ALBERT

Description: Author Posting. © American Meteorological Society, 2018. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Climate 31 (2018): 7565-7581, doi:10.1175/JCLI-D-18-0108.1.

Description: There is mounting evidence that the width of the tropics has increased over the last few decades, but there are large differences in reported expansion rates. This is, likely, in part due to the wide variety of metrics that have been used to define the tropical width. Here we perform a systematic investigation into the relationship among nine metrics of the zonal-mean tropical width using preindustrial control and abrupt quadrupling of CO2 simulations from a suite of coupled climate models. It is shown that the latitudes of the edge of the Hadley cell, the midlatitude eddy-driven jet, the edge of the subtropical dry zones, and the Southern Hemisphere subtropical high covary interannually and exhibit similar long-term responses to a quadrupling of CO2. However, metrics based on the outgoing longwave radiation, the position of the subtropical jet, the break in the tropopause, and the Northern Hemisphere subtropical high have very weak covariations with the above metrics and/or respond differently to increases in CO2 and thus are not good indicators of the expansion of the Hadley cell or subtropical dry zone. The differing variability and responses to increases in CO2 among metrics highlights that care is needed when choosing metrics for studies of the width of the tropics and that it is important to make sure the metric used is appropriate for the specific phenomena and impacts being examined.

Description: DW acknowledges support from NSF AGS-1403676.

Description: 2019-02-08

Description: Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Bulletin of the American Meteorological Society 101(6), (2020): E897-E904, doi:10.1175/BAMS-D-19-0047.1.

Description: Over the past 15 years, numerous studies have suggested that the sinking branches of Earth’s Hadley circulation and the associated subtropical dry zones have shifted poleward over the late twentieth century and early twenty-first century. Early estimates of this tropical widening from satellite observations and reanalyses varied from 0.25° to 3° latitude per decade, while estimates from global climate models show widening at the lower end of the observed range. In 2016, two working groups, the U.S. Climate Variability and Predictability (CLIVAR) working group on the Changing Width of the Tropical Belt and the International Space Science Institute (ISSI) Tropical Width Diagnostics Intercomparison Project, were formed to synthesize current understanding of the magnitude, causes, and impacts of the recent tropical widening evident in observations. These working groups concluded that the large rates of observed tropical widening noted by earlier studies resulted from their use of metrics that poorly capture changes in the Hadley circulation, or from the use of reanalyses that contained spurious trends. Accounting for these issues reduces the range of observed expansion rates to 0.25°–0.5° latitude decade‒1—within the range from model simulations. Models indicate that most of the recent Northern Hemisphere tropical widening is consistent with natural variability, whereas increasing greenhouse gases and decreasing stratospheric ozone likely played an important role in Southern Hemisphere widening. Whatever the cause or rate of expansion, understanding the regional impacts of tropical widening requires additional work, as different forcings can produce different regional patterns of widening.

Description: We thank U.S. CLIVAR and ISSI for funding the two working groups. We thank all members of the working groups for helpful discussions, and the U.S. CLIVAR and ISSI offices and their sponsoring agencies (NASA, NOAA, NSF, DOE, ESA, Swiss Confederation, Swiss Academy of Sciences, and University of Bern) for supporting these groups and activities.

Description: Here, we demonstrate a novel, direct-acting, and synergistic role for 3 hematopoietic stem cell cytokines: stem cell factor, interleukin-3, and stromal derived factor-1α, in controlling human endothelial cell (EC) tube morphogenesis, sprouting, and pericyte-induced tube maturation under defined serum-free conditions in 3-dimensional matrices. Angiogenic cytokines such as vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF) alone or VEGF/FGF combinations do not support these responses. In contrast, VEGF and FGF prime EC responses to hematopoietic cytokines via up-regulation of c-Kit, IL-3Rα, and C-X-C chemokine receptor type 4 from either human ECs or embryonic quail vessel explants. In support of these findings, EC Runx1 is demonstrated to be critical in coordinating vascular morphogenic responses by controlling hematopoietic cytokine receptor expression. Combined blockade of hematopoietic cytokines or their receptors in vivo leads to blockade of developmental vascularization in quail embryos manifested by vascular hemorrhage and disrupted vascular remodeling events in multiple tissue beds. This work demonstrates a unique role for hematopoietic stem cell cytokines in vascular tube morphogenesis and sprouting and further demonstrates a novel upstream priming role for VEGF and FGF to facilitate the action of promorphogenic hematopoietic cytokines.

