Orientation Development of Mixed Anisotropic Particles in Compounds

An experimental study of the development of orientation of mixed fiber and flake polymer compounds in polymer processing operation including extrusion and molding is discussed. Aramid fiber and talc and mica flakes are studied. The orientation of the particles is determined using wide angle x-ray diffraction. It is found that mixed particle systems lead to lower orientation of both fibers and flakes. The fibers tend to orient in the primary machine direction, while the flakes tend to orient perpendicular to the fibers. This is distinct from fiber compounds and flake compounds where fibers orient in the plane of the machine and transverse directions and flakes orient parallel to machine surfaces.

Development of Phase Morphology of a Polyethylene-Polyamide 6-Blend in a Modular Co-rotating Twin Screw Extruder

A basic study of blending two different polymers (polyethylene and polyamide 6) in a modular co-rotating twin screw extruder is presented. The development of phase morphology was observed along the axis of the modular screw. Five different modular screw designs are considered. We first look at a machine containing all right-handed screw elements. We then consider a machine with all right-handed elements plus a single left-handed screw element. The study then turns to machines with combined screw and kneading disc elements. The kneading discs play a key role in both melting polymers and in enhancing dispersive mixing. Increasing the number of kneading disc blocks gives enhanced dispersion.

Flow Mechanisms, Material Distributions and Phase Morphology Development in a Modular Intermeshing Counter-Rotating Twin Screw Extruder of Leistritz Design

An experimental study is presented of the mixing of polyamide-6 and polyethylene in a Leistritz modular counter-rotating twin screw extruder. Seven different screw configurations were investigated and the material distributions and phase morphology developments along the axis of the screw were characterized. The behavior of different modular elements was determined including screw flights of varying thickness, Kiesskalt compression elements and shearing elements.

Differentiating xanthogranulomatous cholecystitis from wall-thickening type of gallbladder cancer: added value of diffusion-weighted MRI

AIM

To evaluate the benefit of diffusion-weighted imaging (DWI) in differentiating xanthogranulomatous cholecystitis from the wall-thickening type of gallbladder cancer.

MATERIALS AND METHODS

This retrospective study was approved by the institutional review board. Fourteen patients with xanthogranulomatous cholecystitis and 19 patients with the wall-thickening type of gallbladder cancer were included. Qualitative (visual diffusion restriction compared to liver parenchyma) and quantitative [apparent diffusion coefficient (ADC)] analyses were performed. Conventional MRI findings including dynamic enhancement pattern between the two groups were also analysed. Two observers independently reviewed conventional magnetic resonance imaging (MRI) images and subsequently reviewed combined conventional MRI and DWI images. Pairwise comparison of the receiver operating characteristic (ROC) curves was used to compare diagnostic performances.

RESULTS

In conventional MRI findings, xanthogranulomatous cholecystitis showed significant continuity of enhancing mucosal line [79% (11/14) versus 26% (5/19), p = 0.003] and intramural T2-high signal intensity [64% (9/14) versus 21% (4/19), p = 0.012] compared to the wall-thickening type of gallbladder cancer. The enhancement pattern of gallbladder cancer compared to liver parenchyma showed earlier onset than that of xanthogranulomatous cholecystitis (p = 0.001). Diffusion restriction was more frequently seen in the wall-thickening type of gallbladder cancer (68%, 13/19) than in xanthogranulomatous cholecystitis (7%, 1/14; p < 0.001). The mean ADC value of xanthogranulomatous cholecystitis was higher than that of the wall-thickening type of gallbladder cancer with statistical significance (1.637 × 10(-3) mm(2)/s versus 1.076 × 10(-3) mm(2)/s, p = 0.005). Diagnostic performance [area under ROC curve (Az)] of both observers improved significantly after additional review of DWI; Az improved from 0.737 to 0.930 (p = 0.027) for observer 1 and from 0.675 to 0.938 (p = 0.008) for observer 2.

CONCLUSION

Addition of DWI to conventional MRI improves discrimination between xanthogranulomatous cholecystitis and the wall-thickening type of gallbladder cancer.

