Effect of an interactive, educational app about venous thromboembolism and anticoagulation on patient satisfaction: A randomized controlled trial.

BACKGROUND: Adequate patient education is essential for patients to engage in shared decision-making when deciding to stop or continue anticoagulation after 3 months for venous thromboembolism (VTE). Our objectives were to evaluate the effect of an interactive, educational app on patients' level of satisfaction with information, perceived level of knowledge, decisional conflict and extent of shared decision-making when deciding on treatment duration of VTE. MATERIALS AND METHODS: This randomized controlled trial in 1 academic and 3 general Dutch hospitals included adult patients diagnosed with VTE without malignancy or prolonged anticoagulation for other indications. Patients were randomized in 1:1 ratio to receive the app (intervention group) in addition to hospital-specific standard of care. The app, created for this study, contains information on VTE and anticoagulation on an interactive timeline. In the week preceding the consultation when treatment duration is decided, patients were provided with daily videos using push notifications. Outcomes were assessed through self-reported questionnaires at baseline, 1-2 days before and 1 day after consultation. Data were analyzed using t-tests and linear mixed models for repeated measurements. RESULTS: Data of 56 patients were analyzed (mean age 57 ± 13; 27% female). On a numeric rating scale from 0 to 10, patients who received the app were 0.9 points (95%CI 0.0-1.7; p 0.04) more satisfied with the provided information. Patients who received the app experienced significantly less decisional conflict. No differences in other outcomes were observed. CONCLUSIONS: An educational app about VTE and anticoagulation increases patients' satisfaction and reduces decisional conflict when deciding on treatment duration of VTE. This study was registered in the Netherlands Trial Register (NL7037).

Dalteparin and anti-Xa: a complex interplay of therapeutic drug monitoring.

BACKGROUND: Monitoring low-molecular-weight heparins is generally not required. However, guidelines advise to monitor anti-Xa levels in patients with renal insufficiency or a BMI above 50, and in pregnancy. Measuring anti-Xa levels is a complex challenge since sampling should be performed three to five hours after subcutaneous injection and after steady state concentrations have been reached. Strict compliance is pivotal for justified dose adjustments. OBJECTIVES: We questioned compliance to our protocol and performed this study to explore that. METHODS: This retrospective cohort study included patients ≥ 18 years receiving therapeutic dalteparin in a Dutch academic medical centre. Patients with a first anti-Xa level measured between February 23rd and December 30th, 2017 were selected. According to our local guideline, monitoring anti-Xa activity is indicated in patients on therapeutic doses of dalteparin who are pregnant, morbidly obese (BMI > 50), or have renal insufficiency (clearance < 60 ml/min). Accurate sampling was defined as measuring levels after at least three injections (after which a patient may reach steady state) and then four hours after the injection with dalteparin. The frequency of compliance to our protocol was assessed. RESULTS: We included 158 patients with 396 anti-Xa levels, of which 41% (65/158) of all first anti-Xa levels were drawn without appropriate indication. Almost half, 48% (211/396), were sampled incorrectly and 25% of these (53/211) were followed by a dose adjustment. In total, 74% (293/396) of the samples were not indicated or were taken at the wrong time. CONCLUSIONS: Monitoring anti-Xa levels is a complex clinical challenge. This study showed that non-compliance with recommendations for anti-Xa monitoring was high, often resulting in unjustified dose adjustments.

Rationale for catheter-based therapies in acute pulmonary embolism.

Pulmonary embolism (PE) is a common disease resulting in significant morbidity and mortality. High-risk features of PE are hypotension or shock, and early reperfusion is warranted to unload the strained right ventricle and improve clinical outcomes. Currently, systemic thrombolysis (ST) is the standard of care but is associated with bleeding complications. Catheter-based therapies (CDT) have emerged as a promising alternative having demonstrated to be equally effective while having a lower risk of bleeding. Several CDT are currently available, some combining mechanical properties with low-dose thrombolytics. Recent guidelines suggest that CDT may be considered in patients with high-risk PE who have high bleeding risk, after failed ST, or in patients with rapid haemodynamic deterioration as bail-out before ST can be effective, depending on local availability and expertise. In haemodynamically stable patients with right ventricular (RV) dysfunction (intermediate-risk PE), CDT may be considered if clinical deterioration occurs after starting anticoagulation and relative contraindications for ST due to bleeding risk exist. Decision on treatment modality should follow a risk-benefit analysis on a case by case base, weighing the risk of PE-related complications; i.e. haemodynamic deterioration vs. bleeding. As timely initiation of treatment is warranted to prevent early mortality, bleeding risk factors should be assessed at an early stage in all patients with acute PE and signs of RV dysfunction. To ensure optimal management of complex cases of PE and assess a potential CDT strategy, a multidisciplinary approach is recommended. A dedicated Pulmonary Embolism Response Team may optimize this process.

