion ofgrade IV (72% vs 53%) and grade V (22% vs 12%) renal injuries. A total of 53 patients underwent renal angioembolization and had initial radiographic data for review, with failure in 13 cases. The failed renal angioembolization group had larger perirenal hematoma sizes on the initial trauma scan.

CONCLUSION

Angioembolization after high-grade renal trauma failed in 27% of patients. Failed angioembolization was associated with higher injury grade and a larger perirenal hematoma. Likely these characteristics are associated with high-grade renal trauma that may be less amenable to successful treatment after a single renal angioembolization.

CT volumetric measurements correlate with split renal function in renal trauma

PURPOSE

To evaluate whether volumetric measurements of segmental vascular injuries (SVIs) based on computed tomography (CT) imaging obtained during an initial trauma survey correlate with future nuclear medicine (NM) split renal function.

METHODS

A retrospective review was performed of renal trauma patients treated at a level 1 trauma center between 2008 and 2015. Patients with unilateral SVIs on initial CT imaging with follow-up NM renal scans were evaluated. CT-based split renal function was calculated by assessing the ratio of ipsilateral uninjured kidney volume to bilateral total uninjured kidney volume by two separate radiologists.

RESULTS

Eight patients with unilateral SVIs on initial CT trauma evaluation underwent follow-up NM renal scans at a mean of 4 months (range 2-6) after injury. Mean NM split renal function of the injured kidney was 43% (range 22-57). Based on the CT volumetric measurements of the affected kidney, mean percent injured was 23% (range 7-62) with a calculated mean split renal function of 44% (range 23-60). Calculated mean CT split function correlated with NM split function (R = 0.89). Intraclass correlation measuring inter-rater reliability for CT volumetric measurements was 0.94 (95% confidence interval 0.72-0.99).

CONCLUSION

Volumetric measurements based on CT imaging obtained during the initial trauma evaluation correlated with future NM split renal function after SVIs with high inter-rater reliability. This method utilizes pre-existing imaging and avoids additional radiation exposure, work burden, and financial cost from a NM scan. Further evaluation is required to assess feasibility with more complex injuries.

Core curriculum illustration: abdominal wood impalement injury from motor vehicle collision

This is the 42nd installment of a series that will highlight one case per publication issue from the bank of cases available online as part of the American Society of Emergency Radiology (ASER) educational resources. Our goal is to generate more interest in and use of our online materials. To view more cases online, please visit the ASER Core Curriculum and Recommendations for Study online at http://www.erad.org/page/CCIP_TOC.

Association of Radiologic Indicators of Frailty With 1-Year Mortality in Older Trauma Patients: Opportunistic Screening for Sarcopenia and Osteopenia

Importance

Assessment of physical frailty in older trauma patients admitted to the intensive care unit is often not feasible using traditional frailty assessment instruments. The use of opportunistic computed tomography (CT) scans to assess sarcopenia and osteopenia as indicators of underlying frailty may provide complementary prognostic information on long-term outcomes.

Objective

To determine whether sarcopenia and/or osteopenia are associated with 1-year mortality in an older trauma patient population.

Design, Setting, and Participants

A retrospective cohort constructed from a state trauma registry was linked to the statewide death registry and Comprehensive Hospital Abstract Reporting System for readmission data analyses. Admission abdominopelvic CT scans from patients 65 years and older admitted to the intensive care unit of a single level I trauma center between January 2011 and May 2014 were analyzed to identify patients with sarcopenia and/or osteopenia. Patients with a head Injury Severity Score of 3 or greater, an out-of-state address, or inadequate CT imaging or who died within 24 hours of admission were excluded.

Exposures

Sarcopenia and/or osteopenia, assessed via total cross-sectional muscle area and bone density at the L3 vertebral level, compared with a group with no sarcopenia or osteopenia.

Main Outcomes and Measures

One-year all-cause mortality. Secondary outcomes included 30-day all-cause mortality, 30-day readmission, hospital length of stay, hospital cost, and discharge disposition.

