Vertical flux and microplankton assemblages in the Gulf of Liions during spring 1990

A vertical flux pulse related to spring phytoplankton development was recorded ·by moored sediment traps at 42°N 06°E in the Gulf of Lions. May 1990 trap samples from 200m to 2000m depth were comprised of freshly produced organic matter and selected microplankton species from the overlaying water column. This vertical flux event was transmitted to the deep sea floor with a high particle sinking velocity of >140 m day-1. Maximal vertical fluxes of 35 mg C m-2 day-1 and 1.2 mg chl.a m-2 day-1 recorded during this event are low compared to the exports from collapsing spring blooms at higher latitudes but demonstrate that particle production and degradation within the spring pelagic system were not in balance

The vertical flux of rare earth elements in the northwestern Mediterranean

Rare earth element (REE) composition of sinking particles was examined in time-series sediment trap samples collected from four depths (200, 500, 1000, 2000 m) in the Gulf of Lions. Vertical flux profiles showed the occurrence of a sedimentation pulse which resulted in the rapid sinking of phytoplankton aggregates to 2000 m depth. These particles were characterized by REE patterns similar to those in the upper 200 m indicating that little, if any, additional REE scavenging occurred during the sedimentation event. In contrast, after the sedimentation pulse, particles from deep waters showed an enrichment of light-REE (LREE) relative to heavy-REE (HREE) and a positive Ce anomaly. Comparing REE patterns in particles from the upper water column (200 m) with those from depth (1000, 2000 m) during and following the sedimentation pulse indicates that time is a key factor in determining REE scavenging by sinking particles. This is particularly evident for the preferential scavenging of Ce (IV) which is most pronounced in the finer, slowly sinking, and presumably older particles. These findings are consistent with REE patterns in sea water from the northwestern Mediterranean which show a strong negative Ce anomaly and gradual enrichment of REE with increasing atomic number. The enrichment of LREE relative to HREE in particles from deep waters results either preferential scavenging of LREE on particles, analogous to the enrichment of Ce, or selective dissolution of HREE in association with particle remineralization processes, or both; this aspect of REE behaviour merits further study

Benthic response to sedimentation events during autumn to spring at a shallow-water station in the Western Kiel Bight

The response of the benthos to the break up of anoxia in the Kiel Bight (Western Baltic Sea), and to three succeeding events of “external” food supply, consisting of a settled autumn plankton bloom, resuspended matter and macrophyte input during winter, and of a sedimented spring phytoplankton bloom, is described on a community level. The first input of oxygen broke up anoxic conditions and made stored food resources available to decomposition. This “internal” food supply, mainly consisting of protein (folin positive matter), was followed by a drastic increase in heat production and ATP-biomass and caused a period of low redox potential, which lasted for several weeks. During this phase, a plankton bloom (dinoflagellates and diatoms) settled to the sea floor. Although there was an immediate response of benthic activity, this food input was not completely consumed by the strongly disturbed benthic community. During winter resuspended matter and the input of macrophyte debris caused another maximum in benthic activity and biomass despite the low temperature. The response to sedimentation of cells from a diatom bloom during mid March was also without any time lag and was consumed within 5–6 wk. A comparison of the amount of particles collected in a sediment trap with the increase of organic matter in the sediment demonstrated that the sediment collected four times (autumn) and seven to eight times (spring) more than measured by the sediment trap. Strong indications of food limitation of benthic activity were found. During autumn and winter these indications were caused more by physical than by biological processes. The three events of “external” food supply caused a temporary shift in the type of metabolism towards fermentation processes and reduced the redox potential. In spring the development of the benthic community was still being strongly influenced by the events of the preceding summer and autumn

Pelagic processes and vertical flux of particles: an overview of a long-term comparative study in the Norwegian Sea and Greenland Sea