Efficient microfluidic negative enrichment of circulating tumor cells in blood using roughened PDMS.

Efficient isolation strategies not based on epithelial biomarker expression are required to enable non-biased enrichment of circulating tumor cells (CTCs). CTCs undergoing epithelial-mesenchymal transition (EMT) may be prognostically relevant, and importantly are not detected with conventional epithelial based approaches such as CellSearch®. A method for the non-biased isolation of cancer cells within a peripheral blood sample utilizing microfluidic mixing PDMS devices functionalized with anti-CD45 is reported. The introduction of micro and nanoscale roughness using a single step treatment with sulfuric acid significantly increases the binding yield of white blood cells (WBCs) to the anti-CD45 conjugated surfaces. Up to 99.99% WBC depletion is achieved with a tumor cell recovery yield of 50%. This high level of CTC enrichment is expected to facilitate the detailed characterization of CTCs using for instance, imaging flow cytometry as demonstrated here.

Exocytosis is impaired in mucopolysaccharidosis IIIA mouse chromaffin cells.

Mucopolysaccharidosis IIIA (MPS IIIA) is a lysosomal storage disorder caused by a deficiency in the activity of the lysosomal hydrolase, sulphamidase, an enzyme involved in the degradation of heparan sulphate. MPS IIIA patients exhibit progressive mental retardation and behavioural disturbance. While neuropathology is the major clinical problem in MPS IIIA patients, there is little understanding of how lysosomal storage generates this phenotype. As reduced neuronal communication can underlie cognitive deficiencies, we investigated whether the secretion of neurotransmitters is altered in MPS IIIA mice; utilising adrenal chromaffin cells, a classical model for studying secretion via exocytosis. MPS IIIA chromaffin cells displayed heparan sulphate storage and electron microscopy revealed large electron-lucent storage compartments. There were also increased numbers of large/elongated chromaffin granules, with a morphology that was similar to immature secretory granules. Carbon fibre amperometry illustrated a significant decrease in the number of exocytotic events for MPS IIIA, when compared to control chromaffin cells. However, there were no changes in the kinetics of release, the amount of catecholamine released per exocytotic event, or the amount of Ca(2+) entry upon stimulation. The increased number of large/elongated granules and reduced number of exocytotic events suggests that either the biogenesis and/or the cell surface docking and fusion potential of these vesicles is impaired in MPS IIIA. If this also occurs in central nervous system neurons, the reduction in neurotransmitter release could help to explain the development of neuropathology in MPS IIIA.

Differential leucocyte subpopulation analysis of leucodepleted red cell products.

Donor leucocytes are responsible for many adverse transfusion effects. Clinical reactions may be attributed to specific leucocyte subsets. In this study leucocyte subpopulations were identified and quantified pre- and post-leucodepletion by integral filtration using novel Optipac(R) configurations incorporating either WBF-1 (Pall Medsep) or RS2000 (Asahi) whole blood filters. Leucocytes were analysed by flow cytometry using direct, four-colour, membrane immunofluorescence with monoclonal antibodies specific for CD 3, 14, 16, 19 and 45. Filtration reduced the leucocyte load by 3-4 log10, consistently giving products with < 2 cells microL-1. Subset distributions were also affected with the proportion of neutrophils and monocytes increased and the lymphocyte/monocyte ratio inverted. These effects were independent of the preprocessing hold conditions, filter used and buffy coat (BC) removal. All filtered red cell products contained 75-80% neutrophils, 16-20% monocytes and 2-7% lymphocytes. Results presented here demonstrate that whole blood filtration, and BC removal, significantly reduce the content and substantially alter the subpopulation distribution of the donor leucocytes remaining in leucodepleted red cell products.

