Total orthotopic small bowel transplantation in swine under FK 506

Previous experimental studies in rodents and in dogs have established the efficacy of FK 506 in controlling the immunologic events following small bowel or multivisceral transplantation.1–5 To complete the assessment of FK 506 in experimental small bowel transplantation, we present here our experience with the frequently used swine model

Migraine and cluster headache show impaired neurosteroids patterns

Background: Perturbation of neuronal excitability contributes to migraine. Neurosteroids modulate the activity of γ-aminobutyric acid A and N-methyl-d-aspartate receptors, and might be involved in the pathogenesis of migraine. Here, we measured plasma levels of four neurosteroids, i.e., allopregnanolone, epiallopregnanolone, dehydroepiandrosterone and deydroepiandrosterone sulfate, in patients affected by episodic migraine, chronic migraine, or cluster headache. Methods: Nineteen female patients affected by episodic migraine, 51 female patients affected by chronic migraine, and 18 male patients affected by cluster headache were recruited to the study. Sex- and age-matched healthy control subjects (31 females and 16 males) were also recruited. Patients were clinically characterized by using validated questionnaires. Plasma neurosteroid levels were measured by liquid chromatography-tandem mass spectrometry. Results: We found disease-specific changes in neurosteroid levels in our study groups. For example, allopregnanolone levels were significantly increased in episodic migraine and chronic migraine patients than in control subjects, whereas they were reduced in patients affected by cluster headache. Dehydroepiandrosterone and dehydroepiandrosterone sulfate levels were reduced in patients affected by chronic migraine, but did not change in patients affected by cluster headache. Conclusion: We have shown for the first time that large and disease-specific changes in circulating neurosteroid levels are associated with chronic headache disorders, raising the interesting possibility that fluctuations of neurosteroids at their site of action might shape the natural course of migraine and cluster headache. Whether the observed changes in neurosteroids are genetically determined or rather result from exposure to environmental or intrinsic stressors is unknown. This might also be matter for further investigation because stress is a known triggering factor for headache attacks in both migraineurs and cluster headache patients

Perception of Nigerian Dùndún talking drum performances as speech-like vs. music-like: The role of familiarity and acoustic cues

It seems trivial to identify sound sequences as music or speech, particularly when the sequences come from different sound sources, such as an orchestra and a human voice. Can we also easily distinguish these categories when the sequence comes from the same sound source? On the basis of which acoustic features? We investigated these questions by examining listeners’ classification of sound sequences performed by an instrument intertwining both speech and music: the dùndún talking drum. The dùndún is commonly used in south-west Nigeria as a musical instrument but is also perfectly fit for linguistic usage in what has been described as speech surrogates in Africa. One hundred seven participants from diverse geographical locations (15 different mother tongues represented) took part in an online experiment. Fifty-one participants reported being familiar with the dùndún talking drum, 55% of those being speakers of Yorùbá. During the experiment, participants listened to 30 dùndún samples of about 7s long, performed either as music or Yorùbá speech surrogate (n = 15 each) by a professional musician, and were asked to classify each sample as music or speech-like. The classification task revealed the ability of the listeners to identify the samples as intended by the performer, particularly when they were familiar with the dùndún, though even unfamiliar participants performed above chance. A logistic regression predicting participants’ classification of the samples from several acoustic features confirmed the perceptual relevance of intensity, pitch, timbre, and timing measures and their interaction with listener familiarity. In all, this study provides empirical evidence supporting the discriminating role of acoustic features and the modulatory role of familiarity in teasing apart speech and music

The Dùndún Drum helps us understand how we process speech and music

Every day, you hear many sounds in your environment, like speech, music, animal calls, or passing cars. How do you tease apart these unique categories of sounds? We aimed to understand more about how people distinguish speech and music by using an instrument that can both “speak” and play music: the dùndún talking drum. We were interested in whether people could tell if the sound produced by the drum was speech or music. People who were familiar with the dùndún were good at the task, but so were those who had never heard the dùndún, suggesting that there are general characteristics of sound that define speech and music categories. We observed that music is faster, more regular, and more variable in volume than “speech.” This research helps us understand the interesting instrument that is dùndún and provides insights about how humans distinguish two important types of sound: speech and music

