Ganglionated Plexus Ablation Procedures to Treat Vasovagal Syncope

Vasovagal syncope (VVS) refers to a heterogeneous group of conditions whereby the cardiovascular reflexes normally controlling the circulation are interrupted irregularly in response to a trigger, resulting in vasodilation, bradycardia, or both. VVS affects one-third of the population at least once in their lifetime or by the age of 60, reduces the quality of life, and may cause disability affecting certain routines. It poses a considerable economic burden on society, and, despite its prevalence, there is currently no proven pharmacological treatment for preventing VVS. The novel procedure of ganglionated plexus (GP) ablation has emerged rapidly in the past two decades, and has been proven successful in treating syncope. Several parameters influence the success rate of GP ablation, including specific ablation sites, localization and surgical techniques, method of access, and the integration of other interventions. This review aims to provide an overview of the existing literature on the physiological aspects and clinical effectiveness of GP ablation in the treatment of VVS. Specifically, we explore the association between GPs and VVS and examine the impact of GP ablation procedures as reported in human clinical trials. Our objective is to shed light on the therapeutic significance of GP ablation in eliminating VVS and restoring normal sinus rhythm, particularly among young adults affected by this condition.

Evaluation of the treatment options for COVID-19 patients using generalized hesitant fuzzy- multi criteria decision making techniques

The breakout of the pandemic COVID-19 has affected numerous countries and territories worldwide. As COVID-19 specific medicines yet to be invented, at present the treatment is case specific, hence identification and evaluation of different prevalent treatment options based on various criteria and attributes are very important not only from the point of view of present pandemic but also for futuristic pandemic preparedness. The present study focuses on identifying, evaluation and ranking of treatment options using Multi Criteria Decision Making (MCDM). In this regard, the existing literature, doctors and scientist were interviewed to know the current treatment options in vogue and the scale of their importance with respect to the criteria. The criteria taken are side effect, regime cost, treatment duration, plasma stability, plasma turnover, time of suppression, ease of application, drug-drug interaction, compliance, fever, pneumonia, intensive care, organ failure, macrophage activation syndrome, hemophagocytic syndrome, pregnancy, kidney problem, age. This study extended Hesitant Fuzzy Set (HFS) to Generalized Hesitant Fuzzy Sets (GHFS). Generalized Hesitant Pentagonal Fuzzy Number (GHPFN) is developed. The properties of GHPFN are demonstrated. Two types of GHPFN has been described. The GHPFN (2nd type) along with MCDM tool Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) has been applied to rank the treatment options. The result of the study ranked 'Hydroxychloroquine' as the first alternative followed by, 'Plasma Exchange', 'Tocilizumab', 'Remdesivir' and 'Favipravir'. To check the robustness and steadiness of the proposed methodology, comparative analysis and sensitivity analysis has been conducted.

Retrieval and Ranking of Combining Ontology and Content Attributes for Scientific Document

Traditional mathematical search models retrieve scientific documents only by mathematical expressions and their contexts and do not consider the ontological attributes of scientific documents, which result in gaps between the queries and the retrieval results. To solve this problem, a retrieval and ranking model is constructed that synthesizes the information of mathematical expressions with related texts, and the ontology attributes of scientific documents are extracted to further sort the retrieval results. First, the hesitant fuzzy set of mathematical expressions is constructed by using the characteristics of the hesitant fuzzy set to address the multi-attribute problem of mathematical expression matching; then, the similarity of the mathematical expression context sentence is calculated by using the BiLSTM two-way coding feature, and the retrieval result is obtained by synthesizing the similarity between the mathematical expression and the sentence; finally, considering the ontological attributes of scientific documents, the retrieval results are ranked to obtain the final search results. The MAP_10 value of the mathematical expression retrieval results on the Ntcir-Mathir-Wikipedia-Corpus dataset is 0.815, and the average value of the NDCG@10 of the scientific document ranking results is 0.9; these results prove the effectiveness of the scientific document retrieval and ranking method.

The outcome of microvascular decompression for hemifacial spasm: a systematic review and meta-analysis

Microvascular decompression (MVD) is the first choice of surgery for hemifacial spasm (HFS). MVD surgery for vertebral artery (VA)-associated HFS is more difficult than for non-VA-associated HFS. There is controversy about the cure rate and complication of MVD for HFS in previous studies. We searched PubMed, Web of Science, and Embase for relevant publications. Based on the search results, we compared the outcomes of MVD for VA-associated HFS and non-VA-associated HFS. At the same time, we analyzed spasm-free rates and the complications and assessed the relationship between VA-associated HFS and gender, left side, and age. For analysis, six studies that included 2952 patients in the VA-associated group and 604 in the non-VA-associated group were selected. The effective rate of MVD was not significantly different between both groups (OR = 1.16, 95% CI 0.81-1.67, P = 0.42). Compared to non-VA-associated group, the transient complications (OR = 0.64, 95% CI 0.46-0.89, P = 0.008) and permanent complications (OR = 0.28, 95% CI 0.15-0.54, P = 0.0001) occurred more frequently in VA-associated group. The rate of hearing loss was significantly higher in VA-associated HFS than non-VA-associated HFS (OR = 0.35, 95% CI 0.19-0.64, P = 0.0007); the facial paralysis after operation was not significantly different between both groups (OR = 1.25, 95% CI 0.91-1.72, P = 0.17). There were older patients (WMD = 3.67, 95% CI 3.29-4.05, P < 0.00001) and more left-sided HFS (OR = 0.23, 95% CI 0.19 - 0.29, P < 0.0002) in the VA-associated HFS group than non-VA-associated HFS group, while the non-VA-associated HFS group was female-dominated (OR = 1.58, 95% CI 1.32 - 1.89, P < 0.00001). Both groups achieved good results in MVD cure rates. In VA-associated HFS, the complication rate of decompression and the rate of hearing loss after operation were higher than in non-VA-associated HFS, but the facial paralysis after operation was similar in both groups, and most complications were transient and disappeared during follow-up. VA-associated HFS is more prevalent in older adults, less prevalent in women, and more predominantly left-sided. More clinical studies are needed to better compare the efficacy and complication of MVD between both groups.

Priming of central- and peripheral mechanisms with heat and cutaneous capsaicin facilitates secondary hyperalgesia to high frequency electrical stimulation

Heat/capsaicin sensitization and electrical high frequency stimulation (HFS) are well known model of secondary hyperalgesia, a phenomenon related to chronic pain conditions. This study investigated whether priming with heat/capsaicin would facilitate hyperalgesia to HFS in healthy subjects. Heat/capsaicin priming consisted of a 45 °C heat stimulation for 5 min followed by a topical capsaicin patch (4x4 cm) for 30 minutes on the volar forearm of 20 subjects. HFS (100 Hz, 5 times 1s, minimum 1.5 mA) was subsequently delivered through a transcutaneous pin electrode approximately 1.5 cm proximal to the heat/capsaicin application. Two sessions were applied in a crossover design; traditional HFS (HFS) and heat/capsaicin sensitization followed by HFS (HFS+HEAT/CAPS). Heat pain threshold (HPT), mechanical pain sensitivity (MPS) and superficial blood perfusion were assessed at baseline, after capsaicin removal, and up to 40 min after HFS. MPS was assessed with pinprick stimulation (128 mN and 256 mN) in the area adjacent to both HFS and heat/capsaicin, distal but adjacent to heat/capsaicin and in a distal control area. HPT was assessed in the area of heat/capsaicin. Higher sensitivity to 128 mN pinprick stimulation (difference from baseline and control area) was observed in the HFS+HEAT/CAPS session than in the HFS session 20 and 30 minutes after HFS. Furthermore, sensitivity was increased after HFS+HEAT/CAPS compared to after heat/capsaicin in the area adjacent to both paradigms, but not in the area distal to heat/capsaicin. Results indicate that heat/capsaicin causes priming of the central- and peripheral nervous system, which facilitates secondary mechanical hyperalgesia to HFS.

