Genetic influences on functional connectivity associated with feedback processing and prediction error: Phase coupling of theta-band oscillations in twins

Publication date: Available online 31 December 2016
Source:International Journal of Psychophysiology
Author(s): Şükrü Barış Demiral, Simon Golosheykin, Andrey P. Anokhin
Detection and evaluation of the mismatch between the intended and actually obtained result of an action (reward prediction error) is an integral component of adaptive self-regulation of behavior. Extensive human and animal research has shown that evaluation of action outcome is supported by a distributed network of brain regions in which the anterior cingulate cortex (ACC) plays a central role, and the integration of distant brain regions into a unified feedback-processing network is enabled by long-range phase synchronization of cortical oscillations in the theta band. Neural correlates of feedback processing are associated with individual differences in normal and abnormal behavior, however, little is known about the role of genetic factors in the cerebral mechanisms of feedback processing. Here we examined genetic influences on functional cortical connectivity related to prediction error in young adult twins (age 18, n=399) using event-related EEG phase coherence analysis in a monetary gambling task. To identify prediction error-specific connectivity pattern, we compared responses to loss and gain feedback. Monetary loss produced a significant increase of theta-band synchronization between the frontal midline region and widespread areas of the scalp, particularly parietal areas, whereas gain resulted in increased synchrony primarily within the posterior regions. Genetic analyses showed significant heritability of frontoparietal theta phase synchronization (24 to 46%), suggesting that individual differences in large-scale network dynamics are under substantial genetic control. We conclude that theta-band synchronization of brain oscillations related to negative feedback reflects genetically transmitted differences in the neural mechanisms of feedback processing. To our knowledge, this is the first evidence for genetic influences on task-related functional brain connectivity assessed using direct real-time measures of neuronal synchronization.



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Determinants of stimulated salivary flow among haematopoietic stem cell transplantation recipients

Abstract

Objectives

The aetiology of hyposalivation in haematopoietic stem cell transplantation (HSCT) recipients is not fully understood. This study examined the effects of treatment-related aetiological factors, particularly medications, on stimulated salivary flow in HSCT recipients.

Subjects and methods

Adult HSCT recipients (N = 118, 66 males, 27 autologous and 91 allogeneic transplants) were examined. Stimulated whole salivary flow rates (SWSFR) were measured before HSCT and at 6 and 12 months post-HSCT. Linear regression models were used to analyse the associations of medications and transplant-related factors with salivary flow rates, which were compared to salivary flow rates of generally healthy controls (N = 247).

Results

The SWSFR of recipients were lower pre-HSCT (mean ± standard deviation, 0.88 ± 0.56 ml/min; P < 0.001), 6 months post-HSCT (0.84 ± 0.61; P < 0.001) and 12 months post-HSCT (1.08 ± 0.67; P = 0.005) than the SWSFR of controls (1.31 ± 0.65). In addition, hyposalivation (<0.7 ml/min) was more frequent among HSCT recipients pre-HSCT (P < 0.001), 6 months post-HSCT (P < 0.001) and 12 months post-HSCT (P = 0.01) than among controls. The SWSFR was observed to improve over time being significantly higher 12 months post-HSCT compared to pre-HSCT (P < 0.001). The observed decrease of salivary flow could not be explained by the examined transplant-related factors and medications.

Conclusions

Decreased stimulated salivary flow rates could not be explained by the examined factors alone; these findings indicate that hyposalivation in HSCT recipients exhibits a multifactorial aetiology.

Clinical relevance

All HSCT recipients should be considered to be at high risk of hyposalivation and consequent oral diseases, and they should be treated accordingly.

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Effectiveness of resin-based materials against erosive and abrasive enamel wear

Abstract

Objective

The objective of this study was to test the effectiveness of resin-based materials against erosive enamel wear under erosive and abrasive challenges by orange juice and tooth brushing.

