Parechovirus Genotype 3 Outbreak among Infants,New South Wales,Australia, 2013–2014

From October 2013 through February 2014, human parechovirus genotype 3 infection was identified in 183 infants in New South Wales, Australia. Of those infants, 57% were male and 95% required hospitalization. Common signs and symptoms were fever >38°C (86%), irritability (80%), tachycardia (68%), and rash (62%). Compared with affected infants in the Northern Hemisphere, infants in New South Wales were slightly older, both sexes were affected more equally, and rash occurred with considerably higher frequency. The New South Wales syndromic surveillance system, which uses near real-time emergency department and ambulance data, was useful for monitoring the outbreak. An alert distributed to clinicians reduced unnecessary hospitalization for patients with suspected sepsis.     

Distinct neural ensemble response statistics are associated with recognition and discrimination of natural sound textures

The perception of sound textures, a class of natural sounds defined by statistical sound structure such as fire, wind, and rain, has been proposed to arise through the integration of time-averaged summary statistics. Where and how the auditory system might encode these summary statistics to create internal representations of these stationary sounds, however, is unknown. Here, using natural textures and synthetic variants with reduced statistics, we show that summary statistics modulate the correlations between frequency organized neuron ensembles in the awake rabbit inferior colliculus (IC). These neural ensemble correlation statistics capture high-order sound structure and allow for accurate neural decoding in a single trial recognition task with evidence accumulation times approaching 1 s. In contrast, the average activity across the neural ensemble (neural spectrum) provides a fast (tens of milliseconds) and salient signal that contributes primarily to texture discrimination. Intriguingly, perceptual studies in human listeners reveal analogous trends: the sound spectrum is integrated quickly and serves as a salient discrimination cue while high-order sound statistics are integrated slowly and contribute substantially more toward recognition. The findings suggest statistical sound cues such as the sound spectrum and correlation structure are represented by distinct response statistics in auditory midbrain ensembles, and that these neural response statistics may have dissociable roles and time scales for the recognition and discrimination of natural sounds.

What makes a sound natural, and what are the neural codes that support recognition and discrimination of real-world natural sounds? Although it is known that the early auditory system decomposes sounds along fundamental acoustic dimensions such as intensity and frequency, the higher-level neural computations that mediate natural sound recognition are poorly understood. This general lack of understanding is in part attributed to the structural complexity of natural sounds, which is difficult to study with traditional auditory test stimuli, such as tones, noise, or modulated sequences. Such stimuli can reveal details of the neural representation for relatively low-level acoustic cues, yet they don’t capture the rich and diverse statistical structure of natural sounds. Thus, they cannot reveal many of the computations associated with higher-level sound properties that facilitate auditory tasks such as natural sound recognition or discrimination. A class of stationary natural sounds termed textures, such as the random sounds emanating from a running stream, a crowded restaurant, or a chorus of birds, have been proposed as alternative natural stimuli which allow for manipulating high-level acoustic structure (1). Texture sounds are composed of spatially and temporally distributed acoustic elements that are collectively perceived as a single source and are defined by their statistical features. Identification of these natural sounds has been proposed to be mediated through the integration of time-averaged summary statistics, which account for high-level structures such as the sparsity and time-frequency correlation structure found in many natural sounds (1–3). Using a generative model of the auditory system to measure summary statistics from natural texture sounds, it is possible to synthesize highly realistic synthetic auditory textures (1). This suggests that high-order statistical cues are perceptually salient and that the brain might extract these statistical features to build internal representations of sounds.Although neural activity throughout the auditory pathway is sensitive to a variety of statistical cues such as the sound contrast, modulation power spectrum, and correlation structure (4–12), how sound summary statistics contribute toward basic auditory tasks such as recognition and discrimination of sounds is poorly understood. Furthermore, it is unclear where along the auditory pathway summary statistics are represented and how they are reflected in neural activity. The inferior colliculus (IC) is one candidate midlevel structure for representing such summary statistics. As the principal midbrain auditory nucleus, the IC receives highly convergent brainstem inputs with varied sound selectivities. Neurons in the IC are selective over most of the perceptually relevant range of sound modulations and neural activity is strongly driven by multiple high-order sound statistics (4–7, 10). In previous work, we showed the correlation statistics of natural sounds are highly informative about stimulus identity and they appear to be represented in the correlation statistics of auditory midbrain neuron ensembles (4). Correlations between neurons have also been proposed as mechanisms for pitch identification (13) and sound localization (14). This broadly supports the hypotheses that high-order sound statistics are reflected in the response statistics of neural ensembles and that these neural response statistics could potentially subserve basic auditory tasks.Here using natural and synthetic texture sounds, we test the hypothesis that statistical structure in natural texture sounds modulates the response statistics of neural ensembles in the IC of unanesthetized rabbits, and that distinct neural response statistics have the potential to contribute toward sound recognition and discrimination behaviors. By comparing the performance of neural decoders with human texture perception, we find that place rate representation of sounds (neural spectrum) accumulates evidence about the sounds on relatively fast time scales (tens of milliseconds) exhibiting decoding trends that mirror those seen for human texture discrimination. High-order statistical sound cues, by comparison, are reflected in the correlation statistics of neural ensembles, which require substantially longer evidence accumulation times (>500 ms) and follow trends that mirror those measured for human texture recognition. Collectively, the findings suggest that spectrum cues and accompanying place rate representation (neural spectrum) may contribute surprisingly little toward the recognition of auditory textures. Instead, high-order statistical sound structure is reflected in the distributed patterns of correlated activity across IC neural ensembles and such neural response structure has the potential to contribute toward the recognition of natural auditory textures.     

