Restricting glycolysis impairs brown adipocyte glucose and oxygen consumption

During thermogenic activation, brown adipocytes take up large amounts of glucose. In addition, cold stimulation leads to an upregulation of glycolytic enzymes. Here we have investigated the importance of glycolysis for brown adipocyte glucose consumption and thermogenesis. Using siRNA-mediated knockdown in mature adipocytes, we explored the effect of glucose transporters and glycolytic enzymes on brown adipocyte functions such as consumption of glucose and oxygen. Basal oxygen consumption in brown adipocytes was equally dependent on glucose and fatty acid oxidation, whereas isoproterenol (ISO)-stimulated respiration was fueled mainly by fatty acids, with a significant contribution from glucose oxidation. Knockdown of glucose transporters in brown adipocytes not only impaired ISO-stimulated glycolytic flux but also oxygen consumption. Diminishing glycolytic flux by knockdown of the first and final enzyme of glycolysis, i.e., hexokinase 2 (HK2) and pyruvate kinase M (PKM), respectively, decreased glucose uptake and ISO-stimulated oxygen consumption. HK2 knockdown had a more severe effect, which, in contrast to PKM knockdown, could not be rescued by supplementation with pyruvate. Hence, brown adipocytes rely on glucose consumption and glycolytic flux to achieve maximum thermogenic output, with glycolysis likely supporting thermogenesis not only by pyruvate formation but also by supplying intermediates for efferent metabolic pathways.

Follow-up of the Post-Liver Transplantation Patient: A Primer for the Practicing Gastroenterologist

The focus in liver transplantation in the next 10 years will likely change from preventing viral disease recurrence to minimizing the toll of rejection and fatty liver disease, minimizing the complications from immunosuppression with withdrawal strategies, and more optimal management of long-term risks, such as malignancy, cardiovascular disease, and renal failure. In addition, now that short-term results (<1 year) have improved significantly, there will be a shift toward improving long-term patient and graft survival, as well as a focus on primary care preventive strategies.

Economic Evaluations of Strategies to Prevent Hospital-Acquired Pressure Injuries

GENERAL PURPOSE

To provide information from a review of literature about economic evaluations of preventive strategies for pressure injuries (PIs).

TARGET AUDIENCE

This continuing education activity is intended for physicians, physician assistants, nurse practitioners, and nurses with an interest in skin and wound care.

LEARNING OBJECTIVES/OUTCOMES

After participating in this educational activity, the participant should be better able to:1. Identify the purpose and methods used for this study.2. Compare costs and effectiveness related to preventative strategies for PIs.

ABSTRACT

BACKGROUND: Pressure injuries (PIs) are a common and resource-intensive challenge for acute care hospitals worldwide. While a number of preventive strategies have the potential to reduce the cost of hospital-acquired PIs, it is unclear what approach is the most effective.

OBJECTIVE

The authors performed a narrative review of the literature on economic evaluations of preventive strategies to survey current findings and identify important factors in economic assessments.

DATA SOURCES

Ovid, MEDLINE, NHS Economic Evaluation Databases, and the Cochrane Database of Systematic ReviewsSELECTION CRITERIA: Potentially relevant original research articles and systematic reviews were considered.

DATA EXTRACTION

Selection criteria included articles that were written in English, provided data on cost or economic evaluations of preventive strategies of PIs in acute care, and published between January 2004 and September 2015. Data were abstracted from the articles using a standardized approach to evaluate how the items on the Consolidated Health Economic Evaluation Reporting Standards checklist were addressed.

DATA SYNTHESIS

The searches identified 192 references. Thirty-three original articles were chosen for full-text reviews. Nineteen of these articles provided clear descriptions of interventions, study methods, and outcomes considered.

CONCLUSIONS

Limitations in the available literature prevent firm conclusions from being reached about the relative economic merits of the various approaches to the prevention of PIs. The authors' review revealed a need for additional high-quality studies that adhere to commonly used standards of both currently utilized and emerging ways to prevent hospital-acquired PIs.

