Direct brain recordings reveal prefrontal cortex dynamics of memory development

Prevailing theories link prefrontal cortex (PFC) maturation to the development of declarative memory. However, the precise spatiotemporal correlates of memory formation in the developing brain are not known. We provide rare intracranial evidence that the spatiotemporal propagation of frontal activity supports memory formation in children. Seventeen subjects (6.2 to 19.4 years) studied visual scenes in preparation for a recognition memory test while undergoing direct cortical monitoring. Earlier PFC activity predicted greater accuracy, and subsecond deviations in activity flow between subregions predicted memory formation. Activity flow between inferior and precentral sites was refined during adolescence, partially explaining gains in memory. In contrast, middle frontal activity predicted memory independent of age. These findings show with subsecond temporal precision that the developing PFC links scene perception and memory formation and underscore the role of the PFC in supporting memory development.

Molecular Characterization, Fitness, and Mycotoxin Production of Fusarium asiaticum Strains Resistant to Fludioxonil

Fludioxonil is used in seedborne disease management of various fungal pathogens, including Fusarium asiaticum, the predominant causal agent of Fusarium head blight in China. In this study, we screened resistant strains from a large number of F. asiaticum strains collected from 2012 to 2016 and found that 4 of 1,000 field strains were highly resistant to fludioxonil. The 50% effective concentration values of the resistant strains and induced mutants ranged from 80 to >400 μg/ml. Compared with field-sensitive strains, all field-collected and laboratory-induced resistant strains exhibited fitness defects in traits including mycelial growth, conidial production, pathogenicity, and sensitivity to osmotic conditions. In the presence of fludioxonil, significantly higher glycerol accumulation was found in sensitive strains but not in resistant individuals. The fludioxonil-resistant strains produced lower amounts of glycerol in liquid culture and lower amounts of trichothecene mycotoxins in rice culture and inoculated wheat spikelets than the fludioxonil-sensitive strains. Sequence analyses of the key genes of the two-component histidine kinase signaling pathway showed various amino acid substitutions in the Os1, Os4, and Os5 genes between field-sensitive and resistant strains or mutants. The results of this study suggest a potential risk of fludioxonil resistance development and a possible influence of resistance mutations on fitness parameters and toxin production in F. asiaticum.

Integrative radiomics expression predicts molecular subtypes of primary clear cell renal cell carcinoma

AIM

To identify combined positron-emission tomography (PET)/magnetic resonance imaging (MRI)-based radiomics as a surrogate biomarker of intratumour disease risk for molecular subtype ccA and ccB in patients with primary clear cell renal cell carcinoma (ccRCC).

MATERIALS AND METHODS

PET/MRI data were analysed retrospectively from eight patients. One hundred and sixty-eight radiomics features for each tumour sampling based on the regionally sampled tumours with 23 specimens were extracted. Sparse partial least squares discriminant analysis (SPLS-DA) was applied to feature screening on high-throughput radiomics features and project the selected features to low-dimensional intrinsic latent components as radiomics signatures. In addition, multilevel omics datasets were leveraged to explore the complementing information and elevate the discriminative ability.

RESULTS

The correct classification rate (CCR) for molecular subtype classification by SPLS-DA using only radiomics features was 86.96% with permutation test p=7×10^-4. When multi-omics datasets including mRNA, microvascular density, and clinical parameters from each specimen were combined with radiomics features to refine the model of SPLS-DA, the best CCR was 95.65% with permutation test, p<10^-4; however, even in the case of generating the classification based on transcription features, which is the reference standard, there is roughly 10% classification ambiguity. Thus, this classification level (86.96-95.65%) of the proposed method represents the discriminating level that is consistent with reality.

CONCLUSION

Featured with high accuracy, an integrated multi-omics model of PET/MRI-based radiomics could be the first non-invasive investigation for disease risk stratification and guidance of treatment in patients with primary ccRCC.

Recyclable heat-resisting polymer poly(ether azaindole ketone)-H+via hydrogen bonding crosslinking

A novel recyclable hydrogen bonding crosslinked polymer PEAINKH⁺ was prepared, which possesses outstanding thermal stability.

Clinical and prognostic significance of serum transforming growth factor-beta1 levels in patients with pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) has a poor 5-year survival rate of 5%. Biomarkers for the early detection of pancreatic cancer are urgently needed. Transforming growth factor-beta1 (TGF-β1) is elevated in the tissues and plasma of patients with PDAC. However, no studies systemically report prognostic significance of plasma TGF-β1 levels in PDAC. In the present study, we assessed the prognostic significance of serum TGF-β levels in patients with PDAC. TGF-β levels were determined in serum from 146 PDAC patients, and 58 patients with benign pancreatic conditions. Regression models were used to correlate TGF-β levels to gender, age, stage, class, and metastasis. Survival analyses were performed using multivariate Cox models. Serum levels of TGF-β1 distinguished PDAC from benign pancreatic conditions (P<0.001) and healthy control subjects (P<0.001). Serum levels of TGF-β also distinguished tumor stage (P=0.002) and lymph node metastasis (P=0.001). High serum levels of TGF-β1 were significantly correlated with reduced patient survival. Multivariate analysis revealed that TGF-β1, lymph node metastasis and tumor stage were independent factors for PDAC survival. Our results indicate that serum TGF-β1 may be used as a potential prognostic marker for PDAC.

