Dysregulation of threat neurocircuitry during fear extinction: the role of anhedonia

Dimensional models of anxiety and depression highlight common and distinct symptom clusters that are thought to reflect disruptions in underlying functional processes. The current study investigated how functioning of threat neurocircuitry relates to symptom dimensions of anxiety and depression. Participants were aged 18–19 years (n = 229, 158 female) and were selected to ensure a range of scores on symptom measures. Symptom dimensions of “General Distress” (common to anxiety disorders and depression), “Fears” (more specific to anxiety disorders), and “Anhedonia-apprehension” (more specific to depression) were evaluated. Participants underwent functional magnetic resonance imaging during a Pavlovian fear conditioning paradigm. Multilevel modeling analyses estimated relationships between symptom dimensions and activation in threat neural circuitry. Exploratory whole brain analyses were also conducted. Threat-related neural activity was not associated with General Distress or Fears. Anhedonia-apprehension was associated with activation of bilateral amygdala, anterior insula and dACC during late extinction. We found no evidence to support an association between symptom dimensions of General Distress or Fears with threat circuitry activation in a large sample of young adults. We did, however, find that the symptom dimension of Anhedonia-apprehension was significantly associated with threat-related neural activation during fear extinction. This effect requires replication in future work but may reflect anhedonic impairments in learning when contingencies are altered, possibly linked to the rewarding relief of an unexpectedly absent threat.Subject terms: Emotion, Limbic system     

Serum GFAP levels in optic neuropathies

ObjectiveExperimental studies have indicated that adipocytokines are associated with vascular diseases with regard to the pathology of atherosclerotic plaque. We hypothesized that the strength of the associations between adipocytokines and stroke would differ between ischemic stroke subtypes.MethodsA total of 96 acute ischemic stroke patients (within 5 days from onset) and 48 non-stroke subjects were analyzed in this study. Stroke patients were comprised of 26 strokes due to large artery atherosclerosis (LAA) and 72 non-LAA strokes. Venous blood from all participants was drawn after an overnight fast, and serum levels of leptin, adiponectin and resistin were measured by multiple sandwich immunoassay techniques.ResultsCompared with non-LAA strokes, patients with LAA strokes had lower levels of serum adiponectin (6.4 ± 3.1 vs. 8.5 ± 3.9 μg/mL; P = 0.04), and a higher level of leptin-to-adiponectin ratio (L:A ratio; 1.6 ± 1.4 vs. 0.9 ± 0.9; P < 0.01). Multinomial logistic regression analyses showed that, although none of the adipocytokines was associated with non-LAA strokes, lower adiponectin (adjusted OR, 0.79 per 1-μg/mL increase; 95% CI, 0.64–0.98), higher leptin (aOR, 1.12 per 1-ng/mL increase; 95% CI, 1.004–1.25) and higher L:A ratio (aOR, 2.93 per 1-quartile increase; 95% CI, 1.39–6.15) showed significant associations with increased odds of having LAA stroke, compared to non-stroke subjects.ConclusionFrom our study, we documented that leptin and adiponectin had differential association patterns with ischemic stroke according to the stroke subtype. Careful consideration of the heterogeneity of stroke subtypes would be warranted in studying the utility of biomarkers including adipocytokines.     

Transient hyperglycaemia – an underestimated problem of paediatric oncohaematology

Introduction

The majority of hyperglycaemic incidents in oncohaematological patients treated with glucocorticosteroids remain undiagnosed. The aim of our study was to work out a detailed protocol for the control of carbohydrate metabolism and to evaluate whether such a protocol can help in diagnosis of carbohydrate metabolism disturbances in oncohaematological paediatric patients.

Material and methods

A one hundred and twenty-eight children treated for proliferative diseases of the haematopoietic system and severe aplastic anaemia with therapeutic protocols including glucocorticosteroids were divided into two groups. Group I consisted of 70 children, whose blood glucose was evaluated on random occasions (retrospective analysis). Group II consisted of 58 children included in the programme of intensive carbohydrate metabolism control (prospective analysis). We compared the incidence of hyperglycaemia in both groups as well as the number of hyperglycaemic incidents per individual therapeutic protocol.

