Post-Chemotherapy Histiocyte-Rich Pseudotumors: Radiologic and Endoscopic Mimics of Residual Lymphoma.

Development of post-chemotherapy histiocyte-rich pseudotumor (PHP) is an underrecognized event following therapy in lymphoma patients and may mimic residual tumor using current therapy monitoring protocols. We report a series of 5 patients with PHP along with a review of the literature. In our series, we describe 3 patients with persistent hypermetabolic masses by positron emission tomography-computed tomography, one with persistent terminal ileal nodules on endoscopy, and one with bone marrow involvement, a site not associated with mass-like disease. Twenty-three patients with long-term follow-up were identified from our series and review of the literature. Forty-four percent of patients received additional therapy, and only 4% of patients died of lymphoma. This study illustrates that PHPs are not identified using current lymphoma therapy monitoring algorithms and may result in overtreatment with risk for additional therapy-related complications. The need for confirmatory tissue biopsy in this setting is recommended.

A case report of right ventricular outflow tract obstruction caused by B-cell lymphoma: a rare presentation in an adult patient with pulmonary atresia.

BACKGROUND: Right ventricle outflow tract (RVOT) dysfunction is a common long-term complication in adult patients with pulmonary atresia/ventricular septal defect (PA/VSD). Common causes include valve thrombosis, stent fractures, and graft calcification. We present, to the best of our knowledge, the first case of malignant invasion of a Gore-Tex conduit, causing severe right ventricle (RV) failure. CASE SUMMARY: A 30-year-old woman with a history of PA/VSD with major aortopulmonary collateral arteries (MAPCAs) presented with worsening dyspnoea and exercise intolerance. In infancy, she underwent unifocalization of the right- and left-sided AP collaterals utilizing an 18 and 16 mm Gore-Tex graft, respectively. At age 7, she had surgical repair with VSD patch closure and placement of a 20 mm right ventricle-pulmonary artery (RVPA) homograft connected to a 20 mm Gore-Tex graft with linkage to the previously placed right and left unifocalization grafts. A transthoracic echocardiogram revealed a severely dilated RV and a heavily calcified RVOT conduit with severe stenosis. Cardiac computed tomography showed a stenotic RVPA conduit with calcified mural mass. She underwent surgical revision of the RVPA conduit with thromboendarterectomy of bilateral pulmonary arteries. Pathology of the removed conduit revealed fibrin-associated Epstein-Barr virus-positive diffuse large B-cell lymphoma (FA DLBCL). DISCUSSION: One prior case report has demonstrated invasion of DLBCL involving an aortic synthetic tube graft. However, malignant invasion of the RVOT Gore-Tex conduit has yet to be reported. Pathological review can be essential in guiding management. Malignant invasion of Gore-Tex conduits is a rare phenomenon, but one that should be closely monitored following repair of the RVOT.

Diffuse Large B-Cell Lymphoma With Striking Intrasinusoidal Pseudoglandular Growth Pattern as a Diagnostic Dilemma Mimicking Metastatic Poorly Differentiated Pancreatic Adenocarcinoma in an Intraabdominal Lymph Node.

We report an unusual intrasinusoidal growth pattern of an intraabdominal diffuse large B-cell lymphoma both clinically and histologically mimicking a metastatic adenocarcinoma. A 66-year-old woman presented with a high-grade distal biliary stricture with multiple enlarged abdominal lymph nodes. Frozen section at the time of pancreatoduodenectomy ("Whipple") demonstrated cohesive nests of large atypical cells within a totally effaced lymph node presenting a diagnostic challenge. Immunohistochemistry proved this to be a diffuse large B-cell lymphoma extensively involving the sinusoids.

Defense Strategies for Asymmetric Networked Systems with Discrete Components.

We consider infrastructures consisting of a network of systems, each composed of discrete components. The network provides the vital connectivity between the systems and hence plays a critical, asymmetric role in the infrastructure operations. The individual components of the systems can be attacked by cyber and physical means and can be appropriately reinforced to withstand these attacks. We formulate the problem of ensuring the infrastructure performance as a game between an attacker and a provider, who choose the numbers of the components of the systems and network to attack and reinforce, respectively. The costs and benefits of attacks and reinforcements are characterized using the sum-form, product-form and composite utility functions, each composed of a survival probability term and a component cost term. We present a two-level characterization of the correlations within the infrastructure: (i) the aggregate failure correlation function specifies the infrastructure failure probability given the failure of an individual system or network, and (ii) the survival probabilities of the systems and network satisfy first-order differential conditions that capture the component-level correlations using multiplier functions. We derive Nash equilibrium conditions that provide expressions for individual system survival probabilities and also the expected infrastructure capacity specified by the total number of operational components. We apply these results to derive and analyze defense strategies for distributed cloud computing infrastructures using cyber-physical models.

Longitudinal measurement invariance and explanatory IRT models for adolescents' oral health-related quality of life.