Transcriptome and proteome analyses reveal complex mechanisms of reproductive diapause in the two-spotted spider mite, Tetranychus urticae

Although a variety of factors underlying diapause have been identified in arthropods and other organisms, the molecular mechanisms regulating diapause are still largely unknown. Here, to better understand this process, we examined diapause-associated genes in the two-spotted spider mite, Tetranychus urticae, by comparing the transcriptomes and proteomes of early diapausing and reproductive adult females. Amongst genes underlying diapause revealed by the transcriptomic and proteomic data sets, we described the noticeable change in Ca²⁺ -associated genes, including 65 Ca²⁺ -binding protein genes and 23 Ca²⁺ transporter genes, indicating that Ca²⁺ signalling has a substantial role in diapause regulation. Other interesting changes in diapause included up-regulation of (1) glutamate receptors that may be involved in synaptic plasticity changes, (2) genes involved in cytoskeletal reorganization including genes encoding each of the components of thick and thin filaments, tubulin and members of integrin signalling and (3) genes involved in anaerobic energy metabolism, which reflects a shift to anaerobic energy metabolism in early diapausing mites.

Shape-dependent cellular behaviors and relaxivity of iron oxide-based T1 MRI contrast agents

Recent research efforts about iron oxide nanoparticles has focused on the development of iron oxide-based T₁ contrast agents for magnetic resonance imaging (MRI), such as ultrasmall iron oxide nanospheres (USNPs <4 nm) and ultrathin nanowires (NW, diameter <4 nm). In this paper, we report the cellular uptake behaviors of these two types of ultrasmall scale nanostructures on HepG2 cells. Both these two nanostructures were functionalized with tannic acid and their physical and chemical properties were carefully analyzed before cellular tests. Both USNPs and NWs exhibited strong paramagnetic signals, a property suitable for T₁ MRI contrast agents. The distinct shapes also caused much difference in their cellular uptake behaviors. Specifically, the uptake of USNPs was five times higher than that of NWs after 72 hours incubation. The shape-dependent cellular uptake can potentially lead to different blood circulation times, and subsequently different applications of these two types of ultrasmall nanostructures.

Interleukin-10 does not modulate clopidogrel platelet response in mice

ESSENTIALS: It is unclear whether interleukin-10 (IL-10) could affect clopidogrel metabolism and response. The bioactivation of and response to clopidogrel were determined between mice with or without IL-10. Maximum clopidogrel active metabolite levels were the major driver of platelet response to clopidogrel. IL-10 did not modulate maximum levels of clopidogrel active metabolite and its antiplatelet effects.

SUMMARY

BACKGROUND

Elevated plasma interleukin-10 (IL-10) levels were observed in patients who responded less to clopidogrel (a prodrug that is required for further metabolic bioactivation in the liver). However, no data are currently available suggesting whether there is such an association.

OBJECTIVE

To systematically explore possible differences in the formation of and response to clopidogrel active metabolite (CAM) in mice with or without IL-10 gene expression.

METHODS

A single oral dose of clopidogrel (10 mg kg(-1)) was given to IL-10 knockout (KO) mice and wild-type (WT) control mice, respectively, and pharmacokinetic parameters of clopidogrel and CAM were calculated. Moreover, adenosine diphosphate-induced whole-blood platelet aggregation was measured in mice receiving 0, 5, 10, or 20 mg kg(-1) of clopidogrel, respectively.

RESULTS

Compared with IL-10 KO mice, WT mice had significantly lower area under the plasma concentration-time curve (AUC) of CAM as a result of a shorter mean elimination half-life but had significantly higher AUC of clopidogrel due to slower systemic clearance and smaller volume of distribution. Although AUC of CAM was significantly lower in WT mice than in KO mice, antiplatelet effects of clopidogrel did not differ significantly between the two mouse groups, as their maximum plasma concentrations (Cmax ) of CAM were not significantly different.

CONCLUSIONS

IL-10 expression level affects AUC rather than Cmax of CAM, but the Cmax of CAM is the major driver of antiplatelet effects of clopidogrel in mice.

Can the study of self-assembly in solution lead to a good model for the nucleation pathway? The case of tolfenamic acid

To further our understanding of the role of solution chemistry in directing nucleation processes new experimental and computational data are presented on the solution and crystallisation chemistry of tolfenamic acid (TA), a benchmark polymorphic compound.

To further our understanding of the role of solution chemistry in directing nucleation processes new experimental and computational data are presented on the solution and crystallisation chemistry of tolfenamic acid (TA), a benchmark polymorphic compound. With these, and previously published data, we were able to establish that TA is rapidly fluctuating between conformers in solution with either solvated monomers or dimers present depending on the solvent. Hence, despite the fact that conformational polymorphs can be obtained from crystallisations in ethanol, we found no links between solution chemistry and crystallisation outcomes. We discuss the implications of these conclusions for the nature of the nucleation pathway via dimers and clusters and raise experimental questions about how best to undertake relevant crystallisation studies.