Poly (ethyl 2-cyanoacrylate) nanoparticles (PECA-NPs) as possible agents in tumor treatment

Tumor eradication has many challenges due to the difficulty of selectively delivering anticancer drugs to malignant cells avoiding contact with healthy tissues/organs. The improvement of antitumor efficacy and the reduction of systemic side effects can be achieved using drug loaded nanoparticles. In this study, poly (ethyl 2-cyanoacrylate) nanoparticles (PECA-NPs) were prepared using an emulsion polymerization method and their potential for cancer treatment was investigated. The size, polydispersity index and zeta potential of prepared nanoparticles are about 80 nm, 0.08 and −39.7 mV, respectively. The stability test shows that the formulation is stable for 15 days, while an increase in particle size occurs after 30 days. TEM reveals the spherical morphology of nanoparticles; furthermore, FTIR and 1 H NMR analyses confirm the structure of PECA-NPs and the complete polymerization. The nanoparticles demonstrate an in vitro concentration-dependent cytotoxicity against human epithelial colorectal adenocarcinoma cell lines (Caco-2), as assessed by MTT assay. The anticancer activity of PECA-NPs was studied on 3D tumor spheroids models of hepatocellular carcinoma (HepG2) and kidney adenocarcinoma cells (A498) to better understand how the nanoparticles could interact with a complex structure such as a tumor. The results confirm the antitumor activity of PECA-NPs. Therefore, these systems can be considered good candidates in tumor treatment

One step minilaparotomy-assisted transmesenteric portal vein recanalization combined with transjugular intrahepatic portosystemic shunt placement: A novel surgical proposal in pediatrics

Transjugular intrahepatic portosystemic shunt (TIPS) placement is a standard procedure for the treatment of portal hypertension complications. When this conventional approach is not feasible, alternative procedures for systemic diversion of portal blood have been proposed. A one-step interventional approach, combining minilaparotomy-assisted transmesenteric (MAT) antegrade portal recanalization and TIPS, is described in an adolescent with recurrent esophageal varice bleeding and portal cavernoma (PC). A 16-year-old girl was admitted to our Unit because of repeated bleeding episodes over a short period of time due to esophageal varices in the context of a PC. A portal vein recanalization through an ileocolic vein isolation with the MAT approach followed by TIPS during the same session was performed. In the case of failed portal recanalization, this approach, would also be useful for varice endovascular embolization. Postoperative recovery was uneventful. Treatment consisting of propanolol, enoxaparin and a proton pump inhibitor was prescribed after the procedure. One month post-op, contrast enhanced computed tomography confirmed the patency of the portal and intrahepatic stent grafts. No residual peritoneal fluid was detected nor opacification of the large varices. Endoscopy showed good improvement of the varices. Doppler ultrasound confirmed the accelerated flow in the portal stent and hepatopetal flow inside the intrahepatic portal branches. Three months post-op, TIPS maintained its hourglass shape despite a slight expansion. Portal hypertension and life threatening conditions related to PC would benefit from one-step portal recanalization. MAT-TIPS is feasible and safe for the treatment of PC even in children. This minimally invasive procedure avoids or delays surgical treatment or re-transplantation when necessary in pediatric patients

