Local and dynamic regulation of neuronal glycolysis in vivo.

Energy metabolism supports neuronal function. While it is well established that changes in energy metabolism underpin brain plasticity and function, less is known about how individual neurons modulate their metabolic states to meet varying energy demands. This is because most approaches used to examine metabolism in living organisms lack the resolution to visualize energy metabolism within individual circuits, cells, or subcellular regions. Here, we adapted a biosensor for glycolysis, HYlight, for use in Caenorhabditis elegans to image dynamic changes in glycolysis within individual neurons and in vivo. We determined that neurons cell-autonomously perform glycolysis and modulate glycolytic states upon energy stress. By examining glycolysis in specific neurons, we documented a neuronal energy landscape comprising three general observations: 1) glycolytic states in neurons are diverse across individual cell types; 2) for a given condition, glycolytic states within individual neurons are reproducible across animals; and 3) for varying conditions of energy stress, glycolytic states are plastic and adapt to energy demands. Through genetic analyses, we uncovered roles for regulatory enzymes and mitochondrial localization in the cellular and subcellular dynamic regulation of glycolysis. Our study demonstrates the use of a single-cell glycolytic biosensor to examine how energy metabolism is distributed across cells and coupled to dynamic states of neuronal function and uncovers unique relationships between neuronal identities and metabolic landscapes in vivo.

Clinical Outcomes of Early Versus Late Enteral Nutrition Support in Critically Ill Trauma Patients With Isolated Traumatic Brain Injury.

INTRODUCTION: This study aims to compare the impact of early initiation of enteral feeding initiation on clinical outcomes in critically ill adult trauma patients with isolated traumatic brain injuries (TBI). METHODS: A retrospective cohort analysis of the American College of Surgeons Trauma Quality Program Participant Use File 2017-2021 dataset of critically ill adult trauma patients with moderate to severe blunt isolated TBI. Outcomes included ICU length of stay (ICU-LOS), ventilation-free days (VFD), and complication rates. Timing cohorts were defined as very early (<6 hours), early (6-24 hours), intermediate (24-48 hours), and late (>48 hours). RESULTS: 9210 patients were included in the analysis, of which 952 were in the very early enteral feeding initiation group, 652 in the early, 695 in intermediate, and 6938 in the late group. Earlier feeding was associated with significantly shorter ICU-LOS (very early: 7.82 days; early: 11.28; intermediate 12.25; late 17.55; P < .001) and more VFDs (very early: 21.72 days; early: 18.81; intermediate 18.81; late 14.51; P < .001). Patients with late EF had a significantly higher risk of VAP than very early (OR .21, CI 0.12-.38, P < .001) or early EF (OR .33, CI 0.17-.65, P = .001), and higher risk of ARDS than the intermediate group (OR .23, CI 0.05-.925, P = .039). CONCLUSION: Early enteral feeding in critically ill adult trauma patients with moderate to severe isolated TBI resulted in significantly fewer days in the ICU, more ventilation-free days, and lower odds of VAP and ARDS the sooner enteral feeding was initiated, with the most optimized outcomes within 6 hours.

Pediatric trauma population spine immobilization during resuscitation: A call for improved guidelines.

INTRODUCTION: This review aims to evaluate current practices regarding spine immobilization in pediatric trauma patients to evaluate their efficacy, reliability, and impact on clinical outcomes to guide future research and improved evidence-based practice guidelines. METHODS: PubMed, ProQuest, Embase, Google Scholar, and Cochrane were queried for studies pertaining to spinal immobilization practices in pediatric trauma patients. Articles were separated into studies that explored both the efficacy and clinical outcomes of spine immobilization. Outcomes evaluated included frequency of spinal imaging, self-reported pain level, emergency department length of stay (ED-LOS), and ED disposition. RESULTS: Six articles were included, with two studies examining clinical outcomes and 4 studies evaluating the efficacy and reliability of immobilization techniques. Immobilized children were significantly more likely to undergo cervical spine imaging (OR 8.2, p < 0.001), be admitted to the floor (OR 4.0, p < 0.001), be taken to the ICU or OR (OR 5.3, p < 0.05) and reported a higher median pain score. Older children were significantly more likely to be immobilized. No immobilization techniques consistently achieved neutral positioning, and patients most often presented in a flexed position. Lapses in immobilization occurred in 71.4% of patients. CONCLUSION: Immobilized pediatric patients underwent more cervical radiographs, and had higher hospital and ICU admission rates, and higher mean pain scores than those without immobilization. Immobilization was inconsistent across age groups and often resulted in lapses and improper alignment. Further research is needed to identify the most appropriate immobilization techniques for pediatric patients and when to use them.

