Effects of the Level and Duration of Mobilization Therapy in the Surgical ICU on the Loss of the Ability to Live Independently: An International Prospective Cohort Study.

OBJECTIVES: It is unclear whether early mobilization in the surgical ICU helps improve patients' functional recovery to a level that enables independent living. We assessed dose of mobilization (level + duration). We tested the research hypotheses that dose of mobilization predicts adverse discharge and that both duration of mobilization and maximum mobilization level predict adverse discharge. DESIGN: International, prospective cohort study. SETTING: Study conducted in five surgical ICUs at four different institutions. PATIENTS: One hundred fifty patients who were functionally independent before admission (Barthel Index ≥ 70) and who were expected to stay in the ICU for greater than or equal to 72 hours. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Mobilization was quantified daily, and treatments from all healthcare providers were included. We developed and used the Mobilization Quantification Score that quantifies both level and duration of mobilization. We assessed the association between the dose of mobilization (level + duration; exposure) and adverse discharge disposition (loss of the ability to live independently; primary outcome). There was wide variability in the dose of mobilization across centers and patients, which could not be explained by patients' comorbidity or disease severity. Dose of mobilization was associated with reduced risk of adverse discharge (adjusted odds ratio, 0.21; 95%CI, 0.09-0.50; p < 0.001). Both level and duration explained variance of adverse discharge (adjusted odds ratio, 0.28; 95% CI, 0.12-0.65; p = 0.003; adjusted odds ratio, 0.14; 95% CI, 0.06-0.36; p < 0.001, respectively). Duration compared with the level of mobilization tended to explain more variance in adverse discharge (area under the curve duration 0.73; 95% CI, 0.64-0.82; area under the curve mobilization level 0.68; 95% CI, 0.58-0.77; p = 0.10). CONCLUSIONS: We observed wide variability in dose of mobilization treatment applied, which could not be explained by patients' comorbidity or disease severity. High dose of mobilization is an independent predictor of patients' ability to live independently after discharge. Duration of mobilization sessions should be taken into account in future quality improvement and research projects.

Protocolized Based Management of Cerebrospinal Fluid Drains in Thoracic Endovascular Aortic Aneurysm Repair Procedures.

BACKGROUND: Spinal cord ischemia (SCI) resulting in paraplegia is a devastating complication associated with thoracic endovascular aortic aneurysm repair (TEVAR) whose incidence has significantly declined over time. In this review, we present our experience with a multidisciplinary clinical protocol for cerebrospinal fluid (CSF) drain management in patients undergoing TEVAR. Furthermore, we aimed to characterize complications of CSF drain placement in a large, single center experience of patients who underwent TEVAR. METHODS: This retrospective review is of patients undergoing TEVAR with and without CSF drain placement between January 2014 and December 2019 at a single institution. Patient demographics, hospital course, and drain-related complications were analyzed to assess the incidence of CSF drain-related complications. RESULTS: A total of 235 patients were included in this study, of which 85 received CSF drains. Eighty patients (94.1%) were placed by anesthesiologists, while 5 (5.9%) were placed under fluoroscopic guidance by interventional neurosurgery. The most common level of placement was L3-L4 in 38 (44.7%) cases followed by L4-L5 in 36 (42.4%) cases. The mean duration of CSF drain was 1.9 ± 1.4 days. Complications due to CSF drainage occurred in 5 (5.9%) patients and included partial retainment of catheter, subdural edema, epidural hematoma, headache, and bleeding near the drain site. The overall 30-day mortality rate was 5.5% and did not differ between those who received a CSF drain and those who did not (P = 0.856). The overall incidence of SCI resulting in paraplegia was 1.7% in the studied patients. CONCLUSIONS: A protocol-based CSF drainage program for spinal cord protection involves a multifaceted approach in identification and selection of patients meeting criteria for prophylactic drain placement, direct closed loop communication, and perioperative management by an experienced team. Despite the inherent advantages of CSF drain placement, it is not without complications, thus risk and benefit need to be weighed in context of the procedure and the patient with close communication and team approach.

Regulation of Hypoxic-Adenosinergic Signaling by Estrogen: Implications for Microvascular Injury.