[Activation of transcription factor NF-κB in a rat model of cardiac fibrosis induced by β-adrenoceptor stimulation]

OBJECTIVE

To establish a model of cardiac fibrosis induced by isoproterenol (ISO), the non-selective β adrenoceptor agonist, injected subcutaneously for 7 days in rats, and to observe changes of transcription factor NF-κB in the model.

METHODS

Male SD rats weighing 280-320 g were injected with ISO (0.25 mg/kg/d) subcutaneously for 7 days to induce cardiac fibrosis. The collagen volume fraction was determined by quantitative morphometry of picrosirius red stained left ventricular sections. Collagen types I/III and IL-6 mRNA expressions were analyzed by real time PCR. The pathological changes of the heart were investigated by Hematoxylin and Eosin staining. NF-κB was localized by immunohistochemistry (IHC) and phosphorylated NF-κB levels were assessed by Western blot analysis.

RESULTS

Compared with the controls, ISO significantly elevated the sirius red stained area and collagen volume fraction (12.01±1.644 vs. 0.95±0.067, P<0.001). Similarly, ISO increased the mRNA expressions of collagen Iand collagen III of the heart compared with the controls (10.51±0.47 vs. 0.98±0.02,P<0.001 for collagen I; 9.58±1.33 vs. 1.02±0.02, P<0.001 for collagen III). The number of nuclei was increased and nuclear accumulation was presented in myocardial tissue induced by ISO. The mRNA expression of IL-6 increased in ISO group (1.64±0.18 vs. 1.04±0.07, P<0.01). ISO induced NF-κB nuclear translocation, accompanied by an increase in phosphorylation of NF-κB (10.83±2.05 vs. 1.05±0.27, P<0.001).

CONCLUSION

We conclude that the model of cardiac fibrosis can be successfully induced by ISO injected subcutaneously for 7 days in rats and the activation of nuclear factor NF-κB increased by β-adrenoceptor stimulation.

Altered intrinsic regional activity and corresponding brain pathways reflect the symptom severity of functional dyspepsia

BACKGROUND

Increasing evidence shows central abnormalities in functional dyspepsia (FD) patients, but whether the symptom severity is directly reflected in altered brain patterns remains unclear. The purpose of this study was to explore how FD affected the resting functional brain patterns for different degrees of symptom severity.

METHODS

Functional magnetic resonance imaging was carried out in 40 FD patients and 20 healthy controls. The resting-state brain changes in regional homogeneity (ReHo) and seed correlation analysis were investigated in patients relative to controls. To what degree the brain changes reflected the severity of the disease was assessed by a pattern classification technique.

KEY RESULTS

Altered ReHo values (p < 0.05, FDR corrected) were discovered in multiple brain areas in FD patients, and only the anterior cingulate cortex (ACC) and thalamus exhibited significant correlation with the severity of dyspepsia symptoms. Compared with controls, the neural signal changes of the thalamus were not found in the less severe FD patient group but in the relatively more severe group, while the ACC showed aberrations in both groups. Seed-based correlation analysis revealed ACC- and thalamus-related functional connectivity differences between FD patients and controls at a voxel-wise level, and the altered thalamic circuits provided the best performance in distinguishing FD patients with different levels of symptom severity.

CONCLUSIONS & INFERENCES

Our results indicated that the functional abnormalities of the ACC and thalamus may occur at different clinical courses in FD. This may help us better understand the progression of FD.

Prognostic value of the International Society on Thrombosis and Haemostasis scoring system for overt disseminated intravascular coagulation in emergency department sepsis

PURPOSE

The International Society on Thrombosis and Haemostasis (ISTH) scoring system is a useful tool to diagnosis overt disseminated intravascular coagulation in clinical practice. The main purposes of this study were to investigate the prognostic value of the ISTH score in emergency department (ED) sepsis and compare the ISTH score with two established scoring systems, the Sequential Organ Failure Assessment (SOFA) score and Acute Physiology and Chronic Health Evaluation II (APACHE II) score, and two biomarkers,procalcitonin (PCT) and C-reactive protein (CRP).

METHODS

Septic patients were consecutively enrolled from the ED of Beijing Chaoyang Hospital, China. The ISTH score, SOFA score and APACHE II score were calculated, and PCT and CRP levels were measured on enrollment. A 30-day follow-up was performed.

RESULTS

A total of 680 septic patients were enrolled in this study. The Cox regression analysis showed that the ISTH score had a greater effect on 30-day mortality prediction, and the receiver operating characteristic curve analysis showed that the accuracy of the ISTH score in prediction of 30-day mortality was better than the SOFA score, the APACHE II score, PCT and CRP. Combination of the ISTH score and CRP can enhance the predictive accuracy of 30-day mortality.

CONCLUSION

The ISTH score is a valuable scoring system in the prognosis evaluation in ED sepsis.