Results

Of the 450 patients included in the study, 269 (59.8%) were male and 394 (87.6%) were white. The cohort was split into 4 groups: 74 were retrospectively diagnosed with both sarcopenia and osteopenia, 167 with sarcopenia only, 48 with osteopenia only, and 161 with no radiologic indicators. Among the 408 who survived to discharge, sarcopenia and osteopenia were associated with higher risks of 1-year mortality alone and in combination. After adjustment, the hazard ratio was 9.4 (95% CI, 1.2-75.4; P = .03) for sarcopenia and osteopenia, 10.3 (95% CI, 1.3-78.8; P = .03) for sarcopenia, and 11.9 (95% CI, 1.3-107.4; P = .03) for osteopenia.

Conclusions and Relevance

More than half of older trauma patients in this study had sarcopenia, osteopenia, or both. Each factor was independently associated with increased 1-year mortality. Given the prevalent use of abdominopelvic CT in trauma centers, opportunistic screening for radiologic indicators of frailty provides an additional tool for early identification of older trauma patients at high risk for poor outcomes, with the potential for targeted interventions.

Multimodality approach for imaging of non-traumatic acute abdominal emergencies

"Acute abdomen" includes spectrum of medical and surgical conditions ranging from a less severe to life-threatening conditions in a patient presenting with severe abdominal pain that develops over a period of hours. Accurate and rapid diagnosis of these conditions helps in reducing related complications. Clinical assessment is often difficult due to availability of over-the-counter analgesics, leading to less specific physical findings. The key clinical decision is to determine whether surgical intervention is required. Laboratory and conventional radiographic findings are often non-specific. Thus, cross-sectional imaging plays a pivotal role for helping direct management of acute abdomen. Computed tomography is the primary imaging modality used for these cases due to fast image acquisition, although US is more specific for conditions such as acute cholecystitis. Magnetic resonance imaging or ultrasound is very helpful in patients who are particularly sensitive to radiation exposure, such as pregnant women and pediatric patients. In addition, MRI is an excellent problem-solving modality in certain conditions such as assessment for choledocholithiasis in patients with right upper quadrant pain. In this review, we discuss a multimodality approach for the usual causes of non-traumatic acute abdomen including acute appendicitis, diverticulitis, cholecystitis, and small bowel obstruction. A brief review of other relatively less frequent but important causes of acute abdomen, such as perforated viscus and bowel ischemia, is also included.

Imaging of Urinary System Trauma

Computed tomography (CT) imaging of the kidney, ureter, and bladder permit accurate and prompt diagnosis or exclusion of traumatic injuries, without the need to move the patient to the fluoroscopy suite. Real-time review of imaging permits selective delayed imaging, reducing time on the scanner and radiation dose for patients who do not require delays. Modifying imaging parameters to obtain thicker slices and noisier images permits detection of contrast extravasation from the kidneys, ureters, and bladder, while reducing radiation dose on the delayed or cystographic imaging. The American Association for the Surgery of Trauma grading system is discussed, along with challenges and limitations.

Minimal aortic injury of the thoracic aorta: imaging appearances and outcome

The aim of this study is to describe the frequency, computed tomographic angiography (CTA) imaging appearance, management, and outcome of patients who present with minimal thoracic aortic injury. This retrospective study was Institutional Review Board-approved. Eighty-one patients with blunt traumatic aortic injuries (BTAI) were identified between 2004 and 2008, comprising 23 patients with minimal aortic injury (MAI) (mean age, 43.2 years ±18.2 years; 12 males and 11 females) and 58 patients with non-minimal aortic injury (mean age, 42.6 years ±22.7 years). CTA imaging was reviewed for each patient to differentiate those with MAI from those with non-MAI BTAI. Inclusion criteria for MAI on CTA were: post-traumatic abnormality of the internal contour of the aorta wall projecting into the lumen, intimal flap, intraluminal filling defect, intramural hematoma, and no evidence of an abnormality to the external contour of the aorta. Relevant follow-up imaging for MAI patients was also reviewed for resolution, stability, or progression of the vascular injury. The electronic medical record of each patient was reviewed and mechanism of injury, injury severity score, associated injuries, type and date of management, outcome, and days from injury to last medical consultation. Minimal aortic injury represented 28.4 % of all BTAI over the study period. Mean injury severity score (37.1), age (43.2 years), and gender did not differ significantly between MAI and non-MAI types of BTAI. Most MAI occurred in the descending thoracic aorta (16/23, 69 %). Without operative or endovascular repair, there was no death or complication due to MAI. One death occurred secondary to MAI (4.4 %) in a patient who underwent endovascular repair and surgical bypass, compared with an overall mortality rate of 8.6 % in the non-MAI BTAI group (p = 0.508). The most common CT appearance of MAI was a rounded or triangular intra-luminal aortic filling detect (18/23 patients, 78 %). In a mean of 466 days of clinical follow-up, no complications were observed in survivors treated without endovascular repair or operation. Minimal aortic injury is identified by multi-detector row CT in more than a quarter of cases of BTAI and has a low mortality. Conservative management is associated with an excellent outcome.