Long-term outcomes and predictive ability of non-invasive scoring systems in patients with non-alcoholic fatty liver disease

BACKGROUND & AIMS

Non-invasive scoring systems (NSS) are used to identify patients with non-alcoholic fatty liver disease (NAFLD) who are at risk of advanced fibrosis, but their reliability in predicting long-term outcomes for hepatic/extrahepatic complications or death and their concordance in cross-sectional and longitudinal risk stratification remain uncertain.

METHODS

The most common NSS (NFS, FIB-4, BARD, APRI) and the Hepamet fibrosis score (HFS) were assessed in 1,173 European patients with NAFLD from tertiary centres. Performance for fibrosis risk stratification and for the prediction of long-term hepatic/extrahepatic events, hepatocarcinoma (HCC) and overall mortality were evaluated in terms of AUC and Harrell's c-index. For longitudinal data, NSS-based Cox proportional hazard models were trained on the whole cohort with repeated 5-fold cross-validation, sampling for testing from the 607 patients with all NSS available.

RESULTS

Cross-sectional analysis revealed HFS as the best performer for the identification of significant (F0-1 vs. F2-4, AUC = 0.758) and advanced (F0-2 vs. F3-4, AUC = 0.805) fibrosis, while NFS and FIB-4 showed the best performance for detecting histological cirrhosis (range AUCs 0.85-0.88). Considering longitudinal data (follow-up between 62 and 110 months), NFS and FIB-4 were the best at predicting liver-related events (c-indices>0.7), NFS for HCC (c-index = 0.9 on average), and FIB-4 and HFS for overall mortality (c-indices >0.8). All NSS showed limited performance (c-indices <0.7) for extrahepatic events.

CONCLUSIONS

Overall, NFS, HFS and FIB-4 outperformed APRI and BARD for both cross-sectional identification of fibrosis and prediction of long-term outcomes, confirming that they are useful tools for the clinical management of patients with NAFLD at increased risk of fibrosis and liver-related complications or death.

LAY SUMMARY

Non-invasive scoring systems are increasingly being used in patients with non-alcoholic fatty liver disease to identify those at risk of advanced fibrosis and hence clinical complications. Herein, we compared various non-invasive scoring systems and identified those that were best at identifying risk, as well as those that were best for the prediction of long-term outcomes, such as liver-related events, liver cancer and death.

Predictive Factors of the Adherence to Real-Time Continuous Glucose Monitoring Sensors: A Prospective Observational Study (PARCS STUDY)

BACKGROUND

Information about factors related to better adherence to continuous glucose monitoring (CGM) sensor adherence is quite limited.

MATERIALS AND METHODS

Forty-six participants with type 1 diabetes using continuous subcutaneous insulin infusion (CSII) without CGM were recruited. The participants' characteristics and diabetes-related quality of life (QOL) were evaluated at baseline and one year after starting to use CGM. Participants wearing the sensor for ≥60% of the time were considered as adherent.

RESULTS

The mean age of the 46 participants was 44.1 ± 15.0 years old and the mean glycohemoglobin (HbA1c) was 7.7 ± 1.0%; 60.9% of the participants were classified as adherent. The duration of using CSII was longer in the adherent group, and the degree of diabetic retinopathy was significantly different. There were no significant differences in age, frequency of self-monitoring of blood glucose, or Hypoglycemia Fear Survey (HFS-B for behavior, HFS-W for worry) score at baseline between the adherent and nonadherent groups. The Problem Areas in Diabetes (PAID) score at baseline was significantly higher and the total CSII-QOL score at baseline was significantly lower in the adherent group. The usage of dual-wave bolus was significantly increased in the adherent group (34.6%-61.5%, P = .016), but not in the nonadherent group (33.3%-33.3%, P > .999). The HbA1c level showed a significant improvement in the adherent group (7.8%-7.3%, P < .001), but not in the nonadherent group (7.5%-7.2%, P = .102).

CONCLUSIONS

Higher adherence to CGM sensors may be associated with a heavier emotional burden of diabetes and a worse QOL in relation to CSII at baseline.

A computational model of dopaminergic modulation of hippocampal Schaffer collateral-CA1 long-term plasticity

Dopamine plays a critical role in modulating the long-term synaptic plasticity of the hippocampal Schaffer collateral-CA1 pyramidal neuron synapses (SC-CA1), a widely accepted cellular model of learning and memory. Limited results from hippocampal slice experiments over the last four decades have shown that the timing of the activation of dopamine D1/D5 receptors relative to a high/low-frequency stimulation (HFS/LFS) in SC-CA1 synapses regulates the modulation of HFS/LFS-induced long-term potentiation/depression (LTP/LTD) in these synapses. However, the existing literature lacks a complete picture of how various concentrations of D1/D5 agonists and the relative timing between the activation of D1/D5 receptors and LTP/LTD induction by HFS/LFS, affect the spatiotemporal modulation of SC-CA1 synaptic dynamics. In this paper, we have developed a computational model, a first of its kind, to make quantitative predictions of the temporal dose-dependent modulation of the HFS/LFS induced LTP/LTD in SC-CA1 synapses by various D1/D5 agonists. Our model combines the biochemical effects with the electrical effects at the electrophysiological level. We have estimated the model parameters from the published electrophysiological data, available from diverse hippocampal CA1 slice experiments, in a Bayesian framework. Our modeling results demonstrate the capability of our model in making quantitative predictions of the available experimental results under diverse HFS/LFS protocols. The predictions from our model show a strong nonlinear dependency of the modulated LTP/LTD by D1/D5 agonists on the relative timing between the activated D1/D5 receptors and the HFS/LFS protocol and the applied concentration of D1/D5 agonists.

Effects of uninterrupted sinusoidal LF-EMF stimulation on LTP induced by different combinations of TBS/HFS at the Schaffer collateral-CA1 of synapses

Long-term potentiation (LTP) is an important aspect of synaptic plasticity and is one of the main mechanisms involved in memory. Low-frequency electromagnetic fields (LF-EMFs) such as transcranial magnetic stimulation are emerging neuromodulation tools for the regulation of LTP. However, whether LF-EMFs have different effects on different types of LTP has not yet been verified. Herein, we studied the regulatory effects of 15 Hz/2 mT sinusoidal magnetic field as pre-magnetic stimulation on several types of LTP, which were induced by theta-burst(TBS) or high-frequency stimulation (HFS) or some combination of them, and applied N-methyl-D-aspartate receptor(NMDAR) antagonists to observe the relationship between the regulation of LTP by LF-EMFs and NMDAR in the Schaffer collateral pathway of rat brain slices in vitro. The results presented in this paper are the performance of TBS and HFS was not exactly the same and the recovery speed of TBS-LTP was faster than HFS-LTP after receiving the regulation of LF-EMFs; moreover, the LTP level was affected by the order of combination and the effect of pre-magnetic stimulation could maintain the entire process of the combined induction experiment, while NMDAR antagonists could not completely offset the influence of LF-EMFs. The memory patterns are diverse, and this study has shown LF-EMFs can regulate LTP such as TBS-LTP and HFS-LTP and can continuously affect multiple LTP induction processes. However, different memory processes may have different performance in the face of LF-EMFs regulation. In terms of the mechanism of LF-EMFs-induced LTP regulation, NMDARs may be involved in the process of LF-EMF regulation of LTP, but are not the only factor.

