Computer simulations of colloidal gels: how hindered particle rotation affects structure and rheology.

The effects of particle roughness and short-ranged non-central forces on colloidal gels are studied using computer simulations in which particles experience a sinusoidal variation in energy as they rotate. The number of minima n and energy scale K are the key parameters; for large K and n, particle rotation is strongly hindered, but for small K and n particle rotation is nearly free. A series of systems are simulated and characterized using fractal dimensions, structure factors, coordination number distributions, bond-angle distributions and linear rheology. When particles rotate easily, clusters restructure to favor dense packings. This leads to longer gelation times and gels with strand-like morphology. The elastic moduli of such gels scale as G'∝ω0.5 at high shear frequencies ω. In contrast, hindered particle rotation inhibits restructuring and leads to rapid gelation and diffuse morphology. Such gels are stiffer, with G'∝ω0.35. The viscous moduli G'' in the low-barrier and high-barrier regimes scale according to exponents 0.53 and 0.5, respectively. The crossover frequency between elastic and viscous behaviors generally increases with the barrier to rotation. These findings agree qualitatively with some recent experiments on heterogeneously-surface particles and with studies of DLCA-type gels and gels of smooth spheres.

Multimodal endovascular palliation for femoral arterial blowout in the setting of metastatic vulvar carcinoma.

BACKGROUND: Vascular blowout syndrome is a well-known, life-threatening condition complicating advanced-stage head and neck malignancies but has rarely been reported in the gynecologic oncology realm in association with the femoral circulation. A 50-year-old woman with metastatic vulvar squamous cell carcinoma presented with left threatened femoral arterial blowout, secondary to an exophytic neoplastic mass originating from the left inguinal lymph nodes. METHODS: Bland embolization of the tumor as well as 3 vessel covered stent revascularization was successfully performed with excellent tumor devascularization and reinstitution of arterial integrity. RESULTS: Successful devascularization of the tumor, with no non-target embolization was achieved, with excellent apposition and deployment of 3 covered stents in the femoral artery bifurcation. CONCLUSION: We present a unique case of threatened femoral artery blowout syndrome in the setting of metastatic vulvar carcinoma requiring various endovascular techniques for palliation. These endovascular techniques can be invaluable in minimally invasive palliation of advanced stage neoplasms abutting the iliofemoral circulation.

Cdc42 controls vascular network assembly through protein kinase Cι during embryonic vasculogenesis.

OBJECTIVE: The goal of this study was to determine the role of Cdc42 in embryonic vasculogenesis and the underlying mechanisms. METHODS AND RESULTS: By using genetically modified mouse embryonic stem (ES) cells, we demonstrate that ablation of the Rho GTPase Cdc42 blocks vascular network assembly during embryoid body (EB) vasculogenesis without affecting endothelial lineage differentiation. Reexpression of Cdc42 in mutant EBs rescues the mutant phenotype, establishing an essential role for Cdc42 in vasculogenesis. Chimeric analysis revealed that the vascular phenotype is caused by inactivation of Cdc42 in endothelial cells rather than surrounding cells. Endothelial cells isolated from Cdc42-null EBs are defective in directional migration and network assembly. In addition, activation of atypical protein kinase Cι (PKCι) is abolished in Cdc42-null endothelial cells, and PKCι ablation phenocopies the vascular abnormalities of the Cdc42-null EBs. Moreover, the inhibitory phosphorylation of glycogen synthase kinase-3ß (GSK-3ß) at Ser9 depends on Cdc42 and PKCι, and expression of kinase-dead GSK-3ß in Cdc42-null EBs promotes the formation of linear endothelial segments without branches. These results suggest that PKCι and GSK-3ß are downstream effectors of Cdc42 during vascular morphogenesis. CONCLUSIONS: Cdc42 controls vascular network assembly but not endothelial lineage differentiation by activating PKCι during embryonic vasculogenesis.

Use of Cervid Serosurveys to Monitor Eastern Equine Encephalitis Virus Activity in Northern New England, United States, 2009-2017.