Burst fractures of the lumbar spine in frontal crashes

BACKGROUND

In the United States, major compression and burst type fractures (>20% height loss) of the lumbar spine occur as a result of motor vehicle crashes, despite the improvements in restraint technologies. Lumbar burst fractures typically require an axial compressive load and have been known to occur during a non-horizontal crash event that involve high vertical components of loading. Recently these fracture patterns have also been observed in pure horizontal frontal crashes. This study sought to examine the contributing factors that would induce an axial compressive force to the lumbar spine in frontal motor vehicle crashes.

METHODS

We searched the National Automotive Sampling System (NASS, 1993-2011) and Crash Injury Research and Engineering Network (CIREN, 1996-2012) databases to identify all patients with major compression lumbar spine (MCLS) fractures and then specifically examined those involved in frontal crashes. National trends were assessed based on weighted NASS estimates. Using a case-control study design, NASS and CIREN cases were utilized and a conditional logistic regression was performed to assess driver and vehicle characteristics. CIREN case studies and biomechanical data were used to illustrate the kinematics and define the mechanism of injury.

RESULTS

During the study period 132 NASS cases involved major compression lumbar spine fractures for all crash directions. Nationally weighted, this accounted for 800 cases annually with 44% of these in horizontal frontal crashes. The proportion of frontal crashes resulting in MCLS fractures was 2.5 times greater in late model vehicles (since 2000) as compared to 1990s models. Belted occupants in frontal crashes had a 5 times greater odds of a MCLS fracture than those not belted, and an increase in age also greatly increased the odds. In CIREN, 19 cases were isolated as horizontal frontal crashes and 12 of these involved a major compression lumbar burst fracture primarily at L1. All were belted and almost all occurred in late model vehicles with belt pretensioners and buckets seats.

CONCLUSION

Major compression burst fractures of the lumbar spine in frontal crashes were induced via a dynamic axial force transmitted to the pelvis/buttocks into the seat cushion/pan involving belted occupants in late model vehicles with increasing age as a significant factor.

Practical considerations to setting up a radiology CME conference: how we do it

The authors describe our experience in planning, organizing, and running a radiology CME conference at a hotel (rather than at a stand-alone conference or convention center). Much of the information described should also be useful for other medical and nonmedical conferences. This experience should provide new conference organizers with useful information to ensure a more efficient and successful conference, so there are fewer "If I knew then what I know now" moments over the years.

Utility of ultrasound for evaluating the appendix during the second and third trimester of pregnancy