Methods

Fifty enamel specimens from third molars were assigned to five groups: ICON resin infiltration with no etching (ICON-NE), ICON resin infiltration with 15 % HCl etching (ICON-AE), Seal & Protect sealant (S&P), Tetric EvoFlow (TEF), and control. Erosive lesions were first created on enamel, then treated with resin-based materials. Erosive and abrasive challenges by orange juice and tooth brushing were repeated after treatments. Erosive wear of the treated areas was measured with 3D scanning microscopy, and data were analyzed using ANOVA and paired t tests.

Results

Treatments with ICON, S&P, and TEF created a protective material coating of 4.5 ± 1.9 μm, 44.3 ± 8.1 μm, and 84.6 ± 15.7 μm in thickness on the lesion surfaces, respectively. After 15 cycles of erosive and abrasive challenges, enamel or material losses were 21.9 ± 2.3 μm for control, 24.5 ± 4.0 μm for ICON-NE, 24.6 ± 7.4 μm for ICON-AE, 11.2 ± 4.1 μm for S&P, and 3.9 ± 1.9 μm for TEF, respectively. The protective coatings were completely lost in the ICON infiltration groups but remained intact in both the S&P and TEF groups after erosive and abrasive challenges.

Conclusion

In contrast to a resin sealant and a flowable composite, ICON infiltration resin was not effective in protecting enamel surfaces from erosive and abrasive wear.

Clinical relevance

Sealant and flowable composite resin may create protective coatings on eroded enamel surfaces and prevent further tissue loss.

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Bonding effectiveness and multi-interfacial characterization of two direct buildup resin core systems bonded to post-space dentin

Abstract

Objectives

The aim of the present study was to evaluate the bonding effectiveness of two resin core buildup systems using conventional methods in the field of adhesive dentistry and a new non-destructive method.

Materials and methods

Twenty-four single-rooted human teeth were built up with dual-cure one-step self-etch adhesive and composite systems (SY1: Clearfil DC bond and Clearfil DC core automix, SY2: Clearfil bond SE one and Clearfil DC core automix one). The prepared samples were sectioned into approximately 1 × 1-mm-thick beams and subjected to micro-tensile bond strength (μTBS) testing (n = 24). The fractured beams after μTBS testing were analyzed by SEM and energy-dispersive X-ray (EDX) spectrometry. The three teeth filled with each resin core system were sectioned and embedded in epoxy resin to observe the dentin–bonding interface under TEM (n = 6). Moreover, three of each resin core-filled teeth without any processing were examined using μCT (n = 6).

Results

Two-way ANOVA revealed that the two factors "root region" (p < 0.001, F = 15.22) and "system" (SY1 < SY2; p < 0.001, F = 22.52) had a significant influence. The μTBS gradually decreased from the coronal side to the apical side of the root canal. Morphological evaluation revealed that SY2 was superior in terms of resin curing at the apical side. μCT non-destructive evaluation clearly revealed gap formation in SY1.

Conclusion

SY2, which included a new light-independent catalyst, showed better bonding effectiveness and adhesive interface to dentin compared to that of SY1.

Clinical relevance

The new catalyst, which is activated by contact with adhesive and resin composite, can be used for resin core buildup restorations.

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Short-term changes on C-reactive protein (CRP) levels after non-surgical periodontal treatment in systemically healthy individuals

Abstract

Objectives

The aim of the present study was to evaluate serum C-reactive protein (CRP) levels in chronic periodontitis patients and periodontally healthy individuals and to assess the effect of non-surgical periodontal treatment on the CRP levels.

Materials and methods

Twenty-two patients with chronic periodontitis (test group) and 22 periodontally healthy individuals (control group), both groups without any systemic disorder or potential confounding factors, were included in the study. At baseline, periodontal clinical variables and CRP levels were obtained in both groups. In the test group, oral hygiene instruction and scaling and root planning were carried out; then, after 60 days, periodontal clinical variables and CRP levels were reevaluated.

Results

The baseline CRP level in the test group was significantly higher than the corresponding value in the control group (1.98 ± 1.55 vs. 1.26 ± 1.05 mg/L; p < 0.05). After periodontal treatment in the test group, there were improvements in all periodontal clinical variables (p < 0.05). The CRP level decreased significantly in those patients with higher baseline levels of CRP (>3 mg/L).

