Vip1 is a kinase and pyrophosphatase switch that regulates inositol diphosphate signaling.

Inositol diphosphates (PP-IPs), also known as inositol pyrophosphates, are high-energy cellular signaling codes involved in nutrient and regulatory responses. We report that the evolutionarily conserved gene product, Vip1, possesses autonomous kinase and pyrophosphatase domains capable of synthesis and destruction of D-1 PP-IPs. Our studies provide atomic-resolution structures of the PP-IP products and unequivocally define that the Vip1 gene product is a highly selective 1-kinase and 1-pyrophosphatase enzyme whose activities arise through distinct active sites. Kinetic analyses of kinase and pyrophosphatase parameters are consistent with Vip1 evolving to modulate levels of 1-IP7 and 1,5-IP8 Individual perturbations in kinase and pyrophosphatase activities in cells result in differential effects on vacuolar morphology and osmotic responses. Analogous to the dual-functional key energy metabolism regulator, phosphofructokinase 2, Vip1 is a kinase and pyrophosphatase switch whose 1-PP-IP products play an important role in a cellular adaptation.

A capaciflector provides continuous and accurate respiratory rate monitoring for patients at rest and during exercise.

Respiratory rate (RR) is a marker of critical illness, but during hospital care, RR is often inaccurately measured. The capaciflector is a novel sensor that is small, inexpensive, and flexible, thus it has the potential to provide a single-use, real-time RR monitoring device. We evaluated the accuracy of continuous RR measurements by capaciflector hardware both at rest and during exercise. Continuous RR measurements were made with capaciflectors at four chest locations. In healthy subjects (n = 20), RR was compared with strain gauge chest belt recordings during timed breathing and two different body positions at rest. In patients undertaking routine cardiopulmonary exercise testing (CPET, n = 50), RR was compared with pneumotachometer recordings. Comparative RR measurement bias and limits of agreement were calculated and presented in Bland-Altman plots. The capaciflector was shown to provide continuous RR measurements with a bias less than 1 breath per minute (BPM) across four chest locations. Accuracy and continuity of monitoring were upheld even during vigorous CPET exercise, often with narrower limits of agreement than those reported for comparable technologies. We provide a unique clinical demonstration of the capaciflector as an accurate breathing monitor, which may have the potential to become a simple and affordable medical device.Clinical trial number: NCT03832205 https://clinicaltrials.gov/ct2/show/NCT03832205 registered February 6th, 2019.

A carbon monoxide 'single breath' method to measure total haemoglobin mass: a feasibility study.

NEW FINDINGS: What is the central question of this study? Is it possible to modify the CO-rebreathing method to acquire reliable measurements of haemoglobin mass in ventilated patients? What is the main finding and its importance? A 'single breath' of CO with a subsequent 30 s breath hold provides almost as exact a measure of haemoglobin mass as the established optimized CO-rebreathing method when applied to healthy subjects. The modified method has now to be checked in ventilated patients before it can be used to quantify the contributions of blood loss and of dilution to the severity of anaemia. ABSTRACT: Anaemia is defined by the concentration of haemoglobin (Hb). However, this value is dependent upon both the total circulating haemoglobin mass (tHb-mass) and the plasma volume (PV) - neither of which is routinely measured. Carbon monoxide (CO)-rebreathing methods have been successfully used to determine both PV and tHb-mass in various populations. However, these methods are not yet suitable for ventilated patients. This study aimed to modify the CO-rebreathing procedure such that a single inhalation of a CO bolus would enable its use in ventilated patients. Eleven healthy volunteers performed four CO-rebreathing tests in a randomized order, inhaling an identical CO volume. In two tests, CO was rebreathed for 2 min (optimized CO rebreathing; oCOR), and in the other two tests, a single inhalation of a CO bolus was conducted with a subsequent breath hold of 15 s (Procnew 15s) or 30 s (Procnew 30s). Subsequently, the CO volume in the exhaled air was continuously determined for 20 min. The amount of CO exhaled after 7 and 20 min was respectively 3.1 ± 0.3 and 5.9 ± 1.1 ml for oCOR, 8.7 ± 3.6 and 12.0 ± 4.4 ml for Procnew 15s and 5.1 ± 2.0 and 8.4 ±2.6 ml for Procnew 30s. tHb-mass was 843 ± 293 g determined by oCOR, 821 ± 288 g determined by Procnew 15s (difference: P < 0.05) and 849 ± 311 g determined by Procnew 30s. Bland-Altman plots demonstrated slightly lower tHb-mass values for Procnew 15s compared with oCOR (-21.8 ± 15.3 g) and similar values for Procnew 30s. In healthy volunteers, a single inhalation of a CO bolus, preferably followed by a 30 s breath hold, can be used to determine tHb-mass. These results must now be validated for ventilated patients.

