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Sample records for aaa rupture risk

  1. Biomechanical Rupture Risk Assessment

    PubMed Central

    2016-01-01

    Abdominal aortic aneurysm (AAA) rupture is a local event in the aneurysm wall that naturally demands tools to assess the risk for local wall rupture. Consequently, global parameters like the maximum diameter and its expansion over time can only give very rough risk indications; therefore, they frequently fail to predict individual risk for AAA rupture. In contrast, the Biomechanical Rupture Risk Assessment (BRRA) method investigates the wall’s risk for local rupture by quantitatively integrating many known AAA rupture risk factors like female sex, large relative expansion, intraluminal thrombus-related wall weakening, and high blood pressure. The BRRA method is almost 20 years old and has progressed considerably in recent years, it can now potentially enrich the diameter indication for AAA repair. The present paper reviews the current state of the BRRA method by summarizing its key underlying concepts (i.e., geometry modeling, biomechanical simulation, and result interpretation). Specifically, the validity of the underlying model assumptions is critically disused in relation to the intended simulation objective (i.e., a clinical AAA rupture risk assessment). Next, reported clinical BRRA validation studies are summarized, and their clinical relevance is reviewed. The BRRA method is a generic, biomechanics-based approach that provides several interfaces to incorporate information from different research disciplines. As an example, the final section of this review suggests integrating growth aspects to (potentially) further improve BRRA sensitivity and specificity. Despite the fact that no prospective validation studies are reported, a significant and still growing body of validation evidence suggests integrating the BRRA method into the clinical decision-making process (i.e., enriching diameter-based decision-making in AAA patient treatment).

  2. Biomechanical rupture risk assessment of abdominal aortic aneurysms based on a novel probabilistic rupture risk index.

    PubMed

    Polzer, Stanislav; Gasser, T Christian

    2015-12-01

    A rupture risk assessment is critical to the clinical treatment of abdominal aortic aneurysm (AAA) patients. The biomechanical AAA rupture risk assessment quantitatively integrates many known AAA rupture risk factors but the variability of risk predictions due to model input uncertainties remains a challenging limitation. This study derives a probabilistic rupture risk index (PRRI). Specifically, the uncertainties in AAA wall thickness and wall strength were considered, and wall stress was predicted with a state-of-the-art deterministic biomechanical model. The discriminative power of PRRI was tested in a diameter-matched cohort of ruptured (n = 7) and intact (n = 7) AAAs and compared to alternative risk assessment methods. Computed PRRI at 1.5 mean arterial pressure was significantly (p = 0.041) higher in ruptured AAAs (20.21(s.d. 14.15%)) than in intact AAAs (3.71(s.d. 5.77)%). PRRI showed a high sensitivity and specificity (discriminative power of 0.837) to discriminate between ruptured and intact AAA cases. The underlying statistical representation of stochastic data of wall thickness, wall strength and peak wall stress had only negligible effects on PRRI computations. Uncertainties in AAA wall stress predictions, the wide range of reported wall strength and the stochastic nature of failure motivate a probabilistic rupture risk assessment. Advanced AAA biomechanical modelling paired with a probabilistic rupture index definition as known from engineering risk assessment seems to be superior to a purely deterministic approach. PMID:26631334

  3. Relative importance of aneurysm diameter and body size for predicting AAA rupture in men and women

    PubMed Central

    Lo, Ruby C.; Lu, Bing; Fokkema, Margriet T.M.; Conrad, Mark; Patel, Virendra I.; Fillinger, Mark; Matyal, Robina; Schermerhorn, Marc L.

    2014-01-01

    Objectives Women have been shown to have up to a four-fold higher risk of abdominal aortic aneurysm (AAA) rupture at any given aneurysm diameter compared to men, leading to recommendations to offer repair to women at lower diameter thresholds. Although this higher risk of rupture may simply reflect greater relative aortic dilatation in women who have smaller aortas to begin with, this has never been quantified. Our objective was therefore to quantify the relationship between rupture and aneurysm diameter relative to body size and to determine whether a differential association between aneurysm diameter, body size, and rupture risk exists for men and women. Methods We performed a retrospective review of all patients in the Vascular Study Group of New England (VSGNE) database who underwent endovascular or open AAA repair. Using each patient’s height and weight, body mass index (BMI) and body surface area (BSA) were calculated. Next, indices of each measure of body size (height, weight, BMI, BSA) relative to aneurysm diameter were calculated for each patient. To generate these indices, we divided aneurysm diameter (in cm) by the measure of body size [e.g. aortic size index (ASI) = aneurysm diameter (cm) / BSA (m2)]. Along with other relevant clinical variables, we used these indices to construct different age-adjusted and multivariable-adjusted logistic regression models to determine predictors of ruptured repair vs. elective repair. Models for men and women were developed separately and different models were compared using the area under the curve (AUC). Results We identified 4045 patients who underwent AAA repair (78% male, 53% EVAR). Women had significantly smaller diameter aneurysms, lower BSA, and higher BSA indices than men (Table 1). For men, the variable that increased the odds of rupture the most was aneurysm diameter (AUC = 0.82). Men exhibited an increased rupture risk with increasing aneurysm diameter (<5.5cm: OR 1.0; 5.5–6.4cm: OR 0.9, 95% CI 0.5–1

  4. Geometrical factors as predictors of increased growth rate or increased rupture risk in small aortic aneurysms.

    PubMed

    Georgakarakos, Efstratios; Ioannou, Christos V

    2012-07-01

    Abdominal Aortic Aneurysms (AAAs) are focal dilation of the aorta that can lead to excessive enlargement and rupture over time. Current practice suggests intervention when the maximum diameter exceeds 5.5 cm, since in this diameter range the annual rupture risk outweighs the operative mortality. However, small AAA (<5.5 cm), though infrequently, may rupture or produce symptoms. Evidence from large randomized studies of small AAAs support the heterogeneity in patterns of growth and rupture potential among small AAAs. Elevated wall stress values have been implicated in AAAs rupture and rapid enlargement. Additionally, many studies have identified a strong correlation between certain geometric factors and elevated stress values. In this article we discuss the possibility that geometrical factors may have a predictive value to identify those small AAAs that have an increased risk of rupture or growth rate either during initial examination or during follow-up, making them amenable for early repair. PMID:22541859

  5. Analysis and computer program for rupture-risk prediction of abdominal aortic aneurysms

    PubMed Central

    Kleinstreuer, Clement; Li, Zhonghua

    2006-01-01

    Background Ruptured abdominal aortic aneurysms (AAAs) are the 13th leading cause of death in the United States. While AAA rupture may occur without significant warning, its risk assessment is generally based on critical values of the maximum AAA diameter (>5 cm) and AAA-growth rate (>0.5 cm/year). These criteria may be insufficient for reliable AAA-rupture risk assessment especially when predicting possible rupture of smaller AAAs. Methods Based on clinical evidence, eight biomechanical factors with associated weighting coefficients were determined and summed up in terms of a dimensionless, time-dependent severity parameter, SP(t). The most important factor is the maximum wall stress for which a semi-empirical correlation has been developed. Results The patient-specific SP(t) indicates the risk level of AAA rupture and provides a threshold value when surgical intervention becomes necessary. The severity parameter was validated with four clinical cases and its application is demonstrated for two AAA cases. Conclusion As part of computational AAA-risk assessment and medical management, a patient-specific severity parameter 0 < SP(t) < 1.0 has been developed. The time-dependent, normalized SP(t) depends on eight biomechanical factors, to be obtained via a patient's pressure and AAA-geometry measurements. The resulting program is an easy-to-use tool which allows medical practitioners to make scientific diagnoses, which may save lives and should lead to an improved quality of life. PMID:16529648

  6. The Role of Geometric and Biomechanical Factors in Abdominal Aortic Aneurysm Rupture Risk Assessment

    PubMed Central

    Raut, Samarth S.; Chandra, Santanu; Shum, Judy; Finol, Ender A.

    2013-01-01

    The current clinical management of abdominal aortic aneurysm (AAA) disease is based to a great extent on measuring the aneurysm maximum diameter to decide when timely intervention is required. Decades of clinical evidence show that aneurysm diameter is positively associated with the risk of rupture, but other parameters may also play a role in causing or predisposing the AAA to rupture. Geometric factors such as vessel tortuosity, intraluminal thrombus volume, and wall surface area are implicated in the differentiation of ruptured and unruptured AAAs. Biomechanical factors identified by means of computational modeling techniques, such as peak wall stress, have been positively correlated with rupture risk with a higher accuracy and sensitivity than maximum diameter alone. The objective of this review is to examine these factors, which are found to influence AAA disease progression, clinical management and rupture potential, as well as to highlight on-going research by our group in aneurysm modeling and rupture risk assessment. PMID:23508633

  7. Computational evaluation of aortic aneurysm rupture risk: what have we learned so far?

    PubMed

    Georgakarakos, Efstratios; Ioannou, Christos V; Papaharilaou, Yannis; Kostas, Theodoros; Katsamouris, Asterios N

    2011-04-01

    In current clinical practice, aneurysm diameter is one of the primary criteria used to decide when to treat a patient with an abdominal aortic aneurysm (AAA). It has been shown that simple association of aneurysm diameter with the probability of rupture is not sufficient, and other parameters may also play a role in causing or predisposing to AAA rupture. Peak wall stress (PWS), intraluminal thrombus (ILT), and AAA wall mechanics are the factors most implicated with rupture risk and have been studied by computational risk evaluation techniques. The objective of this review is to examine these factors that have been found to influence AAA rupture. The prediction rate of rupture among computational models depends on the level of model complexity and the predictive value of the biomechanical parameters used to assess risk, such as PWS, distribution of ILT, wall strength, and the site of rupture. There is a need for simpler geometric analogues, including geometric parameters (e.g., lumen tortuosity and neck length and angulation) that correlate well with PWS, conjugated with clinical risk factors for constructing rupture risk predictive models. Such models should be supported by novel imaging techniques to provide the required patient-specific data and validated through large, prospective clinical trials. PMID:21521062

  8. Identifying risk factors for uterine rupture.

    PubMed

    Smith, Jennifer G; Mertz, Heather L; Merrill, David C

    2008-03-01

    Uterine rupture, whether in the setting of a prior uterine incision or in an unscarred uterus, is an obstetric emergency with potentially catastrophic consequences for both mother and child. Numerous studies have been published regarding various risk factors associated with uterine rupture. Despite the mounting data regarding both antepartum and intrapartum factors, it currently is impossible to predict in whom a uterine rupture will occur. This article reviews the data regarding these antepartum and intrapartum predictors for uterine rupture. The author hopes that the information presented in this article will help clinicians assess an individual's risk for uterine rupture.

  9. Diagnosis and perioperative management of ruptured AAA mimicking symptomatic groin hernia

    PubMed Central

    Klein, Holger Jan; Becker, Daniel; Rancic, Zoran

    2015-01-01

    Introduction Ruptured abdominal aortic aneurysm (RAAA) can infrequently present as symptomatic groin hernia. This misleading form of presentation often leads to erroneous preoperative management resulting in poor survival. Case presentation Two patients with RAAA mimicking symptomatic groin hernia underwent different preoperative managements pointing out the importance of the principles of hypotensive haemostasis in the scope of this emergency scenario. Conclusion Computed Tomography Angiography (CTA) remains the recommended diagnostic tool—for both safe diagnosis of the ruptured aneurysm and precise preoperative planning. Endovascular aortic repair of the RAAA—if feasible—is the treatment of choice. This rare form of RAAA manifestation should call physicians attention—especially in patients with known abdominal aortic aneurysms in their preceding medical history. PMID:26656148

  10. Estimation of wall properties and wall strength of aortic aneurysms using modern imaging techniques. One more step towards a patient-specific assessment of aneurysm rupture risk.

    PubMed

    Kontopodis, Nikolaos; Georgakarakos, Efstratios; Metaxa, Eleni; Pagonidis, Konstantinos; Papaharilaou, Yannis; Ioannou, Christos V

    2013-08-01

    Abdominal aortic aneurysmal disease is a major health problem with rupture representing its main complication accompanied by great mortality. Elective repair is currently performed with mortality rates <3%, based upon size or expansion rate, with a recommended threshold of 5.5 cm maximum diameter or >1cm/year enlargement. It is well established that even small AAAs without indication for surgical repair can experience rupture with catastrophic outcomes whereas larger aneurysms often remain intact for a long period. It is recognized, therefore, that the currently used, maximum diameter criterion can not accurately predict AAAs evolution. There is increasing interest in the role of patient-specific biomechanical profiling of AAA development and rupture. Biomechanically, rupture of a vessel occurs when intravascular forces exceed vessel wall structural endurance. Peak Wall Stress (PWS) has been previously shown to better identify AAAs prone to rupture than maximum diameter, but currently stress analysis takes into account several assumptions that influence results to a large extent and limit their use. Moreover stress represents only one of two determinants of rupture risk according to the biomechanical perspective. Wall strength and mechanical properties on the other hand cannot be assessed in vivo but only ex vivo through mechanical studies with mean values of these parameters taken into account for rupture risk estimations. New possibilities in the field of aortic imaging offer promising tools for the validation and advancement of stress analysis and the in vivo evaluation of AAAs' wall properties and wall strength. Documentation of aortic wall motion during cardiac cycle is now feasible through ECG-gated multi-detector CT imaging offering new possibilities towards an individualized method for rupture risk and expansion-rate predictions based on data acquired in vivo. PMID:23714223

  11. Adipocyte in vascular wall can induce the rupture of abdominal aortic aneurysm

    PubMed Central

    Kugo, Hirona; Zaima, Nobuhiro; Tanaka, Hiroki; Mouri, Youhei; Yanagimoto, Kenichi; Hayamizu, Kohsuke; Hashimoto, Keisuke; Sasaki, Takeshi; Sano, Masaki; Yata, Tatsuro; Urano, Tetsumei; Setou, Mitsutoshi; Unno, Naoki; Moriyama, Tatsuya

    2016-01-01

    Abdominal aortic aneurysm (AAA) is a vascular disease involving the gradual dilation of the abdominal aorta. It has been reported that development of AAA is associated with inflammation of the vascular wall; however, the mechanism of AAA rupture is not fully understood. In this study, we investigated the mechanism underlying AAA rupture using a hypoperfusion-induced animal model. We found that the administration of triolein increased the AAA rupture rate in the animal model and that the number of adipocytes was increased in ruptured vascular walls compared to non-ruptured walls. In the ruptured group, macrophage infiltration and the protein levels of matrix metalloproteinases 2 and 9 were increased in the areas around adipocytes, while collagen-positive areas were decreased in the areas with adipocytes compared to those without adipocytes. The administration of fish oil, which suppresses adipocyte hypertrophy, decreased the number and size of adipocytes, as well as decreased the risk of AAA rupture ratio by 0.23 compared to the triolein administered group. In human AAA samples, the amount of triglyceride in the adventitia was correlated with the diameter of the AAA. These results suggest that AAA rupture is related to the abnormal appearance of adipocytes in the vascular wall. PMID:27499372

  12. Adipocyte in vascular wall can induce the rupture of abdominal aortic aneurysm.

    PubMed

    Kugo, Hirona; Zaima, Nobuhiro; Tanaka, Hiroki; Mouri, Youhei; Yanagimoto, Kenichi; Hayamizu, Kohsuke; Hashimoto, Keisuke; Sasaki, Takeshi; Sano, Masaki; Yata, Tatsuro; Urano, Tetsumei; Setou, Mitsutoshi; Unno, Naoki; Moriyama, Tatsuya

    2016-01-01

    Abdominal aortic aneurysm (AAA) is a vascular disease involving the gradual dilation of the abdominal aorta. It has been reported that development of AAA is associated with inflammation of the vascular wall; however, the mechanism of AAA rupture is not fully understood. In this study, we investigated the mechanism underlying AAA rupture using a hypoperfusion-induced animal model. We found that the administration of triolein increased the AAA rupture rate in the animal model and that the number of adipocytes was increased in ruptured vascular walls compared to non-ruptured walls. In the ruptured group, macrophage infiltration and the protein levels of matrix metalloproteinases 2 and 9 were increased in the areas around adipocytes, while collagen-positive areas were decreased in the areas with adipocytes compared to those without adipocytes. The administration of fish oil, which suppresses adipocyte hypertrophy, decreased the number and size of adipocytes, as well as decreased the risk of AAA rupture ratio by 0.23 compared to the triolein administered group. In human AAA samples, the amount of triglyceride in the adventitia was correlated with the diameter of the AAA. These results suggest that AAA rupture is related to the abnormal appearance of adipocytes in the vascular wall. PMID:27499372

  13. Serum angiotensin-converting enzyme 2 is an independent risk factor for in-hospital mortality following open surgical repair of ruptured abdominal aortic aneurysm

    PubMed Central

    Nie, Wanpin; Wang, Yan; Yao, Kai; Wang, Zheng; Wu, Hao

    2016-01-01

    Open surgical repair (OSR) is a conventional surgical method used in the repair a ruptured abdominal aortic aneurysm (AAA); however, OSR results in high perioperative mortality rates. The level of serum angiotensin-converting enzyme 2 (ACE2) has been reported to be an independent risk factor for postoperative in-hospital mortality following major cardiopulmonary surgery. In the present study, the association of serum ACE2 levels with postoperative in-hospital mortality was investigated in patients undergoing OSR for ruptured AAA. The study enrolled 84 consecutive patients underwent OSR for ruptured AAA and were subsequently treated in the intensive care unit. Patients who succumbed postoperatively during hospitalization were defined as non-survivors. Serum ACE2 levels were measured in all patients prior to and following the surgery using ELISA kits. The results indicated that non-survivors showed significantly lower mean preoperative and postoperative serum ACE2 levels when compared with those in survivors. Multivariate logistic regression analysis also showed that, subsequent to adjusting for potential confounders, the serum ACE2 level on preoperative day 1 showed a significant negative association with the postoperative in-hospital mortality. This was confirmed by multivariate hazard ratio analysis, which showed that, subsequent to adjusting for the various potential confounders, the risk of postoperative in-hospital mortality remained significantly higher in the two lowest serum ACE2 level quartiles compared with that in the highest quartile on preoperative day 1. In conclusion, the present study provided the first evidence supporting that the serum ACE2 level is an independent risk factor for the in-hospital mortality following OSR for ruptured AAA. Furthermore, low serum ACE2 levels on preoperative day 1 were found to be associated with increased postoperative in-hospital mortality. Therefore, the serum ACE2 level on preoperative day 1 may be a potential

  14. Changes in geometric configuration and biomechanical parameters of a rapidly growing abdominal aortic aneurysm may provide insight in aneurysms natural history and rupture risk

    PubMed Central

    2013-01-01

    Background Abdominal aortic aneurysms (AAA) are currently being treated based on the maximum diameter criterion which has often been proven insufficient to determine rupture risk in case of every AAA. We analyzed a rare case of an AAA which presented an extremely fast growth focusing on biomechanical determinants that may indicate a high risk profile. The examination of such a case is expected to motivate future research towards patient-specific rupture risk estimations. Methods An initially small AAA (maximum diameter: 4.5 cm) was followed-up and presented a growth of 1 cm in only 6-months of surveillance becoming suitable for surgical repair. Changes of morphometric characteristics regarding AAA, thrombus and lumen volumes, cross-sectional areas, thrombus maximum thickness and eccentricity, and maximum centerline curvature were recorded. Moreover biomechanical variables concerning Peak Wall Stress, AAA surface area exposed to high stress and redistribution of stress during follow-up were also assessed. Results Total aneurysm volume increased from 85 to 120 ml which regarded thrombus deposition since lumen volume remained stable. Thrombus deposition was eccentric regarding anterior AAA segment while its thickness increased from 0.3 cm to 1.6 cm. Moreover there was an anterior bulging over time as depicted by an increase in maximum centerline curvature from 0.4 cm-1 to 0.5 cm-1. Peak Wall Stress (PWS) exerted on aneurysm wall did not change significantly over time, slightly decreasing from 22 N/cm2 to 21 N/cm2. At the same time the area under high wall stress remained practically constant (9.9 cm2 at initial vs 9.7 cm2 at final examination) but there was a marked redistribution of wall stress against the posterior aneurysmal wall over time. Conclusion Aneurysm area under high stress and redistribution of stress against the posterior wall due to changes in geometric configuration and thrombus deposition over time may have implications to aneurysms natural

  15. Determining the influence of calcification on the failure properties of abdominal aortic aneurysm (AAA) tissue.

    PubMed

    O'Leary, Siobhan A; Mulvihill, John J; Barrett, Hilary E; Kavanagh, Eamon G; Walsh, Michael T; McGloughlin, Tim M; Doyle, Barry J

    2015-02-01

    Varying degrees of calcification are present in most abdominal aortic aneurysms (AAAs). However, their impact on AAA failure properties and AAA rupture risk is unclear. The aim of this work is evaluate and compare the failure properties of partially calcified and predominantly fibrous AAA tissue and investigate the potential reasons for failure. Uniaxial mechanical testing was performed on AAA samples harvested from 31 patients undergoing open surgical repair. Individual tensile samples were divided into two groups: fibrous (n=31) and partially calcified (n=38). The presence of calcification was confirmed by fourier transform infrared spectroscopy (FTIR). A total of 69 mechanical tests were performed and the failure stretch (λf), failure stress (σf) and failure tension (Tf) were recorded for each test. Following mechanical testing, the failure sites of a subset of both tissue types were examined using scanning electron microscopy (SEM)/energy dispersive X-ray spectroscopy (EDS) to investigate the potential reasons for failure. It has been shown that the failure properties of partially calcified tissue are significantly reduced compared to fibrous tissue and SEM and EDS results suggest that the junction between a calcification deposit and the fibrous matrix is highly susceptible to failure. This study implicates the presence of calcification as a key player in AAA rupture risk and provides further motivation for the development of non-invasive methods of measuring calcification.

  16. Determining the influence of calcification on the failure properties of abdominal aortic aneurysm (AAA) tissue.

    PubMed

    O'Leary, Siobhan A; Mulvihill, John J; Barrett, Hilary E; Kavanagh, Eamon G; Walsh, Michael T; McGloughlin, Tim M; Doyle, Barry J

    2015-02-01

    Varying degrees of calcification are present in most abdominal aortic aneurysms (AAAs). However, their impact on AAA failure properties and AAA rupture risk is unclear. The aim of this work is evaluate and compare the failure properties of partially calcified and predominantly fibrous AAA tissue and investigate the potential reasons for failure. Uniaxial mechanical testing was performed on AAA samples harvested from 31 patients undergoing open surgical repair. Individual tensile samples were divided into two groups: fibrous (n=31) and partially calcified (n=38). The presence of calcification was confirmed by fourier transform infrared spectroscopy (FTIR). A total of 69 mechanical tests were performed and the failure stretch (λf), failure stress (σf) and failure tension (Tf) were recorded for each test. Following mechanical testing, the failure sites of a subset of both tissue types were examined using scanning electron microscopy (SEM)/energy dispersive X-ray spectroscopy (EDS) to investigate the potential reasons for failure. It has been shown that the failure properties of partially calcified tissue are significantly reduced compared to fibrous tissue and SEM and EDS results suggest that the junction between a calcification deposit and the fibrous matrix is highly susceptible to failure. This study implicates the presence of calcification as a key player in AAA rupture risk and provides further motivation for the development of non-invasive methods of measuring calcification. PMID:25482218

  17. Distribution of Wall Stress in Abdominal Aortic Aneurysm (AAA)

    NASA Astrophysics Data System (ADS)

    Lasheras, Juan

    2005-11-01

    Abdominal aortic aneurysm (AAA) rupture is believed to occur when the mechanical stress acting on the wall exceeds the strength of the wall tissue. Therefore, knowledge of the AAA wall stress distribution could be useful in assessing its risk of rupture. In our research, a finite element analysis was used to determine the wall stresses both in idealized models and in a real clinical model in which the aorta was considered isotropic with nonlinear material properties and was loaded with a given pressure. In the idealized models, both maximum diameter and asymmetry were found to have substantial influence on the distribution of the wall stress. The thrombus inside the AAA was also found to help protecting the walls from high stresses. Using CT scans of the AAA, the actual geometry of the aneurysm was reconstructed and we found that wall tension increases on the flatter surface (typically corresponds to the posterior surface) and at the inflection points of the bulge. In addition to the static analysis, we also performed simulations of the effect of unsteady pressure wave propagation inside the aneurysm.

  18. Morphology Parameters for Intracranial Aneurysm Rupture Risk Assessment

    PubMed Central

    Dhar, Sujan; Tremmel, Markus; Mocco, J; Kim, Minsuok; Yamamoto, Junichi; Siddiqui, Adnan H.; Hopkins, L. Nelson; Meng, Hui

    2008-01-01

    OBJECTIVE The aim of this study is to identify image-based morphological parameters that correlate with human intracranial aneurysm (IA) rupture. METHODS For 45 patients with terminal or sidewall saccular IAs (25 unruptured, 20 ruptured), three-dimensional geometries were evaluated for a range of morphological parameters. In addition to five previously studied parameters (aspect ratio, aneurysm size, ellipticity index, nonsphericity index, and undulation index), we defined three novel parameters incorporating the parent vessel geometry (vessel angle, aneurysm [inclination] angle, and [aneurysm-to-vessel] size ratio) and explored their correlation with aneurysm rupture. Parameters were analyzed with a two-tailed independent Student's t test for significance; significant parameters (P < 0.05) were further examined by multivariate logistic regression analysis. Additionally, receiver operating characteristic analyses were performed on each parameter. RESULTS Statistically significant differences were found between mean values in ruptured and unruptured groups for size ratio, undulation index, nonsphericity index, ellipticity index, aneurysm angle, and aspect ratio. Logistic regression analysis further revealed that size ratio (odds ratio, 1.41; 95% confidence interval, 1.03−1.92) and undulation index (odds ratio, 1.51; 95% confidence interval, 1.08−2.11) had the strongest independent correlation with ruptured IA. From the receiver operating characteristic analysis, size ratio and aneurysm angle had the highest area under the curve values of 0.83 and 0.85, respectively. CONCLUSION Size ratio and aneurysm angle are promising new morphological metrics for IA rupture risk assessment. Because these parameters account for vessel geometry, they may bridge the gap between morphological studies and more qualitative location-based studies. PMID:18797347

  19. Radiographic Risk Factors for Contralateral Rupture in Dogs with Unilateral Cranial Cruciate Ligament Rupture

    PubMed Central

    Chuang, Connie; Ramaker, Megan A.; Kaur, Sirjaut; Csomos, Rebecca A.; Kroner, Kevin T.; Bleedorn, Jason A.; Schaefer, Susan L.; Muir, Peter

    2014-01-01

    Background Complete cranial cruciate ligament rupture (CR) is a common cause of pelvic limb lameness in dogs. Dogs with unilateral CR often develop contralateral CR over time. Although radiographic signs of contralateral stifle joint osteoarthritis (OA) influence risk of subsequent contralateral CR, this risk has not been studied in detail. Methodology/Principal Findings We conducted a retrospective longitudinal cohort study of client-owned dogs with unilateral CR to determine how severity of radiographic stifle synovial effusion and osteophytosis influence risk of contralateral CR over time. Detailed survival analysis was performed for a cohort of 85 dogs after case filtering of an initial sample population of 513 dogs. This population was stratified based on radiographic severity of synovial effusion (graded on a scale of 0, 1, and 2) and severity of osteophytosis (graded on a scale of 0, 1, 2, and 3) of both index and contralateral stifle joints using a reproducible scoring method. Severity of osteophytosis in the index and contralateral stifles was significantly correlated. Rupture of the contralateral cranial cruciate ligament was significantly influenced by radiographic OA in both the index and contralateral stifles at diagnosis. Odds ratio for development of contralateral CR in dogs with severe contralateral radiographic stifle effusion was 13.4 at one year after diagnosis and 11.4 at two years. Odds ratio for development of contralateral CR in dogs with severe contralateral osteophytosis was 9.9 at one year after diagnosis. These odds ratios were associated with decreased time to contralateral CR. Breed, age, body weight, gender, and tibial plateau angle did not significantly influence time to contralateral CR. Conclusion Subsequent contralateral CR is significantly influenced by severity of radiographic stifle effusion and osteophytosis in the contralateral stifle, suggesting that synovitis and arthritic joint degeneration are significant factors in the

  20. Abdominal Aortic Aneurysm (AAA)

    MedlinePlus

    ... Resources Professions Site Index A-Z Abdominal Aortic Aneurysm (AAA) Abdominal aortic aneurysm (AAA) occurs when atherosclerosis ... aortic aneurysm treated? What is an abdominal aortic aneurysm? The aorta, the largest artery in the body, ...

  1. Robust and fast abdominal aortic aneurysm centerline detection for rupture risk prediction

    NASA Astrophysics Data System (ADS)

    Zhang, Hong; Finol, Ender A.

    2011-03-01

    This work describes a robust and fast semi-automatic approach for Abdominal Aortic Aneurysm (AAA) centerline detection. AAA is a vascular disease accompanied by progressive enlargement of the abdominal aorta, which leads to rupture if left untreated, an event that accounts for the 13th leading cause of death in the U.S. The lumen centerline can be used to provide the initial starting points for thrombus segmentation. Different from other methods, which are mostly based on region growing and suffer from problems of leakage and heavy computational burden, we propose a novel method based on online classification. An online version of the adaboost classifier based on steerable features is applied to AAA MRI data sets with a rectangular box enclosing the lumen in the first slice. The classifier is updated during the tracking process by using the testing result of the previous image as the new training data. Unlike traditional offline versions, the online classifier can adjust parameters automatically when a leakage occurs. With the help of integral images on the computation of haar-like features, the method can achieve nearly real time processing (about 2 seconds per image on a standard workstation). Ten ruptured and ten unruptured AAA data sets were processed and the tortuosity of the 20 centerlines was calculated. The correlation coefficient of the tortuosity was calculated to illustrate the significance of the prediction with the proposed method. The mean relative accuracy is 95.68% with a standard deviation of 0.89% when compared to a manual segmentation procedure. The correlation coefficient is 0.394.

  2. Non-invasive in vivo time-dependent strain measurement method in human abdominal aortic aneurysms: Towards a novel approach to rupture risk estimation.

    PubMed

    Nagy, Róbert; Csobay-Novák, Csaba; Lovas, Attila; Sótonyi, Péter; Bojtár, Imre

    2015-07-16

    We aim to introduce a novel, inverse method for in vivo material parameter identification of human abdominal aortic aneurysms (AAA), which could overcome one of the greatest sources of uncertainty in patient-specific simulations, and could also serve as a rapid, patient-calibrated, novel measure of aneurysm rupture risk. As an initial step, the determination of the kinematic fields is presented here. Images of the AAA lumen, acquired in 10 discrete time-steps through a stabilized cardiac cycle by electrocardiogram-gated computer tomography angiography, are used to approximate the in vivo, time dependent kinematic fields of the arterial wall using a novel, incompressible Kirchhoff-Love shell element implemented into the isogeometric analysis framework. Defining a smoothing parametric surface via 2D bicubic spline fitting in the spatial, and by harmonic regression in the temporal domain, we are able to adequately mitigate the measurement inaccuracy. The ill-posedness of the problem requires certain assumptions on the displacement. In our case, based on numerical fluid structure interaction simulation observations, we hypothesized the incremental displacement vector of the reference surface to coincide with its corrected normal; hence the periodic movement was assured. Finally, we present two examples: an AAA and an undilated calcificated aorta. Strains in the diseased part were compared to those in a healthy arterial section of the same patient and found to have significant differences in both specimens. In the case of AAAs, high spatial gradients surrounding the dilated part indicate abrupt changes in material properties, a phenomenon less significant for the atherosclerotic case. PMID:25980555

  3. Robust infrarenal aortic aneurysm lumen centerline detection for rupture status classification

    PubMed Central

    Zhang, Hong; Kheyfets, Vitaly O.; Finol, Ender A

    2013-01-01

    The objective of this work is to develop a robust method for human abdominal aortic aneurysm (AAA) centerline detection that can contribute to the accurate computation of features for the prediction of AAA rupture risk. A semiautomatic algorithm is proposed for detecting the lumen centerline in contrast-enhanced abdominal computed tomography images based on online adaboost classifiers, which does not require prior image segmentation. The algorithm was developed and applied to thirty ruptured and thirty unruptured AAA image data sets and the tortuosities of the detected centerline were measured to assess the correlation between AAA tortuosity and the binary ruptured and unruptured labels. The lumen of each data set was segmented manually by a trained radiologist and the resulting centerlines of each data set were defined as the gold standard to evaluate the accuracy of the algorithm and to compare it against two widely used segmentation techniques. The average mean relative accuracy of the offline adaboost classifier is 91.9% with a standard deviation of 1.6%; for the online adaboost classifier it is 93.6% with a standard deviation of 1.9% (p<0.05). The online adaboost classifier outperforms the offline adaboost classifier while their computational costs are similar. Aneurysm tortuosity computed from an accurately derived lumen centerline using online adaboost is statistically higher for ruptured aneurysms compared to unruptured aneurysms, indicating that tortuosity can be used to assess rupture risk in the vascular clinic. PMID:23608300

  4. A Review of Computational Methods to Predict the Risk of Rupture of Abdominal Aortic Aneurysms

    PubMed Central

    Canchi, Tejas; Kumar, S. D.; Ng, E. Y. K.; Narayanan, Sriram

    2015-01-01

    Computational methods have played an important role in health care in recent years, as determining parameters that affect a certain medical condition is not possible in experimental conditions in many cases. Computational fluid dynamics (CFD) methods have been used to accurately determine the nature of blood flow in the cardiovascular and nervous systems and air flow in the respiratory system, thereby giving the surgeon a diagnostic tool to plan treatment accordingly. Machine learning or data mining (MLD) methods are currently used to develop models that learn from retrospective data to make a prediction regarding factors affecting the progression of a disease. These models have also been successful in incorporating factors such as patient history and occupation. MLD models can be used as a predictive tool to determine rupture potential in patients with abdominal aortic aneurysms (AAA) along with CFD-based prediction of parameters like wall shear stress and pressure distributions. A combination of these computer methods can be pivotal in bridging the gap between translational and outcomes research in medicine. This paper reviews the use of computational methods in the diagnosis and treatment of AAA. PMID:26509168

  5. AAAS: Politics. . . and Science

    ERIC Educational Resources Information Center

    Science News, 1978

    1978-01-01

    Reviews topics discussed during the American Association for the Advancement of Science (AAAS) meeting held in Washington, D.C. Topics included: the equal rights amendment, laetrile, nuclear radiation hazards, sociobiology, and various science topics. (SL)

  6. Science Education at AAAS

    ERIC Educational Resources Information Center

    Livermore, Arthur H.

    1975-01-01

    Describes several programs of the American Association for the Advancement of Science (AAAS) Office of Science Education (OSE), including short courses offered in the natural and social sciences, mathematics, and engineering to college teachers. Discusses several OSE publications. (MLH)

  7. AAA Foundation for Traffic Safety

    MedlinePlus

    ... Survey: Teens should be wired less while driving, AAA Arizona says ... - ABC15 Arizona Graduated Licensing Laws - Insurance ... of Top Deadly Mistakes Made by Teen Drivers -- AAA More... Spotlight American Driving Survey This survey provides ...

  8. Incidence and Risk Factors for Rebleeding during Cerebral Angiography for Ruptured Intracranial Aneurysms

    PubMed Central

    Lim, Yong Cheol; Kim, Chang-Hyun; Kim, Yong Bae; Joo, Jin-Yang; Shin, Yong Sam

    2015-01-01

    Purpose The purpose was to evaluate the incidence and risk factors for rebleeding during cerebral angiography in ruptured intracranial aneurysms. Materials and Methods Among 1896 patients with ruptured intracranial aneurysms between September 2006 and December 2013, a total of 11 patients who experienced rebleeding of the ruptured aneurysms during digital subtraction angiography (DSA) were recruited in this study. Results There were 184 patients (9.7%) who had suffered rebleeding prior to the securing procedure. Among them, 11 patients experienced rebleeding during DSA and other 173 patients at a time other than DSA. Eight (72.7%) of the 11 patients experienced rebleeding during three-dimensional rotational angiography (3DRA). The incidence of rebleeding during DSA was 0.6% in patients with ruptured intracranial aneurysms. Multivariate logistic regression analysis showed that aneurysm location in anterior circulation [odds ratio=14.286; 95% confidence interval (CI), 1.877 to 250.0; p=0.048] and higher aspect ratio (odds ratio=3.040; 95% CI, 1.896 to 10.309; p=0.041) remained independent risk factors for rebleeding during DSA. Conclusion Ruptured aneurysms located in anterior circulation with a high aspect ratio might have the risk of rebleeding during DSA, especially during 3DRA. PMID:25683988

  9. Type 2 Diabetes and Risk of Rupture of Saccular Intracranial Aneurysm in Eastern Finland

    PubMed Central

    Lindgren, Antti E.; Kurki, Mitja I.; Riihinen, Annamaija; Koivisto, Timo; Ronkainen, Antti; Rinne, Jaakko; Hernesniemi, Juha; Eriksson, Johan G.; Jääskeläinen, Juha E.; von und zu Fraunberg, Mikael

    2013-01-01

    OBJECTIVE Type 2 diabetes is a risk factor for other forms of stroke, but its association with subarachnoid hemorrhage (SAH) from ruptured saccular intracranial aneurysm (sIA) has remained unclear. RESEARCH DESIGN AND METHODS Kuopio Intracranial Aneurysm Database (www.uef.fi/ns) includes all ruptured and unruptured sIA cases from a defined catchment population in eastern Finland since 1980. We compared the age-adjusted incidences of type 2 diabetes in 1,058 ruptured and 484 unruptured sIA patients during 1994–2008, using the national registry of prescribed medicine purchases. RESULTS Of the 1,058 ruptured sIA patients, 43% were males and 57% females, with a median age at rupture of 51 and 56 years, respectively. From 1994 to 2008 or until death, 9% had been prescribed antidiabetes medication (ADM) with a median starting age of 58 years for males and 66 years for females. Of the 484 unruptured sIA patients, 44% were males and 56% females, with a median age at the diagnosis of 53 and 55 years, respectively, and 9% had used ADM, with a median starting age of 61 years for males and 66 years for females. The incidence of type 2 diabetes was highest in the age-group 60–70 years, with no significant differences between the ruptured and unruptured sIA patients. CONCLUSIONS Our study suggests that type 2 diabetes does not increase the risk of rupture of sIA, which is by far the most frequent cause of nontraumatic SAH. PMID:23536581

  10. Differentiation, self-other representations, and rupture-repair processes: Predicting child maltreatment-risk

    PubMed Central

    Skowron, Elizabeth A.; Kozlowski, JoEllen M.; Pincus, Aaron L.

    2010-01-01

    This set of studies was designed to examine the relational underpinnings of child abuse potential in a sample of 51 urban families. In Study 1, lower maternal differentiation of self—most notably, greater emotional reactivity and greater emotional cutoff—along with self-attacking introjects, together distinguished mothers at higher risk (vs. lower risk) for child maltreatment (CM). In Study 2, patterns of interactive rupture and repair were examined in a subsample of n = 15 families and found to vary as a function of risk for CM. Specifically, SASB coding (Benjamin, 1996, 2003) of mother-children interactions during two moderately stressful lab tasks revealed higher rates of interactive mismatch and mother-initiated ruptures, and fewer successful repairs in families at higher-risk-for-CM, relative to families at lower-risk. Implications for counseling and directions for further translational research are discussed. PMID:20729978

  11. Risk of Hemorrhage in Combined Neuroform Stenting and Coil Embolization of Acutely Ruptured Intracranial Aneurysms

    PubMed Central

    Jankowitz, B.; Thomas, A.J.; Vora, N.; Gupta, R.; Levy, E.; Yamamoto, J.; Kassam, A.; Gologorsky, Y.; Panapitiya, N.; Sandhu, E.; Crago, E.; Hricik, A.; Lee, K.; Gallek, M.; Jovin, T.; Horowitz, M.

    2008-01-01

    Summary Stenting as adjuvant therapy for the coiling of acutely ruptured aneurysms remains controversial due to the necessity of anticoagulation and antiplatelet medications. We report our experience using the Neuroform stent in the management of 41 aneurysms in 40 patients over a period of three years. For aneurysms whose open surgical risk remains excessive with a morphology that would preclude complete embolization, the risks of stenting may be warranted. PMID:20557738

  12. The energy loss may predict rupture risks of anterior communicating aneurysms: a preliminary result.

    PubMed

    Hu, Peng; Qian, Yi; Lee, Chong-Joon; Zhang, Hong-Qi; Ling, Feng

    2015-01-01

    Anterior communicating artery (ACoA) aneurysms are well documented to have a higher rupture risk compared with aneurysms at other locations. However, the risk predicting factors for these aneurysms still remain unclear due to the complex arteries geometries and flow patterns involved. The authors introduce a comprehensive method to quantitatively illustrate the development of ACoA aneurysms using a computational fluid dynamics (CFD) approach. Seven ACoA aneurysms, which included 2 ruptured and 5 unruptured aneurysms, were employed. Patient-specific whole anterior circulation geometries were segmented to simulate the real circumstances in vivo. The energy losses (EL) and flow architectures of these 7 aneurysms were evaluated using an algorithm modality. Overall, the 2 ruptured aneurysms, along with 1 unruptured aneurysm that was defined as highly likely to rupture due to ACoA location and a bleb sitting at the top of the dome, had a significantly larger EL and more complex and unstable flow architecture than the others. Two aneurysms had a negative value of EL indicating that the geometries with aneurysms of the anterior communicating complex (ACC) had a smaller loss of energy than the geometries without aneurysms. Despite a small sample size resulting in a low statistical significance, EL may serve as a development predictor of ACoA aneurysms. PMID:26064320

  13. Prevalence of previously undiagnosed abdominal aortic aneurysms in the area of Como: the ComoCuore "looking for AAA" ultrasonography screening.

    PubMed

    Corrado, Giovanni; Durante, Alessandro; Genchi, Vincenzo; Trabattoni, Loris; Beretta, Sandro; Rovelli, Enza; Foglia-Manzillo, Giovanni; Ferrari, Giovanni

    2016-08-01

    The prognosis for abdominal aortic aneurysm (AAA) rupture is poor. Long-term follow-up of population-based randomized trials has demonstrated that ultrasound (US) screening for abdominal aortic aneurysms (AAAs) measuring 3 cm or greater decreases AAA-related mortality rates and is cost-effective. We though to prospectively perform during a 26-month period a limited US examination of the infrarenal aorta in volunteers of both gender aged 60-85 years without history of AAA living in the area of Como, Italy. From September 2010 to November 2013 ComoCuore, a no-profit nongovernmental association, enrolled 1555 people (aged 68.8 ± 6.8 years; 48.6 % males). Clinical data and a US imaging of the aorta were collected for each participant. AAA was found in 22 volunteers (1.4 %) mainly males (2.5 % in males vs. 0.4 % in females p = 0.005). Overall, the prevalence of cardiovascular risk factors was higher in patients with vs. without AAA (mean 2.9 ± 3.0 vs. 1.4 ± 1.0 respectively, p < 0.0001). Independent predictors of AAA on multivariate analysis were age (OR 1.14, 1.06-1.22; p < 0.0001), male gender (OR 8.23, 1.79-37.91; p = 0.007), and both current (OR 4.98, 1.57-15.79; p = 0.007) and previous smoking (OR 2.76, 1.12-8.94; p = 0.03). Our study confirms the feasibility of one time US screening for AAA in a large cohort of asymptomatic people. Independent predictors of AAA were male sex, older age and a history of smoking. Accordingly to recent data the prevalence of AAA seems to be declining, maybe due to a reduction of smoking in Italy. PMID:27215751

  14. Prevalence of previously undiagnosed abdominal aortic aneurysms in the area of Como: the ComoCuore "looking for AAA" ultrasonography screening.

    PubMed

    Corrado, Giovanni; Durante, Alessandro; Genchi, Vincenzo; Trabattoni, Loris; Beretta, Sandro; Rovelli, Enza; Foglia-Manzillo, Giovanni; Ferrari, Giovanni

    2016-08-01

    The prognosis for abdominal aortic aneurysm (AAA) rupture is poor. Long-term follow-up of population-based randomized trials has demonstrated that ultrasound (US) screening for abdominal aortic aneurysms (AAAs) measuring 3 cm or greater decreases AAA-related mortality rates and is cost-effective. We though to prospectively perform during a 26-month period a limited US examination of the infrarenal aorta in volunteers of both gender aged 60-85 years without history of AAA living in the area of Como, Italy. From September 2010 to November 2013 ComoCuore, a no-profit nongovernmental association, enrolled 1555 people (aged 68.8 ± 6.8 years; 48.6 % males). Clinical data and a US imaging of the aorta were collected for each participant. AAA was found in 22 volunteers (1.4 %) mainly males (2.5 % in males vs. 0.4 % in females p = 0.005). Overall, the prevalence of cardiovascular risk factors was higher in patients with vs. without AAA (mean 2.9 ± 3.0 vs. 1.4 ± 1.0 respectively, p < 0.0001). Independent predictors of AAA on multivariate analysis were age (OR 1.14, 1.06-1.22; p < 0.0001), male gender (OR 8.23, 1.79-37.91; p = 0.007), and both current (OR 4.98, 1.57-15.79; p = 0.007) and previous smoking (OR 2.76, 1.12-8.94; p = 0.03). Our study confirms the feasibility of one time US screening for AAA in a large cohort of asymptomatic people. Independent predictors of AAA were male sex, older age and a history of smoking. Accordingly to recent data the prevalence of AAA seems to be declining, maybe due to a reduction of smoking in Italy.

  15. Risk assessment and risk scores in the management of aortic aneurysms.

    PubMed

    Von Meijenfeldt, Gerdine C I; Van Der Laan, Maarten J; Zeebregts, Clark J; Balm, Ron; Verhagen, Hence J M

    2016-04-01

    The decision whether to operate a patient or not can be challenging for a clinician for both ruptured abdominal aortic aneurysms (AAAs) as well as elective AAAs. Prior to surgical intervention it would be preferable that the clinician exactly knows which clinical variables lower or increase the chances of morbidity and mortality postintervention. To help in the preoperative counselling and shared decision making several clinical variables can be identified as risk factors and with these, risk models can be developed. An ideal risk score for aneurysm repair includes routinely obtained physiological and anatomical variables, has excellent discrimination and calibration, and is validated in different geographical areas. For elective AAA repair, several risk scores are available, for ruptured AAA treatment, these scores are far less well developed. In this manuscript, we describe the designs and results of published risk scores for elective and open repair. Also, suggestions for uniformly reporting of risk factors and their statistical analyses are described. Furthermore, the preliminary results of a new risk model for ruptured aortic aneurysm will be discussed. This score identifies age, hemoglobin, cardiopulmonary resuscitation and preoperative systolic blood pressure as risk factors after multivariate regression analysis. This new risk score can help to identify patients that would not benefit from repair, but it can also potentially identify patients who would benefit and therefore lower turndown rates. The challenge for further research is to expand on validation of already existing promising risk scores in order to come to a risk model with optimal discrimination and calibration.

  16. Interactions between collagen gene variants and risk of anterior cruciate ligament rupture.

    PubMed

    O'Connell, Kevin; Knight, Hayley; Ficek, Krzysztof; Leonska-Duniec, Agata; Maciejewska-Karlowska, Agnieszka; Sawczuk, Marek; Stepien-Slodkowska, Marta; O'Cuinneagain, Dion; van der Merwe, Willem; Posthumus, Michael; Cieszczyk, Pawel; Collins, Malcolm

    2015-01-01

    The COL5A1 and COL12A1 variants are independently associated with modulating the risk of anterior cruciate ligament (ACL) rupture in females. The objective of this study was to further investigate if COL3A1 and COL6A1 variants independently, as well as, collagen gene-gene interactions, modulate ACL rupture risk. Three hundred and thirty-three South African (SA, n = 242) and Polish (PL, n = 91) participants with diagnosed ACL ruptures and 378 controls (235 SA and 143 PL) were recruited. Participants were genotyped for COL3A1 rs1800255 G/A, COL5A1 rs12722 (T/C), COL6A1 rs35796750 (T/C) and COL12A1 rs970547 (A/G). No significant associations were identified between COL6A1 rs35796750 and COL3A1 rs1800255 genotypes and risk of ACL rupture in the SA cohort. The COL3A1 AA genotype was, however, significantly (p = 0.036) over-represented in the PL ACL group (9.9%, n = 9) when compared to the PL control (CON) group (2.8%, n = 4). Although there were genotype distribution differences between the SA and PL cohorts, the T+A-inferred pseudo-haplotype constructed from COL5A1 and COL12A1 was significantly over-represented in the female ACL group when compared to the female CON group within the SA (T+A ACL 50.5%, T+A CON 38.1%, p = 0.022), PL (T+A ACL 56.3%, T+A CON 36.3%, p = 0.029) and combined (T+A ACL 51.8%, T+A CON 37.5%, p = 0.004) cohorts. In conclusion, the novel main finding of this study was a significant interaction between the COL5A1 rs12722 T/C and COL12A1 rs970547 A/G variants and risk of ACL injury. These results highlight the importance of investigating gene-gene interactions in the aetiology of ACL ruptures in multiple independent cohorts. PMID:25073002

  17. Development and Analysis of Synthetic Composite Materials Emulating Patient AAA Wall Material Properties

    NASA Astrophysics Data System (ADS)

    Margossian, Christa M.

    Abdominal Aortic Aneurysm (AAA) rupture accounts for 14,000 deaths a year in the United States. Since the number of ruptures has not decreased significantly in recent years despite improvements in imaging and surgical procedures, there is a need for an accurate, noninvasive technique capable of establishing rupture risk for specific patients and discriminating lesions at high risk. In this project, synthetic composite materials replicating patient-specific wall stiffness and strength were developed and their material properties evaluated. Composites utilizing various fibers were developed to give a range of stiffness from 1825.75 kPa up through 8187.64 kPa with one base material, Sylgard 170. A range of strength from 631.12 kPa to 1083 kPa with the same base material was also found. By evaluating various base materials and various reinforcing fibers, a catalogue of stiffnesses and strengths was started to allow for adaptation to specific patient properties. Three specific patient properties were well-matched with two composites fabricated: silk thread-reinforced Sylgard 170 and silk thread-reinforced Dragon Skin 20. The composites showed similar stiffnesses to the specific patients while reaching target stresses at particular strains. Not all patients were matched with composites as of yet, but recommendations for future matches are able to be determined. These composites will allow for the future evaluation of flow-induced wall stresses in models replicating patient material properties and geometries.

  18. Sac Angiography and Glue Embolization in Emergency Endovascular Aneurysm Repair for Ruptured Abdominal Aortic Aneurysm

    SciTech Connect

    Koike, Yuya Nishimura, Jun-ichi Hase, Soichiro Yamasaki, Motoshige

    2015-04-15

    PurposeThe purpose of this study was to demonstrate a sac angiography technique and evaluate the feasibility of N-butyl cyanoacrylate (NBCA) embolization of the ruptured abdominal aortic aneurysm (AAA) sac in emergency endovascular aneurysm repair (EVAR) in hemodynamically unstable patients.MethodsA retrospective case series of three patients in whom sac angiography was performed during emergency EVAR for ruptured AAA was reviewed. After stent graft deployment, angiography within the sac of aneurysm (sac angiography) was performed by manually injecting 10 ml of contrast material through a catheter to identify the presence and site of active bleeding. In two patients, sac angiography revealed active extravasation of the contrast material, and NBCA embolization with a coaxial catheter system was performed to achieve prompt sealing.ResultsSac angiography was successful in all three patients. In the two patients who underwent NBCA embolization for aneurysm sac bleeding, follow-up computed tomography (CT) images demonstrated the accumulation of NBCA consistent with the bleeding site in preprocedural CT images.ConclusionsEVAR is associated with a potential risk of ongoing bleeding from type II or IV endoleaks into the disrupted aneurysm sac in patients with severe coagulopathy. Therefore, sac angiography and NBCA embolization during emergency EVAR may represent a possible technical improvement in the treatment of ruptured AAA in hemodynamically unstable patients.

  19. Risk assessment of severe accident-induced steam generator tube rupture

    SciTech Connect

    1998-03-01

    This report describes the basis, results, and related risk implications of an analysis performed by an ad hoc working group of the U.S. Nuclear Regulatory Commission (NRC) to assess the containment bypass potential attributable to steam generator tube rupture (SGTR) induced by severe accident conditions. The SGTR Severe Accident Working Group, comprised of staff members from the NRC`s Offices of Nuclear Reactor Regulation (NRR) and Nuclear Regulatory Research (RES), undertook the analysis beginning in December 1995 to support a proposed steam generator integrity rule. The work drew upon previous risk and thermal-hydraulic analyses of core damage sequences, with a focus on the Surry plant as a representative example. This analysis yielded new results, however, derived by predicting thermal-hydraulic conditions of selected severe accident scenarios using the SCDAP/RELAP5 computer code, flawed tube failure modeling, and tube failure probability estimates. These results, in terms of containment bypass probability, form the basis for the findings presented in this report. The representative calculation using Surry plant data indicates that some existing plants could be vulnerable to containment bypass resulting from tube failure during severe accidents. To specifically identify the population of plants that may pose a significant bypass risk would require more definitive analysis considering uncertainties in some assumptions and plant- and design-specific variables. 46 refs., 62 figs., 37 tabs.

  20. Experimental and computational studies on the flow fields in aortic aneurysms associated with deployment of AAA stent-grafts

    NASA Astrophysics Data System (ADS)

    Zhang, Xiwen; Yao, Zhaohui; Zhang, Yan; Xu, Shangdong

    2007-10-01

    Pulsatile flow fields in rigid abdominal aortic aneurysm (AAA) models were investigated numerically, and the simulation results are found in good agreement with particle image velocimetry (PIV) measurements. There are one or more vortexes in the AAA bulge, and a fairly high wall shear stress exists at the distal end, and thus the AAA is in danger of rupture. Medical treatment consists of inserting a vascular stent-graft in the AAA, which would decrease the blood impact to the inner walls and reduce wall shear stress so that the rupture could be prevented. A new computational model, based on porous medium model, was developed and results are documented. Therapeutic effect of the stent-graft was verified numerically with the new model.

  1. The effect of changes in barometric pressure on the risk of rupture of intracranial aneurysms.

    PubMed

    Landers, A T; Narotam, P K; Govender, S T; van Dellen, J R

    1997-06-01

    Several meteorological variables have been linked with an altered incidence of cerebrovascular disease. In particular, we had noticed that, following abrupt changes in weather, patients with aneurysmal subarachnoid haemorrhage (SAH) often presented in groups. This study was undertaken to determine whether changes in barometric pressure would be an important factor. A retrospective analysis of a two year period was carried out. Daily mean, peak and trough atmospheric pressures had been recorded independently by a weather bureau. Of the 157 patients with SAH due to a berry aneurysm, confirmed by CT and angiography, 60 were entered into the study. Patients residing outside the weather bureau region (n = 86), or where there was uncertainty of their day of ictus (n = 11), were excluded. Daily peak to trough pressure changes and mean monthly pressure fluctuations showed no association with an increased risk of SAH. However, a significant relationship between the incidence of onset of symptoms indicative of a rupture of the aneurysm and a change in barometric mean pressure (BMP) of > 10 hectapascals from the previous day was found (p = 0.0247). The calculated odds ratio of sustaining a SAH with this associated BMP change was therefore 2.7 times with a risk of 1-13 times at a 95% confidence level (p = 0.035).

  2. Novel Molecular Imaging Approaches to Abdominal Aortic Aneurysm Risk Stratification

    PubMed Central

    Toczek, Jakub; Meadows, Judith L.; Sadeghi, Mehran M.

    2015-01-01

    Selection of patients for abdominal aortic aneurysm (AAA) repair is currently based on aneurysm size, growth rate and symptoms. Molecular imaging of biological processes associated with aneurysm growth and rupture, e.g., inflammation and matrix remodeling, could improve patient risk stratification and lead to a reduction in AAA morbidity and mortality. 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) and ultrasmall superparamagnetic particles of iron oxide (USPIO) magnetic resonance imaging are two novel approaches to AAA imaging evaluated in clinical trials. A variety of other tracers, including those that target inflammatory cells and proteolytic enzymes (e.g., integrin αvβ3 and matrix metalloproteinases), have proven effective in preclinical models of AAA and show great potential for clinical translation. PMID:26763279

  3. CFD: computational fluid dynamics or confounding factor dissemination? The role of hemodynamics in intracranial aneurysm rupture risk assessment.

    PubMed

    Xiang, J; Tutino, V M; Snyder, K V; Meng, H

    2014-10-01

    Image-based computational fluid dynamics holds a prominent position in the evaluation of intracranial aneurysms, especially as a promising tool to stratify rupture risk. Current computational fluid dynamics findings correlating both high and low wall shear stress with intracranial aneurysm growth and rupture puzzle researchers and clinicians alike. These conflicting findings may stem from inconsistent parameter definitions, small datasets, and intrinsic complexities in intracranial aneurysm growth and rupture. In Part 1 of this 2-part review, we proposed a unifying hypothesis: both high and low wall shear stress drive intracranial aneurysm growth and rupture through mural cell-mediated and inflammatory cell-mediated destructive remodeling pathways, respectively. In the present report, Part 2, we delineate different wall shear stress parameter definitions and survey recent computational fluid dynamics studies, in light of this mechanistic heterogeneity. In the future, we expect that larger datasets, better analyses, and increased understanding of hemodynamic-biologic mechanisms will lead to more accurate predictive models for intracranial aneurysm risk assessment from computational fluid dynamics.

  4. Risk as Feelings in the Effect of Patient Outcomes on Physicians' Subsequent Treatment Decisions: A Randomized Trial and Manipulation Validation

    PubMed Central

    Hemmerich, Joshua A; Elstein, Arthur S; Schwarze, Margaret L; Moliski, Elizabeth G; Dale, William

    2013-01-01

    The present study tested predictions derived from the Risk as Feelings hypothesis about the effects of prior patients' negative treatment outcomes on physicians' subsequent treatment decisions. Two experiments at The University of Chicago, U.S.A., utilized a computer simulation of an abdominal aortic aneurysm (AAA) patient with enhanced realism to present participants with one of three experimental conditions: AAA rupture causing a watchful waiting death (WWD), perioperative death (PD), or a successful operation (SO), as well as the statistical treatment guidelines for AAA. Experiment 1 tested effects of these simulated outcomes on (n=76) laboratory participants' (university student sample) self-reported emotions, and their ratings of valence and arousal of the AAA rupture simulation and other emotion inducing picture stimuli. Experiment 2 tested two hypotheses: 1) that experiencing a patient WWD in the practice trial's experimental condition would lead physicians to choose surgery earlier, and 2) experiencing a patient PD would lead physicians to choose surgery later with the next patient. Experiment 2 presented (n=132) physicians (surgeons and geriatricians) with the same experimental manipulation and a second simulated AAA patient. Physicians then chose to either go to surgery or continue watchful waiting. The results of Experiment 1 demonstrated that the WWD experimental condition significantly increased anxiety, and was rated similarly to other negative and arousing pictures. The results of Experiment 2 demonstrated that, after controlling for demographics, baseline anxiety, intolerance for uncertainty, risk attitudes, and the influence of simulation characteristics, the WWD experimental condition significantly expedited decisions to choose surgery for the next patient. The results support the Risk as Feelings hypothesis on physicians' treatment decisions in a realistic AAA patient computer simulation. Bad outcomes affected emotions and decisions, even with

  5. Identification of rupture locations in patient-specific abdominal aortic aneurysms using experimental and computational techniques.

    PubMed

    Doyle, Barry J; Cloonan, Aidan J; Walsh, Michael T; Vorp, David A; McGloughlin, Timothy M

    2010-05-01

    In the event of abdominal aortic aneurysm (AAA) rupture, the outcome is often death. This paper aims to experimentally identify the rupture locations of in vitro AAA models and validate these rupture sites using finite element analysis (FEA). Silicone rubber AAA models were manufactured using two different materials (Sylgard 160 and Sylgard 170, Dow Corning) and imaged using computed tomography (CT). Experimental models were inflated until rupture with high speed photography used to capture the site of rupture. 3D reconstructions from CT scans and subsequent FEA of these models enabled the wall stress and wall thickness to be determined for each of the geometries. Experimental models ruptured at regions of inflection, not at regions of maximum diameter. Rupture pressures (mean+/-SD) for the Sylgard 160 and Sylgard 170 models were 650.6+/-195.1mmHg and 410.7+/-159.9mmHg, respectively. Computational models accurately predicted the locations of rupture. Peak wall stress for the Sylgard 160 and Sylgard 170 models was 2.15+/-0.26MPa at an internal pressure of 650mmHg and 1.69+/-0.38MPa at an internal pressure of 410mmHg, respectively. Mean wall thickness of all models was 2.19+/-0.40mm, with a mean wall thickness at the location of rupture of 1.85+/-0.33 and 1.71+/-0.29mm for the Sylgard 160 and Sylgard 170 materials, respectively. Rupture occurred at the location of peak stress in 80% (16/20) of cases and at high stress regions but not peak stress in 10% (2/20) of cases. 10% (2/20) of models had defects in the AAA wall which moved the rupture location away from regions of elevated stress. The results presented may further contribute to the understanding of AAA biomechanics and ultimately AAA rupture prediction.

  6. High-intensity interval exercise training before abdominal aortic aneurysm repair (HIT-AAA): protocol for a randomised controlled feasibility trial

    PubMed Central

    Tew, Garry A; Weston, Matthew; Kothmann, Elke; Batterham, Alan M; Gray, Joanne; Kerr, Karen; Martin, Denis; Nawaz, Shah; Yates, David; Danjoux, Gerard

    2014-01-01

    Introduction In patients with large abdominal aortic aneurysm (AAA), open surgical or endovascular aneurysm repair procedures are often used to minimise the risk of aneurysm-related rupture and death; however, aneurysm repair itself carries a high risk. Low cardiopulmonary fitness is associated with an increased risk of early post-operative complications and death following elective AAA repair. Therefore, fitness should be enhanced before aneurysm repair. High-intensity interval exercise training (HIT) is a potent, time-efficient strategy for enhancing cardiopulmonary fitness. Here, we describe a feasibility study for a definitive trial of a pre-operative HIT intervention to improve post-operative outcomes in patients undergoing elective AAA repair. Methods and analysis A minimum of 50 patients awaiting elective repair of a 5.5–7.0 cm infrarenal AAA will be allocated by minimisation to HIT or usual care control in a 1:1 ratio. The patients allocated to HIT will complete three hospital-based exercise sessions per week, for 4 weeks. Each session will include 2 or 4 min of high-intensity stationary cycling followed by the same duration of easy cycling or passive recovery, repeated until a total of 16 min of high-intensity exercise is accumulated. Outcomes to be assessed before randomisation and 24–48 h before aneurysm repair include cardiopulmonary fitness, maximum AAA diameter and health-related quality of life. In the post-operative period, we will record destination (ward or critical care unit), organ-specific morbidity, mortality and the durations of critical care and hospital stay. Twelve weeks after the discharge, participants will be interviewed to reassess quality of life and determine post-discharge healthcare utilisation. The costs associated with the exercise intervention and healthcare utilisation will be calculated. Ethics and dissemination Ethics approval was secured through Sunderland Research Ethics Committee. The findings of the trial

  7. Rupture processes of the 2015 Mw 7.9 Gorkha earthquake and its Mw 7.3 aftershock and their implications on the seismic risk

    NASA Astrophysics Data System (ADS)

    Liu, Chengli; Zheng, Yong; Wang, Rongjiang; Shan, Bin; Xie, Zujun; Xiong, Xiong; Ge, Can

    2016-07-01

    The rupture processes of the 2015 April 25 Gorkha earthquake and its strongest aftershock occurred on May 12 in Nepal are investigated by joint inversion of seismological and geodetic data. Synthetic test shows that the sedimentary layers in the source region play an important role in the rupture process inversion. Our optimized model of the mainshock shows that the rupture has a unilateral propagation pattern. The dominant mechanism is pure thrust with maximum slip of 5.8 m, the rupture scale extends ~ 60 km along dip and ~ 150 km along strike, and the largest static stress change is ~ 7.6 MPa. The total seismic moment is 7.87 × 1020 N m, equivalent to Mw 7.9. Most seismic moment was released within 80 s and the majority seismic moment was released at the first 40 s. The rupture propagated in main slip asperity with a velocity of ~ 3.0 km/s. The strong aftershock magnitude is about Mw 7.3, and the peak slip is about 5.0 m, close to the peak slip of the mainshock. Moreover, the slips of the mainshock and the aftershocks are in good complementary, suggesting a triggering relationship between them. Considering the strain accumulation, the Gorkha earthquake ruptured only part of the seismic gap alone, thus still poses high earthquake risk, especially in the west side of the mainshock rupture zone.

  8. Endoluminal Treatment of Ruptured Abdominal Aortic Aneurysm with Small Intestinal Submucosa Sandwich Endografts: A Pilot Study in Sheep

    SciTech Connect

    Yamada, Katsuyuki; Pavcnik, Dusan; Uchida, Barry T.; Timmermans, Hans A.; Corless, Christopher L.; Yin, Qiang; Yamakado, Koichiro; Wha Park, Joong; Roesch, Josef; Keller, Frederick S.; Sato, Morio; Yamada, Ryusaku

    2001-03-15

    Purpose: To evaluate efficacy of small intestinal submucosa (SIS) Sandwich endografts for the treatment of acute rupture of abdominal aortic aneurysms (AAA) and to explore the short-term reaction of the aorta to this material.Methods: In eight adult sheep, an infrarenal AAA was created transluminally by dilation of a short Palmaz stent. In six sheep, the aneurysm was then ruptured by overdilation of the stent with a large angioplasty balloon. Two sheep with AAAs that were not ruptured served as controls. A SIS Sandwich endograft, consisting of a Z stent frame with 5 bodies and covered inside and out with SIS, was used to exclude the ruptured and non-ruptured AAAs. Follow-up aortography was done immediately after the procedure and before sacrifice at 4, 8, or 12 weeks. Autopsy and histologic studies followed.Results: Endograft placement was successful in all eight sheep. Both ruptured and non-ruptured AAAs were successfully excluded. Three animals with AAA rupture developed hind leg paralysis due to compromise of the arterial supply to the lower spinal cord and were sacrificed 1 day after the procedure. In five animals, three with rupture and two controls, follow-up aortograms revealed no aortic stenoses and no perigraft leaks. Gross and histologic studies revealed incorporation of the endografts into the aortic wall with replacement of SIS by dense neointima that was completely endothelialized in areas where the endograft was in direct contact with the aortic wall. In central portions of the endograft, in contact with the thrombosed aneurysm, endothelialization was incomplete even at 12 weeks.Conclusion: The SIS Sandwich endografts effectively excluded simple AAAs and ruptured AAAs. They were rapidly incorporated into the aortic wall. A detailed long-term study is warranted.

  9. [Uterine scar after caeserean section- predicting the risk of uterine rupture and decision on the way of delivery].

    PubMed

    Tzankova, M; Nikolov, A; Pirnareva, E

    2014-01-01

    The Cesarean section rate in University Maternity Hospital 'Maichin dom' is 46 to 48%. The rate of repeated Cesarean section is also increasing. However there is an increasing number of women wishing to deliver vaginally after having had a Cesarean section for their first baby. On the other hand, with postponing pregnancy, increasing number of woman nowadays experience surgeries on their uterus prior to giving birth. With regards to the above-mentioned, pregnancy in scarred uterus is a common thing. Examining the uterine scar gives valuable information for the risk of uterine rupture during pregnancy and the decision making on the safest way of delivery. The current article shows ultrasound pics of uterine scar in pregnant and non-pregnant uterus. Gives recommendations for the timing of the US examination and the reference range for thickness of the uterine scar (residual myometrial thickness) in the view of the risk of rupture and the safest way of delivery. All this information is based on the most recent clinical trials.

  10. Achilles Tendon Rupture

    PubMed Central

    Wertz, Jess; Galli, Melissa; Borchers, James R.

    2013-01-01

    Context: Achilles tendon (AT) rupture in athletes is increasing in incidence and accounts for one of the most devastating sports injuries because of the threat to alter or end a career. Despite the magnitude of this injury, reliable risk assessment has not been clearly defined, and prevention strategies have been limited. The purpose of this review is to identify potential intrinsic and extrinsic risk factors for AT rupture in aerial and ground athletes stated in the current literature. Evidence Acquisition: A MEDLINE search was conducted on AT rupture, or “injury” and “risk factors” and “athletes” from 1980 to 2011. Emphasis was placed on epidemiology, etiology, and review articles focusing on the risk for lower extremity injury in runners and gymnasts. Thirty articles were reviewed, and 22 were included in this assessment. Results: Aerial and ground athletes share many intrinsic risk factors for AT rupture, including overuse and degeneration of the tendon as well as anatomical variations that mechanically put an athlete at risk. Older athletes, athletes atypical in size for their sport, high tensile loads, leg dominance, and fatigue also may increase risk. Aerial athletes tend to have more extrinsic factors that play a role in this injury due to the varying landing surfaces from heights and technical maneuvers performed at various skill levels. Conclusion: Risk assessment for AT rupture in aerial and ground athletes is multivariable and difficult in terms of developing prevention strategies. Quantitative measures of individual risk factors may help identify major contributors to injury. PMID:24427410

  11. Genetic analysis of abdominal aortic aneurysms (AAA)

    SciTech Connect

    St. Jean, P.L.; Hart, B.K.; Zhang, X.C.

    1994-09-01

    The association between AAA and gender, smoking (SM), hypertension (HTN) and inguinal herniation (IH) was examined in 141 AAA probands and 139 of their 1st degree relatives with aortic exam (36 affected, 103 unaffected). There was no significant difference between age at diagnosis of affecteds and age at exam of unaffecteds. Of 181 males, 142 had AAA; of 99 females, 35 had AAA. Using log-linear modeling AAA was significantly associated at the 5% level with gender, SM and HTN but not IH. The association of AAA with SM and HTN held when males and females were analyzed separately. HTN was -1.5 times more common in both affected males and females, while SM was 1.5 and 2 times more common in affected males and females, respectively. Tests of association and linkage analyses were performed with relevant candidate genes: 3 COL3A1 polymorphisms (C/T, ALA/THR, AvaII), 2 ELN polymorphisms (SER/GLY, (CA)n), FBN1(TAAA)n, 2 APOB polymorphisms (Xbal,Ins/Del), CLB4B (CA)n, PI and markers D1S243 (CA)n, HPR (CA)n and MFD23(CA)n. The loci were genotyped in > 100 AAA probands and > 95 normal controls. No statistically significant evidence of association at the 5% level was obtained for any of the loci using chi-square test of association. 28 families with 2 or more affecteds were analyzed using the affected pedigree member method (APM) and lod-score analyses. There was no evidence for linkage with any loci using APM. Lod-score analysis under an autosomal recessive model resulted in excluding linkage (lod score < -2) of all loci to AAA at {theta}=0.0. Under an autosomal dominant model, linkage was excluded at {theta}=0.0 to ELN, APOB, CLG4B, D1S243, HPR and MFD23. The various genes previously proposed in AAA pathogenesis are neither associated nor casually related in our study population.

  12. Pathophysiology of AAA: heredity vs environment.

    PubMed

    Björck, Martin; Wanhainen, Anders

    2013-01-01

    Abdominal aortic aneurysm (AAA) has a complex pathophysiology, in which both environmental and genetic factors play important roles, the most important being smoking. The recently reported falling prevalence rates of AAA in northern Europe and Australia/New Zeeland are largely explained by healthier smoking habits. Dietary factors and obesity, in particular abdominal obesity, are also of importance. A family history of AAA among first-degree relatives is present in approximately 13% of incident cases. The probability that a monozygotic twin of a person with an AAA has the disease is 24%, 71 times higher than that for a monozygotic twin of a person without AAA. Approximately 1000 SNPs in 100 candidate genes have been studied, and three genome-wide association studies were published, identifying different diverse weak associations. An example of interaction between environmental and genetic factors is the effect of cholesterol, where genetic and dietary factors affect levels of both HDL and LDL. True epigenetic studies have not yet been published.

  13. Differentiation, Self-Other Representations, and Rupture-Repair Processes: Predicting Child Maltreatment Risk

    ERIC Educational Resources Information Center

    Skowron, Elizabeth A.; Kozlowski, JoEllen M.; Pincus, Aaron L.