Pelagic processes and their relation to vertical flux have been studied in the Norwegian and Greenland Seas since 1986. Results of long-term sediment trap deployments and adjoining process studies are presented, and the underlying methodological and conceptional background is discussed. Recent extension of these investigations at the Barents Sea continental slope are also presented. With similar conditions of input irradiation and nutrient conditions, the Norwegian and Greenland Seas exhibit comparable mean annual rates of new and total production. Major differences can be found between these regions, however, in the hydrographic conditions constraining primary production and in the composition and seasonal development of the plankton. This is reflected in differences in the temporal patterns of vertical particle flux in relation to new production in the euphotic zone, the composition of particles exported and in different processes leading to their modification in the mid-water layers. In the Norwegian Sea heavy grazing pressure during early spring retards the accumulation of phytoplankton stocks and thus a mass sedimentation of diatoms that is often associated with spring blooms. This, in conjunction with the further seasonal development of zooplankton populations, serves to delay the annual peak in sedimentation to summer or autumn. Carbonate sedimentation in the Norwegian Sea, however, is significantly higher than in the Greenland Sea, where physical factors exert a greater control on phytoplankton development and the sedimentation of opal is of greater importance. In addition to these comparative long-term studies a case study has been carried out at the continental slope of the Barents Sea, where an emphasis was laid on the influence of resuspension and across-slope lateral transport with an analysis of suspended and sedimented material

Recent developments in immunotherapy of acute myeloid leukemia

The advent of new immunotherapeutic agents in clinical practice has revolutionized cancer treatment in the past decade, both in oncology and hematology. The transfer of the immunotherapeutic concepts to the treatment of acute myeloid leukemia (AML) is hampered by various characteristics of the disease, including non-leukemia-restricted target antigen expression profile, low endogenous immune responses, and intrinsic resistance mechanisms of the leukemic blasts against immune responses. However, considerable progress has been made in this field in the past few years. Within this manuscript, we review the recent developments and the current status of the five currently most prominent immunotherapeutic concepts: (1) antibody-drug conjugates, (2) T cell-recruiting antibody constructs, (3) chimeric antigen receptor (CAR) T cells, (4) checkpoint inhibitors, and (5) dendritic cell vaccination. We focus on the clinical data that has been published so far, both for newly diagnosed and refractory/relapsed AML, but omitting immunotherapeutic concepts in conjunction with hematopoietic stem cell transplantation. Besides, we have included important clinical trials that are currently running or have recently been completed but are still lacking full publication of their results. While each of the concepts has its particular merits and inherent problems, the field of immunotherapy of AML seems to have taken some significant steps forward. Results of currently running trials will reveal the direction of further development including approaches combining two or more of these concepts

Ex vivo culture of chimeric antigen receptor T cells generates functional CD8 T cells with effector and central memory-like phenotype

The anti-tumor efficacy of adoptively transferred T cells requires their in vivo persistence and memory polarization. It is unknown if human chimeric antigen receptor (CAR)-expressing T cells can also undergo memory polarization. We examined the functional status of CAR CD8 T cells, re-directed to Lewis Y antigen (LeY-T), throughout a period of ex vivo expansion. Immediately before culture CD8 T cells comprised a mixture of phenotypes including naive (CD45RA /CCR7 /CD27 /CD28 /perforin), central memory (CM, CD45RA /CCR7 lo /CD27 /CD28 /perforin lo), effector memory (EM, CD45RA /CCR7 /CD27 /CD28 /perforin mod) and effector (Eff, CD45RA /CCR7 /CD27 /CD28 /perforin hi) cells. After transduction and expansion culture of peripheral blood mononuclear cells from normal donors or multiple myeloma patients, CD8 LeY-T cells polarized to EM- and CM-like phenotype. CD8 LeY-T cells differed from starting CD8 CM and EM T cells in that CD27, but not CD28, was downregulated. In addition, CD8 LeY-T cells expressed high levels of perforin, similar to starting CD8 Eff. CD8 LeY-T cells also showed hallmarks of both memory and Eff function, underwent homeostatic proliferation in response to interleukin (IL)-15, and showed interferon (IFN)-γ production and cytotoxicity in response to Le-Y antigen on OVCAR-3 (human ovarian adenocarcinoma) cells. This study confirms CD8 LeY-T cells have a CM- and EM-like phenotype and heterogeneous function consistent with potential to persist in vivo after adoptive transfer