Vertebrate surveillance for eastern equine encephalitis virus (EEEV) activity usually focuses on three types of vertebrates: horses, passerine birds, and sentinel chicken flocks. However, there is a variety of wild vertebrates that are exposed to EEEV infections and can be used to track EEEV activity. In 2009, we initiated a pilot study in northern New England, United States, to evaluate the effectiveness of using wild cervids (free-ranging white-tailed deer and moose) as spatial sentinels for EEEV activity. In Maine, New Hampshire, and Vermont during 2009-2017, we collected blood samples from hunter-harvested cervids at tagging stations and obtained harvest location information from hunters. U.S. Centers for Disease Control and Prevention processed the samples for EEEV antibodies using plaque reduction neutralization tests (PRNTs). We detected EEEV antibodies in 6 to 17% of cervid samples in the different states and mapped cervid EEEV seropositivity in northern New England. EEEV antibody-positive cervids were the first detections of EEEV activity in the state of Vermont, in northern Maine, and northern New Hampshire. Our key result was the detection of the antibodies in areas far outside the extent of documented wild bird, mosquito, human case, or veterinary case reports of EEEV activity in Maine, New Hampshire, and Vermont. These findings showed that cervid (deer and moose) serosurveys can be used to characterize the geographic extent of EEEV activity, especially in areas with low EEEV activity or with little or no EEEV surveillance. Cervid EEEV serosurveys can be a useful tool for mapping EEEV activity in areas of North America in addition to northern New England.

In-hospital and 30-day outcomes after tibioperoneal interventions in the US Medicare population with critical limb ischemia.

OBJECTIVES: Catheter-based revascularization has emerged as an alternative to surgical bypass for the tibioperoneal vessels. The purpose of this analysis was to describe the outcomes of tibial angioplasty interventions for critical limb ischemia (CLI) in the hospitalized Medicare population, to examine in-hospital complications, to define the 30-day readmission and mortality rates, and to assess secondary procedures performed in this population. METHODS: In-patients with CLI undergoing tibioperoneal angioplasty were identified using The Centers for Medicare & Medicaid Services in-patient claims for 2005 to 2007. In-hospital complications, mortality, 30-day secondary procedures, and 30-day rehospitalization after discharge were described. RESULTS: A total of 13,258 in-patients underwent tibioperoneal angioplasty (54.2% men; 75.7% white, 17.1% African American; 42.8% gangrene, 46.7% rest pain, 10.5% claudication) and 29.3% had a stent, 47.3% had femoral-popliteal angioplasty, and 20.1% had atherectomy during their initial procedure. Initial hospital complications included renal complications (8.1%), respiratory complications and pneumonia (5.1%), and cardiac complications with acute myocardial infarction (3.2%). Mortality in-hospital was 2.8% and at 30 days was 6.7%. Thirty-day rehospitalization rate was 29.6%. Thirty-day reinterventions included repeat angiogram (8.5%), repeat tibioperoneal angioplasty (3.2%), open bypass (2.1%), and lower extremity amputations (23.8%). Gangrene was the most frequent diagnosis at rehospitalization (13.5%). Patients with gangrene as an indication for tibioperoneal angioplasty were 1.8 times (95% confidence interval [CI], 1.56-2.10) as likely as patients with rest pain to be rehospitalized during 30 days after discharge. Among comorbidities, predictors of 30-day rehospitalization included chronic renal failure (odds ratio [OR], 1.4; 95% CI, 1.27-1.52), chronic pulmonary disease (OR, 1.1; 95% CI, 1.01-1.25), and congestive heart failure (CHF; OR, 1.1; 95% CI, 1.01-1.22). About one-quarter of patients (23.8%) within 30 days after their initial procedure underwent amputation at any level of the lower limb. CONCLUSION: Tibioperoneal angioplasty is associated with frequent in-hospital complications, an overall 30-day amputation rate of 23.8% for all procedures and indications, and a 30-day rehospitalization rate of almost 30%. Further detailed analysis of tibioperoneal intervention is essential to define best treatment strategies and to minimize complications and readmission rates.

Evaluating preventable adverse safety events after elective lower extremity procedures.