BACKGROUND: Longitudinal invariance is a perquisite for a valid comparison of oral health-related quality of life (OHRQoL) scores over time. Item response theory (IRT) models can assess measurement invariance and allow better estimation of the associations between predictors and latent construct. By extending IRT models, this study aimed to investigate the longitudinal invariance of the two 8-item short forms of the Child Perception Questionnaire (CPQ11-14) regression short form (RSF:8) and item-impact short form (ISF:8) and identify factors associated with adolescents' OHRQoL and its change. METHODS: All students from S1 and S2 (equivalent to US grades 6 and 7) who were born in April 1997 and May 1997 (at age 12) from 45 randomly selected secondary schools were invited to participate in this study and followed up after 3 years. Data on the CPQ11-14 RSF:8 and CPQ11-14 ISF:8, demographics, oral health behavior and status were collected. Explanatory graded response models were fitted to both short forms of the CPQ11-14 data for assessing longitudinal invariance and factors associated with OHRQoL. The Bayesian estimation method - Monte Carlo Markov Chain (MCMC) with Gibbs sampling was adopted for parameter estimation and the credible intervals were used for inference. RESULTS: Data from 649 children at age 12 at baseline and 415 children at age 15 at follow up were analyzed. For the 12 years old children, healthier oral health behavior, better gum status, families with both parents employed and parents' education level were found to be associated with better OHRQoL. Four items among the 2 short forms lacked longitudinal invariance. With statistical adjustment of longitudinal invariance, OHRQoL were found improved in general over the 3 years but no predictor was associated with OHRQoL in follow-up. For those with decreased family income, their OHRQoL had worsened over 3 years. CONCLUSIONS: IRT explanatory analysis enables a more valid identification of the factors associated with OHRQoL and its changes over time. It provides important information to oral healthcare researchers and policymakers.

Defense of Cyber Infrastructures Against Cyber-Physical Attacks Using Game-Theoretic Models.

The operation of cyber infrastructures relies on both cyber and physical components, which are subject to incidental and intentional degradations of different kinds. Within the context of network and computing infrastructures, we study the strategic interactions between an attacker and a defender using game-theoretic models that take into account both cyber and physical components. The attacker and defender optimize their individual utilities, expressed as sums of cost and system terms. First, we consider a Boolean attack-defense model, wherein the cyber and physical subinfrastructures may be attacked and reinforced as individual units. Second, we consider a component attack-defense model wherein their components may be attacked and defended, and the infrastructure requires minimum numbers of both to function. We show that the Nash equilibrium under uniform costs in both cases is computable in polynomial time, and it provides high-level deterministic conditions for the infrastructure survival. When probabilities of successful attack and defense, and of incidental failures, are incorporated into the models, the results favor the attacker but otherwise remain qualitatively similar. This approach has been motivated and validated by our experiences with UltraScience Net infrastructure, which was built to support high-performance network experiments. The analytical results, however, are more general, and we apply them to simplified models of cloud and high-performance computing infrastructures.

Evaluation of psychometric properties and differential item functioning of 8-item Child Perceptions Questionnaires using item response theory.

BACKGROUND: Four-factor structure of the two 8-item short forms of Child Perceptions Questionnaire CPQ11-14 (RSF:8 and ISF:8) has been confirmed. However, the sum scores are typically reported in practice as a proxy of Oral health-related Quality of Life (OHRQoL), which implied a unidimensional structure. This study first assessed the unidimensionality of 8-item short forms of CPQ11-14. Item response theory (IRT) was employed to offer an alternative and complementary approach of validation and to overcome the limitations of classical test theory assumptions. METHODS: A random sample of 649 12-year-old school children in Hong Kong was analyzed. Unidimensionality of the scale was tested by confirmatory factor analysis (CFA), principle component analysis (PCA) and local dependency (LD) statistic. Graded response model was fitted to the data. Contribution of each item to the scale was assessed by item information function (IIF). Reliability of the scale was assessed by test information function (TIF). Differential item functioning (DIF) across gender was identified by Wald test and expected score functions. RESULTS: Both CPQ11-14 RSF:8 and ISF:8 did not deviate much from the unidimensionality assumption. Results from CFA indicated acceptable fit of the one-factor model. PCA indicated that the first principle component explained >30 % of the total variation with high factor loadings for both RSF:8 and ISF:8. Almost all LD statistic <10 indicated the absence of local dependency. Flat and low IIFs were observed in the oral symptoms items suggesting little contribution of information to the scale and item removal caused little practical impact. Comparing the TIFs, RSF:8 showed slightly better information than ISF:8. In addition to oral symptoms items, the item "Concerned with what other people think" demonstrated a uniform DIF (p < 0.001). The expected score functions were not much different between boys and girls. CONCLUSIONS: Items related to oral symptoms were not informative to OHRQoL and deletion of these items is suggested. The impact of DIF across gender on the overall score was minimal. CPQ11-14 RSF:8 performed slightly better than ISF:8 in measurement precision. The 6-item short forms suggested by IRT validation should be further investigated to ensure their robustness, responsiveness and discriminative performance.

The relationship between consumption of beverages and tooth wear among adults in the United States.