Converging physiological roles of the anthrax toxin receptors

The anthrax toxin receptors-capillary morphogenesis gene 2 (CMG2) and tumor endothelial marker 8 (TEM8)-were identified almost 20 years ago, although few studies have moved beyond their roles as receptors for the anthrax toxins to address their physiological functions. In the last few years, insight into their endogenous roles has come from two rare diseases: hyaline fibromatosis syndrome, caused by mutations in CMG2, and growth retardation, alopecia, pseudo-anodontia, and optic atrophy (GAPO) syndrome, caused by loss-of-function mutations in TEM8. Although CMG2 and TEM8 are highly homologous at the protein level, the difference in disease symptoms points to variations in the physiological roles of the two anthrax receptors. Here, we focus on the similarities between these receptors in their ability to regulate extracellular matrix homeostasis, angiogenesis, cell migration, and skin elasticity. In this way, we shed light on how mutations in these two related proteins cause such seemingly different diseases and we highlight the existing knowledge gaps that could form the focus of future studies.

Should S-1 be better than capecitabine for patients with advanced gastric cancer in Asia? A systematic review and meta-analysis

Background

S-1 or capecitabine (Cap) containing treatment is an increasingly used strategy in patients with advanced gastric cancer in Asia. It is unclear whether there is sufficient evidence to support which regimen is better.

Methods

A systematic review of retrospective studies and randomized controlled trials (RCTs) comparing S-1 with Cap containing treatment in advanced gastric cancer patients was performed. Embase, PubMed, ClinicalTrials.gov, Cochrane Library, and reference lists were searched from inception until August 2018 for relevant studies. Outcomes of interest included 1-year overall survival (OS), 1-year progression-free survival (PFS), objective response rate (ORR), and adverse events. Meta-analyses of the random events were performed. We also performed sensitivity analysis to examine whether the results of the meta-analyses were robust.

Results

A total of 770 subjects from six RCTs and two retrospective studies in Asia were analyzed. Compared with S-1, Cap containing treatment had better ORR (overall risk ratio =0.85, 95% CI: 0.72, 0.99, I ²=0%, P=0.043) and higher incidence of all-grade hand-foot syndrome (HFS) (overall risk ratio =0.29, 95% CI: 0.20, 0.40, I ²=0%, P<0.001) and neutropenia (overall risk ratio =0.85, 95% CI: 0.73, 0.99, I ²=0%, P=0.039). But there was no statistical difference in 1-year PFS, 1-year OS, incidence of other all-grade or grade 3-4 adverse events between S-1 and Cap containing arms (P>0.05). We found no publication bias in this review.

Conclusion

This systematic review showed that for Asian patients, Cap shows superiority in ORR but not 1-year OS or PFS, and it will increase the risk of all-grade HFS and neutropenia. Until now, S-1 containing treatment might be a better choice for advanced gastric cancer patients. But more high-quality RCTs are needed to confirm these results.

Overall Assay of Neuronal Signal Propagation Pattern With Long-Term Potentiation (LTP) in Hippocampal Slices From the CA1 Area With Fast Voltage-Sensitive Dye Imaging

Activity-dependent changes in the input-output (I-O) relationship of a neural circuit are central in the learning and memory function of the brain. To understand circuit-wide adjustments, optical imaging techniques to probe the membrane potential at every component of neurons, such as dendrites, axons and somas, in the circuit are essential. We have been developing fast voltage-sensitive dye (VSD) imaging methods for quantitative measurements, especially for single-photon wide-field optical imaging. The long-term continuous measurements needed to evaluate circuit-wide modifications require stable and quantitative long-term recordings. Here, we show that VSD imaging (VSDI) can be used to record changes in circuit activity in association with theta-burst stimulation (TBS)-induced long-term potentiation (LTP) of synaptic strength in the CA1 area. Our optics, together with the fast imaging system, enabled us to measure neuronal signals from the entire CA1 area at a maximum frame speed of 0.1 ms/frame every 60 s for over 12 h. We also introduced a method to evaluate circuit activity changes by mapping the variation in recordings from the CA1 area to coordinates defined by the morphology of CA1 pyramidal cells. The results clearly showed two types of spatial heterogeneity in LTP induction. The first heterogeneity is that LTP increased with distance from the stimulation site. The second heterogeneity is that LTP is higher in the stratum pyramidale (SP)-oriens region than in the stratum radiatum (SR). We also showed that the pattern of the heterogeneity changed according to the induction protocol, such as induction by TBS or high-frequency stimulation (HFS). We further demonstrated that part of the heterogeneity depends on the I-O response of the circuit elements. The results show the usefulness of VSDI in probing the function of hippocampal circuits.

Fast and Accurate Diagnosis of Autism (FADA): a novel hierarchical fuzzy system based autism detection tool

The main aim of this research work was to develop and validate a novel graphical user interface based hierarchical fuzzy autism detection tool named as "Fast and Accurate Diagnosis of Autism" for the diagnosis of autism disorder quickly and accurately and in addition, this tool also highlights the highly impaired area in each participant. Two groups of children had been participated in this study which includes autism group (N = 40) and normal group (N = 40). The hierarchical fuzzy expert system had been developed using IF-Then rules based on the experiences of the specialists and both the groups were tested on the designed system. It had been validated that the designed system was easily discriminating between the autistic participants and normal participants with an accuracy of 99%. Moreover, the results of the designed system were compared with Childhood Autism Rating Scale; also the tool was clearly highlighting the most impaired area in each participant. It had also been seen that the designed system has a sensitivity of 98.2% and specificity of 99.2%. It can be said that the designed tool can be used by doctors to diagnose autism along with its severity levels and to highlight the highly impaired area accurately and in no time.

The genetic basis of hyaline fibromatosis syndrome in patients from a consanguineous background: a case series

BACKGROUND

Hyaline fibromatosis syndrome (HFS) is a rare heritable multi-systemic disorder with significant dermatologic manifestations. It is caused by mutations in ANTXR2, which encodes a transmembrane receptor involved in collagen VI regulation in the extracellular matrix. Over 40 mutations in the ANTXR2 gene have been associated with cases of HFS. Variable severity of the disorder in different patients has been proposed to be related to the specific mutations in these patients and their location within the gene.

CASE PRESENTATION

In this report, we describe four cases of HFS from consanguineous backgrounds. Genetic analysis identified a novel homozygous frameshift deletion c.969del (p.Ile323Metfs*14) in one case, the previously reported mutation c.134 T > C (p.Leu45Pro) in another case, and the recurrent homozygous frameshift mutation c.1073dup (p.Ala359Cysfs*13) in two cases. The epidemiology of this latter mutation is of particular interest, as it is a candidate for inhibition of nonsense-mediated mRNA decay. Haplotype analysis was performed to determine the origin of this mutation in this consanguineous cohort, which suggested that it may develop sporadically in different populations.