Proteomic Analysis of Infants Undergoing Cardiopulmonary Bypass Using Contemporary Ontological Tools.

BACKGROUND: Cardiopulmonary bypass (CPB) is essential for the repair of many congenital cardiac defects in infants but is associated with significant derangements in hemostasis and systemic inflammation. As a result, hemorrhagic complications and thrombosis are major challenges in the management of children requiring CPB or extracorporeal membrane oxygenation. Conventional clinical laboratory tests capture individual hemostatic derangements (low platelets, elevated fibrinogen) but fail to describe the complex, overlapping interactions among the various components of coagulation, including cellular interactions, contact activation, fibrinolysis, and inflammation. Given recent advances in analytic tools for identifying protein-protein interactions in the plasma proteome, we hypothesized that an unbiased proteomic analysis would help identify networks of interacting proteins for further investigation in pediatric CPB. MATERIALS AND METHODS: Infants up to 1 y of age were enrolled. Plasma samples were collected at 0, 1, 4, and 24 h after CPB. Mass spectrometry was used to identify proteins undergoing changes in concentration after CPB, and STRING and ToppGene tools were used to identify biological networks. Two-dimensional difference gel electrophoresis identified changes in protein concentrations. Inflammatory markers were assessed by enzyme-linked immunosorbent assay at the same time points. RESULTS: Ten infants with cardiac anomalies requiring surgery and CPB were enrolled; no major complications were recorded (median age, 127.5 d; interquartile range, 181.25 d). Using two-dimensional difference gel electrophoresis, >1400 individual protein spots were observed, and 89 proteins demonstrated change in concentration >30% with P < 0.02 when comparing 1, 4, or 24 h to baseline. Among protein spots with significant changes in concentration after CPB, 29 were identified with mass spectrometry (33%). In our interrogation of functional associations among these differentially expressed proteins, our results were dominated by the acute phase response, coagulation, and cell signaling functional categories. Among cytokines analyzed by enzyme-linked immunosorbent assay, IL-2, IL-8, and IL-10 were elevated at 4 h but normalized by 24 h, whereas IL-6 was persistently elevated. CONCLUSIONS: Infants manifest a robust response to CPB that includes overlapping, complex pathways. Further investigation of interactions among immune, coagulation, and cell signaling systems may lead to novel therapeutics or biomarkers useful in the management of infants requiring CPB.

Coagulopathy Characterized by Rotational Thromboelastometry in a Porcine Pediatric ECMO Model.

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is used to support patients with reversible cardiopulmonary insufficiency. Although it is a lifesaving technology, bleeding, inflammation, and thrombosis are well-described complications of ECMO. Adult porcine models of ECMO have been used to recapitulate the physiology and hemostatic consequences of ECMO cannulation in adults. However, these models lack the unique physiology and persistence of fetal forms of coagulation factors and fibrinogen as in human infants. We aimed to describe physiologic and coagulation parameters of piglets cannulated and supported with VA-ECMO. Four healthy piglets (5.7-6.4 kg) were cannulated via jugular vein and carotid artery by cutdown and supported for a maximum of 20 hours. Heparin was used with a goal activated clotting time of 180-220 seconds. Arterial blood gas (ABG) was performed hourly, and blood was transfused from an adult donor to maintain hematocrit (Hct) > 24%. Rotational thromboelastometry (ROTEM) was performed at seven time points. All animals achieved adequate flow with a patent circuit throughout the run (pre- and post-oxygenator pressure gradient <10 mmHg). There was slow but significant hemorrhage at cannulation, arterial line, and bladder catheter sites. All animals required the maximum blood transfusion volume available. All animals became anemic after exhaustion of blood for transfusion. ABG showed progressively declining Hct and adequate oxygenation. ROTEM demonstrated decreasing fibrin-only ROTEM (FIBTEM) clot firmness. Histology was overall unremarkable. Pediatric swine are an important model for the study of pediatric ECMO. We have demonstrated the feasibility of such a model while providing descriptions of physiologic, hematologic, and coagulation parameters throughout. Weak whole-blood clot firmness by ROTEM suggested defects in fibrinogen, and there was a clinical bleeding tendency in all animals studied. This model serves as an important means to study the complex derangements in hemostasis during ECMO.