Results

A significantly higher incidence of transient hyperglycaemia was noted in oncohaematological patients in the programme of early carbohydrate metabolism disturbances diagnosis than in the other group (22.4% vs. 5.7% respectively; p = 0.008), especially in patients treated with the ALL IC-BFM 2002 protocol for the high risk group (arm A and B), the ALL-REZ BFM 2002 protocol, and in a heterogenous group of children (protocols ALCL 99, Euro-LB02, Interfant-06, WPSAA) (p = 0.042, 0.021 and 0.002, respectively).

Conclusions

The improvement of transient hyperglycaemia detection may constitute the first step towards the reduction of unfavourable consequences of hyperglycaemia. Prospective studies are required to demonstrate the influence of normal carbohydrate metabolism on the frequency of infectious complications in this group.     

Cognitive subtypes of dyslexia

Different theories conceptualise dyslexia as either a phonological, attentional, auditory, magnocellular, or automatisation deficit. Such heterogeneity suggests the existence of yet unrecognised subtypes of dyslexics suffering from distinguishable deficits. The purpose of the study was to identify cognitive subtypes of dyslexia. Out of 642 children screened for reading ability 49 dyslexics and 48 controls were tested for phonological awareness, auditory discrimination, motion detection, visual attention, and rhythm imitation. A combined cluster and discriminant analysis approach revealed three clusters of dyslexics with different cognitive deficits. Compared to reading-unimpaired children cluster no. 1 had worse phonological awareness; cluster no. 2 had higher attentional costs; cluster no. 3 performed worse in the phonological, auditory, and magnocellular tasks. These results indicate that dyslexia may result from distinct cognitive impairments. As a consequence, prevention and remediation programmes should be specifically targeted for the individual child's deficit pattern.     

The effect of cyanobacterial blooms in the Siemianówka Dam Reservoir on the phytoplankton structure in the Narew River

The effect of cyanobacterial blooms on the phytoplankton structure in the lowland Narew River (north-eastern Poland) was examined. The studies were carried out at stations situated at different distances from the eutrophic Siemianówka Dam Reservoir. In 2008, the investigated lowland reservoir and the outflowing river were characterized by the dominance of toxic cyanobacteria (from July to October). At a station situated 130 km below the dam, species composition in the river was very similar to that in the shallow reservoir. Planktothrix agardhii was the main and permanent dominant, both in limnoplankton and potamoplankton. The current study indicates that the eutrophic Siemianówka Dam Reservoir is the main and rich source of phytoplankton for the outflowing Narew River. Cyanobacteria were dominant in the river phytoplankton at all sampling stations, but their share in phytoplankton biomass gradually decreased with the distance from the dam. Chemical analysis revealed the presence of microcystins (MCs) in water samples collected from June to October. The toxins, mainly demethylated MC analogues, were detected at a long distance down the river, even 100 km from the dam. Maximum concentration of MCs (14.3 μg l^?1) was measured on 13 October, 9.1 km below the dam.     

Catalytic and photocatalytic oxidation of diphenyl sulphide to diphenyl sulfoxide over titanium dioxide doped with vanadium,zinc, and tin