CONCLUSIONS

This information provides insights on genotype-phenotype correlations, identifies a previously unreported mutation in ANTXR2, and improves the understanding of a recurrent mutation in HFS.

Simulated Mortality-We Can Do More

High-fidelity simulation (HFS) is a relatively new teaching modality, which is gaining widespread acceptance in medical education. To date, dozens of studies have proven the usefulness of HFS in improving student, resident, and attending physician performance, with similar results in the allied health fields. Although many studies have analyzed the utility of simulation, few have investigated why it works. A recent study illustrated that permissive failure, leading to simulated mortality, is one HFS method that can improve long-term performance. Critics maintain, however, that the use of simulated death is troubling and excessive. Given the controversy regarding simulated death, we consider the data about the educational value and the emotional harms associated with them, expecting that evidence could be useful in resolving the question. The goal of this narrative review is to explore the argument against simulated mortality and provide educators with an imperative as to why it can be safely utilized.

Weight loss independent changes in adipose tissue macrophage and T cell populations after sleeve gastrectomy in mice

OBJECTIVE

In addition to adipocytes, adipose tissue contains large numbers of immune cells. A wide range of evidence links the activity of these cells to regulation of adipocyte and systemic metabolic function. Bariatric surgery improves several aspects of metabolic derangements and at least some of these effects occur in a weight-loss independent manner. We sought to investigate the impact of vertical sleeve gastrectomy (VSG) on adipose immune cell frequencies.

METHODS

We analyzed the frequencies of immune cells within distinct adipose tissue depots in obese mice that had VSG or sham surgery with a portion of the latter group pair-fed such that their body mass was matched to the VSG animals.

RESULTS

We demonstrate that VSG induced a shift in the epididymal adipose tissue leukocyte profile including increased frequencies of CD11c^- macrophages, increased frequencies of T cells (CD4⁺, CD8⁺, and CD4^-/CD8^- T cells all increased), but a significantly decreased frequency of adipose tissue dendritic cells (ATDC) that, despite the continued high fat feeding of the VSG group, dropped below control diet levels.

CONCLUSIONS

These results indicate that VSG induces substantial changes in the immune populations residing in the adipose depots independent of weight loss.

The Effects of Dual Abnormal Muscle Response Monitoring on Microvascular Decompression in Patients with Hemifacial Spasm

BACKGROUND

Microvascular decompression (MVD) is the most useful treatment for hemifacial spasm (HFS). During MVD surgery, traditional abnormal muscle response (tAMR) is widely used to monitor success in decompressing the facial nerve. Dual AMR (dAMR) is a new monitoring method used during MVD for HFS. We compared the sensitivities and reliabilities of tAMR and dAMR.

METHODS

We performed a retrospective study of 1301 cases of HFS treated using MVD between January 2014 and March 2016. Among the 1301 cases, 587 patients underwent tAMR monitoring and 714 underwent dAMR monitoring.

RESULTS

Typical abnormal muscle response (AMR) waveforms were observed in 484 patients (82.5%) in the tAMR group and in 688 patients (96.4%) in the dAMR group (P < 0.05). AMR waveforms disappeared in 459 patients in the tAMR group and in 655 patients in the dAMR group during MVD. One day, 7 days, 1 month, and 3 months after MVD surgeries with AMR disappearance, the effective rate of MVD was 95.0%, 94.3%, 94.5%, and 95.0%, respectively, in the tAMR group. The corresponding rates were 97.7%, 96.9%, 97.3%, and 98.0% in the dAMR group (P < 0.05). One day, 7 days, 1 month, and 3 months after MVD surgeries with AMR persistence, the effective rate of MVD was 68.0%, 64.0%, 64.0%, and 64.0%, respectively, in the tAMR group. The corresponding rates were 90.9%, 87.9%, 87.9%, and 90.9% in the dAMR group (P < 0.05).

CONCLUSIONS

AMR monitoring provides valuable neurosurgical guidance during MVD for HFS. dAMR monitoring has better sensitivity and reliability than tAMR monitoring.

Development of sorafenib-related side effects in patients diagnosed with advanced hepatocellular carcinoma treated with sorafenib: a systematic-review and meta-analysis of the impact on survival

​Introduction: Clinical markers to predict the benefit from sorafenib in patients diagnosed with hepatocellular carcinoma (HCC) are lacking. A meta-analysis exploring the impact of development of sorafenib-related side effects on survival was conducted. Areas covered: Eligible studies included all clinical studies reporting on the survival/toxicity relationship in sorafenib-treated HCC patients. Data sources included Pub-Med, the Cochrane Controlled Trials Register, and Google scholar. After exclusion of ineligible studies, 16 studies were included in the analysis. Pooled hazard ratio (HR) for overall survival (OS) for patients developing diarrhoea vs. patients who did not was 0.42 (95% confidence interval (CI): 0.30-0.60; p < 0.00001); pooled HR for patients developing hypertension vs. those who did not was 0.46 (95% CI: 0.30-0.70; p = 0.0003); pooled HR for patients developing hand foot skin reaction vs. those who did not was 0.47 (95% CI: 0.35-0.62; p < 0.00001); pooled HR for OS for all types of skin toxicities was 0.51 (95% CI: 0.36-0.72; p = 0.0002); while pooled HR for OS for a combination of selected side effects (hypertension, HFS and diarrhoea) was 0.38 (95% CI: 0.30-0.48; p < 0.00001). No information was available regarding the impact of thyroid dysfunction or proteinuria. Expert commentary: This analysis of data demonstrated that the occurrence of sorafenib-related side effects (such as diarrhoea, hypertension and skin toxicities) is associated with a better OS in sorafenib-treated HCC patients.

Adult-born dentate granule cells show a critical period of dendritic reorganization and are distinct from developmentally born cells

Adult-born dentate granule cells (abGCs) exhibit a critical developmental phase during function integration. The time window of this phase is debated and whether abGCs become indistinguishable from developmentally born mature granule cells (mGCs) is uncertain. We analyzed complete dendritic reconstructions from abGCs and mGCs using viral labeling. AbGCs from 21-77 days post intrahippocampal injection (dpi) exhibited comparable dendritic arbors, suggesting that structural maturation precedes functional integration. In contrast, significant structural differences were found compared to mGCs: AbGCs had more curved dendrites, more short terminal segments, a different branching pattern, and more proximal terminal branches. Morphological modeling attributed these differences to developmental dendritic pruning and postnatal growth of the dentate gyrus. We further correlated GC morphologies with the responsiveness to unilateral medial perforant path stimulation using the immediate-early gene Arc as a marker of synaptic activation. Only abGCs at 28 and 35 dpi but neither old abGCs nor mGCs responded to stimulation with a remodeling of their dendritic arbor. Summarized, abGCs stay distinct from mGCs and their dendritic arbor can be shaped by afferent activity during a narrow critical time window.

A Phase II Study of XELOX and Cetuximab as First-Line Therapy in Patients With KRAS Wild Type Metastatic Colorectal Cancer (FLEET2 Study)

BACKGROUND

Despite the comparable clinical benefit of XELOX (capecitabine with oxaliplatin) and FOLFOX (5-fluorouracil, leucovorin, and oxaliplatin), the value of XELOX treatment in combination with cetuximab for metastatic colorectal cancer (mCRC) remains largely unknown.

