Detecting factor XIa in immune globulin products: Commutability of international reference materials for traditional and global hemostasis assays.

BACKGROUND: Activated coagulation factor XIa (FXIa) is an impurity and primary source of procoagulant activity in thrombosis-implicated immune globulin (IG) products. Several assays, of varying quality and precision are used to assess FXIa-like procoagulant activity in units relevant to their respective principles. OBJECTIVES: To advance unified reporting, we sought to employ the World Health Organization reference reagents (RRs) to present the results of differing methodologies in units of FXIa activity and rank the sensitivity and robustness of these methodologies. METHODS: RR 11/236 served as a calibrator in several FXIa-sensitive blood coagulation tests: two commercial chromogenic FXIa assays (CAs); a nonactivated partial thromboplastin time (NaPTT); an in-house fibrin generation (FG) assay; an in-house thrombin generation (TG) assay; and an assay for FXIa- and kallikrein-like proteolytic activities based on cleavage of substrate SN13a. Some assays were tested in either normal or FXI-deficient plasma. RESULTS: Each method demonstrated a sigmoidal dose-response to RRs. NaPTT was the least sensitive to FXIa and the least precise; our in-house TG was the most sensitive; and the two CAs were the most precise. All methods, except for SN13a, which is less specific for thrombotic impurities, gave comparable (within 20% difference) FXIa activity assignments for IG lots. CONCLUSIONS: Purified FXIa reference standards support quantitation of FXIa levels in IG products in all tested assay methodologies. This should help to standardize the measurement of thrombotic potentials in IG products and prevent products exhibiting high procoagulant activity from distribution for patient use. Further research is needed to address the effect of IG product-specific matrixes on assay performance.

The Effect of Zero Copayments on Medication Adherence in a Community Pharmacy Setting.

BACKGROUND: Prescription medication copayments can be a financial burden to many patients. When patients cannot afford their medications, they may become nonadherent, and as a result, this can lead to an increase in chronic disease complications and healthcare costs. OBJECTIVE: The objective of this study was to determine if zero copayments have an effect on medication adherence in a community pharmacy. METHODS: This retrospective cohort study examined the prescription refill records of patients who filled specific generic medications for hypertension, hyperlipidemia, and gastroesophageal reflux disease (GERD) in 2016 at the NSU Clinic Pharmacy. The adherence rates of patients with zero copayments were compared to the adherence rates of patients with copayments greater than $0. Adherence was determined by calculating the proportion of days covered (PDC). Patients were considered adherent if their PDC was greater than or equal to 80%. RESULTS: GERD patients with no copayments had average PDC ratios of 87.4% and were statistically significantly more adherent than GERD patients with copayments, who had average PDC ratios of 76.7% (P = 0.042). Hyperlipidemia and hypertension patients with no copayments had average PDC ratios of 89.3% and 90.3%, respectively, and those with copayments had PDC ratios of 85.3% (P = 0.314) and 87.9% (P = 0.534). CONCLUSION: Overall, patients with $0 copayments had higher adherence rates than patients with copayments greater than $0. GERD patients with no copayments were significantly more adherent than GERD patients with copayments. However, no statistically significant difference was found between patients with or without copayments in the hyperlipidemia and hypertension cohorts. Further studies are recommended to analyze additional factors that may influence medication adherence.

A Sustainable Model for Patient follow-up following an International Cleft Mission: A Proof of Concept.

