Reassessment of the Effect of Transcutaneous Auricular Vagus Nerve Stimulation Using a Novel Burst Paradigm on Cardiac Autonomic Function in Healthy Young Adults.

BACKGROUND: Transcutaneous auricular vagus nerve stimulation (taVNS) may modulate cardiac autonomic function. However, the response rate of the traditional tonic paradigm is low, and the results remain inconsistent. A recent pilot study presented a novel burst paradigm to activate the cardiac parasympathetic system, which might offer a new approach to treat cardiac autonomic function. The present study reassessed the effect of burst taVNS on modulating heart rate variability and explored the difference between burst and traditional tonic paradigms. MATERIALS AND METHODS: Forty-two young adults were recruited for this study. Each participant underwent three types of taVNS with sham (30 sec of stimulation), tonic (25 Hz, 500 µsec), and burst (five pulses at 500 Hz every 200 msec) paradigms, respectively, with simultaneous electrocardiogram recording. One-way analysis of variance, multivariate analysis of variance, and linear regression were used for analysis. Multiple testing was performed using Bonferroni correction. RESULTS: Both burst and tonic paradigms induced a significant decrease in heart rate, which continued until poststimulation, and increased cardiac parasympathetic activity. Moreover, two parasympathetic system indicators showed significant increase only in burst taVNS. The response rates during burst (35.7%) and tonic (38.1%) stimulations were both higher than that during sham stimulation (11.9%). The response to taVNS showed parameter specificity with few nonresponders to the tonic paradigm responding to the burst paradigm. The overall response rate increased from 38.1% in tonic taVNS to 54.8% in taVNS using both burst and tonic paradigms. For both burst and tonic responders, baseline cardiac parasympathetic activity was found to be significantly negatively correlated with changes during stimulation. CONCLUSION: The burst parameter could be used as an alternative strategy for regulating cardiac parasympathetic function by taVNS, which has the potential to be used as a complementary paradigm to traditional tonic taVNS for promoting clinical treatment efficacy.

Baseline Brain Gray Matter Volume as a Predictor of Acupuncture Outcome in Treating Migraine.

Background: The present study aimed to investigate the use of imaging biomarkers to predict the outcome of acupuncture in patients with migraine without aura (MwoA). Methods: Forty-one patients with MwoA received 4 weeks of acupuncture treatment and two brain imaging sessions at the Beijing Traditional Chinese Medicine Hospital affiliated with Capital Medical University. Patients kept a headache diary for 4 weeks before treatment and during acupuncture treatment. Responders were defined as those with at least a 50% reduction in the number of migraine days. The machine learning method was used to distinguish responders from non-responders based on pre-treatment brain gray matter (GM) volume. Longitudinal changes in GM predictive regions were also analyzed. Results: After 4 weeks of acupuncture, 19 patients were classified as responders. Based on 10-fold cross-validation for the selection of GM features, the linear support vector machine produced a classification model with 73% sensitivity, 85% specificity, and 83% accuracy. The area under the receiver operating characteristic curve was 0.7871. This classification model included 10 GM areas that were mainly distributed in the frontal, temporal, parietal, precuneus, and cuneus gyri. The reduction in the number of migraine days was correlated with baseline GM volume in the cuneus, parietal, and frontal gyri in all patients. Moreover, the left cuneus showed a longitudinal increase in GM volume in responders. Conclusion: The results suggest that pre-treatment brain structure could be a novel predictor of the outcome of acupuncture in the treatment of MwoA. Imaging features could be a useful tool for the prediction of acupuncture efficacy, which would enable the development of a personalized medicine strategy.

[Molluscicidal effect of Phytolacca americana linn leaf against Oncomelania hupensis and its acute toxicity].

OBJECTIVE: To study the molluscicidal activity, the influence on glycogen content of Oncomelania hupensis and the acute toxicity to zebra fish of the extract from Phytolacca americana Linn leaf. METHODS: The different polar factions of the extract of Phytolacca americana Linn leaf were separated by using the systemic solvent segregation method, and then the molluscicidal activity of the fractions was detected according to the Laboratory Final Milluscicides Screening Method issued by WHO. The glycogen content of soft tissues of Oncomelania hupensis treated by the ethyl acetate polar fraction was determined by the anthrone method. Finally, the acute toxicity of the ethyl acetate polar fraction to non-targets was studied with zebra fish. RESULTS: The ethyl acetate polar fraction was the best active components against the snails. Its 48 h LC50 and LC90 were 6.0 mg/100 ml and 26.1 mg/ 100 ml, respectively. The glycogen content of soft tissues of the snails decreased by 20% after treated with the fraction. The fish treated by the concentration of LC50 (48 h) of the ethyl acetate polar fraction survived for 12 h. CONCLUSION: The Phytolacca americana Linn leaf possesses an adequate molluscicidal activity and a significant acute toxicity to the zebra fish.