Routine postprocedure ultrasound increases rate of detection of femoral arterial thrombosis in infants after cardiac catheterization.

OBJECTIVES: To examine the effect of implementing postcatheterization ultrasound (US) on femoral arterial thrombosis detection rates and factors associated with thrombosis in infants. BACKGROUND: Although femoral arterial thrombosis is an uncommon complication of cardiac catheterization, it can cause limb threatening complications. Previous studies assessing the utility of postprocedure US to detect thrombosis in infants have utilized US as an adjunct to standard clinical detection methods, are small scale, or include small cohorts of infants within older populations. METHODS: We reviewed institutional records of patients 0-12 months undergoing catheterization from 2007 to 2016. Demographics and procedural data were compared between the thrombosis and non-thrombosis group. Pre- and post-US groups were compared for detected thrombosis rate. Using univariate and multivariable analyses, we identified factors associated with thrombosis. RESULTS: In total, 270 patients underwent 509 catheterizations, with 40 (7.9%) documented thromboses. The rate of thrombus detection in patients younger than 6 months increased from 8.3% to 23.4% (P = 0.006) after implementing routine US. On multivariable analysis, lower weight (P < 0.001), larger arterial sheath size (P < 0.001), and longer procedure duration (P = 0.003) were independently associated with higher odds of thrombosis. CONCLUSIONS: Higher rates of femoral arterial thrombosis detection were observed since implementing an US screening program. Further studies are needed to evaluate age-related changes in hemostasis in this population and how advanced screening methods and anticoagulation protocols may help improve short-term and long-term sequelae of femoral arterial thrombosis.

Hemoglobin concentration, total hemoglobin mass and plasma volume in patients: implications for anemia.

In practice, clinicians generally consider anemia (circulating hemoglobin concentration < 120 g.l-1 in non-pregnant females and < 130 g.l-1 in males) as due to impaired hemoglobin synthesis or increased erythrocyte loss or destruction. Rarely is a rise in plasma volume relative to circulating total hemoglobin mass considered as a cause. But does this matter? We explored this issue in patients, measuring hemoglobin concentration, total hemoglobin mass (optimized carbon monoxide rebreathing method) and thereby calculating plasma volume in healthy volunteers, surgical patients, and those with inflammatory bowel disease, chronic liver disease or heart failure. We studied 109 participants. Hemoglobin mass correlated well with its concentration in the healthy, surgical and inflammatory bowel disease groups (r=0.687-0.871, P<0.001). However, they were poorly related in liver disease (r=0.410, P=0.11) and heart failure patients (r=0.312, P=0.16). Here, hemoglobin mass explained little of the variance in its concentration (adjusted R2=0.109 and 0.052; P=0.11 and 0.16), whilst plasma volume did (R2 change 0.724 and 0.805 in heart and liver disease respectively, P<0.0001). Exemplar patients with identical (normal or raised) total hemoglobin masses were diagnosed as profoundly anemic (or not) depending on differences in plasma volume that had not been measured or even considered as a cause. The traditional inference that anemia generally reflects hemoglobin deficiency may be misleading, potentially resulting in inappropriate tests and therapeutic interventions to address 'hemoglobin deficiency' not 'plasma volume excess'. Measurement of total hemoglobin mass and plasma volume is now simple, cheap and safe, and its more routine use is advocated.

Tissue engineered vascular grafts: Origins, development, and current strategies for clinical application.

