Intrarenal Resistance Index as a Prognostic Parameter in Patients with Liver Cirrhosis Compared with Other Hepatic Scoring Systems

Background and Aims: Patients with advanced liver cirrhosis who develop renal dysfunction have a poor prognosis. Elevated intrarenal resistance indices (RIs) due to renal vascular constriction have been described before in cirrhotic patients. In the current study, we prospectively investigated the course of intrarenal RIs and compared their prognostic impact with those of the Model for End-Stage Liver Disease (MELD) and the Child-Pugh scores. Methods: Sixty-three patients with liver cirrhosis underwent a baseline visit which included a sonographic examination and laboratory tests. Forty-four patients were prospectively monitored. The end points were death or survival at the day of the follow-up visit. Results: In 28 patients, a follow-up visit was performed after 22 8 months (group 1). Sixteen patients died during follow-up after 12 8 months (group 2). Group 2 patients showed a significantly higher baseline RI (0.76 +/- 0.05) than group 1 patients (RI = 0.72 +/- 0.06; p < 0.05). As shown by receiver operating characteristic analysis, the RI and the MELD score achieved similar sensitivity and specificity {[}area under the curve (AUC): 0.722; 95% confidence interval (95% CI): 0.575-0.873 vs. AUC: 0.724; 95% CI: 0.575-0.873, z = 0.029, n.s.] in predicting survival and were superior to the Child-Pugh score (AUC: 0.677; 96% Cl: 0.518-0.837). Conclusion: The RI is not inferior in sensitivity and specificity to the MELD score. Cirrhotic patients with elevated RIs have impaired short- and long-term survival. The RI may help identify high-risk patients that require special therapeutic care. Copyright (C) 2012 S. Karger AG, Base

732-6 Resection of Aortic Coarctation and Modified Extended Anastomosis of Descending Aorta to Undersurface of Aortic Arch: Effect on Recurrence

Recurrent aortic coarctation is a frequent complication requiring reintervention following surgical repair of coarctation of the aorta (COA) in infants and neonates. Recoarctation is most commonly seen within the first year of life and is reported to be as high as 30%. Inadequate removal of ductal tissue, failure of growth in the primary anastomosis, and tension on the suture line have been cited as important factors using standard techniques of resection and end to end anastomosis (RETE) and subclavian flap arterioplasty (SFA). To address these issues, we have employed a technique of coarctation resection and modified extended anastomosis of the descending aorta to the undersurface of the aortic arch (RMEDA) since 1992. The salient features of this technique include extensive mobilization of the aortic arch and neck vessels, resection of the coarctation, careful trimming of all ductal tissue, and ligation of the isthmus just beyond the left subclavian artery (LSCA) allowing the distal arch to serve as an end vessel to the LSCA, and end to side anastomosis of the descending aorta to a separate incision in the undersurface of the proximal aortic arch. Fourteen neonates (median age = 12.5 days) and 5 infants (median age = 62 days) with a mean peak systolic gradient of 33±13 torr across the coarctation segment, underwent RMEDA repair of discrete COA and tubular hypolasia of the arch. Two of these infants had recurrent COA following an initial operation performed elsewhere in the neonatal period. Other procedures performed at the time repair of COA include PDA ligation (14), pulmonary artery banding (3), VSD closure (3), and ASD closure (2). Mean (±SD) aortic cross-clamp time was 19 (±6) minutes and mean intraoperative post-repair peak systolic gradient measured 2.3 (±4.7) torr. Early postoperative complications included a recurrent laryngeal nerve injury and a transient focal tonic clonic seizure. There was one early death from a subsequent surgical procedure. Eighteen late survivors at median follow-up of 12 months (range 3 to 24 monts) were free of recurrent COA by echocardiography and clinical examination and required no catheter or surgical reinterventions. In summary, the technique described herein eliminates the ductal tissue from the anastomotic site, and circumvents distal arch hypoplasia. In our experience, there has been no recurrence at midterm followup; however, further evaluation is needed to ascertain its efficacy in preventing late recurrence of coarctation

The VITAH Trial Vitamin D supplementation and cardiac autonomic tone in hemodialysis: a blinded, randomized controlled trial