PURPOSE: Patient follow-up after cleft missions is imperative if we are to critically assess the quality of care provided in these settings. The adoption of mobile telephones among disadvantaged families abroad may enable such an undertaking in a cost-effective manner. This project aimed to assess the efficacy of cellular phone-based follow-up in a developing country following a cleft mission to Thailand. METHODS: Changing Children's Lives Inc. performed a cleft surgical mission to Udon Thani, Thailand, in January 2013. Telephone numbers collected at that time were used to survey the patients or their parents 1.5 years postoperatively. RESULTS: Of the 56 patients who underwent cleft lip and/or palate surgery during the mission, more than 50% ( n = 30, 54%) were reachable by telephone; all chose to participate in the study. The cost for families was U.S. $124.92 (56.15); 26 families (87%) believed their money was well spent. Follow-up care was received by 22 (73%) patients, and all but one family ( n = 29, 97%) felt that their child received all of the medical care and support required. All families ( N = 30) would recommend similar cleft care to a friend. Of the patients younger than 18 years of age ( n = 24, 80%), 20 (80%) families found their child more comfortable interacting with peers, more comfortable interacting with adults, and more confident postoperatively. CONCLUSION: In one month, a survey response rate of more than 50% was obtained by leveraging the increased adoption of mobile phones in rural settings. Nearly all patients/families treated during the cleft mission were satisfied with the care that they received.

A free-boundary model of diffusive valley growth: theory and observation.

Valleys that form around a stream head often develop characteristic finger-like elevation contours. We study the processes involved in the formation of these valleys and introduce a theoretical model that indicates how shape may inform the underlying processes. We consider valley growth as the advance of a moving boundary travelling forward purely through linearly diffusive erosion, and we obtain a solution for the valley shape in three dimensions. Our solution compares well to the shape of slowly growing groundwater-fed valleys found in Bristol, Florida. Our results identify a new feature in the formation of groundwater-fed valleys: a spatially variable diffusivity that can be modelled by a fixed-height moving boundary.

Statistical mechanics of stochastic growth phenomena.

We develop statistical mechanics for stochastic growth processes and apply it to Laplacian growth by using its remarkable connection with a random matrix theory. The Laplacian growth equation is obtained from the variation principle and describes adiabatic (quasistatic) thermodynamic processes in the two-dimensional Dyson gas. By using Einstein's theory of thermodynamic fluctuations we consider transitional probabilities between thermodynamic states, which are in a one-to-one correspondence with simply connected domains occupied by gas. Transitions between these domains are described by the stochastic Laplacian growth equation, while the transitional probabilities coincide with a free-particle propagator on an infinite-dimensional complex manifold with a Kähler metric.

Stochastic Laplacian growth.

A point source on a plane constantly emits particles which rapidly diffuse and then stick to a growing cluster. The growth probability of a cluster is presented as a sum over all possible scenarios leading to the same final shape. The classical point for the action, defined as a minus logarithm of the growth probability, describes the most probable scenario and reproduces the Laplacian growth equation, which embraces numerous fundamental free boundary dynamics in nonequilibrium physics. For nonclassical scenarios we introduce virtual point sources, in which presence the action becomes the Kullback-Leibler entropy. Strikingly, this entropy is shown to be the sum of electrostatic energies of layers grown per elementary time unit. Hence the growth probability of the presented nonequilibrium process obeys the Gibbs-Boltzmann statistics, which, as a rule, is not applied out from equilibrium. Each layer's probability is expressed as a product of simple factors in an auxiliary complex plane after a properly chosen conformal map. The action at this plane is a sum of Robin functions, which solve the Liouville equation. At the end we establish connections of our theory with the τ function of the integrable Toda hierarchy and with the Liouville theory for noncritical quantum strings.

Selection of the Taylor-Saffman bubble does not require surface tension.

A new general class of exact solutions is presented for the time evolution of a bubble of arbitrary initial shape in a Hele-Shaw cell when surface tension effects are neglected. These solutions are obtained by conformal mapping the viscous flow domain to an annulus in an auxiliary complex plane. It is then demonstrated that the only stable fixed point (attractor) of the nonsingular bubble dynamics corresponds precisely to the selected pattern. This thus shows that, contrary to the established theory, bubble selection in a Hele-Shaw cell does not require surface tension. The solutions reported here significantly extend previous results for a simply connected geometry (finger) to a doubly connected one (bubble). We conjecture that the same selection rule without surface tension holds for Hele-Shaw flows of arbitrary connectivity.