    2010-01-01

    This set of studies was designed to examine the relational underpinnings of child abuse potential in a sample of 51 urban families. In Study 1, lower maternal differentiation of self--most notably, greater emotional reactivity and greater emotional cutoff--along with self-attacking introjects distinguished mothers at higher risk (vs. lower risk)…

  14. Rupture disc

    DOEpatents

    Newton, Robert G.

    1977-01-01

    The intermediate heat transport system for a sodium-cooled fast breeder reactor includes a device for rapidly draining the sodium therefrom should a sodium-water reaction occur within the system. This device includes a rupturable member in a drain line in the system and means for cutting a large opening therein and for positively removing the sheared-out portion from the opening cut in the rupturable member. According to the preferred embodiment of the invention the rupturable member includes a solid head seated in the end of the drain line having a rim extending peripherally therearound, the rim being clamped against the end of the drain line by a clamp ring having an interior shearing edge, the bottom of the rupturable member being convex and extending into the drain line. Means are provided to draw the rupturable member away from the drain line against the shearing edge to clear the drain line for outflow of sodium therethrough.

  15. Geometrical factors influencing the hemodynamic behavior of the AAA stent grafts: essentials for the clinician.

    PubMed

    Georgakarakos, Efstratios; Argyriou, Christos; Schoretsanitis, Nikolaos; Ioannou, Chris V; Kontopodis, Nikolaos; Morgan, Robert; Tsetis, Dimitrios

    2014-12-01

    Endovascular aneurysm repair (EVAR) is considered to be the treatment of choice for abdominal aortic aneurysms (AAA). Despite the initial technical success, EVAR is amenable to early and late complications, among which the migration of the endograft (EG) with subsequent proximal endoleak (Type Ia) leads to repressurization of the AAA sac, exposure to excessive wall stress, and, hence, to potential rupture. This article discusses the influence that certain geometrical factors, such as neck angulation, iliac bifurcation, EG curvature, neck-to-iliac diameter, and length ratios, as well as iliac limbs configuration can exert on the hemodynamic behavior of the EGs. The information provided could help both clinicians and EG manufacturers towards further development and improvement of EG designs and better operational planning. PMID:24938906

  16. Sequence analysis of the AAA protein family.

    PubMed Central

    Beyer, A.

    1997-01-01

    The AAA protein family, a recently recognized group of Walker-type ATPases, has been subjected to an extensive sequence analysis. Multiple sequence alignments revealed the existence of a region of sequence similarity, the so-called AAA cassette. The borders of this cassette were localized and within it, three boxes of a high degree of conservation were identified. Two of these boxes could be assigned to substantial parts of the ATP binding site (namely, to Walker motifs A and B); the third may be a portion of the catalytic center. Phylogenetic trees were calculated to obtain insights into the evolutionary history of the family. Subfamilies with varying degrees of intra-relatedness could be discriminated; these relationships are also supported by analysis of sequences outside the canonical AAA boxes: within the cassette are regions that are strongly conserved within each subfamily, whereas little or even no similarity between different subfamilies can be observed. These regions are well suited to define fingerprints for subfamilies. A secondary structure prediction utilizing all available sequence information was performed and the result was fitted to the general 3D structure of a Walker A/GTPase. The agreement was unexpectedly high and strongly supports the conclusion that the AAA family belongs to the Walker superfamily of A/GTPases. PMID:9336829

  17. 26 CFR 1.1368-2 - Accumulated adjustments account (AAA).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 11 2010-04-01 2010-04-01 true Accumulated adjustments account (AAA). 1.1368-2... adjustments account (AAA). (a) Accumulated adjustments account—(1) In general. The accumulated adjustments account is an account of the S corporation and is not apportioned among shareholders. The AAA is...

  18. AAA-DDD triple hydrogen bond complexes.

    PubMed

    Blight, Barry A; Camara-Campos, Amaya; Djurdjevic, Smilja; Kaller, Martin; Leigh, David A; McMillan, Fiona M; McNab, Hamish; Slawin, Alexandra M Z

    2009-10-01

    Experiment and theory both suggest that the AAA-DDD pattern of hydrogen bond acceptors (A) and donors (D) is the arrangement of three contiguous hydrogen bonding centers that results in the strongest association between two species. Murray and Zimmerman prepared the first example of such a system (complex 3*2) and determined the lower limit of its association constant (K(a)) in CDCl(3) to be 10(5) M(-1) by (1)H NMR spectroscopy (Murray, T. J. and Zimmerman, S. C. J. Am. Chem. Soc. 1992, 114, 4010-4011). The first cationic AAA-DDD pair (3*4(+)) was described by Bell and Anslyn (Bell, D. A. and Anslyn, E. A. Tetrahedron 1995, 51, 7161-7172), with a K(a) > 5 x 10(5) M(-1) in CH(2)Cl(2) as determined by UV-vis spectroscopy. We were recently able to quantify the strength of a neutral AAA-DDD arrangement using a more chemically stable AAA-DDD system, 6*2, which has an association constant of 2 x 10(7) M(-1) in CH(2)Cl(2) (Djurdjevic, S., Leigh, D. A., McNab, H., Parsons, S., Teobaldi, G. and Zerbetto, F. J. Am. Chem. Soc. 2007, 129, 476-477). Here we report on further AA(A) and DDD partners, together with the first precise measurement of the association constant of a cationic AAA-DDD species. Complex 6*10(+)[B(3,5-(CF(3))(2)C(6)H(3))(4)(-)] has a K(a) = 3 x 10(10) M(-1) at RT in CH(2)Cl(2), by far the most strongly bound triple hydrogen bonded system measured to date. The X-ray crystal structure of 6*10(+) with a BPh(4)(-) counteranion shows a planar array of three short (NH...N distances 1.95-2.15 A), parallel (but staggered rather than strictly linear; N-H...N angles 165.4-168.8 degrees), primary hydrogen bonds. These are apparently reinforced, as theory predicts, by close electrostatic interactions (NH-*-N distances 2.78-3.29 A) between each proton and the acceptor atoms of the adjacent primary hydrogen bonds.

  19. Endovascular Treatment of Ruptured Abdominal Aortic Aneurysm with Aortocaval Fistula

    SciTech Connect

    Guzzardi, Giuseppe Fossaceca, Rita; Divenuto, Ignazio; Musiani, Antonello; Brustia, Piero; Carriero, Alessandro

    2010-08-15

    Aortocaval fistula (ACF) is a rare complication of abdominal aortic aneurysm (AAA). We report the endovascular repair of an AAA rupture into the inferior vena cava. A 78-year-old woman was admitted to our hospital for acute hypotension. She presented with a pulsatile abdominal mass and became rapidly anuric. Abdominal computed tomography (CT) showed an AAA rupture into the inferior vena cava. The features of the AAA made it suitable for endovascular repair. To prevent pulmonary embolism caused by the presence of sac thrombosis near the vena cava lumen, a temporary vena cava filter was deployed before the procedure. A bifurcated stent-graft was placed with the patient under local anaesthesia, and the AAA was successfully treated. A transient type II endoleak was detected on CT 3 days after endograft placement. At routine follow-up 6 and 12 months after the procedure, the patient was in good clinical condition, and the type II endoleak had sealed completely. Endovascular treatment offers an attractive therapeutic alternative to open repair in case of ACF; however, only small numbers of patients have been treated, and long-term follow-up interval is lacking.

  20. Indications for and outcome of open AAA repair in the endovascular era.

    PubMed

    Wieker, Carola M; Spazier, Max; Böckler, Dittmar

    2016-04-01

    The benefits, safety and efficacy of endovascular aortic aneurysm repair (EVAR) is well documented and intensively reported in multiple randomized trials and meta-analysis. Therefore, EVAR became the first choice of abdominal aortic aneurysms (AAA) treatment in almost 70-100% of patients. Consecutively, open repair (OR) is performed less frequently in morphologically preselected patients. Anatomical condition remains the most important factor for indication for OR. Especially unfavorable intrarenal landing zone based on difficult neck anatomy like very short neck or excessive neck angulation is still the most predictive factor. Furthermore, patients presenting additional iliac aneurysms, aortoiliac occlusive disease or variations of renal arteries are recommended for OR. Randomized trials like EVAR 1, DREAM and OVER from the year 2004/2005 and 2009 showed lower 30-day mortality rates in EVAR compared to OR. However, the late mortality rates after two years became equal in both treatment options. Furthermore, reinterventions after EVAR occur more frequently than after OR. Analysis from our own data showed a higher 30-day mortality in the patients who underwent OR in the endovascular era (15% vs. 2.5%), however the number of emergency open AAA repair because of ruptured aneurysms was much higher in the endovascular era (32.5% vs. 5%). In conclusion, treatment of AAA has changed in the past decade. Nevertheless OR of AAA still remains as a safe and durable method in experienced surgeons, even in the endovascular era. High volume centres are needed to offer the best patients' treatment providing the best postoperative outcome. Therefore OR must remain a part of fellowship training in the future. To decide the best treatment option many facts like patients' fitness and preference or finally the anatomic suitability for endovascular repair have to be considered. PMID:26822580

  1. Integrated Control of Axonemal Dynein AAA+ Motors

    PubMed Central

    King, Stephen M.

    2012-01-01

    Axonemal dyneins are AAA+ enzymes that convert ATP hydrolysis to mechanical work. This leads to the sliding of doublet microtubules with respect to each other and ultimately the generation of ciliary/flagellar beating. However, in order for useful work to be generated, the action of individual dynein motors must be precisely controlled. In addition, cells modulate the motility of these organelles through a variety of second messenger systems and these signals too must be integrated by the dynein motors to yield an appropriate output. This review describes the current status of efforts to understand dynein control mechanisms and their connectivity focusing mainly on studies of the outer dynein arm from axonemes of the unicellular biflagellate green alga Chlamydomonas. PMID:22406539

  2. AAAS Communicating Science Program: Reflections on Evaluation

    NASA Astrophysics Data System (ADS)

    Braha, J.

    2015-12-01

    The AAAS Center for Public Engagement (Center) with science builds capacity for scientists to engage public audiences by fostering collaboration among natural or physical scientists, communication researchers, and public engagement practitioners. The recently launched Leshner Leadership Institute empowers cohorts of mid-career scientists to lead public engagement by supporting their networks of scientists, researchers, and practitioners. The Center works closely with social scientists whose research addresses science communication and public engagement with science to ensure that the Communicating Science training program builds on empirical evidence to inform best practices. Researchers ( Besley, Dudo, & Storkdieck 2015) have helped Center staff and an external evaluator develop pan instrument that measures progress towards goals that are suggested by the researcher, including internal efficacy (increasing scientists' communication skills and confidence in their ability to engage with the public) and external efficacy (scientists' confidence in engagement methods). Evaluation results from one year of the Communicating Science program suggest that the model of training yields positive results that support scientists in the area that should lead to greater engagement. This talk will explore the model for training, which provides a context for strategic communication, as well as the practical factors, such as time, access to public engagement practitioners, and technical skill, that seems to contribute to increased willingness to engage with public audiences. The evaluation program results suggest willingness by training participants to engage directly or to take preliminary steps towards engagement. In the evaluation results, 38% of trained scientists reported time as a barrier to engagement; 35% reported concern that engagement would distract from their work as a barrier. AAAS works to improve practitioner-researcher-scientist networks to overcome such barriers.

  3. An Experimental and Numerical Comparison of the Rupture Locations of an Abdominal Aortic Aneurysm

    PubMed Central

    Doyle, Barry J.; Corbett, Timothy J.; Callanan, Anthony; Walsh, Michael T.; Vorp, David A.; McGloughlin, Timothy M.

    2009-01-01

    Purpose: To identify the rupture locations of idealized physical models of abdominal aortic aneurysm (AAA) using an in-vitro setup and to compare the findings to those predicted numerically. Methods: Five idealized AAAs were manufactured using Sylgard 184 silicone rubber, which had been mechanically characterized from tensile tests, tear tests, and finite element analysis. The models were then inflated to the point of rupture and recorded using a high-speed camera. Numerical modeling attempted to confirm these rupture locations. Regional variations in wall thickness of the silicone models was also quantified and applied to numerical models. Results: Four of the 5 models tested ruptured at inflection points in the proximal and distal regions of the aneurysm sac and not at regions of maximum diameter. These findings agree with high stress regions computed numerically. Wall stress appears to be independent of wall thickness, with high stress occurring at regions of inflection regardless of wall thickness variations. Conclusion: According to these experimental and numerical findings, AAAs experience higher stresses at regions of inflection compared to regions of maximum diameter. Ruptures of the idealized silicone models occurred predominantly at the inflection points, as numerically predicted. Regions of inflection can be easily identified from basic 3-dimensional reconstruction; as ruptures appear to occur at inflection points, these findings may provide a useful insight into the clinical significance of inflection regions. This approach will be applied to patient-specific models in a future study. PMID:19642790

  4. Morphological State as a Predictor for Reintervention and Mortality After EVAR for AAA

    SciTech Connect

    Ohrlander, Tomas; Dencker, Magnus; Acosta, Stefan

    2012-10-15

    Purpose: This study was designed to assess aorto-iliac morphological characteristics in relation to reintervention and all-cause long-term mortality in patients undergoing standard EVAR for infrarenal AAA. Methods: Patients treated with EVAR (Zenith{sup Registered-Sign} Stentgrafts, Cook) between May 1998 and February 2006 were prospectively enrolled in a computerized database where comorbidities and preoperative aneurysm morphology were entered. Reinterventions and mortality were checked until December 1, 2010. Median follow-up time was 68 months. Results: A total of 304 patients were included, of which 86% were men. Median age was 74 years. The reintervention rate was 23.4% (71/304). A greater diameter of the common iliac artery (p = 0.037; hazard ratio (HR) 1.037 [1.002-1.073]) was an independent factor for an increased number of reinterventions. The 30-day mortality rate was 3.0% (9/304). Aneurysm-related deaths due to AAA occurred in 4.9% (15/304). Five patients died due to a concomitant ruptured thoracic aortic aneurysm. The mortality until end of follow-up was 54.3% (165/304). The proportion of deaths caused by vascular diseases was 61.6%. The severity of angulation of the iliac arteries (p = 0.014; HR 1.018 [95% confidence interval (CI) 1.004-1.033]) and anemia (p = 0.044; HR 2.79 [95% CI 1.029-7.556]) remained as independent factors associated with all-cause long-term mortality. The crude reintervention-free survival rate at 1, 3, and 5 years was 84.5%, 64.8%, and 51.6%, respectively. Conclusions: The initial aorto-iliac morphological state in patients scheduled for standard EVAR for AAA seems to be strongly related to the need for reinterventions and long-term mortality.

  5. Fundamental Characteristics of AAA+ Protein Family Structure and Function

    PubMed Central

    2016-01-01

    Many complex cellular events depend on multiprotein complexes known as molecular machines to efficiently couple the energy derived from adenosine triphosphate hydrolysis to the generation of mechanical force. Members of the AAA+ ATPase superfamily (ATPases Associated with various cellular Activities) are critical components of many molecular machines. AAA+ proteins are defined by conserved modules that precisely position the active site elements of two adjacent subunits to catalyze ATP hydrolysis. In many cases, AAA+ proteins form a ring structure that translocates a polymeric substrate through the central channel using specialized loops that project into the central channel. We discuss the major features of AAA+ protein structure and function with an emphasis on pivotal aspects elucidated with archaeal proteins. PMID:27703410

  6. Spontaneous rupture of uterine leiomyoma during labour.

    PubMed

    Ramskill, Nikki; Hameed, Aisha; Beebeejaun, Yusuf

    2014-09-08

    Uterine rupture in labour requires an emergency caesarean section. In women with a uterine scar, either from gynaecological surgery or from a previous caesarean section, it is well documented that the risk of rupture is higher than in those without. Spontaneous uterine rupture in a uterus with fibroids during pregnancy or labour is extremely rare. We present a case of a 33-year-old, unbooked pregnant woman from Nigeria who had a uterine rupture secondary to fibroids. She required an emergency caesarean section in labour. The fibroids were not removed. Her baby was born alive and in good condition and she made an uneventful recovery.

  7. Spontaneous rupture of uterine leiomyoma during labour

    PubMed Central

    Ramskill, Nikki; Hameed, Aisha; Beebeejaun, Yusuf

    2014-01-01

    Uterine rupture in labour requires an emergency caesarean section. In women with a uterine scar, either from gynaecological surgery or from a previous caesarean section, it is well documented that the risk of rupture is higher than in those without. Spontaneous uterine rupture in a uterus with fibroids during pregnancy or labour is extremely rare. We present a case of a 33-year-old, unbooked pregnant woman from Nigeria who had a uterine rupture secondary to fibroids. She required an emergency caesarean section in labour. The fibroids were not removed. Her baby was born alive and in good condition and she made an uneventful recovery. PMID:25199188

  8. Inhibitors of the AAA+ Chaperone p97

    PubMed Central

    Chapman, Eli; Maksim, Nick; de la Cruz, Fabian; La Clair, James J.

    2015-01-01

    It is remarkable that a pathway as ubiquitous as protein quality control can be targeted to treat cancer. Bortezomib, an inhibitor of the proteasome, was first approved by the US Food and Drug Administration (FDA) more than 10 years ago to treat refractory myeloma and later extended to lymphoma. Its use has increased the survival rate of myeloma patients by as much as three years. This success was followed with the recent accelerated approval of the natural product derived proteasome inhibitor carfilzomib (Kyprolis®), which is used to treat patients with bortezomib-resistant multiple myeloma. The success of these two drugs has validated protein quality control as a viable target to fight select cancers, but begs the question why are proteasome inhibitors limited to lymphoma and myeloma? More recently, these limitations have encouraged the search for additional targets within the protein quality control system that might offer heightened cancer cell specificity, enhanced clinical utility, a lower rate of resistance, reduced toxicity, and mitigated side effects. One promising target is p97, an ATPase associated with various cellular activities (AAA+) chaperone. p97 figures prominently in protein quality control as well as serving a variety of other cellular functions associated with cancer. More than a decade ago, it was determined that up-regulation of p97 in many forms of cancer correlates with a poor clinical outcome. Since these initial discoveries, a mechanistic explanation for this observation has been partially illuminated, but details are lacking. Understandably, given this clinical correlation, myriad roles within the cell, and its importance in protein quality control, p97 has emerged as a potential therapeutic target. This review provides an overview of efforts towards the discovery of small molecule inhibitors of p97, offering a synopsis of efforts that parallel the excellent reviews that currently exist on p97 structure, function, and physiology. PMID

  9. Quadriceps and patellar tendon rupture.

    PubMed

    Ramseier, L E; Werner, C M L; Heinzelmann, M

    2006-06-01

    Ruptures of the patellar and/or quadriceps tendon are rare injuries that require immediate repair to re-establish knee extensor continuity and to allow early motion. We evaluated 36 consecutive patients with quadriceps or patellar tendon rupture between 1993 and 2000. There were 37 primary ruptures, 3 reruptures, 21 quadriceps and 19 patellar tendon ruptures. Follow up examination (>24 months postoperatively) included the patient's history, assessment of risk factors, clinical examination of both knees, isometric muscle strength measurements and three specific knee scores, Hospital for Special Surgery Score, Knee Society Score and Turba Score, and a short form SF-36. We evaluated 29 patients (26 men) with 33 ruptures (16 patellar tendon, 17 quadriceps tendon). Seven patients were lost to follow up. We found no difference between the range of motion and muscle strength when the injured leg was compared to the non-injured leg. Risk factors did not influence the four scores, patient satisfaction, pain, muscle strength or range of motion. Multiple injured patients had a significant reduction in muscle strength and circumference, however patient satisfaction did not differ to the non-multiple injured patient group.

  10. Prediction of in-hospital mortality after ruptured abdominal aortic aneurysm repair using an artificial neural network

    PubMed Central

    Wise, Eric S.; Hocking, Kyle M.; Brophy, Colleen M.

    2015-01-01

    Objective Ruptured abdominal aortic aneurysm (rAAA) carries a high mortality rate, even with prompt transfer to a medical center. An artificial neural network (ANN) is a computational model which improves predictive ability via pattern recognition, while continually adapting to new input data. The goal of this study was to effectively use ANN modeling to provide vascular surgeons a discriminant adjunct to assess the likelihood of in-hospital mortality on a pending rAAA admission using easily obtainable patient information from the field. Methods One-hundred and twenty-five of 332 total patients from a single-institution from 1998–2013 who had attempted rAAA repair were reviewed for preoperative factors associated with in-hospital mortality. One-hundred and eight patients received an open operation, and 17 patients received endovascular repair. Five variables were found significant upon multivariate analysis (P < .05), and four of these five: preoperative shock, loss of consciousness, cardiac arrest and age were modeled via multiple logistic regression and an ANN. These predictive models were compared against the Glasgow Aneurysm Score (GAS). All models were assessed by generation of receiver operating characteristic curves and Actual vs. Predicted outcomes plots, with area under the curve (AUC) and Pearson r2 value as the primary measures of discriminant ability. Results Of the 125 patients, 53 (42%) did not survive to discharge. Five preoperative factors were significant (P < .05) independent predictors of in-hospital mortality in multivariate analysis: advanced age, renal disease, loss of consciousness, cardiac arrest and shock, though renal disease was excluded from the models. The sequential accumulation of zero to four of these risk factors progressively increased overall mortality rate, from 11% to 16% to 44% to 76% to 89% (Age ≥ 70 considered a risk factor). Algorithms derived from multiple logistic regression, ANN and GAS models generated AUC values of

  11. Risk Factors and Epidemiology of Coccidioidomycosis Demonstrated by a Case of Spontaneous Pulmonary Rupture of Cavitary Coccidioidomycosis

    PubMed Central

    Yau, Amy A.

    2016-01-01

    A 31-year-old Hispanic male with no medical history was admitted for fevers, pleurisy, and cough after recent oral surgery and completing demolition and construction work in Juarez, Mexico. Imaging showed a 4.4 cm cavitary lesion and bilateral tree-in-bud opacities. Initial suspicion of bacterial infection confirmed with clinical improvement on culture specific antibiotics, but after discharge he returned with progression of symptoms and new dyspnea. Radiograph showed a pyopneumothorax. Chest computed tomography after thoracostomy showed worsening infiltrates and another cavitary lesion. Symptoms persisted despite addition of broad spectrum antibiotics. Surgical repair for persistent air leak was required. Weeks after discharge, cultures and serologies returned positive for Coccidioidomycosis immitis. Coccidioides species cause up to 30% of community-acquired pneumonia and incidental cavitary lesions in endemic regions. Symptoms are nonspecific yet usually involve fatigue, cough, and pleurisy. Most hosts have spontaneous resolution; however, certain demographics such as Hispanics and diabetics, later diagnosed in our patient, have higher morbidity. As seen with our patient, cavitary rupture and bronchopleural fistulas are rare occurring in 2.6% of cavitary lesions. High suspicion based on symptoms and host demographics is important to assist in early diagnosis and treatment to avoid and treat this common pathogen's presentations. PMID:26904326

  12. Chronic Contained Rupture of an Abdominal Aortic Aneurysm: From Diagnosis to Endovascular Resolution

    SciTech Connect

    Gandini, Roberto Chiocchi, Marcello; Maresca, Luciano; Pipitone, Vincenzo; Messina, Massimo; Simonetti, Giovanni

    2008-07-15

    A male patient, 69 years old, presented with fever, leucocytosis, and persistent low back pain; he also had an abdominal aortic aneurysm (AAA), as previously diagnosed by Doppler UltraSound (US), and was admitted to our hospital. On multislice computed tomography (msCT), a large abdominal mass having no definite border and involving the aorta and both of the psoas muscles was seen. This mass involved the forth-lumbar vertebra with lysis, thus simulating AAA rupture into a paraspinal collection; it was initially considered a paraspinal abscess. After magnetic resonance imaging examination and culture of the fluid aspirated from the mass, no infective organisms were found; therefore, a diagnosisof chronically contained AAA rupture was made, and an aortic endoprosthesis was subsequently implanted. The patient was discharged with decreased lumbar pain. At 12-month follow-up, no evidence of leakage was observed. To our knowledge, this is the first case of endoprosthesis implantation in a patient, who was a poor candidate for surgical intervention due to renal failure, leucocytosis and high fever, having a chronically contained AAA ruptured simulatingspodilodiscitis abscess. Appropriate diagnosis and therapy resolved potentially crippling pathology and avoided surgical graft-related complications.

  13. Rupture and bleeding secondary to renal infarction in a patient with an abdominal aortic aneurysm.

    PubMed

    Hiraoka, Toshifumi; Mukai, Shogo; Obata, Shogo; Morimoto, Hironobu; Uchida, Hiroaki; Yamane, Yoshitaka

    2014-01-01

    A 57-year-old man had been followed up for severe left ventricular dysfunction after acute myocardial infarction with a left ventricular thrombus. He had been treated with anticoagulant and antiplatelet therapy and was admitted to our hospital because of abdominal pain and shock. He had no prior episode of trauma. The electrocardiogram (ECG) showed no changes compared with the previous ECG. Enhanced abdominal computed tomography (CT) showed a retroperitoneal hematoma around an abdominal aortic aneurysm (AAA) and the right kidney. We suspected rupture of AAA or the right kidney, and we performed AAA replacement with a Y-shaped graft and nephrectomy of the right kidney. Pathological examination revealed hemorrhagic infarction of the lower part of the right kidney, with hemorrhage and rupture at the center of the infarct. In our case, enhanced CT showed extravasation from the lower part of the right kidney. In addition, postoperative echocardiography showed that the left ventricular thrombus had disappeared. We report a case of rupture and bleeding secondary to renal infarction in a patient with an AAA.

  14. [Simultaneous rupture of a patellar tendon and contralateral quadriceps tendon].

    PubMed

    Horas, U; Ernst, S; Meyer, C; Halbsguth, A; Herbst, U

    2006-09-01

    The simultaneous bilateral rupture of the quadriceps tendon is a rare injury; only occasional reports exist about the bilateral simultaneous rupture of the patellar tendon. Degenerative changes of the tendon due to drugs or diseases lead to the rupture. We describe two cases of simultaneous rupture of the patellar and contralateral quadriceps tendons; only one patient had special risks. We report the management of therapy and the functional results using the Lysholm score and Knee Rating Scale.

  15. Role of AAA(+)-proteins in peroxisome biogenesis and function.

    PubMed

    Grimm, Immanuel; Erdmann, Ralf; Girzalsky, Wolfgang

    2016-05-01

    Mutations in the PEX1 gene, which encodes a protein required for peroxisome biogenesis, are the most common cause of the Zellweger spectrum diseases. The recognition that Pex1p shares a conserved ATP-binding domain with p97 and NSF led to the discovery of the extended family of AAA+-type ATPases. So far, four AAA+-type ATPases are related to peroxisome function. Pex6p functions together with Pex1p in peroxisome biogenesis, ATAD1/Msp1p plays a role in membrane protein targeting and a member of the Lon-family of proteases is associated with peroxisomal quality control. This review summarizes the current knowledge on the AAA+-proteins involved in peroxisome biogenesis and function.

  16. Impact on Risk of Data-Constrained Inferences of the Variability of the Recurrence of Ground-Rupturing Earthquakes

    NASA Astrophysics Data System (ADS)

    Fitzenz, D. D.; Nyst, M.

    2015-12-01

    The concept of the time-dependence of the occurrence of large events on a given geologic structure emerged from the elastic rebound theory of Reid (1910). Models were developed or chosen to account for it. For the most part, those models need the long-term recurrence time, a measure of the allowed short-term variability of the recurrence time (e.g., the coefficient of variation CoV), and are applied in conjunction with the time since the last event whenever possible. Geologic estimates of the long-term have been used for a long time. CoV values, on the other hand, were first assigned usually through a logic-tree approach featuring a preferred value and one or two alternative values. Later-on a generic CoV value was determined on a global dataset (Elssworth et al 1999). It is only recently that earthquake timing data at a site have become numerous and high resolution enough to warrant data-constrained estimates of CoV. Whereas a logic-tree approach, meant to formulate epistemic uncertainties, leads to different (weighted) estimates of risk metrics, an approach in which the model parameters (such as CoV) are constrained by earthquake data presents a different view of risk uncertainty. Indeed, when the data are not informative, the resulting hazard rate curve vs. time since last event is flat. As information becomes integrated in the model, if the fault indeed exhibits a time-dependent behavior, the hazard rate curve shows variability with elapsed time. In terms of risk, a flat hazard rate translates into a time-independent view of risk whereas a time-varying hazard rate results in short-term variations in risk estimates. In this view, the hazard rate at a given time does not have an uncertainty associated to it (in the same way that a probability density function does not have an uncertainty associated to it). Its value integrates all the uncertainties coming from model and data. This approach allows a seamless update of risk metrics as new earthquake data becomes

  17. Intermittent pneumatic compression reduces the risk of deep vein thrombosis during post-operative lower limb immobilisation: a prospective randomised trial of acute ruptures of the Achilles tendon.

    PubMed

    Domeij-Arverud, E; Labruto, F; Latifi, A; Nilsson, G; Edman, G; Ackermann, P W

    2015-05-01

    Deep vein thrombosis is a common complication of immobilising the lower limb after surgery. We hypothesised that intermittent pneumatic compression (IPC) therapy in outpatients who had undergone surgical repair of acute ruptures of the Achilles tendon could reduce the incidence of this problem. A total of 150 patients who had undergone surgical repair of the Achilles tendon were randomised to either treatment with IPC for six hours per day (n = 74) under an orthosis or treatment as usual (n = 74) in a plaster cast without IPC. At two weeks post-operatively, the incidence of deep vein thrombosis was assessed using blinded, double-reported compression duplex ultrasound. At this point, IPC was discontinued and all patients were immobilised in an orthosis for a further four weeks. At six weeks post-operatively, a second compression duplex ultrasound scan was performed. At two weeks, the incidence of deep vein thrombosis was 21% in the treated group and 37% in the control group (p = 0.042). Age over 39 years was found to be a strong risk factor for deep vein thrombosis (odds ratio (OR) = 4.84, 95% confidence interval (CI) 2.14 to 10.96). Treatment with IPC, corrected for age differences between groups, reduced the risk of deep vein thrombosis at the two-week point (OR = 2.60; 95% CI 1.15 to 5.91; p =0.022). At six weeks, the incidence of deep vein thrombosis was 52% in the treated group and 48% in the control group (OR 0.94, 95% CI 0.49 to 1.83). IPC appears to be an effective method of reducing the risk of deep vein thrombosis in the early stages of post-operative immobilisation of outpatients. Further research is necessary to elucidate whether it can confer similar benefits over longer periods of immobilisation and in a more heterogeneous group of patients.

  18. Glass rupture disk

    DOEpatents

    Glass, S. Jill; Nicolaysen, Scott D.; Beauchamp, Edwin K.

    2002-01-01

    A frangible rupture disk and mounting apparatus for use in blocking fluid flow, generally in a fluid conducting conduit such as a well casing, a well tubing string or other conduits within subterranean boreholes. The disk can also be utilized in above-surface pipes or tanks where temporary and controllable fluid blockage is required. The frangible rupture disk is made from a pre-stressed glass with controllable rupture properties wherein the strength distribution has a standard deviation less than approximately 5% from the mean strength. The frangible rupture disk has controllable operating pressures and rupture pressures.

  19. Comparative Effectiveness of Endovascular versus Open Repair of Ruptured Abdominal Aortic Aneurysm in the Medicare Population

    PubMed Central

    Edwards, Samuel T.; Schermerhorn, Marc L.; O’Malley, A. James; Bensley, Rodney P.; Hurks, Rob; Cotterill, Philip; Landon, Bruce E.

    2015-01-01

    Objectives Endovascular abdominal aortic aneurysm repair (EVAR) is increasingly used for emergent treatment of ruptured abdominal aortic aneurysm (rAAA). We sought to compare the perioperative and long-term mortality, procedure-related complications and rates of re-intervention of EVAR versus open aortic repair of rAAA in Medicare beneficiaries. Methods We examined perioperative and long-term mortality and complications after EVAR or open aortic repair performed for rAAA in all traditional Medicare beneficiaries discharged from a US hospital from 2001–2008. Patients were propensity score matched on baseline demographics, coexisting conditions, admission source, and hospital volume of rAAA repair and sensitivity analyses were performed to evaluate the impact of bias that might have resulted from unmeasured confounders Results Of 10,998 patients with repaired rAAA, 1126 underwent EVAR and 9872 underwent open repair. Propensity score matching yielded 1099 patient pairs. The average age was 78 years, and 72.4% were male. Perioperative mortality for EVAR and open repair were 33.8% and 47.7% respectively (p<0.001) and this difference persisted for more than four years. EVAR patients had higher rates of AAA-related reinterventions when compared with open repair patients (endovascular reintervention at 36 months 10.9% vs 1.5%, p<0.001), whereas open patients had more laparotomy related complications (incisional hernia repair at 36 months 1.8% vs. 6.2% p<0.001, all surgical complications at 36 months 4.4% vs. 9.1%, p<0.001). Use of EVAR for rAAA has increased from 6% of cases in 2001 to 31% of cases in 2008, while over the same time period overall 30-day mortality for admission for rAAA regardless of treatment has decreased from 55.8% to 50.9%. Conclusions EVAR for rAAA is associated with lower perioperative and long term mortality in Medicare beneficiaries. Increasing adoption of EVAR for rAAA is associated with an overall decrease in mortality of patients hospitalized

  20. Ex-congressman Rush Holt to lead AAAS

    NASA Astrophysics Data System (ADS)

    Banks, Michael

    2015-01-01

    The particle physicist Rush Holt, who served in the US Congress for 15 years, has been named as the next chief executive of the American Association for the Advancement of Science (AAAS) - the non-profit US society that promotes public engagement with science and technology.

  1. The Adult Asperger Assessment (AAA): A Diagnostic Method

    ERIC Educational Resources Information Center

    Baron-Cohen, Simon; Wheelwright, Sally; Robinson, Janine; Woodbury-Smith, Marc

    2005-01-01

    At the present time there are a large number of adults who have "suspected" Asperger syndrome (AS). In this paper we describe a new instrument, the Adult Asperger Assessment (AAA), developed in our clinic for adults with AS. The need for a new instrument relevant to the diagnosis of AS in adulthood arises because existing instruments are designed…

  2. THE AAA3 DOMAIN OF CYTOPLASMIC DYNEIN ACTS AS A SWITCH TO FACILITATE MICROTUBULE RELEASE

    PubMed Central

    Dewitt, Mark A.; Cypranowska, Caroline A.; Cleary, Frank B.; Belyy, Vladislav; Yildiz, Ahmet

    2014-01-01

    Cytoplasmic dynein is an AAA+ motor responsible for intracellular cargo transport and force generation along microtubules (MTs). Unlike kinesin and myosin, dynein contains multiple ATPase subunits, with AAA1 serving as the primary catalytic site. ATPase activity at AAA3 is also essential for robust motility, but its role in dynein’s mechanochemical cycle remains unclear. Here, we introduced transient pauses in Saccharomyces cerevisiae dynein motility by using a slowly hydrolyzing ATP analog. Analysis of pausing behavior revealed that AAA3 hydrolyzes nucleotide an order of magnitude slower than AAA1 and the two sites do not coordinate. ATPase mutations to AAA3 abolish the ability of dynein to modulate MT release. Nucleotide hydrolysis at AAA3 lifts this “MT gate” to fast motility. These results suggest that AAA3 acts as a switch that repurposes cytoplasmic dynein for fast cargo transport and MT anchoring tasks in cells. PMID:25486306

  3. Self-Rupturing Hermetic Valve

    NASA Technical Reports Server (NTRS)

    Tucker, Curtis E., Jr.; Sherrit, Stewart

    2011-01-01

    For commercial, military, and aerospace applications, low-cost, small, reliable, and lightweight gas and liquid hermetically sealed valves with post initiation on/off capability are highly desirable for pressurized systems. Applications include remote fire suppression, single-use system-pressurization systems, spacecraft propellant systems, and in situ instruments. Current pyrotechnic- activated rupture disk hermetic valves were designed for physically larger systems and are heavy and integrate poorly with portable equipment, aircraft, and small spacecraft and instrument systems. Additionally, current pyrotechnically activated systems impart high g-force shock loads to surrounding components and structures, which increase the risk of damage and can require additional mitigation. The disclosed mechanism addresses the need for producing a hermetically sealed micro-isolation valve for low and high pressure for commercial, aerospace, and spacecraft applications. High-precision electrical discharge machining (EDM) parts allow for the machining of mated parts with gaps less than a thousandth of an inch. These high-precision parts are used to support against pressure and extrusion, a thin hermetically welded diaphragm. This diaphragm ruptures from a pressure differential when the support is removed and/or when the plunger is forced against the diaphragm. With the addition of conventional seals to the plunger and a two-way actuator, a derivative of this design would allow nonhermetic use as an on/off or metering valve after the initial rupturing of the hermetic sealing disk. In addition, in a single-use hermetically sealed isolation valve, the valve can be activated without the use of potential leak-inducing valve body penetrations. One implementation of this technology is a high-pressure, high-flow-rate rupture valve that is self-rupturing, which is advantageous for high-pressure applications such as gas isolation valves. Once initiated, this technology is self

  4. Molecularly Defined Nanostructures Based on a Novel AAA-DDD Triple Hydrogen-Bonding Motif.

    PubMed

    Papmeyer, Marcus; Vuilleumier, Clément A; Pavan, Giovanni M; Zhurov, Konstantin O; Severin, Kay

    2016-01-26

    A facile and flexible method for the synthesis of a new AAA-DDD triple hydrogen-bonding motif is described. Polytopic supramolecular building blocks with precisely oriented AAA and DDD groups are thus accessible in few steps. These building blocks were used for the assembly of large macrocycles featuring four AAA-DDD interactions and a macrobicyclic complex with a total of six AAA-DDD interactions.

  5. Inhibition of early AAA formation by aortic intraluminal pentagalloyl glucose (PGG) infusion in a novel porcine AAA model

    PubMed Central

    Kloster, Brian O.; Lund, Lars; Lindholt, Jes S.

    2016-01-01

    Background The vast majority of abdominal aortic aneurysms found in screening programs are small, and as no effective treatment exits, many will expand until surgery is indicated. Therefore, it remains intriguing to develop a safe and low cost treatment of these small aneurysms, that is able to prevent or delay their expansion. In this study, we investigated whether intraluminal delivered pentagalloyl glucose (PGG) can impair the early AAA development in a porcine model. Methods The infrarenal aorta was exposed in thirty pigs. Twenty underwent an elastase based AAA inducing procedure and ten of these received an additional intraluminal PGG infusion. The final 10 were sham operated and served as controls. Results All pigs who only had an elastase infusion developed macroscopically expanding AAAs. In pigs treated with an additional PGG infusion the growth rate of the AP-diameter rapidly returned to physiological values as seen in the control group. In the elastase group, histology revealed more or less complete resolution of the elastic lamellae in the media while they were more abundant, coherent and structurally organized in the PGG group. The control group displayed normal physiological growth and histology. Conclusion In our model, intraluminal delivered PGG is able to penetrate the aortic wall from the inside and impair the early AAA development by stabilizing the elastic lamellae and preserving their integrity. The principle holds a high clinical potential if it can be translated to human conditions, since it, if so, potentially could represent a new drug for stabilizing small abdominal aneurysms. PMID:27144001

  6. Endovascular Aneurysm Sealing for the Treatment of Ruptured Abdominal Aortic Aneurysms

    PubMed Central

    Brownrigg, Jack R. W.; Karthikesalingam, Alan; Patterson, Benjamin O.; Holt, Peter J. E.; Hinchliffe, Robert J.; Morgan, Robert A.; Loftus, Ian M.; Thompson, Matthew M.

    2015-01-01

    Purpose: To assess the feasibility and report preliminary results of ruptured abdominal aortic aneurysm (rAAA) repair with endovascular aneurysm sealing (EVAS), a novel therapeutic alternative whose feasibility has not been established in rAAAs due to the unknown effects of the rupture site on the ability to achieve sealing. Case Report: Between December 2013 and April 2014, 5 patients (median age 71 years, range 57–90; 3 men) with rAAAs were treated with the Nellix EVAS system at a single institution. Median aneurysm diameter was 70 mm (range 67–91). Aneurysm morphology in 4 of the 5 patients was noncompliant with instructions for use (IFU) for both EVAS and standard stent-grafts; the remaining patient was outside the IFU for standard stent-grafts but treated with EVAS under standard IFU for the Nellix system. Median Hardman index was 2 (range 0–3). Two patients died of multiorgan failure after re-laparotomy and intraoperative cardiac arrest, respectively. Among survivors, all devices were patent with no signs of endoleak or failed aneurysm sac sealing at 6 months (median follow-up 9.2 months). Conclusion: EVAS for the management of infrarenal rAAAs appears feasible. The use of EVAS in emergency repairs may broaden the selection criteria of the current endovascular strategy to include patients with more complex aneurysm morphology. PMID:25904491

  7. [Premature rupture of membranes and chorioamnionitis].

    PubMed

    Lopez Garcia, R

    1988-01-01

    , and congenital malformations. Neonatal sepsis occurs in about 5% of live births following premature rupture, but the rate triples after 24 hours, especially in premature infants. The rate of neonatal asphyxia also increases considerable after 24 hours. Congenital malformations, prolapse of the cord, and pelvic presentation are positively associated with premature rupture of membranes. If the decision is made to interrupt the pregnancy, it should be done between 12-24 hours after rupture because the risks of infection and respiratory difficulty are most balanced at that point. Vaginal deliveries should be preferred only if conditions are favorable for a prompt delivery. The gestational age, presence of infection, obstetric condition of the mother, and indication for hysterectomy are the most important points to consider i management of premature rupture.

  8. The relationship between macro- and micro-nutrients intake and risk of preterm premature rupture of membranes in pregnant women of Isfahan

    PubMed Central

    Hassanzadeh, Akbar; Paknahad, Zamzam; Khoigani, Masoomeh Goodarzi

    2016-01-01

    Background: Since preterm premature rupture of membranes (PPROM) is one of the most important complications of pregnancy and its relationship with nutrition status have not been surveyed comprehensively, we decided to study the relationship of maternal received nutrients (36 macro- and micro-nutrients) in three trimesters and PPROM which could be considered as a unique study. Materials and Methods: In this prospective cohort study, data was collected by filling a questionnaire through interviews with 620 pregnant women who had no parameters to affect pregnancy outcome. 48-hr dietary recalls were completed for eligible women at 11th–15th, 26th, 34th–37th weeks of gestation. Physical activity was also assessed using a standard questionnaire. Also pregnant mother's reproductive and demographic characteristic and supplementation are considered. Results: The mean value of received saturated fatty acids, polyunsaturated fatty acids and energy, in the first trimester (P < 0.001, P = 0.007, and P < 0.001 respectively), the mean values of calcium, sodium intake in the second trimester (P = 0.045, P = 0.006, and P = 0.004 respectively), Vitamins C, A (mg), β-carotene, cartenoids intake in the second trimester (P = 0.03, P = 0.001, P = 0.007, and P = 0.01 respectively), and higher Vitamin C intake during the first trimester (P = 0.02) was significantly greater among subjects with PPROM compared to the others. Conclusions: The mean value of mentioned received nutrients in subjects who experienced PPROM later in pregnancy was higher than the others, which is independent of demographic and reproductive characteristic, estimated physical activity, and supplementation. Therefore, these findings could be considered in the nutritional programming for pregnant women to manage the risk of PPROM. PMID:27713876

  9. Redo-EVAR After Surgical Repair in Ruptured Abdominal Aortic Aneurysm

    PubMed Central

    Bozok, Şahin; Ozan Karakişi, Sedat; Ergene, Şaban; Tufekçi, Nebiye; Ilhan, Gökhan; Karamustafa, Hakan

    2015-01-01

    Endovascular aneurysm repair (EVAR) is an adequate means for treating infrarenal abdominal aortic aneurysms (AAA). However, secondary interventions are required in approximately 15% to 20% of patients. The aim of this paper was to report our knowledge with stent grafts in secondary interventions after EVAR in a 73-year-old patient. One of the exceptional complications of EVAR are endoleaks which may lead to expansion of aneurysm and rupture if not repaired. PMID:26702349

  10. Can surgeons assess CT suitability for endovascular repair (EVAR) in ruptured abdominal aortic aneurysm? Implications for a ruptured EVAR trial.

    PubMed

    Rayt, Harjeet; Lambert, Kelly; Bown, Matthew; Fishwick, Guy; Morgan, Robert; McCarthy, Mark; London, Nick; Sayers, Robert

    2008-01-01

    The purpose of this study was to determine whether surgeons without formal radiological training are able to assess suitability of patients with ruptured abdominal aortic aneurysms (AAA) for EVAR. The CT scans of 20 patients with AAA were reviewed under timed conditions by six vascular surgeons. Twenty minutes was allocated per scan. They were asked to determine if each aneurysm would be treatable by EVAR in the emergency setting and, if so, to measure for device selection. The results were then compared with those of a vascular radiologist. Six surgeons agreed on the suitability of endovascular repair in 45% of cases (95% CI, 23.1-68.5%; 9/20 scans; kappa = 0.41 [p = 0.01]) and concurred with the radiologist in eight of these. Individually, agreement ranged from 13 to 16 of the 20 scans, 65-80% between surgeons. The kappa value for agreement between all the surgeons and the radiologist was 0.47 (p = 0.01, moderate agreement). For the individual surgeons, this ranged from 0.3 to 0.6 (p = 0.01). In conclusion, while overall agreement was moderate between the surgeons and the radiologist, it is clear that if surgeons are to assess patients for ruptured EVAR in the future, focused training of surgical trainees is required.

  11. Can Surgeons Assess CT Suitability for Endovascular Repair (EVAR) in Ruptured Abdominal Aortic Aneurysm? Implications for a Ruptured EVAR Trial

    SciTech Connect

    Rayt, Harjeet Lambert, Kelly; Bown, Matthew; Fishwick, Guy; Morgan, Robert; McCarthy, Mark; London, Nick; Sayers, Robert

    2008-09-15

    The purpose of this study was to determine whether surgeons without formal radiological training are able to assess suitability of patients with ruptured abdominal aortic aneurysms (AAA) for EVAR. The CT scans of 20 patients with AAA were reviewed under timed conditions by six vascular surgeons. Twenty minutes was allocated per scan. They were asked to determine if each aneurysm would be treatable by EVAR in the emergency setting and, if so, to measure for device selection. The results were then compared with those of a vascular radiologist. Six surgeons agreed on the suitability of endovascular repair in 45% of cases (95% CI, 23.1-68.5%; 9/20 scans; {kappa} = 0.41 [p = 0.01]) and concurred with the radiologist in eight of these. Individually, agreement ranged from 13 to 16 of the 20 scans, 65-80% between surgeons. The kappa value for agreement between all the surgeons and the radiologist was 0.47 (p = 0.01, moderate agreement). For the individual surgeons, this ranged from 0.3 to 0.6 (p = 0.01). In conclusion, while overall agreement was moderate between the surgeons and the radiologist, it is clear that if surgeons are to assess patients for ruptured EVAR in the future, focused training of surgical trainees is required.

  12. Chronic Tendonopathy as a Unique Cause of Non Traumatic Triceps Tendon Rupture in a (Risk Factors Free) Bodybuilder: A Case Report

    PubMed Central

    Mangano, Tony; Cerruti, Paola; Repetto, Ilaria; Trentini, Roberto; Giovale, Marcello; Franchin, Francesco

    2015-01-01

    Introduction: Distal triceps tendon rupture is an uncommon lesion rarely due to a non-traumatic mechanism. In these cases, the majority of patients show predisposing factors for tendon degeneration: underlying medical co-morbidities, previous systemic and locally injected corticosteroids and systemic anabolic steroids. A clear evidence for an etiopathogeneticroleforchronictendonopathy in triceps tendon rupture is sti 11 lacking. Case Report: We report the case of a rare non-traumatic complete rupture of the triceps tendon, at the olecranon insertion, occurring in a healthy male middle-aged non-professional bodybuilder. He presented to our attention with a five days history of weakness, swelling and pain at the left elbow, started after a snapping sound during a single arm triceps extension exercise. He was a healthy sportsman, no smoker and no drinker. He had suffered, in the two months before, of mild bilateral exercise-related elbow discomfort, never limiting his sport and daily activities. The man was treated by an early surgical repair. Histological analysis was conducted on intraoperative samples. The treatment allowed complete remission and return to sport practice without functional deficit. Conclusion: An overload-related chronic tendonopathy was identified as the unique factor with causal role in the determinism of the above described lesion. This case highlights, for the first time in literature, that just a chronic tendonopathy, in absence of any other predisposing condition, can lead to a non-traumatic complete triceps tendon rupture. PMID:27299023

  13. Genital Flora, Prolonged Rupture of the Membranes and the Risk of Early Onset Neonatal Septicemia in Qatif Central Hospital, Kingdom of Saudi Arabia.

    ERIC Educational Resources Information Center

    Srair, Hussain Abu; And Others

    1993-01-01

    Evaluated 108 mothers and their newborn babies for bacterial colonization and neonatal septicemia (NNS) after membranes had ruptured for 24 hours or more. Nearly 40% of the babies were already colonized at birth. The three most common bacteria isolated from the babies were Escherichia coli, Group B Streptococcus, and Streptococcus faecalis. (MDM)

  14. Does the A9285G Polymorphism in Collagen Type XII α1 Gene Associate with the Risk of Anterior Cruciate Ligament Ruptures?

    PubMed Central

    Ficek, K; Stepien-Slodkowska, M; Kaczmarczyk, M; Maciejewska-Karlowska, A; Sawczuk, M; Cholewinski, J; Leonska-Duniec, A; Zarebska, A; Cieszczyk, P; Zmijewski, P

    2014-01-01

    One of the most severe injuries sustained by athletes is rupture of the anterior cruciate ligament (ACL). Recent investigations suggest that a predisposition for ACL rupture may be the result of specific genetic sequence variants. In light of this, we decided to investigate whether the COL12A1 A9285G polymorphism was associated with ACL ruptures in Polish football players. We compared genotypic and allelic frequencies of the COL12A1 A9285G polymorphism in two groups of athletes: 91 male football players (23 ± 3 years) with surgically diagnosed primary ACL ruptures who qualified for ligament reconstruction (cases) and 143 apparently healthy, male football players of the same ethnicity, a similar age category, and a comparable level of exposure to ACL injury, who were without any self-reported history of ligament or tendon injury (controls). DNA samples extracted from the oral epithelial cells were genotyped by using a real-time polymerase chain reaction (Ri-Ti-PCR) method. The genotype distribution in the cases were not different from those in controls (p = 0.70). The frequency of the G allele was lower in the cases (18.1%) but not statistically significant (p = 0.40) when compared with controls (21.3%). Our results are in contradiction to the hypothesis that the COL12A1 A9285G polymorphism is associated with a predisposition for ACL injury. However, these conclusions should be supported with more experimental studies on COL12A1 polymorphisms. PMID:25741214

  15. Parsonage-Turner syndrome and a localised swelling around the extensor tendons of the hand: a clinical sign indicating increased risk of rupture of the tendon.

    PubMed

    Vedung, Torbjörn

    2012-10-01

    Two patients presented with intense pain in the shoulder followed by weakness and paralysis of muscles in the shoulder and arm, together with a peculiar swelling on the hand. The swelling seems to predispose to rupture of the extensor tendon. If this tumour is a regular finding in Parsonage-Turner syndrome, it may also help in making a definitive diagnosis.

  16. Does the A9285G Polymorphism in Collagen Type XII α1 Gene Associate with the Risk of Anterior Cruciate Ligament Ruptures?

    PubMed

    Ficek, K; Stepien-Slodkowska, M; Kaczmarczyk, M; Maciejewska-Karlowska, A; Sawczuk, M; Cholewinski, J; Leonska-Duniec, A; Zarebska, A; Cieszczyk, P; Zmijewski, P

    2014-06-01

    One of the most severe injuries sustained by athletes is rupture of the anterior cruciate ligament (ACL). Recent investigations suggest that a predisposition for ACL rupture may be the result of specific genetic sequence variants. In light of this, we decided to investigate whether the COL12A1 A9285G polymorphism was associated with ACL ruptures in Polish football players. We compared genotypic and allelic frequencies of the COL12A1 A9285G polymorphism in two groups of athletes: 91 male football players (23 ± 3 years) with surgically diagnosed primary ACL ruptures who qualified for ligament reconstruction (cases) and 143 apparently healthy, male football players of the same ethnicity, a similar age category, and a comparable level of exposure to ACL injury, who were without any self-reported history of ligament or tendon injury (controls). DNA samples extracted from the oral epithelial cells were genotyped by using a real-time polymerase chain reaction (Ri-Ti-PCR) method. The genotype distribution in the cases were not different from those in controls (p = 0.70). The frequency of the G allele was lower in the cases (18.1%) but not statistically significant (p = 0.40) when compared with controls (21.3%). Our results are in contradiction to the hypothesis that the COL12A1 A9285G polymorphism is associated with a predisposition for ACL injury. However, these conclusions should be supported with more experimental studies on COL12A1 polymorphisms. PMID:25741214

  17. UTERINE RUPTURE FOLLOWING MYOMECTOMY IN THIRD TRIMESTER.

    PubMed

    Djaković, Ivka; Rudman, Senka Sabolović; Kosec, Vesna

    2015-12-01

    Rupture of gravid uterus is surgical emergency causing maternal and fetal morbidity and mortality. The risk of uterine rupture is associated with uterine scars caused by previous cesarean section, myomectomy, hysteroscopic procedures, and curettage. We report a case of a 40-year-old woman in 31st week of gestation with spontaneous uterine rupture. It was her third pregnancy. She had two healthy children from previous pregnancies. Her symptoms were abdominal pain, vomiting and pain in the right shoulder lasting for 12 hours prior to admission. Ultrasound examination at admission revealed a dead fetus in the abdomen and free fluid in the abdominal cavity. She had previously undergone laparoscopic myomectomy. After myomectomy, she had one successful vaginal delivery. Every abdominal pain in pregnant woman with uterine scar should be carefully and promptly examined to exclude uterine rupture before further diagnostic procedures. This early time frame is essential for survival of the fetus and sometimes even of the mother. Uterine rupture represents indication for immediate cesarean section and it should be performed within 25 minutes of the first signs of uterine rupture. As shown in the case presented, one successful vaginal delivery after myomectomy is no guarantee for future pregnancies.

  18. LOX Tank Rupture

    NASA Technical Reports Server (NTRS)

    1986-01-01

    The bright luminous glow at the top is attributed to the rupture of the liquid oxygen tank just above the SRB/ET attachment. At this point, Challenger is completely engulfed in a firey flow of escaping liquid propellant.

  19. Achilles tendon rupture - aftercare

    MedlinePlus

    Heel cord tear; Calcaneal tendon rupture ... MRI scan to see what type of Achilles tendon tear you have. An MRI is a type ... partial tear means at least some of the tendon is still OK. A full tear means your ...

  20. Intracranial Aneurysms: Wall Motion Analysis for Prediction of Rupture.

    PubMed

    Vanrossomme, A E; Eker, O F; Thiran, J-P; Courbebaisse, G P; Zouaoui Boudjeltia, K

    2015-10-01

    Intracranial aneurysms are a common pathologic condition with a potential severe complication: rupture. Effective treatment options exist, neurosurgical clipping and endovascular techniques, but guidelines for treatment are unclear and focus mainly on patient age, aneurysm size, and localization. New criteria to define the risk of rupture are needed to refine these guidelines. One potential candidate is aneurysm wall motion, known to be associated with rupture but difficult to detect and quantify. We review what is known about the association between aneurysm wall motion and rupture, which structural changes may explain wall motion patterns, and available imaging techniques able to analyze wall motion. PMID:25929878

  1. From AAA to Acuros XB-clinical implications of selecting either Acuros XB dose-to-water or dose-to-medium.

    PubMed

    Zifodya, Jackson M; Challens, Cameron H C; Hsieh, Wen-Long

    2016-06-01

    When implementing Acuros XB (AXB) as a substitute for anisotropic analytic algorithm (AAA) in the Eclipse Treatment Planning System, one is faced with a dilemma of reporting either dose to medium, AXB-Dm or dose to water, AXB-Dw. To assist with decision making on selecting either AXB-Dm or AXB-Dw for dose reporting, a retrospective study of treated patients for head & neck (H&N), prostate, breast and lung is presented. Ten patients, previously treated using AAA plans, were selected for each site and re-planned with AXB-Dm and AXB-Dw. Re-planning was done with fixed monitor units (MU) as well as non-fixed MUs. Dose volume histograms (DVH) of targets and organs at risk (OAR), were analyzed in conjunction with ICRU-83 recommended dose reporting metrics. Additionally, comparisons of plan homogeneity indices (HI) and MUs were done to further highlight the differences between the algorithms. Results showed that, on average AAA overestimated dose to the target volume and OARs by less than 2.0 %. Comparisons between AXB-Dw and AXB-Dm, for all sites, also showed overall dose differences to be small (<1.5 %). However, in non-water biological media, dose differences between AXB-Dw and AXB-Dm, as large as 4.6 % were observed. AXB-Dw also tended to have unexpectedly high 3D maximum dose values (>135 % of prescription dose) for target volumes with high density materials. Homogeneity indices showed that AAA planning and optimization templates would need to be adjusted only for the H&N and Lung sites. MU comparison showed insignificant differences between AXB-Dw relative to AAA and between AXB-Dw relative to AXB-Dm. However AXB-Dm MUs relative to AAA, showed an average difference of about 1.3 % signifying an underdosage by AAA. In conclusion, when dose is reported as AXB-Dw, the effect that high density structures in the PTV has on the dose distribution should be carefully considered. As the results show overall small dose differences between the algorithms, when

  2. From AAA to Acuros XB-clinical implications of selecting either Acuros XB dose-to-water or dose-to-medium.

    PubMed

    Zifodya, Jackson M; Challens, Cameron H C; Hsieh, Wen-Long

    2016-06-01

    When implementing Acuros XB (AXB) as a substitute for anisotropic analytic algorithm (AAA) in the Eclipse Treatment Planning System, one is faced with a dilemma of reporting either dose to medium, AXB-Dm or dose to water, AXB-Dw. To assist with decision making on selecting either AXB-Dm or AXB-Dw for dose reporting, a retrospective study of treated patients for head & neck (H&N), prostate, breast and lung is presented. Ten patients, previously treated using AAA plans, were selected for each site and re-planned with AXB-Dm and AXB-Dw. Re-planning was done with fixed monitor units (MU) as well as non-fixed MUs. Dose volume histograms (DVH) of targets and organs at risk (OAR), were analyzed in conjunction with ICRU-83 recommended dose reporting metrics. Additionally, comparisons of plan homogeneity indices (HI) and MUs were done to further highlight the differences between the algorithms. Results showed that, on average AAA overestimated dose to the target volume and OARs by less than 2.0 %. Comparisons between AXB-Dw and AXB-Dm, for all sites, also showed overall dose differences to be small (<1.5 %). However, in non-water biological media, dose differences between AXB-Dw and AXB-Dm, as large as 4.6 % were observed. AXB-Dw also tended to have unexpectedly high 3D maximum dose values (>135 % of prescription dose) for target volumes with high density materials. Homogeneity indices showed that AAA planning and optimization templates would need to be adjusted only for the H&N and Lung sites. MU comparison showed insignificant differences between AXB-Dw relative to AAA and between AXB-Dw relative to AXB-Dm. However AXB-Dm MUs relative to AAA, showed an average difference of about 1.3 % signifying an underdosage by AAA. In conclusion, when dose is reported as AXB-Dw, the effect that high density structures in the PTV has on the dose distribution should be carefully considered. As the results show overall small dose differences between the algorithms, when

  3. Surgical Strategies for Acutely Ruptured Arteriovenous Malformations.

    PubMed

    Martinez, Jaime L; Macdonald, R Loch

    2015-01-01

    Brain arteriovenous malformations (AVMs) are focal neurovascular lesions consisting of abnormal fistulous connections between the arterial and venous systems with no interposed capillaries. This arrangement creates a high-flow circulatory shunt with hemorrhagic risk and hemodynamic abnormalities. While most AVMs are asymptomatic, they may cause severe neurological complications and death. Each AVM carries an annual rupture risk of 2-4%. Intracranial hemorrhage due to AVM rupture is the most common initial manifestation (up to 70% of presentations), and it carries significant morbidity and mortality. This complication is particularly important in the young and otherwise healthy population, in whom AVMs cause up to one-third of all hemorrhagic strokes. A previous rupture is the single most important independent predictor of future hemorrhage. Current treatment modalities for AVM are microsurgery, endovascular embolization, and radiosurgery. In acutely ruptured AVMs, early microsurgical excision is usually avoided. The standard is to wait at least 4 weeks to allow for patient recovery, hematoma liquefaction, and inflammatory reactions to subside. Exceptions to this rule are small, superficial, low-grade AVMs with elucidated angioarchitecture, for which early simultaneous hematoma evacuation and AVM excision is feasible. Emergent hematoma evacuation with delayed AVM excision (unless, as mentioned, the AVM is low grade) is recommended in patients with a decreased level of consciousness due to intracranial hemorrhage, posterior fossa or temporal lobe hematoma of >30 ml, or hemispheric hematoma of >60 ml. The applicability of endovascular techniques for acutely ruptured AVMs is not clear, but feasible options, until a definitive treatment is determined, include occluding intranidal and distal flow-related aneurysms and 'sealing' any rupture site or focal angioarchitectural weakness when one can be clearly identified and safely accessed. Radiosurgery is not performed in

  4. Differential expression of TRAIL and its receptors relative to calcification in AAA

    SciTech Connect

    Liu, Xun . E-mail: mpscrs@bath.ac.uk; Winrow, Vivienne R.; Horrocks, Michael; Stevens, Cliff R.

    2007-06-22

    Abdominal aortic aneurysm (AAA) is commonly associated with atherosclerosis. Human AAA tissue displays cells undergoing all stages of apoptosis. Tumour necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) induces apoptosis in tumour cells but not in normal cells. It has death receptors and decoy receptors. An inhibitor of TRAIL, osteoprotegerin (OPG), is involved in osteogenesis and vascular calcification. We investigated TRAIL and its receptors in AAA compared within normal aorta (NA). Both qualitative and quantitative analyses of calcification in AAA walls were determined using Von Kossa staining and pre-operation computer tomography (CT) scans. There was a significant difference in calcification level at different locations in the AAA wall (p < 0.05). Apoptosis was confirmed in AAA by TUNEL assay. A significant difference in TRAIL and its receptor expression was observed between normal aortae and AAA (p < 0.05). Significant differences were also observed between tissues displaying different extents of calcification for TRAIL mRNA (p < 0.05) by RT-PCR examination and OPG protein (p < 0.01) by protein blotting examination. We propose that this pattern of expression of TRAIL and its receptors may contribute to AAA formation and calcification in the AAA wall.

  5. Adapting the machine: adaptor proteins for Hsp100/Clp and AAA+ proteases.

    PubMed

    Kirstein, Janine; Molière, Noël; Dougan, David A; Turgay, Kürşad

    2009-08-01

    Members of the AAA+ protein superfamily contribute to many diverse aspects of protein homeostasis in prokaryotic cells. As a fundamental component of numerous proteolytic machines in bacteria, AAA+ proteins play a crucial part not only in general protein quality control but also in the regulation of developmental programmes, through the controlled turnover of key proteins such as transcription factors. To manage these many, varied tasks, Hsp100/Clp and AAA+ proteases use specific adaptor proteins to enhance or expand the substrate recognition abilities of their cognate protease. Here, we review our current knowledge of the modulation of bacterial AAA+ proteases by these cellular arbitrators.

  6. Bilateral patellar tendon rupture associated with statin use

    PubMed Central

    Kearns, Marie C.; Singh, Vinay K.

    2016-01-01

    Patellar tendon rupture is an uncommon clinical presentation, which generally affects the under 40s who are active in sport. Bilateral rupture of both tendons is much rarer. It occurs most frequently in patients with predisposing factors such as corticosteroid use or systemic diseases. The authors present the case of a 56-year-old male on long-term statin therapy who sustained this injury following a fall on ice. He had no known risk factors for tendon rupture. Surgical treatment involved tendon repair using Krakow suture via bony tunnels in the patella. Statins have previously been associated with tendon ruptures at other sites but there have been no published cases of bilateral patellar tendon rupture linked to statin use. We review the literature regarding the association between statins and tendon rupture. PMID:27165749

  7. Engineering fluorescent protein substrates for the AAA+ Lon protease.

    PubMed

    Wohlever, Matthew L; Nager, Andrew R; Baker, Tania A; Sauer, Robert T

    2013-04-01

    AAA+ proteases, such as Escherichia coli Lon, recognize protein substrates by binding to specific peptide degrons and then unfold and translocate the protein into an internal degradation chamber for proteolysis. For some AAA+ proteases, attaching specific degrons to the N- or C-terminus of green fluorescent protein (GFP) generates useful substrates, whose unfolding and degradation can be monitored by loss of fluorescence, but Lon fails to degrade appropriately tagged GFP variants at a significant rate. Here, we demonstrate that Lon catalyzes robust unfolding and degradation of circularly permuted variants of GFP with a β20 degron appended to the N terminus or a sul20 degron appended to the C terminus. Lon degradation of non-permuted GFP-sul20 is very slow, in part because the enzyme cannot efficiently extract the degron-proximal C-terminal β-strand to initiate denaturation. The circularly permuted GFP substrates described here allow convenient high-throughput assays of the kinetics of Lon degradation in vitro and also permit assays of Lon proteolysis in vivo.

  8. Training Scientists to be Effective Communicators: AAAS Communicating Science Workshops

    NASA Astrophysics Data System (ADS)

    Cendes, L.; Lohwater, T.

    2012-12-01

    "Communicating Science: Tools for Scientists and Engineers" is a workshop program developed by AAAS to provide guidance and practice for scientists and engineers in communicating about science with public audiences. The program was launched at the 2008 AAAS Annual Meeting in Boston and has since provided 24 workshops for more than 1,500 scientist and engineer attendees at universities, science society meetings, and government agency labs around the United States. Each interactive workshop targets scientists and engineers specifically and has included content such as message development, defining audience, identifying opportunities for engaging the public, and practice with public presentations and cameras. The workshop format allows for collaborative learning through small-group discussion, resource sharing, and participation in critique of other participants' presentations. Continuous monitoring of the program includes on-site and online surveys and evaluation. On an assessment of workshops from 2008-2010, attendees reported that knowledge gained from the workshop helped in crafting messages about their scientific work for use in communicating with public audiences, and approximately 80 percent of respondents reported participation in communication with a public audience after attending the workshop. Through workshop content and feedback of participating scientists, this presentation will highlight some best practices and resources for scientists who want to take a proactive role in science communication.

  9. Endovascular Therapy of Ruptured Abdominal Aortic Aneurysm: Mid- and Long-Term Results

    SciTech Connect

    Kubin, Klaus Sodeck, Gottfried H.; Teufelsbauer, H.; Nowatschka, Bernd; Kretschmer, Georg; Lammer, Johannes; Schoder, Maria

    2008-05-15

    As an alternative to open aneurysm repair, emergency endovascular aortic repair (EVAR) has emerged as a promising technique for ruptured abdominal aortic aneurysm (rAAA) within the last decade. The aim of this retrospective study is to present early and late outcomes of patients treated with EVAR for rAAA. Twenty-two patients (5 women, 17 men; mean age, 74 years) underwent EVAR for rAAA between November 2000 and April 2006. Diagnostic multislice computed tomography angiography was performed prior to stent-graft repair to evaluate anatomical characteristics and for follow-up examinations. Periprocedural patient characteristics and technical settings were evaluated. Mortality rates, hospital stay, and early and late complications, within a mean follow-up time of 744 {+-} 480 days, were also assessed. Eight of 22 patients were hemodynamically unstable at admission. Stent-graft insertion was successful in all patients. The total early complication rate was 54%, resulting in a 30-day mortality rate of 23%. The median intensive care unit stay was 2 days (range, 2-48 days), and the median hospital stay was 16 days (range, 9-210 days). During the follow-up period, three patients suffered from stent-graft-related complications. The overall mortality rate in our study group was 36%. EVAR is an acceptable, minimally invasive treatment option in patients with acute rAAA, independent of the patient's general condition. Short- and long-term outcomes are definitely comparable to those with open surgical repair procedures.

  10. Percutaneous Treatment of Sac Rupture in Abdominal Aortic Aneurysms Previously Excluded with Endovascular Repair (EVAR)

    SciTech Connect

    Lagana, Domenico Mangini, Monica Fontana, Federico; Nicotera, Paolo; Carrafiello, Gianpaolo; Fugazzola, Carlo

    2009-01-15

    The purpose of this study was to assess the feasibility and effectiveness of percutaneous endovascular repair of ruptured abdominal aortic aneurysms (AAAs) previously treated by EVAR. In the last year, two male patients with AAAs, treated 8 and 23 months ago with bifurcated stent-graft, were observed because of lumbar pain and hemorragic shock. Multidetector computed tomography (MDCT) showed a retroperitoneal hematoma; in both cases a type III endoleak was detected, in one case associated with a type II endoleak from the iliolumbar artery. The procedures were performed in the theater, in emergency. Type II endoleak was treated with transcatheter superselective glue injection; type III endoleaks were excluded by a stent-graft extension. The procedures were successful in both patients, with immediate hemodynamic stabilization. MDCT after the procedure showed complete exclusion of the aneurysms. In conclusion, endovascular treatment is a safe and feasible option for the treatment of ruptured AAAs previously treated by EVAR; this approach allows avoidance of surgical conversion, which is technical very challenging, with a high morbidity and mortality rate.

  11. Patient specific stress and rupture analysis of ascending thoracic aneurysms.

    PubMed

    Trabelsi, Olfa; Davis, Frances M; Rodriguez-Matas, Jose F; Duprey, Ambroise; Avril, Stéphane

    2015-07-16

    An ascending thoracic aortic aneurysm (ATAA) is a serious medical condition which, more often than not, requires surgery. Aneurysm diameter is the primary clinical criterion for determining when surgical intervention is necessary but, biomechanical studies have suggested that the diameter criterion is insufficient. This manuscript presents a method for obtaining the patient specific wall stress distribution of the ATAA and the retrospective rupture risk for each patient. Five human ATAAs and the preoperative dynamic CT scans were obtained during elective surgeries to replace each patient's aneurysm with a synthetic graft. The material properties and rupture stress for each tissue sample were identified using bulge inflation tests. The dynamic CT scans were used to generate patient specific geometries for a finite element (FE) model of each patient's aneurysm. The material properties from the bulge inflation tests were implemented in the FE model and the wall stress distribution at four different pressures was estimated. Three different rupture risk assessments were compared: the maximum diameter, the rupture risk index, and the overpressure index. The peak wall stress values for the patients ranged from 28% to 94% of the ATAA's failure stress. The rupture risk and overpressure indices were both only weakly correlated with diameter (ρ=-0.29, both cases). In the future, we plan to conduct a large experimental and computational study that includes asymptomatic patients under surveillance, patients undergoing elective surgery, and patients who have experienced rupture or dissection to determine if the rupture risk index or maximum diameter can meaningfully differentiate between the groups. PMID:25979384

  12. Analysis of a Typical Chinese High School Biology Textbook Using the AAAS Textbook Standards

    ERIC Educational Resources Information Center

    Liang, Ye; Cobern, William W.

    2013-01-01

    The purpose of this study was to evaluate a typical Chinese high school biology textbook using the textbook standards of the American Association for the Advancement of Science (AAAS). The data were composed of three chapters selected from the textbook. Each chapter was analyzed and rated using the AAAS textbook standards. Pearson correlations…

  13. Postmyomectomic Uterine Rupture Despite Cesarean Section.

    PubMed

    Kacperczyk, Joanna; Bartnik, Paweł; Romejko-Wolniewicz, Ewa; Dobrowolska-Redo, Agnieszka

    2016-03-01

    Uterine fibroids (leiomyomas) are benign smooth muscle tumors of the uterus. Fibroids can develop anywhere within the muscular wall. Leiomyomas may be associated with infertility. Laparoscopic myomectomy is often used to remove symptomatic intramural or subserosal fibroids. Advantages of the procedure include short recovery time and minimal perioperative morbidity. At the same time, the multilayer suture technique is more complicated during laparoscopy. A rare but serious complication of laparoscopic myomectomies is uterine rupture. A brief review of the literature and a clinical example of a 33-year-old woman with history of infertility, laparoscopic myomectomies and uterine rupture followed by peripartum hemorrhage is presented. The treatment of leiomyomas is a challenge not only because of possible recurrence but also due to long-term consequences following successful myomectomy. Management of patients with uterine scars should include careful planning of the route of delivery, as the risk of rupture may be increased. PMID:26976991

  14. Premature rupture of membranes

    MedlinePlus

    ... the 37th week of pregnancy, it is called preterm premature rupture of membranes (PPROM). The earlier your water breaks, the more ... babies born early). If there is not a preterm unit where you deliver, you and your baby will be moved to a hospital that has one.