Since the development of a dependable and durable synthetic non-autogenous vascular conduit in the mid-twentieth century, the field of vascular surgery has experienced tremendous growth. Concomitant with this growth, development in the field of bioengineering and the development of different tissue engineering techniques have expanded the armamentarium of the surgeon for treating a variety of complex cardiovascular diseases. The recent development of completely tissue engineered vascular conduits that can be implanted for clinical application is a particularly exciting development in this field. With the rapid advances in the field of tissue engineering, the great hope of the surgeon remains that this conduit will function like a true blood vessel with an intact endothelial layer, with the ability to respond to endogenous vasoactive compounds. Eventually, these engineered tissues may have the potential to supplant older organic but not truly biologic technologies, which are used currently.

Cardiopulmonary exercise testing before and after intravenous iron in preoperative patients: a prospective clinical study.

BACKGROUND: Anemia is associated with impaired physical performance and adverse perioperative outcomes. Iron-deficiency anemia is increasingly treated with intravenous iron before elective surgery. We explored the relationship between exercise capacity, anemia, and total hemoglobin mass (tHb-mass) and the response to intravenous iron in anemic patients prior to surgery. METHODS: A prospective clinical study was undertaken in patients having routine cardiopulmonary exercise testing (CPET) with a hemoglobin concentration ([Hb]) < 130 g.l-1 and iron deficiency/depletion. Patients underwent CPET and tHb-mass measurements before and a minimum of 14 days after receiving intravenous (i.v.) Ferric derisomaltose (Monofer®) at the baseline visit. Comparative analysis of hematological and CPET variables was performed pre and post-iron treatment. RESULTS: Twenty-six subjects were recruited, of whom 6 withdrew prior to study completion. The remaining 20 (9 [45%] male; mean ± SD age 68 ± 10 years) were assessed 25 ± 7 days between baseline and the final visit. Following i.v. iron, increases were seen in [Hb] (mean ± SD) from 109 ± 14 to 116 ± 12 g l-1 (mean rise 6.4% or 7.3 g l-1, p = < 0.0001, 95% CI 4.5-10.1); tHb-mass from 497 ± 134 to 546 ± 139 g (mean rise 9.3% or 49 g, p = < 0.0001, 95% CI 29.4-69.2). Oxygen consumption at anerobic threshold ([Formula: see text] O2 AT) did not change (9.1 ± 1.7 to 9.8 ± 2.5 ml kg-1 min-1, p = 0.09, 95% CI - 0.13 - 1.3). Peak oxygen consumption ([Formula: see text] O2 peak) increased from 15.2 ± 4.1 to 16 ± 4.4 ml.kg.-1 min-1, p = 0.02, 95% CI 0.2-1.8) and peak work rate increased from 93 [67-112] watts to 96 [68-122] watts (p = 0.02, 95% CI 1.3-10.8). CONCLUSION: Preoperative administration of intravenous iron to iron-deficient/deplete anemic patients is associated with increases in [Hb], tHb-mass, peak oxygen consumption, and peak work rate. Further appropriately powered prospective studies are required to ascertain whether improvements in tHb-mass and performance in turn lead to reductions in perioperative morbidity. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT 033 46213.

Individualised Exercise Training Enhances Antioxidant Buffering Capacity in Idiopathic Pulmonary Fibrosis.

Exercise training is recommended for patients with idiopathic pulmonary fibrosis (IPF); however, the mechanism(s) underlying its physiological benefits remain unclear. We investigated the effects of an individualised aerobic interval training programme on exercise capacity and redox status in IPF patients. IPF patients were recruited prospectively to an 8-week, twice-weekly cardiopulmonary exercise test (CPET)-derived structured responsive exercise training programme (SRETP). Systemic redox status was assessed pre- and post-CPET at baseline and following SRETP completion. An age- and sex-matched non-IPF control cohort was recruited for baseline comparison only. At baseline, IPF patients (n = 15) had evidence of increased oxidative stress compared with the controls as judged by; the plasma reduced/oxidised glutathione ratio (median, control 1856 vs. IPF 736 p = 0.046). Eleven IPF patients completed the SRETP (median adherence 88%). Following SRETP completion, there was a significant improvement in exercise capacity assessed via the constant work-rate endurance time (+82%, p = 0.003). This was accompanied by an improvement in post-exercise redox status (in favour of antioxidants) assessed via serum total free thiols (median increase, +0.26 µmol/g protein p = 0.005) and total glutathione concentration (+0.73 µM p = 0.03), as well as a decrease in post-exercise lipid peroxidation products (-1.20 µM p = 0.02). Following SRETP completion, post-exercise circulating nitrite concentrations were significantly lower compared with baseline (-0.39 µM p = 0.04), suggestive of exercise-induced nitrite utilisation. The SRETP increased both endurance time and systemic antioxidant capacity in IPF patients. The observed reduction in nitrite concentrations provides a mechanistic rationale to investigate nitrite/nitrate supplementation in IPF patients.