Local and dynamic regulation of neuronal glycolysis in vivo.

Energy metabolism supports neuronal function. While it is well established that changes in energy metabolism underpin brain plasticity and function, less is known about how individual neurons modulate their metabolic states to meet varying energy demands. This is because most approaches used to examine metabolism in living organisms lack the resolution to visualize energy metabolism within individual circuits, cells, or subcellular regions. Here we adapted a biosensor for glycolysis, HYlight, for use in C. elegans to image dynamic changes in glycolysis within individual neurons and in vivo. We determined that neurons perform glycolysis cell-autonomously, and modulate glycolytic states upon energy stress. By examining glycolysis in specific neurons, we documented a neuronal energy landscape comprising three general observations: 1) glycolytic states in neurons are diverse across individual cell types; 2) for a given condition, glycolytic states within individual neurons are reproducible across animals; and 3) for varying conditions of energy stress, glycolytic states are plastic and adapt to energy demands. Through genetic analyses, we uncovered roles for regulatory enzymes and mitochondrial localization in the cellular and subcellular dynamic regulation of glycolysis. Our study demonstrates the use of a single-cell glycolytic biosensor to examine how energy metabolism is distributed across cells and coupled to dynamic states of neuronal function, and uncovers new relationships between neuronal identities and metabolic landscapes in vivo.

Cost-Effectiveness of Cell Salvage in Trauma Blood Transfusions.

INTRODUCTION: Despite the increasing amount of evidence supporting its use, cell salvage (CS) remains an underutilized resource in operative trauma care in many hospitals. We aim to evaluate the utilization of CS in adult trauma patients and associated outcomes to provide evidence-based recommendations. METHODS: A systematic review was conducted using PubMed, Google Scholar, and CINAHL. Articles evaluating clinical outcomes and the cost-effectiveness of trauma patients utilizing CS were included. The primary study outcome was mortality rates. The secondary outcomes included complication rates (sepsis and infection) and ICU-LOS. The tertiary outcome was the cost-effectiveness of CS. RESULTS: This systematic review included 9 studies that accounted for a total of 1119 patients that received both CS and allogeneic transfusion (n = 519), vs allogeneic blood transfusions only (n = 601). In-hospital mortality rates ranged from 13% to 67% in patients where CS was used vs 6%-65% in those receiving allogeneic transfusions only; however, these findings were not significantly different (P = .21-.56). Similarly, no significant differences were found between sepsis and infection rates or ICU-LOS in those patients where CS usage was compared to allogeneic transfusions alone. Of the 4 studies that provided comparisons on cost, 3 found the use of CS to be significantly more cost-effective. CONCLUSIONS: Cell salvage can be used as an effective method of blood transfusion for trauma patients without compromising patient outcomes, in addition to its possible cost advantages. Future studies are needed to further investigate the long-term effects of cell salvage utilization in trauma patients.

Traumatic Brain Injury, Electrolyte Levels, and Associated Outcomes: A Systematic Review.