Samples of TiO₂ (P25) doped with zinc, tin, and vanadium, thermally treated at 550 °C for 6 h, were tested as catalysts and photocatalysts for the oxidation of diphenyl sulphide to diphenyl sulfoxide and sulfone, using hydrogen peroxide as an oxidation agent. Thermal treatment of pure TiO₂ and its vanadium-doped forms resulted in a decrease of anatase and an increase of rutile content. The opposite effect was observed for TiO₂ doped with zinc or tin, where thermal treatment resulted in the rutile to anatase phase transition. The role of V, Zn, and Sn admixtures as TiO₂ phase-composition controllers was postulated. The catalytic and photocatalytic activity was found to be influenced more by the rutile and anatase contents of the samples than the presence of admixtures. The rutile-containing samples, TiO₂ and V-TiO₂, presented much better activity in the catalytic oxidation of diphenyl sulphide compared with the catalysts that only contained the anatase phase, Sn-TiO₂ and Zn-TiO₂. The reaction efficiency was significantly improved under UV radiation. In this case, the best photocatalytic activity was found for calcined TiO₂, containing both anatase and rutile components. An increase in rutile content, observed in the vanadium-doped TiO₂, decreased the efficiency of the photocatalytic diphenyl sulphide oxidation. Thus, the presence of both anatase and rutile phases, with their favourable contributions, typical for P25, is necessary for the effective oxidation of Ph₂S to Ph₂SO. Moreover, it was shown that for the second oxidation stage, Ph₂SO to Ph₂SO₂, the presence of the rutile phase is very important.

Phase transitions of rutile and anatase were directed by V, Zn and Sn admixtures. Rutile containing catalysts were more active in Ph₂S oxidation than pure anatase samples. Efficiency of Ph₂S oxidation was significantly improved under UV radiation.     

Cumulative Effects of Particulate Matter Pollution and Meteorological Variables on the Risk of Influenza-Like Illness

The cold season is usually accompanied by an increased incidence of respiratory infections and increased air pollution from combustion sources. As we are facing growing numbers of COVID-19 cases caused by the novel SARS-CoV-2 coronavirus, an understanding of the impact of air pollutants and meteorological variables on the incidence of respiratory infections is crucial. The incidence of influenza-like illness (ILI) can be used as a close proxy for the circulation of influenza viruses. Recently, SARS-CoV-2 has also been detected in patients with ILI. Using distributed lag nonlinear models, we analyzed the association between ILI, meteorological variables and particulate matter concentration in Bialystok, Poland, from 2013–2019. We found an exponential relationship between cumulative PM_2.5 pollution and the incidence of ILI, which remained significant after adjusting for air temperatures and a long-term trend. Pollution had the greatest effect during the same week, but the risk of ILI was increased for the four following weeks. The risk of ILI was also increased by low air temperatures, low absolute humidity, and high wind speed. Altogether, our results show that all measures implemented to decrease PM_2.5 concentrations would be beneficial to reduce the transmission of SARS-CoV-2 and other respiratory infections.     

Shiga toxin binds to activated platelets

Summary. Hemolytic uremic syndrome (HUS) is associated with acute renal failure in children and can be caused by Shiga toxin (Stx)‐producing Escherichia coli. Thrombocytopenia and formation of renal thrombi are characteristic of HUS, suggesting that platelet activation is involved in its pathogenesis. However, whether Shiga toxin directly activates platelets is controversial. The present study evaluates if potential platelet sensitization during isolation by different procedures influences platelet interaction with Shiga toxin. Platelets isolated from sodium citrate anticoagulated blood were exposed during washing to EDTA and higher g forces than platelets prepared from acid‐citrate‐dextrose (ACD) plasma. Platelet binding of Stx was significantly higher in EDTA‐washed preparations relative to ACD‐derived platelets. Binding of Stx was also increased with ACD‐derived platelets when activated with thrombin (1 U mL^?1) and exposure of the Gb3 Stx receptor was detected only on platelets subjected to EDTA, higher g forces or thrombin. EDTA‐exposed platelets lost their normal discoid shape and were larger. P‐selectin (CD62P) exposure was significantly increased in EDTA‐washed preparations relative to ACD‐derived platelets, suggesting platelet activation. Taken together, these results suggest that direct binding of Stx occurs only on ‘activated’ platelets rather than on resting platelets. The ability of Stx to interact with previously activated platelets may be an important element in understanding the pathogenesis of HUS.