Gonadotrophin-releasing hormone signalling downstream of calmodulin

Gonadotrophin-releasing hormone (GnRH) regulates reproduction via binding a G-protein coupled receptor on the surface of the gonadotroph, through which it transmits signals, mostly via the mitogen-activated protein (MAPK) cascade, to increase synthesis of the gonadotrophin hormones: luteinising hormone (LH) and follicle-stimulating hormone (FSH). Activation of the MAPK cascade requires an elevation in cytosolic Ca(2+) levels, which is a result of both calcium influx and mobilisation from intracellular stores. However, Ca(2+) also transmits signals via an MAPK-independent pathway, through binding calmodulin (CaM), which is then able to bind a number of proteins to impart diverse downstream effects. Although the ability of GnRH to activate CaM was recognised over 20 years ago, only recently have some of the downstream effects been elucidated. GnRH was shown to activate the CaM-dependent phosphatase, calcineurin, which targets gonadotrophin gene expression both directly and indirectly via transcription factors such as nuclear factor of activated T-cells and Nur77, the Transducer of Regulated CREB (TORC) co-activators and also the prolyl isomerase, Pin1. Gonadotrophin gene expression is also regulated by GnRH-induced CaM-dependent kinases (CaMKs); CaMKI is able to derepress the histone deacetylase-inhibition of β-subunit gene expression, whereas CaMKII appears to be essential for the GnRH-activation of all three subunit genes. Asides from activating gonadotrophin gene expression, GnRH also exerts additional effects on gonadotroph function, some of which clearly occur via CaM, including the proliferation of immature gonadotrophs, which is dependent on calcineurin. In this review, we summarise these pathways, and discuss the additional functions that have been proposed for CaM with respect to modifying GnRH-induced signalling pathways via the regulation of the small GTP-binding protein, Gem, and/or the regulator of G-protein signalling protein 2.

Expression of IL-10 and GM-CSF in Blood Monocytes and Alveolar Macrophages

Peripheral blood monocytes (PBMs) and alveolar macrophages (AMs) are widely recognized as cells that play a central role in the regulation of immune and inflammatory activities, as well as in tissue remodeling. The fulfillment of these activities is mediated by complex and multifactorial processes involving products derived from macrophages and monocytes (1). Monocytes are an important source of cytokines that are released in asthma and are likely precursor cells to AMs. Macrophages usually elaborate powerful suppressive signals to limit the proliferative potential of T-cells, thus maintaining local immunologic homeostasis (2). In asthma, macrophages and monocytes may be stimulated by specific allergens to augment T-cell proliferation (3), which may result from a different profile of cytokines released from these cells. For example, increased release of granulocyte-macrophage colony-stimulating factor (GM-CSF) may inhibit the immunosuppressive effect of macrophages (4). Indeed, macrophages and monocytes from asthmatic subjects release increased amounts of proinflammatory cytokines, such as interleukin-1β (IL-1), tumor necrosis factor-α, Interferon-γ (IFN-γ), IL-6, and GM-CSF (5-8). Inhaled steroids used for the treatment of asthma reduce the number of infiltrating eosinophils, T-cells, macrophages, and mast cells in the airway submucosa (9). Suppression of proinflammatory cytokine release, such as GM-CSF, IL-4, IL-5, and regulated upon activation, normal T-cell expressed and secreted (RANTES), from many inflammatory and resident airway cells, is a likely mechanism of steroid action (10-12). Proinflammatory cytokine expression.

Effectiveness and Safety of a Multicenter Extension and Retreatment Trial of Gel-200 in Patients with Knee Osteoarthritis

OBJECTIVE

To assess the continued effectiveness and safety of Gel-200 following observation and open-label retreatment in an extension protocol following a randomized, double-blind, phosphate buffered saline (PBS)-controlled trial (initial treatment trial).

DESIGN

Patients who completed initial blinded treatment were allowed to enroll into this extension protocol that permitted retreatment with Gel-200 when eligibility criteria were met. Retreatment was administered with a Gel-200 injection, without knowledge of initial treatment assignment (Gel-200 or PBS). Retreated patients were followed for up to 13 weeks. In the extension phase, durability of response following the first injection was analyzed by time to retreatment eligibility. During separate extension and retreatment phases, responses were assessed by WOMAC pain, stiffness, and physical function subscores, total score, and global assessments of disease activity (patient, physician) as well as safety of Gel-200.