Detecting intratumoral heterogeneity of EGFR activity by liposome-based in vivo transfection of a fluorescent biosensor

Despite decades of research in the epidermal growth factor receptor (EGFR) signalling field, and many targeted anti-cancer drugs that have been tested clinically, the success rate for these agents in the clinic is low, particularly in terms of the improvement of overall survival. Intratumoral heterogeneity is proposed as a major mechanism underlying treatment failure of these molecule-targeted agents. Here we highlight the application of fluorescence lifetime microscopy (FLIM)-based biosensing to demonstrate intratumoral heterogeneity of EGFR activity. For sensing EGFR activity in cells, we used a genetically encoded CrkII-based biosensor which undergoes conformational changes upon tyrosine-221 phosphorylation by EGFR. We transfected this biosensor into EGFR-positive tumour cells using targeted lipopolyplexes bearing EGFR-binding peptides at their surfaces. In a murine model of basal-like breast cancer, we demonstrated a significant degree of intratumoral heterogeneity in EGFR activity, as well as the pharmacodynamic effect of a radionuclide-labeled EGFR inhibitor in situ. Furthermore, a significant correlation between high EGFR activity in tumour cells and macrophage-tumour cell proximity was found to in part account for the intratumoral heterogeneity in EGFR activity observed. The same effect of macrophage infiltrate on EGFR activation was also seen in a colorectal cancer xenograft. In contrast, a non-small cell lung cancer xenograft expressing a constitutively active EGFR conformational mutant exhibited macrophage proximity-independent EGFR activity. Our study validates the use of this methodology to monitor therapeutic response in terms of EGFR activity. In addition, we found iNOS gene induction in macrophages that are cultured in tumour cell-conditioned media as well as an iNOS activity-dependent increase in EGFR activity in tumour cells. These findings point towards an immune microenvironment-mediated regulation that gives rise to the observed intratumoral heterogeneity of EGFR signalling activity in tumour cells in vivo.

A Mixed-methods Study to Assess Interrater Reliability and Nurse Perception of the Braden Scale in a Tertiary Acute Care Setting

Research regarding the reliability of the Braden Scale and nurses' perspectives on the instrument for predicting pressure ulcer (PU) risk in acute care settings is limited. A mixed-methods study was conducted in a tertiary acute care facility to examine interrater reliability (IRR) of the Braden Scale and its subscales, and a qualitative survey using semi-structured interviews was conducted among nurses caring for patients in acute care units to gain nurse perspective regarding scale usability. Data were extracted from a previous retrospective, randomized, controlled trial involving adult patients with compromised mobility receiving care in a tertiary acute care hospital in Canada. One-way, intraclass correlation coefficients (ICCs) were calculated on item and total scores, and kappa statistics were used to determine reliability of categorizing patients on their risk. Interview results were categorized by common themes. Reliability was assessed on 64 patients, where nurses and research staff independently assessed enrolled participants at baseline and after 72 hours using the Braden Scale as it appeared on an electronic medical record. IRR for the total score was high (ICC = 0.807). The friction and shear item had the lowest reliability (ICC = 0.266). Reliability of categorizing patients' level of risk had moderate agreement (κ = 0.408). Three (3) major and 12 subthemes emerged from the 14 nurse interviews; nurses were aware of the scale's purpose but were uncertain of its effectiveness, some items were difficult to rate, and questions were raised as to whether using the scale enhanced patient care. Aspects identified by nurses to enhance usability included: 1) changes to the electronic version (incorporating the scale into daily assessment documents with readily available item descriptions), 2) additional training, and 3) easily available resource material to improve reliability and usability of scale. These findings need to be considered when using the Braden Scale in clinical practice. Further study of the value of the total Braden Scale and its subscales is warranted.

Osteonecrosis of the jaw (ONJ): diagnosis and management in 2015

Osteonecrosis of the jaw (ONJ) has been associated with the use of aminobisphosphonates and denosumab. The vast majority (>90%) of cases occur in the oncology patient population receiving high doses of intravenous bisphosphonates or subcutaneous denosumab. The incidence of ONJ in the osteoporosis patient population is very low and is estimated at 1-90 per 100,000 patient-years of exposure. In the oncology patient population the incidence appears to be related to dose and duration of exposure, and prevalence has been estimated to be as high as 18.6%. A number of risk factors in addition to antiresorptive therapy have been identified. These include the presence of periodontal disease, oral surgical procedures with extractions or implants, radiation therapy, chemotherapy, diabetes, glucocorticoid use, and smoking. Antiangiogenic agents appear to contribute to the risk of ONJ, however, data at this time are limited and further evidence is required prior to confirming a causal relationship. ONJ may be prevented with optimization of oral hygiene, the use of oral antimicrobial mouth rinses, as well as systemic antibiotic therapy. Individuals not responding to conservative management or in the advanced stages of ONJ may be considered for surgery, as data over the past several years have demonstrated surgical success in this patient population. Case reports have indicated that teriparatide may enhance healing. A number of experimental therapies are being evaluated and include the use of bone marrow stem cell intralesional transplantation, local application of platelet-derived growth factor, hyperbaric oxygen, tissue grafting, and low-level laser therapy. This paper summarizes the current research as well as the international consensus on the diagnosis and management of ONJ.