Efficacy and tolerability of second- and third-generation antihistamines in the treatment of acquired cold urticaria: a meta-analysis.

BACKGROUND: Acquired cold urticaria (ACU) is a form of physical urticaria that has been treated with first-generation antihistamines; there is a paucity of data regarding second- and third-generation antihistamines for the treatment of ACU. OBJECTIVE: To perform a systematic review of the literature to determine the efficacy of second- and third-generation antihistamines in the treatment of ACU. METHODS: Data were extracted via a MEDLINE search of the literature between 1950 and May 2009. We included double-blind, randomized, placebo-controlled studies comparing the treatment of patients with ACU with second- and third-generation antihistamine medications vs placebo. RESULTS: Overall, 98 patients were identified from 4 included studies. Two trials indicated that second- and third-generation antihistamines significantly eliminated the presence of wheals after treatment vs placebo (odds ratio [OR], 8.88; 95% confidence interval [CI], 4.35 to 18.13). Two trials demonstrated a reduction in wheal area after treatment with a second- or third-generation antihistamine compared with placebo (mean difference, -347.99 mm2; 95% CI, -489.43 to -206.54 mm2). Two trials demonstrated significant elimination of pruritus with second- or third-generation antihistamine treatment vs placebo (OR, 10.44; 95% CI, 4.39 to 24.84). All 4 studies assessed the tolerability of a second- or third-generation antihistamine vs placebo and found an increased rate of adverse events (OR, 3.04; 95% CI, 1.53 to 6.06), although the complaints were mild. CONCLUSIONS: The newer, less-sedating antihistamines seem to be effective in the treatment of ACU in terms of their ability to significantly reduce the presence of wheals and pruritus after cold exposure. These medications are usually well tolerated, with only mild adverse effects.

Harmonic moment dynamics in Laplacian growth.

Harmonic moments are integrals of integer powers of z=x+iy over a domain. Here, the domain is an exterior of a bubble of air growing in an oil layer between two horizontal closely spaced plates. Harmonic moments are a natural basis for such Laplacian growth phenomena because, unlike other representations, these moments linearize the zero surface tension problem [S. Richardson, J. Fluid Mech. 56, 609 (1972)], so that all moments except the lowest one (the area of the bubble) are conserved in time. In our experiments, we directly determine the harmonic moments and show that for nonzero surface tension, all moments (except the lowest one) decay in time rather than exhibiting the divergences of other representations. Further, we derive an expression that relates the derivative of the k(th) harmonic moment M(k) to measurable quantities (surface tension, viscosity, the distance between the plates, and a line integral over the contour encompassing the growing bubble). The laboratory observations are in good accord with the expression we derive for dM(k)/dt , which is proportional to the surface tension; thus in the zero surface tension limit, the moments (above k=0) are all conserved, in accord with Richardson's theory. In addition, from the measurements of the time evolution of the harmonic moments we obtain a value for the surface tension that is within 20% of the accepted value. In conclusion, our analysis and laboratory observations demonstrate that an interface dynamics description in terms of harmonic moments is physically realizable and robust.

Clinical and laboratory diagnosis of von Willebrand disease: a synopsis of the 2008 NHLBI/NIH guidelines.

Von Willebrand factor (VWF) mediates blood platelet adhesion and accumulation at sites of blood vessel injury, and also carries coagulation factor VIII (FVIII) that is important for generating procoagulant activity. Von Willebrand disease (VWD), the most common inherited bleeding disorder, affects males and females, and reflects deficiency or defects of VWF that may also cause decreased FVIII. It may also occur less commonly as an acquired disorder (acquired von Willebrand syndrome). This article briefly summarizes selected features of the March 2008 evidence-based clinical and laboratory diagnostic recommendations from the National Heart, Lung, and Blood Institute (NHLBI) Expert Panel for assessment for VWD or other bleeding disorders or risks. Management of VWD is also addressed in the NHLBI guidelines, but is not summarized here. The VWD guidelines are available at the NHLBI Web site (http://www.nhlbi.nih.gov/guidelines/vwd).