BACKGROUND: Improving patient safety has become a national priority. Patient safety indicators (PSIs) are validated tools to identify potentially preventable adverse events. No studies currently exist for evaluating lower extremity (LE) vascular procedures and the occurrence of PSIs. METHODS: The Nationwide Inpatient Sample (2003-2007) was queried for elective LE angioplasty (endo) and bypass (open). PSIs appropriate to surgery were analyzed by χ(2) and logistic regression analyses. RESULTS: A total of 226,501 LE interventions (104,491 endo; 122,010 open) were evaluated. The rate of developing any PSI was 7.74% (open) and 8.51% (endo), P < .0001. In the latter group, PSI9 (postoperative hemorrhage or hematoma) with the rate 4.74% was a predominant indicator that was associated with an almost three times greater likelihood of death in this group. PSI predictors included advanced age (odds ratio [OR], 1.64; 95% confidence interval [CI], 1.55-1.75 for oldest vs youngest patients), females (OR, 1.18; 95% CI, 1.13-1.22), blacks (OR, 1.10; 95% CI, 1.04-1.17), congestive heart failure (OR, 1.83; 95% CI, 1.72-1.96), diabetes mellitus (OR, 1.20; 95% CI, 1.12-1.28), renal failure (OR, 2.31; 95% CI, 2.14-2.50), hospital teaching status (OR, 1.21; 95% CI, 1.17-1.26), and larger hospitals (OR, 1.11; 95% CI, 1.05-1.17). PSI occurrence was associated with increased cost ($28,387 vs $13,278; P < .0001). CONCLUSIONS: Endovascular procedures were found to have lower mortality rates overall, but were found to have a greater number of safety events occur primarily due to bleeding complications in women and the elderly. PSIs were associated with advanced age, black race, and comorbidities. Adverse events added significant cost, occurred more frequently in teaching and large hospitals, and future organizational analysis may improve safety and reduce cost.

Comparing types of health insurance for children: a public option versus a private option.

BACKGROUND: Many states have expanded public health insurance programs for children, and further expansions were proposed in recent national reform initiatives; yet the expansion of public insurance plans and the inclusion of a public option in state insurance exchange programs sparked controversies and raised new questions with regard to the quality and adequacy of various insurance types. OBJECTIVES: We aimed to examine the comparative effectiveness of public versus private coverage on parental-reported children's access to health care in low-income and middle-income families. METHODS/PARTICIPANTS/MEASURES: We conducted secondary data analyses of the nationally representative Medical Expenditure Panel Survey, pooling years 2002 to 2006. We assessed univariate and multivariate associations between child's full-year insurance type and parental-reported unmet health care and preventive counseling needs among children in low-income (n=28,338) and middle-income families (n=13,160). RESULTS: Among children in families earning <200% of the federal poverty level, those with public insurance were significantly less likely to have no usual source of care compared with privately insured children (adjusted relative risk, 0.79; 95% confidence interval, 0.63-0.99). This was the only significant difference in 50 logistic regression models comparing unmet health care and preventive counseling needs among low-income and middle-income children with public versus private coverage. CONCLUSIONS: The striking similarities in reported rates of unmet needs among children with public versus private coverage in both low-income and middle-income groups suggest that a public children's insurance option may be equivalent to a private option in guaranteeing access to necessary health care services for all children.

Public health insurance in Oregon: underenrollment of eligible children and parental confusion about children's enrollment status.

OBJECTIVES: We identified characteristics of Oregon children who were eligible for the Oregon Health Plan (OHP), the state's combined Medicaid-Children's Health Insurance Program (CHIP), but were not enrolled in January 2005. We also assessed whether parents' confusion regarding their children's status affected nonenrollment. METHODS: We conducted cross-sectional analyses of linked statewide Food Stamp Program and OHP administrative databases (n = 10 175) and primary data from a statewide survey (n = 2681). RESULTS: More than 20% of parents with children not administratively enrolled in OHP reported that their children were enrolled. Parents of 11.3% of children who were administratively enrolled reported that they were not. Eligible but unenrolled children had higher odds of being older, having higher family incomes, and having employed and uninsured parents. CONCLUSIONS: These findings reveal an important discrepancy between administrative data and parent-reported access to public health insurance. This discrepancy may stem from transient coverage or confusion among parents and may result in underutilization of health insurance for eligible children.

The age and diversification of terrestrial New World ecosystems through Cretaceous and Cenozoic time.