PATIENTS AND METHODS

In this clinical trial we evaluated the efficacy and safety of weekly/biweekly cetuximab administration combined with biweekly XELOX in patients with previously untreated v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) wild type mCRC. The primary end point was response rate (RR) with confirmation, and the secondary end points included progression-free survival (PFS), overall survival (OS), disease control rate (DCR), dose intensity, and the safety of the protocol treatment.

RESULTS

Forty patients who fulfilled the inclusion criteria participated in this study. The median treatment cycle number was 8 and the median dose intensities were 218 mg/m²/wk for cetuximab, 34 mg/m²/wk for oxaliplatin, and 821 mg/m²/d for capecitabine. One patient showed complete response and partial response was observed in 19 patients, giving an overall RR of 50% (95% confidence interval [CI], 33.8%-66.2%). Stable disease was obtained in 13 patients, resulting in a DCR of 82.5% (95% CI, 67.2%-92.7%). The PFS was 6.5 months (95% CI, 3.5-9.6 months), and the OS was 24.3 months (95% CI, 14.9-33.7 months). The safety profile revealed the common Grade 3/4 adverse events to be acneiform eruption (12.5%), peripheral neuropathy (7.5%), and elevated alanine transaminase levels (7.5%). Grade 3/4 thrombocytopenia and neutropenia occurred only in 5.0% and 2.5% of the patients, respectively. Grade 1 hand-foot syndrome (HFS) was not uncommon (20%), whereas Grade 2/3 HFS occurred in only 3 patients (7.5%). No deaths were reported within 30 days of the last dose.

CONCLUSION

Cetuximab with XELOX showed a confirmed overall RR of 50%, which was within the previously reported range of RR. The safety profile showed an acceptable rate and severity of adverse events. In light of the several advantages of XELOX, including convenience and the reported cost-saving aspects, further study of this combination therapy is warranted.

A Comparative Study of the Impact of Theta-Burst and High-Frequency Stimulation on Memory Performance

The transformation of the information stored in the working memory into the system of long-term memory depends on the physiological mechanism, long-term potential (LTP). In a large number of experimental studies, theta-burst stimulation (TBS) and high-frequency stimulation (HFS) are LTP induction protocols. However, they have not been adapted to the model related to memory. In this paper, the improved Camperi–Wang (C–W) model with Ca²⁺ subsystem-induced bi-stability was adopted, and TBS and HFS were simulated to act as the initial stimuli of this working memory model. Evaluating the influence of stimuli properties (cycle, amplitude, duty ration) on memory mechanism of the model, it is found that both TBS and HFS can be adopted to activate working memory model and produce long-term memory. Moreover, the different impacts of two types of stimuli on the formation of long-term memory were analyzed as well. Thus, the importance of this study lies firstly in describing the link and interaction between working memory and long-term memory from the quantitative view, which provides a theoretical basis for the study of neural dynamics mechanism of long-term memory formation in the future.

Relations between acoustic cavitation and skin resistance during intermediate- and high-frequency sonophoresis

Enhanced skin permeability is known to be achieved during sonophoresis due to ultrasound-induced cavitation. However, the mechanistic role of cavitation during sonophoresis has been extensively investigated only for low-frequency (LFS, <100 kHz) applications. Here, mechanisms of permeability-enhancing stable and inertial cavitation were investigated by passively monitoring subharmonic and broadband emissions arising from cavitation isolated within or external to porcine skin in vitro during intermediate- (IFS, 100-700 kHz) and high-frequency sonophoresis (HFS, >1 MHz). The electrical resistance of skin, a surrogate measure of the permeability of skin to a variety of compounds, was measured to quantify the reduction and subsequent recovery of the skin barrier during and after exposure to pulsed (1 second pulse, 20% duty cycle) 0.41 and 2.0 MHz ultrasound over a range of acoustic powers (0-21.7 W) for 30 min. During IFS, significant skin resistance reductions and acoustic emissions from cavitation were measured exclusively when cavitation was isolated outside of the skin. Time-dependent skin resistance reductions measured during IFS correlated significantly with subharmonic and broadband emission levels. During HFS, significant skin resistance reductions were accompanied by significant acoustic emissions from cavitation measured during trials that isolated cavitation activity either outside of skin or within skin. Time-dependent skin resistance reductions measured during HFS correlated significantly greater with subharmonic than with broadband emission levels. The reduction of the skin barrier due to sonophoresis was reversible in all trials; however, effects incurred during IFS recovered more slowly and persisted over a longer period of time than HFS. These results quantitatively demonstrate the significance of cavitation during sonophoresis and suggest that the mechanisms and post-treatment longevity of permeability enhancement due to IFS and HFS treatments are different.

High-frequency stimulation of the hippocampus protects against seizure activity and hippocampal neuronal apoptosis induced by kainic acid administration in macaques

Kainic acid (KA) administration is known to cause seizures and neuronal death in the hippocampus. High-frequency stimulation (HFS) of the hippocampus can be a promising method in the treatment of epilepsy while the mechanism of action is unknown yet. It remains unknown whether HFS is neuroprotective for hippocampal neurons following KA-induced seizures in macaques, although HFS has neuroprotective effects in animal models of Parkinson's disease. We therefore examined the effects of HFS on KA-induced seizures and neuronal survival in macaque's hippocampus. Seizure frequency following KA that led to seizures in macaques was strongly reduced by HFS of the hippocampus. In addition, administration of KA led to marked neuronal apoptosis in the hippocampus, accompanied by increased levels of Bax, activated caspase-3 and decreased levels of Bcl-2. HFS was found to attenuate changes in apoptosis-related proteins and robustly decreased neuronal loss following KA administration. These data indicate that hippocampal HFS can protect hippocampal neurons against KA neurotoxicity, and that HFS neuroprotection is likely to operate with inhibition of apoptosis.

Transcriptomic and epigenetic changes in early liver steatosis associated to obesity: effect of dietary methyl donor supplementation

Non-alcoholic fatty liver disease is a primary hepatic manifestation of obesity and an important adverse metabolic syndrome trait. Animal models of diet-induced obesity promote liver fat accumulation putatively associated with alterations in epigenetic profile. Dietary methyl donor-supplementation may protect against this disturbance during early developmental stages affecting the molecular basis of gene regulation. The aim of this study was to investigate the transcriptomic and epigenetic mechanisms implicated in liver fat accumulation as a result of an obesogenic diet and the putative preventive role of dietary methyl donors. Forty-eight male Wistar rats were assigned into four dietary groups for 8 weeks; control, control methyl-donor-supplemented with a dietary cocktail containing betaine, choline, vitamin B12 and folic acid, high-fat-sucrose and high-fat-sucrose methyl-donor-supplemented. Liver fat accumulation induced by a HFS diet was prevented by methyl donor supplementation in HFS-fed animals. A liver mRNA microarray, subsequently validated by real time-qPCR, showed modifications in some biologically relevant genes involved in obesity development and lipid metabolism (Lepr, Srebf2, Agpat3 and Esr1). Liver global DNA methylation was decreased by methyl donor supplementation in control-fed animals. Methylation levels of specific CpG sites from Srebf2, Agpat3 and Esr1 promoter regions showed changes due to the obesogenic diet and the supplementation with methyl donors. Interestingly, Srebf2 CpG23_24 methylation levels (-167 bp and -156 bp with respect to the transcriptional start site) correlated with HDLc plasma levels, whereas Esr1 CpG14 (-2623 bp) methylation levels were associated with body and liver weights and fat content. Furthermore HFS diet-induced liver fat accumulation was prevented by methyl donor supplementation. In conclusion, both obesogenic diet and methyl donor supplementation modified the mRNA hepatic profile as well as the methylation of specific gene promoters and total DNA.