RESULTS

In the extension phase, time-to-event analyses through 26 weeks following the initial injection showed statistically significantly longer times to retreatment in patients receiving Gel-200 compared with PBS (P < 0.05). Retreatment with Gel-200, e.g., a second injection, resulted in statistically significant improvements from retreatment baseline in all outcome measures (P < 0.0001). The incidence and type of adverse events after retreatment were comparable to those observed following initial injection of Gel-200 without allergic reactions, including "pseudosepsis" or unanticipated treatment-related serious adverse events.

CONCLUSIONS

These data demonstrate that a single injection of Gel-200 resulted in durable effectiveness through 26 weeks and that repeated treatment with Gel-200 relieved symptomatic osteoarthritis with a favorable safety profile.

Divergence of the systemic immune response following oral infection with distinct strains of Porphyromonas gingivalis

Periodontitis is a polymicrobial oral infection characterized by the destruction of tooth-supporting structures that can be linked to systemic diseases such as cardiovascular disease, diabetes or rheumatoid arthritis. Porphyromonas gingivalis, a bacterium implicated in the etiology of periodontitis, has shown variation in inducing T-cell responses among different strains. Therefore, in this study we investigated the strain-specific immune response using a murine experimental model of periodontitis. Periodontitis was induced by P. gingivalis strains A7A1-28, W83 and W50, and later confirmed by the presence of P. gingivalis in the oral microflora and by alveolar bone resorption. Splenocytes were evaluated for gene expression, cellular proteins and cytokine expression. Dendritic cells were stimulated in vitro for T helper cell-cytokine profiling. Results showed that P. gingivalis had the ability to alter the systemic immune response after bacterial exposure. Strains W50 and W83 were shown to induce alveolar bone loss, whereas the A7A1-28 strain did not significantly promote bone resorption in mice. Splenocytes derived from mice infected with strains W50 and W83 induced expression of high levels of interleukin-4 (IL-4) but A7A1-28 stimulated increased IL-10. Stimulation of dendritic cells in vitro showed a similar pattern of cytokine expression of IL-12p40, IL-6 and transforming growth factor-β among strains. A distinct systemic response in vivo was observed among different strains of P. gingivalis, with IL-10 associated with the least amount of alveolar bone loss. Evaluation of pathogen-driven systemic immune responses associated with periodontal disease pathogenesis may assist in defining how periodontitis may impact other diseases.

Comparison between sitagliptin as add-on therapy to insulin and insulin dose-increase therapy in uncontrolled Korean type 2 diabetes: CSI study

AIM

Individuals requiring insulin therapy for type 2 diabetes often require escalation of their regimen to achieve glycaemic control. Optimal management strategies for uncontrolled type 2 diabetes would improve glycaemic control without hypoglycaemia and weight gain. This study compared the efficacy and tolerability of adding sitagliptin, an oral dipeptidyl peptidase-4 inhibitor, and an up to 20% increase in insulin dose in patients with uncontrolled type 2 diabetes on insulin therapy.

METHODS

We conducted a 24-week, randomized, active-competitor, parallel-group study in subjects with uncontrolled type 2 diabetes [haemoglobin A1c (HbA1c) = 7.5-11%] currently using insulin therapy. Subjects were randomly assigned to either the sitagliptin adding (100 mg daily, n = 70) or an insulin-increasing arm (≥ 10% at week 12 and ≥ 10% at week 24, n = 70) while continuing other medications.

RESULTS

Average baseline HbA1c was 9.2% in both groups. HbA1c decreased more at 24 weeks in the sitagliptin adding than the insulin-increasing arm (-0.6 ± 0.1% vs. -0.2 ± 0.1%, p < 0.01). Insulin was increased by 25% at 24 weeks in the insulin-increasing group. Hypoglycaemic events were less common and less severe in sitagliptin adding arm than insulin-increasing arm (7.0 vs. 14.3 events per patient-year, p < 0.05). Weight was stable in the sitagliptin adding subjects (68.6 ± 11.6 vs. 68.1 ± 11.4 kg) but increased in the insulin-increasing subjects (66.2 ± 10.6 vs. 67.4 ± 9.7 kg, p < 0.05). Other adverse events occurred at similar rates in both arms.