Eight ecosystems that were present in the Cretaceous about 100 Ma (million years ago) in the New World eventually developed into the 12 recognized for the modern Earth. Among the forcing mechanisms that drove biotic change during this interval was a decline in global temperatures toward the end of the Cretaceous, augmented by the asteroid impact at 65 Ma and drainage of seas from continental margins and interiors; separation of South America from Africa beginning in the south at ca. 120 Ma and progressing northward until completed 90-100 Ma; the possible emission of 1500 gigatons of methane and CO(2) attributed to explosive vents in the Norwegian Sea at ca. 55 Ma, resulting in a temperature rise of 5°-6°C in an already warm world; disruption of the North Atlantic land bridge at ca. 45 Ma at a time when temperatures were falling; rise of the Andes Mountains beginning at ca. 40 Ma; opening of the Drake Passage between South America and Antarctica at ca. 32 Ma with formation of the cold Humboldt at ca. 30 Ma; union of North and South America at ca. 3.5 Ma; and all within the overlay of evolutionary processes. These processes generated a sequence of elements (e.g., species growing in moist habitats within an overall dry environment; gallery forests), early versions (e.g., mangrove communities without Rhizophora until the middle Eocene), and essentially modern versions of present-day New World ecosystems. As a first approximation, the fossil record suggests that early versions of aquatic communities (in the sense of including a prominent angiosperm component) appeared early in the Middle to Late Cretaceous, the lowland neotropical rainforest at 64 Ma (well developed by 58-55 Ma), shrubland/chaparral-woodland-savanna and grasslands around the middle Miocene climatic optimum at ca. 15-13 Ma, deserts in the middle Miocene/early Pliocene at ca. 10 Ma, significant tundra at ca. 7-5 Ma, and alpine tundra (páramo) shortly thereafter when cooling temperatures were augmented by high elevations attained, for example, in the Andes<10 Ma and especially after 7-6 Ma.

Postoperative sepsis in the United States.

OBJECTIVES: To evaluate the incidence of postoperative sepsis after elective procedures, to define surgical procedures with the greatest risk for developing sepsis, and to evaluate patient and hospital confounders. BACKGROUND DATA: The development of sepsis after elective surgical procedures imposes a significant clinical and resource utilization burden in the United States. We evaluated the development of sepsis after elective procedures in a nationally representative patient cohort and assessed the effect of sociodemographic and hospital characteristics on the development of postoperative sepsis. METHODS: The Nationwide inpatient sample was queried between 2002 and 2006 and patients developing sepsis after elective procedures were identified using the patient safety indicator "Postoperative Sepsis" (PSI-13). Case-mix adjusted rates were calculated by using a multivariate logistic regression model for sepsis risk and an indirect standardization method. RESULTS: A total of 6,512,921 weighted elective surgical cases met the inclusion criteria and 78,669 cases (1.21%) developed postoperative sepsis. Case-mix adjustment for age, race, gender, hospital bed size, hospital location, hospital teaching status, and patient income demonstrated esophageal, pancreatic, and gastric procedures represented the greatest risk for the development of postoperative sepsis. Thoracic, adrenal, and hepatic operations accounted for the greatest mortality rates if sepsis developed. Increasing age, Blacks, Hispanics, and men were more likely to develop sepsis. Decreased median household income, larger hospital bed size, urban hospital location, and nonteaching status were associated with greater rates of postoperative sepsis. CONCLUSIONS: The development of postoperative sepsis is multifactorial and procedures, most likely to develop sepsis, did not demonstrate the greatest mortality after sepsis developed. Factors associated with the development of sepsis included race, age, hospital size, hospital location, and patient income. Further evaluation of high-risk procedures, populations, and environments may assist in reducing this costly complication.

Infectious complications after elective vascular surgical procedures.

OBJECTIVE: This study was conducted to evaluate and compare the rates of postoperative infectious complications and death after elective vascular surgery, define vascular procedures with the greatest risk of developing nosocomial infections, and assess the effect of infection on health care resource utilization. METHODS: The Nationwide Inpatient Sample (2002-2006) was used to identify major vascular procedures by International Classification of Diseases, 9th Clinical Modification (ICD-9-CM) codes. Infectious complications identified included pneumonia, urinary tract infections (UTI), postoperative sepsis, and surgical site infections (SSI). Case-mix-adjusted rates were calculated using a multivariate logistic regression model for infectious complication or death as an outcome and indirect standardization. RESULTS: A total of 870,778 elective vascular surgical procedures were estimated and evaluated with an overall postoperative infection rate of 3.70%. Open abdominal aortic surgery had the greatest rate of postoperative infections, followed by open thoracic procedures and aorta-iliac-femoral bypass. Thoracic endovascular aneurysm repair (TEVAR) infectious complication rates were two times greater than after EVAR (P < .0001). Pneumonia was the most common infectious complication after open aortic surgery (6.63%). UTI was the most common after TEVAR (2.86%) and EVAR (1.31%). Infectious complications were greater in octogenarians (P < .0002), women (P < .0001), and blacks (P < .0001 vs whites and Hispanics). Nosocomial infections after elective vascular surgery significantly increased hospital length of stay (13.8 +/- 15.4 vs 3.5 +/- 4.2 days; P < .001) and reported total hospital cost ($37,834 +/- $42,905 vs $11,851 +/- $11,816; P < .001). CONCLUSIONS: Elective vascular surgical procedures vary widely in the estimated risk of postoperative infection. Open aortic surgery and endarterectomy of the head and neck vessels have, respectively, the greatest and the lowest reported incidence for postoperative infectious complications. Women, octogenarians, and blacks have the highest risk of infectious complications after elective vascular surgery. Disparities in the development of infectious complications on a systems level were also found in larger hospitals and teaching hospitals. Hospital infectious complications were found to significantly increase health care resource utilization. Strategies that reduce nosocomial complications and target high-risk procedures may offer significant future cost savings.