Aβ-AGE aggravates cognitive deficit in rats via RAGE pathway

β-Amyloid (Aβ) accumulation has been proved to be responsible for the pathogenesis of Alzheimer's disease (AD). However, it is not yet clear what makes Aβ accumulate and become toxic in the AD brains. Our previous studies demonstrated that glycated Aβ (Aβ-AGE) could be formed, and it exacerbated the authentic Aβ-mediated neurotoxicity in vitro, but we did not show the role of Aβ-AGE in vivo and the underlying mechanism. In the current study, we synthesized Aβ-AGE by incubating Aβ with methylglyoxal in vitro, and then stereotactically injected Aβ-AGE into lateral ventricle of Sprague-Dawley (SD) rats. We found that Aβ-AGE aggravated Aβ-induced cognitive impairment, which was characterized by higher speed of deterioration of long-term potentiation (LTP), more decrease of dendritic spines density and more down-regulation of synaptic proteins. We also observed the overexpression of receptor for advanced glycation endproducts receptor for AGEs (RAGE) and the activation of downstream molecular (GSK3, NF-κB, p38) in RAGE-mediated pathways. On the other hand, simultaneous application of RAGE antibody or GSK3 inhibitor LiCl reversed the cognitive decline amplified by Aβ-AGE. Our data revealed that in vivo the Aβ-AGE is more toxic than Aβ, and Aβ-AGE could lead to the aggravation of AD-like pathology though the RAGE pathway, suggesting that Aβ-AGE and RAGE may be new therapeutic targets for AD.

Social isolation stress reduces hippocampal long-term potentiation: effect of animal strain and involvement of glucocorticoid receptors

BACKGROUND

Depressive patients show cognitive impairments that are strongly associated with cortisol levels and hippocampus functioning that interact via unknown mechanisms. In addition, a relation between depression and hippocampal synaptic plasticity was described.

METHODS

In the first experiment, strain-dependent effects of 72-h social isolation on long-term potentiation (LTP) in the CA1 area of the in vitro hippocampus, was determined. Extracellular field excitatory postsynaptic potentials were recorded and a brief high-frequency stimulation (100 Hz, 1s) was applied and recording resumed after the high frequency stimulation (HFS) for 30 min to determine the effect of HFS. In the second experiment we investigated the effect of 72 h of corticosterone treatment and the involvement of glucocorticoid receptors (GRs) in the effect of 72 h of social isolation on LTP in the CA1 area of hippocampus, in vitro.

RESULTS

Genetic background has a major effect on the level of hippocampal LTP impairment in mice following social isolation. Data showed that the potentiation levels in socially housed (SH) A/J mice were significantly higher than the SH C57BL/6J mice (224.88 ± 16.65, 131.56 ± 6.25% of the baseline values, t(9)=2.648, p=0.026). However, both strains showed depressed induction of potentiation when reared in an isolated environment for 72 h, and no significant difference was recorded between the two (112.88 ± 16.65%, and 117.91 ± 3.23% of the baseline values, respectively, t(10)=0.618, p=0.551). Social isolation increased corticosterone levels significantly and chronic corticosterone infusion in SH phenocopied the LTP impairments observed in socially isolated mice. Infusion of the GR antagonist RU38486 rescued the LTP-impairments following social isolation.

CONCLUSIONS

These findings support the notion that increased levels of stress hormone act via the GR on hippocampal functioning and that, in this way, the cognitive deficits in mood disorders may be restored.

Bone quality and strength are greater in growing male rats fed fructose compared with glucose

Optimization of peak bone mass during adolescence is important for osteoporosis prevention. Studies in rodents and humans have demonstrated the harmful effects of sugar intake on bone health. With the high levels of sucrose in the diets of adolescents, it is necessary to understand the influence of glucose and fructose on growing bones. This study compared the effects of dietary glucose and fructose on bone formation, microarchitecture, and strength. Because of the different metabolic effects of glucose and fructose, we hypothesized that their individual effects on bone would be different. Eighteen male Sprague-Dawley rats (age, 60 days) were randomly assigned to high-fructose (n = 9; 40% fructose, 10% glucose) or high-glucose diet (n = 9; 50% glucose) for 12 weeks. Bone measurements included histology and histomorphometry of trabecular bone in the distal femur and a 3-point bending test of the whole tibia. Whole liver mass and postprandial serum glucose, insulin, and triglycerides were used to assess differences in energy metabolism between the diets. There were no differences in food intake, body weight, or visceral adiposity between groups, but fructose consumption led to heavier livers (P = .001) and elevated serum triglycerides (P = .00). The distal femurs of fructose-fed rats had greater bone volume (bone volume/total volume; P = .03), lower bone surface (bone surface/bone volume; P = .02), and thicker trabeculae (trabecular thickness; P = .01). The tibias of the fructose-fed rats also withstood a greater maximum flexure load (P = .032). These results indicate that consumption of the high-fructose diet resulted in stronger bones with enhanced microarchitecture than consumption of the high-glucose diet.

Pre-pubertal castration improves spatial learning during mid-adolescence in rats

Hippocampus functions, including spatial cognition and stress responses, mature during adolescence. In addition, hippocampus neuronal structures are modified by circulating sex steroids, which dramatically increase during adolescence. Therefore, the effects of castration and the circulating levels of the main sex steroid testosterone on spatial learning and memory were examined across postnatal ages to test whether pre-pubertal castration affected rats' spatial ability in the Morris Water maze (MWM). Male rats were either castrated or sham-castrated at 22d (days of age), or left gonadally intact. They were then trained and tested in the MWM beginning at 28d, 35d, 45d or 60d. We found that all of the intact rats learned the spatial task; however, the males at 22d and 28d required more trials to acquire the task than the males at older ages. The males castrated at 22d and tested at 35d had significantly lower escape latency and traveled distance during training than the sham-castrated males trained at the same age. No differences were observed in mean values of escape latency and traveled distance at 45d even though they had comparable levels of testosterone. We conclude that adult-typical performance for male spatial memory emerges during mid-adolescence and that pre-pubertal castration appears to improve spatial learning during this time.