  15. [Stomach rupture while diving].

    PubMed

    Russi, E; Gäumann, N; Geroulanos, S; Bühlmann, A A

    1985-06-01

    A case of stomach rupture in a 47-year-old scuba diver is reported. Symptoms of gastrointestinal expansion during ascent are quite common and are caused by decompression of swallowed air. Gastric perforation is however rare, and needs to be promptly recognized and surgically repaired.

  16. Labyrinthine window rupture.

    PubMed

    Fraser, J G; Harborow, P C

    1975-01-01

    Some cases of sensorineural deafness are due to labyrinthine window rupture. Three cases have been presented to illustrate different aspects of diagnosis and managment of this condition. The indications for surgical intervention have been discussed. The importance of making the diagnosis is that operation can relieve vertigo and restore the hearing.

  17. The effect of aortic morphology on peri-operative mortality of ruptured abdominal aortic aneurysm

    PubMed Central

    2015-01-01

    Aims To investigate whether aneurysm shape and extent, which indicate whether a patient with ruptured abdominal aortic aneurysm (rAAA) is eligible for endovascular repair (EVAR), influence the outcome of both EVAR and open surgical repair. Methods and results The influence of six morphological parameters (maximum aortic diameter, aneurysm neck diameter, length and conicality, proximal neck angle, and maximum common iliac diameter) on mortality and reinterventions within 30 days was investigated in rAAA patients randomized before morphological assessment in the Immediate Management of the Patient with Rupture: Open Versus Endovascular strategies (IMPROVE) trial. Patients with a proven diagnosis of rAAA, who underwent repair and had their admission computerized tomography scan submitted to the core laboratory, were included. Among 458 patients (364 men, mean age 76 years), who had either EVAR (n = 177) or open repair (n = 281) started, there were 155 deaths and 88 re-interventions within 30 days of randomization analysed according to a pre-specified plan. The mean maximum aortic diameter was 8.6 cm. There were no substantial correlations between the six morphological variables. Aneurysm neck length was shorter in those undergoing open repair (vs. EVAR). Aneurysm neck length (mean 23.3, SD 16.1 mm) was inversely associated with mortality for open repair and overall: adjusted OR 0.72 (95% CI 0.57, 0.92) for each 16 mm (SD) increase in length. There were no convincing associations of morphological parameters with reinterventions. Conclusion Short aneurysm necks adversely influence mortality after open repair of rAAA and preclude conventional EVAR. This may help explain why observational studies, but not randomized trials, have shown an early survival benefit for EVAR. Clinical trial registration: ISRCTN 48334791. PMID:25627357

  18. Blood flow characteristics in a terminal basilar tip aneurysm prior to its fatal rupture

    PubMed Central

    Sforza, D.M.; Putman, C.M.; Scrivano, E.; Lylyk, P.; Cebral, J.R.

    2010-01-01

    Background and Purpose The development and validation of methods to stratify the risk of rupture of cerebral aneurysms is highly desired since current treatment risks can exceed the natural risk of rupture. Because unruptured aneurysms are typically treated before they rupture, it is very difficult to connect the proposed risk indices to the rupture of an individual aneurysm. The purpose of this case study was to analyze the hemodynamic environment of a saccular aneurysm of the terminal morphology sub-type that was imaged just prior to its rupture and to test whether the hemodynamic characteristics would designate this particular aneurysm as at high risk. Methods A patient-specific computational fluid dynamics model was constructed from 3D rotational angiography images acquired just hours before the aneurysm ruptured. A pulsatile flow calculation was performed and hemodynamic characteristics previously connected to rupture were analyzed. Results It was found that the aneurysm had a concentrated inflow stream, small impingement region, complex intra-aneurysmal flow structure, asymmetric flow split from the parent vessel to the aneurysm and daughter branches, and high levels of aneurysmal wall shear stress near the impaction zone. Conclusions The hemodynamics characteristics observed in this aneurysm right before its rupture are consistent with previous studies correlating aneurysm rupture and hemodynamic patterns in saccular and terminal aneurysms. This study supports the notion that hemodynamic information may be used to help stratify the rupture risk of cerebral aneurysms. PMID:20150312

  19. A Three Year Clinicopathological Study of Cases of Rupture Uterus

    PubMed Central

    Rathod, Setu; Swain, Sujata

    2015-01-01

    Introduction Rupture uterus is a life threatening obstetric complication with serious maternal and fetal side-effects. We report a 3 year (2010-2013) retrospective clinical study of pregnancy with rupture uterus cases attending a tertiary care hospital. Aim The aim of the study was to evaluate the incidence of rupture uterus, incidence as per age, parity, clinical presentations, risk factors, complications and management. Materials and Methods Retrospective data of 74 cases of rupture uterus in SCB Medical college, Cuttack was collected from case records of 26,547 deliveries during a 3 year span (2010-2013). Parameters like cause of rupture, type, site of rupture and outcome were recorded. The collected data was analysed by SPSS software v19. Results Out of 26,547 deliveries during the three year period, there were 74 cases of rupture uterus with an incidence of rupture 1 in 359 (0.28%). The mean age of rupture uterus was 27.4 years. 95.8% were multigravida and majority were referred cases from low socioeconomic status. Only 40.5% had the required minimum of four antenatal visits as recommended by WHO (World Health Organisation). A total of 48.6% of cases with rupture uterus had history of previous Caesarean section. Prolonged labour was present in 75.6% of the cases. Only 12.2% of the cases had history of oxytocin use whereas 9.5% had undergone an operative vaginal delivery. Obstructed labour was the cause in 24.3% of cases, 85.1% had complete rupture. Majority had a rupture in the anterior wall (69%) and 81.1% had rupture in lower segment of uterus. Only 17.6% had broad ligament haematoma, 10.8% colporrhexis and 6.8% had associated bladder injury. Repair was possible in only 39.2% of cases, whereas majority landed up in hysterectomy. Internal iliac ligation was done in 2.7% of cases. Perinatal mortality was 90.5% whereas maternal death was seen in 13.5% cases. One patient developed VVF (vesicovaginal fistula). Duration of hospital stay was upto 14 days in 81

  20. Premature rupture of membranes.

    PubMed Central

    Poma, P. A.

    1996-01-01

    The management of patients with premature rupture of membranes has changed markedly in the past several years. The basis for this is a combination of a better understanding of newborn physiology, improved neonatal care, refinements in antibiotic therapy, and the widespread use of maternal and fetal monitoring. The best outcome for both mother and infant undoubtedly reflects data based on a combination of factors, among which are gestational age survival, evidence of fetal distress, presence or absence of labor and sepsis, and of course, the cervical condition as it is related to labor-readiness. An important recent advance is the recognition that an active observation management program is associated with less morbidity and mortality than the classic management course of delivery within 12 hours of membrane rupture. The fact that preterm premature rupture of membranes tends to recur in subsequent pregnancies offers an opportunity for prevention. Moreover, advances in perinatal and neonatal care will continue to improve the outcomes of these women and their children. PMID:8583489

  1. Rupture of bicornuate uterus

    PubMed Central

    Jayaprakash, Sheela; Muralidhar, Lakshmidevi; G, Sampathkumar; Sexsena, Rajivkumar

    2011-01-01

    A primigravida aged 20 years was referred to Vydehi Institute of Medical Sciences with diagnosis of 30 weeks of period of gestation with eclampsia and failure to respond to induction with misoprostol and she was on Pritchard regimen for the treatment of eclampsia and there was no response to induction of labour and emergency ultrasound was taken and it showed an extrauterine gestation of 30 weeks gestation with fetal demise and free fluid in peritoneum. A tentative diagnosis of secondary abdominal pregnancy with eclampsia was made and she was taken for emergency laprotomy. Intra operative findings showed haemoperitoneum, fetus with placenta and membranes in the peritoneal cavity, there was bicornuate uterus and right horn was ruptured from the fundus to about 8 cm down in the posterior aspect and ruptured part was sutured in two layers. After securing perfect haemostasis, abdomen was closed. This paper illustrates a case report of uterine anomaly with 30 weeks period of gestation and eclampsia and rupture following induction with prostaglandins. PMID:22675095

  2. Rupture of bicornuate uterus.

    PubMed

    Jayaprakash, Sheela; Muralidhar, Lakshmidevi; Sampathkumar, G; Sexsena, Rajivkumar

    2011-01-01

    A primigravida aged 20 years was referred to Vydehi Institute of Medical Sciences with diagnosis of 30 weeks of period of gestation with eclampsia and failure to respond to induction with misoprostol and she was on Pritchard regimen for the treatment of eclampsia and there was no response to induction of labour and emergency ultrasound was taken and it showed an extrauterine gestation of 30 weeks gestation with fetal demise and free fluid in peritoneum. A tentative diagnosis of secondary abdominal pregnancy with eclampsia was made and she was taken for emergency laprotomy. Intra operative findings showed haemoperitoneum, fetus with placenta and membranes in the peritoneal cavity, there was bicornuate uterus and right horn was ruptured from the fundus to about 8 cm down in the posterior aspect and ruptured part was sutured in two layers. After securing perfect haemostasis, abdomen was closed. This paper illustrates a case report of uterine anomaly with 30 weeks period of gestation and eclampsia and rupture following induction with prostaglandins. PMID:22675095

  3. Rupture of bicornuate uterus.

    PubMed

    Jayaprakash, Sheela; Muralidhar, Lakshmidevi; Sampathkumar, G; Sexsena, Rajivkumar

    2011-10-28

    A primigravida aged 20 years was referred to Vydehi Institute of Medical Sciences with diagnosis of 30 weeks of period of gestation with eclampsia and failure to respond to induction with misoprostol and she was on Pritchard regimen for the treatment of eclampsia and there was no response to induction of labour and emergency ultrasound was taken and it showed an extrauterine gestation of 30 weeks gestation with fetal demise and free fluid in peritoneum. A tentative diagnosis of secondary abdominal pregnancy with eclampsia was made and she was taken for emergency laprotomy. Intra operative findings showed haemoperitoneum, fetus with placenta and membranes in the peritoneal cavity, there was bicornuate uterus and right horn was ruptured from the fundus to about 8 cm down in the posterior aspect and ruptured part was sutured in two layers. After securing perfect haemostasis, abdomen was closed. This paper illustrates a case report of uterine anomaly with 30 weeks period of gestation and eclampsia and rupture following induction with prostaglandins.

  4. Surgical repair of ruptured abdominal aortic aneurysm with non-bleeding aortocaval fistula.

    PubMed

    Unosawa, Satoshi; Kimura, Haruka; Niino, Tetsuya

    2013-01-01

    We present a case of an aortocaval fistula (ACF) without bleeding because a clot was covering the fistula. A 60-year-old man was diagnosed as having a ruptured abdominal aortic aneurysm (AAA) and an aortocaval fistula, by enhanced computed tomography (CT). After the aneurysm had been opened, the fistula was detected, but there was no bleeding because it was covered with clot. After graft repair, bleeding from the fistula occurred when the clot was removed by suction. Direct closure of the fistula was achieved after bleeding was controlled by digital compression. PMID:23825505

  5. Modelling of residually stressed materials with application to AAA.

    PubMed

    Ahamed, T; Dorfmann, L; Ogden, R W

    2016-08-01

    Residual stresses are generated in living tissues by processes of growth and adaptation and they significantly influence the mechanical behaviour of the tissues. Thus, to effectively model the elastic response of the tissues relative to a residually stressed configuration the residual stresses need to be incorporated into the constitutive equations. The purposes of this paper are (a) to summarise a general elastic constitutive formulation that includes residual stress, (b) to specify the tensors needed for the three-dimensional implementation of the theory in a nonlinear finite element code, and (c) to use the theory and its implementation to evaluate the wall stress distribution in an abdominal aortic aneurysm (AAA) using patient specific geometry and material model parameters. The considered material is anisotropic with two preferred directions indicating the orientation of the collagen fibres in the aortic tissue. The method described in this paper is general and can be used, by specifying appropriate energy functions, to investigate other residually stressed biological systems. PMID:26874252

  6. AAA: Road Debris a Mounting Danger on U.S. Highways

    MedlinePlus

    ... Highways Crashes involving objects that have fallen from vehicles up 40 percent since 2001 To use the ... the AAA Foundation for Traffic Safety. Crashes involving vehicle-related debris are up 40 percent since the ...

  7. The talent endoluminal AAA stent-graft system. Report of the phase I USA trial, and summary of worldwide experience.

    PubMed

    Criado, F J; Fry, P D; Machan, L S; Twena, M; Patten, P

    1998-12-01

    In the United States, the Phase I Feasibility Study under IDE G970065 was approved by the Food and Drug Administration on 04/11/97. The approved protocol called for implantation of the bifurcated Talent spring stent-graft system on patients who are high-risk candidates for conventional surgery because of cardio-respiratory, medical, general, or local anatomical reasons which would likely complicate the technical execution of the operation or be accompanied by a high expected mortality rate. Patient enrollment was complete with 16 cases as of September 26, 1997. This was a multicenter experience involving five different sites. This is an ongoing study and patients, of course, will continue to be followed longitudinally. Phase II will likely be approved by the FDA for initiation in January or February of 1998. Standard-risk AAA patients will be entered into the study at this time; comparison with concurrent controls will be used for comparison with conventional surgery. PMID:9894193

  8. An AAA-DDD triply hydrogen-bonded complex easily accessible for supramolecular polymers.

    PubMed

    Han, Yi-Fei; Chen, Wen-Qiang; Wang, Hong-Bo; Yuan, Ying-Xue; Wu, Na-Na; Song, Xiang-Zhi; Yang, Lan

    2014-12-15

    For a complementary hydrogen-bonded complex, when every hydrogen-bond acceptor is on one side and every hydrogen-bond donor is on the other, all secondary interactions are attractive and the complex is highly stable. AAA-DDD (A=acceptor, D=donor) is considered to be the most stable among triply hydrogen-bonded sequences. The easily synthesized and further derivatized AAA-DDD system is very desirable for hydrogen-bonded functional materials. In this case, AAA and DDD, starting from 4-methoxybenzaldehyde, were synthesized with the Hantzsch pyridine synthesis and Friedländer annulation reaction. The association constant determined by fluorescence titration in chloroform at room temperature is 2.09×10(7)  M(-1) . The AAA and DDD components are not coplanar, but form a V shape in the solid state. Supramolecular polymers based on AAA-DDD triply hydrogen bonded have also been developed. This work may make AAA-DDD triply hydrogen-bonded sequences easily accessible for stimuli-responsive materials.

  9. Slow rupture of frictional interfaces

    NASA Astrophysics Data System (ADS)

    Bar Sinai, Yohai; Brener, Efim A.; Bouchbinder, Eran

    2012-02-01

    The failure of frictional interfaces and the spatiotemporal structures that accompany it are central to a wide range of geophysical, physical and engineering systems. Recent geophysical and laboratory observations indicated that interfacial failure can be mediated by slow slip rupture phenomena which are distinct from ordinary, earthquake-like, fast rupture. These discoveries have influenced the way we think about frictional motion, yet the nature and properties of slow rupture are not completely understood. We show that slow rupture is an intrinsic and robust property of simple non-monotonic rate-and-state friction laws. It is associated with a new velocity scale cmin, determined by the friction law, below which steady state rupture cannot propagate. We further show that rupture can occur in a continuum of states, spanning a wide range of velocities from cmin to elastic wave-speeds, and predict different properties for slow rupture and ordinary fast rupture. Our results are qualitatively consistent with recent high-resolution laboratory experiments and may provide a theoretical framework for understanding slow rupture phenomena along frictional interfaces.

  10. Ruptured tubal molar pregnancy.

    PubMed

    Yakasai, I A; Adamu, N; Galadanchi, H S

    2012-01-01

    Molar pregnancies in most instances develop within the uterine cavity, but may occur at any site. Ectopic molar pregnancy is a rare event. The objective of this study was to present a case of ruptured tubal molar gestation, discuss its clinical features and ways to improve diagnostic accuracy. A 35-year-old woman presented with features suggestive of ruptured tubal ectopic pregnancy. There was neither any evidence at the time of presentation to suspect a molar gestation, nor β human chorionic gonadotrophin (βhCG) hormone estimation was done, but only a clearview pregnancy test was carried out. She had total left salpingectomy and histological evaluation of the specimen revealed complete hydatidiform mole. The hCG level normalized within 3 weeks of follow-up. Clinical features of ectopic molar pregnancy may be indistinguishable from non-molar ectopic pregnancy. We recommend βhCG estimation as well as histological examination of the surgical specimen for all patients coming with features suggestive of ectopic pregnancy. PMID:23238205

  11. Verification of IMRT dose calculations using AAA and PBC algorithms in dose buildup regions.

    PubMed

    Oinam, Arun S; Singh, Lakhwant

    2010-08-26

    The purpose of this comparative study was to test the accuracy of anisotropic analytical algorithm (AAA) and pencil beam convolution (PBC) algorithms of Eclipse treatment planning system (TPS) for dose calculations in the low- and high-dose buildup regions. AAA and PBC algorithms were used to create two intensity-modulated radiotherapy (IMRT) plans of the same optimal fluence generated from a clinically simulated oropharynx case in an in-house fabricated head and neck phantom. The TPS computed buildup doses were compared with the corresponding measured doses in the phantom using thermoluminescence dosimeters (TLD 100). Analysis of dose distribution calculated using PBC and AAA shows an increase in gamma value in the dose buildup region indicating large dose deviation. For the surface areas of 1, 50 and 100 cm2, PBC overestimates doses as compared to AAA calculated value in the range of 1.34%-3.62% at 0.6 cm depth, 1.74%-2.96% at 0.4 cm depth, and 1.96%-4.06% at 0.2 cm depth, respectively. In high-dose buildup region, AAA calculated doses were lower by an average of -7.56% (SD = 4.73%), while PBC was overestimated by 3.75% (SD = 5.70%) as compared to TLD measured doses at 0.2 cm depth. However, at 0.4 and 0.6 cm depth, PBC overestimated TLD measured doses by 5.84% (SD = 4.38%) and 2.40% (SD = 4.63%), respectively, while AAA underestimated the TLD measured doses by -0.82% (SD = 4.24%) and -1.10% (SD = 4.14%) at the same respective depth. In low-dose buildup region, both AAA and PBC overestimated the TLD measured doses at all depths except -2.05% (SD = 10.21%) by AAA at 0.2 cm depth. The differences between AAA and PBC at all depths were statistically significant (p < 0.05) in high-dose buildup region, whereas it is not statistically significant in low-dose buildup region. In conclusion, AAA calculated the dose more accurately than PBC in clinically important high-dose buildup region at 0.4 cm and 0.6 cm depths. The use of an orfit cast increases the dose buildup

  12. RBMK pressure tube rupture assessment

    SciTech Connect

    Schmitt, B.E.; Tsiklauri, G.V.

    1994-08-01

    The Russian RBMK reactor core design consists of multiple parallel pressure tube channels that contain Zr clad, UO{sub 2} fuel pin bundles. These parallel channels are contained within graphite moderator blocks which are, in turn, contained within a sealed core cavity. Current safety evaluation efforts of the RBMK reactors have been concentrating in the area of tube ruptures within the core cavity and, in particular, multiple tube ruptures that could threaten the reactor core integrity. Tube rupture events result in a pressurization of the reactor core cavity. The original design overpressure for the cavity region was based on a single tube rupture, resulting in considerable margin to the top plate lift pressure. The top plate lift pressure is 3.1 bar, and a single tube rupture would result in approximately 1.4 bar. RBMK plant specific cavity pressure relief designs provide for between three and in simultaneous tube ruptures before exceeding the top plate lift pressure. Thus, current safety evaluations have begun to examine the potential for multiple tube ruptures that could exceed the current cavity pressure relief designs. One such scenario being examined is a partial rupture in a group distribution header that results in stagnated (low) flow to up to 40 pressure tubes. The subsequent fuel heatup in these reduced flow tubes could result in multiple tube ruptures beyond the design relief capacity of the core cavity. This paper examines several key issues in evaluating this transient, including: (1) the effects of low flow, (2) the effects of axial peaking, and (3) the effects of radial peaking, all relative to the time to tube rupture. These issues each play a significant role in attempting to evaluate the likelihood and severity of multiple tube ruptures for a partial group distribution header break.

  13. Spontaneous rupture on irregular faults

    NASA Astrophysics Data System (ADS)

    Liu, C.

    2014-12-01

    It is now know (e.g. Robinson et al., 2006) that when ruptures propagate around bends, the rupture velocity decrease. In the extreme case, a large bend in the fault can stop the rupture. We develop a 2-D finite difference method to simulate spontaneous dynamic rupture on irregular faults. This method is based on a second order leap-frog finite difference scheme on a uniform mesh of triangles. A relaxation method is used to generate an irregular fault geometry-conforming mesh from the uniform mesh. Through this numerical coordinate mapping, the elastic wave equations are transformed and solved in a curvilinear coordinate system. Extensive numerical experiments using the linear slip-weakening law will be shown to demonstrate the effect of fault geometry on rupture properties. A long term goal is to simulate the strong ground motion near the vicinity of bends, jogs, etc.

  14. Splenic rupture as a presenting feature of endocarditis.

    PubMed

    Winearls, James Roger; McGloughlin, Steven; Fraser, John F

    2009-04-01

    We describe the first case of infective endocarditis presenting with spontaneous splenic rupture. Our patient, a known intravenous drug user presented with hypovolaemic shock secondary to splenic rupture. The patient was resuscitated and underwent an emergency splenectomy. Subsequent clinical examination revealed a systolic murmur and a diagnosis of mitral valve infective endocarditis was made after echocardiography. Splenic tissue, blood cultures and mitral valve tissue all cultured Enterococcus faecalis. The patient had a successful mitral valve replacement and was discharged home after 44 days. To our knowledge this is the first reported case of enterococcal endocarditis presenting with splenic rupture. This case highlights the need to consider endocarditis in spontaneous splenic rupture particularly in those patients in a high risk group, such as IV drug users, especially if they lack a clear history of trauma. PMID:19217796

  15. Spontaneous Iliac Vein Rupture

    PubMed Central

    Kim, Dae Hwan; Park, Hyung Sub; Lee, Taeseung

    2015-01-01

    Spontaneous iliac vein rupture (SIVR) is a rare entity, which usually occurs without a precipitating factor, but can be a life-threatening emergency often requiring an emergency operation. This is a case report of SIVR in a 62-year-old female who presented to the emergency room with left leg swelling. Workup with contrast-enhanced computed tomography revealed a left leg deep vein thrombosis with May-Thurner syndrome and a hematoma in the pelvic cavity without definite evidence of arterial bleeding. She was managed conservatively without surgical intervention, and also underwent inferior vena cava filter insertion and subsequent anticoagulation therapy for pulmonary thromboembolism. This case shows that SIVR can be successfully managed with close monitoring and conservative management, and anticoagulation may be safely applied despite the patient presenting with venous bleeding. PMID:26217647

  16. Short-lived Supershear Rupture

    NASA Astrophysics Data System (ADS)

    Fukuyama, E.; Xu, S.; Yamashita, F.; Mizoguchi, K.; Takizawa, S.; Kawakata, H.

    2015-12-01

    Fukuyama and Olsen (2002) computed the supershear rupture initiation, propagation and termination process due to a passage of high stress drop area (called asperity) using a boundary integral equation method. They found that supershear rupture continued to propagate after the passage through high stress drop area but it died after a certain propagation distance, which depends on the elastic energy released at the high stress drop area. Here, we could reproduce a similar phenomenon in the laboratory. We conducted large-scale biaxial friction experiments using a pair of meter-scaled metagabbro rock specimens (VP=6.9km/s, VS=3.6km/s) at the National Research institute for Earth Science and Disaster Prevention (NIED). We observed several stick slip rupture events that initiated close to an asperity and immediately became supershear ruptures. But after propagating certain distance they died out and co-existing subshear ruptures became prominent. If we look into details, during the supershear rupture, we could see a sequence of rupture acceleration, its short rest and re-acceleration. This feature reminds us of a sequential breakage of small high stress patches as predicted by Fukuyama and Madariaga (2000). These observations might be interpreted under a concept of energy balance where the energy transmission from strain energy released by the asperity to fracture energy consumed at the crack tip was not instantaneously balanced in space. This could be related to the fact that earthquake rupture velocity is rather smooth reported from the finite fault analysis of large earthquakes with seismic waveforms. References Fukuyama, E. and R. Madariaga (2000) Dynamic propagation and interaction of a rupture front on a planar fault, PAGEOPH, 257, 1959-1979. Fukuyama, E. and K.B. Olsen (2002) A condition for super-shear rupture propagation in a heterogeneous stress field, PAGEOPH, 159, 2047-2056.

  17. Predictive biomechanical analysis of ascending aortic aneurysm rupture potential

    PubMed Central

    Martin, Caitlin; Sun, Wei; Pham, Thuy; Elefteriades, John

    2013-01-01

    Aortic aneurysm is a leading cause of death in adults, often taking lives without any premonitory signs or symptoms. Adverse clinical outcomes of aortic aneurysm are preventable by elective surgical repair; however, identifying at-risk individuals is difficult. The objective of this study was to perform a predictive biomechanical analysis of ascending aortic aneurysm (AsAA) tissue to assess rupture risk on a patient-specific level. AsAA tissues, obtained intra-operatively from 50 patients, were subjected to biaxial mechanical and uniaxial failure tests to obtain their passive elastic mechanical properties. A novel analytical method was developed to predict the AsAA pressure-diameter response as well as the aortic wall yield and failure responses. Our results indicated that the mean predicted AsAA diameter at rupture was 5.6 ± 0.7 cm, and the associated blood pressure to induce rupture was 579.4 ± 214.8 mmHg. Statistical analysis showed significant positive correlation between aneurysm tissue compliance and predicted risk of rupture, where patients with a pressure-strain modulus ≥100 kPa may be nearly twice as likely to experience rupture than patients with more compliant aortic tissue. The mechanical analysis of pre-dissection patient tissue properties established in this study could predict the “future” onset of yielding and rupture in AsAA patients. The analysis results implicate decreased tissue compliance as a risk factor for AsAA rupture. The presented methods may serve as a basis for the development of a pre-operative planning tool for AsAA evaluation, a tool currently unavailable. PMID:23948500

  18. Cytoplasmic dynein regulates its attachment to microtubules via nucleotide state-switched mechanosensing at multiple AAA domains.

    PubMed

    Nicholas, Matthew P; Berger, Florian; Rao, Lu; Brenner, Sibylle; Cho, Carol; Gennerich, Arne

    2015-05-19

    Cytoplasmic dynein is a homodimeric microtubule (MT) motor protein responsible for most MT minus-end-directed motility. Dynein contains four AAA+ ATPases (AAA: ATPase associated with various cellular activities) per motor domain (AAA1-4). The main site of ATP hydrolysis, AAA1, is the only site considered by most dynein motility models. However, it remains unclear how ATPase activity and MT binding are coordinated within and between dynein's motor domains. Using optical tweezers, we characterize the MT-binding strength of recombinant dynein monomers as a function of mechanical tension and nucleotide state. Dynein responds anisotropically to tension, binding tighter to MTs when pulled toward the MT plus end. We provide evidence that this behavior results from an asymmetrical bond that acts as a slip bond under forward tension and a slip-ideal bond under backward tension. ATP weakens MT binding and reduces bond strength anisotropy, and unexpectedly, so does ADP. Using nucleotide binding and hydrolysis mutants, we show that, although ATP exerts its effects via binding AAA1, ADP effects are mediated by AAA3. Finally, we demonstrate "gating" of AAA1 function by AAA3. When tension is absent or applied via dynein's C terminus, ATP binding to AAA1 induces MT release only if AAA3 is in the posthydrolysis state. However, when tension is applied to the linker, ATP binding to AAA3 is sufficient to "open" the gate. These results elucidate the mechanisms of dynein-MT interactions, identify regulatory roles for AAA3, and help define the interplay between mechanical tension and nucleotide state in regulating dynein motility.

  19. Identification of AAAS gene mutation in Allgrove syndrome: A report of three cases

    PubMed Central

    LI, WENJING; GONG, CHUNXIU; QI, ZHAN; WU, DI; CAO, BINGYAN

    2015-01-01

    Allgrove syndrome (AS) is an autosomal recessive congenital disease, caused by mutations in the AAAS gene, and is characterized by the triad of Addison's disease, achalasia and alacrima. The present study describes three newly diagnosed cases of AS, in which genetic analysis of the AAAS gene was used to identify AAAS gene mutations, to enhance the understanding of the pathogenesis and clinical manifestations of AS in the Chinese population. Two of the cases exhibited homozygous mutations of c.771delG (p.Arg258GlyfsX33) in exon 8 and one case exhibited a homozygous mutation of c.1366C>T (p.Q456X) in exon 15. A review of the current literature suggests that the AAAS c.771delG mutation has only been reported in the Chinese population. Genetic analysis of the AAAS gene in Chinese AS patients at a young age may facilitate an earlier diagnosis and the timely initiation of the appropriate treatment, ultimately improving the patient outcome. PMID:26622478

  20. Temporary extra-anatomic brain perfusion followed by total rerouting of the supra-aortic vessels for hybrid repair of a ruptured aortic arch aneurysm.

    PubMed

    Joyeux, Frederic; Canaud, Ludovic; Hireche, Kheira; Berthet, Jean-Philippe; Marty-Ane, Charles; Alric, Pierre

    2011-10-01

    Hybrid repair of ruptured aortic arch repair has been proposed as a valuable approach. However, the presence of an anterior mediastinal hematoma must be carefully detected because of the inherent risk of rupture at sternotomy. We report the case of a patient presenting a ruptured aortic arch aneurysm with anterior rupture who underwent hybrid repair using a temporary extra-anatomic brain perfusion followed by total rerouting of the supra-aortic trunks. We propose this adjunctive technique as a means of allowing a safe endovascular exclusion of aortic arch lesions and avoiding the risk of acute and total aortic rupture in case of anterior rupture of aortic arch aneurysms.

  1. Dynein motors: How AAA+ ring opening and closing coordinates microtubule binding and linker movement.

    PubMed

    Schmidt, Helgo

    2015-05-01

    Dyneins are a family of motor proteins that move along the microtubule. Motility is generated in the motor domain, which consists of a ring of six AAA+ (ATPases associated with diverse cellular activities) domains, the linker and the microtubule-binding domain (MTBD). The cyclic ATP-hydrolysis in the AAA+ ring causes the remodelling of the linker, which creates the necessary force for movement. The production of force has to be synchronized with cycles of microtubule detachment and rebinding to efficiently create movement along the microtubule. The analysis of four dynein motor domain crystal structures in the essay presented here provides evidence that this crucial coordination is carried out by open/closed AAA+ ring conformations.

  2. Cell-Activation by Shear Stresses in Abdominal Aortic Aneurysms (AAA)

    NASA Astrophysics Data System (ADS)

    Salsac, Anne-Virginie; Sparks, Steven; Chomaz, Jean-Marc; Lasheras, Juan C.

    2003-11-01

    Increasing experimental evidence indicates that low and oscillatory shear stresses promote proliferative, thrombotic, adhesive and inflammatory-mediated degenerative conditions throughout the wall of the aorta. These degenerative conditions have been shown to be involved in the pathogenesis of AAAs, a permanent, localized dilatation of the abdominal aorta. The purpose of this study is to measure both the magnitude and the duration of the shear stresses acting on both the arterial walls and on the blood cells inside AAAs, and to characterize their changes as the AAA enlarges. We conducted a parametric in-vitro study of the pulsatile blood flow in elastic models of AAAs while systematically varying the blood flow parameters, and the geometry of the aneurysm's bulging. The instantaneous flow characteristic inside the AAA was measured using DPIV at a sampling rate of 15 Hertz. A "cell-activation parameter" defined as the integral of the product of the magnitude of the shear stress and the time during which the stress acts was computed along each of the blood cell pathlines. The Lagrangian tracking of the blood cells shows that a large majority of them are subjected first to very high level of shear-induced "cell-activation" while later on they are entrained in regions of stasis where their residence time can increase up to several cardiac cycles. This cell-activation followed by the entrainment in low shear regions creates the optimal cell-adhesive and inflammatory-mediated degenerative conditions that are postulated to play an important role in the etiology and progressive enlargement of AAAs.

  3. Achilles tendon rupture rehabilitation

    PubMed Central

    Kearney, R. S.; Parsons, N.; Underwood, M.; Costa, M. L.

    2015-01-01

    Objectives The evidence base to inform the management of Achilles tendon rupture is sparse. The objectives of this research were to establish what current practice is in the United Kingdom and explore clinicians’ views on proposed further research in this area. This study was registered with the ISRCTN (ISRCTN68273773) as part of a larger programme of research. Methods We report an online survey of current practice in the United Kingdom, approved by the British Orthopaedic Foot and Ankle Society and completed by 181 of its members. A total of ten of these respondents were invited for a subsequent one-to-one interview to explore clinician views on proposed further research in this area. Results The survey showed wide variations in practice, with patients being managed in plaster cast alone (13%), plaster cast followed by orthoses management (68%), and orthoses alone (19%). Within these categories, further variation existed regarding the individual rehabilitation facets, such as the length of time worn, the foot position within them and weight-bearing status. The subsequent interviews reflected this clinical uncertainty and the pressing need for definitive research. Conclusions The gap in evidence in this area has resulted in practice in the United Kingdom becoming varied and based on individual opinion. Future high-quality randomised trials on this subject are supported by the clinical community. Cite this article: Bone Joint Res 2015;4:65–9 PMID:25868938

  4. IL-1β, IL-6 promoter, TNF-α promoter and IL-1RA gene polymorphisms and the risk of preterm delivery due to preterm premature rupture of membranes in a population of Polish women

    PubMed Central

    Kalinka, Jaroslaw

    2010-01-01

    Introduction Our previous study revealed that anti-inflammatory cytokine gene polymorphisms increase the risk of spontaneous preterm delivery (PD) in a population of Polish women. Different genetic background of PD due to preterm premature rupture of membranes (pPROM) than PD without pPROM has been suggested. The aim of this study was to examine the relationship between the maternal carriage of polymorphic alleles of the following genes: interleukin 1β(IL-1β [+3953C>T]), interleukin 6 promoter (IL-6 [−174G>C]), tumour necrosis factor promoter (TNF-α [–308G>A]) and interleukin 1 receptor antagonist (IL-1RN) and the risk of PD caused exclusively by pPROM in a population of Polish women. Material and methods A case-control study. 95 Caucasian women were examined including 32 cases and 63 controls. Case subjects experienced a delivery at less than 36 weeks and 6 days of gestation due exclusively to pPROM while control subjects gave birth at term. Polymorphisms were determined by polymerase chain reaction-restriction fragment length polymorphism analysis (PCR-RFLP). Results No statistically significant relationship between polymorphisms of examined genes and risk of PD due to pPROM in a population of Polish women was found: OR = 0.84 (95% CI: 0.34-2.01) for IL-1β, OR = 0.77 (95% CI: 0.27-2.13) for IL-6, OR = 0.72 (95% CI: 0.26-1.90) for TNF-α and OR = 1.74 (95% CI: 0.66-4.64) for IL-1RN. Conclusions Maternal carriage of polymorphic alleles of IL-1β, IL-6 promoter, TNF-α promoter and IL-1RA seems to have no impact on the risk of PD due to pPROM in the population of Polish women.The genetic contribution and pathomechanism of PD related to pPROM seems to differ from those of spontaneous PD without pPROM. PMID:22371799

  5. Blood vessel rupture by cavitation

    PubMed Central

    Chen, Hong; Brayman, Andrew A.; Bailey, Michael R.

    2011-01-01

    Cavitation is thought to be one mechanism for vessel rupture during shock wave lithotripsy treatment. However, just how cavitation induces vessel rupture remains unknown. In this work, a high-speed photomicrography system was set up to directly observe the dynamics of bubbles inside blood vessels in ex vivo rat mesenteries. Vascular rupture correlating to observed bubble dynamics were examined by imaging bubble extravasation and dye leakage. The high-speed images show that bubble expansion can cause vessel distention, and bubble collapse can lead to vessel invagination. Liquid jets were also observed to form. Our results suggest that all three mechanisms, vessel distention, invagination and liquid jets, can contribute to vessel rupture. PMID:20680255

  6. Multiple branching rupture of the 2009 Tonga-Samoa earthquake

    NASA Astrophysics Data System (ADS)

    Fan, Wenyuan; Shearer, Peter M.; Ji, Chen; Bassett, Dan

    2016-08-01

    Several source models have been proposed to explain the enigmatic 2009 Tonga-Samoa earthquake. The long-period data require a composite source model and can be fit with a normal-faulting subevent followed by one or more reverse-faulting subevents. The short-period data, in contrast, indicate a more compact rupture pattern around the epicenter. The lack of a unified source model reflects the complexity of the event. We analyze the spatiotemporal evolution of this earthquake with P wave back-projection from globally distributed stations in different frequency bands (low frequency: 0.05-0.2 Hz, high frequency: 0.2-2 Hz) and a multiple moment tensor inversion. The rupture propagation revealed by back-projection exhibits frequency-dependent behavior, with two branches of high-frequency-enriched bilateral rupture around the epicenter and a high-frequency-deficient rupture branch at the subduction interface. A composite source model with one Mw 8.0 normal-faulting earthquake east of the trench axis (seaward) followed by one Mw 8.1 reverse-faulting earthquake along the subduction interface west of the trench axis (landward) can explain the very long period data (200˜500 s). Combined with high-resolution swath bathymetry data, the back-projection images show that the azimuth of rupture branches east of the trench axis were controlled by the geometry of bending-related faults on the Pacific plate and that the rupture branch west of the trench axis may correlate with the along-strike fore-arc segmentation. The rupture along the subduction interface was triggered by the seaward rupture and a partially subducted normal fault may have played a key role in facilitating the triggering. The apparent normal-reverse faulting interactions pose a higher seismic risk to this region than their individual strands at the northernmost corner of the Tonga subduction zone.

  7. The ruptured PIP breast implant.

    PubMed

    Helyar, V; Burke, C; McWilliams, S

    2013-08-01

    Public concern erupted about the safety of Poly Implant Prothèse (PIP) breast implants when it was revealed in 2011 that they contained an inferior, unlicensed industrial-grade silicone associated with a high rate of rupture. There followed national guidance for UK clinicians, which led to a considerable increase in referrals of asymptomatic women for breast implant assessment. In this review we discuss possible approaches to screening the PIP cohort and the salient characteristics of a ruptured implant. PMID:23622796

  8. Contemporary Diagnosis and Management of Preterm Premature Rupture of Membranes

    PubMed Central

    Caughey, Aaron B; Robinson, Julian N; Norwitz, Errol R

    2008-01-01

    Spontaneous rupture of membranes (ROM) is a normal component of labor and delivery. Premature ROM (PROM) refers to rupture of the fetal membranes prior to the onset of labor irrespective of gestational age. Once the membranes rupture, delivery is recommended when the risk of ascending infection outweighs the risk of prematurity. When PROM occurs at term, labor typically ensues spontaneously or is induced within 12 to 24 hours. The management of pregnancies complicated by preterm PROM (defined as PROM occurring prior to 37 weeks of gestation) is more challenging. Preterm PROM complicates 2% to 20% of all deliveries and is associated with 18% to 20% of perinatal deaths. Management options include admission to hospital, amniocentesis to exclude intra-amniotic infection, and administration of antenatal corticosteroids and broad-spectrum antibiotics, if indicated. This article reviews in detail the contemporary diagnosis and management of preterm PROM. PMID:18701929

  9. Earthquake rupture extents and coseismic slips promoted by damaged fault zones

    NASA Astrophysics Data System (ADS)

    Weng, Huihui; Yang, Hongfeng; Zhang, Zhenguo; Chen, Xiaofei

    2016-06-01

    Here we investigate the effects of damage fault zones on rupture propagation by conducting a series of 3-D dynamic rupture simulations on a planar vertical strike-slip fault. We find that damage fault zones can promote rupture extent and increase earthquake potency. The waves reflected from the bottom of shallow damage fault zones can increase shear stress on the fault and thus promote rupture propagation. In addition, the promotional effects increase with the width and depth extent of damage fault zones. The overall effects of the waves reflected from the fault-parallel side boundaries of damage fault zones are unfavorable for rupture propagation. Therefore, rupture propagation is promoted with the increased width of fault zones due to geometrical spreading effects. Moreover, nonground-breaking ruptures may reach the ground surface with the effects of damage fault zones. Furthermore, along-strike segmented fault zones as suggested by observations could also promote ruptures and may lead to preferred rupture directions if epicenters are close to fault zones. The effects of damage fault zones on rupture propagation hold important implications on assessing earthquake risk.

  10. Spontaneous prelabor uterine rupture in a primigravida: a case report and review of the literature.

    PubMed

    Uccella, Stefano; Cromi, Antonella; Bogani, Giorgio; Zaffaroni, Eleonora; Ghezzi, Fabio

    2011-11-01

    A rare case of prelabor uterine rupture in a primigravida was reported. A woman with a history of uterine perforation during hysteroscopy became pregnant after donor oocyte in vitro fertilization. To provide more insight into the possible risk factors for prelabor uterine rupture in primigravidae, a literature review was performed.

  11. Bladder rupture associated with uterine rupture at delivery.

    PubMed

    Yang, Bo

    2011-05-01

    This paper seeks to study the clinical presentation and emergency treatment of bladder rupture associated with uterine rupture at delivery. From June to December 2009, three cases of rupture of the uterus involving maternal bladder during labor at Revolutionary Hospital at Hodeidah, Yemen were reviewed. Intraoperatively, it appeared that the posterior wall of the bladder and the anterior wall of the uterus had ruptured; the laceration of the posterior bladder wall was closed in two layers. Of the patients who underwent the operations, one patient developed vesicovaginal fistula, which was repaired vaginally after 6 months, and the patient had a successful outcome. The others got uneventful recovery and there was no vesicovaginal fistula or hydronephrosis during follow-up. Uterine rupture and associated injury to the maternal bladder was rarely reported. It would be life threatening or would lead to long-term complications. Both urologists and obstetrician should keep bladder injuries in mind, as serious outcomes might occur during labor. Surgical treatment could be the preferred approach for this situation.

  12. Norwalk Community College AA-AS Degree Review Committee Curriculum Report, August 21, 1989.

    ERIC Educational Resources Information Center

    Pennino, Eileen M.; Luster, Gwen Tolliver

    In an attempt to revitalize and reform its curriculum, the Associate of Arts-Associate of Science (AA-AS) Degree Review Committee (DRC) of Connecticut's Norwalk Community College issued a curriculum report proposing a 21 credit, limited distributive core for the AS degree (which accounts for 80% of the college's degree recipients). This proposal…

  13. Professional Ethics Activities in the Scientific and Engineering Societies. AAAS Professional Ethics Project.

    ERIC Educational Resources Information Center

    Chalk, Rosemary; And Others

    Presented is an overview of the depth and range of the ethics activities undertaken by societies affiliated with the American Association for the Advancement of Science (AAAS). Included in this report are: (1) reviews of previous surveys of organizations which had adopted codes of ethics; (2) descriptions of the methodology and findings of the…

  14. Fluid Characteristics in Abdominal Aortic Aneurysms (AAAs) and Its Correlation to Thrombus Formation

    NASA Astrophysics Data System (ADS)

    Tang, Rubing; Bar-Yoseph, Pinhas Z.; Lasheras, Juan

    2008-11-01

    It has been observed that most large Abdominal Aortic Aneurysms (AAAs) develop an intraluminal thrombus as they progressively enlarge. Previous studies have suggested that the build up of the thrombus may be associated with the altered hemodynamic patterns that arise inside the AAA. We have performed a parametrical computational study of the flow patterns inside enlarging AAA to investigate the possible mechanism controlling the thrombus formation. Pulsatile blood flows were simulated in idealized models of fusiform aneurysms with different dilatation ratios and the effects of shear-activated platelet accumulation and platelet/wall interaction were evaluated based on the calculated flow fields. The platelet activation level (PAL) was determined by computing the integral over time of flow shear stresses exerted over the platelets as they are transported throughout the aneurysm. Our results have shown that the values of PAL in AAAs are in fact smaller than the maximum value obtained in a healthy abdominal aorta. However, we show that the transportation of blood cells towards the wall and the formation of stagnation points on the aneurysm's wall play more significant roles in thrombus formation than PAL.

  15. Effects of doping and bias voltage on the screening in AAA-stacked trilayer graphene

    NASA Astrophysics Data System (ADS)

    Mohammadi, Yawar; Moradian, Rostam; Shirzadi Tabar, Farzad

    2014-09-01

    We calculate the static polarization of AAA-stacked trilayer graphene (TLG) and study its screening properties within the random phase approximation (RPA) in all undoped, doped and biased regimes. We find that the static polarization of undoped AAA-stacked TLG is a combination of the doped and undoped single-layer graphene static polarization. This leads to an enhancement of the dielectric background constant along a Thomas-Fermi screening with the Thomas-Fermi wave vector which is independent of carrier concentrations and a 1/r3 power law decay for the long-distance behavior of the screened Coulomb potential. We show that effects of a bias voltage can be taken into account by a renormalization of the interlayer hopping energy to a new bias-voltage-dependent value, indicating screening properties of AAA-stacked TLG can be tuned electrically. We also find that screening properties of doped AAA-stacked TLG, when μ exceeds √{2}γ, are similar to that of doped SLG only depending on doping. While for μ<√{2}γ, its screening properties are combination of SLG and AA-stacked bilayer graphene screening properties and they are determined by doping and the interlayer hopping energy.

  16. Structure of Lmaj006129AAA, a hypothetical protein from Leishmania major

    SciTech Connect

    Arakaki, Tracy; Le Trong, Isolde; Phizicky, Eric; Quartley, Erin; DeTitta, George; Luft, Joseph; Lauricella, Angela; Anderson, Lori; Kalyuzhniy, Oleksandr; Worthey, Elizabeth; Myler, Peter J.; Kim, David; Baker, David; Hol, Wim G. J.; Merritt, Ethan A.

    2006-03-01

    The crystal structure of a conserved hypothetical protein from L. major, Pfam sequence family PF04543, structural genomics target ID Lmaj006129AAA, has been determined at a resolution of 1.6 Å. The gene product of structural genomics target Lmaj006129 from Leishmania major codes for a 164-residue protein of unknown function. When SeMet expression of the full-length gene product failed, several truncation variants were created with the aid of Ginzu, a domain-prediction method. 11 truncations were selected for expression, purification and crystallization based upon secondary-structure elements and disorder. The structure of one of these variants, Lmaj006129AAH, was solved by multiple-wavelength anomalous diffraction (MAD) using ELVES, an automatic protein crystal structure-determination system. This model was then successfully used as a molecular-replacement probe for the parent full-length target, Lmaj006129AAA. The final structure of Lmaj006129AAA was refined to an R value of 0.185 (R{sub free} = 0.229) at 1.60 Å resolution. Structure and sequence comparisons based on Lmaj006129AAA suggest that proteins belonging to Pfam sequence families PF04543 and PF01878 may share a common ligand-binding motif.

  17. The two faces of hydrogen-bond strength on triple AAA-DDD arrays.

    PubMed

    Lopez, Alfredo Henrique Duarte; Caramori, Giovanni Finoto; Coimbra, Daniel Fernando; Parreira, Renato Luis Tame; da Silva, Éder Henrique

    2013-12-01

    Systems that are connected through multiple hydrogen bonds are the cornerstone of molecular recognition processes in biology, and they are increasingly being employed in supramolecular chemistry, specifically in molecular self-assembly processes. For this reason, the effects of different substituents (NO2, CN, F, Cl, Br, OCH3 and NH2) on the electronic structure, and consequently on the magnitude of hydrogen bonds in triple AAA-DDD arrays (A=acceptor, D=donor) were evaluated in the light of topological [electron localization function (ELF) and quantum theory of atoms in molecules (QTAIM)], energetic [Su-Li energy-decomposition analysis (EDA) and natural bond orbital analysis (NBO)], and geometrical analysis. The results based on local H-bond descriptors (geometries, QTAIM, ELF, and NBO) indicate that substitutions with electron-withdrawing groups on the AAA module tend to strengthen, whereas electron-donating substituents tend to weaken the covalent character of the AAA-DDD intermolecular H-bonds, and also indicate that the magnitude of the effect is dependent on the position of substitution. In contrast, Su-Li EDA results show an opposite behavior when compared to local H-bond descriptors, indicating that electron-donating substituents tend to increase the magnitude of H-bonds in AAA-DDD arrays, and thus suggesting that the use of local H-bond descriptors describes the nature of H bonds only partially, not providing enough insight about the strength of such H bonds.

  18. Anonymous Communication Policies for the Internet: Results and Recommendations of the AAAS Conference.

    ERIC Educational Resources Information Center

    Teich, Al; Frankel, Mark S.; Kling, Rob; Lee, Yaching

    1999-01-01

    Reports the results of a conference on the Internet and anonymous communication organized by the American Association for the Advancement of Science (AAAS). Discusses how anonymous communications can be shaped by the law, education, and public awareness, and highlights the importance of involving all affected interests in policy development.…

  19. The mouse fidgetin gene defines a new role for AAA family proteins in mammalian development.

    PubMed

    Cox, G A; Mahaffey, C L; Nystuen, A; Letts, V A; Frankel, W N

    2000-10-01

    The mouse mutation fidget arose spontaneously in a heterogeneous albino stock. This mutant mouse is characterized by a side-to-side head-shaking and circling behaviour, due to reduced or absent semicircular canals. Fidget mice also have small eyes, associated with cell-cycle delay and insufficient growth of the retinal neural epithelium, and lower penetrance skeletal abnormalities, including pelvic girdle dysgenesis, skull bone fusions and polydactyly. By positional cloning, we found the gene mutated in fidget mice, fidgetin (Fign), which encodes a new member of the 'meiotic' or subfamily-7 (SF7; ref. 7) group of ATPases associated with diverse cellular activities (AAA proteins). We also discovered two closely related mammalian genes. AAA proteins are molecular chaperones that facilitate a variety of functions, including membrane fusion, proteolysis, peroxisome biogenesis, endosome sorting and meiotic spindle formation, but functions for the SF7 AAA proteins are largely unknown. Fidgetin is the first mutant AAA protein found in a mammalian developmental mutant, thus defining a new role for these proteins in embryonic development.

  20. National dosimetric audit network finds discrepancies in AAA lung inhomogeneity corrections.

    PubMed

    Dunn, Leon; Lehmann, Joerg; Lye, Jessica; Kenny, John; Kron, Tomas; Alves, Andrew; Cole, Andrew; Zifodya, Jackson; Williams, Ivan

    2015-07-01

    This work presents the Australian Clinical Dosimetry Service's (ACDS) findings of an investigation of systematic discrepancies between treatment planning system (TPS) calculated and measured audit doses. Specifically, a comparison between the Anisotropic Analytic Algorithm (AAA) and other common dose-calculation algorithms in regions downstream (≥2cm) from low-density material in anthropomorphic and slab phantom geometries is presented. Two measurement setups involving rectilinear slab-phantoms (ACDS Level II audit) and anthropomorphic geometries (ACDS Level III audit) were used in conjunction with ion chamber (planar 2D array and Farmer-type) measurements. Measured doses were compared to calculated doses for a variety of cases, with and without the presence of inhomogeneities and beam-modifiers in 71 audits. Results demonstrate a systematic AAA underdose with an average discrepancy of 2.9 ± 1.2% when the AAA algorithm is implemented in regions distal from lung-tissue interfaces, when lateral beams are used with anthropomorphic phantoms. This systemic discrepancy was found for all Level III audits of facilities using the AAA algorithm. This discrepancy is not seen when identical measurements are compared for other common dose-calculation algorithms (average discrepancy -0.4 ± 1.7%), including the Acuros XB algorithm also available with the Eclipse TPS. For slab phantom geometries (Level II audits), with similar measurement points downstream from inhomogeneities this discrepancy is also not seen. PMID:25921329

  1. Asymmetric processing of a substrate protein in sequential allosteric cycles of AAA+ nanomachines

    NASA Astrophysics Data System (ADS)

    Kravats, Andrea N.; Tonddast-Navaei, Sam; Bucher, Ryan J.; Stan, George

    2013-09-01

    Essential protein quality control includes mechanisms of substrate protein (SP) unfolding and translocation performed by powerful ring-shaped AAA+ (ATPases associated with various cellular activities) nanomachines. These SP remodeling actions are effected by mechanical forces imparted by AAA+ loops that protrude into the central channel. Sequential intra-ring allosteric motions, which underlie repetitive SP-loop interactions, have been proposed to comprise clockwise (CW), counterclockwise (CCW), or random (R) conformational transitions of individual AAA+ subunits. To probe the effect of these allosteric mechanisms on unfoldase and translocase functions, we perform Langevin dynamics simulations of a coarse-grained model of an all-alpha SP processed by the single-ring ClpY ATPase or by the double-ring p97 ATPase. We find that, in all three allosteric mechanisms, the SP undergoes conformational transitions along a common set of pathways, which reveals that the active work provided by the ClpY machine involves single loop-SP interactions. Nevertheless, the rates and yields of SP unfolding and translocation are controlled by mechanism-dependent loop-SP binding events, as illustrated by faster timescales of SP processing in CW allostery compared with CCW and R allostery. The distinct efficacy of allosteric mechanisms is due to the asymmetric collaboration of adjacent subunits, which involves CW-biased structural motions of AAA+ loops and results in CW-compatible torque applied onto the SP. Additional simulations of mutant ClpY rings, which render a subset of subunits catalytically-defective or reduce their SP binding affinity, reveal that subunit-based conformational transitions play the major role in SP remodeling. Based on these results we predict that the minimally functional AAA+ ring includes three active subunits, only two of which are adjacent.

  2. Asymmetric processing of a substrate protein in sequential allosteric cycles of AAA+ nanomachines.

    PubMed

    Kravats, Andrea N; Tonddast-Navaei, Sam; Bucher, Ryan J; Stan, George

    2013-09-28

    Essential protein quality control includes mechanisms of substrate protein (SP) unfolding and translocation performed by powerful ring-shaped AAA+ (ATPases associated with various cellular activities) nanomachines. These SP remodeling actions are effected by mechanical forces imparted by AAA+ loops that protrude into the central channel. Sequential intra-ring allosteric motions, which underlie repetitive SP-loop interactions, have been proposed to comprise clockwise (CW), counterclockwise (CCW), or random (R) conformational transitions of individual AAA+ subunits. To probe the effect of these allosteric mechanisms on unfoldase and translocase functions, we perform Langevin dynamics simulations of a coarse-grained model of an all-alpha SP processed by the single-ring ClpY ATPase or by the double-ring p97 ATPase. We find that, in all three allosteric mechanisms, the SP undergoes conformational transitions along a common set of pathways, which reveals that the active work provided by the ClpY machine involves single loop-SP interactions. Nevertheless, the rates and yields of SP unfolding and translocation are controlled by mechanism-dependent loop-SP binding events, as illustrated by faster timescales of SP processing in CW allostery compared with CCW and R allostery. The distinct efficacy of allosteric mechanisms is due to the asymmetric collaboration of adjacent subunits, which involves CW-biased structural motions of AAA+ loops and results in CW-compatible torque applied onto the SP. Additional simulations of mutant ClpY rings, which render a subset of subunits catalytically-defective or reduce their SP binding affinity, reveal that subunit-based conformational transitions play the major role in SP remodeling. Based on these results we predict that the minimally functional AAA+ ring includes three active subunits, only two of which are adjacent.

  3. Transcatheter closure of ruptured sinus Valsalva aneurysm with retrograde approach.

    PubMed

    Narin, Nazmi; Ozyurt, Abdullah; Baykan, Ali; Uzüm, Kazım

    2014-04-01

    A three-year-old girl with multiple heart malformations admitted to the pediatric cardiology unit because of excessive sweating and fatigue. Abnormal color Doppler flow was detected into the right atrium from the dilated coronary sinus on the echocardiographic examination, and ruptured sinus Valsalva aneurysm (SVA) was diagnosed. Although in most such cases, an antegrade transcatheter approach has been used, a retrograde approach can be used as a cost-effective treatment modality in those cases with selective high-risk surgery. In this report, we present a patient with ruptured SVA, which was closed via Amplatzer vascular plug-4 by retrograde approach. PMID:24769826

  4. Spontaneous Liver Rupture After Treatment With Drug-Eluting Beads

    SciTech Connect

    Ritter, C. O.; Wartenberg, M.; Mottok, A.; Steger, U.; Goltz, J. P.; Hahn, D.; Kickuth, R.

    2012-02-15

    Spontaneous rupture of hepatocellular carcinoma (HCC) after transcatheter arterial chemoembolization (TACE) is a rare and life-threatening complication. Pathophysiologic mechanisms are not yet fully known; it is suggested that rupture is preceded by reactive tissue edema and intratumerous bleeding, leading to a rapid expansion of tumour mass with risk of extrahepatic bleeding in the case of subcapsular localisation. This case report discusses a sudden, unexpected lethal complication in a 74 year-old male patient treated with TACE using DC Bead loaded with doxorubicin (DEBDOX) in a progressive multifocal HCC.

  5. Spontaneous rupture of the ureter.

    PubMed

    Eken, Alper; Akbas, Tugana; Arpaci, Taner

    2015-02-01

    Spontaneous rupture of the ureter is a very rare condition and usually results from ureteral obstruction by a calculus. Only theoretical mechanisms have been proposed and no possible explanation has yet been reported in the literature. Intravenous contrast-enhanced computed tomography is the most informative study with high sensitivity. Treatment should be individualised, and depends on the state of the patient. Minimally invasive endourological procedures with double-J catheter placement and percutaneous drainage offer excellent results. Conservative management with analgesics and antibiotic coverage may be an alternative to surgery. Herein, we present a case of spontaneous rupture of the proximal ureter with no evidence of an underlying pathological condition.

  6. Enzymatically triggered rupture of polymersomes.

    PubMed

    Jang, Woo-Sik; Park, Seung Chul; Reed, Ellen H; Dooley, Kevin P; Wheeler, Samuel F; Lee, Daeyeon; Hammer, Daniel A

    2016-01-28

    Polymersomes are robust vesicles made from amphiphilic block co-polymers. Large populations of uniform giant polymersomes with defined, entrapped species can be made by templating of double-emulsions using microfluidics. In the present study, a series of two enzymatic reactions, one inside and the other outside of the polymersome, were designed to induce rupture of polymersomes. We measured how the kinetics of rupture were affected by altering enzyme concentration. These results suggest that protocells with entrapped enzymes can be engineered to secrete contents on cue.

  7. Rupture of adductor longus tendon due to ciprofloxacin.

    PubMed

    Mouzopoulos, George; Stamatakos, Mihalis; Vasiliadis, George; Skandalakis, Panagiotis

    2005-12-01

    We present a rare case of spontaneous rupture of the adductor longus tendon induced by ciprofloxacin. A 35-year-old man was diagnosed with pneumonia and was recommended ciprofloxacin 500 mg iv twice a day for 7 days. Three days after receiving the initial dose, he developed discomfort in his left medial thigh, and pain and swelling in the same area followed ten days later. He consulted us when he noted a palpable mass on the medial side of his left thigh, and MRI study revealed adductor longus tendon rupture. There was no obvious underlying disease or other factor causing fragility of his adductor longus tendon. We review the pathophysiological mechanisms leading to fluoroquinolone-related tendon rupture as well as the risk factors and discuss proper management.

  8. Complicated malaria and a covert ruptured spleen: a case report.

    PubMed

    Waweru, Peter; Macleod, Jana; Gikonyo, Anthony

    2014-01-01

    Spontaneous splenic rupture in complicated malaria is an uncommon cause of hemoperitoneum in the tropics. The exact incidence of splenic rupture is unknown, largely due to under-reporting, but has been estimated at ∼2%. Its pathophysiology is linked to the formation of a subcapsular hematoma. Upon rupture, patients present with features of shock and peritonitis and in most cases (95%), computed tomography (CT) scan detects the splenic injury. Patients should be managed conservatively with splenectomy reserved for patients with shock and hemoperitoneum due to risk of post-splenectomy sepsis. We report the case of a 38-year-old man with severe malaria who presented with fever, chills and abdominal pains. A CT scan abdomen failed to reveal splenic parenchymal injury or any splenic extravasation of contrast. Conservative management was unsuccessful. Exploratory laparatomy confirmed the spleen as the site of bleeding necessitating a splenectomy. PMID:25395608

  9. Complicated malaria and a covert ruptured spleen: a case report.

    PubMed

    Waweru, Peter; Macleod, Jana; Gikonyo, Anthony

    2014-11-13

    Spontaneous splenic rupture in complicated malaria is an uncommon cause of hemoperitoneum in the tropics. The exact incidence of splenic rupture is unknown, largely due to under-reporting, but has been estimated at ∼2%. Its pathophysiology is linked to the formation of a subcapsular hematoma. Upon rupture, patients present with features of shock and peritonitis and in most cases (95%), computed tomography (CT) scan detects the splenic injury. Patients should be managed conservatively with splenectomy reserved for patients with shock and hemoperitoneum due to risk of post-splenectomy sepsis. We report the case of a 38-year-old man with severe malaria who presented with fever, chills and abdominal pains. A CT scan abdomen failed to reveal splenic parenchymal injury or any splenic extravasation of contrast. Conservative management was unsuccessful. Exploratory laparatomy confirmed the spleen as the site of bleeding necessitating a splenectomy.

  10. Treatment of Ruptured Vertebral Artery Dissecting Aneurysms

    PubMed Central

    Hamasaki, Osamu; Ikawa, Fusao; Hidaka, Toshikazu; Kurokawa, Yasuharu; Yonezawa, Ushio

    2014-01-01

    Summary We evaluated the outcomes of endovascular or surgical treatment of ruptured vertebral artery dissecting aneurysms (VADAs), and investigated the relations between treatment complications and the development and location of the posterior inferior cerebellar artery (PICA). We treated 14 patients (12 men, two women; mean age, 56.2 years) with ruptured VADAs between March 1999 and June 2012 at our hospital. Six and eight patients had Hunt and Hess grades 1-3 and 4-5, respectively. Twelve patients underwent internal endovascular trapping, one underwent proximal endovascular occlusion alone, and one underwent proximal endovascular occlusion in the acute stage and occipital artery (OA)-PICA anastomosis and surgical trapping in the chronic stage. The types of VADA based on their location relative to the ipsilateral PICA were distal, PICA-involved, and non-PICA in nine, two, and three patients, respectively. The types of PICA based on their development and location were bilateral anterior inferior cerebellar artery (AICA)-PICA, ipsilateral AICA-PICA, extradural, and intradural type in one, two, two, and nine patients, respectively. Two patients with high anatomical risk developed medullary infarction, but their midterm outcomes were better than in previous reports. The modified Rankin scale indicated grades 0-2, 3-5, and 6 in eight, three, and three patients, respectively. A good outcome is often obtained in the treatment of ruptured VADA using internal endovascular trapping, except in the PICA-involved type, even with high-grade subarachnoid hemorrhage. Treatment of the PICA-involved type is controversial. The anatomical location and development of PICA may be predicted by complications with postoperative medullary infarction. PMID:24976093

  11. Vortex dynamics in ruptured and unruptured intracranial aneurysms

    NASA Astrophysics Data System (ADS)

    Trylesinski, Gabriel

    Intracranial aneurysms (IAs) are a potentially devastating pathological dilation of brain arteries that affect 1.5-5 % of the population. Causing around 500 000 deaths per year worldwide, their detection and treatment to prevent rupture is critical. Multiple recent studies have tried to find a hemodynamics predictor of aneurysm rupture, but concluded with distinct opposite trends using Wall Shear Stress (WSS) based parameters in different clinical datasets. Nevertheless, several research groups tend to converge for now on the fact that the flow patterns and flow dynamics of the ruptured aneurysms are complex and unstable. Following this idea, we investigated the vortex properties of both unruptured and ruptured cerebral aneurysms. A brief comparison of two Eulerian vortex visualization methods (Q-criterion and lambda 2 method) showed that these approaches gave similar results in our complex aneurysm geometries. We were then able to apply either one of them to a large dataset of 74 patient specific cases of intracranial aneurysms. Those real cases were obtained by 3D angiography, numerical reconstruction of the geometry, and then pulsatile CFD simulation before post-processing with the mentioned vortex visualization tools. First we tested the two Eulerian methods on a few cases to verify their implementation we made as well as compare them with each other. After that, the Q-criterion was selected as method of choice for its more obvious physical meaning (it shows the balance between two characteristics of the flow, its swirling and deformation). Using iso-surfaces of Q, we started by categorizing the patient-specific aneurysms based on the gross topology of the aneurysmal vortices. This approach being unfruitful, we found a new vortex-based characteristic property of ruptured aneurysms to stratify the rupture risk of IAs that we called the Wall-Kissing Vortices, or WKV. We observed that most ruptured aneurysms had a large amount of WKV, which appears to agree with

  12. Spontaneous rupture of spleen in falciparum malaria.

    PubMed

    Vidyashankar, C; Basu, Arup; Kulkarni, A R; Choudhury, R K

    2003-01-01

    Spontaneous rupture of spleen is an extremely rare complication of falciparum malaria. We report a 3 1/2-year-old girl with splenic rupture who was managed successfully with splenectomy and antimalarials.

  13. Spontaneous bilateral quadriceps tendon rupture.

    PubMed

    Vigneswaran, N; Lee, K; Yegappan, M

    2007-11-01

    Spontaneous bilateral quadriceps tendon ruptures are uncommon. We present a 30-year-old man with end-stage renal failure, who sustained this injury, and subsequently had surgical repair of both tendons on separate occasions. He has since regained full range of movement of both knees.

  14. Quadriceps Tendon Rupture due to Postepileptic Convulsion

    PubMed Central

    Erkut, Adem; Guvercin, Yilmaz; Sahin, Rifat; Keskin, Davut

    2014-01-01

    We present a case of quadriceps tendon (QT) rupture. QT ruptures can occur in all ages. The cause is mostly traumatic in origin. Spontaneous ruptures that are thought to result from predisposing conditions are rare. Post-convulsion QT ruptures lacking traumas in their history can be overlooked in clinical examinations. This should be born in mind by the attending physician, as early diagnosis and treatment of the condition can lead to satisfactory outcomes. PMID:24944977

  15. SFM-FDTD analysis of triangular-lattice AAA structure: Parametric study of the TEM mode

    NASA Astrophysics Data System (ADS)

    Hamidi, M.; Chemrouk, C.; Belkhir, A.; Kebci, Z.; Ndao, A.; Lamrous, O.; Baida, F. I.

    2014-05-01

    This theoretical work reports a parametric study of enhanced transmission through annular aperture array (AAA) structure arranged in a triangular lattice. The effect of the incidence angle in addition to the inner and outer radii values on the evolution of the transmission spectra is carried out. To this end, a 3D Finite-Difference Time-Domain code based on the Split Field Method (SFM) is used to calculate the spectral response of the structure for any angle of incidence. In order to work through an orthogonal unit cell which presents the advantage to reduce time and space of computation, special periodic boundary conditions are implemented. This study provides a new modeling of AAA structures useful for producing tunable ultra-compact devices.

  16. Substituent effects in double-helical hydrogen-bonded AAA-DDD complexes.

    PubMed

    Wang, Hong-Bo; Mudraboyina, Bhanu P; Wisner, James A

    2012-01-27

    Two series of DDD and AAA hydrogen-bond arrays were synthesized that form triply-hydrogen-bonded double-helical complexes when combined in CDCl(3) solution. Derivatization of the DDD arrays with electron-withdrawing groups increases the complex association constants by up to a factor of 30 in those arrays examined. Derivatization of the AAA arrays with electron donating substituents reveals a similar magnitude effect on the complex stabilities. The effect of substitution on both types of arrays are modeled quite satisfactorily (R(2) > 0.96 in all cases) as free energy relationships with respect to the sums of their Hammett substituent constants. In all, the complex stabilities can be manipulated over more than three orders of magnitude (>20 kJ mol(-1)) using this type of modification.

  17. Dosimetric comparison of Acuros XB, AAA, and XVMC in stereotactic body radiotherapy for lung cancer

    SciTech Connect

    Tsuruta, Yusuke; Nakata, Manabu; Higashimura, Kyoji; Nakamura, Mitsuhiro Matsuo, Yukinori; Monzen, Hajime; Mizowaki, Takashi; Hiraoka, Masahiro

    2014-08-15

    Purpose: To compare the dosimetric performance of Acuros XB (AXB), anisotropic analytical algorithm (AAA), and x-ray voxel Monte Carlo (XVMC) in heterogeneous phantoms and lung stereotactic body radiotherapy (SBRT) plans. Methods: Water- and lung-equivalent phantoms were combined to evaluate the percentage depth dose and dose profile. The radiation treatment machine Novalis (BrainLab AG, Feldkirchen, Germany) with an x-ray beam energy of 6 MV was used to calculate the doses in the composite phantom at a source-to-surface distance of 100 cm with a gantry angle of 0°. Subsequently, the clinical lung SBRT plans for the 26 consecutive patients were transferred from the iPlan (ver. 4.1; BrainLab AG) to the Eclipse treatment planning systems (ver. 11.0.3; Varian Medical Systems, Palo Alto, CA). The doses were then recalculated with AXB and AAA while maintaining the XVMC-calculated monitor units and beam arrangement. Then the dose-volumetric data obtained using the three different radiation dose calculation algorithms were compared. Results: The results from AXB and XVMC agreed with measurements within ±3.0% for the lung-equivalent phantom with a 6 × 6 cm{sup 2} field size, whereas AAA values were higher than measurements in the heterogeneous zone and near the boundary, with the greatest difference being 4.1%. AXB and XVMC agreed well with measurements in terms of the profile shape at the boundary of the heterogeneous zone. For the lung SBRT plans, AXB yielded lower values than XVMC in terms of the maximum doses of ITV and PTV; however, the differences were within ±3.0%. In addition to the dose-volumetric data, the dose distribution analysis showed that AXB yielded dose distribution calculations that were closer to those with XVMC than did AAA. Means ± standard deviation of the computation time was 221.6 ± 53.1 s (range, 124–358 s), 66.1 ± 16.0 s (range, 42–94 s), and 6.7 ± 1.1 s (range, 5–9 s) for XVMC, AXB, and AAA, respectively. Conclusions: In the

  18. The Drug Diazaborine Blocks Ribosome Biogenesis by Inhibiting the AAA-ATPase Drg1*

    PubMed Central

    Loibl, Mathias; Klein, Isabella; Prattes, Michael; Schmidt, Claudia; Kappel, Lisa; Zisser, Gertrude; Gungl, Anna; Krieger, Elmar; Pertschy, Brigitte; Bergler, Helmut

    2014-01-01

    The drug diazaborine is the only known inhibitor of ribosome biogenesis and specifically blocks large subunit formation in eukaryotic cells. However, the target of this drug and the mechanism of inhibition were unknown. Here we identify the AAA-ATPase Drg1 as a target of diazaborine. Inhibitor binding into the second AAA domain of Drg1 requires ATP loading and results in inhibition of ATP hydrolysis in this site. As a consequence the physiological activity of Drg1, i.e. the release of Rlp24 from pre-60S particles, is blocked, and further progression of cytoplasmic preribosome maturation is prevented. Our results identify the first target of an inhibitor of ribosome biogenesis and provide the mechanism of inhibition of a key step in large ribosomal subunit formation. PMID:24371142

  19. Predicting uterine rupture in women undergoing trial of labor after prior cesarean delivery.

    PubMed

    Landon, Mark B

    2010-08-01

    Uterine rupture is the most serious complication for women undergoing trial of labor (TOL) after prior cesarean delivery. While rates of uterine rupture vary significantly according to a variety of clinically associated risk factors, the absolute risk for this complication ranges between 0.5 and 4 percent. Previous vaginal delivery and prior successful vaginal birth after cesarean delivery confer the lowest risk of rupture on women attempting TOL. In contrast, multiple prior cesareans, short interpregnancy interval, single layer uterine closure, prior preterm cesarean, labor induction and augmentation have all been suggested in some studies as factors which may increase the rate of uterine rupture. While considering these risk factors is important in counseling women regarding childbirth following cesarean delivery, the infrequency of uterine rupture coupled with relatively weak associations for most risk factors has prevented the development of an accurate prediction tool for uterine rupture. Preliminary studies suggest that sonographic evaluation of the uterine scar may hold some promise for identifying women at risk.