Carotid artery stenting: Impact of practitioner specialty and volume on outcomes and resource utilization.

OBJECTIVES: A variety of endovascular specialists perform carotid artery stenting (CAS), but little data exist on outcomes and resource utilization among these specialists. We analyzed differences in outcomes after CAS was performed by radiologists (RAD), cardiologists (CRD), and vascular surgeons (VAS). METHODS: Secondary data analysis of the 2005-2006 State Inpatient Databases for New Jersey were analyzed. Patients with elective admission to the hospital who had CAS procedure

Lower extremity angioplasty: impact of practitioner specialty and volume on practice patterns and healthcare resource utilization.

OBJECTIVES: Lower extremity percutaneous transluminal angioplasty (LE PTA) is currently performed by a variety of endovascular specialists. We hypothesized that cardiologists (CRD) and vascular surgeons (VAS) may have different practice patterns, indications for intervention, and hospital resource utilization. METHODS: Using the State Inpatient Databases for New Jersey (2003-2007), patients with elective admission undergoing PTA procedures with indications of claudication, rest pain, and gangrene/ulceration were examined. Physician specialty was determined based on all procedures performed. We contrasted by specialty, the indication for LE PTA for the procedure, volume, and hospital resource utilization. RESULTS: Of the 1887 cases of LE PTA, VAS performed 866 (45.9%) and CRD 1021 (54.1%) procedures. The mean patient age was 68.0 years (CRD) vs 70.7 years (VAS), P = .0163. Indications for intervention were compared for CRD vs VAS: claudication 80.7% vs 60.7%, (P < .002); rest pain 6.2% vs 16.0%, (P < .002); gangrene/ulceration 13.1% vs 23.3%, (P < .002). Stents (64.8% of cases) were utilized similarly among physicians (P = .18), and mean hospital length of stay were similar (2.38 days vs 2.41 days, P = .85). Hospital charges by indication varied between CRD vs VAS (all procedures: $49,748 vs $42,158 [P < .0001]). Revenue center charges were different between CRD vs VAS: medical surgical supply $19,128 vs $12,737, (P < .0001); pharmacy $1,959 vs $1,115, (P < .0001). Only 10.7% of CRD were high volume practitioners, compared with 36.8% among VAS (P < .05). High volume practitioners had significantly lower hospital charges ($41,730 vs $51,014, P < .001). CONCLUSIONS: Cardiologists performing lower extremity angioplasty were more likely to treat patients with claudication than those with rest pain or gangrene/ulceration. Despite treating younger patients with less severe peripheral vascular disease, cardiologists used significantly greater hospital resources. High practitioner volume, regardless of specialty, was associated with lower hospital resource utilization. Reducing variations in indication and practitioner volume may offer substantial cost savings for lower extremity endovascular interventions.

Outcomes of carotid artery stenting and endarterectomy in the United States.