Reversal of resistance in multidrug resistance protein (MRP1)-overexpressing cells by LY329146.

The benzothiophene LY329146 reverses the drug resistance phenotype in multidrug resistance protein (MRP1)-overexpressing cells when dosed in combination with MRP1-associated oncolytics doxorubicin and vincristine. Additionally, LY329146 inhibited MRP1-mediated uptake of the MRP1 substrate LTC4 into membrane vesicles prepared from MRP1-overexpressing cells.

Evaluation of plasma and red cells obtained after leucocyte depletion of whole blood.

We evaluated whole blood integral filtration to produce leucocyte-depleted red cells and plasma by using the WBF1 whole blood filter (Pall Medsep). Whole blood units were filtered after either warm (2-4 h at room temperature) or cold (12-24 h at 4 degrees C) holds. Filtered and control units were processed using either a bottom-and-top or top-top method. Red cells were tested weekly for 6 weeks, and plasma 3 monthly for 12 months. All filtered red-cell packs contained < 5 x 10(6) leucocytes/unit with 71 of 72 containing < 1 x 10(6) leucocytes/unit. No clinically significant differences in red-cell storage parameters were seen, although haemolysis was less and pO2/pCO2 values were better maintained in filtered units. Plasma units contained < 2.5 x 10(3) leucocytes/unit with no significant loss of factor VIII except in the warm hold units processed by the top-top method. There was no evidence of complement or coagulation activation with significant removal of preformed C3a in cold hold units. Plasma storage parameters were maintained at control levels for 12 months.

Effect of modulators on the ATPase activity and vanadate nucleotide trapping of human P-glycoprotein.

P-Glycoprotein (Pgp) is responsible for the energy-dependent efflux of many natural product oncolytics. Overexpression of Pgp may result in multidrug resistance (MDR). Modulators can block Pgp efflux and sensitize multidrug resistant cells to these oncolytics. To study the interaction of modulators with Pgp, Pgp-ATPase activity was examined, using plasma membranes isolated from the multidrug-resistant cell line CEM/VLB100. A survey of modulators indicated that verapamil, trifluoperazine, and nicardipine stimulated ATPase activity by 1.3- to 1.8-fold, whereas two others, trimethoxybenzoylyohimbine (TMBY) and vindoline, had no effect. Further evaluation showed that TMBY completely blocked the stimulation by verapamil of ATPase activity by competitive inhibition, with a Ki of 2.1 microM. When the effects of these two modulators on the formation of the enzyme-nucleotide complex important in the catalytic cycle were examined, verapamil increased the amount of vanadate-trapped 8-azido-[alpha-32P]ATP bound to Pgp by two-fold, whereas TMBY had no effect. Moreover, TMBY blocked the verapamil stimulation of vanadate-8-azido-[alpha-32P]ATP. Together, these data indicate that verapamil and TMBY bind to Pgp at a common site or overlapping sites, but only verapamil results in enhanced Pgp-ATP hydrolysis and formation of the vanadate-nucleotide-enzyme complex.

Structure-activity relationships of selective estrogen receptor modulators: modifications to the 2-arylbenzothiophene core of raloxifene.

The 2-arylbenzothiophene raloxifene, 1, is a selective estrogen receptor modulator which is currently under clinical evaluation for the prevention and treatment of postmenopausal osteoporosis. A series of raloxifene analogs which contain modifications to the 2-arylbenzothiophene core have been prepared and evaluated for the ability to bind to the estrogen receptor and inhibit MCF-7 breast cancer cell proliferation in vitro. Their ability to function as tissue-selective estrogen agonists in vivo has been assayed in a short-term, ovariectomized (OVX) rat model with end points of serum cholesterol lowering, uterine weight gain, and uterine eosinophil peroxidase activity. These studies have demonstrated that (1) the 6-hydroxy and, to a lesser extent, the 4'-hydroxy substituents of raloxifene are important for receptor binding and in vitro activity, (2) small, highly electronegative 4'-substituents such as hydroxy, fluoro, and chloro are preferred both in vitro and in vivo, (3) increased steric bulk at the 4'-position leads to increased uterine stimulation in vivo, and (4) additional substitution of the 2-aryl moiety is tolerated while additional substitution at the 4-, 5-, or 7-position of the benzothiophene results in reduced biological activity. In addition, compounds in which the 2-aryl group is replaced by alkyl, cycloalkyl, and naphthyl substituents maintain a profile of in vitro and in vivo biological activity qualitatively similar to that of raloxifene. Several novel structural variants including 2-cyclohexyl, 2-naphthyl, and 6-carbomethoxy analogs also demonstrated efficacy in preventing bone loss in a chronic OVX rat model of postmenopausal osteopenia, at doses of 0.1-10 mg/kg.