  20. Centrally-Rupturing Squib-Closure Disks

    NASA Technical Reports Server (NTRS)

    Richter, R.

    1986-01-01

    Rupture-disk design makes squib action more predictable. In new design, center of rupture disk contains cruciform indentation in which thickness reduced to about 0.5 mil (0.013 mm). Reduces strength of center of rupture disk in same manner as that of pull tabs on beverage cans; therefore, disk will fail predictably in center.

  1. 46 CFR 64.61 - Rupture disc.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Rupture disc. 64.61 Section 64.61 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.61 Rupture disc. If a rupture...

  2. 46 CFR 64.61 - Rupture disc.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Rupture disc. 64.61 Section 64.61 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.61 Rupture disc. If a rupture...

  3. 46 CFR 64.61 - Rupture disc.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Rupture disc. 64.61 Section 64.61 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.61 Rupture disc. If a rupture...

  4. 46 CFR 64.61 - Rupture disc.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Rupture disc. 64.61 Section 64.61 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.61 Rupture disc. If a rupture...

  5. 46 CFR 64.61 - Rupture disc.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Rupture disc. 64.61 Section 64.61 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.61 Rupture disc. If a rupture...

  6. Endovascular vs. Open Repair for Ruptured Abdominal Aortic Aneurysm

    PubMed Central

    Patelis, Nikolaos; Moris, Demetrios; Karaolanis, Georgios; Georgopoulos, Sotiris

    2016-01-01

    Background Patients presenting with ruptured abdominal aortic aneurysms are most often treated with open repair despite the fact that endovascular aneurysm repair is a less invasive and widely accepted method with clear benefits for elective aortic aneurysm patients. A debate exists regarding the definitive benefit in endovascular repair for patients with a ruptured abdominal aortic aneurysm. The aim of this literature review was to determine if any trends exist in favor of either open or endovascular repair. Material/Methods A literature search was performed using PUBMED, OVID, and Google Scholar databases. The search yielded 64 publications. Results Out of 64 publications, 25 were retrospective studies, 12 were population-based, 21 were prospective, 5 were the results of RCTs, and 1 was a case-series. Sixty-one studies reported on early mortality and provided data comparing endovascular repair (rEVAR) and open repair (rOR) for ruptured abdominal aneurysm groups. Twenty-nine of these studies reported that rEVAR has a lower early mortality rate. Late mortality after rEVAR compared to that of rOR was reported in 21 studies for a period of 3 to 60 months. Results of 61.9% of the studies found no difference in late mortality rates between these 2 groups. Thirty-nine publications reported on the incidence of complications. Approximately half of these publications support that the rEVAR group has a lower complication rate and the other half found no difference between the groups. Length of hospital stay has been reported to be shorter for rEVAR in most studies. Blood loss and need for transfusion of either red cells or fresh frozen plasma was consistently lower in the rEVAR group. Conclusions Differences between the included publications affect the outcomes. Randomized control trials have not been able to provide clear conclusions. rEVAR can now be considered a safe method of treating rAAA, and is at least equal to the well-established rOR method. PMID:27090791

  7. Structures of the double-ring AAA ATPase Pex1-Pex6 involved in peroxisome biogenesis.

    PubMed

    Tan, Dongyan; Blok, Neil B; Rapoport, Tom A; Walz, Thomas

    2016-03-01

    The Pex1 and Pex6 proteins are members of the AAA family of ATPases and are involved in peroxisome biogenesis. Recently, cryo-electron microscopy structures of the Pex1-Pex6 complex in different nucleotide states have been determined. This Structural Snapshot describes the structural features of the complex and their implications for its function, as well as questions that still await answers.

  8. Characterization of ATPase activity of the AAA ARC from Bifidobacterium longum subsp. infantis.

    PubMed

    Guzmán-Rodríguez, Mabel; de la Rosa, Ana Paulina Barba; Santos, Leticia

    2015-01-01

    Bifidobacteria are considered to be probiotics that exist in the large intestine and are helpful to maintain human health. Oral administration of bifidobacteria may be effective in improving the intestinal flora and environment, stimulating the immune response and possibly preventing cancer. However, for consistent and positive results, further well-controlled studies are urgently needed to describe the basic mechanisms of this microorganism. Analysis of the proteasome-lacking Bifidobacterium longum genome reveals that it possesses a gene, IPR003593 AAA ATPase core, which codes a 56 kDa protein containing one AAA ATPase domain. Phylogenetic classification made by CLANS, positioned this sequence into the ARC divergent branch of the AAA ATPase family of proteins. N-terminal analysis of the sequence indicates this protein is closely related to other ATPases such as the Rhodococcus erythropolis ARC, Archaeoglobus fulgidus PAN, Mycobacterium tuberculosis Mpa and the human proteasomal Rpt1 subunit. This gene was cloned, the full-length recombinant protein was overexpressed in Escherichia coli, purified as a high-molecular size complex and named Bl-ARC. Enzymatic characterization showed that Bl-ARC ATPase is active, Mg(+2)-dependent and sensitive to N-ethylmaleimide. Gene organization positions bl-arc in a region flanked by a cluster of genes that includes pup, dop and pafA genes. These findings point to a possible function as a chaperone in the degradation pathway via pupylation.

  9. An atypical AAA+ ATPase assembly controls efficient transposition through DNA remodeling and transposase recruitment

    PubMed Central

    Arias-Palomo, Ernesto; Berger, James M.

    2015-01-01

    Transposons are ubiquitous genetic elements that drive genome rearrangements, evolution, and the spread of infectious disease and drug-resistance. Many transposons, such as Mu, Tn7 and IS21, require regulatory AAA+ ATPases for function. We use x-ray crystallography and cryo-electron microscopy to show that the ATPase subunit of IS21, IstB, assembles into a clamshell-shaped decamer that sandwiches DNA between two helical pentamers of ATP-associated AAA+ domains, sharply bending the duplex into a 180° U-turn. Biochemical studies corroborate key features of the structure, and further show that the IS21 transposase, IstA, recognizes the IstB•DNA complex and promotes its disassembly by stimulating ATP hydrolysis. Collectively, these studies reveal a distinct manner of higher-order assembly and client engagement by a AAA+ ATPase and suggest a mechanistic model where IstB binding and subsequent DNA bending primes a selected insertion site for efficient transposition. PMID:26276634

  10. Structural basis for DNA-mediated allosteric regulation facilitated by the AAA+ module of Lon protease.

    PubMed

    Lee, Alan Yueh-Luen; Chen, Yu-Da; Chang, Yu-Yung; Lin, Yu-Ching; Chang, Chi-Fon; Huang, Shing-Jong; Wu, Shih-Hsiung; Hsu, Chun-Hua

    2014-02-01

    Lon belongs to a unique group of AAA+ proteases that bind DNA. However, the DNA-mediated regulation of Lon remains elusive. Here, the crystal structure of the α subdomain of the Lon protease from Brevibacillus thermoruber (Bt-Lon) is presented, together with biochemical data, and the DNA-binding mode is delineated, showing that Arg518, Arg557 and Arg566 play a crucial role in DNA binding. Electrostatic interactions contributed by arginine residues in the AAA+ module are suggested to be important to DNA binding and allosteric regulation of enzymatic activities. Intriguingly, Arg557, which directly binds DNA in the α subdomain, has a dual role in the negative regulation of ATPase stimulation by DNA and in the domain-domain communication in allosteric regulation of Bt-Lon by substrate. In conclusion, structural and biochemical evidence is provided to show that electrostatic interaction in the AAA+ module is important for DNA binding by Lon and allosteric regulation of its enzymatic activities by DNA and substrate.

  11. Subunit dynamics and nucleotide-dependent asymmetry of an AAA(+) transcription complex.

    PubMed

    Zhang, Nan; Gordiyenko, Yuliya; Joly, Nicolas; Lawton, Edward; Robinson, Carol V; Buck, Martin

    2014-01-01

    Bacterial enhancer binding proteins (bEBPs) are transcription activators that belong to the AAA(+) protein family. They form higher-order self-assemblies to regulate transcription initiation at stress response and pathogenic promoters. The precise mechanism by which these ATPases utilize ATP binding and hydrolysis energy to remodel their substrates remains unclear. Here we employed mass spectrometry of intact complexes to investigate subunit dynamics and nucleotide occupancy of the AAA(+) domain of one well-studied bEBP in complex with its substrate, the σ(54) subunit of RNA polymerase. Our results demonstrate that the free AAA(+) domain undergoes significant changes in oligomeric states and nucleotide occupancy upon σ(54) binding. Such changes likely correlate with one transition state of ATP and are associated with an open spiral ring formation that is vital for asymmetric subunit function and interface communication. We confirmed that the asymmetric subunit functionality persists for open promoter complex formation using single-chain forms of bEBP lacking the full complement of intact ATP hydrolysis sites. Outcomes reconcile low- and high-resolution structures and yield a partial sequential ATP hydrolysis model for bEBPs. PMID:24055699

  12. Functional characterization of fidgetin, an AAA-family protein mutated in fidget mice

    SciTech Connect

    Yang Yan; Mahaffey, Connie L.; Berube, Nathalie; Nystuen, Arne; Frankel, Wayne N. . E-mail: wnf@jax.org

    2005-03-10

    The mouse fidget mutation is an autosomal recessive mutation that renders reduced or absent semicircular canals, microphthalmia, and various skeletal abnormalities to affected mice. We previously identified the defective gene which encodes fidgetin, a new member of the ATPases associated with diverse cellular activities (AAA proteins). Here, we report on the subcellular localization of fidgetin as well as that of two closely related proteins, fidgetin-like 1 and fidgetin-like 2. Epitope-tagging and immunostaining revealed that both fidgetin and fidgetin-like 2 were predominantly localized to the nucleus, whereas fidgetin-like 1 was both nuclear and cytoplasmic. Furthermore, deletion studies identified a putative bipartite nuclear localization signal in the middle portion of the fidgetin protein. Since AAA proteins are known to form functional hetero- or homo-hexamers, we used reciprocal immunoprecipitation to examine the potential interaction among these proteins. We found that fidgetin interacted with itself and this specific interaction was abolished when either the N- or C-terminus of the protein was truncated. Taken together, our results suggest that fidgetin is a nuclear AAA-family protein with the potential to form homo-oligomers, thus representing the first step towards the elucidation of fidgetin's cellular function and the disease mechanism in fidget mutant mice.

  13. Molecular snapshots of the Pex1/6 AAA+ complex in action

    PubMed Central

    Ciniawsky, Susanne; Grimm, Immanuel; Saffian, Delia; Girzalsky, Wolfgang; Erdmann, Ralf; Wendler, Petra

    2015-01-01

    The peroxisomal proteins Pex1 and Pex6 form a heterohexameric type II AAA+ ATPase complex, which fuels essential protein transport across peroxisomal membranes. Mutations in either ATPase in humans can lead to severe peroxisomal disorders and early death. We present an extensive structural and biochemical analysis of the yeast Pex1/6 complex. The heterohexamer forms a trimer of Pex1/6 dimers with a triangular geometry that is atypical for AAA+ complexes. While the C-terminal nucleotide-binding domains (D2) of Pex6 constitute the main ATPase activity of the complex, both D2 harbour essential substrate-binding motifs. ATP hydrolysis results in a pumping motion of the complex, suggesting that Pex1/6 function involves substrate translocation through its central channel. Mutation of the Walker B motif in one D2 domain leads to ATP hydrolysis in the neighbouring domain, giving structural insights into inter-domain communication of these unique heterohexameric AAA+ assemblies. PMID:26066397

  14. Functional characterization of fidgetin, an AAA-family protein mutated in fidget mice.

    PubMed

    Yang, Yan; Mahaffey, Connie L; Bérubé, Nathalie; Nystuen, Arne; Frankel, Wayne N

    2005-03-10

    The mouse fidget mutation is an autosomal recessive mutation that renders reduced or absent semicircular canals, microphthalmia, and various skeletal abnormalities to affected mice. We previously identified the defective gene which encodes fidgetin, a new member of the ATPases associated with diverse cellular activities (AAA proteins). Here, we report on the subcellular localization of fidgetin as well as that of two closely related proteins, fidgetin-like 1 and fidgetin-like 2. Epitope-tagging and immunostaining revealed that both fidgetin and fidgetin-like 2 were predominantly localized to the nucleus, whereas fidgetin-like 1 was both nuclear and cytoplasmic. Furthermore, deletion studies identified a putative bipartite nuclear localization signal in the middle portion of the fidgetin protein. Since AAA proteins are known to form functional hetero- or homo-hexamers, we used reciprocal immunoprecipitation to examine the potential interaction among these proteins. We found that fidgetin interacted with itself and this specific interaction was abolished when either the N- or C-terminus of the protein was truncated. Taken together, our results suggest that fidgetin is a nuclear AAA-family protein with the potential to form homo-oligomers, thus representing the first step towards the elucidation of fidgetin's cellular function and the disease mechanism in fidget mutant mice.

  15. [Spontaneous uterine rupture in third trimester twin ivf pregnancy following myomectomy].

    PubMed

    Tsankova, M; Nikolov, A; Bosev, D; Pirnareva, E

    2012-01-01

    Uterine rupture is one of the most serious complications of pregnancy, causing maternal and perinatal death. An increased risk of uterine rupture is associated with uterine scars caused by previous cesarean section, myomectomy, hysteroscopic procedures and ART treatment. We report a case of 35-year-old nulliparous woman with a twin pregnancy who experienced a spontaneous uterine rupture at 30 weeks' gestation. She had a previous history of one opened myomectomy, two laporoscopic procedures for extrauterine pregnancy and myomectomy in the left uterine corn. Her pregnancy was established with in vitro fertilization 14 months after the laparoscopic myomectomy. The uterine rupture was heralded by a sudden onset of severe abdominal pain while she was having a routine exam. This case reinforces that pregnancy after myomectomy should be closely monitored with respect to uterine rupture.

  16. Essentials of anterior cruciate ligament rupture management.

    PubMed

    Klinge, Stephen A; Sawyer, Gregory A; Hulstyn, Michael J

    2013-05-01

    Anterior cruciate ligament (ACL) rupture is a common knee injury and an understanding of current medical knowledge regarding its management is essential. Accurate and prompt diagnosis requires an awareness of injury mechanisms and risk factors, common symptoms and physical/radiologic findings. Early mobilization and physical therapy improves outcomes regardless of treatment modality. Many older patients regain sufficient stability and function after non-operative rehabilitation. Early ACL reconstruction is appropriate for younger patients and those who engage in activities requiring frequent pivoting and rapid direction changes. ACL surgery involves reconstruction of the torn ligament tissue with various replacement graft options, each with advantages and disadvantages. The guidance of a knowledgeable and experienced therapist is required throughout an intensive and prolonged rehabilitation course. Generally excellent outcomes and low complication rates are expected, but treatment does not prevent late osteoarthritis.

  17. [Quadriceps and patellar tendon ruptures].

    PubMed

    Grim, C; Lorbach, O; Engelhardt, M

    2010-12-01

    Ruptures of the quadriceps or patellar tendon are uncommon but extremely relevant injuries. Early diagnosis and surgical treatment with a stable suture construction are mandatory for a good postoperative clinical outcome. The standard methods of repair for quadriceps and patellar tendon injuries include the placement of suture loops through transpatellar tunnels. Reinforcement with either a wire cerclage or a PDS cord is used in patellar tendon repair. The PDS cord can also be applied as augmentation in quadriceps tendon repair. In secondary patellar tendon repair an autologous semitendinosus graft can be used. For chronic quadriceps tendon defects a V-shaped tendon flap with a distal footing is recommended. The different methods of repair should lead to early functional postoperative treatment. The clinical outcome after surgical treatment of patellar and quadriceps tendon ruptures is mainly good.

  18. [Two cases of testicular rupture].

    PubMed

    Tsujino, S; Hirata, T; Shimizu, H; Ito, T; Shiozawa, H; Koshiba, K

    1989-06-01

    Two cases of testicular rupture are presented and 119 cases in Japanese literature are reviewed. A 29-year-old man and a 32-year-old man were admitted to our hospital with the complaint of gradually increasing pains and swelling on the right testicle. Four days and three days before admission they experienced trauma during athletic activities. The diagnosis was established preoperatively by means of ultrasonography in the first one, but not in the other. The necrotic tissue of 1/3-1/2 of testis was removed and tunica albuginea was repaired in both cases. Of 119 cases of testicular rupture in Japanese literature a peak occurs in the 2nd decade and during contact sports. The ultrasonography is an effective diagnostic modality. The rate of orchiectomy has been decreasing. The function of the affected testis is hard to evaluate.

  19. Statistical wall shear stress maps of ruptured and unruptured middle cerebral artery aneurysms

    PubMed Central

    Goubergrits, L.; Schaller, J.; Kertzscher, U.; van den Bruck, N.; Poethkow, K.; Petz, Ch.; Hege, H.-Ch.; Spuler, A.

    2012-01-01

    Haemodynamics and morphology play an important role in the genesis, growth and rupture of cerebral aneurysms. The goal of this study was to generate and analyse statistical wall shear stress (WSS) distributions and shapes in middle cerebral artery (MCA) saccular aneurysms. Unsteady flow was simulated in seven ruptured and 15 unruptured MCA aneurysms. In order to compare these results, all geometries must be brought in a uniform coordinate system. For this, aneurysms with corresponding WSS data were transformed into a uniform spherical shape; then, all geometries were uniformly aligned in three-dimensional space. Subsequently, we compared statistical WSS maps and surfaces of ruptured and unruptured aneurysms. No significant (p > 0.05) differences exist between ruptured and unruptured aneurysms regarding radius and mean WSS. In unruptured aneurysms, statistical WSS map relates regions with high (greater than 3 Pa) WSS to the neck region. In ruptured aneurysms, additional areas with high WSS contiguous to regions of low (less than 1 Pa) WSS are found in the dome region. In ruptured aneurysms, we found significantly lower WSS. The averaged aneurysm surface of unruptured aneurysms is round shaped, whereas the averaged surface of ruptured cases is multi-lobular. Our results confirm the hypothesis of low WSS and irregular shape as the essential rupture risk parameters. PMID:21957117

  20. Rupture of vertical soap films

    NASA Astrophysics Data System (ADS)

    Rio, Emmanuelle

    2014-11-01

    Soap films are ephemeral and fragile objects. They tend to thin under gravity, which gives rise to the fascinating variations of colors at their interfaces but leads systematically to rupture. Even a child can create, manipulate and admire soap films and bubbles. Nevertheless, the reason why it suddenly bursts remains a mystery although the soap chosen to stabilize the film as well as the humidity of the air seem very important. One difficulty to study the rupture of vertical soap films is to control the initial solution. To avoid this problem we choose to study the rupture during the generation of the film at a controlled velocity. We have built an experiment, in which we measure the maximum length of the film together with its lifetime. The generation of the film is due to the presence of a gradient of surface concentration of surfactants at the liquid/air interface. This leads to a Marangoni force directed toward the top of the film. The film is expected to burst only when its weight is not balanced anymore by this force. We will show that this leads to the surprising result that the thicker films have shorter lifetimes than the thinner ones. It is thus the ability of the interface to sustain a surface concentration gradient of surfactants which controls its stability.

  1. Molecular dynamics of interface rupture

    NASA Technical Reports Server (NTRS)

    Koplik, Joel; Banavar, Jayanth R.

    1993-01-01

    Several situations have been studied in which a fluid-vapor or fluid-fluid interface ruptures, using molecular dynamics simulations of 3000 to 20,000 Lennard-Jones molecules in three dimensions. The cases studied are the Rayleigh instability of a liquid thread, the burst of a liquid drop immersed in a second liquid undergoing shear, and the rupture of a liquid sheet in an extensional flow. The late stages of the rupture process involve the gradual withdrawal of molecules from a thinning neck, or the appearance and growth of holes in a sheet. In all cases, it is found that despite the small size of the systems studied, tens of angstroms, the dynamics is in at least qualitative accord with the behavior expected from continuum calculations, and in some cases the agreement is to within tens of percent. Remarkably, this agreement occurs even though the Eulerian velocity and stress fields are essentially unmeasurable - dominated by thermal noise. The limitations and prospects for such molecular simulation techniques are assessed.

  2. Splenic rupture following routine colonoscopy.

    PubMed

    Rasul, Tabraze; Leung, Edmund; McArdle, Kirsten; Pathak, Rajiv; Dalmia, Sanjay

    2010-10-01

    Splenic rupture is a life-threatening condition characterized by internal hemorrhage, often difficult to diagnose. Colonoscopy is a gold standard routine diagnostic test to investigate patients with gastrointestinal symptoms as well as to those on the screening program for colorectal cancer. Splenic injury is seldomly discussed during consent for colonoscopy, as opposed to colonic perforation, as its prevalence accounts for less than 0.1%. A 66-year-old Caucasian woman with no history of collagen disorder was electively admitted for routine colonoscopy for surveillance of adenoma. She was admitted following the procedure for re-dosing of warfarin, which was stopped prior to the colonoscopy. The patient was found collapsed on the ward the following day with clinical shock and anemia. Computed tomography demonstrated grade 4 splenic rupture. Immediate blood transfusion and splenectomy was required. Splenic rupture following routine colonoscopy is extremely rare. Awareness of it on this occasion saved the patient's life. Despite it being a rare association, the seriousness warrants inclusion in all information leaflets concerning colonoscopy and during its consent.

  3. Structural Insights into the Unusually Strong ATPase Activity of the AAA Domain of the Caenorhabditis elegans Fidgetin-like 1 (FIGL-1) Protein*

    PubMed Central

    Peng, Wentao; Lin, Zhijie; Li, Weirong; Lu, Jing; Shen, Yuequan; Wang, Chunguang

    2013-01-01

    The FIGL-1 (fidgetin like-1) protein is a homolog of fidgetin, a protein whose mutation leads to multiple developmental defects. The FIGL-1 protein contains an AAA (ATPase associated with various activities) domain and belongs to the AAA superfamily. However, the biological functions and developmental implications of this protein remain unknown. Here, we show that the AAA domain of the Caenorhabditis elegans FIGL-1 protein (CeFIGL-1-AAA), in clear contrast to homologous AAA domains, has an unusually high ATPase activity and forms a hexamer in solution. By determining the crystal structure of CeFIGL-1-AAA, we found that the loop linking helices α9 and α10 folds into the short helix α9a, which has an acidic surface and interacts with a positively charged surface of the neighboring subunit. Disruption of this charge interaction by mutagenesis diminishes both the ATPase activity and oligomerization capacity of the protein. Interestingly, the acidic residues in helix α9a of CeFIGL-1-AAA are not conserved in other homologous AAA domains that have relatively low ATPase activities. These results demonstrate that the sequence of CeFIGL-1-AAA has adapted to establish an intersubunit charge interaction, which contributes to its strong oligomerization and ATPase activity. These unique properties of CeFIGL-1-AAA distinguish it from other homologous proteins, suggesting that CeFIGL-1 may have a distinct biological function. PMID:23979136

  4. Ground motion hazard from supershear rupture

    USGS Publications Warehouse

    Andrews, D.J.

    2010-01-01

    An idealized rupture, propagating smoothly near a terminal rupture velocity, radiates energy that is focused into a beam. For rupture velocity less than the S-wave speed, radiated energy is concentrated in a beam of intense fault-normal velocity near the projection of the rupture trace. Although confined to a narrow range of azimuths, this beam diverges and attenuates. For rupture velocity greater than the S-wave speed, radiated energy is concentrated in Mach waves forming a pair of beams propagating obliquely away from the fault. These beams do not attenuate until diffraction becomes effective at large distance. Events with supershear and sub-Rayleigh rupture velocity are compared in 2D plane-strain calculations with equal stress drop, fracture energy, and rupture length; only static friction is changed to determine the rupture velocity. Peak velocity in the sub-Rayleigh case near the termination of rupture is larger than peak velocity in the Mach wave in the supershear case. The occurrence of supershear rupture propagation reduces the most intense peak ground velocity near the fault, but it increases peak velocity within a beam at greater distances. ?? 2010.

  5. Flow Dynamics of Aneurysm Growth and Rupture: Challenges for the Development of Computational Flow Dynamics as a Diagnostic Tool to Detect Rupture-Prone Aneurysms.

    PubMed

    Frösen, Juhana

    2016-01-01

    Saccular intracranial aneurysm (sIA) is a relatively common disease that can potentially cause a devastating, life-threatening intracranial hemorrhage. Many sIAs never rupture and thus do not necessitate interventions, making the detection of rupture-prone sIAs a very relevant clinical problem. Moreover, because currently available methods to prevent sIA rupture have significant risks of morbidity and mortality, diagnostic tools that can predict imminent rupture and help plan proper timing of prophylactic interventions, can improve patient care. Hemorrhage from an sIA occurs when hemodynamic stress exceeds sIA wall strength. Computational fluid dynamics (CFD) is a tool with which the hemodynamic stress to which the sIA wall is exposed can be determined non-invasively. Studies using CFD in sIAs have demonstrated associations of wall shear stress (WSS) with aneurysm growth, fragile sIA wall, and sIA rupture; these studies show the potential of CFD as a diagnostic tool. This review discusses the limitations of CFD and of the studies performed, and what needs to be done in order to develop CFD into a useful diagnostic tool to determine aneurysm-specific rupture risk. PMID:27637634

  6. Alliance ruptures and rupture resolution in cognitive-behavior therapy: a preliminary task analysis.

    PubMed

    Aspland, Helen; Llewelyn, Susan; Hardy, Gillian E; Barkham, Michael; Stiles, William

    2008-11-01

    An initial ideal, rational model of alliance rupture and rupture resolution provided by cognitive-behavioral therapy (CBT) experts was assessed and compared with empirical observations of ruptures and their resolution in two cases of successful CBT. The initial rational model emphasized nondefensive acknowledgment and exploration of the rupture. Results indicated differences between what therapists think they should do to resolve ruptures and what they actually do and suggested that the rational model should be expanded to emphasize client validation and empowerment. Therapists' ability to attend to ruptures emerged as an important clinical skill.

  7. Mycotic Aneurysm of the Celiac Trunk: From Early CT Sign to Rupture

    SciTech Connect

    Serafino, Gianpiero Vroegindeweij, Dammis; Boks, Simone; Harst, Erwin van der

    2005-06-15

    We present a case of the rapid development and rupture of a mycotic celiac trunk aneurysm. Initiallyon multislice computed tomography (ms-CT) there was a normal celiac trunk with minimal haziness of the surrounding fat. Only 2 weeks later the patient went into hypovolemic shock due to a ruptured celiac aneurysm. Although aneurysms of the visceral arteries are rare, they are of major clinical importance as they carry a life-threatening risk of rupture. This case illustrates the use of ms-CT in detecting and evaluating visceral aneurysms, in order to prevent emergency operation.

  8. Coil Embolization Treatment in Pulmonary Artery Branch Rupture During Swan-Ganz Catheterization

    SciTech Connect

    Gottwalles, Yannick; Wunschel-Joseph, Marie-Eve; Hanssen, Michel

    2000-11-15

    Rupture of the pulmonary artery or one of its branches during Swan-Ganz catheterization is a complication that is rare but remains fatal in almost 50% of cases. The risk factors and mechanisms involved in the pathogenesis of this accident have been widely reported. Management is twofold: resuscitation procedures and specific medical or even surgical treatment. We report a case of pulmonary artery rupture occurring during Swan-Ganz catheterization that was treated by coil embolization. This technique, which is quick and simple to use, would appear to be very promising. This is the first case of successful emergency treatment of pulmonary artery rupture using an endovascular technique.

  9. Multiple linear regression models to fit magnitude using rupture length, rupture width, rupture area, and surface displacement

    NASA Astrophysics Data System (ADS)

    Chu, A.; Zhuang, J.

    2015-12-01

    Wells and Coppersmith (1994) have used fault data to fit simple linear regression (SLR) models to explain linear relations between moment magnitude and logarithms of fault measurements such as rupture length, rupture width, rupture area and surface displacement. Our work extends their analyses to multiple linear regression (MLR) models by considering two or more predictors with updated data. Treating the quantitative variables (rupture length, rupture width, rupture area and surface displacement) as predictors to fit linear regression models on magnitude, we have discovered that the two-predictor model using rupture area and maximum displacement fits the best. The next best alternative predictors are surface length and rupture area. Neither slip type nor slip direction is a significant predictor by fitting of analysis of variance (ANOVA) and analysis of covariance (ANCOVA) models. Corrected Akaike information criterion (Burnham and Anderson, 2002) is used as a model assessment criterion. Comparisons between simple linear regression models of Wells and Coppersmith (1994) and our multiple linear regression models are presented. Our work is done using fault data from Wells and Coppersmith (1994) and new data from Ellswort (2000), Hanks and Bakun (2002, 2008), Shaw (2013), and Finite-Source Rupture Model Database (http://equake-rc.info/SRCMOD/, 2015).

  10. Soft, Brown Rupture: Clinical Signs and Symptoms Associated with Ruptured PIP Breast Implants

    PubMed Central

    Duncan, Robert T.; Feig, Christine; Reintals, Michelle; Hill, Sarah

    2014-01-01

    Background: Preoperative signs and symptoms of patients with Poly Implant Prothese (PIP) implants could be predictive of device failure. Based on clinical observation and intraoperative findings 4 hypotheses were raised: (1) Preoperative clinical signs including acquired asymmetry, breast enlargement, fullness of the lower pole, decreased mound projection, and change in breast consistency could be indicative of implant rupture. (2) Device failure correlates with a low preoperative Baker grade of capsule. (3) Brown-stained implants are more prone to implant failure. (4) The brown gel could be indicative of iodine ingression through a substandard elastomer shell. Methods: Preoperative clinical signs were compared with intraoperative findings for 27 patients undergoing PIP implant explantation. Results: Acquired asymmetry (P = 0.0003), breast enlargement (P = 0.0002), fuller lower pole (P < 0.0001), and loss of lateral projection (P < 0.0001) were all significantly predictive of device failure. Capsule Baker grade was lower preoperatively for ruptured implants. The lack of palpable and visible preoperative capsular contracture could be secondary to the elastic nature of the capsular tissue found. Brown implants failed significantly more often than white implants. Analysis of brown gel revealed the presence of iodine, suggesting povidone iodine ingression at implantation. Conclusions: Preoperative signs can be predictive of PIP implant failure. Brown-stained implants are more prone to rupture. The presence of iodine in the gel suggests unacceptable permeability of the shell early in the implant’s life span. A noninvasive screening test to detect brown implants in situ could help identify implants at risk of failure in those who elect to keep their implants. PMID:25506532

  11. NASA Astrophysics E/PO Impact: NASA SOFIA AAA Program Evaluation Results

    NASA Astrophysics Data System (ADS)

    Harman, Pamela; Backman, Dana E.; Clark, Coral; Inverness Research Sofia Aaa Evaluation Team, Wested Sofia Aaa Evaluation Team

    2015-01-01

    SOFIA is an airborne observatory, studying the universe at infrared wavelengths, capable of making observations that are impossible for even the largest and highest ground-based telescopes. SOFIA also inspires the development of new scientific instrumentation and fosters the education of young scientists and engineers.SOFIA is an 80% - 20% partnership of NASA and the German Aerospace Center (DLR), consisting of an extensively modified Boeing 747SP aircraft carrying a reflecting telescope with an effective diameter of 2.5 meters (100 inches). The SOFIA aircraft is based at NASA Armstrong Flight Research Center, Building 703, in Palmdale, California. The Science Program and Outreach Offices are located at NASA Ames Research center. SOFIA is a program in NASA's Science Mission Directorate, Astrophysics Division.Data will be collected to study many different kinds of astronomical objects and phenomena, including star cycles, solar system formation, identification of complex molecules in space, our solar system, galactic dust, nebulae and ecosystems.Airborne Astronomy Ambassador (AAA) Program:The SOFIA Education and Communications program exploits the unique attributes of airborne astronomy to contribute to national goals for the reform of science, technology, engineering, and math (STEM) education, and to elevate public scientific and technical literacy.The AAA effort is a professional development program aspiring to improve teaching, inspire students, and inform the community. To date, 55 educators from 21 states; Cycles 0, 1 and 2; have completed their astronomy professional development and their SOFIA science flight experience. Evaluation has confirmed the program's positive impact on the teacher participants, on their students, and in their communities. The inspirational experience has positively impacted their practice and career trajectory. AAAs have incorporated content knowledge and specific components of their experience into their curricula, and have given

  12. Histologic analysis of ruptured quadriceps tendons.

    PubMed

    Trobisch, Per David; Bauman, Matthias; Weise, Kuno; Stuby, Fabian; Hak, David J

    2010-01-01

    Quadriceps tendon ruptures are uncommon injuries. Degenerative changes in the tendon are felt to be an important precondition for rupture. We retrospectively reviewed 45 quadriceps tendon ruptures in 42 patients. Quadriceps tendon ruptures occurred most often in the sixth and seventh decade of life. Men were affected six times as often as women. A tissue sample from the rupture-zone was obtained in 22 cases and histologic analysis was performed. Degenerative changes were present in only 14 (64%) of the 22 samples. We observed an increasing ratio of degenerative to nondegenerative tendons with increasing patient age. Our data suggests that quadriceps tendon rupture, especially in younger patients, can occur in the absence of pathologic tendon degeneration.

  13. Early second trimester uterine scar rupture.

    PubMed

    Bharatnur, Sunanda; Hebbar, Shripad; Shyamala, G

    2013-12-10

    Spontaneous uterine scar rupture can be lethal in pregnant women. A spontaneous uterine scar rupture in the early mid-trimester is rare and difficult to diagnose. This is a case of a 30-year-old woman (G2P1L1) at 19 weeks of gestation and having undergone a previous caesarean section presented with acute abdomen in shock. Laparotomy revealed a uterine scar rupture, which was resutured after evacuation of products of conception. This case merits that the uterine rupture should be considered as a differential diagnosis in pregnant women presenting with acute abdomen. In this case, although there was uterine rupture in the second trimester and a complete placental separation, fetus was alive which is quite unusual in patients presenting with rupture uterus.

  14. [Tendinosis and ruptures of the Achilles tendon].

    PubMed

    Amlang, M H; Zwipp, H

    2012-02-01

    Tendinosis of the Achilles tendon is a degenerative-reparative structural change of the tendon with microdefects, increases in cross-section due to cicatricial tendon regeneration, neoangiogenesis and reduction of elasticity. The previously used term tendinitis is only rarely used for the chronic form since signs of inflammation such as redness and hyperthermia or elevated levels of inflammatory parameters on laboratory testing are generally absent. Duplex sonography with visualization of the neovascularization has become a valuable supplement not only for diagnostics but also for therapy planning. The classic, conservative therapy for painful tendinosis consists of oral anti-inflammatory drugs, pain-adapted load reduction, raising the heel, stretching the calf musculature, and various physiotherapeutic interventions. When conservative treatment over a period of 4 - 6 months fails to produce any or non-adequate pain relief, an indication for surgical treatment should be considered. In the therapy for fresh ruptures of the Achilles tendon further developments in minimally invasive techniques have led to a worldwide paradigm change over the past 10 years. The decisive advantage of minimally invasive surgical techniques is the lower risk of wound infection as compared to the sutures of the open technique. When compared with conservative functional therapy the minimally invasive repair has the advantage of being less dependent on the compliance of the patient since, in the early phase of tendon healing the suture prevents a separation of the tendon ends upon controlled movements. However, not every patient with a ruptured Achilles tendon should be treated with a minimally invasive repair. Open tendon reconstruction and functional conservative therapy are still justified when the correct indication is given. PMID:22344862

  15. SU-E-P-16: A Feasibility Study of Using Eclipse AAA for SRS Treatement

    SciTech Connect

    Lim, S; LoSasso, T

    2015-06-15

    Purpose: To commission Varian Eclipse AAA for SRS treatment and compare the accuracy with Brainlab iPlan system for clinical cases measured with radiochromic film. Methods: A 6MV AAA clinical model for a Varian TrueBeam STx is used as baseline. The focal spot and field size of the baseline model(BASE) are (1.75,0.75) and 40×40cm{sup 2} respectively. Maximum field sizes, output factors(S{sub t}), FWHM focal spot and secondary source sizes are systematically adjusted to obtain an optimized model(OPT) by comparing the calculated PDD’s, profiles, and output factors with measurements taken with a stereotactic diode(SD) and, cc01 and cc04 ion chambers in Blue Phantom. In-phantom dose distributions of clinical SRS fields are calculated using the OPT and the clinical Brainlab iPlan pencil-beam. Within the 90% isodose-line(ROI), the average dose difference between the calculations and radiochromic film measurements are assessed. Results: The maximum field, focal spot and secondary source sizes for the OPT are 15×15cm{sup 2}, (0,0), and 32.3mm respectively. The OPT St input at 1.0 and 2.0cm fields are increased by 4.5% and 1.5% from BASE. The calculated output of the BASE and OPT underestimate by 16.1%–3.2% respectively at 0.5×0.5cm{sup 2} field and 3.1%−0.02% respectively at 1.0×1.0cm{sup 2} field. The depth doses at 10cm are within 3.5% and 0.4% of measurements for 0.5×0.5 and 1.0×1.0cm{sup 2}. The ROI dose of OPT and iPlan are within 1.6% and 0.6% of film measurements for 3.0cm clinical fields. For 1.0cm fields, the ROI dose of OPT underestimate 0.0–2.0% and iPlan overestimates 1.7–2.9% relative to measurements. Conclusion: The small field dose calculation of Eclipse AAA algorithm can be significantly improved by carefully adjusting the input parameters. The larger deviation of the OPT for 0.5×0.5cm{sup 2} field from measurements can be attributed to the lowest 1.0cm field size input limit of AAA. The OPT compares reasonably well with the iPlan pencil

  16. Investigation of cryogenic rupture disc design

    NASA Technical Reports Server (NTRS)

    Keough, J. B.; Oldland, A. H.

    1973-01-01

    Rupture disc designs of both the active (command actuated) and passive (pressure ruptured) types were evaluated for performance characteristics at cryogenic temperatures and for capability to operate in a variety of cryogens, including gaseous and liquid fluorine. The test results, coupled with information from literature and industry searches, were used to establish a statement of design criteria and recommended practices for application of rupture discs to cryogenic rocket propellant feed and vent systems.

  17. Acute Pectoralis Major Rupture Captured on Video.

    PubMed

    Ordas Bayon, Alejandro; Sandoval, Enrique; Valencia Mora, María

    2016-01-01

    Pectoralis major (PM) ruptures are uncommon injuries, although they are becoming more frequent. We report a case of a PM rupture in a young male who presented with axillar pain and absence of the anterior axillary fold after he perceived a snap while lifting 200 kg in the bench press. Diagnosis of PM rupture was suspected clinically and confirmed with imaging studies. The patient was treated surgically, reinserting the tendon to the humerus with suture anchors. One-year follow-up showed excellent results. The patient was recording his training on video, so we can observe in detail the most common mechanism of injury of PM rupture. PMID:27595030

  18. Rupture dynamics in model polymer systems.

    PubMed

    Borah, Rupam; Debnath, Pallavi

    2016-05-11

    In this paper we explore the rupture dynamics of a model polymer system to capture the microscopic mechanism during relative motion of surfaces at the single polymer level. Our model is similar to the model for friction introduced by Filippov, Klafter, and Urbakh [Filippov et al., Phys. Rev. Lett., 2004, 92, 135503]; but with an important generalization to a flexible transducer (modelled as a bead spring polymer) which is attached to a fixed rigid planar substrate by interconnecting bonds (modelled as harmonic springs), and pulled by a constant force FT. Bonds are allowed to rupture stochastically. The model is simulated, and the results for a certain set of parameters exhibit a sequential rupture mechanism resulting in rupture fronts. A mean field formalism is developed to study these rupture fronts and the possible propagating solutions for the coupled bead and bond dynamics, where the coupling excludes an exact analytical treatment. Numerical solutions to mean field equations are obtained by standard numerical techniques, and they agree well with the simulation results which show sequential rupture. Within a travelling wave formalism based on the Tanh method, we show that the velocity of the rupture front can be obtained in closed form. The derived expression for the rupture front velocity gives good agreement with the stochastic and mean field results, when the rupture is sequential, while propagating solutions for bead and bond dynamics are shown to agree under certain conditions. PMID:27087684

  19. Acute Pectoralis Major Rupture Captured on Video

    PubMed Central

    Valencia Mora, María

    2016-01-01

    Pectoralis major (PM) ruptures are uncommon injuries, although they are becoming more frequent. We report a case of a PM rupture in a young male who presented with axillar pain and absence of the anterior axillary fold after he perceived a snap while lifting 200 kg in the bench press. Diagnosis of PM rupture was suspected clinically and confirmed with imaging studies. The patient was treated surgically, reinserting the tendon to the humerus with suture anchors. One-year follow-up showed excellent results. The patient was recording his training on video, so we can observe in detail the most common mechanism of injury of PM rupture. PMID:27595030

  20. A higher plant mitochondrial homologue of the yeast m-AAA protease. Molecular cloning, localization, and putative function.

    PubMed

    Kolodziejczak, Marta; Kolaczkowska, Anna; Szczesny, Bartosz; Urantowka, Adam; Knorpp, Carina; Kieleczawa, Jan; Janska, Hanna

    2002-11-15

    Mitochondrial AAA metalloproteases play a fundamental role in mitochondrial biogenesis and function. They have been identified in yeast and animals but not yet in plants. This work describes the isolation and sequence analysis of the full-length cDNA from the pea (Pisum sativum) with significant homology to the yeast matrix AAA (m-AAA) protease. The product of this clone was imported into isolated pea mitochondria where it was processed to its mature form (PsFtsH). We have shown that the central region of PsFtsH containing the chaperone domain is exposed to the matrix space. Furthermore, we have demonstrated that the pea protease can complement respiration deficiency in the yta10 and/or yta12 null yeast mutants, indicating that the plant protein can compensate for the loss of at least some of the important m-AAA functions in yeast. Based on biochemical experiments using isolated pea mitochondria, we propose that PsFtsH-like m-AAA is involved in the accumulation of the subunit 9 of the ATP synthase in the mitochondrial membrane.

  1. Quadriceps and patellar tendon ruptures.

    PubMed

    Lee, Dennis; Stinner, Daniel; Mir, Hassan

    2013-10-01

    The diagnosis of quadriceps and patellar tendon ruptures requires a high index of suspicion and thorough history-taking to assess for medical comorbidities that may predispose patients to tendon degeneration. Radiographic assessment with plain films supplemented by ultrasound and magnetic resonance imaging when the work-up is equivocal further aids diagnosis; however, advanced imaging is often unnecessary in patients with functional extensor mechanism deficits. Acute repair is preferred, and transpatellar bone tunnels serve as the primary form of fixation when the tendon rupture occurs at the patellar insertion, with or without augmentation depending on surgeon preference. Chronic tears and disruptions following total knee arthroplasty are special cases requiring reconstructions with allograft, synthetic mesh, or autograft. Rehabilitation protocols generally allow immediate weight-bearing with the knee locked in extension and crutch support. Limited arc motion is started early with active flexion and passive extension and then advanced progressively, followed by full active range of motion and strengthening. Complications are few but include quadriceps atrophy, knee stiffness, and rerupture. Outcomes are excellent if repair is done acutely, with poorer outcomes associated with delayed repair.

  2. TRIP13 is a protein-remodeling AAA+ ATPase that catalyzes MAD2 conformation switching

    PubMed Central

    Ye, Qiaozhen; Rosenberg, Scott C; Moeller, Arne; Speir, Jeffrey A; Su, Tiffany Y; Corbett, Kevin D

    2015-01-01

    The AAA+ family ATPase TRIP13 is a key regulator of meiotic recombination and the spindle assembly checkpoint, acting on signaling proteins of the conserved HORMA domain family. Here we present the structure of the Caenorhabditis elegans TRIP13 ortholog PCH-2, revealing a new family of AAA+ ATPase protein remodelers. PCH-2 possesses a substrate-recognition domain related to those of the protein remodelers NSF and p97, while its overall hexameric architecture and likely structural mechanism bear close similarities to the bacterial protein unfoldase ClpX. We find that TRIP13, aided by the adapter protein p31(comet), converts the HORMA-family spindle checkpoint protein MAD2 from a signaling-active ‘closed’ conformer to an inactive ‘open’ conformer. We propose that TRIP13 and p31(comet) collaborate to inactivate the spindle assembly checkpoint through MAD2 conformational conversion and disassembly of mitotic checkpoint complexes. A parallel HORMA protein disassembly activity likely underlies TRIP13's critical regulatory functions in meiotic chromosome structure and recombination. DOI: http://dx.doi.org/10.7554/eLife.07367.001 PMID:25918846

  3. Going the distance: validation of Acuros and AAA at an extended SSD of 400 cm.

    PubMed

    Lamichhane, Narottam; Patel, Vivek N; Studenski, Matthew T

    2016-01-01

    Accurate dose calculation and treatment delivery is essential for total body irradiation (TBI). In an effort to verify the accuracy of TBI dose calculation at our institution, we evaluated both the Varian Eclipse AAA and Acuros algorithms to predict dose distributions at an extended source-to-surface distance (SSD) of 400 cm. Measurements were compared to calculated values for a 6 MV beam in physical and virtual phantoms at 400 cm SSD using open beams for both 5 × 5 and 40 × 40cm2 field sizes. Inline and crossline profiles were acquired at equivalent depths of 5 cm, 10 cm, and 20 cm. Depth-dose curves were acquired using EBT2 film and an ion chamber for both field sizes. Finally, a RANDO phantom was used to simulate an actual TBI treatment. At this extended SSD, care must be taken using the planning system as there is good relative agreement between measured and calculated profiles for both algorithms, but there are deviations in terms of the absolute dose. Acuros has better agreement than AAA in the penumbra region. PMID:27074473

  4. Changes in the wall shear stresses (WSS) during the enlargement of Abdominal Aortic Aneurysms (AAA)

    NASA Astrophysics Data System (ADS)

    Salsac, Anne-Virginie; Sparks, Steven R.; Chomaz, Jean-Marc; Lasheras, Juan C.

    2004-11-01

    The changes in the evolution of the spatial and temporal distribution of the WSS and gradients of WSS at different stages of the enlargement of AAAs are important to understand the etiology and progression of this vascular disease, since they affect the wall structural integrity, primarily via the changes induced on the shape, functions and metabolism of the endothelial cells. PIV measurements were performed in aneurysm models, while changing systematically their geometric parameters. We show that, even at very early stages of the disease (dilatation > 30%), the flow separates from the wall and the formation of a large vortex ring followed by internal shear layers leads to the generation of WSS that drastically differ from the healthy vessel. Inside the AAA, the mean WSS decreases to zero and the magnitude of the WSS can be as low as 26% of the value in a healthy vessel. Two regions with distinct patterns of WSS were identified. The region of flow detachment, with oscillatory WSS of very low mean, and the region of flow reattachment, located distally, where large, negative WSS and sustained gradients of WSS are produced as a result of the impact of the vortex ring on the wall.

  5. Structural Characterization of the ATPase Reaction Cycle of Endosomal AAA Protein Vps4

    SciTech Connect

    Xiao, Junyu; Xia, Hengchuan; Yoshino-Koh, Kae; Zhou, Jiahai; Xu, Zhaohui

    2008-12-12

    The multivesicular body (MVB) pathway functions in multiple cellular processes including cell surface receptor down-regulation and viral budding from host cells. An important step in the MVB pathway is the correct sorting of cargo molecules, which requires the assembly and disassembly of endosomal sorting complexes required for transport (ESCRTs) on the endosomal membrane. Disassembly of the ESCRTs is catalyzed by ATPase associated with various cellular activities (AAA) protein Vps4. Vps4 contains a single AAA domain and undergoes ATP-dependent quaternary structural change to disassemble the ESCRTs. Structural and biochemical analyses of the Vps4 ATPase reaction cycle are reported here. Crystal structures of Saccharomyces cerevisiae Vps4 in both the nucleotide-free form and the ADP-bound form provide the first structural view illustrating how nucleotide binding might induce conformational changes within Vps4 that lead to oligomerization and binding to its substrate ESCRT-III subunits. In contrast to previous models, characterization of the Vps4 structure now supports a model where the ground state of Vps4 in the ATPase reaction cycle is predominantly a monomer and the activated state is a dodecamer. Comparison with a previously reported human VPS4B structure suggests that Vps4 functions in the MVB pathway via a highly conserved mechanism supported by similar protein-protein interactions during its ATPase reaction cycle.

  6. Quantitative Characterization of the Hemodynamic Environment in Ruptured and Unruptured Brain Aneurysms

    PubMed Central

    Cebral, Juan R.; Mut, Fernando; Weir, Jane; Putman, Christopher

    2011-01-01

    Background and purpose Hemodynamics is thought to play an important role in the mechanisms of aneurysm pathogenesis, progression and rupture. The purpose of this study was to define quantitative measures related to qualitative flow characteristics previously analyzed and to investigate their relationship to aneurysm rupture. Methods The hemodynamic environments in 210 cerebral aneurysms were analyzed using image-based CFD under different flow conditions. Quantitative hemodynamic variables were defined and extracted from the simulation results. A statistical analysis of the relationship to the previous history of aneurysm rupture was performed, and the variability with flow conditions was assessed. Results Ruptured aneurysms were more likely to have larger inflow concentrations, larger maximum wall shear stress (WSS), larger shear concentrations and lower viscous dissipation ratios than unruptured aneurysms. Areas under low WSS and measures of abnormally low shear force distributions of ruptured and unruptured aneurysms were not statistically different. Although the values of hemodynamic quantities changed with different flow conditions, the statistical differences or ratios between their mean values over the ruptured and unruptured groups were maintained, for both pulsatile and steady flows. Conclusions Concentrated inflow streams and WSS distributions with elevated levels of maximal WSS and low aneurysmal viscous dissipation are statistically associated with a clinical history of prior aneurysm rupture. In contrast, the area and total viscous shear force applied in the aneurysm region subjected to abnormally low WSS levels are not. This study highlights the potential for image-based CFD for investigating aneurysm evolution mechanisms and for clinical assessment of aneurysm risks. PMID:21127144

  7. Systematic review of the incidence and consequences of uterine rupture in women with previous caesarean section

    PubMed Central

    Guise, Jeanne-Marie; McDonagh, Marian S; Osterweil, Patricia; Nygren, Peggy; Chan, Benjamin K S; Helfand, Mark

    2004-01-01

    Objective To evaluate the incidence and consequences of uterine rupture in women who have had a delivery by caesarean section. Design Systematic review. Data sources Medline, HealthSTAR, Cochrane Database of Systematic Reviews, Cochrane Controlled Trials Register, National Centre for Reviews and Dissemination, reference lists, and national experts. Studies in all languages were eligible if published in full. Review methods Methodological quality was evaluated for each study by using criteria from the United States Preventive Services Task Force and the National Health Service Centre for Reviews and Dissemination. Uterine rupture was categorised as asymptomatic or symptomatic. Results We reviewed 568 full text articles to identify 71 potentially eligible studies, 21 of which were rated at least fair in quality. Compared with elective repeat caesarean delivery, trial of labour increased the risk of uterine rupture by 2.7 (95% confidence interval 0.73 to 4.73) per 1000 cases. No maternal deaths were related to rupture. For women attempting vaginal delivery, the additional risk of perinatal death from rupture of a uterine scar was 1.4 (0 to 9.8) per 10 000 and the additional risk of hysterectomy was 3.4 (0 to 12.6) per 10 000. The rates of asymptomatic uterine rupture in trial of labour and elective repeat caesarean did not differ significantly. Conclusions Although the literature on uterine rupture is imprecise and inconsistent, existing studies indicate that 370 (213 to 1370) elective caesarean deliveries would need to be performed to prevent one symptomatic uterine rupture. PMID:15231616

  8. An atomic model AAA-ATPase/20S core particle sub-complex of the 26S proteasome

    PubMed Central

    Förster, Friedrich; Lasker, Keren; Beck, Florian; Nickell, Stephan; Sali, Andrej; Baumeister, Wolfgang

    2009-01-01

    The 26S proteasome is the most downstream element of the ubiquitin-proteasome pathway of protein degradation. It is composed of the 20S core particle (CP) and the 19S regulatory particle (RP). The RP consists of 6 AAA-ATPases and at least 13 non-ATPase subunits. Based on a cryo-EM map of the 26S proteasome, structures of homologs, and physical protein-protein interactions we derive an atomic model of the AAA-ATPase-CP sub-complex. The ATPase order in our model (Rpt1/Rpt2/Rpt6/Rpt3/Rpt4/Rpt5) is in excellent agreement with the recently identified base-precursor complexes formed during the assembly of the RP. Furthermore, the atomic CP-AAA-ATPase model suggests that the assembly chaperone Nas6 facilitates CP-RP association by enhancing the shape complementarity between Rpt3 and its binding CP alpha subunits partners. PMID:19653995

  9. An atomic model AAA-ATPase/20S core particle sub-complex of the 26S proteasome.

    PubMed

    Förster, Friedrich; Lasker, Keren; Beck, Florian; Nickell, Stephan; Sali, Andrej; Baumeister, Wolfgang

    2009-10-16

    The 26S proteasome is the most downstream element of the ubiquitin-proteasome pathway of protein degradation. It is composed of the 20S core particle (CP) and the 19S regulatory particle (RP). The RP consists of 6 AAA-ATPases and at least 13 non-ATPase subunits. Based on a cryo-EM map of the 26S proteasome, structures of homologs, and physical protein-protein interactions we derive an atomic model of the AAA-ATPase-CP sub-complex. The ATPase order in our model (Rpt1/Rpt2/Rpt6/Rpt3/Rpt4/Rpt5) is in excellent agreement with the recently identified base-precursor complexes formed during the assembly of the RP. Furthermore, the atomic CP-AAA-ATPase model suggests that the assembly chaperone Nas6 facilitates CP-RP association by enhancing the shape complementarity between Rpt3 and its binding CP alpha subunits partners.

  10. The ATPase of the phi29 DNA packaging motor is a member of the hexameric AAA+ superfamily.

    PubMed

    Schwartz, Chad; De Donatis, Gian Marco; Fang, Huaming; Guo, Peixuan

    2013-08-15

    The AAA+ superfamily of proteins is a class of motor ATPases performing a wide range of functions that typically exist as hexamers. The ATPase of phi29 DNA packaging motor has long been a subject of debate in terms of stoichiometry and mechanism of action. Here, we confirmed the stoichiometry of phi29 motor ATPase to be a hexamer and provide data suggesting that the phi29 motor ATPase is a member of the classical hexameric AAA+ superfamily. Native PAGE, EMSA, capillary electrophoresis, ATP titration, and binomial distribution assay show that the ATPase is a hexamer. Mutations in the known Walker motifs of the ATPase validated our previous assumptions that the protein exists as another member of this AAA+ superfamily. Our data also supports the finding that the phi29 DNA packaging motor uses a revolution mechanism without rotation or coiling (Schwartz et al., this issue).

  11. Effects of the Transient Blood Flow-Wall Interaction on the Wall Stress Distribution in Abdominal Aortic Aneurysm (AAA)

    NASA Astrophysics Data System (ADS)

    Tang, Rubing; Geindreau, Christian; Lasheras, Juan

    2006-11-01

    Our static finite element analysis (FEA) of both idealized and real clinical models has shown that the maximum diameter and asymmetry have substantial influence on the AAA wall stress distribution. The thrombus inside the AAA was also found to reduce the magnitude of the wall stresses. To achieve a better understanding of the wall stress distribution in real AAAs, a dynamic FEA was also performed. We considered models, both symmetric and non-symmetric, in which the aorta is assumed isotropic with nonlinear material properties. For the limiting case of rigid walls, the evolution of the flow pattern and the wall shear stresses due to fluid flow at different stages of cardiac cycle predicted by our simulations are compared with experimental results obtained in in-vitro models. A good agreement is found between both results. Finally, we have extended the analysis to the physiologically correct case of deformable walls and characterized the transient effects on the wall stresses.

  12. Moyamoya disease-associated protein mysterin/RNF213 is a novel AAA+ ATPase, which dynamically changes its oligomeric state

    NASA Astrophysics Data System (ADS)

    Morito, Daisuke; Nishikawa, Kouki; Hoseki, Jun; Kitamura, Akira; Kotani, Yuri; Kiso, Kazumi; Kinjo, Masataka; Fujiyoshi, Yoshinori; Nagata, Kazuhiro

    2014-03-01

    Moyamoya disease is an idiopathic human cerebrovascular disorder that is characterized by progressive stenosis and abnormal collateral vessels. We recently identified mysterin/RNF213 as its first susceptibility gene, which encodes a 591-kDa protein containing enzymatically active P-loop ATPase and ubiquitin ligase domains and is involved in proper vascular development in zebrafish. Here we demonstrate that mysterin further contains two tandem AAA+ ATPase modules and forms huge ring-shaped oligomeric complex. AAA+ ATPases are known to generally mediate various biophysical and mechanical processes with the characteristic ring-shaped structure. Fluorescence correlation spectroscopy and biochemical evaluation suggested that mysterin dynamically changes its oligomeric forms through ATP/ADP binding and hydrolysis cycles. Thus, the moyamoya disease-associated gene product is a unique protein that functions as ubiquitin ligase and AAA+ ATPase, which possibly contributes to vascular development through mechanical processes in the cell.

  13. An atomic model AAA-ATPase/20S core particle sub-complex of the 26S proteasome

    SciTech Connect

    Foerster, Friedrich; Lasker, Keren; Beck, Florian; Nickell, Stephan; Sali, Andrej; Baumeister, Wolfgang

    2009-10-16

    The 26S proteasome is the most downstream element of the ubiquitin-proteasome pathway of protein degradation. It is composed of the 20S core particle (CP) and the 19S regulatory particle (RP). The RP consists of 6 AAA-ATPases and at least 13 non-ATPase subunits. Based on a cryo-EM map of the 26S proteasome, structures of homologs, and physical protein-protein interactions we derive an atomic model of the AAA-ATPase-CP sub-complex. The ATPase order in our model (Rpt1/Rpt2/Rpt6/Rpt3/Rpt4/Rpt5) is in excellent agreement with the recently identified base-precursor complexes formed during the assembly of the RP. Furthermore, the atomic CP-AAA-ATPase model suggests that the assembly chaperone Nas6 facilitates CP-RP association by enhancing the shape complementarity between Rpt3 and its binding CP alpha subunits partners.

  14. Anterior cruciate ligament rupture: differences between males and females.

    PubMed

    Sutton, Karen M; Bullock, James Montgomery

    2013-01-01

    The rate of anterior cruciate ligament (ACL) rupture is three times higher in female athletes than in male athletes. Intrinsic factors such as increased quadriceps angle and increased posterior tibial slope may predispose girls and women to ACL injury. Compared with males, females have smaller notch widths and smaller ACL cross-sectional area; however, no conclusive correlation between ACL size and notch dimension exists, especially in relation to risk of ACL injury. Female athletes who land with the knees in inadequate flexion and in greater-than-normal valgus and external rotation are at increased risk of ACL injury. No conclusive link has been made between ACL injury and the menstrual cycle. Neuromuscular intervention protocols have been shown to reduce the rate of injury in girls and women. Females are more likely than males to have a narrow A-shaped intercondylar notch, and special surgical considerations are required in such cases. Following ACL reconstruction, female athletes are more likely than male athletes to rupture the contralateral ACL; however, males and females are equally likely to rupture the reconstructed knee. Although self-reported outcomes in the first 2 years following reconstruction are worse for females than for males, longer-term studies demonstrate no difference between males and females.

  15. SecAAA trimer is fully functional as SecAA dimer in the membrane: Existence of higher oligomers?

    PubMed Central

    Wang, Hongyun; Ma, Yamin; Hsieh, Ying-Hsin; Yang, Hsiuchin; Li, Minyong; Wang, Binghe; Tai, Phang C.

    2014-01-01

    SecA is an essential ATPase in bacterial Sec-dependent protein translocation pathway, and equilibrates between monomers and dimers in solution. The question of whether SecA functions as monomers or dimers in membranes during the protein translocation is controversial. We previously constructed a tail-to-head SecAA tandem dimer, and showed it is fully functional by complementation in vivo and protein translocation in vitro, indicating that SecA can function at least as a dimer in the membrane without dissociating into monomers. In this study, we further constructed genetically a tail-to-head SecAAA trimer, which is functional in complementing a temperature-sensitive secA mutant. The purified SecAAA trimer per protomer is fully active as SecAA tandem dimers in ATPase activity, in protein translocation in vitro and in ion channel activities in the oocytes. With these functional tail-to-head trimer SecAAA and tandem SecAA, we examined their surface topology in the presence of liposomes using AFM. As expected, the soluble SecAAA without lipids are larger than SecAA. However, the ring/pore structures of SecAAA trimers were, surprisingly, almost identical to the SecA 2-monomers and SecAA dimers, raising the intriguing possibility that the SecA may exist and function as hexamer ring-structures in membranes. Cross-linking with formaldehyde showed that SecA, SecAA and SecAAA could form larger oligomers, including the hexamers. The molecular modeling simulation shows that both tail-to-head and tail-to-tail hexamers in the membranes are possible. PMID:24704204

  16. Walker-A threonine couples nucleotide occupancy with the chaperone activity of the AAA+ ATPase ClpB

    PubMed Central

    Nagy, Maria; Wu, Hui-Chuan; Liu, Zhonghua; Kedzierska-Mieszkowska, Sabina; Zolkiewski, Michal

    2009-01-01

    Hexameric AAA+ ATPases induce conformational changes in a variety of macromolecules. AAA+ structures contain the nucleotide-binding P-loop with the Walker A sequence motif: GxxGxGK(T/S). A subfamily of AAA+ sequences contains Asn in the Walker A motif instead of Thr or Ser. This noncanonical subfamily includes torsinA, an ER protein linked to human dystonia and DnaC, a bacterial helicase loader. Role of the noncanonical Walker A motif in the functionality of AAA+ ATPases has not been explored yet. To determine functional effects of introduction of Asn into the Walker A sequence, we replaced the Walker-A Thr with Asn in ClpB, a bacterial AAA+ chaperone which reactivates aggregated proteins. We found that the T-to-N mutation in Walker A partially inhibited the ATPase activity of ClpB, but did not affect the ClpB capability to associate into hexamers. Interestingly, the noncanonical Walker A sequence in ClpB induced preferential binding of ADP vs. ATP and uncoupled the linkage between the ATP-bound conformation and the high-affinity binding to protein aggregates. As a consequence, ClpB with the noncanonical Walker A sequence showed a low chaperone activity in vitro and in vivo. Our results demonstrate a novel role of the Walker-A Thr in sensing the nucleotide's γ-phosphate and in maintaining an allosteric linkage between the P-loop and the aggregate binding site of ClpB. We postulate that AAA+ ATPases with the noncanonical Walker A might utilize distinct mechanisms to couple the ATPase cycle with their substrate-remodeling activity. PMID:19177562

  17. [Perioperative management of a ruptured sinus of Valsalva aneurysm].

    PubMed

    Peña, J J; Marqués, J I; Mateo, E; Llagunes, J; Aguar, F; de Andrés, J

    2008-03-01

    Congenital sinus of Valsalva aneurysms are extremely rare in Spain. The lesion consists of a defect that allows the aortic media to separate from the annulus fibrosus of the aortic valve, causing it to dilate with arterial pressure. The natural course of the aneurysm involves the risk of complication due to bacterial endocarditis, with conduction blocks or myocardial ischemia. Rupture of the aneurysm, usually into a right chamber, causes a left-right shunt that leads to heart failure and death if untreated. We present the case of a previously asymptomatic 60-year-old woman who presented with a clinical picture that led to a diagnosis of hyperthyroidism, and in whom there occurred a coincident rupture of a congenital sinus of Valsalva aneurysm. We describe the anesthetic procedure and emphasize the importance of intraoperative echocardiography throughout the resection of the aneurysm.

  18. Simultaneous and spontaneous bilateral quadriceps tendons rupture.

    PubMed

    Celik, Evrim Coşkun; Ozbaydar, Mehmet; Ofluoglu, Demet; Demircay, Emre

    2012-07-01

    Simultaneous and spontaneous bilateral quadriceps tendon rupture is an uncommon injury that is usually seen in association with multiple medical conditions and some medications. We report a case of simultaneous and spontaneous bilateral quadriceps tendon rupture that may be related to the long-term use of a statin.

  19. Fractal avalanche ruptures in biological membranes

    NASA Astrophysics Data System (ADS)

    Gözen, Irep; Dommersnes, Paul; Czolkos, Ilja; Jesorka, Aldo; Lobovkina, Tatsiana; Orwar, Owe

    2010-11-01

    Bilayer membranes envelope cells as well as organelles, and constitute the most ubiquitous biological material found in all branches of the phylogenetic tree. Cell membrane rupture is an important biological process, and substantial rupture rates are found in skeletal and cardiac muscle cells under a mechanical load. Rupture can also be induced by processes such as cell death, and active cell membrane repair mechanisms are essential to preserve cell integrity. Pore formation in cell membranes is also at the heart of many biomedical applications such as in drug, gene and short interfering RNA delivery. Membrane rupture dynamics has been studied in bilayer vesicles under tensile stress, which consistently produce circular pores. We observed very different rupture mechanics in bilayer membranes spreading on solid supports: in one instance fingering instabilities were seen resulting in floral-like pores and in another, the rupture proceeded in a series of rapid avalanches causing fractal membrane fragmentation. The intermittent character of rupture evolution and the broad distribution in avalanche sizes is consistent with crackling-noise dynamics. Such noisy dynamics appear in fracture of solid disordered materials, in dislocation avalanches in plastic deformations and domain wall magnetization avalanches. We also observed similar fractal rupture mechanics in spreading cell membranes.

  20. Fractal avalanche ruptures in biological membranes.

    PubMed

    Gözen, Irep; Dommersnes, Paul; Czolkos, Ilja; Jesorka, Aldo; Lobovkina, Tatsiana; Orwar, Owe

    2010-11-01

    Bilayer membranes envelope cells as well as organelles, and constitute the most ubiquitous biological material found in all branches of the phylogenetic tree. Cell membrane rupture is an important biological process, and substantial rupture rates are found in skeletal and cardiac muscle cells under a mechanical load. Rupture can also be induced by processes such as cell death, and active cell membrane repair mechanisms are essential to preserve cell integrity. Pore formation in cell membranes is also at the heart of many biomedical applications such as in drug, gene and short interfering RNA delivery. Membrane rupture dynamics has been studied in bilayer vesicles under tensile stress, which consistently produce circular pores. We observed very different rupture mechanics in bilayer membranes spreading on solid supports: in one instance fingering instabilities were seen resulting in floral-like pores and in another, the rupture proceeded in a series of rapid avalanches causing fractal membrane fragmentation. The intermittent character of rupture evolution and the broad distribution in avalanche sizes is consistent with crackling-noise dynamics. Such noisy dynamics appear in fracture of solid disordered materials, in dislocation avalanches in plastic deformations and domain wall magnetization avalanches. We also observed similar fractal rupture mechanics in spreading cell membranes.

  1. Flexor digitorum superficialis rupture: a case report.

    PubMed

    Culver, J E

    1976-04-01

    A rupture of the musculotendinous junction of the flexor digitorum superficialis to the index finger in a baseball pitcher is described. No underlying abnormality could be detected. Because of loss of strength and dexterity, repair of the rupture was accomplished with an improved result.

  2. The AAA-ATPase molecular chaperone Cdc48/p97 disassembles sumoylated centromeres, decondenses heterochromatin, and activates ribosomal RNA genes

    PubMed Central

    Mérai, Zsuzsanna; Chumak, Nina; García-Aguilar, Marcelina; Hsieh, Tzung-Fu; Nishimura, Toshiro; Schoft, Vera K.; Bindics, János; Ślusarz, Lucyna; Arnoux, Stéphanie; Opravil, Susanne; Mechtler, Karl; Zilberman, Daniel; Fischer, Robert L.; Tamaru, Hisashi

    2014-01-01

    Centromeres mediate chromosome segregation and are defined by the centromere-specific histone H3 variant (CenH3)/centromere protein A (CENP-A). Removal of CenH3 from centromeres is a general property of terminally differentiated cells, and the persistence of CenH3 increases the risk of diseases such as cancer. However, active mechanisms of centromere disassembly are unknown. Nondividing Arabidopsis pollen vegetative cells, which transport engulfed sperm by extended tip growth, undergo loss of CenH3; centromeric heterochromatin decondensation; and bulk activation of silent rRNA genes, accompanied by their translocation into the nucleolus. Here, we show that these processes are blocked by mutations in the evolutionarily conserved AAA-ATPase molecular chaperone, CDC48A, homologous to yeast Cdc48 and human p97 proteins, both of which are implicated in ubiquitin/small ubiquitin-like modifier (SUMO)-targeted protein degradation. We demonstrate that CDC48A physically associates with its heterodimeric cofactor UFD1-NPL4, known to bind ubiquitin and SUMO, as well as with SUMO1-modified CenH3 and mutations in NPL4 phenocopy cdc48a mutations. In WT vegetative cell nuclei, genetically unlinked ribosomal DNA (rDNA) loci are uniquely clustered together within the nucleolus and all major rRNA gene variants, including those rDNA variants silenced in leaves, are transcribed. In cdc48a mutant vegetative cell nuclei, however, these rDNA loci frequently colocalized with condensed centromeric heterochromatin at the external periphery of the nucleolus. Our results indicate that the CDC48ANPL4 complex actively removes sumoylated CenH3 from centromeres and disrupts centromeric heterochromatin to release bulk rRNA genes into the nucleolus for ribosome production, which fuels single nucleus-driven pollen tube growth and is essential for plant reproduction. PMID:25344531

  3. The effects of barriers on supershear rupture

    NASA Astrophysics Data System (ADS)

    Xu, Jiankuan; Zhang, Zhenguo; Chen, Xiaofei

    2016-07-01

    A barrier may induce a supershear rupture transition in some cases, whereas it may prevent the further propagation of a supershear rupture in other cases. We investigate the effects of a barrier on the supershear rupture propagation on a planar fault in a 3-D half-space. Our results show that the effect of a barrier on supershear is strongly dependent on its size, strength, and location. For larger sizes, shallower buried depths, and relatively higher strengths, the barrier tends to prevent supershear propagation more strongly. When the barrier is located on the free surface and near the critical distance, it prevents the further propagation of supershear rupture. If a barrier is located far from the critical distance, the first supershear daughter crack is slowed down and a new supershear daughter crack is generated after the rupture front passes through the barrier. This mechanism greatly lengthens the supershear transition distance.

  4. Spontaneous uterine rupture in the 35th week of gestation after laparoscopic adenomyomectomy.

    PubMed

    Nagao, Yukari; Osato, Kazuhiro; Kubo, Michiko; Kawamura, Takuya; Ikeda, Tomoaki; Yamawaki, Takaharu

    2016-01-01

    Uterine rupture rarely occurs during pregnancy, but it is a critical situation if so. It is already known that a history of uterine surgeries, such as cesarean section or myomectomy, is a risk factor for uterine rupture. Currently, the laparoscopic adenomyomectomy is a widely performed procedure, but associated risks have not been defined. We observed a case of spontaneous uterine rupture in a patient during the 35th week of gestation, after a laparoscopic adenomyomectomy. A 42-year-old, gravida 2, para 0 woman became pregnant after a laparoscopic adenomyomectomy and her pregnancy was conventional. At a scheduled date in the 35th week of gestation, after combined spinal epidural anesthesia and frequent uterine contractions, a weak pain suddenly ensued. After 13 minutes of uterine contractions, vaginal bleeding was evident. A cesarean section was performed, and the uterine rupture was found in the scar. After a laparoscopic adenomyomectomy, a pregnant uterus can easily rupture by rather weak and short uterine contractions, and is characterized by vaginal bleeding. When uterine bleeding is observed in pregnant women that have a history of adenomyomectomy, one should consider uterine rupture.

  5. Uterine rupture in pregnancy: two case reports and review of literature.

    PubMed

    Pontis, A; Prasciolu, C; Litta, P; Angioni, S

    2016-01-01

    Rupture of a gravid uterus is an obstetric emergency. Risks factors include a scarred uterus but also spontaneous rupture of an un- scarred uterus during pregnancy is possible. The authors present two cases of a spontaneous complete uterine rupture during pregnancy. The first case had only a past history of dilatation and curettage for abortion; the second case had a past history of dilatation and curettage for abortion and a monolateral laparoscopic salpingectomy for ectopic pregnancy. They presented with abdominal pain and after ultrasound scan, uterine ruptures were diagnosed. These cases show that there should be a high index of suspicious of uterine rupture in a gravid woman with a history of curettage for the possible presence of misunderstood uterine scar and in women with a past history of salpingectomy with or without corneal resection. Appropriate counseling and close follow-up might help to avoid such obstetrical catastrophes. To provide more insight into the possible risk factors for prelabor uterine rupture in pregnancy, a literature review was performed.

