Adding a piece to the leaf epidermal cell shape puzzle

The jigsaw puzzle-shaped pavement cells in the leaf epidermis collectively function as a load-bearing tissue that controls organ growth. In this issue of Developmental Cell, Majda et al. (2017) shed light on how the jigsaw shape can arise from localized variations in wall stiffness between adjacent epidermal cells

Cellular requirements for PIN polar cargo clustering in Arabidopsis thaliana

Cell and tissue polarization is fundamental for plant growth and morphogenesis. The polar, cellular localization of Arabidopsis PIN‐FORMED (PIN) proteins is crucial for their function in directional auxin transport. The clustering of PIN polar cargoes within the plasma membrane has been proposed to be important for the maintenance of their polar distribution. However, the more detailed features of PIN clusters and the cellular requirements of cargo clustering remain unclear. Here, we characterized PIN clusters in detail by means of multiple advanced microscopy and quantification methods, such as 3D quantitative imaging or freeze‐fracture replica labeling. The size and aggregation types of PIN clusters were determined by electron microscopy at the nanometer level at different polar domains and at different developmental stages, revealing a strong preference for clustering at the polar domains. Pharmacological and genetic studies revealed that PIN clusters depend on phosphoinositol pathways, cytoskeletal structures and specific cell‐wall components as well as connections between the cell wall and the plasma membrane. This study identifies the role of different cellular processes and structures in polar cargo clustering and provides initial mechanistic insight into the maintenance of polarity in plants and other systems

Nintedanib Plus Pemetrexed/Cisplatin in Patients With Malignant Pleural Mesothelioma: Phase II Results From the Randomized, Placebo-Controlled LUME-Meso Trial

Purpose LUME-Meso is a phase II/III randomized, double-blind trial designed to assess efficacy and safety of nintedanib plus chemotherapy as first-line treatment of malignant pleural mesothelioma (MPM). Phase II results are reported here. Patients and Methods Chemotherapy-na¨ıve patients with unresectable, nonsarcomatoid MPM (Eastern Cooperative Oncology Group performance status 0 to 1), stratified by histology (epithelioid or biphasic), were randomly assigned in a 1:1 ratio to up to six cycles of pemetrexed and cisplatin plus nintedanib (200 mg twice daily) or placebo followed by nintedanib plus placebo monotherapy until progression. The primary end point was progression-free survival (PFS). Results Eighty-seven patients were randomly assigned. The median number of pemetrexed and cisplatin cycles was six; the median treatment duration for nintedanib was 7.8 months and 5.3 months for placebo. Primary PFS favored nintedanib (hazard ratio [HR], 0.56; 95% CI, 0.34 to 0.91; P = .017), which was confirmed in updated PFS analyses (HR, 0.54; 95% CI, 0.33 to 0.87; P = .010). A trend toward improved overall survival also favored nintedanib (HR, 0.77; 95% CI, 0.46 to 1.29; P = .319). Benefit was evident in epithelioid histology, with a median overall survival gain of 5.4 months (HR, 0.70; 95% CI, 0.40 to 1.21; P = .197; median [nintedanib v placebo], 20.6 months v 15.2 months) and median PFS gain of 4.0 months (HR, 0.49; 95% CI, 0.30 to 0.82; P = .006; median [nintedanib v placebo], 9.7 v 5.7 months). Neutropenia was the most frequent grade $ 3 adverse event (AE; nintedanib 43.2% v placebo 12.2%); rates of febrile neutropenia were low (4.5% in nintedanib group v 0% in placebo group). AEs leading to discontinuation were reported in 6.8% of those receiving nintedanib versus 17.1% of those in the placebo group. Conclusion Addition of nintedanib to pemetrexed plus cisplatin resulted in PFS improvement. AEs were manageable. The clinical benefit was evident in patients with epithelioid histology. The confirmatory phase III part of the study is ongoing

Phase I dose escalation study of BI 836826 (CD37 antibody) in patients with relapsed or refractory B-cell non-Hodgkin lymphoma

BI 836826 is a chimeric immunoglobulin G1 antibody targeting CD37, a tetraspanin transmembrane protein predominantly expressed on normal and malignant B cells. This phase I, open-label study used a modified 3 + 3 design to evaluate the safety, maximum tolerated dose (MTD), pharmacokinetics, and preliminary activity of BI 836826 in patients with relapsed/refractory B cell non-Hodgkin lymphoma (NHL; NCT01403948). Eligible patients received up to three courses comprising an intravenous infusion (starting dose: 1 mg) once weekly for 4 weeks followed by an observation period of 27 (Course 1, 2) or 55 days (Course 3). Patients had to demonstrate clinical benefit before commencing treatment beyond course 2. Forty-eight patients were treated. In the dose escalation phase (1-200 mg) involving 37 Caucasian patients, the MTD was 100 mg. Dose-limiting toxicities occurred in four patients during the MTD evaluation period, and included stomatitis, febrile neutropenia, hypocalcemia, hypokalemia, and hypophosphatemia. The most common adverse events were neutropenia (57%), leukopenia (57%), and thrombocytopenia (41%), and were commonly of grade 3 or 4. Overall, 18 (38%) patients experienced infusion-related reactions, which were mostly grade 1 or 2. Preliminary evidence of anti-tumor activity was seen; three patients responded to treatment, including one complete remission in a Korean patient with diffuse large B cell lymphoma. BI 836826 plasma exposure increased more than proportionally with increasing doses. BI 836826 demonstrated preliminary activity; the most frequent adverse events were hematotoxicity and infusion-related reactions which were manageable after amending the infusion schedule. Although BI 856826 will not undergo further clinical development, these results confirm CD37 as a valid therapeutic target in B cell NHL

Multi-tier Loyalty Programs to Stimulate Customer Engagement

Customers differ in their purchase behavior, profitability, attitude toward the firm, and so on. These differences between customers have led to numerous firms introducing multi-tier loyalty programs. A multi-tier loyalty program explicitly distinguishes between customers by means of hierarchical tiers (e.g. Silver, Gold, Platinum) and assigns customers to different tiers based on their past purchase behavior. Next, customers in different tiers are provided varying levels of tangible rewards and intangible benefits, which are potentially powerful instruments to stimulate customer engagement. In this chapter, we focus on the design and effectiveness of such multi-tier loyalty programs. Building on loyalty program and customer prioritization research, we discuss whether, why, and how multi-tier loyalty programs are effective (or not) in influencing customer behavior, thereby enhancing customer engagement and financial performance