INTRODUCTION: Although it has been established that electrolyte abnormalities are a consequence of traumatic brain injury (TBI), the degree to which electrolyte imbalances impact patient outcomes has not been fully established. We aim to determine the impact of sodium, potassium, calcium, and magnesium abnormalities on outcomes in patients with TBI. METHODS: Four databases were searched for studies related to the impact of electrolyte abnormalities on outcomes for TBI patients. Outcomes of interest were rates of mortality, Glasgow Outcome Scale (GOS), and intensive care unit length of stay (ICU-LOS). The search included studies published up to July 21, 2022. Articles were then screened and included if they met inclusion and exclusion criteria. RESULTS: In total, fourteen studies met inclusion and exclusion criteria for analysis in this systematic review. In patients with TBI, an increased mortality rate was associated with hypernatremia, hypokalemia, and hypocalcemia in the majority of studies. Both hyponatremia and hypomagnesemia were associated with worse GOS at 6 months. Whereas, both hyponatremia and hypernatremia were associated with increased ICU-LOS. There was no evidence to suggest other electrolyte imbalances were associated with either GOS or ICU-LOS. CONCLUSIONS: Hyponatremia and hypomagnesemia were associated with worse GOS. Hypernatremia was associated with increased mortality and ICU-LOS. Hypokalemia and hypocalcemia were associated with increased mortality. Given these findings, future practice guidelines should consider the effects of electrolytes' abnormalities on outcomes in TBI patients prior to establishing management strategies.

Monitoring glycolytic dynamics in single cells using a fluorescent biosensor for fructose 1,6-bisphosphate.

Cellular metabolism is regulated over space and time to ensure that energy production is efficiently matched with consumption. Fluorescent biosensors are useful tools for studying metabolism as they enable real-time detection of metabolite abundance with single-cell resolution. For monitoring glycolysis, the intermediate fructose 1,6-bisphosphate (FBP) is a particularly informative signal as its concentration is strongly correlated with flux through the whole pathway. Using GFP insertion into the ligand-binding domain of the Bacillus subtilis transcriptional regulator CggR, we developed a fluorescent biosensor for FBP termed HYlight. We demonstrate that HYlight can reliably report the real-time dynamics of glycolysis in living cells and tissues, driven by various metabolic or pharmacological perturbations, alone or in combination with other physiologically relevant signals. Using this sensor, we uncovered previously unknown aspects of ß-cell glycolytic heterogeneity and dynamics.

A Sort-Seq Approach to the Development of Single Fluorescent Protein Biosensors.

Motivated by the growing importance of single fluorescent protein biosensors (SFPBs) in biological research and the difficulty in rationally engineering these tools, we sought to increase the rate at which SFPB designs can be optimized. SFPBs generally consist of three components: a circularly permuted fluorescent protein, a ligand-binding domain, and linkers connecting the two domains. In the absence of predictive methods for biosensor engineering, most designs combining these three components will fail to produce allosteric coupling between ligand binding and fluorescence emission. While methods to construct diverse libraries with variation in the site of GFP insertion and linker sequences have been developed, the remaining bottleneck is the ability to test these libraries for functional biosensors. We address this challenge by applying a massively parallel assay termed "sort-seq," which combines binned fluorescence-activated cell sorting, next-generation sequencing, and maximum likelihood estimation to quantify the brightness and dynamic range for many biosensor variants in parallel. We applied this method to two common biosensor optimization tasks: the choice of insertion site and optimization of linker sequences. The sort-seq assay applied to a maltose-binding protein domain-insertion library not only identified previously described high-dynamic-range variants but also discovered new functional insertion sites with diverse properties. A sort-seq assay performed on a pyruvate biosensor linker library expressed in mammalian cell culture identified linker variants with substantially improved dynamic range. Machine learning models trained on the resulting data can predict dynamic range from linker sequences. This high-throughput approach will accelerate the design and optimization of SFPBs, expanding the biosensor toolbox.

Injury characteristics of the Pulse Nightclub shooting: Lessons for mass casualty incident preparation.