  6. Do buried-rupture earthquakes trigger less landslides than surface-rupture earthquakes for reverse faults?

    NASA Astrophysics Data System (ADS)

    Xu, Chong

    2014-07-01

    Gorum et al. (2013, Geomorphology 184, 127-138) carried out a study on inventory compilation and statistical analyses of landslides triggered by the 2010 Mw 7.0 Haiti earthquake. They revealed that spatial distribution patterns of these landslides were mainly controlled by complex rupture mechanism and topography. They also suggested that blind-rupture earthquakes trigger fewer landslides than surface-rupture earthquakes on thrust reverse faults. Although a few lines of evidence indicate that buried-rupture earthquakes might trigger fewer landslides than surface-rupture earthquakes on reverse faults, more careful comparisons and analyses indicate that it is not always true. Instead, some cases show that a buried-rupture earthquake can trigger a larger quantity of landslides that are distributed in a larger area, whereas surface-rupture earthquakes can trigger larger but a fewer landslides distributed in a smaller area.

  7. TU-C-BRE-05: Clinical Implications of AAA Commissioning Errors and Ability of Common Commissioning ' Credentialing Procedures to Detect Them

    SciTech Connect

    McVicker, A; Oldham, M; Yin, F; Adamson, J

    2014-06-15

    Purpose: To test the ability of the TG-119 commissioning process and RPC credentialing to detect errors in the commissioning process for a commercial Treatment Planning System (TPS). Methods: We introduced commissioning errors into the commissioning process for the Anisotropic Analytical Algorithm (AAA) within the Eclipse TPS. We included errors in Dosimetric Leaf Gap (DLG), electron contamination, flattening filter material, and beam profile measurement with an inappropriately large farmer chamber (simulated using sliding window smoothing of profiles). We then evaluated the clinical impact of these errors on clinical intensity modulated radiation therapy (IMRT) plans (head and neck, low and intermediate risk prostate, mesothelioma, and scalp) by looking at PTV D99, and mean and max OAR dose. Finally, for errors with substantial clinical impact we determined sensitivity of the RPC IMRT film analysis at the midpoint between PTV and OAR using a 4mm distance to agreement metric, and of a 7% TLD dose comparison. We also determined sensitivity of the 3 dose planes of the TG-119 C-shape IMRT phantom using gamma criteria of 3% 3mm. Results: The largest clinical impact came from large changes in the DLG with a change of 1mm resulting in up to a 5% change in the primary PTV D99. This resulted in a discrepancy in the RPC TLDs in the PTVs and OARs of 7.1% and 13.6% respectively, which would have resulted in detection. While use of incorrect flattening filter caused only subtle errors (<1%) in clinical plans, the effect was most pronounced for the RPC TLDs in the OARs (>6%). Conclusion: The AAA commissioning process within the Eclipse TPS is surprisingly robust to user error. When errors do occur, the RPC and TG-119 commissioning credentialing criteria are effective at detecting them; however OAR TLDs are the most sensitive despite the RPC currently excluding them from analysis.

  8. Spontaneous rupture of the spleen operated in gynecological unit mistaken for ruptured hemorrhagic ovarian cyst: total splenectomy

    PubMed Central

    Eko, Filbert Eko; Fouelifack, Florent Ymele; de Paul, Elanga Vincent

    2014-01-01

    Spontaneous splenic rupture is always neglected when consulting acute abdominal pains in gynecological emergencies. It constitutes about 1% of all splenic ruptures and can be managed by abstention, surgery or embolization. We present the case of a young lady who was diagnosed of spontaneous rupture during surgery that was mistaken for ruptured hemorrhagic ovarian cyst and finally treated by total splenectomy. The pre-operative work up was absolute for a rupturred hemorrhagic cyst and secondariy for a ruptured ectopic gestation. PMID:25918564

  9. Lytic Water Dynamics Reveal Evolutionarily Conserved Mechanisms of ATP Hydrolysis by TIP49 AAA+ ATPases

    PubMed Central

    Afanasyeva, Arina; Hirtreiter, Angela; Schreiber, Anne; Grohmann, Dina; Pobegalov, Georgii; McKay, Adam R.; Tsaneva, Irina; Petukhov, Michael; Käs, Emmanuel; Grigoriev, Mikhail; Werner, Finn

    2014-01-01

    Summary Eukaryotic TIP49a (Pontin) and TIP49b (Reptin) AAA+ ATPases play essential roles in key cellular processes. How their weak ATPase activity contributes to their important functions remains largely unknown and difficult to analyze because of the divergent properties of TIP49a and TIP49b proteins and of their homo- and hetero-oligomeric assemblies. To circumvent these complexities, we have analyzed the single ancient TIP49 ortholog found in the archaeon Methanopyrus kandleri (mkTIP49). All-atom homology modeling and molecular dynamics simulations validated by biochemical assays reveal highly conserved organizational principles and identify key residues for ATP hydrolysis. An unanticipated crosstalk between Walker B and Sensor I motifs impacts the dynamics of water molecules and highlights a critical role of trans-acting aspartates in the lytic water activation step that is essential for the associative mechanism of ATP hydrolysis. PMID:24613487

  10. Distinct quaternary structures of the AAA+ Lon protease control substrate degradation.

    PubMed

    Vieux, Ellen F; Wohlever, Matthew L; Chen, James Z; Sauer, Robert T; Baker, Tania A

    2013-05-28

    Lon is an ATPase associated with cellular activities (AAA+) protease that controls cell division in response to stress and also degrades misfolded and damaged proteins. Subunits of Lon are known to assemble into ring-shaped homohexamers that enclose an internal degradation chamber. Here, we demonstrate that hexamers of Escherichia coli Lon also interact to form a dodecamer at physiological protein concentrations. Electron microscopy of this dodecamer reveals a prolate structure with the protease chambers at the distal ends and a matrix of N domains forming an equatorial hexamer-hexamer interface, with portals of ∼45 Å providing access to the enzyme lumen. Compared with hexamers, Lon dodecamers are much less active in degrading large substrates but equally active in degrading small substrates. Our results support a unique gating mechanism that allows the repertoire of Lon substrates to be tuned by its assembly state.

  11. Metrics for comparing dynamic earthquake rupture simulations

    USGS Publications Warehouse

    Barall, Michael; Harris, Ruth A.

    2014-01-01

    Earthquakes are complex events that involve a myriad of interactions among multiple geologic features and processes. One of the tools that is available to assist with their study is computer simulation, particularly dynamic rupture simulation. A dynamic rupture simulation is a numerical model of the physical processes that occur during an earthquake. Starting with the fault geometry, friction constitutive law, initial stress conditions, and assumptions about the condition and response of the near‐fault rocks, a dynamic earthquake rupture simulation calculates the evolution of fault slip and stress over time as part of the elastodynamic numerical solution (Ⓔ see the simulation description in the electronic supplement to this article). The complexity of the computations in a dynamic rupture simulation make it challenging to verify that the computer code is operating as intended, because there are no exact analytic solutions against which these codes’ results can be directly compared. One approach for checking if dynamic rupture computer codes are working satisfactorily is to compare each code’s results with the results of other dynamic rupture codes running the same earthquake simulation benchmark. To perform such a comparison consistently, it is necessary to have quantitative metrics. In this paper, we present a new method for quantitatively comparing the results of dynamic earthquake rupture computer simulation codes.

  12. The AAA-ATPase NVL2 is a telomerase component essential for holoenzyme assembly

    SciTech Connect

    Her, Joonyoung; Chung, In Kwon

    2012-01-20

    Highlights: Black-Right-Pointing-Pointer Identification of the AAA-ATPase NVL2 as a novel hTERT-interacting protein. Black-Right-Pointing-Pointer NVL2 associates with catalytically active telomerase via an interaction with hTERT. Black-Right-Pointing-Pointer NVL2 is a telomerase component essential for holoenzyme assembly. Black-Right-Pointing-Pointer ATP-binding activity of NVL2 is required for hTERT binding and telomerase assembly. -- Abstract: Continued cell proliferation requires telomerase to maintain functional telomeres that are essential for chromosome integrity. Although the core enzyme includes a telomerase reverse transcriptase (TERT) and a telomerase RNA component (TERC), a number of auxiliary proteins have been identified to regulate telomerase assembly, localization, and enzymatic activity. Here we describe the characterization of the AAA-ATPase NVL2 as a novel hTERT-interacting protein. NVL2 interacts and co-localizes with hTERT in the nucleolus. NLV2 is also found in association with catalytically competent telomerase in cell lysates through an interaction with hTERT. Depletion of endogenous NVL2 by small interfering RNA led to a decrease in hTERT without affecting the steady-state levels of hTERT mRNA, thereby reducing telomerase activity, suggesting that NVL2 is an essential component of the telomerase holoenzyme. We also found that ATP-binding activity of NVL2 is required for hTERT binding as well as telomerase assembly. Our findings suggest that NVL2, in addition to its role in ribosome biosynthesis, is essential for telomerase biogenesis and provides an alternative approach for inhibiting telomerase activity in cancer.

  13. Endosomal transport function in yeast requires a novel AAA-type ATPase, Vps4p.

    PubMed Central

    Babst, M; Sato, T K; Banta, L M; Emr, S D

    1997-01-01

    In a late-Golgi compartment of the yeast Saccharomyces cerevisiae, vacuolar proteins such as carboxypeptidase Y (CPY) are actively sorted away from the secretory pathway and transported to the vacuole via a pre-vacuolar, endosome-like intermediate. The vacuolar protein sorting (vps) mutant vps4 accumulates vacuolar, endocytic and late-Golgi markers in an aberrant multilamellar pre-vacuolar compartment. The VPS4 gene has been cloned and found to encode a 48 kDa protein which belongs to the protein family of AAA-type ATPases. The Vps4 protein was purified and shown to exhibit an N-ethylmaleimide-sensitive ATPase activity. A single amino acid change within the AAA motif of Vps4p yielded a protein that lacked ATPase activity and did not complement the protein sorting or morphological defects of the vps4 delta1 mutant. Indeed, when expressed at normal levels in wild-type cells, the mutant vps4 gene acted as a dominant-negative allele. The phenotypic characterization of a temperature-sensitive vps4 allele showed that the immediate consequence of loss of Vps4p function is a defect in vacuolar protein delivery. In this mutant, precursor CPY was not secreted but instead accumulated in an intracellular compartment, presumably the pre-vacuolar endosome. Electron microscopy revealed that upon temperature shift, exaggerated stacks of curved cisternal membranes (aberrant endosome) also accumulated in the vps4ts mutant. Based on these and other observations, we propose that Vps4p function is required for efficient transport out of the pre-vacuolar endosome. PMID:9155008

  14. Age at intracranial aneurysm rupture among generations

    PubMed Central

    Woo, D; Hornung, R; Sauerbeck, L; Brown, R; Meissner, I; Huston, J; Foroud, T; Broderick, J

    2009-01-01

    Background: Previous studies have reported intracranial aneurysm (IA) occurring at young ages in subsequent generations. These studies did not correct for duration of follow-up. Second-generation members who would have their ruptured IA late in life may not be detected due to shorter follow-up time than the first generation. We examined families in which ruptured IA occurred in two consecutive generations for the hypothesis that the second generation (F1) was more likely to have a rupture at a younger age than the older generation (F0). Methods: The Familial Intracranial Aneurysm (FIA) Study is a multicenter, international study recruiting families of ruptured and unruptured IA. All available family members are interviewed. Cox proportional hazards regression models and Kaplan-Meier curves were used to examine differences by generation. Results: Although we found that the F1 generation was more likely to have an aneurysm rupture at a younger age than the F0 generation, we found that this was largely because of a lack of follow-up time in the F1 generation. The F1 generation had 50% the rupture rate of the prior generation. When analyzed by Kaplan-Meier curves, we found a tendency to have a slightly later rupture rate in the F1 generation once time to follow-up was included in the analysis model. Conclusions: Families of ruptured intracranial aneurysm (IA) do not appear to demonstrate “anticipation.” Our finding suggests that genetic epidemiology of ruptured IA should examine all types of variations such as single base-pair changes, deletions, insertions, and other variations that do not demonstrate anticipation. GLOSSARY FIA = familial intracranial aneurysm; IA = intracranial aneurysm; SAH = subarachnoid hemorrhage. PMID:19237697

  15. Student-Athlete Perceptions of a Summer Pre-Enrollment Experience at an NCAA Division I-AAA Institution

    ERIC Educational Resources Information Center

    Dalgety, Michael Franklin

    2012-01-01

    The purpose of this exploratory qualitative study was to examine student-athlete perceptions of the role of summer pre-enrollment in their adjustment and transition to college. The study focused on student-athletes who received athletically-related financial aid at a National Collegiate Athletic Association (NCAA) Division I-AAA institution. The…

  16. Proximal humerus shaft fracture after pectoralis major tendon rupture repair.

    PubMed

    Silverstein, Jeff A; Goldberg, Ben; Wolin, Preston

    2011-06-01

    Surgical repair of a complete pectoralis major tendon rupture at the humeral insertion has superior results compared to nonoperative treatment. To our knowledge, a proximal humerus shaft fracture occurring at the site of the bone trough and cortical drill holes after a pectoralis major tendon rupture repair has not been reported in the literature.A 45-year-old man sustained an acute left pectoralis major tendon rupture at the humeral insertion while performing a bench press maneuver. He underwent acute surgical repair. Approximately 8 weeks postoperatively, the patient fell from a standing height and sustained a proximal humerus shaft fracture through the repair site at the bone trough. Three days after the fracture, the patient underwent open reduction and internal fixation of the proximal humerus shaft fracture and exploration of the pectoralis major tendon repair. The fracture was found to be at the level of the repair site, and the pectoralis major tendon was completely intact to the distal fragment. The fracture healed uneventfully, and the patient regained full motion and strength of his extremity with no limitations.Any type of surgical fixation that creates a hole in the humerus or decreases the cross-sectional area such as a bone trough creates a stress riser. Patients undergoing pectoralis tendon repair that involves violating the humerus with a bone trough or hole have a slight risk of postoperative humerus fracture, especially if sustaining an early traumatic event such as a fall. PMID:21667914

  17. Numerical Simulation of Bleeding from Ruptured Vessels in Microgravity

    NASA Astrophysics Data System (ADS)

    Hitt, Darren L.

    2000-11-01

    With the projected increase of manned space activity in the forthcoming years, there will be a heightened risk of serious injury and/or need for surgical procedures resulting in significant blood loss. The bleeding process may be quite different in a microgravity environment compared with the terrestrial setting. Owing to the removal of normally dominant body forces, the mechanism by which the blood exits a ruptured vessel may be greatly influenced by surface tension. Consequently, blood may be ejected from a blood vessel in the form of droplets rather than a continuous leakage; stable domes of blood surrounding a wound may also be possible. The present study represents the first step towards a theoretical and computational model of the bleeding process in microgravity. A finite element-based numerical model (FIDAP 8.5) is developed for the problem of blood loss from a single ruptured vessel into a quiescent, miscible medium. Computations are carried out in two-dimensions and three-dimensions to investigate the rate of blood loss as a function of flow pulsatility, red blood cell concentration, rupture geometry, and vessel wall elasticity. Blood will be modeled as a Newtonian fluid with a concentration-dependent viscosity (Casson's model).

  18. Extracellular matrix content of ruptured anterior cruciate ligament tissue.

    PubMed

    Young, Kate; Samiric, Tom; Feller, Julian; Cook, Jill

    2011-08-01

    Anterior cruciate ligaments (ACLs) can rupture with simple movements, suggesting that structural changes in the ligament may reduce the loading capacity of the ligament. We aimed to investigate if proteoglycan and collagen levels were different between ruptured and non-ruptured ACLs. We also compared changes in ruptured tissue over time. During arthroscopic knee reconstruction surgery 24 ruptured ACLs were collected from participants (10 females; 14 males; mean age 24 years). Four non-ruptured ACLs were obtained from participants undergoing total knee replacement surgery (one female, three males; mean age 66 years). Western blot analysis was used to characterise core proteins of aggrecan, versican, decorin and biglycan and glycosaminoglycan assays were also conducted. Collagen levels were measured by hydroxyproline (OHPr) assays. Significantly lower levels of collagen, were found in ruptured ACL compared to non-ruptured ACL (p=0.004). Lower levels of both small and large proteoglycans were found in ruptured than non-ruptured ACLs. No correlation was found between time since rupture and proteoglycan or collagen levels. Ruptured ACLs had less collagen and proteoglycans than non-ruptured ACLs. These changes indicate either extracellular matrix protein levels were reduced prior to rupture or levels decreased immediately after rupture. It is possible that the composition and structure of ACLs that rupture are different to normal ACLs, potentially reducing the tissue's ability to withstand loading. An enhanced understanding of the aetiology of ACL injury could help identify individuals who may be predisposed to rupture.

  19. Misdiagnosed Chest Pain: Spontaneous Esophageal Rupture

    PubMed Central

    Inci, Sinan; Gundogdu, Fuat; Gungor, Hasan; Arslan, Sakir; Turkyilmaz, Atila; Eroglu, Atila

    2013-01-01

    Chest pain is one of themost common complaints expressed by patients presenting to the emergency department, and any initial evaluation should always consider life-threatening causes. Esophageal rupture is a serious condition with a highmortality rate. If diagnosed, successful therapy depends on the size of the rupture and the time elapsed between rupture and diagnosis.We report on a 41-year-old woman who presented to the emergency department complaining of left-sided chest pain for two hours. PMID:27122690

  20. Rupture and Migration of an Endovascular Stent in the Brachiocephalic Trunk Causing a Vertebral Steal Syndrome

    SciTech Connect

    Periard, D. Haesler, E.; Hayoz, D.; Von Segesser, L. K.; Qanadli, S. D.

    2008-07-15

    Delayed stent fracture has been observed in many different arteries and may represent a risk factor for restenosis. We describe the case of a delayed rupture of an endovascular brachiocephalic trunk stent. The complete fracture allowed a fragment to migrate distally and tilt, resulting in a hemodynamic pattern similar to that of a prevertebral stenosis with complete inversion of the homolateral vertebral blood flow. The induced vertebral steal syndrome as well as the risk of cerebral embolism was corrected by an aortobrachiocephalic bypass and resection of the ruptured stent.

  1. Pareto front analysis of 6 and 15 MV dynamic IMRT for lung cancer using pencil beam, AAA and Monte Carlo

    NASA Astrophysics Data System (ADS)

    Ottosson, R. O.; Karlsson, A.; Behrens, C. F.

    2010-08-01

    The pencil beam dose calculation method is frequently used in modern radiation therapy treatment planning regardless of the fact that it is documented inaccurately for cases involving large density variations. The inaccuracies are larger for higher beam energies. As a result, low energy beams are conventionally used for lung treatments. The aim of this study was to analyze the advantages and disadvantages of dynamic IMRT treatment planning for high and low photon energy in order to assess if deviating from the conventional low energy approach could be favorable in some cases. Furthermore, the influence of motion on the dose distribution was investigated. Four non-small cell lung cancer cases were selected for this study. Inverse planning was conducted using Varian Eclipse. A total number of 31 dynamic IMRT plans, distributed amongst the four cases, were created ranging from PTV conformity weighted to normal tissue sparing weighted. All optimized treatment plans were calculated using three different calculation algorithms (PBC, AAA and MC). In order to study the influence of motion, two virtual lung phantoms were created. The idea was to mimic two different situations: one where the GTV is located centrally in the PTV and another where the GTV was close to the edge of the PTV. PBC is in poor agreement with MC and AAA for all cases and treatment plans. AAA overestimates the dose, compared to MC. This effect is more pronounced for 15 than 6 MV. AAA and MC both predict similar perturbations in dose distributions when moving the GTV to the edge of the PTV. PBC, however, predicts results contradicting those of AAA and MC. This study shows that PB-based dose calculation algorithms are clinically insufficient for patient geometries involving large density inhomogeneities. AAA is in much better agreement with MC, but even a small overestimation of the dose level by the algorithm might lead to a large part of the PTV being underdosed. It is advisable to use low energy as a

  2. Pareto front analysis of 6 and 15 MV dynamic IMRT for lung cancer using pencil beam, AAA and Monte Carlo.

    PubMed

    Ottosson, R O; Karlsson, A; Behrens, C F

    2010-08-21

    The pencil beam dose calculation method is frequently used in modern radiation therapy treatment planning regardless of the fact that it is documented inaccurately for cases involving large density variations. The inaccuracies are larger for higher beam energies. As a result, low energy beams are conventionally used for lung treatments. The aim of this study was to analyze the advantages and disadvantages of dynamic IMRT treatment planning for high and low photon energy in order to assess if deviating from the conventional low energy approach could be favorable in some cases. Furthermore, the influence of motion on the dose distribution was investigated. Four non-small cell lung cancer cases were selected for this study. Inverse planning was conducted using Varian Eclipse. A total number of 31 dynamic IMRT plans, distributed amongst the four cases, were created ranging from PTV conformity weighted to normal tissue sparing weighted. All optimized treatment plans were calculated using three different calculation algorithms (PBC, AAA and MC). In order to study the influence of motion, two virtual lung phantoms were created. The idea was to mimic two different situations: one where the GTV is located centrally in the PTV and another where the GTV was close to the edge of the PTV. PBC is in poor agreement with MC and AAA for all cases and treatment plans. AAA overestimates the dose, compared to MC. This effect is more pronounced for 15 than 6 MV. AAA and MC both predict similar perturbations in dose distributions when moving the GTV to the edge of the PTV. PBC, however, predicts results contradicting those of AAA and MC. This study shows that PB-based dose calculation algorithms are clinically insufficient for patient geometries involving large density inhomogeneities. AAA is in much better agreement with MC, but even a small overestimation of the dose level by the algorithm might lead to a large part of the PTV being underdosed. It is advisable to use low energy as a

  3. Vortex Imprints at the Wall, But Not in the Bulk, Distinguish Ruptured from Unruptured Intracranial Aneurysms

    NASA Astrophysics Data System (ADS)

    Varble, Nicole; Meng, Hui

    2015-11-01

    Intracranial aneurysms affect 3% of the population. Risk stratification of aneurysms is important, as rupture often leads to death or permanent disability. Image-based CFD analyses of patient-specific aneurysms have identified low and oscillatory wall shear stress to predict rupture. These stresses are sensed biologically at the luminal wall, but the flow dynamics related to aneurysm rupture requires further understanding. We have conducted two studies: one examines vortex dynamics, and the other, high frequency flow fluctuations in patient-specific aneurysms. In the first study, based on Q-criterion vortex identification, we developed two measures to quantify regions within the aneurysm where rotational flow is dominate: the ratio of volume or surface area where Q >0 vs. the total aneurysmal volume or surface area, respectively termed volume vortex fraction (VVF) and surface vortex fraction (SVF). Statistical analysis of 204 aneurysms shows that SVF, but not VVF, distinguishes ruptured from unruptured aneurysms, suggesting that once again, the local flow patterns on the wall is directly relevant to rupture. In the second study, high-resolution CFD (high spatial and temporal resolutions and second-order discretization schemes) on 56 middle cerebral artery aneurysms shows the presence of temporal fluctuations in 8 aneurysms, but such flow instability bears no correlation with rupture. Support for this work was partially provided by NIH grant (R01 NS091075-01) and a grant from Toshiba Medical Systems Corp.

  4. Spontaneous rupture of the abdominal aorta.

    PubMed Central

    Williams, T. G.

    1977-01-01

    Fatal spontaneous rupture of the lower abdominal aorta in a previously healthy 61-year-old woman is reported; the possibility that she had the Ehlers-Danlos syndrome is discussed. Images Fig. 1 PMID:870895

  5. Traumatic Gallbladder Rupture Treated by Laparoscopic Cholecystectomy.

    PubMed

    Egawa, Noriyuki; Ueda, Junji; Hiraki, Masatsugu; Ide, Takao; Inoue, Satoshi; Sakamoto, Yuichiro; Noshiro, Hirokazu

    2016-01-01

    Gallbladder rupture due to blunt abdominal injury is rare. There are few reports of traumatic gallbladder injury, and it is commonly associated with other concomitant visceral injuries. Therefore, it is difficult to diagnose traumatic gallbladder rupture preoperatively when it is caused by blunt abdominal injury. We report a patient who underwent laparoscopic cholecystectomy after an exact preoperative diagnosis of traumatic gallbladder rupture. A 43-year-old man was admitted to our hospital due to blunt abdominal trauma. The day after admission, abdominal pain and ascites increased and a muscular defense sign appeared. Percutaneous drainage of the ascites was performed, and the aspirated fluid was bloody and almost pure bile. He was diagnosed with gallbladder rupture by the cholangiography using the endoscopic retrograde cholangiopancreatography technique. Laparoscopic cholecystectomy was performed safely, and he promptly recovered. If accumulated fluids contain bile, endoscopic cholangiography is useful not only to diagnose gallbladder injury but also to determine the therapeutic strategy. PMID:27462188

  6. Pregnancy-related rupture of arterial aneurysms.

    PubMed

    Barrett, J M; Van Hooydonk, J E; Boehm, F H

    1982-09-01

    Over 50 per cent of ruptured arterial aneurysms in women under the age of 40 are pregnancy-related. The hemodynamic and endocrine changes of pregnancy appear to be the cause of arterial alterations which may lead to new aneurysm formation and/or weakening of preexisting aneurysms. The most commonly reported arteries to have aneurysms rupture during pregnancy are the aorta, cerebral arteries, splenic artery, renal artery, coronary artery, and ovarian artery. In many instances, the rupture of an arterial aneurysm will initially simulate other less serious disease processes, thus delaying the correct diagnosis until a catastrophic event occurs. Early diagnosis and treatment of a ruptured arterial aneurysm are imperative in order to give optimal chances of survival to the mother and fetus.

  7. Traumatic Gallbladder Rupture Treated by Laparoscopic Cholecystectomy

    PubMed Central

    Egawa, Noriyuki; Ueda, Junji; Hiraki, Masatsugu; Ide, Takao; Inoue, Satoshi; Sakamoto, Yuichiro; Noshiro, Hirokazu

    2016-01-01

    Abstract Gallbladder rupture due to blunt abdominal injury is rare. There are few reports of traumatic gallbladder injury, and it is commonly associated with other concomitant visceral injuries. Therefore, it is difficult to diagnose traumatic gallbladder rupture preoperatively when it is caused by blunt abdominal injury. We report a patient who underwent laparoscopic cholecystectomy after an exact preoperative diagnosis of traumatic gallbladder rupture. A 43-year-old man was admitted to our hospital due to blunt abdominal trauma. The day after admission, abdominal pain and ascites increased and a muscular defense sign appeared. Percutaneous drainage of the ascites was performed, and the aspirated fluid was bloody and almost pure bile. He was diagnosed with gallbladder rupture by the cholangiography using the endoscopic retrograde cholangiopancreatography technique. Laparoscopic cholecystectomy was performed safely, and he promptly recovered. If accumulated fluids contain bile, endoscopic cholangiography is useful not only to diagnose gallbladder injury but also to determine the therapeutic strategy. PMID:27462188

  8. Cognitive frames in psychology: demarcations and ruptures.

    PubMed

    Yurevich, Andrey V

    2009-06-01

    As there seems to be a recurrent feeling of crisis in psychology, its present state is analyzed in this article. The author believes that in addition to the traditional manifestations that have dogged psychology since it emerged as an independent science some new features of the crisis have emerged. Three fundamental "ruptures" are identified: the "horizontal" rupture between various schools and trends, the "vertical" rupture between natural science and humanitarian psychology, and the "diagonal" rupture between academic research and applied practice of psychology. These manifestations of the crisis of psychology have recently been compounded by the crisis of its rationalistic foundations. This situation is described in terms of the cognitive systems in psychology which include meta-theories, paradigms, sociodigms and metadigms.

  9. Quadriceps tendon rupture through a superolateral bipartite patella.

    PubMed

    Woods, G William; O'Connor, Daniel P; Elkousy, Hussein A

    2007-10-01

    We report a case of a quadriceps tendon rupture through a bipartite patella. Although quadriceps tendon ruptures and patella fractures are common, rupture through a bipartite patella fragment is rare. This case was managed similar to a quadriceps rupture with an excellent result.

  10. Describing Soils: Calibration Tool for Teaching Soil Rupture Resistance

    ERIC Educational Resources Information Center

    Seybold, C. A.; Harms, D. S.; Grossman, R. B.

    2009-01-01

    Rupture resistance is a measure of the strength of a soil to withstand an applied stress or resist deformation. In soil survey, during routine soil descriptions, rupture resistance is described for each horizon or layer in the soil profile. The lower portion of the rupture resistance classes are assigned based on rupture between thumb and…

  11. [Spontaneous uterine rupture due to uterine leiomyosarcoma].

    PubMed

    Boussouni, Khouloud; Benoulaid, Meryem; Dafiri, Rachida

    2016-01-01

    Uterine sarcomas are rare cancers characterized by clinical and histological polymorphism. They are malignant tumors of poor prognosis. Inaugural manifestation of acute abdomen with hemo-pneumoperitoneum and spontaneous uterine rupture remains exceptional. The authors report the case of a uterine leiomyosarcoma manifesting itself as an inaugural generalized acute peritonitis in a 43 year old woman. Uterine rupture due to malignant tumor was suspected during urgent preoperative imaging (ultrasound and CT scan) and confirmed histologically. PMID:27642425

  12. Fatigue and plaque rupture in myocardial infarction.

    PubMed

    Versluis, Antheunis; Bank, Alan J; Douglas, William H

    2006-01-01

    Plaque rupture plays a role in the majority of acute coronary syndromes. Rupture has been associated with stress concentrations, which are affected by tissue properties and anatomy. In this study rupture was not approached as an acute syndrome, but rather as the culmination of a chronic injury or fatigue process. The aim of our study was to investigate the impact of anatomy, tissue properties, and blood pressure on a fatigue mechanism. Incremental crack propagation was dynamically simulated based on evolving stress distributions. Stresses were resolved by a finite element solver, using vessel stiffness properties derived from in vivo data. Plaque fatigue crack growth per pressure pulse was estimated using an adapted Paris-relation. It was demonstrated that cracks begin at the lumen wall at areas of stress concentration, depending on the shape of the lumen, thickness of the fibrous cap and stiffness of the plaque components. Mean or pulse pressure did not affect initiation location. Cracks extended radially and grew at a rate that was highly dependent on both mean and pulse pressure and on lipid stiffness. Rupture rate depended on blood pressure and lipid stiffness. It was concluded that a fatigue mechanism in a pulsatile cardiovascular pressure environment reconciles clinical evidence of acute plaque rupture at seemingly low stress levels, and it could provide a framework for developing strategies to create a biomechanically benign environment which is least conducive to plaque rupture.

  13. Yield Stress Effects on Mucus Plug Rupture

    NASA Astrophysics Data System (ADS)

    Hu, Yingying; Bian, Shiyao; Grotberg, John C.; Takayama, Shuichi; Grotberg, James B.

    2012-11-01

    Mucus plugs can obstruct airways, resulting in lost gas exchange and inflammation. Yield stress, one of the significant rheological properties of mucus, plays a significant role in plug rupture. We use carbopol 940 gels as mucus simulants to study dynamics of mucus plug rupture in experiments. Yield stress increases with gel concentration increasing (0.1% ~0.3%). The yield stress of the 0.2% gel is about 530 dyn/cm2, which can simulate normal mucus. A 2D PDMS channel is used to simulate a collapsed airway of the 12th generation in a human lung. Plug rupture is driven by a pressure drop of 1.6 ×104 ~ 2.0 ×104 dyn/cm2. Initial plug length varies from half to two times the half channel width. A micro-PIV technique is used to acquire velocity fields during rupture, from which wall shear stress is derived. Plug shortening velocity increases with the pressure drop, but decreases with yield stress or the initial plug length. Wall shear stress increases with yield stress, which indicates more potential damage may occur to epithelial cells when pathologic mucus has a high yield stress. Near the rupture moment, a wall shear stress peak appears at the front of the film deposited by the plug during rupture. This work is supported by NIH: HL84370 and HL85156.

  14. A comparative study of the stress-rupture lifetimes of high-strength carbon fibers

    NASA Astrophysics Data System (ADS)

    Grimes-Ledesma, Lorie

    Stress-rupture life is the time a composite can survive under load at an assigned risk level. The stress-rupture lifetimes of high-strength PAN-based carbon fibers are important to the development and use of lightweight composite structures such as composite overwrapped pressure vessels (COPVs). To quantify appropriate stress-rupture risk levels based on available models, quantification of single fiber variability and lifetime is necessary to understand the variability observed in larger composite structures. In the present work, three PAN-based carbon fibers commonly used in COPV technology were examined, Hexcel IM9, Toray T700, and Toray T1000. The diameter of each fiber type was quantified by measuring samples in the scanning electron microscope and failure loads were determined by performing tensile tests on single fibers. Weibull statistics were used to describe the results. Fractography was performed on IM9 and T1000 fibers after tensile failure. The fracture surfaces are consistent with crack growth from a volume or surface defect. Stress-rupture testing was completed at two stress levels at each fiber type, 97% and 93% of the mean fiber strength for each of the fiber types. The results indicate that differences in stress-rupture life performance exist between the three fiber types. Differences in stress ratio of between 5 and 10% were observed, which may translate to significant difference in stress-rupture life behavior for larger composite structures. The results indicate that a relationship may exist between strength and stress-rupture life. However, if this relationship exists, it is not a simple one, and the relationship is likely complicated by manufacturing.

  15. Differential Sex Response to Aspirin in Decreasing Aneurysm Rupture in Humans and Mice.

    PubMed

    Chalouhi, Nohra; Starke, Robert M; Correa, Tatiana; Jabbour, Pascal M; Zanaty, Mario; Brown, Robert D; Torner, James C; Hasan, David M

    2016-08-01

    We previously found that aspirin decreases the risk of cerebral aneurysm rupture in humans. We aim to assess whether a sex differential exists in the response of human cerebral aneurysms to aspirin and confirm these observations in a mouse model of cerebral aneurysm. A nested case-control analysis from the International Study of Unruptured Intracranial Aneurysms was performed to assess whether a sex differential exists in the response of human cerebral aneurysms to aspirin. A series of experiments were subsequently performed in a mouse model of cerebral aneurysms. Aneurysms were induced with hypertension and elastase injection into mice basal cisterns. We found that aspirin decreased the risk of aneurysm rupture more significantly in men than in women in the International Study of Unruptured Intracranial Aneurysms. In mice, aspirin and cyclooxygenase-2 inhibitor did not affect cerebral aneurysm formation but significantly decreased the incidence of rupture. The incidence of rupture was significantly lower in male versus female mice on aspirin. Gene expression analysis from cerebral arteries showed higher 15-hydroxyprostaglandin dehydrogenase levels in male mice. The rate of cerebral aneurysm rupture was similar in male mice receiving aspirin and 15-hydroxyprostaglandin dehydrogenase inhibitor compared with females receiving aspirin and 15-hydroxyprostaglandin dehydrogenase agonist, signaling a reversal of the sex-differential response to aspirin. Aspirin decreases aneurysm rupture in human and mice, in part through cyclooxygenase-2 pathways. Evidence from animal and human studies suggests a consistent differential effect by sex. 15-Hydroxyprostaglandin dehydrogenase activation in females reduces the incidence of rupture and eliminates the sex-differential response to aspirin. PMID:27296993

  16. Hyperhomocysteinaemia is an independent risk factor of abdominal aortic aneurysm in a Chinese Han population

    PubMed Central

    Liu, Jie; Wei Zuo, Shang; Li, Yue; Jia, Xin; Jia, Sen Hao; Zhang, Tao; Xiang Song, Yu; Qi Wei, Ying; Xiong, Jiang; Hua Hu, Yong; Guo, Wei

    2016-01-01

    The associations between hyperhomocysteinaemia (HHcy), methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism, and abdominal aortic aneurysm (AAA) remain controversial, with only few studies focused on these associations within the Chinese population. We performed subgroup and interaction analyses in a Chinese Han population to investigate these associations. In all, 155 AAA patients and 310 control subjects were evaluated for serum total homocysteine levels and MTHFR C677T polymorphisms. Multiple logistic regression models were used to evaluate the aforementioned associations. Interaction and stratified analyses were conducted according to age, sex, smoking status, drinking status, and chronic disease histories. The multiple logistic analyses showed a significant association between HHcy and AAA but no significant association between MTHFR C677T polymorphism and AAA. The interaction analysis showed that age and peripheral arterial disease played an interactive role in the association between HHcy and AAA, while drinking status played an interactive role in the association between MTHFR C677T polymorphism and AAA. In conclusion, HHcy is an independent risk factor of AAA in a Chinese Han population, especially in the elderly and peripheral arterial disease subgroups. Longitudinal studies and clinical trials aimed to reduce homocysteine levels are warranted to assess the causal nature of these relationships PMID:26865327

  17. AAAS Mass Media Science and Engineering Fellowship Program: Building Communication Skills in Young Scientists

    NASA Astrophysics Data System (ADS)

    Pasco, S.

    2006-12-01

    The AAAS Mass Media Science &Engineering Fellowship program has succeeded in training scientists to become more effective communicators for more than 30 years. The program places advanced science, engineering and mathematics students at media sites to work as science reporters for ten weeks each summer. AAAS places between 15 to 20 students a year at newspapers, magazines and radio stations. Our goal is to create better science communicators who understand their role in fostering the public's understanding of science. Fellows leave the program with a greater awareness of how to communicate complex issues by making the connection as to why people should be interested in certain developments, and more specifically, how they will impact their communities. 2004 AGU Fellow Rei Ueyama put her lessons learned to good use during her Fellowship at the Sacramento Bee. "In a regional paper like The Bee, a (story) also had to have a local touch. I needed to show why people in Sacramento (or California) should bother to read the story. One example is the story I wrote about seeding the ocean with iron particles to fight global warming. Since ocean fertilization is a global issue, I had to clearly specify the reason why The Bee and not The New York Times was running the story. The local angle I chose was to point out that the core group of scientists involved in this study was from Monterey Bay, Calif." Many alumni tell us the program has been an integral force in shaping the course of their career. Similarly, sites often report that having a scientist on staff is an invaluable resource that allows them to cover additional science stories as well as report some technical stories in more depth. The American Geophysical Union has sponsored a Mass Media Fellow since 1997. Sponsorship allows affiliate program partners to establish connections with young professionals in their field. They are then also able to take advantage of the communication skills resident in their alumni base

  18. Interleukin-6 as a Prognostic Biomarker in Ruptured Intracranial Aneurysms

    PubMed Central

    Kao, Hung-Wen; Kuo, Chen-Ling; Huang, Ching-Shan; Tseng, Wan-Min; Lin, Ching-Po

    2015-01-01

    Background Interleukin-6 (IL-6), a proinflammatory cytokine, was found to surge in the cerebral spinal fluid after aneurysmal subarachnoid hemorrhage (SAH). We hypothesized that the plasma level of IL-6 could be an independent biomarker in predicting clinical outcome of patients with ruptured intracranial aneurysm. Methods We prospectively included 53 consecutive patients treated with platinum coil embolization of the ruptured intracranial aneurysm. Plasma IL-6 levels were measured in the blood samples at the orifices of the aneurysms and from peripheral veins. The outcome measure was the modified Rankin Scale one month after SAH. Multiple logistic regression analyses were used to evaluate the associations between the plasma IL-6 levels and the neurological outcome. Results Significant risk factors for the poor outcome were old age, low Glasgow Coma Scale (GCS) on day 0, high Fisher grades, and high aneurysmal and venous IL-6 levels in univariate analyses. Aneurysmal IL-6 levels showed modest to moderate correlations with GCS on day 0, vasospasm grade and Fisher grade. A strong correlation was found between the aneurysmal and the corresponding venous IL-6 levels (ρ = 0.721; P<0.001). In the multiple logistic regression models, the poor 30-day mRS was significantly associated with high aneurysmal IL-6 level (OR, 17.97; 95% CI, 1.51–214.33; P = 0.022) and marginally associated with high venous IL-6 level (OR, 12.71; 95% CI, 0.90–180.35; P = 0.022) after adjusting for dichotomized age, GCS on day 0, and vasospasm and Fisher grades. Conclusions The plasma level of IL-6 is an independent prognostic biomarker that could be used to aid in the identification of patients at high-risk of poor neurological outcome after rupture of the intracranial aneurysm. PMID:26176774

  19. Spontaneous rupture of unscarred uterus in a primigravida with preterm prelabour rupture of membranes.

    PubMed

    Mourad, Wael Sayed; Bersano, Debbra J; Greenspan, Peter B; Harper, Diane Medved

    2015-06-08

    Intrapartum uterine rupture is a true obstetrical emergency. Uterine rupture is associated with severe maternal and fetal morbidity and mortality. It is rare in the unscarred uterus of a primigravida. A 23-year-old primigravida with an unscarred uterus was admitted with preterm prelabour rupture of membranes at 36(+4) weeks of gestation. Abnormal fetal heart monitoring, associated with acute onset of severe abdominopelvic pain, developed on admission. Rupture occurred prior to onset of regular uterine contractions and in the absence of any interventional oxytocin. The neonate had evidence of severe acidosis despite emergency caesarean delivery. This case highlights the importance of maintaining a high index of suspicion for uterine rupture, even in the unlikely setting of a primigravida with an unscarred uterus.

  20. Critical clamp loader processing by an essential AAA+ protease in Caulobacter crescentus.

    PubMed

    Vass, Robert H; Chien, Peter

    2013-11-01

    Chromosome replication relies on sliding clamps that are loaded by energy-dependent complexes. In Escherichia coli, the ATP-binding clamp loader subunit DnaX exists as both long (τ) and short (γ) forms generated through programmed translational frameshifting, but the need for both forms is unclear. Here, we show that in Caulobacter crescentus, DnaX isoforms are unexpectedly generated through partial proteolysis by the AAA+ protease casein lytic proteinase (Clp) XP. We find that the normally processive ClpXP protease partially degrades DnaX to produce stable fragments upon encountering a glycine-rich region adjacent to a structured domain. Increasing the sequence complexity of this region prevents partial proteolysis and generates a τ-only form of DnaX in vivo that is unable to support viability on its own. Growth is restored when γ is provided in trans, but these strains are more sensitive to DNA damage compared with strains that can generate γ through proteolysis. Our work reveals an unexpected mode of partial processing by the ClpXP protease to generate DnaX isoforms, demonstrates that both τ and γ forms of DnaX are required for Caulobacter viability, and identifies a role for clamp loader diversity in responding to DNA damage. The conservation of distinct DnaX isoforms throughout bacteria despite fundamentally different mechanisms for producing them suggests there may be a conserved need for alternate clamp loader complexes during DNA damaging conditions.

  1. Abo1, a conserved bromodomain AAA-ATPase, maintains global nucleosome occupancy and organisation.

    PubMed

    Gal, Csenge; Murton, Heather E; Subramanian, Lakxmi; Whale, Alex J; Moore, Karen M; Paszkiewicz, Konrad; Codlin, Sandra; Bähler, Jürg; Creamer, Kevin M; Partridge, Janet F; Allshire, Robin C; Kent, Nicholas A; Whitehall, Simon K

    2016-01-01

    Maintenance of the correct level and organisation of nucleosomes is crucial for genome function. Here, we uncover a role for a conserved bromodomain AAA-ATPase, Abo1, in the maintenance of nucleosome architecture in fission yeast. Cells lacking abo1(+) experience both a reduction and mis-positioning of nucleosomes at transcribed sequences in addition to increased intragenic transcription, phenotypes that are hallmarks of defective chromatin re-establishment behind RNA polymerase II. Abo1 is recruited to gene sequences and associates with histone H3 and the histone chaperone FACT. Furthermore, the distribution of Abo1 on chromatin is disturbed by impaired FACT function. The role of Abo1 extends to some promoters and also to silent heterochromatin. Abo1 is recruited to pericentromeric heterochromatin independently of the HP1 ortholog, Swi6, where it enforces proper nucleosome occupancy. Consequently, loss of Abo1 alleviates silencing and causes elevated chromosome mis-segregation. We suggest that Abo1 provides a histone chaperone function that maintains nucleosome architecture genome-wide.

  2. Simulation of bifurcated stent grafts to treat abdominal aortic aneurysms (AAA)

    NASA Astrophysics Data System (ADS)

    Egger, J.; Großkopf, S.; Freisleben, B.

    2007-03-01

    In this paper a method is introduced, to visualize bifurcated stent grafts in CT-Data. The aim is to improve therapy planning for minimal invasive treatment of abdominal aortic aneurysms (AAA). Due to precise measurement of the abdominal aortic aneurysm and exact simulation of the bifurcated stent graft, physicians are supported in choosing a suitable stent prior to an intervention. The presented method can be used to measure the dimensions of the abdominal aortic aneurysm as well as simulate a bifurcated stent graft. Both of these procedures are based on a preceding segmentation and skeletonization of the aortic, right and left iliac. Using these centerlines (aortic, right and left iliac) a bifurcated initial stent is constructed. Through the implementation of an ACM method the initial stent is fit iteratively to the vessel walls - due to the influence of external forces (distance- as well as balloonforce). Following the fitting process, the crucial values for choosing a bifurcated stent graft are measured, e.g. aortic diameter, right and left common iliac diameter, minimum diameter of distal neck. The selected stent is then simulated to the CT-Data - starting with the initial stent. It hereby becomes apparent if the dimensions of the bifurcated stent graft are exact, i.e. the fitting to the arteries was done properly and no ostium was covered.

  3. CODAS syndrome is associated with mutations of LONP1, encoding mitochondrial AAA+ Lon protease.

    PubMed

    Strauss, Kevin A; Jinks, Robert N; Puffenberger, Erik G; Venkatesh, Sundararajan; Singh, Kamalendra; Cheng, Iteen; Mikita, Natalie; Thilagavathi, Jayapalraja; Lee, Jae; Sarafianos, Stefan; Benkert, Abigail; Koehler, Alanna; Zhu, Anni; Trovillion, Victoria; McGlincy, Madeleine; Morlet, Thierry; Deardorff, Matthew; Innes, A Micheil; Prasad, Chitra; Chudley, Albert E; Lee, Irene Nga Wing; Suzuki, Carolyn K

    2015-01-01

    CODAS syndrome is a multi-system developmental disorder characterized by cerebral, ocular, dental, auricular, and skeletal anomalies. Using whole-exome and Sanger sequencing, we identified four LONP1 mutations inherited as homozygous or compound-heterozygous combinations among ten individuals with CODAS syndrome. The individuals come from three different ancestral backgrounds (Amish-Swiss from United States, n = 8; Mennonite-German from Canada, n = 1; mixed European from Canada, n = 1). LONP1 encodes Lon protease, a homohexameric enzyme that mediates protein quality control, respiratory-complex assembly, gene expression, and stress responses in mitochondria. All four pathogenic amino acid substitutions cluster within the AAA(+) domain at residues near the ATP-binding pocket. In biochemical assays, pathogenic Lon proteins show substrate-specific defects in ATP-dependent proteolysis. When expressed recombinantly in cells, all altered Lon proteins localize to mitochondria. The Old Order Amish Lon variant (LONP1 c.2161C>G[p.Arg721Gly]) homo-oligomerizes poorly in vitro. Lymphoblastoid cell lines generated from affected children have (1) swollen mitochondria with electron-dense inclusions and abnormal inner-membrane morphology; (2) aggregated MT-CO2, the mtDNA-encoded subunit II of cytochrome c oxidase; and (3) reduced spare respiratory capacity, leading to impaired mitochondrial proteostasis and function. CODAS syndrome is a distinct, autosomal-recessive, developmental disorder associated with dysfunction of the mitochondrial Lon protease.

  4. AAA-ATPase FIDGETIN-LIKE 1 and Helicase FANCM Antagonize Meiotic Crossovers by Distinct Mechanisms

    PubMed Central

    Girard, Chloe; Chelysheva, Liudmila; Choinard, Sandrine; Froger, Nicole; Macaisne, Nicolas; Lehmemdi, Afef; Mazel, Julien; Crismani, Wayne; Mercier, Raphael

    2015-01-01

    Meiotic crossovers (COs) generate genetic diversity and are critical for the correct completion of meiosis in most species. Their occurrence is tightly constrained but the mechanisms underlying this limitation remain poorly understood. Here we identified the conserved AAA-ATPase FIDGETIN-LIKE-1 (FIGL1) as a negative regulator of meiotic CO formation. We show that Arabidopsis FIGL1 limits CO formation genome-wide, that FIGL1 controls dynamics of the two conserved recombinases DMC1 and RAD51 and that FIGL1 hinders the interaction between homologous chromosomes, suggesting that FIGL1 counteracts DMC1/RAD51-mediated inter-homologue strand invasion to limit CO formation. Further, depleting both FIGL1 and the previously identified anti-CO helicase FANCM synergistically increases crossover frequency. Additionally, we showed that the effect of mutating FANCM on recombination is much lower in F1 hybrids contrasting from the phenotype of inbred lines, while figl1 mutation equally increases crossovers in both contexts. This shows that the modes of action of FIGL1 and FANCM are differently affected by genomic contexts. We propose that FIGL1 and FANCM represent two successive barriers to CO formation, one limiting strand invasion, the other disassembling D-loops to promote SDSA, which when both lifted, leads to a large increase of crossovers, without impairing meiotic progression. PMID:26161528

  5. Critical clamp loader processing by an essential AAA+ protease in Caulobacter crescentus

    PubMed Central

    Vass, Robert H.; Chien, Peter

    2013-01-01

    Chromosome replication relies on sliding clamps that are loaded by energy-dependent complexes. In Escherichia coli, the ATP-binding clamp loader subunit DnaX exists as both long (τ) and short (γ) forms generated through programmed translational frameshifting, but the need for both forms is unclear. Here, we show that in Caulobacter crescentus, DnaX isoforms are unexpectedly generated through partial proteolysis by the AAA+ protease casein lytic proteinase (Clp) XP. We find that the normally processive ClpXP protease partially degrades DnaX to produce stable fragments upon encountering a glycine-rich region adjacent to a structured domain. Increasing the sequence complexity of this region prevents partial proteolysis and generates a τ-only form of DnaX in vivo that is unable to support viability on its own. Growth is restored when γ is provided in trans, but these strains are more sensitive to DNA damage compared with strains that can generate γ through proteolysis. Our work reveals an unexpected mode of partial processing by the ClpXP protease to generate DnaX isoforms, demonstrates that both τ and γ forms of DnaX are required for Caulobacter viability, and identifies a role for clamp loader diversity in responding to DNA damage. The conservation of distinct DnaX isoforms throughout bacteria despite fundamentally different mechanisms for producing them suggests there may be a conserved need for alternate clamp loader complexes during DNA damaging conditions. PMID:24145408

  6. CODAS Syndrome Is Associated with Mutations of LONP1, Encoding Mitochondrial AAA+ Lon Protease

    PubMed Central

    Strauss, Kevin A.; Jinks, Robert N.; Puffenberger, Erik G.; Venkatesh, Sundararajan; Singh, Kamalendra; Cheng, Iteen; Mikita, Natalie; Thilagavathi, Jayapalraja; Lee, Jae; Sarafianos, Stefan; Benkert, Abigail; Koehler, Alanna; Zhu, Anni; Trovillion, Victoria; McGlincy, Madeleine; Morlet, Thierry; Deardorff, Matthew; Innes, A. Micheil; Prasad, Chitra; Chudley, Albert E.; Lee, Irene Nga Wing; Suzuki, Carolyn K.

    2015-01-01

    CODAS syndrome is a multi-system developmental disorder characterized by cerebral, ocular, dental, auricular, and skeletal anomalies. Using whole-exome and Sanger sequencing, we identified four LONP1 mutations inherited as homozygous or compound-heterozygous combinations among ten individuals with CODAS syndrome. The individuals come from three different ancestral backgrounds (Amish-Swiss from United States, n = 8; Mennonite-German from Canada, n = 1; mixed European from Canada, n = 1). LONP1 encodes Lon protease, a homohexameric enzyme that mediates protein quality control, respiratory-complex assembly, gene expression, and stress responses in mitochondria. All four pathogenic amino acid substitutions cluster within the AAA+ domain at residues near the ATP-binding pocket. In biochemical assays, pathogenic Lon proteins show substrate-specific defects in ATP-dependent proteolysis. When expressed recombinantly in cells, all altered Lon proteins localize to mitochondria. The Old Order Amish Lon variant (LONP1 c.2161C>G[p.Arg721Gly]) homo-oligomerizes poorly in vitro. Lymphoblastoid cell lines generated from affected children have (1) swollen mitochondria with electron-dense inclusions and abnormal inner-membrane morphology; (2) aggregated MT-CO2, the mtDNA-encoded subunit II of cytochrome c oxidase; and (3) reduced spare respiratory capacity, leading to impaired mitochondrial proteostasis and function. CODAS syndrome is a distinct, autosomal-recessive, developmental disorder associated with dysfunction of the mitochondrial Lon protease. PMID:25574826

  7. Maintenance of mitochondrial genome distribution by mitochondrial AAA+ protein ClpX.

    PubMed

    Kasashima, Katsumi; Sumitani, Megumi; Endo, Hitoshi

    2012-11-01

    The segregation of mitochondrial DNA (mtDNA) is important for the maintenance and transmission of the genome between generations. Recently, we clarified that human mitochondrial transcription factor A (TFAM) is required for equal distribution and symmetric segregation of mtDNA in cultured cells; however, the molecular mechanism involved is largely unknown. ClpX is an ATPase associated with various cellular activities (AAA+) proteins that localize to the mitochondrial matrix and is suggested to associate with mtDNA. In this study, we found that RNAi-mediated knockdown of ClpX in HeLa cells resulted in enlarged mtDNA nucleoids, which is very similar to that observed in TFAM-knockdown cells in several properties. The expression of TFAM protein was not significantly reduced in ClpX-knockdown cells. However, the enlarged mtDNA nucleoids caused by ClpX-knockdown were suppressed by overexpression of recombinant TFAM and the phenotype was not observed in knockdown with ClpP, a protease subunit of ClpXP. Endogenous ClpX and TFAM exist in close vicinity, and ClpX enhanced DNA-binding activity of TFAM in vitro. These results suggest that human ClpX, a novel mtDNA regulator, maintains mtDNA nucleoid distribution through TFAM function as a chaperone rather than as a protease and its involvement in mtDNA segregation. PMID:22841477

  8. Dynamic rupture processes inferred from laboratory microearthquakes

    NASA Astrophysics Data System (ADS)

    Passelègue, François. X.; Schubnel, Alexandre; Nielsen, Stefan; Bhat, Harsha S.; Deldicque, Damien; Madariaga, Raúl

    2016-06-01

    We report macroscopic stick-slip events in saw-cut Westerly granite samples deformed under controlled upper crustal stress conditions in the laboratory. Experiments were conducted under triaxial loading (σ1>σ2=σ3) at confining pressures (σ3) ranging from 10 to 100 MPa. A high-frequency acoustic monitoring array recorded particle acceleration during macroscopic stick-slip events allowing us to estimate rupture speed. In addition, we record the stress drop dynamically and we show that the dynamic stress drop measured locally close to the fault plane is almost total in the breakdown zone (for normal stress >75 MPa), while the friction f recovers to values of f > 0.4 within only a few hundred microseconds. Enhanced dynamic weakening is observed to be linked to the melting of asperities which can be well explained by flash heating theory in agreement with our postmortem microstructural analysis. Relationships between initial state of stress, rupture velocities, stress drop, and energy budget suggest that at high normal stress (leading to supershear rupture velocities), the rupture processes are more dissipative. Our observations question the current dichotomy between the fracture energy and the frictional energy in terms of rupture processes. A power law scaling of the fracture energy with final slip is observed over 8 orders of magnitude in slip, from a few microns to tens of meters.

  9. Rupture of the round window membrane.

    PubMed

    Freeman, P

    1975-01-01

    Considerable interest has been displayed in sudden sensori-neural deafness in recent years, and especially since Blair Simmons postulated that this could be caused by mechanical disruption of the membranes in the inner ear. The literature concerning such reports is reviewed briefly and two cases of rupture of the round window membrane resulting from inner ear barotrauma are reported in detail. Both these cases were experienced divers who had had little difficulty in auto-inflation whilst diving. The first case had progressive sensori-neural deafness with mild vertigo, and tympanotomy revealed rupture of the round window membrane in both ears. These ruptures were repaired with plugs of fat, following which his hearing was restored. The second case developed marked vertigo following a dive and was thought to be suffering from decompression sickness. When the appropriate treatment did not help him, tympanotomy was performed and a rupture of the round membrane was found. This was plugged with fat with a most satisfactory result. Both of these cases had difficulty with autoinflation, and had been aware of such difficulties for some time. Nasal problems were responsible for this, and it is strongly recommended that all divers should have normal nasal function and that they should be educated in the technique of autoinflation, and, in particular, in the importance of avoiding forceful autoinflation at all times. A third case of rupture of the round membrane following an injury to the head is also reported.

  10. ATP-binding sites in brain p97/VCP (valosin-containing protein), a multifunctional AAA ATPase.

    PubMed Central

    Zalk, Ran; Shoshan-Barmatz, Varda

    2003-01-01

    VCP (valosin-containing protein) or p97 is a member of the AAA family (ATPases associated with a variety of cellular activities family), a diverse group of proteins sharing a key conserved AAA module containing duplicate putative ATP-binding sites. Although the functions of the AAA family are related to their putative ATP-binding sites, the binding of ATP to these sites has not yet been demonstrated. In the present study, the ATP-binding site(s) of brain VCP was characterized using the photoreactive ATP analogue, BzATP [3'- O -(4-benzoylbenzoyl)ATP]. Photo-activation of Bz-[alpha-(32)P]ATP resulted in its covalent binding to a 97-kDa purified soluble or membrane-associated protein, identified by amino acid sequencing as VCP. Bz-[alpha-(32)P]ATP covalently bound to the purified homo-hexameric VCP with an apparent high affinity (74-111 nM). A molar stoichiometry of 2.23+/-0.14 BzATP bound per homo-hexameric VCP (n =6) was determined using different methods for analysis of radiolabelling and protein determination. Nucleotides inhibited the binding of Bz-[alpha-(32)P]ATP to VCP with the following efficiency: BzATP>ATP>ADP>>adenosine 5'-[beta,gamma-imido]triphosphate>or=adenosine 5'-[beta,gamma-methylene]triphosphate, whereas AMP, GTP and CTP were ineffective. VCP was observed to possess very low ATPase activity, with nucleotide specificity similar to that for BzATP binding. Conformational changes induced by an alternating site mechanism for ATP binding are suggested as a molecular mechanism for coupling ATP binding to the diverse activities of the AAA family. PMID:12747802

  11. Spontaneous and simultaneous bilateral rupture of the quadriceps tendon. A case report.

    PubMed

    Alpantaki, Kaliopi; Papadokostakis, George; Katonis, Pavlos; Hadjpavlou, Alexander

    2004-02-01

    Simultaneous bilateral rupture of the quadriceps tendon has rarely been reported; it generally occurs in association with chronic metabolic disorders, such as chronic renal failure, obesity, diabetes mellitus and secondary hyperparathyroidism. The case presented here was in an 85-year-old man with no known risk factors, who sustained simultaneous and spontaneous rupture of both quadriceps tendons. The patient suffered from spinal stenosis and degenerative changes in the knee menisci. These findings suggest that instability of the knee due to meniscal damage, and quadriceps weakness as a result of spinal stenosis, may have played a significant role in the pathogenesis of this injury.

  12. PRV sizing for exchanger tube rupture

    SciTech Connect

    Wong, W.Y. )

    1992-02-01

    This paper reports on heat exchanger tube ruptures which is one of the common over-pressure scenarios of pressure relief valve (PRV) design. ASME Code VIII-1 indicates that heat exchangers shall be protected with a relieving device of sufficient capacity to avoid over-pressure in case of an internal failure. But it does not provide any guidance on how to size a PRV and how to define the required relief load. API RP 520 Part I and API RP 521 do offer some guidelines for heat exchanger tube rupture in PRV design, but they are too general to be used to perform a detailed calculation or to do a relief system analysis. Furthermore, API 520's two-phase flow calculation concepts contradict its own assumptions, which makes its design approach infeasible. A detailed PRV design procedure for heat exchanger tube rupture will be discussed.

  13. Spontaneous rupture of the common bile duct.

    PubMed

    Kyzer, S; Bayer, I; Chaimoff, C

    1986-01-01

    Spontaneous rupture of the common bile duct in adults is very rare. The authors report only the 14th case in the Western literature. A 25-year-old woman had signs of peritonitis suggestive of a perforated appendix, but at operation the appendix appeared normal and a large amount of bile was found in the peritoneal cavity. A 2-mm tear was found on the anterior wall of the common bile duct. The patient recovered without complications after T-tube drainage and cholecystectomy. In this patient none of the factors thought to cause spontaneous rupture of the common bile duct were present, so the authors conclude that the case may be classified as idiopathic spontaneous rupture of the common bile duct. PMID:3940592

  14. Augmented repair of acute Achilles tendon ruptures.

    PubMed

    Zell, R A; Santoro, V M

    2000-06-01

    Twenty-five patients who had an acute Achilles tendon rupture were managed with an augmented repair using the gastrocnemius-soleus fascia. All patients healed their repair and there were no re-ruptures. There was one infection. Augmented repair allowed early functional recovery as evidenced by full ankle motion by four to eight weeks, full unassisted weight bearing by three weeks, cessation of braces by four weeks, and return to work by one to six weeks post-operatively. Augmentation adds a sufficient amount of collagen to allow early range of motion and weight bearing without re-rupture. Disadvantages included a long incision, soft tissue prominence, one infection, and sural nerve injury.

  15. Practice Bulletin No. 172: Premature Rupture of Membranes.

    PubMed

    2016-10-01

    Preterm delivery occurs in approximately 12% of all births in the United States and is a major factor that contributes to perinatal morbidity and mortality (1, 2). Preterm premature rupture of membranes (PROM) complicates approximately 3% of all pregnancies in the United States (3). The optimal approach to clinical assessment and treatment of women with term and preterm PROM remains controversial. Management hinges on knowledge of gestational age and evaluation of the relative risks of delivery versus the risks of expectant management (eg, infection, abruptio placentae, and umbilical cord accident). The purpose of this document is to review the current understanding of this condition and to provide management guidelines that have been validated by appropriately conducted outcome-based research when available. Additional guidelines on the basis of consensus and expert opinion also are presented. PMID:27661655

  16. Practice Bulletin No. 172 Summary: Premature Rupture of Membranes.

    PubMed

    2016-10-01

    Preterm delivery occurs in approximately 12% of all births in the United States and is a major factor that contributes to perinatal morbidity and mortality (1, 2). Preterm premature rupture of membranes (PROM) complicates approximately 3% of all pregnancies in the United States (3). The optimal approach to clinical assessment and treatment of women with term and preterm PROM remains controversial. Management hinges on knowledge of gestational age and evaluation of the relative risks of delivery versus the risks of expectant management (eg, infection, abruptio placentae, and umbilical cord accident). The purpose of this document is to review the current understanding of this condition and to provide management guidelines that have been validated by appropriately conducted outcome-based research when available. Additional guidelines on the basis of consensus and expert opinion also are presented. PMID:27661647

  17. Spontaneous Achilles tendon rupture in alkaptonuria

    PubMed Central

    Alajoulin, Omar A.; Alsbou, Mohammed S.; Ja’afreh, Somayya O.; Kalbouneh, Heba M.

    2015-01-01

    Alkaptonuria (AKU) is a rare inborn metabolic disease characterized by accumulation of homogentisic acid (HGA). Excretion of HGA in urine causes darkening of urine and its deposition in connective tissues causes dark pigmentation (ochronosis), early degeneration of articular cartilage, weakening of the tendons, and subsequent rupture. In this case report, we present a rare case of a patient presented with unilateral spontaneous rupture of Achilles tendon due to AKU. The patient developed most of the orthopedic manifestations of the disease earlier than typical presentations. Alkaptonuria patients should avoid strenuous exercises and foot straining especially in patients developing early orthopedic manifestations. PMID:26620992

  18. Thoracic outlet syndrome following breast implant rupture.

    PubMed

    Mistry, Raakhi; Caplash, Yugesh; Giri, Pratyush; Kearney, Daniel; Wagstaff, Marcus

    2015-03-01

    We present a patient with bilateral breast implant rupture who developed severe locoregional silicone granulomatous lymphadenopathy. Poly Implant Prothese silicone implants had been used for bilateral breast augmentation 5 years prior. Extracapsular implant rupture and bilateral axillary lymphadenopathy indicated explantation, capsulectomy, and selective lymph node excision. Histology demonstrated silicone lymphadenopathy with no evidence of malignancy. Over the subsequent 12 months, she developed progressive locoregional lymphadenopathy involving bilateral cervical, axillary, and internal mammary groups, resulting in bilateral thoracic outlet syndrome. We report the unusual presentation, progression, and the ultimate surgical management of this patient. PMID:25878942

  19. Thoracic Outlet Syndrome Following Breast Implant Rupture

    PubMed Central

    Caplash, Yugesh; Giri, Pratyush; Kearney, Daniel; Wagstaff, Marcus

    2015-01-01

    Summary: We present a patient with bilateral breast implant rupture who developed severe locoregional silicone granulomatous lymphadenopathy. Poly Implant Prothese silicone implants had been used for bilateral breast augmentation 5 years prior. Extracapsular implant rupture and bilateral axillary lymphadenopathy indicated explantation, capsulectomy, and selective lymph node excision. Histology demonstrated silicone lymphadenopathy with no evidence of malignancy. Over the subsequent 12 months, she developed progressive locoregional lymphadenopathy involving bilateral cervical, axillary, and internal mammary groups, resulting in bilateral thoracic outlet syndrome. We report the unusual presentation, progression, and the ultimate surgical management of this patient. PMID:25878942

  20. Tendon ruptures: mallet, flexor digitorum profundus.

    PubMed

    Yeh, Peter C; Shin, Steven S

    2012-08-01

    Mallet injuries are the most common closed tendon injury in the athlete. Flexor digitorum profundus ruptures are rare in baseball, but are common injuries in contact sports. The diagnosis for each condition is based on clinical examination, although radiographs should be evaluated for a possible bony component. Treatment for mallet injury depends on the athlete's goals of competition and understanding of the consequences of any treatment chosen. Gripping, throwing, and catching would be restricted or impossible with the injured finger immobilized. Treatment of FDP ruptures is almost always surgical and requires reattachment of the torn tendon to the distal phalanx.

  1. Patellar tendon rupture: an ultrasound case report.

    PubMed

    Berg, Kenneth; Peck, Jeff; Boulger, Creagh; Bahner, David P

    2013-01-01

    This article discusses a case in which ultrasound was the primary modality for diagnosis of traumatic patellar tendon rupture. Traditionally, this diagnosis has been made using MRI. This case highlights the growing need for emergency medicine physicians to become facile with bedside ultrasound and its indications as a supplement to traditional musculoskeletal examination. Normal and pathological patellar tendon examinations with ultrasound are discussed in detail. Furthermore, the advantages of ultrasound over the more traditional imaging modalities of x-ray and MRI in cases where tendon rupture is suspected are discussed.

  2. Rupture propagation behavior and the largest possible earthquake induced by fluid injection into deep reservoirs

    NASA Astrophysics Data System (ADS)

    Gischig, Valentin S.

    2015-09-01

    Earthquakes caused by fluid injection into deep underground reservoirs constitute an increasingly recognized risk to populations and infrastructure. Quantitative assessment of induced seismic hazard, however, requires estimating the maximum possible magnitude earthquake that may be induced during fluid injection. Here I seek constraints on an upper limit for the largest possible earthquake using source-physics simulations that consider rate-and-state friction and hydromechanical interaction along a straight homogeneous fault. Depending on the orientation of the pressurized fault in the ambient stress field, different rupture behaviors can occur: (1) uncontrolled rupture-front propagation beyond the pressure front or (2) rupture-front propagation arresting at the pressure front. In the first case, fault properties determine the earthquake magnitude, and the upper magnitude limit may be similar to natural earthquakes. In the second case, the maximum magnitude can be controlled by carefully designing and monitoring injection and thus restricting the pressurized fault area.

  3. Spontaneous patellar tendon rupture in a case followed up for diagnosis of systemic lupus erythematosus

    PubMed Central

    Albayrak, İlknur; Küçük, Adem; Arslan, Şevket; Özbek, Orhan

    2014-01-01

    Spontaneous patellar tendon rupture is a rare condition that usually occurs secondary to conditions, such as rheumatoid arthritis, systemic lupus erythematosus (SLE), and use of steroids and fluoroquinolones. This paper presents a full-thickness patellar tendon rupture detected with magnetic resonance imaging, which was performed due to pain and swelling that started spontaneously on the front side of the left knee without a history of any trauma, of a 35-year-old male patient who had been followed up for a diagnosis of SLE for approximately 4 months and who had started taking methylprednisolone 4 mg/day 4 months prior, used it for 1 month, and then stopped using it. In patients who are followed up for a diagnosis of SLE, it should be kept in mind that there is a risk of developing a spontaneous tendon rupture secondary to chronic inflammation and use of corticosteroids.

  4. Derivative spectrophotometric analysis of cerebrospinal fluid for the detection of a ruptured cerebral aneurysm

    NASA Astrophysics Data System (ADS)

    Bhadri, P. R.; Majumder, A.; Morgan, C. J.; Pyne, G. J.; Zuccarello, M.; Jauch, E.; Wagner, K. R.; Clark, J. F.; Caffery, J., Jr.; Beyette, Fred R., Jr.

    2003-11-01

    A cerebral aneurysm is a weakened portion of an artery in the brain. When a cerebral aneurysm ruptures, a specific type of bleeding known as a subarachnoid hemorrhage (SAH) occurs. No test exists currently to screen people for the presence of an aneurysm. The diagnosis of a SAH is made after an aneurysm ruptures, and the literature indicates that nearly one-third of patients with a SAH are initially misdiagnosed and subjected to the risks associated with aneurysm re-rupture. For those individuals with a suspected SAH, a computerized tomography (CT) scan of the brain usually demonstrates evidence of the bleeding. However, in a considerable portion of people, the CT scan is unable to detect the blood that has escaped from the blood vessel. For circumstances when a SAH is suspected despite a normal CT scan, physicians make the diagnosis of SAH by performing a spinal tap. A spinal tap uses a needle to sample the cerebrospinal fluid (CSF) collected from the patient"s back; CSF is tainted with blood after the aneurysm ruptures. To distinguish between a common headache and a SAH, a fast and an effective solution is required. We describe the development of an effective detection system integrating hardware and a powerful software interface solution. Briefly, CSF from the patient is aspirated and excited with an appropriate wavelength of light. The software employs spectrophotometric analysis of the output spectra and lays the foundation for the development of portable and user-friendly equipment for detection of a ruptured cerebral aneurysm.

  5. Endovascular coiling of a ruptured basilar apex aneurysm with associated pseudoaneurysm.

    PubMed

    Yanamadala, Vijay; Lin, Ning; Zarzour, Hekmat; Frerichs, Kai U; Walcott, Brian P; Thomas, Ajith J; Puri, Ajit S

    2014-09-01

    Acute intracranial pseudoaneurysms secondary to aneurysmal rupture are a rare entity with no clear evidence-based guidelines for treatment to our knowledge. There are numerous examples of successful treatment of pseudoaneurysms both surgically and endovascularly, the latter mainly within the anterior circulation. Risk of pseudoaneurysm rupture in the acute state during endovascular procedures with subsequent difficulty in controlling the bleeding without sacrificing the feeder artery has led to some reservation in using endovascular treatments more broadly. We report a rare case of a 52-year-old-woman who presented with acute subarachnoid hemorrhage and was found to have a ruptured 5 mm × 8 mm bi-lobulated basilar apex aneurysm on CT angiography. Digital subtraction angiography demonstrated an associated anterior pseudoaneurysm that was formed secondary to the aneurysm rupture. The true aneurysm was successfully coiled with careful avoidance of the pseudoaneurysmal sac. Pseudoaneurysms are frequently identified for the first time during digital subtraction angiography. Recognizing their presence is essential for treatment planning. Acute pseudoaneurysms associated with true aneurysmal rupture can be safely and successfully treated by endovascular coiling of the true aneurysm. Care must be taken to avoid manipulation of the pseudoaneurysmal sac during the embolization.