OBJECTIVES: With the evolution of endovascular techniques, carotid artery stenting (CAS) has been compared to carotid endarterectomy (CEA). Several studies have reported inferior results with CAS in the elderly. The objective of this study was to evaluate national outcomes of CAS and CEA and to compare utilization and outcomes of these procedures in different age groups. METHODS: We evaluated the 2005 Nationwide Inpatient Sample for hospitalizations with a procedure of CAS or CEA within 2 days after admission at age 60 years and above. Procedures were analyzed with respect to patient demographics and associated complications. RESULTS: A total of 80,498 carotid interventions (73,929 CEA and 6,569 CAS) were identified. The overall incidence of stroke was 4.16% after CAS and 2.66% after CEA (P < .0001). CAS was more often utilized in octogenarians than in younger patients (8.55% in 80+ vs 7.92% in 60-69 years; P < .0002). Increased age was not associated with greater stroke rates after CAS or CEA (P = .19 and .06, respectively). Octogenarians, compared to younger patients, had greater cardiac, pulmonary, and renal complications after CEA (3.0% vs 1.9%, 1.9% vs 1.0%, and 1.4% vs 0.54%, respectively; P < .0001). When adjusted by age, gender, complications, and Elixhauser comorbidities, patients after CAS were 1.6 times as likely to have a stroke (confidence interval [CI] = 1.37-1.78) when compared to CEA. Significant predictors of postoperative hospital mortality were stroke (odds ratio [OR] = 29.0; 95% CI = 21.5-39.1), cardiac complications (OR = 6.4; 95% CI = 4.4-9.1), pulmonary complications (OR = 3.5; 95% CI = 2.31-5.19), and renal failure (OR = 2.5; 95% CI = 1.6-3.8). With increasing age, overall mortality steadily increased after CAS (from 0.23% to 0.67%; P = .0409) but remained stable after CEA. CONCLUSION: Octogenarians did not have a higher risk of stroke after CAS when compared to younger patients. Stroke was the strongest predictor of hospital mortality. The increased utilization of CAS in the aged, which had significantly higher stroke rates in all age groups studied, may account for the greater hospital mortality seen after CAS in the elderly. Further studies focused on the aged are needed to define the best management strategies in the elderly.

Quantifying a strategic view of diabetes technology impacts: a system dynamics approach.

BACKGROUND: Diabetes and its related complications and comorbidities (C&Cs) represent a significant and increasing healthcare burden. Absence of a systematic manner to evaluate value propositions of technologies from various stakeholders' perspectives impedes the best uses of current and emerging technologies. METHODS: A system dynamics methodology was used to develop a comprehensive causal simulator of the U.S. population and give proof of principle that entire portfolios of present and future technologies can be evaluated for direct and indirect impacts. An explicit semiquantitative methodology was used for surveying, prioritizing, and grouping C&Cs, patient subgroups, and technologies, utilizing diverse publicly available clinical literature. RESULTS: The resulting model simulates the incidence and prevalence of diabetes and 10 of its most commonly associated C&Cs, reflecting their interrelated upstream and downstream relationships. The simulator enables systematic evaluation of tens of thousands of potential combinations of emerging technologies and technology leverage points that can be used to improve patient outcomes and guide technology investments. Feasibility was demonstrated through single, pair-wise, and targeted analyses of technologies. CONCLUSIONS: This effort demonstrated the feasibility of linking complex, interconnected disease states, impact points, outcomes, and interventions with a variety of outcome metrics, to an extent greater than existing models developed for other purposes. The project demonstrated the ability to identify priority technologies and pipeline therapies and leverage points among diabetes interventions. It demonstrated more effective knowledge management of diverse information essential for formulating strategy that could be applied in a wide range of therapeutic applications and technology innovation uses.

Revisiting the use of granulocyte transfusions in pediatric oncology patients.

OBJECTIVE: To describe the clinical course of neutropenic pediatric oncology patients undergoing granulocyte transfusions (GTF). DESIGN: Retrospective chart review including all children receiving GTFs between March, 1998 and June, 2000. SETTING: Tertiary Children's Hospital and Regional Medical Center. PATIENTS: Thirteen pediatric oncology patients (age, 9 mo to 16 y) with neutropenia and proven or suspected serious infection. INTERVENTIONS: These 13 patients received a total of 14 courses of GTFs (number of transfusions per course ranged from 1 to 43, median=4.5). MEASUREMENTS AND MAIN RESULTS: Twelve of the patients had documented infections before GTF. Ten of the 14 courses (71%) were followed by survival to hospital discharge. All 5 patients who were intubated before GTF were extubated afterward. Two early deaths occurred due to invasive Aspergillus. No significant differences in monitoring laboratories were found. Ultimately, 8 of 13 (62%) patients in this group died. CONCLUSIONS: This case series documents the course of 13 septic neutropenic pediatric oncology patients who underwent a total of 14 GTF courses. GTFs were generally well tolerated with little decline in respiratory status or organ function. Short-term survival in this population was good whereas long-term outcome remains more difficult.

Has the implementation of EVAR for ruptured AAA improved outcomes?

