A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine

[This corrects the article DOI: 10.1186/s13054-016-1208-6.]

Deletion of DOCK2, a regulator of the actin cytoskeleton in lymphocytes, suppresses cardiac allograft rejection

Allograft rejection is induced by graft tissue infiltration of alloreactive T cells that are activated mainly in secondary lymphoid organs of the host. DOCK2 plays a critical role in lymphocyte homing and immunological synapse formation by regulating the actin cytoskeleton, yet its role in the in vivo immune response remains unknown. We show here that DOCK2 deficiency enables long-term survival of cardiac allografts across a complete mismatch of the major histocompatibility complex molecules. In DOCK2-deficient mice, alloreactivity and allocytotoxicity were suppressed significantly even after in vivo priming with alloantigens, which resulted in reduced intragraft expression of effector molecules, such as interferon-γ, granzyme B, and perforin. This is mediated, at least in part, by preventing potentially alloreactive T cells from recruiting into secondary lymphoid organs. In addition, we found that DOCK2 is critical for CD28-mediated Rac activation and is required for the full activation of alloreactive T cells. Although DOCK2-deficient, alloreactive T cells were activated in vitro in the presence of exogenous interleukin-2, these T cells, when transferred adoptively, failed to infiltrate into the allografts that were transplanted into RAG1-deficient mice. Thus, DOCK2 deficiency attenuates allograft rejection by simultaneously suppressing multiple and key processes. We propose that DOCK2 could be a novel molecular target for controlling transplant rejection

HIV-1 Nef Binds the DOCK2–ELMO1 Complex to Activate Rac and Inhibit Lymphocyte Chemotaxis

The infectious cycle of primate lentiviruses is intimately linked to interactions between cells of the immune system. Nef, a potent virulence factor, alters cellular environments to increase lentiviral replication in the host, yet the mechanisms underlying these effects have remained elusive. Since Nef likely functions as an adaptor protein, we exploited a proteomic approach to directly identify molecules that Nef targets to subvert the signaling machinery in T cells. We purified to near homogeneity a major Nef-associated protein complex from T cells and identified by mass spectroscopy its subunits as DOCK2–ELMO1, a key activator of Rac in antigen- and chemokine-initiated signaling pathways, and Rac. We show that Nef activates Rac in T cell lines and in primary T cells following infection with HIV-1 in the absence of antigenic stimuli. Nef activates Rac by binding the DOCK2–ELMO1 complex, and this interaction is linked to the abilities of Nef to inhibit chemotaxis and promote T cell activation. Our data indicate that Nef targets a critical switch that regulates Rac GTPases downstream of chemokine- and antigen-initiated signaling pathways. This interaction enables Nef to influence multiple aspects of T cell function and thus provides an important mechanism by which Nef impacts pathogenesis by primate lentiviruses

A fine structural study of divalent cation-mediated epithelial union with connective tissue in human oral mucosa

Following incubation in an isotonic saline solution containing 20 mM EDTA, human oral mucosa may be separated into its epithelial and connective tissue components. Ultrastructural study of the separated tissues reveals that the plane of separation is through the lamina lucida. Hemidesmosomal structure is altered by the separation process: the peripheral density is absent but a fine, generally filamentous material remains associated with the outer membrane leaflet of the hemidesmosome. Desmosome structure is not altered. An intact lamina densa remains attached to the connective tissue fragment. Oral mucosa incubated in EDTA-saline containing calcium, or its return to a divalent cation-supplemented medium after treatment with EDTA, prevents separation. By maintaining the structural integrity of the hemidesmosome, divalent cations appear to play a principal role in uniting oral mucosal epithelium to the lamina propria.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/49659/1/1001330406_ftp.pd

Calcium binding properties of rat heart plasma membrane and inhibition by structural analogues of dl-propranoloL

The isolation and characterization of a plasma membrane preparation from rat heart is described. Enzymatic, chemical, and electron microscopic analysis revealed a relative lack of contamination with nuclear, mitochondrial, ribosomal, and sarcoplasmic reticulum membrane. One calcium binding site (Kd) = 265 [mu]M, Bmax = 65 nmoles/mg protein) was detected by equilibrium dialysis. Monovalent metal ions exhibited 10-100-fold less inhibition potency than divalent metal ions when analyzed by competitive inhibition of calcium binding. The range of Ki values found for divalent metal ions was similar to the Kd value for calcium. La+3 produced a potent non-competitive inhibition. A large variety of structural analogues of d,l-propranolol, many of which have been shown to lack [beta]-adrenergic blocking activity, were competitive inhibitors of the calcium binding activity, with Ki values ranging from 40-900 [mu]M. Electrophilic, hydrophobic, and diamino substituents greatly increased the inhibitory activity. There was no significant difference between related tertiary and quaternary amines. The experimental antiarrhythmic agent UM 272 had the least ability to inhibit calcium binding to the cardiac plasma membrane preparation (Ki = 795 [mu]M). However, UM 424, another experimental antiarrhythmic agent, had an inhibitory activity similar to dl-propranolol (ki = 115 [mu]M and 108 [mu]M, respectively).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22807/1/0000364.pd

Mrp1 is involved in lipid presentation and iNKT cell activation by Streptococcus pneumoniae

The CD1d pathway present lipid antigens resulting in the activation of iNKT cells but the complete pathway remains to be fully elucidated. Here, Chandra et al. use an siRNA screen and identify Mrp1 as crucial for CD1d lipid presentation and activation of iNKT in the context of Streptococcus pneumoniae infection

BK-UM in patients with recurrent ovarian cancer or peritoneal cancer: a first-in-human phase-I study

BACKGROUND: BK-UM (CRM197) is a mutant form of diphtheria toxin and a specific inhibitor of heparin-binding epidermal growth factor-like growth factor (HB-EGF). We assessed the safety, pharmacokinetics, recommended dose, and efficacy of BK-UM in patients with recurrent ovarian cancer (OC) or peritoneal cancer (PC), and measured HB-EGF levels in serum and abdominal fluid after BK-UM administration. METHODS: Eleven patients with advanced or recurrent OC or PC were enrolled and treated with BK-UM via the intraperitoneal route. The dose was escalated (1.0, 2.0, 3.3, and 5.0 mg/m(2)) using a 3 + 3 design. RESULTS: Eight of 11 patients completed treatment. No dose-limiting toxicity (DLT) was experienced at dose levels 1 (1.0 mg/m(2)) and 2 (2.0 mg/m(2)). Grade 3 transient hypotension as an adverse event (defined as a DLT in the present study) was observed in two of four patients at dose level 3 (3.3 mg/m(2)). Treatment with BK-UM was associated with decreases in HB-EGF levels in serum and abdominal fluid in seven of 11 patients and five of eight patients, respectively. Clinical outcomes included a partial response in one patient, stable disease in five patients, and progressive disease in five patients. CONCLUSIONS: BK-UM was well tolerated at doses of 1.0 and 2.0 mg/m(2), with evidence for clinical efficacy in patients with recurrent OC or PC. A dose of 2.0 mg/m(2) BK-UM is recommended for subsequent clinical trials. TRIAL REGISTRATION: This trial was prospectively performed as an investigator-initiated clinical trial. The trial numbers are UMIN000001002 and UMIN000001001, with registration dates of 1/30/2008 and 2/4/2008, respectively. UMIN000001001 was registered as a trial for the continuous administration of BK-UM after UMIN000001002. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12885-017-3071-5) contains supplementary material, which is available to authorized users