Pro-inflammatory macrophages impair skeletal muscle regeneration in ischemic-damaged limbs by inducing precocious differentiation of satellite cells.

Chronic limb-threatening ischemia (CLTI), representing the end-stage of peripheral arterial disease (PAD), is associated with a one-year limb amputation rate of ∻15-20% and significant mortality. A key characteristic of CLTI is the failure of the innate regenerative capacity of skeletal muscle, though the underlying mechanisms remain unclear. Here, single-cell transcriptome analysis of ischemic and non-ischemic muscle from the same CLTI patients demonstrated that ischemic-damaged tissue is enriched with pro-inflammatory macrophages. Comparable results were also observed in a murine CLTI model. Importantly, integrated analyses of both human and murine data revealed premature differentiation of muscle satellite cells (MuSCs) in damaged tissue and indications of defects in intercellular signaling communication between MuSCs and their inflammatory niche. Collectively, our research provides the first single-cell transcriptome atlases of skeletal muscle from CLTI patients and murine models, emphasizing the crucial role of macrophages and inflammation in regulating muscle regeneration in CLTI through interactions with MuSCs.

Skeletal muscle regeneration failure in ischemic-damaged limbs is associated with pro-inflammatory macrophages and premature differentiation of satellite cells.

BACKGROUND: Chronic limb-threatening ischemia (CLTI), a severe manifestation of peripheral arterial disease (PAD), is associated with a 1-year limb amputation rate of approximately 15-20% and substantial mortality. A key feature of CLTI is the compromised regenerative ability of skeletal muscle; however, the mechanisms responsible for this impairment are not yet fully understood. In this study, we aim to delineate pathological changes at both the cellular and transcriptomic levels, as well as in cell-cell signaling pathways, associated with compromised muscle regeneration in limb ischemia in both human tissue samples and murine models of CLTI. METHODS: We performed single-cell transcriptome analysis of ischemic and non-ischemic muscle from the same CLTI patients and from a murine model of CLTI. In both datasets, we analyzed gene expression changes in macrophage and muscle satellite cell (MuSC) populations as well as differential cell-cell signaling interactions and differentiation trajectories. RESULTS: Single-cell transcriptomic profiling and immunofluorescence analysis of CLTI patient skeletal muscle demonstrated that ischemic-damaged tissue displays a pro-inflammatory macrophage signature. Comparable results were observed in a murine CLTI model. Moreover, integrated analyses of both human and murine datasets revealed premature differentiation of MuSCs to be a key feature of failed muscle regeneration in the ischemic limb. Furthermore, in silico inferences of intercellular communication and in vitro assays highlight the importance of macrophage-MuSC signaling in ischemia induced muscle injuries. CONCLUSIONS: Collectively, our research provides the first single-cell transcriptome atlases of skeletal muscle from CLTI patients and a murine CLTI model, emphasizing the crucial role of macrophages and inflammation in regulating muscle regeneration in CLTI through interactions with MuSCs.

Changing the game: what CFOs should know about physician compensation.

Healthcare CFOs should ask three critical questions in determining the right approach to physician compensation: How will market characteristics influence physician compensation? To what extent should base salaries and incentives be used to compensate physicians? How should the organization's physician compensation package be structured?

Aptamer-based factor IXa inhibition preserves hemostasis and prevents thrombosis in a piglet model of ECMO.