Results of a survey of biological drug and device industries inspected by FDA under the Team Biologics Program.

The Product Quality Research Institute, in conjunction with the Food and Drug Administration, conducted an anonymous, electronic survey of the biological products manufacturing industry inspected by Team Biologics, with emphasis in obtaining industry input on inspection and compliance aspects of program operations. Representatives from all of the product-specific manufacturing industries inspected under the Team Biologics Program responded to this survey (vaccines; fractionated plasma proteins and recombinant analogs; allergenics; therapeutics and in-vivo diagnostics; and in-vitro diagnostics, including blood grouping reagents). Data and written feedback was obtained regarding each firm's interactions and experiences of Team Biologics inspections at its facilities over the past three years. The three areas most impacted by Team Biologic inspections were "Production and Process Controls", "Failure Investigations" and "Facility / Equipment Controls". Overall assessment of the program was generally positive with 68% identifying a positive impact on the sites operations and 88% assessed the inspections as being conducted fairly. The findings and conclusions of this report will be utilized by the FDA to evaluate and further assess the impact of the Team Biologics Program and to implement any necessary changes. This report provides useful information to companies currently manufacturing licensed biologic products subject to Team Biologics inspections and also to those companies anticipating these inspections for future product manufacturing.

Fjords in viscous fingering: selection of width and opening angle.

Our experiments on viscous fingering of air into oil contained between closely spaced plates reveal two selection rules for the fjords of oil that separate fingers of air. (Fjords are the building blocks of solutions of the zero-surface-tension Laplacian growth equation.) Experiments in rectangular and circular geometries yield fjords with base widths lambda(c)/2, where lambda(c) is the most unstable wavelength from a linear stability analysis. Further, fjords open at an angle of 8.0 degrees +/- 1.0 degree. These selection rules hold for a wide range of pumping rates and fjord lengths, widths, and directions.

Tissue-resident macrophages are productively infected ex vivo by primary X4 isolates of human immunodeficiency virus type 1.

Infection of macrophages has been implicated as a critical event in the transmission and persistence of human immunodeficiency virus type 1 (HIV-1). Here, we explore whether primary X4 HIV-1 isolates can productively infect tissue macrophages that have terminally differentiated in vivo. Using immunohistochemistry, HIV-1 RNA in situ hybridization, and confocal immunofluorescence microscopy, we demonstrate that macrophages residing in human tonsil blocks can be productively infected ex vivo by primary X4 HIV-1 isolates. This challenges the model in which macrophage tropism is a key determinant of the selective transmission of R5 HIV-1 strains. Infection of tissue macrophages by X4 HIV-1 may be highly relevant in vivo and contribute to key events in HIV-1 pathogenesis.

Expression of the diffuse B-cell lymphoma family molecule SWAP-70 in human B-cell neoplasms: immunohistochemical study of 86 cases.

SWAP-70 is a recently discovered member of the Dbl (diffuse B-cell lymphoma) family of signal transduction molecules that is abundantly expressed in B cells. SWAP-70 mediates lipid second-messenger signals to the cytoskeletal-organizing GTPase Rac, functioning as a guanine-nucleotide exchange factor. SWAP-70 is strongly expressed in germinal center B cells, with low-level expression in resting B-cells. Expression of SWAP-70 in neoplastic B cells has not been described. We report the immunohistochemical expression of SWAP-70 in 86 B-cell neoplasms. SWAP-70 was strongly expressed in 59 of the 86 cases: 2 of 10 (20%) precursor B-cell lymphoblastic leukemias, 2 of 2 (100%) precursor B-cell lymphoblastic lymphomas, 2 of 4 (50%) mantle cell lymphomas, 7 of 9 (78%) Burkitt lymphomas, 9 of 9 (100%) diffuse large B-cell lymphomas, 8 of 8 (100%) follicular lymphomas, 6 of 6 (100%) nodular lymphocyte predominant Hodgkin lymphomas, 0 of 8 (0%) classic Hodgkin lymphomas, 12 of 13 (92%) chronic lymphocytic leukemias, 3 of 3 (100%) nodal marginal zone lymphomas, 5 of 5 (100%) extranodal marginal zone lymphomas, 1 of 2 (50%) splenic marginal zone lymphomas, 2 of 3 (66%) hairy cell leukemias, and 0 of 4 (0%) plasma cell neoplasms. All 4 T-cell lymphomas were nonreactive for SWAP-70: 0 of 3 peripheral T-cell lymphomas and 0 of 1 anaplastic large cell lymphoma. These results suggest that a spectrum of neoplastic B cells maintains activation of this signal transduction pathway. This is the first report of the expression of a Dbl family molecule in human lymphoma and leukemia tissues.