Pretransplant hepatitis C virus infection and its effect on the post-transplant course of living renal allograft recipients

BACKGROUND: Hepatitis C virus infection (HCV) is a main health problem in end-stage renal disease (ESRD) patients. The effect of pretransplant HCV infection on survival among ESRD patients who have undergone renal transplantation is controversial. We report the results of a large monocenter study that evaluated the effect of hepatitis C on the patient, and on graft survival in renal-transplanted patients who received living donated allograft. METHODS: A historical cohort study, we investigated all 1006 patients who received a living kidney transplant at Baghiatollah Medical Center in Tehran, Iran, between March 1995 and October 2001 (up to 85 months follow up). Patients' sera had been routinely assayed for anti-HCV antibodies and hepatitis B surface antigen (HBsAg) at the time of transplantation. The HBsAg-positive patients were excluded from the survival analysis. Survivals were examined using Kaplan-Meier analysis and compared using the log-rank test. Multivariate analysis was performed using Cox's model. RESULTS: Forty-five patients (4.5%) were anti-HCV-antibody positive. Anti-HCV-antibody-positive patients spent a longer time on dialysis and had a higher rate of retransplantation. There were no differences in recipients' sex and age and donors' age between the two groups. The 7-year patient survival rate was 89.9% in the anti-HCV-antibody-positive group and 95.5% in the HCV-negative group (P = 0.74). Seven-year graft survival was 82.0% and 75.0% in the anti-HCV-antibody-positive and HCV-negative groups, respectively (P = 0.39). In the multivariate analysis, age was the only significant parameter correlated with patient survival (P = 0.02). CONCLUSIONS: HCV infection does not seem to influence patient and graft survival within a medium-time follow up in living allograft recipients, and anti-HCV-antibody positive status (alone) is not a contraindication for renal transplantation. However, further studies are needed to better define the role of HCV infection in long-term prognosis.     