BACKGROUND: On the morning of June 12, 2016, an armed assailant entered the Pulse Nightclub in Orlando, Florida, and initiated an assault that killed 49 people and injured 53. The regional Level I trauma center and two community hospitals responded to this mass casualty incident. A detailed analysis was performed to guide hospitals who strive to prepare for future similar events. METHODS: A retrospective review of all victim charts and/or autopsy reports was performed to identify victim presentation patterns, injuries sustained, and surgical resources required. Patients were stratified into three groups: survivors who received care at the regional Level I trauma center, survivors who received care at one of two local community hospitals, and decedents. RESULTS: Of the 102 victims, 40 died at the scene and 9 died upon arrival to the Level I trauma center. The remaining 53 victims received definitive medical care and survived. Twenty-nine victims were admitted to the trauma center and five victims to a community hospital. The remaining 19 victims were treated and discharged that day. Decedents sustained significantly more bullet impacts than survivors (4 ± 3 vs. 2 ± 1; p = 0.008) and body regions injured (3 ± 1 vs. 2 ± 1; p = 0.0002). Gunshots to the head, chest, and abdominal body regions were significantly more common among decedents than survivors (p < 0.0001). Eighty-two percent of admitted patients required surgery in the first 24 hours. Essential resources in the first 24 hours included trauma surgeons, emergency room physicians, orthopedic/hand surgeons, anesthesiologists, vascular surgeons, interventional radiologists, intensivists, and hospitalists. CONCLUSION: Mass shooting events are associated with high mortality. Survivors commonly sustain multiple, life-threatening ballistic injuries requiring emergent surgery and extensive hospital resources. Given the increasing frequency of mass shootings, all hospitals must have a coordinated plan to respond to a mass casualty event. LEVEL OF EVIDENCE: Epidemiological Study, level V.

Pharmacological bypass of NAD+ salvage pathway protects neurons from chemotherapy-induced degeneration.

Axon degeneration, a hallmark of chemotherapy-induced peripheral neuropathy (CIPN), is thought to be caused by a loss of the essential metabolite nicotinamide adenine dinucleotide (NAD+) via the prodegenerative protein SARM1. Some studies challenge this notion, however, and suggest that an aberrant increase in a direct precursor of NAD+, nicotinamide mononucleotide (NMN), rather than loss of NAD+, is responsible. In support of this idea, blocking NMN accumulation in neurons by expressing a bacterial NMN deamidase protected axons from degeneration. We hypothesized that protection could similarly be achieved by reducing NMN production pharmacologically. To achieve this, we took advantage of an alternative pathway for NAD+ generation that goes through the intermediate nicotinic acid mononucleotide (NAMN), rather than NMN. We discovered that nicotinic acid riboside (NAR), a precursor of NAMN, administered in combination with FK866, an inhibitor of the enzyme nicotinamide phosphoribosyltransferase that produces NMN, protected dorsal root ganglion (DRG) axons against vincristine-induced degeneration as well as NMN deamidase. Introducing a different bacterial enzyme that converts NAMN to NMN reversed this protection. Collectively, our data indicate that maintaining NAD+ is not sufficient to protect DRG neurons from vincristine-induced axon degeneration, and elevating NMN, by itself, is not sufficient to cause degeneration. Nonetheless, the combination of FK866 and NAR, which bypasses NMN formation, may provide a therapeutic strategy for neuroprotection.

Nonoperative management rather than endovascular repair may be safe for grade II blunt traumatic aortic injuries: An 11-year retrospective analysis.

BACKGROUND: The Society of Vascular Surgery (SVS) guidelines currently suggest thoracic endovascular aortic repair (TEVAR) for grade II-IV and nonoperative management (NOM) for grade I blunt traumatic aortic injury (BTAI). However, there is increasing evidence that grade II may also be observed safely. The purpose of this study was to compare the outcome of TEVAR and NOM for grade I-IV BTAI and determine if grade II can be safely observed with NOM. METHODS: The records of patients with BTAI from 2004 to 2015 at a Level I trauma center were retrospectively reviewed. Patients were separated into two groups: TEVAR versus NOM. All BTAIs were graded according to the SVS guidelines. Minimal aortic injury (MAI) was defined as BTAI grade I and II. Failure of NOM was defined as aortic rupture after admission or progression on subsequent computed tomography (CT) imaging requiring TEVAR or open thoracotomy repair (OTR). Statistical analysis was performed using Mann-Whitney U and χ tests. RESULTS: A total of 105 adult patients (≥16 years) with BTAI were identified over the 11-year period. Of these, 17 patients who died soon after arrival and 17 who underwent OTR were excluded. Of the remaining 71 patients, 30 had MAI (14 TEVAR vs. 16 NOM). There were no failures in either group. No patients with MAI in either group died from complications of aortic lesions. Follow-up CT imaging was performed on all MAI patients. Follow-up CT scans for all TEVAR patients showed stable stents with no leak. Follow-up CT in the NOM group showed progression in two patients neither required subsequent OTR or TEVAR. CONCLUSIONS: Although the SVS guidelines suggest TEVAR for grade II-IV and NOM for grade I BTAI, NOM may be safely used in grade II BTAI. LEVEL OF EVIDENCE: Therapeutic study, level IV.