Loss of estrogen, as occurs with normal aging, leads to increased inflammation, pathologic angiogenesis, impaired mitochondrial function, and microvascular disease. While the influence of estrogens on purinergic pathways is largely unknown, extracellular adenosine, generated at high levels by CD39 and CD73, is known to be anti-inflammatory in the vasculature. To further define the cellular mechanisms necessary for vascular protection, we investigated how estrogen modulates hypoxic-adenosinergic vascular signaling responses and angiogenesis. Expression of estrogen receptors, purinergic mediators inclusive of adenosine, adenosine deaminase (ADA), and ATP were measured in human endothelial cells. Standard tube formation and wound healing assays were performed to assess angiogenesis in vitro. The impacts on purinergic responses in vivo were modeled using cardiac tissue from ovariectomized mice. CD39 and estrogen receptor alpha (ERα) levels were markedly increased in presence of estradiol (E2). Suppression of ERα resulted in decreased CD39 expression. Expression of ENT1 was decreased in an ER-dependent manner. Extracellular ATP and ADA activity levels decreased following E2 exposure while levels of adenosine increased. Phosphorylation of ERK1/2 increased following E2 treatment and was attenuated by blocking adenosine receptor (AR) and ER activity. Estradiol boosted angiogenesis, while inhibition of estrogen decreased tube formation in vitro. Expression of CD39 and phospho-ERK1/2 decreased in cardiac tissues from ovariectomized mice, whereas ENT1 expression increased with expected decreases in blood adenosine levels. Estradiol-induced upregulation of CD39 substantially increases adenosine availability, while augmenting vascular protective signaling responses. Control of CD39 by ERα follows on transcriptional regulation. These data suggest novel therapeutic avenues to explore in the amelioration of post-menopausal cardiovascular disease, by modulation of adenosinergic mechanisms.

Hypoxia-mediated biological control.

When oxygen demand is greater than oxygen supply, cells need to rapidly adjust their metabolism in order for the tissue to survive. Oxygen sensing by an organism influences a host of processes including growth, development, metabolism, pH homeostasis, and angiogenesis. Hypoxia also contributes to a wide number of human diseases including vascular disease, inflammatory conditions and cancer. Recently, major advances have been made in understanding the response of cells and tissues to hypoxia with the goal of providing mechanistic insight and novel therapeutic targets. In this article we review both the normal biological effects of hypoxia as well as the alterations that occur in specific disease conditions with an emphasis on the cell signaling and gene transcription mechanisms that underlie the changes associated with chronic hypoxia. Comparisons of studies in the fields of cardiac ischemia and tumor angiogenesis reveal the complexities within the microenvironment that control responses to hypoxia. It is clear that more interaction between researchers in these fields will improve the development of therapies that either promote or prevent hypoxic responses.

Negative regulation of HIF-1α by an FBW7-mediated degradation pathway during hypoxia.

Hypoxia inducible factor-1α (HIF-1α) stimulates expression of genes associated with angiogenesis and is associated with poor outcomes in ovarian and other cancers. In normoxia, HIF-1α is ubiquitinated and degraded through the E3 ubiquitin ligase, von Hippel-Lindau; however, little is known about the regulation of HIF-1α in hypoxic conditions. FBW7 is an E3 ubiquitin ligase that recognizes proteins phosphorylated by glycogen synthase kinase 3ß (GSK3ß) and targets them for destruction. This study used an ovarian cancer cell model to test the hypothesis that HIF-1α phosphorylation by GSK3ß in hypoxia leads to interaction with FBW7 and ubiquitin-dependent degradation. Expression of constitutively active GSK3ß reduced HIF-1α protein and transcriptional activity and increased ubiquitination of HIF-1α in hypoxia, whereas pharmacologic inhibition of GSK3 or expression of siGSK3ß promoted HIF-1α stabilization and activity. A mechanism through FBW7 was supported by the observed decrease in HIF-1α stabilization when FBW7 was overexpressed and both the elevation of HIF-1α levels and decrease in ubiquitinated HIF-1α when FBW7 was suppressed. Furthermore, HIF-1α associated with FBW7γ by co-immunoprecipitation, and the interaction was weakened by inhibition of GSK3 or mutation of GSK3ß phosphorylation sites. The relevance of this pathway to angiogenic signaling was supported by the finding that endothelial cell tube maturation was increased by conditioned media from hypoxic SK-OV-3 cell lines expressing suppressed GSK3ß or FBW7. These data introduce a new mechanism for regulation of HIF-1α during hypoxia that utilizes phosphorylation to target HIF-1α for ubiquitin-dependent degradation through FBW7 and may identify new targets in the regulation of angiogenesis.

Cardiopulmonary Bypass Suppresses Forkhead Box O3 and Downstream Autophagy in the Diabetic Human Heart.