OBJECTIVE: Previous studies have demonstrated improved outcomes with endovascular aneurysm repair (EVAR) for the treatment of ruptured abdominal aortic aneurysms (rAAA). However, these data may not be generalizable to all regions. METHODS: Retrospective cohort study (2001-2005) using state inpatient data. RESULTS: 5,176 patients underwent repair of AAA. 700 repairs were performed for rAAA (618 [88%] with open surgery (OS) and 82 [12%] with EVAR). Mortality for rAAA was similar for EVAR and OS (45.1% vs. 52.4%, P = 0.21). Lack of insurance (OR = 5.1; 95%CI: 1.7-15.2) was a predictor of mortality. Cost of repair for rAAA was greater for EVAR ($51,339 +/- 51,719 vs. $39,967 +/- 43,354, P = 0.03) and hospital LOS was similar (14.08 +/- 17.97 vs.13.42 +/- 18.18; P = 0.8). CONCLUSION: EVAR did not offer a survival benefit in the state, had a similar hospital LOS, and was significantly more expensive. Further evaluation exploring explanations for inferior outcomes by region are required as EVAR becomes more commonly implemented for rAAA.

Carotid body tumor surgery: management and outcomes in the nation.

OBJECTIVE: To evaluate the impact of carotid reconstruction (REC) and pre-operative embolization (EMB) for Carotid Body Tumor (CBT) surgery. METHODS: Retrospective study utilizing the Nationwide Inpatient Sample (2002-2006). RESULTS: 2117 patients (mean age 56.5 +/- 17.2 years) underwent CBT surgery: 1686 excision alone (EX); 129 excision with embolization (EX+EMB); and 302 excision with carotid artery reconstruction (EX+REC). EX+REC compared to EX had greater rates of mortality (1.61%vs.0.59%; P =.0495), stroke (17.7% vs. 3.5%; P < .0002), and postoperative hemorrhage (43.1% vs. 2.4%; P < 0.002). EX+EMB did not demonstrate increased mortality or stroke compared to EX and the rate of postoperative hematoma was similar between groups (P = .3144). CONCLUSIONS: CBT resection is a relatively rare procedure and when combined with EMB was more expensive, but was associated with significantly fewer complications and decreased blood product utilization. These data suggest that CBT surgery requiring carotid reconstruction carries significant morbidity and that EMB as an adjunctive tool was beneficial for CBT surgery outcomes.

CREG promotes a mature smooth muscle cell phenotype and reduces neointimal formation in balloon-injured rat carotid artery.

AIM: We previously showed that cellular repressor of E1A-stimulated genes (CREG) is up-regulated during serum starvation-induced vascular smooth muscle cell (SMC) differentiation. The aim of this study was to determine the role of CREG in maintaining the quiescent, differentiated phenotype of SMCs both in culture and in balloon-injured rat carotid artery. METHODS AND RESULTS: In cultured SMCs recombinant virus-mediated CREG expression enhanced cellular differentiation, inhibited proliferation, and reduced synthesis of extracellular matrix component fibronectin. In contrast, CREG knockdown via retroviral transfer of short hairpin RNAs abrogated serum starvation-induced SMC differentiation and growth arrest. Both immunostaining and Western analysis demonstrated marked down-regulation of CREG in the vascular media after balloon injury to the rat carotid artery. Retrovirus-mediated CREG transfer to the injured artery inhibited SMC dedifferentiation and proliferation, and reduced neointimal hyperplasia. CONCLUSION: These results suggest that CREG participates in the maintenance of quiescent mature SMC phenotype in the arterial media by promoting SMC differentiation and growth arrest and that CREG gene transfer has therapeutic potential for vascular diseases associated with neointimal hyperplasia.

Near-contact interactions between a sphere and a plane.

The hydrodynamic behavior observed for a sphere released under gravity in a Newtonian liquid is not consistent with that predicted by classical continuum theory when the sphere is near a solid wall. An irreversibility arises in the velocity of the sphere as it approaches and recedes from the plane that cannot be accounted for using continuum hydrodynamic equations alone. Earlier experiments on spheres falling from a plane were conducted under conditions such that this irreversibility could be attributed to the surface roughness of the spheres. In this investigation, we extend these studies to situations where the pressure field between the receding sphere and the plane drops to the vapor pressure of the fluid and cavitation occurs. Experimental data supports the theoretical prediction for a sphere's motion based on the irreversible effect of cavitation.