OBJECTIVES: To investigate the prevalence and severity of tooth wear (TW) and its relationship with consumption of beverages among adults in the United States. METHODS: The National Health and Nutrition Examinations Survey data for 2003-2004 was analyzed. TW was defined as "wear on at least one surface of at least one examined tooth." Drink/juice consumption was ascertained via a Food Frequency Questionnaire processed with Diet*Calc software to obtain the average daily consumption frequency for all queried drinks and juice categories including milk. Survey-weighted descriptive and multivariable analyses with interaction terms were performed. RESULTS: Our study sample consisted of 3,773 adults (aged 20 and above). Eighty percent of the subjects had evidence of TW, and soft drinks were the most consumed beverage. Significant interactions between the effects of age, gender, and race/ethnicity on TW were found (P < 0.001). After adjustment for demographic factors, consumption of fruit drinks was found to be significantly associated with the severity [odds ratio (OR) = 1.32 and 1.42], but not prevalence of TW. However, this trend was reversed for grape juice consumption (OR = 0.34, 0.41). CONCLUSIONS: This study demonstrates that a substantial proportion of adults had evidence of TW, which was affected by demographic factors in a complex way. Fruit drinks consumption in adults was associated with the severity of TW, but not with the prevalence of TW after adjusting for demographics. These findings are important for the development of appropriate treatment guidelines, public policy, and programs aimed at reducing TW in adults.

Exogenous collagen crosslinking of the intervertebral disc restores joint stability after lumbar posterior decompression surgery.

STUDY DESIGN: In vitro evaluation of a chemical, injectable intervention for discectomy induced destabilization. OBJECTIVE: To investigate the ability of two collagen crosslinking agents to restore mechanical properties to lumbar joints destabilized by surgical decompression procedures. SUMMARY OF BACKGROUND DATA: Posterior decompression surgery is a common procedure indicated for tissue pathology that interferes with surrounding neural structures. Previous in vitro, analytical, and clinical studies have shown that removal of load-supporting tissue can compromise joint stability mandating some form of postsurgical stabilization. Currently, no nonsurgical treatments are capable of restoring stability and preventing subsequent degeneration. Exogenous crosslinking of intact discs has shown a fourfold increase in joint stability. METHODS: Fifteen bovine lumbar intervertebral joints were randomly separated into methylglyoxal or genipin treatment groups. Flexion-extension flexibility was quantified in three conditions: intact, postdecompression surgery, and after crosslinking reagent injections. Instability was quantified by calculating neutral zone (NZ), percentage of hysteresis, range of motion, and percentage of strain energy. RESULTS: Simulated surgical decompression increased NZ 111% (P = 0.009), 28% (P = 0.004), range of motion 57% (P = 0.003), and decreased strain energy 37% (P = 0.004). For those discs undergoing methylglyoxal treatment NZ was subsequently reduced 68% (P = 0.012), hysteresis 28% (P = 0.018), range of motion 29% (P = 0.012), and strain energy was increased 71% (P = 0.018). For discs subjected to genipin treatment, NZ was reduced 52% (P = 0.018), hysteresis 23% (P = 0.012), range of motion 44% (P = 0.017), and strain energy was increased 66% (P = 0.012). Mean NZ was lower than intact mean after both methylglyoxal and genipin treatments, 10% and 17% less, respectively, but these differences were not significant. Mean values for all other parameters posttreatment were within 6% of the corresponding intact mean values. CONCLUSION: Injections of crosslinking reagents into lumbar intervertebral discs after simulated decompression surgery restored joint stability according to all parameters. Similar results were found for genipin and methylglyoxal reagents. Implementing exogenous collagen crosslinking as an adjunct to current surgical decompression procedures may be beneficial in preventing or delaying subsequent spinal instability and degeneration.

Heat-induced phosphorylation of NBS1 in human skin fibroblast cells.

NBS1 is known to be involved in DNA damage-induced cellular responses after exposure to ionizing radiation (IR). Phosphorylation of NBS1 contributes to cell-cycle checkpoints. The aim of this study was to determine whether heat exposure induces or stimulates cellular responses mediated by the phosphorylation of NBS1 in human skin fibroblast cell lines. The results of immunofluorescent staining and Western blot analysis showed that NBS1 proteins are phosphorylated after exposure to heat in the nucleus of a normal skin fibroblast cell line (82-6 cells). This suggests that the NBS1-mediated signal transduction could be induced by heat. We further examined whether a deficiency in the NBS1 protein modifies heat sensitivity in human skin fibroblast cell lines. A skin fibroblast cell line (Gmtert), derived from a Nijmegen breakage syndrome (NBS) patient containing mutant NBS1, showed higher sensitivity to heat than the same cell line transfected with the wild-type copy of the NBS1 gene. We also showed that transfection of a DNA cassette expressing small interference RNA (siRNA) targeted to NBS1 into 82-6 cells enhanced cell sensitivity to heat. These results suggest that NBS1 is involved in cellular responses to DNA damage which is induced by heat exposure as well as by radiation exposure in human skin fibroblast cells.