Conclusions

Chronic periodontitis seemed to promote elevated levels of CRP. Furthermore, non-surgical periodontal treatment significantly decreased the levels of CRP only in patients with high baseline levels of such pro-inflammatory cytokine.

Clinical relevance

Periodontitis may be a potential factor to change the risk of CVD. Thus, the control of periodontal infection performed by health professionals may improve cardiovascular health.

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The use of conventional transcutaneous electrical nerve stimulation in chronic facial myalgia patients

Abstract

Objectives

The aim of this study was to evaluate the efficacy of conventional TENS in women affected by chronic facial myalgia.

Materials and methods

The study was performed on 49 women affected by chronic facial myalgia randomly allocated in the TENS group (34 women) and the control group (15 women). The subjective level of pain was assessed by the Visual Analogue Scale indicating the mean (VAS MEAN), the maximum (VAS MAX) and the current intensity of pain (VAS NOW). The level of pain at the muscular palpation sites was assessed by the Pericranial Muscle Tenderness Score (PTS) and the Cervical Muscle Tenderness Score (CTS).

The TENS therapy lasted for 10 weeks, and data were collected at baseline, after 5, 10, 15 and 25 weeks. The differences between groups before and after treatment were compared with the Mann-Whitney and the Kolmogorov-Smirnov tests. The intra-group differences were compared with the one-way ANOVA test.

Results

The results showed that the VAS MEAN, VAS MAX, PTS and CTS were significantly reduced in the TENS group compared to the control group after 10 weeks of TENS (p < 0.05). The intra-group analysis revealed a decreasing tendency of VAS MEAN, VAS MAX, VAS NOW, PTS and CTS in the TENS group in a 25-week period (p < 0.05).

Conclusions

The study demonstrated the efficacy of conventional TENS in patients with chronic facial myalgia and the decrease in both subjective and objective pain.

Clinical relevance

Conventional TENS is a safe, non-invasive, easy-to-administer therapy for chronic facial myalgia.

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Comparison of anesthetic efficacy of 2 and 4 % articaine in inferior alveolar nerve block for tooth extraction—a double-blinded randomized clinical trial

Abstract

Objectives

The purpose of this clinical prospective, randomized, double-blind trial was to compare the anesthetic efficacy of 2 % articaine and 4 % articaine in inferior alveolar nerve block anesthesia for extraction of mandibular teeth.

Materials and methods

In 95 patients, 105 lower molar and premolar teeth were extracted after intraoral inferior alveolar nerve block. In 53 cases, 2 % articaine (group I) and, in 52 cases, 4 % articaine (group II) was administered. The primary objective was to analyze the differences of anesthetic effects between the two groups (complete/sufficient vs. insufficient/none). Furthermore, differences in pulpal anesthesia (onset and depth, examined with pulp vitality tester (min)), as well as in length of soft tissue anesthesia (min), were evaluated. Additionally, the need of a second injection, pain while injecting (numeric rating scale (NRS)), pain during treatment (NRS), pain after treatment (NRS), and other possible complications (excessive pain, bleeding events, prolonged deafness) were analyzed.

Results

Anesthesia was sufficient for dental extractions in both groups without significant differences (p = 0.201). The onset of anesthesia did not differ significantly (p = 0.297). A significantly shorter duration of soft tissue anesthesia was seen in group I (2.9 vs. 4 h; p < 0.001). There was no significant difference in the need for a second injection (p = 0.359), in injection pain (p = 0.386), as well as in pain during (p = 0.287) or after treatment (p = 0.121). In both groups, no complications were seen.

Conclusions

The local anesthetic effect of the 4 % articaine solution is not significantly better when compared to 2 % articaine.

Clinical relevance

For mandibular tooth extraction, articaine 2 % may be used as alternative as well.