Description: Here we show that endothelial cells (EC) require matrix type 1-metalloproteinase (MT1-MMP) for the formation of lumens and tube networks in 3-dimensional (3D) collagen matrices. A fundamental consequence of EC lumen formation is the generation of vascular guidance tunnels within collagen matrices through an MT1-MMP-dependent proteolytic process. Vascular guidance tunnels represent a conduit for EC motility within these spaces (a newly remodeled 2D matrix surface) to both assemble and remodel tube structures. Interestingly, it appears that twice as many tunnel spaces are created than are occupied by tube networks after several days of culture. After tunnel formation, these spaces represent a 2D migratory surface within 3D collagen matrices allowing for EC migration in an MMP-independent fashion. Blockade of EC lumenogenesis using inhibitors that interfere with the process (eg, integrin, MMP, PKC, Src) completely abrogates the formation of vascular guidance tunnels. Thus, the MT1-MMP-dependent proteolytic process that creates tunnel spaces is directly and functionally coupled to the signaling mechanisms required for EC lumen and tube network formation. In summary, a fundamental and previously unrecognized purpose of EC tube morphogenesis is to create networks of matrix conduits that are necessary for EC migration and tube remodeling events critical to blood vessel assembly.

Description: We show that endothelial cell (EC)–generated vascular guidance tunnels (ie, matrix spaces created during tube formation) serve as conduits for the recruitment and motility of pericytes along EC ablumenal surfaces to facilitate vessel maturation events, including vascular basement membrane matrix assembly and restriction of EC tube diameter. During quail development, pericyte recruitment along microvascular tubes directly correlates with vascular basement membrane matrix deposition. Pericyte recruitment to EC tubes leads to specific induction of fibronectin and nidogen-1 (ie, matrix-bridging proteins that link together basement membrane components) as well as perlecan and laminin isoforms. Coincident with these events, up-regulation of integrins, α5β1, α3β1, α6β1, and α1β1, which bind fibronectin, nidogens, laminin isoforms, and collagen type IV, occurs in EC-pericyte cocultures, but not EC-only cultures. Integrin-blocking antibodies to these receptors, disruption of fibronectin matrix assembly, and small interfering RNA suppression of pericyte tissue inhibitor of metalloproteinase (TIMP)-3 (a known regulator of vascular tube stabilization) all lead to decreased EC basement membrane, resulting in increased vessel lumen diameter, a key indicator of dysfunctional EC-pericyte interactions. Thus, pericyte recruitment to EC-lined tubes during vasculogenesis is a stimulatory event controlling vascular basement membrane matrix assembly, a fundamental maturation step regulating the transition from vascular morphogenesis to stabilization.

Description: Abstract 1842 Perifosine (Keryx Biopharmaceuticals) is an oral alkylphospholipid that has been shown to have clinical activity in multiple myeloma and Waldenstrom's macroglobulinemia. Pre-clinical data suggest that its activity is due to inhibition of the Akt signal transduction pathway. The Akt pathway is known to be important for viability in CLL, another B-cell malignancy. Therefore, we investigated the in vitro activity of perifosine in freshly isolated primary CLL cells. CLL patients at the Duke University and Durham VA Medical Centers were enrolled in an IRB-approved research protocol for blood sample collection. CLL cells were negatively selected using the RosetteSep B-cell enrichment cocktail (StemCell Technologies) and a ficoll-Hypaque gradient. This method yields greater than 95% purity of malignant lymphocytes, determined by flow cytometry. Prognostic markers such as IgVH mutation status, CD38 and ZAP70 expression, and interphase cytogenetics were determined. We found the 50% effective dose (ED50) of perifosine for inducing cytotoxicity in CLL cells after a three-day incubation using the MTS colorimetric assay to be 510 nM (n = 29, range 120 – 1540 nM). CLL cells were obtained from patients with generally poor prognostic markers: 52% CD38+, 93% ZAP70+, 78% IgVH unmutated, 42% 17p deletion, 8% 11q deletion, 27% trisomy 12, 12% normal, and 12% 13q deletion as a sole abnormality. There were no statistical differences in ED50 between cells obtained from patients in high or low risk prognostic groups. Perifosine induced apoptosis in a dose- and time-dependent manner, measured by Annexin V and PI staining (n = 4). Based upon these pre-clinical results, we initiated a phase II study of perifosine (50 mg orally, twice daily) in relapsed or refractory CLL/small lymphocytic lymphoma (SLL) (NCT00873457). The primary objective of this study is to assess the response rate at 3 and 6 months of perifosine treatment in patients with relapsed or refractory CLL/SLL. Secondary objectives are to monitor toxicity, evaluate overall survival, progression-free survival and response duration, and perform laboratory correlates. Early interim results of this study are presented. Since trial initiation in September 2009, 13 patients have been enrolled. Nine patients had Rai stage III/IV disease at the time of therapy, and 4 patients were fludarabine-refractory. Patients had extensive prior treatment (median 4, range 1 – 11). Many patients had high-risk prognostic features: 9/11 IgVH unmutated, 10/13 CD38+, and 11/13 ZAP70+. Evaluation of interphase and metaphase cytogenetics demonstrated 4 patients with 17p deletion, two with 11q deletion, 2 with trisomy 12, 4 normal, and 4 with other complex cytogenetic anomalies. Of 12 patients who began therapy, 5 patients withdrew from the study prior to 3 months, 6 patients received at least 3 months of therapy, and 1 patient completed 6 months of therapy. Of the patients who received at least 3 months of therapy, there were 5 patients with stable disease, and one patient with partial response, using iwCLL response criteria. Grade 3/4 toxicities included anemia (n=2), fatigue (n=2), dehydration (n=1), febrile neutropenia (n=1), hyperbilirubinemia (n=1), hyponatremia (n=1), cough (n=1), and dyspnea (n=1). One patient required a dose reduction to 50 mg daily and two patients required dose delays due to toxicities. In conclusion, perifosine has potent in vitro activity against primary CLL cells. Preliminary results of this ongoing phase II study of oral perifosine in relapsed or refractory CLL/SLL demonstrate mostly disease stabilization in a group of very high-risk patients and an acceptable toxicity profile. Completion of this clinical study is necessary to determine if perifosine monotherapy has a potential role in the treatment of CLL/SLL. Disclosures: Sportelli: Keryx Biopharmaceutical: Employment, Equity Ownership. Weinberg:Keryx Biopharmaceuticals: Research Funding.