This study aims to retrospectively evaluate the right lower quadrant ultrasounds in women presenting during the second or third trimester of pregnancy for the frequency of appendix visualization and accuracy in diagnosing appendicitis. Institutional Review Board approval was obtained for this Health Insurance Portability and Accountability Act-compliant study. We reviewed imaging records from 99 consecutive pregnant women from 2001 to 2011 who presented during the second (≥14 weeks gestation) or third trimester for right lower quadrant ultrasound to evaluate the appendix. Visualization of the appendix as well as the size and compressibility, if identified, were recorded. The medical records and labs related to the initial patient presentation, subsequent management, and follow-up were reviewed for surgical and clinical outcomes. Pathology records were reviewed to determine if appendicitis was present when appendectomy was performed. Patients who underwent appendectomy were considered to have appendicitis based on pathology results, and patients managed non-operatively with symptom improvement and those with a normal appendix at pathology were considered to not have appendicitis. During the study period, 99 women meeting inclusion criteria presented to our institution for right lower quadrant ultrasound to evaluate the appendix during the second or third trimester of pregnancy. The mean gestational age at presentation was 23 weeks (±7 weeks). The mean maternal age was 28 years (±6.6 years). The appendix was not visualized in 97% (96/99) of right lower quadrant ultrasound examinations. Of the three studies in which the appendix was visualized, two were considered positive for appendicitis and one was considered negative. Eight patients in this group ultimately underwent appendectomy, including the two patients with positive right lower quadrant ultrasounds, and appendicitis confirmed at pathology in seven of these cases (87.5%). Right lower quadrant ultrasound successfully demonstrated an abnormal appendix in 28.7% (two of seven) of surgically confirmed cases; however, this technique did not detect appendicitis in 71% (five of seven) of patients with surgically proven disease due to nonvisualization of the appendix. Retrospective review of right lower quadrant ultrasounds performed during the second and third trimester of pregnancy suggests that this modality has limited utility for diagnosing appendicitis due to infrequent visualization of the appendix.

Identifying survivors with traumatic craniocervical dissociation: a retrospective study

BACKGROUND

Traumatic craniocervical dissociation (CCD), which includes atlanto-occipital dissociation and vertical distraction between C1-C2, is often an immediately fatal injury that has increasingly been associated with survival to the hospital. Our aim was to identify survivors of CCD based on clinical presentation.

METHODS

We retrospectively reviewed the Harborview Medical Center Trauma Registry and the King County Medical Examiners database from 2001 to 2006. Patients>or=12 y old were identified by ICD-9 code, radiographic diagnosis on lateral cervical spine films, and CT. We examined age, gender, mechanism of injury, presentation and prehospital and hospital interventions, and radiographic findings to distinguish survivors and non-survivors.

RESULTS

Of 69 patients with CCD, 47 were diagnosed post mortem, 22 were diagnosed in hospital, and seven survived to discharge. When comparing survivors and non-survivors, age, gender, and injury severity score were not significant. Survivors had significantly higher GCS, and were more likely to be normotensive; none had cervical cord injury; 80% of non-survivors had a basion-dental interval (BDI) of >or=16mm.

CONCLUSIONS

Trauma patients diagnosed with CCD in the ED, with cervical cord injury, requiring CPR, and with GCS of 3 will not survive their injury. Wider BDI is associated with mortality.

TACI-Ig prevents the development of airway hyperresponsiveness in a murine model of asthma

BACKGROUND

Increased levels of serum IgE are associated with greater asthma prevalence and disease severity. IgE depletion using an anti-IgE monoclonal antibody has met with success in the treatment of moderate-to-severe and severe persistent allergic asthma.

OBJECTIVE

To test whether B cell-targeted therapy is a more effective treatment for airway hyperresponsiveness (AHR) in a murine model compared with IgE-depletion.

METHODS

We delivered soluble mTACI-Ig, a receptor for the B cell survival factors BLyS (B Lymphocyte Stimulator) and APRIL (A PRoliferation-Inducing Ligand), or anti-IgE to allergen-sensitized mice before airway challenge with allergen.

RESULTS

mTACI-Ig treatment reduced circulating mature B cell levels in the blood, while anti-IgE treatment had no effect on B cell counts. Both mTACI-Ig and anti-IgE decreased the levels of total and allergen-specific IgE in the serum. Histopathologic analysis of lungs showed a reduction in disease severity scores for both treatment groups, but results were more pronounced in mTACI-Ig-treated mice. Neutrophil and eosinophil numbers in the bronchoalveolar lavage (BAL) were significantly reduced following mTACI-Ig treatment, but not after anti-IgE delivery. BLyS and APRIL blockade also resulted in a significant decrease in IL-4 and eotaxin mRNA and IL-4 and KC protein levels in total lung homogenates and BAL fluid, respectively. Finally, mTACI-Ig treatment was more effective than anti-IgE treatment in reducing AHR to inhaled antigen.

CONCLUSIONS

Our data demonstrate that delivery of mTACI-Ig is a more effective treatment than anti-IgE mAb in a murine model of AHR.