BACKGROUND: Patients with end-stage kidney disease (ESKD) have a high rate of mortality and specifically an increased risk of sudden cardiac death (SCD). Impaired cardiac autonomic tone is associated with elevated risk of SCD. Moreover, patients with ESKD are often vitamin D deficient, which we have shown may be linked to autonomic dysfunction in humans. To date, it is not known whether vitamin D supplementation normalizes cardiac autonomic function in the high-risk ESKD population. The VITamin D supplementation and cardiac Autonomic tone in Hemodialysis (VITAH) randomized trial will determine whether intensive vitamin D supplementation therapies improve cardiac autonomic tone to a greater extent than conventional vitamin D supplementation regimens in ESKD patients requiring chronic hemodialysis. METHODS/DESIGN: A total of 60 subjects with ESKD requiring thrice weekly chronic hemodialysis will be enrolled in this 2x2 crossover, blinded, randomized controlled trial. Following a 4-week washout period from any prior vitamin D therapy, subjects are randomized 1:1 to intensive versus standard vitamin D therapy for 6 weeks, followed by a 12-week washout period, and finally the remaining treatment arm for 6 weeks. Intensive vitamin D treatment includes alfacalcidiol (activated vitamin D) 0.25mcg orally with each dialysis session combined with ergocalciferol (nutritional vitamin D) 50 000 IU orally once per week and placebo the remaining two dialysis days for 6 weeks. The standard vitamin D treatment includes alfacalcidiol 0.25mcg orally combined with placebo each dialysis session per week for 6 weeks. Cardiac autonomic tone is measured via 24 h Holter monitor assessments on the first dialysis day of the week every 6 weeks throughout the study period. The primary outcome is change in the low frequency: high frequency heart rate variability (HRV) ratio during the first 12 h of the Holter recording at 6 weeks versus baseline. Secondary outcomes include additional measures of HRV. The safety of intensive versus conventional vitamin D supplementation is also assessed. DISCUSSION: VITAH will determine whether an intensive vitamin D supplementation regimen will improve cardiac autonomic tone compared to conventional vitamin D supplementation and will assess the safety of these two supplementation regimens in ESKD patients receiving chronic hemodialysis. TRIAL REGISTRATION: ClinicalTrials.gov, NCT0177481

Cognitive demands of face monitoring: Evidence for visuospatial overload

Young children perform difficult communication tasks better face to face than when they cannot see one another (e.g., Doherty-Sneddon & Kent, 1996). However, in recent studies, it was found that children aged 6 and 10 years, describing abstract shapes, showed evidence of face-to-face interference rather than facilitation. For some communication tasks, access to visual signals (such as facial expression and eye gaze) may hinder rather than help children’s communication. In new research we have pursued this interference effect. Five studies are described with adults and 10- and 6-year-old participants. It was found that looking at a face interfered with children’s abilities to listen to descriptions of abstract shapes. Children also performed visuospatial memory tasks worse when they looked at someone’s face prior to responding than when they looked at a visuospatial pattern or at the floor. It was concluded that performance on certain tasks was hindered by monitoring another person’s face. It is suggested that processing of visual communication signals shares certain processing resources with the processing of other visuospatial information

Reasons for and consequences of missed appointments in general practice in the UK: questionnaire survey and prospective review of medical records

Background Missed appointments are a common occurrence in primary care in the UK, yet little is known about the reasons for them, or the consequences of missing an appointment. This paper aims to determine the reasons for missed appointments and whether patients who miss an appointment subsequently consult their general practitioner (GP). Secondary aims are to compare psychological morbidity, and the previous appointments with GPs between subjects and a comparison group. Methods Postal questionnaire survey and prospective medical notes review of adult patients missing an appointment and the comparison group who attended appointments over a three week period in seven general practices in West Yorkshire. Results Of the 386 who missed appointments 122 (32%) responded. Of the 386 in the comparison group 223 (58%) responded, resulting in 23 case-control matched pairs with complete data collection. Over 40% of individuals who missed an appointment and participated said that they forgot the appointment and a quarter said that they tried very hard to cancel the appointment or that it was at an inconvenient time. A fifth reported family commitments or being too ill to attend. Over 90% of the patients who missed an appointment subsequently consulted within three months and of these nearly 60% consulted for the stated problem that was going to be presented in the missed consultation. The odds of missing an appointment decreased with increasing age and were greater among those who had missed at least one appointment in the previous 12 months. However, estimates for comparisons between those who missed appointments and the comparison group were imprecise due to the low response rate. Conclusion Patients who miss appointments tend to cite practice factors and their own forgetfulness as the main reasons for doing so, and most attend within three months of a missed appointment. This study highlights a number of implications for future research. More work needs to be done to engage people who miss appointments into research in a meaningful way

Optical absorption in boron clusters B6_{6} and B6+_{6}^{+} : A first principles configuration interaction approach