Extracorporeal membrane oxygenation (ECMO) requires anticoagulation to prevent clotting when the patient's blood contacts the circuit. Unfractionated heparin (UFH) usually prevents clotting but can cause life-threatening bleeding. An anticoagulant that selectively inhibits the contact activation (intrinsic) pathway while sparing the tissue factor (extrinsic) pathway of coagulation might prevent clotting triggered by the circuit while permitting physiologic coagulation at surgical sites. DTRI-178 is an RNA anticoagulant aptamer conjugated to polyethylene glycol that increases its half-life in circulation. This aptamer is based on a previously described molecule (9.3t) that inhibits intrinsic tenase activity by binding to factor IXa on an exosite. Using a piglet model of pediatric venoarterial (VA) ECMO, we compared thromboprevention and blood loss using a single dose of DTRI-178 versus UFH. In each of five experiments, we subjected two litter-matched piglets, one anticoagulated with DTRI-178 and the other with UFH, to simultaneous 12-h periods of VA ECMO. Both anticoagulants achieved satisfactory and comparable thromboprotection. However, UFH piglets had increased surgical site bleeding and required significantly greater blood transfusion volumes than piglets anticoagulated with DTRI-178. Our results indicate that DTRI-178, an aptamer against factor IXa, may be feasible, safer, and result in fewer transfusions and clinical bleeding events in ECMO.

AbobotulinumtoxinA Versus OnabotulinumtoxinA in Adults with Upper Limb Spasticity: A Randomized, Double-Blind, Crossover Study Protocol.

INTRODUCTION: The safety and efficacy of both abobotulinumtoxinA and onabotulinumtoxinA for upper limb spasticity are well established, but head-to-head comparisons are lacking. METHODS: DIRECTION is an international, randomized, double-blind, crossover study comparing the safety and efficacy of abobotulinumtoxinA with onabotulinumtoxinA in the management of upper limb spasticity at doses at or near maximum recommended in product labelling. Participants (18-75 years) will be randomized (1:1) to either one cycle of abobotulinumtoxinA (900U) followed by onabotulinumtoxinA (360U) or vice versa. To maintain blinding, a fixed volume (3.6 ml) will be injected into the target upper limb muscles (four wrist and finger flexors and biceps brachii). The second treatment cycle will begin at Week 12 if retreatment criteria are fulfilled, and if not, they will be reassessed every 4 weeks until they meet retreatment parameters. PLANNED OUTCOMES: The primary hypothesis is that there is comparable safety between products; non-inferiority will be tested based on treatment-emergent adverse event (TEAE) rates from injection to Week 12. A secondary hypothesis is that abobotulinumtoxinA has longer duration of effect than onabotulinumtoxinA. This hypothesis will be tested with secondary efficacy endpoints, including injection cycle duration, Modified Ashworth Scale, Disability Assessment Scale and Physician Global Assessment. TRIAL REGISTRATION: EudraCT ( http://eudract.ema.europa.eu ): 2021-000161-32 and Clinicaltrials.gov ( http://clinicaltrials.gov ): NCT04936542. Overview of the study protocol by the principal investigator (MP4 185265 KB).

Application of the optimized carbon monoxide rebreathing method for the measurement of total haemoglobin mass in chronic liver disease.

