Proteomic analysis identifies the E3 ubiquitin ligase Pdzrn3 as a regulatory target of Wnt5a-Ror signaling.

Wnt5a-Ror signaling is a conserved pathway that regulates morphogenetic processes during vertebrate development [R. T. Moon et al, Development 119, 97-111 (1993); I. Oishi et al, Genes Cells 8, 645-654 (2003)], but its downstream signaling events remain poorly understood. Through a large-scale proteomic screen in mouse embryonic fibroblasts, we identified the E3 ubiquitin ligase Pdzrn3 as a regulatory target of the Wnt5a-Ror pathway. Upon pathway activation, Pdzrn3 is degraded in a ß-catenin-independent, ubiquitin-proteasome system-dependent manner. We developed a flow cytometry-based reporter to monitor Pdzrn3 abundance and delineated a signaling cascade involving Frizzled, Dishevelled, Casein kinase 1, and Glycogen synthase kinase 3 that regulates Pdzrn3 stability. Epistatically, Pdzrn3 is regulated independently of Kif26b, another Wnt5a-Ror effector. Wnt5a-dependent degradation of Pdzrn3 requires phosphorylation of three conserved amino acids within its C-terminal LNX3H domain [M. Flynn, O. Saha, P. Young, BMC Evol. Biol. 11, 235 (2011)], which acts as a bona fide Wnt5a-responsive element. Importantly, this phospho-dependent degradation is essential for Wnt5a-Ror modulation of cell migration. Collectively, this work establishes a Wnt5a-Ror cell morphogenetic cascade involving Pdzrn3 phosphorylation and degradation.

Adipocytes Provide Fatty Acids to Acute Lymphoblastic Leukemia Cells.

BACKGROUND: There is increasing evidence that adipocytes play an active role in the cancer microenvironment. We have previously reported that adipocytes interact with acute lymphoblastic leukemia (ALL) cells, contributing to chemotherapy resistance and treatment failure. In the present study, we investigated whether part of this resistance is due to adipocyte provision of lipids to ALL cells. METHODS: We cultured 3T3-L1 adipocytes, and tested whether ALL cells or ALL-released cytokines induced FFA release. We investigated whether ALL cells took up these FFA, and using fluorescent tagged BODIPY-FFA and lipidomics, evaluated which lipid moieties were being transferred from adipocytes to ALL. We evaluated the effects of adipocyte-derived lipids on ALL cell metabolism using a Seahorse XF analyzer and expression of enzymes important for lipid metabolism, and tested whether these lipids could protect ALL cells from chemotherapy. Finally, we evaluated a panel of lipid synthesis and metabolism inhibitors to determine which were affected by the presence of adipocytes. RESULTS: Adipocytes release free fatty acids (FFA) when in the presence of ALL cells. These FFA are taken up by the ALL cells and incorporated into triglycerides and phospholipids. Some of these lipids are stored in lipid droplets, which can be utilized in states of fuel deprivation. Adipocytes preferentially release monounsaturated FFA, and this can be attenuated by inhibiting the desaturating enzyme steroyl-CoA decarboxylase-1 (SCD1). Adipocyte-derived FFA can relieve ALL cell endogenous lipogenesis and reverse the cytotoxicity of pharmacological acetyl-CoA carboxylase (ACC) inhibition. Further, adipocytes alter ALL cell metabolism, shifting them from glucose to FFA oxidation. Interestingly, the unsaturated fatty acid, oleic acid, protects ALL cells from modest concentrations of chemotherapy, such as those that might be present in the ALL microenvironment. In addition, targeting lipid synthesis and metabolism can potentially reverse adipocyte protection of ALL cells. CONCLUSION: These findings uncover a previously unidentified interaction between ALL cells and adipocytes, leading to transfer of FFA for use as a metabolic fuel and macromolecule building block. This interaction may contribute to ALL resistance to chemotherapy, and could potentially be targeted to improve ALL treatment outcome.