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Primary wound closure after tooth extraction for prevention of medication-related osteonecrosis of the jaw in patients under denosumab

Abstract

Objectives

Some recent reports have indicated that local infection causes osteonecrosis of the jaw and described that tooth extraction may not be a direct cause of developing medication-related osteonecrosis of the jaw (MRONJ) in patients receiving antiresorptive medications. Tooth extraction and elimination of the source of infection are expected to reduce the risk of developing MRONJ. However, there is no data regarding prevention for developing osteonecrosis of the jaw in patients receiving denosumab. Therefore, the aim of this study was to investigate the outcome of tooth extractions with proper wound closure in patients receiving denosumab.

Patients and methods

Forty teeth in 19 patients treated with denosumab therapy were extracted under preoperative intravenous antibiotics. Patients who had already developed MRONJ in the extraction sites or who had a history of radiation therapy were excluded. During surgery, bone edges were smoothed and all wounds were closed using the double-layered technique.

Results

Thirty-seven extraction sites (92.5 %) in 17 out of 19 patients (89.5 %) were healed. However, three extraction sites in two patients had complications; one patient had exposed bone and developed MRONJ (stage 1) and the other developed a mucosa fistula. Additional surgical procedures were performed and all wounds were completely healed.

Conclusions

Tooth extractions in patients receiving denosumab can be performed in an appropriate manner and result in good outcomes.

Clinical relevance

This study indicated that tooth extraction with proper wound closure to avoid secondary infection may be effective for the prevention of MRONJ even in high-risk patients.

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Electrical stimulation enhances tissue reorganization during orthodontic tooth movement in rats

Abstract

Objective

This study evaluated the effects of a low-intensity electric current on tissue reorganization during experimental orthodontic tooth movement.

Materials and methods

Thirty-two animals were divided into two groups evaluated on days 3 and 7: OTM—orthodontic tooth movement and OTM + MC—orthodontic tooth movement and microcurrent application (10 μA/5 min). The samples were processed for histological, morphometric, and Western blotting analysis.

Results

Analysis of the periodontal ligament (PL) showed a significantly smaller number of granulocytes in the OTM + MC group on day 7.The number of fibroblasts was significantly higher in the OTM + MC group on days 3 and 7. The area of birefringent collagen fibers was more organized in the OTM + MC group on days 3 and 7. The number of blood vessels was significantly higher in the OTM + MC group on day 7. Microcurrent application significantly increased the number of osteoclasts in the compression region of the PL. In the OTM + MC group on day 7 of tooth movement, the expression of TGF-β1 and VEGF was significantly reduced whereas the expression of bFGF was increased in PL.

Conclusions

Electrical stimulation enhances tissue responses, reducing the number of granulocytes and increasing the number of fibroblasts, blood vessels, and osteoclasts and modulates the expression of TGF-β1, VEFG, and bFGF.

Clinical relevance

This technique is used in many areas of medicine, but poorly explored in dentistry and orthodontics. This treatment is cheap and non-invasive and can be applied by own orthodontist, and it can improve the treatment with a faster and safe tooth movement, without pain.

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Reliability of a Fluorescence-aided Identification Technique (FIT) for detecting tooth-colored restorations: an ex vivo comparative study

Abstract

Objective

The aim of the study was to compare the diagnostic predictive values of a Fluorescence-aided Identification Technique (FIT) with those of the conventional diagnostic method regarding the identification of resin composite restorations.

Materials and methods

Twenty examiners, 10 students, and 10 dentists were asked to identify composite restorations in a full-mouth model using both the FIT (405-nm light source) and the conventional method in combination with a common diagnostic light source. Each dental examination was repeated three times to calculate inter-/intra-operator agreement, repeatability, and reproducibility using kappa statistics. Predictive values were calculated using a filling prevalence of 42 % and the sensitivity and specificity of each method. Pearson's test and the 99 % confidence interval (CI) were used for comparison.

Results

The sensitivity (97 %, CI 94–99 %) and specificity (100 %, CI 98–100 %) of the FIT were significantly higher than those of the conventional method (27 %, CI 21–31 %, and 65 %, CI 58–72 %, respectively). Consequently, the positive (100 %) and negative (98 %) predictive values of the FIT were significantly higher than those of the conventional method (35 and 55 %, respectively). As expressed by the kappa statistics, the repeatability (0.96) and reproducibility (0.95) of the FIT were significantly better than those of the conventional method (0.49, CI 0.42–0.56, and 0.34, CI 0.26–0.43, respectively).