Hb Dhonburi (Neapolis) [beta126(H4)Val-->Gly] identified in a family from northern Iran

Thalassemias are the most common hereditary diseases in Iran, resulting from synthesis defects in one or more hemoglobin (Hb) subunits. The majority of patients suffer from beta-thalassemia (thal), but cases with microcytic hypochromic anemia and normal electrophoretic patterns are suspected to have alpha- or silent beta-thal. A family from the northern part of Iran, an area highly prevalent for thalassemias, was referred to us for prenatal diagnosis. The hematological data of the father indicated a pattern of beta-thal minor. Reverse hybridization analysis for the most common beta-globin mutations identified IVS-II-1 (G-->A) in the heterozygous state. The maternal laboratory data indicated a case more compatible with alpha-thal. Iron deficient anemia was ruled out, and common alpha-thal point mutations and deletions were investigated. As no mutation was detected, chain synthesis was performed and showed an alpha/beta chain ratio of 2.1, that was in the range of beta-thal minor. DNA sequencing of the entire beta-globin gene identified a heterozygous GTG-->GGG (Val-->Gly) mutation at codon 126, also known as Hb Dhonburi (Neapolis). Prenatal diagnosis of the fetal DNA showed the absence of the IVS-II-1 and codon 126 anomalies. This result demonstrates the importance of screening of individuals with mild microcytic hypochromic anemia for both alpha- and silent beta-thal mutations.     

Minimally invasive insertion of an equine stented pulmonary valve with a built-in sinus portion in a sheep model

Objectives : This study evaluated the feasibility of inserting a new equine stented‐valve with a sinus portion in a lamb survival model, through a minimally invasive thoracotomy with right ventricular access without cardiopulmonary bypass. Background : Extant surgical or percutaneous methods for inserting biological valves in the right outflow tract have drawbacks and limitations. Methods : A decellularized equine valved jugular vein, sutured to a self‐expanding stent with a sinus portion, was placed through a minimal right thoracotomy using a newly developed flexible hydraulic release device in seven lambs. The approach through the right ventricle into the pulmonary valve position is achieved on a beating heart. Results : The stented valves were correctly positioned in the right outflow tract, were competent up to 6 months as confirmed by angiography and echocardiography, and were well‐tolerated by the animals, with endothelialization of the valve demonstrated at 6 months. Conclusions : The newly developed hydraulic release system allowed for safe and reliable insertion of an equine stented‐valve with a sinus portion, through a right transventricular approach on a beating heart, in a sheep survival model. © 2011 Wiley Periodicals, Inc.     

Hospital-acquired infections in a tertiary hospital in Iran before and during the COVID-19 pandemic

Wiener Medizinische Wochenschrift - Infection prevention protocols are the accepted standard to control nosocomial infections. These protective measures intensified after the coronavirus 2019...     

Predominant endothelial vasomotor activity during human sleep: a near‐infrared spectroscopy study

Vasomotion is important in the study of vascular disorders, including stroke. Spontaneous low and very low hemodynamic oscillations (3–150 mHz) measured with near‐infrared spectroscopy (NIRS) reflect the endothelial (3–20 mHz), neurogenic (20–40 mHz) and myogenic (40–150 mHz) components of vasomotion. We investigated sleep‐specific patterns of vasomotion by characterizing hemodynamic oscillations with NIRS in healthy subjects, and tested the feasibility of NIRS as a bedside tool for monitoring vasomotion during whole‐night sleep. To characterize local cerebral vasomotion, we compared cerebral NIRS measurements with muscular NIRS measurements and peripheral arterial oxygen saturation (SpO₂) during different sleep stages in 14 healthy volunteers. Spectral powers of hemodynamic oscillations in the frequency range of endothelial vasomotion were systemically predominant in every sleep stage, and the powers of endothelial and neurogenic vasomotion decreased in deep sleep as compared with light sleep and rapid eye movement (REM) sleep in brain, muscle, and SpO₂. The decrease in the powers of myogenic vasomotion in deep sleep only occurred in brain, and not in muscle. These results point to a predominant role of endothelial function in regulating vasomotion during sleep. The decline in cerebral endothelial and neurogenic vasomotion during progression to deeper non‐REM sleep suggests that deep sleep may play a protective role for vascular function. NIRS can be used to monitor endothelial control of vasomotion during nocturnal sleep, thus providing a promising non‐invasive bedside tool with which to study the sleep‐relevant pathological mechanisms in vascular diseases and stroke.