  6. Fluid-Structure Simulations of a Ruptured Intracranial Aneurysm: Constant versus Patient-Specific Wall Thickness

    PubMed Central

    Hoffmann, T.; Beuing, O.; Jachau, K.; Thévenin, D.; Janiga, G.; Berg, P.

    2016-01-01

    Computational Fluid Dynamics is intensively used to deepen the understanding of aneurysm growth and rupture in order to support physicians during therapy planning. However, numerous studies considering only the hemodynamics within the vessel lumen found no satisfactory criteria for rupture risk assessment. To improve available simulation models, the rigid vessel wall assumption has been discarded in this work and patient-specific wall thickness is considered within the simulation. For this purpose, a ruptured intracranial aneurysm was prepared ex vivo, followed by the acquisition of local wall thickness using μCT. The segmented inner and outer vessel surfaces served as solid domain for the fluid-structure interaction (FSI) simulation. To compare wall stress distributions within the aneurysm wall and at the rupture site, FSI computations are repeated in a virtual model using a constant wall thickness approach. Although the wall stresses obtained by the two approaches—when averaged over the complete aneurysm sac—are in very good agreement, strong differences occur in their distribution. Accounting for the real wall thickness distribution, the rupture site exhibits much higher stress values compared to the configuration with constant wall thickness. The study reveals the importance of geometry reconstruction and accurate description of wall thickness in FSI simulations. PMID:27721898

  7. Patellar and quadriceps tendon ruptures--jumper's knee.

    PubMed

    Kelly, D W; Carter, V S; Jobe, F W; Kerlan, R K

    1984-01-01

    We reviewed 13 patients with end stage jumper's knee, 10 with patellar tendon ruptures, and 3 with ruptures of the quadriceps tendon to evaluate our long-term results in treating these tendon ruptures in an athletic population. The focus was on the natural history, the time until return, and the level of return, to athletic activity. Jumper's knee affected all patients to a varying degree prior to rupture. Basketball was the most common sport involved. At followup, averaging 4 1/2 years, patients underwent functional and clinical, as well as Cybex and roentgenographic, evaluations. Results indicated patellar tendon ruptures, where the ruptures are complete, have a more favorable prognosis than those of the quadriceps tendon which are incomplete. All of the latter patients continued to have quadriceps tendinitis following repair. In both groups, the poor results were obtained in patients with chondromalacia and/or patella alta. Cybex testing yielded results of greater than 100% strength in three patients with patellar tendon ruptures, but no patient with quadriceps rupture had comparable test results. There was no apparent relationship between ruptures and cortisone injections. Patellar and quadriceps tendon ruptures from indirect injury in athletes represent the end stage of jumper's knee and result from repetitive microtrauma. Excellent function usually follows repair of patellar tendon ruptures when surgery is performed early and care is taken to restore normal patellar tendon length. Results of quadriceps ruptures are less satisfactory since these ruptures are usually incomplete and all degenerative tissue may not be involved in the healing response.

  8. AAA+ proteases and their role in distinct stages along the Vibrio cholerae lifecycle.

    PubMed

    Pressler, Katharina; Vorkapic, Dina; Lichtenegger, Sabine; Malli, Gerald; Barilich, Benjamin P; Cakar, Fatih; Zingl, Franz G; Reidl, Joachim; Schild, Stefan

    2016-09-01

    The facultative human pathogen Vibrio cholerae has to adapt to different environmental conditions along its lifecycle by means of transcriptional, translational and post-translational regulation. This study provides a first comprehensive analysis regarding the contribution of the cytoplasmic AAA+ proteases Lon, ClpP and HslV to distinct features of V. cholerae behaviour, including biofilm formation, motility, cholera toxin expression and colonization fitness in the mouse model. While absence of HslV did not yield to any altered phenotype compared to wildtype, absence of Lon or ClpP resulted in significantly reduced colonization in vivo. In addition, a Δlon deletion mutant showed altered biofilm formation and increased motility, which could be correlated with higher expression of V. cholerae flagella gene class IV. Concordantly, we could show by immunoblot analysis, that Lon is the main protease responsible for proteolytic control of FliA, which is required for class IV flagella gene transcription, but also downregulates virulence gene expression. FliA becomes highly sensitive to proteolytic degradation in absence of its anti-sigma factor FlgM, a scenario reported to occur during mucosal penetration due to FlgM secretion through the broken flagellum. Our results confirm that the high stability of FliA in the absence of Lon results in less cholera toxin and toxin corgulated pilus production under virulence gene inducing conditions and in the presence of a damaged flagellum. Thus, the data presented herein provide a molecular explanation on how V. cholerae can achieve full expression of virulence genes during early stages of colonization, despite FliA getting liberated from the anti-sigma factor FlgM. PMID:27345492

  9. A proteomic study of Corynebacterium glutamicum AAA+ protease FtsH

    PubMed Central

    Lüdke, Alja; Krämer, Reinhard; Burkovski, Andreas; Schluesener, Daniela; Poetsch, Ansgar

    2007-01-01

    Background The influence of the membrane-bound AAA+ protease FtsH on membrane and cytoplasmic proteins of Corynebacterium glutamicum was investigated in this study. For the analysis of the membrane fraction, anion exchange chromatography was combined with SDS-PAGE, while the cytoplasmic protein fraction was studied by conventional two-dimensional gel electrophoresis. Results In contrast to the situation in other bacteria, deletion of C. glutamicum ftsH has no significant effect on growth in standard minimal medium or response to heat or osmotic stress. On the proteome level, deletion of the ftsH gene resulted in a strong increase of ten cytoplasmic and membrane proteins, namely biotin carboxylase/biotin carboxyl carrier protein (accBC), glyceraldehyde-3-phosphate dehydrogenase (gap), homocysteine methyltransferase (metE), malate synthase (aceB), isocitrate lyase (aceA), a conserved hypothetical protein (NCgl1985), succinate dehydrogenase A (sdhA), succinate dehydrogenase B (sdhB), succinate dehydrogenase CD (sdhCD), and glutamate binding protein (gluB), while 38 cytoplasmic and membrane-associated proteins showed a decreased abundance. The decreasing amount of succinate dehydrogenase A (sdhA) in the cytoplasmic fraction of the ftsH mutant compared to the wild type and its increasing abundance in the membrane fraction indicates that FtsH might be involved in the cleavage of a membrane anchor of this membrane-associated protein and by this changes its localization. Conclusion The data obtained hint to an involvement of C. glutamicum FtsH protease mainly in regulation of energy and carbon metabolism, while the protease is not involved in stress response, as found in other bacteria. PMID:17254330

  10. Crystal structure of a novel archaeal AAA+ ATPase SSO1545 from Sulfolobus solfataricus

    SciTech Connect

    Xu, Qingping; Rife, Christopher L.; Carlton, Dennis; Miller, Mitchell D.; Krishna, S. Sri; Elsliger, Marc-André; Abdubek, Polat; Astakhova, Tamara; Chiu, Hsiu-Ju; Clayton, Thomas; Duan, Lian; Feuerhelm, Julie; Grzechnik, Slawomir K.; Hale, Joanna; Han, Gye Won; Jaroszewski, Lukasz; Jin, Kevin K.; Klock, Heath E.; Knuth, Mark W.; Kumar, Abhinav; McMullan, Daniel; Morse, Andrew T.; Nigoghossian, Edward; Okach, Linda; Oommachen, Silvya; Paulsen, Jessica; Reyes, Ron; van den Bedem, Henry; Hodgson, Keith O.; Wooley, John; Deacon, Ashley M.; Godzik, Adam; Lesley, Scott A.; Wilson, Ian A.

    2009-08-28

    Signal transduction ATPases with numerous domains (STAND), a large class of P-loop NTPases, belong to AAA+ ATPases. They include AP(apoptotic)-ATPases (e.g., animal apoptosis regulators CED4/Apaf-1, plant disease resistance proteins, and bacterial AfsR-like transcription regulators), NACHT NTPases (e.g. CARD4, NAIP, Het-E-1, TLP1), and several other less well-characterized families. STAND differ from other P-loop NTPases by their unique sequence motifs, which include an hhGRExE (h, hydrophobic; x, any residue) motif at the N-terminal region, a GxP/GxxP motif at the C-terminal region of the NTPase domain, in addition to a C-terminal helical domain and additional domains such as WD40, TPR, LRR or catalytic modules. Despite significant biological interests, structural coverage of STAND proteins is very limited and only two other structures are currently known: the cell death regulators Apaf-1 and CED-4. Here, we report the crystal structure of SSO1545 from Sulfolobus solfataricus, which was determined using the semi-automated, high-throughput pipeline of the Joint Center for Structural Genomics (JCSG; http://www.jcsg.org), as part of the National Institute of General Medical Sciences' Protein Structure Initiative (PSI). SSO1545 (NP-342973.1), a representative of the archaeal STANDs, is a member of Pfam PF01637 and encodes a protein of 356 residues with calculated molecular weight and isoelectric point of 41.7 kD and 8.2, respectively.

  11. Identification of novel biomarkers of abdominal aortic aneurysms by 2D-DIGE and MALDI-MS from AAA-thrombus-conditioned media.

    PubMed

    Martinez-Pinna, Roxana; Lopez, Juan Antonio; Ramos-Mozo, Priscila; Blanco-Colio, Luis M; Camafeita, Emilio; Calvo, Enrique; Meilhac, Olivier; Michel, Jean Baptiste; Egido, Jesús; Martin-Ventura, José Luis

    2013-01-01

    In the search for novel biomarkers, noncandidate-based proteomic strategies open up new opportunities to gain a deeper insight into disease processes regarding their molecular mechanisms, the risk factors involved, and the monitoring of disease progression. To carry out these complex analyses, the combined use of gel electrophoresis with mass spectrometry (MS) represents a powerful choice. In addition, the introduction of protein dye labeling has notably improved the reliability of differential expression studies by increasing the statistical significance of the protein candidates. Here, we describe a strategy where different layers (luminal/abluminal) from the intraluminal thrombus (ILT) of human abdominal aortic aneurysm (AAA) patients were incubated in protein-free medium. Then, the levels of the proteins released were compared by two-dimensional differential in-gel electrophoresis (2D-DIGE) and the proteins of interest identified by MS. We consider that the use of tissue-conditioned media could offer a substantial advantage in the analytical study of biological fluids, as they provide a source of proteins to be released to the bloodstream, which could serve as potential circulating biomarkers.

  12. Primary gastric rupture in 47 horses (1995–2011)

    PubMed Central

    Winfield, Laramie S.; Dechant, Julie E.

    2015-01-01

    The purpose of this retrospective case-control study was to identify factors associated with primary gastric rupture and to investigate if there were differences between etiologies of primary gastric rupture. Compared to the general colic population, Quarter horses were under-represented and Friesians and draft breeds were over-represented in 47 cases of primary gastric ruptures. Horses with primary gastric rupture typically presented with severe clinical and clinicopathological derangements. There were 24 idiopathic gastric ruptures, 20 gastric impaction associated ruptures, and 3 perforating gastric ulcers. Thoroughbred horses were over-represented in the idiopathic gastric rupture group compared to other breeds and etiologies. This study suggests the presence of important breed predispositions for development of gastric rupture. Further study is necessary to identify if these predispositions are associated with management factors or breed-specific disorders. PMID:26345205

  13. [Popliteal cyst rupture due to unusual physical stress].

    PubMed

    Romem, Ayal; Shimony, Avi; Horowitz, Sharon; Horowitz, Jacob

    2007-09-01

    Popliteal cyst rupture is a known phenomenon following strenuous labor or sport activity. We present a case in which popliteal cyst rupture followed an unusual strenuous physical activity--devoted prayer during the holy month of the Ramadan. PMID:17969298

  14. Bilateral infrapatellar tendon rupture in a patient with jumper's knee.

    PubMed

    Rosenberg, J M; Whitaker, J H

    1991-01-01

    This is the fourth case report of bilateral infrapatellar tendon rupture as a result of indirect trauma in a patient without systemic disease. This is the only report we have found of jumper's knee leading to simultaneous infrapatellar tendon ruptures.

  15. An Uncommon Presentation of Breast Implant Rupture

    PubMed Central

    Watson, David I.; Dean, Nicola R.

    2016-01-01

    Summary: Late periprosthetic seroma has lately been concerning for breast implant-associated anaplastic large cell lymphoma. The authors present an uncommon presentation of breast implant rupture with a seroma and skin rash forming 2 years after insertion of the implant. PMID:27579243

  16. Gastric rupture secondary to successful Heimlich manoeuvre.

    PubMed Central

    Majumdar, A.; Sedman, P. C.

    1998-01-01

    A fatal case of gastric rupture following the Heimlich manoeuvre is reported. This life-threatening complication has only been reported previously in seven patients with a high mortality rate. All patients should be assessed immediately following this manoeuvre for any potentially life-threatening complications. Images Figure PMID:10211358

  17. [Splenic rupture--a skateboard accident].

    PubMed

    Kruse, P

    1990-03-01

    A 13-year-old boy presented with persisting abdominal pain after a skateboard accident. Primary clinical and laboratory findings disclosed no signs of intra abdominal bleeding. Ultrasound scanning indicated rupture of the spleen which was confirmed by acute exploratory laparotomy.

  18. Star polymers rupture induced by constant forces

    NASA Astrophysics Data System (ADS)

    García, N. A.; Febbo, M.; Vega, D. A.; Milchev, A.

    2014-10-01

    In this work, we study the breakage process of an unknotted three-arm star-shaped polymer when it is pulled from its free ends by a constant force. The star polymer configuration is described through an array of monomers coupled by anharmonic bonds, while the rupture process is tracked in three-dimensional space by means of Langevin Molecular Dynamics simulations. The interaction between monomers is described by a Morse potential, while a Weeks-Chandler-Anderson energetic contribution accounts for the excluded volume interaction. We explore the effect of the molecular architecture on the distributions of rupture times over a broad interval of pulling forces and star configurations. It was found that the rupture time distribution of the individual star arms is strongly affected by the star configuration imposed by the pulling forces and the length of the arms. We also observed that for large pulling forces the rupture time distributions resemble the dominant features observed for linear polymer chains. The model introduced here provides the basic ingredients to describe the effects of tensile forces on stress-induced degradation of branched macromolecules and polymer networks.

  19. D-Zero Cryostat Supplemental Rupture Disc

    SciTech Connect

    Mulholland, G.T.; /Fermilab

    1987-08-03

    The common relief and rupture disc vent line requires a double disc assembly with vented interspace for accurate disc burst pressures. The first disc must take pump and purge vacuum loading, but be set to operate at 110% of the MAWP, 18.3 psig (ASME code). The available solution is 18.3 psig with a burst tolerance of +/- psig. The interspace should be locally vented by a flow limiting vent valve to decouple the vent line backpressure from the vessel rupture disc. The second disc must take the worst case vent line backpressure, the steady state value found in D-Zero engineering note 3740.000-EN-63 with all three cryostats simultaneously venting at the fire condition into the 4-inch x 6-inch and 6-inch x 8-inch sections. This value is less than 2 psid. The maximum rupture value for the second disc must be less than the minimum rupture value for the first disc less 2 psid i.e. < 16.3.

  20. Fatigue crack propagation analysis of plaque rupture.

    PubMed

    Pei, Xuan; Wu, Baijian; Li, Zhi-Yong

    2013-10-01

    Rupture of atheromatous plaque is the major cause of stroke or heart attack. Considering that the cardiovascular system is a classic fatigue environment, plaque rupture was treated as a chronic fatigue crack growth process in this study. Fracture mechanics theory was introduced to describe the stress status at the crack tip and Paris' law was used to calculate the crack growth rate. The effect of anatomical variation of an idealized plaque cross-section model was investigated. The crack initiation was considered to be either at the maximum circumferential stress location or at any other possible locations around the lumen. Although the crack automatically initialized at the maximum circumferential stress location usually propagated faster than others, it was not necessarily the most critical location where the fatigue life reached its minimum. We found that the fatigue life was minimum for cracks initialized in the following three regions: the midcap zone, the shoulder zone, and the backside zone. The anatomical variation has a significant influence on the fatigue life. Either a decrease in cap thickness or an increase in lipid pool size resulted in a significant decrease in fatigue life. Comparing to the previously used stress analysis, this fatigue model provides some possible explanations of plaque rupture at a low stress level in a pulsatile cardiovascular environment, and the method proposed here may be useful for further investigation of the mechanism of plaque rupture based on in vivo patient data.

  1. An Uncommon Presentation of Breast Implant Rupture.

    PubMed

    Koh, Eugene; Watson, David I; Dean, Nicola R

    2016-05-01

    Late periprosthetic seroma has lately been concerning for breast implant-associated anaplastic large cell lymphoma. The authors present an uncommon presentation of breast implant rupture with a seroma and skin rash forming 2 years after insertion of the implant. PMID:27579243

  2. Pancreatic pseudocyst rupture into the portal vein.

    PubMed

    Dawson, Brian C; Kasa, David; Mazer, Mark A

    2009-07-01

    A patient with a pancreatic pseudocyst rupture into the portal vein with a resultant noninfectious systemic inflammatory response syndrome and subsequent portal vein thrombosis diagnosed by computed tomography and ultrasonography is reported. A review of the existing English literature on this rare complication is also provided. PMID:19561436

  3. Star polymers rupture induced by constant forces.

    PubMed

    García, N A; Febbo, M; Vega, D A; Milchev, A

    2014-10-28

    In this work, we study the breakage process of an unknotted three-arm star-shaped polymer when it is pulled from its free ends by a constant force. The star polymer configuration is described through an array of monomers coupled by anharmonic bonds, while the rupture process is tracked in three-dimensional space by means of Langevin Molecular Dynamics simulations. The interaction between monomers is described by a Morse potential, while a Weeks-Chandler-Anderson energetic contribution accounts for the excluded volume interaction. We explore the effect of the molecular architecture on the distributions of rupture times over a broad interval of pulling forces and star configurations. It was found that the rupture time distribution of the individual star arms is strongly affected by the star configuration imposed by the pulling forces and the length of the arms. We also observed that for large pulling forces the rupture time distributions resemble the dominant features observed for linear polymer chains. The model introduced here provides the basic ingredients to describe the effects of tensile forces on stress-induced degradation of branched macromolecules and polymer networks. PMID:25362341

  4. Primary obstructive megaureter with ruptured kidney.

    PubMed

    Chung, Shiu-Dong; Sun, Hsu-Dong; Yang, Den-Kai; Liao, Chun-Hou

    2009-01-01

    A 17-year-old boy presented to the emergency department for severe left flank pain and gross hematuria 1 hour after playing basketball without significant collision. Laboratory tests showed normal renal function and massive hematuria. Abdominal computed tomography scan disclosed a primary megaureter with ruptured kidney. We successfully treated him with ureteral stenting followed by endoscopic ureterotomy and ureteroneocystostomy.

  5. Ruptured Pseudoaneurysm after Gamma Knife Surgery for Vestibular Schwannoma

    PubMed Central

    MURAKAMI, Mamoru; KAWARABUKI, Kentaro; INOUE, Yasuo; OHTA, Tsutomu

    2016-01-01

    Ruptured aneurysms of anterior inferior cerebellar artery (AICA) after radiotherapy for vestibular schwannoma (VS) are rare, and no definite treatment has been established for distal AICA pseudoaneurysms. We describe a 61-year-old man who underwent Gamma Knife surgery (GKS) for left VS. Follow-up magnetic resonance imaging (MRI) revealed partial regression of the tumor. Twelve years after GKS, he suffered from subarachnoid hemorrhage. Initial angiogram showed no vascular lesions; second left vertebral angiogram, 10 days after admission, demonstrated a pseudoaneurysm in the lateral pontine segment of the left AICA. The proximal portion of the AICA was occluded by a coil. Postoperative MRI revealed an infarction on the left side of the pons and brachium pontis. Although the patient suffered from mild postoperative cerebellar ataxia and facial and abducens nerve palsy, he was discharged 1 month postoperatively requiring no assistance with activities of daily living. Twelve months later, he recovered satisfactorily with a modified Rankin Scale grade of 1, and no recanalization of the aneurysm was found on MR angiography. Endovascular parent artery occlusion for ruptured aneurysms at distal AICA carries the risk of brain stem infarction, but should be considered when no other option is available such as after radiotherapy for VS. PMID:26667081

  6. Ruptured rectal duplication with urogenital abnormality: Unusual presentation

    PubMed Central

    Solanki, Shailesh; Babu, M Narendra; Jadhav, Vinay; Shankar, Gowri; Santhanakrishnan, Ramesh

    2015-01-01

    Rectal duplication (RD) accounts for 5% of alimentary tract duplication. A varied presentation and associated anomalies have been described in the literature. Antenatal rupture of the RD is very rare. We present an unusual case of a ruptured RD associated with urogenital abnormalities in newborn male. We are discussing diagnosis, embryology, management and literature review of ruptured RD. PMID:25552833

  7. 46 CFR 153.1500 - Venting system rupture disks.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ....1500 Venting system rupture disks. The master shall ensure that a relief valve exposed to a cargo after the failure of a rupture disk or breaking pin is cleaned and operates properly before the next cargo... 46 Shipping 5 2010-10-01 2010-10-01 false Venting system rupture disks. 153.1500 Section...

  8. 46 CFR 153.1500 - Venting system rupture disks.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ....1500 Venting system rupture disks. The master shall ensure that a relief valve exposed to a cargo after the failure of a rupture disk or breaking pin is cleaned and operates properly before the next cargo... 46 Shipping 5 2012-10-01 2012-10-01 false Venting system rupture disks. 153.1500 Section...

  9. 46 CFR 153.1500 - Venting system rupture disks.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ....1500 Venting system rupture disks. The master shall ensure that a relief valve exposed to a cargo after the failure of a rupture disk or breaking pin is cleaned and operates properly before the next cargo... 46 Shipping 5 2011-10-01 2011-10-01 false Venting system rupture disks. 153.1500 Section...

  10. 46 CFR 153.1500 - Venting system rupture disks.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ....1500 Venting system rupture disks. The master shall ensure that a relief valve exposed to a cargo after the failure of a rupture disk or breaking pin is cleaned and operates properly before the next cargo... 46 Shipping 5 2014-10-01 2014-10-01 false Venting system rupture disks. 153.1500 Section...

  11. 46 CFR 153.1500 - Venting system rupture disks.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ....1500 Venting system rupture disks. The master shall ensure that a relief valve exposed to a cargo after the failure of a rupture disk or breaking pin is cleaned and operates properly before the next cargo... 46 Shipping 5 2013-10-01 2013-10-01 false Venting system rupture disks. 153.1500 Section...

  12. Rupture Paths in Kappa-Maps: Quantitative Insights on Heterogeneous Earthquake Ruptures From Energy Arguments.

    NASA Astrophysics Data System (ADS)

    Ampuero, J.; Ripperger, J.; Mai, M.

    2005-12-01

    Earthquake rupture is a notoriously complex process, at all observable scales. Although heterogeneities of strength and initial stress contribute to this rupture complexity, a systematic approach to quantify their effect has not yet been attempted. For instance, little is known about the relation between the final size of an earthquake and the statistical properties of initial strength excess fields. Canonical cases of dynamic rupture (e.g. uniform initial stress and friction properties), can be characterized by two non-dimensional numbers: the S-parameter (ratio of strength excess to stress drop) and the Kappa-parameter (ratio of static energy release rate to fracture energy, Madariaga and Olsen, 2000). The latter was introduced as a global parameter, involving the fault depth or asperity size as the fundamental scale. However, because faults contain heterogeneities at all scales it is not clear how a single scale-length may be relevant to define Kappa. We define here a scale-dependent Kappa-map, based on classical energy concepts in fracture mechanics. In 2D these maps can be defined exactly, and their efficient computation is implemented as a series of FFT-convolutions, by scaled analytical filters related to stress intensity factor weight functions. For given heterogeneous stress drop and fracture energy, such Kappa-maps are useful to predict nucleation properties and final moment, as we illustrate through increasingly complex examples complemented by dynamic rupture simulations. Other properties that can be derived from the 2D Kappa-maps, with additional assumptions, include radiated energy and rupture directivity. In 3D, the shape of the rupture front is unknown a priori and the energy release rate G might be non-uniform along the front. We therefore propose an approximate definition of Kappa in which G is estimated on circular patches. Comparisons with 3D dynamic rupture simulations on highly heterogeneous initial stress fields show that the final moment can

  13. Multicenter Orthopaedic Outcome Network Early Anti-inflammatory Treatment in Patients with Acute ACL Tear” (MOON-AAA) Clinical Trial

    PubMed Central

    Lattermann, Christian; Proffitt, Mary; Huston, Laura J.; Gammon, Lee; Johnson, Darren L.; Kraus, Virginia B.; Spindler, Kurt P.

    2016-01-01

    Objectives: We present the early results from the “Multicenter Orthopaedic Outcome Network Early Anti-inflammatory Treatment in Patients with Acute ACL Tear and Painful Effusions” (MOON-AAA) clinical trial (figure 1). This trial allows for a well controlled prospective cohort of patients with isolated ACL injury at risk for OA. We compared the effect of a single versus a repeated dosage of Kenalog within the first two weeks after ACL injury and its effect on chondral degradation in the first 4 weeks prior to surgical reconstruction of the ACL. Methods: 49 patients with isolated ACL tears were enrolled. Knee joints were aspirated and patients received an injection with 40 mg Kenalog either within 4 days, 10 days, both time points or not at all (saline injection control). Serum, synovial fluid and urine were collected at 3 time points. Permutated block randomization, triple blinding, independent monitoring and standardized x-ray was performed to comply with GCP standards. Patient reported outcomes were collected at 6 time points up to 6 months post-ACL reconstruction(IKDC, KOOS and Marx activity level). A standardized synovial fluid biomarker panel was analyzed according to OARSI guidelines. Statistical analysis were performed using SAS mixed models analysis. Results: Serum analysis shows significant change after injury. Chondrodegradatory markers such as CTX-II, MMP-1 and MMP-3 as well as COMP indicate a progressive destruction of chondral matrix and collagen breakdown . There is a dramatic (250%) increase of CTX-II in the first 4 weeks. Matrix proteins such as MMP-1 and 3 as well as COMP show an initial increase and then a steep decline (see figure 1). Inflammatory markers (IL-1 alpha, IL-1beta, IRAP) show a decline from the time of injury. IL-1 alpha, however shows a dramatic uptake after week 2. This longitudinal data confirms a dramatic onset of early osteoarthritic biomarker profiles immediately after ACL injury as measured in synovial fluid

  14. Isolated Total Rupture of Extraocular Muscles

    PubMed Central

    Chen, Jingchang; Kang, Ying; Deng, Daming; Shen, Tao; Yan, Jianhua

    2015-01-01

    Abstract Total rupture of extraocular muscles is an infrequent clinical finding. Here we conducted this retrospective study to evaluate their causes of injury, clinical features, imaging, surgical management, and final outcomes in cases of isolated extraocular muscle rupture at a tertiary center in China. Thirty-six patients were identified (24 men and 12 women). Mean age was 34 years (range 2–60). The right eye was involved in 21 patients and the left 1 in 15. A sharp object or metal hook was the cause of this lesion in 16 patients, sinus surgery in 14 patients, traffic accident in 3 patients, orbital surgery in 2 patients, and conjunctive tumor surgery in 1 patient. The most commonly involved muscles were medial (18 patients) and inferior rectus muscles (13 patients). The function of the ruptured muscles revealed a scale of −3 to −4 defect of ocular motility and the amount of deviation in primary position varied from 10 to 140 PD (prism diopter). Computerized tomography (CT) confirmed the presence of ruptured muscles. An end-to-end muscle anastomosis was performed and 3 to 5 mm of muscle was resected in 23 patients. When the posterior border of the injured muscle could not be identified (13 patients), a partial tendon transposition was performed, together with recession of the antagonist in most patients, whereas a recession of the antagonist muscle plus a resection of the involved muscle with or without nasal periosteal fixation was performed in the remaining patients. After an average of 16.42 months of follow-up an excellent result was achieved in 23 patients and results of 13 patients were considered as a failure. In most patients, the posterior border of the ruptured muscle can be identified and an early surgery can be performed to restore function. Alternatively, a partial tendon transposition should be performed. When muscular rupture is suspected, an early orbital CT is required to confirm this possibility, which can then verify the necessity for

  15. Association between MTHFR C677T polymorphism and abdominal aortic aneurysm risk

    PubMed Central

    Liu, Jie; Jia, Xin; Li, Haifeng; Jia, Senhao; Zhang, Minhong; Xu, Yongle; Du, Xin; Zhang, Nianrong; Lu, Weihang; Guo, Wei

    2016-01-01

    Abstract Background: Abdominal aortic aneurysm (AAA) is a life-threatening condition. A number of studies reported the association between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and AAA risk, but substantial controversial findings were observed and the strength of the association remains unclear. Objective: The aim of this study was to investigate the aforementioned association in the overall population and different subgroups. Methods: PUBMED and EMBASE databases were searched until March 2016 to identify eligible studies, restricted to humans and articles published in English. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the susceptibility to AAA. Subgroup meta-analyses were conducted on features of the population, such as ethnicity, sex of the participants, and study design (source of control). Results: Twelve case–control studies on MTHFR C677T polymorphism and AAA risk, including 3555 cases and 6568 case-free controls were identified. The results revealed no significant association between the MTHFR C677T polymorphism and AAA risk in the overall population and within Caucasian or Asian subpopulations in all 5 genetic models. Further subgroup meta-analysis indicated that significantly increased risks were observed among cases with a mean age <70 years (OR = 1.73, 95% CI = 1.10–2.12, P = 0.02), cases with prevalence of smoking <60% (OR = 1.39, 95% CI = 1.02–1.90, P = 0.04), and cases with aneurysm diameter ≥55 mm (OR = 1.55, 95% CI = 1.07–2.24, P = 0.02) in the dominant genetic model. No publication bias was detected in the present study. Conclusion: In conclusion, our comprehensive meta-analysis suggests that the MTHFR C677T polymorphism may play an important role in AAA susceptibility, especially in younger, non-smoking, larger AAA-diameter subgroups of patients PMID:27603386

  16. Endoport-Assisted Microsurgical Treatment of a Ruptured Periventricular Aneurysm

    PubMed Central

    Chen, Ching-Jen; Caruso, James; Buell, Thomas; Crowley, R. Webster; Liu, Kenneth C.

    2016-01-01

    Background and Importance. Ruptured periventricular aneurysms in patients with moyamoya disease represent challenging pathologies. The most common methods of treatment include endovascular embolization and microsurgical clipping. However, rare cases arise in which the location and anatomy of the aneurysm make these treatment modalities particularly challenging. Clinical Presentation. We report a case of a 34-year-old female with moyamoya disease who presented with intraventricular hemorrhage. CT angiography and digital subtraction angiography revealed an aneurysm located in the wall of the atrium of the right lateral ventricle. Distal endovascular access was not possible, and embolization risked the sacrifice of arteries supplying critical brain parenchyma. Using the BrainPath endoport system, the aneurysm was able to be accessed. Since the fusiform architecture of the aneurysm prevented clip placement, the aneurysm was ligated with electrocautery. Conclusion. We demonstrate the feasibility of endoport-assisted approach for minimally invasive access and treatment of uncommon, distally located aneurysms. PMID:27195160

  17. Endoport-Assisted Microsurgical Treatment of a Ruptured Periventricular Aneurysm.

    PubMed

    Chen, Ching-Jen; Caruso, James; Starke, Robert M; Ding, Dale; Buell, Thomas; Crowley, R Webster; Liu, Kenneth C

    2016-01-01

    Background and Importance. Ruptured periventricular aneurysms in patients with moyamoya disease represent challenging pathologies. The most common methods of treatment include endovascular embolization and microsurgical clipping. However, rare cases arise in which the location and anatomy of the aneurysm make these treatment modalities particularly challenging. Clinical Presentation. We report a case of a 34-year-old female with moyamoya disease who presented with intraventricular hemorrhage. CT angiography and digital subtraction angiography revealed an aneurysm located in the wall of the atrium of the right lateral ventricle. Distal endovascular access was not possible, and embolization risked the sacrifice of arteries supplying critical brain parenchyma. Using the BrainPath endoport system, the aneurysm was able to be accessed. Since the fusiform architecture of the aneurysm prevented clip placement, the aneurysm was ligated with electrocautery. Conclusion. We demonstrate the feasibility of endoport-assisted approach for minimally invasive access and treatment of uncommon, distally located aneurysms. PMID:27195160

  18. Earthquake ruptures modulated by waves in damaged fault zones

    NASA Astrophysics Data System (ADS)

    Huang, Yihe; Ampuero, Jean-Paul; Helmberger, Don V.

    2014-04-01

    Faults are usually surrounded by damaged zones of lower elastic moduli and seismic wave velocities than their host rocks. If the interface between the damaged rocks and host rocks is sharp enough, earthquakes happening inside the fault zone generate reflected waves and head waves, which can interact with earthquake ruptures and modulate rupture properties such as rupture speed, slip rate, and rise time. We find through 2-D dynamic rupture simulations the following: (1) Reflected waves can induce multiple slip pulses. The rise time of the primary pulse is controlled by fault zone properties, rather than by frictional properties. (2) Head waves can cause oscillations of rupture speed and, in a certain range of fault zone widths, a permanent transition to supershear rupture with speeds that would be unstable in homogeneous media. (3) Large attenuation smears the slip rate function and delays the initial acceleration of rupture speed but does not affect significantly the rise time or the period of rupture speed oscillations. (4) Fault zones cause a rotation of the background stress field and can induce plastic deformations on both extensional and compressional sides of the fault. The plastic deformations are accumulated both inside and outside the fault zone, which indicates a correlation between fault zone development and repeating ruptures. Spatially periodic patterns of plastic deformations are formed due to oscillating rupture speed, which may leave a permanent signature in the geological record. Our results indicate that damaged fault zones with sharp boundaries promote multiple slip pulses and supershear ruptures.

  19. Rupture Process During the 2015 Illapel, Chile Earthquake: Zigzag-Along-Dip Rupture Episodes

    NASA Astrophysics Data System (ADS)

    Okuwaki, Ryo; Yagi, Yuji; Aránguiz, Rafael; González, Juan; González, Gabriel

    2016-04-01

    We constructed a seismic source model for the 2015 M W 8.3 Illapel, Chile earthquake, which was carried out with the kinematic waveform inversion method adopting a novel inversion formulation that takes into account the uncertainty in the Green's function, together with the hybrid backprojection method enabling us to track the spatiotemporal distribution of high-frequency (0.3-2.0 Hz) sources at high resolution by using globally observed teleseismic P-waveforms. A maximum slip amounted to 10.4 m in the shallow part of the seismic source region centered 72 km northwest of the epicenter and generated a following tsunami inundated along the coast. In a gross sense, the rupture front propagated almost unilaterally to northward from the hypocenter at <2 km/s, however, in detail the spatiotemporal slip distribution also showed a complex rupture propagation pattern: two up-dip rupture propagation episodes, and a secondary rupture episode may have been triggered by the strong high-frequency radiation event at the down-dip edge of the seismic source region. High-frequency sources tends to be distributed at deeper parts of the slip area, a pattern also documented in other subduction zone megathrust earthquakes that may reflect the heterogeneous distribution of fracture energy or stress drop along the fault. The weak excitation of high-frequency radiation at the termination of rupture may represent the gradual deceleration of rupture velocity at the transition zone of frictional property or stress state between the megathrust rupture zone and the swarm area.

  20. Brittle dynamic damage due to earthquake rupture

    NASA Astrophysics Data System (ADS)

    Bhat, Harsha; Thomas, Marion

    2016-04-01

    The micromechanical damage mechanics formulated by Ashby and Sammis, 1990, and generalized by Deshpande and Evans 2008 has been extended to allow for a more generalized stress state and to incorporate an experimentally motivated new crack growth (damage evolution) law that is valid over a wide range of loading rates. This law is sensitive to both the crack tip stress field and its time derivative. Incorporating this feature produces additional strain-rate sensitivity in the constitutive response. The model is also experimentally verified by predicting the failure strength of Dionysus-Pentelicon marble over wide range of strain rates. We then implement this constitutive response to understand the role of dynamic brittle off-fault damage on earthquake ruptures. We show that off-fault damage plays an important role in asymmetry of rupture propagation and is a source of high-frequency ground motion in the near source region.

  1. An unusual diagnosis of splenic rupture

    PubMed Central

    Roche, Matthew; Maloku, Fatmir; Abdel-Aziz, Tarek Ezzat

    2014-01-01

    A 22-year-old woman presented with a 3-day history of worsening epigastric pain, non-productive cough and vomiting. On examination she was pale and had abdominal tenderness predominant in the right upper quadrant. Abdominal ultrasound excluded the presence of gall stones, but was unable to rule out free fluid in the abdomen. CT demonstrated extensive high-density ascites; however, no source of bleeding could be demonstrated. Clinically the patient's condition deteriorated, and an exploratory laparotomy was performed. In theatre the splenic capsule was found to have detached from the splenic body and emergency splenectomy was performed. Virology serology later demonstrated acute cytomegalovirus (CMV) infection, although tissue microscopy and CMV staining were negative. No other cause of rupture was found. The interesting aspects of this case include the poor correlation between initial presenting symptoms and subsequent diagnosis, the difficulty encountered in making a firm diagnosis and the atypical cause of rupture. PMID:25293683

  2. [Postmortem gastrointestinal ruptures in burn cadavers].

    PubMed

    Schneider, V; Pietrzak, T; Klöppel, I

    1986-01-01

    The report informs on ruptures within the area of the gastro-intestinal tract of two siblings (2 and 3 years of age) that were fatally burned in their apartment. The ruptures are obviously pointing to an "explosive-like" evaporation of the watery part of the gastro-intestinal contents under the influence of the heat, at impeded pressure balance through shrinking of the esophagus caused by the heat in the upper area and the closure of the pylorus. Of significance here is surely also the shrinking of the gastro-intestinal wall caused by the heat and the thin abdominal walls which were not likely to have acted as "heat insulators". These findings are a supplement to the burn hematoma of the stomach as described by Berg and Schumann (1985). PMID:3963991

  3. Computational model of retinal photocoagulation and rupture

    NASA Astrophysics Data System (ADS)

    Sramek, Christopher; Paulus, Yannis M.; Nomoto, Hiroyuki; Huie, Phil; Palanker, Daniel

    2009-02-01

    In patterned scanning laser photocoagulation, shorter duration (< 20 ms) pulses help reduce thermal damage beyond the photoreceptor layer, decrease treatment time and minimize pain. However, safe therapeutic window (defined as the ratio of rupture threshold power to that of light coagulation) decreases for shorter exposures. To quantify the extent of thermal damage in the retina, and maximize the therapeutic window, we developed a computational model of retinal photocoagulation and rupture. Model parameters were adjusted to match measured thresholds of vaporization, coagulation, and retinal pigment epithelial (RPE) damage. Computed lesion width agreed with histological measurements in a wide range of pulse durations and power. Application of ring-shaped beam profile was predicted to double the therapeutic window width for exposures in the range of 1 - 10 ms.

  4. Creep rupture behavior of Stirling engine materials

    NASA Technical Reports Server (NTRS)

    Titran, R. H.; Scheuerman, C. M.; Stephens, J. R.

    1985-01-01

    The automotive Stirling engine, being investigated jointly by the Department of Energy and NASA Lewis as an alternate to the internal combustion engine, uses high-pressure hydrogen as the working fluid. The long-term effects of hydrogen on the high temperature strength properties of materials is relatively unknown. This is especially true for the newly developed low-cost iron base alloy NASAUT 4G-A1. This iron-base alloy when tested in air has creep-rupture strengths in the directionally solidified condition comparable to the cobalt base alloy HS-31. The equiaxed (investment cast) NASAUT 4G-A1 has superior creep-rupture to the equiaxed iron-base alloy XF-818 both in air and 15 MPa hydrogen.

  5. Rupture of the round window membrane.

    PubMed

    Taylor, P H; Bicknell, P G

    1976-01-01

    A case of sudden deafness due to rupture of the round window membrane is presented. Nineteen similar cases have previously been reported in the literature. In a review of these twenty patients, it is noted that a history of concurrent physical effort or barotrauma was present in eighteen. This supports the view that the injury is produced by pressure changes acting either along the cochlear aqueduct (the explosive route) or, directly on the middle ear structures (the implosive route). At operation, the rupture may be difficult to see, and a separate leak from the oval window may be present. The timing of any surgical intervention is important. The authors recommend that this should be deferred for one week after the onset of symptoms, as the fistula may heal spontaneously. If no definite improvement has occurred at the end of this time, then tympanotomy should be undertaken during the next week.

  6. Liquid salt environment stress-rupture testing

    DOEpatents

    Ren, Weiju; Holcomb, David E.; Muralidharan, Govindarajan; Wilson, Dane F.

    2016-03-22

    Disclosed herein are systems, devices and methods for stress-rupture testing selected materials within a high-temperature liquid salt environment. Exemplary testing systems include a load train for holding a test specimen within a heated inert gas vessel. A thermal break included in the load train can thermally insulate a load cell positioned along the load train within the inert gas vessel. The test specimen can include a cylindrical gage portion having an internal void filled with a molten salt during stress-rupture testing. The gage portion can have an inner surface area to volume ratio of greater than 20 to maximize the corrosive effect of the molten salt on the specimen material during testing. Also disclosed are methods of making a salt ingot for placement within the test specimen.

  7. Surgical treatment of gastrocnemius muscle ruptures.

    PubMed

    Cheng, Yu; Yang, Hui-lin; Sun, Zhi-yong; Ni, Li; Zhang, Hong-tao

    2012-11-01

    Rupture of the medial head of the gastrocnemius, known as "tennis leg", typically occurs when the muscle has been overstretched by dorsiflexion of the ankle with full knee extension. The classic clinical presentation is a middle-aged person who complains of sports-related acute pain in the mid portion of the calf, associated with a snapping sensation. Magnetic resonance imaging (MRI) or ultrasound is often required to evaluate patients with this condition. This injury is usually managed non-operatively, surgical treatment rarely being indicated according to published reports. One case of longstanding and one of recent rupture of the musculotendinous junction of the medial head of the gastrocnemius that were successfully treated by surgical repair are presented here and the MRI characteristics and indications for surgery are discussed.

  8. Rupture directivity of moderate earthquakes in northern California

    USGS Publications Warehouse

    Seekins, Linda C.; Boatwright, John

    2010-01-01

    We invert peak ground velocity and acceleration (PGV and PGA) to estimate rupture direction and rupture velocity for 47 moderate earthquakes (3.5≥M≥5.4) in northern California. We correct sets of PGAs and PGVs recorded at stations less than 55–125 km, depending on source depth, for site amplification and source–receiver distance, then fit the residual peak motions to the unilateral directivity function of Ben-Menahem (1961). We independently invert PGA and PGV. The rupture direction can be determined using as few as seven peak motions if the station distribution is sufficient. The rupture velocity is unstable, however, if there are no takeoff angles within 30° of the rupture direction. Rupture velocities are generally subsonic (0.5β–0.9β); for stability, we limit the rupture velocity at v=0.92β, the Rayleigh wave speed. For 73 of 94 inversions, the rupture direction clearly identifies one of the nodal planes as the fault plane. The 35 strike-slip earthquakes have rupture directions that range from nearly horizontal (6 events) to directly updip (5 events); the other 24 rupture partly along strike and partly updip. Two strike-slip earthquakes rupture updip in one inversion and downdip in the other. All but 1 of the 11 thrust earthquakes rupture predominantly updip. We compare the rupture directions for 10 M≥4.0 earthquakes to the relative location of the mainshock and the first two weeks of aftershocks. Spatial distributions of 8 of 10 aftershock sequences agree well with the rupture directivity calculated for the mainshock.

  9. Fan-structure waves in shear ruptures

    NASA Astrophysics Data System (ADS)

    Tarasov, Boris

    2016-04-01

    This presentation introduces a recently identified shear rupture mechanism providing a paradoxical feature of hard rocks - the possibility of shear rupture propagation through the highly confined intact rock mass at shear stress levels significantly less than frictional strength. According to the fan-mechanism the shear rupture propagation is associated with consecutive creation of small slabs in the fracture tip which, due to rotation caused by shear displacement of the fracture interfaces, form a fan-structure representing the fracture head. The fan-head combines such unique features as: extremely low shear resistance (below the frictional strength), self-sustaining stress intensification in the rupture tip (providing easy formation of new slabs), and self-unbalancing conditions in the fan-head (making the failure process inevitably spontaneous and violent). An important feature of the fan-mechanism is the fact that for the initial formation of the fan-structure an enhanced local shear stress is required, however, after completion of the fan-structure it can propagate as a dynamic wave through intact rock mass at shear stresses below the frictional strength. Paradoxically low shear strength of pristine rocks provided by the fan-mechanism determines the correspondingly low transient strength of the lithosphere, which favours generation of new earthquake faults in the intact rock mass adjoining pre-existing faults in preference to frictional stick-slip instability along these faults. The new approach reveals an alternative role of pre-existing faults in earthquake activity: they represent local stress concentrates in pristine rock adjoining the fault where special conditions for the fan-mechanism nucleation are created, while further dynamic propagation of the new fault (earthquake) occurs at low field stresses even below the frictional strength.

  10. Wrapped Wire Detects Rupture Of Pressure Vessel

    NASA Technical Reports Server (NTRS)

    Hunt, James B.

    1990-01-01

    Simple, inexpensive technique helps protect against damage caused by continuing operation of equipment after rupture or burnout of pressure vessel. Wire wrapped over area on outside of vessel where breakthrough most likely. If wall breaks or burns, so does wire. Current passing through wire ceases, triggering cutoff mechanism stopping flow in vessel to prevent further damage. Applied in other situations in which pipes or vessels fail due to overpressure, overheating, or corrosion.

  11. An unusual presentation of bronchial rupture.

    PubMed

    Goktalay, Tugba; Yaldiz, Sadik; Ozgen Alpaydin, Aylin; Goktan, Cihan; Celik, Pinar

    2011-06-01

    Persistent hydropneumothorax was diagnosed in a 62-year-old female with a history of blunt trauma, although she was treated with chest tube and closed underwater seal drainage. Computed tomography and fiberoptic bronchoscopy findings were consistent with "fallen lung" syndrome. Fiberoptic bronchoscopy also found a cavitary lesion at the right tracheobronchial angle. Forceps biopsy of the cavitary lesion indicated bronchogenic carcinoma. Our final diagnosis was tracheobronchial complete rupture and fallen lung syndrome secondary to malignancy. PMID:21333086

  12. [Bilateral rupture of the quadriceps tendon].

    PubMed

    Modrego, Francisco J; Molina, Juan

    2004-01-01

    Simultaneous, bilateral, and spontaneous rupture of the quadriceps tendon is a very rare injury. Individuals with this injury are usually predisposed by chronic renal disease with secondary hyperparathyroidism, gout, diabetes, and lupus erythematosus. Often, primary diagnostic confusion can lead to a delay in treatment. Two cases of a bilateral lesion of the quadriceps tendon, that were treated surgically using the technique of Scuderi, followed by an intense rehabilitation programme, are presented. Surgical treatment yields satisfactory results.

  13. The – Not So – Solid 5.5 cm Threshold for Abdominal Aortic Aneurysm Repair: Facts, Misinterpretations, and Future Directions

    PubMed Central

    Kontopodis, Nikolaos; Pantidis, Dimitrios; Dedes, Athansios; Daskalakis, Nikolaos; Ioannou, Christos V.

    2016-01-01

    Abdominal aortic aneurysms (AAAs) represent a focal dilation of the aorta exceeding 1.5 times its normal diameter. It is reported that 4–8% of men and 0.5–1% of women above 50 years of age bear an AAA. Rupture represents the most disastrous complication of aneurysmal disease that is accompanied by an overall mortality of 80%. Autopsy data have shown that nearly 13% of AAAs with a maximum diameter ≤5 cm were ruptured and 60% of the AAAs >5 cm in diameter never ruptured. It is therefore obvious that the “maximum diameter criterion,” as a single parameter that fits all patients, is obsolete. Investigators have begun a search for more reliable rupture risk markers for AAA expansion, such as the level and change of peak wall stress or AAA geometry. Furthermore, it is becoming more and more evident that intraluminal thrombus (ILT), which is present in 75% of all AAAs, affects AAA features and promotes their expansion. Though these hemodynamic properties of AAAs are significant and seem to better describe rupture risk, they are in need of specialized equipment and software and demand time for processing making them difficult in use and unattractive to clinicians in everyday practice. In the search for the addition of other risk factors or user-friendly tools, which may predict AAA expansion and rupture, the use of the asymmetrical ILT deposition index seems appealing since it has been reported to identify AAAs that may have an increased or decreased growth rate. PMID:26835458

  14. Rupture models with dynamically determined breakdown displacement

    USGS Publications Warehouse

    Andrews, D.J.

    2004-01-01

    The critical breakdown displacement, Dc, in which friction drops to its sliding value, can be made dependent on event size by specifying friction to be a function of variables other than slip. Two such friction laws are examined here. The first is designed to achieve accuracy and smoothness in discrete numerical calculations. Consistent resolution throughout an evolving rupture is achieved by specifying friction as a function of elapsed time after peak stress is reached. Such a time-weakening model produces Dc and fracture energy proportional to the square root of distance rupture has propagated in the case of uniform stress drop. The second friction law is more physically motivated. Energy loss in a damage zone outside the slip zone has the effect of increasing Dc and limiting peak slip velocity (Andrews, 1976). This article demonstrates a converse effect, that artificially limiting slip velocity on a fault in an elastic medium has a toughening effect, increasing fracture energy and Dc proportionally to rupture propagation distance in the case of uniform stress drop. Both the time-weakening and the velocity-toughening models can be used in calculations with heterogeneous stress drop.

  15. Isolated unilateral rupture of the alar ligament.

    PubMed

    Wong, Sui-To; Ernest, Kimberly; Fan, Grace; Zovickian, John; Pang, Dachling

    2014-05-01

    Only 6 cases of isolated unilateral rupture of the alar ligament have been previously reported. The authors report a new case and review the literature, morbid anatomy, and pathogenesis of this rare injury. The patient in their case, a 9-year-old girl, fell head first from a height of 5 feet off the ground. She presented with neck pain, a leftward head tilt, and severe limitation of right rotation, extension, and right lateral flexion of the neck. Plain radiographs and CT revealed no fracture but a shift of the dens toward the right lateral mass of C-1. Magnetic resonance imaging of the cervical spine showed signal hyperintensity within the left dens-atlas space on both T1- and T2-weighted sequences and interruption of the expected dark signal representing the left alar ligament, suggestive of its rupture. After 12 weeks of immobilization in a Guilford brace, MRI showed lessened dens deviation, and the patient attained full and painless neck motion. Including the patient in this case, the 7 patients with this injury were between 5 and 21 years old, sustained the injury in traffic accidents or falls, presented with marked neck pain, and were treated with external immobilization. All patients had good clinical outcome. The mechanism of injury is hyperflexion with rotation. Isolated unilateral alar ligament rupture is a diagnosis made by excluding associated fracture, dislocation, or disruption of other major ligamentous structures in the craniovertebral junction. CT and MRI are essential in establishing the diagnosis. External immobilization is adequate treatment.

  16. Dynamics of retinal photocoagulation and rupture

    NASA Astrophysics Data System (ADS)

    Sramek, Christopher; Paulus, Yannis; Nomoto, Hiroyuki; Huie, Phil; Brown, Jefferson; Palanker, Daniel

    2009-05-01

    In laser retinal photocoagulation, short (<20 ms) pulses have been found to reduce thermal damage to the inner retina, decrease treatment time, and minimize pain. However, the safe therapeutic window (defined as the ratio of power for producing a rupture to that of mild coagulation) decreases with shorter exposures. To quantify the extent of retinal heating and maximize the therapeutic window, a computational model of millisecond retinal photocoagulation and rupture was developed. Optical attenuation of 532-nm laser light in ocular tissues was measured, including retinal pigment epithelial (RPE) pigmentation and cell-size variability. Threshold powers for vaporization and RPE damage were measured with pulse durations ranging from 1 to 200 ms. A finite element model of retinal heating inferred that vaporization (rupture) takes place at 180-190°C. RPE damage was accurately described by the Arrhenius model with activation energy of 340 kJ/mol. Computed photocoagulation lesion width increased logarithmically with pulse duration, in agreement with histological findings. The model will allow for the optimization of beam parameters to increase the width of the therapeutic window for short exposures.

  17. [Traumatic rupture of the thoracic aorta].

    PubMed

    Glock, Y; Roux, D; Soula, P; Cerene, A; Fournial, G

    1996-01-01

    This is a retrospective analysis of 50 postraumatic aortic rupture (1968-1996, 39 males, mean age: 34.5). Group A is composed of 35 patients with an acute aortic rupture and a prompt diagnosis. Group B includes 13 patients with a chronic rupture. All patients from group A had a severe politraumatism with abdominal, cranial, extremities or hip fractures. Mediastinal thickening with or without hemothorax indicated an angiography or a transesophageal echocardiography lately. In group A, 36 patients have been operated on urgently (12-24 hours); cardiopulmonary bypass was performed on 20 patients; an aorto-aortical bypass was done in 27 cases and a direct suture in the remaining 9. In group B, cardiopulmonary bypass was performed on 9 patients; a aorto-aortical bypass was done in 11 cases and a direct suture in 2. Overall hospital mortality was 16%; 19% in group A and 7.6% in group B. Ischemic paraplejia appeared in 5 patients (10%), all from group A. No false aneurysm developed after 4.5 years of follow-up (3-135 months) in the 38 survivors. The usefulness of transesophageal echocardiography, the importance of medular protection and the utility of several interventionist radiologic techniques are discussed. PMID:9053930

  18. Isolated medial head of triceps rupture

    PubMed Central

    Marappa Ganeshan, Raghavendra; Keerthi, Naveen

    2014-01-01

    Triceps ruptures are less common injuries presenting to the orthopaedic or emergency department setting compared with other musculoskeletal injuries. This to some extent reduces the level of index of suspicion or chances of considering the triceps rupture as one of the differential diagnosis while examining a patient following upper limb injury. The literature search shows that a significant proportion of patient diagnosis has been missed during initial presentation, leading to a delay in diagnosis and in providing definitive treatment, ranging from 6 to 18 months. The triceps are the primary extensor of the elbow and are supplied with the radial nerve. Any injury to the triceps can adversely affect the functioning of the limb and influence the ability to work and return to employment. We share our experience of treating a patient with a triceps rupture, in whom the diagnosis was made 6 months after injury; the patient was able to return to manual work 3 months after surgical repair. PMID:25362186

  19. Single Event Gate Rupture in EMCCD technology

    NASA Astrophysics Data System (ADS)

    Evagora, A. M.; Murray, N. J.; Holland, A. D.; Burt, D.

    2012-12-01

    The high electric fields (typically 3 MV/cm2 interpoly field) utilised in Electron Multiplying Charged Coupled Devices (EMCCDs) reveal a potential vulnerability from Single Event Phenomena (SEP), in particular Single Event Gate Rupture (SEGR). SEGR is where a conduction path between two conductive areas of the CCD is produced, causing device failure. If EMCCDs are to be used for space applications the susceptibility to these events needs to be explored. A positive result from such an investigation can increase the technology readiness level of the device moving it another step closer to being used in space. Testing undertaken at the CYClotron of LOuvain la NEuve (CYCLONE), using the Heavy Ion Facility (HIF), conclusively showed EMCCD technology to have resilience to heavy ions that surpassed initial expectations. The simulations undertaken prior to experiment suggested gate rupture would occur at 20-40 MeV cm2/mg, however Linear Energy Transfers (LETs) greater than 100 MeV cm2/mg proved to not cause a rupture event. Within the radiation belts heavy ions with an LET greater than 60 MeV cm2/mg are not very common when compared to the fluxes used at the HIF. Possible reasons for this result are discussed in this work, leading to a conclusion that EMCCD technology is a secure choice for space flight.

  20. Carotid artery rupture and cervicofacial actinomycosis.

    PubMed

    Kummer, Anne; Lhermitte, Benoît; Ödman, Micaela; Grabherr, Silke; Mangin, Patrice; Palmiere, Cristian

    2012-11-01

    Cervicofacial actinomycosis is an uncommon, progressive infection caused by bacilli of the Actinomyces genus. Actinomyces are common commensal saprophytes in the oral cavity which may have medical importance as facultative pathogens. Subsequent to local injuries to the oral mucosa, they may penetrate the deep tissues and be responsible for suppurative or granulomatous infections. We herein report a case of a 65-year-old man who underwent surgery followed by chemotherapy and radiotherapy for a tonsillar carcinoma. An ulcerous lesion in the base of the tongue developed and spread to the carotid artery wall. The man died of a massive hemorrhage due to left carotid artery rupture. Postmortem computed tomography angiography performed prior to autopsy allowed the precise localization of the source of bleeding to be detected. Postmortem biochemical investigations confirmed the presence of inflammation associated with local bacterial infection. Histological investigations revealed the rupture of the left carotid artery surrounded by numerous colonies of Actinomyces. Acute and chronic inflammation with tissue necrosis as well as post-actinic, fibrotic changes were also found in the tissues surrounding the ruptured artery wall. PMID:22819527

  1. Simultaneous reconstruction of quadriceps tendon rupture after TKA and neglected Achilles tendon rupture.

    PubMed

    Lee, Yong Seuk; Min, Byoung-Hyun; Han, Kyeong-Jin; Cho, Jae Ho; Han, Seung Hwan; Lee, Doo-Hyung; Oh, Kyung Soo

    2010-05-12

    We report a case of simultaneous reconstruction of a quadriceps tendon rupture after total knee arthroplasty (TKA) and neglected Achilles tendon rupture, which occurred before TKA with an ipsilateral hamstring autograft. A 64-year-old woman presented with persistent right knee pain. She also had right heel pain and had received multiple steroid injections at the knee joint and heel. On examination, she showed osteoarthritis in the medial and lateral compartments of the knee joint and an Achilles tendon rupture in the ipsilateral limb. There was skin dimpling and the proximal portion of tendon was migrated. We performed TKA, and the postoperative course was satisfactory. She returned 3 months postoperatively, however, with skin dimpling around the suprapatellar area and weakness of knee extension. Her ankle symptoms were also aggravated because she could not use the knee joint freely. We performed simultaneous reconstruction of the quadriceps tendon and the Achilles tendon using an ipsilateral hamstring autograft.Hamstring autograft offers a good alternative treatment option for rupture repair, particularly with concommitant ruptures of multiple sites when primary repair is not possible or the viability of repaired tissue is poor.

  2. Liver Hydatid Cyst with Transdiaphragmatic Rupture and Lung Hydatid Cyst Ruptured into Bronchi and Pleural Space

    SciTech Connect

    Ar Latin-Small-Letter-Dotless-I bas, Bilgin Kadri Dingil, Guerbuez; Koeroglu, Mert; Uenguel, Uemit; Zaral Latin-Small-Letter-Dotless-I , Aliye Ceylan

    2011-02-15

    The aim of this case study is to present effectiveness of percutaneous drainage as a treatment option of ruptured lung and liver hydatid cysts. A 65-year-old male patient was admitted with complicated liver and lung hydatid cysts. A liver hydatid cyst had ruptured transdiaphragmatically, and a lung hydatid cyst had ruptured both into bronchi and pleural space. The patient could not undergo surgery because of decreased respiratory function. Both cysts were drained percutaneously using oral albendazole. Povidone-iodine was used to treat the liver cyst after closure of the diaphragmatic rupture. The drainage was considered successful, and the patient had no recurrence of signs and symptoms. Clinical, laboratory, and radiologic recovery was observed during 2.5 months of catheterization. The patient was asymptomatic after catheter drainage. No recurrence was detected during 86 months of follow-up. For inoperable patients with ruptured liver and lung hydatid cysts, percutaneous drainage with oral albendazole is an alternative treatment option to surgery. The percutaneous approach can be life-saving in such cases.

  3. Risk.

    PubMed

    Cole, Stephen R; Hudgens, Michael G; Brookhart, M Alan; Westreich, Daniel

    2015-02-15

    The epidemiologist primarily studies transitions between states of health and disease. The purpose of the present article is to define a foundational parameter for such studies, namely risk. We begin simply and build to the setting in which there is more than 1 event type (i.e., competing risks or competing events), as well as more than 1 treatment or exposure level of interest. In the presence of competing events, the risks are a set of counterfactual cumulative incidence functions for each treatment. These risks can be depicted visually and summarized numerically. We use an example from the study of human immunodeficiency virus to illustrate concepts. PMID:25660080

  4. Rupture of internal pudendal artery aneurysm following spontaneous vaginal delivery: An uncommon cause of post-partum bleeding.

    PubMed

    Martingano, Daniel; Martingano, Francis X; Ruggiero-DeCarlo, Rosemary

    2016-09-01

    Pregnancy-related rupture of an arterial aneurysm is an unusual occurrence associated with increased risk of morbidity and mortality. Various pregnancy-related physiologic changes appear to make pregnancy a high-risk situation for rupture of either preexisting arterial aneurysms or those that develop throughout the course of pregnancy. Splenic artery aneurysms are the most common (60%), followed by hepatic (20%), superior mesenteric (5.9%), celiac (4%), ovarian, uterine, and renal (<2%) artery. Even rarer are aneurysms involving the internal iliac artery and its branches, to which there is only one published case report. In this report, we present a case of a 34-year-old pregnant gravida1 para0 who, following a normal vaginal delivery, had a severe rupture of the right internal pudendal artery and subsequently developed a massive hematoma which ultimately required embolization treatment. PMID:27630752

  5. The AAA+ proteins Pontin and Reptin enter adult age: from understanding their basic biology to the identification of selective inhibitors.

    PubMed

    Matias, Pedro M; Baek, Sung Hee; Bandeiras, Tiago M; Dutta, Anindya; Houry, Walid A; Llorca, Oscar; Rosenbaum, Jean

    2015-01-01

    Pontin and Reptin are related partner proteins belonging to the AAA+ (ATPases Associated with various cellular Activities) family. They are implicated in multiple and seemingly unrelated processes encompassing the regulation of gene transcription, the remodeling of chromatin, DNA damage sensing and repair, and the assembly of protein and ribonucleoprotein complexes, among others. The 2nd International Workshop on Pontin and Reptin took place at the Instituto de Tecnologia Química e Biológica António Xavier in Oeiras, Portugal on October 10-12, 2014, and reported significant new advances on the mechanisms of action of these two AAA+ ATPases. The major points under discussion were related to the mechanisms through which these proteins regulate gene transcription, their roles as co-chaperones, and their involvement in pathophysiology, especially in cancer and ciliary biology and disease. Finally, they may become anticancer drug targets since small chemical inhibitors were shown to produce anti-tumor effects in animal models.

  6. The AAA+ ATPase ATAD3A Controls Mitochondrial Dynamics at the Interface of the Inner and Outer Membranes ▿

    PubMed Central

    Gilquin, Benoît; Taillebourg, Emmanuel; Cherradi, Nadia; Hubstenberger, Arnaud; Gay, Olivia; Merle, Nicolas; Assard, Nicole; Fauvarque, Marie-Odile; Tomohiro, Shiho; Kuge, Osamu; Baudier, Jacques

    2010-01-01

    Dynamic interactions between components of the outer (OM) and inner (IM) membranes control a number of critical mitochondrial functions such as channeling of metabolites and coordinated fission and fusion. We identify here the mitochondrial AAA+ ATPase protein ATAD3A specific to multicellular eukaryotes as a participant in these interactions. The N-terminal domain interacts with the OM. A central transmembrane segment (TMS) anchors the protein in the IM and positions the C-terminal AAA+ ATPase domain in the matrix. Invalidation studies in Drosophila and in a human steroidogenic cell line showed that ATAD3A is required for normal cell growth and cholesterol channeling at contact sites. Using dominant-negative mutants, including a defective ATP-binding mutant and a truncated 50-amino-acid N-terminus mutant, we showed that ATAD3A regulates dynamic interactions between the mitochondrial OM and IM sensed by the cell fission machinery. The capacity of ATAD3A to impact essential mitochondrial functions and organization suggests that it possesses unique properties in regulating mitochondrial dynamics and cellular functions in multicellular organisms. PMID:20154147

  7. Unfolding the mechanism of the AAA+ unfoldase VAT by a combined cryo-EM, solution NMR study.

    PubMed

    Huang, Rui; Ripstein, Zev A; Augustyniak, Rafal; Lazniewski, Michal; Ginalski, Krzysztof; Kay, Lewis E; Rubinstein, John L

    2016-07-19

    The AAA+ (ATPases associated with a variety of cellular activities) enzymes play critical roles in a variety of homeostatic processes in all kingdoms of life. Valosin-containing protein-like ATPase of Thermoplasma acidophilum (VAT), the archaeal homolog of the ubiquitous AAA+ protein Cdc48/p97, functions in concert with the 20S proteasome by unfolding substrates and passing them on for degradation. Here, we present electron cryomicroscopy (cryo-EM) maps showing that VAT undergoes large conformational rearrangements during its ATP hydrolysis cycle that differ dramatically from the conformational states observed for Cdc48/p97. We validate key features of the model with biochemical and solution methyl-transverse relaxation optimized spectroscopY (TROSY) NMR experiments and suggest a mechanism for coupling the energy of nucleotide hydrolysis to substrate unfolding. These findings illustrate the unique complementarity between cryo-EM and solution NMR for studies of molecular machines, showing that the structural properties of VAT, as well as the population distributions of conformers, are similar in the frozen specimens used for cryo-EM and in the solution phase where NMR spectra are recorded.

  8. Acute Ultrasonography Investigation to Predict Reruptures and Outcomes in Patients With an Achilles Tendon Rupture

    PubMed Central

    Westin, Olof; Nilsson Helander, Katarina; Grävare Silbernagel, Karin; Möller, Michael; Kälebo, Peter; Karlsson, Jón

    2016-01-01

    Background: The optimal treatment for acute Achilles tendon ruptures is still an ongoing debate. Acute ultrasonography (US) investigation to measure the diastasis between the tendon ends has previously been used to classify acute Achilles tendon ruptures; however, no study has used US to predict reruptures and functional outcomes. Purpose: To investigate whether acute US can be used to predict the risk of reruptures and outcomes after treatment of an acute Achilles tendon rupture. Study Design: Cohort study; Level of evidence, 2. Methods: Forty-five patients (37 men, 8 women) with a mean age of 39 ± 9.2 years (range, 23-59 years) from a cohort of 97 patients participating in a randomized controlled study comparing surgical and nonsurgical treatment were included. US was performed within 72 hours from the index injury. Diastasis between the tendon ends was documented. Reruptures were documented, and the patients’ functional outcomes were measured 12 months after injury. Results: Patients with a diastasis of >10 mm treated nonsurgically had a higher degree of rerupture. In the nonsurgically treated group, 3 of 4 patients with a diastasis of >10 mm suffered from rerupture (P < .001). Moreover, in the nonsurgical group, there was significantly worse outcomes in patients with a diastasis of >5 mm in terms of patient-reported outcomes using the Achilles tendon Total Rupture Score (ATRS) (P = .004) and heel-rise height at 12 months (P = .048) compared with the group with a lesser degree of tendon separation. Conclusion: US may be a useful tool to predict the risk of rerupture and greater degree of functional deficit. It may be an important measure in a clinical treatment algorithm for deciding whether a patient will benefit from surgical intervention after an acute Achilles tendon rupture. PMID:27781212

  9. Spontaneous subarachnoid hemorrhage due to ruptured cavernous internal carotid artery aneurysm after medical prolactinoma treatment.

    PubMed

    Khalsa, Siri Sahib; Hollon, Todd C; Shastri, Ravi; Trobe, Jonathan D; Gemmete, Joseph J; Pandey, Aditya S

    2016-01-01

    Aneurysms of the cavernous segment of the internal carotid artery (ICA) are believed to have a low risk of subarachnoid haemorrhage (SAH), given the confines of the dural rings and the anterior clinoid process. The risk may be greater when the bony and dural protection has been eroded. We report a case of spontaneous SAH from rupture of a cavernous ICA aneurysm in a patient whose large prolactinoma had markedly decreased in size as the result of cabergoline treatment. After passing a balloon test occlusion, the patient underwent successful endovascular vessel deconstruction. This case suggests that an eroding skull base lesion may distort normal anterior cranial base anatomy and allow communication between the cavernous ICA and subarachnoid space. The potential for SAH due to cavernous ICA aneurysm rupture should be recognised in patients with previous pituitary or other skull base lesions adjacent to the cavernous sinus. PMID:27277584

  10. Coupling geodynamic earthquake cycles and dynamic ruptures

    NASA Astrophysics Data System (ADS)

    van Zelst, Iris; van Dinther, Ylona; Gabriel, Alice-Agnes; Heuret, Arnauld

    2016-04-01

    Studying the seismicity in a subduction zone and its effects on tsunamis requires diverse modelling methods that span spatial and temporal scales. Hundreds of years are necessary to build the stresses and strengths on a fault, while consequent earthquake rupture propagation is determined by both these initial fault conditions and the feedback of seismic waves over periods of seconds up to minutes. This dynamic rupture displaces the sea floor, thereby causing tsunamis. The aim of the ASCETE (Advanced Simulations of Coupled Earthquake and Tsunami Events) project is to study all these aspects and their interactions. Here, we present preliminary results of the first aspects in this modelling chain: the coupling of a seismo-thermo-mechanical (STM) code to the dynamic rupture model SeisSol. STM models of earthquake cycles have the advantage of solving multiple earthquake events in a self-consistent manner concerning stress, strength and geometry. However, the drawback of these models is that they often lack in spatial or temporal resolution and do not include wave propagation. In contrast, dynamic rupture models solve for frictional failure coupled to seismic wave propagation. We use the software package SeisSol (www.seissol.org) based on an ADER-DG discretization allowing high-order accuracy in space and time as well as flexible tetrahedral meshing. However, such simulations require assumptions on the initial fault stresses and strengths and its geometry, which are hard to constrain due to the lack of near-field observations and the complexity of coseismic conditions. By adapting the geometry as well as the stress and strength properties of the self-consistently developing non-finite fault zones from the geodynamic models as initial conditions for the dynamic rupture models, the advantages of both methods are exploited and modelling results may be compared. Our results show that a dynamic rupture can be triggered spontaneously and that the propagating rupture is

  11. Treatment of a Ruptured Vertebrobasilar Fusiform Aneurysm Using Pipeline Embolization Device

    PubMed Central

    Tan, Lee A.; Lopes, Demetrius K.

    2013-01-01

    Treatment options of ruptured vertebrobasilar fusiform aneurysms (VFA) are limited and often carry significant mortality and morbidity. We report the use of Pipeline Embolization Device (PED) to successfully treat a patient with a ruptured vertebrobasilar fusiform aneurysm (VFA) who presented with subarachnoid hemorrhage (SAH). A 73 year-old man with a history of cardiac stent placement seven days earlier presented with Hunt-Hess II SAH. He was taking aspirin and clopidogrel. Computed tomography angiogram revealed a large vertebrobasilar fusiform aneurysm. Microsurgical treatment options are technically challenging and carry high risk. He underwent endovascular treatment of the ruptured VFA using overlapping PEDs. Five PEDs were placed in a telescoping fashion to reconstruct the affected portions of the left vertebral and basilar arteries. An additional 2-mm blister aneurysm in the right vertebral artery was also discovered during the conventional cerebral angiography and was treated with one additional PED. The patient remained neurologically intact after the procedure. He was continued on aspirin and clopidogrel. Follow-up magnetic resonance imaging at three months demonstrated patency of the stents without any evidence of ischemic change. Follow-up conventional cerebral angiogram at six months demonstrated thrombosis of the VFA and reconstruction of the vertebrobasilar system. The patient remained clinically well. An endovascular approach using PEDs can be a safe and effective treatment option for ruptured VFA in selected cases. PMID:23593603

  12. [Quadriceps tendon insufficiency and rupture : Treatment options in total knee arthroplasty].