In vivo evolution of human immunodeficiency virus type 1 toward increased pathogenicity through CXCR4-mediated killing of uninfected CD4 T cells.

The destruction of the immune system by progressive loss of CD4 T cells is the hallmark of AIDS. CCR5-dependent (R5) human immunodeficiency virus type 1 (HIV-1) isolates predominate in the early, asymptomatic stages of HIV-1 infection, while CXCR4-dependent (X4) isolates typically emerge at later stages, frequently coinciding with a rapid decline in CD4 T cells. Lymphocyte killing in vivo primarily occurs through apoptosis, but the importance of apoptosis of HIV-1-infected cells relative to apoptosis of uninfected bystander cells is controversial. Here we show that in human lymphoid tissues ex vivo, apoptosis of uninfected bystander CD4 T cells is a major mechanism of lymphocyte depletion caused by X4 HIV-1 strains but is only a minor mechanism of depletion by R5 strains. Further, X4 HIV-1-induced bystander apoptosis requires the interaction of the viral envelope glycoprotein gp120 with the CXCR4 coreceptor on CD4 T cells. These results emphasize the contribution of bystander apoptosis to HIV-1 cytotoxicity and suggest that in association with a coreceptor switch in HIV disease, T-cell killing evolves from an infection-restricted stage to generalized toxicity that involves a high degree of bystander apoptosis.

Injection of human primary effusion lymphoma cells or associated macrophages into severe combined immunodeficient mice causes murine lymphomas.

The pathogenesis of immunodeficiency-associated lymphoma is poorly understood. During the past several years, numerous lines of evidence implicating a multistep process of malignant transformation, also known as sequential pathogenesis, have emerged. Tumor-associated macrophage production of specific lymphostimulatory products has been demonstrated and hypothesized to be central to this process. While attempting to establish primary effusion lymphoma in severe combined immunodeficient (SCID) mice, we discovered a potential model of murine lymphomagenesis consistent with the sequential pathogenesis model. This pathogenesis-based model of lymphoma could significantly impact the current thinking about posttransplantation and other immunodeficiency-related lymphoproliferative disorders. Human primary effusion lymphoma-derived CD14+ cell-injected SCID mice developed aggressive murine large cell lymphomas. Tumor cell preparations containing CD14 cells or isolated CD14 cells induced lymphoma/lymphoproliferative diseases in 74% (20 of 27) of injected SCID mice. No tumors were induced by tumor-associated CD3 cells (0 of 4), normal human macrophages (0 of 13), or a murine macrophage cell line (0 of 10). Human macrophages were detected in tumor-bearing animals up to 6 months postinjection in association with the murine T-cell tumors but were not detected in controls or unaffected animals. These observations are consistent with the macrophage-initiated sequential pathogenesis model of disease (M. S. McGrath et al., Acquir. Immune Defic. Syndr., 8: 379-385, 1995; M. S. McGrath et al., Infectious Causes of Cancer: Targets for Intervention, pp. 231-242, Totowa, NJ: Humana Press, 2000).