Laparoscopic Appendectomy Protocol Expedites Management of Uncomplicated Acute Appendicitis.

Bed availability remains a constant struggle for tertiary care centers resulting in the use of management protocols to streamline patient care and reduce length of stay (LOS). A standardized perioperative management protocol for uncomplicated acute appendicitis (UA) was implemented in April 2014 to decrease both CT scan usage and LOS. Patients who underwent laparoscopic appendectomy for UA from April 2012 to May 2013 (PRE group) and April 2014 to May 2015 (POST group) were compared retrospectively. There were no differences in patient demographics or clinical findings between the groups. All patients in the PRE group had a CT scan for the diagnosis of appendicitis, whereas there was a 14 per cent decrease in the POST group (P = 0.002). There was a significant decrease in median LOS between the groups [PRE 1.3 vs POST 0.9 days; (P < 0.001)]. There was no difference in subsequent emergency department visits for complications [3 (4%) vs 4 (4%); P = 1.0] or 30-day readmission rate [1 (1%) vs 5 (5%); P = 0.22] between the groups. A standardized perioperative management protocol for UA patients significantly decreased CT scan utilization and LOS without compromising patient care.

Management of the Open Abdomen in Obese Trauma Patients.

Obesity incidence in the trauma population is increasing. Abdominal compartment syndrome has poor outcomes when left untreated. Surgeons may treat obese patients differently because of concern for increased morbidity and mortality. We studied the effects of body mass index (BMI) on resource utilization and outcome. An Institutional Review Board-approved retrospective review of trauma patients requiring temporary abdominal closure (TAC) was performed. Patients were stratified as follows: Group 1-BMI = 18.5 to 24.9 kg/m(2), Group 2-BMI = 25 to 29.9 kg/m(2), Group 3-BMI = 30 to 39.9 kg/m(2), Group 4-BMI ≥ 40 kg/m(2). Demographic data, illness severity as defined by Injury Severity Score, Acute Physiology and Chronic Health Evaluation Score Version II and Simplified Acute Physiology Score Version II scores, resource utilization, fascial closure rate, and survival were collected. About 380 patients required TAC. Median age of Group 1 was significantly lower than Groups 2 and 3 (P = 0.001). Severity of illness did not differ. Group 4 had a longer intensive care unit stay compared with Groups 1 and 2 (P = 0.005). Group 4 required mechanical ventilation longer than Group 1 (P = 0.027). Hospital stay, fascial closure, and survival were equivalent. Obese trauma patients with TAC have a longer intensive care unit stay and more ventilator days, but there is no difference in survival or type of closure. TAC can be used safely in trauma patients with a BMI ≥ 30 kg/m(2).

Early intravenous ibuprofen decreases narcotic requirement and length of stay after traumatic rib fracture.