Conclusion

Compared to the conventional technique, the FIT was significantly more reliable as shown by higher sensitivity, specificity, repeatability, and reproducibility values.

Clinical relevance

The FIT should be considered as a reliable and practicable alternative in contrast to the conventional method, which was hardly sufficient as a diagnostic procedure.

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Evaluation of genetic factors involved in nocturnal electromyographic activity of masticatory muscles in twins

Abstract

Objectives

The objectives of this study were to assess sleep bruxism events by directly recording electromyographic activity during sleep and to reveal the relative importance of genetic and environmental factors involved in sleep bruxism in twins.

Material and methods

The subjects consisted of 108 twins (mean age 22.2 ± 6.4 years). Electromyographic activity of temporalis muscles during sleep was evaluated using a portable automatic sleep bruxism analyzer (Grindcare 3.0, Medotech A/S), and recordings were carried out for at least three consecutive nights. Quantitative genetic statistics based on structural equation modeling was utilized to estimate variance components.

Results

Monozygotic twin-pair correlation for the number of nocturnal electromyographic activities recorded in this study (r = 0.463, P = 0.009) was higher than dizygotic twin-pair correlation (r = 0.103, P = 0.725). The proportion of total phenotypic variance in the liability of sleep bruxism to attribute to genetic influences, related to the electromyographic activities, was 48 % (95 % CI 17–95 %) and to unique environmental influences was 52 % (95 % CI 28–82 %).

Conclusions

Additive genetic effects may be a contributing factor to the occurrence of nocturnal EMG activity associated with sleep bruxism.

Clinical relevance

A greater understanding of the contribution of genetic factors could have beneficial uses, including enhanced accuracy of sleep bruxism diagnosis, management of sleep bruxism, and enhanced estimation of the prognosis for patients suffering from sleep bruxism. In addition, it could be also important to adequately evaluate the environmental factors in patients with sleep bruxism.

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Advances in the controlled polymerization of conjugated polymers

Publication date: 13 January 2017
Source:Polymer, Volume 108
Author(s): Lize Verheyen, Pieter Leysen, Marie-Paule Van Den Eede, Ward Ceunen, Tine Hardeman, Guy Koeckelberghs
This article features recent advances in the synthesis of conjugated polymers via a controlled polymerization. These polymerizations typically rely on transition metal catalyzed cross coupling reactions. The mechanisms of the polymerization protocols are discussed in detail. An overview of all possible protocols and all homopolymers that have been investigated is given. Next, the synthesis of copolymers - random, gradient and block copolymers - is reviewed. Another advantage of a controlled polymerization is the possibility to introduce specific functional groups, either at the beginning of each polymer chain by the use of an external initiator, or at the end of the polymer chain using an endcapper. Finally, topologies different from simple linear polymer chains are discussed. This feature article is complementary to other recent review articles on this topic.[1,2]

Graphical abstract

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Graphical Contents list & Author index

Publication date: 13 January 2017
Source:Polymer, Volume 108





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Editorial board

Publication date: 13 January 2017
Source:Polymer, Volume 108





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Welcome to the first issue of polymer for 2017!

Publication date: 13 January 2017
Source:Polymer, Volume 108
Author(s): Rumen Duhlev




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A novel presenilin 1 mutation (F388L) identified in a Chinese family with early-onset Alzheimer's disease