    PubMed

    Thiele, K; von Roth, P; Pfitzner, T; Preininger, B; Perka, C

    2016-05-01

    Quadriceps tendon injuries and insufficiencies in total knee arthroplasty are rare, but are followed by a devastating complication that left untreated leads to a complete loss of function of the knee. This review article summarizes the functional anatomy, risk factors, and the prevalence and diagnosis of quadriceps tendon injuries, in addition to the possible management options for partial and complete ruptures. The treatment options are adapted according to the extent of the loss of function (partial, complete) and the duration of the injury (acute vs chronic). Furthermore, the choice of treatment should take into account the quality and availability of primary tissue, the patient's general health, along with their likely functional requirements. Conservative treatment is often justified in partial ruptures with good results. Complete ruptures require surgical intervention and multiple operative techniques are described. Treatment options for acute ruptures include direct primary repair with autogenous or synthetic tissue augmentation. In the case of chronic insufficiency and a lack of soft-tissue surroundings, reconstruction with the aid of a muscle flap or allograft tissue can be considered. All surgical intervention techniques used so far have been fraught with complications and rarely lead to satisfactory results. A new surgical approach to the reconstruction and augmentation of the extensor mechanism consists of the use of a synthetic mesh. The technique is described here in detail.

  13. Sequential rupture of triceps and quadriceps tendons in a dialysis patient using hormone supplements.

    PubMed

    Soo, I; Christiansen, J; Marion, D; Courtney, M; Luyckx, V A

    2011-02-01

    Spontaneous rupture of tendons is rare, and typically occurs in large weight bearing tendons such as the quadriceps, Achilles and patellar tendon, in the context of various chronic diseases including end-stage renal disease. In general, tendon rupture in dialysis patients is associated with hyperparathyroidism, long duration of dialysis, steroid and quinolone use. We present a case of a young man on chronic dialysis who presented with sequential rupture of triceps and quadriceps tendons requiring surgical repair, several months after initiating use of multiple hormone supplements including human growth hormone and androgens. The supplements were obtained over the internet with the aim of improving his kidney function. Although this patient did have hyperparathyroidism, it is likely his PTH elevation was exacerbated by use of human growth hormone, and tendon rupture risk increased by concurrent use of an androgen supplement. This case highlights the fact that dialysis patients do utilize alternative remedies and that there may be unexpected, dialysis-specific complications associated with their use.

  14. [Prediction of maternofetal infection in preterm premature rupture of membranes: serum maternal markers].

    PubMed

    Popowski, T; Goffinet, F; Batteux, F; Maillard, F; Kayem, G

    2011-05-01

    Premature rupture of membranes is a common situation in obstetrics that links the amniotic cavity and the bacterial cervicovaginal flora. The main risk in case of preterm premature rupture of membranes is the occurrence of an amniochorial infection, which increases neonatal morbidity and mortality. One main purpose in cases of preterm premature rupture of membranes is to identify infection early to adapt the clinical care. Among the marker used in practice, CRP has a sensitivity between 56% and 86% and specificity between 55% and 82% for predicting clinical chorioamnionitis. These values are respectively 21% to 56% and 76% to 95% for the prediction of early neonatal infection. The white blood cell count, also used in routine, has a poor predictive value of clinical chorioamnionitis although a high specificity when the threshold is of 16 giga/l. Among the pro-inflammatory cytokines, interleukin-6 has been the most studied. Its predictive value for chorioamnionitis or neonatal infection is higher but its clinical usefulness is limited by the various threshold used in the studies and the lack of routine measure. Procalcitonin appears to have low predictive values for detecting amniochorial infection but has finally been little studied. Ways to improve prediction of infection in cases of premature rupture of membranes are either looking for new markers or the analysis of local markers (vaginal secretions and amniotic fluid).

  15. Optical coherence tomography: a potential tool to predict premature rupture of fetal membranes.

    PubMed

    Micili, Serap C; Valter, Markus; Oflaz, Hakan; Ozogul, Candan; Linder, Peter; Föckler, Nicole; Artmann, Gerhard M; Digel, Ilya; Artmann, Aysegul T

    2013-04-01

    A fundamental question addressed in this study was the feasibility of preterm birth prediction based on a noncontact investigation of fetal membranes in situ. Although the phenomena of preterm birth and the premature rupture of the fetal membrane are well known, currently, there are no diagnostic tools for their prediction. The aim of this study was to assess whether optical coherence tomography could be used for clinical investigations of high-risk pregnancies. The thickness of fetal membranes was measured in parallel by optical coherence tomography and histological techniques for the following types of birth: normal births, preterm births without premature ruptures and births at full term with premature rupture of membrane. Our study revealed that the membrane thickness correlates with the birth type. Normal births membranes were statistically significantly thicker than those belonging to the other two groups. Thus, in spite of almost equal duration of gestation of the normal births and the births at full term with premature rupture, the corresponding membrane thicknesses differed. This difference is possibly related to previously reported water accumulation in the membranes. The optical coherence tomography results were encouraging, suggesting that this technology could be used in future to predict and distinguish between different kinds of births.

  16. Risk

    NASA Technical Reports Server (NTRS)

    Barshi, Immanuel

    2016-01-01

    Speaking up, i.e. expressing ones concerns, is a critical piece of effective communication. Yet, we see many situations in which crew members have concerns and still remain silent. Why would that be the case? And how can we assess the risks of speaking up vs. the risks of keeping silent? And once we do make up our minds to speak up, how should we go about it? Our workshop aims to answer these questions, and to provide us all with practical tools for effective risk assessment and effective speaking-up strategies..

  17. Stent-graft repair for acute traumatic thoracic aortic rupture.

    PubMed

    Neuhauser, B; Czermak, B; Jaschke, W; Waldenberger, P; Fraedrich, G; Perkmann, R

    2004-12-01

    Traumatic rupture of the thoracic aorta is potentially life-threatening and leads to death in 75 to 90 per cent of cases at the time of injury. In high-risk patients, as traumatic injuries of the aorta combine with multiple associated injuries, endoluminal repair is now reported as a promising therapeutic strategy with encouraging results. This study determined the outcome of patients with traumatic thoracic aortic injury treated endovascularly during the past 7 years at our institution. Thirteen patients, 11 males and 2 females (mean age, 39 years; range, 19-82), with traumatic rupture of the otherwise unremarkable descending aorta (10 acute, 3 chronic), out of a series of 64 endovascular thoracic stent-graft procedures, were treated by implantation of Talent (n = 8), Vanguard (n = 5), and Excluder (n = 2) self-expanding devices between January 1996 and August 2003. The immediate technical success rate was 92 per cent (12/13). One patient showed a proximal endoleak type I, which was treated successfully by an additional stent-graft procedure. Secondary success rate was 100 per cent. The mortality rate was 0 per cent. Two additional stent-graft procedures were performed due to type I endoleaks after 18 and 28 months. There was no other intervention-related morbidity or mortality during the mean follow-up time of 26.4 months' (range, 6-86). Endovascular stent-graft repair of traumatic thoracic aortic injuries is a safe, effective, and low-morbidity alternative to open thoracic surgery and has promising midterm results.

  18. Exposure to Ambient Air Pollution and Premature Rupture of Membranes.

    PubMed

    Wallace, Maeve E; Grantz, Katherine L; Liu, Danping; Zhu, Yeyi; Kim, Sung Soo; Mendola, Pauline

    2016-06-15

    Premature rupture of membranes (PROM) is a major factor that predisposes women to preterm delivery. Results from previous studies have suggested that there are associations between exposure to air pollution and preterm birth, but evidence of a relationship with PROM is sparse. Modified Community Multiscale Air Quality models were used to estimate mean exposures to particulate matter less than 10 µm or less than 2.5 µm in aerodynamic diameter, nitrogen oxides, carbon monoxide, sulfur dioxide, and ozone among 223,375 singleton deliveries in the Air Quality and Reproductive Health Study (2002-2008). We used log-linear models with generalized estimating equations to estimate adjusted relative risks and 95% confidence intervals for PROM per each interquartile-range increase in pollutants across the whole pregnancy, on the day of delivery, and 5 hours before delivery. Whole-pregnancy exposures to carbon monoxide and sulfur dioxide were associated with an increased risk of PROM (for carbon monoxide, relative risk (RR) = 1.09, 95% confidence interval (CI): 1.04, 1.14; for sulfur dioxide, RR = 1.15, 95% CI: 1.06, 1.25) but not preterm PROM. Ozone exposure increased the risk of PROM on the day of delivery (RR = 1.06, 95% CI: 1.02, 1.09) and 1 day prior (RR = 1.04, 95% CI: 1.01, 1.07). In the 5 hours preceding delivery, there were 3%-7% increases in risk associated with exposure to ozone and particulate matter less than 2.5 µm in aerodynamic diameter and inverse associations with exposure to carbon monoxide and nitrogen oxides. Acute and long-term air pollutant exposures merit further study in relation to PROM. PMID:27188941

  19. [SURGICAL TREATMENT OF PATIENTS WITH URETERAL RUPTURES].

    PubMed

    Komjakov, B K; Guliev, B G

    2015-01-01

    The aim of the study was to analyze the causes of ureteral ruptures and the types surgical procedures used for their management. Over the period from 2006 to 2014, 7 patients with ureteral ruptures underwent surgical treatment in the Mechnikov N-WSMU clinic. All of them were males aged 50 to 71 years. In all cases, the ureter was injured during ureteroscopy and contact lithotripsy. In two patients the right ureter was cut off at the border of the upper and middle third, in four--at 3-4 cm below pyeloureteral segment, one patient diagnosed with a complete separation of the ureter from the kidney pelvis. Patients, who have suffered a detachment of the ureter in other hospitals, previously underwent surgical exploration of the retroperitoneal space, drainage of the kidney by pyelonephrostomy (5) and ureterocutaneostomy (1). In a case of a patient with an injury that occurred in our clinic, laparoscopic nephrectomy with autologous renal transplantation was carried out. Five patients with extended ureter defects underwent ileo-ureteroplasty. The patient with left ureterocutaneostomy underwent nephrovesical bypass. Patency of the upper urinary tract and kidney function were restored in all patients, all of them were relieved from external drains. The duration of the intestinal plastic averaged 160 minutes, laparoscopic nephrectomy with autologous transplantation--210 min and nephrovesical bypass--110 min. Blood transfusion was required only in autologous graft patient. The ureteral rupture is a serious complication of ureteral endourological procedures in upper urinary tract. It requires such complicated reconstructive operations as autologous transplantation of the kidney or intestinal ureteroplasty. PMID:26390553

  20. Dynamic stress changes during earthquake rupture

    USGS Publications Warehouse

    Day, S.M.; Yu, G.; Wald, D.J.

    1998-01-01

    We assess two competing dynamic interpretations that have been proposed for the short slip durations characteristic of kinematic earthquake models derived by inversion of earthquake waveform and geodetic data. The first interpretation would require a fault constitutive relationship in which rapid dynamic restrengthening of the fault surface occurs after passage of the rupture front, a hypothesized mechanical behavior that has been referred to as "self-healing." The second interpretation would require sufficient spatial heterogeneity of stress drop to permit rapid equilibration of elastic stresses with the residual dynamic friction level, a condition we refer to as "geometrical constraint." These interpretations imply contrasting predictions for the time dependence of the fault-plane shear stresses. We compare these predictions with dynamic shear stress changes for the 1992 Landers (M 7.3), 1994 Northridge (M 6.7), and 1995 Kobe (M 6.9) earthquakes. Stress changes are computed from kinematic slip models of these earthquakes, using a finite-difference method. For each event, static stress drop is highly variable spatially, with high stress-drop patches embedded in a background of low, and largely negative, stress drop. The time histories of stress change show predominantly monotonic stress change after passage of the rupture front, settling to a residual level, without significant evidence for dynamic restrengthening. The stress change at the rupture front is usually gradual rather than abrupt, probably reflecting the limited resolution inherent in the underlying kinematic inversions. On the basis of this analysis, as well as recent similar results obtained independently for the Kobe and Morgan Hill earthquakes, we conclude that, at the present time, the self-healing hypothesis is unnecessary to explain earthquake kinematics.

  1. Surgical repair of a rupture of the pectoralis major muscle.

    PubMed

    Pochini, Alberto De Castro; Andreoli, Carlos Vicente; Ejnisman, Benno; Maffulli, Nicola

    2015-02-25

    Muscle rupture is rarely treated surgically. Few reports of good outcomes after muscular suture have been published. Usually, muscular lesions or partial ruptures heal with few side effects or result in total recovery. We report a case of an athlete who was treated surgically to repair a total muscular rupture in the pectoralis major muscle. After 6 months, the athlete returned to competitive practice. After a 2-year follow-up, the athlete still competes in skateboard championships.

  2. Uterine rupture following termination of pregnancy in a scarred uterus.

    PubMed

    Bika, O; Huned, D; Jha, S; Selby, K

    2014-02-01

    We present a series of two cases complicated by uterine rupture following termination of pregnancy (TOP) in the 1st and 2nd trimesters using misoprostol in women with caesarean section scar. Current literature and practise have also been reviewed on ruptured uterus in women with caesarean section scar undergoing TOP using misoprostol; the diagnosis of adherent placenta in the 1st and 2nd trimesters in women with previous caesarean uterine scar; and likely implications of a ruptured uterus.

  3. [Bilateral uterine rupture of an unscarred gravid uterus before labor].

    PubMed

    Leroux, M; Coatleven, F; Faure, M; Horovitz, J

    2014-06-01

    We report a case of bilateral spontaneous uterine rupture of an unscarred uterus occured in a primigravida at 32 weeks to take care in our department after in utero transfert. Uterine rupture occurs mainly on scarred uterus during labor. This is an unfrequent but serious complication involving fetal-maternal prognosis in the absence of immediate care. We are conducting a review about spontaneous uterine rupture of unscarred uterus, before and during labor.

  4. [Spontaneous rupture of the unscarred uterus during labor. Case report].

    PubMed

    Leung, F; Courtois, L; Aouar, Z; Bourtembourg, A; Eckman, A; Terzibachian, J J; Maillet, R; Riethmuller, D

    2009-04-01

    We report a case of spontaneous uterine rupture in a 19 year-old patient Gravida 1 para 2 with no past history of uterine surgery. The diagnosis of uterine rupture, evoked in the early post-partum in the presence of acute abdominal pain, collapsus and haemoperitoneum on ultrasonography, was confirmed by laparotomy. Treatment consisted in hysterorrhaphy. The etiopathogenesis, clinical and therapeutical aspects of spontaneous unscarred uterine ruptures are discussed throughout a literature review.

  5. SU-E-T-137: Dosimetric Validation for Pinnacle, Acuros, AAA, and Brainlab Algorithms with Induced Inhomogenieties

    SciTech Connect

    Lopez, P; Tambasco, M; LaFontaine, R; Burns, L

    2014-06-01

    Purpose: To compare the dosimetric accuracy of the Eclipse 11.0 Acuros XB and Anisotropic Analytical Algorithm (AAA), Pinnacle-3 9.2 Collapsed Cone Convolution, and the iPlan 4.1 Monte Carlo (MC) and Pencil Beam (PB) algorithms using measurement as the gold standard. Methods: Ion chamber and diode measurements were taken for 6, 10, and 18 MV beams in a phantom made up of slab densities corresponding to solid water, lung, and bone. The phantom was setup at source-to-surface distance of 100 cm, and the field sizes were 3.0 × 3.0, 5.0 × 5.0, and 10.0 × 10.0 cm2. Data from the planning systems were computed along the central axis of the beam. The measurements were taken using a pinpoint chamber and edge diode for interface regions. Results: The best agreement between data from the algorithms and our measurements occurs away from the slab interfaces. For the 6 MV beam, iPlan 4.1 MC software performs the best with 1.7% absolute average percent difference from measurement. For the 10 MV beam, iPlan 4.1 PB performs the best with 2.7% absolute average percent difference from measurement. For the 18 MV beam, Acuros performs the best with 2.0% absolute average percent difference from measurement. It is interesting to note that the steepest drop in dose occurred the at lung heterogeneity-solid water interface of the18 MV, 3.0 × 3.0 cm2 field size setup. In this situation, Acuros and AAA performed best with an average percent difference within −1.1% of measurement, followed by iPlan 4.1 MC, which was within 4.9%. Conclusion: This study shows that all of the algorithms perform reasonably well in computing dose in a heterogeneous slab phantom. Moreover, Acuros and AAA perform particularly well at the lung-solid water interfaces for higher energy beams and small field sizes.

  6. Embolisation of recently ruptured intracranial aneurysms.

    PubMed Central

    Byrne, J V; Molyneux, A J; Brennan, R P; Renowden, S A

    1995-01-01

    Patients with subarachnoid haemorrhage due to the rupture of aneurysms unsuitable for craniotomy and clipping have been treated by coil embolisation within three weeks. Sixty nine of 75 consecutive patients were successfully treated. Procedure related complications occurred in 10 patients, resulting in permanent neurological deficits in three and one death (4.8%). The Glasgow outcome scores at six weeks were 53 grade 1, seven grade 2, four grade 3, and five grade 5. These results are comparable with surgical series despite a high proportion of aneurysms in the posterior cerebral circulation. Images PMID:7500100

  7. Anisotropy in rupture lines of paper sheets

    NASA Astrophysics Data System (ADS)

    Menezes-Sobrinho, I. L.; Couto, M. S.; Ribeiro, I. R. B.

    2005-06-01

    We have experimentally investigated the fracture process in paper samples submitted to a uniaxial force. Five types of paper sheets (newsprint, towel, sulfite, silk, and couche papers) were fractured along two orthogonal orientations. In order to characterize the rupture lines of the paper sheets we utilized the Hurst exponent. Our results indicate a dependence of the Hurst exponent on the orientation of the paper sheets for samples of newsprint and, probably, towel and silk papers. For the other types of paper the Hurst exponent does not depend on the direction of crack propagation.

  8. Anisotropy in rupture lines of paper sheets.

    PubMed

    Menezes-Sobrinho, I L; Couto, M S; Ribeiro, I R B

    2005-06-01

    We have experimentally investigated the fracture process in paper samples submitted to a uniaxial force. Five types of paper sheets (newsprint, towel, sulfite, silk, and couche papers) were fractured along two orthogonal orientations. In order to characterize the rupture lines of the paper sheets we utilized the Hurst exponent. Our results indicate a dependence of the Hurst exponent on the orientation of the paper sheets for samples of newsprint and, probably, towel and silk papers. For the other types of paper the Hurst exponent does not depend on the direction of crack propagation. PMID:16089834

  9. Complex earthquake rupture and local tsunamis

    USGS Publications Warehouse

    Geist, E.L.

    2002-01-01

    In contrast to far-field tsunami amplitudes that are fairly well predicted by the seismic moment of subduction zone earthquakes, there exists significant variation in the scaling of local tsunami amplitude with respect to seismic moment. From a global catalog of tsunami runup observations this variability is greatest for the most frequently occuring tsunamigenic subduction zone earthquakes in the magnitude range of 7 < Mw < 8.5. Variability in local tsunami runup scaling can be ascribed to tsunami source parameters that are independent of seismic moment: variations in the water depth in the source region, the combination of higher slip and lower shear modulus at shallow depth, and rupture complexity in the form of heterogeneous slip distribution patterns. The focus of this study is on the effect that rupture complexity has on the local tsunami wave field. A wide range of slip distribution patterns are generated using a stochastic, self-affine source model that is consistent with the falloff of far-field seismic displacement spectra at high frequencies. The synthetic slip distributions generated by the stochastic source model are discretized and the vertical displacement fields from point source elastic dislocation expressions are superimposed to compute the coseismic vertical displacement field. For shallow subduction zone earthquakes it is demonstrated that self-affine irregularities of the slip distribution result in significant variations in local tsunami amplitude. The effects of rupture complexity are less pronounced for earthquakes at greater depth or along faults with steep dip angles. For a test region along the Pacific coast of central Mexico, peak nearshore tsunami amplitude is calculated for a large number (N = 100) of synthetic slip distribution patterns, all with identical seismic moment (Mw = 8.1). Analysis of the results indicates that for earthquakes of a fixed location, geometry, and seismic moment, peak nearshore tsunami amplitude can vary by a

  10. Therapeutic Prospect of Adipose-Derived Stromal Cells for the Treatment of Abdominal Aortic Aneurysm.

    PubMed

    Parvizi, Mojtaba; Harmsen, Martin C

    2015-07-01

    Aneurysm refers to the dilation of the vessel wall for more than 50%. Abdominal aortic aneurysm (AAA) refers to the dilation and weakening of all three layers of the abdominal aorta, which mostly occur infrarenally. The population aged above 50 years is at risk of AAA development, while a familiar history doubles the risk. Progression of AAA can cause immanent rupture of the vascular wall and has a high mortality and morbidity risk. They are additional risk factors for AAA development such as gender, smoking, and dyslipidemia. In general, pathological features of AAA include inflammation, degradation of the extracellular matrix (ECM), and smooth muscle cell apoptosis. The main pathophysiology of AAA development is still unknown. Besides available treatment modalities for large AAA, which associate with a high mortality risk, effective, alternative, and safer treatments are required, preferably already at an early stage of AAA. For the last decades, tissue engineering and regenerative medicine showed promising potential therapeutic effects for various (cardiovascular) diseases, including AAA. Adipose tissue-derived stromal cells (ADSC) are a candidate source of stem cells for regenerative medicine. ADSC are isolated from adipose tissue with low risk and are easily cultured and expanded while maintaining their multipotency. In addition, due to their differentiation capacity and trophic factor production, ADSC serve an important role in tissue engineering and regenerative medicine modalities. In this review, we will highlight the main pathobiology of AAA and introduce ADSC as a new promising therapeutic source for small AAA.

  11. Stress rupture resistance. [of Co and Ni superalloys

    NASA Technical Reports Server (NTRS)

    Freche, J. C.

    1976-01-01

    Principles underlying the design of metallic systems for stress rupture resistance are outlined by considering the specific case studies of cobalt- and nickel-base superalloys. Ways in which superalloys can be designed for high stress rupture resistance are discussed. In describing the alloying procedures, the strengthening mechanisms involved and methods of avoiding phases detrimental to stress rupture resistance are identified. New processing techniques such as controlled solidification, prealloyed powder processing, and autoclave heat treatments are described as further means of achieving increased stress rupture resistance in superalloy and other systems.

  12. Rupture of giant vertebrobasilar aneurysm following flow diversion: mechanical stretch as a potential mechanism for early aneurysm rupture.

    PubMed

    Fox, Benjamin; Humphries, William Edward; Doss, Vinodh T; Hoit, Daniel; Elijovich, Lucas; Arthur, Adam S

    2014-01-01

    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. PMID:25355741

  13. Rupture of giant vertebrobasilar aneurysm following flow diversion: mechanical stretch as a potential mechanism for early aneurysm rupture.

    PubMed

    Fox, Benjamin; Humphries, William Edward; Doss, Vinodh T; Hoit, Daniel; Elijovich, Lucas; Arthur, Adam S

    2015-11-01

    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. PMID:25361560

  14. Targeting the AAA ATPase p97 as an approach to treat cancer through disruption of protein homeostasis

    PubMed Central

    Anderson, Daniel J.; Le Moigne, Ronan; Djakovic, Stevan; Kumar, Brajesh; Rice, Julie; Wong, Steve; Wang, Jinhai; Yao, Bing; Valle, Eduardo; von Soly, Szerenke Kiss; Madriaga, Antonett; Soriano, Ferdie; Menon, Mary-Kamala; Wu, Zhi Yong; Kampmann, Martin; Chen, Yuwen; Weissman, Jonathan S.; Aftab, Blake T.; Yakes, F. Michael; Shawver, Laura; Zhou, Han-Jie; Wustrow, David; Rolfe, Mark

    2016-01-01

    Summary p97 is a AAA-ATPase with multiple cellular functions, one of which is critical regulation of protein homeostasis pathways. We describe the characterization of CB-5083, a potent, selective and orally bioavailable inhibitor of p97. Treatment of tumor cells with CB-5083 leads to accumulation of poly-ubiquitinated proteins, retention of endoplasmic reticulum associated degradation (ERAD) substrates and generation of irresolvable proteotoxic stress leading to activation of the apoptotic arm of the unfolded protein response (UPR). In xenograft models, CB-5083 causes modulation of key p97-related pathways, induces apoptosis and has antitumor activity in a broad range of both hematological and solid tumor models. Molecular determinants of CB-5083 activity include expression of genes in the ERAD pathway providing a potential strategy for patient selection. PMID:26555175

  15. The Pex1/Pex6 complex is a heterohexameric AAA+ motor with alternating and highly coordinated subunits

    PubMed Central

    Gardner, Brooke M.; Chowdhury, Saikat; Lander, Gabriel C.; Martin, Andreas

    2015-01-01

    Pex1 and Pex6 are Type-2 AAA+ ATPases required for the de-novo biogenesis of peroxisomes. Mutations in Pex1 and Pex6 account for the majority of the most severe forms of peroxisome biogenesis disorders in humans. Here we show that the ATP-dependent complex of Pex1 and Pex6 from S. cerevisiae is a heterohexamer with alternating subunits. Within the Pex1/Pex6 complex, only the D2 ATPase ring hydrolyzes ATP, while nucleotide binding in the D1 ring promotes complex assembly. ATP hydrolysis by Pex1 is highly coordinated with that of Pex6. Furthermore, Pex15, the membrane anchor required for Pex1/Pex6 recruitment to peroxisomes inhibits the ATP-hydrolysis activity of Pex1/Pex6. PMID:25659908

  16. Acute cyst rupture, hemorrhage and septic shock after a shockwave lithotripsy in a patient with autosomal dominant polycystic kidney disease.

    PubMed

    Kim, Hyeong Gon; Bae, Sang Rak; Lho, Yong Soo; Park, Hyoung Keun; Paick, Sung Hyun

    2013-06-01

    The incidence of urinary calculi in autosomal dominant polycystic kidney disease (ADPKD) ranges from 10 to 36 %. Shockwave lithotripsy (SWL) for urinary calculi in ADPKD was reported to be a safe and effective treatment option. However, there is a potential risk of cyst rupture and traumatic hemorrhage because of shockwaves. A 39-year-old female with polycystic kidneys and upper ureter stone was treated with SWL and developed life-threatening complications of cyst rupture, traumatic hemorrhage and septic shock. She was initially treated with supportive care in the intensive care unit, but in the end nephrectomy was performed.

  17. Expanding Endovascular Therapy of Very Small Ruptured Aneurysms with the 1.5-mm Coil

    PubMed Central

    Nguyen, Thanh N.; Masoud, Hesham; Tarlov, Nicholas; Holsapple, James; Chin, Lawrence S.; Norbash, Alexander M.

    2015-01-01

    Background Very small ruptured aneurysms (≤3 mm) demonstrate a significant risk for procedural rupture with endovascular therapy. Since 2007, 1.5-mm-diameter coils have been available (Micrus, Microvention, and ev3), allowing neurointerventionalists the opportunity to offer patients with very small aneurysms endovascular treatment. In this study, we review the clinical and angiographic outcome of patients with very small ruptured aneurysms treated with the 1.5-mm coil. Methods This is a retrospective cohort study in which we examined consecutive ruptured very small aneurysms treated with coil embolization at a single institution. The longest linear aneurysm was recorded, even if the first coil was sized to a smaller transverse diameter. Very small aneurysms were defined as ≤3 mm. Descriptive results are presented. Results From July 2007 to March 2015, 81 aneurysms were treated acutely with coils in 78 patients presenting with subarachnoid hemorrhage. There were 5 patients with 3-mm aneurysms, of which the transverse diameter was ≤2 mm in 3 patients. In all 5 patients, a balloon was placed for hemostatic prophylaxis in case of rupture, and a single 1.5-mm coil was inserted for aneurysm treatment without complication. Complete aneurysm occlusion was achieved in 1 patient, residual neck in 2, and residual aneurysm in 2 patients. Aneurysm recanalization was present in 2 patients with an anterior communicating artery aneurysm; a recoiling attempt was unsuccessful in 1 of these 2 patients due to inadvertent displacement and distal coil embolization, but subsequent surgical clipping was successful. Another patient was retreated by surgical clipping for a residual wide-neck carotid terminus aneurysm. One patient died of ventriculitis 3 weeks after presentation; all 4 other patients had an excellent outcome with no rebleed at follow-up (mean 21 months, range 1-62). Conclusion The advent of the 1.5-mm coil may be used in the endovascular treatment of patients with very

  18. The repetition of large-earthquake ruptures.

    PubMed Central

    Sieh, K

    1996-01-01

    This survey of well-documented repeated fault rupture confirms that some faults have exhibited a "characteristic" behavior during repeated large earthquakes--that is, the magnitude, distribution, and style of slip on the fault has repeated during two or more consecutive events. In two cases faults exhibit slip functions that vary little from earthquake to earthquake. In one other well-documented case, however, fault lengths contrast markedly for two consecutive ruptures, but the amount of offset at individual sites was similar. Adjacent individual patches, 10 km or more in length, failed singly during one event and in tandem during the other. More complex cases of repetition may also represent the failure of several distinct patches. The faults of the 1992 Landers earthquake provide an instructive example of such complexity. Together, these examples suggest that large earthquakes commonly result from the failure of one or more patches, each characterized by a slip function that is roughly invariant through consecutive earthquake cycles. The persistence of these slip-patches through two or more large earthquakes indicates that some quasi-invariant physical property controls the pattern and magnitude of slip. These data seem incompatible with theoretical models that produce slip distributions that are highly variable in consecutive large events. Images Fig. 3 Fig. 7 Fig. 9 PMID:11607662

  19. Probability of rupture of multiple fault segments

    USGS Publications Warehouse

    Andrews, D.J.; Schwerer, E.

    2000-01-01

    Fault segments identified from geologic and historic evidence have sometimes been adopted as features limiting the likely extends of earthquake ruptures. There is no doubt that individual segments can sometimes join together to produce larger earthquakes. This work is a trial of an objective method to determine the probability of multisegment ruptures. The frequency of occurrence of events on all conjectured combinations of adjacent segments in northern California is found by fitting to both geologic slip rates and to an assumed distribution of event sizes for the region as a whole. Uncertainty in the shape of the distribution near the maximum magnitude has a large effect on the solution. Frequencies of individual events cannot be determined, but it is possible to find a set of frequencies to fit a model closely. A robust conclusion for the San Francisco Bay region is that large multisegment events occur on the San Andreas and San Gregorio faults, but single-segment events predominate on the extended Hayward and Calaveras strands of segments.

  20. Structural Characterization of a Newly Identified Component of α-Carboxysomes: The AAA+ Domain Protein CsoCbbQ

    SciTech Connect

    Sutter, Markus; Roberts, Evan W.; Gonzalez, Raul C.; Bates, Cassandra; Dawoud, Salma; Landry, Kimberly; Cannon, Gordon C.; Heinhorst, Sabine; Kerfeld, Cheryl A.

    2015-11-05

    Carboxysomes are bacterial microcompartments that enhance carbon fixation by concentrating ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) and its substrate CO2 within a proteinaceous shell. They are found in all cyanobacteria, some purple photoautotrophs and many chemoautotrophic bacteria. Carboxysomes consist of a protein shell that encapsulates several hundred molecules of RuBisCO, and contain carbonic anhydrase and other accessory proteins. Genes coding for carboxysome shell components and the encapsulated proteins are typically found together in an operon. The α-carboxysome operon is embedded in a cluster of additional, conserved genes that are presumably related to its function. In many chemoautotrophs, products of the expanded carboxysome locus include CbbO and CbbQ, a member of the AAA+ domain superfamily. We bioinformatically identified subtypes of CbbQ proteins and show that their genes frequently co-occur with both Form IA and Form II RuBisCO. The α-carboxysome-associated ortholog, CsoCbbQ, from Halothiobacillus neapolitanus forms a hexamer in solution and hydrolyzes ATP. The crystal structure shows that CsoCbbQ is a hexamer of the typical AAA+ domain; the additional C-terminal domain, diagnostic of the CbbQ subfamily, structurally fills the inter-monomer gaps, resulting in a distinctly hexagonal shape. Finally, we show that CsoCbbQ interacts with CsoCbbO and is a component of the carboxysome shell, the first example of ATPase activity associated with a bacterial microcompartment.

  1. Structural Characterization of a Newly Identified Component of α-Carboxysomes: The AAA+ Domain Protein CsoCbbQ

    DOE PAGES

    Sutter, Markus; Roberts, Evan W.; Gonzalez, Raul C.; Bates, Cassandra; Dawoud, Salma; Landry, Kimberly; Cannon, Gordon C.; Heinhorst, Sabine; Kerfeld, Cheryl A.

    2015-11-05

    Carboxysomes are bacterial microcompartments that enhance carbon fixation by concentrating ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) and its substrate CO2 within a proteinaceous shell. They are found in all cyanobacteria, some purple photoautotrophs and many chemoautotrophic bacteria. Carboxysomes consist of a protein shell that encapsulates several hundred molecules of RuBisCO, and contain carbonic anhydrase and other accessory proteins. Genes coding for carboxysome shell components and the encapsulated proteins are typically found together in an operon. The α-carboxysome operon is embedded in a cluster of additional, conserved genes that are presumably related to its function. In many chemoautotrophs, products of the expanded carboxysome locusmore » include CbbO and CbbQ, a member of the AAA+ domain superfamily. We bioinformatically identified subtypes of CbbQ proteins and show that their genes frequently co-occur with both Form IA and Form II RuBisCO. The α-carboxysome-associated ortholog, CsoCbbQ, from Halothiobacillus neapolitanus forms a hexamer in solution and hydrolyzes ATP. The crystal structure shows that CsoCbbQ is a hexamer of the typical AAA+ domain; the additional C-terminal domain, diagnostic of the CbbQ subfamily, structurally fills the inter-monomer gaps, resulting in a distinctly hexagonal shape. Finally, we show that CsoCbbQ interacts with CsoCbbO and is a component of the carboxysome shell, the first example of ATPase activity associated with a bacterial microcompartment.« less

  2. Structural Characterization of a Newly Identified Component of α-Carboxysomes: The AAA+ Domain Protein CsoCbbQ

    PubMed Central

    Sutter, Markus; Roberts, Evan W.; Gonzalez, Raul C.; Bates, Cassandra; Dawoud, Salma; Landry, Kimberly; Cannon, Gordon C.; Heinhorst, Sabine; Kerfeld, Cheryl A.

    2015-01-01

    Carboxysomes are bacterial microcompartments that enhance carbon fixation by concentrating ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) and its substrate CO2 within a proteinaceous shell. They are found in all cyanobacteria, some purple photoautotrophs and many chemoautotrophic bacteria. Carboxysomes consist of a protein shell that encapsulates several hundred molecules of RuBisCO, and contain carbonic anhydrase and other accessory proteins. Genes coding for carboxysome shell components and the encapsulated proteins are typically found together in an operon. The α-carboxysome operon is embedded in a cluster of additional, conserved genes that are presumably related to its function. In many chemoautotrophs, products of the expanded carboxysome locus include CbbO and CbbQ, a member of the AAA+ domain superfamily. We bioinformatically identified subtypes of CbbQ proteins and show that their genes frequently co-occur with both Form IA and Form II RuBisCO. The α-carboxysome-associated ortholog, CsoCbbQ, from Halothiobacillus neapolitanus forms a hexamer in solution and hydrolyzes ATP. The crystal structure shows that CsoCbbQ is a hexamer of the typical AAA+ domain; the additional C-terminal domain, diagnostic of the CbbQ subfamily, structurally fills the inter-monomer gaps, resulting in a distinctly hexagonal shape. We show that CsoCbbQ interacts with CsoCbbO and is a component of the carboxysome shell, the first example of ATPase activity associated with a bacterial microcompartment. PMID:26538283

  3. In vitro propagation and assessment of the genetic fidelity of Musa acuminata (AAA) cv. Vaibalhla derived from immature male flowers.

    PubMed

    Hrahsel, Lalremsiami; Basu, Adreeja; Sahoo, Lingaraj; Thangjam, Robert

    2014-02-01

    An efficient in vitro propagation method has been developed for the first time for Musa acuminata (AAA) cv. Vaibalhla, an economically important banana cultivar of Mizoram, India. Immature male flowers were used as explants. Murashige and Skoog's (MS) medium supplemented with plant growth regulators (PGRs) were used for the regeneration process. Out of different PGR combinations, MS medium supplemented with 2 mg L(-1) 6-benzylaminopurine (BAP) + 0.5 mg L(-1) α-naphthalene acetic acid (NAA) was optimal for production of white bud-like structures (WBLS). On this medium, explants produced the highest number of buds per explant (4.30). The highest percentage (77.77) and number (3.51) of shoot formation from each explants was observed in MS medium supplemented with 2 mg L(-1) kinetin + 0.5 mg L(-1) NAA. While MS medium supplemented with a combination of 2 mg L(-1) BAP + 0.5 mg L(-1) NAA showed the maximum shoot length (14.44 cm). Rooting efficiency of the shoots was highest in the MS basal medium without any PGRs. The plantlets were hardened successfully in the greenhouse with 96% survival rate. Random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) markers were employed to assess the genetic stability of in vitro regenerated plantlets of M. acuminata (AAA) cv. Vaibalhla. Eight RAPD and 8 ISSR primers were successfully used for the analysis from the 40 RAPD and 30 ISSR primers screened initially. The amplified products were monomorphic across all the regenerated plants and were similar to the mother plant. The present standardised protocol will find application in mass production, conservation and genetic transformation studies of this commercially important banana.

  4. Asymptomatic spontaneous complete uterine rupture in a term pregnancy after uterine packing during previous caesarean section: a case report.

    PubMed

    Zhang, J; Chen, S F; Luo, Y E

    2014-01-01

    Uterine rupture is a life-threatening obstetrical complication with significant neonatal and maternal morbidity. The authors report a 36-year-old woman with a history of previous caesarean section because of pre-eclampsia and antepartum haemorrhage at 31 gestational weeks during her first pregnancy. Postpartum haemorrhage occurred and the uterine cavity was packed with gauze for reducing blood loss. After two years, she underwent elective, repeat caesarean section at 38+1 gestational weeks with no abdominal pain or vaginal bleeding. During the operation, a six- to seven-cm-long defect was found in the lower uterine segment, with complete separation of the uterine scar and disruption of the visceral peritoneum. A live baby was delivered. The postoperative course was uneventful. Uterine dehiscence and rupture should be suspected in the presence of risk factors such as previous caesarean section, especially uterine packing involved. Spontaneous silent rupture can occur in women without any alarming symptoms.

  5. Expectant management of a herniated amniotic sac presenting as silent uterine rupture: a case report and literature review.

    PubMed

    Iemura, Asako; Kondoh, Eiji; Kawasaki, Kaoru; Fujita, Kohei; Ueda, Akihiko; Mogami, Haruta; Baba, Tsukasa; Konishi, Ikuo

    2015-01-01

    Foetal membranes bulging into the abdominal cavity is a unique initial manifestation of silent or complete uterine rupture during pregnancy. Since silent uterine rupture has potential risk for complete uterine rupture, which leads to acute life-threatening complications for both the mother and baby, it is difficult to determine whether to manage expectantly or surgically, including repair of the uterine wall or termination of the pregnancy, especially in the early second trimester. We present here a case of a herniated amniotic sac with overstretched uterine wall of the fundus presenting as silent uterine rupture, which was incidentally detected on routine ultrasonography at 18 weeks' gestation in a 38-year-old primigravida with a history of myomectomy for diffuse uterine leiomyomatosis. Magnetic resonance imaging examination revealed that the myometrium thickness was fully maintained at the site of the foetal membranes ballooning. The pregnancy was therefore managed expectantly and continued to successful delivery at 30 weeks' gestation. The precise assessment of the uterine wall may be essential to manage a herniated amniotic sac presenting as silent uterine rupture and to optimise the outcome of the pregnancy. We review all cases of a herniated amniotic sac out of focally overstretched uterine wall before 34 weeks' gestation.

  6. The association of Chlamydia trachomatis, Neisseria gonorrhoeae, and group B streptococci with preterm rupture of the membranes and pregnancy outcome.

    PubMed

    Alger, L S; Lovchik, J C; Hebel, J R; Blackmon, L R; Crenshaw, M C

    1988-08-01

    There is conflicting evidence regarding a possible causal role for Chlamydia trachomatis in the development of preterm premature rupture of the membranes. We investigated the relative prevalence of endocervical infection with C. trachomatis and group B streptococci in patients with preterm premature rupture of membranes compared with a control group taken from the same obstetric population. C. trachomatis was isolated from 23/52 (44%) patients with preterm premature rupture of membranes versus 13/84 (15%) women in the control group (p less than 0.001). This association was independent of infection with group B streptococci or Neisseria gonorrhoeae. Group B streptococci were isolated from 16% of the patients with preterm premature rupture of membranes versus 4% of the control population (p less than 0.05). The risk of preterm premature rupture of membranes associated with group B streptococcal infection was independent of infection with C. trachomatis and N. gonorrhoeae. Endocervical infection with C. trachomatis did not significantly affect early maternal complication rates after delivery.

  7. Pregnancy with a ruptured renal artery aneurysm: management concerns and endovascular management.

    PubMed

    Yadav, Siddharth; Sharma, Sanjay; Singh, Prabhjot; Nayak, Brusabhanu

    2015-01-01

    Renal artery aneurysm (RAA) affects <0.01% of the general population. Rupture of RAA is a rare catastrophe that can complicate pregnancy and is associated with high maternal and fetal mortality. Presentation is usually acute with severe flank pain, with or without haematuria, and haemodynamic instability requiring exploration and nephrectomy. A 26-year-old pregnant woman had sudden onset of gross haematuria and on evaluation was found to have a left RAA with an intrapelvic rupture and thinned out renal parenchyma. In view of the high risk of surgery, she was managed with endovascular placement of an Amplatzer type II vascular plug. Immediate and complete occlusion of blood flow was achieved and nephrectomy was avoided. Follow-up Doppler ultrasound revealed a reduced 5 cm mass in the left renal fossa with no internal flow and plug in position. She is currently on follow-up with 3-6 monthly ultrasonography not requiring any intervention. PMID:26504094

  8. [Ruptured fenestrated aneurysm of vertebral artery union successfully treated by endovascular surgery with GDC].

    PubMed

    Nishiguchi, Mitsuhisa; Sugiu, Kenji; Ohmoto, Takashi; Saijyo, Toshikazu; Fujisawa, Hiroyuki

    2002-08-01

    It is difficult to operate on ruptured basilar artery aneurysms in the acute phase because of the anatomical complexity, brain swelling, patients' medical condition, etc., but because there is some risk of rebleeding and/or vasospasm if surgery is delayed, early surgery is recommended. We encountered a rare case of ruptured fenestrated aneurysm of the vertebral artery (VA) union, treated it safely by endovascular surgery with Guglielmi detachable coils (GDCs) in the acute phase, and obtained a good outcome after intensive care. We therefore conclude that endovascular surgery with GDCs is a first-line therapy for fenestrated aneurysms of the VA union in the acute phase after subarachnoid hemorrhage. Fenestrated aneurysms of the VA union are very rare, and long-term follow-up is mandatory.

  9. Spontaneous rupture of the liver presenting as scrotal bruising.

    PubMed

    Vachharajani, A; Paes, B

    2001-05-01

    We describe a case of spontaneous rupture of the liver in a neonate, presenting with features consistent with testicular torsion. Ruptured liver has been well described in neonates following birth trauma, coagulation defects, and Group B Streptococcal infection. The etiology in our case remains undefined. PMID:11414525

  10. Diverse rupture processes in the 2015 Peru deep earthquake doublet.

    PubMed

    Ye, Lingling; Lay, Thorne; Kanamori, Hiroo; Zhan, Zhongwen; Duputel, Zacharie

    2016-06-01

    Earthquakes in deeply subducted oceanic lithosphere can involve either brittle or dissipative ruptures. On 24 November 2015, two deep (606 and 622 km) magnitude 7.5 and 7.6 earthquakes occurred 316 s and 55 km apart. The first event (E1) was a brittle rupture with a sequence of comparable-size subevents extending unilaterally ~50 km southward with a rupture speed of ~4.5 km/s. This earthquake triggered several aftershocks to the north along with the other major event (E2), which had 40% larger seismic moment and the same duration (~20 s), but much smaller rupture area and lower rupture speed than E1, indicating a more dissipative rupture. A minor energy release ~12 s after E1 near the E2 hypocenter, possibly initiated by the S wave from E1, and a clear aftershock ~165 s after E1 also near the E2 hypocenter, suggest that E2 was likely dynamically triggered. Differences in deep earthquake rupture behavior are commonly attributed to variations in thermal state between subduction zones. However, the marked difference in rupture behavior of the nearby Peru doublet events suggests that local variations of stress state and material properties significantly contribute to diverse behavior of deep earthquakes. PMID:27386585

  11. Diverse rupture processes in the 2015 Peru deep earthquake doublet

    PubMed Central

    Ye, Lingling; Lay, Thorne; Kanamori, Hiroo; Zhan, Zhongwen; Duputel, Zacharie

    2016-01-01

    Earthquakes in deeply subducted oceanic lithosphere can involve either brittle or dissipative ruptures. On 24 November 2015, two deep (606 and 622 km) magnitude 7.5 and 7.6 earthquakes occurred 316 s and 55 km apart. The first event (E1) was a brittle rupture with a sequence of comparable-size subevents extending unilaterally ~50 km southward with a rupture speed of ~4.5 km/s. This earthquake triggered several aftershocks to the north along with the other major event (E2), which had 40% larger seismic moment and the same duration (~20 s), but much smaller rupture area and lower rupture speed than E1, indicating a more dissipative rupture. A minor energy release ~12 s after E1 near the E2 hypocenter, possibly initiated by the S wave from E1, and a clear aftershock ~165 s after E1 also near the E2 hypocenter, suggest that E2 was likely dynamically triggered. Differences in deep earthquake rupture behavior are commonly attributed to variations in thermal state between subduction zones. However, the marked difference in rupture behavior of the nearby Peru doublet events suggests that local variations of stress state and material properties significantly contribute to diverse behavior of deep earthquakes. PMID:27386585

  12. Ruptured renal artery aneurysm: coil packing with GDCs.

    PubMed

    Takeuchi, Misako; Nakata, Manabu; Kawai, Akira; Suzuki, Kazumi; Morita, Tatsuo; Sugimoto, Hideharu

    2012-06-01

    Renal artery aneurysm (RAA) is a relatively uncommon occurrence, but it can be life-threatening when rupture (although rare) occurs. We present the successful endovascular treatment of a ruptured RAA, which was achieved by packing the aneurysm using Guglielmi and interlocking detachable coils.

  13. Diverse rupture processes in the 2015 Peru deep earthquake doublet.

    PubMed

    Ye, Lingling; Lay, Thorne; Kanamori, Hiroo; Zhan, Zhongwen; Duputel, Zacharie

    2016-06-01

    Earthquakes in deeply subducted oceanic lithosphere can involve either brittle or dissipative ruptures. On 24 November 2015, two deep (606 and 622 km) magnitude 7.5 and 7.6 earthquakes occurred 316 s and 55 km apart. The first event (E1) was a brittle rupture with a sequence of comparable-size subevents extending unilaterally ~50 km southward with a rupture speed of ~4.5 km/s. This earthquake triggered several aftershocks to the north along with the other major event (E2), which had 40% larger seismic moment and the same duration (~20 s), but much smaller rupture area and lower rupture speed than E1, indicating a more dissipative rupture. A minor energy release ~12 s after E1 near the E2 hypocenter, possibly initiated by the S wave from E1, and a clear aftershock ~165 s after E1 also near the E2 hypocenter, suggest that E2 was likely dynamically triggered. Differences in deep earthquake rupture behavior are commonly attributed to variations in thermal state between subduction zones. However, the marked difference in rupture behavior of the nearby Peru doublet events suggests that local variations of stress state and material properties significantly contribute to diverse behavior of deep earthquakes.

  14. Antibiotics after preterm premature rupture of the membranes.

    PubMed

    Singh, Katherine; Mercer, Brian

    2011-06-01

    Preterm premature rupture of the membranes remains a common cause of preterm deliveries and neonatal morbidities. The goal of this study is to review the evidence with regard to the antibiotic treatment after preterm premature rupture of the membranes, long-term outcomes related to antibiotic treatment, and possible complications with treatment. Future research goals are also discussed.

  15. The Resolution of Ruptures in the Therapeutic Alliance.

    ERIC Educational Resources Information Center

    Safran, Jeremy D.; Muran, J. Christopher

    1996-01-01

    A rupture in the therapeutic alliance is a deterioration in the quality of the relationship between patient and therapist; it is an interpersonal marker that indicates an opportunity for exploring and understanding the processes that maintain a maladaptive interpersonal schema. Outlines features of a research program on ruptures in the therapeutic…

  16. Spontaneous rupture of a liver hemangioma. A case report.

    PubMed

    Guillén-Paredes, María Pilar; Martínez Fernández, Josefa; Morales González, Álvaro; Pardo-García, José Luis

    2016-07-01

    Spontaneous rupture of a liver hemangioma is a very uncommon disease, but extremely seriousness because it is associated to a 75% of mortality caused by hipovolemic shock. A case of an spontaneous rupture of liver hemangioma, which was previously unknow, is presented. PMID:27659104

  17. Late rupture of extensor pollicis longus after wrist arthroscopy.

    PubMed

    Fortems, Y; Mawhinney, I; Lawrence, T; Trial, I A; Stanley, J K

    1995-06-01

    The first cases of impending rupture of the extensor pollicis longus after wrist arthroscopy are reported and the etiology is compared with extensor pollicis longus ruptures after nondisplaced or minimally displaced Colles fractures. Both cases were treated with extensor indices proprius to extensor pollicis longus transfer with good clinical results. PMID:7632309

  18. Repair of quadriceps tendon ruptures using suture anchors.

    PubMed

    Richards, David P; Barber, F Alan

    2002-01-01

    The repair of ruptured quadriceps tendon is commonly performed by weaving sutures through the ruptured tendon and then attaching the tendon to the bone by passing these sutures through tunnels in the superior patella. This technical note is the first report we are aware of in the English language literature of a technique that uses suture anchors to attach the tendon to bone.

  19. Simultaneous bilateral quadriceps tendon rupture while playing basketball.

    PubMed

    Shah, M; Jooma, N

    2002-04-01

    Simultaneous bilateral quadriceps tendon rupture is an uncommon injury in healthy people and only a few cases have been reported in athletes. This is the first report of a patient with simultaneous bilateral quadriceps tendon rupture incurred while playing basketball. The injury was surgically repaired and the patient had a good functional outcome.

  20. Earthquake rupture dynamics frozen in exhumed ancient faults.

    PubMed

    Di Toro, Giulio; Nielsen, Stefan; Pennacchioni, Giorgio

    2005-08-18

    Most of our knowledge about co-seismic rupture propagation is derived from inversion and interpretation of strong-ground-motion seismograms, laboratory experiments on rock and rock-analogue material, or inferred from theoretical and numerical elastodynamic models. However, additional information on dynamic rupture processes can be provided by direct observation of faults exhumed at the Earth's surface. Pseudotachylytes (solidified friction-induced melts) are the most certain fault-rock indicator of seismicity on ancient faults. Here we show how the asymmetry in distribution and the orientation of pseudotachylyte-filled secondary fractures around an exhumed fault can be used to reconstruct the earthquake rupture directivity, rupture velocity and fracture energy, by comparison with the theoretical dynamic stress field computed around propagating fractures. In particular, the studied natural network of pseudotachylytes is consistent with a dominant propagation direction during repeated seismic events and subsonic rupture propagation close to the Rayleigh wave velocity.

  1. Earthquake rupture stalled by a subducting fracture zone.

    PubMed

    Robinson, D P; Das, S; Watts, A B

    2006-05-26

    We showed that the rupture produced by the great Peru earthquake (moment magnitude 8.4) on 23 June 2001 propagated for approximately 70 kilometers before encountering a 6000-square-kilometer area of fault that acted as a barrier. The rupture continued around this barrier, which remained unbroken for approximately 30 seconds and then began to break when the main rupture front was approximately 200 kilometers from the epicenter. The barrier had relatively low rupture speed, slip, and aftershock density as compared to its surroundings, and the time of the main energy release in the earthquake coincided with the barrier's rupture. We associate this barrier with a fracture zone feature on the subducting oceanic plate.

  2. Material contrast does not predict earthquake rupture propagation direction

    USGS Publications Warehouse

    Harris, R.A.; Day, S.M.

    2005-01-01

    Earthquakes often occur on faults that juxtapose different rocks. The result is rupture behavior that differs from that of an earthquake occurring on a fault in a homogeneous material. Previous 2D numerical simulations have studied simple cases of earthquake rupture propagation where there is a material contrast across a fault and have come to two different conclusions: 1) earthquake rupture propagation direction can be predicted from the material contrast, and 2) earthquake rupture propagation direction cannot be predicted from the material contrast. In this paper we provide observational evidence from 70 years of earthquakes at Parkfield, CA, and new 3D numerical simulations. Both the observations and the numerical simulations demonstrate that earthquake rupture propagation direction is unlikely to be predictable on the basis of a material contrast. Copyright 2005 by the American Geophysical Union.

  3. [Tracheal rupture: delayed diagnosis with endobronchial intubation].

    PubMed

    Besmer, I; Schüpfer, G; Stulz, P; Jöhr, M

    2001-03-01

    Tracheobroncheal rupture is a rare complication of intubation techniques using a stylet. In this case report the patient was intubated by an emergency physician in a preclinical setting after a motor vehicle accident. Iatrogenic tracheal laceration was masked by inappropriate position of the endobronchial tube. By chance ventilation was maintained to both lungs by flow through the Murphy's eye of the tube and the lumen of the tube. In correcting the deep tube position after a chest x-ray laceration of the trachea was unmasked and ventilation problems occurred immediately. The tube was replaced under fiberoptical control and the patient was managed for surgical repair using a jet ventilation technique. In this case two complications of endobronchial intubation occurred, but the deep tube placement opposed the effects of the tracheal laceration. This was probably life saving for the patient during emergency transfer by helicopter after the accident. The anaesthesiological management during tracheal repair is discussed.

  4. Can Severe Kyphoscoliosis Lead to Aorta Rupture?

    PubMed

    Kotopoulos, Constantinos; Karakasi, Maria Valeria; Kapetanakis, Stylianos; Pavlidis, Pavlos

    2016-09-01

    Neurofibromatosis type 1 is a polysystemic disease presenting with a multifaceted clinical picture. Clinical manifestations may present in the skin, as well as in the skeletal and cardiovascular system. The present study aims to describe and examine the case of a 46-year-old woman, who suffered from neurofibromatosis type 1 and died abruptly in the emergency room. The forensic examination attributed her death to traumatic rupture of the thoracic aorta resulting from an acute angulation that her vertebral column formed in the thoracic region (severe kyphosis). Outspread cutaneous neurofibromas, severe scoliosis, and osteoporosis (brittle bones) were observed during the autopsy. No atherosclerotic lesions were detected in the aortic lumen. To the authors' knowledge, no similar case has been reported throughout relevant literature. PMID:27323279

  5. Children with ANSD fitted with hearing aids applying the AAA Pediatric Amplification Guideline: Current Practice and Outcomes

    PubMed Central

    Walker, Elizabeth A.; McCreery, Ryan W.; Spratford, Meredith; Roush, Patricia A.

    2015-01-01

    Background Up to 15% of children with permanent hearing loss have auditory neuropathy spectrum disorder (ANSD), which involves normal outer hair cell function and disordered afferent neural activity in the auditory nerve or brainstem. Given the varying presentations of ANSD in children, there is a need for more evidence-based research on appropriate clinical interventions for this population. Purpose This study compared the speech production, speech perception, and language outcomes of children with auditory neuropathy spectrum disorder (ANSD) who are hard of hearing and children with similar degrees of mild to moderately-severe sensorineural hearing loss (SNHL), all of whom were fitted with bilateral hearing aids based on the American Academy of Audiology (AAA) pediatric amplification guidelines. Research design Speech perception and communication outcomes data were gathered in a prospective accelerated longitudinal design, with entry into the study between six months and seven years of age. Three sites were involved in participant recruitment: Boys Town National Research Hospital, the University of North Carolina at Chapel Hill, and the University of Iowa. Study sample: The sample consisted of 12 children with ANSD and 22 children with SNHL. The groups were matched based on better-ear pure-tone average, better-ear aided speech intelligibility index, gender, maternal education level, and newborn hearing screening result (i.e., pass or refer). Data collection and analysis Children and their families participated in an initial baseline visit, followed by visits twice a year for children under age 2 years and once a year for children older than 2 years. Paired-sample t-tests were used to compare children with ANSD to children with SNHL. Results Paired t-tests indicated no significant differences between the ANSD and SNHL groups on language and articulation measures. Children with ANSD displayed functional speech perception skills in quiet. Although the number of

  6. Implementing the effect of the rupture directivity on PSHA maps: Application to the Marmara Region (Turkey)

    NASA Astrophysics Data System (ADS)

    Herrero, Andre; Spagnuolo, Elena; Akinci, Aybige; Pucci, Stefano

    2016-04-01

    In the present study we attempted to improve the seismic hazard assessment taking into account possible sources of epistemic uncertainty and the azimuthal variability of the ground motions which, at a particular site, is significantly influenced by the rupture mechanism and the rupture direction relative to the site. As a study area we selected Marmara Region (Turkey), especially the city of Istanbul which is characterized by one of the highest levels of seismic risk in Europe and the Mediterranean region. The seismic hazard in the city is mainly associated with two active fault segments which are located at about 20-30 km south of Istanbul. In this perspective first we proposed a methodology to incorporate this new information such as nucleation point in a probabilistic seismic hazard analysis (PSHA) framework. Secondly we introduced information about those fault segments by focusing on the fault rupture characteristics which affect the azimuthal variations of the ground motion spatial distribution i.e. source directivity effect and its influence on the probabilistic seismic hazard analyses (PSHA). An analytical model developed by Spudich and Chiou (2008) is used as a corrective factor that modifies the Next Generation Attenuation (NGA, Power et al. 2008) ground motion predictive equations (GMPEs) introducing rupture related parameters that generally lump together into the term directivity effect. We used the GMPEs as derived by the Abrahamson and Silva (2008) and the Boore and Atkinson (2008); our results are given in terms of 10% probability of exceedance of PSHA (at several periods from 0.5 s to 10 s) in 50 years on rock site condition; the correction for directivity introduces a significant contribution to the percentage ratio between the seismic hazards computed using the directivity model respect to the seismic hazard standard practice. In particular, we benefited the dynamic simulation from a previous study (Aochi & Utrich, 2015) aimed at evaluating the

  7. Factors Controlling Stress Rupture of Fiber-Reinforced Ceramic Composites

    NASA Technical Reports Server (NTRS)

    DiCarlo, J. A.; Yun, H. M.

    1999-01-01

    The successful application of fiber-reinforced ceramic matrix composites (CMC) depends strongly on maximizing material rupture life over a wide range of temperatures and applied stresses. The objective of this paper is to examine the various intrinsic and extrinsic factors that control the high-temperature stress rupture of CMC for stresses below and above those required for cracking of the 0 C plies (Regions I and II, respectively). Using creep-rupture results for a variety of ceramic fibers and rupture data for CMC reinforced by these fibers, it is shown that in those cases where the matrix carries little structural load, CMC rupture conditions can be predicted very well from the fiber behavior measured under the appropriate test environment. As such, one can then examine the intrinsic characteristics of the fibers in order to develop design guidelines for selecting fibers and fiber microstructures in order to maximize CMC rupture life. For those cases where the fiber interfacial coatings are unstable in the test environment, CMC lives are generally worse than those predicted by fiber behavior alone. For those cases where the matrix can support structural load, CMC life can even be greater provided matrix creep behavior is properly controlled. Thus the achievement of long CMC rupture life requires understanding and optimizing the behavior of all constituents in the proper manner.

  8. Daughter bubble cascades produced by folding of ruptured thin films.

    PubMed

    Bird, James C; de Ruiter, Riëlle; Courbin, Laurent; Stone, Howard A

    2010-06-10

    Thin liquid films, such as soap bubbles, have been studied extensively for over a century because they are easily formed and mediate a wide range of transport processes in physics, chemistry and engineering. When a bubble on a liquid-gas or solid-gas interface (referred to herein as an interfacial bubble) ruptures, the general expectation is that the bubble vanishes. More precisely, the ruptured thin film is expected to retract rapidly until it becomes part of the interface, an event that typically occurs within milliseconds. The assumption that ruptured bubbles vanish is central to theories on foam evolution and relevant to health and climate because bubble rupture is a source for aerosol droplets. Here we show that for a large range of fluid parameters, interfacial bubbles can create numerous small bubbles when they rupture, rather than vanishing. We demonstrate, both experimentally and numerically, that the curved film of the ruptured bubble can fold and entrap air as it retracts. The resulting toroidal geometry of the trapped air is unstable, leading to the creation of a ring of smaller bubbles. The higher pressure associated with the higher curvature of the smaller bubbles increases the absorption of gas into the liquid, and increases the efficiency of rupture-induced aerosol dispersal.

  9. Effect of Time-dependent Rupture on Tsunami Generation

    NASA Astrophysics Data System (ADS)

    Arcas, D.; Kanoglu, U.; Moore, C. W.; Aydin, B.

    2013-12-01

    Differential GPS data from the recent Chile 2009 and Japan 2011 seismic events have unveiled complex time-dependent ground motion dynamics during seismic rupture. Current tsunami modeling techniques usually ignore this time-dependent behavior in tsunami sources by assuming an instantaneous initial deformation field. Initial attempts to include time-dependent rupture behavior have motivated scientists to simulate this phenomenon as a series of instantaneous changes in the sea-floor. The present study investigates the effect of dynamic ground motion rupture on tsunami generation by including the time-dependent initial conditions in the derivation of the linear shallow-water wave equations. We then study the sensitivity of initial water surface deformation to time-dependent seafloor rupture by performing a parametric study of varying speed and rupture direction, while assuming a monotonic deformation from an initial pre-rupture state to a post-rupture final state. Numerical results for some selected scenarios are validated by comparing with analytical solutions of the non-homogeneous linear shallow-water equations.

  10. Daughter bubble cascades produced by folding of ruptured thin films.

    PubMed

    Bird, James C; de Ruiter, Riëlle; Courbin, Laurent; Stone, Howard A

    2010-06-10

    Thin liquid films, such as soap bubbles, have been studied extensively for over a century because they are easily formed and mediate a wide range of transport processes in physics, chemistry and engineering. When a bubble on a liquid-gas or solid-gas interface (referred to herein as an interfacial bubble) ruptures, the general expectation is that the bubble vanishes. More precisely, the ruptured thin film is expected to retract rapidly until it becomes part of the interface, an event that typically occurs within milliseconds. The assumption that ruptured bubbles vanish is central to theories on foam evolution and relevant to health and climate because bubble rupture is a source for aerosol droplets. Here we show that for a large range of fluid parameters, interfacial bubbles can create numerous small bubbles when they rupture, rather than vanishing. We demonstrate, both experimentally and numerically, that the curved film of the ruptured bubble can fold and entrap air as it retracts. The resulting toroidal geometry of the trapped air is unstable, leading to the creation of a ring of smaller bubbles. The higher pressure associated with the higher curvature of the smaller bubbles increases the absorption of gas into the liquid, and increases the efficiency of rupture-induced aerosol dispersal. PMID:20535206

  11. Rupture of the uterus in Malawi and Tanzania.

    PubMed

    Armon, P J

    1977-09-01

    This paper describes the presenting features and possible etiology of 115 cases of rupture of the uterus occurring in Malawi and Tanzania. The series included 62 spontaneous ruptures, 24 traumatic ruptures, and 29 scar ruptures. The rupture was complete in 100 cases but the peritoneum was intact in 15. 72 cases involved obstructed labor and 29 occurred in women with previous cesarean sections. Only 22% of subjects were grand multiparae (7 or more pregnancies), and the average parity was 4.5. Classical symptoms and signs either did not occur or were late in appearing in most cases, and none of the women complained of a tearing or bursting sensation. 23 of the cases died during treatment. Sterilization is recommended in cases where the initial rupture extends into or is primarily situated in the upper segment of the uterus due to the probability of recurrence. Delays in reaching medical care and a lack of medical facilities contribute to the incidence of uterine rupture in developing countries. Careful screening for at-riskmothers and use of partograms to diagnose cephalopelvic disproportion during labor would diminish the occurrence of this complication, however. Also recommended is avoidance of unnecessary cesarean section procedures and extreme caution in the management of patients with uterine scars. The limitation of family size and improvements in maternal haalth education are further important preventive measures.

  12. Interaction of dynamic rupture with small-scale heterogeneities

    NASA Astrophysics Data System (ADS)

    Galis, Martin; Mai, P. Martin

    2014-05-01

    Broadband ground motion simulations, with frequencies up to 10Hz, are important for engineering purposes, in particular for seismic hazard assessment for critical facilities. One problem in such simulations is the generation of high frequency radiation emitted during the dynamic rupture process. Ad-hoc kinematic rupture characterizations can be tweaked through empirical models to radiate over the desired frequency range, but their physical consistency remains questionable. In contrast, for physically self-consistent dynamic rupture modeling, controlled by friction, material parameters and the adopted physical laws, the mechanism that may lead to appropriate high-frequency radiation require heterogeneity in friction, stress, or fault geometry (or even all three quantities) at unknown but small length scales. Dunham at al. (2011) studied dynamic rupture propagation on rough faults in 2D, and described how fault roughness excites high-frequency radiation. In our study, we focus on the interaction of the dynamic rupture with small-scale heterogeneities on planar faults in 3D. We study effects of the interaction of dynamic rupture with 1) small-scale heterogeneities in the medium (that is, randomized 3D wave speed and density variations), and 2) small-scale heterogeneities in the frictional parameters. Our numerical results show significant variations in rupture velocity or peak slip velocity if small-scale heterogeneities are present. This indicates that the dynamic rupture is sensitive to both types of spatial inhomogeneity. At the same time we observe that the resulting near-source seismic wave fields are not very sensitive to these rupture variations, indicating that wavefront healing effects may "simplify" the complex seismic radiation once the waves propagated several wave-lengths away from the fault.

  13. Rupture Synchronicity in Complex Fault Systems

    NASA Astrophysics Data System (ADS)

    Milner, K. R.; Jordan, T. H.

    2013-12-01

    While most investigators would agree that the timing of large earthquakes within a fault system depends on stress-mediated interactions among its elements, much of the debate relevant to time-dependent forecasting has been centered on single-fault concepts, such as characteristic earthquake behavior. We propose to broaden this discussion by quantifying the multi-fault concept of rupture synchronicity. We consider a finite set of small, fault-spanning volumes {Vk} within a fault system of arbitrary (fractal) complexity. We let Ck be the catalog of length tmax comprising Nk discrete times {ti(k)} that mark when the kth volume participates in a rupture of magnitude > M. The main object of our analysis is the complete set of event time differences {τij(kk') = ti(k) - tj(k')}, which we take to be a random process with an expected density function ρkk'(t). When k = k', we call this function the auto-catalog density function (ACDF); when k ≠ k', we call it the cross-catalog density function (CCDF). The roles of the ACDF and CCDF in synchronicity theory are similar to those of autocorrelation and cross-correlation functions in time-series analysis. For a renewal process, the ACDF can be written in terms of convolutions of the interevent-time distribution, and many of its properties (e.g., large-t asymptote) can be derived analytically. The interesting information in the CCDF, like that in the ACDF, is concentrated near t = 0. If two catalogs are completely asynchronous, the CCDF collapses to an asymptote given by the harmonic mean of the ACDF asymptotes. Synchronicity can therefore be characterized by the variability of the CCDF about this asymptote. The brevity of instrumental catalogs makes the identification of synchronicity at large M difficult, but we will illustrate potentially interesting behaviors through the analysis of a million-year California catalog generated by the earthquake simulator, RSQSim (Deiterich & Richards-Dinger, 2010), which we sampled at a

  14. Neonatal outcome after prolonged rupture of the membranes starting in the second trimester.

    PubMed Central

    Blott, M; Greenough, A

    1988-01-01

    The neonatal outcomes of 30 pregnancies that were complicated by premature and prolonged rupture of the membranes that had started in the second trimester of pregnancy, were reviewed. The neonatal mortality was 11 (36%), the main cause of death being pulmonary hypoplasia. Two infants died of sepsis, but these were the only proved episodes of maternal or fetal infection. Of the survivors, 27% developed compressive limb abnormalities, all of which responded to passive physiotherapy. Pulmonary hypoplasia was significantly associated with earlier onset of rupture of the membranes, and the absence of fetal breathing movements. Compressive limb abnormalities were significantly associated with longer periods of oligohydramnios. We conclude that premature rupture of the membranes, even with onset in the second trimester, may be associated with a favourable outcome and this may be predicted by the persistence of fetal breathing movements. We therefore, recommend expectant management of such pregnancies, but suggest elective delivery at 34 weeks to limit fetal exposure to uterine compression and minimise the risks of prematurity. PMID:3196069

  15. [Successful endovascular repair of a ruptured thoracoabdominal aortic aneurysm with severe mural thrombus].

    PubMed

    Nakao, Yoshihisa; Akagi, Haruhiko; Irie, Hiroshi; Sakaguchi, Shoji; Sakai, Kei

    2014-11-01

    A 51-year-old man was transferred to our hospital on an emergency basis complaining of a sudden onset of severe left lumbar back pain. An emergency contrasted computed tomography showed a ruptured thoracoabdominal aortic aneurysm( rTAAA:Crawford classification type III). The ruptured site was near the aortic bifurcation, and the aneurysm had a relatively narrow segment with an extensive mural thrombus just below the renal arteries. Considering the high mortality of open surgery for the rTAAA and the poor general condition of the patient, we decided to perform endovascular aneurysm repair (EVAR) as a rescue procedure using the narrowed segment by the thrombus for a proximal landing zone. The abdominal part of the thoracoabdominal aortic aneurysm (TAAA) was successfully excluded with a stent graft to obtain complete hemostasis. The postoperative course was uneventful except for the need for hemodialysis. Even though there is a risk of developing late type 1 endoleak, this procedure can be a feasible option as a rescue procedure or a bridge to radical open surgery for ruptured TAAA in a specially anatomical setting like this case. PMID:25391465

  16. Combined uterine and urinary bladder rupture: an unusual complication of obstructed labor in a primigravida

    PubMed Central

    Takai, Idris Usman; Abubakar, Abdulkadir

    2016-01-01

    Background Combined uterine and urinary bladder rupture following prolonged obstructed labor is indeed a momentous uro-obstetric emergency. The urinary bladder involvement is distinctly rare in the absence of factors that predispose the bladder to be adherent to the lower uterine segment and is quite unusual in a primigravida. Objective To report a rare case of uterine rupture involving urinary bladder secondary to a prolonged obstructed labor in a primigravida from a low resource setting. Case A 17-year-old married unbooked primigravida who presented with a 3-day history of spontaneous onset of labor at term that was initially managed at home and later in a primary health care center where she had fundal pressure and oxytocin augmentation, respectively. The labor was complicated by combined uterine and urinary bladder rupture with sepsis. She was resuscitated and had exploratory laparotomy with uterine and urinary bladder repair. The postoperative period was uneventful and she was followed-up at the gynecology and family planning clinics. Conclusion There is a need for community reawakening on the inherent risks of teenage pregnancy, bad obstetric practices, and unsupervised pregnancy, labor, and delivery, particularly in the rural settings as in the index patient. A high index of suspicion and prompt appropriate intervention will reduce the sequel of morbidity and occasional mortality from this predicament. PMID:27499647

  17. Ruptured ileocolic artery aneurysm: an unusual cause of hemoperitoneum.

    PubMed

    Siddiqui, Zakaur R; Yousif, Omer F; Halliday, Mark W; Hubaishah, Nasser A; Adam, Khalid A

    2012-01-01

    Ruptured aneurysm of a branch of ileocolic artery is a rare finding and is an unusual cause of haemoperitoneum. Rapid diagnosis, and surgical or endovascular intervention are necessary to avoid devastating consequences and high mortality rates following an emergency operation after rupture. Resection is a good choice for surgical intervention for some aneurysms that are not suitable for endovascular repair. This report describes the case of a middle-aged man with a ruptured superior mesenteric artery branch aneurysm and his subsequent surgical management. PMID:23006464

  18. Ruptured Ileocolic Artery Aneurysm: An Unusual Cause of Hemoperitoneum

    PubMed Central

    Siddiqui, Zakaur R.; Yousif, Omer F.; Halliday, Mark W.; Hubaishah, Nasser A.; Adam, Khalid A.