Pain control after traumatic rib fracture is essential to avoid respiratory complications and prolonged hospitalization. Narcotics are commonly used, but adjunctive medications such as nonsteroidal anti-inflammatory drugs may be beneficial. Twenty-one patients with traumatic rib fractures treated with both narcotics and intravenous ibuprofen (IVIb) (Treatment) were retrospectively compared with 21 age- and rib fracture-matched patients who received narcotics alone (Control). Pain medication requirements over the first 7 hospital days were evaluated. Mean daily IVIb dose was 2070 ± 880 mg. Daily intravenous morphine-equivalent requirement was 19 ± 16 vs 32 ± 24 mg (P < 0.0001). Daily narcotic requirement was significantly decreased in the Treatment group on Days 3 through 7 (P < 0.05). Total weekly narcotic requirement was significantly less among Treatment patients (P = 0.004). Highest and lowest daily pain scores were lower in the Treatment group (P < 0.05). Hospital length of stay was 4.4 ± 3.4 versus 5.4 ± 2.9 days (P = 0.32). There were no significant complications associated with IVIb therapy. Early IVIb therapy in patients with traumatic rib fractures significantly decreases narcotic requirement and results in clinically significant decreases in hospital length of stay. IVIb therapy should be initiated in patients with traumatic rib fractures to improve patient comfort and reduce narcotic requirement.

Intra-abdominal hypertension and abdominal compartment syndrome in the medical patient.

Critically ill medical patients are at significant risk for developing intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS). Although surgical IAH/ACS is commonly acute and dramatic in onset, medical IAH/ACS is more slow and insidious in its development but no less deadly. The presence of pre-existing comorbid illnesses among medical patients imparts morbidity and mortality rates that are significantly greater than those of their surgical counterparts. A variety of effective medical management strategies for reducing elevated intra-abdominal pressure (IAP), coupled with early abdominal decompression when necessary, has been demonstrated to significantly improve patient survival from IAH/ACS. Serial IAP measurements, increased collaboration between surgeon and nonsurgeon, institution of medical management strategies, and early abdominal decompression for refractory IAH/ACS will lead to decreased rates of organ failure and improved survival for medical patients who develop IAH/ACS.

Traumatic renal artery occlusion in a patient with a solitary kidney: case report of treatment with endovascular stent and review of the literature.

Renal artery occlusion after blunt trauma is a rare occurrence, and the optimal treatment for this condition has not been established. To our knowledge, endovascular repair for blunt renal artery occlusion in a solitary kidney has not been described in the literature. This case report describes a 42-year-old woman with a solitary left kidney presenting with total occlusion of the left renal artery after a significant crush injury. She was successfully treated by percutaneous placement of an endovascular stent. Postprocedure, the patient developed acute renal failure requiring temporary dialysis. At follow-up 4 months later, the patient has normal urinary output and a normal creatinine.

Pancreaticoduodenectomy in a community general surgery residency program.

The morbidity and mortality of pancreaticoduodenectomy (PD) has been well documented. A retrospective review was performed to determine the morbidity and mortality of PD performed within the general surgery residency program of a tertiary community hospital. Patients undergoing PD for benign or malignant disease over a 6-year period were analyzed to determine overall mortality, major complication rate, and length of stay (LOS). Of 50 consecutive patients undergoing PD, overall mortality was 6 per cent, with a major complication rate of 52 per cent. Mean operative time was 333 +/- 68 minutes with an estimated blood loss of 459 +/- 301 mL. Mean hospital LOS was 21 +/- 13 days. Eighty-four per cent of patients with malignant disease had negative margins of resection. General surgery residents within a community residency program, with attending faculty supervision, can perform PD with mortality, morbidity, and LOS comparable with that reported in the university setting.

Fracture of Bilok interference screws on insertion during anterior cruciate ligament reconstruction.

New femoral and tibial interference screws for use during anterior cruciate ligament (ACL) reconstruction have been developed using a composite of poly-L-lactic acid (PLLA) and tricalcium phosphate (TCP). The combination is described as having better incorporation than standard bioabsorbable screws with no loss of mass during incorporation and without the brittle nature associated with conventional TCP implants. However, the screw can fracture during insertion, leaving the distal third inside the femoral or tibial tunnel, making extraction and revision difficult. This is a report of 2 cases of PLLA-TCP screw breakage, 1 occurring in the femoral tunnel and 1 occurring in the tibial tunnel.