The unappreciated challenges of between-unit handoffs: negotiating and coordinating across boundaries.

Although interest in studying and improving handoffs has grown considerably in recent years, a general tendency to treat handoff as a single type of activity has resulted in overlooking important variation and in understudying one consequential type: between-unit handoffs. Using the admission handoff between emergency departments and inpatient services as an example, this conceptual article identifies 2 distinguishing structural features of between-unit transitions and demonstrate how these features create negotiation and coordination challenges that are further complicated by several contextual factors. Between-unit handoffs are distinguished from within-unit handoffs because the former are triggered by patient conditions as opposed to shift schedules and entail working across organizational boundaries rather than within them. Consequently, between-unit handoffs are challenged by several contextual factors, including interprofessional differences, unequal distributions of power among units, frequent lack of established relationships among the involved parties, infrequent face-to-face communication, a lack of awareness of the other unit's state, and the fact that responsibility and control of patients are transferred separately. Implications for improvement are discussed.

A handoff is not a telegram: an understanding of the patient is co-constructed.

Hospital handoffs are believed to be a key locus of communication breakdown that can endanger patient safety and undermine quality of care. Substantial new efforts to better understand handoffs and to improve handoff practices are under way. Many such efforts appear to be seriously hampered, however, by an underlying presumption that the essential function of a handoff is one-way information transmission. Here, we examine social science literature that supports a richer framing of handoff conversations, one that characterizes them as co-constructions of an understanding of the patient.

Handover patterns: an observational study of critical care physicians.

BACKGROUND: Handover (or 'handoff') is the exchange of information between health professionals that accompanies the transfer of patient care. This process can result in adverse events. Handover 'best practices', with emphasis on standardization, have been widely promoted. However, these recommendations are based mostly on expert opinion and research on medical trainees. By examining handover communication of experienced physicians, we aim to inform future research, education and quality improvement. Thus, our objective is to describe handover communication patterns used by attending critical care physicians in an academic centre and to compare them with currently popular, standardized schemes for handover communication. METHODS: Prospective, observational study using video recording in an academic intensive care unit in Ontario, Canada. Forty individual patient handovers were randomly selected out of 10 end-of-week handover sessions of attending physicians. Two coders independently reviewed handover transcripts documenting elements of three communication schemes: SBAR (Situation, Background, Assessment, Recommendations); SOAP (Subjective, Objective, Assessment, Plan); and a standard medical admission note. Frequency and extent of questions asked by incoming physicians were measured as well. Analysis consisted of descriptive statistics. RESULTS: Mean (± standard deviation) duration of patient-specific handovers was 2 min 58 sec (± 57 sec). The majority of handovers' content consisted of recent and current patient status. The remainder included physicians' interpretations and advice. Questions posed by the incoming physicians accounted for 5.8% (± 3.9%) of the handovers' content. Elements of all three standardized communication schemes appeared repeatedly throughout the handover dialogs with no consistent pattern. For example, blocks of SOAP's Assessment appeared 5.2 (± 3.0) times in patient handovers; they followed Objective blocks in only 45.9% of the opportunities and preceded Plan in just 21.8%. Certain communication elements were occasionally absent. For example, SBAR's Recommendation and admission note information about the patient's Past Medical History were absent from 22 (55.0%) and 20 (50.0%), respectively, of patient handovers. CONCLUSIONS: Clinical handover practice of faculty-level critical care physicians did not conform to any of the three predefined structuring schemes. Further research is needed to examine whether alternative approaches to handover communication can be identified and to identify features of high-quality handover communication.

Hospital handoffs as multifunctional situated routines: implications for researchers and administrators.