BACKGROUND: Autophagy is an integral component of cellular homeostasis and metabolism. The exact mechanism of impaired autophagy in diabetes mellitus is unknown. Forkhead Box O3 (FOXO3α) is a key regulator of oxidative stress-related responses. We hypothesize FOXO3α is a direct upstream regulator of the autophagy pathway, and its upregulation is compromised in diabetic patients during stress of cardiopulmonary bypass (CPB). METHODS: The study enrolled 32 diabetic and 33 nondiabetic patients undergoing a cardiac surgical procedure on CPB. Right atrial tissue and serum samples were collected before and after CPB per protocol. A set of key components were quantitatively assessed and compared by microarray, immunoblotting, and immunohistochemistry studies. Data were analyzed using paired or unpaired student test. A P of <.05 or less was considered significant. RESULTS: Serum microarray showed FOXO3α was upregulated in the diabetic vs nondiabetic group after CPB (P = .033), autophagy-related 4B gene and Beclin 1 gene were greatly upregulated in the nondiabetic group (P = .028 and P = .002, respectively). On immunoblotting, there was upregulation of FOXO3α in the nondiabetic patients after CPB (P = .003). There were increased levels of Beclin-1, Bcl-2, and light chain 3B after CPB in the nondiabetic group only (P = .016, P = .005, P = .002, respectively). Sirtuin 1, Unc-51-like autophagy activating kinase 1 (ULK1), peroxisome proliferator-activated receptor gamma coactivator 1α (PGC1α), and mammalian target of rapamycin (mTOR) were not significantly changed in the nondiabetic group after CPB. CONCLUSIONS: Compared with nondiabetic patients, there was no significant upregulation of FOXO3α in diabetic patients, which could possibly explain the lack of upregulation of the autophagy process after CPB. FOXO3α could potentially serve as a therapeutic target to improve cellular homeostasis.

Multiple anesthetics for a patient with stiff-person syndrome.

Stiff-person syndrome is a progressive disease of muscle rigidity and spasticity due to a deficiency in the production of γ-aminobutyric acid. Because of the rarity of the condition, little is known about effects of anesthesia on patients with stiff-person syndrome. This report describes the clinical course for a single patient with stiff-person syndrome who received general anesthesia on 3 separate occasions. Her anesthetics included use of both neuromuscular blockade and volatile agents. Unlike several previous reports regarding anesthesia and stiff-person syndrome, the postoperative period for this patient did not require prolonged intubation or result in any residual weakness.

Dysregulation of ezrin phosphorylation prevents metastasis and alters cellular metabolism in osteosarcoma.

Ezrin links the plasma membrane to the actin cytoskeleton where it plays a pivotal role in the metastatic progression of several human cancers; however, the precise mechanistic basis for its role remains unknown. Here, we define transitions between active (phosphorylated open) and inactive (dephosphorylated closed) forms of Ezrin that occur during metastatic progression in osteosarcoma. In our evaluation of these conformations we expressed C-terminal mutant forms of Ezrin that are open (phosphomimetic T567D) or closed (phosphodeficient T567A) and compared their biologic characteristics to full-length wild-type Ezrin in osteosarcoma cells. Unexpectedly, cells expressing open, active Ezrin could form neither primary orthotopic tumors nor lung metastases. In contrast, cells expressing closed, inactive Ezrin were also deficient in metastasis but were unaffected in their capacity for primary tumor growth. By imaging single metastatic cells in the lung, we found that cells expressing either open or closed Ezrin displayed increased levels of apoptosis early after their arrival in the lung. Gene expression analysis suggested dysregulation of genes that are functionally linked to carbohydrate and amino acid metabolism. In particular, cells expressing closed, inactive Ezrin exhibited reduced lactate production and basal or ATP-dependent oxygen consumption. Collectively, our results suggest that dynamic regulation of Ezrin phosphorylation at amino acid T567 that controls structural transitions of this protein plays a pivotal role in tumor progression and metastasis, possibly in part by altering cellular metabolism.

The ezrin metastatic phenotype is associated with the initiation of protein translation.

We previously associated the cytoskeleton linker protein, Ezrin, with the metastatic phenotype of pediatric sarcomas, including osteosarcoma and rhabdomyosarcoma. These studies have suggested that Ezrin contributes to the survival of cancer cells after their arrival at secondary metastatic locations. To better understand this role in metastasis, we undertook two noncandidate analyses of Ezrin function including a microarray subtraction of high-and low-Ezrin-expressing cells and a proteomic approach to identify proteins that bound the N-terminus of Ezrin in tumor lysates. Functional analyses of these data led to a novel and unifying hypothesis that Ezrin contributes to the efficiency of metastasis through regulation of protein translation. In support of this hypothesis, we found Ezrin to be part of the ribonucleoprotein complex to facilitate the expression of complex messenger RNA in cells and to bind with poly A binding protein 1 (PABP1; PABPC1). The relevance of these findings was supported by our identification of Ezrin and components of the translational machinery in pseudopodia of highly metastatic cells during the process of cell invasion. Finally, two small molecule inhibitors recently shown to inhibit the Ezrin metastatic phenotype disrupted the Ezrin/PABP1 association. Taken together, these results provide a novel mechanistic basis by which Ezrin may contribute to metastasis.