Effects of prolyl-hydroxylase inhibition and chronic intermittent hypoxia on synaptic transmission and plasticity in the rat CA1 and dentate gyrus

Chronic intermittent hypoxia (CIH) is an underlying component of obstructive sleep apnoea and has been shown to have deleterious and damaging effects on central neurons and to impair synaptic plasticity in the CA1 region of the rat hippocampus. CIH has previously been shown to impair synaptic plasticity and working memory. CIH is a potent inducer of hypoxia inducible factor (HIF), a key regulator in a cell's adaptation to hypoxia that plays an important role in the fate of neurons during ischemia. Levels of HIF-1α are regulated by the activity of a group of enzymes called HIF-prolyl 4-hydroxylases (PHDs) and these have become potential pharmacological targets for preconditioning against ischemia. However little is known about the effects of prolyl hydroxylase inhibition and CIH on synaptic transmission and plasticity in sub-regions of the hippocampus. Male Wistar rats were treated for 7-days with either saline, CIH or PHD inhibition (dimethyloxaloylglycine, DMOG; 50mg/kg, i.p.). At the end of treatment all three groups showed no change in synaptic excitability using paired pulse paradigms. However long-term potentiation (LTP) was impaired in the CA1 region of the hippocampus in both CIH and DMOG treated animals. LTP induced in the dentate gyrus was not significantly affected by either CIH or DMOG treatment. We also investigated the effect of 7-day CIH and DMOG treatment on the recovery of synaptic transmission following an acute 30min hypoxic insult. CIH treated animals showed an improved rate of recovery of synaptic transmission following re-oxygenation in both the CA1 and the dentate gyrus. These results suggest that LTP induction in the CA1 region is more sensitive to both CIH and DMOG treatments than the dentate gyrus.

Autonomic denervation added to pulmonary vein isolation for paroxysmal atrial fibrillation: a randomized clinical trial

OBJECTIVES

The aim of this study was to investigate whether the combination of conventional pulmonary vein isolation (PVI) by circumferential antral ablation with ganglionated plexi (GP) modification in a single ablation procedure, yields higher success rates than PVI or GP ablation alone, in patients with paroxysmal atrial fibrillation (PAF).

BACKGROUND

Conventional PVI transects the major left atrial GP, and it is possible that autonomic denervation by inadvertent GP ablation plays a central role in the efficacy of PVI.

METHODS

A total of 242 patients with symptomatic PAF were recruited and randomized as follows: 1) circumferential PVI (n = 78); 2) anatomic ablation of the main left atrial GP (n = 82); or 3) circumferential PVI followed by anatomic ablation of the main left atrial GP (n = 82). The primary endpoint was freedom from atrial fibrillation (AF) or other sustained atrial tachycardia (AT), verified by monthly visits, ambulatory electrocardiographic monitoring, and implantable loop recorders, during a 2-year follow-up period.

RESULTS

Freedom from AF or AT was achieved in 44 (56%), 39 (48%), and 61 (74%) patients in the PVI, GP, and PVI+GP groups, respectively (p = 0.004 by log-rank test). PVI+GP ablation strategy compared with PVI alone yielded a hazard ratio of 0.53 (95% confidence interval: 0.31 to 0.91; p = 0.022) for recurrence of AF or AT. Fluoroscopy duration was 16 ± 3 min, 20 ± 5 min, and 23 ± 5 min for PVI, GP, and PVI+GP groups, respectively (p < 0.001). Post-ablation atrial flutter did not differ between groups: 5.1% in PVI, 4.9% in GP, and 6.1% in PVI+GP. No serious adverse procedure-related events were encountered.

CONCLUSIONS

Addition of GP ablation to PVI confers a significantly higher success rate compared with either PVI or GP alone in patients with PAF.

Patterned high-frequency stimulation induces a form of long-term depression dependent on GABAA and mACh receptors in the hippocampus

Certain patterns of neural activity can induce N-methyl-D-aspartic acid receptor (NMDAR)-dependent synaptic plasticity, one of the important foundations of memory. Here, we report that a patterned high-frequency stimulation (PHS) induces rat hippocampal long-term depression (LTD) in an NMDAR-independent manner that requires coactivation of GABA(A)Rs and muscarinic acetylcholine receptors (mAChRs), and endocytosis of AMPARs. Thus, we disclose that a patterned high-frequency stimulation triggers GABAAR and mAChR-dependent LTD in the hippocampus.

BDNF mechanisms in late LTP formation: A synthesis and breakdown

Unraveling the molecular mechanisms governing long-term synaptic plasticity is a key to understanding how the brain stores information in neural circuits and adapts to a changing environment. Brain-derived neurotrophic factor (BDNF) has emerged as a regulator of stable, late phase long-term potentiation (L-LTP) at excitatory glutamatergic synapses in the adult brain. However, the mechanisms by which BDNF triggers L-LTP are controversial. Here, we distill and discuss the latest advances along three main lines: 1) TrkB receptor-coupled translational control underlying dendritic protein synthesis and L-LTP, 2) Mechanisms for BDNF-induced rescue of L-LTP when protein synthesis is blocked, and 3) BDNF-TrkB regulation of actin cytoskeletal dynamics in dendritic spines. Finally, we explore the inter-relationships between BDNF-regulated mechanisms, how these mechanisms contribute to different forms of L-LTP in the hippocampus and dentate gyrus, and outline outstanding issues for future research. This article is part of the Special Issue entitled 'BDNF Regulation of Synaptic Structure, Function, and Plasticity'.

Neurotoxicity of developmental hypothyroxinemia and hypothyroidism in rats: Impairments of long-term potentiation are mediated by phosphatidylinositol 3-kinase signaling pathway

Neurotoxicity of iodine deficiency-induced hypothyroidism during developmental period results in serious impairments of brain function, such as learning and memory. These impairments are largely irreversible, and the underlying mechanisms remain unclear. In addition to hypothyroidism, iodine deficiency may cause hypothyroxinemia, a relatively subtle form of thyroid hormone deficiency. Neurotoxicity of developmental hypothyroxinemia also potentially impairs learning and memory. However, more direct evidence of the associations between developmental hypothyroxinemia and impairments of learning and memory should be provided, and the underlying mechanisms remain to be elucidated. Thus, in the present study, we investigated the effects of developmental hypothyroxinemia and hypothyroidism on long-term potentiation (LTP), a widely accepted cellular model of learning and memory, in the hippocampal CA1 region. The activation of the phosphatidylinositol 3-kinase (PI3K) signaling pathway - a pathway closely associated with synaptic plasticity and learning and memory - was also investigated. Wistar rats were treated with iodine deficient diet or methimazole (MMZ) to induce developmental hypothyroxinemia or hypothyroidism. The results showed that developmental hypothyroxinemia caused by mild iodine deficiency and developmental hypothyroidism caused by severe iodine deficiency or MMZ significantly reduced the field-excitatory postsynaptic potential (f-EPSP) slope and the population spike (PS) amplitude. Decreased activation of the PI3K signaling pathway was also observed in rats subjected to developmental hypothyroxinemia or hypothyroidism. Our results may support the hypothesis that neurotoxicity of both developmental hypothyroxinemia and hypothyroidism causes damages to learning and memory. Our results also suggest that decreased activation of the PI3K signaling pathway may contribute to impairments of LTP caused by neurotoxicity of both developmental hypothyroxinemia and hypothyroidism.

Opposite long-term synaptic effects of 17β-estradiol and 5α-dihydrotestosterone and localization of their receptors in the medial vestibular nucleus of rats

In brainstem slices of male rats, we examined in single neurons of the medial vestibular nucleus (MVN) the effect of exogenous administration of estrogenic (17β-estradiol, E2) and androgenic (5α-dihydrotestosterone, DHT) steroids on the synaptic response to vestibular afferent stimulation. By whole cell patch clamp recordings we showed that E2 induced synaptic long-term potentiation (LTP) that was cancelled by the subsequent administration of DHT. Conversely, DHT induced synaptic long-term depression (LTD) that was partially reversed by E2. The electrophysiological findings were supported by immunohistochemical analysis showing the presence of estrogen (ER: α and β) and androgen receptors (AR) in the MVN neurons. We found that a large number of neurons were immunoreactive for ERα, ERβ, and AR and most of them co-localized ERβ and AR. We also showed the presence of P450-aromatase (ARO) in the MVN neurons, clearly proving that E2 can be locally synthesized in the MVN. On the whole, these results demonstrate a role of estrogenic and androgenic signals in modulating vestibular synaptic plasticity and suggest that the enhancement or depression of vestibular synaptic response may depend on the local conversion of T into E2 or DHT.