Gibbs sampling with people

A core problem in cognitive science and machine learning is to understand how humans derive semantic representations from perceptual objects, such as color from an apple, pleasantness from a musical chord, or seriousness from a face. Markov Chain Monte Carlo with People (MCMCP) is a prominent method for studying such representations, in which participants are presented with binary choice trials constructed such that the decisions follow a Markov Chain Monte Carlo acceptance rule. However, while MCMCP has strong asymptotic properties, its binary choice paradigm generates relatively little information per trial, and its local proposal function makes it slow to explore the parameter space and find the modes of the distribution. Here we therefore generalize MCMCP to a continuous-sampling paradigm, where in each iteration the participant uses a slider to continuously manipulate a single stimulus dimension to optimize a given criterion such as 'pleasantness'. We formulate both methods from a utility-theory perspective, and show that the new method can be interpreted as 'Gibbs Sampling with People' (GSP). Further, we introduce an aggregation parameter to the transition step, and show that this parameter can be manipulated to flexibly shift between Gibbs sampling and deterministic optimization. In an initial study, we show GSP clearly outperforming MCMCP; we then show that GSP provides novel and interpretable results in three other domains, namely musical chords, vocal emotions, and faces. We validate these results through large-scale perceptual rating experiments. The final experiments use GSP to navigate the latent space of a state-of-the-art image synthesis network (StyleGAN), a promising approach for applying GSP to high-dimensional perceptual spaces. We conclude by discussing future cognitive applications and ethical implications

Heart rate detection by Fitbit ChargeHR™: A validation study versus portable polysomnography

Consumer "Smartbands" can collect physiological parameters, such as heart rate (HR), continuously across the sleep-wake cycle. Nevertheless, the quality of HR data detected by such devices and their place in the research and clinical field is debatable, as they are rarely rigorously validated. The objective of the present study was to investigate the reliability of pulse photoplethysmographic detection by the Fitbit ChargeHR (FBCHR, Fitbit Inc.) in a natural setting of continuous recording across vigilance states. To fulfil this aim, concurrent portable polysomnographic (pPSG) and the Fitbit's photoplethysmographic data were collected from a group of 25 healthy young adults, for ≥12hr. The pPSG-derived HR was automatically computed and visually verified for each 1-min epoch, while the FBCHR HR measurements were downloaded from the application programming interface provided by the manufacturer. The FBCHR was generally accurate in estimating the HR, with a mean (SD) difference of -0.66(0.04)beats/min (bpm) versus the pPSG-derived HR reference, and an overall Pearson's correlation coefficient (r) of 0.93 (average per participant r=0.85±0.11), regardless of vigilance state. The correlation coefficients were larger during all sleep phases (rapid eye movement, r=0.9662; N1, r=0.9918; N2, r=0.9793; N3, r=0.9849) than in wakefulness (r=0.8432). Moreover, the correlation coefficient was lower for HRs of >100bpm (r=0.374) than for HRs of <100bpm (r=0.84). Consistently, Bland-Altman analysis supports the overall higher accuracy in the detection of HR during sleep. The relatively high accuracy of FBCHR pulse rate detection during sleep makes this device suitable for sleep-related research applications in healthy participants, under free-living conditions

Gibbs sampling with people

A core problem in cognitive science and machine learning is to understand how humans derive semantic representations from perceptual objects, such as color from an apple, pleasantness from a musical chord, or seriousness from a face. Markov Chain Monte Carlo with People (MCMCP) is a prominent method for studying such representations, in which participants are presented with binary choice trials constructed such that the decisions follow a Markov Chain Monte Carlo acceptance rule. However, while MCMCP has strong asymptotic properties, its binary choice paradigm generates relatively little information per trial, and its local proposal function makes it slow to explore the parameter space and find the modes of the distribution. Here we therefore generalize MCMCP to a continuous-sampling paradigm, where in each iteration the participant uses a slider to continuously manipulate a single stimulus dimension to optimize a given criterion such as 'pleasantness'. We formulate both methods from a utility-theory perspective, and show that the new method can be interpreted as 'Gibbs Sampling with People' (GSP). Further, we introduce an aggregation parameter to the transition step, and show that this parameter can be manipulated to flexibly shift between Gibbs sampling and deterministic optimization. In an initial study, we show GSP clearly outperforming MCMCP; we then show that GSP provides novel and interpretable results in three other domains, namely musical chords, vocal emotions, and faces. We validate these results through large-scale perceptual rating experiments. The final experiments use GSP to navigate the latent space of a state-of-the-art image synthesis network (StyleGAN), a promising approach for applying GSP to high-dimensional perceptual spaces. We conclude by discussing future cognitive applications and ethical implications