    2012-01-01

    Ruptured aneurysm of a branch of ileocolic artery is a rare finding and is an unusual cause of haemoperitoneum. Rapid diagnosis, and surgical or endovascular intervention are necessary to avoid devastating consequences and high mortality rates following an emergency operation after rupture. Resection is a good choice for surgical intervention for some aneurysms that are not suitable for endovascular repair. This report describes the case of a middle-aged man with a ruptured superior mesenteric artery branch aneurysm and his subsequent surgical management. PMID:23006464

  19. MRI diagnosis of spontaneous uterine rupture of an unscarred uterus.

    PubMed

    Hruska, Karim M; Coughlin, Bret F; Coggins, Allahna A; Wiczyk, Halina P

    2006-05-01

    Spontaneous uterine rupture is a rare, potentially catastrophic complication of pregnancy, and its prompt diagnosis and treatment are essential in limiting morbidity and mortality. Clinical diagnosis is difficult and relies heavily on diagnostic imaging. Radiological diagnosis is also often difficult with most documented cases involving the use of ultrasound and computed tomography. Although magnetic resonance imaging (MRI) is being used more frequently to assess patients, there are few reports illustrating the utility of MRI and its advantages over other imaging modalities in the diagnosis of uterine rupture. This report documents a case of spontaneous uterine rupture diagnosed by MRI in a postpartum patient with an unscarred uterus.

  20. Spontaneous Uterine Rupture of an Unscarred Uterus before Labour.

    PubMed

    Guèye, Mamour; Mbaye, Magatte; Ndiaye-Guèye, Mame Diarra; Kane-Guèye, Serigne Modou; Diouf, Abdoul Aziz; Niang, Mouhamadou Mansour; Diaw, Hannegret; Moreau, Jean Charles

    2012-01-01

    Uterine rupture is a public health problem in developing countries. When it is spontaneous, it occurs most often during labor in a context of scarred uterus. Uterine rupture during pregnancy is a rare situation. The diagnosis is not always obvious and morbidity and maternal and fetal mortality is still high. We report a case of spontaneous uterine rupture during pregnancy at 35 weeks of an unscarred uterus before labour. This is an exceptional case that we observe for the first time in our unit.

  1. Uterine rupture at 10 weeks of gestation after laparoscopic myomectomy.

    PubMed

    Okada, Yoshiyuki; Hasegawa, Junichi; Mimura, Takashi; Arakaki, Tatsuya; Yoshikawa, Shinichiro; Yamashita, Yuka; Oba, Tomohiro; Nakamura, Masamitsu; Matsuoka, Ryu; Sekizawa, Akihiko

    2016-01-01

    The patient had a previous history of laparoscopic myomectomy. At 10 weeks of gestation, she visited our emergency center due to sudden abdominal pain. An ultrasound examination and MRI showed complete rupture of the uterine myometrium in the fundal wall and a floating gestation sac in Douglas' fossa with fluid. Emergency abdominal laparotomy was immediately performed due to the diagnosis of uterine rupture. During surgery, a small defect of the myometrium was found in the posterior fundal wall of the uterus. Two-layer suturing was performed at the perforation hole. The occasional occurrence of uterine rupture after surgery of the uterus even in the first trimester should be considered.

  2. Minimum Energy Path to Membrane Pore Formation and Rupture

    NASA Astrophysics Data System (ADS)

    Ting, Christina L.; Appelö, Daniel; Wang, Zhen-Gang

    2011-04-01

    We combine dynamic self-consistent field theory with the string method to calculate the minimum energy path to membrane pore formation and rupture. In the regime where nucleation can occur on experimentally relevant time scales, the structure of the critical nucleus is between a solvophilic stalk and a locally thinned membrane. Classical nucleation theory fails to capture these molecular details and significantly overestimates the free energy barrier. Our results suggest that thermally nucleated rupture may be an important factor for the low rupture strains observed in lipid membranes.

  3. The Pch2 AAA+ ATPase promotes phosphorylation of the Hop1 meiotic checkpoint adaptor in response to synaptonemal complex defects.

    PubMed

    Herruzo, Esther; Ontoso, David; González-Arranz, Sara; Cavero, Santiago; Lechuga, Ana; San-Segundo, Pedro A

    2016-09-19

    Meiotic cells possess surveillance mechanisms that monitor critical events such as recombination and chromosome synapsis. Meiotic defects resulting from the absence of the synaptonemal complex component Zip1 activate a meiosis-specific checkpoint network resulting in delayed or arrested meiotic progression. Pch2 is an evolutionarily conserved AAA+ ATPase required for the checkpoint-induced meiotic block in the zip1 mutant, where Pch2 is only detectable at the ribosomal DNA array (nucleolus). We describe here that high levels of the Hop1 protein, a checkpoint adaptor that localizes to chromosome axes, suppress the checkpoint defect of a zip1 pch2 mutant restoring Mek1 activity and meiotic cell cycle delay. We demonstrate that the critical role of Pch2 in this synapsis checkpoint is to sustain Mec1-dependent phosphorylation of Hop1 at threonine 318. We also show that the ATPase activity of Pch2 is essential for its checkpoint function and that ATP binding to Pch2 is required for its localization. Previous work has shown that Pch2 negatively regulates Hop1 chromosome abundance during unchallenged meiosis. Based on our results, we propose that, under checkpoint-inducing conditions, Pch2 also possesses a positive action on Hop1 promoting its phosphorylation and its proper distribution on unsynapsed chromosome axes. PMID:27257060

  4. Thyroid Hormone Receptor Interacting Protein 13 (TRIP13) AAA-ATPase Is a Novel Mitotic Checkpoint-silencing Protein*

    PubMed Central

    Wang, Kexi; Sturt-Gillespie, Brianne; Hittle, James C.; Macdonald, Dawn; Chan, Gordon K.; Yen, Tim J.; Liu, Song-Tao

    2014-01-01

    The mitotic checkpoint (or spindle assembly checkpoint) is a fail-safe mechanism to prevent chromosome missegregation by delaying anaphase onset in the presence of defective kinetochore-microtubule attachment. The target of the checkpoint is the E3 ubiquitin ligase anaphase-promoting complex/cyclosome. Once all chromosomes are properly attached and bioriented at the metaphase plate, the checkpoint needs to be silenced. Previously, we and others have reported that TRIP13 AAA-ATPase binds to the mitotic checkpoint-silencing protein p31comet. Here we show that endogenous TRIP13 localizes to kinetochores. TRIP13 knockdown delays metaphase-to-anaphase transition. The delay is caused by prolonged presence of the effector for the checkpoint, the mitotic checkpoint complex, and its association and inhibition of the anaphase-promoting complex/cyclosome. These results suggest that TRIP13 is a novel mitotic checkpoint-silencing protein. The ATPase activity of TRIP13 is essential for its checkpoint function, and interference with TRIP13 abolished p31comet-mediated mitotic checkpoint silencing. TRIP13 overexpression is a hallmark of cancer cells showing chromosomal instability, particularly in certain breast cancers with poor prognosis. We suggest that premature mitotic checkpoint silencing triggered by TRIP13 overexpression may promote cancer development. PMID:25012665

  5. Disassembly of mitotic checkpoint complexes by the joint action of the AAA-ATPase TRIP13 and p31comet

    PubMed Central

    Eytan, Esther; Wang, Kexi; Miniowitz-Shemtov, Shirly; Sitry-Shevah, Danielle; Kaisari, Sharon; Yen, Tim J.; Liu, Song-Tao; Hershko, Avram

    2014-01-01

    The mitotic (or spindle assembly) checkpoint system delays anaphase until all chromosomes are correctly attached to the mitotic spindle. When the checkpoint is active, a Mitotic Checkpoint Complex (MCC) assembles and inhibits the ubiquitin ligase Anaphase-Promoting Complex/Cyclosome (APC/C). MCC is composed of the checkpoint proteins Mad2, BubR1, and Bub3 associated with the APC/C activator Cdc20. When the checkpoint signal is turned off, MCC is disassembled and the checkpoint is inactivated. The mechanisms of the disassembly of MCC are not sufficiently understood. We have previously observed that ATP hydrolysis is required for the action of the Mad2-binding protein p31comet to disassemble MCC. We now show that HeLa cell extracts contain a factor that promotes ATP- and p31comet-dependent disassembly of a Cdc20–Mad2 subcomplex and identify it as Thyroid Receptor Interacting Protein 13 (TRIP13), an AAA-ATPase known to interact with p31comet. The joint action of TRIP13 and p31comet also promotes the release of Mad2 from MCC, participates in the complete disassembly of MCC and abrogates checkpoint inhibition of APC/C. We propose that TRIP13 plays centrally important roles in the sequence of events leading to MCC disassembly and checkpoint inactivation. PMID:25092294

  6. Multiple sequence signals direct recognition and degradation of protein substrates by the AAA+ protease HslUV.

    PubMed

    Sundar, Shankar; McGinness, Kathleen E; Baker, Tania A; Sauer, Robert T

    2010-10-29

    Proteolysis is important for protein quality control and for the proper regulation of many intracellular processes in prokaryotes and eukaryotes. Discerning substrates from other cellular proteins is a key aspect of proteolytic function. The Escherichia coli HslUV protease is a member of a major family of ATP-dependent AAA+ degradation machines. HslU hexamers recognize and unfold native protein substrates and then translocate the polypeptide into the degradation chamber of the HslV peptidase. Although a wealth of structural information is available for this system, relatively little is known about mechanisms of substrate recognition. Here, we demonstrate that mutations in the unstructured N-terminal and C-terminal sequences of two model substrates alter HslUV recognition and degradation kinetics, including changes in V(max). By introducing N- or C-terminal sequences that serve as recognition sites for specific peptide-binding proteins, we show that blocking either terminus of the substrate interferes with HslUV degradation, with synergistic effects when both termini are obstructed. These results support a model in which one terminus of the substrate is tethered to the protease and the other terminus is engaged by the translocation/unfolding machinery in the HslU pore. Thus, degradation appears to consist of discrete steps, which involve the interaction of different terminal sequence signals in the substrate with different receptor sites in the HslUV protease. PMID:20837023

  7. In-situ monitoring of blood glucose level for dialysis machine by AAA-battery-size ATR Fourier spectroscopy

    NASA Astrophysics Data System (ADS)

    Hosono, Satsuki; Sato, Shun; Ishida, Akane; Suzuki, Yo; Inohara, Daichi; Nogo, Kosuke; Abeygunawardhana, Pradeep K.; Suzuki, Satoru; Nishiyama, Akira; Wada, Kenji; Ishimaru, Ichiro

    2015-07-01

    For blood glucose level measurement of dialysis machines, we proposed AAA-battery-size ATR (Attenuated total reflection) Fourier spectroscopy in middle infrared light region. The proposed one-shot Fourier spectroscopic imaging is a near-common path and spatial phase-shift interferometer with high time resolution. Because numerous number of spectral data that is 60 (= camera frame rare e.g. 60[Hz]) multiplied by pixel number could be obtained in 1[sec.], statistical-averaging improvement realize high-accurate spectral measurement. We evaluated the quantitative accuracy of our proposed method for measuring glucose concentration in near-infrared light region with liquid cells. We confirmed that absorbance at 1600[nm] had high correlations with glucose concentrations (correlation coefficient: 0.92). But to measure whole-blood, complex light phenomenon caused from red blood cells, that is scattering and multiple reflection or so, deteriorate spectral data. Thus, we also proposed the ultrasound-assisted spectroscopic imaging that traps particles at standing-wave node. Thus, if ATR prism is oscillated mechanically, anti-node area is generated around evanescent light field on prism surface. By elimination complex light phenomenon of red blood cells, glucose concentration in whole-blood will be quantify with high accuracy. In this report, we successfully trapped red blood cells in normal saline solution with ultrasonic standing wave (frequency: 2[MHz]).

  8. Roles of the N domain of the AAA+ Lon protease in substrate recognition, allosteric regulation and chaperone activity.

    PubMed

    Wohlever, Matthew L; Baker, Tania A; Sauer, Robert T

    2014-01-01

    Degron binding regulates the activities of the AAA+ Lon protease in addition to targeting proteins for degradation. The sul20 degron from the cell-division inhibitor SulA is shown here to bind to the N domain of Escherichia coli Lon, and the recognition site is identified by cross-linking and scanning for mutations that prevent sul20-peptide binding. These N-domain mutations limit the rates of proteolysis of model sul20-tagged substrates and ATP hydrolysis by an allosteric mechanism. Lon inactivation of SulA in vivo requires binding to the N domain and robust ATP hydrolysis but does not require degradation or translocation into the proteolytic chamber. Lon-mediated relief of proteotoxic stress and protein aggregation in vivo can also occur without degradation but is not dependent on robust ATP hydrolysis. In combination, these results demonstrate that Lon can function as a protease or a chaperone and reveal that some of its ATP-dependent biological activities do not require translocation.

  9. The IbpA and IbpB small heat-shock proteins are substrates of the AAA+ Lon protease.

    PubMed

    Bissonnette, Sarah A; Rivera-Rivera, Izarys; Sauer, Robert T; Baker, Tania A

    2010-03-01

    Small heat-shock proteins (sHSPs) are a widely conserved family of molecular chaperones, all containing a conserved alpha-crystallin domain flanked by variable N- and C-terminal tails. We report that IbpA and IbpB, the sHSPs of Escherichia coli, are substrates for the AAA+ Lon protease. This ATP-fueled enzyme degraded purified IbpA substantially more slowly than purified IbpB, and we demonstrate that this disparity is a consequence of differences in maximal Lon degradation rates and not in substrate affinity. Interestingly, however, IbpB stimulated Lon degradation of IbpA both in vitro and in vivo. Furthermore, although the variable N- and C-terminal tails of the Ibps were dispensable for proteolytic recognition, these tails contain critical determinants that control the maximal rate of Lon degradation. Finally, we show that E. coli Lon degrades variants of human alpha-crystallin, indicating that Lon recognizes conserved determinants in the folded alpha-crystallin domain itself. These results suggest a novel mode for Lon substrate recognition and provide a highly suggestive link between the degradation and sHSP branches of the protein quality-control network.

  10. Random amplified polymorphic DNA (RAPD) detection of dwarf off-types in micropropagated Cavendish (Musa spp. AAA) bananas.

    PubMed

    Damasco, O P; Graham, G C; Henry, R J; Adkins, S W; Smiths, M K; Godwin, I D

    1996-11-01

    A RAPD marker specific to the dwarf off-type (hereafter known as dwarf) from micropropagation of Cavendish banana (Musa spp. AAA) cultivars New Guinea Cavendish and Williams was identified following an analysis of 57 normal (true-to-type) and 59 dwarf plants generated from several different micropropagation events. Sixty-six random decamer primers were used in the initial screen, of which 19 (28.8%) revealed polymorphisms between normal and dwarf plants. Primer OPJ-04 (5'-CCGAACACGG-3') was found to amplify an approx. 1.5 kb band which was consistently present in all normal but absent in all dwarf plants of both cultivars. Reliable detection of dwarf plants was achieved using this marker, providing the only available means ofin vitro detection of dwarfs. The use of this marker could facilitate early detection and elimination of dwarfs from batches of micropropagated bananas, and may be a useful tool in determining what factors in the tissue culture process lead to this off type production.Other micropropagation-induced RAPD polymorphisms were observed but were not associated with the dwarf trait. PMID:24178669

  11. The Pch2 AAA+ ATPase promotes phosphorylation of the Hop1 meiotic checkpoint adaptor in response to synaptonemal complex defects

    PubMed Central

    Herruzo, Esther; Ontoso, David; González-Arranz, Sara; Cavero, Santiago; Lechuga, Ana; San-Segundo, Pedro A.

    2016-01-01

    Meiotic cells possess surveillance mechanisms that monitor critical events such as recombination and chromosome synapsis. Meiotic defects resulting from the absence of the synaptonemal complex component Zip1 activate a meiosis-specific checkpoint network resulting in delayed or arrested meiotic progression. Pch2 is an evolutionarily conserved AAA+ ATPase required for the checkpoint-induced meiotic block in the zip1 mutant, where Pch2 is only detectable at the ribosomal DNA array (nucleolus). We describe here that high levels of the Hop1 protein, a checkpoint adaptor that localizes to chromosome axes, suppress the checkpoint defect of a zip1 pch2 mutant restoring Mek1 activity and meiotic cell cycle delay. We demonstrate that the critical role of Pch2 in this synapsis checkpoint is to sustain Mec1-dependent phosphorylation of Hop1 at threonine 318. We also show that the ATPase activity of Pch2 is essential for its checkpoint function and that ATP binding to Pch2 is required for its localization. Previous work has shown that Pch2 negatively regulates Hop1 chromosome abundance during unchallenged meiosis. Based on our results, we propose that, under checkpoint-inducing conditions, Pch2 also possesses a positive action on Hop1 promoting its phosphorylation and its proper distribution on unsynapsed chromosome axes. PMID:27257060

  12. Thyroid hormone receptor interacting protein 13 (TRIP13) AAA-ATPase is a novel mitotic checkpoint-silencing protein.

    PubMed

    Wang, Kexi; Sturt-Gillespie, Brianne; Hittle, James C; Macdonald, Dawn; Chan, Gordon K; Yen, Tim J; Liu, Song-Tao

    2014-08-22

    The mitotic checkpoint (or spindle assembly checkpoint) is a fail-safe mechanism to prevent chromosome missegregation by delaying anaphase onset in the presence of defective kinetochore-microtubule attachment. The target of the checkpoint is the E3 ubiquitin ligase anaphase-promoting complex/cyclosome. Once all chromosomes are properly attached and bioriented at the metaphase plate, the checkpoint needs to be silenced. Previously, we and others have reported that TRIP13 AAA-ATPase binds to the mitotic checkpoint-silencing protein p31(comet). Here we show that endogenous TRIP13 localizes to kinetochores. TRIP13 knockdown delays metaphase-to-anaphase transition. The delay is caused by prolonged presence of the effector for the checkpoint, the mitotic checkpoint complex, and its association and inhibition of the anaphase-promoting complex/cyclosome. These results suggest that TRIP13 is a novel mitotic checkpoint-silencing protein. The ATPase activity of TRIP13 is essential for its checkpoint function, and interference with TRIP13 abolished p31(comet)-mediated mitotic checkpoint silencing. TRIP13 overexpression is a hallmark of cancer cells showing chromosomal instability, particularly in certain breast cancers with poor prognosis. We suggest that premature mitotic checkpoint silencing triggered by TRIP13 overexpression may promote cancer development.

  13. Loss of the m-AAA protease subunit AFG₃L₂ causes mitochondrial transport defects and tau hyperphosphorylation.

    PubMed

    Kondadi, Arun Kumar; Wang, Shuaiyu; Montagner, Sara; Kladt, Nikolay; Korwitz, Anne; Martinelli, Paola; Herholz, David; Baker, Michael J; Schauss, Astrid C; Langer, Thomas; Rugarli, Elena I

    2014-05-01

    The m-AAA protease subunit AFG₃L₂ is involved in degradation and processing of substrates in the inner mitochondrial membrane. Mutations in AFG₃L₂ are associated with spinocerebellar ataxia SCA28 in humans and impair axonal development and neuronal survival in mice. The loss of AFG₃L₂ causes fragmentation of the mitochondrial network. However, the pathogenic mechanism of neurodegeneration in the absence of AFG₃L₂ is still unclear. Here, we show that depletion of AFG₃L₂ leads to a specific defect of anterograde transport of mitochondria in murine cortical neurons. We observe similar transport deficiencies upon loss of AFG₃L₂ in OMA1-deficient neurons, indicating that they are not caused by OMA1-mediated degradation of the dynamin-like GTPase OPA1 and inhibition of mitochondrial fusion. Treatment of neurons with antioxidants, such as N-acetylcysteine or vitamin E, or decreasing tau levels in axons restored mitochondrial transport in AFG₃L₂-depleted neurons. Consistently, tau hyperphosphorylation and activation of ERK kinases are detected in mouse neurons postnatally deleted for Afg3l2. We propose that reactive oxygen species signaling leads to cytoskeletal modifications that impair mitochondrial transport in neurons lacking AFG₃L₂.

  14. The Pch2 AAA+ ATPase promotes phosphorylation of the Hop1 meiotic checkpoint adaptor in response to synaptonemal complex defects.

    PubMed

    Herruzo, Esther; Ontoso, David; González-Arranz, Sara; Cavero, Santiago; Lechuga, Ana; San-Segundo, Pedro A

    2016-09-19

    Meiotic cells possess surveillance mechanisms that monitor critical events such as recombination and chromosome synapsis. Meiotic defects resulting from the absence of the synaptonemal complex component Zip1 activate a meiosis-specific checkpoint network resulting in delayed or arrested meiotic progression. Pch2 is an evolutionarily conserved AAA+ ATPase required for the checkpoint-induced meiotic block in the zip1 mutant, where Pch2 is only detectable at the ribosomal DNA array (nucleolus). We describe here that high levels of the Hop1 protein, a checkpoint adaptor that localizes to chromosome axes, suppress the checkpoint defect of a zip1 pch2 mutant restoring Mek1 activity and meiotic cell cycle delay. We demonstrate that the critical role of Pch2 in this synapsis checkpoint is to sustain Mec1-dependent phosphorylation of Hop1 at threonine 318. We also show that the ATPase activity of Pch2 is essential for its checkpoint function and that ATP binding to Pch2 is required for its localization. Previous work has shown that Pch2 negatively regulates Hop1 chromosome abundance during unchallenged meiosis. Based on our results, we propose that, under checkpoint-inducing conditions, Pch2 also possesses a positive action on Hop1 promoting its phosphorylation and its proper distribution on unsynapsed chromosome axes.

  15. Structural insights into the Escherichia coli lysine decarboxylases and molecular determinants of interaction with the AAA+ ATPase RavA

    PubMed Central

    Kandiah, Eaazhisai; Carriel, Diego; Perard, Julien; Malet, Hélène; Bacia, Maria; Liu, Kaiyin; Chan, Sze W. S.; Houry, Walid A.; Ollagnier de Choudens, Sandrine; Elsen, Sylvie; Gutsche, Irina

    2016-01-01

    The inducible lysine decarboxylase LdcI is an important enterobacterial acid stress response enzyme whereas LdcC is its close paralogue thought to play mainly a metabolic role. A unique macromolecular cage formed by two decamers of the Escherichia coli LdcI and five hexamers of the AAA+ ATPase RavA was shown to counteract acid stress under starvation. Previously, we proposed a pseudoatomic model of the LdcI-RavA cage based on its cryo-electron microscopy map and crystal structures of an inactive LdcI decamer and a RavA monomer. We now present cryo-electron microscopy 3D reconstructions of the E. coli LdcI and LdcC, and an improved map of the LdcI bound to the LARA domain of RavA, at pH optimal for their enzymatic activity. Comparison with each other and with available structures uncovers differences between LdcI and LdcC explaining why only the acid stress response enzyme is capable of binding RavA. We identify interdomain movements associated with the pH-dependent enzyme activation and with the RavA binding. Multiple sequence alignment coupled to a phylogenetic analysis reveals that certain enterobacteria exert evolutionary pressure on the lysine decarboxylase towards the cage-like assembly with RavA, implying that this complex may have an important function under particular stress conditions. PMID:27080013

  16. High-speed atomic force microscopic observation of ATP-dependent rotation of the AAA+ chaperone p97.

    PubMed

    Noi, Kentaro; Yamamoto, Daisuke; Nishikori, Shingo; Arita-Morioka, Ken-ichi; Kato, Takayuki; Ando, Toshio; Ogura, Teru

    2013-11-01

    p97 (also called VCP and CDC-48) is an AAA+ chaperone, which consists of a substrate/cofactor-binding N domain and two ATPase domains (D1 and D2), and forms a homo-hexameric ring. p97 plays crucial roles in a variety of cellular processes such as the ubiquitin-proteasome pathway, the endoplasmic reticulum-associated protein degradation, autophagy, and modulation of protein aggregates. Mutations in human p97 homolog VCP are linked to neurodegenerative diseases. The key mechanism of p97 in these various functions has been proposed to be the disassembly of protein complexes. To understand the molecular mechanism of p97, we studied the conformational changes of hexameric CDC-48.1, a Caenorhabditis elegans p97 homolog, using high-speed atomic force microscopy. In the presence of ATP, the N-D1 ring repeatedly rotates ~23 ± 8° clockwise and resets relative to the D2 ring. Mutational analysis reveals that this rotation is induced by ATP binding to the D2 domain. PMID:24055316

  17. Rupture Limit of Thin Moving Films

    NASA Astrophysics Data System (ADS)

    Padrino, Juan C.; Joseph, Daniel D.; Kim, Hyungjun

    2010-11-01

    The rupture of a thin film in another fluid is studied including the effects of disjoining pressure. The study considers the linear stability of a moving viscous film in a motionless inviscid fluid and of a stagnant viscous film in a motionless viscous fluid. These are analyzed by means of the Navier--Stokes equations and the dissipation approximation based on potential flow. Results reveal that the dissipation method provides a good approximation for the case of a moving film, whereas its predictions are off the mark for the stagnant film case. The thickness of the gap at the trough of Kelvin-Helmholtz waves locates the formation of holes. The wavelength at final collapse is determined by the length of waves at the trough of the corrugated film. The disjoining pressure effects cause very fast break-up for very thin films. These effects influence the cutoff wavenumber. In the limit of small gaps on this corrugated film, the Reynolds and Weber numbers tend to zero with the gap size, the Ohnesorge number increases like the reciprocal of the square root and the Hamaker number like the reciprocal of the square of the gap. The motion of the film does not enter at the point of formation of holes. Moreover, for the most unstable wave, the ratio of the wavelength to film thickness is found to decrease with decreasing film thickness.

  18. Extensor tendon ruptures after total knee arthroplasty.

    PubMed

    Bonnin, M; Lustig, S; Huten, D

    2016-02-01

    Extensor tendon rupture is a rare but serious complication after total knee arthroplasty (TKA) that impairs active knee extension, thereby severely affecting knee function. Surgery is usually required. Surgical options range from simple suturing to allograft reconstruction of the entire extensor mechanism and include intermediate methods such as reconstruction using neighbouring tendons or muscles, synthetic ligament implantation, and partial allograft repair. Simple suturing carries a high failure rate and should therefore be routinely combined with tissue augmentation using a neighbouring tendon or a synthetic ligament. After allograft reconstruction, outcomes are variable and long-term complications common. Salvage procedures for managing the most severe cases after allograft failure involve reconstruction using gastrocnemius or vastus flaps. Regardless of the technique used, suturing must be performed under tension, with the knee fully extended, and rehabilitation must be conducted with great caution. Weaknesses of available case-series studies include small sample sizes, heterogeneity, and inadequate follow-up duration. All treatment options are associated with substantial failure rates. The patient should be informed of this fact and plans made for a salvage option. Here, the main techniques and their outcomes are discussed, and a therapeutic strategy is suggested.

  19. Spontaneous ureteral rupture diagnosis and treatment.

    PubMed

    Pampana, E; Altobelli, S; Morini, M; Ricci, A; D'Onofrio, S; Simonetti, G

    2013-01-01

    Rupture of the urinary collecting system associated with perinephric or retroperitoneal extravasation of the urine is an unusual condition and it is commonly associated with renal obstructing disease. Perforation could occur at any level from the calix to the bladder but it is usually seen at the fornices and upper ureter. It may lead to several serious consequences including urinoma, abscess formation, urosepsis, infection, and subsequent irreversible renal impairment. We report a case of a 69-year-old woman who presented at the emergency department of our institution with severe abdominal pain. Due to symptomatology worsening, complete laboratory evaluation was performed and the patient underwent abdominal contrast enhanced computed tomography (CT) evaluation which showed contrast agent extravasation outside the excretory system without any evidence of renal calculi at basal acquisition. It was decided to perform a double-J stent placement which was followed by complete healing of the ureter and its removal was performed 8 weeks later. Diagnosis and therapeutic approaches are discussed. PMID:24455381

  20. Extracellular Matrix Dynamics and Fetal Membrane Rupture

    PubMed Central

    Strauss,, Jerome F.

    2013-01-01

    The extracellular matrix (ECM) plays an important role in determining cell and organ function: (1) it is an organizing substrate that provides tissue tensile strength; (2) it anchors cells and influences cell morphology and function via interaction with cell surface receptors; and (3) it is a reservoir for growth factors. Alterations in the content and the composition of the ECM determine its physical and biological properties, including strength and susceptibility to degradation. The ECM components themselves also harbor cryptic matrikines, which when exposed by conformational change or proteolysis have potent effects on cell function, including stimulating the production of cytokines and matrix metalloproteinases (MMPs). Collectively, these properties of the ECM reflect a dynamic tissue component that influences both tissue form and function. This review illustrates how defects in ECM synthesis and metabolism and the physiological process of ECM turnover contribute to changes in the fetal membranes that precede normal parturition and contribute to the pathological events leading to preterm premature rupture of membranes (PPROM). PMID:22267536

  1. Stress-rupture strength of alloy 718

    SciTech Connect

    Kennedy, R.L.; Cao, W.D.; Thomas, W.M.

    1996-03-01

    Alloy 718 is the most widely used of the nickel-base superalloys in aerospace applications such as compressor and turbine disks, cases, compressor blades and fasteners in aircraft gas-turbine engines. Since the development of the superalloy by Inco Alloys International over 30 years ago, researchers have made many slight modifications in chemical composition, and have refined process techniques to achieve further improvements in performance. Relatively little information on the effects of phosphorus has been published, and the available information is contradictory. However, phosphorus in superalloys is generally considered detrimental, and by specification is controlled to a low maximum value (0.015% max, for example, in AMS5662 E). This lack of data is the basis of a study by Teledyne Allvac to determine the effects of the interaction of phosphorus, boron, and carbon on the mechanical properties, processing characteristics, and microstructure of Allvac 718. Results show that a significant improvement in stress-rupture properties over those of a commercial Alloy 718 material is possible by optimizing phosphorus, boron, and carbon additions.

  2. Patellar tendon rupture in a basketball player.

    PubMed

    Johnson, Sean D; Kulig, Kornelia

    2009-11-01

    The patient was a 21-year-old male who was referred to physical therapy with a 1-week history of right knee pain and stiffness following an injury of traumatic onset. While attempting to jump off of both legs to dunk a basketball during a game, the patient heard and felt a pop in his right knee that was associated with an immediate onset of pain and swelling. He was unable to bear weight following the injury and, therefore, immediately went to the emergency department, where radiographs were completed and interpreted as negative for a fracture. However, the patella for the right knee was superiorly displaced. The patient was issued crutches and referred to physical therapy. At the time of the initial physical therapy examination, the patient was still not able to bear full weight on the right lower extremity or actively fully extend his right knee. Due to concern over possible meniscal, medial collateral ligament, or patellar tendon involvement, the patient's physician was contacted and magnetic resonance imaging was ordered. Five days later, the patient presented with decreased knee effusion and the special tests for the medial collateral ligament and meniscus were negative. However, the patient was still not able to actively extend his knee, suggesting a possible rupture of the patellar tendon, which was later confirmed on magnetic resonance imaging. Surgical repair of the patellar tendon was performed 2 weeks later.

  3. Vulnerability to rupture of the intact articular surface with respect to age and proximity to site of fibrillation: a dynamic and static-investigation.

    PubMed

    Flachsmann, René; Kim, Woong; Broom, Neil

    2005-01-01

    Bovine cartilage-on-bone samples taken from healthy mature patellae and from the intact regions of degenerate patellae were subjected to dynamic and static compressive loading. In-plane articular surface strain and rupture behavior were investigated and compared with previously published data obtained from immature bovine patellae. Both aging and proximity of the intact tested region to the fibrillated lesion increase the likelihood of articular surface rupture under both impact and static loading. Substantially higher levels of stress can be applied dynamically than statically without increasing the risk of articular surface rupture. Articular surface rupture is a result of lineal strains generated by the indentation profile, but any direct measurement of its in situ rupture strength is not possible. However, differences in both measured articular surface strains and rupture characteristics between the three categories of tissue suggest that there is a progressive reduction in the intrinsic strength of the intact surface layer of cartilage with both aging and proximity to site of fibrillation.

  4. Staged Management of a Ruptured Internal Mammary Artery Aneurysm

    PubMed Central

    Kwon, O Young; Kim, Gun Jik; Oh, Tak Hyuk; Lee, Young Ok; Lee, Sang Cjeol; Cho, Jun Yong

    2016-01-01

    The rupture of an internal mammary artery (IMA) aneurysm in a patient with type 1 neurofibromatosis (NF-1) is a rare but life-threatening complication requiring emergency management. A 50-year-old man with NF-1 was transferred to the emergency department of Kyungpook National University Hospital, where an IMA aneurysmal rupture and hemothorax were diagnosed and drained. The IMA aneurysmal rupture and hemothorax were successfully repaired by staged management combining endovascular treatment and subsequent video-assisted thoracoscopic surgery (VATS). The patient required cardiopulmonary cerebral resuscitation, the staged management of coil embolization, and a subsequent VATS procedure. This staged approach may be an effective therapeutic strategy in cases of IMA aneurysmal rupture. PMID:27066438

  5. Endobronchial Cartilage Rupture: A Rare Cause of Lobar Collapse

    PubMed Central

    Siddiqui, Nauman; Javaid, Toseef

    2016-01-01

    Endobronchial cartilage rupture is a rare clinical condition, which can present in patients with severe emphysema with sudden onset shortness of breath. We present a case of a 62-year-old male who presented to our emergency department with sudden onset shortness of breath. Chest X-ray showed lung hyperinflation and a right lung field vague small density. Chest Computed Tomography confirmed the presence of right middle lobe collapse. Bronchoscopy revealed partial right middle lobe atelectasis and an endobronchial cartilage rupture. Endobronchial cartilage rupture is a rare condition that can present as sudden onset shortness of breath due to lobar collapse in patients with emphysema and can be triggered by cough. Bronchoscopic findings include finding a collapsed lung lobe and a visible ruptured endobronchial cartilage. A high index of suspicion, chest imaging, and early bronchoscopy can aid in the diagnosis and help prevent complications. PMID:27525149

  6. Automatic rupture of unused intraport catheter. Case report.

    PubMed

    Pappas, Paris; Dalianis, Nikolaos; Filippou, Dimitrios K; Condiis, Nicolas; Rizos, Spiros; Skandalakis, Panagiotis

    2007-01-01

    Totally Implantable Central Venous Access Devices (Intraports) are commonly used in cancer patients to administer chemotherapy or parenteral nutrition. These devices are placed by Seldinger technique. We report an unusual case of intraport catheter rupture before the use of the device. The ruptured part of the catheter migrated into the left pulmonary vein via right ventricle. The ruptured part was removed by means of interventional radiology before causing any problems to the patient. All the reported ruptures of port catheters refer to port devices that had been used to administer chemotherapy, fluids, or parenteral nutrition. The unique feature of this case is that the catheter had not been used at all. It is of great interest also the removal of the broken part from the pulmonary vein.

  7. Delayed aortic rupture resulting from postoperative superficial sternal wound infection

    PubMed Central

    Kim, Su Wan; Chang, Jee Won

    2016-01-01

    While deep sternal wound infection (DSWI) after cardiac surgery is a significant contributor to patient morbidity and mortality, superficial sternal wound infection (SSWI) mostly has a benign course. We report a mortality case of aortic rupture resulting from SSWI after cardiac surgery. A 50-year-old male underwent an aortic valve replacement (AVR). Three months after the valve operation, he presented with severe dyspnea, which had never before been observed, and chest computed tomography revealed an ascending aortic rupture with large hematoma compressing the main pulmonary artery. We performed an emergent operation for aortic rupture that possibly originated from the SSWI. Postoperatively, the patient died of hypovolemic shock due to recurrent aortic rupture despite efforts to resuscitate him. PMID:27499988

  8. Cocaine Use and Splenic Rupture: A Rare Yet Serious Association

    PubMed Central

    Karthik, Nishrutha; Gnanapandithan, Karthik

    2016-01-01

    Cocaine abuse is frequent in patients visiting the emergency department. The knowledge of the cardiovascular complications of cocaine is excellent among physicians. However the awareness regarding its abdominal complications, the most important of which include gastroduodenal perforation, bowel ischemia and splenic rupture is less adequate. We report a 58-year-old with cocaine use who presents with upper abdominal pain and a rapidly worsening clinical status. He was found to have atraumatic splenic rupture causing a hemoperitoneum that was managed by intervention radiology guided splenic artery embolization. Splenic hemorrhage and rupture need timely recognition, as they are difficult to diagnose clinically and can be potentially fatal. In the encounter of patients with cocaine use who present with chest or upper abdominal pain, clinicians should consider imaging to look for splenic rupture as it is often masked or overlooked due to the complicated clinical picture. PMID:27777711

  9. Ruptured chordae tendineae in acromegaly. An autopsy case.

    PubMed

    Kaku, T; Nakashima, Y; Ichiyasu, H; Soejima, M; Baba, K; Kuroiwa, A

    1991-07-01

    A 57-year-old woman with acromegaly associated with mitral chordal rupture is reported. She was noted to have abnormal development in the size of her hands and feet in childhood. She occasionally suffered from shortness of breath on exertion and nocturnal dyspnea for several years, and was diagnosed and treated as having congestive heart failure due to valvular heart disease. On admission to our hospital, chordal rupture was suspected on the basis of M-mode and two-dimensional echocardiography. Seven years after discharge, she died of congestive heart failure. On autopsy, the heart weight and ventricular wall thickness were increased. Rupture of the posterior chordae was confirmed, but evidence of an old myocardial infarction was not found. There was severe interstitial fibrosis in the left ventricular wall. A possible etiology of the chordal rupture in this case was thought to be the excessive stretching caused by the disproportional visceromegaly of the heart.

  10. Endobronchial Cartilage Rupture: A Rare Cause of Lobar Collapse.

    PubMed

    Dasa, Osama; Siddiqui, Nauman; Ruzieh, Mohammed; Javaid, Toseef

    2016-01-01

    Endobronchial cartilage rupture is a rare clinical condition, which can present in patients with severe emphysema with sudden onset shortness of breath. We present a case of a 62-year-old male who presented to our emergency department with sudden onset shortness of breath. Chest X-ray showed lung hyperinflation and a right lung field vague small density. Chest Computed Tomography confirmed the presence of right middle lobe collapse. Bronchoscopy revealed partial right middle lobe atelectasis and an endobronchial cartilage rupture. Endobronchial cartilage rupture is a rare condition that can present as sudden onset shortness of breath due to lobar collapse in patients with emphysema and can be triggered by cough. Bronchoscopic findings include finding a collapsed lung lobe and a visible ruptured endobronchial cartilage. A high index of suspicion, chest imaging, and early bronchoscopy can aid in the diagnosis and help prevent complications. PMID:27525149

  11. Acute Bilateral Traumatic Achilles Tendon Rupture – A Rare Presentation

    PubMed Central

    Jhaveri, Maulik; Golwala, Paresh; Merh, Aditya; Patel, Amit

    2016-01-01

    The Achilles tendon is the strongest tendon in the body, which is commonly ruptured in male athletes. Bilateral rupture of the Achilles tendon is a rare condition with very few reported cases in the literature. It poses a challenge in management, and hence, we report a case with traumatic bilateral Achilles tendon rupture in a young male patient and its management. One side was treated conservatively as the rupture was partial and the other side, which had a complete tear, was operated. At nine months follow-up, the patient has had a satisfactory result and is now bearing full weight without any problems. We suggest this method of treatment to be worthwhile for this unusual entity. PMID:27588227

  12. Etiology and pathophysiology of tendon ruptures in sports.

    PubMed

    Kannus, P; Natri, A

    1997-04-01

    Of all spontaneous tendon ruptures, complete Achilles tendon tears are most closely associated with sports activities (1-3). Schönbauer (3) reported that 75% of all ruptures of the Achilles tendon are related to sports. In Plecko & Passl (2) the number was 60%. In our material of 430 cases, the number of sports-related Achilles ruptures was very similar (62%), while only 2% of ruptures of other tendons were sports-related (P < 0.001) (1). Also, the majority of Achilles reruptures occurred in sports. The ruptures occurred most often in soccer (34%), track and field (16%) and basketball (14%). The distribution of Achilles ruptures according to different sports varies considerably from country to country, according to the national sport traditions. For example, in northern and middle Europe, soccer, tennis, track and field, indoor ball games, downhill skiing, and gymnastics are the most common; and in North America, football, basketball, baseball, tennis and downhill skiing dominate the statistics (1, 2, 4). In sports, some Achilles ruptures are not spontaneous or degeneration-induced but may occur as a consequence of the remarkably high forces that are involved in the performance (2). Ruptures in the high jump or triple jump are good examples. In such cases, failure in the neuromuscular protective mechanisms due to fatigue or disturbed co-ordination can frequently be found. The spontaneous complete rupture of the supraspinatus tendon of the rotator cuff does not occur very frequently in sports. Those sports that include high-energy throwing movements, such as American and Finnish baseball, American football, rugby and discuss and javelin throwing, may, however, produce this injury. Partial tears and inflammations of the rotator cuff complex are much more frequent in throwing sports. The complete rupture of the proximal long head of the biceps brachii tendon is rare among competitive and recreational athletes. In our material, under 2% of these ruptures were

  13. Risk Stratification of Patients with Peripheral Arterial Disease and Abdominal Aortic Aneurysm Using Aortic Augmentation Index

    PubMed Central

    Beckmann, Marianne; Husmann, Marc

    2015-01-01

    Background Central augmentation index (cAIx) is an indicator for vascular stiffness. Obstructive and aneurysmatic vascular disease can affect pulse wave propagation and reflection, causing changes in central aortic pressures. Aim To assess and compare cAIx in patients with peripheral arterial disease (PAD) and / or abdominal aortic aneurysm (AAA). Methods cAIx was assessed by radial applanation tonometry (Sphygmocor) in a total of 184 patients at a tertiary referral centre. Patients were grouped as having PAD only, AAA only, or both AAA and PAD. Differences in cAIx measurements between the three patient groups were tested by non-parametric tests and stepwise multivariate linear regression analysis to investigate associations with obstructive or aneurysmatic patterns of vascular disease. Results In the study sample of 184 patients, 130 had PAD only, 20 had AAA only, and 34 patients had both AAA and PAD. Mean cAIx (%) was 30.5 ± 8.2 across all patients. It was significantly higher in females (35.2 ± 6.1, n = 55) than males (28.4 ± 8.2, n = 129), and significantly higher in patients over 80 years of age (34.4 ± 6.9, n = 22) than in those under 80 years (30.0 ± 8.2, n = 162). Intergroup comparison revealed a significant difference in cAIx between the three patient groups (AAA: 27.3 ± 9.5; PAD: 31.4 ± 7.8; AAA & PAD: 28.8 ± 8.5). cAIx was significantly lower in patients with AAA, higher in patients with both AAA and PAD, and highest in patients with PAD only (beta = 0.21, p = 0.006). Conclusion Non-invasive assessment of arterial stiffness in high-risk patients indicates that cAIx differs according to the pattern of vascular disease. Measurements revealed significantly higher cAIx values for patients with obstructive peripheral arterial disease than for patients with aneurysmatic disease. PMID:26452151

  14. Fall of blood ionized calcium on watching a provocative TV program and its prevention by active absorbable algal calcium (AAA Ca).

    PubMed

    Fujita, T; Ohgitani, S; Nomura, M

    1999-01-01

    In December 1997, more than 680 children developed convulsive seizures while watching a notorious audiovisually provocative TV program, "Pocket Monster." Emotional stimulation via hyperventilation may cause respiratory alkalosis, fall of blood ionized calcium (Ca), and sensitization of the nervous system to excessive emotional stress. A study was therefore undertaken to follow the changes of blood ionized Ca in eight healthy volunteers after watching the "Pocket Monster" and also a quiet program, "Classical Music," as a control for 20min from 4 P.M. Although neither marked hyperventilation nor convulsions developed in any of these adult volunteers, blood ionized Ca showed a significantly more pronounced fall during and after watching "Pocket Monster," and their plasma intact parathyroid hormone (iPTH) was significantly higher 120min after the beginning of "Pocket Monster" than the "Classical Music" program. Plasma total Ca, pH, and albumin were free of detectable changes. Ingestion of 600mg Ca as active absorbable algal Ca (AAA Ca) with high bioavailability completely prevented the fall of ionized Ca and suppressed iPTH. Plama osteocalcin was also significantly suppressed after ingestion of AAA Ca. It may be worthwhile to ingest AAA Ca before anticipated emotional stress such as watching a provocative TV program to prevent possible neuromuscular instability. PMID:10340641

  15. Elements in nucleotide sensing and hydrolysis of the AAA+ disaggregation machine ClpB: a structure-based mechanistic dissection of a molecular motor

    SciTech Connect

    Zeymer, Cathleen Barends, Thomas R. M.; Werbeck, Nicolas D.; Schlichting, Ilme; Reinstein, Jochen

    2014-02-01

    High-resolution crystal structures together with mutational analysis and transient kinetics experiments were utilized to understand nucleotide sensing and the regulation of the ATPase cycle in an AAA+ molecular motor. ATPases of the AAA+ superfamily are large oligomeric molecular machines that remodel their substrates by converting the energy from ATP hydrolysis into mechanical force. This study focuses on the molecular chaperone ClpB, the bacterial homologue of Hsp104, which reactivates aggregated proteins under cellular stress conditions. Based on high-resolution crystal structures in different nucleotide states, mutational analysis and nucleotide-binding kinetics experiments, the ATPase cycle of the C-terminal nucleotide-binding domain (NBD2), one of the motor subunits of this AAA+ disaggregation machine, is dissected mechanistically. The results provide insights into nucleotide sensing, explaining how the conserved sensor 2 motif contributes to the discrimination between ADP and ATP binding. Furthermore, the role of a conserved active-site arginine (Arg621), which controls binding of the essential Mg{sup 2+} ion, is described. Finally, a hypothesis is presented as to how the ATPase activity is regulated by a conformational switch that involves the essential Walker A lysine. In the proposed model, an unusual side-chain conformation of this highly conserved residue stabilizes a catalytically inactive state, thereby avoiding unnecessary ATP hydrolysis.

  16. Substrate delivery by the AAA+ ClpX and ClpC1 unfoldases activates the mycobacterial ClpP1P2 peptidase

    PubMed Central

    Schmitz, Karl R.; Sauer, Robert T.

    2014-01-01

    Summary Mycobacterial Clp-family proteases function via collaboration of the heteromeric ClpP1P2 peptidase with a AAA+ partner, ClpX or ClpC1. These enzymes are essential for M. tuberculosis viability and are validated antibacterial drug targets, but the requirements for assembly and regulation of functional proteolytic complexes are poorly understood. Here, we report the reconstitution of protein degradation by mycobacterial Clp proteases in vitro and describe novel features of these enzymes that distinguish them from orthologs in other bacteria. Both ClpX and ClpC1 catalyze ATP-dependent unfolding and degradation of native protein substrates in conjunction with ClpP1P2, but neither mediates protein degradation with just ClpP1 or ClpP2. ClpP1P2 alone has negligible peptidase activity, but is strongly stimulated by translocation of protein substrates into ClpP1P2 by either AAA+ partner. Interestingly, our results support a model in which both binding of a AAA+ partner and protein-substrate delivery are required to stabilize active ClpP1P2. Our model has implications for therapeutically targeting ClpP1P2 in dormant M. tuberculosis, and our reconstituted systems should facilitate identification of novel Clp protease inhibitors and activators. PMID:24976069

  17. FY05 LDRD Fianl Report Investigation of AAA+ protein machines that participate in DNA replication, recombination, and in response to DNA damage LDRD Project Tracking Code: 04-LW-049

    SciTech Connect

    Sawicka, D; de Carvalho-Kavanagh, M S; Barsky, D; Venclovas, C

    2006-12-04

    The AAA+ proteins are remarkable macromolecules that are able to self-assemble into nanoscale machines. These protein machines play critical roles in many cellular processes, including the processes that manage a cell's genetic material, but the mechanism at the molecular level has remained elusive. We applied computational molecular modeling, combined with advanced sequence analysis and available biochemical and genetic data, to structurally characterize eukaryotic AAA+ proteins and the protein machines they form. With these models we have examined intermolecular interactions in three-dimensions (3D), including both interactions between the components of the AAA+ complexes and the interactions of these protein machines with their partners. These computational studies have provided new insights into the molecular structure and the mechanism of action for AAA+ protein machines, thereby facilitating a deeper understanding of processes involved in DNA metabolism.

  18. Retrograde approach for closure of ruptured sinus of Valsalva.

    PubMed

    Jayaranganath, M; Subramanian, Anand; Manjunath, Cholenahally Nanjappa

    2010-07-01

    Though ruptured sinuses of Valsalva have been traditionally managed surgically, they are amenable to transcatheter closure. Various devices have been used for closure of these defects. We describe a novel technique of closure of a ruptured right sinus of Valsalva into the right ventricular outflow tract. A muscular ventricular septal defect occluder was deployed retrogradely, without resorting to the usual antegrade technique involving formation of an arteriovenous loop. PMID:20603510

  19. Paraplegia due to Spinal Epidermoid Cyst Rupture at Asthma Attack

    PubMed Central

    Kim, Kweon Young; Kang, Jung Hun; Choi, Dae Woo; Lee, Min Hong

    2013-01-01

    Spinal epidermoid cyst is less than 1% of the entire spinal cord tumor and a rare tumor. It is a slowly proliferating benign tumor and can be a result of either congenital or acquired factors. In particular, reports of acute paraplegia due to spinal epidermoid cyst rupture are very rare. Since authors experienced paraplegia resulting from congenital spinal epidermoid cyst rupture during an asthma attack, it is reported with a review of literature. PMID:23705125

  20. Cohesive zone length of metagabbro at supershear rupture velocity

    NASA Astrophysics Data System (ADS)

    Fukuyama, Eiichi; Xu, Shiqing; Yamashita, Futoshi; Mizoguchi, Kazuo

    2016-06-01

    We investigated the shear strain field ahead of a supershear rupture. The strain array data along the sliding fault surfaces were obtained during the large-scale biaxial friction experiments at the National Research Institute for Earth Science and Disaster Resilience. These friction experiments were done using a pair of meter-scale metagabbro rock specimens whose simulated fault area was 1.5 m × 0.1 m. A 2.6-MPa normal stress was applied with loading velocity of 0.1 mm/s. Near-fault strain was measured by 32 two-component semiconductor strain gauges installed at an interval of 50 mm and 10 mm off the fault and recorded at an interval of 1 MHz. Many stick-slip events were observed in the experiments. We chose ten unilateral rupture events that propagated with supershear rupture velocity without preceding foreshocks. Focusing on the rupture front, stress concentration was observed and sharp stress drop occurred immediately inside the ruptured area. The temporal variation of strain array data is converted to the spatial variation of strain assuming a constant rupture velocity. We picked up the peak strain and zero-crossing strain locations to measure the cohesive zone length. By compiling the stick-slip event data, the cohesive zone length is about 50 mm although it scattered among the events. We could not see any systematic variation at the location but some dependence on the rupture velocity. The cohesive zone length decreases as the rupture velocity increases, especially larger than √{2} times the shear wave velocity. This feature is consistent with the theoretical prediction.

  1. Atraumatic splenic rupture after coagulopathy owing to a snakebite.

    PubMed

    Kang, Changwoo; Kim, Dong Hoon; Kim, Seong Chun; Kim, Dong Seob; Jeong, Chi-Young

    2014-09-01

    Among the many complications that may follow envenomation by some species of venomous snakes, coagulopathy is common and well known. However, hemoperitoneum induced by coagulopathy after a snakebite is rare. Atraumatic spontaneous splenic rupture is also an uncommon and life-threatening condition. Here, we report a case of presumptive envenomation by Gloydius spp. that resulted in atraumatic splenic rupture as a probable manifestation of coagulopathy, which has not been previously reported. PMID:24882658

  2. Softball injury causing haemoperitoneum due to ruptured Meckel's mesodiverticular band.

    PubMed

    Woodfield, Julie; Barnett, Mark; Shapkov, Peter

    2011-10-14

    A 16-year-old male sustained an intra-abdominal haemorrhage after diving for last base during a softball game. At laparotomy a ruptured patent mesodiverticular band supplying a large Meckel's diverticulum was found. Traumatic rupture of a mesodiverticular band leading to massive intra-abdominal haemorrhage is a rare event, and has never been reported as a single injury or in the context of a sport's injury.

  3. First report of splenic rupture following deep enteroscopy

    PubMed Central

    Girelli, Carlo Maria; Pometta, Roberta; Facciotto, Corinna; Mella, Roberto; Bernasconi, Giordano

    2016-01-01

    Splenic rupture is a rare complication of diagnostic and therapeutic gastrointestinal endoscopy procedures. Herein, we report for the first time a case of splenic rupture following therapeutic retrograde double-balloon enteroscopy, which occurred in an 85-year-old man who was treated for recurrent mid-intestinal bleeding that resulted from ileal angioectasia. This patient promptly underwent an operation and eventually recovered. PMID:27170840

  4. [Bilateral quadriceps rupture in a patient with osteogenesis imperfecta. A case report].

    PubMed

    Salcedo-Dueñas, Jesús Alejandro; Torres Castro, Carlos; Estrada Gómez, José Andrés; Algarín Reyes, José Antonio; Bello González, Alejandro

    2009-01-01

    We present the case of a 24-year-old patient with bilateral quadriceps rupture and history of type I congenital osteogenesis imperfecta diagnosed clinically and with ultrasound. Bilateral quadriceps tenoplasty was performed with an anterior approach and without any complications. The patient was discharged with bilateral neoprene knee-guards. The sutures were removed at the 21-day follow-up visit, rehabilitation was started at six weeks and the patient was doing well at the 2- and 3-month follow-up visits. Timely management and early rehabilitation contribute to decrease the risk of sequelae despite the poor functional prognosis.

  5. Synergy and interactions among biological pathways leading to preterm premature rupture of membranes.

    PubMed

    Lannon, Sophia M R; Vanderhoeven, Jeroen P; Eschenbach, David A; Gravett, Michael G; Adams Waldorf, Kristina M

    2014-10-01

    Preterm premature rupture of membranes (PPROM) occurs in 1% to 2% of births. Impact of PPROM is greatest in low- and middle-income countries where prematurity-related deaths are most common. Recent investigations identify cytokine and matrix metalloproteinase activation, oxidative stress, and apoptosis as primary pathways to PPROM. These biological processes are initiated by heterogeneous etiologies including infection/inflammation, placental bleeding, uterine overdistention, and genetic polymorphisms. We hypothesize that pathways to PPROM overlap and act synergistically to weaken membranes. We focus our discussion on membrane composition and strength, pathways linking risk factors to membrane weakening, and future research directions to reduce the global burden of PPROM.

  6. Intracranial hemorrhage from undetected aneurysmal rupture complicating transphenoidal pituitary adenoma resection.

    PubMed

    Rustagi, Tarun; Uy, Edilfavia Mae; Rai, Mridula; Kannan, Subramanian; Senatus, Patrick

    2011-08-01

    We report a case of a 39-year-old man who presented with a nonfunctioning pituitary macroadenoma which extended into the suprasellar region. He underwent a transcranial resection of the tumor followed eight months later by transsphenoidal surgery for the residual tumor. Postoperatively he developed massive subarachnoid and intraventricular hemorrhage. A cerebral angiogram revealed a leaking anterior communicating artery aneurysm which was not seen on the computed tomography angiography and magnetic resonance angiography before the surgery. Complications of transsphenoidal surgery, particularly vascular hemorrhagic complications, and risk of rupture of undetected aneurysms are discussed.

  7. The temporal distribution of seismic radiation during deep earthquake rupture

    USGS Publications Warehouse

    Houston, H.; Vidale, J.E.

    1994-01-01

    The time history of energy release during earthquakes illuminates the process of failure, which remains enigmatic for events deeper than about 100 kilometers. Stacks of teleseismic records from regional arrays for 122 intermediate (depths of 100 to 350 kilometers) and deep (depths of 350 to 700 kilometers) earthquakes show that the temporal pattern of short-period seismic radiation has a systematic variation with depth. On average, for intermediate depth events more radiation is released toward the beginning of the rupture than near the end, whereas for deep events radiation is released symmetrically over the duration of the event, with an abrupt beginning and end of rupture. These findings suggest a variation in the style of rupture related to decreasing fault heterogeneity with depth.The time history of energy release during earthquakes illuminates the process of failure, which remains enigmatic for events deeper than about 100 kilometers. Stacks of teleseismic records from regional arrays for 122 intermediate (depths of 100 to 350 kilometers) and deep (depths of 350 to 700 kilometers) earthquakes show that the temporal pattern of short-period seismic radiation has a systematic variation with depth. On average, for intermediate depth events more radiation is released toward the beginning of the rupture than near the end, whereas for deep events radiation is released symmetrically over the duration of the event, with an abrupt beginning and end of rupture. These findings suggest a variation in the style of rupture related to decreasing fault heterogeneity with depth.

  8. Limitations of rupture forecasting exposed by instantaneously triggered earthquake doublet

    NASA Astrophysics Data System (ADS)

    Nissen, E.; Elliott, J. R.; Sloan, R. A.; Craig, T. J.; Funning, G. J.; Hutko, A.; Parsons, B. E.; Wright, T. J.

    2016-04-01

    Earthquake hazard assessments and rupture forecasts are based on the potential length of seismic rupture and whether or not slip is arrested at fault segment boundaries. Such forecasts do not generally consider that one earthquake can trigger a second large event, near-instantaneously, at distances greater than a few kilometres. Here we present a geodetic and seismological analysis of a magnitude 7.1 intracontinental earthquake that occurred in Pakistan in 1997. We find that the earthquake, rather than a single event as hitherto assumed, was in fact an earthquake doublet: initial rupture on a shallow, blind reverse fault was followed just 19 s later by a second rupture on a separate reverse fault 50 km away. Slip on the second fault increased the total seismic moment by half, and doubled both the combined event duration and the area of maximum ground shaking. We infer that static Coulomb stresses at the initiation location of the second earthquake were probably reduced as a result of the first. Instead, we suggest that a dynamic triggering mechanism is likely, although the responsible seismic wave phase is unclear. Our results expose a flaw in earthquake rupture forecasts that disregard cascading, multiple-fault ruptures of this type.

  9. Reduction in the occurrence of uterine rupture in Central India.

    PubMed

    Chhabra, S; Bhagwat, N; Chakravorty, Anupama

    2002-01-01

    This study was carried out in the Department of Obstetrics and Gynaecology of the Mahatma Gandhi Institute of Medical Sciences, Sevagram in Central India. In the 12 years between 1989 and 2000 a total of 16 cases of ruptured uterus were managed, the incidence of rupture of the pregnant uterus being 0.62 per 1000 births. One-quarter of the cases occurred between 1983 and 1988. No teenager or elderly woman (over 40) or grandmultipara sustained a uterine rupture. Four women had a rupture of a previous scar. In five rupture had occurred in association with malpresentations, one was a case of hydrocephalus, two had a morbidly adherent placenta praevia and four had a normal presentation, with lack of progress in labour. Two of these 16 women had twins. One had come with a retained second twin with transverse lie and the other was a booked case with multiple problems, including a previous caesarean section, present twin pregnancy and placenta praevia accreta and she died. This was the only maternal death. Perinatal mortality was 77.77% compared to 5.88% maternal and 100% perinatal mortality in the cases reported previously between 83 and 88, from the same institution. Overall, there is some improvement in perinatal survival and one-quarter incidence of rupture of the pregnant uterus.

  10. Bilateral renal rupture in a patient on hemodialysis.

    PubMed

    Carlson, Chris C; Holsten, Steve J; Grandas, Oscar H

    2003-06-01

    This is a case presentation and discussion of a dialysis patient who presented to the surgical service with abdominal pain, hypotension, and tachycardia and in extremis who was found to have a contained retroperitoneal hematoma after rupture of his left kidney. Six months after an uneventful nephrectomy and postoperative recovery he again presented with hypotension and anemia and was found to have a contralateral retroperitoneal hematoma consistent with renal hemorrhage. After unsuccessful angioembolization, the patient underwent a right nephrectomy and recovered without sequelae. Bilateral spontaneous renal rupture is a rare event documented by only a few anecdotal reports in the literature and usually associated with acquired cystic kidney disease. Rupture of renal cysts is relatively common in renal cystic disease but usually presents as asymptomatic hematuria or flank pain. Trauma is the most common cause of renal rupture, but other causes of spontaneous renal rupture are rare and include polyarteritis nodosa and urothelial carcinoma. The diagnosis of acute abdominal pain in the dialysis patient is a challenging differential. While a rare complication the diagnosis of spontaneous renal rupture should not be excluded in a patient presenting with abdominal pain, hypotension, and anemia.

  11. Ground-motion signature of dynamic ruptures on rough faults

    NASA Astrophysics Data System (ADS)

    Mai, P. Martin; Galis, Martin; Thingbaijam, Kiran K. S.; Vyas, Jagdish C.

    2016-04-01

    Natural earthquakes occur on faults characterized by large-scale segmentation and small-scale roughness. This multi-scale geometrical complexity controls the dynamic rupture process, and hence strongly affects the radiated seismic waves and near-field shaking. For a fault system with given segmentation, the question arises what are the conditions for producing large-magnitude multi-segment ruptures, as opposed to smaller single-segment events. Similarly, for variable degrees of roughness, ruptures may be arrested prematurely or may break the entire fault. In addition, fault roughness induces rupture incoherence that determines the level of high-frequency radiation. Using HPC-enabled dynamic-rupture simulations, we generate physically self-consistent rough-fault earthquake scenarios (M~6.8) and their associated near-source seismic radiation. Because these computations are too expensive to be conducted routinely for simulation-based seismic hazard assessment, we thrive to develop an effective pseudo-dynamic source characterization that produces (almost) the same ground-motion characteristics. Therefore, we examine how variable degrees of fault roughness affect rupture properties and the seismic wavefield, and develop a planar-fault kinematic source representation that emulates the observed dynamic behaviour. We propose an effective workflow for improved pseudo-dynamic source modelling that incorporates rough-fault effects and its associated high-frequency radiation in broadband ground-motion computation for simulation-based seismic hazard assessment.

  12. Dynamic rupture modeling with laboratory-derived constitutive relations

    USGS Publications Warehouse

    Okubo, P.G.

    1989-01-01

    A laboratory-derived state variable friction constitutive relation is used in the numerical simulation of the dynamic growth of an in-plane or mode II shear crack. According to this formulation, originally presented by J.H. Dieterich, frictional resistance varies with the logarithm of the slip rate and with the logarithm of the frictional state variable as identified by A.L. Ruina. Under conditions of steady sliding, the state variable is proportional to (slip rate)-1. Following suddenly introduced increases in slip rate, the rate and state dependencies combine to produce behavior which resembles slip weakening. When rupture nucleation is artificially forced at fixed rupture velocity, rupture models calculated with the state variable friction in a uniformly distributed initial stress field closely resemble earlier rupture models calculated with a slip weakening fault constitutive relation. Model calculations suggest that dynamic rupture following a state variable friction relation is similar to that following a simpler fault slip weakening law. However, when modeling the full cycle of fault motions, rate-dependent frictional responses included in the state variable formulation are important at low slip rates associated with rupture nucleation. -from Author

  13. Association of Oversized Tracheal Tubes and Cuff Overinsufflation With Postintubation Tracheal Ruptures

    PubMed Central

    Sudhoff, Tobias H.; Seidl, Rainer O.; Estel, Barbara

    2015-01-01

    Objectives Postintubation tracheal ruptures (PTR) are rare but cause severe complications. Our objective was to investigate the tracheal pattern of injury resulting from cuff inflation of the tracheal tube, to study the two main factors responsible for PTR (cuff overinsufflation and inapplicable tube sizes), and to explain the context, why small women are particularly susceptible to PTR. Methods Experimental study performed on 28 fresh human laryngotracheal specimens (16 males, 12 females) within 24 hours post autopsy. Artificial ventilation was simulated by using an underwater construction and a standard tracheal tube. Tube sizes were selected according to our previously published nomogram. Tracheal lesions were detected visually and tracheal diameters measured. The influence of body size, sex difference and appropriate tube size were investigated according to patient height. Results In all 28 cases, the typical tracheal lesion pattern was a longitudinal median rupture of the posterior trachea. Appropriate tube sizes according to body size caused PTR with significantly higher cuff pressure when compared with oversized tubes. An increased risk of PTR was found in shorter patients, when oversized tubes were used. Sex difference did not have any significant influence. Conclusion This experimental model provides information about tracheal patterns in PTR for the first time. The model confirms by experiment the observations of case series in PTR patients, and therefore emphasizes the importance of correct tube size selection according to patient height. This minimizes the risk of PTR, especially in shorter patients, who have an increased risk of PTR when oversized tubes are used. PMID:26622963

  14. Right ventricular free wall dissection as a rupture tract in left ventricular rupture during acute myocardial infarction.

    PubMed

    Takada, Aya; Saito, Kazuyuki; Murai, Tatsuya; Kurosaki, Kunihiko; Kurihara, Katsuyoshi; Hamamatsu, Akihiko

    2015-11-01

    Three rare cases of cardiac rupture with right ventricular wall dissection during acute myocardial infarction (AMI) were reported. The cases comprised 2% among our 148 previously reported postinfarction cardiac ruptures with sudden death. The dissections occurred in hearts with biventricular inferior wall AMI and developed between the superficial layers and the deeper layers of inferior wall of the right ventricle. All had an endocardial tear at the basal septum where it meets the inferior free wall of the left ventricle, and had an epicardial tear on the middle inferior wall of the right ventricle. Based on the evidence of the ages of the thrombi of the rupture tracts, delayed epicardial rupture was found besides that soon after the right ventricular dissection. PMID:26594003

  15. Ruptured Juxtarenal Abdominal Aortic Aneurysm Treated With a Fenestrated EVAR Graft Intended for a Different Patient.

    PubMed

    Al-Jundi, Wissam; Elboushi, Amro; Lees, Tim; Williams, Robin

    2016-08-01

    Treatment of juxtarenal abdominal aortic aneurysms (AAAs) remains challenging. A 79-year-old male who had infrarenal endovascular repair of abdominal aortic aneurysm (EVAR) 13 years previously presented with leaking juxtarenal AAA. Emergency fenestrated EVAR (FEVAR) was performed utilizing a stent graft designed and built for a different patient. Despite the need to embolize the celiac artery prior to covering it with the stent graft in order to achieve adequate proximal seal, the patient had uneventful recovery. PMID:27334480

  16. Labor induction in the patient with preterm premature rupture of membranes.

    PubMed

    Packard, Roger Everett; Mackeen, Awathif Dhanya

    2015-10-01

    Preterm premature rupture of membranes (PPROM) affects up to one-third of all preterm births and confers serious maternal risks, including intra-amniotic infection, and an increased risk of neonatal complications, including respiratory distress and intraventricular hemorrhage. Management of PPROM is a highly individualized process that requires an accurate determination of gestational age and causal factors, as well as the balancing of maternal and fetal risks. In this review of the existing literature on induction of labor in PPROM, we examine the differences in appropriate management of patients with early (32 weeks 0 days to 33 weeks 6 days) and near term (34 weeks 0 days to 36 weeks 6 days) PPROM, and compare the safety and efficacy of available treatment options. This review of previous research findings provides general guidelines for clinical decision making and highlights the need for future research on management of PPROM.

  17. A model to forecast magma chamber rupture

    NASA Astrophysics Data System (ADS)

    Browning, John; Drymoni, Kyriaki; Gudmundsson, Agust

    2016-04-01

    An understanding of the amount of magma available to supply any given eruption is useful for determining the potential eruption magnitude and duration. Geodetic measurements and inversion techniques are often used to constrain volume changes within magma chambers, as well as constrain location and depth, but such models are incapable of calculating total magma storage. For example, during the 2012 unrest period at Santorini volcano, approximately 0.021 km3 of new magma entered a shallow chamber residing at around 4 km below the surface. This type of event is not unusual, and is in fact a necessary condition for the formation of a long-lived shallow chamber. The period of unrest ended without culminating in eruption, i.e the amount of magma which entered the chamber was insufficient to break the chamber and force magma further towards the surface. Using continuum-mechanics and fracture-mechanics principles, we present a model to calculate the amount of magma contained at shallow depth beneath active volcanoes. Here we discuss our model in the context of Santorini volcano, Greece. We demonstrate through structural analysis of dykes exposed within the Santorini caldera, previously published data on the volume of recent eruptions, and geodetic measurements of the 2011-2012 unrest period, that the measured 0.02% increase in volume of Santorini's shallow magma chamber was associated with magmatic excess pressure increase of around 1.1 MPa. This excess pressure was high enough to bring the chamber roof close to rupture and dyke injection. For volcanoes with known typical extrusion and intrusion (dyke) volumes, the new methodology presented here makes it possible to forecast the conditions for magma-chamber failure and dyke injection at any geodetically well-monitored volcano.

  18. Successful endovascular treatment of a ruptured superior mesenteric artery in a patient with Ehlers‒Danlos syndrome.

    PubMed

    Yasuda, Shota; Imoto, Kiyotaka; Uchida, Keiji; Machida, Daisuke; Yanagi, Hiromasa; Sugiura, Tadahisa; Kurosawa, Kenji; Masuda, Munetaka

    2013-10-01

    The purpose of this study was to describe covered-stent treatment of a ruptured dissection of the superior mesenteric artery (SMA) in a patient with Ehlers‒Danlos syndrome. The patient was a 13-year-old girl initially presenting with abdominal pain. Dissection and rupture of the SMA were diagnosed on detailed examination. Conservative treatment was performed initially because open surgery was considered high risk. However, the abdominal pain recurred, and we decided to perform endovascular therapy. A coronary artery covered stent was placed in the true lumen to close the entry site of the dissection. The false lumen was obliterated using a post-dilation technique, completing treatment of the rupture. The patient recovered uneventfully after surgery. Classic-type Ehlers‒Danlos syndrome was diagnosed on the basis of physical findings and genetic analysis. The stent has remained adequately patent as of 2 years after surgery. This case report shows that dissection and rupture of the SMA can be treated successfully using a covered coronary artery stent in a patient with Ehlers‒Danlos syndrome. PMID:23891251

  19. Spontaneous Splenic Rupture Following Intravenous Thrombolysis with Alteplase Applied as Stroke Therapy – Case Report and Review of Literature

    PubMed Central

    Aleksic-Shihabi, Anka; Jadrijevic, Eni; Milekic, Nina; Bulicic, Ana Repic; Titlic, Marina; Suljic, Enra

    2016-01-01

    Introduction: Stroke is a medical emergency in neurology, and is one of the leading causes of death nowadays. At a recent time, a therapeutic method used in adequate conditions is thrombolysis, a treatment of an emerging clot in the brain vascular system by alteplase. The application of alteplase also has a high risk of life threatening conditions. Case report: This is a brief report of a case with thrombolysis complication which manifested as a spleen rupture. PMID:26980937

  20. Experimental verification of the Acuros XB and AAA dose calculation adjacent to heterogeneous media for IMRT and RapidArc of nasopharygeal carcinoma

    SciTech Connect

    Kan, Monica W. K.; Leung, Lucullus H. T.; So, Ronald W. K.; Yu, Peter K. N.

    2013-03-15

    Purpose: To compare the doses calculated by the Acuros XB (AXB) algorithm and analytical anisotropic algorithm (AAA) with experimentally measured data adjacent to and within heterogeneous medium using intensity modulated radiation therapy (IMRT) and RapidArc{sup Registered-Sign} (RA) volumetric arc therapy plans for nasopharygeal carcinoma (NPC). Methods: Two-dimensional dose distribution immediately adjacent to both air and bone inserts of a rectangular tissue equivalent phantom irradiated using IMRT and RA plans for NPC cases were measured with GafChromic{sup Registered-Sign} EBT3 films. Doses near and within the nasopharygeal (NP) region of an anthropomorphic phantom containing heterogeneous medium were also measured with thermoluminescent dosimeters (TLD) and EBT3 films. The measured data were then compared with the data calculated by AAA and AXB. For AXB, dose calculations were performed using both dose-to-medium (AXB{sub Dm}) and dose-to-water (AXB{sub Dw}) options. Furthermore, target dose differences between AAA and AXB were analyzed for the corresponding real patients. The comparison of real patient plans was performed by stratifying the targets into components of different densities, including tissue, bone, and air. Results: For the verification of planar dose distribution adjacent to air and bone using the rectangular phantom, the percentages of pixels that passed the gamma analysis with the {+-} 3%/3mm criteria were 98.7%, 99.5%, and 97.7% on the axial plane for AAA, AXB{sub Dm}, and AXB{sub Dw}, respectively, averaged over all IMRT and RA plans, while they were 97.6%, 98.2%, and 97.7%, respectively, on the coronal plane. For the verification of planar dose distribution within the NP region of the anthropomorphic phantom, the percentages of pixels that passed the gamma analysis with the {+-} 3%/3mm criteria were 95.1%, 91.3%, and 99.0% for AAA, AXB{sub Dm}, and AXB{sub Dw}, respectively, averaged over all IMRT and RA plans. Within the NP region where