The evolution of the diagnostic work-up for stab wounds to the back and flank

BACKGROUND

Stab wounds to the back and flank infrequently cause injuries requiring operative treatment. Triple-contrast CT scan (3CT) has essentially replaced diagnostic peritoneal lavage (DPL) as the primary means of identifying patients who require operative intervention. This study aims to review the evolution of the diagnostic work-up for stab wounds to the back and flank.

METHODS

We performed a retrospective review of haemodynamically stable patients with stab wound to the back or flank treated at a single Level 1 trauma centre over a 10-year period. Diagnostic accuracy of DPL and 3CT screening tests were evaluated against the patient's subsequent clinical course. The elapsed time between emergency department (ED) presentation and test results was recorded and compared.

RESULTS

A total of 177 patients were identified. 76 patients had stab wounds isolated to the back, 90 had stab wounds isolated to the flank and 11 had wounds in both locations. CT ultimately became the predominant initial diagnostic test during the study period. Although less frequently used over time, DPL retained good sensitivity and specificity for injuries requiring operative intervention (92% and 83%, respectively). 3CT identified all injuries requiring laparotomy (100% sensitivity) and had a specificity of 96%. 3CT was a more time-consuming process, with results available at a median of 3:31h after arrival to the ED, as compared to 1:03h for DPL (p<0.01).

CONCLUSIONS

3CT diagnosed all injuries requiring operative intervention, and its use was associated with a lower rate of non-therapeutic laparotomies. However, average time to diagnosis by 3CT was prolonged compared to DPL. Although 3CT has become the predominant diagnostic test when evaluating patients with stab wounds to the back and flank at our institution, efforts to further expedite the diagnostic work-up are necessary.

Imaging of high-energy midfacial trauma: what the surgeon needs to know

Treatment goals in severe midfacial trauma are restoration of function and appearance. Restoration of function is directed at multiple organ systems, which support visual acuity, airway patency, mastication, lacrimation, smelling, tasting, hearing, and facial expression. Victims of blunt facial trauma expect to look the same after surgical treatment as before injury. Delicate soft tissues of the midface often make cosmetic reconstructive surgery technically challenging. Generally, clinical evaluation alone does not suffice to fully characterize facial fractures associated with extensive swelling, and the deeper midface is not accessible to physical examination. Properly performed computed tomography (CT) overcomes most limitations of presurgical examination. Thus, operative approaches and sequencing of surgical repair are guided by imaging information displayed by CT. Restoration of function and appearance relies on recreating normal maxillofacial skeletal anatomy, with particular attention to position of the malar eminences, mandibular condyles, vertical dimension and orbital morphology. Due to its pivotal role in surgical planning, CT scans obtained for the evaluation of severe midfacial trauma should be designed to easily depict the imaging information necessary for clinical decision making.

LEARNING OBJECTIVES

1. Understand the facial skeletal buttress system; 2. Understand how the pattern of derangement of the buttress system determines the need for and choice of operative approach for repair of fractures in the middle third of the face; 3. Understand the role and importance of CT and CT reformations in the detection and classification of the pattern of buttress system derangement.

TACI-Ig neutralizes molecules critical for B cell development and autoimmune disease. impaired B cell maturation in mice lacking BLyS

BLyS and APRIL have similar but distinct biological roles, mediated through two known TNF receptor family members, TACI and BCMA. We show that mice treated with TACI-Ig and TACI-Ig transgenic mice have fewer transitional T2 and mature B cells and reduced levels of circulating immunoglobulin. TACI-Ig treatment inhibits both the production of collagen-specific Abs and the progression of disease in a mouse model of rheumatoid arthritis. In BLyS-deficient mice, B cell development is blocked at the transitional T1 stage such that virtually no mature B cells are present, while B-1 cell numbers are relatively normal. These findings further elucidate the roles of BLyS and APRIL in modulating B cell development and suggest that BLyS is required for the development of most but not all mature B cell populations found in the periphery.