Patient handoffs involve the exchange of information between health professionals accompanying a transfer of responsibility for, or control of, a patient. Concerns over the safety risks of poor handoffs have resulted in regulatory pressure to standardize practice and considerable growth in research. But handoffs involve more than information transfer, and their consequences for health care organizations extend beyond the safety of patients. Using an organization theory lens, we review the literature on handoffs and propose a framework that characterizes handoffs as multifunctional, situated organizational routines. We also identify implications for researchers and hospital policymakers. Standardization and improvement efforts run the risk of causing unintended problems if they overlook the complexity of handoff and the larger organizational functions it serves. Deepening our understanding of the multifunctional, situated nature of handoff can lead to improvement efforts that not only safeguard individual patients, but also enhance the capabilities of the larger health care organization.

The published literature on handoffs in hospitals: deficiencies identified in an extensive review.

BACKGROUND: In hospitals, handoffs are episodes in which control of, or responsibility for, a patient passes from one health professional to another, and in which important information about the patient is also exchanged. In view of the growing interest in improving handoff processes, and the need for guidance in arriving at standardised handoff procedures in response to regulatory requirements, an extensive review of the research on handoffs was conducted. METHODS: The authors have collected all research treatments of hospital handoffs involving medical personnel published in English through July 2008. RESULTS: A review of this literature yields four significant CONCLUSIONS: (1) the definition of the handoff concept in the literature is poorly delimited; (2) the meaning of 'to standardise' has not been developed with adequate clarity; (3) the literature shows that handoffs perform important functions beyond patient safety, but the trade-offs of these functions against safety considerations are not analysed; (4) studies so far do not fully establish that attempts at handoff standardisation have produced marked gains in measured patient outcomes. CONCLUSION: The existing literature on patient handoffs does not yet adequately support either definitive research conclusions on best handoff practices or the standardisation of handoffs that has been mandated by some regulators.

Social closeness increases salivary progesterone in humans.

We examined whether interpersonal closeness increases salivary progesterone. One hundred and sixty female college students (80 dyads) were randomly assigned to participate in either a closeness task with a partner versus a neutral task with a partner. Those exposed to the closeness induction had higher levels of progesterone relative to those exposed to the neutral task. Across conditions, progesterone increase one week later predicted the willingness to sacrifice for the partner. These results are discussed in terms of the links between social contact, stress, and health.

Rapid size dependent deletion of foreign gene sequences inserted into attenuated HIV-1 upon infection in vivo: implications for vaccine development.

Live attenuated HIV vaccines offer a means to introduce exogenous sequences into the viral genome to target the virus elimination in vivo. Foreign genes inserted into the nef region of HIV-1 NL4-3 were found to be rapidly deleted following virus infection and/or replication, in a size dependent manner, in the human fetal Thymus/Liver implants of severe combined immunodeficient mouse (SCID-hu) model. When the murine heat stable antigen (HSA) of 283 bp was substituted into HIV-1 nef region, the viral loads in vivo were comparable to the negative control nef attenuated HIV-1, and the reporter HSA gene was not deleted upon infection. However, the murine Thy1.2 gene (505 bp) substituted into the nef attenuated HIV-1, upon infection and replication, deleted 441 bp in vitro and 437 bp in vivo, of the inserted Thy1.2 gene. When the enhanced green fluorescence protein (eGFP) gene (720 bp) was substituted for nef, virus replication was aborted in vivo in the Thy/Liv implants, as seen by the background levels of viral loads, comparable to mock infected implants, and the eGFP gene was deleted. When the herpes simplex virus thymidine kinase gene, HSV-TK (1.15 kbp), or HSA gene, was substituted into the viral vpr gene, TK but not HSA gene was deleted, upon infection in vitro. Moreover, NL-TKI reporter virus with both intact nef and vpr genes shows deletion of TK gene both in vitro and in vivo. Excision of foreign genes occurred within the exogenous segments but not in the viral own regions. These results suggest that larger "suicide" genes introduced via HIV-1 can be deleted upon infection. However, smaller size nucleotide sequences or genes (approximately 300 bp) inserted in place of viral nef or vpr gene may be used to target the virus or its components, for attack and elimination in vivo, and thus have implications for the development of live attenuated HIV vaccines.