Description: Introduction The current standard to assess chemotherapy tolerability relies on patient self-reporting. However, as the sole mechanism of managing symptom burden, this may be inconsistent and fraught with bias. Mobile wearable health devices have the ability to monitor and aggregate objective activity and sleep data over long periods of time, but have not been systematically used in the oncology clinic. The aim of the study was to assess whether the use of mobile wearable technology establishes patterns of "sleep" and "wake" states in newly diagnosed Multiple Myeloma (NDMM) patients receiving therapy, and whether these patterns differ over time. Methods Patients presenting to the myeloma clinic at Memorial Sloan Kettering Cancer Center (MSKCC) with a new diagnosis of Multiple Myeloma and smart phone or tablet (iOS or Android) compatible with the Garmin Vivofit device were offered to participate in a mobile wearable bio-monitoring study. All eligible participants were required to receive primary chemotherapy treatment at a MSKCC facility. Treatment was determined by physician. NDMM patients were assigned to one of two cohorts (20 in each; Cohort A - patients

Description: Natural killer (NK) cells secrete lytic granules to directly kill virus-infected or transformed cells and secrete cytokines to communicate with other cells. Three-dimensional super-resolved images of F-actin, lytic granules, and IFN-γ in primary human NK cells stimulated through different activating receptors reveal that both IFN-γ and lytic granules accumulated in domains where the periodicity of the cortical actin mesh at the synapse opened up to be penetrable. Ligation of some activating receptors alone (eg, CD16 or NKG2D) was sufficient to increase the periodicity of the actin mesh, but surprisingly, ligation of others (eg, NKp46 or CD2) was not sufficient to induce cortical actin remodeling unless LFA-1 was coligated. Importantly, influenza virus particles that can be recognized by NK cells similarly did not open the actin mesh but could if LFA-1 was coligated. This leads us to propose that immune cells using germline-encoded receptors to directly recognize foreign proteins can use integrin recognition to differentiate between free pathogens and pathogen-infected cells that will both be present in blood. This distinction would not be required for NK cell receptors, such as NKG2D, which recognize host cell–encoded proteins that can only be found on diseased cells and not pathogens.

Description: Over the past 15 years, numerous studies have suggested that the sinking branches of Earth’s Hadley circulation and the associated subtropical dry zones have shifted poleward over the late twentieth century and early twenty-first century. Early estimates of this tropical widening from satellite observations and reanalyses varied from 0.25° to 3° latitude per decade, while estimates from global climate models show widening at the lower end of the observed range. In 2016, two working groups, the U.S. Climate Variability and Predictability (CLIVAR) working group on the Changing Width of the Tropical Belt and the International Space Science Institute (ISSI) Tropical Width Diagnostics Intercomparison Project, were formed to synthesize current understanding of the magnitude, causes, and impacts of the recent tropical widening evident in observations. These working groups concluded that the large rates of observed tropical widening noted by earlier studies resulted from their use of metrics that poorly capture changes in the Hadley circulation, or from the use of reanalyses that contained spurious trends. Accounting for these issues reduces the range of observed expansion rates to 0.25°–0.5° latitude decade‒1—within the range from model simulations. Models indicate that most of the recent Northern Hemisphere tropical widening is consistent with natural variability, whereas increasing greenhouse gases and decreasing stratospheric ozone likely played an important role in Southern Hemisphere widening. Whatever the cause or rate of expansion, understanding the regional impacts of tropical widening requires additional work, as different forcings can produce different regional patterns of widening.