Publication date: February 2017
Source:Neurobiology of Aging, Volume 50
Author(s): Yihong Zhan, Honghua Zheng, Chen Wang, Zhouyi Rong, Naian Xiao, Qilin Ma, Yun-wu Zhang
A subset of Alzheimer's disease (AD) occurrence shows autosomal dominant, familial inheritance patterns. Such familial AD (FAD) are caused by mutations in APP, PSEN1, and PSEN2 genes, which encode amyloid-β (Aβ) precursor protein, presenilin 1 (PS1), and presenilin 2 (PS2), respectively. Here, we report a novel PSEN1 mutation (c.1164C > G, p.F388L, mutation nomenclature according to National Center for Biotechnology Information Reference Sequence: NM_000021.3) occurring in a Chinese family with early-onset AD and cosegregating with affected family members. The average age at onset of this family was 43 years. The F388L mutation locates adjacent to the critical catalytic aspartate site (D385) of PS1. Overexpression of the F388L mutant significantly increased Aβ42 secretion and the ratio of Aβ42/Aβ40 when compared with wild type PS1, consisting with the notion that FAD-associated PS1 mutations induce disease pathogenesis by increasing Aβ42/Aβ40 ratio. Our results identify a novel pathogenic PS1 F388L mutation in a Chinese FAD family.



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Contents continued

Publication date: February 2017
Source:Neurobiology of Aging, Volume 50





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Brain tau deposition linked to systemic causes of death in normal elderly

Publication date: February 2017
Source:Neurobiology of Aging, Volume 50
Author(s): Keith A. Josephs, Nirubol Tosakulwong, Stephen D. Weigand, Melissa E. Murray, Jennifer L. Whitwell, Joseph E. Parisi, Dennis W. Dickson, Ronald C. Petersen
The relationship between causes of death and 4 major neurodegenerative brain proteins (beta-amyloid, tau, alpha-synuclein, and the TAR DNA-binding protein of 43 kDa (TDP-43) were assessed in 94 cognitively normal elderly participants that died without a neurodegenerative disease. There was an association between tau and causes of death (p = 0.01). Tau in the brain was associated with a reduced likelihood of dying from systemic cancers (p = 0.046), and with an increased likelihood of dying from pulmonary (p = 0.03) and gastrointestinal (p = 0.049) diseases. There were no associations between beta-amyloid, alpha-synuclein, or TDP-43 and causes of death. Tau deposition in the brain may have a relationship with systemic causes of death, including cancer, in the cognitively normal elderly.



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Lack of RAB39B mutations in early-onset and familial Parkinson's disease in a Taiwanese cohort

Publication date: February 2017
Source:Neurobiology of Aging, Volume 50
Author(s): Hsien-Han Lin, Ruey-Meei Wu, Han-I. Lin, Meng-Ling Chen, Chun-Hwei Tai, Chin-Hsien Lin
Loss of function mutations in RAB39B were recently linked to X-linked recessive early-onset Parkinsonism with variable degrees of intellectual dysfunction. Postmortem examination of the brain biopsy from a patient carrying the gene deletion revealed widespread α-synuclein pathology. However, subsequent analyses reported conflict results to replicate the role of RAB39B mutations in patients with early-onset Parkinsonism. The aim of this study was to address the genetic contribution of RAB39B in early-onset and familial Parkinson's disease (PD) in a Taiwanese population. Among 466 subjects, we sequenced both the exons and exon-intron boundaries of RAB39B from 235 patients with early-onset PD (age of onset <50 years), 119 probands with familial PD, and 112 ethnicity-matched control subjects. We did not find any coding variants or previously reported mutations, suggesting that RAB39B mutations are not a common cause of early-onset or familial PD in our Taiwanese population.



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Novel presenilin 1 mutation (p.F386I) in a Chinese family with early-onset Alzheimer's disease

Publication date: February 2017
Source:Neurobiology of Aging, Volume 50
Author(s): Yat-Fung Shea, Angel On-Kei Chan, Leung-Wing Chu, Shui-Ching Lee, Chun-yin Law, Chung-him See, Kit-ling Yiu, Patrick Ka-Chun Chiu
Autosomal dominant familial Alzheimer's disease accounts for 0.5% of all Alzheimer's disease. A familial Alzheimer's disease Chinese family, with 7 affected family members, underwent PSEN1 screening in 3 affected family members. A heterozygous novel missense mutation in the PSEN1 gene c.1156T>A, altering phenylalanine to isoleucine at codon 386, was identified. Because the change occurred in conserved domains of this gene and cosegregated with affected family members, this change may have a mutagenic and probably pathogenic effect.



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