CONCLUSIONS

Compared to a 25% increase in insulin dose, adding sitagliptin to an insulin-based regimen was more effective at lowering HbA1c and associated with less hypoglycaemia and weight gain over 24 weeks.

CLINICAL TRIAL NUMBER

NCT01100125.

SU-E-T-534: Beam and MLC Commissioning and Assessment of Three Commercial Treatment Planning Systems

PURPOSE

To assess and compare the open beam and multi-leaf collimator modeling of Pinnacle, Ecilpse (AAA and Acuros) and RayStation planning systems.

METHOD AND MATERIALS

The 6MV photon beam of a Varian TrueBeam with Millennium 120 MLC was used for this study. Measurements made with combinations of ion chamber, radiochromic film, and diodes in water and plastic phantoms. Depth and crossplane profiles of open square fields shaped by jaws or MLC ranged from 3×3 to 40×40cm² and from 0 to 20 cm depth. Depth dose, flatness (80% of FWHM), and penumbra (20-80%) of calculated and measured profiles were compared. Various MLC test patterns were calculated and compared with measurements to assess the modeling of the round leaf edge, tongue-and-groove, and interleaf transmissions.

RESULTS

Calculated depth doses are within 1.0% and flatness is within 2% for all field sizes and depths. Jaw penumbrae are within 2mm and 3mm for 20×20 and 30×30cm² at 10cm depth respectively. MLC penumbrae (20-80%) of the three systems are within 0.3mm and 1.0mm for a 3×3cm² and 10×10cm² MLC apertures. Notably, to match the measured MLC round-edge transmission, the half thickness (10% transmission) leaf-tip width of the current RayStation MLC model has to be broadened to 10mm. All three systems appear to adequately model the tongue-and-groove. Pinnacle explicitly models the interleaf transmission while Eclipse and RayStation simply use average MLC transmission.

CONCLUSIONS

All three systems are capable of generating clinically acceptable beam models for open fields. Based upon the round-edge profile, Eclipse and Pinnacle provide better MLC models than RayStation. Among the three systems, Eclipse took the least time and effort to commission these features.

SU-E-T-532: Comparison of Dose Distributions Calculated Using Different Planning Systems with Radiochromic Film Measurements in an Inhomogeneous Phantom

PURPOSE

Accurate modeling of the dose distribution in a lung tumor is challenging for traditional dose calculation algorithms. We compare the dose distributions of four commercial dose calculation Methods: Raysearch (Raysearch Laboratories) and Pinnacle (Philips Healthcare) collapsed cone, and Eclipse AAA and Eclipse Acuros,(Varian Medical Systems) with measurements using radiochromic film in a lung tumor phantomMethods: A simple lung tumor phantom was constructed using a thermoplastic cylinder 29 mm diameter and 40mm in length (density 1.3 gm/cc) imbedded in cork phantom 25 × 25 × 20 cm of density 0.32 gm/cc. Nine film layers normal to the axis of the cylinder where placed between layers of cork, above, below and through the cylindrical inhomogeneity. The phantom was irradiated with a single asymmetric 10×10 cm 6 MV field with the central axis collinear with the cylinder axis. Thirteen film exposures at 5 cm depth taken with doses 0-10 Gy were used to calibrate the film. The phantom was CT scanned and the DICOM study loaded into each of the treatment planning systems to calculate the dose distribution in the phantom.

RESULTS

Away from cork-poly interfaces, agreement between the four algorithms was within 3% of the film measurements. For Acuros, the dose at the edge of the cylinder was found to be up to 2% lower than that at the center of the cylinder possibly because of the loss of lateral electron equilibrium.

CONCLUSIONS

All four algorithms achieved remarkable agreement with the radiochromic film measurement. The Acuros algorithm appeared to more accurately model the peripheral dose deficit in the tumor, although a more detailed study is required for confirmation.

Metastatic parathyroid carcinoma initially misdiagnosed as parathyroid adenoma: the role of parafibromin in increasing diagnostic accuracy

Parathyroid carcinoma, although a rare cause of primary hyperparathyroidism, carries a significant morbidity and mortality from severe symptomatic hypercalcaemia and related complications. We report a case where the diagnosis was not considered from the outset and review the current clinical and histopathological markers available to assist in the diagnosis of parathyroid carcinoma.