Interleukin 21 and its receptor are involved in NK cell expansion and regulation of lymphocyte function

Cytokines are important in the regulation of haematopoiesis and immune responses, and can influence lymphocyte development. Here we have identified a class I cytokine receptor that is selectively expressed in lymphoid tissues and is capable of signal transduction. The full-length receptor was expressed in BaF3 cells, which created a functional assay for ligand detection and cloning. Conditioned media from activated human CD3+ T cells supported proliferation of the assay cell line. We constructed a complementary DNA expression library from activated human CD3+ T cells, and identified a cytokine with a four-helix-bundle structure using functional cloning. This cytokine is most closely related to IL2 and IL15, and has been designated IL21 with the receptor designated IL21 R. In vitro assays suggest that IL21 has a role in the proliferation and maturation of natural killer (NK) cell populations from bone marrow, in the proliferation of mature B-cell populations co-stimulated with anti-CD40, and in the proliferation of T cells co-stimulated with anti-CD3.

Rhizobium etli CE3 carries vir gene homologs on a self-transmissible plasmid

RosR is a transcriptional regulator important for determining cell-surface characteristics and nodulation competitiveness in Rhizobium etli CE3. We identified a 15-kb region that contains genes with similarity to members of the virB, virC, virG, and virE operons of Agrobacterium tumefaciens and demonstrated that RosR directly regulates one operon in this region. These genes were located on plasmid pa of R. etli CE3, which is self-transmissible between R. etli and A. tumefaciens.

TACI and BCMA are receptors for a TNF homologue implicated in B-cell autoimmune disease

B cells are important in the development of autoimmune disorders by mechanisms involving dysregulated polyclonal B-cell activation, production of pathogenic antibodies, and co-stimulation of autoreactive T cells. zTNF4 (BLyS, BAFF, TALL-1, THANK) is a member of the tumour necrosis factor (TNF) ligand family that is a potent co-activator of B cells in vitro and in vivo. Here we identify two receptors for zTNF4 and demonstrate a relationship between zTNF4 and autoimmune disease. Transgenic animals overexpressing zTNF4 in lymphoid cells develop symptoms characteristic of systemic lupus erythaematosus (SLE) and expand a rare population of splenic B-Ia lymphocytes. In addition, circulating zTNF4 is more abundant in NZBWF1 and MRL-lpr/lpr mice during the onset and progression of SLE. We have identified two TNF receptor family members, TACI and BCMA, that bind zTNF4. Treatment of NZBWF1 mice with soluble TACI-Ig fusion protein inhibits the development of proteinuria and prolongs survival of the animals. These findings demonstrate the involvement of zTNF4 and its receptors in the development of SLE and identify TACI-Ig as a promising treatment of autoimmune disease in humans.

Paraplegia due to ossification of ligamenta flava in X-linked hypophosphatemia. A case report

STUDY DESIGN

Spinal canal decompression at the most prominent of multiple posterior calcified thoracic lesions in a case of X-linked hypophosphatemia was undertaken for treatment and diagnosis purposes, as well as to assess possible nature of the pathophysiology underlying the presenting deficits.

OBJECTIVES

To discuss the clinical assessment diagnostic and treatment aspects of this rare coincidence of ossification of ligamenta flava in the patient with the skeletal deformities of X-linked hypophosphatemia.

SUMMARY OF BACKGROUND DATA

The patient with the stigmata and chemical findings of an X-linked hypophosphatemia presented with paraplegia and multiple calcified posterior spinal thoracic lesions. This was studied with magnetic resonance imaging and electrophysiologic studies of the spinal sensory pathways of the legs. These data constituted the preoperative information required to assess later results of surgical intervention.

METHODS

Presurgical clinical, imaging and electrophysiologic studies and laboratory and pathologic investigations of the surgical specimens.

RESULTS

Resolution of the paraplegia with walking and return to work in a physically demanding job for the last 4 or 5 years of postoperative follow-up after surgical decompression of the spinal cord only at the worst and highest of the effected spinal levels.

CONCLUSION

The coincidence of X-linked hypophosphatemia and ossification of ligamenta flava has been reported only in two or three cases in the literature. Removal of the offending ossifying lesion is known to result in resolution of the clinical deficits but similar lesions at other spinal levels are suspected of producing recurrences. The return of function and of the corresponding electrophysiologic correlates indicate a neurono-apractic nature of the neurologic symptoms.