Chronic asthma results in cognitive dysfunction in immature mice

Asthma is the most common chronic childhood illness today. However, little attention is paid for the impacts of chronic asthma-induced hypoxia on cognitive function in children. The present study used immature mice to establish ovalbumin-induced chronic asthma model, and found that chronic asthma impaired learning and memory ability in Morris Water Maze test. Further study revealed that chronic asthma destroyed synaptic structure, impaired long-term potentiation (LTP) maintaining in the CA1 region of mouse hippocampal slices. We found that intermittent hypoxia during chronic asthma resulted in down-regulation of c-fos, Arc and neurogenesis, which was responsible for the impairment of learning and memory in immature mice. Moreover, our results showed that budesonide treatment alone was inadequate for attenuating chronic asthma-induced cognitive impairment. Therefore, our findings indicate that chronic asthma might result in cognitive dysfunction in children, and more attention should be paid for chronic asthma-induced brain damage in the clinical therapy.

Ganglionated plexus ablation vs linear ablation in patients undergoing pulmonary vein isolation for persistent/long-standing persistent atrial fibrillation: a randomized comparison

BACKGROUND

The optimal ablation technique for persistent and long-standing persistent atrial fibrillation (AF) is unclear. Both linear lesion (LL) and ganglionated plexus (GP) ablation have been used in addition to pulmonary vein isolation (PVI), but no direct comparison of the 2 methods exists.

OBJECTIVE

The aim of this study is to assess the comparative safety and efficacy of 2 different ablation strategies-PVI+LL vs PVI+GP ablation -in patients with persistent or long-standing persistent AF.

METHODS

Two hundred sixty-four consecutive patients with persistent/long-standing persistent AF were randomly assigned to 2 different ablation schemes: PVI+LL (n = 132) and PVI+GP (n = 132) ablation. Consistent sinus rhythm (SR) off antiarrhythmic drug was assessed after follow-up of at least 3 years with the use of an implanted monitoring device.

RESULTS

All procedural end points were acutely achieved. At 12 months after a single procedure, 47% of the patients treated with PVI+LL were in SR compared to 54% of the patients treated with PVI+GP (P = .29). At 3 years, 34% of the patients with PVI+LL and 49% of the patients with PVI+GP maintained SR (P = .035). Atrial flutter was more frequent in the PVI+LL group than in PVI+GP group (18% vs 6%; P = .002). After a second procedure in 78 patients of the PVI+LL group and 55 patients of the PVI+GP group, the long-term overall success rate was 52% and 68%, respectively (P = .006).

CONCLUSIONS

PVI+GP ablation confers superior clinical results with less ablation-related left atrial flutter and reduced AF recurrence compared to PVI+LL ablation at 3 years of follow-up.

BDNF-induced local protein synthesis and synaptic plasticity

Brain-derived neurotrophic factor (BDNF) is an important regulator of synaptic transmission and long-term potentiation (LTP) in the hippocampus and in other brain regions, playing a role in the formation of certain forms of memory. The effects of BDNF in LTP are mediated by TrkB (tropomyosin-related kinase B) receptors, which are known to be coupled to the activation of the Ras/ERK, phosphatidylinositol 3-kinase/Akt and phospholipase C-γ (PLC-γ) pathways. The role of BDNF in LTP is best studied in the hippocampus, where the neurotrophin acts at pre- and post-synaptic levels. Recent studies have shown that BDNF regulates the transport of mRNAs along dendrites and their translation at the synapse, by modulating the initiation and elongation phases of protein synthesis, and by acting on specific miRNAs. Furthermore, the effect of BDNF on transcription regulation may further contribute to long-term changes in the synaptic proteome. In this review we discuss the recent progress in understanding the mechanisms contributing to the short- and long-term regulation of the synaptic proteome by BDNF, and the role in synaptic plasticity, which is likely to influence learning and memory formation. This article is part of the Special Issue entitled 'BDNF Regulation of Synaptic Structure, Function, and Plasticity'.

Deep brain stimulation for obsessive-compulsive disorder: subthalamic nucleus target

Because of its reversibility and adaptability, deep brain stimulation (DBS) has recently gained interest in psychiatric disorders, such as obsessive-compulsive disorders (OCD) and depression. In OCD, DBS is now an alternative procedure to lesions of fascicles such as the anterior capsule, which links the orbitofrontal cortex, the cingulum, and the thalamus, and has been applied to new target such as the nucleus accumbens, with promising results. However, a recent interest has been developed toward the subthalamic nucleus (STN), a key structure of the basal ganglia that connects the motor, limbic, and associative systems. It is known from patients with Parkinson disease that STN-DBS can have significant effects on mood and cognition. Those transient effects are usually seen as "side effects" in Parkinson disease, but are clues to the underappreciated role that STN plays in the limbic circuitry, a role whose precise details are as yet unknown and under active investigation. We present the rationale supporting the use of nonmotor STN as a therapeutic target to treat OCD. In particular, we discuss the recent experience and preliminary results of our group after 6 months of nonmotor STN-DBS in patients with severe OCD.

Cortico-striatal spike-timing dependent plasticity after activation of subcortical pathways

Cortico-striatal spike-timing dependent plasticity (STDP) is modulated by dopamine in vitro. The present study investigated STDP in vivo using alternative procedures for modulating dopaminergic inputs. Postsynaptic potentials (PSP) were evoked in intracellularly recorded spiny neurons by electrical stimulation of the contralateral motor cortex. PSPs often consisted of up to three distinct components, likely representing distinct cortico-striatal pathways. After baseline recording, bicuculline (BIC) was ejected into the superior colliculus (SC) to disinhibit visual pathways to the dopamine cells and striatum. Repetitive cortical stimulation (∼60; 0.2 Hz) was then paired with postsynaptic spike discharge induced by an intracellular current pulse, with each pairing followed 250 ms later by a light flash to the contralateral eye (n = 13). Changes in PSPs, measured as the maximal slope normalized to 5-min pre, ranged from potentiation (∼120%) to depression (∼80%). The determining factor was the relative timing between PSP components and spike: PSP components coinciding or closely following the spike tended towards potentiation, whereas PSP components preceding the spike were depressed. Importantly, STDP was only seen in experiments with successful BIC-mediated disinhibition (n = 10). Cortico-striatal high-frequency stimulation (50 pulses at 100 Hz) followed 100 ms later by a light flash did not induce more robust synaptic plasticity (n = 9). However, an elevated post-light spike rate correlated with depression across plasticity protocols (R(2) = 0.55, p = 0.009, n = 11 active neurons). These results confirm that the direction of cortico-striatal plasticity is determined by the timing of pre- and postsynaptic activity and that synaptic modification is dependent on the activation of additional subcortical inputs.