BACKGROUND: Anemia is common in liver cirrhosis. This generally infers a fall in total hemoglobin mass (tHb-mass). However, hemoglobin concentration ([Hb]) may fall due to an expansion in plasma volume (PV). The "optimized carbon monoxide rebreathing method" (oCOR) measures tHb-mass directly and PV (indirectly using hematocrit). It relies upon carboxyhemoglobin (COHb) distribution throughout the entire circulation. In healthy subjects, such distribution is complete within 6-8 min. Given the altered circulatory dynamics in cirrhosis, we sought in this pilot study, to assess whether this was true in cirrhosis. The primary aim was to ascertain if the standard timings for the oCOR were applicable to patients with chronic liver disease and cirrhosis. The secondary aim was to explore the applicability of standard CO dosing methodologies to this patient population. METHODS: Sixteen patients with chronic liver parenchymal disease were studied. However, tHb-mass was determined using the standard oCOR technique before elective paracentesis. Three subjects had an inadequate COHb% rise. In the remaining 13 (11 male), mean ± standard deviation (SD) age was 52 ± 13.8 years, body mass 79.1 ± 11.4 kg, height 175 ± 6.8 cm. To these, mean ± SD dose of carbon monoxide (CO) gas administered was 0.73 ± 0.13 ml/kg COHb values at baseline, 6 and 8 min (and "7-min value") were compared to those at 10, 12, 15 and 20 min after CO rebreathing. RESULTS: The "7-min value" for median COHb% (IQR) of 6.30% (6.21%-7.47%) did not differ significantly from those at subsequent time points (8 min: 6.30% (6.21%-7.47%), 10 min: 6.33% (6.00%-7.50%), 12 min: 6.33% (5.90%-7.40%), 15 min: 6.37% (5.80%-7.33%), 20 min: 6.27% (5.70%-7.20%)). Mean difference in calculated tHb-mass between minute 7 and minute 20 was only 4.1 g, or 0.6%, p = .68. No subjects reported any adverse effects. CONCLUSIONS: The oCOR method can be safely used to measure tHb-mass in patients with chronic liver disease and ascites, without adjustment of blood sample timings. Further work might refine and validate appropriate dosing regimens.

Parallelization and optimization of genetic analyses in isolation by distance web service.

BACKGROUND: The Isolation by Distance Web Service (IBDWS) is a user-friendly web interface for analyzing patterns of isolation by distance in population genetic data. IBDWS enables researchers to perform a variety of statistical tests such as Mantel tests and reduced major axis regression (RMA), and returns vector based graphs. The more than 60 citations since 2005 confirm the popularity and utility of this website. Despite its usefulness, the data sets with over 65 populations can take hours or days to complete due to the computational intensity of the statistical tests. This is especially troublesome for web-based software analysis, since users tend to expect real-time results on the order of seconds, or at most, minutes. Moreover, as genetic data continue to increase and diversify, so does the demand for more processing power. In order to increase the speed and efficiency of IBDWS, we first determined which aspects of the code were most time consuming and whether they might be amenable to improvements by parallelization or algorithmic optimization. RESULTS: Runtime tests uncovered two areas of IBDWS that consumed significant amounts of time: randomizations within the Mantel test and the RMA calculations. We found that these sections of code could be restructured and parallelized to improve efficiency. The code was first optimized by combining two similar randomization routines, implementing a Fisher-Yates shuffling algorithm, and then parallelizing those routines. Tests of the parallelization and Fisher-Yates algorithmic improvements were performed on a variety of data sets ranging from 10 to 150 populations. All tested algorithms showed runtime reductions and a very close fit to the predicted speedups based on time-complexity calculations. In the case of 150 populations with 10,000 randomizations, data were analyzed 23 times faster. CONCLUSION: Since the implementation of the new algorithms in late 2007, datasets have continued to increase substantially in size and many exceed the largest population sizes we used in our test sets. The fact that the website has continued to work well in "real-world" tests, and receives a considerable number of new citations provides the strongest testimony to the effectiveness of our improvements. However, we soon expect the need to upgrade the number of nodes in our cluster significantly as dataset sizes continue to expand. The parallel implementation can be found at http://ibdws.sdsu.edu/.

Electroconvulsive seizure thresholds and kindling acquisition rates are altered in mouse models of human KCNQ2 and KCNQ3 mutations for benign familial neonatal convulsions.