The linear optical absorption spectra in neutral boron cluster B$_{6}$ and cationic B$_{6}^{+}$ are calculated using a first principles correlated electron approach. The geometries of several low-lying isomers of these clusters were optimized at the coupled-cluster singles doubles (CCSD) level of theory. With these optimized ground-state geometries, excited states of different isomers were computed using the singles configuration-interaction (SCI) approach. The many body wavefunctions of various excited states have been analysed and the nature of optical excitation involved are found to be of collective, plasmonic type.Comment: 22 pages, 38 figures. An invited article submitted to European Physical Journal D. This work was presented in the International Symposium on Small Particles and Inorganic Clusters - XVI, held in Leuven, Belgiu

Tau isoform-specific enhancement of L-type calcium current and augmentation of afterhyperpolarization in rat hippocampal neurons

Accumulation of tau is observed in dementia, with human tau displaying 6 isoforms grouped by whether they display either 3 or 4 C-terminal repeat domains (3R or 4R) and exhibit no (0N), one (1N) or two (2N) N terminal repeats. Overexpression of 4R0N-tau in rat hippocampal slices enhanced the L-type calcium (Ca(2+)) current-dependent components of the medium and slow afterhyperpolarizations (AHPs). Overexpression of both 4R0N-tau and 4R2N-tau augmented Ca(V)1.2-mediated L-type currents when expressed in tsA-201 cells, an effect not observed with the third 4R isoform, 4R1N-tau. Current enhancement was only observed when the pore-forming subunit was co-expressed with Ca(V)β3 and not Ca(V)β2a subunits. Non-stationary noise analysis indicated that enhanced Ca(2+) channel current arose from a larger number of functional channels. 4R0N-tau and Ca(V)β3 were found to be physically associated by co-immunoprecipitation. In contrast, the 4R1N-tau isoform that did not augment expressed macroscopic L-type Ca(2+) current exhibited greatly reduced binding to Ca(V)β3. These data suggest that physical association between tau and the Ca(V)β3 subunit stabilises functional L-type channels in the membrane, increasing channel number and Ca(2+) influx. Enhancing the Ca(2+)-dependent component of AHPs would produce cognitive impairment that underlie those seen in the early phases of tauopathies

The Unusual Infrared Object HDF-N J123656.3+621322

We describe an object in the Hubble Deep Field North with very unusual near-infrared properties. It is readily visible in Hubble Space Telescope NICMOS images at 1.6um and from the ground at 2.2um, but is undetected (with signal-to-noise <~ 2) in very deep WFPC2 and NICMOS data from 0.3 to 1.1um. The f_nu flux density drops by a factor >~ 8.3 (97.7% confidence) from 1.6 to 1.1um. The object is compact but may be slightly resolved in the NICMOS 1.6um image. In a low-resolution, near-infrared spectrogram, we find a possible emission line at 1.643um, but a reobservation at higher spectral resolution failed to confirm the line, leaving its reality in doubt. We consider various hypotheses for the nature of this object. Its colors are unlike those of known galactic stars, except perhaps the most extreme carbon stars or Mira variables with thick circumstellar dust shells. It does not appear to be possible to explain its spectral energy distribution as that of a normal galaxy at any redshift without additional opacity from either dust or intergalactic neutral hydrogen. The colors can be matched by those of a dusty galaxy at z >~ 2, by a maximally old elliptical galaxy at z >~ 3 (perhaps with some additional reddening), or by an object at z >~ 10 whose optical and 1.1um light have been suppressed by the intergalactic medium. Under the latter hypothesis, if the luminosity results from stars and not an AGN, the object would resemble a classical, unobscured protogalaxy, with a star formation rate >~ 100 M_sun/yr. Such UV-bright objects are evidently rare at 2 < z < 12.5, however, with a space density several hundred times lower than that of present-day L* galaxies.Comment: Accepted for publication in the Astrophysical Journal. 27 pages, LaTeX, with 7 figures (8 files); citations & references updated + minor format change

Deep Learning Criminal Networks

Recent advances in deep learning methods have enabled researchers to develop and apply algorithms for the analysis and modeling of complex networks. These advances have sparked a surge of interest at the interface between network science and machine learning. Despite this, the use of machine learning methods to investigate criminal networks remains surprisingly scarce. Here, we explore the potential of graph convolutional networks to learn patterns among networked criminals and to predict various properties of criminal networks. Using empirical data from political corruption, criminal police intelligence, and criminal financial networks, we develop a series of deep learning models based on the GraphSAGE framework that are capable to recover missing criminal partnerships, distinguish among types of associations, predict the amount of money exchanged among criminal agents, and even anticipate partnerships and recidivism of criminals during the growth dynamics of corruption networks, all with impressive accuracy. Our deep learning models significantly outperform previous shallow learning approaches and produce high-quality embeddings for node and edge properties. Moreover, these models inherit all the advantages of the GraphSAGE framework, including the generalization to unseen nodes and scaling up to large graph structures.Comment: 14 two-column pages, 5 figure