Pharmacological characterization of LY335979: a potent cyclopropyldibenzosuberane modulator of P-glycoprotein.

The above data indicate that LY335979 displays the following characteristics of an 'ideal modulator' of Pgp-mediated multidrug resistance: high affinity binding to Pgp, high potency for in vitro reversal of drug resistance, high therapeutic index (activity was demonstrated at doses ranging from 1-30 mg/kg) observed in in vivo antitumor efficacy experiments, and a lack of pharmacokinetic interactions that alter the plasma concentration of coadministered oncolytic agents. These desirable features strongly suggest that LY335979 is an exciting new clinical agent to test the hypothesis that inhibition of P-glycoprotein activity will result in reversal of multidrug resistance in human tumors.

Molecular determinants of tissue selectivity in estrogen receptor modulators.

Interaction of the estrogen receptor/ligand complex with a DNA estrogen response element is known to regulate gene transcription. In turn, specific conformations of the receptor-ligand complex have been postulated to influence unique subsets of estrogen-responsive genes resulting in differential modulation and, ultimately, tissue-selective outcomes. The estrogen receptor ligands raloxifene and tamoxifen have demonstrated such tissue-specific estrogen agonist/antagonist effects. Both agents antagonize the effects of estrogen on mammary tissue while mimicking the actions of estrogen on bone. However, tamoxifen induces significant stimulation of uterine tissue whereas raloxifene does not. We postulate that structural differences between raloxifene and tamoxifen may influence the conformations of their respective receptor/ligand complexes, thereby affecting which estrogen-responsive genes are modulated in various tissues. These structural differences are 4-fold: (A) the presence of phenolic hydroxyls, (B) different substituents on the basic amine, (C) incorporation of the stilbene moiety into a cyclic benzothiophene framework, and (D) the imposition of a carbonyl "hinge" between the basic amine-containing side chain and the olefin. A series of raloxifene analogs that separately exemplify each of these differences have been prepared and evaluated in a series of in vitro and in vivo assays. This strategy has resulted in the development of a pharmacophore model that attributes the differences in effects on the uterus between raloxifene and tamoxifen to a low-energy conformational preference imparting an orthogonal orientation of the basic side chain with respect to the stilbene plane. This three-dimensional array is dictated by a single carbon atom in the hinge region of raloxifene. These data indicate that differences in tissue selective actions among benzothiophene and triarylethylene estrogen receptor modulators can be ascribed to discrete ligand conformations.

A structure-function relationship among reserpine and yohimbine analogues in their ability to increase expression of mdr1 and P-glycoprotein in a human colon carcinoma cell line.

We previously showed that there is a structure-function relationship among reserpine and yohimbine analogues in their ability to inhibit the function of P-glycoprotein (P-gp) and reverse multidrug resistance (MDR). Because some P-gp inhibitors (e.g., verapamil and nifedipine) can increase mdr1 and P-gp expression in human colon carcinoma cell lines, we used our reserpine/yohimbine analogues to determine whether there was a structural requirement for this induction. We found that 10 microM reserpine increased both mdr1 and P-gp expression by 4-10-fold in 48 hr in a human colon carcinoma cell line that expresses moderate levels of mdr1 (LS180-Ad50) but not in several other cell lines that expressed no mdr1. The reserpine/yohimbine analogues rescinnamine, trimethoxybenzoylyohimbine, and LY191401 (compound G), all of which contain the three structural elements used to describe the MDR pharmacophore, also increased both mdr1 and P-gp expression significantly. Despite some exceptions, we found that there was a good association between the ability of these analogues to induce mdr1 and P-gp expression and their ability to reverse vinblastine and doxorubicin resistance, revealing a structure-function relationship for this phenomenon. The increased P-gp expressed by these cells appeared to be functional, as determined by flow cytometric detection of rhodamine 123 retention. The increased expression was suppressed by 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole, an RNA synthesis inhibitor, whereas the protein synthesis inhibitor cycloheximide enhanced the expression several-fold, suggesting that induction of mdr1 by these analogues is regulated at both the transcriptional and post-transcriptional levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Estrogen synthetase inhibitors. 2. Comparison of the in vitro aromatase inhibitory activity for a variety of nitrogen heterocycles substituted with diarylmethane or diarylmethanol groups.