PURPOSE: Benign familial neonatal convulsions (BFNC) is caused by mutations in the KCNQ2 and KCNQ3 genes, which encode subunits of the M-type potassium channel. The purpose of this study was to examine the effects of orthologous BFNC-causing mutations on seizure thresholds and the acquisition of corneal kindling in mice with heterozygous expression of the mutations. METHODS: The effects of the Kcnq2 gene A306T mutation and the Kcnq3 gene G311V mutation were determined for minimal clonic, minimal tonic hindlimb extension, and partial psychomotor seizures. The rate of corneal kindling acquisition was also determined for Kcnq2 A306T and Kcnq3 G311V mice. RESULTS: Seizure thresholds were significantly altered relative to wild-type animals in the minimal clonic, minimal tonic hindlimb extension, and partial psychomotor seizure models. Differences in seizure threshold were found to be dependent on the mutation expressed, the seizure testing paradigm, the genetic background strain, and the gender of the animal. Mutations in Kcnq2 and Kcnq3 were associated with an increased rate of corneal kindling. In the Kcnq2 A306T mice, an increased incidence of death occurred during and immediately following the conclusion of the kindling acquisition period. CONCLUSIONS: These results suggest that genetic alterations in the subunits that underlie the M-current and cause BFNC alter seizure susceptibility in a sex-, mouse strain-, and seizure-test dependent manner. Although the heterozygous mice do not appear to have spontaneous seizures, the increased seizure susceptibility and incidence of death during and after kindling suggests that these mutations lead to altered excitability in these animals.

Higher mortality in pediatric and adult trauma patients with traumatic coagulopathy, using age-adjusted diagnostic criteria.

BACKGROUND: Acute traumatic coagulopathy has been described in adult trauma patients. Acute traumatic coagulopathy may be associated with higher mortality and morbidity in pediatric trauma patients. We aimed to (1) compare acute traumatic coagulopathy incidence among various age groups, using age-adjusted normal reference values for three tests of coagulation, and (2) compare acute traumatic coagulopathy-associated mortality by age. METHODS: We queried our institutional trauma database for all level 1 and 2 activations with an injury severity score ≥ 9 during 2012 to 2017. Demographics, injury information, and coagulation test results were collected. Coagulopathy was defined using published age-specific and assay-specific parameters. Variables were compared among age groups (children, adults, and older adults), and logistic regression was used to determine independent associations with mortality. RESULTS: A total of 1,983 patients were included with a median injury severity score of 17 and mortality of 12%. Prolonged partial thromboplastin time, prolonged international normalized ratio, and hypofibrinogenemia were all strongly associated with mortality among adults and children, but not among older adults (P < .001, P < .001, and P > .01, respectively). Logistic regression revealed an independent association between prolonged partial thromboplastin time and mortality (P < .001). CONCLUSION: Prolonged partial thromboplastin time/international normalized ratio and hypofibrinogenemia were common among trauma patients of all ages and were associated with mortality among children and adults, but not older adults, perhaps implicating age-related hemostatic biologic differences.

Mouse models of human KCNQ2 and KCNQ3 mutations for benign familial neonatal convulsions show seizures and neuronal plasticity without synaptic reorganization.

The childhood epilepsy syndrome of benign familial neonatal convulsions (BFNC) exhibits the remarkable feature of clinical remission within a few weeks of onset and a favourable prognosis, sparing cognitive abilities despite persistent expression of the mutant KCNQ2 or KCNQ3 potassium channels throughout adulthood. To better understand such dynamic neuroprotective plasticity within the developing brain, we introduced missense mutations that underlie human BFNC into the orthologous murine Kcnq2 (Kv7.2) and Kcnq3 (Kv7.3) genes. Mutant mice were examined for altered thresholds to induced seizures, spontaneous seizure characteristics, hippocampal histology, and M-current properties of CA1 hippocampal pyramidal neurons. Adult Kcnq2(A306T/+) and Kcnq3(G311V/+) heterozygous knock-in mice exhibited reduced thresholds to electrically induced seizures compared to wild-type littermate mice. Both Kcnq2(A306T/A306T) and Kcnq3(G311V/G311V) homozygous mutant mice exhibited early onset spontaneous generalized tonic-clonic seizures concurrent with a significant reduction in amplitude and increased deactivation kinetics of the neuronal M-current. Mice had recurrent seizures into adulthood that triggered molecular plasticity including ectopic neuropeptide Y (NPY) expression in granule cells, but without hippocampal mossy fibre sprouting or neuronal loss. These novel knocking mice recapitulate proconvulsant features of the human disorder yet show that inherited M-current defects spare granule cells from reactive changes in adult hippocampal networks. The absence of seizure-induced pathology found in these epileptic mouse models parallels the benign neurodevelopmental cognitive profile exhibited by the majority of BFNC patients.