The preparation and in vitro aromatase inhibitory activity of a wide variety of heterocyclic (4,4'-dichlorodiphenyl)methanes and -methanols are described. The choice of the two diaryl-bearing moieties as a vehicle for the evaluation of the heterocycles was made by the comparison of series of imidazole and pyridine-derived compounds with similar pyrimidine compounds reported previously. A structural model for the most active compounds is also presented. The activity of a related series of the compounds which contain two heterocyclic moieties was found to be consistent with the model. Many of the compounds evaluated, including representatives of the pyridine, imidazole, pyrimidine, pyrazole, triazole, thiazole, and isothiazole classes, exhibit EC50 potencies for aromatase inhibition at low nanomolar levels. These compounds are at least as potent as other nonsteroidal aromatase inhibitors reported previously.

Structural characteristics of compounds that modulate P-glycoprotein-associated multidrug resistance.

Multidrug resistance is mediated by a membrane-bound protein, P-gp, that functions as an energy dependent efflux system to reduce the intracellular concentration of anticancer drugs by binding to these drugs and actively exporting them from the cell. Compounds that interact with P-gp and compete with anticancer drug binding modulate the degree of drug resistance and therefore enhance the cytotoxicity of anticancer drugs against the resistant cell. Effective modulators share certain physical and chemical properties including octanol/water partitioning and molecular size, but the physical properties of size and shape seem to correlate best with modulator effectiveness. Using a photoactivatable analog of vinblastine as a probe, together with a semi-synthetic series of structurally homologous reserpine and yohimbine analogs, the need for two planar aromatic domains and a basic nitrogen atom was established within the structural context of these compounds. The use of three-dimensional comparisons was extended to examine important structural features in other modulator types such as the condensed-ring aromatics. This approach indicates that structural similarities between different classes of compounds are present in compounds recognized by the MDR phenotype. These studies emphasize the importance of a ligand-receptor relationship for modulators of MDR, and begin to define the P-gp-binding pharmacophore. It is likely that this approach will be useful in directing the de novo synthesis of compounds that modulate MDR and help to further define the requirements for molecular recognition by this system.

Essential features of the P-glycoprotein pharmacophore as defined by a series of reserpine analogs that modulate multidrug resistance.

We have shown previously that reserpine is an effective "modulator" of P-glycoprotein-associated multidrug resistance (MDR). In addition to enhancing drug cytotoxicity in our multidrug-resistant human leukemia cell line, CEM/VLB100, reserpine strongly competes with a photoactivatible analog of vinblastine, N-(p-azido-3-[125I]iodosalicyl)-N'-(beta-aminoethyl)vindesine, for binding to P-glycoprotein. We also demonstrated previously that there are three substructural domains present in many compounds that modulate P-glycoprotein-associated MDR: a basic nitrogen atom and two planar aromatic rings. In the present study, we wished to test more rigorously the hypothesis that not only are these domains necessary for modulators of MDR but also they must exist in an appropriate conformation. Reserpine is a modulator of MDR in which these domains are present in a well-defined conformation. Accordingly, we prepared eight compounds that vary the spatial orientation of these domains, using either naturally occurring reserpine or yohimbine as chemical templates. When tested for their ability to enhance the cytotoxic activity of natural product antitumor drugs in CEM/VLB100 cells, five compounds that retained the pendant benzoyl function in an appropriate spatial orientation all modulated MDR. By contrast, compounds lacking this moiety failed to do so. These active modulators competed strongly with the 125I-labeled vinblastine analog for binding to P-glycoprotein in plasma membrane vesicles prepared from these cells. Conformational analysis using molecular mechanics revealed the structural similarities of the active modulators. Our results support the hypothesis that the relative disposition of aromatic rings and basic nitrogen atom is important for modulators of P-glycoprotein-associated MDR, and they suggest a ligand-receptor relationship for these agents. These results also provide direction for the definition of an MDR "pharmacophore."